tree cefd20c563d23c4eec49856654817b97bffd731d
parent d50b3ed6c714b8025c9c135951f2a0a89e0ac702
author Lorenzo Colitti <lorenzo@google.com> 1581609995 +0900
committer Lorenzo Colitti <lorenzo@google.com> 1582113043 +0900

Tethering offload: add/remove IPv6 forwarding rules on ND events.

Use IpNeighborMonitor to listen for ND cache events on the
downstream interface, and push downstream IPv6 fowarding rules
to netd.

Rules are pushed when:
- IPv6 neighbours appear/disappear on the downstream interface.
- The upstream changes.

Test: new unit test
Change-Id: I7b01ba179a4d6bb248fd6c4994e48800613a4efa