diff options
Diffstat (limited to '')
| -rw-r--r-- | external/unbound/iterator/iter_delegpt.c | 645 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_delegpt.h | 417 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_donotq.c | 153 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_donotq.h | 101 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_fwd.c | 506 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_fwd.h | 199 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_hints.c | 542 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_hints.h | 161 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_priv.c | 296 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_priv.h | 112 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_resptype.c | 287 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_resptype.h | 127 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_scrub.c | 754 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_scrub.h | 69 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_utils.c | 1024 | ||||
| -rw-r--r-- | external/unbound/iterator/iter_utils.h | 338 | ||||
| -rw-r--r-- | external/unbound/iterator/iterator.c | 2996 | ||||
| -rw-r--r-- | external/unbound/iterator/iterator.h | 372 |
18 files changed, 9099 insertions, 0 deletions
diff --git a/external/unbound/iterator/iter_delegpt.c b/external/unbound/iterator/iter_delegpt.c new file mode 100644 index 000000000..1d84280d2 --- /dev/null +++ b/external/unbound/iterator/iter_delegpt.c @@ -0,0 +1,645 @@ +/* + * iterator/iter_delegpt.c - delegation point with NS and address information. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file implements the Delegation Point. It contains a list of name servers + * and their addresses if known. + */ +#include "config.h" +#include "iterator/iter_delegpt.h" +#include "services/cache/dns.h" +#include "util/regional.h" +#include "util/data/dname.h" +#include "util/data/packed_rrset.h" +#include "util/data/msgreply.h" +#include "util/net_help.h" +#include "ldns/rrdef.h" +#include "ldns/sbuffer.h" + +struct delegpt* +delegpt_create(struct regional* region) +{ + struct delegpt* dp=(struct delegpt*)regional_alloc( + region, sizeof(*dp)); + if(!dp) + return NULL; + memset(dp, 0, sizeof(*dp)); + return dp; +} + +struct delegpt* delegpt_copy(struct delegpt* dp, struct regional* region) +{ + struct delegpt* copy = delegpt_create(region); + struct delegpt_ns* ns; + struct delegpt_addr* a; + if(!copy) + return NULL; + if(!delegpt_set_name(copy, region, dp->name)) + return NULL; + copy->bogus = dp->bogus; + copy->has_parent_side_NS = dp->has_parent_side_NS; + for(ns = dp->nslist; ns; ns = ns->next) { + if(!delegpt_add_ns(copy, region, ns->name, ns->lame)) + return NULL; + copy->nslist->resolved = ns->resolved; + copy->nslist->got4 = ns->got4; + copy->nslist->got6 = ns->got6; + copy->nslist->done_pside4 = ns->done_pside4; + copy->nslist->done_pside6 = ns->done_pside6; + } + for(a = dp->target_list; a; a = a->next_target) { + if(!delegpt_add_addr(copy, region, &a->addr, a->addrlen, + a->bogus, a->lame)) + return NULL; + } + return copy; +} + +int +delegpt_set_name(struct delegpt* dp, struct regional* region, uint8_t* name) +{ + log_assert(!dp->dp_type_mlc); + dp->namelabs = dname_count_size_labels(name, &dp->namelen); + dp->name = regional_alloc_init(region, name, dp->namelen); + return dp->name != 0; +} + +int +delegpt_add_ns(struct delegpt* dp, struct regional* region, uint8_t* name, + uint8_t lame) +{ + struct delegpt_ns* ns; + size_t len; + (void)dname_count_size_labels(name, &len); + log_assert(!dp->dp_type_mlc); + /* slow check for duplicates to avoid counting failures when + * adding the same server as a dependency twice */ + if(delegpt_find_ns(dp, name, len)) + return 1; + ns = (struct delegpt_ns*)regional_alloc(region, + sizeof(struct delegpt_ns)); + if(!ns) + return 0; + ns->next = dp->nslist; + ns->namelen = len; + dp->nslist = ns; + ns->name = regional_alloc_init(region, name, ns->namelen); + ns->resolved = 0; + ns->got4 = 0; + ns->got6 = 0; + ns->lame = lame; + ns->done_pside4 = 0; + ns->done_pside6 = 0; + return ns->name != 0; +} + +struct delegpt_ns* +delegpt_find_ns(struct delegpt* dp, uint8_t* name, size_t namelen) +{ + struct delegpt_ns* p = dp->nslist; + while(p) { + if(namelen == p->namelen && + query_dname_compare(name, p->name) == 0) { + return p; + } + p = p->next; + } + return NULL; +} + +struct delegpt_addr* +delegpt_find_addr(struct delegpt* dp, struct sockaddr_storage* addr, + socklen_t addrlen) +{ + struct delegpt_addr* p = dp->target_list; + while(p) { + if(sockaddr_cmp_addr(addr, addrlen, &p->addr, p->addrlen)==0) { + return p; + } + p = p->next_target; + } + return NULL; +} + +int +delegpt_add_target(struct delegpt* dp, struct regional* region, + uint8_t* name, size_t namelen, struct sockaddr_storage* addr, + socklen_t addrlen, uint8_t bogus, uint8_t lame) +{ + struct delegpt_ns* ns = delegpt_find_ns(dp, name, namelen); + log_assert(!dp->dp_type_mlc); + if(!ns) { + /* ignore it */ + return 1; + } + if(!lame) { + if(addr_is_ip6(addr, addrlen)) + ns->got6 = 1; + else ns->got4 = 1; + if(ns->got4 && ns->got6) + ns->resolved = 1; + } + return delegpt_add_addr(dp, region, addr, addrlen, bogus, lame); +} + +int +delegpt_add_addr(struct delegpt* dp, struct regional* region, + struct sockaddr_storage* addr, socklen_t addrlen, uint8_t bogus, + uint8_t lame) +{ + struct delegpt_addr* a; + log_assert(!dp->dp_type_mlc); + /* check for duplicates */ + if((a = delegpt_find_addr(dp, addr, addrlen))) { + if(bogus) + a->bogus = bogus; + if(!lame) + a->lame = 0; + return 1; + } + + a = (struct delegpt_addr*)regional_alloc(region, + sizeof(struct delegpt_addr)); + if(!a) + return 0; + a->next_target = dp->target_list; + dp->target_list = a; + a->next_result = 0; + a->next_usable = dp->usable_list; + dp->usable_list = a; + memcpy(&a->addr, addr, addrlen); + a->addrlen = addrlen; + a->attempts = 0; + a->bogus = bogus; + a->lame = lame; + a->dnsseclame = 0; + return 1; +} + +void +delegpt_count_ns(struct delegpt* dp, size_t* numns, size_t* missing) +{ + struct delegpt_ns* ns; + *numns = 0; + *missing = 0; + for(ns = dp->nslist; ns; ns = ns->next) { + (*numns)++; + if(!ns->resolved) + (*missing)++; + } +} + +void +delegpt_count_addr(struct delegpt* dp, size_t* numaddr, size_t* numres, + size_t* numavail) +{ + struct delegpt_addr* a; + *numaddr = 0; + *numres = 0; + *numavail = 0; + for(a = dp->target_list; a; a = a->next_target) { + (*numaddr)++; + } + for(a = dp->result_list; a; a = a->next_result) { + (*numres)++; + } + for(a = dp->usable_list; a; a = a->next_usable) { + (*numavail)++; + } +} + +void delegpt_log(enum verbosity_value v, struct delegpt* dp) +{ + char buf[LDNS_MAX_DOMAINLEN+1]; + struct delegpt_ns* ns; + struct delegpt_addr* a; + size_t missing=0, numns=0, numaddr=0, numres=0, numavail=0; + if(verbosity < v) + return; + dname_str(dp->name, buf); + if(dp->nslist == NULL && dp->target_list == NULL) { + log_info("DelegationPoint<%s>: empty", buf); + return; + } + delegpt_count_ns(dp, &numns, &missing); + delegpt_count_addr(dp, &numaddr, &numres, &numavail); + log_info("DelegationPoint<%s>: %u names (%u missing), " + "%u addrs (%u result, %u avail)%s", + buf, (unsigned)numns, (unsigned)missing, + (unsigned)numaddr, (unsigned)numres, (unsigned)numavail, + (dp->has_parent_side_NS?" parentNS":" cacheNS")); + if(verbosity >= VERB_ALGO) { + for(ns = dp->nslist; ns; ns = ns->next) { + dname_str(ns->name, buf); + log_info(" %s %s%s%s%s%s%s%s", buf, + (ns->resolved?"*":""), + (ns->got4?" A":""), (ns->got6?" AAAA":""), + (dp->bogus?" BOGUS":""), (ns->lame?" PARENTSIDE":""), + (ns->done_pside4?" PSIDE_A":""), + (ns->done_pside6?" PSIDE_AAAA":"")); + } + for(a = dp->target_list; a; a = a->next_target) { + const char* str = " "; + if(a->bogus && a->lame) str = " BOGUS ADDR_LAME "; + else if(a->bogus) str = " BOGUS "; + else if(a->lame) str = " ADDR_LAME "; + log_addr(VERB_ALGO, str, &a->addr, a->addrlen); + } + } +} + +void +delegpt_add_unused_targets(struct delegpt* dp) +{ + struct delegpt_addr* usa = dp->usable_list; + dp->usable_list = NULL; + while(usa) { + usa->next_result = dp->result_list; + dp->result_list = usa; + usa = usa->next_usable; + } +} + +size_t +delegpt_count_targets(struct delegpt* dp) +{ + struct delegpt_addr* a; + size_t n = 0; + for(a = dp->target_list; a; a = a->next_target) + n++; + return n; +} + +size_t +delegpt_count_missing_targets(struct delegpt* dp) +{ + struct delegpt_ns* ns; + size_t n = 0; + for(ns = dp->nslist; ns; ns = ns->next) + if(!ns->resolved) + n++; + return n; +} + +/** find NS rrset in given list */ +static struct ub_packed_rrset_key* +find_NS(struct reply_info* rep, size_t from, size_t to) +{ + size_t i; + for(i=from; i<to; i++) { + if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS) + return rep->rrsets[i]; + } + return NULL; +} + +struct delegpt* +delegpt_from_message(struct dns_msg* msg, struct regional* region) +{ + struct ub_packed_rrset_key* ns_rrset = NULL; + struct delegpt* dp; + size_t i; + /* look for NS records in the authority section... */ + ns_rrset = find_NS(msg->rep, msg->rep->an_numrrsets, + msg->rep->an_numrrsets+msg->rep->ns_numrrsets); + + /* In some cases (even legitimate, perfectly legal cases), the + * NS set for the "referral" might be in the answer section. */ + if(!ns_rrset) + ns_rrset = find_NS(msg->rep, 0, msg->rep->an_numrrsets); + + /* If there was no NS rrset in the authority section, then this + * wasn't a referral message. (It might not actually be a + * referral message anyway) */ + if(!ns_rrset) + return NULL; + + /* If we found any, then Yay! we have a delegation point. */ + dp = delegpt_create(region); + if(!dp) + return NULL; + dp->has_parent_side_NS = 1; /* created from message */ + if(!delegpt_set_name(dp, region, ns_rrset->rk.dname)) + return NULL; + if(!delegpt_rrset_add_ns(dp, region, ns_rrset, 0)) + return NULL; + + /* add glue, A and AAAA in answer and additional section */ + for(i=0; i<msg->rep->rrset_count; i++) { + struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; + /* skip auth section. FIXME really needed?*/ + if(msg->rep->an_numrrsets <= i && + i < (msg->rep->an_numrrsets+msg->rep->ns_numrrsets)) + continue; + + if(ntohs(s->rk.type) == LDNS_RR_TYPE_A) { + if(!delegpt_add_rrset_A(dp, region, s, 0)) + return NULL; + } else if(ntohs(s->rk.type) == LDNS_RR_TYPE_AAAA) { + if(!delegpt_add_rrset_AAAA(dp, region, s, 0)) + return NULL; + } + } + return dp; +} + +int +delegpt_rrset_add_ns(struct delegpt* dp, struct regional* region, + struct ub_packed_rrset_key* ns_rrset, uint8_t lame) +{ + struct packed_rrset_data* nsdata = (struct packed_rrset_data*) + ns_rrset->entry.data; + size_t i; + log_assert(!dp->dp_type_mlc); + if(nsdata->security == sec_status_bogus) + dp->bogus = 1; + for(i=0; i<nsdata->count; i++) { + if(nsdata->rr_len[i] < 2+1) continue; /* len + root label */ + if(dname_valid(nsdata->rr_data[i]+2, nsdata->rr_len[i]-2) != + (size_t)sldns_read_uint16(nsdata->rr_data[i])) + continue; /* bad format */ + /* add rdata of NS (= wirefmt dname), skip rdatalen bytes */ + if(!delegpt_add_ns(dp, region, nsdata->rr_data[i]+2, lame)) + return 0; + } + return 1; +} + +int +delegpt_add_rrset_A(struct delegpt* dp, struct regional* region, + struct ub_packed_rrset_key* ak, uint8_t lame) +{ + struct packed_rrset_data* d=(struct packed_rrset_data*)ak->entry.data; + size_t i; + struct sockaddr_in sa; + socklen_t len = (socklen_t)sizeof(sa); + log_assert(!dp->dp_type_mlc); + memset(&sa, 0, len); + sa.sin_family = AF_INET; + sa.sin_port = (in_port_t)htons(UNBOUND_DNS_PORT); + for(i=0; i<d->count; i++) { + if(d->rr_len[i] != 2 + INET_SIZE) + continue; + memmove(&sa.sin_addr, d->rr_data[i]+2, INET_SIZE); + if(!delegpt_add_target(dp, region, ak->rk.dname, + ak->rk.dname_len, (struct sockaddr_storage*)&sa, + len, (d->security==sec_status_bogus), lame)) + return 0; + } + return 1; +} + +int +delegpt_add_rrset_AAAA(struct delegpt* dp, struct regional* region, + struct ub_packed_rrset_key* ak, uint8_t lame) +{ + struct packed_rrset_data* d=(struct packed_rrset_data*)ak->entry.data; + size_t i; + struct sockaddr_in6 sa; + socklen_t len = (socklen_t)sizeof(sa); + log_assert(!dp->dp_type_mlc); + memset(&sa, 0, len); + sa.sin6_family = AF_INET6; + sa.sin6_port = (in_port_t)htons(UNBOUND_DNS_PORT); + for(i=0; i<d->count; i++) { + if(d->rr_len[i] != 2 + INET6_SIZE) /* rdatalen + len of IP6 */ + continue; + memmove(&sa.sin6_addr, d->rr_data[i]+2, INET6_SIZE); + if(!delegpt_add_target(dp, region, ak->rk.dname, + ak->rk.dname_len, (struct sockaddr_storage*)&sa, + len, (d->security==sec_status_bogus), lame)) + return 0; + } + return 1; +} + +int +delegpt_add_rrset(struct delegpt* dp, struct regional* region, + struct ub_packed_rrset_key* rrset, uint8_t lame) +{ + if(!rrset) + return 1; + if(ntohs(rrset->rk.type) == LDNS_RR_TYPE_NS) + return delegpt_rrset_add_ns(dp, region, rrset, lame); + else if(ntohs(rrset->rk.type) == LDNS_RR_TYPE_A) + return delegpt_add_rrset_A(dp, region, rrset, lame); + else if(ntohs(rrset->rk.type) == LDNS_RR_TYPE_AAAA) + return delegpt_add_rrset_AAAA(dp, region, rrset, lame); + log_warn("Unknown rrset type added to delegpt"); + return 1; +} + +void delegpt_add_neg_msg(struct delegpt* dp, struct msgreply_entry* msg) +{ + struct reply_info* rep = (struct reply_info*)msg->entry.data; + if(!rep) return; + + /* if error or no answers */ + if(FLAGS_GET_RCODE(rep->flags) != 0 || rep->an_numrrsets == 0) { + struct delegpt_ns* ns = delegpt_find_ns(dp, msg->key.qname, + msg->key.qname_len); + if(ns) { + if(msg->key.qtype == LDNS_RR_TYPE_A) + ns->got4 = 1; + else if(msg->key.qtype == LDNS_RR_TYPE_AAAA) + ns->got6 = 1; + if(ns->got4 && ns->got6) + ns->resolved = 1; + } + } +} + +void delegpt_no_ipv6(struct delegpt* dp) +{ + struct delegpt_ns* ns; + for(ns = dp->nslist; ns; ns = ns->next) { + /* no ipv6, so only ipv4 is enough to resolve a nameserver */ + if(ns->got4) + ns->resolved = 1; + } +} + +void delegpt_no_ipv4(struct delegpt* dp) +{ + struct delegpt_ns* ns; + for(ns = dp->nslist; ns; ns = ns->next) { + /* no ipv4, so only ipv6 is enough to resolve a nameserver */ + if(ns->got6) + ns->resolved = 1; + } +} + +struct delegpt* delegpt_create_mlc(uint8_t* name) +{ + struct delegpt* dp=(struct delegpt*)calloc(1, sizeof(*dp)); + if(!dp) + return NULL; + dp->dp_type_mlc = 1; + if(name) { + dp->namelabs = dname_count_size_labels(name, &dp->namelen); + dp->name = memdup(name, dp->namelen); + if(!dp->name) { + free(dp); + return NULL; + } + } + return dp; +} + +void delegpt_free_mlc(struct delegpt* dp) +{ + struct delegpt_ns* n, *nn; + struct delegpt_addr* a, *na; + if(!dp) return; + log_assert(dp->dp_type_mlc); + n = dp->nslist; + while(n) { + nn = n->next; + free(n->name); + free(n); + n = nn; + } + a = dp->target_list; + while(a) { + na = a->next_target; + free(a); + a = na; + } + free(dp->name); + free(dp); +} + +int delegpt_set_name_mlc(struct delegpt* dp, uint8_t* name) +{ + log_assert(dp->dp_type_mlc); + dp->namelabs = dname_count_size_labels(name, &dp->namelen); + dp->name = memdup(name, dp->namelen); + return (dp->name != NULL); +} + +int delegpt_add_ns_mlc(struct delegpt* dp, uint8_t* name, uint8_t lame) +{ + struct delegpt_ns* ns; + size_t len; + (void)dname_count_size_labels(name, &len); + log_assert(dp->dp_type_mlc); + /* slow check for duplicates to avoid counting failures when + * adding the same server as a dependency twice */ + if(delegpt_find_ns(dp, name, len)) + return 1; + ns = (struct delegpt_ns*)malloc(sizeof(struct delegpt_ns)); + if(!ns) + return 0; + ns->namelen = len; + ns->name = memdup(name, ns->namelen); + if(!ns->name) { + free(ns); + return 0; + } + ns->next = dp->nslist; + dp->nslist = ns; + ns->resolved = 0; + ns->got4 = 0; + ns->got6 = 0; + ns->lame = (uint8_t)lame; + ns->done_pside4 = 0; + ns->done_pside6 = 0; + return 1; +} + +int delegpt_add_addr_mlc(struct delegpt* dp, struct sockaddr_storage* addr, + socklen_t addrlen, uint8_t bogus, uint8_t lame) +{ + struct delegpt_addr* a; + log_assert(dp->dp_type_mlc); + /* check for duplicates */ + if((a = delegpt_find_addr(dp, addr, addrlen))) { + if(bogus) + a->bogus = bogus; + if(!lame) + a->lame = 0; + return 1; + } + + a = (struct delegpt_addr*)malloc(sizeof(struct delegpt_addr)); + if(!a) + return 0; + a->next_target = dp->target_list; + dp->target_list = a; + a->next_result = 0; + a->next_usable = dp->usable_list; + dp->usable_list = a; + memcpy(&a->addr, addr, addrlen); + a->addrlen = addrlen; + a->attempts = 0; + a->bogus = bogus; + a->lame = lame; + a->dnsseclame = 0; + return 1; +} + +int delegpt_add_target_mlc(struct delegpt* dp, uint8_t* name, size_t namelen, + struct sockaddr_storage* addr, socklen_t addrlen, uint8_t bogus, + uint8_t lame) +{ + struct delegpt_ns* ns = delegpt_find_ns(dp, name, namelen); + log_assert(dp->dp_type_mlc); + if(!ns) { + /* ignore it */ + return 1; + } + if(!lame) { + if(addr_is_ip6(addr, addrlen)) + ns->got6 = 1; + else ns->got4 = 1; + if(ns->got4 && ns->got6) + ns->resolved = 1; + } + return delegpt_add_addr_mlc(dp, addr, addrlen, bogus, lame); +} + +size_t delegpt_get_mem(struct delegpt* dp) +{ + struct delegpt_ns* ns; + size_t s; + if(!dp) return 0; + s = sizeof(*dp) + dp->namelen + + delegpt_count_targets(dp)*sizeof(struct delegpt_addr); + for(ns=dp->nslist; ns; ns=ns->next) + s += sizeof(*ns)+ns->namelen; + return s; +} diff --git a/external/unbound/iterator/iter_delegpt.h b/external/unbound/iterator/iter_delegpt.h new file mode 100644 index 000000000..eb771359c --- /dev/null +++ b/external/unbound/iterator/iter_delegpt.h @@ -0,0 +1,417 @@ +/* + * iterator/iter_delegpt.h - delegation point with NS and address information. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file implements the Delegation Point. It contains a list of name servers + * and their addresses if known. + */ + +#ifndef ITERATOR_ITER_DELEGPT_H +#define ITERATOR_ITER_DELEGPT_H +#include "util/log.h" +struct regional; +struct delegpt_ns; +struct delegpt_addr; +struct dns_msg; +struct ub_packed_rrset_key; +struct msgreply_entry; + +/** + * Delegation Point. + * For a domain name, the NS rrset, and the A and AAAA records for those. + */ +struct delegpt { + /** the domain name of the delegation point. */ + uint8_t* name; + /** length of the delegation point name */ + size_t namelen; + /** number of labels in delegation point */ + int namelabs; + + /** the nameservers, names from the NS RRset rdata. */ + struct delegpt_ns* nslist; + /** the target addresses for delegation */ + struct delegpt_addr* target_list; + /** the list of usable targets; subset of target_list + * the items in this list are not part of the result list. */ + struct delegpt_addr* usable_list; + /** the list of returned targets; subset of target_list */ + struct delegpt_addr* result_list; + + /** if true, the NS RRset was bogus. All info is bad. */ + int bogus; + /** if true, the parent-side NS record has been applied: + * its names have been added and their addresses can follow later. + * Also true if the delegationpoint was created from a delegation + * message and thus contains the parent-side-info already. */ + uint8_t has_parent_side_NS; + /** for assertions on type of delegpt */ + uint8_t dp_type_mlc; +}; + +/** + * Nameservers for a delegation point. + */ +struct delegpt_ns { + /** next in list */ + struct delegpt_ns* next; + /** name of nameserver */ + uint8_t* name; + /** length of name */ + size_t namelen; + /** + * If the name has been resolved. false if not queried for yet. + * true if the A, AAAA queries have been generated. + * marked true if those queries fail. + * and marked true if got4 and got6 are both true. + */ + int resolved; + /** if the ipv4 address is in the delegpt */ + uint8_t got4; + /** if the ipv6 address is in the delegpt */ + uint8_t got6; + /** + * If the name is parent-side only and thus dispreferred. + * Its addresses become dispreferred as well + */ + uint8_t lame; + /** if the parent-side ipv4 address has been looked up (last resort). + * Also enabled if a parent-side cache entry exists, or a parent-side + * negative-cache entry exists. */ + uint8_t done_pside4; + /** if the parent-side ipv6 address has been looked up (last resort). + * Also enabled if a parent-side cache entry exists, or a parent-side + * negative-cache entry exists. */ + uint8_t done_pside6; +}; + +/** + * Address of target nameserver in delegation point. + */ +struct delegpt_addr { + /** next delegation point in results */ + struct delegpt_addr* next_result; + /** next delegation point in usable list */ + struct delegpt_addr* next_usable; + /** next delegation point in all targets list */ + struct delegpt_addr* next_target; + + /** delegation point address */ + struct sockaddr_storage addr; + /** length of addr */ + socklen_t addrlen; + /** number of attempts for this addr */ + int attempts; + /** rtt stored here in the selection algorithm */ + int sel_rtt; + /** if true, the A or AAAA RR was bogus, so this address is bad. + * Also check the dp->bogus to see if everything is bogus. */ + uint8_t bogus; + /** if true, this address is dispreferred: it is a lame IP address */ + uint8_t lame; + /** if the address is dnsseclame, but this cannot be cached, this + * option is useful to mark the address dnsseclame. + * This value is not copied in addr-copy and dp-copy. */ + uint8_t dnsseclame; +}; + +/** + * Create new delegation point. + * @param regional: where to allocate it. + * @return new delegation point or NULL on error. + */ +struct delegpt* delegpt_create(struct regional* regional); + +/** + * Create a copy of a delegation point. + * @param dp: delegation point to copy. + * @param regional: where to allocate it. + * @return new delegation point or NULL on error. + */ +struct delegpt* delegpt_copy(struct delegpt* dp, struct regional* regional); + +/** + * Set name of delegation point. + * @param dp: delegation point. + * @param regional: where to allocate the name copy. + * @param name: name to use. + * @return false on error. + */ +int delegpt_set_name(struct delegpt* dp, struct regional* regional, + uint8_t* name); + +/** + * Add a name to the delegation point. + * @param dp: delegation point. + * @param regional: where to allocate the info. + * @param name: domain name in wire format. + * @param lame: name is lame, disprefer it. + * @return false on error. + */ +int delegpt_add_ns(struct delegpt* dp, struct regional* regional, + uint8_t* name, uint8_t lame); + +/** + * Add NS rrset; calls add_ns repeatedly. + * @param dp: delegation point. + * @param regional: where to allocate the info. + * @param ns_rrset: NS rrset. + * @param lame: rrset is lame, disprefer it. + * @return 0 on alloc error. + */ +int delegpt_rrset_add_ns(struct delegpt* dp, struct regional* regional, + struct ub_packed_rrset_key* ns_rrset, uint8_t lame); + +/** + * Add target address to the delegation point. + * @param dp: delegation point. + * @param regional: where to allocate the info. + * @param name: name for which target was found (must be in nslist). + * This name is marked resolved. + * @param namelen: length of name. + * @param addr: the address. + * @param addrlen: the length of addr. + * @param bogus: security status for the address, pass true if bogus. + * @param lame: address is lame. + * @return false on error. + */ +int delegpt_add_target(struct delegpt* dp, struct regional* regional, + uint8_t* name, size_t namelen, struct sockaddr_storage* addr, + socklen_t addrlen, uint8_t bogus, uint8_t lame); + +/** + * Add A RRset to delegpt. + * @param dp: delegation point. + * @param regional: where to allocate the info. + * @param rrset: RRset A to add. + * @param lame: rrset is lame, disprefer it. + * @return 0 on alloc error. + */ +int delegpt_add_rrset_A(struct delegpt* dp, struct regional* regional, + struct ub_packed_rrset_key* rrset, uint8_t lame); + +/** + * Add AAAA RRset to delegpt. + * @param dp: delegation point. + * @param regional: where to allocate the info. + * @param rrset: RRset AAAA to add. + * @param lame: rrset is lame, disprefer it. + * @return 0 on alloc error. + */ +int delegpt_add_rrset_AAAA(struct delegpt* dp, struct regional* regional, + struct ub_packed_rrset_key* rrset, uint8_t lame); + +/** + * Add any RRset to delegpt. + * Does not check for duplicates added. + * @param dp: delegation point. + * @param regional: where to allocate the info. + * @param rrset: RRset to add, NS, A, AAAA. + * @param lame: rrset is lame, disprefer it. + * @return 0 on alloc error. + */ +int delegpt_add_rrset(struct delegpt* dp, struct regional* regional, + struct ub_packed_rrset_key* rrset, uint8_t lame); + +/** + * Add address to the delegation point. No servername is associated or checked. + * @param dp: delegation point. + * @param regional: where to allocate the info. + * @param addr: the address. + * @param addrlen: the length of addr. + * @param bogus: if address is bogus. + * @param lame: if address is lame. + * @return false on error. + */ +int delegpt_add_addr(struct delegpt* dp, struct regional* regional, + struct sockaddr_storage* addr, socklen_t addrlen, + uint8_t bogus, uint8_t lame); + +/** + * Find NS record in name list of delegation point. + * @param dp: delegation point. + * @param name: name of nameserver to look for, uncompressed wireformat. + * @param namelen: length of name. + * @return the ns structure or NULL if not found. + */ +struct delegpt_ns* delegpt_find_ns(struct delegpt* dp, uint8_t* name, + size_t namelen); + +/** + * Find address record in total list of delegation point. + * @param dp: delegation point. + * @param addr: address + * @param addrlen: length of addr + * @return the addr structure or NULL if not found. + */ +struct delegpt_addr* delegpt_find_addr(struct delegpt* dp, + struct sockaddr_storage* addr, socklen_t addrlen); + +/** + * Print the delegation point to the log. For debugging. + * @param v: verbosity value that is needed to emit to log. + * @param dp: delegation point. + */ +void delegpt_log(enum verbosity_value v, struct delegpt* dp); + +/** count NS and number missing for logging */ +void delegpt_count_ns(struct delegpt* dp, size_t* numns, size_t* missing); + +/** count addresses, and number in result and available lists, for logging */ +void delegpt_count_addr(struct delegpt* dp, size_t* numaddr, size_t* numres, + size_t* numavail); + +/** + * Add all usable targets to the result list. + * @param dp: delegation point. + */ +void delegpt_add_unused_targets(struct delegpt* dp); + +/** + * Count number of missing targets. These are ns names with no resolved flag. + * @param dp: delegation point. + * @return number of missing targets (or 0). + */ +size_t delegpt_count_missing_targets(struct delegpt* dp); + +/** count total number of targets in dp */ +size_t delegpt_count_targets(struct delegpt* dp); + +/** + * Create new delegation point from a dns message + * + * Note that this method does not actually test to see if the message is an + * actual referral. It really is just checking to see if it can construct a + * delegation point, so the message could be of some other type (some ANSWER + * messages, some CNAME messages, generally.) Note that the resulting + * DelegationPoint will contain targets for all "relevant" glue (i.e., + * address records whose ownernames match the target of one of the NS + * records), so if policy dictates that some glue should be discarded beyond + * that, discard it before calling this method. Note that this method will + * find "glue" in either the ADDITIONAL section or the ANSWER section. + * + * @param msg: the dns message, referral. + * @param regional: where to allocate delegation point. + * @return new delegation point or NULL on alloc error, or if the + * message was not appropriate. + */ +struct delegpt* delegpt_from_message(struct dns_msg* msg, + struct regional* regional); + +/** + * Add negative message to delegation point. + * @param dp: delegation point. + * @param msg: the message added, marks off A or AAAA from an NS entry. + */ +void delegpt_add_neg_msg(struct delegpt* dp, struct msgreply_entry* msg); + +/** + * Register the fact that there is no ipv6 and thus AAAAs are not going + * to be queried for or be useful. + * @param dp: the delegation point. Updated to reflect no ipv6. + */ +void delegpt_no_ipv6(struct delegpt* dp); + +/** + * Register the fact that there is no ipv4 and thus As are not going + * to be queried for or be useful. + * @param dp: the delegation point. Updated to reflect no ipv4. + */ +void delegpt_no_ipv4(struct delegpt* dp); + +/** + * create malloced delegation point, with the given name + * @param name: uncompressed wireformat of degegpt name. + * @return NULL on alloc failure + */ +struct delegpt* delegpt_create_mlc(uint8_t* name); + +/** + * free malloced delegation point. + * @param dp: must have been created with delegpt_create_mlc, free'd. + */ +void delegpt_free_mlc(struct delegpt* dp); + +/** + * Set name of delegation point. + * @param dp: delegation point. malloced. + * @param name: name to use. + * @return false on error. + */ +int delegpt_set_name_mlc(struct delegpt* dp, uint8_t* name); + +/** + * add a name to malloced delegation point. + * @param dp: must have been created with delegpt_create_mlc. + * @param name: the name to add. + * @param lame: the name is lame, disprefer. + * @return false on error. + */ +int delegpt_add_ns_mlc(struct delegpt* dp, uint8_t* name, uint8_t lame); + +/** + * add an address to a malloced delegation point. + * @param dp: must have been created with delegpt_create_mlc. + * @param addr: the address. + * @param addrlen: the length of addr. + * @param bogus: if address is bogus. + * @param lame: if address is lame. + * @return false on error. + */ +int delegpt_add_addr_mlc(struct delegpt* dp, struct sockaddr_storage* addr, + socklen_t addrlen, uint8_t bogus, uint8_t lame); + +/** + * Add target address to the delegation point. + * @param dp: must have been created with delegpt_create_mlc. + * @param name: name for which target was found (must be in nslist). + * This name is marked resolved. + * @param namelen: length of name. + * @param addr: the address. + * @param addrlen: the length of addr. + * @param bogus: security status for the address, pass true if bogus. + * @param lame: address is lame. + * @return false on error. + */ +int delegpt_add_target_mlc(struct delegpt* dp, uint8_t* name, size_t namelen, + struct sockaddr_storage* addr, socklen_t addrlen, uint8_t bogus, + uint8_t lame); + +/** get memory in use by dp */ +size_t delegpt_get_mem(struct delegpt* dp); + +#endif /* ITERATOR_ITER_DELEGPT_H */ diff --git a/external/unbound/iterator/iter_donotq.c b/external/unbound/iterator/iter_donotq.c new file mode 100644 index 000000000..40ffb45c4 --- /dev/null +++ b/external/unbound/iterator/iter_donotq.c @@ -0,0 +1,153 @@ +/* + * iterator/iter_donotq.c - iterative resolver donotqueryaddresses storage. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file contains functions to assist the iterator module. + * The donotqueryaddresses are stored and looked up. These addresses + * (like 127.0.0.1) must not be used to send queries to, and can be + * discarded immediately from the server selection. + */ +#include "config.h" +#include "iterator/iter_donotq.h" +#include "util/regional.h" +#include "util/log.h" +#include "util/config_file.h" +#include "util/net_help.h" + +struct iter_donotq* +donotq_create(void) +{ + struct iter_donotq* dq = (struct iter_donotq*)calloc(1, + sizeof(struct iter_donotq)); + if(!dq) + return NULL; + dq->region = regional_create(); + if(!dq->region) { + donotq_delete(dq); + return NULL; + } + return dq; +} + +void +donotq_delete(struct iter_donotq* dq) +{ + if(!dq) + return; + regional_destroy(dq->region); + free(dq); +} + +/** insert new address into donotq structure */ +static int +donotq_insert(struct iter_donotq* dq, struct sockaddr_storage* addr, + socklen_t addrlen, int net) +{ + struct addr_tree_node* node = (struct addr_tree_node*)regional_alloc( + dq->region, sizeof(*node)); + if(!node) + return 0; + if(!addr_tree_insert(&dq->tree, node, addr, addrlen, net)) { + verbose(VERB_QUERY, "duplicate donotquery address ignored."); + } + return 1; +} + +/** apply donotq string */ +static int +donotq_str_cfg(struct iter_donotq* dq, const char* str) +{ + struct sockaddr_storage addr; + int net; + socklen_t addrlen; + verbose(VERB_ALGO, "donotq: %s", str); + if(!netblockstrtoaddr(str, UNBOUND_DNS_PORT, &addr, &addrlen, &net)) { + log_err("cannot parse donotquery netblock: %s", str); + return 0; + } + if(!donotq_insert(dq, &addr, addrlen, net)) { + log_err("out of memory"); + return 0; + } + return 1; +} + +/** read donotq config */ +static int +read_donotq(struct iter_donotq* dq, struct config_file* cfg) +{ + struct config_strlist* p; + for(p = cfg->donotqueryaddrs; p; p = p->next) { + log_assert(p->str); + if(!donotq_str_cfg(dq, p->str)) + return 0; + } + return 1; +} + +int +donotq_apply_cfg(struct iter_donotq* dq, struct config_file* cfg) +{ + regional_free_all(dq->region); + addr_tree_init(&dq->tree); + if(!read_donotq(dq, cfg)) + return 0; + if(cfg->donotquery_localhost) { + if(!donotq_str_cfg(dq, "127.0.0.0/8")) + return 0; + if(cfg->do_ip6) { + if(!donotq_str_cfg(dq, "::1")) + return 0; + } + } + addr_tree_init_parents(&dq->tree); + return 1; +} + +int +donotq_lookup(struct iter_donotq* donotq, struct sockaddr_storage* addr, + socklen_t addrlen) +{ + return addr_tree_lookup(&donotq->tree, addr, addrlen) != NULL; +} + +size_t +donotq_get_mem(struct iter_donotq* donotq) +{ + if(!donotq) return 0; + return sizeof(*donotq) + regional_get_mem(donotq->region); +} diff --git a/external/unbound/iterator/iter_donotq.h b/external/unbound/iterator/iter_donotq.h new file mode 100644 index 000000000..429e5a3dd --- /dev/null +++ b/external/unbound/iterator/iter_donotq.h @@ -0,0 +1,101 @@ +/* + * iterator/iter_donotq.h - iterative resolver donotqueryaddresses storage. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file contains functions to assist the iterator module. + * Keep track of the donotquery addresses and lookup fast. + */ + +#ifndef ITERATOR_ITER_DONOTQ_H +#define ITERATOR_ITER_DONOTQ_H +#include "util/storage/dnstree.h" +struct iter_env; +struct config_file; +struct regional; + +/** + * Iterator donotqueryaddresses structure + */ +struct iter_donotq { + /** regional for allocation */ + struct regional* region; + /** + * Tree of the address spans that are blocked. + * contents of type addr_tree_node. Each node is an address span + * that must not be used to send queries to. + */ + rbtree_t tree; +}; + +/** + * Create donotqueryaddresses structure + * @return new structure or NULL on error. + */ +struct iter_donotq* donotq_create(void); + +/** + * Delete donotqueryaddresses structure. + * @param donotq: to delete. + */ +void donotq_delete(struct iter_donotq* donotq); + +/** + * Process donotqueryaddresses config. + * @param donotq: where to store. + * @param cfg: config options. + * @return 0 on error. + */ +int donotq_apply_cfg(struct iter_donotq* donotq, struct config_file* cfg); + +/** + * See if an address is blocked. + * @param donotq: structure for address storage. + * @param addr: address to check + * @param addrlen: length of addr. + * @return: true if the address must not be queried. false if unlisted. + */ +int donotq_lookup(struct iter_donotq* donotq, struct sockaddr_storage* addr, + socklen_t addrlen); + +/** + * Get memory used by donotqueryaddresses structure. + * @param donotq: structure for address storage. + * @return bytes in use. + */ +size_t donotq_get_mem(struct iter_donotq* donotq); + +#endif /* ITERATOR_ITER_DONOTQ_H */ diff --git a/external/unbound/iterator/iter_fwd.c b/external/unbound/iterator/iter_fwd.c new file mode 100644 index 000000000..012121241 --- /dev/null +++ b/external/unbound/iterator/iter_fwd.c @@ -0,0 +1,506 @@ +/* + * iterator/iter_fwd.c - iterative resolver module forward zones. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file contains functions to assist the iterator module. + * Keep track of forward zones and config settings. + */ +#include "config.h" +#include "iterator/iter_fwd.h" +#include "iterator/iter_delegpt.h" +#include "util/log.h" +#include "util/config_file.h" +#include "util/net_help.h" +#include "util/data/dname.h" +#include "ldns/rrdef.h" +#include "ldns/str2wire.h" + +int +fwd_cmp(const void* k1, const void* k2) +{ + int m; + struct iter_forward_zone* n1 = (struct iter_forward_zone*)k1; + struct iter_forward_zone* n2 = (struct iter_forward_zone*)k2; + if(n1->dclass != n2->dclass) { + if(n1->dclass < n2->dclass) + return -1; + return 1; + } + return dname_lab_cmp(n1->name, n1->namelabs, n2->name, n2->namelabs, + &m); +} + +struct iter_forwards* +forwards_create(void) +{ + struct iter_forwards* fwd = (struct iter_forwards*)calloc(1, + sizeof(struct iter_forwards)); + if(!fwd) + return NULL; + return fwd; +} + +static void fwd_zone_free(struct iter_forward_zone* n) +{ + if(!n) return; + delegpt_free_mlc(n->dp); + free(n->name); + free(n); +} + +static void delfwdnode(rbnode_t* n, void* ATTR_UNUSED(arg)) +{ + struct iter_forward_zone* node = (struct iter_forward_zone*)n; + fwd_zone_free(node); +} + +static void fwd_del_tree(struct iter_forwards* fwd) +{ + if(fwd->tree) + traverse_postorder(fwd->tree, &delfwdnode, NULL); + free(fwd->tree); +} + +void +forwards_delete(struct iter_forwards* fwd) +{ + if(!fwd) + return; + fwd_del_tree(fwd); + free(fwd); +} + +/** insert info into forward structure */ +static int +forwards_insert_data(struct iter_forwards* fwd, uint16_t c, uint8_t* nm, + size_t nmlen, int nmlabs, struct delegpt* dp) +{ + struct iter_forward_zone* node = (struct iter_forward_zone*)malloc( + sizeof(struct iter_forward_zone)); + if(!node) { + delegpt_free_mlc(dp); + return 0; + } + node->node.key = node; + node->dclass = c; + node->name = memdup(nm, nmlen); + if(!node->name) { + delegpt_free_mlc(dp); + free(node); + return 0; + } + node->namelen = nmlen; + node->namelabs = nmlabs; + node->dp = dp; + if(!rbtree_insert(fwd->tree, &node->node)) { + char buf[257]; + dname_str(nm, buf); + log_err("duplicate forward zone %s ignored.", buf); + delegpt_free_mlc(dp); + free(node->name); + free(node); + } + return 1; +} + +/** insert new info into forward structure given dp */ +static int +forwards_insert(struct iter_forwards* fwd, uint16_t c, struct delegpt* dp) +{ + return forwards_insert_data(fwd, c, dp->name, dp->namelen, + dp->namelabs, dp); +} + +/** initialise parent pointers in the tree */ +static void +fwd_init_parents(struct iter_forwards* fwd) +{ + struct iter_forward_zone* node, *prev = NULL, *p; + int m; + RBTREE_FOR(node, struct iter_forward_zone*, fwd->tree) { + node->parent = NULL; + if(!prev || prev->dclass != node->dclass) { + prev = node; + continue; + } + (void)dname_lab_cmp(prev->name, prev->namelabs, node->name, + node->namelabs, &m); /* we know prev is smaller */ + /* sort order like: . com. bla.com. zwb.com. net. */ + /* find the previous, or parent-parent-parent */ + for(p = prev; p; p = p->parent) + /* looking for name with few labels, a parent */ + if(p->namelabs <= m) { + /* ==: since prev matched m, this is closest*/ + /* <: prev matches more, but is not a parent, + * this one is a (grand)parent */ + node->parent = p; + break; + } + prev = node; + } +} + +/** set zone name */ +static struct delegpt* +read_fwds_name(struct config_stub* s) +{ + struct delegpt* dp; + uint8_t* dname; + size_t dname_len; + if(!s->name) { + log_err("forward zone without a name (use name \".\" to forward everything)"); + return NULL; + } + dname = sldns_str2wire_dname(s->name, &dname_len); + if(!dname) { + log_err("cannot parse forward zone name %s", s->name); + return NULL; + } + if(!(dp=delegpt_create_mlc(dname))) { + free(dname); + log_err("out of memory"); + return NULL; + } + free(dname); + return dp; +} + +/** set fwd host names */ +static int +read_fwds_host(struct config_stub* s, struct delegpt* dp) +{ + struct config_strlist* p; + uint8_t* dname; + size_t dname_len; + for(p = s->hosts; p; p = p->next) { + log_assert(p->str); + dname = sldns_str2wire_dname(p->str, &dname_len); + if(!dname) { + log_err("cannot parse forward %s server name: '%s'", + s->name, p->str); + return 0; + } + if(!delegpt_add_ns_mlc(dp, dname, 0)) { + free(dname); + log_err("out of memory"); + return 0; + } + free(dname); + } + return 1; +} + +/** set fwd server addresses */ +static int +read_fwds_addr(struct config_stub* s, struct delegpt* dp) +{ + struct config_strlist* p; + struct sockaddr_storage addr; + socklen_t addrlen; + for(p = s->addrs; p; p = p->next) { + log_assert(p->str); + if(!extstrtoaddr(p->str, &addr, &addrlen)) { + log_err("cannot parse forward %s ip address: '%s'", + s->name, p->str); + return 0; + } + if(!delegpt_add_addr_mlc(dp, &addr, addrlen, 0, 0)) { + log_err("out of memory"); + return 0; + } + } + return 1; +} + +/** read forwards config */ +static int +read_forwards(struct iter_forwards* fwd, struct config_file* cfg) +{ + struct config_stub* s; + for(s = cfg->forwards; s; s = s->next) { + struct delegpt* dp; + if(!(dp=read_fwds_name(s))) + return 0; + if(!read_fwds_host(s, dp) || !read_fwds_addr(s, dp)) { + delegpt_free_mlc(dp); + return 0; + } + /* set flag that parent side NS information is included. + * Asking a (higher up) server on the internet is not useful */ + /* the flag is turned off for 'forward-first' so that the + * last resort will ask for parent-side NS record and thus + * fallback to the internet name servers on a failure */ + dp->has_parent_side_NS = (uint8_t)!s->isfirst; + verbose(VERB_QUERY, "Forward zone server list:"); + delegpt_log(VERB_QUERY, dp); + if(!forwards_insert(fwd, LDNS_RR_CLASS_IN, dp)) + return 0; + } + return 1; +} + +/** insert a stub hole (if necessary) for stub name */ +static int +fwd_add_stub_hole(struct iter_forwards* fwd, uint16_t c, uint8_t* nm) +{ + struct iter_forward_zone key; + key.node.key = &key; + key.dclass = c; + key.name = nm; + key.namelabs = dname_count_size_labels(key.name, &key.namelen); + return forwards_insert_data(fwd, key.dclass, key.name, + key.namelen, key.namelabs, NULL); +} + +/** make NULL entries for stubs */ +static int +make_stub_holes(struct iter_forwards* fwd, struct config_file* cfg) +{ + struct config_stub* s; + uint8_t* dname; + size_t dname_len; + for(s = cfg->stubs; s; s = s->next) { + dname = sldns_str2wire_dname(s->name, &dname_len); + if(!dname) { + log_err("cannot parse stub name '%s'", s->name); + return 0; + } + if(!fwd_add_stub_hole(fwd, LDNS_RR_CLASS_IN, dname)) { + free(dname); + log_err("out of memory"); + return 0; + } + free(dname); + } + return 1; +} + +int +forwards_apply_cfg(struct iter_forwards* fwd, struct config_file* cfg) +{ + fwd_del_tree(fwd); + fwd->tree = rbtree_create(fwd_cmp); + if(!fwd->tree) + return 0; + + /* read forward zones */ + if(!read_forwards(fwd, cfg)) + return 0; + if(!make_stub_holes(fwd, cfg)) + return 0; + fwd_init_parents(fwd); + return 1; +} + +struct delegpt* +forwards_find(struct iter_forwards* fwd, uint8_t* qname, uint16_t qclass) +{ + rbnode_t* res = NULL; + struct iter_forward_zone key; + key.node.key = &key; + key.dclass = qclass; + key.name = qname; + key.namelabs = dname_count_size_labels(qname, &key.namelen); + res = rbtree_search(fwd->tree, &key); + if(res) return ((struct iter_forward_zone*)res)->dp; + return NULL; +} + +struct delegpt* +forwards_lookup(struct iter_forwards* fwd, uint8_t* qname, uint16_t qclass) +{ + /* lookup the forward zone in the tree */ + rbnode_t* res = NULL; + struct iter_forward_zone *result; + struct iter_forward_zone key; + key.node.key = &key; + key.dclass = qclass; + key.name = qname; + key.namelabs = dname_count_size_labels(qname, &key.namelen); + if(rbtree_find_less_equal(fwd->tree, &key, &res)) { + /* exact */ + result = (struct iter_forward_zone*)res; + } else { + /* smaller element (or no element) */ + int m; + result = (struct iter_forward_zone*)res; + if(!result || result->dclass != qclass) + return NULL; + /* count number of labels matched */ + (void)dname_lab_cmp(result->name, result->namelabs, key.name, + key.namelabs, &m); + while(result) { /* go up until qname is subdomain of stub */ + if(result->namelabs <= m) + break; + result = result->parent; + } + } + if(result) + return result->dp; + return NULL; +} + +struct delegpt* +forwards_lookup_root(struct iter_forwards* fwd, uint16_t qclass) +{ + uint8_t root = 0; + return forwards_lookup(fwd, &root, qclass); +} + +int +forwards_next_root(struct iter_forwards* fwd, uint16_t* dclass) +{ + struct iter_forward_zone key; + rbnode_t* n; + struct iter_forward_zone* p; + if(*dclass == 0) { + /* first root item is first item in tree */ + n = rbtree_first(fwd->tree); + if(n == RBTREE_NULL) + return 0; + p = (struct iter_forward_zone*)n; + if(dname_is_root(p->name)) { + *dclass = p->dclass; + return 1; + } + /* root not first item? search for higher items */ + *dclass = p->dclass + 1; + return forwards_next_root(fwd, dclass); + } + /* find class n in tree, we may get a direct hit, or if we don't + * this is the last item of the previous class so rbtree_next() takes + * us to the next root (if any) */ + key.node.key = &key; + key.name = (uint8_t*)"\000"; + key.namelen = 1; + key.namelabs = 0; + key.dclass = *dclass; + n = NULL; + if(rbtree_find_less_equal(fwd->tree, &key, &n)) { + /* exact */ + return 1; + } else { + /* smaller element */ + if(!n || n == RBTREE_NULL) + return 0; /* nothing found */ + n = rbtree_next(n); + if(n == RBTREE_NULL) + return 0; /* no higher */ + p = (struct iter_forward_zone*)n; + if(dname_is_root(p->name)) { + *dclass = p->dclass; + return 1; + } + /* not a root node, return next higher item */ + *dclass = p->dclass+1; + return forwards_next_root(fwd, dclass); + } +} + +size_t +forwards_get_mem(struct iter_forwards* fwd) +{ + struct iter_forward_zone* p; + size_t s; + if(!fwd) + return 0; + s = sizeof(*fwd) + sizeof(*fwd->tree); + RBTREE_FOR(p, struct iter_forward_zone*, fwd->tree) { + s += sizeof(*p) + p->namelen + delegpt_get_mem(p->dp); + } + return s; +} + +static struct iter_forward_zone* +fwd_zone_find(struct iter_forwards* fwd, uint16_t c, uint8_t* nm) +{ + struct iter_forward_zone key; + key.node.key = &key; + key.dclass = c; + key.name = nm; + key.namelabs = dname_count_size_labels(nm, &key.namelen); + return (struct iter_forward_zone*)rbtree_search(fwd->tree, &key); +} + +int +forwards_add_zone(struct iter_forwards* fwd, uint16_t c, struct delegpt* dp) +{ + struct iter_forward_zone *z; + if((z=fwd_zone_find(fwd, c, dp->name)) != NULL) { + (void)rbtree_delete(fwd->tree, &z->node); + fwd_zone_free(z); + } + if(!forwards_insert(fwd, c, dp)) + return 0; + fwd_init_parents(fwd); + return 1; +} + +void +forwards_delete_zone(struct iter_forwards* fwd, uint16_t c, uint8_t* nm) +{ + struct iter_forward_zone *z; + if(!(z=fwd_zone_find(fwd, c, nm))) + return; /* nothing to do */ + (void)rbtree_delete(fwd->tree, &z->node); + fwd_zone_free(z); + fwd_init_parents(fwd); +} + +int +forwards_add_stub_hole(struct iter_forwards* fwd, uint16_t c, uint8_t* nm) +{ + if(!fwd_add_stub_hole(fwd, c, nm)) { + return 0; + } + fwd_init_parents(fwd); + return 1; +} + +void +forwards_delete_stub_hole(struct iter_forwards* fwd, uint16_t c, uint8_t* nm) +{ + struct iter_forward_zone *z; + if(!(z=fwd_zone_find(fwd, c, nm))) + return; /* nothing to do */ + if(z->dp != NULL) + return; /* not a stub hole */ + (void)rbtree_delete(fwd->tree, &z->node); + fwd_zone_free(z); + fwd_init_parents(fwd); +} + diff --git a/external/unbound/iterator/iter_fwd.h b/external/unbound/iterator/iter_fwd.h new file mode 100644 index 000000000..20113a395 --- /dev/null +++ b/external/unbound/iterator/iter_fwd.h @@ -0,0 +1,199 @@ +/* + * iterator/iter_fwd.h - iterative resolver module forward zones. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file contains functions to assist the iterator module. + * Keep track of forward zones, and read those from config. + */ + +#ifndef ITERATOR_ITER_FWD_H +#define ITERATOR_ITER_FWD_H +#include "util/rbtree.h" +struct config_file; +struct delegpt; + +/** + * Iterator forward zones structure + */ +struct iter_forwards { + /** + * Zones are stored in this tree. Sort order is specially chosen. + * first sorted on qclass. Then on dname in nsec-like order, so that + * a lookup on class, name will return an exact match or the closest + * match which gives the ancestor needed. + * contents of type iter_forward_zone. + */ + rbtree_t* tree; +}; + +/** + * Iterator forward servers for a particular zone. + */ +struct iter_forward_zone { + /** redblacktree node, key is this structure: class and name */ + rbnode_t node; + /** name */ + uint8_t* name; + /** length of name */ + size_t namelen; + /** number of labels in name */ + int namelabs; + /** delegation point with forward server information for this zone. + * If NULL then this forward entry is used to indicate that a + * stub-zone with the same name exists, and should be used. + * This delegation point is malloced. + */ + struct delegpt* dp; + /** pointer to parent in tree (or NULL if none) */ + struct iter_forward_zone* parent; + /** class. host order. */ + uint16_t dclass; +}; + +/** + * Create forwards + * @return new forwards or NULL on error. + */ +struct iter_forwards* forwards_create(void); + +/** + * Delete forwards. + * @param fwd: to delete. + */ +void forwards_delete(struct iter_forwards* fwd); + +/** + * Process forwards config. + * @param fwd: where to store. + * @param cfg: config options. + * @return 0 on error. + */ +int forwards_apply_cfg(struct iter_forwards* fwd, struct config_file* cfg); + +/** + * Find forward zone exactly by name + * @param fwd: forward storage. + * @param qname: The qname of the query. + * @param qclass: The qclass of the query. + * @return: A delegation point or null. + */ +struct delegpt* forwards_find(struct iter_forwards* fwd, uint8_t* qname, + uint16_t qclass); + +/** + * Find forward zone information + * For this qname/qclass find forward zone information, returns delegation + * point with server names and addresses, or NULL if no forwarding is needed. + * + * @param fwd: forward storage. + * @param qname: The qname of the query. + * @param qclass: The qclass of the query. + * @return: A delegation point if the query has to be forwarded to that list, + * otherwise null. + */ +struct delegpt* forwards_lookup(struct iter_forwards* fwd, + uint8_t* qname, uint16_t qclass); + +/** + * Same as forwards_lookup, but for the root only + * @param fwd: forward storage. + * @param qclass: The qclass of the query. + * @return: A delegation point if root forward exists, otherwise null. + */ +struct delegpt* forwards_lookup_root(struct iter_forwards* fwd, + uint16_t qclass); + +/** + * Find next root item in forwards lookup tree. + * @param fwd: the forward storage + * @param qclass: class to look at next, or higher. + * @return false if none found, or if true stored in qclass. + */ +int forwards_next_root(struct iter_forwards* fwd, uint16_t* qclass); + +/** + * Get memory in use by forward storage + * @param fwd: forward storage. + * @return bytes in use + */ +size_t forwards_get_mem(struct iter_forwards* fwd); + +/** compare two fwd entries */ +int fwd_cmp(const void* k1, const void* k2); + +/** + * Add zone to forward structure. For external use since it recalcs + * the tree parents. + * @param fwd: the forward data structure + * @param c: class of zone + * @param dp: delegation point with name and target nameservers for new + * forward zone. malloced. + * @return false on failure (out of memory); + */ +int forwards_add_zone(struct iter_forwards* fwd, uint16_t c, + struct delegpt* dp); + +/** + * Remove zone from forward structure. For external use since it + * recalcs the tree parents. + * @param fwd: the forward data structure + * @param c: class of zone + * @param nm: name of zone (in uncompressed wireformat). + */ +void forwards_delete_zone(struct iter_forwards* fwd, uint16_t c, uint8_t* nm); + +/** + * Add stub hole (empty entry in forward table, that makes resolution skip + * a forward-zone because the stub zone should override the forward zone). + * Does not add one if not necessary. + * @param fwd: the forward data structure + * @param c: class of zone + * @param nm: name of zone (in uncompressed wireformat). + * @return false on failure (out of memory); + */ +int forwards_add_stub_hole(struct iter_forwards* fwd, uint16_t c, uint8_t* nm); + +/** + * Remove stub hole, if one exists. + * @param fwd: the forward data structure + * @param c: class of zone + * @param nm: name of zone (in uncompressed wireformat). + */ +void forwards_delete_stub_hole(struct iter_forwards* fwd, uint16_t c, + uint8_t* nm); + +#endif /* ITERATOR_ITER_FWD_H */ diff --git a/external/unbound/iterator/iter_hints.c b/external/unbound/iterator/iter_hints.c new file mode 100644 index 000000000..57b57c2e0 --- /dev/null +++ b/external/unbound/iterator/iter_hints.c @@ -0,0 +1,542 @@ +/* + * iterator/iter_hints.c - iterative resolver module stub and root hints. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file contains functions to assist the iterator module. + * Keep track of stub and root hints, and read those from config. + */ +#include "config.h" +#include "iterator/iter_hints.h" +#include "iterator/iter_delegpt.h" +#include "util/log.h" +#include "util/config_file.h" +#include "util/net_help.h" +#include "util/data/dname.h" +#include "ldns/rrdef.h" +#include "ldns/str2wire.h" +#include "ldns/wire2str.h" + +struct iter_hints* +hints_create(void) +{ + struct iter_hints* hints = (struct iter_hints*)calloc(1, + sizeof(struct iter_hints)); + if(!hints) + return NULL; + return hints; +} + +static void hints_stub_free(struct iter_hints_stub* s) +{ + if(!s) return; + delegpt_free_mlc(s->dp); + free(s); +} + +static void delhintnode(rbnode_t* n, void* ATTR_UNUSED(arg)) +{ + struct iter_hints_stub* node = (struct iter_hints_stub*)n; + hints_stub_free(node); +} + +static void hints_del_tree(struct iter_hints* hints) +{ + traverse_postorder(&hints->tree, &delhintnode, NULL); +} + +void +hints_delete(struct iter_hints* hints) +{ + if(!hints) + return; + hints_del_tree(hints); + free(hints); +} + +/** add hint to delegation hints */ +static int +ah(struct delegpt* dp, const char* sv, const char* ip) +{ + struct sockaddr_storage addr; + socklen_t addrlen; + size_t dname_len; + uint8_t* dname = sldns_str2wire_dname(sv, &dname_len); + if(!dname) { + log_err("could not parse %s", sv); + return 0; + } + if(!delegpt_add_ns_mlc(dp, dname, 0) || + !extstrtoaddr(ip, &addr, &addrlen) || + !delegpt_add_target_mlc(dp, dname, dname_len, + &addr, addrlen, 0, 0)) { + free(dname); + return 0; + } + free(dname); + return 1; +} + +/** obtain compiletime provided root hints */ +static struct delegpt* +compile_time_root_prime(int do_ip4, int do_ip6) +{ + /* from: + ; This file is made available by InterNIC + ; under anonymous FTP as + ; file /domain/named.cache + ; on server FTP.INTERNIC.NET + ; -OR- RS.INTERNIC.NET + ; + ; related version of root zone: changes-on-20120103 + */ + struct delegpt* dp = delegpt_create_mlc((uint8_t*)"\000"); + if(!dp) + return NULL; + dp->has_parent_side_NS = 1; + if(do_ip4) { + if(!ah(dp, "A.ROOT-SERVERS.NET.", "198.41.0.4")) goto failed; + if(!ah(dp, "B.ROOT-SERVERS.NET.", "192.228.79.201")) goto failed; + if(!ah(dp, "C.ROOT-SERVERS.NET.", "192.33.4.12")) goto failed; + if(!ah(dp, "D.ROOT-SERVERS.NET.", "199.7.91.13")) goto failed; + if(!ah(dp, "E.ROOT-SERVERS.NET.", "192.203.230.10")) goto failed; + if(!ah(dp, "F.ROOT-SERVERS.NET.", "192.5.5.241")) goto failed; + if(!ah(dp, "G.ROOT-SERVERS.NET.", "192.112.36.4")) goto failed; + if(!ah(dp, "H.ROOT-SERVERS.NET.", "128.63.2.53")) goto failed; + if(!ah(dp, "I.ROOT-SERVERS.NET.", "192.36.148.17")) goto failed; + if(!ah(dp, "J.ROOT-SERVERS.NET.", "192.58.128.30")) goto failed; + if(!ah(dp, "K.ROOT-SERVERS.NET.", "193.0.14.129")) goto failed; + if(!ah(dp, "L.ROOT-SERVERS.NET.", "199.7.83.42")) goto failed; + if(!ah(dp, "M.ROOT-SERVERS.NET.", "202.12.27.33")) goto failed; + } + if(do_ip6) { + if(!ah(dp, "A.ROOT-SERVERS.NET.", "2001:503:ba3e::2:30")) goto failed; + if(!ah(dp, "B.ROOT-SERVERS.NET.", "2001:500:84::b")) goto failed; + if(!ah(dp, "C.ROOT-SERVERS.NET.", "2001:500:2::c")) goto failed; + if(!ah(dp, "D.ROOT-SERVERS.NET.", "2001:500:2d::d")) goto failed; + if(!ah(dp, "F.ROOT-SERVERS.NET.", "2001:500:2f::f")) goto failed; + if(!ah(dp, "H.ROOT-SERVERS.NET.", "2001:500:1::803f:235")) goto failed; + if(!ah(dp, "I.ROOT-SERVERS.NET.", "2001:7fe::53")) goto failed; + if(!ah(dp, "J.ROOT-SERVERS.NET.", "2001:503:c27::2:30")) goto failed; + if(!ah(dp, "K.ROOT-SERVERS.NET.", "2001:7fd::1")) goto failed; + if(!ah(dp, "L.ROOT-SERVERS.NET.", "2001:500:3::42")) goto failed; + if(!ah(dp, "M.ROOT-SERVERS.NET.", "2001:dc3::35")) goto failed; + } + return dp; +failed: + delegpt_free_mlc(dp); + return 0; +} + +/** insert new hint info into hint structure */ +static int +hints_insert(struct iter_hints* hints, uint16_t c, struct delegpt* dp, + int noprime) +{ + struct iter_hints_stub* node = (struct iter_hints_stub*)malloc( + sizeof(struct iter_hints_stub)); + if(!node) { + delegpt_free_mlc(dp); + return 0; + } + node->dp = dp; + node->noprime = (uint8_t)noprime; + if(!name_tree_insert(&hints->tree, &node->node, dp->name, dp->namelen, + dp->namelabs, c)) { + char buf[257]; + dname_str(dp->name, buf); + log_err("second hints for zone %s ignored.", buf); + delegpt_free_mlc(dp); + free(node); + } + return 1; +} + +/** set stub name */ +static struct delegpt* +read_stubs_name(struct config_stub* s) +{ + struct delegpt* dp; + size_t dname_len; + uint8_t* dname; + if(!s->name) { + log_err("stub zone without a name"); + return NULL; + } + dname = sldns_str2wire_dname(s->name, &dname_len); + if(!dname) { + log_err("cannot parse stub zone name %s", s->name); + return NULL; + } + if(!(dp=delegpt_create_mlc(dname))) { + free(dname); + log_err("out of memory"); + return NULL; + } + free(dname); + return dp; +} + +/** set stub host names */ +static int +read_stubs_host(struct config_stub* s, struct delegpt* dp) +{ + struct config_strlist* p; + size_t dname_len; + uint8_t* dname; + for(p = s->hosts; p; p = p->next) { + log_assert(p->str); + dname = sldns_str2wire_dname(p->str, &dname_len); + if(!dname) { + log_err("cannot parse stub %s nameserver name: '%s'", + s->name, p->str); + return 0; + } + if(!delegpt_add_ns_mlc(dp, dname, 0)) { + free(dname); + log_err("out of memory"); + return 0; + } + free(dname); + } + return 1; +} + +/** set stub server addresses */ +static int +read_stubs_addr(struct config_stub* s, struct delegpt* dp) +{ + struct config_strlist* p; + struct sockaddr_storage addr; + socklen_t addrlen; + for(p = s->addrs; p; p = p->next) { + log_assert(p->str); + if(!extstrtoaddr(p->str, &addr, &addrlen)) { + log_err("cannot parse stub %s ip address: '%s'", + s->name, p->str); + return 0; + } + if(!delegpt_add_addr_mlc(dp, &addr, addrlen, 0, 0)) { + log_err("out of memory"); + return 0; + } + } + return 1; +} + +/** read stubs config */ +static int +read_stubs(struct iter_hints* hints, struct config_file* cfg) +{ + struct config_stub* s; + struct delegpt* dp; + for(s = cfg->stubs; s; s = s->next) { + if(!(dp=read_stubs_name(s))) + return 0; + if(!read_stubs_host(s, dp) || !read_stubs_addr(s, dp)) { + delegpt_free_mlc(dp); + return 0; + } + /* the flag is turned off for 'stub-first' so that the + * last resort will ask for parent-side NS record and thus + * fallback to the internet name servers on a failure */ + dp->has_parent_side_NS = (uint8_t)!s->isfirst; + delegpt_log(VERB_QUERY, dp); + if(!hints_insert(hints, LDNS_RR_CLASS_IN, dp, !s->isprime)) + return 0; + } + return 1; +} + +/** read root hints from file */ +static int +read_root_hints(struct iter_hints* hints, char* fname) +{ + struct sldns_file_parse_state pstate; + struct delegpt* dp; + uint8_t rr[LDNS_RR_BUF_SIZE]; + size_t rr_len, dname_len; + int status; + uint16_t c = LDNS_RR_CLASS_IN; + FILE* f = fopen(fname, "r"); + if(!f) { + log_err("could not read root hints %s: %s", + fname, strerror(errno)); + return 0; + } + dp = delegpt_create_mlc(NULL); + if(!dp) { + log_err("out of memory reading root hints"); + fclose(f); + return 0; + } + verbose(VERB_QUERY, "Reading root hints from %s", fname); + memset(&pstate, 0, sizeof(pstate)); + pstate.lineno = 1; + dp->has_parent_side_NS = 1; + while(!feof(f)) { + rr_len = sizeof(rr); + dname_len = 0; + status = sldns_fp2wire_rr_buf(f, rr, &rr_len, &dname_len, + &pstate); + if(status != 0) { + log_err("reading root hints %s %d:%d: %s", fname, + pstate.lineno, LDNS_WIREPARSE_OFFSET(status), + sldns_get_errorstr_parse(status)); + goto stop_read; + } + if(rr_len == 0) + continue; /* EMPTY line, TTL or ORIGIN */ + if(sldns_wirerr_get_type(rr, rr_len, dname_len) + == LDNS_RR_TYPE_NS) { + if(!delegpt_add_ns_mlc(dp, sldns_wirerr_get_rdata(rr, + rr_len, dname_len), 0)) { + log_err("out of memory reading root hints"); + goto stop_read; + } + c = sldns_wirerr_get_class(rr, rr_len, dname_len); + if(!dp->name) { + if(!delegpt_set_name_mlc(dp, rr)) { + log_err("out of memory."); + goto stop_read; + } + } + } else if(sldns_wirerr_get_type(rr, rr_len, dname_len) + == LDNS_RR_TYPE_A && sldns_wirerr_get_rdatalen(rr, + rr_len, dname_len) == INET_SIZE) { + struct sockaddr_in sa; + socklen_t len = (socklen_t)sizeof(sa); + memset(&sa, 0, len); + sa.sin_family = AF_INET; + sa.sin_port = (in_port_t)htons(UNBOUND_DNS_PORT); + memmove(&sa.sin_addr, + sldns_wirerr_get_rdata(rr, rr_len, dname_len), + INET_SIZE); + if(!delegpt_add_target_mlc(dp, rr, dname_len, + (struct sockaddr_storage*)&sa, len, + 0, 0)) { + log_err("out of memory reading root hints"); + goto stop_read; + } + } else if(sldns_wirerr_get_type(rr, rr_len, dname_len) + == LDNS_RR_TYPE_AAAA && sldns_wirerr_get_rdatalen(rr, + rr_len, dname_len) == INET6_SIZE) { + struct sockaddr_in6 sa; + socklen_t len = (socklen_t)sizeof(sa); + memset(&sa, 0, len); + sa.sin6_family = AF_INET6; + sa.sin6_port = (in_port_t)htons(UNBOUND_DNS_PORT); + memmove(&sa.sin6_addr, + sldns_wirerr_get_rdata(rr, rr_len, dname_len), + INET6_SIZE); + if(!delegpt_add_target_mlc(dp, rr, dname_len, + (struct sockaddr_storage*)&sa, len, + 0, 0)) { + log_err("out of memory reading root hints"); + goto stop_read; + } + } else { + char buf[17]; + sldns_wire2str_type_buf(sldns_wirerr_get_type(rr, + rr_len, dname_len), buf, sizeof(buf)); + log_warn("root hints %s:%d skipping type %s", + fname, pstate.lineno, buf); + } + } + fclose(f); + if(!dp->name) { + log_warn("root hints %s: no NS content", fname); + delegpt_free_mlc(dp); + return 1; + } + if(!hints_insert(hints, c, dp, 0)) { + return 0; + } + delegpt_log(VERB_QUERY, dp); + return 1; + +stop_read: + delegpt_free_mlc(dp); + fclose(f); + return 0; +} + +/** read root hints list */ +static int +read_root_hints_list(struct iter_hints* hints, struct config_file* cfg) +{ + struct config_strlist* p; + for(p = cfg->root_hints; p; p = p->next) { + log_assert(p->str); + if(p->str && p->str[0]) { + char* f = p->str; + if(cfg->chrootdir && cfg->chrootdir[0] && + strncmp(p->str, cfg->chrootdir, + strlen(cfg->chrootdir)) == 0) + f += strlen(cfg->chrootdir); + if(!read_root_hints(hints, f)) + return 0; + } + } + return 1; +} + +int +hints_apply_cfg(struct iter_hints* hints, struct config_file* cfg) +{ + hints_del_tree(hints); + name_tree_init(&hints->tree); + + /* read root hints */ + if(!read_root_hints_list(hints, cfg)) + return 0; + + /* read stub hints */ + if(!read_stubs(hints, cfg)) + return 0; + + /* use fallback compiletime root hints */ + if(!hints_lookup_root(hints, LDNS_RR_CLASS_IN)) { + struct delegpt* dp = compile_time_root_prime(cfg->do_ip4, + cfg->do_ip6); + verbose(VERB_ALGO, "no config, using builtin root hints."); + if(!dp) + return 0; + if(!hints_insert(hints, LDNS_RR_CLASS_IN, dp, 0)) + return 0; + } + + name_tree_init_parents(&hints->tree); + return 1; +} + +struct delegpt* +hints_lookup_root(struct iter_hints* hints, uint16_t qclass) +{ + uint8_t rootlab = 0; + struct iter_hints_stub *stub; + stub = (struct iter_hints_stub*)name_tree_find(&hints->tree, + &rootlab, 1, 1, qclass); + if(!stub) + return NULL; + return stub->dp; +} + +struct iter_hints_stub* +hints_lookup_stub(struct iter_hints* hints, uint8_t* qname, + uint16_t qclass, struct delegpt* cache_dp) +{ + size_t len; + int labs; + struct iter_hints_stub *r; + + /* first lookup the stub */ + labs = dname_count_size_labels(qname, &len); + r = (struct iter_hints_stub*)name_tree_lookup(&hints->tree, qname, + len, labs, qclass); + if(!r) return NULL; + + /* If there is no cache (root prime situation) */ + if(cache_dp == NULL) { + if(r->dp->namelabs != 1) + return r; /* no cache dp, use any non-root stub */ + return NULL; + } + + /* + * If the stub is same as the delegation we got + * And has noprime set, we need to 'prime' to use this stub instead. + */ + if(r->noprime && query_dname_compare(cache_dp->name, r->dp->name)==0) + return r; /* use this stub instead of cached dp */ + + /* + * If our cached delegation point is above the hint, we need to prime. + */ + if(dname_strict_subdomain(r->dp->name, r->dp->namelabs, + cache_dp->name, cache_dp->namelabs)) + return r; /* need to prime this stub */ + return NULL; +} + +int hints_next_root(struct iter_hints* hints, uint16_t* qclass) +{ + return name_tree_next_root(&hints->tree, qclass); +} + +size_t +hints_get_mem(struct iter_hints* hints) +{ + size_t s; + struct iter_hints_stub* p; + if(!hints) return 0; + s = sizeof(*hints); + RBTREE_FOR(p, struct iter_hints_stub*, &hints->tree) { + s += sizeof(*p) + delegpt_get_mem(p->dp); + } + return s; +} + +int +hints_add_stub(struct iter_hints* hints, uint16_t c, struct delegpt* dp, + int noprime) +{ + struct iter_hints_stub *z; + if((z=(struct iter_hints_stub*)name_tree_find(&hints->tree, + dp->name, dp->namelen, dp->namelabs, c)) != NULL) { + (void)rbtree_delete(&hints->tree, &z->node); + hints_stub_free(z); + } + if(!hints_insert(hints, c, dp, noprime)) + return 0; + name_tree_init_parents(&hints->tree); + return 1; +} + +void +hints_delete_stub(struct iter_hints* hints, uint16_t c, uint8_t* nm) +{ + struct iter_hints_stub *z; + size_t len; + int labs = dname_count_size_labels(nm, &len); + if(!(z=(struct iter_hints_stub*)name_tree_find(&hints->tree, + nm, len, labs, c))) + return; /* nothing to do */ + (void)rbtree_delete(&hints->tree, &z->node); + hints_stub_free(z); + name_tree_init_parents(&hints->tree); +} + diff --git a/external/unbound/iterator/iter_hints.h b/external/unbound/iterator/iter_hints.h new file mode 100644 index 000000000..715ec9f41 --- /dev/null +++ b/external/unbound/iterator/iter_hints.h @@ -0,0 +1,161 @@ +/* + * iterator/iter_hints.h - iterative resolver module stub and root hints. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file contains functions to assist the iterator module. + * Keep track of stub and root hints, and read those from config. + */ + +#ifndef ITERATOR_ITER_HINTS_H +#define ITERATOR_ITER_HINTS_H +#include "util/storage/dnstree.h" +struct iter_env; +struct config_file; +struct delegpt; + +/** + * Iterator hints structure + */ +struct iter_hints { + /** + * Hints are stored in this tree. Sort order is specially chosen. + * first sorted on qclass. Then on dname in nsec-like order, so that + * a lookup on class, name will return an exact match or the closest + * match which gives the ancestor needed. + * contents of type iter_hints_stub. The class IN root is in here. + * uses name_tree_node from dnstree.h. + */ + rbtree_t tree; +}; + +/** + * Iterator hints for a particular stub. + */ +struct iter_hints_stub { + /** tree sorted by name, class */ + struct name_tree_node node; + /** delegation point with hint information for this stub. malloced. */ + struct delegpt* dp; + /** does the stub need to forego priming (like on other ports) */ + uint8_t noprime; +}; + +/** + * Create hints + * @return new hints or NULL on error. + */ +struct iter_hints* hints_create(void); + +/** + * Delete hints. + * @param hints: to delete. + */ +void hints_delete(struct iter_hints* hints); + +/** + * Process hints config. Sets default values for root hints if no config. + * @param hints: where to store. + * @param cfg: config options. + * @return 0 on error. + */ +int hints_apply_cfg(struct iter_hints* hints, struct config_file* cfg); + +/** + * Find root hints for the given class. + * @param hints: hint storage. + * @param qclass: class for which root hints are requested. host order. + * @return: NULL if no hints, or a ptr to stored hints. + */ +struct delegpt* hints_lookup_root(struct iter_hints* hints, uint16_t qclass); + +/** + * Find next root hints (to cycle through all root hints). + * @param hints: hint storage + * @param qclass: class for which root hints are sought. + * 0 means give the first available root hints class. + * x means, give class x or a higher class if any. + * returns the found class in this variable. + * @return true if a root hint class is found. + * false if not root hint class is found (qclass may have been changed). + */ +int hints_next_root(struct iter_hints* hints, uint16_t* qclass); + +/** + * Given a qname/qclass combination, and the delegation point from the cache + * for this qname/qclass, determine if this combination indicates that a + * stub hint exists and must be primed. + * + * @param hints: hint storage. + * @param qname: The qname that generated the delegation point. + * @param qclass: The qclass that generated the delegation point. + * @param dp: The cache generated delegation point. + * @return: A priming delegation point if there is a stub hint that must + * be primed, otherwise null. + */ +struct iter_hints_stub* hints_lookup_stub(struct iter_hints* hints, + uint8_t* qname, uint16_t qclass, struct delegpt* dp); + +/** + * Get memory in use by hints + * @param hints: hint storage. + * @return bytes in use + */ +size_t hints_get_mem(struct iter_hints* hints); + +/** + * Add stub to hints structure. For external use since it recalcs + * the tree parents. + * @param hints: the hints data structure + * @param c: class of zone + * @param dp: delegation point with name and target nameservers for new + * hints stub. malloced. + * @param noprime: set noprime option to true or false on new hint stub. + * @return false on failure (out of memory); + */ +int hints_add_stub(struct iter_hints* hints, uint16_t c, struct delegpt* dp, + int noprime); + +/** + * Remove stub from hints structure. For external use since it + * recalcs the tree parents. + * @param hints: the hints data structure + * @param c: class of stub zone + * @param nm: name of stub zone (in uncompressed wireformat). + */ +void hints_delete_stub(struct iter_hints* hints, uint16_t c, uint8_t* nm); + +#endif /* ITERATOR_ITER_HINTS_H */ diff --git a/external/unbound/iterator/iter_priv.c b/external/unbound/iterator/iter_priv.c new file mode 100644 index 000000000..9e09a84bd --- /dev/null +++ b/external/unbound/iterator/iter_priv.c @@ -0,0 +1,296 @@ +/* + * iterator/iter_priv.c - iterative resolver private address and domain store + * + * Copyright (c) 2008, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file contains functions to assist the iterator module. + * Keep track of the private addresses and lookup fast. + */ + +#include "config.h" +#include "iterator/iter_priv.h" +#include "util/regional.h" +#include "util/log.h" +#include "util/config_file.h" +#include "util/data/dname.h" +#include "util/data/msgparse.h" +#include "util/net_help.h" +#include "util/storage/dnstree.h" +#include "ldns/str2wire.h" +#include "ldns/sbuffer.h" + +struct iter_priv* priv_create(void) +{ + struct iter_priv* priv = (struct iter_priv*)calloc(1, sizeof(*priv)); + if(!priv) + return NULL; + priv->region = regional_create(); + if(!priv->region) { + priv_delete(priv); + return NULL; + } + addr_tree_init(&priv->a); + name_tree_init(&priv->n); + return priv; +} + +void priv_delete(struct iter_priv* priv) +{ + if(!priv) return; + regional_destroy(priv->region); + free(priv); +} + +/** Read private-addr declarations from config */ +static int read_addrs(struct iter_priv* priv, struct config_file* cfg) +{ + /* parse addresses, report errors, insert into tree */ + struct config_strlist* p; + struct addr_tree_node* n; + struct sockaddr_storage addr; + int net; + socklen_t addrlen; + + for(p = cfg->private_address; p; p = p->next) { + log_assert(p->str); + if(!netblockstrtoaddr(p->str, UNBOUND_DNS_PORT, &addr, + &addrlen, &net)) { + log_err("cannot parse private-address: %s", p->str); + return 0; + } + n = (struct addr_tree_node*)regional_alloc(priv->region, + sizeof(*n)); + if(!n) { + log_err("out of memory"); + return 0; + } + if(!addr_tree_insert(&priv->a, n, &addr, addrlen, net)) { + verbose(VERB_QUERY, "ignoring duplicate " + "private-address: %s", p->str); + } + } + return 1; +} + +/** Read private-domain declarations from config */ +static int read_names(struct iter_priv* priv, struct config_file* cfg) +{ + /* parse names, report errors, insert into tree */ + struct config_strlist* p; + struct name_tree_node* n; + uint8_t* nm, *nmr; + size_t nm_len; + int nm_labs; + + for(p = cfg->private_domain; p; p = p->next) { + log_assert(p->str); + nm = sldns_str2wire_dname(p->str, &nm_len); + if(!nm) { + log_err("cannot parse private-domain: %s", p->str); + return 0; + } + nm_labs = dname_count_size_labels(nm, &nm_len); + nmr = (uint8_t*)regional_alloc_init(priv->region, nm, nm_len); + free(nm); + if(!nmr) { + log_err("out of memory"); + return 0; + } + n = (struct name_tree_node*)regional_alloc(priv->region, + sizeof(*n)); + if(!n) { + log_err("out of memory"); + return 0; + } + if(!name_tree_insert(&priv->n, n, nmr, nm_len, nm_labs, + LDNS_RR_CLASS_IN)) { + verbose(VERB_QUERY, "ignoring duplicate " + "private-domain: %s", p->str); + } + } + return 1; +} + +int priv_apply_cfg(struct iter_priv* priv, struct config_file* cfg) +{ + /* empty the current contents */ + regional_free_all(priv->region); + addr_tree_init(&priv->a); + name_tree_init(&priv->n); + + /* read new contents */ + if(!read_addrs(priv, cfg)) + return 0; + if(!read_names(priv, cfg)) + return 0; + + /* prepare for lookups */ + addr_tree_init_parents(&priv->a); + name_tree_init_parents(&priv->n); + return 1; +} + +/** + * See if an address is blocked. + * @param priv: structure for address storage. + * @param addr: address to check + * @param addrlen: length of addr. + * @return: true if the address must not be queried. false if unlisted. + */ +static int +priv_lookup_addr(struct iter_priv* priv, struct sockaddr_storage* addr, + socklen_t addrlen) +{ + return addr_tree_lookup(&priv->a, addr, addrlen) != NULL; +} + +/** + * See if a name is whitelisted. + * @param priv: structure for address storage. + * @param pkt: the packet (for compression ptrs). + * @param name: name to check. + * @param name_len: uncompressed length of the name to check. + * @param dclass: class to check. + * @return: true if the name is OK. false if unlisted. + */ +static int +priv_lookup_name(struct iter_priv* priv, sldns_buffer* pkt, + uint8_t* name, size_t name_len, uint16_t dclass) +{ + size_t len; + uint8_t decomp[256]; + int labs; + if(name_len >= sizeof(decomp)) + return 0; + dname_pkt_copy(pkt, decomp, name); + labs = dname_count_size_labels(decomp, &len); + log_assert(name_len == len); + return name_tree_lookup(&priv->n, decomp, len, labs, dclass) != NULL; +} + +size_t priv_get_mem(struct iter_priv* priv) +{ + if(!priv) return 0; + return sizeof(*priv) + regional_get_mem(priv->region); +} + +/** remove RR from msgparse RRset, return true if rrset is entirely bad */ +static int +remove_rr(const char* str, sldns_buffer* pkt, struct rrset_parse* rrset, + struct rr_parse* prev, struct rr_parse** rr, struct sockaddr_storage* addr, socklen_t addrlen) +{ + if(verbosity >= VERB_QUERY && rrset->dname_len <= LDNS_MAX_DOMAINLEN && str) { + uint8_t buf[LDNS_MAX_DOMAINLEN+1]; + dname_pkt_copy(pkt, buf, rrset->dname); + log_name_addr(VERB_QUERY, str, buf, addr, addrlen); + } + if(prev) + prev->next = (*rr)->next; + else rrset->rr_first = (*rr)->next; + if(rrset->rr_last == *rr) + rrset->rr_last = prev; + rrset->rr_count --; + rrset->size -= (*rr)->size; + /* rr struct still exists, but is unlinked, so that in the for loop + * the rr->next works fine to continue. */ + return rrset->rr_count == 0; +} + +int priv_rrset_bad(struct iter_priv* priv, sldns_buffer* pkt, + struct rrset_parse* rrset) +{ + if(priv->a.count == 0) + return 0; /* there are no blocked addresses */ + + /* see if it is a private name, that is allowed to have any */ + if(priv_lookup_name(priv, pkt, rrset->dname, rrset->dname_len, + ntohs(rrset->rrset_class))) { + return 0; + } else { + /* so its a public name, check the address */ + socklen_t len; + struct rr_parse* rr, *prev = NULL; + if(rrset->type == LDNS_RR_TYPE_A) { + struct sockaddr_storage addr; + struct sockaddr_in sa; + + len = (socklen_t)sizeof(sa); + memset(&sa, 0, len); + sa.sin_family = AF_INET; + sa.sin_port = (in_port_t)htons(UNBOUND_DNS_PORT); + for(rr = rrset->rr_first; rr; rr = rr->next) { + if(sldns_read_uint16(rr->ttl_data+4) + != INET_SIZE) { + prev = rr; + continue; + } + memmove(&sa.sin_addr, rr->ttl_data+4+2, + INET_SIZE); + memmove(&addr, &sa, len); + if(priv_lookup_addr(priv, &addr, len)) { + if(remove_rr("sanitize: removing public name with private address", pkt, rrset, prev, &rr, &addr, len)) + return 1; + continue; + } + prev = rr; + } + } else if(rrset->type == LDNS_RR_TYPE_AAAA) { + struct sockaddr_storage addr; + struct sockaddr_in6 sa; + len = (socklen_t)sizeof(sa); + memset(&sa, 0, len); + sa.sin6_family = AF_INET6; + sa.sin6_port = (in_port_t)htons(UNBOUND_DNS_PORT); + for(rr = rrset->rr_first; rr; rr = rr->next) { + if(sldns_read_uint16(rr->ttl_data+4) + != INET6_SIZE) { + prev = rr; + continue; + } + memmove(&sa.sin6_addr, rr->ttl_data+4+2, + INET6_SIZE); + memmove(&addr, &sa, len); + if(priv_lookup_addr(priv, &addr, len)) { + if(remove_rr("sanitize: removing public name with private address", pkt, rrset, prev, &rr, &addr, len)) + return 1; + continue; + } + prev = rr; + } + } + } + return 0; +} diff --git a/external/unbound/iterator/iter_priv.h b/external/unbound/iterator/iter_priv.h new file mode 100644 index 000000000..6fa84900b --- /dev/null +++ b/external/unbound/iterator/iter_priv.h @@ -0,0 +1,112 @@ +/* + * iterator/iter_priv.h - iterative resolver private address and domain store + * + * Copyright (c) 2008, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file contains functions to assist the iterator module. + * Keep track of the private addresses and lookup fast. + */ + +#ifndef ITERATOR_ITER_PRIV_H +#define ITERATOR_ITER_PRIV_H +#include "util/rbtree.h" +struct sldns_buffer; +struct iter_env; +struct config_file; +struct regional; +struct rrset_parse; + +/** + * Iterator priv structure + */ +struct iter_priv { + /** regional for allocation */ + struct regional* region; + /** + * Tree of the address spans that are blocked. + * contents of type addr_tree_node. + * No further data need, only presence or absence. + */ + rbtree_t a; + /** + * Tree of the domains spans that are allowed to contain + * the blocked address spans. + * contents of type name_tree_node. + * No further data need, only presence or absence. + */ + rbtree_t n; +}; + +/** + * Create priv structure + * @return new structure or NULL on error. + */ +struct iter_priv* priv_create(void); + +/** + * Delete priv structure. + * @param priv: to delete. + */ +void priv_delete(struct iter_priv* priv); + +/** + * Process priv config. + * @param priv: where to store. + * @param cfg: config options. + * @return 0 on error. + */ +int priv_apply_cfg(struct iter_priv* priv, struct config_file* cfg); + +/** + * See if rrset is bad. + * Will remove individual RRs that are bad (if possible) to + * sanitize the RRset without removing it completely. + * @param priv: structure for private address storage. + * @param pkt: packet to decompress rrset name in. + * @param rrset: the rrset to examine, A or AAAA. + * @return true if the rrset is bad and should be removed. + */ +int priv_rrset_bad(struct iter_priv* priv, struct sldns_buffer* pkt, + struct rrset_parse* rrset); + +/** + * Get memory used by priv structure. + * @param priv: structure for address storage. + * @return bytes in use. + */ +size_t priv_get_mem(struct iter_priv* priv); + +#endif /* ITERATOR_ITER_PRIV_H */ diff --git a/external/unbound/iterator/iter_resptype.c b/external/unbound/iterator/iter_resptype.c new file mode 100644 index 000000000..45f919387 --- /dev/null +++ b/external/unbound/iterator/iter_resptype.c @@ -0,0 +1,287 @@ +/* + * iterator/iter_resptype.c - response type information and classification. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file defines the response type. DNS Responses can be classified as + * one of the response types. + */ +#include "config.h" +#include "iterator/iter_resptype.h" +#include "iterator/iter_delegpt.h" +#include "services/cache/dns.h" +#include "util/net_help.h" +#include "util/data/dname.h" +#include "ldns/rrdef.h" +#include "ldns/pkthdr.h" + +enum response_type +response_type_from_cache(struct dns_msg* msg, + struct query_info* request) +{ + /* If the message is NXDOMAIN, then it is an ANSWER. */ + if(FLAGS_GET_RCODE(msg->rep->flags) == LDNS_RCODE_NXDOMAIN) + return RESPONSE_TYPE_ANSWER; + if(request->qtype == LDNS_RR_TYPE_ANY) + return RESPONSE_TYPE_ANSWER; + + /* First we look at the answer section. This can tell us if this is + * CNAME or positive ANSWER. */ + if(msg->rep->an_numrrsets > 0) { + /* Now look at the answer section first. 3 states: + * o our answer is there directly, + * o our answer is there after a cname, + * o or there is just a cname. */ + uint8_t* mname = request->qname; + size_t mname_len = request->qname_len; + size_t i; + for(i=0; i<msg->rep->an_numrrsets; i++) { + struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; + + /* If we have encountered an answer (before or + * after a CNAME), then we are done! Note that + * if qtype == CNAME then this will be noted as + * an ANSWER before it gets treated as a CNAME, + * as it should */ + if(ntohs(s->rk.type) == request->qtype && + ntohs(s->rk.rrset_class) == request->qclass && + query_dname_compare(mname, s->rk.dname) == 0) { + return RESPONSE_TYPE_ANSWER; + } + + /* If we have encountered a CNAME, make sure that + * it is relevant. */ + if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME && + query_dname_compare(mname, s->rk.dname) == 0) { + get_cname_target(s, &mname, &mname_len); + } + } + + /* if we encountered a CNAME (or a bunch of CNAMEs), and + * still got to here, then it is a CNAME response. (i.e., + * the CNAME chain didn't terminate in an answer rrset.) */ + if(mname != request->qname) { + return RESPONSE_TYPE_CNAME; + } + } + + /* At this point, since we don't need to detect REFERRAL or LAME + * messages, it can only be an ANSWER. */ + return RESPONSE_TYPE_ANSWER; +} + +enum response_type +response_type_from_server(int rdset, + struct dns_msg* msg, struct query_info* request, struct delegpt* dp) +{ + uint8_t* origzone = (uint8_t*)"\000"; /* the default */ + struct ub_packed_rrset_key* s; + size_t i; + + if(!msg || !request) + return RESPONSE_TYPE_THROWAWAY; + + /* If the message is NXDOMAIN, then it answers the question. */ + if(FLAGS_GET_RCODE(msg->rep->flags) == LDNS_RCODE_NXDOMAIN) { + /* make sure its not recursive when we don't want it to */ + if( (msg->rep->flags&BIT_RA) && + !(msg->rep->flags&BIT_AA) && !rdset) + return RESPONSE_TYPE_REC_LAME; + /* it could be a CNAME with NXDOMAIN rcode */ + for(i=0; i<msg->rep->an_numrrsets; i++) { + s = msg->rep->rrsets[i]; + if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME && + query_dname_compare(request->qname, + s->rk.dname) == 0) { + return RESPONSE_TYPE_CNAME; + } + } + return RESPONSE_TYPE_ANSWER; + } + + /* Other response codes mean (so far) to throw the response away as + * meaningless and move on to the next nameserver. */ + if(FLAGS_GET_RCODE(msg->rep->flags) != LDNS_RCODE_NOERROR) + return RESPONSE_TYPE_THROWAWAY; + + /* Note: TC bit has already been handled */ + + if(dp) { + origzone = dp->name; + } + + /* First we look at the answer section. This can tell us if this is a + * CNAME or ANSWER or (provisional) ANSWER. */ + if(msg->rep->an_numrrsets > 0) { + uint8_t* mname = request->qname; + size_t mname_len = request->qname_len; + + /* Now look at the answer section first. 3 states: our + * answer is there directly, our answer is there after + * a cname, or there is just a cname. */ + for(i=0; i<msg->rep->an_numrrsets; i++) { + s = msg->rep->rrsets[i]; + + /* if the answer section has NS rrset, and qtype ANY + * and the delegation is lower, and no CNAMEs followed, + * this is a referral where the NS went to AN section */ + if((request->qtype == LDNS_RR_TYPE_ANY || + request->qtype == LDNS_RR_TYPE_NS) && + ntohs(s->rk.type) == LDNS_RR_TYPE_NS && + ntohs(s->rk.rrset_class) == request->qclass && + dname_strict_subdomain_c(s->rk.dname, + origzone)) { + if((msg->rep->flags&BIT_AA)) + return RESPONSE_TYPE_ANSWER; + return RESPONSE_TYPE_REFERRAL; + } + + /* If we have encountered an answer (before or + * after a CNAME), then we are done! Note that + * if qtype == CNAME then this will be noted as an + * ANSWER before it gets treated as a CNAME, as + * it should. */ + if(ntohs(s->rk.type) == request->qtype && + ntohs(s->rk.rrset_class) == request->qclass && + query_dname_compare(mname, s->rk.dname) == 0) { + if((msg->rep->flags&BIT_AA)) + return RESPONSE_TYPE_ANSWER; + /* If the AA bit isn't on, and we've seen + * the answer, we only provisionally say + * 'ANSWER' -- it very well could be a + * REFERRAL. */ + break; + } + + /* If we have encountered a CNAME, make sure that + * it is relevant. */ + if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME && + query_dname_compare(mname, s->rk.dname) == 0) { + get_cname_target(s, &mname, &mname_len); + } + } + /* not a referral, and qtype any, thus an answer */ + if(request->qtype == LDNS_RR_TYPE_ANY) + return RESPONSE_TYPE_ANSWER; + /* if we encountered a CNAME (or a bunch of CNAMEs), and + * still got to here, then it is a CNAME response. + * (This is regardless of the AA bit at this point) */ + if(mname != request->qname) { + return RESPONSE_TYPE_CNAME; + } + } + + /* Looking at the authority section, we just look and see if + * there is a SOA record, that means a NOERROR/NODATA */ + for(i = msg->rep->an_numrrsets; i < (msg->rep->an_numrrsets + + msg->rep->ns_numrrsets); i++) { + s = msg->rep->rrsets[i]; + + /* The normal way of detecting NOERROR/NODATA. */ + if(ntohs(s->rk.type) == LDNS_RR_TYPE_SOA && + dname_subdomain_c(request->qname, s->rk.dname)) { + /* we do our own recursion, thank you */ + if( (msg->rep->flags&BIT_RA) && + !(msg->rep->flags&BIT_AA) && !rdset) + return RESPONSE_TYPE_REC_LAME; + return RESPONSE_TYPE_ANSWER; + } + } + /* Looking at the authority section, we just look and see if + * there is a delegation NS set, turning it into a delegation. + * Otherwise, we will have to conclude ANSWER (either it is + * NOERROR/NODATA, or an non-authoritative answer). */ + for(i = msg->rep->an_numrrsets; i < (msg->rep->an_numrrsets + + msg->rep->ns_numrrsets); i++) { + s = msg->rep->rrsets[i]; + + /* Detect REFERRAL/LAME/ANSWER based on the relationship + * of the NS set to the originating zone name. */ + if(ntohs(s->rk.type) == LDNS_RR_TYPE_NS) { + /* If we are getting an NS set for the zone we + * thought we were contacting, then it is an answer.*/ + if(query_dname_compare(s->rk.dname, origzone) == 0) { + /* see if mistakenly a recursive server was + * deployed and is responding nonAA */ + if( (msg->rep->flags&BIT_RA) && + !(msg->rep->flags&BIT_AA) && !rdset) + return RESPONSE_TYPE_REC_LAME; + /* Or if a lame server is deployed, + * which gives ns==zone delegation from cache + * without AA bit as well, with nodata nosoa*/ + /* real answer must be +AA and SOA RFC(2308), + * so this is wrong, and we SERVFAIL it if + * this is the only possible reply, if it + * is misdeployed the THROWAWAY makes us pick + * the next server from the selection */ + if(msg->rep->an_numrrsets==0 && + !(msg->rep->flags&BIT_AA) && !rdset) + return RESPONSE_TYPE_THROWAWAY; + return RESPONSE_TYPE_ANSWER; + } + /* If we are getting a referral upwards (or to + * the same zone), then the server is 'lame'. */ + if(dname_subdomain_c(origzone, s->rk.dname)) { + if(rdset) /* forward or reclame not LAME */ + return RESPONSE_TYPE_THROWAWAY; + return RESPONSE_TYPE_LAME; + } + /* If the NS set is below the delegation point we + * are on, and it is non-authoritative, then it is + * a referral, otherwise it is an answer. */ + if(dname_subdomain_c(s->rk.dname, origzone)) { + /* NOTE: I no longer remember in what case + * we would like this to be an answer. + * NODATA should have a SOA or nothing, + * not an NS rrset. + * True, referrals should not have the AA + * bit set, but... */ + + /* if((msg->rep->flags&BIT_AA)) + return RESPONSE_TYPE_ANSWER; */ + return RESPONSE_TYPE_REFERRAL; + } + /* Otherwise, the NS set is irrelevant. */ + } + } + + /* If we've gotten this far, this is NOERROR/NODATA (which could + * be an entirely empty message) */ + /* check if recursive answer; saying it has empty cache */ + if( (msg->rep->flags&BIT_RA) && !(msg->rep->flags&BIT_AA) && !rdset) + return RESPONSE_TYPE_REC_LAME; + return RESPONSE_TYPE_ANSWER; +} diff --git a/external/unbound/iterator/iter_resptype.h b/external/unbound/iterator/iter_resptype.h new file mode 100644 index 000000000..fee9ef35f --- /dev/null +++ b/external/unbound/iterator/iter_resptype.h @@ -0,0 +1,127 @@ +/* + * iterator/iter_resptype.h - response type information and classification. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file defines the response type. DNS Responses can be classified as + * one of the response types. + */ + +#ifndef ITERATOR_ITER_RESPTYPE_H +#define ITERATOR_ITER_RESPTYPE_H +struct dns_msg; +struct query_info; +struct delegpt; + +/** + * The response type is used to interpret the response. + */ +enum response_type { + /** + * 'untyped' means that the type of this response hasn't been + * assigned. + */ + RESPONSE_TYPE_UNTYPED = 0, + + /** + * 'answer' means that the response terminates the resolution + * process. + */ + RESPONSE_TYPE_ANSWER, + + /** 'delegation' means that the response is a delegation. */ + RESPONSE_TYPE_REFERRAL, + + /** + * 'cname' means that the response is a cname without the final + * answer, and thus must be restarted. + */ + RESPONSE_TYPE_CNAME, + + /** + * 'throwaway' means that this particular response should be + * discarded and the next nameserver should be contacted + */ + RESPONSE_TYPE_THROWAWAY, + + /** + * 'lame' means that this particular response indicates that + * the nameserver knew nothing about the question. + */ + RESPONSE_TYPE_LAME, + + /** + * Recursion lame means that the nameserver is some sort of + * open recursor, and not authoritative for the question. + * It may know something, but not authoritatively. + */ + RESPONSE_TYPE_REC_LAME +}; + +/** + * Classifies a response message from cache based on the current request. + * Note that this routine assumes that THROWAWAY or LAME responses will not + * occur. Also, it will not detect REFERRAL type messages, since those are + * (currently) automatically classified based on how they came from the + * cache (findDelegation() instead of lookup()). + * + * @param msg: the message from the cache. + * @param request: the request that generated the response. + * @return the response type (CNAME or ANSWER). + */ +enum response_type response_type_from_cache(struct dns_msg* msg, + struct query_info* request); + +/** + * Classifies a response message (from the wire) based on the current + * request. + * + * NOTE: currently this routine uses the AA bit in the response to help + * distinguish between some non-standard referrals and answers. It also + * relies somewhat on the originating zone to be accurate (for lameness + * detection, mostly). + * + * @param rdset: if RD bit was sent in query sent by unbound. + * @param msg: the message from the cache. + * @param request: the request that generated the response. + * @param dp: The delegation point that was being queried + * when the response was returned. + * @return the response type (CNAME or ANSWER). + */ +enum response_type response_type_from_server(int rdset, + struct dns_msg* msg, struct query_info* request, struct delegpt* dp); + +#endif /* ITERATOR_ITER_RESPTYPE_H */ diff --git a/external/unbound/iterator/iter_scrub.c b/external/unbound/iterator/iter_scrub.c new file mode 100644 index 000000000..b2248bc0c --- /dev/null +++ b/external/unbound/iterator/iter_scrub.c @@ -0,0 +1,754 @@ +/* + * iterator/iter_scrub.c - scrubbing, normalization, sanitization of DNS msgs. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file has routine(s) for cleaning up incoming DNS messages from + * possible useless or malicious junk in it. + */ +#include "config.h" +#include "iterator/iter_scrub.h" +#include "iterator/iterator.h" +#include "iterator/iter_priv.h" +#include "services/cache/rrset.h" +#include "util/log.h" +#include "util/net_help.h" +#include "util/regional.h" +#include "util/config_file.h" +#include "util/module.h" +#include "util/data/msgparse.h" +#include "util/data/dname.h" +#include "util/data/msgreply.h" +#include "util/alloc.h" +#include "ldns/sbuffer.h" + +/** RRset flag used during scrubbing. The RRset is OK. */ +#define RRSET_SCRUB_OK 0x80 + +/** remove rrset, update loop variables */ +static void +remove_rrset(const char* str, sldns_buffer* pkt, struct msg_parse* msg, + struct rrset_parse* prev, struct rrset_parse** rrset) +{ + if(verbosity >= VERB_QUERY && str + && (*rrset)->dname_len <= LDNS_MAX_DOMAINLEN) { + uint8_t buf[LDNS_MAX_DOMAINLEN+1]; + dname_pkt_copy(pkt, buf, (*rrset)->dname); + log_nametypeclass(VERB_QUERY, str, buf, + (*rrset)->type, ntohs((*rrset)->rrset_class)); + } + if(prev) + prev->rrset_all_next = (*rrset)->rrset_all_next; + else msg->rrset_first = (*rrset)->rrset_all_next; + if(msg->rrset_last == *rrset) + msg->rrset_last = prev; + msg->rrset_count --; + switch((*rrset)->section) { + case LDNS_SECTION_ANSWER: msg->an_rrsets--; break; + case LDNS_SECTION_AUTHORITY: msg->ns_rrsets--; break; + case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets--; break; + default: log_assert(0); + } + msgparse_bucket_remove(msg, *rrset); + *rrset = (*rrset)->rrset_all_next; +} + +/** return true if rr type has additional names in it */ +static int +has_additional(uint16_t t) +{ + switch(t) { + case LDNS_RR_TYPE_MB: + case LDNS_RR_TYPE_MD: + case LDNS_RR_TYPE_MF: + case LDNS_RR_TYPE_NS: + case LDNS_RR_TYPE_MX: + case LDNS_RR_TYPE_KX: + case LDNS_RR_TYPE_SRV: + return 1; + case LDNS_RR_TYPE_NAPTR: + /* TODO: NAPTR not supported, glue stripped off */ + return 0; + } + return 0; +} + +/** get additional name from rrset RR, return false if no name present */ +static int +get_additional_name(struct rrset_parse* rrset, struct rr_parse* rr, + uint8_t** nm, size_t* nmlen, sldns_buffer* pkt) +{ + size_t offset = 0; + size_t len, oldpos; + switch(rrset->type) { + case LDNS_RR_TYPE_MB: + case LDNS_RR_TYPE_MD: + case LDNS_RR_TYPE_MF: + case LDNS_RR_TYPE_NS: + offset = 0; + break; + case LDNS_RR_TYPE_MX: + case LDNS_RR_TYPE_KX: + offset = 2; + break; + case LDNS_RR_TYPE_SRV: + offset = 6; + break; + case LDNS_RR_TYPE_NAPTR: + /* TODO: NAPTR not supported, glue stripped off */ + return 0; + default: + return 0; + } + len = sldns_read_uint16(rr->ttl_data+sizeof(uint32_t)); + if(len < offset+1) + return 0; /* rdata field too small */ + *nm = rr->ttl_data+sizeof(uint32_t)+sizeof(uint16_t)+offset; + oldpos = sldns_buffer_position(pkt); + sldns_buffer_set_position(pkt, (size_t)(*nm - sldns_buffer_begin(pkt))); + *nmlen = pkt_dname_len(pkt); + sldns_buffer_set_position(pkt, oldpos); + if(*nmlen == 0) + return 0; + return 1; +} + +/** Place mark on rrsets in additional section they are OK */ +static void +mark_additional_rrset(sldns_buffer* pkt, struct msg_parse* msg, + struct rrset_parse* rrset) +{ + /* Mark A and AAAA for NS as appropriate additional section info. */ + uint8_t* nm = NULL; + size_t nmlen = 0; + struct rr_parse* rr; + + if(!has_additional(rrset->type)) + return; + for(rr = rrset->rr_first; rr; rr = rr->next) { + if(get_additional_name(rrset, rr, &nm, &nmlen, pkt)) { + /* mark A */ + hashvalue_t h = pkt_hash_rrset(pkt, nm, LDNS_RR_TYPE_A, + rrset->rrset_class, 0); + struct rrset_parse* r = msgparse_hashtable_lookup( + msg, pkt, h, 0, nm, nmlen, + LDNS_RR_TYPE_A, rrset->rrset_class); + if(r && r->section == LDNS_SECTION_ADDITIONAL) { + r->flags |= RRSET_SCRUB_OK; + } + + /* mark AAAA */ + h = pkt_hash_rrset(pkt, nm, LDNS_RR_TYPE_AAAA, + rrset->rrset_class, 0); + r = msgparse_hashtable_lookup(msg, pkt, h, 0, nm, + nmlen, LDNS_RR_TYPE_AAAA, rrset->rrset_class); + if(r && r->section == LDNS_SECTION_ADDITIONAL) { + r->flags |= RRSET_SCRUB_OK; + } + } + } +} + +/** Get target name of a CNAME */ +static int +parse_get_cname_target(struct rrset_parse* rrset, uint8_t** sname, + size_t* snamelen) +{ + if(rrset->rr_count != 1) { + struct rr_parse* sig; + verbose(VERB_ALGO, "Found CNAME rrset with " + "size > 1: %u", (unsigned)rrset->rr_count); + /* use the first CNAME! */ + rrset->rr_count = 1; + rrset->size = rrset->rr_first->size; + for(sig=rrset->rrsig_first; sig; sig=sig->next) + rrset->size += sig->size; + rrset->rr_last = rrset->rr_first; + rrset->rr_first->next = NULL; + } + if(rrset->rr_first->size < sizeof(uint16_t)+1) + return 0; /* CNAME rdata too small */ + *sname = rrset->rr_first->ttl_data + sizeof(uint32_t) + + sizeof(uint16_t); /* skip ttl, rdatalen */ + *snamelen = rrset->rr_first->size - sizeof(uint16_t); + return 1; +} + +/** Synthesize CNAME from DNAME, false if too long */ +static int +synth_cname(uint8_t* qname, size_t qnamelen, struct rrset_parse* dname_rrset, + uint8_t* alias, size_t* aliaslen, sldns_buffer* pkt) +{ + /* we already know that sname is a strict subdomain of DNAME owner */ + uint8_t* dtarg = NULL; + size_t dtarglen; + if(!parse_get_cname_target(dname_rrset, &dtarg, &dtarglen)) + return 0; + log_assert(qnamelen > dname_rrset->dname_len); + /* DNAME from com. to net. with qname example.com. -> example.net. */ + /* so: \3com\0 to \3net\0 and qname \7example\3com\0 */ + *aliaslen = qnamelen + dtarglen - dname_rrset->dname_len; + if(*aliaslen > LDNS_MAX_DOMAINLEN) + return 0; /* should have been RCODE YXDOMAIN */ + /* decompress dnames into buffer, we know it fits */ + dname_pkt_copy(pkt, alias, qname); + dname_pkt_copy(pkt, alias+(qnamelen-dname_rrset->dname_len), dtarg); + return 1; +} + +/** synthesize a CNAME rrset */ +static struct rrset_parse* +synth_cname_rrset(uint8_t** sname, size_t* snamelen, uint8_t* alias, + size_t aliaslen, struct regional* region, struct msg_parse* msg, + struct rrset_parse* rrset, struct rrset_parse* prev, + struct rrset_parse* nx, sldns_buffer* pkt) +{ + struct rrset_parse* cn = (struct rrset_parse*)regional_alloc(region, + sizeof(struct rrset_parse)); + if(!cn) + return NULL; + memset(cn, 0, sizeof(*cn)); + cn->rr_first = (struct rr_parse*)regional_alloc(region, + sizeof(struct rr_parse)); + if(!cn->rr_first) + return NULL; + cn->rr_last = cn->rr_first; + /* CNAME from sname to alias */ + cn->dname = (uint8_t*)regional_alloc(region, *snamelen); + if(!cn->dname) + return NULL; + dname_pkt_copy(pkt, cn->dname, *sname); + cn->dname_len = *snamelen; + cn->type = LDNS_RR_TYPE_CNAME; + cn->section = rrset->section; + cn->rrset_class = rrset->rrset_class; + cn->rr_count = 1; + cn->size = sizeof(uint16_t) + aliaslen; + cn->hash=pkt_hash_rrset(pkt, cn->dname, cn->type, cn->rrset_class, 0); + /* allocate TTL + rdatalen + uncompressed dname */ + memset(cn->rr_first, 0, sizeof(struct rr_parse)); + cn->rr_first->outside_packet = 1; + cn->rr_first->ttl_data = (uint8_t*)regional_alloc(region, + sizeof(uint32_t)+sizeof(uint16_t)+aliaslen); + if(!cn->rr_first->ttl_data) + return NULL; + sldns_write_uint32(cn->rr_first->ttl_data, 0); /* TTL = 0 */ + sldns_write_uint16(cn->rr_first->ttl_data+4, aliaslen); + memmove(cn->rr_first->ttl_data+6, alias, aliaslen); + cn->rr_first->size = sizeof(uint16_t)+aliaslen; + + /* link it in */ + cn->rrset_all_next = nx; + if(prev) + prev->rrset_all_next = cn; + else msg->rrset_first = cn; + if(nx == NULL) + msg->rrset_last = cn; + msg->rrset_count ++; + msg->an_rrsets++; + /* it is not inserted in the msg hashtable. */ + + *sname = cn->rr_first->ttl_data + sizeof(uint32_t)+sizeof(uint16_t); + *snamelen = aliaslen; + return cn; +} + +/** check if DNAME applies to a name */ +static int +pkt_strict_sub(sldns_buffer* pkt, uint8_t* sname, uint8_t* dr) +{ + uint8_t buf1[LDNS_MAX_DOMAINLEN+1]; + uint8_t buf2[LDNS_MAX_DOMAINLEN+1]; + /* decompress names */ + dname_pkt_copy(pkt, buf1, sname); + dname_pkt_copy(pkt, buf2, dr); + return dname_strict_subdomain_c(buf1, buf2); +} + +/** check subdomain with decompression */ +static int +pkt_sub(sldns_buffer* pkt, uint8_t* comprname, uint8_t* zone) +{ + uint8_t buf[LDNS_MAX_DOMAINLEN+1]; + dname_pkt_copy(pkt, buf, comprname); + return dname_subdomain_c(buf, zone); +} + +/** check subdomain with decompression, compressed is parent */ +static int +sub_of_pkt(sldns_buffer* pkt, uint8_t* zone, uint8_t* comprname) +{ + uint8_t buf[LDNS_MAX_DOMAINLEN+1]; + dname_pkt_copy(pkt, buf, comprname); + return dname_subdomain_c(zone, buf); +} + +/** + * This routine normalizes a response. This includes removing "irrelevant" + * records from the answer and additional sections and (re)synthesizing + * CNAMEs from DNAMEs, if present. + * + * @param pkt: packet. + * @param msg: msg to normalize. + * @param qinfo: original query. + * @param region: where to allocate synthesized CNAMEs. + * @return 0 on error. + */ +static int +scrub_normalize(sldns_buffer* pkt, struct msg_parse* msg, + struct query_info* qinfo, struct regional* region) +{ + uint8_t* sname = qinfo->qname; + size_t snamelen = qinfo->qname_len; + struct rrset_parse* rrset, *prev, *nsset=NULL; + + if(FLAGS_GET_RCODE(msg->flags) != LDNS_RCODE_NOERROR && + FLAGS_GET_RCODE(msg->flags) != LDNS_RCODE_NXDOMAIN) + return 1; + + /* For the ANSWER section, remove all "irrelevant" records and add + * synthesized CNAMEs from DNAMEs + * This will strip out-of-order CNAMEs as well. */ + + /* walk through the parse packet rrset list, keep track of previous + * for insert and delete ease, and examine every RRset */ + prev = NULL; + rrset = msg->rrset_first; + while(rrset && rrset->section == LDNS_SECTION_ANSWER) { + if(rrset->type == LDNS_RR_TYPE_DNAME && + pkt_strict_sub(pkt, sname, rrset->dname)) { + /* check if next rrset is correct CNAME. else, + * synthesize a CNAME */ + struct rrset_parse* nx = rrset->rrset_all_next; + uint8_t alias[LDNS_MAX_DOMAINLEN+1]; + size_t aliaslen = 0; + if(rrset->rr_count != 1) { + verbose(VERB_ALGO, "Found DNAME rrset with " + "size > 1: %u", + (unsigned)rrset->rr_count); + return 0; + } + if(!synth_cname(sname, snamelen, rrset, alias, + &aliaslen, pkt)) { + verbose(VERB_ALGO, "synthesized CNAME " + "too long"); + return 0; + } + if(nx && nx->type == LDNS_RR_TYPE_CNAME && + dname_pkt_compare(pkt, sname, nx->dname) == 0) { + /* check next cname */ + uint8_t* t = NULL; + size_t tlen = 0; + if(!parse_get_cname_target(rrset, &t, &tlen)) + return 0; + if(dname_pkt_compare(pkt, alias, t) == 0) { + /* it's OK and better capitalized */ + prev = rrset; + rrset = nx; + continue; + } + /* synth ourselves */ + } + /* synth a CNAME rrset */ + prev = synth_cname_rrset(&sname, &snamelen, alias, + aliaslen, region, msg, rrset, rrset, nx, pkt); + if(!prev) { + log_err("out of memory synthesizing CNAME"); + return 0; + } + /* FIXME: resolve the conflict between synthesized + * CNAME ttls and the cache. */ + rrset = nx; + continue; + + } + + /* The only records in the ANSWER section not allowed to */ + if(dname_pkt_compare(pkt, sname, rrset->dname) != 0) { + remove_rrset("normalize: removing irrelevant RRset:", + pkt, msg, prev, &rrset); + continue; + } + + /* Follow the CNAME chain. */ + if(rrset->type == LDNS_RR_TYPE_CNAME) { + uint8_t* oldsname = sname; + if(!parse_get_cname_target(rrset, &sname, &snamelen)) + return 0; + prev = rrset; + rrset = rrset->rrset_all_next; + /* in CNAME ANY response, can have data after CNAME */ + if(qinfo->qtype == LDNS_RR_TYPE_ANY) { + while(rrset && rrset->section == + LDNS_SECTION_ANSWER && + dname_pkt_compare(pkt, oldsname, + rrset->dname) == 0) { + prev = rrset; + rrset = rrset->rrset_all_next; + } + } + continue; + } + + /* Otherwise, make sure that the RRset matches the qtype. */ + if(qinfo->qtype != LDNS_RR_TYPE_ANY && + qinfo->qtype != rrset->type) { + remove_rrset("normalize: removing irrelevant RRset:", + pkt, msg, prev, &rrset); + continue; + } + + /* Mark the additional names from relevant rrset as OK. */ + /* only for RRsets that match the query name, other ones + * will be removed by sanitize, so no additional for them */ + if(dname_pkt_compare(pkt, qinfo->qname, rrset->dname) == 0) + mark_additional_rrset(pkt, msg, rrset); + + prev = rrset; + rrset = rrset->rrset_all_next; + } + + /* Mark additional names from AUTHORITY */ + while(rrset && rrset->section == LDNS_SECTION_AUTHORITY) { + if(rrset->type==LDNS_RR_TYPE_DNAME || + rrset->type==LDNS_RR_TYPE_CNAME || + rrset->type==LDNS_RR_TYPE_A || + rrset->type==LDNS_RR_TYPE_AAAA) { + remove_rrset("normalize: removing irrelevant " + "RRset:", pkt, msg, prev, &rrset); + continue; + } + /* only one NS set allowed in authority section */ + if(rrset->type==LDNS_RR_TYPE_NS) { + /* NS set must be pertinent to the query */ + if(!sub_of_pkt(pkt, qinfo->qname, rrset->dname)) { + remove_rrset("normalize: removing irrelevant " + "RRset:", pkt, msg, prev, &rrset); + continue; + } + if(nsset == NULL) { + nsset = rrset; + } else { + remove_rrset("normalize: removing irrelevant " + "RRset:", pkt, msg, prev, &rrset); + continue; + } + } + mark_additional_rrset(pkt, msg, rrset); + prev = rrset; + rrset = rrset->rrset_all_next; + } + + /* For each record in the additional section, remove it if it is an + * address record and not in the collection of additional names + * found in ANSWER and AUTHORITY. */ + /* These records have not been marked OK previously */ + while(rrset && rrset->section == LDNS_SECTION_ADDITIONAL) { + /* FIXME: what about other types? */ + if(rrset->type==LDNS_RR_TYPE_A || + rrset->type==LDNS_RR_TYPE_AAAA) + { + if((rrset->flags & RRSET_SCRUB_OK)) { + /* remove flag to clean up flags variable */ + rrset->flags &= ~RRSET_SCRUB_OK; + } else { + remove_rrset("normalize: removing irrelevant " + "RRset:", pkt, msg, prev, &rrset); + continue; + } + } + if(rrset->type==LDNS_RR_TYPE_DNAME || + rrset->type==LDNS_RR_TYPE_CNAME || + rrset->type==LDNS_RR_TYPE_NS) { + remove_rrset("normalize: removing irrelevant " + "RRset:", pkt, msg, prev, &rrset); + continue; + } + prev = rrset; + rrset = rrset->rrset_all_next; + } + + return 1; +} + +/** + * Store potential poison in the cache (only if hardening disabled). + * The rrset is stored in the cache but removed from the message. + * So that it will be used for infrastructure purposes, but not be + * returned to the client. + * @param pkt: packet + * @param msg: message parsed + * @param env: environment with cache + * @param rrset: to store. + */ +static void +store_rrset(sldns_buffer* pkt, struct msg_parse* msg, struct module_env* env, + struct rrset_parse* rrset) +{ + struct ub_packed_rrset_key* k; + struct packed_rrset_data* d; + struct rrset_ref ref; + time_t now = *env->now; + + k = alloc_special_obtain(env->alloc); + if(!k) + return; + k->entry.data = NULL; + if(!parse_copy_decompress_rrset(pkt, msg, rrset, NULL, k)) { + alloc_special_release(env->alloc, k); + return; + } + d = (struct packed_rrset_data*)k->entry.data; + packed_rrset_ttl_add(d, now); + ref.key = k; + ref.id = k->id; + /*ignore ret: it was in the cache, ref updated */ + (void)rrset_cache_update(env->rrset_cache, &ref, env->alloc, now); +} + +/** Check if there are SOA records in the authority section (negative) */ +static int +soa_in_auth(struct msg_parse* msg) +{ + struct rrset_parse* rrset; + for(rrset = msg->rrset_first; rrset; rrset = rrset->rrset_all_next) + if(rrset->type == LDNS_RR_TYPE_SOA && + rrset->section == LDNS_SECTION_AUTHORITY) + return 1; + return 0; +} + +/** + * Check if right hand name in NSEC is within zone + * @param rrset: the NSEC rrset + * @param zonename: the zone name. + * @return true if BAD. + */ +static int sanitize_nsec_is_overreach(struct rrset_parse* rrset, + uint8_t* zonename) +{ + struct rr_parse* rr; + uint8_t* rhs; + size_t len; + log_assert(rrset->type == LDNS_RR_TYPE_NSEC); + for(rr = rrset->rr_first; rr; rr = rr->next) { + rhs = rr->ttl_data+4+2; + len = sldns_read_uint16(rr->ttl_data+4); + if(!dname_valid(rhs, len)) { + /* malformed domain name in rdata */ + return 1; + } + if(!dname_subdomain_c(rhs, zonename)) { + /* overreaching */ + return 1; + } + } + /* all NSEC RRs OK */ + return 0; +} + +/** + * Given a response event, remove suspect RRsets from the response. + * "Suspect" rrsets are potentially poison. Note that this routine expects + * the response to be in a "normalized" state -- that is, all "irrelevant" + * RRsets have already been removed, CNAMEs are in order, etc. + * + * @param pkt: packet. + * @param msg: msg to normalize. + * @param qinfo: the question originally asked. + * @param zonename: name of server zone. + * @param env: module environment with config and cache. + * @param ie: iterator environment with private address data. + * @return 0 on error. + */ +static int +scrub_sanitize(sldns_buffer* pkt, struct msg_parse* msg, + struct query_info* qinfo, uint8_t* zonename, struct module_env* env, + struct iter_env* ie) +{ + int del_addi = 0; /* if additional-holding rrsets are deleted, we + do not trust the normalized additional-A-AAAA any more */ + struct rrset_parse* rrset, *prev; + prev = NULL; + rrset = msg->rrset_first; + + /* the first DNAME is allowed to stay. It needs checking before + * it can be used from the cache. After normalization, an initial + * DNAME will have a correctly synthesized CNAME after it. */ + if(rrset && rrset->type == LDNS_RR_TYPE_DNAME && + rrset->section == LDNS_SECTION_ANSWER && + pkt_strict_sub(pkt, qinfo->qname, rrset->dname) && + pkt_sub(pkt, rrset->dname, zonename)) { + prev = rrset; /* DNAME allowed to stay in answer section */ + rrset = rrset->rrset_all_next; + } + + /* remove all records from the answer section that are + * not the same domain name as the query domain name. + * The answer section should contain rrsets with the same name + * as the question. For DNAMEs a CNAME has been synthesized. + * Wildcards have the query name in answer section. + * ANY queries get query name in answer section. + * Remainders of CNAME chains are cut off and resolved by iterator. */ + while(rrset && rrset->section == LDNS_SECTION_ANSWER) { + if(dname_pkt_compare(pkt, qinfo->qname, rrset->dname) != 0) { + if(has_additional(rrset->type)) del_addi = 1; + remove_rrset("sanitize: removing extraneous answer " + "RRset:", pkt, msg, prev, &rrset); + continue; + } + prev = rrset; + rrset = rrset->rrset_all_next; + } + + /* At this point, we brutally remove ALL rrsets that aren't + * children of the originating zone. The idea here is that, + * as far as we know, the server that we contacted is ONLY + * authoritative for the originating zone. It, of course, MAY + * be authoriative for any other zones, and of course, MAY + * NOT be authoritative for some subdomains of the originating + * zone. */ + prev = NULL; + rrset = msg->rrset_first; + while(rrset) { + + /* remove private addresses */ + if( (rrset->type == LDNS_RR_TYPE_A || + rrset->type == LDNS_RR_TYPE_AAAA)) { + + /* do not set servfail since this leads to too + * many drops of other people using rfc1918 space */ + /* also do not remove entire rrset, unless all records + * in it are bad */ + if(priv_rrset_bad(ie->priv, pkt, rrset)) { + remove_rrset(NULL, pkt, msg, prev, &rrset); + continue; + } + } + + /* skip DNAME records -- they will always be followed by a + * synthesized CNAME, which will be relevant. + * FIXME: should this do something differently with DNAME + * rrsets NOT in Section.ANSWER? */ + /* But since DNAME records are also subdomains of the zone, + * same check can be used */ + + if(!pkt_sub(pkt, rrset->dname, zonename)) { + if(msg->an_rrsets == 0 && + rrset->type == LDNS_RR_TYPE_NS && + rrset->section == LDNS_SECTION_AUTHORITY && + FLAGS_GET_RCODE(msg->flags) == + LDNS_RCODE_NOERROR && !soa_in_auth(msg) && + sub_of_pkt(pkt, zonename, rrset->dname)) { + /* noerror, nodata and this NS rrset is above + * the zone. This is LAME! + * Leave in the NS for lame classification. */ + /* remove everything from the additional + * (we dont want its glue that was approved + * during the normalize action) */ + del_addi = 1; + } else if(!env->cfg->harden_glue) { + /* store in cache! Since it is relevant + * (from normalize) it will be picked up + * from the cache to be used later */ + store_rrset(pkt, msg, env, rrset); + remove_rrset("sanitize: storing potential " + "poison RRset:", pkt, msg, prev, &rrset); + continue; + } else { + if(has_additional(rrset->type)) del_addi = 1; + remove_rrset("sanitize: removing potential " + "poison RRset:", pkt, msg, prev, &rrset); + continue; + } + } + if(del_addi && rrset->section == LDNS_SECTION_ADDITIONAL) { + remove_rrset("sanitize: removing potential " + "poison reference RRset:", pkt, msg, prev, &rrset); + continue; + } + /* check if right hand side of NSEC is within zone */ + if(rrset->type == LDNS_RR_TYPE_NSEC && + sanitize_nsec_is_overreach(rrset, zonename)) { + remove_rrset("sanitize: removing overreaching NSEC " + "RRset:", pkt, msg, prev, &rrset); + continue; + } + prev = rrset; + rrset = rrset->rrset_all_next; + } + return 1; +} + +int +scrub_message(sldns_buffer* pkt, struct msg_parse* msg, + struct query_info* qinfo, uint8_t* zonename, struct regional* region, + struct module_env* env, struct iter_env* ie) +{ + /* basic sanity checks */ + log_nametypeclass(VERB_ALGO, "scrub for", zonename, LDNS_RR_TYPE_NS, + qinfo->qclass); + if(msg->qdcount > 1) + return 0; + if( !(msg->flags&BIT_QR) ) + return 0; + msg->flags &= ~(BIT_AD|BIT_Z); /* force off bit AD and Z */ + + /* make sure that a query is echoed back when NOERROR or NXDOMAIN */ + /* this is not required for basic operation but is a forgery + * resistance (security) feature */ + if((FLAGS_GET_RCODE(msg->flags) == LDNS_RCODE_NOERROR || + FLAGS_GET_RCODE(msg->flags) == LDNS_RCODE_NXDOMAIN) && + msg->qdcount == 0) + return 0; + + /* if a query is echoed back, make sure it is correct. Otherwise, + * this may be not a reply to our query. */ + if(msg->qdcount == 1) { + if(dname_pkt_compare(pkt, msg->qname, qinfo->qname) != 0) + return 0; + if(msg->qtype != qinfo->qtype || msg->qclass != qinfo->qclass) + return 0; + } + + /* normalize the response, this cleans up the additional. */ + if(!scrub_normalize(pkt, msg, qinfo, region)) + return 0; + /* delete all out-of-zone information */ + if(!scrub_sanitize(pkt, msg, qinfo, zonename, env, ie)) + return 0; + return 1; +} diff --git a/external/unbound/iterator/iter_scrub.h b/external/unbound/iterator/iter_scrub.h new file mode 100644 index 000000000..cbbaf73c9 --- /dev/null +++ b/external/unbound/iterator/iter_scrub.h @@ -0,0 +1,69 @@ +/* + * iterator/iter_scrub.h - scrubbing, normalization, sanitization of DNS msgs. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file has routine(s) for cleaning up incoming DNS messages from + * possible useless or malicious junk in it. + */ + +#ifndef ITERATOR_ITER_SCRUB_H +#define ITERATOR_ITER_SCRUB_H +struct sldns_buffer; +struct msg_parse; +struct query_info; +struct regional; +struct module_env; +struct iter_env; + +/** + * Cleanup the passed dns message. + * @param pkt: the packet itself, for resolving name compression pointers. + * the packet buffer is unaltered. + * @param msg: the parsed packet, this structure is cleaned up. + * @param qinfo: the query info that was sent to the server. Checked. + * @param zonename: the name of the last delegation point. + * Used to determine out of bailiwick information. + * @param regional: where to allocate (new) parts of the message. + * @param env: module environment with config settings and cache. + * @param ie: iterator module environment data. + * @return: false if the message is total waste. true if scrubbed with success. + */ +int scrub_message(struct sldns_buffer* pkt, struct msg_parse* msg, + struct query_info* qinfo, uint8_t* zonename, struct regional* regional, + struct module_env* env, struct iter_env* ie); + +#endif /* ITERATOR_ITER_SCRUB_H */ diff --git a/external/unbound/iterator/iter_utils.c b/external/unbound/iterator/iter_utils.c new file mode 100644 index 000000000..5d55b623e --- /dev/null +++ b/external/unbound/iterator/iter_utils.c @@ -0,0 +1,1024 @@ +/* + * iterator/iter_utils.c - iterative resolver module utility functions. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file contains functions to assist the iterator module. + * Configuration options. Forward zones. + */ +#include "config.h" +#include "iterator/iter_utils.h" +#include "iterator/iterator.h" +#include "iterator/iter_hints.h" +#include "iterator/iter_fwd.h" +#include "iterator/iter_donotq.h" +#include "iterator/iter_delegpt.h" +#include "iterator/iter_priv.h" +#include "services/cache/infra.h" +#include "services/cache/dns.h" +#include "services/cache/rrset.h" +#include "util/net_help.h" +#include "util/module.h" +#include "util/log.h" +#include "util/config_file.h" +#include "util/regional.h" +#include "util/data/msgparse.h" +#include "util/data/dname.h" +#include "util/random.h" +#include "util/fptr_wlist.h" +#include "validator/val_anchor.h" +#include "validator/val_kcache.h" +#include "validator/val_kentry.h" +#include "validator/val_utils.h" +#include "validator/val_sigcrypt.h" +#include "ldns/sbuffer.h" + +/** time when nameserver glue is said to be 'recent' */ +#define SUSPICION_RECENT_EXPIRY 86400 +/** penalty to validation failed blacklisted IPs */ +#define BLACKLIST_PENALTY (USEFUL_SERVER_TOP_TIMEOUT*4) + +/** fillup fetch policy array */ +static void +fetch_fill(struct iter_env* ie, const char* str) +{ + char* s = (char*)str, *e; + int i; + for(i=0; i<ie->max_dependency_depth+1; i++) { + ie->target_fetch_policy[i] = strtol(s, &e, 10); + if(s == e) + fatal_exit("cannot parse fetch policy number %s", s); + s = e; + } +} + +/** Read config string that represents the target fetch policy */ +static int +read_fetch_policy(struct iter_env* ie, const char* str) +{ + int count = cfg_count_numbers(str); + if(count < 1) { + log_err("Cannot parse target fetch policy: \"%s\"", str); + return 0; + } + ie->max_dependency_depth = count - 1; + ie->target_fetch_policy = (int*)calloc( + (size_t)ie->max_dependency_depth+1, sizeof(int)); + if(!ie->target_fetch_policy) { + log_err("alloc fetch policy: out of memory"); + return 0; + } + fetch_fill(ie, str); + return 1; +} + +int +iter_apply_cfg(struct iter_env* iter_env, struct config_file* cfg) +{ + int i; + /* target fetch policy */ + if(!read_fetch_policy(iter_env, cfg->target_fetch_policy)) + return 0; + for(i=0; i<iter_env->max_dependency_depth+1; i++) + verbose(VERB_QUERY, "target fetch policy for level %d is %d", + i, iter_env->target_fetch_policy[i]); + + if(!iter_env->donotq) + iter_env->donotq = donotq_create(); + if(!iter_env->donotq || !donotq_apply_cfg(iter_env->donotq, cfg)) { + log_err("Could not set donotqueryaddresses"); + return 0; + } + if(!iter_env->priv) + iter_env->priv = priv_create(); + if(!iter_env->priv || !priv_apply_cfg(iter_env->priv, cfg)) { + log_err("Could not set private addresses"); + return 0; + } + iter_env->supports_ipv6 = cfg->do_ip6; + iter_env->supports_ipv4 = cfg->do_ip4; + return 1; +} + +/** filter out unsuitable targets + * @param iter_env: iterator environment with ipv6-support flag. + * @param env: module environment with infra cache. + * @param name: zone name + * @param namelen: length of name + * @param qtype: query type (host order). + * @param now: current time + * @param a: address in delegation point we are examining. + * @return an integer that signals the target suitability. + * as follows: + * -1: The address should be omitted from the list. + * Because: + * o The address is bogus (DNSSEC validation failure). + * o Listed as donotquery + * o is ipv6 but no ipv6 support (in operating system). + * o is ipv4 but no ipv4 support (in operating system). + * o is lame + * Otherwise, an rtt in milliseconds. + * 0 .. USEFUL_SERVER_TOP_TIMEOUT-1 + * The roundtrip time timeout estimate. less than 2 minutes. + * Note that util/rtt.c has a MIN_TIMEOUT of 50 msec, thus + * values 0 .. 49 are not used, unless that is changed. + * USEFUL_SERVER_TOP_TIMEOUT + * This value exactly is given for unresponsive blacklisted. + * USEFUL_SERVER_TOP_TIMEOUT+1 + * For non-blacklisted servers: huge timeout, but has traffic. + * USEFUL_SERVER_TOP_TIMEOUT*1 .. + * parent-side lame servers get this penalty. A dispreferential + * server. (lame in delegpt). + * USEFUL_SERVER_TOP_TIMEOUT*2 .. + * dnsseclame servers get penalty + * USEFUL_SERVER_TOP_TIMEOUT*3 .. + * recursion lame servers get penalty + * UNKNOWN_SERVER_NICENESS + * If no information is known about the server, this is + * returned. 376 msec or so. + * +BLACKLIST_PENALTY (of USEFUL_TOP_TIMEOUT*4) for dnssec failed IPs. + * + * When a final value is chosen that is dnsseclame ; dnsseclameness checking + * is turned off (so we do not discard the reply). + * When a final value is chosen that is recursionlame; RD bit is set on query. + * Because of the numbers this means recursionlame also have dnssec lameness + * checking turned off. + */ +static int +iter_filter_unsuitable(struct iter_env* iter_env, struct module_env* env, + uint8_t* name, size_t namelen, uint16_t qtype, time_t now, + struct delegpt_addr* a) +{ + int rtt, lame, reclame, dnsseclame; + if(a->bogus) + return -1; /* address of server is bogus */ + if(donotq_lookup(iter_env->donotq, &a->addr, a->addrlen)) { + log_addr(VERB_ALGO, "skip addr on the donotquery list", + &a->addr, a->addrlen); + return -1; /* server is on the donotquery list */ + } + if(!iter_env->supports_ipv6 && addr_is_ip6(&a->addr, a->addrlen)) { + return -1; /* there is no ip6 available */ + } + if(!iter_env->supports_ipv4 && !addr_is_ip6(&a->addr, a->addrlen)) { + return -1; /* there is no ip4 available */ + } + /* check lameness - need zone , class info */ + if(infra_get_lame_rtt(env->infra_cache, &a->addr, a->addrlen, + name, namelen, qtype, &lame, &dnsseclame, &reclame, + &rtt, now)) { + log_addr(VERB_ALGO, "servselect", &a->addr, a->addrlen); + verbose(VERB_ALGO, " rtt=%d%s%s%s%s", rtt, + lame?" LAME":"", + dnsseclame?" DNSSEC_LAME":"", + reclame?" REC_LAME":"", + a->lame?" ADDR_LAME":""); + if(lame) + return -1; /* server is lame */ + else if(rtt >= USEFUL_SERVER_TOP_TIMEOUT) + /* server is unresponsive, + * we used to return TOP_TIMOUT, but fairly useless, + * because if == TOP_TIMEOUT is dropped because + * blacklisted later, instead, remove it here, so + * other choices (that are not blacklisted) can be + * tried */ + return -1; + /* select remainder from worst to best */ + else if(reclame) + return rtt+USEFUL_SERVER_TOP_TIMEOUT*3; /* nonpref */ + else if(dnsseclame || a->dnsseclame) + return rtt+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */ + else if(a->lame) + return rtt+USEFUL_SERVER_TOP_TIMEOUT+1; /* nonpref */ + else return rtt; + } + /* no server information present */ + if(a->dnsseclame) + return UNKNOWN_SERVER_NICENESS+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */ + else if(a->lame) + return USEFUL_SERVER_TOP_TIMEOUT+1+UNKNOWN_SERVER_NICENESS; /* nonpref */ + return UNKNOWN_SERVER_NICENESS; +} + +/** lookup RTT information, and also store fastest rtt (if any) */ +static int +iter_fill_rtt(struct iter_env* iter_env, struct module_env* env, + uint8_t* name, size_t namelen, uint16_t qtype, time_t now, + struct delegpt* dp, int* best_rtt, struct sock_list* blacklist) +{ + int got_it = 0; + struct delegpt_addr* a; + if(dp->bogus) + return 0; /* NS bogus, all bogus, nothing found */ + for(a=dp->result_list; a; a = a->next_result) { + a->sel_rtt = iter_filter_unsuitable(iter_env, env, + name, namelen, qtype, now, a); + if(a->sel_rtt != -1) { + if(sock_list_find(blacklist, &a->addr, a->addrlen)) + a->sel_rtt += BLACKLIST_PENALTY; + + if(!got_it) { + *best_rtt = a->sel_rtt; + got_it = 1; + } else if(a->sel_rtt < *best_rtt) { + *best_rtt = a->sel_rtt; + } + } + } + return got_it; +} + +/** filter the addres list, putting best targets at front, + * returns number of best targets (or 0, no suitable targets) */ +static int +iter_filter_order(struct iter_env* iter_env, struct module_env* env, + uint8_t* name, size_t namelen, uint16_t qtype, time_t now, + struct delegpt* dp, int* selected_rtt, int open_target, + struct sock_list* blacklist) +{ + int got_num = 0, low_rtt = 0, swap_to_front; + struct delegpt_addr* a, *n, *prev=NULL; + + /* fillup sel_rtt and find best rtt in the bunch */ + got_num = iter_fill_rtt(iter_env, env, name, namelen, qtype, now, dp, + &low_rtt, blacklist); + if(got_num == 0) + return 0; + if(low_rtt >= USEFUL_SERVER_TOP_TIMEOUT && + (delegpt_count_missing_targets(dp) > 0 || open_target > 0)) { + verbose(VERB_ALGO, "Bad choices, trying to get more choice"); + return 0; /* we want more choice. The best choice is a bad one. + return 0 to force the caller to fetch more */ + } + + got_num = 0; + a = dp->result_list; + while(a) { + /* skip unsuitable targets */ + if(a->sel_rtt == -1) { + prev = a; + a = a->next_result; + continue; + } + /* classify the server address and determine what to do */ + swap_to_front = 0; + if(a->sel_rtt >= low_rtt && a->sel_rtt - low_rtt <= RTT_BAND) { + got_num++; + swap_to_front = 1; + } else if(a->sel_rtt<low_rtt && low_rtt-a->sel_rtt<=RTT_BAND) { + got_num++; + swap_to_front = 1; + } + /* swap to front if necessary, or move to next result */ + if(swap_to_front && prev) { + n = a->next_result; + prev->next_result = n; + a->next_result = dp->result_list; + dp->result_list = a; + a = n; + } else { + prev = a; + a = a->next_result; + } + } + *selected_rtt = low_rtt; + return got_num; +} + +struct delegpt_addr* +iter_server_selection(struct iter_env* iter_env, + struct module_env* env, struct delegpt* dp, + uint8_t* name, size_t namelen, uint16_t qtype, int* dnssec_lame, + int* chase_to_rd, int open_target, struct sock_list* blacklist) +{ + int sel; + int selrtt; + struct delegpt_addr* a, *prev; + int num = iter_filter_order(iter_env, env, name, namelen, qtype, + *env->now, dp, &selrtt, open_target, blacklist); + + if(num == 0) + return NULL; + verbose(VERB_ALGO, "selrtt %d", selrtt); + if(selrtt > BLACKLIST_PENALTY) { + if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*3) { + verbose(VERB_ALGO, "chase to " + "blacklisted recursion lame server"); + *chase_to_rd = 1; + } + if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*2) { + verbose(VERB_ALGO, "chase to " + "blacklisted dnssec lame server"); + *dnssec_lame = 1; + } + } else { + if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*3) { + verbose(VERB_ALGO, "chase to recursion lame server"); + *chase_to_rd = 1; + } + if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*2) { + verbose(VERB_ALGO, "chase to dnssec lame server"); + *dnssec_lame = 1; + } + if(selrtt == USEFUL_SERVER_TOP_TIMEOUT) { + verbose(VERB_ALGO, "chase to blacklisted lame server"); + return NULL; + } + } + + if(num == 1) { + a = dp->result_list; + if(++a->attempts < OUTBOUND_MSG_RETRY) + return a; + dp->result_list = a->next_result; + return a; + } + + /* randomly select a target from the list */ + log_assert(num > 1); + /* grab secure random number, to pick unexpected server. + * also we need it to be threadsafe. */ + sel = ub_random_max(env->rnd, num); + a = dp->result_list; + prev = NULL; + while(sel > 0 && a) { + prev = a; + a = a->next_result; + sel--; + } + if(!a) /* robustness */ + return NULL; + if(++a->attempts < OUTBOUND_MSG_RETRY) + return a; + /* remove it from the delegation point result list */ + if(prev) + prev->next_result = a->next_result; + else dp->result_list = a->next_result; + return a; +} + +struct dns_msg* +dns_alloc_msg(sldns_buffer* pkt, struct msg_parse* msg, + struct regional* region) +{ + struct dns_msg* m = (struct dns_msg*)regional_alloc(region, + sizeof(struct dns_msg)); + if(!m) + return NULL; + memset(m, 0, sizeof(*m)); + if(!parse_create_msg(pkt, msg, NULL, &m->qinfo, &m->rep, region)) { + log_err("malloc failure: allocating incoming dns_msg"); + return NULL; + } + return m; +} + +struct dns_msg* +dns_copy_msg(struct dns_msg* from, struct regional* region) +{ + struct dns_msg* m = (struct dns_msg*)regional_alloc(region, + sizeof(struct dns_msg)); + if(!m) + return NULL; + m->qinfo = from->qinfo; + if(!(m->qinfo.qname = regional_alloc_init(region, from->qinfo.qname, + from->qinfo.qname_len))) + return NULL; + if(!(m->rep = reply_info_copy(from->rep, NULL, region))) + return NULL; + return m; +} + +void +iter_dns_store(struct module_env* env, struct query_info* msgqinf, + struct reply_info* msgrep, int is_referral, time_t leeway, int pside, + struct regional* region) +{ + if(!dns_cache_store(env, msgqinf, msgrep, is_referral, leeway, + pside, region)) + log_err("out of memory: cannot store data in cache"); +} + +int +iter_ns_probability(struct ub_randstate* rnd, int n, int m) +{ + int sel; + if(n == m) /* 100% chance */ + return 1; + /* we do not need secure random numbers here, but + * we do need it to be threadsafe, so we use this */ + sel = ub_random_max(rnd, m); + return (sel < n); +} + +/** detect dependency cycle for query and target */ +static int +causes_cycle(struct module_qstate* qstate, uint8_t* name, size_t namelen, + uint16_t t, uint16_t c) +{ + struct query_info qinf; + qinf.qname = name; + qinf.qname_len = namelen; + qinf.qtype = t; + qinf.qclass = c; + fptr_ok(fptr_whitelist_modenv_detect_cycle( + qstate->env->detect_cycle)); + return (*qstate->env->detect_cycle)(qstate, &qinf, + (uint16_t)(BIT_RD|BIT_CD), qstate->is_priming); +} + +void +iter_mark_cycle_targets(struct module_qstate* qstate, struct delegpt* dp) +{ + struct delegpt_ns* ns; + for(ns = dp->nslist; ns; ns = ns->next) { + if(ns->resolved) + continue; + /* see if this ns as target causes dependency cycle */ + if(causes_cycle(qstate, ns->name, ns->namelen, + LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass) || + causes_cycle(qstate, ns->name, ns->namelen, + LDNS_RR_TYPE_A, qstate->qinfo.qclass)) { + log_nametypeclass(VERB_QUERY, "skipping target due " + "to dependency cycle (harden-glue: no may " + "fix some of the cycles)", + ns->name, LDNS_RR_TYPE_A, + qstate->qinfo.qclass); + ns->resolved = 1; + } + } +} + +void +iter_mark_pside_cycle_targets(struct module_qstate* qstate, struct delegpt* dp) +{ + struct delegpt_ns* ns; + for(ns = dp->nslist; ns; ns = ns->next) { + if(ns->done_pside4 && ns->done_pside6) + continue; + /* see if this ns as target causes dependency cycle */ + if(causes_cycle(qstate, ns->name, ns->namelen, + LDNS_RR_TYPE_A, qstate->qinfo.qclass)) { + log_nametypeclass(VERB_QUERY, "skipping target due " + "to dependency cycle", ns->name, + LDNS_RR_TYPE_A, qstate->qinfo.qclass); + ns->done_pside4 = 1; + } + if(causes_cycle(qstate, ns->name, ns->namelen, + LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass)) { + log_nametypeclass(VERB_QUERY, "skipping target due " + "to dependency cycle", ns->name, + LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass); + ns->done_pside6 = 1; + } + } +} + +int +iter_dp_is_useless(struct query_info* qinfo, uint16_t qflags, + struct delegpt* dp) +{ + struct delegpt_ns* ns; + /* check: + * o RD qflag is on. + * o no addresses are provided. + * o all NS items are required glue. + * OR + * o RD qflag is on. + * o no addresses are provided. + * o the query is for one of the nameservers in dp, + * and that nameserver is a glue-name for this dp. + */ + if(!(qflags&BIT_RD)) + return 0; + /* either available or unused targets */ + if(dp->usable_list || dp->result_list) + return 0; + + /* see if query is for one of the nameservers, which is glue */ + if( (qinfo->qtype == LDNS_RR_TYPE_A || + qinfo->qtype == LDNS_RR_TYPE_AAAA) && + dname_subdomain_c(qinfo->qname, dp->name) && + delegpt_find_ns(dp, qinfo->qname, qinfo->qname_len)) + return 1; + + for(ns = dp->nslist; ns; ns = ns->next) { + if(ns->resolved) /* skip failed targets */ + continue; + if(!dname_subdomain_c(ns->name, dp->name)) + return 0; /* one address is not required glue */ + } + return 1; +} + +int +iter_indicates_dnssec(struct module_env* env, struct delegpt* dp, + struct dns_msg* msg, uint16_t dclass) +{ + struct trust_anchor* a; + /* information not available, !env->anchors can be common */ + if(!env || !env->anchors || !dp || !dp->name) + return 0; + /* a trust anchor exists with this name, RRSIGs expected */ + if((a=anchor_find(env->anchors, dp->name, dp->namelabs, dp->namelen, + dclass))) { + lock_basic_unlock(&a->lock); + return 1; + } + /* see if DS rrset was given, in AUTH section */ + if(msg && msg->rep && + reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, + LDNS_RR_TYPE_DS, dclass)) + return 1; + /* look in key cache */ + if(env->key_cache) { + struct key_entry_key* kk = key_cache_obtain(env->key_cache, + dp->name, dp->namelen, dclass, env->scratch, *env->now); + if(kk) { + if(query_dname_compare(kk->name, dp->name) == 0) { + if(key_entry_isgood(kk) || key_entry_isbad(kk)) { + regional_free_all(env->scratch); + return 1; + } else if(key_entry_isnull(kk)) { + regional_free_all(env->scratch); + return 0; + } + } + regional_free_all(env->scratch); + } + } + return 0; +} + +int +iter_msg_has_dnssec(struct dns_msg* msg) +{ + size_t i; + if(!msg || !msg->rep) + return 0; + for(i=0; i<msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) { + if(((struct packed_rrset_data*)msg->rep->rrsets[i]-> + entry.data)->rrsig_count > 0) + return 1; + } + /* empty message has no DNSSEC info, with DNSSEC the reply is + * not empty (NSEC) */ + return 0; +} + +int iter_msg_from_zone(struct dns_msg* msg, struct delegpt* dp, + enum response_type type, uint16_t dclass) +{ + if(!msg || !dp || !msg->rep || !dp->name) + return 0; + /* SOA RRset - always from reply zone */ + if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, + LDNS_RR_TYPE_SOA, dclass) || + reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, + LDNS_RR_TYPE_SOA, dclass)) + return 1; + if(type == RESPONSE_TYPE_REFERRAL) { + size_t i; + /* if it adds a single label, i.e. we expect .com, + * and referral to example.com. NS ... , then origin zone + * is .com. For a referral to sub.example.com. NS ... then + * we do not know, since example.com. may be in between. */ + for(i=0; i<msg->rep->an_numrrsets+msg->rep->ns_numrrsets; + i++) { + struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; + if(ntohs(s->rk.type) == LDNS_RR_TYPE_NS && + ntohs(s->rk.rrset_class) == dclass) { + int l = dname_count_labels(s->rk.dname); + if(l == dp->namelabs + 1 && + dname_strict_subdomain(s->rk.dname, + l, dp->name, dp->namelabs)) + return 1; + } + } + return 0; + } + log_assert(type==RESPONSE_TYPE_ANSWER || type==RESPONSE_TYPE_CNAME); + /* not a referral, and not lame delegation (upwards), so, + * any NS rrset must be from the zone itself */ + if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, + LDNS_RR_TYPE_NS, dclass) || + reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, + LDNS_RR_TYPE_NS, dclass)) + return 1; + /* a DNSKEY set is expected at the zone apex as well */ + /* this is for 'minimal responses' for DNSKEYs */ + if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, + LDNS_RR_TYPE_DNSKEY, dclass)) + return 1; + return 0; +} + +/** + * check equality of two rrsets + * @param k1: rrset + * @param k2: rrset + * @return true if equal + */ +static int +rrset_equal(struct ub_packed_rrset_key* k1, struct ub_packed_rrset_key* k2) +{ + struct packed_rrset_data* d1 = (struct packed_rrset_data*) + k1->entry.data; + struct packed_rrset_data* d2 = (struct packed_rrset_data*) + k2->entry.data; + size_t i, t; + if(k1->rk.dname_len != k2->rk.dname_len || + k1->rk.flags != k2->rk.flags || + k1->rk.type != k2->rk.type || + k1->rk.rrset_class != k2->rk.rrset_class || + query_dname_compare(k1->rk.dname, k2->rk.dname) != 0) + return 0; + if(d1->ttl != d2->ttl || + d1->count != d2->count || + d1->rrsig_count != d2->rrsig_count || + d1->trust != d2->trust || + d1->security != d2->security) + return 0; + t = d1->count + d1->rrsig_count; + for(i=0; i<t; i++) { + if(d1->rr_len[i] != d2->rr_len[i] || + d1->rr_ttl[i] != d2->rr_ttl[i] || + memcmp(d1->rr_data[i], d2->rr_data[i], + d1->rr_len[i]) != 0) + return 0; + } + return 1; +} + +int +reply_equal(struct reply_info* p, struct reply_info* q, struct regional* region) +{ + size_t i; + if(p->flags != q->flags || + p->qdcount != q->qdcount || + p->ttl != q->ttl || + p->prefetch_ttl != q->prefetch_ttl || + p->security != q->security || + p->an_numrrsets != q->an_numrrsets || + p->ns_numrrsets != q->ns_numrrsets || + p->ar_numrrsets != q->ar_numrrsets || + p->rrset_count != q->rrset_count) + return 0; + for(i=0; i<p->rrset_count; i++) { + if(!rrset_equal(p->rrsets[i], q->rrsets[i])) { + if(!rrset_canonical_equal(region, p->rrsets[i], + q->rrsets[i])) { + regional_free_all(region); + return 0; + } + regional_free_all(region); + } + } + return 1; +} + +void +iter_store_parentside_rrset(struct module_env* env, + struct ub_packed_rrset_key* rrset) +{ + struct rrset_ref ref; + rrset = packed_rrset_copy_alloc(rrset, env->alloc, *env->now); + if(!rrset) { + log_err("malloc failure in store_parentside_rrset"); + return; + } + rrset->rk.flags |= PACKED_RRSET_PARENT_SIDE; + rrset->entry.hash = rrset_key_hash(&rrset->rk); + ref.key = rrset; + ref.id = rrset->id; + /* ignore ret: if it was in the cache, ref updated */ + (void)rrset_cache_update(env->rrset_cache, &ref, env->alloc, *env->now); +} + +/** fetch NS record from reply, if any */ +static struct ub_packed_rrset_key* +reply_get_NS_rrset(struct reply_info* rep) +{ + size_t i; + for(i=0; i<rep->rrset_count; i++) { + if(rep->rrsets[i]->rk.type == htons(LDNS_RR_TYPE_NS)) { + return rep->rrsets[i]; + } + } + return NULL; +} + +void +iter_store_parentside_NS(struct module_env* env, struct reply_info* rep) +{ + struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep); + if(rrset) { + log_rrset_key(VERB_ALGO, "store parent-side NS", rrset); + iter_store_parentside_rrset(env, rrset); + } +} + +void iter_store_parentside_neg(struct module_env* env, + struct query_info* qinfo, struct reply_info* rep) +{ + /* TTL: NS from referral in iq->deleg_msg, + * or first RR from iq->response, + * or servfail5secs if !iq->response */ + time_t ttl = NORR_TTL; + struct ub_packed_rrset_key* neg; + struct packed_rrset_data* newd; + if(rep) { + struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep); + if(!rrset && rep->rrset_count != 0) rrset = rep->rrsets[0]; + if(rrset) ttl = ub_packed_rrset_ttl(rrset); + } + /* create empty rrset to store */ + neg = (struct ub_packed_rrset_key*)regional_alloc(env->scratch, + sizeof(struct ub_packed_rrset_key)); + if(!neg) { + log_err("out of memory in store_parentside_neg"); + return; + } + memset(&neg->entry, 0, sizeof(neg->entry)); + neg->entry.key = neg; + neg->rk.type = htons(qinfo->qtype); + neg->rk.rrset_class = htons(qinfo->qclass); + neg->rk.flags = 0; + neg->rk.dname = regional_alloc_init(env->scratch, qinfo->qname, + qinfo->qname_len); + if(!neg->rk.dname) { + log_err("out of memory in store_parentside_neg"); + return; + } + neg->rk.dname_len = qinfo->qname_len; + neg->entry.hash = rrset_key_hash(&neg->rk); + newd = (struct packed_rrset_data*)regional_alloc_zero(env->scratch, + sizeof(struct packed_rrset_data) + sizeof(size_t) + + sizeof(uint8_t*) + sizeof(time_t) + sizeof(uint16_t)); + if(!newd) { + log_err("out of memory in store_parentside_neg"); + return; + } + neg->entry.data = newd; + newd->ttl = ttl; + /* entry must have one RR, otherwise not valid in cache. + * put in one RR with empty rdata: those are ignored as nameserver */ + newd->count = 1; + newd->rrsig_count = 0; + newd->trust = rrset_trust_ans_noAA; + newd->rr_len = (size_t*)((uint8_t*)newd + + sizeof(struct packed_rrset_data)); + newd->rr_len[0] = 0 /* zero len rdata */ + sizeof(uint16_t); + packed_rrset_ptr_fixup(newd); + newd->rr_ttl[0] = newd->ttl; + sldns_write_uint16(newd->rr_data[0], 0 /* zero len rdata */); + /* store it */ + log_rrset_key(VERB_ALGO, "store parent-side negative", neg); + iter_store_parentside_rrset(env, neg); +} + +int +iter_lookup_parent_NS_from_cache(struct module_env* env, struct delegpt* dp, + struct regional* region, struct query_info* qinfo) +{ + struct ub_packed_rrset_key* akey; + akey = rrset_cache_lookup(env->rrset_cache, dp->name, + dp->namelen, LDNS_RR_TYPE_NS, qinfo->qclass, + PACKED_RRSET_PARENT_SIDE, *env->now, 0); + if(akey) { + log_rrset_key(VERB_ALGO, "found parent-side NS in cache", akey); + dp->has_parent_side_NS = 1; + /* and mark the new names as lame */ + if(!delegpt_rrset_add_ns(dp, region, akey, 1)) { + lock_rw_unlock(&akey->entry.lock); + return 0; + } + lock_rw_unlock(&akey->entry.lock); + } + return 1; +} + +int iter_lookup_parent_glue_from_cache(struct module_env* env, + struct delegpt* dp, struct regional* region, struct query_info* qinfo) +{ + struct ub_packed_rrset_key* akey; + struct delegpt_ns* ns; + size_t num = delegpt_count_targets(dp); + for(ns = dp->nslist; ns; ns = ns->next) { + /* get cached parentside A */ + akey = rrset_cache_lookup(env->rrset_cache, ns->name, + ns->namelen, LDNS_RR_TYPE_A, qinfo->qclass, + PACKED_RRSET_PARENT_SIDE, *env->now, 0); + if(akey) { + log_rrset_key(VERB_ALGO, "found parent-side", akey); + ns->done_pside4 = 1; + /* a negative-cache-element has no addresses it adds */ + if(!delegpt_add_rrset_A(dp, region, akey, 1)) + log_err("malloc failure in lookup_parent_glue"); + lock_rw_unlock(&akey->entry.lock); + } + /* get cached parentside AAAA */ + akey = rrset_cache_lookup(env->rrset_cache, ns->name, + ns->namelen, LDNS_RR_TYPE_AAAA, qinfo->qclass, + PACKED_RRSET_PARENT_SIDE, *env->now, 0); + if(akey) { + log_rrset_key(VERB_ALGO, "found parent-side", akey); + ns->done_pside6 = 1; + /* a negative-cache-element has no addresses it adds */ + if(!delegpt_add_rrset_AAAA(dp, region, akey, 1)) + log_err("malloc failure in lookup_parent_glue"); + lock_rw_unlock(&akey->entry.lock); + } + } + /* see if new (but lame) addresses have become available */ + return delegpt_count_targets(dp) != num; +} + +int +iter_get_next_root(struct iter_hints* hints, struct iter_forwards* fwd, + uint16_t* c) +{ + uint16_t c1 = *c, c2 = *c; + int r1 = hints_next_root(hints, &c1); + int r2 = forwards_next_root(fwd, &c2); + if(!r1 && !r2) /* got none, end of list */ + return 0; + else if(!r1) /* got one, return that */ + *c = c2; + else if(!r2) + *c = c1; + else if(c1 < c2) /* got both take smallest */ + *c = c1; + else *c = c2; + return 1; +} + +void +iter_scrub_ds(struct dns_msg* msg, struct ub_packed_rrset_key* ns, uint8_t* z) +{ + /* Only the DS record for the delegation itself is expected. + * We allow DS for everything between the bailiwick and the + * zonecut, thus DS records must be at or above the zonecut. + * And the DS records must be below the server authority zone. + * The answer section is already scrubbed. */ + size_t i = msg->rep->an_numrrsets; + while(i < (msg->rep->an_numrrsets + msg->rep->ns_numrrsets)) { + struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; + if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS && + (!ns || !dname_subdomain_c(ns->rk.dname, s->rk.dname) + || query_dname_compare(z, s->rk.dname) == 0)) { + log_nametypeclass(VERB_ALGO, "removing irrelevant DS", + s->rk.dname, ntohs(s->rk.type), + ntohs(s->rk.rrset_class)); + memmove(msg->rep->rrsets+i, msg->rep->rrsets+i+1, + sizeof(struct ub_packed_rrset_key*) * + (msg->rep->rrset_count-i-1)); + msg->rep->ns_numrrsets--; + msg->rep->rrset_count--; + /* stay at same i, but new record */ + continue; + } + i++; + } +} + +void iter_dec_attempts(struct delegpt* dp, int d) +{ + struct delegpt_addr* a; + for(a=dp->target_list; a; a = a->next_target) { + if(a->attempts >= OUTBOUND_MSG_RETRY) { + /* add back to result list */ + a->next_result = dp->result_list; + dp->result_list = a; + } + if(a->attempts > d) + a->attempts -= d; + else a->attempts = 0; + } +} + +void iter_merge_retry_counts(struct delegpt* dp, struct delegpt* old) +{ + struct delegpt_addr* a, *o, *prev; + for(a=dp->target_list; a; a = a->next_target) { + o = delegpt_find_addr(old, &a->addr, a->addrlen); + if(o) { + log_addr(VERB_ALGO, "copy attempt count previous dp", + &a->addr, a->addrlen); + a->attempts = o->attempts; + } + } + prev = NULL; + a = dp->usable_list; + while(a) { + if(a->attempts >= OUTBOUND_MSG_RETRY) { + log_addr(VERB_ALGO, "remove from usable list dp", + &a->addr, a->addrlen); + /* remove from result list */ + if(prev) + prev->next_usable = a->next_usable; + else dp->usable_list = a->next_usable; + /* prev stays the same */ + a = a->next_usable; + continue; + } + prev = a; + a = a->next_usable; + } +} + +int +iter_ds_toolow(struct dns_msg* msg, struct delegpt* dp) +{ + /* if for query example.com, there is example.com SOA or a subdomain + * of example.com, then we are too low and need to fetch NS. */ + size_t i; + /* if we have a DNAME or CNAME we are probably wrong */ + /* if we have a qtype DS in the answer section, its fine */ + for(i=0; i < msg->rep->an_numrrsets; i++) { + struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; + if(ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME || + ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME) { + /* not the right answer, maybe too low, check the + * RRSIG signer name (if there is any) for a hint + * that it is from the dp zone anyway */ + uint8_t* sname; + size_t slen; + val_find_rrset_signer(s, &sname, &slen); + if(sname && query_dname_compare(dp->name, sname)==0) + return 0; /* it is fine, from the right dp */ + return 1; + } + if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS) + return 0; /* fine, we have a DS record */ + } + for(i=msg->rep->an_numrrsets; + i < msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) { + struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; + if(ntohs(s->rk.type) == LDNS_RR_TYPE_SOA) { + if(dname_subdomain_c(s->rk.dname, msg->qinfo.qname)) + return 1; /* point is too low */ + if(query_dname_compare(s->rk.dname, dp->name)==0) + return 0; /* right dp */ + } + if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC || + ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) { + uint8_t* sname; + size_t slen; + val_find_rrset_signer(s, &sname, &slen); + if(sname && query_dname_compare(dp->name, sname)==0) + return 0; /* it is fine, from the right dp */ + return 1; + } + } + /* we do not know */ + return 1; +} + +int iter_dp_cangodown(struct query_info* qinfo, struct delegpt* dp) +{ + /* no delegation point, do not see how we can go down, + * robust check, it should really exist */ + if(!dp) return 0; + + /* see if dp equals the qname, then we cannot go down further */ + if(query_dname_compare(qinfo->qname, dp->name) == 0) + return 0; + /* if dp is one label above the name we also cannot go down further */ + if(dname_count_labels(qinfo->qname) == dp->namelabs+1) + return 0; + return 1; +} diff --git a/external/unbound/iterator/iter_utils.h b/external/unbound/iterator/iter_utils.h new file mode 100644 index 000000000..abdc68f3c --- /dev/null +++ b/external/unbound/iterator/iter_utils.h @@ -0,0 +1,338 @@ +/* + * iterator/iter_utils.h - iterative resolver module utility functions. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file contains functions to assist the iterator module. + * Configuration options. Forward zones. + */ + +#ifndef ITERATOR_ITER_UTILS_H +#define ITERATOR_ITER_UTILS_H +#include "iterator/iter_resptype.h" +struct sldns_buffer; +struct iter_env; +struct iter_hints; +struct iter_forwards; +struct config_file; +struct module_env; +struct delegpt_addr; +struct delegpt; +struct regional; +struct msg_parse; +struct ub_randstate; +struct query_info; +struct reply_info; +struct module_qstate; +struct sock_list; +struct ub_packed_rrset_key; + +/** + * Process config options and set iterator module state. + * Sets default values if no config is found. + * @param iter_env: iterator module state. + * @param cfg: config options. + * @return 0 on error. + */ +int iter_apply_cfg(struct iter_env* iter_env, struct config_file* cfg); + +/** + * Select a valid, nice target to send query to. + * Sorting and removing unsuitable targets is combined. + * + * @param iter_env: iterator module global state, with ip6 enabled and + * do-not-query-addresses. + * @param env: environment with infra cache (lameness, rtt info). + * @param dp: delegation point with result list. + * @param name: zone name (for lameness check). + * @param namelen: length of name. + * @param qtype: query type that we want to send. + * @param dnssec_lame: set to 1, if a known dnssec-lame server is selected + * these are not preferred, but are used as a last resort. + * @param chase_to_rd: set to 1 if a known recursion lame server is selected + * these are not preferred, but are used as a last resort. + * @param open_target: number of currently outstanding target queries. + * If we wait for these, perhaps more server addresses become available. + * @param blacklist: the IP blacklist to use. + * @return best target or NULL if no target. + * if not null, that target is removed from the result list in the dp. + */ +struct delegpt_addr* iter_server_selection(struct iter_env* iter_env, + struct module_env* env, struct delegpt* dp, uint8_t* name, + size_t namelen, uint16_t qtype, int* dnssec_lame, + int* chase_to_rd, int open_target, struct sock_list* blacklist); + +/** + * Allocate dns_msg from parsed msg, in regional. + * @param pkt: packet. + * @param msg: parsed message (cleaned and ready for regional allocation). + * @param regional: regional to use for allocation. + * @return newly allocated dns_msg, or NULL on memory error. + */ +struct dns_msg* dns_alloc_msg(struct sldns_buffer* pkt, struct msg_parse* msg, + struct regional* regional); + +/** + * Copy a dns_msg to this regional. + * @param from: dns message, also in regional. + * @param regional: regional to use for allocation. + * @return newly allocated dns_msg, or NULL on memory error. + */ +struct dns_msg* dns_copy_msg(struct dns_msg* from, struct regional* regional); + +/** + * Allocate a dns_msg with malloc/alloc structure and store in dns cache. + * @param env: environment, with alloc structure and dns cache. + * @param qinf: query info, the query for which answer is stored. + * @param rep: reply in dns_msg from dns_alloc_msg for example. + * @param is_referral: If true, then the given message to be stored is a + * referral. The cache implementation may use this as a hint. + * @param leeway: prefetch TTL leeway to expire old rrsets quicker. + * @param pside: true if dp is parentside, thus message is 'fresh' and NS + * can be prefetch-updates. + * @param region: to copy modified (cache is better) rrs back to. + * @return void, because we are not interested in alloc errors, + * the iterator and validator can operate on the results in their + * scratch space (the qstate.region) and are not dependent on the cache. + * It is useful to log the alloc failure (for the server operator), + * but the query resolution can continue without cache storage. + */ +void iter_dns_store(struct module_env* env, struct query_info* qinf, + struct reply_info* rep, int is_referral, time_t leeway, int pside, + struct regional* region); + +/** + * Select randomly with n/m probability. + * For shuffle NS records for address fetching. + * @param rnd: random table + * @param n: probability. + * @param m: divisor for probability. + * @return true with n/m probability. + */ +int iter_ns_probability(struct ub_randstate* rnd, int n, int m); + +/** + * Mark targets that result in a dependency cycle as done, so they + * will not get selected as targets. + * @param qstate: query state. + * @param dp: delegpt to mark ns in. + */ +void iter_mark_cycle_targets(struct module_qstate* qstate, struct delegpt* dp); + +/** + * Mark targets that result in a dependency cycle as done, so they + * will not get selected as targets. For the parent-side lookups. + * @param qstate: query state. + * @param dp: delegpt to mark ns in. + */ +void iter_mark_pside_cycle_targets(struct module_qstate* qstate, + struct delegpt* dp); + +/** + * See if delegation is useful or offers immediately no targets for + * further recursion. + * @param qinfo: query name and type + * @param qflags: query flags with RD flag + * @param dp: delegpt to check. + * @return true if dp is useless. + */ +int iter_dp_is_useless(struct query_info* qinfo, uint16_t qflags, + struct delegpt* dp); + +/** + * See if delegation is expected to have DNSSEC information (RRSIGs) in + * its answers, or not. Inspects delegation point (name), trust anchors, + * and delegation message (DS RRset) to determine this. + * @param env: module env with trust anchors. + * @param dp: delegation point. + * @param msg: delegation message, with DS if a secure referral. + * @param dclass: class of query. + * @return 1 if dnssec is expected, 0 if not. + */ +int iter_indicates_dnssec(struct module_env* env, struct delegpt* dp, + struct dns_msg* msg, uint16_t dclass); + +/** + * See if a message contains DNSSEC. + * This is examined by looking for RRSIGs. With DNSSEC a valid answer, + * nxdomain, nodata, referral or cname reply has RRSIGs in answer or auth + * sections, sigs on answer data, SOA, DS, or NSEC/NSEC3 records. + * @param msg: message to examine. + * @return true if DNSSEC information was found. + */ +int iter_msg_has_dnssec(struct dns_msg* msg); + +/** + * See if a message is known to be from a certain zone. + * This looks for SOA or NS rrsets, for answers. + * For referrals, when one label is delegated, the zone is detected. + * Does not look at signatures. + * @param msg: the message to inspect. + * @param dp: delegation point with zone name to look for. + * @param type: type of message. + * @param dclass: class of query. + * @return true if message is certain to be from zone in dp->name. + * false if not sure (empty msg), or not from the zone. + */ +int iter_msg_from_zone(struct dns_msg* msg, struct delegpt* dp, + enum response_type type, uint16_t dclass); + +/** + * Check if two replies are equal + * For fallback procedures + * @param p: reply one. The reply has rrset data pointers in region. + * Does not check rrset-IDs + * @param q: reply two + * @param region: scratch buffer. + * @return if one and two are equal. + */ +int reply_equal(struct reply_info* p, struct reply_info* q, struct regional* region); + +/** + * Store parent-side rrset in seperate rrset cache entries for later + * last-resort * lookups in case the child-side versions of this information + * fails. + * @param env: environment with cache, time, ... + * @param rrset: the rrset to store (copied). + * Failure to store is logged, but otherwise ignored. + */ +void iter_store_parentside_rrset(struct module_env* env, + struct ub_packed_rrset_key* rrset); + +/** + * Store parent-side NS records from a referral message + * @param env: environment with cache, time, ... + * @param rep: response with NS rrset. + * Failure to store is logged, but otherwise ignored. + */ +void iter_store_parentside_NS(struct module_env* env, struct reply_info* rep); + +/** + * Store parent-side negative element, the parentside rrset does not exist, + * creates an rrset with empty rdata in the rrset cache with PARENTSIDE flag. + * @param env: environment with cache, time, ... + * @param qinfo: the identity of the rrset that is missing. + * @param rep: delegation response or answer response, to glean TTL from. + * (malloc) failure is logged but otherwise ignored. + */ +void iter_store_parentside_neg(struct module_env* env, + struct query_info* qinfo, struct reply_info* rep); + +/** + * Add parent NS record if that exists in the cache. This is both new + * information and acts like a timeout throttle on retries. + * @param env: query env with rrset cache and time. + * @param dp: delegation point to store result in. Also this dp is used to + * see which NS name is needed. + * @param region: region to alloc result in. + * @param qinfo: pertinent information, the qclass. + * @return false on malloc failure. + * if true, the routine worked and if such cached information + * existed dp->has_parent_side_NS is set true. + */ +int iter_lookup_parent_NS_from_cache(struct module_env* env, + struct delegpt* dp, struct regional* region, struct query_info* qinfo); + +/** + * Add parent-side glue if that exists in the cache. This is both new + * information and acts like a timeout throttle on retries to fetch them. + * @param env: query env with rrset cache and time. + * @param dp: delegation point to store result in. Also this dp is used to + * see which NS name is needed. + * @param region: region to alloc result in. + * @param qinfo: pertinent information, the qclass. + * @return: true, it worked, no malloc failures, and new addresses (lame) + * have been added, giving extra options as query targets. + */ +int iter_lookup_parent_glue_from_cache(struct module_env* env, + struct delegpt* dp, struct regional* region, struct query_info* qinfo); + +/** + * Lookup next root-hint or root-forward entry. + * @param hints: the hints. + * @param fwd: the forwards. + * @param c: the class to start searching at. 0 means find first one. + * @return false if no classes found, true if found and returned in c. + */ +int iter_get_next_root(struct iter_hints* hints, struct iter_forwards* fwd, + uint16_t* c); + +/** + * Remove DS records that are inappropriate before they are cached. + * @param msg: the response to scrub. + * @param ns: RRSET that is the NS record for the referral. + * if NULL, then all DS records are removed from the authority section. + * @param z: zone name that the response is from. + */ +void iter_scrub_ds(struct dns_msg* msg, struct ub_packed_rrset_key* ns, + uint8_t* z); + +/** + * Remove query attempts from all available ips. For 0x20. + * @param dp: delegpt. + * @param d: decrease. + */ +void iter_dec_attempts(struct delegpt* dp, int d); + +/** + * Add retry counts from older delegpt to newer delegpt. + * Does not waste time on timeout'd (or other failing) addresses. + * @param dp: new delegationpoint. + * @param old: old delegationpoint. + */ +void iter_merge_retry_counts(struct delegpt* dp, struct delegpt* old); + +/** + * See if a DS response (type ANSWER) is too low: a nodata answer with + * a SOA record in the authority section at-or-below the qchase.qname. + * Also returns true if we are not sure (i.e. empty message, CNAME nosig). + * @param msg: the response. + * @param dp: the dp name is used to check if the RRSIG gives a clue that + * it was originated from the correct nameserver. + * @return true if too low. + */ +int iter_ds_toolow(struct dns_msg* msg, struct delegpt* dp); + +/** + * See if delegpt can go down a step to the qname or not + * @param qinfo: the query name looked up. + * @param dp: checked if the name can go lower to the qname + * @return true if can go down, false if that would not be possible. + * the current response seems to be the one and only, best possible, response. + */ +int iter_dp_cangodown(struct query_info* qinfo, struct delegpt* dp); + +#endif /* ITERATOR_ITER_UTILS_H */ diff --git a/external/unbound/iterator/iterator.c b/external/unbound/iterator/iterator.c new file mode 100644 index 000000000..df5f645cc --- /dev/null +++ b/external/unbound/iterator/iterator.c @@ -0,0 +1,2996 @@ +/* + * iterator/iterator.c - iterative resolver DNS query response module + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file contains a module that performs recusive iterative DNS query + * processing. + */ + +#include "config.h" +#include "iterator/iterator.h" +#include "iterator/iter_utils.h" +#include "iterator/iter_hints.h" +#include "iterator/iter_fwd.h" +#include "iterator/iter_donotq.h" +#include "iterator/iter_delegpt.h" +#include "iterator/iter_resptype.h" +#include "iterator/iter_scrub.h" +#include "iterator/iter_priv.h" +#include "validator/val_neg.h" +#include "services/cache/dns.h" +#include "services/cache/infra.h" +#include "util/module.h" +#include "util/netevent.h" +#include "util/net_help.h" +#include "util/regional.h" +#include "util/data/dname.h" +#include "util/data/msgencode.h" +#include "util/fptr_wlist.h" +#include "util/config_file.h" +#include "ldns/rrdef.h" +#include "ldns/wire2str.h" +#include "ldns/parseutil.h" +#include "ldns/sbuffer.h" + +int +iter_init(struct module_env* env, int id) +{ + struct iter_env* iter_env = (struct iter_env*)calloc(1, + sizeof(struct iter_env)); + if(!iter_env) { + log_err("malloc failure"); + return 0; + } + env->modinfo[id] = (void*)iter_env; + if(!iter_apply_cfg(iter_env, env->cfg)) { + log_err("iterator: could not apply configuration settings."); + return 0; + } + return 1; +} + +void +iter_deinit(struct module_env* env, int id) +{ + struct iter_env* iter_env; + if(!env || !env->modinfo[id]) + return; + iter_env = (struct iter_env*)env->modinfo[id]; + free(iter_env->target_fetch_policy); + priv_delete(iter_env->priv); + donotq_delete(iter_env->donotq); + free(iter_env); + env->modinfo[id] = NULL; +} + +/** new query for iterator */ +static int +iter_new(struct module_qstate* qstate, int id) +{ + struct iter_qstate* iq = (struct iter_qstate*)regional_alloc( + qstate->region, sizeof(struct iter_qstate)); + qstate->minfo[id] = iq; + if(!iq) + return 0; + memset(iq, 0, sizeof(*iq)); + iq->state = INIT_REQUEST_STATE; + iq->final_state = FINISHED_STATE; + iq->an_prepend_list = NULL; + iq->an_prepend_last = NULL; + iq->ns_prepend_list = NULL; + iq->ns_prepend_last = NULL; + iq->dp = NULL; + iq->depth = 0; + iq->num_target_queries = 0; + iq->num_current_queries = 0; + iq->query_restart_count = 0; + iq->referral_count = 0; + iq->sent_count = 0; + iq->wait_priming_stub = 0; + iq->refetch_glue = 0; + iq->dnssec_expected = 0; + iq->dnssec_lame_query = 0; + iq->chase_flags = qstate->query_flags; + /* Start with the (current) qname. */ + iq->qchase = qstate->qinfo; + outbound_list_init(&iq->outlist); + return 1; +} + +/** + * Transition to the next state. This can be used to advance a currently + * processing event. It cannot be used to reactivate a forEvent. + * + * @param iq: iterator query state + * @param nextstate The state to transition to. + * @return true. This is so this can be called as the return value for the + * actual process*State() methods. (Transitioning to the next state + * implies further processing). + */ +static int +next_state(struct iter_qstate* iq, enum iter_state nextstate) +{ + /* If transitioning to a "response" state, make sure that there is a + * response */ + if(iter_state_is_responsestate(nextstate)) { + if(iq->response == NULL) { + log_err("transitioning to response state sans " + "response."); + } + } + iq->state = nextstate; + return 1; +} + +/** + * Transition an event to its final state. Final states always either return + * a result up the module chain, or reactivate a dependent event. Which + * final state to transtion to is set in the module state for the event when + * it was created, and depends on the original purpose of the event. + * + * The response is stored in the qstate->buf buffer. + * + * @param iq: iterator query state + * @return false. This is so this method can be used as the return value for + * the processState methods. (Transitioning to the final state + */ +static int +final_state(struct iter_qstate* iq) +{ + return next_state(iq, iq->final_state); +} + +/** + * Callback routine to handle errors in parent query states + * @param qstate: query state that failed. + * @param id: module id. + * @param super: super state. + */ +static void +error_supers(struct module_qstate* qstate, int id, struct module_qstate* super) +{ + struct iter_qstate* super_iq = (struct iter_qstate*)super->minfo[id]; + + if(qstate->qinfo.qtype == LDNS_RR_TYPE_A || + qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) { + /* mark address as failed. */ + struct delegpt_ns* dpns = NULL; + if(super_iq->dp) + dpns = delegpt_find_ns(super_iq->dp, + qstate->qinfo.qname, qstate->qinfo.qname_len); + if(!dpns) { + /* not interested */ + verbose(VERB_ALGO, "subq error, but not interested"); + log_query_info(VERB_ALGO, "superq", &super->qinfo); + if(super_iq->dp) + delegpt_log(VERB_ALGO, super_iq->dp); + log_assert(0); + return; + } else { + /* see if the failure did get (parent-lame) info */ + if(!cache_fill_missing(super->env, + super_iq->qchase.qclass, super->region, + super_iq->dp)) + log_err("out of memory adding missing"); + } + dpns->resolved = 1; /* mark as failed */ + super_iq->num_target_queries--; + } + if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS) { + /* prime failed to get delegation */ + super_iq->dp = NULL; + } + /* evaluate targets again */ + super_iq->state = QUERYTARGETS_STATE; + /* super becomes runnable, and will process this change */ +} + +/** + * Return an error to the client + * @param qstate: our query state + * @param id: module id + * @param rcode: error code (DNS errcode). + * @return: 0 for use by caller, to make notation easy, like: + * return error_response(..). + */ +static int +error_response(struct module_qstate* qstate, int id, int rcode) +{ + verbose(VERB_QUERY, "return error response %s", + sldns_lookup_by_id(sldns_rcodes, rcode)? + sldns_lookup_by_id(sldns_rcodes, rcode)->name:"??"); + qstate->return_rcode = rcode; + qstate->return_msg = NULL; + qstate->ext_state[id] = module_finished; + return 0; +} + +/** + * Return an error to the client and cache the error code in the + * message cache (so per qname, qtype, qclass). + * @param qstate: our query state + * @param id: module id + * @param rcode: error code (DNS errcode). + * @return: 0 for use by caller, to make notation easy, like: + * return error_response(..). + */ +static int +error_response_cache(struct module_qstate* qstate, int id, int rcode) +{ + /* store in cache */ + struct reply_info err; + if(qstate->prefetch_leeway > NORR_TTL) { + verbose(VERB_ALGO, "error response for prefetch in cache"); + /* attempt to adjust the cache entry prefetch */ + if(dns_cache_prefetch_adjust(qstate->env, &qstate->qinfo, + NORR_TTL)) + return error_response(qstate, id, rcode); + /* if that fails (not in cache), fall through to store err */ + } + memset(&err, 0, sizeof(err)); + err.flags = (uint16_t)(BIT_QR | BIT_RA); + FLAGS_SET_RCODE(err.flags, rcode); + err.qdcount = 1; + err.ttl = NORR_TTL; + err.prefetch_ttl = PREFETCH_TTL_CALC(err.ttl); + /* do not waste time trying to validate this servfail */ + err.security = sec_status_indeterminate; + verbose(VERB_ALGO, "store error response in message cache"); + iter_dns_store(qstate->env, &qstate->qinfo, &err, 0, 0, 0, NULL); + return error_response(qstate, id, rcode); +} + +/** check if prepend item is duplicate item */ +static int +prepend_is_duplicate(struct ub_packed_rrset_key** sets, size_t to, + struct ub_packed_rrset_key* dup) +{ + size_t i; + for(i=0; i<to; i++) { + if(sets[i]->rk.type == dup->rk.type && + sets[i]->rk.rrset_class == dup->rk.rrset_class && + sets[i]->rk.dname_len == dup->rk.dname_len && + query_dname_compare(sets[i]->rk.dname, dup->rk.dname) + == 0) + return 1; + } + return 0; +} + +/** prepend the prepend list in the answer and authority section of dns_msg */ +static int +iter_prepend(struct iter_qstate* iq, struct dns_msg* msg, + struct regional* region) +{ + struct iter_prep_list* p; + struct ub_packed_rrset_key** sets; + size_t num_an = 0, num_ns = 0;; + for(p = iq->an_prepend_list; p; p = p->next) + num_an++; + for(p = iq->ns_prepend_list; p; p = p->next) + num_ns++; + if(num_an + num_ns == 0) + return 1; + verbose(VERB_ALGO, "prepending %d rrsets", (int)num_an + (int)num_ns); + sets = regional_alloc(region, (num_an+num_ns+msg->rep->rrset_count) * + sizeof(struct ub_packed_rrset_key*)); + if(!sets) + return 0; + /* ANSWER section */ + num_an = 0; + for(p = iq->an_prepend_list; p; p = p->next) { + sets[num_an++] = p->rrset; + } + memcpy(sets+num_an, msg->rep->rrsets, msg->rep->an_numrrsets * + sizeof(struct ub_packed_rrset_key*)); + /* AUTH section */ + num_ns = 0; + for(p = iq->ns_prepend_list; p; p = p->next) { + if(prepend_is_duplicate(sets+msg->rep->an_numrrsets+num_an, + num_ns, p->rrset) || prepend_is_duplicate( + msg->rep->rrsets+msg->rep->an_numrrsets, + msg->rep->ns_numrrsets, p->rrset)) + continue; + sets[msg->rep->an_numrrsets + num_an + num_ns++] = p->rrset; + } + memcpy(sets + num_an + msg->rep->an_numrrsets + num_ns, + msg->rep->rrsets + msg->rep->an_numrrsets, + (msg->rep->ns_numrrsets + msg->rep->ar_numrrsets) * + sizeof(struct ub_packed_rrset_key*)); + + /* NXDOMAIN rcode can stay if we prepended DNAME/CNAMEs, because + * this is what recursors should give. */ + msg->rep->rrset_count += num_an + num_ns; + msg->rep->an_numrrsets += num_an; + msg->rep->ns_numrrsets += num_ns; + msg->rep->rrsets = sets; + return 1; +} + +/** + * Add rrset to ANSWER prepend list + * @param qstate: query state. + * @param iq: iterator query state. + * @param rrset: rrset to add. + * @return false on failure (malloc). + */ +static int +iter_add_prepend_answer(struct module_qstate* qstate, struct iter_qstate* iq, + struct ub_packed_rrset_key* rrset) +{ + struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc( + qstate->region, sizeof(struct iter_prep_list)); + if(!p) + return 0; + p->rrset = rrset; + p->next = NULL; + /* add at end */ + if(iq->an_prepend_last) + iq->an_prepend_last->next = p; + else iq->an_prepend_list = p; + iq->an_prepend_last = p; + return 1; +} + +/** + * Add rrset to AUTHORITY prepend list + * @param qstate: query state. + * @param iq: iterator query state. + * @param rrset: rrset to add. + * @return false on failure (malloc). + */ +static int +iter_add_prepend_auth(struct module_qstate* qstate, struct iter_qstate* iq, + struct ub_packed_rrset_key* rrset) +{ + struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc( + qstate->region, sizeof(struct iter_prep_list)); + if(!p) + return 0; + p->rrset = rrset; + p->next = NULL; + /* add at end */ + if(iq->ns_prepend_last) + iq->ns_prepend_last->next = p; + else iq->ns_prepend_list = p; + iq->ns_prepend_last = p; + return 1; +} + +/** + * Given a CNAME response (defined as a response containing a CNAME or DNAME + * that does not answer the request), process the response, modifying the + * state as necessary. This follows the CNAME/DNAME chain and returns the + * final query name. + * + * sets the new query name, after following the CNAME/DNAME chain. + * @param qstate: query state. + * @param iq: iterator query state. + * @param msg: the response. + * @param mname: returned target new query name. + * @param mname_len: length of mname. + * @return false on (malloc) error. + */ +static int +handle_cname_response(struct module_qstate* qstate, struct iter_qstate* iq, + struct dns_msg* msg, uint8_t** mname, size_t* mname_len) +{ + size_t i; + /* Start with the (current) qname. */ + *mname = iq->qchase.qname; + *mname_len = iq->qchase.qname_len; + + /* Iterate over the ANSWER rrsets in order, looking for CNAMEs and + * DNAMES. */ + for(i=0; i<msg->rep->an_numrrsets; i++) { + struct ub_packed_rrset_key* r = msg->rep->rrsets[i]; + /* If there is a (relevant) DNAME, add it to the list. + * We always expect there to be CNAME that was generated + * by this DNAME following, so we don't process the DNAME + * directly. */ + if(ntohs(r->rk.type) == LDNS_RR_TYPE_DNAME && + dname_strict_subdomain_c(*mname, r->rk.dname)) { + if(!iter_add_prepend_answer(qstate, iq, r)) + return 0; + continue; + } + + if(ntohs(r->rk.type) == LDNS_RR_TYPE_CNAME && + query_dname_compare(*mname, r->rk.dname) == 0) { + /* Add this relevant CNAME rrset to the prepend list.*/ + if(!iter_add_prepend_answer(qstate, iq, r)) + return 0; + get_cname_target(r, mname, mname_len); + } + + /* Other rrsets in the section are ignored. */ + } + /* add authority rrsets to authority prepend, for wildcarded CNAMEs */ + for(i=msg->rep->an_numrrsets; i<msg->rep->an_numrrsets + + msg->rep->ns_numrrsets; i++) { + struct ub_packed_rrset_key* r = msg->rep->rrsets[i]; + /* only add NSEC/NSEC3, as they may be needed for validation */ + if(ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC || + ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC3) { + if(!iter_add_prepend_auth(qstate, iq, r)) + return 0; + } + } + return 1; +} + +/** + * Generate a subrequest. + * Generate a local request event. Local events are tied to this module, and + * have a correponding (first tier) event that is waiting for this event to + * resolve to continue. + * + * @param qname The query name for this request. + * @param qnamelen length of qname + * @param qtype The query type for this request. + * @param qclass The query class for this request. + * @param qstate The event that is generating this event. + * @param id: module id. + * @param iq: The iterator state that is generating this event. + * @param initial_state The initial response state (normally this + * is QUERY_RESP_STATE, unless it is known that the request won't + * need iterative processing + * @param finalstate The final state for the response to this request. + * @param subq_ret: if newly allocated, the subquerystate, or NULL if it does + * not need initialisation. + * @param v: if true, validation is done on the subquery. + * @return false on error (malloc). + */ +static int +generate_sub_request(uint8_t* qname, size_t qnamelen, uint16_t qtype, + uint16_t qclass, struct module_qstate* qstate, int id, + struct iter_qstate* iq, enum iter_state initial_state, + enum iter_state finalstate, struct module_qstate** subq_ret, int v) +{ + struct module_qstate* subq = NULL; + struct iter_qstate* subiq = NULL; + uint16_t qflags = 0; /* OPCODE QUERY, no flags */ + struct query_info qinf; + int prime = (finalstate == PRIME_RESP_STATE)?1:0; + qinf.qname = qname; + qinf.qname_len = qnamelen; + qinf.qtype = qtype; + qinf.qclass = qclass; + + /* RD should be set only when sending the query back through the INIT + * state. */ + if(initial_state == INIT_REQUEST_STATE) + qflags |= BIT_RD; + /* We set the CD flag so we can send this through the "head" of + * the resolution chain, which might have a validator. We are + * uninterested in validating things not on the direct resolution + * path. */ + if(!v) + qflags |= BIT_CD; + + /* attach subquery, lookup existing or make a new one */ + fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub)); + if(!(*qstate->env->attach_sub)(qstate, &qinf, qflags, prime, &subq)) { + return 0; + } + *subq_ret = subq; + if(subq) { + /* initialise the new subquery */ + subq->curmod = id; + subq->ext_state[id] = module_state_initial; + subq->minfo[id] = regional_alloc(subq->region, + sizeof(struct iter_qstate)); + if(!subq->minfo[id]) { + log_err("init subq: out of memory"); + fptr_ok(fptr_whitelist_modenv_kill_sub( + qstate->env->kill_sub)); + (*qstate->env->kill_sub)(subq); + return 0; + } + subiq = (struct iter_qstate*)subq->minfo[id]; + memset(subiq, 0, sizeof(*subiq)); + subiq->num_target_queries = 0; + subiq->num_current_queries = 0; + subiq->depth = iq->depth+1; + outbound_list_init(&subiq->outlist); + subiq->state = initial_state; + subiq->final_state = finalstate; + subiq->qchase = subq->qinfo; + subiq->chase_flags = subq->query_flags; + subiq->refetch_glue = 0; + } + return 1; +} + +/** + * Generate and send a root priming request. + * @param qstate: the qtstate that triggered the need to prime. + * @param iq: iterator query state. + * @param id: module id. + * @param qclass: the class to prime. + * @return 0 on failure + */ +static int +prime_root(struct module_qstate* qstate, struct iter_qstate* iq, int id, + uint16_t qclass) +{ + struct delegpt* dp; + struct module_qstate* subq; + verbose(VERB_DETAIL, "priming . %s NS", + sldns_lookup_by_id(sldns_rr_classes, (int)qclass)? + sldns_lookup_by_id(sldns_rr_classes, (int)qclass)->name:"??"); + dp = hints_lookup_root(qstate->env->hints, qclass); + if(!dp) { + verbose(VERB_ALGO, "Cannot prime due to lack of hints"); + return 0; + } + /* Priming requests start at the QUERYTARGETS state, skipping + * the normal INIT state logic (which would cause an infloop). */ + if(!generate_sub_request((uint8_t*)"\000", 1, LDNS_RR_TYPE_NS, + qclass, qstate, id, iq, QUERYTARGETS_STATE, PRIME_RESP_STATE, + &subq, 0)) { + verbose(VERB_ALGO, "could not prime root"); + return 0; + } + if(subq) { + struct iter_qstate* subiq = + (struct iter_qstate*)subq->minfo[id]; + /* Set the initial delegation point to the hint. + * copy dp, it is now part of the root prime query. + * dp was part of in the fixed hints structure. */ + subiq->dp = delegpt_copy(dp, subq->region); + if(!subiq->dp) { + log_err("out of memory priming root, copydp"); + fptr_ok(fptr_whitelist_modenv_kill_sub( + qstate->env->kill_sub)); + (*qstate->env->kill_sub)(subq); + return 0; + } + /* there should not be any target queries. */ + subiq->num_target_queries = 0; + subiq->dnssec_expected = iter_indicates_dnssec( + qstate->env, subiq->dp, NULL, subq->qinfo.qclass); + } + + /* this module stops, our submodule starts, and does the query. */ + qstate->ext_state[id] = module_wait_subquery; + return 1; +} + +/** + * Generate and process a stub priming request. This method tests for the + * need to prime a stub zone, so it is safe to call for every request. + * + * @param qstate: the qtstate that triggered the need to prime. + * @param iq: iterator query state. + * @param id: module id. + * @param qname: request name. + * @param qclass: request class. + * @return true if a priming subrequest was made, false if not. The will only + * issue a priming request if it detects an unprimed stub. + * Uses value of 2 to signal during stub-prime in root-prime situation + * that a noprime-stub is available and resolution can continue. + */ +static int +prime_stub(struct module_qstate* qstate, struct iter_qstate* iq, int id, + uint8_t* qname, uint16_t qclass) +{ + /* Lookup the stub hint. This will return null if the stub doesn't + * need to be re-primed. */ + struct iter_hints_stub* stub; + struct delegpt* stub_dp; + struct module_qstate* subq; + + if(!qname) return 0; + stub = hints_lookup_stub(qstate->env->hints, qname, qclass, iq->dp); + /* The stub (if there is one) does not need priming. */ + if(!stub) + return 0; + stub_dp = stub->dp; + + /* is it a noprime stub (always use) */ + if(stub->noprime) { + int r = 0; + if(iq->dp == NULL) r = 2; + /* copy the dp out of the fixed hints structure, so that + * it can be changed when servicing this query */ + iq->dp = delegpt_copy(stub_dp, qstate->region); + if(!iq->dp) { + log_err("out of memory priming stub"); + (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); + return 1; /* return 1 to make module stop, with error */ + } + log_nametypeclass(VERB_DETAIL, "use stub", stub_dp->name, + LDNS_RR_TYPE_NS, qclass); + return r; + } + + /* Otherwise, we need to (re)prime the stub. */ + log_nametypeclass(VERB_DETAIL, "priming stub", stub_dp->name, + LDNS_RR_TYPE_NS, qclass); + + /* Stub priming events start at the QUERYTARGETS state to avoid the + * redundant INIT state processing. */ + if(!generate_sub_request(stub_dp->name, stub_dp->namelen, + LDNS_RR_TYPE_NS, qclass, qstate, id, iq, + QUERYTARGETS_STATE, PRIME_RESP_STATE, &subq, 0)) { + verbose(VERB_ALGO, "could not prime stub"); + (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); + return 1; /* return 1 to make module stop, with error */ + } + if(subq) { + struct iter_qstate* subiq = + (struct iter_qstate*)subq->minfo[id]; + + /* Set the initial delegation point to the hint. */ + /* make copy to avoid use of stub dp by different qs/threads */ + subiq->dp = delegpt_copy(stub_dp, subq->region); + if(!subiq->dp) { + log_err("out of memory priming stub, copydp"); + fptr_ok(fptr_whitelist_modenv_kill_sub( + qstate->env->kill_sub)); + (*qstate->env->kill_sub)(subq); + (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); + return 1; /* return 1 to make module stop, with error */ + } + /* there should not be any target queries -- although there + * wouldn't be anyway, since stub hints never have + * missing targets. */ + subiq->num_target_queries = 0; + subiq->wait_priming_stub = 1; + subiq->dnssec_expected = iter_indicates_dnssec( + qstate->env, subiq->dp, NULL, subq->qinfo.qclass); + } + + /* this module stops, our submodule starts, and does the query. */ + qstate->ext_state[id] = module_wait_subquery; + return 1; +} + +/** + * Generate A and AAAA checks for glue that is in-zone for the referral + * we just got to obtain authoritative information on the adresses. + * + * @param qstate: the qtstate that triggered the need to prime. + * @param iq: iterator query state. + * @param id: module id. + */ +static void +generate_a_aaaa_check(struct module_qstate* qstate, struct iter_qstate* iq, + int id) +{ + struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; + struct module_qstate* subq; + size_t i; + struct reply_info* rep = iq->response->rep; + struct ub_packed_rrset_key* s; + log_assert(iq->dp); + + if(iq->depth == ie->max_dependency_depth) + return; + /* walk through additional, and check if in-zone, + * only relevant A, AAAA are left after scrub anyway */ + for(i=rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) { + s = rep->rrsets[i]; + /* check *ALL* addresses that are transmitted in additional*/ + /* is it an address ? */ + if( !(ntohs(s->rk.type)==LDNS_RR_TYPE_A || + ntohs(s->rk.type)==LDNS_RR_TYPE_AAAA)) { + continue; + } + /* is this query the same as the A/AAAA check for it */ + if(qstate->qinfo.qtype == ntohs(s->rk.type) && + qstate->qinfo.qclass == ntohs(s->rk.rrset_class) && + query_dname_compare(qstate->qinfo.qname, + s->rk.dname)==0 && + (qstate->query_flags&BIT_RD) && + !(qstate->query_flags&BIT_CD)) + continue; + + /* generate subrequest for it */ + log_nametypeclass(VERB_ALGO, "schedule addr fetch", + s->rk.dname, ntohs(s->rk.type), + ntohs(s->rk.rrset_class)); + if(!generate_sub_request(s->rk.dname, s->rk.dname_len, + ntohs(s->rk.type), ntohs(s->rk.rrset_class), + qstate, id, iq, + INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) { + verbose(VERB_ALGO, "could not generate addr check"); + return; + } + /* ignore subq - not need for more init */ + } +} + +/** + * Generate a NS check request to obtain authoritative information + * on an NS rrset. + * + * @param qstate: the qtstate that triggered the need to prime. + * @param iq: iterator query state. + * @param id: module id. + */ +static void +generate_ns_check(struct module_qstate* qstate, struct iter_qstate* iq, int id) +{ + struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; + struct module_qstate* subq; + log_assert(iq->dp); + + if(iq->depth == ie->max_dependency_depth) + return; + /* is this query the same as the nscheck? */ + if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS && + query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 && + (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){ + /* spawn off A, AAAA queries for in-zone glue to check */ + generate_a_aaaa_check(qstate, iq, id); + return; + } + + log_nametypeclass(VERB_ALGO, "schedule ns fetch", + iq->dp->name, LDNS_RR_TYPE_NS, iq->qchase.qclass); + if(!generate_sub_request(iq->dp->name, iq->dp->namelen, + LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq, + INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) { + verbose(VERB_ALGO, "could not generate ns check"); + return; + } + if(subq) { + struct iter_qstate* subiq = + (struct iter_qstate*)subq->minfo[id]; + + /* make copy to avoid use of stub dp by different qs/threads */ + /* refetch glue to start higher up the tree */ + subiq->refetch_glue = 1; + subiq->dp = delegpt_copy(iq->dp, subq->region); + if(!subiq->dp) { + log_err("out of memory generating ns check, copydp"); + fptr_ok(fptr_whitelist_modenv_kill_sub( + qstate->env->kill_sub)); + (*qstate->env->kill_sub)(subq); + return; + } + } +} + +/** + * Generate a DNSKEY prefetch query to get the DNSKEY for the DS record we + * just got in a referral (where we have dnssec_expected, thus have trust + * anchors above it). Note that right after calling this routine the + * iterator detached subqueries (because of following the referral), and thus + * the DNSKEY query becomes detached, its return stored in the cache for + * later lookup by the validator. This cache lookup by the validator avoids + * the roundtrip incurred by the DNSKEY query. The DNSKEY query is now + * performed at about the same time the original query is sent to the domain, + * thus the two answers are likely to be returned at about the same time, + * saving a roundtrip from the validated lookup. + * + * @param qstate: the qtstate that triggered the need to prime. + * @param iq: iterator query state. + * @param id: module id. + */ +static void +generate_dnskey_prefetch(struct module_qstate* qstate, + struct iter_qstate* iq, int id) +{ + struct module_qstate* subq; + log_assert(iq->dp); + + /* is this query the same as the prefetch? */ + if(qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY && + query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 && + (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){ + return; + } + + /* if the DNSKEY is in the cache this lookup will stop quickly */ + log_nametypeclass(VERB_ALGO, "schedule dnskey prefetch", + iq->dp->name, LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass); + if(!generate_sub_request(iq->dp->name, iq->dp->namelen, + LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass, qstate, id, iq, + INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) { + /* we'll be slower, but it'll work */ + verbose(VERB_ALGO, "could not generate dnskey prefetch"); + return; + } + if(subq) { + struct iter_qstate* subiq = + (struct iter_qstate*)subq->minfo[id]; + /* this qstate has the right delegation for the dnskey lookup*/ + /* make copy to avoid use of stub dp by different qs/threads */ + subiq->dp = delegpt_copy(iq->dp, subq->region); + /* if !subiq->dp, it'll start from the cache, no problem */ + } +} + +/** + * See if the query needs forwarding. + * + * @param qstate: query state. + * @param iq: iterator query state. + * @return true if the request is forwarded, false if not. + * If returns true but, iq->dp is NULL then a malloc failure occurred. + */ +static int +forward_request(struct module_qstate* qstate, struct iter_qstate* iq) +{ + struct delegpt* dp; + uint8_t* delname = iq->qchase.qname; + size_t delnamelen = iq->qchase.qname_len; + if(iq->refetch_glue) { + delname = iq->dp->name; + delnamelen = iq->dp->namelen; + } + /* strip one label off of DS query to lookup higher for it */ + if( (iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) + && !dname_is_root(iq->qchase.qname)) + dname_remove_label(&delname, &delnamelen); + dp = forwards_lookup(qstate->env->fwds, delname, iq->qchase.qclass); + if(!dp) + return 0; + /* send recursion desired to forward addr */ + iq->chase_flags |= BIT_RD; + iq->dp = delegpt_copy(dp, qstate->region); + /* iq->dp checked by caller */ + verbose(VERB_ALGO, "forwarding request"); + return 1; +} + +/** + * Process the initial part of the request handling. This state roughly + * corresponds to resolver algorithms steps 1 (find answer in cache) and 2 + * (find the best servers to ask). + * + * Note that all requests start here, and query restarts revisit this state. + * + * This state either generates: 1) a response, from cache or error, 2) a + * priming event, or 3) forwards the request to the next state (init2, + * generally). + * + * @param qstate: query state. + * @param iq: iterator query state. + * @param ie: iterator shared global environment. + * @param id: module id. + * @return true if the event needs more request processing immediately, + * false if not. + */ +static int +processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq, + struct iter_env* ie, int id) +{ + uint8_t* delname; + size_t delnamelen; + struct dns_msg* msg; + + log_query_info(VERB_DETAIL, "resolving", &qstate->qinfo); + /* check effort */ + + /* We enforce a maximum number of query restarts. This is primarily a + * cheap way to prevent CNAME loops. */ + if(iq->query_restart_count > MAX_RESTART_COUNT) { + verbose(VERB_QUERY, "request has exceeded the maximum number" + " of query restarts with %d", iq->query_restart_count); + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + } + + /* We enforce a maximum recursion/dependency depth -- in general, + * this is unnecessary for dependency loops (although it will + * catch those), but it provides a sensible limit to the amount + * of work required to answer a given query. */ + verbose(VERB_ALGO, "request has dependency depth of %d", iq->depth); + if(iq->depth > ie->max_dependency_depth) { + verbose(VERB_QUERY, "request has exceeded the maximum " + "dependency depth with depth of %d", iq->depth); + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + } + + /* If the request is qclass=ANY, setup to generate each class */ + if(qstate->qinfo.qclass == LDNS_RR_CLASS_ANY) { + iq->qchase.qclass = 0; + return next_state(iq, COLLECT_CLASS_STATE); + } + + /* Resolver Algorithm Step 1 -- Look for the answer in local data. */ + + /* This either results in a query restart (CNAME cache response), a + * terminating response (ANSWER), or a cache miss (null). */ + + if(qstate->blacklist) { + /* if cache, or anything else, was blacklisted then + * getting older results from cache is a bad idea, no cache */ + verbose(VERB_ALGO, "cache blacklisted, going to the network"); + msg = NULL; + } else { + msg = dns_cache_lookup(qstate->env, iq->qchase.qname, + iq->qchase.qname_len, iq->qchase.qtype, + iq->qchase.qclass, qstate->region, qstate->env->scratch); + if(!msg && qstate->env->neg_cache) { + /* lookup in negative cache; may result in + * NOERROR/NODATA or NXDOMAIN answers that need validation */ + msg = val_neg_getmsg(qstate->env->neg_cache, &iq->qchase, + qstate->region, qstate->env->rrset_cache, + qstate->env->scratch_buffer, + *qstate->env->now, 1/*add SOA*/, NULL); + } + /* item taken from cache does not match our query name, thus + * security needs to be re-examined later */ + if(msg && query_dname_compare(qstate->qinfo.qname, + iq->qchase.qname) != 0) + msg->rep->security = sec_status_unchecked; + } + if(msg) { + /* handle positive cache response */ + enum response_type type = response_type_from_cache(msg, + &iq->qchase); + if(verbosity >= VERB_ALGO) { + log_dns_msg("msg from cache lookup", &msg->qinfo, + msg->rep); + verbose(VERB_ALGO, "msg ttl is %d, prefetch ttl %d", + (int)msg->rep->ttl, + (int)msg->rep->prefetch_ttl); + } + + if(type == RESPONSE_TYPE_CNAME) { + uint8_t* sname = 0; + size_t slen = 0; + verbose(VERB_ALGO, "returning CNAME response from " + "cache"); + if(!handle_cname_response(qstate, iq, msg, + &sname, &slen)) + return error_response(qstate, id, + LDNS_RCODE_SERVFAIL); + iq->qchase.qname = sname; + iq->qchase.qname_len = slen; + /* This *is* a query restart, even if it is a cheap + * one. */ + iq->dp = NULL; + iq->refetch_glue = 0; + iq->query_restart_count++; + iq->sent_count = 0; + sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); + return next_state(iq, INIT_REQUEST_STATE); + } + + /* if from cache, NULL, else insert 'cache IP' len=0 */ + if(qstate->reply_origin) + sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); + /* it is an answer, response, to final state */ + verbose(VERB_ALGO, "returning answer from cache."); + iq->response = msg; + return final_state(iq); + } + + /* attempt to forward the request */ + if(forward_request(qstate, iq)) + { + if(!iq->dp) { + log_err("alloc failure for forward dp"); + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + } + iq->refetch_glue = 0; + /* the request has been forwarded. + * forwarded requests need to be immediately sent to the + * next state, QUERYTARGETS. */ + return next_state(iq, QUERYTARGETS_STATE); + } + + /* Resolver Algorithm Step 2 -- find the "best" servers. */ + + /* first, adjust for DS queries. To avoid the grandparent problem, + * we just look for the closest set of server to the parent of qname. + * When re-fetching glue we also need to ask the parent. + */ + if(iq->refetch_glue) { + if(!iq->dp) { + log_err("internal or malloc fail: no dp for refetch"); + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + } + delname = iq->dp->name; + delnamelen = iq->dp->namelen; + } else { + delname = iq->qchase.qname; + delnamelen = iq->qchase.qname_len; + } + if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue || + (iq->qchase.qtype == LDNS_RR_TYPE_NS && qstate->prefetch_leeway)) { + /* remove first label from delname, root goes to hints, + * but only to fetch glue, not for qtype=DS. */ + /* also when prefetching an NS record, fetch it again from + * its parent, just as if it expired, so that you do not + * get stuck on an older nameserver that gives old NSrecords */ + if(dname_is_root(delname) && (iq->refetch_glue || + (iq->qchase.qtype == LDNS_RR_TYPE_NS && + qstate->prefetch_leeway))) + delname = NULL; /* go to root priming */ + else dname_remove_label(&delname, &delnamelen); + } + /* delname is the name to lookup a delegation for. If NULL rootprime */ + while(1) { + + /* Lookup the delegation in the cache. If null, then the + * cache needs to be primed for the qclass. */ + if(delname) + iq->dp = dns_cache_find_delegation(qstate->env, delname, + delnamelen, iq->qchase.qtype, iq->qchase.qclass, + qstate->region, &iq->deleg_msg, + *qstate->env->now+qstate->prefetch_leeway); + else iq->dp = NULL; + + /* If the cache has returned nothing, then we have a + * root priming situation. */ + if(iq->dp == NULL) { + /* if there is a stub, then no root prime needed */ + int r = prime_stub(qstate, iq, id, delname, + iq->qchase.qclass); + if(r == 2) + break; /* got noprime-stub-zone, continue */ + else if(r) + return 0; /* stub prime request made */ + if(forwards_lookup_root(qstate->env->fwds, + iq->qchase.qclass)) { + /* forward zone root, no root prime needed */ + /* fill in some dp - safety belt */ + iq->dp = hints_lookup_root(qstate->env->hints, + iq->qchase.qclass); + if(!iq->dp) { + log_err("internal error: no hints dp"); + return error_response(qstate, id, + LDNS_RCODE_SERVFAIL); + } + iq->dp = delegpt_copy(iq->dp, qstate->region); + if(!iq->dp) { + log_err("out of memory in safety belt"); + return error_response(qstate, id, + LDNS_RCODE_SERVFAIL); + } + return next_state(iq, INIT_REQUEST_2_STATE); + } + /* Note that the result of this will set a new + * DelegationPoint based on the result of priming. */ + if(!prime_root(qstate, iq, id, iq->qchase.qclass)) + return error_response(qstate, id, + LDNS_RCODE_REFUSED); + + /* priming creates and sends a subordinate query, with + * this query as the parent. So further processing for + * this event will stop until reactivated by the + * results of priming. */ + return 0; + } + + /* see if this dp not useless. + * It is useless if: + * o all NS items are required glue. + * or the query is for NS item that is required glue. + * o no addresses are provided. + * o RD qflag is on. + * Instead, go up one level, and try to get even further + * If the root was useless, use safety belt information. + * Only check cache returns, because replies for servers + * could be useless but lead to loops (bumping into the + * same server reply) if useless-checked. + */ + if(iter_dp_is_useless(&qstate->qinfo, qstate->query_flags, + iq->dp)) { + if(dname_is_root(iq->dp->name)) { + /* use safety belt */ + verbose(VERB_QUERY, "Cache has root NS but " + "no addresses. Fallback to the safety belt."); + iq->dp = hints_lookup_root(qstate->env->hints, + iq->qchase.qclass); + /* note deleg_msg is from previous lookup, + * but RD is on, so it is not used */ + if(!iq->dp) { + log_err("internal error: no hints dp"); + return error_response(qstate, id, + LDNS_RCODE_REFUSED); + } + iq->dp = delegpt_copy(iq->dp, qstate->region); + if(!iq->dp) { + log_err("out of memory in safety belt"); + return error_response(qstate, id, + LDNS_RCODE_SERVFAIL); + } + break; + } else { + verbose(VERB_ALGO, + "cache delegation was useless:"); + delegpt_log(VERB_ALGO, iq->dp); + /* go up */ + delname = iq->dp->name; + delnamelen = iq->dp->namelen; + dname_remove_label(&delname, &delnamelen); + } + } else break; + } + + verbose(VERB_ALGO, "cache delegation returns delegpt"); + delegpt_log(VERB_ALGO, iq->dp); + + /* Otherwise, set the current delegation point and move on to the + * next state. */ + return next_state(iq, INIT_REQUEST_2_STATE); +} + +/** + * Process the second part of the initial request handling. This state + * basically exists so that queries that generate root priming events have + * the same init processing as ones that do not. Request events that reach + * this state must have a valid currentDelegationPoint set. + * + * This part is primarly handling stub zone priming. Events that reach this + * state must have a current delegation point. + * + * @param qstate: query state. + * @param iq: iterator query state. + * @param id: module id. + * @return true if the event needs more request processing immediately, + * false if not. + */ +static int +processInitRequest2(struct module_qstate* qstate, struct iter_qstate* iq, + int id) +{ + uint8_t* delname; + size_t delnamelen; + log_query_info(VERB_QUERY, "resolving (init part 2): ", + &qstate->qinfo); + + if(iq->refetch_glue) { + if(!iq->dp) { + log_err("internal or malloc fail: no dp for refetch"); + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + } + delname = iq->dp->name; + delnamelen = iq->dp->namelen; + } else { + delname = iq->qchase.qname; + delnamelen = iq->qchase.qname_len; + } + if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) { + if(!dname_is_root(delname)) + dname_remove_label(&delname, &delnamelen); + iq->refetch_glue = 0; /* if CNAME causes restart, no refetch */ + } + /* Check to see if we need to prime a stub zone. */ + if(prime_stub(qstate, iq, id, delname, iq->qchase.qclass)) { + /* A priming sub request was made */ + return 0; + } + + /* most events just get forwarded to the next state. */ + return next_state(iq, INIT_REQUEST_3_STATE); +} + +/** + * Process the third part of the initial request handling. This state exists + * as a separate state so that queries that generate stub priming events + * will get the tail end of the init process but not repeat the stub priming + * check. + * + * @param qstate: query state. + * @param iq: iterator query state. + * @param id: module id. + * @return true, advancing the event to the QUERYTARGETS_STATE. + */ +static int +processInitRequest3(struct module_qstate* qstate, struct iter_qstate* iq, + int id) +{ + log_query_info(VERB_QUERY, "resolving (init part 3): ", + &qstate->qinfo); + /* if the cache reply dp equals a validation anchor or msg has DS, + * then DNSSEC RRSIGs are expected in the reply */ + iq->dnssec_expected = iter_indicates_dnssec(qstate->env, iq->dp, + iq->deleg_msg, iq->qchase.qclass); + + /* If the RD flag wasn't set, then we just finish with the + * cached referral as the response. */ + if(!(qstate->query_flags & BIT_RD)) { + iq->response = iq->deleg_msg; + if(verbosity >= VERB_ALGO && iq->response) + log_dns_msg("no RD requested, using delegation msg", + &iq->response->qinfo, iq->response->rep); + if(qstate->reply_origin) + sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); + return final_state(iq); + } + /* After this point, unset the RD flag -- this query is going to + * be sent to an auth. server. */ + iq->chase_flags &= ~BIT_RD; + + /* if dnssec expected, fetch key for the trust-anchor or cached-DS */ + if(iq->dnssec_expected && qstate->env->cfg->prefetch_key && + !(qstate->query_flags&BIT_CD)) { + generate_dnskey_prefetch(qstate, iq, id); + fptr_ok(fptr_whitelist_modenv_detach_subs( + qstate->env->detach_subs)); + (*qstate->env->detach_subs)(qstate); + } + + /* Jump to the next state. */ + return next_state(iq, QUERYTARGETS_STATE); +} + +/** + * Given a basic query, generate a parent-side "target" query. + * These are subordinate queries for missing delegation point target addresses, + * for which only the parent of the delegation provides correct IP addresses. + * + * @param qstate: query state. + * @param iq: iterator query state. + * @param id: module id. + * @param name: target qname. + * @param namelen: target qname length. + * @param qtype: target qtype (either A or AAAA). + * @param qclass: target qclass. + * @return true on success, false on failure. + */ +static int +generate_parentside_target_query(struct module_qstate* qstate, + struct iter_qstate* iq, int id, uint8_t* name, size_t namelen, + uint16_t qtype, uint16_t qclass) +{ + struct module_qstate* subq; + if(!generate_sub_request(name, namelen, qtype, qclass, qstate, + id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) + return 0; + if(subq) { + struct iter_qstate* subiq = + (struct iter_qstate*)subq->minfo[id]; + /* blacklist the cache - we want to fetch parent stuff */ + sock_list_insert(&subq->blacklist, NULL, 0, subq->region); + subiq->query_for_pside_glue = 1; + if(dname_subdomain_c(name, iq->dp->name)) { + subiq->dp = delegpt_copy(iq->dp, subq->region); + subiq->dnssec_expected = iter_indicates_dnssec( + qstate->env, subiq->dp, NULL, + subq->qinfo.qclass); + subiq->refetch_glue = 1; + } else { + subiq->dp = dns_cache_find_delegation(qstate->env, + name, namelen, qtype, qclass, subq->region, + &subiq->deleg_msg, + *qstate->env->now+subq->prefetch_leeway); + /* if no dp, then it's from root, refetch unneeded */ + if(subiq->dp) { + subiq->dnssec_expected = iter_indicates_dnssec( + qstate->env, subiq->dp, NULL, + subq->qinfo.qclass); + subiq->refetch_glue = 1; + } + } + } + log_nametypeclass(VERB_QUERY, "new pside target", name, qtype, qclass); + return 1; +} + +/** + * Given a basic query, generate a "target" query. These are subordinate + * queries for missing delegation point target addresses. + * + * @param qstate: query state. + * @param iq: iterator query state. + * @param id: module id. + * @param name: target qname. + * @param namelen: target qname length. + * @param qtype: target qtype (either A or AAAA). + * @param qclass: target qclass. + * @return true on success, false on failure. + */ +static int +generate_target_query(struct module_qstate* qstate, struct iter_qstate* iq, + int id, uint8_t* name, size_t namelen, uint16_t qtype, uint16_t qclass) +{ + struct module_qstate* subq; + if(!generate_sub_request(name, namelen, qtype, qclass, qstate, + id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) + return 0; + log_nametypeclass(VERB_QUERY, "new target", name, qtype, qclass); + return 1; +} + +/** + * Given an event at a certain state, generate zero or more target queries + * for it's current delegation point. + * + * @param qstate: query state. + * @param iq: iterator query state. + * @param ie: iterator shared global environment. + * @param id: module id. + * @param maxtargets: The maximum number of targets to query for. + * if it is negative, there is no maximum number of targets. + * @param num: returns the number of queries generated and processed, + * which may be zero if there were no missing targets. + * @return false on error. + */ +static int +query_for_targets(struct module_qstate* qstate, struct iter_qstate* iq, + struct iter_env* ie, int id, int maxtargets, int* num) +{ + int query_count = 0; + struct delegpt_ns* ns; + int missing; + int toget = 0; + + if(iq->depth == ie->max_dependency_depth) + return 0; + + iter_mark_cycle_targets(qstate, iq->dp); + missing = (int)delegpt_count_missing_targets(iq->dp); + log_assert(maxtargets != 0); /* that would not be useful */ + + /* Generate target requests. Basically, any missing targets + * are queried for here, regardless if it is necessary to do + * so to continue processing. */ + if(maxtargets < 0 || maxtargets > missing) + toget = missing; + else toget = maxtargets; + if(toget == 0) { + *num = 0; + return 1; + } + /* select 'toget' items from the total of 'missing' items */ + log_assert(toget <= missing); + + /* loop over missing targets */ + for(ns = iq->dp->nslist; ns; ns = ns->next) { + if(ns->resolved) + continue; + + /* randomly select this item with probability toget/missing */ + if(!iter_ns_probability(qstate->env->rnd, toget, missing)) { + /* do not select this one, next; select toget number + * of items from a list one less in size */ + missing --; + continue; + } + + if(ie->supports_ipv6 && !ns->got6) { + /* Send the AAAA request. */ + if(!generate_target_query(qstate, iq, id, + ns->name, ns->namelen, + LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) { + *num = query_count; + if(query_count > 0) + qstate->ext_state[id] = module_wait_subquery; + return 0; + } + query_count++; + } + /* Send the A request. */ + if(ie->supports_ipv4 && !ns->got4) { + if(!generate_target_query(qstate, iq, id, + ns->name, ns->namelen, + LDNS_RR_TYPE_A, iq->qchase.qclass)) { + *num = query_count; + if(query_count > 0) + qstate->ext_state[id] = module_wait_subquery; + return 0; + } + query_count++; + } + + /* mark this target as in progress. */ + ns->resolved = 1; + missing--; + toget--; + if(toget == 0) + break; + } + *num = query_count; + if(query_count > 0) + qstate->ext_state[id] = module_wait_subquery; + + return 1; +} + +/** see if last resort is possible - does config allow queries to parent */ +static int +can_have_last_resort(struct module_env* env, struct delegpt* dp, + struct iter_qstate* iq) +{ + struct delegpt* fwddp; + struct iter_hints_stub* stub; + /* do not process a last resort (the parent side) if a stub + * or forward is configured, because we do not want to go 'above' + * the configured servers */ + if(!dname_is_root(dp->name) && (stub = (struct iter_hints_stub*) + name_tree_find(&env->hints->tree, dp->name, dp->namelen, + dp->namelabs, iq->qchase.qclass)) && + /* has_parent side is turned off for stub_first, where we + * are allowed to go to the parent */ + stub->dp->has_parent_side_NS) { + verbose(VERB_QUERY, "configured stub servers failed -- returning SERVFAIL"); + return 0; + } + if((fwddp = forwards_find(env->fwds, dp->name, iq->qchase.qclass)) && + /* has_parent_side is turned off for forward_first, where + * we are allowed to go to the parent */ + fwddp->has_parent_side_NS) { + verbose(VERB_QUERY, "configured forward servers failed -- returning SERVFAIL"); + return 0; + } + return 1; +} + +/** + * Called by processQueryTargets when it would like extra targets to query + * but it seems to be out of options. At last resort some less appealing + * options are explored. If there are no more options, the result is SERVFAIL + * + * @param qstate: query state. + * @param iq: iterator query state. + * @param ie: iterator shared global environment. + * @param id: module id. + * @return true if the event requires more request processing immediately, + * false if not. + */ +static int +processLastResort(struct module_qstate* qstate, struct iter_qstate* iq, + struct iter_env* ie, int id) +{ + struct delegpt_ns* ns; + int query_count = 0; + verbose(VERB_ALGO, "No more query targets, attempting last resort"); + log_assert(iq->dp); + + if(!can_have_last_resort(qstate->env, iq->dp, iq)) { + /* fail -- no more targets, no more hope of targets, no hope + * of a response. */ + return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); + } + if(!iq->dp->has_parent_side_NS && dname_is_root(iq->dp->name)) { + struct delegpt* p = hints_lookup_root(qstate->env->hints, + iq->qchase.qclass); + if(p) { + struct delegpt_ns* ns; + struct delegpt_addr* a; + iq->chase_flags &= ~BIT_RD; /* go to authorities */ + for(ns = p->nslist; ns; ns=ns->next) { + (void)delegpt_add_ns(iq->dp, qstate->region, + ns->name, ns->lame); + } + for(a = p->target_list; a; a=a->next_target) { + (void)delegpt_add_addr(iq->dp, qstate->region, + &a->addr, a->addrlen, a->bogus, + a->lame); + } + } + iq->dp->has_parent_side_NS = 1; + } else if(!iq->dp->has_parent_side_NS) { + if(!iter_lookup_parent_NS_from_cache(qstate->env, iq->dp, + qstate->region, &qstate->qinfo) + || !iq->dp->has_parent_side_NS) { + /* if: malloc failure in lookup go up to try */ + /* if: no parent NS in cache - go up one level */ + verbose(VERB_ALGO, "try to grab parent NS"); + iq->store_parent_NS = iq->dp; + iq->chase_flags &= ~BIT_RD; /* go to authorities */ + iq->deleg_msg = NULL; + iq->refetch_glue = 1; + iq->query_restart_count++; + iq->sent_count = 0; + return next_state(iq, INIT_REQUEST_STATE); + } + } + /* see if that makes new names available */ + if(!cache_fill_missing(qstate->env, iq->qchase.qclass, + qstate->region, iq->dp)) + log_err("out of memory in cache_fill_missing"); + if(iq->dp->usable_list) { + verbose(VERB_ALGO, "try parent-side-name, w. glue from cache"); + return next_state(iq, QUERYTARGETS_STATE); + } + /* try to fill out parent glue from cache */ + if(iter_lookup_parent_glue_from_cache(qstate->env, iq->dp, + qstate->region, &qstate->qinfo)) { + /* got parent stuff from cache, see if we can continue */ + verbose(VERB_ALGO, "try parent-side glue from cache"); + return next_state(iq, QUERYTARGETS_STATE); + } + /* query for an extra name added by the parent-NS record */ + if(delegpt_count_missing_targets(iq->dp) > 0) { + int qs = 0; + verbose(VERB_ALGO, "try parent-side target name"); + if(!query_for_targets(qstate, iq, ie, id, 1, &qs)) { + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + } + iq->num_target_queries += qs; + if(qs != 0) { + qstate->ext_state[id] = module_wait_subquery; + return 0; /* and wait for them */ + } + } + if(iq->depth == ie->max_dependency_depth) { + verbose(VERB_QUERY, "maxdepth and need more nameservers, fail"); + return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); + } + /* mark cycle targets for parent-side lookups */ + iter_mark_pside_cycle_targets(qstate, iq->dp); + /* see if we can issue queries to get nameserver addresses */ + /* this lookup is not randomized, but sequential. */ + for(ns = iq->dp->nslist; ns; ns = ns->next) { + /* query for parent-side A and AAAA for nameservers */ + if(ie->supports_ipv6 && !ns->done_pside6) { + /* Send the AAAA request. */ + if(!generate_parentside_target_query(qstate, iq, id, + ns->name, ns->namelen, + LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) + return error_response(qstate, id, + LDNS_RCODE_SERVFAIL); + ns->done_pside6 = 1; + query_count++; + } + if(ie->supports_ipv4 && !ns->done_pside4) { + /* Send the A request. */ + if(!generate_parentside_target_query(qstate, iq, id, + ns->name, ns->namelen, + LDNS_RR_TYPE_A, iq->qchase.qclass)) + return error_response(qstate, id, + LDNS_RCODE_SERVFAIL); + ns->done_pside4 = 1; + query_count++; + } + if(query_count != 0) { /* suspend to await results */ + verbose(VERB_ALGO, "try parent-side glue lookup"); + iq->num_target_queries += query_count; + qstate->ext_state[id] = module_wait_subquery; + return 0; + } + } + + /* if this was a parent-side glue query itself, then store that + * failure in cache. */ + if(iq->query_for_pside_glue && !iq->pside_glue) + iter_store_parentside_neg(qstate->env, &qstate->qinfo, + iq->deleg_msg?iq->deleg_msg->rep: + (iq->response?iq->response->rep:NULL)); + + verbose(VERB_QUERY, "out of query targets -- returning SERVFAIL"); + /* fail -- no more targets, no more hope of targets, no hope + * of a response. */ + return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); +} + +/** + * Try to find the NS record set that will resolve a qtype DS query. Due + * to grandparent/grandchild reasons we did not get a proper lookup right + * away. We need to create type NS queries until we get the right parent + * for this lookup. We remove labels from the query to find the right point. + * If we end up at the old dp name, then there is no solution. + * + * @param qstate: query state. + * @param iq: iterator query state. + * @param id: module id. + * @return true if the event requires more immediate processing, false if + * not. This is generally only true when forwarding the request to + * the final state (i.e., on answer). + */ +static int +processDSNSFind(struct module_qstate* qstate, struct iter_qstate* iq, int id) +{ + struct module_qstate* subq = NULL; + verbose(VERB_ALGO, "processDSNSFind"); + + if(!iq->dsns_point) { + /* initialize */ + iq->dsns_point = iq->qchase.qname; + iq->dsns_point_len = iq->qchase.qname_len; + } + /* robustcheck for internal error: we are not underneath the dp */ + if(!dname_subdomain_c(iq->dsns_point, iq->dp->name)) { + return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); + } + + /* go up one (more) step, until we hit the dp, if so, end */ + dname_remove_label(&iq->dsns_point, &iq->dsns_point_len); + if(query_dname_compare(iq->dsns_point, iq->dp->name) == 0) { + /* there was no inbetween nameserver, use the old delegation + * point again. And this time, because dsns_point is nonNULL + * we are going to accept the (bad) result */ + iq->state = QUERYTARGETS_STATE; + return 1; + } + iq->state = DSNS_FIND_STATE; + + /* spawn NS lookup (validation not needed, this is for DS lookup) */ + log_nametypeclass(VERB_ALGO, "fetch nameservers", + iq->dsns_point, LDNS_RR_TYPE_NS, iq->qchase.qclass); + if(!generate_sub_request(iq->dsns_point, iq->dsns_point_len, + LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq, + INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) { + return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); + } + + return 0; +} + +/** + * This is the request event state where the request will be sent to one of + * its current query targets. This state also handles issuing target lookup + * queries for missing target IP addresses. Queries typically iterate on + * this state, both when they are just trying different targets for a given + * delegation point, and when they change delegation points. This state + * roughly corresponds to RFC 1034 algorithm steps 3 and 4. + * + * @param qstate: query state. + * @param iq: iterator query state. + * @param ie: iterator shared global environment. + * @param id: module id. + * @return true if the event requires more request processing immediately, + * false if not. This state only returns true when it is generating + * a SERVFAIL response because the query has hit a dead end. + */ +static int +processQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq, + struct iter_env* ie, int id) +{ + int tf_policy; + struct delegpt_addr* target; + struct outbound_entry* outq; + + /* NOTE: a request will encounter this state for each target it + * needs to send a query to. That is, at least one per referral, + * more if some targets timeout or return throwaway answers. */ + + log_query_info(VERB_QUERY, "processQueryTargets:", &qstate->qinfo); + verbose(VERB_ALGO, "processQueryTargets: targetqueries %d, " + "currentqueries %d sentcount %d", iq->num_target_queries, + iq->num_current_queries, iq->sent_count); + + /* Make sure that we haven't run away */ + /* FIXME: is this check even necessary? */ + if(iq->referral_count > MAX_REFERRAL_COUNT) { + verbose(VERB_QUERY, "request has exceeded the maximum " + "number of referrrals with %d", iq->referral_count); + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + } + if(iq->sent_count > MAX_SENT_COUNT) { + verbose(VERB_QUERY, "request has exceeded the maximum " + "number of sends with %d", iq->sent_count); + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + } + + /* Make sure we have a delegation point, otherwise priming failed + * or another failure occurred */ + if(!iq->dp) { + verbose(VERB_QUERY, "Failed to get a delegation, giving up"); + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + } + if(!ie->supports_ipv6) + delegpt_no_ipv6(iq->dp); + if(!ie->supports_ipv4) + delegpt_no_ipv4(iq->dp); + delegpt_log(VERB_ALGO, iq->dp); + + if(iq->num_current_queries>0) { + /* already busy answering a query, this restart is because + * more delegpt addrs became available, wait for existing + * query. */ + verbose(VERB_ALGO, "woke up, but wait for outstanding query"); + qstate->ext_state[id] = module_wait_reply; + return 0; + } + + tf_policy = 0; + /* < not <=, because although the array is large enough for <=, the + * generated query will immediately be discarded due to depth and + * that servfail is cached, which is not good as opportunism goes. */ + if(iq->depth < ie->max_dependency_depth + && iq->sent_count < TARGET_FETCH_STOP) { + tf_policy = ie->target_fetch_policy[iq->depth]; + } + + /* if in 0x20 fallback get as many targets as possible */ + if(iq->caps_fallback) { + int extra = 0; + size_t naddr, nres, navail; + if(!query_for_targets(qstate, iq, ie, id, -1, &extra)) { + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + } + iq->num_target_queries += extra; + if(iq->num_target_queries > 0) { + /* wait to get all targets, we want to try em */ + verbose(VERB_ALGO, "wait for all targets for fallback"); + qstate->ext_state[id] = module_wait_reply; + return 0; + } + /* did we do enough fallback queries already? */ + delegpt_count_addr(iq->dp, &naddr, &nres, &navail); + /* the current caps_server is the number of fallbacks sent. + * the original query is one that matched too, so we have + * caps_server+1 number of matching queries now */ + if(iq->caps_server+1 >= naddr*3 || + iq->caps_server+1 >= MAX_SENT_COUNT) { + /* we're done, process the response */ + verbose(VERB_ALGO, "0x20 fallback had %d responses " + "match for %d wanted, done.", + (int)iq->caps_server+1, (int)naddr*3); + iq->caps_fallback = 0; + iter_dec_attempts(iq->dp, 3); /* space for fallback */ + iq->num_current_queries++; /* RespState decrements it*/ + iq->referral_count++; /* make sure we don't loop */ + iq->sent_count = 0; + iq->state = QUERY_RESP_STATE; + return 1; + } + verbose(VERB_ALGO, "0x20 fallback number %d", + (int)iq->caps_server); + + /* if there is a policy to fetch missing targets + * opportunistically, do it. we rely on the fact that once a + * query (or queries) for a missing name have been issued, + * they will not show up again. */ + } else if(tf_policy != 0) { + int extra = 0; + verbose(VERB_ALGO, "attempt to get extra %d targets", + tf_policy); + (void)query_for_targets(qstate, iq, ie, id, tf_policy, &extra); + /* errors ignored, these targets are not strictly necessary for + * this result, we do not have to reply with SERVFAIL */ + iq->num_target_queries += extra; + } + + /* Add the current set of unused targets to our queue. */ + delegpt_add_unused_targets(iq->dp); + + /* Select the next usable target, filtering out unsuitable targets. */ + target = iter_server_selection(ie, qstate->env, iq->dp, + iq->dp->name, iq->dp->namelen, iq->qchase.qtype, + &iq->dnssec_lame_query, &iq->chase_to_rd, + iq->num_target_queries, qstate->blacklist); + + /* If no usable target was selected... */ + if(!target) { + /* Here we distinguish between three states: generate a new + * target query, just wait, or quit (with a SERVFAIL). + * We have the following information: number of active + * target queries, number of active current queries, + * the presence of missing targets at this delegation + * point, and the given query target policy. */ + + /* Check for the wait condition. If this is true, then + * an action must be taken. */ + if(iq->num_target_queries==0 && iq->num_current_queries==0) { + /* If there is nothing to wait for, then we need + * to distinguish between generating (a) new target + * query, or failing. */ + if(delegpt_count_missing_targets(iq->dp) > 0) { + int qs = 0; + verbose(VERB_ALGO, "querying for next " + "missing target"); + if(!query_for_targets(qstate, iq, ie, id, + 1, &qs)) { + return error_response(qstate, id, + LDNS_RCODE_SERVFAIL); + } + if(qs == 0 && + delegpt_count_missing_targets(iq->dp) == 0){ + /* it looked like there were missing + * targets, but they did not turn up. + * Try the bad choices again (if any), + * when we get back here missing==0, + * so this is not a loop. */ + return 1; + } + iq->num_target_queries += qs; + } + /* Since a target query might have been made, we + * need to check again. */ + if(iq->num_target_queries == 0) { + return processLastResort(qstate, iq, ie, id); + } + } + + /* otherwise, we have no current targets, so submerge + * until one of the target or direct queries return. */ + if(iq->num_target_queries>0 && iq->num_current_queries>0) { + verbose(VERB_ALGO, "no current targets -- waiting " + "for %d targets to resolve or %d outstanding" + " queries to respond", iq->num_target_queries, + iq->num_current_queries); + qstate->ext_state[id] = module_wait_reply; + } else if(iq->num_target_queries>0) { + verbose(VERB_ALGO, "no current targets -- waiting " + "for %d targets to resolve.", + iq->num_target_queries); + qstate->ext_state[id] = module_wait_subquery; + } else { + verbose(VERB_ALGO, "no current targets -- waiting " + "for %d outstanding queries to respond.", + iq->num_current_queries); + qstate->ext_state[id] = module_wait_reply; + } + return 0; + } + + /* We have a valid target. */ + if(verbosity >= VERB_QUERY) { + log_query_info(VERB_QUERY, "sending query:", &iq->qchase); + log_name_addr(VERB_QUERY, "sending to target:", iq->dp->name, + &target->addr, target->addrlen); + verbose(VERB_ALGO, "dnssec status: %s%s", + iq->dnssec_expected?"expected": "not expected", + iq->dnssec_lame_query?" but lame_query anyway": ""); + } + fptr_ok(fptr_whitelist_modenv_send_query(qstate->env->send_query)); + outq = (*qstate->env->send_query)( + iq->qchase.qname, iq->qchase.qname_len, + iq->qchase.qtype, iq->qchase.qclass, + iq->chase_flags | (iq->chase_to_rd?BIT_RD:0), EDNS_DO|BIT_CD, + iq->dnssec_expected, iq->caps_fallback, &target->addr, + target->addrlen, iq->dp->name, iq->dp->namelen, qstate); + if(!outq) { + log_addr(VERB_DETAIL, "error sending query to auth server", + &target->addr, target->addrlen); + return next_state(iq, QUERYTARGETS_STATE); + } + outbound_list_insert(&iq->outlist, outq); + iq->num_current_queries++; + iq->sent_count++; + qstate->ext_state[id] = module_wait_reply; + + return 0; +} + +/** find NS rrset in given list */ +static struct ub_packed_rrset_key* +find_NS(struct reply_info* rep, size_t from, size_t to) +{ + size_t i; + for(i=from; i<to; i++) { + if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS) + return rep->rrsets[i]; + } + return NULL; +} + + +/** + * Process the query response. All queries end up at this state first. This + * process generally consists of analyzing the response and routing the + * event to the next state (either bouncing it back to a request state, or + * terminating the processing for this event). + * + * @param qstate: query state. + * @param iq: iterator query state. + * @param id: module id. + * @return true if the event requires more immediate processing, false if + * not. This is generally only true when forwarding the request to + * the final state (i.e., on answer). + */ +static int +processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq, + int id) +{ + int dnsseclame = 0; + enum response_type type; + iq->num_current_queries--; + if(iq->response == NULL) { + iq->chase_to_rd = 0; + iq->dnssec_lame_query = 0; + verbose(VERB_ALGO, "query response was timeout"); + return next_state(iq, QUERYTARGETS_STATE); + } + type = response_type_from_server( + (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd), + iq->response, &iq->qchase, iq->dp); + iq->chase_to_rd = 0; + if(type == RESPONSE_TYPE_REFERRAL && (iq->chase_flags&BIT_RD)) { + /* When forwarding (RD bit is set), we handle referrals + * differently. No queries should be sent elsewhere */ + type = RESPONSE_TYPE_ANSWER; + } + if(iq->dnssec_expected && !iq->dnssec_lame_query && + !(iq->chase_flags&BIT_RD) + && type != RESPONSE_TYPE_LAME + && type != RESPONSE_TYPE_REC_LAME + && type != RESPONSE_TYPE_THROWAWAY + && type != RESPONSE_TYPE_UNTYPED) { + /* a possible answer, see if it is missing DNSSEC */ + /* but not when forwarding, so we dont mark fwder lame */ + if(!iter_msg_has_dnssec(iq->response)) { + /* Mark this address as dnsseclame in this dp, + * because that will make serverselection disprefer + * it, but also, once it is the only final option, + * use dnssec-lame-bypass if it needs to query there.*/ + if(qstate->reply) { + struct delegpt_addr* a = delegpt_find_addr( + iq->dp, &qstate->reply->addr, + qstate->reply->addrlen); + if(a) a->dnsseclame = 1; + } + /* test the answer is from the zone we expected, + * otherwise, (due to parent,child on same server), we + * might mark the server,zone lame inappropriately */ + if(!iter_msg_from_zone(iq->response, iq->dp, type, + iq->qchase.qclass)) + qstate->reply = NULL; + type = RESPONSE_TYPE_LAME; + dnsseclame = 1; + } + } else iq->dnssec_lame_query = 0; + /* see if referral brings us close to the target */ + if(type == RESPONSE_TYPE_REFERRAL) { + struct ub_packed_rrset_key* ns = find_NS( + iq->response->rep, iq->response->rep->an_numrrsets, + iq->response->rep->an_numrrsets + + iq->response->rep->ns_numrrsets); + if(!ns) ns = find_NS(iq->response->rep, 0, + iq->response->rep->an_numrrsets); + if(!ns || !dname_strict_subdomain_c(ns->rk.dname, iq->dp->name) + || !dname_subdomain_c(iq->qchase.qname, ns->rk.dname)){ + verbose(VERB_ALGO, "bad referral, throwaway"); + type = RESPONSE_TYPE_THROWAWAY; + } else + iter_scrub_ds(iq->response, ns, iq->dp->name); + } else iter_scrub_ds(iq->response, NULL, NULL); + + /* handle each of the type cases */ + if(type == RESPONSE_TYPE_ANSWER) { + /* ANSWER type responses terminate the query algorithm, + * so they sent on their */ + if(verbosity >= VERB_DETAIL) { + verbose(VERB_DETAIL, "query response was %s", + FLAGS_GET_RCODE(iq->response->rep->flags) + ==LDNS_RCODE_NXDOMAIN?"NXDOMAIN ANSWER": + (iq->response->rep->an_numrrsets?"ANSWER": + "nodata ANSWER")); + } + /* if qtype is DS, check we have the right level of answer, + * like grandchild answer but we need the middle, reject it */ + if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point + && !(iq->chase_flags&BIT_RD) + && iter_ds_toolow(iq->response, iq->dp) + && iter_dp_cangodown(&iq->qchase, iq->dp)) { + /* close down outstanding requests to be discarded */ + outbound_list_clear(&iq->outlist); + iq->num_current_queries = 0; + fptr_ok(fptr_whitelist_modenv_detach_subs( + qstate->env->detach_subs)); + (*qstate->env->detach_subs)(qstate); + iq->num_target_queries = 0; + return processDSNSFind(qstate, iq, id); + } + iter_dns_store(qstate->env, &iq->response->qinfo, + iq->response->rep, 0, qstate->prefetch_leeway, + iq->dp&&iq->dp->has_parent_side_NS, + qstate->region); + /* close down outstanding requests to be discarded */ + outbound_list_clear(&iq->outlist); + iq->num_current_queries = 0; + fptr_ok(fptr_whitelist_modenv_detach_subs( + qstate->env->detach_subs)); + (*qstate->env->detach_subs)(qstate); + iq->num_target_queries = 0; + if(qstate->reply) + sock_list_insert(&qstate->reply_origin, + &qstate->reply->addr, qstate->reply->addrlen, + qstate->region); + return final_state(iq); + } else if(type == RESPONSE_TYPE_REFERRAL) { + /* REFERRAL type responses get a reset of the + * delegation point, and back to the QUERYTARGETS_STATE. */ + verbose(VERB_DETAIL, "query response was REFERRAL"); + + /* if hardened, only store referral if we asked for it */ + if(!qstate->env->cfg->harden_referral_path || + ( qstate->qinfo.qtype == LDNS_RR_TYPE_NS + && (qstate->query_flags&BIT_RD) + && !(qstate->query_flags&BIT_CD) + /* we know that all other NS rrsets are scrubbed + * away, thus on referral only one is left. + * see if that equals the query name... */ + && ( /* auth section, but sometimes in answer section*/ + reply_find_rrset_section_ns(iq->response->rep, + iq->qchase.qname, iq->qchase.qname_len, + LDNS_RR_TYPE_NS, iq->qchase.qclass) + || reply_find_rrset_section_an(iq->response->rep, + iq->qchase.qname, iq->qchase.qname_len, + LDNS_RR_TYPE_NS, iq->qchase.qclass) + ) + )) { + /* Store the referral under the current query */ + /* no prefetch-leeway, since its not the answer */ + iter_dns_store(qstate->env, &iq->response->qinfo, + iq->response->rep, 1, 0, 0, NULL); + if(iq->store_parent_NS) + iter_store_parentside_NS(qstate->env, + iq->response->rep); + if(qstate->env->neg_cache) + val_neg_addreferral(qstate->env->neg_cache, + iq->response->rep, iq->dp->name); + } + /* store parent-side-in-zone-glue, if directly queried for */ + if(iq->query_for_pside_glue && !iq->pside_glue) { + iq->pside_glue = reply_find_rrset(iq->response->rep, + iq->qchase.qname, iq->qchase.qname_len, + iq->qchase.qtype, iq->qchase.qclass); + if(iq->pside_glue) { + log_rrset_key(VERB_ALGO, "found parent-side " + "glue", iq->pside_glue); + iter_store_parentside_rrset(qstate->env, + iq->pside_glue); + } + } + + /* Reset the event state, setting the current delegation + * point to the referral. */ + iq->deleg_msg = iq->response; + iq->dp = delegpt_from_message(iq->response, qstate->region); + if(!iq->dp) + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + if(!cache_fill_missing(qstate->env, iq->qchase.qclass, + qstate->region, iq->dp)) + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + if(iq->store_parent_NS && query_dname_compare(iq->dp->name, + iq->store_parent_NS->name) == 0) + iter_merge_retry_counts(iq->dp, iq->store_parent_NS); + delegpt_log(VERB_ALGO, iq->dp); + /* Count this as a referral. */ + iq->referral_count++; + iq->sent_count = 0; + /* see if the next dp is a trust anchor, or a DS was sent + * along, indicating dnssec is expected for next zone */ + iq->dnssec_expected = iter_indicates_dnssec(qstate->env, + iq->dp, iq->response, iq->qchase.qclass); + /* if dnssec, validating then also fetch the key for the DS */ + if(iq->dnssec_expected && qstate->env->cfg->prefetch_key && + !(qstate->query_flags&BIT_CD)) + generate_dnskey_prefetch(qstate, iq, id); + + /* spawn off NS and addr to auth servers for the NS we just + * got in the referral. This gets authoritative answer + * (answer section trust level) rrset. + * right after, we detach the subs, answer goes to cache. */ + if(qstate->env->cfg->harden_referral_path) + generate_ns_check(qstate, iq, id); + + /* stop current outstanding queries. + * FIXME: should the outstanding queries be waited for and + * handled? Say by a subquery that inherits the outbound_entry. + */ + outbound_list_clear(&iq->outlist); + iq->num_current_queries = 0; + fptr_ok(fptr_whitelist_modenv_detach_subs( + qstate->env->detach_subs)); + (*qstate->env->detach_subs)(qstate); + iq->num_target_queries = 0; + verbose(VERB_ALGO, "cleared outbound list for next round"); + return next_state(iq, QUERYTARGETS_STATE); + } else if(type == RESPONSE_TYPE_CNAME) { + uint8_t* sname = NULL; + size_t snamelen = 0; + /* CNAME type responses get a query restart (i.e., get a + * reset of the query state and go back to INIT_REQUEST_STATE). + */ + verbose(VERB_DETAIL, "query response was CNAME"); + if(verbosity >= VERB_ALGO) + log_dns_msg("cname msg", &iq->response->qinfo, + iq->response->rep); + /* if qtype is DS, check we have the right level of answer, + * like grandchild answer but we need the middle, reject it */ + if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point + && !(iq->chase_flags&BIT_RD) + && iter_ds_toolow(iq->response, iq->dp) + && iter_dp_cangodown(&iq->qchase, iq->dp)) { + outbound_list_clear(&iq->outlist); + iq->num_current_queries = 0; + fptr_ok(fptr_whitelist_modenv_detach_subs( + qstate->env->detach_subs)); + (*qstate->env->detach_subs)(qstate); + iq->num_target_queries = 0; + return processDSNSFind(qstate, iq, id); + } + /* Process the CNAME response. */ + if(!handle_cname_response(qstate, iq, iq->response, + &sname, &snamelen)) + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + /* cache the CNAME response under the current query */ + /* NOTE : set referral=1, so that rrsets get stored but not + * the partial query answer (CNAME only). */ + /* prefetchleeway applied because this updates answer parts */ + iter_dns_store(qstate->env, &iq->response->qinfo, + iq->response->rep, 1, qstate->prefetch_leeway, + iq->dp&&iq->dp->has_parent_side_NS, NULL); + /* set the current request's qname to the new value. */ + iq->qchase.qname = sname; + iq->qchase.qname_len = snamelen; + /* Clear the query state, since this is a query restart. */ + iq->deleg_msg = NULL; + iq->dp = NULL; + iq->dsns_point = NULL; + /* Note the query restart. */ + iq->query_restart_count++; + iq->sent_count = 0; + + /* stop current outstanding queries. + * FIXME: should the outstanding queries be waited for and + * handled? Say by a subquery that inherits the outbound_entry. + */ + outbound_list_clear(&iq->outlist); + iq->num_current_queries = 0; + fptr_ok(fptr_whitelist_modenv_detach_subs( + qstate->env->detach_subs)); + (*qstate->env->detach_subs)(qstate); + iq->num_target_queries = 0; + if(qstate->reply) + sock_list_insert(&qstate->reply_origin, + &qstate->reply->addr, qstate->reply->addrlen, + qstate->region); + verbose(VERB_ALGO, "cleared outbound list for query restart"); + /* go to INIT_REQUEST_STATE for new qname. */ + return next_state(iq, INIT_REQUEST_STATE); + } else if(type == RESPONSE_TYPE_LAME) { + /* Cache the LAMEness. */ + verbose(VERB_DETAIL, "query response was %sLAME", + dnsseclame?"DNSSEC ":""); + if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) { + log_err("mark lame: mismatch in qname and dpname"); + /* throwaway this reply below */ + } else if(qstate->reply) { + /* need addr for lameness cache, but we may have + * gotten this from cache, so test to be sure */ + if(!infra_set_lame(qstate->env->infra_cache, + &qstate->reply->addr, qstate->reply->addrlen, + iq->dp->name, iq->dp->namelen, + *qstate->env->now, dnsseclame, 0, + iq->qchase.qtype)) + log_err("mark host lame: out of memory"); + } + } else if(type == RESPONSE_TYPE_REC_LAME) { + /* Cache the LAMEness. */ + verbose(VERB_DETAIL, "query response REC_LAME: " + "recursive but not authoritative server"); + if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) { + log_err("mark rec_lame: mismatch in qname and dpname"); + /* throwaway this reply below */ + } else if(qstate->reply) { + /* need addr for lameness cache, but we may have + * gotten this from cache, so test to be sure */ + verbose(VERB_DETAIL, "mark as REC_LAME"); + if(!infra_set_lame(qstate->env->infra_cache, + &qstate->reply->addr, qstate->reply->addrlen, + iq->dp->name, iq->dp->namelen, + *qstate->env->now, 0, 1, iq->qchase.qtype)) + log_err("mark host lame: out of memory"); + } + } else if(type == RESPONSE_TYPE_THROWAWAY) { + /* LAME and THROWAWAY responses are handled the same way. + * In this case, the event is just sent directly back to + * the QUERYTARGETS_STATE without resetting anything, + * because, clearly, the next target must be tried. */ + verbose(VERB_DETAIL, "query response was THROWAWAY"); + } else { + log_warn("A query response came back with an unknown type: %d", + (int)type); + } + + /* LAME, THROWAWAY and "unknown" all end up here. + * Recycle to the QUERYTARGETS state to hopefully try a + * different target. */ + return next_state(iq, QUERYTARGETS_STATE); +} + +/** + * Return priming query results to interestes super querystates. + * + * Sets the delegation point and delegation message (not nonRD queries). + * This is a callback from walk_supers. + * + * @param qstate: priming query state that finished. + * @param id: module id. + * @param forq: the qstate for which priming has been done. + */ +static void +prime_supers(struct module_qstate* qstate, int id, struct module_qstate* forq) +{ + struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; + struct delegpt* dp = NULL; + + log_assert(qstate->is_priming || foriq->wait_priming_stub); + log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR); + /* Convert our response to a delegation point */ + dp = delegpt_from_message(qstate->return_msg, forq->region); + if(!dp) { + /* if there is no convertable delegation point, then + * the ANSWER type was (presumably) a negative answer. */ + verbose(VERB_ALGO, "prime response was not a positive " + "ANSWER; failing"); + foriq->dp = NULL; + foriq->state = QUERYTARGETS_STATE; + return; + } + + log_query_info(VERB_DETAIL, "priming successful for", &qstate->qinfo); + delegpt_log(VERB_ALGO, dp); + foriq->dp = dp; + foriq->deleg_msg = dns_copy_msg(qstate->return_msg, forq->region); + if(!foriq->deleg_msg) { + log_err("copy prime response: out of memory"); + foriq->dp = NULL; + foriq->state = QUERYTARGETS_STATE; + return; + } + + /* root priming responses go to init stage 2, priming stub + * responses to to stage 3. */ + if(foriq->wait_priming_stub) { + foriq->state = INIT_REQUEST_3_STATE; + foriq->wait_priming_stub = 0; + } else foriq->state = INIT_REQUEST_2_STATE; + /* because we are finished, the parent will be reactivated */ +} + +/** + * This handles the response to a priming query. This is used to handle both + * root and stub priming responses. This is basically the equivalent of the + * QUERY_RESP_STATE, but will not handle CNAME responses and will treat + * REFERRALs as ANSWERS. It will also update and reactivate the originating + * event. + * + * @param qstate: query state. + * @param id: module id. + * @return true if the event needs more immediate processing, false if not. + * This state always returns false. + */ +static int +processPrimeResponse(struct module_qstate* qstate, int id) +{ + struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; + enum response_type type; + iq->response->rep->flags &= ~(BIT_RD|BIT_RA); /* ignore rec-lame */ + type = response_type_from_server( + (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd), + iq->response, &iq->qchase, iq->dp); + if(type == RESPONSE_TYPE_ANSWER) { + qstate->return_rcode = LDNS_RCODE_NOERROR; + qstate->return_msg = iq->response; + } else { + qstate->return_rcode = LDNS_RCODE_SERVFAIL; + qstate->return_msg = NULL; + } + + /* validate the root or stub after priming (if enabled). + * This is the same query as the prime query, but with validation. + * Now that we are primed, the additional queries that validation + * may need can be resolved, such as DLV. */ + if(qstate->env->cfg->harden_referral_path) { + struct module_qstate* subq = NULL; + log_nametypeclass(VERB_ALGO, "schedule prime validation", + qstate->qinfo.qname, qstate->qinfo.qtype, + qstate->qinfo.qclass); + if(!generate_sub_request(qstate->qinfo.qname, + qstate->qinfo.qname_len, qstate->qinfo.qtype, + qstate->qinfo.qclass, qstate, id, iq, + INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) { + verbose(VERB_ALGO, "could not generate prime check"); + } + generate_a_aaaa_check(qstate, iq, id); + } + + /* This event is finished. */ + qstate->ext_state[id] = module_finished; + return 0; +} + +/** + * Do final processing on responses to target queries. Events reach this + * state after the iterative resolution algorithm terminates. This state is + * responsible for reactiving the original event, and housekeeping related + * to received target responses (caching, updating the current delegation + * point, etc). + * Callback from walk_supers for every super state that is interested in + * the results from this query. + * + * @param qstate: query state. + * @param id: module id. + * @param forq: super query state. + */ +static void +processTargetResponse(struct module_qstate* qstate, int id, + struct module_qstate* forq) +{ + struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; + struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; + struct ub_packed_rrset_key* rrset; + struct delegpt_ns* dpns; + log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR); + + foriq->state = QUERYTARGETS_STATE; + log_query_info(VERB_ALGO, "processTargetResponse", &qstate->qinfo); + log_query_info(VERB_ALGO, "processTargetResponse super", &forq->qinfo); + + /* check to see if parent event is still interested (in orig name). */ + if(!foriq->dp) { + verbose(VERB_ALGO, "subq: parent not interested, was reset"); + return; /* not interested anymore */ + } + dpns = delegpt_find_ns(foriq->dp, qstate->qinfo.qname, + qstate->qinfo.qname_len); + if(!dpns) { + /* If not interested, just stop processing this event */ + verbose(VERB_ALGO, "subq: parent not interested anymore"); + /* could be because parent was jostled out of the cache, + and a new identical query arrived, that does not want it*/ + return; + } + + /* Tell the originating event that this target query has finished + * (regardless if it succeeded or not). */ + foriq->num_target_queries--; + + /* if iq->query_for_pside_glue then add the pside_glue (marked lame) */ + if(iq->pside_glue) { + /* if the pside_glue is NULL, then it could not be found, + * the done_pside is already set when created and a cache + * entry created in processFinished so nothing to do here */ + log_rrset_key(VERB_ALGO, "add parentside glue to dp", + iq->pside_glue); + if(!delegpt_add_rrset(foriq->dp, forq->region, + iq->pside_glue, 1)) + log_err("out of memory adding pside glue"); + } + + /* This response is relevant to the current query, so we + * add (attempt to add, anyway) this target(s) and reactivate + * the original event. + * NOTE: we could only look for the AnswerRRset if the + * response type was ANSWER. */ + rrset = reply_find_answer_rrset(&iq->qchase, qstate->return_msg->rep); + if(rrset) { + /* if CNAMEs have been followed - add new NS to delegpt. */ + /* BTW. RFC 1918 says NS should not have got CNAMEs. Robust. */ + if(!delegpt_find_ns(foriq->dp, rrset->rk.dname, + rrset->rk.dname_len)) { + /* if dpns->lame then set newcname ns lame too */ + if(!delegpt_add_ns(foriq->dp, forq->region, + rrset->rk.dname, dpns->lame)) + log_err("out of memory adding cnamed-ns"); + } + /* if dpns->lame then set the address(es) lame too */ + if(!delegpt_add_rrset(foriq->dp, forq->region, rrset, + dpns->lame)) + log_err("out of memory adding targets"); + verbose(VERB_ALGO, "added target response"); + delegpt_log(VERB_ALGO, foriq->dp); + } else { + verbose(VERB_ALGO, "iterator TargetResponse failed"); + dpns->resolved = 1; /* fail the target */ + } +} + +/** + * Process response for DS NS Find queries, that attempt to find the delegation + * point where we ask the DS query from. + * + * @param qstate: query state. + * @param id: module id. + * @param forq: super query state. + */ +static void +processDSNSResponse(struct module_qstate* qstate, int id, + struct module_qstate* forq) +{ + struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; + + /* if the finished (iq->response) query has no NS set: continue + * up to look for the right dp; nothing to change, do DPNSstate */ + if(qstate->return_rcode != LDNS_RCODE_NOERROR) + return; /* seek further */ + /* find the NS RRset (without allowing CNAMEs) */ + if(!reply_find_rrset(qstate->return_msg->rep, qstate->qinfo.qname, + qstate->qinfo.qname_len, LDNS_RR_TYPE_NS, + qstate->qinfo.qclass)){ + return; /* seek further */ + } + + /* else, store as DP and continue at querytargets */ + foriq->state = QUERYTARGETS_STATE; + foriq->dp = delegpt_from_message(qstate->return_msg, forq->region); + if(!foriq->dp) { + log_err("out of memory in dsns dp alloc"); + return; /* dp==NULL in QUERYTARGETS makes SERVFAIL */ + } + /* success, go query the querytargets in the new dp (and go down) */ +} + +/** + * Process response for qclass=ANY queries for a particular class. + * Append to result or error-exit. + * + * @param qstate: query state. + * @param id: module id. + * @param forq: super query state. + */ +static void +processClassResponse(struct module_qstate* qstate, int id, + struct module_qstate* forq) +{ + struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; + struct dns_msg* from = qstate->return_msg; + log_query_info(VERB_ALGO, "processClassResponse", &qstate->qinfo); + log_query_info(VERB_ALGO, "processClassResponse super", &forq->qinfo); + if(qstate->return_rcode != LDNS_RCODE_NOERROR) { + /* cause servfail for qclass ANY query */ + foriq->response = NULL; + foriq->state = FINISHED_STATE; + return; + } + /* append result */ + if(!foriq->response) { + /* allocate the response: copy RCODE, sec_state */ + foriq->response = dns_copy_msg(from, forq->region); + if(!foriq->response) { + log_err("malloc failed for qclass ANY response"); + foriq->state = FINISHED_STATE; + return; + } + foriq->response->qinfo.qclass = forq->qinfo.qclass; + /* qclass ANY does not receive the AA flag on replies */ + foriq->response->rep->authoritative = 0; + } else { + struct dns_msg* to = foriq->response; + /* add _from_ this response _to_ existing collection */ + /* if there are records, copy RCODE */ + /* lower sec_state if this message is lower */ + if(from->rep->rrset_count != 0) { + size_t n = from->rep->rrset_count+to->rep->rrset_count; + struct ub_packed_rrset_key** dest, **d; + /* copy appropriate rcode */ + to->rep->flags = from->rep->flags; + /* copy rrsets */ + dest = regional_alloc(forq->region, sizeof(dest[0])*n); + if(!dest) { + log_err("malloc failed in collect ANY"); + foriq->state = FINISHED_STATE; + return; + } + d = dest; + /* copy AN */ + memcpy(dest, to->rep->rrsets, to->rep->an_numrrsets + * sizeof(dest[0])); + dest += to->rep->an_numrrsets; + memcpy(dest, from->rep->rrsets, from->rep->an_numrrsets + * sizeof(dest[0])); + dest += from->rep->an_numrrsets; + /* copy NS */ + memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets, + to->rep->ns_numrrsets * sizeof(dest[0])); + dest += to->rep->ns_numrrsets; + memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets, + from->rep->ns_numrrsets * sizeof(dest[0])); + dest += from->rep->ns_numrrsets; + /* copy AR */ + memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets+ + to->rep->ns_numrrsets, + to->rep->ar_numrrsets * sizeof(dest[0])); + dest += to->rep->ar_numrrsets; + memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets+ + from->rep->ns_numrrsets, + from->rep->ar_numrrsets * sizeof(dest[0])); + /* update counts */ + to->rep->rrsets = d; + to->rep->an_numrrsets += from->rep->an_numrrsets; + to->rep->ns_numrrsets += from->rep->ns_numrrsets; + to->rep->ar_numrrsets += from->rep->ar_numrrsets; + to->rep->rrset_count = n; + } + if(from->rep->security < to->rep->security) /* lowest sec */ + to->rep->security = from->rep->security; + if(from->rep->qdcount != 0) /* insert qd if appropriate */ + to->rep->qdcount = from->rep->qdcount; + if(from->rep->ttl < to->rep->ttl) /* use smallest TTL */ + to->rep->ttl = from->rep->ttl; + if(from->rep->prefetch_ttl < to->rep->prefetch_ttl) + to->rep->prefetch_ttl = from->rep->prefetch_ttl; + } + /* are we done? */ + foriq->num_current_queries --; + if(foriq->num_current_queries == 0) + foriq->state = FINISHED_STATE; +} + +/** + * Collect class ANY responses and make them into one response. This + * state is started and it creates queries for all classes (that have + * root hints). The answers are then collected. + * + * @param qstate: query state. + * @param id: module id. + * @return true if the event needs more immediate processing, false if not. + */ +static int +processCollectClass(struct module_qstate* qstate, int id) +{ + struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; + struct module_qstate* subq; + /* If qchase.qclass == 0 then send out queries for all classes. + * Otherwise, do nothing (wait for all answers to arrive and the + * processClassResponse to put them together, and that moves us + * towards the Finished state when done. */ + if(iq->qchase.qclass == 0) { + uint16_t c = 0; + iq->qchase.qclass = LDNS_RR_CLASS_ANY; + while(iter_get_next_root(qstate->env->hints, + qstate->env->fwds, &c)) { + /* generate query for this class */ + log_nametypeclass(VERB_ALGO, "spawn collect query", + qstate->qinfo.qname, qstate->qinfo.qtype, c); + if(!generate_sub_request(qstate->qinfo.qname, + qstate->qinfo.qname_len, qstate->qinfo.qtype, + c, qstate, id, iq, INIT_REQUEST_STATE, + FINISHED_STATE, &subq, + (int)!(qstate->query_flags&BIT_CD))) { + return error_response(qstate, id, + LDNS_RCODE_SERVFAIL); + } + /* ignore subq, no special init required */ + iq->num_current_queries ++; + if(c == 0xffff) + break; + else c++; + } + /* if no roots are configured at all, return */ + if(iq->num_current_queries == 0) { + verbose(VERB_ALGO, "No root hints or fwds, giving up " + "on qclass ANY"); + return error_response(qstate, id, LDNS_RCODE_REFUSED); + } + /* return false, wait for queries to return */ + } + /* if woke up here because of an answer, wait for more answers */ + return 0; +} + +/** + * This handles the final state for first-tier responses (i.e., responses to + * externally generated queries). + * + * @param qstate: query state. + * @param iq: iterator query state. + * @param id: module id. + * @return true if the event needs more processing, false if not. Since this + * is the final state for an event, it always returns false. + */ +static int +processFinished(struct module_qstate* qstate, struct iter_qstate* iq, + int id) +{ + log_query_info(VERB_QUERY, "finishing processing for", + &qstate->qinfo); + + /* store negative cache element for parent side glue. */ + if(iq->query_for_pside_glue && !iq->pside_glue) + iter_store_parentside_neg(qstate->env, &qstate->qinfo, + iq->deleg_msg?iq->deleg_msg->rep: + (iq->response?iq->response->rep:NULL)); + if(!iq->response) { + verbose(VERB_ALGO, "No response is set, servfail"); + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + } + + /* Make sure that the RA flag is set (since the presence of + * this module means that recursion is available) */ + iq->response->rep->flags |= BIT_RA; + + /* Clear the AA flag */ + /* FIXME: does this action go here or in some other module? */ + iq->response->rep->flags &= ~BIT_AA; + + /* make sure QR flag is on */ + iq->response->rep->flags |= BIT_QR; + + /* we have finished processing this query */ + qstate->ext_state[id] = module_finished; + + /* TODO: we are using a private TTL, trim the response. */ + /* if (mPrivateTTL > 0){IterUtils.setPrivateTTL(resp, mPrivateTTL); } */ + + /* prepend any items we have accumulated */ + if(iq->an_prepend_list || iq->ns_prepend_list) { + if(!iter_prepend(iq, iq->response, qstate->region)) { + log_err("prepend rrsets: out of memory"); + return error_response(qstate, id, LDNS_RCODE_SERVFAIL); + } + /* reset the query name back */ + iq->response->qinfo = qstate->qinfo; + /* the security state depends on the combination */ + iq->response->rep->security = sec_status_unchecked; + /* store message with the finished prepended items, + * but only if we did recursion. The nonrecursion referral + * from cache does not need to be stored in the msg cache. */ + if(qstate->query_flags&BIT_RD) { + iter_dns_store(qstate->env, &qstate->qinfo, + iq->response->rep, 0, qstate->prefetch_leeway, + iq->dp&&iq->dp->has_parent_side_NS, + qstate->region); + } + } + qstate->return_rcode = LDNS_RCODE_NOERROR; + qstate->return_msg = iq->response; + return 0; +} + +/* + * Return priming query results to interestes super querystates. + * + * Sets the delegation point and delegation message (not nonRD queries). + * This is a callback from walk_supers. + * + * @param qstate: query state that finished. + * @param id: module id. + * @param super: the qstate to inform. + */ +void +iter_inform_super(struct module_qstate* qstate, int id, + struct module_qstate* super) +{ + if(!qstate->is_priming && super->qinfo.qclass == LDNS_RR_CLASS_ANY) + processClassResponse(qstate, id, super); + else if(super->qinfo.qtype == LDNS_RR_TYPE_DS && ((struct iter_qstate*) + super->minfo[id])->state == DSNS_FIND_STATE) + processDSNSResponse(qstate, id, super); + else if(qstate->return_rcode != LDNS_RCODE_NOERROR) + error_supers(qstate, id, super); + else if(qstate->is_priming) + prime_supers(qstate, id, super); + else processTargetResponse(qstate, id, super); +} + +/** + * Handle iterator state. + * Handle events. This is the real processing loop for events, responsible + * for moving events through the various states. If a processing method + * returns true, then it will be advanced to the next state. If false, then + * processing will stop. + * + * @param qstate: query state. + * @param ie: iterator shared global environment. + * @param iq: iterator query state. + * @param id: module id. + */ +static void +iter_handle(struct module_qstate* qstate, struct iter_qstate* iq, + struct iter_env* ie, int id) +{ + int cont = 1; + while(cont) { + verbose(VERB_ALGO, "iter_handle processing q with state %s", + iter_state_to_string(iq->state)); + switch(iq->state) { + case INIT_REQUEST_STATE: + cont = processInitRequest(qstate, iq, ie, id); + break; + case INIT_REQUEST_2_STATE: + cont = processInitRequest2(qstate, iq, id); + break; + case INIT_REQUEST_3_STATE: + cont = processInitRequest3(qstate, iq, id); + break; + case QUERYTARGETS_STATE: + cont = processQueryTargets(qstate, iq, ie, id); + break; + case QUERY_RESP_STATE: + cont = processQueryResponse(qstate, iq, id); + break; + case PRIME_RESP_STATE: + cont = processPrimeResponse(qstate, id); + break; + case COLLECT_CLASS_STATE: + cont = processCollectClass(qstate, id); + break; + case DSNS_FIND_STATE: + cont = processDSNSFind(qstate, iq, id); + break; + case FINISHED_STATE: + cont = processFinished(qstate, iq, id); + break; + default: + log_warn("iterator: invalid state: %d", + iq->state); + cont = 0; + break; + } + } +} + +/** + * This is the primary entry point for processing request events. Note that + * this method should only be used by external modules. + * @param qstate: query state. + * @param ie: iterator shared global environment. + * @param iq: iterator query state. + * @param id: module id. + */ +static void +process_request(struct module_qstate* qstate, struct iter_qstate* iq, + struct iter_env* ie, int id) +{ + /* external requests start in the INIT state, and finish using the + * FINISHED state. */ + iq->state = INIT_REQUEST_STATE; + iq->final_state = FINISHED_STATE; + verbose(VERB_ALGO, "process_request: new external request event"); + iter_handle(qstate, iq, ie, id); +} + +/** process authoritative server reply */ +static void +process_response(struct module_qstate* qstate, struct iter_qstate* iq, + struct iter_env* ie, int id, struct outbound_entry* outbound, + enum module_ev event) +{ + struct msg_parse* prs; + struct edns_data edns; + sldns_buffer* pkt; + + verbose(VERB_ALGO, "process_response: new external response event"); + iq->response = NULL; + iq->state = QUERY_RESP_STATE; + if(event == module_event_noreply || event == module_event_error) { + if(event == module_event_noreply && iq->sent_count >= 3 && + qstate->env->cfg->use_caps_bits_for_id && + !iq->caps_fallback) { + /* start fallback */ + iq->caps_fallback = 1; + iq->caps_server = 0; + iq->caps_reply = NULL; + iq->state = QUERYTARGETS_STATE; + iq->num_current_queries--; + /* need fresh attempts for the 0x20 fallback, if + * that was the cause for the failure */ + iter_dec_attempts(iq->dp, 3); + verbose(VERB_DETAIL, "Capsforid: timeouts, starting fallback"); + goto handle_it; + } + goto handle_it; + } + if( (event != module_event_reply && event != module_event_capsfail) + || !qstate->reply) { + log_err("Bad event combined with response"); + outbound_list_remove(&iq->outlist, outbound); + (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); + return; + } + + /* parse message */ + prs = (struct msg_parse*)regional_alloc(qstate->env->scratch, + sizeof(struct msg_parse)); + if(!prs) { + log_err("out of memory on incoming message"); + /* like packet got dropped */ + goto handle_it; + } + memset(prs, 0, sizeof(*prs)); + memset(&edns, 0, sizeof(edns)); + pkt = qstate->reply->c->buffer; + sldns_buffer_set_position(pkt, 0); + if(parse_packet(pkt, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) { + verbose(VERB_ALGO, "parse error on reply packet"); + goto handle_it; + } + /* edns is not examined, but removed from message to help cache */ + if(parse_extract_edns(prs, &edns) != LDNS_RCODE_NOERROR) + goto handle_it; + /* remove CD-bit, we asked for in case we handle validation ourself */ + prs->flags &= ~BIT_CD; + + /* normalize and sanitize: easy to delete items from linked lists */ + if(!scrub_message(pkt, prs, &iq->qchase, iq->dp->name, + qstate->env->scratch, qstate->env, ie)) + goto handle_it; + + /* allocate response dns_msg in region */ + iq->response = dns_alloc_msg(pkt, prs, qstate->region); + if(!iq->response) + goto handle_it; + log_query_info(VERB_DETAIL, "response for", &qstate->qinfo); + log_name_addr(VERB_DETAIL, "reply from", iq->dp->name, + &qstate->reply->addr, qstate->reply->addrlen); + if(verbosity >= VERB_ALGO) + log_dns_msg("incoming scrubbed packet:", &iq->response->qinfo, + iq->response->rep); + + if(event == module_event_capsfail || iq->caps_fallback) { + if(!iq->caps_fallback) { + /* start fallback */ + iq->caps_fallback = 1; + iq->caps_server = 0; + iq->caps_reply = iq->response->rep; + iq->state = QUERYTARGETS_STATE; + iq->num_current_queries--; + verbose(VERB_DETAIL, "Capsforid: starting fallback"); + goto handle_it; + } else { + /* check if reply is the same, otherwise, fail */ + if(!iq->caps_reply) { + iq->caps_reply = iq->response->rep; + iq->caps_server = -1; /*become zero at ++, + so that we start the full set of trials */ + } else if(!reply_equal(iq->response->rep, iq->caps_reply, + qstate->env->scratch)) { + verbose(VERB_DETAIL, "Capsforid fallback: " + "getting different replies, failed"); + outbound_list_remove(&iq->outlist, outbound); + (void)error_response(qstate, id, + LDNS_RCODE_SERVFAIL); + return; + } + /* continue the fallback procedure at next server */ + iq->caps_server++; + iq->state = QUERYTARGETS_STATE; + iq->num_current_queries--; + verbose(VERB_DETAIL, "Capsforid: reply is equal. " + "go to next fallback"); + goto handle_it; + } + } + iq->caps_fallback = 0; /* if we were in fallback, 0x20 is OK now */ + +handle_it: + outbound_list_remove(&iq->outlist, outbound); + iter_handle(qstate, iq, ie, id); +} + +void +iter_operate(struct module_qstate* qstate, enum module_ev event, int id, + struct outbound_entry* outbound) +{ + struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; + struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; + verbose(VERB_QUERY, "iterator[module %d] operate: extstate:%s event:%s", + id, strextstate(qstate->ext_state[id]), strmodulevent(event)); + if(iq) log_query_info(VERB_QUERY, "iterator operate: query", + &qstate->qinfo); + if(iq && qstate->qinfo.qname != iq->qchase.qname) + log_query_info(VERB_QUERY, "iterator operate: chased to", + &iq->qchase); + + /* perform iterator state machine */ + if((event == module_event_new || event == module_event_pass) && + iq == NULL) { + if(!iter_new(qstate, id)) { + (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); + return; + } + iq = (struct iter_qstate*)qstate->minfo[id]; + process_request(qstate, iq, ie, id); + return; + } + if(iq && event == module_event_pass) { + iter_handle(qstate, iq, ie, id); + return; + } + if(iq && outbound) { + process_response(qstate, iq, ie, id, outbound, event); + return; + } + if(event == module_event_error) { + verbose(VERB_ALGO, "got called with event error, giving up"); + (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); + return; + } + + log_err("bad event for iterator"); + (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); +} + +void +iter_clear(struct module_qstate* qstate, int id) +{ + struct iter_qstate* iq; + if(!qstate) + return; + iq = (struct iter_qstate*)qstate->minfo[id]; + if(iq) { + outbound_list_clear(&iq->outlist); + iq->num_current_queries = 0; + } + qstate->minfo[id] = NULL; +} + +size_t +iter_get_mem(struct module_env* env, int id) +{ + struct iter_env* ie = (struct iter_env*)env->modinfo[id]; + if(!ie) + return 0; + return sizeof(*ie) + sizeof(int)*((size_t)ie->max_dependency_depth+1) + + donotq_get_mem(ie->donotq) + priv_get_mem(ie->priv); +} + +/** + * The iterator function block + */ +static struct module_func_block iter_block = { + "iterator", + &iter_init, &iter_deinit, &iter_operate, &iter_inform_super, + &iter_clear, &iter_get_mem +}; + +struct module_func_block* +iter_get_funcblock(void) +{ + return &iter_block; +} + +const char* +iter_state_to_string(enum iter_state state) +{ + switch (state) + { + case INIT_REQUEST_STATE : + return "INIT REQUEST STATE"; + case INIT_REQUEST_2_STATE : + return "INIT REQUEST STATE (stage 2)"; + case INIT_REQUEST_3_STATE: + return "INIT REQUEST STATE (stage 3)"; + case QUERYTARGETS_STATE : + return "QUERY TARGETS STATE"; + case PRIME_RESP_STATE : + return "PRIME RESPONSE STATE"; + case COLLECT_CLASS_STATE : + return "COLLECT CLASS STATE"; + case DSNS_FIND_STATE : + return "DSNS FIND STATE"; + case QUERY_RESP_STATE : + return "QUERY RESPONSE STATE"; + case FINISHED_STATE : + return "FINISHED RESPONSE STATE"; + default : + return "UNKNOWN ITER STATE"; + } +} + +int +iter_state_is_responsestate(enum iter_state s) +{ + switch(s) { + case INIT_REQUEST_STATE : + case INIT_REQUEST_2_STATE : + case INIT_REQUEST_3_STATE : + case QUERYTARGETS_STATE : + case COLLECT_CLASS_STATE : + return 0; + default: + break; + } + return 1; +} diff --git a/external/unbound/iterator/iterator.h b/external/unbound/iterator/iterator.h new file mode 100644 index 000000000..0b91760d4 --- /dev/null +++ b/external/unbound/iterator/iterator.h @@ -0,0 +1,372 @@ +/* + * iterator/iterator.h - iterative resolver DNS query response module + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file contains a module that performs recusive iterative DNS query + * processing. + */ + +#ifndef ITERATOR_ITERATOR_H +#define ITERATOR_ITERATOR_H +#include "services/outbound_list.h" +#include "util/data/msgreply.h" +#include "util/module.h" +struct delegpt; +struct iter_hints; +struct iter_forwards; +struct iter_donotq; +struct iter_prep_list; +struct iter_priv; + +/** max number of query restarts. Determines max number of CNAME chain. */ +#define MAX_RESTART_COUNT 8 +/** max number of referrals. Makes sure resolver does not run away */ +#define MAX_REFERRAL_COUNT 130 +/** max number of queries-sent-out. Make sure large NS set does not loop */ +#define MAX_SENT_COUNT 32 +/** at what query-sent-count to stop target fetch policy */ +#define TARGET_FETCH_STOP 3 +/** how nice is a server without further information, in msec + * Equals rtt initial timeout value. + */ +#define UNKNOWN_SERVER_NICENESS 376 +/** maximum timeout before a host is deemed unsuitable, in msec. + * After host_ttl this will be timed out and the host will be tried again. + * Equals RTT_MAX_TIMEOUT + */ +#define USEFUL_SERVER_TOP_TIMEOUT 120000 +/** number of retries on outgoing queries */ +#define OUTBOUND_MSG_RETRY 5 +/** RTT band, within this amount from the best, servers are chosen randomly. + * Chosen so that the UNKNOWN_SERVER_NICENESS falls within the band of a + * fast server, this causes server exploration as a side benefit. msec. */ +#define RTT_BAND 400 +/** Start value for blacklisting a host, 2*USEFUL_SERVER_TOP_TIMEOUT in sec */ +#define INFRA_BACKOFF_INITIAL 240 + +/** + * Global state for the iterator. + */ +struct iter_env { + /** A flag to indicate whether or not we have an IPv6 route */ + int supports_ipv6; + + /** A flag to indicate whether or not we have an IPv4 route */ + int supports_ipv4; + + /** A set of inetaddrs that should never be queried. */ + struct iter_donotq* donotq; + + /** private address space and private domains */ + struct iter_priv* priv; + + /** The maximum dependency depth that this resolver will pursue. */ + int max_dependency_depth; + + /** + * The target fetch policy for each dependency level. This is + * described as a simple number (per dependency level): + * negative numbers (usually just -1) mean fetch-all, + * 0 means only fetch on demand, and + * positive numbers mean to fetch at most that many targets. + * array of max_dependency_depth+1 size. + */ + int* target_fetch_policy; +}; + +/** + * State of the iterator for a query. + */ +enum iter_state { + /** + * Externally generated queries start at this state. Query restarts are + * reset to this state. + */ + INIT_REQUEST_STATE = 0, + + /** + * Root priming events reactivate here, most other events pass + * through this naturally as the 2nd part of the INIT_REQUEST_STATE. + */ + INIT_REQUEST_2_STATE, + + /** + * Stub priming events reactivate here, most other events pass + * through this naturally as the 3rd part of the INIT_REQUEST_STATE. + */ + INIT_REQUEST_3_STATE, + + /** + * Each time a delegation point changes for a given query or a + * query times out and/or wakes up, this state is (re)visited. + * This state is reponsible for iterating through a list of + * nameserver targets. + */ + QUERYTARGETS_STATE, + + /** + * Responses to queries start at this state. This state handles + * the decision tree associated with handling responses. + */ + QUERY_RESP_STATE, + + /** Responses to priming queries finish at this state. */ + PRIME_RESP_STATE, + + /** Collecting query class information, for qclass=ANY, when + * it spawns off queries for every class, it returns here. */ + COLLECT_CLASS_STATE, + + /** Find NS record to resolve DS record from, walking to the right + * NS spot until we find it */ + DSNS_FIND_STATE, + + /** Responses that are to be returned upstream end at this state. + * As well as responses to target queries. */ + FINISHED_STATE +}; + +/** + * Per query state for the iterator module. + */ +struct iter_qstate { + /** + * State of the iterator module. + * This is the state that event is in or should sent to -- all + * requests should start with the INIT_REQUEST_STATE. All + * responses should start with QUERY_RESP_STATE. Subsequent + * processing of the event will change this state. + */ + enum iter_state state; + + /** + * Final state for the iterator module. + * This is the state that responses should be routed to once the + * response is final. For externally initiated queries, this + * will be FINISHED_STATE, locally initiated queries will have + * different final states. + */ + enum iter_state final_state; + + /** + * The depth of this query, this means the depth of recursion. + * This address is needed for another query, which is an address + * needed for another query, etc. Original client query has depth 0. + */ + int depth; + + /** + * The response + */ + struct dns_msg* response; + + /** + * This is a list of RRsets that must be prepended to the + * ANSWER section of a response before being sent upstream. + */ + struct iter_prep_list* an_prepend_list; + /** Last element of the prepend list */ + struct iter_prep_list* an_prepend_last; + + /** + * This is the list of RRsets that must be prepended to the + * AUTHORITY section of the response before being sent upstream. + */ + struct iter_prep_list* ns_prepend_list; + /** Last element of the authority prepend list */ + struct iter_prep_list* ns_prepend_last; + + /** query name used for chasing the results. Initially the same as + * the state qinfo, but after CNAMEs this will be different. + * The query info used to elicit the results needed. */ + struct query_info qchase; + /** query flags to use when chasing the answer (i.e. RD flag) */ + uint16_t chase_flags; + /** true if we set RD bit because of last resort recursion lame query*/ + int chase_to_rd; + + /** + * This is the current delegation point for an in-progress query. This + * object retains state as to which delegation targets need to be + * (sub)queried for vs which ones have already been visited. + */ + struct delegpt* dp; + + /** state for 0x20 fallback when capsfail happens, 0 not a fallback */ + int caps_fallback; + /** state for capsfail: current server number to try */ + size_t caps_server; + /** state for capsfail: stored query for comparisons. Can be NULL if + * no response had been seen prior to starting the fallback. */ + struct reply_info* caps_reply; + + /** Current delegation message - returned for non-RD queries */ + struct dns_msg* deleg_msg; + + /** number of outstanding target sub queries */ + int num_target_queries; + + /** outstanding direct queries */ + int num_current_queries; + + /** the number of times this query has been restarted. */ + int query_restart_count; + + /** the number of times this query as followed a referral. */ + int referral_count; + + /** number of queries fired off */ + int sent_count; + + /** + * The query must store NS records from referrals as parentside RRs + * Enabled once it hits resolution problems, to throttle retries. + * If enabled it is the pointer to the old delegation point with + * the old retry counts for bad-nameserver-addresses. + */ + struct delegpt* store_parent_NS; + + /** + * The query is for parent-side glue(A or AAAA) for a nameserver. + * If the item is seen as glue in a referral, and pside_glue is NULL, + * then it is stored in pside_glue for later. + * If it was never seen, at the end, then a negative caching element + * must be created. + * The (data or negative) RR cache element then throttles retries. + */ + int query_for_pside_glue; + /** the parent-side-glue element (NULL if none, its first match) */ + struct ub_packed_rrset_key* pside_glue; + + /** If nonNULL we are walking upwards from DS query to find NS */ + uint8_t* dsns_point; + /** length of the dname in dsns_point */ + size_t dsns_point_len; + + /** + * expected dnssec information for this iteration step. + * If dnssec rrsigs are expected and not given, the server is marked + * lame (dnssec-lame). + */ + int dnssec_expected; + + /** + * We are expecting dnssec information, but we also know the server + * is DNSSEC lame. The response need not be marked dnssec-lame again. + */ + int dnssec_lame_query; + + /** + * This is flag that, if true, means that this event is + * waiting for a stub priming query. + */ + int wait_priming_stub; + + /** + * This is a flag that, if true, means that this query is + * for (re)fetching glue from a zone. Since the address should + * have been glue, query again to the servers that should have + * been returning it as glue. + * The delegation point must be set to the one that should *not* + * be used when creating the state. A higher one will be attempted. + */ + int refetch_glue; + + /** list of pending queries to authoritative servers. */ + struct outbound_list outlist; +}; + +/** + * List of prepend items + */ +struct iter_prep_list { + /** next in list */ + struct iter_prep_list* next; + /** rrset */ + struct ub_packed_rrset_key* rrset; +}; + +/** + * Get the iterator function block. + * @return: function block with function pointers to iterator methods. + */ +struct module_func_block* iter_get_funcblock(void); + +/** + * Get iterator state as a string + * @param state: to convert + * @return constant string that is printable. + */ +const char* iter_state_to_string(enum iter_state state); + +/** + * See if iterator state is a response state + * @param s: to inspect + * @return true if response state. + */ +int iter_state_is_responsestate(enum iter_state s); + +/** iterator init */ +int iter_init(struct module_env* env, int id); + +/** iterator deinit */ +void iter_deinit(struct module_env* env, int id); + +/** iterator operate on a query */ +void iter_operate(struct module_qstate* qstate, enum module_ev event, int id, + struct outbound_entry* outbound); + +/** + * Return priming query results to interestes super querystates. + * + * Sets the delegation point and delegation message (not nonRD queries). + * This is a callback from walk_supers. + * + * @param qstate: query state that finished. + * @param id: module id. + * @param super: the qstate to inform. + */ +void iter_inform_super(struct module_qstate* qstate, int id, + struct module_qstate* super); + +/** iterator cleanup query state */ +void iter_clear(struct module_qstate* qstate, int id); + +/** iterator alloc size routine */ +size_t iter_get_mem(struct module_env* env, int id); + +#endif /* ITERATOR_ITERATOR_H */ |