1 /* $OpenBSD: session.c,v 1.210 2006/07/19 13:07:10 dtucker 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>
53 #include <arpa/inet.h>
68 #include "auth-options.h"
69 #include "pathnames.h"
73 #include "serverloop.h"
77 #include "monitor_wrap.h"
79 #if defined(KRB5) && defined(USE_AFS)
89 Session *session_new(void);
90 void session_set_fds(Session *, int, int, int);
91 void session_pty_cleanup(Session *);
92 void session_proctitle(Session *);
93 int session_setup_x11fwd(Session *);
94 void do_exec_pty(Session *, const char *);
95 void do_exec_no_pty(Session *, const char *);
96 void do_exec(Session *, const char *);
97 void do_login(Session *, const char *);
98 #ifdef LOGIN_NEEDS_UTMPX
99 static void do_pre_login(Session *s);
101 void do_child(Session *, const char *);
103 int check_quietlogin(Session *, const char *);
105 static void do_authenticated1(Authctxt *);
106 static void do_authenticated2(Authctxt *);
108 static int session_pty_req(Session *);
111 extern ServerOptions options;
112 extern char *__progname;
113 extern int log_stderr;
114 extern int debug_flag;
115 extern u_int utmp_len;
116 extern int startup_pipe;
117 extern void destroy_sensitive_data(void);
118 extern Buffer loginmsg;
120 /* original command from peer. */
121 const char *original_command = NULL;
124 #define MAX_SESSIONS 10
125 Session sessions[MAX_SESSIONS];
127 #ifdef HAVE_LOGIN_CAP
131 static int is_child = 0;
133 /* Name and directory of socket for authentication agent forwarding. */
134 static char *auth_sock_name = NULL;
135 static char *auth_sock_dir = NULL;
137 /* removes the agent forwarding socket */
140 auth_sock_cleanup_proc(struct passwd *pw)
142 if (auth_sock_name != NULL) {
143 temporarily_use_uid(pw);
144 unlink(auth_sock_name);
145 rmdir(auth_sock_dir);
146 auth_sock_name = NULL;
152 auth_input_request_forwarding(struct passwd * pw)
156 struct sockaddr_un sunaddr;
158 if (auth_sock_name != NULL) {
159 error("authentication forwarding requested twice.");
163 /* Temporarily drop privileged uid for mkdir/bind. */
164 temporarily_use_uid(pw);
166 /* Allocate a buffer for the socket name, and format the name. */
167 auth_sock_name = xmalloc(MAXPATHLEN);
168 auth_sock_dir = xmalloc(MAXPATHLEN);
169 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
171 /* Create private directory for socket */
172 if (mkdtemp(auth_sock_dir) == NULL) {
173 packet_send_debug("Agent forwarding disabled: "
174 "mkdtemp() failed: %.100s", strerror(errno));
176 xfree(auth_sock_name);
177 xfree(auth_sock_dir);
178 auth_sock_name = NULL;
179 auth_sock_dir = NULL;
182 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
183 auth_sock_dir, (long) getpid());
185 /* Create the socket. */
186 sock = socket(AF_UNIX, SOCK_STREAM, 0);
188 packet_disconnect("socket: %.100s", strerror(errno));
190 /* Bind it to the name. */
191 memset(&sunaddr, 0, sizeof(sunaddr));
192 sunaddr.sun_family = AF_UNIX;
193 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
195 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0)
196 packet_disconnect("bind: %.100s", strerror(errno));
198 /* Restore the privileged uid. */
201 /* Start listening on the socket. */
202 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
203 packet_disconnect("listen: %.100s", strerror(errno));
205 /* Allocate a channel for the authentication agent socket. */
206 nc = channel_new("auth socket",
207 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
208 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
209 0, "auth socket", 1);
210 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
215 display_loginmsg(void)
217 if (buffer_len(&loginmsg) > 0) {
218 buffer_append(&loginmsg, "\0", 1);
219 printf("%s", (char *)buffer_ptr(&loginmsg));
220 buffer_clear(&loginmsg);
225 do_authenticated(Authctxt *authctxt)
227 setproctitle("%s", authctxt->pw->pw_name);
229 /* setup the channel layer */
230 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
231 channel_permit_all_opens();
234 do_authenticated2(authctxt);
236 do_authenticated1(authctxt);
238 do_cleanup(authctxt);
242 * Prepares for an interactive session. This is called after the user has
243 * been successfully authenticated. During this message exchange, pseudo
244 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
245 * are requested, etc.
248 do_authenticated1(Authctxt *authctxt)
252 int success, type, screen_flag;
253 int enable_compression_after_reply = 0;
254 u_int proto_len, data_len, dlen, compression_level = 0;
258 error("no more sessions");
261 s->authctxt = authctxt;
262 s->pw = authctxt->pw;
265 * We stay in this loop until the client requests to execute a shell
271 /* Get a packet from the client. */
272 type = packet_read();
274 /* Process the packet. */
276 case SSH_CMSG_REQUEST_COMPRESSION:
277 compression_level = packet_get_int();
279 if (compression_level < 1 || compression_level > 9) {
280 packet_send_debug("Received invalid compression level %d.",
284 if (options.compression == COMP_NONE) {
285 debug2("compression disabled");
288 /* Enable compression after we have responded with SUCCESS. */
289 enable_compression_after_reply = 1;
293 case SSH_CMSG_REQUEST_PTY:
294 success = session_pty_req(s);
297 case SSH_CMSG_X11_REQUEST_FORWARDING:
298 s->auth_proto = packet_get_string(&proto_len);
299 s->auth_data = packet_get_string(&data_len);
301 screen_flag = packet_get_protocol_flags() &
302 SSH_PROTOFLAG_SCREEN_NUMBER;
303 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
305 if (packet_remaining() == 4) {
307 debug2("Buggy client: "
308 "X11 screen flag missing");
309 s->screen = packet_get_int();
314 success = session_setup_x11fwd(s);
316 xfree(s->auth_proto);
318 s->auth_proto = NULL;
323 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
324 if (no_agent_forwarding_flag || compat13) {
325 debug("Authentication agent forwarding not permitted for this authentication.");
328 debug("Received authentication agent forwarding request.");
329 success = auth_input_request_forwarding(s->pw);
332 case SSH_CMSG_PORT_FORWARD_REQUEST:
333 if (no_port_forwarding_flag) {
334 debug("Port forwarding not permitted for this authentication.");
337 if (!options.allow_tcp_forwarding) {
338 debug("Port forwarding not permitted.");
341 debug("Received TCP/IP port forwarding request.");
342 if (channel_input_port_forward_request(s->pw->pw_uid == 0,
343 options.gateway_ports) < 0) {
344 debug("Port forwarding failed.");
350 case SSH_CMSG_MAX_PACKET_SIZE:
351 if (packet_set_maxsize(packet_get_int()) > 0)
355 case SSH_CMSG_EXEC_SHELL:
356 case SSH_CMSG_EXEC_CMD:
357 if (type == SSH_CMSG_EXEC_CMD) {
358 command = packet_get_string(&dlen);
359 debug("Exec command '%.500s'", command);
371 * Any unknown messages in this phase are ignored,
372 * and a failure message is returned.
374 logit("Unknown packet type received after authentication: %d", type);
376 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
380 /* Enable compression now that we have replied if appropriate. */
381 if (enable_compression_after_reply) {
382 enable_compression_after_reply = 0;
383 packet_start_compression(compression_level);
389 * This is called to fork and execute a command when we have no tty. This
390 * will call do_child from the child, and server_loop from the parent after
391 * setting up file descriptors and such.
394 do_exec_no_pty(Session *s, const char *command)
399 int pin[2], pout[2], perr[2];
400 /* Allocate pipes for communicating with the program. */
401 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
402 packet_disconnect("Could not create pipes: %.100s",
404 #else /* USE_PIPES */
405 int inout[2], err[2];
406 /* Uses socket pairs to communicate with the program. */
407 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
408 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
409 packet_disconnect("Could not create socket pairs: %.100s",
411 #endif /* USE_PIPES */
413 fatal("do_exec_no_pty: no session");
415 session_proctitle(s);
418 if (options.use_pam && !use_privsep)
422 /* Fork the child. */
423 if ((pid = fork()) == 0) {
426 /* Child. Reinitialize the log since the pid has changed. */
427 log_init(__progname, options.log_level, options.log_facility, log_stderr);
430 * Create a new session and process group since the 4.4BSD
431 * setlogin() affects the entire process group.
434 error("setsid failed: %.100s", strerror(errno));
438 * Redirect stdin. We close the parent side of the socket
439 * pair, and make the child side the standard input.
442 if (dup2(pin[0], 0) < 0)
443 perror("dup2 stdin");
446 /* Redirect stdout. */
448 if (dup2(pout[1], 1) < 0)
449 perror("dup2 stdout");
452 /* Redirect stderr. */
454 if (dup2(perr[1], 2) < 0)
455 perror("dup2 stderr");
457 #else /* USE_PIPES */
459 * Redirect stdin, stdout, and stderr. Stdin and stdout will
460 * use the same socket, as some programs (particularly rdist)
461 * seem to depend on it.
465 if (dup2(inout[0], 0) < 0) /* stdin */
466 perror("dup2 stdin");
467 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
468 perror("dup2 stdout");
469 if (dup2(err[0], 2) < 0) /* stderr */
470 perror("dup2 stderr");
471 #endif /* USE_PIPES */
474 cray_init_job(s->pw); /* set up cray jid and tmpdir */
477 /* Do processing for the child (exec command etc). */
478 do_child(s, command);
482 signal(WJSIGNAL, cray_job_termination_handler);
486 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
489 packet_disconnect("fork failed: %.100s", strerror(errno));
491 /* Set interactive/non-interactive mode. */
492 packet_set_interactive(s->display != NULL);
494 /* We are the parent. Close the child sides of the pipes. */
500 if (s->is_subsystem) {
504 session_set_fds(s, pin[1], pout[0], perr[0]);
506 /* Enter the interactive session. */
507 server_loop(pid, pin[1], pout[0], perr[0]);
508 /* server_loop has closed pin[1], pout[0], and perr[0]. */
510 #else /* USE_PIPES */
511 /* We are the parent. Close the child sides of the socket pairs. */
516 * Clear loginmsg, since it's the child's responsibility to display
517 * it to the user, otherwise multiple sessions may accumulate
518 * multiple copies of the login messages.
520 buffer_clear(&loginmsg);
523 * Enter the interactive session. Note: server_loop must be able to
524 * handle the case that fdin and fdout are the same.
527 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
529 server_loop(pid, inout[1], inout[1], err[1]);
530 /* server_loop has closed inout[1] and err[1]. */
532 #endif /* USE_PIPES */
536 * This is called to fork and execute a command when we have a tty. This
537 * will call do_child from the child, and server_loop from the parent after
538 * setting up file descriptors, controlling tty, updating wtmp, utmp,
539 * lastlog, and other such operations.
542 do_exec_pty(Session *s, const char *command)
544 int fdout, ptyfd, ttyfd, ptymaster;
548 fatal("do_exec_pty: no session");
553 if (options.use_pam) {
554 do_pam_set_tty(s->tty);
560 /* Fork the child. */
561 if ((pid = fork()) == 0) {
564 /* Child. Reinitialize the log because the pid has changed. */
565 log_init(__progname, options.log_level, options.log_facility, log_stderr);
566 /* Close the master side of the pseudo tty. */
569 /* Make the pseudo tty our controlling tty. */
570 pty_make_controlling_tty(&ttyfd, s->tty);
572 /* Redirect stdin/stdout/stderr from the pseudo tty. */
573 if (dup2(ttyfd, 0) < 0)
574 error("dup2 stdin: %s", strerror(errno));
575 if (dup2(ttyfd, 1) < 0)
576 error("dup2 stdout: %s", strerror(errno));
577 if (dup2(ttyfd, 2) < 0)
578 error("dup2 stderr: %s", strerror(errno));
580 /* Close the extra descriptor for the pseudo tty. */
583 /* record login, etc. similar to login(1) */
585 if (!(options.use_login && command == NULL)) {
587 cray_init_job(s->pw); /* set up cray jid and tmpdir */
589 do_login(s, command);
591 # ifdef LOGIN_NEEDS_UTMPX
597 /* Do common processing for the child, such as execing the command. */
598 do_child(s, command);
602 signal(WJSIGNAL, cray_job_termination_handler);
606 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
609 packet_disconnect("fork failed: %.100s", strerror(errno));
612 /* Parent. Close the slave side of the pseudo tty. */
616 * Create another descriptor of the pty master side for use as the
617 * standard input. We could use the original descriptor, but this
618 * simplifies code in server_loop. The descriptor is bidirectional.
622 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
624 /* we keep a reference to the pty master */
625 ptymaster = dup(ptyfd);
627 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
628 s->ptymaster = ptymaster;
630 /* Enter interactive session. */
631 packet_set_interactive(1);
633 session_set_fds(s, ptyfd, fdout, -1);
635 server_loop(pid, ptyfd, fdout, -1);
636 /* server_loop _has_ closed ptyfd and fdout. */
640 #ifdef LOGIN_NEEDS_UTMPX
642 do_pre_login(Session *s)
645 struct sockaddr_storage from;
646 pid_t pid = getpid();
649 * Get IP address of client. If the connection is not a socket, let
650 * the address be 0.0.0.0.
652 memset(&from, 0, sizeof(from));
653 fromlen = sizeof(from);
654 if (packet_connection_is_on_socket()) {
655 if (getpeername(packet_get_connection_in(),
656 (struct sockaddr *)&from, &fromlen) < 0) {
657 debug("getpeername: %.100s", strerror(errno));
662 record_utmp_only(pid, s->tty, s->pw->pw_name,
663 get_remote_name_or_ip(utmp_len, options.use_dns),
664 (struct sockaddr *)&from, fromlen);
669 * This is called to fork and execute a command. If another command is
670 * to be forced, execute that instead.
673 do_exec(Session *s, const char *command)
675 if (options.adm_forced_command) {
676 original_command = command;
677 command = options.adm_forced_command;
678 debug("Forced command (config) '%.900s'", command);
679 } else if (forced_command) {
680 original_command = command;
681 command = forced_command;
682 debug("Forced command (key option) '%.900s'", command);
685 #ifdef SSH_AUDIT_EVENTS
687 PRIVSEP(audit_run_command(command));
688 else if (s->ttyfd == -1) {
689 char *shell = s->pw->pw_shell;
691 if (shell[0] == '\0') /* empty shell means /bin/sh */
693 PRIVSEP(audit_run_command(shell));
698 do_exec_pty(s, command);
700 do_exec_no_pty(s, command);
702 original_command = NULL;
705 * Clear loginmsg: it's the child's responsibility to display
706 * it to the user, otherwise multiple sessions may accumulate
707 * multiple copies of the login messages.
709 buffer_clear(&loginmsg);
712 /* administrative, login(1)-like work */
714 do_login(Session *s, const char *command)
717 struct sockaddr_storage from;
718 struct passwd * pw = s->pw;
719 pid_t pid = getpid();
722 * Get IP address of client. If the connection is not a socket, let
723 * the address be 0.0.0.0.
725 memset(&from, 0, sizeof(from));
726 fromlen = sizeof(from);
727 if (packet_connection_is_on_socket()) {
728 if (getpeername(packet_get_connection_in(),
729 (struct sockaddr *) & from, &fromlen) < 0) {
730 debug("getpeername: %.100s", strerror(errno));
735 /* Record that there was a login on that tty from the remote host. */
737 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
738 get_remote_name_or_ip(utmp_len,
740 (struct sockaddr *)&from, fromlen);
744 * If password change is needed, do it now.
745 * This needs to occur before the ~/.hushlogin check.
747 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
750 s->authctxt->force_pwchange = 0;
751 /* XXX - signal [net] parent to enable forwardings */
755 if (check_quietlogin(s, command))
764 * Display the message of the day.
772 if (options.print_motd) {
773 #ifdef HAVE_LOGIN_CAP
774 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
777 f = fopen("/etc/motd", "r");
780 while (fgets(buf, sizeof(buf), f))
789 * Check for quiet login, either .hushlogin or command given.
792 check_quietlogin(Session *s, const char *command)
795 struct passwd *pw = s->pw;
798 /* Return 1 if .hushlogin exists or a command given. */
801 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
802 #ifdef HAVE_LOGIN_CAP
803 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
806 if (stat(buf, &st) >= 0)
813 * Sets the value of the given variable in the environment. If the variable
814 * already exists, its value is overriden.
817 child_set_env(char ***envp, u_int *envsizep, const char *name,
825 * If we're passed an uninitialized list, allocate a single null
826 * entry before continuing.
828 if (*envp == NULL && *envsizep == 0) {
829 *envp = xmalloc(sizeof(char *));
835 * Find the slot where the value should be stored. If the variable
836 * already exists, we reuse the slot; otherwise we append a new slot
837 * at the end of the array, expanding if necessary.
840 namelen = strlen(name);
841 for (i = 0; env[i]; i++)
842 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
845 /* Reuse the slot. */
848 /* New variable. Expand if necessary. */
850 if (i >= envsize - 1) {
852 fatal("child_set_env: too many env vars");
854 env = (*envp) = xrealloc(env, envsize, sizeof(char *));
857 /* Need to set the NULL pointer at end of array beyond the new slot. */
861 /* Allocate space and format the variable in the appropriate slot. */
862 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
863 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
867 * Reads environment variables from the given file and adds/overrides them
868 * into the environment. If the file does not exist, this does nothing.
869 * Otherwise, it must consist of empty lines, comments (line starts with '#')
870 * and assignments of the form name=value. No other forms are allowed.
873 read_environment_file(char ***env, u_int *envsize,
874 const char *filename)
881 f = fopen(filename, "r");
885 while (fgets(buf, sizeof(buf), f)) {
887 fatal("Too many lines in environment file %s", filename);
888 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
890 if (!*cp || *cp == '#' || *cp == '\n')
892 if (strchr(cp, '\n'))
893 *strchr(cp, '\n') = '\0';
894 value = strchr(cp, '=');
896 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
901 * Replace the equals sign by nul, and advance value to
906 child_set_env(env, envsize, cp, value);
911 #ifdef HAVE_ETC_DEFAULT_LOGIN
913 * Return named variable from specified environment, or NULL if not present.
916 child_get_env(char **env, const char *name)
922 for (i=0; env[i] != NULL; i++)
923 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
924 return(env[i] + len + 1);
929 * Read /etc/default/login.
930 * We pick up the PATH (or SUPATH for root) and UMASK.
933 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
935 char **tmpenv = NULL, *var;
936 u_int i, tmpenvsize = 0;
940 * We don't want to copy the whole file to the child's environment,
941 * so we use a temporary environment and copy the variables we're
944 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
950 var = child_get_env(tmpenv, "SUPATH");
952 var = child_get_env(tmpenv, "PATH");
954 child_set_env(env, envsize, "PATH", var);
956 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
957 if (sscanf(var, "%5lo", &mask) == 1)
960 for (i = 0; tmpenv[i] != NULL; i++)
964 #endif /* HAVE_ETC_DEFAULT_LOGIN */
967 copy_environment(char **source, char ***env, u_int *envsize)
969 char *var_name, *var_val;
975 for(i = 0; source[i] != NULL; i++) {
976 var_name = xstrdup(source[i]);
977 if ((var_val = strstr(var_name, "=")) == NULL) {
983 debug3("Copy environment: %s=%s", var_name, var_val);
984 child_set_env(env, envsize, var_name, var_val);
991 do_setup_env(Session *s, const char *shell)
995 char **env, *laddr, *path = NULL;
996 struct passwd *pw = s->pw;
998 /* Initialize the environment. */
1000 env = xcalloc(envsize, sizeof(char *));
1005 * The Windows environment contains some setting which are
1006 * important for a running system. They must not be dropped.
1011 p = fetch_windows_environment();
1012 copy_environment(p, &env, &envsize);
1013 free_windows_environment(p);
1018 /* Allow any GSSAPI methods that we've used to alter
1019 * the childs environment as they see fit
1021 ssh_gssapi_do_child(&env, &envsize);
1024 if (!options.use_login) {
1025 /* Set basic environment. */
1026 for (i = 0; i < s->num_env; i++)
1027 child_set_env(&env, &envsize, s->env[i].name,
1030 child_set_env(&env, &envsize, "USER", pw->pw_name);
1031 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1033 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1035 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1036 #ifdef HAVE_LOGIN_CAP
1037 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1038 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1040 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1041 #else /* HAVE_LOGIN_CAP */
1042 # ifndef HAVE_CYGWIN
1044 * There's no standard path on Windows. The path contains
1045 * important components pointing to the system directories,
1046 * needed for loading shared libraries. So the path better
1047 * remains intact here.
1049 # ifdef HAVE_ETC_DEFAULT_LOGIN
1050 read_etc_default_login(&env, &envsize, pw->pw_uid);
1051 path = child_get_env(env, "PATH");
1052 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1053 if (path == NULL || *path == '\0') {
1054 child_set_env(&env, &envsize, "PATH",
1055 s->pw->pw_uid == 0 ?
1056 SUPERUSER_PATH : _PATH_STDPATH);
1058 # endif /* HAVE_CYGWIN */
1059 #endif /* HAVE_LOGIN_CAP */
1061 snprintf(buf, sizeof buf, "%.200s/%.50s",
1062 _PATH_MAILDIR, pw->pw_name);
1063 child_set_env(&env, &envsize, "MAIL", buf);
1065 /* Normal systems set SHELL by default. */
1066 child_set_env(&env, &envsize, "SHELL", shell);
1069 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1071 /* Set custom environment options from RSA authentication. */
1072 if (!options.use_login) {
1073 while (custom_environment) {
1074 struct envstring *ce = custom_environment;
1077 for (i = 0; str[i] != '=' && str[i]; i++)
1079 if (str[i] == '=') {
1081 child_set_env(&env, &envsize, str, str + i + 1);
1083 custom_environment = ce->next;
1089 /* SSH_CLIENT deprecated */
1090 snprintf(buf, sizeof buf, "%.50s %d %d",
1091 get_remote_ipaddr(), get_remote_port(), get_local_port());
1092 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1094 laddr = get_local_ipaddr(packet_get_connection_in());
1095 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1096 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1098 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1101 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1103 child_set_env(&env, &envsize, "TERM", s->term);
1105 child_set_env(&env, &envsize, "DISPLAY", s->display);
1106 if (original_command)
1107 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1111 if (cray_tmpdir[0] != '\0')
1112 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1113 #endif /* _UNICOS */
1116 * Since we clear KRB5CCNAME at startup, if it's set now then it
1117 * must have been set by a native authentication method (eg AIX or
1118 * SIA), so copy it to the child.
1123 if ((cp = getenv("KRB5CCNAME")) != NULL)
1124 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1131 if ((cp = getenv("AUTHSTATE")) != NULL)
1132 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1133 read_environment_file(&env, &envsize, "/etc/environment");
1137 if (s->authctxt->krb5_ccname)
1138 child_set_env(&env, &envsize, "KRB5CCNAME",
1139 s->authctxt->krb5_ccname);
1143 * Pull in any environment variables that may have
1146 if (options.use_pam) {
1149 p = fetch_pam_child_environment();
1150 copy_environment(p, &env, &envsize);
1151 free_pam_environment(p);
1153 p = fetch_pam_environment();
1154 copy_environment(p, &env, &envsize);
1155 free_pam_environment(p);
1157 #endif /* USE_PAM */
1159 if (auth_sock_name != NULL)
1160 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1163 /* read $HOME/.ssh/environment. */
1164 if (options.permit_user_env && !options.use_login) {
1165 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1166 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1167 read_environment_file(&env, &envsize, buf);
1170 /* dump the environment */
1171 fprintf(stderr, "Environment:\n");
1172 for (i = 0; env[i]; i++)
1173 fprintf(stderr, " %.200s\n", env[i]);
1179 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1180 * first in this order).
1183 do_rc_files(Session *s, const char *shell)
1191 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1193 /* ignore _PATH_SSH_USER_RC for subsystems */
1194 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1195 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1196 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1198 fprintf(stderr, "Running %s\n", cmd);
1199 f = popen(cmd, "w");
1202 fprintf(f, "%s %s\n", s->auth_proto,
1206 fprintf(stderr, "Could not run %s\n",
1208 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1210 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1211 _PATH_SSH_SYSTEM_RC);
1212 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1215 fprintf(f, "%s %s\n", s->auth_proto,
1219 fprintf(stderr, "Could not run %s\n",
1220 _PATH_SSH_SYSTEM_RC);
1221 } else if (do_xauth && options.xauth_location != NULL) {
1222 /* Add authority data to .Xauthority if appropriate. */
1225 "Running %.500s remove %.100s\n",
1226 options.xauth_location, s->auth_display);
1228 "%.500s add %.100s %.100s %.100s\n",
1229 options.xauth_location, s->auth_display,
1230 s->auth_proto, s->auth_data);
1232 snprintf(cmd, sizeof cmd, "%s -q -",
1233 options.xauth_location);
1234 f = popen(cmd, "w");
1236 fprintf(f, "remove %s\n",
1238 fprintf(f, "add %s %s %s\n",
1239 s->auth_display, s->auth_proto,
1243 fprintf(stderr, "Could not run %s\n",
1250 do_nologin(struct passwd *pw)
1255 #ifdef HAVE_LOGIN_CAP
1256 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1257 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1258 _PATH_NOLOGIN), "r");
1261 f = fopen(_PATH_NOLOGIN, "r");
1264 /* /etc/nologin exists. Print its contents and exit. */
1265 logit("User %.100s not allowed because %s exists",
1266 pw->pw_name, _PATH_NOLOGIN);
1267 while (fgets(buf, sizeof(buf), f))
1275 /* Set login name, uid, gid, and groups. */
1277 do_setusercontext(struct passwd *pw)
1280 if (getuid() == 0 || geteuid() == 0)
1281 #endif /* HAVE_CYGWIN */
1284 #ifdef HAVE_SETPCRED
1285 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1286 fatal("Failed to set process credentials");
1287 #endif /* HAVE_SETPCRED */
1288 #ifdef HAVE_LOGIN_CAP
1293 if (options.gss_authentication) {
1294 temporarily_use_uid(pw);
1295 ssh_gssapi_storecreds();
1300 if (options.use_pam) {
1304 # endif /* USE_PAM */
1305 if (setusercontext(lc, pw, pw->pw_uid,
1306 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1307 perror("unable to set user context");
1311 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1312 /* Sets login uid for accounting */
1313 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1314 error("setluid: %s", strerror(errno));
1315 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1317 if (setlogin(pw->pw_name) < 0)
1318 error("setlogin failed: %s", strerror(errno));
1319 if (setgid(pw->pw_gid) < 0) {
1323 /* Initialize the group list. */
1324 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1325 perror("initgroups");
1330 if (options.gss_authentication) {
1331 temporarily_use_uid(pw);
1332 ssh_gssapi_storecreds();
1338 * PAM credentials may take the form of supplementary groups.
1339 * These will have been wiped by the above initgroups() call.
1340 * Reestablish them here.
1342 if (options.use_pam) {
1346 # endif /* USE_PAM */
1347 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1348 irix_setusercontext(pw);
1349 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1353 #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
1354 if (set_id(pw->pw_name) != 0) {
1357 #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
1358 /* Permanently switch to the desired uid. */
1359 permanently_set_uid(pw);
1366 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1367 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1370 ssh_selinux_setup_exec_context(pw->pw_name);
1375 do_pwchange(Session *s)
1378 fprintf(stderr, "WARNING: Your password has expired.\n");
1379 if (s->ttyfd != -1) {
1381 "You must change your password now and login again!\n");
1382 #ifdef PASSWD_NEEDS_USERNAME
1383 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1386 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1391 "Password change required but no TTY available.\n");
1397 launch_login(struct passwd *pw, const char *hostname)
1399 /* Launch login(1). */
1401 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1402 #ifdef xxxLOGIN_NEEDS_TERM
1403 (s->term ? s->term : "unknown"),
1404 #endif /* LOGIN_NEEDS_TERM */
1405 #ifdef LOGIN_NO_ENDOPT
1406 "-p", "-f", pw->pw_name, (char *)NULL);
1408 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1411 /* Login couldn't be executed, die. */
1418 child_close_fds(void)
1422 if (packet_get_connection_in() == packet_get_connection_out())
1423 close(packet_get_connection_in());
1425 close(packet_get_connection_in());
1426 close(packet_get_connection_out());
1429 * Close all descriptors related to channels. They will still remain
1430 * open in the parent.
1432 /* XXX better use close-on-exec? -markus */
1433 channel_close_all();
1436 * Close any extra file descriptors. Note that there may still be
1437 * descriptors left by system functions. They will be closed later.
1442 * Close any extra open file descriptors so that we don't have them
1443 * hanging around in clients. Note that we want to do this after
1444 * initgroups, because at least on Solaris 2.3 it leaves file
1447 for (i = 3; i < 64; i++)
1452 * Performs common processing for the child, such as setting up the
1453 * environment, closing extra file descriptors, setting the user and group
1454 * ids, and executing the command or shell.
1457 do_child(Session *s, const char *command)
1459 extern char **environ;
1462 const char *shell, *shell0, *hostname = NULL;
1463 struct passwd *pw = s->pw;
1465 /* remove hostkey from the child's memory */
1466 destroy_sensitive_data();
1468 /* Force a password change */
1469 if (s->authctxt->force_pwchange) {
1470 do_setusercontext(pw);
1476 /* login(1) is only called if we execute the login shell */
1477 if (options.use_login && command != NULL)
1478 options.use_login = 0;
1481 cray_setup(pw->pw_uid, pw->pw_name, command);
1482 #endif /* _UNICOS */
1485 * Login(1) does this as well, and it needs uid 0 for the "-h"
1486 * switch, so we let login(1) to this for us.
1488 if (!options.use_login) {
1490 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1491 if (!check_quietlogin(s, command))
1493 #else /* HAVE_OSF_SIA */
1494 /* When PAM is enabled we rely on it to do the nologin check */
1495 if (!options.use_pam)
1497 do_setusercontext(pw);
1499 * PAM session modules in do_setusercontext may have
1500 * generated messages, so if this in an interactive
1501 * login then display them too.
1503 if (!check_quietlogin(s, command))
1505 #endif /* HAVE_OSF_SIA */
1509 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1510 debug3("PAM session not opened, exiting");
1517 * Get the shell from the password data. An empty shell field is
1518 * legal, and means /bin/sh.
1520 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1523 * Make sure $SHELL points to the shell from the password file,
1524 * even if shell is overridden from login.conf
1526 env = do_setup_env(s, shell);
1528 #ifdef HAVE_LOGIN_CAP
1529 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1532 /* we have to stash the hostname before we close our socket. */
1533 if (options.use_login)
1534 hostname = get_remote_name_or_ip(utmp_len,
1537 * Close the connection descriptors; note that this is the child, and
1538 * the server will still have the socket open, and it is important
1539 * that we do not shutdown it. Note that the descriptors cannot be
1540 * closed before building the environment, as we call
1541 * get_remote_ipaddr there.
1546 * Must take new environment into use so that .ssh/rc,
1547 * /etc/ssh/sshrc and xauth are run in the proper environment.
1551 #if defined(KRB5) && defined(USE_AFS)
1553 * At this point, we check to see if AFS is active and if we have
1554 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1555 * if we can (and need to) extend the ticket into an AFS token. If
1556 * we don't do this, we run into potential problems if the user's
1557 * home directory is in AFS and it's not world-readable.
1560 if (options.kerberos_get_afs_token && k_hasafs() &&
1561 (s->authctxt->krb5_ctx != NULL)) {
1564 debug("Getting AFS token");
1568 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1569 krb5_afslog(s->authctxt->krb5_ctx,
1570 s->authctxt->krb5_fwd_ccache, cell, NULL);
1572 krb5_afslog_home(s->authctxt->krb5_ctx,
1573 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1577 /* Change current directory to the user's home directory. */
1578 if (chdir(pw->pw_dir) < 0) {
1579 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1580 pw->pw_dir, strerror(errno));
1581 #ifdef HAVE_LOGIN_CAP
1582 if (login_getcapbool(lc, "requirehome", 0))
1587 if (!options.use_login)
1588 do_rc_files(s, shell);
1590 /* restore SIGPIPE for child */
1591 signal(SIGPIPE, SIG_DFL);
1593 if (options.use_login) {
1594 launch_login(pw, hostname);
1598 /* Get the last component of the shell name. */
1599 if ((shell0 = strrchr(shell, '/')) != NULL)
1605 * If we have no command, execute the shell. In this case, the shell
1606 * name to be passed in argv[0] is preceded by '-' to indicate that
1607 * this is a login shell.
1612 /* Start the shell. Set initial character to '-'. */
1615 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1616 >= sizeof(argv0) - 1) {
1622 /* Execute the shell. */
1625 execve(shell, argv, env);
1627 /* Executing the shell failed. */
1632 * Execute the command using the user's shell. This uses the -c
1633 * option to execute the command.
1635 argv[0] = (char *) shell0;
1637 argv[2] = (char *) command;
1639 execve(shell, argv, env);
1648 static int did_init = 0;
1650 debug("session_new: init");
1651 for (i = 0; i < MAX_SESSIONS; i++) {
1652 sessions[i].used = 0;
1656 for (i = 0; i < MAX_SESSIONS; i++) {
1657 Session *s = &sessions[i];
1659 memset(s, 0, sizeof(*s));
1665 s->x11_chanids = NULL;
1666 debug("session_new: session %d", i);
1677 for (i = 0; i < MAX_SESSIONS; i++) {
1678 Session *s = &sessions[i];
1679 debug("dump: used %d session %d %p channel %d pid %ld",
1689 session_open(Authctxt *authctxt, int chanid)
1691 Session *s = session_new();
1692 debug("session_open: channel %d", chanid);
1694 error("no more sessions");
1697 s->authctxt = authctxt;
1698 s->pw = authctxt->pw;
1699 if (s->pw == NULL || !authctxt->valid)
1700 fatal("no user for session %d", s->self);
1701 debug("session_open: session %d: link with channel %d", s->self, chanid);
1707 session_by_tty(char *tty)
1710 for (i = 0; i < MAX_SESSIONS; i++) {
1711 Session *s = &sessions[i];
1712 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1713 debug("session_by_tty: session %d tty %s", i, tty);
1717 debug("session_by_tty: unknown tty %.100s", tty);
1723 session_by_channel(int id)
1726 for (i = 0; i < MAX_SESSIONS; i++) {
1727 Session *s = &sessions[i];
1728 if (s->used && s->chanid == id) {
1729 debug("session_by_channel: session %d channel %d", i, id);
1733 debug("session_by_channel: unknown channel %d", id);
1739 session_by_x11_channel(int id)
1743 for (i = 0; i < MAX_SESSIONS; i++) {
1744 Session *s = &sessions[i];
1746 if (s->x11_chanids == NULL || !s->used)
1748 for (j = 0; s->x11_chanids[j] != -1; j++) {
1749 if (s->x11_chanids[j] == id) {
1750 debug("session_by_x11_channel: session %d "
1751 "channel %d", s->self, id);
1756 debug("session_by_x11_channel: unknown channel %d", id);
1762 session_by_pid(pid_t pid)
1765 debug("session_by_pid: pid %ld", (long)pid);
1766 for (i = 0; i < MAX_SESSIONS; i++) {
1767 Session *s = &sessions[i];
1768 if (s->used && s->pid == pid)
1771 error("session_by_pid: unknown pid %ld", (long)pid);
1777 session_window_change_req(Session *s)
1779 s->col = packet_get_int();
1780 s->row = packet_get_int();
1781 s->xpixel = packet_get_int();
1782 s->ypixel = packet_get_int();
1784 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1789 session_pty_req(Session *s)
1795 debug("Allocating a pty not permitted for this authentication.");
1798 if (s->ttyfd != -1) {
1799 packet_disconnect("Protocol error: you already have a pty.");
1803 s->term = packet_get_string(&len);
1806 s->col = packet_get_int();
1807 s->row = packet_get_int();
1809 s->row = packet_get_int();
1810 s->col = packet_get_int();
1812 s->xpixel = packet_get_int();
1813 s->ypixel = packet_get_int();
1815 if (strcmp(s->term, "") == 0) {
1820 /* Allocate a pty and open it. */
1821 debug("Allocating pty.");
1822 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1828 error("session_pty_req: session %d alloc failed", s->self);
1831 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1833 /* for SSH1 the tty modes length is not given */
1835 n_bytes = packet_remaining();
1836 tty_parse_modes(s->ttyfd, &n_bytes);
1839 pty_setowner(s->pw, s->tty);
1841 /* Set window size from the packet. */
1842 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1845 session_proctitle(s);
1850 session_subsystem_req(Session *s)
1855 char *prog, *cmd, *subsys = packet_get_string(&len);
1859 logit("subsystem request for %.100s", subsys);
1861 for (i = 0; i < options.num_subsystems; i++) {
1862 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1863 prog = options.subsystem_command[i];
1864 cmd = options.subsystem_args[i];
1865 if (stat(prog, &st) < 0) {
1866 error("subsystem: cannot stat %s: %s", prog,
1870 debug("subsystem: exec() %s", cmd);
1871 s->is_subsystem = 1;
1879 logit("subsystem request for %.100s failed, subsystem not found",
1887 session_x11_req(Session *s)
1891 if (s->auth_proto != NULL || s->auth_data != NULL) {
1892 error("session_x11_req: session %d: "
1893 "x11 forwarding already active", s->self);
1896 s->single_connection = packet_get_char();
1897 s->auth_proto = packet_get_string(NULL);
1898 s->auth_data = packet_get_string(NULL);
1899 s->screen = packet_get_int();
1902 success = session_setup_x11fwd(s);
1904 xfree(s->auth_proto);
1905 xfree(s->auth_data);
1906 s->auth_proto = NULL;
1907 s->auth_data = NULL;
1913 session_shell_req(Session *s)
1921 session_exec_req(Session *s)
1924 char *command = packet_get_string(&len);
1926 do_exec(s, command);
1932 session_break_req(Session *s)
1935 packet_get_int(); /* ignored */
1938 if (s->ttyfd == -1 ||
1939 tcsendbreak(s->ttyfd, 0) < 0)
1945 session_env_req(Session *s)
1948 u_int name_len, val_len, i;
1950 name = packet_get_string(&name_len);
1951 val = packet_get_string(&val_len);
1954 /* Don't set too many environment variables */
1955 if (s->num_env > 128) {
1956 debug2("Ignoring env request %s: too many env vars", name);
1960 for (i = 0; i < options.num_accept_env; i++) {
1961 if (match_pattern(name, options.accept_env[i])) {
1962 debug2("Setting env %d: %s=%s", s->num_env, name, val);
1963 s->env = xrealloc(s->env, s->num_env + 1,
1965 s->env[s->num_env].name = name;
1966 s->env[s->num_env].val = val;
1971 debug2("Ignoring env request %s: disallowed name", name);
1980 session_auth_agent_req(Session *s)
1982 static int called = 0;
1984 if (no_agent_forwarding_flag) {
1985 debug("session_auth_agent_req: no_agent_forwarding_flag");
1992 return auth_input_request_forwarding(s->pw);
1997 session_input_channel_req(Channel *c, const char *rtype)
2002 if ((s = session_by_channel(c->self)) == NULL) {
2003 logit("session_input_channel_req: no session %d req %.100s",
2007 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2010 * a session is in LARVAL state until a shell, a command
2011 * or a subsystem is executed
2013 if (c->type == SSH_CHANNEL_LARVAL) {
2014 if (strcmp(rtype, "shell") == 0) {
2015 success = session_shell_req(s);
2016 } else if (strcmp(rtype, "exec") == 0) {
2017 success = session_exec_req(s);
2018 } else if (strcmp(rtype, "pty-req") == 0) {
2019 success = session_pty_req(s);
2020 } else if (strcmp(rtype, "x11-req") == 0) {
2021 success = session_x11_req(s);
2022 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2023 success = session_auth_agent_req(s);
2024 } else if (strcmp(rtype, "subsystem") == 0) {
2025 success = session_subsystem_req(s);
2026 } else if (strcmp(rtype, "env") == 0) {
2027 success = session_env_req(s);
2030 if (strcmp(rtype, "window-change") == 0) {
2031 success = session_window_change_req(s);
2032 } else if (strcmp(rtype, "break") == 0) {
2033 success = session_break_req(s);
2040 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2043 fatal("session_set_fds: called for proto != 2.0");
2045 * now that have a child and a pipe to the child,
2046 * we can activate our channel and register the fd's
2048 if (s->chanid == -1)
2049 fatal("no channel for session %d", s->self);
2050 channel_set_fds(s->chanid,
2052 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2054 CHAN_SES_WINDOW_DEFAULT);
2058 * Function to perform pty cleanup. Also called if we get aborted abnormally
2059 * (e.g., due to a dropped connection).
2062 session_pty_cleanup2(Session *s)
2065 error("session_pty_cleanup: no session");
2071 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2073 /* Record that the user has logged out. */
2075 record_logout(s->pid, s->tty, s->pw->pw_name);
2077 /* Release the pseudo-tty. */
2079 pty_release(s->tty);
2082 * Close the server side of the socket pairs. We must do this after
2083 * the pty cleanup, so that another process doesn't get this pty
2084 * while we're still cleaning up.
2086 if (close(s->ptymaster) < 0)
2087 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2089 /* unlink pty from session */
2094 session_pty_cleanup(Session *s)
2096 PRIVSEP(session_pty_cleanup2(s));
2102 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2117 return "SIG@openssh.com";
2121 session_close_x11(int id)
2125 if ((c = channel_by_id(id)) == NULL) {
2126 debug("session_close_x11: x11 channel %d missing", id);
2128 /* Detach X11 listener */
2129 debug("session_close_x11: detach x11 channel %d", id);
2130 channel_cancel_cleanup(id);
2131 if (c->ostate != CHAN_OUTPUT_CLOSED)
2137 session_close_single_x11(int id, void *arg)
2142 debug3("session_close_single_x11: channel %d", id);
2143 channel_cancel_cleanup(id);
2144 if ((s = session_by_x11_channel(id)) == NULL)
2145 fatal("session_close_single_x11: no x11 channel %d", id);
2146 for (i = 0; s->x11_chanids[i] != -1; i++) {
2147 debug("session_close_single_x11: session %d: "
2148 "closing channel %d", s->self, s->x11_chanids[i]);
2150 * The channel "id" is already closing, but make sure we
2151 * close all of its siblings.
2153 if (s->x11_chanids[i] != id)
2154 session_close_x11(s->x11_chanids[i]);
2156 xfree(s->x11_chanids);
2157 s->x11_chanids = NULL;
2162 if (s->auth_proto) {
2163 xfree(s->auth_proto);
2164 s->auth_proto = NULL;
2167 xfree(s->auth_data);
2168 s->auth_data = NULL;
2170 if (s->auth_display) {
2171 xfree(s->auth_display);
2172 s->auth_display = NULL;
2177 session_exit_message(Session *s, int status)
2181 if ((c = channel_lookup(s->chanid)) == NULL)
2182 fatal("session_exit_message: session %d: no channel %d",
2183 s->self, s->chanid);
2184 debug("session_exit_message: session %d channel %d pid %ld",
2185 s->self, s->chanid, (long)s->pid);
2187 if (WIFEXITED(status)) {
2188 channel_request_start(s->chanid, "exit-status", 0);
2189 packet_put_int(WEXITSTATUS(status));
2191 } else if (WIFSIGNALED(status)) {
2192 channel_request_start(s->chanid, "exit-signal", 0);
2193 packet_put_cstring(sig2name(WTERMSIG(status)));
2195 packet_put_char(WCOREDUMP(status));
2196 #else /* WCOREDUMP */
2198 #endif /* WCOREDUMP */
2199 packet_put_cstring("");
2200 packet_put_cstring("");
2203 /* Some weird exit cause. Just exit. */
2204 packet_disconnect("wait returned status %04x.", status);
2207 /* disconnect channel */
2208 debug("session_exit_message: release channel %d", s->chanid);
2211 * Adjust cleanup callback attachment to send close messages when
2212 * the channel gets EOF. The session will be then be closed
2213 * by session_close_by_channel when the childs close their fds.
2215 channel_register_cleanup(c->self, session_close_by_channel, 1);
2218 * emulate a write failure with 'chan_write_failed', nobody will be
2219 * interested in data we write.
2220 * Note that we must not call 'chan_read_failed', since there could
2221 * be some more data waiting in the pipe.
2223 if (c->ostate != CHAN_OUTPUT_CLOSED)
2224 chan_write_failed(c);
2228 session_close(Session *s)
2232 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2234 session_pty_cleanup(s);
2240 xfree(s->x11_chanids);
2241 if (s->auth_display)
2242 xfree(s->auth_display);
2244 xfree(s->auth_data);
2246 xfree(s->auth_proto);
2248 for (i = 0; i < s->num_env; i++) {
2249 xfree(s->env[i].name);
2250 xfree(s->env[i].val);
2254 session_proctitle(s);
2258 session_close_by_pid(pid_t pid, int status)
2260 Session *s = session_by_pid(pid);
2262 debug("session_close_by_pid: no session for pid %ld",
2266 if (s->chanid != -1)
2267 session_exit_message(s, status);
2269 session_pty_cleanup(s);
2274 * this is called when a channel dies before
2275 * the session 'child' itself dies
2278 session_close_by_channel(int id, void *arg)
2280 Session *s = session_by_channel(id);
2284 debug("session_close_by_channel: no session for id %d", id);
2287 debug("session_close_by_channel: channel %d child %ld",
2290 debug("session_close_by_channel: channel %d: has child", id);
2292 * delay detach of session, but release pty, since
2293 * the fd's to the child are already closed
2296 session_pty_cleanup(s);
2299 /* detach by removing callback */
2300 channel_cancel_cleanup(s->chanid);
2302 /* Close any X11 listeners associated with this session */
2303 if (s->x11_chanids != NULL) {
2304 for (i = 0; s->x11_chanids[i] != -1; i++) {
2305 session_close_x11(s->x11_chanids[i]);
2306 s->x11_chanids[i] = -1;
2315 session_destroy_all(void (*closefunc)(Session *))
2318 for (i = 0; i < MAX_SESSIONS; i++) {
2319 Session *s = &sessions[i];
2321 if (closefunc != NULL)
2330 session_tty_list(void)
2332 static char buf[1024];
2337 for (i = 0; i < MAX_SESSIONS; i++) {
2338 Session *s = &sessions[i];
2339 if (s->used && s->ttyfd != -1) {
2341 if (strncmp(s->tty, "/dev/", 5) != 0) {
2342 cp = strrchr(s->tty, '/');
2343 cp = (cp == NULL) ? s->tty : cp + 1;
2348 strlcat(buf, ",", sizeof buf);
2349 strlcat(buf, cp, sizeof buf);
2353 strlcpy(buf, "notty", sizeof buf);
2358 session_proctitle(Session *s)
2361 error("no user for session %d", s->self);
2363 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2367 session_setup_x11fwd(Session *s)
2370 char display[512], auth_display[512];
2371 char hostname[MAXHOSTNAMELEN];
2374 if (no_x11_forwarding_flag) {
2375 packet_send_debug("X11 forwarding disabled in user configuration file.");
2378 if (!options.x11_forwarding) {
2379 debug("X11 forwarding disabled in server configuration file.");
2382 if (!options.xauth_location ||
2383 (stat(options.xauth_location, &st) == -1)) {
2384 packet_send_debug("No xauth program; cannot forward with spoofing.");
2387 if (options.use_login) {
2388 packet_send_debug("X11 forwarding disabled; "
2389 "not compatible with UseLogin=yes.");
2392 if (s->display != NULL) {
2393 debug("X11 display already set.");
2396 if (x11_create_display_inet(options.x11_display_offset,
2397 options.x11_use_localhost, s->single_connection,
2398 &s->display_number, &s->x11_chanids) == -1) {
2399 debug("x11_create_display_inet failed.");
2402 for (i = 0; s->x11_chanids[i] != -1; i++) {
2403 channel_register_cleanup(s->x11_chanids[i],
2404 session_close_single_x11, 0);
2407 /* Set up a suitable value for the DISPLAY variable. */
2408 if (gethostname(hostname, sizeof(hostname)) < 0)
2409 fatal("gethostname: %.100s", strerror(errno));
2411 * auth_display must be used as the displayname when the
2412 * authorization entry is added with xauth(1). This will be
2413 * different than the DISPLAY string for localhost displays.
2415 if (options.x11_use_localhost) {
2416 snprintf(display, sizeof display, "localhost:%u.%u",
2417 s->display_number, s->screen);
2418 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2419 s->display_number, s->screen);
2420 s->display = xstrdup(display);
2421 s->auth_display = xstrdup(auth_display);
2423 #ifdef IPADDR_IN_DISPLAY
2425 struct in_addr my_addr;
2427 he = gethostbyname(hostname);
2429 error("Can't get IP address for X11 DISPLAY.");
2430 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2433 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2434 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2435 s->display_number, s->screen);
2437 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2438 s->display_number, s->screen);
2440 s->display = xstrdup(display);
2441 s->auth_display = xstrdup(display);
2448 do_authenticated2(Authctxt *authctxt)
2450 server_loop2(authctxt);
2454 do_cleanup(Authctxt *authctxt)
2456 static int called = 0;
2458 debug("do_cleanup");
2460 /* no cleanup if we're in the child for login shell */
2464 /* avoid double cleanup */
2469 if (authctxt == NULL)
2472 if (options.kerberos_ticket_cleanup &&
2474 krb5_cleanup_proc(authctxt);
2478 if (compat20 && options.gss_cleanup_creds)
2479 ssh_gssapi_cleanup_creds();
2483 if (options.use_pam) {
2485 sshpam_thread_cleanup();
2489 /* remove agent socket */
2490 auth_sock_cleanup_proc(authctxt->pw);
2493 * Cleanup ptys/utmp only if privsep is disabled,
2494 * or if running in monitor.
2496 if (!use_privsep || mm_is_monitor())
2497 session_destroy_all(session_pty_cleanup2);