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Diffstat (limited to 'external/unbound/util/data/msgparse.c')
| -rw-r--r-- | external/unbound/util/data/msgparse.c | 1093 |
1 files changed, 0 insertions, 1093 deletions
diff --git a/external/unbound/util/data/msgparse.c b/external/unbound/util/data/msgparse.c deleted file mode 100644 index 5381500e1..000000000 --- a/external/unbound/util/data/msgparse.c +++ /dev/null @@ -1,1093 +0,0 @@ -/* - * util/data/msgparse.c - parse wireformat DNS messages. - * - * 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 - * Routines for message parsing a packet buffer to a descriptive structure. - */ -#include "config.h" -#include "util/data/msgparse.h" -#include "util/data/msgreply.h" -#include "util/data/dname.h" -#include "util/data/packed_rrset.h" -#include "util/storage/lookup3.h" -#include "util/regional.h" -#include "sldns/rrdef.h" -#include "sldns/sbuffer.h" -#include "sldns/parseutil.h" -#include "sldns/wire2str.h" - -/** smart comparison of (compressed, valid) dnames from packet */ -static int -smart_compare(sldns_buffer* pkt, uint8_t* dnow, - uint8_t* dprfirst, uint8_t* dprlast) -{ - if(LABEL_IS_PTR(*dnow)) { - /* ptr points to a previous dname */ - uint8_t* p = sldns_buffer_at(pkt, PTR_OFFSET(dnow[0], dnow[1])); - if( p == dprfirst || p == dprlast ) - return 0; - /* prev dname is also a ptr, both ptrs are the same. */ - if(LABEL_IS_PTR(*dprlast) && - dprlast[0] == dnow[0] && dprlast[1] == dnow[1]) - return 0; - } - return dname_pkt_compare(pkt, dnow, dprlast); -} - -/** - * Allocate new rrset in region, fill with data. - */ -static struct rrset_parse* -new_rrset(struct msg_parse* msg, uint8_t* dname, size_t dnamelen, - uint16_t type, uint16_t dclass, hashvalue_type hash, - uint32_t rrset_flags, sldns_pkt_section section, - struct regional* region) -{ - struct rrset_parse* p = regional_alloc(region, sizeof(*p)); - if(!p) return NULL; - p->rrset_bucket_next = msg->hashtable[hash & (PARSE_TABLE_SIZE-1)]; - msg->hashtable[hash & (PARSE_TABLE_SIZE-1)] = p; - p->rrset_all_next = 0; - if(msg->rrset_last) - msg->rrset_last->rrset_all_next = p; - else msg->rrset_first = p; - msg->rrset_last = p; - p->hash = hash; - p->section = section; - p->dname = dname; - p->dname_len = dnamelen; - p->type = type; - p->rrset_class = dclass; - p->flags = rrset_flags; - p->rr_count = 0; - p->size = 0; - p->rr_first = 0; - p->rr_last = 0; - p->rrsig_count = 0; - p->rrsig_first = 0; - p->rrsig_last = 0; - return p; -} - -/** See if next rrset is nsec at zone apex */ -static int -nsec_at_apex(sldns_buffer* pkt) -{ - /* we are at ttl position in packet. */ - size_t pos = sldns_buffer_position(pkt); - uint16_t rdatalen; - if(sldns_buffer_remaining(pkt) < 7) /* ttl+len+root */ - return 0; /* eek! */ - sldns_buffer_skip(pkt, 4); /* ttl */; - rdatalen = sldns_buffer_read_u16(pkt); - if(sldns_buffer_remaining(pkt) < rdatalen) { - sldns_buffer_set_position(pkt, pos); - return 0; /* parse error happens later */ - } - /* must validate the nsec next domain name format */ - if(pkt_dname_len(pkt) == 0) { - sldns_buffer_set_position(pkt, pos); - return 0; /* parse error */ - } - - /* see if SOA bit is set. */ - if(sldns_buffer_position(pkt) < pos+4+rdatalen) { - /* nsec type bitmap contains items */ - uint8_t win, blen, bits; - /* need: windownum, bitmap len, firstbyte */ - if(sldns_buffer_position(pkt)+3 > pos+4+rdatalen) { - sldns_buffer_set_position(pkt, pos); - return 0; /* malformed nsec */ - } - win = sldns_buffer_read_u8(pkt); - blen = sldns_buffer_read_u8(pkt); - bits = sldns_buffer_read_u8(pkt); - /* 0window always first window. bitlen >=1 or parse - error really. bit 0x2 is SOA. */ - if(win == 0 && blen >= 1 && (bits & 0x02)) { - sldns_buffer_set_position(pkt, pos); - return 1; - } - } - - sldns_buffer_set_position(pkt, pos); - return 0; -} - -/** Calculate rrset flags */ -static uint32_t -pkt_rrset_flags(sldns_buffer* pkt, uint16_t type, sldns_pkt_section sec) -{ - uint32_t f = 0; - if(type == LDNS_RR_TYPE_NSEC && nsec_at_apex(pkt)) { - f |= PACKED_RRSET_NSEC_AT_APEX; - } else if(type == LDNS_RR_TYPE_SOA && sec == LDNS_SECTION_AUTHORITY) { - f |= PACKED_RRSET_SOA_NEG; - } - return f; -} - -hashvalue_type -pkt_hash_rrset(sldns_buffer* pkt, uint8_t* dname, uint16_t type, - uint16_t dclass, uint32_t rrset_flags) -{ - /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ - /* this routine handles compressed names */ - hashvalue_type h = 0xab; - h = dname_pkt_hash(pkt, dname, h); - h = hashlittle(&type, sizeof(type), h); /* host order */ - h = hashlittle(&dclass, sizeof(dclass), h); /* netw order */ - h = hashlittle(&rrset_flags, sizeof(uint32_t), h); - return h; -} - -/** create partial dname hash for rrset hash */ -static hashvalue_type -pkt_hash_rrset_first(sldns_buffer* pkt, uint8_t* dname) -{ - /* works together with pkt_hash_rrset_rest */ - /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ - /* this routine handles compressed names */ - hashvalue_type h = 0xab; - h = dname_pkt_hash(pkt, dname, h); - return h; -} - -/** create a rrset hash from a partial dname hash */ -static hashvalue_type -pkt_hash_rrset_rest(hashvalue_type dname_h, uint16_t type, uint16_t dclass, - uint32_t rrset_flags) -{ - /* works together with pkt_hash_rrset_first */ - /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ - hashvalue_type h; - h = hashlittle(&type, sizeof(type), dname_h); /* host order */ - h = hashlittle(&dclass, sizeof(dclass), h); /* netw order */ - h = hashlittle(&rrset_flags, sizeof(uint32_t), h); - return h; -} - -/** compare rrset_parse with data */ -static int -rrset_parse_equals(struct rrset_parse* p, sldns_buffer* pkt, hashvalue_type h, - uint32_t rrset_flags, uint8_t* dname, size_t dnamelen, - uint16_t type, uint16_t dclass) -{ - if(p->hash == h && p->dname_len == dnamelen && p->type == type && - p->rrset_class == dclass && p->flags == rrset_flags && - dname_pkt_compare(pkt, dname, p->dname) == 0) - return 1; - return 0; -} - - -struct rrset_parse* -msgparse_hashtable_lookup(struct msg_parse* msg, sldns_buffer* pkt, - hashvalue_type h, uint32_t rrset_flags, uint8_t* dname, - size_t dnamelen, uint16_t type, uint16_t dclass) -{ - struct rrset_parse* p = msg->hashtable[h & (PARSE_TABLE_SIZE-1)]; - while(p) { - if(rrset_parse_equals(p, pkt, h, rrset_flags, dname, dnamelen, - type, dclass)) - return p; - p = p->rrset_bucket_next; - } - return NULL; -} - -/** return type networkformat that rrsig in packet covers */ -static int -pkt_rrsig_covered(sldns_buffer* pkt, uint8_t* here, uint16_t* type) -{ - size_t pos = sldns_buffer_position(pkt); - sldns_buffer_set_position(pkt, (size_t)(here-sldns_buffer_begin(pkt))); - /* ttl + len + size of small rrsig(rootlabel, no signature) */ - if(sldns_buffer_remaining(pkt) < 4+2+19) - return 0; - sldns_buffer_skip(pkt, 4); /* ttl */ - if(sldns_buffer_read_u16(pkt) < 19) /* too short */ { - sldns_buffer_set_position(pkt, pos); - return 0; - } - *type = sldns_buffer_read_u16(pkt); - sldns_buffer_set_position(pkt, pos); - return 1; -} - -/** true if covered type equals prevtype */ -static int -pkt_rrsig_covered_equals(sldns_buffer* pkt, uint8_t* here, uint16_t type) -{ - uint16_t t; - if(pkt_rrsig_covered(pkt, here, &t) && t == type) - return 1; - return 0; -} - -void -msgparse_bucket_remove(struct msg_parse* msg, struct rrset_parse* rrset) -{ - struct rrset_parse** p; - p = &msg->hashtable[ rrset->hash & (PARSE_TABLE_SIZE-1) ]; - while(*p) { - if(*p == rrset) { - *p = rrset->rrset_bucket_next; - return; - } - p = &( (*p)->rrset_bucket_next ); - } -} - -/** change section of rrset from previous to current section */ -static void -change_section(struct msg_parse* msg, struct rrset_parse* rrset, - sldns_pkt_section section) -{ - struct rrset_parse *p, *prev; - /* remove from list */ - if(section == rrset->section) - return; - p = msg->rrset_first; - prev = 0; - while(p) { - if(p == rrset) { - if(prev) prev->rrset_all_next = p->rrset_all_next; - else msg->rrset_first = p->rrset_all_next; - if(msg->rrset_last == rrset) - msg->rrset_last = prev; - break; - } - prev = p; - p = p->rrset_all_next; - } - /* remove from 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); - } - /* insert at end of list */ - rrset->rrset_all_next = 0; - if(msg->rrset_last) - msg->rrset_last->rrset_all_next = rrset; - else msg->rrset_first = rrset; - msg->rrset_last = rrset; - /* up count of new section */ - switch(section) { - case LDNS_SECTION_AUTHORITY: msg->ns_rrsets++; break; - case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets++; break; - default: log_assert(0); - } - rrset->section = section; -} - -/** see if rrset of type RRSIG contains sig over given type */ -static int -rrset_has_sigover(sldns_buffer* pkt, struct rrset_parse* rrset, uint16_t type, - int* hasother) -{ - int res = 0; - struct rr_parse* rr = rrset->rr_first; - log_assert( rrset->type == LDNS_RR_TYPE_RRSIG ); - while(rr) { - if(pkt_rrsig_covered_equals(pkt, rr->ttl_data, type)) - res = 1; - else *hasother = 1; - rr = rr->next; - } - return res; -} - -/** move rrsigs from sigset to dataset */ -static int -moveover_rrsigs(sldns_buffer* pkt, struct regional* region, - struct rrset_parse* sigset, struct rrset_parse* dataset, int duplicate) -{ - struct rr_parse* sig = sigset->rr_first; - struct rr_parse* prev = NULL; - struct rr_parse* insert; - struct rr_parse* nextsig; - while(sig) { - nextsig = sig->next; - if(pkt_rrsig_covered_equals(pkt, sig->ttl_data, - dataset->type)) { - if(duplicate) { - /* new */ - insert = (struct rr_parse*)regional_alloc( - region, sizeof(struct rr_parse)); - if(!insert) return 0; - insert->outside_packet = 0; - insert->ttl_data = sig->ttl_data; - insert->size = sig->size; - /* prev not used */ - } else { - /* remove from sigset */ - if(prev) prev->next = sig->next; - else sigset->rr_first = sig->next; - if(sigset->rr_last == sig) - sigset->rr_last = prev; - sigset->rr_count--; - sigset->size -= sig->size; - insert = sig; - /* prev not changed */ - } - /* add to dataset */ - dataset->rrsig_count++; - insert->next = 0; - if(dataset->rrsig_last) - dataset->rrsig_last->next = insert; - else dataset->rrsig_first = insert; - dataset->rrsig_last = insert; - dataset->size += insert->size; - } else { - prev = sig; - } - sig = nextsig; - } - return 1; -} - -/** change an rrsig rrset for use as data rrset */ -static struct rrset_parse* -change_rrsig_rrset(struct rrset_parse* sigset, struct msg_parse* msg, - sldns_buffer* pkt, uint16_t datatype, uint32_t rrset_flags, - int hasother, sldns_pkt_section section, struct regional* region) -{ - struct rrset_parse* dataset = sigset; - hashvalue_type hash = pkt_hash_rrset(pkt, sigset->dname, datatype, - sigset->rrset_class, rrset_flags); - log_assert( sigset->type == LDNS_RR_TYPE_RRSIG ); - log_assert( datatype != LDNS_RR_TYPE_RRSIG ); - if(hasother) { - /* need to make new rrset to hold data type */ - dataset = new_rrset(msg, sigset->dname, sigset->dname_len, - datatype, sigset->rrset_class, hash, rrset_flags, - section, region); - if(!dataset) - return NULL; - switch(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); - } - if(!moveover_rrsigs(pkt, region, sigset, dataset, - msg->qtype == LDNS_RR_TYPE_RRSIG || - (msg->qtype == LDNS_RR_TYPE_ANY && - section != LDNS_SECTION_ANSWER) )) - return NULL; - return dataset; - } - /* changeover the type of the rrset to data set */ - msgparse_bucket_remove(msg, dataset); - /* insert into new hash bucket */ - dataset->rrset_bucket_next = msg->hashtable[hash&(PARSE_TABLE_SIZE-1)]; - msg->hashtable[hash&(PARSE_TABLE_SIZE-1)] = dataset; - dataset->hash = hash; - /* use section of data item for result */ - change_section(msg, dataset, section); - dataset->type = datatype; - dataset->flags = rrset_flags; - dataset->rrsig_count += dataset->rr_count; - dataset->rr_count = 0; - /* move sigs to end of siglist */ - if(dataset->rrsig_last) - dataset->rrsig_last->next = dataset->rr_first; - else dataset->rrsig_first = dataset->rr_first; - dataset->rrsig_last = dataset->rr_last; - dataset->rr_first = 0; - dataset->rr_last = 0; - return dataset; -} - -/** Find rrset. If equal to previous it is fast. hash if not so. - * @param msg: the message with hash table. - * @param pkt: the packet in wireformat (needed for compression ptrs). - * @param dname: pointer to start of dname (compressed) in packet. - * @param dnamelen: uncompressed wirefmt length of dname. - * @param type: type of current rr. - * @param dclass: class of current rr. - * @param hash: hash value is returned if the rrset could not be found. - * @param rrset_flags: is returned if the rrset could not be found. - * @param prev_dname_first: dname of last seen RR. First seen dname. - * @param prev_dname_last: dname of last seen RR. Last seen dname. - * @param prev_dnamelen: dname len of last seen RR. - * @param prev_type: type of last seen RR. - * @param prev_dclass: class of last seen RR. - * @param rrset_prev: last seen RRset. - * @param section: the current section in the packet. - * @param region: used to allocate temporary parsing data. - * @return 0 on out of memory. - */ -static int -find_rrset(struct msg_parse* msg, sldns_buffer* pkt, uint8_t* dname, - size_t dnamelen, uint16_t type, uint16_t dclass, hashvalue_type* hash, - uint32_t* rrset_flags, - uint8_t** prev_dname_first, uint8_t** prev_dname_last, - size_t* prev_dnamelen, uint16_t* prev_type, - uint16_t* prev_dclass, struct rrset_parse** rrset_prev, - sldns_pkt_section section, struct regional* region) -{ - hashvalue_type dname_h = pkt_hash_rrset_first(pkt, dname); - uint16_t covtype; - if(*rrset_prev) { - /* check if equal to previous item */ - if(type == *prev_type && dclass == *prev_dclass && - dnamelen == *prev_dnamelen && - smart_compare(pkt, dname, *prev_dname_first, - *prev_dname_last) == 0 && - type != LDNS_RR_TYPE_RRSIG) { - /* same as previous */ - *prev_dname_last = dname; - return 1; - } - /* check if rrsig over previous item */ - if(type == LDNS_RR_TYPE_RRSIG && dclass == *prev_dclass && - pkt_rrsig_covered_equals(pkt, sldns_buffer_current(pkt), - *prev_type) && - smart_compare(pkt, dname, *prev_dname_first, - *prev_dname_last) == 0) { - /* covers previous */ - *prev_dname_last = dname; - return 1; - } - } - /* find by hashing and lookup in hashtable */ - *rrset_flags = pkt_rrset_flags(pkt, type, section); - - /* if rrsig - try to lookup matching data set first */ - if(type == LDNS_RR_TYPE_RRSIG && pkt_rrsig_covered(pkt, - sldns_buffer_current(pkt), &covtype)) { - *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, - *rrset_flags); - *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, - *rrset_flags, dname, dnamelen, covtype, dclass); - if(!*rrset_prev && covtype == LDNS_RR_TYPE_NSEC) { - /* if NSEC try with NSEC apex bit twiddled */ - *rrset_flags ^= PACKED_RRSET_NSEC_AT_APEX; - *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, - *rrset_flags); - *rrset_prev = msgparse_hashtable_lookup(msg, pkt, - *hash, *rrset_flags, dname, dnamelen, covtype, - dclass); - if(!*rrset_prev) /* untwiddle if not found */ - *rrset_flags ^= PACKED_RRSET_NSEC_AT_APEX; - } - if(!*rrset_prev && covtype == LDNS_RR_TYPE_SOA) { - /* if SOA try with SOA neg flag twiddled */ - *rrset_flags ^= PACKED_RRSET_SOA_NEG; - *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, - *rrset_flags); - *rrset_prev = msgparse_hashtable_lookup(msg, pkt, - *hash, *rrset_flags, dname, dnamelen, covtype, - dclass); - if(!*rrset_prev) /* untwiddle if not found */ - *rrset_flags ^= PACKED_RRSET_SOA_NEG; - } - if(*rrset_prev) { - *prev_dname_first = (*rrset_prev)->dname; - *prev_dname_last = dname; - *prev_dnamelen = dnamelen; - *prev_type = covtype; - *prev_dclass = dclass; - return 1; - } - } - if(type != LDNS_RR_TYPE_RRSIG) { - int hasother = 0; - /* find matching rrsig */ - *hash = pkt_hash_rrset_rest(dname_h, LDNS_RR_TYPE_RRSIG, - dclass, 0); - *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, - 0, dname, dnamelen, LDNS_RR_TYPE_RRSIG, - dclass); - if(*rrset_prev && rrset_has_sigover(pkt, *rrset_prev, type, - &hasother)) { - /* yes! */ - *prev_dname_first = (*rrset_prev)->dname; - *prev_dname_last = dname; - *prev_dnamelen = dnamelen; - *prev_type = type; - *prev_dclass = dclass; - *rrset_prev = change_rrsig_rrset(*rrset_prev, msg, - pkt, type, *rrset_flags, hasother, section, - region); - if(!*rrset_prev) return 0; - return 1; - } - } - - *hash = pkt_hash_rrset_rest(dname_h, type, dclass, *rrset_flags); - *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, *rrset_flags, - dname, dnamelen, type, dclass); - if(*rrset_prev) - *prev_dname_first = (*rrset_prev)->dname; - else *prev_dname_first = dname; - *prev_dname_last = dname; - *prev_dnamelen = dnamelen; - *prev_type = type; - *prev_dclass = dclass; - return 1; -} - -/** - * Parse query section. - * @param pkt: packet, position at call must be at start of query section. - * at end position is after query section. - * @param msg: store results here. - * @return: 0 if OK, or rcode on error. - */ -static int -parse_query_section(sldns_buffer* pkt, struct msg_parse* msg) -{ - if(msg->qdcount == 0) - return 0; - if(msg->qdcount > 1) - return LDNS_RCODE_FORMERR; - log_assert(msg->qdcount == 1); - if(sldns_buffer_remaining(pkt) <= 0) - return LDNS_RCODE_FORMERR; - msg->qname = sldns_buffer_current(pkt); - if((msg->qname_len = pkt_dname_len(pkt)) == 0) - return LDNS_RCODE_FORMERR; - if(sldns_buffer_remaining(pkt) < sizeof(uint16_t)*2) - return LDNS_RCODE_FORMERR; - msg->qtype = sldns_buffer_read_u16(pkt); - msg->qclass = sldns_buffer_read_u16(pkt); - return 0; -} - -size_t -get_rdf_size(sldns_rdf_type rdf) -{ - switch(rdf) { - case LDNS_RDF_TYPE_CLASS: - case LDNS_RDF_TYPE_ALG: - case LDNS_RDF_TYPE_INT8: - return 1; - break; - case LDNS_RDF_TYPE_INT16: - case LDNS_RDF_TYPE_TYPE: - case LDNS_RDF_TYPE_CERT_ALG: - return 2; - break; - case LDNS_RDF_TYPE_INT32: - case LDNS_RDF_TYPE_TIME: - case LDNS_RDF_TYPE_A: - case LDNS_RDF_TYPE_PERIOD: - return 4; - break; - case LDNS_RDF_TYPE_TSIGTIME: - return 6; - break; - case LDNS_RDF_TYPE_AAAA: - return 16; - break; - default: - log_assert(0); /* add type above */ - /* only types that appear before a domain * - * name are needed. rest is simply copied. */ - } - return 0; -} - -/** calculate the size of one rr */ -static int -calc_size(sldns_buffer* pkt, uint16_t type, struct rr_parse* rr) -{ - const sldns_rr_descriptor* desc; - uint16_t pkt_len; /* length of rr inside the packet */ - rr->size = sizeof(uint16_t); /* the rdatalen */ - sldns_buffer_skip(pkt, 4); /* skip ttl */ - pkt_len = sldns_buffer_read_u16(pkt); - if(sldns_buffer_remaining(pkt) < pkt_len) - return 0; - desc = sldns_rr_descript(type); - if(pkt_len > 0 && desc && desc->_dname_count > 0) { - int count = (int)desc->_dname_count; - int rdf = 0; - size_t len; - size_t oldpos; - /* skip first part. */ - while(pkt_len > 0 && count) { - switch(desc->_wireformat[rdf]) { - case LDNS_RDF_TYPE_DNAME: - /* decompress every domain name */ - oldpos = sldns_buffer_position(pkt); - if((len = pkt_dname_len(pkt)) == 0) - return 0; /* malformed dname */ - if(sldns_buffer_position(pkt)-oldpos > pkt_len) - return 0; /* dname exceeds rdata */ - pkt_len -= sldns_buffer_position(pkt)-oldpos; - rr->size += len; - count--; - len = 0; - break; - case LDNS_RDF_TYPE_STR: - if(pkt_len < 1) { - /* NOTREACHED, due to 'while(>0)' */ - return 0; /* len byte exceeds rdata */ - } - len = sldns_buffer_current(pkt)[0] + 1; - break; - default: - len = get_rdf_size(desc->_wireformat[rdf]); - } - if(len) { - if(pkt_len < len) - return 0; /* exceeds rdata */ - pkt_len -= len; - sldns_buffer_skip(pkt, (ssize_t)len); - rr->size += len; - } - rdf++; - } - } - /* remaining rdata */ - rr->size += pkt_len; - sldns_buffer_skip(pkt, (ssize_t)pkt_len); - return 1; -} - -/** skip rr ttl and rdata */ -static int -skip_ttl_rdata(sldns_buffer* pkt) -{ - uint16_t rdatalen; - if(sldns_buffer_remaining(pkt) < 6) /* ttl + rdatalen */ - return 0; - sldns_buffer_skip(pkt, 4); /* ttl */ - rdatalen = sldns_buffer_read_u16(pkt); - if(sldns_buffer_remaining(pkt) < rdatalen) - return 0; - sldns_buffer_skip(pkt, (ssize_t)rdatalen); - return 1; -} - -/** see if RRSIG is a duplicate of another */ -static int -sig_is_double(sldns_buffer* pkt, struct rrset_parse* rrset, uint8_t* ttldata) -{ - uint16_t rlen, siglen; - size_t pos = sldns_buffer_position(pkt); - struct rr_parse* sig; - if(sldns_buffer_remaining(pkt) < 6) - return 0; - sldns_buffer_skip(pkt, 4); /* ttl */ - rlen = sldns_buffer_read_u16(pkt); - if(sldns_buffer_remaining(pkt) < rlen) { - sldns_buffer_set_position(pkt, pos); - return 0; - } - sldns_buffer_set_position(pkt, pos); - - sig = rrset->rrsig_first; - while(sig) { - /* check if rdatalen is same */ - memmove(&siglen, sig->ttl_data+4, sizeof(siglen)); - siglen = ntohs(siglen); - /* checks if data in packet is exactly the same, this means - * also dname in rdata is the same, but rrsig is not allowed - * to have compressed dnames anyway. If it is compressed anyway - * it will lead to duplicate rrs for qtype=RRSIG. (or ANY). - * - * Cannot use sig->size because size of the other one is not - * calculated yet. - */ - if(siglen == rlen) { - if(siglen>0 && memcmp(sig->ttl_data+6, ttldata+6, - siglen) == 0) { - /* same! */ - return 1; - } - } - sig = sig->next; - } - return 0; -} - -/** Add rr (from packet here) to rrset, skips rr */ -static int -add_rr_to_rrset(struct rrset_parse* rrset, sldns_buffer* pkt, - struct msg_parse* msg, struct regional* region, - sldns_pkt_section section, uint16_t type) -{ - struct rr_parse* rr; - /* check section of rrset. */ - if(rrset->section != section && type != LDNS_RR_TYPE_RRSIG && - rrset->type != LDNS_RR_TYPE_RRSIG) { - /* silently drop it - we drop the last part, since - * trust in rr data depends on the section it is in. - * the less trustworthy part is discarded. - * also the last part is more likely to be incomplete. - * RFC 2181: must put RRset only once in response. */ - /* - verbose(VERB_QUERY, "Packet contains rrset data in " - "multiple sections, dropped last part."); - log_buf(VERB_QUERY, "packet was", pkt); - */ - /* forwards */ - if(!skip_ttl_rdata(pkt)) - return LDNS_RCODE_FORMERR; - return 0; - } - - if( (msg->qtype == LDNS_RR_TYPE_RRSIG || - msg->qtype == LDNS_RR_TYPE_ANY) - && sig_is_double(pkt, rrset, sldns_buffer_current(pkt))) { - if(!skip_ttl_rdata(pkt)) - return LDNS_RCODE_FORMERR; - return 0; - } - - /* create rr */ - if(!(rr = (struct rr_parse*)regional_alloc(region, sizeof(*rr)))) - return LDNS_RCODE_SERVFAIL; - rr->outside_packet = 0; - rr->ttl_data = sldns_buffer_current(pkt); - rr->next = 0; - if(type == LDNS_RR_TYPE_RRSIG && rrset->type != LDNS_RR_TYPE_RRSIG) { - if(rrset->rrsig_last) - rrset->rrsig_last->next = rr; - else rrset->rrsig_first = rr; - rrset->rrsig_last = rr; - rrset->rrsig_count++; - } else { - if(rrset->rr_last) - rrset->rr_last->next = rr; - else rrset->rr_first = rr; - rrset->rr_last = rr; - rrset->rr_count++; - } - - /* calc decompressed size */ - if(!calc_size(pkt, type, rr)) - return LDNS_RCODE_FORMERR; - rrset->size += rr->size; - - return 0; -} - -/** - * Parse packet RR section, for answer, authority and additional sections. - * @param pkt: packet, position at call must be at start of section. - * at end position is after section. - * @param msg: store results here. - * @param region: how to alloc results. - * @param section: section enum. - * @param num_rrs: how many rrs are in the section. - * @param num_rrsets: returns number of rrsets in the section. - * @return: 0 if OK, or rcode on error. - */ -static int -parse_section(sldns_buffer* pkt, struct msg_parse* msg, - struct regional* region, sldns_pkt_section section, - uint16_t num_rrs, size_t* num_rrsets) -{ - uint16_t i; - uint8_t* dname, *prev_dname_f = NULL, *prev_dname_l = NULL; - size_t dnamelen, prev_dnamelen = 0; - uint16_t type, prev_type = 0; - uint16_t dclass, prev_dclass = 0; - uint32_t rrset_flags = 0; - hashvalue_type hash = 0; - struct rrset_parse* rrset = NULL; - int r; - - if(num_rrs == 0) - return 0; - if(sldns_buffer_remaining(pkt) <= 0) - return LDNS_RCODE_FORMERR; - for(i=0; i<num_rrs; i++) { - /* parse this RR. */ - dname = sldns_buffer_current(pkt); - if((dnamelen = pkt_dname_len(pkt)) == 0) - return LDNS_RCODE_FORMERR; - if(sldns_buffer_remaining(pkt) < 10) /* type, class, ttl, len */ - return LDNS_RCODE_FORMERR; - type = sldns_buffer_read_u16(pkt); - sldns_buffer_read(pkt, &dclass, sizeof(dclass)); - - if(0) { /* debug show what is being parsed. */ - if(type == LDNS_RR_TYPE_RRSIG) { - uint16_t t; - if(pkt_rrsig_covered(pkt, - sldns_buffer_current(pkt), &t)) - fprintf(stderr, "parse of %s(%d) [%s(%d)]", - sldns_rr_descript(type)? - sldns_rr_descript(type)->_name: "??", - (int)type, - sldns_rr_descript(t)? - sldns_rr_descript(t)->_name: "??", - (int)t); - } else - fprintf(stderr, "parse of %s(%d)", - sldns_rr_descript(type)? - sldns_rr_descript(type)->_name: "??", - (int)type); - fprintf(stderr, " %s(%d) ", - sldns_lookup_by_id(sldns_rr_classes, - (int)ntohs(dclass))?sldns_lookup_by_id( - sldns_rr_classes, (int)ntohs(dclass))->name: - "??", (int)ntohs(dclass)); - dname_print(stderr, pkt, dname); - fprintf(stderr, "\n"); - } - - /* see if it is part of an existing RR set */ - if(!find_rrset(msg, pkt, dname, dnamelen, type, dclass, &hash, - &rrset_flags, &prev_dname_f, &prev_dname_l, - &prev_dnamelen, &prev_type, &prev_dclass, &rrset, - section, region)) - return LDNS_RCODE_SERVFAIL; - if(!rrset) { - /* it is a new RR set. hash&flags already calculated.*/ - (*num_rrsets)++; - rrset = new_rrset(msg, dname, dnamelen, type, dclass, - hash, rrset_flags, section, region); - if(!rrset) - return LDNS_RCODE_SERVFAIL; - } - else if(0) { - fprintf(stderr, "is part of existing: "); - dname_print(stderr, pkt, rrset->dname); - fprintf(stderr, " type %s(%d)\n", - sldns_rr_descript(rrset->type)? - sldns_rr_descript(rrset->type)->_name: "??", - (int)rrset->type); - } - /* add to rrset. */ - if((r=add_rr_to_rrset(rrset, pkt, msg, region, section, - type)) != 0) - return r; - } - return 0; -} - -int -parse_packet(sldns_buffer* pkt, struct msg_parse* msg, struct regional* region) -{ - int ret; - if(sldns_buffer_remaining(pkt) < LDNS_HEADER_SIZE) - return LDNS_RCODE_FORMERR; - /* read the header */ - sldns_buffer_read(pkt, &msg->id, sizeof(uint16_t)); - msg->flags = sldns_buffer_read_u16(pkt); - msg->qdcount = sldns_buffer_read_u16(pkt); - msg->ancount = sldns_buffer_read_u16(pkt); - msg->nscount = sldns_buffer_read_u16(pkt); - msg->arcount = sldns_buffer_read_u16(pkt); - if(msg->qdcount > 1) - return LDNS_RCODE_FORMERR; - if((ret = parse_query_section(pkt, msg)) != 0) - return ret; - if((ret = parse_section(pkt, msg, region, LDNS_SECTION_ANSWER, - msg->ancount, &msg->an_rrsets)) != 0) - return ret; - if((ret = parse_section(pkt, msg, region, LDNS_SECTION_AUTHORITY, - msg->nscount, &msg->ns_rrsets)) != 0) - return ret; - if(sldns_buffer_remaining(pkt) == 0 && msg->arcount == 1) { - /* BIND accepts leniently that an EDNS record is missing. - * so, we do too. */ - } else if((ret = parse_section(pkt, msg, region, - LDNS_SECTION_ADDITIONAL, msg->arcount, &msg->ar_rrsets)) != 0) - return ret; - /* if(sldns_buffer_remaining(pkt) > 0) { */ - /* there is spurious data at end of packet. ignore */ - /* } */ - msg->rrset_count = msg->an_rrsets + msg->ns_rrsets + msg->ar_rrsets; - return 0; -} - -/** parse EDNS options from EDNS wireformat rdata */ -static int -parse_edns_options(uint8_t* rdata_ptr, size_t rdata_len, - struct edns_data* edns, struct regional* region) -{ - /* while still more options, and have code+len to read */ - /* ignores partial content (i.e. rdata len 3) */ - while(rdata_len >= 4) { - uint16_t opt_code = sldns_read_uint16(rdata_ptr); - uint16_t opt_len = sldns_read_uint16(rdata_ptr+2); - rdata_ptr += 4; - rdata_len -= 4; - if(opt_len > rdata_len) - break; /* option code partial */ - if(!edns_opt_append(edns, region, opt_code, opt_len, - rdata_ptr)) { - log_err("out of memory"); - return 0; - } - rdata_ptr += opt_len; - rdata_len -= opt_len; - } - return 1; -} - -int -parse_extract_edns(struct msg_parse* msg, struct edns_data* edns, - struct regional* region) -{ - struct rrset_parse* rrset = msg->rrset_first; - struct rrset_parse* prev = 0; - struct rrset_parse* found = 0; - struct rrset_parse* found_prev = 0; - size_t rdata_len; - uint8_t* rdata_ptr; - /* since the class encodes the UDP size, we cannot use hash table to - * find the EDNS OPT record. Scan the packet. */ - while(rrset) { - if(rrset->type == LDNS_RR_TYPE_OPT) { - /* only one OPT RR allowed. */ - if(found) return LDNS_RCODE_FORMERR; - /* found it! */ - found_prev = prev; - found = rrset; - } - prev = rrset; - rrset = rrset->rrset_all_next; - } - if(!found) { - memset(edns, 0, sizeof(*edns)); - edns->udp_size = 512; - return 0; - } - /* check the found RRset */ - /* most lenient check possible. ignore dname, use last opt */ - if(found->section != LDNS_SECTION_ADDITIONAL) - return LDNS_RCODE_FORMERR; - if(found->rr_count == 0) - return LDNS_RCODE_FORMERR; - if(0) { /* strict checking of dname and RRcount */ - if(found->dname_len != 1 || !found->dname - || found->dname[0] != 0) return LDNS_RCODE_FORMERR; - if(found->rr_count != 1) return LDNS_RCODE_FORMERR; - } - log_assert(found->rr_first && found->rr_last); - - /* remove from packet */ - if(found_prev) found_prev->rrset_all_next = found->rrset_all_next; - else msg->rrset_first = found->rrset_all_next; - if(found == msg->rrset_last) - msg->rrset_last = found_prev; - msg->arcount --; - msg->ar_rrsets --; - msg->rrset_count --; - - /* take the data ! */ - edns->edns_present = 1; - edns->ext_rcode = found->rr_last->ttl_data[0]; - edns->edns_version = found->rr_last->ttl_data[1]; - edns->bits = sldns_read_uint16(&found->rr_last->ttl_data[2]); - edns->udp_size = ntohs(found->rrset_class); - edns->opt_list = NULL; - - /* take the options */ - rdata_len = found->rr_first->size; - rdata_ptr = found->rr_first->ttl_data+6; - if(!parse_edns_options(rdata_ptr, rdata_len, edns, region)) - return 0; - - /* ignore rrsigs */ - - return 0; -} - -int -parse_edns_from_pkt(sldns_buffer* pkt, struct edns_data* edns, - struct regional* region) -{ - size_t rdata_len; - uint8_t* rdata_ptr; - log_assert(LDNS_QDCOUNT(sldns_buffer_begin(pkt)) == 1); - log_assert(LDNS_ANCOUNT(sldns_buffer_begin(pkt)) == 0); - log_assert(LDNS_NSCOUNT(sldns_buffer_begin(pkt)) == 0); - /* check edns section is present */ - if(LDNS_ARCOUNT(sldns_buffer_begin(pkt)) > 1) { - return LDNS_RCODE_FORMERR; - } - if(LDNS_ARCOUNT(sldns_buffer_begin(pkt)) == 0) { - memset(edns, 0, sizeof(*edns)); - edns->udp_size = 512; - return 0; - } - /* domain name must be the root of length 1. */ - if(pkt_dname_len(pkt) != 1) - return LDNS_RCODE_FORMERR; - if(sldns_buffer_remaining(pkt) < 10) /* type, class, ttl, rdatalen */ - return LDNS_RCODE_FORMERR; - if(sldns_buffer_read_u16(pkt) != LDNS_RR_TYPE_OPT) - return LDNS_RCODE_FORMERR; - edns->edns_present = 1; - edns->udp_size = sldns_buffer_read_u16(pkt); /* class is udp size */ - edns->ext_rcode = sldns_buffer_read_u8(pkt); /* ttl used for bits */ - edns->edns_version = sldns_buffer_read_u8(pkt); - edns->bits = sldns_buffer_read_u16(pkt); - edns->opt_list = NULL; - - /* take the options */ - rdata_len = sldns_buffer_read_u16(pkt); - if(sldns_buffer_remaining(pkt) < rdata_len) - return LDNS_RCODE_FORMERR; - rdata_ptr = sldns_buffer_current(pkt); - if(!parse_edns_options(rdata_ptr, rdata_len, edns, region)) - return LDNS_RCODE_SERVFAIL; - - /* ignore rrsigs */ - - return 0; -} - -void -log_edns_opt_list(enum verbosity_value level, const char* info_str, - struct edns_option* list) -{ - if(verbosity >= level && list) { - char str[128], *s; - size_t slen; - verbose(level, "%s", info_str); - while(list) { - s = str; - slen = sizeof(str); - (void)sldns_wire2str_edns_option_print(&s, &slen, list->opt_code, - list->opt_data, list->opt_len); - verbose(level, " %s", str); - list = list->next; - } - } -} |