]> andersk Git - gssapi-openssh.git/blobdiff - openssh/session.c
Import of OpenSSH 4.6p1
[gssapi-openssh.git] / openssh / session.c
index b32c9e2ca52393cce693799e569330afe23d7a86..4c97c4a7dddd39bb08a163c688857ae1eae3164e 100644 (file)
@@ -1,3 +1,4 @@
+/* $OpenBSD: session.c,v 1.221 2007/01/21 01:41:54 stevesk Exp $ */
 /*
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
  *                    All rights reserved
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: session.c,v 1.181 2004/12/23 17:35:48 markus Exp $");
 
+#include <sys/types.h>
+#include <sys/param.h>
+#ifdef HAVE_SYS_STAT_H
+# include <sys/stat.h>
+#endif
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/wait.h>
+
+#include <arpa/inet.h>
+
+#include <errno.h>
+#include <grp.h>
+#ifdef HAVE_PATHS_H
+#include <paths.h>
+#endif
+#include <pwd.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "xmalloc.h"
 #include "ssh.h"
 #include "ssh1.h"
 #include "ssh2.h"
-#include "xmalloc.h"
 #include "sshpty.h"
 #include "packet.h"
 #include "buffer.h"
@@ -46,7 +70,12 @@ RCSID("$OpenBSD: session.c,v 1.181 2004/12/23 17:35:48 markus Exp $");
 #include "uidswap.h"
 #include "compat.h"
 #include "channels.h"
-#include "bufaux.h"
+#include "key.h"
+#include "cipher.h"
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+#include "hostfile.h"
 #include "auth.h"
 #include "auth-options.h"
 #include "pathnames.h"
@@ -56,16 +85,13 @@ RCSID("$OpenBSD: session.c,v 1.181 2004/12/23 17:35:48 markus Exp $");
 #include "serverloop.h"
 #include "canohost.h"
 #include "session.h"
+#include "kex.h"
 #include "monitor_wrap.h"
 
 #if defined(KRB5) && defined(USE_AFS)
 #include <kafs.h>
 #endif
 
-#ifdef GSSAPI
-#include "ssh-gss.h"
-#endif
-
 /* func */
 
 Session *session_new(void);
@@ -174,7 +200,7 @@ auth_input_request_forwarding(struct passwd * pw)
        sunaddr.sun_family = AF_UNIX;
        strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
 
-       if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
+       if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0)
                packet_disconnect("bind: %.100s", strerror(errno));
 
        /* Restore the privileged uid. */
@@ -196,11 +222,11 @@ auth_input_request_forwarding(struct passwd * pw)
 static void
 display_loginmsg(void)
 {
-        if (buffer_len(&loginmsg) > 0) {
-                buffer_append(&loginmsg, "\0", 1);
-                printf("%s", (char *)buffer_ptr(&loginmsg));
-                buffer_clear(&loginmsg);
-        }
+       if (buffer_len(&loginmsg) > 0) {
+               buffer_append(&loginmsg, "\0", 1);
+               printf("%s", (char *)buffer_ptr(&loginmsg));
+               buffer_clear(&loginmsg);
+       }
 }
 
 void
@@ -208,15 +234,6 @@ do_authenticated(Authctxt *authctxt)
 {
        setproctitle("%s", authctxt->pw->pw_name);
 
-       /*
-        * Cancel the alarm we set to limit the time taken for
-        * authentication.
-        */
-       alarm(0);
-       if (startup_pipe != -1) {
-               close(startup_pipe);
-               startup_pipe = -1;
-       }
        /* setup the channel layer */
        if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
                channel_permit_all_opens();
@@ -272,7 +289,7 @@ do_authenticated1(Authctxt *authctxt)
                                    compression_level);
                                break;
                        }
-                       if (!options.compression) {
+                       if (options.compression == COMP_NONE) {
                                debug2("compression disabled");
                                break;
                        }
@@ -330,7 +347,11 @@ do_authenticated1(Authctxt *authctxt)
                                break;
                        }
                        debug("Received TCP/IP port forwarding request.");
-                       channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
+                       if (channel_input_port_forward_request(s->pw->pw_uid == 0,
+                           options.gateway_ports) < 0) {
+                               debug("Port forwarding failed.");
+                               break;
+                       }
                        success = 1;
                        break;
 
@@ -640,7 +661,7 @@ do_pre_login(Session *s)
        fromlen = sizeof(from);
        if (packet_connection_is_on_socket()) {
                if (getpeername(packet_get_connection_in(),
-                   (struct sockaddr *) & from, &fromlen) < 0) {
+                   (struct sockaddr *)&from, &fromlen) < 0) {
                        debug("getpeername: %.100s", strerror(errno));
                        cleanup_exit(255);
                }
@@ -659,10 +680,14 @@ do_pre_login(Session *s)
 void
 do_exec(Session *s, const char *command)
 {
-       if (forced_command) {
+       if (options.adm_forced_command) {
+               original_command = command;
+               command = options.adm_forced_command;
+               debug("Forced command (config) '%.900s'", command);
+       } else if (forced_command) {
                original_command = command;
                command = forced_command;
-               debug("Forced command '%.900s'", command);
+               debug("Forced command (key option) '%.900s'", command);
        }
 
 #ifdef SSH_AUDIT_EVENTS
@@ -834,7 +859,7 @@ child_set_env(char ***envp, u_int *envsizep, const char *name,
                        if (envsize >= 1000)
                                fatal("child_set_env: too many env vars");
                        envsize += 50;
-                       env = (*envp) = xrealloc(env, envsize * sizeof(char *));
+                       env = (*envp) = xrealloc(env, envsize, sizeof(char *));
                        *envsizep = envsize;
                }
                /* Need to set the NULL pointer at end of array beyond the new slot. */
@@ -946,7 +971,8 @@ read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
 }
 #endif /* HAVE_ETC_DEFAULT_LOGIN */
 
-void copy_environment(char **source, char ***env, u_int *envsize)
+void
+copy_environment(char **source, char ***env, u_int *envsize)
 {
        char *var_name, *var_val;
        int i;
@@ -974,12 +1000,15 @@ do_setup_env(Session *s, const char *shell)
 {
        char buf[256];
        u_int i, envsize;
-       char **env, *laddr, *path = NULL;
+       char **env, *laddr;
        struct passwd *pw = s->pw;
+#ifndef HAVE_LOGIN_CAP
+       char *path = NULL;
+#endif
 
        /* Initialize the environment. */
        envsize = 100;
-       env = xmalloc(envsize * sizeof(char *));
+       env = xcalloc(envsize, sizeof(char *));
        env[0] = NULL;
 
 #ifdef HAVE_CYGWIN
@@ -1332,6 +1361,11 @@ do_setusercontext(struct passwd *pw)
 # ifdef _AIX
                aix_usrinfo(pw);
 # endif /* _AIX */
+#if defined(HAVE_LIBIAF)  &&  !defined(BROKEN_LIBIAF)
+               if (set_id(pw->pw_name) != 0) {
+                       exit(1);
+               }
+#endif /* HAVE_LIBIAF  && !BROKEN_LIBIAF */
                /* Permanently switch to the desired uid. */
                permanently_set_uid(pw);
 #endif
@@ -1342,6 +1376,10 @@ do_setusercontext(struct passwd *pw)
 #endif
        if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
                fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
+
+#ifdef WITH_SELINUX
+       ssh_selinux_setup_exec_context(pw->pw_name);
+#endif
 }
 
 static void
@@ -1412,7 +1450,7 @@ child_close_fds(void)
        endpwent();
 
        /*
-        * Close any extra open file descriptors so that we don\'t have them
+        * Close any extra open file descriptors so that we don't have them
         * hanging around in clients.  Note that we want to do this after
         * initgroups, because at least on Solaris 2.3 it leaves file
         * descriptors open.
@@ -1464,7 +1502,9 @@ do_child(Session *s, const char *command)
                if (!check_quietlogin(s, command))
                        do_motd();
 #else /* HAVE_OSF_SIA */
-               do_nologin(pw);
+               /* When PAM is enabled we rely on it to do the nologin check */
+               if (!options.use_pam)
+                       do_nologin(pw);
                do_setusercontext(pw);
                /*
                 * PAM session modules in do_setusercontext may have
@@ -1477,7 +1517,8 @@ do_child(Session *s, const char *command)
        }
 
 #ifdef USE_PAM
-       if (options.use_pam && !is_pam_session_open()) {
+       if (options.use_pam && !options.use_login && !is_pam_session_open()) {
+               debug3("PAM session not opened, exiting");
                display_loginmsg();
                exit(254);
        }
@@ -1528,7 +1569,7 @@ do_child(Session *s, const char *command)
         */
 
        if (options.kerberos_get_afs_token && k_hasafs() &&
-            (s->authctxt->krb5_ctx != NULL)) {
+           (s->authctxt->krb5_ctx != NULL)) {
                char cell[64];
 
                debug("Getting AFS token");
@@ -1544,7 +1585,7 @@ do_child(Session *s, const char *command)
        }
 #endif
 
-       /* Change current directory to the user\'s home directory. */
+       /* Change current directory to the user's home directory. */
        if (chdir(pw->pw_dir) < 0) {
                fprintf(stderr, "Could not chdir to home directory %s: %s\n",
                    pw->pw_dir, strerror(errno));
@@ -1558,7 +1599,7 @@ do_child(Session *s, const char *command)
                do_rc_files(s, shell);
 
        /* restore SIGPIPE for child */
-       signal(SIGPIPE,  SIG_DFL);
+       signal(SIGPIPE, SIG_DFL);
 
        if (options.use_login) {
                launch_login(pw, hostname);
@@ -1632,6 +1673,7 @@ session_new(void)
                        s->ttyfd = -1;
                        s->used = 1;
                        s->self = i;
+                       s->x11_chanids = NULL;
                        debug("session_new: session %d", i);
                        return s;
                }
@@ -1704,6 +1746,29 @@ session_by_channel(int id)
        return NULL;
 }
 
+static Session *
+session_by_x11_channel(int id)
+{
+       int i, j;
+
+       for (i = 0; i < MAX_SESSIONS; i++) {
+               Session *s = &sessions[i];
+
+               if (s->x11_chanids == NULL || !s->used)
+                       continue;
+               for (j = 0; s->x11_chanids[j] != -1; j++) {
+                       if (s->x11_chanids[j] == id) {
+                               debug("session_by_x11_channel: session %d "
+                                   "channel %d", s->self, id);
+                               return s;
+                       }
+               }
+       }
+       debug("session_by_x11_channel: unknown channel %d", id);
+       session_dump();
+       return NULL;
+}
+
 static Session *
 session_by_pid(pid_t pid)
 {
@@ -1798,17 +1863,18 @@ session_subsystem_req(Session *s)
        struct stat st;
        u_int len;
        int success = 0;
-       char *cmd, *subsys = packet_get_string(&len);
-       int i;
+       char *prog, *cmd, *subsys = packet_get_string(&len);
+       u_int i;
 
        packet_check_eom();
        logit("subsystem request for %.100s", subsys);
 
        for (i = 0; i < options.num_subsystems; i++) {
                if (strcmp(subsys, options.subsystem_name[i]) == 0) {
-                       cmd = options.subsystem_command[i];
-                       if (stat(cmd, &st) < 0) {
-                               error("subsystem: cannot stat %s: %s", cmd,
+                       prog = options.subsystem_command[i];
+                       cmd = options.subsystem_args[i];
+                       if (stat(prog, &st) < 0) {
+                               error("subsystem: cannot stat %s: %s", prog,
                                    strerror(errno));
                                break;
                        }
@@ -1833,6 +1899,11 @@ session_x11_req(Session *s)
 {
        int success;
 
+       if (s->auth_proto != NULL || s->auth_data != NULL) {
+               error("session_x11_req: session %d: "
+                   "x11 forwarding already active", s->self);
+               return 0;
+       }
        s->single_connection = packet_get_char();
        s->auth_proto = packet_get_string(NULL);
        s->auth_data = packet_get_string(NULL);
@@ -1900,8 +1971,8 @@ session_env_req(Session *s)
        for (i = 0; i < options.num_accept_env; i++) {
                if (match_pattern(name, options.accept_env[i])) {
                        debug2("Setting env %d: %s=%s", s->num_env, name, val);
-                       s->env = xrealloc(s->env, sizeof(*s->env) *
-                           (s->num_env + 1));
+                       s->env = xrealloc(s->env, s->num_env + 1,
+                           sizeof(*s->env));
                        s->env[s->num_env].name = name;
                        s->env[s->num_env].val = val;
                        s->num_env++;
@@ -1956,7 +2027,7 @@ session_input_channel_req(Channel *c, const char *rtype)
                } else if (strcmp(rtype, "exec") == 0) {
                        success = session_exec_req(s);
                } else if (strcmp(rtype, "pty-req") == 0) {
-                       success =  session_pty_req(s);
+                       success = session_pty_req(s);
                } else if (strcmp(rtype, "x11-req") == 0) {
                        success = session_x11_req(s);
                } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
@@ -2057,6 +2128,62 @@ sig2name(int sig)
        return "SIG@openssh.com";
 }
 
+static void
+session_close_x11(int id)
+{
+       Channel *c;
+
+       if ((c = channel_by_id(id)) == NULL) {
+               debug("session_close_x11: x11 channel %d missing", id);
+       } else {
+               /* Detach X11 listener */
+               debug("session_close_x11: detach x11 channel %d", id);
+               channel_cancel_cleanup(id);
+               if (c->ostate != CHAN_OUTPUT_CLOSED)
+                       chan_mark_dead(c);
+       }
+}
+
+static void
+session_close_single_x11(int id, void *arg)
+{
+       Session *s;
+       u_int i;
+
+       debug3("session_close_single_x11: channel %d", id);
+       channel_cancel_cleanup(id);
+       if ((s = session_by_x11_channel(id)) == NULL)
+               fatal("session_close_single_x11: no x11 channel %d", id);
+       for (i = 0; s->x11_chanids[i] != -1; i++) {
+               debug("session_close_single_x11: session %d: "
+                   "closing channel %d", s->self, s->x11_chanids[i]);
+               /*
+                * The channel "id" is already closing, but make sure we
+                * close all of its siblings.
+                */
+               if (s->x11_chanids[i] != id)
+                       session_close_x11(s->x11_chanids[i]);
+       }
+       xfree(s->x11_chanids);
+       s->x11_chanids = NULL;
+       if (s->display) {
+               xfree(s->display);
+               s->display = NULL;
+       }
+       if (s->auth_proto) {
+               xfree(s->auth_proto);
+               s->auth_proto = NULL;
+       }
+       if (s->auth_data) {
+               xfree(s->auth_data);
+               s->auth_data = NULL;
+       }
+       if (s->auth_display) {
+               xfree(s->auth_display);
+               s->auth_display = NULL;
+       }
+}
+
 static void
 session_exit_message(Session *s, int status)
 {
@@ -2090,7 +2217,14 @@ session_exit_message(Session *s, int status)
 
        /* disconnect channel */
        debug("session_exit_message: release channel %d", s->chanid);
-       channel_cancel_cleanup(s->chanid);
+
+       /*
+        * Adjust cleanup callback attachment to send close messages when
+        * the channel gets EOF. The session will be then be closed
+        * by session_close_by_channel when the childs close their fds.
+        */
+       channel_register_cleanup(c->self, session_close_by_channel, 1);
+
        /*
         * emulate a write failure with 'chan_write_failed', nobody will be
         * interested in data we write.
@@ -2099,13 +2233,12 @@ session_exit_message(Session *s, int status)
         */
        if (c->ostate != CHAN_OUTPUT_CLOSED)
                chan_write_failed(c);
-       s->chanid = -1;
 }
 
 void
 session_close(Session *s)
 {
-       int i;
+       u_int i;
 
        debug("session_close: session %d pid %ld", s->self, (long)s->pid);
        if (s->ttyfd != -1)
@@ -2114,6 +2247,8 @@ session_close(Session *s)
                xfree(s->term);
        if (s->display)
                xfree(s->display);
+       if (s->x11_chanids)
+               xfree(s->x11_chanids);
        if (s->auth_display)
                xfree(s->auth_display);
        if (s->auth_data)
@@ -2121,12 +2256,13 @@ session_close(Session *s)
        if (s->auth_proto)
                xfree(s->auth_proto);
        s->used = 0;
-       for (i = 0; i < s->num_env; i++) {
-               xfree(s->env[i].name);
-               xfree(s->env[i].val);
-       }
-       if (s->env != NULL)
+       if (s->env != NULL) {
+               for (i = 0; i < s->num_env; i++) {
+                       xfree(s->env[i].name);
+                       xfree(s->env[i].val);
+               }
                xfree(s->env);
+       }
        session_proctitle(s);
 }
 
@@ -2141,7 +2277,9 @@ session_close_by_pid(pid_t pid, int status)
        }
        if (s->chanid != -1)
                session_exit_message(s, status);
-       session_close(s);
+       if (s->ttyfd != -1)
+               session_pty_cleanup(s);
+       s->pid = 0;
 }
 
 /*
@@ -2152,6 +2290,8 @@ void
 session_close_by_channel(int id, void *arg)
 {
        Session *s = session_by_channel(id);
+       u_int i;
+
        if (s == NULL) {
                debug("session_close_by_channel: no session for id %d", id);
                return;
@@ -2170,6 +2310,15 @@ session_close_by_channel(int id, void *arg)
        }
        /* detach by removing callback */
        channel_cancel_cleanup(s->chanid);
+
+       /* Close any X11 listeners associated with this session */
+       if (s->x11_chanids != NULL) {
+               for (i = 0; s->x11_chanids[i] != -1; i++) {
+                       session_close_x11(s->x11_chanids[i]);
+                       s->x11_chanids[i] = -1;
+               }
+       }
+
        s->chanid = -1;
        session_close(s);
 }
@@ -2232,6 +2381,7 @@ session_setup_x11fwd(Session *s)
        struct stat st;
        char display[512], auth_display[512];
        char hostname[MAXHOSTNAMELEN];
+       u_int i;
 
        if (no_x11_forwarding_flag) {
                packet_send_debug("X11 forwarding disabled in user configuration file.");
@@ -2257,10 +2407,14 @@ session_setup_x11fwd(Session *s)
        }
        if (x11_create_display_inet(options.x11_display_offset,
            options.x11_use_localhost, s->single_connection,
-           &s->display_number) == -1) {
+           &s->display_number, &s->x11_chanids) == -1) {
                debug("x11_create_display_inet failed.");
                return 0;
        }
+       for (i = 0; s->x11_chanids[i] != -1; i++) {
+               channel_register_cleanup(s->x11_chanids[i],
+                   session_close_single_x11, 0);
+       }
 
        /* Set up a suitable value for the DISPLAY variable. */
        if (gethostname(hostname, sizeof(hostname)) < 0)
@@ -2324,7 +2478,7 @@ do_cleanup(Authctxt *authctxt)
                return;
        called = 1;
 
-       if (authctxt == NULL)
+       if (authctxt == NULL || !authctxt->authenticated)
                return;
 #ifdef KRB5
        if (options.kerberos_ticket_cleanup &&
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