1 /* 2 * Copyright (c) 1995, 1996, 1998 Theo de Raadt. All rights reserved. 3 * Copyright (c) 1983, 1993, 1994 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #if defined(LIBC_SCCS) && !defined(lint) 29 static char *rcsid = "$OpenBSD: rcmd.c,v 1.46 2003/06/03 20:49:27 deraadt Exp $"; 30 #endif /* LIBC_SCCS and not lint */ 31 32 #include <sys/param.h> 33 #include <sys/socket.h> 34 #include <sys/stat.h> 35 36 #include <netinet/in.h> 37 #include <arpa/inet.h> 38 39 #include <signal.h> 40 #include <fcntl.h> 41 #include <netdb.h> 42 #include <unistd.h> 43 #include <pwd.h> 44 #include <errno.h> 45 #include <stdio.h> 46 #include <ctype.h> 47 #include <string.h> 48 #include <syslog.h> 49 #include <stdlib.h> 50 #include <netgroup.h> 51 52 int __ivaliduser(FILE *, in_addr_t, const char *, const char *); 53 int __ivaliduser_sa(FILE *, struct sockaddr *, socklen_t, 54 const char *, const char *); 55 static int __icheckhost(struct sockaddr *, socklen_t, const char *); 56 static char *__gethostloop(struct sockaddr *, socklen_t); 57 58 int 59 rcmd(ahost, rport, locuser, remuser, cmd, fd2p) 60 char **ahost; 61 in_port_t rport; 62 const char *locuser, *remuser, *cmd; 63 int *fd2p; 64 { 65 return rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, AF_INET); 66 } 67 68 int 69 rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, af) 70 char **ahost; 71 in_port_t rport; 72 const char *locuser, *remuser, *cmd; 73 int *fd2p; 74 int af; 75 { 76 static char hbuf[MAXHOSTNAMELEN]; 77 char pbuf[NI_MAXSERV]; 78 struct addrinfo hints, *res, *r; 79 int error; 80 struct sockaddr_storage from; 81 fd_set *readsp = NULL; 82 sigset_t oldmask, mask; 83 pid_t pid; 84 int s, lport, timo; 85 char c, *p; 86 int refused; 87 88 /* call rcmdsh() with specified remote shell if appropriate. */ 89 if (!issetugid() && (p = getenv("RSH")) && *p) { 90 struct servent *sp = getservbyname("shell", "tcp"); 91 92 if (sp && sp->s_port == rport) 93 return (rcmdsh(ahost, rport, locuser, remuser, 94 cmd, p)); 95 } 96 97 /* use rsh(1) if non-root and remote port is shell. */ 98 if (geteuid()) { 99 struct servent *sp = getservbyname("shell", "tcp"); 100 101 if (sp && sp->s_port == rport) 102 return (rcmdsh(ahost, rport, locuser, remuser, 103 cmd, NULL)); 104 } 105 106 pid = getpid(); 107 snprintf(pbuf, sizeof(pbuf), "%u", ntohs(rport)); 108 memset(&hints, 0, sizeof(hints)); 109 hints.ai_family = af; 110 hints.ai_socktype = SOCK_STREAM; 111 hints.ai_flags = AI_CANONNAME; 112 error = getaddrinfo(*ahost, pbuf, &hints, &res); 113 if (error) { 114 #if 0 115 warnx("%s: %s", *ahost, gai_strerror(error)); 116 #endif 117 return (-1); 118 } 119 if (res->ai_canonname) { 120 strlcpy(hbuf, res->ai_canonname, sizeof(hbuf)); 121 *ahost = hbuf; 122 } else 123 ; /*XXX*/ 124 125 r = res; 126 refused = 0; 127 sigemptyset(&mask); 128 sigaddset(&mask, SIGURG); 129 oldmask = sigprocmask(SIG_BLOCK, &mask, &oldmask); 130 for (timo = 1, lport = IPPORT_RESERVED - 1;;) { 131 s = rresvport_af(&lport, r->ai_family); 132 if (s < 0) { 133 if (errno == EAGAIN) 134 (void)fprintf(stderr, 135 "rcmd: socket: All ports in use\n"); 136 else 137 (void)fprintf(stderr, "rcmd: socket: %s\n", 138 strerror(errno)); 139 if (r->ai_next) { 140 r = r->ai_next; 141 continue; 142 } else { 143 sigprocmask(SIG_SETMASK, &oldmask, NULL); 144 freeaddrinfo(res); 145 return (-1); 146 } 147 } 148 fcntl(s, F_SETOWN, pid); 149 if (connect(s, r->ai_addr, r->ai_addrlen) >= 0) 150 break; 151 (void)close(s); 152 if (errno == EADDRINUSE) { 153 lport--; 154 continue; 155 } 156 if (errno == ECONNREFUSED) 157 refused++; 158 if (r->ai_next) { 159 int oerrno = errno; 160 char hbuf[NI_MAXHOST]; 161 #ifdef NI_WITHSCOPEID 162 const int niflags = NI_NUMERICHOST | NI_WITHSCOPEID; 163 #else 164 const int niflags = NI_NUMERICHOST; 165 #endif 166 167 hbuf[0] = '\0'; 168 if (getnameinfo(r->ai_addr, r->ai_addrlen, 169 hbuf, sizeof(hbuf), NULL, 0, niflags) != 0) 170 strlcpy(hbuf, "(invalid)", sizeof hbuf); 171 (void)fprintf(stderr, "connect to address %s: ", hbuf); 172 errno = oerrno; 173 perror(0); 174 r = r->ai_next; 175 hbuf[0] = '\0'; 176 if (getnameinfo(r->ai_addr, r->ai_addrlen, 177 hbuf, sizeof(hbuf), NULL, 0, niflags) != 0) 178 strlcpy(hbuf, "(invalid)", sizeof hbuf); 179 (void)fprintf(stderr, "Trying %s...\n", hbuf); 180 continue; 181 } 182 if (refused && timo <= 16) { 183 (void)sleep(timo); 184 timo *= 2; 185 r = res; 186 refused = 0; 187 continue; 188 } 189 (void)fprintf(stderr, "%s: %s\n", res->ai_canonname, 190 strerror(errno)); 191 sigprocmask(SIG_SETMASK, &oldmask, NULL); 192 freeaddrinfo(res); 193 return (-1); 194 } 195 /* given "af" can be PF_UNSPEC, we need the real af for "s" */ 196 af = r->ai_family; 197 freeaddrinfo(res); 198 #if 0 199 /* 200 * try to rresvport() to the same port. This will make rresvport() 201 * fail it's first bind, resulting in it choosing a random port. 202 */ 203 lport--; 204 #endif 205 if (fd2p == 0) { 206 write(s, "", 1); 207 lport = 0; 208 } else { 209 char num[8]; 210 int s2 = rresvport_af(&lport, af), s3; 211 socklen_t len = sizeof(from); 212 int fdssize = howmany(MAX(s, s2)+1, NFDBITS) * sizeof(fd_mask); 213 214 if (s2 < 0) 215 goto bad; 216 readsp = (fd_set *)malloc(fdssize); 217 if (readsp == NULL) 218 goto bad; 219 listen(s2, 1); 220 (void)snprintf(num, sizeof(num), "%d", lport); 221 if (write(s, num, strlen(num)+1) != strlen(num)+1) { 222 (void)fprintf(stderr, 223 "rcmd: write (setting up stderr): %s\n", 224 strerror(errno)); 225 (void)close(s2); 226 goto bad; 227 } 228 again: 229 bzero(readsp, fdssize); 230 FD_SET(s, readsp); 231 FD_SET(s2, readsp); 232 errno = 0; 233 if (select(MAX(s, s2) + 1, readsp, 0, 0, 0) < 1 || 234 !FD_ISSET(s2, readsp)) { 235 if (errno != 0) 236 (void)fprintf(stderr, 237 "rcmd: select (setting up stderr): %s\n", 238 strerror(errno)); 239 else 240 (void)fprintf(stderr, 241 "select: protocol failure in circuit setup\n"); 242 (void)close(s2); 243 goto bad; 244 } 245 s3 = accept(s2, (struct sockaddr *)&from, &len); 246 /* 247 * XXX careful for ftp bounce attacks. If discovered, shut them 248 * down and check for the real auxiliary channel to connect. 249 */ 250 switch (from.ss_family) { 251 case AF_INET: 252 case AF_INET6: 253 if (getnameinfo((struct sockaddr *)&from, len, 254 NULL, 0, num, sizeof(num), NI_NUMERICSERV) == 0 && 255 atoi(num) != 20) { 256 break; 257 } 258 close(s3); 259 goto again; 260 default: 261 break; 262 } 263 (void)close(s2); 264 if (s3 < 0) { 265 (void)fprintf(stderr, 266 "rcmd: accept: %s\n", strerror(errno)); 267 lport = 0; 268 goto bad; 269 } 270 *fd2p = s3; 271 switch (from.ss_family) { 272 case AF_INET: 273 case AF_INET6: 274 if (getnameinfo((struct sockaddr *)&from, len, 275 NULL, 0, num, sizeof(num), NI_NUMERICSERV) != 0 || 276 (atoi(num) >= IPPORT_RESERVED || 277 atoi(num) < IPPORT_RESERVED / 2)) { 278 (void)fprintf(stderr, 279 "socket: protocol failure in circuit setup.\n"); 280 goto bad2; 281 } 282 break; 283 default: 284 break; 285 } 286 } 287 (void)write(s, locuser, strlen(locuser)+1); 288 (void)write(s, remuser, strlen(remuser)+1); 289 (void)write(s, cmd, strlen(cmd)+1); 290 if (read(s, &c, 1) != 1) { 291 (void)fprintf(stderr, 292 "rcmd: %s: %s\n", *ahost, strerror(errno)); 293 goto bad2; 294 } 295 if (c != 0) { 296 while (read(s, &c, 1) == 1) { 297 (void)write(STDERR_FILENO, &c, 1); 298 if (c == '\n') 299 break; 300 } 301 goto bad2; 302 } 303 sigprocmask(SIG_SETMASK, &oldmask, NULL); 304 free(readsp); 305 return (s); 306 bad2: 307 if (lport) 308 (void)close(*fd2p); 309 bad: 310 if (readsp) 311 free(readsp); 312 (void)close(s); 313 sigprocmask(SIG_SETMASK, &oldmask, NULL); 314 return (-1); 315 } 316 317 int __check_rhosts_file = 1; 318 char *__rcmd_errstr; 319 320 int 321 ruserok(rhost, superuser, ruser, luser) 322 const char *rhost, *ruser, *luser; 323 int superuser; 324 { 325 struct addrinfo hints, *res, *r; 326 int error; 327 328 memset(&hints, 0, sizeof(hints)); 329 hints.ai_family = PF_UNSPEC; 330 hints.ai_socktype = SOCK_DGRAM; /*dummy*/ 331 error = getaddrinfo(rhost, "0", &hints, &res); 332 if (error) 333 return (-1); 334 335 for (r = res; r; r = r->ai_next) { 336 if (iruserok_sa(r->ai_addr, r->ai_addrlen, superuser, ruser, 337 luser) == 0) { 338 freeaddrinfo(res); 339 return (0); 340 } 341 } 342 freeaddrinfo(res); 343 return (-1); 344 } 345 346 /* 347 * New .rhosts strategy: We are passed an ip address. We spin through 348 * hosts.equiv and .rhosts looking for a match. When the .rhosts only 349 * has ip addresses, we don't have to trust a nameserver. When it 350 * contains hostnames, we spin through the list of addresses the nameserver 351 * gives us and look for a match. 352 * 353 * Returns 0 if ok, -1 if not ok. 354 */ 355 int 356 iruserok(raddr, superuser, ruser, luser) 357 u_int32_t raddr; 358 int superuser; 359 const char *ruser, *luser; 360 { 361 struct sockaddr_in sin; 362 363 memset(&sin, 0, sizeof(sin)); 364 sin.sin_family = AF_INET; 365 sin.sin_len = sizeof(struct sockaddr_in); 366 memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr)); 367 return iruserok_sa(&sin, sizeof(struct sockaddr_in), superuser, ruser, 368 luser); 369 } 370 371 int 372 iruserok_sa(raddr, rlen, superuser, ruser, luser) 373 const void *raddr; 374 int rlen; 375 int superuser; 376 const char *ruser, *luser; 377 { 378 struct sockaddr *sa; 379 register char *cp; 380 struct stat sbuf; 381 struct passwd *pwd; 382 FILE *hostf; 383 uid_t uid; 384 int first; 385 char pbuf[MAXPATHLEN]; 386 387 sa = (struct sockaddr *)raddr; 388 first = 1; 389 hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r"); 390 again: 391 if (hostf) { 392 if (__ivaliduser_sa(hostf, sa, rlen, luser, ruser) == 0) { 393 (void)fclose(hostf); 394 return (0); 395 } 396 (void)fclose(hostf); 397 } 398 if (first == 1 && (__check_rhosts_file || superuser)) { 399 first = 0; 400 if ((pwd = getpwnam(luser)) == NULL) 401 return (-1); 402 snprintf(pbuf, sizeof pbuf, "%s/.rhosts", pwd->pw_dir); 403 404 /* 405 * Change effective uid while opening .rhosts. If root and 406 * reading an NFS mounted file system, can't read files that 407 * are protected read/write owner only. 408 */ 409 uid = geteuid(); 410 (void)seteuid(pwd->pw_uid); 411 hostf = fopen(pbuf, "r"); 412 (void)seteuid(uid); 413 414 if (hostf == NULL) 415 return (-1); 416 /* 417 * If not a regular file, or is owned by someone other than 418 * user or root or if writeable by anyone but the owner, quit. 419 */ 420 cp = NULL; 421 if (lstat(pbuf, &sbuf) < 0) 422 cp = ".rhosts lstat failed"; 423 else if (!S_ISREG(sbuf.st_mode)) 424 cp = ".rhosts not regular file"; 425 else if (fstat(fileno(hostf), &sbuf) < 0) 426 cp = ".rhosts fstat failed"; 427 else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid) 428 cp = "bad .rhosts owner"; 429 else if (sbuf.st_mode & (S_IWGRP|S_IWOTH)) 430 cp = ".rhosts writable by other than owner"; 431 /* If there were any problems, quit. */ 432 if (cp) { 433 __rcmd_errstr = cp; 434 (void)fclose(hostf); 435 return (-1); 436 } 437 goto again; 438 } 439 return (-1); 440 } 441 442 /* 443 * XXX 444 * Don't make static, used by lpd(8). 445 * 446 * Returns 0 if ok, -1 if not ok. 447 */ 448 int 449 __ivaliduser(hostf, raddrl, luser, ruser) 450 FILE *hostf; 451 in_addr_t raddrl; 452 const char *luser, *ruser; 453 { 454 struct sockaddr_in sin; 455 456 memset(&sin, 0, sizeof(sin)); 457 sin.sin_family = AF_INET; 458 sin.sin_len = sizeof(struct sockaddr_in); 459 memcpy(&sin.sin_addr, &raddrl, sizeof(sin.sin_addr)); 460 return __ivaliduser_sa(hostf, (struct sockaddr *)&sin, sin.sin_len, 461 luser, ruser); 462 } 463 464 int 465 __ivaliduser_sa(hostf, raddr, salen, luser, ruser) 466 FILE *hostf; 467 struct sockaddr *raddr; 468 socklen_t salen; 469 const char *luser, *ruser; 470 { 471 register char *user, *p; 472 char *buf; 473 const char *auser, *ahost; 474 int hostok, userok; 475 char *rhost = (char *)-1; 476 char domain[MAXHOSTNAMELEN]; 477 size_t buflen; 478 479 getdomainname(domain, sizeof(domain)); 480 481 while ((buf = fgetln(hostf, &buflen))) { 482 p = buf; 483 if (*p == '#') 484 continue; 485 while (*p != '\n' && *p != ' ' && *p != '\t' && p < buf + buflen) { 486 if (!isprint(*p)) 487 goto bail; 488 *p = isupper(*p) ? tolower(*p) : *p; 489 p++; 490 } 491 if (p >= buf + buflen) 492 continue; 493 if (*p == ' ' || *p == '\t') { 494 *p++ = '\0'; 495 while ((*p == ' ' || *p == '\t') && p < buf + buflen) 496 p++; 497 if (p >= buf + buflen) 498 continue; 499 user = p; 500 while (*p != '\n' && *p != ' ' && 501 *p != '\t' && p < buf + buflen) { 502 if (!isprint(*p)) 503 goto bail; 504 p++; 505 } 506 } else 507 user = p; 508 *p = '\0'; 509 510 if (p == buf) 511 continue; 512 513 auser = *user ? user : luser; 514 ahost = buf; 515 516 if (strlen(ahost) >= MAXHOSTNAMELEN) 517 continue; 518 519 /* 520 * innetgr() must lookup a hostname (we do not attempt 521 * to change the semantics so that netgroups may have 522 * #.#.#.# addresses in the list.) 523 */ 524 if (ahost[0] == '+') 525 switch (ahost[1]) { 526 case '\0': 527 hostok = 1; 528 break; 529 case '@': 530 if (rhost == (char *)-1) 531 rhost = __gethostloop(raddr, salen); 532 hostok = 0; 533 if (rhost) 534 hostok = innetgr(&ahost[2], rhost, 535 NULL, domain); 536 break; 537 default: 538 hostok = __icheckhost(raddr, salen, &ahost[1]); 539 break; 540 } 541 else if (ahost[0] == '-') 542 switch (ahost[1]) { 543 case '\0': 544 hostok = -1; 545 break; 546 case '@': 547 if (rhost == (char *)-1) 548 rhost = __gethostloop(raddr, salen); 549 hostok = 0; 550 if (rhost) 551 hostok = -innetgr(&ahost[2], rhost, 552 NULL, domain); 553 break; 554 default: 555 hostok = -__icheckhost(raddr, salen, &ahost[1]); 556 break; 557 } 558 else 559 hostok = __icheckhost(raddr, salen, ahost); 560 561 562 if (auser[0] == '+') 563 switch (auser[1]) { 564 case '\0': 565 userok = 1; 566 break; 567 case '@': 568 userok = innetgr(&auser[2], NULL, ruser, 569 domain); 570 break; 571 default: 572 userok = strcmp(ruser, &auser[1]) ? 0 : 1; 573 break; 574 } 575 else if (auser[0] == '-') 576 switch (auser[1]) { 577 case '\0': 578 userok = -1; 579 break; 580 case '@': 581 userok = -innetgr(&auser[2], NULL, ruser, 582 domain); 583 break; 584 default: 585 userok = strcmp(ruser, &auser[1]) ? 0 : -1; 586 break; 587 } 588 else 589 userok = strcmp(ruser, auser) ? 0 : 1; 590 591 /* Check if one component did not match */ 592 if (hostok == 0 || userok == 0) 593 continue; 594 595 /* Check if we got a forbidden pair */ 596 if (userok <= -1 || hostok <= -1) 597 return (-1); 598 599 /* Check if we got a valid pair */ 600 if (hostok >= 1 && userok >= 1) 601 return (0); 602 } 603 bail: 604 return (-1); 605 } 606 607 /* 608 * Returns "true" if match, 0 if no match. If we do not find any 609 * semblance of an A->PTR->A loop, allow a simple #.#.#.# match to work. 610 * 611 * NI_WITHSCOPEID is useful for comparing sin6_scope_id portion 612 * if af == AF_INET6. 613 */ 614 static int 615 __icheckhost(raddr, salen, lhost) 616 struct sockaddr *raddr; 617 socklen_t salen; 618 const char *lhost; 619 { 620 struct addrinfo hints, *res, *r; 621 char h1[NI_MAXHOST], h2[NI_MAXHOST]; 622 int error; 623 #ifdef NI_WITHSCOPEID 624 const int niflags = NI_NUMERICHOST | NI_WITHSCOPEID; 625 #else 626 const int niflags = NI_NUMERICHOST; 627 #endif 628 629 h1[0] = '\0'; 630 if (getnameinfo(raddr, salen, h1, sizeof(h1), NULL, 0, 631 niflags) != 0) 632 return (0); 633 634 /* Resolve laddr into sockaddr */ 635 memset(&hints, 0, sizeof(hints)); 636 hints.ai_family = raddr->sa_family; 637 hints.ai_socktype = SOCK_DGRAM; /*dummy*/ 638 res = NULL; 639 error = getaddrinfo(lhost, "0", &hints, &res); 640 if (error) 641 return (0); 642 643 /* 644 * Try string comparisons between raddr and laddr. 645 */ 646 for (r = res; r; r = r->ai_next) { 647 h2[0] = '\0'; 648 if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2), 649 NULL, 0, niflags) != 0) 650 continue; 651 if (strcmp(h1, h2) == 0) { 652 freeaddrinfo(res); 653 return (1); 654 } 655 } 656 657 /* No match. */ 658 freeaddrinfo(res); 659 return (0); 660 } 661 662 /* 663 * Return the hostname associated with the supplied address. 664 * Do a reverse lookup as well for security. If a loop cannot 665 * be found, pack the result of inet_ntoa() into the string. 666 * 667 * NI_WITHSCOPEID is useful for comparing sin6_scope_id portion 668 * if af == AF_INET6. 669 */ 670 static char * 671 __gethostloop(raddr, salen) 672 struct sockaddr *raddr; 673 socklen_t salen; 674 { 675 static char remotehost[NI_MAXHOST]; 676 char h1[NI_MAXHOST], h2[NI_MAXHOST]; 677 struct addrinfo hints, *res, *r; 678 int error; 679 #ifdef NI_WITHSCOPEID 680 const int niflags = NI_NUMERICHOST | NI_WITHSCOPEID; 681 #else 682 const int niflags = NI_NUMERICHOST; 683 #endif 684 685 h1[0] = remotehost[0] = '\0'; 686 if (getnameinfo(raddr, salen, remotehost, sizeof(remotehost), 687 NULL, 0, NI_NAMEREQD) != 0) 688 return (NULL); 689 if (getnameinfo(raddr, salen, h1, sizeof(h1), NULL, 0, 690 niflags) != 0) 691 return (NULL); 692 693 /* 694 * Look up the name and check that the supplied 695 * address is in the list 696 */ 697 memset(&hints, 0, sizeof(hints)); 698 hints.ai_family = raddr->sa_family; 699 hints.ai_socktype = SOCK_DGRAM; /*dummy*/ 700 hints.ai_flags = AI_CANONNAME; 701 res = NULL; 702 error = getaddrinfo(remotehost, "0", &hints, &res); 703 if (error) 704 return (NULL); 705 706 for (r = res; r; r = r->ai_next) { 707 h2[0] = '\0'; 708 if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2), 709 NULL, 0, niflags) != 0) 710 continue; 711 if (strcmp(h1, h2) == 0) { 712 freeaddrinfo(res); 713 return (remotehost); 714 } 715 } 716 717 /* 718 * either the DNS adminstrator has made a configuration 719 * mistake, or someone has attempted to spoof us 720 */ 721 syslog(LOG_NOTICE, "rcmd: address %s not listed for host %s", 722 h1, res->ai_canonname ? res->ai_canonname : remotehost); 723 freeaddrinfo(res); 724 return (NULL); 725 } 726