git.meshlink.io Git - catta/blob - avahi-core/dns.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of avahi.
   5
   6   avahi is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as
   8   published by the Free Software Foundation; either version 2.1 of the
   9   License, or (at your option) any later version.
  10
  11   avahi is distributed in the hope that it will be useful, but WITHOUT
  12   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13   or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
  14   Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with avahi; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <netinet/in.h>
  27
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <stdio.h>
  31 #include <assert.h>
  32
  33 #include <avahi-common/domain.h>
  34 #include <avahi-common/malloc.h>
  35
  36 #include "dns.h"
  37 #include "log.h"
  38
  39 AvahiDnsPacket* avahi_dns_packet_new(unsigned mtu) {
  40     AvahiDnsPacket *p;
  41     size_t max_size;
  42
  43     if (mtu <= 0)
  44         max_size = AVAHI_DNS_PACKET_SIZE_MAX;
  45     else if (mtu >= AVAHI_DNS_PACKET_EXTRA_SIZE)
  46         max_size = mtu - AVAHI_DNS_PACKET_EXTRA_SIZE;
  47     else
  48         max_size = 0;
  49
  50     if (max_size < AVAHI_DNS_PACKET_HEADER_SIZE)
  51         max_size = AVAHI_DNS_PACKET_HEADER_SIZE;
  52
  53     if (!(p = avahi_malloc(sizeof(AvahiDnsPacket) + max_size)))
  54         return p;
  55
  56     p->size = p->rindex = AVAHI_DNS_PACKET_HEADER_SIZE;
  57     p->max_size = max_size;
  58     p->name_table = NULL;
  59     p->data = NULL;
  60
  61     memset(AVAHI_DNS_PACKET_DATA(p), 0, p->size);
  62     return p;
  63 }
  64
  65 AvahiDnsPacket* avahi_dns_packet_new_query(unsigned mtu) {
  66     AvahiDnsPacket *p;
  67
  68     if (!(p = avahi_dns_packet_new(mtu)))
  69         return NULL;
  70
  71     avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_FLAGS, AVAHI_DNS_FLAGS(0, 0, 0, 0, 0, 0, 0, 0, 0, 0));
  72     return p;
  73 }
  74
  75 AvahiDnsPacket* avahi_dns_packet_new_response(unsigned mtu, int aa) {
  76     AvahiDnsPacket *p;
  77
  78     if (!(p = avahi_dns_packet_new(mtu)))
  79         return NULL;
  80
  81     avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_FLAGS, AVAHI_DNS_FLAGS(1, 0, aa, 0, 0, 0, 0, 0, 0, 0));
  82     return p;
  83 }
  84
  85 AvahiDnsPacket* avahi_dns_packet_new_reply(AvahiDnsPacket* p, unsigned mtu, int copy_queries, int aa) {
  86     AvahiDnsPacket *r;
  87     assert(p);
  88
  89     if (!(r = avahi_dns_packet_new_response(mtu, aa)))
  90         return NULL;
  91
  92     if (copy_queries) {
  93         unsigned saved_rindex;
  94         uint32_t n;
  95
  96         saved_rindex = p->rindex;
  97         p->rindex = AVAHI_DNS_PACKET_HEADER_SIZE;
  98
  99         for (n = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_QDCOUNT); n > 0; n--) {
 100             AvahiKey *k;
 101             int unicast_response;
 102
 103             if ((k = avahi_dns_packet_consume_key(p, &unicast_response))) {
 104                 avahi_dns_packet_append_key(r, k, unicast_response);
 105                 avahi_key_unref(k);
 106             }
 107         }
 108
 109         p->rindex = saved_rindex;
 110
 111         avahi_dns_packet_set_field(r, AVAHI_DNS_FIELD_QDCOUNT, avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_QDCOUNT));
 112     }
 113
 114     avahi_dns_packet_set_field(r, AVAHI_DNS_FIELD_ID, avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ID));
 115
 116     avahi_dns_packet_set_field(r, AVAHI_DNS_FIELD_FLAGS,
 117                                (avahi_dns_packet_get_field(r, AVAHI_DNS_FIELD_FLAGS) & ~AVAHI_DNS_FLAG_OPCODE) |
 118                                (avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS) & AVAHI_DNS_FLAG_OPCODE));
 119
 120     return r;
 121 }
 122
 123
 124 void avahi_dns_packet_free(AvahiDnsPacket *p) {
 125     assert(p);
 126
 127     if (p->name_table)
 128         avahi_hashmap_free(p->name_table);
 129
 130     avahi_free(p);
 131 }
 132
 133 void avahi_dns_packet_set_field(AvahiDnsPacket *p, unsigned idx, uint16_t v) {
 134     assert(p);
 135     assert(idx < AVAHI_DNS_PACKET_HEADER_SIZE);
 136
 137     ((uint16_t*) AVAHI_DNS_PACKET_DATA(p))[idx] = htons(v);
 138 }
 139
 140 uint16_t avahi_dns_packet_get_field(AvahiDnsPacket *p, unsigned idx) {
 141     assert(p);
 142     assert(idx < AVAHI_DNS_PACKET_HEADER_SIZE);
 143
 144     return ntohs(((uint16_t*) AVAHI_DNS_PACKET_DATA(p))[idx]);
 145 }
 146
 147 void avahi_dns_packet_inc_field(AvahiDnsPacket *p, unsigned idx) {
 148     assert(p);
 149     assert(idx < AVAHI_DNS_PACKET_HEADER_SIZE);
 150
 151     avahi_dns_packet_set_field(p, idx, avahi_dns_packet_get_field(p, idx) + 1);
 152 }
 153
 154 uint8_t* avahi_dns_packet_append_name(AvahiDnsPacket *p, const char *name) {
 155     uint8_t *d, *saved_ptr = NULL;
 156     size_t saved_size;
 157
 158     assert(p);
 159     assert(name);
 160
 161     saved_size = p->size;
 162     saved_ptr = avahi_dns_packet_extend(p, 0);
 163
 164     while (*name) {
 165         uint8_t* prev;
 166         const char *pname;
 167         char label[64], *u;
 168
 169         /* Check whether we can compress this name. */
 170
 171         if (p->name_table && (prev = avahi_hashmap_lookup(p->name_table, name))) {
 172             unsigned idx;
 173
 174             assert(prev >= AVAHI_DNS_PACKET_DATA(p));
 175             idx = (unsigned) (prev - AVAHI_DNS_PACKET_DATA(p));
 176
 177             assert(idx < p->size);
 178
 179             if (idx < 0x4000) {
 180                 uint8_t *t;
 181                 if (!(t = (uint8_t*) avahi_dns_packet_extend(p, sizeof(uint16_t))))
 182                     return NULL;
 183
 184                 t[0] = (uint8_t) ((0xC000 | idx) >> 8);
 185                 t[1] = (uint8_t) idx;
 186                 return saved_ptr;
 187             }
 188         }
 189
 190         pname = name;
 191
 192         if (!(avahi_unescape_label(&name, label, sizeof(label))))
 193             goto fail;
 194
 195         if (!(d = avahi_dns_packet_append_string(p, label)))
 196             goto fail;
 197
 198         if (!p->name_table)
 199             /* This works only for normalized domain names */
 200             p->name_table = avahi_hashmap_new(avahi_string_hash, avahi_string_equal, avahi_free, NULL);
 201
 202         if (!(u = avahi_strdup(pname)))
 203             avahi_log_error("avahi_strdup() failed.");
 204         else
 205             avahi_hashmap_insert(p->name_table, u, d);
 206     }
 207
 208     if (!(d = avahi_dns_packet_extend(p, 1)))
 209         goto fail;
 210
 211     *d = 0;
 212
 213     return saved_ptr;
 214
 215 fail:
 216     p->size = saved_size;
 217     return NULL;
 218 }
 219
 220 uint8_t* avahi_dns_packet_append_uint16(AvahiDnsPacket *p, uint16_t v) {
 221     uint8_t *d;
 222     assert(p);
 223
 224     if (!(d = avahi_dns_packet_extend(p, sizeof(uint16_t))))
 225         return NULL;
 226
 227     d[0] = (uint8_t) (v >> 8);
 228     d[1] = (uint8_t) v;
 229     return d;
 230 }
 231
 232 uint8_t *avahi_dns_packet_append_uint32(AvahiDnsPacket *p, uint32_t v) {
 233     uint8_t *d;
 234     assert(p);
 235
 236     if (!(d = avahi_dns_packet_extend(p, sizeof(uint32_t))))
 237         return NULL;
 238
 239     d[0] = (uint8_t) (v >> 24);
 240     d[1] = (uint8_t) (v >> 16);
 241     d[2] = (uint8_t) (v >> 8);
 242     d[3] = (uint8_t) v;
 243
 244     return d;
 245 }
 246
 247 uint8_t *avahi_dns_packet_append_bytes(AvahiDnsPacket  *p, const void *b, size_t l) {
 248     uint8_t* d;
 249
 250     assert(p);
 251     assert(b);
 252     assert(l);
 253
 254     if (!(d = avahi_dns_packet_extend(p, l)))
 255         return NULL;
 256
 257     memcpy(d, b, l);
 258     return d;
 259 }
 260
 261 uint8_t* avahi_dns_packet_append_string(AvahiDnsPacket *p, const char *s) {
 262     uint8_t* d;
 263     size_t k;
 264
 265     assert(p);
 266     assert(s);
 267
 268     if ((k = strlen(s)) >= 255)
 269         k = 255;
 270
 271     if (!(d = avahi_dns_packet_extend(p, k+1)))
 272         return NULL;
 273
 274     *d = (uint8_t) k;
 275     memcpy(d+1, s, k);
 276
 277     return d;
 278 }
 279
 280 uint8_t *avahi_dns_packet_extend(AvahiDnsPacket *p, size_t l) {
 281     uint8_t *d;
 282
 283     assert(p);
 284
 285     if (p->size+l > p->max_size)
 286         return NULL;
 287
 288     d = AVAHI_DNS_PACKET_DATA(p) + p->size;
 289     p->size += l;
 290
 291     return d;
 292 }
 293
 294 int avahi_dns_packet_check_valid(AvahiDnsPacket *p) {
 295     uint16_t flags;
 296     assert(p);
 297
 298     if (p->size < AVAHI_DNS_PACKET_HEADER_SIZE)
 299         return -1;
 300
 301     flags = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS);
 302
 303     if (flags & AVAHI_DNS_FLAG_OPCODE)
 304         return -1;
 305
 306     return 0;
 307 }
 308
 309 int avahi_dns_packet_check_valid_multicast(AvahiDnsPacket *p) {
 310     uint16_t flags;
 311     assert(p);
 312
 313     if (avahi_dns_packet_check_valid(p) < 0)
 314         return -1;
 315
 316     flags = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS);
 317
 318     if (flags & AVAHI_DNS_FLAG_RCODE)
 319         return -1;
 320
 321     return 0;
 322 }
 323
 324
 325 int avahi_dns_packet_is_query(AvahiDnsPacket *p) {
 326     assert(p);
 327
 328     return !(avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS) & AVAHI_DNS_FLAG_QR);
 329 }
 330
 331 static int consume_labels(AvahiDnsPacket *p, unsigned idx, char *ret_name, size_t l) {
 332     int ret = 0;
 333     int compressed = 0;
 334     int first_label = 1;
 335     assert(p && ret_name && l);
 336
 337     for (;;) {
 338         uint8_t n;
 339
 340         if (idx+1 > p->size)
 341             return -1;
 342
 343         n = AVAHI_DNS_PACKET_DATA(p)[idx];
 344
 345         if (!n) {
 346             idx++;
 347             if (!compressed)
 348                 ret++;
 349
 350             if (l < 1)
 351                 return -1;
 352             *ret_name = 0;
 353
 354             return ret;
 355
 356         } else if (n <= 63) {
 357             /* Uncompressed label */
 358             idx++;
 359             if (!compressed)
 360                 ret++;
 361
 362             if (idx + n > p->size)
 363                 return -1;
 364
 365             if ((size_t) n + 1 > l)
 366                 return -1;
 367
 368             if (!first_label) {
 369                 *(ret_name++) = '.';
 370                 l--;
 371             } else
 372                 first_label = 0;
 373
 374             if (!(avahi_escape_label((char*) AVAHI_DNS_PACKET_DATA(p) + idx, n, &ret_name, &l)))
 375                 return -1;
 376
 377             idx += n;
 378
 379             if (!compressed)
 380                 ret += n;
 381         } else if ((n & 0xC0) == 0xC0) {
 382             /* Compressed label */
 383
 384             if (idx+2 > p->size)
 385                 return -1;
 386
 387             idx = ((unsigned) (AVAHI_DNS_PACKET_DATA(p)[idx] & ~0xC0)) << 8 | AVAHI_DNS_PACKET_DATA(p)[idx+1];
 388
 389             if (!compressed)
 390                 ret += 2;
 391
 392             compressed = 1;
 393         } else
 394             return -1;
 395     }
 396 }
 397
 398 int avahi_dns_packet_consume_name(AvahiDnsPacket *p, char *ret_name, size_t l) {
 399     int r;
 400
 401     if ((r = consume_labels(p, p->rindex, ret_name, l)) < 0)
 402         return -1;
 403
 404     p->rindex += r;
 405     return 0;
 406 }
 407
 408 int avahi_dns_packet_consume_uint16(AvahiDnsPacket *p, uint16_t *ret_v) {
 409     uint8_t *d;
 410
 411     assert(p);
 412     assert(ret_v);
 413
 414     if (p->rindex + sizeof(uint16_t) > p->size)
 415         return -1;
 416
 417     d = (uint8_t*) (AVAHI_DNS_PACKET_DATA(p) + p->rindex);
 418     *ret_v = (d[0] << 8) | d[1];
 419     p->rindex += sizeof(uint16_t);
 420
 421     return 0;
 422 }
 423
 424 int avahi_dns_packet_consume_uint32(AvahiDnsPacket *p, uint32_t *ret_v) {
 425     uint8_t* d;
 426
 427     assert(p);
 428     assert(ret_v);
 429
 430     if (p->rindex + sizeof(uint32_t) > p->size)
 431         return -1;
 432
 433     d = (uint8_t*) (AVAHI_DNS_PACKET_DATA(p) + p->rindex);
 434     *ret_v = (d[0] << 24) | (d[1] << 16) | (d[2] << 8) | d[3];
 435     p->rindex += sizeof(uint32_t);
 436
 437     return 0;
 438 }
 439
 440 int avahi_dns_packet_consume_bytes(AvahiDnsPacket *p, void * ret_data, size_t l) {
 441     assert(p);
 442     assert(ret_data);
 443     assert(l > 0);
 444
 445     if (p->rindex + l > p->size)
 446         return -1;
 447
 448     memcpy(ret_data, AVAHI_DNS_PACKET_DATA(p) + p->rindex, l);
 449     p->rindex += l;
 450
 451     return 0;
 452 }
 453
 454 int avahi_dns_packet_consume_string(AvahiDnsPacket *p, char *ret_string, size_t l) {
 455     size_t k;
 456
 457     assert(p);
 458     assert(ret_string);
 459     assert(l > 0);
 460
 461     if (p->rindex >= p->size)
 462         return -1;
 463
 464     k = AVAHI_DNS_PACKET_DATA(p)[p->rindex];
 465
 466     if (p->rindex+1+k > p->size)
 467         return -1;
 468
 469     if (l > k+1)
 470         l = k+1;
 471
 472     memcpy(ret_string, AVAHI_DNS_PACKET_DATA(p)+p->rindex+1, l-1);
 473     ret_string[l-1] = 0;
 474
 475     p->rindex += 1+k;
 476
 477     return 0;
 478 }
 479
 480 const void* avahi_dns_packet_get_rptr(AvahiDnsPacket *p) {
 481     assert(p);
 482
 483     if (p->rindex > p->size)
 484         return NULL;
 485
 486     return AVAHI_DNS_PACKET_DATA(p) + p->rindex;
 487 }
 488
 489 int avahi_dns_packet_skip(AvahiDnsPacket *p, size_t length) {
 490     assert(p);
 491
 492     if (p->rindex + length > p->size)
 493         return -1;
 494
 495     p->rindex += length;
 496     return 0;
 497 }
 498
 499 static int parse_rdata(AvahiDnsPacket *p, AvahiRecord *r, uint16_t rdlength) {
 500     char buf[AVAHI_DOMAIN_NAME_MAX];
 501     const void* start;
 502
 503     assert(p);
 504     assert(r);
 505
 506     start = avahi_dns_packet_get_rptr(p);
 507
 508     switch (r->key->type) {
 509         case AVAHI_DNS_TYPE_PTR:
 510         case AVAHI_DNS_TYPE_CNAME:
 511         case AVAHI_DNS_TYPE_NS:
 512
 513             if (avahi_dns_packet_consume_name(p, buf, sizeof(buf)) < 0)
 514                 return -1;
 515
 516             r->data.ptr.name = avahi_strdup(buf);
 517             break;
 518
 519
 520         case AVAHI_DNS_TYPE_SRV:
 521
 522             if (avahi_dns_packet_consume_uint16(p, &r->data.srv.priority) < 0 ||
 523                 avahi_dns_packet_consume_uint16(p, &r->data.srv.weight) < 0 ||
 524                 avahi_dns_packet_consume_uint16(p, &r->data.srv.port) < 0 ||
 525                 avahi_dns_packet_consume_name(p, buf, sizeof(buf)) < 0)
 526                 return -1;
 527
 528             r->data.srv.name = avahi_strdup(buf);
 529             break;
 530
 531         case AVAHI_DNS_TYPE_HINFO:
 532
 533             if (avahi_dns_packet_consume_string(p, buf, sizeof(buf)) < 0)
 534                 return -1;
 535
 536             r->data.hinfo.cpu = avahi_strdup(buf);
 537
 538             if (avahi_dns_packet_consume_string(p, buf, sizeof(buf)) < 0)
 539                 return -1;
 540
 541             r->data.hinfo.os = avahi_strdup(buf);
 542             break;
 543
 544         case AVAHI_DNS_TYPE_TXT:
 545
 546             if (rdlength > 0) {
 547                 if (avahi_string_list_parse(avahi_dns_packet_get_rptr(p), rdlength, &r->data.txt.string_list) < 0)
 548                     return -1;
 549
 550                 if (avahi_dns_packet_skip(p, rdlength) < 0)
 551                     return -1;
 552             } else
 553                 r->data.txt.string_list = NULL;
 554
 555             break;
 556
 557         case AVAHI_DNS_TYPE_A:
 558
 559 /*             avahi_log_debug("A"); */
 560
 561             if (avahi_dns_packet_consume_bytes(p, &r->data.a.address, sizeof(AvahiIPv4Address)) < 0)
 562                 return -1;
 563
 564             break;
 565
 566         case AVAHI_DNS_TYPE_AAAA:
 567
 568 /*             avahi_log_debug("aaaa"); */
 569
 570             if (avahi_dns_packet_consume_bytes(p, &r->data.aaaa.address, sizeof(AvahiIPv6Address)) < 0)
 571                 return -1;
 572
 573             break;
 574
 575         default:
 576
 577 /*             avahi_log_debug("generic"); */
 578
 579             if (rdlength > 0) {
 580
 581                 r->data.generic.data = avahi_memdup(avahi_dns_packet_get_rptr(p), rdlength);
 582
 583                 if (avahi_dns_packet_skip(p, rdlength) < 0)
 584                     return -1;
 585             }
 586
 587             break;
 588     }
 589
 590     /* Check if we read enough data */
 591     if ((const uint8_t*) avahi_dns_packet_get_rptr(p) - (const uint8_t*) start != rdlength)
 592         return -1;
 593
 594     return 0;
 595 }
 596
 597 AvahiRecord* avahi_dns_packet_consume_record(AvahiDnsPacket *p, int *ret_cache_flush) {
 598     char name[AVAHI_DOMAIN_NAME_MAX];
 599     uint16_t type, class;
 600     uint32_t ttl;
 601     uint16_t rdlength;
 602     AvahiRecord *r = NULL;
 603
 604     assert(p);
 605
 606     if (avahi_dns_packet_consume_name(p, name, sizeof(name)) < 0 ||
 607         avahi_dns_packet_consume_uint16(p, &type) < 0 ||
 608         avahi_dns_packet_consume_uint16(p, &class) < 0 ||
 609         avahi_dns_packet_consume_uint32(p, &ttl) < 0 ||
 610         avahi_dns_packet_consume_uint16(p, &rdlength) < 0 ||
 611         p->rindex + rdlength > p->size)
 612         goto fail;
 613
 614     if (ret_cache_flush)
 615         *ret_cache_flush = !!(class & AVAHI_DNS_CACHE_FLUSH);
 616     class &= ~AVAHI_DNS_CACHE_FLUSH;
 617
 618     if (!(r = avahi_record_new_full(name, class, type, ttl)))
 619         goto fail;
 620
 621     if (parse_rdata(p, r, rdlength) < 0)
 622         goto fail;
 623
 624     return r;
 625
 626 fail:
 627     if (r)
 628         avahi_record_unref(r);
 629
 630     return NULL;
 631 }
 632
 633 AvahiKey* avahi_dns_packet_consume_key(AvahiDnsPacket *p, int *ret_unicast_response) {
 634     char name[256];
 635     uint16_t type, class;
 636
 637     assert(p);
 638
 639     if (avahi_dns_packet_consume_name(p, name, sizeof(name)) < 0 ||
 640         avahi_dns_packet_consume_uint16(p, &type) < 0 ||
 641         avahi_dns_packet_consume_uint16(p, &class) < 0)
 642         return NULL;
 643
 644     if (ret_unicast_response)
 645         *ret_unicast_response = !!(class & AVAHI_DNS_UNICAST_RESPONSE);
 646
 647     class &= ~AVAHI_DNS_UNICAST_RESPONSE;
 648
 649     return avahi_key_new(name, class, type);
 650 }
 651
 652 uint8_t* avahi_dns_packet_append_key(AvahiDnsPacket *p, AvahiKey *k, int unicast_response) {
 653     uint8_t *t;
 654     size_t size;
 655
 656     assert(p);
 657     assert(k);
 658
 659     size = p->size;
 660
 661     if (!(t = avahi_dns_packet_append_name(p, k->name)) ||
 662         !avahi_dns_packet_append_uint16(p, k->type) ||
 663         !avahi_dns_packet_append_uint16(p, k->clazz | (unicast_response ? AVAHI_DNS_UNICAST_RESPONSE : 0))) {
 664         p->size = size;
 665         return NULL;
 666     }
 667
 668     return t;
 669 }
 670
 671 static int append_rdata(AvahiDnsPacket *p, AvahiRecord *r) {
 672     assert(p);
 673     assert(r);
 674
 675     switch (r->key->type) {
 676
 677         case AVAHI_DNS_TYPE_PTR:
 678         case AVAHI_DNS_TYPE_CNAME:
 679         case AVAHI_DNS_TYPE_NS:
 680
 681             if (!(avahi_dns_packet_append_name(p, r->data.ptr.name)))
 682                 return -1;
 683
 684             break;
 685
 686         case AVAHI_DNS_TYPE_SRV:
 687
 688             if (!avahi_dns_packet_append_uint16(p, r->data.srv.priority) ||
 689                 !avahi_dns_packet_append_uint16(p, r->data.srv.weight) ||
 690                 !avahi_dns_packet_append_uint16(p, r->data.srv.port) ||
 691                 !avahi_dns_packet_append_name(p, r->data.srv.name))
 692                 return -1;
 693
 694             break;
 695
 696         case AVAHI_DNS_TYPE_HINFO:
 697             if (!avahi_dns_packet_append_string(p, r->data.hinfo.cpu) ||
 698                 !avahi_dns_packet_append_string(p, r->data.hinfo.os))
 699                 return -1;
 700
 701             break;
 702
 703         case AVAHI_DNS_TYPE_TXT: {
 704
 705             uint8_t *data;
 706             size_t n;
 707
 708             n = avahi_string_list_serialize(r->data.txt.string_list, NULL, 0);
 709
 710             if (!(data = avahi_dns_packet_extend(p, n)))
 711                 return -1;
 712
 713             avahi_string_list_serialize(r->data.txt.string_list, data, n);
 714             break;
 715         }
 716
 717
 718         case AVAHI_DNS_TYPE_A:
 719
 720             if (!avahi_dns_packet_append_bytes(p, &r->data.a.address, sizeof(r->data.a.address)))
 721                 return -1;
 722
 723             break;
 724
 725         case AVAHI_DNS_TYPE_AAAA:
 726
 727             if (!avahi_dns_packet_append_bytes(p, &r->data.aaaa.address, sizeof(r->data.aaaa.address)))
 728                 return -1;
 729
 730             break;
 731
 732         default:
 733
 734             if (r->data.generic.size)
 735                 if (avahi_dns_packet_append_bytes(p, r->data.generic.data, r->data.generic.size))
 736                     return -1;
 737
 738             break;
 739     }
 740
 741     return 0;
 742 }
 743
 744
 745 uint8_t* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, int cache_flush, unsigned max_ttl) {
 746     uint8_t *t, *l, *start;
 747     size_t size;
 748
 749     assert(p);
 750     assert(r);
 751
 752     size = p->size;
 753
 754     if (!(t = avahi_dns_packet_append_name(p, r->key->name)) ||
 755         !avahi_dns_packet_append_uint16(p, r->key->type) ||
 756         !avahi_dns_packet_append_uint16(p, cache_flush ? (r->key->clazz | AVAHI_DNS_CACHE_FLUSH) : (r->key->clazz &~ AVAHI_DNS_CACHE_FLUSH)) ||
 757         !avahi_dns_packet_append_uint32(p, (max_ttl && r->ttl > max_ttl) ? max_ttl : r->ttl) ||
 758         !(l = avahi_dns_packet_append_uint16(p, 0)))
 759         goto fail;
 760
 761     start = avahi_dns_packet_extend(p, 0);
 762
 763     if (append_rdata(p, r) < 0)
 764         goto fail;
 765
 766     size = avahi_dns_packet_extend(p, 0) - start;
 767     assert(size <= 0xFFFF);
 768
 769 /*     avahi_log_debug("appended %u", size); */
 770
 771     l[0] = (uint8_t) ((uint16_t) size >> 8);
 772     l[1] = (uint8_t) ((uint16_t) size);
 773
 774     return t;
 775
 776
 777 fail:
 778     p->size = size;
 779     return NULL;
 780 }
 781
 782 int avahi_dns_packet_is_empty(AvahiDnsPacket *p) {
 783     assert(p);
 784
 785     return p->size <= AVAHI_DNS_PACKET_HEADER_SIZE;
 786 }
 787
 788 size_t avahi_dns_packet_space(AvahiDnsPacket *p) {
 789     assert(p);
 790
 791     assert(p->size <= p->max_size);
 792
 793     return p->max_size - p->size;
 794 }
 795
 796 int avahi_rdata_parse(AvahiRecord *record, const void* rdata, size_t size) {
 797     int ret;
 798     AvahiDnsPacket p;
 799
 800     assert(record);
 801     assert(rdata);
 802
 803     p.data = (void*) rdata;
 804     p.max_size = p.size = size;
 805     p.rindex = 0;
 806     p.name_table = NULL;
 807
 808     ret = parse_rdata(&p, record, size);
 809
 810     assert(!p.name_table);
 811
 812     return ret;
 813 }
 814
 815 size_t avahi_rdata_serialize(AvahiRecord *record, void *rdata, size_t max_size) {
 816     int ret;
 817     AvahiDnsPacket p;
 818
 819     assert(record);
 820     assert(rdata);
 821     assert(max_size > 0);
 822
 823     p.data = (void*) rdata;
 824     p.max_size = max_size;
 825     p.size = p.rindex = 0;
 826     p.name_table = NULL;
 827
 828     ret = append_rdata(&p, record);
 829
 830     if (p.name_table)
 831          avahi_hashmap_free(p.name_table);
 832
 833     if (ret < 0)
 834         return (size_t) -1;
 835
 836     return p.size;
 837 }