diff --git a/staticlibs/device/com/android/net/module/util/netlink/NetlinkConstants.java b/staticlibs/device/com/android/net/module/util/netlink/NetlinkConstants.java
index 44c51d8..ad7a4d7 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/NetlinkConstants.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/NetlinkConstants.java
@@ -151,6 +151,9 @@
     public static final int RTNLGRP_ND_USEROPT = 20;
     public static final int RTMGRP_ND_USEROPT = 1 << (RTNLGRP_ND_USEROPT - 1);
 
+    // Netlink family
+    public static final short RTNL_FAMILY_IP6MR = 129;
+
     // Device flags.
     public static final int IFF_UP       = 1 << 0;
     public static final int IFF_LOWER_UP = 1 << 16;
diff --git a/staticlibs/device/com/android/net/module/util/netlink/RtNetlinkRouteMessage.java b/staticlibs/device/com/android/net/module/util/netlink/RtNetlinkRouteMessage.java
index 9acac69..c21e25f 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/RtNetlinkRouteMessage.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/RtNetlinkRouteMessage.java
@@ -19,11 +19,15 @@
 import static android.system.OsConstants.AF_INET;
 import static android.system.OsConstants.AF_INET6;
 
+import static android.system.OsConstants.NETLINK_ROUTE;
 import static com.android.net.module.util.NetworkStackConstants.IPV4_ADDR_ANY;
 import static com.android.net.module.util.NetworkStackConstants.IPV6_ADDR_ANY;
+import static com.android.net.module.util.netlink.NetlinkConstants.hexify;
+import static com.android.net.module.util.netlink.NetlinkConstants.RTNL_FAMILY_IP6MR;
 
 import android.annotation.SuppressLint;
 import android.net.IpPrefix;
+import android.net.RouteInfo;
 import android.system.OsConstants;
 
 import androidx.annotation.NonNull;
@@ -34,6 +38,9 @@
 import java.net.Inet6Address;
 import java.net.InetAddress;
 import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.IntBuffer;
+import java.util.Arrays;
 
 /**
  * A NetlinkMessage subclass for rtnetlink route messages.
@@ -49,31 +56,62 @@
  */
 public class RtNetlinkRouteMessage extends NetlinkMessage {
     public static final short RTA_DST           = 1;
+    public static final short RTA_SRC           = 2;
+    public static final short RTA_IIF           = 3;
     public static final short RTA_OIF           = 4;
     public static final short RTA_GATEWAY       = 5;
     public static final short RTA_CACHEINFO     = 12;
+    public static final short RTA_EXPIRES       = 23;
 
-    private int mIfindex;
+    public static final short RTNH_F_UNRESOLVED = 32;   // The multicast route is unresolved
+
+    public static final String TAG = "NetlinkRouteMessage";
+
+    // For multicast routes, whether the route is resolved or unresolved
+    private boolean mIsResolved;
+    // The interface index for incoming interface, this is set for multicast
+    // routes, see common/net/ipv4/ipmr_base.c mr_fill_mroute
+    private int mIifIndex; // Incoming interface of a route, for resolved multicast routes
+    private int mOifIndex;
     @NonNull
     private StructRtMsg mRtmsg;
-    @NonNull
-    private IpPrefix mDestination;
+    @Nullable
+    private IpPrefix mSource; // Source address of a route, for all multicast routes
+    @Nullable
+    private IpPrefix mDestination; // Destination of a route, can be null for RTM_GETROUTE
     @Nullable
     private InetAddress mGateway;
     @Nullable
     private StructRtaCacheInfo mRtaCacheInfo;
+    private long mSinceLastUseMillis; // Milliseconds since the route was used,
+                                      // for resolved multicast routes
 
-    private RtNetlinkRouteMessage(StructNlMsgHdr header) {
+    public RtNetlinkRouteMessage(StructNlMsgHdr header, StructRtMsg rtMsg) {
         super(header);
-        mRtmsg = null;
+        mRtmsg = rtMsg;
+        mSource = null;
         mDestination = null;
         mGateway = null;
-        mIfindex = 0;
+        mIifIndex = 0;
+        mOifIndex = 0;
         mRtaCacheInfo = null;
+        mSinceLastUseMillis = -1;
+    }
+
+    /**
+     * Returns if the route is resolved. This is always true for unicast,
+     * and may be false only for multicast routes.
+     */
+    public boolean isResolved() {
+        return mIsResolved;
+    }
+
+    public int getIifIndex() {
+        return mIifIndex;
     }
 
     public int getInterfaceIndex() {
-        return mIfindex;
+        return mOifIndex;
     }
 
     @NonNull
@@ -86,6 +124,14 @@
         return mDestination;
     }
 
+    /**
+     * Get source address of a route. This is for multicast routes.
+     */
+    @NonNull
+    public IpPrefix getSource() {
+        return mSource;
+    }
+
     @Nullable
     public InetAddress getGateway() {
         return mGateway;
@@ -97,6 +143,18 @@
     }
 
     /**
+     * RTA_EXPIRES attribute returned by kernel to indicate the clock ticks
+     * from the route was last used to now, converted to milliseconds.
+     * This is set for multicast routes.
+     *
+     * Note that this value is not updated with the passage of time. It always
+     * returns the value that was read when the netlink message was parsed.
+     */
+    public long getSinceLastUseMillis() {
+        return mSinceLastUseMillis;
+    }
+
+    /**
      * Check whether the address families of destination and gateway match rtm_family in
      * StructRtmsg.
      *
@@ -107,7 +165,8 @@
     private static boolean matchRouteAddressFamily(@NonNull final InetAddress address,
             int family) {
         return ((address instanceof Inet4Address) && (family == AF_INET))
-                || ((address instanceof Inet6Address) && (family == AF_INET6));
+                || ((address instanceof Inet6Address) &&
+                        (family == AF_INET6 || family == RTNL_FAMILY_IP6MR));
     }
 
     /**
@@ -121,11 +180,11 @@
     @Nullable
     public static RtNetlinkRouteMessage parse(@NonNull final StructNlMsgHdr header,
             @NonNull final ByteBuffer byteBuffer) {
-        final RtNetlinkRouteMessage routeMsg = new RtNetlinkRouteMessage(header);
-
-        routeMsg.mRtmsg = StructRtMsg.parse(byteBuffer);
-        if (routeMsg.mRtmsg == null) return null;
+        final StructRtMsg rtmsg = StructRtMsg.parse(byteBuffer);
+        if (rtmsg == null) return null;
+        final RtNetlinkRouteMessage routeMsg = new RtNetlinkRouteMessage(header, rtmsg);
         int rtmFamily = routeMsg.mRtmsg.family;
+        routeMsg.mIsResolved = ((routeMsg.mRtmsg.flags & RTNH_F_UNRESOLVED) == 0);
 
         // RTA_DST
         final int baseOffset = byteBuffer.position();
@@ -139,12 +198,24 @@
             routeMsg.mDestination = new IpPrefix(destination, routeMsg.mRtmsg.dstLen);
         } else if (rtmFamily == AF_INET) {
             routeMsg.mDestination = new IpPrefix(IPV4_ADDR_ANY, 0);
-        } else if (rtmFamily == AF_INET6) {
+        } else if (rtmFamily == AF_INET6 || rtmFamily == RTNL_FAMILY_IP6MR) {
             routeMsg.mDestination = new IpPrefix(IPV6_ADDR_ANY, 0);
         } else {
             return null;
         }
 
+        // RTA_SRC
+        byteBuffer.position(baseOffset);
+        nlAttr = StructNlAttr.findNextAttrOfType(RTA_SRC, byteBuffer);
+        if (nlAttr != null) {
+            final InetAddress source = nlAttr.getValueAsInetAddress();
+            // If the RTA_SRC attribute is malformed, return null.
+            if (source == null) return null;
+            // If the address family of destination doesn't match rtm_family, return null.
+            if (!matchRouteAddressFamily(source, rtmFamily)) return null;
+            routeMsg.mSource = new IpPrefix(source, routeMsg.mRtmsg.srcLen);
+        }
+
         // RTA_GATEWAY
         byteBuffer.position(baseOffset);
         nlAttr = StructNlAttr.findNextAttrOfType(RTA_GATEWAY, byteBuffer);
@@ -156,6 +227,17 @@
             if (!matchRouteAddressFamily(routeMsg.mGateway, rtmFamily)) return null;
         }
 
+        // RTA_IIF
+        byteBuffer.position(baseOffset);
+        nlAttr = StructNlAttr.findNextAttrOfType(RTA_IIF, byteBuffer);
+        if (nlAttr != null) {
+            Integer iifInteger = nlAttr.getValueAsInteger();
+            if (iifInteger == null) {
+                return null;
+            }
+            routeMsg.mIifIndex = iifInteger;
+        }
+
         // RTA_OIF
         byteBuffer.position(baseOffset);
         nlAttr = StructNlAttr.findNextAttrOfType(RTA_OIF, byteBuffer);
@@ -164,7 +246,7 @@
             // the interface index to a name themselves. This may not succeed or may be
             // incorrect, because the interface might have been deleted, or even deleted
             // and re-added with a different index, since the netlink message was sent.
-            routeMsg.mIfindex = nlAttr.getValueAsInt(0 /* 0 isn't a valid ifindex */);
+            routeMsg.mOifIndex = nlAttr.getValueAsInt(0 /* 0 isn't a valid ifindex */);
         }
 
         // RTA_CACHEINFO
@@ -174,33 +256,59 @@
             routeMsg.mRtaCacheInfo = StructRtaCacheInfo.parse(nlAttr.getValueAsByteBuffer());
         }
 
+        // RTA_EXPIRES
+        byteBuffer.position(baseOffset);
+        nlAttr = StructNlAttr.findNextAttrOfType(RTA_EXPIRES, byteBuffer);
+        if (nlAttr != null) {
+            final Long sinceLastUseCentis = nlAttr.getValueAsLong();
+            // If the RTA_EXPIRES attribute is malformed, return null.
+            if (sinceLastUseCentis == null) return null;
+            // RTA_EXPIRES returns time in clock ticks of USER_HZ(100), which is centiseconds
+            routeMsg.mSinceLastUseMillis = sinceLastUseCentis * 10;
+        }
+
         return routeMsg;
     }
 
     /**
      * Write a rtnetlink address message to {@link ByteBuffer}.
      */
-    @VisibleForTesting
-    protected void pack(ByteBuffer byteBuffer) {
+    public void pack(ByteBuffer byteBuffer) {
         getHeader().pack(byteBuffer);
         mRtmsg.pack(byteBuffer);
 
-        final StructNlAttr destination = new StructNlAttr(RTA_DST, mDestination.getAddress());
-        destination.pack(byteBuffer);
+        if (mSource != null) {
+            final StructNlAttr source = new StructNlAttr(RTA_SRC, mSource.getAddress());
+            source.pack(byteBuffer);
+        }
+
+        if (mDestination != null) {
+            final StructNlAttr destination = new StructNlAttr(RTA_DST, mDestination.getAddress());
+            destination.pack(byteBuffer);
+        }
 
         if (mGateway != null) {
             final StructNlAttr gateway = new StructNlAttr(RTA_GATEWAY, mGateway.getAddress());
             gateway.pack(byteBuffer);
         }
-        if (mIfindex != 0) {
-            final StructNlAttr ifindex = new StructNlAttr(RTA_OIF, mIfindex);
-            ifindex.pack(byteBuffer);
+        if (mIifIndex != 0) {
+            final StructNlAttr iifindex = new StructNlAttr(RTA_IIF, mIifIndex);
+            iifindex.pack(byteBuffer);
+        }
+        if (mOifIndex != 0) {
+            final StructNlAttr oifindex = new StructNlAttr(RTA_OIF, mOifIndex);
+            oifindex.pack(byteBuffer);
         }
         if (mRtaCacheInfo != null) {
             final StructNlAttr cacheInfo = new StructNlAttr(RTA_CACHEINFO,
                     mRtaCacheInfo.writeToBytes());
             cacheInfo.pack(byteBuffer);
         }
+        if (mSinceLastUseMillis >= 0) {
+            final long sinceLastUseCentis = mSinceLastUseMillis / 10;
+            final StructNlAttr expires = new StructNlAttr(RTA_EXPIRES, sinceLastUseCentis);
+            expires.pack(byteBuffer);
+        }
     }
 
     @Override
@@ -208,10 +316,14 @@
         return "RtNetlinkRouteMessage{ "
                 + "nlmsghdr{" + mHeader.toString(OsConstants.NETLINK_ROUTE) + "}, "
                 + "Rtmsg{" + mRtmsg.toString() + "}, "
-                + "destination{" + mDestination.getAddress().getHostAddress() + "}, "
+                + (mSource == null ? "" : "source{" + mSource.getAddress().getHostAddress() + "}, ")
+                + (mDestination == null ?
+                        "" : "destination{" + mDestination.getAddress().getHostAddress() + "}, ")
                 + "gateway{" + (mGateway == null ? "" : mGateway.getHostAddress()) + "}, "
-                + "ifindex{" + mIfindex + "}, "
+                + (mIifIndex == 0 ? "" : "iifindex{" + mIifIndex + "}, ")
+                + "oifindex{" + mOifIndex + "}, "
                 + "rta_cacheinfo{" + (mRtaCacheInfo == null ? "" : mRtaCacheInfo.toString()) + "} "
+                + (mSinceLastUseMillis < 0 ? "" : "sinceLastUseMillis{" + mSinceLastUseMillis + "}")
                 + "}";
     }
 }
diff --git a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/RtNetlinkRouteMessageTest.java b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/RtNetlinkRouteMessageTest.java
index 9881653..ca407d3 100644
--- a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/RtNetlinkRouteMessageTest.java
+++ b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/RtNetlinkRouteMessageTest.java
@@ -38,6 +38,7 @@
 import java.net.Inet6Address;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
+import java.util.Arrays;
 
 @RunWith(AndroidJUnit4.class)
 @SmallTest
@@ -127,6 +128,72 @@
         assertEquals(RTM_NEWROUTE_PACK_HEX, HexDump.toHexString(packBuffer.array()));
     }
 
+    private static final String RTM_GETROUTE_MULTICAST_IPV6_HEX =
+            "1C0000001A0001030000000000000000"             // struct nlmsghr
+            + "810000000000000000000000";                  // struct rtmsg
+
+    private static final String RTM_NEWROUTE_MULTICAST_IPV6_HEX =
+            "88000000180002000000000000000000"             // struct nlmsghr
+            + "81808000FE11000500000000"                   // struct rtmsg
+            + "08000F00FE000000"                           // RTA_TABLE
+            + "14000200FDACC0F1DBDB000195B7C1A464F944EA"   // RTA_SRC
+            + "14000100FF040000000000000000000000001234"   // RTA_DST
+            + "0800030014000000"                           // RTA_IIF
+            + "0C0009000800000111000000"                   // RTA_MULTIPATH
+            + "1C00110001000000000000009400000000000000"   // RTA_STATS
+            + "0000000000000000"
+            + "0C0017007617000000000000";                  // RTA_EXPIRES
+
+    @Test
+    public void testParseRtmNewRoute_MulticastIpv6() {
+        final ByteBuffer byteBuffer = toByteBuffer(RTM_NEWROUTE_MULTICAST_IPV6_HEX);
+        byteBuffer.order(ByteOrder.LITTLE_ENDIAN);  // For testing.
+
+        final NetlinkMessage msg = NetlinkMessage.parse(byteBuffer, NETLINK_ROUTE);
+        assertNotNull(msg);
+        assertTrue(msg instanceof RtNetlinkRouteMessage);
+        final RtNetlinkRouteMessage routeMsg = (RtNetlinkRouteMessage) msg;
+        final StructNlMsgHdr hdr = routeMsg.getHeader();
+        assertNotNull(hdr);
+        assertEquals(136, hdr.nlmsg_len);
+        assertEquals(NetlinkConstants.RTM_NEWROUTE, hdr.nlmsg_type);
+
+        final StructRtMsg rtmsg = routeMsg.getRtMsgHeader();
+        assertNotNull(rtmsg);
+        assertEquals((byte) 129, (byte) rtmsg.family);
+        assertEquals(128, rtmsg.dstLen);
+        assertEquals(128, rtmsg.srcLen);
+        assertEquals(0xFE, rtmsg.table);
+
+        assertEquals(routeMsg.getSource(),
+                new IpPrefix("fdac:c0f1:dbdb:1:95b7:c1a4:64f9:44ea/128"));
+        assertEquals(routeMsg.getDestination(), new IpPrefix("ff04::1234/128"));
+        assertEquals(20, routeMsg.getIifIndex());
+        assertEquals(60060, routeMsg.getSinceLastUseMillis());
+    }
+
+    // NEWROUTE message for multicast IPv6 with the packed attributes
+    private static final String RTM_NEWROUTE_MULTICAST_IPV6_PACK_HEX =
+            "58000000180002000000000000000000"             // struct nlmsghr
+            + "81808000FE11000500000000"                   // struct rtmsg
+            + "14000200FDACC0F1DBDB000195B7C1A464F944EA"   // RTA_SRC
+            + "14000100FF040000000000000000000000001234"   // RTA_DST
+            + "0800030014000000"                           // RTA_IIF
+            + "0C0017007617000000000000";                  // RTA_EXPIRES
+    @Test
+    public void testPackRtmNewRoute_MulticastIpv6() {
+        final ByteBuffer byteBuffer = toByteBuffer(RTM_NEWROUTE_MULTICAST_IPV6_PACK_HEX);
+        byteBuffer.order(ByteOrder.LITTLE_ENDIAN);  // For testing.
+        final NetlinkMessage msg = NetlinkMessage.parse(byteBuffer, NETLINK_ROUTE);
+        final RtNetlinkRouteMessage routeMsg = (RtNetlinkRouteMessage) msg;
+
+        final ByteBuffer packBuffer = ByteBuffer.allocate(88);
+        packBuffer.order(ByteOrder.LITTLE_ENDIAN);  // For testing.
+        routeMsg.pack(packBuffer);
+        assertEquals(RTM_NEWROUTE_MULTICAST_IPV6_PACK_HEX,
+                HexDump.toHexString(packBuffer.array()));
+    }
+
     private static final String RTM_NEWROUTE_TRUNCATED_HEX =
             "48000000180000060000000000000000"             // struct nlmsghr
             + "0A400000FC02000100000000"                   // struct rtmsg
@@ -220,10 +287,59 @@
                 + "scope: 0, type: 1, flags: 0}, "
                 + "destination{2001:db8:1::}, "
                 + "gateway{fe80::1}, "
-                + "ifindex{735}, "
+                + "oifindex{735}, "
                 + "rta_cacheinfo{clntref: 0, lastuse: 0, expires: 59998, error: 0, used: 0, "
                 + "id: 0, ts: 0, tsage: 0} "
                 + "}";
         assertEquals(expected, routeMsg.toString());
     }
+
+    @Test
+    public void testToString_RtmGetRoute() {
+        final ByteBuffer byteBuffer = toByteBuffer(RTM_GETROUTE_MULTICAST_IPV6_HEX);
+        byteBuffer.order(ByteOrder.LITTLE_ENDIAN);  // For testing.
+        final NetlinkMessage msg = NetlinkMessage.parse(byteBuffer, NETLINK_ROUTE);
+        assertNotNull(msg);
+        assertTrue(msg instanceof RtNetlinkRouteMessage);
+        final RtNetlinkRouteMessage routeMsg = (RtNetlinkRouteMessage) msg;
+        final String expected = "RtNetlinkRouteMessage{ "
+                + "nlmsghdr{"
+                + "StructNlMsgHdr{ nlmsg_len{28}, nlmsg_type{26(RTM_GETROUTE)}, "
+                + "nlmsg_flags{769(NLM_F_REQUEST|NLM_F_DUMP)}, nlmsg_seq{0}, nlmsg_pid{0} }}, "
+                + "Rtmsg{"
+                + "family: 129, dstLen: 0, srcLen: 0, tos: 0, table: 0, protocol: 0, "
+                + "scope: 0, type: 0, flags: 0}, "
+                + "destination{::}, "
+                + "gateway{}, "
+                + "oifindex{0}, "
+                + "rta_cacheinfo{} "
+                + "}";
+        assertEquals(expected, routeMsg.toString());
+    }
+
+    @Test
+    public void testToString_RtmNewRouteMulticastIpv6() {
+        final ByteBuffer byteBuffer = toByteBuffer(RTM_NEWROUTE_MULTICAST_IPV6_HEX);
+        byteBuffer.order(ByteOrder.LITTLE_ENDIAN);  // For testing.
+        final NetlinkMessage msg = NetlinkMessage.parse(byteBuffer, NETLINK_ROUTE);
+        assertNotNull(msg);
+        assertTrue(msg instanceof RtNetlinkRouteMessage);
+        final RtNetlinkRouteMessage routeMsg = (RtNetlinkRouteMessage) msg;
+        final String expected = "RtNetlinkRouteMessage{ "
+                + "nlmsghdr{"
+                + "StructNlMsgHdr{ nlmsg_len{136}, nlmsg_type{24(RTM_NEWROUTE)}, "
+                + "nlmsg_flags{2(NLM_F_MULTI)}, nlmsg_seq{0}, nlmsg_pid{0} }}, "
+                + "Rtmsg{"
+                + "family: 129, dstLen: 128, srcLen: 128, tos: 0, table: 254, protocol: 17, "
+                + "scope: 0, type: 5, flags: 0}, "
+                + "source{fdac:c0f1:dbdb:1:95b7:c1a4:64f9:44ea}, "
+                + "destination{ff04::1234}, "
+                + "gateway{}, "
+                + "iifindex{20}, "
+                + "oifindex{0}, "
+                + "rta_cacheinfo{} "
+                + "sinceLastUseMillis{60060}"
+                + "}";
+        assertEquals(expected, routeMsg.toString());
+    }
 }