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.
39 #include <sys/types.h>
40 #include <sys/param.h>
41 #ifdef HAVE_SYS_STAT_H
42 # include <sys/stat.h>
44 #include <sys/socket.h>
48 #include <arpa/inet.h>
81 #include "auth-options.h"
82 #include "pathnames.h"
86 #include "serverloop.h"
90 #include "monitor_wrap.h"
92 #if defined(KRB5) && defined(USE_AFS)
98 Session *session_new(void);
99 void session_set_fds(Session *, int, int, int);
100 void session_pty_cleanup(Session *);
101 void session_proctitle(Session *);
102 int session_setup_x11fwd(Session *);
103 void do_exec_pty(Session *, const char *);
104 void do_exec_no_pty(Session *, const char *);
105 void do_exec(Session *, const char *);
106 void do_login(Session *, const char *);
107 #ifdef LOGIN_NEEDS_UTMPX
108 static void do_pre_login(Session *s);
110 void do_child(Session *, const char *);
112 int check_quietlogin(Session *, const char *);
114 static void do_authenticated1(Authctxt *);
115 static void do_authenticated2(Authctxt *);
117 static int session_pty_req(Session *);
120 extern ServerOptions options;
121 extern char *__progname;
122 extern int log_stderr;
123 extern int debug_flag;
124 extern u_int utmp_len;
125 extern int startup_pipe;
126 extern void destroy_sensitive_data(void);
127 extern Buffer loginmsg;
129 /* original command from peer. */
130 const char *original_command = NULL;
133 #define MAX_SESSIONS 10
134 Session sessions[MAX_SESSIONS];
136 #ifdef HAVE_LOGIN_CAP
140 static int is_child = 0;
142 /* Name and directory of socket for authentication agent forwarding. */
143 static char *auth_sock_name = NULL;
144 static char *auth_sock_dir = NULL;
146 /* removes the agent forwarding socket */
149 auth_sock_cleanup_proc(struct passwd *pw)
151 if (auth_sock_name != NULL) {
152 temporarily_use_uid(pw);
153 unlink(auth_sock_name);
154 rmdir(auth_sock_dir);
155 auth_sock_name = NULL;
161 auth_input_request_forwarding(struct passwd * pw)
165 struct sockaddr_un sunaddr;
167 if (auth_sock_name != NULL) {
168 error("authentication forwarding requested twice.");
172 /* Temporarily drop privileged uid for mkdir/bind. */
173 temporarily_use_uid(pw);
175 /* Allocate a buffer for the socket name, and format the name. */
176 auth_sock_name = xmalloc(MAXPATHLEN);
177 auth_sock_dir = xmalloc(MAXPATHLEN);
178 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
180 /* Create private directory for socket */
181 if (mkdtemp(auth_sock_dir) == NULL) {
182 packet_send_debug("Agent forwarding disabled: "
183 "mkdtemp() failed: %.100s", strerror(errno));
185 xfree(auth_sock_name);
186 xfree(auth_sock_dir);
187 auth_sock_name = NULL;
188 auth_sock_dir = NULL;
191 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
192 auth_sock_dir, (long) getpid());
194 /* Create the socket. */
195 sock = socket(AF_UNIX, SOCK_STREAM, 0);
197 packet_disconnect("socket: %.100s", strerror(errno));
199 /* Bind it to the name. */
200 memset(&sunaddr, 0, sizeof(sunaddr));
201 sunaddr.sun_family = AF_UNIX;
202 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
204 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0)
205 packet_disconnect("bind: %.100s", strerror(errno));
207 /* Restore the privileged uid. */
210 /* Start listening on the socket. */
211 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
212 packet_disconnect("listen: %.100s", strerror(errno));
214 /* Allocate a channel for the authentication agent socket. */
215 nc = channel_new("auth socket",
216 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
217 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
218 0, "auth socket", 1);
219 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
224 display_loginmsg(void)
226 if (buffer_len(&loginmsg) > 0) {
227 buffer_append(&loginmsg, "\0", 1);
228 printf("%s", (char *)buffer_ptr(&loginmsg));
229 buffer_clear(&loginmsg);
234 do_authenticated(Authctxt *authctxt)
236 setproctitle("%s", authctxt->pw->pw_name);
238 /* setup the channel layer */
239 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
240 channel_permit_all_opens();
243 do_authenticated2(authctxt);
245 do_authenticated1(authctxt);
247 do_cleanup(authctxt);
251 * Prepares for an interactive session. This is called after the user has
252 * been successfully authenticated. During this message exchange, pseudo
253 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
254 * are requested, etc.
257 do_authenticated1(Authctxt *authctxt)
261 int success, type, screen_flag;
262 int enable_compression_after_reply = 0;
263 u_int proto_len, data_len, dlen, compression_level = 0;
267 error("no more sessions");
270 s->authctxt = authctxt;
271 s->pw = authctxt->pw;
274 * We stay in this loop until the client requests to execute a shell
280 /* Get a packet from the client. */
281 type = packet_read();
283 /* Process the packet. */
285 case SSH_CMSG_REQUEST_COMPRESSION:
286 compression_level = packet_get_int();
288 if (compression_level < 1 || compression_level > 9) {
289 packet_send_debug("Received invalid compression level %d.",
293 if (options.compression == COMP_NONE) {
294 debug2("compression disabled");
297 /* Enable compression after we have responded with SUCCESS. */
298 enable_compression_after_reply = 1;
302 case SSH_CMSG_REQUEST_PTY:
303 success = session_pty_req(s);
306 case SSH_CMSG_X11_REQUEST_FORWARDING:
307 s->auth_proto = packet_get_string(&proto_len);
308 s->auth_data = packet_get_string(&data_len);
310 screen_flag = packet_get_protocol_flags() &
311 SSH_PROTOFLAG_SCREEN_NUMBER;
312 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
314 if (packet_remaining() == 4) {
316 debug2("Buggy client: "
317 "X11 screen flag missing");
318 s->screen = packet_get_int();
323 success = session_setup_x11fwd(s);
325 xfree(s->auth_proto);
327 s->auth_proto = NULL;
332 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
333 if (no_agent_forwarding_flag || compat13) {
334 debug("Authentication agent forwarding not permitted for this authentication.");
337 debug("Received authentication agent forwarding request.");
338 success = auth_input_request_forwarding(s->pw);
341 case SSH_CMSG_PORT_FORWARD_REQUEST:
342 if (no_port_forwarding_flag) {
343 debug("Port forwarding not permitted for this authentication.");
346 if (!options.allow_tcp_forwarding) {
347 debug("Port forwarding not permitted.");
350 debug("Received TCP/IP port forwarding request.");
351 if (channel_input_port_forward_request(s->pw->pw_uid == 0,
352 options.gateway_ports) < 0) {
353 debug("Port forwarding failed.");
359 case SSH_CMSG_MAX_PACKET_SIZE:
360 if (packet_set_maxsize(packet_get_int()) > 0)
364 case SSH_CMSG_EXEC_SHELL:
365 case SSH_CMSG_EXEC_CMD:
366 if (type == SSH_CMSG_EXEC_CMD) {
367 command = packet_get_string(&dlen);
368 debug("Exec command '%.500s'", command);
380 * Any unknown messages in this phase are ignored,
381 * and a failure message is returned.
383 logit("Unknown packet type received after authentication: %d", type);
385 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
389 /* Enable compression now that we have replied if appropriate. */
390 if (enable_compression_after_reply) {
391 enable_compression_after_reply = 0;
392 packet_start_compression(compression_level);
398 * This is called to fork and execute a command when we have no tty. This
399 * will call do_child from the child, and server_loop from the parent after
400 * setting up file descriptors and such.
403 do_exec_no_pty(Session *s, const char *command)
408 int pin[2], pout[2], perr[2];
409 /* Allocate pipes for communicating with the program. */
410 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
411 packet_disconnect("Could not create pipes: %.100s",
413 #else /* USE_PIPES */
414 int inout[2], err[2];
415 /* Uses socket pairs to communicate with the program. */
416 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
417 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
418 packet_disconnect("Could not create socket pairs: %.100s",
420 #endif /* USE_PIPES */
422 fatal("do_exec_no_pty: no session");
424 session_proctitle(s);
427 if (options.use_pam && !use_privsep)
431 /* Fork the child. */
432 if ((pid = fork()) == 0) {
435 /* Child. Reinitialize the log since the pid has changed. */
436 log_init(__progname, options.log_level, options.log_facility, log_stderr);
439 * Create a new session and process group since the 4.4BSD
440 * setlogin() affects the entire process group.
443 error("setsid failed: %.100s", strerror(errno));
447 * Redirect stdin. We close the parent side of the socket
448 * pair, and make the child side the standard input.
451 if (dup2(pin[0], 0) < 0)
452 perror("dup2 stdin");
455 /* Redirect stdout. */
457 if (dup2(pout[1], 1) < 0)
458 perror("dup2 stdout");
461 /* Redirect stderr. */
463 if (dup2(perr[1], 2) < 0)
464 perror("dup2 stderr");
466 #else /* USE_PIPES */
468 * Redirect stdin, stdout, and stderr. Stdin and stdout will
469 * use the same socket, as some programs (particularly rdist)
470 * seem to depend on it.
474 if (dup2(inout[0], 0) < 0) /* stdin */
475 perror("dup2 stdin");
476 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
477 perror("dup2 stdout");
478 if (dup2(err[0], 2) < 0) /* stderr */
479 perror("dup2 stderr");
480 #endif /* USE_PIPES */
483 cray_init_job(s->pw); /* set up cray jid and tmpdir */
486 /* Do processing for the child (exec command etc). */
487 do_child(s, command);
491 signal(WJSIGNAL, cray_job_termination_handler);
495 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
498 packet_disconnect("fork failed: %.100s", strerror(errno));
500 /* Set interactive/non-interactive mode. */
501 packet_set_interactive(s->display != NULL);
503 /* We are the parent. Close the child sides of the pipes. */
509 if (s->is_subsystem) {
513 session_set_fds(s, pin[1], pout[0], perr[0]);
515 /* Enter the interactive session. */
516 server_loop(pid, pin[1], pout[0], perr[0]);
517 /* server_loop has closed pin[1], pout[0], and perr[0]. */
519 #else /* USE_PIPES */
520 /* We are the parent. Close the child sides of the socket pairs. */
525 * Clear loginmsg, since it's the child's responsibility to display
526 * it to the user, otherwise multiple sessions may accumulate
527 * multiple copies of the login messages.
529 buffer_clear(&loginmsg);
532 * Enter the interactive session. Note: server_loop must be able to
533 * handle the case that fdin and fdout are the same.
536 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
538 server_loop(pid, inout[1], inout[1], err[1]);
539 /* server_loop has closed inout[1] and err[1]. */
541 #endif /* USE_PIPES */
545 * This is called to fork and execute a command when we have a tty. This
546 * will call do_child from the child, and server_loop from the parent after
547 * setting up file descriptors, controlling tty, updating wtmp, utmp,
548 * lastlog, and other such operations.
551 do_exec_pty(Session *s, const char *command)
553 int fdout, ptyfd, ttyfd, ptymaster;
557 fatal("do_exec_pty: no session");
562 if (options.use_pam) {
563 do_pam_set_tty(s->tty);
569 /* Fork the child. */
570 if ((pid = fork()) == 0) {
573 /* Child. Reinitialize the log because the pid has changed. */
574 log_init(__progname, options.log_level, options.log_facility, log_stderr);
575 /* Close the master side of the pseudo tty. */
578 /* Make the pseudo tty our controlling tty. */
579 pty_make_controlling_tty(&ttyfd, s->tty);
581 /* Redirect stdin/stdout/stderr from the pseudo tty. */
582 if (dup2(ttyfd, 0) < 0)
583 error("dup2 stdin: %s", strerror(errno));
584 if (dup2(ttyfd, 1) < 0)
585 error("dup2 stdout: %s", strerror(errno));
586 if (dup2(ttyfd, 2) < 0)
587 error("dup2 stderr: %s", strerror(errno));
589 /* Close the extra descriptor for the pseudo tty. */
592 /* record login, etc. similar to login(1) */
594 if (!(options.use_login && command == NULL)) {
596 cray_init_job(s->pw); /* set up cray jid and tmpdir */
598 do_login(s, command);
600 # ifdef LOGIN_NEEDS_UTMPX
606 /* Do common processing for the child, such as execing the command. */
607 do_child(s, command);
611 signal(WJSIGNAL, cray_job_termination_handler);
615 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
618 packet_disconnect("fork failed: %.100s", strerror(errno));
621 /* Parent. Close the slave side of the pseudo tty. */
625 * Create another descriptor of the pty master side for use as the
626 * standard input. We could use the original descriptor, but this
627 * simplifies code in server_loop. The descriptor is bidirectional.
631 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
633 /* we keep a reference to the pty master */
634 ptymaster = dup(ptyfd);
636 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
637 s->ptymaster = ptymaster;
639 /* Enter interactive session. */
640 packet_set_interactive(1);
642 session_set_fds(s, ptyfd, fdout, -1);
644 server_loop(pid, ptyfd, fdout, -1);
645 /* server_loop _has_ closed ptyfd and fdout. */
649 #ifdef LOGIN_NEEDS_UTMPX
651 do_pre_login(Session *s)
654 struct sockaddr_storage from;
655 pid_t pid = getpid();
658 * Get IP address of client. If the connection is not a socket, let
659 * the address be 0.0.0.0.
661 memset(&from, 0, sizeof(from));
662 fromlen = sizeof(from);
663 if (packet_connection_is_on_socket()) {
664 if (getpeername(packet_get_connection_in(),
665 (struct sockaddr *)&from, &fromlen) < 0) {
666 debug("getpeername: %.100s", strerror(errno));
671 record_utmp_only(pid, s->tty, s->pw->pw_name,
672 get_remote_name_or_ip(utmp_len, options.use_dns),
673 (struct sockaddr *)&from, fromlen);
678 * This is called to fork and execute a command. If another command is
679 * to be forced, execute that instead.
682 do_exec(Session *s, const char *command)
684 if (options.adm_forced_command) {
685 original_command = command;
686 command = options.adm_forced_command;
687 debug("Forced command (config) '%.900s'", command);
688 } else if (forced_command) {
689 original_command = command;
690 command = forced_command;
691 debug("Forced command (key option) '%.900s'", command);
694 #ifdef SSH_AUDIT_EVENTS
696 PRIVSEP(audit_run_command(command));
697 else if (s->ttyfd == -1) {
698 char *shell = s->pw->pw_shell;
700 if (shell[0] == '\0') /* empty shell means /bin/sh */
702 PRIVSEP(audit_run_command(shell));
707 do_exec_pty(s, command);
709 do_exec_no_pty(s, command);
711 original_command = NULL;
714 * Clear loginmsg: it's the child's responsibility to display
715 * it to the user, otherwise multiple sessions may accumulate
716 * multiple copies of the login messages.
718 buffer_clear(&loginmsg);
721 /* administrative, login(1)-like work */
723 do_login(Session *s, const char *command)
726 struct sockaddr_storage from;
727 struct passwd * pw = s->pw;
728 pid_t pid = getpid();
731 * Get IP address of client. If the connection is not a socket, let
732 * the address be 0.0.0.0.
734 memset(&from, 0, sizeof(from));
735 fromlen = sizeof(from);
736 if (packet_connection_is_on_socket()) {
737 if (getpeername(packet_get_connection_in(),
738 (struct sockaddr *) & from, &fromlen) < 0) {
739 debug("getpeername: %.100s", strerror(errno));
744 /* Record that there was a login on that tty from the remote host. */
746 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
747 get_remote_name_or_ip(utmp_len,
749 (struct sockaddr *)&from, fromlen);
753 * If password change is needed, do it now.
754 * This needs to occur before the ~/.hushlogin check.
756 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
759 s->authctxt->force_pwchange = 0;
760 /* XXX - signal [net] parent to enable forwardings */
764 if (check_quietlogin(s, command))
773 * Display the message of the day.
780 #ifdef HAVE_LOGIN_CAP
784 #ifdef HAVE_LOGIN_CAP
785 fname = login_getcapstr(lc, "copyright", NULL, NULL);
786 if (fname != NULL && (f = fopen(fname, "r")) != NULL) {
787 while (fgets(buf, sizeof(buf), f) != NULL)
791 #endif /* HAVE_LOGIN_CAP */
792 (void)printf("%s\n\t%s %s\n",
793 "Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994",
794 "The Regents of the University of California. ",
795 "All rights reserved.");
799 if (options.print_motd) {
800 #ifdef HAVE_LOGIN_CAP
801 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
804 f = fopen("/etc/motd", "r");
807 while (fgets(buf, sizeof(buf), f))
816 * Check for quiet login, either .hushlogin or command given.
819 check_quietlogin(Session *s, const char *command)
822 struct passwd *pw = s->pw;
825 /* Return 1 if .hushlogin exists or a command given. */
828 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
829 #ifdef HAVE_LOGIN_CAP
830 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
833 if (stat(buf, &st) >= 0)
840 * Sets the value of the given variable in the environment. If the variable
841 * already exists, its value is overriden.
844 child_set_env(char ***envp, u_int *envsizep, const char *name,
852 * If we're passed an uninitialized list, allocate a single null
853 * entry before continuing.
855 if (*envp == NULL && *envsizep == 0) {
856 *envp = xmalloc(sizeof(char *));
862 * Find the slot where the value should be stored. If the variable
863 * already exists, we reuse the slot; otherwise we append a new slot
864 * at the end of the array, expanding if necessary.
867 namelen = strlen(name);
868 for (i = 0; env[i]; i++)
869 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
872 /* Reuse the slot. */
875 /* New variable. Expand if necessary. */
877 if (i >= envsize - 1) {
879 fatal("child_set_env: too many env vars");
881 env = (*envp) = xrealloc(env, envsize, sizeof(char *));
884 /* Need to set the NULL pointer at end of array beyond the new slot. */
888 /* Allocate space and format the variable in the appropriate slot. */
889 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
890 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
894 * Reads environment variables from the given file and adds/overrides them
895 * into the environment. If the file does not exist, this does nothing.
896 * Otherwise, it must consist of empty lines, comments (line starts with '#')
897 * and assignments of the form name=value. No other forms are allowed.
900 read_environment_file(char ***env, u_int *envsize,
901 const char *filename)
908 f = fopen(filename, "r");
912 while (fgets(buf, sizeof(buf), f)) {
914 fatal("Too many lines in environment file %s", filename);
915 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
917 if (!*cp || *cp == '#' || *cp == '\n')
919 if (strchr(cp, '\n'))
920 *strchr(cp, '\n') = '\0';
921 value = strchr(cp, '=');
923 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
928 * Replace the equals sign by nul, and advance value to
933 child_set_env(env, envsize, cp, value);
938 #ifdef HAVE_ETC_DEFAULT_LOGIN
940 * Return named variable from specified environment, or NULL if not present.
943 child_get_env(char **env, const char *name)
949 for (i=0; env[i] != NULL; i++)
950 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
951 return(env[i] + len + 1);
956 * Read /etc/default/login.
957 * We pick up the PATH (or SUPATH for root) and UMASK.
960 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
962 char **tmpenv = NULL, *var;
963 u_int i, tmpenvsize = 0;
967 * We don't want to copy the whole file to the child's environment,
968 * so we use a temporary environment and copy the variables we're
971 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
977 var = child_get_env(tmpenv, "SUPATH");
979 var = child_get_env(tmpenv, "PATH");
981 child_set_env(env, envsize, "PATH", var);
983 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
984 if (sscanf(var, "%5lo", &mask) == 1)
987 for (i = 0; tmpenv[i] != NULL; i++)
991 #endif /* HAVE_ETC_DEFAULT_LOGIN */
994 copy_environment(char **source, char ***env, u_int *envsize)
996 char *var_name, *var_val;
1002 for(i = 0; source[i] != NULL; i++) {
1003 var_name = xstrdup(source[i]);
1004 if ((var_val = strstr(var_name, "=")) == NULL) {
1010 debug3("Copy environment: %s=%s", var_name, var_val);
1011 child_set_env(env, envsize, var_name, var_val);
1018 do_setup_env(Session *s, const char *shell)
1023 struct passwd *pw = s->pw;
1024 #ifndef HAVE_LOGIN_CAP
1027 extern char **environ;
1031 /* Initialize the environment. */
1033 env = xcalloc(envsize, sizeof(char *));
1038 * The Windows environment contains some setting which are
1039 * important for a running system. They must not be dropped.
1044 p = fetch_windows_environment();
1045 copy_environment(p, &env, &envsize);
1046 free_windows_environment(p);
1051 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1054 /* Allow any GSSAPI methods that we've used to alter
1055 * the childs environment as they see fit
1057 ssh_gssapi_do_child(&env, &envsize);
1060 if (!options.use_login) {
1061 /* Set basic environment. */
1062 for (i = 0; i < s->num_env; i++)
1063 child_set_env(&env, &envsize, s->env[i].name,
1066 child_set_env(&env, &envsize, "USER", pw->pw_name);
1067 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1069 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1071 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1072 snprintf(buf, sizeof buf, "%.200s/%.50s",
1073 _PATH_MAILDIR, pw->pw_name);
1074 child_set_env(&env, &envsize, "MAIL", buf);
1075 #ifdef HAVE_LOGIN_CAP
1076 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1077 child_set_env(&env, &envsize, "TERM", "su");
1079 environ = xmalloc(sizeof(char *));
1081 (void) setusercontext(lc, pw, pw->pw_uid,
1082 LOGIN_SETENV|LOGIN_SETPATH);
1083 copy_environment(environ, &env, &envsize);
1084 for (var = environ; *var != NULL; ++var)
1088 #else /* HAVE_LOGIN_CAP */
1089 # ifndef HAVE_CYGWIN
1091 * There's no standard path on Windows. The path contains
1092 * important components pointing to the system directories,
1093 * needed for loading shared libraries. So the path better
1094 * remains intact here.
1096 # ifdef HAVE_ETC_DEFAULT_LOGIN
1097 read_etc_default_login(&env, &envsize, pw->pw_uid);
1098 path = child_get_env(env, "PATH");
1099 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1100 if (path == NULL || *path == '\0') {
1101 child_set_env(&env, &envsize, "PATH",
1102 s->pw->pw_uid == 0 ?
1103 SUPERUSER_PATH : _PATH_STDPATH);
1105 # endif /* HAVE_CYGWIN */
1106 #endif /* HAVE_LOGIN_CAP */
1108 /* Normal systems set SHELL by default. */
1109 child_set_env(&env, &envsize, "SHELL", shell);
1112 /* Set custom environment options from RSA authentication. */
1113 if (!options.use_login) {
1114 while (custom_environment) {
1115 struct envstring *ce = custom_environment;
1118 for (i = 0; str[i] != '=' && str[i]; i++)
1120 if (str[i] == '=') {
1122 child_set_env(&env, &envsize, str, str + i + 1);
1124 custom_environment = ce->next;
1130 /* SSH_CLIENT deprecated */
1131 snprintf(buf, sizeof buf, "%.50s %d %d",
1132 get_remote_ipaddr(), get_remote_port(), get_local_port());
1133 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1135 laddr = get_local_ipaddr(packet_get_connection_in());
1136 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1137 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1139 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1142 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1144 child_set_env(&env, &envsize, "TERM", s->term);
1146 child_set_env(&env, &envsize, "DISPLAY", s->display);
1147 if (original_command)
1148 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1152 if (cray_tmpdir[0] != '\0')
1153 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1154 #endif /* _UNICOS */
1157 * Since we clear KRB5CCNAME at startup, if it's set now then it
1158 * must have been set by a native authentication method (eg AIX or
1159 * SIA), so copy it to the child.
1164 if ((cp = getenv("KRB5CCNAME")) != NULL)
1165 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1172 if ((cp = getenv("AUTHSTATE")) != NULL)
1173 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1174 read_environment_file(&env, &envsize, "/etc/environment");
1178 if (s->authctxt->krb5_ccname)
1179 child_set_env(&env, &envsize, "KRB5CCNAME",
1180 s->authctxt->krb5_ccname);
1184 * Pull in any environment variables that may have
1187 if (options.use_pam) {
1190 p = fetch_pam_child_environment();
1191 copy_environment(p, &env, &envsize);
1192 free_pam_environment(p);
1194 p = fetch_pam_environment();
1195 copy_environment(p, &env, &envsize);
1196 free_pam_environment(p);
1198 #endif /* USE_PAM */
1200 if (auth_sock_name != NULL)
1201 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1204 /* read $HOME/.ssh/environment. */
1205 if (options.permit_user_env && !options.use_login) {
1206 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1207 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1208 read_environment_file(&env, &envsize, buf);
1211 /* dump the environment */
1212 fprintf(stderr, "Environment:\n");
1213 for (i = 0; env[i]; i++)
1214 fprintf(stderr, " %.200s\n", env[i]);
1220 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1221 * first in this order).
1224 do_rc_files(Session *s, const char *shell)
1232 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1234 /* ignore _PATH_SSH_USER_RC for subsystems */
1235 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1236 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1237 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1239 fprintf(stderr, "Running %s\n", cmd);
1240 f = popen(cmd, "w");
1243 fprintf(f, "%s %s\n", s->auth_proto,
1247 fprintf(stderr, "Could not run %s\n",
1249 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1251 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1252 _PATH_SSH_SYSTEM_RC);
1253 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1256 fprintf(f, "%s %s\n", s->auth_proto,
1260 fprintf(stderr, "Could not run %s\n",
1261 _PATH_SSH_SYSTEM_RC);
1262 } else if (do_xauth && options.xauth_location != NULL) {
1263 /* Add authority data to .Xauthority if appropriate. */
1266 "Running %.500s remove %.100s\n",
1267 options.xauth_location, s->auth_display);
1269 "%.500s add %.100s %.100s %.100s\n",
1270 options.xauth_location, s->auth_display,
1271 s->auth_proto, s->auth_data);
1273 snprintf(cmd, sizeof cmd, "%s -q -",
1274 options.xauth_location);
1275 f = popen(cmd, "w");
1277 fprintf(f, "remove %s\n",
1279 fprintf(f, "add %s %s %s\n",
1280 s->auth_display, s->auth_proto,
1284 fprintf(stderr, "Could not run %s\n",
1291 do_nologin(struct passwd *pw)
1296 #ifdef HAVE_LOGIN_CAP
1297 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1298 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1299 _PATH_NOLOGIN), "r");
1302 f = fopen(_PATH_NOLOGIN, "r");
1305 /* /etc/nologin exists. Print its contents and exit. */
1306 logit("User %.100s not allowed because %s exists",
1307 pw->pw_name, _PATH_NOLOGIN);
1308 while (fgets(buf, sizeof(buf), f))
1316 /* Set login name, uid, gid, and groups. */
1318 do_setusercontext(struct passwd *pw)
1321 if (getuid() == 0 || geteuid() == 0)
1322 #endif /* HAVE_CYGWIN */
1325 #ifdef HAVE_SETPCRED
1326 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1327 fatal("Failed to set process credentials");
1328 #endif /* HAVE_SETPCRED */
1329 #ifdef HAVE_LOGIN_CAP
1334 if (options.gss_authentication) {
1335 temporarily_use_uid(pw);
1336 ssh_gssapi_storecreds();
1341 if (options.use_pam) {
1345 # endif /* USE_PAM */
1346 if (setusercontext(lc, pw, pw->pw_uid,
1347 (LOGIN_SETALL & ~(LOGIN_SETENV|LOGIN_SETPATH))) < 0) {
1348 perror("unable to set user context");
1352 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1353 /* Sets login uid for accounting */
1354 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1355 error("setluid: %s", strerror(errno));
1356 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1358 if (setlogin(pw->pw_name) < 0)
1359 error("setlogin failed: %s", strerror(errno));
1360 if (setgid(pw->pw_gid) < 0) {
1364 /* Initialize the group list. */
1365 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1366 perror("initgroups");
1371 if (options.gss_authentication) {
1372 temporarily_use_uid(pw);
1373 ssh_gssapi_storecreds();
1379 * PAM credentials may take the form of supplementary groups.
1380 * These will have been wiped by the above initgroups() call.
1381 * Reestablish them here.
1383 if (options.use_pam) {
1387 # endif /* USE_PAM */
1388 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1389 irix_setusercontext(pw);
1390 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1394 #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
1395 if (set_id(pw->pw_name) != 0) {
1398 #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
1399 /* Permanently switch to the desired uid. */
1400 permanently_set_uid(pw);
1407 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1408 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1411 ssh_selinux_setup_exec_context(pw->pw_name);
1416 do_pwchange(Session *s)
1419 fprintf(stderr, "WARNING: Your password has expired.\n");
1420 if (s->ttyfd != -1) {
1422 "You must change your password now and login again!\n");
1423 #ifdef PASSWD_NEEDS_USERNAME
1424 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1427 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1432 "Password change required but no TTY available.\n");
1438 launch_login(struct passwd *pw, const char *hostname)
1440 /* Launch login(1). */
1442 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1443 #ifdef xxxLOGIN_NEEDS_TERM
1444 (s->term ? s->term : "unknown"),
1445 #endif /* LOGIN_NEEDS_TERM */
1446 #ifdef LOGIN_NO_ENDOPT
1447 "-p", "-f", pw->pw_name, (char *)NULL);
1449 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1452 /* Login couldn't be executed, die. */
1459 child_close_fds(void)
1463 if (packet_get_connection_in() == packet_get_connection_out())
1464 close(packet_get_connection_in());
1466 close(packet_get_connection_in());
1467 close(packet_get_connection_out());
1470 * Close all descriptors related to channels. They will still remain
1471 * open in the parent.
1473 /* XXX better use close-on-exec? -markus */
1474 channel_close_all();
1477 * Close any extra file descriptors. Note that there may still be
1478 * descriptors left by system functions. They will be closed later.
1483 * Close any extra open file descriptors so that we don't have them
1484 * hanging around in clients. Note that we want to do this after
1485 * initgroups, because at least on Solaris 2.3 it leaves file
1488 for (i = 3; i < 64; i++)
1493 * Performs common processing for the child, such as setting up the
1494 * environment, closing extra file descriptors, setting the user and group
1495 * ids, and executing the command or shell.
1498 do_child(Session *s, const char *command)
1500 extern char **environ;
1503 const char *shell, *shell0, *hostname = NULL;
1504 struct passwd *pw = s->pw;
1505 #ifdef HAVE_LOGIN_CAP
1509 /* remove hostkey from the child's memory */
1510 destroy_sensitive_data();
1512 /* Force a password change */
1513 if (s->authctxt->force_pwchange) {
1514 do_setusercontext(pw);
1520 /* login(1) is only called if we execute the login shell */
1521 if (options.use_login && command != NULL)
1522 options.use_login = 0;
1525 cray_setup(pw->pw_uid, pw->pw_name, command);
1526 #endif /* _UNICOS */
1529 * Login(1) does this as well, and it needs uid 0 for the "-h"
1530 * switch, so we let login(1) to this for us.
1532 if (!options.use_login) {
1534 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1535 if (!check_quietlogin(s, command))
1537 #else /* HAVE_OSF_SIA */
1538 /* When PAM is enabled we rely on it to do the nologin check */
1539 if (!options.use_pam)
1541 do_setusercontext(pw);
1543 * PAM session modules in do_setusercontext may have
1544 * generated messages, so if this in an interactive
1545 * login then display them too.
1547 if (!check_quietlogin(s, command))
1549 #endif /* HAVE_OSF_SIA */
1553 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1554 debug3("PAM session not opened, exiting");
1561 * Get the shell from the password data. An empty shell field is
1562 * legal, and means /bin/sh.
1564 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1567 * Make sure $SHELL points to the shell from the password file,
1568 * even if shell is overridden from login.conf
1570 env = do_setup_env(s, shell);
1572 #ifdef HAVE_LOGIN_CAP
1573 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1576 /* we have to stash the hostname before we close our socket. */
1577 if (options.use_login)
1578 hostname = get_remote_name_or_ip(utmp_len,
1581 * Close the connection descriptors; note that this is the child, and
1582 * the server will still have the socket open, and it is important
1583 * that we do not shutdown it. Note that the descriptors cannot be
1584 * closed before building the environment, as we call
1585 * get_remote_ipaddr there.
1590 * Must take new environment into use so that .ssh/rc,
1591 * /etc/ssh/sshrc and xauth are run in the proper environment.
1595 #ifdef HAVE_LOGIN_CAP
1596 lc_requirehome = login_getcapbool(lc, "requirehome", 0);
1599 #if defined(KRB5) && defined(USE_AFS)
1601 * At this point, we check to see if AFS is active and if we have
1602 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1603 * if we can (and need to) extend the ticket into an AFS token. If
1604 * we don't do this, we run into potential problems if the user's
1605 * home directory is in AFS and it's not world-readable.
1608 if (options.kerberos_get_afs_token && k_hasafs() &&
1609 (s->authctxt->krb5_ctx != NULL)) {
1612 debug("Getting AFS token");
1616 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1617 krb5_afslog(s->authctxt->krb5_ctx,
1618 s->authctxt->krb5_fwd_ccache, cell, NULL);
1620 krb5_afslog_home(s->authctxt->krb5_ctx,
1621 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1625 /* Change current directory to the user's home directory. */
1626 if (chdir(pw->pw_dir) < 0) {
1627 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1628 pw->pw_dir, strerror(errno));
1629 #ifdef HAVE_LOGIN_CAP
1635 if (!options.use_login)
1636 do_rc_files(s, shell);
1638 /* restore SIGPIPE for child */
1639 signal(SIGPIPE, SIG_DFL);
1641 if (options.use_login) {
1642 launch_login(pw, hostname);
1646 /* Get the last component of the shell name. */
1647 if ((shell0 = strrchr(shell, '/')) != NULL)
1653 * If we have no command, execute the shell. In this case, the shell
1654 * name to be passed in argv[0] is preceded by '-' to indicate that
1655 * this is a login shell.
1660 /* Start the shell. Set initial character to '-'. */
1663 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1664 >= sizeof(argv0) - 1) {
1670 /* Execute the shell. */
1673 execve(shell, argv, env);
1675 /* Executing the shell failed. */
1680 * Execute the command using the user's shell. This uses the -c
1681 * option to execute the command.
1683 argv[0] = (char *) shell0;
1685 argv[2] = (char *) command;
1687 execve(shell, argv, env);
1696 static int did_init = 0;
1698 debug("session_new: init");
1699 for (i = 0; i < MAX_SESSIONS; i++) {
1700 sessions[i].used = 0;
1704 for (i = 0; i < MAX_SESSIONS; i++) {
1705 Session *s = &sessions[i];
1707 memset(s, 0, sizeof(*s));
1713 s->x11_chanids = NULL;
1714 debug("session_new: session %d", i);
1725 for (i = 0; i < MAX_SESSIONS; i++) {
1726 Session *s = &sessions[i];
1727 debug("dump: used %d session %d %p channel %d pid %ld",
1737 session_open(Authctxt *authctxt, int chanid)
1739 Session *s = session_new();
1740 debug("session_open: channel %d", chanid);
1742 error("no more sessions");
1745 s->authctxt = authctxt;
1746 s->pw = authctxt->pw;
1747 if (s->pw == NULL || !authctxt->valid)
1748 fatal("no user for session %d", s->self);
1749 debug("session_open: session %d: link with channel %d", s->self, chanid);
1755 session_by_tty(char *tty)
1758 for (i = 0; i < MAX_SESSIONS; i++) {
1759 Session *s = &sessions[i];
1760 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1761 debug("session_by_tty: session %d tty %s", i, tty);
1765 debug("session_by_tty: unknown tty %.100s", tty);
1771 session_by_channel(int id)
1774 for (i = 0; i < MAX_SESSIONS; i++) {
1775 Session *s = &sessions[i];
1776 if (s->used && s->chanid == id) {
1777 debug("session_by_channel: session %d channel %d", i, id);
1781 debug("session_by_channel: unknown channel %d", id);
1787 session_by_x11_channel(int id)
1791 for (i = 0; i < MAX_SESSIONS; i++) {
1792 Session *s = &sessions[i];
1794 if (s->x11_chanids == NULL || !s->used)
1796 for (j = 0; s->x11_chanids[j] != -1; j++) {
1797 if (s->x11_chanids[j] == id) {
1798 debug("session_by_x11_channel: session %d "
1799 "channel %d", s->self, id);
1804 debug("session_by_x11_channel: unknown channel %d", id);
1810 session_by_pid(pid_t pid)
1813 debug("session_by_pid: pid %ld", (long)pid);
1814 for (i = 0; i < MAX_SESSIONS; i++) {
1815 Session *s = &sessions[i];
1816 if (s->used && s->pid == pid)
1819 error("session_by_pid: unknown pid %ld", (long)pid);
1825 session_window_change_req(Session *s)
1827 s->col = packet_get_int();
1828 s->row = packet_get_int();
1829 s->xpixel = packet_get_int();
1830 s->ypixel = packet_get_int();
1832 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1837 session_pty_req(Session *s)
1843 debug("Allocating a pty not permitted for this authentication.");
1846 if (s->ttyfd != -1) {
1847 packet_disconnect("Protocol error: you already have a pty.");
1851 s->term = packet_get_string(&len);
1854 s->col = packet_get_int();
1855 s->row = packet_get_int();
1857 s->row = packet_get_int();
1858 s->col = packet_get_int();
1860 s->xpixel = packet_get_int();
1861 s->ypixel = packet_get_int();
1863 if (strcmp(s->term, "") == 0) {
1868 /* Allocate a pty and open it. */
1869 debug("Allocating pty.");
1870 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1876 error("session_pty_req: session %d alloc failed", s->self);
1879 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1881 /* for SSH1 the tty modes length is not given */
1883 n_bytes = packet_remaining();
1884 tty_parse_modes(s->ttyfd, &n_bytes);
1887 pty_setowner(s->pw, s->tty);
1889 /* Set window size from the packet. */
1890 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1893 session_proctitle(s);
1898 session_subsystem_req(Session *s)
1903 char *prog, *cmd, *subsys = packet_get_string(&len);
1907 logit("subsystem request for %.100s", subsys);
1909 for (i = 0; i < options.num_subsystems; i++) {
1910 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1911 prog = options.subsystem_command[i];
1912 cmd = options.subsystem_args[i];
1913 if (stat(prog, &st) < 0) {
1914 error("subsystem: cannot stat %s: %s", prog,
1918 debug("subsystem: exec() %s", cmd);
1919 s->is_subsystem = 1;
1927 logit("subsystem request for %.100s failed, subsystem not found",
1935 session_x11_req(Session *s)
1939 if (s->auth_proto != NULL || s->auth_data != NULL) {
1940 error("session_x11_req: session %d: "
1941 "x11 forwarding already active", s->self);
1944 s->single_connection = packet_get_char();
1945 s->auth_proto = packet_get_string(NULL);
1946 s->auth_data = packet_get_string(NULL);
1947 s->screen = packet_get_int();
1950 success = session_setup_x11fwd(s);
1952 xfree(s->auth_proto);
1953 xfree(s->auth_data);
1954 s->auth_proto = NULL;
1955 s->auth_data = NULL;
1961 session_shell_req(Session *s)
1969 session_exec_req(Session *s)
1972 char *command = packet_get_string(&len);
1974 do_exec(s, command);
1980 session_break_req(Session *s)
1983 packet_get_int(); /* ignored */
1986 if (s->ttyfd == -1 ||
1987 tcsendbreak(s->ttyfd, 0) < 0)
1993 session_env_req(Session *s)
1996 u_int name_len, val_len, i;
1998 name = packet_get_string(&name_len);
1999 val = packet_get_string(&val_len);
2002 /* Don't set too many environment variables */
2003 if (s->num_env > 128) {
2004 debug2("Ignoring env request %s: too many env vars", name);
2008 for (i = 0; i < options.num_accept_env; i++) {
2009 if (match_pattern(name, options.accept_env[i])) {
2010 debug2("Setting env %d: %s=%s", s->num_env, name, val);
2011 s->env = xrealloc(s->env, s->num_env + 1,
2013 s->env[s->num_env].name = name;
2014 s->env[s->num_env].val = val;
2019 debug2("Ignoring env request %s: disallowed name", name);
2028 session_auth_agent_req(Session *s)
2030 static int called = 0;
2032 if (no_agent_forwarding_flag) {
2033 debug("session_auth_agent_req: no_agent_forwarding_flag");
2040 return auth_input_request_forwarding(s->pw);
2045 session_input_channel_req(Channel *c, const char *rtype)
2050 if ((s = session_by_channel(c->self)) == NULL) {
2051 logit("session_input_channel_req: no session %d req %.100s",
2055 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2058 * a session is in LARVAL state until a shell, a command
2059 * or a subsystem is executed
2061 if (c->type == SSH_CHANNEL_LARVAL) {
2062 if (strcmp(rtype, "shell") == 0) {
2063 success = session_shell_req(s);
2064 } else if (strcmp(rtype, "exec") == 0) {
2065 success = session_exec_req(s);
2066 } else if (strcmp(rtype, "pty-req") == 0) {
2067 success = session_pty_req(s);
2068 } else if (strcmp(rtype, "x11-req") == 0) {
2069 success = session_x11_req(s);
2070 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2071 success = session_auth_agent_req(s);
2072 } else if (strcmp(rtype, "subsystem") == 0) {
2073 success = session_subsystem_req(s);
2074 } else if (strcmp(rtype, "env") == 0) {
2075 success = session_env_req(s);
2078 if (strcmp(rtype, "window-change") == 0) {
2079 success = session_window_change_req(s);
2080 } else if (strcmp(rtype, "break") == 0) {
2081 success = session_break_req(s);
2088 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2091 fatal("session_set_fds: called for proto != 2.0");
2093 * now that have a child and a pipe to the child,
2094 * we can activate our channel and register the fd's
2096 if (s->chanid == -1)
2097 fatal("no channel for session %d", s->self);
2098 channel_set_fds(s->chanid,
2100 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2102 CHAN_SES_WINDOW_DEFAULT);
2106 * Function to perform pty cleanup. Also called if we get aborted abnormally
2107 * (e.g., due to a dropped connection).
2110 session_pty_cleanup2(Session *s)
2113 error("session_pty_cleanup: no session");
2119 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2121 /* Record that the user has logged out. */
2123 record_logout(s->pid, s->tty, s->pw->pw_name);
2125 /* Release the pseudo-tty. */
2127 pty_release(s->tty);
2130 * Close the server side of the socket pairs. We must do this after
2131 * the pty cleanup, so that another process doesn't get this pty
2132 * while we're still cleaning up.
2134 if (close(s->ptymaster) < 0)
2135 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2137 /* unlink pty from session */
2142 session_pty_cleanup(Session *s)
2144 PRIVSEP(session_pty_cleanup2(s));
2150 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2165 return "SIG@openssh.com";
2169 session_close_x11(int id)
2173 if ((c = channel_by_id(id)) == NULL) {
2174 debug("session_close_x11: x11 channel %d missing", id);
2176 /* Detach X11 listener */
2177 debug("session_close_x11: detach x11 channel %d", id);
2178 channel_cancel_cleanup(id);
2179 if (c->ostate != CHAN_OUTPUT_CLOSED)
2185 session_close_single_x11(int id, void *arg)
2190 debug3("session_close_single_x11: channel %d", id);
2191 channel_cancel_cleanup(id);
2192 if ((s = session_by_x11_channel(id)) == NULL)
2193 fatal("session_close_single_x11: no x11 channel %d", id);
2194 for (i = 0; s->x11_chanids[i] != -1; i++) {
2195 debug("session_close_single_x11: session %d: "
2196 "closing channel %d", s->self, s->x11_chanids[i]);
2198 * The channel "id" is already closing, but make sure we
2199 * close all of its siblings.
2201 if (s->x11_chanids[i] != id)
2202 session_close_x11(s->x11_chanids[i]);
2204 xfree(s->x11_chanids);
2205 s->x11_chanids = NULL;
2210 if (s->auth_proto) {
2211 xfree(s->auth_proto);
2212 s->auth_proto = NULL;
2215 xfree(s->auth_data);
2216 s->auth_data = NULL;
2218 if (s->auth_display) {
2219 xfree(s->auth_display);
2220 s->auth_display = NULL;
2225 session_exit_message(Session *s, int status)
2229 if ((c = channel_lookup(s->chanid)) == NULL)
2230 fatal("session_exit_message: session %d: no channel %d",
2231 s->self, s->chanid);
2232 debug("session_exit_message: session %d channel %d pid %ld",
2233 s->self, s->chanid, (long)s->pid);
2235 if (WIFEXITED(status)) {
2236 channel_request_start(s->chanid, "exit-status", 0);
2237 packet_put_int(WEXITSTATUS(status));
2239 } else if (WIFSIGNALED(status)) {
2240 channel_request_start(s->chanid, "exit-signal", 0);
2241 packet_put_cstring(sig2name(WTERMSIG(status)));
2243 packet_put_char(WCOREDUMP(status));
2244 #else /* WCOREDUMP */
2246 #endif /* WCOREDUMP */
2247 packet_put_cstring("");
2248 packet_put_cstring("");
2251 /* Some weird exit cause. Just exit. */
2252 packet_disconnect("wait returned status %04x.", status);
2255 /* disconnect channel */
2256 debug("session_exit_message: release channel %d", s->chanid);
2259 * Adjust cleanup callback attachment to send close messages when
2260 * the channel gets EOF. The session will be then be closed
2261 * by session_close_by_channel when the childs close their fds.
2263 channel_register_cleanup(c->self, session_close_by_channel, 1);
2266 * emulate a write failure with 'chan_write_failed', nobody will be
2267 * interested in data we write.
2268 * Note that we must not call 'chan_read_failed', since there could
2269 * be some more data waiting in the pipe.
2271 if (c->ostate != CHAN_OUTPUT_CLOSED)
2272 chan_write_failed(c);
2276 session_close(Session *s)
2280 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2282 session_pty_cleanup(s);
2288 xfree(s->x11_chanids);
2289 if (s->auth_display)
2290 xfree(s->auth_display);
2292 xfree(s->auth_data);
2294 xfree(s->auth_proto);
2296 if (s->env != NULL) {
2297 for (i = 0; i < s->num_env; i++) {
2298 xfree(s->env[i].name);
2299 xfree(s->env[i].val);
2303 session_proctitle(s);
2307 session_close_by_pid(pid_t pid, int status)
2309 Session *s = session_by_pid(pid);
2311 debug("session_close_by_pid: no session for pid %ld",
2315 if (s->chanid != -1)
2316 session_exit_message(s, status);
2318 session_pty_cleanup(s);
2323 * this is called when a channel dies before
2324 * the session 'child' itself dies
2327 session_close_by_channel(int id, void *arg)
2329 Session *s = session_by_channel(id);
2333 debug("session_close_by_channel: no session for id %d", id);
2336 debug("session_close_by_channel: channel %d child %ld",
2339 debug("session_close_by_channel: channel %d: has child", id);
2341 * delay detach of session, but release pty, since
2342 * the fd's to the child are already closed
2345 session_pty_cleanup(s);
2348 /* detach by removing callback */
2349 channel_cancel_cleanup(s->chanid);
2351 /* Close any X11 listeners associated with this session */
2352 if (s->x11_chanids != NULL) {
2353 for (i = 0; s->x11_chanids[i] != -1; i++) {
2354 session_close_x11(s->x11_chanids[i]);
2355 s->x11_chanids[i] = -1;
2364 session_destroy_all(void (*closefunc)(Session *))
2367 for (i = 0; i < MAX_SESSIONS; i++) {
2368 Session *s = &sessions[i];
2370 if (closefunc != NULL)
2379 session_tty_list(void)
2381 static char buf[1024];
2386 for (i = 0; i < MAX_SESSIONS; i++) {
2387 Session *s = &sessions[i];
2388 if (s->used && s->ttyfd != -1) {
2390 if (strncmp(s->tty, "/dev/", 5) != 0) {
2391 cp = strrchr(s->tty, '/');
2392 cp = (cp == NULL) ? s->tty : cp + 1;
2397 strlcat(buf, ",", sizeof buf);
2398 strlcat(buf, cp, sizeof buf);
2402 strlcpy(buf, "notty", sizeof buf);
2407 session_proctitle(Session *s)
2410 error("no user for session %d", s->self);
2412 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2416 session_setup_x11fwd(Session *s)
2419 char display[512], auth_display[512];
2420 char hostname[MAXHOSTNAMELEN];
2423 if (no_x11_forwarding_flag) {
2424 packet_send_debug("X11 forwarding disabled in user configuration file.");
2427 if (!options.x11_forwarding) {
2428 debug("X11 forwarding disabled in server configuration file.");
2431 if (!options.xauth_location ||
2432 (stat(options.xauth_location, &st) == -1)) {
2433 packet_send_debug("No xauth program; cannot forward with spoofing.");
2436 if (options.use_login) {
2437 packet_send_debug("X11 forwarding disabled; "
2438 "not compatible with UseLogin=yes.");
2441 if (s->display != NULL) {
2442 debug("X11 display already set.");
2445 if (x11_create_display_inet(options.x11_display_offset,
2446 options.x11_use_localhost, s->single_connection,
2447 &s->display_number, &s->x11_chanids) == -1) {
2448 debug("x11_create_display_inet failed.");
2451 for (i = 0; s->x11_chanids[i] != -1; i++) {
2452 channel_register_cleanup(s->x11_chanids[i],
2453 session_close_single_x11, 0);
2456 /* Set up a suitable value for the DISPLAY variable. */
2457 if (gethostname(hostname, sizeof(hostname)) < 0)
2458 fatal("gethostname: %.100s", strerror(errno));
2460 * auth_display must be used as the displayname when the
2461 * authorization entry is added with xauth(1). This will be
2462 * different than the DISPLAY string for localhost displays.
2464 if (options.x11_use_localhost) {
2465 snprintf(display, sizeof display, "localhost:%u.%u",
2466 s->display_number, s->screen);
2467 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2468 s->display_number, s->screen);
2469 s->display = xstrdup(display);
2470 s->auth_display = xstrdup(auth_display);
2472 #ifdef IPADDR_IN_DISPLAY
2474 struct in_addr my_addr;
2476 he = gethostbyname(hostname);
2478 error("Can't get IP address for X11 DISPLAY.");
2479 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2482 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2483 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2484 s->display_number, s->screen);
2486 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2487 s->display_number, s->screen);
2489 s->display = xstrdup(display);
2490 s->auth_display = xstrdup(display);
2497 do_authenticated2(Authctxt *authctxt)
2499 server_loop2(authctxt);
2503 do_cleanup(Authctxt *authctxt)
2505 static int called = 0;
2507 debug("do_cleanup");
2509 /* no cleanup if we're in the child for login shell */
2513 /* avoid double cleanup */
2518 if (authctxt == NULL || !authctxt->authenticated)
2521 if (options.kerberos_ticket_cleanup &&
2523 krb5_cleanup_proc(authctxt);
2527 if (compat20 && options.gss_cleanup_creds)
2528 ssh_gssapi_cleanup_creds();
2532 if (options.use_pam) {
2534 sshpam_thread_cleanup();
2538 /* remove agent socket */
2539 auth_sock_cleanup_proc(authctxt->pw);
2542 * Cleanup ptys/utmp only if privsep is disabled,
2543 * or if running in monitor.
2545 if (!use_privsep || mm_is_monitor())
2546 session_destroy_all(session_pty_cleanup2);