8021372: NetworkInterface.getNetworkInterfaces() returns duplicate hardware address

Summary: amended src/windows/native/java/net/NetworkInterface_winXP.c to "properly" handle Ipv6IfIndex
Reviewed-by: chegar, dsamersoff

src/windows/native/java/net/NetworkInterface_winXP.c

 /*
- * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -82,7 +82,6 @@ static int getAdapters (JNIEnv *env, IP_ADAPTER_ADDRESSES **adapters) {
     IP_ADAPTER_ADDRESSES *adapterInfo;
     ULONG len;
     adapterInfo = (IP_ADAPTER_ADDRESSES *)malloc (bufsize);
-
     if (adapterInfo == NULL) {
         JNU_ThrowByName(env, "java/lang/OutOfMemoryError", "Native heap allocation failure");
         return -1;
@@ -160,8 +159,12 @@ IP_ADAPTER_ADDRESSES *getAdapter (JNIEnv *env,  jint index) {
     ptr = adapterInfo;
     ret = NULL;
     while (ptr != NULL) {
-      // IPv4 interface
-      if (ptr->Ipv6IfIndex == index) {
+      // in theory the IPv4 index and the IPv6 index can be the same
+      // where an interface is enabled for v4 and v6
+      // IfIndex == 0 IPv4 not available on this interface
+      // Ipv6IfIndex == 0 IPv6 not available on this interface
+      if (((ptr->IfIndex != 0)&&(ptr->IfIndex == index)) ||
+          ((ptr->Ipv6IfIndex !=0) && (ptr->Ipv6IfIndex == index))) {
         ret = (IP_ADAPTER_ADDRESSES *) malloc(sizeof(IP_ADAPTER_ADDRESSES));
         if (ret == NULL) {
             free(adapterInfo);
@@ -172,6 +175,7 @@ IP_ADAPTER_ADDRESSES *getAdapter (JNIEnv *env,  jint index) {
         //copy the memory and break out of the while loop.
         memcpy(ret, ptr, sizeof(IP_ADAPTER_ADDRESSES));
         break;
+
       }
       ptr=ptr->Next;
     }
@@ -192,7 +196,6 @@ int getAllInterfacesAndAddresses (JNIEnv *env, netif **netifPP)
     int tun=0, net=0;
 
     *netifPP = NULL;
-
    /*
     * Get the IPv4 interfaces. This information is the same
     * as what previous JDK versions would return.
@@ -264,7 +267,7 @@ int getAllInterfacesAndAddresses (JNIEnv *env, netif **netifPP)
                          * set the index to the IPv6 index and add the
                          * IPv6 addresses
                          */
-                        nif->index = ptr->Ipv6IfIndex;
+                        nif->ipv6Index = ptr->Ipv6IfIndex;
                         c = getAddrsFromAdapter(ptr, &nif->addrs);
                         nif->naddrs += c;
                         break;
@@ -309,6 +312,9 @@ int getAllInterfacesAndAddresses (JNIEnv *env, netif **netifPP)
                         strcpy (nif->name, newname);
                         wcscpy ((PWCHAR)nif->displayName, ptr->FriendlyName);
                         nif->dNameIsUnicode = TRUE;
+
+                        // the java.net.NetworkInterface abstraction only has index
+                        // so the Ipv6IfIndex needs to map onto index
                         nif->index = ptr->Ipv6IfIndex;
                         nif->ipv6Index = ptr->Ipv6IfIndex;
                         nif->hasIpv6Address = TRUE;
@@ -487,7 +493,6 @@ static jobject createNetworkInterfaceXP(JNIEnv *env, netif *ifs)
     (*env)->SetObjectField(env, netifObj, ni_nameID, name);
     (*env)->SetObjectField(env, netifObj, ni_displayNameID, displayName);
     (*env)->SetIntField(env, netifObj, ni_indexID, ifs->index);
-
     /*
      * Get the IP addresses for this interface if necessary
      * Note that 0 is a valid number of addresses.

test/java/net/NetworkInterface/UniqueMacAddressesTest.java

+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.net.InetAddress;
+import java.net.NetworkInterface;
+import java.net.SocketException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Enumeration;
+import java.util.List;
+
+
+/*
+ * @test
+ * @bug 8021372
+ * @summary Tests that the MAC addresses returned by NetworkInterface.getNetworkInterfaces are unique for each adapter.
+ *
+ */
+public class UniqueMacAddressesTest {
+
+    public static void main(String[] args) throws Exception {
+        new UniqueMacAddressesTest().execute();
+        System.out.println("UniqueMacAddressesTest: OK");
+    }
+
+    public UniqueMacAddressesTest() {
+        System.out.println("UniqueMacAddressesTest: start ");
+    }
+
+    public void execute() throws Exception {
+        Enumeration<NetworkInterface> networkInterfaces;
+        boolean areMacAddressesUnique = false;
+        List<NetworkInterface> networkInterfaceList = new ArrayList<NetworkInterface>();
+            networkInterfaces = NetworkInterface.getNetworkInterfaces();
+
+        // build a list of NetworkInterface objects to test MAC address
+        // uniqueness
+        createNetworkInterfaceList(networkInterfaces, networkInterfaceList);
+        areMacAddressesUnique = checkMacAddressesAreUnique(networkInterfaceList);
+        if (!areMacAddressesUnique) {
+            throw new RuntimeException("mac address uniqueness test failed");
+        }
+    }
+
+    private boolean checkMacAddressesAreUnique (
+            List<NetworkInterface> networkInterfaces) throws Exception {
+        boolean uniqueMacAddresses = true;
+        for (NetworkInterface networkInterface : networkInterfaces) {
+            for (NetworkInterface comparisonNetIf : networkInterfaces) {
+                System.out.println("Comparing netif "
+                        + networkInterface.getName() + " and netif "
+                        + comparisonNetIf.getName());
+                if (testMacAddressesEqual(networkInterface, comparisonNetIf)) {
+                    uniqueMacAddresses = false;
+                    break;
+                }
+            }
+            if (uniqueMacAddresses != true)
+                break;
+        }
+        return uniqueMacAddresses;
+    }
+
+    private boolean testMacAddressesEqual(NetworkInterface netIf1,
+            NetworkInterface netIf2) throws Exception {
+
+        byte[] rawMacAddress1 = null;
+        byte[] rawMacAddress2 = null;
+        boolean macAddressesEqual = false;
+        if (!netIf1.getName().equals(netIf2.getName())) {
+            System.out.println("compare hardware addresses "
+                +  createMacAddressString(netIf1) + " and " + createMacAddressString(netIf2));
+            rawMacAddress1 = netIf1.getHardwareAddress();
+            rawMacAddress2 = netIf2.getHardwareAddress();
+            macAddressesEqual = Arrays.equals(rawMacAddress1, rawMacAddress2);
+        } else {
+            // same interface
+            macAddressesEqual = false;
+        }
+        return macAddressesEqual;
+    }
+
+    private String createMacAddressString (NetworkInterface netIf) throws Exception {
+        byte[] macAddr = netIf.getHardwareAddress();
+        StringBuilder sb =  new StringBuilder();
+        if (macAddr != null) {
+            for (int i = 0; i < macAddr.length; i++) {
+                sb.append(String.format("%02X%s", macAddr[i],
+                        (i < macAddr.length - 1) ? "-" : ""));
+            }
+        }
+        return sb.toString();
+    }
+
+    private void createNetworkInterfaceList(Enumeration<NetworkInterface> nis,
+            List<NetworkInterface> networkInterfaceList) throws Exception {
+        byte[] macAddr = null;
+        NetworkInterface netIf = null;
+        while (nis.hasMoreElements()) {
+            netIf = (NetworkInterface) nis.nextElement();
+            macAddr = netIf.getHardwareAddress();
+            if (macAddr != null) {
+                System.out
+                        .println("Adding NetworkInterface " + netIf.getName());
+                networkInterfaceList.add(netIf);
+            }
+        }
+    }
+}