util/data/msgreply.c

   1 /*
   2  * util/data/msgreply.c - store message and reply data.
   3  *
   4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
   5  *
   6  * This software is open source.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * Redistributions of source code must retain the above copyright notice,
  13  * this list of conditions and the following disclaimer.
  14  *
  15  * Redistributions in binary form must reproduce the above copyright notice,
  16  * this list of conditions and the following disclaimer in the documentation
  17  * and/or other materials provided with the distribution.
  18  *
  19  * Neither the name of the NLNET LABS nor the names of its contributors may
  20  * be used to endorse or promote products derived from this software without
  21  * specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  34  */
  35
  36 /**
  37  * \file
  38  *
  39  * This file contains a data structure to store a message and its reply.
  40  */
  41
  42 #include "config.h"
  43 #include "util/data/msgreply.h"
  44 #include "util/storage/lookup3.h"
  45 #include "util/log.h"
  46 #include "util/alloc.h"
  47 #include "util/netevent.h"
  48 #include "util/net_help.h"
  49 #include "util/data/dname.h"
  50 #include "util/regional.h"
  51 #include "util/data/msgparse.h"
  52 #include "util/data/msgencode.h"
  53 #include "sldns/sbuffer.h"
  54 #include "sldns/wire2str.h"
  55 #include "util/module.h"
  56 #include "util/fptr_wlist.h"
  57
  58 /** MAX TTL default for messages and rrsets */
  59 time_t MAX_TTL = 3600 * 24 * 10; /* ten days */
  60 /** MIN TTL default for messages and rrsets */
  61 time_t MIN_TTL = 0;
  62 /** MAX Negative TTL, for SOA records in authority section */
  63 time_t MAX_NEG_TTL = 3600; /* one hour */
  64
  65 /** allocate qinfo, return 0 on error */
  66 static int
  67 parse_create_qinfo(sldns_buffer* pkt, struct msg_parse* msg,
  68         struct query_info* qinf, struct regional* region)
  69 {
  70         if(msg->qname) {
  71                 if(region)
  72                         qinf->qname = (uint8_t*)regional_alloc(region,
  73                                 msg->qname_len);
  74                 else    qinf->qname = (uint8_t*)malloc(msg->qname_len);
  75                 if(!qinf->qname) return 0;
  76                 dname_pkt_copy(pkt, qinf->qname, msg->qname);
  77         } else  qinf->qname = 0;
  78         qinf->qname_len = msg->qname_len;
  79         qinf->qtype = msg->qtype;
  80         qinf->qclass = msg->qclass;
  81         qinf->local_alias = NULL;
  82         return 1;
  83 }
  84
  85 /** constructor for replyinfo */
  86 struct reply_info*
  87 construct_reply_info_base(struct regional* region, uint16_t flags, size_t qd,
  88         time_t ttl, time_t prettl, size_t an, size_t ns, size_t ar,
  89         size_t total, enum sec_status sec)
  90 {
  91         struct reply_info* rep;
  92         /* rrset_count-1 because the first ref is part of the struct. */
  93         size_t s = sizeof(struct reply_info) - sizeof(struct rrset_ref) +
  94                 sizeof(struct ub_packed_rrset_key*) * total;
  95         if(total >= RR_COUNT_MAX) return NULL; /* sanity check on numRRS*/
  96         if(region)
  97                 rep = (struct reply_info*)regional_alloc(region, s);
  98         else    rep = (struct reply_info*)malloc(s +
  99                         sizeof(struct rrset_ref) * (total));
 100         if(!rep)
 101                 return NULL;
 102         rep->flags = flags;
 103         rep->qdcount = qd;
 104         rep->ttl = ttl;
 105         rep->prefetch_ttl = prettl;
 106         rep->an_numrrsets = an;
 107         rep->ns_numrrsets = ns;
 108         rep->ar_numrrsets = ar;
 109         rep->rrset_count = total;
 110         rep->security = sec;
 111         rep->authoritative = 0;
 112         /* array starts after the refs */
 113         if(region)
 114                 rep->rrsets = (struct ub_packed_rrset_key**)&(rep->ref[0]);
 115         else    rep->rrsets = (struct ub_packed_rrset_key**)&(rep->ref[total]);
 116         /* zero the arrays to assist cleanup in case of malloc failure */
 117         memset( rep->rrsets, 0, sizeof(struct ub_packed_rrset_key*) * total);
 118         if(!region)
 119                 memset( &rep->ref[0], 0, sizeof(struct rrset_ref) * total);
 120         return rep;
 121 }
 122
 123 /** allocate replyinfo, return 0 on error */
 124 static int
 125 parse_create_repinfo(struct msg_parse* msg, struct reply_info** rep,
 126         struct regional* region)
 127 {
 128         *rep = construct_reply_info_base(region, msg->flags, msg->qdcount, 0,
 129                 0, msg->an_rrsets, msg->ns_rrsets, msg->ar_rrsets,
 130                 msg->rrset_count, sec_status_unchecked);
 131         if(!*rep)
 132                 return 0;
 133         return 1;
 134 }
 135
 136 int
 137 reply_info_alloc_rrset_keys(struct reply_info* rep, struct alloc_cache* alloc,
 138         struct regional* region)
 139 {
 140         size_t i;
 141         for(i=0; i<rep->rrset_count; i++) {
 142                 if(region) {
 143                         rep->rrsets[i] = (struct ub_packed_rrset_key*)
 144                                 regional_alloc(region,
 145                                 sizeof(struct ub_packed_rrset_key));
 146                         if(rep->rrsets[i]) {
 147                                 memset(rep->rrsets[i], 0,
 148                                         sizeof(struct ub_packed_rrset_key));
 149                                 rep->rrsets[i]->entry.key = rep->rrsets[i];
 150                         }
 151                 }
 152                 else    rep->rrsets[i] = alloc_special_obtain(alloc);
 153                 if(!rep->rrsets[i])
 154                         return 0;
 155                 rep->rrsets[i]->entry.data = NULL;
 156         }
 157         return 1;
 158 }
 159
 160 /** find the minimumttl in the rdata of SOA record */
 161 static time_t
 162 soa_find_minttl(struct rr_parse* rr)
 163 {
 164         uint16_t rlen = sldns_read_uint16(rr->ttl_data+4);
 165         if(rlen < 20)
 166                 return 0; /* rdata too small for SOA (dname, dname, 5*32bit) */
 167         /* minimum TTL is the last 32bit value in the rdata of the record */
 168         /* at position ttl_data + 4(ttl) + 2(rdatalen) + rdatalen - 4(timeval)*/
 169         return (time_t)sldns_read_uint32(rr->ttl_data+6+rlen-4);
 170 }
 171
 172 /** do the rdata copy */
 173 static int
 174 rdata_copy(sldns_buffer* pkt, struct packed_rrset_data* data, uint8_t* to,
 175         struct rr_parse* rr, time_t* rr_ttl, uint16_t type,
 176         sldns_pkt_section section)
 177 {
 178         uint16_t pkt_len;
 179         const sldns_rr_descriptor* desc;
 180
 181         *rr_ttl = sldns_read_uint32(rr->ttl_data);
 182         /* RFC 2181 Section 8. if msb of ttl is set treat as if zero. */
 183         if(*rr_ttl & 0x80000000U)
 184                 *rr_ttl = 0;
 185         if(type == LDNS_RR_TYPE_SOA && section == LDNS_SECTION_AUTHORITY) {
 186                 /* negative response. see if TTL of SOA record larger than the
 187                  * minimum-ttl in the rdata of the SOA record */
 188                 if(*rr_ttl > soa_find_minttl(rr))
 189                         *rr_ttl = soa_find_minttl(rr);
 190                 if(*rr_ttl > MAX_NEG_TTL)
 191                         *rr_ttl = MAX_NEG_TTL;
 192         }
 193         if(*rr_ttl < MIN_TTL)
 194                 *rr_ttl = MIN_TTL;
 195         if(*rr_ttl < data->ttl)
 196                 data->ttl = *rr_ttl;
 197
 198         if(rr->outside_packet) {
 199                 /* uncompressed already, only needs copy */
 200                 memmove(to, rr->ttl_data+sizeof(uint32_t), rr->size);
 201                 return 1;
 202         }
 203
 204         sldns_buffer_set_position(pkt, (size_t)
 205                 (rr->ttl_data - sldns_buffer_begin(pkt) + sizeof(uint32_t)));
 206         /* insert decompressed size into rdata len stored in memory */
 207         /* -2 because rdatalen bytes are not included. */
 208         pkt_len = htons(rr->size - 2);
 209         memmove(to, &pkt_len, sizeof(uint16_t));
 210         to += 2;
 211         /* read packet rdata len */
 212         pkt_len = sldns_buffer_read_u16(pkt);
 213         if(sldns_buffer_remaining(pkt) < pkt_len)
 214                 return 0;
 215         desc = sldns_rr_descript(type);
 216         if(pkt_len > 0 && desc && desc->_dname_count > 0) {
 217                 int count = (int)desc->_dname_count;
 218                 int rdf = 0;
 219                 size_t len;
 220                 size_t oldpos;
 221                 /* decompress dnames. */
 222                 while(pkt_len > 0 && count) {
 223                         switch(desc->_wireformat[rdf]) {
 224                         case LDNS_RDF_TYPE_DNAME:
 225                                 oldpos = sldns_buffer_position(pkt);
 226                                 dname_pkt_copy(pkt, to,
 227                                         sldns_buffer_current(pkt));
 228                                 to += pkt_dname_len(pkt);
 229                                 pkt_len -= sldns_buffer_position(pkt)-oldpos;
 230                                 count--;
 231                                 len = 0;
 232                                 break;
 233                         case LDNS_RDF_TYPE_STR:
 234                                 len = sldns_buffer_current(pkt)[0] + 1;
 235                                 break;
 236                         default:
 237                                 len = get_rdf_size(desc->_wireformat[rdf]);
 238                                 break;
 239                         }
 240                         if(len) {
 241                                 memmove(to, sldns_buffer_current(pkt), len);
 242                                 to += len;
 243                                 sldns_buffer_skip(pkt, (ssize_t)len);
 244                                 log_assert(len <= pkt_len);
 245                                 pkt_len -= len;
 246                         }
 247                         rdf++;
 248                 }
 249         }
 250         /* copy remaining rdata */
 251         if(pkt_len >  0)
 252                 memmove(to, sldns_buffer_current(pkt), pkt_len);
 253
 254         return 1;
 255 }
 256
 257 /** copy over the data into packed rrset */
 258 static int
 259 parse_rr_copy(sldns_buffer* pkt, struct rrset_parse* pset,
 260         struct packed_rrset_data* data)
 261 {
 262         size_t i;
 263         struct rr_parse* rr = pset->rr_first;
 264         uint8_t* nextrdata;
 265         size_t total = pset->rr_count + pset->rrsig_count;
 266         data->ttl = MAX_TTL;
 267         data->count = pset->rr_count;
 268         data->rrsig_count = pset->rrsig_count;
 269         data->trust = rrset_trust_none;
 270         data->security = sec_status_unchecked;
 271         /* layout: struct - rr_len - rr_data - rr_ttl - rdata - rrsig */
 272         data->rr_len = (size_t*)((uint8_t*)data +
 273                 sizeof(struct packed_rrset_data));
 274         data->rr_data = (uint8_t**)&(data->rr_len[total]);
 275         data->rr_ttl = (time_t*)&(data->rr_data[total]);
 276         nextrdata = (uint8_t*)&(data->rr_ttl[total]);
 277         for(i=0; i<data->count; i++) {
 278                 data->rr_len[i] = rr->size;
 279                 data->rr_data[i] = nextrdata;
 280                 nextrdata += rr->size;
 281                 if(!rdata_copy(pkt, data, data->rr_data[i], rr,
 282                         &data->rr_ttl[i], pset->type, pset->section))
 283                         return 0;
 284                 rr = rr->next;
 285         }
 286         /* if rrsig, its rdata is at nextrdata */
 287         rr = pset->rrsig_first;
 288         for(i=data->count; i<total; i++) {
 289                 data->rr_len[i] = rr->size;
 290                 data->rr_data[i] = nextrdata;
 291                 nextrdata += rr->size;
 292                 if(!rdata_copy(pkt, data, data->rr_data[i], rr,
 293                         &data->rr_ttl[i], LDNS_RR_TYPE_RRSIG, pset->section))
 294                         return 0;
 295                 rr = rr->next;
 296         }
 297         return 1;
 298 }
 299
 300 /** create rrset return 0 on failure */
 301 static int
 302 parse_create_rrset(sldns_buffer* pkt, struct rrset_parse* pset,
 303         struct packed_rrset_data** data, struct regional* region)
 304 {
 305         /* allocate */
 306         size_t s;
 307         if(pset->rr_count > RR_COUNT_MAX || pset->rrsig_count > RR_COUNT_MAX ||
 308                 pset->size > RR_COUNT_MAX)
 309                 return 0; /* protect against integer overflow */
 310         s = sizeof(struct packed_rrset_data) +
 311                 (pset->rr_count + pset->rrsig_count) *
 312                 (sizeof(size_t)+sizeof(uint8_t*)+sizeof(time_t)) +
 313                 pset->size;
 314         if(region)
 315                 *data = regional_alloc(region, s);
 316         else    *data = malloc(s);
 317         if(!*data)
 318                 return 0;
 319         /* copy & decompress */
 320         if(!parse_rr_copy(pkt, pset, *data)) {
 321                 if(!region) free(*data);
 322                 return 0;
 323         }
 324         return 1;
 325 }
 326
 327 /** get trust value for rrset */
 328 static enum rrset_trust
 329 get_rrset_trust(struct msg_parse* msg, struct rrset_parse* rrset)
 330 {
 331         uint16_t AA = msg->flags & BIT_AA;
 332         if(rrset->section == LDNS_SECTION_ANSWER) {
 333                 if(AA) {
 334                         /* RFC2181 says remainder of CNAME chain is nonauth*/
 335                         if(msg->rrset_first &&
 336                                 msg->rrset_first->section==LDNS_SECTION_ANSWER
 337                                 && msg->rrset_first->type==LDNS_RR_TYPE_CNAME){
 338                                 if(rrset == msg->rrset_first)
 339                                         return rrset_trust_ans_AA;
 340                                 else    return rrset_trust_ans_noAA;
 341                         }
 342                         if(msg->rrset_first &&
 343                                 msg->rrset_first->section==LDNS_SECTION_ANSWER
 344                                 && msg->rrset_first->type==LDNS_RR_TYPE_DNAME){
 345                                 if(rrset == msg->rrset_first ||
 346                                    rrset == msg->rrset_first->rrset_all_next)
 347                                         return rrset_trust_ans_AA;
 348                                 else    return rrset_trust_ans_noAA;
 349                         }
 350                         return rrset_trust_ans_AA;
 351                 }
 352                 else    return rrset_trust_ans_noAA;
 353         } else if(rrset->section == LDNS_SECTION_AUTHORITY) {
 354                 if(AA)  return rrset_trust_auth_AA;
 355                 else    return rrset_trust_auth_noAA;
 356         } else {
 357                 /* addit section */
 358                 if(AA)  return rrset_trust_add_AA;
 359                 else    return rrset_trust_add_noAA;
 360         }
 361         /* NOTREACHED */
 362         return rrset_trust_none;
 363 }
 364
 365 int
 366 parse_copy_decompress_rrset(sldns_buffer* pkt, struct msg_parse* msg,
 367         struct rrset_parse *pset, struct regional* region,
 368         struct ub_packed_rrset_key* pk)
 369 {
 370         struct packed_rrset_data* data;
 371         pk->rk.flags = pset->flags;
 372         pk->rk.dname_len = pset->dname_len;
 373         if(region)
 374                 pk->rk.dname = (uint8_t*)regional_alloc(
 375                         region, pset->dname_len);
 376         else    pk->rk.dname =
 377                         (uint8_t*)malloc(pset->dname_len);
 378         if(!pk->rk.dname)
 379                 return 0;
 380         /** copy & decompress dname */
 381         dname_pkt_copy(pkt, pk->rk.dname, pset->dname);
 382         /** copy over type and class */
 383         pk->rk.type = htons(pset->type);
 384         pk->rk.rrset_class = pset->rrset_class;
 385         /** read data part. */
 386         if(!parse_create_rrset(pkt, pset, &data, region))
 387                 return 0;
 388         pk->entry.data = (void*)data;
 389         pk->entry.key = (void*)pk;
 390         pk->entry.hash = pset->hash;
 391         data->trust = get_rrset_trust(msg, pset);
 392         return 1;
 393 }
 394
 395 /**
 396  * Copy and decompress rrs
 397  * @param pkt: the packet for compression pointer resolution.
 398  * @param msg: the parsed message
 399  * @param rep: reply info to put rrs into.
 400  * @param region: if not NULL, used for allocation.
 401  * @return 0 on failure.
 402  */
 403 static int
 404 parse_copy_decompress(sldns_buffer* pkt, struct msg_parse* msg,
 405         struct reply_info* rep, struct regional* region)
 406 {
 407         size_t i;
 408         struct rrset_parse *pset = msg->rrset_first;
 409         struct packed_rrset_data* data;
 410         log_assert(rep);
 411         rep->ttl = MAX_TTL;
 412         rep->security = sec_status_unchecked;
 413         if(rep->rrset_count == 0)
 414                 rep->ttl = NORR_TTL;
 415
 416         for(i=0; i<rep->rrset_count; i++) {
 417                 if(!parse_copy_decompress_rrset(pkt, msg, pset, region,
 418                         rep->rrsets[i]))
 419                         return 0;
 420                 data = (struct packed_rrset_data*)rep->rrsets[i]->entry.data;
 421                 if(data->ttl < rep->ttl)
 422                         rep->ttl = data->ttl;
 423
 424                 pset = pset->rrset_all_next;
 425         }
 426         rep->prefetch_ttl = PREFETCH_TTL_CALC(rep->ttl);
 427         return 1;
 428 }
 429
 430 int
 431 parse_create_msg(sldns_buffer* pkt, struct msg_parse* msg,
 432         struct alloc_cache* alloc, struct query_info* qinf,
 433         struct reply_info** rep, struct regional* region)
 434 {
 435         log_assert(pkt && msg);
 436         if(!parse_create_qinfo(pkt, msg, qinf, region))
 437                 return 0;
 438         if(!parse_create_repinfo(msg, rep, region))
 439                 return 0;
 440         if(!reply_info_alloc_rrset_keys(*rep, alloc, region))
 441                 return 0;
 442         if(!parse_copy_decompress(pkt, msg, *rep, region))
 443                 return 0;
 444         return 1;
 445 }
 446
 447 int reply_info_parse(sldns_buffer* pkt, struct alloc_cache* alloc,
 448         struct query_info* qinf, struct reply_info** rep,
 449         struct regional* region, struct edns_data* edns)
 450 {
 451         /* use scratch pad region-allocator during parsing. */
 452         struct msg_parse* msg;
 453         int ret;
 454
 455         qinf->qname = NULL;
 456         qinf->local_alias = NULL;
 457         *rep = NULL;
 458         if(!(msg = regional_alloc(region, sizeof(*msg)))) {
 459                 return LDNS_RCODE_SERVFAIL;
 460         }
 461         memset(msg, 0, sizeof(*msg));
 462
 463         sldns_buffer_set_position(pkt, 0);
 464         if((ret = parse_packet(pkt, msg, region)) != 0) {
 465                 return ret;
 466         }
 467         if((ret = parse_extract_edns(msg, edns, region)) != 0)
 468                 return ret;
 469
 470         /* parse OK, allocate return structures */
 471         /* this also performs dname decompression */
 472         if(!parse_create_msg(pkt, msg, alloc, qinf, rep, NULL)) {
 473                 query_info_clear(qinf);
 474                 reply_info_parsedelete(*rep, alloc);
 475                 *rep = NULL;
 476                 return LDNS_RCODE_SERVFAIL;
 477         }
 478         return 0;
 479 }
 480
 481 /** helper compare function to sort in lock order */
 482 static int
 483 reply_info_sortref_cmp(const void* a, const void* b)
 484 {
 485         struct rrset_ref* x = (struct rrset_ref*)a;
 486         struct rrset_ref* y = (struct rrset_ref*)b;
 487         if(x->key < y->key) return -1;
 488         if(x->key > y->key) return 1;
 489         return 0;
 490 }
 491
 492 void
 493 reply_info_sortref(struct reply_info* rep)
 494 {
 495         qsort(&rep->ref[0], rep->rrset_count, sizeof(struct rrset_ref),
 496                 reply_info_sortref_cmp);
 497 }
 498
 499 void
 500 reply_info_set_ttls(struct reply_info* rep, time_t timenow)
 501 {
 502         size_t i, j;
 503         rep->ttl += timenow;
 504         rep->prefetch_ttl += timenow;
 505         for(i=0; i<rep->rrset_count; i++) {
 506                 struct packed_rrset_data* data = (struct packed_rrset_data*)
 507                         rep->ref[i].key->entry.data;
 508                 if(i>0 && rep->ref[i].key == rep->ref[i-1].key)
 509                         continue;
 510                 data->ttl += timenow;
 511                 for(j=0; j<data->count + data->rrsig_count; j++) {
 512                         data->rr_ttl[j] += timenow;
 513                 }
 514         }
 515 }
 516
 517 void
 518 reply_info_parsedelete(struct reply_info* rep, struct alloc_cache* alloc)
 519 {
 520         size_t i;
 521         if(!rep)
 522                 return;
 523         /* no need to lock, since not shared in hashtables. */
 524         for(i=0; i<rep->rrset_count; i++) {
 525                 ub_packed_rrset_parsedelete(rep->rrsets[i], alloc);
 526         }
 527         free(rep);
 528 }
 529
 530 int
 531 query_info_parse(struct query_info* m, sldns_buffer* query)
 532 {
 533         uint8_t* q = sldns_buffer_begin(query);
 534         /* minimum size: header + \0 + qtype + qclass */
 535         if(sldns_buffer_limit(query) < LDNS_HEADER_SIZE + 5)
 536                 return 0;
 537         if(LDNS_OPCODE_WIRE(q) != LDNS_PACKET_QUERY ||
 538                 LDNS_QDCOUNT(q) != 1 || sldns_buffer_position(query) != 0)
 539                 return 0;
 540         sldns_buffer_skip(query, LDNS_HEADER_SIZE);
 541         m->qname = sldns_buffer_current(query);
 542         if((m->qname_len = query_dname_len(query)) == 0)
 543                 return 0; /* parse error */
 544         if(sldns_buffer_remaining(query) < 4)
 545                 return 0; /* need qtype, qclass */
 546         m->qtype = sldns_buffer_read_u16(query);
 547         m->qclass = sldns_buffer_read_u16(query);
 548         m->local_alias = NULL;
 549         return 1;
 550 }
 551
 552 /** tiny subroutine for msgreply_compare */
 553 #define COMPARE_IT(x, y) \
 554         if( (x) < (y) ) return -1; \
 555         else if( (x) > (y) ) return +1; \
 556         log_assert( (x) == (y) );
 557
 558 int
 559 query_info_compare(void* m1, void* m2)
 560 {
 561         struct query_info* msg1 = (struct query_info*)m1;
 562         struct query_info* msg2 = (struct query_info*)m2;
 563         int mc;
 564         /* from most different to least different for speed */
 565         COMPARE_IT(msg1->qtype, msg2->qtype);
 566         if((mc = query_dname_compare(msg1->qname, msg2->qname)) != 0)
 567                 return mc;
 568         log_assert(msg1->qname_len == msg2->qname_len);
 569         COMPARE_IT(msg1->qclass, msg2->qclass);
 570         return 0;
 571 #undef COMPARE_IT
 572 }
 573
 574 void
 575 query_info_clear(struct query_info* m)
 576 {
 577         free(m->qname);
 578         m->qname = NULL;
 579 }
 580
 581 size_t
 582 msgreply_sizefunc(void* k, void* d)
 583 {
 584         struct msgreply_entry* q = (struct msgreply_entry*)k;
 585         struct reply_info* r = (struct reply_info*)d;
 586         size_t s = sizeof(struct msgreply_entry) + sizeof(struct reply_info)
 587                 + q->key.qname_len + lock_get_mem(&q->entry.lock)
 588                 - sizeof(struct rrset_ref);
 589         s += r->rrset_count * sizeof(struct rrset_ref);
 590         s += r->rrset_count * sizeof(struct ub_packed_rrset_key*);
 591         return s;
 592 }
 593
 594 void
 595 query_entry_delete(void *k, void* ATTR_UNUSED(arg))
 596 {
 597         struct msgreply_entry* q = (struct msgreply_entry*)k;
 598         lock_rw_destroy(&q->entry.lock);
 599         query_info_clear(&q->key);
 600         free(q);
 601 }
 602
 603 void
 604 reply_info_delete(void* d, void* ATTR_UNUSED(arg))
 605 {
 606         struct reply_info* r = (struct reply_info*)d;
 607         free(r);
 608 }
 609
 610 hashvalue_type
 611 query_info_hash(struct query_info *q, uint16_t flags)
 612 {
 613         hashvalue_type h = 0xab;
 614         h = hashlittle(&q->qtype, sizeof(q->qtype), h);
 615         if(q->qtype == LDNS_RR_TYPE_AAAA && (flags&BIT_CD))
 616                 h++;
 617         h = hashlittle(&q->qclass, sizeof(q->qclass), h);
 618         h = dname_query_hash(q->qname, h);
 619         return h;
 620 }
 621
 622 struct msgreply_entry*
 623 query_info_entrysetup(struct query_info* q, struct reply_info* r,
 624         hashvalue_type h)
 625 {
 626         struct msgreply_entry* e = (struct msgreply_entry*)malloc(
 627                 sizeof(struct msgreply_entry));
 628         if(!e) return NULL;
 629         memcpy(&e->key, q, sizeof(*q));
 630         e->entry.hash = h;
 631         e->entry.key = e;
 632         e->entry.data = r;
 633         lock_rw_init(&e->entry.lock);
 634         lock_protect(&e->entry.lock, &e->key, sizeof(e->key));
 635         lock_protect(&e->entry.lock, &e->entry.hash, sizeof(e->entry.hash) +
 636                 sizeof(e->entry.key) + sizeof(e->entry.data));
 637         lock_protect(&e->entry.lock, e->key.qname, e->key.qname_len);
 638         q->qname = NULL;
 639         return e;
 640 }
 641
 642 /** copy rrsets from replyinfo to dest replyinfo */
 643 static int
 644 repinfo_copy_rrsets(struct reply_info* dest, struct reply_info* from,
 645         struct regional* region)
 646 {
 647         size_t i, s;
 648         struct packed_rrset_data* fd, *dd;
 649         struct ub_packed_rrset_key* fk, *dk;
 650         for(i=0; i<dest->rrset_count; i++) {
 651                 fk = from->rrsets[i];
 652                 dk = dest->rrsets[i];
 653                 fd = (struct packed_rrset_data*)fk->entry.data;
 654                 dk->entry.hash = fk->entry.hash;
 655                 dk->rk = fk->rk;
 656                 if(region) {
 657                         dk->id = fk->id;
 658                         dk->rk.dname = (uint8_t*)regional_alloc_init(region,
 659                                 fk->rk.dname, fk->rk.dname_len);
 660                 } else
 661                         dk->rk.dname = (uint8_t*)memdup(fk->rk.dname,
 662                                 fk->rk.dname_len);
 663                 if(!dk->rk.dname)
 664                         return 0;
 665                 s = packed_rrset_sizeof(fd);
 666                 if(region)
 667                         dd = (struct packed_rrset_data*)regional_alloc_init(
 668                                 region, fd, s);
 669                 else    dd = (struct packed_rrset_data*)memdup(fd, s);
 670                 if(!dd)
 671                         return 0;
 672                 packed_rrset_ptr_fixup(dd);
 673                 dk->entry.data = (void*)dd;
 674         }
 675         return 1;
 676 }
 677
 678 struct reply_info*
 679 reply_info_copy(struct reply_info* rep, struct alloc_cache* alloc,
 680         struct regional* region)
 681 {
 682         struct reply_info* cp;
 683         cp = construct_reply_info_base(region, rep->flags, rep->qdcount,
 684                 rep->ttl, rep->prefetch_ttl, rep->an_numrrsets,
 685                 rep->ns_numrrsets, rep->ar_numrrsets, rep->rrset_count,
 686                 rep->security);
 687         if(!cp)
 688                 return NULL;
 689         /* allocate ub_key structures special or not */
 690         if(!reply_info_alloc_rrset_keys(cp, alloc, region)) {
 691                 if(!region)
 692                         reply_info_parsedelete(cp, alloc);
 693                 return NULL;
 694         }
 695         if(!repinfo_copy_rrsets(cp, rep, region)) {
 696                 if(!region)
 697                         reply_info_parsedelete(cp, alloc);
 698                 return NULL;
 699         }
 700         return cp;
 701 }
 702
 703 uint8_t*
 704 reply_find_final_cname_target(struct query_info* qinfo, struct reply_info* rep)
 705 {
 706         uint8_t* sname = qinfo->qname;
 707         size_t snamelen = qinfo->qname_len;
 708         size_t i;
 709         for(i=0; i<rep->an_numrrsets; i++) {
 710                 struct ub_packed_rrset_key* s = rep->rrsets[i];
 711                 /* follow CNAME chain (if any) */
 712                 if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME &&
 713                         ntohs(s->rk.rrset_class) == qinfo->qclass &&
 714                         snamelen == s->rk.dname_len &&
 715                         query_dname_compare(sname, s->rk.dname) == 0) {
 716                         get_cname_target(s, &sname, &snamelen);
 717                 }
 718         }
 719         if(sname != qinfo->qname)
 720                 return sname;
 721         return NULL;
 722 }
 723
 724 struct ub_packed_rrset_key*
 725 reply_find_answer_rrset(struct query_info* qinfo, struct reply_info* rep)
 726 {
 727         uint8_t* sname = qinfo->qname;
 728         size_t snamelen = qinfo->qname_len;
 729         size_t i;
 730         for(i=0; i<rep->an_numrrsets; i++) {
 731                 struct ub_packed_rrset_key* s = rep->rrsets[i];
 732                 /* first match type, for query of qtype cname */
 733                 if(ntohs(s->rk.type) == qinfo->qtype &&
 734                         ntohs(s->rk.rrset_class) == qinfo->qclass &&
 735                         snamelen == s->rk.dname_len &&
 736                         query_dname_compare(sname, s->rk.dname) == 0) {
 737                         return s;
 738                 }
 739                 /* follow CNAME chain (if any) */
 740                 if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME &&
 741                         ntohs(s->rk.rrset_class) == qinfo->qclass &&
 742                         snamelen == s->rk.dname_len &&
 743                         query_dname_compare(sname, s->rk.dname) == 0) {
 744                         get_cname_target(s, &sname, &snamelen);
 745                 }
 746         }
 747         return NULL;
 748 }
 749
 750 struct ub_packed_rrset_key* reply_find_rrset_section_an(struct reply_info* rep,
 751         uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
 752 {
 753         size_t i;
 754         for(i=0; i<rep->an_numrrsets; i++) {
 755                 struct ub_packed_rrset_key* s = rep->rrsets[i];
 756                 if(ntohs(s->rk.type) == type &&
 757                         ntohs(s->rk.rrset_class) == dclass &&
 758                         namelen == s->rk.dname_len &&
 759                         query_dname_compare(name, s->rk.dname) == 0) {
 760                         return s;
 761                 }
 762         }
 763         return NULL;
 764 }
 765
 766 struct ub_packed_rrset_key* reply_find_rrset_section_ns(struct reply_info* rep,
 767         uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
 768 {
 769         size_t i;
 770         for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) {
 771                 struct ub_packed_rrset_key* s = rep->rrsets[i];
 772                 if(ntohs(s->rk.type) == type &&
 773                         ntohs(s->rk.rrset_class) == dclass &&
 774                         namelen == s->rk.dname_len &&
 775                         query_dname_compare(name, s->rk.dname) == 0) {
 776                         return s;
 777                 }
 778         }
 779         return NULL;
 780 }
 781
 782 struct ub_packed_rrset_key* reply_find_rrset(struct reply_info* rep,
 783         uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
 784 {
 785         size_t i;
 786         for(i=0; i<rep->rrset_count; i++) {
 787                 struct ub_packed_rrset_key* s = rep->rrsets[i];
 788                 if(ntohs(s->rk.type) == type &&
 789                         ntohs(s->rk.rrset_class) == dclass &&
 790                         namelen == s->rk.dname_len &&
 791                         query_dname_compare(name, s->rk.dname) == 0) {
 792                         return s;
 793                 }
 794         }
 795         return NULL;
 796 }
 797
 798 void
 799 log_dns_msg(const char* str, struct query_info* qinfo, struct reply_info* rep)
 800 {
 801         /* not particularly fast but flexible, make wireformat and print */
 802         sldns_buffer* buf = sldns_buffer_new(65535);
 803         struct regional* region = regional_create();
 804         if(!reply_info_encode(qinfo, rep, 0, rep->flags, buf, 0,
 805                 region, 65535, 1)) {
 806                 log_info("%s: log_dns_msg: out of memory", str);
 807         } else {
 808                 char* s = sldns_wire2str_pkt(sldns_buffer_begin(buf),
 809                         sldns_buffer_limit(buf));
 810                 if(!s) {
 811                         log_info("%s: log_dns_msg: ldns tostr failed", str);
 812                 } else {
 813                         log_info("%s %s", str, s);
 814                 }
 815                 free(s);
 816         }
 817         sldns_buffer_free(buf);
 818         regional_destroy(region);
 819 }
 820
 821 void
 822 log_reply_info(enum verbosity_value v, struct query_info *qinf,
 823         struct sockaddr_storage *addr, socklen_t addrlen, struct timeval dur,
 824         int cached, struct sldns_buffer *rmsg)
 825 {
 826         char qname_buf[LDNS_MAX_DOMAINLEN+1];
 827         char clientip_buf[128];
 828         char rcode_buf[16];
 829         char type_buf[16];
 830         char class_buf[16];
 831         size_t pktlen;
 832         uint16_t rcode = FLAGS_GET_RCODE(sldns_buffer_read_u16_at(rmsg, 2));
 833
 834         if(verbosity < v)
 835           return;
 836
 837         sldns_wire2str_rcode_buf((int)rcode, rcode_buf, sizeof(rcode_buf));
 838         addr_to_str(addr, addrlen, clientip_buf, sizeof(clientip_buf));
 839         if(rcode == LDNS_RCODE_FORMERR)
 840         {
 841                 log_info("%s - - - %s - - - ", clientip_buf, rcode_buf);
 842         } else {
 843                 dname_str(qinf->qname, qname_buf);
 844                 pktlen = sldns_buffer_limit(rmsg);
 845                 sldns_wire2str_type_buf(qinf->qtype, type_buf, sizeof(type_buf));
 846                 sldns_wire2str_class_buf(qinf->qclass, class_buf, sizeof(class_buf));
 847                 log_info("%s %s %s %s %s " ARG_LL "d.%6.6d %d %d",
 848                         clientip_buf, qname_buf, type_buf, class_buf,
 849                         rcode_buf, (long long)dur.tv_sec, (int)dur.tv_usec, cached, (int)pktlen);
 850         }
 851 }
 852
 853 void
 854 log_query_info(enum verbosity_value v, const char* str,
 855         struct query_info* qinf)
 856 {
 857         log_nametypeclass(v, str, qinf->qname, qinf->qtype, qinf->qclass);
 858 }
 859
 860 int
 861 reply_check_cname_chain(struct query_info* qinfo, struct reply_info* rep)
 862 {
 863         /* check only answer section rrs for matching cname chain.
 864          * the cache may return changed rdata, but owner names are untouched.*/
 865         size_t i;
 866         uint8_t* sname = qinfo->qname;
 867         size_t snamelen = qinfo->qname_len;
 868         for(i=0; i<rep->an_numrrsets; i++) {
 869                 uint16_t t = ntohs(rep->rrsets[i]->rk.type);
 870                 if(t == LDNS_RR_TYPE_DNAME)
 871                         continue; /* skip dnames; note TTL 0 not cached */
 872                 /* verify that owner matches current sname */
 873                 if(query_dname_compare(sname, rep->rrsets[i]->rk.dname) != 0){
 874                         /* cname chain broken */
 875                         return 0;
 876                 }
 877                 /* if this is a cname; move on */
 878                 if(t == LDNS_RR_TYPE_CNAME) {
 879                         get_cname_target(rep->rrsets[i], &sname, &snamelen);
 880                 }
 881         }
 882         return 1;
 883 }
 884
 885 int
 886 reply_all_rrsets_secure(struct reply_info* rep)
 887 {
 888         size_t i;
 889         for(i=0; i<rep->rrset_count; i++) {
 890                 if( ((struct packed_rrset_data*)rep->rrsets[i]->entry.data)
 891                         ->security != sec_status_secure )
 892                 return 0;
 893         }
 894         return 1;
 895 }
 896
 897 int edns_opt_append(struct edns_data* edns, struct regional* region,
 898         uint16_t code, size_t len, uint8_t* data)
 899 {
 900         struct edns_option** prevp;
 901         struct edns_option* opt;
 902
 903         /* allocate new element */
 904         opt = (struct edns_option*)regional_alloc(region, sizeof(*opt));
 905         if(!opt)
 906                 return 0;
 907         opt->next = NULL;
 908         opt->opt_code = code;
 909         opt->opt_len = len;
 910         opt->opt_data = NULL;
 911         if(len > 0) {
 912                 opt->opt_data = regional_alloc_init(region, data, len);
 913                 if(!opt->opt_data)
 914                         return 0;
 915         }
 916
 917         /* append at end of list */
 918         prevp = &edns->opt_list;
 919         while(*prevp != NULL)
 920                 prevp = &((*prevp)->next);
 921         *prevp = opt;
 922         return 1;
 923 }
 924
 925 int edns_opt_list_append(struct edns_option** list, uint16_t code, size_t len,
 926         uint8_t* data, struct regional* region)
 927 {
 928         struct edns_option** prevp;
 929         struct edns_option* opt;
 930
 931         /* allocate new element */
 932         opt = (struct edns_option*)regional_alloc(region, sizeof(*opt));
 933         if(!opt)
 934                 return 0;
 935         opt->next = NULL;
 936         opt->opt_code = code;
 937         opt->opt_len = len;
 938         opt->opt_data = NULL;
 939         if(len > 0) {
 940                 opt->opt_data = regional_alloc_init(region, data, len);
 941                 if(!opt->opt_data)
 942                         return 0;
 943         }
 944
 945         /* append at end of list */
 946         prevp = list;
 947         while(*prevp != NULL) {
 948                 prevp = &((*prevp)->next);
 949         }
 950         *prevp = opt;
 951         return 1;
 952 }
 953
 954 int edns_opt_list_remove(struct edns_option** list, uint16_t code)
 955 {
 956         /* The list should already be allocated in a region. Freeing the
 957          * allocated space in a region is not possible. We just unlink the
 958          * required elements and they will be freed together with the region. */
 959
 960         struct edns_option* prev;
 961         struct edns_option* curr;
 962         if(!list || !(*list)) return 0;
 963
 964         /* Unlink and repoint if the element(s) are first in list */
 965         while(list && *list && (*list)->opt_code == code) {
 966                 *list = (*list)->next;
 967         }
 968
 969         if(!list || !(*list)) return 1;
 970         /* Unlink elements and reattach the list */
 971         prev = *list;
 972         curr = (*list)->next;
 973         while(curr != NULL) {
 974                 if(curr->opt_code == code) {
 975                         prev->next = curr->next;
 976                         curr = curr->next;
 977                 } else {
 978                         prev = curr;
 979                         curr = curr->next;
 980                 }
 981         }
 982         return 1;
 983 }
 984
 985 static int inplace_cb_reply_call_generic(
 986     struct inplace_cb* callback_list, enum inplace_cb_list_type type,
 987         struct query_info* qinfo, struct module_qstate* qstate,
 988         struct reply_info* rep, int rcode, struct edns_data* edns,
 989         struct regional* region)
 990 {
 991         struct inplace_cb* cb;
 992         struct edns_option* opt_list_out = NULL;
 993         if(qstate)
 994                 opt_list_out = qstate->edns_opts_front_out;
 995         for(cb=callback_list; cb; cb=cb->next) {
 996                 fptr_ok(fptr_whitelist_inplace_cb_reply_generic(
 997                         (inplace_cb_reply_func_type*)cb->cb, type));
 998                 (void)(*(inplace_cb_reply_func_type*)cb->cb)(qinfo, qstate, rep,
 999                         rcode, edns, &opt_list_out, region, cb->id, cb->cb_arg);
1000         }
1001         edns->opt_list = opt_list_out;
1002         return 1;
1003 }
1004
1005 int inplace_cb_reply_call(struct module_env* env, struct query_info* qinfo,
1006         struct module_qstate* qstate, struct reply_info* rep, int rcode,
1007         struct edns_data* edns, struct regional* region)
1008 {
1009         return inplace_cb_reply_call_generic(
1010                 env->inplace_cb_lists[inplace_cb_reply], inplace_cb_reply, qinfo,
1011                 qstate, rep, rcode, edns, region);
1012 }
1013
1014 int inplace_cb_reply_cache_call(struct module_env* env,
1015         struct query_info* qinfo, struct module_qstate* qstate,
1016         struct reply_info* rep, int rcode, struct edns_data* edns,
1017         struct regional* region)
1018 {
1019         return inplace_cb_reply_call_generic(
1020                 env->inplace_cb_lists[inplace_cb_reply_cache], inplace_cb_reply_cache,
1021                 qinfo, qstate, rep, rcode, edns, region);
1022 }
1023
1024 int inplace_cb_reply_local_call(struct module_env* env,
1025         struct query_info* qinfo, struct module_qstate* qstate,
1026         struct reply_info* rep, int rcode, struct edns_data* edns,
1027         struct regional* region)
1028 {
1029         return inplace_cb_reply_call_generic(
1030                 env->inplace_cb_lists[inplace_cb_reply_local], inplace_cb_reply_local,
1031                 qinfo, qstate, rep, rcode, edns, region);
1032 }
1033
1034 int inplace_cb_reply_servfail_call(struct module_env* env,
1035         struct query_info* qinfo, struct module_qstate* qstate,
1036         struct reply_info* rep, int rcode, struct edns_data* edns,
1037         struct regional* region)
1038 {
1039         /* We are going to servfail. Remove any potential edns options. */
1040         if(qstate)
1041                 qstate->edns_opts_front_out = NULL;
1042         return inplace_cb_reply_call_generic(
1043                 env->inplace_cb_lists[inplace_cb_reply_servfail],
1044                 inplace_cb_reply_servfail, qinfo, qstate, rep, rcode, edns, region);
1045 }
1046
1047 int inplace_cb_query_call(struct module_env* env, struct query_info* qinfo,
1048         uint16_t flags, struct sockaddr_storage* addr, socklen_t addrlen,
1049         uint8_t* zone, size_t zonelen, struct module_qstate* qstate,
1050         struct regional* region)
1051 {
1052         struct inplace_cb* cb = env->inplace_cb_lists[inplace_cb_query];
1053         for(; cb; cb=cb->next) {
1054                 fptr_ok(fptr_whitelist_inplace_cb_query(
1055                         (inplace_cb_query_func_type*)cb->cb));
1056                 (void)(*(inplace_cb_query_func_type*)cb->cb)(qinfo, flags,
1057                         qstate, addr, addrlen, zone, zonelen, region,
1058                         cb->id, cb->cb_arg);
1059         }
1060         return 1;
1061 }
1062
1063 int inplace_cb_edns_back_parsed_call(struct module_env* env,
1064         struct module_qstate* qstate)
1065 {
1066         struct inplace_cb* cb =
1067                 env->inplace_cb_lists[inplace_cb_edns_back_parsed];
1068         for(; cb; cb=cb->next) {
1069                 fptr_ok(fptr_whitelist_inplace_cb_edns_back_parsed(
1070                         (inplace_cb_edns_back_parsed_func_type*)cb->cb));
1071                 (void)(*(inplace_cb_edns_back_parsed_func_type*)cb->cb)(qstate,
1072                         cb->id, cb->cb_arg);
1073         }
1074         return 1;
1075 }
1076
1077 int inplace_cb_query_response_call(struct module_env* env,
1078         struct module_qstate* qstate, struct dns_msg* response) {
1079         struct inplace_cb* cb =
1080                 env->inplace_cb_lists[inplace_cb_query_response];
1081         for(; cb; cb=cb->next) {
1082                 fptr_ok(fptr_whitelist_inplace_cb_query_response(
1083                         (inplace_cb_query_response_func_type*)cb->cb));
1084                 (void)(*(inplace_cb_query_response_func_type*)cb->cb)(qstate,
1085                         response, cb->id, cb->cb_arg);
1086         }
1087         return 1;
1088 }
1089
1090 struct edns_option* edns_opt_copy_region(struct edns_option* list,
1091         struct regional* region)
1092 {
1093         struct edns_option* result = NULL, *cur = NULL, *s;
1094         while(list) {
1095                 /* copy edns option structure */
1096                 s = regional_alloc_init(region, list, sizeof(*list));
1097                 if(!s) return NULL;
1098                 s->next = NULL;
1099
1100                 /* copy option data */
1101                 if(s->opt_data) {
1102                         s->opt_data = regional_alloc_init(region, s->opt_data,
1103                                 s->opt_len);
1104                         if(!s->opt_data)
1105                                 return NULL;
1106                 }
1107
1108                 /* link into list */
1109                 if(cur)
1110                         cur->next = s;
1111                 else    result = s;
1112                 cur = s;
1113
1114                 /* examine next element */
1115                 list = list->next;
1116         }
1117         return result;
1118 }
1119
1120 int edns_opt_compare(struct edns_option* p, struct edns_option* q)
1121 {
1122         if(!p && !q) return 0;
1123         if(!p) return -1;
1124         if(!q) return 1;
1125         log_assert(p && q);
1126         if(p->opt_code != q->opt_code)
1127                 return (int)q->opt_code - (int)p->opt_code;
1128         if(p->opt_len != q->opt_len)
1129                 return (int)q->opt_len - (int)p->opt_len;
1130         if(p->opt_len != 0)
1131                 return memcmp(p->opt_data, q->opt_data, p->opt_len);
1132         return 0;
1133 }
1134
1135 int edns_opt_list_compare(struct edns_option* p, struct edns_option* q)
1136 {
1137         int r;
1138         while(p && q) {
1139                 r = edns_opt_compare(p, q);
1140                 if(r != 0)
1141                         return r;
1142                 p = p->next;
1143                 q = q->next;
1144         }
1145         if(p || q) {
1146                 /* uneven length lists */
1147                 if(p) return 1;
1148                 if(q) return -1;
1149         }
1150         return 0;
1151 }
1152
1153 void edns_opt_list_free(struct edns_option* list)
1154 {
1155         struct edns_option* n;
1156         while(list) {
1157                 free(list->opt_data);
1158                 n = list->next;
1159                 free(list);
1160                 list = n;
1161         }
1162 }
1163
1164 struct edns_option* edns_opt_copy_alloc(struct edns_option* list)
1165 {
1166         struct edns_option* result = NULL, *cur = NULL, *s;
1167         while(list) {
1168                 /* copy edns option structure */
1169                 s = memdup(list, sizeof(*list));
1170                 if(!s) {
1171                         edns_opt_list_free(result);
1172                         return NULL;
1173                 }
1174                 s->next = NULL;
1175
1176                 /* copy option data */
1177                 if(s->opt_data) {
1178                         s->opt_data = memdup(s->opt_data, s->opt_len);
1179                         if(!s->opt_data) {
1180                                 free(s);
1181                                 edns_opt_list_free(result);
1182                                 return NULL;
1183                         }
1184                 }
1185
1186                 /* link into list */
1187                 if(cur)
1188                         cur->next = s;
1189                 else    result = s;
1190                 cur = s;
1191
1192                 /* examine next element */
1193                 list = list->next;
1194         }
1195         return result;
1196 }
1197
1198 struct edns_option* edns_opt_list_find(struct edns_option* list, uint16_t code)
1199 {
1200         struct edns_option* p;
1201         for(p=list; p; p=p->next) {
1202                 if(p->opt_code == code)
1203                         return p;
1204         }
1205         return NULL;
1206 }