XDMCP non-functional in Xubuntu 24.04?

bullgod · 2025-01-08 13:42:39

Has anyone have XDMCP working in Xubuntu 24.04?

The login screen works fine and I get a desktop and panel. The panel responds to mouse hover events, but the menu and any launcher clicks cause the panel (and desktop to crash).

I've tried this on two different servers and tried a fresh reinstall.

Also, an interesting data point one used to be able to draw to remote XServer

Start XMing on 192.168.12 (windows) with XDMCPHost="192.168.1.11" Xubuntu 18.04

192.168.1.11> DISPLAY=192.168.1.12:0 xterm  # This works on old installations.

But when trying to do the same to a newer Xubunutu 24 host starting the xterm kills the Xserver.

192.168.1.13> DISPLAY=192.168.1.12:0 xterm
xterm: cannot load font "-misc-fixed-medium-r-semicondensed--13-120-75-75-c-60-iso10646-1"
xterm: fatal IO error 11 (Resource temporarily unavailable) or KillClient on X server "192.168.1.12:0"

Has the new installation lost the abililty to draw on displays other than :0?

ToZ · 2025-01-08 21:06:50

xterm: cannot load font "-misc-fixed-medium-r-semicondensed--13-120-75-75-c-60-iso10646-1"

Do you mkfontscale installed? It appears to be part of the xfonts-utils package.

The login screen works fine and I get a desktop and panel. The panel responds to mouse hover events, but the menu and any launcher clicks cause the panel (and desktop to crash).

Do you have any log entries to see why its crashing?

bullgod · 2025-01-09 01:27:11

The font issue is a red-herring as xterm should full back to fonts it can find. Even then it shouldn't take the whole server down.

Logs from what? Where does XFCE log the panel menu not working or failing to to start a terminal?

ToZ · 2025-01-09 02:09:38

Look at ~/.xsession-errors or ~/.xsession-errors.old. Or possibly in your journal:

sudo journalctl | grep -i xdmcp

You can also run xfce4-panel in debug mode to see if it logs anything:

xfce4-panel -q
PANEL_DEBUG=1 xfce4-panel

bullgod · 2025-01-09 11:57:19

Failing:

xfce4-panel(main): version 4.18.4 on gtk+ 3.24.41 (3.24.41), glib 2.80.0 (2.80.0)
xfce4-panel(module-factory): reading /usr/share/xfce4/panel/plugins
xfce4-panel(application): found window manager after 1 tries
xfce4-panel(base-window): 0x5c4f5c7228c0: rgba visual=0x5c4f5c6f3d50, compositing=true
xfce4-panel(base-window): 0x5c4f5c7228c0: rgba visual=0x5c4f5c6f3d50, compositing=true
xfce4-panel(display-layout): 0x5c4f5c7228c0: display=:0.0{comp=true}, screen-0[0x5c4f5c6e88a0]=[3440,1440] (HDMI-3=[0,0;3440,1440])
xfce4-panel(positioning): 0x5c4f5c7228c0: screen=0x5c4f5c6e88a0, monitors=1, output-name=(null), span-monitors=false, base=0,0
xfce4-panel(positioning): 0x5c4f5c7228c0: working-area: screen=0x5c4f5c6e88a0, x=0, y=0, w=3440, h=1440
xfce4-panel(struts): 0x5c4f5c7228c0: top=25, start_x=0, end_x=3439
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/1
xfce4-panel(module): new item (type=external-wrapper, name=whiskermenu, id=1)
xfce4-panel(external): whiskermenu-1: child spawned; pid=9921, argc=7
xfce4-panel(module): new item (type=object-type, name=pager, id=13)
xfce4-panel(module): new item (type=object-type, name=launcher, id=12)
xfce4-panel(module): new item (type=object-type, name=tasklist, id=2)
xfce4-panel(module): new item (type=object-type, name=separator, id=3)
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/4
xfce4-panel(module): new item (type=external-wrapper, name=systray, id=4)
xfce4-panel(external): systray-4: child spawned; pid=9925, argc=7
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/5
xfce4-panel(module): new item (type=external-wrapper, name=notification-plugin, id=5)
xfce4-panel(external): notification-plugin-5: child spawned; pid=9926, argc=7
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/6
xfce4-panel(module): new item (type=external-wrapper, name=indicator, id=6)
xfce4-panel(external): indicator-6: child spawned; pid=9927, argc=7
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/8
xfce4-panel(module): new item (type=external-wrapper, name=power-manager-plugin, id=8)
xfce4-panel(external): power-manager-plugin-8: child spawned; pid=9928, argc=7
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/9
xfce4-panel(module): new item (type=external-wrapper, name=pulseaudio, id=9)
xfce4-panel(external): pulseaudio-9: child spawned; pid=9929, argc=7
xfce4-panel(module): new item (type=object-type, name=separator, id=10)
xfce4-panel(clock): trying to instantiate logind sleep monitor
xfce4-panel(module): new item (type=object-type, name=clock, id=11)
xfce4-panel(external): whiskermenu-1: child is embedded; 8 properties in queue
xfce4-panel(external): notification-plugin-5: child is embedded; 8 properties in queue
xfce4-panel(external): power-manager-plugin-8: child is embedded; 8 properties in queue
xfce4-panel(external): indicator-6: child is embedded; 8 properties in queue
xfce4-panel(external): pulseaudio-9: child is embedded; 8 properties in queue
xfce4-panel(external): systray-4: child is embedded; 8 properties in queue
xfce4-panel(systray): rgba visual is 0x5671faee7620
xfce4-panel(systray): registered manager on screen

Working:

$ xfce4-panel -q && PANEL_DEBUG=1 xfce4-panel
xfce4-panel(main): version 4.14.3 on gtk+ 3.24.20 (3.24.13), glib 2.64.6 (2.63.3)
xfce4-panel(module-factory): reading /usr/share/xfce4/panel/plugins
xfce4-panel(module-factory): reading /usr/share/xfce4/panel-plugins
xfce4-panel(application): found window manager after 1 tries
xfce4-panel(base-window): 0x55c1efae8c50: rgba visual=(nil), compositing=false
xfce4-panel(base-window): 0x55c1efae8c50: rgba visual=(nil), compositing=false
xfce4-panel(display-layout): 0x55c1efae8c50: display=192.168.1.212:0.0{comp=false}, screen-0[0x55c1efa7a020]=[3440,1400] (monitor-0=[0,0;3440,1400])
xfce4-panel(positioning): 0x55c1efae8c50: screen=0x55c1efa7a020, monitors=1, output-name=(null), span-monitors=false, base=0,0
xfce4-panel(positioning): 0x55c1efae8c50: working-area: screen=0x55c1efa7a020, x=0, y=0, w=3440, h=1400
xfce4-panel(struts): 0x55c1efae8c50: top=25, start_x=0, end_x=3439
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/1
xfce4-panel(module): new item (type=external-wrapper, name=whiskermenu, id=1)
xfce4-panel(external): whiskermenu-1: child spawned; pid=7681, argc=8
xfce4-panel(module): new item (type=object-type, name=pager, id=13)
xfce4-panel(module): new item (type=object-type, name=launcher, id=12)
xfce4-panel(module): new item (type=object-type, name=tasklist, id=2)
xfce4-panel(module): new item (type=object-type, name=separator, id=3)
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/4
xfce4-panel(module): new item (type=external-wrapper, name=systray, id=4)
xfce4-panel(external): systray-4: child spawned; pid=7684, argc=8
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/5
xfce4-panel(module): new item (type=external-wrapper, name=notification-plugin, id=5)
xfce4-panel(external): notification-plugin-5: child spawned; pid=7685, argc=8
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/6
xfce4-panel(module): new item (type=external-wrapper, name=indicator, id=6)
xfce4-panel(external): indicator-6: child spawned; pid=7686, argc=8
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/8
xfce4-panel(module): new item (type=external-wrapper, name=power-manager-plugin, id=8)
xfce4-panel(external): power-manager-plugin-8: child spawned; pid=7687, argc=8
xfce4-panel(external): register dbus path /org/xfce/Panel/Wrapper/9
xfce4-panel(module): new item (type=external-wrapper, name=pulseaudio, id=9)
xfce4-panel(external): pulseaudio-9: child spawned; pid=7688, argc=8
xfce4-panel(module): new item (type=object-type, name=separator, id=10)
xfce4-panel(module): new item (type=object-type, name=clock, id=11)
xfce4-panel(external): whiskermenu-1: child is embedded; 6 properties in queue
xfce4-panel(external): systray-4: child is embedded; 6 properties in queue
xfce4-panel(systray): rgba visual is (nil)
xfce4-panel(systray): registered manager on screen 0
xfce4-panel(external): indicator-6: child is embedded; 6 properties in queue
xfce4-panel(external): notification-plugin-5: child is embedded; 6 properties in queue
xfce4-panel(external): power-manager-plugin-8: child is embedded; 6 properties in queue
...

Running:

192.168.1.11>  sudo apt install xfonts-utils
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
xfonts-utils is already the newest version (1:7.7+6build3).
0 to upgrade, 0 to newly install, 0 to remove and 6 not to upgrade.

192.168.1.11> DISPLAY=192.168.1.212:0 xterm
xterm: cannot load font "-misc-fixed-medium-r-semicondensed--13-120-75-75-c-60-iso10646-1"
xterm: fatal IO error 11 (Resource temporarily unavailable) or KillClient on X server "192.168.1.212:0"

From syslog:

Jan 09 11:39:46 neuromancer at-spi-bus-launcher[4827]: XIO:  fatal IO error 104 (Connection reset by peer) on X server "192.168.1.212:0"
Jan 09 11:39:46 neuromancer at-spi-bus-launcher[4827]:       after 20 requests (20 known processed) with 0 events remaining.
Jan 09 11:39:46 neuromancer systemd[2764]: xfce4-notifyd.service: Main process exited, code=exited, status=1/FAILURE
Jan 09 11:39:46 neuromancer systemd[2764]: xfce4-notifyd.service: Failed with result 'exit-code'.
Jan 09 11:39:46 neuromancer polkitd[911]: Unregistered Authentication Agent for unix-session:c14 (system bus name :1.165, object path /org/gnome/PolicyKit1/AuthenticationAgent, locale en_GB.UTF-8) (disconnected from bus)
Jan 09 11:39:46 neuromancer lightdm[4708]: pam_unix(lightdm:session): session closed for user andy
Jan 09 11:39:46 neuromancer systemd[1]: session-c14.scope: Deactivated successfully.
Jan 09 11:39:46 neuromancer systemd[1]: session-c14.scope: Consumed 21.355s CPU time.
Jan 09 11:39:46 neuromancer systemd-logind[920]: Session c14 logged out. Waiting for processes to exit.
Jan 09 11:39:46 neuromancer systemd-logind[920]: Removed session c14.

From .xsession-errors:

Xlib:  extension "DPMS" missing on display "192.168.1.212:0.0".

The same error in syslog when launching app from menu:

Jan 09 11:54:51 neuromancer at-spi-bus-launcher[5518]: XIO:  fatal IO error 104 (Connection reset by peer) on X server "192.168.1.212:0"
Jan 09 11:54:51 neuromancer at-spi-bus-launcher[5518]:       after 28 requests (28 known processed) with 0 events remaining.
Jan 09 11:54:51 neuromancer systemd[2764]: xfce4-notifyd.service: Main process exited, code=exited, status=1/FAILURE
Jan 09 11:54:51 neuromancer polkitd[911]: Unregistered Authentication Agent for unix-session:c16 (system bus name :1.187, object path /org/gnome/PolicyKit1/AuthenticationAgent, locale en_GB.UTF-8) (disconnected from bus)
Jan 09 11:54:51 neuromancer systemd[2764]: xfce4-notifyd.service: Failed with result 'exit-code'.
Jan 09 11:54:52 neuromancer lightdm[5393]: pam_unix(lightdm:session): session closed for user andy
Jan 09 11:54:52 neuromancer systemd-logind[920]: Session c16 logged out. Waiting for processes to exit.
Jan 09 11:54:52 neuromancer systemd[1]: session-c16.scope: Deactivated successfully.
Jan 09 11:54:52 neuromancer systemd[1]: session-c16.scope: Consumed 22.597s CPU time

ToZ · 2025-01-09 13:11:03

Unfortunately there is nothing in those log files that helps identify the issue. Do you have an ~/.xsession-errors or ~/.xsession-errors.old file from the account that you logged into when the issue happened? Or possibly some core/crash file dumps?

I tested XDMCP on an ubuntu 24.04 server install + Xfce 4.20 and it works fine - both the session and the xterm test (I also get the font message so it is a red herring). However, I did not use XMing - just a Xephyr connection to localhost.

Perhaps the issue is with XMing?

bullgod · 2025-01-09 15:05:53

There are no core dumps that I can see. There's nothing in .xsession-errors[old] other than

** (xiccd:5676): CRITICAL **: 11:53:00.196: RandR 1.2 found on display 192.168.1.212:0.0 but 1.3 is needed

to explain the xiccd not starting, and this is on startup not when the when starting an xterm or display crash happens.

Xming has worked since forever, and it really is the only Windows Xserver going.

Last edited by bullgod (2025-01-09 15:06:57)

ToZ · 2025-01-09 22:06:26

Sorry but I don't have any windows computers available to test this aspect of it.

Xming has worked since forever, and it really is the only Windows Xserver going.

There is also vcxsrv, would you be able to try with it to see if it works? As a test.

bullgod · 2025-01-10 21:42:17

You are correct there is also VcXsrv (but I don't use this as it doesn't support the -rootless option so is useless for proper integration).
Nonetheless, I've tried VcXsrv and if anything it's actually worse then Xming, and crashes before mouse-clicks on the panel and doesn't seem to respond to hover events.

Last edited by bullgod (2025-01-13 15:12:31)

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#1 2025-01-08 13:42:39

XDMCP non-functional in Xubuntu 24.04?

#2 2025-01-08 21:06:50

Re: XDMCP non-functional in Xubuntu 24.04?

#3 2025-01-09 01:27:11

Re: XDMCP non-functional in Xubuntu 24.04?

#4 2025-01-09 02:09:38

Re: XDMCP non-functional in Xubuntu 24.04?

#5 2025-01-09 11:57:19

Re: XDMCP non-functional in Xubuntu 24.04?

#6 2025-01-09 13:11:03

Re: XDMCP non-functional in Xubuntu 24.04?

#7 2025-01-09 15:05:53

Re: XDMCP non-functional in Xubuntu 24.04?

#8 2025-01-09 22:06:26

Re: XDMCP non-functional in Xubuntu 24.04?

#9 2025-01-10 21:42:17

Re: XDMCP non-functional in Xubuntu 24.04?

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