1 /* $OpenBSD: session.c,v 1.230 2008/02/22 05:58:56 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"
90 #include "monitor_wrap.h"
93 #if defined(KRB5) && defined(USE_AFS)
99 Session *session_new(void);
100 void session_set_fds(Session *, int, int, int);
101 void session_pty_cleanup(Session *);
102 void session_proctitle(Session *);
103 int session_setup_x11fwd(Session *);
104 void do_exec_pty(Session *, const char *);
105 void do_exec_no_pty(Session *, const char *);
106 void do_exec(Session *, const char *);
107 void do_login(Session *, const char *);
108 #ifdef LOGIN_NEEDS_UTMPX
109 static void do_pre_login(Session *s);
111 void do_child(Session *, const char *);
113 int check_quietlogin(Session *, const char *);
115 static void do_authenticated1(Authctxt *);
116 static void do_authenticated2(Authctxt *);
118 static int session_pty_req(Session *);
121 extern ServerOptions options;
122 extern char *__progname;
123 extern int log_stderr;
124 extern int debug_flag;
125 extern u_int utmp_len;
126 extern int startup_pipe;
127 extern void destroy_sensitive_data(void);
128 extern Buffer loginmsg;
130 /* original command from peer. */
131 const char *original_command = NULL;
134 #define MAX_SESSIONS 20
135 Session sessions[MAX_SESSIONS];
137 #define SUBSYSTEM_NONE 0
138 #define SUBSYSTEM_EXT 1
139 #define SUBSYSTEM_INT_SFTP 2
141 #ifdef HAVE_LOGIN_CAP
145 static int is_child = 0;
147 /* Name and directory of socket for authentication agent forwarding. */
148 static char *auth_sock_name = NULL;
149 static char *auth_sock_dir = NULL;
151 /* removes the agent forwarding socket */
154 auth_sock_cleanup_proc(struct passwd *pw)
156 if (auth_sock_name != NULL) {
157 temporarily_use_uid(pw);
158 unlink(auth_sock_name);
159 rmdir(auth_sock_dir);
160 auth_sock_name = NULL;
166 auth_input_request_forwarding(struct passwd * pw)
170 struct sockaddr_un sunaddr;
172 if (auth_sock_name != NULL) {
173 error("authentication forwarding requested twice.");
177 /* Temporarily drop privileged uid for mkdir/bind. */
178 temporarily_use_uid(pw);
180 /* Allocate a buffer for the socket name, and format the name. */
181 auth_sock_name = xmalloc(MAXPATHLEN);
182 auth_sock_dir = xmalloc(MAXPATHLEN);
183 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
185 /* Create private directory for socket */
186 if (mkdtemp(auth_sock_dir) == NULL) {
187 packet_send_debug("Agent forwarding disabled: "
188 "mkdtemp() failed: %.100s", strerror(errno));
190 xfree(auth_sock_name);
191 xfree(auth_sock_dir);
192 auth_sock_name = NULL;
193 auth_sock_dir = NULL;
196 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
197 auth_sock_dir, (long) getpid());
199 /* Create the socket. */
200 sock = socket(AF_UNIX, SOCK_STREAM, 0);
202 packet_disconnect("socket: %.100s", strerror(errno));
204 /* Bind it to the name. */
205 memset(&sunaddr, 0, sizeof(sunaddr));
206 sunaddr.sun_family = AF_UNIX;
207 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
209 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0)
210 packet_disconnect("bind: %.100s", strerror(errno));
212 /* Restore the privileged uid. */
215 /* Start listening on the socket. */
216 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
217 packet_disconnect("listen: %.100s", strerror(errno));
219 /* Allocate a channel for the authentication agent socket. */
220 nc = channel_new("auth socket",
221 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
222 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
223 0, "auth socket", 1);
224 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
229 display_loginmsg(void)
231 if (buffer_len(&loginmsg) > 0) {
232 buffer_append(&loginmsg, "\0", 1);
233 printf("%s", (char *)buffer_ptr(&loginmsg));
234 buffer_clear(&loginmsg);
239 do_authenticated(Authctxt *authctxt)
241 setproctitle("%s", authctxt->pw->pw_name);
243 /* setup the channel layer */
244 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
245 channel_permit_all_opens();
248 do_authenticated2(authctxt);
250 do_authenticated1(authctxt);
252 do_cleanup(authctxt);
256 * Prepares for an interactive session. This is called after the user has
257 * been successfully authenticated. During this message exchange, pseudo
258 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
259 * are requested, etc.
262 do_authenticated1(Authctxt *authctxt)
266 int success, type, screen_flag;
267 int enable_compression_after_reply = 0;
268 u_int proto_len, data_len, dlen, compression_level = 0;
272 error("no more sessions");
275 s->authctxt = authctxt;
276 s->pw = authctxt->pw;
279 * We stay in this loop until the client requests to execute a shell
285 /* Get a packet from the client. */
286 type = packet_read();
288 /* Process the packet. */
290 case SSH_CMSG_REQUEST_COMPRESSION:
291 compression_level = packet_get_int();
293 if (compression_level < 1 || compression_level > 9) {
294 packet_send_debug("Received invalid compression level %d.",
298 if (options.compression == COMP_NONE) {
299 debug2("compression disabled");
302 /* Enable compression after we have responded with SUCCESS. */
303 enable_compression_after_reply = 1;
307 case SSH_CMSG_REQUEST_PTY:
308 success = session_pty_req(s);
311 case SSH_CMSG_X11_REQUEST_FORWARDING:
312 s->auth_proto = packet_get_string(&proto_len);
313 s->auth_data = packet_get_string(&data_len);
315 screen_flag = packet_get_protocol_flags() &
316 SSH_PROTOFLAG_SCREEN_NUMBER;
317 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
319 if (packet_remaining() == 4) {
321 debug2("Buggy client: "
322 "X11 screen flag missing");
323 s->screen = packet_get_int();
328 success = session_setup_x11fwd(s);
330 xfree(s->auth_proto);
332 s->auth_proto = NULL;
337 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
338 if (no_agent_forwarding_flag || compat13) {
339 debug("Authentication agent forwarding not permitted for this authentication.");
342 debug("Received authentication agent forwarding request.");
343 success = auth_input_request_forwarding(s->pw);
346 case SSH_CMSG_PORT_FORWARD_REQUEST:
347 if (no_port_forwarding_flag) {
348 debug("Port forwarding not permitted for this authentication.");
351 if (!options.allow_tcp_forwarding) {
352 debug("Port forwarding not permitted.");
355 debug("Received TCP/IP port forwarding request.");
356 if (channel_input_port_forward_request(s->pw->pw_uid == 0,
357 options.gateway_ports) < 0) {
358 debug("Port forwarding failed.");
364 case SSH_CMSG_MAX_PACKET_SIZE:
365 if (packet_set_maxsize(packet_get_int()) > 0)
369 case SSH_CMSG_EXEC_SHELL:
370 case SSH_CMSG_EXEC_CMD:
371 if (type == SSH_CMSG_EXEC_CMD) {
372 command = packet_get_string(&dlen);
373 debug("Exec command '%.500s'", command);
385 * Any unknown messages in this phase are ignored,
386 * and a failure message is returned.
388 logit("Unknown packet type received after authentication: %d", type);
390 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
394 /* Enable compression now that we have replied if appropriate. */
395 if (enable_compression_after_reply) {
396 enable_compression_after_reply = 0;
397 packet_start_compression(compression_level);
403 * This is called to fork and execute a command when we have no tty. This
404 * will call do_child from the child, and server_loop from the parent after
405 * setting up file descriptors and such.
408 do_exec_no_pty(Session *s, const char *command)
413 int pin[2], pout[2], perr[2];
414 /* Allocate pipes for communicating with the program. */
415 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
416 packet_disconnect("Could not create pipes: %.100s",
418 #else /* USE_PIPES */
419 int inout[2], err[2];
420 /* Uses socket pairs to communicate with the program. */
421 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
422 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
423 packet_disconnect("Could not create socket pairs: %.100s",
425 #endif /* USE_PIPES */
427 fatal("do_exec_no_pty: no session");
429 session_proctitle(s);
432 if (options.use_pam && !use_privsep)
436 /* Fork the child. */
437 if ((pid = fork()) == 0) {
440 /* Child. Reinitialize the log since the pid has changed. */
441 log_init(__progname, options.log_level, options.log_facility, log_stderr);
444 * Create a new session and process group since the 4.4BSD
445 * setlogin() affects the entire process group.
448 error("setsid failed: %.100s", strerror(errno));
452 * Redirect stdin. We close the parent side of the socket
453 * pair, and make the child side the standard input.
456 if (dup2(pin[0], 0) < 0)
457 perror("dup2 stdin");
460 /* Redirect stdout. */
462 if (dup2(pout[1], 1) < 0)
463 perror("dup2 stdout");
466 /* Redirect stderr. */
468 if (dup2(perr[1], 2) < 0)
469 perror("dup2 stderr");
471 #else /* USE_PIPES */
473 * Redirect stdin, stdout, and stderr. Stdin and stdout will
474 * use the same socket, as some programs (particularly rdist)
475 * seem to depend on it.
479 if (dup2(inout[0], 0) < 0) /* stdin */
480 perror("dup2 stdin");
481 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
482 perror("dup2 stdout");
483 if (dup2(err[0], 2) < 0) /* stderr */
484 perror("dup2 stderr");
485 #endif /* USE_PIPES */
488 cray_init_job(s->pw); /* set up cray jid and tmpdir */
491 /* Do processing for the child (exec command etc). */
492 do_child(s, command);
496 signal(WJSIGNAL, cray_job_termination_handler);
500 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
503 packet_disconnect("fork failed: %.100s", strerror(errno));
505 /* Set interactive/non-interactive mode. */
506 packet_set_interactive(s->display != NULL);
508 /* We are the parent. Close the child sides of the pipes. */
514 if (s->is_subsystem) {
518 session_set_fds(s, pin[1], pout[0], perr[0]);
520 /* Enter the interactive session. */
521 server_loop(pid, pin[1], pout[0], perr[0]);
522 /* server_loop has closed pin[1], pout[0], and perr[0]. */
524 #else /* USE_PIPES */
525 /* We are the parent. Close the child sides of the socket pairs. */
530 * Clear loginmsg, since it's the child's responsibility to display
531 * it to the user, otherwise multiple sessions may accumulate
532 * multiple copies of the login messages.
534 buffer_clear(&loginmsg);
537 * Enter the interactive session. Note: server_loop must be able to
538 * handle the case that fdin and fdout are the same.
541 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
543 server_loop(pid, inout[1], inout[1], err[1]);
544 /* server_loop has closed inout[1] and err[1]. */
546 #endif /* USE_PIPES */
550 * This is called to fork and execute a command when we have a tty. This
551 * will call do_child from the child, and server_loop from the parent after
552 * setting up file descriptors, controlling tty, updating wtmp, utmp,
553 * lastlog, and other such operations.
556 do_exec_pty(Session *s, const char *command)
558 int fdout, ptyfd, ttyfd, ptymaster;
562 fatal("do_exec_pty: no session");
567 if (options.use_pam) {
568 do_pam_set_tty(s->tty);
574 /* Fork the child. */
575 if ((pid = fork()) == 0) {
578 /* Child. Reinitialize the log because the pid has changed. */
579 log_init(__progname, options.log_level, options.log_facility, log_stderr);
580 /* Close the master side of the pseudo tty. */
583 /* Make the pseudo tty our controlling tty. */
584 pty_make_controlling_tty(&ttyfd, s->tty);
586 /* Redirect stdin/stdout/stderr from the pseudo tty. */
587 if (dup2(ttyfd, 0) < 0)
588 error("dup2 stdin: %s", strerror(errno));
589 if (dup2(ttyfd, 1) < 0)
590 error("dup2 stdout: %s", strerror(errno));
591 if (dup2(ttyfd, 2) < 0)
592 error("dup2 stderr: %s", strerror(errno));
594 /* Close the extra descriptor for the pseudo tty. */
597 /* record login, etc. similar to login(1) */
599 if (!(options.use_login && command == NULL)) {
601 cray_init_job(s->pw); /* set up cray jid and tmpdir */
603 do_login(s, command);
605 # ifdef LOGIN_NEEDS_UTMPX
611 /* Do common processing for the child, such as execing the command. */
612 do_child(s, command);
616 signal(WJSIGNAL, cray_job_termination_handler);
620 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
623 packet_disconnect("fork failed: %.100s", strerror(errno));
626 /* Parent. Close the slave side of the pseudo tty. */
630 * Create another descriptor of the pty master side for use as the
631 * standard input. We could use the original descriptor, but this
632 * simplifies code in server_loop. The descriptor is bidirectional.
636 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
638 /* we keep a reference to the pty master */
639 ptymaster = dup(ptyfd);
641 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
642 s->ptymaster = ptymaster;
644 /* Enter interactive session. */
645 packet_set_interactive(1);
647 session_set_fds(s, ptyfd, fdout, -1);
649 server_loop(pid, ptyfd, fdout, -1);
650 /* server_loop _has_ closed ptyfd and fdout. */
654 #ifdef LOGIN_NEEDS_UTMPX
656 do_pre_login(Session *s)
659 struct sockaddr_storage from;
660 pid_t pid = getpid();
663 * Get IP address of client. If the connection is not a socket, let
664 * the address be 0.0.0.0.
666 memset(&from, 0, sizeof(from));
667 fromlen = sizeof(from);
668 if (packet_connection_is_on_socket()) {
669 if (getpeername(packet_get_connection_in(),
670 (struct sockaddr *)&from, &fromlen) < 0) {
671 debug("getpeername: %.100s", strerror(errno));
676 record_utmp_only(pid, s->tty, s->pw->pw_name,
677 get_remote_name_or_ip(utmp_len, options.use_dns),
678 (struct sockaddr *)&from, fromlen);
683 * This is called to fork and execute a command. If another command is
684 * to be forced, execute that instead.
687 do_exec(Session *s, const char *command)
689 if (options.adm_forced_command) {
690 original_command = command;
691 command = options.adm_forced_command;
692 if (strcmp(INTERNAL_SFTP_NAME, command) == 0)
693 s->is_subsystem = SUBSYSTEM_INT_SFTP;
694 else if (s->is_subsystem)
695 s->is_subsystem = SUBSYSTEM_EXT;
696 debug("Forced command (config) '%.900s'", command);
697 } else if (forced_command) {
698 original_command = command;
699 command = forced_command;
700 if (strcmp(INTERNAL_SFTP_NAME, command) == 0)
701 s->is_subsystem = SUBSYSTEM_INT_SFTP;
702 else if (s->is_subsystem)
703 s->is_subsystem = SUBSYSTEM_EXT;
704 debug("Forced command (key option) '%.900s'", command);
707 #ifdef SSH_AUDIT_EVENTS
709 PRIVSEP(audit_run_command(command));
710 else if (s->ttyfd == -1) {
711 char *shell = s->pw->pw_shell;
713 if (shell[0] == '\0') /* empty shell means /bin/sh */
715 PRIVSEP(audit_run_command(shell));
719 do_exec_pty(s, command);
721 do_exec_no_pty(s, command);
723 original_command = NULL;
726 * Clear loginmsg: it's the child's responsibility to display
727 * it to the user, otherwise multiple sessions may accumulate
728 * multiple copies of the login messages.
730 buffer_clear(&loginmsg);
733 /* administrative, login(1)-like work */
735 do_login(Session *s, const char *command)
738 struct sockaddr_storage from;
739 struct passwd * pw = s->pw;
740 pid_t pid = getpid();
743 * Get IP address of client. If the connection is not a socket, let
744 * the address be 0.0.0.0.
746 memset(&from, 0, sizeof(from));
747 fromlen = sizeof(from);
748 if (packet_connection_is_on_socket()) {
749 if (getpeername(packet_get_connection_in(),
750 (struct sockaddr *) & from, &fromlen) < 0) {
751 debug("getpeername: %.100s", strerror(errno));
756 /* Record that there was a login on that tty from the remote host. */
758 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
759 get_remote_name_or_ip(utmp_len,
761 (struct sockaddr *)&from, fromlen);
765 * If password change is needed, do it now.
766 * This needs to occur before the ~/.hushlogin check.
768 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
771 s->authctxt->force_pwchange = 0;
772 /* XXX - signal [net] parent to enable forwardings */
776 if (check_quietlogin(s, command))
785 * Display the message of the day.
793 if (options.print_motd) {
794 #ifdef HAVE_LOGIN_CAP
795 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
798 f = fopen("/etc/motd", "r");
801 while (fgets(buf, sizeof(buf), f))
810 * Check for quiet login, either .hushlogin or command given.
813 check_quietlogin(Session *s, const char *command)
816 struct passwd *pw = s->pw;
819 /* Return 1 if .hushlogin exists or a command given. */
822 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
823 #ifdef HAVE_LOGIN_CAP
824 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
827 if (stat(buf, &st) >= 0)
834 * Sets the value of the given variable in the environment. If the variable
835 * already exists, its value is overriden.
838 child_set_env(char ***envp, u_int *envsizep, const char *name,
846 * If we're passed an uninitialized list, allocate a single null
847 * entry before continuing.
849 if (*envp == NULL && *envsizep == 0) {
850 *envp = xmalloc(sizeof(char *));
856 * Find the slot where the value should be stored. If the variable
857 * already exists, we reuse the slot; otherwise we append a new slot
858 * at the end of the array, expanding if necessary.
861 namelen = strlen(name);
862 for (i = 0; env[i]; i++)
863 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
866 /* Reuse the slot. */
869 /* New variable. Expand if necessary. */
871 if (i >= envsize - 1) {
873 fatal("child_set_env: too many env vars");
875 env = (*envp) = xrealloc(env, envsize, sizeof(char *));
878 /* Need to set the NULL pointer at end of array beyond the new slot. */
882 /* Allocate space and format the variable in the appropriate slot. */
883 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
884 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
888 * Reads environment variables from the given file and adds/overrides them
889 * into the environment. If the file does not exist, this does nothing.
890 * Otherwise, it must consist of empty lines, comments (line starts with '#')
891 * and assignments of the form name=value. No other forms are allowed.
894 read_environment_file(char ***env, u_int *envsize,
895 const char *filename)
902 f = fopen(filename, "r");
906 while (fgets(buf, sizeof(buf), f)) {
908 fatal("Too many lines in environment file %s", filename);
909 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
911 if (!*cp || *cp == '#' || *cp == '\n')
914 cp[strcspn(cp, "\n")] = '\0';
916 value = strchr(cp, '=');
918 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
923 * Replace the equals sign by nul, and advance value to
928 child_set_env(env, envsize, cp, value);
933 #ifdef HAVE_ETC_DEFAULT_LOGIN
935 * Return named variable from specified environment, or NULL if not present.
938 child_get_env(char **env, const char *name)
944 for (i=0; env[i] != NULL; i++)
945 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
946 return(env[i] + len + 1);
951 * Read /etc/default/login.
952 * We pick up the PATH (or SUPATH for root) and UMASK.
955 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
957 char **tmpenv = NULL, *var;
958 u_int i, tmpenvsize = 0;
962 * We don't want to copy the whole file to the child's environment,
963 * so we use a temporary environment and copy the variables we're
966 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
972 var = child_get_env(tmpenv, "SUPATH");
974 var = child_get_env(tmpenv, "PATH");
976 child_set_env(env, envsize, "PATH", var);
978 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
979 if (sscanf(var, "%5lo", &mask) == 1)
982 for (i = 0; tmpenv[i] != NULL; i++)
986 #endif /* HAVE_ETC_DEFAULT_LOGIN */
989 copy_environment(char **source, char ***env, u_int *envsize)
991 char *var_name, *var_val;
997 for(i = 0; source[i] != NULL; i++) {
998 var_name = xstrdup(source[i]);
999 if ((var_val = strstr(var_name, "=")) == NULL) {
1005 debug3("Copy environment: %s=%s", var_name, var_val);
1006 child_set_env(env, envsize, var_name, var_val);
1013 do_setup_env(Session *s, const char *shell)
1018 struct passwd *pw = s->pw;
1019 #ifndef HAVE_LOGIN_CAP
1023 /* Initialize the environment. */
1025 env = xcalloc(envsize, sizeof(char *));
1030 * The Windows environment contains some setting which are
1031 * important for a running system. They must not be dropped.
1036 p = fetch_windows_environment();
1037 copy_environment(p, &env, &envsize);
1038 free_windows_environment(p);
1043 /* Allow any GSSAPI methods that we've used to alter
1044 * the childs environment as they see fit
1046 ssh_gssapi_do_child(&env, &envsize);
1049 if (!options.use_login) {
1050 /* Set basic environment. */
1051 for (i = 0; i < s->num_env; i++)
1052 child_set_env(&env, &envsize, s->env[i].name,
1055 child_set_env(&env, &envsize, "USER", pw->pw_name);
1056 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1058 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1060 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1061 #ifdef HAVE_LOGIN_CAP
1062 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1063 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1065 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1066 #else /* HAVE_LOGIN_CAP */
1067 # ifndef HAVE_CYGWIN
1069 * There's no standard path on Windows. The path contains
1070 * important components pointing to the system directories,
1071 * needed for loading shared libraries. So the path better
1072 * remains intact here.
1074 # ifdef HAVE_ETC_DEFAULT_LOGIN
1075 read_etc_default_login(&env, &envsize, pw->pw_uid);
1076 path = child_get_env(env, "PATH");
1077 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1078 if (path == NULL || *path == '\0') {
1079 child_set_env(&env, &envsize, "PATH",
1080 s->pw->pw_uid == 0 ?
1081 SUPERUSER_PATH : _PATH_STDPATH);
1083 # endif /* HAVE_CYGWIN */
1084 #endif /* HAVE_LOGIN_CAP */
1086 snprintf(buf, sizeof buf, "%.200s/%.50s",
1087 _PATH_MAILDIR, pw->pw_name);
1088 child_set_env(&env, &envsize, "MAIL", buf);
1090 /* Normal systems set SHELL by default. */
1091 child_set_env(&env, &envsize, "SHELL", shell);
1094 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1096 /* Set custom environment options from RSA authentication. */
1097 if (!options.use_login) {
1098 while (custom_environment) {
1099 struct envstring *ce = custom_environment;
1102 for (i = 0; str[i] != '=' && str[i]; i++)
1104 if (str[i] == '=') {
1106 child_set_env(&env, &envsize, str, str + i + 1);
1108 custom_environment = ce->next;
1114 /* SSH_CLIENT deprecated */
1115 snprintf(buf, sizeof buf, "%.50s %d %d",
1116 get_remote_ipaddr(), get_remote_port(), get_local_port());
1117 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1119 laddr = get_local_ipaddr(packet_get_connection_in());
1120 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1121 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1123 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1126 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1128 child_set_env(&env, &envsize, "TERM", s->term);
1130 child_set_env(&env, &envsize, "DISPLAY", s->display);
1131 if (original_command)
1132 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1136 if (cray_tmpdir[0] != '\0')
1137 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1138 #endif /* _UNICOS */
1141 * Since we clear KRB5CCNAME at startup, if it's set now then it
1142 * must have been set by a native authentication method (eg AIX or
1143 * SIA), so copy it to the child.
1148 if ((cp = getenv("KRB5CCNAME")) != NULL)
1149 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1156 if ((cp = getenv("AUTHSTATE")) != NULL)
1157 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1158 read_environment_file(&env, &envsize, "/etc/environment");
1162 if (s->authctxt->krb5_ccname)
1163 child_set_env(&env, &envsize, "KRB5CCNAME",
1164 s->authctxt->krb5_ccname);
1168 * Pull in any environment variables that may have
1171 if (options.use_pam) {
1174 p = fetch_pam_child_environment();
1175 copy_environment(p, &env, &envsize);
1176 free_pam_environment(p);
1178 p = fetch_pam_environment();
1179 copy_environment(p, &env, &envsize);
1180 free_pam_environment(p);
1182 #endif /* USE_PAM */
1184 if (auth_sock_name != NULL)
1185 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1188 /* read $HOME/.ssh/environment. */
1189 if (options.permit_user_env && !options.use_login) {
1190 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1191 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1192 read_environment_file(&env, &envsize, buf);
1195 /* dump the environment */
1196 fprintf(stderr, "Environment:\n");
1197 for (i = 0; env[i]; i++)
1198 fprintf(stderr, " %.200s\n", env[i]);
1204 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1205 * first in this order).
1208 do_rc_files(Session *s, const char *shell)
1216 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1218 /* ignore _PATH_SSH_USER_RC for subsystems */
1219 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1220 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1221 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1223 fprintf(stderr, "Running %s\n", cmd);
1224 f = popen(cmd, "w");
1227 fprintf(f, "%s %s\n", s->auth_proto,
1231 fprintf(stderr, "Could not run %s\n",
1233 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1235 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1236 _PATH_SSH_SYSTEM_RC);
1237 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1240 fprintf(f, "%s %s\n", s->auth_proto,
1244 fprintf(stderr, "Could not run %s\n",
1245 _PATH_SSH_SYSTEM_RC);
1246 } else if (do_xauth && options.xauth_location != NULL) {
1247 /* Add authority data to .Xauthority if appropriate. */
1250 "Running %.500s remove %.100s\n",
1251 options.xauth_location, s->auth_display);
1253 "%.500s add %.100s %.100s %.100s\n",
1254 options.xauth_location, s->auth_display,
1255 s->auth_proto, s->auth_data);
1257 snprintf(cmd, sizeof cmd, "%s -q -",
1258 options.xauth_location);
1259 f = popen(cmd, "w");
1261 fprintf(f, "remove %s\n",
1263 fprintf(f, "add %s %s %s\n",
1264 s->auth_display, s->auth_proto,
1268 fprintf(stderr, "Could not run %s\n",
1275 do_nologin(struct passwd *pw)
1280 #ifdef HAVE_LOGIN_CAP
1281 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1282 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1283 _PATH_NOLOGIN), "r");
1286 f = fopen(_PATH_NOLOGIN, "r");
1289 /* /etc/nologin exists. Print its contents and exit. */
1290 logit("User %.100s not allowed because %s exists",
1291 pw->pw_name, _PATH_NOLOGIN);
1292 while (fgets(buf, sizeof(buf), f))
1301 * Chroot into a directory after checking it for safety: all path components
1302 * must be root-owned directories with strict permissions.
1305 safely_chroot(const char *path, uid_t uid)
1308 char component[MAXPATHLEN];
1312 fatal("chroot path does not begin at root");
1313 if (strlen(path) >= sizeof(component))
1314 fatal("chroot path too long");
1317 * Descend the path, checking that each component is a
1318 * root-owned directory with strict permissions.
1320 for (cp = path; cp != NULL;) {
1321 if ((cp = strchr(cp, '/')) == NULL)
1322 strlcpy(component, path, sizeof(component));
1325 memcpy(component, path, cp - path);
1326 component[cp - path] = '\0';
1329 debug3("%s: checking '%s'", __func__, component);
1331 if (stat(component, &st) != 0)
1332 fatal("%s: stat(\"%s\"): %s", __func__,
1333 component, strerror(errno));
1334 if (st.st_uid != 0 || (st.st_mode & 022) != 0)
1335 fatal("bad ownership or modes for chroot "
1336 "directory %s\"%s\"",
1337 cp == NULL ? "" : "component ", component);
1338 if (!S_ISDIR(st.st_mode))
1339 fatal("chroot path %s\"%s\" is not a directory",
1340 cp == NULL ? "" : "component ", component);
1344 closefrom(STDERR_FILENO + 1);
1346 if (chdir(path) == -1)
1347 fatal("Unable to chdir to chroot path \"%s\": "
1348 "%s", path, strerror(errno));
1349 if (chroot(path) == -1)
1350 fatal("chroot(\"%s\"): %s", path, strerror(errno));
1351 if (chdir("/") == -1)
1352 fatal("%s: chdir(/) after chroot: %s",
1353 __func__, strerror(errno));
1354 verbose("Changed root directory to \"%s\"", path);
1357 /* Set login name, uid, gid, and groups. */
1359 do_setusercontext(struct passwd *pw)
1361 char *chroot_path, *tmp;
1364 if (getuid() == 0 || geteuid() == 0)
1365 #endif /* HAVE_CYGWIN */
1368 #ifdef HAVE_SETPCRED
1369 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1370 fatal("Failed to set process credentials");
1371 #endif /* HAVE_SETPCRED */
1372 #ifdef HAVE_LOGIN_CAP
1377 if (options.gss_authentication) {
1378 temporarily_use_uid(pw);
1379 ssh_gssapi_storecreds();
1384 if (options.use_pam) {
1386 do_pam_setcred(use_privsep);
1388 # endif /* USE_PAM */
1389 if (setusercontext(lc, pw, pw->pw_uid,
1390 (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1391 perror("unable to set user context");
1395 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1396 /* Sets login uid for accounting */
1397 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1398 error("setluid: %s", strerror(errno));
1399 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1401 if (setlogin(pw->pw_name) < 0)
1402 error("setlogin failed: %s", strerror(errno));
1403 if (setgid(pw->pw_gid) < 0) {
1407 /* Initialize the group list. */
1408 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1409 perror("initgroups");
1414 if (options.gss_authentication) {
1415 temporarily_use_uid(pw);
1416 ssh_gssapi_storecreds();
1422 * PAM credentials may take the form of supplementary groups.
1423 * These will have been wiped by the above initgroups() call.
1424 * Reestablish them here.
1426 if (options.use_pam) {
1428 do_pam_setcred(use_privsep);
1430 # endif /* USE_PAM */
1431 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1432 irix_setusercontext(pw);
1433 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1438 if (set_id(pw->pw_name) != 0) {
1441 # endif /* USE_LIBIAF */
1444 if (options.chroot_directory != NULL &&
1445 strcasecmp(options.chroot_directory, "none") != 0) {
1446 tmp = tilde_expand_filename(options.chroot_directory,
1448 chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1449 "u", pw->pw_name, (char *)NULL);
1450 safely_chroot(chroot_path, pw->pw_uid);
1455 #ifdef HAVE_LOGIN_CAP
1456 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
1457 perror("unable to set user context (setuser)");
1461 /* Permanently switch to the desired uid. */
1462 permanently_set_uid(pw);
1469 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1470 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1473 ssh_selinux_setup_exec_context(pw->pw_name);
1478 do_pwchange(Session *s)
1481 fprintf(stderr, "WARNING: Your password has expired.\n");
1482 if (s->ttyfd != -1) {
1484 "You must change your password now and login again!\n");
1485 #ifdef PASSWD_NEEDS_USERNAME
1486 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1489 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1494 "Password change required but no TTY available.\n");
1500 launch_login(struct passwd *pw, const char *hostname)
1502 /* Launch login(1). */
1504 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1505 #ifdef xxxLOGIN_NEEDS_TERM
1506 (s->term ? s->term : "unknown"),
1507 #endif /* LOGIN_NEEDS_TERM */
1508 #ifdef LOGIN_NO_ENDOPT
1509 "-p", "-f", pw->pw_name, (char *)NULL);
1511 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1514 /* Login couldn't be executed, die. */
1521 child_close_fds(void)
1525 if (packet_get_connection_in() == packet_get_connection_out())
1526 close(packet_get_connection_in());
1528 close(packet_get_connection_in());
1529 close(packet_get_connection_out());
1532 * Close all descriptors related to channels. They will still remain
1533 * open in the parent.
1535 /* XXX better use close-on-exec? -markus */
1536 channel_close_all();
1539 * Close any extra file descriptors. Note that there may still be
1540 * descriptors left by system functions. They will be closed later.
1545 * Close any extra open file descriptors so that we don't have them
1546 * hanging around in clients. Note that we want to do this after
1547 * initgroups, because at least on Solaris 2.3 it leaves file
1550 for (i = 3; i < 64; i++)
1555 * Performs common processing for the child, such as setting up the
1556 * environment, closing extra file descriptors, setting the user and group
1557 * ids, and executing the command or shell.
1561 do_child(Session *s, const char *command)
1563 extern char **environ;
1565 char *argv[ARGV_MAX];
1566 const char *shell, *shell0, *hostname = NULL;
1567 struct passwd *pw = s->pw;
1569 /* remove hostkey from the child's memory */
1570 destroy_sensitive_data();
1572 /* Force a password change */
1573 if (s->authctxt->force_pwchange) {
1574 do_setusercontext(pw);
1580 /* login(1) is only called if we execute the login shell */
1581 if (options.use_login && command != NULL)
1582 options.use_login = 0;
1585 cray_setup(pw->pw_uid, pw->pw_name, command);
1586 #endif /* _UNICOS */
1589 * Login(1) does this as well, and it needs uid 0 for the "-h"
1590 * switch, so we let login(1) to this for us.
1592 if (!options.use_login) {
1594 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1595 if (!check_quietlogin(s, command))
1597 #else /* HAVE_OSF_SIA */
1598 /* When PAM is enabled we rely on it to do the nologin check */
1599 if (!options.use_pam)
1601 do_setusercontext(pw);
1603 * PAM session modules in do_setusercontext may have
1604 * generated messages, so if this in an interactive
1605 * login then display them too.
1607 if (!check_quietlogin(s, command))
1609 #endif /* HAVE_OSF_SIA */
1613 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1614 debug3("PAM session not opened, exiting");
1621 * Get the shell from the password data. An empty shell field is
1622 * legal, and means /bin/sh.
1624 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1627 * Make sure $SHELL points to the shell from the password file,
1628 * even if shell is overridden from login.conf
1630 env = do_setup_env(s, shell);
1632 #ifdef HAVE_LOGIN_CAP
1633 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1636 /* we have to stash the hostname before we close our socket. */
1637 if (options.use_login)
1638 hostname = get_remote_name_or_ip(utmp_len,
1641 * Close the connection descriptors; note that this is the child, and
1642 * the server will still have the socket open, and it is important
1643 * that we do not shutdown it. Note that the descriptors cannot be
1644 * closed before building the environment, as we call
1645 * get_remote_ipaddr there.
1650 * Must take new environment into use so that .ssh/rc,
1651 * /etc/ssh/sshrc and xauth are run in the proper environment.
1655 #if defined(KRB5) && defined(USE_AFS)
1657 * At this point, we check to see if AFS is active and if we have
1658 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1659 * if we can (and need to) extend the ticket into an AFS token. If
1660 * we don't do this, we run into potential problems if the user's
1661 * home directory is in AFS and it's not world-readable.
1664 if (options.kerberos_get_afs_token && k_hasafs() &&
1665 (s->authctxt->krb5_ctx != NULL)) {
1668 debug("Getting AFS token");
1672 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1673 krb5_afslog(s->authctxt->krb5_ctx,
1674 s->authctxt->krb5_fwd_ccache, cell, NULL);
1676 krb5_afslog_home(s->authctxt->krb5_ctx,
1677 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1681 /* Change current directory to the user's home directory. */
1682 if (chdir(pw->pw_dir) < 0) {
1683 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1684 pw->pw_dir, strerror(errno));
1685 #ifdef HAVE_LOGIN_CAP
1686 if (login_getcapbool(lc, "requirehome", 0))
1691 if (!options.use_login)
1692 do_rc_files(s, shell);
1694 /* restore SIGPIPE for child */
1695 signal(SIGPIPE, SIG_DFL);
1697 if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1698 extern int optind, optreset;
1702 setproctitle("%s@internal-sftp-server", s->pw->pw_name);
1703 args = strdup(command ? command : "sftp-server");
1704 for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1705 if (i < ARGV_MAX - 1)
1708 optind = optreset = 1;
1709 __progname = argv[0];
1710 exit(sftp_server_main(i, argv, s->pw));
1713 if (options.use_login) {
1714 launch_login(pw, hostname);
1718 /* Get the last component of the shell name. */
1719 if ((shell0 = strrchr(shell, '/')) != NULL)
1725 * If we have no command, execute the shell. In this case, the shell
1726 * name to be passed in argv[0] is preceded by '-' to indicate that
1727 * this is a login shell.
1732 /* Start the shell. Set initial character to '-'. */
1735 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1736 >= sizeof(argv0) - 1) {
1742 /* Execute the shell. */
1745 execve(shell, argv, env);
1747 /* Executing the shell failed. */
1752 * Execute the command using the user's shell. This uses the -c
1753 * option to execute the command.
1755 argv[0] = (char *) shell0;
1757 argv[2] = (char *) command;
1759 execve(shell, argv, env);
1768 static int did_init = 0;
1770 debug("session_new: init");
1771 for (i = 0; i < MAX_SESSIONS; i++) {
1772 sessions[i].used = 0;
1776 for (i = 0; i < MAX_SESSIONS; i++) {
1777 Session *s = &sessions[i];
1779 memset(s, 0, sizeof(*s));
1785 s->x11_chanids = NULL;
1786 debug("session_new: session %d", i);
1797 for (i = 0; i < MAX_SESSIONS; i++) {
1798 Session *s = &sessions[i];
1799 debug("dump: used %d session %d %p channel %d pid %ld",
1809 session_open(Authctxt *authctxt, int chanid)
1811 Session *s = session_new();
1812 debug("session_open: channel %d", chanid);
1814 error("no more sessions");
1817 s->authctxt = authctxt;
1818 s->pw = authctxt->pw;
1819 if (s->pw == NULL || !authctxt->valid)
1820 fatal("no user for session %d", s->self);
1821 debug("session_open: session %d: link with channel %d", s->self, chanid);
1827 session_by_tty(char *tty)
1830 for (i = 0; i < MAX_SESSIONS; i++) {
1831 Session *s = &sessions[i];
1832 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1833 debug("session_by_tty: session %d tty %s", i, tty);
1837 debug("session_by_tty: unknown tty %.100s", tty);
1843 session_by_channel(int id)
1846 for (i = 0; i < MAX_SESSIONS; i++) {
1847 Session *s = &sessions[i];
1848 if (s->used && s->chanid == id) {
1849 debug("session_by_channel: session %d channel %d", i, id);
1853 debug("session_by_channel: unknown channel %d", id);
1859 session_by_x11_channel(int id)
1863 for (i = 0; i < MAX_SESSIONS; i++) {
1864 Session *s = &sessions[i];
1866 if (s->x11_chanids == NULL || !s->used)
1868 for (j = 0; s->x11_chanids[j] != -1; j++) {
1869 if (s->x11_chanids[j] == id) {
1870 debug("session_by_x11_channel: session %d "
1871 "channel %d", s->self, id);
1876 debug("session_by_x11_channel: unknown channel %d", id);
1882 session_by_pid(pid_t pid)
1885 debug("session_by_pid: pid %ld", (long)pid);
1886 for (i = 0; i < MAX_SESSIONS; i++) {
1887 Session *s = &sessions[i];
1888 if (s->used && s->pid == pid)
1891 error("session_by_pid: unknown pid %ld", (long)pid);
1897 session_window_change_req(Session *s)
1899 s->col = packet_get_int();
1900 s->row = packet_get_int();
1901 s->xpixel = packet_get_int();
1902 s->ypixel = packet_get_int();
1904 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1909 session_pty_req(Session *s)
1915 debug("Allocating a pty not permitted for this authentication.");
1918 if (s->ttyfd != -1) {
1919 packet_disconnect("Protocol error: you already have a pty.");
1923 s->term = packet_get_string(&len);
1926 s->col = packet_get_int();
1927 s->row = packet_get_int();
1929 s->row = packet_get_int();
1930 s->col = packet_get_int();
1932 s->xpixel = packet_get_int();
1933 s->ypixel = packet_get_int();
1935 if (strcmp(s->term, "") == 0) {
1940 /* Allocate a pty and open it. */
1941 debug("Allocating pty.");
1942 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1948 error("session_pty_req: session %d alloc failed", s->self);
1951 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1953 /* for SSH1 the tty modes length is not given */
1955 n_bytes = packet_remaining();
1956 tty_parse_modes(s->ttyfd, &n_bytes);
1959 pty_setowner(s->pw, s->tty);
1961 /* Set window size from the packet. */
1962 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1965 session_proctitle(s);
1970 session_subsystem_req(Session *s)
1975 char *prog, *cmd, *subsys = packet_get_string(&len);
1979 logit("subsystem request for %.100s", subsys);
1981 for (i = 0; i < options.num_subsystems; i++) {
1982 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1983 prog = options.subsystem_command[i];
1984 cmd = options.subsystem_args[i];
1985 if (!strcmp(INTERNAL_SFTP_NAME, prog)) {
1986 s->is_subsystem = SUBSYSTEM_INT_SFTP;
1987 } else if (stat(prog, &st) < 0) {
1988 error("subsystem: cannot stat %s: %s", prog,
1992 s->is_subsystem = SUBSYSTEM_EXT;
1994 debug("subsystem: exec() %s", cmd);
2002 logit("subsystem request for %.100s failed, subsystem not found",
2010 session_x11_req(Session *s)
2014 if (s->auth_proto != NULL || s->auth_data != NULL) {
2015 error("session_x11_req: session %d: "
2016 "x11 forwarding already active", s->self);
2019 s->single_connection = packet_get_char();
2020 s->auth_proto = packet_get_string(NULL);
2021 s->auth_data = packet_get_string(NULL);
2022 s->screen = packet_get_int();
2025 success = session_setup_x11fwd(s);
2027 xfree(s->auth_proto);
2028 xfree(s->auth_data);
2029 s->auth_proto = NULL;
2030 s->auth_data = NULL;
2036 session_shell_req(Session *s)
2044 session_exec_req(Session *s)
2047 char *command = packet_get_string(&len);
2049 do_exec(s, command);
2055 session_break_req(Session *s)
2058 packet_get_int(); /* ignored */
2061 if (s->ttyfd == -1 ||
2062 tcsendbreak(s->ttyfd, 0) < 0)
2068 session_env_req(Session *s)
2071 u_int name_len, val_len, i;
2073 name = packet_get_string(&name_len);
2074 val = packet_get_string(&val_len);
2077 /* Don't set too many environment variables */
2078 if (s->num_env > 128) {
2079 debug2("Ignoring env request %s: too many env vars", name);
2083 for (i = 0; i < options.num_accept_env; i++) {
2084 if (match_pattern(name, options.accept_env[i])) {
2085 debug2("Setting env %d: %s=%s", s->num_env, name, val);
2086 s->env = xrealloc(s->env, s->num_env + 1,
2088 s->env[s->num_env].name = name;
2089 s->env[s->num_env].val = val;
2094 debug2("Ignoring env request %s: disallowed name", name);
2103 session_auth_agent_req(Session *s)
2105 static int called = 0;
2107 if (no_agent_forwarding_flag) {
2108 debug("session_auth_agent_req: no_agent_forwarding_flag");
2115 return auth_input_request_forwarding(s->pw);
2120 session_input_channel_req(Channel *c, const char *rtype)
2125 if ((s = session_by_channel(c->self)) == NULL) {
2126 logit("session_input_channel_req: no session %d req %.100s",
2130 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2133 * a session is in LARVAL state until a shell, a command
2134 * or a subsystem is executed
2136 if (c->type == SSH_CHANNEL_LARVAL) {
2137 if (strcmp(rtype, "shell") == 0) {
2138 success = session_shell_req(s);
2139 } else if (strcmp(rtype, "exec") == 0) {
2140 success = session_exec_req(s);
2141 } else if (strcmp(rtype, "pty-req") == 0) {
2142 success = session_pty_req(s);
2143 } else if (strcmp(rtype, "x11-req") == 0) {
2144 success = session_x11_req(s);
2145 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2146 success = session_auth_agent_req(s);
2147 } else if (strcmp(rtype, "subsystem") == 0) {
2148 success = session_subsystem_req(s);
2149 } else if (strcmp(rtype, "env") == 0) {
2150 success = session_env_req(s);
2153 if (strcmp(rtype, "window-change") == 0) {
2154 success = session_window_change_req(s);
2155 } else if (strcmp(rtype, "break") == 0) {
2156 success = session_break_req(s);
2163 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2166 fatal("session_set_fds: called for proto != 2.0");
2168 * now that have a child and a pipe to the child,
2169 * we can activate our channel and register the fd's
2171 if (s->chanid == -1)
2172 fatal("no channel for session %d", s->self);
2173 channel_set_fds(s->chanid,
2175 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2177 CHAN_SES_WINDOW_DEFAULT);
2181 * Function to perform pty cleanup. Also called if we get aborted abnormally
2182 * (e.g., due to a dropped connection).
2185 session_pty_cleanup2(Session *s)
2188 error("session_pty_cleanup: no session");
2194 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2196 /* Record that the user has logged out. */
2198 record_logout(s->pid, s->tty, s->pw->pw_name);
2200 /* Release the pseudo-tty. */
2202 pty_release(s->tty);
2205 * Close the server side of the socket pairs. We must do this after
2206 * the pty cleanup, so that another process doesn't get this pty
2207 * while we're still cleaning up.
2209 if (close(s->ptymaster) < 0)
2210 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2212 /* unlink pty from session */
2217 session_pty_cleanup(Session *s)
2219 PRIVSEP(session_pty_cleanup2(s));
2225 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2240 return "SIG@openssh.com";
2244 session_close_x11(int id)
2248 if ((c = channel_by_id(id)) == NULL) {
2249 debug("session_close_x11: x11 channel %d missing", id);
2251 /* Detach X11 listener */
2252 debug("session_close_x11: detach x11 channel %d", id);
2253 channel_cancel_cleanup(id);
2254 if (c->ostate != CHAN_OUTPUT_CLOSED)
2260 session_close_single_x11(int id, void *arg)
2265 debug3("session_close_single_x11: channel %d", id);
2266 channel_cancel_cleanup(id);
2267 if ((s = session_by_x11_channel(id)) == NULL)
2268 fatal("session_close_single_x11: no x11 channel %d", id);
2269 for (i = 0; s->x11_chanids[i] != -1; i++) {
2270 debug("session_close_single_x11: session %d: "
2271 "closing channel %d", s->self, s->x11_chanids[i]);
2273 * The channel "id" is already closing, but make sure we
2274 * close all of its siblings.
2276 if (s->x11_chanids[i] != id)
2277 session_close_x11(s->x11_chanids[i]);
2279 xfree(s->x11_chanids);
2280 s->x11_chanids = NULL;
2285 if (s->auth_proto) {
2286 xfree(s->auth_proto);
2287 s->auth_proto = NULL;
2290 xfree(s->auth_data);
2291 s->auth_data = NULL;
2293 if (s->auth_display) {
2294 xfree(s->auth_display);
2295 s->auth_display = NULL;
2300 session_exit_message(Session *s, int status)
2304 if ((c = channel_lookup(s->chanid)) == NULL)
2305 fatal("session_exit_message: session %d: no channel %d",
2306 s->self, s->chanid);
2307 debug("session_exit_message: session %d channel %d pid %ld",
2308 s->self, s->chanid, (long)s->pid);
2310 if (WIFEXITED(status)) {
2311 channel_request_start(s->chanid, "exit-status", 0);
2312 packet_put_int(WEXITSTATUS(status));
2314 } else if (WIFSIGNALED(status)) {
2315 channel_request_start(s->chanid, "exit-signal", 0);
2316 packet_put_cstring(sig2name(WTERMSIG(status)));
2318 packet_put_char(WCOREDUMP(status)? 1 : 0);
2319 #else /* WCOREDUMP */
2321 #endif /* WCOREDUMP */
2322 packet_put_cstring("");
2323 packet_put_cstring("");
2326 /* Some weird exit cause. Just exit. */
2327 packet_disconnect("wait returned status %04x.", status);
2330 /* disconnect channel */
2331 debug("session_exit_message: release channel %d", s->chanid);
2334 * Adjust cleanup callback attachment to send close messages when
2335 * the channel gets EOF. The session will be then be closed
2336 * by session_close_by_channel when the childs close their fds.
2338 channel_register_cleanup(c->self, session_close_by_channel, 1);
2341 * emulate a write failure with 'chan_write_failed', nobody will be
2342 * interested in data we write.
2343 * Note that we must not call 'chan_read_failed', since there could
2344 * be some more data waiting in the pipe.
2346 if (c->ostate != CHAN_OUTPUT_CLOSED)
2347 chan_write_failed(c);
2351 session_close(Session *s)
2355 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2357 session_pty_cleanup(s);
2363 xfree(s->x11_chanids);
2364 if (s->auth_display)
2365 xfree(s->auth_display);
2367 xfree(s->auth_data);
2369 xfree(s->auth_proto);
2371 if (s->env != NULL) {
2372 for (i = 0; i < s->num_env; i++) {
2373 xfree(s->env[i].name);
2374 xfree(s->env[i].val);
2378 session_proctitle(s);
2382 session_close_by_pid(pid_t pid, int status)
2384 Session *s = session_by_pid(pid);
2386 debug("session_close_by_pid: no session for pid %ld",
2390 if (s->chanid != -1)
2391 session_exit_message(s, status);
2393 session_pty_cleanup(s);
2398 * this is called when a channel dies before
2399 * the session 'child' itself dies
2402 session_close_by_channel(int id, void *arg)
2404 Session *s = session_by_channel(id);
2408 debug("session_close_by_channel: no session for id %d", id);
2411 debug("session_close_by_channel: channel %d child %ld",
2414 debug("session_close_by_channel: channel %d: has child", id);
2416 * delay detach of session, but release pty, since
2417 * the fd's to the child are already closed
2420 session_pty_cleanup(s);
2423 /* detach by removing callback */
2424 channel_cancel_cleanup(s->chanid);
2426 /* Close any X11 listeners associated with this session */
2427 if (s->x11_chanids != NULL) {
2428 for (i = 0; s->x11_chanids[i] != -1; i++) {
2429 session_close_x11(s->x11_chanids[i]);
2430 s->x11_chanids[i] = -1;
2439 session_destroy_all(void (*closefunc)(Session *))
2442 for (i = 0; i < MAX_SESSIONS; i++) {
2443 Session *s = &sessions[i];
2445 if (closefunc != NULL)
2454 session_tty_list(void)
2456 static char buf[1024];
2461 for (i = 0; i < MAX_SESSIONS; i++) {
2462 Session *s = &sessions[i];
2463 if (s->used && s->ttyfd != -1) {
2465 if (strncmp(s->tty, "/dev/", 5) != 0) {
2466 cp = strrchr(s->tty, '/');
2467 cp = (cp == NULL) ? s->tty : cp + 1;
2472 strlcat(buf, ",", sizeof buf);
2473 strlcat(buf, cp, sizeof buf);
2477 strlcpy(buf, "notty", sizeof buf);
2482 session_proctitle(Session *s)
2485 error("no user for session %d", s->self);
2487 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2491 session_setup_x11fwd(Session *s)
2494 char display[512], auth_display[512];
2495 char hostname[MAXHOSTNAMELEN];
2498 if (no_x11_forwarding_flag) {
2499 packet_send_debug("X11 forwarding disabled in user configuration file.");
2502 if (!options.x11_forwarding) {
2503 debug("X11 forwarding disabled in server configuration file.");
2506 if (!options.xauth_location ||
2507 (stat(options.xauth_location, &st) == -1)) {
2508 packet_send_debug("No xauth program; cannot forward with spoofing.");
2511 if (options.use_login) {
2512 packet_send_debug("X11 forwarding disabled; "
2513 "not compatible with UseLogin=yes.");
2516 if (s->display != NULL) {
2517 debug("X11 display already set.");
2520 if (x11_create_display_inet(options.x11_display_offset,
2521 options.x11_use_localhost, s->single_connection,
2522 &s->display_number, &s->x11_chanids) == -1) {
2523 debug("x11_create_display_inet failed.");
2526 for (i = 0; s->x11_chanids[i] != -1; i++) {
2527 channel_register_cleanup(s->x11_chanids[i],
2528 session_close_single_x11, 0);
2531 /* Set up a suitable value for the DISPLAY variable. */
2532 if (gethostname(hostname, sizeof(hostname)) < 0)
2533 fatal("gethostname: %.100s", strerror(errno));
2535 * auth_display must be used as the displayname when the
2536 * authorization entry is added with xauth(1). This will be
2537 * different than the DISPLAY string for localhost displays.
2539 if (options.x11_use_localhost) {
2540 snprintf(display, sizeof display, "localhost:%u.%u",
2541 s->display_number, s->screen);
2542 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2543 s->display_number, s->screen);
2544 s->display = xstrdup(display);
2545 s->auth_display = xstrdup(auth_display);
2547 #ifdef IPADDR_IN_DISPLAY
2549 struct in_addr my_addr;
2551 he = gethostbyname(hostname);
2553 error("Can't get IP address for X11 DISPLAY.");
2554 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2557 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2558 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2559 s->display_number, s->screen);
2561 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2562 s->display_number, s->screen);
2564 s->display = xstrdup(display);
2565 s->auth_display = xstrdup(display);
2572 do_authenticated2(Authctxt *authctxt)
2574 server_loop2(authctxt);
2578 do_cleanup(Authctxt *authctxt)
2580 static int called = 0;
2582 debug("do_cleanup");
2584 /* no cleanup if we're in the child for login shell */
2588 /* avoid double cleanup */
2593 if (authctxt == NULL)
2597 if (options.use_pam) {
2599 sshpam_thread_cleanup();
2603 if (!authctxt->authenticated)
2607 if (options.kerberos_ticket_cleanup &&
2609 krb5_cleanup_proc(authctxt);
2613 if (compat20 && options.gss_cleanup_creds)
2614 ssh_gssapi_cleanup_creds();
2617 /* remove agent socket */
2618 auth_sock_cleanup_proc(authctxt->pw);
2621 * Cleanup ptys/utmp only if privsep is disabled,
2622 * or if running in monitor.
2624 if (!use_privsep || mm_is_monitor())
2625 session_destroy_all(session_pty_cleanup2);