- djm@cvs.openbsd.org 2008/06/13 00:16:49

     [mux.c]
     fall back to creating a new TCP connection on most multiplexing errors
     (socket connect fail, invalid version, refused permittion, corrupted
     messages, etc.); bz #1329 ok dtucker@

diff --git a/ChangeLog b/ChangeLog
index 5bcd79c8e2af1813b28a81659efd5ea0f6981a2a..a229b0ca7195398e2a3b35ffe07e8c80b59939e9 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -143,6 +143,11 @@
      [sftp.h log.h]
      replace __dead with __attribute__((noreturn)), makes things
      a little easier to port.  Also, add it to sigdie().  ok djm@
+   - djm@cvs.openbsd.org 2008/06/13 00:16:49
+     [mux.c]
+     fall back to creating a new TCP connection on most multiplexing errors
+     (socket connect fail, invalid version, refused permittion, corrupted
+     messages, etc.); bz #1329 ok dtucker@
   - (dtucker) [clientloop.c serverloop.c]  channel_register_filter now
     takes 2 more args.  with djm@
 

diff --git a/mux.c b/mux.c
index 8f7bfb79320363aee9682e3532893d789e38833c..aaa3a4ee29a1519b86c1b2ac24667be24657273a 100644 (file)
--- a/mux.c
+++ b/mux.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: mux.c,v 1.4 2008/06/12 15:19:17 djm Exp $ */
+/* $OpenBSD: mux.c,v 1.5 2008/06/13 00:16:49 djm Exp $ */
 /*
  * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
  *
@@ -144,10 +144,16 @@ muxserver_listen(void)
        old_umask = umask(0177);
        if (bind(muxserver_sock, (struct sockaddr *)&addr, addr_len) == -1) {
                muxserver_sock = -1;
-               if (errno == EINVAL || errno == EADDRINUSE)
-                       fatal("ControlSocket %s already exists",
-                           options.control_path);
-               else
+               if (errno == EINVAL || errno == EADDRINUSE) {
+                       error("ControlSocket %s already exists, "
+                           "disabling multiplexing", options.control_path);
+                       close(muxserver_sock);
+                       muxserver_sock = -1;
+                       xfree(options.control_path);
+                       options.control_path = NULL;
+                       options.control_master = SSHCTL_MASTER_NO;
+                       return;
+               } else
                        fatal("%s bind(): %s", __func__, strerror(errno));
        }
        umask(old_umask);
@@ -500,7 +506,7 @@ muxclient(const char *path)
        Buffer m;
        char *term;
        extern char **environ;
-       u_int  flags;
+       u_int allowed, flags;
 
        if (muxclient_command == 0)
                muxclient_command = SSHMUX_COMMAND_OPEN;
@@ -571,17 +577,38 @@ muxclient(const char *path)
        /* Send our command to server */
        buffer_put_int(&m, muxclient_command);
        buffer_put_int(&m, flags);
-       if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
-               fatal("%s: msg_send", __func__);
+       if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) {
+               error("%s: msg_send", __func__);
+ muxerr:
+               close(sock);
+               buffer_free(&m);
+               if (muxclient_command != SSHMUX_COMMAND_OPEN)
+                       cleanup_exit(255);
+               logit("Falling back to non-multiplexed connection");
+               xfree(options.control_path);
+               options.control_path = NULL;
+               options.control_master = SSHCTL_MASTER_NO;
+               return;
+       }
        buffer_clear(&m);
 
        /* Get authorisation status and PID of controlee */
-       if (ssh_msg_recv(sock, &m) == -1)
-               fatal("%s: msg_recv", __func__);
-       if (buffer_get_char(&m) != SSHMUX_VER)
-               fatal("%s: wrong version", __func__);
-       if (buffer_get_int(&m) != 1)
-               fatal("Connection to master denied");
+       if (ssh_msg_recv(sock, &m) == -1) {
+               error("%s: msg_recv", __func__);
+               goto muxerr;
+       }
+       if (buffer_get_char(&m) != SSHMUX_VER) {
+               error("%s: wrong version", __func__);
+               goto muxerr;
+       }
+       if (buffer_get_int_ret(&allowed, &m) != 0) {
+               error("%s: bad server reply", __func__);
+               goto muxerr;
+       }
+       if (allowed != 1) {
+               error("Connection to master denied");
+               goto muxerr;
+       }
        muxserver_pid = buffer_get_int(&m);
 
        buffer_clear(&m);
@@ -625,13 +652,22 @@ muxclient(const char *path)
                fatal("unrecognised muxclient_command %d", muxclient_command);
        }
 
-       if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
-               fatal("%s: msg_send", __func__);
+       if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) {
+               error("%s: msg_send", __func__);
+               goto muxerr;
+       }
 
        if (mm_send_fd(sock, STDIN_FILENO) == -1 ||
            mm_send_fd(sock, STDOUT_FILENO) == -1 ||
-           mm_send_fd(sock, STDERR_FILENO) == -1)
-               fatal("%s: send fds failed", __func__);
+           mm_send_fd(sock, STDERR_FILENO) == -1) {
+               error("%s: send fds failed", __func__);
+               goto muxerr;
+       }
+
+       /*
+        * Mux errors are non-recoverable from this point as the master
+        * has ownership of the session now.
+        */
 
        /* Wait for reply, so master has a chance to gather ttymodes */
        buffer_clear(&m);