rshd.c revision 29917
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 1.18 1997/07/18 21:04:19 wosch Exp $ 34 */ 35 36#ifndef lint 37static const 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 const 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_systm.h> 60#include <netinet/in.h> 61#include <netinet/ip.h> 62#include <arpa/inet.h> 63#include <netdb.h> 64 65#include <errno.h> 66#include <fcntl.h> 67#include <paths.h> 68#include <pwd.h> 69#include <signal.h> 70#include <stdio.h> 71#include <stdlib.h> 72#include <string.h> 73#include <syslog.h> 74#include <unistd.h> 75#ifdef LOGIN_CAP 76#include <login_cap.h> 77#endif 78 79int keepalive = 1; 80int check_all; 81int log_success; /* If TRUE, log all successful accesses */ 82int sent_null; 83 84void doit __P((struct sockaddr_in *)); 85void error __P((const char *, ...)); 86void getstr __P((char *, int, char *)); 87int local_domain __P((char *)); 88char *topdomain __P((char *)); 89void usage __P((void)); 90 91#ifdef KERBEROS 92#include <des.h> 93#include <krb.h> 94#define VERSION_SIZE 9 95#define SECURE_MESSAGE "This rsh session is using DES encryption for all transmissions.\r\n" 96#define OPTIONS "alnkvxL" 97char authbuf[sizeof(AUTH_DAT)]; 98char tickbuf[sizeof(KTEXT_ST)]; 99int doencrypt, use_kerberos, vacuous; 100Key_schedule schedule; 101#else 102#define OPTIONS "alnL" 103#endif 104 105int 106main(argc, argv) 107 int argc; 108 char *argv[]; 109{ 110 extern int __check_rhosts_file; 111 struct linger linger; 112 int ch, on = 1, fromlen; 113 struct sockaddr_in from; 114 115 openlog("rshd", LOG_PID | LOG_ODELAY, LOG_DAEMON); 116 117 opterr = 0; 118 while ((ch = getopt(argc, argv, OPTIONS)) != -1) 119 switch (ch) { 120 case 'a': 121 check_all = 1; 122 break; 123 case 'l': 124 __check_rhosts_file = 0; 125 break; 126 case 'n': 127 keepalive = 0; 128 break; 129#ifdef KERBEROS 130 case 'k': 131 use_kerberos = 1; 132 break; 133 134 case 'v': 135 vacuous = 1; 136 break; 137 138#ifdef CRYPT 139 case 'x': 140 doencrypt = 1; 141 break; 142#endif 143#endif 144 case 'L': 145 log_success = 1; 146 break; 147 case '?': 148 default: 149 usage(); 150 break; 151 } 152 153 argc -= optind; 154 argv += optind; 155 156#ifdef KERBEROS 157 if (use_kerberos && vacuous) { 158 syslog(LOG_ERR, "only one of -k and -v allowed"); 159 exit(2); 160 } 161#ifdef CRYPT 162 if (doencrypt && !use_kerberos) { 163 syslog(LOG_ERR, "-k is required for -x"); 164 exit(2); 165 } 166#endif 167#endif 168 169 fromlen = sizeof (from); 170 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) { 171 syslog(LOG_ERR, "getpeername: %m"); 172 _exit(1); 173 } 174 if (keepalive && 175 setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, (char *)&on, 176 sizeof(on)) < 0) 177 syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m"); 178 linger.l_onoff = 1; 179 linger.l_linger = 60; /* XXX */ 180 if (setsockopt(0, SOL_SOCKET, SO_LINGER, (char *)&linger, 181 sizeof (linger)) < 0) 182 syslog(LOG_WARNING, "setsockopt (SO_LINGER): %m"); 183 doit(&from); 184 /* NOTREACHED */ 185 return(0); 186} 187 188char username[20] = "USER="; 189char homedir[64] = "HOME="; 190char shell[64] = "SHELL="; 191char path[100] = "PATH="; 192char *envinit[] = 193 {homedir, shell, path, username, 0}; 194char **environ; 195 196void 197doit(fromp) 198 struct sockaddr_in *fromp; 199{ 200 extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */ 201 struct hostent *hp; 202 struct passwd *pwd; 203 u_short port; 204 fd_set ready, readfrom; 205 int cc, nfd, pv[2], pid, s; 206 int one = 1; 207 char *hostname, *errorstr, *errorhost; 208 char *cp, sig, buf[BUFSIZ]; 209 char cmdbuf[NCARGS+1], locuser[16], remuser[16]; 210 char remotehost[2 * MAXHOSTNAMELEN + 1]; 211 char fromhost[2 * MAXHOSTNAMELEN + 1]; 212#ifdef LOGIN_CAP 213 login_cap_t *lc; 214#endif 215 216#ifdef KERBEROS 217 AUTH_DAT *kdata = (AUTH_DAT *) NULL; 218 KTEXT ticket = (KTEXT) NULL; 219 char instance[INST_SZ], version[VERSION_SIZE]; 220 struct sockaddr_in fromaddr; 221 int rc; 222 long authopts; 223 int pv1[2], pv2[2]; 224 fd_set wready, writeto; 225 226 fromaddr = *fromp; 227#endif 228 229 (void) signal(SIGINT, SIG_DFL); 230 (void) signal(SIGQUIT, SIG_DFL); 231 (void) signal(SIGTERM, SIG_DFL); 232#ifdef DEBUG 233 { int t = open(_PATH_TTY, 2); 234 if (t >= 0) { 235 ioctl(t, TIOCNOTTY, (char *)0); 236 (void) close(t); 237 } 238 } 239#endif 240 fromp->sin_port = ntohs((u_short)fromp->sin_port); 241 if (fromp->sin_family != AF_INET) { 242 syslog(LOG_ERR, "malformed \"from\" address (af %d)\n", 243 fromp->sin_family); 244 exit(1); 245 } 246#ifdef IP_OPTIONS 247 { 248 u_char optbuf[BUFSIZ/3]; 249 int optsize = sizeof(optbuf), ipproto, i; 250 struct protoent *ip; 251 252 if ((ip = getprotobyname("ip")) != NULL) 253 ipproto = ip->p_proto; 254 else 255 ipproto = IPPROTO_IP; 256 if (!getsockopt(0, ipproto, IP_OPTIONS, (char *)optbuf, &optsize) && 257 optsize != 0) { 258 for (i = 0; i < optsize; ) { 259 u_char c = optbuf[i]; 260 if (c == IPOPT_LSRR || c == IPOPT_SSRR) { 261 syslog(LOG_NOTICE, 262 "Connection refused from %s with IP option %s", 263 inet_ntoa(fromp->sin_addr), 264 c == IPOPT_LSRR ? "LSRR" : "SSRR"); 265 exit(1); 266 } 267 if (c == IPOPT_EOL) 268 break; 269 i += (c == IPOPT_NOP) ? 1 : optbuf[i+1]; 270 } 271 } 272 } 273#endif 274 275#ifdef KERBEROS 276 if (!use_kerberos) 277#endif 278 if (fromp->sin_port >= IPPORT_RESERVED || 279 fromp->sin_port < IPPORT_RESERVED/2) { 280 syslog(LOG_NOTICE|LOG_AUTH, 281 "Connection from %s on illegal port %u", 282 inet_ntoa(fromp->sin_addr), 283 fromp->sin_port); 284 exit(1); 285 } 286 287 (void) alarm(60); 288 port = 0; 289 for (;;) { 290 char c; 291 if ((cc = read(STDIN_FILENO, &c, 1)) != 1) { 292 if (cc < 0) 293 syslog(LOG_NOTICE, "read: %m"); 294 shutdown(0, 1+1); 295 exit(1); 296 } 297 if (c== 0) 298 break; 299 port = port * 10 + c - '0'; 300 } 301 302 (void) alarm(0); 303 if (port != 0) { 304 int lport = IPPORT_RESERVED - 1; 305 s = rresvport(&lport); 306 if (s < 0) { 307 syslog(LOG_ERR, "can't get stderr port: %m"); 308 exit(1); 309 } 310#ifdef KERBEROS 311 if (!use_kerberos) 312#endif 313 if (port >= IPPORT_RESERVED || 314 port < IPPORT_RESERVED/2) { 315 syslog(LOG_NOTICE|LOG_AUTH, 316 "2nd socket from %s on unreserved port %u", 317 inet_ntoa(fromp->sin_addr), 318 port); 319 exit(1); 320 } 321 fromp->sin_port = htons(port); 322 if (connect(s, (struct sockaddr *)fromp, sizeof (*fromp)) < 0) { 323 syslog(LOG_INFO, "connect second port %d: %m", port); 324 exit(1); 325 } 326 } 327 328#ifdef KERBEROS 329 if (vacuous) { 330 error("rshd: remote host requires Kerberos authentication\n"); 331 exit(1); 332 } 333#endif 334 335#ifdef notdef 336 /* from inetd, socket is already on 0, 1, 2 */ 337 dup2(f, 0); 338 dup2(f, 1); 339 dup2(f, 2); 340#endif 341 errorstr = NULL; 342 hp = gethostbyaddr((char *)&fromp->sin_addr, sizeof (struct in_addr), 343 fromp->sin_family); 344 if (hp) { 345 /* 346 * If name returned by gethostbyaddr is in our domain, 347 * attempt to verify that we haven't been fooled by someone 348 * in a remote net; look up the name and check that this 349 * address corresponds to the name. 350 */ 351 strncpy(fromhost, hp->h_name, sizeof(fromhost) - 1); 352 fromhost[sizeof(fromhost) - 1] = 0; 353 hostname = fromhost; 354#ifdef KERBEROS 355 if (!use_kerberos) 356#endif 357 if (check_all || local_domain(hp->h_name)) { 358 strncpy(remotehost, hp->h_name, sizeof(remotehost) - 1); 359 remotehost[sizeof(remotehost) - 1] = 0; 360 errorhost = remotehost; 361 hp = gethostbyname(remotehost); 362 if (hp == NULL) { 363 syslog(LOG_INFO, 364 "Couldn't look up address for %s", 365 remotehost); 366 errorstr = 367 "Couldn't look up address for your host (%s)\n"; 368 strncpy(fromhost, inet_ntoa(fromp->sin_addr), 369 sizeof(fromhost) - 1); 370 fromhost[sizeof(fromhost) - 1] = 0; 371 hostname = fromhost; 372 } else for (; ; hp->h_addr_list++) { 373 if (hp->h_addr_list[0] == NULL) { 374 syslog(LOG_NOTICE, 375 "Host addr %s not listed for host %s", 376 inet_ntoa(fromp->sin_addr), 377 hp->h_name); 378 errorstr = 379 "Host address mismatch for %s\n"; 380 strncpy(fromhost, inet_ntoa(fromp->sin_addr), 381 sizeof(fromhost) - 1); 382 fromhost[sizeof(fromhost) - 1] = 0; 383 hostname = fromhost; 384 break; 385 } 386 if (!bcmp(hp->h_addr_list[0], 387 (caddr_t)&fromp->sin_addr, 388 sizeof(fromp->sin_addr))) { 389 hostname = remotehost; 390 break; 391 } 392 } 393 } 394 } else { 395 strncpy(fromhost, inet_ntoa(fromp->sin_addr), 396 sizeof(fromhost) - 1); 397 fromhost[sizeof(fromhost) - 1] = 0; 398 errorhost = hostname = fromhost; 399 } 400 401#ifdef KERBEROS 402 if (use_kerberos) { 403 kdata = (AUTH_DAT *) authbuf; 404 ticket = (KTEXT) tickbuf; 405 authopts = 0L; 406 strcpy(instance, "*"); 407 version[VERSION_SIZE - 1] = '\0'; 408#ifdef CRYPT 409 if (doencrypt) { 410 struct sockaddr_in local_addr; 411 rc = sizeof(local_addr); 412 if (getsockname(0, (struct sockaddr *)&local_addr, 413 &rc) < 0) { 414 syslog(LOG_ERR, "getsockname: %m"); 415 error("rlogind: getsockname: %m"); 416 exit(1); 417 } 418 authopts = KOPT_DO_MUTUAL; 419 rc = krb_recvauth(authopts, 0, ticket, 420 "rcmd", instance, &fromaddr, 421 &local_addr, kdata, "", schedule, 422 version); 423 des_set_key(&kdata->session, schedule); 424 } else 425#endif 426 rc = krb_recvauth(authopts, 0, ticket, "rcmd", 427 instance, &fromaddr, 428 (struct sockaddr_in *) 0, 429 kdata, "", NULL, version); 430 if (rc != KSUCCESS) { 431 error("Kerberos authentication failure: %s\n", 432 krb_err_txt[rc]); 433 exit(1); 434 } 435 } else 436#endif 437 getstr(remuser, sizeof(remuser), "remuser"); 438 439 getstr(locuser, sizeof(locuser), "locuser"); 440 getstr(cmdbuf, sizeof(cmdbuf), "command"); 441 setpwent(); 442 pwd = getpwnam(locuser); 443 if (pwd == NULL) { 444 syslog(LOG_INFO|LOG_AUTH, 445 "%s@%s as %s: unknown login. cmd='%.80s'", 446 remuser, hostname, locuser, cmdbuf); 447 if (errorstr == NULL) 448 errorstr = "Login incorrect.\n"; 449 goto fail; 450 } 451#ifdef LOGIN_CAP 452 lc = login_getpwclass(pwd); 453#endif 454 if (chdir(pwd->pw_dir) < 0) { 455#ifdef LOGIN_CAP 456 if (chdir("/") < 0 || 457 login_getcapbool(lc, "requirehome", !!pwd->pw_uid)) { 458 syslog(LOG_INFO|LOG_AUTH, 459 "%s@%s as %s: no home directory. cmd='%.80s'", 460 remuser, hostname, locuser, cmdbuf); 461 error("No remote home directory.\n"); 462 exit(0); 463 } 464#else 465 (void) chdir("/"); 466#ifdef notdef 467 syslog(LOG_INFO|LOG_AUTH, 468 "%s@%s as %s: no home directory. cmd='%.80s'", 469 remuser, hostname, locuser, cmdbuf); 470 error("No remote directory.\n"); 471 exit(1); 472#endif 473#endif 474 pwd->pw_dir = "/"; 475 } 476 477#ifdef KERBEROS 478 if (use_kerberos) { 479 if (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0') { 480 if (kuserok(kdata, locuser) != 0) { 481 syslog(LOG_INFO|LOG_AUTH, 482 "Kerberos rsh denied to %s.%s@%s", 483 kdata->pname, kdata->pinst, kdata->prealm); 484 error("Login incorrect.\n"); 485 exit(1); 486 } 487 } 488 } else 489#endif 490 491 if (errorstr || 492 (pwd->pw_expire && time(NULL) >= pwd->pw_expire) || 493 (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' && 494 iruserok(fromp->sin_addr.s_addr, pwd->pw_uid == 0, 495 remuser, locuser) < 0)) { 496 if (__rcmd_errstr) 497 syslog(LOG_INFO|LOG_AUTH, 498 "%s@%s as %s: permission denied (%s). cmd='%.80s'", 499 remuser, hostname, locuser, __rcmd_errstr, 500 cmdbuf); 501 else 502 syslog(LOG_INFO|LOG_AUTH, 503 "%s@%s as %s: permission denied. cmd='%.80s'", 504 remuser, hostname, locuser, cmdbuf); 505fail: 506 if (errorstr == NULL) 507 errorstr = "Login incorrect.\n"; 508 error(errorstr, errorhost); 509 exit(1); 510 } 511 512 if (pwd->pw_uid && !access(_PATH_NOLOGIN, F_OK)) { 513 error("Logins currently disabled.\n"); 514 exit(1); 515 } 516#ifdef LOGIN_CAP 517 if (lc != NULL) { 518 char remote_ip[MAXHOSTNAMELEN]; 519 520 strncpy(remote_ip, inet_ntoa(fromp->sin_addr), 521 sizeof(remote_ip) - 1); 522 remote_ip[sizeof(remote_ip) - 1] = 0; 523 if (!auth_hostok(lc, fromhost, remote_ip)) { 524 syslog(LOG_INFO|LOG_AUTH, 525 "%s@%s as %s: permission denied (%s). cmd='%.80s'", 526 remuser, hostname, locuser, __rcmd_errstr, 527 cmdbuf); 528 error("Login incorrect.\n"); 529 exit(1); 530 } 531 if (!auth_timeok(lc, time(NULL))) { 532 error("Logins not available right now\n"); 533 exit(1); 534 } 535 } 536#endif /* !LOGIN_CAP */ 537#if BSD > 43 538 /* before fork, while we're session leader */ 539 if (setlogin(pwd->pw_name) < 0) 540 syslog(LOG_ERR, "setlogin() failed: %m"); 541#endif 542 543 (void) write(STDERR_FILENO, "\0", 1); 544 sent_null = 1; 545 546 if (port) { 547 if (pipe(pv) < 0) { 548 error("Can't make pipe.\n"); 549 exit(1); 550 } 551#ifdef CRYPT 552#ifdef KERBEROS 553 if (doencrypt) { 554 if (pipe(pv1) < 0) { 555 error("Can't make 2nd pipe.\n"); 556 exit(1); 557 } 558 if (pipe(pv2) < 0) { 559 error("Can't make 3rd pipe.\n"); 560 exit(1); 561 } 562 } 563#endif 564#endif 565 pid = fork(); 566 if (pid == -1) { 567 error("Can't fork; try again.\n"); 568 exit(1); 569 } 570 if (pid) { 571#ifdef CRYPT 572#ifdef KERBEROS 573 if (doencrypt) { 574 static char msg[] = SECURE_MESSAGE; 575 (void) close(pv1[1]); 576 (void) close(pv2[1]); 577 des_enc_write(s, msg, sizeof(msg) - 1, 578 schedule, &kdata->session); 579 580 } else 581#endif 582#endif 583 { 584 (void) close(0); 585 (void) close(1); 586 } 587 (void) close(2); 588 (void) close(pv[1]); 589 590 FD_ZERO(&readfrom); 591 FD_SET(s, &readfrom); 592 FD_SET(pv[0], &readfrom); 593 if (pv[0] > s) 594 nfd = pv[0]; 595 else 596 nfd = s; 597#ifdef CRYPT 598#ifdef KERBEROS 599 if (doencrypt) { 600 FD_ZERO(&writeto); 601 FD_SET(pv2[0], &writeto); 602 FD_SET(pv1[0], &readfrom); 603 604 nfd = MAX(nfd, pv2[0]); 605 nfd = MAX(nfd, pv1[0]); 606 } else 607#endif 608#endif 609 ioctl(pv[0], FIONBIO, (char *)&one); 610 611 /* should set s nbio! */ 612 nfd++; 613 do { 614 ready = readfrom; 615#ifdef CRYPT 616#ifdef KERBEROS 617 if (doencrypt) { 618 wready = writeto; 619 if (select(nfd, &ready, 620 &wready, (fd_set *) 0, 621 (struct timeval *) 0) < 0) 622 break; 623 } else 624#endif 625#endif 626 if (select(nfd, &ready, (fd_set *)0, 627 (fd_set *)0, (struct timeval *)0) < 0) 628 break; 629 if (FD_ISSET(s, &ready)) { 630 int ret; 631#ifdef CRYPT 632#ifdef KERBEROS 633 if (doencrypt) 634 ret = des_enc_read(s, &sig, 1, 635 schedule, &kdata->session); 636 else 637#endif 638#endif 639 ret = read(s, &sig, 1); 640 if (ret <= 0) 641 FD_CLR(s, &readfrom); 642 else 643 killpg(pid, sig); 644 } 645 if (FD_ISSET(pv[0], &ready)) { 646 errno = 0; 647 cc = read(pv[0], buf, sizeof(buf)); 648 if (cc <= 0) { 649 shutdown(s, 1+1); 650 FD_CLR(pv[0], &readfrom); 651 } else { 652#ifdef CRYPT 653#ifdef KERBEROS 654 if (doencrypt) 655 (void) 656 des_enc_write(s, buf, cc, 657 schedule, &kdata->session); 658 else 659#endif 660#endif 661 (void) 662 write(s, buf, cc); 663 } 664 } 665#ifdef CRYPT 666#ifdef KERBEROS 667 if (doencrypt && FD_ISSET(pv1[0], &ready)) { 668 errno = 0; 669 cc = read(pv1[0], buf, sizeof(buf)); 670 if (cc <= 0) { 671 shutdown(pv1[0], 1+1); 672 FD_CLR(pv1[0], &readfrom); 673 } else 674 (void) des_enc_write(STDOUT_FILENO, 675 buf, cc, 676 schedule, &kdata->session); 677 } 678 679 if (doencrypt && FD_ISSET(pv2[0], &wready)) { 680 errno = 0; 681 cc = des_enc_read(STDIN_FILENO, 682 buf, sizeof(buf), 683 schedule, &kdata->session); 684 if (cc <= 0) { 685 shutdown(pv2[0], 1+1); 686 FD_CLR(pv2[0], &writeto); 687 } else 688 (void) write(pv2[0], buf, cc); 689 } 690#endif 691#endif 692 693 } while (FD_ISSET(s, &readfrom) || 694#ifdef CRYPT 695#ifdef KERBEROS 696 (doencrypt && FD_ISSET(pv1[0], &readfrom)) || 697#endif 698#endif 699 FD_ISSET(pv[0], &readfrom)); 700 exit(0); 701 } 702 setpgrp(0, getpid()); 703 (void) close(s); 704 (void) close(pv[0]); 705#ifdef CRYPT 706#ifdef KERBEROS 707 if (doencrypt) { 708 close(pv1[0]); close(pv2[0]); 709 dup2(pv1[1], 1); 710 dup2(pv2[1], 0); 711 close(pv1[1]); 712 close(pv2[1]); 713 } 714#endif 715#endif 716 dup2(pv[1], 2); 717 close(pv[1]); 718 } 719 if (*pwd->pw_shell == '\0') 720 pwd->pw_shell = _PATH_BSHELL; 721 environ = envinit; 722 strncat(homedir, pwd->pw_dir, sizeof(homedir)-6); 723 strcat(path, _PATH_DEFPATH); 724 strncat(shell, pwd->pw_shell, sizeof(shell)-7); 725 strncat(username, pwd->pw_name, sizeof(username)-6); 726 cp = strrchr(pwd->pw_shell, '/'); 727 if (cp) 728 cp++; 729 else 730 cp = pwd->pw_shell; 731#ifdef LOGIN_CAP 732 if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETALL) != 0) { 733 syslog(LOG_ERR, "setusercontext: %m"); 734 exit(1); 735 } 736 login_close(lc); 737#else 738 (void) setgid((gid_t)pwd->pw_gid); 739 initgroups(pwd->pw_name, pwd->pw_gid); 740 (void) setuid((uid_t)pwd->pw_uid); 741#endif 742 endpwent(); 743 if (log_success || pwd->pw_uid == 0) { 744#ifdef KERBEROS 745 if (use_kerberos) 746 syslog(LOG_INFO|LOG_AUTH, 747 "Kerberos shell from %s.%s@%s on %s as %s, cmd='%.80s'", 748 kdata->pname, kdata->pinst, kdata->prealm, 749 hostname, locuser, cmdbuf); 750 else 751#endif 752 syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'", 753 remuser, hostname, locuser, cmdbuf); 754 } 755 execl(pwd->pw_shell, cp, "-c", cmdbuf, 0); 756 perror(pwd->pw_shell); 757 exit(1); 758} 759 760/* 761 * Report error to client. Note: can't be used until second socket has 762 * connected to client, or older clients will hang waiting for that 763 * connection first. 764 */ 765#if __STDC__ 766#include <stdarg.h> 767#else 768#include <varargs.h> 769#endif 770 771void 772#if __STDC__ 773error(const char *fmt, ...) 774#else 775error(fmt, va_alist) 776 char *fmt; 777 va_dcl 778#endif 779{ 780 va_list ap; 781 int len; 782 char *bp, buf[BUFSIZ]; 783#if __STDC__ 784 va_start(ap, fmt); 785#else 786 va_start(ap); 787#endif 788 bp = buf; 789 if (sent_null == 0) { 790 *bp++ = 1; 791 len = 1; 792 } else 793 len = 0; 794 (void)vsnprintf(bp, sizeof(buf) - 1, fmt, ap); 795 (void)write(STDERR_FILENO, buf, len + strlen(bp)); 796} 797 798void 799getstr(buf, cnt, err) 800 char *buf, *err; 801 int cnt; 802{ 803 char c; 804 805 do { 806 if (read(STDIN_FILENO, &c, 1) != 1) 807 exit(1); 808 *buf++ = c; 809 if (--cnt == 0) { 810 error("%s too long\n", err); 811 exit(1); 812 } 813 } while (c != 0); 814} 815 816/* 817 * Check whether host h is in our local domain, 818 * defined as sharing the last two components of the domain part, 819 * or the entire domain part if the local domain has only one component. 820 * If either name is unqualified (contains no '.'), 821 * assume that the host is local, as it will be 822 * interpreted as such. 823 */ 824int 825local_domain(h) 826 char *h; 827{ 828 char localhost[MAXHOSTNAMELEN]; 829 char *p1, *p2; 830 831 localhost[0] = 0; 832 (void) gethostname(localhost, sizeof(localhost)); 833 p1 = topdomain(localhost); 834 p2 = topdomain(h); 835 if (p1 == NULL || p2 == NULL || !strcasecmp(p1, p2)) 836 return (1); 837 return (0); 838} 839 840char * 841topdomain(h) 842 char *h; 843{ 844 char *p, *maybe = NULL; 845 int dots = 0; 846 847 for (p = h + strlen(h); p >= h; p--) { 848 if (*p == '.') { 849 if (++dots == 2) 850 return (p); 851 maybe = p; 852 } 853 } 854 return (maybe); 855} 856 857void 858usage() 859{ 860 861 syslog(LOG_ERR, "usage: rshd [-%s]", OPTIONS); 862 exit(2); 863} 864