rshd.c revision 56758
1/*- 2 * Copyright (c) 1988, 1989, 1992, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34#ifndef lint 35static const char copyright[] = 36"@(#) Copyright (c) 1988, 1989, 1992, 1993, 1994\n\ 37 The Regents of the University of California. All rights reserved.\n"; 38#endif /* not lint */ 39 40#ifndef lint 41#if 0 42static const char sccsid[] = "@(#)rshd.c 8.2 (Berkeley) 4/6/94"; 43#endif 44static const char rcsid[] = 45 "$FreeBSD: head/libexec/rshd/rshd.c 56758 2000-01-28 20:02:02Z shin $"; 46#endif /* not lint */ 47 48/* 49 * remote shell server: 50 * [port]\0 51 * remuser\0 52 * locuser\0 53 * command\0 54 * data 55 */ 56#include <sys/param.h> 57#include <sys/ioctl.h> 58#include <sys/time.h> 59#include <sys/socket.h> 60 61#include <netinet/in_systm.h> 62#include <netinet/in.h> 63#include <netinet/ip.h> 64#include <netinet/tcp.h> 65#include <arpa/inet.h> 66#include <netdb.h> 67 68#include <errno.h> 69#include <fcntl.h> 70#include <libutil.h> 71#include <paths.h> 72#include <pwd.h> 73#include <signal.h> 74#include <stdio.h> 75#include <stdlib.h> 76#include <string.h> 77#include <syslog.h> 78#include <unistd.h> 79#ifdef LOGIN_CAP 80#include <login_cap.h> 81#endif 82 83/* wrapper for KAME-special getnameinfo() */ 84#ifndef NI_WITHSCOPEID 85#define NI_WITHSCOPEID 0 86#endif 87 88int keepalive = 1; 89int log_success; /* If TRUE, log all successful accesses */ 90int sent_null; 91int no_delay; 92#ifdef CRYPT 93int doencrypt = 0; 94#endif 95 96union sockunion { 97 struct sockinet { 98 u_char si_len; 99 u_char si_family; 100 u_short si_port; 101 } su_si; 102 struct sockaddr_in su_sin; 103 struct sockaddr_in6 su_sin6; 104}; 105#define su_len su_si.si_len 106#define su_family su_si.si_family 107#define su_port su_si.si_port 108 109void doit __P((union sockunion *)); 110void error __P((const char *, ...)); 111void getstr __P((char *, int, char *)); 112int local_domain __P((char *)); 113char *topdomain __P((char *)); 114void usage __P((void)); 115 116#ifndef NO_PAM 117extern int auth_pam __P((char *)); 118#endif 119 120#define OPTIONS "alnDL" 121 122int 123main(argc, argv) 124 int argc; 125 char *argv[]; 126{ 127 extern int __check_rhosts_file; 128 struct linger linger; 129 int ch, on = 1, fromlen; 130 struct sockaddr_storage from; 131 132 openlog("rshd", LOG_PID | LOG_ODELAY, LOG_DAEMON); 133 134 opterr = 0; 135 while ((ch = getopt(argc, argv, OPTIONS)) != -1) 136 switch (ch) { 137 case 'a': 138 /* ignored for compatability */ 139 break; 140 case 'l': 141 __check_rhosts_file = 0; 142 break; 143 case 'n': 144 keepalive = 0; 145 break; 146#ifdef CRYPT 147 case 'x': 148 doencrypt = 1; 149 break; 150#endif 151 case 'D': 152 no_delay = 1; 153 break; 154 case 'L': 155 log_success = 1; 156 break; 157 case '?': 158 default: 159 usage(); 160 break; 161 } 162 163 argc -= optind; 164 argv += optind; 165 166#ifdef CRYPT 167 if (doencrypt) { 168 syslog(LOG_ERR, "-k is required for -x"); 169 exit(2); 170 } 171#endif 172 173 fromlen = sizeof (from); 174 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) { 175 syslog(LOG_ERR, "getpeername: %m"); 176 exit(1); 177 } 178 if (keepalive && 179 setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, (char *)&on, 180 sizeof(on)) < 0) 181 syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m"); 182 linger.l_onoff = 1; 183 linger.l_linger = 60; /* XXX */ 184 if (setsockopt(0, SOL_SOCKET, SO_LINGER, (char *)&linger, 185 sizeof (linger)) < 0) 186 syslog(LOG_WARNING, "setsockopt (SO_LINGER): %m"); 187 if (no_delay && 188 setsockopt(0, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) < 0) 189 syslog(LOG_WARNING, "setsockopt (TCP_NODELAY): %m"); 190 doit((union sockunion *)&from); 191 /* NOTREACHED */ 192 return(0); 193} 194 195char username[20] = "USER="; 196char homedir[64] = "HOME="; 197char shell[64] = "SHELL="; 198char path[100] = "PATH="; 199char *envinit[] = 200 {homedir, shell, path, username, 0}; 201char **environ; 202 203void 204doit(fromp) 205 union sockunion *fromp; 206{ 207 extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */ 208 struct passwd *pwd; 209 u_short port; 210 fd_set ready, readfrom; 211 int cc, nfd, pv[2], pid, s; 212 int one = 1; 213 char *errorstr; 214 char *cp, sig, buf[BUFSIZ]; 215 char cmdbuf[NCARGS+1], locuser[16], remuser[16]; 216 char fromhost[2 * MAXHOSTNAMELEN + 1]; 217 char numericname[INET6_ADDRSTRLEN]; 218 int af = fromp->su_family, err; 219 int retval; 220#ifdef CRYPT 221 int rc; 222 int pv1[2], pv2[2]; 223#endif 224#ifdef LOGIN_CAP 225 login_cap_t *lc; 226#endif 227 228 (void) signal(SIGINT, SIG_DFL); 229 (void) signal(SIGQUIT, SIG_DFL); 230 (void) signal(SIGTERM, SIG_DFL); 231#ifdef DEBUG 232 { int t = open(_PATH_TTY, 2); 233 if (t >= 0) { 234 ioctl(t, TIOCNOTTY, (char *)0); 235 (void) close(t); 236 } 237 } 238#endif 239 fromp->su_port = ntohs((u_short)fromp->su_port); 240 if (af != AF_INET 241#ifdef INET6 242 && af != AF_INET6 243#endif 244 ) { 245 syslog(LOG_ERR, "malformed \"from\" address (af %d)\n", af); 246 exit(1); 247 } 248 err = getnameinfo((struct sockaddr *)fromp, fromp->su_len, numericname, 249 sizeof(numericname), NULL, 0, 250 NI_NUMERICHOST|NI_WITHSCOPEID); 251 /* XXX: do 'err' check */ 252#ifdef IP_OPTIONS 253 if (af == AF_INET) { 254 u_char optbuf[BUFSIZ/3]; 255 int optsize = sizeof(optbuf), ipproto, i; 256 struct protoent *ip; 257 258 if ((ip = getprotobyname("ip")) != NULL) 259 ipproto = ip->p_proto; 260 else 261 ipproto = IPPROTO_IP; 262 if (!getsockopt(0, ipproto, IP_OPTIONS, (char *)optbuf, &optsize) && 263 optsize != 0) { 264 for (i = 0; i < optsize; ) { 265 u_char c = optbuf[i]; 266 if (c == IPOPT_LSRR || c == IPOPT_SSRR) { 267 syslog(LOG_NOTICE, 268 "connection refused from %s with IP option %s", 269 numericname, 270 c == IPOPT_LSRR ? "LSRR" : "SSRR"); 271 exit(1); 272 } 273 if (c == IPOPT_EOL) 274 break; 275 i += (c == IPOPT_NOP) ? 1 : optbuf[i+1]; 276 } 277 } 278 } 279#endif 280 281 if (fromp->su_port >= IPPORT_RESERVED || 282 fromp->su_port < IPPORT_RESERVED/2) { 283 syslog(LOG_NOTICE|LOG_AUTH, 284 "connection from %s on illegal port %u", 285 numericname, 286 fromp->su_port); 287 exit(1); 288 } 289 290 (void) alarm(60); 291 port = 0; 292 s = 0; /* not set or used if port == 0 */ 293 for (;;) { 294 char c; 295 if ((cc = read(STDIN_FILENO, &c, 1)) != 1) { 296 if (cc < 0) 297 syslog(LOG_NOTICE, "read: %m"); 298 shutdown(0, 1+1); 299 exit(1); 300 } 301 if (c == 0) 302 break; 303 port = port * 10 + c - '0'; 304 } 305 306 (void) alarm(0); 307 if (port != 0) { 308 int lport = IPPORT_RESERVED - 1; 309 s = rresvport_af(&lport, af); 310 if (s < 0) { 311 syslog(LOG_ERR, "can't get stderr port: %m"); 312 exit(1); 313 } 314 if (port >= IPPORT_RESERVED || 315 port < IPPORT_RESERVED/2) { 316 syslog(LOG_NOTICE|LOG_AUTH, 317 "2nd socket from %s on unreserved port %u", 318 numericname, 319 port); 320 exit(1); 321 } 322 fromp->su_port = htons(port); 323 if (connect(s, (struct sockaddr *)fromp, fromp->su_len) < 0) { 324 syslog(LOG_INFO, "connect second port %d: %m", port); 325 exit(1); 326 } 327 } 328 329 errorstr = NULL; 330 realhostname_sa(fromhost, sizeof(fromhost) - 1, 331 (struct sockaddr *)fromp, 332 fromp->su_len); 333 fromhost[sizeof(fromhost) - 1] = '\0'; 334 335#ifdef CRYPT 336 if (doencrypt && af == AF_INET) { 337 struct sockaddr_in local_addr; 338 rc = sizeof(local_addr); 339 if (getsockname(0, (struct sockaddr *)&local_addr, 340 &rc) < 0) { 341 syslog(LOG_ERR, "getsockname: %m"); 342 error("rlogind: getsockname: %m"); 343 exit(1); 344 } 345 authopts = KOPT_DO_MUTUAL; 346 rc = krb_recvauth(authopts, 0, ticket, 347 "rcmd", instance, &fromaddr, 348 &local_addr, kdata, "", schedule, 349 version); 350 des_set_key(&kdata->session, schedule); 351 } 352#endif 353 getstr(remuser, sizeof(remuser), "remuser"); 354 355 getstr(locuser, sizeof(locuser), "locuser"); 356 getstr(cmdbuf, sizeof(cmdbuf), "command"); 357 setpwent(); 358 pwd = getpwnam(locuser); 359 if (pwd == NULL) { 360 syslog(LOG_INFO|LOG_AUTH, 361 "%s@%s as %s: unknown login. cmd='%.80s'", 362 remuser, fromhost, locuser, cmdbuf); 363 if (errorstr == NULL) 364 errorstr = "Login incorrect.\n"; 365 goto fail; 366 } 367#ifdef LOGIN_CAP 368 lc = login_getpwclass(pwd); 369#endif 370 if (chdir(pwd->pw_dir) < 0) { 371#ifdef LOGIN_CAP 372 if (chdir("/") < 0 || 373 login_getcapbool(lc, "requirehome", !!pwd->pw_uid)) { 374 syslog(LOG_INFO|LOG_AUTH, 375 "%s@%s as %s: no home directory. cmd='%.80s'", 376 remuser, fromhost, locuser, cmdbuf); 377 error("No remote home directory.\n"); 378 exit(0); 379 } 380#else 381 (void) chdir("/"); 382#ifdef notdef 383 syslog(LOG_INFO|LOG_AUTH, 384 "%s@%s as %s: no home directory. cmd='%.80s'", 385 remuser, fromhost, locuser, cmdbuf); 386 error("No remote directory.\n"); 387 exit(1); 388#endif 389#endif 390 pwd->pw_dir = "/"; 391 } 392 393#ifndef NO_PAM 394 retval = auth_pam(locuser); 395 396 if (retval) { 397 if (retval == -1) { 398 syslog(LOG_ERR,"PAM authentication failed"); 399 } 400 else { 401 syslog(LOG_ERR, 402 "User %s failed PAM authentication", locuser); 403 exit(1); 404 } 405 } 406#endif 407 408 if (errorstr || 409 (pwd->pw_expire && time(NULL) >= pwd->pw_expire) || 410 (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' && 411 iruserok_af( 412#ifdef INET6 413 (af == AF_INET6) 414 ? (void *)&fromp->su_sin6.sin6_addr : 415#endif 416 (void *)&fromp->su_sin.sin_addr, 417 pwd->pw_uid == 0, 418 remuser, locuser, af) < 0)) { 419 if (__rcmd_errstr) 420 syslog(LOG_INFO|LOG_AUTH, 421 "%s@%s as %s: permission denied (%s). cmd='%.80s'", 422 remuser, fromhost, locuser, __rcmd_errstr, 423 cmdbuf); 424 else 425 syslog(LOG_INFO|LOG_AUTH, 426 "%s@%s as %s: permission denied. cmd='%.80s'", 427 remuser, fromhost, locuser, cmdbuf); 428fail: 429 if (errorstr == NULL) 430 errorstr = "Login incorrect.\n"; 431 error(errorstr, fromhost); 432 exit(1); 433 } 434 435 if (pwd->pw_uid && !access(_PATH_NOLOGIN, F_OK)) { 436 error("Logins currently disabled.\n"); 437 exit(1); 438 } 439#ifdef LOGIN_CAP 440 if (lc != NULL && fromp->su_family == AF_INET) { /*XXX*/ 441 char remote_ip[MAXHOSTNAMELEN]; 442 443 strncpy(remote_ip, numericname, 444 sizeof(remote_ip) - 1); 445 remote_ip[sizeof(remote_ip) - 1] = 0; 446 if (!auth_hostok(lc, fromhost, remote_ip)) { 447 syslog(LOG_INFO|LOG_AUTH, 448 "%s@%s as %s: permission denied (%s). cmd='%.80s'", 449 remuser, fromhost, locuser, __rcmd_errstr, 450 cmdbuf); 451 error("Login incorrect.\n"); 452 exit(1); 453 } 454 if (!auth_timeok(lc, time(NULL))) { 455 error("Logins not available right now\n"); 456 exit(1); 457 } 458 } 459#endif /* !LOGIN_CAP */ 460#if BSD > 43 461 /* before fork, while we're session leader */ 462 if (setlogin(pwd->pw_name) < 0) 463 syslog(LOG_ERR, "setlogin() failed: %m"); 464#endif 465 466 (void) write(STDERR_FILENO, "\0", 1); 467 sent_null = 1; 468 469 if (port) { 470 if (pipe(pv) < 0) { 471 error("Can't make pipe.\n"); 472 exit(1); 473 } 474#ifdef CRYPT 475 if (doencrypt) { 476 if (pipe(pv1) < 0) { 477 error("Can't make 2nd pipe.\n"); 478 exit(1); 479 } 480 if (pipe(pv2) < 0) { 481 error("Can't make 3rd pipe.\n"); 482 exit(1); 483 } 484 } 485#endif 486 pid = fork(); 487 if (pid == -1) { 488 error("Can't fork; try again.\n"); 489 exit(1); 490 } 491 if (pid) { 492#ifdef CRYPT 493 if (doencrypt) { 494 static char msg[] = SECURE_MESSAGE; 495 (void) close(pv1[1]); 496 (void) close(pv2[1]); 497 des_enc_write(s, msg, sizeof(msg) - 1, 498 schedule, &kdata->session); 499 500 } else 501#endif 502 { 503 (void) close(0); 504 (void) close(1); 505 } 506 (void) close(2); 507 (void) close(pv[1]); 508 509 FD_ZERO(&readfrom); 510 FD_SET(s, &readfrom); 511 FD_SET(pv[0], &readfrom); 512 if (pv[0] > s) 513 nfd = pv[0]; 514 else 515 nfd = s; 516#ifdef CRYPT 517 if (doencrypt) { 518 FD_ZERO(&writeto); 519 FD_SET(pv2[0], &writeto); 520 FD_SET(pv1[0], &readfrom); 521 522 nfd = MAX(nfd, pv2[0]); 523 nfd = MAX(nfd, pv1[0]); 524 } else 525#endif 526 ioctl(pv[0], FIONBIO, (char *)&one); 527 528 /* should set s nbio! */ 529 nfd++; 530 do { 531 ready = readfrom; 532#ifdef CRYPT 533 if (doencrypt) { 534 wready = writeto; 535 if (select(nfd, &ready, 536 &wready, (fd_set *) 0, 537 (struct timeval *) 0) < 0) 538 break; 539 } else 540#endif 541 if (select(nfd, &ready, (fd_set *)0, 542 (fd_set *)0, (struct timeval *)0) < 0) 543 break; 544 if (FD_ISSET(s, &ready)) { 545 int ret; 546#ifdef CRYPT 547 if (doencrypt) 548 ret = des_enc_read(s, &sig, 1, 549 schedule, &kdata->session); 550 else 551#endif 552 ret = read(s, &sig, 1); 553 if (ret <= 0) 554 FD_CLR(s, &readfrom); 555 else 556 killpg(pid, sig); 557 } 558 if (FD_ISSET(pv[0], &ready)) { 559 errno = 0; 560 cc = read(pv[0], buf, sizeof(buf)); 561 if (cc <= 0) { 562 shutdown(s, 1+1); 563 FD_CLR(pv[0], &readfrom); 564 } else { 565#ifdef CRYPT 566 if (doencrypt) 567 (void) 568 des_enc_write(s, buf, cc, 569 schedule, &kdata->session); 570 else 571#endif 572 (void) 573 write(s, buf, cc); 574 } 575 } 576#ifdef CRYPT 577 if (doencrypt && FD_ISSET(pv1[0], &ready)) { 578 errno = 0; 579 cc = read(pv1[0], buf, sizeof(buf)); 580 if (cc <= 0) { 581 shutdown(pv1[0], 1+1); 582 FD_CLR(pv1[0], &readfrom); 583 } else 584 (void) des_enc_write(STDOUT_FILENO, 585 buf, cc, 586 schedule, &kdata->session); 587 } 588 589 if (doencrypt && FD_ISSET(pv2[0], &wready)) { 590 errno = 0; 591 cc = des_enc_read(STDIN_FILENO, 592 buf, sizeof(buf), 593 schedule, &kdata->session); 594 if (cc <= 0) { 595 shutdown(pv2[0], 1+1); 596 FD_CLR(pv2[0], &writeto); 597 } else 598 (void) write(pv2[0], buf, cc); 599 } 600#endif 601 602 } while (FD_ISSET(s, &readfrom) || 603#ifdef CRYPT 604 (doencrypt && FD_ISSET(pv1[0], &readfrom)) || 605#endif 606 FD_ISSET(pv[0], &readfrom)); 607 exit(0); 608 } 609 setpgrp(0, getpid()); 610 (void) close(s); 611 (void) close(pv[0]); 612#ifdef CRYPT 613 if (doencrypt) { 614 close(pv1[0]); close(pv2[0]); 615 dup2(pv1[1], 1); 616 dup2(pv2[1], 0); 617 close(pv1[1]); 618 close(pv2[1]); 619 } 620#endif 621 dup2(pv[1], 2); 622 close(pv[1]); 623 } 624 if (*pwd->pw_shell == '\0') 625 pwd->pw_shell = _PATH_BSHELL; 626 environ = envinit; 627 strncat(homedir, pwd->pw_dir, sizeof(homedir)-6); 628 strcat(path, _PATH_DEFPATH); 629 strncat(shell, pwd->pw_shell, sizeof(shell)-7); 630 strncat(username, pwd->pw_name, sizeof(username)-6); 631 cp = strrchr(pwd->pw_shell, '/'); 632 if (cp) 633 cp++; 634 else 635 cp = pwd->pw_shell; 636#ifdef LOGIN_CAP 637 if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETALL) != 0) { 638 syslog(LOG_ERR, "setusercontext: %m"); 639 exit(1); 640 } 641 login_close(lc); 642#else 643 (void) setgid((gid_t)pwd->pw_gid); 644 initgroups(pwd->pw_name, pwd->pw_gid); 645 (void) setuid((uid_t)pwd->pw_uid); 646#endif 647 endpwent(); 648 if (log_success || pwd->pw_uid == 0) { 649 syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'", 650 remuser, fromhost, locuser, cmdbuf); 651 } 652 execl(pwd->pw_shell, cp, "-c", cmdbuf, 0); 653 perror(pwd->pw_shell); 654 exit(1); 655} 656 657/* 658 * Report error to client. Note: can't be used until second socket has 659 * connected to client, or older clients will hang waiting for that 660 * connection first. 661 */ 662#if __STDC__ 663#include <stdarg.h> 664#else 665#include <varargs.h> 666#endif 667 668void 669#if __STDC__ 670error(const char *fmt, ...) 671#else 672error(fmt, va_alist) 673 char *fmt; 674 va_dcl 675#endif 676{ 677 va_list ap; 678 int len; 679 char *bp, buf[BUFSIZ]; 680#if __STDC__ 681 va_start(ap, fmt); 682#else 683 va_start(ap); 684#endif 685 bp = buf; 686 if (sent_null == 0) { 687 *bp++ = 1; 688 len = 1; 689 } else 690 len = 0; 691 (void)vsnprintf(bp, sizeof(buf) - 1, fmt, ap); 692 (void)write(STDERR_FILENO, buf, len + strlen(bp)); 693} 694 695void 696getstr(buf, cnt, err) 697 char *buf, *err; 698 int cnt; 699{ 700 char c; 701 702 do { 703 if (read(STDIN_FILENO, &c, 1) != 1) 704 exit(1); 705 *buf++ = c; 706 if (--cnt == 0) { 707 error("%s too long\n", err); 708 exit(1); 709 } 710 } while (c != 0); 711} 712 713/* 714 * Check whether host h is in our local domain, 715 * defined as sharing the last two components of the domain part, 716 * or the entire domain part if the local domain has only one component. 717 * If either name is unqualified (contains no '.'), 718 * assume that the host is local, as it will be 719 * interpreted as such. 720 */ 721int 722local_domain(h) 723 char *h; 724{ 725 char localhost[MAXHOSTNAMELEN]; 726 char *p1, *p2; 727 728 localhost[0] = 0; 729 (void) gethostname(localhost, sizeof(localhost) - 1); 730 localhost[sizeof(localhost) - 1] = '\0'; 731 p1 = topdomain(localhost); 732 p2 = topdomain(h); 733 if (p1 == NULL || p2 == NULL || !strcasecmp(p1, p2)) 734 return (1); 735 return (0); 736} 737 738char * 739topdomain(h) 740 char *h; 741{ 742 char *p, *maybe = NULL; 743 int dots = 0; 744 745 for (p = h + strlen(h); p >= h; p--) { 746 if (*p == '.') { 747 if (++dots == 2) 748 return (p); 749 maybe = p; 750 } 751 } 752 return (maybe); 753} 754 755void 756usage() 757{ 758 759 syslog(LOG_ERR, "usage: rshd [-%s]", OPTIONS); 760 exit(2); 761} 762