New subject: [Bug 623254] Connecting To A System Via VNC Produces A Black Screen Only

18 Jul 2010

      http://bugzilla.novell.com/show_bug.cgi?id=623254

http://bugzilla.novell.com/show_bug.cgi?id=623254#c0

           Summary: Connecting To A System Via VNC Produces A Black Screen
                    Only
    Classification: openSUSE
           Product: openSUSE 11.3
           Version: Final
          Platform: PC
        OS/Version: openSUSE 11.3
            Status: NEW
          Severity: Major
          Priority: P5 - None
         Component: X.Org
        AssignedTo: bnc-team-xorg-bugs@forge.provo.novell.com
        ReportedBy: lnxgnome@gmail.com
         QAContact: xorg-maintainer-bugs@forge.provo.novell.com
                CC: max@novell.com, sndirsch@novell.com,
                    malv_star@hotmail.com, milan.zimmermann@sympatico.ca,
                    s2@forceway.com
          Found By: ---
           Blocker: ---

+++ This bug was initially created as a clone of Bug #591664 +++

When running GNOME as the default desktop environment, after enabling VNC
Remote Administration in YaST and telling the system to open the relevant ports
through the firewall on the target machine, a user attempts to start a remote
VNC session.  The connection is initiated and a response is received, but only
goes as far as producing a black screen with the standard X-server mouse icon
(a cross).  The mouse responds to input and moves around the screen area, but
no graphics are loaded and no login prompt is presented as it was in previous
versions of SuSE.

Reproducible: Always

Steps to Reproduce:
1. 32-bit system was upgraded from 11.2 to 11.3 after GA
2. GNOME is the default desktop environment.
3. Complete the installation and update the system
4. Start YaST
5. Enable Remote Administration, set it to start during boot, and open the
required firewall ports.
6. Choose a separate machine and start a VNC client (in my case, I tested with
vncviewer on openSuSE 11.2).
7. Attempt to connect to desktop 1 on the remote machine.
Actual Results:  
A black screen with an X mouse cursor appears.  The mouse responds to input,
but no graphics are loaded and no login prompt is produced.

(VNC Server machine specs w/IPv6 enabled)
xorg-x11-Xvnc-7.5_1.8.0-9.4.i586
LibVNCServer-0.9.7-5.1.i586
x11vnc-0.9.9-3.1.i586

eth0      Link encap:Ethernet  HWaddr 00:15:60:B7:2C:4F  
          inet addr:192.168.101.31  Bcast:192.168.101.255  Mask:255.255.255.0
          inet6 addr: fe80::215:60ff:feb7:2c4f/64 Scope:Link

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
(/specs)

Expected Results:  
The GDM login prompt should appear and allow the user to begin a remote desktop
session.

This seems to be an issue with GDM and IPv6.
I have tested with IPv6 enabled and disabled (via YaST), on both the client and
server.

xdmcp is enabled in /etc/gdm/custom.conf.

Firewall is disabled.

/etc/hosts contains:
127.0.0.1    localhost.localdomain    localhost
::1             localhost ipv6-localhost ipv6-loopback
fe00::0         ipv6-localnet
ff00::0         ipv6-mcastprefix
ff02::1         ipv6-allnodes
ff02::2         ipv6-allrouters
ff02::3         ipv6-allhosts
127.0.0.2    moya.hopnet.lan moya

Xvnc is stared through xinetd
    server          = /usr/bin/Xvnc
tested with both
 server_args     = -noreset -inetd -once -query localhost -geometry 1024x768
-depth 16
AND
 server_args     = -noreset -inetd -once -query moya.hopnet.lan -geometry
1024x768 -depth 16

GDM has debug enabled, and I can see the follow anomaly when the VNC client
connects:
gdm[5248]: DEBUG(+): GdmXdmcpDisplayFactory: decode_packet: GIOCondition 1
gdm[5248]: DEBUG(+): Address family:2 (inet) hostname:(null) host:(null)
port:(null) local:1 loopback:1
gdm[5248]: DEBUG(+): Address family:2 (inet) hostname:(null) host:(null)
port:(null) local:1 loopback:1
gdm[5248]: DEBUG(+): Address family:2 (inet) hostname:(null) host:(null)
port:(null) local:0 loopback:0
gdm[5248]: DEBUG(+): GdmAddress: looking up hostname: moya.hopnet.lan
gdm[5248]: DEBUG(+): family=2 sock_type=1 protocol=6 flags=0x2
canonname=moya.hopnet.lan

gdm[5248]: DEBUG(+): family=2 sock_type=2 protocol=17 flags=0x2
canonname=(null)

gdm[5248]: DEBUG(+): family=2 sock_type=3 protocol=0 flags=0x2 canonname=(null)

gdm[5248]: DEBUG(+): Address family:10 (inet6) hostname:(null) host:(null)
port:(null) local:0 loopback:0
gdm[5248]: DEBUG(+): GdmXdmcpDisplayFactory: Received opcode QUERY from client
::ec01:80b7:2faf:7cb7%3075497972 : 54781
gdm[5248]: DEBUG(+): GdmXdmcpDisplayFactory: Sending WILLING to
::ec01:80b7:2faf:7cb7%3075497972

GDM only reports to send the WILLING msg via inet6, and ::ec01:80b7:2faf:7cb7
is not reachable on my network.  ( I'm unsure where it is getting this address
from, especially when IPv6 is disabled. )  The results are the same, with IPv6
enabled or disables, although the inet6 address reported in the debug messages
will vary across reboots of the client.

# ping6 ::ec01:80b7:2faf:7cb7
connect: Network is unreachable

-- 
Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.

[Bug 623254] New: Connecting To A System Via VNC Produces A Black Screen Only

tags

participants (1)