commit 57d480d2b425ef20d8b6f84abd4e9e3209fa9422
author Lorenzo Colitti <lorenzo@google.com> Sun Feb 09 10:35:38 2014 +0900
committer Lorenzo Colitti <lorenzo@google.com> Sat Feb 22 12:46:06 2014 +0900
tree 1d4d53278970b0681042e4f10ef44c1c5334bc5f
parent 07f0265830fcae2632159e9993b93a161d7ea23b

Support translating fragmented packets.

Bug: 11542311
Change-Id: I14a20b9ac669cdb5927f6ac26147bb0109099497

clatd.c

diff --git a/clatd.c b/clatd.c
index 3ab2371..a89c588 100644
--- a/clatd.c
+++ b/clatd.c
@@ -51,6 +51,9 @@
 #define DEVICENAME6 "clat"
 #define DEVICENAME4 "clat4"
 
+/* 40 bytes IPv6 header - 20 bytes IPv4 header + 8 bytes fragment header */
+#define MTU_DELTA 28
+
 int forwarding_fd = -1;
 volatile sig_atomic_t running = 1;
 
@@ -271,8 +274,9 @@
     Global_Clatd_Config.mtu = 1280;
   }
 
-  if(Global_Clatd_Config.ipv4mtu <= 0 || (Global_Clatd_Config.ipv4mtu > Global_Clatd_Config.mtu - 20)) {
-    Global_Clatd_Config.ipv4mtu = Global_Clatd_Config.mtu-20;
+  if(Global_Clatd_Config.ipv4mtu <= 0 ||
+     Global_Clatd_Config.ipv4mtu > Global_Clatd_Config.mtu - MTU_DELTA) {
+    Global_Clatd_Config.ipv4mtu = Global_Clatd_Config.mtu - MTU_DELTA;
     logmsg(ANDROID_LOG_WARN,"ipv4mtu now set to = %d",Global_Clatd_Config.ipv4mtu);
   }