From 56022a8fdd874c56bb61d8c82559e43044d1aa06 Mon Sep 17 00:00:00 2001 From: Salam Noureddine Date: Tue, 24 Dec 2013 14:17:02 -0800 Subject: [PATCH] ipv4: arp: update neighbour address when a gratuitous arp is received and arp_accept is set Gratuitous arp packets are useful in switchover scenarios to update client arp tables as quickly as possible. Currently, the mac address of a neighbour is only updated after a locktime period has elapsed since the last update. In most use cases such delays are unacceptable for network admins. Moreover, the "updated" field of the neighbour stucture doesn't record the last time the address of a neighbour changed but records any change that happens to the neighbour. This is clearly a bug since locktime uses that field as meaning "addr_updated". With this observation, I was able to perpetuate a stale address by sending a stream of gratuitous arp packets spaced less than locktime apart. With this change the address is updated when a gratuitous arp is received and the arp_accept sysctl is set. Signed-off-by: Salam Noureddine Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- Reading git-format-patch failed