2 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * As far as I am concerned, the code I have written for this software
6 * can be used freely for any purpose. Any derived versions of this
7 * software must be clearly marked as such, and if the derived work is
8 * incompatible with the protocol description in the RFC file, it must be
9 * called by a name other than "ssh" or "Secure Shell".
11 * SSH2 support by Markus Friedl.
12 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 RCSID("$OpenBSD: session.c,v 1.196 2006/02/20 17:19:54 stevesk Exp $");
38 #include <sys/types.h>
39 #ifdef HAVE_SYS_STAT_H
40 # include <sys/stat.h>
61 #include "auth-options.h"
62 #include "pathnames.h"
66 #include "serverloop.h"
70 #include "monitor_wrap.h"
72 #if defined(KRB5) && defined(USE_AFS)
82 Session *session_new(void);
83 void session_set_fds(Session *, int, int, int);
84 void session_pty_cleanup(Session *);
85 void session_proctitle(Session *);
86 int session_setup_x11fwd(Session *);
87 void do_exec_pty(Session *, const char *);
88 void do_exec_no_pty(Session *, const char *);
89 void do_exec(Session *, const char *);
90 void do_login(Session *, const char *);
91 #ifdef LOGIN_NEEDS_UTMPX
92 static void do_pre_login(Session *s);
94 void do_child(Session *, const char *);
96 int check_quietlogin(Session *, const char *);
98 static void do_authenticated1(Authctxt *);
99 static void do_authenticated2(Authctxt *);
101 static int session_pty_req(Session *);
104 extern ServerOptions options;
105 extern char *__progname;
106 extern int log_stderr;
107 extern int debug_flag;
108 extern u_int utmp_len;
109 extern int startup_pipe;
110 extern void destroy_sensitive_data(void);
111 extern Buffer loginmsg;
113 /* original command from peer. */
114 const char *original_command = NULL;
117 #define MAX_SESSIONS 10
118 Session sessions[MAX_SESSIONS];
120 #ifdef HAVE_LOGIN_CAP
124 static int is_child = 0;
126 /* Name and directory of socket for authentication agent forwarding. */
127 static char *auth_sock_name = NULL;
128 static char *auth_sock_dir = NULL;
130 /* removes the agent forwarding socket */
133 auth_sock_cleanup_proc(struct passwd *pw)
135 if (auth_sock_name != NULL) {
136 temporarily_use_uid(pw);
137 unlink(auth_sock_name);
138 rmdir(auth_sock_dir);
139 auth_sock_name = NULL;
145 auth_input_request_forwarding(struct passwd * pw)
149 struct sockaddr_un sunaddr;
151 if (auth_sock_name != NULL) {
152 error("authentication forwarding requested twice.");
156 /* Temporarily drop privileged uid for mkdir/bind. */
157 temporarily_use_uid(pw);
159 /* Allocate a buffer for the socket name, and format the name. */
160 auth_sock_name = xmalloc(MAXPATHLEN);
161 auth_sock_dir = xmalloc(MAXPATHLEN);
162 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
164 /* Create private directory for socket */
165 if (mkdtemp(auth_sock_dir) == NULL) {
166 packet_send_debug("Agent forwarding disabled: "
167 "mkdtemp() failed: %.100s", strerror(errno));
169 xfree(auth_sock_name);
170 xfree(auth_sock_dir);
171 auth_sock_name = NULL;
172 auth_sock_dir = NULL;
175 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
176 auth_sock_dir, (long) getpid());
178 /* Create the socket. */
179 sock = socket(AF_UNIX, SOCK_STREAM, 0);
181 packet_disconnect("socket: %.100s", strerror(errno));
183 /* Bind it to the name. */
184 memset(&sunaddr, 0, sizeof(sunaddr));
185 sunaddr.sun_family = AF_UNIX;
186 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
188 if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
189 packet_disconnect("bind: %.100s", strerror(errno));
191 /* Restore the privileged uid. */
194 /* Start listening on the socket. */
195 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
196 packet_disconnect("listen: %.100s", strerror(errno));
198 /* Allocate a channel for the authentication agent socket. */
199 nc = channel_new("auth socket",
200 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
201 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
202 0, "auth socket", 1);
203 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
208 display_loginmsg(void)
210 if (buffer_len(&loginmsg) > 0) {
211 buffer_append(&loginmsg, "\0", 1);
212 printf("%s", (char *)buffer_ptr(&loginmsg));
213 buffer_clear(&loginmsg);
218 do_authenticated(Authctxt *authctxt)
220 setproctitle("%s", authctxt->pw->pw_name);
222 /* setup the channel layer */
223 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
224 channel_permit_all_opens();
227 do_authenticated2(authctxt);
229 do_authenticated1(authctxt);
231 do_cleanup(authctxt);
235 * Prepares for an interactive session. This is called after the user has
236 * been successfully authenticated. During this message exchange, pseudo
237 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
238 * are requested, etc.
241 do_authenticated1(Authctxt *authctxt)
245 int success, type, screen_flag;
246 int enable_compression_after_reply = 0;
247 u_int proto_len, data_len, dlen, compression_level = 0;
251 error("no more sessions");
254 s->authctxt = authctxt;
255 s->pw = authctxt->pw;
258 * We stay in this loop until the client requests to execute a shell
264 /* Get a packet from the client. */
265 type = packet_read();
267 /* Process the packet. */
269 case SSH_CMSG_REQUEST_COMPRESSION:
270 compression_level = packet_get_int();
272 if (compression_level < 1 || compression_level > 9) {
273 packet_send_debug("Received invalid compression level %d.",
277 if (options.compression == COMP_NONE) {
278 debug2("compression disabled");
281 /* Enable compression after we have responded with SUCCESS. */
282 enable_compression_after_reply = 1;
286 case SSH_CMSG_REQUEST_PTY:
287 success = session_pty_req(s);
290 case SSH_CMSG_X11_REQUEST_FORWARDING:
291 s->auth_proto = packet_get_string(&proto_len);
292 s->auth_data = packet_get_string(&data_len);
294 screen_flag = packet_get_protocol_flags() &
295 SSH_PROTOFLAG_SCREEN_NUMBER;
296 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
298 if (packet_remaining() == 4) {
300 debug2("Buggy client: "
301 "X11 screen flag missing");
302 s->screen = packet_get_int();
307 success = session_setup_x11fwd(s);
309 xfree(s->auth_proto);
311 s->auth_proto = NULL;
316 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
317 if (no_agent_forwarding_flag || compat13) {
318 debug("Authentication agent forwarding not permitted for this authentication.");
321 debug("Received authentication agent forwarding request.");
322 success = auth_input_request_forwarding(s->pw);
325 case SSH_CMSG_PORT_FORWARD_REQUEST:
326 if (no_port_forwarding_flag) {
327 debug("Port forwarding not permitted for this authentication.");
330 if (!options.allow_tcp_forwarding) {
331 debug("Port forwarding not permitted.");
334 debug("Received TCP/IP port forwarding request.");
335 channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
339 case SSH_CMSG_MAX_PACKET_SIZE:
340 if (packet_set_maxsize(packet_get_int()) > 0)
344 case SSH_CMSG_EXEC_SHELL:
345 case SSH_CMSG_EXEC_CMD:
346 if (type == SSH_CMSG_EXEC_CMD) {
347 command = packet_get_string(&dlen);
348 debug("Exec command '%.500s'", command);
360 * Any unknown messages in this phase are ignored,
361 * and a failure message is returned.
363 logit("Unknown packet type received after authentication: %d", type);
365 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
369 /* Enable compression now that we have replied if appropriate. */
370 if (enable_compression_after_reply) {
371 enable_compression_after_reply = 0;
372 packet_start_compression(compression_level);
378 * This is called to fork and execute a command when we have no tty. This
379 * will call do_child from the child, and server_loop from the parent after
380 * setting up file descriptors and such.
383 do_exec_no_pty(Session *s, const char *command)
388 int pin[2], pout[2], perr[2];
389 /* Allocate pipes for communicating with the program. */
390 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
391 packet_disconnect("Could not create pipes: %.100s",
393 #else /* USE_PIPES */
394 int inout[2], err[2];
395 /* Uses socket pairs to communicate with the program. */
396 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
397 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
398 packet_disconnect("Could not create socket pairs: %.100s",
400 #endif /* USE_PIPES */
402 fatal("do_exec_no_pty: no session");
404 session_proctitle(s);
407 if (options.use_pam && !use_privsep)
411 /* Fork the child. */
412 if ((pid = fork()) == 0) {
415 /* Child. Reinitialize the log since the pid has changed. */
416 log_init(__progname, options.log_level, options.log_facility, log_stderr);
419 * Create a new session and process group since the 4.4BSD
420 * setlogin() affects the entire process group.
423 error("setsid failed: %.100s", strerror(errno));
427 * Redirect stdin. We close the parent side of the socket
428 * pair, and make the child side the standard input.
431 if (dup2(pin[0], 0) < 0)
432 perror("dup2 stdin");
435 /* Redirect stdout. */
437 if (dup2(pout[1], 1) < 0)
438 perror("dup2 stdout");
441 /* Redirect stderr. */
443 if (dup2(perr[1], 2) < 0)
444 perror("dup2 stderr");
446 #else /* USE_PIPES */
448 * Redirect stdin, stdout, and stderr. Stdin and stdout will
449 * use the same socket, as some programs (particularly rdist)
450 * seem to depend on it.
454 if (dup2(inout[0], 0) < 0) /* stdin */
455 perror("dup2 stdin");
456 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
457 perror("dup2 stdout");
458 if (dup2(err[0], 2) < 0) /* stderr */
459 perror("dup2 stderr");
460 #endif /* USE_PIPES */
463 cray_init_job(s->pw); /* set up cray jid and tmpdir */
466 /* Do processing for the child (exec command etc). */
467 do_child(s, command);
471 signal(WJSIGNAL, cray_job_termination_handler);
475 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
478 packet_disconnect("fork failed: %.100s", strerror(errno));
480 /* Set interactive/non-interactive mode. */
481 packet_set_interactive(s->display != NULL);
483 /* We are the parent. Close the child sides of the pipes. */
489 if (s->is_subsystem) {
493 session_set_fds(s, pin[1], pout[0], perr[0]);
495 /* Enter the interactive session. */
496 server_loop(pid, pin[1], pout[0], perr[0]);
497 /* server_loop has closed pin[1], pout[0], and perr[0]. */
499 #else /* USE_PIPES */
500 /* We are the parent. Close the child sides of the socket pairs. */
505 * Clear loginmsg, since it's the child's responsibility to display
506 * it to the user, otherwise multiple sessions may accumulate
507 * multiple copies of the login messages.
509 buffer_clear(&loginmsg);
512 * Enter the interactive session. Note: server_loop must be able to
513 * handle the case that fdin and fdout are the same.
516 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
518 server_loop(pid, inout[1], inout[1], err[1]);
519 /* server_loop has closed inout[1] and err[1]. */
521 #endif /* USE_PIPES */
525 * This is called to fork and execute a command when we have a tty. This
526 * will call do_child from the child, and server_loop from the parent after
527 * setting up file descriptors, controlling tty, updating wtmp, utmp,
528 * lastlog, and other such operations.
531 do_exec_pty(Session *s, const char *command)
533 int fdout, ptyfd, ttyfd, ptymaster;
537 fatal("do_exec_pty: no session");
542 if (options.use_pam) {
543 do_pam_set_tty(s->tty);
549 /* Fork the child. */
550 if ((pid = fork()) == 0) {
553 /* Child. Reinitialize the log because the pid has changed. */
554 log_init(__progname, options.log_level, options.log_facility, log_stderr);
555 /* Close the master side of the pseudo tty. */
558 /* Make the pseudo tty our controlling tty. */
559 pty_make_controlling_tty(&ttyfd, s->tty);
561 /* Redirect stdin/stdout/stderr from the pseudo tty. */
562 if (dup2(ttyfd, 0) < 0)
563 error("dup2 stdin: %s", strerror(errno));
564 if (dup2(ttyfd, 1) < 0)
565 error("dup2 stdout: %s", strerror(errno));
566 if (dup2(ttyfd, 2) < 0)
567 error("dup2 stderr: %s", strerror(errno));
569 /* Close the extra descriptor for the pseudo tty. */
572 /* record login, etc. similar to login(1) */
574 if (!(options.use_login && command == NULL)) {
576 cray_init_job(s->pw); /* set up cray jid and tmpdir */
578 do_login(s, command);
580 # ifdef LOGIN_NEEDS_UTMPX
586 /* Do common processing for the child, such as execing the command. */
587 do_child(s, command);
591 signal(WJSIGNAL, cray_job_termination_handler);
595 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
598 packet_disconnect("fork failed: %.100s", strerror(errno));
601 /* Parent. Close the slave side of the pseudo tty. */
605 * Create another descriptor of the pty master side for use as the
606 * standard input. We could use the original descriptor, but this
607 * simplifies code in server_loop. The descriptor is bidirectional.
611 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
613 /* we keep a reference to the pty master */
614 ptymaster = dup(ptyfd);
616 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
617 s->ptymaster = ptymaster;
619 /* Enter interactive session. */
620 packet_set_interactive(1);
622 session_set_fds(s, ptyfd, fdout, -1);
624 server_loop(pid, ptyfd, fdout, -1);
625 /* server_loop _has_ closed ptyfd and fdout. */
629 #ifdef LOGIN_NEEDS_UTMPX
631 do_pre_login(Session *s)
634 struct sockaddr_storage from;
635 pid_t pid = getpid();
638 * Get IP address of client. If the connection is not a socket, let
639 * the address be 0.0.0.0.
641 memset(&from, 0, sizeof(from));
642 fromlen = sizeof(from);
643 if (packet_connection_is_on_socket()) {
644 if (getpeername(packet_get_connection_in(),
645 (struct sockaddr *) & from, &fromlen) < 0) {
646 debug("getpeername: %.100s", strerror(errno));
651 record_utmp_only(pid, s->tty, s->pw->pw_name,
652 get_remote_name_or_ip(utmp_len, options.use_dns),
653 (struct sockaddr *)&from, fromlen);
658 * This is called to fork and execute a command. If another command is
659 * to be forced, execute that instead.
662 do_exec(Session *s, const char *command)
664 if (forced_command) {
665 original_command = command;
666 command = forced_command;
667 debug("Forced command '%.900s'", command);
670 #ifdef SSH_AUDIT_EVENTS
672 PRIVSEP(audit_run_command(command));
673 else if (s->ttyfd == -1) {
674 char *shell = s->pw->pw_shell;
676 if (shell[0] == '\0') /* empty shell means /bin/sh */
678 PRIVSEP(audit_run_command(shell));
683 do_exec_pty(s, command);
685 do_exec_no_pty(s, command);
687 original_command = NULL;
690 * Clear loginmsg: it's the child's responsibility to display
691 * it to the user, otherwise multiple sessions may accumulate
692 * multiple copies of the login messages.
694 buffer_clear(&loginmsg);
697 /* administrative, login(1)-like work */
699 do_login(Session *s, const char *command)
702 struct sockaddr_storage from;
703 struct passwd * pw = s->pw;
704 pid_t pid = getpid();
707 * Get IP address of client. If the connection is not a socket, let
708 * the address be 0.0.0.0.
710 memset(&from, 0, sizeof(from));
711 fromlen = sizeof(from);
712 if (packet_connection_is_on_socket()) {
713 if (getpeername(packet_get_connection_in(),
714 (struct sockaddr *) & from, &fromlen) < 0) {
715 debug("getpeername: %.100s", strerror(errno));
720 /* Record that there was a login on that tty from the remote host. */
722 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
723 get_remote_name_or_ip(utmp_len,
725 (struct sockaddr *)&from, fromlen);
729 * If password change is needed, do it now.
730 * This needs to occur before the ~/.hushlogin check.
732 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
735 s->authctxt->force_pwchange = 0;
736 /* XXX - signal [net] parent to enable forwardings */
740 if (check_quietlogin(s, command))
749 * Display the message of the day.
757 if (options.print_motd) {
758 #ifdef HAVE_LOGIN_CAP
759 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
762 f = fopen("/etc/motd", "r");
765 while (fgets(buf, sizeof(buf), f))
774 * Check for quiet login, either .hushlogin or command given.
777 check_quietlogin(Session *s, const char *command)
780 struct passwd *pw = s->pw;
783 /* Return 1 if .hushlogin exists or a command given. */
786 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
787 #ifdef HAVE_LOGIN_CAP
788 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
791 if (stat(buf, &st) >= 0)
798 * Sets the value of the given variable in the environment. If the variable
799 * already exists, its value is overriden.
802 child_set_env(char ***envp, u_int *envsizep, const char *name,
810 * If we're passed an uninitialized list, allocate a single null
811 * entry before continuing.
813 if (*envp == NULL && *envsizep == 0) {
814 *envp = xmalloc(sizeof(char *));
820 * Find the slot where the value should be stored. If the variable
821 * already exists, we reuse the slot; otherwise we append a new slot
822 * at the end of the array, expanding if necessary.
825 namelen = strlen(name);
826 for (i = 0; env[i]; i++)
827 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
830 /* Reuse the slot. */
833 /* New variable. Expand if necessary. */
835 if (i >= envsize - 1) {
837 fatal("child_set_env: too many env vars");
839 env = (*envp) = xrealloc(env, envsize * sizeof(char *));
842 /* Need to set the NULL pointer at end of array beyond the new slot. */
846 /* Allocate space and format the variable in the appropriate slot. */
847 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
848 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
852 * Reads environment variables from the given file and adds/overrides them
853 * into the environment. If the file does not exist, this does nothing.
854 * Otherwise, it must consist of empty lines, comments (line starts with '#')
855 * and assignments of the form name=value. No other forms are allowed.
858 read_environment_file(char ***env, u_int *envsize,
859 const char *filename)
866 f = fopen(filename, "r");
870 while (fgets(buf, sizeof(buf), f)) {
872 fatal("Too many lines in environment file %s", filename);
873 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
875 if (!*cp || *cp == '#' || *cp == '\n')
877 if (strchr(cp, '\n'))
878 *strchr(cp, '\n') = '\0';
879 value = strchr(cp, '=');
881 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
886 * Replace the equals sign by nul, and advance value to
891 child_set_env(env, envsize, cp, value);
896 #ifdef HAVE_ETC_DEFAULT_LOGIN
898 * Return named variable from specified environment, or NULL if not present.
901 child_get_env(char **env, const char *name)
907 for (i=0; env[i] != NULL; i++)
908 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
909 return(env[i] + len + 1);
914 * Read /etc/default/login.
915 * We pick up the PATH (or SUPATH for root) and UMASK.
918 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
920 char **tmpenv = NULL, *var;
921 u_int i, tmpenvsize = 0;
925 * We don't want to copy the whole file to the child's environment,
926 * so we use a temporary environment and copy the variables we're
929 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
935 var = child_get_env(tmpenv, "SUPATH");
937 var = child_get_env(tmpenv, "PATH");
939 child_set_env(env, envsize, "PATH", var);
941 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
942 if (sscanf(var, "%5lo", &mask) == 1)
945 for (i = 0; tmpenv[i] != NULL; i++)
949 #endif /* HAVE_ETC_DEFAULT_LOGIN */
952 copy_environment(char **source, char ***env, u_int *envsize)
954 char *var_name, *var_val;
960 for(i = 0; source[i] != NULL; i++) {
961 var_name = xstrdup(source[i]);
962 if ((var_val = strstr(var_name, "=")) == NULL) {
968 debug3("Copy environment: %s=%s", var_name, var_val);
969 child_set_env(env, envsize, var_name, var_val);
976 do_setup_env(Session *s, const char *shell)
980 char **env, *laddr, *path = NULL;
981 struct passwd *pw = s->pw;
983 /* Initialize the environment. */
985 env = xmalloc(envsize * sizeof(char *));
990 * The Windows environment contains some setting which are
991 * important for a running system. They must not be dropped.
996 p = fetch_windows_environment();
997 copy_environment(p, &env, &envsize);
998 free_windows_environment(p);
1003 /* Allow any GSSAPI methods that we've used to alter
1004 * the childs environment as they see fit
1006 ssh_gssapi_do_child(&env, &envsize);
1009 if (!options.use_login) {
1010 /* Set basic environment. */
1011 for (i = 0; i < s->num_env; i++)
1012 child_set_env(&env, &envsize, s->env[i].name,
1015 child_set_env(&env, &envsize, "USER", pw->pw_name);
1016 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1018 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1020 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1021 #ifdef HAVE_LOGIN_CAP
1022 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1023 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1025 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1026 #else /* HAVE_LOGIN_CAP */
1027 # ifndef HAVE_CYGWIN
1029 * There's no standard path on Windows. The path contains
1030 * important components pointing to the system directories,
1031 * needed for loading shared libraries. So the path better
1032 * remains intact here.
1034 # ifdef HAVE_ETC_DEFAULT_LOGIN
1035 read_etc_default_login(&env, &envsize, pw->pw_uid);
1036 path = child_get_env(env, "PATH");
1037 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1038 if (path == NULL || *path == '\0') {
1039 child_set_env(&env, &envsize, "PATH",
1040 s->pw->pw_uid == 0 ?
1041 SUPERUSER_PATH : _PATH_STDPATH);
1043 # endif /* HAVE_CYGWIN */
1044 #endif /* HAVE_LOGIN_CAP */
1046 snprintf(buf, sizeof buf, "%.200s/%.50s",
1047 _PATH_MAILDIR, pw->pw_name);
1048 child_set_env(&env, &envsize, "MAIL", buf);
1050 /* Normal systems set SHELL by default. */
1051 child_set_env(&env, &envsize, "SHELL", shell);
1054 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1056 /* Set custom environment options from RSA authentication. */
1057 if (!options.use_login) {
1058 while (custom_environment) {
1059 struct envstring *ce = custom_environment;
1062 for (i = 0; str[i] != '=' && str[i]; i++)
1064 if (str[i] == '=') {
1066 child_set_env(&env, &envsize, str, str + i + 1);
1068 custom_environment = ce->next;
1074 /* SSH_CLIENT deprecated */
1075 snprintf(buf, sizeof buf, "%.50s %d %d",
1076 get_remote_ipaddr(), get_remote_port(), get_local_port());
1077 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1079 laddr = get_local_ipaddr(packet_get_connection_in());
1080 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1081 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1083 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1086 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1088 child_set_env(&env, &envsize, "TERM", s->term);
1090 child_set_env(&env, &envsize, "DISPLAY", s->display);
1091 if (original_command)
1092 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1096 if (cray_tmpdir[0] != '\0')
1097 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1098 #endif /* _UNICOS */
1101 * Since we clear KRB5CCNAME at startup, if it's set now then it
1102 * must have been set by a native authentication method (eg AIX or
1103 * SIA), so copy it to the child.
1108 if ((cp = getenv("KRB5CCNAME")) != NULL)
1109 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1116 if ((cp = getenv("AUTHSTATE")) != NULL)
1117 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1118 read_environment_file(&env, &envsize, "/etc/environment");
1122 if (s->authctxt->krb5_ccname)
1123 child_set_env(&env, &envsize, "KRB5CCNAME",
1124 s->authctxt->krb5_ccname);
1128 * Pull in any environment variables that may have
1131 if (options.use_pam) {
1134 p = fetch_pam_child_environment();
1135 copy_environment(p, &env, &envsize);
1136 free_pam_environment(p);
1138 p = fetch_pam_environment();
1139 copy_environment(p, &env, &envsize);
1140 free_pam_environment(p);
1142 #endif /* USE_PAM */
1144 if (auth_sock_name != NULL)
1145 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1148 /* read $HOME/.ssh/environment. */
1149 if (options.permit_user_env && !options.use_login) {
1150 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1151 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1152 read_environment_file(&env, &envsize, buf);
1155 /* dump the environment */
1156 fprintf(stderr, "Environment:\n");
1157 for (i = 0; env[i]; i++)
1158 fprintf(stderr, " %.200s\n", env[i]);
1164 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1165 * first in this order).
1168 do_rc_files(Session *s, const char *shell)
1176 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1178 /* ignore _PATH_SSH_USER_RC for subsystems */
1179 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1180 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1181 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1183 fprintf(stderr, "Running %s\n", cmd);
1184 f = popen(cmd, "w");
1187 fprintf(f, "%s %s\n", s->auth_proto,
1191 fprintf(stderr, "Could not run %s\n",
1193 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1195 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1196 _PATH_SSH_SYSTEM_RC);
1197 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1200 fprintf(f, "%s %s\n", s->auth_proto,
1204 fprintf(stderr, "Could not run %s\n",
1205 _PATH_SSH_SYSTEM_RC);
1206 } else if (do_xauth && options.xauth_location != NULL) {
1207 /* Add authority data to .Xauthority if appropriate. */
1210 "Running %.500s remove %.100s\n",
1211 options.xauth_location, s->auth_display);
1213 "%.500s add %.100s %.100s %.100s\n",
1214 options.xauth_location, s->auth_display,
1215 s->auth_proto, s->auth_data);
1217 snprintf(cmd, sizeof cmd, "%s -q -",
1218 options.xauth_location);
1219 f = popen(cmd, "w");
1221 fprintf(f, "remove %s\n",
1223 fprintf(f, "add %s %s %s\n",
1224 s->auth_display, s->auth_proto,
1228 fprintf(stderr, "Could not run %s\n",
1235 do_nologin(struct passwd *pw)
1240 #ifdef HAVE_LOGIN_CAP
1241 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1242 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1243 _PATH_NOLOGIN), "r");
1246 f = fopen(_PATH_NOLOGIN, "r");
1249 /* /etc/nologin exists. Print its contents and exit. */
1250 logit("User %.100s not allowed because %s exists",
1251 pw->pw_name, _PATH_NOLOGIN);
1252 while (fgets(buf, sizeof(buf), f))
1260 /* Set login name, uid, gid, and groups. */
1262 do_setusercontext(struct passwd *pw)
1265 if (getuid() == 0 || geteuid() == 0)
1266 #endif /* HAVE_CYGWIN */
1269 #ifdef HAVE_SETPCRED
1270 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1271 fatal("Failed to set process credentials");
1272 #endif /* HAVE_SETPCRED */
1273 #ifdef HAVE_LOGIN_CAP
1278 if (options.gss_authentication) {
1279 temporarily_use_uid(pw);
1280 ssh_gssapi_storecreds();
1285 if (options.use_pam) {
1289 # endif /* USE_PAM */
1290 if (setusercontext(lc, pw, pw->pw_uid,
1291 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1292 perror("unable to set user context");
1296 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1297 /* Sets login uid for accounting */
1298 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1299 error("setluid: %s", strerror(errno));
1300 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1302 if (setlogin(pw->pw_name) < 0)
1303 error("setlogin failed: %s", strerror(errno));
1304 if (setgid(pw->pw_gid) < 0) {
1308 /* Initialize the group list. */
1309 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1310 perror("initgroups");
1315 if (options.gss_authentication) {
1316 temporarily_use_uid(pw);
1317 ssh_gssapi_storecreds();
1323 * PAM credentials may take the form of supplementary groups.
1324 * These will have been wiped by the above initgroups() call.
1325 * Reestablish them here.
1327 if (options.use_pam) {
1331 # endif /* USE_PAM */
1332 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1333 irix_setusercontext(pw);
1334 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1338 #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
1339 if (set_id(pw->pw_name) != 0) {
1342 #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
1343 /* Permanently switch to the desired uid. */
1344 permanently_set_uid(pw);
1351 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1352 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1356 do_pwchange(Session *s)
1359 fprintf(stderr, "WARNING: Your password has expired.\n");
1360 if (s->ttyfd != -1) {
1362 "You must change your password now and login again!\n");
1363 #ifdef PASSWD_NEEDS_USERNAME
1364 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1367 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1372 "Password change required but no TTY available.\n");
1378 launch_login(struct passwd *pw, const char *hostname)
1380 /* Launch login(1). */
1382 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1383 #ifdef xxxLOGIN_NEEDS_TERM
1384 (s->term ? s->term : "unknown"),
1385 #endif /* LOGIN_NEEDS_TERM */
1386 #ifdef LOGIN_NO_ENDOPT
1387 "-p", "-f", pw->pw_name, (char *)NULL);
1389 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1392 /* Login couldn't be executed, die. */
1399 child_close_fds(void)
1403 if (packet_get_connection_in() == packet_get_connection_out())
1404 close(packet_get_connection_in());
1406 close(packet_get_connection_in());
1407 close(packet_get_connection_out());
1410 * Close all descriptors related to channels. They will still remain
1411 * open in the parent.
1413 /* XXX better use close-on-exec? -markus */
1414 channel_close_all();
1417 * Close any extra file descriptors. Note that there may still be
1418 * descriptors left by system functions. They will be closed later.
1423 * Close any extra open file descriptors so that we don't have them
1424 * hanging around in clients. Note that we want to do this after
1425 * initgroups, because at least on Solaris 2.3 it leaves file
1428 for (i = 3; i < 64; i++)
1433 * Performs common processing for the child, such as setting up the
1434 * environment, closing extra file descriptors, setting the user and group
1435 * ids, and executing the command or shell.
1438 do_child(Session *s, const char *command)
1440 extern char **environ;
1443 const char *shell, *shell0, *hostname = NULL;
1444 struct passwd *pw = s->pw;
1446 /* remove hostkey from the child's memory */
1447 destroy_sensitive_data();
1449 /* Force a password change */
1450 if (s->authctxt->force_pwchange) {
1451 do_setusercontext(pw);
1457 /* login(1) is only called if we execute the login shell */
1458 if (options.use_login && command != NULL)
1459 options.use_login = 0;
1462 cray_setup(pw->pw_uid, pw->pw_name, command);
1463 #endif /* _UNICOS */
1466 * Login(1) does this as well, and it needs uid 0 for the "-h"
1467 * switch, so we let login(1) to this for us.
1469 if (!options.use_login) {
1471 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1472 if (!check_quietlogin(s, command))
1474 #else /* HAVE_OSF_SIA */
1475 /* When PAM is enabled we rely on it to do the nologin check */
1476 if (!options.use_pam)
1478 do_setusercontext(pw);
1480 * PAM session modules in do_setusercontext may have
1481 * generated messages, so if this in an interactive
1482 * login then display them too.
1484 if (!check_quietlogin(s, command))
1486 #endif /* HAVE_OSF_SIA */
1490 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1491 debug3("PAM session not opened, exiting");
1498 * Get the shell from the password data. An empty shell field is
1499 * legal, and means /bin/sh.
1501 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1504 * Make sure $SHELL points to the shell from the password file,
1505 * even if shell is overridden from login.conf
1507 env = do_setup_env(s, shell);
1509 #ifdef HAVE_LOGIN_CAP
1510 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1513 /* we have to stash the hostname before we close our socket. */
1514 if (options.use_login)
1515 hostname = get_remote_name_or_ip(utmp_len,
1518 * Close the connection descriptors; note that this is the child, and
1519 * the server will still have the socket open, and it is important
1520 * that we do not shutdown it. Note that the descriptors cannot be
1521 * closed before building the environment, as we call
1522 * get_remote_ipaddr there.
1527 * Must take new environment into use so that .ssh/rc,
1528 * /etc/ssh/sshrc and xauth are run in the proper environment.
1532 #if defined(KRB5) && defined(USE_AFS)
1534 * At this point, we check to see if AFS is active and if we have
1535 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1536 * if we can (and need to) extend the ticket into an AFS token. If
1537 * we don't do this, we run into potential problems if the user's
1538 * home directory is in AFS and it's not world-readable.
1541 if (options.kerberos_get_afs_token && k_hasafs() &&
1542 (s->authctxt->krb5_ctx != NULL)) {
1545 debug("Getting AFS token");
1549 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1550 krb5_afslog(s->authctxt->krb5_ctx,
1551 s->authctxt->krb5_fwd_ccache, cell, NULL);
1553 krb5_afslog_home(s->authctxt->krb5_ctx,
1554 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1558 /* Change current directory to the user's home directory. */
1559 if (chdir(pw->pw_dir) < 0) {
1560 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1561 pw->pw_dir, strerror(errno));
1562 #ifdef HAVE_LOGIN_CAP
1563 if (login_getcapbool(lc, "requirehome", 0))
1568 if (!options.use_login)
1569 do_rc_files(s, shell);
1571 /* restore SIGPIPE for child */
1572 signal(SIGPIPE, SIG_DFL);
1574 if (options.use_login) {
1575 launch_login(pw, hostname);
1579 /* Get the last component of the shell name. */
1580 if ((shell0 = strrchr(shell, '/')) != NULL)
1586 * If we have no command, execute the shell. In this case, the shell
1587 * name to be passed in argv[0] is preceded by '-' to indicate that
1588 * this is a login shell.
1593 /* Start the shell. Set initial character to '-'. */
1596 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1597 >= sizeof(argv0) - 1) {
1603 /* Execute the shell. */
1606 execve(shell, argv, env);
1608 /* Executing the shell failed. */
1613 * Execute the command using the user's shell. This uses the -c
1614 * option to execute the command.
1616 argv[0] = (char *) shell0;
1618 argv[2] = (char *) command;
1620 execve(shell, argv, env);
1629 static int did_init = 0;
1631 debug("session_new: init");
1632 for (i = 0; i < MAX_SESSIONS; i++) {
1633 sessions[i].used = 0;
1637 for (i = 0; i < MAX_SESSIONS; i++) {
1638 Session *s = &sessions[i];
1640 memset(s, 0, sizeof(*s));
1646 s->x11_chanids = NULL;
1647 debug("session_new: session %d", i);
1658 for (i = 0; i < MAX_SESSIONS; i++) {
1659 Session *s = &sessions[i];
1660 debug("dump: used %d session %d %p channel %d pid %ld",
1670 session_open(Authctxt *authctxt, int chanid)
1672 Session *s = session_new();
1673 debug("session_open: channel %d", chanid);
1675 error("no more sessions");
1678 s->authctxt = authctxt;
1679 s->pw = authctxt->pw;
1680 if (s->pw == NULL || !authctxt->valid)
1681 fatal("no user for session %d", s->self);
1682 debug("session_open: session %d: link with channel %d", s->self, chanid);
1688 session_by_tty(char *tty)
1691 for (i = 0; i < MAX_SESSIONS; i++) {
1692 Session *s = &sessions[i];
1693 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1694 debug("session_by_tty: session %d tty %s", i, tty);
1698 debug("session_by_tty: unknown tty %.100s", tty);
1704 session_by_channel(int id)
1707 for (i = 0; i < MAX_SESSIONS; i++) {
1708 Session *s = &sessions[i];
1709 if (s->used && s->chanid == id) {
1710 debug("session_by_channel: session %d channel %d", i, id);
1714 debug("session_by_channel: unknown channel %d", id);
1720 session_by_x11_channel(int id)
1724 for (i = 0; i < MAX_SESSIONS; i++) {
1725 Session *s = &sessions[i];
1727 if (s->x11_chanids == NULL || !s->used)
1729 for (j = 0; s->x11_chanids[j] != -1; j++) {
1730 if (s->x11_chanids[j] == id) {
1731 debug("session_by_x11_channel: session %d "
1732 "channel %d", s->self, id);
1737 debug("session_by_x11_channel: unknown channel %d", id);
1743 session_by_pid(pid_t pid)
1746 debug("session_by_pid: pid %ld", (long)pid);
1747 for (i = 0; i < MAX_SESSIONS; i++) {
1748 Session *s = &sessions[i];
1749 if (s->used && s->pid == pid)
1752 error("session_by_pid: unknown pid %ld", (long)pid);
1758 session_window_change_req(Session *s)
1760 s->col = packet_get_int();
1761 s->row = packet_get_int();
1762 s->xpixel = packet_get_int();
1763 s->ypixel = packet_get_int();
1765 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1770 session_pty_req(Session *s)
1776 debug("Allocating a pty not permitted for this authentication.");
1779 if (s->ttyfd != -1) {
1780 packet_disconnect("Protocol error: you already have a pty.");
1784 s->term = packet_get_string(&len);
1787 s->col = packet_get_int();
1788 s->row = packet_get_int();
1790 s->row = packet_get_int();
1791 s->col = packet_get_int();
1793 s->xpixel = packet_get_int();
1794 s->ypixel = packet_get_int();
1796 if (strcmp(s->term, "") == 0) {
1801 /* Allocate a pty and open it. */
1802 debug("Allocating pty.");
1803 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1809 error("session_pty_req: session %d alloc failed", s->self);
1812 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1814 /* for SSH1 the tty modes length is not given */
1816 n_bytes = packet_remaining();
1817 tty_parse_modes(s->ttyfd, &n_bytes);
1820 pty_setowner(s->pw, s->tty);
1822 /* Set window size from the packet. */
1823 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1826 session_proctitle(s);
1831 session_subsystem_req(Session *s)
1836 char *cmd, *subsys = packet_get_string(&len);
1840 logit("subsystem request for %.100s", subsys);
1842 for (i = 0; i < options.num_subsystems; i++) {
1843 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1844 cmd = options.subsystem_command[i];
1845 if (stat(cmd, &st) < 0) {
1846 error("subsystem: cannot stat %s: %s", cmd,
1850 debug("subsystem: exec() %s", cmd);
1851 s->is_subsystem = 1;
1859 logit("subsystem request for %.100s failed, subsystem not found",
1867 session_x11_req(Session *s)
1871 if (s->auth_proto != NULL || s->auth_data != NULL) {
1872 error("session_x11_req: session %d: "
1873 "x11 forwarding already active", s->self);
1876 s->single_connection = packet_get_char();
1877 s->auth_proto = packet_get_string(NULL);
1878 s->auth_data = packet_get_string(NULL);
1879 s->screen = packet_get_int();
1882 success = session_setup_x11fwd(s);
1884 xfree(s->auth_proto);
1885 xfree(s->auth_data);
1886 s->auth_proto = NULL;
1887 s->auth_data = NULL;
1893 session_shell_req(Session *s)
1901 session_exec_req(Session *s)
1904 char *command = packet_get_string(&len);
1906 do_exec(s, command);
1912 session_break_req(Session *s)
1915 packet_get_int(); /* ignored */
1918 if (s->ttyfd == -1 ||
1919 tcsendbreak(s->ttyfd, 0) < 0)
1925 session_env_req(Session *s)
1928 u_int name_len, val_len, i;
1930 name = packet_get_string(&name_len);
1931 val = packet_get_string(&val_len);
1934 /* Don't set too many environment variables */
1935 if (s->num_env > 128) {
1936 debug2("Ignoring env request %s: too many env vars", name);
1940 for (i = 0; i < options.num_accept_env; i++) {
1941 if (match_pattern(name, options.accept_env[i])) {
1942 debug2("Setting env %d: %s=%s", s->num_env, name, val);
1943 s->env = xrealloc(s->env, sizeof(*s->env) *
1945 s->env[s->num_env].name = name;
1946 s->env[s->num_env].val = val;
1951 debug2("Ignoring env request %s: disallowed name", name);
1960 session_auth_agent_req(Session *s)
1962 static int called = 0;
1964 if (no_agent_forwarding_flag) {
1965 debug("session_auth_agent_req: no_agent_forwarding_flag");
1972 return auth_input_request_forwarding(s->pw);
1977 session_input_channel_req(Channel *c, const char *rtype)
1982 if ((s = session_by_channel(c->self)) == NULL) {
1983 logit("session_input_channel_req: no session %d req %.100s",
1987 debug("session_input_channel_req: session %d req %s", s->self, rtype);
1990 * a session is in LARVAL state until a shell, a command
1991 * or a subsystem is executed
1993 if (c->type == SSH_CHANNEL_LARVAL) {
1994 if (strcmp(rtype, "shell") == 0) {
1995 success = session_shell_req(s);
1996 } else if (strcmp(rtype, "exec") == 0) {
1997 success = session_exec_req(s);
1998 } else if (strcmp(rtype, "pty-req") == 0) {
1999 success = session_pty_req(s);
2000 } else if (strcmp(rtype, "x11-req") == 0) {
2001 success = session_x11_req(s);
2002 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2003 success = session_auth_agent_req(s);
2004 } else if (strcmp(rtype, "subsystem") == 0) {
2005 success = session_subsystem_req(s);
2006 } else if (strcmp(rtype, "env") == 0) {
2007 success = session_env_req(s);
2010 if (strcmp(rtype, "window-change") == 0) {
2011 success = session_window_change_req(s);
2012 } else if (strcmp(rtype, "break") == 0) {
2013 success = session_break_req(s);
2020 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2023 fatal("session_set_fds: called for proto != 2.0");
2025 * now that have a child and a pipe to the child,
2026 * we can activate our channel and register the fd's
2028 if (s->chanid == -1)
2029 fatal("no channel for session %d", s->self);
2030 channel_set_fds(s->chanid,
2032 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2034 CHAN_SES_WINDOW_DEFAULT);
2038 * Function to perform pty cleanup. Also called if we get aborted abnormally
2039 * (e.g., due to a dropped connection).
2042 session_pty_cleanup2(Session *s)
2045 error("session_pty_cleanup: no session");
2051 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2053 /* Record that the user has logged out. */
2055 record_logout(s->pid, s->tty, s->pw->pw_name);
2057 /* Release the pseudo-tty. */
2059 pty_release(s->tty);
2062 * Close the server side of the socket pairs. We must do this after
2063 * the pty cleanup, so that another process doesn't get this pty
2064 * while we're still cleaning up.
2066 if (close(s->ptymaster) < 0)
2067 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2069 /* unlink pty from session */
2074 session_pty_cleanup(Session *s)
2076 PRIVSEP(session_pty_cleanup2(s));
2082 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2097 return "SIG@openssh.com";
2101 session_close_x11(int id)
2105 if ((c = channel_by_id(id)) == NULL) {
2106 debug("session_close_x11: x11 channel %d missing", id);
2108 /* Detach X11 listener */
2109 debug("session_close_x11: detach x11 channel %d", id);
2110 channel_cancel_cleanup(id);
2111 if (c->ostate != CHAN_OUTPUT_CLOSED)
2117 session_close_single_x11(int id, void *arg)
2122 debug3("session_close_single_x11: channel %d", id);
2123 channel_cancel_cleanup(id);
2124 if ((s = session_by_x11_channel(id)) == NULL)
2125 fatal("session_close_single_x11: no x11 channel %d", id);
2126 for (i = 0; s->x11_chanids[i] != -1; i++) {
2127 debug("session_close_single_x11: session %d: "
2128 "closing channel %d", s->self, s->x11_chanids[i]);
2130 * The channel "id" is already closing, but make sure we
2131 * close all of its siblings.
2133 if (s->x11_chanids[i] != id)
2134 session_close_x11(s->x11_chanids[i]);
2136 xfree(s->x11_chanids);
2137 s->x11_chanids = NULL;
2142 if (s->auth_proto) {
2143 xfree(s->auth_proto);
2144 s->auth_proto = NULL;
2147 xfree(s->auth_data);
2148 s->auth_data = NULL;
2150 if (s->auth_display) {
2151 xfree(s->auth_display);
2152 s->auth_display = NULL;
2157 session_exit_message(Session *s, int status)
2161 if ((c = channel_lookup(s->chanid)) == NULL)
2162 fatal("session_exit_message: session %d: no channel %d",
2163 s->self, s->chanid);
2164 debug("session_exit_message: session %d channel %d pid %ld",
2165 s->self, s->chanid, (long)s->pid);
2167 if (WIFEXITED(status)) {
2168 channel_request_start(s->chanid, "exit-status", 0);
2169 packet_put_int(WEXITSTATUS(status));
2171 } else if (WIFSIGNALED(status)) {
2172 channel_request_start(s->chanid, "exit-signal", 0);
2173 packet_put_cstring(sig2name(WTERMSIG(status)));
2175 packet_put_char(WCOREDUMP(status));
2176 #else /* WCOREDUMP */
2178 #endif /* WCOREDUMP */
2179 packet_put_cstring("");
2180 packet_put_cstring("");
2183 /* Some weird exit cause. Just exit. */
2184 packet_disconnect("wait returned status %04x.", status);
2187 /* disconnect channel */
2188 debug("session_exit_message: release channel %d", s->chanid);
2191 * Adjust cleanup callback attachment to send close messages when
2192 * the channel gets EOF. The session will be then be closed
2193 * by session_close_by_channel when the childs close their fds.
2195 channel_register_cleanup(c->self, session_close_by_channel, 1);
2198 * emulate a write failure with 'chan_write_failed', nobody will be
2199 * interested in data we write.
2200 * Note that we must not call 'chan_read_failed', since there could
2201 * be some more data waiting in the pipe.
2203 if (c->ostate != CHAN_OUTPUT_CLOSED)
2204 chan_write_failed(c);
2208 session_close(Session *s)
2212 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2214 session_pty_cleanup(s);
2220 xfree(s->x11_chanids);
2221 if (s->auth_display)
2222 xfree(s->auth_display);
2224 xfree(s->auth_data);
2226 xfree(s->auth_proto);
2228 for (i = 0; i < s->num_env; i++) {
2229 xfree(s->env[i].name);
2230 xfree(s->env[i].val);
2234 session_proctitle(s);
2238 session_close_by_pid(pid_t pid, int status)
2240 Session *s = session_by_pid(pid);
2242 debug("session_close_by_pid: no session for pid %ld",
2246 if (s->chanid != -1)
2247 session_exit_message(s, status);
2249 session_pty_cleanup(s);
2254 * this is called when a channel dies before
2255 * the session 'child' itself dies
2258 session_close_by_channel(int id, void *arg)
2260 Session *s = session_by_channel(id);
2264 debug("session_close_by_channel: no session for id %d", id);
2267 debug("session_close_by_channel: channel %d child %ld",
2270 debug("session_close_by_channel: channel %d: has child", id);
2272 * delay detach of session, but release pty, since
2273 * the fd's to the child are already closed
2276 session_pty_cleanup(s);
2279 /* detach by removing callback */
2280 channel_cancel_cleanup(s->chanid);
2282 /* Close any X11 listeners associated with this session */
2283 if (s->x11_chanids != NULL) {
2284 for (i = 0; s->x11_chanids[i] != -1; i++) {
2285 session_close_x11(s->x11_chanids[i]);
2286 s->x11_chanids[i] = -1;
2295 session_destroy_all(void (*closefunc)(Session *))
2298 for (i = 0; i < MAX_SESSIONS; i++) {
2299 Session *s = &sessions[i];
2301 if (closefunc != NULL)
2310 session_tty_list(void)
2312 static char buf[1024];
2317 for (i = 0; i < MAX_SESSIONS; i++) {
2318 Session *s = &sessions[i];
2319 if (s->used && s->ttyfd != -1) {
2321 if (strncmp(s->tty, "/dev/", 5) != 0) {
2322 cp = strrchr(s->tty, '/');
2323 cp = (cp == NULL) ? s->tty : cp + 1;
2328 strlcat(buf, ",", sizeof buf);
2329 strlcat(buf, cp, sizeof buf);
2333 strlcpy(buf, "notty", sizeof buf);
2338 session_proctitle(Session *s)
2341 error("no user for session %d", s->self);
2343 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2347 session_setup_x11fwd(Session *s)
2350 char display[512], auth_display[512];
2351 char hostname[MAXHOSTNAMELEN];
2354 if (no_x11_forwarding_flag) {
2355 packet_send_debug("X11 forwarding disabled in user configuration file.");
2358 if (!options.x11_forwarding) {
2359 debug("X11 forwarding disabled in server configuration file.");
2362 if (!options.xauth_location ||
2363 (stat(options.xauth_location, &st) == -1)) {
2364 packet_send_debug("No xauth program; cannot forward with spoofing.");
2367 if (options.use_login) {
2368 packet_send_debug("X11 forwarding disabled; "
2369 "not compatible with UseLogin=yes.");
2372 if (s->display != NULL) {
2373 debug("X11 display already set.");
2376 if (x11_create_display_inet(options.x11_display_offset,
2377 options.x11_use_localhost, s->single_connection,
2378 &s->display_number, &s->x11_chanids) == -1) {
2379 debug("x11_create_display_inet failed.");
2382 for (i = 0; s->x11_chanids[i] != -1; i++) {
2383 channel_register_cleanup(s->x11_chanids[i],
2384 session_close_single_x11, 0);
2387 /* Set up a suitable value for the DISPLAY variable. */
2388 if (gethostname(hostname, sizeof(hostname)) < 0)
2389 fatal("gethostname: %.100s", strerror(errno));
2391 * auth_display must be used as the displayname when the
2392 * authorization entry is added with xauth(1). This will be
2393 * different than the DISPLAY string for localhost displays.
2395 if (options.x11_use_localhost) {
2396 snprintf(display, sizeof display, "localhost:%u.%u",
2397 s->display_number, s->screen);
2398 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2399 s->display_number, s->screen);
2400 s->display = xstrdup(display);
2401 s->auth_display = xstrdup(auth_display);
2403 #ifdef IPADDR_IN_DISPLAY
2405 struct in_addr my_addr;
2407 he = gethostbyname(hostname);
2409 error("Can't get IP address for X11 DISPLAY.");
2410 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2413 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2414 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2415 s->display_number, s->screen);
2417 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2418 s->display_number, s->screen);
2420 s->display = xstrdup(display);
2421 s->auth_display = xstrdup(display);
2428 do_authenticated2(Authctxt *authctxt)
2430 server_loop2(authctxt);
2434 do_cleanup(Authctxt *authctxt)
2436 static int called = 0;
2438 debug("do_cleanup");
2440 /* no cleanup if we're in the child for login shell */
2444 /* avoid double cleanup */
2449 if (authctxt == NULL)
2452 if (options.kerberos_ticket_cleanup &&
2454 krb5_cleanup_proc(authctxt);
2458 if (compat20 && options.gss_cleanup_creds)
2459 ssh_gssapi_cleanup_creds();
2463 if (options.use_pam) {
2465 sshpam_thread_cleanup();
2469 /* remove agent socket */
2470 auth_sock_cleanup_proc(authctxt->pw);
2473 * Cleanup ptys/utmp only if privsep is disabled,
2474 * or if running in monitor.
2476 if (!use_privsep || mm_is_monitor())
2477 session_destroy_all(session_pty_cleanup2);