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)
999 struct passwd *pw = s->pw;
1000 #ifndef HAVE_LOGIN_CAP
1004 /* Initialize the environment. */
1006 env = xcalloc(envsize, sizeof(char *));
1011 * The Windows environment contains some setting which are
1012 * important for a running system. They must not be dropped.
1017 p = fetch_windows_environment();
1018 copy_environment(p, &env, &envsize);
1019 free_windows_environment(p);
1024 /* Allow any GSSAPI methods that we've used to alter
1025 * the childs environment as they see fit
1027 ssh_gssapi_do_child(&env, &envsize);
1030 if (!options.use_login) {
1031 /* Set basic environment. */
1032 for (i = 0; i < s->num_env; i++)
1033 child_set_env(&env, &envsize, s->env[i].name,
1036 child_set_env(&env, &envsize, "USER", pw->pw_name);
1037 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1039 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1041 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1042 #ifdef HAVE_LOGIN_CAP
1043 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1044 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1046 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1047 #else /* HAVE_LOGIN_CAP */
1048 # ifndef HAVE_CYGWIN
1050 * There's no standard path on Windows. The path contains
1051 * important components pointing to the system directories,
1052 * needed for loading shared libraries. So the path better
1053 * remains intact here.
1055 # ifdef HAVE_ETC_DEFAULT_LOGIN
1056 read_etc_default_login(&env, &envsize, pw->pw_uid);
1057 path = child_get_env(env, "PATH");
1058 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1059 if (path == NULL || *path == '\0') {
1060 child_set_env(&env, &envsize, "PATH",
1061 s->pw->pw_uid == 0 ?
1062 SUPERUSER_PATH : _PATH_STDPATH);
1064 # endif /* HAVE_CYGWIN */
1065 #endif /* HAVE_LOGIN_CAP */
1067 snprintf(buf, sizeof buf, "%.200s/%.50s",
1068 _PATH_MAILDIR, pw->pw_name);
1069 child_set_env(&env, &envsize, "MAIL", buf);
1071 /* Normal systems set SHELL by default. */
1072 child_set_env(&env, &envsize, "SHELL", shell);
1075 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1077 /* Set custom environment options from RSA authentication. */
1078 if (!options.use_login) {
1079 while (custom_environment) {
1080 struct envstring *ce = custom_environment;
1083 for (i = 0; str[i] != '=' && str[i]; i++)
1085 if (str[i] == '=') {
1087 child_set_env(&env, &envsize, str, str + i + 1);
1089 custom_environment = ce->next;
1095 /* SSH_CLIENT deprecated */
1096 snprintf(buf, sizeof buf, "%.50s %d %d",
1097 get_remote_ipaddr(), get_remote_port(), get_local_port());
1098 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1100 laddr = get_local_ipaddr(packet_get_connection_in());
1101 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1102 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1104 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1107 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1109 child_set_env(&env, &envsize, "TERM", s->term);
1111 child_set_env(&env, &envsize, "DISPLAY", s->display);
1112 if (original_command)
1113 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1117 if (cray_tmpdir[0] != '\0')
1118 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1119 #endif /* _UNICOS */
1122 * Since we clear KRB5CCNAME at startup, if it's set now then it
1123 * must have been set by a native authentication method (eg AIX or
1124 * SIA), so copy it to the child.
1129 if ((cp = getenv("KRB5CCNAME")) != NULL)
1130 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1137 if ((cp = getenv("AUTHSTATE")) != NULL)
1138 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1139 read_environment_file(&env, &envsize, "/etc/environment");
1143 if (s->authctxt->krb5_ccname)
1144 child_set_env(&env, &envsize, "KRB5CCNAME",
1145 s->authctxt->krb5_ccname);
1149 * Pull in any environment variables that may have
1152 if (options.use_pam) {
1155 p = fetch_pam_child_environment();
1156 copy_environment(p, &env, &envsize);
1157 free_pam_environment(p);
1159 p = fetch_pam_environment();
1160 copy_environment(p, &env, &envsize);
1161 free_pam_environment(p);
1163 #endif /* USE_PAM */
1165 if (auth_sock_name != NULL)
1166 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1169 /* read $HOME/.ssh/environment. */
1170 if (options.permit_user_env && !options.use_login) {
1171 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1172 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1173 read_environment_file(&env, &envsize, buf);
1176 /* dump the environment */
1177 fprintf(stderr, "Environment:\n");
1178 for (i = 0; env[i]; i++)
1179 fprintf(stderr, " %.200s\n", env[i]);
1185 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1186 * first in this order).
1189 do_rc_files(Session *s, const char *shell)
1197 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1199 /* ignore _PATH_SSH_USER_RC for subsystems */
1200 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1201 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1202 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1204 fprintf(stderr, "Running %s\n", cmd);
1205 f = popen(cmd, "w");
1208 fprintf(f, "%s %s\n", s->auth_proto,
1212 fprintf(stderr, "Could not run %s\n",
1214 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1216 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1217 _PATH_SSH_SYSTEM_RC);
1218 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1221 fprintf(f, "%s %s\n", s->auth_proto,
1225 fprintf(stderr, "Could not run %s\n",
1226 _PATH_SSH_SYSTEM_RC);
1227 } else if (do_xauth && options.xauth_location != NULL) {
1228 /* Add authority data to .Xauthority if appropriate. */
1231 "Running %.500s remove %.100s\n",
1232 options.xauth_location, s->auth_display);
1234 "%.500s add %.100s %.100s %.100s\n",
1235 options.xauth_location, s->auth_display,
1236 s->auth_proto, s->auth_data);
1238 snprintf(cmd, sizeof cmd, "%s -q -",
1239 options.xauth_location);
1240 f = popen(cmd, "w");
1242 fprintf(f, "remove %s\n",
1244 fprintf(f, "add %s %s %s\n",
1245 s->auth_display, s->auth_proto,
1249 fprintf(stderr, "Could not run %s\n",
1256 do_nologin(struct passwd *pw)
1261 #ifdef HAVE_LOGIN_CAP
1262 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1263 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1264 _PATH_NOLOGIN), "r");
1267 f = fopen(_PATH_NOLOGIN, "r");
1270 /* /etc/nologin exists. Print its contents and exit. */
1271 logit("User %.100s not allowed because %s exists",
1272 pw->pw_name, _PATH_NOLOGIN);
1273 while (fgets(buf, sizeof(buf), f))
1281 /* Set login name, uid, gid, and groups. */
1283 do_setusercontext(struct passwd *pw)
1286 if (getuid() == 0 || geteuid() == 0)
1287 #endif /* HAVE_CYGWIN */
1290 #ifdef HAVE_SETPCRED
1291 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1292 fatal("Failed to set process credentials");
1293 #endif /* HAVE_SETPCRED */
1294 #ifdef HAVE_LOGIN_CAP
1299 if (options.gss_authentication) {
1300 temporarily_use_uid(pw);
1301 ssh_gssapi_storecreds();
1306 if (options.use_pam) {
1310 # endif /* USE_PAM */
1311 if (setusercontext(lc, pw, pw->pw_uid,
1312 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1313 perror("unable to set user context");
1317 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1318 /* Sets login uid for accounting */
1319 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1320 error("setluid: %s", strerror(errno));
1321 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1323 if (setlogin(pw->pw_name) < 0)
1324 error("setlogin failed: %s", strerror(errno));
1325 if (setgid(pw->pw_gid) < 0) {
1329 /* Initialize the group list. */
1330 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1331 perror("initgroups");
1336 if (options.gss_authentication) {
1337 temporarily_use_uid(pw);
1338 ssh_gssapi_storecreds();
1344 * PAM credentials may take the form of supplementary groups.
1345 * These will have been wiped by the above initgroups() call.
1346 * Reestablish them here.
1348 if (options.use_pam) {
1352 # endif /* USE_PAM */
1353 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1354 irix_setusercontext(pw);
1355 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1359 #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
1360 if (set_id(pw->pw_name) != 0) {
1363 #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
1364 /* Permanently switch to the desired uid. */
1365 permanently_set_uid(pw);
1372 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1373 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1376 ssh_selinux_setup_exec_context(pw->pw_name);
1381 do_pwchange(Session *s)
1384 fprintf(stderr, "WARNING: Your password has expired.\n");
1385 if (s->ttyfd != -1) {
1387 "You must change your password now and login again!\n");
1388 #ifdef PASSWD_NEEDS_USERNAME
1389 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1392 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1397 "Password change required but no TTY available.\n");
1403 launch_login(struct passwd *pw, const char *hostname)
1405 /* Launch login(1). */
1407 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1408 #ifdef xxxLOGIN_NEEDS_TERM
1409 (s->term ? s->term : "unknown"),
1410 #endif /* LOGIN_NEEDS_TERM */
1411 #ifdef LOGIN_NO_ENDOPT
1412 "-p", "-f", pw->pw_name, (char *)NULL);
1414 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1417 /* Login couldn't be executed, die. */
1424 child_close_fds(void)
1428 if (packet_get_connection_in() == packet_get_connection_out())
1429 close(packet_get_connection_in());
1431 close(packet_get_connection_in());
1432 close(packet_get_connection_out());
1435 * Close all descriptors related to channels. They will still remain
1436 * open in the parent.
1438 /* XXX better use close-on-exec? -markus */
1439 channel_close_all();
1442 * Close any extra file descriptors. Note that there may still be
1443 * descriptors left by system functions. They will be closed later.
1448 * Close any extra open file descriptors so that we don't have them
1449 * hanging around in clients. Note that we want to do this after
1450 * initgroups, because at least on Solaris 2.3 it leaves file
1453 for (i = 3; i < 64; i++)
1458 * Performs common processing for the child, such as setting up the
1459 * environment, closing extra file descriptors, setting the user and group
1460 * ids, and executing the command or shell.
1463 do_child(Session *s, const char *command)
1465 extern char **environ;
1468 const char *shell, *shell0, *hostname = NULL;
1469 struct passwd *pw = s->pw;
1471 /* remove hostkey from the child's memory */
1472 destroy_sensitive_data();
1474 /* Force a password change */
1475 if (s->authctxt->force_pwchange) {
1476 do_setusercontext(pw);
1482 /* login(1) is only called if we execute the login shell */
1483 if (options.use_login && command != NULL)
1484 options.use_login = 0;
1487 cray_setup(pw->pw_uid, pw->pw_name, command);
1488 #endif /* _UNICOS */
1491 * Login(1) does this as well, and it needs uid 0 for the "-h"
1492 * switch, so we let login(1) to this for us.
1494 if (!options.use_login) {
1496 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1497 if (!check_quietlogin(s, command))
1499 #else /* HAVE_OSF_SIA */
1500 /* When PAM is enabled we rely on it to do the nologin check */
1501 if (!options.use_pam)
1503 do_setusercontext(pw);
1505 * PAM session modules in do_setusercontext may have
1506 * generated messages, so if this in an interactive
1507 * login then display them too.
1509 if (!check_quietlogin(s, command))
1511 #endif /* HAVE_OSF_SIA */
1515 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1516 debug3("PAM session not opened, exiting");
1523 * Get the shell from the password data. An empty shell field is
1524 * legal, and means /bin/sh.
1526 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1529 * Make sure $SHELL points to the shell from the password file,
1530 * even if shell is overridden from login.conf
1532 env = do_setup_env(s, shell);
1534 #ifdef HAVE_LOGIN_CAP
1535 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1538 /* we have to stash the hostname before we close our socket. */
1539 if (options.use_login)
1540 hostname = get_remote_name_or_ip(utmp_len,
1543 * Close the connection descriptors; note that this is the child, and
1544 * the server will still have the socket open, and it is important
1545 * that we do not shutdown it. Note that the descriptors cannot be
1546 * closed before building the environment, as we call
1547 * get_remote_ipaddr there.
1552 * Must take new environment into use so that .ssh/rc,
1553 * /etc/ssh/sshrc and xauth are run in the proper environment.
1557 #if defined(KRB5) && defined(USE_AFS)
1559 * At this point, we check to see if AFS is active and if we have
1560 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1561 * if we can (and need to) extend the ticket into an AFS token. If
1562 * we don't do this, we run into potential problems if the user's
1563 * home directory is in AFS and it's not world-readable.
1566 if (options.kerberos_get_afs_token && k_hasafs() &&
1567 (s->authctxt->krb5_ctx != NULL)) {
1570 debug("Getting AFS token");
1574 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1575 krb5_afslog(s->authctxt->krb5_ctx,
1576 s->authctxt->krb5_fwd_ccache, cell, NULL);
1578 krb5_afslog_home(s->authctxt->krb5_ctx,
1579 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1583 /* Change current directory to the user's home directory. */
1584 if (chdir(pw->pw_dir) < 0) {
1585 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1586 pw->pw_dir, strerror(errno));
1587 #ifdef HAVE_LOGIN_CAP
1588 if (login_getcapbool(lc, "requirehome", 0))
1593 if (!options.use_login)
1594 do_rc_files(s, shell);
1596 /* restore SIGPIPE for child */
1597 signal(SIGPIPE, SIG_DFL);
1599 if (options.use_login) {
1600 launch_login(pw, hostname);
1604 /* Get the last component of the shell name. */
1605 if ((shell0 = strrchr(shell, '/')) != NULL)
1611 * If we have no command, execute the shell. In this case, the shell
1612 * name to be passed in argv[0] is preceded by '-' to indicate that
1613 * this is a login shell.
1618 /* Start the shell. Set initial character to '-'. */
1621 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1622 >= sizeof(argv0) - 1) {
1628 /* Execute the shell. */
1631 execve(shell, argv, env);
1633 /* Executing the shell failed. */
1638 * Execute the command using the user's shell. This uses the -c
1639 * option to execute the command.
1641 argv[0] = (char *) shell0;
1643 argv[2] = (char *) command;
1645 execve(shell, argv, env);
1654 static int did_init = 0;
1656 debug("session_new: init");
1657 for (i = 0; i < MAX_SESSIONS; i++) {
1658 sessions[i].used = 0;
1662 for (i = 0; i < MAX_SESSIONS; i++) {
1663 Session *s = &sessions[i];
1665 memset(s, 0, sizeof(*s));
1671 s->x11_chanids = NULL;
1672 debug("session_new: session %d", i);
1683 for (i = 0; i < MAX_SESSIONS; i++) {
1684 Session *s = &sessions[i];
1685 debug("dump: used %d session %d %p channel %d pid %ld",
1695 session_open(Authctxt *authctxt, int chanid)
1697 Session *s = session_new();
1698 debug("session_open: channel %d", chanid);
1700 error("no more sessions");
1703 s->authctxt = authctxt;
1704 s->pw = authctxt->pw;
1705 if (s->pw == NULL || !authctxt->valid)
1706 fatal("no user for session %d", s->self);
1707 debug("session_open: session %d: link with channel %d", s->self, chanid);
1713 session_by_tty(char *tty)
1716 for (i = 0; i < MAX_SESSIONS; i++) {
1717 Session *s = &sessions[i];
1718 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1719 debug("session_by_tty: session %d tty %s", i, tty);
1723 debug("session_by_tty: unknown tty %.100s", tty);
1729 session_by_channel(int id)
1732 for (i = 0; i < MAX_SESSIONS; i++) {
1733 Session *s = &sessions[i];
1734 if (s->used && s->chanid == id) {
1735 debug("session_by_channel: session %d channel %d", i, id);
1739 debug("session_by_channel: unknown channel %d", id);
1745 session_by_x11_channel(int id)
1749 for (i = 0; i < MAX_SESSIONS; i++) {
1750 Session *s = &sessions[i];
1752 if (s->x11_chanids == NULL || !s->used)
1754 for (j = 0; s->x11_chanids[j] != -1; j++) {
1755 if (s->x11_chanids[j] == id) {
1756 debug("session_by_x11_channel: session %d "
1757 "channel %d", s->self, id);
1762 debug("session_by_x11_channel: unknown channel %d", id);
1768 session_by_pid(pid_t pid)
1771 debug("session_by_pid: pid %ld", (long)pid);
1772 for (i = 0; i < MAX_SESSIONS; i++) {
1773 Session *s = &sessions[i];
1774 if (s->used && s->pid == pid)
1777 error("session_by_pid: unknown pid %ld", (long)pid);
1783 session_window_change_req(Session *s)
1785 s->col = packet_get_int();
1786 s->row = packet_get_int();
1787 s->xpixel = packet_get_int();
1788 s->ypixel = packet_get_int();
1790 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1795 session_pty_req(Session *s)
1801 debug("Allocating a pty not permitted for this authentication.");
1804 if (s->ttyfd != -1) {
1805 packet_disconnect("Protocol error: you already have a pty.");
1809 s->term = packet_get_string(&len);
1812 s->col = packet_get_int();
1813 s->row = packet_get_int();
1815 s->row = packet_get_int();
1816 s->col = packet_get_int();
1818 s->xpixel = packet_get_int();
1819 s->ypixel = packet_get_int();
1821 if (strcmp(s->term, "") == 0) {
1826 /* Allocate a pty and open it. */
1827 debug("Allocating pty.");
1828 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1834 error("session_pty_req: session %d alloc failed", s->self);
1837 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1839 /* for SSH1 the tty modes length is not given */
1841 n_bytes = packet_remaining();
1842 tty_parse_modes(s->ttyfd, &n_bytes);
1845 pty_setowner(s->pw, s->tty);
1847 /* Set window size from the packet. */
1848 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1851 session_proctitle(s);
1856 session_subsystem_req(Session *s)
1861 char *prog, *cmd, *subsys = packet_get_string(&len);
1865 logit("subsystem request for %.100s", subsys);
1867 for (i = 0; i < options.num_subsystems; i++) {
1868 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1869 prog = options.subsystem_command[i];
1870 cmd = options.subsystem_args[i];
1871 if (stat(prog, &st) < 0) {
1872 error("subsystem: cannot stat %s: %s", prog,
1876 debug("subsystem: exec() %s", cmd);
1877 s->is_subsystem = 1;
1885 logit("subsystem request for %.100s failed, subsystem not found",
1893 session_x11_req(Session *s)
1897 if (s->auth_proto != NULL || s->auth_data != NULL) {
1898 error("session_x11_req: session %d: "
1899 "x11 forwarding already active", s->self);
1902 s->single_connection = packet_get_char();
1903 s->auth_proto = packet_get_string(NULL);
1904 s->auth_data = packet_get_string(NULL);
1905 s->screen = packet_get_int();
1908 success = session_setup_x11fwd(s);
1910 xfree(s->auth_proto);
1911 xfree(s->auth_data);
1912 s->auth_proto = NULL;
1913 s->auth_data = NULL;
1919 session_shell_req(Session *s)
1927 session_exec_req(Session *s)
1930 char *command = packet_get_string(&len);
1932 do_exec(s, command);
1938 session_break_req(Session *s)
1941 packet_get_int(); /* ignored */
1944 if (s->ttyfd == -1 ||
1945 tcsendbreak(s->ttyfd, 0) < 0)
1951 session_env_req(Session *s)
1954 u_int name_len, val_len, i;
1956 name = packet_get_string(&name_len);
1957 val = packet_get_string(&val_len);
1960 /* Don't set too many environment variables */
1961 if (s->num_env > 128) {
1962 debug2("Ignoring env request %s: too many env vars", name);
1966 for (i = 0; i < options.num_accept_env; i++) {
1967 if (match_pattern(name, options.accept_env[i])) {
1968 debug2("Setting env %d: %s=%s", s->num_env, name, val);
1969 s->env = xrealloc(s->env, s->num_env + 1,
1971 s->env[s->num_env].name = name;
1972 s->env[s->num_env].val = val;
1977 debug2("Ignoring env request %s: disallowed name", name);
1986 session_auth_agent_req(Session *s)
1988 static int called = 0;
1990 if (no_agent_forwarding_flag) {
1991 debug("session_auth_agent_req: no_agent_forwarding_flag");
1998 return auth_input_request_forwarding(s->pw);
2003 session_input_channel_req(Channel *c, const char *rtype)
2008 if ((s = session_by_channel(c->self)) == NULL) {
2009 logit("session_input_channel_req: no session %d req %.100s",
2013 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2016 * a session is in LARVAL state until a shell, a command
2017 * or a subsystem is executed
2019 if (c->type == SSH_CHANNEL_LARVAL) {
2020 if (strcmp(rtype, "shell") == 0) {
2021 success = session_shell_req(s);
2022 } else if (strcmp(rtype, "exec") == 0) {
2023 success = session_exec_req(s);
2024 } else if (strcmp(rtype, "pty-req") == 0) {
2025 success = session_pty_req(s);
2026 } else if (strcmp(rtype, "x11-req") == 0) {
2027 success = session_x11_req(s);
2028 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2029 success = session_auth_agent_req(s);
2030 } else if (strcmp(rtype, "subsystem") == 0) {
2031 success = session_subsystem_req(s);
2032 } else if (strcmp(rtype, "env") == 0) {
2033 success = session_env_req(s);
2036 if (strcmp(rtype, "window-change") == 0) {
2037 success = session_window_change_req(s);
2038 } else if (strcmp(rtype, "break") == 0) {
2039 success = session_break_req(s);
2046 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2049 fatal("session_set_fds: called for proto != 2.0");
2051 * now that have a child and a pipe to the child,
2052 * we can activate our channel and register the fd's
2054 if (s->chanid == -1)
2055 fatal("no channel for session %d", s->self);
2056 channel_set_fds(s->chanid,
2058 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2060 CHAN_SES_WINDOW_DEFAULT);
2064 * Function to perform pty cleanup. Also called if we get aborted abnormally
2065 * (e.g., due to a dropped connection).
2068 session_pty_cleanup2(Session *s)
2071 error("session_pty_cleanup: no session");
2077 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2079 /* Record that the user has logged out. */
2081 record_logout(s->pid, s->tty, s->pw->pw_name);
2083 /* Release the pseudo-tty. */
2085 pty_release(s->tty);
2088 * Close the server side of the socket pairs. We must do this after
2089 * the pty cleanup, so that another process doesn't get this pty
2090 * while we're still cleaning up.
2092 if (close(s->ptymaster) < 0)
2093 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2095 /* unlink pty from session */
2100 session_pty_cleanup(Session *s)
2102 PRIVSEP(session_pty_cleanup2(s));
2108 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2123 return "SIG@openssh.com";
2127 session_close_x11(int id)
2131 if ((c = channel_by_id(id)) == NULL) {
2132 debug("session_close_x11: x11 channel %d missing", id);
2134 /* Detach X11 listener */
2135 debug("session_close_x11: detach x11 channel %d", id);
2136 channel_cancel_cleanup(id);
2137 if (c->ostate != CHAN_OUTPUT_CLOSED)
2143 session_close_single_x11(int id, void *arg)
2148 debug3("session_close_single_x11: channel %d", id);
2149 channel_cancel_cleanup(id);
2150 if ((s = session_by_x11_channel(id)) == NULL)
2151 fatal("session_close_single_x11: no x11 channel %d", id);
2152 for (i = 0; s->x11_chanids[i] != -1; i++) {
2153 debug("session_close_single_x11: session %d: "
2154 "closing channel %d", s->self, s->x11_chanids[i]);
2156 * The channel "id" is already closing, but make sure we
2157 * close all of its siblings.
2159 if (s->x11_chanids[i] != id)
2160 session_close_x11(s->x11_chanids[i]);
2162 xfree(s->x11_chanids);
2163 s->x11_chanids = NULL;
2168 if (s->auth_proto) {
2169 xfree(s->auth_proto);
2170 s->auth_proto = NULL;
2173 xfree(s->auth_data);
2174 s->auth_data = NULL;
2176 if (s->auth_display) {
2177 xfree(s->auth_display);
2178 s->auth_display = NULL;
2183 session_exit_message(Session *s, int status)
2187 if ((c = channel_lookup(s->chanid)) == NULL)
2188 fatal("session_exit_message: session %d: no channel %d",
2189 s->self, s->chanid);
2190 debug("session_exit_message: session %d channel %d pid %ld",
2191 s->self, s->chanid, (long)s->pid);
2193 if (WIFEXITED(status)) {
2194 channel_request_start(s->chanid, "exit-status", 0);
2195 packet_put_int(WEXITSTATUS(status));
2197 } else if (WIFSIGNALED(status)) {
2198 channel_request_start(s->chanid, "exit-signal", 0);
2199 packet_put_cstring(sig2name(WTERMSIG(status)));
2201 packet_put_char(WCOREDUMP(status));
2202 #else /* WCOREDUMP */
2204 #endif /* WCOREDUMP */
2205 packet_put_cstring("");
2206 packet_put_cstring("");
2209 /* Some weird exit cause. Just exit. */
2210 packet_disconnect("wait returned status %04x.", status);
2213 /* disconnect channel */
2214 debug("session_exit_message: release channel %d", s->chanid);
2217 * Adjust cleanup callback attachment to send close messages when
2218 * the channel gets EOF. The session will be then be closed
2219 * by session_close_by_channel when the childs close their fds.
2221 channel_register_cleanup(c->self, session_close_by_channel, 1);
2224 * emulate a write failure with 'chan_write_failed', nobody will be
2225 * interested in data we write.
2226 * Note that we must not call 'chan_read_failed', since there could
2227 * be some more data waiting in the pipe.
2229 if (c->ostate != CHAN_OUTPUT_CLOSED)
2230 chan_write_failed(c);
2234 session_close(Session *s)
2238 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2240 session_pty_cleanup(s);
2246 xfree(s->x11_chanids);
2247 if (s->auth_display)
2248 xfree(s->auth_display);
2250 xfree(s->auth_data);
2252 xfree(s->auth_proto);
2254 for (i = 0; i < s->num_env; i++) {
2255 xfree(s->env[i].name);
2256 xfree(s->env[i].val);
2260 session_proctitle(s);
2264 session_close_by_pid(pid_t pid, int status)
2266 Session *s = session_by_pid(pid);
2268 debug("session_close_by_pid: no session for pid %ld",
2272 if (s->chanid != -1)
2273 session_exit_message(s, status);
2275 session_pty_cleanup(s);
2280 * this is called when a channel dies before
2281 * the session 'child' itself dies
2284 session_close_by_channel(int id, void *arg)
2286 Session *s = session_by_channel(id);
2290 debug("session_close_by_channel: no session for id %d", id);
2293 debug("session_close_by_channel: channel %d child %ld",
2296 debug("session_close_by_channel: channel %d: has child", id);
2298 * delay detach of session, but release pty, since
2299 * the fd's to the child are already closed
2302 session_pty_cleanup(s);
2305 /* detach by removing callback */
2306 channel_cancel_cleanup(s->chanid);
2308 /* Close any X11 listeners associated with this session */
2309 if (s->x11_chanids != NULL) {
2310 for (i = 0; s->x11_chanids[i] != -1; i++) {
2311 session_close_x11(s->x11_chanids[i]);
2312 s->x11_chanids[i] = -1;
2321 session_destroy_all(void (*closefunc)(Session *))
2324 for (i = 0; i < MAX_SESSIONS; i++) {
2325 Session *s = &sessions[i];
2327 if (closefunc != NULL)
2336 session_tty_list(void)
2338 static char buf[1024];
2343 for (i = 0; i < MAX_SESSIONS; i++) {
2344 Session *s = &sessions[i];
2345 if (s->used && s->ttyfd != -1) {
2347 if (strncmp(s->tty, "/dev/", 5) != 0) {
2348 cp = strrchr(s->tty, '/');
2349 cp = (cp == NULL) ? s->tty : cp + 1;
2354 strlcat(buf, ",", sizeof buf);
2355 strlcat(buf, cp, sizeof buf);
2359 strlcpy(buf, "notty", sizeof buf);
2364 session_proctitle(Session *s)
2367 error("no user for session %d", s->self);
2369 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2373 session_setup_x11fwd(Session *s)
2376 char display[512], auth_display[512];
2377 char hostname[MAXHOSTNAMELEN];
2380 if (no_x11_forwarding_flag) {
2381 packet_send_debug("X11 forwarding disabled in user configuration file.");
2384 if (!options.x11_forwarding) {
2385 debug("X11 forwarding disabled in server configuration file.");
2388 if (!options.xauth_location ||
2389 (stat(options.xauth_location, &st) == -1)) {
2390 packet_send_debug("No xauth program; cannot forward with spoofing.");
2393 if (options.use_login) {
2394 packet_send_debug("X11 forwarding disabled; "
2395 "not compatible with UseLogin=yes.");
2398 if (s->display != NULL) {
2399 debug("X11 display already set.");
2402 if (x11_create_display_inet(options.x11_display_offset,
2403 options.x11_use_localhost, s->single_connection,
2404 &s->display_number, &s->x11_chanids) == -1) {
2405 debug("x11_create_display_inet failed.");
2408 for (i = 0; s->x11_chanids[i] != -1; i++) {
2409 channel_register_cleanup(s->x11_chanids[i],
2410 session_close_single_x11, 0);
2413 /* Set up a suitable value for the DISPLAY variable. */
2414 if (gethostname(hostname, sizeof(hostname)) < 0)
2415 fatal("gethostname: %.100s", strerror(errno));
2417 * auth_display must be used as the displayname when the
2418 * authorization entry is added with xauth(1). This will be
2419 * different than the DISPLAY string for localhost displays.
2421 if (options.x11_use_localhost) {
2422 snprintf(display, sizeof display, "localhost:%u.%u",
2423 s->display_number, s->screen);
2424 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2425 s->display_number, s->screen);
2426 s->display = xstrdup(display);
2427 s->auth_display = xstrdup(auth_display);
2429 #ifdef IPADDR_IN_DISPLAY
2431 struct in_addr my_addr;
2433 he = gethostbyname(hostname);
2435 error("Can't get IP address for X11 DISPLAY.");
2436 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2439 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2440 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2441 s->display_number, s->screen);
2443 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2444 s->display_number, s->screen);
2446 s->display = xstrdup(display);
2447 s->auth_display = xstrdup(display);
2454 do_authenticated2(Authctxt *authctxt)
2456 server_loop2(authctxt);
2460 do_cleanup(Authctxt *authctxt)
2462 static int called = 0;
2464 debug("do_cleanup");
2466 /* no cleanup if we're in the child for login shell */
2470 /* avoid double cleanup */
2475 if (authctxt == NULL)
2478 if (options.kerberos_ticket_cleanup &&
2480 krb5_cleanup_proc(authctxt);
2484 if (compat20 && options.gss_cleanup_creds)
2485 ssh_gssapi_cleanup_creds();
2489 if (options.use_pam) {
2491 sshpam_thread_cleanup();
2495 /* remove agent socket */
2496 auth_sock_cleanup_proc(authctxt->pw);
2499 * Cleanup ptys/utmp only if privsep is disabled,
2500 * or if running in monitor.
2502 if (!use_privsep || mm_is_monitor())
2503 session_destroy_all(session_pty_cleanup2);