msgparse.c revision 238106
1238106Sdes/* 2238106Sdes * util/data/msgparse.c - parse wireformat DNS messages. 3238106Sdes * 4238106Sdes * Copyright (c) 2007, NLnet Labs. All rights reserved. 5238106Sdes * 6238106Sdes * This software is open source. 7238106Sdes * 8238106Sdes * Redistribution and use in source and binary forms, with or without 9238106Sdes * modification, are permitted provided that the following conditions 10238106Sdes * are met: 11238106Sdes * 12238106Sdes * Redistributions of source code must retain the above copyright notice, 13238106Sdes * this list of conditions and the following disclaimer. 14238106Sdes * 15238106Sdes * Redistributions in binary form must reproduce the above copyright notice, 16238106Sdes * this list of conditions and the following disclaimer in the documentation 17238106Sdes * and/or other materials provided with the distribution. 18238106Sdes * 19238106Sdes * Neither the name of the NLNET LABS nor the names of its contributors may 20238106Sdes * be used to endorse or promote products derived from this software without 21238106Sdes * specific prior written permission. 22238106Sdes * 23238106Sdes * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24238106Sdes * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 25238106Sdes * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26238106Sdes * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE 27238106Sdes * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28238106Sdes * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29238106Sdes * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30238106Sdes * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31238106Sdes * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32238106Sdes * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33238106Sdes * POSSIBILITY OF SUCH DAMAGE. 34238106Sdes */ 35238106Sdes/** 36238106Sdes * \file 37238106Sdes * Routines for message parsing a packet buffer to a descriptive structure. 38238106Sdes */ 39238106Sdes#include "config.h" 40238106Sdes#include <ldns/ldns.h> 41238106Sdes#include "util/data/msgparse.h" 42238106Sdes#include "util/net_help.h" 43238106Sdes#include "util/data/dname.h" 44238106Sdes#include "util/data/packed_rrset.h" 45238106Sdes#include "util/storage/lookup3.h" 46238106Sdes#include "util/regional.h" 47238106Sdes 48238106Sdes/** smart comparison of (compressed, valid) dnames from packet */ 49238106Sdesstatic int 50238106Sdessmart_compare(ldns_buffer* pkt, uint8_t* dnow, 51238106Sdes uint8_t* dprfirst, uint8_t* dprlast) 52238106Sdes{ 53238106Sdes if(LABEL_IS_PTR(*dnow)) { 54238106Sdes /* ptr points to a previous dname */ 55238106Sdes uint8_t* p = ldns_buffer_at(pkt, PTR_OFFSET(dnow[0], dnow[1])); 56238106Sdes if( p == dprfirst || p == dprlast ) 57238106Sdes return 0; 58238106Sdes /* prev dname is also a ptr, both ptrs are the same. */ 59238106Sdes if(LABEL_IS_PTR(*dprlast) && 60238106Sdes dprlast[0] == dnow[0] && dprlast[1] == dnow[1]) 61238106Sdes return 0; 62238106Sdes } 63238106Sdes return dname_pkt_compare(pkt, dnow, dprlast); 64238106Sdes} 65238106Sdes 66238106Sdes/** 67238106Sdes * Allocate new rrset in region, fill with data. 68238106Sdes */ 69238106Sdesstatic struct rrset_parse* 70238106Sdesnew_rrset(struct msg_parse* msg, uint8_t* dname, size_t dnamelen, 71238106Sdes uint16_t type, uint16_t dclass, hashvalue_t hash, 72238106Sdes uint32_t rrset_flags, ldns_pkt_section section, 73238106Sdes struct regional* region) 74238106Sdes{ 75238106Sdes struct rrset_parse* p = regional_alloc(region, sizeof(*p)); 76238106Sdes if(!p) return NULL; 77238106Sdes p->rrset_bucket_next = msg->hashtable[hash & (PARSE_TABLE_SIZE-1)]; 78238106Sdes msg->hashtable[hash & (PARSE_TABLE_SIZE-1)] = p; 79238106Sdes p->rrset_all_next = 0; 80238106Sdes if(msg->rrset_last) 81238106Sdes msg->rrset_last->rrset_all_next = p; 82238106Sdes else msg->rrset_first = p; 83238106Sdes msg->rrset_last = p; 84238106Sdes p->hash = hash; 85238106Sdes p->section = section; 86238106Sdes p->dname = dname; 87238106Sdes p->dname_len = dnamelen; 88238106Sdes p->type = type; 89238106Sdes p->rrset_class = dclass; 90238106Sdes p->flags = rrset_flags; 91238106Sdes p->rr_count = 0; 92238106Sdes p->size = 0; 93238106Sdes p->rr_first = 0; 94238106Sdes p->rr_last = 0; 95238106Sdes p->rrsig_count = 0; 96238106Sdes p->rrsig_first = 0; 97238106Sdes p->rrsig_last = 0; 98238106Sdes return p; 99238106Sdes} 100238106Sdes 101238106Sdes/** See if next rrset is nsec at zone apex */ 102238106Sdesstatic int 103238106Sdesnsec_at_apex(ldns_buffer* pkt) 104238106Sdes{ 105238106Sdes /* we are at ttl position in packet. */ 106238106Sdes size_t pos = ldns_buffer_position(pkt); 107238106Sdes uint16_t rdatalen; 108238106Sdes if(ldns_buffer_remaining(pkt) < 7) /* ttl+len+root */ 109238106Sdes return 0; /* eek! */ 110238106Sdes ldns_buffer_skip(pkt, 4); /* ttl */; 111238106Sdes rdatalen = ldns_buffer_read_u16(pkt); 112238106Sdes if(ldns_buffer_remaining(pkt) < rdatalen) { 113238106Sdes ldns_buffer_set_position(pkt, pos); 114238106Sdes return 0; /* parse error happens later */ 115238106Sdes } 116238106Sdes /* must validate the nsec next domain name format */ 117238106Sdes if(pkt_dname_len(pkt) == 0) { 118238106Sdes ldns_buffer_set_position(pkt, pos); 119238106Sdes return 0; /* parse error */ 120238106Sdes } 121238106Sdes 122238106Sdes /* see if SOA bit is set. */ 123238106Sdes if(ldns_buffer_position(pkt) < pos+4+rdatalen) { 124238106Sdes /* nsec type bitmap contains items */ 125238106Sdes uint8_t win, blen, bits; 126238106Sdes /* need: windownum, bitmap len, firstbyte */ 127238106Sdes if(ldns_buffer_position(pkt)+3 > pos+4+rdatalen) { 128238106Sdes ldns_buffer_set_position(pkt, pos); 129238106Sdes return 0; /* malformed nsec */ 130238106Sdes } 131238106Sdes win = ldns_buffer_read_u8(pkt); 132238106Sdes blen = ldns_buffer_read_u8(pkt); 133238106Sdes bits = ldns_buffer_read_u8(pkt); 134238106Sdes /* 0window always first window. bitlen >=1 or parse 135238106Sdes error really. bit 0x2 is SOA. */ 136238106Sdes if(win == 0 && blen >= 1 && (bits & 0x02)) { 137238106Sdes ldns_buffer_set_position(pkt, pos); 138238106Sdes return 1; 139238106Sdes } 140238106Sdes } 141238106Sdes 142238106Sdes ldns_buffer_set_position(pkt, pos); 143238106Sdes return 0; 144238106Sdes} 145238106Sdes 146238106Sdes/** Calculate rrset flags */ 147238106Sdesstatic uint32_t 148238106Sdespkt_rrset_flags(ldns_buffer* pkt, uint16_t type, ldns_pkt_section sec) 149238106Sdes{ 150238106Sdes uint32_t f = 0; 151238106Sdes if(type == LDNS_RR_TYPE_NSEC && nsec_at_apex(pkt)) { 152238106Sdes f |= PACKED_RRSET_NSEC_AT_APEX; 153238106Sdes } else if(type == LDNS_RR_TYPE_SOA && sec == LDNS_SECTION_AUTHORITY) { 154238106Sdes f |= PACKED_RRSET_SOA_NEG; 155238106Sdes } 156238106Sdes return f; 157238106Sdes} 158238106Sdes 159238106Sdeshashvalue_t 160238106Sdespkt_hash_rrset(ldns_buffer* pkt, uint8_t* dname, uint16_t type, 161238106Sdes uint16_t dclass, uint32_t rrset_flags) 162238106Sdes{ 163238106Sdes /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ 164238106Sdes /* this routine handles compressed names */ 165238106Sdes hashvalue_t h = 0xab; 166238106Sdes h = dname_pkt_hash(pkt, dname, h); 167238106Sdes h = hashlittle(&type, sizeof(type), h); /* host order */ 168238106Sdes h = hashlittle(&dclass, sizeof(dclass), h); /* netw order */ 169238106Sdes h = hashlittle(&rrset_flags, sizeof(uint32_t), h); 170238106Sdes return h; 171238106Sdes} 172238106Sdes 173238106Sdes/** create partial dname hash for rrset hash */ 174238106Sdesstatic hashvalue_t 175238106Sdespkt_hash_rrset_first(ldns_buffer* pkt, uint8_t* dname) 176238106Sdes{ 177238106Sdes /* works together with pkt_hash_rrset_rest */ 178238106Sdes /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ 179238106Sdes /* this routine handles compressed names */ 180238106Sdes hashvalue_t h = 0xab; 181238106Sdes h = dname_pkt_hash(pkt, dname, h); 182238106Sdes return h; 183238106Sdes} 184238106Sdes 185238106Sdes/** create a rrset hash from a partial dname hash */ 186238106Sdesstatic hashvalue_t 187238106Sdespkt_hash_rrset_rest(hashvalue_t dname_h, uint16_t type, uint16_t dclass, 188238106Sdes uint32_t rrset_flags) 189238106Sdes{ 190238106Sdes /* works together with pkt_hash_rrset_first */ 191238106Sdes /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ 192238106Sdes hashvalue_t h; 193238106Sdes h = hashlittle(&type, sizeof(type), dname_h); /* host order */ 194238106Sdes h = hashlittle(&dclass, sizeof(dclass), h); /* netw order */ 195238106Sdes h = hashlittle(&rrset_flags, sizeof(uint32_t), h); 196238106Sdes return h; 197238106Sdes} 198238106Sdes 199238106Sdes/** compare rrset_parse with data */ 200238106Sdesstatic int 201238106Sdesrrset_parse_equals(struct rrset_parse* p, ldns_buffer* pkt, hashvalue_t h, 202238106Sdes uint32_t rrset_flags, uint8_t* dname, size_t dnamelen, 203238106Sdes uint16_t type, uint16_t dclass) 204238106Sdes{ 205238106Sdes if(p->hash == h && p->dname_len == dnamelen && p->type == type && 206238106Sdes p->rrset_class == dclass && p->flags == rrset_flags && 207238106Sdes dname_pkt_compare(pkt, dname, p->dname) == 0) 208238106Sdes return 1; 209238106Sdes return 0; 210238106Sdes} 211238106Sdes 212238106Sdes 213238106Sdesstruct rrset_parse* 214238106Sdesmsgparse_hashtable_lookup(struct msg_parse* msg, ldns_buffer* pkt, 215238106Sdes hashvalue_t h, uint32_t rrset_flags, uint8_t* dname, size_t dnamelen, 216238106Sdes uint16_t type, uint16_t dclass) 217238106Sdes{ 218238106Sdes struct rrset_parse* p = msg->hashtable[h & (PARSE_TABLE_SIZE-1)]; 219238106Sdes while(p) { 220238106Sdes if(rrset_parse_equals(p, pkt, h, rrset_flags, dname, dnamelen, 221238106Sdes type, dclass)) 222238106Sdes return p; 223238106Sdes p = p->rrset_bucket_next; 224238106Sdes } 225238106Sdes return NULL; 226238106Sdes} 227238106Sdes 228238106Sdes/** return type networkformat that rrsig in packet covers */ 229238106Sdesstatic int 230238106Sdespkt_rrsig_covered(ldns_buffer* pkt, uint8_t* here, uint16_t* type) 231238106Sdes{ 232238106Sdes size_t pos = ldns_buffer_position(pkt); 233238106Sdes ldns_buffer_set_position(pkt, (size_t)(here-ldns_buffer_begin(pkt))); 234238106Sdes /* ttl + len + size of small rrsig(rootlabel, no signature) */ 235238106Sdes if(ldns_buffer_remaining(pkt) < 4+2+19) 236238106Sdes return 0; 237238106Sdes ldns_buffer_skip(pkt, 4); /* ttl */ 238238106Sdes if(ldns_buffer_read_u16(pkt) < 19) /* too short */ { 239238106Sdes ldns_buffer_set_position(pkt, pos); 240238106Sdes return 0; 241238106Sdes } 242238106Sdes *type = ldns_buffer_read_u16(pkt); 243238106Sdes ldns_buffer_set_position(pkt, pos); 244238106Sdes return 1; 245238106Sdes} 246238106Sdes 247238106Sdes/** true if covered type equals prevtype */ 248238106Sdesstatic int 249238106Sdespkt_rrsig_covered_equals(ldns_buffer* pkt, uint8_t* here, uint16_t type) 250238106Sdes{ 251238106Sdes uint16_t t; 252238106Sdes if(pkt_rrsig_covered(pkt, here, &t) && t == type) 253238106Sdes return 1; 254238106Sdes return 0; 255238106Sdes} 256238106Sdes 257238106Sdesvoid 258238106Sdesmsgparse_bucket_remove(struct msg_parse* msg, struct rrset_parse* rrset) 259238106Sdes{ 260238106Sdes struct rrset_parse** p; 261238106Sdes p = &msg->hashtable[ rrset->hash & (PARSE_TABLE_SIZE-1) ]; 262238106Sdes while(*p) { 263238106Sdes if(*p == rrset) { 264238106Sdes *p = rrset->rrset_bucket_next; 265238106Sdes return; 266238106Sdes } 267238106Sdes p = &( (*p)->rrset_bucket_next ); 268238106Sdes } 269238106Sdes} 270238106Sdes 271238106Sdes/** change section of rrset from previous to current section */ 272238106Sdesstatic void 273238106Sdeschange_section(struct msg_parse* msg, struct rrset_parse* rrset, 274238106Sdes ldns_pkt_section section) 275238106Sdes{ 276238106Sdes struct rrset_parse *p, *prev; 277238106Sdes /* remove from list */ 278238106Sdes if(section == rrset->section) 279238106Sdes return; 280238106Sdes p = msg->rrset_first; 281238106Sdes prev = 0; 282238106Sdes while(p) { 283238106Sdes if(p == rrset) { 284238106Sdes if(prev) prev->rrset_all_next = p->rrset_all_next; 285238106Sdes else msg->rrset_first = p->rrset_all_next; 286238106Sdes if(msg->rrset_last == rrset) 287238106Sdes msg->rrset_last = prev; 288238106Sdes break; 289238106Sdes } 290238106Sdes prev = p; 291238106Sdes p = p->rrset_all_next; 292238106Sdes } 293238106Sdes /* remove from count */ 294238106Sdes switch(rrset->section) { 295238106Sdes case LDNS_SECTION_ANSWER: msg->an_rrsets--; break; 296238106Sdes case LDNS_SECTION_AUTHORITY: msg->ns_rrsets--; break; 297238106Sdes case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets--; break; 298238106Sdes default: log_assert(0); 299238106Sdes } 300238106Sdes /* insert at end of list */ 301238106Sdes rrset->rrset_all_next = 0; 302238106Sdes if(msg->rrset_last) 303238106Sdes msg->rrset_last->rrset_all_next = rrset; 304238106Sdes else msg->rrset_first = rrset; 305238106Sdes msg->rrset_last = rrset; 306238106Sdes /* up count of new section */ 307238106Sdes switch(section) { 308238106Sdes case LDNS_SECTION_AUTHORITY: msg->ns_rrsets++; break; 309238106Sdes case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets++; break; 310238106Sdes default: log_assert(0); 311238106Sdes } 312238106Sdes rrset->section = section; 313238106Sdes} 314238106Sdes 315238106Sdes/** see if rrset of type RRSIG contains sig over given type */ 316238106Sdesstatic int 317238106Sdesrrset_has_sigover(ldns_buffer* pkt, struct rrset_parse* rrset, uint16_t type, 318238106Sdes int* hasother) 319238106Sdes{ 320238106Sdes int res = 0; 321238106Sdes struct rr_parse* rr = rrset->rr_first; 322238106Sdes log_assert( rrset->type == LDNS_RR_TYPE_RRSIG ); 323238106Sdes while(rr) { 324238106Sdes if(pkt_rrsig_covered_equals(pkt, rr->ttl_data, type)) 325238106Sdes res = 1; 326238106Sdes else *hasother = 1; 327238106Sdes rr = rr->next; 328238106Sdes } 329238106Sdes return res; 330238106Sdes} 331238106Sdes 332238106Sdes/** move rrsigs from sigset to dataset */ 333238106Sdesstatic int 334238106Sdesmoveover_rrsigs(ldns_buffer* pkt, struct regional* region, 335238106Sdes struct rrset_parse* sigset, struct rrset_parse* dataset, int duplicate) 336238106Sdes{ 337238106Sdes struct rr_parse* sig = sigset->rr_first; 338238106Sdes struct rr_parse* prev = NULL; 339238106Sdes struct rr_parse* insert; 340238106Sdes struct rr_parse* nextsig; 341238106Sdes while(sig) { 342238106Sdes nextsig = sig->next; 343238106Sdes if(pkt_rrsig_covered_equals(pkt, sig->ttl_data, 344238106Sdes dataset->type)) { 345238106Sdes if(duplicate) { 346238106Sdes /* new */ 347238106Sdes insert = (struct rr_parse*)regional_alloc( 348238106Sdes region, sizeof(struct rr_parse)); 349238106Sdes if(!insert) return 0; 350238106Sdes insert->outside_packet = 0; 351238106Sdes insert->ttl_data = sig->ttl_data; 352238106Sdes insert->size = sig->size; 353238106Sdes /* prev not used */ 354238106Sdes } else { 355238106Sdes /* remove from sigset */ 356238106Sdes if(prev) prev->next = sig->next; 357238106Sdes else sigset->rr_first = sig->next; 358238106Sdes if(sigset->rr_last == sig) 359238106Sdes sigset->rr_last = prev; 360238106Sdes sigset->rr_count--; 361238106Sdes sigset->size -= sig->size; 362238106Sdes insert = sig; 363238106Sdes /* prev not changed */ 364238106Sdes } 365238106Sdes /* add to dataset */ 366238106Sdes dataset->rrsig_count++; 367238106Sdes insert->next = 0; 368238106Sdes if(dataset->rrsig_last) 369238106Sdes dataset->rrsig_last->next = insert; 370238106Sdes else dataset->rrsig_first = insert; 371238106Sdes dataset->rrsig_last = insert; 372238106Sdes dataset->size += insert->size; 373238106Sdes } else { 374238106Sdes prev = sig; 375238106Sdes } 376238106Sdes sig = nextsig; 377238106Sdes } 378238106Sdes return 1; 379238106Sdes} 380238106Sdes 381238106Sdes/** change an rrsig rrset for use as data rrset */ 382238106Sdesstatic struct rrset_parse* 383238106Sdeschange_rrsig_rrset(struct rrset_parse* sigset, struct msg_parse* msg, 384238106Sdes ldns_buffer* pkt, uint16_t datatype, uint32_t rrset_flags, 385238106Sdes int hasother, ldns_pkt_section section, struct regional* region) 386238106Sdes{ 387238106Sdes struct rrset_parse* dataset = sigset; 388238106Sdes hashvalue_t hash = pkt_hash_rrset(pkt, sigset->dname, datatype, 389238106Sdes sigset->rrset_class, rrset_flags); 390238106Sdes log_assert( sigset->type == LDNS_RR_TYPE_RRSIG ); 391238106Sdes log_assert( datatype != LDNS_RR_TYPE_RRSIG ); 392238106Sdes if(hasother) { 393238106Sdes /* need to make new rrset to hold data type */ 394238106Sdes dataset = new_rrset(msg, sigset->dname, sigset->dname_len, 395238106Sdes datatype, sigset->rrset_class, hash, rrset_flags, 396238106Sdes section, region); 397238106Sdes if(!dataset) 398238106Sdes return NULL; 399238106Sdes switch(section) { 400238106Sdes case LDNS_SECTION_ANSWER: msg->an_rrsets++; break; 401238106Sdes case LDNS_SECTION_AUTHORITY: msg->ns_rrsets++; break; 402238106Sdes case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets++; break; 403238106Sdes default: log_assert(0); 404238106Sdes } 405238106Sdes if(!moveover_rrsigs(pkt, region, sigset, dataset, 406238106Sdes msg->qtype == LDNS_RR_TYPE_RRSIG || 407238106Sdes (msg->qtype == LDNS_RR_TYPE_ANY && 408238106Sdes section != LDNS_SECTION_ANSWER) )) 409238106Sdes return NULL; 410238106Sdes return dataset; 411238106Sdes } 412238106Sdes /* changeover the type of the rrset to data set */ 413238106Sdes msgparse_bucket_remove(msg, dataset); 414238106Sdes /* insert into new hash bucket */ 415238106Sdes dataset->rrset_bucket_next = msg->hashtable[hash&(PARSE_TABLE_SIZE-1)]; 416238106Sdes msg->hashtable[hash&(PARSE_TABLE_SIZE-1)] = dataset; 417238106Sdes dataset->hash = hash; 418238106Sdes /* use section of data item for result */ 419238106Sdes change_section(msg, dataset, section); 420238106Sdes dataset->type = datatype; 421238106Sdes dataset->flags = rrset_flags; 422238106Sdes dataset->rrsig_count += dataset->rr_count; 423238106Sdes dataset->rr_count = 0; 424238106Sdes /* move sigs to end of siglist */ 425238106Sdes if(dataset->rrsig_last) 426238106Sdes dataset->rrsig_last->next = dataset->rr_first; 427238106Sdes else dataset->rrsig_first = dataset->rr_first; 428238106Sdes dataset->rrsig_last = dataset->rr_last; 429238106Sdes dataset->rr_first = 0; 430238106Sdes dataset->rr_last = 0; 431238106Sdes return dataset; 432238106Sdes} 433238106Sdes 434238106Sdes/** Find rrset. If equal to previous it is fast. hash if not so. 435238106Sdes * @param msg: the message with hash table. 436238106Sdes * @param pkt: the packet in wireformat (needed for compression ptrs). 437238106Sdes * @param dname: pointer to start of dname (compressed) in packet. 438238106Sdes * @param dnamelen: uncompressed wirefmt length of dname. 439238106Sdes * @param type: type of current rr. 440238106Sdes * @param dclass: class of current rr. 441238106Sdes * @param hash: hash value is returned if the rrset could not be found. 442238106Sdes * @param rrset_flags: is returned if the rrset could not be found. 443238106Sdes * @param prev_dname_first: dname of last seen RR. First seen dname. 444238106Sdes * @param prev_dname_last: dname of last seen RR. Last seen dname. 445238106Sdes * @param prev_dnamelen: dname len of last seen RR. 446238106Sdes * @param prev_type: type of last seen RR. 447238106Sdes * @param prev_dclass: class of last seen RR. 448238106Sdes * @param rrset_prev: last seen RRset. 449238106Sdes * @param section: the current section in the packet. 450238106Sdes * @param region: used to allocate temporary parsing data. 451238106Sdes * @return 0 on out of memory. 452238106Sdes */ 453238106Sdesstatic int 454238106Sdesfind_rrset(struct msg_parse* msg, ldns_buffer* pkt, uint8_t* dname, 455238106Sdes size_t dnamelen, uint16_t type, uint16_t dclass, hashvalue_t* hash, 456238106Sdes uint32_t* rrset_flags, 457238106Sdes uint8_t** prev_dname_first, uint8_t** prev_dname_last, 458238106Sdes size_t* prev_dnamelen, uint16_t* prev_type, 459238106Sdes uint16_t* prev_dclass, struct rrset_parse** rrset_prev, 460238106Sdes ldns_pkt_section section, struct regional* region) 461238106Sdes{ 462238106Sdes hashvalue_t dname_h = pkt_hash_rrset_first(pkt, dname); 463238106Sdes uint16_t covtype; 464238106Sdes if(*rrset_prev) { 465238106Sdes /* check if equal to previous item */ 466238106Sdes if(type == *prev_type && dclass == *prev_dclass && 467238106Sdes dnamelen == *prev_dnamelen && 468238106Sdes smart_compare(pkt, dname, *prev_dname_first, 469238106Sdes *prev_dname_last) == 0 && 470238106Sdes type != LDNS_RR_TYPE_RRSIG) { 471238106Sdes /* same as previous */ 472238106Sdes *prev_dname_last = dname; 473238106Sdes return 1; 474238106Sdes } 475238106Sdes /* check if rrsig over previous item */ 476238106Sdes if(type == LDNS_RR_TYPE_RRSIG && dclass == *prev_dclass && 477238106Sdes pkt_rrsig_covered_equals(pkt, ldns_buffer_current(pkt), 478238106Sdes *prev_type) && 479238106Sdes smart_compare(pkt, dname, *prev_dname_first, 480238106Sdes *prev_dname_last) == 0) { 481238106Sdes /* covers previous */ 482238106Sdes *prev_dname_last = dname; 483238106Sdes return 1; 484238106Sdes } 485238106Sdes } 486238106Sdes /* find by hashing and lookup in hashtable */ 487238106Sdes *rrset_flags = pkt_rrset_flags(pkt, type, section); 488238106Sdes 489238106Sdes /* if rrsig - try to lookup matching data set first */ 490238106Sdes if(type == LDNS_RR_TYPE_RRSIG && pkt_rrsig_covered(pkt, 491238106Sdes ldns_buffer_current(pkt), &covtype)) { 492238106Sdes *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, 493238106Sdes *rrset_flags); 494238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, 495238106Sdes *rrset_flags, dname, dnamelen, covtype, dclass); 496238106Sdes if(!*rrset_prev && covtype == LDNS_RR_TYPE_NSEC) { 497238106Sdes /* if NSEC try with NSEC apex bit twiddled */ 498238106Sdes *rrset_flags ^= PACKED_RRSET_NSEC_AT_APEX; 499238106Sdes *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, 500238106Sdes *rrset_flags); 501238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, 502238106Sdes *hash, *rrset_flags, dname, dnamelen, covtype, 503238106Sdes dclass); 504238106Sdes if(!*rrset_prev) /* untwiddle if not found */ 505238106Sdes *rrset_flags ^= PACKED_RRSET_NSEC_AT_APEX; 506238106Sdes } 507238106Sdes if(!*rrset_prev && covtype == LDNS_RR_TYPE_SOA) { 508238106Sdes /* if SOA try with SOA neg flag twiddled */ 509238106Sdes *rrset_flags ^= PACKED_RRSET_SOA_NEG; 510238106Sdes *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, 511238106Sdes *rrset_flags); 512238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, 513238106Sdes *hash, *rrset_flags, dname, dnamelen, covtype, 514238106Sdes dclass); 515238106Sdes if(!*rrset_prev) /* untwiddle if not found */ 516238106Sdes *rrset_flags ^= PACKED_RRSET_SOA_NEG; 517238106Sdes } 518238106Sdes if(*rrset_prev) { 519238106Sdes *prev_dname_first = (*rrset_prev)->dname; 520238106Sdes *prev_dname_last = dname; 521238106Sdes *prev_dnamelen = dnamelen; 522238106Sdes *prev_type = covtype; 523238106Sdes *prev_dclass = dclass; 524238106Sdes return 1; 525238106Sdes } 526238106Sdes } 527238106Sdes if(type != LDNS_RR_TYPE_RRSIG) { 528238106Sdes int hasother = 0; 529238106Sdes /* find matching rrsig */ 530238106Sdes *hash = pkt_hash_rrset_rest(dname_h, LDNS_RR_TYPE_RRSIG, 531238106Sdes dclass, 0); 532238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, 533238106Sdes 0, dname, dnamelen, LDNS_RR_TYPE_RRSIG, 534238106Sdes dclass); 535238106Sdes if(*rrset_prev && rrset_has_sigover(pkt, *rrset_prev, type, 536238106Sdes &hasother)) { 537238106Sdes /* yes! */ 538238106Sdes *prev_dname_first = (*rrset_prev)->dname; 539238106Sdes *prev_dname_last = dname; 540238106Sdes *prev_dnamelen = dnamelen; 541238106Sdes *prev_type = type; 542238106Sdes *prev_dclass = dclass; 543238106Sdes *rrset_prev = change_rrsig_rrset(*rrset_prev, msg, 544238106Sdes pkt, type, *rrset_flags, hasother, section, 545238106Sdes region); 546238106Sdes if(!*rrset_prev) return 0; 547238106Sdes return 1; 548238106Sdes } 549238106Sdes } 550238106Sdes 551238106Sdes *hash = pkt_hash_rrset_rest(dname_h, type, dclass, *rrset_flags); 552238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, *rrset_flags, 553238106Sdes dname, dnamelen, type, dclass); 554238106Sdes if(*rrset_prev) 555238106Sdes *prev_dname_first = (*rrset_prev)->dname; 556238106Sdes else *prev_dname_first = dname; 557238106Sdes *prev_dname_last = dname; 558238106Sdes *prev_dnamelen = dnamelen; 559238106Sdes *prev_type = type; 560238106Sdes *prev_dclass = dclass; 561238106Sdes return 1; 562238106Sdes} 563238106Sdes 564238106Sdes/** 565238106Sdes * Parse query section. 566238106Sdes * @param pkt: packet, position at call must be at start of query section. 567238106Sdes * at end position is after query section. 568238106Sdes * @param msg: store results here. 569238106Sdes * @return: 0 if OK, or rcode on error. 570238106Sdes */ 571238106Sdesstatic int 572238106Sdesparse_query_section(ldns_buffer* pkt, struct msg_parse* msg) 573238106Sdes{ 574238106Sdes if(msg->qdcount == 0) 575238106Sdes return 0; 576238106Sdes if(msg->qdcount > 1) 577238106Sdes return LDNS_RCODE_FORMERR; 578238106Sdes log_assert(msg->qdcount == 1); 579238106Sdes if(ldns_buffer_remaining(pkt) <= 0) 580238106Sdes return LDNS_RCODE_FORMERR; 581238106Sdes msg->qname = ldns_buffer_current(pkt); 582238106Sdes if((msg->qname_len = pkt_dname_len(pkt)) == 0) 583238106Sdes return LDNS_RCODE_FORMERR; 584238106Sdes if(ldns_buffer_remaining(pkt) < sizeof(uint16_t)*2) 585238106Sdes return LDNS_RCODE_FORMERR; 586238106Sdes msg->qtype = ldns_buffer_read_u16(pkt); 587238106Sdes msg->qclass = ldns_buffer_read_u16(pkt); 588238106Sdes return 0; 589238106Sdes} 590238106Sdes 591238106Sdessize_t 592238106Sdesget_rdf_size(ldns_rdf_type rdf) 593238106Sdes{ 594238106Sdes switch(rdf) { 595238106Sdes case LDNS_RDF_TYPE_CLASS: 596238106Sdes case LDNS_RDF_TYPE_ALG: 597238106Sdes case LDNS_RDF_TYPE_INT8: 598238106Sdes return 1; 599238106Sdes break; 600238106Sdes case LDNS_RDF_TYPE_INT16: 601238106Sdes case LDNS_RDF_TYPE_TYPE: 602238106Sdes case LDNS_RDF_TYPE_CERT_ALG: 603238106Sdes return 2; 604238106Sdes break; 605238106Sdes case LDNS_RDF_TYPE_INT32: 606238106Sdes case LDNS_RDF_TYPE_TIME: 607238106Sdes case LDNS_RDF_TYPE_A: 608238106Sdes case LDNS_RDF_TYPE_PERIOD: 609238106Sdes return 4; 610238106Sdes break; 611238106Sdes case LDNS_RDF_TYPE_TSIGTIME: 612238106Sdes return 6; 613238106Sdes break; 614238106Sdes case LDNS_RDF_TYPE_AAAA: 615238106Sdes return 16; 616238106Sdes break; 617238106Sdes default: 618238106Sdes log_assert(false); /* add type above */ 619238106Sdes /* only types that appear before a domain * 620238106Sdes * name are needed. rest is simply copied. */ 621238106Sdes } 622238106Sdes return 0; 623238106Sdes} 624238106Sdes 625238106Sdes/** calculate the size of one rr */ 626238106Sdesstatic int 627238106Sdescalc_size(ldns_buffer* pkt, uint16_t type, struct rr_parse* rr) 628238106Sdes{ 629238106Sdes const ldns_rr_descriptor* desc; 630238106Sdes uint16_t pkt_len; /* length of rr inside the packet */ 631238106Sdes rr->size = sizeof(uint16_t); /* the rdatalen */ 632238106Sdes ldns_buffer_skip(pkt, 4); /* skip ttl */ 633238106Sdes pkt_len = ldns_buffer_read_u16(pkt); 634238106Sdes if(ldns_buffer_remaining(pkt) < pkt_len) 635238106Sdes return 0; 636238106Sdes desc = ldns_rr_descript(type); 637238106Sdes if(pkt_len > 0 && desc && desc->_dname_count > 0) { 638238106Sdes int count = (int)desc->_dname_count; 639238106Sdes int rdf = 0; 640238106Sdes size_t len; 641238106Sdes size_t oldpos; 642238106Sdes /* skip first part. */ 643238106Sdes while(pkt_len > 0 && count) { 644238106Sdes switch(desc->_wireformat[rdf]) { 645238106Sdes case LDNS_RDF_TYPE_DNAME: 646238106Sdes /* decompress every domain name */ 647238106Sdes oldpos = ldns_buffer_position(pkt); 648238106Sdes if((len = pkt_dname_len(pkt)) == 0) 649238106Sdes return 0; /* malformed dname */ 650238106Sdes if(ldns_buffer_position(pkt)-oldpos > pkt_len) 651238106Sdes return 0; /* dname exceeds rdata */ 652238106Sdes pkt_len -= ldns_buffer_position(pkt)-oldpos; 653238106Sdes rr->size += len; 654238106Sdes count--; 655238106Sdes len = 0; 656238106Sdes break; 657238106Sdes case LDNS_RDF_TYPE_STR: 658238106Sdes if(pkt_len < 1) 659238106Sdes return 0; /* len byte exceeds rdata */ 660238106Sdes len = ldns_buffer_current(pkt)[0] + 1; 661238106Sdes break; 662238106Sdes default: 663238106Sdes len = get_rdf_size(desc->_wireformat[rdf]); 664238106Sdes } 665238106Sdes if(len) { 666238106Sdes if(pkt_len < len) 667238106Sdes return 0; /* exceeds rdata */ 668238106Sdes pkt_len -= len; 669238106Sdes ldns_buffer_skip(pkt, (ssize_t)len); 670238106Sdes rr->size += len; 671238106Sdes } 672238106Sdes rdf++; 673238106Sdes } 674238106Sdes } 675238106Sdes /* remaining rdata */ 676238106Sdes rr->size += pkt_len; 677238106Sdes ldns_buffer_skip(pkt, (ssize_t)pkt_len); 678238106Sdes return 1; 679238106Sdes} 680238106Sdes 681238106Sdes/** skip rr ttl and rdata */ 682238106Sdesstatic int 683238106Sdesskip_ttl_rdata(ldns_buffer* pkt) 684238106Sdes{ 685238106Sdes uint16_t rdatalen; 686238106Sdes if(ldns_buffer_remaining(pkt) < 6) /* ttl + rdatalen */ 687238106Sdes return 0; 688238106Sdes ldns_buffer_skip(pkt, 4); /* ttl */ 689238106Sdes rdatalen = ldns_buffer_read_u16(pkt); 690238106Sdes if(ldns_buffer_remaining(pkt) < rdatalen) 691238106Sdes return 0; 692238106Sdes ldns_buffer_skip(pkt, (ssize_t)rdatalen); 693238106Sdes return 1; 694238106Sdes} 695238106Sdes 696238106Sdes/** see if RRSIG is a duplicate of another */ 697238106Sdesstatic int 698238106Sdessig_is_double(ldns_buffer* pkt, struct rrset_parse* rrset, uint8_t* ttldata) 699238106Sdes{ 700238106Sdes uint16_t rlen, siglen; 701238106Sdes size_t pos = ldns_buffer_position(pkt); 702238106Sdes struct rr_parse* sig; 703238106Sdes if(ldns_buffer_remaining(pkt) < 6) 704238106Sdes return 0; 705238106Sdes ldns_buffer_skip(pkt, 4); /* ttl */ 706238106Sdes rlen = ldns_buffer_read_u16(pkt); 707238106Sdes if(ldns_buffer_remaining(pkt) < rlen) { 708238106Sdes ldns_buffer_set_position(pkt, pos); 709238106Sdes return 0; 710238106Sdes } 711238106Sdes ldns_buffer_set_position(pkt, pos); 712238106Sdes 713238106Sdes sig = rrset->rrsig_first; 714238106Sdes while(sig) { 715238106Sdes /* check if rdatalen is same */ 716238106Sdes memmove(&siglen, sig->ttl_data+4, sizeof(siglen)); 717238106Sdes siglen = ntohs(siglen); 718238106Sdes /* checks if data in packet is exactly the same, this means 719238106Sdes * also dname in rdata is the same, but rrsig is not allowed 720238106Sdes * to have compressed dnames anyway. If it is compressed anyway 721238106Sdes * it will lead to duplicate rrs for qtype=RRSIG. (or ANY). 722238106Sdes * 723238106Sdes * Cannot use sig->size because size of the other one is not 724238106Sdes * calculated yet. 725238106Sdes */ 726238106Sdes if(siglen == rlen) { 727238106Sdes if(siglen>0 && memcmp(sig->ttl_data+6, ttldata+6, 728238106Sdes siglen) == 0) { 729238106Sdes /* same! */ 730238106Sdes return 1; 731238106Sdes } 732238106Sdes } 733238106Sdes sig = sig->next; 734238106Sdes } 735238106Sdes return 0; 736238106Sdes} 737238106Sdes 738238106Sdes/** Add rr (from packet here) to rrset, skips rr */ 739238106Sdesstatic int 740238106Sdesadd_rr_to_rrset(struct rrset_parse* rrset, ldns_buffer* pkt, 741238106Sdes struct msg_parse* msg, struct regional* region, 742238106Sdes ldns_pkt_section section, uint16_t type) 743238106Sdes{ 744238106Sdes struct rr_parse* rr; 745238106Sdes /* check section of rrset. */ 746238106Sdes if(rrset->section != section && type != LDNS_RR_TYPE_RRSIG && 747238106Sdes rrset->type != LDNS_RR_TYPE_RRSIG) { 748238106Sdes /* silently drop it - we drop the last part, since 749238106Sdes * trust in rr data depends on the section it is in. 750238106Sdes * the less trustworthy part is discarded. 751238106Sdes * also the last part is more likely to be incomplete. 752238106Sdes * RFC 2181: must put RRset only once in response. */ 753238106Sdes /* 754238106Sdes verbose(VERB_QUERY, "Packet contains rrset data in " 755238106Sdes "multiple sections, dropped last part."); 756238106Sdes log_buf(VERB_QUERY, "packet was", pkt); 757238106Sdes */ 758238106Sdes /* forwards */ 759238106Sdes if(!skip_ttl_rdata(pkt)) 760238106Sdes return LDNS_RCODE_FORMERR; 761238106Sdes return 0; 762238106Sdes } 763238106Sdes 764238106Sdes if( (msg->qtype == LDNS_RR_TYPE_RRSIG || 765238106Sdes msg->qtype == LDNS_RR_TYPE_ANY) 766238106Sdes && sig_is_double(pkt, rrset, ldns_buffer_current(pkt))) { 767238106Sdes if(!skip_ttl_rdata(pkt)) 768238106Sdes return LDNS_RCODE_FORMERR; 769238106Sdes return 0; 770238106Sdes } 771238106Sdes 772238106Sdes /* create rr */ 773238106Sdes if(!(rr = (struct rr_parse*)regional_alloc(region, sizeof(*rr)))) 774238106Sdes return LDNS_RCODE_SERVFAIL; 775238106Sdes rr->outside_packet = 0; 776238106Sdes rr->ttl_data = ldns_buffer_current(pkt); 777238106Sdes rr->next = 0; 778238106Sdes if(type == LDNS_RR_TYPE_RRSIG && rrset->type != LDNS_RR_TYPE_RRSIG) { 779238106Sdes if(rrset->rrsig_last) 780238106Sdes rrset->rrsig_last->next = rr; 781238106Sdes else rrset->rrsig_first = rr; 782238106Sdes rrset->rrsig_last = rr; 783238106Sdes rrset->rrsig_count++; 784238106Sdes } else { 785238106Sdes if(rrset->rr_last) 786238106Sdes rrset->rr_last->next = rr; 787238106Sdes else rrset->rr_first = rr; 788238106Sdes rrset->rr_last = rr; 789238106Sdes rrset->rr_count++; 790238106Sdes } 791238106Sdes 792238106Sdes /* calc decompressed size */ 793238106Sdes if(!calc_size(pkt, type, rr)) 794238106Sdes return LDNS_RCODE_FORMERR; 795238106Sdes rrset->size += rr->size; 796238106Sdes 797238106Sdes return 0; 798238106Sdes} 799238106Sdes 800238106Sdes/** 801238106Sdes * Parse packet RR section, for answer, authority and additional sections. 802238106Sdes * @param pkt: packet, position at call must be at start of section. 803238106Sdes * at end position is after section. 804238106Sdes * @param msg: store results here. 805238106Sdes * @param region: how to alloc results. 806238106Sdes * @param section: section enum. 807238106Sdes * @param num_rrs: how many rrs are in the section. 808238106Sdes * @param num_rrsets: returns number of rrsets in the section. 809238106Sdes * @return: 0 if OK, or rcode on error. 810238106Sdes */ 811238106Sdesstatic int 812238106Sdesparse_section(ldns_buffer* pkt, struct msg_parse* msg, 813238106Sdes struct regional* region, ldns_pkt_section section, 814238106Sdes uint16_t num_rrs, size_t* num_rrsets) 815238106Sdes{ 816238106Sdes uint16_t i; 817238106Sdes uint8_t* dname, *prev_dname_f = NULL, *prev_dname_l = NULL; 818238106Sdes size_t dnamelen, prev_dnamelen = 0; 819238106Sdes uint16_t type, prev_type = 0; 820238106Sdes uint16_t dclass, prev_dclass = 0; 821238106Sdes uint32_t rrset_flags = 0; 822238106Sdes hashvalue_t hash = 0; 823238106Sdes struct rrset_parse* rrset = NULL; 824238106Sdes int r; 825238106Sdes 826238106Sdes if(num_rrs == 0) 827238106Sdes return 0; 828238106Sdes if(ldns_buffer_remaining(pkt) <= 0) 829238106Sdes return LDNS_RCODE_FORMERR; 830238106Sdes for(i=0; i<num_rrs; i++) { 831238106Sdes /* parse this RR. */ 832238106Sdes dname = ldns_buffer_current(pkt); 833238106Sdes if((dnamelen = pkt_dname_len(pkt)) == 0) 834238106Sdes return LDNS_RCODE_FORMERR; 835238106Sdes if(ldns_buffer_remaining(pkt) < 10) /* type, class, ttl, len */ 836238106Sdes return LDNS_RCODE_FORMERR; 837238106Sdes type = ldns_buffer_read_u16(pkt); 838238106Sdes ldns_buffer_read(pkt, &dclass, sizeof(dclass)); 839238106Sdes 840238106Sdes if(0) { /* debug show what is being parsed. */ 841238106Sdes if(type == LDNS_RR_TYPE_RRSIG) { 842238106Sdes uint16_t t; 843238106Sdes if(pkt_rrsig_covered(pkt, 844238106Sdes ldns_buffer_current(pkt), &t)) 845238106Sdes fprintf(stderr, "parse of %s(%d) [%s(%d)]", 846238106Sdes ldns_rr_descript(type)? 847238106Sdes ldns_rr_descript(type)->_name: "??", 848238106Sdes (int)type, 849238106Sdes ldns_rr_descript(t)? 850238106Sdes ldns_rr_descript(t)->_name: "??", 851238106Sdes (int)t); 852238106Sdes } else 853238106Sdes fprintf(stderr, "parse of %s(%d)", 854238106Sdes ldns_rr_descript(type)? 855238106Sdes ldns_rr_descript(type)->_name: "??", 856238106Sdes (int)type); 857238106Sdes fprintf(stderr, " %s(%d) ", 858238106Sdes ldns_lookup_by_id(ldns_rr_classes, 859238106Sdes (int)ntohs(dclass))?ldns_lookup_by_id( 860238106Sdes ldns_rr_classes, (int)ntohs(dclass))->name: 861238106Sdes "??", (int)ntohs(dclass)); 862238106Sdes dname_print(stderr, pkt, dname); 863238106Sdes fprintf(stderr, "\n"); 864238106Sdes } 865238106Sdes 866238106Sdes /* see if it is part of an existing RR set */ 867238106Sdes if(!find_rrset(msg, pkt, dname, dnamelen, type, dclass, &hash, 868238106Sdes &rrset_flags, &prev_dname_f, &prev_dname_l, 869238106Sdes &prev_dnamelen, &prev_type, &prev_dclass, &rrset, 870238106Sdes section, region)) 871238106Sdes return LDNS_RCODE_SERVFAIL; 872238106Sdes if(!rrset) { 873238106Sdes /* it is a new RR set. hash&flags already calculated.*/ 874238106Sdes (*num_rrsets)++; 875238106Sdes rrset = new_rrset(msg, dname, dnamelen, type, dclass, 876238106Sdes hash, rrset_flags, section, region); 877238106Sdes if(!rrset) 878238106Sdes return LDNS_RCODE_SERVFAIL; 879238106Sdes } 880238106Sdes else if(0) { 881238106Sdes fprintf(stderr, "is part of existing: "); 882238106Sdes dname_print(stderr, pkt, rrset->dname); 883238106Sdes fprintf(stderr, " type %s(%d)\n", 884238106Sdes ldns_rr_descript(rrset->type)? 885238106Sdes ldns_rr_descript(rrset->type)->_name: "??", 886238106Sdes (int)rrset->type); 887238106Sdes } 888238106Sdes /* add to rrset. */ 889238106Sdes if((r=add_rr_to_rrset(rrset, pkt, msg, region, section, 890238106Sdes type)) != 0) 891238106Sdes return r; 892238106Sdes } 893238106Sdes return 0; 894238106Sdes} 895238106Sdes 896238106Sdesint 897238106Sdesparse_packet(ldns_buffer* pkt, struct msg_parse* msg, struct regional* region) 898238106Sdes{ 899238106Sdes int ret; 900238106Sdes if(ldns_buffer_remaining(pkt) < LDNS_HEADER_SIZE) 901238106Sdes return LDNS_RCODE_FORMERR; 902238106Sdes /* read the header */ 903238106Sdes ldns_buffer_read(pkt, &msg->id, sizeof(uint16_t)); 904238106Sdes msg->flags = ldns_buffer_read_u16(pkt); 905238106Sdes msg->qdcount = ldns_buffer_read_u16(pkt); 906238106Sdes msg->ancount = ldns_buffer_read_u16(pkt); 907238106Sdes msg->nscount = ldns_buffer_read_u16(pkt); 908238106Sdes msg->arcount = ldns_buffer_read_u16(pkt); 909238106Sdes if(msg->qdcount > 1) 910238106Sdes return LDNS_RCODE_FORMERR; 911238106Sdes if((ret = parse_query_section(pkt, msg)) != 0) 912238106Sdes return ret; 913238106Sdes if((ret = parse_section(pkt, msg, region, LDNS_SECTION_ANSWER, 914238106Sdes msg->ancount, &msg->an_rrsets)) != 0) 915238106Sdes return ret; 916238106Sdes if((ret = parse_section(pkt, msg, region, LDNS_SECTION_AUTHORITY, 917238106Sdes msg->nscount, &msg->ns_rrsets)) != 0) 918238106Sdes return ret; 919238106Sdes if(ldns_buffer_remaining(pkt) == 0 && msg->arcount == 1) { 920238106Sdes /* BIND accepts leniently that an EDNS record is missing. 921238106Sdes * so, we do too. */ 922238106Sdes } else if((ret = parse_section(pkt, msg, region, 923238106Sdes LDNS_SECTION_ADDITIONAL, msg->arcount, &msg->ar_rrsets)) != 0) 924238106Sdes return ret; 925238106Sdes /* if(ldns_buffer_remaining(pkt) > 0) { */ 926238106Sdes /* there is spurious data at end of packet. ignore */ 927238106Sdes /* } */ 928238106Sdes msg->rrset_count = msg->an_rrsets + msg->ns_rrsets + msg->ar_rrsets; 929238106Sdes return 0; 930238106Sdes} 931238106Sdes 932238106Sdesint 933238106Sdesparse_extract_edns(struct msg_parse* msg, struct edns_data* edns) 934238106Sdes{ 935238106Sdes struct rrset_parse* rrset = msg->rrset_first; 936238106Sdes struct rrset_parse* prev = 0; 937238106Sdes struct rrset_parse* found = 0; 938238106Sdes struct rrset_parse* found_prev = 0; 939238106Sdes /* since the class encodes the UDP size, we cannot use hash table to 940238106Sdes * find the EDNS OPT record. Scan the packet. */ 941238106Sdes while(rrset) { 942238106Sdes if(rrset->type == LDNS_RR_TYPE_OPT) { 943238106Sdes /* only one OPT RR allowed. */ 944238106Sdes if(found) return LDNS_RCODE_FORMERR; 945238106Sdes /* found it! */ 946238106Sdes found_prev = prev; 947238106Sdes found = rrset; 948238106Sdes } 949238106Sdes prev = rrset; 950238106Sdes rrset = rrset->rrset_all_next; 951238106Sdes } 952238106Sdes if(!found) { 953238106Sdes memset(edns, 0, sizeof(*edns)); 954238106Sdes edns->udp_size = 512; 955238106Sdes return 0; 956238106Sdes } 957238106Sdes /* check the found RRset */ 958238106Sdes /* most lenient check possible. ignore dname, use last opt */ 959238106Sdes if(found->section != LDNS_SECTION_ADDITIONAL) 960238106Sdes return LDNS_RCODE_FORMERR; 961238106Sdes if(found->rr_count == 0) 962238106Sdes return LDNS_RCODE_FORMERR; 963238106Sdes if(0) { /* strict checking of dname and RRcount */ 964238106Sdes if(found->dname_len != 1 || !found->dname 965238106Sdes || found->dname[0] != 0) return LDNS_RCODE_FORMERR; 966238106Sdes if(found->rr_count != 1) return LDNS_RCODE_FORMERR; 967238106Sdes } 968238106Sdes log_assert(found->rr_first && found->rr_last); 969238106Sdes 970238106Sdes /* remove from packet */ 971238106Sdes if(found_prev) found_prev->rrset_all_next = found->rrset_all_next; 972238106Sdes else msg->rrset_first = found->rrset_all_next; 973238106Sdes if(found == msg->rrset_last) 974238106Sdes msg->rrset_last = found_prev; 975238106Sdes msg->arcount --; 976238106Sdes msg->ar_rrsets --; 977238106Sdes msg->rrset_count --; 978238106Sdes 979238106Sdes /* take the data ! */ 980238106Sdes edns->edns_present = 1; 981238106Sdes edns->ext_rcode = found->rr_last->ttl_data[0]; 982238106Sdes edns->edns_version = found->rr_last->ttl_data[1]; 983238106Sdes edns->bits = ldns_read_uint16(&found->rr_last->ttl_data[2]); 984238106Sdes edns->udp_size = ntohs(found->rrset_class); 985238106Sdes /* ignore rdata and rrsigs */ 986238106Sdes return 0; 987238106Sdes} 988238106Sdes 989238106Sdesint 990238106Sdesparse_edns_from_pkt(ldns_buffer* pkt, struct edns_data* edns) 991238106Sdes{ 992238106Sdes log_assert(LDNS_QDCOUNT(ldns_buffer_begin(pkt)) == 1); 993238106Sdes log_assert(LDNS_ANCOUNT(ldns_buffer_begin(pkt)) == 0); 994238106Sdes log_assert(LDNS_NSCOUNT(ldns_buffer_begin(pkt)) == 0); 995238106Sdes /* check edns section is present */ 996238106Sdes if(LDNS_ARCOUNT(ldns_buffer_begin(pkt)) > 1) { 997238106Sdes return LDNS_RCODE_FORMERR; 998238106Sdes } 999238106Sdes if(LDNS_ARCOUNT(ldns_buffer_begin(pkt)) == 0) { 1000238106Sdes memset(edns, 0, sizeof(*edns)); 1001238106Sdes edns->udp_size = 512; 1002238106Sdes return 0; 1003238106Sdes } 1004238106Sdes /* domain name must be the root of length 1. */ 1005238106Sdes if(pkt_dname_len(pkt) != 1) 1006238106Sdes return LDNS_RCODE_FORMERR; 1007238106Sdes if(ldns_buffer_remaining(pkt) < 10) /* type, class, ttl, rdatalen */ 1008238106Sdes return LDNS_RCODE_FORMERR; 1009238106Sdes if(ldns_buffer_read_u16(pkt) != LDNS_RR_TYPE_OPT) 1010238106Sdes return LDNS_RCODE_FORMERR; 1011238106Sdes edns->edns_present = 1; 1012238106Sdes edns->udp_size = ldns_buffer_read_u16(pkt); /* class is udp size */ 1013238106Sdes edns->ext_rcode = ldns_buffer_read_u8(pkt); /* ttl used for bits */ 1014238106Sdes edns->edns_version = ldns_buffer_read_u8(pkt); 1015238106Sdes edns->bits = ldns_buffer_read_u16(pkt); 1016238106Sdes /* ignore rdata and rrsigs */ 1017238106Sdes return 0; 1018238106Sdes} 1019