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 1.186 2005/07/25 11:59:40 markus Exp $");
51 #include "auth-options.h"
52 #include "pathnames.h"
56 #include "serverloop.h"
60 #include "monitor_wrap.h"
62 #if defined(KRB5) && defined(USE_AFS)
72 Session *session_new(void);
73 void session_set_fds(Session *, int, int, int);
74 void session_pty_cleanup(Session *);
75 void session_proctitle(Session *);
76 int session_setup_x11fwd(Session *);
77 void do_exec_pty(Session *, const char *);
78 void do_exec_no_pty(Session *, const char *);
79 void do_exec(Session *, const char *);
80 void do_login(Session *, const char *);
81 #ifdef LOGIN_NEEDS_UTMPX
82 static void do_pre_login(Session *s);
84 void do_child(Session *, const char *);
86 int check_quietlogin(Session *, const char *);
88 static void do_authenticated1(Authctxt *);
89 static void do_authenticated2(Authctxt *);
91 static int session_pty_req(Session *);
94 static void execute_session_hook(char* prog, Authctxt *authctxt,
95 int startup, int save);
99 extern ServerOptions options;
100 extern char *__progname;
101 extern int log_stderr;
102 extern int debug_flag;
103 extern u_int utmp_len;
104 extern int startup_pipe;
105 extern void destroy_sensitive_data(void);
106 extern Buffer loginmsg;
108 /* original command from peer. */
109 const char *original_command = NULL;
112 #define MAX_SESSIONS 10
113 Session sessions[MAX_SESSIONS];
115 #ifdef HAVE_LOGIN_CAP
119 static int is_child = 0;
121 /* Name and directory of socket for authentication agent forwarding. */
122 static char *auth_sock_name = NULL;
123 static char *auth_sock_dir = NULL;
125 /* removes the agent forwarding socket */
128 auth_sock_cleanup_proc(struct passwd *pw)
130 if (auth_sock_name != NULL) {
131 temporarily_use_uid(pw);
132 unlink(auth_sock_name);
133 rmdir(auth_sock_dir);
134 auth_sock_name = NULL;
140 auth_input_request_forwarding(struct passwd * pw)
144 struct sockaddr_un sunaddr;
146 if (auth_sock_name != NULL) {
147 error("authentication forwarding requested twice.");
151 /* Temporarily drop privileged uid for mkdir/bind. */
152 temporarily_use_uid(pw);
154 /* Allocate a buffer for the socket name, and format the name. */
155 auth_sock_name = xmalloc(MAXPATHLEN);
156 auth_sock_dir = xmalloc(MAXPATHLEN);
157 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
159 /* Create private directory for socket */
160 if (mkdtemp(auth_sock_dir) == NULL) {
161 packet_send_debug("Agent forwarding disabled: "
162 "mkdtemp() failed: %.100s", strerror(errno));
164 xfree(auth_sock_name);
165 xfree(auth_sock_dir);
166 auth_sock_name = NULL;
167 auth_sock_dir = NULL;
170 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
171 auth_sock_dir, (long) getpid());
173 /* Create the socket. */
174 sock = socket(AF_UNIX, SOCK_STREAM, 0);
176 packet_disconnect("socket: %.100s", strerror(errno));
178 /* Bind it to the name. */
179 memset(&sunaddr, 0, sizeof(sunaddr));
180 sunaddr.sun_family = AF_UNIX;
181 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
183 if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
184 packet_disconnect("bind: %.100s", strerror(errno));
186 /* Restore the privileged uid. */
189 /* Start listening on the socket. */
190 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
191 packet_disconnect("listen: %.100s", strerror(errno));
193 /* Allocate a channel for the authentication agent socket. */
194 nc = channel_new("auth socket",
195 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
196 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
197 0, "auth socket", 1);
198 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
203 display_loginmsg(void)
205 if (buffer_len(&loginmsg) > 0) {
206 buffer_append(&loginmsg, "\0", 1);
207 printf("%s", (char *)buffer_ptr(&loginmsg));
208 buffer_clear(&loginmsg);
213 do_authenticated(Authctxt *authctxt)
215 setproctitle("%s", authctxt->pw->pw_name);
218 * Cancel the alarm we set to limit the time taken for
222 if (startup_pipe != -1) {
226 /* setup the channel layer */
227 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
228 channel_permit_all_opens();
231 do_authenticated2(authctxt);
233 do_authenticated1(authctxt);
236 if (options.session_hooks_allow &&
237 options.session_hooks_shutdown_cmd)
239 execute_session_hook(options.session_hooks_shutdown_cmd,
241 /* startup = */ 0, /* save = */ 0);
243 if (authctxt->session_env_file)
245 free(authctxt->session_env_file);
250 do_cleanup(authctxt);
254 * Prepares for an interactive session. This is called after the user has
255 * been successfully authenticated. During this message exchange, pseudo
256 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
257 * are requested, etc.
260 do_authenticated1(Authctxt *authctxt)
264 int success, type, screen_flag;
265 int enable_compression_after_reply = 0;
266 u_int proto_len, data_len, dlen, compression_level = 0;
270 error("no more sessions");
273 s->authctxt = authctxt;
274 s->pw = authctxt->pw;
277 * We stay in this loop until the client requests to execute a shell
283 /* Get a packet from the client. */
284 type = packet_read();
286 /* Process the packet. */
288 case SSH_CMSG_REQUEST_COMPRESSION:
289 compression_level = packet_get_int();
291 if (compression_level < 1 || compression_level > 9) {
292 packet_send_debug("Received invalid compression level %d.",
296 if (options.compression == COMP_NONE) {
297 debug2("compression disabled");
300 /* Enable compression after we have responded with SUCCESS. */
301 enable_compression_after_reply = 1;
305 case SSH_CMSG_REQUEST_PTY:
306 success = session_pty_req(s);
309 case SSH_CMSG_X11_REQUEST_FORWARDING:
310 s->auth_proto = packet_get_string(&proto_len);
311 s->auth_data = packet_get_string(&data_len);
313 screen_flag = packet_get_protocol_flags() &
314 SSH_PROTOFLAG_SCREEN_NUMBER;
315 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
317 if (packet_remaining() == 4) {
319 debug2("Buggy client: "
320 "X11 screen flag missing");
321 s->screen = packet_get_int();
326 success = session_setup_x11fwd(s);
328 xfree(s->auth_proto);
330 s->auth_proto = NULL;
335 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
336 if (no_agent_forwarding_flag || compat13) {
337 debug("Authentication agent forwarding not permitted for this authentication.");
340 debug("Received authentication agent forwarding request.");
341 success = auth_input_request_forwarding(s->pw);
344 case SSH_CMSG_PORT_FORWARD_REQUEST:
345 if (no_port_forwarding_flag) {
346 debug("Port forwarding not permitted for this authentication.");
349 if (!options.allow_tcp_forwarding) {
350 debug("Port forwarding not permitted.");
353 debug("Received TCP/IP port forwarding request.");
354 channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
358 case SSH_CMSG_MAX_PACKET_SIZE:
359 if (packet_set_maxsize(packet_get_int()) > 0)
363 case SSH_CMSG_EXEC_SHELL:
364 case SSH_CMSG_EXEC_CMD:
365 if (type == SSH_CMSG_EXEC_CMD) {
366 command = packet_get_string(&dlen);
367 debug("Exec command '%.500s'", command);
379 * Any unknown messages in this phase are ignored,
380 * and a failure message is returned.
382 logit("Unknown packet type received after authentication: %d", type);
384 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
388 /* Enable compression now that we have replied if appropriate. */
389 if (enable_compression_after_reply) {
390 enable_compression_after_reply = 0;
391 packet_start_compression(compression_level);
397 * This is called to fork and execute a command when we have no tty. This
398 * will call do_child from the child, and server_loop from the parent after
399 * setting up file descriptors and such.
402 do_exec_no_pty(Session *s, const char *command)
407 int pin[2], pout[2], perr[2];
408 /* Allocate pipes for communicating with the program. */
409 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
410 packet_disconnect("Could not create pipes: %.100s",
412 #else /* USE_PIPES */
413 int inout[2], err[2];
414 /* Uses socket pairs to communicate with the program. */
415 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
416 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
417 packet_disconnect("Could not create socket pairs: %.100s",
419 #endif /* USE_PIPES */
421 fatal("do_exec_no_pty: no session");
423 session_proctitle(s);
426 if (options.use_pam && !use_privsep)
430 /* Fork the child. */
431 if ((pid = fork()) == 0) {
434 /* Child. Reinitialize the log since the pid has changed. */
435 log_init(__progname, options.log_level, options.log_facility, log_stderr);
438 * Create a new session and process group since the 4.4BSD
439 * setlogin() affects the entire process group.
442 error("setsid failed: %.100s", strerror(errno));
446 * Redirect stdin. We close the parent side of the socket
447 * pair, and make the child side the standard input.
450 if (dup2(pin[0], 0) < 0)
451 perror("dup2 stdin");
454 /* Redirect stdout. */
456 if (dup2(pout[1], 1) < 0)
457 perror("dup2 stdout");
460 /* Redirect stderr. */
462 if (dup2(perr[1], 2) < 0)
463 perror("dup2 stderr");
465 #else /* USE_PIPES */
467 * Redirect stdin, stdout, and stderr. Stdin and stdout will
468 * use the same socket, as some programs (particularly rdist)
469 * seem to depend on it.
473 if (dup2(inout[0], 0) < 0) /* stdin */
474 perror("dup2 stdin");
475 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
476 perror("dup2 stdout");
477 if (dup2(err[0], 2) < 0) /* stderr */
478 perror("dup2 stderr");
479 #endif /* USE_PIPES */
482 cray_init_job(s->pw); /* set up cray jid and tmpdir */
485 /* Do processing for the child (exec command etc). */
486 do_child(s, command);
490 signal(WJSIGNAL, cray_job_termination_handler);
494 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
497 packet_disconnect("fork failed: %.100s", strerror(errno));
499 /* Set interactive/non-interactive mode. */
500 packet_set_interactive(s->display != NULL);
502 /* We are the parent. Close the child sides of the pipes. */
508 if (s->is_subsystem) {
512 session_set_fds(s, pin[1], pout[0], perr[0]);
514 /* Enter the interactive session. */
515 server_loop(pid, pin[1], pout[0], perr[0]);
516 /* server_loop has closed pin[1], pout[0], and perr[0]. */
518 #else /* USE_PIPES */
519 /* We are the parent. Close the child sides of the socket pairs. */
524 * Clear loginmsg, since it's the child's responsibility to display
525 * it to the user, otherwise multiple sessions may accumulate
526 * multiple copies of the login messages.
528 buffer_clear(&loginmsg);
531 * Enter the interactive session. Note: server_loop must be able to
532 * handle the case that fdin and fdout are the same.
535 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
537 server_loop(pid, inout[1], inout[1], err[1]);
538 /* server_loop has closed inout[1] and err[1]. */
540 #endif /* USE_PIPES */
544 * This is called to fork and execute a command when we have a tty. This
545 * will call do_child from the child, and server_loop from the parent after
546 * setting up file descriptors, controlling tty, updating wtmp, utmp,
547 * lastlog, and other such operations.
550 do_exec_pty(Session *s, const char *command)
552 int fdout, ptyfd, ttyfd, ptymaster;
556 fatal("do_exec_pty: no session");
561 if (options.use_pam) {
562 do_pam_set_tty(s->tty);
568 /* Fork the child. */
569 if ((pid = fork()) == 0) {
572 /* Child. Reinitialize the log because the pid has changed. */
573 log_init(__progname, options.log_level, options.log_facility, log_stderr);
574 /* Close the master side of the pseudo tty. */
577 /* Make the pseudo tty our controlling tty. */
578 pty_make_controlling_tty(&ttyfd, s->tty);
580 /* Redirect stdin/stdout/stderr from the pseudo tty. */
581 if (dup2(ttyfd, 0) < 0)
582 error("dup2 stdin: %s", strerror(errno));
583 if (dup2(ttyfd, 1) < 0)
584 error("dup2 stdout: %s", strerror(errno));
585 if (dup2(ttyfd, 2) < 0)
586 error("dup2 stderr: %s", strerror(errno));
588 /* Close the extra descriptor for the pseudo tty. */
591 /* record login, etc. similar to login(1) */
593 if (!(options.use_login && command == NULL)) {
595 cray_init_job(s->pw); /* set up cray jid and tmpdir */
597 do_login(s, command);
599 # ifdef LOGIN_NEEDS_UTMPX
605 /* Do common processing for the child, such as execing the command. */
606 do_child(s, command);
610 signal(WJSIGNAL, cray_job_termination_handler);
614 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
617 packet_disconnect("fork failed: %.100s", strerror(errno));
620 /* Parent. Close the slave side of the pseudo tty. */
624 * Create another descriptor of the pty master side for use as the
625 * standard input. We could use the original descriptor, but this
626 * simplifies code in server_loop. The descriptor is bidirectional.
630 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
632 /* we keep a reference to the pty master */
633 ptymaster = dup(ptyfd);
635 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
636 s->ptymaster = ptymaster;
638 /* Enter interactive session. */
639 packet_set_interactive(1);
641 session_set_fds(s, ptyfd, fdout, -1);
643 server_loop(pid, ptyfd, fdout, -1);
644 /* server_loop _has_ closed ptyfd and fdout. */
648 #ifdef LOGIN_NEEDS_UTMPX
650 do_pre_login(Session *s)
653 struct sockaddr_storage from;
654 pid_t pid = getpid();
657 * Get IP address of client. If the connection is not a socket, let
658 * the address be 0.0.0.0.
660 memset(&from, 0, sizeof(from));
661 fromlen = sizeof(from);
662 if (packet_connection_is_on_socket()) {
663 if (getpeername(packet_get_connection_in(),
664 (struct sockaddr *) & from, &fromlen) < 0) {
665 debug("getpeername: %.100s", strerror(errno));
670 record_utmp_only(pid, s->tty, s->pw->pw_name,
671 get_remote_name_or_ip(utmp_len, options.use_dns),
672 (struct sockaddr *)&from, fromlen);
677 * This is called to fork and execute a command. If another command is
678 * to be forced, execute that instead.
681 do_exec(Session *s, const char *command)
683 if (forced_command) {
684 original_command = command;
685 command = forced_command;
686 debug("Forced command '%.900s'", command);
689 #if defined(SESSION_HOOKS)
690 if (options.session_hooks_allow &&
691 (options.session_hooks_startup_cmd ||
692 options.session_hooks_shutdown_cmd))
700 "/tmp/ssh_env_%d%d%d",
704 } while (stat(env_file, &st)==0);
705 s->authctxt->session_env_file = strdup(env_file);
709 #ifdef SSH_AUDIT_EVENTS
711 PRIVSEP(audit_run_command(command));
712 else if (s->ttyfd == -1) {
713 char *shell = s->pw->pw_shell;
715 if (shell[0] == '\0') /* empty shell means /bin/sh */
717 PRIVSEP(audit_run_command(shell));
722 do_exec_pty(s, command);
724 do_exec_no_pty(s, command);
726 original_command = NULL;
729 * Clear loginmsg: it's the child's responsibility to display
730 * it to the user, otherwise multiple sessions may accumulate
731 * multiple copies of the login messages.
733 buffer_clear(&loginmsg);
736 /* administrative, login(1)-like work */
738 do_login(Session *s, const char *command)
741 struct sockaddr_storage from;
742 struct passwd * pw = s->pw;
743 pid_t pid = getpid();
746 * Get IP address of client. If the connection is not a socket, let
747 * the address be 0.0.0.0.
749 memset(&from, 0, sizeof(from));
750 fromlen = sizeof(from);
751 if (packet_connection_is_on_socket()) {
752 if (getpeername(packet_get_connection_in(),
753 (struct sockaddr *) & from, &fromlen) < 0) {
754 debug("getpeername: %.100s", strerror(errno));
759 /* Record that there was a login on that tty from the remote host. */
761 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
762 get_remote_name_or_ip(utmp_len,
764 (struct sockaddr *)&from, fromlen);
768 * If password change is needed, do it now.
769 * This needs to occur before the ~/.hushlogin check.
771 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
774 s->authctxt->force_pwchange = 0;
775 /* XXX - signal [net] parent to enable forwardings */
779 if (check_quietlogin(s, command))
788 * Display the message of the day.
796 if (options.print_motd) {
797 #ifdef HAVE_LOGIN_CAP
798 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
801 f = fopen("/etc/motd", "r");
804 while (fgets(buf, sizeof(buf), f))
813 * Check for quiet login, either .hushlogin or command given.
816 check_quietlogin(Session *s, const char *command)
819 struct passwd *pw = s->pw;
822 /* Return 1 if .hushlogin exists or a command given. */
825 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
826 #ifdef HAVE_LOGIN_CAP
827 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
830 if (stat(buf, &st) >= 0)
837 * Sets the value of the given variable in the environment. If the variable
838 * already exists, its value is overriden.
841 child_set_env(char ***envp, u_int *envsizep, const char *name,
849 * If we're passed an uninitialized list, allocate a single null
850 * entry before continuing.
852 if (*envp == NULL && *envsizep == 0) {
853 *envp = xmalloc(sizeof(char *));
859 * Find the slot where the value should be stored. If the variable
860 * already exists, we reuse the slot; otherwise we append a new slot
861 * at the end of the array, expanding if necessary.
864 namelen = strlen(name);
865 for (i = 0; env[i]; i++)
866 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
869 /* Reuse the slot. */
872 /* New variable. Expand if necessary. */
874 if (i >= envsize - 1) {
876 fatal("child_set_env: too many env vars");
878 env = (*envp) = xrealloc(env, envsize * sizeof(char *));
881 /* Need to set the NULL pointer at end of array beyond the new slot. */
885 /* Allocate space and format the variable in the appropriate slot. */
886 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
887 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
891 * Reads environment variables from the given file and adds/overrides them
892 * into the environment. If the file does not exist, this does nothing.
893 * Otherwise, it must consist of empty lines, comments (line starts with '#')
894 * and assignments of the form name=value. No other forms are allowed.
897 read_environment_file(char ***env, u_int *envsize,
898 const char *filename)
905 f = fopen(filename, "r");
909 while (fgets(buf, sizeof(buf), f)) {
911 fatal("Too many lines in environment file %s", filename);
912 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
914 if (!*cp || *cp == '#' || *cp == '\n')
916 if (strchr(cp, '\n'))
917 *strchr(cp, '\n') = '\0';
918 value = strchr(cp, '=');
920 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
925 * Replace the equals sign by nul, and advance value to
930 child_set_env(env, envsize, cp, value);
936 #define SSH_SESSION_ENV_FILE "SSH_SESSION_ENV_FILE"
938 typedef enum { no_op, execute, clear_env, restore_env,
939 read_env, save_or_rm_env } session_action_t;
941 static session_action_t action_order[2][5] = {
942 { clear_env, read_env, execute, save_or_rm_env, restore_env }, /*shutdown*/
943 { execute, read_env, save_or_rm_env, no_op, no_op } /*startup */
947 void execute_session_hook(char* prog, Authctxt *authctxt,
948 int startup, int save)
950 extern char **environ;
953 char **saved_env, **tmpenv;
954 char *env_file = authctxt->session_env_file;
959 switch (action_order[startup][i])
972 authctxt->pw->pw_shell,
975 debug("executing session hook: [%s]", buf);
976 setenv(SSH_SESSION_ENV_FILE, env_file, /* overwrite = */ 1);
978 /* flusing is recommended in the popen(3) man page, to avoid
979 intermingling of output */
982 if ((fp=popen(buf, "w")) == NULL)
984 perror("Unable to run session hook");
988 debug2("session hook executed, status=%d", status);
989 unsetenv(SSH_SESSION_ENV_FILE);
995 tmpenv = (char**) malloc(sizeof(char*));
1001 environ = saved_env;
1006 if (status==0 && stat(env_file, &st)==0)
1010 debug("reading environment from %s", env_file);
1011 while (environ[envsize++]) ;
1012 read_environment_file(&environ, &envsize, env_file);
1016 case save_or_rm_env:
1017 if (status==0 && save)
1022 debug2("saving environment to %s", env_file);
1023 if ((fp = fopen(env_file, "w")) == NULL) /* hmm: file perms? */
1025 perror("Unable to save session hook info");
1027 while (environ[envcount])
1029 fprintf(fp, "%s\n", environ[envcount++]);
1034 else if (stat(env_file, &st)==0)
1036 debug2("removing environment file %s", env_file);
1046 #ifdef HAVE_ETC_DEFAULT_LOGIN
1048 * Return named variable from specified environment, or NULL if not present.
1051 child_get_env(char **env, const char *name)
1057 for (i=0; env[i] != NULL; i++)
1058 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
1059 return(env[i] + len + 1);
1064 * Read /etc/default/login.
1065 * We pick up the PATH (or SUPATH for root) and UMASK.
1068 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
1070 char **tmpenv = NULL, *var;
1071 u_int i, tmpenvsize = 0;
1075 * We don't want to copy the whole file to the child's environment,
1076 * so we use a temporary environment and copy the variables we're
1079 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
1085 var = child_get_env(tmpenv, "SUPATH");
1087 var = child_get_env(tmpenv, "PATH");
1089 child_set_env(env, envsize, "PATH", var);
1091 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
1092 if (sscanf(var, "%5lo", &mask) == 1)
1093 umask((mode_t)mask);
1095 for (i = 0; tmpenv[i] != NULL; i++)
1099 #endif /* HAVE_ETC_DEFAULT_LOGIN */
1102 copy_environment(char **source, char ***env, u_int *envsize)
1104 char *var_name, *var_val;
1110 for(i = 0; source[i] != NULL; i++) {
1111 var_name = xstrdup(source[i]);
1112 if ((var_val = strstr(var_name, "=")) == NULL) {
1118 debug3("Copy environment: %s=%s", var_name, var_val);
1119 child_set_env(env, envsize, var_name, var_val);
1126 do_setup_env(Session *s, const char *shell)
1130 char **env, *laddr, *path = NULL;
1131 struct passwd *pw = s->pw;
1133 /* Initialize the environment. */
1135 env = xmalloc(envsize * sizeof(char *));
1140 * The Windows environment contains some setting which are
1141 * important for a running system. They must not be dropped.
1146 p = fetch_windows_environment();
1147 copy_environment(p, &env, &envsize);
1148 free_windows_environment(p);
1153 /* Allow any GSSAPI methods that we've used to alter
1154 * the childs environment as they see fit
1156 ssh_gssapi_do_child(&env, &envsize);
1159 if (!options.use_login) {
1160 /* Set basic environment. */
1161 for (i = 0; i < s->num_env; i++)
1162 child_set_env(&env, &envsize, s->env[i].name,
1165 child_set_env(&env, &envsize, "USER", pw->pw_name);
1166 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1168 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1170 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1171 #ifdef HAVE_LOGIN_CAP
1172 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1173 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1175 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1176 #else /* HAVE_LOGIN_CAP */
1177 # ifndef HAVE_CYGWIN
1179 * There's no standard path on Windows. The path contains
1180 * important components pointing to the system directories,
1181 * needed for loading shared libraries. So the path better
1182 * remains intact here.
1184 # ifdef HAVE_ETC_DEFAULT_LOGIN
1185 read_etc_default_login(&env, &envsize, pw->pw_uid);
1186 path = child_get_env(env, "PATH");
1187 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1188 if (path == NULL || *path == '\0') {
1189 child_set_env(&env, &envsize, "PATH",
1190 s->pw->pw_uid == 0 ?
1191 SUPERUSER_PATH : _PATH_STDPATH);
1193 # endif /* HAVE_CYGWIN */
1194 #endif /* HAVE_LOGIN_CAP */
1196 snprintf(buf, sizeof buf, "%.200s/%.50s",
1197 _PATH_MAILDIR, pw->pw_name);
1198 child_set_env(&env, &envsize, "MAIL", buf);
1200 /* Normal systems set SHELL by default. */
1201 child_set_env(&env, &envsize, "SHELL", shell);
1204 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1206 #ifdef GSI /* GSI shared libs typically installed in non-system locations. */
1210 if ((cp = getenv("LD_LIBRARY_PATH")) != NULL)
1211 child_set_env(&env, &envsize, "LD_LIBRARY_PATH", cp);
1212 if ((cp = getenv("LIBPATH")) != NULL)
1213 child_set_env(&env, &envsize, "LIBPATH", cp);
1214 if ((cp = getenv("SHLIB_PATH")) != NULL)
1215 child_set_env(&env, &envsize, "SHLIB_PATH", cp);
1216 if ((cp = getenv("LD_LIBRARYN32_PATH")) != NULL)
1217 child_set_env(&env, &envsize, "LD_LIBRARYN32_PATH",cp);
1218 if ((cp = getenv("LD_LIBRARY64_PATH")) != NULL)
1219 child_set_env(&env, &envsize, "LD_LIBRARY64_PATH",cp);
1223 /* Set custom environment options from RSA authentication. */
1224 if (!options.use_login) {
1225 while (custom_environment) {
1226 struct envstring *ce = custom_environment;
1229 for (i = 0; str[i] != '=' && str[i]; i++)
1231 if (str[i] == '=') {
1233 child_set_env(&env, &envsize, str, str + i + 1);
1235 custom_environment = ce->next;
1241 /* SSH_CLIENT deprecated */
1242 snprintf(buf, sizeof buf, "%.50s %d %d",
1243 get_remote_ipaddr(), get_remote_port(), get_local_port());
1244 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1246 laddr = get_local_ipaddr(packet_get_connection_in());
1247 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1248 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1250 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1253 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1255 child_set_env(&env, &envsize, "TERM", s->term);
1257 child_set_env(&env, &envsize, "DISPLAY", s->display);
1258 if (original_command)
1259 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1263 if (cray_tmpdir[0] != '\0')
1264 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1265 #endif /* _UNICOS */
1268 * Since we clear KRB5CCNAME at startup, if it's set now then it
1269 * must have been set by a native authentication method (eg AIX or
1270 * SIA), so copy it to the child.
1275 if ((cp = getenv("KRB5CCNAME")) != NULL)
1276 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1283 if ((cp = getenv("AUTHSTATE")) != NULL)
1284 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1285 read_environment_file(&env, &envsize, "/etc/environment");
1289 if (s->authctxt->krb5_ccname)
1290 child_set_env(&env, &envsize, "KRB5CCNAME",
1291 s->authctxt->krb5_ccname);
1295 * Pull in any environment variables that may have
1298 if (options.use_pam) {
1301 p = fetch_pam_child_environment();
1302 copy_environment(p, &env, &envsize);
1303 free_pam_environment(p);
1305 p = fetch_pam_environment();
1306 copy_environment(p, &env, &envsize);
1307 free_pam_environment(p);
1309 #endif /* USE_PAM */
1311 if (auth_sock_name != NULL)
1312 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1315 /* read $HOME/.ssh/environment. */
1316 if (options.permit_user_env && !options.use_login) {
1317 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1318 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1319 read_environment_file(&env, &envsize, buf);
1322 /* dump the environment */
1323 fprintf(stderr, "Environment:\n");
1324 for (i = 0; env[i]; i++)
1325 fprintf(stderr, " %.200s\n", env[i]);
1331 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1332 * first in this order).
1335 do_rc_files(Session *s, const char *shell)
1343 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1345 /* ignore _PATH_SSH_USER_RC for subsystems */
1346 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1347 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1348 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1350 fprintf(stderr, "Running %s\n", cmd);
1351 f = popen(cmd, "w");
1354 fprintf(f, "%s %s\n", s->auth_proto,
1358 fprintf(stderr, "Could not run %s\n",
1360 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1362 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1363 _PATH_SSH_SYSTEM_RC);
1364 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1367 fprintf(f, "%s %s\n", s->auth_proto,
1371 fprintf(stderr, "Could not run %s\n",
1372 _PATH_SSH_SYSTEM_RC);
1373 } else if (do_xauth && options.xauth_location != NULL) {
1374 /* Add authority data to .Xauthority if appropriate. */
1377 "Running %.500s remove %.100s\n",
1378 options.xauth_location, s->auth_display);
1380 "%.500s add %.100s %.100s %.100s\n",
1381 options.xauth_location, s->auth_display,
1382 s->auth_proto, s->auth_data);
1384 snprintf(cmd, sizeof cmd, "%s -q -",
1385 options.xauth_location);
1386 f = popen(cmd, "w");
1388 fprintf(f, "remove %s\n",
1390 fprintf(f, "add %s %s %s\n",
1391 s->auth_display, s->auth_proto,
1395 fprintf(stderr, "Could not run %s\n",
1402 do_nologin(struct passwd *pw)
1407 #ifdef HAVE_LOGIN_CAP
1408 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1409 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1410 _PATH_NOLOGIN), "r");
1413 f = fopen(_PATH_NOLOGIN, "r");
1416 /* /etc/nologin exists. Print its contents and exit. */
1417 logit("User %.100s not allowed because %s exists",
1418 pw->pw_name, _PATH_NOLOGIN);
1419 while (fgets(buf, sizeof(buf), f))
1427 /* Set login name, uid, gid, and groups. */
1429 do_setusercontext(struct passwd *pw)
1432 if (getuid() == 0 || geteuid() == 0)
1433 #endif /* HAVE_CYGWIN */
1436 #ifdef HAVE_SETPCRED
1437 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1438 fatal("Failed to set process credentials");
1439 #endif /* HAVE_SETPCRED */
1440 #ifdef HAVE_LOGIN_CAP
1445 if (options.gss_authentication) {
1446 temporarily_use_uid(pw);
1447 ssh_gssapi_storecreds();
1452 if (options.use_pam) {
1456 # endif /* USE_PAM */
1457 if (setusercontext(lc, pw, pw->pw_uid,
1458 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1459 perror("unable to set user context");
1463 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1464 /* Sets login uid for accounting */
1465 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1466 error("setluid: %s", strerror(errno));
1467 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1469 if (setlogin(pw->pw_name) < 0)
1470 error("setlogin failed: %s", strerror(errno));
1471 if (setgid(pw->pw_gid) < 0) {
1475 /* Initialize the group list. */
1476 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1477 perror("initgroups");
1482 if (options.gss_authentication) {
1483 temporarily_use_uid(pw);
1484 ssh_gssapi_storecreds();
1490 * PAM credentials may take the form of supplementary groups.
1491 * These will have been wiped by the above initgroups() call.
1492 * Reestablish them here.
1494 if (options.use_pam) {
1498 # endif /* USE_PAM */
1499 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1500 irix_setusercontext(pw);
1501 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1505 #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
1506 if (set_id(pw->pw_name) != 0) {
1509 #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
1510 /* Permanently switch to the desired uid. */
1511 permanently_set_uid(pw);
1518 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1519 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1523 do_pwchange(Session *s)
1526 fprintf(stderr, "WARNING: Your password has expired.\n");
1527 if (s->ttyfd != -1) {
1529 "You must change your password now and login again!\n");
1530 #ifdef PASSWD_NEEDS_USERNAME
1531 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1534 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1539 "Password change required but no TTY available.\n");
1545 launch_login(struct passwd *pw, const char *hostname)
1547 /* Launch login(1). */
1549 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1550 #ifdef xxxLOGIN_NEEDS_TERM
1551 (s->term ? s->term : "unknown"),
1552 #endif /* LOGIN_NEEDS_TERM */
1553 #ifdef LOGIN_NO_ENDOPT
1554 "-p", "-f", pw->pw_name, (char *)NULL);
1556 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1559 /* Login couldn't be executed, die. */
1566 child_close_fds(void)
1570 if (packet_get_connection_in() == packet_get_connection_out())
1571 close(packet_get_connection_in());
1573 close(packet_get_connection_in());
1574 close(packet_get_connection_out());
1577 * Close all descriptors related to channels. They will still remain
1578 * open in the parent.
1580 /* XXX better use close-on-exec? -markus */
1581 channel_close_all();
1584 * Close any extra file descriptors. Note that there may still be
1585 * descriptors left by system functions. They will be closed later.
1590 * Close any extra open file descriptors so that we don\'t have them
1591 * hanging around in clients. Note that we want to do this after
1592 * initgroups, because at least on Solaris 2.3 it leaves file
1595 for (i = 3; i < 64; i++)
1600 * Performs common processing for the child, such as setting up the
1601 * environment, closing extra file descriptors, setting the user and group
1602 * ids, and executing the command or shell.
1605 do_child(Session *s, const char *command)
1607 extern char **environ;
1610 const char *shell, *shell0, *hostname = NULL;
1611 struct passwd *pw = s->pw;
1614 /* Default place to look for aklog. */
1616 #define KPROGDIR AKLOG_PATH
1618 #define KPROGDIR "/usr/bin/aklog"
1619 #endif /* AKLOG_PATH */
1623 #endif /* AFS_KRB5 */
1625 /* remove hostkey from the child's memory */
1626 destroy_sensitive_data();
1628 /* Force a password change */
1629 if (s->authctxt->force_pwchange) {
1630 do_setusercontext(pw);
1636 /* login(1) is only called if we execute the login shell */
1637 if (options.use_login && command != NULL)
1638 options.use_login = 0;
1641 cray_setup(pw->pw_uid, pw->pw_name, command);
1642 #endif /* _UNICOS */
1645 * Login(1) does this as well, and it needs uid 0 for the "-h"
1646 * switch, so we let login(1) to this for us.
1648 if (!options.use_login) {
1650 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1651 if (!check_quietlogin(s, command))
1653 #else /* HAVE_OSF_SIA */
1655 do_setusercontext(pw);
1657 * PAM session modules in do_setusercontext may have
1658 * generated messages, so if this in an interactive
1659 * login then display them too.
1661 if (!check_quietlogin(s, command))
1663 #endif /* HAVE_OSF_SIA */
1667 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1668 debug3("PAM session not opened, exiting");
1675 * Get the shell from the password data. An empty shell field is
1676 * legal, and means /bin/sh.
1678 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1681 * Make sure $SHELL points to the shell from the password file,
1682 * even if shell is overridden from login.conf
1684 env = do_setup_env(s, shell);
1686 #ifdef HAVE_LOGIN_CAP
1687 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1690 /* we have to stash the hostname before we close our socket. */
1691 if (options.use_login)
1692 hostname = get_remote_name_or_ip(utmp_len,
1695 * Close the connection descriptors; note that this is the child, and
1696 * the server will still have the socket open, and it is important
1697 * that we do not shutdown it. Note that the descriptors cannot be
1698 * closed before building the environment, as we call
1699 * get_remote_ipaddr there.
1704 * Must take new environment into use so that .ssh/rc,
1705 * /etc/ssh/sshrc and xauth are run in the proper environment.
1709 #if defined(KRB5) && defined(USE_AFS)
1711 * At this point, we check to see if AFS is active and if we have
1712 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1713 * if we can (and need to) extend the ticket into an AFS token. If
1714 * we don't do this, we run into potential problems if the user's
1715 * home directory is in AFS and it's not world-readable.
1718 if (options.kerberos_get_afs_token && k_hasafs() &&
1719 (s->authctxt->krb5_ctx != NULL)) {
1722 debug("Getting AFS token");
1726 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1727 krb5_afslog(s->authctxt->krb5_ctx,
1728 s->authctxt->krb5_fwd_ccache, cell, NULL);
1730 krb5_afslog_home(s->authctxt->krb5_ctx,
1731 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1737 /* User has authenticated, and if a ticket was going to be
1738 * passed we would have it. KRB5CCNAME should already be set.
1739 * Now try to get an AFS token using aklog.
1741 if (k_hasafs()) { /* Do we have AFS? */
1743 aklog_path = xstrdup(KPROGDIR);
1746 * Make sure it exists before we try to run it
1748 if (stat(aklog_path, &st) == 0) {
1749 debug("Running %s to get afs token.",aklog_path);
1752 debug("%s does not exist.",aklog_path);
1757 #endif /* AFS_KRB5 */
1759 #ifdef SESSION_HOOKS
1760 if (options.session_hooks_allow &&
1761 options.session_hooks_startup_cmd)
1763 execute_session_hook(options.session_hooks_startup_cmd,
1766 options.session_hooks_shutdown_cmd != NULL);
1770 /* Change current directory to the user\'s home directory. */
1771 if (chdir(pw->pw_dir) < 0) {
1772 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1773 pw->pw_dir, strerror(errno));
1774 #ifdef HAVE_LOGIN_CAP
1775 if (login_getcapbool(lc, "requirehome", 0))
1780 if (!options.use_login)
1781 do_rc_files(s, shell);
1783 /* restore SIGPIPE for child */
1784 signal(SIGPIPE, SIG_DFL);
1786 if (options.use_login) {
1787 launch_login(pw, hostname);
1791 /* Get the last component of the shell name. */
1792 if ((shell0 = strrchr(shell, '/')) != NULL)
1798 * If we have no command, execute the shell. In this case, the shell
1799 * name to be passed in argv[0] is preceded by '-' to indicate that
1800 * this is a login shell.
1805 /* Start the shell. Set initial character to '-'. */
1808 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1809 >= sizeof(argv0) - 1) {
1815 /* Execute the shell. */
1818 execve(shell, argv, environ);
1820 /* Executing the shell failed. */
1825 * Execute the command using the user's shell. This uses the -c
1826 * option to execute the command.
1828 argv[0] = (char *) shell0;
1830 argv[2] = (char *) command;
1832 execve(shell, argv, environ);
1841 static int did_init = 0;
1843 debug("session_new: init");
1844 for (i = 0; i < MAX_SESSIONS; i++) {
1845 sessions[i].used = 0;
1849 for (i = 0; i < MAX_SESSIONS; i++) {
1850 Session *s = &sessions[i];
1852 memset(s, 0, sizeof(*s));
1858 s->x11_chanids = NULL;
1859 debug("session_new: session %d", i);
1870 for (i = 0; i < MAX_SESSIONS; i++) {
1871 Session *s = &sessions[i];
1872 debug("dump: used %d session %d %p channel %d pid %ld",
1882 session_open(Authctxt *authctxt, int chanid)
1884 Session *s = session_new();
1885 debug("session_open: channel %d", chanid);
1887 error("no more sessions");
1890 s->authctxt = authctxt;
1891 s->pw = authctxt->pw;
1892 if (s->pw == NULL || !authctxt->valid)
1893 fatal("no user for session %d", s->self);
1894 debug("session_open: session %d: link with channel %d", s->self, chanid);
1900 session_by_tty(char *tty)
1903 for (i = 0; i < MAX_SESSIONS; i++) {
1904 Session *s = &sessions[i];
1905 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1906 debug("session_by_tty: session %d tty %s", i, tty);
1910 debug("session_by_tty: unknown tty %.100s", tty);
1916 session_by_channel(int id)
1919 for (i = 0; i < MAX_SESSIONS; i++) {
1920 Session *s = &sessions[i];
1921 if (s->used && s->chanid == id) {
1922 debug("session_by_channel: session %d channel %d", i, id);
1926 debug("session_by_channel: unknown channel %d", id);
1932 session_by_x11_channel(int id)
1936 for (i = 0; i < MAX_SESSIONS; i++) {
1937 Session *s = &sessions[i];
1939 if (s->x11_chanids == NULL || !s->used)
1941 for (j = 0; s->x11_chanids[j] != -1; j++) {
1942 if (s->x11_chanids[j] == id) {
1943 debug("session_by_x11_channel: session %d "
1944 "channel %d", s->self, id);
1949 debug("session_by_x11_channel: unknown channel %d", id);
1955 session_by_pid(pid_t pid)
1958 debug("session_by_pid: pid %ld", (long)pid);
1959 for (i = 0; i < MAX_SESSIONS; i++) {
1960 Session *s = &sessions[i];
1961 if (s->used && s->pid == pid)
1964 error("session_by_pid: unknown pid %ld", (long)pid);
1970 session_window_change_req(Session *s)
1972 s->col = packet_get_int();
1973 s->row = packet_get_int();
1974 s->xpixel = packet_get_int();
1975 s->ypixel = packet_get_int();
1977 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1982 session_pty_req(Session *s)
1988 debug("Allocating a pty not permitted for this authentication.");
1991 if (s->ttyfd != -1) {
1992 packet_disconnect("Protocol error: you already have a pty.");
1996 s->term = packet_get_string(&len);
1999 s->col = packet_get_int();
2000 s->row = packet_get_int();
2002 s->row = packet_get_int();
2003 s->col = packet_get_int();
2005 s->xpixel = packet_get_int();
2006 s->ypixel = packet_get_int();
2008 if (strcmp(s->term, "") == 0) {
2013 /* Allocate a pty and open it. */
2014 debug("Allocating pty.");
2015 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
2021 error("session_pty_req: session %d alloc failed", s->self);
2024 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
2026 /* for SSH1 the tty modes length is not given */
2028 n_bytes = packet_remaining();
2029 tty_parse_modes(s->ttyfd, &n_bytes);
2032 pty_setowner(s->pw, s->tty);
2034 /* Set window size from the packet. */
2035 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
2038 session_proctitle(s);
2043 session_subsystem_req(Session *s)
2048 char *cmd, *subsys = packet_get_string(&len);
2052 logit("subsystem request for %.100s", subsys);
2054 for (i = 0; i < options.num_subsystems; i++) {
2055 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
2056 cmd = options.subsystem_command[i];
2057 if (stat(cmd, &st) < 0) {
2058 error("subsystem: cannot stat %s: %s", cmd,
2062 debug("subsystem: exec() %s", cmd);
2063 s->is_subsystem = 1;
2071 logit("subsystem request for %.100s failed, subsystem not found",
2079 session_x11_req(Session *s)
2083 if (s->auth_proto != NULL || s->auth_data != NULL) {
2084 error("session_x11_req: session %d: "
2085 "x11 fowarding already active", s->self);
2088 s->single_connection = packet_get_char();
2089 s->auth_proto = packet_get_string(NULL);
2090 s->auth_data = packet_get_string(NULL);
2091 s->screen = packet_get_int();
2094 success = session_setup_x11fwd(s);
2096 xfree(s->auth_proto);
2097 xfree(s->auth_data);
2098 s->auth_proto = NULL;
2099 s->auth_data = NULL;
2105 session_shell_req(Session *s)
2113 session_exec_req(Session *s)
2116 char *command = packet_get_string(&len);
2118 do_exec(s, command);
2124 session_break_req(Session *s)
2127 packet_get_int(); /* ignored */
2130 if (s->ttyfd == -1 ||
2131 tcsendbreak(s->ttyfd, 0) < 0)
2137 session_env_req(Session *s)
2140 u_int name_len, val_len, i;
2142 name = packet_get_string(&name_len);
2143 val = packet_get_string(&val_len);
2146 /* Don't set too many environment variables */
2147 if (s->num_env > 128) {
2148 debug2("Ignoring env request %s: too many env vars", name);
2152 for (i = 0; i < options.num_accept_env; i++) {
2153 if (match_pattern(name, options.accept_env[i])) {
2154 debug2("Setting env %d: %s=%s", s->num_env, name, val);
2155 s->env = xrealloc(s->env, sizeof(*s->env) *
2157 s->env[s->num_env].name = name;
2158 s->env[s->num_env].val = val;
2163 debug2("Ignoring env request %s: disallowed name", name);
2172 session_auth_agent_req(Session *s)
2174 static int called = 0;
2176 if (no_agent_forwarding_flag) {
2177 debug("session_auth_agent_req: no_agent_forwarding_flag");
2184 return auth_input_request_forwarding(s->pw);
2189 session_input_channel_req(Channel *c, const char *rtype)
2194 if ((s = session_by_channel(c->self)) == NULL) {
2195 logit("session_input_channel_req: no session %d req %.100s",
2199 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2202 * a session is in LARVAL state until a shell, a command
2203 * or a subsystem is executed
2205 if (c->type == SSH_CHANNEL_LARVAL) {
2206 if (strcmp(rtype, "shell") == 0) {
2207 success = session_shell_req(s);
2208 } else if (strcmp(rtype, "exec") == 0) {
2209 success = session_exec_req(s);
2210 } else if (strcmp(rtype, "pty-req") == 0) {
2211 success = session_pty_req(s);
2212 } else if (strcmp(rtype, "x11-req") == 0) {
2213 success = session_x11_req(s);
2214 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2215 success = session_auth_agent_req(s);
2216 } else if (strcmp(rtype, "subsystem") == 0) {
2217 success = session_subsystem_req(s);
2218 } else if (strcmp(rtype, "env") == 0) {
2219 success = session_env_req(s);
2222 if (strcmp(rtype, "window-change") == 0) {
2223 success = session_window_change_req(s);
2224 } else if (strcmp(rtype, "break") == 0) {
2225 success = session_break_req(s);
2232 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2235 fatal("session_set_fds: called for proto != 2.0");
2237 * now that have a child and a pipe to the child,
2238 * we can activate our channel and register the fd's
2240 if (s->chanid == -1)
2241 fatal("no channel for session %d", s->self);
2242 channel_set_fds(s->chanid,
2244 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2246 CHAN_SES_WINDOW_DEFAULT);
2250 * Function to perform pty cleanup. Also called if we get aborted abnormally
2251 * (e.g., due to a dropped connection).
2254 session_pty_cleanup2(Session *s)
2257 error("session_pty_cleanup: no session");
2263 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2265 /* Record that the user has logged out. */
2267 record_logout(s->pid, s->tty, s->pw->pw_name);
2269 /* Release the pseudo-tty. */
2271 pty_release(s->tty);
2274 * Close the server side of the socket pairs. We must do this after
2275 * the pty cleanup, so that another process doesn't get this pty
2276 * while we're still cleaning up.
2278 if (close(s->ptymaster) < 0)
2279 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2281 /* unlink pty from session */
2286 session_pty_cleanup(Session *s)
2288 PRIVSEP(session_pty_cleanup2(s));
2294 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2309 return "SIG@openssh.com";
2313 session_close_x11(int id)
2317 if ((c = channel_lookup(id)) == NULL) {
2318 debug("session_close_x11: x11 channel %d missing", id);
2320 /* Detach X11 listener */
2321 debug("session_close_x11: detach x11 channel %d", id);
2322 channel_cancel_cleanup(id);
2323 if (c->ostate != CHAN_OUTPUT_CLOSED)
2329 session_close_single_x11(int id, void *arg)
2334 debug3("session_close_single_x11: channel %d", id);
2335 channel_cancel_cleanup(id);
2336 if ((s = session_by_x11_channel(id)) == NULL)
2337 fatal("session_close_single_x11: no x11 channel %d", id);
2338 for (i = 0; s->x11_chanids[i] != -1; i++) {
2339 debug("session_close_single_x11: session %d: "
2340 "closing channel %d", s->self, s->x11_chanids[i]);
2342 * The channel "id" is already closing, but make sure we
2343 * close all of its siblings.
2345 if (s->x11_chanids[i] != id)
2346 session_close_x11(s->x11_chanids[i]);
2348 xfree(s->x11_chanids);
2349 s->x11_chanids = NULL;
2354 if (s->auth_proto) {
2355 xfree(s->auth_proto);
2356 s->auth_proto = NULL;
2359 xfree(s->auth_data);
2360 s->auth_data = NULL;
2362 if (s->auth_display) {
2363 xfree(s->auth_display);
2364 s->auth_display = NULL;
2369 session_exit_message(Session *s, int status)
2374 if ((c = channel_lookup(s->chanid)) == NULL)
2375 fatal("session_exit_message: session %d: no channel %d",
2376 s->self, s->chanid);
2377 debug("session_exit_message: session %d channel %d pid %ld",
2378 s->self, s->chanid, (long)s->pid);
2380 if (WIFEXITED(status)) {
2381 channel_request_start(s->chanid, "exit-status", 0);
2382 packet_put_int(WEXITSTATUS(status));
2384 } else if (WIFSIGNALED(status)) {
2385 channel_request_start(s->chanid, "exit-signal", 0);
2386 packet_put_cstring(sig2name(WTERMSIG(status)));
2388 packet_put_char(WCOREDUMP(status));
2389 #else /* WCOREDUMP */
2391 #endif /* WCOREDUMP */
2392 packet_put_cstring("");
2393 packet_put_cstring("");
2396 /* Some weird exit cause. Just exit. */
2397 packet_disconnect("wait returned status %04x.", status);
2400 /* disconnect channel */
2401 debug("session_exit_message: release channel %d", s->chanid);
2402 channel_cancel_cleanup(s->chanid);
2404 * emulate a write failure with 'chan_write_failed', nobody will be
2405 * interested in data we write.
2406 * Note that we must not call 'chan_read_failed', since there could
2407 * be some more data waiting in the pipe.
2409 if (c->ostate != CHAN_OUTPUT_CLOSED)
2410 chan_write_failed(c);
2413 /* Close any X11 listeners associated with this session */
2414 if (s->x11_chanids != NULL) {
2415 for (i = 0; s->x11_chanids[i] != -1; i++) {
2416 session_close_x11(s->x11_chanids[i]);
2417 s->x11_chanids[i] = -1;
2423 session_close(Session *s)
2427 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2429 session_pty_cleanup(s);
2435 xfree(s->x11_chanids);
2436 if (s->auth_display)
2437 xfree(s->auth_display);
2439 xfree(s->auth_data);
2441 xfree(s->auth_proto);
2443 for (i = 0; i < s->num_env; i++) {
2444 xfree(s->env[i].name);
2445 xfree(s->env[i].val);
2449 session_proctitle(s);
2453 session_close_by_pid(pid_t pid, int status)
2455 Session *s = session_by_pid(pid);
2457 debug("session_close_by_pid: no session for pid %ld",
2461 if (s->chanid != -1)
2462 session_exit_message(s, status);
2467 * this is called when a channel dies before
2468 * the session 'child' itself dies
2471 session_close_by_channel(int id, void *arg)
2473 Session *s = session_by_channel(id);
2476 debug("session_close_by_channel: no session for id %d", id);
2479 debug("session_close_by_channel: channel %d child %ld",
2482 debug("session_close_by_channel: channel %d: has child", id);
2484 * delay detach of session, but release pty, since
2485 * the fd's to the child are already closed
2488 session_pty_cleanup(s);
2491 /* detach by removing callback */
2492 channel_cancel_cleanup(s->chanid);
2498 session_destroy_all(void (*closefunc)(Session *))
2501 for (i = 0; i < MAX_SESSIONS; i++) {
2502 Session *s = &sessions[i];
2504 if (closefunc != NULL)
2513 session_tty_list(void)
2515 static char buf[1024];
2520 for (i = 0; i < MAX_SESSIONS; i++) {
2521 Session *s = &sessions[i];
2522 if (s->used && s->ttyfd != -1) {
2524 if (strncmp(s->tty, "/dev/", 5) != 0) {
2525 cp = strrchr(s->tty, '/');
2526 cp = (cp == NULL) ? s->tty : cp + 1;
2531 strlcat(buf, ",", sizeof buf);
2532 strlcat(buf, cp, sizeof buf);
2536 strlcpy(buf, "notty", sizeof buf);
2541 session_proctitle(Session *s)
2544 error("no user for session %d", s->self);
2546 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2550 session_setup_x11fwd(Session *s)
2553 char display[512], auth_display[512];
2554 char hostname[MAXHOSTNAMELEN];
2557 if (no_x11_forwarding_flag) {
2558 packet_send_debug("X11 forwarding disabled in user configuration file.");
2561 if (!options.x11_forwarding) {
2562 debug("X11 forwarding disabled in server configuration file.");
2565 if (!options.xauth_location ||
2566 (stat(options.xauth_location, &st) == -1)) {
2567 packet_send_debug("No xauth program; cannot forward with spoofing.");
2570 if (options.use_login) {
2571 packet_send_debug("X11 forwarding disabled; "
2572 "not compatible with UseLogin=yes.");
2575 if (s->display != NULL) {
2576 debug("X11 display already set.");
2579 if (x11_create_display_inet(options.x11_display_offset,
2580 options.x11_use_localhost, s->single_connection,
2581 &s->display_number, &s->x11_chanids) == -1) {
2582 debug("x11_create_display_inet failed.");
2585 for (i = 0; s->x11_chanids[i] != -1; i++) {
2586 channel_register_cleanup(s->x11_chanids[i],
2587 session_close_single_x11);
2590 /* Set up a suitable value for the DISPLAY variable. */
2591 if (gethostname(hostname, sizeof(hostname)) < 0)
2592 fatal("gethostname: %.100s", strerror(errno));
2594 * auth_display must be used as the displayname when the
2595 * authorization entry is added with xauth(1). This will be
2596 * different than the DISPLAY string for localhost displays.
2598 if (options.x11_use_localhost) {
2599 snprintf(display, sizeof display, "localhost:%u.%u",
2600 s->display_number, s->screen);
2601 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2602 s->display_number, s->screen);
2603 s->display = xstrdup(display);
2604 s->auth_display = xstrdup(auth_display);
2606 #ifdef IPADDR_IN_DISPLAY
2608 struct in_addr my_addr;
2610 he = gethostbyname(hostname);
2612 error("Can't get IP address for X11 DISPLAY.");
2613 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2616 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2617 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2618 s->display_number, s->screen);
2620 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2621 s->display_number, s->screen);
2623 s->display = xstrdup(display);
2624 s->auth_display = xstrdup(display);
2631 do_authenticated2(Authctxt *authctxt)
2633 server_loop2(authctxt);
2637 do_cleanup(Authctxt *authctxt)
2639 static int called = 0;
2641 debug("do_cleanup");
2643 /* no cleanup if we're in the child for login shell */
2647 /* avoid double cleanup */
2652 if (authctxt == NULL)
2655 if (options.kerberos_ticket_cleanup &&
2657 krb5_cleanup_proc(authctxt);
2661 if (compat20 && options.gss_cleanup_creds)
2662 ssh_gssapi_cleanup_creds();
2666 if (options.use_pam) {
2668 sshpam_thread_cleanup();
2672 /* remove agent socket */
2673 auth_sock_cleanup_proc(authctxt->pw);
2676 * Cleanup ptys/utmp only if privsep is disabled,
2677 * or if running in monitor.
2679 if (!use_privsep || mm_is_monitor())
2680 session_destroy_all(session_pty_cleanup2);