netlink: request all matches when requesting interface and address lists

[awhitcroft]

Avahi uses netlink to determine the list of interfaces and the list of addresses in the system. When doing so we perform a NLM_F_ROOT search. Previously this would (incorrectly) return all matches due to a bug in the kernel decoding of the NLM_F_* flags. Following the commit below this is now corrected leading the avahi daemon to hang on start:

commit 0ab03c2b1478f2438d2c80204f7fef65b1bca9cf Author: Jan Engelhardt <jengelh@…> Date: Fri Jan 7 03:15:05 2011 +0000

netlink: test for all flags of the NLM_F_DUMP composite

See attached patch which fixed up our netlink request to also request NLM_F_MATCH to formally request all matches.

[lennart]

A similar patch has already been merged now.