rshd.c revision 35728
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 "$Id: rshd.c,v 1.20 1997/12/02 12:30:04 charnier Exp $"; 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 <arpa/inet.h> 65#include <netdb.h> 66 67#include <errno.h> 68#include <fcntl.h> 69#include <paths.h> 70#include <pwd.h> 71#include <signal.h> 72#include <stdio.h> 73#include <stdlib.h> 74#include <string.h> 75#include <syslog.h> 76#include <unistd.h> 77#ifdef LOGIN_CAP 78#include <login_cap.h> 79#endif 80 81int keepalive = 1; 82int check_all; 83int log_success; /* If TRUE, log all successful accesses */ 84int sent_null; 85 86void doit __P((struct sockaddr_in *)); 87void error __P((const char *, ...)); 88void getstr __P((char *, int, char *)); 89int local_domain __P((char *)); 90char *topdomain __P((char *)); 91void usage __P((void)); 92 93#ifdef KERBEROS 94#include <des.h> 95#include <krb.h> 96#define VERSION_SIZE 9 97#define SECURE_MESSAGE "This rsh session is using DES encryption for all transmissions.\r\n" 98#define OPTIONS "alnkvxL" 99char authbuf[sizeof(AUTH_DAT)]; 100char tickbuf[sizeof(KTEXT_ST)]; 101int doencrypt, use_kerberos, vacuous; 102Key_schedule schedule; 103#else 104#define OPTIONS "alnL" 105#endif 106 107int 108main(argc, argv) 109 int argc; 110 char *argv[]; 111{ 112 extern int __check_rhosts_file; 113 struct linger linger; 114 int ch, on = 1, fromlen; 115 struct sockaddr_in from; 116 117 openlog("rshd", LOG_PID | LOG_ODELAY, LOG_DAEMON); 118 119 opterr = 0; 120 while ((ch = getopt(argc, argv, OPTIONS)) != -1) 121 switch (ch) { 122 case 'a': 123 check_all = 1; 124 break; 125 case 'l': 126 __check_rhosts_file = 0; 127 break; 128 case 'n': 129 keepalive = 0; 130 break; 131#ifdef KERBEROS 132 case 'k': 133 use_kerberos = 1; 134 break; 135 136 case 'v': 137 vacuous = 1; 138 break; 139 140#ifdef CRYPT 141 case 'x': 142 doencrypt = 1; 143 break; 144#endif 145#endif 146 case 'L': 147 log_success = 1; 148 break; 149 case '?': 150 default: 151 usage(); 152 break; 153 } 154 155 argc -= optind; 156 argv += optind; 157 158#ifdef KERBEROS 159 if (use_kerberos && vacuous) { 160 syslog(LOG_ERR, "only one of -k and -v allowed"); 161 exit(2); 162 } 163#ifdef CRYPT 164 if (doencrypt && !use_kerberos) { 165 syslog(LOG_ERR, "-k is required for -x"); 166 exit(2); 167 } 168#endif 169#endif 170 171 fromlen = sizeof (from); 172 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) { 173 syslog(LOG_ERR, "getpeername: %m"); 174 exit(1); 175 } 176 if (keepalive && 177 setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, (char *)&on, 178 sizeof(on)) < 0) 179 syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m"); 180 linger.l_onoff = 1; 181 linger.l_linger = 60; /* XXX */ 182 if (setsockopt(0, SOL_SOCKET, SO_LINGER, (char *)&linger, 183 sizeof (linger)) < 0) 184 syslog(LOG_WARNING, "setsockopt (SO_LINGER): %m"); 185 doit(&from); 186 /* NOTREACHED */ 187 return(0); 188} 189 190char username[20] = "USER="; 191char homedir[64] = "HOME="; 192char shell[64] = "SHELL="; 193char path[100] = "PATH="; 194char *envinit[] = 195 {homedir, shell, path, username, 0}; 196char **environ; 197 198void 199doit(fromp) 200 struct sockaddr_in *fromp; 201{ 202 extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */ 203 struct hostent *hp; 204 struct passwd *pwd; 205 u_short port; 206 fd_set ready, readfrom; 207 int cc, nfd, pv[2], pid, s; 208 int one = 1; 209 char *hostname, *errorstr, *errorhost; 210 char *cp, sig, buf[BUFSIZ]; 211 char cmdbuf[NCARGS+1], locuser[16], remuser[16]; 212 char remotehost[2 * MAXHOSTNAMELEN + 1]; 213 char fromhost[2 * MAXHOSTNAMELEN + 1]; 214#ifdef LOGIN_CAP 215 login_cap_t *lc; 216#endif 217 218#ifdef KERBEROS 219 AUTH_DAT *kdata = (AUTH_DAT *) NULL; 220 KTEXT ticket = (KTEXT) NULL; 221 char instance[INST_SZ], version[VERSION_SIZE]; 222 struct sockaddr_in fromaddr; 223 int rc; 224 long authopts; 225 int pv1[2], pv2[2]; 226 fd_set wready, writeto; 227 228 fromaddr = *fromp; 229#endif 230 231 (void) signal(SIGINT, SIG_DFL); 232 (void) signal(SIGQUIT, SIG_DFL); 233 (void) signal(SIGTERM, SIG_DFL); 234#ifdef DEBUG 235 { int t = open(_PATH_TTY, 2); 236 if (t >= 0) { 237 ioctl(t, TIOCNOTTY, (char *)0); 238 (void) close(t); 239 } 240 } 241#endif 242 fromp->sin_port = ntohs((u_short)fromp->sin_port); 243 if (fromp->sin_family != AF_INET) { 244 syslog(LOG_ERR, "malformed \"from\" address (af %d)", 245 fromp->sin_family); 246 exit(1); 247 } 248#ifdef IP_OPTIONS 249 { 250 u_char optbuf[BUFSIZ/3]; 251 int optsize = sizeof(optbuf), ipproto, i; 252 struct protoent *ip; 253 254 if ((ip = getprotobyname("ip")) != NULL) 255 ipproto = ip->p_proto; 256 else 257 ipproto = IPPROTO_IP; 258 if (!getsockopt(0, ipproto, IP_OPTIONS, (char *)optbuf, &optsize) && 259 optsize != 0) { 260 for (i = 0; i < optsize; ) { 261 u_char c = optbuf[i]; 262 if (c == IPOPT_LSRR || c == IPOPT_SSRR) { 263 syslog(LOG_NOTICE, 264 "connection refused from %s with IP option %s", 265 inet_ntoa(fromp->sin_addr), 266 c == IPOPT_LSRR ? "LSRR" : "SSRR"); 267 exit(1); 268 } 269 if (c == IPOPT_EOL) 270 break; 271 i += (c == IPOPT_NOP) ? 1 : optbuf[i+1]; 272 } 273 } 274 } 275#endif 276 277#ifdef KERBEROS 278 if (!use_kerberos) 279#endif 280 if (fromp->sin_port >= IPPORT_RESERVED || 281 fromp->sin_port < IPPORT_RESERVED/2) { 282 syslog(LOG_NOTICE|LOG_AUTH, 283 "connection from %s on illegal port %u", 284 inet_ntoa(fromp->sin_addr), 285 fromp->sin_port); 286 exit(1); 287 } 288 289 (void) alarm(60); 290 port = 0; 291 for (;;) { 292 char c; 293 if ((cc = read(STDIN_FILENO, &c, 1)) != 1) { 294 if (cc < 0) 295 syslog(LOG_NOTICE, "read: %m"); 296 shutdown(0, 1+1); 297 exit(1); 298 } 299 if (c== 0) 300 break; 301 port = port * 10 + c - '0'; 302 } 303 304 (void) alarm(0); 305 if (port != 0) { 306 int lport = IPPORT_RESERVED - 1; 307 s = rresvport(&lport); 308 if (s < 0) { 309 syslog(LOG_ERR, "can't get stderr port: %m"); 310 exit(1); 311 } 312#ifdef KERBEROS 313 if (!use_kerberos) 314#endif 315 if (port >= IPPORT_RESERVED || 316 port < IPPORT_RESERVED/2) { 317 syslog(LOG_NOTICE|LOG_AUTH, 318 "2nd socket from %s on unreserved port %u", 319 inet_ntoa(fromp->sin_addr), 320 port); 321 exit(1); 322 } 323 fromp->sin_port = htons(port); 324 if (connect(s, (struct sockaddr *)fromp, sizeof (*fromp)) < 0) { 325 syslog(LOG_INFO, "connect second port %d: %m", port); 326 exit(1); 327 } 328 } 329 330#ifdef KERBEROS 331 if (vacuous) { 332 error("rshd: remote host requires Kerberos authentication\n"); 333 exit(1); 334 } 335#endif 336 337#ifdef notdef 338 /* from inetd, socket is already on 0, 1, 2 */ 339 dup2(f, 0); 340 dup2(f, 1); 341 dup2(f, 2); 342#endif 343 errorstr = NULL; 344 hp = gethostbyaddr((char *)&fromp->sin_addr, sizeof (struct in_addr), 345 fromp->sin_family); 346 if (hp) { 347 /* 348 * If name returned by gethostbyaddr is in our domain, 349 * attempt to verify that we haven't been fooled by someone 350 * in a remote net; look up the name and check that this 351 * address corresponds to the name. 352 */ 353 strncpy(fromhost, hp->h_name, sizeof(fromhost) - 1); 354 fromhost[sizeof(fromhost) - 1] = 0; 355 hostname = fromhost; 356#ifdef KERBEROS 357 if (!use_kerberos) 358#endif 359 if (check_all || local_domain(hp->h_name)) { 360 strncpy(remotehost, hp->h_name, sizeof(remotehost) - 1); 361 remotehost[sizeof(remotehost) - 1] = 0; 362 errorhost = remotehost; 363 hp = gethostbyname(remotehost); 364 if (hp == NULL) { 365 syslog(LOG_INFO, 366 "couldn't look up address for %s", 367 remotehost); 368 errorstr = 369 "Couldn't look up address for your host (%s)\n"; 370 strncpy(fromhost, inet_ntoa(fromp->sin_addr), 371 sizeof(fromhost) - 1); 372 fromhost[sizeof(fromhost) - 1] = 0; 373 hostname = fromhost; 374 } else for (; ; hp->h_addr_list++) { 375 if (hp->h_addr_list[0] == NULL) { 376 syslog(LOG_NOTICE, 377 "host addr %s not listed for host %s", 378 inet_ntoa(fromp->sin_addr), 379 hp->h_name); 380 errorstr = 381 "Host address mismatch for %s\n"; 382 strncpy(fromhost, inet_ntoa(fromp->sin_addr), 383 sizeof(fromhost) - 1); 384 fromhost[sizeof(fromhost) - 1] = 0; 385 hostname = fromhost; 386 break; 387 } 388 if (!bcmp(hp->h_addr_list[0], 389 (caddr_t)&fromp->sin_addr, 390 sizeof(fromp->sin_addr))) { 391 hostname = remotehost; 392 break; 393 } 394 } 395 } 396 } else { 397 strncpy(fromhost, inet_ntoa(fromp->sin_addr), 398 sizeof(fromhost) - 1); 399 fromhost[sizeof(fromhost) - 1] = 0; 400 errorhost = hostname = fromhost; 401 } 402 403#ifdef KERBEROS 404 if (use_kerberos) { 405 kdata = (AUTH_DAT *) authbuf; 406 ticket = (KTEXT) tickbuf; 407 authopts = 0L; 408 strcpy(instance, "*"); 409 version[VERSION_SIZE - 1] = '\0'; 410#ifdef CRYPT 411 if (doencrypt) { 412 struct sockaddr_in local_addr; 413 rc = sizeof(local_addr); 414 if (getsockname(0, (struct sockaddr *)&local_addr, 415 &rc) < 0) { 416 syslog(LOG_ERR, "getsockname: %m"); 417 error("rlogind: getsockname: %m"); 418 exit(1); 419 } 420 authopts = KOPT_DO_MUTUAL; 421 rc = krb_recvauth(authopts, 0, ticket, 422 "rcmd", instance, &fromaddr, 423 &local_addr, kdata, "", schedule, 424 version); 425 des_set_key(&kdata->session, schedule); 426 } else 427#endif 428 rc = krb_recvauth(authopts, 0, ticket, "rcmd", 429 instance, &fromaddr, 430 (struct sockaddr_in *) 0, 431 kdata, "", NULL, version); 432 if (rc != KSUCCESS) { 433 error("Kerberos authentication failure: %s\n", 434 krb_err_txt[rc]); 435 exit(1); 436 } 437 } else 438#endif 439 getstr(remuser, sizeof(remuser), "remuser"); 440 441 getstr(locuser, sizeof(locuser), "locuser"); 442 getstr(cmdbuf, sizeof(cmdbuf), "command"); 443 setpwent(); 444 pwd = getpwnam(locuser); 445 if (pwd == NULL) { 446 syslog(LOG_INFO|LOG_AUTH, 447 "%s@%s as %s: unknown login. cmd='%.80s'", 448 remuser, hostname, locuser, cmdbuf); 449 if (errorstr == NULL) 450 errorstr = "Login incorrect.\n"; 451 goto fail; 452 } 453#ifdef LOGIN_CAP 454 lc = login_getpwclass(pwd); 455#endif 456 if (chdir(pwd->pw_dir) < 0) { 457#ifdef LOGIN_CAP 458 if (chdir("/") < 0 || 459 login_getcapbool(lc, "requirehome", !!pwd->pw_uid)) { 460 syslog(LOG_INFO|LOG_AUTH, 461 "%s@%s as %s: no home directory. cmd='%.80s'", 462 remuser, hostname, locuser, cmdbuf); 463 error("No remote home directory.\n"); 464 exit(0); 465 } 466#else 467 (void) chdir("/"); 468#ifdef notdef 469 syslog(LOG_INFO|LOG_AUTH, 470 "%s@%s as %s: no home directory. cmd='%.80s'", 471 remuser, hostname, locuser, cmdbuf); 472 error("No remote directory.\n"); 473 exit(1); 474#endif 475#endif 476 pwd->pw_dir = "/"; 477 } 478 479#ifdef KERBEROS 480 if (use_kerberos) { 481 if (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0') { 482 if (kuserok(kdata, locuser) != 0) { 483 syslog(LOG_INFO|LOG_AUTH, 484 "Kerberos rsh denied to %s.%s@%s", 485 kdata->pname, kdata->pinst, kdata->prealm); 486 error("Login incorrect.\n"); 487 exit(1); 488 } 489 } 490 } else 491#endif 492 493 if (errorstr || 494 (pwd->pw_expire && time(NULL) >= pwd->pw_expire) || 495 (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' && 496 iruserok(fromp->sin_addr.s_addr, pwd->pw_uid == 0, 497 remuser, locuser) < 0)) { 498 if (__rcmd_errstr) 499 syslog(LOG_INFO|LOG_AUTH, 500 "%s@%s as %s: permission denied (%s). cmd='%.80s'", 501 remuser, hostname, locuser, __rcmd_errstr, 502 cmdbuf); 503 else 504 syslog(LOG_INFO|LOG_AUTH, 505 "%s@%s as %s: permission denied. cmd='%.80s'", 506 remuser, hostname, locuser, cmdbuf); 507fail: 508 if (errorstr == NULL) 509 errorstr = "Login incorrect.\n"; 510 error(errorstr, errorhost); 511 exit(1); 512 } 513 514 if (pwd->pw_uid && !access(_PATH_NOLOGIN, F_OK)) { 515 error("Logins currently disabled.\n"); 516 exit(1); 517 } 518#ifdef LOGIN_CAP 519 if (lc != NULL) { 520 char remote_ip[MAXHOSTNAMELEN]; 521 522 strncpy(remote_ip, inet_ntoa(fromp->sin_addr), 523 sizeof(remote_ip) - 1); 524 remote_ip[sizeof(remote_ip) - 1] = 0; 525 if (!auth_hostok(lc, fromhost, remote_ip)) { 526 syslog(LOG_INFO|LOG_AUTH, 527 "%s@%s as %s: permission denied (%s). cmd='%.80s'", 528 remuser, hostname, locuser, __rcmd_errstr, 529 cmdbuf); 530 error("Login incorrect.\n"); 531 exit(1); 532 } 533 if (!auth_timeok(lc, time(NULL))) { 534 error("Logins not available right now\n"); 535 exit(1); 536 } 537 } 538#endif /* !LOGIN_CAP */ 539#if BSD > 43 540 /* before fork, while we're session leader */ 541 if (setlogin(pwd->pw_name) < 0) 542 syslog(LOG_ERR, "setlogin() failed: %m"); 543#endif 544 545 (void) write(STDERR_FILENO, "\0", 1); 546 sent_null = 1; 547 548 if (port) { 549 if (pipe(pv) < 0) { 550 error("Can't make pipe.\n"); 551 exit(1); 552 } 553#ifdef CRYPT 554#ifdef KERBEROS 555 if (doencrypt) { 556 if (pipe(pv1) < 0) { 557 error("Can't make 2nd pipe.\n"); 558 exit(1); 559 } 560 if (pipe(pv2) < 0) { 561 error("Can't make 3rd pipe.\n"); 562 exit(1); 563 } 564 } 565#endif 566#endif 567 pid = fork(); 568 if (pid == -1) { 569 error("Can't fork; try again.\n"); 570 exit(1); 571 } 572 if (pid) { 573#ifdef CRYPT 574#ifdef KERBEROS 575 if (doencrypt) { 576 static char msg[] = SECURE_MESSAGE; 577 (void) close(pv1[1]); 578 (void) close(pv2[1]); 579 des_enc_write(s, msg, sizeof(msg) - 1, 580 schedule, &kdata->session); 581 582 } else 583#endif 584#endif 585 { 586 (void) close(0); 587 (void) close(1); 588 } 589 (void) close(2); 590 (void) close(pv[1]); 591 592 FD_ZERO(&readfrom); 593 FD_SET(s, &readfrom); 594 FD_SET(pv[0], &readfrom); 595 if (pv[0] > s) 596 nfd = pv[0]; 597 else 598 nfd = s; 599#ifdef CRYPT 600#ifdef KERBEROS 601 if (doencrypt) { 602 FD_ZERO(&writeto); 603 FD_SET(pv2[0], &writeto); 604 FD_SET(pv1[0], &readfrom); 605 606 nfd = MAX(nfd, pv2[0]); 607 nfd = MAX(nfd, pv1[0]); 608 } else 609#endif 610#endif 611 ioctl(pv[0], FIONBIO, (char *)&one); 612 613 /* should set s nbio! */ 614 nfd++; 615 do { 616 ready = readfrom; 617#ifdef CRYPT 618#ifdef KERBEROS 619 if (doencrypt) { 620 wready = writeto; 621 if (select(nfd, &ready, 622 &wready, (fd_set *) 0, 623 (struct timeval *) 0) < 0) 624 break; 625 } else 626#endif 627#endif 628 if (select(nfd, &ready, (fd_set *)0, 629 (fd_set *)0, (struct timeval *)0) < 0) 630 break; 631 if (FD_ISSET(s, &ready)) { 632 int ret; 633#ifdef CRYPT 634#ifdef KERBEROS 635 if (doencrypt) 636 ret = des_enc_read(s, &sig, 1, 637 schedule, &kdata->session); 638 else 639#endif 640#endif 641 ret = read(s, &sig, 1); 642 if (ret <= 0) 643 FD_CLR(s, &readfrom); 644 else 645 killpg(pid, sig); 646 } 647 if (FD_ISSET(pv[0], &ready)) { 648 errno = 0; 649 cc = read(pv[0], buf, sizeof(buf)); 650 if (cc <= 0) { 651 shutdown(s, 1+1); 652 FD_CLR(pv[0], &readfrom); 653 } else { 654#ifdef CRYPT 655#ifdef KERBEROS 656 if (doencrypt) 657 (void) 658 des_enc_write(s, buf, cc, 659 schedule, &kdata->session); 660 else 661#endif 662#endif 663 (void) 664 write(s, buf, cc); 665 } 666 } 667#ifdef CRYPT 668#ifdef KERBEROS 669 if (doencrypt && FD_ISSET(pv1[0], &ready)) { 670 errno = 0; 671 cc = read(pv1[0], buf, sizeof(buf)); 672 if (cc <= 0) { 673 shutdown(pv1[0], 1+1); 674 FD_CLR(pv1[0], &readfrom); 675 } else 676 (void) des_enc_write(STDOUT_FILENO, 677 buf, cc, 678 schedule, &kdata->session); 679 } 680 681 if (doencrypt && FD_ISSET(pv2[0], &wready)) { 682 errno = 0; 683 cc = des_enc_read(STDIN_FILENO, 684 buf, sizeof(buf), 685 schedule, &kdata->session); 686 if (cc <= 0) { 687 shutdown(pv2[0], 1+1); 688 FD_CLR(pv2[0], &writeto); 689 } else 690 (void) write(pv2[0], buf, cc); 691 } 692#endif 693#endif 694 695 } while (FD_ISSET(s, &readfrom) || 696#ifdef CRYPT 697#ifdef KERBEROS 698 (doencrypt && FD_ISSET(pv1[0], &readfrom)) || 699#endif 700#endif 701 FD_ISSET(pv[0], &readfrom)); 702 exit(0); 703 } 704 setpgrp(0, getpid()); 705 (void) close(s); 706 (void) close(pv[0]); 707#ifdef CRYPT 708#ifdef KERBEROS 709 if (doencrypt) { 710 close(pv1[0]); close(pv2[0]); 711 dup2(pv1[1], 1); 712 dup2(pv2[1], 0); 713 close(pv1[1]); 714 close(pv2[1]); 715 } 716#endif 717#endif 718 dup2(pv[1], 2); 719 close(pv[1]); 720 } 721 if (*pwd->pw_shell == '\0') 722 pwd->pw_shell = _PATH_BSHELL; 723 environ = envinit; 724 strncat(homedir, pwd->pw_dir, sizeof(homedir)-6); 725 strcat(path, _PATH_DEFPATH); 726 strncat(shell, pwd->pw_shell, sizeof(shell)-7); 727 strncat(username, pwd->pw_name, sizeof(username)-6); 728 cp = strrchr(pwd->pw_shell, '/'); 729 if (cp) 730 cp++; 731 else 732 cp = pwd->pw_shell; 733#ifdef LOGIN_CAP 734 if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETALL) != 0) { 735 syslog(LOG_ERR, "setusercontext: %m"); 736 exit(1); 737 } 738 login_close(lc); 739#else 740 (void) setgid((gid_t)pwd->pw_gid); 741 initgroups(pwd->pw_name, pwd->pw_gid); 742 (void) setuid((uid_t)pwd->pw_uid); 743#endif 744 endpwent(); 745 if (log_success || pwd->pw_uid == 0) { 746#ifdef KERBEROS 747 if (use_kerberos) 748 syslog(LOG_INFO|LOG_AUTH, 749 "Kerberos shell from %s.%s@%s on %s as %s, cmd='%.80s'", 750 kdata->pname, kdata->pinst, kdata->prealm, 751 hostname, locuser, cmdbuf); 752 else 753#endif 754 syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'", 755 remuser, hostname, locuser, cmdbuf); 756 } 757 execl(pwd->pw_shell, cp, "-c", cmdbuf, 0); 758 perror(pwd->pw_shell); 759 exit(1); 760} 761 762/* 763 * Report error to client. Note: can't be used until second socket has 764 * connected to client, or older clients will hang waiting for that 765 * connection first. 766 */ 767#if __STDC__ 768#include <stdarg.h> 769#else 770#include <varargs.h> 771#endif 772 773void 774#if __STDC__ 775error(const char *fmt, ...) 776#else 777error(fmt, va_alist) 778 char *fmt; 779 va_dcl 780#endif 781{ 782 va_list ap; 783 int len; 784 char *bp, buf[BUFSIZ]; 785#if __STDC__ 786 va_start(ap, fmt); 787#else 788 va_start(ap); 789#endif 790 bp = buf; 791 if (sent_null == 0) { 792 *bp++ = 1; 793 len = 1; 794 } else 795 len = 0; 796 (void)vsnprintf(bp, sizeof(buf) - 1, fmt, ap); 797 (void)write(STDERR_FILENO, buf, len + strlen(bp)); 798} 799 800void 801getstr(buf, cnt, err) 802 char *buf, *err; 803 int cnt; 804{ 805 char c; 806 807 do { 808 if (read(STDIN_FILENO, &c, 1) != 1) 809 exit(1); 810 *buf++ = c; 811 if (--cnt == 0) { 812 error("%s too long\n", err); 813 exit(1); 814 } 815 } while (c != 0); 816} 817 818/* 819 * Check whether host h is in our local domain, 820 * defined as sharing the last two components of the domain part, 821 * or the entire domain part if the local domain has only one component. 822 * If either name is unqualified (contains no '.'), 823 * assume that the host is local, as it will be 824 * interpreted as such. 825 */ 826int 827local_domain(h) 828 char *h; 829{ 830 char localhost[MAXHOSTNAMELEN]; 831 char *p1, *p2; 832 833 localhost[0] = 0; 834 (void) gethostname(localhost, sizeof(localhost)); 835 p1 = topdomain(localhost); 836 p2 = topdomain(h); 837 if (p1 == NULL || p2 == NULL || !strcasecmp(p1, p2)) 838 return (1); 839 return (0); 840} 841 842char * 843topdomain(h) 844 char *h; 845{ 846 char *p, *maybe = NULL; 847 int dots = 0; 848 849 for (p = h + strlen(h); p >= h; p--) { 850 if (*p == '.') { 851 if (++dots == 2) 852 return (p); 853 maybe = p; 854 } 855 } 856 return (maybe); 857} 858 859void 860usage() 861{ 862 863 syslog(LOG_ERR, "usage: rshd [-%s]", OPTIONS); 864 exit(2); 865} 866