1 /* $OpenBSD: session.c,v 1.220 2006/10/09 23:36:11 djm Exp $ */
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * As far as I am concerned, the code I have written for this software
7 * can be used freely for any purpose. Any derived versions of this
8 * software must be clearly marked as such, and if the derived work is
9 * incompatible with the protocol description in the RFC file, it must be
10 * called by a name other than "ssh" or "Secure Shell".
12 * SSH2 support by Markus Friedl.
13 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 #include <sys/types.h>
39 #include <sys/param.h>
40 #ifdef HAVE_SYS_STAT_H
41 # include <sys/stat.h>
43 #include <sys/socket.h>
47 #include <arpa/inet.h>
80 #include "auth-options.h"
81 #include "pathnames.h"
85 #include "serverloop.h"
89 #include "monitor_wrap.h"
91 #if defined(KRB5) && defined(USE_AFS)
97 Session *session_new(void);
98 void session_set_fds(Session *, int, int, int);
99 void session_pty_cleanup(Session *);
100 void session_proctitle(Session *);
101 int session_setup_x11fwd(Session *);
102 void do_exec_pty(Session *, const char *);
103 void do_exec_no_pty(Session *, const char *);
104 void do_exec(Session *, const char *);
105 void do_login(Session *, const char *);
106 #ifdef LOGIN_NEEDS_UTMPX
107 static void do_pre_login(Session *s);
109 void do_child(Session *, const char *);
111 int check_quietlogin(Session *, const char *);
113 static void do_authenticated1(Authctxt *);
114 static void do_authenticated2(Authctxt *);
116 static int session_pty_req(Session *);
119 extern ServerOptions options;
120 extern char *__progname;
121 extern int log_stderr;
122 extern int debug_flag;
123 extern u_int utmp_len;
124 extern int startup_pipe;
125 extern void destroy_sensitive_data(void);
126 extern Buffer loginmsg;
128 /* original command from peer. */
129 const char *original_command = NULL;
132 #define MAX_SESSIONS 10
133 Session sessions[MAX_SESSIONS];
135 #ifdef HAVE_LOGIN_CAP
139 static int is_child = 0;
141 /* Name and directory of socket for authentication agent forwarding. */
142 static char *auth_sock_name = NULL;
143 static char *auth_sock_dir = NULL;
145 /* removes the agent forwarding socket */
148 auth_sock_cleanup_proc(struct passwd *pw)
150 if (auth_sock_name != NULL) {
151 temporarily_use_uid(pw);
152 unlink(auth_sock_name);
153 rmdir(auth_sock_dir);
154 auth_sock_name = NULL;
160 auth_input_request_forwarding(struct passwd * pw)
164 struct sockaddr_un sunaddr;
166 if (auth_sock_name != NULL) {
167 error("authentication forwarding requested twice.");
171 /* Temporarily drop privileged uid for mkdir/bind. */
172 temporarily_use_uid(pw);
174 /* Allocate a buffer for the socket name, and format the name. */
175 auth_sock_name = xmalloc(MAXPATHLEN);
176 auth_sock_dir = xmalloc(MAXPATHLEN);
177 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
179 /* Create private directory for socket */
180 if (mkdtemp(auth_sock_dir) == NULL) {
181 packet_send_debug("Agent forwarding disabled: "
182 "mkdtemp() failed: %.100s", strerror(errno));
184 xfree(auth_sock_name);
185 xfree(auth_sock_dir);
186 auth_sock_name = NULL;
187 auth_sock_dir = NULL;
190 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
191 auth_sock_dir, (long) getpid());
193 /* Create the socket. */
194 sock = socket(AF_UNIX, SOCK_STREAM, 0);
196 packet_disconnect("socket: %.100s", strerror(errno));
198 /* Bind it to the name. */
199 memset(&sunaddr, 0, sizeof(sunaddr));
200 sunaddr.sun_family = AF_UNIX;
201 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
203 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0)
204 packet_disconnect("bind: %.100s", strerror(errno));
206 /* Restore the privileged uid. */
209 /* Start listening on the socket. */
210 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
211 packet_disconnect("listen: %.100s", strerror(errno));
213 /* Allocate a channel for the authentication agent socket. */
214 nc = channel_new("auth socket",
215 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
216 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
217 0, "auth socket", 1);
218 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
223 display_loginmsg(void)
225 if (buffer_len(&loginmsg) > 0) {
226 buffer_append(&loginmsg, "\0", 1);
227 printf("%s", (char *)buffer_ptr(&loginmsg));
228 buffer_clear(&loginmsg);
233 do_authenticated(Authctxt *authctxt)
235 setproctitle("%s", authctxt->pw->pw_name);
237 /* setup the channel layer */
238 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
239 channel_permit_all_opens();
242 do_authenticated2(authctxt);
244 do_authenticated1(authctxt);
246 do_cleanup(authctxt);
250 * Prepares for an interactive session. This is called after the user has
251 * been successfully authenticated. During this message exchange, pseudo
252 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
253 * are requested, etc.
256 do_authenticated1(Authctxt *authctxt)
260 int success, type, screen_flag;
261 int enable_compression_after_reply = 0;
262 u_int proto_len, data_len, dlen, compression_level = 0;
266 error("no more sessions");
269 s->authctxt = authctxt;
270 s->pw = authctxt->pw;
273 * We stay in this loop until the client requests to execute a shell
279 /* Get a packet from the client. */
280 type = packet_read();
282 /* Process the packet. */
284 case SSH_CMSG_REQUEST_COMPRESSION:
285 compression_level = packet_get_int();
287 if (compression_level < 1 || compression_level > 9) {
288 packet_send_debug("Received invalid compression level %d.",
292 if (options.compression == COMP_NONE) {
293 debug2("compression disabled");
296 /* Enable compression after we have responded with SUCCESS. */
297 enable_compression_after_reply = 1;
301 case SSH_CMSG_REQUEST_PTY:
302 success = session_pty_req(s);
305 case SSH_CMSG_X11_REQUEST_FORWARDING:
306 s->auth_proto = packet_get_string(&proto_len);
307 s->auth_data = packet_get_string(&data_len);
309 screen_flag = packet_get_protocol_flags() &
310 SSH_PROTOFLAG_SCREEN_NUMBER;
311 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
313 if (packet_remaining() == 4) {
315 debug2("Buggy client: "
316 "X11 screen flag missing");
317 s->screen = packet_get_int();
322 success = session_setup_x11fwd(s);
324 xfree(s->auth_proto);
326 s->auth_proto = NULL;
331 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
332 if (no_agent_forwarding_flag || compat13) {
333 debug("Authentication agent forwarding not permitted for this authentication.");
336 debug("Received authentication agent forwarding request.");
337 success = auth_input_request_forwarding(s->pw);
340 case SSH_CMSG_PORT_FORWARD_REQUEST:
341 if (no_port_forwarding_flag) {
342 debug("Port forwarding not permitted for this authentication.");
345 if (!options.allow_tcp_forwarding) {
346 debug("Port forwarding not permitted.");
349 debug("Received TCP/IP port forwarding request.");
350 if (channel_input_port_forward_request(s->pw->pw_uid == 0,
351 options.gateway_ports) < 0) {
352 debug("Port forwarding failed.");
358 case SSH_CMSG_MAX_PACKET_SIZE:
359 if (packet_set_maxsize(packet_get_int()) > 0)
363 case SSH_CMSG_EXEC_SHELL:
364 case SSH_CMSG_EXEC_CMD:
365 if (type == SSH_CMSG_EXEC_CMD) {
366 command = packet_get_string(&dlen);
367 debug("Exec command '%.500s'", command);
379 * Any unknown messages in this phase are ignored,
380 * and a failure message is returned.
382 logit("Unknown packet type received after authentication: %d", type);
384 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
388 /* Enable compression now that we have replied if appropriate. */
389 if (enable_compression_after_reply) {
390 enable_compression_after_reply = 0;
391 packet_start_compression(compression_level);
397 * This is called to fork and execute a command when we have no tty. This
398 * will call do_child from the child, and server_loop from the parent after
399 * setting up file descriptors and such.
402 do_exec_no_pty(Session *s, const char *command)
407 int pin[2], pout[2], perr[2];
408 /* Allocate pipes for communicating with the program. */
409 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
410 packet_disconnect("Could not create pipes: %.100s",
412 #else /* USE_PIPES */
413 int inout[2], err[2];
414 /* Uses socket pairs to communicate with the program. */
415 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
416 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
417 packet_disconnect("Could not create socket pairs: %.100s",
419 #endif /* USE_PIPES */
421 fatal("do_exec_no_pty: no session");
423 session_proctitle(s);
426 if (options.use_pam && !use_privsep)
430 /* Fork the child. */
431 if ((pid = fork()) == 0) {
434 /* Child. Reinitialize the log since the pid has changed. */
435 log_init(__progname, options.log_level, options.log_facility, log_stderr);
438 * Create a new session and process group since the 4.4BSD
439 * setlogin() affects the entire process group.
442 error("setsid failed: %.100s", strerror(errno));
446 * Redirect stdin. We close the parent side of the socket
447 * pair, and make the child side the standard input.
450 if (dup2(pin[0], 0) < 0)
451 perror("dup2 stdin");
454 /* Redirect stdout. */
456 if (dup2(pout[1], 1) < 0)
457 perror("dup2 stdout");
460 /* Redirect stderr. */
462 if (dup2(perr[1], 2) < 0)
463 perror("dup2 stderr");
465 #else /* USE_PIPES */
467 * Redirect stdin, stdout, and stderr. Stdin and stdout will
468 * use the same socket, as some programs (particularly rdist)
469 * seem to depend on it.
473 if (dup2(inout[0], 0) < 0) /* stdin */
474 perror("dup2 stdin");
475 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
476 perror("dup2 stdout");
477 if (dup2(err[0], 2) < 0) /* stderr */
478 perror("dup2 stderr");
479 #endif /* USE_PIPES */
482 cray_init_job(s->pw); /* set up cray jid and tmpdir */
485 /* Do processing for the child (exec command etc). */
486 do_child(s, command);
490 signal(WJSIGNAL, cray_job_termination_handler);
494 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
497 packet_disconnect("fork failed: %.100s", strerror(errno));
499 /* Set interactive/non-interactive mode. */
500 packet_set_interactive(s->display != NULL);
502 /* We are the parent. Close the child sides of the pipes. */
508 if (s->is_subsystem) {
512 session_set_fds(s, pin[1], pout[0], perr[0]);
514 /* Enter the interactive session. */
515 server_loop(pid, pin[1], pout[0], perr[0]);
516 /* server_loop has closed pin[1], pout[0], and perr[0]. */
518 #else /* USE_PIPES */
519 /* We are the parent. Close the child sides of the socket pairs. */
524 * Clear loginmsg, since it's the child's responsibility to display
525 * it to the user, otherwise multiple sessions may accumulate
526 * multiple copies of the login messages.
528 buffer_clear(&loginmsg);
531 * Enter the interactive session. Note: server_loop must be able to
532 * handle the case that fdin and fdout are the same.
535 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
537 server_loop(pid, inout[1], inout[1], err[1]);
538 /* server_loop has closed inout[1] and err[1]. */
540 #endif /* USE_PIPES */
544 * This is called to fork and execute a command when we have a tty. This
545 * will call do_child from the child, and server_loop from the parent after
546 * setting up file descriptors, controlling tty, updating wtmp, utmp,
547 * lastlog, and other such operations.
550 do_exec_pty(Session *s, const char *command)
552 int fdout, ptyfd, ttyfd, ptymaster;
556 fatal("do_exec_pty: no session");
561 if (options.use_pam) {
562 do_pam_set_tty(s->tty);
568 /* Fork the child. */
569 if ((pid = fork()) == 0) {
572 /* Child. Reinitialize the log because the pid has changed. */
573 log_init(__progname, options.log_level, options.log_facility, log_stderr);
574 /* Close the master side of the pseudo tty. */
577 /* Make the pseudo tty our controlling tty. */
578 pty_make_controlling_tty(&ttyfd, s->tty);
580 /* Redirect stdin/stdout/stderr from the pseudo tty. */
581 if (dup2(ttyfd, 0) < 0)
582 error("dup2 stdin: %s", strerror(errno));
583 if (dup2(ttyfd, 1) < 0)
584 error("dup2 stdout: %s", strerror(errno));
585 if (dup2(ttyfd, 2) < 0)
586 error("dup2 stderr: %s", strerror(errno));
588 /* Close the extra descriptor for the pseudo tty. */
591 /* record login, etc. similar to login(1) */
593 if (!(options.use_login && command == NULL)) {
595 cray_init_job(s->pw); /* set up cray jid and tmpdir */
597 do_login(s, command);
599 # ifdef LOGIN_NEEDS_UTMPX
605 /* Do common processing for the child, such as execing the command. */
606 do_child(s, command);
610 signal(WJSIGNAL, cray_job_termination_handler);
614 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
617 packet_disconnect("fork failed: %.100s", strerror(errno));
620 /* Parent. Close the slave side of the pseudo tty. */
624 * Create another descriptor of the pty master side for use as the
625 * standard input. We could use the original descriptor, but this
626 * simplifies code in server_loop. The descriptor is bidirectional.
630 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
632 /* we keep a reference to the pty master */
633 ptymaster = dup(ptyfd);
635 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
636 s->ptymaster = ptymaster;
638 /* Enter interactive session. */
639 packet_set_interactive(1);
641 session_set_fds(s, ptyfd, fdout, -1);
643 server_loop(pid, ptyfd, fdout, -1);
644 /* server_loop _has_ closed ptyfd and fdout. */
648 #ifdef LOGIN_NEEDS_UTMPX
650 do_pre_login(Session *s)
653 struct sockaddr_storage from;
654 pid_t pid = getpid();
657 * Get IP address of client. If the connection is not a socket, let
658 * the address be 0.0.0.0.
660 memset(&from, 0, sizeof(from));
661 fromlen = sizeof(from);
662 if (packet_connection_is_on_socket()) {
663 if (getpeername(packet_get_connection_in(),
664 (struct sockaddr *)&from, &fromlen) < 0) {
665 debug("getpeername: %.100s", strerror(errno));
670 record_utmp_only(pid, s->tty, s->pw->pw_name,
671 get_remote_name_or_ip(utmp_len, options.use_dns),
672 (struct sockaddr *)&from, fromlen);
677 * This is called to fork and execute a command. If another command is
678 * to be forced, execute that instead.
681 do_exec(Session *s, const char *command)
683 if (options.adm_forced_command) {
684 original_command = command;
685 command = options.adm_forced_command;
686 debug("Forced command (config) '%.900s'", command);
687 } else if (forced_command) {
688 original_command = command;
689 command = forced_command;
690 debug("Forced command (key option) '%.900s'", command);
693 #ifdef SSH_AUDIT_EVENTS
695 PRIVSEP(audit_run_command(command));
696 else if (s->ttyfd == -1) {
697 char *shell = s->pw->pw_shell;
699 if (shell[0] == '\0') /* empty shell means /bin/sh */
701 PRIVSEP(audit_run_command(shell));
706 do_exec_pty(s, command);
708 do_exec_no_pty(s, command);
710 original_command = NULL;
713 * Clear loginmsg: it's the child's responsibility to display
714 * it to the user, otherwise multiple sessions may accumulate
715 * multiple copies of the login messages.
717 buffer_clear(&loginmsg);
720 /* administrative, login(1)-like work */
722 do_login(Session *s, const char *command)
725 struct sockaddr_storage from;
726 struct passwd * pw = s->pw;
727 pid_t pid = getpid();
730 * Get IP address of client. If the connection is not a socket, let
731 * the address be 0.0.0.0.
733 memset(&from, 0, sizeof(from));
734 fromlen = sizeof(from);
735 if (packet_connection_is_on_socket()) {
736 if (getpeername(packet_get_connection_in(),
737 (struct sockaddr *) & from, &fromlen) < 0) {
738 debug("getpeername: %.100s", strerror(errno));
743 /* Record that there was a login on that tty from the remote host. */
745 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
746 get_remote_name_or_ip(utmp_len,
748 (struct sockaddr *)&from, fromlen);
752 * If password change is needed, do it now.
753 * This needs to occur before the ~/.hushlogin check.
755 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
758 s->authctxt->force_pwchange = 0;
759 /* XXX - signal [net] parent to enable forwardings */
763 if (check_quietlogin(s, command))
772 * Display the message of the day.
780 if (options.print_motd) {
781 #ifdef HAVE_LOGIN_CAP
782 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
785 f = fopen("/etc/motd", "r");
788 while (fgets(buf, sizeof(buf), f))
797 * Check for quiet login, either .hushlogin or command given.
800 check_quietlogin(Session *s, const char *command)
803 struct passwd *pw = s->pw;
806 /* Return 1 if .hushlogin exists or a command given. */
809 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
810 #ifdef HAVE_LOGIN_CAP
811 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
814 if (stat(buf, &st) >= 0)
821 * Sets the value of the given variable in the environment. If the variable
822 * already exists, its value is overriden.
825 child_set_env(char ***envp, u_int *envsizep, const char *name,
833 * If we're passed an uninitialized list, allocate a single null
834 * entry before continuing.
836 if (*envp == NULL && *envsizep == 0) {
837 *envp = xmalloc(sizeof(char *));
843 * Find the slot where the value should be stored. If the variable
844 * already exists, we reuse the slot; otherwise we append a new slot
845 * at the end of the array, expanding if necessary.
848 namelen = strlen(name);
849 for (i = 0; env[i]; i++)
850 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
853 /* Reuse the slot. */
856 /* New variable. Expand if necessary. */
858 if (i >= envsize - 1) {
860 fatal("child_set_env: too many env vars");
862 env = (*envp) = xrealloc(env, envsize, sizeof(char *));
865 /* Need to set the NULL pointer at end of array beyond the new slot. */
869 /* Allocate space and format the variable in the appropriate slot. */
870 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
871 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
875 * Reads environment variables from the given file and adds/overrides them
876 * into the environment. If the file does not exist, this does nothing.
877 * Otherwise, it must consist of empty lines, comments (line starts with '#')
878 * and assignments of the form name=value. No other forms are allowed.
881 read_environment_file(char ***env, u_int *envsize,
882 const char *filename)
889 f = fopen(filename, "r");
893 while (fgets(buf, sizeof(buf), f)) {
895 fatal("Too many lines in environment file %s", filename);
896 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
898 if (!*cp || *cp == '#' || *cp == '\n')
900 if (strchr(cp, '\n'))
901 *strchr(cp, '\n') = '\0';
902 value = strchr(cp, '=');
904 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
909 * Replace the equals sign by nul, and advance value to
914 child_set_env(env, envsize, cp, value);
919 #ifdef HAVE_ETC_DEFAULT_LOGIN
921 * Return named variable from specified environment, or NULL if not present.
924 child_get_env(char **env, const char *name)
930 for (i=0; env[i] != NULL; i++)
931 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
932 return(env[i] + len + 1);
937 * Read /etc/default/login.
938 * We pick up the PATH (or SUPATH for root) and UMASK.
941 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
943 char **tmpenv = NULL, *var;
944 u_int i, tmpenvsize = 0;
948 * We don't want to copy the whole file to the child's environment,
949 * so we use a temporary environment and copy the variables we're
952 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
958 var = child_get_env(tmpenv, "SUPATH");
960 var = child_get_env(tmpenv, "PATH");
962 child_set_env(env, envsize, "PATH", var);
964 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
965 if (sscanf(var, "%5lo", &mask) == 1)
968 for (i = 0; tmpenv[i] != NULL; i++)
972 #endif /* HAVE_ETC_DEFAULT_LOGIN */
975 copy_environment(char **source, char ***env, u_int *envsize)
977 char *var_name, *var_val;
983 for(i = 0; source[i] != NULL; i++) {
984 var_name = xstrdup(source[i]);
985 if ((var_val = strstr(var_name, "=")) == NULL) {
991 debug3("Copy environment: %s=%s", var_name, var_val);
992 child_set_env(env, envsize, var_name, var_val);
999 do_setup_env(Session *s, const char *shell)
1004 struct passwd *pw = s->pw;
1005 #ifndef HAVE_LOGIN_CAP
1009 /* Initialize the environment. */
1011 env = xcalloc(envsize, sizeof(char *));
1016 * The Windows environment contains some setting which are
1017 * important for a running system. They must not be dropped.
1022 p = fetch_windows_environment();
1023 copy_environment(p, &env, &envsize);
1024 free_windows_environment(p);
1029 /* Allow any GSSAPI methods that we've used to alter
1030 * the childs environment as they see fit
1032 ssh_gssapi_do_child(&env, &envsize);
1035 if (!options.use_login) {
1036 /* Set basic environment. */
1037 for (i = 0; i < s->num_env; i++)
1038 child_set_env(&env, &envsize, s->env[i].name,
1041 child_set_env(&env, &envsize, "USER", pw->pw_name);
1042 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1044 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1046 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1047 #ifdef HAVE_LOGIN_CAP
1048 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1049 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1051 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1052 #else /* HAVE_LOGIN_CAP */
1053 # ifndef HAVE_CYGWIN
1055 * There's no standard path on Windows. The path contains
1056 * important components pointing to the system directories,
1057 * needed for loading shared libraries. So the path better
1058 * remains intact here.
1060 # ifdef HAVE_ETC_DEFAULT_LOGIN
1061 read_etc_default_login(&env, &envsize, pw->pw_uid);
1062 path = child_get_env(env, "PATH");
1063 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1064 if (path == NULL || *path == '\0') {
1065 child_set_env(&env, &envsize, "PATH",
1066 s->pw->pw_uid == 0 ?
1067 SUPERUSER_PATH : _PATH_STDPATH);
1069 # endif /* HAVE_CYGWIN */
1070 #endif /* HAVE_LOGIN_CAP */
1072 snprintf(buf, sizeof buf, "%.200s/%.50s",
1073 _PATH_MAILDIR, pw->pw_name);
1074 child_set_env(&env, &envsize, "MAIL", buf);
1076 /* Normal systems set SHELL by default. */
1077 child_set_env(&env, &envsize, "SHELL", shell);
1080 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1082 /* Set custom environment options from RSA authentication. */
1083 if (!options.use_login) {
1084 while (custom_environment) {
1085 struct envstring *ce = custom_environment;
1088 for (i = 0; str[i] != '=' && str[i]; i++)
1090 if (str[i] == '=') {
1092 child_set_env(&env, &envsize, str, str + i + 1);
1094 custom_environment = ce->next;
1100 /* SSH_CLIENT deprecated */
1101 snprintf(buf, sizeof buf, "%.50s %d %d",
1102 get_remote_ipaddr(), get_remote_port(), get_local_port());
1103 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1105 laddr = get_local_ipaddr(packet_get_connection_in());
1106 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1107 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1109 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1112 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1114 child_set_env(&env, &envsize, "TERM", s->term);
1116 child_set_env(&env, &envsize, "DISPLAY", s->display);
1117 if (original_command)
1118 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1122 if (cray_tmpdir[0] != '\0')
1123 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1124 #endif /* _UNICOS */
1127 * Since we clear KRB5CCNAME at startup, if it's set now then it
1128 * must have been set by a native authentication method (eg AIX or
1129 * SIA), so copy it to the child.
1134 if ((cp = getenv("KRB5CCNAME")) != NULL)
1135 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1142 if ((cp = getenv("AUTHSTATE")) != NULL)
1143 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1144 read_environment_file(&env, &envsize, "/etc/environment");
1148 if (s->authctxt->krb5_ccname)
1149 child_set_env(&env, &envsize, "KRB5CCNAME",
1150 s->authctxt->krb5_ccname);
1154 * Pull in any environment variables that may have
1157 if (options.use_pam) {
1160 p = fetch_pam_child_environment();
1161 copy_environment(p, &env, &envsize);
1162 free_pam_environment(p);
1164 p = fetch_pam_environment();
1165 copy_environment(p, &env, &envsize);
1166 free_pam_environment(p);
1168 #endif /* USE_PAM */
1170 if (auth_sock_name != NULL)
1171 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1174 /* read $HOME/.ssh/environment. */
1175 if (options.permit_user_env && !options.use_login) {
1176 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1177 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1178 read_environment_file(&env, &envsize, buf);
1181 /* dump the environment */
1182 fprintf(stderr, "Environment:\n");
1183 for (i = 0; env[i]; i++)
1184 fprintf(stderr, " %.200s\n", env[i]);
1190 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1191 * first in this order).
1194 do_rc_files(Session *s, const char *shell)
1202 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1204 /* ignore _PATH_SSH_USER_RC for subsystems */
1205 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1206 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1207 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1209 fprintf(stderr, "Running %s\n", cmd);
1210 f = popen(cmd, "w");
1213 fprintf(f, "%s %s\n", s->auth_proto,
1217 fprintf(stderr, "Could not run %s\n",
1219 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1221 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1222 _PATH_SSH_SYSTEM_RC);
1223 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1226 fprintf(f, "%s %s\n", s->auth_proto,
1230 fprintf(stderr, "Could not run %s\n",
1231 _PATH_SSH_SYSTEM_RC);
1232 } else if (do_xauth && options.xauth_location != NULL) {
1233 /* Add authority data to .Xauthority if appropriate. */
1236 "Running %.500s remove %.100s\n",
1237 options.xauth_location, s->auth_display);
1239 "%.500s add %.100s %.100s %.100s\n",
1240 options.xauth_location, s->auth_display,
1241 s->auth_proto, s->auth_data);
1243 snprintf(cmd, sizeof cmd, "%s -q -",
1244 options.xauth_location);
1245 f = popen(cmd, "w");
1247 fprintf(f, "remove %s\n",
1249 fprintf(f, "add %s %s %s\n",
1250 s->auth_display, s->auth_proto,
1254 fprintf(stderr, "Could not run %s\n",
1261 do_nologin(struct passwd *pw)
1266 #ifdef HAVE_LOGIN_CAP
1267 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1268 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1269 _PATH_NOLOGIN), "r");
1272 f = fopen(_PATH_NOLOGIN, "r");
1275 /* /etc/nologin exists. Print its contents and exit. */
1276 logit("User %.100s not allowed because %s exists",
1277 pw->pw_name, _PATH_NOLOGIN);
1278 while (fgets(buf, sizeof(buf), f))
1286 /* Set login name, uid, gid, and groups. */
1288 do_setusercontext(struct passwd *pw)
1291 if (getuid() == 0 || geteuid() == 0)
1292 #endif /* HAVE_CYGWIN */
1295 #ifdef HAVE_SETPCRED
1296 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1297 fatal("Failed to set process credentials");
1298 #endif /* HAVE_SETPCRED */
1299 #ifdef HAVE_LOGIN_CAP
1304 if (options.gss_authentication) {
1305 temporarily_use_uid(pw);
1306 ssh_gssapi_storecreds();
1311 if (options.use_pam) {
1315 # endif /* USE_PAM */
1316 if (setusercontext(lc, pw, pw->pw_uid,
1317 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1318 perror("unable to set user context");
1322 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1323 /* Sets login uid for accounting */
1324 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1325 error("setluid: %s", strerror(errno));
1326 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1328 if (setlogin(pw->pw_name) < 0)
1329 error("setlogin failed: %s", strerror(errno));
1330 if (setgid(pw->pw_gid) < 0) {
1334 /* Initialize the group list. */
1335 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1336 perror("initgroups");
1341 if (options.gss_authentication) {
1342 temporarily_use_uid(pw);
1343 ssh_gssapi_storecreds();
1349 * PAM credentials may take the form of supplementary groups.
1350 * These will have been wiped by the above initgroups() call.
1351 * Reestablish them here.
1353 if (options.use_pam) {
1357 # endif /* USE_PAM */
1358 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1359 irix_setusercontext(pw);
1360 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1364 #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
1365 if (set_id(pw->pw_name) != 0) {
1368 #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
1369 /* Permanently switch to the desired uid. */
1370 permanently_set_uid(pw);
1377 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1378 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1381 ssh_selinux_setup_exec_context(pw->pw_name);
1386 do_pwchange(Session *s)
1389 fprintf(stderr, "WARNING: Your password has expired.\n");
1390 if (s->ttyfd != -1) {
1392 "You must change your password now and login again!\n");
1393 #ifdef PASSWD_NEEDS_USERNAME
1394 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1397 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1402 "Password change required but no TTY available.\n");
1408 launch_login(struct passwd *pw, const char *hostname)
1410 /* Launch login(1). */
1412 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1413 #ifdef xxxLOGIN_NEEDS_TERM
1414 (s->term ? s->term : "unknown"),
1415 #endif /* LOGIN_NEEDS_TERM */
1416 #ifdef LOGIN_NO_ENDOPT
1417 "-p", "-f", pw->pw_name, (char *)NULL);
1419 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1422 /* Login couldn't be executed, die. */
1429 child_close_fds(void)
1433 if (packet_get_connection_in() == packet_get_connection_out())
1434 close(packet_get_connection_in());
1436 close(packet_get_connection_in());
1437 close(packet_get_connection_out());
1440 * Close all descriptors related to channels. They will still remain
1441 * open in the parent.
1443 /* XXX better use close-on-exec? -markus */
1444 channel_close_all();
1447 * Close any extra file descriptors. Note that there may still be
1448 * descriptors left by system functions. They will be closed later.
1453 * Close any extra open file descriptors so that we don't have them
1454 * hanging around in clients. Note that we want to do this after
1455 * initgroups, because at least on Solaris 2.3 it leaves file
1458 for (i = 3; i < 64; i++)
1463 * Performs common processing for the child, such as setting up the
1464 * environment, closing extra file descriptors, setting the user and group
1465 * ids, and executing the command or shell.
1468 do_child(Session *s, const char *command)
1470 extern char **environ;
1473 const char *shell, *shell0, *hostname = NULL;
1474 struct passwd *pw = s->pw;
1476 /* remove hostkey from the child's memory */
1477 destroy_sensitive_data();
1479 /* Force a password change */
1480 if (s->authctxt->force_pwchange) {
1481 do_setusercontext(pw);
1487 /* login(1) is only called if we execute the login shell */
1488 if (options.use_login && command != NULL)
1489 options.use_login = 0;
1492 cray_setup(pw->pw_uid, pw->pw_name, command);
1493 #endif /* _UNICOS */
1496 * Login(1) does this as well, and it needs uid 0 for the "-h"
1497 * switch, so we let login(1) to this for us.
1499 if (!options.use_login) {
1501 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1502 if (!check_quietlogin(s, command))
1504 #else /* HAVE_OSF_SIA */
1505 /* When PAM is enabled we rely on it to do the nologin check */
1506 if (!options.use_pam)
1508 do_setusercontext(pw);
1510 * PAM session modules in do_setusercontext may have
1511 * generated messages, so if this in an interactive
1512 * login then display them too.
1514 if (!check_quietlogin(s, command))
1516 #endif /* HAVE_OSF_SIA */
1520 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1521 debug3("PAM session not opened, exiting");
1528 * Get the shell from the password data. An empty shell field is
1529 * legal, and means /bin/sh.
1531 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1534 * Make sure $SHELL points to the shell from the password file,
1535 * even if shell is overridden from login.conf
1537 env = do_setup_env(s, shell);
1539 #ifdef HAVE_LOGIN_CAP
1540 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1543 /* we have to stash the hostname before we close our socket. */
1544 if (options.use_login)
1545 hostname = get_remote_name_or_ip(utmp_len,
1548 * Close the connection descriptors; note that this is the child, and
1549 * the server will still have the socket open, and it is important
1550 * that we do not shutdown it. Note that the descriptors cannot be
1551 * closed before building the environment, as we call
1552 * get_remote_ipaddr there.
1557 * Must take new environment into use so that .ssh/rc,
1558 * /etc/ssh/sshrc and xauth are run in the proper environment.
1562 #if defined(KRB5) && defined(USE_AFS)
1564 * At this point, we check to see if AFS is active and if we have
1565 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1566 * if we can (and need to) extend the ticket into an AFS token. If
1567 * we don't do this, we run into potential problems if the user's
1568 * home directory is in AFS and it's not world-readable.
1571 if (options.kerberos_get_afs_token && k_hasafs() &&
1572 (s->authctxt->krb5_ctx != NULL)) {
1575 debug("Getting AFS token");
1579 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1580 krb5_afslog(s->authctxt->krb5_ctx,
1581 s->authctxt->krb5_fwd_ccache, cell, NULL);
1583 krb5_afslog_home(s->authctxt->krb5_ctx,
1584 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1588 /* Change current directory to the user's home directory. */
1589 if (chdir(pw->pw_dir) < 0) {
1590 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1591 pw->pw_dir, strerror(errno));
1592 #ifdef HAVE_LOGIN_CAP
1593 if (login_getcapbool(lc, "requirehome", 0))
1598 if (!options.use_login)
1599 do_rc_files(s, shell);
1601 /* restore SIGPIPE for child */
1602 signal(SIGPIPE, SIG_DFL);
1604 if (options.use_login) {
1605 launch_login(pw, hostname);
1609 /* Get the last component of the shell name. */
1610 if ((shell0 = strrchr(shell, '/')) != NULL)
1616 * If we have no command, execute the shell. In this case, the shell
1617 * name to be passed in argv[0] is preceded by '-' to indicate that
1618 * this is a login shell.
1623 /* Start the shell. Set initial character to '-'. */
1626 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1627 >= sizeof(argv0) - 1) {
1633 /* Execute the shell. */
1636 execve(shell, argv, env);
1638 /* Executing the shell failed. */
1643 * Execute the command using the user's shell. This uses the -c
1644 * option to execute the command.
1646 argv[0] = (char *) shell0;
1648 argv[2] = (char *) command;
1650 execve(shell, argv, env);
1659 static int did_init = 0;
1661 debug("session_new: init");
1662 for (i = 0; i < MAX_SESSIONS; i++) {
1663 sessions[i].used = 0;
1667 for (i = 0; i < MAX_SESSIONS; i++) {
1668 Session *s = &sessions[i];
1670 memset(s, 0, sizeof(*s));
1676 s->x11_chanids = NULL;
1677 debug("session_new: session %d", i);
1688 for (i = 0; i < MAX_SESSIONS; i++) {
1689 Session *s = &sessions[i];
1690 debug("dump: used %d session %d %p channel %d pid %ld",
1700 session_open(Authctxt *authctxt, int chanid)
1702 Session *s = session_new();
1703 debug("session_open: channel %d", chanid);
1705 error("no more sessions");
1708 s->authctxt = authctxt;
1709 s->pw = authctxt->pw;
1710 if (s->pw == NULL || !authctxt->valid)
1711 fatal("no user for session %d", s->self);
1712 debug("session_open: session %d: link with channel %d", s->self, chanid);
1718 session_by_tty(char *tty)
1721 for (i = 0; i < MAX_SESSIONS; i++) {
1722 Session *s = &sessions[i];
1723 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1724 debug("session_by_tty: session %d tty %s", i, tty);
1728 debug("session_by_tty: unknown tty %.100s", tty);
1734 session_by_channel(int id)
1737 for (i = 0; i < MAX_SESSIONS; i++) {
1738 Session *s = &sessions[i];
1739 if (s->used && s->chanid == id) {
1740 debug("session_by_channel: session %d channel %d", i, id);
1744 debug("session_by_channel: unknown channel %d", id);
1750 session_by_x11_channel(int id)
1754 for (i = 0; i < MAX_SESSIONS; i++) {
1755 Session *s = &sessions[i];
1757 if (s->x11_chanids == NULL || !s->used)
1759 for (j = 0; s->x11_chanids[j] != -1; j++) {
1760 if (s->x11_chanids[j] == id) {
1761 debug("session_by_x11_channel: session %d "
1762 "channel %d", s->self, id);
1767 debug("session_by_x11_channel: unknown channel %d", id);
1773 session_by_pid(pid_t pid)
1776 debug("session_by_pid: pid %ld", (long)pid);
1777 for (i = 0; i < MAX_SESSIONS; i++) {
1778 Session *s = &sessions[i];
1779 if (s->used && s->pid == pid)
1782 error("session_by_pid: unknown pid %ld", (long)pid);
1788 session_window_change_req(Session *s)
1790 s->col = packet_get_int();
1791 s->row = packet_get_int();
1792 s->xpixel = packet_get_int();
1793 s->ypixel = packet_get_int();
1795 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1800 session_pty_req(Session *s)
1806 debug("Allocating a pty not permitted for this authentication.");
1809 if (s->ttyfd != -1) {
1810 packet_disconnect("Protocol error: you already have a pty.");
1814 s->term = packet_get_string(&len);
1817 s->col = packet_get_int();
1818 s->row = packet_get_int();
1820 s->row = packet_get_int();
1821 s->col = packet_get_int();
1823 s->xpixel = packet_get_int();
1824 s->ypixel = packet_get_int();
1826 if (strcmp(s->term, "") == 0) {
1831 /* Allocate a pty and open it. */
1832 debug("Allocating pty.");
1833 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1839 error("session_pty_req: session %d alloc failed", s->self);
1842 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1844 /* for SSH1 the tty modes length is not given */
1846 n_bytes = packet_remaining();
1847 tty_parse_modes(s->ttyfd, &n_bytes);
1850 pty_setowner(s->pw, s->tty);
1852 /* Set window size from the packet. */
1853 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1856 session_proctitle(s);
1861 session_subsystem_req(Session *s)
1866 char *prog, *cmd, *subsys = packet_get_string(&len);
1870 logit("subsystem request for %.100s", subsys);
1872 for (i = 0; i < options.num_subsystems; i++) {
1873 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1874 prog = options.subsystem_command[i];
1875 cmd = options.subsystem_args[i];
1876 if (stat(prog, &st) < 0) {
1877 error("subsystem: cannot stat %s: %s", prog,
1881 debug("subsystem: exec() %s", cmd);
1882 s->is_subsystem = 1;
1890 logit("subsystem request for %.100s failed, subsystem not found",
1898 session_x11_req(Session *s)
1902 if (s->auth_proto != NULL || s->auth_data != NULL) {
1903 error("session_x11_req: session %d: "
1904 "x11 forwarding already active", s->self);
1907 s->single_connection = packet_get_char();
1908 s->auth_proto = packet_get_string(NULL);
1909 s->auth_data = packet_get_string(NULL);
1910 s->screen = packet_get_int();
1913 success = session_setup_x11fwd(s);
1915 xfree(s->auth_proto);
1916 xfree(s->auth_data);
1917 s->auth_proto = NULL;
1918 s->auth_data = NULL;
1924 session_shell_req(Session *s)
1932 session_exec_req(Session *s)
1935 char *command = packet_get_string(&len);
1937 do_exec(s, command);
1943 session_break_req(Session *s)
1946 packet_get_int(); /* ignored */
1949 if (s->ttyfd == -1 ||
1950 tcsendbreak(s->ttyfd, 0) < 0)
1956 session_env_req(Session *s)
1959 u_int name_len, val_len, i;
1961 name = packet_get_string(&name_len);
1962 val = packet_get_string(&val_len);
1965 /* Don't set too many environment variables */
1966 if (s->num_env > 128) {
1967 debug2("Ignoring env request %s: too many env vars", name);
1971 for (i = 0; i < options.num_accept_env; i++) {
1972 if (match_pattern(name, options.accept_env[i])) {
1973 debug2("Setting env %d: %s=%s", s->num_env, name, val);
1974 s->env = xrealloc(s->env, s->num_env + 1,
1976 s->env[s->num_env].name = name;
1977 s->env[s->num_env].val = val;
1982 debug2("Ignoring env request %s: disallowed name", name);
1991 session_auth_agent_req(Session *s)
1993 static int called = 0;
1995 if (no_agent_forwarding_flag) {
1996 debug("session_auth_agent_req: no_agent_forwarding_flag");
2003 return auth_input_request_forwarding(s->pw);
2008 session_input_channel_req(Channel *c, const char *rtype)
2013 if ((s = session_by_channel(c->self)) == NULL) {
2014 logit("session_input_channel_req: no session %d req %.100s",
2018 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2021 * a session is in LARVAL state until a shell, a command
2022 * or a subsystem is executed
2024 if (c->type == SSH_CHANNEL_LARVAL) {
2025 if (strcmp(rtype, "shell") == 0) {
2026 success = session_shell_req(s);
2027 } else if (strcmp(rtype, "exec") == 0) {
2028 success = session_exec_req(s);
2029 } else if (strcmp(rtype, "pty-req") == 0) {
2030 success = session_pty_req(s);
2031 } else if (strcmp(rtype, "x11-req") == 0) {
2032 success = session_x11_req(s);
2033 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2034 success = session_auth_agent_req(s);
2035 } else if (strcmp(rtype, "subsystem") == 0) {
2036 success = session_subsystem_req(s);
2037 } else if (strcmp(rtype, "env") == 0) {
2038 success = session_env_req(s);
2041 if (strcmp(rtype, "window-change") == 0) {
2042 success = session_window_change_req(s);
2043 } else if (strcmp(rtype, "break") == 0) {
2044 success = session_break_req(s);
2051 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2054 fatal("session_set_fds: called for proto != 2.0");
2056 * now that have a child and a pipe to the child,
2057 * we can activate our channel and register the fd's
2059 if (s->chanid == -1)
2060 fatal("no channel for session %d", s->self);
2061 channel_set_fds(s->chanid,
2063 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2065 CHAN_SES_WINDOW_DEFAULT);
2069 * Function to perform pty cleanup. Also called if we get aborted abnormally
2070 * (e.g., due to a dropped connection).
2073 session_pty_cleanup2(Session *s)
2076 error("session_pty_cleanup: no session");
2082 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2084 /* Record that the user has logged out. */
2086 record_logout(s->pid, s->tty, s->pw->pw_name);
2088 /* Release the pseudo-tty. */
2090 pty_release(s->tty);
2093 * Close the server side of the socket pairs. We must do this after
2094 * the pty cleanup, so that another process doesn't get this pty
2095 * while we're still cleaning up.
2097 if (close(s->ptymaster) < 0)
2098 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2100 /* unlink pty from session */
2105 session_pty_cleanup(Session *s)
2107 PRIVSEP(session_pty_cleanup2(s));
2113 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2128 return "SIG@openssh.com";
2132 session_close_x11(int id)
2136 if ((c = channel_by_id(id)) == NULL) {
2137 debug("session_close_x11: x11 channel %d missing", id);
2139 /* Detach X11 listener */
2140 debug("session_close_x11: detach x11 channel %d", id);
2141 channel_cancel_cleanup(id);
2142 if (c->ostate != CHAN_OUTPUT_CLOSED)
2148 session_close_single_x11(int id, void *arg)
2153 debug3("session_close_single_x11: channel %d", id);
2154 channel_cancel_cleanup(id);
2155 if ((s = session_by_x11_channel(id)) == NULL)
2156 fatal("session_close_single_x11: no x11 channel %d", id);
2157 for (i = 0; s->x11_chanids[i] != -1; i++) {
2158 debug("session_close_single_x11: session %d: "
2159 "closing channel %d", s->self, s->x11_chanids[i]);
2161 * The channel "id" is already closing, but make sure we
2162 * close all of its siblings.
2164 if (s->x11_chanids[i] != id)
2165 session_close_x11(s->x11_chanids[i]);
2167 xfree(s->x11_chanids);
2168 s->x11_chanids = NULL;
2173 if (s->auth_proto) {
2174 xfree(s->auth_proto);
2175 s->auth_proto = NULL;
2178 xfree(s->auth_data);
2179 s->auth_data = NULL;
2181 if (s->auth_display) {
2182 xfree(s->auth_display);
2183 s->auth_display = NULL;
2188 session_exit_message(Session *s, int status)
2192 if ((c = channel_lookup(s->chanid)) == NULL)
2193 fatal("session_exit_message: session %d: no channel %d",
2194 s->self, s->chanid);
2195 debug("session_exit_message: session %d channel %d pid %ld",
2196 s->self, s->chanid, (long)s->pid);
2198 if (WIFEXITED(status)) {
2199 channel_request_start(s->chanid, "exit-status", 0);
2200 packet_put_int(WEXITSTATUS(status));
2202 } else if (WIFSIGNALED(status)) {
2203 channel_request_start(s->chanid, "exit-signal", 0);
2204 packet_put_cstring(sig2name(WTERMSIG(status)));
2206 packet_put_char(WCOREDUMP(status));
2207 #else /* WCOREDUMP */
2209 #endif /* WCOREDUMP */
2210 packet_put_cstring("");
2211 packet_put_cstring("");
2214 /* Some weird exit cause. Just exit. */
2215 packet_disconnect("wait returned status %04x.", status);
2218 /* disconnect channel */
2219 debug("session_exit_message: release channel %d", s->chanid);
2222 * Adjust cleanup callback attachment to send close messages when
2223 * the channel gets EOF. The session will be then be closed
2224 * by session_close_by_channel when the childs close their fds.
2226 channel_register_cleanup(c->self, session_close_by_channel, 1);
2229 * emulate a write failure with 'chan_write_failed', nobody will be
2230 * interested in data we write.
2231 * Note that we must not call 'chan_read_failed', since there could
2232 * be some more data waiting in the pipe.
2234 if (c->ostate != CHAN_OUTPUT_CLOSED)
2235 chan_write_failed(c);
2239 session_close(Session *s)
2243 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2245 session_pty_cleanup(s);
2251 xfree(s->x11_chanids);
2252 if (s->auth_display)
2253 xfree(s->auth_display);
2255 xfree(s->auth_data);
2257 xfree(s->auth_proto);
2259 if (s->env != NULL) {
2260 for (i = 0; i < s->num_env; i++) {
2261 xfree(s->env[i].name);
2262 xfree(s->env[i].val);
2266 session_proctitle(s);
2270 session_close_by_pid(pid_t pid, int status)
2272 Session *s = session_by_pid(pid);
2274 debug("session_close_by_pid: no session for pid %ld",
2278 if (s->chanid != -1)
2279 session_exit_message(s, status);
2281 session_pty_cleanup(s);
2286 * this is called when a channel dies before
2287 * the session 'child' itself dies
2290 session_close_by_channel(int id, void *arg)
2292 Session *s = session_by_channel(id);
2296 debug("session_close_by_channel: no session for id %d", id);
2299 debug("session_close_by_channel: channel %d child %ld",
2302 debug("session_close_by_channel: channel %d: has child", id);
2304 * delay detach of session, but release pty, since
2305 * the fd's to the child are already closed
2308 session_pty_cleanup(s);
2311 /* detach by removing callback */
2312 channel_cancel_cleanup(s->chanid);
2314 /* Close any X11 listeners associated with this session */
2315 if (s->x11_chanids != NULL) {
2316 for (i = 0; s->x11_chanids[i] != -1; i++) {
2317 session_close_x11(s->x11_chanids[i]);
2318 s->x11_chanids[i] = -1;
2327 session_destroy_all(void (*closefunc)(Session *))
2330 for (i = 0; i < MAX_SESSIONS; i++) {
2331 Session *s = &sessions[i];
2333 if (closefunc != NULL)
2342 session_tty_list(void)
2344 static char buf[1024];
2349 for (i = 0; i < MAX_SESSIONS; i++) {
2350 Session *s = &sessions[i];
2351 if (s->used && s->ttyfd != -1) {
2353 if (strncmp(s->tty, "/dev/", 5) != 0) {
2354 cp = strrchr(s->tty, '/');
2355 cp = (cp == NULL) ? s->tty : cp + 1;
2360 strlcat(buf, ",", sizeof buf);
2361 strlcat(buf, cp, sizeof buf);
2365 strlcpy(buf, "notty", sizeof buf);
2370 session_proctitle(Session *s)
2373 error("no user for session %d", s->self);
2375 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2379 session_setup_x11fwd(Session *s)
2382 char display[512], auth_display[512];
2383 char hostname[MAXHOSTNAMELEN];
2386 if (no_x11_forwarding_flag) {
2387 packet_send_debug("X11 forwarding disabled in user configuration file.");
2390 if (!options.x11_forwarding) {
2391 debug("X11 forwarding disabled in server configuration file.");
2394 if (!options.xauth_location ||
2395 (stat(options.xauth_location, &st) == -1)) {
2396 packet_send_debug("No xauth program; cannot forward with spoofing.");
2399 if (options.use_login) {
2400 packet_send_debug("X11 forwarding disabled; "
2401 "not compatible with UseLogin=yes.");
2404 if (s->display != NULL) {
2405 debug("X11 display already set.");
2408 if (x11_create_display_inet(options.x11_display_offset,
2409 options.x11_use_localhost, s->single_connection,
2410 &s->display_number, &s->x11_chanids) == -1) {
2411 debug("x11_create_display_inet failed.");
2414 for (i = 0; s->x11_chanids[i] != -1; i++) {
2415 channel_register_cleanup(s->x11_chanids[i],
2416 session_close_single_x11, 0);
2419 /* Set up a suitable value for the DISPLAY variable. */
2420 if (gethostname(hostname, sizeof(hostname)) < 0)
2421 fatal("gethostname: %.100s", strerror(errno));
2423 * auth_display must be used as the displayname when the
2424 * authorization entry is added with xauth(1). This will be
2425 * different than the DISPLAY string for localhost displays.
2427 if (options.x11_use_localhost) {
2428 snprintf(display, sizeof display, "localhost:%u.%u",
2429 s->display_number, s->screen);
2430 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2431 s->display_number, s->screen);
2432 s->display = xstrdup(display);
2433 s->auth_display = xstrdup(auth_display);
2435 #ifdef IPADDR_IN_DISPLAY
2437 struct in_addr my_addr;
2439 he = gethostbyname(hostname);
2441 error("Can't get IP address for X11 DISPLAY.");
2442 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2445 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2446 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2447 s->display_number, s->screen);
2449 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2450 s->display_number, s->screen);
2452 s->display = xstrdup(display);
2453 s->auth_display = xstrdup(display);
2460 do_authenticated2(Authctxt *authctxt)
2462 server_loop2(authctxt);
2466 do_cleanup(Authctxt *authctxt)
2468 static int called = 0;
2470 debug("do_cleanup");
2472 /* no cleanup if we're in the child for login shell */
2476 /* avoid double cleanup */
2481 if (authctxt == NULL || !authctxt->authenticated)
2484 if (options.kerberos_ticket_cleanup &&
2486 krb5_cleanup_proc(authctxt);
2490 if (compat20 && options.gss_cleanup_creds)
2491 ssh_gssapi_cleanup_creds();
2495 if (options.use_pam) {
2497 sshpam_thread_cleanup();
2501 /* remove agent socket */
2502 auth_sock_cleanup_proc(authctxt->pw);
2505 * Cleanup ptys/utmp only if privsep is disabled,
2506 * or if running in monitor.
2508 if (!use_privsep || mm_is_monitor())
2509 session_destroy_all(session_pty_cleanup2);