Public bug reported: After upgrading to Ubuntu 23.04, my laptop failed to discover our print server. The problem seems to have been caused by a new change in cups-browsed that was added to Ubuntu 23.04. I looked into it and found a small fix that seems to solve my issue.
Using the debug configuration for cupsd and cups-browsed, I looked through the logs and noticed the following line: failed to bind CUPS Browsing socket: Permission denied After reading more about printer advertisement and cups-browsed, I concluded that the printer is shared to my Ubuntu 23.04 laptop via CUPS on port 631. When I connected an Ubuntu 22.04 laptop to the WIFI network, I saw the printer really was being shared with CUPS on port 631. Cups-browsed was running as root on 22.04 while on 23.04 it is running as a new user - cups-browsed, but this new user didn't seem to have the necessary permissions to open a listening socket on port 631. The solution I tried was granting the relevant binding permissions to the binary with this command (on the 23.04): setcap cap_net_bind_service+ep /usr/sbin/cups-browsed After giving the permissions, my computer successfully discovered the printer, just like it used to on 22.04! I think the command should be added to the post install script or maybe the capability should be granted to the new cups-browsed user. I posted it as an issue in the CUPS project on github. They told me to post it here because its an Ubuntu issue: https://github.com/OpenPrinting/cups-browsed/issues/17 ** Affects: cups-browsed (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to cups-browsed in Ubuntu. https://bugs.launchpad.net/bugs/2028172 Title: Cups-browsed cannot bind to port 631 as non-root user on Ubuntu 23.04 Status in cups-browsed package in Ubuntu: New Bug description: After upgrading to Ubuntu 23.04, my laptop failed to discover our print server. The problem seems to have been caused by a new change in cups-browsed that was added to Ubuntu 23.04. I looked into it and found a small fix that seems to solve my issue. Using the debug configuration for cupsd and cups-browsed, I looked through the logs and noticed the following line: failed to bind CUPS Browsing socket: Permission denied After reading more about printer advertisement and cups-browsed, I concluded that the printer is shared to my Ubuntu 23.04 laptop via CUPS on port 631. When I connected an Ubuntu 22.04 laptop to the WIFI network, I saw the printer really was being shared with CUPS on port 631. Cups-browsed was running as root on 22.04 while on 23.04 it is running as a new user - cups-browsed, but this new user didn't seem to have the necessary permissions to open a listening socket on port 631. The solution I tried was granting the relevant binding permissions to the binary with this command (on the 23.04): setcap cap_net_bind_service+ep /usr/sbin/cups-browsed After giving the permissions, my computer successfully discovered the printer, just like it used to on 22.04! I think the command should be added to the post install script or maybe the capability should be granted to the new cups-browsed user. I posted it as an issue in the CUPS project on github. They told me to post it here because its an Ubuntu issue: https://github.com/OpenPrinting/cups-browsed/issues/17 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cups-browsed/+bug/2028172/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
