rshd.c revision 50476
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 "$FreeBSD: head/libexec/rshd/rshd.c 50476 1999-08-28 00:22:10Z peter $"; 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 <libutil.h> 71#include <paths.h> 72#include <pwd.h> 73#include <signal.h> 74#include <stdio.h> 75#include <stdlib.h> 76#include <string.h> 77#include <syslog.h> 78#include <unistd.h> 79#ifdef LOGIN_CAP 80#include <login_cap.h> 81#endif 82 83int keepalive = 1; 84int log_success; /* If TRUE, log all successful accesses */ 85int sent_null; 86int no_delay; 87 88void doit __P((struct sockaddr_in *)); 89void error __P((const char *, ...)); 90void getstr __P((char *, int, char *)); 91int local_domain __P((char *)); 92char *topdomain __P((char *)); 93void usage __P((void)); 94 95#ifdef KERBEROS 96#include <des.h> 97#include <krb.h> 98#define VERSION_SIZE 9 99#define SECURE_MESSAGE "This rsh session is using DES encryption for all transmissions.\r\n" 100#define OPTIONS "alnkvxDL" 101char authbuf[sizeof(AUTH_DAT)]; 102char tickbuf[sizeof(KTEXT_ST)]; 103int doencrypt, use_kerberos, vacuous; 104Key_schedule schedule; 105#else 106#define OPTIONS "alnDL" 107#endif 108 109int 110main(argc, argv) 111 int argc; 112 char *argv[]; 113{ 114 extern int __check_rhosts_file; 115 struct linger linger; 116 int ch, on = 1, fromlen; 117 struct sockaddr_in from; 118 119 openlog("rshd", LOG_PID | LOG_ODELAY, LOG_DAEMON); 120 121 opterr = 0; 122 while ((ch = getopt(argc, argv, OPTIONS)) != -1) 123 switch (ch) { 124 case 'a': 125 /* ignored for compatability */ 126 break; 127 case 'l': 128 __check_rhosts_file = 0; 129 break; 130 case 'n': 131 keepalive = 0; 132 break; 133#ifdef KERBEROS 134 case 'k': 135 use_kerberos = 1; 136 break; 137 138 case 'v': 139 vacuous = 1; 140 break; 141 142#ifdef CRYPT 143 case 'x': 144 doencrypt = 1; 145 break; 146#endif 147#endif 148 case 'D': 149 no_delay = 1; 150 break; 151 case 'L': 152 log_success = 1; 153 break; 154 case '?': 155 default: 156 usage(); 157 break; 158 } 159 160 argc -= optind; 161 argv += optind; 162 163#ifdef KERBEROS 164 if (use_kerberos && vacuous) { 165 syslog(LOG_ERR, "only one of -k and -v allowed"); 166 exit(2); 167 } 168#ifdef CRYPT 169 if (doencrypt && !use_kerberos) { 170 syslog(LOG_ERR, "-k is required for -x"); 171 exit(2); 172 } 173#endif 174#endif 175 176 fromlen = sizeof (from); 177 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) { 178 syslog(LOG_ERR, "getpeername: %m"); 179 exit(1); 180 } 181 if (keepalive && 182 setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, (char *)&on, 183 sizeof(on)) < 0) 184 syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m"); 185 linger.l_onoff = 1; 186 linger.l_linger = 60; /* XXX */ 187 if (setsockopt(0, SOL_SOCKET, SO_LINGER, (char *)&linger, 188 sizeof (linger)) < 0) 189 syslog(LOG_WARNING, "setsockopt (SO_LINGER): %m"); 190 if (no_delay && 191 setsockopt(0, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) < 0) 192 syslog(LOG_WARNING, "setsockopt (TCP_NODELAY): %m"); 193 doit(&from); 194 /* NOTREACHED */ 195 return(0); 196} 197 198char username[20] = "USER="; 199char homedir[64] = "HOME="; 200char shell[64] = "SHELL="; 201char path[100] = "PATH="; 202char *envinit[] = 203 {homedir, shell, path, username, 0}; 204char **environ; 205 206void 207doit(fromp) 208 struct sockaddr_in *fromp; 209{ 210 extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */ 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 *errorstr; 217 char *cp, sig, buf[BUFSIZ]; 218 char cmdbuf[NCARGS+1], locuser[16], remuser[16]; 219 char fromhost[MAXHOSTNAMELEN]; 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 realhostname(fromhost, sizeof(fromhost) - 1, &fromp->sin_addr); 352 fromhost[sizeof(fromhost) - 1] = '\0'; 353 354#ifdef KERBEROS 355 if (use_kerberos) { 356 kdata = (AUTH_DAT *) authbuf; 357 ticket = (KTEXT) tickbuf; 358 authopts = 0L; 359 strcpy(instance, "*"); 360 version[VERSION_SIZE - 1] = '\0'; 361#ifdef CRYPT 362 if (doencrypt) { 363 struct sockaddr_in local_addr; 364 rc = sizeof(local_addr); 365 if (getsockname(0, (struct sockaddr *)&local_addr, 366 &rc) < 0) { 367 syslog(LOG_ERR, "getsockname: %m"); 368 error("rlogind: getsockname: %m"); 369 exit(1); 370 } 371 authopts = KOPT_DO_MUTUAL; 372 rc = krb_recvauth(authopts, 0, ticket, 373 "rcmd", instance, &fromaddr, 374 &local_addr, kdata, "", schedule, 375 version); 376 des_set_key(&kdata->session, schedule); 377 } else 378#endif 379 rc = krb_recvauth(authopts, 0, ticket, "rcmd", 380 instance, &fromaddr, 381 (struct sockaddr_in *) 0, 382 kdata, "", NULL, version); 383 if (rc != KSUCCESS) { 384 error("Kerberos authentication failure: %s\n", 385 krb_err_txt[rc]); 386 exit(1); 387 } 388 } else 389#endif 390 getstr(remuser, sizeof(remuser), "remuser"); 391 392 getstr(locuser, sizeof(locuser), "locuser"); 393 getstr(cmdbuf, sizeof(cmdbuf), "command"); 394 setpwent(); 395 pwd = getpwnam(locuser); 396 if (pwd == NULL) { 397 syslog(LOG_INFO|LOG_AUTH, 398 "%s@%s as %s: unknown login. cmd='%.80s'", 399 remuser, fromhost, locuser, cmdbuf); 400 if (errorstr == NULL) 401 errorstr = "Login incorrect.\n"; 402 goto fail; 403 } 404#ifdef LOGIN_CAP 405 lc = login_getpwclass(pwd); 406#endif 407 if (chdir(pwd->pw_dir) < 0) { 408#ifdef LOGIN_CAP 409 if (chdir("/") < 0 || 410 login_getcapbool(lc, "requirehome", !!pwd->pw_uid)) { 411 syslog(LOG_INFO|LOG_AUTH, 412 "%s@%s as %s: no home directory. cmd='%.80s'", 413 remuser, fromhost, locuser, cmdbuf); 414 error("No remote home directory.\n"); 415 exit(0); 416 } 417#else 418 (void) chdir("/"); 419#ifdef notdef 420 syslog(LOG_INFO|LOG_AUTH, 421 "%s@%s as %s: no home directory. cmd='%.80s'", 422 remuser, fromhost, locuser, cmdbuf); 423 error("No remote directory.\n"); 424 exit(1); 425#endif 426#endif 427 pwd->pw_dir = "/"; 428 } 429 430#ifdef KERBEROS 431 if (use_kerberos) { 432 if (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0') { 433 if (kuserok(kdata, locuser) != 0) { 434 syslog(LOG_INFO|LOG_AUTH, 435 "Kerberos rsh denied to %s.%s@%s", 436 kdata->pname, kdata->pinst, kdata->prealm); 437 error("Login incorrect.\n"); 438 exit(1); 439 } 440 } 441 } else 442#endif 443 444 if (errorstr || 445 (pwd->pw_expire && time(NULL) >= pwd->pw_expire) || 446 (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' && 447 iruserok(fromp->sin_addr.s_addr, pwd->pw_uid == 0, 448 remuser, locuser) < 0)) { 449 if (__rcmd_errstr) 450 syslog(LOG_INFO|LOG_AUTH, 451 "%s@%s as %s: permission denied (%s). cmd='%.80s'", 452 remuser, fromhost, locuser, __rcmd_errstr, 453 cmdbuf); 454 else 455 syslog(LOG_INFO|LOG_AUTH, 456 "%s@%s as %s: permission denied. cmd='%.80s'", 457 remuser, fromhost, locuser, cmdbuf); 458fail: 459 if (errorstr == NULL) 460 errorstr = "Login incorrect.\n"; 461 error(errorstr, fromhost); 462 exit(1); 463 } 464 465 if (pwd->pw_uid && !access(_PATH_NOLOGIN, F_OK)) { 466 error("Logins currently disabled.\n"); 467 exit(1); 468 } 469#ifdef LOGIN_CAP 470 if (lc != NULL) { 471 char remote_ip[MAXHOSTNAMELEN]; 472 473 strncpy(remote_ip, inet_ntoa(fromp->sin_addr), 474 sizeof(remote_ip) - 1); 475 remote_ip[sizeof(remote_ip) - 1] = 0; 476 if (!auth_hostok(lc, fromhost, remote_ip)) { 477 syslog(LOG_INFO|LOG_AUTH, 478 "%s@%s as %s: permission denied (%s). cmd='%.80s'", 479 remuser, fromhost, locuser, __rcmd_errstr, 480 cmdbuf); 481 error("Login incorrect.\n"); 482 exit(1); 483 } 484 if (!auth_timeok(lc, time(NULL))) { 485 error("Logins not available right now\n"); 486 exit(1); 487 } 488 } 489#endif /* !LOGIN_CAP */ 490#if BSD > 43 491 /* before fork, while we're session leader */ 492 if (setlogin(pwd->pw_name) < 0) 493 syslog(LOG_ERR, "setlogin() failed: %m"); 494#endif 495 496 (void) write(STDERR_FILENO, "\0", 1); 497 sent_null = 1; 498 499 if (port) { 500 if (pipe(pv) < 0) { 501 error("Can't make pipe.\n"); 502 exit(1); 503 } 504#ifdef CRYPT 505#ifdef KERBEROS 506 if (doencrypt) { 507 if (pipe(pv1) < 0) { 508 error("Can't make 2nd pipe.\n"); 509 exit(1); 510 } 511 if (pipe(pv2) < 0) { 512 error("Can't make 3rd pipe.\n"); 513 exit(1); 514 } 515 } 516#endif 517#endif 518 pid = fork(); 519 if (pid == -1) { 520 error("Can't fork; try again.\n"); 521 exit(1); 522 } 523 if (pid) { 524#ifdef CRYPT 525#ifdef KERBEROS 526 if (doencrypt) { 527 static char msg[] = SECURE_MESSAGE; 528 (void) close(pv1[1]); 529 (void) close(pv2[1]); 530 des_enc_write(s, msg, sizeof(msg) - 1, 531 schedule, &kdata->session); 532 533 } else 534#endif 535#endif 536 { 537 (void) close(0); 538 (void) close(1); 539 } 540 (void) close(2); 541 (void) close(pv[1]); 542 543 FD_ZERO(&readfrom); 544 FD_SET(s, &readfrom); 545 FD_SET(pv[0], &readfrom); 546 if (pv[0] > s) 547 nfd = pv[0]; 548 else 549 nfd = s; 550#ifdef CRYPT 551#ifdef KERBEROS 552 if (doencrypt) { 553 FD_ZERO(&writeto); 554 FD_SET(pv2[0], &writeto); 555 FD_SET(pv1[0], &readfrom); 556 557 nfd = MAX(nfd, pv2[0]); 558 nfd = MAX(nfd, pv1[0]); 559 } else 560#endif 561#endif 562 ioctl(pv[0], FIONBIO, (char *)&one); 563 564 /* should set s nbio! */ 565 nfd++; 566 do { 567 ready = readfrom; 568#ifdef CRYPT 569#ifdef KERBEROS 570 if (doencrypt) { 571 wready = writeto; 572 if (select(nfd, &ready, 573 &wready, (fd_set *) 0, 574 (struct timeval *) 0) < 0) 575 break; 576 } else 577#endif 578#endif 579 if (select(nfd, &ready, (fd_set *)0, 580 (fd_set *)0, (struct timeval *)0) < 0) 581 break; 582 if (FD_ISSET(s, &ready)) { 583 int ret; 584#ifdef CRYPT 585#ifdef KERBEROS 586 if (doencrypt) 587 ret = des_enc_read(s, &sig, 1, 588 schedule, &kdata->session); 589 else 590#endif 591#endif 592 ret = read(s, &sig, 1); 593 if (ret <= 0) 594 FD_CLR(s, &readfrom); 595 else 596 killpg(pid, sig); 597 } 598 if (FD_ISSET(pv[0], &ready)) { 599 errno = 0; 600 cc = read(pv[0], buf, sizeof(buf)); 601 if (cc <= 0) { 602 shutdown(s, 1+1); 603 FD_CLR(pv[0], &readfrom); 604 } else { 605#ifdef CRYPT 606#ifdef KERBEROS 607 if (doencrypt) 608 (void) 609 des_enc_write(s, buf, cc, 610 schedule, &kdata->session); 611 else 612#endif 613#endif 614 (void) 615 write(s, buf, cc); 616 } 617 } 618#ifdef CRYPT 619#ifdef KERBEROS 620 if (doencrypt && FD_ISSET(pv1[0], &ready)) { 621 errno = 0; 622 cc = read(pv1[0], buf, sizeof(buf)); 623 if (cc <= 0) { 624 shutdown(pv1[0], 1+1); 625 FD_CLR(pv1[0], &readfrom); 626 } else 627 (void) des_enc_write(STDOUT_FILENO, 628 buf, cc, 629 schedule, &kdata->session); 630 } 631 632 if (doencrypt && FD_ISSET(pv2[0], &wready)) { 633 errno = 0; 634 cc = des_enc_read(STDIN_FILENO, 635 buf, sizeof(buf), 636 schedule, &kdata->session); 637 if (cc <= 0) { 638 shutdown(pv2[0], 1+1); 639 FD_CLR(pv2[0], &writeto); 640 } else 641 (void) write(pv2[0], buf, cc); 642 } 643#endif 644#endif 645 646 } while (FD_ISSET(s, &readfrom) || 647#ifdef CRYPT 648#ifdef KERBEROS 649 (doencrypt && FD_ISSET(pv1[0], &readfrom)) || 650#endif 651#endif 652 FD_ISSET(pv[0], &readfrom)); 653 exit(0); 654 } 655 setpgrp(0, getpid()); 656 (void) close(s); 657 (void) close(pv[0]); 658#ifdef CRYPT 659#ifdef KERBEROS 660 if (doencrypt) { 661 close(pv1[0]); close(pv2[0]); 662 dup2(pv1[1], 1); 663 dup2(pv2[1], 0); 664 close(pv1[1]); 665 close(pv2[1]); 666 } 667#endif 668#endif 669 dup2(pv[1], 2); 670 close(pv[1]); 671 } 672 if (*pwd->pw_shell == '\0') 673 pwd->pw_shell = _PATH_BSHELL; 674 environ = envinit; 675 strncat(homedir, pwd->pw_dir, sizeof(homedir)-6); 676 strcat(path, _PATH_DEFPATH); 677 strncat(shell, pwd->pw_shell, sizeof(shell)-7); 678 strncat(username, pwd->pw_name, sizeof(username)-6); 679 cp = strrchr(pwd->pw_shell, '/'); 680 if (cp) 681 cp++; 682 else 683 cp = pwd->pw_shell; 684#ifdef LOGIN_CAP 685 if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETALL) != 0) { 686 syslog(LOG_ERR, "setusercontext: %m"); 687 exit(1); 688 } 689 login_close(lc); 690#else 691 (void) setgid((gid_t)pwd->pw_gid); 692 initgroups(pwd->pw_name, pwd->pw_gid); 693 (void) setuid((uid_t)pwd->pw_uid); 694#endif 695 endpwent(); 696 if (log_success || pwd->pw_uid == 0) { 697#ifdef KERBEROS 698 if (use_kerberos) 699 syslog(LOG_INFO|LOG_AUTH, 700 "Kerberos shell from %s.%s@%s on %s as %s, cmd='%.80s'", 701 kdata->pname, kdata->pinst, kdata->prealm, 702 fromhost, locuser, cmdbuf); 703 else 704#endif 705 syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'", 706 remuser, fromhost, locuser, cmdbuf); 707 } 708 execl(pwd->pw_shell, cp, "-c", cmdbuf, 0); 709 perror(pwd->pw_shell); 710 exit(1); 711} 712 713/* 714 * Report error to client. Note: can't be used until second socket has 715 * connected to client, or older clients will hang waiting for that 716 * connection first. 717 */ 718#if __STDC__ 719#include <stdarg.h> 720#else 721#include <varargs.h> 722#endif 723 724void 725#if __STDC__ 726error(const char *fmt, ...) 727#else 728error(fmt, va_alist) 729 char *fmt; 730 va_dcl 731#endif 732{ 733 va_list ap; 734 int len; 735 char *bp, buf[BUFSIZ]; 736#if __STDC__ 737 va_start(ap, fmt); 738#else 739 va_start(ap); 740#endif 741 bp = buf; 742 if (sent_null == 0) { 743 *bp++ = 1; 744 len = 1; 745 } else 746 len = 0; 747 (void)vsnprintf(bp, sizeof(buf) - 1, fmt, ap); 748 (void)write(STDERR_FILENO, buf, len + strlen(bp)); 749} 750 751void 752getstr(buf, cnt, err) 753 char *buf, *err; 754 int cnt; 755{ 756 char c; 757 758 do { 759 if (read(STDIN_FILENO, &c, 1) != 1) 760 exit(1); 761 *buf++ = c; 762 if (--cnt == 0) { 763 error("%s too long\n", err); 764 exit(1); 765 } 766 } while (c != 0); 767} 768 769/* 770 * Check whether host h is in our local domain, 771 * defined as sharing the last two components of the domain part, 772 * or the entire domain part if the local domain has only one component. 773 * If either name is unqualified (contains no '.'), 774 * assume that the host is local, as it will be 775 * interpreted as such. 776 */ 777int 778local_domain(h) 779 char *h; 780{ 781 char localhost[MAXHOSTNAMELEN]; 782 char *p1, *p2; 783 784 localhost[0] = 0; 785 (void) gethostname(localhost, sizeof(localhost) - 1); 786 localhost[sizeof(localhost) - 1] = '\0'; 787 p1 = topdomain(localhost); 788 p2 = topdomain(h); 789 if (p1 == NULL || p2 == NULL || !strcasecmp(p1, p2)) 790 return (1); 791 return (0); 792} 793 794char * 795topdomain(h) 796 char *h; 797{ 798 char *p, *maybe = NULL; 799 int dots = 0; 800 801 for (p = h + strlen(h); p >= h; p--) { 802 if (*p == '.') { 803 if (++dots == 2) 804 return (p); 805 maybe = p; 806 } 807 } 808 return (maybe); 809} 810 811void 812usage() 813{ 814 815 syslog(LOG_ERR, "usage: rshd [-%s]", OPTIONS); 816 exit(2); 817} 818