Start DHCPv6 PD when no available IPv6 addresses after timeout.
To prevent DHCPv6 PD from potentially disrupting existing IPv6 networks,
only start DHCPv6 PD when device has only an IPv6 default route and no
addresses except IPv6 link-local address after a timeout (5s), basically
it indicates that current network has a clear signal that cannot provide
autoconf. Otherwise, once we start DHCPv6 PD, it may exhaust all
available IPv6 prefixes on that network.
Bug: 260934173
Test: atest NetworkStackIntegrationTests
Change-Id: I2a88b544163385fc0bbfb6168af336a7fddc16d9
2 files changed
