Description of problem:
Not sure where the real problem is, so filing this against tigervnc for now. Some recent update appears to have broken the combination of Xvnc and KDM (via XDMCP).
When I connect, the vncviewer window briefly appears showing the KDM background. Then it closes and the client says "End of stream".
On the server, syslog contains:
kdm: localhost:10: Abnormal termination of greeter for display localhost:10, code 1, signal 0
X Error of failed request: BadAccess (attempt to access private resource denied)
Major opcode of failed request: 130 (MIT-SHM)
Minor opcode of failed request: 1 (X_ShmAttach)
Serial number of failed request: 348
Current serial number in output stream: 349
I am using a systemd socket to start Xvnc on demand. xvnc.socket contains:
Description=Socket for Xvnc display :10
And xvnc@.service contains:
Description=VNC remote display :10
ExecStart=-/usr/bin/Xvnc -SecurityTypes None -query 127.0.0.1 -inetd -once :10
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Configure KDM to accept XDMCP requests from localhost.
2. Configure Xvnc as above.
Turns out it works if I run Xvnc as root (by removing the "User=nobody" line from xvnc@.service). Disabling the MIT-SHM extension (by adding "-extension MIT-SHM" to the ExecStart line also works).
I'm going to close this, but it would be interesting to know if this is the expected behavior. After all, it was working with configuration previously.