Never use a statically-configured IID on wifi.android-cts-5.1_r9android-cts-5.1_r8android-cts-5.1_r7android-cts-5.1_r6android-cts-5.1_r5android-cts-5.1_r4android-cts-5.1_r3android-cts-5.1_r28android-cts-5.1_r27android-cts-5.1_r26android-cts-5.1_r25android-cts-5.1_r24android-cts-5.1_r23android-cts-5.1_r22android-cts-5.1_r21android-cts-5.1_r20android-cts-5.1_r2android-cts-5.1_r19android-cts-5.1_r18android-cts-5.1_r17android-cts-5.1_r16android-cts-5.1_r15android-cts-5.1_r14android-cts-5.1_r13android-cts-5.1_r10android-cts-5.1_r1android-5.1.1_r9android-5.1.1_r8android-5.1.1_r7android-5.1.1_r6android-5.1.1_r5android-5.1.1_r4android-5.1.1_r38android-5.1.1_r37android-5.1.1_r36android-5.1.1_r35android-5.1.1_r34android-5.1.1_r33android-5.1.1_r30android-5.1.1_r3android-5.1.1_r29android-5.1.1_r28android-5.1.1_r26android-5.1.1_r25android-5.1.1_r24android-5.1.1_r23android-5.1.1_r22android-5.1.1_r20android-5.1.1_r2android-5.1.1_r19android-5.1.1_r18android-5.1.1_r17android-5.1.1_r16android-5.1.1_r15android-5.1.1_r14android-5.1.1_r13android-5.1.1_r12android-5.1.1_r10android-5.1.1_r1android-5.1.0_r5android-5.1.0_r4android-5.1.0_r3android-5.1.0_r1lollipop-mr1-wfc-releaselollipop-mr1-releaselollipop-mr1-fi-releaselollipop-mr1-devlollipop-mr1-cts-release

Bug: 12111730
Change-Id: I062d81f2b65e6e89baae0f840cbd673f8051d523

1 files changed, 14 insertions, 1 deletions

diff --git a/config.c b/config.c
index de8a26f..b147868 100644
--- a/config.c
+++ b/config.c
@@ -25,6 +25,7 @@
 #include <unistd.h>
 
 #include <cutils/config_utils.h>
+#include <netutils/ifc.h>
 
 #include "config.h"
 #include "dns64.h"
@@ -276,7 +277,7 @@ in_addr_t config_select_ipv4_address(const struct in_addr *ip, int16_t prefixlen
 void config_generate_local_ipv6_subnet(struct in6_addr *interface_ip) {
   int i;
 
-  if (IN6_IS_ADDR_UNSPECIFIED(&Global_Clatd_Config.ipv6_host_id)) {
+  if (Global_Clatd_Config.use_dynamic_iid) {
     /* Generate a random interface ID. */
     gen_random_iid(interface_ip,
                    &Global_Clatd_Config.ipv4_local_subnet,
@@ -300,6 +301,7 @@ int read_config(const char *file, const char *uplink_interface, const char *plat
         unsigned net_id) {
   cnode *root = config_node("", "");
   void *tmp_ptr = NULL;
+  unsigned flags;
 
   if(!root) {
     logmsg(ANDROID_LOG_FATAL,"out of memory");
@@ -358,6 +360,17 @@ int read_config(const char *file, const char *uplink_interface, const char *plat
   if (!config_item_ip6(root, "ipv6_host_id", "::", &Global_Clatd_Config.ipv6_host_id))
     goto failed;
 
+  /* In order to prevent multiple devices attempting to use the same clat address, never use a
+     statically-configured interface ID on a broadcast interface such as wifi. */
+  if (!IN6_IS_ADDR_UNSPECIFIED(&Global_Clatd_Config.ipv6_host_id)) {
+    ifc_init();
+    ifc_get_info(Global_Clatd_Config.default_pdp_interface, NULL, NULL, &flags);
+    ifc_close();
+    Global_Clatd_Config.use_dynamic_iid = (flags & IFF_BROADCAST) != 0;
+  } else {
+    Global_Clatd_Config.use_dynamic_iid = 1;
+  }
+
   return 1;
 
 failed: