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 1.185 2005/07/17 07:17:55 djm Exp $");
51 #include "auth-options.h"
52 #include "pathnames.h"
56 #include "serverloop.h"
59 #include "monitor_wrap.h"
61 #if defined(KRB5) && defined(USE_AFS)
71 Session *session_new(void);
72 void session_set_fds(Session *, int, int, int);
73 void session_pty_cleanup(Session *);
74 void session_proctitle(Session *);
75 int session_setup_x11fwd(Session *);
76 void do_exec_pty(Session *, const char *);
77 void do_exec_no_pty(Session *, const char *);
78 void do_exec(Session *, const char *);
79 void do_login(Session *, const char *);
80 #ifdef LOGIN_NEEDS_UTMPX
81 static void do_pre_login(Session *s);
83 void do_child(Session *, const char *);
85 int check_quietlogin(Session *, const char *);
87 static void do_authenticated1(Authctxt *);
88 static void do_authenticated2(Authctxt *);
90 static int session_pty_req(Session *);
93 extern ServerOptions options;
94 extern char *__progname;
95 extern int log_stderr;
96 extern int debug_flag;
97 extern u_int utmp_len;
98 extern int startup_pipe;
99 extern void destroy_sensitive_data(void);
100 extern Buffer loginmsg;
102 /* original command from peer. */
103 const char *original_command = NULL;
106 #define MAX_SESSIONS 10
107 Session sessions[MAX_SESSIONS];
109 #ifdef HAVE_LOGIN_CAP
113 static int is_child = 0;
115 /* Name and directory of socket for authentication agent forwarding. */
116 static char *auth_sock_name = NULL;
117 static char *auth_sock_dir = NULL;
119 /* removes the agent forwarding socket */
122 auth_sock_cleanup_proc(struct passwd *pw)
124 if (auth_sock_name != NULL) {
125 temporarily_use_uid(pw);
126 unlink(auth_sock_name);
127 rmdir(auth_sock_dir);
128 auth_sock_name = NULL;
134 auth_input_request_forwarding(struct passwd * pw)
138 struct sockaddr_un sunaddr;
140 if (auth_sock_name != NULL) {
141 error("authentication forwarding requested twice.");
145 /* Temporarily drop privileged uid for mkdir/bind. */
146 temporarily_use_uid(pw);
148 /* Allocate a buffer for the socket name, and format the name. */
149 auth_sock_name = xmalloc(MAXPATHLEN);
150 auth_sock_dir = xmalloc(MAXPATHLEN);
151 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
153 /* Create private directory for socket */
154 if (mkdtemp(auth_sock_dir) == NULL) {
155 packet_send_debug("Agent forwarding disabled: "
156 "mkdtemp() failed: %.100s", strerror(errno));
158 xfree(auth_sock_name);
159 xfree(auth_sock_dir);
160 auth_sock_name = NULL;
161 auth_sock_dir = NULL;
164 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
165 auth_sock_dir, (long) getpid());
167 /* Create the socket. */
168 sock = socket(AF_UNIX, SOCK_STREAM, 0);
170 packet_disconnect("socket: %.100s", strerror(errno));
172 /* Bind it to the name. */
173 memset(&sunaddr, 0, sizeof(sunaddr));
174 sunaddr.sun_family = AF_UNIX;
175 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
177 if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
178 packet_disconnect("bind: %.100s", strerror(errno));
180 /* Restore the privileged uid. */
183 /* Start listening on the socket. */
184 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
185 packet_disconnect("listen: %.100s", strerror(errno));
187 /* Allocate a channel for the authentication agent socket. */
188 nc = channel_new("auth socket",
189 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
190 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
191 0, "auth socket", 1);
192 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
197 display_loginmsg(void)
199 if (buffer_len(&loginmsg) > 0) {
200 buffer_append(&loginmsg, "\0", 1);
201 printf("%s", (char *)buffer_ptr(&loginmsg));
202 buffer_clear(&loginmsg);
207 do_authenticated(Authctxt *authctxt)
209 setproctitle("%s", authctxt->pw->pw_name);
212 * Cancel the alarm we set to limit the time taken for
216 if (startup_pipe != -1) {
220 /* setup the channel layer */
221 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
222 channel_permit_all_opens();
225 do_authenticated2(authctxt);
227 do_authenticated1(authctxt);
229 do_cleanup(authctxt);
233 * Prepares for an interactive session. This is called after the user has
234 * been successfully authenticated. During this message exchange, pseudo
235 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
236 * are requested, etc.
239 do_authenticated1(Authctxt *authctxt)
243 int success, type, screen_flag;
244 int enable_compression_after_reply = 0;
245 u_int proto_len, data_len, dlen, compression_level = 0;
249 error("no more sessions");
252 s->authctxt = authctxt;
253 s->pw = authctxt->pw;
256 * We stay in this loop until the client requests to execute a shell
262 /* Get a packet from the client. */
263 type = packet_read();
265 /* Process the packet. */
267 case SSH_CMSG_REQUEST_COMPRESSION:
268 compression_level = packet_get_int();
270 if (compression_level < 1 || compression_level > 9) {
271 packet_send_debug("Received invalid compression level %d.",
275 if (!options.compression) {
276 debug2("compression disabled");
279 /* Enable compression after we have responded with SUCCESS. */
280 enable_compression_after_reply = 1;
284 case SSH_CMSG_REQUEST_PTY:
285 success = session_pty_req(s);
288 case SSH_CMSG_X11_REQUEST_FORWARDING:
289 s->auth_proto = packet_get_string(&proto_len);
290 s->auth_data = packet_get_string(&data_len);
292 screen_flag = packet_get_protocol_flags() &
293 SSH_PROTOFLAG_SCREEN_NUMBER;
294 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
296 if (packet_remaining() == 4) {
298 debug2("Buggy client: "
299 "X11 screen flag missing");
300 s->screen = packet_get_int();
305 success = session_setup_x11fwd(s);
307 xfree(s->auth_proto);
309 s->auth_proto = NULL;
314 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
315 if (no_agent_forwarding_flag || compat13) {
316 debug("Authentication agent forwarding not permitted for this authentication.");
319 debug("Received authentication agent forwarding request.");
320 success = auth_input_request_forwarding(s->pw);
323 case SSH_CMSG_PORT_FORWARD_REQUEST:
324 if (no_port_forwarding_flag) {
325 debug("Port forwarding not permitted for this authentication.");
328 if (!options.allow_tcp_forwarding) {
329 debug("Port forwarding not permitted.");
332 debug("Received TCP/IP port forwarding request.");
333 channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
337 case SSH_CMSG_MAX_PACKET_SIZE:
338 if (packet_set_maxsize(packet_get_int()) > 0)
342 case SSH_CMSG_EXEC_SHELL:
343 case SSH_CMSG_EXEC_CMD:
344 if (type == SSH_CMSG_EXEC_CMD) {
345 command = packet_get_string(&dlen);
346 debug("Exec command '%.500s'", command);
358 * Any unknown messages in this phase are ignored,
359 * and a failure message is returned.
361 logit("Unknown packet type received after authentication: %d", type);
363 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
367 /* Enable compression now that we have replied if appropriate. */
368 if (enable_compression_after_reply) {
369 enable_compression_after_reply = 0;
370 packet_start_compression(compression_level);
376 * This is called to fork and execute a command when we have no tty. This
377 * will call do_child from the child, and server_loop from the parent after
378 * setting up file descriptors and such.
381 do_exec_no_pty(Session *s, const char *command)
386 int pin[2], pout[2], perr[2];
387 /* Allocate pipes for communicating with the program. */
388 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
389 packet_disconnect("Could not create pipes: %.100s",
391 #else /* USE_PIPES */
392 int inout[2], err[2];
393 /* Uses socket pairs to communicate with the program. */
394 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
395 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
396 packet_disconnect("Could not create socket pairs: %.100s",
398 #endif /* USE_PIPES */
400 fatal("do_exec_no_pty: no session");
402 session_proctitle(s);
405 if (options.use_pam && !use_privsep)
409 /* Fork the child. */
410 if ((pid = fork()) == 0) {
413 /* Child. Reinitialize the log since the pid has changed. */
414 log_init(__progname, options.log_level, options.log_facility, log_stderr);
417 * Create a new session and process group since the 4.4BSD
418 * setlogin() affects the entire process group.
421 error("setsid failed: %.100s", strerror(errno));
425 * Redirect stdin. We close the parent side of the socket
426 * pair, and make the child side the standard input.
429 if (dup2(pin[0], 0) < 0)
430 perror("dup2 stdin");
433 /* Redirect stdout. */
435 if (dup2(pout[1], 1) < 0)
436 perror("dup2 stdout");
439 /* Redirect stderr. */
441 if (dup2(perr[1], 2) < 0)
442 perror("dup2 stderr");
444 #else /* USE_PIPES */
446 * Redirect stdin, stdout, and stderr. Stdin and stdout will
447 * use the same socket, as some programs (particularly rdist)
448 * seem to depend on it.
452 if (dup2(inout[0], 0) < 0) /* stdin */
453 perror("dup2 stdin");
454 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
455 perror("dup2 stdout");
456 if (dup2(err[0], 2) < 0) /* stderr */
457 perror("dup2 stderr");
458 #endif /* USE_PIPES */
461 cray_init_job(s->pw); /* set up cray jid and tmpdir */
464 /* Do processing for the child (exec command etc). */
465 do_child(s, command);
469 signal(WJSIGNAL, cray_job_termination_handler);
473 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
476 packet_disconnect("fork failed: %.100s", strerror(errno));
478 /* Set interactive/non-interactive mode. */
479 packet_set_interactive(s->display != NULL);
481 /* We are the parent. Close the child sides of the pipes. */
487 if (s->is_subsystem) {
491 session_set_fds(s, pin[1], pout[0], perr[0]);
493 /* Enter the interactive session. */
494 server_loop(pid, pin[1], pout[0], perr[0]);
495 /* server_loop has closed pin[1], pout[0], and perr[0]. */
497 #else /* USE_PIPES */
498 /* We are the parent. Close the child sides of the socket pairs. */
503 * Clear loginmsg, since it's the child's responsibility to display
504 * it to the user, otherwise multiple sessions may accumulate
505 * multiple copies of the login messages.
507 buffer_clear(&loginmsg);
510 * Enter the interactive session. Note: server_loop must be able to
511 * handle the case that fdin and fdout are the same.
514 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
516 server_loop(pid, inout[1], inout[1], err[1]);
517 /* server_loop has closed inout[1] and err[1]. */
519 #endif /* USE_PIPES */
523 * This is called to fork and execute a command when we have a tty. This
524 * will call do_child from the child, and server_loop from the parent after
525 * setting up file descriptors, controlling tty, updating wtmp, utmp,
526 * lastlog, and other such operations.
529 do_exec_pty(Session *s, const char *command)
531 int fdout, ptyfd, ttyfd, ptymaster;
535 fatal("do_exec_pty: no session");
540 if (options.use_pam) {
541 do_pam_set_tty(s->tty);
547 /* Fork the child. */
548 if ((pid = fork()) == 0) {
551 /* Child. Reinitialize the log because the pid has changed. */
552 log_init(__progname, options.log_level, options.log_facility, log_stderr);
553 /* Close the master side of the pseudo tty. */
556 /* Make the pseudo tty our controlling tty. */
557 pty_make_controlling_tty(&ttyfd, s->tty);
559 /* Redirect stdin/stdout/stderr from the pseudo tty. */
560 if (dup2(ttyfd, 0) < 0)
561 error("dup2 stdin: %s", strerror(errno));
562 if (dup2(ttyfd, 1) < 0)
563 error("dup2 stdout: %s", strerror(errno));
564 if (dup2(ttyfd, 2) < 0)
565 error("dup2 stderr: %s", strerror(errno));
567 /* Close the extra descriptor for the pseudo tty. */
570 /* record login, etc. similar to login(1) */
572 if (!(options.use_login && command == NULL)) {
574 cray_init_job(s->pw); /* set up cray jid and tmpdir */
576 do_login(s, command);
578 # ifdef LOGIN_NEEDS_UTMPX
584 /* Do common processing for the child, such as execing the command. */
585 do_child(s, command);
589 signal(WJSIGNAL, cray_job_termination_handler);
593 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
596 packet_disconnect("fork failed: %.100s", strerror(errno));
599 /* Parent. Close the slave side of the pseudo tty. */
603 * Create another descriptor of the pty master side for use as the
604 * standard input. We could use the original descriptor, but this
605 * simplifies code in server_loop. The descriptor is bidirectional.
609 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
611 /* we keep a reference to the pty master */
612 ptymaster = dup(ptyfd);
614 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
615 s->ptymaster = ptymaster;
617 /* Enter interactive session. */
618 packet_set_interactive(1);
620 session_set_fds(s, ptyfd, fdout, -1);
622 server_loop(pid, ptyfd, fdout, -1);
623 /* server_loop _has_ closed ptyfd and fdout. */
627 #ifdef LOGIN_NEEDS_UTMPX
629 do_pre_login(Session *s)
632 struct sockaddr_storage from;
633 pid_t pid = getpid();
636 * Get IP address of client. If the connection is not a socket, let
637 * the address be 0.0.0.0.
639 memset(&from, 0, sizeof(from));
640 fromlen = sizeof(from);
641 if (packet_connection_is_on_socket()) {
642 if (getpeername(packet_get_connection_in(),
643 (struct sockaddr *) & from, &fromlen) < 0) {
644 debug("getpeername: %.100s", strerror(errno));
649 record_utmp_only(pid, s->tty, s->pw->pw_name,
650 get_remote_name_or_ip(utmp_len, options.use_dns),
651 (struct sockaddr *)&from, fromlen);
656 * This is called to fork and execute a command. If another command is
657 * to be forced, execute that instead.
660 do_exec(Session *s, const char *command)
662 if (forced_command) {
663 original_command = command;
664 command = forced_command;
665 debug("Forced command '%.900s'", command);
668 #ifdef SSH_AUDIT_EVENTS
670 PRIVSEP(audit_run_command(command));
671 else if (s->ttyfd == -1) {
672 char *shell = s->pw->pw_shell;
674 if (shell[0] == '\0') /* empty shell means /bin/sh */
676 PRIVSEP(audit_run_command(shell));
681 do_exec_pty(s, command);
683 do_exec_no_pty(s, command);
685 original_command = NULL;
688 * Clear loginmsg: it's the child's responsibility to display
689 * it to the user, otherwise multiple sessions may accumulate
690 * multiple copies of the login messages.
692 buffer_clear(&loginmsg);
695 /* administrative, login(1)-like work */
697 do_login(Session *s, const char *command)
700 struct sockaddr_storage from;
701 struct passwd * pw = s->pw;
702 pid_t pid = getpid();
705 * Get IP address of client. If the connection is not a socket, let
706 * the address be 0.0.0.0.
708 memset(&from, 0, sizeof(from));
709 fromlen = sizeof(from);
710 if (packet_connection_is_on_socket()) {
711 if (getpeername(packet_get_connection_in(),
712 (struct sockaddr *) & from, &fromlen) < 0) {
713 debug("getpeername: %.100s", strerror(errno));
718 /* Record that there was a login on that tty from the remote host. */
720 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
721 get_remote_name_or_ip(utmp_len,
723 (struct sockaddr *)&from, fromlen);
727 * If password change is needed, do it now.
728 * This needs to occur before the ~/.hushlogin check.
730 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
733 s->authctxt->force_pwchange = 0;
734 /* XXX - signal [net] parent to enable forwardings */
738 if (check_quietlogin(s, command))
747 * Display the message of the day.
755 if (options.print_motd) {
756 #ifdef HAVE_LOGIN_CAP
757 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
760 f = fopen("/etc/motd", "r");
763 while (fgets(buf, sizeof(buf), f))
772 * Check for quiet login, either .hushlogin or command given.
775 check_quietlogin(Session *s, const char *command)
778 struct passwd *pw = s->pw;
781 /* Return 1 if .hushlogin exists or a command given. */
784 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
785 #ifdef HAVE_LOGIN_CAP
786 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
789 if (stat(buf, &st) >= 0)
796 * Sets the value of the given variable in the environment. If the variable
797 * already exists, its value is overriden.
800 child_set_env(char ***envp, u_int *envsizep, const char *name,
808 * If we're passed an uninitialized list, allocate a single null
809 * entry before continuing.
811 if (*envp == NULL && *envsizep == 0) {
812 *envp = xmalloc(sizeof(char *));
818 * Find the slot where the value should be stored. If the variable
819 * already exists, we reuse the slot; otherwise we append a new slot
820 * at the end of the array, expanding if necessary.
823 namelen = strlen(name);
824 for (i = 0; env[i]; i++)
825 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
828 /* Reuse the slot. */
831 /* New variable. Expand if necessary. */
833 if (i >= envsize - 1) {
835 fatal("child_set_env: too many env vars");
837 env = (*envp) = xrealloc(env, envsize * sizeof(char *));
840 /* Need to set the NULL pointer at end of array beyond the new slot. */
844 /* Allocate space and format the variable in the appropriate slot. */
845 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
846 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
850 * Reads environment variables from the given file and adds/overrides them
851 * into the environment. If the file does not exist, this does nothing.
852 * Otherwise, it must consist of empty lines, comments (line starts with '#')
853 * and assignments of the form name=value. No other forms are allowed.
856 read_environment_file(char ***env, u_int *envsize,
857 const char *filename)
864 f = fopen(filename, "r");
868 while (fgets(buf, sizeof(buf), f)) {
870 fatal("Too many lines in environment file %s", filename);
871 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
873 if (!*cp || *cp == '#' || *cp == '\n')
875 if (strchr(cp, '\n'))
876 *strchr(cp, '\n') = '\0';
877 value = strchr(cp, '=');
879 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
884 * Replace the equals sign by nul, and advance value to
889 child_set_env(env, envsize, cp, value);
894 #ifdef HAVE_ETC_DEFAULT_LOGIN
896 * Return named variable from specified environment, or NULL if not present.
899 child_get_env(char **env, const char *name)
905 for (i=0; env[i] != NULL; i++)
906 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
907 return(env[i] + len + 1);
912 * Read /etc/default/login.
913 * We pick up the PATH (or SUPATH for root) and UMASK.
916 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
918 char **tmpenv = NULL, *var;
919 u_int i, tmpenvsize = 0;
923 * We don't want to copy the whole file to the child's environment,
924 * so we use a temporary environment and copy the variables we're
927 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
933 var = child_get_env(tmpenv, "SUPATH");
935 var = child_get_env(tmpenv, "PATH");
937 child_set_env(env, envsize, "PATH", var);
939 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
940 if (sscanf(var, "%5lo", &mask) == 1)
943 for (i = 0; tmpenv[i] != NULL; i++)
947 #endif /* HAVE_ETC_DEFAULT_LOGIN */
950 copy_environment(char **source, char ***env, u_int *envsize)
952 char *var_name, *var_val;
958 for(i = 0; source[i] != NULL; i++) {
959 var_name = xstrdup(source[i]);
960 if ((var_val = strstr(var_name, "=")) == NULL) {
966 debug3("Copy environment: %s=%s", var_name, var_val);
967 child_set_env(env, envsize, var_name, var_val);
974 do_setup_env(Session *s, const char *shell)
978 char **env, *laddr, *path = NULL;
979 struct passwd *pw = s->pw;
981 /* Initialize the environment. */
983 env = xmalloc(envsize * sizeof(char *));
988 * The Windows environment contains some setting which are
989 * important for a running system. They must not be dropped.
994 p = fetch_windows_environment();
995 copy_environment(p, &env, &envsize);
996 free_windows_environment(p);
1001 /* Allow any GSSAPI methods that we've used to alter
1002 * the childs environment as they see fit
1004 ssh_gssapi_do_child(&env, &envsize);
1007 if (!options.use_login) {
1008 /* Set basic environment. */
1009 for (i = 0; i < s->num_env; i++)
1010 child_set_env(&env, &envsize, s->env[i].name,
1013 child_set_env(&env, &envsize, "USER", pw->pw_name);
1014 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1016 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1018 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1019 #ifdef HAVE_LOGIN_CAP
1020 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1021 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1023 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1024 #else /* HAVE_LOGIN_CAP */
1025 # ifndef HAVE_CYGWIN
1027 * There's no standard path on Windows. The path contains
1028 * important components pointing to the system directories,
1029 * needed for loading shared libraries. So the path better
1030 * remains intact here.
1032 # ifdef HAVE_ETC_DEFAULT_LOGIN
1033 read_etc_default_login(&env, &envsize, pw->pw_uid);
1034 path = child_get_env(env, "PATH");
1035 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1036 if (path == NULL || *path == '\0') {
1037 child_set_env(&env, &envsize, "PATH",
1038 s->pw->pw_uid == 0 ?
1039 SUPERUSER_PATH : _PATH_STDPATH);
1041 # endif /* HAVE_CYGWIN */
1042 #endif /* HAVE_LOGIN_CAP */
1044 snprintf(buf, sizeof buf, "%.200s/%.50s",
1045 _PATH_MAILDIR, pw->pw_name);
1046 child_set_env(&env, &envsize, "MAIL", buf);
1048 /* Normal systems set SHELL by default. */
1049 child_set_env(&env, &envsize, "SHELL", shell);
1052 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1054 /* Set custom environment options from RSA authentication. */
1055 if (!options.use_login) {
1056 while (custom_environment) {
1057 struct envstring *ce = custom_environment;
1060 for (i = 0; str[i] != '=' && str[i]; i++)
1062 if (str[i] == '=') {
1064 child_set_env(&env, &envsize, str, str + i + 1);
1066 custom_environment = ce->next;
1072 /* SSH_CLIENT deprecated */
1073 snprintf(buf, sizeof buf, "%.50s %d %d",
1074 get_remote_ipaddr(), get_remote_port(), get_local_port());
1075 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1077 laddr = get_local_ipaddr(packet_get_connection_in());
1078 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1079 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1081 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1084 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1086 child_set_env(&env, &envsize, "TERM", s->term);
1088 child_set_env(&env, &envsize, "DISPLAY", s->display);
1089 if (original_command)
1090 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1094 if (cray_tmpdir[0] != '\0')
1095 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1096 #endif /* _UNICOS */
1099 * Since we clear KRB5CCNAME at startup, if it's set now then it
1100 * must have been set by a native authentication method (eg AIX or
1101 * SIA), so copy it to the child.
1106 if ((cp = getenv("KRB5CCNAME")) != NULL)
1107 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1114 if ((cp = getenv("AUTHSTATE")) != NULL)
1115 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1116 read_environment_file(&env, &envsize, "/etc/environment");
1120 if (s->authctxt->krb5_ccname)
1121 child_set_env(&env, &envsize, "KRB5CCNAME",
1122 s->authctxt->krb5_ccname);
1126 * Pull in any environment variables that may have
1129 if (options.use_pam) {
1132 p = fetch_pam_child_environment();
1133 copy_environment(p, &env, &envsize);
1134 free_pam_environment(p);
1136 p = fetch_pam_environment();
1137 copy_environment(p, &env, &envsize);
1138 free_pam_environment(p);
1140 #endif /* USE_PAM */
1142 if (auth_sock_name != NULL)
1143 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1146 /* read $HOME/.ssh/environment. */
1147 if (options.permit_user_env && !options.use_login) {
1148 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1149 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1150 read_environment_file(&env, &envsize, buf);
1153 /* dump the environment */
1154 fprintf(stderr, "Environment:\n");
1155 for (i = 0; env[i]; i++)
1156 fprintf(stderr, " %.200s\n", env[i]);
1162 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1163 * first in this order).
1166 do_rc_files(Session *s, const char *shell)
1174 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1176 /* ignore _PATH_SSH_USER_RC for subsystems */
1177 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1178 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1179 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1181 fprintf(stderr, "Running %s\n", cmd);
1182 f = popen(cmd, "w");
1185 fprintf(f, "%s %s\n", s->auth_proto,
1189 fprintf(stderr, "Could not run %s\n",
1191 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1193 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1194 _PATH_SSH_SYSTEM_RC);
1195 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1198 fprintf(f, "%s %s\n", s->auth_proto,
1202 fprintf(stderr, "Could not run %s\n",
1203 _PATH_SSH_SYSTEM_RC);
1204 } else if (do_xauth && options.xauth_location != NULL) {
1205 /* Add authority data to .Xauthority if appropriate. */
1208 "Running %.500s remove %.100s\n",
1209 options.xauth_location, s->auth_display);
1211 "%.500s add %.100s %.100s %.100s\n",
1212 options.xauth_location, s->auth_display,
1213 s->auth_proto, s->auth_data);
1215 snprintf(cmd, sizeof cmd, "%s -q -",
1216 options.xauth_location);
1217 f = popen(cmd, "w");
1219 fprintf(f, "remove %s\n",
1221 fprintf(f, "add %s %s %s\n",
1222 s->auth_display, s->auth_proto,
1226 fprintf(stderr, "Could not run %s\n",
1233 do_nologin(struct passwd *pw)
1238 #ifdef HAVE_LOGIN_CAP
1239 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1240 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1241 _PATH_NOLOGIN), "r");
1244 f = fopen(_PATH_NOLOGIN, "r");
1247 /* /etc/nologin exists. Print its contents and exit. */
1248 logit("User %.100s not allowed because %s exists",
1249 pw->pw_name, _PATH_NOLOGIN);
1250 while (fgets(buf, sizeof(buf), f))
1258 /* Set login name, uid, gid, and groups. */
1260 do_setusercontext(struct passwd *pw)
1263 if (getuid() == 0 || geteuid() == 0)
1264 #endif /* HAVE_CYGWIN */
1267 #ifdef HAVE_SETPCRED
1268 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1269 fatal("Failed to set process credentials");
1270 #endif /* HAVE_SETPCRED */
1271 #ifdef HAVE_LOGIN_CAP
1276 if (options.gss_authentication) {
1277 temporarily_use_uid(pw);
1278 ssh_gssapi_storecreds();
1283 if (options.use_pam) {
1287 # endif /* USE_PAM */
1288 if (setusercontext(lc, pw, pw->pw_uid,
1289 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1290 perror("unable to set user context");
1294 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1295 /* Sets login uid for accounting */
1296 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1297 error("setluid: %s", strerror(errno));
1298 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1300 if (setlogin(pw->pw_name) < 0)
1301 error("setlogin failed: %s", strerror(errno));
1302 if (setgid(pw->pw_gid) < 0) {
1306 /* Initialize the group list. */
1307 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1308 perror("initgroups");
1313 if (options.gss_authentication) {
1314 temporarily_use_uid(pw);
1315 ssh_gssapi_storecreds();
1321 * PAM credentials may take the form of supplementary groups.
1322 * These will have been wiped by the above initgroups() call.
1323 * Reestablish them here.
1325 if (options.use_pam) {
1329 # endif /* USE_PAM */
1330 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1331 irix_setusercontext(pw);
1332 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1336 /* Permanently switch to the desired uid. */
1337 permanently_set_uid(pw);
1344 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1345 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1349 do_pwchange(Session *s)
1352 fprintf(stderr, "WARNING: Your password has expired.\n");
1353 if (s->ttyfd != -1) {
1355 "You must change your password now and login again!\n");
1356 #ifdef PASSWD_NEEDS_USERNAME
1357 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1360 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1365 "Password change required but no TTY available.\n");
1371 launch_login(struct passwd *pw, const char *hostname)
1373 /* Launch login(1). */
1375 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1376 #ifdef xxxLOGIN_NEEDS_TERM
1377 (s->term ? s->term : "unknown"),
1378 #endif /* LOGIN_NEEDS_TERM */
1379 #ifdef LOGIN_NO_ENDOPT
1380 "-p", "-f", pw->pw_name, (char *)NULL);
1382 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1385 /* Login couldn't be executed, die. */
1392 child_close_fds(void)
1396 if (packet_get_connection_in() == packet_get_connection_out())
1397 close(packet_get_connection_in());
1399 close(packet_get_connection_in());
1400 close(packet_get_connection_out());
1403 * Close all descriptors related to channels. They will still remain
1404 * open in the parent.
1406 /* XXX better use close-on-exec? -markus */
1407 channel_close_all();
1410 * Close any extra file descriptors. Note that there may still be
1411 * descriptors left by system functions. They will be closed later.
1416 * Close any extra open file descriptors so that we don\'t have them
1417 * hanging around in clients. Note that we want to do this after
1418 * initgroups, because at least on Solaris 2.3 it leaves file
1421 for (i = 3; i < 64; i++)
1426 * Performs common processing for the child, such as setting up the
1427 * environment, closing extra file descriptors, setting the user and group
1428 * ids, and executing the command or shell.
1431 do_child(Session *s, const char *command)
1433 extern char **environ;
1436 const char *shell, *shell0, *hostname = NULL;
1437 struct passwd *pw = s->pw;
1439 /* remove hostkey from the child's memory */
1440 destroy_sensitive_data();
1442 /* Force a password change */
1443 if (s->authctxt->force_pwchange) {
1444 do_setusercontext(pw);
1450 /* login(1) is only called if we execute the login shell */
1451 if (options.use_login && command != NULL)
1452 options.use_login = 0;
1455 cray_setup(pw->pw_uid, pw->pw_name, command);
1456 #endif /* _UNICOS */
1459 * Login(1) does this as well, and it needs uid 0 for the "-h"
1460 * switch, so we let login(1) to this for us.
1462 if (!options.use_login) {
1464 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1465 if (!check_quietlogin(s, command))
1467 #else /* HAVE_OSF_SIA */
1469 do_setusercontext(pw);
1471 * PAM session modules in do_setusercontext may have
1472 * generated messages, so if this in an interactive
1473 * login then display them too.
1475 if (!check_quietlogin(s, command))
1477 #endif /* HAVE_OSF_SIA */
1481 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1482 debug3("PAM session not opened, exiting");
1489 * Get the shell from the password data. An empty shell field is
1490 * legal, and means /bin/sh.
1492 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1495 * Make sure $SHELL points to the shell from the password file,
1496 * even if shell is overridden from login.conf
1498 env = do_setup_env(s, shell);
1500 #ifdef HAVE_LOGIN_CAP
1501 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1504 /* we have to stash the hostname before we close our socket. */
1505 if (options.use_login)
1506 hostname = get_remote_name_or_ip(utmp_len,
1509 * Close the connection descriptors; note that this is the child, and
1510 * the server will still have the socket open, and it is important
1511 * that we do not shutdown it. Note that the descriptors cannot be
1512 * closed before building the environment, as we call
1513 * get_remote_ipaddr there.
1518 * Must take new environment into use so that .ssh/rc,
1519 * /etc/ssh/sshrc and xauth are run in the proper environment.
1523 #if defined(KRB5) && defined(USE_AFS)
1525 * At this point, we check to see if AFS is active and if we have
1526 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1527 * if we can (and need to) extend the ticket into an AFS token. If
1528 * we don't do this, we run into potential problems if the user's
1529 * home directory is in AFS and it's not world-readable.
1532 if (options.kerberos_get_afs_token && k_hasafs() &&
1533 (s->authctxt->krb5_ctx != NULL)) {
1536 debug("Getting AFS token");
1540 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1541 krb5_afslog(s->authctxt->krb5_ctx,
1542 s->authctxt->krb5_fwd_ccache, cell, NULL);
1544 krb5_afslog_home(s->authctxt->krb5_ctx,
1545 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1549 /* Change current directory to the user\'s home directory. */
1550 if (chdir(pw->pw_dir) < 0) {
1551 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1552 pw->pw_dir, strerror(errno));
1553 #ifdef HAVE_LOGIN_CAP
1554 if (login_getcapbool(lc, "requirehome", 0))
1559 if (!options.use_login)
1560 do_rc_files(s, shell);
1562 /* restore SIGPIPE for child */
1563 signal(SIGPIPE, SIG_DFL);
1565 if (options.use_login) {
1566 launch_login(pw, hostname);
1570 /* Get the last component of the shell name. */
1571 if ((shell0 = strrchr(shell, '/')) != NULL)
1577 * If we have no command, execute the shell. In this case, the shell
1578 * name to be passed in argv[0] is preceded by '-' to indicate that
1579 * this is a login shell.
1584 /* Start the shell. Set initial character to '-'. */
1587 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1588 >= sizeof(argv0) - 1) {
1594 /* Execute the shell. */
1597 execve(shell, argv, env);
1599 /* Executing the shell failed. */
1604 * Execute the command using the user's shell. This uses the -c
1605 * option to execute the command.
1607 argv[0] = (char *) shell0;
1609 argv[2] = (char *) command;
1611 execve(shell, argv, env);
1620 static int did_init = 0;
1622 debug("session_new: init");
1623 for (i = 0; i < MAX_SESSIONS; i++) {
1624 sessions[i].used = 0;
1628 for (i = 0; i < MAX_SESSIONS; i++) {
1629 Session *s = &sessions[i];
1631 memset(s, 0, sizeof(*s));
1637 s->x11_chanids = NULL;
1638 debug("session_new: session %d", i);
1649 for (i = 0; i < MAX_SESSIONS; i++) {
1650 Session *s = &sessions[i];
1651 debug("dump: used %d session %d %p channel %d pid %ld",
1661 session_open(Authctxt *authctxt, int chanid)
1663 Session *s = session_new();
1664 debug("session_open: channel %d", chanid);
1666 error("no more sessions");
1669 s->authctxt = authctxt;
1670 s->pw = authctxt->pw;
1671 if (s->pw == NULL || !authctxt->valid)
1672 fatal("no user for session %d", s->self);
1673 debug("session_open: session %d: link with channel %d", s->self, chanid);
1679 session_by_tty(char *tty)
1682 for (i = 0; i < MAX_SESSIONS; i++) {
1683 Session *s = &sessions[i];
1684 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1685 debug("session_by_tty: session %d tty %s", i, tty);
1689 debug("session_by_tty: unknown tty %.100s", tty);
1695 session_by_channel(int id)
1698 for (i = 0; i < MAX_SESSIONS; i++) {
1699 Session *s = &sessions[i];
1700 if (s->used && s->chanid == id) {
1701 debug("session_by_channel: session %d channel %d", i, id);
1705 debug("session_by_channel: unknown channel %d", id);
1711 session_by_x11_channel(int id)
1715 for (i = 0; i < MAX_SESSIONS; i++) {
1716 Session *s = &sessions[i];
1718 if (s->x11_chanids == NULL || !s->used)
1720 for (j = 0; s->x11_chanids[j] != -1; j++) {
1721 if (s->x11_chanids[j] == id) {
1722 debug("session_by_x11_channel: session %d "
1723 "channel %d", s->self, id);
1728 debug("session_by_x11_channel: unknown channel %d", id);
1734 session_by_pid(pid_t pid)
1737 debug("session_by_pid: pid %ld", (long)pid);
1738 for (i = 0; i < MAX_SESSIONS; i++) {
1739 Session *s = &sessions[i];
1740 if (s->used && s->pid == pid)
1743 error("session_by_pid: unknown pid %ld", (long)pid);
1749 session_window_change_req(Session *s)
1751 s->col = packet_get_int();
1752 s->row = packet_get_int();
1753 s->xpixel = packet_get_int();
1754 s->ypixel = packet_get_int();
1756 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1761 session_pty_req(Session *s)
1767 debug("Allocating a pty not permitted for this authentication.");
1770 if (s->ttyfd != -1) {
1771 packet_disconnect("Protocol error: you already have a pty.");
1775 s->term = packet_get_string(&len);
1778 s->col = packet_get_int();
1779 s->row = packet_get_int();
1781 s->row = packet_get_int();
1782 s->col = packet_get_int();
1784 s->xpixel = packet_get_int();
1785 s->ypixel = packet_get_int();
1787 if (strcmp(s->term, "") == 0) {
1792 /* Allocate a pty and open it. */
1793 debug("Allocating pty.");
1794 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1800 error("session_pty_req: session %d alloc failed", s->self);
1803 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1805 /* for SSH1 the tty modes length is not given */
1807 n_bytes = packet_remaining();
1808 tty_parse_modes(s->ttyfd, &n_bytes);
1811 pty_setowner(s->pw, s->tty);
1813 /* Set window size from the packet. */
1814 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1817 session_proctitle(s);
1822 session_subsystem_req(Session *s)
1827 char *cmd, *subsys = packet_get_string(&len);
1831 logit("subsystem request for %.100s", subsys);
1833 for (i = 0; i < options.num_subsystems; i++) {
1834 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1835 cmd = options.subsystem_command[i];
1836 if (stat(cmd, &st) < 0) {
1837 error("subsystem: cannot stat %s: %s", cmd,
1841 debug("subsystem: exec() %s", cmd);
1842 s->is_subsystem = 1;
1850 logit("subsystem request for %.100s failed, subsystem not found",
1858 session_x11_req(Session *s)
1862 if (s->auth_proto != NULL || s->auth_data != NULL) {
1863 error("session_x11_req: session %d: "
1864 "x11 fowarding already active", s->self);
1867 s->single_connection = packet_get_char();
1868 s->auth_proto = packet_get_string(NULL);
1869 s->auth_data = packet_get_string(NULL);
1870 s->screen = packet_get_int();
1873 success = session_setup_x11fwd(s);
1875 xfree(s->auth_proto);
1876 xfree(s->auth_data);
1877 s->auth_proto = NULL;
1878 s->auth_data = NULL;
1884 session_shell_req(Session *s)
1892 session_exec_req(Session *s)
1895 char *command = packet_get_string(&len);
1897 do_exec(s, command);
1903 session_break_req(Session *s)
1906 packet_get_int(); /* ignored */
1909 if (s->ttyfd == -1 ||
1910 tcsendbreak(s->ttyfd, 0) < 0)
1916 session_env_req(Session *s)
1919 u_int name_len, val_len, i;
1921 name = packet_get_string(&name_len);
1922 val = packet_get_string(&val_len);
1925 /* Don't set too many environment variables */
1926 if (s->num_env > 128) {
1927 debug2("Ignoring env request %s: too many env vars", name);
1931 for (i = 0; i < options.num_accept_env; i++) {
1932 if (match_pattern(name, options.accept_env[i])) {
1933 debug2("Setting env %d: %s=%s", s->num_env, name, val);
1934 s->env = xrealloc(s->env, sizeof(*s->env) *
1936 s->env[s->num_env].name = name;
1937 s->env[s->num_env].val = val;
1942 debug2("Ignoring env request %s: disallowed name", name);
1951 session_auth_agent_req(Session *s)
1953 static int called = 0;
1955 if (no_agent_forwarding_flag) {
1956 debug("session_auth_agent_req: no_agent_forwarding_flag");
1963 return auth_input_request_forwarding(s->pw);
1968 session_input_channel_req(Channel *c, const char *rtype)
1973 if ((s = session_by_channel(c->self)) == NULL) {
1974 logit("session_input_channel_req: no session %d req %.100s",
1978 debug("session_input_channel_req: session %d req %s", s->self, rtype);
1981 * a session is in LARVAL state until a shell, a command
1982 * or a subsystem is executed
1984 if (c->type == SSH_CHANNEL_LARVAL) {
1985 if (strcmp(rtype, "shell") == 0) {
1986 success = session_shell_req(s);
1987 } else if (strcmp(rtype, "exec") == 0) {
1988 success = session_exec_req(s);
1989 } else if (strcmp(rtype, "pty-req") == 0) {
1990 success = session_pty_req(s);
1991 } else if (strcmp(rtype, "x11-req") == 0) {
1992 success = session_x11_req(s);
1993 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1994 success = session_auth_agent_req(s);
1995 } else if (strcmp(rtype, "subsystem") == 0) {
1996 success = session_subsystem_req(s);
1997 } else if (strcmp(rtype, "env") == 0) {
1998 success = session_env_req(s);
2001 if (strcmp(rtype, "window-change") == 0) {
2002 success = session_window_change_req(s);
2003 } else if (strcmp(rtype, "break") == 0) {
2004 success = session_break_req(s);
2011 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2014 fatal("session_set_fds: called for proto != 2.0");
2016 * now that have a child and a pipe to the child,
2017 * we can activate our channel and register the fd's
2019 if (s->chanid == -1)
2020 fatal("no channel for session %d", s->self);
2021 channel_set_fds(s->chanid,
2023 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2025 CHAN_SES_WINDOW_DEFAULT);
2029 * Function to perform pty cleanup. Also called if we get aborted abnormally
2030 * (e.g., due to a dropped connection).
2033 session_pty_cleanup2(Session *s)
2036 error("session_pty_cleanup: no session");
2042 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2044 /* Record that the user has logged out. */
2046 record_logout(s->pid, s->tty, s->pw->pw_name);
2048 /* Release the pseudo-tty. */
2050 pty_release(s->tty);
2053 * Close the server side of the socket pairs. We must do this after
2054 * the pty cleanup, so that another process doesn't get this pty
2055 * while we're still cleaning up.
2057 if (close(s->ptymaster) < 0)
2058 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2060 /* unlink pty from session */
2065 session_pty_cleanup(Session *s)
2067 PRIVSEP(session_pty_cleanup2(s));
2073 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2088 return "SIG@openssh.com";
2092 session_close_x11(int id)
2096 if ((c = channel_lookup(id)) == NULL) {
2097 debug("session_close_x11: x11 channel %d missing", id);
2099 /* Detach X11 listener */
2100 debug("session_close_x11: detach x11 channel %d", id);
2101 channel_cancel_cleanup(id);
2102 if (c->ostate != CHAN_OUTPUT_CLOSED)
2108 session_close_single_x11(int id, void *arg)
2113 debug3("session_close_single_x11: channel %d", id);
2114 channel_cancel_cleanup(id);
2115 if ((s = session_by_x11_channel(id)) == NULL)
2116 fatal("session_close_single_x11: no x11 channel %d", id);
2117 for (i = 0; s->x11_chanids[i] != -1; i++) {
2118 debug("session_close_single_x11: session %d: "
2119 "closing channel %d", s->self, s->x11_chanids[i]);
2121 * The channel "id" is already closing, but make sure we
2122 * close all of its siblings.
2124 if (s->x11_chanids[i] != id)
2125 session_close_x11(s->x11_chanids[i]);
2127 xfree(s->x11_chanids);
2128 s->x11_chanids = NULL;
2133 if (s->auth_proto) {
2134 xfree(s->auth_proto);
2135 s->auth_proto = NULL;
2138 xfree(s->auth_data);
2139 s->auth_data = NULL;
2141 if (s->auth_display) {
2142 xfree(s->auth_display);
2143 s->auth_display = NULL;
2148 session_exit_message(Session *s, int status)
2153 if ((c = channel_lookup(s->chanid)) == NULL)
2154 fatal("session_exit_message: session %d: no channel %d",
2155 s->self, s->chanid);
2156 debug("session_exit_message: session %d channel %d pid %ld",
2157 s->self, s->chanid, (long)s->pid);
2159 if (WIFEXITED(status)) {
2160 channel_request_start(s->chanid, "exit-status", 0);
2161 packet_put_int(WEXITSTATUS(status));
2163 } else if (WIFSIGNALED(status)) {
2164 channel_request_start(s->chanid, "exit-signal", 0);
2165 packet_put_cstring(sig2name(WTERMSIG(status)));
2167 packet_put_char(WCOREDUMP(status));
2168 #else /* WCOREDUMP */
2170 #endif /* WCOREDUMP */
2171 packet_put_cstring("");
2172 packet_put_cstring("");
2175 /* Some weird exit cause. Just exit. */
2176 packet_disconnect("wait returned status %04x.", status);
2179 /* disconnect channel */
2180 debug("session_exit_message: release channel %d", s->chanid);
2181 channel_cancel_cleanup(s->chanid);
2183 * emulate a write failure with 'chan_write_failed', nobody will be
2184 * interested in data we write.
2185 * Note that we must not call 'chan_read_failed', since there could
2186 * be some more data waiting in the pipe.
2188 if (c->ostate != CHAN_OUTPUT_CLOSED)
2189 chan_write_failed(c);
2192 /* Close any X11 listeners associated with this session */
2193 if (s->x11_chanids != NULL) {
2194 for (i = 0; s->x11_chanids[i] != -1; i++) {
2195 session_close_x11(s->x11_chanids[i]);
2196 s->x11_chanids[i] = -1;
2202 session_close(Session *s)
2206 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2208 session_pty_cleanup(s);
2214 xfree(s->x11_chanids);
2215 if (s->auth_display)
2216 xfree(s->auth_display);
2218 xfree(s->auth_data);
2220 xfree(s->auth_proto);
2222 for (i = 0; i < s->num_env; i++) {
2223 xfree(s->env[i].name);
2224 xfree(s->env[i].val);
2228 session_proctitle(s);
2232 session_close_by_pid(pid_t pid, int status)
2234 Session *s = session_by_pid(pid);
2236 debug("session_close_by_pid: no session for pid %ld",
2240 if (s->chanid != -1)
2241 session_exit_message(s, status);
2246 * this is called when a channel dies before
2247 * the session 'child' itself dies
2250 session_close_by_channel(int id, void *arg)
2252 Session *s = session_by_channel(id);
2255 debug("session_close_by_channel: no session for id %d", id);
2258 debug("session_close_by_channel: channel %d child %ld",
2261 debug("session_close_by_channel: channel %d: has child", id);
2263 * delay detach of session, but release pty, since
2264 * the fd's to the child are already closed
2267 session_pty_cleanup(s);
2270 /* detach by removing callback */
2271 channel_cancel_cleanup(s->chanid);
2277 session_destroy_all(void (*closefunc)(Session *))
2280 for (i = 0; i < MAX_SESSIONS; i++) {
2281 Session *s = &sessions[i];
2283 if (closefunc != NULL)
2292 session_tty_list(void)
2294 static char buf[1024];
2299 for (i = 0; i < MAX_SESSIONS; i++) {
2300 Session *s = &sessions[i];
2301 if (s->used && s->ttyfd != -1) {
2303 if (strncmp(s->tty, "/dev/", 5) != 0) {
2304 cp = strrchr(s->tty, '/');
2305 cp = (cp == NULL) ? s->tty : cp + 1;
2310 strlcat(buf, ",", sizeof buf);
2311 strlcat(buf, cp, sizeof buf);
2315 strlcpy(buf, "notty", sizeof buf);
2320 session_proctitle(Session *s)
2323 error("no user for session %d", s->self);
2325 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2329 session_setup_x11fwd(Session *s)
2332 char display[512], auth_display[512];
2333 char hostname[MAXHOSTNAMELEN];
2336 if (no_x11_forwarding_flag) {
2337 packet_send_debug("X11 forwarding disabled in user configuration file.");
2340 if (!options.x11_forwarding) {
2341 debug("X11 forwarding disabled in server configuration file.");
2344 if (!options.xauth_location ||
2345 (stat(options.xauth_location, &st) == -1)) {
2346 packet_send_debug("No xauth program; cannot forward with spoofing.");
2349 if (options.use_login) {
2350 packet_send_debug("X11 forwarding disabled; "
2351 "not compatible with UseLogin=yes.");
2354 if (s->display != NULL) {
2355 debug("X11 display already set.");
2358 if (x11_create_display_inet(options.x11_display_offset,
2359 options.x11_use_localhost, s->single_connection,
2360 &s->display_number, &s->x11_chanids) == -1) {
2361 debug("x11_create_display_inet failed.");
2364 for (i = 0; s->x11_chanids[i] != -1; i++) {
2365 channel_register_cleanup(s->x11_chanids[i],
2366 session_close_single_x11);
2369 /* Set up a suitable value for the DISPLAY variable. */
2370 if (gethostname(hostname, sizeof(hostname)) < 0)
2371 fatal("gethostname: %.100s", strerror(errno));
2373 * auth_display must be used as the displayname when the
2374 * authorization entry is added with xauth(1). This will be
2375 * different than the DISPLAY string for localhost displays.
2377 if (options.x11_use_localhost) {
2378 snprintf(display, sizeof display, "localhost:%u.%u",
2379 s->display_number, s->screen);
2380 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2381 s->display_number, s->screen);
2382 s->display = xstrdup(display);
2383 s->auth_display = xstrdup(auth_display);
2385 #ifdef IPADDR_IN_DISPLAY
2387 struct in_addr my_addr;
2389 he = gethostbyname(hostname);
2391 error("Can't get IP address for X11 DISPLAY.");
2392 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2395 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2396 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2397 s->display_number, s->screen);
2399 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2400 s->display_number, s->screen);
2402 s->display = xstrdup(display);
2403 s->auth_display = xstrdup(display);
2410 do_authenticated2(Authctxt *authctxt)
2412 server_loop2(authctxt);
2416 do_cleanup(Authctxt *authctxt)
2418 static int called = 0;
2420 debug("do_cleanup");
2422 /* no cleanup if we're in the child for login shell */
2426 /* avoid double cleanup */
2431 if (authctxt == NULL)
2434 if (options.kerberos_ticket_cleanup &&
2436 krb5_cleanup_proc(authctxt);
2440 if (compat20 && options.gss_cleanup_creds)
2441 ssh_gssapi_cleanup_creds();
2445 if (options.use_pam) {
2447 sshpam_thread_cleanup();
2451 /* remove agent socket */
2452 auth_sock_cleanup_proc(authctxt->pw);
2455 * Cleanup ptys/utmp only if privsep is disabled,
2456 * or if running in monitor.
2458 if (!use_privsep || mm_is_monitor())
2459 session_destroy_all(session_pty_cleanup2);