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 1.191 2005/12/24 02:27:41 djm 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 /* this shouldn't matter if its hpn or not - cjr */
195 nc = channel_new("auth socket",
196 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
197 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
198 0, "auth socket", 1);
199 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
204 display_loginmsg(void)
206 if (buffer_len(&loginmsg) > 0) {
207 buffer_append(&loginmsg, "\0", 1);
208 printf("%s", (char *)buffer_ptr(&loginmsg));
209 buffer_clear(&loginmsg);
214 do_authenticated(Authctxt *authctxt)
216 setproctitle("%s", authctxt->pw->pw_name);
218 /* setup the channel layer */
219 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
220 channel_permit_all_opens();
223 do_authenticated2(authctxt);
225 do_authenticated1(authctxt);
228 if (options.session_hooks_allow &&
229 options.session_hooks_shutdown_cmd)
231 execute_session_hook(options.session_hooks_shutdown_cmd,
233 /* startup = */ 0, /* save = */ 0);
235 if (authctxt->session_env_file)
237 free(authctxt->session_env_file);
242 do_cleanup(authctxt);
246 * Prepares for an interactive session. This is called after the user has
247 * been successfully authenticated. During this message exchange, pseudo
248 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
249 * are requested, etc.
252 do_authenticated1(Authctxt *authctxt)
256 int success, type, screen_flag;
257 int enable_compression_after_reply = 0;
258 u_int proto_len, data_len, dlen, compression_level = 0;
262 error("no more sessions");
265 s->authctxt = authctxt;
266 s->pw = authctxt->pw;
269 * We stay in this loop until the client requests to execute a shell
275 /* Get a packet from the client. */
276 type = packet_read();
278 /* Process the packet. */
280 case SSH_CMSG_REQUEST_COMPRESSION:
281 compression_level = packet_get_int();
283 if (compression_level < 1 || compression_level > 9) {
284 packet_send_debug("Received invalid compression level %d.",
288 if (options.compression == COMP_NONE) {
289 debug2("compression disabled");
292 /* Enable compression after we have responded with SUCCESS. */
293 enable_compression_after_reply = 1;
297 case SSH_CMSG_REQUEST_PTY:
298 success = session_pty_req(s);
301 case SSH_CMSG_X11_REQUEST_FORWARDING:
302 s->auth_proto = packet_get_string(&proto_len);
303 s->auth_data = packet_get_string(&data_len);
305 screen_flag = packet_get_protocol_flags() &
306 SSH_PROTOFLAG_SCREEN_NUMBER;
307 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
309 if (packet_remaining() == 4) {
311 debug2("Buggy client: "
312 "X11 screen flag missing");
313 s->screen = packet_get_int();
318 success = session_setup_x11fwd(s);
320 xfree(s->auth_proto);
322 s->auth_proto = NULL;
327 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
328 if (no_agent_forwarding_flag || compat13) {
329 debug("Authentication agent forwarding not permitted for this authentication.");
332 debug("Received authentication agent forwarding request.");
333 success = auth_input_request_forwarding(s->pw);
336 case SSH_CMSG_PORT_FORWARD_REQUEST:
337 if (no_port_forwarding_flag) {
338 debug("Port forwarding not permitted for this authentication.");
341 if (!options.allow_tcp_forwarding) {
342 debug("Port forwarding not permitted.");
345 debug("Received TCP/IP port forwarding request.");
346 channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports,
347 options.hpn_disabled,
348 options.hpn_buffer_size);
352 case SSH_CMSG_MAX_PACKET_SIZE:
353 if (packet_set_maxsize(packet_get_int()) > 0)
357 case SSH_CMSG_EXEC_SHELL:
358 case SSH_CMSG_EXEC_CMD:
359 if (type == SSH_CMSG_EXEC_CMD) {
360 command = packet_get_string(&dlen);
361 debug("Exec command '%.500s'", command);
373 * Any unknown messages in this phase are ignored,
374 * and a failure message is returned.
376 logit("Unknown packet type received after authentication: %d", type);
378 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
382 /* Enable compression now that we have replied if appropriate. */
383 if (enable_compression_after_reply) {
384 enable_compression_after_reply = 0;
385 packet_start_compression(compression_level);
391 * This is called to fork and execute a command when we have no tty. This
392 * will call do_child from the child, and server_loop from the parent after
393 * setting up file descriptors and such.
396 do_exec_no_pty(Session *s, const char *command)
401 int pin[2], pout[2], perr[2];
402 /* Allocate pipes for communicating with the program. */
403 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
404 packet_disconnect("Could not create pipes: %.100s",
406 #else /* USE_PIPES */
407 int inout[2], err[2];
408 /* Uses socket pairs to communicate with the program. */
409 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
410 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
411 packet_disconnect("Could not create socket pairs: %.100s",
413 #endif /* USE_PIPES */
415 fatal("do_exec_no_pty: no session");
417 session_proctitle(s);
420 if (options.use_pam && !use_privsep)
424 /* Fork the child. */
425 if ((pid = fork()) == 0) {
428 /* Child. Reinitialize the log since the pid has changed. */
429 log_init(__progname, options.log_level, options.log_facility, log_stderr);
432 * Create a new session and process group since the 4.4BSD
433 * setlogin() affects the entire process group.
436 error("setsid failed: %.100s", strerror(errno));
440 * Redirect stdin. We close the parent side of the socket
441 * pair, and make the child side the standard input.
444 if (dup2(pin[0], 0) < 0)
445 perror("dup2 stdin");
448 /* Redirect stdout. */
450 if (dup2(pout[1], 1) < 0)
451 perror("dup2 stdout");
454 /* Redirect stderr. */
456 if (dup2(perr[1], 2) < 0)
457 perror("dup2 stderr");
459 #else /* USE_PIPES */
461 * Redirect stdin, stdout, and stderr. Stdin and stdout will
462 * use the same socket, as some programs (particularly rdist)
463 * seem to depend on it.
467 if (dup2(inout[0], 0) < 0) /* stdin */
468 perror("dup2 stdin");
469 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
470 perror("dup2 stdout");
471 if (dup2(err[0], 2) < 0) /* stderr */
472 perror("dup2 stderr");
473 #endif /* USE_PIPES */
476 cray_init_job(s->pw); /* set up cray jid and tmpdir */
479 /* Do processing for the child (exec command etc). */
480 do_child(s, command);
484 signal(WJSIGNAL, cray_job_termination_handler);
488 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
491 packet_disconnect("fork failed: %.100s", strerror(errno));
493 /* Set interactive/non-interactive mode. */
494 packet_set_interactive(s->display != NULL);
496 /* We are the parent. Close the child sides of the pipes. */
502 if (s->is_subsystem) {
506 session_set_fds(s, pin[1], pout[0], perr[0]);
508 /* Enter the interactive session. */
509 server_loop(pid, pin[1], pout[0], perr[0]);
510 /* server_loop has closed pin[1], pout[0], and perr[0]. */
512 #else /* USE_PIPES */
513 /* We are the parent. Close the child sides of the socket pairs. */
518 * Clear loginmsg, since it's the child's responsibility to display
519 * it to the user, otherwise multiple sessions may accumulate
520 * multiple copies of the login messages.
522 buffer_clear(&loginmsg);
525 * Enter the interactive session. Note: server_loop must be able to
526 * handle the case that fdin and fdout are the same.
529 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
531 server_loop(pid, inout[1], inout[1], err[1]);
532 /* server_loop has closed inout[1] and err[1]. */
534 #endif /* USE_PIPES */
538 * This is called to fork and execute a command when we have a tty. This
539 * will call do_child from the child, and server_loop from the parent after
540 * setting up file descriptors, controlling tty, updating wtmp, utmp,
541 * lastlog, and other such operations.
544 do_exec_pty(Session *s, const char *command)
546 int fdout, ptyfd, ttyfd, ptymaster;
550 fatal("do_exec_pty: no session");
555 if (options.use_pam) {
556 do_pam_set_tty(s->tty);
562 /* Fork the child. */
563 if ((pid = fork()) == 0) {
566 /* Child. Reinitialize the log because the pid has changed. */
567 log_init(__progname, options.log_level, options.log_facility, log_stderr);
568 /* Close the master side of the pseudo tty. */
571 /* Make the pseudo tty our controlling tty. */
572 pty_make_controlling_tty(&ttyfd, s->tty);
574 /* Redirect stdin/stdout/stderr from the pseudo tty. */
575 if (dup2(ttyfd, 0) < 0)
576 error("dup2 stdin: %s", strerror(errno));
577 if (dup2(ttyfd, 1) < 0)
578 error("dup2 stdout: %s", strerror(errno));
579 if (dup2(ttyfd, 2) < 0)
580 error("dup2 stderr: %s", strerror(errno));
582 /* Close the extra descriptor for the pseudo tty. */
585 /* record login, etc. similar to login(1) */
587 if (!(options.use_login && command == NULL)) {
589 cray_init_job(s->pw); /* set up cray jid and tmpdir */
591 do_login(s, command);
593 # ifdef LOGIN_NEEDS_UTMPX
599 /* Do common processing for the child, such as execing the command. */
600 do_child(s, command);
604 signal(WJSIGNAL, cray_job_termination_handler);
608 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
611 packet_disconnect("fork failed: %.100s", strerror(errno));
614 /* Parent. Close the slave side of the pseudo tty. */
618 * Create another descriptor of the pty master side for use as the
619 * standard input. We could use the original descriptor, but this
620 * simplifies code in server_loop. The descriptor is bidirectional.
624 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
626 /* we keep a reference to the pty master */
627 ptymaster = dup(ptyfd);
629 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
630 s->ptymaster = ptymaster;
632 /* Enter interactive session. */
633 packet_set_interactive(1);
635 session_set_fds(s, ptyfd, fdout, -1);
637 server_loop(pid, ptyfd, fdout, -1);
638 /* server_loop _has_ closed ptyfd and fdout. */
642 #ifdef LOGIN_NEEDS_UTMPX
644 do_pre_login(Session *s)
647 struct sockaddr_storage from;
648 pid_t pid = getpid();
651 * Get IP address of client. If the connection is not a socket, let
652 * the address be 0.0.0.0.
654 memset(&from, 0, sizeof(from));
655 fromlen = sizeof(from);
656 if (packet_connection_is_on_socket()) {
657 if (getpeername(packet_get_connection_in(),
658 (struct sockaddr *) & from, &fromlen) < 0) {
659 debug("getpeername: %.100s", strerror(errno));
664 record_utmp_only(pid, s->tty, s->pw->pw_name,
665 get_remote_name_or_ip(utmp_len, options.use_dns),
666 (struct sockaddr *)&from, fromlen);
671 * This is called to fork and execute a command. If another command is
672 * to be forced, execute that instead.
675 do_exec(Session *s, const char *command)
677 if (forced_command) {
678 original_command = command;
679 command = forced_command;
680 debug("Forced command '%.900s'", command);
683 #if defined(SESSION_HOOKS)
684 if (options.session_hooks_allow &&
685 (options.session_hooks_startup_cmd ||
686 options.session_hooks_shutdown_cmd))
694 "/tmp/ssh_env_%d%d%d",
698 } while (stat(env_file, &st)==0);
699 s->authctxt->session_env_file = strdup(env_file);
703 #ifdef SSH_AUDIT_EVENTS
705 PRIVSEP(audit_run_command(command));
706 else if (s->ttyfd == -1) {
707 char *shell = s->pw->pw_shell;
709 if (shell[0] == '\0') /* empty shell means /bin/sh */
711 PRIVSEP(audit_run_command(shell));
716 do_exec_pty(s, command);
718 do_exec_no_pty(s, command);
720 original_command = NULL;
723 * Clear loginmsg: it's the child's responsibility to display
724 * it to the user, otherwise multiple sessions may accumulate
725 * multiple copies of the login messages.
727 buffer_clear(&loginmsg);
730 /* administrative, login(1)-like work */
732 do_login(Session *s, const char *command)
735 struct sockaddr_storage from;
736 struct passwd * pw = s->pw;
737 pid_t pid = getpid();
740 * Get IP address of client. If the connection is not a socket, let
741 * the address be 0.0.0.0.
743 memset(&from, 0, sizeof(from));
744 fromlen = sizeof(from);
745 if (packet_connection_is_on_socket()) {
746 if (getpeername(packet_get_connection_in(),
747 (struct sockaddr *) & from, &fromlen) < 0) {
748 debug("getpeername: %.100s", strerror(errno));
753 /* Record that there was a login on that tty from the remote host. */
755 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
756 get_remote_name_or_ip(utmp_len,
758 (struct sockaddr *)&from, fromlen);
762 * If password change is needed, do it now.
763 * This needs to occur before the ~/.hushlogin check.
765 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
768 s->authctxt->force_pwchange = 0;
769 /* XXX - signal [net] parent to enable forwardings */
773 if (check_quietlogin(s, command))
782 * Display the message of the day.
790 if (options.print_motd) {
791 #ifdef HAVE_LOGIN_CAP
792 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
795 f = fopen("/etc/motd", "r");
798 while (fgets(buf, sizeof(buf), f))
807 * Check for quiet login, either .hushlogin or command given.
810 check_quietlogin(Session *s, const char *command)
813 struct passwd *pw = s->pw;
816 /* Return 1 if .hushlogin exists or a command given. */
819 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
820 #ifdef HAVE_LOGIN_CAP
821 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
824 if (stat(buf, &st) >= 0)
831 * Sets the value of the given variable in the environment. If the variable
832 * already exists, its value is overriden.
835 child_set_env(char ***envp, u_int *envsizep, const char *name,
843 * If we're passed an uninitialized list, allocate a single null
844 * entry before continuing.
846 if (*envp == NULL && *envsizep == 0) {
847 *envp = xmalloc(sizeof(char *));
853 * Find the slot where the value should be stored. If the variable
854 * already exists, we reuse the slot; otherwise we append a new slot
855 * at the end of the array, expanding if necessary.
858 namelen = strlen(name);
859 for (i = 0; env[i]; i++)
860 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
863 /* Reuse the slot. */
866 /* New variable. Expand if necessary. */
868 if (i >= envsize - 1) {
870 fatal("child_set_env: too many env vars");
872 env = (*envp) = xrealloc(env, envsize * sizeof(char *));
875 /* Need to set the NULL pointer at end of array beyond the new slot. */
879 /* Allocate space and format the variable in the appropriate slot. */
880 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
881 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
885 * Reads environment variables from the given file and adds/overrides them
886 * into the environment. If the file does not exist, this does nothing.
887 * Otherwise, it must consist of empty lines, comments (line starts with '#')
888 * and assignments of the form name=value. No other forms are allowed.
891 read_environment_file(char ***env, u_int *envsize,
892 const char *filename)
899 f = fopen(filename, "r");
903 while (fgets(buf, sizeof(buf), f)) {
905 fatal("Too many lines in environment file %s", filename);
906 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
908 if (!*cp || *cp == '#' || *cp == '\n')
910 if (strchr(cp, '\n'))
911 *strchr(cp, '\n') = '\0';
912 value = strchr(cp, '=');
914 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
919 * Replace the equals sign by nul, and advance value to
924 child_set_env(env, envsize, cp, value);
930 #define SSH_SESSION_ENV_FILE "SSH_SESSION_ENV_FILE"
932 typedef enum { no_op, execute, clear_env, restore_env,
933 read_env, save_or_rm_env } session_action_t;
935 static session_action_t action_order[2][5] = {
936 { clear_env, read_env, execute, save_or_rm_env, restore_env }, /*shutdown*/
937 { execute, read_env, save_or_rm_env, no_op, no_op } /*startup */
941 void execute_session_hook(char* prog, Authctxt *authctxt,
942 int startup, int save)
944 extern char **environ;
947 char **saved_env, **tmpenv;
948 char *env_file = authctxt->session_env_file;
953 switch (action_order[startup][i])
966 authctxt->pw->pw_shell,
969 debug("executing session hook: [%s]", buf);
970 setenv(SSH_SESSION_ENV_FILE, env_file, /* overwrite = */ 1);
972 /* flusing is recommended in the popen(3) man page, to avoid
973 intermingling of output */
976 if ((fp=popen(buf, "w")) == NULL)
978 perror("Unable to run session hook");
982 debug2("session hook executed, status=%d", status);
983 unsetenv(SSH_SESSION_ENV_FILE);
989 tmpenv = (char**) malloc(sizeof(char*));
1000 if (status==0 && stat(env_file, &st)==0)
1004 debug("reading environment from %s", env_file);
1005 while (environ[envsize++]) ;
1006 read_environment_file(&environ, &envsize, env_file);
1010 case save_or_rm_env:
1011 if (status==0 && save)
1016 debug2("saving environment to %s", env_file);
1017 if ((fp = fopen(env_file, "w")) == NULL) /* hmm: file perms? */
1019 perror("Unable to save session hook info");
1021 while (environ[envcount])
1023 fprintf(fp, "%s\n", environ[envcount++]);
1028 else if (stat(env_file, &st)==0)
1030 debug2("removing environment file %s", env_file);
1040 #ifdef HAVE_ETC_DEFAULT_LOGIN
1042 * Return named variable from specified environment, or NULL if not present.
1045 child_get_env(char **env, const char *name)
1051 for (i=0; env[i] != NULL; i++)
1052 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
1053 return(env[i] + len + 1);
1058 * Read /etc/default/login.
1059 * We pick up the PATH (or SUPATH for root) and UMASK.
1062 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
1064 char **tmpenv = NULL, *var;
1065 u_int i, tmpenvsize = 0;
1069 * We don't want to copy the whole file to the child's environment,
1070 * so we use a temporary environment and copy the variables we're
1073 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
1079 var = child_get_env(tmpenv, "SUPATH");
1081 var = child_get_env(tmpenv, "PATH");
1083 child_set_env(env, envsize, "PATH", var);
1085 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
1086 if (sscanf(var, "%5lo", &mask) == 1)
1087 umask((mode_t)mask);
1089 for (i = 0; tmpenv[i] != NULL; i++)
1093 #endif /* HAVE_ETC_DEFAULT_LOGIN */
1096 copy_environment(char **source, char ***env, u_int *envsize)
1098 char *var_name, *var_val;
1104 for(i = 0; source[i] != NULL; i++) {
1105 var_name = xstrdup(source[i]);
1106 if ((var_val = strstr(var_name, "=")) == NULL) {
1112 debug3("Copy environment: %s=%s", var_name, var_val);
1113 child_set_env(env, envsize, var_name, var_val);
1120 do_setup_env(Session *s, const char *shell)
1124 char **env, *laddr, *path = NULL;
1125 struct passwd *pw = s->pw;
1127 /* Initialize the environment. */
1129 env = xmalloc(envsize * sizeof(char *));
1134 * The Windows environment contains some setting which are
1135 * important for a running system. They must not be dropped.
1140 p = fetch_windows_environment();
1141 copy_environment(p, &env, &envsize);
1142 free_windows_environment(p);
1147 /* Allow any GSSAPI methods that we've used to alter
1148 * the childs environment as they see fit
1150 ssh_gssapi_do_child(&env, &envsize);
1153 if (!options.use_login) {
1154 /* Set basic environment. */
1155 for (i = 0; i < s->num_env; i++)
1156 child_set_env(&env, &envsize, s->env[i].name,
1159 child_set_env(&env, &envsize, "USER", pw->pw_name);
1160 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1162 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1164 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1165 #ifdef HAVE_LOGIN_CAP
1166 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1167 child_set_env(&env, &envsize, "PATH",
1168 _PATH_STDPATH_WITH_SCP);
1170 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1171 #else /* HAVE_LOGIN_CAP */
1172 # ifndef HAVE_CYGWIN
1174 * There's no standard path on Windows. The path contains
1175 * important components pointing to the system directories,
1176 * needed for loading shared libraries. So the path better
1177 * remains intact here.
1179 # ifdef HAVE_ETC_DEFAULT_LOGIN
1180 read_etc_default_login(&env, &envsize, pw->pw_uid);
1181 path = child_get_env(env, "PATH");
1182 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1183 if (path == NULL || *path == '\0') {
1184 child_set_env(&env, &envsize, "PATH",
1185 s->pw->pw_uid == 0 ?
1186 SUPERUSER_PATH : _PATH_STDPATH_WITH_SCP);
1188 # endif /* HAVE_CYGWIN */
1189 #endif /* HAVE_LOGIN_CAP */
1191 snprintf(buf, sizeof buf, "%.200s/%.50s",
1192 _PATH_MAILDIR, pw->pw_name);
1193 child_set_env(&env, &envsize, "MAIL", buf);
1195 /* Normal systems set SHELL by default. */
1196 child_set_env(&env, &envsize, "SHELL", shell);
1199 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1201 #ifdef GSI /* GSI shared libs typically installed in non-system locations. */
1205 if ((cp = getenv("LD_LIBRARY_PATH")) != NULL)
1206 child_set_env(&env, &envsize, "LD_LIBRARY_PATH", cp);
1207 if ((cp = getenv("LIBPATH")) != NULL)
1208 child_set_env(&env, &envsize, "LIBPATH", cp);
1209 if ((cp = getenv("SHLIB_PATH")) != NULL)
1210 child_set_env(&env, &envsize, "SHLIB_PATH", cp);
1211 if ((cp = getenv("LD_LIBRARYN32_PATH")) != NULL)
1212 child_set_env(&env, &envsize, "LD_LIBRARYN32_PATH",cp);
1213 if ((cp = getenv("LD_LIBRARY64_PATH")) != NULL)
1214 child_set_env(&env, &envsize, "LD_LIBRARY64_PATH",cp);
1215 if ((cp = getenv("GLOBUS_LOCATION")) != NULL)
1216 child_set_env(&env, &envsize, "GLOBUS_LOCATION",cp);
1220 /* Set custom environment options from RSA authentication. */
1221 if (!options.use_login) {
1222 while (custom_environment) {
1223 struct envstring *ce = custom_environment;
1226 for (i = 0; str[i] != '=' && str[i]; i++)
1228 if (str[i] == '=') {
1230 child_set_env(&env, &envsize, str, str + i + 1);
1232 custom_environment = ce->next;
1238 /* SSH_CLIENT deprecated */
1239 snprintf(buf, sizeof buf, "%.50s %d %d",
1240 get_remote_ipaddr(), get_remote_port(), get_local_port());
1241 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1243 laddr = get_local_ipaddr(packet_get_connection_in());
1244 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1245 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1247 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1250 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1252 child_set_env(&env, &envsize, "TERM", s->term);
1254 child_set_env(&env, &envsize, "DISPLAY", s->display);
1255 if (original_command)
1256 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1260 if (cray_tmpdir[0] != '\0')
1261 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1262 #endif /* _UNICOS */
1265 * Since we clear KRB5CCNAME at startup, if it's set now then it
1266 * must have been set by a native authentication method (eg AIX or
1267 * SIA), so copy it to the child.
1272 if ((cp = getenv("KRB5CCNAME")) != NULL)
1273 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1280 if ((cp = getenv("AUTHSTATE")) != NULL)
1281 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1282 read_environment_file(&env, &envsize, "/etc/environment");
1286 if (s->authctxt->krb5_ccname)
1287 child_set_env(&env, &envsize, "KRB5CCNAME",
1288 s->authctxt->krb5_ccname);
1292 * Pull in any environment variables that may have
1295 if (options.use_pam) {
1298 p = fetch_pam_child_environment();
1299 copy_environment(p, &env, &envsize);
1300 free_pam_environment(p);
1302 p = fetch_pam_environment();
1303 copy_environment(p, &env, &envsize);
1304 free_pam_environment(p);
1306 #endif /* USE_PAM */
1308 if (auth_sock_name != NULL)
1309 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1312 /* read $HOME/.ssh/environment. */
1313 if (options.permit_user_env && !options.use_login) {
1314 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1315 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1316 read_environment_file(&env, &envsize, buf);
1319 /* dump the environment */
1320 fprintf(stderr, "Environment:\n");
1321 for (i = 0; env[i]; i++)
1322 fprintf(stderr, " %.200s\n", env[i]);
1328 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1329 * first in this order).
1332 do_rc_files(Session *s, const char *shell)
1340 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1342 /* ignore _PATH_SSH_USER_RC for subsystems */
1343 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1344 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1345 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1347 fprintf(stderr, "Running %s\n", cmd);
1348 f = popen(cmd, "w");
1351 fprintf(f, "%s %s\n", s->auth_proto,
1355 fprintf(stderr, "Could not run %s\n",
1357 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1358 snprintf(cmd, sizeof cmd, "%s %s", _PATH_BSHELL,
1359 _PATH_SSH_SYSTEM_RC);
1361 fprintf(stderr, "Running %s\n", cmd);
1362 f = popen(cmd, "w");
1365 fprintf(f, "%s %s\n", s->auth_proto,
1369 fprintf(stderr, "Could not run %s\n",
1370 _PATH_SSH_SYSTEM_RC);
1371 } else if (do_xauth && options.xauth_location != NULL) {
1372 /* Add authority data to .Xauthority if appropriate. */
1375 "Running %.500s remove %.100s\n",
1376 options.xauth_location, s->auth_display);
1378 "%.500s add %.100s %.100s %.100s\n",
1379 options.xauth_location, s->auth_display,
1380 s->auth_proto, s->auth_data);
1382 snprintf(cmd, sizeof cmd, "%s -q -",
1383 options.xauth_location);
1384 f = popen(cmd, "w");
1386 fprintf(f, "remove %s\n",
1388 fprintf(f, "add %s %s %s\n",
1389 s->auth_display, s->auth_proto,
1393 fprintf(stderr, "Could not run %s\n",
1400 do_nologin(struct passwd *pw)
1405 #ifdef HAVE_LOGIN_CAP
1406 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1407 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1408 _PATH_NOLOGIN), "r");
1411 f = fopen(_PATH_NOLOGIN, "r");
1414 /* /etc/nologin exists. Print its contents and exit. */
1415 logit("User %.100s not allowed because %s exists",
1416 pw->pw_name, _PATH_NOLOGIN);
1417 while (fgets(buf, sizeof(buf), f))
1425 /* Set login name, uid, gid, and groups. */
1427 do_setusercontext(struct passwd *pw)
1430 if (getuid() == 0 || geteuid() == 0)
1431 #endif /* HAVE_CYGWIN */
1434 #ifdef HAVE_SETPCRED
1435 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1436 fatal("Failed to set process credentials");
1437 #endif /* HAVE_SETPCRED */
1438 #ifdef HAVE_LOGIN_CAP
1443 if (options.gss_authentication) {
1444 temporarily_use_uid(pw);
1445 ssh_gssapi_storecreds();
1450 if (options.use_pam) {
1454 # endif /* USE_PAM */
1455 if (setusercontext(lc, pw, pw->pw_uid,
1456 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1457 perror("unable to set user context");
1461 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1462 /* Sets login uid for accounting */
1463 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1464 error("setluid: %s", strerror(errno));
1465 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1467 if (setlogin(pw->pw_name) < 0)
1468 error("setlogin failed: %s", strerror(errno));
1469 if (setgid(pw->pw_gid) < 0) {
1473 /* Initialize the group list. */
1474 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1475 perror("initgroups");
1480 if (options.gss_authentication) {
1481 temporarily_use_uid(pw);
1482 ssh_gssapi_storecreds();
1488 * PAM credentials may take the form of supplementary groups.
1489 * These will have been wiped by the above initgroups() call.
1490 * Reestablish them here.
1492 if (options.use_pam) {
1496 # endif /* USE_PAM */
1497 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1498 irix_setusercontext(pw);
1499 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1503 #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
1504 if (set_id(pw->pw_name) != 0) {
1507 #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
1508 /* Permanently switch to the desired uid. */
1509 permanently_set_uid(pw);
1516 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1517 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1521 do_pwchange(Session *s)
1524 fprintf(stderr, "WARNING: Your password has expired.\n");
1525 if (s->ttyfd != -1) {
1527 "You must change your password now and login again!\n");
1528 #ifdef PASSWD_NEEDS_USERNAME
1529 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1532 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1537 "Password change required but no TTY available.\n");
1543 launch_login(struct passwd *pw, const char *hostname)
1545 /* Launch login(1). */
1547 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1548 #ifdef xxxLOGIN_NEEDS_TERM
1549 (s->term ? s->term : "unknown"),
1550 #endif /* LOGIN_NEEDS_TERM */
1551 #ifdef LOGIN_NO_ENDOPT
1552 "-p", "-f", pw->pw_name, (char *)NULL);
1554 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1557 /* Login couldn't be executed, die. */
1564 child_close_fds(void)
1568 if (packet_get_connection_in() == packet_get_connection_out())
1569 close(packet_get_connection_in());
1571 close(packet_get_connection_in());
1572 close(packet_get_connection_out());
1575 * Close all descriptors related to channels. They will still remain
1576 * open in the parent.
1578 /* XXX better use close-on-exec? -markus */
1579 channel_close_all();
1582 * Close any extra file descriptors. Note that there may still be
1583 * descriptors left by system functions. They will be closed later.
1588 * Close any extra open file descriptors so that we don't have them
1589 * hanging around in clients. Note that we want to do this after
1590 * initgroups, because at least on Solaris 2.3 it leaves file
1593 for (i = 3; i < 64; i++)
1598 * Performs common processing for the child, such as setting up the
1599 * environment, closing extra file descriptors, setting the user and group
1600 * ids, and executing the command or shell.
1603 do_child(Session *s, const char *command)
1605 extern char **environ;
1608 const char *shell, *shell0, *hostname = NULL;
1609 struct passwd *pw = s->pw;
1612 /* Default place to look for aklog. */
1614 #define KPROGDIR AKLOG_PATH
1616 #define KPROGDIR "/usr/bin/aklog"
1617 #endif /* AKLOG_PATH */
1621 #endif /* AFS_KRB5 */
1623 /* remove hostkey from the child's memory */
1624 destroy_sensitive_data();
1626 /* Force a password change */
1627 if (s->authctxt->force_pwchange) {
1628 do_setusercontext(pw);
1634 /* login(1) is only called if we execute the login shell */
1635 if (options.use_login && command != NULL)
1636 options.use_login = 0;
1639 cray_setup(pw->pw_uid, pw->pw_name, command);
1640 #endif /* _UNICOS */
1643 * Login(1) does this as well, and it needs uid 0 for the "-h"
1644 * switch, so we let login(1) to this for us.
1646 if (!options.use_login) {
1648 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1649 if (!check_quietlogin(s, command))
1651 #else /* HAVE_OSF_SIA */
1652 /* When PAM is enabled we rely on it to do the nologin check */
1653 if (!options.use_pam)
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 forwarding 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 if(options.hpn_disabled)
2243 channel_set_fds(s->chanid,
2245 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2247 CHAN_SES_WINDOW_DEFAULT);
2249 channel_set_fds(s->chanid,
2251 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2253 options.hpn_buffer_size);
2257 * Function to perform pty cleanup. Also called if we get aborted abnormally
2258 * (e.g., due to a dropped connection).
2261 session_pty_cleanup2(Session *s)
2264 error("session_pty_cleanup: no session");
2270 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2272 /* Record that the user has logged out. */
2274 record_logout(s->pid, s->tty, s->pw->pw_name);
2276 /* Release the pseudo-tty. */
2278 pty_release(s->tty);
2281 * Close the server side of the socket pairs. We must do this after
2282 * the pty cleanup, so that another process doesn't get this pty
2283 * while we're still cleaning up.
2285 if (close(s->ptymaster) < 0)
2286 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2288 /* unlink pty from session */
2293 session_pty_cleanup(Session *s)
2295 PRIVSEP(session_pty_cleanup2(s));
2301 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2316 return "SIG@openssh.com";
2320 session_close_x11(int id)
2324 if ((c = channel_by_id(id)) == NULL) {
2325 debug("session_close_x11: x11 channel %d missing", id);
2327 /* Detach X11 listener */
2328 debug("session_close_x11: detach x11 channel %d", id);
2329 channel_cancel_cleanup(id);
2330 if (c->ostate != CHAN_OUTPUT_CLOSED)
2336 session_close_single_x11(int id, void *arg)
2341 debug3("session_close_single_x11: channel %d", id);
2342 channel_cancel_cleanup(id);
2343 if ((s = session_by_x11_channel(id)) == NULL)
2344 fatal("session_close_single_x11: no x11 channel %d", id);
2345 for (i = 0; s->x11_chanids[i] != -1; i++) {
2346 debug("session_close_single_x11: session %d: "
2347 "closing channel %d", s->self, s->x11_chanids[i]);
2349 * The channel "id" is already closing, but make sure we
2350 * close all of its siblings.
2352 if (s->x11_chanids[i] != id)
2353 session_close_x11(s->x11_chanids[i]);
2355 xfree(s->x11_chanids);
2356 s->x11_chanids = NULL;
2361 if (s->auth_proto) {
2362 xfree(s->auth_proto);
2363 s->auth_proto = NULL;
2366 xfree(s->auth_data);
2367 s->auth_data = NULL;
2369 if (s->auth_display) {
2370 xfree(s->auth_display);
2371 s->auth_display = NULL;
2376 session_exit_message(Session *s, int status)
2380 if ((c = channel_lookup(s->chanid)) == NULL)
2381 fatal("session_exit_message: session %d: no channel %d",
2382 s->self, s->chanid);
2383 debug("session_exit_message: session %d channel %d pid %ld",
2384 s->self, s->chanid, (long)s->pid);
2386 if (WIFEXITED(status)) {
2387 channel_request_start(s->chanid, "exit-status", 0);
2388 packet_put_int(WEXITSTATUS(status));
2390 } else if (WIFSIGNALED(status)) {
2391 channel_request_start(s->chanid, "exit-signal", 0);
2392 packet_put_cstring(sig2name(WTERMSIG(status)));
2394 packet_put_char(WCOREDUMP(status));
2395 #else /* WCOREDUMP */
2397 #endif /* WCOREDUMP */
2398 packet_put_cstring("");
2399 packet_put_cstring("");
2402 /* Some weird exit cause. Just exit. */
2403 packet_disconnect("wait returned status %04x.", status);
2406 /* disconnect channel */
2407 debug("session_exit_message: release channel %d", s->chanid);
2410 * Adjust cleanup callback attachment to send close messages when
2411 * the channel gets EOF. The session will be then be closed
2412 * by session_close_by_channel when the childs close their fds.
2414 channel_register_cleanup(c->self, session_close_by_channel, 1);
2417 * emulate a write failure with 'chan_write_failed', nobody will be
2418 * interested in data we write.
2419 * Note that we must not call 'chan_read_failed', since there could
2420 * be some more data waiting in the pipe.
2422 if (c->ostate != CHAN_OUTPUT_CLOSED)
2423 chan_write_failed(c);
2427 session_close(Session *s)
2431 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2433 session_pty_cleanup(s);
2439 xfree(s->x11_chanids);
2440 if (s->auth_display)
2441 xfree(s->auth_display);
2443 xfree(s->auth_data);
2445 xfree(s->auth_proto);
2447 for (i = 0; i < s->num_env; i++) {
2448 xfree(s->env[i].name);
2449 xfree(s->env[i].val);
2453 session_proctitle(s);
2457 session_close_by_pid(pid_t pid, int status)
2459 Session *s = session_by_pid(pid);
2461 debug("session_close_by_pid: no session for pid %ld",
2465 if (s->chanid != -1)
2466 session_exit_message(s, status);
2468 session_pty_cleanup(s);
2473 * this is called when a channel dies before
2474 * the session 'child' itself dies
2477 session_close_by_channel(int id, void *arg)
2479 Session *s = session_by_channel(id);
2483 debug("session_close_by_channel: no session for id %d", id);
2486 debug("session_close_by_channel: channel %d child %ld",
2489 debug("session_close_by_channel: channel %d: has child", id);
2491 * delay detach of session, but release pty, since
2492 * the fd's to the child are already closed
2495 session_pty_cleanup(s);
2498 /* detach by removing callback */
2499 channel_cancel_cleanup(s->chanid);
2501 /* Close any X11 listeners associated with this session */
2502 if (s->x11_chanids != NULL) {
2503 for (i = 0; s->x11_chanids[i] != -1; i++) {
2504 session_close_x11(s->x11_chanids[i]);
2505 s->x11_chanids[i] = -1;
2514 session_destroy_all(void (*closefunc)(Session *))
2517 for (i = 0; i < MAX_SESSIONS; i++) {
2518 Session *s = &sessions[i];
2520 if (closefunc != NULL)
2529 session_tty_list(void)
2531 static char buf[1024];
2536 for (i = 0; i < MAX_SESSIONS; i++) {
2537 Session *s = &sessions[i];
2538 if (s->used && s->ttyfd != -1) {
2540 if (strncmp(s->tty, "/dev/", 5) != 0) {
2541 cp = strrchr(s->tty, '/');
2542 cp = (cp == NULL) ? s->tty : cp + 1;
2547 strlcat(buf, ",", sizeof buf);
2548 strlcat(buf, cp, sizeof buf);
2552 strlcpy(buf, "notty", sizeof buf);
2557 session_proctitle(Session *s)
2560 error("no user for session %d", s->self);
2562 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2566 session_setup_x11fwd(Session *s)
2569 char display[512], auth_display[512];
2570 char hostname[MAXHOSTNAMELEN];
2573 if (no_x11_forwarding_flag) {
2574 packet_send_debug("X11 forwarding disabled in user configuration file.");
2577 if (!options.x11_forwarding) {
2578 debug("X11 forwarding disabled in server configuration file.");
2581 if (!options.xauth_location ||
2582 (stat(options.xauth_location, &st) == -1)) {
2583 packet_send_debug("No xauth program; cannot forward with spoofing.");
2586 if (options.use_login) {
2587 packet_send_debug("X11 forwarding disabled; "
2588 "not compatible with UseLogin=yes.");
2591 if (s->display != NULL) {
2592 debug("X11 display already set.");
2595 if (x11_create_display_inet(options.x11_display_offset,
2596 options.x11_use_localhost, s->single_connection,
2597 &s->display_number, &s->x11_chanids,
2598 options.hpn_disabled, options.hpn_buffer_size) == -1) {
2599 debug("x11_create_display_inet failed.");
2602 for (i = 0; s->x11_chanids[i] != -1; i++) {
2603 channel_register_cleanup(s->x11_chanids[i],
2604 session_close_single_x11, 0);
2607 /* Set up a suitable value for the DISPLAY variable. */
2608 if (gethostname(hostname, sizeof(hostname)) < 0)
2609 fatal("gethostname: %.100s", strerror(errno));
2611 * auth_display must be used as the displayname when the
2612 * authorization entry is added with xauth(1). This will be
2613 * different than the DISPLAY string for localhost displays.
2615 if (options.x11_use_localhost) {
2616 snprintf(display, sizeof display, "localhost:%u.%u",
2617 s->display_number, s->screen);
2618 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2619 s->display_number, s->screen);
2620 s->display = xstrdup(display);
2621 s->auth_display = xstrdup(auth_display);
2623 #ifdef IPADDR_IN_DISPLAY
2625 struct in_addr my_addr;
2627 he = gethostbyname(hostname);
2629 error("Can't get IP address for X11 DISPLAY.");
2630 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2633 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2634 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2635 s->display_number, s->screen);
2637 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2638 s->display_number, s->screen);
2640 s->display = xstrdup(display);
2641 s->auth_display = xstrdup(display);
2648 do_authenticated2(Authctxt *authctxt)
2650 server_loop2(authctxt);
2654 do_cleanup(Authctxt *authctxt)
2656 static int called = 0;
2658 debug("do_cleanup");
2660 /* no cleanup if we're in the child for login shell */
2664 /* avoid double cleanup */
2669 if (authctxt == NULL)
2672 if (options.kerberos_ticket_cleanup &&
2674 krb5_cleanup_proc(authctxt);
2678 if (compat20 && options.gss_cleanup_creds)
2679 ssh_gssapi_cleanup_creds();
2683 if (options.use_pam) {
2685 sshpam_thread_cleanup();
2689 /* remove agent socket */
2690 auth_sock_cleanup_proc(authctxt->pw);
2693 * Cleanup ptys/utmp only if privsep is disabled,
2694 * or if running in monitor.
2696 if (!use_privsep || mm_is_monitor())
2697 session_destroy_all(session_pty_cleanup2);