1 /* $OpenBSD: session.c,v 1.209 2006/07/11 20:07:25 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 #ifdef HAVE_SYS_STAT_H
40 # include <sys/stat.h>
42 #include <sys/socket.h>
53 #include <arpa/inet.h>
68 #include "auth-options.h"
69 #include "pathnames.h"
73 #include "serverloop.h"
77 #include "monitor_wrap.h"
79 #if defined(KRB5) && defined(USE_AFS)
89 Session *session_new(void);
90 void session_set_fds(Session *, int, int, int);
91 void session_pty_cleanup(Session *);
92 void session_proctitle(Session *);
93 int session_setup_x11fwd(Session *);
94 void do_exec_pty(Session *, const char *);
95 void do_exec_no_pty(Session *, const char *);
96 void do_exec(Session *, const char *);
97 void do_login(Session *, const char *);
98 #ifdef LOGIN_NEEDS_UTMPX
99 static void do_pre_login(Session *s);
101 void do_child(Session *, const char *);
103 int check_quietlogin(Session *, const char *);
105 static void do_authenticated1(Authctxt *);
106 static void do_authenticated2(Authctxt *);
108 static int session_pty_req(Session *);
111 extern ServerOptions options;
112 extern char *__progname;
113 extern int log_stderr;
114 extern int debug_flag;
115 extern u_int utmp_len;
116 extern int startup_pipe;
117 extern void destroy_sensitive_data(void);
118 extern Buffer loginmsg;
120 /* original command from peer. */
121 const char *original_command = NULL;
124 #define MAX_SESSIONS 10
125 Session sessions[MAX_SESSIONS];
127 #ifdef HAVE_LOGIN_CAP
131 static int is_child = 0;
133 /* Name and directory of socket for authentication agent forwarding. */
134 static char *auth_sock_name = NULL;
135 static char *auth_sock_dir = NULL;
137 /* removes the agent forwarding socket */
140 auth_sock_cleanup_proc(struct passwd *pw)
142 if (auth_sock_name != NULL) {
143 temporarily_use_uid(pw);
144 unlink(auth_sock_name);
145 rmdir(auth_sock_dir);
146 auth_sock_name = NULL;
152 auth_input_request_forwarding(struct passwd * pw)
156 struct sockaddr_un sunaddr;
158 if (auth_sock_name != NULL) {
159 error("authentication forwarding requested twice.");
163 /* Temporarily drop privileged uid for mkdir/bind. */
164 temporarily_use_uid(pw);
166 /* Allocate a buffer for the socket name, and format the name. */
167 auth_sock_name = xmalloc(MAXPATHLEN);
168 auth_sock_dir = xmalloc(MAXPATHLEN);
169 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
171 /* Create private directory for socket */
172 if (mkdtemp(auth_sock_dir) == NULL) {
173 packet_send_debug("Agent forwarding disabled: "
174 "mkdtemp() failed: %.100s", strerror(errno));
176 xfree(auth_sock_name);
177 xfree(auth_sock_dir);
178 auth_sock_name = NULL;
179 auth_sock_dir = NULL;
182 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
183 auth_sock_dir, (long) getpid());
185 /* Create the socket. */
186 sock = socket(AF_UNIX, SOCK_STREAM, 0);
188 packet_disconnect("socket: %.100s", strerror(errno));
190 /* Bind it to the name. */
191 memset(&sunaddr, 0, sizeof(sunaddr));
192 sunaddr.sun_family = AF_UNIX;
193 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
195 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0)
196 packet_disconnect("bind: %.100s", strerror(errno));
198 /* Restore the privileged uid. */
201 /* Start listening on the socket. */
202 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
203 packet_disconnect("listen: %.100s", strerror(errno));
205 /* Allocate a channel for the authentication agent socket. */
206 nc = channel_new("auth socket",
207 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
208 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
209 0, "auth socket", 1);
210 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
215 display_loginmsg(void)
217 if (buffer_len(&loginmsg) > 0) {
218 buffer_append(&loginmsg, "\0", 1);
219 printf("%s", (char *)buffer_ptr(&loginmsg));
220 buffer_clear(&loginmsg);
225 do_authenticated(Authctxt *authctxt)
227 setproctitle("%s", authctxt->pw->pw_name);
229 /* setup the channel layer */
230 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
231 channel_permit_all_opens();
234 do_authenticated2(authctxt);
236 do_authenticated1(authctxt);
238 do_cleanup(authctxt);
242 * Prepares for an interactive session. This is called after the user has
243 * been successfully authenticated. During this message exchange, pseudo
244 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
245 * are requested, etc.
248 do_authenticated1(Authctxt *authctxt)
252 int success, type, screen_flag;
253 int enable_compression_after_reply = 0;
254 u_int proto_len, data_len, dlen, compression_level = 0;
258 error("no more sessions");
261 s->authctxt = authctxt;
262 s->pw = authctxt->pw;
265 * We stay in this loop until the client requests to execute a shell
271 /* Get a packet from the client. */
272 type = packet_read();
274 /* Process the packet. */
276 case SSH_CMSG_REQUEST_COMPRESSION:
277 compression_level = packet_get_int();
279 if (compression_level < 1 || compression_level > 9) {
280 packet_send_debug("Received invalid compression level %d.",
284 if (options.compression == COMP_NONE) {
285 debug2("compression disabled");
288 /* Enable compression after we have responded with SUCCESS. */
289 enable_compression_after_reply = 1;
293 case SSH_CMSG_REQUEST_PTY:
294 success = session_pty_req(s);
297 case SSH_CMSG_X11_REQUEST_FORWARDING:
298 s->auth_proto = packet_get_string(&proto_len);
299 s->auth_data = packet_get_string(&data_len);
301 screen_flag = packet_get_protocol_flags() &
302 SSH_PROTOFLAG_SCREEN_NUMBER;
303 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
305 if (packet_remaining() == 4) {
307 debug2("Buggy client: "
308 "X11 screen flag missing");
309 s->screen = packet_get_int();
314 success = session_setup_x11fwd(s);
316 xfree(s->auth_proto);
318 s->auth_proto = NULL;
323 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
324 if (no_agent_forwarding_flag || compat13) {
325 debug("Authentication agent forwarding not permitted for this authentication.");
328 debug("Received authentication agent forwarding request.");
329 success = auth_input_request_forwarding(s->pw);
332 case SSH_CMSG_PORT_FORWARD_REQUEST:
333 if (no_port_forwarding_flag) {
334 debug("Port forwarding not permitted for this authentication.");
337 if (!options.allow_tcp_forwarding) {
338 debug("Port forwarding not permitted.");
341 debug("Received TCP/IP port forwarding request.");
342 if (channel_input_port_forward_request(s->pw->pw_uid == 0,
343 options.gateway_ports) < 0) {
344 debug("Port forwarding failed.");
350 case SSH_CMSG_MAX_PACKET_SIZE:
351 if (packet_set_maxsize(packet_get_int()) > 0)
355 case SSH_CMSG_EXEC_SHELL:
356 case SSH_CMSG_EXEC_CMD:
357 if (type == SSH_CMSG_EXEC_CMD) {
358 command = packet_get_string(&dlen);
359 debug("Exec command '%.500s'", command);
371 * Any unknown messages in this phase are ignored,
372 * and a failure message is returned.
374 logit("Unknown packet type received after authentication: %d", type);
376 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
380 /* Enable compression now that we have replied if appropriate. */
381 if (enable_compression_after_reply) {
382 enable_compression_after_reply = 0;
383 packet_start_compression(compression_level);
389 * This is called to fork and execute a command when we have no tty. This
390 * will call do_child from the child, and server_loop from the parent after
391 * setting up file descriptors and such.
394 do_exec_no_pty(Session *s, const char *command)
399 int pin[2], pout[2], perr[2];
400 /* Allocate pipes for communicating with the program. */
401 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
402 packet_disconnect("Could not create pipes: %.100s",
404 #else /* USE_PIPES */
405 int inout[2], err[2];
406 /* Uses socket pairs to communicate with the program. */
407 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
408 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
409 packet_disconnect("Could not create socket pairs: %.100s",
411 #endif /* USE_PIPES */
413 fatal("do_exec_no_pty: no session");
415 session_proctitle(s);
418 if (options.use_pam && !use_privsep)
422 /* Fork the child. */
423 if ((pid = fork()) == 0) {
426 /* Child. Reinitialize the log since the pid has changed. */
427 log_init(__progname, options.log_level, options.log_facility, log_stderr);
430 * Create a new session and process group since the 4.4BSD
431 * setlogin() affects the entire process group.
434 error("setsid failed: %.100s", strerror(errno));
438 * Redirect stdin. We close the parent side of the socket
439 * pair, and make the child side the standard input.
442 if (dup2(pin[0], 0) < 0)
443 perror("dup2 stdin");
446 /* Redirect stdout. */
448 if (dup2(pout[1], 1) < 0)
449 perror("dup2 stdout");
452 /* Redirect stderr. */
454 if (dup2(perr[1], 2) < 0)
455 perror("dup2 stderr");
457 #else /* USE_PIPES */
459 * Redirect stdin, stdout, and stderr. Stdin and stdout will
460 * use the same socket, as some programs (particularly rdist)
461 * seem to depend on it.
465 if (dup2(inout[0], 0) < 0) /* stdin */
466 perror("dup2 stdin");
467 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
468 perror("dup2 stdout");
469 if (dup2(err[0], 2) < 0) /* stderr */
470 perror("dup2 stderr");
471 #endif /* USE_PIPES */
474 cray_init_job(s->pw); /* set up cray jid and tmpdir */
477 /* Do processing for the child (exec command etc). */
478 do_child(s, command);
482 signal(WJSIGNAL, cray_job_termination_handler);
486 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
489 packet_disconnect("fork failed: %.100s", strerror(errno));
491 /* Set interactive/non-interactive mode. */
492 packet_set_interactive(s->display != NULL);
494 /* We are the parent. Close the child sides of the pipes. */
500 if (s->is_subsystem) {
504 session_set_fds(s, pin[1], pout[0], perr[0]);
506 /* Enter the interactive session. */
507 server_loop(pid, pin[1], pout[0], perr[0]);
508 /* server_loop has closed pin[1], pout[0], and perr[0]. */
510 #else /* USE_PIPES */
511 /* We are the parent. Close the child sides of the socket pairs. */
516 * Clear loginmsg, since it's the child's responsibility to display
517 * it to the user, otherwise multiple sessions may accumulate
518 * multiple copies of the login messages.
520 buffer_clear(&loginmsg);
523 * Enter the interactive session. Note: server_loop must be able to
524 * handle the case that fdin and fdout are the same.
527 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
529 server_loop(pid, inout[1], inout[1], err[1]);
530 /* server_loop has closed inout[1] and err[1]. */
532 #endif /* USE_PIPES */
536 * This is called to fork and execute a command when we have a tty. This
537 * will call do_child from the child, and server_loop from the parent after
538 * setting up file descriptors, controlling tty, updating wtmp, utmp,
539 * lastlog, and other such operations.
542 do_exec_pty(Session *s, const char *command)
544 int fdout, ptyfd, ttyfd, ptymaster;
548 fatal("do_exec_pty: no session");
553 if (options.use_pam) {
554 do_pam_set_tty(s->tty);
560 /* Fork the child. */
561 if ((pid = fork()) == 0) {
564 /* Child. Reinitialize the log because the pid has changed. */
565 log_init(__progname, options.log_level, options.log_facility, log_stderr);
566 /* Close the master side of the pseudo tty. */
569 /* Make the pseudo tty our controlling tty. */
570 pty_make_controlling_tty(&ttyfd, s->tty);
572 /* Redirect stdin/stdout/stderr from the pseudo tty. */
573 if (dup2(ttyfd, 0) < 0)
574 error("dup2 stdin: %s", strerror(errno));
575 if (dup2(ttyfd, 1) < 0)
576 error("dup2 stdout: %s", strerror(errno));
577 if (dup2(ttyfd, 2) < 0)
578 error("dup2 stderr: %s", strerror(errno));
580 /* Close the extra descriptor for the pseudo tty. */
583 /* record login, etc. similar to login(1) */
585 if (!(options.use_login && command == NULL)) {
587 cray_init_job(s->pw); /* set up cray jid and tmpdir */
589 do_login(s, command);
591 # ifdef LOGIN_NEEDS_UTMPX
597 /* Do common processing for the child, such as execing the command. */
598 do_child(s, command);
602 signal(WJSIGNAL, cray_job_termination_handler);
606 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
609 packet_disconnect("fork failed: %.100s", strerror(errno));
612 /* Parent. Close the slave side of the pseudo tty. */
616 * Create another descriptor of the pty master side for use as the
617 * standard input. We could use the original descriptor, but this
618 * simplifies code in server_loop. The descriptor is bidirectional.
622 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
624 /* we keep a reference to the pty master */
625 ptymaster = dup(ptyfd);
627 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
628 s->ptymaster = ptymaster;
630 /* Enter interactive session. */
631 packet_set_interactive(1);
633 session_set_fds(s, ptyfd, fdout, -1);
635 server_loop(pid, ptyfd, fdout, -1);
636 /* server_loop _has_ closed ptyfd and fdout. */
640 #ifdef LOGIN_NEEDS_UTMPX
642 do_pre_login(Session *s)
645 struct sockaddr_storage from;
646 pid_t pid = getpid();
649 * Get IP address of client. If the connection is not a socket, let
650 * the address be 0.0.0.0.
652 memset(&from, 0, sizeof(from));
653 fromlen = sizeof(from);
654 if (packet_connection_is_on_socket()) {
655 if (getpeername(packet_get_connection_in(),
656 (struct sockaddr *)&from, &fromlen) < 0) {
657 debug("getpeername: %.100s", strerror(errno));
662 record_utmp_only(pid, s->tty, s->pw->pw_name,
663 get_remote_name_or_ip(utmp_len, options.use_dns),
664 (struct sockaddr *)&from, fromlen);
669 * This is called to fork and execute a command. If another command is
670 * to be forced, execute that instead.
673 do_exec(Session *s, const char *command)
675 if (forced_command) {
676 original_command = command;
677 command = forced_command;
678 debug("Forced command '%.900s'", command);
681 #ifdef SSH_AUDIT_EVENTS
683 PRIVSEP(audit_run_command(command));
684 else if (s->ttyfd == -1) {
685 char *shell = s->pw->pw_shell;
687 if (shell[0] == '\0') /* empty shell means /bin/sh */
689 PRIVSEP(audit_run_command(shell));
694 do_exec_pty(s, command);
696 do_exec_no_pty(s, command);
698 original_command = NULL;
701 * Clear loginmsg: it's the child's responsibility to display
702 * it to the user, otherwise multiple sessions may accumulate
703 * multiple copies of the login messages.
705 buffer_clear(&loginmsg);
708 /* administrative, login(1)-like work */
710 do_login(Session *s, const char *command)
713 struct sockaddr_storage from;
714 struct passwd * pw = s->pw;
715 pid_t pid = getpid();
718 * Get IP address of client. If the connection is not a socket, let
719 * the address be 0.0.0.0.
721 memset(&from, 0, sizeof(from));
722 fromlen = sizeof(from);
723 if (packet_connection_is_on_socket()) {
724 if (getpeername(packet_get_connection_in(),
725 (struct sockaddr *) & from, &fromlen) < 0) {
726 debug("getpeername: %.100s", strerror(errno));
731 /* Record that there was a login on that tty from the remote host. */
733 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
734 get_remote_name_or_ip(utmp_len,
736 (struct sockaddr *)&from, fromlen);
740 * If password change is needed, do it now.
741 * This needs to occur before the ~/.hushlogin check.
743 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
746 s->authctxt->force_pwchange = 0;
747 /* XXX - signal [net] parent to enable forwardings */
751 if (check_quietlogin(s, command))
760 * Display the message of the day.
768 if (options.print_motd) {
769 #ifdef HAVE_LOGIN_CAP
770 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
773 f = fopen("/etc/motd", "r");
776 while (fgets(buf, sizeof(buf), f))
785 * Check for quiet login, either .hushlogin or command given.
788 check_quietlogin(Session *s, const char *command)
791 struct passwd *pw = s->pw;
794 /* Return 1 if .hushlogin exists or a command given. */
797 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
798 #ifdef HAVE_LOGIN_CAP
799 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
802 if (stat(buf, &st) >= 0)
809 * Sets the value of the given variable in the environment. If the variable
810 * already exists, its value is overriden.
813 child_set_env(char ***envp, u_int *envsizep, const char *name,
821 * If we're passed an uninitialized list, allocate a single null
822 * entry before continuing.
824 if (*envp == NULL && *envsizep == 0) {
825 *envp = xmalloc(sizeof(char *));
831 * Find the slot where the value should be stored. If the variable
832 * already exists, we reuse the slot; otherwise we append a new slot
833 * at the end of the array, expanding if necessary.
836 namelen = strlen(name);
837 for (i = 0; env[i]; i++)
838 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
841 /* Reuse the slot. */
844 /* New variable. Expand if necessary. */
846 if (i >= envsize - 1) {
848 fatal("child_set_env: too many env vars");
850 env = (*envp) = xrealloc(env, envsize, sizeof(char *));
853 /* Need to set the NULL pointer at end of array beyond the new slot. */
857 /* Allocate space and format the variable in the appropriate slot. */
858 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
859 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
863 * Reads environment variables from the given file and adds/overrides them
864 * into the environment. If the file does not exist, this does nothing.
865 * Otherwise, it must consist of empty lines, comments (line starts with '#')
866 * and assignments of the form name=value. No other forms are allowed.
869 read_environment_file(char ***env, u_int *envsize,
870 const char *filename)
877 f = fopen(filename, "r");
881 while (fgets(buf, sizeof(buf), f)) {
883 fatal("Too many lines in environment file %s", filename);
884 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
886 if (!*cp || *cp == '#' || *cp == '\n')
888 if (strchr(cp, '\n'))
889 *strchr(cp, '\n') = '\0';
890 value = strchr(cp, '=');
892 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
897 * Replace the equals sign by nul, and advance value to
902 child_set_env(env, envsize, cp, value);
907 #ifdef HAVE_ETC_DEFAULT_LOGIN
909 * Return named variable from specified environment, or NULL if not present.
912 child_get_env(char **env, const char *name)
918 for (i=0; env[i] != NULL; i++)
919 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
920 return(env[i] + len + 1);
925 * Read /etc/default/login.
926 * We pick up the PATH (or SUPATH for root) and UMASK.
929 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
931 char **tmpenv = NULL, *var;
932 u_int i, tmpenvsize = 0;
936 * We don't want to copy the whole file to the child's environment,
937 * so we use a temporary environment and copy the variables we're
940 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
946 var = child_get_env(tmpenv, "SUPATH");
948 var = child_get_env(tmpenv, "PATH");
950 child_set_env(env, envsize, "PATH", var);
952 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
953 if (sscanf(var, "%5lo", &mask) == 1)
956 for (i = 0; tmpenv[i] != NULL; i++)
960 #endif /* HAVE_ETC_DEFAULT_LOGIN */
963 copy_environment(char **source, char ***env, u_int *envsize)
965 char *var_name, *var_val;
971 for(i = 0; source[i] != NULL; i++) {
972 var_name = xstrdup(source[i]);
973 if ((var_val = strstr(var_name, "=")) == NULL) {
979 debug3("Copy environment: %s=%s", var_name, var_val);
980 child_set_env(env, envsize, var_name, var_val);
987 do_setup_env(Session *s, const char *shell)
991 char **env, *laddr, *path = NULL;
992 struct passwd *pw = s->pw;
994 /* Initialize the environment. */
996 env = xcalloc(envsize, sizeof(char *));
1001 * The Windows environment contains some setting which are
1002 * important for a running system. They must not be dropped.
1007 p = fetch_windows_environment();
1008 copy_environment(p, &env, &envsize);
1009 free_windows_environment(p);
1014 /* Allow any GSSAPI methods that we've used to alter
1015 * the childs environment as they see fit
1017 ssh_gssapi_do_child(&env, &envsize);
1020 if (!options.use_login) {
1021 /* Set basic environment. */
1022 for (i = 0; i < s->num_env; i++)
1023 child_set_env(&env, &envsize, s->env[i].name,
1026 child_set_env(&env, &envsize, "USER", pw->pw_name);
1027 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1029 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1031 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1032 #ifdef HAVE_LOGIN_CAP
1033 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1034 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1036 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1037 #else /* HAVE_LOGIN_CAP */
1038 # ifndef HAVE_CYGWIN
1040 * There's no standard path on Windows. The path contains
1041 * important components pointing to the system directories,
1042 * needed for loading shared libraries. So the path better
1043 * remains intact here.
1045 # ifdef HAVE_ETC_DEFAULT_LOGIN
1046 read_etc_default_login(&env, &envsize, pw->pw_uid);
1047 path = child_get_env(env, "PATH");
1048 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1049 if (path == NULL || *path == '\0') {
1050 child_set_env(&env, &envsize, "PATH",
1051 s->pw->pw_uid == 0 ?
1052 SUPERUSER_PATH : _PATH_STDPATH);
1054 # endif /* HAVE_CYGWIN */
1055 #endif /* HAVE_LOGIN_CAP */
1057 snprintf(buf, sizeof buf, "%.200s/%.50s",
1058 _PATH_MAILDIR, pw->pw_name);
1059 child_set_env(&env, &envsize, "MAIL", buf);
1061 /* Normal systems set SHELL by default. */
1062 child_set_env(&env, &envsize, "SHELL", shell);
1065 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1067 /* Set custom environment options from RSA authentication. */
1068 if (!options.use_login) {
1069 while (custom_environment) {
1070 struct envstring *ce = custom_environment;
1073 for (i = 0; str[i] != '=' && str[i]; i++)
1075 if (str[i] == '=') {
1077 child_set_env(&env, &envsize, str, str + i + 1);
1079 custom_environment = ce->next;
1085 /* SSH_CLIENT deprecated */
1086 snprintf(buf, sizeof buf, "%.50s %d %d",
1087 get_remote_ipaddr(), get_remote_port(), get_local_port());
1088 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1090 laddr = get_local_ipaddr(packet_get_connection_in());
1091 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1092 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1094 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1097 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1099 child_set_env(&env, &envsize, "TERM", s->term);
1101 child_set_env(&env, &envsize, "DISPLAY", s->display);
1102 if (original_command)
1103 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1107 if (cray_tmpdir[0] != '\0')
1108 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1109 #endif /* _UNICOS */
1112 * Since we clear KRB5CCNAME at startup, if it's set now then it
1113 * must have been set by a native authentication method (eg AIX or
1114 * SIA), so copy it to the child.
1119 if ((cp = getenv("KRB5CCNAME")) != NULL)
1120 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1127 if ((cp = getenv("AUTHSTATE")) != NULL)
1128 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1129 read_environment_file(&env, &envsize, "/etc/environment");
1133 if (s->authctxt->krb5_ccname)
1134 child_set_env(&env, &envsize, "KRB5CCNAME",
1135 s->authctxt->krb5_ccname);
1139 * Pull in any environment variables that may have
1142 if (options.use_pam) {
1145 p = fetch_pam_child_environment();
1146 copy_environment(p, &env, &envsize);
1147 free_pam_environment(p);
1149 p = fetch_pam_environment();
1150 copy_environment(p, &env, &envsize);
1151 free_pam_environment(p);
1153 #endif /* USE_PAM */
1155 if (auth_sock_name != NULL)
1156 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1159 /* read $HOME/.ssh/environment. */
1160 if (options.permit_user_env && !options.use_login) {
1161 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1162 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1163 read_environment_file(&env, &envsize, buf);
1166 /* dump the environment */
1167 fprintf(stderr, "Environment:\n");
1168 for (i = 0; env[i]; i++)
1169 fprintf(stderr, " %.200s\n", env[i]);
1175 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1176 * first in this order).
1179 do_rc_files(Session *s, const char *shell)
1187 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1189 /* ignore _PATH_SSH_USER_RC for subsystems */
1190 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1191 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1192 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1194 fprintf(stderr, "Running %s\n", cmd);
1195 f = popen(cmd, "w");
1198 fprintf(f, "%s %s\n", s->auth_proto,
1202 fprintf(stderr, "Could not run %s\n",
1204 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1206 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1207 _PATH_SSH_SYSTEM_RC);
1208 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1211 fprintf(f, "%s %s\n", s->auth_proto,
1215 fprintf(stderr, "Could not run %s\n",
1216 _PATH_SSH_SYSTEM_RC);
1217 } else if (do_xauth && options.xauth_location != NULL) {
1218 /* Add authority data to .Xauthority if appropriate. */
1221 "Running %.500s remove %.100s\n",
1222 options.xauth_location, s->auth_display);
1224 "%.500s add %.100s %.100s %.100s\n",
1225 options.xauth_location, s->auth_display,
1226 s->auth_proto, s->auth_data);
1228 snprintf(cmd, sizeof cmd, "%s -q -",
1229 options.xauth_location);
1230 f = popen(cmd, "w");
1232 fprintf(f, "remove %s\n",
1234 fprintf(f, "add %s %s %s\n",
1235 s->auth_display, s->auth_proto,
1239 fprintf(stderr, "Could not run %s\n",
1246 do_nologin(struct passwd *pw)
1251 #ifdef HAVE_LOGIN_CAP
1252 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1253 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1254 _PATH_NOLOGIN), "r");
1257 f = fopen(_PATH_NOLOGIN, "r");
1260 /* /etc/nologin exists. Print its contents and exit. */
1261 logit("User %.100s not allowed because %s exists",
1262 pw->pw_name, _PATH_NOLOGIN);
1263 while (fgets(buf, sizeof(buf), f))
1271 /* Set login name, uid, gid, and groups. */
1273 do_setusercontext(struct passwd *pw)
1276 if (getuid() == 0 || geteuid() == 0)
1277 #endif /* HAVE_CYGWIN */
1280 #ifdef HAVE_SETPCRED
1281 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1282 fatal("Failed to set process credentials");
1283 #endif /* HAVE_SETPCRED */
1284 #ifdef HAVE_LOGIN_CAP
1289 if (options.gss_authentication) {
1290 temporarily_use_uid(pw);
1291 ssh_gssapi_storecreds();
1296 if (options.use_pam) {
1300 # endif /* USE_PAM */
1301 if (setusercontext(lc, pw, pw->pw_uid,
1302 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1303 perror("unable to set user context");
1307 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1308 /* Sets login uid for accounting */
1309 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1310 error("setluid: %s", strerror(errno));
1311 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1313 if (setlogin(pw->pw_name) < 0)
1314 error("setlogin failed: %s", strerror(errno));
1315 if (setgid(pw->pw_gid) < 0) {
1319 /* Initialize the group list. */
1320 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1321 perror("initgroups");
1326 if (options.gss_authentication) {
1327 temporarily_use_uid(pw);
1328 ssh_gssapi_storecreds();
1334 * PAM credentials may take the form of supplementary groups.
1335 * These will have been wiped by the above initgroups() call.
1336 * Reestablish them here.
1338 if (options.use_pam) {
1342 # endif /* USE_PAM */
1343 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1344 irix_setusercontext(pw);
1345 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1349 #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
1350 if (set_id(pw->pw_name) != 0) {
1353 #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
1354 /* Permanently switch to the desired uid. */
1355 permanently_set_uid(pw);
1362 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1363 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1366 ssh_selinux_setup_exec_context(pw->pw_name);
1371 do_pwchange(Session *s)
1374 fprintf(stderr, "WARNING: Your password has expired.\n");
1375 if (s->ttyfd != -1) {
1377 "You must change your password now and login again!\n");
1378 #ifdef PASSWD_NEEDS_USERNAME
1379 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1382 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1387 "Password change required but no TTY available.\n");
1393 launch_login(struct passwd *pw, const char *hostname)
1395 /* Launch login(1). */
1397 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1398 #ifdef xxxLOGIN_NEEDS_TERM
1399 (s->term ? s->term : "unknown"),
1400 #endif /* LOGIN_NEEDS_TERM */
1401 #ifdef LOGIN_NO_ENDOPT
1402 "-p", "-f", pw->pw_name, (char *)NULL);
1404 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1407 /* Login couldn't be executed, die. */
1414 child_close_fds(void)
1418 if (packet_get_connection_in() == packet_get_connection_out())
1419 close(packet_get_connection_in());
1421 close(packet_get_connection_in());
1422 close(packet_get_connection_out());
1425 * Close all descriptors related to channels. They will still remain
1426 * open in the parent.
1428 /* XXX better use close-on-exec? -markus */
1429 channel_close_all();
1432 * Close any extra file descriptors. Note that there may still be
1433 * descriptors left by system functions. They will be closed later.
1438 * Close any extra open file descriptors so that we don't have them
1439 * hanging around in clients. Note that we want to do this after
1440 * initgroups, because at least on Solaris 2.3 it leaves file
1443 for (i = 3; i < 64; i++)
1448 * Performs common processing for the child, such as setting up the
1449 * environment, closing extra file descriptors, setting the user and group
1450 * ids, and executing the command or shell.
1453 do_child(Session *s, const char *command)
1455 extern char **environ;
1458 const char *shell, *shell0, *hostname = NULL;
1459 struct passwd *pw = s->pw;
1461 /* remove hostkey from the child's memory */
1462 destroy_sensitive_data();
1464 /* Force a password change */
1465 if (s->authctxt->force_pwchange) {
1466 do_setusercontext(pw);
1472 /* login(1) is only called if we execute the login shell */
1473 if (options.use_login && command != NULL)
1474 options.use_login = 0;
1477 cray_setup(pw->pw_uid, pw->pw_name, command);
1478 #endif /* _UNICOS */
1481 * Login(1) does this as well, and it needs uid 0 for the "-h"
1482 * switch, so we let login(1) to this for us.
1484 if (!options.use_login) {
1486 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1487 if (!check_quietlogin(s, command))
1489 #else /* HAVE_OSF_SIA */
1490 /* When PAM is enabled we rely on it to do the nologin check */
1491 if (!options.use_pam)
1493 do_setusercontext(pw);
1495 * PAM session modules in do_setusercontext may have
1496 * generated messages, so if this in an interactive
1497 * login then display them too.
1499 if (!check_quietlogin(s, command))
1501 #endif /* HAVE_OSF_SIA */
1505 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1506 debug3("PAM session not opened, exiting");
1513 * Get the shell from the password data. An empty shell field is
1514 * legal, and means /bin/sh.
1516 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1519 * Make sure $SHELL points to the shell from the password file,
1520 * even if shell is overridden from login.conf
1522 env = do_setup_env(s, shell);
1524 #ifdef HAVE_LOGIN_CAP
1525 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1528 /* we have to stash the hostname before we close our socket. */
1529 if (options.use_login)
1530 hostname = get_remote_name_or_ip(utmp_len,
1533 * Close the connection descriptors; note that this is the child, and
1534 * the server will still have the socket open, and it is important
1535 * that we do not shutdown it. Note that the descriptors cannot be
1536 * closed before building the environment, as we call
1537 * get_remote_ipaddr there.
1542 * Must take new environment into use so that .ssh/rc,
1543 * /etc/ssh/sshrc and xauth are run in the proper environment.
1547 #if defined(KRB5) && defined(USE_AFS)
1549 * At this point, we check to see if AFS is active and if we have
1550 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1551 * if we can (and need to) extend the ticket into an AFS token. If
1552 * we don't do this, we run into potential problems if the user's
1553 * home directory is in AFS and it's not world-readable.
1556 if (options.kerberos_get_afs_token && k_hasafs() &&
1557 (s->authctxt->krb5_ctx != NULL)) {
1560 debug("Getting AFS token");
1564 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1565 krb5_afslog(s->authctxt->krb5_ctx,
1566 s->authctxt->krb5_fwd_ccache, cell, NULL);
1568 krb5_afslog_home(s->authctxt->krb5_ctx,
1569 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1573 /* Change current directory to the user's home directory. */
1574 if (chdir(pw->pw_dir) < 0) {
1575 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1576 pw->pw_dir, strerror(errno));
1577 #ifdef HAVE_LOGIN_CAP
1578 if (login_getcapbool(lc, "requirehome", 0))
1583 if (!options.use_login)
1584 do_rc_files(s, shell);
1586 /* restore SIGPIPE for child */
1587 signal(SIGPIPE, SIG_DFL);
1589 if (options.use_login) {
1590 launch_login(pw, hostname);
1594 /* Get the last component of the shell name. */
1595 if ((shell0 = strrchr(shell, '/')) != NULL)
1601 * If we have no command, execute the shell. In this case, the shell
1602 * name to be passed in argv[0] is preceded by '-' to indicate that
1603 * this is a login shell.
1608 /* Start the shell. Set initial character to '-'. */
1611 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1612 >= sizeof(argv0) - 1) {
1618 /* Execute the shell. */
1621 execve(shell, argv, env);
1623 /* Executing the shell failed. */
1628 * Execute the command using the user's shell. This uses the -c
1629 * option to execute the command.
1631 argv[0] = (char *) shell0;
1633 argv[2] = (char *) command;
1635 execve(shell, argv, env);
1644 static int did_init = 0;
1646 debug("session_new: init");
1647 for (i = 0; i < MAX_SESSIONS; i++) {
1648 sessions[i].used = 0;
1652 for (i = 0; i < MAX_SESSIONS; i++) {
1653 Session *s = &sessions[i];
1655 memset(s, 0, sizeof(*s));
1661 s->x11_chanids = NULL;
1662 debug("session_new: session %d", i);
1673 for (i = 0; i < MAX_SESSIONS; i++) {
1674 Session *s = &sessions[i];
1675 debug("dump: used %d session %d %p channel %d pid %ld",
1685 session_open(Authctxt *authctxt, int chanid)
1687 Session *s = session_new();
1688 debug("session_open: channel %d", chanid);
1690 error("no more sessions");
1693 s->authctxt = authctxt;
1694 s->pw = authctxt->pw;
1695 if (s->pw == NULL || !authctxt->valid)
1696 fatal("no user for session %d", s->self);
1697 debug("session_open: session %d: link with channel %d", s->self, chanid);
1703 session_by_tty(char *tty)
1706 for (i = 0; i < MAX_SESSIONS; i++) {
1707 Session *s = &sessions[i];
1708 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1709 debug("session_by_tty: session %d tty %s", i, tty);
1713 debug("session_by_tty: unknown tty %.100s", tty);
1719 session_by_channel(int id)
1722 for (i = 0; i < MAX_SESSIONS; i++) {
1723 Session *s = &sessions[i];
1724 if (s->used && s->chanid == id) {
1725 debug("session_by_channel: session %d channel %d", i, id);
1729 debug("session_by_channel: unknown channel %d", id);
1735 session_by_x11_channel(int id)
1739 for (i = 0; i < MAX_SESSIONS; i++) {
1740 Session *s = &sessions[i];
1742 if (s->x11_chanids == NULL || !s->used)
1744 for (j = 0; s->x11_chanids[j] != -1; j++) {
1745 if (s->x11_chanids[j] == id) {
1746 debug("session_by_x11_channel: session %d "
1747 "channel %d", s->self, id);
1752 debug("session_by_x11_channel: unknown channel %d", id);
1758 session_by_pid(pid_t pid)
1761 debug("session_by_pid: pid %ld", (long)pid);
1762 for (i = 0; i < MAX_SESSIONS; i++) {
1763 Session *s = &sessions[i];
1764 if (s->used && s->pid == pid)
1767 error("session_by_pid: unknown pid %ld", (long)pid);
1773 session_window_change_req(Session *s)
1775 s->col = packet_get_int();
1776 s->row = packet_get_int();
1777 s->xpixel = packet_get_int();
1778 s->ypixel = packet_get_int();
1780 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1785 session_pty_req(Session *s)
1791 debug("Allocating a pty not permitted for this authentication.");
1794 if (s->ttyfd != -1) {
1795 packet_disconnect("Protocol error: you already have a pty.");
1799 s->term = packet_get_string(&len);
1802 s->col = packet_get_int();
1803 s->row = packet_get_int();
1805 s->row = packet_get_int();
1806 s->col = packet_get_int();
1808 s->xpixel = packet_get_int();
1809 s->ypixel = packet_get_int();
1811 if (strcmp(s->term, "") == 0) {
1816 /* Allocate a pty and open it. */
1817 debug("Allocating pty.");
1818 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1824 error("session_pty_req: session %d alloc failed", s->self);
1827 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1829 /* for SSH1 the tty modes length is not given */
1831 n_bytes = packet_remaining();
1832 tty_parse_modes(s->ttyfd, &n_bytes);
1835 pty_setowner(s->pw, s->tty);
1837 /* Set window size from the packet. */
1838 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1841 session_proctitle(s);
1846 session_subsystem_req(Session *s)
1851 char *prog, *cmd, *subsys = packet_get_string(&len);
1855 logit("subsystem request for %.100s", subsys);
1857 for (i = 0; i < options.num_subsystems; i++) {
1858 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1859 prog = options.subsystem_command[i];
1860 cmd = options.subsystem_args[i];
1861 if (stat(prog, &st) < 0) {
1862 error("subsystem: cannot stat %s: %s", prog,
1866 debug("subsystem: exec() %s", cmd);
1867 s->is_subsystem = 1;
1875 logit("subsystem request for %.100s failed, subsystem not found",
1883 session_x11_req(Session *s)
1887 if (s->auth_proto != NULL || s->auth_data != NULL) {
1888 error("session_x11_req: session %d: "
1889 "x11 forwarding already active", s->self);
1892 s->single_connection = packet_get_char();
1893 s->auth_proto = packet_get_string(NULL);
1894 s->auth_data = packet_get_string(NULL);
1895 s->screen = packet_get_int();
1898 success = session_setup_x11fwd(s);
1900 xfree(s->auth_proto);
1901 xfree(s->auth_data);
1902 s->auth_proto = NULL;
1903 s->auth_data = NULL;
1909 session_shell_req(Session *s)
1917 session_exec_req(Session *s)
1920 char *command = packet_get_string(&len);
1922 do_exec(s, command);
1928 session_break_req(Session *s)
1931 packet_get_int(); /* ignored */
1934 if (s->ttyfd == -1 ||
1935 tcsendbreak(s->ttyfd, 0) < 0)
1941 session_env_req(Session *s)
1944 u_int name_len, val_len, i;
1946 name = packet_get_string(&name_len);
1947 val = packet_get_string(&val_len);
1950 /* Don't set too many environment variables */
1951 if (s->num_env > 128) {
1952 debug2("Ignoring env request %s: too many env vars", name);
1956 for (i = 0; i < options.num_accept_env; i++) {
1957 if (match_pattern(name, options.accept_env[i])) {
1958 debug2("Setting env %d: %s=%s", s->num_env, name, val);
1959 s->env = xrealloc(s->env, s->num_env + 1,
1961 s->env[s->num_env].name = name;
1962 s->env[s->num_env].val = val;
1967 debug2("Ignoring env request %s: disallowed name", name);
1976 session_auth_agent_req(Session *s)
1978 static int called = 0;
1980 if (no_agent_forwarding_flag) {
1981 debug("session_auth_agent_req: no_agent_forwarding_flag");
1988 return auth_input_request_forwarding(s->pw);
1993 session_input_channel_req(Channel *c, const char *rtype)
1998 if ((s = session_by_channel(c->self)) == NULL) {
1999 logit("session_input_channel_req: no session %d req %.100s",
2003 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2006 * a session is in LARVAL state until a shell, a command
2007 * or a subsystem is executed
2009 if (c->type == SSH_CHANNEL_LARVAL) {
2010 if (strcmp(rtype, "shell") == 0) {
2011 success = session_shell_req(s);
2012 } else if (strcmp(rtype, "exec") == 0) {
2013 success = session_exec_req(s);
2014 } else if (strcmp(rtype, "pty-req") == 0) {
2015 success = session_pty_req(s);
2016 } else if (strcmp(rtype, "x11-req") == 0) {
2017 success = session_x11_req(s);
2018 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2019 success = session_auth_agent_req(s);
2020 } else if (strcmp(rtype, "subsystem") == 0) {
2021 success = session_subsystem_req(s);
2022 } else if (strcmp(rtype, "env") == 0) {
2023 success = session_env_req(s);
2026 if (strcmp(rtype, "window-change") == 0) {
2027 success = session_window_change_req(s);
2028 } else if (strcmp(rtype, "break") == 0) {
2029 success = session_break_req(s);
2036 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2039 fatal("session_set_fds: called for proto != 2.0");
2041 * now that have a child and a pipe to the child,
2042 * we can activate our channel and register the fd's
2044 if (s->chanid == -1)
2045 fatal("no channel for session %d", s->self);
2046 channel_set_fds(s->chanid,
2048 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2050 CHAN_SES_WINDOW_DEFAULT);
2054 * Function to perform pty cleanup. Also called if we get aborted abnormally
2055 * (e.g., due to a dropped connection).
2058 session_pty_cleanup2(Session *s)
2061 error("session_pty_cleanup: no session");
2067 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2069 /* Record that the user has logged out. */
2071 record_logout(s->pid, s->tty, s->pw->pw_name);
2073 /* Release the pseudo-tty. */
2075 pty_release(s->tty);
2078 * Close the server side of the socket pairs. We must do this after
2079 * the pty cleanup, so that another process doesn't get this pty
2080 * while we're still cleaning up.
2082 if (close(s->ptymaster) < 0)
2083 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2085 /* unlink pty from session */
2090 session_pty_cleanup(Session *s)
2092 PRIVSEP(session_pty_cleanup2(s));
2098 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2113 return "SIG@openssh.com";
2117 session_close_x11(int id)
2121 if ((c = channel_by_id(id)) == NULL) {
2122 debug("session_close_x11: x11 channel %d missing", id);
2124 /* Detach X11 listener */
2125 debug("session_close_x11: detach x11 channel %d", id);
2126 channel_cancel_cleanup(id);
2127 if (c->ostate != CHAN_OUTPUT_CLOSED)
2133 session_close_single_x11(int id, void *arg)
2138 debug3("session_close_single_x11: channel %d", id);
2139 channel_cancel_cleanup(id);
2140 if ((s = session_by_x11_channel(id)) == NULL)
2141 fatal("session_close_single_x11: no x11 channel %d", id);
2142 for (i = 0; s->x11_chanids[i] != -1; i++) {
2143 debug("session_close_single_x11: session %d: "
2144 "closing channel %d", s->self, s->x11_chanids[i]);
2146 * The channel "id" is already closing, but make sure we
2147 * close all of its siblings.
2149 if (s->x11_chanids[i] != id)
2150 session_close_x11(s->x11_chanids[i]);
2152 xfree(s->x11_chanids);
2153 s->x11_chanids = NULL;
2158 if (s->auth_proto) {
2159 xfree(s->auth_proto);
2160 s->auth_proto = NULL;
2163 xfree(s->auth_data);
2164 s->auth_data = NULL;
2166 if (s->auth_display) {
2167 xfree(s->auth_display);
2168 s->auth_display = NULL;
2173 session_exit_message(Session *s, int status)
2177 if ((c = channel_lookup(s->chanid)) == NULL)
2178 fatal("session_exit_message: session %d: no channel %d",
2179 s->self, s->chanid);
2180 debug("session_exit_message: session %d channel %d pid %ld",
2181 s->self, s->chanid, (long)s->pid);
2183 if (WIFEXITED(status)) {
2184 channel_request_start(s->chanid, "exit-status", 0);
2185 packet_put_int(WEXITSTATUS(status));
2187 } else if (WIFSIGNALED(status)) {
2188 channel_request_start(s->chanid, "exit-signal", 0);
2189 packet_put_cstring(sig2name(WTERMSIG(status)));
2191 packet_put_char(WCOREDUMP(status));
2192 #else /* WCOREDUMP */
2194 #endif /* WCOREDUMP */
2195 packet_put_cstring("");
2196 packet_put_cstring("");
2199 /* Some weird exit cause. Just exit. */
2200 packet_disconnect("wait returned status %04x.", status);
2203 /* disconnect channel */
2204 debug("session_exit_message: release channel %d", s->chanid);
2207 * Adjust cleanup callback attachment to send close messages when
2208 * the channel gets EOF. The session will be then be closed
2209 * by session_close_by_channel when the childs close their fds.
2211 channel_register_cleanup(c->self, session_close_by_channel, 1);
2214 * emulate a write failure with 'chan_write_failed', nobody will be
2215 * interested in data we write.
2216 * Note that we must not call 'chan_read_failed', since there could
2217 * be some more data waiting in the pipe.
2219 if (c->ostate != CHAN_OUTPUT_CLOSED)
2220 chan_write_failed(c);
2224 session_close(Session *s)
2228 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2230 session_pty_cleanup(s);
2236 xfree(s->x11_chanids);
2237 if (s->auth_display)
2238 xfree(s->auth_display);
2240 xfree(s->auth_data);
2242 xfree(s->auth_proto);
2244 for (i = 0; i < s->num_env; i++) {
2245 xfree(s->env[i].name);
2246 xfree(s->env[i].val);
2250 session_proctitle(s);
2254 session_close_by_pid(pid_t pid, int status)
2256 Session *s = session_by_pid(pid);
2258 debug("session_close_by_pid: no session for pid %ld",
2262 if (s->chanid != -1)
2263 session_exit_message(s, status);
2265 session_pty_cleanup(s);
2270 * this is called when a channel dies before
2271 * the session 'child' itself dies
2274 session_close_by_channel(int id, void *arg)
2276 Session *s = session_by_channel(id);
2280 debug("session_close_by_channel: no session for id %d", id);
2283 debug("session_close_by_channel: channel %d child %ld",
2286 debug("session_close_by_channel: channel %d: has child", id);
2288 * delay detach of session, but release pty, since
2289 * the fd's to the child are already closed
2292 session_pty_cleanup(s);
2295 /* detach by removing callback */
2296 channel_cancel_cleanup(s->chanid);
2298 /* Close any X11 listeners associated with this session */
2299 if (s->x11_chanids != NULL) {
2300 for (i = 0; s->x11_chanids[i] != -1; i++) {
2301 session_close_x11(s->x11_chanids[i]);
2302 s->x11_chanids[i] = -1;
2311 session_destroy_all(void (*closefunc)(Session *))
2314 for (i = 0; i < MAX_SESSIONS; i++) {
2315 Session *s = &sessions[i];
2317 if (closefunc != NULL)
2326 session_tty_list(void)
2328 static char buf[1024];
2333 for (i = 0; i < MAX_SESSIONS; i++) {
2334 Session *s = &sessions[i];
2335 if (s->used && s->ttyfd != -1) {
2337 if (strncmp(s->tty, "/dev/", 5) != 0) {
2338 cp = strrchr(s->tty, '/');
2339 cp = (cp == NULL) ? s->tty : cp + 1;
2344 strlcat(buf, ",", sizeof buf);
2345 strlcat(buf, cp, sizeof buf);
2349 strlcpy(buf, "notty", sizeof buf);
2354 session_proctitle(Session *s)
2357 error("no user for session %d", s->self);
2359 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2363 session_setup_x11fwd(Session *s)
2366 char display[512], auth_display[512];
2367 char hostname[MAXHOSTNAMELEN];
2370 if (no_x11_forwarding_flag) {
2371 packet_send_debug("X11 forwarding disabled in user configuration file.");
2374 if (!options.x11_forwarding) {
2375 debug("X11 forwarding disabled in server configuration file.");
2378 if (!options.xauth_location ||
2379 (stat(options.xauth_location, &st) == -1)) {
2380 packet_send_debug("No xauth program; cannot forward with spoofing.");
2383 if (options.use_login) {
2384 packet_send_debug("X11 forwarding disabled; "
2385 "not compatible with UseLogin=yes.");
2388 if (s->display != NULL) {
2389 debug("X11 display already set.");
2392 if (x11_create_display_inet(options.x11_display_offset,
2393 options.x11_use_localhost, s->single_connection,
2394 &s->display_number, &s->x11_chanids) == -1) {
2395 debug("x11_create_display_inet failed.");
2398 for (i = 0; s->x11_chanids[i] != -1; i++) {
2399 channel_register_cleanup(s->x11_chanids[i],
2400 session_close_single_x11, 0);
2403 /* Set up a suitable value for the DISPLAY variable. */
2404 if (gethostname(hostname, sizeof(hostname)) < 0)
2405 fatal("gethostname: %.100s", strerror(errno));
2407 * auth_display must be used as the displayname when the
2408 * authorization entry is added with xauth(1). This will be
2409 * different than the DISPLAY string for localhost displays.
2411 if (options.x11_use_localhost) {
2412 snprintf(display, sizeof display, "localhost:%u.%u",
2413 s->display_number, s->screen);
2414 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2415 s->display_number, s->screen);
2416 s->display = xstrdup(display);
2417 s->auth_display = xstrdup(auth_display);
2419 #ifdef IPADDR_IN_DISPLAY
2421 struct in_addr my_addr;
2423 he = gethostbyname(hostname);
2425 error("Can't get IP address for X11 DISPLAY.");
2426 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2429 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2430 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2431 s->display_number, s->screen);
2433 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2434 s->display_number, s->screen);
2436 s->display = xstrdup(display);
2437 s->auth_display = xstrdup(display);
2444 do_authenticated2(Authctxt *authctxt)
2446 server_loop2(authctxt);
2450 do_cleanup(Authctxt *authctxt)
2452 static int called = 0;
2454 debug("do_cleanup");
2456 /* no cleanup if we're in the child for login shell */
2460 /* avoid double cleanup */
2465 if (authctxt == NULL)
2468 if (options.kerberos_ticket_cleanup &&
2470 krb5_cleanup_proc(authctxt);
2474 if (compat20 && options.gss_cleanup_creds)
2475 ssh_gssapi_cleanup_creds();
2479 if (options.use_pam) {
2481 sshpam_thread_cleanup();
2485 /* remove agent socket */
2486 auth_sock_cleanup_proc(authctxt->pw);
2489 * Cleanup ptys/utmp only if privsep is disabled,
2490 * or if running in monitor.
2492 if (!use_privsep || mm_is_monitor())
2493 session_destroy_all(session_pty_cleanup2);