I believe I got a vague feeling about what is going wrong. So the isc library which now is shared for bind9 and dhcp is compiled (because bind9 is rather wanted that way) with threads enabled. Before that the export version of the library was not. So an isc_app which dhclient creates and runs was more or less a loop handling events. Now this creates a series of threads.
The problem looks to be that dhclient (and probably dhcpd, too) set up the isc_app context and then do a fork() (in daemon mode). The man page of fork() clearly states that the child will be single threaded. So when dhclient calls dispatch() to run the isc_app this probably only runs a single control loop more or less waiting for the threads (which do not run, maybe not even exist anymore) to do the work. The signal handling might be related to that as well. With threads only one of them should handle signals and somehow synchronize with the rest. Maybe the new library is not handling that correctly. Since this does not work regardless of running as daemon or not. But I have not understood all the details there. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to isc-dhcp in Ubuntu. https://bugs.launchpad.net/bugs/1551351 Title: dhclient does not renew leases Status in bind9 package in Ubuntu: Confirmed Status in isc-dhcp package in Ubuntu: Confirmed Status in bind9 source package in Xenial: Confirmed Status in isc-dhcp source package in Xenial: Confirmed Bug description: Release: Xenial I think this only recently started after some bind9 updates triggered a rebuild. When booting dhclient gets started and acquires an IP address, but it does seem to lock up somewhere as it does not renew the lease. In my environment I set the lease time to 5 minutes, so I notice such things rather soon. I looked on the dhcp server side but saw any further dhcp messages come in from the client side. Related bugs: * bug 1551415: systemctl stop networking hang / timeout ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: isc-dhcp-client 4.3.3-5ubuntu8 ProcVersionSignature: Ubuntu 4.4.0-9.24-generic 4.4.3 Uname: Linux 4.4.0-9-generic x86_64 ApportVersion: 2.20-0ubuntu3 Architecture: amd64 Date: Mon Feb 29 12:32:52 2016 DhclientLeases: SourcePackage: isc-dhcp UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/bind9/+bug/1551351/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
