session.c revision 147005
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" 36RCSID("$OpenBSD: session.c,v 1.181 2004/12/23 17:35:48 markus Exp $"); 37RCSID("$FreeBSD: head/crypto/openssh/session.c 147005 2005-06-05 15:46:09Z des $"); 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 72Session *session_new(void); 73void session_set_fds(Session *, int, int, int); 74void session_pty_cleanup(Session *); 75void session_proctitle(Session *); 76int session_setup_x11fwd(Session *); 77void do_exec_pty(Session *, const char *); 78void do_exec_no_pty(Session *, const char *); 79void do_exec(Session *, const char *); 80void do_login(Session *, const char *); 81#ifdef LOGIN_NEEDS_UTMPX 82static void do_pre_login(Session *s); 83#endif 84void do_child(Session *, const char *); 85void do_motd(void); 86int check_quietlogin(Session *, const char *); 87 88static void do_authenticated1(Authctxt *); 89static void do_authenticated2(Authctxt *); 90 91static int session_pty_req(Session *); 92 93/* import */ 94extern ServerOptions options; 95extern char *__progname; 96extern int log_stderr; 97extern int debug_flag; 98extern u_int utmp_len; 99extern int startup_pipe; 100extern void destroy_sensitive_data(void); 101extern Buffer loginmsg; 102 103/* original command from peer. */ 104const char *original_command = NULL; 105 106/* data */ 107#define MAX_SESSIONS 10 108Session sessions[MAX_SESSIONS]; 109 110#ifdef HAVE_LOGIN_CAP 111login_cap_t *lc; 112#endif 113 114static int is_child = 0; 115 116/* Name and directory of socket for authentication agent forwarding. */ 117static char *auth_sock_name = NULL; 118static char *auth_sock_dir = NULL; 119 120/* removes the agent forwarding socket */ 121 122static void 123auth_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 134static int 135auth_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 197static void 198display_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 207void 208do_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 */ 239static void 240do_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 if (s == NULL) { 250 error("no more sessions"); 251 return; 252 } 253 s->authctxt = authctxt; 254 s->pw = authctxt->pw; 255 256 /* 257 * We stay in this loop until the client requests to execute a shell 258 * or a command. 259 */ 260 for (;;) { 261 success = 0; 262 263 /* Get a packet from the client. */ 264 type = packet_read(); 265 266 /* Process the packet. */ 267 switch (type) { 268 case SSH_CMSG_REQUEST_COMPRESSION: 269 compression_level = packet_get_int(); 270 packet_check_eom(); 271 if (compression_level < 1 || compression_level > 9) { 272 packet_send_debug("Received invalid compression level %d.", 273 compression_level); 274 break; 275 } 276 if (!options.compression) { 277 debug2("compression disabled"); 278 break; 279 } 280 /* Enable compression after we have responded with SUCCESS. */ 281 enable_compression_after_reply = 1; 282 success = 1; 283 break; 284 285 case SSH_CMSG_REQUEST_PTY: 286 success = session_pty_req(s); 287 break; 288 289 case SSH_CMSG_X11_REQUEST_FORWARDING: 290 s->auth_proto = packet_get_string(&proto_len); 291 s->auth_data = packet_get_string(&data_len); 292 293 screen_flag = packet_get_protocol_flags() & 294 SSH_PROTOFLAG_SCREEN_NUMBER; 295 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag); 296 297 if (packet_remaining() == 4) { 298 if (!screen_flag) 299 debug2("Buggy client: " 300 "X11 screen flag missing"); 301 s->screen = packet_get_int(); 302 } else { 303 s->screen = 0; 304 } 305 packet_check_eom(); 306 success = session_setup_x11fwd(s); 307 if (!success) { 308 xfree(s->auth_proto); 309 xfree(s->auth_data); 310 s->auth_proto = NULL; 311 s->auth_data = NULL; 312 } 313 break; 314 315 case SSH_CMSG_AGENT_REQUEST_FORWARDING: 316 if (no_agent_forwarding_flag || compat13) { 317 debug("Authentication agent forwarding not permitted for this authentication."); 318 break; 319 } 320 debug("Received authentication agent forwarding request."); 321 success = auth_input_request_forwarding(s->pw); 322 break; 323 324 case SSH_CMSG_PORT_FORWARD_REQUEST: 325 if (no_port_forwarding_flag) { 326 debug("Port forwarding not permitted for this authentication."); 327 break; 328 } 329 if (!options.allow_tcp_forwarding) { 330 debug("Port forwarding not permitted."); 331 break; 332 } 333 debug("Received TCP/IP port forwarding request."); 334 channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports); 335 success = 1; 336 break; 337 338 case SSH_CMSG_MAX_PACKET_SIZE: 339 if (packet_set_maxsize(packet_get_int()) > 0) 340 success = 1; 341 break; 342 343 case SSH_CMSG_EXEC_SHELL: 344 case SSH_CMSG_EXEC_CMD: 345 if (type == SSH_CMSG_EXEC_CMD) { 346 command = packet_get_string(&dlen); 347 debug("Exec command '%.500s'", command); 348 do_exec(s, command); 349 xfree(command); 350 } else { 351 do_exec(s, NULL); 352 } 353 packet_check_eom(); 354 session_close(s); 355 return; 356 357 default: 358 /* 359 * Any unknown messages in this phase are ignored, 360 * and a failure message is returned. 361 */ 362 logit("Unknown packet type received after authentication: %d", type); 363 } 364 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); 365 packet_send(); 366 packet_write_wait(); 367 368 /* Enable compression now that we have replied if appropriate. */ 369 if (enable_compression_after_reply) { 370 enable_compression_after_reply = 0; 371 packet_start_compression(compression_level); 372 } 373 } 374} 375 376/* 377 * This is called to fork and execute a command when we have no tty. This 378 * will call do_child from the child, and server_loop from the parent after 379 * setting up file descriptors and such. 380 */ 381void 382do_exec_no_pty(Session *s, const char *command) 383{ 384 pid_t pid; 385 386#ifdef USE_PIPES 387 int pin[2], pout[2], perr[2]; 388 /* Allocate pipes for communicating with the program. */ 389 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) 390 packet_disconnect("Could not create pipes: %.100s", 391 strerror(errno)); 392#else /* USE_PIPES */ 393 int inout[2], err[2]; 394 /* Uses socket pairs to communicate with the program. */ 395 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || 396 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) 397 packet_disconnect("Could not create socket pairs: %.100s", 398 strerror(errno)); 399#endif /* USE_PIPES */ 400 if (s == NULL) 401 fatal("do_exec_no_pty: no session"); 402 403 session_proctitle(s); 404 405#if defined(USE_PAM) 406 if (options.use_pam && !use_privsep) 407 do_pam_setcred(1); 408#endif /* USE_PAM */ 409 410 /* Fork the child. */ 411 if ((pid = fork()) == 0) { 412 is_child = 1; 413 414 /* Child. Reinitialize the log since the pid has changed. */ 415 log_init(__progname, options.log_level, options.log_facility, log_stderr); 416 417 /* 418 * Create a new session and process group since the 4.4BSD 419 * setlogin() affects the entire process group. 420 */ 421 if (setsid() < 0) 422 error("setsid failed: %.100s", strerror(errno)); 423 424#ifdef USE_PIPES 425 /* 426 * Redirect stdin. We close the parent side of the socket 427 * pair, and make the child side the standard input. 428 */ 429 close(pin[1]); 430 if (dup2(pin[0], 0) < 0) 431 perror("dup2 stdin"); 432 close(pin[0]); 433 434 /* Redirect stdout. */ 435 close(pout[0]); 436 if (dup2(pout[1], 1) < 0) 437 perror("dup2 stdout"); 438 close(pout[1]); 439 440 /* Redirect stderr. */ 441 close(perr[0]); 442 if (dup2(perr[1], 2) < 0) 443 perror("dup2 stderr"); 444 close(perr[1]); 445#else /* USE_PIPES */ 446 /* 447 * Redirect stdin, stdout, and stderr. Stdin and stdout will 448 * use the same socket, as some programs (particularly rdist) 449 * seem to depend on it. 450 */ 451 close(inout[1]); 452 close(err[1]); 453 if (dup2(inout[0], 0) < 0) /* stdin */ 454 perror("dup2 stdin"); 455 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ 456 perror("dup2 stdout"); 457 if (dup2(err[0], 2) < 0) /* stderr */ 458 perror("dup2 stderr"); 459#endif /* USE_PIPES */ 460 461#ifdef _UNICOS 462 cray_init_job(s->pw); /* set up cray jid and tmpdir */ 463#endif 464 465 /* Do processing for the child (exec command etc). */ 466 do_child(s, command); 467 /* NOTREACHED */ 468 } 469#ifdef _UNICOS 470 signal(WJSIGNAL, cray_job_termination_handler); 471#endif /* _UNICOS */ 472#ifdef HAVE_CYGWIN 473 if (is_winnt) 474 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); 475#endif 476 if (pid < 0) 477 packet_disconnect("fork failed: %.100s", strerror(errno)); 478 s->pid = pid; 479 /* Set interactive/non-interactive mode. */ 480 packet_set_interactive(s->display != NULL); 481#ifdef USE_PIPES 482 /* We are the parent. Close the child sides of the pipes. */ 483 close(pin[0]); 484 close(pout[1]); 485 close(perr[1]); 486 487 if (compat20) { 488 if (s->is_subsystem) { 489 close(perr[0]); 490 perr[0] = -1; 491 } 492 session_set_fds(s, pin[1], pout[0], perr[0]); 493 } else { 494 /* Enter the interactive session. */ 495 server_loop(pid, pin[1], pout[0], perr[0]); 496 /* server_loop has closed pin[1], pout[0], and perr[0]. */ 497 } 498#else /* USE_PIPES */ 499 /* We are the parent. Close the child sides of the socket pairs. */ 500 close(inout[0]); 501 close(err[0]); 502 503 /* 504 * Clear loginmsg, since it's the child's responsibility to display 505 * it to the user, otherwise multiple sessions may accumulate 506 * multiple copies of the login messages. 507 */ 508 buffer_clear(&loginmsg); 509 510 /* 511 * Enter the interactive session. Note: server_loop must be able to 512 * handle the case that fdin and fdout are the same. 513 */ 514 if (compat20) { 515 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]); 516 } else { 517 server_loop(pid, inout[1], inout[1], err[1]); 518 /* server_loop has closed inout[1] and err[1]. */ 519 } 520#endif /* USE_PIPES */ 521} 522 523/* 524 * This is called to fork and execute a command when we have a tty. This 525 * will call do_child from the child, and server_loop from the parent after 526 * setting up file descriptors, controlling tty, updating wtmp, utmp, 527 * lastlog, and other such operations. 528 */ 529void 530do_exec_pty(Session *s, const char *command) 531{ 532 int fdout, ptyfd, ttyfd, ptymaster; 533 pid_t pid; 534 535 if (s == NULL) 536 fatal("do_exec_pty: no session"); 537 ptyfd = s->ptyfd; 538 ttyfd = s->ttyfd; 539 540#if defined(USE_PAM) 541 if (options.use_pam) { 542 do_pam_set_tty(s->tty); 543 if (!use_privsep) 544 do_pam_setcred(1); 545 } 546#endif 547 548 /* Fork the child. */ 549 if ((pid = fork()) == 0) { 550 is_child = 1; 551 552 /* Child. Reinitialize the log because the pid has changed. */ 553 log_init(__progname, options.log_level, options.log_facility, log_stderr); 554 /* Close the master side of the pseudo tty. */ 555 close(ptyfd); 556 557 /* Make the pseudo tty our controlling tty. */ 558 pty_make_controlling_tty(&ttyfd, s->tty); 559 560 /* Redirect stdin/stdout/stderr from the pseudo tty. */ 561 if (dup2(ttyfd, 0) < 0) 562 error("dup2 stdin: %s", strerror(errno)); 563 if (dup2(ttyfd, 1) < 0) 564 error("dup2 stdout: %s", strerror(errno)); 565 if (dup2(ttyfd, 2) < 0) 566 error("dup2 stderr: %s", strerror(errno)); 567 568 /* Close the extra descriptor for the pseudo tty. */ 569 close(ttyfd); 570 571 /* record login, etc. similar to login(1) */ 572#ifndef HAVE_OSF_SIA 573 if (!(options.use_login && command == NULL)) { 574#ifdef _UNICOS 575 cray_init_job(s->pw); /* set up cray jid and tmpdir */ 576#endif /* _UNICOS */ 577 do_login(s, command); 578 } 579# ifdef LOGIN_NEEDS_UTMPX 580 else 581 do_pre_login(s); 582# endif 583#endif 584 585 /* Do common processing for the child, such as execing the command. */ 586 do_child(s, command); 587 /* NOTREACHED */ 588 } 589#ifdef _UNICOS 590 signal(WJSIGNAL, cray_job_termination_handler); 591#endif /* _UNICOS */ 592#ifdef HAVE_CYGWIN 593 if (is_winnt) 594 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); 595#endif 596 if (pid < 0) 597 packet_disconnect("fork failed: %.100s", strerror(errno)); 598 s->pid = pid; 599 600 /* Parent. Close the slave side of the pseudo tty. */ 601 close(ttyfd); 602 603 /* 604 * Create another descriptor of the pty master side for use as the 605 * standard input. We could use the original descriptor, but this 606 * simplifies code in server_loop. The descriptor is bidirectional. 607 */ 608 fdout = dup(ptyfd); 609 if (fdout < 0) 610 packet_disconnect("dup #1 failed: %.100s", strerror(errno)); 611 612 /* we keep a reference to the pty master */ 613 ptymaster = dup(ptyfd); 614 if (ptymaster < 0) 615 packet_disconnect("dup #2 failed: %.100s", strerror(errno)); 616 s->ptymaster = ptymaster; 617 618 /* Enter interactive session. */ 619 packet_set_interactive(1); 620 if (compat20) { 621 session_set_fds(s, ptyfd, fdout, -1); 622 } else { 623 server_loop(pid, ptyfd, fdout, -1); 624 /* server_loop _has_ closed ptyfd and fdout. */ 625 } 626} 627 628#ifdef LOGIN_NEEDS_UTMPX 629static void 630do_pre_login(Session *s) 631{ 632 socklen_t fromlen; 633 struct sockaddr_storage from; 634 pid_t pid = getpid(); 635 636 /* 637 * Get IP address of client. If the connection is not a socket, let 638 * the address be 0.0.0.0. 639 */ 640 memset(&from, 0, sizeof(from)); 641 fromlen = sizeof(from); 642 if (packet_connection_is_on_socket()) { 643 if (getpeername(packet_get_connection_in(), 644 (struct sockaddr *) & from, &fromlen) < 0) { 645 debug("getpeername: %.100s", strerror(errno)); 646 cleanup_exit(255); 647 } 648 } 649 650 record_utmp_only(pid, s->tty, s->pw->pw_name, 651 get_remote_name_or_ip(utmp_len, options.use_dns), 652 (struct sockaddr *)&from, fromlen); 653} 654#endif 655 656/* 657 * This is called to fork and execute a command. If another command is 658 * to be forced, execute that instead. 659 */ 660void 661do_exec(Session *s, const char *command) 662{ 663 if (forced_command) { 664 original_command = command; 665 command = forced_command; 666 debug("Forced command '%.900s'", command); 667 } 668 669#ifdef SSH_AUDIT_EVENTS 670 if (command != NULL) 671 PRIVSEP(audit_run_command(command)); 672 else if (s->ttyfd == -1) { 673 char *shell = s->pw->pw_shell; 674 675 if (shell[0] == '\0') /* empty shell means /bin/sh */ 676 shell =_PATH_BSHELL; 677 PRIVSEP(audit_run_command(shell)); 678 } 679#endif 680 681 if (s->ttyfd != -1) 682 do_exec_pty(s, command); 683 else 684 do_exec_no_pty(s, command); 685 686 original_command = NULL; 687 688 /* 689 * Clear loginmsg: it's the child's responsibility to display 690 * it to the user, otherwise multiple sessions may accumulate 691 * multiple copies of the login messages. 692 */ 693 buffer_clear(&loginmsg); 694} 695 696/* administrative, login(1)-like work */ 697void 698do_login(Session *s, const char *command) 699{ 700 socklen_t fromlen; 701 struct sockaddr_storage from; 702 struct passwd * pw = s->pw; 703 pid_t pid = getpid(); 704 705 /* 706 * Get IP address of client. If the connection is not a socket, let 707 * the address be 0.0.0.0. 708 */ 709 memset(&from, 0, sizeof(from)); 710 fromlen = sizeof(from); 711 if (packet_connection_is_on_socket()) { 712 if (getpeername(packet_get_connection_in(), 713 (struct sockaddr *) & from, &fromlen) < 0) { 714 debug("getpeername: %.100s", strerror(errno)); 715 cleanup_exit(255); 716 } 717 } 718 719 /* Record that there was a login on that tty from the remote host. */ 720 if (!use_privsep) 721 record_login(pid, s->tty, pw->pw_name, pw->pw_uid, 722 get_remote_name_or_ip(utmp_len, 723 options.use_dns), 724 (struct sockaddr *)&from, fromlen); 725 726#ifdef USE_PAM 727 /* 728 * If password change is needed, do it now. 729 * This needs to occur before the ~/.hushlogin check. 730 */ 731 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) { 732 display_loginmsg(); 733 do_pam_chauthtok(); 734 s->authctxt->force_pwchange = 0; 735 /* XXX - signal [net] parent to enable forwardings */ 736 } 737#endif 738 739 if (check_quietlogin(s, command)) 740 return; 741 742 display_loginmsg(); 743 744 do_motd(); 745} 746 747/* 748 * Display the message of the day. 749 */ 750void 751do_motd(void) 752{ 753 FILE *f; 754 char buf[256]; 755#ifdef HAVE_LOGIN_CAP 756 const char *fname; 757#endif 758 759#ifdef HAVE_LOGIN_CAP 760 fname = login_getcapstr(lc, "copyright", NULL, NULL); 761 if (fname != NULL && (f = fopen(fname, "r")) != NULL) { 762 while (fgets(buf, sizeof(buf), f) != NULL) 763 fputs(buf, stdout); 764 fclose(f); 765 } else 766#endif /* HAVE_LOGIN_CAP */ 767 (void)printf("%s\n\t%s %s\n", 768 "Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994", 769 "The Regents of the University of California. ", 770 "All rights reserved."); 771 772 (void)printf("\n"); 773 774 if (options.print_motd) { 775#ifdef HAVE_LOGIN_CAP 776 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd", 777 "/etc/motd"), "r"); 778#else 779 f = fopen("/etc/motd", "r"); 780#endif 781 if (f) { 782 while (fgets(buf, sizeof(buf), f)) 783 fputs(buf, stdout); 784 fclose(f); 785 } 786 } 787} 788 789 790/* 791 * Check for quiet login, either .hushlogin or command given. 792 */ 793int 794check_quietlogin(Session *s, const char *command) 795{ 796 char buf[256]; 797 struct passwd *pw = s->pw; 798 struct stat st; 799 800 /* Return 1 if .hushlogin exists or a command given. */ 801 if (command != NULL) 802 return 1; 803 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); 804#ifdef HAVE_LOGIN_CAP 805 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) 806 return 1; 807#else 808 if (stat(buf, &st) >= 0) 809 return 1; 810#endif 811 return 0; 812} 813 814/* 815 * Sets the value of the given variable in the environment. If the variable 816 * already exists, its value is overriden. 817 */ 818void 819child_set_env(char ***envp, u_int *envsizep, const char *name, 820 const char *value) 821{ 822 char **env; 823 u_int envsize; 824 u_int i, namelen; 825 826 /* 827 * If we're passed an uninitialized list, allocate a single null 828 * entry before continuing. 829 */ 830 if (*envp == NULL && *envsizep == 0) { 831 *envp = xmalloc(sizeof(char *)); 832 *envp[0] = NULL; 833 *envsizep = 1; 834 } 835 836 /* 837 * Find the slot where the value should be stored. If the variable 838 * already exists, we reuse the slot; otherwise we append a new slot 839 * at the end of the array, expanding if necessary. 840 */ 841 env = *envp; 842 namelen = strlen(name); 843 for (i = 0; env[i]; i++) 844 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 845 break; 846 if (env[i]) { 847 /* Reuse the slot. */ 848 xfree(env[i]); 849 } else { 850 /* New variable. Expand if necessary. */ 851 envsize = *envsizep; 852 if (i >= envsize - 1) { 853 if (envsize >= 1000) 854 fatal("child_set_env: too many env vars"); 855 envsize += 50; 856 env = (*envp) = xrealloc(env, envsize * sizeof(char *)); 857 *envsizep = envsize; 858 } 859 /* Need to set the NULL pointer at end of array beyond the new slot. */ 860 env[i + 1] = NULL; 861 } 862 863 /* Allocate space and format the variable in the appropriate slot. */ 864 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 865 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 866} 867 868/* 869 * Reads environment variables from the given file and adds/overrides them 870 * into the environment. If the file does not exist, this does nothing. 871 * Otherwise, it must consist of empty lines, comments (line starts with '#') 872 * and assignments of the form name=value. No other forms are allowed. 873 */ 874static void 875read_environment_file(char ***env, u_int *envsize, 876 const char *filename) 877{ 878 FILE *f; 879 char buf[4096]; 880 char *cp, *value; 881 u_int lineno = 0; 882 883 f = fopen(filename, "r"); 884 if (!f) 885 return; 886 887 while (fgets(buf, sizeof(buf), f)) { 888 if (++lineno > 1000) 889 fatal("Too many lines in environment file %s", filename); 890 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) 891 ; 892 if (!*cp || *cp == '#' || *cp == '\n') 893 continue; 894 if (strchr(cp, '\n')) 895 *strchr(cp, '\n') = '\0'; 896 value = strchr(cp, '='); 897 if (value == NULL) { 898 fprintf(stderr, "Bad line %u in %.100s\n", lineno, 899 filename); 900 continue; 901 } 902 /* 903 * Replace the equals sign by nul, and advance value to 904 * the value string. 905 */ 906 *value = '\0'; 907 value++; 908 child_set_env(env, envsize, cp, value); 909 } 910 fclose(f); 911} 912 913#ifdef HAVE_ETC_DEFAULT_LOGIN 914/* 915 * Return named variable from specified environment, or NULL if not present. 916 */ 917static char * 918child_get_env(char **env, const char *name) 919{ 920 int i; 921 size_t len; 922 923 len = strlen(name); 924 for (i=0; env[i] != NULL; i++) 925 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=') 926 return(env[i] + len + 1); 927 return NULL; 928} 929 930/* 931 * Read /etc/default/login. 932 * We pick up the PATH (or SUPATH for root) and UMASK. 933 */ 934static void 935read_etc_default_login(char ***env, u_int *envsize, uid_t uid) 936{ 937 char **tmpenv = NULL, *var; 938 u_int i, tmpenvsize = 0; 939 u_long mask; 940 941 /* 942 * We don't want to copy the whole file to the child's environment, 943 * so we use a temporary environment and copy the variables we're 944 * interested in. 945 */ 946 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login"); 947 948 if (tmpenv == NULL) 949 return; 950 951 if (uid == 0) 952 var = child_get_env(tmpenv, "SUPATH"); 953 else 954 var = child_get_env(tmpenv, "PATH"); 955 if (var != NULL) 956 child_set_env(env, envsize, "PATH", var); 957 958 if ((var = child_get_env(tmpenv, "UMASK")) != NULL) 959 if (sscanf(var, "%5lo", &mask) == 1) 960 umask((mode_t)mask); 961 962 for (i = 0; tmpenv[i] != NULL; i++) 963 xfree(tmpenv[i]); 964 xfree(tmpenv); 965} 966#endif /* HAVE_ETC_DEFAULT_LOGIN */ 967 968void copy_environment(char **source, char ***env, u_int *envsize) 969{ 970 char *var_name, *var_val; 971 int i; 972 973 if (source == NULL) 974 return; 975 976 for(i = 0; source[i] != NULL; i++) { 977 var_name = xstrdup(source[i]); 978 if ((var_val = strstr(var_name, "=")) == NULL) { 979 xfree(var_name); 980 continue; 981 } 982 *var_val++ = '\0'; 983 984 debug3("Copy environment: %s=%s", var_name, var_val); 985 child_set_env(env, envsize, var_name, var_val); 986 987 xfree(var_name); 988 } 989} 990 991static char ** 992do_setup_env(Session *s, const char *shell) 993{ 994 char buf[256]; 995 u_int i, envsize; 996 char **env, *laddr, *path = NULL; 997#ifdef HAVE_LOGIN_CAP 998 extern char **environ; 999 char **senv, **var; 1000#endif 1001 struct passwd *pw = s->pw; 1002 1003 /* Initialize the environment. */ 1004 envsize = 100; 1005 env = xmalloc(envsize * sizeof(char *)); 1006 env[0] = NULL; 1007 1008#ifdef HAVE_CYGWIN 1009 /* 1010 * The Windows environment contains some setting which are 1011 * important for a running system. They must not be dropped. 1012 */ 1013 { 1014 char **p; 1015 1016 p = fetch_windows_environment(); 1017 copy_environment(p, &env, &envsize); 1018 free_windows_environment(p); 1019 } 1020#endif 1021 1022 if (getenv("TZ")) 1023 child_set_env(&env, &envsize, "TZ", getenv("TZ")); 1024 1025#ifdef GSSAPI 1026 /* Allow any GSSAPI methods that we've used to alter 1027 * the childs environment as they see fit 1028 */ 1029 ssh_gssapi_do_child(&env, &envsize); 1030#endif 1031 1032 if (!options.use_login) { 1033 /* Set basic environment. */ 1034 for (i = 0; i < s->num_env; i++) 1035 child_set_env(&env, &envsize, s->env[i].name, 1036 s->env[i].val); 1037 1038 child_set_env(&env, &envsize, "USER", pw->pw_name); 1039 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); 1040#ifdef _AIX 1041 child_set_env(&env, &envsize, "LOGIN", pw->pw_name); 1042#endif 1043 child_set_env(&env, &envsize, "HOME", pw->pw_dir); 1044 snprintf(buf, sizeof buf, "%.200s/%.50s", 1045 _PATH_MAILDIR, pw->pw_name); 1046 child_set_env(&env, &envsize, "MAIL", buf); 1047#ifdef HAVE_LOGIN_CAP 1048 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); 1049 child_set_env(&env, &envsize, "TERM", "su"); 1050 senv = environ; 1051 environ = xmalloc(sizeof(char *)); 1052 *environ = NULL; 1053 (void) setusercontext(lc, pw, pw->pw_uid, 1054 LOGIN_SETENV|LOGIN_SETPATH); 1055 copy_environment(environ, &env, &envsize); 1056 for (var = environ; *var != NULL; ++var) 1057 xfree(*var); 1058 xfree(environ); 1059 environ = senv; 1060#else /* HAVE_LOGIN_CAP */ 1061# ifndef HAVE_CYGWIN 1062 /* 1063 * There's no standard path on Windows. The path contains 1064 * important components pointing to the system directories, 1065 * needed for loading shared libraries. So the path better 1066 * remains intact here. 1067 */ 1068# ifdef HAVE_ETC_DEFAULT_LOGIN 1069 read_etc_default_login(&env, &envsize, pw->pw_uid); 1070 path = child_get_env(env, "PATH"); 1071# endif /* HAVE_ETC_DEFAULT_LOGIN */ 1072 if (path == NULL || *path == '\0') { 1073 child_set_env(&env, &envsize, "PATH", 1074 s->pw->pw_uid == 0 ? 1075 SUPERUSER_PATH : _PATH_STDPATH); 1076 } 1077# endif /* HAVE_CYGWIN */ 1078#endif /* HAVE_LOGIN_CAP */ 1079 1080 /* Normal systems set SHELL by default. */ 1081 child_set_env(&env, &envsize, "SHELL", shell); 1082 } 1083 1084 /* Set custom environment options from RSA authentication. */ 1085 if (!options.use_login) { 1086 while (custom_environment) { 1087 struct envstring *ce = custom_environment; 1088 char *str = ce->s; 1089 1090 for (i = 0; str[i] != '=' && str[i]; i++) 1091 ; 1092 if (str[i] == '=') { 1093 str[i] = 0; 1094 child_set_env(&env, &envsize, str, str + i + 1); 1095 } 1096 custom_environment = ce->next; 1097 xfree(ce->s); 1098 xfree(ce); 1099 } 1100 } 1101 1102 /* SSH_CLIENT deprecated */ 1103 snprintf(buf, sizeof buf, "%.50s %d %d", 1104 get_remote_ipaddr(), get_remote_port(), get_local_port()); 1105 child_set_env(&env, &envsize, "SSH_CLIENT", buf); 1106 1107 laddr = get_local_ipaddr(packet_get_connection_in()); 1108 snprintf(buf, sizeof buf, "%.50s %d %.50s %d", 1109 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port()); 1110 xfree(laddr); 1111 child_set_env(&env, &envsize, "SSH_CONNECTION", buf); 1112 1113 if (s->ttyfd != -1) 1114 child_set_env(&env, &envsize, "SSH_TTY", s->tty); 1115 if (s->term) 1116 child_set_env(&env, &envsize, "TERM", s->term); 1117 if (s->display) 1118 child_set_env(&env, &envsize, "DISPLAY", s->display); 1119 if (original_command) 1120 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", 1121 original_command); 1122 1123#ifdef _UNICOS 1124 if (cray_tmpdir[0] != '\0') 1125 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir); 1126#endif /* _UNICOS */ 1127 1128 /* 1129 * Since we clear KRB5CCNAME at startup, if it's set now then it 1130 * must have been set by a native authentication method (eg AIX or 1131 * SIA), so copy it to the child. 1132 */ 1133 { 1134 char *cp; 1135 1136 if ((cp = getenv("KRB5CCNAME")) != NULL) 1137 child_set_env(&env, &envsize, "KRB5CCNAME", cp); 1138 } 1139 1140#ifdef _AIX 1141 { 1142 char *cp; 1143 1144 if ((cp = getenv("AUTHSTATE")) != NULL) 1145 child_set_env(&env, &envsize, "AUTHSTATE", cp); 1146 read_environment_file(&env, &envsize, "/etc/environment"); 1147 } 1148#endif 1149#ifdef KRB5 1150 if (s->authctxt->krb5_ccname) 1151 child_set_env(&env, &envsize, "KRB5CCNAME", 1152 s->authctxt->krb5_ccname); 1153#endif 1154#ifdef USE_PAM 1155 /* 1156 * Pull in any environment variables that may have 1157 * been set by PAM. 1158 */ 1159 if (options.use_pam) { 1160 char **p; 1161 1162 p = fetch_pam_child_environment(); 1163 copy_environment(p, &env, &envsize); 1164 free_pam_environment(p); 1165 1166 p = fetch_pam_environment(); 1167 copy_environment(p, &env, &envsize); 1168 free_pam_environment(p); 1169 } 1170#endif /* USE_PAM */ 1171 1172 if (auth_sock_name != NULL) 1173 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, 1174 auth_sock_name); 1175 1176 /* read $HOME/.ssh/environment. */ 1177 if (options.permit_user_env && !options.use_login) { 1178 snprintf(buf, sizeof buf, "%.200s/.ssh/environment", 1179 strcmp(pw->pw_dir, "/") ? pw->pw_dir : ""); 1180 read_environment_file(&env, &envsize, buf); 1181 } 1182 if (debug_flag) { 1183 /* dump the environment */ 1184 fprintf(stderr, "Environment:\n"); 1185 for (i = 0; env[i]; i++) 1186 fprintf(stderr, " %.200s\n", env[i]); 1187 } 1188 return env; 1189} 1190 1191/* 1192 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found 1193 * first in this order). 1194 */ 1195static void 1196do_rc_files(Session *s, const char *shell) 1197{ 1198 FILE *f = NULL; 1199 char cmd[1024]; 1200 int do_xauth; 1201 struct stat st; 1202 1203 do_xauth = 1204 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; 1205 1206 /* ignore _PATH_SSH_USER_RC for subsystems */ 1207 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) { 1208 snprintf(cmd, sizeof cmd, "%s -c '%s %s'", 1209 shell, _PATH_BSHELL, _PATH_SSH_USER_RC); 1210 if (debug_flag) 1211 fprintf(stderr, "Running %s\n", cmd); 1212 f = popen(cmd, "w"); 1213 if (f) { 1214 if (do_xauth) 1215 fprintf(f, "%s %s\n", s->auth_proto, 1216 s->auth_data); 1217 pclose(f); 1218 } else 1219 fprintf(stderr, "Could not run %s\n", 1220 _PATH_SSH_USER_RC); 1221 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { 1222 if (debug_flag) 1223 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, 1224 _PATH_SSH_SYSTEM_RC); 1225 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); 1226 if (f) { 1227 if (do_xauth) 1228 fprintf(f, "%s %s\n", s->auth_proto, 1229 s->auth_data); 1230 pclose(f); 1231 } else 1232 fprintf(stderr, "Could not run %s\n", 1233 _PATH_SSH_SYSTEM_RC); 1234 } else if (do_xauth && options.xauth_location != NULL) { 1235 /* Add authority data to .Xauthority if appropriate. */ 1236 if (debug_flag) { 1237 fprintf(stderr, 1238 "Running %.500s remove %.100s\n", 1239 options.xauth_location, s->auth_display); 1240 fprintf(stderr, 1241 "%.500s add %.100s %.100s %.100s\n", 1242 options.xauth_location, s->auth_display, 1243 s->auth_proto, s->auth_data); 1244 } 1245 snprintf(cmd, sizeof cmd, "%s -q -", 1246 options.xauth_location); 1247 f = popen(cmd, "w"); 1248 if (f) { 1249 fprintf(f, "remove %s\n", 1250 s->auth_display); 1251 fprintf(f, "add %s %s %s\n", 1252 s->auth_display, s->auth_proto, 1253 s->auth_data); 1254 pclose(f); 1255 } else { 1256 fprintf(stderr, "Could not run %s\n", 1257 cmd); 1258 } 1259 } 1260} 1261 1262static void 1263do_nologin(struct passwd *pw) 1264{ 1265 FILE *f = NULL; 1266 char buf[1024]; 1267 1268#ifdef HAVE_LOGIN_CAP 1269 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) 1270 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, 1271 _PATH_NOLOGIN), "r"); 1272#else 1273 if (pw->pw_uid) 1274 f = fopen(_PATH_NOLOGIN, "r"); 1275#endif 1276 if (f) { 1277 /* /etc/nologin exists. Print its contents and exit. */ 1278 logit("User %.100s not allowed because %s exists", 1279 pw->pw_name, _PATH_NOLOGIN); 1280 while (fgets(buf, sizeof(buf), f)) 1281 fputs(buf, stderr); 1282 fclose(f); 1283 fflush(NULL); 1284 exit(254); 1285 } 1286} 1287 1288/* Set login name, uid, gid, and groups. */ 1289void 1290do_setusercontext(struct passwd *pw) 1291{ 1292#ifndef HAVE_CYGWIN 1293 if (getuid() == 0 || geteuid() == 0) 1294#endif /* HAVE_CYGWIN */ 1295 { 1296 1297#ifdef HAVE_SETPCRED 1298 if (setpcred(pw->pw_name, (char **)NULL) == -1) 1299 fatal("Failed to set process credentials"); 1300#endif /* HAVE_SETPCRED */ 1301#ifdef HAVE_LOGIN_CAP 1302# ifdef __bsdi__ 1303 setpgid(0, 0); 1304# endif 1305#ifdef GSSAPI 1306 if (options.gss_authentication) { 1307 temporarily_use_uid(pw); 1308 ssh_gssapi_storecreds(); 1309 restore_uid(); 1310 } 1311#endif 1312# ifdef USE_PAM 1313 if (options.use_pam) { 1314 do_pam_session(); 1315 do_pam_setcred(0); 1316 } 1317# endif /* USE_PAM */ 1318 if (setusercontext(lc, pw, pw->pw_uid, 1319 (LOGIN_SETALL & ~(LOGIN_SETENV|LOGIN_SETPATH))) < 0) { 1320 perror("unable to set user context"); 1321 exit(1); 1322 } 1323#else 1324# if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) 1325 /* Sets login uid for accounting */ 1326 if (getluid() == -1 && setluid(pw->pw_uid) == -1) 1327 error("setluid: %s", strerror(errno)); 1328# endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */ 1329 1330 if (setlogin(pw->pw_name) < 0) 1331 error("setlogin failed: %s", strerror(errno)); 1332 if (setgid(pw->pw_gid) < 0) { 1333 perror("setgid"); 1334 exit(1); 1335 } 1336 /* Initialize the group list. */ 1337 if (initgroups(pw->pw_name, pw->pw_gid) < 0) { 1338 perror("initgroups"); 1339 exit(1); 1340 } 1341 endgrent(); 1342#ifdef GSSAPI 1343 if (options.gss_authentication) { 1344 temporarily_use_uid(pw); 1345 ssh_gssapi_storecreds(); 1346 restore_uid(); 1347 } 1348#endif 1349# ifdef USE_PAM 1350 /* 1351 * PAM credentials may take the form of supplementary groups. 1352 * These will have been wiped by the above initgroups() call. 1353 * Reestablish them here. 1354 */ 1355 if (options.use_pam) { 1356 do_pam_session(); 1357 do_pam_setcred(0); 1358 } 1359# endif /* USE_PAM */ 1360# if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) 1361 irix_setusercontext(pw); 1362# endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */ 1363# ifdef _AIX 1364 aix_usrinfo(pw); 1365# endif /* _AIX */ 1366 /* Permanently switch to the desired uid. */ 1367 permanently_set_uid(pw); 1368#endif 1369 } 1370 1371#ifdef HAVE_CYGWIN 1372 if (is_winnt) 1373#endif 1374 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) 1375 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); 1376} 1377 1378static void 1379do_pwchange(Session *s) 1380{ 1381 fflush(NULL); 1382 fprintf(stderr, "WARNING: Your password has expired.\n"); 1383 if (s->ttyfd != -1) { 1384 fprintf(stderr, 1385 "You must change your password now and login again!\n"); 1386#ifdef PASSWD_NEEDS_USERNAME 1387 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name, 1388 (char *)NULL); 1389#else 1390 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL); 1391#endif 1392 perror("passwd"); 1393 } else { 1394 fprintf(stderr, 1395 "Password change required but no TTY available.\n"); 1396 } 1397 exit(1); 1398} 1399 1400static void 1401launch_login(struct passwd *pw, const char *hostname) 1402{ 1403 /* Launch login(1). */ 1404 1405 execl(LOGIN_PROGRAM, "login", "-h", hostname, 1406#ifdef xxxLOGIN_NEEDS_TERM 1407 (s->term ? s->term : "unknown"), 1408#endif /* LOGIN_NEEDS_TERM */ 1409#ifdef LOGIN_NO_ENDOPT 1410 "-p", "-f", pw->pw_name, (char *)NULL); 1411#else 1412 "-p", "-f", "--", pw->pw_name, (char *)NULL); 1413#endif 1414 1415 /* Login couldn't be executed, die. */ 1416 1417 perror("login"); 1418 exit(1); 1419} 1420 1421static void 1422child_close_fds(void) 1423{ 1424 int i; 1425 1426 if (packet_get_connection_in() == packet_get_connection_out()) 1427 close(packet_get_connection_in()); 1428 else { 1429 close(packet_get_connection_in()); 1430 close(packet_get_connection_out()); 1431 } 1432 /* 1433 * Close all descriptors related to channels. They will still remain 1434 * open in the parent. 1435 */ 1436 /* XXX better use close-on-exec? -markus */ 1437 channel_close_all(); 1438 1439 /* 1440 * Close any extra file descriptors. Note that there may still be 1441 * descriptors left by system functions. They will be closed later. 1442 */ 1443 endpwent(); 1444 1445 /* 1446 * Close any extra open file descriptors so that we don\'t have them 1447 * hanging around in clients. Note that we want to do this after 1448 * initgroups, because at least on Solaris 2.3 it leaves file 1449 * descriptors open. 1450 */ 1451 for (i = 3; i < 64; i++) 1452 close(i); 1453} 1454 1455/* 1456 * Performs common processing for the child, such as setting up the 1457 * environment, closing extra file descriptors, setting the user and group 1458 * ids, and executing the command or shell. 1459 */ 1460void 1461do_child(Session *s, const char *command) 1462{ 1463 extern char **environ; 1464 char **env; 1465 char *argv[10]; 1466 const char *shell, *shell0, *hostname = NULL; 1467 struct passwd *pw = s->pw; 1468#ifdef HAVE_LOGIN_CAP 1469 int lc_requirehome; 1470#endif 1471 1472 /* remove hostkey from the child's memory */ 1473 destroy_sensitive_data(); 1474 1475 /* Force a password change */ 1476 if (s->authctxt->force_pwchange) { 1477 do_setusercontext(pw); 1478 child_close_fds(); 1479 do_pwchange(s); 1480 exit(1); 1481 } 1482 1483 /* login(1) is only called if we execute the login shell */ 1484 if (options.use_login && command != NULL) 1485 options.use_login = 0; 1486 1487#ifdef _UNICOS 1488 cray_setup(pw->pw_uid, pw->pw_name, command); 1489#endif /* _UNICOS */ 1490 1491 /* 1492 * Login(1) does this as well, and it needs uid 0 for the "-h" 1493 * switch, so we let login(1) to this for us. 1494 */ 1495 if (!options.use_login) { 1496#ifdef HAVE_OSF_SIA 1497 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty); 1498 if (!check_quietlogin(s, command)) 1499 do_motd(); 1500#else /* HAVE_OSF_SIA */ 1501 do_nologin(pw); 1502 do_setusercontext(pw); 1503 /* 1504 * PAM session modules in do_setusercontext may have 1505 * generated messages, so if this in an interactive 1506 * login then display them too. 1507 */ 1508 if (!check_quietlogin(s, command)) 1509 display_loginmsg(); 1510#endif /* HAVE_OSF_SIA */ 1511 } 1512 1513#ifdef USE_PAM 1514 if (options.use_pam && !options.use_login && !is_pam_session_open()) { 1515 debug3("PAM session not opened, exiting"); 1516 display_loginmsg(); 1517 exit(254); 1518 } 1519#endif 1520 1521 /* 1522 * Get the shell from the password data. An empty shell field is 1523 * legal, and means /bin/sh. 1524 */ 1525 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; 1526 1527 /* 1528 * Make sure $SHELL points to the shell from the password file, 1529 * even if shell is overridden from login.conf 1530 */ 1531 env = do_setup_env(s, shell); 1532 1533#ifdef HAVE_LOGIN_CAP 1534 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); 1535#endif 1536 1537 /* we have to stash the hostname before we close our socket. */ 1538 if (options.use_login) 1539 hostname = get_remote_name_or_ip(utmp_len, 1540 options.use_dns); 1541 /* 1542 * Close the connection descriptors; note that this is the child, and 1543 * the server will still have the socket open, and it is important 1544 * that we do not shutdown it. Note that the descriptors cannot be 1545 * closed before building the environment, as we call 1546 * get_remote_ipaddr there. 1547 */ 1548 child_close_fds(); 1549 1550 /* 1551 * Must take new environment into use so that .ssh/rc, 1552 * /etc/ssh/sshrc and xauth are run in the proper environment. 1553 */ 1554 environ = env; 1555 1556#ifdef HAVE_LOGIN_CAP 1557 lc_requirehome = login_getcapbool(lc, "requirehome", 0); 1558 login_close(lc); 1559#endif 1560#if defined(KRB5) && defined(USE_AFS) 1561 /* 1562 * At this point, we check to see if AFS is active and if we have 1563 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see 1564 * if we can (and need to) extend the ticket into an AFS token. If 1565 * we don't do this, we run into potential problems if the user's 1566 * home directory is in AFS and it's not world-readable. 1567 */ 1568 1569 if (options.kerberos_get_afs_token && k_hasafs() && 1570 (s->authctxt->krb5_ctx != NULL)) { 1571 char cell[64]; 1572 1573 debug("Getting AFS token"); 1574 1575 k_setpag(); 1576 1577 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) 1578 krb5_afslog(s->authctxt->krb5_ctx, 1579 s->authctxt->krb5_fwd_ccache, cell, NULL); 1580 1581 krb5_afslog_home(s->authctxt->krb5_ctx, 1582 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir); 1583 } 1584#endif 1585 1586 /* Change current directory to the user\'s home directory. */ 1587 if (chdir(pw->pw_dir) < 0) { 1588 fprintf(stderr, "Could not chdir to home directory %s: %s\n", 1589 pw->pw_dir, strerror(errno)); 1590#ifdef HAVE_LOGIN_CAP 1591 if (lc_requirehome) 1592 exit(1); 1593#endif 1594 } 1595 1596 if (!options.use_login) 1597 do_rc_files(s, shell); 1598 1599 /* restore SIGPIPE for child */ 1600 signal(SIGPIPE, SIG_DFL); 1601 1602 if (options.use_login) { 1603 launch_login(pw, hostname); 1604 /* NEVERREACHED */ 1605 } 1606 1607 /* Get the last component of the shell name. */ 1608 if ((shell0 = strrchr(shell, '/')) != NULL) 1609 shell0++; 1610 else 1611 shell0 = shell; 1612 1613 /* 1614 * If we have no command, execute the shell. In this case, the shell 1615 * name to be passed in argv[0] is preceded by '-' to indicate that 1616 * this is a login shell. 1617 */ 1618 if (!command) { 1619 char argv0[256]; 1620 1621 /* Start the shell. Set initial character to '-'. */ 1622 argv0[0] = '-'; 1623 1624 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1) 1625 >= sizeof(argv0) - 1) { 1626 errno = EINVAL; 1627 perror(shell); 1628 exit(1); 1629 } 1630 1631 /* Execute the shell. */ 1632 argv[0] = argv0; 1633 argv[1] = NULL; 1634 execve(shell, argv, env); 1635 1636 /* Executing the shell failed. */ 1637 perror(shell); 1638 exit(1); 1639 } 1640 /* 1641 * Execute the command using the user's shell. This uses the -c 1642 * option to execute the command. 1643 */ 1644 argv[0] = (char *) shell0; 1645 argv[1] = "-c"; 1646 argv[2] = (char *) command; 1647 argv[3] = NULL; 1648 execve(shell, argv, env); 1649 perror(shell); 1650 exit(1); 1651} 1652 1653Session * 1654session_new(void) 1655{ 1656 int i; 1657 static int did_init = 0; 1658 if (!did_init) { 1659 debug("session_new: init"); 1660 for (i = 0; i < MAX_SESSIONS; i++) { 1661 sessions[i].used = 0; 1662 } 1663 did_init = 1; 1664 } 1665 for (i = 0; i < MAX_SESSIONS; i++) { 1666 Session *s = &sessions[i]; 1667 if (! s->used) { 1668 memset(s, 0, sizeof(*s)); 1669 s->chanid = -1; 1670 s->ptyfd = -1; 1671 s->ttyfd = -1; 1672 s->used = 1; 1673 s->self = i; 1674 debug("session_new: session %d", i); 1675 return s; 1676 } 1677 } 1678 return NULL; 1679} 1680 1681static void 1682session_dump(void) 1683{ 1684 int i; 1685 for (i = 0; i < MAX_SESSIONS; i++) { 1686 Session *s = &sessions[i]; 1687 debug("dump: used %d session %d %p channel %d pid %ld", 1688 s->used, 1689 s->self, 1690 s, 1691 s->chanid, 1692 (long)s->pid); 1693 } 1694} 1695 1696int 1697session_open(Authctxt *authctxt, int chanid) 1698{ 1699 Session *s = session_new(); 1700 debug("session_open: channel %d", chanid); 1701 if (s == NULL) { 1702 error("no more sessions"); 1703 return 0; 1704 } 1705 s->authctxt = authctxt; 1706 s->pw = authctxt->pw; 1707 if (s->pw == NULL || !authctxt->valid) 1708 fatal("no user for session %d", s->self); 1709 debug("session_open: session %d: link with channel %d", s->self, chanid); 1710 s->chanid = chanid; 1711 return 1; 1712} 1713 1714Session * 1715session_by_tty(char *tty) 1716{ 1717 int i; 1718 for (i = 0; i < MAX_SESSIONS; i++) { 1719 Session *s = &sessions[i]; 1720 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) { 1721 debug("session_by_tty: session %d tty %s", i, tty); 1722 return s; 1723 } 1724 } 1725 debug("session_by_tty: unknown tty %.100s", tty); 1726 session_dump(); 1727 return NULL; 1728} 1729 1730static Session * 1731session_by_channel(int id) 1732{ 1733 int i; 1734 for (i = 0; i < MAX_SESSIONS; i++) { 1735 Session *s = &sessions[i]; 1736 if (s->used && s->chanid == id) { 1737 debug("session_by_channel: session %d channel %d", i, id); 1738 return s; 1739 } 1740 } 1741 debug("session_by_channel: unknown channel %d", id); 1742 session_dump(); 1743 return NULL; 1744} 1745 1746static Session * 1747session_by_pid(pid_t pid) 1748{ 1749 int i; 1750 debug("session_by_pid: pid %ld", (long)pid); 1751 for (i = 0; i < MAX_SESSIONS; i++) { 1752 Session *s = &sessions[i]; 1753 if (s->used && s->pid == pid) 1754 return s; 1755 } 1756 error("session_by_pid: unknown pid %ld", (long)pid); 1757 session_dump(); 1758 return NULL; 1759} 1760 1761static int 1762session_window_change_req(Session *s) 1763{ 1764 s->col = packet_get_int(); 1765 s->row = packet_get_int(); 1766 s->xpixel = packet_get_int(); 1767 s->ypixel = packet_get_int(); 1768 packet_check_eom(); 1769 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); 1770 return 1; 1771} 1772 1773static int 1774session_pty_req(Session *s) 1775{ 1776 u_int len; 1777 int n_bytes; 1778 1779 if (no_pty_flag) { 1780 debug("Allocating a pty not permitted for this authentication."); 1781 return 0; 1782 } 1783 if (s->ttyfd != -1) { 1784 packet_disconnect("Protocol error: you already have a pty."); 1785 return 0; 1786 } 1787 1788 s->term = packet_get_string(&len); 1789 1790 if (compat20) { 1791 s->col = packet_get_int(); 1792 s->row = packet_get_int(); 1793 } else { 1794 s->row = packet_get_int(); 1795 s->col = packet_get_int(); 1796 } 1797 s->xpixel = packet_get_int(); 1798 s->ypixel = packet_get_int(); 1799 1800 if (strcmp(s->term, "") == 0) { 1801 xfree(s->term); 1802 s->term = NULL; 1803 } 1804 1805 /* Allocate a pty and open it. */ 1806 debug("Allocating pty."); 1807 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) { 1808 if (s->term) 1809 xfree(s->term); 1810 s->term = NULL; 1811 s->ptyfd = -1; 1812 s->ttyfd = -1; 1813 error("session_pty_req: session %d alloc failed", s->self); 1814 return 0; 1815 } 1816 debug("session_pty_req: session %d alloc %s", s->self, s->tty); 1817 1818 /* for SSH1 the tty modes length is not given */ 1819 if (!compat20) 1820 n_bytes = packet_remaining(); 1821 tty_parse_modes(s->ttyfd, &n_bytes); 1822 1823 if (!use_privsep) 1824 pty_setowner(s->pw, s->tty); 1825 1826 /* Set window size from the packet. */ 1827 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); 1828 1829 packet_check_eom(); 1830 session_proctitle(s); 1831 return 1; 1832} 1833 1834static int 1835session_subsystem_req(Session *s) 1836{ 1837 struct stat st; 1838 u_int len; 1839 int success = 0; 1840 char *cmd, *subsys = packet_get_string(&len); 1841 int i; 1842 1843 packet_check_eom(); 1844 logit("subsystem request for %.100s", subsys); 1845 1846 for (i = 0; i < options.num_subsystems; i++) { 1847 if (strcmp(subsys, options.subsystem_name[i]) == 0) { 1848 cmd = options.subsystem_command[i]; 1849 if (stat(cmd, &st) < 0) { 1850 error("subsystem: cannot stat %s: %s", cmd, 1851 strerror(errno)); 1852 break; 1853 } 1854 debug("subsystem: exec() %s", cmd); 1855 s->is_subsystem = 1; 1856 do_exec(s, cmd); 1857 success = 1; 1858 break; 1859 } 1860 } 1861 1862 if (!success) 1863 logit("subsystem request for %.100s failed, subsystem not found", 1864 subsys); 1865 1866 xfree(subsys); 1867 return success; 1868} 1869 1870static int 1871session_x11_req(Session *s) 1872{ 1873 int success; 1874 1875 s->single_connection = packet_get_char(); 1876 s->auth_proto = packet_get_string(NULL); 1877 s->auth_data = packet_get_string(NULL); 1878 s->screen = packet_get_int(); 1879 packet_check_eom(); 1880 1881 success = session_setup_x11fwd(s); 1882 if (!success) { 1883 xfree(s->auth_proto); 1884 xfree(s->auth_data); 1885 s->auth_proto = NULL; 1886 s->auth_data = NULL; 1887 } 1888 return success; 1889} 1890 1891static int 1892session_shell_req(Session *s) 1893{ 1894 packet_check_eom(); 1895 do_exec(s, NULL); 1896 return 1; 1897} 1898 1899static int 1900session_exec_req(Session *s) 1901{ 1902 u_int len; 1903 char *command = packet_get_string(&len); 1904 packet_check_eom(); 1905 do_exec(s, command); 1906 xfree(command); 1907 return 1; 1908} 1909 1910static int 1911session_break_req(Session *s) 1912{ 1913 1914 packet_get_int(); /* ignored */ 1915 packet_check_eom(); 1916 1917 if (s->ttyfd == -1 || 1918 tcsendbreak(s->ttyfd, 0) < 0) 1919 return 0; 1920 return 1; 1921} 1922 1923static int 1924session_env_req(Session *s) 1925{ 1926 char *name, *val; 1927 u_int name_len, val_len, i; 1928 1929 name = packet_get_string(&name_len); 1930 val = packet_get_string(&val_len); 1931 packet_check_eom(); 1932 1933 /* Don't set too many environment variables */ 1934 if (s->num_env > 128) { 1935 debug2("Ignoring env request %s: too many env vars", name); 1936 goto fail; 1937 } 1938 1939 for (i = 0; i < options.num_accept_env; i++) { 1940 if (match_pattern(name, options.accept_env[i])) { 1941 debug2("Setting env %d: %s=%s", s->num_env, name, val); 1942 s->env = xrealloc(s->env, sizeof(*s->env) * 1943 (s->num_env + 1)); 1944 s->env[s->num_env].name = name; 1945 s->env[s->num_env].val = val; 1946 s->num_env++; 1947 return (1); 1948 } 1949 } 1950 debug2("Ignoring env request %s: disallowed name", name); 1951 1952 fail: 1953 xfree(name); 1954 xfree(val); 1955 return (0); 1956} 1957 1958static int 1959session_auth_agent_req(Session *s) 1960{ 1961 static int called = 0; 1962 packet_check_eom(); 1963 if (no_agent_forwarding_flag) { 1964 debug("session_auth_agent_req: no_agent_forwarding_flag"); 1965 return 0; 1966 } 1967 if (called) { 1968 return 0; 1969 } else { 1970 called = 1; 1971 return auth_input_request_forwarding(s->pw); 1972 } 1973} 1974 1975int 1976session_input_channel_req(Channel *c, const char *rtype) 1977{ 1978 int success = 0; 1979 Session *s; 1980 1981 if ((s = session_by_channel(c->self)) == NULL) { 1982 logit("session_input_channel_req: no session %d req %.100s", 1983 c->self, rtype); 1984 return 0; 1985 } 1986 debug("session_input_channel_req: session %d req %s", s->self, rtype); 1987 1988 /* 1989 * a session is in LARVAL state until a shell, a command 1990 * or a subsystem is executed 1991 */ 1992 if (c->type == SSH_CHANNEL_LARVAL) { 1993 if (strcmp(rtype, "shell") == 0) { 1994 success = session_shell_req(s); 1995 } else if (strcmp(rtype, "exec") == 0) { 1996 success = session_exec_req(s); 1997 } else if (strcmp(rtype, "pty-req") == 0) { 1998 success = session_pty_req(s); 1999 } else if (strcmp(rtype, "x11-req") == 0) { 2000 success = session_x11_req(s); 2001 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { 2002 success = session_auth_agent_req(s); 2003 } else if (strcmp(rtype, "subsystem") == 0) { 2004 success = session_subsystem_req(s); 2005 } else if (strcmp(rtype, "env") == 0) { 2006 success = session_env_req(s); 2007 } 2008 } 2009 if (strcmp(rtype, "window-change") == 0) { 2010 success = session_window_change_req(s); 2011 } else if (strcmp(rtype, "break") == 0) { 2012 success = session_break_req(s); 2013 } 2014 2015 return success; 2016} 2017 2018void 2019session_set_fds(Session *s, int fdin, int fdout, int fderr) 2020{ 2021 if (!compat20) 2022 fatal("session_set_fds: called for proto != 2.0"); 2023 /* 2024 * now that have a child and a pipe to the child, 2025 * we can activate our channel and register the fd's 2026 */ 2027 if (s->chanid == -1) 2028 fatal("no channel for session %d", s->self); 2029 channel_set_fds(s->chanid, 2030 fdout, fdin, fderr, 2031 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, 2032 1, 2033 CHAN_SES_WINDOW_DEFAULT); 2034} 2035 2036/* 2037 * Function to perform pty cleanup. Also called if we get aborted abnormally 2038 * (e.g., due to a dropped connection). 2039 */ 2040void 2041session_pty_cleanup2(Session *s) 2042{ 2043 if (s == NULL) { 2044 error("session_pty_cleanup: no session"); 2045 return; 2046 } 2047 if (s->ttyfd == -1) 2048 return; 2049 2050 debug("session_pty_cleanup: session %d release %s", s->self, s->tty); 2051 2052 /* Record that the user has logged out. */ 2053 if (s->pid != 0) 2054 record_logout(s->pid, s->tty, s->pw->pw_name); 2055 2056 /* Release the pseudo-tty. */ 2057 if (getuid() == 0) 2058 pty_release(s->tty); 2059 2060 /* 2061 * Close the server side of the socket pairs. We must do this after 2062 * the pty cleanup, so that another process doesn't get this pty 2063 * while we're still cleaning up. 2064 */ 2065 if (close(s->ptymaster) < 0) 2066 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno)); 2067 2068 /* unlink pty from session */ 2069 s->ttyfd = -1; 2070} 2071 2072void 2073session_pty_cleanup(Session *s) 2074{ 2075 PRIVSEP(session_pty_cleanup2(s)); 2076} 2077 2078static char * 2079sig2name(int sig) 2080{ 2081#define SSH_SIG(x) if (sig == SIG ## x) return #x 2082 SSH_SIG(ABRT); 2083 SSH_SIG(ALRM); 2084 SSH_SIG(FPE); 2085 SSH_SIG(HUP); 2086 SSH_SIG(ILL); 2087 SSH_SIG(INT); 2088 SSH_SIG(KILL); 2089 SSH_SIG(PIPE); 2090 SSH_SIG(QUIT); 2091 SSH_SIG(SEGV); 2092 SSH_SIG(TERM); 2093 SSH_SIG(USR1); 2094 SSH_SIG(USR2); 2095#undef SSH_SIG 2096 return "SIG@openssh.com"; 2097} 2098 2099static void 2100session_exit_message(Session *s, int status) 2101{ 2102 Channel *c; 2103 2104 if ((c = channel_lookup(s->chanid)) == NULL) 2105 fatal("session_exit_message: session %d: no channel %d", 2106 s->self, s->chanid); 2107 debug("session_exit_message: session %d channel %d pid %ld", 2108 s->self, s->chanid, (long)s->pid); 2109 2110 if (WIFEXITED(status)) { 2111 channel_request_start(s->chanid, "exit-status", 0); 2112 packet_put_int(WEXITSTATUS(status)); 2113 packet_send(); 2114 } else if (WIFSIGNALED(status)) { 2115 channel_request_start(s->chanid, "exit-signal", 0); 2116 packet_put_cstring(sig2name(WTERMSIG(status))); 2117#ifdef WCOREDUMP 2118 packet_put_char(WCOREDUMP(status)); 2119#else /* WCOREDUMP */ 2120 packet_put_char(0); 2121#endif /* WCOREDUMP */ 2122 packet_put_cstring(""); 2123 packet_put_cstring(""); 2124 packet_send(); 2125 } else { 2126 /* Some weird exit cause. Just exit. */ 2127 packet_disconnect("wait returned status %04x.", status); 2128 } 2129 2130 /* disconnect channel */ 2131 debug("session_exit_message: release channel %d", s->chanid); 2132 channel_cancel_cleanup(s->chanid); 2133 /* 2134 * emulate a write failure with 'chan_write_failed', nobody will be 2135 * interested in data we write. 2136 * Note that we must not call 'chan_read_failed', since there could 2137 * be some more data waiting in the pipe. 2138 */ 2139 if (c->ostate != CHAN_OUTPUT_CLOSED) 2140 chan_write_failed(c); 2141 s->chanid = -1; 2142} 2143 2144void 2145session_close(Session *s) 2146{ 2147 int i; 2148 2149 debug("session_close: session %d pid %ld", s->self, (long)s->pid); 2150 if (s->ttyfd != -1) 2151 session_pty_cleanup(s); 2152 if (s->term) 2153 xfree(s->term); 2154 if (s->display) 2155 xfree(s->display); 2156 if (s->auth_display) 2157 xfree(s->auth_display); 2158 if (s->auth_data) 2159 xfree(s->auth_data); 2160 if (s->auth_proto) 2161 xfree(s->auth_proto); 2162 s->used = 0; 2163 for (i = 0; i < s->num_env; i++) { 2164 xfree(s->env[i].name); 2165 xfree(s->env[i].val); 2166 } 2167 if (s->env != NULL) 2168 xfree(s->env); 2169 session_proctitle(s); 2170} 2171 2172void 2173session_close_by_pid(pid_t pid, int status) 2174{ 2175 Session *s = session_by_pid(pid); 2176 if (s == NULL) { 2177 debug("session_close_by_pid: no session for pid %ld", 2178 (long)pid); 2179 return; 2180 } 2181 if (s->chanid != -1) 2182 session_exit_message(s, status); 2183 session_close(s); 2184} 2185 2186/* 2187 * this is called when a channel dies before 2188 * the session 'child' itself dies 2189 */ 2190void 2191session_close_by_channel(int id, void *arg) 2192{ 2193 Session *s = session_by_channel(id); 2194 if (s == NULL) { 2195 debug("session_close_by_channel: no session for id %d", id); 2196 return; 2197 } 2198 debug("session_close_by_channel: channel %d child %ld", 2199 id, (long)s->pid); 2200 if (s->pid != 0) { 2201 debug("session_close_by_channel: channel %d: has child", id); 2202 /* 2203 * delay detach of session, but release pty, since 2204 * the fd's to the child are already closed 2205 */ 2206 if (s->ttyfd != -1) 2207 session_pty_cleanup(s); 2208 return; 2209 } 2210 /* detach by removing callback */ 2211 channel_cancel_cleanup(s->chanid); 2212 s->chanid = -1; 2213 session_close(s); 2214} 2215 2216void 2217session_destroy_all(void (*closefunc)(Session *)) 2218{ 2219 int i; 2220 for (i = 0; i < MAX_SESSIONS; i++) { 2221 Session *s = &sessions[i]; 2222 if (s->used) { 2223 if (closefunc != NULL) 2224 closefunc(s); 2225 else 2226 session_close(s); 2227 } 2228 } 2229} 2230 2231static char * 2232session_tty_list(void) 2233{ 2234 static char buf[1024]; 2235 int i; 2236 char *cp; 2237 2238 buf[0] = '\0'; 2239 for (i = 0; i < MAX_SESSIONS; i++) { 2240 Session *s = &sessions[i]; 2241 if (s->used && s->ttyfd != -1) { 2242 2243 if (strncmp(s->tty, "/dev/", 5) != 0) { 2244 cp = strrchr(s->tty, '/'); 2245 cp = (cp == NULL) ? s->tty : cp + 1; 2246 } else 2247 cp = s->tty + 5; 2248 2249 if (buf[0] != '\0') 2250 strlcat(buf, ",", sizeof buf); 2251 strlcat(buf, cp, sizeof buf); 2252 } 2253 } 2254 if (buf[0] == '\0') 2255 strlcpy(buf, "notty", sizeof buf); 2256 return buf; 2257} 2258 2259void 2260session_proctitle(Session *s) 2261{ 2262 if (s->pw == NULL) 2263 error("no user for session %d", s->self); 2264 else 2265 setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); 2266} 2267 2268int 2269session_setup_x11fwd(Session *s) 2270{ 2271 struct stat st; 2272 char display[512], auth_display[512]; 2273 char hostname[MAXHOSTNAMELEN]; 2274 2275 if (no_x11_forwarding_flag) { 2276 packet_send_debug("X11 forwarding disabled in user configuration file."); 2277 return 0; 2278 } 2279 if (!options.x11_forwarding) { 2280 debug("X11 forwarding disabled in server configuration file."); 2281 return 0; 2282 } 2283 if (!options.xauth_location || 2284 (stat(options.xauth_location, &st) == -1)) { 2285 packet_send_debug("No xauth program; cannot forward with spoofing."); 2286 return 0; 2287 } 2288 if (options.use_login) { 2289 packet_send_debug("X11 forwarding disabled; " 2290 "not compatible with UseLogin=yes."); 2291 return 0; 2292 } 2293 if (s->display != NULL) { 2294 debug("X11 display already set."); 2295 return 0; 2296 } 2297 if (x11_create_display_inet(options.x11_display_offset, 2298 options.x11_use_localhost, s->single_connection, 2299 &s->display_number) == -1) { 2300 debug("x11_create_display_inet failed."); 2301 return 0; 2302 } 2303 2304 /* Set up a suitable value for the DISPLAY variable. */ 2305 if (gethostname(hostname, sizeof(hostname)) < 0) 2306 fatal("gethostname: %.100s", strerror(errno)); 2307 /* 2308 * auth_display must be used as the displayname when the 2309 * authorization entry is added with xauth(1). This will be 2310 * different than the DISPLAY string for localhost displays. 2311 */ 2312 if (options.x11_use_localhost) { 2313 snprintf(display, sizeof display, "localhost:%u.%u", 2314 s->display_number, s->screen); 2315 snprintf(auth_display, sizeof auth_display, "unix:%u.%u", 2316 s->display_number, s->screen); 2317 s->display = xstrdup(display); 2318 s->auth_display = xstrdup(auth_display); 2319 } else { 2320#ifdef IPADDR_IN_DISPLAY 2321 struct hostent *he; 2322 struct in_addr my_addr; 2323 2324 he = gethostbyname(hostname); 2325 if (he == NULL) { 2326 error("Can't get IP address for X11 DISPLAY."); 2327 packet_send_debug("Can't get IP address for X11 DISPLAY."); 2328 return 0; 2329 } 2330 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); 2331 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr), 2332 s->display_number, s->screen); 2333#else 2334 snprintf(display, sizeof display, "%.400s:%u.%u", hostname, 2335 s->display_number, s->screen); 2336#endif 2337 s->display = xstrdup(display); 2338 s->auth_display = xstrdup(display); 2339 } 2340 2341 return 1; 2342} 2343 2344static void 2345do_authenticated2(Authctxt *authctxt) 2346{ 2347 server_loop2(authctxt); 2348} 2349 2350void 2351do_cleanup(Authctxt *authctxt) 2352{ 2353 static int called = 0; 2354 2355 debug("do_cleanup"); 2356 2357 /* no cleanup if we're in the child for login shell */ 2358 if (is_child) 2359 return; 2360 2361 /* avoid double cleanup */ 2362 if (called) 2363 return; 2364 called = 1; 2365 2366 if (authctxt == NULL) 2367 return; 2368#ifdef KRB5 2369 if (options.kerberos_ticket_cleanup && 2370 authctxt->krb5_ctx) 2371 krb5_cleanup_proc(authctxt); 2372#endif 2373 2374#ifdef GSSAPI 2375 if (compat20 && options.gss_cleanup_creds) 2376 ssh_gssapi_cleanup_creds(); 2377#endif 2378 2379#ifdef USE_PAM 2380 if (options.use_pam) { 2381 sshpam_cleanup(); 2382 sshpam_thread_cleanup(); 2383 } 2384#endif 2385 2386 /* remove agent socket */ 2387 auth_sock_cleanup_proc(authctxt->pw); 2388 2389 /* 2390 * Cleanup ptys/utmp only if privsep is disabled, 2391 * or if running in monitor. 2392 */ 2393 if (!use_privsep || mm_is_monitor()) 2394 session_destroy_all(session_pty_cleanup2); 2395} 2396