More multicast fixes.

1. Make native code properly set network interface indexes that are used for
   new-style multicast socket options.
2. For IP_MULTICAST_IF, check that the address is IPv4, not the socket.
3. Remove a @KnownFailure annotation for a test that now passes.

This removes one test error and changes it into a more benign failure. The
remaining test failures seem to be due to Linux bening permissive about which
interfaces you can receive multicast traffic on, which is probably good enough
for now.

Change-Id: Id1fddee338addcfce821672b983485c7dd4983d4

3 files changed, 6 insertions, 5 deletions

diff --git a/luni/src/main/native/java_net_NetworkInterface.c b/luni/src/main/native/java_net_NetworkInterface.c
index 379ccdf..db6d503 100644
--- a/luni/src/main/native/java_net_NetworkInterface.c
+++ b/luni/src/main/native/java_net_NetworkInterface.c
@@ -546,8 +546,9 @@ int sockGetNetworkInterfaces(struct NetworkInterfaceArray_struct * array) {
             /* since this function can return multiple entries for the same name, only do it for the first one with any given name */
             if((NULL == lastName) || (strncmp(lastName, ifc.ifc_req[counter].ifr_name, IFNAMSIZ) != 0)) {
 
-                /* get the index for the interface.  This is only truely necessary on platforms that support IPV6 */
-                interfaces[currentAdapterIndex].index = 0;
+                /* get the index for the interface */
+                interfaces[currentAdapterIndex].index =
+                        ifc.ifc_req[counter].ifr_ifindex;
                 /* get the name and display name for the adapter */
                 /* there only seems to be one name so use it for both the name and the display name */
                 nameLength = strlen(ifc.ifc_req[counter].ifr_name);
diff --git a/luni/src/main/native/org_apache_harmony_luni_platform_OSNetworkSystem.cpp b/luni/src/main/native/org_apache_harmony_luni_platform_OSNetworkSystem.cpp
index 339c62c..7b6023a 100644
--- a/luni/src/main/native/org_apache_harmony_luni_platform_OSNetworkSystem.cpp
+++ b/luni/src/main/native/org_apache_harmony_luni_platform_OSNetworkSystem.cpp
@@ -3316,8 +3316,9 @@ static void osNetworkSystem_setSocketOptionImpl(JNIEnv* env, jclass clazz,
             if ((anOption >> 16) & BROKEN_MULTICAST_IF) {
                 return;
             }
-            // This call is IPv4 only.
-            if (getSocketAddressFamily(handle) != AF_INET) {
+            // This call is IPv4 only. The socket may be IPv6, but the address
+            // that identifies the interface to join must be an IPv4 address.
+            if (sockVal.ss_family != AF_INET) {
                 throwSocketException(env, SOCKERR_BADAF);
                 return;
             }
diff --git a/luni/src/test/java/tests/api/java/net/MulticastSocketTest.java b/luni/src/test/java/tests/api/java/net/MulticastSocketTest.java
index 997055b..1429063 100644
--- a/luni/src/test/java/tests/api/java/net/MulticastSocketTest.java
+++ b/luni/src/test/java/tests/api/java/net/MulticastSocketTest.java
@@ -1099,7 +1099,6 @@ public class MulticastSocketTest extends SocketTestCase {
         method = "setNetworkInterface",
         args = {java.net.NetworkInterface.class}
     )
-    @KnownFailure("No interfaces if there's no debugger connected")
     public void test_setNetworkInterfaceLjava_net_NetworkInterface() 
                                     throws IOException, InterruptedException {
         String msg = null;