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 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by the University of 17 * California, Berkeley and its contributors. 18 * This product includes software developed by Theo de Raadt. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #if defined(LIBC_SCCS) && !defined(lint) 37 static char *rcsid = "$OpenBSD: rcmd.c,v 1.34 2000/01/30 05:17:49 itojun Exp $"; 38 #endif /* LIBC_SCCS and not lint */ 39 40 #include <sys/param.h> 41 #include <sys/socket.h> 42 #include <sys/stat.h> 43 44 #include <netinet/in.h> 45 #include <arpa/inet.h> 46 47 #include <signal.h> 48 #include <fcntl.h> 49 #include <netdb.h> 50 #include <unistd.h> 51 #include <pwd.h> 52 #include <errno.h> 53 #include <stdio.h> 54 #include <ctype.h> 55 #include <string.h> 56 #include <syslog.h> 57 #include <stdlib.h> 58 #include <netgroup.h> 59 60 int __ivaliduser __P((FILE *, in_addr_t, const char *, const char *)); 61 int __ivaliduser_sa __P((FILE *, struct sockaddr *, const char *, const char *)); 62 static int __icheckhost __P((struct sockaddr *, const char *)); 63 static char *__gethostloop __P((struct sockaddr *)); 64 65 int 66 rcmd(ahost, rport, locuser, remuser, cmd, fd2p) 67 char **ahost; 68 in_port_t rport; 69 const char *locuser, *remuser, *cmd; 70 int *fd2p; 71 { 72 return rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, AF_INET); 73 } 74 75 int 76 rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, af) 77 char **ahost; 78 in_port_t rport; 79 const char *locuser, *remuser, *cmd; 80 int *fd2p; 81 int af; 82 { 83 static char hbuf[MAXHOSTNAMELEN]; 84 char pbuf[NI_MAXSERV]; 85 struct addrinfo hints, *res, *r; 86 int error; 87 struct sockaddr_storage from; 88 fd_set *readsp = NULL; 89 int oldmask; 90 pid_t pid; 91 int s, lport, timo; 92 char c, *p; 93 94 /* call rcmdsh() with specified remote shell if appropriate. */ 95 if (!issetugid() && (p = getenv("RSH"))) { 96 struct servent *sp = getservbyname("shell", "tcp"); 97 98 if (sp && sp->s_port == rport) 99 return (rcmdsh(ahost, rport, locuser, remuser, 100 cmd, p)); 101 } 102 103 /* use rsh(1) if non-root and remote port is shell. */ 104 if (geteuid()) { 105 struct servent *sp = getservbyname("shell", "tcp"); 106 107 if (sp && sp->s_port == rport) 108 return (rcmdsh(ahost, rport, locuser, remuser, 109 cmd, NULL)); 110 } 111 112 pid = getpid(); 113 snprintf(pbuf, sizeof(pbuf), "%u", ntohs(rport)); 114 memset(&hints, 0, sizeof(hints)); 115 hints.ai_family = af; 116 hints.ai_socktype = SOCK_STREAM; 117 hints.ai_flags = AI_CANONNAME; 118 error = getaddrinfo(*ahost, pbuf, &hints, &res); 119 if (error) { 120 #if 0 121 warnx("%s: %s", *ahost, gai_strerror(error)); 122 #endif 123 return (-1); 124 } 125 if (res->ai_canonname) { 126 strncpy(hbuf, res->ai_canonname, sizeof(hbuf) - 1); 127 hbuf[sizeof(hbuf) - 1] = '\0'; 128 *ahost = hbuf; 129 } else 130 ; /*XXX*/ 131 132 r = res; 133 oldmask = sigblock(sigmask(SIGURG)); 134 for (timo = 1, lport = IPPORT_RESERVED - 1;;) { 135 s = rresvport_af(&lport, r->ai_family); 136 if (s < 0) { 137 if (errno == EAGAIN) 138 (void)fprintf(stderr, 139 "rcmd: socket: All ports in use\n"); 140 else 141 (void)fprintf(stderr, "rcmd: socket: %s\n", 142 strerror(errno)); 143 if (r->ai_next) { 144 r = r->ai_next; 145 continue; 146 } else { 147 sigsetmask(oldmask); 148 freeaddrinfo(res); 149 return (-1); 150 } 151 } 152 fcntl(s, F_SETOWN, pid); 153 if (connect(s, r->ai_addr, r->ai_addrlen) >= 0) 154 break; 155 (void)close(s); 156 if (errno == EADDRINUSE) { 157 lport--; 158 continue; 159 } 160 if (errno == ECONNREFUSED && timo <= 16) { 161 (void)sleep(timo); 162 timo *= 2; 163 continue; 164 } 165 if (r->ai_next) { 166 int oerrno = errno; 167 char hbuf[NI_MAXHOST]; 168 #ifdef NI_WITHSCOPEID 169 const int niflags = NI_NUMERICHOST | NI_WITHSCOPEID; 170 #else 171 const int niflags = NI_NUMERICHOST; 172 #endif 173 174 hbuf[0] = '\0'; 175 if (getnameinfo(r->ai_addr, r->ai_addrlen, 176 hbuf, sizeof(hbuf), NULL, 0, niflags) != 0) 177 strcpy(hbuf, "(invalid)"); 178 (void)fprintf(stderr, "connect to address %s: ", hbuf); 179 errno = oerrno; 180 perror(0); 181 r = r->ai_next; 182 hbuf[0] = '\0'; 183 if (getnameinfo(r->ai_addr, r->ai_addrlen, 184 hbuf, sizeof(hbuf), NULL, 0, niflags) != 0) 185 strcpy(hbuf, "(invalid)"); 186 (void)fprintf(stderr, "Trying %s...\n", hbuf); 187 continue; 188 } 189 (void)fprintf(stderr, "%s: %s\n", res->ai_canonname, 190 strerror(errno)); 191 sigsetmask(oldmask); 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 int 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 sigsetmask(oldmask); 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 sigsetmask(oldmask); 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 #ifdef lint 389 rlen = rlen; 390 #endif 391 first = 1; 392 hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r"); 393 again: 394 if (hostf) { 395 if (__ivaliduser_sa(hostf, sa, luser, ruser) == 0) { 396 (void)fclose(hostf); 397 return (0); 398 } 399 (void)fclose(hostf); 400 } 401 if (first == 1 && (__check_rhosts_file || superuser)) { 402 first = 0; 403 if ((pwd = getpwnam(luser)) == NULL) 404 return (-1); 405 (void)strcpy(pbuf, pwd->pw_dir); 406 (void)strcat(pbuf, "/.rhosts"); 407 408 /* 409 * Change effective uid while opening .rhosts. If root and 410 * reading an NFS mounted file system, can't read files that 411 * are protected read/write owner only. 412 */ 413 uid = geteuid(); 414 (void)seteuid(pwd->pw_uid); 415 hostf = fopen(pbuf, "r"); 416 (void)seteuid(uid); 417 418 if (hostf == NULL) 419 return (-1); 420 /* 421 * If not a regular file, or is owned by someone other than 422 * user or root or if writeable by anyone but the owner, quit. 423 */ 424 cp = NULL; 425 if (lstat(pbuf, &sbuf) < 0) 426 cp = ".rhosts lstat failed"; 427 else if (!S_ISREG(sbuf.st_mode)) 428 cp = ".rhosts not regular file"; 429 else if (fstat(fileno(hostf), &sbuf) < 0) 430 cp = ".rhosts fstat failed"; 431 else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid) 432 cp = "bad .rhosts owner"; 433 else if (sbuf.st_mode & (S_IWGRP|S_IWOTH)) 434 cp = ".rhosts writeable by other than owner"; 435 /* If there were any problems, quit. */ 436 if (cp) { 437 __rcmd_errstr = cp; 438 (void)fclose(hostf); 439 return (-1); 440 } 441 goto again; 442 } 443 return (-1); 444 } 445 446 /* 447 * XXX 448 * Don't make static, used by lpd(8). 449 * 450 * Returns 0 if ok, -1 if not ok. 451 */ 452 int 453 __ivaliduser(hostf, raddrl, luser, ruser) 454 FILE *hostf; 455 in_addr_t raddrl; 456 const char *luser, *ruser; 457 { 458 struct sockaddr_in sin; 459 460 memset(&sin, 0, sizeof(sin)); 461 sin.sin_family = AF_INET; 462 sin.sin_len = sizeof(struct sockaddr_in); 463 memcpy(&sin.sin_addr, &raddrl, sizeof(sin.sin_addr)); 464 return __ivaliduser_sa(hostf, (struct sockaddr *)&sin, luser, ruser); 465 } 466 467 int 468 __ivaliduser_sa(hostf, raddr, luser, ruser) 469 FILE *hostf; 470 struct sockaddr *raddr; 471 const char *luser, *ruser; 472 { 473 register char *user, *p; 474 char *buf; 475 const char *auser, *ahost; 476 int hostok, userok; 477 char *rhost = (char *)-1; 478 char domain[MAXHOSTNAMELEN]; 479 size_t buflen; 480 481 getdomainname(domain, sizeof(domain)); 482 483 while ((buf = fgetln(hostf, &buflen))) { 484 p = buf; 485 if (*p == '#') 486 continue; 487 while (*p != '\n' && *p != ' ' && *p != '\t' && p < buf + buflen) { 488 if (!isprint(*p)) 489 goto bail; 490 *p = isupper(*p) ? tolower(*p) : *p; 491 p++; 492 } 493 if (p >= buf + buflen) 494 continue; 495 if (*p == ' ' || *p == '\t') { 496 *p++ = '\0'; 497 while ((*p == ' ' || *p == '\t') && p < buf + buflen) 498 p++; 499 if (p >= buf + buflen) 500 continue; 501 user = p; 502 while (*p != '\n' && *p != ' ' && 503 *p != '\t' && p < buf + buflen) { 504 if (!isprint(*p)) 505 goto bail; 506 p++; 507 } 508 } else 509 user = p; 510 *p = '\0'; 511 512 if (p == buf) 513 continue; 514 515 auser = *user ? user : luser; 516 ahost = buf; 517 518 if (strlen(ahost) >= MAXHOSTNAMELEN) 519 continue; 520 521 /* 522 * innetgr() must lookup a hostname (we do not attempt 523 * to change the semantics so that netgroups may have 524 * #.#.#.# addresses in the list.) 525 */ 526 if (ahost[0] == '+') 527 switch (ahost[1]) { 528 case '\0': 529 hostok = 1; 530 break; 531 case '@': 532 if (rhost == (char *)-1) 533 rhost = __gethostloop(raddr); 534 hostok = 0; 535 if (rhost) 536 hostok = innetgr(&ahost[2], rhost, 537 NULL, domain); 538 break; 539 default: 540 hostok = __icheckhost(raddr, &ahost[1]); 541 break; 542 } 543 else if (ahost[0] == '-') 544 switch (ahost[1]) { 545 case '\0': 546 hostok = -1; 547 break; 548 case '@': 549 if (rhost == (char *)-1) 550 rhost = __gethostloop(raddr); 551 hostok = 0; 552 if (rhost) 553 hostok = -innetgr(&ahost[2], rhost, 554 NULL, domain); 555 break; 556 default: 557 hostok = -__icheckhost(raddr, &ahost[1]); 558 break; 559 } 560 else 561 hostok = __icheckhost(raddr, ahost); 562 563 564 if (auser[0] == '+') 565 switch (auser[1]) { 566 case '\0': 567 userok = 1; 568 break; 569 case '@': 570 userok = innetgr(&auser[2], NULL, ruser, 571 domain); 572 break; 573 default: 574 userok = strcmp(ruser, &auser[1]) ? 0 : 1; 575 break; 576 } 577 else if (auser[0] == '-') 578 switch (auser[1]) { 579 case '\0': 580 userok = -1; 581 break; 582 case '@': 583 userok = -innetgr(&auser[2], NULL, ruser, 584 domain); 585 break; 586 default: 587 userok = strcmp(ruser, &auser[1]) ? 0 : -1; 588 break; 589 } 590 else 591 userok = strcmp(ruser, auser) ? 0 : 1; 592 593 /* Check if one component did not match */ 594 if (hostok == 0 || userok == 0) 595 continue; 596 597 /* Check if we got a forbidden pair */ 598 if (userok <= -1 || hostok <= -1) 599 return (-1); 600 601 /* Check if we got a valid pair */ 602 if (hostok >= 1 && userok >= 1) 603 return (0); 604 } 605 bail: 606 return (-1); 607 } 608 609 /* 610 * Returns "true" if match, 0 if no match. If we do not find any 611 * semblance of an A->PTR->A loop, allow a simple #.#.#.# match to work. 612 * 613 * NI_WITHSCOPEID is useful for comparing sin6_scope_id portion 614 * if af == AF_INET6. 615 */ 616 static int 617 __icheckhost(raddr, lhost) 618 struct sockaddr *raddr; 619 const char *lhost; 620 { 621 struct addrinfo hints, *res, *r; 622 char h1[NI_MAXHOST], h2[NI_MAXHOST]; 623 int error; 624 #ifdef NI_WITHSCOPEID 625 const int niflags = NI_NUMERICHOST | NI_WITHSCOPEID; 626 #else 627 const int niflags = NI_NUMERICHOST; 628 #endif 629 630 h1[0] = '\0'; 631 if (getnameinfo(raddr, raddr->sa_len, h1, sizeof(h1), NULL, 0, 632 niflags) != 0) 633 return (0); 634 635 /* Resolve laddr into sockaddr */ 636 memset(&hints, 0, sizeof(hints)); 637 hints.ai_family = raddr->sa_family; 638 hints.ai_socktype = SOCK_DGRAM; /*dummy*/ 639 res = NULL; 640 error = getaddrinfo(lhost, "0", &hints, &res); 641 if (error) 642 return (0); 643 644 /* 645 * Try string comparisons between raddr and laddr. 646 */ 647 for (r = res; r; r = r->ai_next) { 648 h2[0] = '\0'; 649 if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2), 650 NULL, 0, niflags) != 0) 651 continue; 652 if (strcmp(h1, h2) == 0) { 653 freeaddrinfo(res); 654 return (1); 655 } 656 } 657 658 /* No match. */ 659 freeaddrinfo(res); 660 return (0); 661 } 662 663 /* 664 * Return the hostname associated with the supplied address. 665 * Do a reverse lookup as well for security. If a loop cannot 666 * be found, pack the result of inet_ntoa() into the string. 667 * 668 * NI_WITHSCOPEID is useful for comparing sin6_scope_id portion 669 * if af == AF_INET6. 670 */ 671 static char * 672 __gethostloop(raddr) 673 struct sockaddr *raddr; 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, raddr->sa_len, remotehost, sizeof(remotehost), 687 NULL, 0, NI_NAMEREQD) != 0) 688 return (NULL); 689 if (getnameinfo(raddr, raddr->sa_len, 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