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[openssh-git.git] / session.c
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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 1.186 2005/07/25 11:59:40 markus Exp $");
37
38 #include "ssh.h"
39 #include "ssh1.h"
40 #include "ssh2.h"
41 #include "xmalloc.h"
42 #include "sshpty.h"
43 #include "packet.h"
44 #include "buffer.h"
45 #include "match.h"
46 #include "uidswap.h"
47 #include "compat.h"
48 #include "channels.h"
49 #include "bufaux.h"
50 #include "auth.h"
51 #include "auth-options.h"
52 #include "pathnames.h"
53 #include "log.h"
54 #include "servconf.h"
55 #include "sshlogin.h"
56 #include "serverloop.h"
57 #include "canohost.h"
58 #include "session.h"
59 #include "kex.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 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 == COMP_NONE) {
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 */
381 void
382 do_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 */
529 void
530 do_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
629 static void
630 do_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 */
660 void
661 do_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 */
697 void
698 do_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 */
750 void
751 do_motd(void)
752 {
753 FILE *f;
754 char buf[256];
755
756 if (options.print_motd) {
757 #ifdef HAVE_LOGIN_CAP
758 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
759 "/etc/motd"), "r");
760 #else
761 f = fopen("/etc/motd", "r");
762 #endif
763 if (f) {
764 while (fgets(buf, sizeof(buf), f))
765 fputs(buf, stdout);
766 fclose(f);
767 }
768 }
769 }
770
771
772 /*
773 * Check for quiet login, either .hushlogin or command given.
774 */
775 int
776 check_quietlogin(Session *s, const char *command)
777 {
778 char buf[256];
779 struct passwd *pw = s->pw;
780 struct stat st;
781
782 /* Return 1 if .hushlogin exists or a command given. */
783 if (command != NULL)
784 return 1;
785 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
786 #ifdef HAVE_LOGIN_CAP
787 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
788 return 1;
789 #else
790 if (stat(buf, &st) >= 0)
791 return 1;
792 #endif
793 return 0;
794 }
795
796 /*
797 * Sets the value of the given variable in the environment. If the variable
798 * already exists, its value is overriden.
799 */
800 void
801 child_set_env(char ***envp, u_int *envsizep, const char *name,
802 const char *value)
803 {
804 char **env;
805 u_int envsize;
806 u_int i, namelen;
807
808 /*
809 * If we're passed an uninitialized list, allocate a single null
810 * entry before continuing.
811 */
812 if (*envp == NULL && *envsizep == 0) {
813 *envp = xmalloc(sizeof(char *));
814 *envp[0] = NULL;
815 *envsizep = 1;
816 }
817
818 /*
819 * Find the slot where the value should be stored. If the variable
820 * already exists, we reuse the slot; otherwise we append a new slot
821 * at the end of the array, expanding if necessary.
822 */
823 env = *envp;
824 namelen = strlen(name);
825 for (i = 0; env[i]; i++)
826 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
827 break;
828 if (env[i]) {
829 /* Reuse the slot. */
830 xfree(env[i]);
831 } else {
832 /* New variable. Expand if necessary. */
833 envsize = *envsizep;
834 if (i >= envsize - 1) {
835 if (envsize >= 1000)
836 fatal("child_set_env: too many env vars");
837 envsize += 50;
838 env = (*envp) = xrealloc(env, envsize * sizeof(char *));
839 *envsizep = envsize;
840 }
841 /* Need to set the NULL pointer at end of array beyond the new slot. */
842 env[i + 1] = NULL;
843 }
844
845 /* Allocate space and format the variable in the appropriate slot. */
846 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
847 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
848 }
849
850 /*
851 * Reads environment variables from the given file and adds/overrides them
852 * into the environment. If the file does not exist, this does nothing.
853 * Otherwise, it must consist of empty lines, comments (line starts with '#')
854 * and assignments of the form name=value. No other forms are allowed.
855 */
856 static void
857 read_environment_file(char ***env, u_int *envsize,
858 const char *filename)
859 {
860 FILE *f;
861 char buf[4096];
862 char *cp, *value;
863 u_int lineno = 0;
864
865 f = fopen(filename, "r");
866 if (!f)
867 return;
868
869 while (fgets(buf, sizeof(buf), f)) {
870 if (++lineno > 1000)
871 fatal("Too many lines in environment file %s", filename);
872 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
873 ;
874 if (!*cp || *cp == '#' || *cp == '\n')
875 continue;
876 if (strchr(cp, '\n'))
877 *strchr(cp, '\n') = '\0';
878 value = strchr(cp, '=');
879 if (value == NULL) {
880 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
881 filename);
882 continue;
883 }
884 /*
885 * Replace the equals sign by nul, and advance value to
886 * the value string.
887 */
888 *value = '\0';
889 value++;
890 child_set_env(env, envsize, cp, value);
891 }
892 fclose(f);
893 }
894
895 #ifdef HAVE_ETC_DEFAULT_LOGIN
896 /*
897 * Return named variable from specified environment, or NULL if not present.
898 */
899 static char *
900 child_get_env(char **env, const char *name)
901 {
902 int i;
903 size_t len;
904
905 len = strlen(name);
906 for (i=0; env[i] != NULL; i++)
907 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
908 return(env[i] + len + 1);
909 return NULL;
910 }
911
912 /*
913 * Read /etc/default/login.
914 * We pick up the PATH (or SUPATH for root) and UMASK.
915 */
916 static void
917 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
918 {
919 char **tmpenv = NULL, *var;
920 u_int i, tmpenvsize = 0;
921 u_long mask;
922
923 /*
924 * We don't want to copy the whole file to the child's environment,
925 * so we use a temporary environment and copy the variables we're
926 * interested in.
927 */
928 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
929
930 if (tmpenv == NULL)
931 return;
932
933 if (uid == 0)
934 var = child_get_env(tmpenv, "SUPATH");
935 else
936 var = child_get_env(tmpenv, "PATH");
937 if (var != NULL)
938 child_set_env(env, envsize, "PATH", var);
939
940 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
941 if (sscanf(var, "%5lo", &mask) == 1)
942 umask((mode_t)mask);
943
944 for (i = 0; tmpenv[i] != NULL; i++)
945 xfree(tmpenv[i]);
946 xfree(tmpenv);
947 }
948 #endif /* HAVE_ETC_DEFAULT_LOGIN */
949
950 void
951 copy_environment(char **source, char ***env, u_int *envsize)
952 {
953 char *var_name, *var_val;
954 int i;
955
956 if (source == NULL)
957 return;
958
959 for(i = 0; source[i] != NULL; i++) {
960 var_name = xstrdup(source[i]);
961 if ((var_val = strstr(var_name, "=")) == NULL) {
962 xfree(var_name);
963 continue;
964 }
965 *var_val++ = '\0';
966
967 debug3("Copy environment: %s=%s", var_name, var_val);
968 child_set_env(env, envsize, var_name, var_val);
969
970 xfree(var_name);
971 }
972 }
973
974 static char **
975 do_setup_env(Session *s, const char *shell)
976 {
977 char buf[256];
978 u_int i, envsize;
979 char **env, *laddr, *path = NULL;
980 struct passwd *pw = s->pw;
981
982 /* Initialize the environment. */
983 envsize = 100;
984 env = xmalloc(envsize * sizeof(char *));
985 env[0] = NULL;
986
987 #ifdef HAVE_CYGWIN
988 /*
989 * The Windows environment contains some setting which are
990 * important for a running system. They must not be dropped.
991 */
992 {
993 char **p;
994
995 p = fetch_windows_environment();
996 copy_environment(p, &env, &envsize);
997 free_windows_environment(p);
998 }
999 #endif
1000
1001 #ifdef GSSAPI
1002 /* Allow any GSSAPI methods that we've used to alter
1003 * the childs environment as they see fit
1004 */
1005 ssh_gssapi_do_child(&env, &envsize);
1006 #endif
1007
1008 if (!options.use_login) {
1009 /* Set basic environment. */
1010 for (i = 0; i < s->num_env; i++)
1011 child_set_env(&env, &envsize, s->env[i].name,
1012 s->env[i].val);
1013
1014 child_set_env(&env, &envsize, "USER", pw->pw_name);
1015 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1016 #ifdef _AIX
1017 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1018 #endif
1019 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1020 #ifdef HAVE_LOGIN_CAP
1021 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1022 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1023 else
1024 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1025 #else /* HAVE_LOGIN_CAP */
1026 # ifndef HAVE_CYGWIN
1027 /*
1028 * There's no standard path on Windows. The path contains
1029 * important components pointing to the system directories,
1030 * needed for loading shared libraries. So the path better
1031 * remains intact here.
1032 */
1033 # ifdef HAVE_ETC_DEFAULT_LOGIN
1034 read_etc_default_login(&env, &envsize, pw->pw_uid);
1035 path = child_get_env(env, "PATH");
1036 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1037 if (path == NULL || *path == '\0') {
1038 child_set_env(&env, &envsize, "PATH",
1039 s->pw->pw_uid == 0 ?
1040 SUPERUSER_PATH : _PATH_STDPATH);
1041 }
1042 # endif /* HAVE_CYGWIN */
1043 #endif /* HAVE_LOGIN_CAP */
1044
1045 snprintf(buf, sizeof buf, "%.200s/%.50s",
1046 _PATH_MAILDIR, pw->pw_name);
1047 child_set_env(&env, &envsize, "MAIL", buf);
1048
1049 /* Normal systems set SHELL by default. */
1050 child_set_env(&env, &envsize, "SHELL", shell);
1051 }
1052 if (getenv("TZ"))
1053 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1054
1055 /* Set custom environment options from RSA authentication. */
1056 if (!options.use_login) {
1057 while (custom_environment) {
1058 struct envstring *ce = custom_environment;
1059 char *str = ce->s;
1060
1061 for (i = 0; str[i] != '=' && str[i]; i++)
1062 ;
1063 if (str[i] == '=') {
1064 str[i] = 0;
1065 child_set_env(&env, &envsize, str, str + i + 1);
1066 }
1067 custom_environment = ce->next;
1068 xfree(ce->s);
1069 xfree(ce);
1070 }
1071 }
1072
1073 /* SSH_CLIENT deprecated */
1074 snprintf(buf, sizeof buf, "%.50s %d %d",
1075 get_remote_ipaddr(), get_remote_port(), get_local_port());
1076 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1077
1078 laddr = get_local_ipaddr(packet_get_connection_in());
1079 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1080 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1081 xfree(laddr);
1082 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1083
1084 if (s->ttyfd != -1)
1085 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1086 if (s->term)
1087 child_set_env(&env, &envsize, "TERM", s->term);
1088 if (s->display)
1089 child_set_env(&env, &envsize, "DISPLAY", s->display);
1090 if (original_command)
1091 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1092 original_command);
1093
1094 #ifdef _UNICOS
1095 if (cray_tmpdir[0] != '\0')
1096 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1097 #endif /* _UNICOS */
1098
1099 /*
1100 * Since we clear KRB5CCNAME at startup, if it's set now then it
1101 * must have been set by a native authentication method (eg AIX or
1102 * SIA), so copy it to the child.
1103 */
1104 {
1105 char *cp;
1106
1107 if ((cp = getenv("KRB5CCNAME")) != NULL)
1108 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1109 }
1110
1111 #ifdef _AIX
1112 {
1113 char *cp;
1114
1115 if ((cp = getenv("AUTHSTATE")) != NULL)
1116 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1117 read_environment_file(&env, &envsize, "/etc/environment");
1118 }
1119 #endif
1120 #ifdef KRB5
1121 if (s->authctxt->krb5_ccname)
1122 child_set_env(&env, &envsize, "KRB5CCNAME",
1123 s->authctxt->krb5_ccname);
1124 #endif
1125 #ifdef USE_PAM
1126 /*
1127 * Pull in any environment variables that may have
1128 * been set by PAM.
1129 */
1130 if (options.use_pam) {
1131 char **p;
1132
1133 p = fetch_pam_child_environment();
1134 copy_environment(p, &env, &envsize);
1135 free_pam_environment(p);
1136
1137 p = fetch_pam_environment();
1138 copy_environment(p, &env, &envsize);
1139 free_pam_environment(p);
1140 }
1141 #endif /* USE_PAM */
1142
1143 if (auth_sock_name != NULL)
1144 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1145 auth_sock_name);
1146
1147 /* read $HOME/.ssh/environment. */
1148 if (options.permit_user_env && !options.use_login) {
1149 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1150 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1151 read_environment_file(&env, &envsize, buf);
1152 }
1153 if (debug_flag) {
1154 /* dump the environment */
1155 fprintf(stderr, "Environment:\n");
1156 for (i = 0; env[i]; i++)
1157 fprintf(stderr, " %.200s\n", env[i]);
1158 }
1159 return env;
1160 }
1161
1162 /*
1163 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1164 * first in this order).
1165 */
1166 static void
1167 do_rc_files(Session *s, const char *shell)
1168 {
1169 FILE *f = NULL;
1170 char cmd[1024];
1171 int do_xauth;
1172 struct stat st;
1173
1174 do_xauth =
1175 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1176
1177 /* ignore _PATH_SSH_USER_RC for subsystems */
1178 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1179 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1180 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1181 if (debug_flag)
1182 fprintf(stderr, "Running %s\n", cmd);
1183 f = popen(cmd, "w");
1184 if (f) {
1185 if (do_xauth)
1186 fprintf(f, "%s %s\n", s->auth_proto,
1187 s->auth_data);
1188 pclose(f);
1189 } else
1190 fprintf(stderr, "Could not run %s\n",
1191 _PATH_SSH_USER_RC);
1192 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1193 if (debug_flag)
1194 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1195 _PATH_SSH_SYSTEM_RC);
1196 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1197 if (f) {
1198 if (do_xauth)
1199 fprintf(f, "%s %s\n", s->auth_proto,
1200 s->auth_data);
1201 pclose(f);
1202 } else
1203 fprintf(stderr, "Could not run %s\n",
1204 _PATH_SSH_SYSTEM_RC);
1205 } else if (do_xauth && options.xauth_location != NULL) {
1206 /* Add authority data to .Xauthority if appropriate. */
1207 if (debug_flag) {
1208 fprintf(stderr,
1209 "Running %.500s remove %.100s\n",
1210 options.xauth_location, s->auth_display);
1211 fprintf(stderr,
1212 "%.500s add %.100s %.100s %.100s\n",
1213 options.xauth_location, s->auth_display,
1214 s->auth_proto, s->auth_data);
1215 }
1216 snprintf(cmd, sizeof cmd, "%s -q -",
1217 options.xauth_location);
1218 f = popen(cmd, "w");
1219 if (f) {
1220 fprintf(f, "remove %s\n",
1221 s->auth_display);
1222 fprintf(f, "add %s %s %s\n",
1223 s->auth_display, s->auth_proto,
1224 s->auth_data);
1225 pclose(f);
1226 } else {
1227 fprintf(stderr, "Could not run %s\n",
1228 cmd);
1229 }
1230 }
1231 }
1232
1233 static void
1234 do_nologin(struct passwd *pw)
1235 {
1236 FILE *f = NULL;
1237 char buf[1024];
1238
1239 #ifdef HAVE_LOGIN_CAP
1240 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1241 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1242 _PATH_NOLOGIN), "r");
1243 #else
1244 if (pw->pw_uid)
1245 f = fopen(_PATH_NOLOGIN, "r");
1246 #endif
1247 if (f) {
1248 /* /etc/nologin exists. Print its contents and exit. */
1249 logit("User %.100s not allowed because %s exists",
1250 pw->pw_name, _PATH_NOLOGIN);
1251 while (fgets(buf, sizeof(buf), f))
1252 fputs(buf, stderr);
1253 fclose(f);
1254 fflush(NULL);
1255 exit(254);
1256 }
1257 }
1258
1259 /* Set login name, uid, gid, and groups. */
1260 void
1261 do_setusercontext(struct passwd *pw)
1262 {
1263 #ifndef HAVE_CYGWIN
1264 if (getuid() == 0 || geteuid() == 0)
1265 #endif /* HAVE_CYGWIN */
1266 {
1267
1268 #ifdef HAVE_SETPCRED
1269 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1270 fatal("Failed to set process credentials");
1271 #endif /* HAVE_SETPCRED */
1272 #ifdef HAVE_LOGIN_CAP
1273 # ifdef __bsdi__
1274 setpgid(0, 0);
1275 # endif
1276 #ifdef GSSAPI
1277 if (options.gss_authentication) {
1278 temporarily_use_uid(pw);
1279 ssh_gssapi_storecreds();
1280 restore_uid();
1281 }
1282 #endif
1283 # ifdef USE_PAM
1284 if (options.use_pam) {
1285 do_pam_session();
1286 do_pam_setcred(0);
1287 }
1288 # endif /* USE_PAM */
1289 if (setusercontext(lc, pw, pw->pw_uid,
1290 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1291 perror("unable to set user context");
1292 exit(1);
1293 }
1294 #else
1295 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1296 /* Sets login uid for accounting */
1297 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1298 error("setluid: %s", strerror(errno));
1299 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1300
1301 if (setlogin(pw->pw_name) < 0)
1302 error("setlogin failed: %s", strerror(errno));
1303 if (setgid(pw->pw_gid) < 0) {
1304 perror("setgid");
1305 exit(1);
1306 }
1307 /* Initialize the group list. */
1308 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1309 perror("initgroups");
1310 exit(1);
1311 }
1312 endgrent();
1313 #ifdef GSSAPI
1314 if (options.gss_authentication) {
1315 temporarily_use_uid(pw);
1316 ssh_gssapi_storecreds();
1317 restore_uid();
1318 }
1319 #endif
1320 # ifdef USE_PAM
1321 /*
1322 * PAM credentials may take the form of supplementary groups.
1323 * These will have been wiped by the above initgroups() call.
1324 * Reestablish them here.
1325 */
1326 if (options.use_pam) {
1327 do_pam_session();
1328 do_pam_setcred(0);
1329 }
1330 # endif /* USE_PAM */
1331 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1332 irix_setusercontext(pw);
1333 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1334 # ifdef _AIX
1335 aix_usrinfo(pw);
1336 # endif /* _AIX */
1337 /* Permanently switch to the desired uid. */
1338 permanently_set_uid(pw);
1339 #endif
1340 }
1341
1342 #ifdef HAVE_CYGWIN
1343 if (is_winnt)
1344 #endif
1345 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1346 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1347 }
1348
1349 static void
1350 do_pwchange(Session *s)
1351 {
1352 fflush(NULL);
1353 fprintf(stderr, "WARNING: Your password has expired.\n");
1354 if (s->ttyfd != -1) {
1355 fprintf(stderr,
1356 "You must change your password now and login again!\n");
1357 #ifdef PASSWD_NEEDS_USERNAME
1358 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1359 (char *)NULL);
1360 #else
1361 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1362 #endif
1363 perror("passwd");
1364 } else {
1365 fprintf(stderr,
1366 "Password change required but no TTY available.\n");
1367 }
1368 exit(1);
1369 }
1370
1371 static void
1372 launch_login(struct passwd *pw, const char *hostname)
1373 {
1374 /* Launch login(1). */
1375
1376 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1377 #ifdef xxxLOGIN_NEEDS_TERM
1378 (s->term ? s->term : "unknown"),
1379 #endif /* LOGIN_NEEDS_TERM */
1380 #ifdef LOGIN_NO_ENDOPT
1381 "-p", "-f", pw->pw_name, (char *)NULL);
1382 #else
1383 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1384 #endif
1385
1386 /* Login couldn't be executed, die. */
1387
1388 perror("login");
1389 exit(1);
1390 }
1391
1392 static void
1393 child_close_fds(void)
1394 {
1395 int i;
1396
1397 if (packet_get_connection_in() == packet_get_connection_out())
1398 close(packet_get_connection_in());
1399 else {
1400 close(packet_get_connection_in());
1401 close(packet_get_connection_out());
1402 }
1403 /*
1404 * Close all descriptors related to channels. They will still remain
1405 * open in the parent.
1406 */
1407 /* XXX better use close-on-exec? -markus */
1408 channel_close_all();
1409
1410 /*
1411 * Close any extra file descriptors. Note that there may still be
1412 * descriptors left by system functions. They will be closed later.
1413 */
1414 endpwent();
1415
1416 /*
1417 * Close any extra open file descriptors so that we don\'t have them
1418 * hanging around in clients. Note that we want to do this after
1419 * initgroups, because at least on Solaris 2.3 it leaves file
1420 * descriptors open.
1421 */
1422 for (i = 3; i < 64; i++)
1423 close(i);
1424 }
1425
1426 /*
1427 * Performs common processing for the child, such as setting up the
1428 * environment, closing extra file descriptors, setting the user and group
1429 * ids, and executing the command or shell.
1430 */
1431 void
1432 do_child(Session *s, const char *command)
1433 {
1434 extern char **environ;
1435 char **env;
1436 char *argv[10];
1437 const char *shell, *shell0, *hostname = NULL;
1438 struct passwd *pw = s->pw;
1439
1440 /* remove hostkey from the child's memory */
1441 destroy_sensitive_data();
1442
1443 /* Force a password change */
1444 if (s->authctxt->force_pwchange) {
1445 do_setusercontext(pw);
1446 child_close_fds();
1447 do_pwchange(s);
1448 exit(1);
1449 }
1450
1451 /* login(1) is only called if we execute the login shell */
1452 if (options.use_login && command != NULL)
1453 options.use_login = 0;
1454
1455 #ifdef _UNICOS
1456 cray_setup(pw->pw_uid, pw->pw_name, command);
1457 #endif /* _UNICOS */
1458
1459 /*
1460 * Login(1) does this as well, and it needs uid 0 for the "-h"
1461 * switch, so we let login(1) to this for us.
1462 */
1463 if (!options.use_login) {
1464 #ifdef HAVE_OSF_SIA
1465 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1466 if (!check_quietlogin(s, command))
1467 do_motd();
1468 #else /* HAVE_OSF_SIA */
1469 do_nologin(pw);
1470 do_setusercontext(pw);
1471 /*
1472 * PAM session modules in do_setusercontext may have
1473 * generated messages, so if this in an interactive
1474 * login then display them too.
1475 */
1476 if (!check_quietlogin(s, command))
1477 display_loginmsg();
1478 #endif /* HAVE_OSF_SIA */
1479 }
1480
1481 #ifdef USE_PAM
1482 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1483 debug3("PAM session not opened, exiting");
1484 display_loginmsg();
1485 exit(254);
1486 }
1487 #endif
1488
1489 /*
1490 * Get the shell from the password data. An empty shell field is
1491 * legal, and means /bin/sh.
1492 */
1493 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1494
1495 /*
1496 * Make sure $SHELL points to the shell from the password file,
1497 * even if shell is overridden from login.conf
1498 */
1499 env = do_setup_env(s, shell);
1500
1501 #ifdef HAVE_LOGIN_CAP
1502 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1503 #endif
1504
1505 /* we have to stash the hostname before we close our socket. */
1506 if (options.use_login)
1507 hostname = get_remote_name_or_ip(utmp_len,
1508 options.use_dns);
1509 /*
1510 * Close the connection descriptors; note that this is the child, and
1511 * the server will still have the socket open, and it is important
1512 * that we do not shutdown it. Note that the descriptors cannot be
1513 * closed before building the environment, as we call
1514 * get_remote_ipaddr there.
1515 */
1516 child_close_fds();
1517
1518 /*
1519 * Must take new environment into use so that .ssh/rc,
1520 * /etc/ssh/sshrc and xauth are run in the proper environment.
1521 */
1522 environ = env;
1523
1524 #if defined(KRB5) && defined(USE_AFS)
1525 /*
1526 * At this point, we check to see if AFS is active and if we have
1527 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1528 * if we can (and need to) extend the ticket into an AFS token. If
1529 * we don't do this, we run into potential problems if the user's
1530 * home directory is in AFS and it's not world-readable.
1531 */
1532
1533 if (options.kerberos_get_afs_token && k_hasafs() &&
1534 (s->authctxt->krb5_ctx != NULL)) {
1535 char cell[64];
1536
1537 debug("Getting AFS token");
1538
1539 k_setpag();
1540
1541 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1542 krb5_afslog(s->authctxt->krb5_ctx,
1543 s->authctxt->krb5_fwd_ccache, cell, NULL);
1544
1545 krb5_afslog_home(s->authctxt->krb5_ctx,
1546 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1547 }
1548 #endif
1549
1550 /* Change current directory to the user\'s home directory. */
1551 if (chdir(pw->pw_dir) < 0) {
1552 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1553 pw->pw_dir, strerror(errno));
1554 #ifdef HAVE_LOGIN_CAP
1555 if (login_getcapbool(lc, "requirehome", 0))
1556 exit(1);
1557 #endif
1558 }
1559
1560 if (!options.use_login)
1561 do_rc_files(s, shell);
1562
1563 /* restore SIGPIPE for child */
1564 signal(SIGPIPE, SIG_DFL);
1565
1566 if (options.use_login) {
1567 launch_login(pw, hostname);
1568 /* NEVERREACHED */
1569 }
1570
1571 /* Get the last component of the shell name. */
1572 if ((shell0 = strrchr(shell, '/')) != NULL)
1573 shell0++;
1574 else
1575 shell0 = shell;
1576
1577 /*
1578 * If we have no command, execute the shell. In this case, the shell
1579 * name to be passed in argv[0] is preceded by '-' to indicate that
1580 * this is a login shell.
1581 */
1582 if (!command) {
1583 char argv0[256];
1584
1585 /* Start the shell. Set initial character to '-'. */
1586 argv0[0] = '-';
1587
1588 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1589 >= sizeof(argv0) - 1) {
1590 errno = EINVAL;
1591 perror(shell);
1592 exit(1);
1593 }
1594
1595 /* Execute the shell. */
1596 argv[0] = argv0;
1597 argv[1] = NULL;
1598 execve(shell, argv, env);
1599
1600 /* Executing the shell failed. */
1601 perror(shell);
1602 exit(1);
1603 }
1604 /*
1605 * Execute the command using the user's shell. This uses the -c
1606 * option to execute the command.
1607 */
1608 argv[0] = (char *) shell0;
1609 argv[1] = "-c";
1610 argv[2] = (char *) command;
1611 argv[3] = NULL;
1612 execve(shell, argv, env);
1613 perror(shell);
1614 exit(1);
1615 }
1616
1617 Session *
1618 session_new(void)
1619 {
1620 int i;
1621 static int did_init = 0;
1622 if (!did_init) {
1623 debug("session_new: init");
1624 for (i = 0; i < MAX_SESSIONS; i++) {
1625 sessions[i].used = 0;
1626 }
1627 did_init = 1;
1628 }
1629 for (i = 0; i < MAX_SESSIONS; i++) {
1630 Session *s = &sessions[i];
1631 if (! s->used) {
1632 memset(s, 0, sizeof(*s));
1633 s->chanid = -1;
1634 s->ptyfd = -1;
1635 s->ttyfd = -1;
1636 s->used = 1;
1637 s->self = i;
1638 s->x11_chanids = NULL;
1639 debug("session_new: session %d", i);
1640 return s;
1641 }
1642 }
1643 return NULL;
1644 }
1645
1646 static void
1647 session_dump(void)
1648 {
1649 int i;
1650 for (i = 0; i < MAX_SESSIONS; i++) {
1651 Session *s = &sessions[i];
1652 debug("dump: used %d session %d %p channel %d pid %ld",
1653 s->used,
1654 s->self,
1655 s,
1656 s->chanid,
1657 (long)s->pid);
1658 }
1659 }
1660
1661 int
1662 session_open(Authctxt *authctxt, int chanid)
1663 {
1664 Session *s = session_new();
1665 debug("session_open: channel %d", chanid);
1666 if (s == NULL) {
1667 error("no more sessions");
1668 return 0;
1669 }
1670 s->authctxt = authctxt;
1671 s->pw = authctxt->pw;
1672 if (s->pw == NULL || !authctxt->valid)
1673 fatal("no user for session %d", s->self);
1674 debug("session_open: session %d: link with channel %d", s->self, chanid);
1675 s->chanid = chanid;
1676 return 1;
1677 }
1678
1679 Session *
1680 session_by_tty(char *tty)
1681 {
1682 int i;
1683 for (i = 0; i < MAX_SESSIONS; i++) {
1684 Session *s = &sessions[i];
1685 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1686 debug("session_by_tty: session %d tty %s", i, tty);
1687 return s;
1688 }
1689 }
1690 debug("session_by_tty: unknown tty %.100s", tty);
1691 session_dump();
1692 return NULL;
1693 }
1694
1695 static Session *
1696 session_by_channel(int id)
1697 {
1698 int i;
1699 for (i = 0; i < MAX_SESSIONS; i++) {
1700 Session *s = &sessions[i];
1701 if (s->used && s->chanid == id) {
1702 debug("session_by_channel: session %d channel %d", i, id);
1703 return s;
1704 }
1705 }
1706 debug("session_by_channel: unknown channel %d", id);
1707 session_dump();
1708 return NULL;
1709 }
1710
1711 static Session *
1712 session_by_x11_channel(int id)
1713 {
1714 int i, j;
1715
1716 for (i = 0; i < MAX_SESSIONS; i++) {
1717 Session *s = &sessions[i];
1718
1719 if (s->x11_chanids == NULL || !s->used)
1720 continue;
1721 for (j = 0; s->x11_chanids[j] != -1; j++) {
1722 if (s->x11_chanids[j] == id) {
1723 debug("session_by_x11_channel: session %d "
1724 "channel %d", s->self, id);
1725 return s;
1726 }
1727 }
1728 }
1729 debug("session_by_x11_channel: unknown channel %d", id);
1730 session_dump();
1731 return NULL;
1732 }
1733
1734 static Session *
1735 session_by_pid(pid_t pid)
1736 {
1737 int i;
1738 debug("session_by_pid: pid %ld", (long)pid);
1739 for (i = 0; i < MAX_SESSIONS; i++) {
1740 Session *s = &sessions[i];
1741 if (s->used && s->pid == pid)
1742 return s;
1743 }
1744 error("session_by_pid: unknown pid %ld", (long)pid);
1745 session_dump();
1746 return NULL;
1747 }
1748
1749 static int
1750 session_window_change_req(Session *s)
1751 {
1752 s->col = packet_get_int();
1753 s->row = packet_get_int();
1754 s->xpixel = packet_get_int();
1755 s->ypixel = packet_get_int();
1756 packet_check_eom();
1757 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1758 return 1;
1759 }
1760
1761 static int
1762 session_pty_req(Session *s)
1763 {
1764 u_int len;
1765 int n_bytes;
1766
1767 if (no_pty_flag) {
1768 debug("Allocating a pty not permitted for this authentication.");
1769 return 0;
1770 }
1771 if (s->ttyfd != -1) {
1772 packet_disconnect("Protocol error: you already have a pty.");
1773 return 0;
1774 }
1775
1776 s->term = packet_get_string(&len);
1777
1778 if (compat20) {
1779 s->col = packet_get_int();
1780 s->row = packet_get_int();
1781 } else {
1782 s->row = packet_get_int();
1783 s->col = packet_get_int();
1784 }
1785 s->xpixel = packet_get_int();
1786 s->ypixel = packet_get_int();
1787
1788 if (strcmp(s->term, "") == 0) {
1789 xfree(s->term);
1790 s->term = NULL;
1791 }
1792
1793 /* Allocate a pty and open it. */
1794 debug("Allocating pty.");
1795 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1796 if (s->term)
1797 xfree(s->term);
1798 s->term = NULL;
1799 s->ptyfd = -1;
1800 s->ttyfd = -1;
1801 error("session_pty_req: session %d alloc failed", s->self);
1802 return 0;
1803 }
1804 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1805
1806 /* for SSH1 the tty modes length is not given */
1807 if (!compat20)
1808 n_bytes = packet_remaining();
1809 tty_parse_modes(s->ttyfd, &n_bytes);
1810
1811 if (!use_privsep)
1812 pty_setowner(s->pw, s->tty);
1813
1814 /* Set window size from the packet. */
1815 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1816
1817 packet_check_eom();
1818 session_proctitle(s);
1819 return 1;
1820 }
1821
1822 static int
1823 session_subsystem_req(Session *s)
1824 {
1825 struct stat st;
1826 u_int len;
1827 int success = 0;
1828 char *cmd, *subsys = packet_get_string(&len);
1829 u_int i;
1830
1831 packet_check_eom();
1832 logit("subsystem request for %.100s", subsys);
1833
1834 for (i = 0; i < options.num_subsystems; i++) {
1835 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1836 cmd = options.subsystem_command[i];
1837 if (stat(cmd, &st) < 0) {
1838 error("subsystem: cannot stat %s: %s", cmd,
1839 strerror(errno));
1840 break;
1841 }
1842 debug("subsystem: exec() %s", cmd);
1843 s->is_subsystem = 1;
1844 do_exec(s, cmd);
1845 success = 1;
1846 break;
1847 }
1848 }
1849
1850 if (!success)
1851 logit("subsystem request for %.100s failed, subsystem not found",
1852 subsys);
1853
1854 xfree(subsys);
1855 return success;
1856 }
1857
1858 static int
1859 session_x11_req(Session *s)
1860 {
1861 int success;
1862
1863 if (s->auth_proto != NULL || s->auth_data != NULL) {
1864 error("session_x11_req: session %d: "
1865 "x11 fowarding already active", s->self);
1866 return 0;
1867 }
1868 s->single_connection = packet_get_char();
1869 s->auth_proto = packet_get_string(NULL);
1870 s->auth_data = packet_get_string(NULL);
1871 s->screen = packet_get_int();
1872 packet_check_eom();
1873
1874 success = session_setup_x11fwd(s);
1875 if (!success) {
1876 xfree(s->auth_proto);
1877 xfree(s->auth_data);
1878 s->auth_proto = NULL;
1879 s->auth_data = NULL;
1880 }
1881 return success;
1882 }
1883
1884 static int
1885 session_shell_req(Session *s)
1886 {
1887 packet_check_eom();
1888 do_exec(s, NULL);
1889 return 1;
1890 }
1891
1892 static int
1893 session_exec_req(Session *s)
1894 {
1895 u_int len;
1896 char *command = packet_get_string(&len);
1897 packet_check_eom();
1898 do_exec(s, command);
1899 xfree(command);
1900 return 1;
1901 }
1902
1903 static int
1904 session_break_req(Session *s)
1905 {
1906
1907 packet_get_int(); /* ignored */
1908 packet_check_eom();
1909
1910 if (s->ttyfd == -1 ||
1911 tcsendbreak(s->ttyfd, 0) < 0)
1912 return 0;
1913 return 1;
1914 }
1915
1916 static int
1917 session_env_req(Session *s)
1918 {
1919 char *name, *val;
1920 u_int name_len, val_len, i;
1921
1922 name = packet_get_string(&name_len);
1923 val = packet_get_string(&val_len);
1924 packet_check_eom();
1925
1926 /* Don't set too many environment variables */
1927 if (s->num_env > 128) {
1928 debug2("Ignoring env request %s: too many env vars", name);
1929 goto fail;
1930 }
1931
1932 for (i = 0; i < options.num_accept_env; i++) {
1933 if (match_pattern(name, options.accept_env[i])) {
1934 debug2("Setting env %d: %s=%s", s->num_env, name, val);
1935 s->env = xrealloc(s->env, sizeof(*s->env) *
1936 (s->num_env + 1));
1937 s->env[s->num_env].name = name;
1938 s->env[s->num_env].val = val;
1939 s->num_env++;
1940 return (1);
1941 }
1942 }
1943 debug2("Ignoring env request %s: disallowed name", name);
1944
1945 fail:
1946 xfree(name);
1947 xfree(val);
1948 return (0);
1949 }
1950
1951 static int
1952 session_auth_agent_req(Session *s)
1953 {
1954 static int called = 0;
1955 packet_check_eom();
1956 if (no_agent_forwarding_flag) {
1957 debug("session_auth_agent_req: no_agent_forwarding_flag");
1958 return 0;
1959 }
1960 if (called) {
1961 return 0;
1962 } else {
1963 called = 1;
1964 return auth_input_request_forwarding(s->pw);
1965 }
1966 }
1967
1968 int
1969 session_input_channel_req(Channel *c, const char *rtype)
1970 {
1971 int success = 0;
1972 Session *s;
1973
1974 if ((s = session_by_channel(c->self)) == NULL) {
1975 logit("session_input_channel_req: no session %d req %.100s",
1976 c->self, rtype);
1977 return 0;
1978 }
1979 debug("session_input_channel_req: session %d req %s", s->self, rtype);
1980
1981 /*
1982 * a session is in LARVAL state until a shell, a command
1983 * or a subsystem is executed
1984 */
1985 if (c->type == SSH_CHANNEL_LARVAL) {
1986 if (strcmp(rtype, "shell") == 0) {
1987 success = session_shell_req(s);
1988 } else if (strcmp(rtype, "exec") == 0) {
1989 success = session_exec_req(s);
1990 } else if (strcmp(rtype, "pty-req") == 0) {
1991 success = session_pty_req(s);
1992 } else if (strcmp(rtype, "x11-req") == 0) {
1993 success = session_x11_req(s);
1994 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1995 success = session_auth_agent_req(s);
1996 } else if (strcmp(rtype, "subsystem") == 0) {
1997 success = session_subsystem_req(s);
1998 } else if (strcmp(rtype, "env") == 0) {
1999 success = session_env_req(s);
2000 }
2001 }
2002 if (strcmp(rtype, "window-change") == 0) {
2003 success = session_window_change_req(s);
2004 } else if (strcmp(rtype, "break") == 0) {
2005 success = session_break_req(s);
2006 }
2007
2008 return success;
2009 }
2010
2011 void
2012 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2013 {
2014 if (!compat20)
2015 fatal("session_set_fds: called for proto != 2.0");
2016 /*
2017 * now that have a child and a pipe to the child,
2018 * we can activate our channel and register the fd's
2019 */
2020 if (s->chanid == -1)
2021 fatal("no channel for session %d", s->self);
2022 channel_set_fds(s->chanid,
2023 fdout, fdin, fderr,
2024 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2025 1,
2026 CHAN_SES_WINDOW_DEFAULT);
2027 }
2028
2029 /*
2030 * Function to perform pty cleanup. Also called if we get aborted abnormally
2031 * (e.g., due to a dropped connection).
2032 */
2033 void
2034 session_pty_cleanup2(Session *s)
2035 {
2036 if (s == NULL) {
2037 error("session_pty_cleanup: no session");
2038 return;
2039 }
2040 if (s->ttyfd == -1)
2041 return;
2042
2043 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2044
2045 /* Record that the user has logged out. */
2046 if (s->pid != 0)
2047 record_logout(s->pid, s->tty, s->pw->pw_name);
2048
2049 /* Release the pseudo-tty. */
2050 if (getuid() == 0)
2051 pty_release(s->tty);
2052
2053 /*
2054 * Close the server side of the socket pairs. We must do this after
2055 * the pty cleanup, so that another process doesn't get this pty
2056 * while we're still cleaning up.
2057 */
2058 if (close(s->ptymaster) < 0)
2059 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2060
2061 /* unlink pty from session */
2062 s->ttyfd = -1;
2063 }
2064
2065 void
2066 session_pty_cleanup(Session *s)
2067 {
2068 PRIVSEP(session_pty_cleanup2(s));
2069 }
2070
2071 static char *
2072 sig2name(int sig)
2073 {
2074 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2075 SSH_SIG(ABRT);
2076 SSH_SIG(ALRM);
2077 SSH_SIG(FPE);
2078 SSH_SIG(HUP);
2079 SSH_SIG(ILL);
2080 SSH_SIG(INT);
2081 SSH_SIG(KILL);
2082 SSH_SIG(PIPE);
2083 SSH_SIG(QUIT);
2084 SSH_SIG(SEGV);
2085 SSH_SIG(TERM);
2086 SSH_SIG(USR1);
2087 SSH_SIG(USR2);
2088 #undef SSH_SIG
2089 return "SIG@openssh.com";
2090 }
2091
2092 static void
2093 session_close_x11(int id)
2094 {
2095 Channel *c;
2096
2097 if ((c = channel_lookup(id)) == NULL) {
2098 debug("session_close_x11: x11 channel %d missing", id);
2099 } else {
2100 /* Detach X11 listener */
2101 debug("session_close_x11: detach x11 channel %d", id);
2102 channel_cancel_cleanup(id);
2103 if (c->ostate != CHAN_OUTPUT_CLOSED)
2104 chan_mark_dead(c);
2105 }
2106 }
2107
2108 static void
2109 session_close_single_x11(int id, void *arg)
2110 {
2111 Session *s;
2112 u_int i;
2113
2114 debug3("session_close_single_x11: channel %d", id);
2115 channel_cancel_cleanup(id);
2116 if ((s = session_by_x11_channel(id)) == NULL)
2117 fatal("session_close_single_x11: no x11 channel %d", id);
2118 for (i = 0; s->x11_chanids[i] != -1; i++) {
2119 debug("session_close_single_x11: session %d: "
2120 "closing channel %d", s->self, s->x11_chanids[i]);
2121 /*
2122 * The channel "id" is already closing, but make sure we
2123 * close all of its siblings.
2124 */
2125 if (s->x11_chanids[i] != id)
2126 session_close_x11(s->x11_chanids[i]);
2127 }
2128 xfree(s->x11_chanids);
2129 s->x11_chanids = NULL;
2130 if (s->display) {
2131 xfree(s->display);
2132 s->display = NULL;
2133 }
2134 if (s->auth_proto) {
2135 xfree(s->auth_proto);
2136 s->auth_proto = NULL;
2137 }
2138 if (s->auth_data) {
2139 xfree(s->auth_data);
2140 s->auth_data = NULL;
2141 }
2142 if (s->auth_display) {
2143 xfree(s->auth_display);
2144 s->auth_display = NULL;
2145 }
2146 }
2147
2148 static void
2149 session_exit_message(Session *s, int status)
2150 {
2151 Channel *c;
2152 u_int i;
2153
2154 if ((c = channel_lookup(s->chanid)) == NULL)
2155 fatal("session_exit_message: session %d: no channel %d",
2156 s->self, s->chanid);
2157 debug("session_exit_message: session %d channel %d pid %ld",
2158 s->self, s->chanid, (long)s->pid);
2159
2160 if (WIFEXITED(status)) {
2161 channel_request_start(s->chanid, "exit-status", 0);
2162 packet_put_int(WEXITSTATUS(status));
2163 packet_send();
2164 } else if (WIFSIGNALED(status)) {
2165 channel_request_start(s->chanid, "exit-signal", 0);
2166 packet_put_cstring(sig2name(WTERMSIG(status)));
2167 #ifdef WCOREDUMP
2168 packet_put_char(WCOREDUMP(status));
2169 #else /* WCOREDUMP */
2170 packet_put_char(0);
2171 #endif /* WCOREDUMP */
2172 packet_put_cstring("");
2173 packet_put_cstring("");
2174 packet_send();
2175 } else {
2176 /* Some weird exit cause. Just exit. */
2177 packet_disconnect("wait returned status %04x.", status);
2178 }
2179
2180 /* disconnect channel */
2181 debug("session_exit_message: release channel %d", s->chanid);
2182 channel_cancel_cleanup(s->chanid);
2183 /*
2184 * emulate a write failure with 'chan_write_failed', nobody will be
2185 * interested in data we write.
2186 * Note that we must not call 'chan_read_failed', since there could
2187 * be some more data waiting in the pipe.
2188 */
2189 if (c->ostate != CHAN_OUTPUT_CLOSED)
2190 chan_write_failed(c);
2191 s->chanid = -1;
2192
2193 /* Close any X11 listeners associated with this session */
2194 if (s->x11_chanids != NULL) {
2195 for (i = 0; s->x11_chanids[i] != -1; i++) {
2196 session_close_x11(s->x11_chanids[i]);
2197 s->x11_chanids[i] = -1;
2198 }
2199 }
2200 }
2201
2202 void
2203 session_close(Session *s)
2204 {
2205 u_int i;
2206
2207 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2208 if (s->ttyfd != -1)
2209 session_pty_cleanup(s);
2210 if (s->term)
2211 xfree(s->term);
2212 if (s->display)
2213 xfree(s->display);
2214 if (s->x11_chanids)
2215 xfree(s->x11_chanids);
2216 if (s->auth_display)
2217 xfree(s->auth_display);
2218 if (s->auth_data)
2219 xfree(s->auth_data);
2220 if (s->auth_proto)
2221 xfree(s->auth_proto);
2222 s->used = 0;
2223 for (i = 0; i < s->num_env; i++) {
2224 xfree(s->env[i].name);
2225 xfree(s->env[i].val);
2226 }
2227 if (s->env != NULL)
2228 xfree(s->env);
2229 session_proctitle(s);
2230 }
2231
2232 void
2233 session_close_by_pid(pid_t pid, int status)
2234 {
2235 Session *s = session_by_pid(pid);
2236 if (s == NULL) {
2237 debug("session_close_by_pid: no session for pid %ld",
2238 (long)pid);
2239 return;
2240 }
2241 if (s->chanid != -1)
2242 session_exit_message(s, status);
2243 session_close(s);
2244 }
2245
2246 /*
2247 * this is called when a channel dies before
2248 * the session 'child' itself dies
2249 */
2250 void
2251 session_close_by_channel(int id, void *arg)
2252 {
2253 Session *s = session_by_channel(id);
2254
2255 if (s == NULL) {
2256 debug("session_close_by_channel: no session for id %d", id);
2257 return;
2258 }
2259 debug("session_close_by_channel: channel %d child %ld",
2260 id, (long)s->pid);
2261 if (s->pid != 0) {
2262 debug("session_close_by_channel: channel %d: has child", id);
2263 /*
2264 * delay detach of session, but release pty, since
2265 * the fd's to the child are already closed
2266 */
2267 if (s->ttyfd != -1)
2268 session_pty_cleanup(s);
2269 return;
2270 }
2271 /* detach by removing callback */
2272 channel_cancel_cleanup(s->chanid);
2273 s->chanid = -1;
2274 session_close(s);
2275 }
2276
2277 void
2278 session_destroy_all(void (*closefunc)(Session *))
2279 {
2280 int i;
2281 for (i = 0; i < MAX_SESSIONS; i++) {
2282 Session *s = &sessions[i];
2283 if (s->used) {
2284 if (closefunc != NULL)
2285 closefunc(s);
2286 else
2287 session_close(s);
2288 }
2289 }
2290 }
2291
2292 static char *
2293 session_tty_list(void)
2294 {
2295 static char buf[1024];
2296 int i;
2297 char *cp;
2298
2299 buf[0] = '\0';
2300 for (i = 0; i < MAX_SESSIONS; i++) {
2301 Session *s = &sessions[i];
2302 if (s->used && s->ttyfd != -1) {
2303
2304 if (strncmp(s->tty, "/dev/", 5) != 0) {
2305 cp = strrchr(s->tty, '/');
2306 cp = (cp == NULL) ? s->tty : cp + 1;
2307 } else
2308 cp = s->tty + 5;
2309
2310 if (buf[0] != '\0')
2311 strlcat(buf, ",", sizeof buf);
2312 strlcat(buf, cp, sizeof buf);
2313 }
2314 }
2315 if (buf[0] == '\0')
2316 strlcpy(buf, "notty", sizeof buf);
2317 return buf;
2318 }
2319
2320 void
2321 session_proctitle(Session *s)
2322 {
2323 if (s->pw == NULL)
2324 error("no user for session %d", s->self);
2325 else
2326 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2327 }
2328
2329 int
2330 session_setup_x11fwd(Session *s)
2331 {
2332 struct stat st;
2333 char display[512], auth_display[512];
2334 char hostname[MAXHOSTNAMELEN];
2335 u_int i;
2336
2337 if (no_x11_forwarding_flag) {
2338 packet_send_debug("X11 forwarding disabled in user configuration file.");
2339 return 0;
2340 }
2341 if (!options.x11_forwarding) {
2342 debug("X11 forwarding disabled in server configuration file.");
2343 return 0;
2344 }
2345 if (!options.xauth_location ||
2346 (stat(options.xauth_location, &st) == -1)) {
2347 packet_send_debug("No xauth program; cannot forward with spoofing.");
2348 return 0;
2349 }
2350 if (options.use_login) {
2351 packet_send_debug("X11 forwarding disabled; "
2352 "not compatible with UseLogin=yes.");
2353 return 0;
2354 }
2355 if (s->display != NULL) {
2356 debug("X11 display already set.");
2357 return 0;
2358 }
2359 if (x11_create_display_inet(options.x11_display_offset,
2360 options.x11_use_localhost, s->single_connection,
2361 &s->display_number, &s->x11_chanids) == -1) {
2362 debug("x11_create_display_inet failed.");
2363 return 0;
2364 }
2365 for (i = 0; s->x11_chanids[i] != -1; i++) {
2366 channel_register_cleanup(s->x11_chanids[i],
2367 session_close_single_x11);
2368 }
2369
2370 /* Set up a suitable value for the DISPLAY variable. */
2371 if (gethostname(hostname, sizeof(hostname)) < 0)
2372 fatal("gethostname: %.100s", strerror(errno));
2373 /*
2374 * auth_display must be used as the displayname when the
2375 * authorization entry is added with xauth(1). This will be
2376 * different than the DISPLAY string for localhost displays.
2377 */
2378 if (options.x11_use_localhost) {
2379 snprintf(display, sizeof display, "localhost:%u.%u",
2380 s->display_number, s->screen);
2381 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2382 s->display_number, s->screen);
2383 s->display = xstrdup(display);
2384 s->auth_display = xstrdup(auth_display);
2385 } else {
2386 #ifdef IPADDR_IN_DISPLAY
2387 struct hostent *he;
2388 struct in_addr my_addr;
2389
2390 he = gethostbyname(hostname);
2391 if (he == NULL) {
2392 error("Can't get IP address for X11 DISPLAY.");
2393 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2394 return 0;
2395 }
2396 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2397 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2398 s->display_number, s->screen);
2399 #else
2400 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2401 s->display_number, s->screen);
2402 #endif
2403 s->display = xstrdup(display);
2404 s->auth_display = xstrdup(display);
2405 }
2406
2407 return 1;
2408 }
2409
2410 static void
2411 do_authenticated2(Authctxt *authctxt)
2412 {
2413 server_loop2(authctxt);
2414 }
2415
2416 void
2417 do_cleanup(Authctxt *authctxt)
2418 {
2419 static int called = 0;
2420
2421 debug("do_cleanup");
2422
2423 /* no cleanup if we're in the child for login shell */
2424 if (is_child)
2425 return;
2426
2427 /* avoid double cleanup */
2428 if (called)
2429 return;
2430 called = 1;
2431
2432 if (authctxt == NULL)
2433 return;
2434 #ifdef KRB5
2435 if (options.kerberos_ticket_cleanup &&
2436 authctxt->krb5_ctx)
2437 krb5_cleanup_proc(authctxt);
2438 #endif
2439
2440 #ifdef GSSAPI
2441 if (compat20 && options.gss_cleanup_creds)
2442 ssh_gssapi_cleanup_creds();
2443 #endif
2444
2445 #ifdef USE_PAM
2446 if (options.use_pam) {
2447 sshpam_cleanup();
2448 sshpam_thread_cleanup();
2449 }
2450 #endif
2451
2452 /* remove agent socket */
2453 auth_sock_cleanup_proc(authctxt->pw);
2454
2455 /*
2456 * Cleanup ptys/utmp only if privsep is disabled,
2457 * or if running in monitor.
2458 */
2459 if (!use_privsep || mm_is_monitor())
2460 session_destroy_all(session_pty_cleanup2);
2461 }
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