tree ec503d75fa873763ff0b8ad6d95cd51e0b142dc3
parent 1c2f79705fc54d914aafbb318fa4e7fd7fb327fb
author Lorenzo Colitti <lorenzo@google.com> 1644797127 +0900
committer Xiao Ma <xiaom@google.com> 1647524554 +0000

Add a method to create a TAP interface without bringing it up.

In S, the behaviour of createTunInterface and createTapInterface
changed so that they bring up the interface before returning it.
This makes it difficult to test code that brings interfaces up
itself, such as IpClient or EthernetManager, because the tests
cannot predict whether that code will see the interface up
or not. This leads to flaky tests and can even make it impossible
to reliably test some behaviour.

Add a method that allows the caller to specify whether to bring
up the interface or not.

Test: new codepath tested by other CL in topic
Test: existing codepaths already well-covered
Change-Id: I0f7698f4dad132f201db4203e65a78c6af564ab2