Re: [libvirt] [PATCH - 2 alternatives] util: fix libvirtd startup failure due to netlink error

On 05/01/2012 01:05 PM, Laine Stump wrote: > The two following patches fix the same problem (described in > https://bugzilla.redhat.com/show_bug.cgi?id=816465) in two alternate > ways - one by retrying the failing operation after a delay, the other by > using knowledge of how libnl works internally to artificially "reserve" > a particular address so libnl doesn't attempt to bind to it. > > You might think that libnl is the right place to fix this bug. > Unfortunately, that isn't possible, because it would involve changing > libnl's API - currently libnl decides what address to use for future > binds of a netlink socket at the time nl_handle_alloc() is called, but > doesn't actually attempt to bind it. Later, during nl_connect(), it > calls bind() with the address it had earlier decided. It would be nice > if we could just retry the bind with a different address when the first > attempt failed, but libnl allows client applications to retrieve the > bind address *before nl_connect() is called*, so an application may have > already gotten the address prior to calling nl_connect(), and changing > it would render the applications information incorrect. Does libnl-3 have the same issue? It would be interesting if Serge Hallyn's patches to support libnl-3 ended up allowing us to move to a version of the library that doesn't have the same fundamental flaw. Have we complained about this flaw to the libnl upstream folks?