1 /* 2 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 3 * All rights reserved 4 * 5 * As far as I am concerned, the code I have written for this software 6 * can be used freely for any purpose. Any derived versions of this 7 * software must be clearly marked as such, and if the derived work is 8 * incompatible with the protocol description in the RFC file, it must be 9 * called by a name other than "ssh" or "Secure Shell". 10 * 11 * SSH2 support by Markus Friedl. 12 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 #include "includes.h" 36 RCSID("$OpenBSD: session.c,v 1.180 2004/07/28 09:40:29 markus Exp $"); 37 RCSID("$FreeBSD$"); 38 39 #include "ssh.h" 40 #include "ssh1.h" 41 #include "ssh2.h" 42 #include "xmalloc.h" 43 #include "sshpty.h" 44 #include "packet.h" 45 #include "buffer.h" 46 #include "match.h" 47 #include "uidswap.h" 48 #include "compat.h" 49 #include "channels.h" 50 #include "bufaux.h" 51 #include "auth.h" 52 #include "auth-options.h" 53 #include "pathnames.h" 54 #include "log.h" 55 #include "servconf.h" 56 #include "sshlogin.h" 57 #include "serverloop.h" 58 #include "canohost.h" 59 #include "session.h" 60 #include "monitor_wrap.h" 61 62 #if defined(KRB5) && defined(USE_AFS) 63 #include <kafs.h> 64 #endif 65 66 #ifdef GSSAPI 67 #include "ssh-gss.h" 68 #endif 69 70 /* func */ 71 72 Session *session_new(void); 73 void session_set_fds(Session *, int, int, int); 74 void session_pty_cleanup(Session *); 75 void session_proctitle(Session *); 76 int session_setup_x11fwd(Session *); 77 void do_exec_pty(Session *, const char *); 78 void do_exec_no_pty(Session *, const char *); 79 void do_exec(Session *, const char *); 80 void do_login(Session *, const char *); 81 #ifdef LOGIN_NEEDS_UTMPX 82 static void do_pre_login(Session *s); 83 #endif 84 void do_child(Session *, const char *); 85 void do_motd(void); 86 int check_quietlogin(Session *, const char *); 87 88 static void do_authenticated1(Authctxt *); 89 static void do_authenticated2(Authctxt *); 90 91 static int session_pty_req(Session *); 92 93 /* import */ 94 extern ServerOptions options; 95 extern char *__progname; 96 extern int log_stderr; 97 extern int debug_flag; 98 extern u_int utmp_len; 99 extern int startup_pipe; 100 extern void destroy_sensitive_data(void); 101 extern Buffer loginmsg; 102 103 /* original command from peer. */ 104 const char *original_command = NULL; 105 106 /* data */ 107 #define MAX_SESSIONS 10 108 Session sessions[MAX_SESSIONS]; 109 110 #ifdef HAVE_LOGIN_CAP 111 login_cap_t *lc; 112 #endif 113 114 static int is_child = 0; 115 116 /* Name and directory of socket for authentication agent forwarding. */ 117 static char *auth_sock_name = NULL; 118 static char *auth_sock_dir = NULL; 119 120 /* removes the agent forwarding socket */ 121 122 static void 123 auth_sock_cleanup_proc(struct passwd *pw) 124 { 125 if (auth_sock_name != NULL) { 126 temporarily_use_uid(pw); 127 unlink(auth_sock_name); 128 rmdir(auth_sock_dir); 129 auth_sock_name = NULL; 130 restore_uid(); 131 } 132 } 133 134 static int 135 auth_input_request_forwarding(struct passwd * pw) 136 { 137 Channel *nc; 138 int sock; 139 struct sockaddr_un sunaddr; 140 141 if (auth_sock_name != NULL) { 142 error("authentication forwarding requested twice."); 143 return 0; 144 } 145 146 /* Temporarily drop privileged uid for mkdir/bind. */ 147 temporarily_use_uid(pw); 148 149 /* Allocate a buffer for the socket name, and format the name. */ 150 auth_sock_name = xmalloc(MAXPATHLEN); 151 auth_sock_dir = xmalloc(MAXPATHLEN); 152 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN); 153 154 /* Create private directory for socket */ 155 if (mkdtemp(auth_sock_dir) == NULL) { 156 packet_send_debug("Agent forwarding disabled: " 157 "mkdtemp() failed: %.100s", strerror(errno)); 158 restore_uid(); 159 xfree(auth_sock_name); 160 xfree(auth_sock_dir); 161 auth_sock_name = NULL; 162 auth_sock_dir = NULL; 163 return 0; 164 } 165 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld", 166 auth_sock_dir, (long) getpid()); 167 168 /* Create the socket. */ 169 sock = socket(AF_UNIX, SOCK_STREAM, 0); 170 if (sock < 0) 171 packet_disconnect("socket: %.100s", strerror(errno)); 172 173 /* Bind it to the name. */ 174 memset(&sunaddr, 0, sizeof(sunaddr)); 175 sunaddr.sun_family = AF_UNIX; 176 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path)); 177 178 if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) 179 packet_disconnect("bind: %.100s", strerror(errno)); 180 181 /* Restore the privileged uid. */ 182 restore_uid(); 183 184 /* Start listening on the socket. */ 185 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) 186 packet_disconnect("listen: %.100s", strerror(errno)); 187 188 /* Allocate a channel for the authentication agent socket. */ 189 nc = channel_new("auth socket", 190 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1, 191 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 192 0, "auth socket", 1); 193 strlcpy(nc->path, auth_sock_name, sizeof(nc->path)); 194 return 1; 195 } 196 197 static void 198 display_loginmsg(void) 199 { 200 if (buffer_len(&loginmsg) > 0) { 201 buffer_append(&loginmsg, "\0", 1); 202 printf("%s", (char *)buffer_ptr(&loginmsg)); 203 buffer_clear(&loginmsg); 204 } 205 } 206 207 void 208 do_authenticated(Authctxt *authctxt) 209 { 210 setproctitle("%s", authctxt->pw->pw_name); 211 212 /* 213 * Cancel the alarm we set to limit the time taken for 214 * authentication. 215 */ 216 alarm(0); 217 if (startup_pipe != -1) { 218 close(startup_pipe); 219 startup_pipe = -1; 220 } 221 /* setup the channel layer */ 222 if (!no_port_forwarding_flag && options.allow_tcp_forwarding) 223 channel_permit_all_opens(); 224 225 if (compat20) 226 do_authenticated2(authctxt); 227 else 228 do_authenticated1(authctxt); 229 230 do_cleanup(authctxt); 231 } 232 233 /* 234 * Prepares for an interactive session. This is called after the user has 235 * been successfully authenticated. During this message exchange, pseudo 236 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings 237 * are requested, etc. 238 */ 239 static void 240 do_authenticated1(Authctxt *authctxt) 241 { 242 Session *s; 243 char *command; 244 int success, type, screen_flag; 245 int enable_compression_after_reply = 0; 246 u_int proto_len, data_len, dlen, compression_level = 0; 247 248 s = session_new(); 249 s->authctxt = authctxt; 250 s->pw = authctxt->pw; 251 252 /* 253 * We stay in this loop until the client requests to execute a shell 254 * or a command. 255 */ 256 for (;;) { 257 success = 0; 258 259 /* Get a packet from the client. */ 260 type = packet_read(); 261 262 /* Process the packet. */ 263 switch (type) { 264 case SSH_CMSG_REQUEST_COMPRESSION: 265 compression_level = packet_get_int(); 266 packet_check_eom(); 267 if (compression_level < 1 || compression_level > 9) { 268 packet_send_debug("Received invalid compression level %d.", 269 compression_level); 270 break; 271 } 272 if (!options.compression) { 273 debug2("compression disabled"); 274 break; 275 } 276 /* Enable compression after we have responded with SUCCESS. */ 277 enable_compression_after_reply = 1; 278 success = 1; 279 break; 280 281 case SSH_CMSG_REQUEST_PTY: 282 success = session_pty_req(s); 283 break; 284 285 case SSH_CMSG_X11_REQUEST_FORWARDING: 286 s->auth_proto = packet_get_string(&proto_len); 287 s->auth_data = packet_get_string(&data_len); 288 289 screen_flag = packet_get_protocol_flags() & 290 SSH_PROTOFLAG_SCREEN_NUMBER; 291 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag); 292 293 if (packet_remaining() == 4) { 294 if (!screen_flag) 295 debug2("Buggy client: " 296 "X11 screen flag missing"); 297 s->screen = packet_get_int(); 298 } else { 299 s->screen = 0; 300 } 301 packet_check_eom(); 302 success = session_setup_x11fwd(s); 303 if (!success) { 304 xfree(s->auth_proto); 305 xfree(s->auth_data); 306 s->auth_proto = NULL; 307 s->auth_data = NULL; 308 } 309 break; 310 311 case SSH_CMSG_AGENT_REQUEST_FORWARDING: 312 if (no_agent_forwarding_flag || compat13) { 313 debug("Authentication agent forwarding not permitted for this authentication."); 314 break; 315 } 316 debug("Received authentication agent forwarding request."); 317 success = auth_input_request_forwarding(s->pw); 318 break; 319 320 case SSH_CMSG_PORT_FORWARD_REQUEST: 321 if (no_port_forwarding_flag) { 322 debug("Port forwarding not permitted for this authentication."); 323 break; 324 } 325 if (!options.allow_tcp_forwarding) { 326 debug("Port forwarding not permitted."); 327 break; 328 } 329 debug("Received TCP/IP port forwarding request."); 330 channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports); 331 success = 1; 332 break; 333 334 case SSH_CMSG_MAX_PACKET_SIZE: 335 if (packet_set_maxsize(packet_get_int()) > 0) 336 success = 1; 337 break; 338 339 case SSH_CMSG_EXEC_SHELL: 340 case SSH_CMSG_EXEC_CMD: 341 if (type == SSH_CMSG_EXEC_CMD) { 342 command = packet_get_string(&dlen); 343 debug("Exec command '%.500s'", command); 344 do_exec(s, command); 345 xfree(command); 346 } else { 347 do_exec(s, NULL); 348 } 349 packet_check_eom(); 350 session_close(s); 351 return; 352 353 default: 354 /* 355 * Any unknown messages in this phase are ignored, 356 * and a failure message is returned. 357 */ 358 logit("Unknown packet type received after authentication: %d", type); 359 } 360 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); 361 packet_send(); 362 packet_write_wait(); 363 364 /* Enable compression now that we have replied if appropriate. */ 365 if (enable_compression_after_reply) { 366 enable_compression_after_reply = 0; 367 packet_start_compression(compression_level); 368 } 369 } 370 } 371 372 /* 373 * This is called to fork and execute a command when we have no tty. This 374 * will call do_child from the child, and server_loop from the parent after 375 * setting up file descriptors and such. 376 */ 377 void 378 do_exec_no_pty(Session *s, const char *command) 379 { 380 pid_t pid; 381 382 #ifdef USE_PIPES 383 int pin[2], pout[2], perr[2]; 384 /* Allocate pipes for communicating with the program. */ 385 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) 386 packet_disconnect("Could not create pipes: %.100s", 387 strerror(errno)); 388 #else /* USE_PIPES */ 389 int inout[2], err[2]; 390 /* Uses socket pairs to communicate with the program. */ 391 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || 392 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) 393 packet_disconnect("Could not create socket pairs: %.100s", 394 strerror(errno)); 395 #endif /* USE_PIPES */ 396 if (s == NULL) 397 fatal("do_exec_no_pty: no session"); 398 399 session_proctitle(s); 400 401 #if defined(USE_PAM) 402 if (options.use_pam && !use_privsep) 403 do_pam_setcred(1); 404 #endif /* USE_PAM */ 405 406 /* Fork the child. */ 407 if ((pid = fork()) == 0) { 408 is_child = 1; 409 410 /* Child. Reinitialize the log since the pid has changed. */ 411 log_init(__progname, options.log_level, options.log_facility, log_stderr); 412 413 /* 414 * Create a new session and process group since the 4.4BSD 415 * setlogin() affects the entire process group. 416 */ 417 if (setsid() < 0) 418 error("setsid failed: %.100s", strerror(errno)); 419 420 #ifdef USE_PIPES 421 /* 422 * Redirect stdin. We close the parent side of the socket 423 * pair, and make the child side the standard input. 424 */ 425 close(pin[1]); 426 if (dup2(pin[0], 0) < 0) 427 perror("dup2 stdin"); 428 close(pin[0]); 429 430 /* Redirect stdout. */ 431 close(pout[0]); 432 if (dup2(pout[1], 1) < 0) 433 perror("dup2 stdout"); 434 close(pout[1]); 435 436 /* Redirect stderr. */ 437 close(perr[0]); 438 if (dup2(perr[1], 2) < 0) 439 perror("dup2 stderr"); 440 close(perr[1]); 441 #else /* USE_PIPES */ 442 /* 443 * Redirect stdin, stdout, and stderr. Stdin and stdout will 444 * use the same socket, as some programs (particularly rdist) 445 * seem to depend on it. 446 */ 447 close(inout[1]); 448 close(err[1]); 449 if (dup2(inout[0], 0) < 0) /* stdin */ 450 perror("dup2 stdin"); 451 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ 452 perror("dup2 stdout"); 453 if (dup2(err[0], 2) < 0) /* stderr */ 454 perror("dup2 stderr"); 455 #endif /* USE_PIPES */ 456 457 #ifdef _UNICOS 458 cray_init_job(s->pw); /* set up cray jid and tmpdir */ 459 #endif 460 461 /* Do processing for the child (exec command etc). */ 462 do_child(s, command); 463 /* NOTREACHED */ 464 } 465 #ifdef _UNICOS 466 signal(WJSIGNAL, cray_job_termination_handler); 467 #endif /* _UNICOS */ 468 #ifdef HAVE_CYGWIN 469 if (is_winnt) 470 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); 471 #endif 472 if (pid < 0) 473 packet_disconnect("fork failed: %.100s", strerror(errno)); 474 s->pid = pid; 475 /* Set interactive/non-interactive mode. */ 476 packet_set_interactive(s->display != NULL); 477 #ifdef USE_PIPES 478 /* We are the parent. Close the child sides of the pipes. */ 479 close(pin[0]); 480 close(pout[1]); 481 close(perr[1]); 482 483 if (compat20) { 484 if (s->is_subsystem) { 485 close(perr[0]); 486 perr[0] = -1; 487 } 488 session_set_fds(s, pin[1], pout[0], perr[0]); 489 } else { 490 /* Enter the interactive session. */ 491 server_loop(pid, pin[1], pout[0], perr[0]); 492 /* server_loop has closed pin[1], pout[0], and perr[0]. */ 493 } 494 #else /* USE_PIPES */ 495 /* We are the parent. Close the child sides of the socket pairs. */ 496 close(inout[0]); 497 close(err[0]); 498 499 /* 500 * Clear loginmsg, since it's the child's responsibility to display 501 * it to the user, otherwise multiple sessions may accumulate 502 * multiple copies of the login messages. 503 */ 504 buffer_clear(&loginmsg); 505 506 /* 507 * Enter the interactive session. Note: server_loop must be able to 508 * handle the case that fdin and fdout are the same. 509 */ 510 if (compat20) { 511 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]); 512 } else { 513 server_loop(pid, inout[1], inout[1], err[1]); 514 /* server_loop has closed inout[1] and err[1]. */ 515 } 516 #endif /* USE_PIPES */ 517 } 518 519 /* 520 * This is called to fork and execute a command when we have a tty. This 521 * will call do_child from the child, and server_loop from the parent after 522 * setting up file descriptors, controlling tty, updating wtmp, utmp, 523 * lastlog, and other such operations. 524 */ 525 void 526 do_exec_pty(Session *s, const char *command) 527 { 528 int fdout, ptyfd, ttyfd, ptymaster; 529 pid_t pid; 530 531 if (s == NULL) 532 fatal("do_exec_pty: no session"); 533 ptyfd = s->ptyfd; 534 ttyfd = s->ttyfd; 535 536 #if defined(USE_PAM) 537 if (options.use_pam) { 538 do_pam_set_tty(s->tty); 539 if (!use_privsep) 540 do_pam_setcred(1); 541 } 542 #endif 543 544 /* Fork the child. */ 545 if ((pid = fork()) == 0) { 546 is_child = 1; 547 548 /* Child. Reinitialize the log because the pid has changed. */ 549 log_init(__progname, options.log_level, options.log_facility, log_stderr); 550 /* Close the master side of the pseudo tty. */ 551 close(ptyfd); 552 553 /* Make the pseudo tty our controlling tty. */ 554 pty_make_controlling_tty(&ttyfd, s->tty); 555 556 /* Redirect stdin/stdout/stderr from the pseudo tty. */ 557 if (dup2(ttyfd, 0) < 0) 558 error("dup2 stdin: %s", strerror(errno)); 559 if (dup2(ttyfd, 1) < 0) 560 error("dup2 stdout: %s", strerror(errno)); 561 if (dup2(ttyfd, 2) < 0) 562 error("dup2 stderr: %s", strerror(errno)); 563 564 /* Close the extra descriptor for the pseudo tty. */ 565 close(ttyfd); 566 567 /* record login, etc. similar to login(1) */ 568 #ifndef HAVE_OSF_SIA 569 if (!(options.use_login && command == NULL)) { 570 #ifdef _UNICOS 571 cray_init_job(s->pw); /* set up cray jid and tmpdir */ 572 #endif /* _UNICOS */ 573 do_login(s, command); 574 } 575 # ifdef LOGIN_NEEDS_UTMPX 576 else 577 do_pre_login(s); 578 # endif 579 #endif 580 581 /* Do common processing for the child, such as execing the command. */ 582 do_child(s, command); 583 /* NOTREACHED */ 584 } 585 #ifdef _UNICOS 586 signal(WJSIGNAL, cray_job_termination_handler); 587 #endif /* _UNICOS */ 588 #ifdef HAVE_CYGWIN 589 if (is_winnt) 590 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); 591 #endif 592 if (pid < 0) 593 packet_disconnect("fork failed: %.100s", strerror(errno)); 594 s->pid = pid; 595 596 /* Parent. Close the slave side of the pseudo tty. */ 597 close(ttyfd); 598 599 /* 600 * Create another descriptor of the pty master side for use as the 601 * standard input. We could use the original descriptor, but this 602 * simplifies code in server_loop. The descriptor is bidirectional. 603 */ 604 fdout = dup(ptyfd); 605 if (fdout < 0) 606 packet_disconnect("dup #1 failed: %.100s", strerror(errno)); 607 608 /* we keep a reference to the pty master */ 609 ptymaster = dup(ptyfd); 610 if (ptymaster < 0) 611 packet_disconnect("dup #2 failed: %.100s", strerror(errno)); 612 s->ptymaster = ptymaster; 613 614 /* Enter interactive session. */ 615 packet_set_interactive(1); 616 if (compat20) { 617 session_set_fds(s, ptyfd, fdout, -1); 618 } else { 619 server_loop(pid, ptyfd, fdout, -1); 620 /* server_loop _has_ closed ptyfd and fdout. */ 621 } 622 } 623 624 #ifdef LOGIN_NEEDS_UTMPX 625 static void 626 do_pre_login(Session *s) 627 { 628 socklen_t fromlen; 629 struct sockaddr_storage from; 630 pid_t pid = getpid(); 631 632 /* 633 * Get IP address of client. If the connection is not a socket, let 634 * the address be 0.0.0.0. 635 */ 636 memset(&from, 0, sizeof(from)); 637 fromlen = sizeof(from); 638 if (packet_connection_is_on_socket()) { 639 if (getpeername(packet_get_connection_in(), 640 (struct sockaddr *) & from, &fromlen) < 0) { 641 debug("getpeername: %.100s", strerror(errno)); 642 cleanup_exit(255); 643 } 644 } 645 646 record_utmp_only(pid, s->tty, s->pw->pw_name, 647 get_remote_name_or_ip(utmp_len, options.use_dns), 648 (struct sockaddr *)&from, fromlen); 649 } 650 #endif 651 652 /* 653 * This is called to fork and execute a command. If another command is 654 * to be forced, execute that instead. 655 */ 656 void 657 do_exec(Session *s, const char *command) 658 { 659 if (forced_command) { 660 original_command = command; 661 command = forced_command; 662 debug("Forced command '%.900s'", command); 663 } 664 665 #ifdef GSSAPI 666 if (options.gss_authentication) { 667 temporarily_use_uid(s->pw); 668 ssh_gssapi_storecreds(); 669 restore_uid(); 670 } 671 #endif 672 673 if (s->ttyfd != -1) 674 do_exec_pty(s, command); 675 else 676 do_exec_no_pty(s, command); 677 678 original_command = NULL; 679 680 /* 681 * Clear loginmsg: it's the child's responsibility to display 682 * it to the user, otherwise multiple sessions may accumulate 683 * multiple copies of the login messages. 684 */ 685 buffer_clear(&loginmsg); 686 } 687 688 /* administrative, login(1)-like work */ 689 void 690 do_login(Session *s, const char *command) 691 { 692 socklen_t fromlen; 693 struct sockaddr_storage from; 694 struct passwd * pw = s->pw; 695 pid_t pid = getpid(); 696 697 /* 698 * Get IP address of client. If the connection is not a socket, let 699 * the address be 0.0.0.0. 700 */ 701 memset(&from, 0, sizeof(from)); 702 fromlen = sizeof(from); 703 if (packet_connection_is_on_socket()) { 704 if (getpeername(packet_get_connection_in(), 705 (struct sockaddr *) & from, &fromlen) < 0) { 706 debug("getpeername: %.100s", strerror(errno)); 707 cleanup_exit(255); 708 } 709 } 710 711 /* Record that there was a login on that tty from the remote host. */ 712 if (!use_privsep) 713 record_login(pid, s->tty, pw->pw_name, pw->pw_uid, 714 get_remote_name_or_ip(utmp_len, 715 options.use_dns), 716 (struct sockaddr *)&from, fromlen); 717 718 #ifdef USE_PAM 719 /* 720 * If password change is needed, do it now. 721 * This needs to occur before the ~/.hushlogin check. 722 */ 723 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) { 724 display_loginmsg(); 725 do_pam_chauthtok(); 726 s->authctxt->force_pwchange = 0; 727 /* XXX - signal [net] parent to enable forwardings */ 728 } 729 #endif 730 731 if (check_quietlogin(s, command)) 732 return; 733 734 display_loginmsg(); 735 736 do_motd(); 737 } 738 739 /* 740 * Display the message of the day. 741 */ 742 void 743 do_motd(void) 744 { 745 FILE *f; 746 char buf[256]; 747 #ifdef HAVE_LOGIN_CAP 748 const char *fname; 749 #endif 750 751 #ifdef HAVE_LOGIN_CAP 752 fname = login_getcapstr(lc, "copyright", NULL, NULL); 753 if (fname != NULL && (f = fopen(fname, "r")) != NULL) { 754 while (fgets(buf, sizeof(buf), f) != NULL) 755 fputs(buf, stdout); 756 fclose(f); 757 } else 758 #endif /* HAVE_LOGIN_CAP */ 759 (void)printf("%s\n\t%s %s\n", 760 "Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994", 761 "The Regents of the University of California. ", 762 "All rights reserved."); 763 764 (void)printf("\n"); 765 766 if (options.print_motd) { 767 #ifdef HAVE_LOGIN_CAP 768 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd", 769 "/etc/motd"), "r"); 770 #else 771 f = fopen("/etc/motd", "r"); 772 #endif 773 if (f) { 774 while (fgets(buf, sizeof(buf), f)) 775 fputs(buf, stdout); 776 fclose(f); 777 } 778 } 779 } 780 781 782 /* 783 * Check for quiet login, either .hushlogin or command given. 784 */ 785 int 786 check_quietlogin(Session *s, const char *command) 787 { 788 char buf[256]; 789 struct passwd *pw = s->pw; 790 struct stat st; 791 792 /* Return 1 if .hushlogin exists or a command given. */ 793 if (command != NULL) 794 return 1; 795 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); 796 #ifdef HAVE_LOGIN_CAP 797 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) 798 return 1; 799 #else 800 if (stat(buf, &st) >= 0) 801 return 1; 802 #endif 803 return 0; 804 } 805 806 /* 807 * Sets the value of the given variable in the environment. If the variable 808 * already exists, its value is overriden. 809 */ 810 void 811 child_set_env(char ***envp, u_int *envsizep, const char *name, 812 const char *value) 813 { 814 char **env; 815 u_int envsize; 816 u_int i, namelen; 817 818 /* 819 * If we're passed an uninitialized list, allocate a single null 820 * entry before continuing. 821 */ 822 if (*envp == NULL && *envsizep == 0) { 823 *envp = xmalloc(sizeof(char *)); 824 *envp[0] = NULL; 825 *envsizep = 1; 826 } 827 828 /* 829 * Find the slot where the value should be stored. If the variable 830 * already exists, we reuse the slot; otherwise we append a new slot 831 * at the end of the array, expanding if necessary. 832 */ 833 env = *envp; 834 namelen = strlen(name); 835 for (i = 0; env[i]; i++) 836 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 837 break; 838 if (env[i]) { 839 /* Reuse the slot. */ 840 xfree(env[i]); 841 } else { 842 /* New variable. Expand if necessary. */ 843 envsize = *envsizep; 844 if (i >= envsize - 1) { 845 if (envsize >= 1000) 846 fatal("child_set_env: too many env vars"); 847 envsize += 50; 848 env = (*envp) = xrealloc(env, envsize * sizeof(char *)); 849 *envsizep = envsize; 850 } 851 /* Need to set the NULL pointer at end of array beyond the new slot. */ 852 env[i + 1] = NULL; 853 } 854 855 /* Allocate space and format the variable in the appropriate slot. */ 856 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 857 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 858 } 859 860 /* 861 * Reads environment variables from the given file and adds/overrides them 862 * into the environment. If the file does not exist, this does nothing. 863 * Otherwise, it must consist of empty lines, comments (line starts with '#') 864 * and assignments of the form name=value. No other forms are allowed. 865 */ 866 static void 867 read_environment_file(char ***env, u_int *envsize, 868 const char *filename) 869 { 870 FILE *f; 871 char buf[4096]; 872 char *cp, *value; 873 u_int lineno = 0; 874 875 f = fopen(filename, "r"); 876 if (!f) 877 return; 878 879 while (fgets(buf, sizeof(buf), f)) { 880 if (++lineno > 1000) 881 fatal("Too many lines in environment file %s", filename); 882 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) 883 ; 884 if (!*cp || *cp == '#' || *cp == '\n') 885 continue; 886 if (strchr(cp, '\n')) 887 *strchr(cp, '\n') = '\0'; 888 value = strchr(cp, '='); 889 if (value == NULL) { 890 fprintf(stderr, "Bad line %u in %.100s\n", lineno, 891 filename); 892 continue; 893 } 894 /* 895 * Replace the equals sign by nul, and advance value to 896 * the value string. 897 */ 898 *value = '\0'; 899 value++; 900 child_set_env(env, envsize, cp, value); 901 } 902 fclose(f); 903 } 904 905 #ifdef HAVE_ETC_DEFAULT_LOGIN 906 /* 907 * Return named variable from specified environment, or NULL if not present. 908 */ 909 static char * 910 child_get_env(char **env, const char *name) 911 { 912 int i; 913 size_t len; 914 915 len = strlen(name); 916 for (i=0; env[i] != NULL; i++) 917 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=') 918 return(env[i] + len + 1); 919 return NULL; 920 } 921 922 /* 923 * Read /etc/default/login. 924 * We pick up the PATH (or SUPATH for root) and UMASK. 925 */ 926 static void 927 read_etc_default_login(char ***env, u_int *envsize, uid_t uid) 928 { 929 char **tmpenv = NULL, *var; 930 u_int i, tmpenvsize = 0; 931 u_long mask; 932 933 /* 934 * We don't want to copy the whole file to the child's environment, 935 * so we use a temporary environment and copy the variables we're 936 * interested in. 937 */ 938 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login"); 939 940 if (tmpenv == NULL) 941 return; 942 943 if (uid == 0) 944 var = child_get_env(tmpenv, "SUPATH"); 945 else 946 var = child_get_env(tmpenv, "PATH"); 947 if (var != NULL) 948 child_set_env(env, envsize, "PATH", var); 949 950 if ((var = child_get_env(tmpenv, "UMASK")) != NULL) 951 if (sscanf(var, "%5lo", &mask) == 1) 952 umask((mode_t)mask); 953 954 for (i = 0; tmpenv[i] != NULL; i++) 955 xfree(tmpenv[i]); 956 xfree(tmpenv); 957 } 958 #endif /* HAVE_ETC_DEFAULT_LOGIN */ 959 960 void copy_environment(char **source, char ***env, u_int *envsize) 961 { 962 char *var_name, *var_val; 963 int i; 964 965 if (source == NULL) 966 return; 967 968 for(i = 0; source[i] != NULL; i++) { 969 var_name = xstrdup(source[i]); 970 if ((var_val = strstr(var_name, "=")) == NULL) { 971 xfree(var_name); 972 continue; 973 } 974 *var_val++ = '\0'; 975 976 debug3("Copy environment: %s=%s", var_name, var_val); 977 child_set_env(env, envsize, var_name, var_val); 978 979 xfree(var_name); 980 } 981 } 982 983 static char ** 984 do_setup_env(Session *s, const char *shell) 985 { 986 char buf[256]; 987 u_int i, envsize; 988 char **env, *laddr, *path = NULL; 989 #ifdef HAVE_LOGIN_CAP 990 extern char **environ; 991 char **senv, **var; 992 #endif 993 struct passwd *pw = s->pw; 994 995 /* Initialize the environment. */ 996 envsize = 100; 997 env = xmalloc(envsize * sizeof(char *)); 998 env[0] = NULL; 999 1000 #ifdef HAVE_CYGWIN 1001 /* 1002 * The Windows environment contains some setting which are 1003 * important for a running system. They must not be dropped. 1004 */ 1005 copy_environment(environ, &env, &envsize); 1006 #endif 1007 1008 if (getenv("TZ")) 1009 child_set_env(&env, &envsize, "TZ", getenv("TZ")); 1010 1011 #ifdef GSSAPI 1012 /* Allow any GSSAPI methods that we've used to alter 1013 * the childs environment as they see fit 1014 */ 1015 ssh_gssapi_do_child(&env, &envsize); 1016 #endif 1017 1018 if (!options.use_login) { 1019 /* Set basic environment. */ 1020 for (i = 0; i < s->num_env; i++) 1021 child_set_env(&env, &envsize, s->env[i].name, 1022 s->env[i].val); 1023 1024 child_set_env(&env, &envsize, "USER", pw->pw_name); 1025 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); 1026 #ifdef _AIX 1027 child_set_env(&env, &envsize, "LOGIN", pw->pw_name); 1028 #endif 1029 child_set_env(&env, &envsize, "HOME", pw->pw_dir); 1030 snprintf(buf, sizeof buf, "%.200s/%.50s", 1031 _PATH_MAILDIR, pw->pw_name); 1032 child_set_env(&env, &envsize, "MAIL", buf); 1033 #ifdef HAVE_LOGIN_CAP 1034 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); 1035 child_set_env(&env, &envsize, "TERM", "su"); 1036 senv = environ; 1037 environ = xmalloc(sizeof(char *)); 1038 *environ = NULL; 1039 (void) setusercontext(lc, pw, pw->pw_uid, 1040 LOGIN_SETENV|LOGIN_SETPATH); 1041 copy_environment(environ, &env, &envsize); 1042 for (var = environ; *var != NULL; ++var) 1043 xfree(*var); 1044 xfree(environ); 1045 environ = senv; 1046 #else /* HAVE_LOGIN_CAP */ 1047 # ifndef HAVE_CYGWIN 1048 /* 1049 * There's no standard path on Windows. The path contains 1050 * important components pointing to the system directories, 1051 * needed for loading shared libraries. So the path better 1052 * remains intact here. 1053 */ 1054 # ifdef HAVE_ETC_DEFAULT_LOGIN 1055 read_etc_default_login(&env, &envsize, pw->pw_uid); 1056 path = child_get_env(env, "PATH"); 1057 # endif /* HAVE_ETC_DEFAULT_LOGIN */ 1058 if (path == NULL || *path == '\0') { 1059 child_set_env(&env, &envsize, "PATH", 1060 s->pw->pw_uid == 0 ? 1061 SUPERUSER_PATH : _PATH_STDPATH); 1062 } 1063 # endif /* HAVE_CYGWIN */ 1064 #endif /* HAVE_LOGIN_CAP */ 1065 1066 /* Normal systems set SHELL by default. */ 1067 child_set_env(&env, &envsize, "SHELL", shell); 1068 } 1069 1070 /* Set custom environment options from RSA authentication. */ 1071 if (!options.use_login) { 1072 while (custom_environment) { 1073 struct envstring *ce = custom_environment; 1074 char *str = ce->s; 1075 1076 for (i = 0; str[i] != '=' && str[i]; i++) 1077 ; 1078 if (str[i] == '=') { 1079 str[i] = 0; 1080 child_set_env(&env, &envsize, str, str + i + 1); 1081 } 1082 custom_environment = ce->next; 1083 xfree(ce->s); 1084 xfree(ce); 1085 } 1086 } 1087 1088 /* SSH_CLIENT deprecated */ 1089 snprintf(buf, sizeof buf, "%.50s %d %d", 1090 get_remote_ipaddr(), get_remote_port(), get_local_port()); 1091 child_set_env(&env, &envsize, "SSH_CLIENT", buf); 1092 1093 laddr = get_local_ipaddr(packet_get_connection_in()); 1094 snprintf(buf, sizeof buf, "%.50s %d %.50s %d", 1095 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port()); 1096 xfree(laddr); 1097 child_set_env(&env, &envsize, "SSH_CONNECTION", buf); 1098 1099 if (s->ttyfd != -1) 1100 child_set_env(&env, &envsize, "SSH_TTY", s->tty); 1101 if (s->term) 1102 child_set_env(&env, &envsize, "TERM", s->term); 1103 if (s->display) 1104 child_set_env(&env, &envsize, "DISPLAY", s->display); 1105 if (original_command) 1106 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", 1107 original_command); 1108 1109 #ifdef _UNICOS 1110 if (cray_tmpdir[0] != '\0') 1111 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir); 1112 #endif /* _UNICOS */ 1113 1114 #ifdef _AIX 1115 { 1116 char *cp; 1117 1118 if ((cp = getenv("AUTHSTATE")) != NULL) 1119 child_set_env(&env, &envsize, "AUTHSTATE", cp); 1120 if ((cp = getenv("KRB5CCNAME")) != NULL) 1121 child_set_env(&env, &envsize, "KRB5CCNAME", cp); 1122 read_environment_file(&env, &envsize, "/etc/environment"); 1123 } 1124 #endif 1125 #ifdef KRB5 1126 if (s->authctxt->krb5_ccname) 1127 child_set_env(&env, &envsize, "KRB5CCNAME", 1128 s->authctxt->krb5_ccname); 1129 #endif 1130 #ifdef USE_PAM 1131 /* 1132 * Pull in any environment variables that may have 1133 * been set by PAM. 1134 */ 1135 if (options.use_pam) { 1136 char **p; 1137 1138 p = fetch_pam_child_environment(); 1139 copy_environment(p, &env, &envsize); 1140 free_pam_environment(p); 1141 1142 p = fetch_pam_environment(); 1143 copy_environment(p, &env, &envsize); 1144 free_pam_environment(p); 1145 } 1146 #endif /* USE_PAM */ 1147 1148 if (auth_sock_name != NULL) 1149 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, 1150 auth_sock_name); 1151 1152 /* read $HOME/.ssh/environment. */ 1153 if (options.permit_user_env && !options.use_login) { 1154 snprintf(buf, sizeof buf, "%.200s/.ssh/environment", 1155 strcmp(pw->pw_dir, "/") ? pw->pw_dir : ""); 1156 read_environment_file(&env, &envsize, buf); 1157 } 1158 if (debug_flag) { 1159 /* dump the environment */ 1160 fprintf(stderr, "Environment:\n"); 1161 for (i = 0; env[i]; i++) 1162 fprintf(stderr, " %.200s\n", env[i]); 1163 } 1164 return env; 1165 } 1166 1167 /* 1168 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found 1169 * first in this order). 1170 */ 1171 static void 1172 do_rc_files(Session *s, const char *shell) 1173 { 1174 FILE *f = NULL; 1175 char cmd[1024]; 1176 int do_xauth; 1177 struct stat st; 1178 1179 do_xauth = 1180 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; 1181 1182 /* ignore _PATH_SSH_USER_RC for subsystems */ 1183 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) { 1184 snprintf(cmd, sizeof cmd, "%s -c '%s %s'", 1185 shell, _PATH_BSHELL, _PATH_SSH_USER_RC); 1186 if (debug_flag) 1187 fprintf(stderr, "Running %s\n", cmd); 1188 f = popen(cmd, "w"); 1189 if (f) { 1190 if (do_xauth) 1191 fprintf(f, "%s %s\n", s->auth_proto, 1192 s->auth_data); 1193 pclose(f); 1194 } else 1195 fprintf(stderr, "Could not run %s\n", 1196 _PATH_SSH_USER_RC); 1197 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { 1198 if (debug_flag) 1199 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, 1200 _PATH_SSH_SYSTEM_RC); 1201 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); 1202 if (f) { 1203 if (do_xauth) 1204 fprintf(f, "%s %s\n", s->auth_proto, 1205 s->auth_data); 1206 pclose(f); 1207 } else 1208 fprintf(stderr, "Could not run %s\n", 1209 _PATH_SSH_SYSTEM_RC); 1210 } else if (do_xauth && options.xauth_location != NULL) { 1211 /* Add authority data to .Xauthority if appropriate. */ 1212 if (debug_flag) { 1213 fprintf(stderr, 1214 "Running %.500s remove %.100s\n", 1215 options.xauth_location, s->auth_display); 1216 fprintf(stderr, 1217 "%.500s add %.100s %.100s %.100s\n", 1218 options.xauth_location, s->auth_display, 1219 s->auth_proto, s->auth_data); 1220 } 1221 snprintf(cmd, sizeof cmd, "%s -q -", 1222 options.xauth_location); 1223 f = popen(cmd, "w"); 1224 if (f) { 1225 fprintf(f, "remove %s\n", 1226 s->auth_display); 1227 fprintf(f, "add %s %s %s\n", 1228 s->auth_display, s->auth_proto, 1229 s->auth_data); 1230 pclose(f); 1231 } else { 1232 fprintf(stderr, "Could not run %s\n", 1233 cmd); 1234 } 1235 } 1236 } 1237 1238 static void 1239 do_nologin(struct passwd *pw) 1240 { 1241 FILE *f = NULL; 1242 char buf[1024]; 1243 1244 #ifdef HAVE_LOGIN_CAP 1245 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) 1246 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, 1247 _PATH_NOLOGIN), "r"); 1248 #else 1249 if (pw->pw_uid) 1250 f = fopen(_PATH_NOLOGIN, "r"); 1251 #endif 1252 if (f) { 1253 /* /etc/nologin exists. Print its contents and exit. */ 1254 logit("User %.100s not allowed because %s exists", 1255 pw->pw_name, _PATH_NOLOGIN); 1256 while (fgets(buf, sizeof(buf), f)) 1257 fputs(buf, stderr); 1258 fclose(f); 1259 fflush(NULL); 1260 exit(254); 1261 } 1262 } 1263 1264 /* Set login name, uid, gid, and groups. */ 1265 void 1266 do_setusercontext(struct passwd *pw) 1267 { 1268 #ifndef HAVE_CYGWIN 1269 if (getuid() == 0 || geteuid() == 0) 1270 #endif /* HAVE_CYGWIN */ 1271 { 1272 1273 #ifdef HAVE_SETPCRED 1274 if (setpcred(pw->pw_name, (char **)NULL) == -1) 1275 fatal("Failed to set process credentials"); 1276 #endif /* HAVE_SETPCRED */ 1277 #ifdef HAVE_LOGIN_CAP 1278 # ifdef __bsdi__ 1279 setpgid(0, 0); 1280 # endif 1281 # ifdef USE_PAM 1282 if (options.use_pam) { 1283 do_pam_session(); 1284 do_pam_setcred(0); 1285 } 1286 # endif /* USE_PAM */ 1287 if (setusercontext(lc, pw, pw->pw_uid, 1288 (LOGIN_SETALL & ~(LOGIN_SETENV|LOGIN_SETPATH))) < 0) { 1289 perror("unable to set user context"); 1290 exit(1); 1291 } 1292 #else 1293 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) 1294 /* Sets login uid for accounting */ 1295 if (getluid() == -1 && setluid(pw->pw_uid) == -1) 1296 error("setluid: %s", strerror(errno)); 1297 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */ 1298 1299 if (setlogin(pw->pw_name) < 0) 1300 error("setlogin failed: %s", strerror(errno)); 1301 if (setgid(pw->pw_gid) < 0) { 1302 perror("setgid"); 1303 exit(1); 1304 } 1305 /* Initialize the group list. */ 1306 if (initgroups(pw->pw_name, pw->pw_gid) < 0) { 1307 perror("initgroups"); 1308 exit(1); 1309 } 1310 endgrent(); 1311 # ifdef USE_PAM 1312 /* 1313 * PAM credentials may take the form of supplementary groups. 1314 * These will have been wiped by the above initgroups() call. 1315 * Reestablish them here. 1316 */ 1317 if (options.use_pam) { 1318 do_pam_session(); 1319 do_pam_setcred(0); 1320 } 1321 # endif /* USE_PAM */ 1322 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) 1323 irix_setusercontext(pw); 1324 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */ 1325 # ifdef _AIX 1326 aix_usrinfo(pw); 1327 # endif /* _AIX */ 1328 /* Permanently switch to the desired uid. */ 1329 permanently_set_uid(pw); 1330 #endif 1331 } 1332 1333 #ifdef HAVE_CYGWIN 1334 if (is_winnt) 1335 #endif 1336 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) 1337 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); 1338 } 1339 1340 static void 1341 do_pwchange(Session *s) 1342 { 1343 fflush(NULL); 1344 fprintf(stderr, "WARNING: Your password has expired.\n"); 1345 if (s->ttyfd != -1) { 1346 fprintf(stderr, 1347 "You must change your password now and login again!\n"); 1348 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL); 1349 perror("passwd"); 1350 } else { 1351 fprintf(stderr, 1352 "Password change required but no TTY available.\n"); 1353 } 1354 exit(1); 1355 } 1356 1357 static void 1358 launch_login(struct passwd *pw, const char *hostname) 1359 { 1360 /* Launch login(1). */ 1361 1362 execl(LOGIN_PROGRAM, "login", "-h", hostname, 1363 #ifdef xxxLOGIN_NEEDS_TERM 1364 (s->term ? s->term : "unknown"), 1365 #endif /* LOGIN_NEEDS_TERM */ 1366 #ifdef LOGIN_NO_ENDOPT 1367 "-p", "-f", pw->pw_name, (char *)NULL); 1368 #else 1369 "-p", "-f", "--", pw->pw_name, (char *)NULL); 1370 #endif 1371 1372 /* Login couldn't be executed, die. */ 1373 1374 perror("login"); 1375 exit(1); 1376 } 1377 1378 static void 1379 child_close_fds(void) 1380 { 1381 int i; 1382 1383 if (packet_get_connection_in() == packet_get_connection_out()) 1384 close(packet_get_connection_in()); 1385 else { 1386 close(packet_get_connection_in()); 1387 close(packet_get_connection_out()); 1388 } 1389 /* 1390 * Close all descriptors related to channels. They will still remain 1391 * open in the parent. 1392 */ 1393 /* XXX better use close-on-exec? -markus */ 1394 channel_close_all(); 1395 1396 /* 1397 * Close any extra file descriptors. Note that there may still be 1398 * descriptors left by system functions. They will be closed later. 1399 */ 1400 endpwent(); 1401 1402 /* 1403 * Close any extra open file descriptors so that we don\'t have them 1404 * hanging around in clients. Note that we want to do this after 1405 * initgroups, because at least on Solaris 2.3 it leaves file 1406 * descriptors open. 1407 */ 1408 for (i = 3; i < 64; i++) 1409 close(i); 1410 } 1411 1412 /* 1413 * Performs common processing for the child, such as setting up the 1414 * environment, closing extra file descriptors, setting the user and group 1415 * ids, and executing the command or shell. 1416 */ 1417 void 1418 do_child(Session *s, const char *command) 1419 { 1420 extern char **environ; 1421 char **env; 1422 char *argv[10]; 1423 const char *shell, *shell0, *hostname = NULL; 1424 struct passwd *pw = s->pw; 1425 #ifdef HAVE_LOGIN_CAP 1426 int lc_requirehome; 1427 #endif 1428 1429 /* remove hostkey from the child's memory */ 1430 destroy_sensitive_data(); 1431 1432 /* Force a password change */ 1433 if (s->authctxt->force_pwchange) { 1434 do_setusercontext(pw); 1435 child_close_fds(); 1436 do_pwchange(s); 1437 exit(1); 1438 } 1439 1440 /* login(1) is only called if we execute the login shell */ 1441 if (options.use_login && command != NULL) 1442 options.use_login = 0; 1443 1444 #ifdef _UNICOS 1445 cray_setup(pw->pw_uid, pw->pw_name, command); 1446 #endif /* _UNICOS */ 1447 1448 /* 1449 * Login(1) does this as well, and it needs uid 0 for the "-h" 1450 * switch, so we let login(1) to this for us. 1451 */ 1452 if (!options.use_login) { 1453 #ifdef HAVE_OSF_SIA 1454 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty); 1455 if (!check_quietlogin(s, command)) 1456 do_motd(); 1457 #else /* HAVE_OSF_SIA */ 1458 do_nologin(pw); 1459 do_setusercontext(pw); 1460 /* 1461 * PAM session modules in do_setusercontext may have 1462 * generated messages, so if this in an interactive 1463 * login then display them too. 1464 */ 1465 if (command == NULL) 1466 display_loginmsg(); 1467 #endif /* HAVE_OSF_SIA */ 1468 } 1469 1470 /* 1471 * Get the shell from the password data. An empty shell field is 1472 * legal, and means /bin/sh. 1473 */ 1474 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; 1475 1476 /* 1477 * Make sure $SHELL points to the shell from the password file, 1478 * even if shell is overridden from login.conf 1479 */ 1480 env = do_setup_env(s, shell); 1481 1482 #ifdef HAVE_LOGIN_CAP 1483 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); 1484 #endif 1485 1486 /* we have to stash the hostname before we close our socket. */ 1487 if (options.use_login) 1488 hostname = get_remote_name_or_ip(utmp_len, 1489 options.use_dns); 1490 /* 1491 * Close the connection descriptors; note that this is the child, and 1492 * the server will still have the socket open, and it is important 1493 * that we do not shutdown it. Note that the descriptors cannot be 1494 * closed before building the environment, as we call 1495 * get_remote_ipaddr there. 1496 */ 1497 child_close_fds(); 1498 1499 /* 1500 * Must take new environment into use so that .ssh/rc, 1501 * /etc/ssh/sshrc and xauth are run in the proper environment. 1502 */ 1503 environ = env; 1504 1505 #ifdef HAVE_LOGIN_CAP 1506 lc_requirehome = login_getcapbool(lc, "requirehome", 0); 1507 login_close(lc); 1508 #endif 1509 #if defined(KRB5) && defined(USE_AFS) 1510 /* 1511 * At this point, we check to see if AFS is active and if we have 1512 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see 1513 * if we can (and need to) extend the ticket into an AFS token. If 1514 * we don't do this, we run into potential problems if the user's 1515 * home directory is in AFS and it's not world-readable. 1516 */ 1517 1518 if (options.kerberos_get_afs_token && k_hasafs() && 1519 (s->authctxt->krb5_ctx != NULL)) { 1520 char cell[64]; 1521 1522 debug("Getting AFS token"); 1523 1524 k_setpag(); 1525 1526 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) 1527 krb5_afslog(s->authctxt->krb5_ctx, 1528 s->authctxt->krb5_fwd_ccache, cell, NULL); 1529 1530 krb5_afslog_home(s->authctxt->krb5_ctx, 1531 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir); 1532 } 1533 #endif 1534 1535 /* Change current directory to the user\'s home directory. */ 1536 if (chdir(pw->pw_dir) < 0) { 1537 fprintf(stderr, "Could not chdir to home directory %s: %s\n", 1538 pw->pw_dir, strerror(errno)); 1539 #ifdef HAVE_LOGIN_CAP 1540 if (lc_requirehome) 1541 exit(1); 1542 #endif 1543 } 1544 1545 if (!options.use_login) 1546 do_rc_files(s, shell); 1547 1548 /* restore SIGPIPE for child */ 1549 signal(SIGPIPE, SIG_DFL); 1550 1551 if (options.use_login) { 1552 launch_login(pw, hostname); 1553 /* NEVERREACHED */ 1554 } 1555 1556 /* Get the last component of the shell name. */ 1557 if ((shell0 = strrchr(shell, '/')) != NULL) 1558 shell0++; 1559 else 1560 shell0 = shell; 1561 1562 /* 1563 * If we have no command, execute the shell. In this case, the shell 1564 * name to be passed in argv[0] is preceded by '-' to indicate that 1565 * this is a login shell. 1566 */ 1567 if (!command) { 1568 char argv0[256]; 1569 1570 /* Start the shell. Set initial character to '-'. */ 1571 argv0[0] = '-'; 1572 1573 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1) 1574 >= sizeof(argv0) - 1) { 1575 errno = EINVAL; 1576 perror(shell); 1577 exit(1); 1578 } 1579 1580 /* Execute the shell. */ 1581 argv[0] = argv0; 1582 argv[1] = NULL; 1583 execve(shell, argv, env); 1584 1585 /* Executing the shell failed. */ 1586 perror(shell); 1587 exit(1); 1588 } 1589 /* 1590 * Execute the command using the user's shell. This uses the -c 1591 * option to execute the command. 1592 */ 1593 argv[0] = (char *) shell0; 1594 argv[1] = "-c"; 1595 argv[2] = (char *) command; 1596 argv[3] = NULL; 1597 execve(shell, argv, env); 1598 perror(shell); 1599 exit(1); 1600 } 1601 1602 Session * 1603 session_new(void) 1604 { 1605 int i; 1606 static int did_init = 0; 1607 if (!did_init) { 1608 debug("session_new: init"); 1609 for (i = 0; i < MAX_SESSIONS; i++) { 1610 sessions[i].used = 0; 1611 } 1612 did_init = 1; 1613 } 1614 for (i = 0; i < MAX_SESSIONS; i++) { 1615 Session *s = &sessions[i]; 1616 if (! s->used) { 1617 memset(s, 0, sizeof(*s)); 1618 s->chanid = -1; 1619 s->ptyfd = -1; 1620 s->ttyfd = -1; 1621 s->used = 1; 1622 s->self = i; 1623 debug("session_new: session %d", i); 1624 return s; 1625 } 1626 } 1627 return NULL; 1628 } 1629 1630 static void 1631 session_dump(void) 1632 { 1633 int i; 1634 for (i = 0; i < MAX_SESSIONS; i++) { 1635 Session *s = &sessions[i]; 1636 debug("dump: used %d session %d %p channel %d pid %ld", 1637 s->used, 1638 s->self, 1639 s, 1640 s->chanid, 1641 (long)s->pid); 1642 } 1643 } 1644 1645 int 1646 session_open(Authctxt *authctxt, int chanid) 1647 { 1648 Session *s = session_new(); 1649 debug("session_open: channel %d", chanid); 1650 if (s == NULL) { 1651 error("no more sessions"); 1652 return 0; 1653 } 1654 s->authctxt = authctxt; 1655 s->pw = authctxt->pw; 1656 if (s->pw == NULL || !authctxt->valid) 1657 fatal("no user for session %d", s->self); 1658 debug("session_open: session %d: link with channel %d", s->self, chanid); 1659 s->chanid = chanid; 1660 return 1; 1661 } 1662 1663 Session * 1664 session_by_tty(char *tty) 1665 { 1666 int i; 1667 for (i = 0; i < MAX_SESSIONS; i++) { 1668 Session *s = &sessions[i]; 1669 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) { 1670 debug("session_by_tty: session %d tty %s", i, tty); 1671 return s; 1672 } 1673 } 1674 debug("session_by_tty: unknown tty %.100s", tty); 1675 session_dump(); 1676 return NULL; 1677 } 1678 1679 static Session * 1680 session_by_channel(int id) 1681 { 1682 int i; 1683 for (i = 0; i < MAX_SESSIONS; i++) { 1684 Session *s = &sessions[i]; 1685 if (s->used && s->chanid == id) { 1686 debug("session_by_channel: session %d channel %d", i, id); 1687 return s; 1688 } 1689 } 1690 debug("session_by_channel: unknown channel %d", id); 1691 session_dump(); 1692 return NULL; 1693 } 1694 1695 static Session * 1696 session_by_pid(pid_t pid) 1697 { 1698 int i; 1699 debug("session_by_pid: pid %ld", (long)pid); 1700 for (i = 0; i < MAX_SESSIONS; i++) { 1701 Session *s = &sessions[i]; 1702 if (s->used && s->pid == pid) 1703 return s; 1704 } 1705 error("session_by_pid: unknown pid %ld", (long)pid); 1706 session_dump(); 1707 return NULL; 1708 } 1709 1710 static int 1711 session_window_change_req(Session *s) 1712 { 1713 s->col = packet_get_int(); 1714 s->row = packet_get_int(); 1715 s->xpixel = packet_get_int(); 1716 s->ypixel = packet_get_int(); 1717 packet_check_eom(); 1718 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); 1719 return 1; 1720 } 1721 1722 static int 1723 session_pty_req(Session *s) 1724 { 1725 u_int len; 1726 int n_bytes; 1727 1728 if (no_pty_flag) { 1729 debug("Allocating a pty not permitted for this authentication."); 1730 return 0; 1731 } 1732 if (s->ttyfd != -1) { 1733 packet_disconnect("Protocol error: you already have a pty."); 1734 return 0; 1735 } 1736 1737 s->term = packet_get_string(&len); 1738 1739 if (compat20) { 1740 s->col = packet_get_int(); 1741 s->row = packet_get_int(); 1742 } else { 1743 s->row = packet_get_int(); 1744 s->col = packet_get_int(); 1745 } 1746 s->xpixel = packet_get_int(); 1747 s->ypixel = packet_get_int(); 1748 1749 if (strcmp(s->term, "") == 0) { 1750 xfree(s->term); 1751 s->term = NULL; 1752 } 1753 1754 /* Allocate a pty and open it. */ 1755 debug("Allocating pty."); 1756 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) { 1757 if (s->term) 1758 xfree(s->term); 1759 s->term = NULL; 1760 s->ptyfd = -1; 1761 s->ttyfd = -1; 1762 error("session_pty_req: session %d alloc failed", s->self); 1763 return 0; 1764 } 1765 debug("session_pty_req: session %d alloc %s", s->self, s->tty); 1766 1767 /* for SSH1 the tty modes length is not given */ 1768 if (!compat20) 1769 n_bytes = packet_remaining(); 1770 tty_parse_modes(s->ttyfd, &n_bytes); 1771 1772 if (!use_privsep) 1773 pty_setowner(s->pw, s->tty); 1774 1775 /* Set window size from the packet. */ 1776 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); 1777 1778 packet_check_eom(); 1779 session_proctitle(s); 1780 return 1; 1781 } 1782 1783 static int 1784 session_subsystem_req(Session *s) 1785 { 1786 struct stat st; 1787 u_int len; 1788 int success = 0; 1789 char *cmd, *subsys = packet_get_string(&len); 1790 int i; 1791 1792 packet_check_eom(); 1793 logit("subsystem request for %.100s", subsys); 1794 1795 for (i = 0; i < options.num_subsystems; i++) { 1796 if (strcmp(subsys, options.subsystem_name[i]) == 0) { 1797 cmd = options.subsystem_command[i]; 1798 if (stat(cmd, &st) < 0) { 1799 error("subsystem: cannot stat %s: %s", cmd, 1800 strerror(errno)); 1801 break; 1802 } 1803 debug("subsystem: exec() %s", cmd); 1804 s->is_subsystem = 1; 1805 do_exec(s, cmd); 1806 success = 1; 1807 break; 1808 } 1809 } 1810 1811 if (!success) 1812 logit("subsystem request for %.100s failed, subsystem not found", 1813 subsys); 1814 1815 xfree(subsys); 1816 return success; 1817 } 1818 1819 static int 1820 session_x11_req(Session *s) 1821 { 1822 int success; 1823 1824 s->single_connection = packet_get_char(); 1825 s->auth_proto = packet_get_string(NULL); 1826 s->auth_data = packet_get_string(NULL); 1827 s->screen = packet_get_int(); 1828 packet_check_eom(); 1829 1830 success = session_setup_x11fwd(s); 1831 if (!success) { 1832 xfree(s->auth_proto); 1833 xfree(s->auth_data); 1834 s->auth_proto = NULL; 1835 s->auth_data = NULL; 1836 } 1837 return success; 1838 } 1839 1840 static int 1841 session_shell_req(Session *s) 1842 { 1843 packet_check_eom(); 1844 do_exec(s, NULL); 1845 return 1; 1846 } 1847 1848 static int 1849 session_exec_req(Session *s) 1850 { 1851 u_int len; 1852 char *command = packet_get_string(&len); 1853 packet_check_eom(); 1854 do_exec(s, command); 1855 xfree(command); 1856 return 1; 1857 } 1858 1859 static int 1860 session_break_req(Session *s) 1861 { 1862 1863 packet_get_int(); /* ignored */ 1864 packet_check_eom(); 1865 1866 if (s->ttyfd == -1 || 1867 tcsendbreak(s->ttyfd, 0) < 0) 1868 return 0; 1869 return 1; 1870 } 1871 1872 static int 1873 session_env_req(Session *s) 1874 { 1875 char *name, *val; 1876 u_int name_len, val_len, i; 1877 1878 name = packet_get_string(&name_len); 1879 val = packet_get_string(&val_len); 1880 packet_check_eom(); 1881 1882 /* Don't set too many environment variables */ 1883 if (s->num_env > 128) { 1884 debug2("Ignoring env request %s: too many env vars", name); 1885 goto fail; 1886 } 1887 1888 for (i = 0; i < options.num_accept_env; i++) { 1889 if (match_pattern(name, options.accept_env[i])) { 1890 debug2("Setting env %d: %s=%s", s->num_env, name, val); 1891 s->env = xrealloc(s->env, sizeof(*s->env) * 1892 (s->num_env + 1)); 1893 s->env[s->num_env].name = name; 1894 s->env[s->num_env].val = val; 1895 s->num_env++; 1896 return (1); 1897 } 1898 } 1899 debug2("Ignoring env request %s: disallowed name", name); 1900 1901 fail: 1902 xfree(name); 1903 xfree(val); 1904 return (0); 1905 } 1906 1907 static int 1908 session_auth_agent_req(Session *s) 1909 { 1910 static int called = 0; 1911 packet_check_eom(); 1912 if (no_agent_forwarding_flag) { 1913 debug("session_auth_agent_req: no_agent_forwarding_flag"); 1914 return 0; 1915 } 1916 if (called) { 1917 return 0; 1918 } else { 1919 called = 1; 1920 return auth_input_request_forwarding(s->pw); 1921 } 1922 } 1923 1924 int 1925 session_input_channel_req(Channel *c, const char *rtype) 1926 { 1927 int success = 0; 1928 Session *s; 1929 1930 if ((s = session_by_channel(c->self)) == NULL) { 1931 logit("session_input_channel_req: no session %d req %.100s", 1932 c->self, rtype); 1933 return 0; 1934 } 1935 debug("session_input_channel_req: session %d req %s", s->self, rtype); 1936 1937 /* 1938 * a session is in LARVAL state until a shell, a command 1939 * or a subsystem is executed 1940 */ 1941 if (c->type == SSH_CHANNEL_LARVAL) { 1942 if (strcmp(rtype, "shell") == 0) { 1943 success = session_shell_req(s); 1944 } else if (strcmp(rtype, "exec") == 0) { 1945 success = session_exec_req(s); 1946 } else if (strcmp(rtype, "pty-req") == 0) { 1947 success = session_pty_req(s); 1948 } else if (strcmp(rtype, "x11-req") == 0) { 1949 success = session_x11_req(s); 1950 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { 1951 success = session_auth_agent_req(s); 1952 } else if (strcmp(rtype, "subsystem") == 0) { 1953 success = session_subsystem_req(s); 1954 } else if (strcmp(rtype, "env") == 0) { 1955 success = session_env_req(s); 1956 } 1957 } 1958 if (strcmp(rtype, "window-change") == 0) { 1959 success = session_window_change_req(s); 1960 } else if (strcmp(rtype, "break") == 0) { 1961 success = session_break_req(s); 1962 } 1963 1964 return success; 1965 } 1966 1967 void 1968 session_set_fds(Session *s, int fdin, int fdout, int fderr) 1969 { 1970 if (!compat20) 1971 fatal("session_set_fds: called for proto != 2.0"); 1972 /* 1973 * now that have a child and a pipe to the child, 1974 * we can activate our channel and register the fd's 1975 */ 1976 if (s->chanid == -1) 1977 fatal("no channel for session %d", s->self); 1978 channel_set_fds(s->chanid, 1979 fdout, fdin, fderr, 1980 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, 1981 1, 1982 CHAN_SES_WINDOW_DEFAULT); 1983 } 1984 1985 /* 1986 * Function to perform pty cleanup. Also called if we get aborted abnormally 1987 * (e.g., due to a dropped connection). 1988 */ 1989 void 1990 session_pty_cleanup2(Session *s) 1991 { 1992 if (s == NULL) { 1993 error("session_pty_cleanup: no session"); 1994 return; 1995 } 1996 if (s->ttyfd == -1) 1997 return; 1998 1999 debug("session_pty_cleanup: session %d release %s", s->self, s->tty); 2000 2001 /* Record that the user has logged out. */ 2002 if (s->pid != 0) 2003 record_logout(s->pid, s->tty, s->pw->pw_name); 2004 2005 /* Release the pseudo-tty. */ 2006 if (getuid() == 0) 2007 pty_release(s->tty); 2008 2009 /* 2010 * Close the server side of the socket pairs. We must do this after 2011 * the pty cleanup, so that another process doesn't get this pty 2012 * while we're still cleaning up. 2013 */ 2014 if (close(s->ptymaster) < 0) 2015 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno)); 2016 2017 /* unlink pty from session */ 2018 s->ttyfd = -1; 2019 } 2020 2021 void 2022 session_pty_cleanup(Session *s) 2023 { 2024 PRIVSEP(session_pty_cleanup2(s)); 2025 } 2026 2027 static char * 2028 sig2name(int sig) 2029 { 2030 #define SSH_SIG(x) if (sig == SIG ## x) return #x 2031 SSH_SIG(ABRT); 2032 SSH_SIG(ALRM); 2033 SSH_SIG(FPE); 2034 SSH_SIG(HUP); 2035 SSH_SIG(ILL); 2036 SSH_SIG(INT); 2037 SSH_SIG(KILL); 2038 SSH_SIG(PIPE); 2039 SSH_SIG(QUIT); 2040 SSH_SIG(SEGV); 2041 SSH_SIG(TERM); 2042 SSH_SIG(USR1); 2043 SSH_SIG(USR2); 2044 #undef SSH_SIG 2045 return "SIG@openssh.com"; 2046 } 2047 2048 static void 2049 session_exit_message(Session *s, int status) 2050 { 2051 Channel *c; 2052 2053 if ((c = channel_lookup(s->chanid)) == NULL) 2054 fatal("session_exit_message: session %d: no channel %d", 2055 s->self, s->chanid); 2056 debug("session_exit_message: session %d channel %d pid %ld", 2057 s->self, s->chanid, (long)s->pid); 2058 2059 if (WIFEXITED(status)) { 2060 channel_request_start(s->chanid, "exit-status", 0); 2061 packet_put_int(WEXITSTATUS(status)); 2062 packet_send(); 2063 } else if (WIFSIGNALED(status)) { 2064 channel_request_start(s->chanid, "exit-signal", 0); 2065 packet_put_cstring(sig2name(WTERMSIG(status))); 2066 #ifdef WCOREDUMP 2067 packet_put_char(WCOREDUMP(status)); 2068 #else /* WCOREDUMP */ 2069 packet_put_char(0); 2070 #endif /* WCOREDUMP */ 2071 packet_put_cstring(""); 2072 packet_put_cstring(""); 2073 packet_send(); 2074 } else { 2075 /* Some weird exit cause. Just exit. */ 2076 packet_disconnect("wait returned status %04x.", status); 2077 } 2078 2079 /* disconnect channel */ 2080 debug("session_exit_message: release channel %d", s->chanid); 2081 channel_cancel_cleanup(s->chanid); 2082 /* 2083 * emulate a write failure with 'chan_write_failed', nobody will be 2084 * interested in data we write. 2085 * Note that we must not call 'chan_read_failed', since there could 2086 * be some more data waiting in the pipe. 2087 */ 2088 if (c->ostate != CHAN_OUTPUT_CLOSED) 2089 chan_write_failed(c); 2090 s->chanid = -1; 2091 } 2092 2093 void 2094 session_close(Session *s) 2095 { 2096 int i; 2097 2098 debug("session_close: session %d pid %ld", s->self, (long)s->pid); 2099 if (s->ttyfd != -1) 2100 session_pty_cleanup(s); 2101 if (s->term) 2102 xfree(s->term); 2103 if (s->display) 2104 xfree(s->display); 2105 if (s->auth_display) 2106 xfree(s->auth_display); 2107 if (s->auth_data) 2108 xfree(s->auth_data); 2109 if (s->auth_proto) 2110 xfree(s->auth_proto); 2111 s->used = 0; 2112 for (i = 0; i < s->num_env; i++) { 2113 xfree(s->env[i].name); 2114 xfree(s->env[i].val); 2115 } 2116 if (s->env != NULL) 2117 xfree(s->env); 2118 session_proctitle(s); 2119 } 2120 2121 void 2122 session_close_by_pid(pid_t pid, int status) 2123 { 2124 Session *s = session_by_pid(pid); 2125 if (s == NULL) { 2126 debug("session_close_by_pid: no session for pid %ld", 2127 (long)pid); 2128 return; 2129 } 2130 if (s->chanid != -1) 2131 session_exit_message(s, status); 2132 session_close(s); 2133 } 2134 2135 /* 2136 * this is called when a channel dies before 2137 * the session 'child' itself dies 2138 */ 2139 void 2140 session_close_by_channel(int id, void *arg) 2141 { 2142 Session *s = session_by_channel(id); 2143 if (s == NULL) { 2144 debug("session_close_by_channel: no session for id %d", id); 2145 return; 2146 } 2147 debug("session_close_by_channel: channel %d child %ld", 2148 id, (long)s->pid); 2149 if (s->pid != 0) { 2150 debug("session_close_by_channel: channel %d: has child", id); 2151 /* 2152 * delay detach of session, but release pty, since 2153 * the fd's to the child are already closed 2154 */ 2155 if (s->ttyfd != -1) 2156 session_pty_cleanup(s); 2157 return; 2158 } 2159 /* detach by removing callback */ 2160 channel_cancel_cleanup(s->chanid); 2161 s->chanid = -1; 2162 session_close(s); 2163 } 2164 2165 void 2166 session_destroy_all(void (*closefunc)(Session *)) 2167 { 2168 int i; 2169 for (i = 0; i < MAX_SESSIONS; i++) { 2170 Session *s = &sessions[i]; 2171 if (s->used) { 2172 if (closefunc != NULL) 2173 closefunc(s); 2174 else 2175 session_close(s); 2176 } 2177 } 2178 } 2179 2180 static char * 2181 session_tty_list(void) 2182 { 2183 static char buf[1024]; 2184 int i; 2185 char *cp; 2186 2187 buf[0] = '\0'; 2188 for (i = 0; i < MAX_SESSIONS; i++) { 2189 Session *s = &sessions[i]; 2190 if (s->used && s->ttyfd != -1) { 2191 2192 if (strncmp(s->tty, "/dev/", 5) != 0) { 2193 cp = strrchr(s->tty, '/'); 2194 cp = (cp == NULL) ? s->tty : cp + 1; 2195 } else 2196 cp = s->tty + 5; 2197 2198 if (buf[0] != '\0') 2199 strlcat(buf, ",", sizeof buf); 2200 strlcat(buf, cp, sizeof buf); 2201 } 2202 } 2203 if (buf[0] == '\0') 2204 strlcpy(buf, "notty", sizeof buf); 2205 return buf; 2206 } 2207 2208 void 2209 session_proctitle(Session *s) 2210 { 2211 if (s->pw == NULL) 2212 error("no user for session %d", s->self); 2213 else 2214 setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); 2215 } 2216 2217 int 2218 session_setup_x11fwd(Session *s) 2219 { 2220 struct stat st; 2221 char display[512], auth_display[512]; 2222 char hostname[MAXHOSTNAMELEN]; 2223 2224 if (no_x11_forwarding_flag) { 2225 packet_send_debug("X11 forwarding disabled in user configuration file."); 2226 return 0; 2227 } 2228 if (!options.x11_forwarding) { 2229 debug("X11 forwarding disabled in server configuration file."); 2230 return 0; 2231 } 2232 if (!options.xauth_location || 2233 (stat(options.xauth_location, &st) == -1)) { 2234 packet_send_debug("No xauth program; cannot forward with spoofing."); 2235 return 0; 2236 } 2237 if (options.use_login) { 2238 packet_send_debug("X11 forwarding disabled; " 2239 "not compatible with UseLogin=yes."); 2240 return 0; 2241 } 2242 if (s->display != NULL) { 2243 debug("X11 display already set."); 2244 return 0; 2245 } 2246 if (x11_create_display_inet(options.x11_display_offset, 2247 options.x11_use_localhost, s->single_connection, 2248 &s->display_number) == -1) { 2249 debug("x11_create_display_inet failed."); 2250 return 0; 2251 } 2252 2253 /* Set up a suitable value for the DISPLAY variable. */ 2254 if (gethostname(hostname, sizeof(hostname)) < 0) 2255 fatal("gethostname: %.100s", strerror(errno)); 2256 /* 2257 * auth_display must be used as the displayname when the 2258 * authorization entry is added with xauth(1). This will be 2259 * different than the DISPLAY string for localhost displays. 2260 */ 2261 if (options.x11_use_localhost) { 2262 snprintf(display, sizeof display, "localhost:%u.%u", 2263 s->display_number, s->screen); 2264 snprintf(auth_display, sizeof auth_display, "unix:%u.%u", 2265 s->display_number, s->screen); 2266 s->display = xstrdup(display); 2267 s->auth_display = xstrdup(auth_display); 2268 } else { 2269 #ifdef IPADDR_IN_DISPLAY 2270 struct hostent *he; 2271 struct in_addr my_addr; 2272 2273 he = gethostbyname(hostname); 2274 if (he == NULL) { 2275 error("Can't get IP address for X11 DISPLAY."); 2276 packet_send_debug("Can't get IP address for X11 DISPLAY."); 2277 return 0; 2278 } 2279 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); 2280 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr), 2281 s->display_number, s->screen); 2282 #else 2283 snprintf(display, sizeof display, "%.400s:%u.%u", hostname, 2284 s->display_number, s->screen); 2285 #endif 2286 s->display = xstrdup(display); 2287 s->auth_display = xstrdup(display); 2288 } 2289 2290 return 1; 2291 } 2292 2293 static void 2294 do_authenticated2(Authctxt *authctxt) 2295 { 2296 server_loop2(authctxt); 2297 } 2298 2299 void 2300 do_cleanup(Authctxt *authctxt) 2301 { 2302 static int called = 0; 2303 2304 debug("do_cleanup"); 2305 2306 /* no cleanup if we're in the child for login shell */ 2307 if (is_child) 2308 return; 2309 2310 /* avoid double cleanup */ 2311 if (called) 2312 return; 2313 called = 1; 2314 2315 if (authctxt == NULL) 2316 return; 2317 #ifdef KRB5 2318 if (options.kerberos_ticket_cleanup && 2319 authctxt->krb5_ctx) 2320 krb5_cleanup_proc(authctxt); 2321 #endif 2322 2323 #ifdef GSSAPI 2324 if (compat20 && options.gss_cleanup_creds) 2325 ssh_gssapi_cleanup_creds(); 2326 #endif 2327 2328 #ifdef USE_PAM 2329 if (options.use_pam) { 2330 sshpam_cleanup(); 2331 sshpam_thread_cleanup(); 2332 } 2333 #endif 2334 2335 /* remove agent socket */ 2336 auth_sock_cleanup_proc(authctxt->pw); 2337 2338 /* 2339 * Cleanup ptys/utmp only if privsep is disabled, 2340 * or if running in monitor. 2341 */ 2342 if (!use_privsep || mm_is_monitor()) 2343 session_destroy_all(session_pty_cleanup2); 2344 } 2345