xref: /freebsd/crypto/openssh/session.c (revision 13de33a5dc2304b13d595d75d48c51793958474f)
1 /* $OpenBSD: session.c,v 1.266 2013/07/19 07:37:48 markus Exp $ */
2 /* $FreeBSD$ */
3 /*
4  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5  *                    All rights reserved
6  *
7  * As far as I am concerned, the code I have written for this software
8  * can be used freely for any purpose.  Any derived versions of this
9  * software must be clearly marked as such, and if the derived work is
10  * incompatible with the protocol description in the RFC file, it must be
11  * called by a name other than "ssh" or "Secure Shell".
12  *
13  * SSH2 support by Markus Friedl.
14  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
15  *
16  * Redistribution and use in source and binary forms, with or without
17  * modification, are permitted provided that the following conditions
18  * are met:
19  * 1. Redistributions of source code must retain the above copyright
20  *    notice, this list of conditions and the following disclaimer.
21  * 2. Redistributions in binary form must reproduce the above copyright
22  *    notice, this list of conditions and the following disclaimer in the
23  *    documentation and/or other materials provided with the distribution.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 #include "includes.h"
38 __RCSID("$FreeBSD$");
39 
40 #include <sys/types.h>
41 #include <sys/param.h>
42 #ifdef HAVE_SYS_STAT_H
43 # include <sys/stat.h>
44 #endif
45 #include <sys/socket.h>
46 #include <sys/un.h>
47 #include <sys/wait.h>
48 
49 #include <arpa/inet.h>
50 
51 #include <errno.h>
52 #include <fcntl.h>
53 #include <grp.h>
54 #ifdef HAVE_PATHS_H
55 #include <paths.h>
56 #endif
57 #include <pwd.h>
58 #include <signal.h>
59 #include <stdarg.h>
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <string.h>
63 #include <unistd.h>
64 
65 #include "openbsd-compat/sys-queue.h"
66 #include "xmalloc.h"
67 #include "ssh.h"
68 #include "ssh1.h"
69 #include "ssh2.h"
70 #include "sshpty.h"
71 #include "packet.h"
72 #include "buffer.h"
73 #include "match.h"
74 #include "uidswap.h"
75 #include "compat.h"
76 #include "channels.h"
77 #include "key.h"
78 #include "cipher.h"
79 #ifdef GSSAPI
80 #include "ssh-gss.h"
81 #endif
82 #include "hostfile.h"
83 #include "auth.h"
84 #include "auth-options.h"
85 #include "authfd.h"
86 #include "pathnames.h"
87 #include "log.h"
88 #include "servconf.h"
89 #include "sshlogin.h"
90 #include "serverloop.h"
91 #include "canohost.h"
92 #include "misc.h"
93 #include "session.h"
94 #include "kex.h"
95 #include "monitor_wrap.h"
96 #include "sftp.h"
97 
98 #if defined(KRB5) && defined(USE_AFS)
99 #include <kafs.h>
100 #endif
101 
102 #ifdef WITH_SELINUX
103 #include <selinux/selinux.h>
104 #endif
105 
106 #define IS_INTERNAL_SFTP(c) \
107 	(!strncmp(c, INTERNAL_SFTP_NAME, sizeof(INTERNAL_SFTP_NAME) - 1) && \
108 	 (c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\0' || \
109 	  c[sizeof(INTERNAL_SFTP_NAME) - 1] == ' ' || \
110 	  c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\t'))
111 
112 /* func */
113 
114 Session *session_new(void);
115 void	session_set_fds(Session *, int, int, int, int, int);
116 void	session_pty_cleanup(Session *);
117 void	session_proctitle(Session *);
118 int	session_setup_x11fwd(Session *);
119 int	do_exec_pty(Session *, const char *);
120 int	do_exec_no_pty(Session *, const char *);
121 int	do_exec(Session *, const char *);
122 void	do_login(Session *, const char *);
123 #ifdef LOGIN_NEEDS_UTMPX
124 static void	do_pre_login(Session *s);
125 #endif
126 void	do_child(Session *, const char *);
127 void	do_motd(void);
128 int	check_quietlogin(Session *, const char *);
129 
130 static void do_authenticated1(Authctxt *);
131 static void do_authenticated2(Authctxt *);
132 
133 static int session_pty_req(Session *);
134 
135 /* import */
136 extern ServerOptions options;
137 extern char *__progname;
138 extern int log_stderr;
139 extern int debug_flag;
140 extern u_int utmp_len;
141 extern int startup_pipe;
142 extern void destroy_sensitive_data(void);
143 extern Buffer loginmsg;
144 
145 /* original command from peer. */
146 const char *original_command = NULL;
147 
148 /* data */
149 static int sessions_first_unused = -1;
150 static int sessions_nalloc = 0;
151 static Session *sessions = NULL;
152 
153 #define SUBSYSTEM_NONE			0
154 #define SUBSYSTEM_EXT			1
155 #define SUBSYSTEM_INT_SFTP		2
156 #define SUBSYSTEM_INT_SFTP_ERROR	3
157 
158 #ifdef HAVE_LOGIN_CAP
159 login_cap_t *lc;
160 #endif
161 
162 static int is_child = 0;
163 
164 /* Name and directory of socket for authentication agent forwarding. */
165 static char *auth_sock_name = NULL;
166 static char *auth_sock_dir = NULL;
167 
168 /* removes the agent forwarding socket */
169 
170 static void
171 auth_sock_cleanup_proc(struct passwd *pw)
172 {
173 	if (auth_sock_name != NULL) {
174 		temporarily_use_uid(pw);
175 		unlink(auth_sock_name);
176 		rmdir(auth_sock_dir);
177 		auth_sock_name = NULL;
178 		restore_uid();
179 	}
180 }
181 
182 static int
183 auth_input_request_forwarding(struct passwd * pw)
184 {
185 	Channel *nc;
186 	int sock = -1;
187 	struct sockaddr_un sunaddr;
188 
189 	if (auth_sock_name != NULL) {
190 		error("authentication forwarding requested twice.");
191 		return 0;
192 	}
193 
194 	/* Temporarily drop privileged uid for mkdir/bind. */
195 	temporarily_use_uid(pw);
196 
197 	/* Allocate a buffer for the socket name, and format the name. */
198 	auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX");
199 
200 	/* Create private directory for socket */
201 	if (mkdtemp(auth_sock_dir) == NULL) {
202 		packet_send_debug("Agent forwarding disabled: "
203 		    "mkdtemp() failed: %.100s", strerror(errno));
204 		restore_uid();
205 		free(auth_sock_dir);
206 		auth_sock_dir = NULL;
207 		goto authsock_err;
208 	}
209 
210 	xasprintf(&auth_sock_name, "%s/agent.%ld",
211 	    auth_sock_dir, (long) getpid());
212 
213 	/* Create the socket. */
214 	sock = socket(AF_UNIX, SOCK_STREAM, 0);
215 	if (sock < 0) {
216 		error("socket: %.100s", strerror(errno));
217 		restore_uid();
218 		goto authsock_err;
219 	}
220 
221 	/* Bind it to the name. */
222 	memset(&sunaddr, 0, sizeof(sunaddr));
223 	sunaddr.sun_family = AF_UNIX;
224 	strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
225 
226 	if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
227 		error("bind: %.100s", strerror(errno));
228 		restore_uid();
229 		goto authsock_err;
230 	}
231 
232 	/* Restore the privileged uid. */
233 	restore_uid();
234 
235 	/* Start listening on the socket. */
236 	if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
237 		error("listen: %.100s", strerror(errno));
238 		goto authsock_err;
239 	}
240 
241 	/*
242 	 * Allocate a channel for the authentication agent socket.
243 	 * Ignore HPN on that one given no improvement expected.
244 	 */
245 	nc = channel_new("auth socket",
246 	    SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
247 	    CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
248 	    0, "auth socket", 1);
249 	nc->path = xstrdup(auth_sock_name);
250 	return 1;
251 
252  authsock_err:
253 	free(auth_sock_name);
254 	if (auth_sock_dir != NULL) {
255 		rmdir(auth_sock_dir);
256 		free(auth_sock_dir);
257 	}
258 	if (sock != -1)
259 		close(sock);
260 	auth_sock_name = NULL;
261 	auth_sock_dir = NULL;
262 	return 0;
263 }
264 
265 static void
266 display_loginmsg(void)
267 {
268 	if (buffer_len(&loginmsg) > 0) {
269 		buffer_append(&loginmsg, "\0", 1);
270 		printf("%s", (char *)buffer_ptr(&loginmsg));
271 		buffer_clear(&loginmsg);
272 	}
273 }
274 
275 void
276 do_authenticated(Authctxt *authctxt)
277 {
278 	setproctitle("%s", authctxt->pw->pw_name);
279 
280 	/* setup the channel layer */
281 	if (no_port_forwarding_flag ||
282 	    (options.allow_tcp_forwarding & FORWARD_LOCAL) == 0)
283 		channel_disable_adm_local_opens();
284 	else
285 		channel_permit_all_opens();
286 
287 	auth_debug_send();
288 
289 	if (compat20)
290 		do_authenticated2(authctxt);
291 	else
292 		do_authenticated1(authctxt);
293 
294 	do_cleanup(authctxt);
295 }
296 
297 /*
298  * Prepares for an interactive session.  This is called after the user has
299  * been successfully authenticated.  During this message exchange, pseudo
300  * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
301  * are requested, etc.
302  */
303 static void
304 do_authenticated1(Authctxt *authctxt)
305 {
306 	Session *s;
307 	char *command;
308 	int success, type, screen_flag;
309 	int enable_compression_after_reply = 0;
310 	u_int proto_len, data_len, dlen, compression_level = 0;
311 
312 	s = session_new();
313 	if (s == NULL) {
314 		error("no more sessions");
315 		return;
316 	}
317 	s->authctxt = authctxt;
318 	s->pw = authctxt->pw;
319 
320 	/*
321 	 * We stay in this loop until the client requests to execute a shell
322 	 * or a command.
323 	 */
324 	for (;;) {
325 		success = 0;
326 
327 		/* Get a packet from the client. */
328 		type = packet_read();
329 
330 		/* Process the packet. */
331 		switch (type) {
332 		case SSH_CMSG_REQUEST_COMPRESSION:
333 			compression_level = packet_get_int();
334 			packet_check_eom();
335 			if (compression_level < 1 || compression_level > 9) {
336 				packet_send_debug("Received invalid compression level %d.",
337 				    compression_level);
338 				break;
339 			}
340 			if (options.compression == COMP_NONE) {
341 				debug2("compression disabled");
342 				break;
343 			}
344 			/* Enable compression after we have responded with SUCCESS. */
345 			enable_compression_after_reply = 1;
346 			success = 1;
347 			break;
348 
349 		case SSH_CMSG_REQUEST_PTY:
350 			success = session_pty_req(s);
351 			break;
352 
353 		case SSH_CMSG_X11_REQUEST_FORWARDING:
354 			s->auth_proto = packet_get_string(&proto_len);
355 			s->auth_data = packet_get_string(&data_len);
356 
357 			screen_flag = packet_get_protocol_flags() &
358 			    SSH_PROTOFLAG_SCREEN_NUMBER;
359 			debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
360 
361 			if (packet_remaining() == 4) {
362 				if (!screen_flag)
363 					debug2("Buggy client: "
364 					    "X11 screen flag missing");
365 				s->screen = packet_get_int();
366 			} else {
367 				s->screen = 0;
368 			}
369 			packet_check_eom();
370 			success = session_setup_x11fwd(s);
371 			if (!success) {
372 				free(s->auth_proto);
373 				free(s->auth_data);
374 				s->auth_proto = NULL;
375 				s->auth_data = NULL;
376 			}
377 			break;
378 
379 		case SSH_CMSG_AGENT_REQUEST_FORWARDING:
380 			if (!options.allow_agent_forwarding ||
381 			    no_agent_forwarding_flag || compat13) {
382 				debug("Authentication agent forwarding not permitted for this authentication.");
383 				break;
384 			}
385 			debug("Received authentication agent forwarding request.");
386 			success = auth_input_request_forwarding(s->pw);
387 			break;
388 
389 		case SSH_CMSG_PORT_FORWARD_REQUEST:
390 			if (no_port_forwarding_flag) {
391 				debug("Port forwarding not permitted for this authentication.");
392 				break;
393 			}
394 			if (!(options.allow_tcp_forwarding & FORWARD_REMOTE)) {
395 				debug("Port forwarding not permitted.");
396 				break;
397 			}
398 			debug("Received TCP/IP port forwarding request.");
399 			if (channel_input_port_forward_request(s->pw->pw_uid == 0,
400 			    options.gateway_ports) < 0) {
401 				debug("Port forwarding failed.");
402 				break;
403 			}
404 			success = 1;
405 			break;
406 
407 		case SSH_CMSG_MAX_PACKET_SIZE:
408 			if (packet_set_maxsize(packet_get_int()) > 0)
409 				success = 1;
410 			break;
411 
412 		case SSH_CMSG_EXEC_SHELL:
413 		case SSH_CMSG_EXEC_CMD:
414 			if (type == SSH_CMSG_EXEC_CMD) {
415 				command = packet_get_string(&dlen);
416 				debug("Exec command '%.500s'", command);
417 				if (do_exec(s, command) != 0)
418 					packet_disconnect(
419 					    "command execution failed");
420 				free(command);
421 			} else {
422 				if (do_exec(s, NULL) != 0)
423 					packet_disconnect(
424 					    "shell execution failed");
425 			}
426 			packet_check_eom();
427 			session_close(s);
428 			return;
429 
430 		default:
431 			/*
432 			 * Any unknown messages in this phase are ignored,
433 			 * and a failure message is returned.
434 			 */
435 			logit("Unknown packet type received after authentication: %d", type);
436 		}
437 		packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
438 		packet_send();
439 		packet_write_wait();
440 
441 		/* Enable compression now that we have replied if appropriate. */
442 		if (enable_compression_after_reply) {
443 			enable_compression_after_reply = 0;
444 			packet_start_compression(compression_level);
445 		}
446 	}
447 }
448 
449 #define USE_PIPES
450 /*
451  * This is called to fork and execute a command when we have no tty.  This
452  * will call do_child from the child, and server_loop from the parent after
453  * setting up file descriptors and such.
454  */
455 int
456 do_exec_no_pty(Session *s, const char *command)
457 {
458 	pid_t pid;
459 
460 #ifdef USE_PIPES
461 	int pin[2], pout[2], perr[2];
462 
463 	if (s == NULL)
464 		fatal("do_exec_no_pty: no session");
465 
466 	/* Allocate pipes for communicating with the program. */
467 	if (pipe(pin) < 0) {
468 		error("%s: pipe in: %.100s", __func__, strerror(errno));
469 		return -1;
470 	}
471 	if (pipe(pout) < 0) {
472 		error("%s: pipe out: %.100s", __func__, strerror(errno));
473 		close(pin[0]);
474 		close(pin[1]);
475 		return -1;
476 	}
477 	if (pipe(perr) < 0) {
478 		error("%s: pipe err: %.100s", __func__,
479 		    strerror(errno));
480 		close(pin[0]);
481 		close(pin[1]);
482 		close(pout[0]);
483 		close(pout[1]);
484 		return -1;
485 	}
486 #else
487 	int inout[2], err[2];
488 
489 	if (s == NULL)
490 		fatal("do_exec_no_pty: no session");
491 
492 	/* Uses socket pairs to communicate with the program. */
493 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0) {
494 		error("%s: socketpair #1: %.100s", __func__, strerror(errno));
495 		return -1;
496 	}
497 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) {
498 		error("%s: socketpair #2: %.100s", __func__,
499 		    strerror(errno));
500 		close(inout[0]);
501 		close(inout[1]);
502 		return -1;
503 	}
504 #endif
505 
506 	session_proctitle(s);
507 
508 	/* Fork the child. */
509 	switch ((pid = fork())) {
510 	case -1:
511 		error("%s: fork: %.100s", __func__, strerror(errno));
512 #ifdef USE_PIPES
513 		close(pin[0]);
514 		close(pin[1]);
515 		close(pout[0]);
516 		close(pout[1]);
517 		close(perr[0]);
518 		close(perr[1]);
519 #else
520 		close(inout[0]);
521 		close(inout[1]);
522 		close(err[0]);
523 		close(err[1]);
524 #endif
525 		return -1;
526 	case 0:
527 		is_child = 1;
528 
529 		/* Child.  Reinitialize the log since the pid has changed. */
530 		log_init(__progname, options.log_level,
531 		    options.log_facility, log_stderr);
532 
533 		/*
534 		 * Create a new session and process group since the 4.4BSD
535 		 * setlogin() affects the entire process group.
536 		 */
537 		if (setsid() < 0)
538 			error("setsid failed: %.100s", strerror(errno));
539 
540 #ifdef USE_PIPES
541 		/*
542 		 * Redirect stdin.  We close the parent side of the socket
543 		 * pair, and make the child side the standard input.
544 		 */
545 		close(pin[1]);
546 		if (dup2(pin[0], 0) < 0)
547 			perror("dup2 stdin");
548 		close(pin[0]);
549 
550 		/* Redirect stdout. */
551 		close(pout[0]);
552 		if (dup2(pout[1], 1) < 0)
553 			perror("dup2 stdout");
554 		close(pout[1]);
555 
556 		/* Redirect stderr. */
557 		close(perr[0]);
558 		if (dup2(perr[1], 2) < 0)
559 			perror("dup2 stderr");
560 		close(perr[1]);
561 #else
562 		/*
563 		 * Redirect stdin, stdout, and stderr.  Stdin and stdout will
564 		 * use the same socket, as some programs (particularly rdist)
565 		 * seem to depend on it.
566 		 */
567 		close(inout[1]);
568 		close(err[1]);
569 		if (dup2(inout[0], 0) < 0)	/* stdin */
570 			perror("dup2 stdin");
571 		if (dup2(inout[0], 1) < 0)	/* stdout (same as stdin) */
572 			perror("dup2 stdout");
573 		close(inout[0]);
574 		if (dup2(err[0], 2) < 0)	/* stderr */
575 			perror("dup2 stderr");
576 		close(err[0]);
577 #endif
578 
579 
580 #ifdef _UNICOS
581 		cray_init_job(s->pw); /* set up cray jid and tmpdir */
582 #endif
583 
584 		/* Do processing for the child (exec command etc). */
585 		do_child(s, command);
586 		/* NOTREACHED */
587 	default:
588 		break;
589 	}
590 
591 #ifdef _UNICOS
592 	signal(WJSIGNAL, cray_job_termination_handler);
593 #endif /* _UNICOS */
594 #ifdef HAVE_CYGWIN
595 	cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
596 #endif
597 
598 	s->pid = pid;
599 	/* Set interactive/non-interactive mode. */
600 	packet_set_interactive(s->display != NULL,
601 	    options.ip_qos_interactive, options.ip_qos_bulk);
602 
603 	/*
604 	 * Clear loginmsg, since it's the child's responsibility to display
605 	 * it to the user, otherwise multiple sessions may accumulate
606 	 * multiple copies of the login messages.
607 	 */
608 	buffer_clear(&loginmsg);
609 
610 #ifdef USE_PIPES
611 	/* We are the parent.  Close the child sides of the pipes. */
612 	close(pin[0]);
613 	close(pout[1]);
614 	close(perr[1]);
615 
616 	if (compat20) {
617 		session_set_fds(s, pin[1], pout[0], perr[0],
618 		    s->is_subsystem, 0);
619 	} else {
620 		/* Enter the interactive session. */
621 		server_loop(pid, pin[1], pout[0], perr[0]);
622 		/* server_loop has closed pin[1], pout[0], and perr[0]. */
623 	}
624 #else
625 	/* We are the parent.  Close the child sides of the socket pairs. */
626 	close(inout[0]);
627 	close(err[0]);
628 
629 	/*
630 	 * Enter the interactive session.  Note: server_loop must be able to
631 	 * handle the case that fdin and fdout are the same.
632 	 */
633 	if (compat20) {
634 		session_set_fds(s, inout[1], inout[1], err[1],
635 		    s->is_subsystem, 0);
636 	} else {
637 		server_loop(pid, inout[1], inout[1], err[1]);
638 		/* server_loop has closed inout[1] and err[1]. */
639 	}
640 #endif
641 	return 0;
642 }
643 
644 /*
645  * This is called to fork and execute a command when we have a tty.  This
646  * will call do_child from the child, and server_loop from the parent after
647  * setting up file descriptors, controlling tty, updating wtmp, utmp,
648  * lastlog, and other such operations.
649  */
650 int
651 do_exec_pty(Session *s, const char *command)
652 {
653 	int fdout, ptyfd, ttyfd, ptymaster;
654 	pid_t pid;
655 
656 	if (s == NULL)
657 		fatal("do_exec_pty: no session");
658 	ptyfd = s->ptyfd;
659 	ttyfd = s->ttyfd;
660 
661 	/*
662 	 * Create another descriptor of the pty master side for use as the
663 	 * standard input.  We could use the original descriptor, but this
664 	 * simplifies code in server_loop.  The descriptor is bidirectional.
665 	 * Do this before forking (and cleanup in the child) so as to
666 	 * detect and gracefully fail out-of-fd conditions.
667 	 */
668 	if ((fdout = dup(ptyfd)) < 0) {
669 		error("%s: dup #1: %s", __func__, strerror(errno));
670 		close(ttyfd);
671 		close(ptyfd);
672 		return -1;
673 	}
674 	/* we keep a reference to the pty master */
675 	if ((ptymaster = dup(ptyfd)) < 0) {
676 		error("%s: dup #2: %s", __func__, strerror(errno));
677 		close(ttyfd);
678 		close(ptyfd);
679 		close(fdout);
680 		return -1;
681 	}
682 
683 	/* Fork the child. */
684 	switch ((pid = fork())) {
685 	case -1:
686 		error("%s: fork: %.100s", __func__, strerror(errno));
687 		close(fdout);
688 		close(ptymaster);
689 		close(ttyfd);
690 		close(ptyfd);
691 		return -1;
692 	case 0:
693 		is_child = 1;
694 
695 		close(fdout);
696 		close(ptymaster);
697 
698 		/* Child.  Reinitialize the log because the pid has changed. */
699 		log_init(__progname, options.log_level,
700 		    options.log_facility, log_stderr);
701 		/* Close the master side of the pseudo tty. */
702 		close(ptyfd);
703 
704 		/* Make the pseudo tty our controlling tty. */
705 		pty_make_controlling_tty(&ttyfd, s->tty);
706 
707 		/* Redirect stdin/stdout/stderr from the pseudo tty. */
708 		if (dup2(ttyfd, 0) < 0)
709 			error("dup2 stdin: %s", strerror(errno));
710 		if (dup2(ttyfd, 1) < 0)
711 			error("dup2 stdout: %s", strerror(errno));
712 		if (dup2(ttyfd, 2) < 0)
713 			error("dup2 stderr: %s", strerror(errno));
714 
715 		/* Close the extra descriptor for the pseudo tty. */
716 		close(ttyfd);
717 
718 		/* record login, etc. similar to login(1) */
719 #ifndef HAVE_OSF_SIA
720 		if (!(options.use_login && command == NULL)) {
721 #ifdef _UNICOS
722 			cray_init_job(s->pw); /* set up cray jid and tmpdir */
723 #endif /* _UNICOS */
724 			do_login(s, command);
725 		}
726 # ifdef LOGIN_NEEDS_UTMPX
727 		else
728 			do_pre_login(s);
729 # endif
730 #endif
731 		/*
732 		 * Do common processing for the child, such as execing
733 		 * the command.
734 		 */
735 		do_child(s, command);
736 		/* NOTREACHED */
737 	default:
738 		break;
739 	}
740 
741 #ifdef _UNICOS
742 	signal(WJSIGNAL, cray_job_termination_handler);
743 #endif /* _UNICOS */
744 #ifdef HAVE_CYGWIN
745 	cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
746 #endif
747 
748 	s->pid = pid;
749 
750 	/* Parent.  Close the slave side of the pseudo tty. */
751 	close(ttyfd);
752 
753 	/* Enter interactive session. */
754 	s->ptymaster = ptymaster;
755 	packet_set_interactive(1,
756 	    options.ip_qos_interactive, options.ip_qos_bulk);
757 	if (compat20) {
758 		session_set_fds(s, ptyfd, fdout, -1, 1, 1);
759 	} else {
760 		server_loop(pid, ptyfd, fdout, -1);
761 		/* server_loop _has_ closed ptyfd and fdout. */
762 	}
763 	return 0;
764 }
765 
766 #ifdef LOGIN_NEEDS_UTMPX
767 static void
768 do_pre_login(Session *s)
769 {
770 	socklen_t fromlen;
771 	struct sockaddr_storage from;
772 	pid_t pid = getpid();
773 
774 	/*
775 	 * Get IP address of client. If the connection is not a socket, let
776 	 * the address be 0.0.0.0.
777 	 */
778 	memset(&from, 0, sizeof(from));
779 	fromlen = sizeof(from);
780 	if (packet_connection_is_on_socket()) {
781 		if (getpeername(packet_get_connection_in(),
782 		    (struct sockaddr *)&from, &fromlen) < 0) {
783 			debug("getpeername: %.100s", strerror(errno));
784 			cleanup_exit(255);
785 		}
786 	}
787 
788 	record_utmp_only(pid, s->tty, s->pw->pw_name,
789 	    get_remote_name_or_ip(utmp_len, options.use_dns),
790 	    (struct sockaddr *)&from, fromlen);
791 }
792 #endif
793 
794 /*
795  * This is called to fork and execute a command.  If another command is
796  * to be forced, execute that instead.
797  */
798 int
799 do_exec(Session *s, const char *command)
800 {
801 	int ret;
802 
803 	if (options.adm_forced_command) {
804 		original_command = command;
805 		command = options.adm_forced_command;
806 		if (IS_INTERNAL_SFTP(command)) {
807 			s->is_subsystem = s->is_subsystem ?
808 			    SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR;
809 		} else if (s->is_subsystem)
810 			s->is_subsystem = SUBSYSTEM_EXT;
811 		debug("Forced command (config) '%.900s'", command);
812 	} else if (forced_command) {
813 		original_command = command;
814 		command = forced_command;
815 		if (IS_INTERNAL_SFTP(command)) {
816 			s->is_subsystem = s->is_subsystem ?
817 			    SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR;
818 		} else if (s->is_subsystem)
819 			s->is_subsystem = SUBSYSTEM_EXT;
820 		debug("Forced command (key option) '%.900s'", command);
821 	}
822 
823 #ifdef SSH_AUDIT_EVENTS
824 	if (command != NULL)
825 		PRIVSEP(audit_run_command(command));
826 	else if (s->ttyfd == -1) {
827 		char *shell = s->pw->pw_shell;
828 
829 		if (shell[0] == '\0')	/* empty shell means /bin/sh */
830 			shell =_PATH_BSHELL;
831 		PRIVSEP(audit_run_command(shell));
832 	}
833 #endif
834 	if (s->ttyfd != -1)
835 		ret = do_exec_pty(s, command);
836 	else
837 		ret = do_exec_no_pty(s, command);
838 
839 	original_command = NULL;
840 
841 	/*
842 	 * Clear loginmsg: it's the child's responsibility to display
843 	 * it to the user, otherwise multiple sessions may accumulate
844 	 * multiple copies of the login messages.
845 	 */
846 	buffer_clear(&loginmsg);
847 
848 	return ret;
849 }
850 
851 /* administrative, login(1)-like work */
852 void
853 do_login(Session *s, const char *command)
854 {
855 	socklen_t fromlen;
856 	struct sockaddr_storage from;
857 	struct passwd * pw = s->pw;
858 	pid_t pid = getpid();
859 
860 	/*
861 	 * Get IP address of client. If the connection is not a socket, let
862 	 * the address be 0.0.0.0.
863 	 */
864 	memset(&from, 0, sizeof(from));
865 	fromlen = sizeof(from);
866 	if (packet_connection_is_on_socket()) {
867 		if (getpeername(packet_get_connection_in(),
868 		    (struct sockaddr *)&from, &fromlen) < 0) {
869 			debug("getpeername: %.100s", strerror(errno));
870 			cleanup_exit(255);
871 		}
872 	}
873 
874 	/* Record that there was a login on that tty from the remote host. */
875 	if (!use_privsep)
876 		record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
877 		    get_remote_name_or_ip(utmp_len,
878 		    options.use_dns),
879 		    (struct sockaddr *)&from, fromlen);
880 
881 #ifdef USE_PAM
882 	/*
883 	 * If password change is needed, do it now.
884 	 * This needs to occur before the ~/.hushlogin check.
885 	 */
886 	if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
887 		display_loginmsg();
888 		do_pam_chauthtok();
889 		s->authctxt->force_pwchange = 0;
890 		/* XXX - signal [net] parent to enable forwardings */
891 	}
892 #endif
893 
894 	if (check_quietlogin(s, command))
895 		return;
896 
897 	display_loginmsg();
898 
899 	do_motd();
900 }
901 
902 /*
903  * Display the message of the day.
904  */
905 void
906 do_motd(void)
907 {
908 	FILE *f;
909 	char buf[256];
910 
911 	if (options.print_motd) {
912 #ifdef HAVE_LOGIN_CAP
913 		f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
914 		    "/etc/motd"), "r");
915 #else
916 		f = fopen("/etc/motd", "r");
917 #endif
918 		if (f) {
919 			while (fgets(buf, sizeof(buf), f))
920 				fputs(buf, stdout);
921 			fclose(f);
922 		}
923 	}
924 }
925 
926 
927 /*
928  * Check for quiet login, either .hushlogin or command given.
929  */
930 int
931 check_quietlogin(Session *s, const char *command)
932 {
933 	char buf[256];
934 	struct passwd *pw = s->pw;
935 	struct stat st;
936 
937 	/* Return 1 if .hushlogin exists or a command given. */
938 	if (command != NULL)
939 		return 1;
940 	snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
941 #ifdef HAVE_LOGIN_CAP
942 	if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
943 		return 1;
944 #else
945 	if (stat(buf, &st) >= 0)
946 		return 1;
947 #endif
948 	return 0;
949 }
950 
951 /*
952  * Sets the value of the given variable in the environment.  If the variable
953  * already exists, its value is overridden.
954  */
955 void
956 child_set_env(char ***envp, u_int *envsizep, const char *name,
957 	const char *value)
958 {
959 	char **env;
960 	u_int envsize;
961 	u_int i, namelen;
962 
963 	/*
964 	 * If we're passed an uninitialized list, allocate a single null
965 	 * entry before continuing.
966 	 */
967 	if (*envp == NULL && *envsizep == 0) {
968 		*envp = xmalloc(sizeof(char *));
969 		*envp[0] = NULL;
970 		*envsizep = 1;
971 	}
972 
973 	/*
974 	 * Find the slot where the value should be stored.  If the variable
975 	 * already exists, we reuse the slot; otherwise we append a new slot
976 	 * at the end of the array, expanding if necessary.
977 	 */
978 	env = *envp;
979 	namelen = strlen(name);
980 	for (i = 0; env[i]; i++)
981 		if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
982 			break;
983 	if (env[i]) {
984 		/* Reuse the slot. */
985 		free(env[i]);
986 	} else {
987 		/* New variable.  Expand if necessary. */
988 		envsize = *envsizep;
989 		if (i >= envsize - 1) {
990 			if (envsize >= 1000)
991 				fatal("child_set_env: too many env vars");
992 			envsize += 50;
993 			env = (*envp) = xrealloc(env, envsize, sizeof(char *));
994 			*envsizep = envsize;
995 		}
996 		/* Need to set the NULL pointer at end of array beyond the new slot. */
997 		env[i + 1] = NULL;
998 	}
999 
1000 	/* Allocate space and format the variable in the appropriate slot. */
1001 	env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
1002 	snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
1003 }
1004 
1005 /*
1006  * Reads environment variables from the given file and adds/overrides them
1007  * into the environment.  If the file does not exist, this does nothing.
1008  * Otherwise, it must consist of empty lines, comments (line starts with '#')
1009  * and assignments of the form name=value.  No other forms are allowed.
1010  */
1011 static void
1012 read_environment_file(char ***env, u_int *envsize,
1013 	const char *filename)
1014 {
1015 	FILE *f;
1016 	char buf[4096];
1017 	char *cp, *value;
1018 	u_int lineno = 0;
1019 
1020 	f = fopen(filename, "r");
1021 	if (!f)
1022 		return;
1023 
1024 	while (fgets(buf, sizeof(buf), f)) {
1025 		if (++lineno > 1000)
1026 			fatal("Too many lines in environment file %s", filename);
1027 		for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
1028 			;
1029 		if (!*cp || *cp == '#' || *cp == '\n')
1030 			continue;
1031 
1032 		cp[strcspn(cp, "\n")] = '\0';
1033 
1034 		value = strchr(cp, '=');
1035 		if (value == NULL) {
1036 			fprintf(stderr, "Bad line %u in %.100s\n", lineno,
1037 			    filename);
1038 			continue;
1039 		}
1040 		/*
1041 		 * Replace the equals sign by nul, and advance value to
1042 		 * the value string.
1043 		 */
1044 		*value = '\0';
1045 		value++;
1046 		child_set_env(env, envsize, cp, value);
1047 	}
1048 	fclose(f);
1049 }
1050 
1051 #ifdef HAVE_ETC_DEFAULT_LOGIN
1052 /*
1053  * Return named variable from specified environment, or NULL if not present.
1054  */
1055 static char *
1056 child_get_env(char **env, const char *name)
1057 {
1058 	int i;
1059 	size_t len;
1060 
1061 	len = strlen(name);
1062 	for (i=0; env[i] != NULL; i++)
1063 		if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
1064 			return(env[i] + len + 1);
1065 	return NULL;
1066 }
1067 
1068 /*
1069  * Read /etc/default/login.
1070  * We pick up the PATH (or SUPATH for root) and UMASK.
1071  */
1072 static void
1073 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
1074 {
1075 	char **tmpenv = NULL, *var;
1076 	u_int i, tmpenvsize = 0;
1077 	u_long mask;
1078 
1079 	/*
1080 	 * We don't want to copy the whole file to the child's environment,
1081 	 * so we use a temporary environment and copy the variables we're
1082 	 * interested in.
1083 	 */
1084 	read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
1085 
1086 	if (tmpenv == NULL)
1087 		return;
1088 
1089 	if (uid == 0)
1090 		var = child_get_env(tmpenv, "SUPATH");
1091 	else
1092 		var = child_get_env(tmpenv, "PATH");
1093 	if (var != NULL)
1094 		child_set_env(env, envsize, "PATH", var);
1095 
1096 	if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
1097 		if (sscanf(var, "%5lo", &mask) == 1)
1098 			umask((mode_t)mask);
1099 
1100 	for (i = 0; tmpenv[i] != NULL; i++)
1101 		free(tmpenv[i]);
1102 	free(tmpenv);
1103 }
1104 #endif /* HAVE_ETC_DEFAULT_LOGIN */
1105 
1106 void
1107 copy_environment(char **source, char ***env, u_int *envsize)
1108 {
1109 	char *var_name, *var_val;
1110 	int i;
1111 
1112 	if (source == NULL)
1113 		return;
1114 
1115 	for(i = 0; source[i] != NULL; i++) {
1116 		var_name = xstrdup(source[i]);
1117 		if ((var_val = strstr(var_name, "=")) == NULL) {
1118 			free(var_name);
1119 			continue;
1120 		}
1121 		*var_val++ = '\0';
1122 
1123 		debug3("Copy environment: %s=%s", var_name, var_val);
1124 		child_set_env(env, envsize, var_name, var_val);
1125 
1126 		free(var_name);
1127 	}
1128 }
1129 
1130 static char **
1131 do_setup_env(Session *s, const char *shell)
1132 {
1133 	char buf[256];
1134 	u_int i, envsize;
1135 	char **env, *laddr;
1136 	struct passwd *pw = s->pw;
1137 #if !defined (HAVE_LOGIN_CAP) && !defined (HAVE_CYGWIN)
1138 	char *path = NULL;
1139 #else
1140 	extern char **environ;
1141 	char **senv, **var;
1142 #endif
1143 
1144 	/* Initialize the environment. */
1145 	envsize = 100;
1146 	env = xcalloc(envsize, sizeof(char *));
1147 	env[0] = NULL;
1148 
1149 #ifdef HAVE_CYGWIN
1150 	/*
1151 	 * The Windows environment contains some setting which are
1152 	 * important for a running system. They must not be dropped.
1153 	 */
1154 	{
1155 		char **p;
1156 
1157 		p = fetch_windows_environment();
1158 		copy_environment(p, &env, &envsize);
1159 		free_windows_environment(p);
1160 	}
1161 #endif
1162 
1163 	if (getenv("TZ"))
1164 		child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1165 
1166 #ifdef GSSAPI
1167 	/* Allow any GSSAPI methods that we've used to alter
1168 	 * the childs environment as they see fit
1169 	 */
1170 	ssh_gssapi_do_child(&env, &envsize);
1171 #endif
1172 
1173 	if (!options.use_login) {
1174 		/* Set basic environment. */
1175 		for (i = 0; i < s->num_env; i++)
1176 			child_set_env(&env, &envsize, s->env[i].name,
1177 			    s->env[i].val);
1178 
1179 		child_set_env(&env, &envsize, "USER", pw->pw_name);
1180 		child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1181 #ifdef _AIX
1182 		child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1183 #endif
1184 		child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1185 		snprintf(buf, sizeof buf, "%.200s/%.50s",
1186 			 _PATH_MAILDIR, pw->pw_name);
1187 		child_set_env(&env, &envsize, "MAIL", buf);
1188 #ifdef HAVE_LOGIN_CAP
1189 		child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1190 		child_set_env(&env, &envsize, "TERM", "su");
1191 		senv = environ;
1192 		environ = xmalloc(sizeof(char *));
1193 		*environ = NULL;
1194 		(void) setusercontext(lc, pw, pw->pw_uid,
1195 		    LOGIN_SETENV|LOGIN_SETPATH);
1196 		copy_environment(environ, &env, &envsize);
1197 		for (var = environ; *var != NULL; ++var)
1198 			free(*var);
1199 		free(environ);
1200 		environ = senv;
1201 #else /* HAVE_LOGIN_CAP */
1202 # ifndef HAVE_CYGWIN
1203 		/*
1204 		 * There's no standard path on Windows. The path contains
1205 		 * important components pointing to the system directories,
1206 		 * needed for loading shared libraries. So the path better
1207 		 * remains intact here.
1208 		 */
1209 #  ifdef HAVE_ETC_DEFAULT_LOGIN
1210 		read_etc_default_login(&env, &envsize, pw->pw_uid);
1211 		path = child_get_env(env, "PATH");
1212 #  endif /* HAVE_ETC_DEFAULT_LOGIN */
1213 		if (path == NULL || *path == '\0') {
1214 			child_set_env(&env, &envsize, "PATH",
1215 			    s->pw->pw_uid == 0 ?
1216 				SUPERUSER_PATH : _PATH_STDPATH);
1217 		}
1218 # endif /* HAVE_CYGWIN */
1219 #endif /* HAVE_LOGIN_CAP */
1220 
1221 		/* Normal systems set SHELL by default. */
1222 		child_set_env(&env, &envsize, "SHELL", shell);
1223 	}
1224 
1225 	/* Set custom environment options from RSA authentication. */
1226 	if (!options.use_login) {
1227 		while (custom_environment) {
1228 			struct envstring *ce = custom_environment;
1229 			char *str = ce->s;
1230 
1231 			for (i = 0; str[i] != '=' && str[i]; i++)
1232 				;
1233 			if (str[i] == '=') {
1234 				str[i] = 0;
1235 				child_set_env(&env, &envsize, str, str + i + 1);
1236 			}
1237 			custom_environment = ce->next;
1238 			free(ce->s);
1239 			free(ce);
1240 		}
1241 	}
1242 
1243 	/* SSH_CLIENT deprecated */
1244 	snprintf(buf, sizeof buf, "%.50s %d %d",
1245 	    get_remote_ipaddr(), get_remote_port(), get_local_port());
1246 	child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1247 
1248 	laddr = get_local_ipaddr(packet_get_connection_in());
1249 	snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1250 	    get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1251 	free(laddr);
1252 	child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1253 
1254 	if (s->ttyfd != -1)
1255 		child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1256 	if (s->term)
1257 		child_set_env(&env, &envsize, "TERM", s->term);
1258 	if (s->display)
1259 		child_set_env(&env, &envsize, "DISPLAY", s->display);
1260 	if (original_command)
1261 		child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1262 		    original_command);
1263 
1264 #ifdef _UNICOS
1265 	if (cray_tmpdir[0] != '\0')
1266 		child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1267 #endif /* _UNICOS */
1268 
1269 	/*
1270 	 * Since we clear KRB5CCNAME at startup, if it's set now then it
1271 	 * must have been set by a native authentication method (eg AIX or
1272 	 * SIA), so copy it to the child.
1273 	 */
1274 	{
1275 		char *cp;
1276 
1277 		if ((cp = getenv("KRB5CCNAME")) != NULL)
1278 			child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1279 	}
1280 
1281 #ifdef _AIX
1282 	{
1283 		char *cp;
1284 
1285 		if ((cp = getenv("AUTHSTATE")) != NULL)
1286 			child_set_env(&env, &envsize, "AUTHSTATE", cp);
1287 		read_environment_file(&env, &envsize, "/etc/environment");
1288 	}
1289 #endif
1290 #ifdef KRB5
1291 	if (s->authctxt->krb5_ccname)
1292 		child_set_env(&env, &envsize, "KRB5CCNAME",
1293 		    s->authctxt->krb5_ccname);
1294 #endif
1295 #ifdef USE_PAM
1296 	/*
1297 	 * Pull in any environment variables that may have
1298 	 * been set by PAM.
1299 	 */
1300 	if (options.use_pam) {
1301 		char **p;
1302 
1303 		p = fetch_pam_child_environment();
1304 		copy_environment(p, &env, &envsize);
1305 		free_pam_environment(p);
1306 
1307 		p = fetch_pam_environment();
1308 		copy_environment(p, &env, &envsize);
1309 		free_pam_environment(p);
1310 	}
1311 #endif /* USE_PAM */
1312 
1313 	if (auth_sock_name != NULL)
1314 		child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1315 		    auth_sock_name);
1316 
1317 	/* read $HOME/.ssh/environment. */
1318 	if (options.permit_user_env && !options.use_login) {
1319 		snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1320 		    strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1321 		read_environment_file(&env, &envsize, buf);
1322 	}
1323 	if (debug_flag) {
1324 		/* dump the environment */
1325 		fprintf(stderr, "Environment:\n");
1326 		for (i = 0; env[i]; i++)
1327 			fprintf(stderr, "  %.200s\n", env[i]);
1328 	}
1329 	return env;
1330 }
1331 
1332 /*
1333  * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1334  * first in this order).
1335  */
1336 static void
1337 do_rc_files(Session *s, const char *shell)
1338 {
1339 	FILE *f = NULL;
1340 	char cmd[1024];
1341 	int do_xauth;
1342 	struct stat st;
1343 
1344 	do_xauth =
1345 	    s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1346 
1347 	/* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
1348 	if (!s->is_subsystem && options.adm_forced_command == NULL &&
1349 	    !no_user_rc && stat(_PATH_SSH_USER_RC, &st) >= 0) {
1350 		snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1351 		    shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1352 		if (debug_flag)
1353 			fprintf(stderr, "Running %s\n", cmd);
1354 		f = popen(cmd, "w");
1355 		if (f) {
1356 			if (do_xauth)
1357 				fprintf(f, "%s %s\n", s->auth_proto,
1358 				    s->auth_data);
1359 			pclose(f);
1360 		} else
1361 			fprintf(stderr, "Could not run %s\n",
1362 			    _PATH_SSH_USER_RC);
1363 	} else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1364 		if (debug_flag)
1365 			fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1366 			    _PATH_SSH_SYSTEM_RC);
1367 		f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1368 		if (f) {
1369 			if (do_xauth)
1370 				fprintf(f, "%s %s\n", s->auth_proto,
1371 				    s->auth_data);
1372 			pclose(f);
1373 		} else
1374 			fprintf(stderr, "Could not run %s\n",
1375 			    _PATH_SSH_SYSTEM_RC);
1376 	} else if (do_xauth && options.xauth_location != NULL) {
1377 		/* Add authority data to .Xauthority if appropriate. */
1378 		if (debug_flag) {
1379 			fprintf(stderr,
1380 			    "Running %.500s remove %.100s\n",
1381 			    options.xauth_location, s->auth_display);
1382 			fprintf(stderr,
1383 			    "%.500s add %.100s %.100s %.100s\n",
1384 			    options.xauth_location, s->auth_display,
1385 			    s->auth_proto, s->auth_data);
1386 		}
1387 		snprintf(cmd, sizeof cmd, "%s -q -",
1388 		    options.xauth_location);
1389 		f = popen(cmd, "w");
1390 		if (f) {
1391 			fprintf(f, "remove %s\n",
1392 			    s->auth_display);
1393 			fprintf(f, "add %s %s %s\n",
1394 			    s->auth_display, s->auth_proto,
1395 			    s->auth_data);
1396 			pclose(f);
1397 		} else {
1398 			fprintf(stderr, "Could not run %s\n",
1399 			    cmd);
1400 		}
1401 	}
1402 }
1403 
1404 static void
1405 do_nologin(struct passwd *pw)
1406 {
1407 	FILE *f = NULL;
1408 	char buf[1024], *nl, *def_nl = _PATH_NOLOGIN;
1409 	struct stat sb;
1410 
1411 #ifdef HAVE_LOGIN_CAP
1412 	if (login_getcapbool(lc, "ignorenologin", 0) || pw->pw_uid == 0)
1413 		return;
1414 	nl = login_getcapstr(lc, "nologin", def_nl, def_nl);
1415 #else
1416 	if (pw->pw_uid == 0)
1417 		return;
1418 	nl = def_nl;
1419 #endif
1420 	if (stat(nl, &sb) == -1) {
1421 		if (nl != def_nl)
1422 			free(nl);
1423 		return;
1424 	}
1425 
1426 	/* /etc/nologin exists.  Print its contents if we can and exit. */
1427 	logit("User %.100s not allowed because %s exists", pw->pw_name, nl);
1428 	if ((f = fopen(nl, "r")) != NULL) {
1429  		while (fgets(buf, sizeof(buf), f))
1430  			fputs(buf, stderr);
1431  		fclose(f);
1432  	}
1433 	exit(254);
1434 }
1435 
1436 /*
1437  * Chroot into a directory after checking it for safety: all path components
1438  * must be root-owned directories with strict permissions.
1439  */
1440 static void
1441 safely_chroot(const char *path, uid_t uid)
1442 {
1443 	const char *cp;
1444 	char component[MAXPATHLEN];
1445 	struct stat st;
1446 
1447 	if (*path != '/')
1448 		fatal("chroot path does not begin at root");
1449 	if (strlen(path) >= sizeof(component))
1450 		fatal("chroot path too long");
1451 
1452 	/*
1453 	 * Descend the path, checking that each component is a
1454 	 * root-owned directory with strict permissions.
1455 	 */
1456 	for (cp = path; cp != NULL;) {
1457 		if ((cp = strchr(cp, '/')) == NULL)
1458 			strlcpy(component, path, sizeof(component));
1459 		else {
1460 			cp++;
1461 			memcpy(component, path, cp - path);
1462 			component[cp - path] = '\0';
1463 		}
1464 
1465 		debug3("%s: checking '%s'", __func__, component);
1466 
1467 		if (stat(component, &st) != 0)
1468 			fatal("%s: stat(\"%s\"): %s", __func__,
1469 			    component, strerror(errno));
1470 		if (st.st_uid != 0 || (st.st_mode & 022) != 0)
1471 			fatal("bad ownership or modes for chroot "
1472 			    "directory %s\"%s\"",
1473 			    cp == NULL ? "" : "component ", component);
1474 		if (!S_ISDIR(st.st_mode))
1475 			fatal("chroot path %s\"%s\" is not a directory",
1476 			    cp == NULL ? "" : "component ", component);
1477 
1478 	}
1479 
1480 	if (chdir(path) == -1)
1481 		fatal("Unable to chdir to chroot path \"%s\": "
1482 		    "%s", path, strerror(errno));
1483 	if (chroot(path) == -1)
1484 		fatal("chroot(\"%s\"): %s", path, strerror(errno));
1485 	if (chdir("/") == -1)
1486 		fatal("%s: chdir(/) after chroot: %s",
1487 		    __func__, strerror(errno));
1488 	verbose("Changed root directory to \"%s\"", path);
1489 }
1490 
1491 /* Set login name, uid, gid, and groups. */
1492 void
1493 do_setusercontext(struct passwd *pw)
1494 {
1495 	char *chroot_path, *tmp;
1496 
1497 	platform_setusercontext(pw);
1498 
1499 	if (platform_privileged_uidswap()) {
1500 #ifdef HAVE_LOGIN_CAP
1501 		if (setusercontext(lc, pw, pw->pw_uid,
1502 		    (LOGIN_SETALL & ~(LOGIN_SETENV|LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1503 			perror("unable to set user context");
1504 			exit(1);
1505 		}
1506 #else
1507 		if (setlogin(pw->pw_name) < 0)
1508 			error("setlogin failed: %s", strerror(errno));
1509 		if (setgid(pw->pw_gid) < 0) {
1510 			perror("setgid");
1511 			exit(1);
1512 		}
1513 		/* Initialize the group list. */
1514 		if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1515 			perror("initgroups");
1516 			exit(1);
1517 		}
1518 		endgrent();
1519 #endif
1520 
1521 		platform_setusercontext_post_groups(pw);
1522 
1523 		if (options.chroot_directory != NULL &&
1524 		    strcasecmp(options.chroot_directory, "none") != 0) {
1525                         tmp = tilde_expand_filename(options.chroot_directory,
1526 			    pw->pw_uid);
1527 			chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1528 			    "u", pw->pw_name, (char *)NULL);
1529 			safely_chroot(chroot_path, pw->pw_uid);
1530 			free(tmp);
1531 			free(chroot_path);
1532 			/* Make sure we don't attempt to chroot again */
1533 			free(options.chroot_directory);
1534 			options.chroot_directory = NULL;
1535 		}
1536 
1537 #ifdef HAVE_LOGIN_CAP
1538 		if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
1539 			perror("unable to set user context (setuser)");
1540 			exit(1);
1541 		}
1542 		/*
1543 		 * FreeBSD's setusercontext() will not apply the user's
1544 		 * own umask setting unless running with the user's UID.
1545 		 */
1546 		(void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUMASK);
1547 #else
1548 		/* Permanently switch to the desired uid. */
1549 		permanently_set_uid(pw);
1550 #endif
1551 	} else if (options.chroot_directory != NULL &&
1552 	    strcasecmp(options.chroot_directory, "none") != 0) {
1553 		fatal("server lacks privileges to chroot to ChrootDirectory");
1554 	}
1555 
1556 	if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1557 		fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1558 }
1559 
1560 static void
1561 do_pwchange(Session *s)
1562 {
1563 	fflush(NULL);
1564 	fprintf(stderr, "WARNING: Your password has expired.\n");
1565 	if (s->ttyfd != -1) {
1566 		fprintf(stderr,
1567 		    "You must change your password now and login again!\n");
1568 #ifdef WITH_SELINUX
1569 		setexeccon(NULL);
1570 #endif
1571 #ifdef PASSWD_NEEDS_USERNAME
1572 		execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1573 		    (char *)NULL);
1574 #else
1575 		execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1576 #endif
1577 		perror("passwd");
1578 	} else {
1579 		fprintf(stderr,
1580 		    "Password change required but no TTY available.\n");
1581 	}
1582 	exit(1);
1583 }
1584 
1585 static void
1586 launch_login(struct passwd *pw, const char *hostname)
1587 {
1588 	/* Launch login(1). */
1589 
1590 	execl(LOGIN_PROGRAM, "login", "-h", hostname,
1591 #ifdef xxxLOGIN_NEEDS_TERM
1592 		    (s->term ? s->term : "unknown"),
1593 #endif /* LOGIN_NEEDS_TERM */
1594 #ifdef LOGIN_NO_ENDOPT
1595 	    "-p", "-f", pw->pw_name, (char *)NULL);
1596 #else
1597 	    "-p", "-f", "--", pw->pw_name, (char *)NULL);
1598 #endif
1599 
1600 	/* Login couldn't be executed, die. */
1601 
1602 	perror("login");
1603 	exit(1);
1604 }
1605 
1606 static void
1607 child_close_fds(void)
1608 {
1609 	extern AuthenticationConnection *auth_conn;
1610 
1611 	if (auth_conn) {
1612 		ssh_close_authentication_connection(auth_conn);
1613 		auth_conn = NULL;
1614 	}
1615 
1616 	if (packet_get_connection_in() == packet_get_connection_out())
1617 		close(packet_get_connection_in());
1618 	else {
1619 		close(packet_get_connection_in());
1620 		close(packet_get_connection_out());
1621 	}
1622 	/*
1623 	 * Close all descriptors related to channels.  They will still remain
1624 	 * open in the parent.
1625 	 */
1626 	/* XXX better use close-on-exec? -markus */
1627 	channel_close_all();
1628 
1629 	/*
1630 	 * Close any extra file descriptors.  Note that there may still be
1631 	 * descriptors left by system functions.  They will be closed later.
1632 	 */
1633 	endpwent();
1634 
1635 	/*
1636 	 * Close any extra open file descriptors so that we don't have them
1637 	 * hanging around in clients.  Note that we want to do this after
1638 	 * initgroups, because at least on Solaris 2.3 it leaves file
1639 	 * descriptors open.
1640 	 */
1641 	closefrom(STDERR_FILENO + 1);
1642 }
1643 
1644 /*
1645  * Performs common processing for the child, such as setting up the
1646  * environment, closing extra file descriptors, setting the user and group
1647  * ids, and executing the command or shell.
1648  */
1649 #define ARGV_MAX 10
1650 void
1651 do_child(Session *s, const char *command)
1652 {
1653 	extern char **environ;
1654 	char **env;
1655 	char *argv[ARGV_MAX];
1656 	const char *shell, *shell0, *hostname = NULL;
1657 	struct passwd *pw = s->pw;
1658 	int r = 0;
1659 
1660 	/* remove hostkey from the child's memory */
1661 	destroy_sensitive_data();
1662 
1663 	/* Force a password change */
1664 	if (s->authctxt->force_pwchange) {
1665 		do_setusercontext(pw);
1666 		child_close_fds();
1667 		do_pwchange(s);
1668 		exit(1);
1669 	}
1670 
1671 	/* login(1) is only called if we execute the login shell */
1672 	if (options.use_login && command != NULL)
1673 		options.use_login = 0;
1674 
1675 #ifdef _UNICOS
1676 	cray_setup(pw->pw_uid, pw->pw_name, command);
1677 #endif /* _UNICOS */
1678 
1679 	/*
1680 	 * Login(1) does this as well, and it needs uid 0 for the "-h"
1681 	 * switch, so we let login(1) to this for us.
1682 	 */
1683 	if (!options.use_login) {
1684 #ifdef HAVE_OSF_SIA
1685 		session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1686 		if (!check_quietlogin(s, command))
1687 			do_motd();
1688 #else /* HAVE_OSF_SIA */
1689 		/* When PAM is enabled we rely on it to do the nologin check */
1690 		if (!options.use_pam)
1691 			do_nologin(pw);
1692 		do_setusercontext(pw);
1693 		/*
1694 		 * PAM session modules in do_setusercontext may have
1695 		 * generated messages, so if this in an interactive
1696 		 * login then display them too.
1697 		 */
1698 		if (!check_quietlogin(s, command))
1699 			display_loginmsg();
1700 #endif /* HAVE_OSF_SIA */
1701 	}
1702 
1703 #ifdef USE_PAM
1704 	if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1705 		debug3("PAM session not opened, exiting");
1706 		display_loginmsg();
1707 		exit(254);
1708 	}
1709 #endif
1710 
1711 	/*
1712 	 * Get the shell from the password data.  An empty shell field is
1713 	 * legal, and means /bin/sh.
1714 	 */
1715 	shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1716 
1717 	/*
1718 	 * Make sure $SHELL points to the shell from the password file,
1719 	 * even if shell is overridden from login.conf
1720 	 */
1721 	env = do_setup_env(s, shell);
1722 
1723 #ifdef HAVE_LOGIN_CAP
1724 	shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1725 #endif
1726 
1727 	/* we have to stash the hostname before we close our socket. */
1728 	if (options.use_login)
1729 		hostname = get_remote_name_or_ip(utmp_len,
1730 		    options.use_dns);
1731 	/*
1732 	 * Close the connection descriptors; note that this is the child, and
1733 	 * the server will still have the socket open, and it is important
1734 	 * that we do not shutdown it.  Note that the descriptors cannot be
1735 	 * closed before building the environment, as we call
1736 	 * get_remote_ipaddr there.
1737 	 */
1738 	child_close_fds();
1739 
1740 	/*
1741 	 * Must take new environment into use so that .ssh/rc,
1742 	 * /etc/ssh/sshrc and xauth are run in the proper environment.
1743 	 */
1744 	environ = env;
1745 
1746 #if defined(KRB5) && defined(USE_AFS)
1747 	/*
1748 	 * At this point, we check to see if AFS is active and if we have
1749 	 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1750 	 * if we can (and need to) extend the ticket into an AFS token. If
1751 	 * we don't do this, we run into potential problems if the user's
1752 	 * home directory is in AFS and it's not world-readable.
1753 	 */
1754 
1755 	if (options.kerberos_get_afs_token && k_hasafs() &&
1756 	    (s->authctxt->krb5_ctx != NULL)) {
1757 		char cell[64];
1758 
1759 		debug("Getting AFS token");
1760 
1761 		k_setpag();
1762 
1763 		if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1764 			krb5_afslog(s->authctxt->krb5_ctx,
1765 			    s->authctxt->krb5_fwd_ccache, cell, NULL);
1766 
1767 		krb5_afslog_home(s->authctxt->krb5_ctx,
1768 		    s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1769 	}
1770 #endif
1771 
1772 	/* Change current directory to the user's home directory. */
1773 	if (chdir(pw->pw_dir) < 0) {
1774 		/* Suppress missing homedir warning for chroot case */
1775 #ifdef HAVE_LOGIN_CAP
1776 		r = login_getcapbool(lc, "requirehome", 0);
1777 #endif
1778 		if (r || options.chroot_directory == NULL ||
1779 		    strcasecmp(options.chroot_directory, "none") == 0)
1780 			fprintf(stderr, "Could not chdir to home "
1781 			    "directory %s: %s\n", pw->pw_dir,
1782 			    strerror(errno));
1783 		if (r)
1784 			exit(1);
1785 	}
1786 
1787 	closefrom(STDERR_FILENO + 1);
1788 
1789 	if (!options.use_login)
1790 		do_rc_files(s, shell);
1791 
1792 	/* restore SIGPIPE for child */
1793 	signal(SIGPIPE, SIG_DFL);
1794 
1795 	if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) {
1796 		printf("This service allows sftp connections only.\n");
1797 		fflush(NULL);
1798 		exit(1);
1799 	} else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1800 		extern int optind, optreset;
1801 		int i;
1802 		char *p, *args;
1803 
1804 		setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME);
1805 		args = xstrdup(command ? command : "sftp-server");
1806 		for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1807 			if (i < ARGV_MAX - 1)
1808 				argv[i++] = p;
1809 		argv[i] = NULL;
1810 		optind = optreset = 1;
1811 		__progname = argv[0];
1812 #ifdef WITH_SELINUX
1813 		ssh_selinux_change_context("sftpd_t");
1814 #endif
1815 		exit(sftp_server_main(i, argv, s->pw));
1816 	}
1817 
1818 	fflush(NULL);
1819 
1820 	if (options.use_login) {
1821 		launch_login(pw, hostname);
1822 		/* NEVERREACHED */
1823 	}
1824 
1825 	/* Get the last component of the shell name. */
1826 	if ((shell0 = strrchr(shell, '/')) != NULL)
1827 		shell0++;
1828 	else
1829 		shell0 = shell;
1830 
1831 	/*
1832 	 * If we have no command, execute the shell.  In this case, the shell
1833 	 * name to be passed in argv[0] is preceded by '-' to indicate that
1834 	 * this is a login shell.
1835 	 */
1836 	if (!command) {
1837 		char argv0[256];
1838 
1839 		/* Start the shell.  Set initial character to '-'. */
1840 		argv0[0] = '-';
1841 
1842 		if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1843 		    >= sizeof(argv0) - 1) {
1844 			errno = EINVAL;
1845 			perror(shell);
1846 			exit(1);
1847 		}
1848 
1849 		/* Execute the shell. */
1850 		argv[0] = argv0;
1851 		argv[1] = NULL;
1852 		execve(shell, argv, env);
1853 
1854 		/* Executing the shell failed. */
1855 		perror(shell);
1856 		exit(1);
1857 	}
1858 	/*
1859 	 * Execute the command using the user's shell.  This uses the -c
1860 	 * option to execute the command.
1861 	 */
1862 	argv[0] = (char *) shell0;
1863 	argv[1] = "-c";
1864 	argv[2] = (char *) command;
1865 	argv[3] = NULL;
1866 	execve(shell, argv, env);
1867 	perror(shell);
1868 	exit(1);
1869 }
1870 
1871 void
1872 session_unused(int id)
1873 {
1874 	debug3("%s: session id %d unused", __func__, id);
1875 	if (id >= options.max_sessions ||
1876 	    id >= sessions_nalloc) {
1877 		fatal("%s: insane session id %d (max %d nalloc %d)",
1878 		    __func__, id, options.max_sessions, sessions_nalloc);
1879 	}
1880 	bzero(&sessions[id], sizeof(*sessions));
1881 	sessions[id].self = id;
1882 	sessions[id].used = 0;
1883 	sessions[id].chanid = -1;
1884 	sessions[id].ptyfd = -1;
1885 	sessions[id].ttyfd = -1;
1886 	sessions[id].ptymaster = -1;
1887 	sessions[id].x11_chanids = NULL;
1888 	sessions[id].next_unused = sessions_first_unused;
1889 	sessions_first_unused = id;
1890 }
1891 
1892 Session *
1893 session_new(void)
1894 {
1895 	Session *s, *tmp;
1896 
1897 	if (sessions_first_unused == -1) {
1898 		if (sessions_nalloc >= options.max_sessions)
1899 			return NULL;
1900 		debug2("%s: allocate (allocated %d max %d)",
1901 		    __func__, sessions_nalloc, options.max_sessions);
1902 		tmp = xrealloc(sessions, sessions_nalloc + 1,
1903 		    sizeof(*sessions));
1904 		if (tmp == NULL) {
1905 			error("%s: cannot allocate %d sessions",
1906 			    __func__, sessions_nalloc + 1);
1907 			return NULL;
1908 		}
1909 		sessions = tmp;
1910 		session_unused(sessions_nalloc++);
1911 	}
1912 
1913 	if (sessions_first_unused >= sessions_nalloc ||
1914 	    sessions_first_unused < 0) {
1915 		fatal("%s: insane first_unused %d max %d nalloc %d",
1916 		    __func__, sessions_first_unused, options.max_sessions,
1917 		    sessions_nalloc);
1918 	}
1919 
1920 	s = &sessions[sessions_first_unused];
1921 	if (s->used) {
1922 		fatal("%s: session %d already used",
1923 		    __func__, sessions_first_unused);
1924 	}
1925 	sessions_first_unused = s->next_unused;
1926 	s->used = 1;
1927 	s->next_unused = -1;
1928 	debug("session_new: session %d", s->self);
1929 
1930 	return s;
1931 }
1932 
1933 static void
1934 session_dump(void)
1935 {
1936 	int i;
1937 	for (i = 0; i < sessions_nalloc; i++) {
1938 		Session *s = &sessions[i];
1939 
1940 		debug("dump: used %d next_unused %d session %d %p "
1941 		    "channel %d pid %ld",
1942 		    s->used,
1943 		    s->next_unused,
1944 		    s->self,
1945 		    s,
1946 		    s->chanid,
1947 		    (long)s->pid);
1948 	}
1949 }
1950 
1951 int
1952 session_open(Authctxt *authctxt, int chanid)
1953 {
1954 	Session *s = session_new();
1955 	debug("session_open: channel %d", chanid);
1956 	if (s == NULL) {
1957 		error("no more sessions");
1958 		return 0;
1959 	}
1960 	s->authctxt = authctxt;
1961 	s->pw = authctxt->pw;
1962 	if (s->pw == NULL || !authctxt->valid)
1963 		fatal("no user for session %d", s->self);
1964 	debug("session_open: session %d: link with channel %d", s->self, chanid);
1965 	s->chanid = chanid;
1966 	return 1;
1967 }
1968 
1969 Session *
1970 session_by_tty(char *tty)
1971 {
1972 	int i;
1973 	for (i = 0; i < sessions_nalloc; i++) {
1974 		Session *s = &sessions[i];
1975 		if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1976 			debug("session_by_tty: session %d tty %s", i, tty);
1977 			return s;
1978 		}
1979 	}
1980 	debug("session_by_tty: unknown tty %.100s", tty);
1981 	session_dump();
1982 	return NULL;
1983 }
1984 
1985 static Session *
1986 session_by_channel(int id)
1987 {
1988 	int i;
1989 	for (i = 0; i < sessions_nalloc; i++) {
1990 		Session *s = &sessions[i];
1991 		if (s->used && s->chanid == id) {
1992 			debug("session_by_channel: session %d channel %d",
1993 			    i, id);
1994 			return s;
1995 		}
1996 	}
1997 	debug("session_by_channel: unknown channel %d", id);
1998 	session_dump();
1999 	return NULL;
2000 }
2001 
2002 static Session *
2003 session_by_x11_channel(int id)
2004 {
2005 	int i, j;
2006 
2007 	for (i = 0; i < sessions_nalloc; i++) {
2008 		Session *s = &sessions[i];
2009 
2010 		if (s->x11_chanids == NULL || !s->used)
2011 			continue;
2012 		for (j = 0; s->x11_chanids[j] != -1; j++) {
2013 			if (s->x11_chanids[j] == id) {
2014 				debug("session_by_x11_channel: session %d "
2015 				    "channel %d", s->self, id);
2016 				return s;
2017 			}
2018 		}
2019 	}
2020 	debug("session_by_x11_channel: unknown channel %d", id);
2021 	session_dump();
2022 	return NULL;
2023 }
2024 
2025 static Session *
2026 session_by_pid(pid_t pid)
2027 {
2028 	int i;
2029 	debug("session_by_pid: pid %ld", (long)pid);
2030 	for (i = 0; i < sessions_nalloc; i++) {
2031 		Session *s = &sessions[i];
2032 		if (s->used && s->pid == pid)
2033 			return s;
2034 	}
2035 	error("session_by_pid: unknown pid %ld", (long)pid);
2036 	session_dump();
2037 	return NULL;
2038 }
2039 
2040 static int
2041 session_window_change_req(Session *s)
2042 {
2043 	s->col = packet_get_int();
2044 	s->row = packet_get_int();
2045 	s->xpixel = packet_get_int();
2046 	s->ypixel = packet_get_int();
2047 	packet_check_eom();
2048 	pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
2049 	return 1;
2050 }
2051 
2052 static int
2053 session_pty_req(Session *s)
2054 {
2055 	u_int len;
2056 	int n_bytes;
2057 
2058 	if (no_pty_flag) {
2059 		debug("Allocating a pty not permitted for this authentication.");
2060 		return 0;
2061 	}
2062 	if (s->ttyfd != -1) {
2063 		packet_disconnect("Protocol error: you already have a pty.");
2064 		return 0;
2065 	}
2066 
2067 	s->term = packet_get_string(&len);
2068 
2069 	if (compat20) {
2070 		s->col = packet_get_int();
2071 		s->row = packet_get_int();
2072 	} else {
2073 		s->row = packet_get_int();
2074 		s->col = packet_get_int();
2075 	}
2076 	s->xpixel = packet_get_int();
2077 	s->ypixel = packet_get_int();
2078 
2079 	if (strcmp(s->term, "") == 0) {
2080 		free(s->term);
2081 		s->term = NULL;
2082 	}
2083 
2084 	/* Allocate a pty and open it. */
2085 	debug("Allocating pty.");
2086 	if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
2087 	    sizeof(s->tty)))) {
2088 		free(s->term);
2089 		s->term = NULL;
2090 		s->ptyfd = -1;
2091 		s->ttyfd = -1;
2092 		error("session_pty_req: session %d alloc failed", s->self);
2093 		return 0;
2094 	}
2095 	debug("session_pty_req: session %d alloc %s", s->self, s->tty);
2096 
2097 	/* for SSH1 the tty modes length is not given */
2098 	if (!compat20)
2099 		n_bytes = packet_remaining();
2100 	tty_parse_modes(s->ttyfd, &n_bytes);
2101 
2102 	if (!use_privsep)
2103 		pty_setowner(s->pw, s->tty);
2104 
2105 	/* Set window size from the packet. */
2106 	pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
2107 
2108 	packet_check_eom();
2109 	session_proctitle(s);
2110 	return 1;
2111 }
2112 
2113 static int
2114 session_subsystem_req(Session *s)
2115 {
2116 	struct stat st;
2117 	u_int len;
2118 	int success = 0;
2119 	char *prog, *cmd, *subsys = packet_get_string(&len);
2120 	u_int i;
2121 
2122 	packet_check_eom();
2123 	logit("subsystem request for %.100s by user %s", subsys,
2124 	    s->pw->pw_name);
2125 
2126 	for (i = 0; i < options.num_subsystems; i++) {
2127 		if (strcmp(subsys, options.subsystem_name[i]) == 0) {
2128 			prog = options.subsystem_command[i];
2129 			cmd = options.subsystem_args[i];
2130 			if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) {
2131 				s->is_subsystem = SUBSYSTEM_INT_SFTP;
2132 				debug("subsystem: %s", prog);
2133 			} else {
2134 				if (stat(prog, &st) < 0)
2135 					debug("subsystem: cannot stat %s: %s",
2136 					    prog, strerror(errno));
2137 				s->is_subsystem = SUBSYSTEM_EXT;
2138 				debug("subsystem: exec() %s", cmd);
2139 			}
2140 			success = do_exec(s, cmd) == 0;
2141 			break;
2142 		}
2143 	}
2144 
2145 	if (!success)
2146 		logit("subsystem request for %.100s failed, subsystem not found",
2147 		    subsys);
2148 
2149 	free(subsys);
2150 	return success;
2151 }
2152 
2153 static int
2154 session_x11_req(Session *s)
2155 {
2156 	int success;
2157 
2158 	if (s->auth_proto != NULL || s->auth_data != NULL) {
2159 		error("session_x11_req: session %d: "
2160 		    "x11 forwarding already active", s->self);
2161 		return 0;
2162 	}
2163 	s->single_connection = packet_get_char();
2164 	s->auth_proto = packet_get_string(NULL);
2165 	s->auth_data = packet_get_string(NULL);
2166 	s->screen = packet_get_int();
2167 	packet_check_eom();
2168 
2169 	success = session_setup_x11fwd(s);
2170 	if (!success) {
2171 		free(s->auth_proto);
2172 		free(s->auth_data);
2173 		s->auth_proto = NULL;
2174 		s->auth_data = NULL;
2175 	}
2176 	return success;
2177 }
2178 
2179 static int
2180 session_shell_req(Session *s)
2181 {
2182 	packet_check_eom();
2183 	return do_exec(s, NULL) == 0;
2184 }
2185 
2186 static int
2187 session_exec_req(Session *s)
2188 {
2189 	u_int len, success;
2190 
2191 	char *command = packet_get_string(&len);
2192 	packet_check_eom();
2193 	success = do_exec(s, command) == 0;
2194 	free(command);
2195 	return success;
2196 }
2197 
2198 static int
2199 session_break_req(Session *s)
2200 {
2201 
2202 	packet_get_int();	/* ignored */
2203 	packet_check_eom();
2204 
2205 	if (s->ptymaster == -1 || tcsendbreak(s->ptymaster, 0) < 0)
2206 		return 0;
2207 	return 1;
2208 }
2209 
2210 static int
2211 session_env_req(Session *s)
2212 {
2213 	char *name, *val;
2214 	u_int name_len, val_len, i;
2215 
2216 	name = packet_get_string(&name_len);
2217 	val = packet_get_string(&val_len);
2218 	packet_check_eom();
2219 
2220 	/* Don't set too many environment variables */
2221 	if (s->num_env > 128) {
2222 		debug2("Ignoring env request %s: too many env vars", name);
2223 		goto fail;
2224 	}
2225 
2226 	for (i = 0; i < options.num_accept_env; i++) {
2227 		if (match_pattern(name, options.accept_env[i])) {
2228 			debug2("Setting env %d: %s=%s", s->num_env, name, val);
2229 			s->env = xrealloc(s->env, s->num_env + 1,
2230 			    sizeof(*s->env));
2231 			s->env[s->num_env].name = name;
2232 			s->env[s->num_env].val = val;
2233 			s->num_env++;
2234 			return (1);
2235 		}
2236 	}
2237 	debug2("Ignoring env request %s: disallowed name", name);
2238 
2239  fail:
2240 	free(name);
2241 	free(val);
2242 	return (0);
2243 }
2244 
2245 static int
2246 session_auth_agent_req(Session *s)
2247 {
2248 	static int called = 0;
2249 	packet_check_eom();
2250 	if (no_agent_forwarding_flag || !options.allow_agent_forwarding) {
2251 		debug("session_auth_agent_req: no_agent_forwarding_flag");
2252 		return 0;
2253 	}
2254 	if (called) {
2255 		return 0;
2256 	} else {
2257 		called = 1;
2258 		return auth_input_request_forwarding(s->pw);
2259 	}
2260 }
2261 
2262 int
2263 session_input_channel_req(Channel *c, const char *rtype)
2264 {
2265 	int success = 0;
2266 	Session *s;
2267 
2268 	if ((s = session_by_channel(c->self)) == NULL) {
2269 		logit("session_input_channel_req: no session %d req %.100s",
2270 		    c->self, rtype);
2271 		return 0;
2272 	}
2273 	debug("session_input_channel_req: session %d req %s", s->self, rtype);
2274 
2275 	/*
2276 	 * a session is in LARVAL state until a shell, a command
2277 	 * or a subsystem is executed
2278 	 */
2279 	if (c->type == SSH_CHANNEL_LARVAL) {
2280 		if (strcmp(rtype, "shell") == 0) {
2281 			success = session_shell_req(s);
2282 		} else if (strcmp(rtype, "exec") == 0) {
2283 			success = session_exec_req(s);
2284 		} else if (strcmp(rtype, "pty-req") == 0) {
2285 			success = session_pty_req(s);
2286 		} else if (strcmp(rtype, "x11-req") == 0) {
2287 			success = session_x11_req(s);
2288 		} else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2289 			success = session_auth_agent_req(s);
2290 		} else if (strcmp(rtype, "subsystem") == 0) {
2291 			success = session_subsystem_req(s);
2292 		} else if (strcmp(rtype, "env") == 0) {
2293 			success = session_env_req(s);
2294 		}
2295 	}
2296 	if (strcmp(rtype, "window-change") == 0) {
2297 		success = session_window_change_req(s);
2298 	} else if (strcmp(rtype, "break") == 0) {
2299 		success = session_break_req(s);
2300 	}
2301 
2302 	return success;
2303 }
2304 
2305 void
2306 session_set_fds(Session *s, int fdin, int fdout, int fderr, int ignore_fderr,
2307     int is_tty)
2308 {
2309 	if (!compat20)
2310 		fatal("session_set_fds: called for proto != 2.0");
2311 	/*
2312 	 * now that have a child and a pipe to the child,
2313 	 * we can activate our channel and register the fd's
2314 	 */
2315 	if (s->chanid == -1)
2316 		fatal("no channel for session %d", s->self);
2317 	if (options.hpn_disabled)
2318 		channel_set_fds(s->chanid, fdout, fdin, fderr,
2319 		    ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2320 		    1, is_tty, CHAN_SES_WINDOW_DEFAULT);
2321 	else
2322 		channel_set_fds(s->chanid, fdout, fdin, fderr,
2323 		    ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2324 		    1, is_tty, options.hpn_buffer_size);
2325 }
2326 
2327 /*
2328  * Function to perform pty cleanup. Also called if we get aborted abnormally
2329  * (e.g., due to a dropped connection).
2330  */
2331 void
2332 session_pty_cleanup2(Session *s)
2333 {
2334 	if (s == NULL) {
2335 		error("session_pty_cleanup: no session");
2336 		return;
2337 	}
2338 	if (s->ttyfd == -1)
2339 		return;
2340 
2341 	debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2342 
2343 	/* Record that the user has logged out. */
2344 	if (s->pid != 0)
2345 		record_logout(s->pid, s->tty, s->pw->pw_name);
2346 
2347 	/* Release the pseudo-tty. */
2348 	if (getuid() == 0)
2349 		pty_release(s->tty);
2350 
2351 	/*
2352 	 * Close the server side of the socket pairs.  We must do this after
2353 	 * the pty cleanup, so that another process doesn't get this pty
2354 	 * while we're still cleaning up.
2355 	 */
2356 	if (s->ptymaster != -1 && close(s->ptymaster) < 0)
2357 		error("close(s->ptymaster/%d): %s",
2358 		    s->ptymaster, strerror(errno));
2359 
2360 	/* unlink pty from session */
2361 	s->ttyfd = -1;
2362 }
2363 
2364 void
2365 session_pty_cleanup(Session *s)
2366 {
2367 	PRIVSEP(session_pty_cleanup2(s));
2368 }
2369 
2370 static char *
2371 sig2name(int sig)
2372 {
2373 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2374 	SSH_SIG(ABRT);
2375 	SSH_SIG(ALRM);
2376 	SSH_SIG(FPE);
2377 	SSH_SIG(HUP);
2378 	SSH_SIG(ILL);
2379 	SSH_SIG(INT);
2380 	SSH_SIG(KILL);
2381 	SSH_SIG(PIPE);
2382 	SSH_SIG(QUIT);
2383 	SSH_SIG(SEGV);
2384 	SSH_SIG(TERM);
2385 	SSH_SIG(USR1);
2386 	SSH_SIG(USR2);
2387 #undef	SSH_SIG
2388 	return "SIG@openssh.com";
2389 }
2390 
2391 static void
2392 session_close_x11(int id)
2393 {
2394 	Channel *c;
2395 
2396 	if ((c = channel_by_id(id)) == NULL) {
2397 		debug("session_close_x11: x11 channel %d missing", id);
2398 	} else {
2399 		/* Detach X11 listener */
2400 		debug("session_close_x11: detach x11 channel %d", id);
2401 		channel_cancel_cleanup(id);
2402 		if (c->ostate != CHAN_OUTPUT_CLOSED)
2403 			chan_mark_dead(c);
2404 	}
2405 }
2406 
2407 static void
2408 session_close_single_x11(int id, void *arg)
2409 {
2410 	Session *s;
2411 	u_int i;
2412 
2413 	debug3("session_close_single_x11: channel %d", id);
2414 	channel_cancel_cleanup(id);
2415 	if ((s = session_by_x11_channel(id)) == NULL)
2416 		fatal("session_close_single_x11: no x11 channel %d", id);
2417 	for (i = 0; s->x11_chanids[i] != -1; i++) {
2418 		debug("session_close_single_x11: session %d: "
2419 		    "closing channel %d", s->self, s->x11_chanids[i]);
2420 		/*
2421 		 * The channel "id" is already closing, but make sure we
2422 		 * close all of its siblings.
2423 		 */
2424 		if (s->x11_chanids[i] != id)
2425 			session_close_x11(s->x11_chanids[i]);
2426 	}
2427 	free(s->x11_chanids);
2428 	s->x11_chanids = NULL;
2429 	free(s->display);
2430 	s->display = NULL;
2431 	free(s->auth_proto);
2432 	s->auth_proto = NULL;
2433 	free(s->auth_data);
2434 	s->auth_data = NULL;
2435 	free(s->auth_display);
2436 	s->auth_display = NULL;
2437 }
2438 
2439 static void
2440 session_exit_message(Session *s, int status)
2441 {
2442 	Channel *c;
2443 
2444 	if ((c = channel_lookup(s->chanid)) == NULL)
2445 		fatal("session_exit_message: session %d: no channel %d",
2446 		    s->self, s->chanid);
2447 	debug("session_exit_message: session %d channel %d pid %ld",
2448 	    s->self, s->chanid, (long)s->pid);
2449 
2450 	if (WIFEXITED(status)) {
2451 		channel_request_start(s->chanid, "exit-status", 0);
2452 		packet_put_int(WEXITSTATUS(status));
2453 		packet_send();
2454 	} else if (WIFSIGNALED(status)) {
2455 		channel_request_start(s->chanid, "exit-signal", 0);
2456 		packet_put_cstring(sig2name(WTERMSIG(status)));
2457 #ifdef WCOREDUMP
2458 		packet_put_char(WCOREDUMP(status)? 1 : 0);
2459 #else /* WCOREDUMP */
2460 		packet_put_char(0);
2461 #endif /* WCOREDUMP */
2462 		packet_put_cstring("");
2463 		packet_put_cstring("");
2464 		packet_send();
2465 	} else {
2466 		/* Some weird exit cause.  Just exit. */
2467 		packet_disconnect("wait returned status %04x.", status);
2468 	}
2469 
2470 	/* disconnect channel */
2471 	debug("session_exit_message: release channel %d", s->chanid);
2472 
2473 	/*
2474 	 * Adjust cleanup callback attachment to send close messages when
2475 	 * the channel gets EOF. The session will be then be closed
2476 	 * by session_close_by_channel when the childs close their fds.
2477 	 */
2478 	channel_register_cleanup(c->self, session_close_by_channel, 1);
2479 
2480 	/*
2481 	 * emulate a write failure with 'chan_write_failed', nobody will be
2482 	 * interested in data we write.
2483 	 * Note that we must not call 'chan_read_failed', since there could
2484 	 * be some more data waiting in the pipe.
2485 	 */
2486 	if (c->ostate != CHAN_OUTPUT_CLOSED)
2487 		chan_write_failed(c);
2488 }
2489 
2490 void
2491 session_close(Session *s)
2492 {
2493 	u_int i;
2494 
2495 	debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2496 	if (s->ttyfd != -1)
2497 		session_pty_cleanup(s);
2498 	free(s->term);
2499 	free(s->display);
2500 	free(s->x11_chanids);
2501 	free(s->auth_display);
2502 	free(s->auth_data);
2503 	free(s->auth_proto);
2504 	if (s->env != NULL) {
2505 		for (i = 0; i < s->num_env; i++) {
2506 			free(s->env[i].name);
2507 			free(s->env[i].val);
2508 		}
2509 		free(s->env);
2510 	}
2511 	session_proctitle(s);
2512 	session_unused(s->self);
2513 }
2514 
2515 void
2516 session_close_by_pid(pid_t pid, int status)
2517 {
2518 	Session *s = session_by_pid(pid);
2519 	if (s == NULL) {
2520 		debug("session_close_by_pid: no session for pid %ld",
2521 		    (long)pid);
2522 		return;
2523 	}
2524 	if (s->chanid != -1)
2525 		session_exit_message(s, status);
2526 	if (s->ttyfd != -1)
2527 		session_pty_cleanup(s);
2528 	s->pid = 0;
2529 }
2530 
2531 /*
2532  * this is called when a channel dies before
2533  * the session 'child' itself dies
2534  */
2535 void
2536 session_close_by_channel(int id, void *arg)
2537 {
2538 	Session *s = session_by_channel(id);
2539 	u_int i;
2540 
2541 	if (s == NULL) {
2542 		debug("session_close_by_channel: no session for id %d", id);
2543 		return;
2544 	}
2545 	debug("session_close_by_channel: channel %d child %ld",
2546 	    id, (long)s->pid);
2547 	if (s->pid != 0) {
2548 		debug("session_close_by_channel: channel %d: has child", id);
2549 		/*
2550 		 * delay detach of session, but release pty, since
2551 		 * the fd's to the child are already closed
2552 		 */
2553 		if (s->ttyfd != -1)
2554 			session_pty_cleanup(s);
2555 		return;
2556 	}
2557 	/* detach by removing callback */
2558 	channel_cancel_cleanup(s->chanid);
2559 
2560 	/* Close any X11 listeners associated with this session */
2561 	if (s->x11_chanids != NULL) {
2562 		for (i = 0; s->x11_chanids[i] != -1; i++) {
2563 			session_close_x11(s->x11_chanids[i]);
2564 			s->x11_chanids[i] = -1;
2565 		}
2566 	}
2567 
2568 	s->chanid = -1;
2569 	session_close(s);
2570 }
2571 
2572 void
2573 session_destroy_all(void (*closefunc)(Session *))
2574 {
2575 	int i;
2576 	for (i = 0; i < sessions_nalloc; i++) {
2577 		Session *s = &sessions[i];
2578 		if (s->used) {
2579 			if (closefunc != NULL)
2580 				closefunc(s);
2581 			else
2582 				session_close(s);
2583 		}
2584 	}
2585 }
2586 
2587 static char *
2588 session_tty_list(void)
2589 {
2590 	static char buf[1024];
2591 	int i;
2592 	char *cp;
2593 
2594 	buf[0] = '\0';
2595 	for (i = 0; i < sessions_nalloc; i++) {
2596 		Session *s = &sessions[i];
2597 		if (s->used && s->ttyfd != -1) {
2598 
2599 			if (strncmp(s->tty, "/dev/", 5) != 0) {
2600 				cp = strrchr(s->tty, '/');
2601 				cp = (cp == NULL) ? s->tty : cp + 1;
2602 			} else
2603 				cp = s->tty + 5;
2604 
2605 			if (buf[0] != '\0')
2606 				strlcat(buf, ",", sizeof buf);
2607 			strlcat(buf, cp, sizeof buf);
2608 		}
2609 	}
2610 	if (buf[0] == '\0')
2611 		strlcpy(buf, "notty", sizeof buf);
2612 	return buf;
2613 }
2614 
2615 void
2616 session_proctitle(Session *s)
2617 {
2618 	if (s->pw == NULL)
2619 		error("no user for session %d", s->self);
2620 	else
2621 		setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2622 }
2623 
2624 int
2625 session_setup_x11fwd(Session *s)
2626 {
2627 	struct stat st;
2628 	char display[512], auth_display[512];
2629 	char hostname[MAXHOSTNAMELEN];
2630 	u_int i;
2631 
2632 	if (no_x11_forwarding_flag) {
2633 		packet_send_debug("X11 forwarding disabled in user configuration file.");
2634 		return 0;
2635 	}
2636 	if (!options.x11_forwarding) {
2637 		debug("X11 forwarding disabled in server configuration file.");
2638 		return 0;
2639 	}
2640 	if (!options.xauth_location ||
2641 	    (stat(options.xauth_location, &st) == -1)) {
2642 		packet_send_debug("No xauth program; cannot forward with spoofing.");
2643 		return 0;
2644 	}
2645 	if (options.use_login) {
2646 		packet_send_debug("X11 forwarding disabled; "
2647 		    "not compatible with UseLogin=yes.");
2648 		return 0;
2649 	}
2650 	if (s->display != NULL) {
2651 		debug("X11 display already set.");
2652 		return 0;
2653 	}
2654 	if (x11_create_display_inet(options.x11_display_offset,
2655 	    options.x11_use_localhost, s->single_connection,
2656 	    &s->display_number, &s->x11_chanids) == -1) {
2657 		debug("x11_create_display_inet failed.");
2658 		return 0;
2659 	}
2660 	for (i = 0; s->x11_chanids[i] != -1; i++) {
2661 		channel_register_cleanup(s->x11_chanids[i],
2662 		    session_close_single_x11, 0);
2663 	}
2664 
2665 	/* Set up a suitable value for the DISPLAY variable. */
2666 	if (gethostname(hostname, sizeof(hostname)) < 0)
2667 		fatal("gethostname: %.100s", strerror(errno));
2668 	/*
2669 	 * auth_display must be used as the displayname when the
2670 	 * authorization entry is added with xauth(1).  This will be
2671 	 * different than the DISPLAY string for localhost displays.
2672 	 */
2673 	if (options.x11_use_localhost) {
2674 		snprintf(display, sizeof display, "localhost:%u.%u",
2675 		    s->display_number, s->screen);
2676 		snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2677 		    s->display_number, s->screen);
2678 		s->display = xstrdup(display);
2679 		s->auth_display = xstrdup(auth_display);
2680 	} else {
2681 #ifdef IPADDR_IN_DISPLAY
2682 		struct hostent *he;
2683 		struct in_addr my_addr;
2684 
2685 		he = gethostbyname(hostname);
2686 		if (he == NULL) {
2687 			error("Can't get IP address for X11 DISPLAY.");
2688 			packet_send_debug("Can't get IP address for X11 DISPLAY.");
2689 			return 0;
2690 		}
2691 		memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2692 		snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2693 		    s->display_number, s->screen);
2694 #else
2695 		snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2696 		    s->display_number, s->screen);
2697 #endif
2698 		s->display = xstrdup(display);
2699 		s->auth_display = xstrdup(display);
2700 	}
2701 
2702 	return 1;
2703 }
2704 
2705 static void
2706 do_authenticated2(Authctxt *authctxt)
2707 {
2708 	server_loop2(authctxt);
2709 }
2710 
2711 void
2712 do_cleanup(Authctxt *authctxt)
2713 {
2714 	static int called = 0;
2715 
2716 	debug("do_cleanup");
2717 
2718 	/* no cleanup if we're in the child for login shell */
2719 	if (is_child)
2720 		return;
2721 
2722 	/* avoid double cleanup */
2723 	if (called)
2724 		return;
2725 	called = 1;
2726 
2727 	if (authctxt == NULL)
2728 		return;
2729 
2730 #ifdef USE_PAM
2731 	if (options.use_pam) {
2732 		sshpam_cleanup();
2733 		sshpam_thread_cleanup();
2734 	}
2735 #endif
2736 
2737 	if (!authctxt->authenticated)
2738 		return;
2739 
2740 #ifdef KRB5
2741 	if (options.kerberos_ticket_cleanup &&
2742 	    authctxt->krb5_ctx)
2743 		krb5_cleanup_proc(authctxt);
2744 #endif
2745 
2746 #ifdef GSSAPI
2747 	if (compat20 && options.gss_cleanup_creds)
2748 		ssh_gssapi_cleanup_creds();
2749 #endif
2750 
2751 	/* remove agent socket */
2752 	auth_sock_cleanup_proc(authctxt->pw);
2753 
2754 	/*
2755 	 * Cleanup ptys/utmp only if privsep is disabled,
2756 	 * or if running in monitor.
2757 	 */
2758 	if (!use_privsep || mm_is_monitor())
2759 		session_destroy_all(session_pty_cleanup2);
2760 }
2761