1 /* $OpenBSD: session.c,v 1.221 2007/01/21 01:41:54 stevesk Exp $ */
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * As far as I am concerned, the code I have written for this software
7 * can be used freely for any purpose. Any derived versions of this
8 * software must be clearly marked as such, and if the derived work is
9 * incompatible with the protocol description in the RFC file, it must be
10 * called by a name other than "ssh" or "Secure Shell".
12 * SSH2 support by Markus Friedl.
13 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 #include <sys/types.h>
39 #include <sys/param.h>
40 #ifdef HAVE_SYS_STAT_H
41 # include <sys/stat.h>
43 #include <sys/socket.h>
47 #include <arpa/inet.h>
80 #include "auth-options.h"
81 #include "pathnames.h"
85 #include "serverloop.h"
89 #include "monitor_wrap.h"
91 #if defined(KRB5) && defined(USE_AFS)
97 Session *session_new(void);
98 void session_set_fds(Session *, int, int, int);
99 void session_pty_cleanup(Session *);
100 void session_proctitle(Session *);
101 int session_setup_x11fwd(Session *);
102 void do_exec_pty(Session *, const char *);
103 void do_exec_no_pty(Session *, const char *);
104 void do_exec(Session *, const char *);
105 void do_login(Session *, const char *);
106 #ifdef LOGIN_NEEDS_UTMPX
107 static void do_pre_login(Session *s);
109 void do_child(Session *, const char *);
111 int check_quietlogin(Session *, const char *);
113 static void do_authenticated1(Authctxt *);
114 static void do_authenticated2(Authctxt *);
116 static int session_pty_req(Session *);
119 static void execute_session_hook(char* prog, Authctxt *authctxt,
120 int startup, int save);
124 extern ServerOptions options;
125 extern char *__progname;
126 extern int log_stderr;
127 extern int debug_flag;
128 extern u_int utmp_len;
129 extern int startup_pipe;
130 extern void destroy_sensitive_data(void);
131 extern Buffer loginmsg;
133 /* original command from peer. */
134 const char *original_command = NULL;
137 #define MAX_SESSIONS 10
138 Session sessions[MAX_SESSIONS];
140 #ifdef HAVE_LOGIN_CAP
144 static int is_child = 0;
146 /* Name and directory of socket for authentication agent forwarding. */
147 static char *auth_sock_name = NULL;
148 static char *auth_sock_dir = NULL;
150 /* removes the agent forwarding socket */
153 auth_sock_cleanup_proc(struct passwd *pw)
155 if (auth_sock_name != NULL) {
156 temporarily_use_uid(pw);
157 unlink(auth_sock_name);
158 rmdir(auth_sock_dir);
159 auth_sock_name = NULL;
165 auth_input_request_forwarding(struct passwd * pw)
169 struct sockaddr_un sunaddr;
171 if (auth_sock_name != NULL) {
172 error("authentication forwarding requested twice.");
176 /* Temporarily drop privileged uid for mkdir/bind. */
177 temporarily_use_uid(pw);
179 /* Allocate a buffer for the socket name, and format the name. */
180 auth_sock_name = xmalloc(MAXPATHLEN);
181 auth_sock_dir = xmalloc(MAXPATHLEN);
182 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
184 /* Create private directory for socket */
185 if (mkdtemp(auth_sock_dir) == NULL) {
186 packet_send_debug("Agent forwarding disabled: "
187 "mkdtemp() failed: %.100s", strerror(errno));
189 xfree(auth_sock_name);
190 xfree(auth_sock_dir);
191 auth_sock_name = NULL;
192 auth_sock_dir = NULL;
195 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
196 auth_sock_dir, (long) getpid());
198 /* Create the socket. */
199 sock = socket(AF_UNIX, SOCK_STREAM, 0);
201 packet_disconnect("socket: %.100s", strerror(errno));
203 /* Bind it to the name. */
204 memset(&sunaddr, 0, sizeof(sunaddr));
205 sunaddr.sun_family = AF_UNIX;
206 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
208 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0)
209 packet_disconnect("bind: %.100s", strerror(errno));
211 /* Restore the privileged uid. */
214 /* Start listening on the socket. */
215 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
216 packet_disconnect("listen: %.100s", strerror(errno));
218 /* Allocate a channel for the authentication agent socket. */
219 /* this shouldn't matter if its hpn or not - cjr */
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);
253 if (options.session_hooks_allow &&
254 options.session_hooks_shutdown_cmd)
256 execute_session_hook(options.session_hooks_shutdown_cmd,
258 /* startup = */ 0, /* save = */ 0);
260 if (authctxt->session_env_file)
262 free(authctxt->session_env_file);
267 do_cleanup(authctxt);
271 * Prepares for an interactive session. This is called after the user has
272 * been successfully authenticated. During this message exchange, pseudo
273 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
274 * are requested, etc.
277 do_authenticated1(Authctxt *authctxt)
281 int success, type, screen_flag;
282 int enable_compression_after_reply = 0;
283 u_int proto_len, data_len, dlen, compression_level = 0;
287 error("no more sessions");
290 s->authctxt = authctxt;
291 s->pw = authctxt->pw;
294 * We stay in this loop until the client requests to execute a shell
300 /* Get a packet from the client. */
301 type = packet_read();
303 /* Process the packet. */
305 case SSH_CMSG_REQUEST_COMPRESSION:
306 compression_level = packet_get_int();
308 if (compression_level < 1 || compression_level > 9) {
309 packet_send_debug("Received invalid compression level %d.",
313 if (options.compression == COMP_NONE) {
314 debug2("compression disabled");
317 /* Enable compression after we have responded with SUCCESS. */
318 enable_compression_after_reply = 1;
322 case SSH_CMSG_REQUEST_PTY:
323 success = session_pty_req(s);
326 case SSH_CMSG_X11_REQUEST_FORWARDING:
327 s->auth_proto = packet_get_string(&proto_len);
328 s->auth_data = packet_get_string(&data_len);
330 screen_flag = packet_get_protocol_flags() &
331 SSH_PROTOFLAG_SCREEN_NUMBER;
332 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
334 if (packet_remaining() == 4) {
336 debug2("Buggy client: "
337 "X11 screen flag missing");
338 s->screen = packet_get_int();
343 success = session_setup_x11fwd(s);
345 xfree(s->auth_proto);
347 s->auth_proto = NULL;
352 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
353 if (no_agent_forwarding_flag || compat13) {
354 debug("Authentication agent forwarding not permitted for this authentication.");
357 debug("Received authentication agent forwarding request.");
358 success = auth_input_request_forwarding(s->pw);
361 case SSH_CMSG_PORT_FORWARD_REQUEST:
362 if (no_port_forwarding_flag) {
363 debug("Port forwarding not permitted for this authentication.");
366 if (!options.allow_tcp_forwarding) {
367 debug("Port forwarding not permitted.");
370 debug("Received TCP/IP port forwarding request.");
371 if (channel_input_port_forward_request(s->pw->pw_uid == 0,
372 options.gateway_ports, options.hpn_disabled,
373 options.hpn_buffer_size) < 0) {
374 debug("Port forwarding failed.");
380 case SSH_CMSG_MAX_PACKET_SIZE:
381 if (packet_set_maxsize(packet_get_int()) > 0)
385 case SSH_CMSG_EXEC_SHELL:
386 case SSH_CMSG_EXEC_CMD:
387 if (type == SSH_CMSG_EXEC_CMD) {
388 command = packet_get_string(&dlen);
389 debug("Exec command '%.500s'", command);
401 * Any unknown messages in this phase are ignored,
402 * and a failure message is returned.
404 logit("Unknown packet type received after authentication: %d", type);
406 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
410 /* Enable compression now that we have replied if appropriate. */
411 if (enable_compression_after_reply) {
412 enable_compression_after_reply = 0;
413 packet_start_compression(compression_level);
419 * This is called to fork and execute a command when we have no tty. This
420 * will call do_child from the child, and server_loop from the parent after
421 * setting up file descriptors and such.
424 do_exec_no_pty(Session *s, const char *command)
429 int pin[2], pout[2], perr[2];
430 /* Allocate pipes for communicating with the program. */
431 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
432 packet_disconnect("Could not create pipes: %.100s",
434 #else /* USE_PIPES */
435 int inout[2], err[2];
436 /* Uses socket pairs to communicate with the program. */
437 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
438 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
439 packet_disconnect("Could not create socket pairs: %.100s",
441 #endif /* USE_PIPES */
443 fatal("do_exec_no_pty: no session");
445 session_proctitle(s);
448 if (options.use_pam && !use_privsep)
452 /* Fork the child. */
453 if ((pid = fork()) == 0) {
456 /* Child. Reinitialize the log since the pid has changed. */
457 log_init(__progname, options.log_level, options.log_facility, log_stderr);
460 * Create a new session and process group since the 4.4BSD
461 * setlogin() affects the entire process group.
464 error("setsid failed: %.100s", strerror(errno));
468 * Redirect stdin. We close the parent side of the socket
469 * pair, and make the child side the standard input.
472 if (dup2(pin[0], 0) < 0)
473 perror("dup2 stdin");
476 /* Redirect stdout. */
478 if (dup2(pout[1], 1) < 0)
479 perror("dup2 stdout");
482 /* Redirect stderr. */
484 if (dup2(perr[1], 2) < 0)
485 perror("dup2 stderr");
487 #else /* USE_PIPES */
489 * Redirect stdin, stdout, and stderr. Stdin and stdout will
490 * use the same socket, as some programs (particularly rdist)
491 * seem to depend on it.
495 if (dup2(inout[0], 0) < 0) /* stdin */
496 perror("dup2 stdin");
497 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
498 perror("dup2 stdout");
499 if (dup2(err[0], 2) < 0) /* stderr */
500 perror("dup2 stderr");
501 #endif /* USE_PIPES */
504 cray_init_job(s->pw); /* set up cray jid and tmpdir */
507 /* Do processing for the child (exec command etc). */
508 do_child(s, command);
512 signal(WJSIGNAL, cray_job_termination_handler);
516 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
519 packet_disconnect("fork failed: %.100s", strerror(errno));
521 /* Set interactive/non-interactive mode. */
522 packet_set_interactive(s->display != NULL);
524 /* We are the parent. Close the child sides of the pipes. */
530 if (s->is_subsystem) {
534 session_set_fds(s, pin[1], pout[0], perr[0]);
536 /* Enter the interactive session. */
537 server_loop(pid, pin[1], pout[0], perr[0]);
538 /* server_loop has closed pin[1], pout[0], and perr[0]. */
540 #else /* USE_PIPES */
541 /* We are the parent. Close the child sides of the socket pairs. */
546 * Clear loginmsg, since it's the child's responsibility to display
547 * it to the user, otherwise multiple sessions may accumulate
548 * multiple copies of the login messages.
550 buffer_clear(&loginmsg);
553 * Enter the interactive session. Note: server_loop must be able to
554 * handle the case that fdin and fdout are the same.
557 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
559 server_loop(pid, inout[1], inout[1], err[1]);
560 /* server_loop has closed inout[1] and err[1]. */
562 #endif /* USE_PIPES */
566 * This is called to fork and execute a command when we have a tty. This
567 * will call do_child from the child, and server_loop from the parent after
568 * setting up file descriptors, controlling tty, updating wtmp, utmp,
569 * lastlog, and other such operations.
572 do_exec_pty(Session *s, const char *command)
574 int fdout, ptyfd, ttyfd, ptymaster;
578 fatal("do_exec_pty: no session");
583 if (options.use_pam) {
584 do_pam_set_tty(s->tty);
590 /* Fork the child. */
591 if ((pid = fork()) == 0) {
594 /* Child. Reinitialize the log because the pid has changed. */
595 log_init(__progname, options.log_level, options.log_facility, log_stderr);
596 /* Close the master side of the pseudo tty. */
599 /* Make the pseudo tty our controlling tty. */
600 pty_make_controlling_tty(&ttyfd, s->tty);
602 /* Redirect stdin/stdout/stderr from the pseudo tty. */
603 if (dup2(ttyfd, 0) < 0)
604 error("dup2 stdin: %s", strerror(errno));
605 if (dup2(ttyfd, 1) < 0)
606 error("dup2 stdout: %s", strerror(errno));
607 if (dup2(ttyfd, 2) < 0)
608 error("dup2 stderr: %s", strerror(errno));
610 /* Close the extra descriptor for the pseudo tty. */
613 /* record login, etc. similar to login(1) */
615 if (!(options.use_login && command == NULL)) {
617 cray_init_job(s->pw); /* set up cray jid and tmpdir */
619 do_login(s, command);
621 # ifdef LOGIN_NEEDS_UTMPX
627 /* Do common processing for the child, such as execing the command. */
628 do_child(s, command);
632 signal(WJSIGNAL, cray_job_termination_handler);
636 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
639 packet_disconnect("fork failed: %.100s", strerror(errno));
642 /* Parent. Close the slave side of the pseudo tty. */
646 * Create another descriptor of the pty master side for use as the
647 * standard input. We could use the original descriptor, but this
648 * simplifies code in server_loop. The descriptor is bidirectional.
652 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
654 /* we keep a reference to the pty master */
655 ptymaster = dup(ptyfd);
657 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
658 s->ptymaster = ptymaster;
660 /* Enter interactive session. */
661 packet_set_interactive(1);
663 session_set_fds(s, ptyfd, fdout, -1);
665 server_loop(pid, ptyfd, fdout, -1);
666 /* server_loop _has_ closed ptyfd and fdout. */
670 #ifdef LOGIN_NEEDS_UTMPX
672 do_pre_login(Session *s)
675 struct sockaddr_storage from;
676 pid_t pid = getpid();
679 * Get IP address of client. If the connection is not a socket, let
680 * the address be 0.0.0.0.
682 memset(&from, 0, sizeof(from));
683 fromlen = sizeof(from);
684 if (packet_connection_is_on_socket()) {
685 if (getpeername(packet_get_connection_in(),
686 (struct sockaddr *)&from, &fromlen) < 0) {
687 debug("getpeername: %.100s", strerror(errno));
692 record_utmp_only(pid, s->tty, s->pw->pw_name,
693 get_remote_name_or_ip(utmp_len, options.use_dns),
694 (struct sockaddr *)&from, fromlen);
699 * This is called to fork and execute a command. If another command is
700 * to be forced, execute that instead.
703 do_exec(Session *s, const char *command)
705 if (options.adm_forced_command) {
706 original_command = command;
707 command = options.adm_forced_command;
708 debug("Forced command (config) '%.900s'", command);
709 } else if (forced_command) {
710 original_command = command;
711 command = forced_command;
712 debug("Forced command (key option) '%.900s'", command);
715 #if defined(SESSION_HOOKS)
716 if (options.session_hooks_allow &&
717 (options.session_hooks_startup_cmd ||
718 options.session_hooks_shutdown_cmd))
726 "/tmp/ssh_env_%d%d%d",
730 } while (stat(env_file, &st)==0);
731 s->authctxt->session_env_file = strdup(env_file);
735 #ifdef SSH_AUDIT_EVENTS
737 PRIVSEP(audit_run_command(command));
738 else if (s->ttyfd == -1) {
739 char *shell = s->pw->pw_shell;
741 if (shell[0] == '\0') /* empty shell means /bin/sh */
743 PRIVSEP(audit_run_command(shell));
748 do_exec_pty(s, command);
750 do_exec_no_pty(s, command);
752 original_command = NULL;
755 * Clear loginmsg: it's the child's responsibility to display
756 * it to the user, otherwise multiple sessions may accumulate
757 * multiple copies of the login messages.
759 buffer_clear(&loginmsg);
762 /* administrative, login(1)-like work */
764 do_login(Session *s, const char *command)
767 struct sockaddr_storage from;
768 struct passwd * pw = s->pw;
769 pid_t pid = getpid();
772 * Get IP address of client. If the connection is not a socket, let
773 * the address be 0.0.0.0.
775 memset(&from, 0, sizeof(from));
776 fromlen = sizeof(from);
777 if (packet_connection_is_on_socket()) {
778 if (getpeername(packet_get_connection_in(),
779 (struct sockaddr *) & from, &fromlen) < 0) {
780 debug("getpeername: %.100s", strerror(errno));
785 /* Record that there was a login on that tty from the remote host. */
787 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
788 get_remote_name_or_ip(utmp_len,
790 (struct sockaddr *)&from, fromlen);
794 * If password change is needed, do it now.
795 * This needs to occur before the ~/.hushlogin check.
797 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
800 s->authctxt->force_pwchange = 0;
801 /* XXX - signal [net] parent to enable forwardings */
805 if (check_quietlogin(s, command))
814 * Display the message of the day.
822 if (options.print_motd) {
823 #ifdef HAVE_LOGIN_CAP
824 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
827 f = fopen("/etc/motd", "r");
830 while (fgets(buf, sizeof(buf), f))
839 * Check for quiet login, either .hushlogin or command given.
842 check_quietlogin(Session *s, const char *command)
845 struct passwd *pw = s->pw;
848 /* Return 1 if .hushlogin exists or a command given. */
851 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
852 #ifdef HAVE_LOGIN_CAP
853 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
856 if (stat(buf, &st) >= 0)
863 * Sets the value of the given variable in the environment. If the variable
864 * already exists, its value is overriden.
867 child_set_env(char ***envp, u_int *envsizep, const char *name,
875 * If we're passed an uninitialized list, allocate a single null
876 * entry before continuing.
878 if (*envp == NULL && *envsizep == 0) {
879 *envp = xmalloc(sizeof(char *));
885 * Find the slot where the value should be stored. If the variable
886 * already exists, we reuse the slot; otherwise we append a new slot
887 * at the end of the array, expanding if necessary.
890 namelen = strlen(name);
891 for (i = 0; env[i]; i++)
892 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
895 /* Reuse the slot. */
898 /* New variable. Expand if necessary. */
900 if (i >= envsize - 1) {
902 fatal("child_set_env: too many env vars");
904 env = (*envp) = xrealloc(env, envsize, sizeof(char *));
907 /* Need to set the NULL pointer at end of array beyond the new slot. */
911 /* Allocate space and format the variable in the appropriate slot. */
912 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
913 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
917 * Reads environment variables from the given file and adds/overrides them
918 * into the environment. If the file does not exist, this does nothing.
919 * Otherwise, it must consist of empty lines, comments (line starts with '#')
920 * and assignments of the form name=value. No other forms are allowed.
923 read_environment_file(char ***env, u_int *envsize,
924 const char *filename)
931 f = fopen(filename, "r");
935 while (fgets(buf, sizeof(buf), f)) {
937 fatal("Too many lines in environment file %s", filename);
938 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
940 if (!*cp || *cp == '#' || *cp == '\n')
942 if (strchr(cp, '\n'))
943 *strchr(cp, '\n') = '\0';
944 value = strchr(cp, '=');
946 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
951 * Replace the equals sign by nul, and advance value to
956 child_set_env(env, envsize, cp, value);
962 #define SSH_SESSION_ENV_FILE "SSH_SESSION_ENV_FILE"
964 typedef enum { no_op, execute, clear_env, restore_env,
965 read_env, save_or_rm_env } session_action_t;
967 static session_action_t action_order[2][5] = {
968 { clear_env, read_env, execute, save_or_rm_env, restore_env }, /*shutdown*/
969 { execute, read_env, save_or_rm_env, no_op, no_op } /*startup */
973 void execute_session_hook(char* prog, Authctxt *authctxt,
974 int startup, int save)
976 extern char **environ;
979 char **saved_env, **tmpenv;
980 char *env_file = authctxt->session_env_file;
985 switch (action_order[startup][i])
998 authctxt->pw->pw_shell,
1001 debug("executing session hook: [%s]", buf);
1002 setenv(SSH_SESSION_ENV_FILE, env_file, /* overwrite = */ 1);
1004 /* flusing is recommended in the popen(3) man page, to avoid
1005 intermingling of output */
1008 if ((fp=popen(buf, "w")) == NULL)
1010 perror("Unable to run session hook");
1013 status = pclose(fp);
1014 debug2("session hook executed, status=%d", status);
1015 unsetenv(SSH_SESSION_ENV_FILE);
1020 saved_env = environ;
1021 tmpenv = (char**) malloc(sizeof(char*));
1027 environ = saved_env;
1032 if (status==0 && stat(env_file, &st)==0)
1036 debug("reading environment from %s", env_file);
1037 while (environ[envsize++]) ;
1038 read_environment_file(&environ, &envsize, env_file);
1042 case save_or_rm_env:
1043 if (status==0 && save)
1048 debug2("saving environment to %s", env_file);
1049 if ((fp = fopen(env_file, "w")) == NULL) /* hmm: file perms? */
1051 perror("Unable to save session hook info");
1053 while (environ[envcount])
1055 fprintf(fp, "%s\n", environ[envcount++]);
1060 else if (stat(env_file, &st)==0)
1062 debug2("removing environment file %s", env_file);
1072 #ifdef HAVE_ETC_DEFAULT_LOGIN
1074 * Return named variable from specified environment, or NULL if not present.
1077 child_get_env(char **env, const char *name)
1083 for (i=0; env[i] != NULL; i++)
1084 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
1085 return(env[i] + len + 1);
1090 * Read /etc/default/login.
1091 * We pick up the PATH (or SUPATH for root) and UMASK.
1094 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
1096 char **tmpenv = NULL, *var;
1097 u_int i, tmpenvsize = 0;
1101 * We don't want to copy the whole file to the child's environment,
1102 * so we use a temporary environment and copy the variables we're
1105 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
1111 var = child_get_env(tmpenv, "SUPATH");
1113 var = child_get_env(tmpenv, "PATH");
1115 child_set_env(env, envsize, "PATH", var);
1117 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
1118 if (sscanf(var, "%5lo", &mask) == 1)
1119 umask((mode_t)mask);
1121 for (i = 0; tmpenv[i] != NULL; i++)
1125 #endif /* HAVE_ETC_DEFAULT_LOGIN */
1128 copy_environment(char **source, char ***env, u_int *envsize)
1130 char *var_name, *var_val;
1136 for(i = 0; source[i] != NULL; i++) {
1137 var_name = xstrdup(source[i]);
1138 if ((var_val = strstr(var_name, "=")) == NULL) {
1144 debug3("Copy environment: %s=%s", var_name, var_val);
1145 child_set_env(env, envsize, var_name, var_val);
1152 do_setup_env(Session *s, const char *shell)
1157 struct passwd *pw = s->pw;
1158 #ifndef HAVE_LOGIN_CAP
1162 /* Initialize the environment. */
1164 env = xcalloc(envsize, sizeof(char *));
1169 * The Windows environment contains some setting which are
1170 * important for a running system. They must not be dropped.
1175 p = fetch_windows_environment();
1176 copy_environment(p, &env, &envsize);
1177 free_windows_environment(p);
1182 /* Allow any GSSAPI methods that we've used to alter
1183 * the childs environment as they see fit
1185 ssh_gssapi_do_child(&env, &envsize);
1188 if (!options.use_login) {
1189 /* Set basic environment. */
1190 for (i = 0; i < s->num_env; i++)
1191 child_set_env(&env, &envsize, s->env[i].name,
1194 child_set_env(&env, &envsize, "USER", pw->pw_name);
1195 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1197 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1199 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1200 #ifdef HAVE_LOGIN_CAP
1201 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1202 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1204 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1205 #else /* HAVE_LOGIN_CAP */
1206 # ifndef HAVE_CYGWIN
1208 * There's no standard path on Windows. The path contains
1209 * important components pointing to the system directories,
1210 * needed for loading shared libraries. So the path better
1211 * remains intact here.
1213 # ifdef HAVE_ETC_DEFAULT_LOGIN
1214 read_etc_default_login(&env, &envsize, pw->pw_uid);
1215 path = child_get_env(env, "PATH");
1216 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1217 if (path == NULL || *path == '\0') {
1218 child_set_env(&env, &envsize, "PATH",
1219 s->pw->pw_uid == 0 ?
1220 SUPERUSER_PATH : _PATH_STDPATH);
1222 # endif /* HAVE_CYGWIN */
1223 #endif /* HAVE_LOGIN_CAP */
1225 snprintf(buf, sizeof buf, "%.200s/%.50s",
1226 _PATH_MAILDIR, pw->pw_name);
1227 child_set_env(&env, &envsize, "MAIL", buf);
1229 /* Normal systems set SHELL by default. */
1230 child_set_env(&env, &envsize, "SHELL", shell);
1233 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1235 #ifdef GSI /* GSI shared libs typically installed in non-system locations. */
1239 if ((cp = getenv("LD_LIBRARY_PATH")) != NULL)
1240 child_set_env(&env, &envsize, "LD_LIBRARY_PATH", cp);
1241 if ((cp = getenv("LIBPATH")) != NULL)
1242 child_set_env(&env, &envsize, "LIBPATH", cp);
1243 if ((cp = getenv("SHLIB_PATH")) != NULL)
1244 child_set_env(&env, &envsize, "SHLIB_PATH", cp);
1245 if ((cp = getenv("LD_LIBRARYN32_PATH")) != NULL)
1246 child_set_env(&env, &envsize, "LD_LIBRARYN32_PATH",cp);
1247 if ((cp = getenv("LD_LIBRARY64_PATH")) != NULL)
1248 child_set_env(&env, &envsize, "LD_LIBRARY64_PATH",cp);
1252 /* Set custom environment options from RSA authentication. */
1253 if (!options.use_login) {
1254 while (custom_environment) {
1255 struct envstring *ce = custom_environment;
1258 for (i = 0; str[i] != '=' && str[i]; i++)
1260 if (str[i] == '=') {
1262 child_set_env(&env, &envsize, str, str + i + 1);
1264 custom_environment = ce->next;
1270 /* SSH_CLIENT deprecated */
1271 snprintf(buf, sizeof buf, "%.50s %d %d",
1272 get_remote_ipaddr(), get_remote_port(), get_local_port());
1273 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1275 laddr = get_local_ipaddr(packet_get_connection_in());
1276 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1277 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1279 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1282 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1284 child_set_env(&env, &envsize, "TERM", s->term);
1286 child_set_env(&env, &envsize, "DISPLAY", s->display);
1287 if (original_command)
1288 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1292 if (cray_tmpdir[0] != '\0')
1293 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1294 #endif /* _UNICOS */
1297 * Since we clear KRB5CCNAME at startup, if it's set now then it
1298 * must have been set by a native authentication method (eg AIX or
1299 * SIA), so copy it to the child.
1304 if ((cp = getenv("KRB5CCNAME")) != NULL)
1305 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1312 if ((cp = getenv("AUTHSTATE")) != NULL)
1313 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1314 read_environment_file(&env, &envsize, "/etc/environment");
1318 if (s->authctxt->krb5_ccname)
1319 child_set_env(&env, &envsize, "KRB5CCNAME",
1320 s->authctxt->krb5_ccname);
1324 * Pull in any environment variables that may have
1327 if (options.use_pam) {
1330 p = fetch_pam_child_environment();
1331 copy_environment(p, &env, &envsize);
1332 free_pam_environment(p);
1334 p = fetch_pam_environment();
1335 copy_environment(p, &env, &envsize);
1336 free_pam_environment(p);
1338 #endif /* USE_PAM */
1340 if (auth_sock_name != NULL)
1341 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1344 /* read $HOME/.ssh/environment. */
1345 if (options.permit_user_env && !options.use_login) {
1346 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1347 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1348 read_environment_file(&env, &envsize, buf);
1351 /* dump the environment */
1352 fprintf(stderr, "Environment:\n");
1353 for (i = 0; env[i]; i++)
1354 fprintf(stderr, " %.200s\n", env[i]);
1360 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1361 * first in this order).
1364 do_rc_files(Session *s, const char *shell)
1372 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1374 /* ignore _PATH_SSH_USER_RC for subsystems */
1375 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1376 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1377 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1379 fprintf(stderr, "Running %s\n", cmd);
1380 f = popen(cmd, "w");
1383 fprintf(f, "%s %s\n", s->auth_proto,
1387 fprintf(stderr, "Could not run %s\n",
1389 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1391 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1392 _PATH_SSH_SYSTEM_RC);
1393 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1396 fprintf(f, "%s %s\n", s->auth_proto,
1400 fprintf(stderr, "Could not run %s\n",
1401 _PATH_SSH_SYSTEM_RC);
1402 } else if (do_xauth && options.xauth_location != NULL) {
1403 /* Add authority data to .Xauthority if appropriate. */
1406 "Running %.500s remove %.100s\n",
1407 options.xauth_location, s->auth_display);
1409 "%.500s add %.100s %.100s %.100s\n",
1410 options.xauth_location, s->auth_display,
1411 s->auth_proto, s->auth_data);
1413 snprintf(cmd, sizeof cmd, "%s -q -",
1414 options.xauth_location);
1415 f = popen(cmd, "w");
1417 fprintf(f, "remove %s\n",
1419 fprintf(f, "add %s %s %s\n",
1420 s->auth_display, s->auth_proto,
1424 fprintf(stderr, "Could not run %s\n",
1431 do_nologin(struct passwd *pw)
1436 #ifdef HAVE_LOGIN_CAP
1437 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1438 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1439 _PATH_NOLOGIN), "r");
1442 f = fopen(_PATH_NOLOGIN, "r");
1445 /* /etc/nologin exists. Print its contents and exit. */
1446 logit("User %.100s not allowed because %s exists",
1447 pw->pw_name, _PATH_NOLOGIN);
1448 while (fgets(buf, sizeof(buf), f))
1456 /* Set login name, uid, gid, and groups. */
1458 do_setusercontext(struct passwd *pw)
1461 if (getuid() == 0 || geteuid() == 0)
1462 #endif /* HAVE_CYGWIN */
1465 #ifdef HAVE_SETPCRED
1466 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1467 fatal("Failed to set process credentials");
1468 #endif /* HAVE_SETPCRED */
1469 #ifdef HAVE_LOGIN_CAP
1474 if (options.gss_authentication) {
1475 temporarily_use_uid(pw);
1476 ssh_gssapi_storecreds();
1481 if (options.use_pam) {
1483 do_pam_setcred(use_privsep);
1485 # endif /* USE_PAM */
1486 if (setusercontext(lc, pw, pw->pw_uid,
1487 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1488 perror("unable to set user context");
1492 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1493 /* Sets login uid for accounting */
1494 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1495 error("setluid: %s", strerror(errno));
1496 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1498 if (setlogin(pw->pw_name) < 0)
1499 error("setlogin failed: %s", strerror(errno));
1500 if (setgid(pw->pw_gid) < 0) {
1504 /* Initialize the group list. */
1505 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1506 perror("initgroups");
1511 if (options.gss_authentication) {
1512 temporarily_use_uid(pw);
1513 ssh_gssapi_storecreds();
1519 * PAM credentials may take the form of supplementary groups.
1520 * These will have been wiped by the above initgroups() call.
1521 * Reestablish them here.
1523 if (options.use_pam) {
1525 do_pam_setcred(use_privsep);
1527 # endif /* USE_PAM */
1528 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1529 irix_setusercontext(pw);
1530 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1535 if (set_id(pw->pw_name) != 0) {
1538 #endif /* USE_LIBIAF */
1539 /* Permanently switch to the desired uid. */
1540 permanently_set_uid(pw);
1547 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1548 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1551 ssh_selinux_setup_exec_context(pw->pw_name);
1556 do_pwchange(Session *s)
1559 fprintf(stderr, "WARNING: Your password has expired.\n");
1560 if (s->ttyfd != -1) {
1562 "You must change your password now and login again!\n");
1563 #ifdef PASSWD_NEEDS_USERNAME
1564 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1567 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1572 "Password change required but no TTY available.\n");
1578 launch_login(struct passwd *pw, const char *hostname)
1580 /* Launch login(1). */
1582 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1583 #ifdef xxxLOGIN_NEEDS_TERM
1584 (s->term ? s->term : "unknown"),
1585 #endif /* LOGIN_NEEDS_TERM */
1586 #ifdef LOGIN_NO_ENDOPT
1587 "-p", "-f", pw->pw_name, (char *)NULL);
1589 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1592 /* Login couldn't be executed, die. */
1599 child_close_fds(void)
1603 if (packet_get_connection_in() == packet_get_connection_out())
1604 close(packet_get_connection_in());
1606 close(packet_get_connection_in());
1607 close(packet_get_connection_out());
1610 * Close all descriptors related to channels. They will still remain
1611 * open in the parent.
1613 /* XXX better use close-on-exec? -markus */
1614 channel_close_all();
1617 * Close any extra file descriptors. Note that there may still be
1618 * descriptors left by system functions. They will be closed later.
1623 * Close any extra open file descriptors so that we don't have them
1624 * hanging around in clients. Note that we want to do this after
1625 * initgroups, because at least on Solaris 2.3 it leaves file
1628 for (i = 3; i < 64; i++)
1633 * Performs common processing for the child, such as setting up the
1634 * environment, closing extra file descriptors, setting the user and group
1635 * ids, and executing the command or shell.
1638 do_child(Session *s, const char *command)
1640 extern char **environ;
1643 const char *shell, *shell0, *hostname = NULL;
1644 struct passwd *pw = s->pw;
1647 /* Default place to look for aklog. */
1649 #define KPROGDIR AKLOG_PATH
1651 #define KPROGDIR "/usr/bin/aklog"
1652 #endif /* AKLOG_PATH */
1656 #endif /* AFS_KRB5 */
1658 /* remove hostkey from the child's memory */
1659 destroy_sensitive_data();
1661 /* Force a password change */
1662 if (s->authctxt->force_pwchange) {
1663 do_setusercontext(pw);
1669 /* login(1) is only called if we execute the login shell */
1670 if (options.use_login && command != NULL)
1671 options.use_login = 0;
1674 cray_setup(pw->pw_uid, pw->pw_name, command);
1675 #endif /* _UNICOS */
1678 * Login(1) does this as well, and it needs uid 0 for the "-h"
1679 * switch, so we let login(1) to this for us.
1681 if (!options.use_login) {
1683 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1684 if (!check_quietlogin(s, command))
1686 #else /* HAVE_OSF_SIA */
1687 /* When PAM is enabled we rely on it to do the nologin check */
1688 if (!options.use_pam)
1690 do_setusercontext(pw);
1692 * PAM session modules in do_setusercontext may have
1693 * generated messages, so if this in an interactive
1694 * login then display them too.
1696 if (!check_quietlogin(s, command))
1698 #endif /* HAVE_OSF_SIA */
1702 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1703 debug3("PAM session not opened, exiting");
1710 * Get the shell from the password data. An empty shell field is
1711 * legal, and means /bin/sh.
1713 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1716 * Make sure $SHELL points to the shell from the password file,
1717 * even if shell is overridden from login.conf
1719 env = do_setup_env(s, shell);
1721 #ifdef HAVE_LOGIN_CAP
1722 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1725 /* we have to stash the hostname before we close our socket. */
1726 if (options.use_login)
1727 hostname = get_remote_name_or_ip(utmp_len,
1730 * Close the connection descriptors; note that this is the child, and
1731 * the server will still have the socket open, and it is important
1732 * that we do not shutdown it. Note that the descriptors cannot be
1733 * closed before building the environment, as we call
1734 * get_remote_ipaddr there.
1739 * Must take new environment into use so that .ssh/rc,
1740 * /etc/ssh/sshrc and xauth are run in the proper environment.
1744 #if defined(KRB5) && defined(USE_AFS)
1746 * At this point, we check to see if AFS is active and if we have
1747 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1748 * if we can (and need to) extend the ticket into an AFS token. If
1749 * we don't do this, we run into potential problems if the user's
1750 * home directory is in AFS and it's not world-readable.
1753 if (options.kerberos_get_afs_token && k_hasafs() &&
1754 (s->authctxt->krb5_ctx != NULL)) {
1757 debug("Getting AFS token");
1761 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1762 krb5_afslog(s->authctxt->krb5_ctx,
1763 s->authctxt->krb5_fwd_ccache, cell, NULL);
1765 krb5_afslog_home(s->authctxt->krb5_ctx,
1766 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1772 /* User has authenticated, and if a ticket was going to be
1773 * passed we would have it. KRB5CCNAME should already be set.
1774 * Now try to get an AFS token using aklog.
1776 if (k_hasafs()) { /* Do we have AFS? */
1778 aklog_path = xstrdup(KPROGDIR);
1781 * Make sure it exists before we try to run it
1783 if (stat(aklog_path, &st) == 0) {
1784 debug("Running %s to get afs token.",aklog_path);
1787 debug("%s does not exist.",aklog_path);
1792 #endif /* AFS_KRB5 */
1794 #ifdef SESSION_HOOKS
1795 if (options.session_hooks_allow &&
1796 options.session_hooks_startup_cmd)
1798 execute_session_hook(options.session_hooks_startup_cmd,
1801 options.session_hooks_shutdown_cmd != NULL);
1805 /* Change current directory to the user's home directory. */
1806 if (chdir(pw->pw_dir) < 0) {
1807 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1808 pw->pw_dir, strerror(errno));
1809 #ifdef HAVE_LOGIN_CAP
1810 if (login_getcapbool(lc, "requirehome", 0))
1815 if (!options.use_login)
1816 do_rc_files(s, shell);
1818 /* restore SIGPIPE for child */
1819 signal(SIGPIPE, SIG_DFL);
1821 if (options.use_login) {
1822 launch_login(pw, hostname);
1826 /* Get the last component of the shell name. */
1827 if ((shell0 = strrchr(shell, '/')) != NULL)
1833 * If we have no command, execute the shell. In this case, the shell
1834 * name to be passed in argv[0] is preceded by '-' to indicate that
1835 * this is a login shell.
1840 /* Start the shell. Set initial character to '-'. */
1843 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1844 >= sizeof(argv0) - 1) {
1850 /* Execute the shell. */
1853 execve(shell, argv, environ);
1855 /* Executing the shell failed. */
1860 * Execute the command using the user's shell. This uses the -c
1861 * option to execute the command.
1863 argv[0] = (char *) shell0;
1865 argv[2] = (char *) command;
1867 execve(shell, argv, environ);
1876 static int did_init = 0;
1878 debug("session_new: init");
1879 for (i = 0; i < MAX_SESSIONS; i++) {
1880 sessions[i].used = 0;
1884 for (i = 0; i < MAX_SESSIONS; i++) {
1885 Session *s = &sessions[i];
1887 memset(s, 0, sizeof(*s));
1893 s->x11_chanids = NULL;
1894 debug("session_new: session %d", i);
1905 for (i = 0; i < MAX_SESSIONS; i++) {
1906 Session *s = &sessions[i];
1907 debug("dump: used %d session %d %p channel %d pid %ld",
1917 session_open(Authctxt *authctxt, int chanid)
1919 Session *s = session_new();
1920 debug("session_open: channel %d", chanid);
1922 error("no more sessions");
1925 s->authctxt = authctxt;
1926 s->pw = authctxt->pw;
1927 if (s->pw == NULL || !authctxt->valid)
1928 fatal("no user for session %d", s->self);
1929 debug("session_open: session %d: link with channel %d", s->self, chanid);
1935 session_by_tty(char *tty)
1938 for (i = 0; i < MAX_SESSIONS; i++) {
1939 Session *s = &sessions[i];
1940 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1941 debug("session_by_tty: session %d tty %s", i, tty);
1945 debug("session_by_tty: unknown tty %.100s", tty);
1951 session_by_channel(int id)
1954 for (i = 0; i < MAX_SESSIONS; i++) {
1955 Session *s = &sessions[i];
1956 if (s->used && s->chanid == id) {
1957 debug("session_by_channel: session %d channel %d", i, id);
1961 debug("session_by_channel: unknown channel %d", id);
1967 session_by_x11_channel(int id)
1971 for (i = 0; i < MAX_SESSIONS; i++) {
1972 Session *s = &sessions[i];
1974 if (s->x11_chanids == NULL || !s->used)
1976 for (j = 0; s->x11_chanids[j] != -1; j++) {
1977 if (s->x11_chanids[j] == id) {
1978 debug("session_by_x11_channel: session %d "
1979 "channel %d", s->self, id);
1984 debug("session_by_x11_channel: unknown channel %d", id);
1990 session_by_pid(pid_t pid)
1993 debug("session_by_pid: pid %ld", (long)pid);
1994 for (i = 0; i < MAX_SESSIONS; i++) {
1995 Session *s = &sessions[i];
1996 if (s->used && s->pid == pid)
1999 error("session_by_pid: unknown pid %ld", (long)pid);
2005 session_window_change_req(Session *s)
2007 s->col = packet_get_int();
2008 s->row = packet_get_int();
2009 s->xpixel = packet_get_int();
2010 s->ypixel = packet_get_int();
2012 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
2017 session_pty_req(Session *s)
2023 debug("Allocating a pty not permitted for this authentication.");
2026 if (s->ttyfd != -1) {
2027 packet_disconnect("Protocol error: you already have a pty.");
2031 s->term = packet_get_string(&len);
2034 s->col = packet_get_int();
2035 s->row = packet_get_int();
2037 s->row = packet_get_int();
2038 s->col = packet_get_int();
2040 s->xpixel = packet_get_int();
2041 s->ypixel = packet_get_int();
2043 if (strcmp(s->term, "") == 0) {
2048 /* Allocate a pty and open it. */
2049 debug("Allocating pty.");
2050 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
2056 error("session_pty_req: session %d alloc failed", s->self);
2059 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
2061 /* for SSH1 the tty modes length is not given */
2063 n_bytes = packet_remaining();
2064 tty_parse_modes(s->ttyfd, &n_bytes);
2067 pty_setowner(s->pw, s->tty);
2069 /* Set window size from the packet. */
2070 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
2073 session_proctitle(s);
2078 session_subsystem_req(Session *s)
2083 char *prog, *cmd, *subsys = packet_get_string(&len);
2087 logit("subsystem request for %.100s", subsys);
2089 for (i = 0; i < options.num_subsystems; i++) {
2090 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
2091 prog = options.subsystem_command[i];
2092 cmd = options.subsystem_args[i];
2093 if (stat(prog, &st) < 0) {
2094 error("subsystem: cannot stat %s: %s", prog,
2098 debug("subsystem: exec() %s", cmd);
2099 s->is_subsystem = 1;
2107 logit("subsystem request for %.100s failed, subsystem not found",
2115 session_x11_req(Session *s)
2119 if (s->auth_proto != NULL || s->auth_data != NULL) {
2120 error("session_x11_req: session %d: "
2121 "x11 forwarding already active", s->self);
2124 s->single_connection = packet_get_char();
2125 s->auth_proto = packet_get_string(NULL);
2126 s->auth_data = packet_get_string(NULL);
2127 s->screen = packet_get_int();
2130 success = session_setup_x11fwd(s);
2132 xfree(s->auth_proto);
2133 xfree(s->auth_data);
2134 s->auth_proto = NULL;
2135 s->auth_data = NULL;
2141 session_shell_req(Session *s)
2149 session_exec_req(Session *s)
2152 char *command = packet_get_string(&len);
2154 do_exec(s, command);
2160 session_break_req(Session *s)
2163 packet_get_int(); /* ignored */
2166 if (s->ttyfd == -1 ||
2167 tcsendbreak(s->ttyfd, 0) < 0)
2173 session_env_req(Session *s)
2176 u_int name_len, val_len, i;
2178 name = packet_get_string(&name_len);
2179 val = packet_get_string(&val_len);
2182 /* Don't set too many environment variables */
2183 if (s->num_env > 128) {
2184 debug2("Ignoring env request %s: too many env vars", name);
2188 for (i = 0; i < options.num_accept_env; i++) {
2189 if (match_pattern(name, options.accept_env[i])) {
2190 debug2("Setting env %d: %s=%s", s->num_env, name, val);
2191 s->env = xrealloc(s->env, s->num_env + 1,
2193 s->env[s->num_env].name = name;
2194 s->env[s->num_env].val = val;
2199 debug2("Ignoring env request %s: disallowed name", name);
2208 session_auth_agent_req(Session *s)
2210 static int called = 0;
2212 if (no_agent_forwarding_flag) {
2213 debug("session_auth_agent_req: no_agent_forwarding_flag");
2220 return auth_input_request_forwarding(s->pw);
2225 session_input_channel_req(Channel *c, const char *rtype)
2230 if ((s = session_by_channel(c->self)) == NULL) {
2231 logit("session_input_channel_req: no session %d req %.100s",
2235 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2238 * a session is in LARVAL state until a shell, a command
2239 * or a subsystem is executed
2241 if (c->type == SSH_CHANNEL_LARVAL) {
2242 if (strcmp(rtype, "shell") == 0) {
2243 success = session_shell_req(s);
2244 } else if (strcmp(rtype, "exec") == 0) {
2245 success = session_exec_req(s);
2246 } else if (strcmp(rtype, "pty-req") == 0) {
2247 success = session_pty_req(s);
2248 } else if (strcmp(rtype, "x11-req") == 0) {
2249 success = session_x11_req(s);
2250 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2251 success = session_auth_agent_req(s);
2252 } else if (strcmp(rtype, "subsystem") == 0) {
2253 success = session_subsystem_req(s);
2254 } else if (strcmp(rtype, "env") == 0) {
2255 success = session_env_req(s);
2258 if (strcmp(rtype, "window-change") == 0) {
2259 success = session_window_change_req(s);
2260 } else if (strcmp(rtype, "break") == 0) {
2261 success = session_break_req(s);
2268 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2271 fatal("session_set_fds: called for proto != 2.0");
2273 * now that have a child and a pipe to the child,
2274 * we can activate our channel and register the fd's
2276 if (s->chanid == -1)
2277 fatal("no channel for session %d", s->self);
2278 if(options.hpn_disabled)
2279 channel_set_fds(s->chanid,
2281 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2283 CHAN_SES_WINDOW_DEFAULT);
2285 channel_set_fds(s->chanid,
2287 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2289 options.hpn_buffer_size);
2293 * Function to perform pty cleanup. Also called if we get aborted abnormally
2294 * (e.g., due to a dropped connection).
2297 session_pty_cleanup2(Session *s)
2300 error("session_pty_cleanup: no session");
2306 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2308 /* Record that the user has logged out. */
2310 record_logout(s->pid, s->tty, s->pw->pw_name);
2312 /* Release the pseudo-tty. */
2314 pty_release(s->tty);
2317 * Close the server side of the socket pairs. We must do this after
2318 * the pty cleanup, so that another process doesn't get this pty
2319 * while we're still cleaning up.
2321 if (close(s->ptymaster) < 0)
2322 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2324 /* unlink pty from session */
2329 session_pty_cleanup(Session *s)
2331 PRIVSEP(session_pty_cleanup2(s));
2337 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2352 return "SIG@openssh.com";
2356 session_close_x11(int id)
2360 if ((c = channel_by_id(id)) == NULL) {
2361 debug("session_close_x11: x11 channel %d missing", id);
2363 /* Detach X11 listener */
2364 debug("session_close_x11: detach x11 channel %d", id);
2365 channel_cancel_cleanup(id);
2366 if (c->ostate != CHAN_OUTPUT_CLOSED)
2372 session_close_single_x11(int id, void *arg)
2377 debug3("session_close_single_x11: channel %d", id);
2378 channel_cancel_cleanup(id);
2379 if ((s = session_by_x11_channel(id)) == NULL)
2380 fatal("session_close_single_x11: no x11 channel %d", id);
2381 for (i = 0; s->x11_chanids[i] != -1; i++) {
2382 debug("session_close_single_x11: session %d: "
2383 "closing channel %d", s->self, s->x11_chanids[i]);
2385 * The channel "id" is already closing, but make sure we
2386 * close all of its siblings.
2388 if (s->x11_chanids[i] != id)
2389 session_close_x11(s->x11_chanids[i]);
2391 xfree(s->x11_chanids);
2392 s->x11_chanids = NULL;
2397 if (s->auth_proto) {
2398 xfree(s->auth_proto);
2399 s->auth_proto = NULL;
2402 xfree(s->auth_data);
2403 s->auth_data = NULL;
2405 if (s->auth_display) {
2406 xfree(s->auth_display);
2407 s->auth_display = NULL;
2412 session_exit_message(Session *s, int status)
2416 if ((c = channel_lookup(s->chanid)) == NULL)
2417 fatal("session_exit_message: session %d: no channel %d",
2418 s->self, s->chanid);
2419 debug("session_exit_message: session %d channel %d pid %ld",
2420 s->self, s->chanid, (long)s->pid);
2422 if (WIFEXITED(status)) {
2423 channel_request_start(s->chanid, "exit-status", 0);
2424 packet_put_int(WEXITSTATUS(status));
2426 } else if (WIFSIGNALED(status)) {
2427 channel_request_start(s->chanid, "exit-signal", 0);
2428 packet_put_cstring(sig2name(WTERMSIG(status)));
2430 packet_put_char(WCOREDUMP(status));
2431 #else /* WCOREDUMP */
2433 #endif /* WCOREDUMP */
2434 packet_put_cstring("");
2435 packet_put_cstring("");
2438 /* Some weird exit cause. Just exit. */
2439 packet_disconnect("wait returned status %04x.", status);
2442 /* disconnect channel */
2443 debug("session_exit_message: release channel %d", s->chanid);
2446 * Adjust cleanup callback attachment to send close messages when
2447 * the channel gets EOF. The session will be then be closed
2448 * by session_close_by_channel when the childs close their fds.
2450 channel_register_cleanup(c->self, session_close_by_channel, 1);
2453 * emulate a write failure with 'chan_write_failed', nobody will be
2454 * interested in data we write.
2455 * Note that we must not call 'chan_read_failed', since there could
2456 * be some more data waiting in the pipe.
2458 if (c->ostate != CHAN_OUTPUT_CLOSED)
2459 chan_write_failed(c);
2463 session_close(Session *s)
2467 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2469 session_pty_cleanup(s);
2475 xfree(s->x11_chanids);
2476 if (s->auth_display)
2477 xfree(s->auth_display);
2479 xfree(s->auth_data);
2481 xfree(s->auth_proto);
2483 if (s->env != NULL) {
2484 for (i = 0; i < s->num_env; i++) {
2485 xfree(s->env[i].name);
2486 xfree(s->env[i].val);
2490 session_proctitle(s);
2494 session_close_by_pid(pid_t pid, int status)
2496 Session *s = session_by_pid(pid);
2498 debug("session_close_by_pid: no session for pid %ld",
2502 if (s->chanid != -1)
2503 session_exit_message(s, status);
2505 session_pty_cleanup(s);
2510 * this is called when a channel dies before
2511 * the session 'child' itself dies
2514 session_close_by_channel(int id, void *arg)
2516 Session *s = session_by_channel(id);
2520 debug("session_close_by_channel: no session for id %d", id);
2523 debug("session_close_by_channel: channel %d child %ld",
2526 debug("session_close_by_channel: channel %d: has child", id);
2528 * delay detach of session, but release pty, since
2529 * the fd's to the child are already closed
2532 session_pty_cleanup(s);
2535 /* detach by removing callback */
2536 channel_cancel_cleanup(s->chanid);
2538 /* Close any X11 listeners associated with this session */
2539 if (s->x11_chanids != NULL) {
2540 for (i = 0; s->x11_chanids[i] != -1; i++) {
2541 session_close_x11(s->x11_chanids[i]);
2542 s->x11_chanids[i] = -1;
2551 session_destroy_all(void (*closefunc)(Session *))
2554 for (i = 0; i < MAX_SESSIONS; i++) {
2555 Session *s = &sessions[i];
2557 if (closefunc != NULL)
2566 session_tty_list(void)
2568 static char buf[1024];
2573 for (i = 0; i < MAX_SESSIONS; i++) {
2574 Session *s = &sessions[i];
2575 if (s->used && s->ttyfd != -1) {
2577 if (strncmp(s->tty, "/dev/", 5) != 0) {
2578 cp = strrchr(s->tty, '/');
2579 cp = (cp == NULL) ? s->tty : cp + 1;
2584 strlcat(buf, ",", sizeof buf);
2585 strlcat(buf, cp, sizeof buf);
2589 strlcpy(buf, "notty", sizeof buf);
2594 session_proctitle(Session *s)
2597 error("no user for session %d", s->self);
2599 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2603 session_setup_x11fwd(Session *s)
2606 char display[512], auth_display[512];
2607 char hostname[MAXHOSTNAMELEN];
2610 if (no_x11_forwarding_flag) {
2611 packet_send_debug("X11 forwarding disabled in user configuration file.");
2614 if (!options.x11_forwarding) {
2615 debug("X11 forwarding disabled in server configuration file.");
2618 if (!options.xauth_location ||
2619 (stat(options.xauth_location, &st) == -1)) {
2620 packet_send_debug("No xauth program; cannot forward with spoofing.");
2623 if (options.use_login) {
2624 packet_send_debug("X11 forwarding disabled; "
2625 "not compatible with UseLogin=yes.");
2628 if (s->display != NULL) {
2629 debug("X11 display already set.");
2632 if (x11_create_display_inet(options.x11_display_offset,
2633 options.x11_use_localhost, s->single_connection,
2634 &s->display_number, &s->x11_chanids,
2635 options.hpn_disabled, options.hpn_buffer_size) == -1) {
2636 debug("x11_create_display_inet failed.");
2639 for (i = 0; s->x11_chanids[i] != -1; i++) {
2640 channel_register_cleanup(s->x11_chanids[i],
2641 session_close_single_x11, 0);
2644 /* Set up a suitable value for the DISPLAY variable. */
2645 if (gethostname(hostname, sizeof(hostname)) < 0)
2646 fatal("gethostname: %.100s", strerror(errno));
2648 * auth_display must be used as the displayname when the
2649 * authorization entry is added with xauth(1). This will be
2650 * different than the DISPLAY string for localhost displays.
2652 if (options.x11_use_localhost) {
2653 snprintf(display, sizeof display, "localhost:%u.%u",
2654 s->display_number, s->screen);
2655 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2656 s->display_number, s->screen);
2657 s->display = xstrdup(display);
2658 s->auth_display = xstrdup(auth_display);
2660 #ifdef IPADDR_IN_DISPLAY
2662 struct in_addr my_addr;
2664 he = gethostbyname(hostname);
2666 error("Can't get IP address for X11 DISPLAY.");
2667 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2670 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2671 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2672 s->display_number, s->screen);
2674 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2675 s->display_number, s->screen);
2677 s->display = xstrdup(display);
2678 s->auth_display = xstrdup(display);
2685 do_authenticated2(Authctxt *authctxt)
2687 server_loop2(authctxt);
2691 do_cleanup(Authctxt *authctxt)
2693 static int called = 0;
2695 debug("do_cleanup");
2697 /* no cleanup if we're in the child for login shell */
2701 /* avoid double cleanup */
2706 if (authctxt == NULL)
2710 if (options.use_pam) {
2712 sshpam_thread_cleanup();
2716 if (!authctxt->authenticated)
2720 if (options.kerberos_ticket_cleanup &&
2722 krb5_cleanup_proc(authctxt);
2726 if (compat20 && options.gss_cleanup_creds)
2727 ssh_gssapi_cleanup_creds();
2730 /* remove agent socket */
2731 auth_sock_cleanup_proc(authctxt->pw);
2734 * Cleanup ptys/utmp only if privsep is disabled,
2735 * or if running in monitor.
2737 if (!use_privsep || mm_is_monitor())
2738 session_destroy_all(session_pty_cleanup2);