Unable to start session using XDMCP

Unable to start session using XDMCP

[Alexander Pokluda]

I have run into a problem again where I am unable to start a session
using XDMCP. I am trying to connect to multiple remote machines
running CentOS 5.5 using XWin 1.10.2.

When I run the command

xwin -nodecoration +xinerama -screen 0 @1 -screen 1 @2 -from
10.3.12.47 -query 10.3.147.22

I get two black windows (with no titlebars) that do nothing for a
while and then eventually close and reopen. If I watch what's
happening using Wireshark, I see

Local Machine		Remote Machine
---------------		---------------
Query
			Willing
Request
			Accept
Manage
Manage
Manage
(many more times)

If I look in the XWin log, I see

[...]
[719987.046] XDM: too many retransmissions, declaring session dead
[...]

(the full log is pasted below). Oddly, for some remote machines, I
occasionally see this behaviour while most of the time it works but
for others, I seem to get this behaviour all the time and it never
seems to work.

Any help would be greatly appreciated.

------

Welcome to the XWin X Server
Vendor: The Cygwin/X Project
Release: 1.10.2.0
OS: Windows 7 Service Pack 1 [Windows NT 6.1 build 7601] (WoW64)
Package: version 1.10.2-2 built 2011-07-07

XWin was started with the following command line:

xwin -nodecoration +xinerama -screen 0 @1 -screen 1 @2 -from
 10.3.12.47 -query 10.3.147.22

ddxProcessArgument - Initializing default screens
winInitializeScreenDefaults - primary monitor w 1680 h 1050
winInitializeDefaultScreens - native DPI x 96 y 96
winInitializeScreens - 1
winInitializeScreen - 0
ddxProcessArgument - screen - Found Valid ``@Monitor'' = 1 arg
winInitializeScreens - 2
winInitializeScreen - 1
ddxProcessArgument - screen - Found Valid ``@Monitor'' = 2 arg
[719859.484] (II) xorg.conf is not supported
[719859.484] (II) See http://x.cygwin.com/docs/faq/cygwin-x-faq.html
for more information
[719859.484] LoadPreferences: /cygdrive/c/Users/alpokluda/.XWinrc not found
[719859.484] LoadPreferences: Loading /etc/X11/system.XWinrc
[719859.484] LoadPreferences: Done parsing the configuration file...
[719859.515] winDetectSupportedEngines - DirectDraw installed, allowing ShadowDD
[719859.515] winDetectSupportedEngines - Windows NT, allowing PrimaryDD
[719859.515] winDetectSupportedEngines - DirectDraw4 installed,
allowing ShadowDDNL
[719859.562] winDetectSupportedEngines - Returning, supported engines 0000001f
[719859.562] winSetEngine - Using Shadow DirectDraw NonLocking
[719859.562] winScreenInit - Using Windows display depth of 32 bits per pixel
[719859.749] winFinishScreenInitFB - Masks: 00ff0000 0000ff00 000000ff
[719859.749] Screen 0 added at virtual desktop coordinate (1680,0).
[719859.749] winSetEngine - Using Shadow DirectDraw NonLocking
[719859.749] winScreenInit - Using Windows display depth of 32 bits per pixel
[719859.905] winFinishScreenInitFB - Masks: 00ff0000 0000ff00 000000ff
[719859.905] Screen 1 added at virtual desktop coordinate (0,0).
[719859.905] MIT-SHM extension disabled due to lack of kernel support
[719859.921] XFree86-Bigfont extension local-client optimization
disabled due to lack of shared memory support in the kernel
[719859.952] (II) AIGLX: Loaded and initialized /usr/lib/dri/swrast_dri.so
[719859.952] (II) GLX: Initialized DRISWRAST GL provider for screen 0
[719859.952] (II) AIGLX: Loaded and initialized /usr/lib/dri/swrast_dri.so
[719859.952] (II) GLX: Initialized DRISWRAST GL provider for screen 1
[719859.967] [dix] Could not init font path element
/usr/share/fonts/TTF/, removing from list!
[719859.967] [dix] Could not init font path element
/usr/share/fonts/OTF/, removing from list!
[719859.967] [dix] Could not init font path element
/usr/share/fonts/Type1/, removing from list!
[719860.342] winPointerWarpCursor - Discarding first warp: 754 525
[719860.342] (--) 3 mouse buttons found
[719860.342] (--) Setting autorepeat to delay=500, rate=31
[719860.342] (--) Windows keyboard layout: "00010409" (00010409)
"United States-Dvorak", type 4
[719860.342] (--) Found matching XKB configuration "English (USA,Dvorak)"
[719860.342] (--) Model = "pc105" Layout = "dvorak" Variant = "none"
Options = "none"
[719860.342] Rules = "base" Model = "pc105" Layout = "dvorak" Variant
= "none" Options = "none"
[719860.654] winBlockHandler - pthread_mutex_unlock()
[719860.654] winBlockHandler - pthread_mutex_unlock()
[719987.046] XDM: too many retransmissions, declaring session dead
[719987.202] 6 XSELINUXs still allocated at reset
[719987.217] SCREEN: 0 objects of 92 bytes = 0 total bytes 0 private allocs
[719987.217] DEVICE: 4 objects of 28 bytes = 112 total bytes 0 private allocs
[719987.217] CLIENT: 0 objects of 148 bytes = 0 total bytes 0 private allocs
[719987.217] WINDOW: 0 objects of 60 bytes = 0 total bytes 0 private allocs
[719987.217] PIXMAP: 2 objects of 28 bytes = 56 total bytes 0 private allocs
[719987.217] GC: 0 objects of 64 bytes = 0 total bytes 0 private allocs
[719987.217] CURSOR: 0 objects of 8 bytes = 0 total bytes 0 private allocs
[719987.217] CURSOR_BITS: 0 objects of 8 bytes = 0 total bytes 0 private allocs
[719987.217] TOTAL: 6 objects, 168 bytes, 0 allocs
[719987.217] 4 DEVICEs still allocated at reset
[719987.217] DEVICE: 4 objects of 28 bytes = 112 total bytes 0 private allocs
[719987.217] CLIENT: 0 objects of 148 bytes = 0 total bytes 0 private allocs
[719987.217] WINDOW: 0 objects of 60 bytes = 0 total bytes 0 private allocs
[719987.217] PIXMAP: 2 objects of 28 bytes = 56 total bytes 0 private allocs
[719987.217] GC: 0 objects of 64 bytes = 0 total bytes 0 private allocs
[719987.217] CURSOR: 0 objects of 8 bytes = 0 total bytes 0 private allocs
[719987.217] CURSOR_BITS: 0 objects of 8 bytes = 0 total bytes 0 private allocs
[719987.217] TOTAL: 6 objects, 168 bytes, 0 allocs
[719987.217] 2 PIXMAPs still allocated at reset
[719987.217] PIXMAP: 2 objects of 28 bytes = 56 total bytes 0 private allocs
[719987.217] GC: 0 objects of 64 bytes = 0 total bytes 0 private allocs
[719987.217] CURSOR: 0 objects of 8 bytes = 0 total bytes 0 private allocs
[719987.217] CURSOR_BITS: 0 objects of 8 bytes = 0 total bytes 0 private allocs
[719987.217] TOTAL: 2 objects, 56 bytes, 0 allocs
[719987.217] (II) xorg.conf is not supported
[719987.217] (II) See http://x.cygwin.com/docs/faq/cygwin-x-faq.html
for more information
[719987.217] LoadPreferences: /cygdrive/c/Users/alpokluda/.XWinrc not found
[719987.217] LoadPreferences: Loading /etc/X11/system.XWinrc
[719987.217] LoadPreferences: Done parsing the configuration file...
[719987.249] winDetectSupportedEngines - DirectDraw installed, allowing ShadowDD
[719987.249] winDetectSupportedEngines - Windows NT, allowing PrimaryDD
[719987.249] winDetectSupportedEngines - DirectDraw4 installed,
allowing ShadowDDNL
[719987.280] winDetectSupportedEngines - Returning, supported engines 0000001f
[719987.280] winSetEngine - Using Shadow DirectDraw NonLocking
[719987.280] winScreenInit - Using command line depth of 32 bpp
[719987.483] winFinishScreenInitFB - Masks: 00ff0000 0000ff00 000000ff
[719987.483] Screen 0 added at virtual desktop coordinate (1680,0).
[719987.483] winSetEngine - Using Shadow DirectDraw NonLocking
[719987.483] winScreenInit - Using command line depth of 32 bpp
[719987.529] winFinishScreenInitFB - Masks: 00ff0000 0000ff00 000000ff
[719987.529] Screen 1 added at virtual desktop coordinate (0,0).
[719987.529] MIT-SHM extension disabled due to lack of kernel support
[719987.529] XFree86-Bigfont extension local-client optimization
disabled due to lack of shared memory support in the kernel
[719987.576] (II) AIGLX: Loaded and initialized /usr/lib/dri/swrast_dri.so
[719987.576] (II) GLX: Initialized DRISWRAST GL provider for screen 0
[719987.576] (II) AIGLX: Loaded and initialized /usr/lib/dri/swrast_dri.so
[719987.576] (II) GLX: Initialized DRISWRAST GL provider for screen 1
[719987.576] [dix] Could not init font path element
/usr/share/fonts/TTF/, removing from list!
[719987.576] [dix] Could not init font path element
/usr/share/fonts/OTF/, removing from list!
[719987.576] [dix] Could not init font path element
/usr/share/fonts/Type1/, removing from list!
[719987.919] (--) 3 mouse buttons found
[719987.919] (--) Setting autorepeat to delay=500, rate=31
[719987.919] (--) Windows keyboard layout: "00010409" (00010409)
"United States-Dvorak", type 4
[719987.919] (--) Found matching XKB configuration "English (USA,Dvorak)"
[719987.919] (--) Model = "pc105" Layout = "dvorak" Variant = "none"
Options = "none"
[719987.919] Rules = "base" Model = "pc105" Layout = "dvorak" Variant
= "none" Options = "none"
[719988.247] winBlockHandler - pthread_mutex_unlock()
[719988.247] winBlockHandler - pthread_mutex_unlock()
[719991.804] winDeinitMultiWindowWM - Noting shutdown in progress

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Re: Unable to start session using XDMCP

[Jon TURNEY]

On 12/07/2011 22:15, Alexander Pokluda wrote:
> I have run into a problem again where I am unable to start a session
> using XDMCP. I am trying to connect to multiple remote machines
> running CentOS 5.5 using XWin 1.10.2.
> 
> When I run the command
> 
> xwin -nodecoration +xinerama -screen 0 @1 -screen 1 @2 -from
> 10.3.12.47 -query 10.3.147.22
> 
> I get two black windows (with no titlebars) that do nothing for a
> while and then eventually close and reopen. If I watch what's
> happening using Wireshark, I see
> 
> Local Machine		Remote Machine
> ---------------		---------------
> Query
> 			Willing
> Request
> 			Accept
> Manage
> Manage
> Manage
> (many more times)

This seems slightly different to that failures you were seeing before, where
the Request packet did not arrive at the destination (although the reason for
that was never clear)

Can you send me the corresponding .pcap file, please.

> If I look in the XWin log, I see
> 
> [...]
> [719987.046] XDM: too many retransmissions, declaring session dead
> [...]
> 
> (the full log is pasted below). Oddly, for some remote machines, I
> occasionally see this behaviour while most of the time it works but
> for others, I seem to get this behaviour all the time and it never
> seems to work.
> 
> Any help would be greatly appreciated.

This seemed to be working for you back in March (see [1]), so I guess the
important question is "what has changed?"

[1] http://cygwin.com/ml/cygwin-xfree/2011-03/msg00011.html

-- 
Jon TURNEY
Volunteer Cygwin/X X Server maintainer

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Re: Unable to start session using XDMCP

[Jon TURNEY]

On 13/07/2011 15:04, Alexander Pokluda wrote:
> I have attached two packet captures. In the first file, it appears
> that the remote GDM stops responding after sending the accept packet
> but the capture in the second file was taken immediately after the
> first capture and restarting XWin.

Looking at those packet captures, I can't see anything that XWin is doing
wrong.  So I can only offer generic advice: Are the Manage requests arriving
at and being accepted by the remote host?

> On Wed, Jul 13, 2011 at 8:29 AM, Jon TURNEY <jon.turney@dronecode.org.uk> wrote:
>> On 12/07/2011 22:15, Alexander Pokluda wrote:
>>> I have run into a problem again where I am unable to start a session
>>> using XDMCP. I am trying to connect to multiple remote machines
>>> running CentOS 5.5 using XWin 1.10.2.
[snip]
>>
>> This seemed to be working for you back in March (see [1]), so I guess the
>> important question is "what has changed?"
>>
>> [1] http://cygwin.com/ml/cygwin-xfree/2011-03/msg00011.html

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