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.
38 #include <sys/types.h>
39 #include <sys/param.h>
40 #ifdef HAVE_SYS_STAT_H
41 # include <sys/stat.h>
43 #include <sys/socket.h>
47 #include <arpa/inet.h>
62 #include "openbsd-compat/sys-queue.h"
81 #include "auth-options.h"
82 #include "pathnames.h"
86 #include "serverloop.h"
91 #include "monitor_wrap.h"
94 #if defined(KRB5) && defined(USE_AFS)
98 #define IS_INTERNAL_SFTP(c) \
99 (!strncmp(c, INTERNAL_SFTP_NAME, sizeof(INTERNAL_SFTP_NAME) - 1) && \
100 (c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\0' || \
101 c[sizeof(INTERNAL_SFTP_NAME) - 1] == ' ' || \
102 c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\t'))
106 Session *session_new(void);
107 void session_set_fds(Session *, int, int, int, int);
108 void session_pty_cleanup(Session *);
109 void session_proctitle(Session *);
110 int session_setup_x11fwd(Session *);
111 int do_exec_pty(Session *, const char *);
112 int do_exec_no_pty(Session *, const char *);
113 int do_exec(Session *, const char *);
114 void do_login(Session *, const char *);
115 #ifdef LOGIN_NEEDS_UTMPX
116 static void do_pre_login(Session *s);
118 void do_child(Session *, const char *);
120 int check_quietlogin(Session *, const char *);
122 static void do_authenticated1(Authctxt *);
123 static void do_authenticated2(Authctxt *);
125 static int session_pty_req(Session *);
128 extern ServerOptions options;
129 extern char *__progname;
130 extern int log_stderr;
131 extern int debug_flag;
132 extern u_int utmp_len;
133 extern int startup_pipe;
134 extern void destroy_sensitive_data(void);
135 extern Buffer loginmsg;
137 /* original command from peer. */
138 const char *original_command = NULL;
141 static int sessions_first_unused = -1;
142 static int sessions_nalloc = 0;
143 static Session *sessions = NULL;
145 #define SUBSYSTEM_NONE 0
146 #define SUBSYSTEM_EXT 1
147 #define SUBSYSTEM_INT_SFTP 2
149 #ifdef HAVE_LOGIN_CAP
153 static int is_child = 0;
155 /* Name and directory of socket for authentication agent forwarding. */
156 static char *auth_sock_name = NULL;
157 static char *auth_sock_dir = NULL;
159 /* removes the agent forwarding socket */
162 auth_sock_cleanup_proc(struct passwd *pw)
164 if (auth_sock_name != NULL) {
165 temporarily_use_uid(pw);
166 unlink(auth_sock_name);
167 rmdir(auth_sock_dir);
168 auth_sock_name = NULL;
174 auth_input_request_forwarding(struct passwd * pw)
178 struct sockaddr_un sunaddr;
180 if (auth_sock_name != NULL) {
181 error("authentication forwarding requested twice.");
185 /* Temporarily drop privileged uid for mkdir/bind. */
186 temporarily_use_uid(pw);
188 /* Allocate a buffer for the socket name, and format the name. */
189 auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX");
191 /* Create private directory for socket */
192 if (mkdtemp(auth_sock_dir) == NULL) {
193 packet_send_debug("Agent forwarding disabled: "
194 "mkdtemp() failed: %.100s", strerror(errno));
196 xfree(auth_sock_dir);
197 auth_sock_dir = NULL;
201 xasprintf(&auth_sock_name, "%s/agent.%ld",
202 auth_sock_dir, (long) getpid());
204 /* Create the socket. */
205 sock = socket(AF_UNIX, SOCK_STREAM, 0);
207 error("socket: %.100s", strerror(errno));
212 /* Bind it to the name. */
213 memset(&sunaddr, 0, sizeof(sunaddr));
214 sunaddr.sun_family = AF_UNIX;
215 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
217 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
218 error("bind: %.100s", strerror(errno));
223 /* Restore the privileged uid. */
226 /* Start listening on the socket. */
227 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
228 error("listen: %.100s", strerror(errno));
232 /* Allocate a channel for the authentication agent socket. */
233 /* this shouldn't matter if its hpn or not - cjr */
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.
894 if (options.print_motd) {
895 #ifdef HAVE_LOGIN_CAP
896 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
899 f = fopen("/etc/motd", "r");
902 while (fgets(buf, sizeof(buf), f))
911 * Check for quiet login, either .hushlogin or command given.
914 check_quietlogin(Session *s, const char *command)
917 struct passwd *pw = s->pw;
920 /* Return 1 if .hushlogin exists or a command given. */
923 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
924 #ifdef HAVE_LOGIN_CAP
925 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
928 if (stat(buf, &st) >= 0)
935 * Sets the value of the given variable in the environment. If the variable
936 * already exists, its value is overridden.
939 child_set_env(char ***envp, u_int *envsizep, const char *name,
947 * If we're passed an uninitialized list, allocate a single null
948 * entry before continuing.
950 if (*envp == NULL && *envsizep == 0) {
951 *envp = xmalloc(sizeof(char *));
957 * Find the slot where the value should be stored. If the variable
958 * already exists, we reuse the slot; otherwise we append a new slot
959 * at the end of the array, expanding if necessary.
962 namelen = strlen(name);
963 for (i = 0; env[i]; i++)
964 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
967 /* Reuse the slot. */
970 /* New variable. Expand if necessary. */
972 if (i >= envsize - 1) {
974 fatal("child_set_env: too many env vars");
976 env = (*envp) = xrealloc(env, envsize, sizeof(char *));
979 /* Need to set the NULL pointer at end of array beyond the new slot. */
983 /* Allocate space and format the variable in the appropriate slot. */
984 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
985 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
989 * Reads environment variables from the given file and adds/overrides them
990 * into the environment. If the file does not exist, this does nothing.
991 * Otherwise, it must consist of empty lines, comments (line starts with '#')
992 * and assignments of the form name=value. No other forms are allowed.
995 read_environment_file(char ***env, u_int *envsize,
996 const char *filename)
1003 f = fopen(filename, "r");
1007 while (fgets(buf, sizeof(buf), f)) {
1008 if (++lineno > 1000)
1009 fatal("Too many lines in environment file %s", filename);
1010 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
1012 if (!*cp || *cp == '#' || *cp == '\n')
1015 cp[strcspn(cp, "\n")] = '\0';
1017 value = strchr(cp, '=');
1018 if (value == NULL) {
1019 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
1024 * Replace the equals sign by nul, and advance value to
1029 child_set_env(env, envsize, cp, value);
1034 #ifdef HAVE_ETC_DEFAULT_LOGIN
1036 * Return named variable from specified environment, or NULL if not present.
1039 child_get_env(char **env, const char *name)
1045 for (i=0; env[i] != NULL; i++)
1046 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
1047 return(env[i] + len + 1);
1052 * Read /etc/default/login.
1053 * We pick up the PATH (or SUPATH for root) and UMASK.
1056 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
1058 char **tmpenv = NULL, *var;
1059 u_int i, tmpenvsize = 0;
1063 * We don't want to copy the whole file to the child's environment,
1064 * so we use a temporary environment and copy the variables we're
1067 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
1073 var = child_get_env(tmpenv, "SUPATH");
1075 var = child_get_env(tmpenv, "PATH");
1077 child_set_env(env, envsize, "PATH", var);
1079 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
1080 if (sscanf(var, "%5lo", &mask) == 1)
1081 umask((mode_t)mask);
1083 for (i = 0; tmpenv[i] != NULL; i++)
1087 #endif /* HAVE_ETC_DEFAULT_LOGIN */
1090 copy_environment(char **source, char ***env, u_int *envsize)
1092 char *var_name, *var_val;
1098 for(i = 0; source[i] != NULL; i++) {
1099 var_name = xstrdup(source[i]);
1100 if ((var_val = strstr(var_name, "=")) == NULL) {
1106 debug3("Copy environment: %s=%s", var_name, var_val);
1107 child_set_env(env, envsize, var_name, var_val);
1114 do_setup_env(Session *s, const char *shell)
1119 struct passwd *pw = s->pw;
1120 #ifndef HAVE_LOGIN_CAP
1124 /* Initialize the environment. */
1126 env = xcalloc(envsize, sizeof(char *));
1131 * The Windows environment contains some setting which are
1132 * important for a running system. They must not be dropped.
1137 p = fetch_windows_environment();
1138 copy_environment(p, &env, &envsize);
1139 free_windows_environment(p);
1144 /* Allow any GSSAPI methods that we've used to alter
1145 * the childs environment as they see fit
1147 ssh_gssapi_do_child(&env, &envsize);
1150 if (!options.use_login) {
1151 /* Set basic environment. */
1152 for (i = 0; i < s->num_env; i++)
1153 child_set_env(&env, &envsize, s->env[i].name,
1156 child_set_env(&env, &envsize, "USER", pw->pw_name);
1157 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1159 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1161 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1162 #ifdef HAVE_LOGIN_CAP
1163 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1164 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1166 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1167 #else /* HAVE_LOGIN_CAP */
1168 # ifndef HAVE_CYGWIN
1170 * There's no standard path on Windows. The path contains
1171 * important components pointing to the system directories,
1172 * needed for loading shared libraries. So the path better
1173 * remains intact here.
1175 # ifdef HAVE_ETC_DEFAULT_LOGIN
1176 read_etc_default_login(&env, &envsize, pw->pw_uid);
1177 path = child_get_env(env, "PATH");
1178 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1179 if (path == NULL || *path == '\0') {
1180 child_set_env(&env, &envsize, "PATH",
1181 s->pw->pw_uid == 0 ?
1182 SUPERUSER_PATH : _PATH_STDPATH);
1184 # endif /* HAVE_CYGWIN */
1185 #endif /* HAVE_LOGIN_CAP */
1187 snprintf(buf, sizeof buf, "%.200s/%.50s",
1188 _PATH_MAILDIR, pw->pw_name);
1189 child_set_env(&env, &envsize, "MAIL", buf);
1191 /* Normal systems set SHELL by default. */
1192 child_set_env(&env, &envsize, "SHELL", shell);
1195 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1197 /* Set custom environment options from RSA authentication. */
1198 if (!options.use_login) {
1199 while (custom_environment) {
1200 struct envstring *ce = custom_environment;
1203 for (i = 0; str[i] != '=' && str[i]; i++)
1205 if (str[i] == '=') {
1207 child_set_env(&env, &envsize, str, str + i + 1);
1209 custom_environment = ce->next;
1215 /* SSH_CLIENT deprecated */
1216 snprintf(buf, sizeof buf, "%.50s %d %d",
1217 get_remote_ipaddr(), get_remote_port(), get_local_port());
1218 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1220 laddr = get_local_ipaddr(packet_get_connection_in());
1221 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1222 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1224 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1227 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1229 child_set_env(&env, &envsize, "TERM", s->term);
1231 child_set_env(&env, &envsize, "DISPLAY", s->display);
1232 if (original_command)
1233 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1237 if (cray_tmpdir[0] != '\0')
1238 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1239 #endif /* _UNICOS */
1242 * Since we clear KRB5CCNAME at startup, if it's set now then it
1243 * must have been set by a native authentication method (eg AIX or
1244 * SIA), so copy it to the child.
1249 if ((cp = getenv("KRB5CCNAME")) != NULL)
1250 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1257 if ((cp = getenv("AUTHSTATE")) != NULL)
1258 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1259 read_environment_file(&env, &envsize, "/etc/environment");
1263 if (s->authctxt->krb5_ccname)
1264 child_set_env(&env, &envsize, "KRB5CCNAME",
1265 s->authctxt->krb5_ccname);
1269 * Pull in any environment variables that may have
1272 if (options.use_pam) {
1275 p = fetch_pam_child_environment();
1276 copy_environment(p, &env, &envsize);
1277 free_pam_environment(p);
1279 p = fetch_pam_environment();
1280 copy_environment(p, &env, &envsize);
1281 free_pam_environment(p);
1283 #endif /* USE_PAM */
1285 if (auth_sock_name != NULL)
1286 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1289 /* read $HOME/.ssh/environment. */
1290 if (options.permit_user_env && !options.use_login) {
1291 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1292 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1293 read_environment_file(&env, &envsize, buf);
1296 /* dump the environment */
1297 fprintf(stderr, "Environment:\n");
1298 for (i = 0; env[i]; i++)
1299 fprintf(stderr, " %.200s\n", env[i]);
1305 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1306 * first in this order).
1309 do_rc_files(Session *s, const char *shell)
1317 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1319 /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
1320 if (!s->is_subsystem && options.adm_forced_command == NULL &&
1321 !no_user_rc && stat(_PATH_SSH_USER_RC, &st) >= 0) {
1322 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1323 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1325 fprintf(stderr, "Running %s\n", cmd);
1326 f = popen(cmd, "w");
1329 fprintf(f, "%s %s\n", s->auth_proto,
1333 fprintf(stderr, "Could not run %s\n",
1335 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1337 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1338 _PATH_SSH_SYSTEM_RC);
1339 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1342 fprintf(f, "%s %s\n", s->auth_proto,
1346 fprintf(stderr, "Could not run %s\n",
1347 _PATH_SSH_SYSTEM_RC);
1348 } else if (do_xauth && options.xauth_location != NULL) {
1349 /* Add authority data to .Xauthority if appropriate. */
1352 "Running %.500s remove %.100s\n",
1353 options.xauth_location, s->auth_display);
1355 "%.500s add %.100s %.100s %.100s\n",
1356 options.xauth_location, s->auth_display,
1357 s->auth_proto, s->auth_data);
1359 snprintf(cmd, sizeof cmd, "%s -q -",
1360 options.xauth_location);
1361 f = popen(cmd, "w");
1363 fprintf(f, "remove %s\n",
1365 fprintf(f, "add %s %s %s\n",
1366 s->auth_display, s->auth_proto,
1370 fprintf(stderr, "Could not run %s\n",
1377 do_nologin(struct passwd *pw)
1382 #ifdef HAVE_LOGIN_CAP
1383 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1384 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1385 _PATH_NOLOGIN), "r");
1388 f = fopen(_PATH_NOLOGIN, "r");
1391 /* /etc/nologin exists. Print its contents and exit. */
1392 logit("User %.100s not allowed because %s exists",
1393 pw->pw_name, _PATH_NOLOGIN);
1394 while (fgets(buf, sizeof(buf), f))
1403 * Chroot into a directory after checking it for safety: all path components
1404 * must be root-owned directories with strict permissions.
1407 safely_chroot(const char *path, uid_t uid)
1410 char component[MAXPATHLEN];
1414 fatal("chroot path does not begin at root");
1415 if (strlen(path) >= sizeof(component))
1416 fatal("chroot path too long");
1419 * Descend the path, checking that each component is a
1420 * root-owned directory with strict permissions.
1422 for (cp = path; cp != NULL;) {
1423 if ((cp = strchr(cp, '/')) == NULL)
1424 strlcpy(component, path, sizeof(component));
1427 memcpy(component, path, cp - path);
1428 component[cp - path] = '\0';
1431 debug3("%s: checking '%s'", __func__, component);
1433 if (stat(component, &st) != 0)
1434 fatal("%s: stat(\"%s\"): %s", __func__,
1435 component, strerror(errno));
1436 if (st.st_uid != 0 || (st.st_mode & 022) != 0)
1437 fatal("bad ownership or modes for chroot "
1438 "directory %s\"%s\"",
1439 cp == NULL ? "" : "component ", component);
1440 if (!S_ISDIR(st.st_mode))
1441 fatal("chroot path %s\"%s\" is not a directory",
1442 cp == NULL ? "" : "component ", component);
1446 if (chdir(path) == -1)
1447 fatal("Unable to chdir to chroot path \"%s\": "
1448 "%s", path, strerror(errno));
1449 if (chroot(path) == -1)
1450 fatal("chroot(\"%s\"): %s", path, strerror(errno));
1451 if (chdir("/") == -1)
1452 fatal("%s: chdir(/) after chroot: %s",
1453 __func__, strerror(errno));
1454 verbose("Changed root directory to \"%s\"", path);
1457 /* Set login name, uid, gid, and groups. */
1459 do_setusercontext(struct passwd *pw)
1461 char *chroot_path, *tmp;
1464 /* Cache selinux status for later use */
1465 (void)ssh_selinux_enabled();
1469 if (getuid() == 0 || geteuid() == 0)
1470 #endif /* HAVE_CYGWIN */
1473 #ifdef HAVE_SETPCRED
1474 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1475 fatal("Failed to set process credentials");
1476 #endif /* HAVE_SETPCRED */
1477 #ifdef HAVE_LOGIN_CAP
1482 if (options.use_pam) {
1483 do_pam_setcred(use_privsep);
1485 # endif /* USE_PAM */
1486 if (setusercontext(lc, pw, pw->pw_uid,
1487 (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1488 perror("unable to set user context");
1492 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1493 /* Sets login uid for accounting */
1494 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1495 error("setluid: %s", strerror(errno));
1496 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1498 if (setlogin(pw->pw_name) < 0)
1499 error("setlogin failed: %s", strerror(errno));
1500 if (setgid(pw->pw_gid) < 0) {
1504 /* Initialize the group list. */
1505 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1506 perror("initgroups");
1512 * PAM credentials may take the form of supplementary groups.
1513 * These will have been wiped by the above initgroups() call.
1514 * Reestablish them here.
1516 if (options.use_pam) {
1517 do_pam_setcred(use_privsep);
1519 # endif /* USE_PAM */
1520 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1521 irix_setusercontext(pw);
1522 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1527 if (set_id(pw->pw_name) != 0) {
1530 # endif /* USE_LIBIAF */
1533 if (options.chroot_directory != NULL &&
1534 strcasecmp(options.chroot_directory, "none") != 0) {
1535 tmp = tilde_expand_filename(options.chroot_directory,
1537 chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1538 "u", pw->pw_name, (char *)NULL);
1539 safely_chroot(chroot_path, pw->pw_uid);
1544 #ifdef HAVE_LOGIN_CAP
1545 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
1546 perror("unable to set user context (setuser)");
1550 /* Permanently switch to the desired uid. */
1551 permanently_set_uid(pw);
1558 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1559 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1562 ssh_selinux_setup_exec_context(pw->pw_name);
1567 do_pwchange(Session *s)
1570 fprintf(stderr, "WARNING: Your password has expired.\n");
1571 if (s->ttyfd != -1) {
1573 "You must change your password now and login again!\n");
1574 #ifdef PASSWD_NEEDS_USERNAME
1575 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1578 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1583 "Password change required but no TTY available.\n");
1589 launch_login(struct passwd *pw, const char *hostname)
1591 /* Launch login(1). */
1593 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1594 #ifdef xxxLOGIN_NEEDS_TERM
1595 (s->term ? s->term : "unknown"),
1596 #endif /* LOGIN_NEEDS_TERM */
1597 #ifdef LOGIN_NO_ENDOPT
1598 "-p", "-f", pw->pw_name, (char *)NULL);
1600 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1603 /* Login couldn't be executed, die. */
1610 child_close_fds(void)
1614 if (packet_get_connection_in() == packet_get_connection_out())
1615 close(packet_get_connection_in());
1617 close(packet_get_connection_in());
1618 close(packet_get_connection_out());
1621 * Close all descriptors related to channels. They will still remain
1622 * open in the parent.
1624 /* XXX better use close-on-exec? -markus */
1625 channel_close_all();
1628 * Close any extra file descriptors. Note that there may still be
1629 * descriptors left by system functions. They will be closed later.
1634 * Close any extra open file descriptors so that we don't have them
1635 * hanging around in clients. Note that we want to do this after
1636 * initgroups, because at least on Solaris 2.3 it leaves file
1639 for (i = 3; i < 64; i++)
1644 * Performs common processing for the child, such as setting up the
1645 * environment, closing extra file descriptors, setting the user and group
1646 * ids, and executing the command or shell.
1650 do_child(Session *s, const char *command)
1652 extern char **environ;
1654 char *argv[ARGV_MAX];
1655 const char *shell, *shell0, *hostname = NULL;
1656 struct passwd *pw = s->pw;
1659 /* remove hostkey from the child's memory */
1660 destroy_sensitive_data();
1662 /* Force a password change */
1663 if (s->authctxt->force_pwchange) {
1664 do_setusercontext(pw);
1670 /* login(1) is only called if we execute the login shell */
1671 if (options.use_login && command != NULL)
1672 options.use_login = 0;
1675 cray_setup(pw->pw_uid, pw->pw_name, command);
1676 #endif /* _UNICOS */
1679 * Login(1) does this as well, and it needs uid 0 for the "-h"
1680 * switch, so we let login(1) to this for us.
1682 if (!options.use_login) {
1684 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1685 if (!check_quietlogin(s, command))
1687 #else /* HAVE_OSF_SIA */
1688 /* When PAM is enabled we rely on it to do the nologin check */
1689 if (!options.use_pam)
1691 do_setusercontext(pw);
1693 * PAM session modules in do_setusercontext may have
1694 * generated messages, so if this in an interactive
1695 * login then display them too.
1697 if (!check_quietlogin(s, command))
1699 #endif /* HAVE_OSF_SIA */
1703 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1704 debug3("PAM session not opened, exiting");
1711 * Get the shell from the password data. An empty shell field is
1712 * legal, and means /bin/sh.
1714 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1717 * Make sure $SHELL points to the shell from the password file,
1718 * even if shell is overridden from login.conf
1720 env = do_setup_env(s, shell);
1722 #ifdef HAVE_LOGIN_CAP
1723 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1726 /* we have to stash the hostname before we close our socket. */
1727 if (options.use_login)
1728 hostname = get_remote_name_or_ip(utmp_len,
1731 * Close the connection descriptors; note that this is the child, and
1732 * the server will still have the socket open, and it is important
1733 * that we do not shutdown it. Note that the descriptors cannot be
1734 * closed before building the environment, as we call
1735 * get_remote_ipaddr there.
1740 * Must take new environment into use so that .ssh/rc,
1741 * /etc/ssh/sshrc and xauth are run in the proper environment.
1745 #if defined(KRB5) && defined(USE_AFS)
1747 * At this point, we check to see if AFS is active and if we have
1748 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1749 * if we can (and need to) extend the ticket into an AFS token. If
1750 * we don't do this, we run into potential problems if the user's
1751 * home directory is in AFS and it's not world-readable.
1754 if (options.kerberos_get_afs_token && k_hasafs() &&
1755 (s->authctxt->krb5_ctx != NULL)) {
1758 debug("Getting AFS token");
1762 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1763 krb5_afslog(s->authctxt->krb5_ctx,
1764 s->authctxt->krb5_fwd_ccache, cell, NULL);
1766 krb5_afslog_home(s->authctxt->krb5_ctx,
1767 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1771 /* Change current directory to the user's home directory. */
1772 if (chdir(pw->pw_dir) < 0) {
1773 /* Suppress missing homedir warning for chroot case */
1774 #ifdef HAVE_LOGIN_CAP
1775 r = login_getcapbool(lc, "requirehome", 0);
1777 if (r || options.chroot_directory == NULL)
1778 fprintf(stderr, "Could not chdir to home "
1779 "directory %s: %s\n", pw->pw_dir,
1785 closefrom(STDERR_FILENO + 1);
1787 if (!options.use_login)
1788 do_rc_files(s, shell);
1790 /* restore SIGPIPE for child */
1791 signal(SIGPIPE, SIG_DFL);
1793 if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1794 extern int optind, optreset;
1798 setproctitle("%s@internal-sftp-server", s->pw->pw_name);
1799 args = xstrdup(command ? command : "sftp-server");
1800 for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1801 if (i < ARGV_MAX - 1)
1804 optind = optreset = 1;
1805 __progname = argv[0];
1806 exit(sftp_server_main(i, argv, s->pw));
1809 if (options.use_login) {
1810 launch_login(pw, hostname);
1814 /* Get the last component of the shell name. */
1815 if ((shell0 = strrchr(shell, '/')) != NULL)
1821 * If we have no command, execute the shell. In this case, the shell
1822 * name to be passed in argv[0] is preceded by '-' to indicate that
1823 * this is a login shell.
1828 /* Start the shell. Set initial character to '-'. */
1831 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1832 >= sizeof(argv0) - 1) {
1838 /* Execute the shell. */
1841 execve(shell, argv, env);
1843 /* Executing the shell failed. */
1848 * Execute the command using the user's shell. This uses the -c
1849 * option to execute the command.
1851 argv[0] = (char *) shell0;
1853 argv[2] = (char *) command;
1855 execve(shell, argv, env);
1861 session_unused(int id)
1863 debug3("%s: session id %d unused", __func__, id);
1864 if (id >= options.max_sessions ||
1865 id >= sessions_nalloc) {
1866 fatal("%s: insane session id %d (max %d nalloc %d)",
1867 __func__, id, options.max_sessions, sessions_nalloc);
1869 bzero(&sessions[id], sizeof(*sessions));
1870 sessions[id].self = id;
1871 sessions[id].used = 0;
1872 sessions[id].chanid = -1;
1873 sessions[id].ptyfd = -1;
1874 sessions[id].ttyfd = -1;
1875 sessions[id].ptymaster = -1;
1876 sessions[id].x11_chanids = NULL;
1877 sessions[id].next_unused = sessions_first_unused;
1878 sessions_first_unused = id;
1886 if (sessions_first_unused == -1) {
1887 if (sessions_nalloc >= options.max_sessions)
1889 debug2("%s: allocate (allocated %d max %d)",
1890 __func__, sessions_nalloc, options.max_sessions);
1891 tmp = xrealloc(sessions, sessions_nalloc + 1,
1894 error("%s: cannot allocate %d sessions",
1895 __func__, sessions_nalloc + 1);
1899 session_unused(sessions_nalloc++);
1902 if (sessions_first_unused >= sessions_nalloc ||
1903 sessions_first_unused < 0) {
1904 fatal("%s: insane first_unused %d max %d nalloc %d",
1905 __func__, sessions_first_unused, options.max_sessions,
1909 s = &sessions[sessions_first_unused];
1911 fatal("%s: session %d already used",
1912 __func__, sessions_first_unused);
1914 sessions_first_unused = s->next_unused;
1916 s->next_unused = -1;
1917 debug("session_new: session %d", s->self);
1926 for (i = 0; i < sessions_nalloc; i++) {
1927 Session *s = &sessions[i];
1929 debug("dump: used %d next_unused %d session %d %p "
1930 "channel %d pid %ld",
1941 session_open(Authctxt *authctxt, int chanid)
1943 Session *s = session_new();
1944 debug("session_open: channel %d", chanid);
1946 error("no more sessions");
1949 s->authctxt = authctxt;
1950 s->pw = authctxt->pw;
1951 if (s->pw == NULL || !authctxt->valid)
1952 fatal("no user for session %d", s->self);
1953 debug("session_open: session %d: link with channel %d", s->self, chanid);
1959 session_by_tty(char *tty)
1962 for (i = 0; i < sessions_nalloc; i++) {
1963 Session *s = &sessions[i];
1964 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1965 debug("session_by_tty: session %d tty %s", i, tty);
1969 debug("session_by_tty: unknown tty %.100s", tty);
1975 session_by_channel(int id)
1978 for (i = 0; i < sessions_nalloc; i++) {
1979 Session *s = &sessions[i];
1980 if (s->used && s->chanid == id) {
1981 debug("session_by_channel: session %d channel %d",
1986 debug("session_by_channel: unknown channel %d", id);
1992 session_by_x11_channel(int id)
1996 for (i = 0; i < sessions_nalloc; i++) {
1997 Session *s = &sessions[i];
1999 if (s->x11_chanids == NULL || !s->used)
2001 for (j = 0; s->x11_chanids[j] != -1; j++) {
2002 if (s->x11_chanids[j] == id) {
2003 debug("session_by_x11_channel: session %d "
2004 "channel %d", s->self, id);
2009 debug("session_by_x11_channel: unknown channel %d", id);
2015 session_by_pid(pid_t pid)
2018 debug("session_by_pid: pid %ld", (long)pid);
2019 for (i = 0; i < sessions_nalloc; i++) {
2020 Session *s = &sessions[i];
2021 if (s->used && s->pid == pid)
2024 error("session_by_pid: unknown pid %ld", (long)pid);
2030 session_window_change_req(Session *s)
2032 s->col = packet_get_int();
2033 s->row = packet_get_int();
2034 s->xpixel = packet_get_int();
2035 s->ypixel = packet_get_int();
2037 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
2042 session_pty_req(Session *s)
2048 debug("Allocating a pty not permitted for this authentication.");
2051 if (s->ttyfd != -1) {
2052 packet_disconnect("Protocol error: you already have a pty.");
2056 s->term = packet_get_string(&len);
2059 s->col = packet_get_int();
2060 s->row = packet_get_int();
2062 s->row = packet_get_int();
2063 s->col = packet_get_int();
2065 s->xpixel = packet_get_int();
2066 s->ypixel = packet_get_int();
2068 if (strcmp(s->term, "") == 0) {
2073 /* Allocate a pty and open it. */
2074 debug("Allocating pty.");
2075 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
2082 error("session_pty_req: session %d alloc failed", s->self);
2085 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
2087 /* for SSH1 the tty modes length is not given */
2089 n_bytes = packet_remaining();
2090 tty_parse_modes(s->ttyfd, &n_bytes);
2093 pty_setowner(s->pw, s->tty);
2095 /* Set window size from the packet. */
2096 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
2099 session_proctitle(s);
2104 session_subsystem_req(Session *s)
2109 char *prog, *cmd, *subsys = packet_get_string(&len);
2113 logit("subsystem request for %.100s", subsys);
2115 for (i = 0; i < options.num_subsystems; i++) {
2116 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
2117 prog = options.subsystem_command[i];
2118 cmd = options.subsystem_args[i];
2119 if (!strcmp(INTERNAL_SFTP_NAME, prog)) {
2120 s->is_subsystem = SUBSYSTEM_INT_SFTP;
2121 } else if (stat(prog, &st) < 0) {
2122 error("subsystem: cannot stat %s: %s", prog,
2126 s->is_subsystem = SUBSYSTEM_EXT;
2128 debug("subsystem: exec() %s", cmd);
2129 success = do_exec(s, cmd) == 0;
2135 logit("subsystem request for %.100s failed, subsystem not found",
2143 session_x11_req(Session *s)
2147 if (s->auth_proto != NULL || s->auth_data != NULL) {
2148 error("session_x11_req: session %d: "
2149 "x11 forwarding already active", s->self);
2152 s->single_connection = packet_get_char();
2153 s->auth_proto = packet_get_string(NULL);
2154 s->auth_data = packet_get_string(NULL);
2155 s->screen = packet_get_int();
2158 success = session_setup_x11fwd(s);
2160 xfree(s->auth_proto);
2161 xfree(s->auth_data);
2162 s->auth_proto = NULL;
2163 s->auth_data = NULL;
2169 session_shell_req(Session *s)
2172 return do_exec(s, NULL) == 0;
2176 session_exec_req(Session *s)
2180 char *command = packet_get_string(&len);
2182 success = do_exec(s, command) == 0;
2188 session_break_req(Session *s)
2191 packet_get_int(); /* ignored */
2194 if (s->ttyfd == -1 || tcsendbreak(s->ttyfd, 0) < 0)
2200 session_env_req(Session *s)
2203 u_int name_len, val_len, i;
2205 name = packet_get_string(&name_len);
2206 val = packet_get_string(&val_len);
2209 /* Don't set too many environment variables */
2210 if (s->num_env > 128) {
2211 debug2("Ignoring env request %s: too many env vars", name);
2215 for (i = 0; i < options.num_accept_env; i++) {
2216 if (match_pattern(name, options.accept_env[i])) {
2217 debug2("Setting env %d: %s=%s", s->num_env, name, val);
2218 s->env = xrealloc(s->env, s->num_env + 1,
2220 s->env[s->num_env].name = name;
2221 s->env[s->num_env].val = val;
2226 debug2("Ignoring env request %s: disallowed name", name);
2235 session_auth_agent_req(Session *s)
2237 static int called = 0;
2239 if (no_agent_forwarding_flag || !options.allow_agent_forwarding) {
2240 debug("session_auth_agent_req: no_agent_forwarding_flag");
2247 return auth_input_request_forwarding(s->pw);
2252 session_input_channel_req(Channel *c, const char *rtype)
2257 if ((s = session_by_channel(c->self)) == NULL) {
2258 logit("session_input_channel_req: no session %d req %.100s",
2262 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2265 * a session is in LARVAL state until a shell, a command
2266 * or a subsystem is executed
2268 if (c->type == SSH_CHANNEL_LARVAL) {
2269 if (strcmp(rtype, "shell") == 0) {
2270 success = session_shell_req(s);
2271 } else if (strcmp(rtype, "exec") == 0) {
2272 success = session_exec_req(s);
2273 } else if (strcmp(rtype, "pty-req") == 0) {
2274 success = session_pty_req(s);
2275 } else if (strcmp(rtype, "x11-req") == 0) {
2276 success = session_x11_req(s);
2277 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2278 success = session_auth_agent_req(s);
2279 } else if (strcmp(rtype, "subsystem") == 0) {
2280 success = session_subsystem_req(s);
2281 } else if (strcmp(rtype, "env") == 0) {
2282 success = session_env_req(s);
2285 if (strcmp(rtype, "window-change") == 0) {
2286 success = session_window_change_req(s);
2287 } else if (strcmp(rtype, "break") == 0) {
2288 success = session_break_req(s);
2295 session_set_fds(Session *s, int fdin, int fdout, int fderr, int is_tty)
2298 fatal("session_set_fds: called for proto != 2.0");
2300 * now that have a child and a pipe to the child,
2301 * we can activate our channel and register the fd's
2303 if (s->chanid == -1)
2304 fatal("no channel for session %d", s->self);
2305 if (options.hpn_disabled)
2306 channel_set_fds(s->chanid,
2308 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2309 1, is_tty, CHAN_SES_WINDOW_DEFAULT);
2311 channel_set_fds(s->chanid,
2313 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2314 1, is_tty, options.hpn_buffer_size);
2318 * Function to perform pty cleanup. Also called if we get aborted abnormally
2319 * (e.g., due to a dropped connection).
2322 session_pty_cleanup2(Session *s)
2325 error("session_pty_cleanup: no session");
2331 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2333 /* Record that the user has logged out. */
2335 record_logout(s->pid, s->tty, s->pw->pw_name);
2337 /* Release the pseudo-tty. */
2339 pty_release(s->tty);
2342 * Close the server side of the socket pairs. We must do this after
2343 * the pty cleanup, so that another process doesn't get this pty
2344 * while we're still cleaning up.
2346 if (s->ptymaster != -1 && close(s->ptymaster) < 0)
2347 error("close(s->ptymaster/%d): %s",
2348 s->ptymaster, strerror(errno));
2350 /* unlink pty from session */
2355 session_pty_cleanup(Session *s)
2357 PRIVSEP(session_pty_cleanup2(s));
2363 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2378 return "SIG@openssh.com";
2382 session_close_x11(int id)
2386 if ((c = channel_by_id(id)) == NULL) {
2387 debug("session_close_x11: x11 channel %d missing", id);
2389 /* Detach X11 listener */
2390 debug("session_close_x11: detach x11 channel %d", id);
2391 channel_cancel_cleanup(id);
2392 if (c->ostate != CHAN_OUTPUT_CLOSED)
2398 session_close_single_x11(int id, void *arg)
2403 debug3("session_close_single_x11: channel %d", id);
2404 channel_cancel_cleanup(id);
2405 if ((s = session_by_x11_channel(id)) == NULL)
2406 fatal("session_close_single_x11: no x11 channel %d", id);
2407 for (i = 0; s->x11_chanids[i] != -1; i++) {
2408 debug("session_close_single_x11: session %d: "
2409 "closing channel %d", s->self, s->x11_chanids[i]);
2411 * The channel "id" is already closing, but make sure we
2412 * close all of its siblings.
2414 if (s->x11_chanids[i] != id)
2415 session_close_x11(s->x11_chanids[i]);
2417 xfree(s->x11_chanids);
2418 s->x11_chanids = NULL;
2423 if (s->auth_proto) {
2424 xfree(s->auth_proto);
2425 s->auth_proto = NULL;
2428 xfree(s->auth_data);
2429 s->auth_data = NULL;
2431 if (s->auth_display) {
2432 xfree(s->auth_display);
2433 s->auth_display = NULL;
2438 session_exit_message(Session *s, int status)
2442 if ((c = channel_lookup(s->chanid)) == NULL)
2443 fatal("session_exit_message: session %d: no channel %d",
2444 s->self, s->chanid);
2445 debug("session_exit_message: session %d channel %d pid %ld",
2446 s->self, s->chanid, (long)s->pid);
2448 if (WIFEXITED(status)) {
2449 channel_request_start(s->chanid, "exit-status", 0);
2450 packet_put_int(WEXITSTATUS(status));
2452 } else if (WIFSIGNALED(status)) {
2453 channel_request_start(s->chanid, "exit-signal", 0);
2454 packet_put_cstring(sig2name(WTERMSIG(status)));
2456 packet_put_char(WCOREDUMP(status)? 1 : 0);
2457 #else /* WCOREDUMP */
2459 #endif /* WCOREDUMP */
2460 packet_put_cstring("");
2461 packet_put_cstring("");
2464 /* Some weird exit cause. Just exit. */
2465 packet_disconnect("wait returned status %04x.", status);
2468 /* disconnect channel */
2469 debug("session_exit_message: release channel %d", s->chanid);
2472 * Adjust cleanup callback attachment to send close messages when
2473 * the channel gets EOF. The session will be then be closed
2474 * by session_close_by_channel when the childs close their fds.
2476 channel_register_cleanup(c->self, session_close_by_channel, 1);
2479 * emulate a write failure with 'chan_write_failed', nobody will be
2480 * interested in data we write.
2481 * Note that we must not call 'chan_read_failed', since there could
2482 * be some more data waiting in the pipe.
2484 if (c->ostate != CHAN_OUTPUT_CLOSED)
2485 chan_write_failed(c);
2489 session_close(Session *s)
2493 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2495 session_pty_cleanup(s);
2501 xfree(s->x11_chanids);
2502 if (s->auth_display)
2503 xfree(s->auth_display);
2505 xfree(s->auth_data);
2507 xfree(s->auth_proto);
2508 if (s->env != NULL) {
2509 for (i = 0; i < s->num_env; i++) {
2510 xfree(s->env[i].name);
2511 xfree(s->env[i].val);
2515 session_proctitle(s);
2516 session_unused(s->self);
2520 session_close_by_pid(pid_t pid, int status)
2522 Session *s = session_by_pid(pid);
2524 debug("session_close_by_pid: no session for pid %ld",
2528 if (s->chanid != -1)
2529 session_exit_message(s, status);
2531 session_pty_cleanup(s);
2536 * this is called when a channel dies before
2537 * the session 'child' itself dies
2540 session_close_by_channel(int id, void *arg)
2542 Session *s = session_by_channel(id);
2546 debug("session_close_by_channel: no session for id %d", id);
2549 debug("session_close_by_channel: channel %d child %ld",
2552 debug("session_close_by_channel: channel %d: has child", id);
2554 * delay detach of session, but release pty, since
2555 * the fd's to the child are already closed
2558 session_pty_cleanup(s);
2561 /* detach by removing callback */
2562 channel_cancel_cleanup(s->chanid);
2564 /* Close any X11 listeners associated with this session */
2565 if (s->x11_chanids != NULL) {
2566 for (i = 0; s->x11_chanids[i] != -1; i++) {
2567 session_close_x11(s->x11_chanids[i]);
2568 s->x11_chanids[i] = -1;
2577 session_destroy_all(void (*closefunc)(Session *))
2580 for (i = 0; i < sessions_nalloc; i++) {
2581 Session *s = &sessions[i];
2583 if (closefunc != NULL)
2592 session_tty_list(void)
2594 static char buf[1024];
2599 for (i = 0; i < sessions_nalloc; i++) {
2600 Session *s = &sessions[i];
2601 if (s->used && s->ttyfd != -1) {
2603 if (strncmp(s->tty, "/dev/", 5) != 0) {
2604 cp = strrchr(s->tty, '/');
2605 cp = (cp == NULL) ? s->tty : cp + 1;
2610 strlcat(buf, ",", sizeof buf);
2611 strlcat(buf, cp, sizeof buf);
2615 strlcpy(buf, "notty", sizeof buf);
2620 session_proctitle(Session *s)
2623 error("no user for session %d", s->self);
2625 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2629 session_setup_x11fwd(Session *s)
2632 char display[512], auth_display[512];
2633 char hostname[MAXHOSTNAMELEN];
2636 if (no_x11_forwarding_flag) {
2637 packet_send_debug("X11 forwarding disabled in user configuration file.");
2640 if (!options.x11_forwarding) {
2641 debug("X11 forwarding disabled in server configuration file.");
2644 if (!options.xauth_location ||
2645 (stat(options.xauth_location, &st) == -1)) {
2646 packet_send_debug("No xauth program; cannot forward with spoofing.");
2649 if (options.use_login) {
2650 packet_send_debug("X11 forwarding disabled; "
2651 "not compatible with UseLogin=yes.");
2654 if (s->display != NULL) {
2655 debug("X11 display already set.");
2658 if (x11_create_display_inet(options.x11_display_offset,
2659 options.x11_use_localhost, s->single_connection,
2660 &s->display_number, &s->x11_chanids) == -1) {
2661 debug("x11_create_display_inet failed.");
2664 for (i = 0; s->x11_chanids[i] != -1; i++) {
2665 channel_register_cleanup(s->x11_chanids[i],
2666 session_close_single_x11, 0);
2669 /* Set up a suitable value for the DISPLAY variable. */
2670 if (gethostname(hostname, sizeof(hostname)) < 0)
2671 fatal("gethostname: %.100s", strerror(errno));
2673 * auth_display must be used as the displayname when the
2674 * authorization entry is added with xauth(1). This will be
2675 * different than the DISPLAY string for localhost displays.
2677 if (options.x11_use_localhost) {
2678 snprintf(display, sizeof display, "localhost:%u.%u",
2679 s->display_number, s->screen);
2680 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2681 s->display_number, s->screen);
2682 s->display = xstrdup(display);
2683 s->auth_display = xstrdup(auth_display);
2685 #ifdef IPADDR_IN_DISPLAY
2687 struct in_addr my_addr;
2689 he = gethostbyname(hostname);
2691 error("Can't get IP address for X11 DISPLAY.");
2692 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2695 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2696 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2697 s->display_number, s->screen);
2699 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2700 s->display_number, s->screen);
2702 s->display = xstrdup(display);
2703 s->auth_display = xstrdup(display);
2710 do_authenticated2(Authctxt *authctxt)
2712 server_loop2(authctxt);
2716 do_cleanup(Authctxt *authctxt)
2718 static int called = 0;
2720 debug("do_cleanup");
2722 /* no cleanup if we're in the child for login shell */
2726 /* avoid double cleanup */
2731 if (authctxt == NULL)
2735 if (options.use_pam) {
2737 sshpam_thread_cleanup();
2741 if (!authctxt->authenticated)
2745 if (options.kerberos_ticket_cleanup &&
2747 krb5_cleanup_proc(authctxt);
2751 if (compat20 && options.gss_cleanup_creds)
2752 ssh_gssapi_cleanup_creds();
2755 /* remove agent socket */
2756 auth_sock_cleanup_proc(authctxt->pw);
2759 * Cleanup ptys/utmp only if privsep is disabled,
2760 * or if running in monitor.
2762 if (!use_privsep || mm_is_monitor())
2763 session_destroy_all(session_pty_cleanup2);