Retrieve multicast groups information during am: 41540041f1

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Wifi/+/3162692

Change-Id: I69cbc29c10fa5c045e161ccc64ae898000b34855
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

6 files changed, 167 insertions, 1 deletions

diff --git a/service/java/com/android/server/wifi/nl80211/GenericNetlinkMsg.java b/service/java/com/android/server/wifi/nl80211/GenericNetlinkMsg.java
index 82a788777d..b68ee79e96 100644
--- a/service/java/com/android/server/wifi/nl80211/GenericNetlinkMsg.java
+++ b/service/java/com/android/server/wifi/nl80211/GenericNetlinkMsg.java
@@ -110,6 +110,22 @@ public class GenericNetlinkMsg {
     }
 
     /**
+     * Retrieve the inner attributes from a nested attribute.
+     *
+     * @param outerAttribute containing nested inner attributes
+     * @return Inner attributes if valid, or null otherwise.
+     *         Attributes will be represented as an (attributeId -> attribute) map.
+     */
+    public static @Nullable Map<Short, StructNlAttr> getInnerNestedAttributes(
+            @NonNull StructNlAttr outerAttribute) {
+        if (outerAttribute == null) return null;
+        // Outer attribute's payload is a byte buffer containing additional attributes
+        ByteBuffer innerBytes = outerAttribute.getValueAsByteBuffer();
+        if (innerBytes == null) return null;
+        return parseAttributesToMap(innerBytes, innerBytes.remaining());
+    }
+
+    /**
      * Check that this message contains the expected fields.
      */
     public boolean verifyFields(short command, short... attributeIds) {
diff --git a/service/java/com/android/server/wifi/nl80211/NetlinkConstants.java b/service/java/com/android/server/wifi/nl80211/NetlinkConstants.java
index 365616e257..2e56c2dc79 100644
--- a/service/java/com/android/server/wifi/nl80211/NetlinkConstants.java
+++ b/service/java/com/android/server/wifi/nl80211/NetlinkConstants.java
@@ -34,6 +34,14 @@ public class NetlinkConstants {
     public static final short CTRL_ATTR_FAMILY_ID = 1;
     public static final short CTRL_ATTR_FAMILY_NAME = 2;
 
+    public static final short CTRL_ATTR_MCAST_GRP_NAME = 1;
+    public static final short CTRL_ATTR_MCAST_GRP_ID = 2;
+
+    public static final short CTRL_ATTR_MCAST_GROUPS = 7;
+
     // Nl80211 strings for initialization. See kernel/uapi/linux/nl80211.h
     public static final String NL80211_GENL_NAME = "nl80211";
+    public static final String NL80211_MULTICAST_GROUP_SCAN = "scan";
+    public static final String NL80211_MULTICAST_GROUP_REG = "regulatory";
+    public static final String NL80211_MULTICAST_GROUP_MLME = "mlme";
 }
diff --git a/service/java/com/android/server/wifi/nl80211/Nl80211Proxy.java b/service/java/com/android/server/wifi/nl80211/Nl80211Proxy.java
index 78a69c82c4..02ccd5a28f 100644
--- a/service/java/com/android/server/wifi/nl80211/Nl80211Proxy.java
+++ b/service/java/com/android/server/wifi/nl80211/Nl80211Proxy.java
@@ -18,17 +18,24 @@ package com.android.server.wifi.nl80211;
 
 import static com.android.server.wifi.nl80211.NetlinkConstants.CTRL_ATTR_FAMILY_ID;
 import static com.android.server.wifi.nl80211.NetlinkConstants.CTRL_ATTR_FAMILY_NAME;
+import static com.android.server.wifi.nl80211.NetlinkConstants.CTRL_ATTR_MCAST_GROUPS;
+import static com.android.server.wifi.nl80211.NetlinkConstants.CTRL_ATTR_MCAST_GRP_ID;
+import static com.android.server.wifi.nl80211.NetlinkConstants.CTRL_ATTR_MCAST_GRP_NAME;
 import static com.android.server.wifi.nl80211.NetlinkConstants.CTRL_CMD_GETFAMILY;
 import static com.android.server.wifi.nl80211.NetlinkConstants.CTRL_CMD_NEWFAMILY;
 import static com.android.server.wifi.nl80211.NetlinkConstants.GENL_ID_CTRL;
 import static com.android.server.wifi.nl80211.NetlinkConstants.NETLINK_GENERIC;
 import static com.android.server.wifi.nl80211.NetlinkConstants.NL80211_GENL_NAME;
+import static com.android.server.wifi.nl80211.NetlinkConstants.NL80211_MULTICAST_GROUP_MLME;
+import static com.android.server.wifi.nl80211.NetlinkConstants.NL80211_MULTICAST_GROUP_REG;
+import static com.android.server.wifi.nl80211.NetlinkConstants.NL80211_MULTICAST_GROUP_SCAN;
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.system.ErrnoException;
 import android.util.Log;
 
+import com.android.internal.annotations.VisibleForTesting;
 import com.android.net.module.util.netlink.NetlinkUtils;
 import com.android.net.module.util.netlink.StructNlAttr;
 import com.android.net.module.util.netlink.StructNlMsgHdr;
@@ -38,7 +45,9 @@ import java.io.InterruptedIOException;
 import java.net.SocketException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 /**
  * Wrapper around Nl80211 functionality. Allows sending and receiving Nl80211 messages.
@@ -46,11 +55,18 @@ import java.util.List;
 public class Nl80211Proxy {
     private static final String TAG = "Nl80211Proxy";
 
+    private static final String[] sRequiredMulticastGroups = new String[]{
+            NL80211_MULTICAST_GROUP_SCAN,
+            NL80211_MULTICAST_GROUP_REG,
+            NL80211_MULTICAST_GROUP_MLME};
+
     private boolean mIsInitialized;
     private FileDescriptor mNetlinkFd;
     private short mNl80211FamilyId;
     private int mSequenceNumber;
 
+    private Map<String, Integer> mMulticastGroups = new HashMap<>();
+
     public Nl80211Proxy() {}
 
     private int getSequenceNumber() {
@@ -178,7 +194,8 @@ public class Nl80211Proxy {
         request.addAttribute(new StructNlAttr(CTRL_ATTR_FAMILY_NAME, NL80211_GENL_NAME));
 
         GenericNetlinkMsg response = sendMessageAndReceiveResponse(request);
-        if (response == null || !response.verifyFields(CTRL_CMD_NEWFAMILY, CTRL_ATTR_FAMILY_ID)) {
+        if (response == null || !response.verifyFields(CTRL_CMD_NEWFAMILY,
+                CTRL_ATTR_FAMILY_ID, CTRL_ATTR_MCAST_GROUPS)) {
             Log.e(TAG, "Unable to request family information");
             return false;
         }
@@ -189,10 +206,62 @@ public class Nl80211Proxy {
             return false;
         }
         mNl80211FamilyId = familyId;
+
+        Map<String, Integer> multicastGroups =
+                parseMulticastGroupsAttribute(response.getAttribute(CTRL_ATTR_MCAST_GROUPS));
+        for (String groupName : sRequiredMulticastGroups) {
+            if (!multicastGroups.containsKey(groupName)) {
+                Log.e(TAG, "Missing required multicast group. Retrieved=" + multicastGroups);
+                return false;
+            }
+        }
+        mMulticastGroups = multicastGroups;
+
+        Log.i(TAG, "Successfully retrieved Nl80211 family information");
         return true;
     }
 
     /**
+     * Parse the nested multicast groups attribute.
+     *
+     * Expected structure is:
+     *  - ID=CTRL_ATTR_MCAST_GROUPS, VAL={nested}                              ---
+     *     - ID=1, VAL={nested}                              ---                |
+     *        - ID=CTRL_ATTR_MCAST_GRP_NAME, VAL={string}     |   groupAttr     |
+     *        - ID=CTRL_ATTR_MCAST_GRP_ID, VAL={int}         ---                |  rootAttr
+     *     - ID=2, ATTR={nested}                                                |
+     *     - ID=3, ATTR={nested}                                                |
+     *     ...                                                                 ---
+     */
+    @VisibleForTesting
+    protected static @NonNull Map<String, Integer> parseMulticastGroupsAttribute(
+            StructNlAttr rootAttribute) {
+        Map<Short, StructNlAttr> groupAttributes =
+                GenericNetlinkMsg.getInnerNestedAttributes(rootAttribute);
+        if (groupAttributes == null) return new HashMap<>();
+
+        Map<String, Integer> multicastGroups = new HashMap<>();
+        for (StructNlAttr groupAttribute : groupAttributes.values()) {
+            Map<Short, StructNlAttr> groupInnerAttributes =
+                    GenericNetlinkMsg.getInnerNestedAttributes(groupAttribute);
+            if (groupInnerAttributes == null
+                    || !groupInnerAttributes.containsKey(CTRL_ATTR_MCAST_GRP_NAME)
+                    || !groupInnerAttributes.containsKey(CTRL_ATTR_MCAST_GRP_ID)) {
+                continue;
+            }
+
+            String groupName =
+                    groupInnerAttributes.get(CTRL_ATTR_MCAST_GRP_NAME).getValueAsString();
+            Integer groupId = groupInnerAttributes.get(CTRL_ATTR_MCAST_GRP_ID).getValueAsInteger();
+            if (groupName == null || groupId == null) {
+                continue;
+            }
+            multicastGroups.put(groupName, groupId);
+        }
+        return multicastGroups;
+    }
+
+    /**
      * Wrapper to construct an Nl80211 request message.
      *
      * @param command Command ID for this request.
diff --git a/service/tests/wifitests/src/com/android/server/wifi/nl80211/GenericNetlinkMsgTest.java b/service/tests/wifitests/src/com/android/server/wifi/nl80211/GenericNetlinkMsgTest.java
index 1d337cb30a..3c3649661a 100644
--- a/service/tests/wifitests/src/com/android/server/wifi/nl80211/GenericNetlinkMsgTest.java
+++ b/service/tests/wifitests/src/com/android/server/wifi/nl80211/GenericNetlinkMsgTest.java
@@ -146,4 +146,21 @@ public class GenericNetlinkMsgTest {
         assertTrue(invalidSize < buffer.remaining());
         assertNull(GenericNetlinkMsg.parseAttributesToMap(buffer, buffer.remaining()));
     }
+
+    /**
+     * Test that {@link GenericNetlinkMsg#getInnerNestedAttributes(StructNlAttr)} can parse
+     * nested attributes.
+     */
+    @Test
+    public void testGetInnerNestedAttributes() {
+        // Invalid nested attributes are expected to return null
+        assertNull(GenericNetlinkMsg.getInnerNestedAttributes(null));
+        StructNlAttr intAttribute = new StructNlAttr(
+                Nl80211TestUtils.TEST_ATTRIBUTE_ID, Nl80211TestUtils.TEST_ATTRIBUTE_VALUE);
+        assertNull(GenericNetlinkMsg.getInnerNestedAttributes(intAttribute));
+
+        // The multicast groups attribute is nested and should be parsed correctly
+        StructNlAttr nestedAttribute = Nl80211TestUtils.createMulticastGroupsAttribute();
+        assertNotNull(GenericNetlinkMsg.getInnerNestedAttributes(nestedAttribute));
+    }
 }
diff --git a/service/tests/wifitests/src/com/android/server/wifi/nl80211/Nl80211ProxyTest.java b/service/tests/wifitests/src/com/android/server/wifi/nl80211/Nl80211ProxyTest.java
index 75de2d6b54..3c1cf17341 100644
--- a/service/tests/wifitests/src/com/android/server/wifi/nl80211/Nl80211ProxyTest.java
+++ b/service/tests/wifitests/src/com/android/server/wifi/nl80211/Nl80211ProxyTest.java
@@ -19,6 +19,9 @@ package com.android.server.wifi.nl80211;
 import static com.android.server.wifi.nl80211.NetlinkConstants.CTRL_ATTR_FAMILY_ID;
 import static com.android.server.wifi.nl80211.NetlinkConstants.CTRL_CMD_NEWFAMILY;
 import static com.android.server.wifi.nl80211.NetlinkConstants.GENL_ID_CTRL;
+import static com.android.server.wifi.nl80211.NetlinkConstants.NL80211_MULTICAST_GROUP_MLME;
+import static com.android.server.wifi.nl80211.NetlinkConstants.NL80211_MULTICAST_GROUP_REG;
+import static com.android.server.wifi.nl80211.NetlinkConstants.NL80211_MULTICAST_GROUP_SCAN;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
@@ -47,6 +50,7 @@ import org.mockito.quality.Strictness;
 
 import java.io.FileDescriptor;
 import java.nio.ByteBuffer;
+import java.util.Map;
 
 /**
  * Unit tests for {@link Nl80211Proxy}.
@@ -86,6 +90,7 @@ public class Nl80211ProxyTest {
                 CTRL_CMD_NEWFAMILY, GENL_ID_CTRL, (short) 0, 0);
         familyResponse.addAttribute(
                 new StructNlAttr(CTRL_ATTR_FAMILY_ID, TEST_FAMILY_ID));
+        familyResponse.addAttribute(Nl80211TestUtils.createMulticastGroupsAttribute());
         setResponseMessage(familyResponse);
         assertTrue(mDut.initialize());
     }
@@ -133,4 +138,19 @@ public class Nl80211ProxyTest {
         GenericNetlinkMsg message = mDut.createNl80211Request(Nl80211TestUtils.TEST_COMMAND);
         assertEquals(TEST_FAMILY_ID, message.nlHeader.nlmsg_type);
     }
+
+    /**
+     * Test that {@link Nl80211Proxy#parseMulticastGroupsAttribute(StructNlAttr)} can parse
+     * a valid multicast groups attribute.
+     */
+    @Test
+    public void testParseMulticastGroupsAttribute() {
+        StructNlAttr multicastGroupsAttribute = Nl80211TestUtils.createMulticastGroupsAttribute();
+        Map<String, Integer> parsedMulticastGroups =
+                Nl80211Proxy.parseMulticastGroupsAttribute(multicastGroupsAttribute);
+        // Result is expected to contain all the required groups
+        assertTrue(parsedMulticastGroups.containsKey(NL80211_MULTICAST_GROUP_SCAN));
+        assertTrue(parsedMulticastGroups.containsKey(NL80211_MULTICAST_GROUP_REG));
+        assertTrue(parsedMulticastGroups.containsKey(NL80211_MULTICAST_GROUP_MLME));
+    }
 }
diff --git a/service/tests/wifitests/src/com/android/server/wifi/nl80211/Nl80211TestUtils.java b/service/tests/wifitests/src/com/android/server/wifi/nl80211/Nl80211TestUtils.java
index 09f9bd9c18..b9c1d5011b 100644
--- a/service/tests/wifitests/src/com/android/server/wifi/nl80211/Nl80211TestUtils.java
+++ b/service/tests/wifitests/src/com/android/server/wifi/nl80211/Nl80211TestUtils.java
@@ -16,6 +16,13 @@
 
 package com.android.server.wifi.nl80211;
 
+import static com.android.server.wifi.nl80211.NetlinkConstants.CTRL_ATTR_MCAST_GROUPS;
+import static com.android.server.wifi.nl80211.NetlinkConstants.CTRL_ATTR_MCAST_GRP_ID;
+import static com.android.server.wifi.nl80211.NetlinkConstants.CTRL_ATTR_MCAST_GRP_NAME;
+import static com.android.server.wifi.nl80211.NetlinkConstants.NL80211_MULTICAST_GROUP_MLME;
+import static com.android.server.wifi.nl80211.NetlinkConstants.NL80211_MULTICAST_GROUP_REG;
+import static com.android.server.wifi.nl80211.NetlinkConstants.NL80211_MULTICAST_GROUP_SCAN;
+
 import com.android.net.module.util.netlink.StructNlAttr;
 import com.android.net.module.util.netlink.StructNlMsgHdr;
 
@@ -62,4 +69,33 @@ public class Nl80211TestUtils {
         }
         return msg;
     }
+
+    private static void removeNestedAttributeFlag(StructNlAttr attribute) {
+        // Flag is set by default by the StructNlAttr nested attribute constructor,
+        // but is not set in nested attributes received from Nl80211
+        attribute.nla_type ^= StructNlAttr.NLA_F_NESTED;
+    }
+
+    private static StructNlAttr createMulticastGroupAttribute(
+            int index, String groupName, int groupId) {
+        StructNlAttr nameAttr = new StructNlAttr(CTRL_ATTR_MCAST_GRP_NAME, groupName);
+        StructNlAttr idAttr = new StructNlAttr(CTRL_ATTR_MCAST_GRP_ID, groupId);
+        StructNlAttr multicastGroupAttr = new StructNlAttr((short) index, nameAttr, idAttr);
+        removeNestedAttributeFlag(multicastGroupAttr);
+        return multicastGroupAttr;
+    }
+
+    /**
+     * Create a valid multicast groups attribute. Contains a nested inner attribute for each of
+     * the required multicast groups.
+     */
+    public static StructNlAttr createMulticastGroupsAttribute() {
+        StructNlAttr scanAttr = createMulticastGroupAttribute(1, NL80211_MULTICAST_GROUP_SCAN, 10);
+        StructNlAttr regAttr = createMulticastGroupAttribute(2, NL80211_MULTICAST_GROUP_REG, 11);
+        StructNlAttr mlmeAttr = createMulticastGroupAttribute(3, NL80211_MULTICAST_GROUP_MLME, 12);
+        StructNlAttr multicastGroupsAttr =
+                new StructNlAttr(CTRL_ATTR_MCAST_GROUPS, scanAttr, regAttr, mlmeAttr);
+        removeNestedAttributeFlag(multicastGroupsAttr);
+        return multicastGroupsAttr;
+    }
 }