1 /* $OpenBSD: session.c,v 1.241 2008/06/16 13:22:53 dtucker Exp $ */
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * As far as I am concerned, the code I have written for this software
7 * can be used freely for any purpose. Any derived versions of this
8 * software must be clearly marked as such, and if the derived work is
9 * incompatible with the protocol description in the RFC file, it must be
10 * called by a name other than "ssh" or "Secure Shell".
12 * SSH2 support by Markus Friedl.
13 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 #include <sys/types.h>
39 #include <sys/param.h>
40 #ifdef HAVE_SYS_STAT_H
41 # include <sys/stat.h>
43 #include <sys/socket.h>
47 #include <arpa/inet.h>
62 #include "openbsd-compat/sys-queue.h"
81 #include "auth-options.h"
82 #include "pathnames.h"
86 #include "serverloop.h"
91 #include "monitor_wrap.h"
94 #if defined(KRB5) && defined(USE_AFS)
100 Session
*session_new(void);
101 void session_set_fds(Session
*, int, int, int, int);
102 void session_pty_cleanup(Session
*);
103 void session_proctitle(Session
*);
104 int session_setup_x11fwd(Session
*);
105 int do_exec_pty(Session
*, const char *);
106 int do_exec_no_pty(Session
*, const char *);
107 int do_exec(Session
*, const char *);
108 void do_login(Session
*, const char *);
109 #ifdef LOGIN_NEEDS_UTMPX
110 static void do_pre_login(Session
*s
);
112 void do_child(Session
*, const char *);
114 int check_quietlogin(Session
*, const char *);
116 static void do_authenticated1(Authctxt
*);
117 static void do_authenticated2(Authctxt
*);
119 static int session_pty_req(Session
*);
122 extern ServerOptions options
;
123 extern char *__progname
;
124 extern int log_stderr
;
125 extern int debug_flag
;
126 extern u_int utmp_len
;
127 extern int startup_pipe
;
128 extern void destroy_sensitive_data(void);
129 extern Buffer loginmsg
;
131 /* original command from peer. */
132 const char *original_command
= NULL
;
135 static int sessions_first_unused
= -1;
136 static int sessions_nalloc
= 0;
137 static Session
*sessions
= NULL
;
139 #define SUBSYSTEM_NONE 0
140 #define SUBSYSTEM_EXT 1
141 #define SUBSYSTEM_INT_SFTP 2
143 #ifdef HAVE_LOGIN_CAP
147 static int is_child
= 0;
149 /* Name and directory of socket for authentication agent forwarding. */
150 static char *auth_sock_name
= NULL
;
151 static char *auth_sock_dir
= NULL
;
153 /* removes the agent forwarding socket */
156 auth_sock_cleanup_proc(struct passwd
*pw
)
158 if (auth_sock_name
!= NULL
) {
159 temporarily_use_uid(pw
);
160 unlink(auth_sock_name
);
161 rmdir(auth_sock_dir
);
162 auth_sock_name
= NULL
;
168 auth_input_request_forwarding(struct passwd
* pw
)
172 struct sockaddr_un sunaddr
;
174 if (auth_sock_name
!= NULL
) {
175 error("authentication forwarding requested twice.");
179 /* Temporarily drop privileged uid for mkdir/bind. */
180 temporarily_use_uid(pw
);
182 /* Allocate a buffer for the socket name, and format the name. */
183 auth_sock_dir
= xstrdup("/tmp/ssh-XXXXXXXXXX");
185 /* Create private directory for socket */
186 if (mkdtemp(auth_sock_dir
) == NULL
) {
187 packet_send_debug("Agent forwarding disabled: "
188 "mkdtemp() failed: %.100s", strerror(errno
));
190 xfree(auth_sock_dir
);
191 auth_sock_dir
= NULL
;
195 xasprintf(&auth_sock_name
, "%s/agent.%ld",
196 auth_sock_dir
, (long) getpid());
198 /* Create the socket. */
199 sock
= socket(AF_UNIX
, SOCK_STREAM
, 0);
201 error("socket: %.100s", strerror(errno
));
206 /* Bind it to the name. */
207 memset(&sunaddr
, 0, sizeof(sunaddr
));
208 sunaddr
.sun_family
= AF_UNIX
;
209 strlcpy(sunaddr
.sun_path
, auth_sock_name
, sizeof(sunaddr
.sun_path
));
211 if (bind(sock
, (struct sockaddr
*)&sunaddr
, sizeof(sunaddr
)) < 0) {
212 error("bind: %.100s", strerror(errno
));
217 /* Restore the privileged uid. */
220 /* Start listening on the socket. */
221 if (listen(sock
, SSH_LISTEN_BACKLOG
) < 0) {
222 error("listen: %.100s", strerror(errno
));
226 /* Allocate a channel for the authentication agent socket. */
227 nc
= channel_new("auth socket",
228 SSH_CHANNEL_AUTH_SOCKET
, sock
, sock
, -1,
229 CHAN_X11_WINDOW_DEFAULT
, CHAN_X11_PACKET_DEFAULT
,
230 0, "auth socket", 1);
231 strlcpy(nc
->path
, auth_sock_name
, sizeof(nc
->path
));
235 if (auth_sock_name
!= NULL
)
236 xfree(auth_sock_name
);
237 if (auth_sock_dir
!= NULL
) {
238 rmdir(auth_sock_dir
);
239 xfree(auth_sock_dir
);
243 auth_sock_name
= NULL
;
244 auth_sock_dir
= NULL
;
249 display_loginmsg(void)
251 if (buffer_len(&loginmsg
) > 0) {
252 buffer_append(&loginmsg
, "\0", 1);
253 printf("%s", (char *)buffer_ptr(&loginmsg
));
254 buffer_clear(&loginmsg
);
259 do_authenticated(Authctxt
*authctxt
)
261 setproctitle("%s", authctxt
->pw
->pw_name
);
263 /* setup the channel layer */
264 if (!no_port_forwarding_flag
&& options
.allow_tcp_forwarding
)
265 channel_permit_all_opens();
268 do_authenticated2(authctxt
);
270 do_authenticated1(authctxt
);
272 do_cleanup(authctxt
);
276 * Prepares for an interactive session. This is called after the user has
277 * been successfully authenticated. During this message exchange, pseudo
278 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
279 * are requested, etc.
282 do_authenticated1(Authctxt
*authctxt
)
286 int success
, type
, screen_flag
;
287 int enable_compression_after_reply
= 0;
288 u_int proto_len
, data_len
, dlen
, compression_level
= 0;
292 error("no more sessions");
295 s
->authctxt
= authctxt
;
296 s
->pw
= authctxt
->pw
;
299 * We stay in this loop until the client requests to execute a shell
305 /* Get a packet from the client. */
306 type
= packet_read();
308 /* Process the packet. */
310 case SSH_CMSG_REQUEST_COMPRESSION
:
311 compression_level
= packet_get_int();
313 if (compression_level
< 1 || compression_level
> 9) {
314 packet_send_debug("Received invalid compression level %d.",
318 if (options
.compression
== COMP_NONE
) {
319 debug2("compression disabled");
322 /* Enable compression after we have responded with SUCCESS. */
323 enable_compression_after_reply
= 1;
327 case SSH_CMSG_REQUEST_PTY
:
328 success
= session_pty_req(s
);
331 case SSH_CMSG_X11_REQUEST_FORWARDING
:
332 s
->auth_proto
= packet_get_string(&proto_len
);
333 s
->auth_data
= packet_get_string(&data_len
);
335 screen_flag
= packet_get_protocol_flags() &
336 SSH_PROTOFLAG_SCREEN_NUMBER
;
337 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag
);
339 if (packet_remaining() == 4) {
341 debug2("Buggy client: "
342 "X11 screen flag missing");
343 s
->screen
= packet_get_int();
348 success
= session_setup_x11fwd(s
);
350 xfree(s
->auth_proto
);
352 s
->auth_proto
= NULL
;
357 case SSH_CMSG_AGENT_REQUEST_FORWARDING
:
358 if (!options
.allow_agent_forwarding
||
359 no_agent_forwarding_flag
|| compat13
) {
360 debug("Authentication agent forwarding not permitted for this authentication.");
363 debug("Received authentication agent forwarding request.");
364 success
= auth_input_request_forwarding(s
->pw
);
367 case SSH_CMSG_PORT_FORWARD_REQUEST
:
368 if (no_port_forwarding_flag
) {
369 debug("Port forwarding not permitted for this authentication.");
372 if (!options
.allow_tcp_forwarding
) {
373 debug("Port forwarding not permitted.");
376 debug("Received TCP/IP port forwarding request.");
377 if (channel_input_port_forward_request(s
->pw
->pw_uid
== 0,
378 options
.gateway_ports
) < 0) {
379 debug("Port forwarding failed.");
385 case SSH_CMSG_MAX_PACKET_SIZE
:
386 if (packet_set_maxsize(packet_get_int()) > 0)
390 case SSH_CMSG_EXEC_SHELL
:
391 case SSH_CMSG_EXEC_CMD
:
392 if (type
== SSH_CMSG_EXEC_CMD
) {
393 command
= packet_get_string(&dlen
);
394 debug("Exec command '%.500s'", command
);
395 if (do_exec(s
, command
) != 0)
397 "command execution failed");
400 if (do_exec(s
, NULL
) != 0)
402 "shell execution failed");
410 * Any unknown messages in this phase are ignored,
411 * and a failure message is returned.
413 logit("Unknown packet type received after authentication: %d", type
);
415 packet_start(success
? SSH_SMSG_SUCCESS
: SSH_SMSG_FAILURE
);
419 /* Enable compression now that we have replied if appropriate. */
420 if (enable_compression_after_reply
) {
421 enable_compression_after_reply
= 0;
422 packet_start_compression(compression_level
);
429 * This is called to fork and execute a command when we have no tty. This
430 * will call do_child from the child, and server_loop from the parent after
431 * setting up file descriptors and such.
434 do_exec_no_pty(Session
*s
, const char *command
)
439 int pin
[2], pout
[2], perr
[2];
441 /* Allocate pipes for communicating with the program. */
443 error("%s: pipe in: %.100s", __func__
, strerror(errno
));
446 if (pipe(pout
) < 0) {
447 error("%s: pipe out: %.100s", __func__
, strerror(errno
));
452 if (pipe(perr
) < 0) {
453 error("%s: pipe err: %.100s", __func__
, strerror(errno
));
461 int inout
[2], err
[2];
463 /* Uses socket pairs to communicate with the program. */
464 if (socketpair(AF_UNIX
, SOCK_STREAM
, 0, inout
) < 0) {
465 error("%s: socketpair #1: %.100s", __func__
, strerror(errno
));
468 if (socketpair(AF_UNIX
, SOCK_STREAM
, 0, err
) < 0) {
469 error("%s: socketpair #2: %.100s", __func__
, strerror(errno
));
477 fatal("do_exec_no_pty: no session");
479 session_proctitle(s
);
481 /* Fork the child. */
482 switch ((pid
= fork())) {
484 error("%s: fork: %.100s", __func__
, strerror(errno
));
502 /* Child. Reinitialize the log since the pid has changed. */
503 log_init(__progname
, options
.log_level
,
504 options
.log_facility
, log_stderr
);
507 * Create a new session and process group since the 4.4BSD
508 * setlogin() affects the entire process group.
511 error("setsid failed: %.100s", strerror(errno
));
515 * Redirect stdin. We close the parent side of the socket
516 * pair, and make the child side the standard input.
519 if (dup2(pin
[0], 0) < 0)
520 perror("dup2 stdin");
523 /* Redirect stdout. */
525 if (dup2(pout
[1], 1) < 0)
526 perror("dup2 stdout");
529 /* Redirect stderr. */
531 if (dup2(perr
[1], 2) < 0)
532 perror("dup2 stderr");
536 * Redirect stdin, stdout, and stderr. Stdin and stdout will
537 * use the same socket, as some programs (particularly rdist)
538 * seem to depend on it.
542 if (dup2(inout
[0], 0) < 0) /* stdin */
543 perror("dup2 stdin");
544 if (dup2(inout
[0], 1) < 0) /* stdout (same as stdin) */
545 perror("dup2 stdout");
547 if (dup2(err
[0], 2) < 0) /* stderr */
548 perror("dup2 stderr");
554 cray_init_job(s
->pw
); /* set up cray jid and tmpdir */
557 /* Do processing for the child (exec command etc). */
558 do_child(s
, command
);
565 signal(WJSIGNAL
, cray_job_termination_handler
);
569 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE
);
573 /* Set interactive/non-interactive mode. */
574 packet_set_interactive(s
->display
!= NULL
);
577 * Clear loginmsg, since it's the child's responsibility to display
578 * it to the user, otherwise multiple sessions may accumulate
579 * multiple copies of the login messages.
581 buffer_clear(&loginmsg
);
584 /* We are the parent. Close the child sides of the pipes. */
590 if (s
->is_subsystem
) {
594 session_set_fds(s
, pin
[1], pout
[0], perr
[0], 0);
596 /* Enter the interactive session. */
597 server_loop(pid
, pin
[1], pout
[0], perr
[0]);
598 /* server_loop has closed pin[1], pout[0], and perr[0]. */
601 /* We are the parent. Close the child sides of the socket pairs. */
606 * Enter the interactive session. Note: server_loop must be able to
607 * handle the case that fdin and fdout are the same.
610 session_set_fds(s
, inout
[1], inout
[1],
611 s
->is_subsystem
? -1 : err
[1], 0);
615 server_loop(pid
, inout
[1], inout
[1], err
[1]);
616 /* server_loop has closed inout[1] and err[1]. */
623 * This is called to fork and execute a command when we have a tty. This
624 * will call do_child from the child, and server_loop from the parent after
625 * setting up file descriptors, controlling tty, updating wtmp, utmp,
626 * lastlog, and other such operations.
629 do_exec_pty(Session
*s
, const char *command
)
631 int fdout
, ptyfd
, ttyfd
, ptymaster
;
635 fatal("do_exec_pty: no session");
640 * Create another descriptor of the pty master side for use as the
641 * standard input. We could use the original descriptor, but this
642 * simplifies code in server_loop. The descriptor is bidirectional.
643 * Do this before forking (and cleanup in the child) so as to
644 * detect and gracefully fail out-of-fd conditions.
646 if ((fdout
= dup(ptyfd
)) < 0) {
647 error("%s: dup #1: %s", __func__
, strerror(errno
));
652 /* we keep a reference to the pty master */
653 if ((ptymaster
= dup(ptyfd
)) < 0) {
654 error("%s: dup #2: %s", __func__
, strerror(errno
));
661 /* Fork the child. */
662 switch ((pid
= fork())) {
664 error("%s: fork: %.100s", __func__
, strerror(errno
));
676 /* Child. Reinitialize the log because the pid has changed. */
677 log_init(__progname
, options
.log_level
,
678 options
.log_facility
, log_stderr
);
679 /* Close the master side of the pseudo tty. */
682 /* Make the pseudo tty our controlling tty. */
683 pty_make_controlling_tty(&ttyfd
, s
->tty
);
685 /* Redirect stdin/stdout/stderr from the pseudo tty. */
686 if (dup2(ttyfd
, 0) < 0)
687 error("dup2 stdin: %s", strerror(errno
));
688 if (dup2(ttyfd
, 1) < 0)
689 error("dup2 stdout: %s", strerror(errno
));
690 if (dup2(ttyfd
, 2) < 0)
691 error("dup2 stderr: %s", strerror(errno
));
693 /* Close the extra descriptor for the pseudo tty. */
696 /* record login, etc. similar to login(1) */
698 if (!(options
.use_login
&& command
== NULL
)) {
700 cray_init_job(s
->pw
); /* set up cray jid and tmpdir */
702 do_login(s
, command
);
704 # ifdef LOGIN_NEEDS_UTMPX
710 * Do common processing for the child, such as execing
713 do_child(s
, command
);
720 signal(WJSIGNAL
, cray_job_termination_handler
);
724 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE
);
729 /* Parent. Close the slave side of the pseudo tty. */
732 /* Enter interactive session. */
733 s
->ptymaster
= ptymaster
;
734 packet_set_interactive(1);
736 session_set_fds(s
, ptyfd
, fdout
, -1, 1);
738 server_loop(pid
, ptyfd
, fdout
, -1);
739 /* server_loop _has_ closed ptyfd and fdout. */
744 #ifdef LOGIN_NEEDS_UTMPX
746 do_pre_login(Session
*s
)
749 struct sockaddr_storage from
;
750 pid_t pid
= getpid();
753 * Get IP address of client. If the connection is not a socket, let
754 * the address be 0.0.0.0.
756 memset(&from
, 0, sizeof(from
));
757 fromlen
= sizeof(from
);
758 if (packet_connection_is_on_socket()) {
759 if (getpeername(packet_get_connection_in(),
760 (struct sockaddr
*)&from
, &fromlen
) < 0) {
761 debug("getpeername: %.100s", strerror(errno
));
766 record_utmp_only(pid
, s
->tty
, s
->pw
->pw_name
,
767 get_remote_name_or_ip(utmp_len
, options
.use_dns
),
768 (struct sockaddr
*)&from
, fromlen
);
773 * This is called to fork and execute a command. If another command is
774 * to be forced, execute that instead.
777 do_exec(Session
*s
, const char *command
)
781 if (options
.adm_forced_command
) {
782 original_command
= command
;
783 command
= options
.adm_forced_command
;
784 if (strcmp(INTERNAL_SFTP_NAME
, command
) == 0)
785 s
->is_subsystem
= SUBSYSTEM_INT_SFTP
;
786 else if (s
->is_subsystem
)
787 s
->is_subsystem
= SUBSYSTEM_EXT
;
788 debug("Forced command (config) '%.900s'", command
);
789 } else if (forced_command
) {
790 original_command
= command
;
791 command
= forced_command
;
792 if (strcmp(INTERNAL_SFTP_NAME
, command
) == 0)
793 s
->is_subsystem
= SUBSYSTEM_INT_SFTP
;
794 else if (s
->is_subsystem
)
795 s
->is_subsystem
= SUBSYSTEM_EXT
;
796 debug("Forced command (key option) '%.900s'", command
);
799 #ifdef SSH_AUDIT_EVENTS
801 PRIVSEP(audit_run_command(command
));
802 else if (s
->ttyfd
== -1) {
803 char *shell
= s
->pw
->pw_shell
;
805 if (shell
[0] == '\0') /* empty shell means /bin/sh */
807 PRIVSEP(audit_run_command(shell
));
811 ret
= do_exec_pty(s
, command
);
813 ret
= do_exec_no_pty(s
, command
);
815 original_command
= NULL
;
818 * Clear loginmsg: it's the child's responsibility to display
819 * it to the user, otherwise multiple sessions may accumulate
820 * multiple copies of the login messages.
822 buffer_clear(&loginmsg
);
827 /* administrative, login(1)-like work */
829 do_login(Session
*s
, const char *command
)
832 struct sockaddr_storage from
;
833 struct passwd
* pw
= s
->pw
;
834 pid_t pid
= getpid();
837 * Get IP address of client. If the connection is not a socket, let
838 * the address be 0.0.0.0.
840 memset(&from
, 0, sizeof(from
));
841 fromlen
= sizeof(from
);
842 if (packet_connection_is_on_socket()) {
843 if (getpeername(packet_get_connection_in(),
844 (struct sockaddr
*) & from
, &fromlen
) < 0) {
845 debug("getpeername: %.100s", strerror(errno
));
850 /* Record that there was a login on that tty from the remote host. */
852 record_login(pid
, s
->tty
, pw
->pw_name
, pw
->pw_uid
,
853 get_remote_name_or_ip(utmp_len
,
855 (struct sockaddr
*)&from
, fromlen
);
859 * If password change is needed, do it now.
860 * This needs to occur before the ~/.hushlogin check.
862 if (options
.use_pam
&& !use_privsep
&& s
->authctxt
->force_pwchange
) {
865 s
->authctxt
->force_pwchange
= 0;
866 /* XXX - signal [net] parent to enable forwardings */
870 if (check_quietlogin(s
, command
))
879 * Display the message of the day.
886 #ifdef HAVE_LOGIN_CAP
890 #ifdef HAVE_LOGIN_CAP
891 fname
= login_getcapstr(lc
, "copyright", NULL
, NULL
);
892 if (fname
!= NULL
&& (f
= fopen(fname
, "r")) != NULL
) {
893 while (fgets(buf
, sizeof(buf
), f
) != NULL
)
897 #endif /* HAVE_LOGIN_CAP */
898 (void)printf("%s\n\t%s %s\n",
899 "Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994",
900 "The Regents of the University of California. ",
901 "All rights reserved.");
905 if (options
.print_motd
) {
906 #ifdef HAVE_LOGIN_CAP
907 f
= fopen(login_getcapstr(lc
, "welcome", "/etc/motd",
910 f
= fopen("/etc/motd", "r");
913 while (fgets(buf
, sizeof(buf
), f
))
922 * Check for quiet login, either .hushlogin or command given.
925 check_quietlogin(Session
*s
, const char *command
)
928 struct passwd
*pw
= s
->pw
;
931 /* Return 1 if .hushlogin exists or a command given. */
934 snprintf(buf
, sizeof(buf
), "%.200s/.hushlogin", pw
->pw_dir
);
935 #ifdef HAVE_LOGIN_CAP
936 if (login_getcapbool(lc
, "hushlogin", 0) || stat(buf
, &st
) >= 0)
939 if (stat(buf
, &st
) >= 0)
946 * Sets the value of the given variable in the environment. If the variable
947 * already exists, its value is overriden.
950 child_set_env(char ***envp
, u_int
*envsizep
, const char *name
,
958 * If we're passed an uninitialized list, allocate a single null
959 * entry before continuing.
961 if (*envp
== NULL
&& *envsizep
== 0) {
962 *envp
= xmalloc(sizeof(char *));
968 * Find the slot where the value should be stored. If the variable
969 * already exists, we reuse the slot; otherwise we append a new slot
970 * at the end of the array, expanding if necessary.
973 namelen
= strlen(name
);
974 for (i
= 0; env
[i
]; i
++)
975 if (strncmp(env
[i
], name
, namelen
) == 0 && env
[i
][namelen
] == '=')
978 /* Reuse the slot. */
981 /* New variable. Expand if necessary. */
983 if (i
>= envsize
- 1) {
985 fatal("child_set_env: too many env vars");
987 env
= (*envp
) = xrealloc(env
, envsize
, sizeof(char *));
990 /* Need to set the NULL pointer at end of array beyond the new slot. */
994 /* Allocate space and format the variable in the appropriate slot. */
995 env
[i
] = xmalloc(strlen(name
) + 1 + strlen(value
) + 1);
996 snprintf(env
[i
], strlen(name
) + 1 + strlen(value
) + 1, "%s=%s", name
, value
);
1000 * Reads environment variables from the given file and adds/overrides them
1001 * into the environment. If the file does not exist, this does nothing.
1002 * Otherwise, it must consist of empty lines, comments (line starts with '#')
1003 * and assignments of the form name=value. No other forms are allowed.
1006 read_environment_file(char ***env
, u_int
*envsize
,
1007 const char *filename
)
1014 f
= fopen(filename
, "r");
1018 while (fgets(buf
, sizeof(buf
), f
)) {
1019 if (++lineno
> 1000)
1020 fatal("Too many lines in environment file %s", filename
);
1021 for (cp
= buf
; *cp
== ' ' || *cp
== '\t'; cp
++)
1023 if (!*cp
|| *cp
== '#' || *cp
== '\n')
1026 cp
[strcspn(cp
, "\n")] = '\0';
1028 value
= strchr(cp
, '=');
1029 if (value
== NULL
) {
1030 fprintf(stderr
, "Bad line %u in %.100s\n", lineno
,
1035 * Replace the equals sign by nul, and advance value to
1040 child_set_env(env
, envsize
, cp
, value
);
1045 #ifdef HAVE_ETC_DEFAULT_LOGIN
1047 * Return named variable from specified environment, or NULL if not present.
1050 child_get_env(char **env
, const char *name
)
1056 for (i
=0; env
[i
] != NULL
; i
++)
1057 if (strncmp(name
, env
[i
], len
) == 0 && env
[i
][len
] == '=')
1058 return(env
[i
] + len
+ 1);
1063 * Read /etc/default/login.
1064 * We pick up the PATH (or SUPATH for root) and UMASK.
1067 read_etc_default_login(char ***env
, u_int
*envsize
, uid_t uid
)
1069 char **tmpenv
= NULL
, *var
;
1070 u_int i
, tmpenvsize
= 0;
1074 * We don't want to copy the whole file to the child's environment,
1075 * so we use a temporary environment and copy the variables we're
1078 read_environment_file(&tmpenv
, &tmpenvsize
, "/etc/default/login");
1084 var
= child_get_env(tmpenv
, "SUPATH");
1086 var
= child_get_env(tmpenv
, "PATH");
1088 child_set_env(env
, envsize
, "PATH", var
);
1090 if ((var
= child_get_env(tmpenv
, "UMASK")) != NULL
)
1091 if (sscanf(var
, "%5lo", &mask
) == 1)
1092 umask((mode_t
)mask
);
1094 for (i
= 0; tmpenv
[i
] != NULL
; i
++)
1098 #endif /* HAVE_ETC_DEFAULT_LOGIN */
1101 copy_environment(char **source
, char ***env
, u_int
*envsize
)
1103 char *var_name
, *var_val
;
1109 for(i
= 0; source
[i
] != NULL
; i
++) {
1110 var_name
= xstrdup(source
[i
]);
1111 if ((var_val
= strstr(var_name
, "=")) == NULL
) {
1117 debug3("Copy environment: %s=%s", var_name
, var_val
);
1118 child_set_env(env
, envsize
, var_name
, var_val
);
1125 do_setup_env(Session
*s
, const char *shell
)
1130 struct passwd
*pw
= s
->pw
;
1131 #ifndef HAVE_LOGIN_CAP
1134 extern char **environ
;
1138 /* Initialize the environment. */
1140 env
= xcalloc(envsize
, sizeof(char *));
1145 * The Windows environment contains some setting which are
1146 * important for a running system. They must not be dropped.
1151 p
= fetch_windows_environment();
1152 copy_environment(p
, &env
, &envsize
);
1153 free_windows_environment(p
);
1158 child_set_env(&env
, &envsize
, "TZ", getenv("TZ"));
1161 /* Allow any GSSAPI methods that we've used to alter
1162 * the childs environment as they see fit
1164 ssh_gssapi_do_child(&env
, &envsize
);
1167 if (!options
.use_login
) {
1168 /* Set basic environment. */
1169 for (i
= 0; i
< s
->num_env
; i
++)
1170 child_set_env(&env
, &envsize
, s
->env
[i
].name
,
1173 child_set_env(&env
, &envsize
, "USER", pw
->pw_name
);
1174 child_set_env(&env
, &envsize
, "LOGNAME", pw
->pw_name
);
1176 child_set_env(&env
, &envsize
, "LOGIN", pw
->pw_name
);
1178 child_set_env(&env
, &envsize
, "HOME", pw
->pw_dir
);
1179 snprintf(buf
, sizeof buf
, "%.200s/%.50s",
1180 _PATH_MAILDIR
, pw
->pw_name
);
1181 child_set_env(&env
, &envsize
, "MAIL", buf
);
1182 #ifdef HAVE_LOGIN_CAP
1183 child_set_env(&env
, &envsize
, "PATH", _PATH_STDPATH
);
1184 child_set_env(&env
, &envsize
, "TERM", "su");
1186 environ
= xmalloc(sizeof(char *));
1188 (void) setusercontext(lc
, pw
, pw
->pw_uid
,
1189 LOGIN_SETENV
|LOGIN_SETPATH
);
1190 copy_environment(environ
, &env
, &envsize
);
1191 for (var
= environ
; *var
!= NULL
; ++var
)
1195 #else /* HAVE_LOGIN_CAP */
1196 # ifndef HAVE_CYGWIN
1198 * There's no standard path on Windows. The path contains
1199 * important components pointing to the system directories,
1200 * needed for loading shared libraries. So the path better
1201 * remains intact here.
1203 # ifdef HAVE_ETC_DEFAULT_LOGIN
1204 read_etc_default_login(&env
, &envsize
, pw
->pw_uid
);
1205 path
= child_get_env(env
, "PATH");
1206 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1207 if (path
== NULL
|| *path
== '\0') {
1208 child_set_env(&env
, &envsize
, "PATH",
1209 s
->pw
->pw_uid
== 0 ?
1210 SUPERUSER_PATH
: _PATH_STDPATH
);
1212 # endif /* HAVE_CYGWIN */
1213 #endif /* HAVE_LOGIN_CAP */
1215 /* Normal systems set SHELL by default. */
1216 child_set_env(&env
, &envsize
, "SHELL", shell
);
1219 /* Set custom environment options from RSA authentication. */
1220 if (!options
.use_login
) {
1221 while (custom_environment
) {
1222 struct envstring
*ce
= custom_environment
;
1225 for (i
= 0; str
[i
] != '=' && str
[i
]; i
++)
1227 if (str
[i
] == '=') {
1229 child_set_env(&env
, &envsize
, str
, str
+ i
+ 1);
1231 custom_environment
= ce
->next
;
1237 /* SSH_CLIENT deprecated */
1238 snprintf(buf
, sizeof buf
, "%.50s %d %d",
1239 get_remote_ipaddr(), get_remote_port(), get_local_port());
1240 child_set_env(&env
, &envsize
, "SSH_CLIENT", buf
);
1242 laddr
= get_local_ipaddr(packet_get_connection_in());
1243 snprintf(buf
, sizeof buf
, "%.50s %d %.50s %d",
1244 get_remote_ipaddr(), get_remote_port(), laddr
, get_local_port());
1246 child_set_env(&env
, &envsize
, "SSH_CONNECTION", buf
);
1249 child_set_env(&env
, &envsize
, "SSH_TTY", s
->tty
);
1251 child_set_env(&env
, &envsize
, "TERM", s
->term
);
1253 child_set_env(&env
, &envsize
, "DISPLAY", s
->display
);
1254 if (original_command
)
1255 child_set_env(&env
, &envsize
, "SSH_ORIGINAL_COMMAND",
1259 if (cray_tmpdir
[0] != '\0')
1260 child_set_env(&env
, &envsize
, "TMPDIR", cray_tmpdir
);
1261 #endif /* _UNICOS */
1264 * Since we clear KRB5CCNAME at startup, if it's set now then it
1265 * must have been set by a native authentication method (eg AIX or
1266 * SIA), so copy it to the child.
1271 if ((cp
= getenv("KRB5CCNAME")) != NULL
)
1272 child_set_env(&env
, &envsize
, "KRB5CCNAME", cp
);
1279 if ((cp
= getenv("AUTHSTATE")) != NULL
)
1280 child_set_env(&env
, &envsize
, "AUTHSTATE", cp
);
1281 read_environment_file(&env
, &envsize
, "/etc/environment");
1285 if (s
->authctxt
->krb5_ccname
)
1286 child_set_env(&env
, &envsize
, "KRB5CCNAME",
1287 s
->authctxt
->krb5_ccname
);
1291 * Pull in any environment variables that may have
1294 if (options
.use_pam
) {
1297 p
= fetch_pam_child_environment();
1298 copy_environment(p
, &env
, &envsize
);
1299 free_pam_environment(p
);
1301 p
= fetch_pam_environment();
1302 copy_environment(p
, &env
, &envsize
);
1303 free_pam_environment(p
);
1305 #endif /* USE_PAM */
1307 if (auth_sock_name
!= NULL
)
1308 child_set_env(&env
, &envsize
, SSH_AUTHSOCKET_ENV_NAME
,
1311 /* read $HOME/.ssh/environment. */
1312 if (options
.permit_user_env
&& !options
.use_login
) {
1313 snprintf(buf
, sizeof buf
, "%.200s/.ssh/environment",
1314 strcmp(pw
->pw_dir
, "/") ? pw
->pw_dir
: "");
1315 read_environment_file(&env
, &envsize
, buf
);
1318 /* dump the environment */
1319 fprintf(stderr
, "Environment:\n");
1320 for (i
= 0; env
[i
]; i
++)
1321 fprintf(stderr
, " %.200s\n", env
[i
]);
1327 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1328 * first in this order).
1331 do_rc_files(Session
*s
, const char *shell
)
1339 s
->display
!= NULL
&& s
->auth_proto
!= NULL
&& s
->auth_data
!= NULL
;
1341 /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
1342 if (!s
->is_subsystem
&& options
.adm_forced_command
== NULL
&&
1343 !no_user_rc
&& stat(_PATH_SSH_USER_RC
, &st
) >= 0) {
1344 snprintf(cmd
, sizeof cmd
, "%s -c '%s %s'",
1345 shell
, _PATH_BSHELL
, _PATH_SSH_USER_RC
);
1347 fprintf(stderr
, "Running %s\n", cmd
);
1348 f
= popen(cmd
, "w");
1351 fprintf(f
, "%s %s\n", s
->auth_proto
,
1355 fprintf(stderr
, "Could not run %s\n",
1357 } else if (stat(_PATH_SSH_SYSTEM_RC
, &st
) >= 0) {
1359 fprintf(stderr
, "Running %s %s\n", _PATH_BSHELL
,
1360 _PATH_SSH_SYSTEM_RC
);
1361 f
= popen(_PATH_BSHELL
" " _PATH_SSH_SYSTEM_RC
, "w");
1364 fprintf(f
, "%s %s\n", s
->auth_proto
,
1368 fprintf(stderr
, "Could not run %s\n",
1369 _PATH_SSH_SYSTEM_RC
);
1370 } else if (do_xauth
&& options
.xauth_location
!= NULL
) {
1371 /* Add authority data to .Xauthority if appropriate. */
1374 "Running %.500s remove %.100s\n",
1375 options
.xauth_location
, s
->auth_display
);
1377 "%.500s add %.100s %.100s %.100s\n",
1378 options
.xauth_location
, s
->auth_display
,
1379 s
->auth_proto
, s
->auth_data
);
1381 snprintf(cmd
, sizeof cmd
, "%s -q -",
1382 options
.xauth_location
);
1383 f
= popen(cmd
, "w");
1385 fprintf(f
, "remove %s\n",
1387 fprintf(f
, "add %s %s %s\n",
1388 s
->auth_display
, s
->auth_proto
,
1392 fprintf(stderr
, "Could not run %s\n",
1399 do_nologin(struct passwd
*pw
)
1404 #ifdef HAVE_LOGIN_CAP
1405 if (!login_getcapbool(lc
, "ignorenologin", 0) && pw
->pw_uid
)
1406 f
= fopen(login_getcapstr(lc
, "nologin", _PATH_NOLOGIN
,
1407 _PATH_NOLOGIN
), "r");
1410 f
= fopen(_PATH_NOLOGIN
, "r");
1413 /* /etc/nologin exists. Print its contents and exit. */
1414 logit("User %.100s not allowed because %s exists",
1415 pw
->pw_name
, _PATH_NOLOGIN
);
1416 while (fgets(buf
, sizeof(buf
), f
))
1425 * Chroot into a directory after checking it for safety: all path components
1426 * must be root-owned directories with strict permissions.
1429 safely_chroot(const char *path
, uid_t uid
)
1432 char component
[MAXPATHLEN
];
1436 fatal("chroot path does not begin at root");
1437 if (strlen(path
) >= sizeof(component
))
1438 fatal("chroot path too long");
1441 * Descend the path, checking that each component is a
1442 * root-owned directory with strict permissions.
1444 for (cp
= path
; cp
!= NULL
;) {
1445 if ((cp
= strchr(cp
, '/')) == NULL
)
1446 strlcpy(component
, path
, sizeof(component
));
1449 memcpy(component
, path
, cp
- path
);
1450 component
[cp
- path
] = '\0';
1453 debug3("%s: checking '%s'", __func__
, component
);
1455 if (stat(component
, &st
) != 0)
1456 fatal("%s: stat(\"%s\"): %s", __func__
,
1457 component
, strerror(errno
));
1458 if (st
.st_uid
!= 0 || (st
.st_mode
& 022) != 0)
1459 fatal("bad ownership or modes for chroot "
1460 "directory %s\"%s\"",
1461 cp
== NULL
? "" : "component ", component
);
1462 if (!S_ISDIR(st
.st_mode
))
1463 fatal("chroot path %s\"%s\" is not a directory",
1464 cp
== NULL
? "" : "component ", component
);
1468 if (chdir(path
) == -1)
1469 fatal("Unable to chdir to chroot path \"%s\": "
1470 "%s", path
, strerror(errno
));
1471 if (chroot(path
) == -1)
1472 fatal("chroot(\"%s\"): %s", path
, strerror(errno
));
1473 if (chdir("/") == -1)
1474 fatal("%s: chdir(/) after chroot: %s",
1475 __func__
, strerror(errno
));
1476 verbose("Changed root directory to \"%s\"", path
);
1479 /* Set login name, uid, gid, and groups. */
1481 do_setusercontext(struct passwd
*pw
)
1483 char *chroot_path
, *tmp
;
1486 /* Cache selinux status for later use */
1487 (void)ssh_selinux_enabled();
1491 if (getuid() == 0 || geteuid() == 0)
1492 #endif /* HAVE_CYGWIN */
1495 #ifdef HAVE_SETPCRED
1496 if (setpcred(pw
->pw_name
, (char **)NULL
) == -1)
1497 fatal("Failed to set process credentials");
1498 #endif /* HAVE_SETPCRED */
1499 #ifdef HAVE_LOGIN_CAP
1504 if (options
.use_pam
) {
1505 do_pam_setcred(use_privsep
);
1507 # endif /* USE_PAM */
1508 if (setusercontext(lc
, pw
, pw
->pw_uid
,
1509 (LOGIN_SETALL
& ~(LOGIN_SETPATH
|LOGIN_SETUSER
))) < 0) {
1510 perror("unable to set user context");
1514 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1515 /* Sets login uid for accounting */
1516 if (getluid() == -1 && setluid(pw
->pw_uid
) == -1)
1517 error("setluid: %s", strerror(errno
));
1518 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1520 if (setlogin(pw
->pw_name
) < 0)
1521 error("setlogin failed: %s", strerror(errno
));
1522 if (setgid(pw
->pw_gid
) < 0) {
1526 /* Initialize the group list. */
1527 if (initgroups(pw
->pw_name
, pw
->pw_gid
) < 0) {
1528 perror("initgroups");
1534 * PAM credentials may take the form of supplementary groups.
1535 * These will have been wiped by the above initgroups() call.
1536 * Reestablish them here.
1538 if (options
.use_pam
) {
1539 do_pam_setcred(use_privsep
);
1541 # endif /* USE_PAM */
1542 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1543 irix_setusercontext(pw
);
1544 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1549 if (set_id(pw
->pw_name
) != 0) {
1552 # endif /* USE_LIBIAF */
1555 if (options
.chroot_directory
!= NULL
&&
1556 strcasecmp(options
.chroot_directory
, "none") != 0) {
1557 tmp
= tilde_expand_filename(options
.chroot_directory
,
1559 chroot_path
= percent_expand(tmp
, "h", pw
->pw_dir
,
1560 "u", pw
->pw_name
, (char *)NULL
);
1561 safely_chroot(chroot_path
, pw
->pw_uid
);
1566 #ifdef HAVE_LOGIN_CAP
1567 if (setusercontext(lc
, pw
, pw
->pw_uid
, LOGIN_SETUSER
) < 0) {
1568 perror("unable to set user context (setuser)");
1572 /* Permanently switch to the desired uid. */
1573 permanently_set_uid(pw
);
1580 if (getuid() != pw
->pw_uid
|| geteuid() != pw
->pw_uid
)
1581 fatal("Failed to set uids to %u.", (u_int
) pw
->pw_uid
);
1584 ssh_selinux_setup_exec_context(pw
->pw_name
);
1589 do_pwchange(Session
*s
)
1592 fprintf(stderr
, "WARNING: Your password has expired.\n");
1593 if (s
->ttyfd
!= -1) {
1595 "You must change your password now and login again!\n");
1596 #ifdef PASSWD_NEEDS_USERNAME
1597 execl(_PATH_PASSWD_PROG
, "passwd", s
->pw
->pw_name
,
1600 execl(_PATH_PASSWD_PROG
, "passwd", (char *)NULL
);
1605 "Password change required but no TTY available.\n");
1611 launch_login(struct passwd
*pw
, const char *hostname
)
1613 /* Launch login(1). */
1615 execl(LOGIN_PROGRAM
, "login", "-h", hostname
,
1616 #ifdef xxxLOGIN_NEEDS_TERM
1617 (s
->term
? s
->term
: "unknown"),
1618 #endif /* LOGIN_NEEDS_TERM */
1619 #ifdef LOGIN_NO_ENDOPT
1620 "-p", "-f", pw
->pw_name
, (char *)NULL
);
1622 "-p", "-f", "--", pw
->pw_name
, (char *)NULL
);
1625 /* Login couldn't be executed, die. */
1632 child_close_fds(void)
1636 if (packet_get_connection_in() == packet_get_connection_out())
1637 close(packet_get_connection_in());
1639 close(packet_get_connection_in());
1640 close(packet_get_connection_out());
1643 * Close all descriptors related to channels. They will still remain
1644 * open in the parent.
1646 /* XXX better use close-on-exec? -markus */
1647 channel_close_all();
1650 * Close any extra file descriptors. Note that there may still be
1651 * descriptors left by system functions. They will be closed later.
1656 * Close any extra open file descriptors so that we don't have them
1657 * hanging around in clients. Note that we want to do this after
1658 * initgroups, because at least on Solaris 2.3 it leaves file
1661 for (i
= 3; i
< 64; i
++)
1666 * Performs common processing for the child, such as setting up the
1667 * environment, closing extra file descriptors, setting the user and group
1668 * ids, and executing the command or shell.
1672 do_child(Session
*s
, const char *command
)
1674 extern char **environ
;
1676 char *argv
[ARGV_MAX
];
1677 const char *shell
, *shell0
, *hostname
= NULL
;
1678 struct passwd
*pw
= s
->pw
;
1681 /* remove hostkey from the child's memory */
1682 destroy_sensitive_data();
1684 /* Force a password change */
1685 if (s
->authctxt
->force_pwchange
) {
1686 do_setusercontext(pw
);
1692 /* login(1) is only called if we execute the login shell */
1693 if (options
.use_login
&& command
!= NULL
)
1694 options
.use_login
= 0;
1697 cray_setup(pw
->pw_uid
, pw
->pw_name
, command
);
1698 #endif /* _UNICOS */
1701 * Login(1) does this as well, and it needs uid 0 for the "-h"
1702 * switch, so we let login(1) to this for us.
1704 if (!options
.use_login
) {
1706 session_setup_sia(pw
, s
->ttyfd
== -1 ? NULL
: s
->tty
);
1707 if (!check_quietlogin(s
, command
))
1709 #else /* HAVE_OSF_SIA */
1710 /* When PAM is enabled we rely on it to do the nologin check */
1711 if (!options
.use_pam
)
1713 do_setusercontext(pw
);
1715 * PAM session modules in do_setusercontext may have
1716 * generated messages, so if this in an interactive
1717 * login then display them too.
1719 if (!check_quietlogin(s
, command
))
1721 #endif /* HAVE_OSF_SIA */
1725 if (options
.use_pam
&& !options
.use_login
&& !is_pam_session_open()) {
1726 debug3("PAM session not opened, exiting");
1733 * Get the shell from the password data. An empty shell field is
1734 * legal, and means /bin/sh.
1736 shell
= (pw
->pw_shell
[0] == '\0') ? _PATH_BSHELL
: pw
->pw_shell
;
1739 * Make sure $SHELL points to the shell from the password file,
1740 * even if shell is overridden from login.conf
1742 env
= do_setup_env(s
, shell
);
1744 #ifdef HAVE_LOGIN_CAP
1745 shell
= login_getcapstr(lc
, "shell", (char *)shell
, (char *)shell
);
1748 /* we have to stash the hostname before we close our socket. */
1749 if (options
.use_login
)
1750 hostname
= get_remote_name_or_ip(utmp_len
,
1753 * Close the connection descriptors; note that this is the child, and
1754 * the server will still have the socket open, and it is important
1755 * that we do not shutdown it. Note that the descriptors cannot be
1756 * closed before building the environment, as we call
1757 * get_remote_ipaddr there.
1762 * Must take new environment into use so that .ssh/rc,
1763 * /etc/ssh/sshrc and xauth are run in the proper environment.
1767 #if defined(KRB5) && defined(USE_AFS)
1769 * At this point, we check to see if AFS is active and if we have
1770 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1771 * if we can (and need to) extend the ticket into an AFS token. If
1772 * we don't do this, we run into potential problems if the user's
1773 * home directory is in AFS and it's not world-readable.
1776 if (options
.kerberos_get_afs_token
&& k_hasafs() &&
1777 (s
->authctxt
->krb5_ctx
!= NULL
)) {
1780 debug("Getting AFS token");
1784 if (k_afs_cell_of_file(pw
->pw_dir
, cell
, sizeof(cell
)) == 0)
1785 krb5_afslog(s
->authctxt
->krb5_ctx
,
1786 s
->authctxt
->krb5_fwd_ccache
, cell
, NULL
);
1788 krb5_afslog_home(s
->authctxt
->krb5_ctx
,
1789 s
->authctxt
->krb5_fwd_ccache
, NULL
, NULL
, pw
->pw_dir
);
1793 /* Change current directory to the user's home directory. */
1794 if (chdir(pw
->pw_dir
) < 0) {
1795 /* Suppress missing homedir warning for chroot case */
1796 #ifdef HAVE_LOGIN_CAP
1797 r
= login_getcapbool(lc
, "requirehome", 0);
1799 if (r
|| options
.chroot_directory
== NULL
)
1800 fprintf(stderr
, "Could not chdir to home "
1801 "directory %s: %s\n", pw
->pw_dir
,
1807 closefrom(STDERR_FILENO
+ 1);
1809 if (!options
.use_login
)
1810 do_rc_files(s
, shell
);
1812 /* restore SIGPIPE for child */
1813 signal(SIGPIPE
, SIG_DFL
);
1815 if (s
->is_subsystem
== SUBSYSTEM_INT_SFTP
) {
1816 extern int optind
, optreset
;
1820 setproctitle("%s@internal-sftp-server", s
->pw
->pw_name
);
1821 args
= strdup(command
? command
: "sftp-server");
1822 for (i
= 0, (p
= strtok(args
, " ")); p
; (p
= strtok(NULL
, " ")))
1823 if (i
< ARGV_MAX
- 1)
1826 optind
= optreset
= 1;
1827 __progname
= argv
[0];
1828 exit(sftp_server_main(i
, argv
, s
->pw
));
1831 if (options
.use_login
) {
1832 launch_login(pw
, hostname
);
1836 /* Get the last component of the shell name. */
1837 if ((shell0
= strrchr(shell
, '/')) != NULL
)
1843 * If we have no command, execute the shell. In this case, the shell
1844 * name to be passed in argv[0] is preceded by '-' to indicate that
1845 * this is a login shell.
1850 /* Start the shell. Set initial character to '-'. */
1853 if (strlcpy(argv0
+ 1, shell0
, sizeof(argv0
) - 1)
1854 >= sizeof(argv0
) - 1) {
1860 /* Execute the shell. */
1863 execve(shell
, argv
, env
);
1865 /* Executing the shell failed. */
1870 * Execute the command using the user's shell. This uses the -c
1871 * option to execute the command.
1873 argv
[0] = (char *) shell0
;
1875 argv
[2] = (char *) command
;
1877 execve(shell
, argv
, env
);
1883 session_unused(int id
)
1885 debug3("%s: session id %d unused", __func__
, id
);
1886 if (id
>= options
.max_sessions
||
1887 id
>= sessions_nalloc
) {
1888 fatal("%s: insane session id %d (max %d nalloc %d)",
1889 __func__
, id
, options
.max_sessions
, sessions_nalloc
);
1891 bzero(&sessions
[id
], sizeof(*sessions
));
1892 sessions
[id
].self
= id
;
1893 sessions
[id
].used
= 0;
1894 sessions
[id
].chanid
= -1;
1895 sessions
[id
].ptyfd
= -1;
1896 sessions
[id
].ttyfd
= -1;
1897 sessions
[id
].ptymaster
= -1;
1898 sessions
[id
].x11_chanids
= NULL
;
1899 sessions
[id
].next_unused
= sessions_first_unused
;
1900 sessions_first_unused
= id
;
1908 if (sessions_first_unused
== -1) {
1909 if (sessions_nalloc
>= options
.max_sessions
)
1911 debug2("%s: allocate (allocated %d max %d)",
1912 __func__
, sessions_nalloc
, options
.max_sessions
);
1913 tmp
= xrealloc(sessions
, sessions_nalloc
+ 1,
1916 error("%s: cannot allocate %d sessions",
1917 __func__
, sessions_nalloc
+ 1);
1921 session_unused(sessions_nalloc
++);
1924 if (sessions_first_unused
>= sessions_nalloc
||
1925 sessions_first_unused
< 0) {
1926 fatal("%s: insane first_unused %d max %d nalloc %d",
1927 __func__
, sessions_first_unused
, options
.max_sessions
,
1931 s
= &sessions
[sessions_first_unused
];
1933 fatal("%s: session %d already used",
1934 __func__
, sessions_first_unused
);
1936 sessions_first_unused
= s
->next_unused
;
1938 s
->next_unused
= -1;
1939 debug("session_new: session %d", s
->self
);
1948 for (i
= 0; i
< sessions_nalloc
; i
++) {
1949 Session
*s
= &sessions
[i
];
1951 debug("dump: used %d next_unused %d session %d %p "
1952 "channel %d pid %ld",
1963 session_open(Authctxt
*authctxt
, int chanid
)
1965 Session
*s
= session_new();
1966 debug("session_open: channel %d", chanid
);
1968 error("no more sessions");
1971 s
->authctxt
= authctxt
;
1972 s
->pw
= authctxt
->pw
;
1973 if (s
->pw
== NULL
|| !authctxt
->valid
)
1974 fatal("no user for session %d", s
->self
);
1975 debug("session_open: session %d: link with channel %d", s
->self
, chanid
);
1981 session_by_tty(char *tty
)
1984 for (i
= 0; i
< sessions_nalloc
; i
++) {
1985 Session
*s
= &sessions
[i
];
1986 if (s
->used
&& s
->ttyfd
!= -1 && strcmp(s
->tty
, tty
) == 0) {
1987 debug("session_by_tty: session %d tty %s", i
, tty
);
1991 debug("session_by_tty: unknown tty %.100s", tty
);
1997 session_by_channel(int id
)
2000 for (i
= 0; i
< sessions_nalloc
; i
++) {
2001 Session
*s
= &sessions
[i
];
2002 if (s
->used
&& s
->chanid
== id
) {
2003 debug("session_by_channel: session %d channel %d",
2008 debug("session_by_channel: unknown channel %d", id
);
2014 session_by_x11_channel(int id
)
2018 for (i
= 0; i
< sessions_nalloc
; i
++) {
2019 Session
*s
= &sessions
[i
];
2021 if (s
->x11_chanids
== NULL
|| !s
->used
)
2023 for (j
= 0; s
->x11_chanids
[j
] != -1; j
++) {
2024 if (s
->x11_chanids
[j
] == id
) {
2025 debug("session_by_x11_channel: session %d "
2026 "channel %d", s
->self
, id
);
2031 debug("session_by_x11_channel: unknown channel %d", id
);
2037 session_by_pid(pid_t pid
)
2040 debug("session_by_pid: pid %ld", (long)pid
);
2041 for (i
= 0; i
< sessions_nalloc
; i
++) {
2042 Session
*s
= &sessions
[i
];
2043 if (s
->used
&& s
->pid
== pid
)
2046 error("session_by_pid: unknown pid %ld", (long)pid
);
2052 session_window_change_req(Session
*s
)
2054 s
->col
= packet_get_int();
2055 s
->row
= packet_get_int();
2056 s
->xpixel
= packet_get_int();
2057 s
->ypixel
= packet_get_int();
2059 pty_change_window_size(s
->ptyfd
, s
->row
, s
->col
, s
->xpixel
, s
->ypixel
);
2064 session_pty_req(Session
*s
)
2070 debug("Allocating a pty not permitted for this authentication.");
2073 if (s
->ttyfd
!= -1) {
2074 packet_disconnect("Protocol error: you already have a pty.");
2078 s
->term
= packet_get_string(&len
);
2081 s
->col
= packet_get_int();
2082 s
->row
= packet_get_int();
2084 s
->row
= packet_get_int();
2085 s
->col
= packet_get_int();
2087 s
->xpixel
= packet_get_int();
2088 s
->ypixel
= packet_get_int();
2090 if (strcmp(s
->term
, "") == 0) {
2095 /* Allocate a pty and open it. */
2096 debug("Allocating pty.");
2097 if (!PRIVSEP(pty_allocate(&s
->ptyfd
, &s
->ttyfd
, s
->tty
,
2104 error("session_pty_req: session %d alloc failed", s
->self
);
2107 debug("session_pty_req: session %d alloc %s", s
->self
, s
->tty
);
2109 /* for SSH1 the tty modes length is not given */
2111 n_bytes
= packet_remaining();
2112 tty_parse_modes(s
->ttyfd
, &n_bytes
);
2115 pty_setowner(s
->pw
, s
->tty
);
2117 /* Set window size from the packet. */
2118 pty_change_window_size(s
->ptyfd
, s
->row
, s
->col
, s
->xpixel
, s
->ypixel
);
2121 session_proctitle(s
);
2126 session_subsystem_req(Session
*s
)
2131 char *prog
, *cmd
, *subsys
= packet_get_string(&len
);
2135 logit("subsystem request for %.100s", subsys
);
2137 for (i
= 0; i
< options
.num_subsystems
; i
++) {
2138 if (strcmp(subsys
, options
.subsystem_name
[i
]) == 0) {
2139 prog
= options
.subsystem_command
[i
];
2140 cmd
= options
.subsystem_args
[i
];
2141 if (!strcmp(INTERNAL_SFTP_NAME
, prog
)) {
2142 s
->is_subsystem
= SUBSYSTEM_INT_SFTP
;
2143 } else if (stat(prog
, &st
) < 0) {
2144 error("subsystem: cannot stat %s: %s", prog
,
2148 s
->is_subsystem
= SUBSYSTEM_EXT
;
2150 debug("subsystem: exec() %s", cmd
);
2151 success
= do_exec(s
, cmd
) == 0;
2157 logit("subsystem request for %.100s failed, subsystem not found",
2165 session_x11_req(Session
*s
)
2169 if (s
->auth_proto
!= NULL
|| s
->auth_data
!= NULL
) {
2170 error("session_x11_req: session %d: "
2171 "x11 forwarding already active", s
->self
);
2174 s
->single_connection
= packet_get_char();
2175 s
->auth_proto
= packet_get_string(NULL
);
2176 s
->auth_data
= packet_get_string(NULL
);
2177 s
->screen
= packet_get_int();
2180 success
= session_setup_x11fwd(s
);
2182 xfree(s
->auth_proto
);
2183 xfree(s
->auth_data
);
2184 s
->auth_proto
= NULL
;
2185 s
->auth_data
= NULL
;
2191 session_shell_req(Session
*s
)
2194 return do_exec(s
, NULL
) == 0;
2198 session_exec_req(Session
*s
)
2202 char *command
= packet_get_string(&len
);
2204 success
= do_exec(s
, command
) == 0;
2210 session_break_req(Session
*s
)
2213 packet_get_int(); /* ignored */
2216 if (s
->ttyfd
== -1 || tcsendbreak(s
->ttyfd
, 0) < 0)
2222 session_env_req(Session
*s
)
2225 u_int name_len
, val_len
, i
;
2227 name
= packet_get_string(&name_len
);
2228 val
= packet_get_string(&val_len
);
2231 /* Don't set too many environment variables */
2232 if (s
->num_env
> 128) {
2233 debug2("Ignoring env request %s: too many env vars", name
);
2237 for (i
= 0; i
< options
.num_accept_env
; i
++) {
2238 if (match_pattern(name
, options
.accept_env
[i
])) {
2239 debug2("Setting env %d: %s=%s", s
->num_env
, name
, val
);
2240 s
->env
= xrealloc(s
->env
, s
->num_env
+ 1,
2242 s
->env
[s
->num_env
].name
= name
;
2243 s
->env
[s
->num_env
].val
= val
;
2248 debug2("Ignoring env request %s: disallowed name", name
);
2257 session_auth_agent_req(Session
*s
)
2259 static int called
= 0;
2261 if (no_agent_forwarding_flag
|| !options
.allow_agent_forwarding
) {
2262 debug("session_auth_agent_req: no_agent_forwarding_flag");
2269 return auth_input_request_forwarding(s
->pw
);
2274 session_input_channel_req(Channel
*c
, const char *rtype
)
2279 if ((s
= session_by_channel(c
->self
)) == NULL
) {
2280 logit("session_input_channel_req: no session %d req %.100s",
2284 debug("session_input_channel_req: session %d req %s", s
->self
, rtype
);
2287 * a session is in LARVAL state until a shell, a command
2288 * or a subsystem is executed
2290 if (c
->type
== SSH_CHANNEL_LARVAL
) {
2291 if (strcmp(rtype
, "shell") == 0) {
2292 success
= session_shell_req(s
);
2293 } else if (strcmp(rtype
, "exec") == 0) {
2294 success
= session_exec_req(s
);
2295 } else if (strcmp(rtype
, "pty-req") == 0) {
2296 success
= session_pty_req(s
);
2297 } else if (strcmp(rtype
, "x11-req") == 0) {
2298 success
= session_x11_req(s
);
2299 } else if (strcmp(rtype
, "auth-agent-req@openssh.com") == 0) {
2300 success
= session_auth_agent_req(s
);
2301 } else if (strcmp(rtype
, "subsystem") == 0) {
2302 success
= session_subsystem_req(s
);
2303 } else if (strcmp(rtype
, "env") == 0) {
2304 success
= session_env_req(s
);
2307 if (strcmp(rtype
, "window-change") == 0) {
2308 success
= session_window_change_req(s
);
2309 } else if (strcmp(rtype
, "break") == 0) {
2310 success
= session_break_req(s
);
2317 session_set_fds(Session
*s
, int fdin
, int fdout
, int fderr
, int is_tty
)
2320 fatal("session_set_fds: called for proto != 2.0");
2322 * now that have a child and a pipe to the child,
2323 * we can activate our channel and register the fd's
2325 if (s
->chanid
== -1)
2326 fatal("no channel for session %d", s
->self
);
2327 channel_set_fds(s
->chanid
,
2329 fderr
== -1 ? CHAN_EXTENDED_IGNORE
: CHAN_EXTENDED_READ
,
2330 1, is_tty
, CHAN_SES_WINDOW_DEFAULT
);
2334 * Function to perform pty cleanup. Also called if we get aborted abnormally
2335 * (e.g., due to a dropped connection).
2338 session_pty_cleanup2(Session
*s
)
2341 error("session_pty_cleanup: no session");
2347 debug("session_pty_cleanup: session %d release %s", s
->self
, s
->tty
);
2349 /* Record that the user has logged out. */
2351 record_logout(s
->pid
, s
->tty
, s
->pw
->pw_name
);
2353 /* Release the pseudo-tty. */
2355 pty_release(s
->tty
);
2358 * Close the server side of the socket pairs. We must do this after
2359 * the pty cleanup, so that another process doesn't get this pty
2360 * while we're still cleaning up.
2362 if (s
->ptymaster
!= -1 && close(s
->ptymaster
) < 0)
2363 error("close(s->ptymaster/%d): %s",
2364 s
->ptymaster
, strerror(errno
));
2366 /* unlink pty from session */
2371 session_pty_cleanup(Session
*s
)
2373 PRIVSEP(session_pty_cleanup2(s
));
2379 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2394 return "SIG@openssh.com";
2398 session_close_x11(int id
)
2402 if ((c
= channel_by_id(id
)) == NULL
) {
2403 debug("session_close_x11: x11 channel %d missing", id
);
2405 /* Detach X11 listener */
2406 debug("session_close_x11: detach x11 channel %d", id
);
2407 channel_cancel_cleanup(id
);
2408 if (c
->ostate
!= CHAN_OUTPUT_CLOSED
)
2414 session_close_single_x11(int id
, void *arg
)
2419 debug3("session_close_single_x11: channel %d", id
);
2420 channel_cancel_cleanup(id
);
2421 if ((s
= session_by_x11_channel(id
)) == NULL
)
2422 fatal("session_close_single_x11: no x11 channel %d", id
);
2423 for (i
= 0; s
->x11_chanids
[i
] != -1; i
++) {
2424 debug("session_close_single_x11: session %d: "
2425 "closing channel %d", s
->self
, s
->x11_chanids
[i
]);
2427 * The channel "id" is already closing, but make sure we
2428 * close all of its siblings.
2430 if (s
->x11_chanids
[i
] != id
)
2431 session_close_x11(s
->x11_chanids
[i
]);
2433 xfree(s
->x11_chanids
);
2434 s
->x11_chanids
= NULL
;
2439 if (s
->auth_proto
) {
2440 xfree(s
->auth_proto
);
2441 s
->auth_proto
= NULL
;
2444 xfree(s
->auth_data
);
2445 s
->auth_data
= NULL
;
2447 if (s
->auth_display
) {
2448 xfree(s
->auth_display
);
2449 s
->auth_display
= NULL
;
2454 session_exit_message(Session
*s
, int status
)
2458 if ((c
= channel_lookup(s
->chanid
)) == NULL
)
2459 fatal("session_exit_message: session %d: no channel %d",
2460 s
->self
, s
->chanid
);
2461 debug("session_exit_message: session %d channel %d pid %ld",
2462 s
->self
, s
->chanid
, (long)s
->pid
);
2464 if (WIFEXITED(status
)) {
2465 channel_request_start(s
->chanid
, "exit-status", 0);
2466 packet_put_int(WEXITSTATUS(status
));
2468 } else if (WIFSIGNALED(status
)) {
2469 channel_request_start(s
->chanid
, "exit-signal", 0);
2470 packet_put_cstring(sig2name(WTERMSIG(status
)));
2472 packet_put_char(WCOREDUMP(status
)? 1 : 0);
2473 #else /* WCOREDUMP */
2475 #endif /* WCOREDUMP */
2476 packet_put_cstring("");
2477 packet_put_cstring("");
2480 /* Some weird exit cause. Just exit. */
2481 packet_disconnect("wait returned status %04x.", status
);
2484 /* disconnect channel */
2485 debug("session_exit_message: release channel %d", s
->chanid
);
2488 * Adjust cleanup callback attachment to send close messages when
2489 * the channel gets EOF. The session will be then be closed
2490 * by session_close_by_channel when the childs close their fds.
2492 channel_register_cleanup(c
->self
, session_close_by_channel
, 1);
2495 * emulate a write failure with 'chan_write_failed', nobody will be
2496 * interested in data we write.
2497 * Note that we must not call 'chan_read_failed', since there could
2498 * be some more data waiting in the pipe.
2500 if (c
->ostate
!= CHAN_OUTPUT_CLOSED
)
2501 chan_write_failed(c
);
2505 session_close(Session
*s
)
2509 debug("session_close: session %d pid %ld", s
->self
, (long)s
->pid
);
2511 session_pty_cleanup(s
);
2517 xfree(s
->x11_chanids
);
2518 if (s
->auth_display
)
2519 xfree(s
->auth_display
);
2521 xfree(s
->auth_data
);
2523 xfree(s
->auth_proto
);
2524 if (s
->env
!= NULL
) {
2525 for (i
= 0; i
< s
->num_env
; i
++) {
2526 xfree(s
->env
[i
].name
);
2527 xfree(s
->env
[i
].val
);
2531 session_proctitle(s
);
2532 session_unused(s
->self
);
2536 session_close_by_pid(pid_t pid
, int status
)
2538 Session
*s
= session_by_pid(pid
);
2540 debug("session_close_by_pid: no session for pid %ld",
2544 if (s
->chanid
!= -1)
2545 session_exit_message(s
, status
);
2547 session_pty_cleanup(s
);
2552 * this is called when a channel dies before
2553 * the session 'child' itself dies
2556 session_close_by_channel(int id
, void *arg
)
2558 Session
*s
= session_by_channel(id
);
2562 debug("session_close_by_channel: no session for id %d", id
);
2565 debug("session_close_by_channel: channel %d child %ld",
2568 debug("session_close_by_channel: channel %d: has child", id
);
2570 * delay detach of session, but release pty, since
2571 * the fd's to the child are already closed
2574 session_pty_cleanup(s
);
2577 /* detach by removing callback */
2578 channel_cancel_cleanup(s
->chanid
);
2580 /* Close any X11 listeners associated with this session */
2581 if (s
->x11_chanids
!= NULL
) {
2582 for (i
= 0; s
->x11_chanids
[i
] != -1; i
++) {
2583 session_close_x11(s
->x11_chanids
[i
]);
2584 s
->x11_chanids
[i
] = -1;
2593 session_destroy_all(void (*closefunc
)(Session
*))
2596 for (i
= 0; i
< sessions_nalloc
; i
++) {
2597 Session
*s
= &sessions
[i
];
2599 if (closefunc
!= NULL
)
2608 session_tty_list(void)
2610 static char buf
[1024];
2615 for (i
= 0; i
< sessions_nalloc
; i
++) {
2616 Session
*s
= &sessions
[i
];
2617 if (s
->used
&& s
->ttyfd
!= -1) {
2619 if (strncmp(s
->tty
, "/dev/", 5) != 0) {
2620 cp
= strrchr(s
->tty
, '/');
2621 cp
= (cp
== NULL
) ? s
->tty
: cp
+ 1;
2626 strlcat(buf
, ",", sizeof buf
);
2627 strlcat(buf
, cp
, sizeof buf
);
2631 strlcpy(buf
, "notty", sizeof buf
);
2636 session_proctitle(Session
*s
)
2639 error("no user for session %d", s
->self
);
2641 setproctitle("%s@%s", s
->pw
->pw_name
, session_tty_list());
2645 session_setup_x11fwd(Session
*s
)
2648 char display
[512], auth_display
[512];
2649 char hostname
[MAXHOSTNAMELEN
];
2652 if (no_x11_forwarding_flag
) {
2653 packet_send_debug("X11 forwarding disabled in user configuration file.");
2656 if (!options
.x11_forwarding
) {
2657 debug("X11 forwarding disabled in server configuration file.");
2660 if (!options
.xauth_location
||
2661 (stat(options
.xauth_location
, &st
) == -1)) {
2662 packet_send_debug("No xauth program; cannot forward with spoofing.");
2665 if (options
.use_login
) {
2666 packet_send_debug("X11 forwarding disabled; "
2667 "not compatible with UseLogin=yes.");
2670 if (s
->display
!= NULL
) {
2671 debug("X11 display already set.");
2674 if (x11_create_display_inet(options
.x11_display_offset
,
2675 options
.x11_use_localhost
, s
->single_connection
,
2676 &s
->display_number
, &s
->x11_chanids
) == -1) {
2677 debug("x11_create_display_inet failed.");
2680 for (i
= 0; s
->x11_chanids
[i
] != -1; i
++) {
2681 channel_register_cleanup(s
->x11_chanids
[i
],
2682 session_close_single_x11
, 0);
2685 /* Set up a suitable value for the DISPLAY variable. */
2686 if (gethostname(hostname
, sizeof(hostname
)) < 0)
2687 fatal("gethostname: %.100s", strerror(errno
));
2689 * auth_display must be used as the displayname when the
2690 * authorization entry is added with xauth(1). This will be
2691 * different than the DISPLAY string for localhost displays.
2693 if (options
.x11_use_localhost
) {
2694 snprintf(display
, sizeof display
, "localhost:%u.%u",
2695 s
->display_number
, s
->screen
);
2696 snprintf(auth_display
, sizeof auth_display
, "unix:%u.%u",
2697 s
->display_number
, s
->screen
);
2698 s
->display
= xstrdup(display
);
2699 s
->auth_display
= xstrdup(auth_display
);
2701 #ifdef IPADDR_IN_DISPLAY
2703 struct in_addr my_addr
;
2705 he
= gethostbyname(hostname
);
2707 error("Can't get IP address for X11 DISPLAY.");
2708 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2711 memcpy(&my_addr
, he
->h_addr_list
[0], sizeof(struct in_addr
));
2712 snprintf(display
, sizeof display
, "%.50s:%u.%u", inet_ntoa(my_addr
),
2713 s
->display_number
, s
->screen
);
2715 snprintf(display
, sizeof display
, "%.400s:%u.%u", hostname
,
2716 s
->display_number
, s
->screen
);
2718 s
->display
= xstrdup(display
);
2719 s
->auth_display
= xstrdup(display
);
2726 do_authenticated2(Authctxt
*authctxt
)
2728 server_loop2(authctxt
);
2732 do_cleanup(Authctxt
*authctxt
)
2734 static int called
= 0;
2736 debug("do_cleanup");
2738 /* no cleanup if we're in the child for login shell */
2742 /* avoid double cleanup */
2747 if (authctxt
== NULL
)
2751 if (options
.use_pam
) {
2753 sshpam_thread_cleanup();
2757 if (!authctxt
->authenticated
)
2761 if (options
.kerberos_ticket_cleanup
&&
2763 krb5_cleanup_proc(authctxt
);
2767 if (compat20
&& options
.gss_cleanup_creds
)
2768 ssh_gssapi_cleanup_creds();
2771 /* remove agent socket */
2772 auth_sock_cleanup_proc(authctxt
->pw
);
2775 * Cleanup ptys/utmp only if privsep is disabled,
2776 * or if running in monitor.
2778 if (!use_privsep
|| mm_is_monitor())
2779 session_destroy_all(session_pty_cleanup2
);