1 /* $OpenBSD: session.c,v 1.220 2006/10/09 23:36:11 djm Exp $ */
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * As far as I am concerned, the code I have written for this software
7 * can be used freely for any purpose. Any derived versions of this
8 * software must be clearly marked as such, and if the derived work is
9 * incompatible with the protocol description in the RFC file, it must be
10 * called by a name other than "ssh" or "Secure Shell".
12 * SSH2 support by Markus Friedl.
13 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 #include <sys/types.h>
39 #include <sys/param.h>
40 #ifdef HAVE_SYS_STAT_H
41 # include <sys/stat.h>
43 #include <sys/socket.h>
47 #include <arpa/inet.h>
80 #include "auth-options.h"
81 #include "pathnames.h"
85 #include "serverloop.h"
89 #include "monitor_wrap.h"
91 #if defined(KRB5) && defined(USE_AFS)
97 Session *session_new(void);
98 void session_set_fds(Session *, int, int, int);
99 void session_pty_cleanup(Session *);
100 void session_proctitle(Session *);
101 int session_setup_x11fwd(Session *);
102 void do_exec_pty(Session *, const char *);
103 void do_exec_no_pty(Session *, const char *);
104 void do_exec(Session *, const char *);
105 void do_login(Session *, const char *);
106 #ifdef LOGIN_NEEDS_UTMPX
107 static void do_pre_login(Session *s);
109 void do_child(Session *, const char *);
111 int check_quietlogin(Session *, const char *);
113 static void do_authenticated1(Authctxt *);
114 static void do_authenticated2(Authctxt *);
116 static int session_pty_req(Session *);
119 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",
1203 _PATH_STDPATH_WITH_SCP);
1205 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1206 #else /* HAVE_LOGIN_CAP */
1207 # ifndef HAVE_CYGWIN
1209 * There's no standard path on Windows. The path contains
1210 * important components pointing to the system directories,
1211 * needed for loading shared libraries. So the path better
1212 * remains intact here.
1214 # ifdef HAVE_ETC_DEFAULT_LOGIN
1215 read_etc_default_login(&env, &envsize, pw->pw_uid);
1216 path = child_get_env(env, "PATH");
1217 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1218 if (path == NULL || *path == '\0') {
1219 child_set_env(&env, &envsize, "PATH",
1220 s->pw->pw_uid == 0 ?
1221 SUPERUSER_PATH : _PATH_STDPATH_WITH_SCP);
1223 # endif /* HAVE_CYGWIN */
1224 #endif /* HAVE_LOGIN_CAP */
1226 snprintf(buf, sizeof buf, "%.200s/%.50s",
1227 _PATH_MAILDIR, pw->pw_name);
1228 child_set_env(&env, &envsize, "MAIL", buf);
1230 /* Normal systems set SHELL by default. */
1231 child_set_env(&env, &envsize, "SHELL", shell);
1234 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1236 #ifdef GSI /* GSI shared libs typically installed in non-system locations. */
1240 if ((cp = getenv("LD_LIBRARY_PATH")) != NULL)
1241 child_set_env(&env, &envsize, "LD_LIBRARY_PATH", cp);
1242 if ((cp = getenv("LIBPATH")) != NULL)
1243 child_set_env(&env, &envsize, "LIBPATH", cp);
1244 if ((cp = getenv("SHLIB_PATH")) != NULL)
1245 child_set_env(&env, &envsize, "SHLIB_PATH", cp);
1246 if ((cp = getenv("LD_LIBRARYN32_PATH")) != NULL)
1247 child_set_env(&env, &envsize, "LD_LIBRARYN32_PATH",cp);
1248 if ((cp = getenv("LD_LIBRARY64_PATH")) != NULL)
1249 child_set_env(&env, &envsize, "LD_LIBRARY64_PATH",cp);
1250 if ((cp = getenv("GLOBUS_LOCATION")) != NULL)
1251 child_set_env(&env, &envsize, "GLOBUS_LOCATION",cp);
1255 /* Set custom environment options from RSA authentication. */
1256 if (!options.use_login) {
1257 while (custom_environment) {
1258 struct envstring *ce = custom_environment;
1261 for (i = 0; str[i] != '=' && str[i]; i++)
1263 if (str[i] == '=') {
1265 child_set_env(&env, &envsize, str, str + i + 1);
1267 custom_environment = ce->next;
1273 /* SSH_CLIENT deprecated */
1274 snprintf(buf, sizeof buf, "%.50s %d %d",
1275 get_remote_ipaddr(), get_remote_port(), get_local_port());
1276 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1278 laddr = get_local_ipaddr(packet_get_connection_in());
1279 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1280 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1282 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1285 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1287 child_set_env(&env, &envsize, "TERM", s->term);
1289 child_set_env(&env, &envsize, "DISPLAY", s->display);
1290 if (original_command)
1291 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1295 if (cray_tmpdir[0] != '\0')
1296 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1297 #endif /* _UNICOS */
1300 * Since we clear KRB5CCNAME at startup, if it's set now then it
1301 * must have been set by a native authentication method (eg AIX or
1302 * SIA), so copy it to the child.
1307 if ((cp = getenv("KRB5CCNAME")) != NULL)
1308 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1315 if ((cp = getenv("AUTHSTATE")) != NULL)
1316 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1317 read_environment_file(&env, &envsize, "/etc/environment");
1321 if (s->authctxt->krb5_ccname)
1322 child_set_env(&env, &envsize, "KRB5CCNAME",
1323 s->authctxt->krb5_ccname);
1327 * Pull in any environment variables that may have
1330 if (options.use_pam) {
1333 p = fetch_pam_child_environment();
1334 copy_environment(p, &env, &envsize);
1335 free_pam_environment(p);
1337 p = fetch_pam_environment();
1338 copy_environment(p, &env, &envsize);
1339 free_pam_environment(p);
1341 #endif /* USE_PAM */
1343 if (auth_sock_name != NULL)
1344 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1347 /* read $HOME/.ssh/environment. */
1348 if (options.permit_user_env && !options.use_login) {
1349 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1350 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1351 read_environment_file(&env, &envsize, buf);
1354 /* dump the environment */
1355 fprintf(stderr, "Environment:\n");
1356 for (i = 0; env[i]; i++)
1357 fprintf(stderr, " %.200s\n", env[i]);
1363 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1364 * first in this order).
1367 do_rc_files(Session *s, const char *shell)
1375 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1377 /* ignore _PATH_SSH_USER_RC for subsystems */
1378 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1379 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1380 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1382 fprintf(stderr, "Running %s\n", cmd);
1383 f = popen(cmd, "w");
1386 fprintf(f, "%s %s\n", s->auth_proto,
1390 fprintf(stderr, "Could not run %s\n",
1392 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1393 snprintf(cmd, sizeof cmd, "%s %s", _PATH_BSHELL,
1394 _PATH_SSH_SYSTEM_RC);
1396 fprintf(stderr, "Running %s\n", cmd);
1397 f = popen(cmd, "w");
1400 fprintf(f, "%s %s\n", s->auth_proto,
1404 fprintf(stderr, "Could not run %s\n",
1405 _PATH_SSH_SYSTEM_RC);
1406 } else if (do_xauth && options.xauth_location != NULL) {
1407 /* Add authority data to .Xauthority if appropriate. */
1410 "Running %.500s remove %.100s\n",
1411 options.xauth_location, s->auth_display);
1413 "%.500s add %.100s %.100s %.100s\n",
1414 options.xauth_location, s->auth_display,
1415 s->auth_proto, s->auth_data);
1417 snprintf(cmd, sizeof cmd, "%s -q -",
1418 options.xauth_location);
1419 f = popen(cmd, "w");
1421 fprintf(f, "remove %s\n",
1423 fprintf(f, "add %s %s %s\n",
1424 s->auth_display, s->auth_proto,
1428 fprintf(stderr, "Could not run %s\n",
1435 do_nologin(struct passwd *pw)
1440 #ifdef HAVE_LOGIN_CAP
1441 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1442 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1443 _PATH_NOLOGIN), "r");
1446 f = fopen(_PATH_NOLOGIN, "r");
1449 /* /etc/nologin exists. Print its contents and exit. */
1450 logit("User %.100s not allowed because %s exists",
1451 pw->pw_name, _PATH_NOLOGIN);
1452 while (fgets(buf, sizeof(buf), f))
1460 /* Set login name, uid, gid, and groups. */
1462 do_setusercontext(struct passwd *pw)
1465 if (getuid() == 0 || geteuid() == 0)
1466 #endif /* HAVE_CYGWIN */
1469 #ifdef HAVE_SETPCRED
1470 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1471 fatal("Failed to set process credentials");
1472 #endif /* HAVE_SETPCRED */
1473 #ifdef HAVE_LOGIN_CAP
1478 if (options.gss_authentication) {
1479 temporarily_use_uid(pw);
1480 ssh_gssapi_storecreds();
1485 if (options.use_pam) {
1489 # endif /* USE_PAM */
1490 if (setusercontext(lc, pw, pw->pw_uid,
1491 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1492 perror("unable to set user context");
1496 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1497 /* Sets login uid for accounting */
1498 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1499 error("setluid: %s", strerror(errno));
1500 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1502 if (setlogin(pw->pw_name) < 0)
1503 error("setlogin failed: %s", strerror(errno));
1504 if (setgid(pw->pw_gid) < 0) {
1508 /* Initialize the group list. */
1509 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1510 perror("initgroups");
1515 if (options.gss_authentication) {
1516 temporarily_use_uid(pw);
1517 ssh_gssapi_storecreds();
1523 * PAM credentials may take the form of supplementary groups.
1524 * These will have been wiped by the above initgroups() call.
1525 * Reestablish them here.
1527 if (options.use_pam) {
1531 # endif /* USE_PAM */
1532 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1533 irix_setusercontext(pw);
1534 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1538 #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
1539 if (set_id(pw->pw_name) != 0) {
1542 #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
1543 /* Permanently switch to the desired uid. */
1544 permanently_set_uid(pw);
1551 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1552 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1555 ssh_selinux_setup_exec_context(pw->pw_name);
1560 do_pwchange(Session *s)
1563 fprintf(stderr, "WARNING: Your password has expired.\n");
1564 if (s->ttyfd != -1) {
1566 "You must change your password now and login again!\n");
1567 #ifdef PASSWD_NEEDS_USERNAME
1568 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1571 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1576 "Password change required but no TTY available.\n");
1582 launch_login(struct passwd *pw, const char *hostname)
1584 /* Launch login(1). */
1586 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1587 #ifdef xxxLOGIN_NEEDS_TERM
1588 (s->term ? s->term : "unknown"),
1589 #endif /* LOGIN_NEEDS_TERM */
1590 #ifdef LOGIN_NO_ENDOPT
1591 "-p", "-f", pw->pw_name, (char *)NULL);
1593 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1596 /* Login couldn't be executed, die. */
1603 child_close_fds(void)
1607 if (packet_get_connection_in() == packet_get_connection_out())
1608 close(packet_get_connection_in());
1610 close(packet_get_connection_in());
1611 close(packet_get_connection_out());
1614 * Close all descriptors related to channels. They will still remain
1615 * open in the parent.
1617 /* XXX better use close-on-exec? -markus */
1618 channel_close_all();
1621 * Close any extra file descriptors. Note that there may still be
1622 * descriptors left by system functions. They will be closed later.
1627 * Close any extra open file descriptors so that we don't have them
1628 * hanging around in clients. Note that we want to do this after
1629 * initgroups, because at least on Solaris 2.3 it leaves file
1632 for (i = 3; i < 64; i++)
1637 * Performs common processing for the child, such as setting up the
1638 * environment, closing extra file descriptors, setting the user and group
1639 * ids, and executing the command or shell.
1642 do_child(Session *s, const char *command)
1644 extern char **environ;
1647 const char *shell, *shell0, *hostname = NULL;
1648 struct passwd *pw = s->pw;
1651 /* Default place to look for aklog. */
1653 #define KPROGDIR AKLOG_PATH
1655 #define KPROGDIR "/usr/bin/aklog"
1656 #endif /* AKLOG_PATH */
1660 #endif /* AFS_KRB5 */
1662 /* remove hostkey from the child's memory */
1663 destroy_sensitive_data();
1665 /* Force a password change */
1666 if (s->authctxt->force_pwchange) {
1667 do_setusercontext(pw);
1673 /* login(1) is only called if we execute the login shell */
1674 if (options.use_login && command != NULL)
1675 options.use_login = 0;
1678 cray_setup(pw->pw_uid, pw->pw_name, command);
1679 #endif /* _UNICOS */
1682 * Login(1) does this as well, and it needs uid 0 for the "-h"
1683 * switch, so we let login(1) to this for us.
1685 if (!options.use_login) {
1687 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1688 if (!check_quietlogin(s, command))
1690 #else /* HAVE_OSF_SIA */
1691 /* When PAM is enabled we rely on it to do the nologin check */
1692 if (!options.use_pam)
1694 do_setusercontext(pw);
1696 * PAM session modules in do_setusercontext may have
1697 * generated messages, so if this in an interactive
1698 * login then display them too.
1700 if (!check_quietlogin(s, command))
1702 #endif /* HAVE_OSF_SIA */
1706 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1707 debug3("PAM session not opened, exiting");
1714 * Get the shell from the password data. An empty shell field is
1715 * legal, and means /bin/sh.
1717 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1720 * Make sure $SHELL points to the shell from the password file,
1721 * even if shell is overridden from login.conf
1723 env = do_setup_env(s, shell);
1725 #ifdef HAVE_LOGIN_CAP
1726 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1729 /* we have to stash the hostname before we close our socket. */
1730 if (options.use_login)
1731 hostname = get_remote_name_or_ip(utmp_len,
1734 * Close the connection descriptors; note that this is the child, and
1735 * the server will still have the socket open, and it is important
1736 * that we do not shutdown it. Note that the descriptors cannot be
1737 * closed before building the environment, as we call
1738 * get_remote_ipaddr there.
1743 * Must take new environment into use so that .ssh/rc,
1744 * /etc/ssh/sshrc and xauth are run in the proper environment.
1748 #if defined(KRB5) && defined(USE_AFS)
1750 * At this point, we check to see if AFS is active and if we have
1751 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1752 * if we can (and need to) extend the ticket into an AFS token. If
1753 * we don't do this, we run into potential problems if the user's
1754 * home directory is in AFS and it's not world-readable.
1757 if (options.kerberos_get_afs_token && k_hasafs() &&
1758 (s->authctxt->krb5_ctx != NULL)) {
1761 debug("Getting AFS token");
1765 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1766 krb5_afslog(s->authctxt->krb5_ctx,
1767 s->authctxt->krb5_fwd_ccache, cell, NULL);
1769 krb5_afslog_home(s->authctxt->krb5_ctx,
1770 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1776 /* User has authenticated, and if a ticket was going to be
1777 * passed we would have it. KRB5CCNAME should already be set.
1778 * Now try to get an AFS token using aklog.
1780 if (k_hasafs()) { /* Do we have AFS? */
1782 aklog_path = xstrdup(KPROGDIR);
1785 * Make sure it exists before we try to run it
1787 if (stat(aklog_path, &st) == 0) {
1788 debug("Running %s to get afs token.",aklog_path);
1791 debug("%s does not exist.",aklog_path);
1796 #endif /* AFS_KRB5 */
1798 #ifdef SESSION_HOOKS
1799 if (options.session_hooks_allow &&
1800 options.session_hooks_startup_cmd)
1802 execute_session_hook(options.session_hooks_startup_cmd,
1805 options.session_hooks_shutdown_cmd != NULL);
1809 /* Change current directory to the user's home directory. */
1810 if (chdir(pw->pw_dir) < 0) {
1811 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1812 pw->pw_dir, strerror(errno));
1813 #ifdef HAVE_LOGIN_CAP
1814 if (login_getcapbool(lc, "requirehome", 0))
1819 if (!options.use_login)
1820 do_rc_files(s, shell);
1822 /* restore SIGPIPE for child */
1823 signal(SIGPIPE, SIG_DFL);
1825 if (options.use_login) {
1826 launch_login(pw, hostname);
1830 /* Get the last component of the shell name. */
1831 if ((shell0 = strrchr(shell, '/')) != NULL)
1837 * If we have no command, execute the shell. In this case, the shell
1838 * name to be passed in argv[0] is preceded by '-' to indicate that
1839 * this is a login shell.
1844 /* Start the shell. Set initial character to '-'. */
1847 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1848 >= sizeof(argv0) - 1) {
1854 /* Execute the shell. */
1857 execve(shell, argv, environ);
1859 /* Executing the shell failed. */
1864 * Execute the command using the user's shell. This uses the -c
1865 * option to execute the command.
1867 argv[0] = (char *) shell0;
1869 argv[2] = (char *) command;
1871 execve(shell, argv, environ);
1880 static int did_init = 0;
1882 debug("session_new: init");
1883 for (i = 0; i < MAX_SESSIONS; i++) {
1884 sessions[i].used = 0;
1888 for (i = 0; i < MAX_SESSIONS; i++) {
1889 Session *s = &sessions[i];
1891 memset(s, 0, sizeof(*s));
1897 s->x11_chanids = NULL;
1898 debug("session_new: session %d", i);
1909 for (i = 0; i < MAX_SESSIONS; i++) {
1910 Session *s = &sessions[i];
1911 debug("dump: used %d session %d %p channel %d pid %ld",
1921 session_open(Authctxt *authctxt, int chanid)
1923 Session *s = session_new();
1924 debug("session_open: channel %d", chanid);
1926 error("no more sessions");
1929 s->authctxt = authctxt;
1930 s->pw = authctxt->pw;
1931 if (s->pw == NULL || !authctxt->valid)
1932 fatal("no user for session %d", s->self);
1933 debug("session_open: session %d: link with channel %d", s->self, chanid);
1939 session_by_tty(char *tty)
1942 for (i = 0; i < MAX_SESSIONS; i++) {
1943 Session *s = &sessions[i];
1944 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1945 debug("session_by_tty: session %d tty %s", i, tty);
1949 debug("session_by_tty: unknown tty %.100s", tty);
1955 session_by_channel(int id)
1958 for (i = 0; i < MAX_SESSIONS; i++) {
1959 Session *s = &sessions[i];
1960 if (s->used && s->chanid == id) {
1961 debug("session_by_channel: session %d channel %d", i, id);
1965 debug("session_by_channel: unknown channel %d", id);
1971 session_by_x11_channel(int id)
1975 for (i = 0; i < MAX_SESSIONS; i++) {
1976 Session *s = &sessions[i];
1978 if (s->x11_chanids == NULL || !s->used)
1980 for (j = 0; s->x11_chanids[j] != -1; j++) {
1981 if (s->x11_chanids[j] == id) {
1982 debug("session_by_x11_channel: session %d "
1983 "channel %d", s->self, id);
1988 debug("session_by_x11_channel: unknown channel %d", id);
1994 session_by_pid(pid_t pid)
1997 debug("session_by_pid: pid %ld", (long)pid);
1998 for (i = 0; i < MAX_SESSIONS; i++) {
1999 Session *s = &sessions[i];
2000 if (s->used && s->pid == pid)
2003 error("session_by_pid: unknown pid %ld", (long)pid);
2009 session_window_change_req(Session *s)
2011 s->col = packet_get_int();
2012 s->row = packet_get_int();
2013 s->xpixel = packet_get_int();
2014 s->ypixel = packet_get_int();
2016 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
2021 session_pty_req(Session *s)
2027 debug("Allocating a pty not permitted for this authentication.");
2030 if (s->ttyfd != -1) {
2031 packet_disconnect("Protocol error: you already have a pty.");
2035 s->term = packet_get_string(&len);
2038 s->col = packet_get_int();
2039 s->row = packet_get_int();
2041 s->row = packet_get_int();
2042 s->col = packet_get_int();
2044 s->xpixel = packet_get_int();
2045 s->ypixel = packet_get_int();
2047 if (strcmp(s->term, "") == 0) {
2052 /* Allocate a pty and open it. */
2053 debug("Allocating pty.");
2054 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
2060 error("session_pty_req: session %d alloc failed", s->self);
2063 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
2065 /* for SSH1 the tty modes length is not given */
2067 n_bytes = packet_remaining();
2068 tty_parse_modes(s->ttyfd, &n_bytes);
2071 pty_setowner(s->pw, s->tty);
2073 /* Set window size from the packet. */
2074 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
2077 session_proctitle(s);
2082 session_subsystem_req(Session *s)
2087 char *prog, *cmd, *subsys = packet_get_string(&len);
2091 logit("subsystem request for %.100s", subsys);
2093 for (i = 0; i < options.num_subsystems; i++) {
2094 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
2095 prog = options.subsystem_command[i];
2096 cmd = options.subsystem_args[i];
2097 if (stat(prog, &st) < 0) {
2098 error("subsystem: cannot stat %s: %s", prog,
2102 debug("subsystem: exec() %s", cmd);
2103 s->is_subsystem = 1;
2111 logit("subsystem request for %.100s failed, subsystem not found",
2119 session_x11_req(Session *s)
2123 if (s->auth_proto != NULL || s->auth_data != NULL) {
2124 error("session_x11_req: session %d: "
2125 "x11 forwarding already active", s->self);
2128 s->single_connection = packet_get_char();
2129 s->auth_proto = packet_get_string(NULL);
2130 s->auth_data = packet_get_string(NULL);
2131 s->screen = packet_get_int();
2134 success = session_setup_x11fwd(s);
2136 xfree(s->auth_proto);
2137 xfree(s->auth_data);
2138 s->auth_proto = NULL;
2139 s->auth_data = NULL;
2145 session_shell_req(Session *s)
2153 session_exec_req(Session *s)
2156 char *command = packet_get_string(&len);
2158 do_exec(s, command);
2164 session_break_req(Session *s)
2167 packet_get_int(); /* ignored */
2170 if (s->ttyfd == -1 ||
2171 tcsendbreak(s->ttyfd, 0) < 0)
2177 session_env_req(Session *s)
2180 u_int name_len, val_len, i;
2182 name = packet_get_string(&name_len);
2183 val = packet_get_string(&val_len);
2186 /* Don't set too many environment variables */
2187 if (s->num_env > 128) {
2188 debug2("Ignoring env request %s: too many env vars", name);
2192 for (i = 0; i < options.num_accept_env; i++) {
2193 if (match_pattern(name, options.accept_env[i])) {
2194 debug2("Setting env %d: %s=%s", s->num_env, name, val);
2195 s->env = xrealloc(s->env, s->num_env + 1,
2197 s->env[s->num_env].name = name;
2198 s->env[s->num_env].val = val;
2203 debug2("Ignoring env request %s: disallowed name", name);
2212 session_auth_agent_req(Session *s)
2214 static int called = 0;
2216 if (no_agent_forwarding_flag) {
2217 debug("session_auth_agent_req: no_agent_forwarding_flag");
2224 return auth_input_request_forwarding(s->pw);
2229 session_input_channel_req(Channel *c, const char *rtype)
2234 if ((s = session_by_channel(c->self)) == NULL) {
2235 logit("session_input_channel_req: no session %d req %.100s",
2239 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2242 * a session is in LARVAL state until a shell, a command
2243 * or a subsystem is executed
2245 if (c->type == SSH_CHANNEL_LARVAL) {
2246 if (strcmp(rtype, "shell") == 0) {
2247 success = session_shell_req(s);
2248 } else if (strcmp(rtype, "exec") == 0) {
2249 success = session_exec_req(s);
2250 } else if (strcmp(rtype, "pty-req") == 0) {
2251 success = session_pty_req(s);
2252 } else if (strcmp(rtype, "x11-req") == 0) {
2253 success = session_x11_req(s);
2254 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2255 success = session_auth_agent_req(s);
2256 } else if (strcmp(rtype, "subsystem") == 0) {
2257 success = session_subsystem_req(s);
2258 } else if (strcmp(rtype, "env") == 0) {
2259 success = session_env_req(s);
2262 if (strcmp(rtype, "window-change") == 0) {
2263 success = session_window_change_req(s);
2264 } else if (strcmp(rtype, "break") == 0) {
2265 success = session_break_req(s);
2272 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2275 fatal("session_set_fds: called for proto != 2.0");
2277 * now that have a child and a pipe to the child,
2278 * we can activate our channel and register the fd's
2280 if (s->chanid == -1)
2281 fatal("no channel for session %d", s->self);
2282 if(options.hpn_disabled)
2283 channel_set_fds(s->chanid,
2285 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2287 CHAN_SES_WINDOW_DEFAULT);
2289 channel_set_fds(s->chanid,
2291 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2293 options.hpn_buffer_size);
2297 * Function to perform pty cleanup. Also called if we get aborted abnormally
2298 * (e.g., due to a dropped connection).
2301 session_pty_cleanup2(Session *s)
2304 error("session_pty_cleanup: no session");
2310 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2312 /* Record that the user has logged out. */
2314 record_logout(s->pid, s->tty, s->pw->pw_name);
2316 /* Release the pseudo-tty. */
2318 pty_release(s->tty);
2321 * Close the server side of the socket pairs. We must do this after
2322 * the pty cleanup, so that another process doesn't get this pty
2323 * while we're still cleaning up.
2325 if (close(s->ptymaster) < 0)
2326 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2328 /* unlink pty from session */
2333 session_pty_cleanup(Session *s)
2335 PRIVSEP(session_pty_cleanup2(s));
2341 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2356 return "SIG@openssh.com";
2360 session_close_x11(int id)
2364 if ((c = channel_by_id(id)) == NULL) {
2365 debug("session_close_x11: x11 channel %d missing", id);
2367 /* Detach X11 listener */
2368 debug("session_close_x11: detach x11 channel %d", id);
2369 channel_cancel_cleanup(id);
2370 if (c->ostate != CHAN_OUTPUT_CLOSED)
2376 session_close_single_x11(int id, void *arg)
2381 debug3("session_close_single_x11: channel %d", id);
2382 channel_cancel_cleanup(id);
2383 if ((s = session_by_x11_channel(id)) == NULL)
2384 fatal("session_close_single_x11: no x11 channel %d", id);
2385 for (i = 0; s->x11_chanids[i] != -1; i++) {
2386 debug("session_close_single_x11: session %d: "
2387 "closing channel %d", s->self, s->x11_chanids[i]);
2389 * The channel "id" is already closing, but make sure we
2390 * close all of its siblings.
2392 if (s->x11_chanids[i] != id)
2393 session_close_x11(s->x11_chanids[i]);
2395 xfree(s->x11_chanids);
2396 s->x11_chanids = NULL;
2401 if (s->auth_proto) {
2402 xfree(s->auth_proto);
2403 s->auth_proto = NULL;
2406 xfree(s->auth_data);
2407 s->auth_data = NULL;
2409 if (s->auth_display) {
2410 xfree(s->auth_display);
2411 s->auth_display = NULL;
2416 session_exit_message(Session *s, int status)
2420 if ((c = channel_lookup(s->chanid)) == NULL)
2421 fatal("session_exit_message: session %d: no channel %d",
2422 s->self, s->chanid);
2423 debug("session_exit_message: session %d channel %d pid %ld",
2424 s->self, s->chanid, (long)s->pid);
2426 if (WIFEXITED(status)) {
2427 channel_request_start(s->chanid, "exit-status", 0);
2428 packet_put_int(WEXITSTATUS(status));
2430 } else if (WIFSIGNALED(status)) {
2431 channel_request_start(s->chanid, "exit-signal", 0);
2432 packet_put_cstring(sig2name(WTERMSIG(status)));
2434 packet_put_char(WCOREDUMP(status));
2435 #else /* WCOREDUMP */
2437 #endif /* WCOREDUMP */
2438 packet_put_cstring("");
2439 packet_put_cstring("");
2442 /* Some weird exit cause. Just exit. */
2443 packet_disconnect("wait returned status %04x.", status);
2446 /* disconnect channel */
2447 debug("session_exit_message: release channel %d", s->chanid);
2450 * Adjust cleanup callback attachment to send close messages when
2451 * the channel gets EOF. The session will be then be closed
2452 * by session_close_by_channel when the childs close their fds.
2454 channel_register_cleanup(c->self, session_close_by_channel, 1);
2457 * emulate a write failure with 'chan_write_failed', nobody will be
2458 * interested in data we write.
2459 * Note that we must not call 'chan_read_failed', since there could
2460 * be some more data waiting in the pipe.
2462 if (c->ostate != CHAN_OUTPUT_CLOSED)
2463 chan_write_failed(c);
2467 session_close(Session *s)
2471 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2473 session_pty_cleanup(s);
2479 xfree(s->x11_chanids);
2480 if (s->auth_display)
2481 xfree(s->auth_display);
2483 xfree(s->auth_data);
2485 xfree(s->auth_proto);
2487 if (s->env != NULL) {
2488 for (i = 0; i < s->num_env; i++) {
2489 xfree(s->env[i].name);
2490 xfree(s->env[i].val);
2494 session_proctitle(s);
2498 session_close_by_pid(pid_t pid, int status)
2500 Session *s = session_by_pid(pid);
2502 debug("session_close_by_pid: no session for pid %ld",
2506 if (s->chanid != -1)
2507 session_exit_message(s, status);
2509 session_pty_cleanup(s);
2514 * this is called when a channel dies before
2515 * the session 'child' itself dies
2518 session_close_by_channel(int id, void *arg)
2520 Session *s = session_by_channel(id);
2524 debug("session_close_by_channel: no session for id %d", id);
2527 debug("session_close_by_channel: channel %d child %ld",
2530 debug("session_close_by_channel: channel %d: has child", id);
2532 * delay detach of session, but release pty, since
2533 * the fd's to the child are already closed
2536 session_pty_cleanup(s);
2539 /* detach by removing callback */
2540 channel_cancel_cleanup(s->chanid);
2542 /* Close any X11 listeners associated with this session */
2543 if (s->x11_chanids != NULL) {
2544 for (i = 0; s->x11_chanids[i] != -1; i++) {
2545 session_close_x11(s->x11_chanids[i]);
2546 s->x11_chanids[i] = -1;
2555 session_destroy_all(void (*closefunc)(Session *))
2558 for (i = 0; i < MAX_SESSIONS; i++) {
2559 Session *s = &sessions[i];
2561 if (closefunc != NULL)
2570 session_tty_list(void)
2572 static char buf[1024];
2577 for (i = 0; i < MAX_SESSIONS; i++) {
2578 Session *s = &sessions[i];
2579 if (s->used && s->ttyfd != -1) {
2581 if (strncmp(s->tty, "/dev/", 5) != 0) {
2582 cp = strrchr(s->tty, '/');
2583 cp = (cp == NULL) ? s->tty : cp + 1;
2588 strlcat(buf, ",", sizeof buf);
2589 strlcat(buf, cp, sizeof buf);
2593 strlcpy(buf, "notty", sizeof buf);
2598 session_proctitle(Session *s)
2601 error("no user for session %d", s->self);
2603 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2607 session_setup_x11fwd(Session *s)
2610 char display[512], auth_display[512];
2611 char hostname[MAXHOSTNAMELEN];
2614 if (no_x11_forwarding_flag) {
2615 packet_send_debug("X11 forwarding disabled in user configuration file.");
2618 if (!options.x11_forwarding) {
2619 debug("X11 forwarding disabled in server configuration file.");
2622 if (!options.xauth_location ||
2623 (stat(options.xauth_location, &st) == -1)) {
2624 packet_send_debug("No xauth program; cannot forward with spoofing.");
2627 if (options.use_login) {
2628 packet_send_debug("X11 forwarding disabled; "
2629 "not compatible with UseLogin=yes.");
2632 if (s->display != NULL) {
2633 debug("X11 display already set.");
2636 if (x11_create_display_inet(options.x11_display_offset,
2637 options.x11_use_localhost, s->single_connection,
2638 &s->display_number, &s->x11_chanids,
2639 options.hpn_disabled, options.hpn_buffer_size) == -1) {
2640 debug("x11_create_display_inet failed.");
2643 for (i = 0; s->x11_chanids[i] != -1; i++) {
2644 channel_register_cleanup(s->x11_chanids[i],
2645 session_close_single_x11, 0);
2648 /* Set up a suitable value for the DISPLAY variable. */
2649 if (gethostname(hostname, sizeof(hostname)) < 0)
2650 fatal("gethostname: %.100s", strerror(errno));
2652 * auth_display must be used as the displayname when the
2653 * authorization entry is added with xauth(1). This will be
2654 * different than the DISPLAY string for localhost displays.
2656 if (options.x11_use_localhost) {
2657 snprintf(display, sizeof display, "localhost:%u.%u",
2658 s->display_number, s->screen);
2659 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2660 s->display_number, s->screen);
2661 s->display = xstrdup(display);
2662 s->auth_display = xstrdup(auth_display);
2664 #ifdef IPADDR_IN_DISPLAY
2666 struct in_addr my_addr;
2668 he = gethostbyname(hostname);
2670 error("Can't get IP address for X11 DISPLAY.");
2671 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2674 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2675 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2676 s->display_number, s->screen);
2678 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2679 s->display_number, s->screen);
2681 s->display = xstrdup(display);
2682 s->auth_display = xstrdup(display);
2689 do_authenticated2(Authctxt *authctxt)
2691 server_loop2(authctxt);
2695 do_cleanup(Authctxt *authctxt)
2697 static int called = 0;
2699 debug("do_cleanup");
2701 /* no cleanup if we're in the child for login shell */
2705 /* avoid double cleanup */
2710 if (authctxt == NULL || !authctxt->authenticated)
2713 if (options.kerberos_ticket_cleanup &&
2715 krb5_cleanup_proc(authctxt);
2719 if (compat20 && options.gss_cleanup_creds)
2720 ssh_gssapi_cleanup_creds();
2724 if (options.use_pam) {
2726 sshpam_thread_cleanup();
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);