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 1.148 2002/08/29 15:57:25 stevesk Exp $");
51 #include "auth-options.h"
52 #include "pathnames.h"
56 #include "serverloop.h"
59 #include "monitor_wrap.h"
63 #include <sys/cygwin.h>
64 #define is_winnt (GetVersion() < 0x80000000)
69 Session *session_new(void);
70 void session_set_fds(Session *, int, int, int);
71 void session_pty_cleanup(void *);
72 void session_proctitle(Session *);
73 int session_setup_x11fwd(Session *);
74 void do_exec_pty(Session *, const char *);
75 void do_exec_no_pty(Session *, const char *);
76 void do_exec(Session *, const char *);
77 void do_login(Session *, const char *);
78 #ifdef LOGIN_NEEDS_UTMPX
79 static void do_pre_login(Session *s);
81 void do_child(Session *, const char *);
83 int check_quietlogin(Session *, const char *);
85 static void do_authenticated1(Authctxt *);
86 static void do_authenticated2(Authctxt *);
88 static int session_pty_req(Session *);
91 extern ServerOptions options;
92 extern char *__progname;
93 extern int log_stderr;
94 extern int debug_flag;
95 extern u_int utmp_len;
96 extern int startup_pipe;
97 extern void destroy_sensitive_data(void);
99 /* original command from peer. */
100 const char *original_command = NULL;
103 #define MAX_SESSIONS 10
104 Session sessions[MAX_SESSIONS];
106 #ifdef WITH_AIXAUTHENTICATE
108 #endif /* WITH_AIXAUTHENTICATE */
110 #ifdef HAVE_LOGIN_CAP
114 /* Name and directory of socket for authentication agent forwarding. */
115 static char *auth_sock_name = NULL;
116 static char *auth_sock_dir = NULL;
118 /* removes the agent forwarding socket */
121 auth_sock_cleanup_proc(void *_pw)
123 struct passwd *pw = _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-XXXXXXXX", 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 /* delete agent socket on fatal() */
169 fatal_add_cleanup(auth_sock_cleanup_proc, pw);
171 /* Create the socket. */
172 sock = socket(AF_UNIX, SOCK_STREAM, 0);
174 packet_disconnect("socket: %.100s", strerror(errno));
176 /* Bind it to the name. */
177 memset(&sunaddr, 0, sizeof(sunaddr));
178 sunaddr.sun_family = AF_UNIX;
179 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
181 if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
182 packet_disconnect("bind: %.100s", strerror(errno));
184 /* Restore the privileged uid. */
187 /* Start listening on the socket. */
188 if (listen(sock, 5) < 0)
189 packet_disconnect("listen: %.100s", strerror(errno));
191 /* Allocate a channel for the authentication agent socket. */
192 nc = channel_new("auth socket",
193 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
194 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
195 0, xstrdup("auth socket"), 1);
196 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
202 do_authenticated(Authctxt *authctxt)
205 * Cancel the alarm we set to limit the time taken for
209 if (startup_pipe != -1) {
213 #ifdef WITH_AIXAUTHENTICATE
214 /* We don't have a pty yet, so just label the line as "ssh" */
215 if (loginsuccess(authctxt->user,
216 get_canonical_hostname(options.verify_reverse_mapping),
217 "ssh", &aixloginmsg) < 0)
219 #endif /* WITH_AIXAUTHENTICATE */
221 /* setup the channel layer */
222 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
223 channel_permit_all_opens();
226 do_authenticated2(authctxt);
228 do_authenticated1(authctxt);
230 /* remove agent socket */
231 if (auth_sock_name != NULL)
232 auth_sock_cleanup_proc(authctxt->pw);
234 if (options.kerberos_ticket_cleanup)
235 krb4_cleanup_proc(authctxt);
238 if (options.kerberos_ticket_cleanup)
239 krb5_cleanup_proc(authctxt);
244 * Prepares for an interactive session. This is called after the user has
245 * been successfully authenticated. During this message exchange, pseudo
246 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
247 * are requested, etc.
250 do_authenticated1(Authctxt *authctxt)
254 int success, type, screen_flag;
255 int enable_compression_after_reply = 0;
256 u_int proto_len, data_len, dlen, compression_level = 0;
259 s->authctxt = authctxt;
260 s->pw = authctxt->pw;
263 * We stay in this loop until the client requests to execute a shell
269 /* Get a packet from the client. */
270 type = packet_read();
272 /* Process the packet. */
274 case SSH_CMSG_REQUEST_COMPRESSION:
275 compression_level = packet_get_int();
277 if (compression_level < 1 || compression_level > 9) {
278 packet_send_debug("Received illegal compression level %d.",
282 if (!options.compression) {
283 debug2("compression disabled");
286 /* Enable compression after we have responded with SUCCESS. */
287 enable_compression_after_reply = 1;
291 case SSH_CMSG_REQUEST_PTY:
292 success = session_pty_req(s);
295 case SSH_CMSG_X11_REQUEST_FORWARDING:
296 s->auth_proto = packet_get_string(&proto_len);
297 s->auth_data = packet_get_string(&data_len);
299 screen_flag = packet_get_protocol_flags() &
300 SSH_PROTOFLAG_SCREEN_NUMBER;
301 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
303 if (packet_remaining() == 4) {
305 debug2("Buggy client: "
306 "X11 screen flag missing");
307 s->screen = packet_get_int();
312 success = session_setup_x11fwd(s);
314 xfree(s->auth_proto);
316 s->auth_proto = NULL;
321 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
322 if (no_agent_forwarding_flag || compat13) {
323 debug("Authentication agent forwarding not permitted for this authentication.");
326 debug("Received authentication agent forwarding request.");
327 success = auth_input_request_forwarding(s->pw);
330 case SSH_CMSG_PORT_FORWARD_REQUEST:
331 if (no_port_forwarding_flag) {
332 debug("Port forwarding not permitted for this authentication.");
335 if (!options.allow_tcp_forwarding) {
336 debug("Port forwarding not permitted.");
339 debug("Received TCP/IP port forwarding request.");
340 channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
344 case SSH_CMSG_MAX_PACKET_SIZE:
345 if (packet_set_maxsize(packet_get_int()) > 0)
349 #if defined(AFS) || defined(KRB5)
350 case SSH_CMSG_HAVE_KERBEROS_TGT:
351 if (!options.kerberos_tgt_passing) {
352 verbose("Kerberos TGT passing disabled.");
354 char *kdata = packet_get_string(&dlen);
357 /* XXX - 0x41, see creds_to_radix version */
358 if (kdata[0] != 0x41) {
364 if (auth_krb5_tgt(s->authctxt, &tgt))
367 verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user);
371 if (auth_krb4_tgt(s->authctxt, kdata))
374 verbose("Kerberos v4 TGT refused for %.100s", s->authctxt->user);
380 #endif /* AFS || KRB5 */
383 case SSH_CMSG_HAVE_AFS_TOKEN:
384 if (!options.afs_token_passing || !k_hasafs()) {
385 verbose("AFS token passing disabled.");
387 /* Accept AFS token. */
388 char *token = packet_get_string(&dlen);
391 if (auth_afs_token(s->authctxt, token))
394 verbose("AFS token refused for %.100s",
401 case SSH_CMSG_EXEC_SHELL:
402 case SSH_CMSG_EXEC_CMD:
403 if (type == SSH_CMSG_EXEC_CMD) {
404 command = packet_get_string(&dlen);
405 debug("Exec command '%.500s'", command);
417 * Any unknown messages in this phase are ignored,
418 * and a failure message is returned.
420 log("Unknown packet type received after authentication: %d", type);
422 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
426 /* Enable compression now that we have replied if appropriate. */
427 if (enable_compression_after_reply) {
428 enable_compression_after_reply = 0;
429 packet_start_compression(compression_level);
435 * This is called to fork and execute a command when we have no tty. This
436 * will call do_child from the child, and server_loop from the parent after
437 * setting up file descriptors and such.
440 do_exec_no_pty(Session *s, const char *command)
445 int pin[2], pout[2], perr[2];
446 /* Allocate pipes for communicating with the program. */
447 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
448 packet_disconnect("Could not create pipes: %.100s",
450 #else /* USE_PIPES */
451 int inout[2], err[2];
452 /* Uses socket pairs to communicate with the program. */
453 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
454 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
455 packet_disconnect("Could not create socket pairs: %.100s",
457 #endif /* USE_PIPES */
459 fatal("do_exec_no_pty: no session");
461 session_proctitle(s);
464 do_pam_session(s->pw->pw_name, NULL);
466 if (is_pam_password_change_required())
467 packet_disconnect("Password change required but no "
471 /* Fork the child. */
472 if ((pid = fork()) == 0) {
473 fatal_remove_all_cleanups();
475 /* Child. Reinitialize the log since the pid has changed. */
476 log_init(__progname, options.log_level, options.log_facility, log_stderr);
479 * Create a new session and process group since the 4.4BSD
480 * setlogin() affects the entire process group.
483 error("setsid failed: %.100s", strerror(errno));
487 * Redirect stdin. We close the parent side of the socket
488 * pair, and make the child side the standard input.
491 if (dup2(pin[0], 0) < 0)
492 perror("dup2 stdin");
495 /* Redirect stdout. */
497 if (dup2(pout[1], 1) < 0)
498 perror("dup2 stdout");
501 /* Redirect stderr. */
503 if (dup2(perr[1], 2) < 0)
504 perror("dup2 stderr");
506 #else /* USE_PIPES */
508 * Redirect stdin, stdout, and stderr. Stdin and stdout will
509 * use the same socket, as some programs (particularly rdist)
510 * seem to depend on it.
514 if (dup2(inout[0], 0) < 0) /* stdin */
515 perror("dup2 stdin");
516 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
517 perror("dup2 stdout");
518 if (dup2(err[0], 2) < 0) /* stderr */
519 perror("dup2 stderr");
520 #endif /* USE_PIPES */
522 /* Do processing for the child (exec command etc). */
523 do_child(s, command);
528 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
531 packet_disconnect("fork failed: %.100s", strerror(errno));
533 /* Set interactive/non-interactive mode. */
534 packet_set_interactive(s->display != NULL);
536 /* We are the parent. Close the child sides of the pipes. */
542 session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
544 /* Enter the interactive session. */
545 server_loop(pid, pin[1], pout[0], perr[0]);
546 /* server_loop has closed pin[1], pout[0], and perr[0]. */
548 #else /* USE_PIPES */
549 /* We are the parent. Close the child sides of the socket pairs. */
554 * Enter the interactive session. Note: server_loop must be able to
555 * handle the case that fdin and fdout are the same.
558 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
560 server_loop(pid, inout[1], inout[1], err[1]);
561 /* server_loop has closed inout[1] and err[1]. */
563 #endif /* USE_PIPES */
567 * This is called to fork and execute a command when we have a tty. This
568 * will call do_child from the child, and server_loop from the parent after
569 * setting up file descriptors, controlling tty, updating wtmp, utmp,
570 * lastlog, and other such operations.
573 do_exec_pty(Session *s, const char *command)
575 int fdout, ptyfd, ttyfd, ptymaster;
579 fatal("do_exec_pty: no session");
584 do_pam_session(s->pw->pw_name, s->tty);
588 /* Fork the child. */
589 if ((pid = fork()) == 0) {
590 fatal_remove_all_cleanups();
592 /* Child. Reinitialize the log because the pid has changed. */
593 log_init(__progname, options.log_level, options.log_facility, log_stderr);
594 /* Close the master side of the pseudo tty. */
597 /* Make the pseudo tty our controlling tty. */
598 pty_make_controlling_tty(&ttyfd, s->tty);
600 /* Redirect stdin/stdout/stderr from the pseudo tty. */
601 if (dup2(ttyfd, 0) < 0)
602 error("dup2 stdin: %s", strerror(errno));
603 if (dup2(ttyfd, 1) < 0)
604 error("dup2 stdout: %s", strerror(errno));
605 if (dup2(ttyfd, 2) < 0)
606 error("dup2 stderr: %s", strerror(errno));
608 /* Close the extra descriptor for the pseudo tty. */
611 /* record login, etc. similar to login(1) */
613 if (!(options.use_login && command == NULL))
614 do_login(s, command);
615 # ifdef LOGIN_NEEDS_UTMPX
621 /* Do common processing for the child, such as execing the command. */
622 do_child(s, command);
627 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
630 packet_disconnect("fork failed: %.100s", strerror(errno));
633 /* Parent. Close the slave side of the pseudo tty. */
637 * Create another descriptor of the pty master side for use as the
638 * standard input. We could use the original descriptor, but this
639 * simplifies code in server_loop. The descriptor is bidirectional.
643 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
645 /* we keep a reference to the pty master */
646 ptymaster = dup(ptyfd);
648 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
649 s->ptymaster = ptymaster;
651 /* Enter interactive session. */
652 packet_set_interactive(1);
654 session_set_fds(s, ptyfd, fdout, -1);
656 server_loop(pid, ptyfd, fdout, -1);
657 /* server_loop _has_ closed ptyfd and fdout. */
661 #ifdef LOGIN_NEEDS_UTMPX
663 do_pre_login(Session *s)
666 struct sockaddr_storage from;
667 pid_t pid = getpid();
670 * Get IP address of client. If the connection is not a socket, let
671 * the address be 0.0.0.0.
673 memset(&from, 0, sizeof(from));
674 fromlen = sizeof(from);
675 if (packet_connection_is_on_socket()) {
676 if (getpeername(packet_get_connection_in(),
677 (struct sockaddr *) & from, &fromlen) < 0) {
678 debug("getpeername: %.100s", strerror(errno));
683 record_utmp_only(pid, s->tty, s->pw->pw_name,
684 get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping),
685 (struct sockaddr *)&from);
690 * This is called to fork and execute a command. If another command is
691 * to be forced, execute that instead.
694 do_exec(Session *s, const char *command)
696 if (forced_command) {
697 original_command = command;
698 command = forced_command;
699 debug("Forced command '%.900s'", command);
703 do_exec_pty(s, command);
705 do_exec_no_pty(s, command);
707 original_command = NULL;
711 /* administrative, login(1)-like work */
713 do_login(Session *s, const char *command)
717 struct sockaddr_storage from;
718 struct passwd * pw = s->pw;
719 pid_t pid = getpid();
722 * Get IP address of client. If the connection is not a socket, let
723 * the address be 0.0.0.0.
725 memset(&from, 0, sizeof(from));
726 if (packet_connection_is_on_socket()) {
727 fromlen = sizeof(from);
728 if (getpeername(packet_get_connection_in(),
729 (struct sockaddr *) & from, &fromlen) < 0) {
730 debug("getpeername: %.100s", strerror(errno));
735 /* Record that there was a login on that tty from the remote host. */
737 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
738 get_remote_name_or_ip(utmp_len,
739 options.verify_reverse_mapping),
740 (struct sockaddr *)&from, fromlen);
744 * If password change is needed, do it now.
745 * This needs to occur before the ~/.hushlogin check.
747 if (is_pam_password_change_required()) {
748 print_pam_messages();
753 if (check_quietlogin(s, command))
757 if (!is_pam_password_change_required())
758 print_pam_messages();
760 #ifdef WITH_AIXAUTHENTICATE
761 if (aixloginmsg && *aixloginmsg)
762 printf("%s\n", aixloginmsg);
763 #endif /* WITH_AIXAUTHENTICATE */
765 if (options.print_lastlog && s->last_login_time != 0) {
766 time_string = ctime(&s->last_login_time);
767 if (strchr(time_string, '\n'))
768 *strchr(time_string, '\n') = 0;
769 if (strcmp(s->hostname, "") == 0)
770 printf("Last login: %s\r\n", time_string);
772 printf("Last login: %s from %s\r\n", time_string,
780 * Display the message of the day.
788 if (options.print_motd) {
789 #ifdef HAVE_LOGIN_CAP
790 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
793 f = fopen("/etc/motd", "r");
796 while (fgets(buf, sizeof(buf), f))
805 * Check for quiet login, either .hushlogin or command given.
808 check_quietlogin(Session *s, const char *command)
811 struct passwd *pw = s->pw;
814 /* Return 1 if .hushlogin exists or a command given. */
817 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
818 #ifdef HAVE_LOGIN_CAP
819 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
822 if (stat(buf, &st) >= 0)
829 * Sets the value of the given variable in the environment. If the variable
830 * already exists, its value is overriden.
833 child_set_env(char ***envp, u_int *envsizep, const char *name,
840 * Find the slot where the value should be stored. If the variable
841 * already exists, we reuse the slot; otherwise we append a new slot
842 * at the end of the array, expanding if necessary.
845 namelen = strlen(name);
846 for (i = 0; env[i]; i++)
847 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
850 /* Reuse the slot. */
853 /* New variable. Expand if necessary. */
854 if (i >= (*envsizep) - 1) {
855 if (*envsizep >= 1000)
856 fatal("child_set_env: too many env vars,"
857 " skipping: %.100s", name);
859 env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
861 /* Need to set the NULL pointer at end of array beyond the new slot. */
865 /* Allocate space and format the variable in the appropriate slot. */
866 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
867 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
871 * Reads environment variables from the given file and adds/overrides them
872 * into the environment. If the file does not exist, this does nothing.
873 * Otherwise, it must consist of empty lines, comments (line starts with '#')
874 * and assignments of the form name=value. No other forms are allowed.
877 read_environment_file(char ***env, u_int *envsize,
878 const char *filename)
885 f = fopen(filename, "r");
889 while (fgets(buf, sizeof(buf), f)) {
891 fatal("Too many lines in environment file %s", filename);
892 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
894 if (!*cp || *cp == '#' || *cp == '\n')
896 if (strchr(cp, '\n'))
897 *strchr(cp, '\n') = '\0';
898 value = strchr(cp, '=');
900 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
905 * Replace the equals sign by nul, and advance value to
910 child_set_env(env, envsize, cp, value);
915 void copy_environment(char **source, char ***env, u_int *envsize)
917 char *var_name, *var_val;
923 for(i = 0; source[i] != NULL; i++) {
924 var_name = xstrdup(source[i]);
925 if ((var_val = strstr(var_name, "=")) == NULL) {
931 debug3("Copy environment: %s=%s", var_name, var_val);
932 child_set_env(env, envsize, var_name, var_val);
939 do_setup_env(Session *s, const char *shell)
944 struct passwd *pw = s->pw;
946 /* Initialize the environment. */
948 env = xmalloc(envsize * sizeof(char *));
953 * The Windows environment contains some setting which are
954 * important for a running system. They must not be dropped.
956 copy_environment(environ, &env, &envsize);
959 if (!options.use_login) {
960 /* Set basic environment. */
961 child_set_env(&env, &envsize, "USER", pw->pw_name);
962 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
963 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
964 #ifdef HAVE_LOGIN_CAP
965 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
966 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
968 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
969 #else /* HAVE_LOGIN_CAP */
972 * There's no standard path on Windows. The path contains
973 * important components pointing to the system directories,
974 * needed for loading shared libraries. So the path better
975 * remains intact here.
977 # ifdef SUPERUSER_PATH
978 child_set_env(&env, &envsize, "PATH",
979 s->pw->pw_uid == 0 ? SUPERUSER_PATH : _PATH_STDPATH);
981 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
982 # endif /* SUPERUSER_PATH */
983 # endif /* HAVE_CYGWIN */
984 #endif /* HAVE_LOGIN_CAP */
986 snprintf(buf, sizeof buf, "%.200s/%.50s",
987 _PATH_MAILDIR, pw->pw_name);
988 child_set_env(&env, &envsize, "MAIL", buf);
990 /* Normal systems set SHELL by default. */
991 child_set_env(&env, &envsize, "SHELL", shell);
994 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
996 /* Set custom environment options from RSA authentication. */
997 if (!options.use_login) {
998 while (custom_environment) {
999 struct envstring *ce = custom_environment;
1002 for (i = 0; str[i] != '=' && str[i]; i++)
1004 if (str[i] == '=') {
1006 child_set_env(&env, &envsize, str, str + i + 1);
1008 custom_environment = ce->next;
1014 snprintf(buf, sizeof buf, "%.50s %d %d",
1015 get_remote_ipaddr(), get_remote_port(), get_local_port());
1016 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1019 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1021 child_set_env(&env, &envsize, "TERM", s->term);
1023 child_set_env(&env, &envsize, "DISPLAY", s->display);
1024 if (original_command)
1025 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1032 if ((cp = getenv("AUTHSTATE")) != NULL)
1033 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1034 if ((cp = getenv("KRB5CCNAME")) != NULL)
1035 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1036 read_environment_file(&env, &envsize, "/etc/environment");
1040 if (s->authctxt->krb4_ticket_file)
1041 child_set_env(&env, &envsize, "KRBTKFILE",
1042 s->authctxt->krb4_ticket_file);
1045 if (s->authctxt->krb5_ticket_file)
1046 child_set_env(&env, &envsize, "KRB5CCNAME",
1047 s->authctxt->krb5_ticket_file);
1051 * Pull in any environment variables that may have
1057 p = fetch_pam_environment();
1058 copy_environment(p, &env, &envsize);
1059 free_pam_environment(p);
1061 #endif /* USE_PAM */
1063 if (auth_sock_name != NULL)
1064 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1067 /* read $HOME/.ssh/environment. */
1068 if (options.permit_user_env && !options.use_login) {
1069 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1071 read_environment_file(&env, &envsize, buf);
1074 /* dump the environment */
1075 fprintf(stderr, "Environment:\n");
1076 for (i = 0; env[i]; i++)
1077 fprintf(stderr, " %.200s\n", env[i]);
1083 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1084 * first in this order).
1087 do_rc_files(Session *s, const char *shell)
1095 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1097 /* ignore _PATH_SSH_USER_RC for subsystems */
1098 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1099 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1100 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1102 fprintf(stderr, "Running %s\n", cmd);
1103 f = popen(cmd, "w");
1106 fprintf(f, "%s %s\n", s->auth_proto,
1110 fprintf(stderr, "Could not run %s\n",
1112 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1114 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1115 _PATH_SSH_SYSTEM_RC);
1116 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1119 fprintf(f, "%s %s\n", s->auth_proto,
1123 fprintf(stderr, "Could not run %s\n",
1124 _PATH_SSH_SYSTEM_RC);
1125 } else if (do_xauth && options.xauth_location != NULL) {
1126 /* Add authority data to .Xauthority if appropriate. */
1129 "Running %.500s add "
1130 "%.100s %.100s %.100s\n",
1131 options.xauth_location, s->auth_display,
1132 s->auth_proto, s->auth_data);
1134 snprintf(cmd, sizeof cmd, "%s -q -",
1135 options.xauth_location);
1136 f = popen(cmd, "w");
1138 fprintf(f, "add %s %s %s\n",
1139 s->auth_display, s->auth_proto,
1143 fprintf(stderr, "Could not run %s\n",
1150 do_nologin(struct passwd *pw)
1155 #ifdef HAVE_LOGIN_CAP
1156 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1157 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1158 _PATH_NOLOGIN), "r");
1161 f = fopen(_PATH_NOLOGIN, "r");
1164 /* /etc/nologin exists. Print its contents and exit. */
1165 while (fgets(buf, sizeof(buf), f))
1172 /* Set login name, uid, gid, and groups. */
1174 do_setusercontext(struct passwd *pw)
1178 #else /* HAVE_CYGWIN */
1179 if (getuid() == 0 || geteuid() == 0) {
1180 #endif /* HAVE_CYGWIN */
1181 #ifdef HAVE_SETPCRED
1182 setpcred(pw->pw_name);
1183 #endif /* HAVE_SETPCRED */
1184 #ifdef HAVE_LOGIN_CAP
1188 if (setusercontext(lc, pw, pw->pw_uid,
1189 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1190 perror("unable to set user context");
1194 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1195 /* Sets login uid for accounting */
1196 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1197 error("setluid: %s", strerror(errno));
1198 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1200 if (setlogin(pw->pw_name) < 0)
1201 error("setlogin failed: %s", strerror(errno));
1202 if (setgid(pw->pw_gid) < 0) {
1206 /* Initialize the group list. */
1207 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1208 perror("initgroups");
1214 * PAM credentials may take the form of supplementary groups.
1215 * These will have been wiped by the above initgroups() call.
1216 * Reestablish them here.
1219 # endif /* USE_PAM */
1220 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1221 irix_setusercontext(pw);
1222 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1226 /* Permanently switch to the desired uid. */
1227 permanently_set_uid(pw);
1230 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1231 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1235 launch_login(struct passwd *pw, const char *hostname)
1237 /* Launch login(1). */
1239 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1240 #ifdef xxxLOGIN_NEEDS_TERM
1241 (s->term ? s->term : "unknown"),
1242 #endif /* LOGIN_NEEDS_TERM */
1243 #ifdef LOGIN_NO_ENDOPT
1244 "-p", "-f", pw->pw_name, (char *)NULL);
1246 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1249 /* Login couldn't be executed, die. */
1256 * Performs common processing for the child, such as setting up the
1257 * environment, closing extra file descriptors, setting the user and group
1258 * ids, and executing the command or shell.
1261 do_child(Session *s, const char *command)
1263 extern char **environ;
1266 const char *shell, *shell0, *hostname = NULL;
1267 struct passwd *pw = s->pw;
1270 /* remove hostkey from the child's memory */
1271 destroy_sensitive_data();
1273 /* login(1) is only called if we execute the login shell */
1274 if (options.use_login && command != NULL)
1275 options.use_login = 0;
1278 * Login(1) does this as well, and it needs uid 0 for the "-h"
1279 * switch, so we let login(1) to this for us.
1281 if (!options.use_login) {
1283 session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty);
1284 if (!check_quietlogin(s, command))
1286 #else /* HAVE_OSF_SIA */
1288 do_setusercontext(pw);
1289 #endif /* HAVE_OSF_SIA */
1293 * Get the shell from the password data. An empty shell field is
1294 * legal, and means /bin/sh.
1296 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1297 #ifdef HAVE_LOGIN_CAP
1298 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1301 env = do_setup_env(s, shell);
1303 /* we have to stash the hostname before we close our socket. */
1304 if (options.use_login)
1305 hostname = get_remote_name_or_ip(utmp_len,
1306 options.verify_reverse_mapping);
1308 * Close the connection descriptors; note that this is the child, and
1309 * the server will still have the socket open, and it is important
1310 * that we do not shutdown it. Note that the descriptors cannot be
1311 * closed before building the environment, as we call
1312 * get_remote_ipaddr there.
1314 if (packet_get_connection_in() == packet_get_connection_out())
1315 close(packet_get_connection_in());
1317 close(packet_get_connection_in());
1318 close(packet_get_connection_out());
1321 * Close all descriptors related to channels. They will still remain
1322 * open in the parent.
1324 /* XXX better use close-on-exec? -markus */
1325 channel_close_all();
1328 * Close any extra file descriptors. Note that there may still be
1329 * descriptors left by system functions. They will be closed later.
1334 * Close any extra open file descriptors so that we don\'t have them
1335 * hanging around in clients. Note that we want to do this after
1336 * initgroups, because at least on Solaris 2.3 it leaves file
1339 for (i = 3; i < 64; i++)
1343 * Must take new environment into use so that .ssh/rc,
1344 * /etc/ssh/sshrc and xauth are run in the proper environment.
1349 /* Try to get AFS tokens for the local cell. */
1353 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1354 krb_afslog(cell, 0);
1360 /* Change current directory to the user\'s home directory. */
1361 if (chdir(pw->pw_dir) < 0) {
1362 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1363 pw->pw_dir, strerror(errno));
1364 #ifdef HAVE_LOGIN_CAP
1365 if (login_getcapbool(lc, "requirehome", 0))
1370 if (!options.use_login)
1371 do_rc_files(s, shell);
1373 /* restore SIGPIPE for child */
1374 signal(SIGPIPE, SIG_DFL);
1376 if (options.use_login) {
1377 launch_login(pw, hostname);
1381 /* Get the last component of the shell name. */
1382 if ((shell0 = strrchr(shell, '/')) != NULL)
1388 * If we have no command, execute the shell. In this case, the shell
1389 * name to be passed in argv[0] is preceded by '-' to indicate that
1390 * this is a login shell.
1395 /* Start the shell. Set initial character to '-'. */
1398 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1399 >= sizeof(argv0) - 1) {
1405 /* Execute the shell. */
1408 execve(shell, argv, env);
1410 /* Executing the shell failed. */
1415 * Execute the command using the user's shell. This uses the -c
1416 * option to execute the command.
1418 argv[0] = (char *) shell0;
1420 argv[2] = (char *) command;
1422 execve(shell, argv, env);
1431 static int did_init = 0;
1433 debug("session_new: init");
1434 for (i = 0; i < MAX_SESSIONS; i++) {
1435 sessions[i].used = 0;
1439 for (i = 0; i < MAX_SESSIONS; i++) {
1440 Session *s = &sessions[i];
1442 memset(s, 0, sizeof(*s));
1448 debug("session_new: session %d", i);
1459 for (i = 0; i < MAX_SESSIONS; i++) {
1460 Session *s = &sessions[i];
1461 debug("dump: used %d session %d %p channel %d pid %ld",
1471 session_open(Authctxt *authctxt, int chanid)
1473 Session *s = session_new();
1474 debug("session_open: channel %d", chanid);
1476 error("no more sessions");
1479 s->authctxt = authctxt;
1480 s->pw = authctxt->pw;
1482 fatal("no user for session %d", s->self);
1483 debug("session_open: session %d: link with channel %d", s->self, chanid);
1489 session_by_tty(char *tty)
1492 for (i = 0; i < MAX_SESSIONS; i++) {
1493 Session *s = &sessions[i];
1494 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1495 debug("session_by_tty: session %d tty %s", i, tty);
1499 debug("session_by_tty: unknown tty %.100s", tty);
1505 session_by_channel(int id)
1508 for (i = 0; i < MAX_SESSIONS; i++) {
1509 Session *s = &sessions[i];
1510 if (s->used && s->chanid == id) {
1511 debug("session_by_channel: session %d channel %d", i, id);
1515 debug("session_by_channel: unknown channel %d", id);
1521 session_by_pid(pid_t pid)
1524 debug("session_by_pid: pid %ld", (long)pid);
1525 for (i = 0; i < MAX_SESSIONS; i++) {
1526 Session *s = &sessions[i];
1527 if (s->used && s->pid == pid)
1530 error("session_by_pid: unknown pid %ld", (long)pid);
1536 session_window_change_req(Session *s)
1538 s->col = packet_get_int();
1539 s->row = packet_get_int();
1540 s->xpixel = packet_get_int();
1541 s->ypixel = packet_get_int();
1543 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1548 session_pty_req(Session *s)
1554 debug("Allocating a pty not permitted for this authentication.");
1557 if (s->ttyfd != -1) {
1558 packet_disconnect("Protocol error: you already have a pty.");
1561 /* Get the time and hostname when the user last logged in. */
1562 if (options.print_lastlog) {
1563 s->hostname[0] = '\0';
1564 s->last_login_time = get_last_login_time(s->pw->pw_uid,
1565 s->pw->pw_name, s->hostname, sizeof(s->hostname));
1568 s->term = packet_get_string(&len);
1571 s->col = packet_get_int();
1572 s->row = packet_get_int();
1574 s->row = packet_get_int();
1575 s->col = packet_get_int();
1577 s->xpixel = packet_get_int();
1578 s->ypixel = packet_get_int();
1580 if (strcmp(s->term, "") == 0) {
1585 /* Allocate a pty and open it. */
1586 debug("Allocating pty.");
1587 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1593 error("session_pty_req: session %d alloc failed", s->self);
1596 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1598 /* for SSH1 the tty modes length is not given */
1600 n_bytes = packet_remaining();
1601 tty_parse_modes(s->ttyfd, &n_bytes);
1604 * Add a cleanup function to clear the utmp entry and record logout
1605 * time in case we call fatal() (e.g., the connection gets closed).
1607 fatal_add_cleanup(session_pty_cleanup, (void *)s);
1609 pty_setowner(s->pw, s->tty);
1611 /* Set window size from the packet. */
1612 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1615 session_proctitle(s);
1620 session_subsystem_req(Session *s)
1625 char *cmd, *subsys = packet_get_string(&len);
1629 log("subsystem request for %.100s", subsys);
1631 for (i = 0; i < options.num_subsystems; i++) {
1632 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1633 cmd = options.subsystem_command[i];
1634 if (stat(cmd, &st) < 0) {
1635 error("subsystem: cannot stat %s: %s", cmd,
1639 debug("subsystem: exec() %s", cmd);
1640 s->is_subsystem = 1;
1648 log("subsystem request for %.100s failed, subsystem not found",
1656 session_x11_req(Session *s)
1660 s->single_connection = packet_get_char();
1661 s->auth_proto = packet_get_string(NULL);
1662 s->auth_data = packet_get_string(NULL);
1663 s->screen = packet_get_int();
1666 success = session_setup_x11fwd(s);
1668 xfree(s->auth_proto);
1669 xfree(s->auth_data);
1670 s->auth_proto = NULL;
1671 s->auth_data = NULL;
1677 session_shell_req(Session *s)
1685 session_exec_req(Session *s)
1688 char *command = packet_get_string(&len);
1690 do_exec(s, command);
1696 session_auth_agent_req(Session *s)
1698 static int called = 0;
1700 if (no_agent_forwarding_flag) {
1701 debug("session_auth_agent_req: no_agent_forwarding_flag");
1708 return auth_input_request_forwarding(s->pw);
1713 session_input_channel_req(Channel *c, const char *rtype)
1718 if ((s = session_by_channel(c->self)) == NULL) {
1719 log("session_input_channel_req: no session %d req %.100s",
1723 debug("session_input_channel_req: session %d req %s", s->self, rtype);
1726 * a session is in LARVAL state until a shell, a command
1727 * or a subsystem is executed
1729 if (c->type == SSH_CHANNEL_LARVAL) {
1730 if (strcmp(rtype, "shell") == 0) {
1731 success = session_shell_req(s);
1732 } else if (strcmp(rtype, "exec") == 0) {
1733 success = session_exec_req(s);
1734 } else if (strcmp(rtype, "pty-req") == 0) {
1735 success = session_pty_req(s);
1736 } else if (strcmp(rtype, "x11-req") == 0) {
1737 success = session_x11_req(s);
1738 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1739 success = session_auth_agent_req(s);
1740 } else if (strcmp(rtype, "subsystem") == 0) {
1741 success = session_subsystem_req(s);
1744 if (strcmp(rtype, "window-change") == 0) {
1745 success = session_window_change_req(s);
1751 session_set_fds(Session *s, int fdin, int fdout, int fderr)
1754 fatal("session_set_fds: called for proto != 2.0");
1756 * now that have a child and a pipe to the child,
1757 * we can activate our channel and register the fd's
1759 if (s->chanid == -1)
1760 fatal("no channel for session %d", s->self);
1761 channel_set_fds(s->chanid,
1763 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1765 CHAN_SES_WINDOW_DEFAULT);
1769 * Function to perform pty cleanup. Also called if we get aborted abnormally
1770 * (e.g., due to a dropped connection).
1773 session_pty_cleanup2(void *session)
1775 Session *s = session;
1778 error("session_pty_cleanup: no session");
1784 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1786 /* Record that the user has logged out. */
1788 record_logout(s->pid, s->tty, s->pw->pw_name);
1790 /* Release the pseudo-tty. */
1792 pty_release(s->tty);
1795 * Close the server side of the socket pairs. We must do this after
1796 * the pty cleanup, so that another process doesn't get this pty
1797 * while we're still cleaning up.
1799 if (close(s->ptymaster) < 0)
1800 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
1802 /* unlink pty from session */
1807 session_pty_cleanup(void *session)
1809 PRIVSEP(session_pty_cleanup2(session));
1815 #define SSH_SIG(x) if (sig == SIG ## x) return #x
1830 return "SIG@openssh.com";
1834 session_exit_message(Session *s, int status)
1838 if ((c = channel_lookup(s->chanid)) == NULL)
1839 fatal("session_exit_message: session %d: no channel %d",
1840 s->self, s->chanid);
1841 debug("session_exit_message: session %d channel %d pid %ld",
1842 s->self, s->chanid, (long)s->pid);
1844 if (WIFEXITED(status)) {
1845 channel_request_start(s->chanid, "exit-status", 0);
1846 packet_put_int(WEXITSTATUS(status));
1848 } else if (WIFSIGNALED(status)) {
1849 channel_request_start(s->chanid, "exit-signal", 0);
1850 packet_put_cstring(sig2name(WTERMSIG(status)));
1852 packet_put_char(WCOREDUMP(status));
1853 #else /* WCOREDUMP */
1855 #endif /* WCOREDUMP */
1856 packet_put_cstring("");
1857 packet_put_cstring("");
1860 /* Some weird exit cause. Just exit. */
1861 packet_disconnect("wait returned status %04x.", status);
1864 /* disconnect channel */
1865 debug("session_exit_message: release channel %d", s->chanid);
1866 channel_cancel_cleanup(s->chanid);
1868 * emulate a write failure with 'chan_write_failed', nobody will be
1869 * interested in data we write.
1870 * Note that we must not call 'chan_read_failed', since there could
1871 * be some more data waiting in the pipe.
1873 if (c->ostate != CHAN_OUTPUT_CLOSED)
1874 chan_write_failed(c);
1879 session_close(Session *s)
1881 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
1882 if (s->ttyfd != -1) {
1883 fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1884 session_pty_cleanup(s);
1890 if (s->auth_display)
1891 xfree(s->auth_display);
1893 xfree(s->auth_data);
1895 xfree(s->auth_proto);
1897 session_proctitle(s);
1901 session_close_by_pid(pid_t pid, int status)
1903 Session *s = session_by_pid(pid);
1905 debug("session_close_by_pid: no session for pid %ld",
1909 if (s->chanid != -1)
1910 session_exit_message(s, status);
1915 * this is called when a channel dies before
1916 * the session 'child' itself dies
1919 session_close_by_channel(int id, void *arg)
1921 Session *s = session_by_channel(id);
1923 debug("session_close_by_channel: no session for id %d", id);
1926 debug("session_close_by_channel: channel %d child %ld",
1929 debug("session_close_by_channel: channel %d: has child", id);
1931 * delay detach of session, but release pty, since
1932 * the fd's to the child are already closed
1934 if (s->ttyfd != -1) {
1935 fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1936 session_pty_cleanup(s);
1940 /* detach by removing callback */
1941 channel_cancel_cleanup(s->chanid);
1947 session_destroy_all(void (*closefunc)(Session *))
1950 for (i = 0; i < MAX_SESSIONS; i++) {
1951 Session *s = &sessions[i];
1953 if (closefunc != NULL)
1962 session_tty_list(void)
1964 static char buf[1024];
1967 for (i = 0; i < MAX_SESSIONS; i++) {
1968 Session *s = &sessions[i];
1969 if (s->used && s->ttyfd != -1) {
1971 strlcat(buf, ",", sizeof buf);
1972 strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1976 strlcpy(buf, "notty", sizeof buf);
1981 session_proctitle(Session *s)
1984 error("no user for session %d", s->self);
1986 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1990 session_setup_x11fwd(Session *s)
1993 char display[512], auth_display[512];
1994 char hostname[MAXHOSTNAMELEN];
1996 if (no_x11_forwarding_flag) {
1997 packet_send_debug("X11 forwarding disabled in user configuration file.");
2000 if (!options.x11_forwarding) {
2001 debug("X11 forwarding disabled in server configuration file.");
2004 if (!options.xauth_location ||
2005 (stat(options.xauth_location, &st) == -1)) {
2006 packet_send_debug("No xauth program; cannot forward with spoofing.");
2009 if (options.use_login) {
2010 packet_send_debug("X11 forwarding disabled; "
2011 "not compatible with UseLogin=yes.");
2014 if (s->display != NULL) {
2015 debug("X11 display already set.");
2018 if (x11_create_display_inet(options.x11_display_offset,
2019 options.x11_use_localhost, s->single_connection,
2020 &s->display_number) == -1) {
2021 debug("x11_create_display_inet failed.");
2025 /* Set up a suitable value for the DISPLAY variable. */
2026 if (gethostname(hostname, sizeof(hostname)) < 0)
2027 fatal("gethostname: %.100s", strerror(errno));
2029 * auth_display must be used as the displayname when the
2030 * authorization entry is added with xauth(1). This will be
2031 * different than the DISPLAY string for localhost displays.
2033 if (options.x11_use_localhost) {
2034 snprintf(display, sizeof display, "localhost:%u.%u",
2035 s->display_number, s->screen);
2036 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2037 s->display_number, s->screen);
2038 s->display = xstrdup(display);
2039 s->auth_display = xstrdup(auth_display);
2041 #ifdef IPADDR_IN_DISPLAY
2043 struct in_addr my_addr;
2045 he = gethostbyname(hostname);
2047 error("Can't get IP address for X11 DISPLAY.");
2048 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2051 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2052 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2053 s->display_number, s->screen);
2055 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2056 s->display_number, s->screen);
2058 s->display = xstrdup(display);
2059 s->auth_display = xstrdup(display);
2066 do_authenticated2(Authctxt *authctxt)
2068 server_loop2(authctxt);