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 24266114Sdes * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25266114Sdes * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 26266114Sdes * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 27266114Sdes * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28266114Sdes * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 29266114Sdes * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 30266114Sdes * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 31266114Sdes * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 32266114Sdes * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33266114Sdes * 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" 41307729Sdes#include "util/data/msgreply.h" 42238106Sdes#include "util/data/dname.h" 43238106Sdes#include "util/data/packed_rrset.h" 44238106Sdes#include "util/storage/lookup3.h" 45238106Sdes#include "util/regional.h" 46287917Sdes#include "sldns/rrdef.h" 47287917Sdes#include "sldns/sbuffer.h" 48287917Sdes#include "sldns/parseutil.h" 49287917Sdes#include "sldns/wire2str.h" 50238106Sdes 51238106Sdes/** smart comparison of (compressed, valid) dnames from packet */ 52238106Sdesstatic int 53266114Sdessmart_compare(sldns_buffer* pkt, uint8_t* dnow, 54238106Sdes uint8_t* dprfirst, uint8_t* dprlast) 55238106Sdes{ 56238106Sdes if(LABEL_IS_PTR(*dnow)) { 57238106Sdes /* ptr points to a previous dname */ 58361435Scy uint8_t* p; 59361435Scy if((size_t)PTR_OFFSET(dnow[0], dnow[1]) 60361435Scy >= sldns_buffer_limit(pkt)) 61361435Scy return -1; 62361435Scy p = sldns_buffer_at(pkt, PTR_OFFSET(dnow[0], dnow[1])); 63238106Sdes if( p == dprfirst || p == dprlast ) 64238106Sdes return 0; 65238106Sdes /* prev dname is also a ptr, both ptrs are the same. */ 66238106Sdes if(LABEL_IS_PTR(*dprlast) && 67238106Sdes dprlast[0] == dnow[0] && dprlast[1] == dnow[1]) 68238106Sdes return 0; 69238106Sdes } 70238106Sdes return dname_pkt_compare(pkt, dnow, dprlast); 71238106Sdes} 72238106Sdes 73238106Sdes/** 74238106Sdes * Allocate new rrset in region, fill with data. 75238106Sdes */ 76238106Sdesstatic struct rrset_parse* 77238106Sdesnew_rrset(struct msg_parse* msg, uint8_t* dname, size_t dnamelen, 78356345Scy uint16_t type, uint16_t dclass, hashvalue_type hash, 79266114Sdes uint32_t rrset_flags, sldns_pkt_section section, 80238106Sdes struct regional* region) 81238106Sdes{ 82238106Sdes struct rrset_parse* p = regional_alloc(region, sizeof(*p)); 83238106Sdes if(!p) return NULL; 84238106Sdes p->rrset_bucket_next = msg->hashtable[hash & (PARSE_TABLE_SIZE-1)]; 85238106Sdes msg->hashtable[hash & (PARSE_TABLE_SIZE-1)] = p; 86238106Sdes p->rrset_all_next = 0; 87238106Sdes if(msg->rrset_last) 88238106Sdes msg->rrset_last->rrset_all_next = p; 89238106Sdes else msg->rrset_first = p; 90238106Sdes msg->rrset_last = p; 91238106Sdes p->hash = hash; 92238106Sdes p->section = section; 93238106Sdes p->dname = dname; 94238106Sdes p->dname_len = dnamelen; 95238106Sdes p->type = type; 96238106Sdes p->rrset_class = dclass; 97238106Sdes p->flags = rrset_flags; 98238106Sdes p->rr_count = 0; 99238106Sdes p->size = 0; 100238106Sdes p->rr_first = 0; 101238106Sdes p->rr_last = 0; 102238106Sdes p->rrsig_count = 0; 103238106Sdes p->rrsig_first = 0; 104238106Sdes p->rrsig_last = 0; 105238106Sdes return p; 106238106Sdes} 107238106Sdes 108238106Sdes/** See if next rrset is nsec at zone apex */ 109238106Sdesstatic int 110266114Sdesnsec_at_apex(sldns_buffer* pkt) 111238106Sdes{ 112238106Sdes /* we are at ttl position in packet. */ 113266114Sdes size_t pos = sldns_buffer_position(pkt); 114238106Sdes uint16_t rdatalen; 115266114Sdes if(sldns_buffer_remaining(pkt) < 7) /* ttl+len+root */ 116238106Sdes return 0; /* eek! */ 117266114Sdes sldns_buffer_skip(pkt, 4); /* ttl */; 118266114Sdes rdatalen = sldns_buffer_read_u16(pkt); 119266114Sdes if(sldns_buffer_remaining(pkt) < rdatalen) { 120266114Sdes sldns_buffer_set_position(pkt, pos); 121238106Sdes return 0; /* parse error happens later */ 122238106Sdes } 123238106Sdes /* must validate the nsec next domain name format */ 124238106Sdes if(pkt_dname_len(pkt) == 0) { 125266114Sdes sldns_buffer_set_position(pkt, pos); 126238106Sdes return 0; /* parse error */ 127238106Sdes } 128238106Sdes 129238106Sdes /* see if SOA bit is set. */ 130266114Sdes if(sldns_buffer_position(pkt) < pos+4+rdatalen) { 131238106Sdes /* nsec type bitmap contains items */ 132238106Sdes uint8_t win, blen, bits; 133238106Sdes /* need: windownum, bitmap len, firstbyte */ 134266114Sdes if(sldns_buffer_position(pkt)+3 > pos+4+rdatalen) { 135266114Sdes sldns_buffer_set_position(pkt, pos); 136238106Sdes return 0; /* malformed nsec */ 137238106Sdes } 138266114Sdes win = sldns_buffer_read_u8(pkt); 139266114Sdes blen = sldns_buffer_read_u8(pkt); 140266114Sdes bits = sldns_buffer_read_u8(pkt); 141238106Sdes /* 0window always first window. bitlen >=1 or parse 142238106Sdes error really. bit 0x2 is SOA. */ 143238106Sdes if(win == 0 && blen >= 1 && (bits & 0x02)) { 144266114Sdes sldns_buffer_set_position(pkt, pos); 145238106Sdes return 1; 146238106Sdes } 147238106Sdes } 148238106Sdes 149266114Sdes sldns_buffer_set_position(pkt, pos); 150238106Sdes return 0; 151238106Sdes} 152238106Sdes 153238106Sdes/** Calculate rrset flags */ 154238106Sdesstatic uint32_t 155266114Sdespkt_rrset_flags(sldns_buffer* pkt, uint16_t type, sldns_pkt_section sec) 156238106Sdes{ 157238106Sdes uint32_t f = 0; 158238106Sdes if(type == LDNS_RR_TYPE_NSEC && nsec_at_apex(pkt)) { 159238106Sdes f |= PACKED_RRSET_NSEC_AT_APEX; 160238106Sdes } else if(type == LDNS_RR_TYPE_SOA && sec == LDNS_SECTION_AUTHORITY) { 161238106Sdes f |= PACKED_RRSET_SOA_NEG; 162238106Sdes } 163238106Sdes return f; 164238106Sdes} 165238106Sdes 166356345Scyhashvalue_type 167266114Sdespkt_hash_rrset(sldns_buffer* pkt, uint8_t* dname, uint16_t type, 168238106Sdes uint16_t dclass, uint32_t rrset_flags) 169238106Sdes{ 170238106Sdes /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ 171238106Sdes /* this routine handles compressed names */ 172356345Scy hashvalue_type h = 0xab; 173238106Sdes h = dname_pkt_hash(pkt, dname, h); 174238106Sdes h = hashlittle(&type, sizeof(type), h); /* host order */ 175238106Sdes h = hashlittle(&dclass, sizeof(dclass), h); /* netw order */ 176238106Sdes h = hashlittle(&rrset_flags, sizeof(uint32_t), h); 177238106Sdes return h; 178238106Sdes} 179238106Sdes 180238106Sdes/** create partial dname hash for rrset hash */ 181356345Scystatic hashvalue_type 182266114Sdespkt_hash_rrset_first(sldns_buffer* pkt, uint8_t* dname) 183238106Sdes{ 184238106Sdes /* works together with pkt_hash_rrset_rest */ 185238106Sdes /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ 186238106Sdes /* this routine handles compressed names */ 187356345Scy hashvalue_type h = 0xab; 188238106Sdes h = dname_pkt_hash(pkt, dname, h); 189238106Sdes return h; 190238106Sdes} 191238106Sdes 192238106Sdes/** create a rrset hash from a partial dname hash */ 193356345Scystatic hashvalue_type 194356345Scypkt_hash_rrset_rest(hashvalue_type dname_h, uint16_t type, uint16_t dclass, 195238106Sdes uint32_t rrset_flags) 196238106Sdes{ 197238106Sdes /* works together with pkt_hash_rrset_first */ 198238106Sdes /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ 199356345Scy hashvalue_type h; 200238106Sdes h = hashlittle(&type, sizeof(type), dname_h); /* host order */ 201238106Sdes h = hashlittle(&dclass, sizeof(dclass), h); /* netw order */ 202238106Sdes h = hashlittle(&rrset_flags, sizeof(uint32_t), h); 203238106Sdes return h; 204238106Sdes} 205238106Sdes 206238106Sdes/** compare rrset_parse with data */ 207238106Sdesstatic int 208356345Scyrrset_parse_equals(struct rrset_parse* p, sldns_buffer* pkt, hashvalue_type h, 209238106Sdes uint32_t rrset_flags, uint8_t* dname, size_t dnamelen, 210238106Sdes uint16_t type, uint16_t dclass) 211238106Sdes{ 212238106Sdes if(p->hash == h && p->dname_len == dnamelen && p->type == type && 213238106Sdes p->rrset_class == dclass && p->flags == rrset_flags && 214238106Sdes dname_pkt_compare(pkt, dname, p->dname) == 0) 215238106Sdes return 1; 216238106Sdes return 0; 217238106Sdes} 218238106Sdes 219238106Sdes 220238106Sdesstruct rrset_parse* 221266114Sdesmsgparse_hashtable_lookup(struct msg_parse* msg, sldns_buffer* pkt, 222356345Scy hashvalue_type h, uint32_t rrset_flags, uint8_t* dname, 223356345Scy size_t dnamelen, uint16_t type, uint16_t dclass) 224238106Sdes{ 225238106Sdes struct rrset_parse* p = msg->hashtable[h & (PARSE_TABLE_SIZE-1)]; 226238106Sdes while(p) { 227238106Sdes if(rrset_parse_equals(p, pkt, h, rrset_flags, dname, dnamelen, 228238106Sdes type, dclass)) 229238106Sdes return p; 230238106Sdes p = p->rrset_bucket_next; 231238106Sdes } 232238106Sdes return NULL; 233238106Sdes} 234238106Sdes 235238106Sdes/** return type networkformat that rrsig in packet covers */ 236238106Sdesstatic int 237266114Sdespkt_rrsig_covered(sldns_buffer* pkt, uint8_t* here, uint16_t* type) 238238106Sdes{ 239266114Sdes size_t pos = sldns_buffer_position(pkt); 240266114Sdes sldns_buffer_set_position(pkt, (size_t)(here-sldns_buffer_begin(pkt))); 241238106Sdes /* ttl + len + size of small rrsig(rootlabel, no signature) */ 242266114Sdes if(sldns_buffer_remaining(pkt) < 4+2+19) 243238106Sdes return 0; 244266114Sdes sldns_buffer_skip(pkt, 4); /* ttl */ 245266114Sdes if(sldns_buffer_read_u16(pkt) < 19) /* too short */ { 246266114Sdes sldns_buffer_set_position(pkt, pos); 247238106Sdes return 0; 248238106Sdes } 249266114Sdes *type = sldns_buffer_read_u16(pkt); 250266114Sdes sldns_buffer_set_position(pkt, pos); 251238106Sdes return 1; 252238106Sdes} 253238106Sdes 254238106Sdes/** true if covered type equals prevtype */ 255238106Sdesstatic int 256266114Sdespkt_rrsig_covered_equals(sldns_buffer* pkt, uint8_t* here, uint16_t type) 257238106Sdes{ 258238106Sdes uint16_t t; 259238106Sdes if(pkt_rrsig_covered(pkt, here, &t) && t == type) 260238106Sdes return 1; 261238106Sdes return 0; 262238106Sdes} 263238106Sdes 264238106Sdesvoid 265238106Sdesmsgparse_bucket_remove(struct msg_parse* msg, struct rrset_parse* rrset) 266238106Sdes{ 267238106Sdes struct rrset_parse** p; 268238106Sdes p = &msg->hashtable[ rrset->hash & (PARSE_TABLE_SIZE-1) ]; 269238106Sdes while(*p) { 270238106Sdes if(*p == rrset) { 271238106Sdes *p = rrset->rrset_bucket_next; 272238106Sdes return; 273238106Sdes } 274238106Sdes p = &( (*p)->rrset_bucket_next ); 275238106Sdes } 276238106Sdes} 277238106Sdes 278238106Sdes/** change section of rrset from previous to current section */ 279238106Sdesstatic void 280238106Sdeschange_section(struct msg_parse* msg, struct rrset_parse* rrset, 281266114Sdes sldns_pkt_section section) 282238106Sdes{ 283238106Sdes struct rrset_parse *p, *prev; 284238106Sdes /* remove from list */ 285238106Sdes if(section == rrset->section) 286238106Sdes return; 287238106Sdes p = msg->rrset_first; 288238106Sdes prev = 0; 289238106Sdes while(p) { 290238106Sdes if(p == rrset) { 291238106Sdes if(prev) prev->rrset_all_next = p->rrset_all_next; 292238106Sdes else msg->rrset_first = p->rrset_all_next; 293238106Sdes if(msg->rrset_last == rrset) 294238106Sdes msg->rrset_last = prev; 295238106Sdes break; 296238106Sdes } 297238106Sdes prev = p; 298238106Sdes p = p->rrset_all_next; 299238106Sdes } 300238106Sdes /* remove from count */ 301238106Sdes switch(rrset->section) { 302238106Sdes case LDNS_SECTION_ANSWER: msg->an_rrsets--; break; 303238106Sdes case LDNS_SECTION_AUTHORITY: msg->ns_rrsets--; break; 304238106Sdes case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets--; break; 305238106Sdes default: log_assert(0); 306238106Sdes } 307238106Sdes /* insert at end of list */ 308238106Sdes rrset->rrset_all_next = 0; 309238106Sdes if(msg->rrset_last) 310238106Sdes msg->rrset_last->rrset_all_next = rrset; 311238106Sdes else msg->rrset_first = rrset; 312238106Sdes msg->rrset_last = rrset; 313238106Sdes /* up count of new section */ 314238106Sdes switch(section) { 315238106Sdes case LDNS_SECTION_AUTHORITY: msg->ns_rrsets++; break; 316238106Sdes case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets++; break; 317238106Sdes default: log_assert(0); 318238106Sdes } 319238106Sdes rrset->section = section; 320238106Sdes} 321238106Sdes 322238106Sdes/** see if rrset of type RRSIG contains sig over given type */ 323238106Sdesstatic int 324266114Sdesrrset_has_sigover(sldns_buffer* pkt, struct rrset_parse* rrset, uint16_t type, 325238106Sdes int* hasother) 326238106Sdes{ 327238106Sdes int res = 0; 328238106Sdes struct rr_parse* rr = rrset->rr_first; 329238106Sdes log_assert( rrset->type == LDNS_RR_TYPE_RRSIG ); 330238106Sdes while(rr) { 331238106Sdes if(pkt_rrsig_covered_equals(pkt, rr->ttl_data, type)) 332238106Sdes res = 1; 333238106Sdes else *hasother = 1; 334238106Sdes rr = rr->next; 335238106Sdes } 336238106Sdes return res; 337238106Sdes} 338238106Sdes 339238106Sdes/** move rrsigs from sigset to dataset */ 340238106Sdesstatic int 341266114Sdesmoveover_rrsigs(sldns_buffer* pkt, struct regional* region, 342238106Sdes struct rrset_parse* sigset, struct rrset_parse* dataset, int duplicate) 343238106Sdes{ 344238106Sdes struct rr_parse* sig = sigset->rr_first; 345238106Sdes struct rr_parse* prev = NULL; 346238106Sdes struct rr_parse* insert; 347238106Sdes struct rr_parse* nextsig; 348238106Sdes while(sig) { 349238106Sdes nextsig = sig->next; 350238106Sdes if(pkt_rrsig_covered_equals(pkt, sig->ttl_data, 351238106Sdes dataset->type)) { 352238106Sdes if(duplicate) { 353238106Sdes /* new */ 354238106Sdes insert = (struct rr_parse*)regional_alloc( 355238106Sdes region, sizeof(struct rr_parse)); 356238106Sdes if(!insert) return 0; 357238106Sdes insert->outside_packet = 0; 358238106Sdes insert->ttl_data = sig->ttl_data; 359238106Sdes insert->size = sig->size; 360238106Sdes /* prev not used */ 361238106Sdes } else { 362238106Sdes /* remove from sigset */ 363238106Sdes if(prev) prev->next = sig->next; 364238106Sdes else sigset->rr_first = sig->next; 365238106Sdes if(sigset->rr_last == sig) 366238106Sdes sigset->rr_last = prev; 367238106Sdes sigset->rr_count--; 368238106Sdes sigset->size -= sig->size; 369238106Sdes insert = sig; 370238106Sdes /* prev not changed */ 371238106Sdes } 372238106Sdes /* add to dataset */ 373238106Sdes dataset->rrsig_count++; 374238106Sdes insert->next = 0; 375238106Sdes if(dataset->rrsig_last) 376238106Sdes dataset->rrsig_last->next = insert; 377238106Sdes else dataset->rrsig_first = insert; 378238106Sdes dataset->rrsig_last = insert; 379238106Sdes dataset->size += insert->size; 380238106Sdes } else { 381238106Sdes prev = sig; 382238106Sdes } 383238106Sdes sig = nextsig; 384238106Sdes } 385238106Sdes return 1; 386238106Sdes} 387238106Sdes 388238106Sdes/** change an rrsig rrset for use as data rrset */ 389238106Sdesstatic struct rrset_parse* 390238106Sdeschange_rrsig_rrset(struct rrset_parse* sigset, struct msg_parse* msg, 391266114Sdes sldns_buffer* pkt, uint16_t datatype, uint32_t rrset_flags, 392266114Sdes int hasother, sldns_pkt_section section, struct regional* region) 393238106Sdes{ 394238106Sdes struct rrset_parse* dataset = sigset; 395356345Scy hashvalue_type hash = pkt_hash_rrset(pkt, sigset->dname, datatype, 396238106Sdes sigset->rrset_class, rrset_flags); 397238106Sdes log_assert( sigset->type == LDNS_RR_TYPE_RRSIG ); 398238106Sdes log_assert( datatype != LDNS_RR_TYPE_RRSIG ); 399238106Sdes if(hasother) { 400238106Sdes /* need to make new rrset to hold data type */ 401238106Sdes dataset = new_rrset(msg, sigset->dname, sigset->dname_len, 402238106Sdes datatype, sigset->rrset_class, hash, rrset_flags, 403238106Sdes section, region); 404238106Sdes if(!dataset) 405238106Sdes return NULL; 406238106Sdes switch(section) { 407238106Sdes case LDNS_SECTION_ANSWER: msg->an_rrsets++; break; 408238106Sdes case LDNS_SECTION_AUTHORITY: msg->ns_rrsets++; break; 409238106Sdes case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets++; break; 410238106Sdes default: log_assert(0); 411238106Sdes } 412238106Sdes if(!moveover_rrsigs(pkt, region, sigset, dataset, 413238106Sdes msg->qtype == LDNS_RR_TYPE_RRSIG || 414238106Sdes (msg->qtype == LDNS_RR_TYPE_ANY && 415238106Sdes section != LDNS_SECTION_ANSWER) )) 416238106Sdes return NULL; 417238106Sdes return dataset; 418238106Sdes } 419238106Sdes /* changeover the type of the rrset to data set */ 420238106Sdes msgparse_bucket_remove(msg, dataset); 421238106Sdes /* insert into new hash bucket */ 422238106Sdes dataset->rrset_bucket_next = msg->hashtable[hash&(PARSE_TABLE_SIZE-1)]; 423238106Sdes msg->hashtable[hash&(PARSE_TABLE_SIZE-1)] = dataset; 424238106Sdes dataset->hash = hash; 425238106Sdes /* use section of data item for result */ 426238106Sdes change_section(msg, dataset, section); 427238106Sdes dataset->type = datatype; 428238106Sdes dataset->flags = rrset_flags; 429238106Sdes dataset->rrsig_count += dataset->rr_count; 430238106Sdes dataset->rr_count = 0; 431238106Sdes /* move sigs to end of siglist */ 432238106Sdes if(dataset->rrsig_last) 433238106Sdes dataset->rrsig_last->next = dataset->rr_first; 434238106Sdes else dataset->rrsig_first = dataset->rr_first; 435238106Sdes dataset->rrsig_last = dataset->rr_last; 436238106Sdes dataset->rr_first = 0; 437238106Sdes dataset->rr_last = 0; 438238106Sdes return dataset; 439238106Sdes} 440238106Sdes 441238106Sdes/** Find rrset. If equal to previous it is fast. hash if not so. 442238106Sdes * @param msg: the message with hash table. 443238106Sdes * @param pkt: the packet in wireformat (needed for compression ptrs). 444238106Sdes * @param dname: pointer to start of dname (compressed) in packet. 445238106Sdes * @param dnamelen: uncompressed wirefmt length of dname. 446238106Sdes * @param type: type of current rr. 447238106Sdes * @param dclass: class of current rr. 448238106Sdes * @param hash: hash value is returned if the rrset could not be found. 449238106Sdes * @param rrset_flags: is returned if the rrset could not be found. 450238106Sdes * @param prev_dname_first: dname of last seen RR. First seen dname. 451238106Sdes * @param prev_dname_last: dname of last seen RR. Last seen dname. 452238106Sdes * @param prev_dnamelen: dname len of last seen RR. 453238106Sdes * @param prev_type: type of last seen RR. 454238106Sdes * @param prev_dclass: class of last seen RR. 455238106Sdes * @param rrset_prev: last seen RRset. 456238106Sdes * @param section: the current section in the packet. 457238106Sdes * @param region: used to allocate temporary parsing data. 458238106Sdes * @return 0 on out of memory. 459238106Sdes */ 460238106Sdesstatic int 461266114Sdesfind_rrset(struct msg_parse* msg, sldns_buffer* pkt, uint8_t* dname, 462356345Scy size_t dnamelen, uint16_t type, uint16_t dclass, hashvalue_type* hash, 463238106Sdes uint32_t* rrset_flags, 464238106Sdes uint8_t** prev_dname_first, uint8_t** prev_dname_last, 465238106Sdes size_t* prev_dnamelen, uint16_t* prev_type, 466238106Sdes uint16_t* prev_dclass, struct rrset_parse** rrset_prev, 467266114Sdes sldns_pkt_section section, struct regional* region) 468238106Sdes{ 469356345Scy hashvalue_type dname_h = pkt_hash_rrset_first(pkt, dname); 470238106Sdes uint16_t covtype; 471238106Sdes if(*rrset_prev) { 472238106Sdes /* check if equal to previous item */ 473238106Sdes if(type == *prev_type && dclass == *prev_dclass && 474238106Sdes dnamelen == *prev_dnamelen && 475238106Sdes smart_compare(pkt, dname, *prev_dname_first, 476238106Sdes *prev_dname_last) == 0 && 477238106Sdes type != LDNS_RR_TYPE_RRSIG) { 478238106Sdes /* same as previous */ 479238106Sdes *prev_dname_last = dname; 480238106Sdes return 1; 481238106Sdes } 482238106Sdes /* check if rrsig over previous item */ 483238106Sdes if(type == LDNS_RR_TYPE_RRSIG && dclass == *prev_dclass && 484266114Sdes pkt_rrsig_covered_equals(pkt, sldns_buffer_current(pkt), 485238106Sdes *prev_type) && 486238106Sdes smart_compare(pkt, dname, *prev_dname_first, 487238106Sdes *prev_dname_last) == 0) { 488238106Sdes /* covers previous */ 489238106Sdes *prev_dname_last = dname; 490238106Sdes return 1; 491238106Sdes } 492238106Sdes } 493238106Sdes /* find by hashing and lookup in hashtable */ 494238106Sdes *rrset_flags = pkt_rrset_flags(pkt, type, section); 495238106Sdes 496238106Sdes /* if rrsig - try to lookup matching data set first */ 497238106Sdes if(type == LDNS_RR_TYPE_RRSIG && pkt_rrsig_covered(pkt, 498266114Sdes sldns_buffer_current(pkt), &covtype)) { 499238106Sdes *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, 500238106Sdes *rrset_flags); 501238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, 502238106Sdes *rrset_flags, dname, dnamelen, covtype, dclass); 503238106Sdes if(!*rrset_prev && covtype == LDNS_RR_TYPE_NSEC) { 504238106Sdes /* if NSEC try with NSEC apex bit twiddled */ 505238106Sdes *rrset_flags ^= PACKED_RRSET_NSEC_AT_APEX; 506238106Sdes *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, 507238106Sdes *rrset_flags); 508238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, 509238106Sdes *hash, *rrset_flags, dname, dnamelen, covtype, 510238106Sdes dclass); 511238106Sdes if(!*rrset_prev) /* untwiddle if not found */ 512238106Sdes *rrset_flags ^= PACKED_RRSET_NSEC_AT_APEX; 513238106Sdes } 514238106Sdes if(!*rrset_prev && covtype == LDNS_RR_TYPE_SOA) { 515238106Sdes /* if SOA try with SOA neg flag twiddled */ 516238106Sdes *rrset_flags ^= PACKED_RRSET_SOA_NEG; 517238106Sdes *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, 518238106Sdes *rrset_flags); 519238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, 520238106Sdes *hash, *rrset_flags, dname, dnamelen, covtype, 521238106Sdes dclass); 522238106Sdes if(!*rrset_prev) /* untwiddle if not found */ 523238106Sdes *rrset_flags ^= PACKED_RRSET_SOA_NEG; 524238106Sdes } 525238106Sdes if(*rrset_prev) { 526238106Sdes *prev_dname_first = (*rrset_prev)->dname; 527238106Sdes *prev_dname_last = dname; 528238106Sdes *prev_dnamelen = dnamelen; 529238106Sdes *prev_type = covtype; 530238106Sdes *prev_dclass = dclass; 531238106Sdes return 1; 532238106Sdes } 533238106Sdes } 534238106Sdes if(type != LDNS_RR_TYPE_RRSIG) { 535238106Sdes int hasother = 0; 536238106Sdes /* find matching rrsig */ 537238106Sdes *hash = pkt_hash_rrset_rest(dname_h, LDNS_RR_TYPE_RRSIG, 538238106Sdes dclass, 0); 539238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, 540238106Sdes 0, dname, dnamelen, LDNS_RR_TYPE_RRSIG, 541238106Sdes dclass); 542238106Sdes if(*rrset_prev && rrset_has_sigover(pkt, *rrset_prev, type, 543238106Sdes &hasother)) { 544238106Sdes /* yes! */ 545238106Sdes *prev_dname_first = (*rrset_prev)->dname; 546238106Sdes *prev_dname_last = dname; 547238106Sdes *prev_dnamelen = dnamelen; 548238106Sdes *prev_type = type; 549238106Sdes *prev_dclass = dclass; 550238106Sdes *rrset_prev = change_rrsig_rrset(*rrset_prev, msg, 551238106Sdes pkt, type, *rrset_flags, hasother, section, 552238106Sdes region); 553238106Sdes if(!*rrset_prev) return 0; 554238106Sdes return 1; 555238106Sdes } 556238106Sdes } 557238106Sdes 558238106Sdes *hash = pkt_hash_rrset_rest(dname_h, type, dclass, *rrset_flags); 559238106Sdes *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, *rrset_flags, 560238106Sdes dname, dnamelen, type, dclass); 561238106Sdes if(*rrset_prev) 562238106Sdes *prev_dname_first = (*rrset_prev)->dname; 563238106Sdes else *prev_dname_first = dname; 564238106Sdes *prev_dname_last = dname; 565238106Sdes *prev_dnamelen = dnamelen; 566238106Sdes *prev_type = type; 567238106Sdes *prev_dclass = dclass; 568238106Sdes return 1; 569238106Sdes} 570238106Sdes 571238106Sdes/** 572238106Sdes * Parse query section. 573238106Sdes * @param pkt: packet, position at call must be at start of query section. 574238106Sdes * at end position is after query section. 575238106Sdes * @param msg: store results here. 576238106Sdes * @return: 0 if OK, or rcode on error. 577238106Sdes */ 578238106Sdesstatic int 579266114Sdesparse_query_section(sldns_buffer* pkt, struct msg_parse* msg) 580238106Sdes{ 581238106Sdes if(msg->qdcount == 0) 582238106Sdes return 0; 583238106Sdes if(msg->qdcount > 1) 584238106Sdes return LDNS_RCODE_FORMERR; 585238106Sdes log_assert(msg->qdcount == 1); 586266114Sdes if(sldns_buffer_remaining(pkt) <= 0) 587238106Sdes return LDNS_RCODE_FORMERR; 588266114Sdes msg->qname = sldns_buffer_current(pkt); 589238106Sdes if((msg->qname_len = pkt_dname_len(pkt)) == 0) 590238106Sdes return LDNS_RCODE_FORMERR; 591266114Sdes if(sldns_buffer_remaining(pkt) < sizeof(uint16_t)*2) 592238106Sdes return LDNS_RCODE_FORMERR; 593266114Sdes msg->qtype = sldns_buffer_read_u16(pkt); 594266114Sdes msg->qclass = sldns_buffer_read_u16(pkt); 595238106Sdes return 0; 596238106Sdes} 597238106Sdes 598238106Sdessize_t 599266114Sdesget_rdf_size(sldns_rdf_type rdf) 600238106Sdes{ 601238106Sdes switch(rdf) { 602238106Sdes case LDNS_RDF_TYPE_CLASS: 603238106Sdes case LDNS_RDF_TYPE_ALG: 604238106Sdes case LDNS_RDF_TYPE_INT8: 605238106Sdes return 1; 606238106Sdes break; 607238106Sdes case LDNS_RDF_TYPE_INT16: 608238106Sdes case LDNS_RDF_TYPE_TYPE: 609238106Sdes case LDNS_RDF_TYPE_CERT_ALG: 610238106Sdes return 2; 611238106Sdes break; 612238106Sdes case LDNS_RDF_TYPE_INT32: 613238106Sdes case LDNS_RDF_TYPE_TIME: 614238106Sdes case LDNS_RDF_TYPE_A: 615238106Sdes case LDNS_RDF_TYPE_PERIOD: 616238106Sdes return 4; 617238106Sdes break; 618238106Sdes case LDNS_RDF_TYPE_TSIGTIME: 619238106Sdes return 6; 620238106Sdes break; 621238106Sdes case LDNS_RDF_TYPE_AAAA: 622238106Sdes return 16; 623238106Sdes break; 624238106Sdes default: 625266114Sdes log_assert(0); /* add type above */ 626238106Sdes /* only types that appear before a domain * 627238106Sdes * name are needed. rest is simply copied. */ 628238106Sdes } 629238106Sdes return 0; 630238106Sdes} 631238106Sdes 632238106Sdes/** calculate the size of one rr */ 633238106Sdesstatic int 634266114Sdescalc_size(sldns_buffer* pkt, uint16_t type, struct rr_parse* rr) 635238106Sdes{ 636266114Sdes const sldns_rr_descriptor* desc; 637238106Sdes uint16_t pkt_len; /* length of rr inside the packet */ 638238106Sdes rr->size = sizeof(uint16_t); /* the rdatalen */ 639266114Sdes sldns_buffer_skip(pkt, 4); /* skip ttl */ 640266114Sdes pkt_len = sldns_buffer_read_u16(pkt); 641266114Sdes if(sldns_buffer_remaining(pkt) < pkt_len) 642238106Sdes return 0; 643266114Sdes desc = sldns_rr_descript(type); 644238106Sdes if(pkt_len > 0 && desc && desc->_dname_count > 0) { 645238106Sdes int count = (int)desc->_dname_count; 646238106Sdes int rdf = 0; 647238106Sdes size_t len; 648238106Sdes size_t oldpos; 649238106Sdes /* skip first part. */ 650238106Sdes while(pkt_len > 0 && count) { 651238106Sdes switch(desc->_wireformat[rdf]) { 652238106Sdes case LDNS_RDF_TYPE_DNAME: 653238106Sdes /* decompress every domain name */ 654266114Sdes oldpos = sldns_buffer_position(pkt); 655238106Sdes if((len = pkt_dname_len(pkt)) == 0) 656238106Sdes return 0; /* malformed dname */ 657266114Sdes if(sldns_buffer_position(pkt)-oldpos > pkt_len) 658238106Sdes return 0; /* dname exceeds rdata */ 659266114Sdes pkt_len -= sldns_buffer_position(pkt)-oldpos; 660238106Sdes rr->size += len; 661238106Sdes count--; 662238106Sdes len = 0; 663238106Sdes break; 664238106Sdes case LDNS_RDF_TYPE_STR: 665249141Sdes if(pkt_len < 1) { 666249141Sdes /* NOTREACHED, due to 'while(>0)' */ 667238106Sdes return 0; /* len byte exceeds rdata */ 668249141Sdes } 669266114Sdes len = sldns_buffer_current(pkt)[0] + 1; 670238106Sdes break; 671238106Sdes default: 672238106Sdes len = get_rdf_size(desc->_wireformat[rdf]); 673238106Sdes } 674238106Sdes if(len) { 675238106Sdes if(pkt_len < len) 676238106Sdes return 0; /* exceeds rdata */ 677238106Sdes pkt_len -= len; 678266114Sdes sldns_buffer_skip(pkt, (ssize_t)len); 679238106Sdes rr->size += len; 680238106Sdes } 681238106Sdes rdf++; 682238106Sdes } 683238106Sdes } 684238106Sdes /* remaining rdata */ 685238106Sdes rr->size += pkt_len; 686266114Sdes sldns_buffer_skip(pkt, (ssize_t)pkt_len); 687238106Sdes return 1; 688238106Sdes} 689238106Sdes 690238106Sdes/** skip rr ttl and rdata */ 691238106Sdesstatic int 692266114Sdesskip_ttl_rdata(sldns_buffer* pkt) 693238106Sdes{ 694238106Sdes uint16_t rdatalen; 695266114Sdes if(sldns_buffer_remaining(pkt) < 6) /* ttl + rdatalen */ 696238106Sdes return 0; 697266114Sdes sldns_buffer_skip(pkt, 4); /* ttl */ 698266114Sdes rdatalen = sldns_buffer_read_u16(pkt); 699266114Sdes if(sldns_buffer_remaining(pkt) < rdatalen) 700238106Sdes return 0; 701266114Sdes sldns_buffer_skip(pkt, (ssize_t)rdatalen); 702238106Sdes return 1; 703238106Sdes} 704238106Sdes 705238106Sdes/** see if RRSIG is a duplicate of another */ 706238106Sdesstatic int 707266114Sdessig_is_double(sldns_buffer* pkt, struct rrset_parse* rrset, uint8_t* ttldata) 708238106Sdes{ 709238106Sdes uint16_t rlen, siglen; 710266114Sdes size_t pos = sldns_buffer_position(pkt); 711238106Sdes struct rr_parse* sig; 712266114Sdes if(sldns_buffer_remaining(pkt) < 6) 713238106Sdes return 0; 714266114Sdes sldns_buffer_skip(pkt, 4); /* ttl */ 715266114Sdes rlen = sldns_buffer_read_u16(pkt); 716266114Sdes if(sldns_buffer_remaining(pkt) < rlen) { 717266114Sdes sldns_buffer_set_position(pkt, pos); 718238106Sdes return 0; 719238106Sdes } 720266114Sdes sldns_buffer_set_position(pkt, pos); 721238106Sdes 722238106Sdes sig = rrset->rrsig_first; 723238106Sdes while(sig) { 724238106Sdes /* check if rdatalen is same */ 725238106Sdes memmove(&siglen, sig->ttl_data+4, sizeof(siglen)); 726238106Sdes siglen = ntohs(siglen); 727238106Sdes /* checks if data in packet is exactly the same, this means 728238106Sdes * also dname in rdata is the same, but rrsig is not allowed 729238106Sdes * to have compressed dnames anyway. If it is compressed anyway 730238106Sdes * it will lead to duplicate rrs for qtype=RRSIG. (or ANY). 731238106Sdes * 732238106Sdes * Cannot use sig->size because size of the other one is not 733238106Sdes * calculated yet. 734238106Sdes */ 735238106Sdes if(siglen == rlen) { 736238106Sdes if(siglen>0 && memcmp(sig->ttl_data+6, ttldata+6, 737238106Sdes siglen) == 0) { 738238106Sdes /* same! */ 739238106Sdes return 1; 740238106Sdes } 741238106Sdes } 742238106Sdes sig = sig->next; 743238106Sdes } 744238106Sdes return 0; 745238106Sdes} 746238106Sdes 747238106Sdes/** Add rr (from packet here) to rrset, skips rr */ 748238106Sdesstatic int 749266114Sdesadd_rr_to_rrset(struct rrset_parse* rrset, sldns_buffer* pkt, 750238106Sdes struct msg_parse* msg, struct regional* region, 751266114Sdes sldns_pkt_section section, uint16_t type) 752238106Sdes{ 753238106Sdes struct rr_parse* rr; 754238106Sdes /* check section of rrset. */ 755238106Sdes if(rrset->section != section && type != LDNS_RR_TYPE_RRSIG && 756238106Sdes rrset->type != LDNS_RR_TYPE_RRSIG) { 757238106Sdes /* silently drop it - we drop the last part, since 758238106Sdes * trust in rr data depends on the section it is in. 759238106Sdes * the less trustworthy part is discarded. 760238106Sdes * also the last part is more likely to be incomplete. 761238106Sdes * RFC 2181: must put RRset only once in response. */ 762238106Sdes /* 763238106Sdes verbose(VERB_QUERY, "Packet contains rrset data in " 764238106Sdes "multiple sections, dropped last part."); 765238106Sdes log_buf(VERB_QUERY, "packet was", pkt); 766238106Sdes */ 767238106Sdes /* forwards */ 768238106Sdes if(!skip_ttl_rdata(pkt)) 769238106Sdes return LDNS_RCODE_FORMERR; 770238106Sdes return 0; 771238106Sdes } 772238106Sdes 773238106Sdes if( (msg->qtype == LDNS_RR_TYPE_RRSIG || 774238106Sdes msg->qtype == LDNS_RR_TYPE_ANY) 775266114Sdes && sig_is_double(pkt, rrset, sldns_buffer_current(pkt))) { 776238106Sdes if(!skip_ttl_rdata(pkt)) 777238106Sdes return LDNS_RCODE_FORMERR; 778238106Sdes return 0; 779238106Sdes } 780238106Sdes 781238106Sdes /* create rr */ 782238106Sdes if(!(rr = (struct rr_parse*)regional_alloc(region, sizeof(*rr)))) 783238106Sdes return LDNS_RCODE_SERVFAIL; 784238106Sdes rr->outside_packet = 0; 785266114Sdes rr->ttl_data = sldns_buffer_current(pkt); 786238106Sdes rr->next = 0; 787238106Sdes if(type == LDNS_RR_TYPE_RRSIG && rrset->type != LDNS_RR_TYPE_RRSIG) { 788238106Sdes if(rrset->rrsig_last) 789238106Sdes rrset->rrsig_last->next = rr; 790238106Sdes else rrset->rrsig_first = rr; 791238106Sdes rrset->rrsig_last = rr; 792238106Sdes rrset->rrsig_count++; 793238106Sdes } else { 794238106Sdes if(rrset->rr_last) 795238106Sdes rrset->rr_last->next = rr; 796238106Sdes else rrset->rr_first = rr; 797238106Sdes rrset->rr_last = rr; 798238106Sdes rrset->rr_count++; 799238106Sdes } 800238106Sdes 801238106Sdes /* calc decompressed size */ 802238106Sdes if(!calc_size(pkt, type, rr)) 803238106Sdes return LDNS_RCODE_FORMERR; 804238106Sdes rrset->size += rr->size; 805238106Sdes 806238106Sdes return 0; 807238106Sdes} 808238106Sdes 809238106Sdes/** 810238106Sdes * Parse packet RR section, for answer, authority and additional sections. 811238106Sdes * @param pkt: packet, position at call must be at start of section. 812238106Sdes * at end position is after section. 813238106Sdes * @param msg: store results here. 814238106Sdes * @param region: how to alloc results. 815238106Sdes * @param section: section enum. 816238106Sdes * @param num_rrs: how many rrs are in the section. 817238106Sdes * @param num_rrsets: returns number of rrsets in the section. 818238106Sdes * @return: 0 if OK, or rcode on error. 819238106Sdes */ 820238106Sdesstatic int 821266114Sdesparse_section(sldns_buffer* pkt, struct msg_parse* msg, 822266114Sdes struct regional* region, sldns_pkt_section section, 823238106Sdes uint16_t num_rrs, size_t* num_rrsets) 824238106Sdes{ 825238106Sdes uint16_t i; 826238106Sdes uint8_t* dname, *prev_dname_f = NULL, *prev_dname_l = NULL; 827238106Sdes size_t dnamelen, prev_dnamelen = 0; 828238106Sdes uint16_t type, prev_type = 0; 829238106Sdes uint16_t dclass, prev_dclass = 0; 830238106Sdes uint32_t rrset_flags = 0; 831356345Scy hashvalue_type hash = 0; 832238106Sdes struct rrset_parse* rrset = NULL; 833238106Sdes int r; 834238106Sdes 835238106Sdes if(num_rrs == 0) 836238106Sdes return 0; 837266114Sdes if(sldns_buffer_remaining(pkt) <= 0) 838238106Sdes return LDNS_RCODE_FORMERR; 839238106Sdes for(i=0; i<num_rrs; i++) { 840238106Sdes /* parse this RR. */ 841266114Sdes dname = sldns_buffer_current(pkt); 842238106Sdes if((dnamelen = pkt_dname_len(pkt)) == 0) 843238106Sdes return LDNS_RCODE_FORMERR; 844266114Sdes if(sldns_buffer_remaining(pkt) < 10) /* type, class, ttl, len */ 845238106Sdes return LDNS_RCODE_FORMERR; 846266114Sdes type = sldns_buffer_read_u16(pkt); 847266114Sdes sldns_buffer_read(pkt, &dclass, sizeof(dclass)); 848238106Sdes 849238106Sdes if(0) { /* debug show what is being parsed. */ 850238106Sdes if(type == LDNS_RR_TYPE_RRSIG) { 851238106Sdes uint16_t t; 852238106Sdes if(pkt_rrsig_covered(pkt, 853266114Sdes sldns_buffer_current(pkt), &t)) 854238106Sdes fprintf(stderr, "parse of %s(%d) [%s(%d)]", 855266114Sdes sldns_rr_descript(type)? 856266114Sdes sldns_rr_descript(type)->_name: "??", 857238106Sdes (int)type, 858266114Sdes sldns_rr_descript(t)? 859266114Sdes sldns_rr_descript(t)->_name: "??", 860238106Sdes (int)t); 861238106Sdes } else 862238106Sdes fprintf(stderr, "parse of %s(%d)", 863266114Sdes sldns_rr_descript(type)? 864266114Sdes sldns_rr_descript(type)->_name: "??", 865238106Sdes (int)type); 866238106Sdes fprintf(stderr, " %s(%d) ", 867266114Sdes sldns_lookup_by_id(sldns_rr_classes, 868266114Sdes (int)ntohs(dclass))?sldns_lookup_by_id( 869266114Sdes sldns_rr_classes, (int)ntohs(dclass))->name: 870238106Sdes "??", (int)ntohs(dclass)); 871238106Sdes dname_print(stderr, pkt, dname); 872238106Sdes fprintf(stderr, "\n"); 873238106Sdes } 874238106Sdes 875238106Sdes /* see if it is part of an existing RR set */ 876238106Sdes if(!find_rrset(msg, pkt, dname, dnamelen, type, dclass, &hash, 877238106Sdes &rrset_flags, &prev_dname_f, &prev_dname_l, 878238106Sdes &prev_dnamelen, &prev_type, &prev_dclass, &rrset, 879238106Sdes section, region)) 880238106Sdes return LDNS_RCODE_SERVFAIL; 881238106Sdes if(!rrset) { 882238106Sdes /* it is a new RR set. hash&flags already calculated.*/ 883238106Sdes (*num_rrsets)++; 884238106Sdes rrset = new_rrset(msg, dname, dnamelen, type, dclass, 885238106Sdes hash, rrset_flags, section, region); 886238106Sdes if(!rrset) 887238106Sdes return LDNS_RCODE_SERVFAIL; 888238106Sdes } 889238106Sdes else if(0) { 890238106Sdes fprintf(stderr, "is part of existing: "); 891238106Sdes dname_print(stderr, pkt, rrset->dname); 892238106Sdes fprintf(stderr, " type %s(%d)\n", 893266114Sdes sldns_rr_descript(rrset->type)? 894266114Sdes sldns_rr_descript(rrset->type)->_name: "??", 895238106Sdes (int)rrset->type); 896238106Sdes } 897238106Sdes /* add to rrset. */ 898238106Sdes if((r=add_rr_to_rrset(rrset, pkt, msg, region, section, 899238106Sdes type)) != 0) 900238106Sdes return r; 901238106Sdes } 902238106Sdes return 0; 903238106Sdes} 904238106Sdes 905238106Sdesint 906266114Sdesparse_packet(sldns_buffer* pkt, struct msg_parse* msg, struct regional* region) 907238106Sdes{ 908238106Sdes int ret; 909266114Sdes if(sldns_buffer_remaining(pkt) < LDNS_HEADER_SIZE) 910238106Sdes return LDNS_RCODE_FORMERR; 911238106Sdes /* read the header */ 912266114Sdes sldns_buffer_read(pkt, &msg->id, sizeof(uint16_t)); 913266114Sdes msg->flags = sldns_buffer_read_u16(pkt); 914266114Sdes msg->qdcount = sldns_buffer_read_u16(pkt); 915266114Sdes msg->ancount = sldns_buffer_read_u16(pkt); 916266114Sdes msg->nscount = sldns_buffer_read_u16(pkt); 917266114Sdes msg->arcount = sldns_buffer_read_u16(pkt); 918238106Sdes if(msg->qdcount > 1) 919238106Sdes return LDNS_RCODE_FORMERR; 920238106Sdes if((ret = parse_query_section(pkt, msg)) != 0) 921238106Sdes return ret; 922238106Sdes if((ret = parse_section(pkt, msg, region, LDNS_SECTION_ANSWER, 923238106Sdes msg->ancount, &msg->an_rrsets)) != 0) 924238106Sdes return ret; 925238106Sdes if((ret = parse_section(pkt, msg, region, LDNS_SECTION_AUTHORITY, 926238106Sdes msg->nscount, &msg->ns_rrsets)) != 0) 927238106Sdes return ret; 928266114Sdes if(sldns_buffer_remaining(pkt) == 0 && msg->arcount == 1) { 929238106Sdes /* BIND accepts leniently that an EDNS record is missing. 930238106Sdes * so, we do too. */ 931238106Sdes } else if((ret = parse_section(pkt, msg, region, 932238106Sdes LDNS_SECTION_ADDITIONAL, msg->arcount, &msg->ar_rrsets)) != 0) 933238106Sdes return ret; 934266114Sdes /* if(sldns_buffer_remaining(pkt) > 0) { */ 935238106Sdes /* there is spurious data at end of packet. ignore */ 936238106Sdes /* } */ 937238106Sdes msg->rrset_count = msg->an_rrsets + msg->ns_rrsets + msg->ar_rrsets; 938238106Sdes return 0; 939238106Sdes} 940238106Sdes 941307729Sdes/** parse EDNS options from EDNS wireformat rdata */ 942307729Sdesstatic int 943307729Sdesparse_edns_options(uint8_t* rdata_ptr, size_t rdata_len, 944307729Sdes struct edns_data* edns, struct regional* region) 945307729Sdes{ 946307729Sdes /* while still more options, and have code+len to read */ 947307729Sdes /* ignores partial content (i.e. rdata len 3) */ 948307729Sdes while(rdata_len >= 4) { 949307729Sdes uint16_t opt_code = sldns_read_uint16(rdata_ptr); 950307729Sdes uint16_t opt_len = sldns_read_uint16(rdata_ptr+2); 951307729Sdes rdata_ptr += 4; 952307729Sdes rdata_len -= 4; 953307729Sdes if(opt_len > rdata_len) 954307729Sdes break; /* option code partial */ 955307729Sdes if(!edns_opt_append(edns, region, opt_code, opt_len, 956307729Sdes rdata_ptr)) { 957307729Sdes log_err("out of memory"); 958307729Sdes return 0; 959307729Sdes } 960307729Sdes rdata_ptr += opt_len; 961307729Sdes rdata_len -= opt_len; 962307729Sdes } 963307729Sdes return 1; 964307729Sdes} 965307729Sdes 966238106Sdesint 967307729Sdesparse_extract_edns(struct msg_parse* msg, struct edns_data* edns, 968307729Sdes struct regional* region) 969238106Sdes{ 970238106Sdes struct rrset_parse* rrset = msg->rrset_first; 971238106Sdes struct rrset_parse* prev = 0; 972238106Sdes struct rrset_parse* found = 0; 973238106Sdes struct rrset_parse* found_prev = 0; 974307729Sdes size_t rdata_len; 975307729Sdes uint8_t* rdata_ptr; 976238106Sdes /* since the class encodes the UDP size, we cannot use hash table to 977238106Sdes * find the EDNS OPT record. Scan the packet. */ 978238106Sdes while(rrset) { 979238106Sdes if(rrset->type == LDNS_RR_TYPE_OPT) { 980238106Sdes /* only one OPT RR allowed. */ 981238106Sdes if(found) return LDNS_RCODE_FORMERR; 982238106Sdes /* found it! */ 983238106Sdes found_prev = prev; 984238106Sdes found = rrset; 985238106Sdes } 986238106Sdes prev = rrset; 987238106Sdes rrset = rrset->rrset_all_next; 988238106Sdes } 989238106Sdes if(!found) { 990238106Sdes memset(edns, 0, sizeof(*edns)); 991238106Sdes edns->udp_size = 512; 992238106Sdes return 0; 993238106Sdes } 994238106Sdes /* check the found RRset */ 995238106Sdes /* most lenient check possible. ignore dname, use last opt */ 996238106Sdes if(found->section != LDNS_SECTION_ADDITIONAL) 997238106Sdes return LDNS_RCODE_FORMERR; 998238106Sdes if(found->rr_count == 0) 999238106Sdes return LDNS_RCODE_FORMERR; 1000238106Sdes if(0) { /* strict checking of dname and RRcount */ 1001238106Sdes if(found->dname_len != 1 || !found->dname 1002238106Sdes || found->dname[0] != 0) return LDNS_RCODE_FORMERR; 1003238106Sdes if(found->rr_count != 1) return LDNS_RCODE_FORMERR; 1004238106Sdes } 1005238106Sdes log_assert(found->rr_first && found->rr_last); 1006238106Sdes 1007238106Sdes /* remove from packet */ 1008238106Sdes if(found_prev) found_prev->rrset_all_next = found->rrset_all_next; 1009238106Sdes else msg->rrset_first = found->rrset_all_next; 1010238106Sdes if(found == msg->rrset_last) 1011238106Sdes msg->rrset_last = found_prev; 1012238106Sdes msg->arcount --; 1013238106Sdes msg->ar_rrsets --; 1014238106Sdes msg->rrset_count --; 1015238106Sdes 1016238106Sdes /* take the data ! */ 1017238106Sdes edns->edns_present = 1; 1018238106Sdes edns->ext_rcode = found->rr_last->ttl_data[0]; 1019238106Sdes edns->edns_version = found->rr_last->ttl_data[1]; 1020266114Sdes edns->bits = sldns_read_uint16(&found->rr_last->ttl_data[2]); 1021238106Sdes edns->udp_size = ntohs(found->rrset_class); 1022307729Sdes edns->opt_list = NULL; 1023369939Sgit2svn edns->padding_block_size = 0; 1024307729Sdes 1025307729Sdes /* take the options */ 1026356345Scy rdata_len = found->rr_first->size-2; 1027307729Sdes rdata_ptr = found->rr_first->ttl_data+6; 1028307729Sdes if(!parse_edns_options(rdata_ptr, rdata_len, edns, region)) 1029307729Sdes return 0; 1030307729Sdes 1031307729Sdes /* ignore rrsigs */ 1032307729Sdes 1033238106Sdes return 0; 1034238106Sdes} 1035238106Sdes 1036356345Scy/** skip RR in packet */ 1037356345Scystatic int 1038356345Scyskip_pkt_rr(sldns_buffer* pkt) 1039356345Scy{ 1040356345Scy if(sldns_buffer_remaining(pkt) < 1) return 0; 1041356345Scy if(!pkt_dname_len(pkt)) 1042356345Scy return 0; 1043356345Scy if(sldns_buffer_remaining(pkt) < 4) return 0; 1044356345Scy sldns_buffer_skip(pkt, 4); /* type and class */ 1045356345Scy if(!skip_ttl_rdata(pkt)) 1046356345Scy return 0; 1047356345Scy return 1; 1048356345Scy} 1049356345Scy 1050356345Scy/** skip RRs from packet */ 1051356345Scystatic int 1052356345Scyskip_pkt_rrs(sldns_buffer* pkt, int num) 1053356345Scy{ 1054356345Scy int i; 1055356345Scy for(i=0; i<num; i++) { 1056356345Scy if(!skip_pkt_rr(pkt)) 1057356345Scy return 0; 1058356345Scy } 1059356345Scy return 1; 1060356345Scy} 1061356345Scy 1062238106Sdesint 1063307729Sdesparse_edns_from_pkt(sldns_buffer* pkt, struct edns_data* edns, 1064307729Sdes struct regional* region) 1065238106Sdes{ 1066307729Sdes size_t rdata_len; 1067307729Sdes uint8_t* rdata_ptr; 1068266114Sdes log_assert(LDNS_QDCOUNT(sldns_buffer_begin(pkt)) == 1); 1069356345Scy memset(edns, 0, sizeof(*edns)); 1070356345Scy if(LDNS_ANCOUNT(sldns_buffer_begin(pkt)) != 0 || 1071356345Scy LDNS_NSCOUNT(sldns_buffer_begin(pkt)) != 0) { 1072356345Scy if(!skip_pkt_rrs(pkt, ((int)LDNS_ANCOUNT(sldns_buffer_begin(pkt)))+ 1073356345Scy ((int)LDNS_NSCOUNT(sldns_buffer_begin(pkt))))) 1074356345Scy return LDNS_RCODE_FORMERR; 1075356345Scy } 1076238106Sdes /* check edns section is present */ 1077266114Sdes if(LDNS_ARCOUNT(sldns_buffer_begin(pkt)) > 1) { 1078238106Sdes return LDNS_RCODE_FORMERR; 1079238106Sdes } 1080266114Sdes if(LDNS_ARCOUNT(sldns_buffer_begin(pkt)) == 0) { 1081238106Sdes edns->udp_size = 512; 1082238106Sdes return 0; 1083238106Sdes } 1084238106Sdes /* domain name must be the root of length 1. */ 1085238106Sdes if(pkt_dname_len(pkt) != 1) 1086238106Sdes return LDNS_RCODE_FORMERR; 1087266114Sdes if(sldns_buffer_remaining(pkt) < 10) /* type, class, ttl, rdatalen */ 1088238106Sdes return LDNS_RCODE_FORMERR; 1089266114Sdes if(sldns_buffer_read_u16(pkt) != LDNS_RR_TYPE_OPT) 1090238106Sdes return LDNS_RCODE_FORMERR; 1091238106Sdes edns->edns_present = 1; 1092266114Sdes edns->udp_size = sldns_buffer_read_u16(pkt); /* class is udp size */ 1093266114Sdes edns->ext_rcode = sldns_buffer_read_u8(pkt); /* ttl used for bits */ 1094266114Sdes edns->edns_version = sldns_buffer_read_u8(pkt); 1095266114Sdes edns->bits = sldns_buffer_read_u16(pkt); 1096307729Sdes edns->opt_list = NULL; 1097369939Sgit2svn edns->padding_block_size = 0; 1098307729Sdes 1099307729Sdes /* take the options */ 1100307729Sdes rdata_len = sldns_buffer_read_u16(pkt); 1101307729Sdes if(sldns_buffer_remaining(pkt) < rdata_len) 1102307729Sdes return LDNS_RCODE_FORMERR; 1103307729Sdes rdata_ptr = sldns_buffer_current(pkt); 1104307729Sdes if(!parse_edns_options(rdata_ptr, rdata_len, edns, region)) 1105307729Sdes return LDNS_RCODE_SERVFAIL; 1106307729Sdes 1107307729Sdes /* ignore rrsigs */ 1108307729Sdes 1109238106Sdes return 0; 1110238106Sdes} 1111356345Scy 1112356345Scyvoid 1113356345Scylog_edns_opt_list(enum verbosity_value level, const char* info_str, 1114356345Scy struct edns_option* list) 1115356345Scy{ 1116356345Scy if(verbosity >= level && list) { 1117356345Scy char str[128], *s; 1118356345Scy size_t slen; 1119356345Scy verbose(level, "%s", info_str); 1120356345Scy while(list) { 1121356345Scy s = str; 1122356345Scy slen = sizeof(str); 1123356345Scy (void)sldns_wire2str_edns_option_print(&s, &slen, list->opt_code, 1124356345Scy list->opt_data, list->opt_len); 1125356345Scy verbose(level, " %s", str); 1126356345Scy list = list->next; 1127356345Scy } 1128356345Scy } 1129356345Scy} 1130