Validate DAD configs when initializing DAD state

Make sure that the initial configurations used by the DAD state is
valid.

Before this change, an invalid DAD configuration (with a zero-valued
retransmit timer) was used so the DAD state would attempt to resolve
DAD immediately.

This lead to a deadlock in TestDADResolve as when DAD resolves, the
stack notifies the NDP dispatcher which would attempt to write to an
unbuffered channel while holding a lock. The test goroutine also
attempts to obtain a stack.Route (before receiving from the channel)
which ends up attempting to take the same lock.

Test: stack_test.TestDADResolve
PiperOrigin-RevId: 373888540

0 files changed, 0 insertions, 0 deletions