1 /* $OpenBSD: session.c,v 1.245 2009/01/22 09:46:01 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>
63 #include "openbsd-compat/sys-queue.h"
82 #include "auth-options.h"
83 #include "pathnames.h"
87 #include "serverloop.h"
92 #include "monitor_wrap.h"
95 #if defined(KRB5) && defined(USE_AFS)
99 #define IS_INTERNAL_SFTP(c) \
100 (!strncmp(c, INTERNAL_SFTP_NAME, sizeof(INTERNAL_SFTP_NAME) - 1) && \
101 (c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\0' || \
102 c[sizeof(INTERNAL_SFTP_NAME) - 1] == ' ' || \
103 c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\t'))
107 Session *session_new(void);
108 void session_set_fds(Session *, int, int, int, int);
109 void session_pty_cleanup(Session *);
110 void session_proctitle(Session *);
111 int session_setup_x11fwd(Session *);
112 int do_exec_pty(Session *, const char *);
113 int do_exec_no_pty(Session *, const char *);
114 int do_exec(Session *, const char *);
115 void do_login(Session *, const char *);
116 #ifdef LOGIN_NEEDS_UTMPX
117 static void do_pre_login(Session *s);
119 void do_child(Session *, const char *);
121 int check_quietlogin(Session *, const char *);
123 static void do_authenticated1(Authctxt *);
124 static void do_authenticated2(Authctxt *);
126 static int session_pty_req(Session *);
129 extern ServerOptions options;
130 extern char *__progname;
131 extern int log_stderr;
132 extern int debug_flag;
133 extern u_int utmp_len;
134 extern int startup_pipe;
135 extern void destroy_sensitive_data(void);
136 extern Buffer loginmsg;
138 /* original command from peer. */
139 const char *original_command = NULL;
142 static int sessions_first_unused = -1;
143 static int sessions_nalloc = 0;
144 static Session *sessions = NULL;
146 #define SUBSYSTEM_NONE 0
147 #define SUBSYSTEM_EXT 1
148 #define SUBSYSTEM_INT_SFTP 2
150 #ifdef HAVE_LOGIN_CAP
154 static int is_child = 0;
156 /* Name and directory of socket for authentication agent forwarding. */
157 static char *auth_sock_name = NULL;
158 static char *auth_sock_dir = NULL;
160 /* removes the agent forwarding socket */
163 auth_sock_cleanup_proc(struct passwd *pw)
165 if (auth_sock_name != NULL) {
166 temporarily_use_uid(pw);
167 unlink(auth_sock_name);
168 rmdir(auth_sock_dir);
169 auth_sock_name = NULL;
175 auth_input_request_forwarding(struct passwd * pw)
179 struct sockaddr_un sunaddr;
181 if (auth_sock_name != NULL) {
182 error("authentication forwarding requested twice.");
186 /* Temporarily drop privileged uid for mkdir/bind. */
187 temporarily_use_uid(pw);
189 /* Allocate a buffer for the socket name, and format the name. */
190 auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX");
192 /* Create private directory for socket */
193 if (mkdtemp(auth_sock_dir) == NULL) {
194 packet_send_debug("Agent forwarding disabled: "
195 "mkdtemp() failed: %.100s", strerror(errno));
197 xfree(auth_sock_dir);
198 auth_sock_dir = NULL;
202 xasprintf(&auth_sock_name, "%s/agent.%ld",
203 auth_sock_dir, (long) getpid());
205 /* Create the socket. */
206 sock = socket(AF_UNIX, SOCK_STREAM, 0);
208 error("socket: %.100s", strerror(errno));
213 /* Bind it to the name. */
214 memset(&sunaddr, 0, sizeof(sunaddr));
215 sunaddr.sun_family = AF_UNIX;
216 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
218 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
219 error("bind: %.100s", strerror(errno));
224 /* Restore the privileged uid. */
227 /* Start listening on the socket. */
228 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
229 error("listen: %.100s", strerror(errno));
233 /* Allocate a channel for the authentication agent socket. */
234 nc = channel_new("auth socket",
235 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
236 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
237 0, "auth socket", 1);
238 nc->path = xstrdup(auth_sock_name);
242 if (auth_sock_name != NULL)
243 xfree(auth_sock_name);
244 if (auth_sock_dir != NULL) {
245 rmdir(auth_sock_dir);
246 xfree(auth_sock_dir);
250 auth_sock_name = NULL;
251 auth_sock_dir = NULL;
256 display_loginmsg(void)
258 if (buffer_len(&loginmsg) > 0) {
259 buffer_append(&loginmsg, "\0", 1);
260 printf("%s", (char *)buffer_ptr(&loginmsg));
261 buffer_clear(&loginmsg);
266 do_authenticated(Authctxt *authctxt)
268 setproctitle("%s", authctxt->pw->pw_name);
270 /* setup the channel layer */
271 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
272 channel_permit_all_opens();
275 do_authenticated2(authctxt);
277 do_authenticated1(authctxt);
279 do_cleanup(authctxt);
283 * Prepares for an interactive session. This is called after the user has
284 * been successfully authenticated. During this message exchange, pseudo
285 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
286 * are requested, etc.
289 do_authenticated1(Authctxt *authctxt)
293 int success, type, screen_flag;
294 int enable_compression_after_reply = 0;
295 u_int proto_len, data_len, dlen, compression_level = 0;
299 error("no more sessions");
302 s->authctxt = authctxt;
303 s->pw = authctxt->pw;
306 * We stay in this loop until the client requests to execute a shell
312 /* Get a packet from the client. */
313 type = packet_read();
315 /* Process the packet. */
317 case SSH_CMSG_REQUEST_COMPRESSION:
318 compression_level = packet_get_int();
320 if (compression_level < 1 || compression_level > 9) {
321 packet_send_debug("Received invalid compression level %d.",
325 if (options.compression == COMP_NONE) {
326 debug2("compression disabled");
329 /* Enable compression after we have responded with SUCCESS. */
330 enable_compression_after_reply = 1;
334 case SSH_CMSG_REQUEST_PTY:
335 success = session_pty_req(s);
338 case SSH_CMSG_X11_REQUEST_FORWARDING:
339 s->auth_proto = packet_get_string(&proto_len);
340 s->auth_data = packet_get_string(&data_len);
342 screen_flag = packet_get_protocol_flags() &
343 SSH_PROTOFLAG_SCREEN_NUMBER;
344 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
346 if (packet_remaining() == 4) {
348 debug2("Buggy client: "
349 "X11 screen flag missing");
350 s->screen = packet_get_int();
355 success = session_setup_x11fwd(s);
357 xfree(s->auth_proto);
359 s->auth_proto = NULL;
364 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
365 if (!options.allow_agent_forwarding ||
366 no_agent_forwarding_flag || compat13) {
367 debug("Authentication agent forwarding not permitted for this authentication.");
370 debug("Received authentication agent forwarding request.");
371 success = auth_input_request_forwarding(s->pw);
374 case SSH_CMSG_PORT_FORWARD_REQUEST:
375 if (no_port_forwarding_flag) {
376 debug("Port forwarding not permitted for this authentication.");
379 if (!options.allow_tcp_forwarding) {
380 debug("Port forwarding not permitted.");
383 debug("Received TCP/IP port forwarding request.");
384 if (channel_input_port_forward_request(s->pw->pw_uid == 0,
385 options.gateway_ports) < 0) {
386 debug("Port forwarding failed.");
392 case SSH_CMSG_MAX_PACKET_SIZE:
393 if (packet_set_maxsize(packet_get_int()) > 0)
397 case SSH_CMSG_EXEC_SHELL:
398 case SSH_CMSG_EXEC_CMD:
399 if (type == SSH_CMSG_EXEC_CMD) {
400 command = packet_get_string(&dlen);
401 debug("Exec command '%.500s'", command);
402 if (do_exec(s, command) != 0)
404 "command execution failed");
407 if (do_exec(s, NULL) != 0)
409 "shell execution failed");
417 * Any unknown messages in this phase are ignored,
418 * and a failure message is returned.
420 logit("Unknown packet type received after authentication: %d", type);
422 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
426 /* Enable compression now that we have replied if appropriate. */
427 if (enable_compression_after_reply) {
428 enable_compression_after_reply = 0;
429 packet_start_compression(compression_level);
436 * This is called to fork and execute a command when we have no tty. This
437 * will call do_child from the child, and server_loop from the parent after
438 * setting up file descriptors and such.
441 do_exec_no_pty(Session *s, const char *command)
446 int pin[2], pout[2], perr[2];
448 /* Allocate pipes for communicating with the program. */
450 error("%s: pipe in: %.100s", __func__, strerror(errno));
453 if (pipe(pout) < 0) {
454 error("%s: pipe out: %.100s", __func__, strerror(errno));
459 if (pipe(perr) < 0) {
460 error("%s: pipe err: %.100s", __func__, strerror(errno));
468 int inout[2], err[2];
470 /* Uses socket pairs to communicate with the program. */
471 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0) {
472 error("%s: socketpair #1: %.100s", __func__, strerror(errno));
475 if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) {
476 error("%s: socketpair #2: %.100s", __func__, strerror(errno));
484 fatal("do_exec_no_pty: no session");
486 session_proctitle(s);
488 /* Fork the child. */
489 switch ((pid = fork())) {
491 error("%s: fork: %.100s", __func__, strerror(errno));
509 /* Child. Reinitialize the log since the pid has changed. */
510 log_init(__progname, options.log_level,
511 options.log_facility, log_stderr);
514 * Create a new session and process group since the 4.4BSD
515 * setlogin() affects the entire process group.
518 error("setsid failed: %.100s", strerror(errno));
522 * Redirect stdin. We close the parent side of the socket
523 * pair, and make the child side the standard input.
526 if (dup2(pin[0], 0) < 0)
527 perror("dup2 stdin");
530 /* Redirect stdout. */
532 if (dup2(pout[1], 1) < 0)
533 perror("dup2 stdout");
536 /* Redirect stderr. */
538 if (dup2(perr[1], 2) < 0)
539 perror("dup2 stderr");
543 * Redirect stdin, stdout, and stderr. Stdin and stdout will
544 * use the same socket, as some programs (particularly rdist)
545 * seem to depend on it.
549 if (dup2(inout[0], 0) < 0) /* stdin */
550 perror("dup2 stdin");
551 if (dup2(inout[0], 1) < 0) /* stdout (same as stdin) */
552 perror("dup2 stdout");
554 if (dup2(err[0], 2) < 0) /* stderr */
555 perror("dup2 stderr");
561 cray_init_job(s->pw); /* set up cray jid and tmpdir */
564 /* Do processing for the child (exec command etc). */
565 do_child(s, command);
572 signal(WJSIGNAL, cray_job_termination_handler);
576 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
580 /* Set interactive/non-interactive mode. */
581 packet_set_interactive(s->display != NULL);
584 * Clear loginmsg, since it's the child's responsibility to display
585 * it to the user, otherwise multiple sessions may accumulate
586 * multiple copies of the login messages.
588 buffer_clear(&loginmsg);
591 /* We are the parent. Close the child sides of the pipes. */
597 if (s->is_subsystem) {
601 session_set_fds(s, pin[1], pout[0], perr[0], 0);
603 /* Enter the interactive session. */
604 server_loop(pid, pin[1], pout[0], perr[0]);
605 /* server_loop has closed pin[1], pout[0], and perr[0]. */
608 /* We are the parent. Close the child sides of the socket pairs. */
613 * Enter the interactive session. Note: server_loop must be able to
614 * handle the case that fdin and fdout are the same.
617 session_set_fds(s, inout[1], inout[1],
618 s->is_subsystem ? -1 : err[1], 0);
622 server_loop(pid, inout[1], inout[1], err[1]);
623 /* server_loop has closed inout[1] and err[1]. */
630 * This is called to fork and execute a command when we have a tty. This
631 * will call do_child from the child, and server_loop from the parent after
632 * setting up file descriptors, controlling tty, updating wtmp, utmp,
633 * lastlog, and other such operations.
636 do_exec_pty(Session *s, const char *command)
638 int fdout, ptyfd, ttyfd, ptymaster;
642 fatal("do_exec_pty: no session");
647 * Create another descriptor of the pty master side for use as the
648 * standard input. We could use the original descriptor, but this
649 * simplifies code in server_loop. The descriptor is bidirectional.
650 * Do this before forking (and cleanup in the child) so as to
651 * detect and gracefully fail out-of-fd conditions.
653 if ((fdout = dup(ptyfd)) < 0) {
654 error("%s: dup #1: %s", __func__, strerror(errno));
659 /* we keep a reference to the pty master */
660 if ((ptymaster = dup(ptyfd)) < 0) {
661 error("%s: dup #2: %s", __func__, strerror(errno));
668 /* Fork the child. */
669 switch ((pid = fork())) {
671 error("%s: fork: %.100s", __func__, strerror(errno));
683 /* Child. Reinitialize the log because the pid has changed. */
684 log_init(__progname, options.log_level,
685 options.log_facility, log_stderr);
686 /* Close the master side of the pseudo tty. */
689 /* Make the pseudo tty our controlling tty. */
690 pty_make_controlling_tty(&ttyfd, s->tty);
692 /* Redirect stdin/stdout/stderr from the pseudo tty. */
693 if (dup2(ttyfd, 0) < 0)
694 error("dup2 stdin: %s", strerror(errno));
695 if (dup2(ttyfd, 1) < 0)
696 error("dup2 stdout: %s", strerror(errno));
697 if (dup2(ttyfd, 2) < 0)
698 error("dup2 stderr: %s", strerror(errno));
700 /* Close the extra descriptor for the pseudo tty. */
703 /* record login, etc. similar to login(1) */
705 if (!(options.use_login && command == NULL)) {
707 cray_init_job(s->pw); /* set up cray jid and tmpdir */
709 do_login(s, command);
711 # ifdef LOGIN_NEEDS_UTMPX
717 * Do common processing for the child, such as execing
720 do_child(s, command);
727 signal(WJSIGNAL, cray_job_termination_handler);
731 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
736 /* Parent. Close the slave side of the pseudo tty. */
739 /* Enter interactive session. */
740 s->ptymaster = ptymaster;
741 packet_set_interactive(1);
743 session_set_fds(s, ptyfd, fdout, -1, 1);
745 server_loop(pid, ptyfd, fdout, -1);
746 /* server_loop _has_ closed ptyfd and fdout. */
751 #ifdef LOGIN_NEEDS_UTMPX
753 do_pre_login(Session *s)
756 struct sockaddr_storage from;
757 pid_t pid = getpid();
760 * Get IP address of client. If the connection is not a socket, let
761 * the address be 0.0.0.0.
763 memset(&from, 0, sizeof(from));
764 fromlen = sizeof(from);
765 if (packet_connection_is_on_socket()) {
766 if (getpeername(packet_get_connection_in(),
767 (struct sockaddr *)&from, &fromlen) < 0) {
768 debug("getpeername: %.100s", strerror(errno));
773 record_utmp_only(pid, s->tty, s->pw->pw_name,
774 get_remote_name_or_ip(utmp_len, options.use_dns),
775 (struct sockaddr *)&from, fromlen);
780 * This is called to fork and execute a command. If another command is
781 * to be forced, execute that instead.
784 do_exec(Session *s, const char *command)
788 if (options.adm_forced_command) {
789 original_command = command;
790 command = options.adm_forced_command;
791 if (IS_INTERNAL_SFTP(command))
792 s->is_subsystem = SUBSYSTEM_INT_SFTP;
793 else if (s->is_subsystem)
794 s->is_subsystem = SUBSYSTEM_EXT;
795 debug("Forced command (config) '%.900s'", command);
796 } else if (forced_command) {
797 original_command = command;
798 command = forced_command;
799 if (IS_INTERNAL_SFTP(command))
800 s->is_subsystem = SUBSYSTEM_INT_SFTP;
801 else if (s->is_subsystem)
802 s->is_subsystem = SUBSYSTEM_EXT;
803 debug("Forced command (key option) '%.900s'", command);
806 #ifdef SSH_AUDIT_EVENTS
808 PRIVSEP(audit_run_command(command));
809 else if (s->ttyfd == -1) {
810 char *shell = s->pw->pw_shell;
812 if (shell[0] == '\0') /* empty shell means /bin/sh */
814 PRIVSEP(audit_run_command(shell));
818 ret = do_exec_pty(s, command);
820 ret = do_exec_no_pty(s, command);
822 original_command = NULL;
825 * Clear loginmsg: it's the child's responsibility to display
826 * it to the user, otherwise multiple sessions may accumulate
827 * multiple copies of the login messages.
829 buffer_clear(&loginmsg);
834 /* administrative, login(1)-like work */
836 do_login(Session *s, const char *command)
839 struct sockaddr_storage from;
840 struct passwd * pw = s->pw;
841 pid_t pid = getpid();
844 * Get IP address of client. If the connection is not a socket, let
845 * the address be 0.0.0.0.
847 memset(&from, 0, sizeof(from));
848 fromlen = sizeof(from);
849 if (packet_connection_is_on_socket()) {
850 if (getpeername(packet_get_connection_in(),
851 (struct sockaddr *) & from, &fromlen) < 0) {
852 debug("getpeername: %.100s", strerror(errno));
857 /* Record that there was a login on that tty from the remote host. */
859 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
860 get_remote_name_or_ip(utmp_len,
862 (struct sockaddr *)&from, fromlen);
866 * If password change is needed, do it now.
867 * This needs to occur before the ~/.hushlogin check.
869 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
872 s->authctxt->force_pwchange = 0;
873 /* XXX - signal [net] parent to enable forwardings */
877 if (check_quietlogin(s, command))
886 * Display the message of the day.
893 #ifdef HAVE_LOGIN_CAP
897 #ifdef HAVE_LOGIN_CAP
898 fname = login_getcapstr(lc, "copyright", NULL, NULL);
899 if (fname != NULL && (f = fopen(fname, "r")) != NULL) {
900 while (fgets(buf, sizeof(buf), f) != NULL)
904 #endif /* HAVE_LOGIN_CAP */
905 (void)printf("%s\n\t%s %s\n",
906 "Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994",
907 "The Regents of the University of California. ",
908 "All rights reserved.");
912 if (options.print_motd) {
913 #ifdef HAVE_LOGIN_CAP
914 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
917 f = fopen("/etc/motd", "r");
920 while (fgets(buf, sizeof(buf), f))
929 * Check for quiet login, either .hushlogin or command given.
932 check_quietlogin(Session *s, const char *command)
935 struct passwd *pw = s->pw;
938 /* Return 1 if .hushlogin exists or a command given. */
941 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
942 #ifdef HAVE_LOGIN_CAP
943 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
946 if (stat(buf, &st) >= 0)
953 * Sets the value of the given variable in the environment. If the variable
954 * already exists, its value is overridden.
957 child_set_env(char ***envp, u_int *envsizep, const char *name,
965 * If we're passed an uninitialized list, allocate a single null
966 * entry before continuing.
968 if (*envp == NULL && *envsizep == 0) {
969 *envp = xmalloc(sizeof(char *));
975 * Find the slot where the value should be stored. If the variable
976 * already exists, we reuse the slot; otherwise we append a new slot
977 * at the end of the array, expanding if necessary.
980 namelen = strlen(name);
981 for (i = 0; env[i]; i++)
982 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
985 /* Reuse the slot. */
988 /* New variable. Expand if necessary. */
990 if (i >= envsize - 1) {
992 fatal("child_set_env: too many env vars");
994 env = (*envp) = xrealloc(env, envsize, sizeof(char *));
997 /* Need to set the NULL pointer at end of array beyond the new slot. */
1001 /* Allocate space and format the variable in the appropriate slot. */
1002 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
1003 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
1007 * Reads environment variables from the given file and adds/overrides them
1008 * into the environment. If the file does not exist, this does nothing.
1009 * Otherwise, it must consist of empty lines, comments (line starts with '#')
1010 * and assignments of the form name=value. No other forms are allowed.
1013 read_environment_file(char ***env, u_int *envsize,
1014 const char *filename)
1021 f = fopen(filename, "r");
1025 while (fgets(buf, sizeof(buf), f)) {
1026 if (++lineno > 1000)
1027 fatal("Too many lines in environment file %s", filename);
1028 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
1030 if (!*cp || *cp == '#' || *cp == '\n')
1033 cp[strcspn(cp, "\n")] = '\0';
1035 value = strchr(cp, '=');
1036 if (value == NULL) {
1037 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
1042 * Replace the equals sign by nul, and advance value to
1047 child_set_env(env, envsize, cp, value);
1052 #ifdef HAVE_ETC_DEFAULT_LOGIN
1054 * Return named variable from specified environment, or NULL if not present.
1057 child_get_env(char **env, const char *name)
1063 for (i=0; env[i] != NULL; i++)
1064 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
1065 return(env[i] + len + 1);
1070 * Read /etc/default/login.
1071 * We pick up the PATH (or SUPATH for root) and UMASK.
1074 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
1076 char **tmpenv = NULL, *var;
1077 u_int i, tmpenvsize = 0;
1081 * We don't want to copy the whole file to the child's environment,
1082 * so we use a temporary environment and copy the variables we're
1085 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
1091 var = child_get_env(tmpenv, "SUPATH");
1093 var = child_get_env(tmpenv, "PATH");
1095 child_set_env(env, envsize, "PATH", var);
1097 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
1098 if (sscanf(var, "%5lo", &mask) == 1)
1099 umask((mode_t)mask);
1101 for (i = 0; tmpenv[i] != NULL; i++)
1105 #endif /* HAVE_ETC_DEFAULT_LOGIN */
1108 copy_environment(char **source, char ***env, u_int *envsize)
1110 char *var_name, *var_val;
1116 for(i = 0; source[i] != NULL; i++) {
1117 var_name = xstrdup(source[i]);
1118 if ((var_val = strstr(var_name, "=")) == NULL) {
1124 debug3("Copy environment: %s=%s", var_name, var_val);
1125 child_set_env(env, envsize, var_name, var_val);
1132 do_setup_env(Session *s, const char *shell)
1137 struct passwd *pw = s->pw;
1138 #ifndef HAVE_LOGIN_CAP
1141 extern char **environ;
1145 /* Initialize the environment. */
1147 env = xcalloc(envsize, sizeof(char *));
1152 * The Windows environment contains some setting which are
1153 * important for a running system. They must not be dropped.
1158 p = fetch_windows_environment();
1159 copy_environment(p, &env, &envsize);
1160 free_windows_environment(p);
1165 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1168 /* Allow any GSSAPI methods that we've used to alter
1169 * the childs environment as they see fit
1171 ssh_gssapi_do_child(&env, &envsize);
1174 if (!options.use_login) {
1175 /* Set basic environment. */
1176 for (i = 0; i < s->num_env; i++)
1177 child_set_env(&env, &envsize, s->env[i].name,
1180 child_set_env(&env, &envsize, "USER", pw->pw_name);
1181 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1183 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1185 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1186 snprintf(buf, sizeof buf, "%.200s/%.50s",
1187 _PATH_MAILDIR, pw->pw_name);
1188 child_set_env(&env, &envsize, "MAIL", buf);
1189 #ifdef HAVE_LOGIN_CAP
1190 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1191 child_set_env(&env, &envsize, "TERM", "su");
1193 environ = xmalloc(sizeof(char *));
1195 (void) setusercontext(lc, pw, pw->pw_uid,
1196 LOGIN_SETENV|LOGIN_SETPATH);
1197 copy_environment(environ, &env, &envsize);
1198 for (var = environ; *var != NULL; ++var)
1202 #else /* HAVE_LOGIN_CAP */
1203 # ifndef HAVE_CYGWIN
1205 * There's no standard path on Windows. The path contains
1206 * important components pointing to the system directories,
1207 * needed for loading shared libraries. So the path better
1208 * remains intact here.
1210 # ifdef HAVE_ETC_DEFAULT_LOGIN
1211 read_etc_default_login(&env, &envsize, pw->pw_uid);
1212 path = child_get_env(env, "PATH");
1213 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1214 if (path == NULL || *path == '\0') {
1215 child_set_env(&env, &envsize, "PATH",
1216 s->pw->pw_uid == 0 ?
1217 SUPERUSER_PATH : _PATH_STDPATH);
1219 # endif /* HAVE_CYGWIN */
1220 #endif /* HAVE_LOGIN_CAP */
1222 /* Normal systems set SHELL by default. */
1223 child_set_env(&env, &envsize, "SHELL", shell);
1226 /* Set custom environment options from RSA authentication. */
1227 if (!options.use_login) {
1228 while (custom_environment) {
1229 struct envstring *ce = custom_environment;
1232 for (i = 0; str[i] != '=' && str[i]; i++)
1234 if (str[i] == '=') {
1236 child_set_env(&env, &envsize, str, str + i + 1);
1238 custom_environment = ce->next;
1244 /* SSH_CLIENT deprecated */
1245 snprintf(buf, sizeof buf, "%.50s %d %d",
1246 get_remote_ipaddr(), get_remote_port(), get_local_port());
1247 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1249 laddr = get_local_ipaddr(packet_get_connection_in());
1250 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1251 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1253 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1256 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1258 child_set_env(&env, &envsize, "TERM", s->term);
1260 child_set_env(&env, &envsize, "DISPLAY", s->display);
1261 if (original_command)
1262 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1266 if (cray_tmpdir[0] != '\0')
1267 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1268 #endif /* _UNICOS */
1271 * Since we clear KRB5CCNAME at startup, if it's set now then it
1272 * must have been set by a native authentication method (eg AIX or
1273 * SIA), so copy it to the child.
1278 if ((cp = getenv("KRB5CCNAME")) != NULL)
1279 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1286 if ((cp = getenv("AUTHSTATE")) != NULL)
1287 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1288 read_environment_file(&env, &envsize, "/etc/environment");
1292 if (s->authctxt->krb5_ccname)
1293 child_set_env(&env, &envsize, "KRB5CCNAME",
1294 s->authctxt->krb5_ccname);
1298 * Pull in any environment variables that may have
1301 if (options.use_pam) {
1304 p = fetch_pam_child_environment();
1305 copy_environment(p, &env, &envsize);
1306 free_pam_environment(p);
1308 p = fetch_pam_environment();
1309 copy_environment(p, &env, &envsize);
1310 free_pam_environment(p);
1312 #endif /* USE_PAM */
1314 if (auth_sock_name != NULL)
1315 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1318 /* read $HOME/.ssh/environment. */
1319 if (options.permit_user_env && !options.use_login) {
1320 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1321 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1322 read_environment_file(&env, &envsize, buf);
1325 /* dump the environment */
1326 fprintf(stderr, "Environment:\n");
1327 for (i = 0; env[i]; i++)
1328 fprintf(stderr, " %.200s\n", env[i]);
1334 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1335 * first in this order).
1338 do_rc_files(Session *s, const char *shell)
1346 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1348 /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
1349 if (!s->is_subsystem && options.adm_forced_command == NULL &&
1350 !no_user_rc && stat(_PATH_SSH_USER_RC, &st) >= 0) {
1351 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1352 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1354 fprintf(stderr, "Running %s\n", cmd);
1355 f = popen(cmd, "w");
1358 fprintf(f, "%s %s\n", s->auth_proto,
1362 fprintf(stderr, "Could not run %s\n",
1364 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1366 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1367 _PATH_SSH_SYSTEM_RC);
1368 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1371 fprintf(f, "%s %s\n", s->auth_proto,
1375 fprintf(stderr, "Could not run %s\n",
1376 _PATH_SSH_SYSTEM_RC);
1377 } else if (do_xauth && options.xauth_location != NULL) {
1378 /* Add authority data to .Xauthority if appropriate. */
1381 "Running %.500s remove %.100s\n",
1382 options.xauth_location, s->auth_display);
1384 "%.500s add %.100s %.100s %.100s\n",
1385 options.xauth_location, s->auth_display,
1386 s->auth_proto, s->auth_data);
1388 snprintf(cmd, sizeof cmd, "%s -q -",
1389 options.xauth_location);
1390 f = popen(cmd, "w");
1392 fprintf(f, "remove %s\n",
1394 fprintf(f, "add %s %s %s\n",
1395 s->auth_display, s->auth_proto,
1399 fprintf(stderr, "Could not run %s\n",
1406 do_nologin(struct passwd *pw)
1411 #ifdef HAVE_LOGIN_CAP
1412 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1413 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1414 _PATH_NOLOGIN), "r");
1417 f = fopen(_PATH_NOLOGIN, "r");
1420 /* /etc/nologin exists. Print its contents and exit. */
1421 logit("User %.100s not allowed because %s exists",
1422 pw->pw_name, _PATH_NOLOGIN);
1423 while (fgets(buf, sizeof(buf), f))
1432 * Chroot into a directory after checking it for safety: all path components
1433 * must be root-owned directories with strict permissions.
1436 safely_chroot(const char *path, uid_t uid)
1439 char component[MAXPATHLEN];
1443 fatal("chroot path does not begin at root");
1444 if (strlen(path) >= sizeof(component))
1445 fatal("chroot path too long");
1448 * Descend the path, checking that each component is a
1449 * root-owned directory with strict permissions.
1451 for (cp = path; cp != NULL;) {
1452 if ((cp = strchr(cp, '/')) == NULL)
1453 strlcpy(component, path, sizeof(component));
1456 memcpy(component, path, cp - path);
1457 component[cp - path] = '\0';
1460 debug3("%s: checking '%s'", __func__, component);
1462 if (stat(component, &st) != 0)
1463 fatal("%s: stat(\"%s\"): %s", __func__,
1464 component, strerror(errno));
1465 if (st.st_uid != 0 || (st.st_mode & 022) != 0)
1466 fatal("bad ownership or modes for chroot "
1467 "directory %s\"%s\"",
1468 cp == NULL ? "" : "component ", component);
1469 if (!S_ISDIR(st.st_mode))
1470 fatal("chroot path %s\"%s\" is not a directory",
1471 cp == NULL ? "" : "component ", component);
1475 if (chdir(path) == -1)
1476 fatal("Unable to chdir to chroot path \"%s\": "
1477 "%s", path, strerror(errno));
1478 if (chroot(path) == -1)
1479 fatal("chroot(\"%s\"): %s", path, strerror(errno));
1480 if (chdir("/") == -1)
1481 fatal("%s: chdir(/) after chroot: %s",
1482 __func__, strerror(errno));
1483 verbose("Changed root directory to \"%s\"", path);
1486 /* Set login name, uid, gid, and groups. */
1488 do_setusercontext(struct passwd *pw)
1490 char *chroot_path, *tmp;
1493 /* Cache selinux status for later use */
1494 (void)ssh_selinux_enabled();
1498 if (getuid() == 0 || geteuid() == 0)
1499 #endif /* HAVE_CYGWIN */
1502 #ifdef HAVE_SETPCRED
1503 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1504 fatal("Failed to set process credentials");
1505 #endif /* HAVE_SETPCRED */
1506 #ifdef HAVE_LOGIN_CAP
1511 if (options.use_pam) {
1512 do_pam_setcred(use_privsep);
1514 # endif /* USE_PAM */
1515 if (setusercontext(lc, pw, pw->pw_uid,
1516 (LOGIN_SETALL & ~(LOGIN_SETENV|LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1517 perror("unable to set user context");
1521 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1522 /* Sets login uid for accounting */
1523 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1524 error("setluid: %s", strerror(errno));
1525 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1527 if (setlogin(pw->pw_name) < 0)
1528 error("setlogin failed: %s", strerror(errno));
1529 if (setgid(pw->pw_gid) < 0) {
1533 /* Initialize the group list. */
1534 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1535 perror("initgroups");
1541 * PAM credentials may take the form of supplementary groups.
1542 * These will have been wiped by the above initgroups() call.
1543 * Reestablish them here.
1545 if (options.use_pam) {
1546 do_pam_setcred(use_privsep);
1548 # endif /* USE_PAM */
1549 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1550 irix_setusercontext(pw);
1551 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1556 if (set_id(pw->pw_name) != 0) {
1559 # endif /* USE_LIBIAF */
1562 if (options.chroot_directory != NULL &&
1563 strcasecmp(options.chroot_directory, "none") != 0) {
1564 tmp = tilde_expand_filename(options.chroot_directory,
1566 chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1567 "u", pw->pw_name, (char *)NULL);
1568 safely_chroot(chroot_path, pw->pw_uid);
1573 #ifdef HAVE_LOGIN_CAP
1574 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
1575 perror("unable to set user context (setuser)");
1579 /* Permanently switch to the desired uid. */
1580 permanently_set_uid(pw);
1587 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1588 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1591 ssh_selinux_setup_exec_context(pw->pw_name);
1596 do_pwchange(Session *s)
1599 fprintf(stderr, "WARNING: Your password has expired.\n");
1600 if (s->ttyfd != -1) {
1602 "You must change your password now and login again!\n");
1603 #ifdef PASSWD_NEEDS_USERNAME
1604 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1607 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1612 "Password change required but no TTY available.\n");
1618 launch_login(struct passwd *pw, const char *hostname)
1620 /* Launch login(1). */
1622 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1623 #ifdef xxxLOGIN_NEEDS_TERM
1624 (s->term ? s->term : "unknown"),
1625 #endif /* LOGIN_NEEDS_TERM */
1626 #ifdef LOGIN_NO_ENDOPT
1627 "-p", "-f", pw->pw_name, (char *)NULL);
1629 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1632 /* Login couldn't be executed, die. */
1639 child_close_fds(void)
1643 if (packet_get_connection_in() == packet_get_connection_out())
1644 close(packet_get_connection_in());
1646 close(packet_get_connection_in());
1647 close(packet_get_connection_out());
1650 * Close all descriptors related to channels. They will still remain
1651 * open in the parent.
1653 /* XXX better use close-on-exec? -markus */
1654 channel_close_all();
1657 * Close any extra file descriptors. Note that there may still be
1658 * descriptors left by system functions. They will be closed later.
1663 * Close any extra open file descriptors so that we don't have them
1664 * hanging around in clients. Note that we want to do this after
1665 * initgroups, because at least on Solaris 2.3 it leaves file
1668 for (i = 3; i < 64; i++)
1673 * Performs common processing for the child, such as setting up the
1674 * environment, closing extra file descriptors, setting the user and group
1675 * ids, and executing the command or shell.
1679 do_child(Session *s, const char *command)
1681 extern char **environ;
1683 char *argv[ARGV_MAX];
1684 const char *shell, *shell0, *hostname = NULL;
1685 struct passwd *pw = s->pw;
1688 /* remove hostkey from the child's memory */
1689 destroy_sensitive_data();
1691 /* Force a password change */
1692 if (s->authctxt->force_pwchange) {
1693 do_setusercontext(pw);
1699 /* login(1) is only called if we execute the login shell */
1700 if (options.use_login && command != NULL)
1701 options.use_login = 0;
1704 cray_setup(pw->pw_uid, pw->pw_name, command);
1705 #endif /* _UNICOS */
1708 * Login(1) does this as well, and it needs uid 0 for the "-h"
1709 * switch, so we let login(1) to this for us.
1711 if (!options.use_login) {
1713 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1714 if (!check_quietlogin(s, command))
1716 #else /* HAVE_OSF_SIA */
1717 /* When PAM is enabled we rely on it to do the nologin check */
1718 if (!options.use_pam)
1720 do_setusercontext(pw);
1722 * PAM session modules in do_setusercontext may have
1723 * generated messages, so if this in an interactive
1724 * login then display them too.
1726 if (!check_quietlogin(s, command))
1728 #endif /* HAVE_OSF_SIA */
1732 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1733 debug3("PAM session not opened, exiting");
1740 * Get the shell from the password data. An empty shell field is
1741 * legal, and means /bin/sh.
1743 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1746 * Make sure $SHELL points to the shell from the password file,
1747 * even if shell is overridden from login.conf
1749 env = do_setup_env(s, shell);
1751 #ifdef HAVE_LOGIN_CAP
1752 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1755 /* we have to stash the hostname before we close our socket. */
1756 if (options.use_login)
1757 hostname = get_remote_name_or_ip(utmp_len,
1760 * Close the connection descriptors; note that this is the child, and
1761 * the server will still have the socket open, and it is important
1762 * that we do not shutdown it. Note that the descriptors cannot be
1763 * closed before building the environment, as we call
1764 * get_remote_ipaddr there.
1769 * Must take new environment into use so that .ssh/rc,
1770 * /etc/ssh/sshrc and xauth are run in the proper environment.
1774 #if defined(KRB5) && defined(USE_AFS)
1776 * At this point, we check to see if AFS is active and if we have
1777 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1778 * if we can (and need to) extend the ticket into an AFS token. If
1779 * we don't do this, we run into potential problems if the user's
1780 * home directory is in AFS and it's not world-readable.
1783 if (options.kerberos_get_afs_token && k_hasafs() &&
1784 (s->authctxt->krb5_ctx != NULL)) {
1787 debug("Getting AFS token");
1791 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1792 krb5_afslog(s->authctxt->krb5_ctx,
1793 s->authctxt->krb5_fwd_ccache, cell, NULL);
1795 krb5_afslog_home(s->authctxt->krb5_ctx,
1796 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1800 /* Change current directory to the user's home directory. */
1801 if (chdir(pw->pw_dir) < 0) {
1802 /* Suppress missing homedir warning for chroot case */
1803 #ifdef HAVE_LOGIN_CAP
1804 r = login_getcapbool(lc, "requirehome", 0);
1806 if (r || options.chroot_directory == NULL)
1807 fprintf(stderr, "Could not chdir to home "
1808 "directory %s: %s\n", pw->pw_dir,
1814 closefrom(STDERR_FILENO + 1);
1816 if (!options.use_login)
1817 do_rc_files(s, shell);
1819 /* restore SIGPIPE for child */
1820 signal(SIGPIPE, SIG_DFL);
1822 if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1823 extern int optind, optreset;
1827 setproctitle("%s@internal-sftp-server", s->pw->pw_name);
1828 args = xstrdup(command ? command : "sftp-server");
1829 for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1830 if (i < ARGV_MAX - 1)
1833 optind = optreset = 1;
1834 __progname = argv[0];
1835 exit(sftp_server_main(i, argv, s->pw));
1838 if (options.use_login) {
1839 launch_login(pw, hostname);
1843 /* Get the last component of the shell name. */
1844 if ((shell0 = strrchr(shell, '/')) != NULL)
1850 * If we have no command, execute the shell. In this case, the shell
1851 * name to be passed in argv[0] is preceded by '-' to indicate that
1852 * this is a login shell.
1857 /* Start the shell. Set initial character to '-'. */
1860 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1861 >= sizeof(argv0) - 1) {
1867 /* Execute the shell. */
1870 execve(shell, argv, env);
1872 /* Executing the shell failed. */
1877 * Execute the command using the user's shell. This uses the -c
1878 * option to execute the command.
1880 argv[0] = (char *) shell0;
1882 argv[2] = (char *) command;
1884 execve(shell, argv, env);
1890 session_unused(int id)
1892 debug3("%s: session id %d unused", __func__, id);
1893 if (id >= options.max_sessions ||
1894 id >= sessions_nalloc) {
1895 fatal("%s: insane session id %d (max %d nalloc %d)",
1896 __func__, id, options.max_sessions, sessions_nalloc);
1898 bzero(&sessions[id], sizeof(*sessions));
1899 sessions[id].self = id;
1900 sessions[id].used = 0;
1901 sessions[id].chanid = -1;
1902 sessions[id].ptyfd = -1;
1903 sessions[id].ttyfd = -1;
1904 sessions[id].ptymaster = -1;
1905 sessions[id].x11_chanids = NULL;
1906 sessions[id].next_unused = sessions_first_unused;
1907 sessions_first_unused = id;
1915 if (sessions_first_unused == -1) {
1916 if (sessions_nalloc >= options.max_sessions)
1918 debug2("%s: allocate (allocated %d max %d)",
1919 __func__, sessions_nalloc, options.max_sessions);
1920 tmp = xrealloc(sessions, sessions_nalloc + 1,
1923 error("%s: cannot allocate %d sessions",
1924 __func__, sessions_nalloc + 1);
1928 session_unused(sessions_nalloc++);
1931 if (sessions_first_unused >= sessions_nalloc ||
1932 sessions_first_unused < 0) {
1933 fatal("%s: insane first_unused %d max %d nalloc %d",
1934 __func__, sessions_first_unused, options.max_sessions,
1938 s = &sessions[sessions_first_unused];
1940 fatal("%s: session %d already used",
1941 __func__, sessions_first_unused);
1943 sessions_first_unused = s->next_unused;
1945 s->next_unused = -1;
1946 debug("session_new: session %d", s->self);
1955 for (i = 0; i < sessions_nalloc; i++) {
1956 Session *s = &sessions[i];
1958 debug("dump: used %d next_unused %d session %d %p "
1959 "channel %d pid %ld",
1970 session_open(Authctxt *authctxt, int chanid)
1972 Session *s = session_new();
1973 debug("session_open: channel %d", chanid);
1975 error("no more sessions");
1978 s->authctxt = authctxt;
1979 s->pw = authctxt->pw;
1980 if (s->pw == NULL || !authctxt->valid)
1981 fatal("no user for session %d", s->self);
1982 debug("session_open: session %d: link with channel %d", s->self, chanid);
1988 session_by_tty(char *tty)
1991 for (i = 0; i < sessions_nalloc; i++) {
1992 Session *s = &sessions[i];
1993 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1994 debug("session_by_tty: session %d tty %s", i, tty);
1998 debug("session_by_tty: unknown tty %.100s", tty);
2004 session_by_channel(int id)
2007 for (i = 0; i < sessions_nalloc; i++) {
2008 Session *s = &sessions[i];
2009 if (s->used && s->chanid == id) {
2010 debug("session_by_channel: session %d channel %d",
2015 debug("session_by_channel: unknown channel %d", id);
2021 session_by_x11_channel(int id)
2025 for (i = 0; i < sessions_nalloc; i++) {
2026 Session *s = &sessions[i];
2028 if (s->x11_chanids == NULL || !s->used)
2030 for (j = 0; s->x11_chanids[j] != -1; j++) {
2031 if (s->x11_chanids[j] == id) {
2032 debug("session_by_x11_channel: session %d "
2033 "channel %d", s->self, id);
2038 debug("session_by_x11_channel: unknown channel %d", id);
2044 session_by_pid(pid_t pid)
2047 debug("session_by_pid: pid %ld", (long)pid);
2048 for (i = 0; i < sessions_nalloc; i++) {
2049 Session *s = &sessions[i];
2050 if (s->used && s->pid == pid)
2053 error("session_by_pid: unknown pid %ld", (long)pid);
2059 session_window_change_req(Session *s)
2061 s->col = packet_get_int();
2062 s->row = packet_get_int();
2063 s->xpixel = packet_get_int();
2064 s->ypixel = packet_get_int();
2066 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
2071 session_pty_req(Session *s)
2077 debug("Allocating a pty not permitted for this authentication.");
2080 if (s->ttyfd != -1) {
2081 packet_disconnect("Protocol error: you already have a pty.");
2085 s->term = packet_get_string(&len);
2088 s->col = packet_get_int();
2089 s->row = packet_get_int();
2091 s->row = packet_get_int();
2092 s->col = packet_get_int();
2094 s->xpixel = packet_get_int();
2095 s->ypixel = packet_get_int();
2097 if (strcmp(s->term, "") == 0) {
2102 /* Allocate a pty and open it. */
2103 debug("Allocating pty.");
2104 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
2111 error("session_pty_req: session %d alloc failed", s->self);
2114 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
2116 /* for SSH1 the tty modes length is not given */
2118 n_bytes = packet_remaining();
2119 tty_parse_modes(s->ttyfd, &n_bytes);
2122 pty_setowner(s->pw, s->tty);
2124 /* Set window size from the packet. */
2125 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
2128 session_proctitle(s);
2133 session_subsystem_req(Session *s)
2138 char *prog, *cmd, *subsys = packet_get_string(&len);
2142 logit("subsystem request for %.100s", subsys);
2144 for (i = 0; i < options.num_subsystems; i++) {
2145 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
2146 prog = options.subsystem_command[i];
2147 cmd = options.subsystem_args[i];
2148 if (!strcmp(INTERNAL_SFTP_NAME, prog)) {
2149 s->is_subsystem = SUBSYSTEM_INT_SFTP;
2150 } else if (stat(prog, &st) < 0) {
2151 error("subsystem: cannot stat %s: %s", prog,
2155 s->is_subsystem = SUBSYSTEM_EXT;
2157 debug("subsystem: exec() %s", cmd);
2158 success = do_exec(s, cmd) == 0;
2164 logit("subsystem request for %.100s failed, subsystem not found",
2172 session_x11_req(Session *s)
2176 if (s->auth_proto != NULL || s->auth_data != NULL) {
2177 error("session_x11_req: session %d: "
2178 "x11 forwarding already active", s->self);
2181 s->single_connection = packet_get_char();
2182 s->auth_proto = packet_get_string(NULL);
2183 s->auth_data = packet_get_string(NULL);
2184 s->screen = packet_get_int();
2187 success = session_setup_x11fwd(s);
2189 xfree(s->auth_proto);
2190 xfree(s->auth_data);
2191 s->auth_proto = NULL;
2192 s->auth_data = NULL;
2198 session_shell_req(Session *s)
2201 return do_exec(s, NULL) == 0;
2205 session_exec_req(Session *s)
2209 char *command = packet_get_string(&len);
2211 success = do_exec(s, command) == 0;
2217 session_break_req(Session *s)
2220 packet_get_int(); /* ignored */
2223 if (s->ttyfd == -1 || tcsendbreak(s->ttyfd, 0) < 0)
2229 session_env_req(Session *s)
2232 u_int name_len, val_len, i;
2234 name = packet_get_string(&name_len);
2235 val = packet_get_string(&val_len);
2238 /* Don't set too many environment variables */
2239 if (s->num_env > 128) {
2240 debug2("Ignoring env request %s: too many env vars", name);
2244 for (i = 0; i < options.num_accept_env; i++) {
2245 if (match_pattern(name, options.accept_env[i])) {
2246 debug2("Setting env %d: %s=%s", s->num_env, name, val);
2247 s->env = xrealloc(s->env, s->num_env + 1,
2249 s->env[s->num_env].name = name;
2250 s->env[s->num_env].val = val;
2255 debug2("Ignoring env request %s: disallowed name", name);
2264 session_auth_agent_req(Session *s)
2266 static int called = 0;
2268 if (no_agent_forwarding_flag || !options.allow_agent_forwarding) {
2269 debug("session_auth_agent_req: no_agent_forwarding_flag");
2276 return auth_input_request_forwarding(s->pw);
2281 session_input_channel_req(Channel *c, const char *rtype)
2286 if ((s = session_by_channel(c->self)) == NULL) {
2287 logit("session_input_channel_req: no session %d req %.100s",
2291 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2294 * a session is in LARVAL state until a shell, a command
2295 * or a subsystem is executed
2297 if (c->type == SSH_CHANNEL_LARVAL) {
2298 if (strcmp(rtype, "shell") == 0) {
2299 success = session_shell_req(s);
2300 } else if (strcmp(rtype, "exec") == 0) {
2301 success = session_exec_req(s);
2302 } else if (strcmp(rtype, "pty-req") == 0) {
2303 success = session_pty_req(s);
2304 } else if (strcmp(rtype, "x11-req") == 0) {
2305 success = session_x11_req(s);
2306 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2307 success = session_auth_agent_req(s);
2308 } else if (strcmp(rtype, "subsystem") == 0) {
2309 success = session_subsystem_req(s);
2310 } else if (strcmp(rtype, "env") == 0) {
2311 success = session_env_req(s);
2314 if (strcmp(rtype, "window-change") == 0) {
2315 success = session_window_change_req(s);
2316 } else if (strcmp(rtype, "break") == 0) {
2317 success = session_break_req(s);
2324 session_set_fds(Session *s, int fdin, int fdout, int fderr, int is_tty)
2327 fatal("session_set_fds: called for proto != 2.0");
2329 * now that have a child and a pipe to the child,
2330 * we can activate our channel and register the fd's
2332 if (s->chanid == -1)
2333 fatal("no channel for session %d", s->self);
2334 channel_set_fds(s->chanid,
2336 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2337 1, is_tty, CHAN_SES_WINDOW_DEFAULT);
2341 * Function to perform pty cleanup. Also called if we get aborted abnormally
2342 * (e.g., due to a dropped connection).
2345 session_pty_cleanup2(Session *s)
2348 error("session_pty_cleanup: no session");
2354 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2356 /* Record that the user has logged out. */
2358 record_logout(s->pid, s->tty, s->pw->pw_name);
2360 /* Release the pseudo-tty. */
2362 pty_release(s->tty);
2365 * Close the server side of the socket pairs. We must do this after
2366 * the pty cleanup, so that another process doesn't get this pty
2367 * while we're still cleaning up.
2369 if (s->ptymaster != -1 && close(s->ptymaster) < 0)
2370 error("close(s->ptymaster/%d): %s",
2371 s->ptymaster, strerror(errno));
2373 /* unlink pty from session */
2378 session_pty_cleanup(Session *s)
2380 PRIVSEP(session_pty_cleanup2(s));
2386 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2401 return "SIG@openssh.com";
2405 session_close_x11(int id)
2409 if ((c = channel_by_id(id)) == NULL) {
2410 debug("session_close_x11: x11 channel %d missing", id);
2412 /* Detach X11 listener */
2413 debug("session_close_x11: detach x11 channel %d", id);
2414 channel_cancel_cleanup(id);
2415 if (c->ostate != CHAN_OUTPUT_CLOSED)
2421 session_close_single_x11(int id, void *arg)
2426 debug3("session_close_single_x11: channel %d", id);
2427 channel_cancel_cleanup(id);
2428 if ((s = session_by_x11_channel(id)) == NULL)
2429 fatal("session_close_single_x11: no x11 channel %d", id);
2430 for (i = 0; s->x11_chanids[i] != -1; i++) {
2431 debug("session_close_single_x11: session %d: "
2432 "closing channel %d", s->self, s->x11_chanids[i]);
2434 * The channel "id" is already closing, but make sure we
2435 * close all of its siblings.
2437 if (s->x11_chanids[i] != id)
2438 session_close_x11(s->x11_chanids[i]);
2440 xfree(s->x11_chanids);
2441 s->x11_chanids = NULL;
2446 if (s->auth_proto) {
2447 xfree(s->auth_proto);
2448 s->auth_proto = NULL;
2451 xfree(s->auth_data);
2452 s->auth_data = NULL;
2454 if (s->auth_display) {
2455 xfree(s->auth_display);
2456 s->auth_display = NULL;
2461 session_exit_message(Session *s, int status)
2465 if ((c = channel_lookup(s->chanid)) == NULL)
2466 fatal("session_exit_message: session %d: no channel %d",
2467 s->self, s->chanid);
2468 debug("session_exit_message: session %d channel %d pid %ld",
2469 s->self, s->chanid, (long)s->pid);
2471 if (WIFEXITED(status)) {
2472 channel_request_start(s->chanid, "exit-status", 0);
2473 packet_put_int(WEXITSTATUS(status));
2475 } else if (WIFSIGNALED(status)) {
2476 channel_request_start(s->chanid, "exit-signal", 0);
2477 packet_put_cstring(sig2name(WTERMSIG(status)));
2479 packet_put_char(WCOREDUMP(status)? 1 : 0);
2480 #else /* WCOREDUMP */
2482 #endif /* WCOREDUMP */
2483 packet_put_cstring("");
2484 packet_put_cstring("");
2487 /* Some weird exit cause. Just exit. */
2488 packet_disconnect("wait returned status %04x.", status);
2491 /* disconnect channel */
2492 debug("session_exit_message: release channel %d", s->chanid);
2495 * Adjust cleanup callback attachment to send close messages when
2496 * the channel gets EOF. The session will be then be closed
2497 * by session_close_by_channel when the childs close their fds.
2499 channel_register_cleanup(c->self, session_close_by_channel, 1);
2502 * emulate a write failure with 'chan_write_failed', nobody will be
2503 * interested in data we write.
2504 * Note that we must not call 'chan_read_failed', since there could
2505 * be some more data waiting in the pipe.
2507 if (c->ostate != CHAN_OUTPUT_CLOSED)
2508 chan_write_failed(c);
2512 session_close(Session *s)
2516 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2518 session_pty_cleanup(s);
2524 xfree(s->x11_chanids);
2525 if (s->auth_display)
2526 xfree(s->auth_display);
2528 xfree(s->auth_data);
2530 xfree(s->auth_proto);
2531 if (s->env != NULL) {
2532 for (i = 0; i < s->num_env; i++) {
2533 xfree(s->env[i].name);
2534 xfree(s->env[i].val);
2538 session_proctitle(s);
2539 session_unused(s->self);
2543 session_close_by_pid(pid_t pid, int status)
2545 Session *s = session_by_pid(pid);
2547 debug("session_close_by_pid: no session for pid %ld",
2551 if (s->chanid != -1)
2552 session_exit_message(s, status);
2554 session_pty_cleanup(s);
2559 * this is called when a channel dies before
2560 * the session 'child' itself dies
2563 session_close_by_channel(int id, void *arg)
2565 Session *s = session_by_channel(id);
2569 debug("session_close_by_channel: no session for id %d", id);
2572 debug("session_close_by_channel: channel %d child %ld",
2575 debug("session_close_by_channel: channel %d: has child", id);
2577 * delay detach of session, but release pty, since
2578 * the fd's to the child are already closed
2581 session_pty_cleanup(s);
2584 /* detach by removing callback */
2585 channel_cancel_cleanup(s->chanid);
2587 /* Close any X11 listeners associated with this session */
2588 if (s->x11_chanids != NULL) {
2589 for (i = 0; s->x11_chanids[i] != -1; i++) {
2590 session_close_x11(s->x11_chanids[i]);
2591 s->x11_chanids[i] = -1;
2600 session_destroy_all(void (*closefunc)(Session *))
2603 for (i = 0; i < sessions_nalloc; i++) {
2604 Session *s = &sessions[i];
2606 if (closefunc != NULL)
2615 session_tty_list(void)
2617 static char buf[1024];
2622 for (i = 0; i < sessions_nalloc; i++) {
2623 Session *s = &sessions[i];
2624 if (s->used && s->ttyfd != -1) {
2626 if (strncmp(s->tty, "/dev/", 5) != 0) {
2627 cp = strrchr(s->tty, '/');
2628 cp = (cp == NULL) ? s->tty : cp + 1;
2633 strlcat(buf, ",", sizeof buf);
2634 strlcat(buf, cp, sizeof buf);
2638 strlcpy(buf, "notty", sizeof buf);
2643 session_proctitle(Session *s)
2646 error("no user for session %d", s->self);
2648 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2652 session_setup_x11fwd(Session *s)
2655 char display[512], auth_display[512];
2656 char hostname[MAXHOSTNAMELEN];
2659 if (no_x11_forwarding_flag) {
2660 packet_send_debug("X11 forwarding disabled in user configuration file.");
2663 if (!options.x11_forwarding) {
2664 debug("X11 forwarding disabled in server configuration file.");
2667 if (!options.xauth_location ||
2668 (stat(options.xauth_location, &st) == -1)) {
2669 packet_send_debug("No xauth program; cannot forward with spoofing.");
2672 if (options.use_login) {
2673 packet_send_debug("X11 forwarding disabled; "
2674 "not compatible with UseLogin=yes.");
2677 if (s->display != NULL) {
2678 debug("X11 display already set.");
2681 if (x11_create_display_inet(options.x11_display_offset,
2682 options.x11_use_localhost, s->single_connection,
2683 &s->display_number, &s->x11_chanids) == -1) {
2684 debug("x11_create_display_inet failed.");
2687 for (i = 0; s->x11_chanids[i] != -1; i++) {
2688 channel_register_cleanup(s->x11_chanids[i],
2689 session_close_single_x11, 0);
2692 /* Set up a suitable value for the DISPLAY variable. */
2693 if (gethostname(hostname, sizeof(hostname)) < 0)
2694 fatal("gethostname: %.100s", strerror(errno));
2696 * auth_display must be used as the displayname when the
2697 * authorization entry is added with xauth(1). This will be
2698 * different than the DISPLAY string for localhost displays.
2700 if (options.x11_use_localhost) {
2701 snprintf(display, sizeof display, "localhost:%u.%u",
2702 s->display_number, s->screen);
2703 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2704 s->display_number, s->screen);
2705 s->display = xstrdup(display);
2706 s->auth_display = xstrdup(auth_display);
2708 #ifdef IPADDR_IN_DISPLAY
2710 struct in_addr my_addr;
2712 he = gethostbyname(hostname);
2714 error("Can't get IP address for X11 DISPLAY.");
2715 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2718 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2719 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2720 s->display_number, s->screen);
2722 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2723 s->display_number, s->screen);
2725 s->display = xstrdup(display);
2726 s->auth_display = xstrdup(display);
2733 do_authenticated2(Authctxt *authctxt)
2735 server_loop2(authctxt);
2739 do_cleanup(Authctxt *authctxt)
2741 static int called = 0;
2743 debug("do_cleanup");
2745 /* no cleanup if we're in the child for login shell */
2749 /* avoid double cleanup */
2754 if (authctxt == NULL)
2758 if (options.use_pam) {
2760 sshpam_thread_cleanup();
2764 if (!authctxt->authenticated)
2768 if (options.kerberos_ticket_cleanup &&
2770 krb5_cleanup_proc(authctxt);
2774 if (compat20 && options.gss_cleanup_creds)
2775 ssh_gssapi_cleanup_creds();
2778 /* remove agent socket */
2779 auth_sock_cleanup_proc(authctxt->pw);
2782 * Cleanup ptys/utmp only if privsep is disabled,
2783 * or if running in monitor.
2785 if (!use_privsep || mm_is_monitor())
2786 session_destroy_all(session_pty_cleanup2);