commit 5dafb0e92cef0e60fa83a8056f59fc93f5bfd572
author Hungming Chen <nuccachen@google.com> Wed Nov 24 20:19:43 2021 +0800
committer Hungming Chen <nuccachen@google.com> Thu Dec 30 22:54:35 2021 +0800
tree 31c5bf547bd640a7fce8fd6f515be7b1f8df2090
parent 06367f38702a763777652aff8f2ac50c57772dbb

[RFCLAT#3] Move the tun interface setup from clatd to netd

This is a preparation for reducing the clatd required capability.

Function change:
- configure_tun_ip(), detect_mtu() are moved to netd/ClatdController
- move Clatd_Config.ipv4_local_subnet setup from configure_tun_ip() to
  main() because configure_tun_ip() is removed. translate.c needs
  the clat IPv4 address for 4->6, 6>->4 address translation.

Bug: 212345928
Test: manual test
1. Connect to ipv6-only wifi.
2. Try IPv4 traffic.
   $ ping 8.8.8.8

Change-Id: Ibf80b17865f414f329ab7c50836595f3b99360e2