1 /* $OpenBSD: session.c,v 1.219 2006/08/29 10:40:19 djm Exp $ */
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * As far as I am concerned, the code I have written for this software
7 * can be used freely for any purpose. Any derived versions of this
8 * software must be clearly marked as such, and if the derived work is
9 * incompatible with the protocol description in the RFC file, it must be
10 * called by a name other than "ssh" or "Secure Shell".
12 * SSH2 support by Markus Friedl.
13 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 #include <sys/types.h>
39 #include <sys/param.h>
40 #ifdef HAVE_SYS_STAT_H
41 # include <sys/stat.h>
43 #include <sys/socket.h>
47 #include <arpa/inet.h>
80 #include "auth-options.h"
81 #include "pathnames.h"
85 #include "serverloop.h"
89 #include "monitor_wrap.h"
91 #if defined(KRB5) && defined(USE_AFS)
97 Session *session_new(void);
98 void session_set_fds(Session *, int, int, int);
99 void session_pty_cleanup(Session *);
100 void session_proctitle(Session *);
101 int session_setup_x11fwd(Session *);
102 void do_exec_pty(Session *, const char *);
103 void do_exec_no_pty(Session *, const char *);
104 void do_exec(Session *, const char *);
105 void do_login(Session *, const char *);
106 #ifdef LOGIN_NEEDS_UTMPX
107 static void do_pre_login(Session *s);
109 void do_child(Session *, const char *);
111 int check_quietlogin(Session *, const char *);
113 static void do_authenticated1(Authctxt *);
114 static void do_authenticated2(Authctxt *);
116 static int session_pty_req(Session *);
119 extern ServerOptions options;
120 extern char *__progname;
121 extern int log_stderr;
122 extern int debug_flag;
123 extern u_int utmp_len;
124 extern int startup_pipe;
125 extern void destroy_sensitive_data(void);
126 extern Buffer loginmsg;
128 /* original command from peer. */
129 const char *original_command = NULL;
132 #define MAX_SESSIONS 10
133 Session sessions[MAX_SESSIONS];
135 #ifdef HAVE_LOGIN_CAP
139 static int is_child = 0;
141 /* Name and directory of socket for authentication agent forwarding. */
142 static char *auth_sock_name = NULL;
143 static char *auth_sock_dir = NULL;
145 /* removes the agent forwarding socket */
148 auth_sock_cleanup_proc(struct passwd *pw)
150 if (auth_sock_name != NULL) {
151 temporarily_use_uid(pw);
152 unlink(auth_sock_name);
153 rmdir(auth_sock_dir);
154 auth_sock_name = NULL;
160 auth_input_request_forwarding(struct passwd * pw)
164 struct sockaddr_un sunaddr;
166 if (auth_sock_name != NULL) {
167 error("authentication forwarding requested twice.");
171 /* Temporarily drop privileged uid for mkdir/bind. */
172 temporarily_use_uid(pw);
174 /* Allocate a buffer for the socket name, and format the name. */
175 auth_sock_name = xmalloc(MAXPATHLEN);
176 auth_sock_dir = xmalloc(MAXPATHLEN);
177 strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
179 /* Create private directory for socket */
180 if (mkdtemp(auth_sock_dir) == NULL) {
181 packet_send_debug("Agent forwarding disabled: "
182 "mkdtemp() failed: %.100s", strerror(errno));
184 xfree(auth_sock_name);
185 xfree(auth_sock_dir);
186 auth_sock_name = NULL;
187 auth_sock_dir = NULL;
190 snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
191 auth_sock_dir, (long) getpid());
193 /* Create the socket. */
194 sock = socket(AF_UNIX, SOCK_STREAM, 0);
196 packet_disconnect("socket: %.100s", strerror(errno));
198 /* Bind it to the name. */
199 memset(&sunaddr, 0, sizeof(sunaddr));
200 sunaddr.sun_family = AF_UNIX;
201 strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
203 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0)
204 packet_disconnect("bind: %.100s", strerror(errno));
206 /* Restore the privileged uid. */
209 /* Start listening on the socket. */
210 if (listen(sock, SSH_LISTEN_BACKLOG) < 0)
211 packet_disconnect("listen: %.100s", strerror(errno));
213 /* Allocate a channel for the authentication agent socket. */
214 /* this shouldn't matter if its hpn or not - cjr */
215 nc = channel_new("auth socket",
216 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
217 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
218 0, "auth socket", 1);
219 strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
224 display_loginmsg(void)
226 if (buffer_len(&loginmsg) > 0) {
227 buffer_append(&loginmsg, "\0", 1);
228 printf("%s", (char *)buffer_ptr(&loginmsg));
229 buffer_clear(&loginmsg);
234 do_authenticated(Authctxt *authctxt)
236 setproctitle("%s", authctxt->pw->pw_name);
238 /* setup the channel layer */
239 if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
240 channel_permit_all_opens();
243 do_authenticated2(authctxt);
245 do_authenticated1(authctxt);
247 do_cleanup(authctxt);
251 * Prepares for an interactive session. This is called after the user has
252 * been successfully authenticated. During this message exchange, pseudo
253 * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
254 * are requested, etc.
257 do_authenticated1(Authctxt *authctxt)
261 int success, type, screen_flag;
262 int enable_compression_after_reply = 0;
263 u_int proto_len, data_len, dlen, compression_level = 0;
267 error("no more sessions");
270 s->authctxt = authctxt;
271 s->pw = authctxt->pw;
274 * We stay in this loop until the client requests to execute a shell
280 /* Get a packet from the client. */
281 type = packet_read();
283 /* Process the packet. */
285 case SSH_CMSG_REQUEST_COMPRESSION:
286 compression_level = packet_get_int();
288 if (compression_level < 1 || compression_level > 9) {
289 packet_send_debug("Received invalid compression level %d.",
293 if (options.compression == COMP_NONE) {
294 debug2("compression disabled");
297 /* Enable compression after we have responded with SUCCESS. */
298 enable_compression_after_reply = 1;
302 case SSH_CMSG_REQUEST_PTY:
303 success = session_pty_req(s);
306 case SSH_CMSG_X11_REQUEST_FORWARDING:
307 s->auth_proto = packet_get_string(&proto_len);
308 s->auth_data = packet_get_string(&data_len);
310 screen_flag = packet_get_protocol_flags() &
311 SSH_PROTOFLAG_SCREEN_NUMBER;
312 debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
314 if (packet_remaining() == 4) {
316 debug2("Buggy client: "
317 "X11 screen flag missing");
318 s->screen = packet_get_int();
323 success = session_setup_x11fwd(s);
325 xfree(s->auth_proto);
327 s->auth_proto = NULL;
332 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
333 if (no_agent_forwarding_flag || compat13) {
334 debug("Authentication agent forwarding not permitted for this authentication.");
337 debug("Received authentication agent forwarding request.");
338 success = auth_input_request_forwarding(s->pw);
341 case SSH_CMSG_PORT_FORWARD_REQUEST:
342 if (no_port_forwarding_flag) {
343 debug("Port forwarding not permitted for this authentication.");
346 if (!options.allow_tcp_forwarding) {
347 debug("Port forwarding not permitted.");
350 debug("Received TCP/IP port forwarding request.");
351 if (channel_input_port_forward_request(s->pw->pw_uid == 0,
352 options.gateway_ports, options.hpn_disabled,
353 options.hpn_buffer_size) < 0) {
354 debug("Port forwarding failed.");
360 case SSH_CMSG_MAX_PACKET_SIZE:
361 if (packet_set_maxsize(packet_get_int()) > 0)
365 case SSH_CMSG_EXEC_SHELL:
366 case SSH_CMSG_EXEC_CMD:
367 if (type == SSH_CMSG_EXEC_CMD) {
368 command = packet_get_string(&dlen);
369 debug("Exec command '%.500s'", command);
381 * Any unknown messages in this phase are ignored,
382 * and a failure message is returned.
384 logit("Unknown packet type received after authentication: %d", type);
386 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
390 /* Enable compression now that we have replied if appropriate. */
391 if (enable_compression_after_reply) {
392 enable_compression_after_reply = 0;
393 packet_start_compression(compression_level);
399 * This is called to fork and execute a command when we have no tty. This
400 * will call do_child from the child, and server_loop from the parent after
401 * setting up file descriptors and such.
404 do_exec_no_pty(Session *s, const char *command)
409 int pin[2], pout[2], perr[2];
410 /* Allocate pipes for communicating with the program. */
411 if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
412 packet_disconnect("Could not create pipes: %.100s",
414 #else /* USE_PIPES */
415 int inout[2], err[2];
416 /* Uses socket pairs to communicate with the program. */
417 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
418 socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
419 packet_disconnect("Could not create socket pairs: %.100s",
421 #endif /* USE_PIPES */
423 fatal("do_exec_no_pty: no session");
425 session_proctitle(s);
428 if (options.use_pam && !use_privsep)
432 /* Fork the child. */
433 if ((pid = fork()) == 0) {
436 /* Child. Reinitialize the log since the pid has changed. */
437 log_init(__progname, options.log_level, options.log_facility, log_stderr);
440 * Create a new session and process group since the 4.4BSD
441 * setlogin() affects the entire process group.
444 error("setsid failed: %.100s", strerror(errno));
448 * Redirect stdin. We close the parent side of the socket
449 * pair, and make the child side the standard input.
452 if (dup2(pin[0], 0) < 0)
453 perror("dup2 stdin");
456 /* Redirect stdout. */
458 if (dup2(pout[1], 1) < 0)
459 perror("dup2 stdout");
462 /* Redirect stderr. */
464 if (dup2(perr[1], 2) < 0)
465 perror("dup2 stderr");
467 #else /* USE_PIPES */
469 * Redirect stdin, stdout, and stderr. Stdin and stdout will
470 * use the same socket, as some programs (particularly rdist)
471 * seem to depend on it.
475 if (dup2(inout[0], 0) < 0) /* stdin */
476 perror("dup2 stdin");
477 if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
478 perror("dup2 stdout");
479 if (dup2(err[0], 2) < 0) /* stderr */
480 perror("dup2 stderr");
481 #endif /* USE_PIPES */
484 cray_init_job(s->pw); /* set up cray jid and tmpdir */
487 /* Do processing for the child (exec command etc). */
488 do_child(s, command);
492 signal(WJSIGNAL, cray_job_termination_handler);
496 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
499 packet_disconnect("fork failed: %.100s", strerror(errno));
501 /* Set interactive/non-interactive mode. */
502 packet_set_interactive(s->display != NULL);
504 /* We are the parent. Close the child sides of the pipes. */
510 if (s->is_subsystem) {
514 session_set_fds(s, pin[1], pout[0], perr[0]);
516 /* Enter the interactive session. */
517 server_loop(pid, pin[1], pout[0], perr[0]);
518 /* server_loop has closed pin[1], pout[0], and perr[0]. */
520 #else /* USE_PIPES */
521 /* We are the parent. Close the child sides of the socket pairs. */
526 * Clear loginmsg, since it's the child's responsibility to display
527 * it to the user, otherwise multiple sessions may accumulate
528 * multiple copies of the login messages.
530 buffer_clear(&loginmsg);
533 * Enter the interactive session. Note: server_loop must be able to
534 * handle the case that fdin and fdout are the same.
537 session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
539 server_loop(pid, inout[1], inout[1], err[1]);
540 /* server_loop has closed inout[1] and err[1]. */
542 #endif /* USE_PIPES */
546 * This is called to fork and execute a command when we have a tty. This
547 * will call do_child from the child, and server_loop from the parent after
548 * setting up file descriptors, controlling tty, updating wtmp, utmp,
549 * lastlog, and other such operations.
552 do_exec_pty(Session *s, const char *command)
554 int fdout, ptyfd, ttyfd, ptymaster;
558 fatal("do_exec_pty: no session");
563 if (options.use_pam) {
564 do_pam_set_tty(s->tty);
570 /* Fork the child. */
571 if ((pid = fork()) == 0) {
574 /* Child. Reinitialize the log because the pid has changed. */
575 log_init(__progname, options.log_level, options.log_facility, log_stderr);
576 /* Close the master side of the pseudo tty. */
579 /* Make the pseudo tty our controlling tty. */
580 pty_make_controlling_tty(&ttyfd, s->tty);
582 /* Redirect stdin/stdout/stderr from the pseudo tty. */
583 if (dup2(ttyfd, 0) < 0)
584 error("dup2 stdin: %s", strerror(errno));
585 if (dup2(ttyfd, 1) < 0)
586 error("dup2 stdout: %s", strerror(errno));
587 if (dup2(ttyfd, 2) < 0)
588 error("dup2 stderr: %s", strerror(errno));
590 /* Close the extra descriptor for the pseudo tty. */
593 /* record login, etc. similar to login(1) */
595 if (!(options.use_login && command == NULL)) {
597 cray_init_job(s->pw); /* set up cray jid and tmpdir */
599 do_login(s, command);
601 # ifdef LOGIN_NEEDS_UTMPX
607 /* Do common processing for the child, such as execing the command. */
608 do_child(s, command);
612 signal(WJSIGNAL, cray_job_termination_handler);
616 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
619 packet_disconnect("fork failed: %.100s", strerror(errno));
622 /* Parent. Close the slave side of the pseudo tty. */
626 * Create another descriptor of the pty master side for use as the
627 * standard input. We could use the original descriptor, but this
628 * simplifies code in server_loop. The descriptor is bidirectional.
632 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
634 /* we keep a reference to the pty master */
635 ptymaster = dup(ptyfd);
637 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
638 s->ptymaster = ptymaster;
640 /* Enter interactive session. */
641 packet_set_interactive(1);
643 session_set_fds(s, ptyfd, fdout, -1);
645 server_loop(pid, ptyfd, fdout, -1);
646 /* server_loop _has_ closed ptyfd and fdout. */
650 #ifdef LOGIN_NEEDS_UTMPX
652 do_pre_login(Session *s)
655 struct sockaddr_storage from;
656 pid_t pid = getpid();
659 * Get IP address of client. If the connection is not a socket, let
660 * the address be 0.0.0.0.
662 memset(&from, 0, sizeof(from));
663 fromlen = sizeof(from);
664 if (packet_connection_is_on_socket()) {
665 if (getpeername(packet_get_connection_in(),
666 (struct sockaddr *)&from, &fromlen) < 0) {
667 debug("getpeername: %.100s", strerror(errno));
672 record_utmp_only(pid, s->tty, s->pw->pw_name,
673 get_remote_name_or_ip(utmp_len, options.use_dns),
674 (struct sockaddr *)&from, fromlen);
679 * This is called to fork and execute a command. If another command is
680 * to be forced, execute that instead.
683 do_exec(Session *s, const char *command)
685 if (options.adm_forced_command) {
686 original_command = command;
687 command = options.adm_forced_command;
688 debug("Forced command (config) '%.900s'", command);
689 } else if (forced_command) {
690 original_command = command;
691 command = forced_command;
692 debug("Forced command (key option) '%.900s'", command);
695 #ifdef SSH_AUDIT_EVENTS
697 PRIVSEP(audit_run_command(command));
698 else if (s->ttyfd == -1) {
699 char *shell = s->pw->pw_shell;
701 if (shell[0] == '\0') /* empty shell means /bin/sh */
703 PRIVSEP(audit_run_command(shell));
708 do_exec_pty(s, command);
710 do_exec_no_pty(s, command);
712 original_command = NULL;
715 * Clear loginmsg: it's the child's responsibility to display
716 * it to the user, otherwise multiple sessions may accumulate
717 * multiple copies of the login messages.
719 buffer_clear(&loginmsg);
722 /* administrative, login(1)-like work */
724 do_login(Session *s, const char *command)
727 struct sockaddr_storage from;
728 struct passwd * pw = s->pw;
729 pid_t pid = getpid();
732 * Get IP address of client. If the connection is not a socket, let
733 * the address be 0.0.0.0.
735 memset(&from, 0, sizeof(from));
736 fromlen = sizeof(from);
737 if (packet_connection_is_on_socket()) {
738 if (getpeername(packet_get_connection_in(),
739 (struct sockaddr *) & from, &fromlen) < 0) {
740 debug("getpeername: %.100s", strerror(errno));
745 /* Record that there was a login on that tty from the remote host. */
747 record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
748 get_remote_name_or_ip(utmp_len,
750 (struct sockaddr *)&from, fromlen);
754 * If password change is needed, do it now.
755 * This needs to occur before the ~/.hushlogin check.
757 if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
760 s->authctxt->force_pwchange = 0;
761 /* XXX - signal [net] parent to enable forwardings */
765 if (check_quietlogin(s, command))
774 * Display the message of the day.
782 if (options.print_motd) {
783 #ifdef HAVE_LOGIN_CAP
784 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
787 f = fopen("/etc/motd", "r");
790 while (fgets(buf, sizeof(buf), f))
799 * Check for quiet login, either .hushlogin or command given.
802 check_quietlogin(Session *s, const char *command)
805 struct passwd *pw = s->pw;
808 /* Return 1 if .hushlogin exists or a command given. */
811 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
812 #ifdef HAVE_LOGIN_CAP
813 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
816 if (stat(buf, &st) >= 0)
823 * Sets the value of the given variable in the environment. If the variable
824 * already exists, its value is overriden.
827 child_set_env(char ***envp, u_int *envsizep, const char *name,
835 * If we're passed an uninitialized list, allocate a single null
836 * entry before continuing.
838 if (*envp == NULL && *envsizep == 0) {
839 *envp = xmalloc(sizeof(char *));
845 * Find the slot where the value should be stored. If the variable
846 * already exists, we reuse the slot; otherwise we append a new slot
847 * at the end of the array, expanding if necessary.
850 namelen = strlen(name);
851 for (i = 0; env[i]; i++)
852 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
855 /* Reuse the slot. */
858 /* New variable. Expand if necessary. */
860 if (i >= envsize - 1) {
862 fatal("child_set_env: too many env vars");
864 env = (*envp) = xrealloc(env, envsize, sizeof(char *));
867 /* Need to set the NULL pointer at end of array beyond the new slot. */
871 /* Allocate space and format the variable in the appropriate slot. */
872 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
873 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
877 * Reads environment variables from the given file and adds/overrides them
878 * into the environment. If the file does not exist, this does nothing.
879 * Otherwise, it must consist of empty lines, comments (line starts with '#')
880 * and assignments of the form name=value. No other forms are allowed.
883 read_environment_file(char ***env, u_int *envsize,
884 const char *filename)
891 f = fopen(filename, "r");
895 while (fgets(buf, sizeof(buf), f)) {
897 fatal("Too many lines in environment file %s", filename);
898 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
900 if (!*cp || *cp == '#' || *cp == '\n')
902 if (strchr(cp, '\n'))
903 *strchr(cp, '\n') = '\0';
904 value = strchr(cp, '=');
906 fprintf(stderr, "Bad line %u in %.100s\n", lineno,
911 * Replace the equals sign by nul, and advance value to
916 child_set_env(env, envsize, cp, value);
921 #ifdef HAVE_ETC_DEFAULT_LOGIN
923 * Return named variable from specified environment, or NULL if not present.
926 child_get_env(char **env, const char *name)
932 for (i=0; env[i] != NULL; i++)
933 if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
934 return(env[i] + len + 1);
939 * Read /etc/default/login.
940 * We pick up the PATH (or SUPATH for root) and UMASK.
943 read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
945 char **tmpenv = NULL, *var;
946 u_int i, tmpenvsize = 0;
950 * We don't want to copy the whole file to the child's environment,
951 * so we use a temporary environment and copy the variables we're
954 read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login");
960 var = child_get_env(tmpenv, "SUPATH");
962 var = child_get_env(tmpenv, "PATH");
964 child_set_env(env, envsize, "PATH", var);
966 if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
967 if (sscanf(var, "%5lo", &mask) == 1)
970 for (i = 0; tmpenv[i] != NULL; i++)
974 #endif /* HAVE_ETC_DEFAULT_LOGIN */
977 copy_environment(char **source, char ***env, u_int *envsize)
979 char *var_name, *var_val;
985 for(i = 0; source[i] != NULL; i++) {
986 var_name = xstrdup(source[i]);
987 if ((var_val = strstr(var_name, "=")) == NULL) {
993 debug3("Copy environment: %s=%s", var_name, var_val);
994 child_set_env(env, envsize, var_name, var_val);
1001 do_setup_env(Session *s, const char *shell)
1006 struct passwd *pw = s->pw;
1007 #ifndef HAVE_LOGIN_CAP
1011 /* Initialize the environment. */
1013 env = xcalloc(envsize, sizeof(char *));
1018 * The Windows environment contains some setting which are
1019 * important for a running system. They must not be dropped.
1024 p = fetch_windows_environment();
1025 copy_environment(p, &env, &envsize);
1026 free_windows_environment(p);
1031 /* Allow any GSSAPI methods that we've used to alter
1032 * the childs environment as they see fit
1034 ssh_gssapi_do_child(&env, &envsize);
1037 if (!options.use_login) {
1038 /* Set basic environment. */
1039 for (i = 0; i < s->num_env; i++)
1040 child_set_env(&env, &envsize, s->env[i].name,
1043 child_set_env(&env, &envsize, "USER", pw->pw_name);
1044 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1046 child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
1048 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1049 #ifdef HAVE_LOGIN_CAP
1050 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1051 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1053 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1054 #else /* HAVE_LOGIN_CAP */
1055 # ifndef HAVE_CYGWIN
1057 * There's no standard path on Windows. The path contains
1058 * important components pointing to the system directories,
1059 * needed for loading shared libraries. So the path better
1060 * remains intact here.
1062 # ifdef HAVE_ETC_DEFAULT_LOGIN
1063 read_etc_default_login(&env, &envsize, pw->pw_uid);
1064 path = child_get_env(env, "PATH");
1065 # endif /* HAVE_ETC_DEFAULT_LOGIN */
1066 if (path == NULL || *path == '\0') {
1067 child_set_env(&env, &envsize, "PATH",
1068 s->pw->pw_uid == 0 ?
1069 SUPERUSER_PATH : _PATH_STDPATH);
1071 # endif /* HAVE_CYGWIN */
1072 #endif /* HAVE_LOGIN_CAP */
1074 snprintf(buf, sizeof buf, "%.200s/%.50s",
1075 _PATH_MAILDIR, pw->pw_name);
1076 child_set_env(&env, &envsize, "MAIL", buf);
1078 /* Normal systems set SHELL by default. */
1079 child_set_env(&env, &envsize, "SHELL", shell);
1082 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1084 /* Set custom environment options from RSA authentication. */
1085 if (!options.use_login) {
1086 while (custom_environment) {
1087 struct envstring *ce = custom_environment;
1090 for (i = 0; str[i] != '=' && str[i]; i++)
1092 if (str[i] == '=') {
1094 child_set_env(&env, &envsize, str, str + i + 1);
1096 custom_environment = ce->next;
1102 /* SSH_CLIENT deprecated */
1103 snprintf(buf, sizeof buf, "%.50s %d %d",
1104 get_remote_ipaddr(), get_remote_port(), get_local_port());
1105 child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1107 laddr = get_local_ipaddr(packet_get_connection_in());
1108 snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1109 get_remote_ipaddr(), get_remote_port(), laddr, get_local_port());
1111 child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
1114 child_set_env(&env, &envsize, "SSH_TTY", s->tty);
1116 child_set_env(&env, &envsize, "TERM", s->term);
1118 child_set_env(&env, &envsize, "DISPLAY", s->display);
1119 if (original_command)
1120 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1124 if (cray_tmpdir[0] != '\0')
1125 child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
1126 #endif /* _UNICOS */
1129 * Since we clear KRB5CCNAME at startup, if it's set now then it
1130 * must have been set by a native authentication method (eg AIX or
1131 * SIA), so copy it to the child.
1136 if ((cp = getenv("KRB5CCNAME")) != NULL)
1137 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1144 if ((cp = getenv("AUTHSTATE")) != NULL)
1145 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1146 read_environment_file(&env, &envsize, "/etc/environment");
1150 if (s->authctxt->krb5_ccname)
1151 child_set_env(&env, &envsize, "KRB5CCNAME",
1152 s->authctxt->krb5_ccname);
1156 * Pull in any environment variables that may have
1159 if (options.use_pam) {
1162 p = fetch_pam_child_environment();
1163 copy_environment(p, &env, &envsize);
1164 free_pam_environment(p);
1166 p = fetch_pam_environment();
1167 copy_environment(p, &env, &envsize);
1168 free_pam_environment(p);
1170 #endif /* USE_PAM */
1172 if (auth_sock_name != NULL)
1173 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1176 /* read $HOME/.ssh/environment. */
1177 if (options.permit_user_env && !options.use_login) {
1178 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1179 strcmp(pw->pw_dir, "/") ? pw->pw_dir : "");
1180 read_environment_file(&env, &envsize, buf);
1183 /* dump the environment */
1184 fprintf(stderr, "Environment:\n");
1185 for (i = 0; env[i]; i++)
1186 fprintf(stderr, " %.200s\n", env[i]);
1192 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
1193 * first in this order).
1196 do_rc_files(Session *s, const char *shell)
1204 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1206 /* ignore _PATH_SSH_USER_RC for subsystems */
1207 if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1208 snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1209 shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1211 fprintf(stderr, "Running %s\n", cmd);
1212 f = popen(cmd, "w");
1215 fprintf(f, "%s %s\n", s->auth_proto,
1219 fprintf(stderr, "Could not run %s\n",
1221 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1223 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1224 _PATH_SSH_SYSTEM_RC);
1225 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1228 fprintf(f, "%s %s\n", s->auth_proto,
1232 fprintf(stderr, "Could not run %s\n",
1233 _PATH_SSH_SYSTEM_RC);
1234 } else if (do_xauth && options.xauth_location != NULL) {
1235 /* Add authority data to .Xauthority if appropriate. */
1238 "Running %.500s remove %.100s\n",
1239 options.xauth_location, s->auth_display);
1241 "%.500s add %.100s %.100s %.100s\n",
1242 options.xauth_location, s->auth_display,
1243 s->auth_proto, s->auth_data);
1245 snprintf(cmd, sizeof cmd, "%s -q -",
1246 options.xauth_location);
1247 f = popen(cmd, "w");
1249 fprintf(f, "remove %s\n",
1251 fprintf(f, "add %s %s %s\n",
1252 s->auth_display, s->auth_proto,
1256 fprintf(stderr, "Could not run %s\n",
1263 do_nologin(struct passwd *pw)
1268 #ifdef HAVE_LOGIN_CAP
1269 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1270 f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1271 _PATH_NOLOGIN), "r");
1274 f = fopen(_PATH_NOLOGIN, "r");
1277 /* /etc/nologin exists. Print its contents and exit. */
1278 logit("User %.100s not allowed because %s exists",
1279 pw->pw_name, _PATH_NOLOGIN);
1280 while (fgets(buf, sizeof(buf), f))
1288 /* Set login name, uid, gid, and groups. */
1290 do_setusercontext(struct passwd *pw)
1293 if (getuid() == 0 || geteuid() == 0)
1294 #endif /* HAVE_CYGWIN */
1297 #ifdef HAVE_SETPCRED
1298 if (setpcred(pw->pw_name, (char **)NULL) == -1)
1299 fatal("Failed to set process credentials");
1300 #endif /* HAVE_SETPCRED */
1301 #ifdef HAVE_LOGIN_CAP
1306 if (options.gss_authentication) {
1307 temporarily_use_uid(pw);
1308 ssh_gssapi_storecreds();
1313 if (options.use_pam) {
1317 # endif /* USE_PAM */
1318 if (setusercontext(lc, pw, pw->pw_uid,
1319 (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1320 perror("unable to set user context");
1324 # if defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
1325 /* Sets login uid for accounting */
1326 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
1327 error("setluid: %s", strerror(errno));
1328 # endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */
1330 if (setlogin(pw->pw_name) < 0)
1331 error("setlogin failed: %s", strerror(errno));
1332 if (setgid(pw->pw_gid) < 0) {
1336 /* Initialize the group list. */
1337 if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1338 perror("initgroups");
1343 if (options.gss_authentication) {
1344 temporarily_use_uid(pw);
1345 ssh_gssapi_storecreds();
1351 * PAM credentials may take the form of supplementary groups.
1352 * These will have been wiped by the above initgroups() call.
1353 * Reestablish them here.
1355 if (options.use_pam) {
1359 # endif /* USE_PAM */
1360 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
1361 irix_setusercontext(pw);
1362 # endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
1366 #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
1367 if (set_id(pw->pw_name) != 0) {
1370 #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
1371 /* Permanently switch to the desired uid. */
1372 permanently_set_uid(pw);
1379 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1380 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1383 ssh_selinux_setup_exec_context(pw->pw_name);
1388 do_pwchange(Session *s)
1391 fprintf(stderr, "WARNING: Your password has expired.\n");
1392 if (s->ttyfd != -1) {
1394 "You must change your password now and login again!\n");
1395 #ifdef PASSWD_NEEDS_USERNAME
1396 execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
1399 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1404 "Password change required but no TTY available.\n");
1410 launch_login(struct passwd *pw, const char *hostname)
1412 /* Launch login(1). */
1414 execl(LOGIN_PROGRAM, "login", "-h", hostname,
1415 #ifdef xxxLOGIN_NEEDS_TERM
1416 (s->term ? s->term : "unknown"),
1417 #endif /* LOGIN_NEEDS_TERM */
1418 #ifdef LOGIN_NO_ENDOPT
1419 "-p", "-f", pw->pw_name, (char *)NULL);
1421 "-p", "-f", "--", pw->pw_name, (char *)NULL);
1424 /* Login couldn't be executed, die. */
1431 child_close_fds(void)
1435 if (packet_get_connection_in() == packet_get_connection_out())
1436 close(packet_get_connection_in());
1438 close(packet_get_connection_in());
1439 close(packet_get_connection_out());
1442 * Close all descriptors related to channels. They will still remain
1443 * open in the parent.
1445 /* XXX better use close-on-exec? -markus */
1446 channel_close_all();
1449 * Close any extra file descriptors. Note that there may still be
1450 * descriptors left by system functions. They will be closed later.
1455 * Close any extra open file descriptors so that we don't have them
1456 * hanging around in clients. Note that we want to do this after
1457 * initgroups, because at least on Solaris 2.3 it leaves file
1460 for (i = 3; i < 64; i++)
1465 * Performs common processing for the child, such as setting up the
1466 * environment, closing extra file descriptors, setting the user and group
1467 * ids, and executing the command or shell.
1470 do_child(Session *s, const char *command)
1472 extern char **environ;
1475 const char *shell, *shell0, *hostname = NULL;
1476 struct passwd *pw = s->pw;
1478 /* remove hostkey from the child's memory */
1479 destroy_sensitive_data();
1481 /* Force a password change */
1482 if (s->authctxt->force_pwchange) {
1483 do_setusercontext(pw);
1489 /* login(1) is only called if we execute the login shell */
1490 if (options.use_login && command != NULL)
1491 options.use_login = 0;
1494 cray_setup(pw->pw_uid, pw->pw_name, command);
1495 #endif /* _UNICOS */
1498 * Login(1) does this as well, and it needs uid 0 for the "-h"
1499 * switch, so we let login(1) to this for us.
1501 if (!options.use_login) {
1503 session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
1504 if (!check_quietlogin(s, command))
1506 #else /* HAVE_OSF_SIA */
1507 /* When PAM is enabled we rely on it to do the nologin check */
1508 if (!options.use_pam)
1510 do_setusercontext(pw);
1512 * PAM session modules in do_setusercontext may have
1513 * generated messages, so if this in an interactive
1514 * login then display them too.
1516 if (!check_quietlogin(s, command))
1518 #endif /* HAVE_OSF_SIA */
1522 if (options.use_pam && !options.use_login && !is_pam_session_open()) {
1523 debug3("PAM session not opened, exiting");
1530 * Get the shell from the password data. An empty shell field is
1531 * legal, and means /bin/sh.
1533 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1536 * Make sure $SHELL points to the shell from the password file,
1537 * even if shell is overridden from login.conf
1539 env = do_setup_env(s, shell);
1541 #ifdef HAVE_LOGIN_CAP
1542 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1545 /* we have to stash the hostname before we close our socket. */
1546 if (options.use_login)
1547 hostname = get_remote_name_or_ip(utmp_len,
1550 * Close the connection descriptors; note that this is the child, and
1551 * the server will still have the socket open, and it is important
1552 * that we do not shutdown it. Note that the descriptors cannot be
1553 * closed before building the environment, as we call
1554 * get_remote_ipaddr there.
1559 * Must take new environment into use so that .ssh/rc,
1560 * /etc/ssh/sshrc and xauth are run in the proper environment.
1564 #if defined(KRB5) && defined(USE_AFS)
1566 * At this point, we check to see if AFS is active and if we have
1567 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1568 * if we can (and need to) extend the ticket into an AFS token. If
1569 * we don't do this, we run into potential problems if the user's
1570 * home directory is in AFS and it's not world-readable.
1573 if (options.kerberos_get_afs_token && k_hasafs() &&
1574 (s->authctxt->krb5_ctx != NULL)) {
1577 debug("Getting AFS token");
1581 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1582 krb5_afslog(s->authctxt->krb5_ctx,
1583 s->authctxt->krb5_fwd_ccache, cell, NULL);
1585 krb5_afslog_home(s->authctxt->krb5_ctx,
1586 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1590 /* Change current directory to the user's home directory. */
1591 if (chdir(pw->pw_dir) < 0) {
1592 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1593 pw->pw_dir, strerror(errno));
1594 #ifdef HAVE_LOGIN_CAP
1595 if (login_getcapbool(lc, "requirehome", 0))
1600 if (!options.use_login)
1601 do_rc_files(s, shell);
1603 /* restore SIGPIPE for child */
1604 signal(SIGPIPE, SIG_DFL);
1606 if (options.use_login) {
1607 launch_login(pw, hostname);
1611 /* Get the last component of the shell name. */
1612 if ((shell0 = strrchr(shell, '/')) != NULL)
1618 * If we have no command, execute the shell. In this case, the shell
1619 * name to be passed in argv[0] is preceded by '-' to indicate that
1620 * this is a login shell.
1625 /* Start the shell. Set initial character to '-'. */
1628 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1629 >= sizeof(argv0) - 1) {
1635 /* Execute the shell. */
1638 execve(shell, argv, env);
1640 /* Executing the shell failed. */
1645 * Execute the command using the user's shell. This uses the -c
1646 * option to execute the command.
1648 argv[0] = (char *) shell0;
1650 argv[2] = (char *) command;
1652 execve(shell, argv, env);
1661 static int did_init = 0;
1663 debug("session_new: init");
1664 for (i = 0; i < MAX_SESSIONS; i++) {
1665 sessions[i].used = 0;
1669 for (i = 0; i < MAX_SESSIONS; i++) {
1670 Session *s = &sessions[i];
1672 memset(s, 0, sizeof(*s));
1678 s->x11_chanids = NULL;
1679 debug("session_new: session %d", i);
1690 for (i = 0; i < MAX_SESSIONS; i++) {
1691 Session *s = &sessions[i];
1692 debug("dump: used %d session %d %p channel %d pid %ld",
1702 session_open(Authctxt *authctxt, int chanid)
1704 Session *s = session_new();
1705 debug("session_open: channel %d", chanid);
1707 error("no more sessions");
1710 s->authctxt = authctxt;
1711 s->pw = authctxt->pw;
1712 if (s->pw == NULL || !authctxt->valid)
1713 fatal("no user for session %d", s->self);
1714 debug("session_open: session %d: link with channel %d", s->self, chanid);
1720 session_by_tty(char *tty)
1723 for (i = 0; i < MAX_SESSIONS; i++) {
1724 Session *s = &sessions[i];
1725 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1726 debug("session_by_tty: session %d tty %s", i, tty);
1730 debug("session_by_tty: unknown tty %.100s", tty);
1736 session_by_channel(int id)
1739 for (i = 0; i < MAX_SESSIONS; i++) {
1740 Session *s = &sessions[i];
1741 if (s->used && s->chanid == id) {
1742 debug("session_by_channel: session %d channel %d", i, id);
1746 debug("session_by_channel: unknown channel %d", id);
1752 session_by_x11_channel(int id)
1756 for (i = 0; i < MAX_SESSIONS; i++) {
1757 Session *s = &sessions[i];
1759 if (s->x11_chanids == NULL || !s->used)
1761 for (j = 0; s->x11_chanids[j] != -1; j++) {
1762 if (s->x11_chanids[j] == id) {
1763 debug("session_by_x11_channel: session %d "
1764 "channel %d", s->self, id);
1769 debug("session_by_x11_channel: unknown channel %d", id);
1775 session_by_pid(pid_t pid)
1778 debug("session_by_pid: pid %ld", (long)pid);
1779 for (i = 0; i < MAX_SESSIONS; i++) {
1780 Session *s = &sessions[i];
1781 if (s->used && s->pid == pid)
1784 error("session_by_pid: unknown pid %ld", (long)pid);
1790 session_window_change_req(Session *s)
1792 s->col = packet_get_int();
1793 s->row = packet_get_int();
1794 s->xpixel = packet_get_int();
1795 s->ypixel = packet_get_int();
1797 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1802 session_pty_req(Session *s)
1808 debug("Allocating a pty not permitted for this authentication.");
1811 if (s->ttyfd != -1) {
1812 packet_disconnect("Protocol error: you already have a pty.");
1816 s->term = packet_get_string(&len);
1819 s->col = packet_get_int();
1820 s->row = packet_get_int();
1822 s->row = packet_get_int();
1823 s->col = packet_get_int();
1825 s->xpixel = packet_get_int();
1826 s->ypixel = packet_get_int();
1828 if (strcmp(s->term, "") == 0) {
1833 /* Allocate a pty and open it. */
1834 debug("Allocating pty.");
1835 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1841 error("session_pty_req: session %d alloc failed", s->self);
1844 debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1846 /* for SSH1 the tty modes length is not given */
1848 n_bytes = packet_remaining();
1849 tty_parse_modes(s->ttyfd, &n_bytes);
1852 pty_setowner(s->pw, s->tty);
1854 /* Set window size from the packet. */
1855 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1858 session_proctitle(s);
1863 session_subsystem_req(Session *s)
1868 char *prog, *cmd, *subsys = packet_get_string(&len);
1872 logit("subsystem request for %.100s", subsys);
1874 for (i = 0; i < options.num_subsystems; i++) {
1875 if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1876 prog = options.subsystem_command[i];
1877 cmd = options.subsystem_args[i];
1878 if (stat(prog, &st) < 0) {
1879 error("subsystem: cannot stat %s: %s", prog,
1883 debug("subsystem: exec() %s", cmd);
1884 s->is_subsystem = 1;
1892 logit("subsystem request for %.100s failed, subsystem not found",
1900 session_x11_req(Session *s)
1904 if (s->auth_proto != NULL || s->auth_data != NULL) {
1905 error("session_x11_req: session %d: "
1906 "x11 forwarding already active", s->self);
1909 s->single_connection = packet_get_char();
1910 s->auth_proto = packet_get_string(NULL);
1911 s->auth_data = packet_get_string(NULL);
1912 s->screen = packet_get_int();
1915 success = session_setup_x11fwd(s);
1917 xfree(s->auth_proto);
1918 xfree(s->auth_data);
1919 s->auth_proto = NULL;
1920 s->auth_data = NULL;
1926 session_shell_req(Session *s)
1934 session_exec_req(Session *s)
1937 char *command = packet_get_string(&len);
1939 do_exec(s, command);
1945 session_break_req(Session *s)
1948 packet_get_int(); /* ignored */
1951 if (s->ttyfd == -1 ||
1952 tcsendbreak(s->ttyfd, 0) < 0)
1958 session_env_req(Session *s)
1961 u_int name_len, val_len, i;
1963 name = packet_get_string(&name_len);
1964 val = packet_get_string(&val_len);
1967 /* Don't set too many environment variables */
1968 if (s->num_env > 128) {
1969 debug2("Ignoring env request %s: too many env vars", name);
1973 for (i = 0; i < options.num_accept_env; i++) {
1974 if (match_pattern(name, options.accept_env[i])) {
1975 debug2("Setting env %d: %s=%s", s->num_env, name, val);
1976 s->env = xrealloc(s->env, s->num_env + 1,
1978 s->env[s->num_env].name = name;
1979 s->env[s->num_env].val = val;
1984 debug2("Ignoring env request %s: disallowed name", name);
1993 session_auth_agent_req(Session *s)
1995 static int called = 0;
1997 if (no_agent_forwarding_flag) {
1998 debug("session_auth_agent_req: no_agent_forwarding_flag");
2005 return auth_input_request_forwarding(s->pw);
2010 session_input_channel_req(Channel *c, const char *rtype)
2015 if ((s = session_by_channel(c->self)) == NULL) {
2016 logit("session_input_channel_req: no session %d req %.100s",
2020 debug("session_input_channel_req: session %d req %s", s->self, rtype);
2023 * a session is in LARVAL state until a shell, a command
2024 * or a subsystem is executed
2026 if (c->type == SSH_CHANNEL_LARVAL) {
2027 if (strcmp(rtype, "shell") == 0) {
2028 success = session_shell_req(s);
2029 } else if (strcmp(rtype, "exec") == 0) {
2030 success = session_exec_req(s);
2031 } else if (strcmp(rtype, "pty-req") == 0) {
2032 success = session_pty_req(s);
2033 } else if (strcmp(rtype, "x11-req") == 0) {
2034 success = session_x11_req(s);
2035 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
2036 success = session_auth_agent_req(s);
2037 } else if (strcmp(rtype, "subsystem") == 0) {
2038 success = session_subsystem_req(s);
2039 } else if (strcmp(rtype, "env") == 0) {
2040 success = session_env_req(s);
2043 if (strcmp(rtype, "window-change") == 0) {
2044 success = session_window_change_req(s);
2045 } else if (strcmp(rtype, "break") == 0) {
2046 success = session_break_req(s);
2053 session_set_fds(Session *s, int fdin, int fdout, int fderr)
2056 fatal("session_set_fds: called for proto != 2.0");
2058 * now that have a child and a pipe to the child,
2059 * we can activate our channel and register the fd's
2061 if (s->chanid == -1)
2062 fatal("no channel for session %d", s->self);
2063 if(options.hpn_disabled)
2064 channel_set_fds(s->chanid,
2066 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2068 CHAN_SES_WINDOW_DEFAULT);
2070 channel_set_fds(s->chanid,
2072 fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
2074 options.hpn_buffer_size);
2078 * Function to perform pty cleanup. Also called if we get aborted abnormally
2079 * (e.g., due to a dropped connection).
2082 session_pty_cleanup2(Session *s)
2085 error("session_pty_cleanup: no session");
2091 debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
2093 /* Record that the user has logged out. */
2095 record_logout(s->pid, s->tty, s->pw->pw_name);
2097 /* Release the pseudo-tty. */
2099 pty_release(s->tty);
2102 * Close the server side of the socket pairs. We must do this after
2103 * the pty cleanup, so that another process doesn't get this pty
2104 * while we're still cleaning up.
2106 if (close(s->ptymaster) < 0)
2107 error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
2109 /* unlink pty from session */
2114 session_pty_cleanup(Session *s)
2116 PRIVSEP(session_pty_cleanup2(s));
2122 #define SSH_SIG(x) if (sig == SIG ## x) return #x
2137 return "SIG@openssh.com";
2141 session_close_x11(int id)
2145 if ((c = channel_by_id(id)) == NULL) {
2146 debug("session_close_x11: x11 channel %d missing", id);
2148 /* Detach X11 listener */
2149 debug("session_close_x11: detach x11 channel %d", id);
2150 channel_cancel_cleanup(id);
2151 if (c->ostate != CHAN_OUTPUT_CLOSED)
2157 session_close_single_x11(int id, void *arg)
2162 debug3("session_close_single_x11: channel %d", id);
2163 channel_cancel_cleanup(id);
2164 if ((s = session_by_x11_channel(id)) == NULL)
2165 fatal("session_close_single_x11: no x11 channel %d", id);
2166 for (i = 0; s->x11_chanids[i] != -1; i++) {
2167 debug("session_close_single_x11: session %d: "
2168 "closing channel %d", s->self, s->x11_chanids[i]);
2170 * The channel "id" is already closing, but make sure we
2171 * close all of its siblings.
2173 if (s->x11_chanids[i] != id)
2174 session_close_x11(s->x11_chanids[i]);
2176 xfree(s->x11_chanids);
2177 s->x11_chanids = NULL;
2182 if (s->auth_proto) {
2183 xfree(s->auth_proto);
2184 s->auth_proto = NULL;
2187 xfree(s->auth_data);
2188 s->auth_data = NULL;
2190 if (s->auth_display) {
2191 xfree(s->auth_display);
2192 s->auth_display = NULL;
2197 session_exit_message(Session *s, int status)
2201 if ((c = channel_lookup(s->chanid)) == NULL)
2202 fatal("session_exit_message: session %d: no channel %d",
2203 s->self, s->chanid);
2204 debug("session_exit_message: session %d channel %d pid %ld",
2205 s->self, s->chanid, (long)s->pid);
2207 if (WIFEXITED(status)) {
2208 channel_request_start(s->chanid, "exit-status", 0);
2209 packet_put_int(WEXITSTATUS(status));
2211 } else if (WIFSIGNALED(status)) {
2212 channel_request_start(s->chanid, "exit-signal", 0);
2213 packet_put_cstring(sig2name(WTERMSIG(status)));
2215 packet_put_char(WCOREDUMP(status));
2216 #else /* WCOREDUMP */
2218 #endif /* WCOREDUMP */
2219 packet_put_cstring("");
2220 packet_put_cstring("");
2223 /* Some weird exit cause. Just exit. */
2224 packet_disconnect("wait returned status %04x.", status);
2227 /* disconnect channel */
2228 debug("session_exit_message: release channel %d", s->chanid);
2231 * Adjust cleanup callback attachment to send close messages when
2232 * the channel gets EOF. The session will be then be closed
2233 * by session_close_by_channel when the childs close their fds.
2235 channel_register_cleanup(c->self, session_close_by_channel, 1);
2238 * emulate a write failure with 'chan_write_failed', nobody will be
2239 * interested in data we write.
2240 * Note that we must not call 'chan_read_failed', since there could
2241 * be some more data waiting in the pipe.
2243 if (c->ostate != CHAN_OUTPUT_CLOSED)
2244 chan_write_failed(c);
2248 session_close(Session *s)
2252 debug("session_close: session %d pid %ld", s->self, (long)s->pid);
2254 session_pty_cleanup(s);
2260 xfree(s->x11_chanids);
2261 if (s->auth_display)
2262 xfree(s->auth_display);
2264 xfree(s->auth_data);
2266 xfree(s->auth_proto);
2268 if (s->env != NULL) {
2269 for (i = 0; i < s->num_env; i++) {
2270 xfree(s->env[i].name);
2271 xfree(s->env[i].val);
2275 session_proctitle(s);
2279 session_close_by_pid(pid_t pid, int status)
2281 Session *s = session_by_pid(pid);
2283 debug("session_close_by_pid: no session for pid %ld",
2287 if (s->chanid != -1)
2288 session_exit_message(s, status);
2290 session_pty_cleanup(s);
2295 * this is called when a channel dies before
2296 * the session 'child' itself dies
2299 session_close_by_channel(int id, void *arg)
2301 Session *s = session_by_channel(id);
2305 debug("session_close_by_channel: no session for id %d", id);
2308 debug("session_close_by_channel: channel %d child %ld",
2311 debug("session_close_by_channel: channel %d: has child", id);
2313 * delay detach of session, but release pty, since
2314 * the fd's to the child are already closed
2317 session_pty_cleanup(s);
2320 /* detach by removing callback */
2321 channel_cancel_cleanup(s->chanid);
2323 /* Close any X11 listeners associated with this session */
2324 if (s->x11_chanids != NULL) {
2325 for (i = 0; s->x11_chanids[i] != -1; i++) {
2326 session_close_x11(s->x11_chanids[i]);
2327 s->x11_chanids[i] = -1;
2336 session_destroy_all(void (*closefunc)(Session *))
2339 for (i = 0; i < MAX_SESSIONS; i++) {
2340 Session *s = &sessions[i];
2342 if (closefunc != NULL)
2351 session_tty_list(void)
2353 static char buf[1024];
2358 for (i = 0; i < MAX_SESSIONS; i++) {
2359 Session *s = &sessions[i];
2360 if (s->used && s->ttyfd != -1) {
2362 if (strncmp(s->tty, "/dev/", 5) != 0) {
2363 cp = strrchr(s->tty, '/');
2364 cp = (cp == NULL) ? s->tty : cp + 1;
2369 strlcat(buf, ",", sizeof buf);
2370 strlcat(buf, cp, sizeof buf);
2374 strlcpy(buf, "notty", sizeof buf);
2379 session_proctitle(Session *s)
2382 error("no user for session %d", s->self);
2384 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2388 session_setup_x11fwd(Session *s)
2391 char display[512], auth_display[512];
2392 char hostname[MAXHOSTNAMELEN];
2395 if (no_x11_forwarding_flag) {
2396 packet_send_debug("X11 forwarding disabled in user configuration file.");
2399 if (!options.x11_forwarding) {
2400 debug("X11 forwarding disabled in server configuration file.");
2403 if (!options.xauth_location ||
2404 (stat(options.xauth_location, &st) == -1)) {
2405 packet_send_debug("No xauth program; cannot forward with spoofing.");
2408 if (options.use_login) {
2409 packet_send_debug("X11 forwarding disabled; "
2410 "not compatible with UseLogin=yes.");
2413 if (s->display != NULL) {
2414 debug("X11 display already set.");
2417 if (x11_create_display_inet(options.x11_display_offset,
2418 options.x11_use_localhost, s->single_connection,
2419 &s->display_number, &s->x11_chanids,
2420 options.hpn_disabled, options.hpn_buffer_size) == -1) {
2421 debug("x11_create_display_inet failed.");
2424 for (i = 0; s->x11_chanids[i] != -1; i++) {
2425 channel_register_cleanup(s->x11_chanids[i],
2426 session_close_single_x11, 0);
2429 /* Set up a suitable value for the DISPLAY variable. */
2430 if (gethostname(hostname, sizeof(hostname)) < 0)
2431 fatal("gethostname: %.100s", strerror(errno));
2433 * auth_display must be used as the displayname when the
2434 * authorization entry is added with xauth(1). This will be
2435 * different than the DISPLAY string for localhost displays.
2437 if (options.x11_use_localhost) {
2438 snprintf(display, sizeof display, "localhost:%u.%u",
2439 s->display_number, s->screen);
2440 snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2441 s->display_number, s->screen);
2442 s->display = xstrdup(display);
2443 s->auth_display = xstrdup(auth_display);
2445 #ifdef IPADDR_IN_DISPLAY
2447 struct in_addr my_addr;
2449 he = gethostbyname(hostname);
2451 error("Can't get IP address for X11 DISPLAY.");
2452 packet_send_debug("Can't get IP address for X11 DISPLAY.");
2455 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2456 snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
2457 s->display_number, s->screen);
2459 snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2460 s->display_number, s->screen);
2462 s->display = xstrdup(display);
2463 s->auth_display = xstrdup(display);
2470 do_authenticated2(Authctxt *authctxt)
2472 server_loop2(authctxt);
2476 do_cleanup(Authctxt *authctxt)
2478 static int called = 0;
2480 debug("do_cleanup");
2482 /* no cleanup if we're in the child for login shell */
2486 /* avoid double cleanup */
2491 if (authctxt == NULL || !authctxt->authenticated)
2494 if (options.kerberos_ticket_cleanup &&
2496 krb5_cleanup_proc(authctxt);
2500 if (compat20 && options.gss_cleanup_creds)
2501 ssh_gssapi_cleanup_creds();
2505 if (options.use_pam) {
2507 sshpam_thread_cleanup();
2511 /* remove agent socket */
2512 auth_sock_cleanup_proc(authctxt->pw);
2515 * Cleanup ptys/utmp only if privsep is disabled,
2516 * or if running in monitor.
2518 if (!use_privsep || mm_is_monitor())
2519 session_destroy_all(session_pty_cleanup2);