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 24269257Sdes * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25269257Sdes * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 26269257Sdes * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 27269257Sdes * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28269257Sdes * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 29269257Sdes * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 30269257Sdes * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 31269257Sdes * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 32269257Sdes * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33269257Sdes * SOFTWARE, EVEN IF ADVISED OF THE 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 "util/data/msgparse.h" 41238106Sdes#include "util/data/dname.h" 42238106Sdes#include "util/data/packed_rrset.h" 43238106Sdes#include "util/storage/lookup3.h" 44238106Sdes#include "util/regional.h" 45291767Sdes#include "sldns/rrdef.h" 46291767Sdes#include "sldns/sbuffer.h" 47291767Sdes#include "sldns/parseutil.h" 48291767Sdes#include "sldns/wire2str.h" 49238106Sdes 50238106Sdes/** smart comparison of (compressed, valid) dnames from packet */ 51238106Sdesstatic int 52269257Sdessmart_compare(sldns_buffer* pkt, uint8_t* dnow, 53238106Sdes uint8_t* dprfirst, uint8_t* dprlast) 54238106Sdes{ 55238106Sdes if(LABEL_IS_PTR(*dnow)) { 56238106Sdes /* ptr points to a previous dname */ 57269257Sdes uint8_t* p = sldns_buffer_at(pkt, PTR_OFFSET(dnow[0], dnow[1])); 58238106Sdes if( p == dprfirst || p == dprlast ) 59238106Sdes return 0; 60238106Sdes /* prev dname is also a ptr, both ptrs are the same. */ 61238106Sdes if(LABEL_IS_PTR(*dprlast) && 62238106Sdes dprlast[0] == dnow[0] && dprlast[1] == dnow[1]) 63238106Sdes return 0; 64238106Sdes } 65238106Sdes return dname_pkt_compare(pkt, dnow, dprlast); 66238106Sdes} 67238106Sdes 68238106Sdes/** 69238106Sdes * Allocate new rrset in region, fill with data. 70238106Sdes */ 71238106Sdesstatic struct rrset_parse* 72238106Sdesnew_rrset(struct msg_parse* msg, uint8_t* dname, size_t dnamelen, 73238106Sdes uint16_t type, uint16_t dclass, hashvalue_t hash, 74269257Sdes uint32_t rrset_flags, sldns_pkt_section section, 75238106Sdes struct regional* region) 76238106Sdes{ 77238106Sdes struct rrset_parse* p = regional_alloc(region, sizeof(*p)); 78238106Sdes if(!p) return NULL; 79238106Sdes p->rrset_bucket_next = msg->hashtable[hash & (PARSE_TABLE_SIZE-1)]; 80238106Sdes msg->hashtable[hash & (PARSE_TABLE_SIZE-1)] = p; 81238106Sdes p->rrset_all_next = 0; 82238106Sdes if(msg->rrset_last) 83238106Sdes msg->rrset_last->rrset_all_next = p; 84238106Sdes else msg->rrset_first = p; 85238106Sdes msg->rrset_last = p; 86238106Sdes p->hash = hash; 87238106Sdes p->section = section; 88238106Sdes p->dname = dname; 89238106Sdes p->dname_len = dnamelen; 90238106Sdes p->type = type; 91238106Sdes p->rrset_class = dclass; 92238106Sdes p->flags = rrset_flags; 93238106Sdes p->rr_count = 0; 94238106Sdes p->size = 0; 95238106Sdes p->rr_first = 0; 96238106Sdes p->rr_last = 0; 97238106Sdes p->rrsig_count = 0; 98238106Sdes p->rrsig_first = 0; 99238106Sdes p->rrsig_last = 0; 100238106Sdes return p; 101238106Sdes} 102238106Sdes 103238106Sdes/** See if next rrset is nsec at zone apex */ 104238106Sdesstatic int 105269257Sdesnsec_at_apex(sldns_buffer* pkt) 106238106Sdes{ 107238106Sdes /* we are at ttl position in packet. */ 108269257Sdes size_t pos = sldns_buffer_position(pkt); 109238106Sdes uint16_t rdatalen; 110269257Sdes if(sldns_buffer_remaining(pkt) < 7) /* ttl+len+root */ 111238106Sdes return 0; /* eek! */ 112269257Sdes sldns_buffer_skip(pkt, 4); /* ttl */; 113269257Sdes rdatalen = sldns_buffer_read_u16(pkt); 114269257Sdes if(sldns_buffer_remaining(pkt) < rdatalen) { 115269257Sdes sldns_buffer_set_position(pkt, pos); 116238106Sdes return 0; /* parse error happens later */ 117238106Sdes } 118238106Sdes /* must validate the nsec next domain name format */ 119238106Sdes if(pkt_dname_len(pkt) == 0) { 120269257Sdes sldns_buffer_set_position(pkt, pos); 121238106Sdes return 0; /* parse error */ 122238106Sdes } 123238106Sdes 124238106Sdes /* see if SOA bit is set. */ 125269257Sdes if(sldns_buffer_position(pkt) < pos+4+rdatalen) { 126238106Sdes /* nsec type bitmap contains items */ 127238106Sdes uint8_t win, blen, bits; 128238106Sdes /* need: windownum, bitmap len, firstbyte */ 129269257Sdes if(sldns_buffer_position(pkt)+3 > pos+4+rdatalen) { 130269257Sdes sldns_buffer_set_position(pkt, pos); 131238106Sdes return 0; /* malformed nsec */ 132238106Sdes } 133269257Sdes win = sldns_buffer_read_u8(pkt); 134269257Sdes blen = sldns_buffer_read_u8(pkt); 135269257Sdes bits = sldns_buffer_read_u8(pkt); 136238106Sdes /* 0window always first window. bitlen >=1 or parse 137238106Sdes error really. bit 0x2 is SOA. */ 138238106Sdes if(win == 0 && blen >= 1 && (bits & 0x02)) { 139269257Sdes sldns_buffer_set_position(pkt, pos); 140238106Sdes return 1; 141238106Sdes } 142238106Sdes } 143238106Sdes 144269257Sdes sldns_buffer_set_position(pkt, pos); 145238106Sdes return 0; 146238106Sdes} 147238106Sdes 148238106Sdes/** Calculate rrset flags */ 149238106Sdesstatic uint32_t 150269257Sdespkt_rrset_flags(sldns_buffer* pkt, uint16_t type, sldns_pkt_section sec) 151238106Sdes{ 152238106Sdes uint32_t f = 0; 153238106Sdes if(type == LDNS_RR_TYPE_NSEC && nsec_at_apex(pkt)) { 154238106Sdes f |= PACKED_RRSET_NSEC_AT_APEX; 155238106Sdes } else if(type == LDNS_RR_TYPE_SOA && sec == LDNS_SECTION_AUTHORITY) { 156238106Sdes f |= PACKED_RRSET_SOA_NEG; 157238106Sdes } 158238106Sdes return f; 159238106Sdes} 160238106Sdes 161238106Sdeshashvalue_t 162269257Sdespkt_hash_rrset(sldns_buffer* pkt, uint8_t* dname, uint16_t type, 163238106Sdes uint16_t dclass, uint32_t rrset_flags) 164238106Sdes{ 165238106Sdes /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ 166238106Sdes /* this routine handles compressed names */ 167238106Sdes hashvalue_t h = 0xab; 168238106Sdes h = dname_pkt_hash(pkt, dname, h); 169238106Sdes h = hashlittle(&type, sizeof(type), h); /* host order */ 170238106Sdes h = hashlittle(&dclass, sizeof(dclass), h); /* netw order */ 171238106Sdes h = hashlittle(&rrset_flags, sizeof(uint32_t), h); 172238106Sdes return h; 173238106Sdes} 174238106Sdes 175238106Sdes/** create partial dname hash for rrset hash */ 176238106Sdesstatic hashvalue_t 177269257Sdespkt_hash_rrset_first(sldns_buffer* pkt, uint8_t* dname) 178238106Sdes{ 179238106Sdes /* works together with pkt_hash_rrset_rest */ 180238106Sdes /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ 181238106Sdes /* this routine handles compressed names */ 182238106Sdes hashvalue_t h = 0xab; 183238106Sdes h = dname_pkt_hash(pkt, dname, h); 184238106Sdes return h; 185238106Sdes} 186238106Sdes 187238106Sdes/** create a rrset hash from a partial dname hash */ 188238106Sdesstatic hashvalue_t 189238106Sdespkt_hash_rrset_rest(hashvalue_t dname_h, uint16_t type, uint16_t dclass, 190238106Sdes uint32_t rrset_flags) 191238106Sdes{ 192238106Sdes /* works together with pkt_hash_rrset_first */ 193238106Sdes /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ 194238106Sdes hashvalue_t h; 195238106Sdes h = hashlittle(&type, sizeof(type), dname_h); /* host order */ 196238106Sdes h = hashlittle(&dclass, sizeof(dclass), h); /* netw order */ 197238106Sdes h = hashlittle(&rrset_flags, sizeof(uint32_t), h); 198238106Sdes return h; 199238106Sdes} 200238106Sdes 201238106Sdes/** compare rrset_parse with data */ 202238106Sdesstatic int 203269257Sdesrrset_parse_equals(struct rrset_parse* p, sldns_buffer* pkt, hashvalue_t h, 204238106Sdes uint32_t rrset_flags, uint8_t* dname, size_t dnamelen, 205238106Sdes uint16_t type, uint16_t dclass) 206238106Sdes{ 207238106Sdes if(p->hash == h && p->dname_len == dnamelen && p->type == type && 208238106Sdes p->rrset_class == dclass && p->flags == rrset_flags && 209238106Sdes dname_pkt_compare(pkt, dname, p->dname) == 0) 210238106Sdes return 1; 211238106Sdes return 0; 212238106Sdes} 213238106Sdes 214238106Sdes 215238106Sdesstruct rrset_parse* 216269257Sdesmsgparse_hashtable_lookup(struct msg_parse* msg, sldns_buffer* pkt, 217238106Sdes hashvalue_t h, uint32_t rrset_flags, uint8_t* dname, size_t dnamelen, 218238106Sdes uint16_t type, uint16_t dclass) 219238106Sdes{ 220238106Sdes struct rrset_parse* p = msg->hashtable[h & (PARSE_TABLE_SIZE-1)]; 221238106Sdes while(p) { 222238106Sdes if(rrset_parse_equals(p, pkt, h, rrset_flags, dname, dnamelen, 223238106Sdes type, dclass)) 224238106Sdes return p; 225238106Sdes p = p->rrset_bucket_next; 226238106Sdes } 227238106Sdes return NULL; 228238106Sdes} 229238106Sdes 230238106Sdes/** return type networkformat that rrsig in packet covers */ 231238106Sdesstatic int 232269257Sdespkt_rrsig_covered(sldns_buffer* pkt, uint8_t* here, uint16_t* type) 233238106Sdes{ 234269257Sdes size_t pos = sldns_buffer_position(pkt); 235269257Sdes sldns_buffer_set_position(pkt, (size_t)(here-sldns_buffer_begin(pkt))); 236238106Sdes /* ttl + len + size of small rrsig(rootlabel, no signature) */ 237269257Sdes if(sldns_buffer_remaining(pkt) < 4+2+19) 238238106Sdes return 0; 239269257Sdes sldns_buffer_skip(pkt, 4); /* ttl */ 240269257Sdes if(sldns_buffer_read_u16(pkt) < 19) /* too short */ { 241269257Sdes sldns_buffer_set_position(pkt, pos); 242238106Sdes return 0; 243238106Sdes } 244269257Sdes *type = sldns_buffer_read_u16(pkt); 245269257Sdes sldns_buffer_set_position(pkt, pos); 246238106Sdes return 1; 247238106Sdes} 248238106Sdes 249238106Sdes/** true if covered type equals prevtype */ 250238106Sdesstatic int 251269257Sdespkt_rrsig_covered_equals(sldns_buffer* pkt, uint8_t* here, uint16_t type) 252238106Sdes{ 253238106Sdes uint16_t t; 254238106Sdes if(pkt_rrsig_covered(pkt, here, &t) && t == type) 255238106Sdes return 1; 256238106Sdes return 0; 257238106Sdes} 258238106Sdes 259238106Sdesvoid 260238106Sdesmsgparse_bucket_remove(struct msg_parse* msg, struct rrset_parse* rrset) 261238106Sdes{ 262238106Sdes struct rrset_parse** p; 263238106Sdes p = &msg->hashtable[ rrset->hash & (PARSE_TABLE_SIZE-1) ]; 264238106Sdes while(*p) { 265238106Sdes if(*p == rrset) { 266238106Sdes *p = rrset->rrset_bucket_next; 267238106Sdes return; 268238106Sdes } 269238106Sdes p = &( (*p)->rrset_bucket_next ); 270238106Sdes } 271238106Sdes} 272238106Sdes 273238106Sdes/** change section of rrset from previous to current section */ 274238106Sdesstatic void 275238106Sdeschange_section(struct msg_parse* msg, struct rrset_parse* rrset, 276269257Sdes sldns_pkt_section section) 277238106Sdes{ 278238106Sdes struct rrset_parse *p, *prev; 279238106Sdes /* remove from list */ 280238106Sdes if(section == rrset->section) 281238106Sdes return; 282238106Sdes p = msg->rrset_first; 283238106Sdes prev = 0; 284238106Sdes while(p) { 285238106Sdes if(p == rrset) { 286238106Sdes if(prev) prev->rrset_all_next = p->rrset_all_next; 287238106Sdes else msg->rrset_first = p->rrset_all_next; 288238106Sdes if(msg->rrset_last == rrset) 289238106Sdes msg->rrset_last = prev; 290238106Sdes break; 291238106Sdes } 292238106Sdes prev = p; 293238106Sdes p = p->rrset_all_next; 294238106Sdes } 295238106Sdes /* remove from count */ 296238106Sdes switch(rrset->section) { 297238106Sdes case LDNS_SECTION_ANSWER: msg->an_rrsets--; break; 298238106Sdes case LDNS_SECTION_AUTHORITY: msg->ns_rrsets--; break; 299238106Sdes case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets--; break; 300238106Sdes default: log_assert(0); 301238106Sdes } 302238106Sdes /* insert at end of list */ 303238106Sdes rrset->rrset_all_next = 0; 304238106Sdes if(msg->rrset_last) 305238106Sdes msg->rrset_last->rrset_all_next = rrset; 306238106Sdes else msg->rrset_first = rrset; 307238106Sdes msg->rrset_last = rrset; 308238106Sdes /* up count of new section */ 309238106Sdes switch(section) { 310238106Sdes case LDNS_SECTION_AUTHORITY: msg->ns_rrsets++; break; 311238106Sdes case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets++; break; 312238106Sdes default: log_assert(0); 313238106Sdes } 314238106Sdes rrset->section = section; 315238106Sdes} 316238106Sdes 317238106Sdes/** see if rrset of type RRSIG contains sig over given type */ 318238106Sdesstatic int 319269257Sdesrrset_has_sigover(sldns_buffer* pkt, struct rrset_parse* rrset, uint16_t type, 320238106Sdes int* hasother) 321238106Sdes{ 322238106Sdes int res = 0; 323238106Sdes struct rr_parse* rr = rrset->rr_first; 324238106Sdes log_assert( rrset->type == LDNS_RR_TYPE_RRSIG ); 325238106Sdes while(rr) { 326238106Sdes if(pkt_rrsig_covered_equals(pkt, rr->ttl_data, type)) 327238106Sdes res = 1; 328238106Sdes else *hasother = 1; 329238106Sdes rr = rr->next; 330238106Sdes } 331238106Sdes return res; 332238106Sdes} 333238106Sdes 334238106Sdes/** move rrsigs from sigset to dataset */ 335238106Sdesstatic int 336269257Sdesmoveover_rrsigs(sldns_buffer* pkt, struct regional* region, 337238106Sdes struct rrset_parse* sigset, struct rrset_parse* dataset, int duplicate) 338238106Sdes{ 339238106Sdes struct rr_parse* sig = sigset->rr_first; 340238106Sdes struct rr_parse* prev = NULL; 341238106Sdes struct rr_parse* insert; 342238106Sdes struct rr_parse* nextsig; 343238106Sdes while(sig) { 344238106Sdes nextsig = sig->next; 345238106Sdes if(pkt_rrsig_covered_equals(pkt, sig->ttl_data, 346238106Sdes dataset->type)) { 347238106Sdes if(duplicate) { 348238106Sdes /* new */ 349238106Sdes insert = (struct rr_parse*)regional_alloc( 350238106Sdes region, sizeof(struct rr_parse)); 351238106Sdes if(!insert) return 0; 352238106Sdes insert->outside_packet = 0; 353238106Sdes insert->ttl_data = sig->ttl_data; 354238106Sdes insert->size = sig->size; 355238106Sdes /* prev not used */ 356238106Sdes } else { 357238106Sdes /* remove from sigset */ 358238106Sdes if(prev) prev->next = sig->next; 359238106Sdes else sigset->rr_first = sig->next; 360238106Sdes if(sigset->rr_last == sig) 361238106Sdes sigset->rr_last = prev; 362238106Sdes sigset->rr_count--; 363238106Sdes sigset->size -= sig->size; 364238106Sdes insert = sig; 365238106Sdes /* prev not changed */ 366238106Sdes } 367238106Sdes /* add to dataset */ 368238106Sdes dataset->rrsig_count++; 369238106Sdes insert->next = 0; 370238106Sdes if(dataset->rrsig_last) 371238106Sdes dataset->rrsig_last->next = insert; 372238106Sdes else dataset->rrsig_first = insert; 373238106Sdes dataset->rrsig_last = insert; 374238106Sdes dataset->size += insert->size; 375238106Sdes } else { 376238106Sdes prev = sig; 377238106Sdes } 378238106Sdes sig = nextsig; 379238106Sdes } 380238106Sdes return 1; 381238106Sdes} 382238106Sdes 383238106Sdes/** change an rrsig rrset for use as data rrset */ 384238106Sdesstatic struct rrset_parse* 385238106Sdeschange_rrsig_rrset(struct rrset_parse* sigset, struct msg_parse* msg, 386269257Sdes sldns_buffer* pkt, uint16_t datatype, uint32_t rrset_flags, 387269257Sdes int hasother, sldns_pkt_section section, struct regional* region) 388238106Sdes{ 389238106Sdes struct rrset_parse* dataset = sigset; 390238106Sdes hashvalue_t hash = pkt_hash_rrset(pkt, sigset->dname, datatype, 391238106Sdes sigset->rrset_class, rrset_flags); 392238106Sdes log_assert( sigset->type == LDNS_RR_TYPE_RRSIG ); 393238106Sdes log_assert( datatype != LDNS_RR_TYPE_RRSIG ); 394238106Sdes if(hasother) { 395238106Sdes /* need to make new rrset to hold data type */ 396238106Sdes dataset = new_rrset(msg, sigset->dname, sigset->dname_len, 397238106Sdes datatype, sigset->rrset_class, hash, rrset_flags, 398238106Sdes section, region); 399238106Sdes if(!dataset) 400238106Sdes return NULL; 401238106Sdes switch(section) { 402238106Sdes case LDNS_SECTION_ANSWER: msg->an_rrsets++; break; 403238106Sdes case LDNS_SECTION_AUTHORITY: msg->ns_rrsets++; break; 404238106Sdes case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets++; break; 405238106Sdes default: log_assert(0); 406238106Sdes } 407238106Sdes if(!moveover_rrsigs(pkt, region, sigset, dataset, 408238106Sdes msg->qtype == LDNS_RR_TYPE_RRSIG || 409238106Sdes (msg->qtype == LDNS_RR_TYPE_ANY && 410238106Sdes section != LDNS_SECTION_ANSWER) )) 411238106Sdes return NULL; 412238106Sdes return dataset; 413238106Sdes } 414238106Sdes /* changeover the type of the rrset to data set */ 415238106Sdes msgparse_bucket_remove(msg, dataset); 416238106Sdes /* insert into new hash bucket */ 417238106Sdes dataset->rrset_bucket_next = msg->hashtable[hash&(PARSE_TABLE_SIZE-1)]; 418238106Sdes msg->hashtable[hash&(PARSE_TABLE_SIZE-1)] = dataset; 419238106Sdes dataset->hash = hash; 420238106Sdes /* use section of data item for result */ 421238106Sdes change_section(msg, dataset, section); 422238106Sdes dataset->type = datatype; 423238106Sdes dataset->flags = rrset_flags; 424238106Sdes dataset->rrsig_count += dataset->rr_count; 425238106Sdes dataset->rr_count = 0; 426238106Sdes /* move sigs to end of siglist */ 427238106Sdes if(dataset->rrsig_last) 428238106Sdes dataset->rrsig_last->next = dataset->rr_first; 429238106Sdes else dataset->rrsig_first = dataset->rr_first; 430238106Sdes dataset->rrsig_last = dataset->rr_last; 431238106Sdes dataset->rr_first = 0; 432238106Sdes dataset->rr_last = 0; 433238106Sdes return dataset; 434238106Sdes} 435238106Sdes 436238106Sdes/** Find rrset. If equal to previous it is fast. hash if not so. 437238106Sdes * @param msg: the message with hash table. 438238106Sdes * @param pkt: the packet in wireformat (needed for compression ptrs). 439238106Sdes * @param dname: pointer to start of dname (compressed) in packet. 440238106Sdes * @param dnamelen: uncompressed wirefmt length of dname. 441238106Sdes * @param type: type of current rr. 442238106Sdes * @param dclass: class of current rr. 443238106Sdes * @param hash: hash value is returned if the rrset could not be found. 444238106Sdes * @param rrset_flags: is returned if the rrset could not be found. 445238106Sdes * @param prev_dname_first: dname of last seen RR. First seen dname. 446238106Sdes * @param prev_dname_last: dname of last seen RR. Last seen dname. 447238106Sdes * @param prev_dnamelen: dname len of last seen RR. 448238106Sdes * @param prev_type: type of last seen RR. 449238106Sdes * @param prev_dclass: class of last seen RR. 450238106Sdes * @param rrset_prev: last seen RRset. 451238106Sdes * @param section: the current section in the packet. 452238106Sdes * @param region: used to allocate temporary parsing data. 453238106Sdes * @return 0 on out of memory. 454238106Sdes */ 455238106Sdesstatic int 456269257Sdesfind_rrset(struct msg_parse* msg, sldns_buffer* pkt, uint8_t* dname, 457238106Sdes size_t dnamelen, uint16_t type, uint16_t dclass, hashvalue_t* hash, 458238106Sdes uint32_t* rrset_flags, 459238106Sdes uint8_t** prev_dname_first, uint8_t** prev_dname_last, 460238106Sdes size_t* prev_dnamelen, uint16_t* prev_type, 461238106Sdes uint16_t* prev_dclass, struct rrset_parse** rrset_prev, 462269257Sdes sldns_pkt_section section, struct regional* region) 463238106Sdes{ 464238106Sdes hashvalue_t dname_h = pkt_hash_rrset_first(pkt, dname); 465238106Sdes uint16_t covtype; 466238106Sdes if(*rrset_prev) { 467238106Sdes /* check if equal to previous item */ 468238106Sdes if(type == *prev_type && dclass == *prev_dclass && 469238106Sdes dnamelen == *prev_dnamelen && 470238106Sdes smart_compare(pkt, dname, *prev_dname_first, 471238106Sdes *prev_dname_last) == 0 && 472238106Sdes type != LDNS_RR_TYPE_RRSIG) { 473238106Sdes /* same as previous */ 474238106Sdes *prev_dname_last = dname; 475238106Sdes return 1; 476238106Sdes } 477238106Sdes /* check if rrsig over previous item */ 478238106Sdes if(type == LDNS_RR_TYPE_RRSIG && dclass == *prev_dclass && 479269257Sdes pkt_rrsig_covered_equals(pkt, sldns_buffer_current(pkt), 480238106Sdes *prev_type) && 481238106Sdes smart_compare(pkt, dname, *prev_dname_first, 482238106Sdes *prev_dname_last) == 0) { 483238106Sdes /* covers previous */ 484238106Sdes *prev_dname_last = dname; 485238106Sdes return 1; 486238106Sdes } 487238106Sdes } 488238106Sdes /* find by hashing and lookup in hashtable */ 489238106Sdes *rrset_flags = pkt_rrset_flags(pkt, type, section); 490238106Sdes 491238106Sdes /* if rrsig - try to lookup matching data set first */ 492238106Sdes if(type == LDNS_RR_TYPE_RRSIG && pkt_rrsig_covered(pkt, 493269257Sdes sldns_buffer_current(pkt), &covtype)) { 494238106Sdes *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, 495238106Sdes *rrset_flags); 496238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, 497238106Sdes *rrset_flags, dname, dnamelen, covtype, dclass); 498238106Sdes if(!*rrset_prev && covtype == LDNS_RR_TYPE_NSEC) { 499238106Sdes /* if NSEC try with NSEC apex bit twiddled */ 500238106Sdes *rrset_flags ^= PACKED_RRSET_NSEC_AT_APEX; 501238106Sdes *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, 502238106Sdes *rrset_flags); 503238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, 504238106Sdes *hash, *rrset_flags, dname, dnamelen, covtype, 505238106Sdes dclass); 506238106Sdes if(!*rrset_prev) /* untwiddle if not found */ 507238106Sdes *rrset_flags ^= PACKED_RRSET_NSEC_AT_APEX; 508238106Sdes } 509238106Sdes if(!*rrset_prev && covtype == LDNS_RR_TYPE_SOA) { 510238106Sdes /* if SOA try with SOA neg flag twiddled */ 511238106Sdes *rrset_flags ^= PACKED_RRSET_SOA_NEG; 512238106Sdes *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, 513238106Sdes *rrset_flags); 514238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, 515238106Sdes *hash, *rrset_flags, dname, dnamelen, covtype, 516238106Sdes dclass); 517238106Sdes if(!*rrset_prev) /* untwiddle if not found */ 518238106Sdes *rrset_flags ^= PACKED_RRSET_SOA_NEG; 519238106Sdes } 520238106Sdes if(*rrset_prev) { 521238106Sdes *prev_dname_first = (*rrset_prev)->dname; 522238106Sdes *prev_dname_last = dname; 523238106Sdes *prev_dnamelen = dnamelen; 524238106Sdes *prev_type = covtype; 525238106Sdes *prev_dclass = dclass; 526238106Sdes return 1; 527238106Sdes } 528238106Sdes } 529238106Sdes if(type != LDNS_RR_TYPE_RRSIG) { 530238106Sdes int hasother = 0; 531238106Sdes /* find matching rrsig */ 532238106Sdes *hash = pkt_hash_rrset_rest(dname_h, LDNS_RR_TYPE_RRSIG, 533238106Sdes dclass, 0); 534238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, 535238106Sdes 0, dname, dnamelen, LDNS_RR_TYPE_RRSIG, 536238106Sdes dclass); 537238106Sdes if(*rrset_prev && rrset_has_sigover(pkt, *rrset_prev, type, 538238106Sdes &hasother)) { 539238106Sdes /* yes! */ 540238106Sdes *prev_dname_first = (*rrset_prev)->dname; 541238106Sdes *prev_dname_last = dname; 542238106Sdes *prev_dnamelen = dnamelen; 543238106Sdes *prev_type = type; 544238106Sdes *prev_dclass = dclass; 545238106Sdes *rrset_prev = change_rrsig_rrset(*rrset_prev, msg, 546238106Sdes pkt, type, *rrset_flags, hasother, section, 547238106Sdes region); 548238106Sdes if(!*rrset_prev) return 0; 549238106Sdes return 1; 550238106Sdes } 551238106Sdes } 552238106Sdes 553238106Sdes *hash = pkt_hash_rrset_rest(dname_h, type, dclass, *rrset_flags); 554238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, *rrset_flags, 555238106Sdes dname, dnamelen, type, dclass); 556238106Sdes if(*rrset_prev) 557238106Sdes *prev_dname_first = (*rrset_prev)->dname; 558238106Sdes else *prev_dname_first = dname; 559238106Sdes *prev_dname_last = dname; 560238106Sdes *prev_dnamelen = dnamelen; 561238106Sdes *prev_type = type; 562238106Sdes *prev_dclass = dclass; 563238106Sdes return 1; 564238106Sdes} 565238106Sdes 566238106Sdes/** 567238106Sdes * Parse query section. 568238106Sdes * @param pkt: packet, position at call must be at start of query section. 569238106Sdes * at end position is after query section. 570238106Sdes * @param msg: store results here. 571238106Sdes * @return: 0 if OK, or rcode on error. 572238106Sdes */ 573238106Sdesstatic int 574269257Sdesparse_query_section(sldns_buffer* pkt, struct msg_parse* msg) 575238106Sdes{ 576238106Sdes if(msg->qdcount == 0) 577238106Sdes return 0; 578238106Sdes if(msg->qdcount > 1) 579238106Sdes return LDNS_RCODE_FORMERR; 580238106Sdes log_assert(msg->qdcount == 1); 581269257Sdes if(sldns_buffer_remaining(pkt) <= 0) 582238106Sdes return LDNS_RCODE_FORMERR; 583269257Sdes msg->qname = sldns_buffer_current(pkt); 584238106Sdes if((msg->qname_len = pkt_dname_len(pkt)) == 0) 585238106Sdes return LDNS_RCODE_FORMERR; 586269257Sdes if(sldns_buffer_remaining(pkt) < sizeof(uint16_t)*2) 587238106Sdes return LDNS_RCODE_FORMERR; 588269257Sdes msg->qtype = sldns_buffer_read_u16(pkt); 589269257Sdes msg->qclass = sldns_buffer_read_u16(pkt); 590238106Sdes return 0; 591238106Sdes} 592238106Sdes 593238106Sdessize_t 594269257Sdesget_rdf_size(sldns_rdf_type rdf) 595238106Sdes{ 596238106Sdes switch(rdf) { 597238106Sdes case LDNS_RDF_TYPE_CLASS: 598238106Sdes case LDNS_RDF_TYPE_ALG: 599238106Sdes case LDNS_RDF_TYPE_INT8: 600238106Sdes return 1; 601238106Sdes break; 602238106Sdes case LDNS_RDF_TYPE_INT16: 603238106Sdes case LDNS_RDF_TYPE_TYPE: 604238106Sdes case LDNS_RDF_TYPE_CERT_ALG: 605238106Sdes return 2; 606238106Sdes break; 607238106Sdes case LDNS_RDF_TYPE_INT32: 608238106Sdes case LDNS_RDF_TYPE_TIME: 609238106Sdes case LDNS_RDF_TYPE_A: 610238106Sdes case LDNS_RDF_TYPE_PERIOD: 611238106Sdes return 4; 612238106Sdes break; 613238106Sdes case LDNS_RDF_TYPE_TSIGTIME: 614238106Sdes return 6; 615238106Sdes break; 616238106Sdes case LDNS_RDF_TYPE_AAAA: 617238106Sdes return 16; 618238106Sdes break; 619238106Sdes default: 620269257Sdes log_assert(0); /* add type above */ 621238106Sdes /* only types that appear before a domain * 622238106Sdes * name are needed. rest is simply copied. */ 623238106Sdes } 624238106Sdes return 0; 625238106Sdes} 626238106Sdes 627238106Sdes/** calculate the size of one rr */ 628238106Sdesstatic int 629269257Sdescalc_size(sldns_buffer* pkt, uint16_t type, struct rr_parse* rr) 630238106Sdes{ 631269257Sdes const sldns_rr_descriptor* desc; 632238106Sdes uint16_t pkt_len; /* length of rr inside the packet */ 633238106Sdes rr->size = sizeof(uint16_t); /* the rdatalen */ 634269257Sdes sldns_buffer_skip(pkt, 4); /* skip ttl */ 635269257Sdes pkt_len = sldns_buffer_read_u16(pkt); 636269257Sdes if(sldns_buffer_remaining(pkt) < pkt_len) 637238106Sdes return 0; 638269257Sdes desc = sldns_rr_descript(type); 639238106Sdes if(pkt_len > 0 && desc && desc->_dname_count > 0) { 640238106Sdes int count = (int)desc->_dname_count; 641238106Sdes int rdf = 0; 642238106Sdes size_t len; 643238106Sdes size_t oldpos; 644238106Sdes /* skip first part. */ 645238106Sdes while(pkt_len > 0 && count) { 646238106Sdes switch(desc->_wireformat[rdf]) { 647238106Sdes case LDNS_RDF_TYPE_DNAME: 648238106Sdes /* decompress every domain name */ 649269257Sdes oldpos = sldns_buffer_position(pkt); 650238106Sdes if((len = pkt_dname_len(pkt)) == 0) 651238106Sdes return 0; /* malformed dname */ 652269257Sdes if(sldns_buffer_position(pkt)-oldpos > pkt_len) 653238106Sdes return 0; /* dname exceeds rdata */ 654269257Sdes pkt_len -= sldns_buffer_position(pkt)-oldpos; 655238106Sdes rr->size += len; 656238106Sdes count--; 657238106Sdes len = 0; 658238106Sdes break; 659238106Sdes case LDNS_RDF_TYPE_STR: 660249141Sdes if(pkt_len < 1) { 661249141Sdes /* NOTREACHED, due to 'while(>0)' */ 662238106Sdes return 0; /* len byte exceeds rdata */ 663249141Sdes } 664269257Sdes len = sldns_buffer_current(pkt)[0] + 1; 665238106Sdes break; 666238106Sdes default: 667238106Sdes len = get_rdf_size(desc->_wireformat[rdf]); 668238106Sdes } 669238106Sdes if(len) { 670238106Sdes if(pkt_len < len) 671238106Sdes return 0; /* exceeds rdata */ 672238106Sdes pkt_len -= len; 673269257Sdes sldns_buffer_skip(pkt, (ssize_t)len); 674238106Sdes rr->size += len; 675238106Sdes } 676238106Sdes rdf++; 677238106Sdes } 678238106Sdes } 679238106Sdes /* remaining rdata */ 680238106Sdes rr->size += pkt_len; 681269257Sdes sldns_buffer_skip(pkt, (ssize_t)pkt_len); 682238106Sdes return 1; 683238106Sdes} 684238106Sdes 685238106Sdes/** skip rr ttl and rdata */ 686238106Sdesstatic int 687269257Sdesskip_ttl_rdata(sldns_buffer* pkt) 688238106Sdes{ 689238106Sdes uint16_t rdatalen; 690269257Sdes if(sldns_buffer_remaining(pkt) < 6) /* ttl + rdatalen */ 691238106Sdes return 0; 692269257Sdes sldns_buffer_skip(pkt, 4); /* ttl */ 693269257Sdes rdatalen = sldns_buffer_read_u16(pkt); 694269257Sdes if(sldns_buffer_remaining(pkt) < rdatalen) 695238106Sdes return 0; 696269257Sdes sldns_buffer_skip(pkt, (ssize_t)rdatalen); 697238106Sdes return 1; 698238106Sdes} 699238106Sdes 700238106Sdes/** see if RRSIG is a duplicate of another */ 701238106Sdesstatic int 702269257Sdessig_is_double(sldns_buffer* pkt, struct rrset_parse* rrset, uint8_t* ttldata) 703238106Sdes{ 704238106Sdes uint16_t rlen, siglen; 705269257Sdes size_t pos = sldns_buffer_position(pkt); 706238106Sdes struct rr_parse* sig; 707269257Sdes if(sldns_buffer_remaining(pkt) < 6) 708238106Sdes return 0; 709269257Sdes sldns_buffer_skip(pkt, 4); /* ttl */ 710269257Sdes rlen = sldns_buffer_read_u16(pkt); 711269257Sdes if(sldns_buffer_remaining(pkt) < rlen) { 712269257Sdes sldns_buffer_set_position(pkt, pos); 713238106Sdes return 0; 714238106Sdes } 715269257Sdes sldns_buffer_set_position(pkt, pos); 716238106Sdes 717238106Sdes sig = rrset->rrsig_first; 718238106Sdes while(sig) { 719238106Sdes /* check if rdatalen is same */ 720238106Sdes memmove(&siglen, sig->ttl_data+4, sizeof(siglen)); 721238106Sdes siglen = ntohs(siglen); 722238106Sdes /* checks if data in packet is exactly the same, this means 723238106Sdes * also dname in rdata is the same, but rrsig is not allowed 724238106Sdes * to have compressed dnames anyway. If it is compressed anyway 725238106Sdes * it will lead to duplicate rrs for qtype=RRSIG. (or ANY). 726238106Sdes * 727238106Sdes * Cannot use sig->size because size of the other one is not 728238106Sdes * calculated yet. 729238106Sdes */ 730238106Sdes if(siglen == rlen) { 731238106Sdes if(siglen>0 && memcmp(sig->ttl_data+6, ttldata+6, 732238106Sdes siglen) == 0) { 733238106Sdes /* same! */ 734238106Sdes return 1; 735238106Sdes } 736238106Sdes } 737238106Sdes sig = sig->next; 738238106Sdes } 739238106Sdes return 0; 740238106Sdes} 741238106Sdes 742238106Sdes/** Add rr (from packet here) to rrset, skips rr */ 743238106Sdesstatic int 744269257Sdesadd_rr_to_rrset(struct rrset_parse* rrset, sldns_buffer* pkt, 745238106Sdes struct msg_parse* msg, struct regional* region, 746269257Sdes sldns_pkt_section section, uint16_t type) 747238106Sdes{ 748238106Sdes struct rr_parse* rr; 749238106Sdes /* check section of rrset. */ 750238106Sdes if(rrset->section != section && type != LDNS_RR_TYPE_RRSIG && 751238106Sdes rrset->type != LDNS_RR_TYPE_RRSIG) { 752238106Sdes /* silently drop it - we drop the last part, since 753238106Sdes * trust in rr data depends on the section it is in. 754238106Sdes * the less trustworthy part is discarded. 755238106Sdes * also the last part is more likely to be incomplete. 756238106Sdes * RFC 2181: must put RRset only once in response. */ 757238106Sdes /* 758238106Sdes verbose(VERB_QUERY, "Packet contains rrset data in " 759238106Sdes "multiple sections, dropped last part."); 760238106Sdes log_buf(VERB_QUERY, "packet was", pkt); 761238106Sdes */ 762238106Sdes /* forwards */ 763238106Sdes if(!skip_ttl_rdata(pkt)) 764238106Sdes return LDNS_RCODE_FORMERR; 765238106Sdes return 0; 766238106Sdes } 767238106Sdes 768238106Sdes if( (msg->qtype == LDNS_RR_TYPE_RRSIG || 769238106Sdes msg->qtype == LDNS_RR_TYPE_ANY) 770269257Sdes && sig_is_double(pkt, rrset, sldns_buffer_current(pkt))) { 771238106Sdes if(!skip_ttl_rdata(pkt)) 772238106Sdes return LDNS_RCODE_FORMERR; 773238106Sdes return 0; 774238106Sdes } 775238106Sdes 776238106Sdes /* create rr */ 777238106Sdes if(!(rr = (struct rr_parse*)regional_alloc(region, sizeof(*rr)))) 778238106Sdes return LDNS_RCODE_SERVFAIL; 779238106Sdes rr->outside_packet = 0; 780269257Sdes rr->ttl_data = sldns_buffer_current(pkt); 781238106Sdes rr->next = 0; 782238106Sdes if(type == LDNS_RR_TYPE_RRSIG && rrset->type != LDNS_RR_TYPE_RRSIG) { 783238106Sdes if(rrset->rrsig_last) 784238106Sdes rrset->rrsig_last->next = rr; 785238106Sdes else rrset->rrsig_first = rr; 786238106Sdes rrset->rrsig_last = rr; 787238106Sdes rrset->rrsig_count++; 788238106Sdes } else { 789238106Sdes if(rrset->rr_last) 790238106Sdes rrset->rr_last->next = rr; 791238106Sdes else rrset->rr_first = rr; 792238106Sdes rrset->rr_last = rr; 793238106Sdes rrset->rr_count++; 794238106Sdes } 795238106Sdes 796238106Sdes /* calc decompressed size */ 797238106Sdes if(!calc_size(pkt, type, rr)) 798238106Sdes return LDNS_RCODE_FORMERR; 799238106Sdes rrset->size += rr->size; 800238106Sdes 801238106Sdes return 0; 802238106Sdes} 803238106Sdes 804238106Sdes/** 805238106Sdes * Parse packet RR section, for answer, authority and additional sections. 806238106Sdes * @param pkt: packet, position at call must be at start of section. 807238106Sdes * at end position is after section. 808238106Sdes * @param msg: store results here. 809238106Sdes * @param region: how to alloc results. 810238106Sdes * @param section: section enum. 811238106Sdes * @param num_rrs: how many rrs are in the section. 812238106Sdes * @param num_rrsets: returns number of rrsets in the section. 813238106Sdes * @return: 0 if OK, or rcode on error. 814238106Sdes */ 815238106Sdesstatic int 816269257Sdesparse_section(sldns_buffer* pkt, struct msg_parse* msg, 817269257Sdes struct regional* region, sldns_pkt_section section, 818238106Sdes uint16_t num_rrs, size_t* num_rrsets) 819238106Sdes{ 820238106Sdes uint16_t i; 821238106Sdes uint8_t* dname, *prev_dname_f = NULL, *prev_dname_l = NULL; 822238106Sdes size_t dnamelen, prev_dnamelen = 0; 823238106Sdes uint16_t type, prev_type = 0; 824238106Sdes uint16_t dclass, prev_dclass = 0; 825238106Sdes uint32_t rrset_flags = 0; 826238106Sdes hashvalue_t hash = 0; 827238106Sdes struct rrset_parse* rrset = NULL; 828238106Sdes int r; 829238106Sdes 830238106Sdes if(num_rrs == 0) 831238106Sdes return 0; 832269257Sdes if(sldns_buffer_remaining(pkt) <= 0) 833238106Sdes return LDNS_RCODE_FORMERR; 834238106Sdes for(i=0; i<num_rrs; i++) { 835238106Sdes /* parse this RR. */ 836269257Sdes dname = sldns_buffer_current(pkt); 837238106Sdes if((dnamelen = pkt_dname_len(pkt)) == 0) 838238106Sdes return LDNS_RCODE_FORMERR; 839269257Sdes if(sldns_buffer_remaining(pkt) < 10) /* type, class, ttl, len */ 840238106Sdes return LDNS_RCODE_FORMERR; 841269257Sdes type = sldns_buffer_read_u16(pkt); 842269257Sdes sldns_buffer_read(pkt, &dclass, sizeof(dclass)); 843238106Sdes 844238106Sdes if(0) { /* debug show what is being parsed. */ 845238106Sdes if(type == LDNS_RR_TYPE_RRSIG) { 846238106Sdes uint16_t t; 847238106Sdes if(pkt_rrsig_covered(pkt, 848269257Sdes sldns_buffer_current(pkt), &t)) 849238106Sdes fprintf(stderr, "parse of %s(%d) [%s(%d)]", 850269257Sdes sldns_rr_descript(type)? 851269257Sdes sldns_rr_descript(type)->_name: "??", 852238106Sdes (int)type, 853269257Sdes sldns_rr_descript(t)? 854269257Sdes sldns_rr_descript(t)->_name: "??", 855238106Sdes (int)t); 856238106Sdes } else 857238106Sdes fprintf(stderr, "parse of %s(%d)", 858269257Sdes sldns_rr_descript(type)? 859269257Sdes sldns_rr_descript(type)->_name: "??", 860238106Sdes (int)type); 861238106Sdes fprintf(stderr, " %s(%d) ", 862269257Sdes sldns_lookup_by_id(sldns_rr_classes, 863269257Sdes (int)ntohs(dclass))?sldns_lookup_by_id( 864269257Sdes sldns_rr_classes, (int)ntohs(dclass))->name: 865238106Sdes "??", (int)ntohs(dclass)); 866238106Sdes dname_print(stderr, pkt, dname); 867238106Sdes fprintf(stderr, "\n"); 868238106Sdes } 869238106Sdes 870238106Sdes /* see if it is part of an existing RR set */ 871238106Sdes if(!find_rrset(msg, pkt, dname, dnamelen, type, dclass, &hash, 872238106Sdes &rrset_flags, &prev_dname_f, &prev_dname_l, 873238106Sdes &prev_dnamelen, &prev_type, &prev_dclass, &rrset, 874238106Sdes section, region)) 875238106Sdes return LDNS_RCODE_SERVFAIL; 876238106Sdes if(!rrset) { 877238106Sdes /* it is a new RR set. hash&flags already calculated.*/ 878238106Sdes (*num_rrsets)++; 879238106Sdes rrset = new_rrset(msg, dname, dnamelen, type, dclass, 880238106Sdes hash, rrset_flags, section, region); 881238106Sdes if(!rrset) 882238106Sdes return LDNS_RCODE_SERVFAIL; 883238106Sdes } 884238106Sdes else if(0) { 885238106Sdes fprintf(stderr, "is part of existing: "); 886238106Sdes dname_print(stderr, pkt, rrset->dname); 887238106Sdes fprintf(stderr, " type %s(%d)\n", 888269257Sdes sldns_rr_descript(rrset->type)? 889269257Sdes sldns_rr_descript(rrset->type)->_name: "??", 890238106Sdes (int)rrset->type); 891238106Sdes } 892238106Sdes /* add to rrset. */ 893238106Sdes if((r=add_rr_to_rrset(rrset, pkt, msg, region, section, 894238106Sdes type)) != 0) 895238106Sdes return r; 896238106Sdes } 897238106Sdes return 0; 898238106Sdes} 899238106Sdes 900238106Sdesint 901269257Sdesparse_packet(sldns_buffer* pkt, struct msg_parse* msg, struct regional* region) 902238106Sdes{ 903238106Sdes int ret; 904269257Sdes if(sldns_buffer_remaining(pkt) < LDNS_HEADER_SIZE) 905238106Sdes return LDNS_RCODE_FORMERR; 906238106Sdes /* read the header */ 907269257Sdes sldns_buffer_read(pkt, &msg->id, sizeof(uint16_t)); 908269257Sdes msg->flags = sldns_buffer_read_u16(pkt); 909269257Sdes msg->qdcount = sldns_buffer_read_u16(pkt); 910269257Sdes msg->ancount = sldns_buffer_read_u16(pkt); 911269257Sdes msg->nscount = sldns_buffer_read_u16(pkt); 912269257Sdes msg->arcount = sldns_buffer_read_u16(pkt); 913238106Sdes if(msg->qdcount > 1) 914238106Sdes return LDNS_RCODE_FORMERR; 915238106Sdes if((ret = parse_query_section(pkt, msg)) != 0) 916238106Sdes return ret; 917238106Sdes if((ret = parse_section(pkt, msg, region, LDNS_SECTION_ANSWER, 918238106Sdes msg->ancount, &msg->an_rrsets)) != 0) 919238106Sdes return ret; 920238106Sdes if((ret = parse_section(pkt, msg, region, LDNS_SECTION_AUTHORITY, 921238106Sdes msg->nscount, &msg->ns_rrsets)) != 0) 922238106Sdes return ret; 923269257Sdes if(sldns_buffer_remaining(pkt) == 0 && msg->arcount == 1) { 924238106Sdes /* BIND accepts leniently that an EDNS record is missing. 925238106Sdes * so, we do too. */ 926238106Sdes } else if((ret = parse_section(pkt, msg, region, 927238106Sdes LDNS_SECTION_ADDITIONAL, msg->arcount, &msg->ar_rrsets)) != 0) 928238106Sdes return ret; 929269257Sdes /* if(sldns_buffer_remaining(pkt) > 0) { */ 930238106Sdes /* there is spurious data at end of packet. ignore */ 931238106Sdes /* } */ 932238106Sdes msg->rrset_count = msg->an_rrsets + msg->ns_rrsets + msg->ar_rrsets; 933238106Sdes return 0; 934238106Sdes} 935238106Sdes 936238106Sdesint 937238106Sdesparse_extract_edns(struct msg_parse* msg, struct edns_data* edns) 938238106Sdes{ 939238106Sdes struct rrset_parse* rrset = msg->rrset_first; 940238106Sdes struct rrset_parse* prev = 0; 941238106Sdes struct rrset_parse* found = 0; 942238106Sdes struct rrset_parse* found_prev = 0; 943238106Sdes /* since the class encodes the UDP size, we cannot use hash table to 944238106Sdes * find the EDNS OPT record. Scan the packet. */ 945238106Sdes while(rrset) { 946238106Sdes if(rrset->type == LDNS_RR_TYPE_OPT) { 947238106Sdes /* only one OPT RR allowed. */ 948238106Sdes if(found) return LDNS_RCODE_FORMERR; 949238106Sdes /* found it! */ 950238106Sdes found_prev = prev; 951238106Sdes found = rrset; 952238106Sdes } 953238106Sdes prev = rrset; 954238106Sdes rrset = rrset->rrset_all_next; 955238106Sdes } 956238106Sdes if(!found) { 957238106Sdes memset(edns, 0, sizeof(*edns)); 958238106Sdes edns->udp_size = 512; 959238106Sdes return 0; 960238106Sdes } 961238106Sdes /* check the found RRset */ 962238106Sdes /* most lenient check possible. ignore dname, use last opt */ 963238106Sdes if(found->section != LDNS_SECTION_ADDITIONAL) 964238106Sdes return LDNS_RCODE_FORMERR; 965238106Sdes if(found->rr_count == 0) 966238106Sdes return LDNS_RCODE_FORMERR; 967238106Sdes if(0) { /* strict checking of dname and RRcount */ 968238106Sdes if(found->dname_len != 1 || !found->dname 969238106Sdes || found->dname[0] != 0) return LDNS_RCODE_FORMERR; 970238106Sdes if(found->rr_count != 1) return LDNS_RCODE_FORMERR; 971238106Sdes } 972238106Sdes log_assert(found->rr_first && found->rr_last); 973238106Sdes 974238106Sdes /* remove from packet */ 975238106Sdes if(found_prev) found_prev->rrset_all_next = found->rrset_all_next; 976238106Sdes else msg->rrset_first = found->rrset_all_next; 977238106Sdes if(found == msg->rrset_last) 978238106Sdes msg->rrset_last = found_prev; 979238106Sdes msg->arcount --; 980238106Sdes msg->ar_rrsets --; 981238106Sdes msg->rrset_count --; 982238106Sdes 983238106Sdes /* take the data ! */ 984238106Sdes edns->edns_present = 1; 985238106Sdes edns->ext_rcode = found->rr_last->ttl_data[0]; 986238106Sdes edns->edns_version = found->rr_last->ttl_data[1]; 987269257Sdes edns->bits = sldns_read_uint16(&found->rr_last->ttl_data[2]); 988238106Sdes edns->udp_size = ntohs(found->rrset_class); 989238106Sdes /* ignore rdata and rrsigs */ 990238106Sdes return 0; 991238106Sdes} 992238106Sdes 993238106Sdesint 994269257Sdesparse_edns_from_pkt(sldns_buffer* pkt, struct edns_data* edns) 995238106Sdes{ 996269257Sdes log_assert(LDNS_QDCOUNT(sldns_buffer_begin(pkt)) == 1); 997269257Sdes log_assert(LDNS_ANCOUNT(sldns_buffer_begin(pkt)) == 0); 998269257Sdes log_assert(LDNS_NSCOUNT(sldns_buffer_begin(pkt)) == 0); 999238106Sdes /* check edns section is present */ 1000269257Sdes if(LDNS_ARCOUNT(sldns_buffer_begin(pkt)) > 1) { 1001238106Sdes return LDNS_RCODE_FORMERR; 1002238106Sdes } 1003269257Sdes if(LDNS_ARCOUNT(sldns_buffer_begin(pkt)) == 0) { 1004238106Sdes memset(edns, 0, sizeof(*edns)); 1005238106Sdes edns->udp_size = 512; 1006238106Sdes return 0; 1007238106Sdes } 1008238106Sdes /* domain name must be the root of length 1. */ 1009238106Sdes if(pkt_dname_len(pkt) != 1) 1010238106Sdes return LDNS_RCODE_FORMERR; 1011269257Sdes if(sldns_buffer_remaining(pkt) < 10) /* type, class, ttl, rdatalen */ 1012238106Sdes return LDNS_RCODE_FORMERR; 1013269257Sdes if(sldns_buffer_read_u16(pkt) != LDNS_RR_TYPE_OPT) 1014238106Sdes return LDNS_RCODE_FORMERR; 1015238106Sdes edns->edns_present = 1; 1016269257Sdes edns->udp_size = sldns_buffer_read_u16(pkt); /* class is udp size */ 1017269257Sdes edns->ext_rcode = sldns_buffer_read_u8(pkt); /* ttl used for bits */ 1018269257Sdes edns->edns_version = sldns_buffer_read_u8(pkt); 1019269257Sdes edns->bits = sldns_buffer_read_u16(pkt); 1020238106Sdes /* ignore rdata and rrsigs */ 1021238106Sdes return 0; 1022238106Sdes} 1023