- djm@cvs.openbsd.org 2009/11/19 23:39:50

     [session.c]
     bz#1606: error when an attempt is made to connect to a server
     with ForceCommand=internal-sftp with a shell session (i.e. not a
     subsystem session). Avoids stuck client when attempting to ssh to such a
     service. ok dtucker@

diff --git a/ChangeLog b/ChangeLog
index 72d5a21e1cc598ba583597dfb1aff5ba3c8c1038..0ece9c09d646e91eef99fb88690559afa5ddee05 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -61,6 +61,12 @@
      [clientloop.c]
      fix incorrect exit status when multiplexing and channel ID 0 is recycled
      bz#1570 reported by peter.oliver AT eon-is.co.uk; ok dtucker
+   - djm@cvs.openbsd.org 2009/11/19 23:39:50
+     [session.c]
+     bz#1606: error when an attempt is made to connect to a server
+     with ForceCommand=internal-sftp with a shell session (i.e. not a
+     subsystem session). Avoids stuck client when attempting to ssh to such a
+     service. ok dtucker@
 
 20091226
  - (tim) [contrib/cygwin/Makefile] Install ssh-copy-id and ssh-copy-id.1

diff --git a/session.c b/session.c
index 78192314aa21902b64ad81c977c59d867be74e1c..cc205386f3d1b597ac9630529caa0132f477cd02 100644 (file)
--- a/session.c
+++ b/session.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: session.c,v 1.247 2009/10/06 04:46:40 djm Exp $ */
+/* $OpenBSD: session.c,v 1.248 2009/11/19 23:39:50 djm 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;
@@ -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);
        }
@@ -1783,7 +1786,11 @@ 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;