Tristan Matthews | 0a329cc | 2013-07-17 13:20:14 -0400 | [diff] [blame] | 1 | /* $Id$ */ |
| 2 | /* |
| 3 | * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) |
| 4 | * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program; if not, write to the Free Software |
| 18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 19 | */ |
| 20 | #include <pjlib-util/dns.h> |
| 21 | #include <pjlib-util/errno.h> |
| 22 | #include <pj/assert.h> |
| 23 | #include <pj/errno.h> |
| 24 | #include <pj/pool.h> |
| 25 | #include <pj/sock.h> |
| 26 | #include <pj/string.h> |
| 27 | |
| 28 | |
| 29 | PJ_DEF(const char *) pj_dns_get_type_name(int type) |
| 30 | { |
| 31 | switch (type) { |
| 32 | case PJ_DNS_TYPE_A: return "A"; |
| 33 | case PJ_DNS_TYPE_AAAA: return "AAAA"; |
| 34 | case PJ_DNS_TYPE_SRV: return "SRV"; |
| 35 | case PJ_DNS_TYPE_NS: return "NS"; |
| 36 | case PJ_DNS_TYPE_CNAME: return "CNAME"; |
| 37 | case PJ_DNS_TYPE_PTR: return "PTR"; |
| 38 | case PJ_DNS_TYPE_MX: return "MX"; |
| 39 | case PJ_DNS_TYPE_TXT: return "TXT"; |
| 40 | case PJ_DNS_TYPE_NAPTR: return "NAPTR"; |
| 41 | } |
| 42 | return "(Unknown)"; |
| 43 | } |
| 44 | |
| 45 | |
| 46 | static void write16(pj_uint8_t *p, pj_uint16_t val) |
| 47 | { |
| 48 | p[0] = (pj_uint8_t)(val >> 8); |
| 49 | p[1] = (pj_uint8_t)(val & 0xFF); |
| 50 | } |
| 51 | |
| 52 | |
| 53 | /** |
| 54 | * Initialize a DNS query transaction. |
| 55 | */ |
| 56 | PJ_DEF(pj_status_t) pj_dns_make_query( void *packet, |
| 57 | unsigned *size, |
| 58 | pj_uint16_t id, |
| 59 | int qtype, |
| 60 | const pj_str_t *name) |
| 61 | { |
| 62 | pj_uint8_t *query, *p = (pj_uint8_t*)packet; |
| 63 | const char *startlabel, *endlabel, *endname; |
| 64 | pj_size_t d; |
| 65 | |
| 66 | /* Sanity check */ |
| 67 | PJ_ASSERT_RETURN(packet && size && qtype && name, PJ_EINVAL); |
| 68 | |
| 69 | /* Calculate total number of bytes required. */ |
| 70 | d = sizeof(pj_dns_hdr) + name->slen + 4; |
| 71 | |
| 72 | /* Check that size is sufficient. */ |
| 73 | PJ_ASSERT_RETURN(*size >= d, PJLIB_UTIL_EDNSQRYTOOSMALL); |
| 74 | |
| 75 | /* Initialize header */ |
| 76 | pj_assert(sizeof(pj_dns_hdr)==12); |
| 77 | pj_bzero(p, sizeof(struct pj_dns_hdr)); |
| 78 | write16(p+0, id); |
| 79 | write16(p+2, (pj_uint16_t)PJ_DNS_SET_RD(1)); |
| 80 | write16(p+4, (pj_uint16_t)1); |
| 81 | |
| 82 | /* Initialize query */ |
| 83 | query = p = ((pj_uint8_t*)packet)+sizeof(pj_dns_hdr); |
| 84 | |
| 85 | /* Tokenize name */ |
| 86 | startlabel = endlabel = name->ptr; |
| 87 | endname = name->ptr + name->slen; |
| 88 | while (endlabel != endname) { |
| 89 | while (endlabel != endname && *endlabel != '.') |
| 90 | ++endlabel; |
| 91 | *p++ = (pj_uint8_t)(endlabel - startlabel); |
| 92 | pj_memcpy(p, startlabel, endlabel-startlabel); |
| 93 | p += (endlabel-startlabel); |
| 94 | if (endlabel != endname && *endlabel == '.') |
| 95 | ++endlabel; |
| 96 | startlabel = endlabel; |
| 97 | } |
| 98 | *p++ = '\0'; |
| 99 | |
| 100 | /* Set type */ |
| 101 | write16(p, (pj_uint16_t)qtype); |
| 102 | p += 2; |
| 103 | |
| 104 | /* Set class (IN=1) */ |
| 105 | write16(p, 1); |
| 106 | p += 2; |
| 107 | |
| 108 | /* Done, calculate length */ |
| 109 | *size = (unsigned)(p - (pj_uint8_t*)packet); |
| 110 | |
| 111 | return 0; |
| 112 | } |
| 113 | |
| 114 | |
| 115 | /* Get a name length (note: name consists of multiple labels and |
| 116 | * it may contain pointers when name compression is applied) |
| 117 | */ |
| 118 | static pj_status_t get_name_len(int rec_counter, const pj_uint8_t *pkt, |
| 119 | const pj_uint8_t *start, const pj_uint8_t *max, |
| 120 | int *parsed_len, int *name_len) |
| 121 | { |
| 122 | const pj_uint8_t *p; |
| 123 | pj_status_t status; |
| 124 | |
| 125 | /* Limit the number of recursion */ |
| 126 | if (rec_counter > 10) { |
| 127 | /* Too many name recursion */ |
| 128 | return PJLIB_UTIL_EDNSINNAMEPTR; |
| 129 | } |
| 130 | |
| 131 | *name_len = *parsed_len = 0; |
| 132 | p = start; |
| 133 | while (*p) { |
| 134 | if ((*p & 0xc0) == 0xc0) { |
| 135 | /* Compression is found! */ |
| 136 | int ptr_len = 0; |
| 137 | int dummy; |
| 138 | pj_uint16_t offset; |
| 139 | |
| 140 | /* Get the 14bit offset */ |
| 141 | pj_memcpy(&offset, p, 2); |
| 142 | offset ^= pj_htons((pj_uint16_t)(0xc0 << 8)); |
| 143 | offset = pj_ntohs(offset); |
| 144 | |
| 145 | /* Check that offset is valid */ |
| 146 | if (offset >= max - pkt) |
| 147 | return PJLIB_UTIL_EDNSINNAMEPTR; |
| 148 | |
| 149 | /* Get the name length from that offset. */ |
| 150 | status = get_name_len(rec_counter+1, pkt, pkt + offset, max, |
| 151 | &dummy, &ptr_len); |
| 152 | if (status != PJ_SUCCESS) |
| 153 | return status; |
| 154 | |
| 155 | *parsed_len += 2; |
| 156 | *name_len += ptr_len; |
| 157 | |
| 158 | return PJ_SUCCESS; |
| 159 | } else { |
| 160 | unsigned label_len = *p; |
| 161 | |
| 162 | /* Check that label length is valid */ |
| 163 | if (pkt+label_len > max) |
| 164 | return PJLIB_UTIL_EDNSINNAMEPTR; |
| 165 | |
| 166 | p += (label_len + 1); |
| 167 | *parsed_len += (label_len + 1); |
| 168 | |
| 169 | if (*p != 0) |
| 170 | ++label_len; |
| 171 | |
| 172 | *name_len += label_len; |
| 173 | |
| 174 | if (p >= max) |
| 175 | return PJLIB_UTIL_EDNSINSIZE; |
| 176 | } |
| 177 | } |
| 178 | ++p; |
| 179 | (*parsed_len)++; |
| 180 | |
| 181 | return PJ_SUCCESS; |
| 182 | } |
| 183 | |
| 184 | |
| 185 | /* Parse and copy name (note: name consists of multiple labels and |
| 186 | * it may contain pointers when compression is applied). |
| 187 | */ |
| 188 | static pj_status_t get_name(int rec_counter, const pj_uint8_t *pkt, |
| 189 | const pj_uint8_t *start, const pj_uint8_t *max, |
| 190 | pj_str_t *name) |
| 191 | { |
| 192 | const pj_uint8_t *p; |
| 193 | pj_status_t status; |
| 194 | |
| 195 | /* Limit the number of recursion */ |
| 196 | if (rec_counter > 10) { |
| 197 | /* Too many name recursion */ |
| 198 | return PJLIB_UTIL_EDNSINNAMEPTR; |
| 199 | } |
| 200 | |
| 201 | p = start; |
| 202 | while (*p) { |
| 203 | if ((*p & 0xc0) == 0xc0) { |
| 204 | /* Compression is found! */ |
| 205 | pj_uint16_t offset; |
| 206 | |
| 207 | /* Get the 14bit offset */ |
| 208 | pj_memcpy(&offset, p, 2); |
| 209 | offset ^= pj_htons((pj_uint16_t)(0xc0 << 8)); |
| 210 | offset = pj_ntohs(offset); |
| 211 | |
| 212 | /* Check that offset is valid */ |
| 213 | if (offset >= max - pkt) |
| 214 | return PJLIB_UTIL_EDNSINNAMEPTR; |
| 215 | |
| 216 | /* Retrieve the name from that offset. */ |
| 217 | status = get_name(rec_counter+1, pkt, pkt + offset, max, name); |
| 218 | if (status != PJ_SUCCESS) |
| 219 | return status; |
| 220 | |
| 221 | return PJ_SUCCESS; |
| 222 | } else { |
| 223 | unsigned label_len = *p; |
| 224 | |
| 225 | /* Check that label length is valid */ |
| 226 | if (pkt+label_len > max) |
| 227 | return PJLIB_UTIL_EDNSINNAMEPTR; |
| 228 | |
| 229 | pj_memcpy(name->ptr + name->slen, p+1, label_len); |
| 230 | name->slen += label_len; |
| 231 | |
| 232 | p += label_len + 1; |
| 233 | if (*p != 0) { |
| 234 | *(name->ptr + name->slen) = '.'; |
| 235 | ++name->slen; |
| 236 | } |
| 237 | |
| 238 | if (p >= max) |
| 239 | return PJLIB_UTIL_EDNSINSIZE; |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | return PJ_SUCCESS; |
| 244 | } |
| 245 | |
| 246 | |
| 247 | /* Parse query records. */ |
| 248 | static pj_status_t parse_query(pj_dns_parsed_query *q, pj_pool_t *pool, |
| 249 | const pj_uint8_t *pkt, const pj_uint8_t *start, |
| 250 | const pj_uint8_t *max, int *parsed_len) |
| 251 | { |
| 252 | const pj_uint8_t *p = start; |
| 253 | int name_len, name_part_len; |
| 254 | pj_status_t status; |
| 255 | |
| 256 | /* Get the length of the name */ |
| 257 | status = get_name_len(0, pkt, start, max, &name_part_len, &name_len); |
| 258 | if (status != PJ_SUCCESS) |
| 259 | return status; |
| 260 | |
| 261 | /* Allocate memory for the name */ |
| 262 | q->name.ptr = (char*) pj_pool_alloc(pool, name_len+4); |
| 263 | q->name.slen = 0; |
| 264 | |
| 265 | /* Get the name */ |
| 266 | status = get_name(0, pkt, start, max, &q->name); |
| 267 | if (status != PJ_SUCCESS) |
| 268 | return status; |
| 269 | |
| 270 | p = (start + name_part_len); |
| 271 | |
| 272 | /* Get the type */ |
| 273 | pj_memcpy(&q->type, p, 2); |
| 274 | q->type = pj_ntohs(q->type); |
| 275 | p += 2; |
| 276 | |
| 277 | /* Get the class */ |
| 278 | pj_memcpy(&q->dnsclass, p, 2); |
| 279 | q->dnsclass = pj_ntohs(q->dnsclass); |
| 280 | p += 2; |
| 281 | |
| 282 | *parsed_len = (int)(p - start); |
| 283 | |
| 284 | return PJ_SUCCESS; |
| 285 | } |
| 286 | |
| 287 | |
| 288 | /* Parse RR records */ |
| 289 | static pj_status_t parse_rr(pj_dns_parsed_rr *rr, pj_pool_t *pool, |
| 290 | const pj_uint8_t *pkt, |
| 291 | const pj_uint8_t *start, const pj_uint8_t *max, |
| 292 | int *parsed_len) |
| 293 | { |
| 294 | const pj_uint8_t *p = start; |
| 295 | int name_len, name_part_len; |
| 296 | pj_status_t status; |
| 297 | |
| 298 | /* Get the length of the name */ |
| 299 | status = get_name_len(0, pkt, start, max, &name_part_len, &name_len); |
| 300 | if (status != PJ_SUCCESS) |
| 301 | return status; |
| 302 | |
| 303 | /* Allocate memory for the name */ |
| 304 | rr->name.ptr = (char*) pj_pool_alloc(pool, name_len+4); |
| 305 | rr->name.slen = 0; |
| 306 | |
| 307 | /* Get the name */ |
| 308 | status = get_name(0, pkt, start, max, &rr->name); |
| 309 | if (status != PJ_SUCCESS) |
| 310 | return status; |
| 311 | |
| 312 | p = (start + name_part_len); |
| 313 | |
| 314 | /* Check the size can accomodate next few fields. */ |
| 315 | if (p+10 > max) |
| 316 | return PJLIB_UTIL_EDNSINSIZE; |
| 317 | |
| 318 | /* Get the type */ |
| 319 | pj_memcpy(&rr->type, p, 2); |
| 320 | rr->type = pj_ntohs(rr->type); |
| 321 | p += 2; |
| 322 | |
| 323 | /* Get the class */ |
| 324 | pj_memcpy(&rr->dnsclass, p, 2); |
| 325 | rr->dnsclass = pj_ntohs(rr->dnsclass); |
| 326 | p += 2; |
| 327 | |
| 328 | /* Class MUST be IN */ |
| 329 | if (rr->dnsclass != 1) |
| 330 | return PJLIB_UTIL_EDNSINCLASS; |
| 331 | |
| 332 | /* Get TTL */ |
| 333 | pj_memcpy(&rr->ttl, p, 4); |
| 334 | rr->ttl = pj_ntohl(rr->ttl); |
| 335 | p += 4; |
| 336 | |
| 337 | /* Get rdlength */ |
| 338 | pj_memcpy(&rr->rdlength, p, 2); |
| 339 | rr->rdlength = pj_ntohs(rr->rdlength); |
| 340 | p += 2; |
| 341 | |
| 342 | /* Check that length is valid */ |
| 343 | if (p + rr->rdlength > max) |
| 344 | return PJLIB_UTIL_EDNSINSIZE; |
| 345 | |
| 346 | /* Parse some well known records */ |
| 347 | if (rr->type == PJ_DNS_TYPE_A) { |
| 348 | pj_memcpy(&rr->rdata.a.ip_addr, p, 4); |
| 349 | p += 4; |
| 350 | |
| 351 | } else if (rr->type == PJ_DNS_TYPE_AAAA) { |
| 352 | pj_memcpy(&rr->rdata.aaaa.ip_addr, p, 16); |
| 353 | p += 16; |
| 354 | |
| 355 | } else if (rr->type == PJ_DNS_TYPE_CNAME || |
| 356 | rr->type == PJ_DNS_TYPE_NS || |
| 357 | rr->type == PJ_DNS_TYPE_PTR) |
| 358 | { |
| 359 | |
| 360 | /* Get the length of the target name */ |
| 361 | status = get_name_len(0, pkt, p, max, &name_part_len, &name_len); |
| 362 | if (status != PJ_SUCCESS) |
| 363 | return status; |
| 364 | |
| 365 | /* Allocate memory for the name */ |
| 366 | rr->rdata.cname.name.ptr = (char*) pj_pool_alloc(pool, name_len); |
| 367 | rr->rdata.cname.name.slen = 0; |
| 368 | |
| 369 | /* Get the name */ |
| 370 | status = get_name(0, pkt, p, max, &rr->rdata.cname.name); |
| 371 | if (status != PJ_SUCCESS) |
| 372 | return status; |
| 373 | |
| 374 | p += name_part_len; |
| 375 | |
| 376 | } else if (rr->type == PJ_DNS_TYPE_SRV) { |
| 377 | |
| 378 | /* Priority */ |
| 379 | pj_memcpy(&rr->rdata.srv.prio, p, 2); |
| 380 | rr->rdata.srv.prio = pj_ntohs(rr->rdata.srv.prio); |
| 381 | p += 2; |
| 382 | |
| 383 | /* Weight */ |
| 384 | pj_memcpy(&rr->rdata.srv.weight, p, 2); |
| 385 | rr->rdata.srv.weight = pj_ntohs(rr->rdata.srv.weight); |
| 386 | p += 2; |
| 387 | |
| 388 | /* Port */ |
| 389 | pj_memcpy(&rr->rdata.srv.port, p, 2); |
| 390 | rr->rdata.srv.port = pj_ntohs(rr->rdata.srv.port); |
| 391 | p += 2; |
| 392 | |
| 393 | /* Get the length of the target name */ |
| 394 | status = get_name_len(0, pkt, p, max, &name_part_len, &name_len); |
| 395 | if (status != PJ_SUCCESS) |
| 396 | return status; |
| 397 | |
| 398 | /* Allocate memory for the name */ |
| 399 | rr->rdata.srv.target.ptr = (char*) pj_pool_alloc(pool, name_len); |
| 400 | rr->rdata.srv.target.slen = 0; |
| 401 | |
| 402 | /* Get the name */ |
| 403 | status = get_name(0, pkt, p, max, &rr->rdata.srv.target); |
| 404 | if (status != PJ_SUCCESS) |
| 405 | return status; |
| 406 | p += name_part_len; |
| 407 | |
| 408 | } else { |
| 409 | /* Copy the raw data */ |
| 410 | rr->data = pj_pool_alloc(pool, rr->rdlength); |
| 411 | pj_memcpy(rr->data, p, rr->rdlength); |
| 412 | |
| 413 | p += rr->rdlength; |
| 414 | } |
| 415 | |
| 416 | *parsed_len = (int)(p - start); |
| 417 | return PJ_SUCCESS; |
| 418 | } |
| 419 | |
| 420 | |
| 421 | /* |
| 422 | * Parse raw DNS packet into DNS packet structure. |
| 423 | */ |
| 424 | PJ_DEF(pj_status_t) pj_dns_parse_packet( pj_pool_t *pool, |
| 425 | const void *packet, |
| 426 | unsigned size, |
| 427 | pj_dns_parsed_packet **p_res) |
| 428 | { |
| 429 | pj_dns_parsed_packet *res; |
| 430 | const pj_uint8_t *start, *end; |
| 431 | pj_status_t status; |
| 432 | unsigned i; |
| 433 | |
| 434 | /* Sanity checks */ |
| 435 | PJ_ASSERT_RETURN(pool && packet && size && p_res, PJ_EINVAL); |
| 436 | |
| 437 | /* Packet size must be at least as big as the header */ |
| 438 | if (size < sizeof(pj_dns_hdr)) |
| 439 | return PJLIB_UTIL_EDNSINSIZE; |
| 440 | |
| 441 | /* Create the structure */ |
| 442 | res = PJ_POOL_ZALLOC_T(pool, pj_dns_parsed_packet); |
| 443 | |
| 444 | /* Copy the DNS header, and convert endianness to host byte order */ |
| 445 | pj_memcpy(&res->hdr, packet, sizeof(pj_dns_hdr)); |
| 446 | res->hdr.id = pj_ntohs(res->hdr.id); |
| 447 | res->hdr.flags = pj_ntohs(res->hdr.flags); |
| 448 | res->hdr.qdcount = pj_ntohs(res->hdr.qdcount); |
| 449 | res->hdr.anscount = pj_ntohs(res->hdr.anscount); |
| 450 | res->hdr.nscount = pj_ntohs(res->hdr.nscount); |
| 451 | res->hdr.arcount = pj_ntohs(res->hdr.arcount); |
| 452 | |
| 453 | /* Mark start and end of payload */ |
| 454 | start = ((const pj_uint8_t*)packet) + sizeof(pj_dns_hdr); |
| 455 | end = ((const pj_uint8_t*)packet) + size; |
| 456 | |
| 457 | /* Parse query records (if any). |
| 458 | */ |
| 459 | if (res->hdr.qdcount) { |
| 460 | res->q = (pj_dns_parsed_query*) |
| 461 | pj_pool_zalloc(pool, res->hdr.qdcount * |
| 462 | sizeof(pj_dns_parsed_query)); |
| 463 | for (i=0; i<res->hdr.qdcount; ++i) { |
| 464 | int parsed_len = 0; |
| 465 | |
| 466 | status = parse_query(&res->q[i], pool, (const pj_uint8_t*)packet, |
| 467 | start, end, &parsed_len); |
| 468 | if (status != PJ_SUCCESS) |
| 469 | return status; |
| 470 | |
| 471 | start += parsed_len; |
| 472 | } |
| 473 | } |
| 474 | |
| 475 | /* Parse answer, if any */ |
| 476 | if (res->hdr.anscount) { |
| 477 | res->ans = (pj_dns_parsed_rr*) |
| 478 | pj_pool_zalloc(pool, res->hdr.anscount * |
| 479 | sizeof(pj_dns_parsed_rr)); |
| 480 | |
| 481 | for (i=0; i<res->hdr.anscount; ++i) { |
| 482 | int parsed_len; |
| 483 | |
| 484 | status = parse_rr(&res->ans[i], pool, (const pj_uint8_t*)packet, |
| 485 | start, end, &parsed_len); |
| 486 | if (status != PJ_SUCCESS) |
| 487 | return status; |
| 488 | |
| 489 | start += parsed_len; |
| 490 | } |
| 491 | } |
| 492 | |
| 493 | /* Parse authoritative NS records, if any */ |
| 494 | if (res->hdr.nscount) { |
| 495 | res->ns = (pj_dns_parsed_rr*) |
| 496 | pj_pool_zalloc(pool, res->hdr.nscount * |
| 497 | sizeof(pj_dns_parsed_rr)); |
| 498 | |
| 499 | for (i=0; i<res->hdr.nscount; ++i) { |
| 500 | int parsed_len; |
| 501 | |
| 502 | status = parse_rr(&res->ns[i], pool, (const pj_uint8_t*)packet, |
| 503 | start, end, &parsed_len); |
| 504 | if (status != PJ_SUCCESS) |
| 505 | return status; |
| 506 | |
| 507 | start += parsed_len; |
| 508 | } |
| 509 | } |
| 510 | |
| 511 | /* Parse additional RR answer, if any */ |
| 512 | if (res->hdr.arcount) { |
| 513 | res->arr = (pj_dns_parsed_rr*) |
| 514 | pj_pool_zalloc(pool, res->hdr.arcount * |
| 515 | sizeof(pj_dns_parsed_rr)); |
| 516 | |
| 517 | for (i=0; i<res->hdr.arcount; ++i) { |
| 518 | int parsed_len; |
| 519 | |
| 520 | status = parse_rr(&res->arr[i], pool, (const pj_uint8_t*)packet, |
| 521 | start, end, &parsed_len); |
| 522 | if (status != PJ_SUCCESS) |
| 523 | return status; |
| 524 | |
| 525 | start += parsed_len; |
| 526 | } |
| 527 | } |
| 528 | |
| 529 | /* Looks like everything is okay */ |
| 530 | *p_res = res; |
| 531 | |
| 532 | return PJ_SUCCESS; |
| 533 | } |
| 534 | |
| 535 | |
| 536 | /* Perform name compression scheme. |
| 537 | * If a name is already in the nametable, when no need to duplicate |
| 538 | * the string with the pool, but rather just use the pointer there. |
| 539 | */ |
| 540 | static void apply_name_table( unsigned *count, |
| 541 | pj_str_t nametable[], |
| 542 | const pj_str_t *src, |
| 543 | pj_pool_t *pool, |
| 544 | pj_str_t *dst) |
| 545 | { |
| 546 | unsigned i; |
| 547 | |
| 548 | /* Scan strings in nametable */ |
| 549 | for (i=0; i<*count; ++i) { |
| 550 | if (pj_stricmp(&nametable[i], src) == 0) |
| 551 | break; |
| 552 | } |
| 553 | |
| 554 | /* If name is found in nametable, use the pointer in the nametable */ |
| 555 | if (i != *count) { |
| 556 | dst->ptr = nametable[i].ptr; |
| 557 | dst->slen = nametable[i].slen; |
| 558 | return; |
| 559 | } |
| 560 | |
| 561 | /* Otherwise duplicate the string, and insert new name in nametable */ |
| 562 | pj_strdup(pool, dst, src); |
| 563 | |
| 564 | if (*count < PJ_DNS_MAX_NAMES_IN_NAMETABLE) { |
| 565 | nametable[*count].ptr = dst->ptr; |
| 566 | nametable[*count].slen = dst->slen; |
| 567 | |
| 568 | ++(*count); |
| 569 | } |
| 570 | } |
| 571 | |
| 572 | static void copy_query(pj_pool_t *pool, pj_dns_parsed_query *dst, |
| 573 | const pj_dns_parsed_query *src, |
| 574 | unsigned *nametable_count, |
| 575 | pj_str_t nametable[]) |
| 576 | { |
| 577 | pj_memcpy(dst, src, sizeof(*src)); |
| 578 | apply_name_table(nametable_count, nametable, &src->name, pool, &dst->name); |
| 579 | } |
| 580 | |
| 581 | |
| 582 | static void copy_rr(pj_pool_t *pool, pj_dns_parsed_rr *dst, |
| 583 | const pj_dns_parsed_rr *src, |
| 584 | unsigned *nametable_count, |
| 585 | pj_str_t nametable[]) |
| 586 | { |
| 587 | pj_memcpy(dst, src, sizeof(*src)); |
| 588 | apply_name_table(nametable_count, nametable, &src->name, pool, &dst->name); |
| 589 | |
| 590 | if (src->data) { |
| 591 | dst->data = pj_pool_alloc(pool, src->rdlength); |
| 592 | pj_memcpy(dst->data, src->data, src->rdlength); |
| 593 | } |
| 594 | |
| 595 | if (src->type == PJ_DNS_TYPE_SRV) { |
| 596 | apply_name_table(nametable_count, nametable, &src->rdata.srv.target, |
| 597 | pool, &dst->rdata.srv.target); |
| 598 | } else if (src->type == PJ_DNS_TYPE_A) { |
| 599 | dst->rdata.a.ip_addr.s_addr = src->rdata.a.ip_addr.s_addr; |
| 600 | } else if (src->type == PJ_DNS_TYPE_AAAA) { |
| 601 | pj_memcpy(&dst->rdata.aaaa.ip_addr, &src->rdata.aaaa.ip_addr, |
| 602 | sizeof(pj_in6_addr)); |
| 603 | } else if (src->type == PJ_DNS_TYPE_CNAME) { |
| 604 | pj_strdup(pool, &dst->rdata.cname.name, &src->rdata.cname.name); |
| 605 | } else if (src->type == PJ_DNS_TYPE_NS) { |
| 606 | pj_strdup(pool, &dst->rdata.ns.name, &src->rdata.ns.name); |
| 607 | } else if (src->type == PJ_DNS_TYPE_PTR) { |
| 608 | pj_strdup(pool, &dst->rdata.ptr.name, &src->rdata.ptr.name); |
| 609 | } |
| 610 | } |
| 611 | |
| 612 | /* |
| 613 | * Duplicate DNS packet. |
| 614 | */ |
| 615 | PJ_DEF(void) pj_dns_packet_dup(pj_pool_t *pool, |
| 616 | const pj_dns_parsed_packet*p, |
| 617 | unsigned options, |
| 618 | pj_dns_parsed_packet **p_dst) |
| 619 | { |
| 620 | pj_dns_parsed_packet *dst; |
| 621 | unsigned nametable_count = 0; |
| 622 | #if PJ_DNS_MAX_NAMES_IN_NAMETABLE |
| 623 | pj_str_t nametable[PJ_DNS_MAX_NAMES_IN_NAMETABLE]; |
| 624 | #else |
| 625 | pj_str_t *nametable = NULL; |
| 626 | #endif |
| 627 | unsigned i; |
| 628 | |
| 629 | PJ_ASSERT_ON_FAIL(pool && p && p_dst, return); |
| 630 | |
| 631 | /* Create packet and copy header */ |
| 632 | *p_dst = dst = PJ_POOL_ZALLOC_T(pool, pj_dns_parsed_packet); |
| 633 | pj_memcpy(&dst->hdr, &p->hdr, sizeof(p->hdr)); |
| 634 | |
| 635 | /* Initialize section counts in the target packet to zero. |
| 636 | * If memory allocation fails during copying process, the target packet |
| 637 | * should have a correct section counts. |
| 638 | */ |
| 639 | dst->hdr.qdcount = 0; |
| 640 | dst->hdr.anscount = 0; |
| 641 | dst->hdr.nscount = 0; |
| 642 | dst->hdr.arcount = 0; |
| 643 | |
| 644 | |
| 645 | /* Copy query section */ |
| 646 | if (p->hdr.qdcount && (options & PJ_DNS_NO_QD)==0) { |
| 647 | dst->q = (pj_dns_parsed_query*) |
| 648 | pj_pool_alloc(pool, p->hdr.qdcount * |
| 649 | sizeof(pj_dns_parsed_query)); |
| 650 | for (i=0; i<p->hdr.qdcount; ++i) { |
| 651 | copy_query(pool, &dst->q[i], &p->q[i], |
| 652 | &nametable_count, nametable); |
| 653 | ++dst->hdr.qdcount; |
| 654 | } |
| 655 | } |
| 656 | |
| 657 | /* Copy answer section */ |
| 658 | if (p->hdr.anscount && (options & PJ_DNS_NO_ANS)==0) { |
| 659 | dst->ans = (pj_dns_parsed_rr*) |
| 660 | pj_pool_alloc(pool, p->hdr.anscount * |
| 661 | sizeof(pj_dns_parsed_rr)); |
| 662 | for (i=0; i<p->hdr.anscount; ++i) { |
| 663 | copy_rr(pool, &dst->ans[i], &p->ans[i], |
| 664 | &nametable_count, nametable); |
| 665 | ++dst->hdr.anscount; |
| 666 | } |
| 667 | } |
| 668 | |
| 669 | /* Copy NS section */ |
| 670 | if (p->hdr.nscount && (options & PJ_DNS_NO_NS)==0) { |
| 671 | dst->ns = (pj_dns_parsed_rr*) |
| 672 | pj_pool_alloc(pool, p->hdr.nscount * |
| 673 | sizeof(pj_dns_parsed_rr)); |
| 674 | for (i=0; i<p->hdr.nscount; ++i) { |
| 675 | copy_rr(pool, &dst->ns[i], &p->ns[i], |
| 676 | &nametable_count, nametable); |
| 677 | ++dst->hdr.nscount; |
| 678 | } |
| 679 | } |
| 680 | |
| 681 | /* Copy additional info section */ |
| 682 | if (p->hdr.arcount && (options & PJ_DNS_NO_AR)==0) { |
| 683 | dst->arr = (pj_dns_parsed_rr*) |
| 684 | pj_pool_alloc(pool, p->hdr.arcount * |
| 685 | sizeof(pj_dns_parsed_rr)); |
| 686 | for (i=0; i<p->hdr.arcount; ++i) { |
| 687 | copy_rr(pool, &dst->arr[i], &p->arr[i], |
| 688 | &nametable_count, nametable); |
| 689 | ++dst->hdr.arcount; |
| 690 | } |
| 691 | } |
| 692 | } |
| 693 | |
| 694 | |
| 695 | PJ_DEF(void) pj_dns_init_srv_rr( pj_dns_parsed_rr *rec, |
| 696 | const pj_str_t *res_name, |
| 697 | unsigned dnsclass, |
| 698 | unsigned ttl, |
| 699 | unsigned prio, |
| 700 | unsigned weight, |
| 701 | unsigned port, |
| 702 | const pj_str_t *target) |
| 703 | { |
| 704 | pj_bzero(rec, sizeof(*rec)); |
| 705 | rec->name = *res_name; |
| 706 | rec->type = PJ_DNS_TYPE_SRV; |
| 707 | rec->dnsclass = (pj_uint16_t) dnsclass; |
| 708 | rec->ttl = ttl; |
| 709 | rec->rdata.srv.prio = (pj_uint16_t) prio; |
| 710 | rec->rdata.srv.weight = (pj_uint16_t) weight; |
| 711 | rec->rdata.srv.port = (pj_uint16_t) port; |
| 712 | rec->rdata.srv.target = *target; |
| 713 | } |
| 714 | |
| 715 | |
| 716 | PJ_DEF(void) pj_dns_init_cname_rr( pj_dns_parsed_rr *rec, |
| 717 | const pj_str_t *res_name, |
| 718 | unsigned dnsclass, |
| 719 | unsigned ttl, |
| 720 | const pj_str_t *name) |
| 721 | { |
| 722 | pj_bzero(rec, sizeof(*rec)); |
| 723 | rec->name = *res_name; |
| 724 | rec->type = PJ_DNS_TYPE_CNAME; |
| 725 | rec->dnsclass = (pj_uint16_t) dnsclass; |
| 726 | rec->ttl = ttl; |
| 727 | rec->rdata.cname.name = *name; |
| 728 | } |
| 729 | |
| 730 | |
| 731 | PJ_DEF(void) pj_dns_init_a_rr( pj_dns_parsed_rr *rec, |
| 732 | const pj_str_t *res_name, |
| 733 | unsigned dnsclass, |
| 734 | unsigned ttl, |
| 735 | const pj_in_addr *ip_addr) |
| 736 | { |
| 737 | pj_bzero(rec, sizeof(*rec)); |
| 738 | rec->name = *res_name; |
| 739 | rec->type = PJ_DNS_TYPE_A; |
| 740 | rec->dnsclass = (pj_uint16_t) dnsclass; |
| 741 | rec->ttl = ttl; |
| 742 | rec->rdata.a.ip_addr = *ip_addr; |
| 743 | } |
| 744 | |