tree 89f0e531781bf69e81a32943d59407de998550bf
parent 727544c0940c5844160c6a2f4bcecf0c67956033
author nuccachen <nuccachen@google.com> 1531822043 +0800
committer Hungming Chen <nuccachen@google.com> 1545030605 +0800

Synthesize DNS64 prefix in netd

Synthesize DNS64 prefix with IPv4 dns query result in the following
conditions:
1. If specify address family to IPv6 and no IPv6 addresses result is
   obtained, then if IPv4 addresses result could be obtained
2. If address family is unspecified and query results are all IPv4
   addresses

Test: built, flashed, booted
      system/netd/tests/runtests.sh passes
Bug: 78545619

Change-Id: Ia7c5963c054772f8c95b95849282e9d9d5761515