Don't enumerate interfaces if no interfaces were found.
When dnsmasq receives a list of interfaces, but cannot find any
of them (e.g., because they have all been deleted), it enters the
default non-Android codepath where it listens on all interfaces.
Then, if any of the interfaces on the system is deleted while it
is starting up on all interfaces, it can enter a codepath where
it gets stuck for 20(!) seconds for DAD to complete on an
interface that no longer exists.
Bug: 152695206
Test: new test coverage in netd_integration_test
Merged-In: Id9289e5a22dddceb53782d75e3caa4f6a88c6fb1
Change-Id: Id9289e5a22dddceb53782d75e3caa4f6a88c6fb1
1 file changed
