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