1 #if !defined(lint) && !defined(SABER) 2 static const char rcsid[] = "$Id: res_findzonecut.c,v 1.2.2.3.4.4 2005/10/11 00:48:16 marka Exp $"; 3 #endif /* not lint */ 4 5 /* 6 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 7 * Copyright (c) 1999 by Internet Software Consortium. 8 * 9 * Permission to use, copy, modify, and distribute this software for any 10 * purpose with or without fee is hereby granted, provided that the above 11 * copyright notice and this permission notice appear in all copies. 12 * 13 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 14 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 15 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 16 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 17 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 18 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 19 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 20 */ 21 22 /* Import. */ 23 24 #include "port_before.h" 25 26 #include <sys/param.h> 27 #include <sys/socket.h> 28 #include <sys/time.h> 29 30 #include <netinet/in.h> 31 #include <arpa/inet.h> 32 #include <arpa/nameser.h> 33 34 #include <errno.h> 35 #include <limits.h> 36 #include <netdb.h> 37 #include <stdarg.h> 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <string.h> 41 42 #include <isc/list.h> 43 44 #include "port_after.h" 45 46 #include <resolv.h> 47 48 /* Data structures. */ 49 50 typedef struct rr_a { 51 LINK(struct rr_a) link; 52 union res_sockaddr_union addr; 53 } rr_a; 54 typedef LIST(rr_a) rrset_a; 55 56 typedef struct rr_ns { 57 LINK(struct rr_ns) link; 58 const char * name; 59 unsigned int flags; 60 rrset_a addrs; 61 } rr_ns; 62 typedef LIST(rr_ns) rrset_ns; 63 64 #define RR_NS_HAVE_V4 0x01 65 #define RR_NS_HAVE_V6 0x02 66 67 /* Forward. */ 68 69 static int satisfy(res_state, const char *, rrset_ns *, 70 union res_sockaddr_union *, int); 71 static int add_addrs(res_state, rr_ns *, 72 union res_sockaddr_union *, int); 73 static int get_soa(res_state, const char *, ns_class, int, 74 char *, size_t, char *, size_t, 75 rrset_ns *); 76 static int get_ns(res_state, const char *, ns_class, int, rrset_ns *); 77 static int get_glue(res_state, ns_class, int, rrset_ns *); 78 static int save_ns(res_state, ns_msg *, ns_sect, 79 const char *, ns_class, int, rrset_ns *); 80 static int save_a(res_state, ns_msg *, ns_sect, 81 const char *, ns_class, int, rr_ns *); 82 static void free_nsrrset(rrset_ns *); 83 static void free_nsrr(rrset_ns *, rr_ns *); 84 static rr_ns * find_ns(rrset_ns *, const char *); 85 static int do_query(res_state, const char *, ns_class, ns_type, 86 u_char *, ns_msg *); 87 static void res_dprintf(const char *, ...) ISC_FORMAT_PRINTF(1, 2); 88 89 /* Macros. */ 90 91 #define DPRINTF(x) do {\ 92 int save_errno = errno; \ 93 if ((statp->options & RES_DEBUG) != 0U) res_dprintf x; \ 94 errno = save_errno; \ 95 } while (0) 96 97 /* Public. */ 98 99 /* 100 * int 101 * res_findzonecut(res, dname, class, zname, zsize, addrs, naddrs) 102 * find enclosing zone for a <dname,class>, and some server addresses 103 * parameters: 104 * res - resolver context to work within (is modified) 105 * dname - domain name whose enclosing zone is desired 106 * class - class of dname (and its enclosing zone) 107 * zname - found zone name 108 * zsize - allocated size of zname 109 * addrs - found server addresses 110 * naddrs - max number of addrs 111 * return values: 112 * < 0 - an error occurred (check errno) 113 * = 0 - zname is now valid, but addrs[] wasn't changed 114 * > 0 - zname is now valid, and return value is number of addrs[] found 115 * notes: 116 * this function calls res_nsend() which means it depends on correctly 117 * functioning recursive nameservers (usually defined in /etc/resolv.conf 118 * or its local equivilent). 119 * 120 * we start by asking for an SOA<dname,class>. if we get one as an 121 * answer, that just means <dname,class> is a zone top, which is fine. 122 * more than likely we'll be told to go pound sand, in the form of a 123 * negative answer. 124 * 125 * note that we are not prepared to deal with referrals since that would 126 * only come from authority servers and our correctly functioning local 127 * recursive server would have followed the referral and got us something 128 * more definite. 129 * 130 * if the authority section contains an SOA, this SOA should also be the 131 * closest enclosing zone, since any intermediary zone cuts would've been 132 * returned as referrals and dealt with by our correctly functioning local 133 * recursive name server. but an SOA in the authority section should NOT 134 * match our dname (since that would have been returned in the answer 135 * section). an authority section SOA has to be "above" our dname. 136 * 137 * however, since authority section SOA's were once optional, it's 138 * possible that we'll have to go hunting for the enclosing SOA by 139 * ripping labels off the front of our dname -- this is known as "doing 140 * it the hard way." 141 * 142 * ultimately we want some server addresses, which are ideally the ones 143 * pertaining to the SOA.MNAME, but only if there is a matching NS RR. 144 * so the second phase (after we find an SOA) is to go looking for the 145 * NS RRset for that SOA's zone. 146 * 147 * no answer section processed by this code is allowed to contain CNAME 148 * or DNAME RR's. for the SOA query this means we strip a label and 149 * keep going. for the NS and A queries this means we just give up. 150 */ 151 152 int 153 res_findzonecut(res_state statp, const char *dname, ns_class class, int opts, 154 char *zname, size_t zsize, struct in_addr *addrs, int naddrs) 155 { 156 int result, i; 157 union res_sockaddr_union *u; 158 159 160 opts |= RES_IPV4ONLY; 161 opts &= ~RES_IPV6ONLY; 162 163 u = calloc(naddrs, sizeof(*u)); 164 if (u == NULL) 165 return(-1); 166 167 result = res_findzonecut2(statp, dname, class, opts, zname, zsize, 168 u, naddrs); 169 170 for (i = 0; i < result; i++) { 171 addrs[i] = u[i].sin.sin_addr; 172 } 173 free(u); 174 return (result); 175 } 176 177 int 178 res_findzonecut2(res_state statp, const char *dname, ns_class class, int opts, 179 char *zname, size_t zsize, union res_sockaddr_union *addrs, 180 int naddrs) 181 { 182 char mname[NS_MAXDNAME]; 183 u_long save_pfcode; 184 rrset_ns nsrrs; 185 int n; 186 187 DPRINTF(("START dname='%s' class=%s, zsize=%ld, naddrs=%d", 188 dname, p_class(class), (long)zsize, naddrs)); 189 save_pfcode = statp->pfcode; 190 statp->pfcode |= RES_PRF_HEAD2 | RES_PRF_HEAD1 | RES_PRF_HEADX | 191 RES_PRF_QUES | RES_PRF_ANS | 192 RES_PRF_AUTH | RES_PRF_ADD; 193 INIT_LIST(nsrrs); 194 195 DPRINTF(("get the soa, and see if it has enough glue")); 196 if ((n = get_soa(statp, dname, class, opts, zname, zsize, 197 mname, sizeof mname, &nsrrs)) < 0 || 198 ((opts & RES_EXHAUSTIVE) == 0 && 199 (n = satisfy(statp, mname, &nsrrs, addrs, naddrs)) > 0)) 200 goto done; 201 202 DPRINTF(("get the ns rrset and see if it has enough glue")); 203 if ((n = get_ns(statp, zname, class, opts, &nsrrs)) < 0 || 204 ((opts & RES_EXHAUSTIVE) == 0 && 205 (n = satisfy(statp, mname, &nsrrs, addrs, naddrs)) > 0)) 206 goto done; 207 208 DPRINTF(("get the missing glue and see if it's finally enough")); 209 if ((n = get_glue(statp, class, opts, &nsrrs)) >= 0) 210 n = satisfy(statp, mname, &nsrrs, addrs, naddrs); 211 212 done: 213 DPRINTF(("FINISH n=%d (%s)", n, (n < 0) ? strerror(errno) : "OK")); 214 free_nsrrset(&nsrrs); 215 statp->pfcode = save_pfcode; 216 return (n); 217 } 218 219 /* Private. */ 220 221 static int 222 satisfy(res_state statp, const char *mname, rrset_ns *nsrrsp, 223 union res_sockaddr_union *addrs, int naddrs) 224 { 225 rr_ns *nsrr; 226 int n, x; 227 228 n = 0; 229 nsrr = find_ns(nsrrsp, mname); 230 if (nsrr != NULL) { 231 x = add_addrs(statp, nsrr, addrs, naddrs); 232 addrs += x; 233 naddrs -= x; 234 n += x; 235 } 236 for (nsrr = HEAD(*nsrrsp); 237 nsrr != NULL && naddrs > 0; 238 nsrr = NEXT(nsrr, link)) 239 if (ns_samename(nsrr->name, mname) != 1) { 240 x = add_addrs(statp, nsrr, addrs, naddrs); 241 addrs += x; 242 naddrs -= x; 243 n += x; 244 } 245 DPRINTF(("satisfy(%s): %d", mname, n)); 246 return (n); 247 } 248 249 static int 250 add_addrs(res_state statp, rr_ns *nsrr, 251 union res_sockaddr_union *addrs, int naddrs) 252 { 253 rr_a *arr; 254 int n = 0; 255 256 for (arr = HEAD(nsrr->addrs); arr != NULL; arr = NEXT(arr, link)) { 257 if (naddrs <= 0) 258 return (0); 259 *addrs++ = arr->addr; 260 naddrs--; 261 n++; 262 } 263 DPRINTF(("add_addrs: %d", n)); 264 return (n); 265 } 266 267 static int 268 get_soa(res_state statp, const char *dname, ns_class class, int opts, 269 char *zname, size_t zsize, char *mname, size_t msize, 270 rrset_ns *nsrrsp) 271 { 272 char tname[NS_MAXDNAME]; 273 u_char *resp = NULL; 274 int n, i, ancount, nscount; 275 ns_sect sect; 276 ns_msg msg; 277 u_int rcode; 278 279 /* 280 * Find closest enclosing SOA, even if it's for the root zone. 281 */ 282 283 /* First canonicalize dname (exactly one unescaped trailing "."). */ 284 if (ns_makecanon(dname, tname, sizeof tname) < 0) 285 goto cleanup; 286 dname = tname; 287 288 resp = malloc(NS_MAXMSG); 289 if (resp == NULL) 290 goto cleanup; 291 292 /* Now grovel the subdomains, hunting for an SOA answer or auth. */ 293 for (;;) { 294 /* Leading or inter-label '.' are skipped here. */ 295 while (*dname == '.') 296 dname++; 297 298 /* Is there an SOA? */ 299 n = do_query(statp, dname, class, ns_t_soa, resp, &msg); 300 if (n < 0) { 301 DPRINTF(("get_soa: do_query('%s', %s) failed (%d)", 302 dname, p_class(class), n)); 303 goto cleanup; 304 } 305 if (n > 0) { 306 DPRINTF(("get_soa: CNAME or DNAME found")); 307 sect = ns_s_max, n = 0; 308 } else { 309 rcode = ns_msg_getflag(msg, ns_f_rcode); 310 ancount = ns_msg_count(msg, ns_s_an); 311 nscount = ns_msg_count(msg, ns_s_ns); 312 if (ancount > 0 && rcode == ns_r_noerror) 313 sect = ns_s_an, n = ancount; 314 else if (nscount > 0) 315 sect = ns_s_ns, n = nscount; 316 else 317 sect = ns_s_max, n = 0; 318 } 319 for (i = 0; i < n; i++) { 320 const char *t; 321 const u_char *rdata; 322 ns_rr rr; 323 324 if (ns_parserr(&msg, sect, i, &rr) < 0) { 325 DPRINTF(("get_soa: ns_parserr(%s, %d) failed", 326 p_section(sect, ns_o_query), i)); 327 goto cleanup; 328 } 329 if (ns_rr_type(rr) == ns_t_cname || 330 ns_rr_type(rr) == ns_t_dname) 331 break; 332 if (ns_rr_type(rr) != ns_t_soa || 333 ns_rr_class(rr) != class) 334 continue; 335 t = ns_rr_name(rr); 336 switch (sect) { 337 case ns_s_an: 338 if (ns_samedomain(dname, t) == 0) { 339 DPRINTF( 340 ("get_soa: ns_samedomain('%s', '%s') == 0", 341 dname, t) 342 ); 343 errno = EPROTOTYPE; 344 goto cleanup; 345 } 346 break; 347 case ns_s_ns: 348 if (ns_samename(dname, t) == 1 || 349 ns_samedomain(dname, t) == 0) { 350 DPRINTF( 351 ("get_soa: ns_samename() || !ns_samedomain('%s', '%s')", 352 dname, t) 353 ); 354 errno = EPROTOTYPE; 355 goto cleanup; 356 } 357 break; 358 default: 359 abort(); 360 } 361 if (strlen(t) + 1 > zsize) { 362 DPRINTF(("get_soa: zname(%lu) too small (%lu)", 363 (unsigned long)zsize, 364 (unsigned long)strlen(t) + 1)); 365 errno = EMSGSIZE; 366 goto cleanup; 367 } 368 strcpy(zname, t); 369 rdata = ns_rr_rdata(rr); 370 if (ns_name_uncompress(resp, ns_msg_end(msg), rdata, 371 mname, msize) < 0) { 372 DPRINTF(("get_soa: ns_name_uncompress failed") 373 ); 374 goto cleanup; 375 } 376 if (save_ns(statp, &msg, ns_s_ns, 377 zname, class, opts, nsrrsp) < 0) { 378 DPRINTF(("get_soa: save_ns failed")); 379 goto cleanup; 380 } 381 free(resp); 382 return (0); 383 } 384 385 /* If we're out of labels, then not even "." has an SOA! */ 386 if (*dname == '\0') 387 break; 388 389 /* Find label-terminating "."; top of loop will skip it. */ 390 while (*dname != '.') { 391 if (*dname == '\\') 392 if (*++dname == '\0') { 393 errno = EMSGSIZE; 394 goto cleanup; 395 } 396 dname++; 397 } 398 } 399 DPRINTF(("get_soa: out of labels")); 400 errno = EDESTADDRREQ; 401 cleanup: 402 if (resp != NULL) 403 free(resp); 404 return (-1); 405 } 406 407 static int 408 get_ns(res_state statp, const char *zname, ns_class class, int opts, 409 rrset_ns *nsrrsp) 410 { 411 u_char *resp; 412 ns_msg msg; 413 int n; 414 415 resp = malloc(NS_MAXMSG); 416 if (resp == NULL) 417 return (-1); 418 419 /* Go and get the NS RRs for this zone. */ 420 n = do_query(statp, zname, class, ns_t_ns, resp, &msg); 421 if (n != 0) { 422 DPRINTF(("get_ns: do_query('%s', %s) failed (%d)", 423 zname, p_class(class), n)); 424 free(resp); 425 return (-1); 426 } 427 428 /* Remember the NS RRs and associated A RRs that came back. */ 429 if (save_ns(statp, &msg, ns_s_an, zname, class, opts, nsrrsp) < 0) { 430 DPRINTF(("get_ns save_ns('%s', %s) failed", 431 zname, p_class(class))); 432 free(resp); 433 return (-1); 434 } 435 436 free(resp); 437 return (0); 438 } 439 440 static int 441 get_glue(res_state statp, ns_class class, int opts, rrset_ns *nsrrsp) { 442 rr_ns *nsrr, *nsrr_n; 443 u_char *resp; 444 445 resp = malloc(NS_MAXMSG); 446 if (resp == NULL) 447 return(-1); 448 449 /* Go and get the A RRs for each empty NS RR on our list. */ 450 for (nsrr = HEAD(*nsrrsp); nsrr != NULL; nsrr = nsrr_n) { 451 ns_msg msg; 452 int n; 453 454 nsrr_n = NEXT(nsrr, link); 455 456 if ((nsrr->flags & RR_NS_HAVE_V4) == 0) { 457 n = do_query(statp, nsrr->name, class, ns_t_a, 458 resp, &msg); 459 if (n < 0) { 460 DPRINTF( 461 ("get_glue: do_query('%s', %s') failed", 462 nsrr->name, p_class(class))); 463 goto cleanup; 464 } 465 if (n > 0) { 466 DPRINTF(( 467 "get_glue: do_query('%s', %s') CNAME or DNAME found", 468 nsrr->name, p_class(class))); 469 } 470 if (save_a(statp, &msg, ns_s_an, nsrr->name, class, 471 opts, nsrr) < 0) { 472 DPRINTF(("get_glue: save_r('%s', %s) failed", 473 nsrr->name, p_class(class))); 474 goto cleanup; 475 } 476 } 477 478 if ((nsrr->flags & RR_NS_HAVE_V6) == 0) { 479 n = do_query(statp, nsrr->name, class, ns_t_aaaa, 480 resp, &msg); 481 if (n < 0) { 482 DPRINTF( 483 ("get_glue: do_query('%s', %s') failed", 484 nsrr->name, p_class(class))); 485 goto cleanup; 486 } 487 if (n > 0) { 488 DPRINTF(( 489 "get_glue: do_query('%s', %s') CNAME or DNAME found", 490 nsrr->name, p_class(class))); 491 } 492 if (save_a(statp, &msg, ns_s_an, nsrr->name, class, 493 opts, nsrr) < 0) { 494 DPRINTF(("get_glue: save_r('%s', %s) failed", 495 nsrr->name, p_class(class))); 496 goto cleanup; 497 } 498 } 499 500 /* If it's still empty, it's just chaff. */ 501 if (EMPTY(nsrr->addrs)) { 502 DPRINTF(("get_glue: removing empty '%s' NS", 503 nsrr->name)); 504 free_nsrr(nsrrsp, nsrr); 505 } 506 } 507 free(resp); 508 return (0); 509 510 cleanup: 511 free(resp); 512 return (-1); 513 } 514 515 static int 516 save_ns(res_state statp, ns_msg *msg, ns_sect sect, 517 const char *owner, ns_class class, int opts, 518 rrset_ns *nsrrsp) 519 { 520 int i; 521 522 for (i = 0; i < ns_msg_count(*msg, sect); i++) { 523 char tname[MAXDNAME]; 524 const u_char *rdata; 525 rr_ns *nsrr; 526 ns_rr rr; 527 528 if (ns_parserr(msg, sect, i, &rr) < 0) { 529 DPRINTF(("save_ns: ns_parserr(%s, %d) failed", 530 p_section(sect, ns_o_query), i)); 531 return (-1); 532 } 533 if (ns_rr_type(rr) != ns_t_ns || 534 ns_rr_class(rr) != class || 535 ns_samename(ns_rr_name(rr), owner) != 1) 536 continue; 537 nsrr = find_ns(nsrrsp, ns_rr_name(rr)); 538 if (nsrr == NULL) { 539 nsrr = malloc(sizeof *nsrr); 540 if (nsrr == NULL) { 541 DPRINTF(("save_ns: malloc failed")); 542 return (-1); 543 } 544 rdata = ns_rr_rdata(rr); 545 if (ns_name_uncompress(ns_msg_base(*msg), 546 ns_msg_end(*msg), rdata, 547 tname, sizeof tname) < 0) { 548 DPRINTF(("save_ns: ns_name_uncompress failed") 549 ); 550 free(nsrr); 551 return (-1); 552 } 553 nsrr->name = strdup(tname); 554 if (nsrr->name == NULL) { 555 DPRINTF(("save_ns: strdup failed")); 556 free(nsrr); 557 return (-1); 558 } 559 INIT_LINK(nsrr, link); 560 INIT_LIST(nsrr->addrs); 561 nsrr->flags = 0; 562 APPEND(*nsrrsp, nsrr, link); 563 } 564 if (save_a(statp, msg, ns_s_ar, 565 nsrr->name, class, opts, nsrr) < 0) { 566 DPRINTF(("save_ns: save_r('%s', %s) failed", 567 nsrr->name, p_class(class))); 568 return (-1); 569 } 570 } 571 return (0); 572 } 573 574 static int 575 save_a(res_state statp, ns_msg *msg, ns_sect sect, 576 const char *owner, ns_class class, int opts, 577 rr_ns *nsrr) 578 { 579 int i; 580 581 for (i = 0; i < ns_msg_count(*msg, sect); i++) { 582 ns_rr rr; 583 rr_a *arr; 584 585 if (ns_parserr(msg, sect, i, &rr) < 0) { 586 DPRINTF(("save_a: ns_parserr(%s, %d) failed", 587 p_section(sect, ns_o_query), i)); 588 return (-1); 589 } 590 if ((ns_rr_type(rr) != ns_t_a && 591 ns_rr_type(rr) != ns_t_aaaa) || 592 ns_rr_class(rr) != class || 593 ns_samename(ns_rr_name(rr), owner) != 1 || 594 ns_rr_rdlen(rr) != NS_INADDRSZ) 595 continue; 596 if ((opts & RES_IPV6ONLY) != 0 && ns_rr_type(rr) != ns_t_aaaa) 597 continue; 598 if ((opts & RES_IPV4ONLY) != 0 && ns_rr_type(rr) != ns_t_a) 599 continue; 600 arr = malloc(sizeof *arr); 601 if (arr == NULL) { 602 DPRINTF(("save_a: malloc failed")); 603 return (-1); 604 } 605 INIT_LINK(arr, link); 606 memset(&arr->addr, 0, sizeof(arr->addr)); 607 switch (ns_rr_type(rr)) { 608 case ns_t_a: 609 arr->addr.sin.sin_family = AF_INET; 610 #ifdef HAVE_SA_LEN 611 arr->addr.sin.sin_len = sizeof(arr->addr.sin); 612 #endif 613 memcpy(&arr->addr.sin.sin_addr, ns_rr_rdata(rr), 614 NS_INADDRSZ); 615 arr->addr.sin.sin_port = htons(NAMESERVER_PORT); 616 nsrr->flags |= RR_NS_HAVE_V4; 617 break; 618 case ns_t_aaaa: 619 arr->addr.sin6.sin6_family = AF_INET6; 620 #ifdef HAVE_SA_LEN 621 arr->addr.sin6.sin6_len = sizeof(arr->addr.sin6); 622 #endif 623 memcpy(&arr->addr.sin6.sin6_addr, ns_rr_rdata(rr), 16); 624 arr->addr.sin.sin_port = htons(NAMESERVER_PORT); 625 nsrr->flags |= RR_NS_HAVE_V6; 626 break; 627 default: 628 abort(); 629 } 630 APPEND(nsrr->addrs, arr, link); 631 } 632 return (0); 633 } 634 635 static void 636 free_nsrrset(rrset_ns *nsrrsp) { 637 rr_ns *nsrr; 638 639 while ((nsrr = HEAD(*nsrrsp)) != NULL) 640 free_nsrr(nsrrsp, nsrr); 641 } 642 643 static void 644 free_nsrr(rrset_ns *nsrrsp, rr_ns *nsrr) { 645 rr_a *arr; 646 char *tmp; 647 648 while ((arr = HEAD(nsrr->addrs)) != NULL) { 649 UNLINK(nsrr->addrs, arr, link); 650 free(arr); 651 } 652 DE_CONST(nsrr->name, tmp); 653 free(tmp); 654 UNLINK(*nsrrsp, nsrr, link); 655 free(nsrr); 656 } 657 658 static rr_ns * 659 find_ns(rrset_ns *nsrrsp, const char *dname) { 660 rr_ns *nsrr; 661 662 for (nsrr = HEAD(*nsrrsp); nsrr != NULL; nsrr = NEXT(nsrr, link)) 663 if (ns_samename(nsrr->name, dname) == 1) 664 return (nsrr); 665 return (NULL); 666 } 667 668 static int 669 do_query(res_state statp, const char *dname, ns_class class, ns_type qtype, 670 u_char *resp, ns_msg *msg) 671 { 672 u_char req[NS_PACKETSZ]; 673 int i, n; 674 675 n = res_nmkquery(statp, ns_o_query, dname, class, qtype, 676 NULL, 0, NULL, req, NS_PACKETSZ); 677 if (n < 0) { 678 DPRINTF(("do_query: res_nmkquery failed")); 679 return (-1); 680 } 681 n = res_nsend(statp, req, n, resp, NS_MAXMSG); 682 if (n < 0) { 683 DPRINTF(("do_query: res_nsend failed")); 684 return (-1); 685 } 686 if (n == 0) { 687 DPRINTF(("do_query: res_nsend returned 0")); 688 errno = EMSGSIZE; 689 return (-1); 690 } 691 if (ns_initparse(resp, n, msg) < 0) { 692 DPRINTF(("do_query: ns_initparse failed")); 693 return (-1); 694 } 695 n = 0; 696 for (i = 0; i < ns_msg_count(*msg, ns_s_an); i++) { 697 ns_rr rr; 698 699 if (ns_parserr(msg, ns_s_an, i, &rr) < 0) { 700 DPRINTF(("do_query: ns_parserr failed")); 701 return (-1); 702 } 703 n += (ns_rr_class(rr) == class && 704 (ns_rr_type(rr) == ns_t_cname || 705 ns_rr_type(rr) == ns_t_dname)); 706 } 707 return (n); 708 } 709 710 static void 711 res_dprintf(const char *fmt, ...) { 712 va_list ap; 713 714 va_start(ap, fmt); 715 fputs(";; res_findzonecut: ", stderr); 716 vfprintf(stderr, fmt, ap); 717 fputc('\n', stderr); 718 va_end(ap); 719 } 720