Add a global rwlock, at_ifaddr_rw, to protect the global netatalk

address lists, at_ifaddr_list.  Acquire the lock, and use ifaddr
refcounts where necessary, to close most known address-related
races in netatalk.

Annotate one potential race in at_control() where we acquire an
ifaddr reference, drop the global lock, and scrub the address from
the ifnet before re-acquiring the global lock, which could allow
for a writer-writer race.

MFC after:	3 weeks

0 files changed, 0 insertions, 0 deletions