[PATCH] dbus: clear guid_from_server if send_negotiate_unix_fd failed

[rongqing.li at windriver.com]

From: Roy Li <rongqing.li at windriver.com>

Upstream-Status: Pending

bus-test dispatch test failed with below information:
    ./bus/bus-test: Running message dispatch test
    Activating service name='org.freedesktop.DBus.TestSuiteEchoService'
    Successfully activated service 'org.freedesktop.DBus.TestSuiteEchoService'
    6363: assertion failed "_dbus_string_get_length (& DBUS_AUTH_CLIENT (auth)->guid_from_server) == 0" file "dbus-auth.c" line 1545 function process_ok
      ./bus/bus-test(_dbus_print_backtrace+0x29) [0x80cb969]
      ./bus/bus-test(_dbus_abort+0x14) [0x80cfb44]
      ./bus/bus-test(_dbus_real_assert+0x53) [0x80b52c3]
      ./bus/bus-test() [0x80e24da]
      ./bus/bus-test(_dbus_auth_do_work+0x388) [0x80e3848]
      ./bus/bus-test() [0x80aea49]
      ./bus/bus-test() [0x80affde]
      ./bus/bus-test(_dbus_transport_handle_watch+0xb1) [0x80ad841]
      ./bus/bus-test(_dbus_connection_handle_watch+0x104) [0x8089174]
      ./bus/bus-test(dbus_watch_handle+0xd8) [0x80b15e8]
      ./bus/bus-test(_dbus_loop_iterate+0x4a9) [0x80d1509]
      ./bus/bus-test(bus_test_run_clients_loop+0x5d) [0x808129d]
      ./bus/bus-test() [0x806cab0]
      ./bus/bus-test() [0x806e0ca]
      ./bus/bus-test() [0x806da6f]
      ./bus/bus-test(_dbus_test_oom_handling+0x18c) [0x80b5c8c]
      ./bus/bus-test() [0x806f723]
      ./bus/bus-test(bus_dispatch_test+0x3c) [0x8071aac]
      ./bus/bus-test(main+0x1b7) [0x805acc7]
      /lib/libc.so.6(__libc_start_main+0xf3) [0x45f919b3]
      ./bus/bus-test() [0x805ae39]

The stack is below:
    #0  0xffffe425 in __kernel_vsyscall ()
    #1  0x45fa62d6 in raise () from /lib/libc.so.6
    #2  0x45fa9653 in abort () from /lib/libc.so.6
    #3  0x080cfb65 in _dbus_abort () at dbus-sysdeps.c:94
    #4  0x080b52c3 in _dbus_real_assert (condition=0,
        condition_text=condition_text at entry=0x8117a38 "_dbus_string_get_length (& DBUS_AUTH_CLIENT (auth)->guid_from_server) == 0",
        file=file at entry=0x8117273 "dbus-auth.c", line=line at entry=1545,
        func=func at entry=0x8117f8e <__FUNCTION__.3492> "process_ok")
        data=0x8157290) at dbus-connection.c:1515
    #0  0x00000033fee353e9 in raise () from /lib64/libc.so.6
    #1  0x00000033fee38508 in abort () from /lib64/libc.so.6
    #2  0x000000000047d585 in _dbus_abort () at dbus-sysdeps.c:94
    #3  0x0000000000466486 in _dbus_real_assert (condition=<optimized out>,
        condition_text=condition_text at entry=0x4c2988 "_dbus_string_get_length (& DBUS_AUTH_CLIENT (auth)->guid_from_server) == 0",
        file=file at entry=0x4c21a5 "dbus-auth.c", line=line at entry=1546,
        func=func at entry=0x4c2fce <__FUNCTION__.3845> "process_ok")
        at dbus-internals.c:931
    #4  0x000000000048d424 in process_ok (args_from_ok=0x7fffffffe480,
        auth=0x6ff340) at dbus-auth.c:1546
    #5  handle_client_state_waiting_for_data (auth=0x6ff340,
        command=<optimized out>, args=0x7fffffffe480) at dbus-auth.c:1996
    #6  0x000000000048e789 in process_command (auth=0x6ff340) at dbus-auth.c:2208
    #7  _dbus_auth_do_work (auth=0x6ff340) at dbus-auth.c:2458
    #8  0x000000000046091d in do_authentication (
        transport=transport at entry=0x6ffaa0, do_reading=do_reading at entry=1,
        do_writing=do_writing at entry=0,
        auth_completed=auth_completed at entry=0x7fffffffe55c)
        at dbus-transport-socket.c:442
    #9  0x0000000000461d08 in socket_handle_watch (transport=0x6ffaa0,
        watch=0x6f4190, flags=1) at dbus-transport-socket.c:921
    #10 0x000000000045fa3a in _dbus_transport_handle_watch (transport=0x6ffaa0,

Once send_negotiate_unix_fd failed, this failure will happen, since
auth->guid_from_server has been set to some value before
send_negotiate_unix_fd. send_negotiate_unix_fd failure will lead to
this auth be handled by process_ok again, but this auth->guid_from_server
is not zero.

So we should clear auth->guid_from_server if send_negotiate_unix_fd failed

Signed-off-by: Roy Li <rongqing.li at windriver.com>
---
 dbus/dbus-auth.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/dbus/dbus-auth.c b/dbus/dbus-auth.c
index d2c37a7..37b45c6 100644
--- a/dbus/dbus-auth.c
+++ b/dbus/dbus-auth.c
@@ -1571,8 +1571,13 @@ process_ok(DBusAuth *auth,
   _dbus_verbose ("Got GUID '%s' from the server\n",
                  _dbus_string_get_const_data (& DBUS_AUTH_CLIENT (auth)->guid_from_server));
 
-  if (auth->unix_fd_possible)
-    return send_negotiate_unix_fd(auth);
+  if (auth->unix_fd_possible) {
+     if (!send_negotiate_unix_fd(auth)) {
+         _dbus_string_set_length (& DBUS_AUTH_CLIENT (auth)->guid_from_server, 0);
+         return FALSE;
+     }
+     return TRUE;
+  }
 
   _dbus_verbose("Not negotiating unix fd passing, since not possible\n");
   return send_begin (auth);
-- 
1.7.10.4