rshd.c revision 24379
11592Srgrimes/*- 21592Srgrimes * Copyright (c) 1988, 1989, 1992, 1993, 1994 31592Srgrimes * The Regents of the University of California. All rights reserved. 41592Srgrimes * 51592Srgrimes * Redistribution and use in source and binary forms, with or without 61592Srgrimes * modification, are permitted provided that the following conditions 71592Srgrimes * are met: 81592Srgrimes * 1. Redistributions of source code must retain the above copyright 91592Srgrimes * notice, this list of conditions and the following disclaimer. 101592Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111592Srgrimes * notice, this list of conditions and the following disclaimer in the 121592Srgrimes * documentation and/or other materials provided with the distribution. 131592Srgrimes * 3. All advertising materials mentioning features or use of this software 141592Srgrimes * must display the following acknowledgement: 151592Srgrimes * This product includes software developed by the University of 161592Srgrimes * California, Berkeley and its contributors. 171592Srgrimes * 4. Neither the name of the University nor the names of its contributors 181592Srgrimes * may be used to endorse or promote products derived from this software 191592Srgrimes * without specific prior written permission. 201592Srgrimes * 211592Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221592Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231592Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241592Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251592Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261592Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271592Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281592Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291592Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301592Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311592Srgrimes * SUCH DAMAGE. 321592Srgrimes * 331592Srgrimes * $Id: rshd.c,v 1.14 1997/03/28 15:48:17 imp Exp $ 3450476Speter */ 351592Srgrimes 361592Srgrimes#ifndef lint 3789920Sumestatic char copyright[] = 3889920Sume"@(#) Copyright (c) 1988, 1989, 1992, 1993, 1994\n\ 3989920Sume The Regents of the University of California. All rights reserved.\n"; 4090148Simp#endif /* not lint */ 4190148Simp 4290148Simp#ifndef lint 4390148Simpstatic char sccsid[] = "@(#)rshd.c 8.2 (Berkeley) 4/6/94"; 4490148Simp#endif /* not lint */ 4590148Simp 4690148Simp/* 4790148Simp * remote shell server: 4890148Simp * [port]\0 49186405Scperciva * remuser\0 5090158Skris * locuser\0 5190148Simp * command\0 5290148Simp * data 5390148Simp */ 5490148Simp#include <sys/param.h> 5590148Simp#include <sys/ioctl.h> 5690148Simp#include <sys/time.h> 5790148Simp#include <sys/socket.h> 5890148Simp 5990148Simp#include <netinet/in_systm.h> 6090148Simp#include <netinet/in.h> 6190158Skris#include <netinet/ip.h> 6290148Simp#include <arpa/inet.h> 6390148Simp#include <netdb.h> 6413139Speter 6590148Simp#include <errno.h> 6613139Speter#include <fcntl.h> 6790148Simp#include <paths.h> 6890148Simp#include <pwd.h> 6990148Simp#include <signal.h> 7090148Simp#include <stdio.h> 7190148Simp#include <stdlib.h> 7290148Simp#include <string.h> 7390148Simp#include <syslog.h> 7490148Simp#include <unistd.h> 7556668Sshin 7656668Sshinint keepalive = 1; 7756668Sshinint check_all; 7856668Sshinint log_success; /* If TRUE, log all successful accesses */ 7956668Sshinint sent_null; 8056668Sshin 8156668Sshinvoid doit __P((struct sockaddr_in *)); 8256668Sshinvoid error __P((const char *, ...)); 8356668Sshinvoid getstr __P((char *, int, char *)); 8456668Sshinint local_domain __P((char *)); 8556668Sshinchar *topdomain __P((char *)); 8656668Sshinvoid usage __P((void)); 8756668Sshin 8856668Sshin#ifdef KERBEROS 8956668Sshin#include <des.h> 90#include <kerberosIV/krb.h> 91#define VERSION_SIZE 9 92#define SECURE_MESSAGE "This rsh session is using DES encryption for all transmissions.\r\n" 93#define OPTIONS "alnkvxL" 94char authbuf[sizeof(AUTH_DAT)]; 95char tickbuf[sizeof(KTEXT_ST)]; 96int doencrypt, use_kerberos, vacuous; 97Key_schedule schedule; 98#else 99#define OPTIONS "alnL" 100#endif 101 102int 103main(argc, argv) 104 int argc; 105 char *argv[]; 106{ 107 extern int __check_rhosts_file; 108 struct linger linger; 109 int ch, on = 1, fromlen; 110 struct sockaddr_in from; 111 112 openlog("rshd", LOG_PID | LOG_ODELAY, LOG_DAEMON); 113 114 opterr = 0; 115 while ((ch = getopt(argc, argv, OPTIONS)) != -1) 116 switch (ch) { 117 case 'a': 118 check_all = 1; 119 break; 120 case 'l': 121 __check_rhosts_file = 0; 122 break; 123 case 'n': 124 keepalive = 0; 125 break; 126#ifdef KERBEROS 127 case 'k': 128 use_kerberos = 1; 129 break; 130 131 case 'v': 132 vacuous = 1; 133 break; 134 135#ifdef CRYPT 136 case 'x': 137 doencrypt = 1; 138 break; 139#endif 140#endif 141 case 'L': 142 log_success = 1; 143 break; 144 case '?': 145 default: 146 usage(); 147 break; 148 } 149 150 argc -= optind; 151 argv += optind; 152 153#ifdef KERBEROS 154 if (use_kerberos && vacuous) { 155 syslog(LOG_ERR, "only one of -k and -v allowed"); 156 exit(2); 157 } 158#ifdef CRYPT 159 if (doencrypt && !use_kerberos) { 160 syslog(LOG_ERR, "-k is required for -x"); 161 exit(2); 162 } 163#endif 164#endif 165 166 fromlen = sizeof (from); 167 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) { 168 syslog(LOG_ERR, "getpeername: %m"); 169 _exit(1); 170 } 171 if (keepalive && 172 setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, (char *)&on, 173 sizeof(on)) < 0) 174 syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m"); 175 linger.l_onoff = 1; 176 linger.l_linger = 60; /* XXX */ 177 if (setsockopt(0, SOL_SOCKET, SO_LINGER, (char *)&linger, 178 sizeof (linger)) < 0) 179 syslog(LOG_WARNING, "setsockopt (SO_LINGER): %m"); 180 doit(&from); 181 /* NOTREACHED */ 182} 183 184char username[20] = "USER="; 185char homedir[64] = "HOME="; 186char shell[64] = "SHELL="; 187char path[100] = "PATH="; 188char *envinit[] = 189 {homedir, shell, path, username, 0}; 190char **environ; 191 192void 193doit(fromp) 194 struct sockaddr_in *fromp; 195{ 196 extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */ 197 struct hostent *hp; 198 struct passwd *pwd; 199 u_short port; 200 fd_set ready, readfrom; 201 int cc, nfd, pv[2], pid, s; 202 int one = 1; 203 char *hostname, *errorstr, *errorhost; 204 char *cp, sig, buf[BUFSIZ]; 205 char cmdbuf[NCARGS+1], locuser[16], remuser[16]; 206 char remotehost[2 * MAXHOSTNAMELEN + 1]; 207 char fromhost[2 * MAXHOSTNAMELEN + 1]; 208 209#ifdef KERBEROS 210 AUTH_DAT *kdata = (AUTH_DAT *) NULL; 211 KTEXT ticket = (KTEXT) NULL; 212 char instance[INST_SZ], version[VERSION_SIZE]; 213 struct sockaddr_in fromaddr; 214 int rc; 215 long authopts; 216 int pv1[2], pv2[2]; 217 fd_set wready, writeto; 218 219 fromaddr = *fromp; 220#endif 221 222 (void) signal(SIGINT, SIG_DFL); 223 (void) signal(SIGQUIT, SIG_DFL); 224 (void) signal(SIGTERM, SIG_DFL); 225#ifdef DEBUG 226 { int t = open(_PATH_TTY, 2); 227 if (t >= 0) { 228 ioctl(t, TIOCNOTTY, (char *)0); 229 (void) close(t); 230 } 231 } 232#endif 233 fromp->sin_port = ntohs((u_short)fromp->sin_port); 234 if (fromp->sin_family != AF_INET) { 235 syslog(LOG_ERR, "malformed \"from\" address (af %d)\n", 236 fromp->sin_family); 237 exit(1); 238 } 239#ifdef IP_OPTIONS 240 { 241 u_char optbuf[BUFSIZ/3]; 242 int optsize = sizeof(optbuf), ipproto, i; 243 struct protoent *ip; 244 245 if ((ip = getprotobyname("ip")) != NULL) 246 ipproto = ip->p_proto; 247 else 248 ipproto = IPPROTO_IP; 249 if (!getsockopt(0, ipproto, IP_OPTIONS, (char *)optbuf, &optsize) && 250 optsize != 0) { 251 for (i = 0; i < optsize; ) { 252 u_char c = optbuf[i]; 253 if (c == IPOPT_LSRR || c == IPOPT_SSRR) { 254 syslog(LOG_NOTICE, 255 "Connection refused from %s with IP option %s", 256 inet_ntoa(fromp->sin_addr), 257 c == IPOPT_LSRR ? "LSRR" : "SSRR"); 258 exit(1); 259 } 260 if (c == IPOPT_EOL) 261 break; 262 i += (c == IPOPT_NOP) ? 1 : optbuf[i+1]; 263 } 264 } 265 } 266#endif 267 268#ifdef KERBEROS 269 if (!use_kerberos) 270#endif 271 if (fromp->sin_port >= IPPORT_RESERVED || 272 fromp->sin_port < IPPORT_RESERVED/2) { 273 syslog(LOG_NOTICE|LOG_AUTH, 274 "Connection from %s on illegal port %u", 275 inet_ntoa(fromp->sin_addr), 276 fromp->sin_port); 277 exit(1); 278 } 279 280 (void) alarm(60); 281 port = 0; 282 for (;;) { 283 char c; 284 if ((cc = read(STDIN_FILENO, &c, 1)) != 1) { 285 if (cc < 0) 286 syslog(LOG_NOTICE, "read: %m"); 287 shutdown(0, 1+1); 288 exit(1); 289 } 290 if (c== 0) 291 break; 292 port = port * 10 + c - '0'; 293 } 294 295 (void) alarm(0); 296 if (port != 0) { 297 int lport = IPPORT_RESERVED - 1; 298 s = rresvport(&lport); 299 if (s < 0) { 300 syslog(LOG_ERR, "can't get stderr port: %m"); 301 exit(1); 302 } 303#ifdef KERBEROS 304 if (!use_kerberos) 305#endif 306 if (port >= IPPORT_RESERVED || 307 port < IPPORT_RESERVED/2) { 308 syslog(LOG_NOTICE|LOG_AUTH, 309 "2nd socket from %s on unreserved port %u", 310 inet_ntoa(fromp->sin_addr), 311 port); 312 exit(1); 313 } 314 fromp->sin_port = htons(port); 315 if (connect(s, (struct sockaddr *)fromp, sizeof (*fromp)) < 0) { 316 syslog(LOG_INFO, "connect second port %d: %m", port); 317 exit(1); 318 } 319 } 320 321#ifdef KERBEROS 322 if (vacuous) { 323 error("rshd: remote host requires Kerberos authentication\n"); 324 exit(1); 325 } 326#endif 327 328#ifdef notdef 329 /* from inetd, socket is already on 0, 1, 2 */ 330 dup2(f, 0); 331 dup2(f, 1); 332 dup2(f, 2); 333#endif 334 errorstr = NULL; 335 hp = gethostbyaddr((char *)&fromp->sin_addr, sizeof (struct in_addr), 336 fromp->sin_family); 337 if (hp) { 338 /* 339 * If name returned by gethostbyaddr is in our domain, 340 * attempt to verify that we haven't been fooled by someone 341 * in a remote net; look up the name and check that this 342 * address corresponds to the name. 343 */ 344 strncpy(fromhost, hp->h_name, sizeof(fromhost) - 1); 345 fromhost[sizeof(fromhost) - 1] = 0; 346 hostname = fromhost; 347#ifdef KERBEROS 348 if (!use_kerberos) 349#endif 350 if (check_all || local_domain(hp->h_name)) { 351 strncpy(remotehost, hp->h_name, sizeof(remotehost) - 1); 352 remotehost[sizeof(remotehost) - 1] = 0; 353 errorhost = remotehost; 354 hp = gethostbyname(remotehost); 355 if (hp == NULL) { 356 syslog(LOG_INFO, 357 "Couldn't look up address for %s", 358 remotehost); 359 errorstr = 360 "Couldn't look up address for your host (%s)\n"; 361 strncpy(fromhost, inet_ntoa(fromp->sin_addr), 362 sizeof(fromhost) - 1); 363 fromhost[sizeof(fromhost) - 1] = 0; 364 hostname = fromhost; 365 } else for (; ; hp->h_addr_list++) { 366 if (hp->h_addr_list[0] == NULL) { 367 syslog(LOG_NOTICE, 368 "Host addr %s not listed for host %s", 369 inet_ntoa(fromp->sin_addr), 370 hp->h_name); 371 errorstr = 372 "Host address mismatch for %s\n"; 373 strncpy(fromhost, inet_ntoa(fromp->sin_addr), 374 sizeof(fromhost) - 1); 375 fromhost[sizeof(fromhost) - 1] = 0; 376 hostname = fromhost; 377 break; 378 } 379 if (!bcmp(hp->h_addr_list[0], 380 (caddr_t)&fromp->sin_addr, 381 sizeof(fromp->sin_addr))) { 382 hostname = remotehost; 383 break; 384 } 385 } 386 } 387 } else { 388 strncpy(fromhost, inet_ntoa(fromp->sin_addr), 389 sizeof(fromhost) - 1); 390 fromhost[sizeof(fromhost) - 1] = 0; 391 errorhost = hostname = fromhost; 392 } 393 394#ifdef KERBEROS 395 if (use_kerberos) { 396 kdata = (AUTH_DAT *) authbuf; 397 ticket = (KTEXT) tickbuf; 398 authopts = 0L; 399 strcpy(instance, "*"); 400 version[VERSION_SIZE - 1] = '\0'; 401#ifdef CRYPT 402 if (doencrypt) { 403 struct sockaddr_in local_addr; 404 rc = sizeof(local_addr); 405 if (getsockname(0, (struct sockaddr *)&local_addr, 406 &rc) < 0) { 407 syslog(LOG_ERR, "getsockname: %m"); 408 error("rlogind: getsockname: %m"); 409 exit(1); 410 } 411 authopts = KOPT_DO_MUTUAL; 412 rc = krb_recvauth(authopts, 0, ticket, 413 "rcmd", instance, &fromaddr, 414 &local_addr, kdata, "", schedule, 415 version); 416 des_set_key_krb(&kdata->session, schedule); 417 } else 418#endif 419 rc = krb_recvauth(authopts, 0, ticket, "rcmd", 420 instance, &fromaddr, 421 (struct sockaddr_in *) 0, 422 kdata, "", NULL, version); 423 if (rc != KSUCCESS) { 424 error("Kerberos authentication failure: %s\n", 425 krb_err_txt[rc]); 426 exit(1); 427 } 428 } else 429#endif 430 getstr(remuser, sizeof(remuser), "remuser"); 431 432 getstr(locuser, sizeof(locuser), "locuser"); 433 getstr(cmdbuf, sizeof(cmdbuf), "command"); 434 setpwent(); 435 pwd = getpwnam(locuser); 436 if (pwd == NULL) { 437 syslog(LOG_INFO|LOG_AUTH, 438 "%s@%s as %s: unknown login. cmd='%.80s'", 439 remuser, hostname, locuser, cmdbuf); 440 if (errorstr == NULL) 441 errorstr = "Login incorrect.\n"; 442 goto fail; 443 } 444 if (chdir(pwd->pw_dir) < 0) { 445 (void) chdir("/"); 446#ifdef notdef 447 syslog(LOG_INFO|LOG_AUTH, 448 "%s@%s as %s: no home directory. cmd='%.80s'", 449 remuser, hostname, locuser, cmdbuf); 450 error("No remote directory.\n"); 451 exit(1); 452#endif 453 } 454 455#ifdef KERBEROS 456 if (use_kerberos) { 457 if (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0') { 458 if (kuserok(kdata, locuser) != 0) { 459 syslog(LOG_INFO|LOG_AUTH, 460 "Kerberos rsh denied to %s.%s@%s", 461 kdata->pname, kdata->pinst, kdata->prealm); 462 error("Permission denied.\n"); 463 exit(1); 464 } 465 } 466 } else 467#endif 468 469 if (errorstr || 470 (pwd->pw_expire && time(NULL) >= pwd->pw_expire) || 471 (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' && 472 iruserok(fromp->sin_addr.s_addr, pwd->pw_uid == 0, 473 remuser, locuser) < 0)) { 474 if (__rcmd_errstr) 475 syslog(LOG_INFO|LOG_AUTH, 476 "%s@%s as %s: permission denied (%s). cmd='%.80s'", 477 remuser, hostname, locuser, __rcmd_errstr, 478 cmdbuf); 479 else 480 syslog(LOG_INFO|LOG_AUTH, 481 "%s@%s as %s: permission denied. cmd='%.80s'", 482 remuser, hostname, locuser, cmdbuf); 483fail: 484 if (errorstr == NULL) 485 errorstr = "Permission denied.\n"; 486 error(errorstr, errorhost); 487 exit(1); 488 } 489 490 if (pwd->pw_uid && !access(_PATH_NOLOGIN, F_OK)) { 491 error("Logins currently disabled.\n"); 492 exit(1); 493 } 494#if BSD > 43 495 /* before fork, while we're session leader */ 496 if (setlogin(pwd->pw_name) < 0) 497 syslog(LOG_ERR, "setlogin() failed: %m"); 498#endif 499 500 (void) write(STDERR_FILENO, "\0", 1); 501 sent_null = 1; 502 503 if (port) { 504 if (pipe(pv) < 0) { 505 error("Can't make pipe.\n"); 506 exit(1); 507 } 508#ifdef CRYPT 509#ifdef KERBEROS 510 if (doencrypt) { 511 if (pipe(pv1) < 0) { 512 error("Can't make 2nd pipe.\n"); 513 exit(1); 514 } 515 if (pipe(pv2) < 0) { 516 error("Can't make 3rd pipe.\n"); 517 exit(1); 518 } 519 } 520#endif 521#endif 522 pid = fork(); 523 if (pid == -1) { 524 error("Can't fork; try again.\n"); 525 exit(1); 526 } 527 if (pid) { 528#ifdef CRYPT 529#ifdef KERBEROS 530 if (doencrypt) { 531 static char msg[] = SECURE_MESSAGE; 532 (void) close(pv1[1]); 533 (void) close(pv2[1]); 534 des_write(s, msg, sizeof(msg) - 1); 535 536 } else 537#endif 538#endif 539 { 540 (void) close(0); 541 (void) close(1); 542 } 543 (void) close(2); 544 (void) close(pv[1]); 545 546 FD_ZERO(&readfrom); 547 FD_SET(s, &readfrom); 548 FD_SET(pv[0], &readfrom); 549 if (pv[0] > s) 550 nfd = pv[0]; 551 else 552 nfd = s; 553#ifdef CRYPT 554#ifdef KERBEROS 555 if (doencrypt) { 556 FD_ZERO(&writeto); 557 FD_SET(pv2[0], &writeto); 558 FD_SET(pv1[0], &readfrom); 559 560 nfd = MAX(nfd, pv2[0]); 561 nfd = MAX(nfd, pv1[0]); 562 } else 563#endif 564#endif 565 ioctl(pv[0], FIONBIO, (char *)&one); 566 567 /* should set s nbio! */ 568 nfd++; 569 do { 570 ready = readfrom; 571#ifdef CRYPT 572#ifdef KERBEROS 573 if (doencrypt) { 574 wready = writeto; 575 if (select(nfd, &ready, 576 &wready, (fd_set *) 0, 577 (struct timeval *) 0) < 0) 578 break; 579 } else 580#endif 581#endif 582 if (select(nfd, &ready, (fd_set *)0, 583 (fd_set *)0, (struct timeval *)0) < 0) 584 break; 585 if (FD_ISSET(s, &ready)) { 586 int ret; 587#ifdef CRYPT 588#ifdef KERBEROS 589 if (doencrypt) 590 ret = des_read(s, &sig, 1); 591 else 592#endif 593#endif 594 ret = read(s, &sig, 1); 595 if (ret <= 0) 596 FD_CLR(s, &readfrom); 597 else 598 killpg(pid, sig); 599 } 600 if (FD_ISSET(pv[0], &ready)) { 601 errno = 0; 602 cc = read(pv[0], buf, sizeof(buf)); 603 if (cc <= 0) { 604 shutdown(s, 1+1); 605 FD_CLR(pv[0], &readfrom); 606 } else { 607#ifdef CRYPT 608#ifdef KERBEROS 609 if (doencrypt) 610 (void) 611 des_write(s, buf, cc); 612 else 613#endif 614#endif 615 (void) 616 write(s, buf, cc); 617 } 618 } 619#ifdef CRYPT 620#ifdef KERBEROS 621 if (doencrypt && FD_ISSET(pv1[0], &ready)) { 622 errno = 0; 623 cc = read(pv1[0], buf, sizeof(buf)); 624 if (cc <= 0) { 625 shutdown(pv1[0], 1+1); 626 FD_CLR(pv1[0], &readfrom); 627 } else 628 (void) des_write(STDOUT_FILENO, 629 buf, cc); 630 } 631 632 if (doencrypt && FD_ISSET(pv2[0], &wready)) { 633 errno = 0; 634 cc = des_read(STDIN_FILENO, 635 buf, sizeof(buf)); 636 if (cc <= 0) { 637 shutdown(pv2[0], 1+1); 638 FD_CLR(pv2[0], &writeto); 639 } else 640 (void) write(pv2[0], buf, cc); 641 } 642#endif 643#endif 644 645 } while (FD_ISSET(s, &readfrom) || 646#ifdef CRYPT 647#ifdef KERBEROS 648 (doencrypt && FD_ISSET(pv1[0], &readfrom)) || 649#endif 650#endif 651 FD_ISSET(pv[0], &readfrom)); 652 exit(0); 653 } 654 setpgrp(0, getpid()); 655 (void) close(s); 656 (void) close(pv[0]); 657#ifdef CRYPT 658#ifdef KERBEROS 659 if (doencrypt) { 660 close(pv1[0]); close(pv2[0]); 661 dup2(pv1[1], 1); 662 dup2(pv2[1], 0); 663 close(pv1[1]); 664 close(pv2[1]); 665 } 666#endif 667#endif 668 dup2(pv[1], 2); 669 close(pv[1]); 670 } 671 if (*pwd->pw_shell == '\0') 672 pwd->pw_shell = _PATH_BSHELL; 673 (void) setgid((gid_t)pwd->pw_gid); 674 initgroups(pwd->pw_name, pwd->pw_gid); 675 (void) setuid((uid_t)pwd->pw_uid); 676 environ = envinit; 677 strncat(homedir, pwd->pw_dir, sizeof(homedir)-6); 678 strcat(path, _PATH_DEFPATH); 679 strncat(shell, pwd->pw_shell, sizeof(shell)-7); 680 strncat(username, pwd->pw_name, sizeof(username)-6); 681 cp = strrchr(pwd->pw_shell, '/'); 682 if (cp) 683 cp++; 684 else 685 cp = pwd->pw_shell; 686 endpwent(); 687 if (log_success || pwd->pw_uid == 0) { 688#ifdef KERBEROS 689 if (use_kerberos) 690 syslog(LOG_INFO|LOG_AUTH, 691 "Kerberos shell from %s.%s@%s on %s as %s, cmd='%.80s'", 692 kdata->pname, kdata->pinst, kdata->prealm, 693 hostname, locuser, cmdbuf); 694 else 695#endif 696 syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'", 697 remuser, hostname, locuser, cmdbuf); 698 } 699 execl(pwd->pw_shell, cp, "-c", cmdbuf, 0); 700 perror(pwd->pw_shell); 701 exit(1); 702} 703 704/* 705 * Report error to client. Note: can't be used until second socket has 706 * connected to client, or older clients will hang waiting for that 707 * connection first. 708 */ 709#if __STDC__ 710#include <stdarg.h> 711#else 712#include <varargs.h> 713#endif 714 715void 716#if __STDC__ 717error(const char *fmt, ...) 718#else 719error(fmt, va_alist) 720 char *fmt; 721 va_dcl 722#endif 723{ 724 va_list ap; 725 int len; 726 char *bp, buf[BUFSIZ]; 727#if __STDC__ 728 va_start(ap, fmt); 729#else 730 va_start(ap); 731#endif 732 bp = buf; 733 if (sent_null == 0) { 734 *bp++ = 1; 735 len = 1; 736 } else 737 len = 0; 738 (void)vsnprintf(bp, sizeof(buf) - 1, fmt, ap); 739 (void)write(STDERR_FILENO, buf, len + strlen(bp)); 740} 741 742void 743getstr(buf, cnt, err) 744 char *buf, *err; 745 int cnt; 746{ 747 char c; 748 749 do { 750 if (read(STDIN_FILENO, &c, 1) != 1) 751 exit(1); 752 *buf++ = c; 753 if (--cnt == 0) { 754 error("%s too long\n", err); 755 exit(1); 756 } 757 } while (c != 0); 758} 759 760/* 761 * Check whether host h is in our local domain, 762 * defined as sharing the last two components of the domain part, 763 * or the entire domain part if the local domain has only one component. 764 * If either name is unqualified (contains no '.'), 765 * assume that the host is local, as it will be 766 * interpreted as such. 767 */ 768int 769local_domain(h) 770 char *h; 771{ 772 char localhost[MAXHOSTNAMELEN]; 773 char *p1, *p2; 774 775 localhost[0] = 0; 776 (void) gethostname(localhost, sizeof(localhost)); 777 p1 = topdomain(localhost); 778 p2 = topdomain(h); 779 if (p1 == NULL || p2 == NULL || !strcasecmp(p1, p2)) 780 return (1); 781 return (0); 782} 783 784char * 785topdomain(h) 786 char *h; 787{ 788 char *p, *maybe = NULL; 789 int dots = 0; 790 791 for (p = h + strlen(h); p >= h; p--) { 792 if (*p == '.') { 793 if (++dots == 2) 794 return (p); 795 maybe = p; 796 } 797 } 798 return (maybe); 799} 800 801void 802usage() 803{ 804 805 syslog(LOG_ERR, "usage: rshd [-%s]", OPTIONS); 806 exit(2); 807} 808