[RFCLAT#5] remove the unnecessary tun fd, socket handler and socket opt cleanup
- Closing tun fd is not necessary because any open fds are closed
when a process exits
- Closing socket fds are not necessary because any open fds are
closed when a process exits
- Applying IPV6_LEAVE_ANYCAST is not necessary because the setting is
stored with the socket and removed when it is closed
See addrconf_ifdown, ipv6_ac_destroy_dev
Bug: 212345928
Test: atest clatd_test and manual test
1. Connect to ipv6-only wifi.
2. Try IPv4 traffic.
$ ping 8.8.8.8
Change-Id: I8002c1adef208f5dcd6665fecee0df6236159f88
1 file changed