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 1.191 2005/12/24 02:27:41 djm Exp $");
51 #include "auth-options.h"
52 #include "pathnames.h"
56 #include "serverloop.h"
60 #include "monitor_wrap.h"
62 #if defined(KRB5) && defined(USE_AFS)
72 Session *session_new(void);
73 void session_set_fds(Session *, int, int, int);
74 void session_pty_cleanup(Session *);
75 void session_proctitle(Session *);
76 int session_setup_x11fwd(Session *);
77 void do_exec_pty(Session *, const char *);
78 void do_exec_no_pty(Session *, const char *);
79 void do_exec(Session *, const char *);
80 void do_login(Session *, const char *);
81 #ifdef LOGIN_NEEDS_UTMPX
82 static void do_pre_login(Session *s);
84 void do_child(Session *, const char *);
86 int check_quietlogin(Session *, const char *);
88 static void do_authenticated1(Authctxt *);
89 static void do_authenticated2(Authctxt *);
91 static int session_pty_req(Session *);
94 extern ServerOptions options;
95 extern char *__progname;
96 extern int log_stderr;
97 extern int debug_flag;
98 extern u_int utmp_len;
99 extern int startup_pipe;
100 extern void destroy_sensitive_data(void);
101 extern Buffer loginmsg;
103 /* original command from peer. */
104 const char *original_command = NULL;
107 #define MAX_SESSIONS 10
108 Session sessions[MAX_SESSIONS];
110 #ifdef HAVE_LOGIN_CAP
114 static int is_child = 0;
116 /* Name and directory of socket for authentication agent forwarding. */
117 static char *auth_sock_name = NULL;
118 static char *auth_sock_dir = NULL;
120 /* removes the agent forwarding socket */
123 auth_sock_cleanup_proc(struct passwd *pw)
125 if (auth_sock_name != NULL) {
126 temporarily_use_uid(pw);
127 unlink(auth_sock_name);
128 rmdir(auth_sock_dir);
129 auth_sock_name = NULL;
135 auth_input_request_forwarding(struct passwd * pw)
139 struct sockaddr_un sunaddr;
141 if (auth_sock_name != NULL) {
142 error("authentication forwarding requested twice.");
146 /* Temporarily drop privileged uid for mkdir/bind. */
147 temporarily_use_uid(pw);
149 /* Allocate a buffer for the socket name, and format the name. */
150 auth_sock_name = xmalloc(MAXPATHLEN);
151 auth_sock_dir = xmalloc(MAXPATHLEN);
152 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
154 /* Create private directory for socket */
155 if (mkdtemp(auth_sock_dir) == NULL) {
156 packet_send_debug("Agent forwarding disabled: "
157 "mkdtemp() failed: %.100s", strerror(errno));
159 xfree(auth_sock_name);
160 xfree(auth_sock_dir);
161 auth_sock_name = NULL;
162 auth_sock_dir = NULL;
165 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
166 auth_sock_dir, (long) getpid());
168 /* Create the socket. */
169 sock = socket(AF_UNIX, SOCK_STREAM, 0);
171 packet_disconnect("socket: %.100s", strerror(errno));
173 /* Bind it to the name. */
174 memset(&sunaddr, 0, sizeof(sunaddr));
175 sunaddr.sun_family = AF_UNIX;
176 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
178 if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
179 packet_disconnect("bind: %.100s", strerror(errno));
181 /* Restore the privileged uid. */
184 /* Start listening on the socket. */
185 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
186 packet_disconnect("listen: %.100s", strerror(errno));
188 /* Allocate a channel for the authentication agent socket. */
189 /* this shouldn't matter if its hpn or not - cjr */
190 nc = channel_new("auth socket",
191 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
192 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
193 0, "auth socket", 1);
194 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
199 display_loginmsg(void)
201 if (buffer_len(&loginmsg) > 0) {
202 buffer_append(&loginmsg, "\0", 1);
203 printf("%s", (char *)buffer_ptr(&loginmsg));
204 buffer_clear(&loginmsg);
209 do_authenticated(Authctxt *authctxt)
211 setproctitle("%s", authctxt->pw->pw_name);
213 /* setup the channel layer */
214 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
215 channel_permit_all_opens();
218 do_authenticated2(authctxt);
220 do_authenticated1(authctxt);
222 do_cleanup(authctxt);
226 * Prepares for an interactive session. This is called after the user has
227 * been successfully authenticated. During this message exchange, pseudo
228 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
229 * are requested, etc.
232 do_authenticated1(Authctxt *authctxt)
236 int success, type, screen_flag;
237 int enable_compression_after_reply = 0;
238 u_int proto_len, data_len, dlen, compression_level = 0;
242 error("no more sessions");
245 s->authctxt = authctxt;
246 s->pw = authctxt->pw;
249 * We stay in this loop until the client requests to execute a shell
255 /* Get a packet from the client. */
256 type = packet_read();
258 /* Process the packet. */
260 case SSH_CMSG_REQUEST_COMPRESSION:
261 compression_level = packet_get_int();
263 if (compression_level < 1 || compression_level > 9) {
264 packet_send_debug("Received invalid compression level %d.",
268 if (options.compression == COMP_NONE) {
269 debug2("compression disabled");
272 /* Enable compression after we have responded with SUCCESS. */
273 enable_compression_after_reply = 1;
277 case SSH_CMSG_REQUEST_PTY:
278 success = session_pty_req(s);
281 case SSH_CMSG_X11_REQUEST_FORWARDING:
282 s->auth_proto = packet_get_string(&proto_len);
283 s->auth_data = packet_get_string(&data_len);
285 screen_flag = packet_get_protocol_flags() &
286 SSH_PROTOFLAG_SCREEN_NUMBER;
287 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
289 if (packet_remaining() == 4) {
291 debug2("Buggy client: "
292 "X11 screen flag missing");
293 s->screen = packet_get_int();
298 success = session_setup_x11fwd(s);
300 xfree(s->auth_proto);
302 s->auth_proto = NULL;
307 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
308 if (no_agent_forwarding_flag || compat13) {
309 debug("Authentication agent forwarding not permitted for this authentication.");
312 debug("Received authentication agent forwarding request.");
313 success = auth_input_request_forwarding(s->pw);
316 case SSH_CMSG_PORT_FORWARD_REQUEST:
317 if (no_port_forwarding_flag) {
318 debug("Port forwarding not permitted for this authentication.");
321 if (!options.allow_tcp_forwarding) {
322 debug("Port forwarding not permitted.");
325 debug("Received TCP/IP port forwarding request.");
326 channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports,
327 options.hpn_disabled,
328 options.hpn_buffer_size);
332 case SSH_CMSG_MAX_PACKET_SIZE:
333 if (packet_set_maxsize(packet_get_int()) > 0)
337 case SSH_CMSG_EXEC_SHELL:
338 case SSH_CMSG_EXEC_CMD:
339 if (type == SSH_CMSG_EXEC_CMD) {
340 command = packet_get_string(&dlen);
341 debug("Exec command '%.500s'", command);
353 * Any unknown messages in this phase are ignored,
354 * and a failure message is returned.
356 logit("Unknown packet type received after authentication: %d", type);
358 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
362 /* Enable compression now that we have replied if appropriate. */
363 if (enable_compression_after_reply) {
364 enable_compression_after_reply = 0;
365 packet_start_compression(compression_level);
371 * This is called to fork and execute a command when we have no tty. This
372 * will call do_child from the child, and server_loop from the parent after
373 * setting up file descriptors and such.
376 do_exec_no_pty(Session *s, const char *command)
381 int pin[2], pout[2], perr[2];
382 /* Allocate pipes for communicating with the program. */
383 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
384 packet_disconnect("Could not create pipes: %.100s",
386 #else /* USE_PIPES */
387 int inout[2], err[2];
388 /* Uses socket pairs to communicate with the program. */
389 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
390 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
391 packet_disconnect("Could not create socket pairs: %.100s",
393 #endif /* USE_PIPES */
395 fatal("do_exec_no_pty: no session");
397 session_proctitle(s);
400 if (options.use_pam && !use_privsep)
404 /* Fork the child. */
405 if ((pid = fork()) == 0) {
408 /* Child. Reinitialize the log since the pid has changed. */
409 log_init(__progname, options.log_level, options.log_facility, log_stderr);
412 * Create a new session and process group since the 4.4BSD
413 * setlogin() affects the entire process group.
416 error("setsid failed: %.100s", strerror(errno));
420 * Redirect stdin. We close the parent side of the socket
421 * pair, and make the child side the standard input.
424 if (dup2(pin[0], 0) < 0)
425 perror("dup2 stdin");
428 /* Redirect stdout. */
430 if (dup2(pout[1], 1) < 0)
431 perror("dup2 stdout");
434 /* Redirect stderr. */
436 if (dup2(perr[1], 2) < 0)
437 perror("dup2 stderr");
439 #else /* USE_PIPES */
441 * Redirect stdin, stdout, and stderr. Stdin and stdout will
442 * use the same socket, as some programs (particularly rdist)
443 * seem to depend on it.
447 if (dup2(inout[0], 0) < 0) /* stdin */
448 perror("dup2 stdin");
449 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
450 perror("dup2 stdout");
451 if (dup2(err[0], 2) < 0) /* stderr */
452 perror("dup2 stderr");
453 #endif /* USE_PIPES */
456 cray_init_job(s->pw); /* set up cray jid and tmpdir */
459 /* Do processing for the child (exec command etc). */
460 do_child(s, command);
464 signal(WJSIGNAL, cray_job_termination_handler);
468 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
471 packet_disconnect("fork failed: %.100s", strerror(errno));
473 /* Set interactive/non-interactive mode. */
474 packet_set_interactive(s->display != NULL);
476 /* We are the parent. Close the child sides of the pipes. */
482 if (s->is_subsystem) {
486 session_set_fds(s, pin[1], pout[0], perr[0]);
488 /* Enter the interactive session. */
489 server_loop(pid, pin[1], pout[0], perr[0]);
490 /* server_loop has closed pin[1], pout[0], and perr[0]. */
492 #else /* USE_PIPES */
493 /* We are the parent. Close the child sides of the socket pairs. */
498 * Clear loginmsg, since it's the child's responsibility to display
499 * it to the user, otherwise multiple sessions may accumulate
500 * multiple copies of the login messages.
502 buffer_clear(&loginmsg);
505 * Enter the interactive session. Note: server_loop must be able to
506 * handle the case that fdin and fdout are the same.
509 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
511 server_loop(pid, inout[1], inout[1], err[1]);
512 /* server_loop has closed inout[1] and err[1]. */
514 #endif /* USE_PIPES */
518 * This is called to fork and execute a command when we have a tty. This
519 * will call do_child from the child, and server_loop from the parent after
520 * setting up file descriptors, controlling tty, updating wtmp, utmp,
521 * lastlog, and other such operations.
524 do_exec_pty(Session *s, const char *command)
526 int fdout, ptyfd, ttyfd, ptymaster;
530 fatal("do_exec_pty: no session");
535 if (options.use_pam) {
536 do_pam_set_tty(s->tty);
542 /* Fork the child. */
543 if ((pid = fork()) == 0) {
546 /* Child. Reinitialize the log because the pid has changed. */
547 log_init(__progname, options.log_level, options.log_facility, log_stderr);
548 /* Close the master side of the pseudo tty. */
551 /* Make the pseudo tty our controlling tty. */
552 pty_make_controlling_tty(&ttyfd, s->tty);
554 /* Redirect stdin/stdout/stderr from the pseudo tty. */
555 if (dup2(ttyfd, 0) < 0)
556 error("dup2 stdin: %s", strerror(errno));
557 if (dup2(ttyfd, 1) < 0)
558 error("dup2 stdout: %s", strerror(errno));
559 if (dup2(ttyfd, 2) < 0)
560 error("dup2 stderr: %s", strerror(errno));
562 /* Close the extra descriptor for the pseudo tty. */
565 /* record login, etc. similar to login(1) */
567 if (!(options.use_login && command == NULL)) {
569 cray_init_job(s->pw); /* set up cray jid and tmpdir */
571 do_login(s, command);
573 # ifdef LOGIN_NEEDS_UTMPX
579 /* Do common processing for the child, such as execing the command. */
580 do_child(s, command);
584 signal(WJSIGNAL, cray_job_termination_handler);
588 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
591 packet_disconnect("fork failed: %.100s", strerror(errno));
594 /* Parent. Close the slave side of the pseudo tty. */
598 * Create another descriptor of the pty master side for use as the
599 * standard input. We could use the original descriptor, but this
600 * simplifies code in server_loop. The descriptor is bidirectional.
604 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
606 /* we keep a reference to the pty master */
607 ptymaster = dup(ptyfd);
609 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
610 s->ptymaster = ptymaster;
612 /* Enter interactive session. */
613 packet_set_interactive(1);
615 session_set_fds(s, ptyfd, fdout, -1);
617 server_loop(pid, ptyfd, fdout, -1);
618 /* server_loop _has_ closed ptyfd and fdout. */
622 #ifdef LOGIN_NEEDS_UTMPX
624 do_pre_login(Session *s)
627 struct sockaddr_storage from;
628 pid_t pid = getpid();
631 * Get IP address of client. If the connection is not a socket, let
632 * the address be 0.0.0.0.
634 memset(&from, 0, sizeof(from));
635 fromlen = sizeof(from);
636 if (packet_connection_is_on_socket()) {
637 if (getpeername(packet_get_connection_in(),
638 (struct sockaddr *) & from, &fromlen) < 0) {
639 debug("getpeername: %.100s", strerror(errno));
644 record_utmp_only(pid, s->tty, s->pw->pw_name,
645 get_remote_name_or_ip(utmp_len, options.use_dns),
646 (struct sockaddr *)&from, fromlen);
651 * This is called to fork and execute a command. If another command is
652 * to be forced, execute that instead.
655 do_exec(Session *s, const char *command)
657 if (forced_command) {
658 original_command = command;
659 command = forced_command;
660 debug("Forced command '%.900s'", command);
663 #ifdef SSH_AUDIT_EVENTS
665 PRIVSEP(audit_run_command(command));
666 else if (s->ttyfd == -1) {
667 char *shell = s->pw->pw_shell;
669 if (shell[0] == '\0') /* empty shell means /bin/sh */
671 PRIVSEP(audit_run_command(shell));
676 do_exec_pty(s, command);
678 do_exec_no_pty(s, command);
680 original_command = NULL;
683 * Clear loginmsg: it's the child's responsibility to display
684 * it to the user, otherwise multiple sessions may accumulate
685 * multiple copies of the login messages.
687 buffer_clear(&loginmsg);
690 /* administrative, login(1)-like work */
692 do_login(Session *s, const char *command)
695 struct sockaddr_storage from;
696 struct passwd * pw = s->pw;
697 pid_t pid = getpid();
700 * Get IP address of client. If the connection is not a socket, let
701 * the address be 0.0.0.0.
703 memset(&from, 0, sizeof(from));
704 fromlen = sizeof(from);
705 if (packet_connection_is_on_socket()) {
706 if (getpeername(packet_get_connection_in(),
707 (struct sockaddr *) & from, &fromlen) < 0) {
708 debug("getpeername: %.100s", strerror(errno));
713 /* Record that there was a login on that tty from the remote host. */
715 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
716 get_remote_name_or_ip(utmp_len,
718 (struct sockaddr *)&from, fromlen);
722 * If password change is needed, do it now.
723 * This needs to occur before the ~/.hushlogin check.
725 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
728 s->authctxt->force_pwchange = 0;
729 /* XXX - signal [net] parent to enable forwardings */
733 if (check_quietlogin(s, command))
742 * Display the message of the day.
750 if (options.print_motd) {
751 #ifdef HAVE_LOGIN_CAP
752 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
755 f = fopen("/etc/motd", "r");
758 while (fgets(buf, sizeof(buf), f))
767 * Check for quiet login, either .hushlogin or command given.
770 check_quietlogin(Session *s, const char *command)
773 struct passwd *pw = s->pw;
776 /* Return 1 if .hushlogin exists or a command given. */
779 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
780 #ifdef HAVE_LOGIN_CAP
781 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
784 if (stat(buf, &st) >= 0)
791 * Sets the value of the given variable in the environment. If the variable
792 * already exists, its value is overriden.
795 child_set_env(char ***envp, u_int *envsizep, const char *name,
803 * If we're passed an uninitialized list, allocate a single null
804 * entry before continuing.
806 if (*envp == NULL && *envsizep == 0) {
807 *envp = xmalloc(sizeof(char *));
813 * Find the slot where the value should be stored. If the variable
814 * already exists, we reuse the slot; otherwise we append a new slot
815 * at the end of the array, expanding if necessary.
818 namelen = strlen(name);
819 for (i = 0; env[i]; i++)
820 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
823 /* Reuse the slot. */
826 /* New variable. Expand if necessary. */
828 if (i >= envsize - 1) {
830 fatal("child_set_env: too many env vars");
832 env = (*envp) = xrealloc(env, envsize * sizeof(char *));
835 /* Need to set the NULL pointer at end of array beyond the new slot. */
839 /* Allocate space and format the variable in the appropriate slot. */
840 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
841 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
845 * Reads environment variables from the given file and adds/overrides them
846 * into the environment. If the file does not exist, this does nothing.
847 * Otherwise, it must consist of empty lines, comments (line starts with '#')
848 * and assignments of the form name=value. No other forms are allowed.
851 read_environment_file(char ***env, u_int *envsize,
852 const char *filename)
859 f = fopen(filename, "r");
863 while (fgets(buf, sizeof(buf), f)) {
865 fatal("Too many lines in environment file %s", filename);
866 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
868 if (!*cp || *cp == '#' || *cp == '\n')
870 if (strchr(cp, '\n'))
871 *strchr(cp, '\n') = '\0';
872 value = strchr(cp, '=');
874 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
879 * Replace the equals sign by nul, and advance value to
884 child_set_env(env, envsize, cp, value);
889 #ifdef HAVE_ETC_DEFAULT_LOGIN
891 * Return named variable from specified environment, or NULL if not present.
894 child_get_env(char **env, const char *name)
900 for (i=0; env[i] != NULL; i++)
901 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
902 return(env[i] + len + 1);
907 * Read /etc/default/login.
908 * We pick up the PATH (or SUPATH for root) and UMASK.
911 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
913 char **tmpenv = NULL, *var;
914 u_int i, tmpenvsize = 0;
918 * We don't want to copy the whole file to the child's environment,
919 * so we use a temporary environment and copy the variables we're
922 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
928 var = child_get_env(tmpenv, "SUPATH");
930 var = child_get_env(tmpenv, "PATH");
932 child_set_env(env, envsize, "PATH", var);
934 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
935 if (sscanf(var, "%5lo", &mask) == 1)
938 for (i = 0; tmpenv[i] != NULL; i++)
942 #endif /* HAVE_ETC_DEFAULT_LOGIN */
945 copy_environment(char **source, char ***env, u_int *envsize)
947 char *var_name, *var_val;
953 for(i = 0; source[i] != NULL; i++) {
954 var_name = xstrdup(source[i]);
955 if ((var_val = strstr(var_name, "=")) == NULL) {
961 debug3("Copy environment: %s=%s", var_name, var_val);
962 child_set_env(env, envsize, var_name, var_val);
969 do_setup_env(Session *s, const char *shell)
973 char **env, *laddr, *path = NULL;
974 struct passwd *pw = s->pw;
976 /* Initialize the environment. */
978 env = xmalloc(envsize * sizeof(char *));
983 * The Windows environment contains some setting which are
984 * important for a running system. They must not be dropped.
989 p = fetch_windows_environment();
990 copy_environment(p, &env, &envsize);
991 free_windows_environment(p);
996 /* Allow any GSSAPI methods that we've used to alter
997 * the childs environment as they see fit
999 ssh_gssapi_do_child(&env, &envsize);
1002 if (!options.use_login) {
1003 /* Set basic environment. */
1004 for (i = 0; i < s->num_env; i++)
1005 child_set_env(&env, &envsize, s->env[i].name,
1008 child_set_env(&env, &envsize, "USER", pw->pw_name);
1009 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1011 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1013 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1014 #ifdef HAVE_LOGIN_CAP
1015 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1016 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1018 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1019 #else /* HAVE_LOGIN_CAP */
1020 # ifndef HAVE_CYGWIN
1022 * There's no standard path on Windows. The path contains
1023 * important components pointing to the system directories,
1024 * needed for loading shared libraries. So the path better
1025 * remains intact here.
1027 # ifdef HAVE_ETC_DEFAULT_LOGIN
1028 read_etc_default_login(&env, &envsize, pw->pw_uid);
1029 path = child_get_env(env, "PATH");
1030 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1031 if (path == NULL || *path == '\0') {
1032 child_set_env(&env, &envsize, "PATH",
1033 s->pw->pw_uid == 0 ?
1034 SUPERUSER_PATH : _PATH_STDPATH);
1036 # endif /* HAVE_CYGWIN */
1037 #endif /* HAVE_LOGIN_CAP */
1039 snprintf(buf, sizeof buf, "%.200s/%.50s",
1040 _PATH_MAILDIR, pw->pw_name);
1041 child_set_env(&env, &envsize, "MAIL", buf);
1043 /* Normal systems set SHELL by default. */
1044 child_set_env(&env, &envsize, "SHELL", shell);
1047 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1049 /* Set custom environment options from RSA authentication. */
1050 if (!options.use_login) {
1051 while (custom_environment) {
1052 struct envstring *ce = custom_environment;
1055 for (i = 0; str[i] != '=' && str[i]; i++)
1057 if (str[i] == '=') {
1059 child_set_env(&env, &envsize, str, str + i + 1);
1061 custom_environment = ce->next;
1067 /* SSH_CLIENT deprecated */
1068 snprintf(buf, sizeof buf, "%.50s %d %d",
1069 get_remote_ipaddr(), get_remote_port(), get_local_port());
1070 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1072 laddr = get_local_ipaddr(packet_get_connection_in());
1073 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1074 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1076 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1079 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1081 child_set_env(&env, &envsize, "TERM", s->term);
1083 child_set_env(&env, &envsize, "DISPLAY", s->display);
1084 if (original_command)
1085 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1089 if (cray_tmpdir[0] != '\0')
1090 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1091 #endif /* _UNICOS */
1094 * Since we clear KRB5CCNAME at startup, if it's set now then it
1095 * must have been set by a native authentication method (eg AIX or
1096 * SIA), so copy it to the child.
1101 if ((cp = getenv("KRB5CCNAME")) != NULL)
1102 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1109 if ((cp = getenv("AUTHSTATE")) != NULL)
1110 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1111 read_environment_file(&env, &envsize, "/etc/environment");
1115 if (s->authctxt->krb5_ccname)
1116 child_set_env(&env, &envsize, "KRB5CCNAME",
1117 s->authctxt->krb5_ccname);
1121 * Pull in any environment variables that may have
1124 if (options.use_pam) {
1127 p = fetch_pam_child_environment();
1128 copy_environment(p, &env, &envsize);
1129 free_pam_environment(p);
1131 p = fetch_pam_environment();
1132 copy_environment(p, &env, &envsize);
1133 free_pam_environment(p);
1135 #endif /* USE_PAM */
1137 if (auth_sock_name != NULL)
1138 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1141 /* read $HOME/.ssh/environment. */
1142 if (options.permit_user_env && !options.use_login) {
1143 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1144 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1145 read_environment_file(&env, &envsize, buf);
1148 /* dump the environment */
1149 fprintf(stderr, "Environment:\n");
1150 for (i = 0; env[i]; i++)
1151 fprintf(stderr, " %.200s\n", env[i]);
1157 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1158 * first in this order).
1161 do_rc_files(Session *s, const char *shell)
1169 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1171 /* ignore _PATH_SSH_USER_RC for subsystems */
1172 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1173 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1174 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1176 fprintf(stderr, "Running %s\n", cmd);
1177 f = popen(cmd, "w");
1180 fprintf(f, "%s %s\n", s->auth_proto,
1184 fprintf(stderr, "Could not run %s\n",
1186 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1188 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1189 _PATH_SSH_SYSTEM_RC);
1190 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1193 fprintf(f, "%s %s\n", s->auth_proto,
1197 fprintf(stderr, "Could not run %s\n",
1198 _PATH_SSH_SYSTEM_RC);
1199 } else if (do_xauth && options.xauth_location != NULL) {
1200 /* Add authority data to .Xauthority if appropriate. */
1203 "Running %.500s remove %.100s\n",
1204 options.xauth_location, s->auth_display);
1206 "%.500s add %.100s %.100s %.100s\n",
1207 options.xauth_location, s->auth_display,
1208 s->auth_proto, s->auth_data);
1210 snprintf(cmd, sizeof cmd, "%s -q -",
1211 options.xauth_location);
1212 f = popen(cmd, "w");
1214 fprintf(f, "remove %s\n",
1216 fprintf(f, "add %s %s %s\n",
1217 s->auth_display, s->auth_proto,
1221 fprintf(stderr, "Could not run %s\n",
1228 do_nologin(struct passwd *pw)
1233 #ifdef HAVE_LOGIN_CAP
1234 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1235 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1236 _PATH_NOLOGIN), "r");
1239 f = fopen(_PATH_NOLOGIN, "r");
1242 /* /etc/nologin exists. Print its contents and exit. */
1243 logit("User %.100s not allowed because %s exists",
1244 pw->pw_name, _PATH_NOLOGIN);
1245 while (fgets(buf, sizeof(buf), f))
1253 /* Set login name, uid, gid, and groups. */
1255 do_setusercontext(struct passwd *pw)
1258 if (getuid() == 0 || geteuid() == 0)
1259 #endif /* HAVE_CYGWIN */
1262 #ifdef HAVE_SETPCRED
1263 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1264 fatal("Failed to set process credentials");
1265 #endif /* HAVE_SETPCRED */
1266 #ifdef HAVE_LOGIN_CAP
1271 if (options.gss_authentication) {
1272 temporarily_use_uid(pw);
1273 ssh_gssapi_storecreds();
1278 if (options.use_pam) {
1282 # endif /* USE_PAM */
1283 if (setusercontext(lc, pw, pw->pw_uid,
1284 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1285 perror("unable to set user context");
1289 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1290 /* Sets login uid for accounting */
1291 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1292 error("setluid: %s", strerror(errno));
1293 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1295 if (setlogin(pw->pw_name) < 0)
1296 error("setlogin failed: %s", strerror(errno));
1297 if (setgid(pw->pw_gid) < 0) {
1301 /* Initialize the group list. */
1302 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1303 perror("initgroups");
1308 if (options.gss_authentication) {
1309 temporarily_use_uid(pw);
1310 ssh_gssapi_storecreds();
1316 * PAM credentials may take the form of supplementary groups.
1317 * These will have been wiped by the above initgroups() call.
1318 * Reestablish them here.
1320 if (options.use_pam) {
1324 # endif /* USE_PAM */
1325 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1326 irix_setusercontext(pw);
1327 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1331 #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
1332 if (set_id(pw->pw_name) != 0) {
1335 #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
1336 /* Permanently switch to the desired uid. */
1337 permanently_set_uid(pw);
1344 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1345 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1349 do_pwchange(Session *s)
1352 fprintf(stderr, "WARNING: Your password has expired.\n");
1353 if (s->ttyfd != -1) {
1355 "You must change your password now and login again!\n");
1356 #ifdef PASSWD_NEEDS_USERNAME
1357 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1360 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1365 "Password change required but no TTY available.\n");
1371 launch_login(struct passwd *pw, const char *hostname)
1373 /* Launch login(1). */
1375 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1376 #ifdef xxxLOGIN_NEEDS_TERM
1377 (s->term ? s->term : "unknown"),
1378 #endif /* LOGIN_NEEDS_TERM */
1379 #ifdef LOGIN_NO_ENDOPT
1380 "-p", "-f", pw->pw_name, (char *)NULL);
1382 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1385 /* Login couldn't be executed, die. */
1392 child_close_fds(void)
1396 if (packet_get_connection_in() == packet_get_connection_out())
1397 close(packet_get_connection_in());
1399 close(packet_get_connection_in());
1400 close(packet_get_connection_out());
1403 * Close all descriptors related to channels. They will still remain
1404 * open in the parent.
1406 /* XXX better use close-on-exec? -markus */
1407 channel_close_all();
1410 * Close any extra file descriptors. Note that there may still be
1411 * descriptors left by system functions. They will be closed later.
1416 * Close any extra open file descriptors so that we don't have them
1417 * hanging around in clients. Note that we want to do this after
1418 * initgroups, because at least on Solaris 2.3 it leaves file
1421 for (i = 3; i < 64; i++)
1426 * Performs common processing for the child, such as setting up the
1427 * environment, closing extra file descriptors, setting the user and group
1428 * ids, and executing the command or shell.
1431 do_child(Session *s, const char *command)
1433 extern char **environ;
1436 const char *shell, *shell0, *hostname = NULL;
1437 struct passwd *pw = s->pw;
1439 /* remove hostkey from the child's memory */
1440 destroy_sensitive_data();
1442 /* Force a password change */
1443 if (s->authctxt->force_pwchange) {
1444 do_setusercontext(pw);
1450 /* login(1) is only called if we execute the login shell */
1451 if (options.use_login && command != NULL)
1452 options.use_login = 0;
1455 cray_setup(pw->pw_uid, pw->pw_name, command);
1456 #endif /* _UNICOS */
1459 * Login(1) does this as well, and it needs uid 0 for the "-h"
1460 * switch, so we let login(1) to this for us.
1462 if (!options.use_login) {
1464 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1465 if (!check_quietlogin(s, command))
1467 #else /* HAVE_OSF_SIA */
1468 /* When PAM is enabled we rely on it to do the nologin check */
1469 if (!options.use_pam)
1471 do_setusercontext(pw);
1473 * PAM session modules in do_setusercontext may have
1474 * generated messages, so if this in an interactive
1475 * login then display them too.
1477 if (!check_quietlogin(s, command))
1479 #endif /* HAVE_OSF_SIA */
1483 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1484 debug3("PAM session not opened, exiting");
1491 * Get the shell from the password data. An empty shell field is
1492 * legal, and means /bin/sh.
1494 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1497 * Make sure $SHELL points to the shell from the password file,
1498 * even if shell is overridden from login.conf
1500 env = do_setup_env(s, shell);
1502 #ifdef HAVE_LOGIN_CAP
1503 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1506 /* we have to stash the hostname before we close our socket. */
1507 if (options.use_login)
1508 hostname = get_remote_name_or_ip(utmp_len,
1511 * Close the connection descriptors; note that this is the child, and
1512 * the server will still have the socket open, and it is important
1513 * that we do not shutdown it. Note that the descriptors cannot be
1514 * closed before building the environment, as we call
1515 * get_remote_ipaddr there.
1520 * Must take new environment into use so that .ssh/rc,
1521 * /etc/ssh/sshrc and xauth are run in the proper environment.
1525 #if defined(KRB5) && defined(USE_AFS)
1527 * At this point, we check to see if AFS is active and if we have
1528 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1529 * if we can (and need to) extend the ticket into an AFS token. If
1530 * we don't do this, we run into potential problems if the user's
1531 * home directory is in AFS and it's not world-readable.
1534 if (options.kerberos_get_afs_token && k_hasafs() &&
1535 (s->authctxt->krb5_ctx != NULL)) {
1538 debug("Getting AFS token");
1542 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1543 krb5_afslog(s->authctxt->krb5_ctx,
1544 s->authctxt->krb5_fwd_ccache, cell, NULL);
1546 krb5_afslog_home(s->authctxt->krb5_ctx,
1547 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1551 /* Change current directory to the user's home directory. */
1552 if (chdir(pw->pw_dir) < 0) {
1553 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1554 pw->pw_dir, strerror(errno));
1555 #ifdef HAVE_LOGIN_CAP
1556 if (login_getcapbool(lc, "requirehome", 0))
1561 if (!options.use_login)
1562 do_rc_files(s, shell);
1564 /* restore SIGPIPE for child */
1565 signal(SIGPIPE, SIG_DFL);
1567 if (options.use_login) {
1568 launch_login(pw, hostname);
1572 /* Get the last component of the shell name. */
1573 if ((shell0 = strrchr(shell, '/')) != NULL)
1579 * If we have no command, execute the shell. In this case, the shell
1580 * name to be passed in argv[0] is preceded by '-' to indicate that
1581 * this is a login shell.
1586 /* Start the shell. Set initial character to '-'. */
1589 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1590 >= sizeof(argv0) - 1) {
1596 /* Execute the shell. */
1599 execve(shell, argv, env);
1601 /* Executing the shell failed. */
1606 * Execute the command using the user's shell. This uses the -c
1607 * option to execute the command.
1609 argv[0] = (char *) shell0;
1611 argv[2] = (char *) command;
1613 execve(shell, argv, env);
1622 static int did_init = 0;
1624 debug("session_new: init");
1625 for (i = 0; i < MAX_SESSIONS; i++) {
1626 sessions[i].used = 0;
1630 for (i = 0; i < MAX_SESSIONS; i++) {
1631 Session *s = &sessions[i];
1633 memset(s, 0, sizeof(*s));
1639 s->x11_chanids = NULL;
1640 debug("session_new: session %d", i);
1651 for (i = 0; i < MAX_SESSIONS; i++) {
1652 Session *s = &sessions[i];
1653 debug("dump: used %d session %d %p channel %d pid %ld",
1663 session_open(Authctxt *authctxt, int chanid)
1665 Session *s = session_new();
1666 debug("session_open: channel %d", chanid);
1668 error("no more sessions");
1671 s->authctxt = authctxt;
1672 s->pw = authctxt->pw;
1673 if (s->pw == NULL || !authctxt->valid)
1674 fatal("no user for session %d", s->self);
1675 debug("session_open: session %d: link with channel %d", s->self, chanid);
1681 session_by_tty(char *tty)
1684 for (i = 0; i < MAX_SESSIONS; i++) {
1685 Session *s = &sessions[i];
1686 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1687 debug("session_by_tty: session %d tty %s", i, tty);
1691 debug("session_by_tty: unknown tty %.100s", tty);
1697 session_by_channel(int id)
1700 for (i = 0; i < MAX_SESSIONS; i++) {
1701 Session *s = &sessions[i];
1702 if (s->used && s->chanid == id) {
1703 debug("session_by_channel: session %d channel %d", i, id);
1707 debug("session_by_channel: unknown channel %d", id);
1713 session_by_x11_channel(int id)
1717 for (i = 0; i < MAX_SESSIONS; i++) {
1718 Session *s = &sessions[i];
1720 if (s->x11_chanids == NULL || !s->used)
1722 for (j = 0; s->x11_chanids[j] != -1; j++) {
1723 if (s->x11_chanids[j] == id) {
1724 debug("session_by_x11_channel: session %d "
1725 "channel %d", s->self, id);
1730 debug("session_by_x11_channel: unknown channel %d", id);
1736 session_by_pid(pid_t pid)
1739 debug("session_by_pid: pid %ld", (long)pid);
1740 for (i = 0; i < MAX_SESSIONS; i++) {
1741 Session *s = &sessions[i];
1742 if (s->used && s->pid == pid)
1745 error("session_by_pid: unknown pid %ld", (long)pid);
1751 session_window_change_req(Session *s)
1753 s->col = packet_get_int();
1754 s->row = packet_get_int();
1755 s->xpixel = packet_get_int();
1756 s->ypixel = packet_get_int();
1758 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1763 session_pty_req(Session *s)
1769 debug("Allocating a pty not permitted for this authentication.");
1772 if (s->ttyfd != -1) {
1773 packet_disconnect("Protocol error: you already have a pty.");
1777 s->term = packet_get_string(&len);
1780 s->col = packet_get_int();
1781 s->row = packet_get_int();
1783 s->row = packet_get_int();
1784 s->col = packet_get_int();
1786 s->xpixel = packet_get_int();
1787 s->ypixel = packet_get_int();
1789 if (strcmp(s->term, "") == 0) {
1794 /* Allocate a pty and open it. */
1795 debug("Allocating pty.");
1796 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1802 error("session_pty_req: session %d alloc failed", s->self);
1805 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1807 /* for SSH1 the tty modes length is not given */
1809 n_bytes = packet_remaining();
1810 tty_parse_modes(s->ttyfd, &n_bytes);
1813 pty_setowner(s->pw, s->tty);
1815 /* Set window size from the packet. */
1816 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1819 session_proctitle(s);
1824 session_subsystem_req(Session *s)
1829 char *cmd, *subsys = packet_get_string(&len);
1833 logit("subsystem request for %.100s", subsys);
1835 for (i = 0; i < options.num_subsystems; i++) {
1836 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1837 cmd = options.subsystem_command[i];
1838 if (stat(cmd, &st) < 0) {
1839 error("subsystem: cannot stat %s: %s", cmd,
1843 debug("subsystem: exec() %s", cmd);
1844 s->is_subsystem = 1;
1852 logit("subsystem request for %.100s failed, subsystem not found",
1860 session_x11_req(Session *s)
1864 if (s->auth_proto != NULL || s->auth_data != NULL) {
1865 error("session_x11_req: session %d: "
1866 "x11 forwarding already active", s->self);
1869 s->single_connection = packet_get_char();
1870 s->auth_proto = packet_get_string(NULL);
1871 s->auth_data = packet_get_string(NULL);
1872 s->screen = packet_get_int();
1875 success = session_setup_x11fwd(s);
1877 xfree(s->auth_proto);
1878 xfree(s->auth_data);
1879 s->auth_proto = NULL;
1880 s->auth_data = NULL;
1886 session_shell_req(Session *s)
1894 session_exec_req(Session *s)
1897 char *command = packet_get_string(&len);
1899 do_exec(s, command);
1905 session_break_req(Session *s)
1908 packet_get_int(); /* ignored */
1911 if (s->ttyfd == -1 ||
1912 tcsendbreak(s->ttyfd, 0) < 0)
1918 session_env_req(Session *s)
1921 u_int name_len, val_len, i;
1923 name = packet_get_string(&name_len);
1924 val = packet_get_string(&val_len);
1927 /* Don't set too many environment variables */
1928 if (s->num_env > 128) {
1929 debug2("Ignoring env request %s: too many env vars", name);
1933 for (i = 0; i < options.num_accept_env; i++) {
1934 if (match_pattern(name, options.accept_env[i])) {
1935 debug2("Setting env %d: %s=%s", s->num_env, name, val);
1936 s->env = xrealloc(s->env, sizeof(*s->env) *
1938 s->env[s->num_env].name = name;
1939 s->env[s->num_env].val = val;
1944 debug2("Ignoring env request %s: disallowed name", name);
1953 session_auth_agent_req(Session *s)
1955 static int called = 0;
1957 if (no_agent_forwarding_flag) {
1958 debug("session_auth_agent_req: no_agent_forwarding_flag");
1965 return auth_input_request_forwarding(s->pw);
1970 session_input_channel_req(Channel *c, const char *rtype)
1975 if ((s = session_by_channel(c->self)) == NULL) {
1976 logit("session_input_channel_req: no session %d req %.100s",
1980 debug("session_input_channel_req: session %d req %s", s->self, rtype);
1983 * a session is in LARVAL state until a shell, a command
1984 * or a subsystem is executed
1986 if (c->type == SSH_CHANNEL_LARVAL) {
1987 if (strcmp(rtype, "shell") == 0) {
1988 success = session_shell_req(s);
1989 } else if (strcmp(rtype, "exec") == 0) {
1990 success = session_exec_req(s);
1991 } else if (strcmp(rtype, "pty-req") == 0) {
1992 success = session_pty_req(s);
1993 } else if (strcmp(rtype, "x11-req") == 0) {
1994 success = session_x11_req(s);
1995 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1996 success = session_auth_agent_req(s);
1997 } else if (strcmp(rtype, "subsystem") == 0) {
1998 success = session_subsystem_req(s);
1999 } else if (strcmp(rtype, "env") == 0) {
2000 success = session_env_req(s);
2003 if (strcmp(rtype, "window-change") == 0) {
2004 success = session_window_change_req(s);
2005 } else if (strcmp(rtype, "break") == 0) {
2006 success = session_break_req(s);
2013 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2016 fatal("session_set_fds: called for proto != 2.0");
2018 * now that have a child and a pipe to the child,
2019 * we can activate our channel and register the fd's
2021 if (s->chanid == -1)
2022 fatal("no channel for session %d", s->self);
2023 if(options.hpn_disabled)
2024 channel_set_fds(s->chanid,
2026 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2028 CHAN_SES_WINDOW_DEFAULT);
2030 channel_set_fds(s->chanid,
2032 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2034 options.hpn_buffer_size);
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,
2379 options.hpn_disabled, options.hpn_buffer_size) == -1) {
2380 debug("x11_create_display_inet failed.");
2383 for (i = 0; s->x11_chanids[i] != -1; i++) {
2384 channel_register_cleanup(s->x11_chanids[i],
2385 session_close_single_x11, 0);
2388 /* Set up a suitable value for the DISPLAY variable. */
2389 if (gethostname(hostname, sizeof(hostname)) < 0)
2390 fatal("gethostname: %.100s", strerror(errno));
2392 * auth_display must be used as the displayname when the
2393 * authorization entry is added with xauth(1). This will be
2394 * different than the DISPLAY string for localhost displays.
2396 if (options.x11_use_localhost) {
2397 snprintf(display, sizeof display, "localhost:%u.%u",
2398 s->display_number, s->screen);
2399 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2400 s->display_number, s->screen);
2401 s->display = xstrdup(display);
2402 s->auth_display = xstrdup(auth_display);
2404 #ifdef IPADDR_IN_DISPLAY
2406 struct in_addr my_addr;
2408 he = gethostbyname(hostname);
2410 error("Can't get IP address for X11 DISPLAY.");
2411 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2414 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2415 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2416 s->display_number, s->screen);
2418 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2419 s->display_number, s->screen);
2421 s->display = xstrdup(display);
2422 s->auth_display = xstrdup(display);
2429 do_authenticated2(Authctxt *authctxt)
2431 server_loop2(authctxt);
2435 do_cleanup(Authctxt *authctxt)
2437 static int called = 0;
2439 debug("do_cleanup");
2441 /* no cleanup if we're in the child for login shell */
2445 /* avoid double cleanup */
2450 if (authctxt == NULL)
2453 if (options.kerberos_ticket_cleanup &&
2455 krb5_cleanup_proc(authctxt);
2459 if (compat20 && options.gss_cleanup_creds)
2460 ssh_gssapi_cleanup_creds();
2464 if (options.use_pam) {
2466 sshpam_thread_cleanup();
2470 /* remove agent socket */
2471 auth_sock_cleanup_proc(authctxt->pw);
2474 * Cleanup ptys/utmp only if privsep is disabled,
2475 * or if running in monitor.
2477 if (!use_privsep || mm_is_monitor())
2478 session_destroy_all(session_pty_cleanup2);