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 1.180 2004/07/28 09:40:29 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", (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 invalid 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 if (s->is_subsystem) {
507 session_set_fds(s, pin[1], pout[0], perr[0]);
509 /* Enter the interactive session. */
510 server_loop(pid, pin[1], pout[0], perr[0]);
511 /* server_loop has closed pin[1], pout[0], and perr[0]. */
513 #else /* USE_PIPES */
514 /* We are the parent. Close the child sides of the socket pairs. */
519 * Clear loginmsg, since it's the child's responsibility to display
520 * it to the user, otherwise multiple sessions may accumulate
521 * multiple copies of the login messages.
523 buffer_clear(&loginmsg);
526 * Enter the interactive session. Note: server_loop must be able to
527 * handle the case that fdin and fdout are the same.
530 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
532 server_loop(pid, inout[1], inout[1], err[1]);
533 /* server_loop has closed inout[1] and err[1]. */
535 #endif /* USE_PIPES */
539 * This is called to fork and execute a command when we have a tty. This
540 * will call do_child from the child, and server_loop from the parent after
541 * setting up file descriptors, controlling tty, updating wtmp, utmp,
542 * lastlog, and other such operations.
545 do_exec_pty(Session *s, const char *command)
547 int fdout, ptyfd, ttyfd, ptymaster;
551 fatal("do_exec_pty: no session");
556 if (options.use_pam) {
557 do_pam_set_tty(s->tty);
563 /* Fork the child. */
564 if ((pid = fork()) == 0) {
567 /* Child. Reinitialize the log because the pid has changed. */
568 log_init(__progname, options.log_level, options.log_facility, log_stderr);
569 /* Close the master side of the pseudo tty. */
572 /* Make the pseudo tty our controlling tty. */
573 pty_make_controlling_tty(&ttyfd, s->tty);
575 /* Redirect stdin/stdout/stderr from the pseudo tty. */
576 if (dup2(ttyfd, 0) < 0)
577 error("dup2 stdin: %s", strerror(errno));
578 if (dup2(ttyfd, 1) < 0)
579 error("dup2 stdout: %s", strerror(errno));
580 if (dup2(ttyfd, 2) < 0)
581 error("dup2 stderr: %s", strerror(errno));
583 /* Close the extra descriptor for the pseudo tty. */
586 /* record login, etc. similar to login(1) */
588 if (!(options.use_login && command == NULL)) {
590 cray_init_job(s->pw); /* set up cray jid and tmpdir */
592 do_login(s, command);
594 # ifdef LOGIN_NEEDS_UTMPX
600 /* Do common processing for the child, such as execing the command. */
601 do_child(s, command);
605 signal(WJSIGNAL, cray_job_termination_handler);
609 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
612 packet_disconnect("fork failed: %.100s", strerror(errno));
615 /* Parent. Close the slave side of the pseudo tty. */
619 * Create another descriptor of the pty master side for use as the
620 * standard input. We could use the original descriptor, but this
621 * simplifies code in server_loop. The descriptor is bidirectional.
625 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
627 /* we keep a reference to the pty master */
628 ptymaster = dup(ptyfd);
630 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
631 s->ptymaster = ptymaster;
633 /* Enter interactive session. */
634 packet_set_interactive(1);
636 session_set_fds(s, ptyfd, fdout, -1);
638 server_loop(pid, ptyfd, fdout, -1);
639 /* server_loop _has_ closed ptyfd and fdout. */
643 #ifdef LOGIN_NEEDS_UTMPX
645 do_pre_login(Session *s)
648 struct sockaddr_storage from;
649 pid_t pid = getpid();
652 * Get IP address of client. If the connection is not a socket, let
653 * the address be 0.0.0.0.
655 memset(&from, 0, sizeof(from));
656 fromlen = sizeof(from);
657 if (packet_connection_is_on_socket()) {
658 if (getpeername(packet_get_connection_in(),
659 (struct sockaddr *) & from, &fromlen) < 0) {
660 debug("getpeername: %.100s", strerror(errno));
665 record_utmp_only(pid, s->tty, s->pw->pw_name,
666 get_remote_name_or_ip(utmp_len, options.use_dns),
667 (struct sockaddr *)&from, fromlen);
672 * This is called to fork and execute a command. If another command is
673 * to be forced, execute that instead.
676 do_exec(Session *s, const char *command)
678 if (forced_command) {
679 original_command = command;
680 command = forced_command;
681 debug("Forced command '%.900s'", command);
684 #if defined(SESSION_HOOKS)
685 if (options.session_hooks_allow &&
686 (options.session_hooks_startup_cmd ||
687 options.session_hooks_shutdown_cmd))
695 "/tmp/ssh_env_%d%d%d",
699 } while (stat(env_file, &st)==0);
700 s->authctxt->session_env_file = strdup(env_file);
705 if (options.gss_authentication) {
706 temporarily_use_uid(s->pw);
707 ssh_gssapi_storecreds();
713 do_exec_pty(s, command);
715 do_exec_no_pty(s, command);
717 original_command = NULL;
720 * Clear loginmsg: it's the child's responsibility to display
721 * it to the user, otherwise multiple sessions may accumulate
722 * multiple copies of the login messages.
724 buffer_clear(&loginmsg);
727 /* administrative, login(1)-like work */
729 do_login(Session *s, const char *command)
732 struct sockaddr_storage from;
733 struct passwd * pw = s->pw;
734 pid_t pid = getpid();
737 * Get IP address of client. If the connection is not a socket, let
738 * the address be 0.0.0.0.
740 memset(&from, 0, sizeof(from));
741 fromlen = sizeof(from);
742 if (packet_connection_is_on_socket()) {
743 if (getpeername(packet_get_connection_in(),
744 (struct sockaddr *) & from, &fromlen) < 0) {
745 debug("getpeername: %.100s", strerror(errno));
750 /* Record that there was a login on that tty from the remote host. */
752 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
753 get_remote_name_or_ip(utmp_len,
755 (struct sockaddr *)&from, fromlen);
759 * If password change is needed, do it now.
760 * This needs to occur before the ~/.hushlogin check.
762 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
765 s->authctxt->force_pwchange = 0;
766 /* XXX - signal [net] parent to enable forwardings */
770 if (check_quietlogin(s, command))
779 * Display the message of the day.
787 if (options.print_motd) {
788 #ifdef HAVE_LOGIN_CAP
789 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
792 f = fopen("/etc/motd", "r");
795 while (fgets(buf, sizeof(buf), f))
804 * Check for quiet login, either .hushlogin or command given.
807 check_quietlogin(Session *s, const char *command)
810 struct passwd *pw = s->pw;
813 /* Return 1 if .hushlogin exists or a command given. */
816 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
817 #ifdef HAVE_LOGIN_CAP
818 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
821 if (stat(buf, &st) >= 0)
828 * Sets the value of the given variable in the environment. If the variable
829 * already exists, its value is overriden.
832 child_set_env(char ***envp, u_int *envsizep, const char *name,
840 * If we're passed an uninitialized list, allocate a single null
841 * entry before continuing.
843 if (*envp == NULL && *envsizep == 0) {
844 *envp = xmalloc(sizeof(char *));
850 * Find the slot where the value should be stored. If the variable
851 * already exists, we reuse the slot; otherwise we append a new slot
852 * at the end of the array, expanding if necessary.
855 namelen = strlen(name);
856 for (i = 0; env[i]; i++)
857 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
860 /* Reuse the slot. */
863 /* New variable. Expand if necessary. */
865 if (i >= envsize - 1) {
867 fatal("child_set_env: too many env vars");
869 env = (*envp) = xrealloc(env, envsize * sizeof(char *));
872 /* Need to set the NULL pointer at end of array beyond the new slot. */
876 /* Allocate space and format the variable in the appropriate slot. */
877 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
878 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
882 * Reads environment variables from the given file and adds/overrides them
883 * into the environment. If the file does not exist, this does nothing.
884 * Otherwise, it must consist of empty lines, comments (line starts with '#')
885 * and assignments of the form name=value. No other forms are allowed.
888 read_environment_file(char ***env, u_int *envsize,
889 const char *filename)
896 f = fopen(filename, "r");
900 while (fgets(buf, sizeof(buf), f)) {
902 fatal("Too many lines in environment file %s", filename);
903 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
905 if (!*cp || *cp == '#' || *cp == '\n')
907 if (strchr(cp, '\n'))
908 *strchr(cp, '\n') = '\0';
909 value = strchr(cp, '=');
911 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
916 * Replace the equals sign by nul, and advance value to
921 child_set_env(env, envsize, cp, value);
927 #define SSH_SESSION_ENV_FILE "SSH_SESSION_ENV_FILE"
929 typedef enum { no_op, execute, clear_env, restore_env,
930 read_env, save_or_rm_env } session_action_t;
932 static session_action_t action_order[2][5] = {
933 { clear_env, read_env, execute, save_or_rm_env, restore_env }, /*shutdown*/
934 { execute, read_env, save_or_rm_env, no_op, no_op } /*startup */
938 void execute_session_hook(char* prog, Authctxt *authctxt,
939 int startup, int save)
941 extern char **environ;
944 char **saved_env, **tmpenv;
945 char *env_file = authctxt->session_env_file;
950 switch (action_order[startup][i])
963 authctxt->pw->pw_shell,
966 debug("executing session hook: [%s]", buf);
967 setenv(SSH_SESSION_ENV_FILE, env_file, /* overwrite = */ 1);
969 /* flusing is recommended in the popen(3) man page, to avoid
970 intermingling of output */
973 if ((fp=popen(buf, "w")) == NULL)
975 perror("Unable to run session hook");
979 debug2("session hook executed, status=%d", status);
980 unsetenv(SSH_SESSION_ENV_FILE);
986 tmpenv = (char**) malloc(sizeof(char*));
997 if (status==0 && stat(env_file, &st)==0)
1001 debug("reading environment from %s", env_file);
1002 while (environ[envsize++]) ;
1003 read_environment_file(&environ, &envsize, env_file);
1007 case save_or_rm_env:
1008 if (status==0 && save)
1013 debug2("saving environment to %s", env_file);
1014 if ((fp = fopen(env_file, "w")) == NULL) /* hmm: file perms? */
1016 perror("Unable to save session hook info");
1018 while (environ[envcount])
1020 fprintf(fp, "%s\n", environ[envcount++]);
1025 else if (stat(env_file, &st)==0)
1027 debug2("removing environment file %s", env_file);
1037 #ifdef HAVE_ETC_DEFAULT_LOGIN
1039 * Return named variable from specified environment, or NULL if not present.
1042 child_get_env(char **env, const char *name)
1048 for (i=0; env[i] != NULL; i++)
1049 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
1050 return(env[i] + len + 1);
1055 * Read /etc/default/login.
1056 * We pick up the PATH (or SUPATH for root) and UMASK.
1059 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
1061 char **tmpenv = NULL, *var;
1062 u_int i, tmpenvsize = 0;
1066 * We don't want to copy the whole file to the child's environment,
1067 * so we use a temporary environment and copy the variables we're
1070 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
1076 var = child_get_env(tmpenv, "SUPATH");
1078 var = child_get_env(tmpenv, "PATH");
1080 child_set_env(env, envsize, "PATH", var);
1082 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
1083 if (sscanf(var, "%5lo", &mask) == 1)
1084 umask((mode_t)mask);
1086 for (i = 0; tmpenv[i] != NULL; i++)
1090 #endif /* HAVE_ETC_DEFAULT_LOGIN */
1092 void copy_environment(char **source, char ***env, u_int *envsize)
1094 char *var_name, *var_val;
1100 for(i = 0; source[i] != NULL; i++) {
1101 var_name = xstrdup(source[i]);
1102 if ((var_val = strstr(var_name, "=")) == NULL) {
1108 debug3("Copy environment: %s=%s", var_name, var_val);
1109 child_set_env(env, envsize, var_name, var_val);
1116 do_setup_env(Session *s, const char *shell)
1120 char **env, *laddr, *path = NULL;
1121 struct passwd *pw = s->pw;
1123 /* Initialize the environment. */
1125 env = xmalloc(envsize * sizeof(char *));
1130 * The Windows environment contains some setting which are
1131 * important for a running system. They must not be dropped.
1133 copy_environment(environ, &env, &envsize);
1137 /* Allow any GSSAPI methods that we've used to alter
1138 * the childs environment as they see fit
1140 ssh_gssapi_do_child(&env, &envsize);
1143 if (!options.use_login) {
1144 /* Set basic environment. */
1145 for (i = 0; i < s->num_env; i++)
1146 child_set_env(&env, &envsize, s->env[i].name,
1149 child_set_env(&env, &envsize, "USER", pw->pw_name);
1150 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1152 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1154 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1155 #ifdef HAVE_LOGIN_CAP
1156 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1157 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1159 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1160 #else /* HAVE_LOGIN_CAP */
1161 # ifndef HAVE_CYGWIN
1163 * There's no standard path on Windows. The path contains
1164 * important components pointing to the system directories,
1165 * needed for loading shared libraries. So the path better
1166 * remains intact here.
1168 # ifdef HAVE_ETC_DEFAULT_LOGIN
1169 read_etc_default_login(&env, &envsize, pw->pw_uid);
1170 path = child_get_env(env, "PATH");
1171 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1172 if (path == NULL || *path == '\0') {
1173 child_set_env(&env, &envsize, "PATH",
1174 s->pw->pw_uid == 0 ?
1175 SUPERUSER_PATH : _PATH_STDPATH);
1177 # endif /* HAVE_CYGWIN */
1178 #endif /* HAVE_LOGIN_CAP */
1180 snprintf(buf, sizeof buf, "%.200s/%.50s",
1181 _PATH_MAILDIR, pw->pw_name);
1182 child_set_env(&env, &envsize, "MAIL", buf);
1184 /* Normal systems set SHELL by default. */
1185 child_set_env(&env, &envsize, "SHELL", shell);
1188 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1190 #ifdef GSI /* GSI shared libs typically installed in non-system locations. */
1194 if ((cp = getenv("LD_LIBRARY_PATH")) != NULL)
1195 child_set_env(&env, &envsize, "LD_LIBRARY_PATH", cp);
1196 if ((cp = getenv("LIBPATH")) != NULL)
1197 child_set_env(&env, &envsize, "LIBPATH", cp);
1198 if ((cp = getenv("SHLIB_PATH")) != NULL)
1199 child_set_env(&env, &envsize, "SHLIB_PATH", cp);
1200 if ((cp = getenv("LD_LIBRARYN32_PATH")) != NULL)
1201 child_set_env(&env, &envsize, "LD_LIBRARYN32_PATH",cp);
1202 if ((cp = getenv("LD_LIBRARY64_PATH")) != NULL)
1203 child_set_env(&env, &envsize, "LD_LIBRARY64_PATH",cp);
1207 /* Set custom environment options from RSA authentication. */
1208 if (!options.use_login) {
1209 while (custom_environment) {
1210 struct envstring *ce = custom_environment;
1213 for (i = 0; str[i] != '=' && str[i]; i++)
1215 if (str[i] == '=') {
1217 child_set_env(&env, &envsize, str, str + i + 1);
1219 custom_environment = ce->next;
1225 /* SSH_CLIENT deprecated */
1226 snprintf(buf, sizeof buf, "%.50s %d %d",
1227 get_remote_ipaddr(), get_remote_port(), get_local_port());
1228 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1230 laddr = get_local_ipaddr(packet_get_connection_in());
1231 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1232 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1234 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1237 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1239 child_set_env(&env, &envsize, "TERM", s->term);
1241 child_set_env(&env, &envsize, "DISPLAY", s->display);
1242 if (original_command)
1243 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1247 if (cray_tmpdir[0] != '\0')
1248 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1249 #endif /* _UNICOS */
1255 if ((cp = getenv("AUTHSTATE")) != NULL)
1256 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1257 if ((cp = getenv("KRB5CCNAME")) != NULL)
1258 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1259 read_environment_file(&env, &envsize, "/etc/environment");
1263 if (s->authctxt->krb5_ccname)
1264 child_set_env(&env, &envsize, "KRB5CCNAME",
1265 s->authctxt->krb5_ccname);
1269 * Pull in any environment variables that may have
1272 if (options.use_pam) {
1275 p = fetch_pam_child_environment();
1276 copy_environment(p, &env, &envsize);
1277 free_pam_environment(p);
1279 p = fetch_pam_environment();
1280 copy_environment(p, &env, &envsize);
1281 free_pam_environment(p);
1283 #endif /* USE_PAM */
1285 if (auth_sock_name != NULL)
1286 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1289 /* read $HOME/.ssh/environment. */
1290 if (options.permit_user_env && !options.use_login) {
1291 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1292 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1293 read_environment_file(&env, &envsize, buf);
1296 /* dump the environment */
1297 fprintf(stderr, "Environment:\n");
1298 for (i = 0; env[i]; i++)
1299 fprintf(stderr, " %.200s\n", env[i]);
1305 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1306 * first in this order).
1309 do_rc_files(Session *s, const char *shell)
1317 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1319 /* ignore _PATH_SSH_USER_RC for subsystems */
1320 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1321 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1322 shell, _PATH_BSHELL, _PATH_SSH_USER_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",
1334 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1336 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1337 _PATH_SSH_SYSTEM_RC);
1338 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1341 fprintf(f, "%s %s\n", s->auth_proto,
1345 fprintf(stderr, "Could not run %s\n",
1346 _PATH_SSH_SYSTEM_RC);
1347 } else if (do_xauth && options.xauth_location != NULL) {
1348 /* Add authority data to .Xauthority if appropriate. */
1351 "Running %.500s remove %.100s\n",
1352 options.xauth_location, s->auth_display);
1354 "%.500s add %.100s %.100s %.100s\n",
1355 options.xauth_location, s->auth_display,
1356 s->auth_proto, s->auth_data);
1358 snprintf(cmd, sizeof cmd, "%s -q -",
1359 options.xauth_location);
1360 f = popen(cmd, "w");
1362 fprintf(f, "remove %s\n",
1364 fprintf(f, "add %s %s %s\n",
1365 s->auth_display, s->auth_proto,
1369 fprintf(stderr, "Could not run %s\n",
1376 do_nologin(struct passwd *pw)
1381 #ifdef HAVE_LOGIN_CAP
1382 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1383 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1384 _PATH_NOLOGIN), "r");
1387 f = fopen(_PATH_NOLOGIN, "r");
1390 /* /etc/nologin exists. Print its contents and exit. */
1391 logit("User %.100s not allowed because %s exists",
1392 pw->pw_name, _PATH_NOLOGIN);
1393 while (fgets(buf, sizeof(buf), f))
1401 /* Set login name, uid, gid, and groups. */
1403 do_setusercontext(struct passwd *pw)
1406 if (getuid() == 0 || geteuid() == 0)
1407 #endif /* HAVE_CYGWIN */
1410 #ifdef HAVE_SETPCRED
1411 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1412 fatal("Failed to set process credentials");
1413 #endif /* HAVE_SETPCRED */
1414 #ifdef HAVE_LOGIN_CAP
1419 if (options.use_pam) {
1423 # endif /* USE_PAM */
1424 if (setusercontext(lc, pw, pw->pw_uid,
1425 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1426 perror("unable to set user context");
1430 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1431 /* Sets login uid for accounting */
1432 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1433 error("setluid: %s", strerror(errno));
1434 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1436 if (setlogin(pw->pw_name) < 0)
1437 error("setlogin failed: %s", strerror(errno));
1438 if (setgid(pw->pw_gid) < 0) {
1442 /* Initialize the group list. */
1443 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1444 perror("initgroups");
1450 * PAM credentials may take the form of supplementary groups.
1451 * These will have been wiped by the above initgroups() call.
1452 * Reestablish them here.
1454 if (options.use_pam) {
1458 # endif /* USE_PAM */
1459 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1460 irix_setusercontext(pw);
1461 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1465 /* Permanently switch to the desired uid. */
1466 permanently_set_uid(pw);
1473 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1474 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1478 do_pwchange(Session *s)
1481 fprintf(stderr, "WARNING: Your password has expired.\n");
1482 if (s->ttyfd != -1) {
1484 "You must change your password now and login again!\n");
1485 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1489 "Password change required but no TTY available.\n");
1495 launch_login(struct passwd *pw, const char *hostname)
1497 /* Launch login(1). */
1499 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1500 #ifdef xxxLOGIN_NEEDS_TERM
1501 (s->term ? s->term : "unknown"),
1502 #endif /* LOGIN_NEEDS_TERM */
1503 #ifdef LOGIN_NO_ENDOPT
1504 "-p", "-f", pw->pw_name, (char *)NULL);
1506 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1509 /* Login couldn't be executed, die. */
1516 child_close_fds(void)
1520 if (packet_get_connection_in() == packet_get_connection_out())
1521 close(packet_get_connection_in());
1523 close(packet_get_connection_in());
1524 close(packet_get_connection_out());
1527 * Close all descriptors related to channels. They will still remain
1528 * open in the parent.
1530 /* XXX better use close-on-exec? -markus */
1531 channel_close_all();
1534 * Close any extra file descriptors. Note that there may still be
1535 * descriptors left by system functions. They will be closed later.
1540 * Close any extra open file descriptors so that we don\'t have them
1541 * hanging around in clients. Note that we want to do this after
1542 * initgroups, because at least on Solaris 2.3 it leaves file
1545 for (i = 3; i < 64; i++)
1550 * Performs common processing for the child, such as setting up the
1551 * environment, closing extra file descriptors, setting the user and group
1552 * ids, and executing the command or shell.
1555 do_child(Session *s, const char *command)
1557 extern char **environ;
1560 const char *shell, *shell0, *hostname = NULL;
1561 struct passwd *pw = s->pw;
1564 /* Default place to look for aklog. */
1566 #define KPROGDIR AKLOG_PATH
1568 #define KPROGDIR "/usr/bin/aklog"
1569 #endif /* AKLOG_PATH */
1573 #endif /* AFS_KRB5 */
1575 /* remove hostkey from the child's memory */
1576 destroy_sensitive_data();
1578 /* Force a password change */
1579 if (s->authctxt->force_pwchange) {
1580 do_setusercontext(pw);
1586 /* login(1) is only called if we execute the login shell */
1587 if (options.use_login && command != NULL)
1588 options.use_login = 0;
1591 cray_setup(pw->pw_uid, pw->pw_name, command);
1592 #endif /* _UNICOS */
1595 * Login(1) does this as well, and it needs uid 0 for the "-h"
1596 * switch, so we let login(1) to this for us.
1598 if (!options.use_login) {
1600 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1601 if (!check_quietlogin(s, command))
1603 #else /* HAVE_OSF_SIA */
1605 do_setusercontext(pw);
1607 * PAM session modules in do_setusercontext may have
1608 * generated messages, so if this in an interactive
1609 * login then display them too.
1611 if (command == NULL)
1613 #endif /* HAVE_OSF_SIA */
1617 * Get the shell from the password data. An empty shell field is
1618 * legal, and means /bin/sh.
1620 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1623 * Make sure $SHELL points to the shell from the password file,
1624 * even if shell is overridden from login.conf
1626 env = do_setup_env(s, shell);
1628 #ifdef HAVE_LOGIN_CAP
1629 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1632 /* we have to stash the hostname before we close our socket. */
1633 if (options.use_login)
1634 hostname = get_remote_name_or_ip(utmp_len,
1637 * Close the connection descriptors; note that this is the child, and
1638 * the server will still have the socket open, and it is important
1639 * that we do not shutdown it. Note that the descriptors cannot be
1640 * closed before building the environment, as we call
1641 * get_remote_ipaddr there.
1646 * Must take new environment into use so that .ssh/rc,
1647 * /etc/ssh/sshrc and xauth are run in the proper environment.
1651 #if defined(KRB5) && defined(USE_AFS)
1653 * At this point, we check to see if AFS is active and if we have
1654 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1655 * if we can (and need to) extend the ticket into an AFS token. If
1656 * we don't do this, we run into potential problems if the user's
1657 * home directory is in AFS and it's not world-readable.
1660 if (options.kerberos_get_afs_token && k_hasafs() &&
1661 (s->authctxt->krb5_ctx != NULL)) {
1664 debug("Getting AFS token");
1668 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1669 krb5_afslog(s->authctxt->krb5_ctx,
1670 s->authctxt->krb5_fwd_ccache, cell, NULL);
1672 krb5_afslog_home(s->authctxt->krb5_ctx,
1673 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1679 /* User has authenticated, and if a ticket was going to be
1680 * passed we would have it. KRB5CCNAME should already be set.
1681 * Now try to get an AFS token using aklog.
1683 if (k_hasafs()) { /* Do we have AFS? */
1685 aklog_path = xstrdup(KPROGDIR);
1688 * Make sure it exists before we try to run it
1690 if (stat(aklog_path, &st) == 0) {
1691 debug("Running %s to get afs token.",aklog_path);
1694 debug("%s does not exist.",aklog_path);
1699 #endif /* AFS_KRB5 */
1701 #ifdef SESSION_HOOKS
1702 if (options.session_hooks_allow &&
1703 options.session_hooks_startup_cmd)
1705 execute_session_hook(options.session_hooks_startup_cmd,
1708 options.session_hooks_shutdown_cmd != NULL);
1712 /* Change current directory to the user\'s home directory. */
1713 if (chdir(pw->pw_dir) < 0) {
1714 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1715 pw->pw_dir, strerror(errno));
1716 #ifdef HAVE_LOGIN_CAP
1717 if (login_getcapbool(lc, "requirehome", 0))
1722 if (!options.use_login)
1723 do_rc_files(s, shell);
1725 /* restore SIGPIPE for child */
1726 signal(SIGPIPE, SIG_DFL);
1728 if (options.use_login) {
1729 launch_login(pw, hostname);
1733 /* Get the last component of the shell name. */
1734 if ((shell0 = strrchr(shell, '/')) != NULL)
1740 * If we have no command, execute the shell. In this case, the shell
1741 * name to be passed in argv[0] is preceded by '-' to indicate that
1742 * this is a login shell.
1747 /* Start the shell. Set initial character to '-'. */
1750 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1751 >= sizeof(argv0) - 1) {
1757 /* Execute the shell. */
1760 execve(shell, argv, environ);
1762 /* Executing the shell failed. */
1767 * Execute the command using the user's shell. This uses the -c
1768 * option to execute the command.
1770 argv[0] = (char *) shell0;
1772 argv[2] = (char *) command;
1774 execve(shell, argv, environ);
1783 static int did_init = 0;
1785 debug("session_new: init");
1786 for (i = 0; i < MAX_SESSIONS; i++) {
1787 sessions[i].used = 0;
1791 for (i = 0; i < MAX_SESSIONS; i++) {
1792 Session *s = &sessions[i];
1794 memset(s, 0, sizeof(*s));
1800 debug("session_new: session %d", i);
1811 for (i = 0; i < MAX_SESSIONS; i++) {
1812 Session *s = &sessions[i];
1813 debug("dump: used %d session %d %p channel %d pid %ld",
1823 session_open(Authctxt *authctxt, int chanid)
1825 Session *s = session_new();
1826 debug("session_open: channel %d", chanid);
1828 error("no more sessions");
1831 s->authctxt = authctxt;
1832 s->pw = authctxt->pw;
1833 if (s->pw == NULL || !authctxt->valid)
1834 fatal("no user for session %d", s->self);
1835 debug("session_open: session %d: link with channel %d", s->self, chanid);
1841 session_by_tty(char *tty)
1844 for (i = 0; i < MAX_SESSIONS; i++) {
1845 Session *s = &sessions[i];
1846 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1847 debug("session_by_tty: session %d tty %s", i, tty);
1851 debug("session_by_tty: unknown tty %.100s", tty);
1857 session_by_channel(int id)
1860 for (i = 0; i < MAX_SESSIONS; i++) {
1861 Session *s = &sessions[i];
1862 if (s->used && s->chanid == id) {
1863 debug("session_by_channel: session %d channel %d", i, id);
1867 debug("session_by_channel: unknown channel %d", id);
1873 session_by_pid(pid_t pid)
1876 debug("session_by_pid: pid %ld", (long)pid);
1877 for (i = 0; i < MAX_SESSIONS; i++) {
1878 Session *s = &sessions[i];
1879 if (s->used && s->pid == pid)
1882 error("session_by_pid: unknown pid %ld", (long)pid);
1888 session_window_change_req(Session *s)
1890 s->col = packet_get_int();
1891 s->row = packet_get_int();
1892 s->xpixel = packet_get_int();
1893 s->ypixel = packet_get_int();
1895 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1900 session_pty_req(Session *s)
1906 debug("Allocating a pty not permitted for this authentication.");
1909 if (s->ttyfd != -1) {
1910 packet_disconnect("Protocol error: you already have a pty.");
1914 s->term = packet_get_string(&len);
1917 s->col = packet_get_int();
1918 s->row = packet_get_int();
1920 s->row = packet_get_int();
1921 s->col = packet_get_int();
1923 s->xpixel = packet_get_int();
1924 s->ypixel = packet_get_int();
1926 if (strcmp(s->term, "") == 0) {
1931 /* Allocate a pty and open it. */
1932 debug("Allocating pty.");
1933 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1939 error("session_pty_req: session %d alloc failed", s->self);
1942 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1944 /* for SSH1 the tty modes length is not given */
1946 n_bytes = packet_remaining();
1947 tty_parse_modes(s->ttyfd, &n_bytes);
1950 pty_setowner(s->pw, s->tty);
1952 /* Set window size from the packet. */
1953 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1956 session_proctitle(s);
1961 session_subsystem_req(Session *s)
1966 char *cmd, *subsys = packet_get_string(&len);
1970 logit("subsystem request for %.100s", subsys);
1972 for (i = 0; i < options.num_subsystems; i++) {
1973 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1974 cmd = options.subsystem_command[i];
1975 if (stat(cmd, &st) < 0) {
1976 error("subsystem: cannot stat %s: %s", cmd,
1980 debug("subsystem: exec() %s", cmd);
1981 s->is_subsystem = 1;
1989 logit("subsystem request for %.100s failed, subsystem not found",
1997 session_x11_req(Session *s)
2001 s->single_connection = packet_get_char();
2002 s->auth_proto = packet_get_string(NULL);
2003 s->auth_data = packet_get_string(NULL);
2004 s->screen = packet_get_int();
2007 success = session_setup_x11fwd(s);
2009 xfree(s->auth_proto);
2010 xfree(s->auth_data);
2011 s->auth_proto = NULL;
2012 s->auth_data = NULL;
2018 session_shell_req(Session *s)
2026 session_exec_req(Session *s)
2029 char *command = packet_get_string(&len);
2031 do_exec(s, command);
2037 session_break_req(Session *s)
2040 packet_get_int(); /* ignored */
2043 if (s->ttyfd == -1 ||
2044 tcsendbreak(s->ttyfd, 0) < 0)
2050 session_env_req(Session *s)
2053 u_int name_len, val_len, i;
2055 name = packet_get_string(&name_len);
2056 val = packet_get_string(&val_len);
2059 /* Don't set too many environment variables */
2060 if (s->num_env > 128) {
2061 debug2("Ignoring env request %s: too many env vars", name);
2065 for (i = 0; i < options.num_accept_env; i++) {
2066 if (match_pattern(name, options.accept_env[i])) {
2067 debug2("Setting env %d: %s=%s", s->num_env, name, val);
2068 s->env = xrealloc(s->env, sizeof(*s->env) *
2070 s->env[s->num_env].name = name;
2071 s->env[s->num_env].val = val;
2076 debug2("Ignoring env request %s: disallowed name", name);
2085 session_auth_agent_req(Session *s)
2087 static int called = 0;
2089 if (no_agent_forwarding_flag) {
2090 debug("session_auth_agent_req: no_agent_forwarding_flag");
2097 return auth_input_request_forwarding(s->pw);
2102 session_input_channel_req(Channel *c, const char *rtype)
2107 if ((s = session_by_channel(c->self)) == NULL) {
2108 logit("session_input_channel_req: no session %d req %.100s",
2112 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2115 * a session is in LARVAL state until a shell, a command
2116 * or a subsystem is executed
2118 if (c->type == SSH_CHANNEL_LARVAL) {
2119 if (strcmp(rtype, "shell") == 0) {
2120 success = session_shell_req(s);
2121 } else if (strcmp(rtype, "exec") == 0) {
2122 success = session_exec_req(s);
2123 } else if (strcmp(rtype, "pty-req") == 0) {
2124 success = session_pty_req(s);
2125 } else if (strcmp(rtype, "x11-req") == 0) {
2126 success = session_x11_req(s);
2127 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2128 success = session_auth_agent_req(s);
2129 } else if (strcmp(rtype, "subsystem") == 0) {
2130 success = session_subsystem_req(s);
2131 } else if (strcmp(rtype, "env") == 0) {
2132 success = session_env_req(s);
2135 if (strcmp(rtype, "window-change") == 0) {
2136 success = session_window_change_req(s);
2137 } else if (strcmp(rtype, "break") == 0) {
2138 success = session_break_req(s);
2145 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2148 fatal("session_set_fds: called for proto != 2.0");
2150 * now that have a child and a pipe to the child,
2151 * we can activate our channel and register the fd's
2153 if (s->chanid == -1)
2154 fatal("no channel for session %d", s->self);
2155 channel_set_fds(s->chanid,
2157 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2159 CHAN_SES_WINDOW_DEFAULT);
2163 * Function to perform pty cleanup. Also called if we get aborted abnormally
2164 * (e.g., due to a dropped connection).
2167 session_pty_cleanup2(Session *s)
2170 error("session_pty_cleanup: no session");
2176 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2178 /* Record that the user has logged out. */
2180 record_logout(s->pid, s->tty, s->pw->pw_name);
2182 /* Release the pseudo-tty. */
2184 pty_release(s->tty);
2187 * Close the server side of the socket pairs. We must do this after
2188 * the pty cleanup, so that another process doesn't get this pty
2189 * while we're still cleaning up.
2191 if (close(s->ptymaster) < 0)
2192 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2194 /* unlink pty from session */
2199 session_pty_cleanup(Session *s)
2201 PRIVSEP(session_pty_cleanup2(s));
2207 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2222 return "SIG@openssh.com";
2226 session_exit_message(Session *s, int status)
2230 if ((c = channel_lookup(s->chanid)) == NULL)
2231 fatal("session_exit_message: session %d: no channel %d",
2232 s->self, s->chanid);
2233 debug("session_exit_message: session %d channel %d pid %ld",
2234 s->self, s->chanid, (long)s->pid);
2236 if (WIFEXITED(status)) {
2237 channel_request_start(s->chanid, "exit-status", 0);
2238 packet_put_int(WEXITSTATUS(status));
2240 } else if (WIFSIGNALED(status)) {
2241 channel_request_start(s->chanid, "exit-signal", 0);
2242 packet_put_cstring(sig2name(WTERMSIG(status)));
2244 packet_put_char(WCOREDUMP(status));
2245 #else /* WCOREDUMP */
2247 #endif /* WCOREDUMP */
2248 packet_put_cstring("");
2249 packet_put_cstring("");
2252 /* Some weird exit cause. Just exit. */
2253 packet_disconnect("wait returned status %04x.", status);
2256 /* disconnect channel */
2257 debug("session_exit_message: release channel %d", s->chanid);
2258 channel_cancel_cleanup(s->chanid);
2260 * emulate a write failure with 'chan_write_failed', nobody will be
2261 * interested in data we write.
2262 * Note that we must not call 'chan_read_failed', since there could
2263 * be some more data waiting in the pipe.
2265 if (c->ostate != CHAN_OUTPUT_CLOSED)
2266 chan_write_failed(c);
2271 session_close(Session *s)
2275 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2277 session_pty_cleanup(s);
2282 if (s->auth_display)
2283 xfree(s->auth_display);
2285 xfree(s->auth_data);
2287 xfree(s->auth_proto);
2289 for (i = 0; i < s->num_env; i++) {
2290 xfree(s->env[i].name);
2291 xfree(s->env[i].val);
2295 session_proctitle(s);
2299 session_close_by_pid(pid_t pid, int status)
2301 Session *s = session_by_pid(pid);
2303 debug("session_close_by_pid: no session for pid %ld",
2307 if (s->chanid != -1)
2308 session_exit_message(s, status);
2313 * this is called when a channel dies before
2314 * the session 'child' itself dies
2317 session_close_by_channel(int id, void *arg)
2319 Session *s = session_by_channel(id);
2321 debug("session_close_by_channel: no session for id %d", id);
2324 debug("session_close_by_channel: channel %d child %ld",
2327 debug("session_close_by_channel: channel %d: has child", id);
2329 * delay detach of session, but release pty, since
2330 * the fd's to the child are already closed
2333 session_pty_cleanup(s);
2336 /* detach by removing callback */
2337 channel_cancel_cleanup(s->chanid);
2343 session_destroy_all(void (*closefunc)(Session *))
2346 for (i = 0; i < MAX_SESSIONS; i++) {
2347 Session *s = &sessions[i];
2349 if (closefunc != NULL)
2358 session_tty_list(void)
2360 static char buf[1024];
2365 for (i = 0; i < MAX_SESSIONS; i++) {
2366 Session *s = &sessions[i];
2367 if (s->used && s->ttyfd != -1) {
2369 if (strncmp(s->tty, "/dev/", 5) != 0) {
2370 cp = strrchr(s->tty, '/');
2371 cp = (cp == NULL) ? s->tty : cp + 1;
2376 strlcat(buf, ",", sizeof buf);
2377 strlcat(buf, cp, sizeof buf);
2381 strlcpy(buf, "notty", sizeof buf);
2386 session_proctitle(Session *s)
2389 error("no user for session %d", s->self);
2391 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2395 session_setup_x11fwd(Session *s)
2398 char display[512], auth_display[512];
2399 char hostname[MAXHOSTNAMELEN];
2401 if (no_x11_forwarding_flag) {
2402 packet_send_debug("X11 forwarding disabled in user configuration file.");
2405 if (!options.x11_forwarding) {
2406 debug("X11 forwarding disabled in server configuration file.");
2409 if (!options.xauth_location ||
2410 (stat(options.xauth_location, &st) == -1)) {
2411 packet_send_debug("No xauth program; cannot forward with spoofing.");
2414 if (options.use_login) {
2415 packet_send_debug("X11 forwarding disabled; "
2416 "not compatible with UseLogin=yes.");
2419 if (s->display != NULL) {
2420 debug("X11 display already set.");
2423 if (x11_create_display_inet(options.x11_display_offset,
2424 options.x11_use_localhost, s->single_connection,
2425 &s->display_number) == -1) {
2426 debug("x11_create_display_inet failed.");
2430 /* Set up a suitable value for the DISPLAY variable. */
2431 if (gethostname(hostname, sizeof(hostname)) < 0)
2432 fatal("gethostname: %.100s", strerror(errno));
2434 * auth_display must be used as the displayname when the
2435 * authorization entry is added with xauth(1). This will be
2436 * different than the DISPLAY string for localhost displays.
2438 if (options.x11_use_localhost) {
2439 snprintf(display, sizeof display, "localhost:%u.%u",
2440 s->display_number, s->screen);
2441 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2442 s->display_number, s->screen);
2443 s->display = xstrdup(display);
2444 s->auth_display = xstrdup(auth_display);
2446 #ifdef IPADDR_IN_DISPLAY
2448 struct in_addr my_addr;
2450 he = gethostbyname(hostname);
2452 error("Can't get IP address for X11 DISPLAY.");
2453 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2456 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2457 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2458 s->display_number, s->screen);
2460 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2461 s->display_number, s->screen);
2463 s->display = xstrdup(display);
2464 s->auth_display = xstrdup(display);
2471 do_authenticated2(Authctxt *authctxt)
2473 server_loop2(authctxt);
2477 do_cleanup(Authctxt *authctxt)
2479 static int called = 0;
2481 debug("do_cleanup");
2483 /* no cleanup if we're in the child for login shell */
2487 /* avoid double cleanup */
2492 if (authctxt == NULL)
2495 if (options.kerberos_ticket_cleanup &&
2497 krb5_cleanup_proc(authctxt);
2501 if (compat20 && options.gss_cleanup_creds)
2502 ssh_gssapi_cleanup_creds();
2506 if (options.use_pam) {
2508 sshpam_thread_cleanup();
2512 /* remove agent socket */
2513 auth_sock_cleanup_proc(authctxt->pw);
2516 * Cleanup ptys/utmp only if privsep is disabled,
2517 * or if running in monitor.
2519 if (!use_privsep || mm_is_monitor())
2520 session_destroy_all(session_pty_cleanup2);