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 1.172 2004/01/30 09:48:57 markus Exp $");
51 #include "auth-options.h"
52 #include "pathnames.h"
56 #include "serverloop.h"
59 #include "monitor_wrap.h"
61 #if defined(KRB5) && defined(USE_AFS)
71 Session *session_new(void);
72 void session_set_fds(Session *, int, int, int);
73 void session_pty_cleanup(Session *);
74 void session_proctitle(Session *);
75 int session_setup_x11fwd(Session *);
76 void do_exec_pty(Session *, const char *);
77 void do_exec_no_pty(Session *, const char *);
78 void do_exec(Session *, const char *);
79 void do_login(Session *, const char *);
80 #ifdef LOGIN_NEEDS_UTMPX
81 static void do_pre_login(Session *s);
83 void do_child(Session *, const char *);
85 int check_quietlogin(Session *, const char *);
87 static void do_authenticated1(Authctxt *);
88 static void do_authenticated2(Authctxt *);
90 static int session_pty_req(Session *);
93 static void execute_session_hook(char* prog, Authctxt *authctxt,
94 int startup, int save);
98 extern ServerOptions options;
99 extern char *__progname;
100 extern int log_stderr;
101 extern int debug_flag;
102 extern u_int utmp_len;
103 extern int startup_pipe;
104 extern void destroy_sensitive_data(void);
105 extern Buffer loginmsg;
107 /* original command from peer. */
108 const char *original_command = NULL;
111 #define MAX_SESSIONS 10
112 Session sessions[MAX_SESSIONS];
114 #ifdef HAVE_LOGIN_CAP
118 static int is_child = 0;
120 /* Name and directory of socket for authentication agent forwarding. */
121 static char *auth_sock_name = NULL;
122 static char *auth_sock_dir = NULL;
124 /* removes the agent forwarding socket */
127 auth_sock_cleanup_proc(struct passwd *pw)
129 if (auth_sock_name != NULL) {
130 temporarily_use_uid(pw);
131 unlink(auth_sock_name);
132 rmdir(auth_sock_dir);
133 auth_sock_name = NULL;
139 auth_input_request_forwarding(struct passwd * pw)
143 struct sockaddr_un sunaddr;
145 if (auth_sock_name != NULL) {
146 error("authentication forwarding requested twice.");
150 /* Temporarily drop privileged uid for mkdir/bind. */
151 temporarily_use_uid(pw);
153 /* Allocate a buffer for the socket name, and format the name. */
154 auth_sock_name = xmalloc(MAXPATHLEN);
155 auth_sock_dir = xmalloc(MAXPATHLEN);
156 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
158 /* Create private directory for socket */
159 if (mkdtemp(auth_sock_dir) == NULL) {
160 packet_send_debug("Agent forwarding disabled: "
161 "mkdtemp() failed: %.100s", strerror(errno));
163 xfree(auth_sock_name);
164 xfree(auth_sock_dir);
165 auth_sock_name = NULL;
166 auth_sock_dir = NULL;
169 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
170 auth_sock_dir, (long) getpid());
172 /* Create the socket. */
173 sock = socket(AF_UNIX, SOCK_STREAM, 0);
175 packet_disconnect("socket: %.100s", strerror(errno));
177 /* Bind it to the name. */
178 memset(&sunaddr, 0, sizeof(sunaddr));
179 sunaddr.sun_family = AF_UNIX;
180 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
182 if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
183 packet_disconnect("bind: %.100s", strerror(errno));
185 /* Restore the privileged uid. */
188 /* Start listening on the socket. */
189 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
190 packet_disconnect("listen: %.100s", strerror(errno));
192 /* Allocate a channel for the authentication agent socket. */
193 nc = channel_new("auth socket",
194 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
195 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
196 0, "auth socket", 1);
197 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
202 display_loginmsg(void)
204 if (buffer_len(&loginmsg) > 0) {
205 buffer_append(&loginmsg, "\0", 1);
206 printf("%s\n", (char *)buffer_ptr(&loginmsg));
207 buffer_clear(&loginmsg);
212 do_authenticated(Authctxt *authctxt)
214 setproctitle("%s", authctxt->pw->pw_name);
217 * Cancel the alarm we set to limit the time taken for
221 if (startup_pipe != -1) {
225 /* setup the channel layer */
226 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
227 channel_permit_all_opens();
230 do_authenticated2(authctxt);
232 do_authenticated1(authctxt);
235 if (options.session_hooks_allow &&
236 options.session_hooks_shutdown_cmd)
238 execute_session_hook(options.session_hooks_shutdown_cmd,
240 /* startup = */ 0, /* save = */ 0);
242 if (authctxt->session_env_file)
244 free(authctxt->session_env_file);
249 do_cleanup(authctxt);
253 * Prepares for an interactive session. This is called after the user has
254 * been successfully authenticated. During this message exchange, pseudo
255 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
256 * are requested, etc.
259 do_authenticated1(Authctxt *authctxt)
263 int success, type, screen_flag;
264 int enable_compression_after_reply = 0;
265 u_int proto_len, data_len, dlen, compression_level = 0;
268 s->authctxt = authctxt;
269 s->pw = authctxt->pw;
272 * We stay in this loop until the client requests to execute a shell
278 /* Get a packet from the client. */
279 type = packet_read();
281 /* Process the packet. */
283 case SSH_CMSG_REQUEST_COMPRESSION:
284 compression_level = packet_get_int();
286 if (compression_level < 1 || compression_level > 9) {
287 packet_send_debug("Received illegal compression level %d.",
291 if (!options.compression) {
292 debug2("compression disabled");
295 /* Enable compression after we have responded with SUCCESS. */
296 enable_compression_after_reply = 1;
300 case SSH_CMSG_REQUEST_PTY:
301 success = session_pty_req(s);
304 case SSH_CMSG_X11_REQUEST_FORWARDING:
305 s->auth_proto = packet_get_string(&proto_len);
306 s->auth_data = packet_get_string(&data_len);
308 screen_flag = packet_get_protocol_flags() &
309 SSH_PROTOFLAG_SCREEN_NUMBER;
310 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
312 if (packet_remaining() == 4) {
314 debug2("Buggy client: "
315 "X11 screen flag missing");
316 s->screen = packet_get_int();
321 success = session_setup_x11fwd(s);
323 xfree(s->auth_proto);
325 s->auth_proto = NULL;
330 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
331 if (no_agent_forwarding_flag || compat13) {
332 debug("Authentication agent forwarding not permitted for this authentication.");
335 debug("Received authentication agent forwarding request.");
336 success = auth_input_request_forwarding(s->pw);
339 case SSH_CMSG_PORT_FORWARD_REQUEST:
340 if (no_port_forwarding_flag) {
341 debug("Port forwarding not permitted for this authentication.");
344 if (!options.allow_tcp_forwarding) {
345 debug("Port forwarding not permitted.");
348 debug("Received TCP/IP port forwarding request.");
349 channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
353 case SSH_CMSG_MAX_PACKET_SIZE:
354 if (packet_set_maxsize(packet_get_int()) > 0)
358 case SSH_CMSG_EXEC_SHELL:
359 case SSH_CMSG_EXEC_CMD:
360 if (type == SSH_CMSG_EXEC_CMD) {
361 command = packet_get_string(&dlen);
362 debug("Exec command '%.500s'", command);
374 * Any unknown messages in this phase are ignored,
375 * and a failure message is returned.
377 logit("Unknown packet type received after authentication: %d", type);
379 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
383 /* Enable compression now that we have replied if appropriate. */
384 if (enable_compression_after_reply) {
385 enable_compression_after_reply = 0;
386 packet_start_compression(compression_level);
392 * This is called to fork and execute a command when we have no tty. This
393 * will call do_child from the child, and server_loop from the parent after
394 * setting up file descriptors and such.
397 do_exec_no_pty(Session *s, const char *command)
402 int pin[2], pout[2], perr[2];
403 /* Allocate pipes for communicating with the program. */
404 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
405 packet_disconnect("Could not create pipes: %.100s",
407 #else /* USE_PIPES */
408 int inout[2], err[2];
409 /* Uses socket pairs to communicate with the program. */
410 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
411 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
412 packet_disconnect("Could not create socket pairs: %.100s",
414 #endif /* USE_PIPES */
416 fatal("do_exec_no_pty: no session");
418 session_proctitle(s);
421 if (options.use_pam && !use_privsep)
425 /* Fork the child. */
426 if ((pid = fork()) == 0) {
429 /* Child. Reinitialize the log since the pid has changed. */
430 log_init(__progname, options.log_level, options.log_facility, log_stderr);
433 * Create a new session and process group since the 4.4BSD
434 * setlogin() affects the entire process group.
437 error("setsid failed: %.100s", strerror(errno));
441 * Redirect stdin. We close the parent side of the socket
442 * pair, and make the child side the standard input.
445 if (dup2(pin[0], 0) < 0)
446 perror("dup2 stdin");
449 /* Redirect stdout. */
451 if (dup2(pout[1], 1) < 0)
452 perror("dup2 stdout");
455 /* Redirect stderr. */
457 if (dup2(perr[1], 2) < 0)
458 perror("dup2 stderr");
460 #else /* USE_PIPES */
462 * Redirect stdin, stdout, and stderr. Stdin and stdout will
463 * use the same socket, as some programs (particularly rdist)
464 * seem to depend on it.
468 if (dup2(inout[0], 0) < 0) /* stdin */
469 perror("dup2 stdin");
470 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
471 perror("dup2 stdout");
472 if (dup2(err[0], 2) < 0) /* stderr */
473 perror("dup2 stderr");
474 #endif /* USE_PIPES */
477 cray_init_job(s->pw); /* set up cray jid and tmpdir */
480 /* Do processing for the child (exec command etc). */
481 do_child(s, command);
485 signal(WJSIGNAL, cray_job_termination_handler);
489 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
492 packet_disconnect("fork failed: %.100s", strerror(errno));
494 /* Set interactive/non-interactive mode. */
495 packet_set_interactive(s->display != NULL);
497 /* We are the parent. Close the child sides of the pipes. */
503 session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
505 /* Enter the interactive session. */
506 server_loop(pid, pin[1], pout[0], perr[0]);
507 /* server_loop has closed pin[1], pout[0], and perr[0]. */
509 #else /* USE_PIPES */
510 /* We are the parent. Close the child sides of the socket pairs. */
515 * Enter the interactive session. Note: server_loop must be able to
516 * handle the case that fdin and fdout are the same.
519 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
521 server_loop(pid, inout[1], inout[1], err[1]);
522 /* server_loop has closed inout[1] and err[1]. */
524 #endif /* USE_PIPES */
528 * This is called to fork and execute a command when we have a tty. This
529 * will call do_child from the child, and server_loop from the parent after
530 * setting up file descriptors, controlling tty, updating wtmp, utmp,
531 * lastlog, and other such operations.
534 do_exec_pty(Session *s, const char *command)
536 int fdout, ptyfd, ttyfd, ptymaster;
540 fatal("do_exec_pty: no session");
545 if (options.use_pam) {
546 do_pam_set_tty(s->tty);
552 /* Fork the child. */
553 if ((pid = fork()) == 0) {
556 /* Child. Reinitialize the log because the pid has changed. */
557 log_init(__progname, options.log_level, options.log_facility, log_stderr);
558 /* Close the master side of the pseudo tty. */
561 /* Make the pseudo tty our controlling tty. */
562 pty_make_controlling_tty(&ttyfd, s->tty);
564 /* Redirect stdin/stdout/stderr from the pseudo tty. */
565 if (dup2(ttyfd, 0) < 0)
566 error("dup2 stdin: %s", strerror(errno));
567 if (dup2(ttyfd, 1) < 0)
568 error("dup2 stdout: %s", strerror(errno));
569 if (dup2(ttyfd, 2) < 0)
570 error("dup2 stderr: %s", strerror(errno));
572 /* Close the extra descriptor for the pseudo tty. */
575 /* record login, etc. similar to login(1) */
577 if (!(options.use_login && command == NULL)) {
579 cray_init_job(s->pw); /* set up cray jid and tmpdir */
581 do_login(s, command);
583 # ifdef LOGIN_NEEDS_UTMPX
589 /* Do common processing for the child, such as execing the command. */
590 do_child(s, command);
594 signal(WJSIGNAL, cray_job_termination_handler);
598 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
601 packet_disconnect("fork failed: %.100s", strerror(errno));
604 /* Parent. Close the slave side of the pseudo tty. */
608 * Create another descriptor of the pty master side for use as the
609 * standard input. We could use the original descriptor, but this
610 * simplifies code in server_loop. The descriptor is bidirectional.
614 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
616 /* we keep a reference to the pty master */
617 ptymaster = dup(ptyfd);
619 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
620 s->ptymaster = ptymaster;
622 /* Enter interactive session. */
623 packet_set_interactive(1);
625 session_set_fds(s, ptyfd, fdout, -1);
627 server_loop(pid, ptyfd, fdout, -1);
628 /* server_loop _has_ closed ptyfd and fdout. */
632 #ifdef LOGIN_NEEDS_UTMPX
634 do_pre_login(Session *s)
637 struct sockaddr_storage from;
638 pid_t pid = getpid();
641 * Get IP address of client. If the connection is not a socket, let
642 * the address be 0.0.0.0.
644 memset(&from, 0, sizeof(from));
645 fromlen = sizeof(from);
646 if (packet_connection_is_on_socket()) {
647 if (getpeername(packet_get_connection_in(),
648 (struct sockaddr *) & from, &fromlen) < 0) {
649 debug("getpeername: %.100s", strerror(errno));
654 record_utmp_only(pid, s->tty, s->pw->pw_name,
655 get_remote_name_or_ip(utmp_len, options.use_dns),
656 (struct sockaddr *)&from, fromlen);
661 * This is called to fork and execute a command. If another command is
662 * to be forced, execute that instead.
665 do_exec(Session *s, const char *command)
667 if (forced_command) {
668 original_command = command;
669 command = forced_command;
670 debug("Forced command '%.900s'", command);
673 #if defined(SESSION_HOOKS)
674 if (options.session_hooks_allow &&
675 (options.session_hooks_startup_cmd ||
676 options.session_hooks_shutdown_cmd))
684 "/tmp/ssh_env_%d%d%d",
688 } while (stat(env_file, &st)==0);
689 s->authctxt->session_env_file = strdup(env_file);
694 if (options.gss_authentication) {
695 temporarily_use_uid(s->pw);
696 ssh_gssapi_storecreds();
702 do_exec_pty(s, command);
704 do_exec_no_pty(s, command);
706 original_command = NULL;
710 /* administrative, login(1)-like work */
712 do_login(Session *s, const char *command)
716 struct sockaddr_storage from;
717 struct passwd * pw = s->pw;
718 pid_t pid = getpid();
721 * Get IP address of client. If the connection is not a socket, let
722 * the address be 0.0.0.0.
724 memset(&from, 0, sizeof(from));
725 fromlen = sizeof(from);
726 if (packet_connection_is_on_socket()) {
727 if (getpeername(packet_get_connection_in(),
728 (struct sockaddr *) & from, &fromlen) < 0) {
729 debug("getpeername: %.100s", strerror(errno));
734 /* Record that there was a login on that tty from the remote host. */
736 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
737 get_remote_name_or_ip(utmp_len,
739 (struct sockaddr *)&from, fromlen);
743 * If password change is needed, do it now.
744 * This needs to occur before the ~/.hushlogin check.
746 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
749 s->authctxt->force_pwchange = 0;
750 /* XXX - signal [net] parent to enable forwardings */
754 if (check_quietlogin(s, command))
759 #ifndef NO_SSH_LASTLOG
760 if (options.print_lastlog && s->last_login_time != 0) {
761 time_string = ctime(&s->last_login_time);
762 if (strchr(time_string, '\n'))
763 *strchr(time_string, '\n') = 0;
764 if (strcmp(s->hostname, "") == 0)
765 printf("Last login: %s\r\n", time_string);
767 printf("Last login: %s from %s\r\n", time_string,
770 #endif /* NO_SSH_LASTLOG */
776 * Display the message of the day.
784 if (options.print_motd) {
785 #ifdef HAVE_LOGIN_CAP
786 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
789 f = fopen("/etc/motd", "r");
792 while (fgets(buf, sizeof(buf), f))
801 * Check for quiet login, either .hushlogin or command given.
804 check_quietlogin(Session *s, const char *command)
807 struct passwd *pw = s->pw;
810 /* Return 1 if .hushlogin exists or a command given. */
813 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
814 #ifdef HAVE_LOGIN_CAP
815 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
818 if (stat(buf, &st) >= 0)
825 * Sets the value of the given variable in the environment. If the variable
826 * already exists, its value is overriden.
829 child_set_env(char ***envp, u_int *envsizep, const char *name,
837 * If we're passed an uninitialized list, allocate a single null
838 * entry before continuing.
840 if (*envp == NULL && *envsizep == 0) {
841 *envp = xmalloc(sizeof(char *));
847 * Find the slot where the value should be stored. If the variable
848 * already exists, we reuse the slot; otherwise we append a new slot
849 * at the end of the array, expanding if necessary.
852 namelen = strlen(name);
853 for (i = 0; env[i]; i++)
854 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
857 /* Reuse the slot. */
860 /* New variable. Expand if necessary. */
862 if (i >= envsize - 1) {
864 fatal("child_set_env: too many env vars");
866 env = (*envp) = xrealloc(env, envsize * sizeof(char *));
869 /* Need to set the NULL pointer at end of array beyond the new slot. */
873 /* Allocate space and format the variable in the appropriate slot. */
874 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
875 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
879 * Reads environment variables from the given file and adds/overrides them
880 * into the environment. If the file does not exist, this does nothing.
881 * Otherwise, it must consist of empty lines, comments (line starts with '#')
882 * and assignments of the form name=value. No other forms are allowed.
885 read_environment_file(char ***env, u_int *envsize,
886 const char *filename)
893 f = fopen(filename, "r");
897 while (fgets(buf, sizeof(buf), f)) {
899 fatal("Too many lines in environment file %s", filename);
900 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
902 if (!*cp || *cp == '#' || *cp == '\n')
904 if (strchr(cp, '\n'))
905 *strchr(cp, '\n') = '\0';
906 value = strchr(cp, '=');
908 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
913 * Replace the equals sign by nul, and advance value to
918 child_set_env(env, envsize, cp, value);
924 #define SSH_SESSION_ENV_FILE "SSH_SESSION_ENV_FILE"
926 typedef enum { no_op, execute, clear_env, restore_env,
927 read_env, save_or_rm_env } session_action_t;
929 static session_action_t action_order[2][5] = {
930 { clear_env, read_env, execute, save_or_rm_env, restore_env }, /*shutdown*/
931 { execute, read_env, save_or_rm_env, no_op, no_op } /*startup */
935 void execute_session_hook(char* prog, Authctxt *authctxt,
936 int startup, int save)
938 extern char **environ;
941 char **saved_env, **tmpenv;
942 char *env_file = authctxt->session_env_file;
947 switch (action_order[startup][i])
960 authctxt->pw->pw_shell,
963 debug("executing session hook: [%s]", buf);
964 setenv(SSH_SESSION_ENV_FILE, env_file, /* overwrite = */ 1);
966 /* flusing is recommended in the popen(3) man page, to avoid
967 intermingling of output */
970 if ((fp=popen(buf, "w")) == NULL)
972 perror("Unable to run session hook");
976 debug2("session hook executed, status=%d", status);
977 unsetenv(SSH_SESSION_ENV_FILE);
983 tmpenv = (char**) malloc(sizeof(char*));
994 if (status==0 && stat(env_file, &st)==0)
998 debug("reading environment from %s", env_file);
999 while (environ[envsize++]) ;
1000 read_environment_file(&environ, &envsize, env_file);
1004 case save_or_rm_env:
1005 if (status==0 && save)
1010 debug2("saving environment to %s", env_file);
1011 if ((fp = fopen(env_file, "w")) == NULL) /* hmm: file perms? */
1013 perror("Unable to save session hook info");
1015 while (environ[envcount])
1017 fprintf(fp, "%s\n", environ[envcount++]);
1022 else if (stat(env_file, &st)==0)
1024 debug2("removing environment file %s", env_file);
1034 #ifdef HAVE_ETC_DEFAULT_LOGIN
1036 * Return named variable from specified environment, or NULL if not present.
1039 child_get_env(char **env, const char *name)
1045 for (i=0; env[i] != NULL; i++)
1046 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
1047 return(env[i] + len + 1);
1052 * Read /etc/default/login.
1053 * We pick up the PATH (or SUPATH for root) and UMASK.
1056 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
1058 char **tmpenv = NULL, *var;
1059 u_int i, tmpenvsize = 0;
1063 * We don't want to copy the whole file to the child's environment,
1064 * so we use a temporary environment and copy the variables we're
1067 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
1073 var = child_get_env(tmpenv, "SUPATH");
1075 var = child_get_env(tmpenv, "PATH");
1077 child_set_env(env, envsize, "PATH", var);
1079 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
1080 if (sscanf(var, "%5lo", &mask) == 1)
1081 umask((mode_t)mask);
1083 for (i = 0; tmpenv[i] != NULL; i++)
1087 #endif /* HAVE_ETC_DEFAULT_LOGIN */
1089 void copy_environment(char **source, char ***env, u_int *envsize)
1091 char *var_name, *var_val;
1097 for(i = 0; source[i] != NULL; i++) {
1098 var_name = xstrdup(source[i]);
1099 if ((var_val = strstr(var_name, "=")) == NULL) {
1105 debug3("Copy environment: %s=%s", var_name, var_val);
1106 child_set_env(env, envsize, var_name, var_val);
1113 do_setup_env(Session *s, const char *shell)
1117 char **env, *laddr, *path = NULL;
1118 struct passwd *pw = s->pw;
1120 /* Initialize the environment. */
1122 env = xmalloc(envsize * sizeof(char *));
1127 * The Windows environment contains some setting which are
1128 * important for a running system. They must not be dropped.
1130 copy_environment(environ, &env, &envsize);
1134 /* Allow any GSSAPI methods that we've used to alter
1135 * the childs environment as they see fit
1137 ssh_gssapi_do_child(&env, &envsize);
1140 if (!options.use_login) {
1141 /* Set basic environment. */
1142 child_set_env(&env, &envsize, "USER", pw->pw_name);
1143 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1145 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1147 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1148 #ifdef HAVE_LOGIN_CAP
1149 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1150 child_set_env(&env, &envsize, "PATH",
1151 _PATH_STDPATH_WITH_SCP);
1153 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1154 #else /* HAVE_LOGIN_CAP */
1155 # ifndef HAVE_CYGWIN
1157 * There's no standard path on Windows. The path contains
1158 * important components pointing to the system directories,
1159 * needed for loading shared libraries. So the path better
1160 * remains intact here.
1162 if (getenv("LD_LIBRARY_PATH"))
1163 child_set_env(&env, &envsize, "LD_LIBRARY_PATH",
1164 getenv("LD_LIBRARY_PATH"));
1165 # ifdef HAVE_ETC_DEFAULT_LOGIN
1166 read_etc_default_login(&env, &envsize, pw->pw_uid);
1167 path = child_get_env(env, "PATH");
1168 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1169 if (path == NULL || *path == '\0') {
1170 child_set_env(&env, &envsize, "PATH",
1171 s->pw->pw_uid == 0 ?
1172 SUPERUSER_PATH : _PATH_STDPATH_WITH_SCP);
1174 # endif /* HAVE_CYGWIN */
1175 #endif /* HAVE_LOGIN_CAP */
1177 snprintf(buf, sizeof buf, "%.200s/%.50s",
1178 _PATH_MAILDIR, pw->pw_name);
1179 child_set_env(&env, &envsize, "MAIL", buf);
1181 /* Normal systems set SHELL by default. */
1182 child_set_env(&env, &envsize, "SHELL", shell);
1185 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1188 if (getenv("GLOBUS_LOCATION"))
1189 child_set_env(&env, &envsize, "GLOBUS_LOCATION",
1190 getenv("GLOBUS_LOCATION"));
1193 /* Set custom environment options from RSA authentication. */
1194 if (!options.use_login) {
1195 while (custom_environment) {
1196 struct envstring *ce = custom_environment;
1199 for (i = 0; str[i] != '=' && str[i]; i++)
1201 if (str[i] == '=') {
1203 child_set_env(&env, &envsize, str, str + i + 1);
1205 custom_environment = ce->next;
1211 /* SSH_CLIENT deprecated */
1212 snprintf(buf, sizeof buf, "%.50s %d %d",
1213 get_remote_ipaddr(), get_remote_port(), get_local_port());
1214 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1216 laddr = get_local_ipaddr(packet_get_connection_in());
1217 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1218 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1220 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1223 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1225 child_set_env(&env, &envsize, "TERM", s->term);
1227 child_set_env(&env, &envsize, "DISPLAY", s->display);
1228 if (original_command)
1229 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1233 if (cray_tmpdir[0] != '\0')
1234 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1235 #endif /* _UNICOS */
1241 if ((cp = getenv("AUTHSTATE")) != NULL)
1242 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1243 if ((cp = getenv("KRB5CCNAME")) != NULL)
1244 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1245 read_environment_file(&env, &envsize, "/etc/environment");
1249 if (s->authctxt->krb5_ticket_file)
1250 child_set_env(&env, &envsize, "KRB5CCNAME",
1251 s->authctxt->krb5_ticket_file);
1255 * Pull in any environment variables that may have
1258 if (options.use_pam) {
1261 p = fetch_pam_child_environment();
1262 copy_environment(p, &env, &envsize);
1263 free_pam_environment(p);
1265 p = fetch_pam_environment();
1266 copy_environment(p, &env, &envsize);
1267 free_pam_environment(p);
1269 #endif /* USE_PAM */
1271 if (auth_sock_name != NULL)
1272 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1275 /* read $HOME/.ssh/environment. */
1276 if (options.permit_user_env && !options.use_login) {
1277 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1278 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1279 read_environment_file(&env, &envsize, buf);
1282 /* dump the environment */
1283 fprintf(stderr, "Environment:\n");
1284 for (i = 0; env[i]; i++)
1285 fprintf(stderr, " %.200s\n", env[i]);
1291 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1292 * first in this order).
1295 do_rc_files(Session *s, const char *shell)
1303 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1305 /* ignore _PATH_SSH_USER_RC for subsystems */
1306 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1307 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1308 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1310 fprintf(stderr, "Running %s\n", cmd);
1311 f = popen(cmd, "w");
1314 fprintf(f, "%s %s\n", s->auth_proto,
1318 fprintf(stderr, "Could not run %s\n",
1320 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1321 snprintf(cmd, sizeof cmd, "%s %s", _PATH_BSHELL,
1322 _PATH_SSH_SYSTEM_RC);
1324 fprintf(stderr, "Running %s\n", cmd);
1325 f = popen(cmd, "w");
1328 fprintf(f, "%s %s\n", s->auth_proto,
1332 fprintf(stderr, "Could not run %s\n",
1333 _PATH_SSH_SYSTEM_RC);
1334 } else if (do_xauth && options.xauth_location != NULL) {
1335 /* Add authority data to .Xauthority if appropriate. */
1338 "Running %.500s remove %.100s\n",
1339 options.xauth_location, s->auth_display);
1341 "%.500s add %.100s %.100s %.100s\n",
1342 options.xauth_location, s->auth_display,
1343 s->auth_proto, s->auth_data);
1345 snprintf(cmd, sizeof cmd, "%s -q -",
1346 options.xauth_location);
1347 f = popen(cmd, "w");
1349 fprintf(f, "remove %s\n",
1351 fprintf(f, "add %s %s %s\n",
1352 s->auth_display, s->auth_proto,
1356 fprintf(stderr, "Could not run %s\n",
1363 do_nologin(struct passwd *pw)
1368 #ifdef HAVE_LOGIN_CAP
1369 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1370 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1371 _PATH_NOLOGIN), "r");
1374 f = fopen(_PATH_NOLOGIN, "r");
1377 /* /etc/nologin exists. Print its contents and exit. */
1378 logit("User %.100s not allowed because %s exists",
1379 pw->pw_name, _PATH_NOLOGIN);
1380 while (fgets(buf, sizeof(buf), f))
1388 /* Set login name, uid, gid, and groups. */
1390 do_setusercontext(struct passwd *pw)
1393 if (getuid() == 0 || geteuid() == 0)
1394 #endif /* HAVE_CYGWIN */
1397 #ifdef HAVE_SETPCRED
1398 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1399 fatal("Failed to set process credentials");
1400 #endif /* HAVE_SETPCRED */
1401 #ifdef HAVE_LOGIN_CAP
1406 if (options.use_pam) {
1410 # endif /* USE_PAM */
1411 if (setusercontext(lc, pw, pw->pw_uid,
1412 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1413 perror("unable to set user context");
1417 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1418 /* Sets login uid for accounting */
1419 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1420 error("setluid: %s", strerror(errno));
1421 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1423 if (setlogin(pw->pw_name) < 0)
1424 error("setlogin failed: %s", strerror(errno));
1425 if (setgid(pw->pw_gid) < 0) {
1429 /* Initialize the group list. */
1430 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1431 perror("initgroups");
1437 * PAM credentials may take the form of supplementary groups.
1438 * These will have been wiped by the above initgroups() call.
1439 * Reestablish them here.
1441 if (options.use_pam) {
1445 # endif /* USE_PAM */
1446 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1447 irix_setusercontext(pw);
1448 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1452 /* Permanently switch to the desired uid. */
1453 permanently_set_uid(pw);
1460 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1461 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1465 do_pwchange(Session *s)
1467 fprintf(stderr, "WARNING: Your password has expired.\n");
1468 if (s->ttyfd != -1) {
1470 "You must change your password now and login again!\n");
1471 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1475 "Password change required but no TTY available.\n");
1481 launch_login(struct passwd *pw, const char *hostname)
1483 /* Launch login(1). */
1485 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1486 #ifdef xxxLOGIN_NEEDS_TERM
1487 (s->term ? s->term : "unknown"),
1488 #endif /* LOGIN_NEEDS_TERM */
1489 #ifdef LOGIN_NO_ENDOPT
1490 "-p", "-f", pw->pw_name, (char *)NULL);
1492 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1495 /* Login couldn't be executed, die. */
1502 child_close_fds(void)
1506 if (packet_get_connection_in() == packet_get_connection_out())
1507 close(packet_get_connection_in());
1509 close(packet_get_connection_in());
1510 close(packet_get_connection_out());
1513 * Close all descriptors related to channels. They will still remain
1514 * open in the parent.
1516 /* XXX better use close-on-exec? -markus */
1517 channel_close_all();
1520 * Close any extra file descriptors. Note that there may still be
1521 * descriptors left by system functions. They will be closed later.
1526 * Close any extra open file descriptors so that we don\'t have them
1527 * hanging around in clients. Note that we want to do this after
1528 * initgroups, because at least on Solaris 2.3 it leaves file
1531 for (i = 3; i < 64; i++)
1536 * Performs common processing for the child, such as setting up the
1537 * environment, closing extra file descriptors, setting the user and group
1538 * ids, and executing the command or shell.
1541 do_child(Session *s, const char *command)
1543 extern char **environ;
1546 const char *shell, *shell0, *hostname = NULL;
1547 struct passwd *pw = s->pw;
1550 /* Default place to look for aklog. */
1552 #define KPROGDIR AKLOG_PATH
1554 #define KPROGDIR "/usr/bin/aklog"
1555 #endif /* AKLOG_PATH */
1559 #endif /* AFS_KRB5 */
1561 /* remove hostkey from the child's memory */
1562 destroy_sensitive_data();
1564 /* Force a password change */
1565 if (s->authctxt->force_pwchange) {
1566 do_setusercontext(pw);
1572 /* login(1) is only called if we execute the login shell */
1573 if (options.use_login && command != NULL)
1574 options.use_login = 0;
1577 cray_setup(pw->pw_uid, pw->pw_name, command);
1578 #endif /* _UNICOS */
1581 * Login(1) does this as well, and it needs uid 0 for the "-h"
1582 * switch, so we let login(1) to this for us.
1584 if (!options.use_login) {
1586 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1587 if (!check_quietlogin(s, command))
1589 #else /* HAVE_OSF_SIA */
1591 do_setusercontext(pw);
1592 #endif /* HAVE_OSF_SIA */
1596 * Get the shell from the password data. An empty shell field is
1597 * legal, and means /bin/sh.
1599 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1602 * Make sure $SHELL points to the shell from the password file,
1603 * even if shell is overridden from login.conf
1605 env = do_setup_env(s, shell);
1607 #ifdef HAVE_LOGIN_CAP
1608 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1611 /* we have to stash the hostname before we close our socket. */
1612 if (options.use_login)
1613 hostname = get_remote_name_or_ip(utmp_len,
1616 * Close the connection descriptors; note that this is the child, and
1617 * the server will still have the socket open, and it is important
1618 * that we do not shutdown it. Note that the descriptors cannot be
1619 * closed before building the environment, as we call
1620 * get_remote_ipaddr there.
1625 * Must take new environment into use so that .ssh/rc,
1626 * /etc/ssh/sshrc and xauth are run in the proper environment.
1630 #if defined(KRB5) && defined(USE_AFS)
1632 * At this point, we check to see if AFS is active and if we have
1633 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1634 * if we can (and need to) extend the ticket into an AFS token. If
1635 * we don't do this, we run into potential problems if the user's
1636 * home directory is in AFS and it's not world-readable.
1639 if (options.kerberos_get_afs_token && k_hasafs() &&
1640 (s->authctxt->krb5_ctx != NULL)) {
1643 debug("Getting AFS token");
1647 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1648 krb5_afslog(s->authctxt->krb5_ctx,
1649 s->authctxt->krb5_fwd_ccache, cell, NULL);
1651 krb5_afslog_home(s->authctxt->krb5_ctx,
1652 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1658 /* User has authenticated, and if a ticket was going to be
1659 * passed we would have it. KRB5CCNAME should already be set.
1660 * Now try to get an AFS token using aklog.
1662 if (k_hasafs()) { /* Do we have AFS? */
1664 aklog_path = xstrdup(KPROGDIR);
1667 * Make sure it exists before we try to run it
1669 if (stat(aklog_path, &st) == 0) {
1670 debug("Running %s to get afs token.",aklog_path);
1673 debug("%s does not exist.",aklog_path);
1678 #endif /* AFS_KRB5 */
1680 #ifdef SESSION_HOOKS
1681 if (options.session_hooks_allow &&
1682 options.session_hooks_startup_cmd)
1684 execute_session_hook(options.session_hooks_startup_cmd,
1687 options.session_hooks_shutdown_cmd != NULL);
1691 /* Change current directory to the user\'s home directory. */
1692 if (chdir(pw->pw_dir) < 0) {
1693 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1694 pw->pw_dir, strerror(errno));
1695 #ifdef HAVE_LOGIN_CAP
1696 if (login_getcapbool(lc, "requirehome", 0))
1701 if (!options.use_login)
1702 do_rc_files(s, shell);
1704 /* restore SIGPIPE for child */
1705 signal(SIGPIPE, SIG_DFL);
1707 if (options.use_login) {
1708 launch_login(pw, hostname);
1712 /* Get the last component of the shell name. */
1713 if ((shell0 = strrchr(shell, '/')) != NULL)
1719 * If we have no command, execute the shell. In this case, the shell
1720 * name to be passed in argv[0] is preceded by '-' to indicate that
1721 * this is a login shell.
1726 /* Start the shell. Set initial character to '-'. */
1729 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1730 >= sizeof(argv0) - 1) {
1736 /* Execute the shell. */
1739 execve(shell, argv, environ);
1741 /* Executing the shell failed. */
1746 * Execute the command using the user's shell. This uses the -c
1747 * option to execute the command.
1749 argv[0] = (char *) shell0;
1751 argv[2] = (char *) command;
1753 execve(shell, argv, environ);
1762 static int did_init = 0;
1764 debug("session_new: init");
1765 for (i = 0; i < MAX_SESSIONS; i++) {
1766 sessions[i].used = 0;
1770 for (i = 0; i < MAX_SESSIONS; i++) {
1771 Session *s = &sessions[i];
1773 memset(s, 0, sizeof(*s));
1779 debug("session_new: session %d", i);
1790 for (i = 0; i < MAX_SESSIONS; i++) {
1791 Session *s = &sessions[i];
1792 debug("dump: used %d session %d %p channel %d pid %ld",
1802 session_open(Authctxt *authctxt, int chanid)
1804 Session *s = session_new();
1805 debug("session_open: channel %d", chanid);
1807 error("no more sessions");
1810 s->authctxt = authctxt;
1811 s->pw = authctxt->pw;
1812 if (s->pw == NULL || !authctxt->valid)
1813 fatal("no user for session %d", s->self);
1814 debug("session_open: session %d: link with channel %d", s->self, chanid);
1820 session_by_tty(char *tty)
1823 for (i = 0; i < MAX_SESSIONS; i++) {
1824 Session *s = &sessions[i];
1825 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1826 debug("session_by_tty: session %d tty %s", i, tty);
1830 debug("session_by_tty: unknown tty %.100s", tty);
1836 session_by_channel(int id)
1839 for (i = 0; i < MAX_SESSIONS; i++) {
1840 Session *s = &sessions[i];
1841 if (s->used && s->chanid == id) {
1842 debug("session_by_channel: session %d channel %d", i, id);
1846 debug("session_by_channel: unknown channel %d", id);
1852 session_by_pid(pid_t pid)
1855 debug("session_by_pid: pid %ld", (long)pid);
1856 for (i = 0; i < MAX_SESSIONS; i++) {
1857 Session *s = &sessions[i];
1858 if (s->used && s->pid == pid)
1861 error("session_by_pid: unknown pid %ld", (long)pid);
1867 session_window_change_req(Session *s)
1869 s->col = packet_get_int();
1870 s->row = packet_get_int();
1871 s->xpixel = packet_get_int();
1872 s->ypixel = packet_get_int();
1874 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1879 session_pty_req(Session *s)
1885 debug("Allocating a pty not permitted for this authentication.");
1888 if (s->ttyfd != -1) {
1889 packet_disconnect("Protocol error: you already have a pty.");
1892 /* Get the time and hostname when the user last logged in. */
1893 if (options.print_lastlog) {
1894 s->hostname[0] = '\0';
1895 s->last_login_time = get_last_login_time(s->pw->pw_uid,
1896 s->pw->pw_name, s->hostname, sizeof(s->hostname));
1899 s->term = packet_get_string(&len);
1902 s->col = packet_get_int();
1903 s->row = packet_get_int();
1905 s->row = packet_get_int();
1906 s->col = packet_get_int();
1908 s->xpixel = packet_get_int();
1909 s->ypixel = packet_get_int();
1911 if (strcmp(s->term, "") == 0) {
1916 /* Allocate a pty and open it. */
1917 debug("Allocating pty.");
1918 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1924 error("session_pty_req: session %d alloc failed", s->self);
1927 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1929 /* for SSH1 the tty modes length is not given */
1931 n_bytes = packet_remaining();
1932 tty_parse_modes(s->ttyfd, &n_bytes);
1935 pty_setowner(s->pw, s->tty);
1937 /* Set window size from the packet. */
1938 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1941 session_proctitle(s);
1946 session_subsystem_req(Session *s)
1951 char *cmd, *subsys = packet_get_string(&len);
1955 logit("subsystem request for %.100s", subsys);
1957 for (i = 0; i < options.num_subsystems; i++) {
1958 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1959 cmd = options.subsystem_command[i];
1960 if (stat(cmd, &st) < 0) {
1961 error("subsystem: cannot stat %s: %s", cmd,
1965 debug("subsystem: exec() %s", cmd);
1966 s->is_subsystem = 1;
1974 logit("subsystem request for %.100s failed, subsystem not found",
1982 session_x11_req(Session *s)
1986 s->single_connection = packet_get_char();
1987 s->auth_proto = packet_get_string(NULL);
1988 s->auth_data = packet_get_string(NULL);
1989 s->screen = packet_get_int();
1992 success = session_setup_x11fwd(s);
1994 xfree(s->auth_proto);
1995 xfree(s->auth_data);
1996 s->auth_proto = NULL;
1997 s->auth_data = NULL;
2003 session_shell_req(Session *s)
2011 session_exec_req(Session *s)
2014 char *command = packet_get_string(&len);
2016 do_exec(s, command);
2022 session_break_req(Session *s)
2026 break_length = packet_get_int(); /* ignored */
2029 if (s->ttyfd == -1 ||
2030 tcsendbreak(s->ttyfd, 0) < 0)
2036 session_auth_agent_req(Session *s)
2038 static int called = 0;
2040 if (no_agent_forwarding_flag) {
2041 debug("session_auth_agent_req: no_agent_forwarding_flag");
2048 return auth_input_request_forwarding(s->pw);
2053 session_input_channel_req(Channel *c, const char *rtype)
2058 if ((s = session_by_channel(c->self)) == NULL) {
2059 logit("session_input_channel_req: no session %d req %.100s",
2063 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2066 * a session is in LARVAL state until a shell, a command
2067 * or a subsystem is executed
2069 if (c->type == SSH_CHANNEL_LARVAL) {
2070 if (strcmp(rtype, "shell") == 0) {
2071 success = session_shell_req(s);
2072 } else if (strcmp(rtype, "exec") == 0) {
2073 success = session_exec_req(s);
2074 } else if (strcmp(rtype, "pty-req") == 0) {
2075 success = session_pty_req(s);
2076 } else if (strcmp(rtype, "x11-req") == 0) {
2077 success = session_x11_req(s);
2078 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2079 success = session_auth_agent_req(s);
2080 } else if (strcmp(rtype, "subsystem") == 0) {
2081 success = session_subsystem_req(s);
2082 } else if (strcmp(rtype, "break") == 0) {
2083 success = session_break_req(s);
2086 if (strcmp(rtype, "window-change") == 0) {
2087 success = session_window_change_req(s);
2093 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2096 fatal("session_set_fds: called for proto != 2.0");
2098 * now that have a child and a pipe to the child,
2099 * we can activate our channel and register the fd's
2101 if (s->chanid == -1)
2102 fatal("no channel for session %d", s->self);
2103 channel_set_fds(s->chanid,
2105 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2107 CHAN_SES_WINDOW_DEFAULT);
2111 * Function to perform pty cleanup. Also called if we get aborted abnormally
2112 * (e.g., due to a dropped connection).
2115 session_pty_cleanup2(Session *s)
2118 error("session_pty_cleanup: no session");
2124 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2126 /* Record that the user has logged out. */
2128 record_logout(s->pid, s->tty, s->pw->pw_name);
2130 /* Release the pseudo-tty. */
2132 pty_release(s->tty);
2135 * Close the server side of the socket pairs. We must do this after
2136 * the pty cleanup, so that another process doesn't get this pty
2137 * while we're still cleaning up.
2139 if (close(s->ptymaster) < 0)
2140 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2142 /* unlink pty from session */
2147 session_pty_cleanup(Session *s)
2149 PRIVSEP(session_pty_cleanup2(s));
2155 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2170 return "SIG@openssh.com";
2174 session_exit_message(Session *s, int status)
2178 if ((c = channel_lookup(s->chanid)) == NULL)
2179 fatal("session_exit_message: session %d: no channel %d",
2180 s->self, s->chanid);
2181 debug("session_exit_message: session %d channel %d pid %ld",
2182 s->self, s->chanid, (long)s->pid);
2184 if (WIFEXITED(status)) {
2185 channel_request_start(s->chanid, "exit-status", 0);
2186 packet_put_int(WEXITSTATUS(status));
2188 } else if (WIFSIGNALED(status)) {
2189 channel_request_start(s->chanid, "exit-signal", 0);
2190 packet_put_cstring(sig2name(WTERMSIG(status)));
2192 packet_put_char(WCOREDUMP(status));
2193 #else /* WCOREDUMP */
2195 #endif /* WCOREDUMP */
2196 packet_put_cstring("");
2197 packet_put_cstring("");
2200 /* Some weird exit cause. Just exit. */
2201 packet_disconnect("wait returned status %04x.", status);
2204 /* disconnect channel */
2205 debug("session_exit_message: release channel %d", s->chanid);
2206 channel_cancel_cleanup(s->chanid);
2208 * emulate a write failure with 'chan_write_failed', nobody will be
2209 * interested in data we write.
2210 * Note that we must not call 'chan_read_failed', since there could
2211 * be some more data waiting in the pipe.
2213 if (c->ostate != CHAN_OUTPUT_CLOSED)
2214 chan_write_failed(c);
2219 session_close(Session *s)
2221 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2223 session_pty_cleanup(s);
2228 if (s->auth_display)
2229 xfree(s->auth_display);
2231 xfree(s->auth_data);
2233 xfree(s->auth_proto);
2235 session_proctitle(s);
2239 session_close_by_pid(pid_t pid, int status)
2241 Session *s = session_by_pid(pid);
2243 debug("session_close_by_pid: no session for pid %ld",
2247 if (s->chanid != -1)
2248 session_exit_message(s, status);
2253 * this is called when a channel dies before
2254 * the session 'child' itself dies
2257 session_close_by_channel(int id, void *arg)
2259 Session *s = session_by_channel(id);
2261 debug("session_close_by_channel: no session for id %d", id);
2264 debug("session_close_by_channel: channel %d child %ld",
2267 debug("session_close_by_channel: channel %d: has child", id);
2269 * delay detach of session, but release pty, since
2270 * the fd's to the child are already closed
2273 session_pty_cleanup(s);
2276 /* detach by removing callback */
2277 channel_cancel_cleanup(s->chanid);
2283 session_destroy_all(void (*closefunc)(Session *))
2286 for (i = 0; i < MAX_SESSIONS; i++) {
2287 Session *s = &sessions[i];
2289 if (closefunc != NULL)
2298 session_tty_list(void)
2300 static char buf[1024];
2305 for (i = 0; i < MAX_SESSIONS; i++) {
2306 Session *s = &sessions[i];
2307 if (s->used && s->ttyfd != -1) {
2309 if (strncmp(s->tty, "/dev/", 5) != 0) {
2310 cp = strrchr(s->tty, '/');
2311 cp = (cp == NULL) ? s->tty : cp + 1;
2316 strlcat(buf, ",", sizeof buf);
2317 strlcat(buf, cp, sizeof buf);
2321 strlcpy(buf, "notty", sizeof buf);
2326 session_proctitle(Session *s)
2329 error("no user for session %d", s->self);
2331 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2335 session_setup_x11fwd(Session *s)
2338 char display[512], auth_display[512];
2339 char hostname[MAXHOSTNAMELEN];
2341 if (no_x11_forwarding_flag) {
2342 packet_send_debug("X11 forwarding disabled in user configuration file.");
2345 if (!options.x11_forwarding) {
2346 debug("X11 forwarding disabled in server configuration file.");
2349 if (!options.xauth_location ||
2350 (stat(options.xauth_location, &st) == -1)) {
2351 packet_send_debug("No xauth program; cannot forward with spoofing.");
2354 if (options.use_login) {
2355 packet_send_debug("X11 forwarding disabled; "
2356 "not compatible with UseLogin=yes.");
2359 if (s->display != NULL) {
2360 debug("X11 display already set.");
2363 if (x11_create_display_inet(options.x11_display_offset,
2364 options.x11_use_localhost, s->single_connection,
2365 &s->display_number) == -1) {
2366 debug("x11_create_display_inet failed.");
2370 /* Set up a suitable value for the DISPLAY variable. */
2371 if (gethostname(hostname, sizeof(hostname)) < 0)
2372 fatal("gethostname: %.100s", strerror(errno));
2374 * auth_display must be used as the displayname when the
2375 * authorization entry is added with xauth(1). This will be
2376 * different than the DISPLAY string for localhost displays.
2378 if (options.x11_use_localhost) {
2379 snprintf(display, sizeof display, "localhost:%u.%u",
2380 s->display_number, s->screen);
2381 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2382 s->display_number, s->screen);
2383 s->display = xstrdup(display);
2384 s->auth_display = xstrdup(auth_display);
2386 #ifdef IPADDR_IN_DISPLAY
2388 struct in_addr my_addr;
2390 he = gethostbyname(hostname);
2392 error("Can't get IP address for X11 DISPLAY.");
2393 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2396 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2397 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2398 s->display_number, s->screen);
2400 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2401 s->display_number, s->screen);
2403 s->display = xstrdup(display);
2404 s->auth_display = xstrdup(display);
2411 do_authenticated2(Authctxt *authctxt)
2413 server_loop2(authctxt);
2417 do_cleanup(Authctxt *authctxt)
2419 static int called = 0;
2421 debug("do_cleanup");
2423 /* no cleanup if we're in the child for login shell */
2427 /* avoid double cleanup */
2432 if (authctxt == NULL)
2435 if (options.kerberos_ticket_cleanup &&
2437 krb5_cleanup_proc(authctxt);
2441 if (compat20 && options.gss_cleanup_creds)
2442 ssh_gssapi_cleanup_creds();
2446 if (options.use_pam) {
2448 sshpam_thread_cleanup();
2452 /* remove agent socket */
2453 auth_sock_cleanup_proc(authctxt->pw);
2456 * Cleanup ptys/utmp only if privsep is disabled,
2457 * or if running in monitor.
2459 if (!use_privsep || mm_is_monitor())
2460 session_destroy_all(session_pty_cleanup2);