rshd.c revision 41860
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 1.22 1998/12/01 23:27:24 dg 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 <netinet/tcp.h> 65#include <arpa/inet.h> 66#include <netdb.h> 67 68#include <errno.h> 69#include <fcntl.h> 70#include <paths.h> 71#include <pwd.h> 72#include <signal.h> 73#include <stdio.h> 74#include <stdlib.h> 75#include <string.h> 76#include <syslog.h> 77#include <unistd.h> 78#ifdef LOGIN_CAP 79#include <login_cap.h> 80#endif 81 82int keepalive = 1; 83int log_success; /* If TRUE, log all successful accesses */ 84int sent_null; 85int no_delay; 86 87void doit __P((struct sockaddr_in *)); 88void error __P((const char *, ...)); 89void getstr __P((char *, int, char *)); 90int local_domain __P((char *)); 91char *topdomain __P((char *)); 92void usage __P((void)); 93 94#ifdef KERBEROS 95#include <des.h> 96#include <krb.h> 97#define VERSION_SIZE 9 98#define SECURE_MESSAGE "This rsh session is using DES encryption for all transmissions.\r\n" 99#define OPTIONS "alnkvxDL" 100char authbuf[sizeof(AUTH_DAT)]; 101char tickbuf[sizeof(KTEXT_ST)]; 102int doencrypt, use_kerberos, vacuous; 103Key_schedule schedule; 104#else 105#define OPTIONS "alnDL" 106#endif 107 108int 109main(argc, argv) 110 int argc; 111 char *argv[]; 112{ 113 extern int __check_rhosts_file; 114 struct linger linger; 115 int ch, on = 1, fromlen; 116 struct sockaddr_in from; 117 118 openlog("rshd", LOG_PID | LOG_ODELAY, LOG_DAEMON); 119 120 opterr = 0; 121 while ((ch = getopt(argc, argv, OPTIONS)) != -1) 122 switch (ch) { 123 case 'a': 124 /* ignored for compatability */ 125 break; 126 case 'l': 127 __check_rhosts_file = 0; 128 break; 129 case 'n': 130 keepalive = 0; 131 break; 132#ifdef KERBEROS 133 case 'k': 134 use_kerberos = 1; 135 break; 136 137 case 'v': 138 vacuous = 1; 139 break; 140 141#ifdef CRYPT 142 case 'x': 143 doencrypt = 1; 144 break; 145#endif 146#endif 147 case 'D': 148 no_delay = 1; 149 break; 150 case 'L': 151 log_success = 1; 152 break; 153 case '?': 154 default: 155 usage(); 156 break; 157 } 158 159 argc -= optind; 160 argv += optind; 161 162#ifdef KERBEROS 163 if (use_kerberos && vacuous) { 164 syslog(LOG_ERR, "only one of -k and -v allowed"); 165 exit(2); 166 } 167#ifdef CRYPT 168 if (doencrypt && !use_kerberos) { 169 syslog(LOG_ERR, "-k is required for -x"); 170 exit(2); 171 } 172#endif 173#endif 174 175 fromlen = sizeof (from); 176 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) { 177 syslog(LOG_ERR, "getpeername: %m"); 178 exit(1); 179 } 180 if (keepalive && 181 setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, (char *)&on, 182 sizeof(on)) < 0) 183 syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m"); 184 linger.l_onoff = 1; 185 linger.l_linger = 60; /* XXX */ 186 if (setsockopt(0, SOL_SOCKET, SO_LINGER, (char *)&linger, 187 sizeof (linger)) < 0) 188 syslog(LOG_WARNING, "setsockopt (SO_LINGER): %m"); 189 if (no_delay && 190 setsockopt(0, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) < 0) 191 syslog(LOG_WARNING, "setsockopt (TCP_NODELAY): %m"); 192 doit(&from); 193 /* NOTREACHED */ 194 return(0); 195} 196 197char username[20] = "USER="; 198char homedir[64] = "HOME="; 199char shell[64] = "SHELL="; 200char path[100] = "PATH="; 201char *envinit[] = 202 {homedir, shell, path, username, 0}; 203char **environ; 204 205void 206doit(fromp) 207 struct sockaddr_in *fromp; 208{ 209 extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */ 210 struct hostent *hp; 211 struct passwd *pwd; 212 u_short port; 213 fd_set ready, readfrom; 214 int cc, nfd, pv[2], pid, s; 215 int one = 1; 216 char *hostname, *errorstr; 217 char *cp, sig, buf[BUFSIZ]; 218 char cmdbuf[NCARGS+1], locuser[16], remuser[16]; 219 char fromhost[2 * MAXHOSTNAMELEN + 1]; 220#ifdef LOGIN_CAP 221 login_cap_t *lc; 222#endif 223 224#ifdef KERBEROS 225 AUTH_DAT *kdata = (AUTH_DAT *) NULL; 226 KTEXT ticket = (KTEXT) NULL; 227 char instance[INST_SZ], version[VERSION_SIZE]; 228 struct sockaddr_in fromaddr; 229 int rc; 230 long authopts; 231 int pv1[2], pv2[2]; 232 fd_set wready, writeto; 233 234 fromaddr = *fromp; 235#endif 236 237 (void) signal(SIGINT, SIG_DFL); 238 (void) signal(SIGQUIT, SIG_DFL); 239 (void) signal(SIGTERM, SIG_DFL); 240#ifdef DEBUG 241 { int t = open(_PATH_TTY, 2); 242 if (t >= 0) { 243 ioctl(t, TIOCNOTTY, (char *)0); 244 (void) close(t); 245 } 246 } 247#endif 248 fromp->sin_port = ntohs((u_short)fromp->sin_port); 249 if (fromp->sin_family != AF_INET) { 250 syslog(LOG_ERR, "malformed \"from\" address (af %d)", 251 fromp->sin_family); 252 exit(1); 253 } 254#ifdef IP_OPTIONS 255 { 256 u_char optbuf[BUFSIZ/3]; 257 int optsize = sizeof(optbuf), ipproto, i; 258 struct protoent *ip; 259 260 if ((ip = getprotobyname("ip")) != NULL) 261 ipproto = ip->p_proto; 262 else 263 ipproto = IPPROTO_IP; 264 if (!getsockopt(0, ipproto, IP_OPTIONS, (char *)optbuf, &optsize) && 265 optsize != 0) { 266 for (i = 0; i < optsize; ) { 267 u_char c = optbuf[i]; 268 if (c == IPOPT_LSRR || c == IPOPT_SSRR) { 269 syslog(LOG_NOTICE, 270 "connection refused from %s with IP option %s", 271 inet_ntoa(fromp->sin_addr), 272 c == IPOPT_LSRR ? "LSRR" : "SSRR"); 273 exit(1); 274 } 275 if (c == IPOPT_EOL) 276 break; 277 i += (c == IPOPT_NOP) ? 1 : optbuf[i+1]; 278 } 279 } 280 } 281#endif 282 283#ifdef KERBEROS 284 if (!use_kerberos) 285#endif 286 if (fromp->sin_port >= IPPORT_RESERVED || 287 fromp->sin_port < IPPORT_RESERVED/2) { 288 syslog(LOG_NOTICE|LOG_AUTH, 289 "connection from %s on illegal port %u", 290 inet_ntoa(fromp->sin_addr), 291 fromp->sin_port); 292 exit(1); 293 } 294 295 (void) alarm(60); 296 port = 0; 297 s = 0; /* not set or used if port == 0 */ 298 for (;;) { 299 char c; 300 if ((cc = read(STDIN_FILENO, &c, 1)) != 1) { 301 if (cc < 0) 302 syslog(LOG_NOTICE, "read: %m"); 303 shutdown(0, 1+1); 304 exit(1); 305 } 306 if (c == 0) 307 break; 308 port = port * 10 + c - '0'; 309 } 310 311 (void) alarm(0); 312 if (port != 0) { 313 int lport = IPPORT_RESERVED - 1; 314 s = rresvport(&lport); 315 if (s < 0) { 316 syslog(LOG_ERR, "can't get stderr port: %m"); 317 exit(1); 318 } 319#ifdef KERBEROS 320 if (!use_kerberos) 321#endif 322 if (port >= IPPORT_RESERVED || 323 port < IPPORT_RESERVED/2) { 324 syslog(LOG_NOTICE|LOG_AUTH, 325 "2nd socket from %s on unreserved port %u", 326 inet_ntoa(fromp->sin_addr), 327 port); 328 exit(1); 329 } 330 fromp->sin_port = htons(port); 331 if (connect(s, (struct sockaddr *)fromp, sizeof (*fromp)) < 0) { 332 syslog(LOG_INFO, "connect second port %d: %m", port); 333 exit(1); 334 } 335 } 336 337#ifdef KERBEROS 338 if (vacuous) { 339 error("rshd: remote host requires Kerberos authentication\n"); 340 exit(1); 341 } 342#endif 343 344#ifdef notdef 345 /* from inetd, socket is already on 0, 1, 2 */ 346 dup2(f, 0); 347 dup2(f, 1); 348 dup2(f, 2); 349#endif 350 errorstr = NULL; 351 strncpy(fromhost, inet_ntoa(fromp->sin_addr), 352 sizeof(fromhost) - 1); 353 hostname = fromhost; 354 hp = gethostbyaddr((char *)&fromp->sin_addr, sizeof (struct in_addr), 355 fromp->sin_family); 356 if (hp) { 357 /* 358 * OK, it looks like a DNS name is attached.. Lets see if 359 * it looks like we can use it. If it doesn't check out, 360 * ditch it and use the IP address for logging instead. 361 * Note that iruserok() does it's own hostname checking!! 362 */ 363 strncpy(fromhost, hp->h_name, sizeof(fromhost) - 1); 364 fromhost[sizeof(fromhost) - 1] = 0; 365 hp = gethostbyname(fromhost); 366 if (hp == NULL) { 367 strncpy(fromhost, inet_ntoa(fromp->sin_addr), 368 sizeof(fromhost) - 1); 369 } else for (; ; hp->h_addr_list++) { 370 if (hp->h_addr_list[0] == NULL) { 371 /* End of list - ditch it */ 372 strncpy(fromhost, inet_ntoa(fromp->sin_addr), 373 sizeof(fromhost) - 1); 374 break; 375 } 376 if (!bcmp(hp->h_addr_list[0], 377 (caddr_t)&fromp->sin_addr, 378 sizeof(fromp->sin_addr))) 379 break; /* OK! */ 380 } 381 } 382 fromhost[sizeof(fromhost) - 1] = 0; 383 384#ifdef KERBEROS 385 if (use_kerberos) { 386 kdata = (AUTH_DAT *) authbuf; 387 ticket = (KTEXT) tickbuf; 388 authopts = 0L; 389 strcpy(instance, "*"); 390 version[VERSION_SIZE - 1] = '\0'; 391#ifdef CRYPT 392 if (doencrypt) { 393 struct sockaddr_in local_addr; 394 rc = sizeof(local_addr); 395 if (getsockname(0, (struct sockaddr *)&local_addr, 396 &rc) < 0) { 397 syslog(LOG_ERR, "getsockname: %m"); 398 error("rlogind: getsockname: %m"); 399 exit(1); 400 } 401 authopts = KOPT_DO_MUTUAL; 402 rc = krb_recvauth(authopts, 0, ticket, 403 "rcmd", instance, &fromaddr, 404 &local_addr, kdata, "", schedule, 405 version); 406 des_set_key(&kdata->session, schedule); 407 } else 408#endif 409 rc = krb_recvauth(authopts, 0, ticket, "rcmd", 410 instance, &fromaddr, 411 (struct sockaddr_in *) 0, 412 kdata, "", NULL, version); 413 if (rc != KSUCCESS) { 414 error("Kerberos authentication failure: %s\n", 415 krb_err_txt[rc]); 416 exit(1); 417 } 418 } else 419#endif 420 getstr(remuser, sizeof(remuser), "remuser"); 421 422 getstr(locuser, sizeof(locuser), "locuser"); 423 getstr(cmdbuf, sizeof(cmdbuf), "command"); 424 setpwent(); 425 pwd = getpwnam(locuser); 426 if (pwd == NULL) { 427 syslog(LOG_INFO|LOG_AUTH, 428 "%s@%s as %s: unknown login. cmd='%.80s'", 429 remuser, hostname, locuser, cmdbuf); 430 if (errorstr == NULL) 431 errorstr = "Login incorrect.\n"; 432 goto fail; 433 } 434#ifdef LOGIN_CAP 435 lc = login_getpwclass(pwd); 436#endif 437 if (chdir(pwd->pw_dir) < 0) { 438#ifdef LOGIN_CAP 439 if (chdir("/") < 0 || 440 login_getcapbool(lc, "requirehome", !!pwd->pw_uid)) { 441 syslog(LOG_INFO|LOG_AUTH, 442 "%s@%s as %s: no home directory. cmd='%.80s'", 443 remuser, hostname, locuser, cmdbuf); 444 error("No remote home directory.\n"); 445 exit(0); 446 } 447#else 448 (void) chdir("/"); 449#ifdef notdef 450 syslog(LOG_INFO|LOG_AUTH, 451 "%s@%s as %s: no home directory. cmd='%.80s'", 452 remuser, hostname, locuser, cmdbuf); 453 error("No remote directory.\n"); 454 exit(1); 455#endif 456#endif 457 pwd->pw_dir = "/"; 458 } 459 460#ifdef KERBEROS 461 if (use_kerberos) { 462 if (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0') { 463 if (kuserok(kdata, locuser) != 0) { 464 syslog(LOG_INFO|LOG_AUTH, 465 "Kerberos rsh denied to %s.%s@%s", 466 kdata->pname, kdata->pinst, kdata->prealm); 467 error("Login incorrect.\n"); 468 exit(1); 469 } 470 } 471 } else 472#endif 473 474 if (errorstr || 475 (pwd->pw_expire && time(NULL) >= pwd->pw_expire) || 476 (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' && 477 iruserok(fromp->sin_addr.s_addr, pwd->pw_uid == 0, 478 remuser, locuser) < 0)) { 479 if (__rcmd_errstr) 480 syslog(LOG_INFO|LOG_AUTH, 481 "%s@%s as %s: permission denied (%s). cmd='%.80s'", 482 remuser, hostname, locuser, __rcmd_errstr, 483 cmdbuf); 484 else 485 syslog(LOG_INFO|LOG_AUTH, 486 "%s@%s as %s: permission denied. cmd='%.80s'", 487 remuser, hostname, locuser, cmdbuf); 488fail: 489 if (errorstr == NULL) 490 errorstr = "Login incorrect.\n"; 491 error(errorstr, hostname); 492 exit(1); 493 } 494 495 if (pwd->pw_uid && !access(_PATH_NOLOGIN, F_OK)) { 496 error("Logins currently disabled.\n"); 497 exit(1); 498 } 499#ifdef LOGIN_CAP 500 if (lc != NULL) { 501 char remote_ip[MAXHOSTNAMELEN]; 502 503 strncpy(remote_ip, inet_ntoa(fromp->sin_addr), 504 sizeof(remote_ip) - 1); 505 remote_ip[sizeof(remote_ip) - 1] = 0; 506 if (!auth_hostok(lc, fromhost, remote_ip)) { 507 syslog(LOG_INFO|LOG_AUTH, 508 "%s@%s as %s: permission denied (%s). cmd='%.80s'", 509 remuser, hostname, locuser, __rcmd_errstr, 510 cmdbuf); 511 error("Login incorrect.\n"); 512 exit(1); 513 } 514 if (!auth_timeok(lc, time(NULL))) { 515 error("Logins not available right now\n"); 516 exit(1); 517 } 518 } 519#endif /* !LOGIN_CAP */ 520#if BSD > 43 521 /* before fork, while we're session leader */ 522 if (setlogin(pwd->pw_name) < 0) 523 syslog(LOG_ERR, "setlogin() failed: %m"); 524#endif 525 526 (void) write(STDERR_FILENO, "\0", 1); 527 sent_null = 1; 528 529 if (port) { 530 if (pipe(pv) < 0) { 531 error("Can't make pipe.\n"); 532 exit(1); 533 } 534#ifdef CRYPT 535#ifdef KERBEROS 536 if (doencrypt) { 537 if (pipe(pv1) < 0) { 538 error("Can't make 2nd pipe.\n"); 539 exit(1); 540 } 541 if (pipe(pv2) < 0) { 542 error("Can't make 3rd pipe.\n"); 543 exit(1); 544 } 545 } 546#endif 547#endif 548 pid = fork(); 549 if (pid == -1) { 550 error("Can't fork; try again.\n"); 551 exit(1); 552 } 553 if (pid) { 554#ifdef CRYPT 555#ifdef KERBEROS 556 if (doencrypt) { 557 static char msg[] = SECURE_MESSAGE; 558 (void) close(pv1[1]); 559 (void) close(pv2[1]); 560 des_enc_write(s, msg, sizeof(msg) - 1, 561 schedule, &kdata->session); 562 563 } else 564#endif 565#endif 566 { 567 (void) close(0); 568 (void) close(1); 569 } 570 (void) close(2); 571 (void) close(pv[1]); 572 573 FD_ZERO(&readfrom); 574 FD_SET(s, &readfrom); 575 FD_SET(pv[0], &readfrom); 576 if (pv[0] > s) 577 nfd = pv[0]; 578 else 579 nfd = s; 580#ifdef CRYPT 581#ifdef KERBEROS 582 if (doencrypt) { 583 FD_ZERO(&writeto); 584 FD_SET(pv2[0], &writeto); 585 FD_SET(pv1[0], &readfrom); 586 587 nfd = MAX(nfd, pv2[0]); 588 nfd = MAX(nfd, pv1[0]); 589 } else 590#endif 591#endif 592 ioctl(pv[0], FIONBIO, (char *)&one); 593 594 /* should set s nbio! */ 595 nfd++; 596 do { 597 ready = readfrom; 598#ifdef CRYPT 599#ifdef KERBEROS 600 if (doencrypt) { 601 wready = writeto; 602 if (select(nfd, &ready, 603 &wready, (fd_set *) 0, 604 (struct timeval *) 0) < 0) 605 break; 606 } else 607#endif 608#endif 609 if (select(nfd, &ready, (fd_set *)0, 610 (fd_set *)0, (struct timeval *)0) < 0) 611 break; 612 if (FD_ISSET(s, &ready)) { 613 int ret; 614#ifdef CRYPT 615#ifdef KERBEROS 616 if (doencrypt) 617 ret = des_enc_read(s, &sig, 1, 618 schedule, &kdata->session); 619 else 620#endif 621#endif 622 ret = read(s, &sig, 1); 623 if (ret <= 0) 624 FD_CLR(s, &readfrom); 625 else 626 killpg(pid, sig); 627 } 628 if (FD_ISSET(pv[0], &ready)) { 629 errno = 0; 630 cc = read(pv[0], buf, sizeof(buf)); 631 if (cc <= 0) { 632 shutdown(s, 1+1); 633 FD_CLR(pv[0], &readfrom); 634 } else { 635#ifdef CRYPT 636#ifdef KERBEROS 637 if (doencrypt) 638 (void) 639 des_enc_write(s, buf, cc, 640 schedule, &kdata->session); 641 else 642#endif 643#endif 644 (void) 645 write(s, buf, cc); 646 } 647 } 648#ifdef CRYPT 649#ifdef KERBEROS 650 if (doencrypt && FD_ISSET(pv1[0], &ready)) { 651 errno = 0; 652 cc = read(pv1[0], buf, sizeof(buf)); 653 if (cc <= 0) { 654 shutdown(pv1[0], 1+1); 655 FD_CLR(pv1[0], &readfrom); 656 } else 657 (void) des_enc_write(STDOUT_FILENO, 658 buf, cc, 659 schedule, &kdata->session); 660 } 661 662 if (doencrypt && FD_ISSET(pv2[0], &wready)) { 663 errno = 0; 664 cc = des_enc_read(STDIN_FILENO, 665 buf, sizeof(buf), 666 schedule, &kdata->session); 667 if (cc <= 0) { 668 shutdown(pv2[0], 1+1); 669 FD_CLR(pv2[0], &writeto); 670 } else 671 (void) write(pv2[0], buf, cc); 672 } 673#endif 674#endif 675 676 } while (FD_ISSET(s, &readfrom) || 677#ifdef CRYPT 678#ifdef KERBEROS 679 (doencrypt && FD_ISSET(pv1[0], &readfrom)) || 680#endif 681#endif 682 FD_ISSET(pv[0], &readfrom)); 683 exit(0); 684 } 685 setpgrp(0, getpid()); 686 (void) close(s); 687 (void) close(pv[0]); 688#ifdef CRYPT 689#ifdef KERBEROS 690 if (doencrypt) { 691 close(pv1[0]); close(pv2[0]); 692 dup2(pv1[1], 1); 693 dup2(pv2[1], 0); 694 close(pv1[1]); 695 close(pv2[1]); 696 } 697#endif 698#endif 699 dup2(pv[1], 2); 700 close(pv[1]); 701 } 702 if (*pwd->pw_shell == '\0') 703 pwd->pw_shell = _PATH_BSHELL; 704 environ = envinit; 705 strncat(homedir, pwd->pw_dir, sizeof(homedir)-6); 706 strcat(path, _PATH_DEFPATH); 707 strncat(shell, pwd->pw_shell, sizeof(shell)-7); 708 strncat(username, pwd->pw_name, sizeof(username)-6); 709 cp = strrchr(pwd->pw_shell, '/'); 710 if (cp) 711 cp++; 712 else 713 cp = pwd->pw_shell; 714#ifdef LOGIN_CAP 715 if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETALL) != 0) { 716 syslog(LOG_ERR, "setusercontext: %m"); 717 exit(1); 718 } 719 login_close(lc); 720#else 721 (void) setgid((gid_t)pwd->pw_gid); 722 initgroups(pwd->pw_name, pwd->pw_gid); 723 (void) setuid((uid_t)pwd->pw_uid); 724#endif 725 endpwent(); 726 if (log_success || pwd->pw_uid == 0) { 727#ifdef KERBEROS 728 if (use_kerberos) 729 syslog(LOG_INFO|LOG_AUTH, 730 "Kerberos shell from %s.%s@%s on %s as %s, cmd='%.80s'", 731 kdata->pname, kdata->pinst, kdata->prealm, 732 hostname, locuser, cmdbuf); 733 else 734#endif 735 syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'", 736 remuser, hostname, locuser, cmdbuf); 737 } 738 execl(pwd->pw_shell, cp, "-c", cmdbuf, 0); 739 perror(pwd->pw_shell); 740 exit(1); 741} 742 743/* 744 * Report error to client. Note: can't be used until second socket has 745 * connected to client, or older clients will hang waiting for that 746 * connection first. 747 */ 748#if __STDC__ 749#include <stdarg.h> 750#else 751#include <varargs.h> 752#endif 753 754void 755#if __STDC__ 756error(const char *fmt, ...) 757#else 758error(fmt, va_alist) 759 char *fmt; 760 va_dcl 761#endif 762{ 763 va_list ap; 764 int len; 765 char *bp, buf[BUFSIZ]; 766#if __STDC__ 767 va_start(ap, fmt); 768#else 769 va_start(ap); 770#endif 771 bp = buf; 772 if (sent_null == 0) { 773 *bp++ = 1; 774 len = 1; 775 } else 776 len = 0; 777 (void)vsnprintf(bp, sizeof(buf) - 1, fmt, ap); 778 (void)write(STDERR_FILENO, buf, len + strlen(bp)); 779} 780 781void 782getstr(buf, cnt, err) 783 char *buf, *err; 784 int cnt; 785{ 786 char c; 787 788 do { 789 if (read(STDIN_FILENO, &c, 1) != 1) 790 exit(1); 791 *buf++ = c; 792 if (--cnt == 0) { 793 error("%s too long\n", err); 794 exit(1); 795 } 796 } while (c != 0); 797} 798 799/* 800 * Check whether host h is in our local domain, 801 * defined as sharing the last two components of the domain part, 802 * or the entire domain part if the local domain has only one component. 803 * If either name is unqualified (contains no '.'), 804 * assume that the host is local, as it will be 805 * interpreted as such. 806 */ 807int 808local_domain(h) 809 char *h; 810{ 811 char localhost[MAXHOSTNAMELEN]; 812 char *p1, *p2; 813 814 localhost[0] = 0; 815 (void) gethostname(localhost, sizeof(localhost)); 816 p1 = topdomain(localhost); 817 p2 = topdomain(h); 818 if (p1 == NULL || p2 == NULL || !strcasecmp(p1, p2)) 819 return (1); 820 return (0); 821} 822 823char * 824topdomain(h) 825 char *h; 826{ 827 char *p, *maybe = NULL; 828 int dots = 0; 829 830 for (p = h + strlen(h); p >= h; p--) { 831 if (*p == '.') { 832 if (++dots == 2) 833 return (p); 834 maybe = p; 835 } 836 } 837 return (maybe); 838} 839 840void 841usage() 842{ 843 844 syslog(LOG_ERR, "usage: rshd [-%s]", OPTIONS); 845 exit(2); 846} 847