diff options
Diffstat (limited to 'external/unbound/util/data/msgencode.c')
| -rw-r--r-- | external/unbound/util/data/msgencode.c | 916 |
1 files changed, 0 insertions, 916 deletions
diff --git a/external/unbound/util/data/msgencode.c b/external/unbound/util/data/msgencode.c deleted file mode 100644 index 1f72a03b8..000000000 --- a/external/unbound/util/data/msgencode.c +++ /dev/null @@ -1,916 +0,0 @@ -/* - * util/data/msgencode.c - Encode DNS messages, queries and replies. - * - * 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 routines to encode DNS messages. - */ - -#include "config.h" -#include "util/data/msgencode.h" -#include "util/data/msgreply.h" -#include "util/data/msgparse.h" -#include "util/data/dname.h" -#include "util/log.h" -#include "util/regional.h" -#include "util/net_help.h" -#include "sldns/sbuffer.h" -#include "services/localzone.h" - -/** return code that means the function ran out of memory. negative so it does - * not conflict with DNS rcodes. */ -#define RETVAL_OUTMEM -2 -/** return code that means the data did not fit (completely) in the packet */ -#define RETVAL_TRUNC -4 -/** return code that means all is peachy keen. Equal to DNS rcode NOERROR */ -#define RETVAL_OK 0 - -/** - * Data structure to help domain name compression in outgoing messages. - * A tree of dnames and their offsets in the packet is kept. - * It is kept sorted, not canonical, but by label at least, so that after - * a lookup of a name you know its closest match, and the parent from that - * closest match. These are possible compression targets. - * - * It is a binary tree, not a rbtree or balanced tree, as the effort - * of keeping it balanced probably outweighs usefulness (given typical - * DNS packet size). - */ -struct compress_tree_node { - /** left node in tree, all smaller to this */ - struct compress_tree_node* left; - /** right node in tree, all larger than this */ - struct compress_tree_node* right; - - /** the parent node - not for tree, but zone parent. One less label */ - struct compress_tree_node* parent; - /** the domain name for this node. Pointer to uncompressed memory. */ - uint8_t* dname; - /** number of labels in domain name, kept to help compare func. */ - int labs; - /** offset in packet that points to this dname */ - size_t offset; -}; - -/** - * Find domain name in tree, returns exact and closest match. - * @param tree: root of tree. - * @param dname: pointer to uncompressed dname. - * @param labs: number of labels in domain name. - * @param match: closest or exact match. - * guaranteed to be smaller or equal to the sought dname. - * can be null if the tree is empty. - * @param matchlabels: number of labels that match with closest match. - * can be zero is there is no match. - * @param insertpt: insert location for dname, if not found. - * @return: 0 if no exact match. - */ -static int -compress_tree_search(struct compress_tree_node** tree, uint8_t* dname, - int labs, struct compress_tree_node** match, int* matchlabels, - struct compress_tree_node*** insertpt) -{ - int c, n, closen=0; - struct compress_tree_node* p = *tree; - struct compress_tree_node* close = 0; - struct compress_tree_node** prev = tree; - while(p) { - if((c = dname_lab_cmp(dname, labs, p->dname, p->labs, &n)) - == 0) { - *matchlabels = n; - *match = p; - return 1; - } - if(c<0) { - prev = &p->left; - p = p->left; - } else { - closen = n; - close = p; /* p->dname is smaller than dname */ - prev = &p->right; - p = p->right; - } - } - *insertpt = prev; - *matchlabels = closen; - *match = close; - return 0; -} - -/** - * Lookup a domain name in compression tree. - * @param tree: root of tree (not the node with '.'). - * @param dname: pointer to uncompressed dname. - * @param labs: number of labels in domain name. - * @param insertpt: insert location for dname, if not found. - * @return: 0 if not found or compress treenode with best compression. - */ -static struct compress_tree_node* -compress_tree_lookup(struct compress_tree_node** tree, uint8_t* dname, - int labs, struct compress_tree_node*** insertpt) -{ - struct compress_tree_node* p; - int m; - if(labs <= 1) - return 0; /* do not compress root node */ - if(compress_tree_search(tree, dname, labs, &p, &m, insertpt)) { - /* exact match */ - return p; - } - /* return some ancestor of p that compresses well. */ - if(m>1) { - /* www.example.com. (labs=4) matched foo.example.com.(labs=4) - * then matchcount = 3. need to go up. */ - while(p && p->labs > m) - p = p->parent; - return p; - } - return 0; -} - -/** - * Create node for domain name compression tree. - * @param dname: pointer to uncompressed dname (stored in tree). - * @param labs: number of labels in dname. - * @param offset: offset into packet for dname. - * @param region: how to allocate memory for new node. - * @return new node or 0 on malloc failure. - */ -static struct compress_tree_node* -compress_tree_newnode(uint8_t* dname, int labs, size_t offset, - struct regional* region) -{ - struct compress_tree_node* n = (struct compress_tree_node*) - regional_alloc(region, sizeof(struct compress_tree_node)); - if(!n) return 0; - n->left = 0; - n->right = 0; - n->parent = 0; - n->dname = dname; - n->labs = labs; - n->offset = offset; - return n; -} - -/** - * Store domain name and ancestors into compression tree. - * @param dname: pointer to uncompressed dname (stored in tree). - * @param labs: number of labels in dname. - * @param offset: offset into packet for dname. - * @param region: how to allocate memory for new node. - * @param closest: match from previous lookup, used to compress dname. - * may be NULL if no previous match. - * if the tree has an ancestor of dname already, this must be it. - * @param insertpt: where to insert the dname in tree. - * @return: 0 on memory error. - */ -static int -compress_tree_store(uint8_t* dname, int labs, size_t offset, - struct regional* region, struct compress_tree_node* closest, - struct compress_tree_node** insertpt) -{ - uint8_t lablen; - struct compress_tree_node* newnode; - struct compress_tree_node* prevnode = NULL; - int uplabs = labs-1; /* does not store root in tree */ - if(closest) uplabs = labs - closest->labs; - log_assert(uplabs >= 0); - /* algorithms builds up a vine of dname-labels to hang into tree */ - while(uplabs--) { - if(offset > PTR_MAX_OFFSET) { - /* insertion failed, drop vine */ - return 1; /* compression pointer no longer useful */ - } - if(!(newnode = compress_tree_newnode(dname, labs, offset, - region))) { - /* insertion failed, drop vine */ - return 0; - } - - if(prevnode) { - /* chain nodes together, last one has one label more, - * so is larger than newnode, thus goes right. */ - newnode->right = prevnode; - prevnode->parent = newnode; - } - - /* next label */ - lablen = *dname++; - dname += lablen; - offset += lablen+1; - prevnode = newnode; - labs--; - } - /* if we have a vine, hang the vine into the tree */ - if(prevnode) { - *insertpt = prevnode; - prevnode->parent = closest; - } - return 1; -} - -/** compress a domain name */ -static int -write_compressed_dname(sldns_buffer* pkt, uint8_t* dname, int labs, - struct compress_tree_node* p) -{ - /* compress it */ - int labcopy = labs - p->labs; - uint8_t lablen; - uint16_t ptr; - - if(labs == 1) { - /* write root label */ - if(sldns_buffer_remaining(pkt) < 1) - return 0; - sldns_buffer_write_u8(pkt, 0); - return 1; - } - - /* copy the first couple of labels */ - while(labcopy--) { - lablen = *dname++; - if(sldns_buffer_remaining(pkt) < (size_t)lablen+1) - return 0; - sldns_buffer_write_u8(pkt, lablen); - sldns_buffer_write(pkt, dname, lablen); - dname += lablen; - } - /* insert compression ptr */ - if(sldns_buffer_remaining(pkt) < 2) - return 0; - ptr = PTR_CREATE(p->offset); - sldns_buffer_write_u16(pkt, ptr); - return 1; -} - -/** compress owner name of RR, return RETVAL_OUTMEM RETVAL_TRUNC */ -static int -compress_owner(struct ub_packed_rrset_key* key, sldns_buffer* pkt, - struct regional* region, struct compress_tree_node** tree, - size_t owner_pos, uint16_t* owner_ptr, int owner_labs) -{ - struct compress_tree_node* p; - struct compress_tree_node** insertpt = NULL; - if(!*owner_ptr) { - /* compress first time dname */ - if((p = compress_tree_lookup(tree, key->rk.dname, - owner_labs, &insertpt))) { - if(p->labs == owner_labs) - /* avoid ptr chains, since some software is - * not capable of decoding ptr after a ptr. */ - *owner_ptr = htons(PTR_CREATE(p->offset)); - if(!write_compressed_dname(pkt, key->rk.dname, - owner_labs, p)) - return RETVAL_TRUNC; - /* check if typeclass+4 ttl + rdatalen is available */ - if(sldns_buffer_remaining(pkt) < 4+4+2) - return RETVAL_TRUNC; - } else { - /* no compress */ - if(sldns_buffer_remaining(pkt) < key->rk.dname_len+4+4+2) - return RETVAL_TRUNC; - sldns_buffer_write(pkt, key->rk.dname, - key->rk.dname_len); - if(owner_pos <= PTR_MAX_OFFSET) - *owner_ptr = htons(PTR_CREATE(owner_pos)); - } - if(!compress_tree_store(key->rk.dname, owner_labs, - owner_pos, region, p, insertpt)) - return RETVAL_OUTMEM; - } else { - /* always compress 2nd-further RRs in RRset */ - if(owner_labs == 1) { - if(sldns_buffer_remaining(pkt) < 1+4+4+2) - return RETVAL_TRUNC; - sldns_buffer_write_u8(pkt, 0); - } else { - if(sldns_buffer_remaining(pkt) < 2+4+4+2) - return RETVAL_TRUNC; - sldns_buffer_write(pkt, owner_ptr, 2); - } - } - return RETVAL_OK; -} - -/** compress any domain name to the packet, return RETVAL_* */ -static int -compress_any_dname(uint8_t* dname, sldns_buffer* pkt, int labs, - struct regional* region, struct compress_tree_node** tree) -{ - struct compress_tree_node* p; - struct compress_tree_node** insertpt = NULL; - size_t pos = sldns_buffer_position(pkt); - if((p = compress_tree_lookup(tree, dname, labs, &insertpt))) { - if(!write_compressed_dname(pkt, dname, labs, p)) - return RETVAL_TRUNC; - } else { - if(!dname_buffer_write(pkt, dname)) - return RETVAL_TRUNC; - } - if(!compress_tree_store(dname, labs, pos, region, p, insertpt)) - return RETVAL_OUTMEM; - return RETVAL_OK; -} - -/** return true if type needs domain name compression in rdata */ -static const sldns_rr_descriptor* -type_rdata_compressable(struct ub_packed_rrset_key* key) -{ - uint16_t t = ntohs(key->rk.type); - if(sldns_rr_descript(t) && - sldns_rr_descript(t)->_compress == LDNS_RR_COMPRESS) - return sldns_rr_descript(t); - return 0; -} - -/** compress domain names in rdata, return RETVAL_* */ -static int -compress_rdata(sldns_buffer* pkt, uint8_t* rdata, size_t todolen, - struct regional* region, struct compress_tree_node** tree, - const sldns_rr_descriptor* desc) -{ - int labs, r, rdf = 0; - size_t dname_len, len, pos = sldns_buffer_position(pkt); - uint8_t count = desc->_dname_count; - - sldns_buffer_skip(pkt, 2); /* rdata len fill in later */ - /* space for rdatalen checked for already */ - rdata += 2; - todolen -= 2; - while(todolen > 0 && count) { - switch(desc->_wireformat[rdf]) { - case LDNS_RDF_TYPE_DNAME: - labs = dname_count_size_labels(rdata, &dname_len); - if((r=compress_any_dname(rdata, pkt, labs, region, - tree)) != RETVAL_OK) - return r; - rdata += dname_len; - todolen -= dname_len; - count--; - len = 0; - break; - case LDNS_RDF_TYPE_STR: - len = *rdata + 1; - break; - default: - len = get_rdf_size(desc->_wireformat[rdf]); - } - if(len) { - /* copy over */ - if(sldns_buffer_remaining(pkt) < len) - return RETVAL_TRUNC; - sldns_buffer_write(pkt, rdata, len); - todolen -= len; - rdata += len; - } - rdf++; - } - /* copy remainder */ - if(todolen > 0) { - if(sldns_buffer_remaining(pkt) < todolen) - return RETVAL_TRUNC; - sldns_buffer_write(pkt, rdata, todolen); - } - - /* set rdata len */ - sldns_buffer_write_u16_at(pkt, pos, sldns_buffer_position(pkt)-pos-2); - return RETVAL_OK; -} - -/** Returns true if RR type should be included */ -static int -rrset_belongs_in_reply(sldns_pkt_section s, uint16_t rrtype, uint16_t qtype, - int dnssec) -{ - if(dnssec) - return 1; - /* skip non DNSSEC types, except if directly queried for */ - if(s == LDNS_SECTION_ANSWER) { - if(qtype == LDNS_RR_TYPE_ANY || qtype == rrtype) - return 1; - } - /* check DNSSEC-ness */ - switch(rrtype) { - case LDNS_RR_TYPE_SIG: - case LDNS_RR_TYPE_KEY: - case LDNS_RR_TYPE_NXT: - case LDNS_RR_TYPE_DS: - case LDNS_RR_TYPE_RRSIG: - case LDNS_RR_TYPE_NSEC: - case LDNS_RR_TYPE_DNSKEY: - case LDNS_RR_TYPE_NSEC3: - case LDNS_RR_TYPE_NSEC3PARAMS: - return 0; - } - return 1; -} - -/** store rrset in buffer in wireformat, return RETVAL_* */ -static int -packed_rrset_encode(struct ub_packed_rrset_key* key, sldns_buffer* pkt, - uint16_t* num_rrs, time_t timenow, struct regional* region, - int do_data, int do_sig, struct compress_tree_node** tree, - sldns_pkt_section s, uint16_t qtype, int dnssec, size_t rr_offset) -{ - size_t i, j, owner_pos; - int r, owner_labs; - uint16_t owner_ptr = 0; - struct packed_rrset_data* data = (struct packed_rrset_data*) - key->entry.data; - - /* does this RR type belong in the answer? */ - if(!rrset_belongs_in_reply(s, ntohs(key->rk.type), qtype, dnssec)) - return RETVAL_OK; - - owner_labs = dname_count_labels(key->rk.dname); - owner_pos = sldns_buffer_position(pkt); - - /* For an rrset with a fixed TTL, use the rrset's TTL as given */ - if((key->rk.flags & PACKED_RRSET_FIXEDTTL) != 0) - timenow = 0; - - if(do_data) { - const sldns_rr_descriptor* c = type_rdata_compressable(key); - for(i=0; i<data->count; i++) { - /* rrset roundrobin */ - j = (i + rr_offset) % data->count; - if((r=compress_owner(key, pkt, region, tree, - owner_pos, &owner_ptr, owner_labs)) - != RETVAL_OK) - return r; - sldns_buffer_write(pkt, &key->rk.type, 2); - sldns_buffer_write(pkt, &key->rk.rrset_class, 2); - if(data->rr_ttl[j] < timenow) - sldns_buffer_write_u32(pkt, 0); - else sldns_buffer_write_u32(pkt, - data->rr_ttl[j]-timenow); - if(c) { - if((r=compress_rdata(pkt, data->rr_data[j], - data->rr_len[j], region, tree, c)) - != RETVAL_OK) - return r; - } else { - if(sldns_buffer_remaining(pkt) < data->rr_len[j]) - return RETVAL_TRUNC; - sldns_buffer_write(pkt, data->rr_data[j], - data->rr_len[j]); - } - } - } - /* insert rrsigs */ - if(do_sig && dnssec) { - size_t total = data->count+data->rrsig_count; - for(i=data->count; i<total; i++) { - if(owner_ptr && owner_labs != 1) { - if(sldns_buffer_remaining(pkt) < - 2+4+4+data->rr_len[i]) - return RETVAL_TRUNC; - sldns_buffer_write(pkt, &owner_ptr, 2); - } else { - if((r=compress_any_dname(key->rk.dname, - pkt, owner_labs, region, tree)) - != RETVAL_OK) - return r; - if(sldns_buffer_remaining(pkt) < - 4+4+data->rr_len[i]) - return RETVAL_TRUNC; - } - sldns_buffer_write_u16(pkt, LDNS_RR_TYPE_RRSIG); - sldns_buffer_write(pkt, &key->rk.rrset_class, 2); - if(data->rr_ttl[i] < timenow) - sldns_buffer_write_u32(pkt, 0); - else sldns_buffer_write_u32(pkt, - data->rr_ttl[i]-timenow); - /* rrsig rdata cannot be compressed, perform 100+ byte - * memcopy. */ - sldns_buffer_write(pkt, data->rr_data[i], - data->rr_len[i]); - } - } - /* change rrnum only after we are sure it fits */ - if(do_data) - *num_rrs += data->count; - if(do_sig && dnssec) - *num_rrs += data->rrsig_count; - - return RETVAL_OK; -} - -/** store msg section in wireformat buffer, return RETVAL_* */ -static int -insert_section(struct reply_info* rep, size_t num_rrsets, uint16_t* num_rrs, - sldns_buffer* pkt, size_t rrsets_before, time_t timenow, - struct regional* region, struct compress_tree_node** tree, - sldns_pkt_section s, uint16_t qtype, int dnssec, size_t rr_offset) -{ - int r; - size_t i, setstart; - /* we now allow this function to be called multiple times for the - * same section, incrementally updating num_rrs. The caller is - * responsible for initializing it (which is the case in the current - * implementation). */ - - if(s != LDNS_SECTION_ADDITIONAL) { - if(s == LDNS_SECTION_ANSWER && qtype == LDNS_RR_TYPE_ANY) - dnssec = 1; /* include all types in ANY answer */ - for(i=0; i<num_rrsets; i++) { - setstart = sldns_buffer_position(pkt); - if((r=packed_rrset_encode(rep->rrsets[rrsets_before+i], - pkt, num_rrs, timenow, region, 1, 1, tree, - s, qtype, dnssec, rr_offset)) - != RETVAL_OK) { - /* Bad, but if due to size must set TC bit */ - /* trim off the rrset neatly. */ - sldns_buffer_set_position(pkt, setstart); - return r; - } - } - } else { - for(i=0; i<num_rrsets; i++) { - setstart = sldns_buffer_position(pkt); - if((r=packed_rrset_encode(rep->rrsets[rrsets_before+i], - pkt, num_rrs, timenow, region, 1, 0, tree, - s, qtype, dnssec, rr_offset)) - != RETVAL_OK) { - sldns_buffer_set_position(pkt, setstart); - return r; - } - } - if(dnssec) - for(i=0; i<num_rrsets; i++) { - setstart = sldns_buffer_position(pkt); - if((r=packed_rrset_encode(rep->rrsets[rrsets_before+i], - pkt, num_rrs, timenow, region, 0, 1, tree, - s, qtype, dnssec, rr_offset)) - != RETVAL_OK) { - sldns_buffer_set_position(pkt, setstart); - return r; - } - } - } - return RETVAL_OK; -} - -/** store query section in wireformat buffer, return RETVAL */ -static int -insert_query(struct query_info* qinfo, struct compress_tree_node** tree, - sldns_buffer* buffer, struct regional* region) -{ - uint8_t* qname = qinfo->local_alias ? - qinfo->local_alias->rrset->rk.dname : qinfo->qname; - size_t qname_len = qinfo->local_alias ? - qinfo->local_alias->rrset->rk.dname_len : qinfo->qname_len; - if(sldns_buffer_remaining(buffer) < - qinfo->qname_len+sizeof(uint16_t)*2) - return RETVAL_TRUNC; /* buffer too small */ - /* the query is the first name inserted into the tree */ - if(!compress_tree_store(qname, dname_count_labels(qname), - sldns_buffer_position(buffer), region, NULL, tree)) - return RETVAL_OUTMEM; - if(sldns_buffer_current(buffer) == qname) - sldns_buffer_skip(buffer, (ssize_t)qname_len); - else sldns_buffer_write(buffer, qname, qname_len); - sldns_buffer_write_u16(buffer, qinfo->qtype); - sldns_buffer_write_u16(buffer, qinfo->qclass); - return RETVAL_OK; -} - -static int -positive_answer(struct reply_info* rep, uint16_t qtype) { - size_t i; - if (FLAGS_GET_RCODE(rep->flags) != LDNS_RCODE_NOERROR) - return 0; - - for(i=0;i<rep->an_numrrsets; i++) { - if(ntohs(rep->rrsets[i]->rk.type) == qtype) { - /* in case it is a wildcard with DNSSEC, there will - * be NSEC/NSEC3 records in the authority section - * that we cannot remove */ - for(i=rep->an_numrrsets; i<rep->an_numrrsets+ - rep->ns_numrrsets; i++) { - if(ntohs(rep->rrsets[i]->rk.type) == - LDNS_RR_TYPE_NSEC || - ntohs(rep->rrsets[i]->rk.type) == - LDNS_RR_TYPE_NSEC3) - return 0; - } - return 1; - } - } - return 0; -} - -int -reply_info_encode(struct query_info* qinfo, struct reply_info* rep, - uint16_t id, uint16_t flags, sldns_buffer* buffer, time_t timenow, - struct regional* region, uint16_t udpsize, int dnssec) -{ - uint16_t ancount=0, nscount=0, arcount=0; - struct compress_tree_node* tree = 0; - int r; - size_t rr_offset; - - sldns_buffer_clear(buffer); - if(udpsize < sldns_buffer_limit(buffer)) - sldns_buffer_set_limit(buffer, udpsize); - if(sldns_buffer_remaining(buffer) < LDNS_HEADER_SIZE) - return 0; - - sldns_buffer_write(buffer, &id, sizeof(uint16_t)); - sldns_buffer_write_u16(buffer, flags); - sldns_buffer_write_u16(buffer, rep->qdcount); - /* set an, ns, ar counts to zero in case of small packets */ - sldns_buffer_write(buffer, "\000\000\000\000\000\000", 6); - - /* insert query section */ - if(rep->qdcount) { - if((r=insert_query(qinfo, &tree, buffer, region)) != - RETVAL_OK) { - if(r == RETVAL_TRUNC) { - /* create truncated message */ - sldns_buffer_write_u16_at(buffer, 4, 0); - LDNS_TC_SET(sldns_buffer_begin(buffer)); - sldns_buffer_flip(buffer); - return 1; - } - return 0; - } - } - /* roundrobin offset. using query id for random number. With ntohs - * for different roundrobins for sequential id client senders. */ - rr_offset = RRSET_ROUNDROBIN?ntohs(id):0; - - /* "prepend" any local alias records in the answer section if this - * response is supposed to be authoritative. Currently it should - * be a single CNAME record (sanity-checked in worker_handle_request()) - * but it can be extended if and when we support more variations of - * aliases. */ - if(qinfo->local_alias && (flags & BIT_AA)) { - struct reply_info arep; - time_t timezero = 0; /* to use the 'authoritative' TTL */ - memset(&arep, 0, sizeof(arep)); - arep.flags = rep->flags; - arep.an_numrrsets = 1; - arep.rrset_count = 1; - arep.rrsets = &qinfo->local_alias->rrset; - if((r=insert_section(&arep, 1, &ancount, buffer, 0, - timezero, region, &tree, LDNS_SECTION_ANSWER, - qinfo->qtype, dnssec, rr_offset)) != RETVAL_OK) { - if(r == RETVAL_TRUNC) { - /* create truncated message */ - sldns_buffer_write_u16_at(buffer, 6, ancount); - LDNS_TC_SET(sldns_buffer_begin(buffer)); - sldns_buffer_flip(buffer); - return 1; - } - return 0; - } - } - - /* insert answer section */ - if((r=insert_section(rep, rep->an_numrrsets, &ancount, buffer, - 0, timenow, region, &tree, LDNS_SECTION_ANSWER, qinfo->qtype, - dnssec, rr_offset)) != RETVAL_OK) { - if(r == RETVAL_TRUNC) { - /* create truncated message */ - sldns_buffer_write_u16_at(buffer, 6, ancount); - LDNS_TC_SET(sldns_buffer_begin(buffer)); - sldns_buffer_flip(buffer); - return 1; - } - return 0; - } - sldns_buffer_write_u16_at(buffer, 6, ancount); - - /* if response is positive answer, auth/add sections are not required */ - if( ! (MINIMAL_RESPONSES && positive_answer(rep, qinfo->qtype)) ) { - /* insert auth section */ - if((r=insert_section(rep, rep->ns_numrrsets, &nscount, buffer, - rep->an_numrrsets, timenow, region, &tree, - LDNS_SECTION_AUTHORITY, qinfo->qtype, - dnssec, rr_offset)) != RETVAL_OK) { - if(r == RETVAL_TRUNC) { - /* create truncated message */ - sldns_buffer_write_u16_at(buffer, 8, nscount); - LDNS_TC_SET(sldns_buffer_begin(buffer)); - sldns_buffer_flip(buffer); - return 1; - } - return 0; - } - sldns_buffer_write_u16_at(buffer, 8, nscount); - - /* insert add section */ - if((r=insert_section(rep, rep->ar_numrrsets, &arcount, buffer, - rep->an_numrrsets + rep->ns_numrrsets, timenow, region, - &tree, LDNS_SECTION_ADDITIONAL, qinfo->qtype, - dnssec, rr_offset)) != RETVAL_OK) { - if(r == RETVAL_TRUNC) { - /* no need to set TC bit, this is the additional */ - sldns_buffer_write_u16_at(buffer, 10, arcount); - sldns_buffer_flip(buffer); - return 1; - } - return 0; - } - sldns_buffer_write_u16_at(buffer, 10, arcount); - } - sldns_buffer_flip(buffer); - return 1; -} - -uint16_t -calc_edns_field_size(struct edns_data* edns) -{ - size_t rdatalen = 0; - struct edns_option* opt; - if(!edns || !edns->edns_present) - return 0; - for(opt = edns->opt_list; opt; opt = opt->next) { - rdatalen += 4 + opt->opt_len; - } - /* domain root '.' + type + class + ttl + rdatalen */ - return 1 + 2 + 2 + 4 + 2 + rdatalen; -} - -void -attach_edns_record(sldns_buffer* pkt, struct edns_data* edns) -{ - size_t len; - size_t rdatapos; - struct edns_option* opt; - if(!edns || !edns->edns_present) - return; - /* inc additional count */ - sldns_buffer_write_u16_at(pkt, 10, - sldns_buffer_read_u16_at(pkt, 10) + 1); - len = sldns_buffer_limit(pkt); - sldns_buffer_clear(pkt); - sldns_buffer_set_position(pkt, len); - /* write EDNS record */ - sldns_buffer_write_u8(pkt, 0); /* '.' label */ - sldns_buffer_write_u16(pkt, LDNS_RR_TYPE_OPT); /* type */ - sldns_buffer_write_u16(pkt, edns->udp_size); /* class */ - sldns_buffer_write_u8(pkt, edns->ext_rcode); /* ttl */ - sldns_buffer_write_u8(pkt, edns->edns_version); - sldns_buffer_write_u16(pkt, edns->bits); - rdatapos = sldns_buffer_position(pkt); - sldns_buffer_write_u16(pkt, 0); /* rdatalen */ - /* write rdata */ - for(opt=edns->opt_list; opt; opt=opt->next) { - sldns_buffer_write_u16(pkt, opt->opt_code); - sldns_buffer_write_u16(pkt, opt->opt_len); - if(opt->opt_len != 0) - sldns_buffer_write(pkt, opt->opt_data, opt->opt_len); - } - if(edns->opt_list) - sldns_buffer_write_u16_at(pkt, rdatapos, - sldns_buffer_position(pkt)-rdatapos-2); - sldns_buffer_flip(pkt); -} - -int -reply_info_answer_encode(struct query_info* qinf, struct reply_info* rep, - uint16_t id, uint16_t qflags, sldns_buffer* pkt, time_t timenow, - int cached, struct regional* region, uint16_t udpsize, - struct edns_data* edns, int dnssec, int secure) -{ - uint16_t flags; - int attach_edns = 1; - - if(!cached || rep->authoritative) { - /* original flags, copy RD and CD bits from query. */ - flags = rep->flags | (qflags & (BIT_RD|BIT_CD)); - } else { - /* remove AA bit, copy RD and CD bits from query. */ - flags = (rep->flags & ~BIT_AA) | (qflags & (BIT_RD|BIT_CD)); - } - if(secure && (dnssec || (qflags&BIT_AD))) - flags |= BIT_AD; - /* restore AA bit if we have a local alias and the response can be - * authoritative. Also clear AD bit if set as the local data is the - * primary answer. */ - if(qinf->local_alias && - (FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NOERROR || - FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NXDOMAIN)) { - flags |= BIT_AA; - flags &= ~BIT_AD; - } - log_assert(flags & BIT_QR); /* QR bit must be on in our replies */ - if(udpsize < LDNS_HEADER_SIZE) - return 0; - if(udpsize < LDNS_HEADER_SIZE + calc_edns_field_size(edns)) { - /* packet too small to contain edns, omit it. */ - attach_edns = 0; - } else { - /* reserve space for edns record */ - udpsize -= calc_edns_field_size(edns); - } - - if(!reply_info_encode(qinf, rep, id, flags, pkt, timenow, region, - udpsize, dnssec)) { - log_err("reply encode: out of memory"); - return 0; - } - if(attach_edns) - attach_edns_record(pkt, edns); - return 1; -} - -void -qinfo_query_encode(sldns_buffer* pkt, struct query_info* qinfo) -{ - uint16_t flags = 0; /* QUERY, NOERROR */ - const uint8_t* qname = qinfo->local_alias ? - qinfo->local_alias->rrset->rk.dname : qinfo->qname; - size_t qname_len = qinfo->local_alias ? - qinfo->local_alias->rrset->rk.dname_len : qinfo->qname_len; - sldns_buffer_clear(pkt); - log_assert(sldns_buffer_remaining(pkt) >= 12+255+4/*max query*/); - sldns_buffer_skip(pkt, 2); /* id done later */ - sldns_buffer_write_u16(pkt, flags); - sldns_buffer_write_u16(pkt, 1); /* query count */ - sldns_buffer_write(pkt, "\000\000\000\000\000\000", 6); /* counts */ - sldns_buffer_write(pkt, qname, qname_len); - sldns_buffer_write_u16(pkt, qinfo->qtype); - sldns_buffer_write_u16(pkt, qinfo->qclass); - sldns_buffer_flip(pkt); -} - -void -error_encode(sldns_buffer* buf, int r, struct query_info* qinfo, - uint16_t qid, uint16_t qflags, struct edns_data* edns) -{ - uint16_t flags; - - sldns_buffer_clear(buf); - sldns_buffer_write(buf, &qid, sizeof(uint16_t)); - flags = (uint16_t)(BIT_QR | BIT_RA | r); /* QR and retcode*/ - flags |= (qflags & (BIT_RD|BIT_CD)); /* copy RD and CD bit */ - sldns_buffer_write_u16(buf, flags); - if(qinfo) flags = 1; - else flags = 0; - sldns_buffer_write_u16(buf, flags); - flags = 0; - sldns_buffer_write(buf, &flags, sizeof(uint16_t)); - sldns_buffer_write(buf, &flags, sizeof(uint16_t)); - sldns_buffer_write(buf, &flags, sizeof(uint16_t)); - if(qinfo) { - const uint8_t* qname = qinfo->local_alias ? - qinfo->local_alias->rrset->rk.dname : qinfo->qname; - size_t qname_len = qinfo->local_alias ? - qinfo->local_alias->rrset->rk.dname_len : - qinfo->qname_len; - if(sldns_buffer_current(buf) == qname) - sldns_buffer_skip(buf, (ssize_t)qname_len); - else sldns_buffer_write(buf, qname, qname_len); - sldns_buffer_write_u16(buf, qinfo->qtype); - sldns_buffer_write_u16(buf, qinfo->qclass); - } - sldns_buffer_flip(buf); - if(edns) { - struct edns_data es = *edns; - es.edns_version = EDNS_ADVERTISED_VERSION; - es.udp_size = EDNS_ADVERTISED_SIZE; - es.ext_rcode = 0; - es.bits &= EDNS_DO; - if(sldns_buffer_limit(buf) + calc_edns_field_size(&es) > - edns->udp_size) - return; - attach_edns_record(buf, &es); - } -} |