- djm@cvs.openbsd.org 2010/01/30 02:54:53

[openssh.git] / session.c

diff --git a/session.c b/session.c
index f04266f788d97d11c6c673c9dac607096e42154c..fd7acbe03bb1751b89748da23b2d342bd6925c1a 100644 (file)
--- a/session.c
+++ b/session.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: session.c,v 1.246 2009/04/17 19:23:06 stevesk Exp $ */
+/* $OpenBSD: session.c,v 1.251 2010/01/12 08:33:17 dtucker Exp $ */
 /*
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
  *                    All rights reserved
@@ -142,9 +142,10 @@ static int sessions_first_unused = -1;
 static int sessions_nalloc = 0;
 static Session *sessions = NULL;
 
-#define SUBSYSTEM_NONE         0
-#define SUBSYSTEM_EXT          1
-#define SUBSYSTEM_INT_SFTP     2
+#define SUBSYSTEM_NONE                 0
+#define SUBSYSTEM_EXT                  1
+#define SUBSYSTEM_INT_SFTP             2
+#define SUBSYSTEM_INT_SFTP_ERROR       3
 
 #ifdef HAVE_LOGIN_CAP
 login_cap_t *lc;
@@ -715,8 +716,8 @@ do_exec_pty(Session *s, const char *command)
                 * Do common processing for the child, such as execing
                 * the command.
                 */
-               do_child(s, command);
-               /* NOTREACHED */
+               do_child(s, command);
+               /* NOTREACHED */
        default:
                break;
        }
@@ -785,17 +786,19 @@ do_exec(Session *s, const char *command)
        if (options.adm_forced_command) {
                original_command = command;
                command = options.adm_forced_command;
-               if (IS_INTERNAL_SFTP(command))
-                       s->is_subsystem = SUBSYSTEM_INT_SFTP;
-               else if (s->is_subsystem)
+               if (IS_INTERNAL_SFTP(command)) {
+                       s->is_subsystem = s->is_subsystem ?
+                           SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR;
+               } else if (s->is_subsystem)
                        s->is_subsystem = SUBSYSTEM_EXT;
                debug("Forced command (config) '%.900s'", command);
        } else if (forced_command) {
                original_command = command;
                command = forced_command;
-               if (IS_INTERNAL_SFTP(command))
-                       s->is_subsystem = SUBSYSTEM_INT_SFTP;
-               else if (s->is_subsystem)
+               if (IS_INTERNAL_SFTP(command)) {
+                       s->is_subsystem = s->is_subsystem ?
+                           SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR;
+               } else if (s->is_subsystem)
                        s->is_subsystem = SUBSYSTEM_EXT;
                debug("Forced command (key option) '%.900s'", command);
        }
@@ -845,7 +848,7 @@ do_login(Session *s, const char *command)
        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);
                }
@@ -1374,26 +1377,32 @@ static void
 do_nologin(struct passwd *pw)
 {
        FILE *f = NULL;
-       char buf[1024];
+       char buf[1024], *nl, *def_nl = _PATH_NOLOGIN;
+       struct stat sb;
 
 #ifdef HAVE_LOGIN_CAP
-       if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
-               f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
-                   _PATH_NOLOGIN), "r");
+       if (login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
+               return;
+       nl = login_getcapstr(lc, "nologin", def_nl, def_nl);
 #else
-       if (pw->pw_uid)
-               f = fopen(_PATH_NOLOGIN, "r");
+       if (pw->pw_uid == 0)
+               return;
+       nl = def_nl;
 #endif
-       if (f) {
-               /* /etc/nologin exists.  Print its contents and exit. */
-               logit("User %.100s not allowed because %s exists",
-                   pw->pw_name, _PATH_NOLOGIN);
-               while (fgets(buf, sizeof(buf), f))
-                       fputs(buf, stderr);
-               fclose(f);
-               fflush(NULL);
-               exit(254);
+       if (stat(nl, &sb) == -1) {
+               if (nl != def_nl)
+                       xfree(nl);
+               return;
        }
+
+       /* /etc/nologin exists.  Print its contents if we can and exit. */
+       logit("User %.100s not allowed because %s exists", pw->pw_name, nl);
+       if ((f = fopen(nl, "r")) != NULL) {
+               while (fgets(buf, sizeof(buf), f))
+                       fputs(buf, stderr);
+               fclose(f);
+       }
+       exit(254);
 }
 
 /*
@@ -1466,11 +1475,6 @@ do_setusercontext(struct passwd *pw)
        if (getuid() == 0 || geteuid() == 0)
 #endif /* HAVE_CYGWIN */
        {
-
-#ifdef HAVE_SETPCRED
-               if (setpcred(pw->pw_name, (char **)NULL) == -1)
-                       fatal("Failed to set process credentials");
-#endif /* HAVE_SETPCRED */
 #ifdef HAVE_LOGIN_CAP
 # ifdef __bsdi__
                setpgid(0, 0);
@@ -1538,6 +1542,10 @@ do_setusercontext(struct passwd *pw)
                        free(chroot_path);
                }
 
+#ifdef HAVE_SETPCRED
+               if (setpcred(pw->pw_name, (char **)NULL) == -1)
+                       fatal("Failed to set process credentials");
+#endif /* HAVE_SETPCRED */
 #ifdef HAVE_LOGIN_CAP
                if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
                        perror("unable to set user context (setuser)");
@@ -1784,7 +1792,11 @@ do_child(Session *s, const char *command)
        /* restore SIGPIPE for child */
        signal(SIGPIPE, SIG_DFL);
 
-       if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
+       if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) {
+               printf("This service allows sftp connections only.\n");
+               fflush(NULL);
+               exit(1);
+       } else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
                extern int optind, optreset;
                int i;
                char *p, *args;
@@ -1797,9 +1809,14 @@ do_child(Session *s, const char *command)
                argv[i] = NULL;
                optind = optreset = 1;
                __progname = argv[0];
+#ifdef WITH_SELINUX
+               ssh_selinux_change_context("sftpd_t");
+#endif
                exit(sftp_server_main(i, argv, s->pw));
        }
 
+       fflush(NULL);
+
        if (options.use_login) {
                launch_login(pw, hostname);
                /* NEVERREACHED */
@@ -2110,16 +2127,16 @@ session_subsystem_req(Session *s)
                if (strcmp(subsys, options.subsystem_name[i]) == 0) {
                        prog = options.subsystem_command[i];
                        cmd = options.subsystem_args[i];
-                       if (!strcmp(INTERNAL_SFTP_NAME, prog)) {
+                       if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) {
                                s->is_subsystem = SUBSYSTEM_INT_SFTP;
-                       } else if (stat(prog, &st) < 0) {
-                               error("subsystem: cannot stat %s: %s", prog,
-                                   strerror(errno));
-                               break;
+                               debug("subsystem: %s", prog);
                        } else {
+                               if (stat(prog, &st) < 0)
+                                       debug("subsystem: cannot stat %s: %s",
+                                           prog, strerror(errno));
                                s->is_subsystem = SUBSYSTEM_EXT;
+                               debug("subsystem: exec() %s", cmd);
                        }
-                       debug("subsystem: exec() %s", cmd);
                        success = do_exec(s, cmd) == 0;
                        break;
                }