1 /* $OpenBSD: res_send_async.c,v 1.29 2015/10/23 00:52:09 deraadt Exp $ */ 2 /* 3 * Copyright (c) 2012 Eric Faurot <eric@openbsd.org> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #include <sys/types.h> 19 #include <sys/socket.h> 20 #include <sys/uio.h> 21 #include <netinet/in.h> 22 #include <arpa/nameser.h> 23 #include <netdb.h> 24 25 #include <asr.h> 26 #include <errno.h> 27 #include <fcntl.h> 28 #include <poll.h> 29 #include <resolv.h> /* for res_random */ 30 #include <stdlib.h> 31 #include <string.h> 32 #include <unistd.h> 33 34 #include "asr_private.h" 35 36 #define OP_QUERY (0) 37 38 static int res_send_async_run(struct asr_query *, struct asr_result *); 39 static int sockaddr_connect(const struct sockaddr *, int); 40 static int udp_send(struct asr_query *); 41 static int udp_recv(struct asr_query *); 42 static int tcp_write(struct asr_query *); 43 static int tcp_read(struct asr_query *); 44 static int validate_packet(struct asr_query *); 45 static int setup_query(struct asr_query *, const char *, const char *, int, int); 46 static int ensure_ibuf(struct asr_query *, size_t); 47 static int iter_ns(struct asr_query *); 48 49 #define AS_NS_SA(p) ((p)->as_ctx->ac_ns[(p)->as.dns.nsidx - 1]) 50 51 52 struct asr_query * 53 res_send_async(const unsigned char *buf, int buflen, void *asr) 54 { 55 struct asr_ctx *ac; 56 struct asr_query *as; 57 struct asr_unpack p; 58 struct asr_dns_header h; 59 struct asr_dns_query q; 60 61 DPRINT_PACKET("asr: res_send_async()", buf, buflen); 62 63 ac = _asr_use_resolver(asr); 64 if ((as = _asr_async_new(ac, ASR_SEND)) == NULL) { 65 _asr_ctx_unref(ac); 66 return (NULL); /* errno set */ 67 } 68 as->as_run = res_send_async_run; 69 70 as->as.dns.flags |= ASYNC_EXTOBUF; 71 as->as.dns.obuf = (unsigned char *)buf; 72 as->as.dns.obuflen = buflen; 73 as->as.dns.obufsize = buflen; 74 75 _asr_unpack_init(&p, buf, buflen); 76 _asr_unpack_header(&p, &h); 77 _asr_unpack_query(&p, &q); 78 if (p.err) { 79 errno = EINVAL; 80 goto err; 81 } 82 as->as.dns.reqid = h.id; 83 as->as.dns.type = q.q_type; 84 as->as.dns.class = q.q_class; 85 as->as.dns.dname = strdup(q.q_dname); 86 if (as->as.dns.dname == NULL) 87 goto err; /* errno set */ 88 89 _asr_ctx_unref(ac); 90 return (as); 91 err: 92 if (as) 93 _asr_async_free(as); 94 _asr_ctx_unref(ac); 95 return (NULL); 96 } 97 DEF_WEAK(res_send_async); 98 99 /* 100 * Unlike res_query(), this version will actually return the packet 101 * if it has received a valid one (errno == 0) even if h_errno is 102 * not NETDB_SUCCESS. So the packet *must* be freed if necessary. 103 */ 104 struct asr_query * 105 res_query_async(const char *name, int class, int type, void *asr) 106 { 107 struct asr_ctx *ac; 108 struct asr_query *as; 109 110 DPRINT("asr: res_query_async(\"%s\", %i, %i)\n", name, class, type); 111 112 ac = _asr_use_resolver(asr); 113 as = _res_query_async_ctx(name, class, type, ac); 114 _asr_ctx_unref(ac); 115 116 return (as); 117 } 118 DEF_WEAK(res_query_async); 119 120 struct asr_query * 121 _res_query_async_ctx(const char *name, int class, int type, struct asr_ctx *a_ctx) 122 { 123 struct asr_query *as; 124 125 DPRINT("asr: res_query_async_ctx(\"%s\", %i, %i)\n", name, class, type); 126 127 if ((as = _asr_async_new(a_ctx, ASR_SEND)) == NULL) 128 return (NULL); /* errno set */ 129 as->as_run = res_send_async_run; 130 131 /* This adds a "." to name if it doesn't already has one. 132 * That's how res_query() behaves (through res_mkquery"). 133 */ 134 if (setup_query(as, name, NULL, class, type) == -1) 135 goto err; /* errno set */ 136 137 return (as); 138 139 err: 140 if (as) 141 _asr_async_free(as); 142 143 return (NULL); 144 } 145 146 static int 147 res_send_async_run(struct asr_query *as, struct asr_result *ar) 148 { 149 next: 150 switch (as->as_state) { 151 152 case ASR_STATE_INIT: 153 154 if (as->as_ctx->ac_nscount == 0) { 155 ar->ar_errno = ECONNREFUSED; 156 async_set_state(as, ASR_STATE_HALT); 157 break; 158 } 159 160 async_set_state(as, ASR_STATE_NEXT_NS); 161 break; 162 163 case ASR_STATE_NEXT_NS: 164 165 if (iter_ns(as) == -1) { 166 ar->ar_errno = ETIMEDOUT; 167 async_set_state(as, ASR_STATE_HALT); 168 break; 169 } 170 171 if (as->as_ctx->ac_options & RES_USEVC || 172 as->as.dns.obuflen > PACKETSZ) 173 async_set_state(as, ASR_STATE_TCP_WRITE); 174 else 175 async_set_state(as, ASR_STATE_UDP_SEND); 176 break; 177 178 case ASR_STATE_UDP_SEND: 179 180 if (udp_send(as) == -1) { 181 async_set_state(as, ASR_STATE_NEXT_NS); 182 break; 183 } 184 async_set_state(as, ASR_STATE_UDP_RECV); 185 ar->ar_cond = ASR_WANT_READ; 186 ar->ar_fd = as->as_fd; 187 ar->ar_timeout = as->as_timeout; 188 return (ASYNC_COND); 189 break; 190 191 case ASR_STATE_UDP_RECV: 192 193 if (udp_recv(as) == -1) { 194 if (errno == ENOMEM) { 195 ar->ar_errno = errno; 196 async_set_state(as, ASR_STATE_HALT); 197 break; 198 } 199 if (errno != EOVERFLOW) { 200 /* Fail or timeout */ 201 async_set_state(as, ASR_STATE_NEXT_NS); 202 break; 203 } 204 if (as->as_ctx->ac_options & RES_IGNTC) 205 async_set_state(as, ASR_STATE_PACKET); 206 else 207 async_set_state(as, ASR_STATE_TCP_WRITE); 208 } else 209 async_set_state(as, ASR_STATE_PACKET); 210 break; 211 212 case ASR_STATE_TCP_WRITE: 213 214 switch (tcp_write(as)) { 215 case -1: /* fail or timeout */ 216 async_set_state(as, ASR_STATE_NEXT_NS); 217 break; 218 case 0: 219 async_set_state(as, ASR_STATE_TCP_READ); 220 ar->ar_cond = ASR_WANT_READ; 221 ar->ar_fd = as->as_fd; 222 ar->ar_timeout = as->as_timeout; 223 return (ASYNC_COND); 224 case 1: 225 ar->ar_cond = ASR_WANT_WRITE; 226 ar->ar_fd = as->as_fd; 227 ar->ar_timeout = as->as_timeout; 228 return (ASYNC_COND); 229 } 230 break; 231 232 case ASR_STATE_TCP_READ: 233 234 switch (tcp_read(as)) { 235 case -1: /* Fail or timeout */ 236 if (errno == ENOMEM) { 237 ar->ar_errno = errno; 238 async_set_state(as, ASR_STATE_HALT); 239 } else 240 async_set_state(as, ASR_STATE_NEXT_NS); 241 break; 242 case 0: 243 async_set_state(as, ASR_STATE_PACKET); 244 break; 245 case 1: 246 ar->ar_cond = ASR_WANT_READ; 247 ar->ar_fd = as->as_fd; 248 ar->ar_timeout = as->as_timeout; 249 return (ASYNC_COND); 250 } 251 break; 252 253 case ASR_STATE_PACKET: 254 255 memmove(&ar->ar_ns, AS_NS_SA(as), AS_NS_SA(as)->sa_len); 256 ar->ar_datalen = as->as.dns.ibuflen; 257 ar->ar_data = as->as.dns.ibuf; 258 as->as.dns.ibuf = NULL; 259 ar->ar_errno = 0; 260 ar->ar_rcode = as->as.dns.rcode; 261 async_set_state(as, ASR_STATE_HALT); 262 break; 263 264 case ASR_STATE_HALT: 265 266 if (ar->ar_errno) { 267 ar->ar_h_errno = TRY_AGAIN; 268 ar->ar_count = 0; 269 ar->ar_datalen = -1; 270 ar->ar_data = NULL; 271 } else if (as->as.dns.ancount) { 272 ar->ar_h_errno = NETDB_SUCCESS; 273 ar->ar_count = as->as.dns.ancount; 274 } else { 275 ar->ar_count = 0; 276 switch (as->as.dns.rcode) { 277 case NXDOMAIN: 278 ar->ar_h_errno = HOST_NOT_FOUND; 279 break; 280 case SERVFAIL: 281 ar->ar_h_errno = TRY_AGAIN; 282 break; 283 case NOERROR: 284 ar->ar_h_errno = NO_DATA; 285 break; 286 default: 287 ar->ar_h_errno = NO_RECOVERY; 288 } 289 } 290 return (ASYNC_DONE); 291 292 default: 293 294 ar->ar_errno = EOPNOTSUPP; 295 ar->ar_h_errno = NETDB_INTERNAL; 296 async_set_state(as, ASR_STATE_HALT); 297 break; 298 } 299 goto next; 300 } 301 302 static int 303 sockaddr_connect(const struct sockaddr *sa, int socktype) 304 { 305 int errno_save, sock; 306 307 if ((sock = socket(sa->sa_family, 308 socktype | SOCK_NONBLOCK | SOCK_DNS, 0)) == -1) 309 goto fail; 310 311 if (connect(sock, sa, sa->sa_len) == -1) { 312 /* 313 * In the TCP case, the caller will be asked to poll for 314 * POLLOUT so that we start writing the packet in tcp_write() 315 * when the connection is established, or fail there on error. 316 */ 317 if (errno == EINPROGRESS) 318 return (sock); 319 goto fail; 320 } 321 322 return (sock); 323 324 fail: 325 326 if (sock != -1) { 327 errno_save = errno; 328 close(sock); 329 errno = errno_save; 330 } 331 332 return (-1); 333 } 334 335 /* 336 * Prepare the DNS packet for the query type "type", class "class" and domain 337 * name created by the concatenation on "name" and "dom". 338 * Return 0 on success, set errno and return -1 on error. 339 */ 340 static int 341 setup_query(struct asr_query *as, const char *name, const char *dom, 342 int class, int type) 343 { 344 struct asr_pack p; 345 struct asr_dns_header h; 346 char fqdn[MAXDNAME]; 347 char dname[MAXDNAME]; 348 349 if (as->as.dns.flags & ASYNC_EXTOBUF) { 350 errno = EINVAL; 351 DPRINT("attempting to write in user packet"); 352 return (-1); 353 } 354 355 if (_asr_make_fqdn(name, dom, fqdn, sizeof(fqdn)) > sizeof(fqdn)) { 356 errno = EINVAL; 357 DPRINT("asr_make_fqdn: name too long\n"); 358 return (-1); 359 } 360 361 if (_asr_dname_from_fqdn(fqdn, dname, sizeof(dname)) == -1) { 362 errno = EINVAL; 363 DPRINT("asr_dname_from_fqdn: invalid\n"); 364 return (-1); 365 } 366 367 if (as->as.dns.obuf == NULL) { 368 as->as.dns.obufsize = PACKETSZ; 369 as->as.dns.obuf = malloc(as->as.dns.obufsize); 370 if (as->as.dns.obuf == NULL) 371 return (-1); /* errno set */ 372 } 373 as->as.dns.obuflen = 0; 374 375 memset(&h, 0, sizeof h); 376 h.id = res_randomid(); 377 if (as->as_ctx->ac_options & RES_RECURSE) 378 h.flags |= RD_MASK; 379 h.qdcount = 1; 380 381 _asr_pack_init(&p, as->as.dns.obuf, as->as.dns.obufsize); 382 _asr_pack_header(&p, &h); 383 _asr_pack_query(&p, type, class, dname); 384 if (p.err) { 385 DPRINT("error packing query"); 386 errno = EINVAL; 387 return (-1); 388 } 389 390 /* Remember the parameters. */ 391 as->as.dns.reqid = h.id; 392 as->as.dns.type = type; 393 as->as.dns.class = class; 394 if (as->as.dns.dname) 395 free(as->as.dns.dname); 396 as->as.dns.dname = strdup(dname); 397 if (as->as.dns.dname == NULL) { 398 DPRINT("strdup"); 399 return (-1); /* errno set */ 400 } 401 as->as.dns.obuflen = p.offset; 402 403 DPRINT_PACKET("asr_setup_query", as->as.dns.obuf, as->as.dns.obuflen); 404 405 return (0); 406 } 407 408 /* 409 * Create a connect UDP socket and send the output packet. 410 * 411 * Return 0 on success, or -1 on error (errno set). 412 */ 413 static int 414 udp_send(struct asr_query *as) 415 { 416 ssize_t n; 417 int save_errno; 418 #ifdef DEBUG 419 char buf[256]; 420 #endif 421 422 DPRINT("asr: [%p] connecting to %s UDP\n", as, 423 _asr_print_sockaddr(AS_NS_SA(as), buf, sizeof buf)); 424 425 as->as_fd = sockaddr_connect(AS_NS_SA(as), SOCK_DGRAM); 426 if (as->as_fd == -1) 427 return (-1); /* errno set */ 428 429 n = send(as->as_fd, as->as.dns.obuf, as->as.dns.obuflen, 0); 430 if (n == -1) { 431 save_errno = errno; 432 close(as->as_fd); 433 errno = save_errno; 434 as->as_fd = -1; 435 return (-1); 436 } 437 438 return (0); 439 } 440 441 /* 442 * Try to receive a valid packet from the current UDP socket. 443 * 444 * Return 0 if a full packet could be read, or -1 on error (errno set). 445 */ 446 static int 447 udp_recv(struct asr_query *as) 448 { 449 ssize_t n; 450 int save_errno; 451 452 if (ensure_ibuf(as, PACKETSZ) == -1) { 453 save_errno = errno; 454 close(as->as_fd); 455 errno = save_errno; 456 as->as_fd = -1; 457 return (-1); 458 } 459 460 n = recv(as->as_fd, as->as.dns.ibuf, as->as.dns.ibufsize, 0); 461 save_errno = errno; 462 close(as->as_fd); 463 errno = save_errno; 464 as->as_fd = -1; 465 if (n == -1) 466 return (-1); 467 468 as->as.dns.ibuflen = n; 469 470 DPRINT_PACKET("asr_udp_recv()", as->as.dns.ibuf, as->as.dns.ibuflen); 471 472 if (validate_packet(as) == -1) 473 return (-1); /* errno set */ 474 475 return (0); 476 } 477 478 /* 479 * Write the output packet to the TCP socket. 480 * 481 * Return 0 when all bytes have been sent, 1 there is no buffer space on the 482 * socket or it is not connected yet, or -1 on error (errno set). 483 */ 484 static int 485 tcp_write(struct asr_query *as) 486 { 487 struct msghdr msg; 488 struct iovec iov[2]; 489 uint16_t len; 490 ssize_t n; 491 size_t offset; 492 int i; 493 #ifdef DEBUG 494 char buf[256]; 495 #endif 496 497 /* First try to connect if not already */ 498 if (as->as_fd == -1) { 499 DPRINT("asr: [%p] connecting to %s TCP\n", as, 500 _asr_print_sockaddr(AS_NS_SA(as), buf, sizeof buf)); 501 as->as_fd = sockaddr_connect(AS_NS_SA(as), SOCK_STREAM); 502 if (as->as_fd == -1) 503 return (-1); /* errno set */ 504 as->as.dns.datalen = 0; /* bytes sent */ 505 return (1); 506 } 507 508 i = 0; 509 510 /* Prepend de packet length if not sent already. */ 511 if (as->as.dns.datalen < sizeof(len)) { 512 offset = 0; 513 len = htons(as->as.dns.obuflen); 514 iov[i].iov_base = (char *)(&len) + as->as.dns.datalen; 515 iov[i].iov_len = sizeof(len) - as->as.dns.datalen; 516 i++; 517 } else 518 offset = as->as.dns.datalen - sizeof(len); 519 520 iov[i].iov_base = as->as.dns.obuf + offset; 521 iov[i].iov_len = as->as.dns.obuflen - offset; 522 i++; 523 524 memset(&msg, 0, sizeof msg); 525 msg.msg_iov = iov; 526 msg.msg_iovlen = i; 527 528 send_again: 529 n = sendmsg(as->as_fd, &msg, MSG_NOSIGNAL); 530 if (n == -1) { 531 if (errno == EINTR) 532 goto send_again; 533 goto close; /* errno set */ 534 } 535 536 as->as.dns.datalen += n; 537 538 if (as->as.dns.datalen == as->as.dns.obuflen + sizeof(len)) { 539 /* All sent. Prepare for TCP read */ 540 as->as.dns.datalen = 0; 541 return (0); 542 } 543 544 /* More data to write */ 545 return (1); 546 547 close: 548 close(as->as_fd); 549 as->as_fd = -1; 550 return (-1); 551 } 552 553 /* 554 * Try to read a valid packet from the current TCP socket. 555 * 556 * Return 0 if a full packet could be read, 1 if more data is needed and the 557 * socket must be read again, or -1 on error (errno set). 558 */ 559 static int 560 tcp_read(struct asr_query *as) 561 { 562 ssize_t n; 563 size_t offset, len; 564 char *pos; 565 int save_errno, nfds; 566 struct pollfd pfd; 567 568 /* We must read the packet len first */ 569 if (as->as.dns.datalen < sizeof(as->as.dns.pktlen)) { 570 571 pos = (char *)(&as->as.dns.pktlen) + as->as.dns.datalen; 572 len = sizeof(as->as.dns.pktlen) - as->as.dns.datalen; 573 574 n = read(as->as_fd, pos, len); 575 if (n == -1) 576 goto close; /* errno set */ 577 578 as->as.dns.datalen += n; 579 if (as->as.dns.datalen < sizeof(as->as.dns.pktlen)) 580 return (1); /* need more data */ 581 582 as->as.dns.ibuflen = ntohs(as->as.dns.pktlen); 583 if (ensure_ibuf(as, as->as.dns.ibuflen) == -1) 584 goto close; /* errno set */ 585 586 pfd.fd = as->as_fd; 587 pfd.events = POLLIN; 588 poll_again: 589 nfds = poll(&pfd, 1, 0); 590 if (nfds == -1) { 591 if (errno == EINTR) 592 goto poll_again; 593 goto close; /* errno set */ 594 } 595 if (nfds == 0) 596 return (1); /* no more data available */ 597 } 598 599 offset = as->as.dns.datalen - sizeof(as->as.dns.pktlen); 600 pos = as->as.dns.ibuf + offset; 601 len = as->as.dns.ibuflen - offset; 602 603 read_again: 604 n = read(as->as_fd, pos, len); 605 if (n == -1) { 606 if (errno == EINTR) 607 goto read_again; 608 goto close; /* errno set */ 609 } 610 if (n == 0) { 611 errno = ECONNRESET; 612 goto close; 613 } 614 as->as.dns.datalen += n; 615 616 /* See if we got all the advertised bytes. */ 617 if (as->as.dns.datalen != as->as.dns.ibuflen + sizeof(as->as.dns.pktlen)) 618 return (1); 619 620 DPRINT_PACKET("asr_tcp_read()", as->as.dns.ibuf, as->as.dns.ibuflen); 621 622 if (validate_packet(as) == -1) 623 goto close; /* errno set */ 624 625 errno = 0; 626 close: 627 save_errno = errno; 628 close(as->as_fd); 629 errno = save_errno; 630 as->as_fd = -1; 631 return (errno ? -1 : 0); 632 } 633 634 /* 635 * Make sure the input buffer is at least "n" bytes long, and allocate or 636 * extend it if necessary. Return 0 on success, or set errno and return -1. 637 */ 638 static int 639 ensure_ibuf(struct asr_query *as, size_t n) 640 { 641 char *t; 642 643 if (as->as.dns.ibuf == NULL) { 644 as->as.dns.ibuf = malloc(n); 645 if (as->as.dns.ibuf == NULL) 646 return (-1); /* errno set */ 647 as->as.dns.ibufsize = n; 648 return (0); 649 } 650 651 if (as->as.dns.ibufsize >= n) 652 return (0); 653 654 t = realloc(as->as.dns.ibuf, n); 655 if (t == NULL) 656 return (-1); /* errno set */ 657 as->as.dns.ibuf = t; 658 as->as.dns.ibufsize = n; 659 660 return (0); 661 } 662 663 /* 664 * Check if the received packet is valid. 665 * Return 0 on success, or set errno and return -1. 666 */ 667 static int 668 validate_packet(struct asr_query *as) 669 { 670 struct asr_unpack p; 671 struct asr_dns_header h; 672 struct asr_dns_query q; 673 struct asr_dns_rr rr; 674 int r; 675 676 _asr_unpack_init(&p, as->as.dns.ibuf, as->as.dns.ibuflen); 677 678 _asr_unpack_header(&p, &h); 679 if (p.err) 680 goto inval; 681 682 if (h.id != as->as.dns.reqid) { 683 DPRINT("incorrect reqid\n"); 684 goto inval; 685 } 686 if (h.qdcount != 1) 687 goto inval; 688 /* Should be zero, we could allow this */ 689 if ((h.flags & Z_MASK) != 0) 690 goto inval; 691 /* Actually, it depends on the request but we only use OP_QUERY */ 692 if (OPCODE(h.flags) != OP_QUERY) 693 goto inval; 694 /* Must be a response */ 695 if ((h.flags & QR_MASK) == 0) 696 goto inval; 697 698 as->as.dns.rcode = RCODE(h.flags); 699 as->as.dns.ancount = h.ancount; 700 701 _asr_unpack_query(&p, &q); 702 if (p.err) 703 goto inval; 704 705 if (q.q_type != as->as.dns.type || 706 q.q_class != as->as.dns.class || 707 strcasecmp(q.q_dname, as->as.dns.dname)) { 708 DPRINT("incorrect type/class/dname '%s' != '%s'\n", 709 q.q_dname, as->as.dns.dname); 710 goto inval; 711 } 712 713 /* Check for truncation */ 714 if (h.flags & TC_MASK) { 715 errno = EOVERFLOW; 716 return (-1); 717 } 718 719 /* Validate the rest of the packet */ 720 for (r = h.ancount + h.nscount + h.arcount; r; r--) 721 _asr_unpack_rr(&p, &rr); 722 723 if (p.err || (p.offset != as->as.dns.ibuflen)) 724 goto inval; 725 726 return (0); 727 728 inval: 729 errno = EINVAL; 730 return (-1); 731 } 732 733 /* 734 * Set the async context nameserver index to the next nameserver, cycling 735 * over the list until the maximum retry counter is reached. Return 0 on 736 * success, or -1 if all nameservers were used. 737 */ 738 static int 739 iter_ns(struct asr_query *as) 740 { 741 for (;;) { 742 if (as->as.dns.nsloop >= as->as_ctx->ac_nsretries) 743 return (-1); 744 745 as->as.dns.nsidx += 1; 746 if (as->as.dns.nsidx <= as->as_ctx->ac_nscount) 747 break; 748 as->as.dns.nsidx = 0; 749 as->as.dns.nsloop++; 750 DPRINT("asr: iter_ns(): cycle %i\n", as->as.dns.nsloop); 751 } 752 753 as->as_timeout = 1000 * (as->as_ctx->ac_nstimeout << as->as.dns.nsloop); 754 if (as->as.dns.nsloop > 0) 755 as->as_timeout /= as->as_ctx->ac_nscount; 756 if (as->as_timeout < 1000) 757 as->as_timeout = 1000; 758 759 return (0); 760 } 761