Use fine grained locks while sending NDP packets

Previously when sending NDP DAD or RS messages, we would hold a shared
lock which lead to deadlocks (due to synchronous packet loooping
(e.g. pipe and loopback link endpoints)) and lock contention.

Writing packets may be an expensive operation which could prevent other
goroutines from doing meaningful work if a shared lock is held while
writing packets.

This change upates the NDP DAD/RS timers to not hold shared locks while
sending packets.

PiperOrigin-RevId: 356053146

0 files changed, 0 insertions, 0 deletions