2 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * As far as I am concerned, the code I have written for this software
6 * can be used freely for any purpose. Any derived versions of this
7 * software must be clearly marked as such, and if the derived work is
8 * incompatible with the protocol description in the RFC file, it must be
9 * called by a name other than "ssh" or "Secure Shell".
11 * SSH2 support by Markus Friedl.
12 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 RCSID("$OpenBSD: session.c,v 1.193 2006/02/10 01:44:27 stevesk Exp $");
38 #include <sys/types.h>
56 #include "auth-options.h"
57 #include "pathnames.h"
61 #include "serverloop.h"
65 #include "monitor_wrap.h"
67 #if defined(KRB5) && defined(USE_AFS)
77 Session *session_new(void);
78 void session_set_fds(Session *, int, int, int);
79 void session_pty_cleanup(Session *);
80 void session_proctitle(Session *);
81 int session_setup_x11fwd(Session *);
82 void do_exec_pty(Session *, const char *);
83 void do_exec_no_pty(Session *, const char *);
84 void do_exec(Session *, const char *);
85 void do_login(Session *, const char *);
86 #ifdef LOGIN_NEEDS_UTMPX
87 static void do_pre_login(Session *s);
89 void do_child(Session *, const char *);
91 int check_quietlogin(Session *, const char *);
93 static void do_authenticated1(Authctxt *);
94 static void do_authenticated2(Authctxt *);
96 static int session_pty_req(Session *);
99 extern ServerOptions options;
100 extern char *__progname;
101 extern int log_stderr;
102 extern int debug_flag;
103 extern u_int utmp_len;
104 extern int startup_pipe;
105 extern void destroy_sensitive_data(void);
106 extern Buffer loginmsg;
108 /* original command from peer. */
109 const char *original_command = NULL;
112 #define MAX_SESSIONS 10
113 Session sessions[MAX_SESSIONS];
115 #ifdef HAVE_LOGIN_CAP
119 static int is_child = 0;
121 /* Name and directory of socket for authentication agent forwarding. */
122 static char *auth_sock_name = NULL;
123 static char *auth_sock_dir = NULL;
125 /* removes the agent forwarding socket */
128 auth_sock_cleanup_proc(struct passwd *pw)
130 if (auth_sock_name != NULL) {
131 temporarily_use_uid(pw);
132 unlink(auth_sock_name);
133 rmdir(auth_sock_dir);
134 auth_sock_name = NULL;
140 auth_input_request_forwarding(struct passwd * pw)
144 struct sockaddr_un sunaddr;
146 if (auth_sock_name != NULL) {
147 error("authentication forwarding requested twice.");
151 /* Temporarily drop privileged uid for mkdir/bind. */
152 temporarily_use_uid(pw);
154 /* Allocate a buffer for the socket name, and format the name. */
155 auth_sock_name = xmalloc(MAXPATHLEN);
156 auth_sock_dir = xmalloc(MAXPATHLEN);
157 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
159 /* Create private directory for socket */
160 if (mkdtemp(auth_sock_dir) == NULL) {
161 packet_send_debug("Agent forwarding disabled: "
162 "mkdtemp() failed: %.100s", strerror(errno));
164 xfree(auth_sock_name);
165 xfree(auth_sock_dir);
166 auth_sock_name = NULL;
167 auth_sock_dir = NULL;
170 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
171 auth_sock_dir, (long) getpid());
173 /* Create the socket. */
174 sock = socket(AF_UNIX, SOCK_STREAM, 0);
176 packet_disconnect("socket: %.100s", strerror(errno));
178 /* Bind it to the name. */
179 memset(&sunaddr, 0, sizeof(sunaddr));
180 sunaddr.sun_family = AF_UNIX;
181 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
183 if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
184 packet_disconnect("bind: %.100s", strerror(errno));
186 /* Restore the privileged uid. */
189 /* Start listening on the socket. */
190 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
191 packet_disconnect("listen: %.100s", strerror(errno));
193 /* Allocate a channel for the authentication agent socket. */
194 nc = channel_new("auth socket",
195 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
196 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
197 0, "auth socket", 1);
198 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
203 display_loginmsg(void)
205 if (buffer_len(&loginmsg) > 0) {
206 buffer_append(&loginmsg, "\0", 1);
207 printf("%s", (char *)buffer_ptr(&loginmsg));
208 buffer_clear(&loginmsg);
213 do_authenticated(Authctxt *authctxt)
215 setproctitle("%s", authctxt->pw->pw_name);
217 /* setup the channel layer */
218 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
219 channel_permit_all_opens();
222 do_authenticated2(authctxt);
224 do_authenticated1(authctxt);
226 do_cleanup(authctxt);
230 * Prepares for an interactive session. This is called after the user has
231 * been successfully authenticated. During this message exchange, pseudo
232 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
233 * are requested, etc.
236 do_authenticated1(Authctxt *authctxt)
240 int success, type, screen_flag;
241 int enable_compression_after_reply = 0;
242 u_int proto_len, data_len, dlen, compression_level = 0;
246 error("no more sessions");
249 s->authctxt = authctxt;
250 s->pw = authctxt->pw;
253 * We stay in this loop until the client requests to execute a shell
259 /* Get a packet from the client. */
260 type = packet_read();
262 /* Process the packet. */
264 case SSH_CMSG_REQUEST_COMPRESSION:
265 compression_level = packet_get_int();
267 if (compression_level < 1 || compression_level > 9) {
268 packet_send_debug("Received invalid compression level %d.",
272 if (options.compression == COMP_NONE) {
273 debug2("compression disabled");
276 /* Enable compression after we have responded with SUCCESS. */
277 enable_compression_after_reply = 1;
281 case SSH_CMSG_REQUEST_PTY:
282 success = session_pty_req(s);
285 case SSH_CMSG_X11_REQUEST_FORWARDING:
286 s->auth_proto = packet_get_string(&proto_len);
287 s->auth_data = packet_get_string(&data_len);
289 screen_flag = packet_get_protocol_flags() &
290 SSH_PROTOFLAG_SCREEN_NUMBER;
291 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
293 if (packet_remaining() == 4) {
295 debug2("Buggy client: "
296 "X11 screen flag missing");
297 s->screen = packet_get_int();
302 success = session_setup_x11fwd(s);
304 xfree(s->auth_proto);
306 s->auth_proto = NULL;
311 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
312 if (no_agent_forwarding_flag || compat13) {
313 debug("Authentication agent forwarding not permitted for this authentication.");
316 debug("Received authentication agent forwarding request.");
317 success = auth_input_request_forwarding(s->pw);
320 case SSH_CMSG_PORT_FORWARD_REQUEST:
321 if (no_port_forwarding_flag) {
322 debug("Port forwarding not permitted for this authentication.");
325 if (!options.allow_tcp_forwarding) {
326 debug("Port forwarding not permitted.");
329 debug("Received TCP/IP port forwarding request.");
330 channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
334 case SSH_CMSG_MAX_PACKET_SIZE:
335 if (packet_set_maxsize(packet_get_int()) > 0)
339 case SSH_CMSG_EXEC_SHELL:
340 case SSH_CMSG_EXEC_CMD:
341 if (type == SSH_CMSG_EXEC_CMD) {
342 command = packet_get_string(&dlen);
343 debug("Exec command '%.500s'", command);
355 * Any unknown messages in this phase are ignored,
356 * and a failure message is returned.
358 logit("Unknown packet type received after authentication: %d", type);
360 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
364 /* Enable compression now that we have replied if appropriate. */
365 if (enable_compression_after_reply) {
366 enable_compression_after_reply = 0;
367 packet_start_compression(compression_level);
373 * This is called to fork and execute a command when we have no tty. This
374 * will call do_child from the child, and server_loop from the parent after
375 * setting up file descriptors and such.
378 do_exec_no_pty(Session *s, const char *command)
383 int pin[2], pout[2], perr[2];
384 /* Allocate pipes for communicating with the program. */
385 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
386 packet_disconnect("Could not create pipes: %.100s",
388 #else /* USE_PIPES */
389 int inout[2], err[2];
390 /* Uses socket pairs to communicate with the program. */
391 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
392 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
393 packet_disconnect("Could not create socket pairs: %.100s",
395 #endif /* USE_PIPES */
397 fatal("do_exec_no_pty: no session");
399 session_proctitle(s);
402 if (options.use_pam && !use_privsep)
406 /* Fork the child. */
407 if ((pid = fork()) == 0) {
410 /* Child. Reinitialize the log since the pid has changed. */
411 log_init(__progname, options.log_level, options.log_facility, log_stderr);
414 * Create a new session and process group since the 4.4BSD
415 * setlogin() affects the entire process group.
418 error("setsid failed: %.100s", strerror(errno));
422 * Redirect stdin. We close the parent side of the socket
423 * pair, and make the child side the standard input.
426 if (dup2(pin[0], 0) < 0)
427 perror("dup2 stdin");
430 /* Redirect stdout. */
432 if (dup2(pout[1], 1) < 0)
433 perror("dup2 stdout");
436 /* Redirect stderr. */
438 if (dup2(perr[1], 2) < 0)
439 perror("dup2 stderr");
441 #else /* USE_PIPES */
443 * Redirect stdin, stdout, and stderr. Stdin and stdout will
444 * use the same socket, as some programs (particularly rdist)
445 * seem to depend on it.
449 if (dup2(inout[0], 0) < 0) /* stdin */
450 perror("dup2 stdin");
451 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
452 perror("dup2 stdout");
453 if (dup2(err[0], 2) < 0) /* stderr */
454 perror("dup2 stderr");
455 #endif /* USE_PIPES */
458 cray_init_job(s->pw); /* set up cray jid and tmpdir */
461 /* Do processing for the child (exec command etc). */
462 do_child(s, command);
466 signal(WJSIGNAL, cray_job_termination_handler);
470 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
473 packet_disconnect("fork failed: %.100s", strerror(errno));
475 /* Set interactive/non-interactive mode. */
476 packet_set_interactive(s->display != NULL);
478 /* We are the parent. Close the child sides of the pipes. */
484 if (s->is_subsystem) {
488 session_set_fds(s, pin[1], pout[0], perr[0]);
490 /* Enter the interactive session. */
491 server_loop(pid, pin[1], pout[0], perr[0]);
492 /* server_loop has closed pin[1], pout[0], and perr[0]. */
494 #else /* USE_PIPES */
495 /* We are the parent. Close the child sides of the socket pairs. */
500 * Clear loginmsg, since it's the child's responsibility to display
501 * it to the user, otherwise multiple sessions may accumulate
502 * multiple copies of the login messages.
504 buffer_clear(&loginmsg);
507 * Enter the interactive session. Note: server_loop must be able to
508 * handle the case that fdin and fdout are the same.
511 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
513 server_loop(pid, inout[1], inout[1], err[1]);
514 /* server_loop has closed inout[1] and err[1]. */
516 #endif /* USE_PIPES */
520 * This is called to fork and execute a command when we have a tty. This
521 * will call do_child from the child, and server_loop from the parent after
522 * setting up file descriptors, controlling tty, updating wtmp, utmp,
523 * lastlog, and other such operations.
526 do_exec_pty(Session *s, const char *command)
528 int fdout, ptyfd, ttyfd, ptymaster;
532 fatal("do_exec_pty: no session");
537 if (options.use_pam) {
538 do_pam_set_tty(s->tty);
544 /* Fork the child. */
545 if ((pid = fork()) == 0) {
548 /* Child. Reinitialize the log because the pid has changed. */
549 log_init(__progname, options.log_level, options.log_facility, log_stderr);
550 /* Close the master side of the pseudo tty. */
553 /* Make the pseudo tty our controlling tty. */
554 pty_make_controlling_tty(&ttyfd, s->tty);
556 /* Redirect stdin/stdout/stderr from the pseudo tty. */
557 if (dup2(ttyfd, 0) < 0)
558 error("dup2 stdin: %s", strerror(errno));
559 if (dup2(ttyfd, 1) < 0)
560 error("dup2 stdout: %s", strerror(errno));
561 if (dup2(ttyfd, 2) < 0)
562 error("dup2 stderr: %s", strerror(errno));
564 /* Close the extra descriptor for the pseudo tty. */
567 /* record login, etc. similar to login(1) */
569 if (!(options.use_login && command == NULL)) {
571 cray_init_job(s->pw); /* set up cray jid and tmpdir */
573 do_login(s, command);
575 # ifdef LOGIN_NEEDS_UTMPX
581 /* Do common processing for the child, such as execing the command. */
582 do_child(s, command);
586 signal(WJSIGNAL, cray_job_termination_handler);
590 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
593 packet_disconnect("fork failed: %.100s", strerror(errno));
596 /* Parent. Close the slave side of the pseudo tty. */
600 * Create another descriptor of the pty master side for use as the
601 * standard input. We could use the original descriptor, but this
602 * simplifies code in server_loop. The descriptor is bidirectional.
606 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
608 /* we keep a reference to the pty master */
609 ptymaster = dup(ptyfd);
611 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
612 s->ptymaster = ptymaster;
614 /* Enter interactive session. */
615 packet_set_interactive(1);
617 session_set_fds(s, ptyfd, fdout, -1);
619 server_loop(pid, ptyfd, fdout, -1);
620 /* server_loop _has_ closed ptyfd and fdout. */
624 #ifdef LOGIN_NEEDS_UTMPX
626 do_pre_login(Session *s)
629 struct sockaddr_storage from;
630 pid_t pid = getpid();
633 * Get IP address of client. If the connection is not a socket, let
634 * the address be 0.0.0.0.
636 memset(&from, 0, sizeof(from));
637 fromlen = sizeof(from);
638 if (packet_connection_is_on_socket()) {
639 if (getpeername(packet_get_connection_in(),
640 (struct sockaddr *) & from, &fromlen) < 0) {
641 debug("getpeername: %.100s", strerror(errno));
646 record_utmp_only(pid, s->tty, s->pw->pw_name,
647 get_remote_name_or_ip(utmp_len, options.use_dns),
648 (struct sockaddr *)&from, fromlen);
653 * This is called to fork and execute a command. If another command is
654 * to be forced, execute that instead.
657 do_exec(Session *s, const char *command)
659 if (forced_command) {
660 original_command = command;
661 command = forced_command;
662 debug("Forced command '%.900s'", command);
665 #ifdef SSH_AUDIT_EVENTS
667 PRIVSEP(audit_run_command(command));
668 else if (s->ttyfd == -1) {
669 char *shell = s->pw->pw_shell;
671 if (shell[0] == '\0') /* empty shell means /bin/sh */
673 PRIVSEP(audit_run_command(shell));
678 do_exec_pty(s, command);
680 do_exec_no_pty(s, command);
682 original_command = NULL;
685 * Clear loginmsg: it's the child's responsibility to display
686 * it to the user, otherwise multiple sessions may accumulate
687 * multiple copies of the login messages.
689 buffer_clear(&loginmsg);
692 /* administrative, login(1)-like work */
694 do_login(Session *s, const char *command)
697 struct sockaddr_storage from;
698 struct passwd * pw = s->pw;
699 pid_t pid = getpid();
702 * Get IP address of client. If the connection is not a socket, let
703 * the address be 0.0.0.0.
705 memset(&from, 0, sizeof(from));
706 fromlen = sizeof(from);
707 if (packet_connection_is_on_socket()) {
708 if (getpeername(packet_get_connection_in(),
709 (struct sockaddr *) & from, &fromlen) < 0) {
710 debug("getpeername: %.100s", strerror(errno));
715 /* Record that there was a login on that tty from the remote host. */
717 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
718 get_remote_name_or_ip(utmp_len,
720 (struct sockaddr *)&from, fromlen);
724 * If password change is needed, do it now.
725 * This needs to occur before the ~/.hushlogin check.
727 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
730 s->authctxt->force_pwchange = 0;
731 /* XXX - signal [net] parent to enable forwardings */
735 if (check_quietlogin(s, command))
744 * Display the message of the day.
752 if (options.print_motd) {
753 #ifdef HAVE_LOGIN_CAP
754 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
757 f = fopen("/etc/motd", "r");
760 while (fgets(buf, sizeof(buf), f))
769 * Check for quiet login, either .hushlogin or command given.
772 check_quietlogin(Session *s, const char *command)
775 struct passwd *pw = s->pw;
778 /* Return 1 if .hushlogin exists or a command given. */
781 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
782 #ifdef HAVE_LOGIN_CAP
783 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
786 if (stat(buf, &st) >= 0)
793 * Sets the value of the given variable in the environment. If the variable
794 * already exists, its value is overriden.
797 child_set_env(char ***envp, u_int *envsizep, const char *name,
805 * If we're passed an uninitialized list, allocate a single null
806 * entry before continuing.
808 if (*envp == NULL && *envsizep == 0) {
809 *envp = xmalloc(sizeof(char *));
815 * Find the slot where the value should be stored. If the variable
816 * already exists, we reuse the slot; otherwise we append a new slot
817 * at the end of the array, expanding if necessary.
820 namelen = strlen(name);
821 for (i = 0; env[i]; i++)
822 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
825 /* Reuse the slot. */
828 /* New variable. Expand if necessary. */
830 if (i >= envsize - 1) {
832 fatal("child_set_env: too many env vars");
834 env = (*envp) = xrealloc(env, envsize * sizeof(char *));
837 /* Need to set the NULL pointer at end of array beyond the new slot. */
841 /* Allocate space and format the variable in the appropriate slot. */
842 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
843 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
847 * Reads environment variables from the given file and adds/overrides them
848 * into the environment. If the file does not exist, this does nothing.
849 * Otherwise, it must consist of empty lines, comments (line starts with '#')
850 * and assignments of the form name=value. No other forms are allowed.
853 read_environment_file(char ***env, u_int *envsize,
854 const char *filename)
861 f = fopen(filename, "r");
865 while (fgets(buf, sizeof(buf), f)) {
867 fatal("Too many lines in environment file %s", filename);
868 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
870 if (!*cp || *cp == '#' || *cp == '\n')
872 if (strchr(cp, '\n'))
873 *strchr(cp, '\n') = '\0';
874 value = strchr(cp, '=');
876 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
881 * Replace the equals sign by nul, and advance value to
886 child_set_env(env, envsize, cp, value);
891 #ifdef HAVE_ETC_DEFAULT_LOGIN
893 * Return named variable from specified environment, or NULL if not present.
896 child_get_env(char **env, const char *name)
902 for (i=0; env[i] != NULL; i++)
903 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
904 return(env[i] + len + 1);
909 * Read /etc/default/login.
910 * We pick up the PATH (or SUPATH for root) and UMASK.
913 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
915 char **tmpenv = NULL, *var;
916 u_int i, tmpenvsize = 0;
920 * We don't want to copy the whole file to the child's environment,
921 * so we use a temporary environment and copy the variables we're
924 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
930 var = child_get_env(tmpenv, "SUPATH");
932 var = child_get_env(tmpenv, "PATH");
934 child_set_env(env, envsize, "PATH", var);
936 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
937 if (sscanf(var, "%5lo", &mask) == 1)
940 for (i = 0; tmpenv[i] != NULL; i++)
944 #endif /* HAVE_ETC_DEFAULT_LOGIN */
947 copy_environment(char **source, char ***env, u_int *envsize)
949 char *var_name, *var_val;
955 for(i = 0; source[i] != NULL; i++) {
956 var_name = xstrdup(source[i]);
957 if ((var_val = strstr(var_name, "=")) == NULL) {
963 debug3("Copy environment: %s=%s", var_name, var_val);
964 child_set_env(env, envsize, var_name, var_val);
971 do_setup_env(Session *s, const char *shell)
975 char **env, *laddr, *path = NULL;
976 struct passwd *pw = s->pw;
978 /* Initialize the environment. */
980 env = xmalloc(envsize * sizeof(char *));
985 * The Windows environment contains some setting which are
986 * important for a running system. They must not be dropped.
991 p = fetch_windows_environment();
992 copy_environment(p, &env, &envsize);
993 free_windows_environment(p);
998 /* Allow any GSSAPI methods that we've used to alter
999 * the childs environment as they see fit
1001 ssh_gssapi_do_child(&env, &envsize);
1004 if (!options.use_login) {
1005 /* Set basic environment. */
1006 for (i = 0; i < s->num_env; i++)
1007 child_set_env(&env, &envsize, s->env[i].name,
1010 child_set_env(&env, &envsize, "USER", pw->pw_name);
1011 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1013 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1015 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1016 #ifdef HAVE_LOGIN_CAP
1017 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1018 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1020 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1021 #else /* HAVE_LOGIN_CAP */
1022 # ifndef HAVE_CYGWIN
1024 * There's no standard path on Windows. The path contains
1025 * important components pointing to the system directories,
1026 * needed for loading shared libraries. So the path better
1027 * remains intact here.
1029 # ifdef HAVE_ETC_DEFAULT_LOGIN
1030 read_etc_default_login(&env, &envsize, pw->pw_uid);
1031 path = child_get_env(env, "PATH");
1032 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1033 if (path == NULL || *path == '\0') {
1034 child_set_env(&env, &envsize, "PATH",
1035 s->pw->pw_uid == 0 ?
1036 SUPERUSER_PATH : _PATH_STDPATH);
1038 # endif /* HAVE_CYGWIN */
1039 #endif /* HAVE_LOGIN_CAP */
1041 snprintf(buf, sizeof buf, "%.200s/%.50s",
1042 _PATH_MAILDIR, pw->pw_name);
1043 child_set_env(&env, &envsize, "MAIL", buf);
1045 /* Normal systems set SHELL by default. */
1046 child_set_env(&env, &envsize, "SHELL", shell);
1049 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1051 /* Set custom environment options from RSA authentication. */
1052 if (!options.use_login) {
1053 while (custom_environment) {
1054 struct envstring *ce = custom_environment;
1057 for (i = 0; str[i] != '=' && str[i]; i++)
1059 if (str[i] == '=') {
1061 child_set_env(&env, &envsize, str, str + i + 1);
1063 custom_environment = ce->next;
1069 /* SSH_CLIENT deprecated */
1070 snprintf(buf, sizeof buf, "%.50s %d %d",
1071 get_remote_ipaddr(), get_remote_port(), get_local_port());
1072 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1074 laddr = get_local_ipaddr(packet_get_connection_in());
1075 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1076 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1078 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1081 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1083 child_set_env(&env, &envsize, "TERM", s->term);
1085 child_set_env(&env, &envsize, "DISPLAY", s->display);
1086 if (original_command)
1087 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1091 if (cray_tmpdir[0] != '\0')
1092 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1093 #endif /* _UNICOS */
1096 * Since we clear KRB5CCNAME at startup, if it's set now then it
1097 * must have been set by a native authentication method (eg AIX or
1098 * SIA), so copy it to the child.
1103 if ((cp = getenv("KRB5CCNAME")) != NULL)
1104 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1111 if ((cp = getenv("AUTHSTATE")) != NULL)
1112 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1113 read_environment_file(&env, &envsize, "/etc/environment");
1117 if (s->authctxt->krb5_ccname)
1118 child_set_env(&env, &envsize, "KRB5CCNAME",
1119 s->authctxt->krb5_ccname);
1123 * Pull in any environment variables that may have
1126 if (options.use_pam) {
1129 p = fetch_pam_child_environment();
1130 copy_environment(p, &env, &envsize);
1131 free_pam_environment(p);
1133 p = fetch_pam_environment();
1134 copy_environment(p, &env, &envsize);
1135 free_pam_environment(p);
1137 #endif /* USE_PAM */
1139 if (auth_sock_name != NULL)
1140 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1143 /* read $HOME/.ssh/environment. */
1144 if (options.permit_user_env && !options.use_login) {
1145 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1146 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1147 read_environment_file(&env, &envsize, buf);
1150 /* dump the environment */
1151 fprintf(stderr, "Environment:\n");
1152 for (i = 0; env[i]; i++)
1153 fprintf(stderr, " %.200s\n", env[i]);
1159 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1160 * first in this order).
1163 do_rc_files(Session *s, const char *shell)
1171 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1173 /* ignore _PATH_SSH_USER_RC for subsystems */
1174 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1175 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1176 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1178 fprintf(stderr, "Running %s\n", cmd);
1179 f = popen(cmd, "w");
1182 fprintf(f, "%s %s\n", s->auth_proto,
1186 fprintf(stderr, "Could not run %s\n",
1188 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1190 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1191 _PATH_SSH_SYSTEM_RC);
1192 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1195 fprintf(f, "%s %s\n", s->auth_proto,
1199 fprintf(stderr, "Could not run %s\n",
1200 _PATH_SSH_SYSTEM_RC);
1201 } else if (do_xauth && options.xauth_location != NULL) {
1202 /* Add authority data to .Xauthority if appropriate. */
1205 "Running %.500s remove %.100s\n",
1206 options.xauth_location, s->auth_display);
1208 "%.500s add %.100s %.100s %.100s\n",
1209 options.xauth_location, s->auth_display,
1210 s->auth_proto, s->auth_data);
1212 snprintf(cmd, sizeof cmd, "%s -q -",
1213 options.xauth_location);
1214 f = popen(cmd, "w");
1216 fprintf(f, "remove %s\n",
1218 fprintf(f, "add %s %s %s\n",
1219 s->auth_display, s->auth_proto,
1223 fprintf(stderr, "Could not run %s\n",
1230 do_nologin(struct passwd *pw)
1235 #ifdef HAVE_LOGIN_CAP
1236 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1237 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1238 _PATH_NOLOGIN), "r");
1241 f = fopen(_PATH_NOLOGIN, "r");
1244 /* /etc/nologin exists. Print its contents and exit. */
1245 logit("User %.100s not allowed because %s exists",
1246 pw->pw_name, _PATH_NOLOGIN);
1247 while (fgets(buf, sizeof(buf), f))
1255 /* Set login name, uid, gid, and groups. */
1257 do_setusercontext(struct passwd *pw)
1260 if (getuid() == 0 || geteuid() == 0)
1261 #endif /* HAVE_CYGWIN */
1264 #ifdef HAVE_SETPCRED
1265 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1266 fatal("Failed to set process credentials");
1267 #endif /* HAVE_SETPCRED */
1268 #ifdef HAVE_LOGIN_CAP
1273 if (options.gss_authentication) {
1274 temporarily_use_uid(pw);
1275 ssh_gssapi_storecreds();
1280 if (options.use_pam) {
1284 # endif /* USE_PAM */
1285 if (setusercontext(lc, pw, pw->pw_uid,
1286 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1287 perror("unable to set user context");
1291 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1292 /* Sets login uid for accounting */
1293 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1294 error("setluid: %s", strerror(errno));
1295 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1297 if (setlogin(pw->pw_name) < 0)
1298 error("setlogin failed: %s", strerror(errno));
1299 if (setgid(pw->pw_gid) < 0) {
1303 /* Initialize the group list. */
1304 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1305 perror("initgroups");
1310 if (options.gss_authentication) {
1311 temporarily_use_uid(pw);
1312 ssh_gssapi_storecreds();
1318 * PAM credentials may take the form of supplementary groups.
1319 * These will have been wiped by the above initgroups() call.
1320 * Reestablish them here.
1322 if (options.use_pam) {
1326 # endif /* USE_PAM */
1327 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1328 irix_setusercontext(pw);
1329 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1333 #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
1334 if (set_id(pw->pw_name) != 0) {
1337 #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
1338 /* Permanently switch to the desired uid. */
1339 permanently_set_uid(pw);
1346 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1347 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1351 do_pwchange(Session *s)
1354 fprintf(stderr, "WARNING: Your password has expired.\n");
1355 if (s->ttyfd != -1) {
1357 "You must change your password now and login again!\n");
1358 #ifdef PASSWD_NEEDS_USERNAME
1359 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1362 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1367 "Password change required but no TTY available.\n");
1373 launch_login(struct passwd *pw, const char *hostname)
1375 /* Launch login(1). */
1377 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1378 #ifdef xxxLOGIN_NEEDS_TERM
1379 (s->term ? s->term : "unknown"),
1380 #endif /* LOGIN_NEEDS_TERM */
1381 #ifdef LOGIN_NO_ENDOPT
1382 "-p", "-f", pw->pw_name, (char *)NULL);
1384 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1387 /* Login couldn't be executed, die. */
1394 child_close_fds(void)
1398 if (packet_get_connection_in() == packet_get_connection_out())
1399 close(packet_get_connection_in());
1401 close(packet_get_connection_in());
1402 close(packet_get_connection_out());
1405 * Close all descriptors related to channels. They will still remain
1406 * open in the parent.
1408 /* XXX better use close-on-exec? -markus */
1409 channel_close_all();
1412 * Close any extra file descriptors. Note that there may still be
1413 * descriptors left by system functions. They will be closed later.
1418 * Close any extra open file descriptors so that we don't have them
1419 * hanging around in clients. Note that we want to do this after
1420 * initgroups, because at least on Solaris 2.3 it leaves file
1423 for (i = 3; i < 64; i++)
1428 * Performs common processing for the child, such as setting up the
1429 * environment, closing extra file descriptors, setting the user and group
1430 * ids, and executing the command or shell.
1433 do_child(Session *s, const char *command)
1435 extern char **environ;
1438 const char *shell, *shell0, *hostname = NULL;
1439 struct passwd *pw = s->pw;
1441 /* remove hostkey from the child's memory */
1442 destroy_sensitive_data();
1444 /* Force a password change */
1445 if (s->authctxt->force_pwchange) {
1446 do_setusercontext(pw);
1452 /* login(1) is only called if we execute the login shell */
1453 if (options.use_login && command != NULL)
1454 options.use_login = 0;
1457 cray_setup(pw->pw_uid, pw->pw_name, command);
1458 #endif /* _UNICOS */
1461 * Login(1) does this as well, and it needs uid 0 for the "-h"
1462 * switch, so we let login(1) to this for us.
1464 if (!options.use_login) {
1466 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1467 if (!check_quietlogin(s, command))
1469 #else /* HAVE_OSF_SIA */
1470 /* When PAM is enabled we rely on it to do the nologin check */
1471 if (!options.use_pam)
1473 do_setusercontext(pw);
1475 * PAM session modules in do_setusercontext may have
1476 * generated messages, so if this in an interactive
1477 * login then display them too.
1479 if (!check_quietlogin(s, command))
1481 #endif /* HAVE_OSF_SIA */
1485 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1486 debug3("PAM session not opened, exiting");
1493 * Get the shell from the password data. An empty shell field is
1494 * legal, and means /bin/sh.
1496 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1499 * Make sure $SHELL points to the shell from the password file,
1500 * even if shell is overridden from login.conf
1502 env = do_setup_env(s, shell);
1504 #ifdef HAVE_LOGIN_CAP
1505 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1508 /* we have to stash the hostname before we close our socket. */
1509 if (options.use_login)
1510 hostname = get_remote_name_or_ip(utmp_len,
1513 * Close the connection descriptors; note that this is the child, and
1514 * the server will still have the socket open, and it is important
1515 * that we do not shutdown it. Note that the descriptors cannot be
1516 * closed before building the environment, as we call
1517 * get_remote_ipaddr there.
1522 * Must take new environment into use so that .ssh/rc,
1523 * /etc/ssh/sshrc and xauth are run in the proper environment.
1527 #if defined(KRB5) && defined(USE_AFS)
1529 * At this point, we check to see if AFS is active and if we have
1530 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1531 * if we can (and need to) extend the ticket into an AFS token. If
1532 * we don't do this, we run into potential problems if the user's
1533 * home directory is in AFS and it's not world-readable.
1536 if (options.kerberos_get_afs_token && k_hasafs() &&
1537 (s->authctxt->krb5_ctx != NULL)) {
1540 debug("Getting AFS token");
1544 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1545 krb5_afslog(s->authctxt->krb5_ctx,
1546 s->authctxt->krb5_fwd_ccache, cell, NULL);
1548 krb5_afslog_home(s->authctxt->krb5_ctx,
1549 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1553 /* Change current directory to the user's home directory. */
1554 if (chdir(pw->pw_dir) < 0) {
1555 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1556 pw->pw_dir, strerror(errno));
1557 #ifdef HAVE_LOGIN_CAP
1558 if (login_getcapbool(lc, "requirehome", 0))
1563 if (!options.use_login)
1564 do_rc_files(s, shell);
1566 /* restore SIGPIPE for child */
1567 signal(SIGPIPE, SIG_DFL);
1569 if (options.use_login) {
1570 launch_login(pw, hostname);
1574 /* Get the last component of the shell name. */
1575 if ((shell0 = strrchr(shell, '/')) != NULL)
1581 * If we have no command, execute the shell. In this case, the shell
1582 * name to be passed in argv[0] is preceded by '-' to indicate that
1583 * this is a login shell.
1588 /* Start the shell. Set initial character to '-'. */
1591 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1592 >= sizeof(argv0) - 1) {
1598 /* Execute the shell. */
1601 execve(shell, argv, env);
1603 /* Executing the shell failed. */
1608 * Execute the command using the user's shell. This uses the -c
1609 * option to execute the command.
1611 argv[0] = (char *) shell0;
1613 argv[2] = (char *) command;
1615 execve(shell, argv, env);
1624 static int did_init = 0;
1626 debug("session_new: init");
1627 for (i = 0; i < MAX_SESSIONS; i++) {
1628 sessions[i].used = 0;
1632 for (i = 0; i < MAX_SESSIONS; i++) {
1633 Session *s = &sessions[i];
1635 memset(s, 0, sizeof(*s));
1641 s->x11_chanids = NULL;
1642 debug("session_new: session %d", i);
1653 for (i = 0; i < MAX_SESSIONS; i++) {
1654 Session *s = &sessions[i];
1655 debug("dump: used %d session %d %p channel %d pid %ld",
1665 session_open(Authctxt *authctxt, int chanid)
1667 Session *s = session_new();
1668 debug("session_open: channel %d", chanid);
1670 error("no more sessions");
1673 s->authctxt = authctxt;
1674 s->pw = authctxt->pw;
1675 if (s->pw == NULL || !authctxt->valid)
1676 fatal("no user for session %d", s->self);
1677 debug("session_open: session %d: link with channel %d", s->self, chanid);
1683 session_by_tty(char *tty)
1686 for (i = 0; i < MAX_SESSIONS; i++) {
1687 Session *s = &sessions[i];
1688 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1689 debug("session_by_tty: session %d tty %s", i, tty);
1693 debug("session_by_tty: unknown tty %.100s", tty);
1699 session_by_channel(int id)
1702 for (i = 0; i < MAX_SESSIONS; i++) {
1703 Session *s = &sessions[i];
1704 if (s->used && s->chanid == id) {
1705 debug("session_by_channel: session %d channel %d", i, id);
1709 debug("session_by_channel: unknown channel %d", id);
1715 session_by_x11_channel(int id)
1719 for (i = 0; i < MAX_SESSIONS; i++) {
1720 Session *s = &sessions[i];
1722 if (s->x11_chanids == NULL || !s->used)
1724 for (j = 0; s->x11_chanids[j] != -1; j++) {
1725 if (s->x11_chanids[j] == id) {
1726 debug("session_by_x11_channel: session %d "
1727 "channel %d", s->self, id);
1732 debug("session_by_x11_channel: unknown channel %d", id);
1738 session_by_pid(pid_t pid)
1741 debug("session_by_pid: pid %ld", (long)pid);
1742 for (i = 0; i < MAX_SESSIONS; i++) {
1743 Session *s = &sessions[i];
1744 if (s->used && s->pid == pid)
1747 error("session_by_pid: unknown pid %ld", (long)pid);
1753 session_window_change_req(Session *s)
1755 s->col = packet_get_int();
1756 s->row = packet_get_int();
1757 s->xpixel = packet_get_int();
1758 s->ypixel = packet_get_int();
1760 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1765 session_pty_req(Session *s)
1771 debug("Allocating a pty not permitted for this authentication.");
1774 if (s->ttyfd != -1) {
1775 packet_disconnect("Protocol error: you already have a pty.");
1779 s->term = packet_get_string(&len);
1782 s->col = packet_get_int();
1783 s->row = packet_get_int();
1785 s->row = packet_get_int();
1786 s->col = packet_get_int();
1788 s->xpixel = packet_get_int();
1789 s->ypixel = packet_get_int();
1791 if (strcmp(s->term, "") == 0) {
1796 /* Allocate a pty and open it. */
1797 debug("Allocating pty.");
1798 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1804 error("session_pty_req: session %d alloc failed", s->self);
1807 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1809 /* for SSH1 the tty modes length is not given */
1811 n_bytes = packet_remaining();
1812 tty_parse_modes(s->ttyfd, &n_bytes);
1815 pty_setowner(s->pw, s->tty);
1817 /* Set window size from the packet. */
1818 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1821 session_proctitle(s);
1826 session_subsystem_req(Session *s)
1831 char *cmd, *subsys = packet_get_string(&len);
1835 logit("subsystem request for %.100s", subsys);
1837 for (i = 0; i < options.num_subsystems; i++) {
1838 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1839 cmd = options.subsystem_command[i];
1840 if (stat(cmd, &st) < 0) {
1841 error("subsystem: cannot stat %s: %s", cmd,
1845 debug("subsystem: exec() %s", cmd);
1846 s->is_subsystem = 1;
1854 logit("subsystem request for %.100s failed, subsystem not found",
1862 session_x11_req(Session *s)
1866 if (s->auth_proto != NULL || s->auth_data != NULL) {
1867 error("session_x11_req: session %d: "
1868 "x11 forwarding already active", s->self);
1871 s->single_connection = packet_get_char();
1872 s->auth_proto = packet_get_string(NULL);
1873 s->auth_data = packet_get_string(NULL);
1874 s->screen = packet_get_int();
1877 success = session_setup_x11fwd(s);
1879 xfree(s->auth_proto);
1880 xfree(s->auth_data);
1881 s->auth_proto = NULL;
1882 s->auth_data = NULL;
1888 session_shell_req(Session *s)
1896 session_exec_req(Session *s)
1899 char *command = packet_get_string(&len);
1901 do_exec(s, command);
1907 session_break_req(Session *s)
1910 packet_get_int(); /* ignored */
1913 if (s->ttyfd == -1 ||
1914 tcsendbreak(s->ttyfd, 0) < 0)
1920 session_env_req(Session *s)
1923 u_int name_len, val_len, i;
1925 name = packet_get_string(&name_len);
1926 val = packet_get_string(&val_len);
1929 /* Don't set too many environment variables */
1930 if (s->num_env > 128) {
1931 debug2("Ignoring env request %s: too many env vars", name);
1935 for (i = 0; i < options.num_accept_env; i++) {
1936 if (match_pattern(name, options.accept_env[i])) {
1937 debug2("Setting env %d: %s=%s", s->num_env, name, val);
1938 s->env = xrealloc(s->env, sizeof(*s->env) *
1940 s->env[s->num_env].name = name;
1941 s->env[s->num_env].val = val;
1946 debug2("Ignoring env request %s: disallowed name", name);
1955 session_auth_agent_req(Session *s)
1957 static int called = 0;
1959 if (no_agent_forwarding_flag) {
1960 debug("session_auth_agent_req: no_agent_forwarding_flag");
1967 return auth_input_request_forwarding(s->pw);
1972 session_input_channel_req(Channel *c, const char *rtype)
1977 if ((s = session_by_channel(c->self)) == NULL) {
1978 logit("session_input_channel_req: no session %d req %.100s",
1982 debug("session_input_channel_req: session %d req %s", s->self, rtype);
1985 * a session is in LARVAL state until a shell, a command
1986 * or a subsystem is executed
1988 if (c->type == SSH_CHANNEL_LARVAL) {
1989 if (strcmp(rtype, "shell") == 0) {
1990 success = session_shell_req(s);
1991 } else if (strcmp(rtype, "exec") == 0) {
1992 success = session_exec_req(s);
1993 } else if (strcmp(rtype, "pty-req") == 0) {
1994 success = session_pty_req(s);
1995 } else if (strcmp(rtype, "x11-req") == 0) {
1996 success = session_x11_req(s);
1997 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1998 success = session_auth_agent_req(s);
1999 } else if (strcmp(rtype, "subsystem") == 0) {
2000 success = session_subsystem_req(s);
2001 } else if (strcmp(rtype, "env") == 0) {
2002 success = session_env_req(s);
2005 if (strcmp(rtype, "window-change") == 0) {
2006 success = session_window_change_req(s);
2007 } else if (strcmp(rtype, "break") == 0) {
2008 success = session_break_req(s);
2015 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2018 fatal("session_set_fds: called for proto != 2.0");
2020 * now that have a child and a pipe to the child,
2021 * we can activate our channel and register the fd's
2023 if (s->chanid == -1)
2024 fatal("no channel for session %d", s->self);
2025 channel_set_fds(s->chanid,
2027 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2029 CHAN_SES_WINDOW_DEFAULT);
2033 * Function to perform pty cleanup. Also called if we get aborted abnormally
2034 * (e.g., due to a dropped connection).
2037 session_pty_cleanup2(Session *s)
2040 error("session_pty_cleanup: no session");
2046 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2048 /* Record that the user has logged out. */
2050 record_logout(s->pid, s->tty, s->pw->pw_name);
2052 /* Release the pseudo-tty. */
2054 pty_release(s->tty);
2057 * Close the server side of the socket pairs. We must do this after
2058 * the pty cleanup, so that another process doesn't get this pty
2059 * while we're still cleaning up.
2061 if (close(s->ptymaster) < 0)
2062 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2064 /* unlink pty from session */
2069 session_pty_cleanup(Session *s)
2071 PRIVSEP(session_pty_cleanup2(s));
2077 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2092 return "SIG@openssh.com";
2096 session_close_x11(int id)
2100 if ((c = channel_by_id(id)) == NULL) {
2101 debug("session_close_x11: x11 channel %d missing", id);
2103 /* Detach X11 listener */
2104 debug("session_close_x11: detach x11 channel %d", id);
2105 channel_cancel_cleanup(id);
2106 if (c->ostate != CHAN_OUTPUT_CLOSED)
2112 session_close_single_x11(int id, void *arg)
2117 debug3("session_close_single_x11: channel %d", id);
2118 channel_cancel_cleanup(id);
2119 if ((s = session_by_x11_channel(id)) == NULL)
2120 fatal("session_close_single_x11: no x11 channel %d", id);
2121 for (i = 0; s->x11_chanids[i] != -1; i++) {
2122 debug("session_close_single_x11: session %d: "
2123 "closing channel %d", s->self, s->x11_chanids[i]);
2125 * The channel "id" is already closing, but make sure we
2126 * close all of its siblings.
2128 if (s->x11_chanids[i] != id)
2129 session_close_x11(s->x11_chanids[i]);
2131 xfree(s->x11_chanids);
2132 s->x11_chanids = NULL;
2137 if (s->auth_proto) {
2138 xfree(s->auth_proto);
2139 s->auth_proto = NULL;
2142 xfree(s->auth_data);
2143 s->auth_data = NULL;
2145 if (s->auth_display) {
2146 xfree(s->auth_display);
2147 s->auth_display = NULL;
2152 session_exit_message(Session *s, int status)
2156 if ((c = channel_lookup(s->chanid)) == NULL)
2157 fatal("session_exit_message: session %d: no channel %d",
2158 s->self, s->chanid);
2159 debug("session_exit_message: session %d channel %d pid %ld",
2160 s->self, s->chanid, (long)s->pid);
2162 if (WIFEXITED(status)) {
2163 channel_request_start(s->chanid, "exit-status", 0);
2164 packet_put_int(WEXITSTATUS(status));
2166 } else if (WIFSIGNALED(status)) {
2167 channel_request_start(s->chanid, "exit-signal", 0);
2168 packet_put_cstring(sig2name(WTERMSIG(status)));
2170 packet_put_char(WCOREDUMP(status));
2171 #else /* WCOREDUMP */
2173 #endif /* WCOREDUMP */
2174 packet_put_cstring("");
2175 packet_put_cstring("");
2178 /* Some weird exit cause. Just exit. */
2179 packet_disconnect("wait returned status %04x.", status);
2182 /* disconnect channel */
2183 debug("session_exit_message: release channel %d", s->chanid);
2186 * Adjust cleanup callback attachment to send close messages when
2187 * the channel gets EOF. The session will be then be closed
2188 * by session_close_by_channel when the childs close their fds.
2190 channel_register_cleanup(c->self, session_close_by_channel, 1);
2193 * emulate a write failure with 'chan_write_failed', nobody will be
2194 * interested in data we write.
2195 * Note that we must not call 'chan_read_failed', since there could
2196 * be some more data waiting in the pipe.
2198 if (c->ostate != CHAN_OUTPUT_CLOSED)
2199 chan_write_failed(c);
2203 session_close(Session *s)
2207 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2209 session_pty_cleanup(s);
2215 xfree(s->x11_chanids);
2216 if (s->auth_display)
2217 xfree(s->auth_display);
2219 xfree(s->auth_data);
2221 xfree(s->auth_proto);
2223 for (i = 0; i < s->num_env; i++) {
2224 xfree(s->env[i].name);
2225 xfree(s->env[i].val);
2229 session_proctitle(s);
2233 session_close_by_pid(pid_t pid, int status)
2235 Session *s = session_by_pid(pid);
2237 debug("session_close_by_pid: no session for pid %ld",
2241 if (s->chanid != -1)
2242 session_exit_message(s, status);
2244 session_pty_cleanup(s);
2249 * this is called when a channel dies before
2250 * the session 'child' itself dies
2253 session_close_by_channel(int id, void *arg)
2255 Session *s = session_by_channel(id);
2259 debug("session_close_by_channel: no session for id %d", id);
2262 debug("session_close_by_channel: channel %d child %ld",
2265 debug("session_close_by_channel: channel %d: has child", id);
2267 * delay detach of session, but release pty, since
2268 * the fd's to the child are already closed
2271 session_pty_cleanup(s);
2274 /* detach by removing callback */
2275 channel_cancel_cleanup(s->chanid);
2277 /* Close any X11 listeners associated with this session */
2278 if (s->x11_chanids != NULL) {
2279 for (i = 0; s->x11_chanids[i] != -1; i++) {
2280 session_close_x11(s->x11_chanids[i]);
2281 s->x11_chanids[i] = -1;
2290 session_destroy_all(void (*closefunc)(Session *))
2293 for (i = 0; i < MAX_SESSIONS; i++) {
2294 Session *s = &sessions[i];
2296 if (closefunc != NULL)
2305 session_tty_list(void)
2307 static char buf[1024];
2312 for (i = 0; i < MAX_SESSIONS; i++) {
2313 Session *s = &sessions[i];
2314 if (s->used && s->ttyfd != -1) {
2316 if (strncmp(s->tty, "/dev/", 5) != 0) {
2317 cp = strrchr(s->tty, '/');
2318 cp = (cp == NULL) ? s->tty : cp + 1;
2323 strlcat(buf, ",", sizeof buf);
2324 strlcat(buf, cp, sizeof buf);
2328 strlcpy(buf, "notty", sizeof buf);
2333 session_proctitle(Session *s)
2336 error("no user for session %d", s->self);
2338 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2342 session_setup_x11fwd(Session *s)
2345 char display[512], auth_display[512];
2346 char hostname[MAXHOSTNAMELEN];
2349 if (no_x11_forwarding_flag) {
2350 packet_send_debug("X11 forwarding disabled in user configuration file.");
2353 if (!options.x11_forwarding) {
2354 debug("X11 forwarding disabled in server configuration file.");
2357 if (!options.xauth_location ||
2358 (stat(options.xauth_location, &st) == -1)) {
2359 packet_send_debug("No xauth program; cannot forward with spoofing.");
2362 if (options.use_login) {
2363 packet_send_debug("X11 forwarding disabled; "
2364 "not compatible with UseLogin=yes.");
2367 if (s->display != NULL) {
2368 debug("X11 display already set.");
2371 if (x11_create_display_inet(options.x11_display_offset,
2372 options.x11_use_localhost, s->single_connection,
2373 &s->display_number, &s->x11_chanids) == -1) {
2374 debug("x11_create_display_inet failed.");
2377 for (i = 0; s->x11_chanids[i] != -1; i++) {
2378 channel_register_cleanup(s->x11_chanids[i],
2379 session_close_single_x11, 0);
2382 /* Set up a suitable value for the DISPLAY variable. */
2383 if (gethostname(hostname, sizeof(hostname)) < 0)
2384 fatal("gethostname: %.100s", strerror(errno));
2386 * auth_display must be used as the displayname when the
2387 * authorization entry is added with xauth(1). This will be
2388 * different than the DISPLAY string for localhost displays.
2390 if (options.x11_use_localhost) {
2391 snprintf(display, sizeof display, "localhost:%u.%u",
2392 s->display_number, s->screen);
2393 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2394 s->display_number, s->screen);
2395 s->display = xstrdup(display);
2396 s->auth_display = xstrdup(auth_display);
2398 #ifdef IPADDR_IN_DISPLAY
2400 struct in_addr my_addr;
2402 he = gethostbyname(hostname);
2404 error("Can't get IP address for X11 DISPLAY.");
2405 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2408 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2409 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2410 s->display_number, s->screen);
2412 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2413 s->display_number, s->screen);
2415 s->display = xstrdup(display);
2416 s->auth_display = xstrdup(display);
2423 do_authenticated2(Authctxt *authctxt)
2425 server_loop2(authctxt);
2429 do_cleanup(Authctxt *authctxt)
2431 static int called = 0;
2433 debug("do_cleanup");
2435 /* no cleanup if we're in the child for login shell */
2439 /* avoid double cleanup */
2444 if (authctxt == NULL)
2447 if (options.kerberos_ticket_cleanup &&
2449 krb5_cleanup_proc(authctxt);
2453 if (compat20 && options.gss_cleanup_creds)
2454 ssh_gssapi_cleanup_creds();
2458 if (options.use_pam) {
2460 sshpam_thread_cleanup();
2464 /* remove agent socket */
2465 auth_sock_cleanup_proc(authctxt->pw);
2468 * Cleanup ptys/utmp only if privsep is disabled,
2469 * or if running in monitor.
2471 if (!use_privsep || mm_is_monitor())
2472 session_destroy_all(session_pty_cleanup2);