1 #if !defined(lint) && !defined(SABER) 2 static const char rcsid[] = "$Id: res_findzonecut.c,v 1.10 2005/10/11 00:10:16 marka Exp $"; 3 #endif /* not lint */ 4 5 /*- 6 * SPDX-License-Identifier: ISC 7 * 8 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 9 * Copyright (c) 1999 by Internet Software Consortium. 10 * 11 * Permission to use, copy, modify, and distribute this software for any 12 * purpose with or without fee is hereby granted, provided that the above 13 * copyright notice and this permission notice appear in all copies. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 16 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 17 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 18 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 19 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 20 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 21 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 22 */ 23 24 #include <sys/cdefs.h> 25 __FBSDID("$FreeBSD$"); 26 27 /* Import. */ 28 29 #include "port_before.h" 30 31 #include <sys/param.h> 32 #include <sys/socket.h> 33 #include <sys/time.h> 34 35 #include <netinet/in.h> 36 #include <arpa/inet.h> 37 #include <arpa/nameser.h> 38 39 #include <errno.h> 40 #include <limits.h> 41 #include <netdb.h> 42 #include <stdarg.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 47 #include <isc/list.h> 48 49 #include "port_after.h" 50 51 #include <resolv.h> 52 53 /* Data structures. */ 54 55 typedef struct rr_a { 56 LINK(struct rr_a) link; 57 union res_sockaddr_union addr; 58 } rr_a; 59 typedef LIST(rr_a) rrset_a; 60 61 typedef struct rr_ns { 62 LINK(struct rr_ns) link; 63 const char * name; 64 unsigned int flags; 65 rrset_a addrs; 66 } rr_ns; 67 typedef LIST(rr_ns) rrset_ns; 68 69 #define RR_NS_HAVE_V4 0x01 70 #define RR_NS_HAVE_V6 0x02 71 72 /* Forward. */ 73 74 static int satisfy(res_state, const char *, rrset_ns *, 75 union res_sockaddr_union *, int); 76 static int add_addrs(res_state, rr_ns *, 77 union res_sockaddr_union *, int); 78 static int get_soa(res_state, const char *, ns_class, int, 79 char *, size_t, char *, size_t, 80 rrset_ns *); 81 static int get_ns(res_state, const char *, ns_class, int, rrset_ns *); 82 static int get_glue(res_state, ns_class, int, rrset_ns *); 83 static int save_ns(res_state, ns_msg *, ns_sect, 84 const char *, ns_class, int, rrset_ns *); 85 static int save_a(res_state, ns_msg *, ns_sect, 86 const char *, ns_class, int, rr_ns *); 87 static void free_nsrrset(rrset_ns *); 88 static void free_nsrr(rrset_ns *, rr_ns *); 89 static rr_ns * find_ns(rrset_ns *, const char *); 90 static int do_query(res_state, const char *, ns_class, ns_type, 91 u_char *, ns_msg *); 92 static void res_dprintf(const char *, ...) ISC_FORMAT_PRINTF(1, 2); 93 94 /* Macros. */ 95 96 #define DPRINTF(x) do {\ 97 int save_errno = errno; \ 98 if ((statp->options & RES_DEBUG) != 0U) res_dprintf x; \ 99 errno = save_errno; \ 100 } while (0) 101 102 /* Public. */ 103 104 /*% 105 * find enclosing zone for a <dname,class>, and some server addresses 106 * 107 * parameters: 108 *\li res - resolver context to work within (is modified) 109 *\li dname - domain name whose enclosing zone is desired 110 *\li class - class of dname (and its enclosing zone) 111 *\li zname - found zone name 112 *\li zsize - allocated size of zname 113 *\li addrs - found server addresses 114 *\li naddrs - max number of addrs 115 * 116 * return values: 117 *\li < 0 - an error occurred (check errno) 118 *\li = 0 - zname is now valid, but addrs[] wasn't changed 119 *\li > 0 - zname is now valid, and return value is number of addrs[] found 120 * 121 * notes: 122 *\li this function calls res_nsend() which means it depends on correctly 123 * functioning recursive nameservers (usually defined in /etc/resolv.conf 124 * or its local equivalent). 125 * 126 *\li we start by asking for an SOA<dname,class>. if we get one as an 127 * answer, that just means <dname,class> is a zone top, which is fine. 128 * more than likely we'll be told to go pound sand, in the form of a 129 * negative answer. 130 * 131 *\li note that we are not prepared to deal with referrals since that would 132 * only come from authority servers and our correctly functioning local 133 * recursive server would have followed the referral and got us something 134 * more definite. 135 * 136 *\li if the authority section contains an SOA, this SOA should also be the 137 * closest enclosing zone, since any intermediary zone cuts would've been 138 * returned as referrals and dealt with by our correctly functioning local 139 * recursive name server. but an SOA in the authority section should NOT 140 * match our dname (since that would have been returned in the answer 141 * section). an authority section SOA has to be "above" our dname. 142 * 143 *\li however, since authority section SOA's were once optional, it's 144 * possible that we'll have to go hunting for the enclosing SOA by 145 * ripping labels off the front of our dname -- this is known as "doing 146 * it the hard way." 147 * 148 *\li ultimately we want some server addresses, which are ideally the ones 149 * pertaining to the SOA.MNAME, but only if there is a matching NS RR. 150 * so the second phase (after we find an SOA) is to go looking for the 151 * NS RRset for that SOA's zone. 152 * 153 *\li no answer section processed by this code is allowed to contain CNAME 154 * or DNAME RR's. for the SOA query this means we strip a label and 155 * keep going. for the NS and A queries this means we just give up. 156 */ 157 158 #ifndef _LIBC 159 int 160 res_findzonecut(res_state statp, const char *dname, ns_class class, int opts, 161 char *zname, size_t zsize, struct in_addr *addrs, int naddrs) 162 { 163 int result, i; 164 union res_sockaddr_union *u; 165 166 167 opts |= RES_IPV4ONLY; 168 opts &= ~RES_IPV6ONLY; 169 170 u = calloc(naddrs, sizeof(*u)); 171 if (u == NULL) 172 return(-1); 173 174 result = res_findzonecut2(statp, dname, class, opts, zname, zsize, 175 u, naddrs); 176 177 for (i = 0; i < result; i++) { 178 addrs[i] = u[i].sin.sin_addr; 179 } 180 free(u); 181 return (result); 182 } 183 #endif 184 185 int 186 res_findzonecut2(res_state statp, const char *dname, ns_class class, int opts, 187 char *zname, size_t zsize, union res_sockaddr_union *addrs, 188 int naddrs) 189 { 190 char mname[NS_MAXDNAME]; 191 u_long save_pfcode; 192 rrset_ns nsrrs; 193 int n; 194 195 DPRINTF(("START dname='%s' class=%s, zsize=%ld, naddrs=%d", 196 dname, p_class(class), (long)zsize, naddrs)); 197 save_pfcode = statp->pfcode; 198 statp->pfcode |= RES_PRF_HEAD2 | RES_PRF_HEAD1 | RES_PRF_HEADX | 199 RES_PRF_QUES | RES_PRF_ANS | 200 RES_PRF_AUTH | RES_PRF_ADD; 201 INIT_LIST(nsrrs); 202 203 DPRINTF(("get the soa, and see if it has enough glue")); 204 if ((n = get_soa(statp, dname, class, opts, zname, zsize, 205 mname, sizeof mname, &nsrrs)) < 0 || 206 ((opts & RES_EXHAUSTIVE) == 0 && 207 (n = satisfy(statp, mname, &nsrrs, addrs, naddrs)) > 0)) 208 goto done; 209 210 DPRINTF(("get the ns rrset and see if it has enough glue")); 211 if ((n = get_ns(statp, zname, class, opts, &nsrrs)) < 0 || 212 ((opts & RES_EXHAUSTIVE) == 0 && 213 (n = satisfy(statp, mname, &nsrrs, addrs, naddrs)) > 0)) 214 goto done; 215 216 DPRINTF(("get the missing glue and see if it's finally enough")); 217 if ((n = get_glue(statp, class, opts, &nsrrs)) >= 0) 218 n = satisfy(statp, mname, &nsrrs, addrs, naddrs); 219 220 done: 221 DPRINTF(("FINISH n=%d (%s)", n, (n < 0) ? strerror(errno) : "OK")); 222 free_nsrrset(&nsrrs); 223 statp->pfcode = save_pfcode; 224 return (n); 225 } 226 227 /* Private. */ 228 229 static int 230 satisfy(res_state statp, const char *mname, rrset_ns *nsrrsp, 231 union res_sockaddr_union *addrs, int naddrs) 232 { 233 rr_ns *nsrr; 234 int n, x; 235 236 n = 0; 237 nsrr = find_ns(nsrrsp, mname); 238 if (nsrr != NULL) { 239 x = add_addrs(statp, nsrr, addrs, naddrs); 240 addrs += x; 241 naddrs -= x; 242 n += x; 243 } 244 for (nsrr = HEAD(*nsrrsp); 245 nsrr != NULL && naddrs > 0; 246 nsrr = NEXT(nsrr, link)) 247 if (ns_samename(nsrr->name, mname) != 1) { 248 x = add_addrs(statp, nsrr, addrs, naddrs); 249 addrs += x; 250 naddrs -= x; 251 n += x; 252 } 253 DPRINTF(("satisfy(%s): %d", mname, n)); 254 return (n); 255 } 256 257 static int 258 add_addrs(res_state statp, rr_ns *nsrr, 259 union res_sockaddr_union *addrs, int naddrs) 260 { 261 rr_a *arr; 262 int n = 0; 263 264 for (arr = HEAD(nsrr->addrs); arr != NULL; arr = NEXT(arr, link)) { 265 if (naddrs <= 0) 266 return (0); 267 *addrs++ = arr->addr; 268 naddrs--; 269 n++; 270 } 271 DPRINTF(("add_addrs: %d", n)); 272 return (n); 273 } 274 275 static int 276 get_soa(res_state statp, const char *dname, ns_class class, int opts, 277 char *zname, size_t zsize, char *mname, size_t msize, 278 rrset_ns *nsrrsp) 279 { 280 char tname[NS_MAXDNAME]; 281 u_char *resp = NULL; 282 int n, i, ancount, nscount; 283 ns_sect sect; 284 ns_msg msg; 285 u_int rcode; 286 287 /* 288 * Find closest enclosing SOA, even if it's for the root zone. 289 */ 290 291 /* First canonicalize dname (exactly one unescaped trailing "."). */ 292 if (ns_makecanon(dname, tname, sizeof tname) < 0) 293 goto cleanup; 294 dname = tname; 295 296 resp = malloc(NS_MAXMSG); 297 if (resp == NULL) 298 goto cleanup; 299 300 /* Now grovel the subdomains, hunting for an SOA answer or auth. */ 301 for (;;) { 302 /* Leading or inter-label '.' are skipped here. */ 303 while (*dname == '.') 304 dname++; 305 306 /* Is there an SOA? */ 307 n = do_query(statp, dname, class, ns_t_soa, resp, &msg); 308 if (n < 0) { 309 DPRINTF(("get_soa: do_query('%s', %s) failed (%d)", 310 dname, p_class(class), n)); 311 goto cleanup; 312 } 313 if (n > 0) { 314 DPRINTF(("get_soa: CNAME or DNAME found")); 315 sect = ns_s_max, n = 0; 316 } else { 317 rcode = ns_msg_getflag(msg, ns_f_rcode); 318 ancount = ns_msg_count(msg, ns_s_an); 319 nscount = ns_msg_count(msg, ns_s_ns); 320 if (ancount > 0 && rcode == ns_r_noerror) 321 sect = ns_s_an, n = ancount; 322 else if (nscount > 0) 323 sect = ns_s_ns, n = nscount; 324 else 325 sect = ns_s_max, n = 0; 326 } 327 for (i = 0; i < n; i++) { 328 const char *t; 329 const u_char *rdata; 330 ns_rr rr; 331 332 if (ns_parserr(&msg, sect, i, &rr) < 0) { 333 DPRINTF(("get_soa: ns_parserr(%s, %d) failed", 334 p_section(sect, ns_o_query), i)); 335 goto cleanup; 336 } 337 if (ns_rr_type(rr) == ns_t_cname || 338 ns_rr_type(rr) == ns_t_dname) 339 break; 340 if (ns_rr_type(rr) != ns_t_soa || 341 ns_rr_class(rr) != class) 342 continue; 343 t = ns_rr_name(rr); 344 switch (sect) { 345 case ns_s_an: 346 if (ns_samedomain(dname, t) == 0) { 347 DPRINTF( 348 ("get_soa: ns_samedomain('%s', '%s') == 0", 349 dname, t) 350 ); 351 errno = EPROTOTYPE; 352 goto cleanup; 353 } 354 break; 355 case ns_s_ns: 356 if (ns_samename(dname, t) == 1 || 357 ns_samedomain(dname, t) == 0) { 358 DPRINTF( 359 ("get_soa: ns_samename() || !ns_samedomain('%s', '%s')", 360 dname, t) 361 ); 362 errno = EPROTOTYPE; 363 goto cleanup; 364 } 365 break; 366 default: 367 abort(); 368 } 369 if (strlen(t) + 1 > zsize) { 370 DPRINTF(("get_soa: zname(%lu) too small (%lu)", 371 (unsigned long)zsize, 372 (unsigned long)strlen(t) + 1)); 373 errno = EMSGSIZE; 374 goto cleanup; 375 } 376 strcpy(zname, t); 377 rdata = ns_rr_rdata(rr); 378 if (ns_name_uncompress(resp, ns_msg_end(msg), rdata, 379 mname, msize) < 0) { 380 DPRINTF(("get_soa: ns_name_uncompress failed") 381 ); 382 goto cleanup; 383 } 384 if (save_ns(statp, &msg, ns_s_ns, 385 zname, class, opts, nsrrsp) < 0) { 386 DPRINTF(("get_soa: save_ns failed")); 387 goto cleanup; 388 } 389 free(resp); 390 return (0); 391 } 392 393 /* If we're out of labels, then not even "." has an SOA! */ 394 if (*dname == '\0') 395 break; 396 397 /* Find label-terminating "."; top of loop will skip it. */ 398 while (*dname != '.') { 399 if (*dname == '\\') 400 if (*++dname == '\0') { 401 errno = EMSGSIZE; 402 goto cleanup; 403 } 404 dname++; 405 } 406 } 407 DPRINTF(("get_soa: out of labels")); 408 errno = EDESTADDRREQ; 409 cleanup: 410 if (resp != NULL) 411 free(resp); 412 return (-1); 413 } 414 415 static int 416 get_ns(res_state statp, const char *zname, ns_class class, int opts, 417 rrset_ns *nsrrsp) 418 { 419 u_char *resp; 420 ns_msg msg; 421 int n; 422 423 resp = malloc(NS_MAXMSG); 424 if (resp == NULL) 425 return (-1); 426 427 /* Go and get the NS RRs for this zone. */ 428 n = do_query(statp, zname, class, ns_t_ns, resp, &msg); 429 if (n != 0) { 430 DPRINTF(("get_ns: do_query('%s', %s) failed (%d)", 431 zname, p_class(class), n)); 432 free(resp); 433 return (-1); 434 } 435 436 /* Remember the NS RRs and associated A RRs that came back. */ 437 if (save_ns(statp, &msg, ns_s_an, zname, class, opts, nsrrsp) < 0) { 438 DPRINTF(("get_ns save_ns('%s', %s) failed", 439 zname, p_class(class))); 440 free(resp); 441 return (-1); 442 } 443 444 free(resp); 445 return (0); 446 } 447 448 static int 449 get_glue(res_state statp, ns_class class, int opts, rrset_ns *nsrrsp) { 450 rr_ns *nsrr, *nsrr_n; 451 u_char *resp; 452 453 resp = malloc(NS_MAXMSG); 454 if (resp == NULL) 455 return(-1); 456 457 /* Go and get the A RRs for each empty NS RR on our list. */ 458 for (nsrr = HEAD(*nsrrsp); nsrr != NULL; nsrr = nsrr_n) { 459 ns_msg msg; 460 int n; 461 462 nsrr_n = NEXT(nsrr, link); 463 464 if ((nsrr->flags & RR_NS_HAVE_V4) == 0) { 465 n = do_query(statp, nsrr->name, class, ns_t_a, 466 resp, &msg); 467 if (n < 0) { 468 DPRINTF( 469 ("get_glue: do_query('%s', %s') failed", 470 nsrr->name, p_class(class))); 471 goto cleanup; 472 } 473 if (n > 0) { 474 DPRINTF(( 475 "get_glue: do_query('%s', %s') CNAME or DNAME found", 476 nsrr->name, p_class(class))); 477 } 478 if (save_a(statp, &msg, ns_s_an, nsrr->name, class, 479 opts, nsrr) < 0) { 480 DPRINTF(("get_glue: save_r('%s', %s) failed", 481 nsrr->name, p_class(class))); 482 goto cleanup; 483 } 484 } 485 486 if ((nsrr->flags & RR_NS_HAVE_V6) == 0) { 487 n = do_query(statp, nsrr->name, class, ns_t_aaaa, 488 resp, &msg); 489 if (n < 0) { 490 DPRINTF( 491 ("get_glue: do_query('%s', %s') failed", 492 nsrr->name, p_class(class))); 493 goto cleanup; 494 } 495 if (n > 0) { 496 DPRINTF(( 497 "get_glue: do_query('%s', %s') CNAME or DNAME found", 498 nsrr->name, p_class(class))); 499 } 500 if (save_a(statp, &msg, ns_s_an, nsrr->name, class, 501 opts, nsrr) < 0) { 502 DPRINTF(("get_glue: save_r('%s', %s) failed", 503 nsrr->name, p_class(class))); 504 goto cleanup; 505 } 506 } 507 508 /* If it's still empty, it's just chaff. */ 509 if (EMPTY(nsrr->addrs)) { 510 DPRINTF(("get_glue: removing empty '%s' NS", 511 nsrr->name)); 512 free_nsrr(nsrrsp, nsrr); 513 } 514 } 515 free(resp); 516 return (0); 517 518 cleanup: 519 free(resp); 520 return (-1); 521 } 522 523 static int 524 save_ns(res_state statp, ns_msg *msg, ns_sect sect, 525 const char *owner, ns_class class, int opts, 526 rrset_ns *nsrrsp) 527 { 528 int i; 529 530 for (i = 0; i < ns_msg_count(*msg, sect); i++) { 531 char tname[MAXDNAME]; 532 const u_char *rdata; 533 rr_ns *nsrr; 534 ns_rr rr; 535 536 if (ns_parserr(msg, sect, i, &rr) < 0) { 537 DPRINTF(("save_ns: ns_parserr(%s, %d) failed", 538 p_section(sect, ns_o_query), i)); 539 return (-1); 540 } 541 if (ns_rr_type(rr) != ns_t_ns || 542 ns_rr_class(rr) != class || 543 ns_samename(ns_rr_name(rr), owner) != 1) 544 continue; 545 nsrr = find_ns(nsrrsp, ns_rr_name(rr)); 546 if (nsrr == NULL) { 547 nsrr = malloc(sizeof *nsrr); 548 if (nsrr == NULL) { 549 DPRINTF(("save_ns: malloc failed")); 550 return (-1); 551 } 552 rdata = ns_rr_rdata(rr); 553 if (ns_name_uncompress(ns_msg_base(*msg), 554 ns_msg_end(*msg), rdata, 555 tname, sizeof tname) < 0) { 556 DPRINTF(("save_ns: ns_name_uncompress failed") 557 ); 558 free(nsrr); 559 return (-1); 560 } 561 nsrr->name = strdup(tname); 562 if (nsrr->name == NULL) { 563 DPRINTF(("save_ns: strdup failed")); 564 free(nsrr); 565 return (-1); 566 } 567 INIT_LINK(nsrr, link); 568 INIT_LIST(nsrr->addrs); 569 nsrr->flags = 0; 570 APPEND(*nsrrsp, nsrr, link); 571 } 572 if (save_a(statp, msg, ns_s_ar, 573 nsrr->name, class, opts, nsrr) < 0) { 574 DPRINTF(("save_ns: save_r('%s', %s) failed", 575 nsrr->name, p_class(class))); 576 return (-1); 577 } 578 } 579 return (0); 580 } 581 582 static int 583 save_a(res_state statp, ns_msg *msg, ns_sect sect, 584 const char *owner, ns_class class, int opts, 585 rr_ns *nsrr) 586 { 587 int i; 588 589 for (i = 0; i < ns_msg_count(*msg, sect); i++) { 590 ns_rr rr; 591 rr_a *arr; 592 593 if (ns_parserr(msg, sect, i, &rr) < 0) { 594 DPRINTF(("save_a: ns_parserr(%s, %d) failed", 595 p_section(sect, ns_o_query), i)); 596 return (-1); 597 } 598 if ((ns_rr_type(rr) != ns_t_a && 599 ns_rr_type(rr) != ns_t_aaaa) || 600 ns_rr_class(rr) != class || 601 ns_samename(ns_rr_name(rr), owner) != 1 || 602 ns_rr_rdlen(rr) != NS_INADDRSZ) 603 continue; 604 if ((opts & RES_IPV6ONLY) != 0 && ns_rr_type(rr) != ns_t_aaaa) 605 continue; 606 if ((opts & RES_IPV4ONLY) != 0 && ns_rr_type(rr) != ns_t_a) 607 continue; 608 arr = malloc(sizeof *arr); 609 if (arr == NULL) { 610 DPRINTF(("save_a: malloc failed")); 611 return (-1); 612 } 613 INIT_LINK(arr, link); 614 memset(&arr->addr, 0, sizeof(arr->addr)); 615 switch (ns_rr_type(rr)) { 616 case ns_t_a: 617 arr->addr.sin.sin_family = AF_INET; 618 #ifdef HAVE_SA_LEN 619 arr->addr.sin.sin_len = sizeof(arr->addr.sin); 620 #endif 621 memcpy(&arr->addr.sin.sin_addr, ns_rr_rdata(rr), 622 NS_INADDRSZ); 623 arr->addr.sin.sin_port = htons(NAMESERVER_PORT); 624 nsrr->flags |= RR_NS_HAVE_V4; 625 break; 626 case ns_t_aaaa: 627 arr->addr.sin6.sin6_family = AF_INET6; 628 #ifdef HAVE_SA_LEN 629 arr->addr.sin6.sin6_len = sizeof(arr->addr.sin6); 630 #endif 631 memcpy(&arr->addr.sin6.sin6_addr, ns_rr_rdata(rr), 16); 632 arr->addr.sin.sin_port = htons(NAMESERVER_PORT); 633 nsrr->flags |= RR_NS_HAVE_V6; 634 break; 635 default: 636 abort(); 637 } 638 APPEND(nsrr->addrs, arr, link); 639 } 640 return (0); 641 } 642 643 static void 644 free_nsrrset(rrset_ns *nsrrsp) { 645 rr_ns *nsrr; 646 647 while ((nsrr = HEAD(*nsrrsp)) != NULL) 648 free_nsrr(nsrrsp, nsrr); 649 } 650 651 static void 652 free_nsrr(rrset_ns *nsrrsp, rr_ns *nsrr) { 653 rr_a *arr; 654 char *tmp; 655 656 while ((arr = HEAD(nsrr->addrs)) != NULL) { 657 UNLINK(nsrr->addrs, arr, link); 658 free(arr); 659 } 660 DE_CONST(nsrr->name, tmp); 661 free(tmp); 662 UNLINK(*nsrrsp, nsrr, link); 663 free(nsrr); 664 } 665 666 static rr_ns * 667 find_ns(rrset_ns *nsrrsp, const char *dname) { 668 rr_ns *nsrr; 669 670 for (nsrr = HEAD(*nsrrsp); nsrr != NULL; nsrr = NEXT(nsrr, link)) 671 if (ns_samename(nsrr->name, dname) == 1) 672 return (nsrr); 673 return (NULL); 674 } 675 676 static int 677 do_query(res_state statp, const char *dname, ns_class class, ns_type qtype, 678 u_char *resp, ns_msg *msg) 679 { 680 u_char req[NS_PACKETSZ]; 681 int i, n; 682 683 n = res_nmkquery(statp, ns_o_query, dname, class, qtype, 684 NULL, 0, NULL, req, NS_PACKETSZ); 685 if (n < 0) { 686 DPRINTF(("do_query: res_nmkquery failed")); 687 return (-1); 688 } 689 n = res_nsend(statp, req, n, resp, NS_MAXMSG); 690 if (n < 0) { 691 DPRINTF(("do_query: res_nsend failed")); 692 return (-1); 693 } 694 if (n == 0) { 695 DPRINTF(("do_query: res_nsend returned 0")); 696 errno = EMSGSIZE; 697 return (-1); 698 } 699 if (ns_initparse(resp, n, msg) < 0) { 700 DPRINTF(("do_query: ns_initparse failed")); 701 return (-1); 702 } 703 n = 0; 704 for (i = 0; i < ns_msg_count(*msg, ns_s_an); i++) { 705 ns_rr rr; 706 707 if (ns_parserr(msg, ns_s_an, i, &rr) < 0) { 708 DPRINTF(("do_query: ns_parserr failed")); 709 return (-1); 710 } 711 n += (ns_rr_class(rr) == class && 712 (ns_rr_type(rr) == ns_t_cname || 713 ns_rr_type(rr) == ns_t_dname)); 714 } 715 return (n); 716 } 717 718 static void 719 res_dprintf(const char *fmt, ...) { 720 va_list ap; 721 722 va_start(ap, fmt); 723 fputs(";; res_findzonecut: ", stderr); 724 vfprintf(stderr, fmt, ap); 725 fputc('\n', stderr); 726 va_end(ap); 727 } 728 729 /*! \file */ 730