1 /* $OpenBSD: session.c,v 1.212 2006/07/22 20:48:23 stevesk Exp $ */
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * As far as I am concerned, the code I have written for this software
7 * can be used freely for any purpose. Any derived versions of this
8 * software must be clearly marked as such, and if the derived work is
9 * incompatible with the protocol description in the RFC file, it must be
10 * called by a name other than "ssh" or "Secure Shell".
12 * SSH2 support by Markus Friedl.
13 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 #include <sys/types.h>
39 #ifdef HAVE_SYS_STAT_H
40 # include <sys/stat.h>
42 #include <sys/socket.h>
46 #include <arpa/inet.h>
71 #include "auth-options.h"
72 #include "pathnames.h"
76 #include "serverloop.h"
80 #include "monitor_wrap.h"
82 #if defined(KRB5) && defined(USE_AFS)
92 Session *session_new(void);
93 void session_set_fds(Session *, int, int, int);
94 void session_pty_cleanup(Session *);
95 void session_proctitle(Session *);
96 int session_setup_x11fwd(Session *);
97 void do_exec_pty(Session *, const char *);
98 void do_exec_no_pty(Session *, const char *);
99 void do_exec(Session *, const char *);
100 void do_login(Session *, const char *);
101 #ifdef LOGIN_NEEDS_UTMPX
102 static void do_pre_login(Session *s);
104 void do_child(Session *, const char *);
106 int check_quietlogin(Session *, const char *);
108 static void do_authenticated1(Authctxt *);
109 static void do_authenticated2(Authctxt *);
111 static int session_pty_req(Session *);
114 extern ServerOptions options;
115 extern char *__progname;
116 extern int log_stderr;
117 extern int debug_flag;
118 extern u_int utmp_len;
119 extern int startup_pipe;
120 extern void destroy_sensitive_data(void);
121 extern Buffer loginmsg;
123 /* original command from peer. */
124 const char *original_command = NULL;
127 #define MAX_SESSIONS 10
128 Session sessions[MAX_SESSIONS];
130 #ifdef HAVE_LOGIN_CAP
134 static int is_child = 0;
136 /* Name and directory of socket for authentication agent forwarding. */
137 static char *auth_sock_name = NULL;
138 static char *auth_sock_dir = NULL;
140 /* removes the agent forwarding socket */
143 auth_sock_cleanup_proc(struct passwd *pw)
145 if (auth_sock_name != NULL) {
146 temporarily_use_uid(pw);
147 unlink(auth_sock_name);
148 rmdir(auth_sock_dir);
149 auth_sock_name = NULL;
155 auth_input_request_forwarding(struct passwd * pw)
159 struct sockaddr_un sunaddr;
161 if (auth_sock_name != NULL) {
162 error("authentication forwarding requested twice.");
166 /* Temporarily drop privileged uid for mkdir/bind. */
167 temporarily_use_uid(pw);
169 /* Allocate a buffer for the socket name, and format the name. */
170 auth_sock_name = xmalloc(MAXPATHLEN);
171 auth_sock_dir = xmalloc(MAXPATHLEN);
172 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
174 /* Create private directory for socket */
175 if (mkdtemp(auth_sock_dir) == NULL) {
176 packet_send_debug("Agent forwarding disabled: "
177 "mkdtemp() failed: %.100s", strerror(errno));
179 xfree(auth_sock_name);
180 xfree(auth_sock_dir);
181 auth_sock_name = NULL;
182 auth_sock_dir = NULL;
185 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
186 auth_sock_dir, (long) getpid());
188 /* Create the socket. */
189 sock = socket(AF_UNIX, SOCK_STREAM, 0);
191 packet_disconnect("socket: %.100s", strerror(errno));
193 /* Bind it to the name. */
194 memset(&sunaddr, 0, sizeof(sunaddr));
195 sunaddr.sun_family = AF_UNIX;
196 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
198 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0)
199 packet_disconnect("bind: %.100s", strerror(errno));
201 /* Restore the privileged uid. */
204 /* Start listening on the socket. */
205 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
206 packet_disconnect("listen: %.100s", strerror(errno));
208 /* Allocate a channel for the authentication agent socket. */
209 nc = channel_new("auth socket",
210 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
211 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
212 0, "auth socket", 1);
213 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
218 display_loginmsg(void)
220 if (buffer_len(&loginmsg) > 0) {
221 buffer_append(&loginmsg, "\0", 1);
222 printf("%s", (char *)buffer_ptr(&loginmsg));
223 buffer_clear(&loginmsg);
228 do_authenticated(Authctxt *authctxt)
230 setproctitle("%s", authctxt->pw->pw_name);
232 /* setup the channel layer */
233 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
234 channel_permit_all_opens();
237 do_authenticated2(authctxt);
239 do_authenticated1(authctxt);
241 do_cleanup(authctxt);
245 * Prepares for an interactive session. This is called after the user has
246 * been successfully authenticated. During this message exchange, pseudo
247 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
248 * are requested, etc.
251 do_authenticated1(Authctxt *authctxt)
255 int success, type, screen_flag;
256 int enable_compression_after_reply = 0;
257 u_int proto_len, data_len, dlen, compression_level = 0;
261 error("no more sessions");
264 s->authctxt = authctxt;
265 s->pw = authctxt->pw;
268 * We stay in this loop until the client requests to execute a shell
274 /* Get a packet from the client. */
275 type = packet_read();
277 /* Process the packet. */
279 case SSH_CMSG_REQUEST_COMPRESSION:
280 compression_level = packet_get_int();
282 if (compression_level < 1 || compression_level > 9) {
283 packet_send_debug("Received invalid compression level %d.",
287 if (options.compression == COMP_NONE) {
288 debug2("compression disabled");
291 /* Enable compression after we have responded with SUCCESS. */
292 enable_compression_after_reply = 1;
296 case SSH_CMSG_REQUEST_PTY:
297 success = session_pty_req(s);
300 case SSH_CMSG_X11_REQUEST_FORWARDING:
301 s->auth_proto = packet_get_string(&proto_len);
302 s->auth_data = packet_get_string(&data_len);
304 screen_flag = packet_get_protocol_flags() &
305 SSH_PROTOFLAG_SCREEN_NUMBER;
306 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
308 if (packet_remaining() == 4) {
310 debug2("Buggy client: "
311 "X11 screen flag missing");
312 s->screen = packet_get_int();
317 success = session_setup_x11fwd(s);
319 xfree(s->auth_proto);
321 s->auth_proto = NULL;
326 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
327 if (no_agent_forwarding_flag || compat13) {
328 debug("Authentication agent forwarding not permitted for this authentication.");
331 debug("Received authentication agent forwarding request.");
332 success = auth_input_request_forwarding(s->pw);
335 case SSH_CMSG_PORT_FORWARD_REQUEST:
336 if (no_port_forwarding_flag) {
337 debug("Port forwarding not permitted for this authentication.");
340 if (!options.allow_tcp_forwarding) {
341 debug("Port forwarding not permitted.");
344 debug("Received TCP/IP port forwarding request.");
345 if (channel_input_port_forward_request(s->pw->pw_uid == 0,
346 options.gateway_ports) < 0) {
347 debug("Port forwarding failed.");
353 case SSH_CMSG_MAX_PACKET_SIZE:
354 if (packet_set_maxsize(packet_get_int()) > 0)
358 case SSH_CMSG_EXEC_SHELL:
359 case SSH_CMSG_EXEC_CMD:
360 if (type == SSH_CMSG_EXEC_CMD) {
361 command = packet_get_string(&dlen);
362 debug("Exec command '%.500s'", command);
374 * Any unknown messages in this phase are ignored,
375 * and a failure message is returned.
377 logit("Unknown packet type received after authentication: %d", type);
379 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
383 /* Enable compression now that we have replied if appropriate. */
384 if (enable_compression_after_reply) {
385 enable_compression_after_reply = 0;
386 packet_start_compression(compression_level);
392 * This is called to fork and execute a command when we have no tty. This
393 * will call do_child from the child, and server_loop from the parent after
394 * setting up file descriptors and such.
397 do_exec_no_pty(Session *s, const char *command)
402 int pin[2], pout[2], perr[2];
403 /* Allocate pipes for communicating with the program. */
404 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
405 packet_disconnect("Could not create pipes: %.100s",
407 #else /* USE_PIPES */
408 int inout[2], err[2];
409 /* Uses socket pairs to communicate with the program. */
410 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
411 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
412 packet_disconnect("Could not create socket pairs: %.100s",
414 #endif /* USE_PIPES */
416 fatal("do_exec_no_pty: no session");
418 session_proctitle(s);
421 if (options.use_pam && !use_privsep)
425 /* Fork the child. */
426 if ((pid = fork()) == 0) {
429 /* Child. Reinitialize the log since the pid has changed. */
430 log_init(__progname, options.log_level, options.log_facility, log_stderr);
433 * Create a new session and process group since the 4.4BSD
434 * setlogin() affects the entire process group.
437 error("setsid failed: %.100s", strerror(errno));
441 * Redirect stdin. We close the parent side of the socket
442 * pair, and make the child side the standard input.
445 if (dup2(pin[0], 0) < 0)
446 perror("dup2 stdin");
449 /* Redirect stdout. */
451 if (dup2(pout[1], 1) < 0)
452 perror("dup2 stdout");
455 /* Redirect stderr. */
457 if (dup2(perr[1], 2) < 0)
458 perror("dup2 stderr");
460 #else /* USE_PIPES */
462 * Redirect stdin, stdout, and stderr. Stdin and stdout will
463 * use the same socket, as some programs (particularly rdist)
464 * seem to depend on it.
468 if (dup2(inout[0], 0) < 0) /* stdin */
469 perror("dup2 stdin");
470 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
471 perror("dup2 stdout");
472 if (dup2(err[0], 2) < 0) /* stderr */
473 perror("dup2 stderr");
474 #endif /* USE_PIPES */
477 cray_init_job(s->pw); /* set up cray jid and tmpdir */
480 /* Do processing for the child (exec command etc). */
481 do_child(s, command);
485 signal(WJSIGNAL, cray_job_termination_handler);
489 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
492 packet_disconnect("fork failed: %.100s", strerror(errno));
494 /* Set interactive/non-interactive mode. */
495 packet_set_interactive(s->display != NULL);
497 /* We are the parent. Close the child sides of the pipes. */
503 if (s->is_subsystem) {
507 session_set_fds(s, pin[1], pout[0], perr[0]);
509 /* Enter the interactive session. */
510 server_loop(pid, pin[1], pout[0], perr[0]);
511 /* server_loop has closed pin[1], pout[0], and perr[0]. */
513 #else /* USE_PIPES */
514 /* We are the parent. Close the child sides of the socket pairs. */
519 * Clear loginmsg, since it's the child's responsibility to display
520 * it to the user, otherwise multiple sessions may accumulate
521 * multiple copies of the login messages.
523 buffer_clear(&loginmsg);
526 * Enter the interactive session. Note: server_loop must be able to
527 * handle the case that fdin and fdout are the same.
530 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
532 server_loop(pid, inout[1], inout[1], err[1]);
533 /* server_loop has closed inout[1] and err[1]. */
535 #endif /* USE_PIPES */
539 * This is called to fork and execute a command when we have a tty. This
540 * will call do_child from the child, and server_loop from the parent after
541 * setting up file descriptors, controlling tty, updating wtmp, utmp,
542 * lastlog, and other such operations.
545 do_exec_pty(Session *s, const char *command)
547 int fdout, ptyfd, ttyfd, ptymaster;
551 fatal("do_exec_pty: no session");
556 if (options.use_pam) {
557 do_pam_set_tty(s->tty);
563 /* Fork the child. */
564 if ((pid = fork()) == 0) {
567 /* Child. Reinitialize the log because the pid has changed. */
568 log_init(__progname, options.log_level, options.log_facility, log_stderr);
569 /* Close the master side of the pseudo tty. */
572 /* Make the pseudo tty our controlling tty. */
573 pty_make_controlling_tty(&ttyfd, s->tty);
575 /* Redirect stdin/stdout/stderr from the pseudo tty. */
576 if (dup2(ttyfd, 0) < 0)
577 error("dup2 stdin: %s", strerror(errno));
578 if (dup2(ttyfd, 1) < 0)
579 error("dup2 stdout: %s", strerror(errno));
580 if (dup2(ttyfd, 2) < 0)
581 error("dup2 stderr: %s", strerror(errno));
583 /* Close the extra descriptor for the pseudo tty. */
586 /* record login, etc. similar to login(1) */
588 if (!(options.use_login && command == NULL)) {
590 cray_init_job(s->pw); /* set up cray jid and tmpdir */
592 do_login(s, command);
594 # ifdef LOGIN_NEEDS_UTMPX
600 /* Do common processing for the child, such as execing the command. */
601 do_child(s, command);
605 signal(WJSIGNAL, cray_job_termination_handler);
609 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
612 packet_disconnect("fork failed: %.100s", strerror(errno));
615 /* Parent. Close the slave side of the pseudo tty. */
619 * Create another descriptor of the pty master side for use as the
620 * standard input. We could use the original descriptor, but this
621 * simplifies code in server_loop. The descriptor is bidirectional.
625 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
627 /* we keep a reference to the pty master */
628 ptymaster = dup(ptyfd);
630 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
631 s->ptymaster = ptymaster;
633 /* Enter interactive session. */
634 packet_set_interactive(1);
636 session_set_fds(s, ptyfd, fdout, -1);
638 server_loop(pid, ptyfd, fdout, -1);
639 /* server_loop _has_ closed ptyfd and fdout. */
643 #ifdef LOGIN_NEEDS_UTMPX
645 do_pre_login(Session *s)
648 struct sockaddr_storage from;
649 pid_t pid = getpid();
652 * Get IP address of client. If the connection is not a socket, let
653 * the address be 0.0.0.0.
655 memset(&from, 0, sizeof(from));
656 fromlen = sizeof(from);
657 if (packet_connection_is_on_socket()) {
658 if (getpeername(packet_get_connection_in(),
659 (struct sockaddr *)&from, &fromlen) < 0) {
660 debug("getpeername: %.100s", strerror(errno));
665 record_utmp_only(pid, s->tty, s->pw->pw_name,
666 get_remote_name_or_ip(utmp_len, options.use_dns),
667 (struct sockaddr *)&from, fromlen);
672 * This is called to fork and execute a command. If another command is
673 * to be forced, execute that instead.
676 do_exec(Session *s, const char *command)
678 if (options.adm_forced_command) {
679 original_command = command;
680 command = options.adm_forced_command;
681 debug("Forced command (config) '%.900s'", command);
682 } else if (forced_command) {
683 original_command = command;
684 command = forced_command;
685 debug("Forced command (key option) '%.900s'", command);
688 #ifdef SSH_AUDIT_EVENTS
690 PRIVSEP(audit_run_command(command));
691 else if (s->ttyfd == -1) {
692 char *shell = s->pw->pw_shell;
694 if (shell[0] == '\0') /* empty shell means /bin/sh */
696 PRIVSEP(audit_run_command(shell));
701 do_exec_pty(s, command);
703 do_exec_no_pty(s, command);
705 original_command = NULL;
708 * Clear loginmsg: it's the child's responsibility to display
709 * it to the user, otherwise multiple sessions may accumulate
710 * multiple copies of the login messages.
712 buffer_clear(&loginmsg);
715 /* administrative, login(1)-like work */
717 do_login(Session *s, const char *command)
720 struct sockaddr_storage from;
721 struct passwd * pw = s->pw;
722 pid_t pid = getpid();
725 * Get IP address of client. If the connection is not a socket, let
726 * the address be 0.0.0.0.
728 memset(&from, 0, sizeof(from));
729 fromlen = sizeof(from);
730 if (packet_connection_is_on_socket()) {
731 if (getpeername(packet_get_connection_in(),
732 (struct sockaddr *) & from, &fromlen) < 0) {
733 debug("getpeername: %.100s", strerror(errno));
738 /* Record that there was a login on that tty from the remote host. */
740 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
741 get_remote_name_or_ip(utmp_len,
743 (struct sockaddr *)&from, fromlen);
747 * If password change is needed, do it now.
748 * This needs to occur before the ~/.hushlogin check.
750 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
753 s->authctxt->force_pwchange = 0;
754 /* XXX - signal [net] parent to enable forwardings */
758 if (check_quietlogin(s, command))
767 * Display the message of the day.
775 if (options.print_motd) {
776 #ifdef HAVE_LOGIN_CAP
777 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
780 f = fopen("/etc/motd", "r");
783 while (fgets(buf, sizeof(buf), f))
792 * Check for quiet login, either .hushlogin or command given.
795 check_quietlogin(Session *s, const char *command)
798 struct passwd *pw = s->pw;
801 /* Return 1 if .hushlogin exists or a command given. */
804 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
805 #ifdef HAVE_LOGIN_CAP
806 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
809 if (stat(buf, &st) >= 0)
816 * Sets the value of the given variable in the environment. If the variable
817 * already exists, its value is overriden.
820 child_set_env(char ***envp, u_int *envsizep, const char *name,
828 * If we're passed an uninitialized list, allocate a single null
829 * entry before continuing.
831 if (*envp == NULL && *envsizep == 0) {
832 *envp = xmalloc(sizeof(char *));
838 * Find the slot where the value should be stored. If the variable
839 * already exists, we reuse the slot; otherwise we append a new slot
840 * at the end of the array, expanding if necessary.
843 namelen = strlen(name);
844 for (i = 0; env[i]; i++)
845 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
848 /* Reuse the slot. */
851 /* New variable. Expand if necessary. */
853 if (i >= envsize - 1) {
855 fatal("child_set_env: too many env vars");
857 env = (*envp) = xrealloc(env, envsize, sizeof(char *));
860 /* Need to set the NULL pointer at end of array beyond the new slot. */
864 /* Allocate space and format the variable in the appropriate slot. */
865 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
866 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
870 * Reads environment variables from the given file and adds/overrides them
871 * into the environment. If the file does not exist, this does nothing.
872 * Otherwise, it must consist of empty lines, comments (line starts with '#')
873 * and assignments of the form name=value. No other forms are allowed.
876 read_environment_file(char ***env, u_int *envsize,
877 const char *filename)
884 f = fopen(filename, "r");
888 while (fgets(buf, sizeof(buf), f)) {
890 fatal("Too many lines in environment file %s", filename);
891 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
893 if (!*cp || *cp == '#' || *cp == '\n')
895 if (strchr(cp, '\n'))
896 *strchr(cp, '\n') = '\0';
897 value = strchr(cp, '=');
899 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
904 * Replace the equals sign by nul, and advance value to
909 child_set_env(env, envsize, cp, value);
914 #ifdef HAVE_ETC_DEFAULT_LOGIN
916 * Return named variable from specified environment, or NULL if not present.
919 child_get_env(char **env, const char *name)
925 for (i=0; env[i] != NULL; i++)
926 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
927 return(env[i] + len + 1);
932 * Read /etc/default/login.
933 * We pick up the PATH (or SUPATH for root) and UMASK.
936 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
938 char **tmpenv = NULL, *var;
939 u_int i, tmpenvsize = 0;
943 * We don't want to copy the whole file to the child's environment,
944 * so we use a temporary environment and copy the variables we're
947 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
953 var = child_get_env(tmpenv, "SUPATH");
955 var = child_get_env(tmpenv, "PATH");
957 child_set_env(env, envsize, "PATH", var);
959 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
960 if (sscanf(var, "%5lo", &mask) == 1)
963 for (i = 0; tmpenv[i] != NULL; i++)
967 #endif /* HAVE_ETC_DEFAULT_LOGIN */
970 copy_environment(char **source, char ***env, u_int *envsize)
972 char *var_name, *var_val;
978 for(i = 0; source[i] != NULL; i++) {
979 var_name = xstrdup(source[i]);
980 if ((var_val = strstr(var_name, "=")) == NULL) {
986 debug3("Copy environment: %s=%s", var_name, var_val);
987 child_set_env(env, envsize, var_name, var_val);
994 do_setup_env(Session *s, const char *shell)
998 char **env, *laddr, *path = NULL;
999 struct passwd *pw = s->pw;
1001 /* Initialize the environment. */
1003 env = xcalloc(envsize, sizeof(char *));
1008 * The Windows environment contains some setting which are
1009 * important for a running system. They must not be dropped.
1014 p = fetch_windows_environment();
1015 copy_environment(p, &env, &envsize);
1016 free_windows_environment(p);
1021 /* Allow any GSSAPI methods that we've used to alter
1022 * the childs environment as they see fit
1024 ssh_gssapi_do_child(&env, &envsize);
1027 if (!options.use_login) {
1028 /* Set basic environment. */
1029 for (i = 0; i < s->num_env; i++)
1030 child_set_env(&env, &envsize, s->env[i].name,
1033 child_set_env(&env, &envsize, "USER", pw->pw_name);
1034 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1036 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1038 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1039 #ifdef HAVE_LOGIN_CAP
1040 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1041 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1043 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1044 #else /* HAVE_LOGIN_CAP */
1045 # ifndef HAVE_CYGWIN
1047 * There's no standard path on Windows. The path contains
1048 * important components pointing to the system directories,
1049 * needed for loading shared libraries. So the path better
1050 * remains intact here.
1052 # ifdef HAVE_ETC_DEFAULT_LOGIN
1053 read_etc_default_login(&env, &envsize, pw->pw_uid);
1054 path = child_get_env(env, "PATH");
1055 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1056 if (path == NULL || *path == '\0') {
1057 child_set_env(&env, &envsize, "PATH",
1058 s->pw->pw_uid == 0 ?
1059 SUPERUSER_PATH : _PATH_STDPATH);
1061 # endif /* HAVE_CYGWIN */
1062 #endif /* HAVE_LOGIN_CAP */
1064 snprintf(buf, sizeof buf, "%.200s/%.50s",
1065 _PATH_MAILDIR, pw->pw_name);
1066 child_set_env(&env, &envsize, "MAIL", buf);
1068 /* Normal systems set SHELL by default. */
1069 child_set_env(&env, &envsize, "SHELL", shell);
1072 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1074 /* Set custom environment options from RSA authentication. */
1075 if (!options.use_login) {
1076 while (custom_environment) {
1077 struct envstring *ce = custom_environment;
1080 for (i = 0; str[i] != '=' && str[i]; i++)
1082 if (str[i] == '=') {
1084 child_set_env(&env, &envsize, str, str + i + 1);
1086 custom_environment = ce->next;
1092 /* SSH_CLIENT deprecated */
1093 snprintf(buf, sizeof buf, "%.50s %d %d",
1094 get_remote_ipaddr(), get_remote_port(), get_local_port());
1095 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1097 laddr = get_local_ipaddr(packet_get_connection_in());
1098 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1099 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1101 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1104 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1106 child_set_env(&env, &envsize, "TERM", s->term);
1108 child_set_env(&env, &envsize, "DISPLAY", s->display);
1109 if (original_command)
1110 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1114 if (cray_tmpdir[0] != '\0')
1115 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1116 #endif /* _UNICOS */
1119 * Since we clear KRB5CCNAME at startup, if it's set now then it
1120 * must have been set by a native authentication method (eg AIX or
1121 * SIA), so copy it to the child.
1126 if ((cp = getenv("KRB5CCNAME")) != NULL)
1127 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1134 if ((cp = getenv("AUTHSTATE")) != NULL)
1135 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1136 read_environment_file(&env, &envsize, "/etc/environment");
1140 if (s->authctxt->krb5_ccname)
1141 child_set_env(&env, &envsize, "KRB5CCNAME",
1142 s->authctxt->krb5_ccname);
1146 * Pull in any environment variables that may have
1149 if (options.use_pam) {
1152 p = fetch_pam_child_environment();
1153 copy_environment(p, &env, &envsize);
1154 free_pam_environment(p);
1156 p = fetch_pam_environment();
1157 copy_environment(p, &env, &envsize);
1158 free_pam_environment(p);
1160 #endif /* USE_PAM */
1162 if (auth_sock_name != NULL)
1163 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1166 /* read $HOME/.ssh/environment. */
1167 if (options.permit_user_env && !options.use_login) {
1168 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1169 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1170 read_environment_file(&env, &envsize, buf);
1173 /* dump the environment */
1174 fprintf(stderr, "Environment:\n");
1175 for (i = 0; env[i]; i++)
1176 fprintf(stderr, " %.200s\n", env[i]);
1182 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1183 * first in this order).
1186 do_rc_files(Session *s, const char *shell)
1194 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1196 /* ignore _PATH_SSH_USER_RC for subsystems */
1197 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1198 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1199 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1201 fprintf(stderr, "Running %s\n", cmd);
1202 f = popen(cmd, "w");
1205 fprintf(f, "%s %s\n", s->auth_proto,
1209 fprintf(stderr, "Could not run %s\n",
1211 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1213 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1214 _PATH_SSH_SYSTEM_RC);
1215 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1218 fprintf(f, "%s %s\n", s->auth_proto,
1222 fprintf(stderr, "Could not run %s\n",
1223 _PATH_SSH_SYSTEM_RC);
1224 } else if (do_xauth && options.xauth_location != NULL) {
1225 /* Add authority data to .Xauthority if appropriate. */
1228 "Running %.500s remove %.100s\n",
1229 options.xauth_location, s->auth_display);
1231 "%.500s add %.100s %.100s %.100s\n",
1232 options.xauth_location, s->auth_display,
1233 s->auth_proto, s->auth_data);
1235 snprintf(cmd, sizeof cmd, "%s -q -",
1236 options.xauth_location);
1237 f = popen(cmd, "w");
1239 fprintf(f, "remove %s\n",
1241 fprintf(f, "add %s %s %s\n",
1242 s->auth_display, s->auth_proto,
1246 fprintf(stderr, "Could not run %s\n",
1253 do_nologin(struct passwd *pw)
1258 #ifdef HAVE_LOGIN_CAP
1259 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1260 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1261 _PATH_NOLOGIN), "r");
1264 f = fopen(_PATH_NOLOGIN, "r");
1267 /* /etc/nologin exists. Print its contents and exit. */
1268 logit("User %.100s not allowed because %s exists",
1269 pw->pw_name, _PATH_NOLOGIN);
1270 while (fgets(buf, sizeof(buf), f))
1278 /* Set login name, uid, gid, and groups. */
1280 do_setusercontext(struct passwd *pw)
1283 if (getuid() == 0 || geteuid() == 0)
1284 #endif /* HAVE_CYGWIN */
1287 #ifdef HAVE_SETPCRED
1288 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1289 fatal("Failed to set process credentials");
1290 #endif /* HAVE_SETPCRED */
1291 #ifdef HAVE_LOGIN_CAP
1296 if (options.gss_authentication) {
1297 temporarily_use_uid(pw);
1298 ssh_gssapi_storecreds();
1303 if (options.use_pam) {
1307 # endif /* USE_PAM */
1308 if (setusercontext(lc, pw, pw->pw_uid,
1309 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1310 perror("unable to set user context");
1314 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1315 /* Sets login uid for accounting */
1316 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1317 error("setluid: %s", strerror(errno));
1318 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1320 if (setlogin(pw->pw_name) < 0)
1321 error("setlogin failed: %s", strerror(errno));
1322 if (setgid(pw->pw_gid) < 0) {
1326 /* Initialize the group list. */
1327 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1328 perror("initgroups");
1333 if (options.gss_authentication) {
1334 temporarily_use_uid(pw);
1335 ssh_gssapi_storecreds();
1341 * PAM credentials may take the form of supplementary groups.
1342 * These will have been wiped by the above initgroups() call.
1343 * Reestablish them here.
1345 if (options.use_pam) {
1349 # endif /* USE_PAM */
1350 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1351 irix_setusercontext(pw);
1352 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1356 #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
1357 if (set_id(pw->pw_name) != 0) {
1360 #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
1361 /* Permanently switch to the desired uid. */
1362 permanently_set_uid(pw);
1369 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1370 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1373 ssh_selinux_setup_exec_context(pw->pw_name);
1378 do_pwchange(Session *s)
1381 fprintf(stderr, "WARNING: Your password has expired.\n");
1382 if (s->ttyfd != -1) {
1384 "You must change your password now and login again!\n");
1385 #ifdef PASSWD_NEEDS_USERNAME
1386 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1389 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1394 "Password change required but no TTY available.\n");
1400 launch_login(struct passwd *pw, const char *hostname)
1402 /* Launch login(1). */
1404 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1405 #ifdef xxxLOGIN_NEEDS_TERM
1406 (s->term ? s->term : "unknown"),
1407 #endif /* LOGIN_NEEDS_TERM */
1408 #ifdef LOGIN_NO_ENDOPT
1409 "-p", "-f", pw->pw_name, (char *)NULL);
1411 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1414 /* Login couldn't be executed, die. */
1421 child_close_fds(void)
1425 if (packet_get_connection_in() == packet_get_connection_out())
1426 close(packet_get_connection_in());
1428 close(packet_get_connection_in());
1429 close(packet_get_connection_out());
1432 * Close all descriptors related to channels. They will still remain
1433 * open in the parent.
1435 /* XXX better use close-on-exec? -markus */
1436 channel_close_all();
1439 * Close any extra file descriptors. Note that there may still be
1440 * descriptors left by system functions. They will be closed later.
1445 * Close any extra open file descriptors so that we don't have them
1446 * hanging around in clients. Note that we want to do this after
1447 * initgroups, because at least on Solaris 2.3 it leaves file
1450 for (i = 3; i < 64; i++)
1455 * Performs common processing for the child, such as setting up the
1456 * environment, closing extra file descriptors, setting the user and group
1457 * ids, and executing the command or shell.
1460 do_child(Session *s, const char *command)
1462 extern char **environ;
1465 const char *shell, *shell0, *hostname = NULL;
1466 struct passwd *pw = s->pw;
1468 /* remove hostkey from the child's memory */
1469 destroy_sensitive_data();
1471 /* Force a password change */
1472 if (s->authctxt->force_pwchange) {
1473 do_setusercontext(pw);
1479 /* login(1) is only called if we execute the login shell */
1480 if (options.use_login && command != NULL)
1481 options.use_login = 0;
1484 cray_setup(pw->pw_uid, pw->pw_name, command);
1485 #endif /* _UNICOS */
1488 * Login(1) does this as well, and it needs uid 0 for the "-h"
1489 * switch, so we let login(1) to this for us.
1491 if (!options.use_login) {
1493 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1494 if (!check_quietlogin(s, command))
1496 #else /* HAVE_OSF_SIA */
1497 /* When PAM is enabled we rely on it to do the nologin check */
1498 if (!options.use_pam)
1500 do_setusercontext(pw);
1502 * PAM session modules in do_setusercontext may have
1503 * generated messages, so if this in an interactive
1504 * login then display them too.
1506 if (!check_quietlogin(s, command))
1508 #endif /* HAVE_OSF_SIA */
1512 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1513 debug3("PAM session not opened, exiting");
1520 * Get the shell from the password data. An empty shell field is
1521 * legal, and means /bin/sh.
1523 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1526 * Make sure $SHELL points to the shell from the password file,
1527 * even if shell is overridden from login.conf
1529 env = do_setup_env(s, shell);
1531 #ifdef HAVE_LOGIN_CAP
1532 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1535 /* we have to stash the hostname before we close our socket. */
1536 if (options.use_login)
1537 hostname = get_remote_name_or_ip(utmp_len,
1540 * Close the connection descriptors; note that this is the child, and
1541 * the server will still have the socket open, and it is important
1542 * that we do not shutdown it. Note that the descriptors cannot be
1543 * closed before building the environment, as we call
1544 * get_remote_ipaddr there.
1549 * Must take new environment into use so that .ssh/rc,
1550 * /etc/ssh/sshrc and xauth are run in the proper environment.
1554 #if defined(KRB5) && defined(USE_AFS)
1556 * At this point, we check to see if AFS is active and if we have
1557 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1558 * if we can (and need to) extend the ticket into an AFS token. If
1559 * we don't do this, we run into potential problems if the user's
1560 * home directory is in AFS and it's not world-readable.
1563 if (options.kerberos_get_afs_token && k_hasafs() &&
1564 (s->authctxt->krb5_ctx != NULL)) {
1567 debug("Getting AFS token");
1571 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1572 krb5_afslog(s->authctxt->krb5_ctx,
1573 s->authctxt->krb5_fwd_ccache, cell, NULL);
1575 krb5_afslog_home(s->authctxt->krb5_ctx,
1576 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1580 /* Change current directory to the user's home directory. */
1581 if (chdir(pw->pw_dir) < 0) {
1582 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1583 pw->pw_dir, strerror(errno));
1584 #ifdef HAVE_LOGIN_CAP
1585 if (login_getcapbool(lc, "requirehome", 0))
1590 if (!options.use_login)
1591 do_rc_files(s, shell);
1593 /* restore SIGPIPE for child */
1594 signal(SIGPIPE, SIG_DFL);
1596 if (options.use_login) {
1597 launch_login(pw, hostname);
1601 /* Get the last component of the shell name. */
1602 if ((shell0 = strrchr(shell, '/')) != NULL)
1608 * If we have no command, execute the shell. In this case, the shell
1609 * name to be passed in argv[0] is preceded by '-' to indicate that
1610 * this is a login shell.
1615 /* Start the shell. Set initial character to '-'. */
1618 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1619 >= sizeof(argv0) - 1) {
1625 /* Execute the shell. */
1628 execve(shell, argv, env);
1630 /* Executing the shell failed. */
1635 * Execute the command using the user's shell. This uses the -c
1636 * option to execute the command.
1638 argv[0] = (char *) shell0;
1640 argv[2] = (char *) command;
1642 execve(shell, argv, env);
1651 static int did_init = 0;
1653 debug("session_new: init");
1654 for (i = 0; i < MAX_SESSIONS; i++) {
1655 sessions[i].used = 0;
1659 for (i = 0; i < MAX_SESSIONS; i++) {
1660 Session *s = &sessions[i];
1662 memset(s, 0, sizeof(*s));
1668 s->x11_chanids = NULL;
1669 debug("session_new: session %d", i);
1680 for (i = 0; i < MAX_SESSIONS; i++) {
1681 Session *s = &sessions[i];
1682 debug("dump: used %d session %d %p channel %d pid %ld",
1692 session_open(Authctxt *authctxt, int chanid)
1694 Session *s = session_new();
1695 debug("session_open: channel %d", chanid);
1697 error("no more sessions");
1700 s->authctxt = authctxt;
1701 s->pw = authctxt->pw;
1702 if (s->pw == NULL || !authctxt->valid)
1703 fatal("no user for session %d", s->self);
1704 debug("session_open: session %d: link with channel %d", s->self, chanid);
1710 session_by_tty(char *tty)
1713 for (i = 0; i < MAX_SESSIONS; i++) {
1714 Session *s = &sessions[i];
1715 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1716 debug("session_by_tty: session %d tty %s", i, tty);
1720 debug("session_by_tty: unknown tty %.100s", tty);
1726 session_by_channel(int id)
1729 for (i = 0; i < MAX_SESSIONS; i++) {
1730 Session *s = &sessions[i];
1731 if (s->used && s->chanid == id) {
1732 debug("session_by_channel: session %d channel %d", i, id);
1736 debug("session_by_channel: unknown channel %d", id);
1742 session_by_x11_channel(int id)
1746 for (i = 0; i < MAX_SESSIONS; i++) {
1747 Session *s = &sessions[i];
1749 if (s->x11_chanids == NULL || !s->used)
1751 for (j = 0; s->x11_chanids[j] != -1; j++) {
1752 if (s->x11_chanids[j] == id) {
1753 debug("session_by_x11_channel: session %d "
1754 "channel %d", s->self, id);
1759 debug("session_by_x11_channel: unknown channel %d", id);
1765 session_by_pid(pid_t pid)
1768 debug("session_by_pid: pid %ld", (long)pid);
1769 for (i = 0; i < MAX_SESSIONS; i++) {
1770 Session *s = &sessions[i];
1771 if (s->used && s->pid == pid)
1774 error("session_by_pid: unknown pid %ld", (long)pid);
1780 session_window_change_req(Session *s)
1782 s->col = packet_get_int();
1783 s->row = packet_get_int();
1784 s->xpixel = packet_get_int();
1785 s->ypixel = packet_get_int();
1787 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1792 session_pty_req(Session *s)
1798 debug("Allocating a pty not permitted for this authentication.");
1801 if (s->ttyfd != -1) {
1802 packet_disconnect("Protocol error: you already have a pty.");
1806 s->term = packet_get_string(&len);
1809 s->col = packet_get_int();
1810 s->row = packet_get_int();
1812 s->row = packet_get_int();
1813 s->col = packet_get_int();
1815 s->xpixel = packet_get_int();
1816 s->ypixel = packet_get_int();
1818 if (strcmp(s->term, "") == 0) {
1823 /* Allocate a pty and open it. */
1824 debug("Allocating pty.");
1825 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1831 error("session_pty_req: session %d alloc failed", s->self);
1834 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1836 /* for SSH1 the tty modes length is not given */
1838 n_bytes = packet_remaining();
1839 tty_parse_modes(s->ttyfd, &n_bytes);
1842 pty_setowner(s->pw, s->tty);
1844 /* Set window size from the packet. */
1845 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1848 session_proctitle(s);
1853 session_subsystem_req(Session *s)
1858 char *prog, *cmd, *subsys = packet_get_string(&len);
1862 logit("subsystem request for %.100s", subsys);
1864 for (i = 0; i < options.num_subsystems; i++) {
1865 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1866 prog = options.subsystem_command[i];
1867 cmd = options.subsystem_args[i];
1868 if (stat(prog, &st) < 0) {
1869 error("subsystem: cannot stat %s: %s", prog,
1873 debug("subsystem: exec() %s", cmd);
1874 s->is_subsystem = 1;
1882 logit("subsystem request for %.100s failed, subsystem not found",
1890 session_x11_req(Session *s)
1894 if (s->auth_proto != NULL || s->auth_data != NULL) {
1895 error("session_x11_req: session %d: "
1896 "x11 forwarding already active", s->self);
1899 s->single_connection = packet_get_char();
1900 s->auth_proto = packet_get_string(NULL);
1901 s->auth_data = packet_get_string(NULL);
1902 s->screen = packet_get_int();
1905 success = session_setup_x11fwd(s);
1907 xfree(s->auth_proto);
1908 xfree(s->auth_data);
1909 s->auth_proto = NULL;
1910 s->auth_data = NULL;
1916 session_shell_req(Session *s)
1924 session_exec_req(Session *s)
1927 char *command = packet_get_string(&len);
1929 do_exec(s, command);
1935 session_break_req(Session *s)
1938 packet_get_int(); /* ignored */
1941 if (s->ttyfd == -1 ||
1942 tcsendbreak(s->ttyfd, 0) < 0)
1948 session_env_req(Session *s)
1951 u_int name_len, val_len, i;
1953 name = packet_get_string(&name_len);
1954 val = packet_get_string(&val_len);
1957 /* Don't set too many environment variables */
1958 if (s->num_env > 128) {
1959 debug2("Ignoring env request %s: too many env vars", name);
1963 for (i = 0; i < options.num_accept_env; i++) {
1964 if (match_pattern(name, options.accept_env[i])) {
1965 debug2("Setting env %d: %s=%s", s->num_env, name, val);
1966 s->env = xrealloc(s->env, s->num_env + 1,
1968 s->env[s->num_env].name = name;
1969 s->env[s->num_env].val = val;
1974 debug2("Ignoring env request %s: disallowed name", name);
1983 session_auth_agent_req(Session *s)
1985 static int called = 0;
1987 if (no_agent_forwarding_flag) {
1988 debug("session_auth_agent_req: no_agent_forwarding_flag");
1995 return auth_input_request_forwarding(s->pw);
2000 session_input_channel_req(Channel *c, const char *rtype)
2005 if ((s = session_by_channel(c->self)) == NULL) {
2006 logit("session_input_channel_req: no session %d req %.100s",
2010 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2013 * a session is in LARVAL state until a shell, a command
2014 * or a subsystem is executed
2016 if (c->type == SSH_CHANNEL_LARVAL) {
2017 if (strcmp(rtype, "shell") == 0) {
2018 success = session_shell_req(s);
2019 } else if (strcmp(rtype, "exec") == 0) {
2020 success = session_exec_req(s);
2021 } else if (strcmp(rtype, "pty-req") == 0) {
2022 success = session_pty_req(s);
2023 } else if (strcmp(rtype, "x11-req") == 0) {
2024 success = session_x11_req(s);
2025 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2026 success = session_auth_agent_req(s);
2027 } else if (strcmp(rtype, "subsystem") == 0) {
2028 success = session_subsystem_req(s);
2029 } else if (strcmp(rtype, "env") == 0) {
2030 success = session_env_req(s);
2033 if (strcmp(rtype, "window-change") == 0) {
2034 success = session_window_change_req(s);
2035 } else if (strcmp(rtype, "break") == 0) {
2036 success = session_break_req(s);
2043 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2046 fatal("session_set_fds: called for proto != 2.0");
2048 * now that have a child and a pipe to the child,
2049 * we can activate our channel and register the fd's
2051 if (s->chanid == -1)
2052 fatal("no channel for session %d", s->self);
2053 channel_set_fds(s->chanid,
2055 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2057 CHAN_SES_WINDOW_DEFAULT);
2061 * Function to perform pty cleanup. Also called if we get aborted abnormally
2062 * (e.g., due to a dropped connection).
2065 session_pty_cleanup2(Session *s)
2068 error("session_pty_cleanup: no session");
2074 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2076 /* Record that the user has logged out. */
2078 record_logout(s->pid, s->tty, s->pw->pw_name);
2080 /* Release the pseudo-tty. */
2082 pty_release(s->tty);
2085 * Close the server side of the socket pairs. We must do this after
2086 * the pty cleanup, so that another process doesn't get this pty
2087 * while we're still cleaning up.
2089 if (close(s->ptymaster) < 0)
2090 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2092 /* unlink pty from session */
2097 session_pty_cleanup(Session *s)
2099 PRIVSEP(session_pty_cleanup2(s));
2105 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2120 return "SIG@openssh.com";
2124 session_close_x11(int id)
2128 if ((c = channel_by_id(id)) == NULL) {
2129 debug("session_close_x11: x11 channel %d missing", id);
2131 /* Detach X11 listener */
2132 debug("session_close_x11: detach x11 channel %d", id);
2133 channel_cancel_cleanup(id);
2134 if (c->ostate != CHAN_OUTPUT_CLOSED)
2140 session_close_single_x11(int id, void *arg)
2145 debug3("session_close_single_x11: channel %d", id);
2146 channel_cancel_cleanup(id);
2147 if ((s = session_by_x11_channel(id)) == NULL)
2148 fatal("session_close_single_x11: no x11 channel %d", id);
2149 for (i = 0; s->x11_chanids[i] != -1; i++) {
2150 debug("session_close_single_x11: session %d: "
2151 "closing channel %d", s->self, s->x11_chanids[i]);
2153 * The channel "id" is already closing, but make sure we
2154 * close all of its siblings.
2156 if (s->x11_chanids[i] != id)
2157 session_close_x11(s->x11_chanids[i]);
2159 xfree(s->x11_chanids);
2160 s->x11_chanids = NULL;
2165 if (s->auth_proto) {
2166 xfree(s->auth_proto);
2167 s->auth_proto = NULL;
2170 xfree(s->auth_data);
2171 s->auth_data = NULL;
2173 if (s->auth_display) {
2174 xfree(s->auth_display);
2175 s->auth_display = NULL;
2180 session_exit_message(Session *s, int status)
2184 if ((c = channel_lookup(s->chanid)) == NULL)
2185 fatal("session_exit_message: session %d: no channel %d",
2186 s->self, s->chanid);
2187 debug("session_exit_message: session %d channel %d pid %ld",
2188 s->self, s->chanid, (long)s->pid);
2190 if (WIFEXITED(status)) {
2191 channel_request_start(s->chanid, "exit-status", 0);
2192 packet_put_int(WEXITSTATUS(status));
2194 } else if (WIFSIGNALED(status)) {
2195 channel_request_start(s->chanid, "exit-signal", 0);
2196 packet_put_cstring(sig2name(WTERMSIG(status)));
2198 packet_put_char(WCOREDUMP(status));
2199 #else /* WCOREDUMP */
2201 #endif /* WCOREDUMP */
2202 packet_put_cstring("");
2203 packet_put_cstring("");
2206 /* Some weird exit cause. Just exit. */
2207 packet_disconnect("wait returned status %04x.", status);
2210 /* disconnect channel */
2211 debug("session_exit_message: release channel %d", s->chanid);
2214 * Adjust cleanup callback attachment to send close messages when
2215 * the channel gets EOF. The session will be then be closed
2216 * by session_close_by_channel when the childs close their fds.
2218 channel_register_cleanup(c->self, session_close_by_channel, 1);
2221 * emulate a write failure with 'chan_write_failed', nobody will be
2222 * interested in data we write.
2223 * Note that we must not call 'chan_read_failed', since there could
2224 * be some more data waiting in the pipe.
2226 if (c->ostate != CHAN_OUTPUT_CLOSED)
2227 chan_write_failed(c);
2231 session_close(Session *s)
2235 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2237 session_pty_cleanup(s);
2243 xfree(s->x11_chanids);
2244 if (s->auth_display)
2245 xfree(s->auth_display);
2247 xfree(s->auth_data);
2249 xfree(s->auth_proto);
2251 for (i = 0; i < s->num_env; i++) {
2252 xfree(s->env[i].name);
2253 xfree(s->env[i].val);
2257 session_proctitle(s);
2261 session_close_by_pid(pid_t pid, int status)
2263 Session *s = session_by_pid(pid);
2265 debug("session_close_by_pid: no session for pid %ld",
2269 if (s->chanid != -1)
2270 session_exit_message(s, status);
2272 session_pty_cleanup(s);
2277 * this is called when a channel dies before
2278 * the session 'child' itself dies
2281 session_close_by_channel(int id, void *arg)
2283 Session *s = session_by_channel(id);
2287 debug("session_close_by_channel: no session for id %d", id);
2290 debug("session_close_by_channel: channel %d child %ld",
2293 debug("session_close_by_channel: channel %d: has child", id);
2295 * delay detach of session, but release pty, since
2296 * the fd's to the child are already closed
2299 session_pty_cleanup(s);
2302 /* detach by removing callback */
2303 channel_cancel_cleanup(s->chanid);
2305 /* Close any X11 listeners associated with this session */
2306 if (s->x11_chanids != NULL) {
2307 for (i = 0; s->x11_chanids[i] != -1; i++) {
2308 session_close_x11(s->x11_chanids[i]);
2309 s->x11_chanids[i] = -1;
2318 session_destroy_all(void (*closefunc)(Session *))
2321 for (i = 0; i < MAX_SESSIONS; i++) {
2322 Session *s = &sessions[i];
2324 if (closefunc != NULL)
2333 session_tty_list(void)
2335 static char buf[1024];
2340 for (i = 0; i < MAX_SESSIONS; i++) {
2341 Session *s = &sessions[i];
2342 if (s->used && s->ttyfd != -1) {
2344 if (strncmp(s->tty, "/dev/", 5) != 0) {
2345 cp = strrchr(s->tty, '/');
2346 cp = (cp == NULL) ? s->tty : cp + 1;
2351 strlcat(buf, ",", sizeof buf);
2352 strlcat(buf, cp, sizeof buf);
2356 strlcpy(buf, "notty", sizeof buf);
2361 session_proctitle(Session *s)
2364 error("no user for session %d", s->self);
2366 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2370 session_setup_x11fwd(Session *s)
2373 char display[512], auth_display[512];
2374 char hostname[MAXHOSTNAMELEN];
2377 if (no_x11_forwarding_flag) {
2378 packet_send_debug("X11 forwarding disabled in user configuration file.");
2381 if (!options.x11_forwarding) {
2382 debug("X11 forwarding disabled in server configuration file.");
2385 if (!options.xauth_location ||
2386 (stat(options.xauth_location, &st) == -1)) {
2387 packet_send_debug("No xauth program; cannot forward with spoofing.");
2390 if (options.use_login) {
2391 packet_send_debug("X11 forwarding disabled; "
2392 "not compatible with UseLogin=yes.");
2395 if (s->display != NULL) {
2396 debug("X11 display already set.");
2399 if (x11_create_display_inet(options.x11_display_offset,
2400 options.x11_use_localhost, s->single_connection,
2401 &s->display_number, &s->x11_chanids) == -1) {
2402 debug("x11_create_display_inet failed.");
2405 for (i = 0; s->x11_chanids[i] != -1; i++) {
2406 channel_register_cleanup(s->x11_chanids[i],
2407 session_close_single_x11, 0);
2410 /* Set up a suitable value for the DISPLAY variable. */
2411 if (gethostname(hostname, sizeof(hostname)) < 0)
2412 fatal("gethostname: %.100s", strerror(errno));
2414 * auth_display must be used as the displayname when the
2415 * authorization entry is added with xauth(1). This will be
2416 * different than the DISPLAY string for localhost displays.
2418 if (options.x11_use_localhost) {
2419 snprintf(display, sizeof display, "localhost:%u.%u",
2420 s->display_number, s->screen);
2421 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2422 s->display_number, s->screen);
2423 s->display = xstrdup(display);
2424 s->auth_display = xstrdup(auth_display);
2426 #ifdef IPADDR_IN_DISPLAY
2428 struct in_addr my_addr;
2430 he = gethostbyname(hostname);
2432 error("Can't get IP address for X11 DISPLAY.");
2433 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2436 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2437 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2438 s->display_number, s->screen);
2440 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2441 s->display_number, s->screen);
2443 s->display = xstrdup(display);
2444 s->auth_display = xstrdup(display);
2451 do_authenticated2(Authctxt *authctxt)
2453 server_loop2(authctxt);
2457 do_cleanup(Authctxt *authctxt)
2459 static int called = 0;
2461 debug("do_cleanup");
2463 /* no cleanup if we're in the child for login shell */
2467 /* avoid double cleanup */
2472 if (authctxt == NULL)
2475 if (options.kerberos_ticket_cleanup &&
2477 krb5_cleanup_proc(authctxt);
2481 if (compat20 && options.gss_cleanup_creds)
2482 ssh_gssapi_cleanup_creds();
2486 if (options.use_pam) {
2488 sshpam_thread_cleanup();
2492 /* remove agent socket */
2493 auth_sock_cleanup_proc(authctxt->pw);
2496 * Cleanup ptys/utmp only if privsep is disabled,
2497 * or if running in monitor.
2499 if (!use_privsep || mm_is_monitor())
2500 session_destroy_all(session_pty_cleanup2);