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

main.c

diff --git a/main.c b/main.c
index 96fbd0d..fe88dfd 100644
--- a/main.c
+++ b/main.c
@@ -145,12 +145,17 @@
     exit(1);
   }
 
+  if (!v4_addr || !inet_pton(AF_INET, v4_addr, &Global_Clatd_Config.ipv4_local_subnet.s_addr)) {
+    logmsg(ANDROID_LOG_FATAL, "Invalid IPv4 address %s", v4_addr);
+    exit(1);
+  }
+
   logmsg(ANDROID_LOG_INFO, "Starting clat version %s on %s mark=%s plat=%s v4=%s v6=%s",
          CLATD_VERSION, uplink_interface, mark_str ? mark_str : "(none)",
          plat_prefix ? plat_prefix : "(none)", v4_addr ? v4_addr : "(none)",
          v6_addr ? v6_addr : "(none)");
 
-  configure_interface(uplink_interface, plat_prefix, v4_addr, v6_addr, &tunnel, mark);
+  configure_interface(uplink_interface, plat_prefix, v6_addr, &tunnel);
 
   // run under a regular user with no capabilities
   drop_root_and_caps();