1 /* $OpenBSD: session.c,v 1.203 2006/04/20 21:53:44 djm 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>
63 #include "auth-options.h"
64 #include "pathnames.h"
68 #include "serverloop.h"
72 #include "monitor_wrap.h"
74 #if defined(KRB5) && defined(USE_AFS)
84 Session *session_new(void);
85 void session_set_fds(Session *, int, int, int);
86 void session_pty_cleanup(Session *);
87 void session_proctitle(Session *);
88 int session_setup_x11fwd(Session *);
89 void do_exec_pty(Session *, const char *);
90 void do_exec_no_pty(Session *, const char *);
91 void do_exec(Session *, const char *);
92 void do_login(Session *, const char *);
93 #ifdef LOGIN_NEEDS_UTMPX
94 static void do_pre_login(Session *s);
96 void do_child(Session *, const char *);
98 int check_quietlogin(Session *, const char *);
100 static void do_authenticated1(Authctxt *);
101 static void do_authenticated2(Authctxt *);
103 static int session_pty_req(Session *);
106 extern ServerOptions options;
107 extern char *__progname;
108 extern int log_stderr;
109 extern int debug_flag;
110 extern u_int utmp_len;
111 extern int startup_pipe;
112 extern void destroy_sensitive_data(void);
113 extern Buffer loginmsg;
115 /* original command from peer. */
116 const char *original_command = NULL;
119 #define MAX_SESSIONS 10
120 Session sessions[MAX_SESSIONS];
122 #ifdef HAVE_LOGIN_CAP
126 static int is_child = 0;
128 /* Name and directory of socket for authentication agent forwarding. */
129 static char *auth_sock_name = NULL;
130 static char *auth_sock_dir = NULL;
132 /* removes the agent forwarding socket */
135 auth_sock_cleanup_proc(struct passwd *pw)
137 if (auth_sock_name != NULL) {
138 temporarily_use_uid(pw);
139 unlink(auth_sock_name);
140 rmdir(auth_sock_dir);
141 auth_sock_name = NULL;
147 auth_input_request_forwarding(struct passwd * pw)
151 struct sockaddr_un sunaddr;
153 if (auth_sock_name != NULL) {
154 error("authentication forwarding requested twice.");
158 /* Temporarily drop privileged uid for mkdir/bind. */
159 temporarily_use_uid(pw);
161 /* Allocate a buffer for the socket name, and format the name. */
162 auth_sock_name = xmalloc(MAXPATHLEN);
163 auth_sock_dir = xmalloc(MAXPATHLEN);
164 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
166 /* Create private directory for socket */
167 if (mkdtemp(auth_sock_dir) == NULL) {
168 packet_send_debug("Agent forwarding disabled: "
169 "mkdtemp() failed: %.100s", strerror(errno));
171 xfree(auth_sock_name);
172 xfree(auth_sock_dir);
173 auth_sock_name = NULL;
174 auth_sock_dir = NULL;
177 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
178 auth_sock_dir, (long) getpid());
180 /* Create the socket. */
181 sock = socket(AF_UNIX, SOCK_STREAM, 0);
183 packet_disconnect("socket: %.100s", strerror(errno));
185 /* Bind it to the name. */
186 memset(&sunaddr, 0, sizeof(sunaddr));
187 sunaddr.sun_family = AF_UNIX;
188 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
190 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0)
191 packet_disconnect("bind: %.100s", strerror(errno));
193 /* Restore the privileged uid. */
196 /* Start listening on the socket. */
197 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
198 packet_disconnect("listen: %.100s", strerror(errno));
200 /* Allocate a channel for the authentication agent socket. */
201 nc = channel_new("auth socket",
202 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
203 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
204 0, "auth socket", 1);
205 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
210 display_loginmsg(void)
212 if (buffer_len(&loginmsg) > 0) {
213 buffer_append(&loginmsg, "\0", 1);
214 printf("%s", (char *)buffer_ptr(&loginmsg));
215 buffer_clear(&loginmsg);
220 do_authenticated(Authctxt *authctxt)
222 setproctitle("%s", authctxt->pw->pw_name);
224 /* setup the channel layer */
225 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
226 channel_permit_all_opens();
229 do_authenticated2(authctxt);
231 do_authenticated1(authctxt);
233 do_cleanup(authctxt);
237 * Prepares for an interactive session. This is called after the user has
238 * been successfully authenticated. During this message exchange, pseudo
239 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
240 * are requested, etc.
243 do_authenticated1(Authctxt *authctxt)
247 int success, type, screen_flag;
248 int enable_compression_after_reply = 0;
249 u_int proto_len, data_len, dlen, compression_level = 0;
253 error("no more sessions");
256 s->authctxt = authctxt;
257 s->pw = authctxt->pw;
260 * We stay in this loop until the client requests to execute a shell
266 /* Get a packet from the client. */
267 type = packet_read();
269 /* Process the packet. */
271 case SSH_CMSG_REQUEST_COMPRESSION:
272 compression_level = packet_get_int();
274 if (compression_level < 1 || compression_level > 9) {
275 packet_send_debug("Received invalid compression level %d.",
279 if (options.compression == COMP_NONE) {
280 debug2("compression disabled");
283 /* Enable compression after we have responded with SUCCESS. */
284 enable_compression_after_reply = 1;
288 case SSH_CMSG_REQUEST_PTY:
289 success = session_pty_req(s);
292 case SSH_CMSG_X11_REQUEST_FORWARDING:
293 s->auth_proto = packet_get_string(&proto_len);
294 s->auth_data = packet_get_string(&data_len);
296 screen_flag = packet_get_protocol_flags() &
297 SSH_PROTOFLAG_SCREEN_NUMBER;
298 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
300 if (packet_remaining() == 4) {
302 debug2("Buggy client: "
303 "X11 screen flag missing");
304 s->screen = packet_get_int();
309 success = session_setup_x11fwd(s);
311 xfree(s->auth_proto);
313 s->auth_proto = NULL;
318 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
319 if (no_agent_forwarding_flag || compat13) {
320 debug("Authentication agent forwarding not permitted for this authentication.");
323 debug("Received authentication agent forwarding request.");
324 success = auth_input_request_forwarding(s->pw);
327 case SSH_CMSG_PORT_FORWARD_REQUEST:
328 if (no_port_forwarding_flag) {
329 debug("Port forwarding not permitted for this authentication.");
332 if (!options.allow_tcp_forwarding) {
333 debug("Port forwarding not permitted.");
336 debug("Received TCP/IP port forwarding request.");
337 channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
341 case SSH_CMSG_MAX_PACKET_SIZE:
342 if (packet_set_maxsize(packet_get_int()) > 0)
346 case SSH_CMSG_EXEC_SHELL:
347 case SSH_CMSG_EXEC_CMD:
348 if (type == SSH_CMSG_EXEC_CMD) {
349 command = packet_get_string(&dlen);
350 debug("Exec command '%.500s'", command);
362 * Any unknown messages in this phase are ignored,
363 * and a failure message is returned.
365 logit("Unknown packet type received after authentication: %d", type);
367 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
371 /* Enable compression now that we have replied if appropriate. */
372 if (enable_compression_after_reply) {
373 enable_compression_after_reply = 0;
374 packet_start_compression(compression_level);
380 * This is called to fork and execute a command when we have no tty. This
381 * will call do_child from the child, and server_loop from the parent after
382 * setting up file descriptors and such.
385 do_exec_no_pty(Session *s, const char *command)
390 int pin[2], pout[2], perr[2];
391 /* Allocate pipes for communicating with the program. */
392 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
393 packet_disconnect("Could not create pipes: %.100s",
395 #else /* USE_PIPES */
396 int inout[2], err[2];
397 /* Uses socket pairs to communicate with the program. */
398 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
399 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
400 packet_disconnect("Could not create socket pairs: %.100s",
402 #endif /* USE_PIPES */
404 fatal("do_exec_no_pty: no session");
406 session_proctitle(s);
409 if (options.use_pam && !use_privsep)
413 /* Fork the child. */
414 if ((pid = fork()) == 0) {
417 /* Child. Reinitialize the log since the pid has changed. */
418 log_init(__progname, options.log_level, options.log_facility, log_stderr);
421 * Create a new session and process group since the 4.4BSD
422 * setlogin() affects the entire process group.
425 error("setsid failed: %.100s", strerror(errno));
429 * Redirect stdin. We close the parent side of the socket
430 * pair, and make the child side the standard input.
433 if (dup2(pin[0], 0) < 0)
434 perror("dup2 stdin");
437 /* Redirect stdout. */
439 if (dup2(pout[1], 1) < 0)
440 perror("dup2 stdout");
443 /* Redirect stderr. */
445 if (dup2(perr[1], 2) < 0)
446 perror("dup2 stderr");
448 #else /* USE_PIPES */
450 * Redirect stdin, stdout, and stderr. Stdin and stdout will
451 * use the same socket, as some programs (particularly rdist)
452 * seem to depend on it.
456 if (dup2(inout[0], 0) < 0) /* stdin */
457 perror("dup2 stdin");
458 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
459 perror("dup2 stdout");
460 if (dup2(err[0], 2) < 0) /* stderr */
461 perror("dup2 stderr");
462 #endif /* USE_PIPES */
465 cray_init_job(s->pw); /* set up cray jid and tmpdir */
468 /* Do processing for the child (exec command etc). */
469 do_child(s, command);
473 signal(WJSIGNAL, cray_job_termination_handler);
477 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
480 packet_disconnect("fork failed: %.100s", strerror(errno));
482 /* Set interactive/non-interactive mode. */
483 packet_set_interactive(s->display != NULL);
485 /* We are the parent. Close the child sides of the pipes. */
491 if (s->is_subsystem) {
495 session_set_fds(s, pin[1], pout[0], perr[0]);
497 /* Enter the interactive session. */
498 server_loop(pid, pin[1], pout[0], perr[0]);
499 /* server_loop has closed pin[1], pout[0], and perr[0]. */
501 #else /* USE_PIPES */
502 /* We are the parent. Close the child sides of the socket pairs. */
507 * Clear loginmsg, since it's the child's responsibility to display
508 * it to the user, otherwise multiple sessions may accumulate
509 * multiple copies of the login messages.
511 buffer_clear(&loginmsg);
514 * Enter the interactive session. Note: server_loop must be able to
515 * handle the case that fdin and fdout are the same.
518 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
520 server_loop(pid, inout[1], inout[1], err[1]);
521 /* server_loop has closed inout[1] and err[1]. */
523 #endif /* USE_PIPES */
527 * This is called to fork and execute a command when we have a tty. This
528 * will call do_child from the child, and server_loop from the parent after
529 * setting up file descriptors, controlling tty, updating wtmp, utmp,
530 * lastlog, and other such operations.
533 do_exec_pty(Session *s, const char *command)
535 int fdout, ptyfd, ttyfd, ptymaster;
539 fatal("do_exec_pty: no session");
544 if (options.use_pam) {
545 do_pam_set_tty(s->tty);
551 /* Fork the child. */
552 if ((pid = fork()) == 0) {
555 /* Child. Reinitialize the log because the pid has changed. */
556 log_init(__progname, options.log_level, options.log_facility, log_stderr);
557 /* Close the master side of the pseudo tty. */
560 /* Make the pseudo tty our controlling tty. */
561 pty_make_controlling_tty(&ttyfd, s->tty);
563 /* Redirect stdin/stdout/stderr from the pseudo tty. */
564 if (dup2(ttyfd, 0) < 0)
565 error("dup2 stdin: %s", strerror(errno));
566 if (dup2(ttyfd, 1) < 0)
567 error("dup2 stdout: %s", strerror(errno));
568 if (dup2(ttyfd, 2) < 0)
569 error("dup2 stderr: %s", strerror(errno));
571 /* Close the extra descriptor for the pseudo tty. */
574 /* record login, etc. similar to login(1) */
576 if (!(options.use_login && command == NULL)) {
578 cray_init_job(s->pw); /* set up cray jid and tmpdir */
580 do_login(s, command);
582 # ifdef LOGIN_NEEDS_UTMPX
588 /* Do common processing for the child, such as execing the command. */
589 do_child(s, command);
593 signal(WJSIGNAL, cray_job_termination_handler);
597 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
600 packet_disconnect("fork failed: %.100s", strerror(errno));
603 /* Parent. Close the slave side of the pseudo tty. */
607 * Create another descriptor of the pty master side for use as the
608 * standard input. We could use the original descriptor, but this
609 * simplifies code in server_loop. The descriptor is bidirectional.
613 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
615 /* we keep a reference to the pty master */
616 ptymaster = dup(ptyfd);
618 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
619 s->ptymaster = ptymaster;
621 /* Enter interactive session. */
622 packet_set_interactive(1);
624 session_set_fds(s, ptyfd, fdout, -1);
626 server_loop(pid, ptyfd, fdout, -1);
627 /* server_loop _has_ closed ptyfd and fdout. */
631 #ifdef LOGIN_NEEDS_UTMPX
633 do_pre_login(Session *s)
636 struct sockaddr_storage from;
637 pid_t pid = getpid();
640 * Get IP address of client. If the connection is not a socket, let
641 * the address be 0.0.0.0.
643 memset(&from, 0, sizeof(from));
644 fromlen = sizeof(from);
645 if (packet_connection_is_on_socket()) {
646 if (getpeername(packet_get_connection_in(),
647 (struct sockaddr *)&from, &fromlen) < 0) {
648 debug("getpeername: %.100s", strerror(errno));
653 record_utmp_only(pid, s->tty, s->pw->pw_name,
654 get_remote_name_or_ip(utmp_len, options.use_dns),
655 (struct sockaddr *)&from, fromlen);
660 * This is called to fork and execute a command. If another command is
661 * to be forced, execute that instead.
664 do_exec(Session *s, const char *command)
666 if (forced_command) {
667 original_command = command;
668 command = forced_command;
669 debug("Forced command '%.900s'", command);
672 #ifdef SSH_AUDIT_EVENTS
674 PRIVSEP(audit_run_command(command));
675 else if (s->ttyfd == -1) {
676 char *shell = s->pw->pw_shell;
678 if (shell[0] == '\0') /* empty shell means /bin/sh */
680 PRIVSEP(audit_run_command(shell));
685 do_exec_pty(s, command);
687 do_exec_no_pty(s, command);
689 original_command = NULL;
692 * Clear loginmsg: it's the child's responsibility to display
693 * it to the user, otherwise multiple sessions may accumulate
694 * multiple copies of the login messages.
696 buffer_clear(&loginmsg);
699 /* administrative, login(1)-like work */
701 do_login(Session *s, const char *command)
704 struct sockaddr_storage from;
705 struct passwd * pw = s->pw;
706 pid_t pid = getpid();
709 * Get IP address of client. If the connection is not a socket, let
710 * the address be 0.0.0.0.
712 memset(&from, 0, sizeof(from));
713 fromlen = sizeof(from);
714 if (packet_connection_is_on_socket()) {
715 if (getpeername(packet_get_connection_in(),
716 (struct sockaddr *) & from, &fromlen) < 0) {
717 debug("getpeername: %.100s", strerror(errno));
722 /* Record that there was a login on that tty from the remote host. */
724 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
725 get_remote_name_or_ip(utmp_len,
727 (struct sockaddr *)&from, fromlen);
731 * If password change is needed, do it now.
732 * This needs to occur before the ~/.hushlogin check.
734 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
737 s->authctxt->force_pwchange = 0;
738 /* XXX - signal [net] parent to enable forwardings */
742 if (check_quietlogin(s, command))
751 * Display the message of the day.
759 if (options.print_motd) {
760 #ifdef HAVE_LOGIN_CAP
761 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
764 f = fopen("/etc/motd", "r");
767 while (fgets(buf, sizeof(buf), f))
776 * Check for quiet login, either .hushlogin or command given.
779 check_quietlogin(Session *s, const char *command)
782 struct passwd *pw = s->pw;
785 /* Return 1 if .hushlogin exists or a command given. */
788 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
789 #ifdef HAVE_LOGIN_CAP
790 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
793 if (stat(buf, &st) >= 0)
800 * Sets the value of the given variable in the environment. If the variable
801 * already exists, its value is overriden.
804 child_set_env(char ***envp, u_int *envsizep, const char *name,
812 * If we're passed an uninitialized list, allocate a single null
813 * entry before continuing.
815 if (*envp == NULL && *envsizep == 0) {
816 *envp = xmalloc(sizeof(char *));
822 * Find the slot where the value should be stored. If the variable
823 * already exists, we reuse the slot; otherwise we append a new slot
824 * at the end of the array, expanding if necessary.
827 namelen = strlen(name);
828 for (i = 0; env[i]; i++)
829 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
832 /* Reuse the slot. */
835 /* New variable. Expand if necessary. */
837 if (i >= envsize - 1) {
839 fatal("child_set_env: too many env vars");
841 env = (*envp) = xrealloc(env, envsize, sizeof(char *));
844 /* Need to set the NULL pointer at end of array beyond the new slot. */
848 /* Allocate space and format the variable in the appropriate slot. */
849 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
850 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
854 * Reads environment variables from the given file and adds/overrides them
855 * into the environment. If the file does not exist, this does nothing.
856 * Otherwise, it must consist of empty lines, comments (line starts with '#')
857 * and assignments of the form name=value. No other forms are allowed.
860 read_environment_file(char ***env, u_int *envsize,
861 const char *filename)
868 f = fopen(filename, "r");
872 while (fgets(buf, sizeof(buf), f)) {
874 fatal("Too many lines in environment file %s", filename);
875 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
877 if (!*cp || *cp == '#' || *cp == '\n')
879 if (strchr(cp, '\n'))
880 *strchr(cp, '\n') = '\0';
881 value = strchr(cp, '=');
883 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
888 * Replace the equals sign by nul, and advance value to
893 child_set_env(env, envsize, cp, value);
898 #ifdef HAVE_ETC_DEFAULT_LOGIN
900 * Return named variable from specified environment, or NULL if not present.
903 child_get_env(char **env, const char *name)
909 for (i=0; env[i] != NULL; i++)
910 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
911 return(env[i] + len + 1);
916 * Read /etc/default/login.
917 * We pick up the PATH (or SUPATH for root) and UMASK.
920 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
922 char **tmpenv = NULL, *var;
923 u_int i, tmpenvsize = 0;
927 * We don't want to copy the whole file to the child's environment,
928 * so we use a temporary environment and copy the variables we're
931 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
937 var = child_get_env(tmpenv, "SUPATH");
939 var = child_get_env(tmpenv, "PATH");
941 child_set_env(env, envsize, "PATH", var);
943 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
944 if (sscanf(var, "%5lo", &mask) == 1)
947 for (i = 0; tmpenv[i] != NULL; i++)
951 #endif /* HAVE_ETC_DEFAULT_LOGIN */
954 copy_environment(char **source, char ***env, u_int *envsize)
956 char *var_name, *var_val;
962 for(i = 0; source[i] != NULL; i++) {
963 var_name = xstrdup(source[i]);
964 if ((var_val = strstr(var_name, "=")) == NULL) {
970 debug3("Copy environment: %s=%s", var_name, var_val);
971 child_set_env(env, envsize, var_name, var_val);
978 do_setup_env(Session *s, const char *shell)
982 char **env, *laddr, *path = NULL;
983 struct passwd *pw = s->pw;
985 /* Initialize the environment. */
987 env = xcalloc(envsize, sizeof(char *));
992 * The Windows environment contains some setting which are
993 * important for a running system. They must not be dropped.
998 p = fetch_windows_environment();
999 copy_environment(p, &env, &envsize);
1000 free_windows_environment(p);
1005 /* Allow any GSSAPI methods that we've used to alter
1006 * the childs environment as they see fit
1008 ssh_gssapi_do_child(&env, &envsize);
1011 if (!options.use_login) {
1012 /* Set basic environment. */
1013 for (i = 0; i < s->num_env; i++)
1014 child_set_env(&env, &envsize, s->env[i].name,
1017 child_set_env(&env, &envsize, "USER", pw->pw_name);
1018 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1020 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1022 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1023 #ifdef HAVE_LOGIN_CAP
1024 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1025 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1027 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1028 #else /* HAVE_LOGIN_CAP */
1029 # ifndef HAVE_CYGWIN
1031 * There's no standard path on Windows. The path contains
1032 * important components pointing to the system directories,
1033 * needed for loading shared libraries. So the path better
1034 * remains intact here.
1036 # ifdef HAVE_ETC_DEFAULT_LOGIN
1037 read_etc_default_login(&env, &envsize, pw->pw_uid);
1038 path = child_get_env(env, "PATH");
1039 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1040 if (path == NULL || *path == '\0') {
1041 child_set_env(&env, &envsize, "PATH",
1042 s->pw->pw_uid == 0 ?
1043 SUPERUSER_PATH : _PATH_STDPATH);
1045 # endif /* HAVE_CYGWIN */
1046 #endif /* HAVE_LOGIN_CAP */
1048 snprintf(buf, sizeof buf, "%.200s/%.50s",
1049 _PATH_MAILDIR, pw->pw_name);
1050 child_set_env(&env, &envsize, "MAIL", buf);
1052 /* Normal systems set SHELL by default. */
1053 child_set_env(&env, &envsize, "SHELL", shell);
1056 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1058 /* Set custom environment options from RSA authentication. */
1059 if (!options.use_login) {
1060 while (custom_environment) {
1061 struct envstring *ce = custom_environment;
1064 for (i = 0; str[i] != '=' && str[i]; i++)
1066 if (str[i] == '=') {
1068 child_set_env(&env, &envsize, str, str + i + 1);
1070 custom_environment = ce->next;
1076 /* SSH_CLIENT deprecated */
1077 snprintf(buf, sizeof buf, "%.50s %d %d",
1078 get_remote_ipaddr(), get_remote_port(), get_local_port());
1079 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1081 laddr = get_local_ipaddr(packet_get_connection_in());
1082 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1083 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1085 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1088 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1090 child_set_env(&env, &envsize, "TERM", s->term);
1092 child_set_env(&env, &envsize, "DISPLAY", s->display);
1093 if (original_command)
1094 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1098 if (cray_tmpdir[0] != '\0')
1099 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1100 #endif /* _UNICOS */
1103 * Since we clear KRB5CCNAME at startup, if it's set now then it
1104 * must have been set by a native authentication method (eg AIX or
1105 * SIA), so copy it to the child.
1110 if ((cp = getenv("KRB5CCNAME")) != NULL)
1111 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1118 if ((cp = getenv("AUTHSTATE")) != NULL)
1119 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1120 read_environment_file(&env, &envsize, "/etc/environment");
1124 if (s->authctxt->krb5_ccname)
1125 child_set_env(&env, &envsize, "KRB5CCNAME",
1126 s->authctxt->krb5_ccname);
1130 * Pull in any environment variables that may have
1133 if (options.use_pam) {
1136 p = fetch_pam_child_environment();
1137 copy_environment(p, &env, &envsize);
1138 free_pam_environment(p);
1140 p = fetch_pam_environment();
1141 copy_environment(p, &env, &envsize);
1142 free_pam_environment(p);
1144 #endif /* USE_PAM */
1146 if (auth_sock_name != NULL)
1147 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1150 /* read $HOME/.ssh/environment. */
1151 if (options.permit_user_env && !options.use_login) {
1152 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1153 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1154 read_environment_file(&env, &envsize, buf);
1157 /* dump the environment */
1158 fprintf(stderr, "Environment:\n");
1159 for (i = 0; env[i]; i++)
1160 fprintf(stderr, " %.200s\n", env[i]);
1166 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1167 * first in this order).
1170 do_rc_files(Session *s, const char *shell)
1178 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1180 /* ignore _PATH_SSH_USER_RC for subsystems */
1181 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1182 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1183 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1185 fprintf(stderr, "Running %s\n", cmd);
1186 f = popen(cmd, "w");
1189 fprintf(f, "%s %s\n", s->auth_proto,
1193 fprintf(stderr, "Could not run %s\n",
1195 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1197 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1198 _PATH_SSH_SYSTEM_RC);
1199 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1202 fprintf(f, "%s %s\n", s->auth_proto,
1206 fprintf(stderr, "Could not run %s\n",
1207 _PATH_SSH_SYSTEM_RC);
1208 } else if (do_xauth && options.xauth_location != NULL) {
1209 /* Add authority data to .Xauthority if appropriate. */
1212 "Running %.500s remove %.100s\n",
1213 options.xauth_location, s->auth_display);
1215 "%.500s add %.100s %.100s %.100s\n",
1216 options.xauth_location, s->auth_display,
1217 s->auth_proto, s->auth_data);
1219 snprintf(cmd, sizeof cmd, "%s -q -",
1220 options.xauth_location);
1221 f = popen(cmd, "w");
1223 fprintf(f, "remove %s\n",
1225 fprintf(f, "add %s %s %s\n",
1226 s->auth_display, s->auth_proto,
1230 fprintf(stderr, "Could not run %s\n",
1237 do_nologin(struct passwd *pw)
1242 #ifdef HAVE_LOGIN_CAP
1243 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1244 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1245 _PATH_NOLOGIN), "r");
1248 f = fopen(_PATH_NOLOGIN, "r");
1251 /* /etc/nologin exists. Print its contents and exit. */
1252 logit("User %.100s not allowed because %s exists",
1253 pw->pw_name, _PATH_NOLOGIN);
1254 while (fgets(buf, sizeof(buf), f))
1262 /* Set login name, uid, gid, and groups. */
1264 do_setusercontext(struct passwd *pw)
1267 if (getuid() == 0 || geteuid() == 0)
1268 #endif /* HAVE_CYGWIN */
1271 #ifdef HAVE_SETPCRED
1272 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1273 fatal("Failed to set process credentials");
1274 #endif /* HAVE_SETPCRED */
1275 #ifdef HAVE_LOGIN_CAP
1280 if (options.gss_authentication) {
1281 temporarily_use_uid(pw);
1282 ssh_gssapi_storecreds();
1287 if (options.use_pam) {
1291 # endif /* USE_PAM */
1292 if (setusercontext(lc, pw, pw->pw_uid,
1293 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1294 perror("unable to set user context");
1298 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1299 /* Sets login uid for accounting */
1300 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1301 error("setluid: %s", strerror(errno));
1302 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1304 if (setlogin(pw->pw_name) < 0)
1305 error("setlogin failed: %s", strerror(errno));
1306 if (setgid(pw->pw_gid) < 0) {
1310 /* Initialize the group list. */
1311 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1312 perror("initgroups");
1317 if (options.gss_authentication) {
1318 temporarily_use_uid(pw);
1319 ssh_gssapi_storecreds();
1325 * PAM credentials may take the form of supplementary groups.
1326 * These will have been wiped by the above initgroups() call.
1327 * Reestablish them here.
1329 if (options.use_pam) {
1333 # endif /* USE_PAM */
1334 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1335 irix_setusercontext(pw);
1336 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1340 #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
1341 if (set_id(pw->pw_name) != 0) {
1344 #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
1345 /* Permanently switch to the desired uid. */
1346 permanently_set_uid(pw);
1353 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1354 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1357 ssh_selinux_setup_exec_context(pw->pw_name);
1362 do_pwchange(Session *s)
1365 fprintf(stderr, "WARNING: Your password has expired.\n");
1366 if (s->ttyfd != -1) {
1368 "You must change your password now and login again!\n");
1369 #ifdef PASSWD_NEEDS_USERNAME
1370 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1373 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1378 "Password change required but no TTY available.\n");
1384 launch_login(struct passwd *pw, const char *hostname)
1386 /* Launch login(1). */
1388 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1389 #ifdef xxxLOGIN_NEEDS_TERM
1390 (s->term ? s->term : "unknown"),
1391 #endif /* LOGIN_NEEDS_TERM */
1392 #ifdef LOGIN_NO_ENDOPT
1393 "-p", "-f", pw->pw_name, (char *)NULL);
1395 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1398 /* Login couldn't be executed, die. */
1405 child_close_fds(void)
1409 if (packet_get_connection_in() == packet_get_connection_out())
1410 close(packet_get_connection_in());
1412 close(packet_get_connection_in());
1413 close(packet_get_connection_out());
1416 * Close all descriptors related to channels. They will still remain
1417 * open in the parent.
1419 /* XXX better use close-on-exec? -markus */
1420 channel_close_all();
1423 * Close any extra file descriptors. Note that there may still be
1424 * descriptors left by system functions. They will be closed later.
1429 * Close any extra open file descriptors so that we don't have them
1430 * hanging around in clients. Note that we want to do this after
1431 * initgroups, because at least on Solaris 2.3 it leaves file
1434 for (i = 3; i < 64; i++)
1439 * Performs common processing for the child, such as setting up the
1440 * environment, closing extra file descriptors, setting the user and group
1441 * ids, and executing the command or shell.
1444 do_child(Session *s, const char *command)
1446 extern char **environ;
1449 const char *shell, *shell0, *hostname = NULL;
1450 struct passwd *pw = s->pw;
1452 /* remove hostkey from the child's memory */
1453 destroy_sensitive_data();
1455 /* Force a password change */
1456 if (s->authctxt->force_pwchange) {
1457 do_setusercontext(pw);
1463 /* login(1) is only called if we execute the login shell */
1464 if (options.use_login && command != NULL)
1465 options.use_login = 0;
1468 cray_setup(pw->pw_uid, pw->pw_name, command);
1469 #endif /* _UNICOS */
1472 * Login(1) does this as well, and it needs uid 0 for the "-h"
1473 * switch, so we let login(1) to this for us.
1475 if (!options.use_login) {
1477 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1478 if (!check_quietlogin(s, command))
1480 #else /* HAVE_OSF_SIA */
1481 /* When PAM is enabled we rely on it to do the nologin check */
1482 if (!options.use_pam)
1484 do_setusercontext(pw);
1486 * PAM session modules in do_setusercontext may have
1487 * generated messages, so if this in an interactive
1488 * login then display them too.
1490 if (!check_quietlogin(s, command))
1492 #endif /* HAVE_OSF_SIA */
1496 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1497 debug3("PAM session not opened, exiting");
1504 * Get the shell from the password data. An empty shell field is
1505 * legal, and means /bin/sh.
1507 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1510 * Make sure $SHELL points to the shell from the password file,
1511 * even if shell is overridden from login.conf
1513 env = do_setup_env(s, shell);
1515 #ifdef HAVE_LOGIN_CAP
1516 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1519 /* we have to stash the hostname before we close our socket. */
1520 if (options.use_login)
1521 hostname = get_remote_name_or_ip(utmp_len,
1524 * Close the connection descriptors; note that this is the child, and
1525 * the server will still have the socket open, and it is important
1526 * that we do not shutdown it. Note that the descriptors cannot be
1527 * closed before building the environment, as we call
1528 * get_remote_ipaddr there.
1533 * Must take new environment into use so that .ssh/rc,
1534 * /etc/ssh/sshrc and xauth are run in the proper environment.
1538 #if defined(KRB5) && defined(USE_AFS)
1540 * At this point, we check to see if AFS is active and if we have
1541 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1542 * if we can (and need to) extend the ticket into an AFS token. If
1543 * we don't do this, we run into potential problems if the user's
1544 * home directory is in AFS and it's not world-readable.
1547 if (options.kerberos_get_afs_token && k_hasafs() &&
1548 (s->authctxt->krb5_ctx != NULL)) {
1551 debug("Getting AFS token");
1555 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1556 krb5_afslog(s->authctxt->krb5_ctx,
1557 s->authctxt->krb5_fwd_ccache, cell, NULL);
1559 krb5_afslog_home(s->authctxt->krb5_ctx,
1560 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1564 /* Change current directory to the user's home directory. */
1565 if (chdir(pw->pw_dir) < 0) {
1566 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1567 pw->pw_dir, strerror(errno));
1568 #ifdef HAVE_LOGIN_CAP
1569 if (login_getcapbool(lc, "requirehome", 0))
1574 if (!options.use_login)
1575 do_rc_files(s, shell);
1577 /* restore SIGPIPE for child */
1578 signal(SIGPIPE, SIG_DFL);
1580 if (options.use_login) {
1581 launch_login(pw, hostname);
1585 /* Get the last component of the shell name. */
1586 if ((shell0 = strrchr(shell, '/')) != NULL)
1592 * If we have no command, execute the shell. In this case, the shell
1593 * name to be passed in argv[0] is preceded by '-' to indicate that
1594 * this is a login shell.
1599 /* Start the shell. Set initial character to '-'. */
1602 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1603 >= sizeof(argv0) - 1) {
1609 /* Execute the shell. */
1612 execve(shell, argv, env);
1614 /* Executing the shell failed. */
1619 * Execute the command using the user's shell. This uses the -c
1620 * option to execute the command.
1622 argv[0] = (char *) shell0;
1624 argv[2] = (char *) command;
1626 execve(shell, argv, env);
1635 static int did_init = 0;
1637 debug("session_new: init");
1638 for (i = 0; i < MAX_SESSIONS; i++) {
1639 sessions[i].used = 0;
1643 for (i = 0; i < MAX_SESSIONS; i++) {
1644 Session *s = &sessions[i];
1646 memset(s, 0, sizeof(*s));
1652 s->x11_chanids = NULL;
1653 debug("session_new: session %d", i);
1664 for (i = 0; i < MAX_SESSIONS; i++) {
1665 Session *s = &sessions[i];
1666 debug("dump: used %d session %d %p channel %d pid %ld",
1676 session_open(Authctxt *authctxt, int chanid)
1678 Session *s = session_new();
1679 debug("session_open: channel %d", chanid);
1681 error("no more sessions");
1684 s->authctxt = authctxt;
1685 s->pw = authctxt->pw;
1686 if (s->pw == NULL || !authctxt->valid)
1687 fatal("no user for session %d", s->self);
1688 debug("session_open: session %d: link with channel %d", s->self, chanid);
1694 session_by_tty(char *tty)
1697 for (i = 0; i < MAX_SESSIONS; i++) {
1698 Session *s = &sessions[i];
1699 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1700 debug("session_by_tty: session %d tty %s", i, tty);
1704 debug("session_by_tty: unknown tty %.100s", tty);
1710 session_by_channel(int id)
1713 for (i = 0; i < MAX_SESSIONS; i++) {
1714 Session *s = &sessions[i];
1715 if (s->used && s->chanid == id) {
1716 debug("session_by_channel: session %d channel %d", i, id);
1720 debug("session_by_channel: unknown channel %d", id);
1726 session_by_x11_channel(int id)
1730 for (i = 0; i < MAX_SESSIONS; i++) {
1731 Session *s = &sessions[i];
1733 if (s->x11_chanids == NULL || !s->used)
1735 for (j = 0; s->x11_chanids[j] != -1; j++) {
1736 if (s->x11_chanids[j] == id) {
1737 debug("session_by_x11_channel: session %d "
1738 "channel %d", s->self, id);
1743 debug("session_by_x11_channel: unknown channel %d", id);
1749 session_by_pid(pid_t pid)
1752 debug("session_by_pid: pid %ld", (long)pid);
1753 for (i = 0; i < MAX_SESSIONS; i++) {
1754 Session *s = &sessions[i];
1755 if (s->used && s->pid == pid)
1758 error("session_by_pid: unknown pid %ld", (long)pid);
1764 session_window_change_req(Session *s)
1766 s->col = packet_get_int();
1767 s->row = packet_get_int();
1768 s->xpixel = packet_get_int();
1769 s->ypixel = packet_get_int();
1771 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1776 session_pty_req(Session *s)
1782 debug("Allocating a pty not permitted for this authentication.");
1785 if (s->ttyfd != -1) {
1786 packet_disconnect("Protocol error: you already have a pty.");
1790 s->term = packet_get_string(&len);
1793 s->col = packet_get_int();
1794 s->row = packet_get_int();
1796 s->row = packet_get_int();
1797 s->col = packet_get_int();
1799 s->xpixel = packet_get_int();
1800 s->ypixel = packet_get_int();
1802 if (strcmp(s->term, "") == 0) {
1807 /* Allocate a pty and open it. */
1808 debug("Allocating pty.");
1809 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1815 error("session_pty_req: session %d alloc failed", s->self);
1818 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1820 /* for SSH1 the tty modes length is not given */
1822 n_bytes = packet_remaining();
1823 tty_parse_modes(s->ttyfd, &n_bytes);
1826 pty_setowner(s->pw, s->tty);
1828 /* Set window size from the packet. */
1829 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1832 session_proctitle(s);
1837 session_subsystem_req(Session *s)
1842 char *cmd, *subsys = packet_get_string(&len);
1846 logit("subsystem request for %.100s", subsys);
1848 for (i = 0; i < options.num_subsystems; i++) {
1849 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1850 cmd = options.subsystem_command[i];
1851 if (stat(cmd, &st) < 0) {
1852 error("subsystem: cannot stat %s: %s", cmd,
1856 debug("subsystem: exec() %s", cmd);
1857 s->is_subsystem = 1;
1865 logit("subsystem request for %.100s failed, subsystem not found",
1873 session_x11_req(Session *s)
1877 if (s->auth_proto != NULL || s->auth_data != NULL) {
1878 error("session_x11_req: session %d: "
1879 "x11 forwarding already active", s->self);
1882 s->single_connection = packet_get_char();
1883 s->auth_proto = packet_get_string(NULL);
1884 s->auth_data = packet_get_string(NULL);
1885 s->screen = packet_get_int();
1888 success = session_setup_x11fwd(s);
1890 xfree(s->auth_proto);
1891 xfree(s->auth_data);
1892 s->auth_proto = NULL;
1893 s->auth_data = NULL;
1899 session_shell_req(Session *s)
1907 session_exec_req(Session *s)
1910 char *command = packet_get_string(&len);
1912 do_exec(s, command);
1918 session_break_req(Session *s)
1921 packet_get_int(); /* ignored */
1924 if (s->ttyfd == -1 ||
1925 tcsendbreak(s->ttyfd, 0) < 0)
1931 session_env_req(Session *s)
1934 u_int name_len, val_len, i;
1936 name = packet_get_string(&name_len);
1937 val = packet_get_string(&val_len);
1940 /* Don't set too many environment variables */
1941 if (s->num_env > 128) {
1942 debug2("Ignoring env request %s: too many env vars", name);
1946 for (i = 0; i < options.num_accept_env; i++) {
1947 if (match_pattern(name, options.accept_env[i])) {
1948 debug2("Setting env %d: %s=%s", s->num_env, name, val);
1949 s->env = xrealloc(s->env, s->num_env + 1,
1951 s->env[s->num_env].name = name;
1952 s->env[s->num_env].val = val;
1957 debug2("Ignoring env request %s: disallowed name", name);
1966 session_auth_agent_req(Session *s)
1968 static int called = 0;
1970 if (no_agent_forwarding_flag) {
1971 debug("session_auth_agent_req: no_agent_forwarding_flag");
1978 return auth_input_request_forwarding(s->pw);
1983 session_input_channel_req(Channel *c, const char *rtype)
1988 if ((s = session_by_channel(c->self)) == NULL) {
1989 logit("session_input_channel_req: no session %d req %.100s",
1993 debug("session_input_channel_req: session %d req %s", s->self, rtype);
1996 * a session is in LARVAL state until a shell, a command
1997 * or a subsystem is executed
1999 if (c->type == SSH_CHANNEL_LARVAL) {
2000 if (strcmp(rtype, "shell") == 0) {
2001 success = session_shell_req(s);
2002 } else if (strcmp(rtype, "exec") == 0) {
2003 success = session_exec_req(s);
2004 } else if (strcmp(rtype, "pty-req") == 0) {
2005 success = session_pty_req(s);
2006 } else if (strcmp(rtype, "x11-req") == 0) {
2007 success = session_x11_req(s);
2008 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2009 success = session_auth_agent_req(s);
2010 } else if (strcmp(rtype, "subsystem") == 0) {
2011 success = session_subsystem_req(s);
2012 } else if (strcmp(rtype, "env") == 0) {
2013 success = session_env_req(s);
2016 if (strcmp(rtype, "window-change") == 0) {
2017 success = session_window_change_req(s);
2018 } else if (strcmp(rtype, "break") == 0) {
2019 success = session_break_req(s);
2026 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2029 fatal("session_set_fds: called for proto != 2.0");
2031 * now that have a child and a pipe to the child,
2032 * we can activate our channel and register the fd's
2034 if (s->chanid == -1)
2035 fatal("no channel for session %d", s->self);
2036 channel_set_fds(s->chanid,
2038 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2040 CHAN_SES_WINDOW_DEFAULT);
2044 * Function to perform pty cleanup. Also called if we get aborted abnormally
2045 * (e.g., due to a dropped connection).
2048 session_pty_cleanup2(Session *s)
2051 error("session_pty_cleanup: no session");
2057 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2059 /* Record that the user has logged out. */
2061 record_logout(s->pid, s->tty, s->pw->pw_name);
2063 /* Release the pseudo-tty. */
2065 pty_release(s->tty);
2068 * Close the server side of the socket pairs. We must do this after
2069 * the pty cleanup, so that another process doesn't get this pty
2070 * while we're still cleaning up.
2072 if (close(s->ptymaster) < 0)
2073 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2075 /* unlink pty from session */
2080 session_pty_cleanup(Session *s)
2082 PRIVSEP(session_pty_cleanup2(s));
2088 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2103 return "SIG@openssh.com";
2107 session_close_x11(int id)
2111 if ((c = channel_by_id(id)) == NULL) {
2112 debug("session_close_x11: x11 channel %d missing", id);
2114 /* Detach X11 listener */
2115 debug("session_close_x11: detach x11 channel %d", id);
2116 channel_cancel_cleanup(id);
2117 if (c->ostate != CHAN_OUTPUT_CLOSED)
2123 session_close_single_x11(int id, void *arg)
2128 debug3("session_close_single_x11: channel %d", id);
2129 channel_cancel_cleanup(id);
2130 if ((s = session_by_x11_channel(id)) == NULL)
2131 fatal("session_close_single_x11: no x11 channel %d", id);
2132 for (i = 0; s->x11_chanids[i] != -1; i++) {
2133 debug("session_close_single_x11: session %d: "
2134 "closing channel %d", s->self, s->x11_chanids[i]);
2136 * The channel "id" is already closing, but make sure we
2137 * close all of its siblings.
2139 if (s->x11_chanids[i] != id)
2140 session_close_x11(s->x11_chanids[i]);
2142 xfree(s->x11_chanids);
2143 s->x11_chanids = NULL;
2148 if (s->auth_proto) {
2149 xfree(s->auth_proto);
2150 s->auth_proto = NULL;
2153 xfree(s->auth_data);
2154 s->auth_data = NULL;
2156 if (s->auth_display) {
2157 xfree(s->auth_display);
2158 s->auth_display = NULL;
2163 session_exit_message(Session *s, int status)
2167 if ((c = channel_lookup(s->chanid)) == NULL)
2168 fatal("session_exit_message: session %d: no channel %d",
2169 s->self, s->chanid);
2170 debug("session_exit_message: session %d channel %d pid %ld",
2171 s->self, s->chanid, (long)s->pid);
2173 if (WIFEXITED(status)) {
2174 channel_request_start(s->chanid, "exit-status", 0);
2175 packet_put_int(WEXITSTATUS(status));
2177 } else if (WIFSIGNALED(status)) {
2178 channel_request_start(s->chanid, "exit-signal", 0);
2179 packet_put_cstring(sig2name(WTERMSIG(status)));
2181 packet_put_char(WCOREDUMP(status));
2182 #else /* WCOREDUMP */
2184 #endif /* WCOREDUMP */
2185 packet_put_cstring("");
2186 packet_put_cstring("");
2189 /* Some weird exit cause. Just exit. */
2190 packet_disconnect("wait returned status %04x.", status);
2193 /* disconnect channel */
2194 debug("session_exit_message: release channel %d", s->chanid);
2197 * Adjust cleanup callback attachment to send close messages when
2198 * the channel gets EOF. The session will be then be closed
2199 * by session_close_by_channel when the childs close their fds.
2201 channel_register_cleanup(c->self, session_close_by_channel, 1);
2204 * emulate a write failure with 'chan_write_failed', nobody will be
2205 * interested in data we write.
2206 * Note that we must not call 'chan_read_failed', since there could
2207 * be some more data waiting in the pipe.
2209 if (c->ostate != CHAN_OUTPUT_CLOSED)
2210 chan_write_failed(c);
2214 session_close(Session *s)
2218 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2220 session_pty_cleanup(s);
2226 xfree(s->x11_chanids);
2227 if (s->auth_display)
2228 xfree(s->auth_display);
2230 xfree(s->auth_data);
2232 xfree(s->auth_proto);
2234 for (i = 0; i < s->num_env; i++) {
2235 xfree(s->env[i].name);
2236 xfree(s->env[i].val);
2240 session_proctitle(s);
2244 session_close_by_pid(pid_t pid, int status)
2246 Session *s = session_by_pid(pid);
2248 debug("session_close_by_pid: no session for pid %ld",
2252 if (s->chanid != -1)
2253 session_exit_message(s, status);
2255 session_pty_cleanup(s);
2260 * this is called when a channel dies before
2261 * the session 'child' itself dies
2264 session_close_by_channel(int id, void *arg)
2266 Session *s = session_by_channel(id);
2270 debug("session_close_by_channel: no session for id %d", id);
2273 debug("session_close_by_channel: channel %d child %ld",
2276 debug("session_close_by_channel: channel %d: has child", id);
2278 * delay detach of session, but release pty, since
2279 * the fd's to the child are already closed
2282 session_pty_cleanup(s);
2285 /* detach by removing callback */
2286 channel_cancel_cleanup(s->chanid);
2288 /* Close any X11 listeners associated with this session */
2289 if (s->x11_chanids != NULL) {
2290 for (i = 0; s->x11_chanids[i] != -1; i++) {
2291 session_close_x11(s->x11_chanids[i]);
2292 s->x11_chanids[i] = -1;
2301 session_destroy_all(void (*closefunc)(Session *))
2304 for (i = 0; i < MAX_SESSIONS; i++) {
2305 Session *s = &sessions[i];
2307 if (closefunc != NULL)
2316 session_tty_list(void)
2318 static char buf[1024];
2323 for (i = 0; i < MAX_SESSIONS; i++) {
2324 Session *s = &sessions[i];
2325 if (s->used && s->ttyfd != -1) {
2327 if (strncmp(s->tty, "/dev/", 5) != 0) {
2328 cp = strrchr(s->tty, '/');
2329 cp = (cp == NULL) ? s->tty : cp + 1;
2334 strlcat(buf, ",", sizeof buf);
2335 strlcat(buf, cp, sizeof buf);
2339 strlcpy(buf, "notty", sizeof buf);
2344 session_proctitle(Session *s)
2347 error("no user for session %d", s->self);
2349 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2353 session_setup_x11fwd(Session *s)
2356 char display[512], auth_display[512];
2357 char hostname[MAXHOSTNAMELEN];
2360 if (no_x11_forwarding_flag) {
2361 packet_send_debug("X11 forwarding disabled in user configuration file.");
2364 if (!options.x11_forwarding) {
2365 debug("X11 forwarding disabled in server configuration file.");
2368 if (!options.xauth_location ||
2369 (stat(options.xauth_location, &st) == -1)) {
2370 packet_send_debug("No xauth program; cannot forward with spoofing.");
2373 if (options.use_login) {
2374 packet_send_debug("X11 forwarding disabled; "
2375 "not compatible with UseLogin=yes.");
2378 if (s->display != NULL) {
2379 debug("X11 display already set.");
2382 if (x11_create_display_inet(options.x11_display_offset,
2383 options.x11_use_localhost, s->single_connection,
2384 &s->display_number, &s->x11_chanids) == -1) {
2385 debug("x11_create_display_inet failed.");
2388 for (i = 0; s->x11_chanids[i] != -1; i++) {
2389 channel_register_cleanup(s->x11_chanids[i],
2390 session_close_single_x11, 0);
2393 /* Set up a suitable value for the DISPLAY variable. */
2394 if (gethostname(hostname, sizeof(hostname)) < 0)
2395 fatal("gethostname: %.100s", strerror(errno));
2397 * auth_display must be used as the displayname when the
2398 * authorization entry is added with xauth(1). This will be
2399 * different than the DISPLAY string for localhost displays.
2401 if (options.x11_use_localhost) {
2402 snprintf(display, sizeof display, "localhost:%u.%u",
2403 s->display_number, s->screen);
2404 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2405 s->display_number, s->screen);
2406 s->display = xstrdup(display);
2407 s->auth_display = xstrdup(auth_display);
2409 #ifdef IPADDR_IN_DISPLAY
2411 struct in_addr my_addr;
2413 he = gethostbyname(hostname);
2415 error("Can't get IP address for X11 DISPLAY.");
2416 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2419 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2420 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2421 s->display_number, s->screen);
2423 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2424 s->display_number, s->screen);
2426 s->display = xstrdup(display);
2427 s->auth_display = xstrdup(display);
2434 do_authenticated2(Authctxt *authctxt)
2436 server_loop2(authctxt);
2440 do_cleanup(Authctxt *authctxt)
2442 static int called = 0;
2444 debug("do_cleanup");
2446 /* no cleanup if we're in the child for login shell */
2450 /* avoid double cleanup */
2455 if (authctxt == NULL)
2458 if (options.kerberos_ticket_cleanup &&
2460 krb5_cleanup_proc(authctxt);
2464 if (compat20 && options.gss_cleanup_creds)
2465 ssh_gssapi_cleanup_creds();
2469 if (options.use_pam) {
2471 sshpam_thread_cleanup();
2475 /* remove agent socket */
2476 auth_sock_cleanup_proc(authctxt->pw);
2479 * Cleanup ptys/utmp only if privsep is disabled,
2480 * or if running in monitor.
2482 if (!use_privsep || mm_is_monitor())
2483 session_destroy_all(session_pty_cleanup2);