rshd.c revision 19108
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 * $Id: rshd.c,v 1.8 1996/09/22 21:55:08 wosch Exp $ 34 */ 35 36#ifndef lint 37static char copyright[] = 38"@(#) Copyright (c) 1988, 1989, 1992, 1993, 1994\n\ 39 The Regents of the University of California. All rights reserved.\n"; 40#endif /* not lint */ 41 42#ifndef lint 43static char sccsid[] = "@(#)rshd.c 8.2 (Berkeley) 4/6/94"; 44#endif /* not lint */ 45 46/* 47 * remote shell server: 48 * [port]\0 49 * remuser\0 50 * locuser\0 51 * command\0 52 * data 53 */ 54#include <sys/param.h> 55#include <sys/ioctl.h> 56#include <sys/time.h> 57#include <sys/socket.h> 58 59#include <netinet/in.h> 60#include <arpa/inet.h> 61#include <netdb.h> 62 63#include <errno.h> 64#include <fcntl.h> 65#include <paths.h> 66#include <pwd.h> 67#include <signal.h> 68#include <stdio.h> 69#include <stdlib.h> 70#include <string.h> 71#include <syslog.h> 72#include <unistd.h> 73 74int keepalive = 1; 75int check_all; 76int log_success; /* If TRUE, log all successful accesses */ 77int sent_null; 78 79void doit __P((struct sockaddr_in *)); 80void error __P((const char *, ...)); 81void getstr __P((char *, int, char *)); 82int local_domain __P((char *)); 83char *topdomain __P((char *)); 84void usage __P((void)); 85 86#ifdef KERBEROS 87#include <des.h> 88#include <kerberosIV/krb.h> 89#define VERSION_SIZE 9 90#define SECURE_MESSAGE "This rsh session is using DES encryption for all transmissions.\r\n" 91#define OPTIONS "alnkvxL" 92char authbuf[sizeof(AUTH_DAT)]; 93char tickbuf[sizeof(KTEXT_ST)]; 94int doencrypt, use_kerberos, vacuous; 95Key_schedule schedule; 96#else 97#define OPTIONS "alnL" 98#endif 99 100int 101main(argc, argv) 102 int argc; 103 char *argv[]; 104{ 105 extern int __check_rhosts_file; 106 struct linger linger; 107 int ch, on = 1, fromlen; 108 struct sockaddr_in from; 109 110 openlog("rshd", LOG_PID | LOG_ODELAY, LOG_DAEMON); 111 112 opterr = 0; 113 while ((ch = getopt(argc, argv, OPTIONS)) != EOF) 114 switch (ch) { 115 case 'a': 116 check_all = 1; 117 break; 118 case 'l': 119 __check_rhosts_file = 0; 120 break; 121 case 'n': 122 keepalive = 0; 123 break; 124#ifdef KERBEROS 125 case 'k': 126 use_kerberos = 1; 127 break; 128 129 case 'v': 130 vacuous = 1; 131 break; 132 133#ifdef CRYPT 134 case 'x': 135 doencrypt = 1; 136 break; 137#endif 138#endif 139 case 'L': 140 log_success = 1; 141 break; 142 case '?': 143 default: 144 usage(); 145 break; 146 } 147 148 argc -= optind; 149 argv += optind; 150 151#ifdef KERBEROS 152 if (use_kerberos && vacuous) { 153 syslog(LOG_ERR, "only one of -k and -v allowed"); 154 exit(2); 155 } 156#ifdef CRYPT 157 if (doencrypt && !use_kerberos) { 158 syslog(LOG_ERR, "-k is required for -x"); 159 exit(2); 160 } 161#endif 162#endif 163 164 fromlen = sizeof (from); 165 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) { 166 syslog(LOG_ERR, "getpeername: %m"); 167 _exit(1); 168 } 169 if (keepalive && 170 setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, (char *)&on, 171 sizeof(on)) < 0) 172 syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m"); 173 linger.l_onoff = 1; 174 linger.l_linger = 60; /* XXX */ 175 if (setsockopt(0, SOL_SOCKET, SO_LINGER, (char *)&linger, 176 sizeof (linger)) < 0) 177 syslog(LOG_WARNING, "setsockopt (SO_LINGER): %m"); 178 doit(&from); 179 /* NOTREACHED */ 180} 181 182char username[20] = "USER="; 183char homedir[64] = "HOME="; 184char shell[64] = "SHELL="; 185char path[100] = "PATH="; 186char *envinit[] = 187 {homedir, shell, path, username, 0}; 188char **environ; 189 190void 191doit(fromp) 192 struct sockaddr_in *fromp; 193{ 194 extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */ 195 struct hostent *hp; 196 struct passwd *pwd; 197 u_short port; 198 fd_set ready, readfrom; 199 int cc, nfd, pv[2], pid, s; 200 int one = 1; 201 char *hostname, *errorstr, *errorhost; 202 char *cp, sig, buf[BUFSIZ]; 203 char cmdbuf[NCARGS+1], locuser[16], remuser[16]; 204 char remotehost[2 * MAXHOSTNAMELEN + 1]; 205 206#ifdef KERBEROS 207 AUTH_DAT *kdata = (AUTH_DAT *) NULL; 208 KTEXT ticket = (KTEXT) NULL; 209 char instance[INST_SZ], version[VERSION_SIZE]; 210 struct sockaddr_in fromaddr; 211 int rc; 212 long authopts; 213 int pv1[2], pv2[2]; 214 fd_set wready, writeto; 215 216 fromaddr = *fromp; 217#endif 218 219 (void) signal(SIGINT, SIG_DFL); 220 (void) signal(SIGQUIT, SIG_DFL); 221 (void) signal(SIGTERM, SIG_DFL); 222#ifdef DEBUG 223 { int t = open(_PATH_TTY, 2); 224 if (t >= 0) { 225 ioctl(t, TIOCNOTTY, (char *)0); 226 (void) close(t); 227 } 228 } 229#endif 230 fromp->sin_port = ntohs((u_short)fromp->sin_port); 231 if (fromp->sin_family != AF_INET) { 232 syslog(LOG_ERR, "malformed \"from\" address (af %d)\n", 233 fromp->sin_family); 234 exit(1); 235 } 236#ifdef IP_OPTIONS 237 { 238 u_char optbuf[BUFSIZ/3], *cp; 239 char lbuf[BUFSIZ], *lp; 240 int optsize = sizeof(optbuf), ipproto; 241 struct protoent *ip; 242 243 if ((ip = getprotobyname("ip")) != NULL) 244 ipproto = ip->p_proto; 245 else 246 ipproto = IPPROTO_IP; 247 if (!getsockopt(0, ipproto, IP_OPTIONS, (char *)optbuf, &optsize) && 248 optsize != 0) { 249 lp = lbuf; 250 for (cp = optbuf; optsize > 0; cp++, optsize--, lp += 3) 251 sprintf(lp, " %2.2x", *cp); 252 syslog(LOG_NOTICE, 253 "Connection received from %s using IP options (ignored):%s", 254 inet_ntoa(fromp->sin_addr), lbuf); 255 if (setsockopt(0, ipproto, IP_OPTIONS, 256 (char *)NULL, optsize) != 0) { 257 syslog(LOG_ERR, "setsockopt IP_OPTIONS NULL: %m"); 258 exit(1); 259 } 260 } 261 } 262#endif 263 264#ifdef KERBEROS 265 if (!use_kerberos) 266#endif 267 if (fromp->sin_port >= IPPORT_RESERVED || 268 fromp->sin_port < IPPORT_RESERVED/2) { 269 syslog(LOG_NOTICE|LOG_AUTH, 270 "Connection from %s on illegal port %u", 271 inet_ntoa(fromp->sin_addr), 272 fromp->sin_port); 273 exit(1); 274 } 275 276 (void) alarm(60); 277 port = 0; 278 for (;;) { 279 char c; 280 if ((cc = read(STDIN_FILENO, &c, 1)) != 1) { 281 if (cc < 0) 282 syslog(LOG_NOTICE, "read: %m"); 283 shutdown(0, 1+1); 284 exit(1); 285 } 286 if (c== 0) 287 break; 288 port = port * 10 + c - '0'; 289 } 290 291 (void) alarm(0); 292 if (port != 0) { 293 int lport = IPPORT_RESERVED - 1; 294 s = rresvport(&lport); 295 if (s < 0) { 296 syslog(LOG_ERR, "can't get stderr port: %m"); 297 exit(1); 298 } 299#ifdef KERBEROS 300 if (!use_kerberos) 301#endif 302 if (port >= IPPORT_RESERVED) { 303 syslog(LOG_ERR, "2nd port not reserved\n"); 304 exit(1); 305 } 306 fromp->sin_port = htons(port); 307 if (connect(s, (struct sockaddr *)fromp, sizeof (*fromp)) < 0) { 308 syslog(LOG_INFO, "connect second port %d: %m", port); 309 exit(1); 310 } 311 } 312 313#ifdef KERBEROS 314 if (vacuous) { 315 error("rshd: remote host requires Kerberos authentication\n"); 316 exit(1); 317 } 318#endif 319 320#ifdef notdef 321 /* from inetd, socket is already on 0, 1, 2 */ 322 dup2(f, 0); 323 dup2(f, 1); 324 dup2(f, 2); 325#endif 326 errorstr = NULL; 327 hp = gethostbyaddr((char *)&fromp->sin_addr, sizeof (struct in_addr), 328 fromp->sin_family); 329 if (hp) { 330 /* 331 * If name returned by gethostbyaddr is in our domain, 332 * attempt to verify that we haven't been fooled by someone 333 * in a remote net; look up the name and check that this 334 * address corresponds to the name. 335 */ 336 hostname = hp->h_name; 337#ifdef KERBEROS 338 if (!use_kerberos) 339#endif 340 if (check_all || local_domain(hp->h_name)) { 341 strncpy(remotehost, hp->h_name, sizeof(remotehost) - 1); 342 remotehost[sizeof(remotehost) - 1] = 0; 343 errorhost = remotehost; 344 hp = gethostbyname(remotehost); 345 if (hp == NULL) { 346 syslog(LOG_INFO, 347 "Couldn't look up address for %s", 348 remotehost); 349 errorstr = 350 "Couldn't look up address for your host (%s)\n"; 351 hostname = inet_ntoa(fromp->sin_addr); 352 } else for (; ; hp->h_addr_list++) { 353 if (hp->h_addr_list[0] == NULL) { 354 syslog(LOG_NOTICE, 355 "Host addr %s not listed for host %s", 356 inet_ntoa(fromp->sin_addr), 357 hp->h_name); 358 errorstr = 359 "Host address mismatch for %s\n"; 360 hostname = inet_ntoa(fromp->sin_addr); 361 break; 362 } 363 if (!bcmp(hp->h_addr_list[0], 364 (caddr_t)&fromp->sin_addr, 365 sizeof(fromp->sin_addr))) { 366 hostname = remotehost; 367 break; 368 } 369 } 370 } 371 } else 372 errorhost = hostname = inet_ntoa(fromp->sin_addr); 373 374#ifdef KERBEROS 375 if (use_kerberos) { 376 kdata = (AUTH_DAT *) authbuf; 377 ticket = (KTEXT) tickbuf; 378 authopts = 0L; 379 strcpy(instance, "*"); 380 version[VERSION_SIZE - 1] = '\0'; 381#ifdef CRYPT 382 if (doencrypt) { 383 struct sockaddr_in local_addr; 384 rc = sizeof(local_addr); 385 if (getsockname(0, (struct sockaddr *)&local_addr, 386 &rc) < 0) { 387 syslog(LOG_ERR, "getsockname: %m"); 388 error("rlogind: getsockname: %m"); 389 exit(1); 390 } 391 authopts = KOPT_DO_MUTUAL; 392 rc = krb_recvauth(authopts, 0, ticket, 393 "rcmd", instance, &fromaddr, 394 &local_addr, kdata, "", schedule, 395 version); 396 des_set_key_krb(&kdata->session, schedule); 397 } else 398#endif 399 rc = krb_recvauth(authopts, 0, ticket, "rcmd", 400 instance, &fromaddr, 401 (struct sockaddr_in *) 0, 402 kdata, "", NULL, version); 403 if (rc != KSUCCESS) { 404 error("Kerberos authentication failure: %s\n", 405 krb_err_txt[rc]); 406 exit(1); 407 } 408 } else 409#endif 410 getstr(remuser, sizeof(remuser), "remuser"); 411 412 getstr(locuser, sizeof(locuser), "locuser"); 413 getstr(cmdbuf, sizeof(cmdbuf), "command"); 414 setpwent(); 415 pwd = getpwnam(locuser); 416 if (pwd == NULL) { 417 syslog(LOG_INFO|LOG_AUTH, 418 "%s@%s as %s: unknown login. cmd='%.80s'", 419 remuser, hostname, locuser, cmdbuf); 420 if (errorstr == NULL) 421 errorstr = "Login incorrect.\n"; 422 goto fail; 423 } 424 if (chdir(pwd->pw_dir) < 0) { 425 (void) chdir("/"); 426#ifdef notdef 427 syslog(LOG_INFO|LOG_AUTH, 428 "%s@%s as %s: no home directory. cmd='%.80s'", 429 remuser, hostname, locuser, cmdbuf); 430 error("No remote directory.\n"); 431 exit(1); 432#endif 433 } 434 435#ifdef KERBEROS 436 if (use_kerberos) { 437 if (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0') { 438 if (kuserok(kdata, locuser) != 0) { 439 syslog(LOG_INFO|LOG_AUTH, 440 "Kerberos rsh denied to %s.%s@%s", 441 kdata->pname, kdata->pinst, kdata->prealm); 442 error("Permission denied.\n"); 443 exit(1); 444 } 445 } 446 } else 447#endif 448 449 if (errorstr || 450 (pwd->pw_expire && time(NULL) >= pwd->pw_expire) || 451 (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' && 452 iruserok(fromp->sin_addr.s_addr, pwd->pw_uid == 0, 453 remuser, locuser) < 0)) { 454 if (__rcmd_errstr) 455 syslog(LOG_INFO|LOG_AUTH, 456 "%s@%s as %s: permission denied (%s). cmd='%.80s'", 457 remuser, hostname, locuser, __rcmd_errstr, 458 cmdbuf); 459 else 460 syslog(LOG_INFO|LOG_AUTH, 461 "%s@%s as %s: permission denied. cmd='%.80s'", 462 remuser, hostname, locuser, cmdbuf); 463fail: 464 if (errorstr == NULL) 465 errorstr = "Permission denied.\n"; 466 error(errorstr, errorhost); 467 exit(1); 468 } 469 470 if (pwd->pw_uid && !access(_PATH_NOLOGIN, F_OK)) { 471 error("Logins currently disabled.\n"); 472 exit(1); 473 } 474#if BSD > 43 475 /* before fork, while we're session leader */ 476 if (setlogin(pwd->pw_name) < 0) 477 syslog(LOG_ERR, "setlogin() failed: %m"); 478#endif 479 480 (void) write(STDERR_FILENO, "\0", 1); 481 sent_null = 1; 482 483 if (port) { 484 if (pipe(pv) < 0) { 485 error("Can't make pipe.\n"); 486 exit(1); 487 } 488#ifdef CRYPT 489#ifdef KERBEROS 490 if (doencrypt) { 491 if (pipe(pv1) < 0) { 492 error("Can't make 2nd pipe.\n"); 493 exit(1); 494 } 495 if (pipe(pv2) < 0) { 496 error("Can't make 3rd pipe.\n"); 497 exit(1); 498 } 499 } 500#endif 501#endif 502 pid = fork(); 503 if (pid == -1) { 504 error("Can't fork; try again.\n"); 505 exit(1); 506 } 507 if (pid) { 508#ifdef CRYPT 509#ifdef KERBEROS 510 if (doencrypt) { 511 static char msg[] = SECURE_MESSAGE; 512 (void) close(pv1[1]); 513 (void) close(pv2[1]); 514 des_write(s, msg, sizeof(msg) - 1); 515 516 } else 517#endif 518#endif 519 { 520 (void) close(0); 521 (void) close(1); 522 } 523 (void) close(2); 524 (void) close(pv[1]); 525 526 FD_ZERO(&readfrom); 527 FD_SET(s, &readfrom); 528 FD_SET(pv[0], &readfrom); 529 if (pv[0] > s) 530 nfd = pv[0]; 531 else 532 nfd = s; 533#ifdef CRYPT 534#ifdef KERBEROS 535 if (doencrypt) { 536 FD_ZERO(&writeto); 537 FD_SET(pv2[0], &writeto); 538 FD_SET(pv1[0], &readfrom); 539 540 nfd = MAX(nfd, pv2[0]); 541 nfd = MAX(nfd, pv1[0]); 542 } else 543#endif 544#endif 545 ioctl(pv[0], FIONBIO, (char *)&one); 546 547 /* should set s nbio! */ 548 nfd++; 549 do { 550 ready = readfrom; 551#ifdef CRYPT 552#ifdef KERBEROS 553 if (doencrypt) { 554 wready = writeto; 555 if (select(nfd, &ready, 556 &wready, (fd_set *) 0, 557 (struct timeval *) 0) < 0) 558 break; 559 } else 560#endif 561#endif 562 if (select(nfd, &ready, (fd_set *)0, 563 (fd_set *)0, (struct timeval *)0) < 0) 564 break; 565 if (FD_ISSET(s, &ready)) { 566 int ret; 567#ifdef CRYPT 568#ifdef KERBEROS 569 if (doencrypt) 570 ret = des_read(s, &sig, 1); 571 else 572#endif 573#endif 574 ret = read(s, &sig, 1); 575 if (ret <= 0) 576 FD_CLR(s, &readfrom); 577 else 578 killpg(pid, sig); 579 } 580 if (FD_ISSET(pv[0], &ready)) { 581 errno = 0; 582 cc = read(pv[0], buf, sizeof(buf)); 583 if (cc <= 0) { 584 shutdown(s, 1+1); 585 FD_CLR(pv[0], &readfrom); 586 } else { 587#ifdef CRYPT 588#ifdef KERBEROS 589 if (doencrypt) 590 (void) 591 des_write(s, buf, cc); 592 else 593#endif 594#endif 595 (void) 596 write(s, buf, cc); 597 } 598 } 599#ifdef CRYPT 600#ifdef KERBEROS 601 if (doencrypt && FD_ISSET(pv1[0], &ready)) { 602 errno = 0; 603 cc = read(pv1[0], buf, sizeof(buf)); 604 if (cc <= 0) { 605 shutdown(pv1[0], 1+1); 606 FD_CLR(pv1[0], &readfrom); 607 } else 608 (void) des_write(STDOUT_FILENO, 609 buf, cc); 610 } 611 612 if (doencrypt && FD_ISSET(pv2[0], &wready)) { 613 errno = 0; 614 cc = des_read(STDIN_FILENO, 615 buf, sizeof(buf)); 616 if (cc <= 0) { 617 shutdown(pv2[0], 1+1); 618 FD_CLR(pv2[0], &writeto); 619 } else 620 (void) write(pv2[0], buf, cc); 621 } 622#endif 623#endif 624 625 } while (FD_ISSET(s, &readfrom) || 626#ifdef CRYPT 627#ifdef KERBEROS 628 (doencrypt && FD_ISSET(pv1[0], &readfrom)) || 629#endif 630#endif 631 FD_ISSET(pv[0], &readfrom)); 632 exit(0); 633 } 634 setpgrp(0, getpid()); 635 (void) close(s); 636 (void) close(pv[0]); 637#ifdef CRYPT 638#ifdef KERBEROS 639 if (doencrypt) { 640 close(pv1[0]); close(pv2[0]); 641 dup2(pv1[1], 1); 642 dup2(pv2[1], 0); 643 close(pv1[1]); 644 close(pv2[1]); 645 } 646#endif 647#endif 648 dup2(pv[1], 2); 649 close(pv[1]); 650 } 651 if (*pwd->pw_shell == '\0') 652 pwd->pw_shell = _PATH_BSHELL; 653 (void) setgid((gid_t)pwd->pw_gid); 654 initgroups(pwd->pw_name, pwd->pw_gid); 655 (void) setuid((uid_t)pwd->pw_uid); 656 environ = envinit; 657 strncat(homedir, pwd->pw_dir, sizeof(homedir)-6); 658 strcat(path, _PATH_DEFPATH); 659 strncat(shell, pwd->pw_shell, sizeof(shell)-7); 660 strncat(username, pwd->pw_name, sizeof(username)-6); 661 cp = strrchr(pwd->pw_shell, '/'); 662 if (cp) 663 cp++; 664 else 665 cp = pwd->pw_shell; 666 endpwent(); 667 if (log_success || pwd->pw_uid == 0) { 668#ifdef KERBEROS 669 if (use_kerberos) 670 syslog(LOG_INFO|LOG_AUTH, 671 "Kerberos shell from %s.%s@%s on %s as %s, cmd='%.80s'", 672 kdata->pname, kdata->pinst, kdata->prealm, 673 hostname, locuser, cmdbuf); 674 else 675#endif 676 syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'", 677 remuser, hostname, locuser, cmdbuf); 678 } 679 execl(pwd->pw_shell, cp, "-c", cmdbuf, 0); 680 perror(pwd->pw_shell); 681 exit(1); 682} 683 684/* 685 * Report error to client. Note: can't be used until second socket has 686 * connected to client, or older clients will hang waiting for that 687 * connection first. 688 */ 689#if __STDC__ 690#include <stdarg.h> 691#else 692#include <varargs.h> 693#endif 694 695void 696#if __STDC__ 697error(const char *fmt, ...) 698#else 699error(fmt, va_alist) 700 char *fmt; 701 va_dcl 702#endif 703{ 704 va_list ap; 705 int len; 706 char *bp, buf[BUFSIZ]; 707#if __STDC__ 708 va_start(ap, fmt); 709#else 710 va_start(ap); 711#endif 712 bp = buf; 713 if (sent_null == 0) { 714 *bp++ = 1; 715 len = 1; 716 } else 717 len = 0; 718 (void)vsnprintf(bp, sizeof(buf) - 1, fmt, ap); 719 (void)write(STDERR_FILENO, buf, len + strlen(bp)); 720} 721 722void 723getstr(buf, cnt, err) 724 char *buf, *err; 725 int cnt; 726{ 727 char c; 728 729 do { 730 if (read(STDIN_FILENO, &c, 1) != 1) 731 exit(1); 732 *buf++ = c; 733 if (--cnt == 0) { 734 error("%s too long\n", err); 735 exit(1); 736 } 737 } while (c != 0); 738} 739 740/* 741 * Check whether host h is in our local domain, 742 * defined as sharing the last two components of the domain part, 743 * or the entire domain part if the local domain has only one component. 744 * If either name is unqualified (contains no '.'), 745 * assume that the host is local, as it will be 746 * interpreted as such. 747 */ 748int 749local_domain(h) 750 char *h; 751{ 752 char localhost[MAXHOSTNAMELEN]; 753 char *p1, *p2; 754 755 localhost[0] = 0; 756 (void) gethostname(localhost, sizeof(localhost)); 757 p1 = topdomain(localhost); 758 p2 = topdomain(h); 759 if (p1 == NULL || p2 == NULL || !strcasecmp(p1, p2)) 760 return (1); 761 return (0); 762} 763 764char * 765topdomain(h) 766 char *h; 767{ 768 char *p, *maybe = NULL; 769 int dots = 0; 770 771 for (p = h + strlen(h); p >= h; p--) { 772 if (*p == '.') { 773 if (++dots == 2) 774 return (p); 775 maybe = p; 776 } 777 } 778 return (maybe); 779} 780 781void 782usage() 783{ 784 785 syslog(LOG_ERR, "usage: rshd [-%s]", OPTIONS); 786 exit(2); 787} 788