Merge "Fix cannot create Nat-T keepalive on mobile data" into qt-dev

2 files changed, 118 insertions, 2 deletions

diff --git a/core/java/android/net/NattKeepalivePacketData.java b/core/java/android/net/NattKeepalivePacketData.java
new file mode 100644
index 000000000000..a77c244d6b40
--- /dev/null
+++ b/core/java/android/net/NattKeepalivePacketData.java
@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net;
+
+import static android.net.SocketKeepalive.ERROR_INVALID_IP_ADDRESS;
+import static android.net.SocketKeepalive.ERROR_INVALID_PORT;
+
+import android.net.SocketKeepalive.InvalidPacketException;
+import android.net.util.IpUtils;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.system.OsConstants;
+
+import java.net.Inet4Address;
+import java.net.InetAddress;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
+/** @hide */
+public final class NattKeepalivePacketData extends KeepalivePacketData implements Parcelable {
+    // This should only be constructed via static factory methods, such as
+    // nattKeepalivePacket
+    private NattKeepalivePacketData(InetAddress srcAddress, int srcPort,
+            InetAddress dstAddress, int dstPort, byte[] data) throws
+            InvalidPacketException {
+        super(srcAddress, srcPort, dstAddress, dstPort, data);
+    }
+
+    /**
+     * Factory method to create Nat-T keepalive packet structure.
+     */
+    public static NattKeepalivePacketData nattKeepalivePacket(
+            InetAddress srcAddress, int srcPort, InetAddress dstAddress, int dstPort)
+            throws InvalidPacketException {
+
+        if (!(srcAddress instanceof Inet4Address) || !(dstAddress instanceof Inet4Address)) {
+            throw new InvalidPacketException(ERROR_INVALID_IP_ADDRESS);
+        }
+
+        if (dstPort != NattSocketKeepalive.NATT_PORT) {
+            throw new InvalidPacketException(ERROR_INVALID_PORT);
+        }
+
+        int length = IPV4_HEADER_LENGTH + UDP_HEADER_LENGTH + 1;
+        ByteBuffer buf = ByteBuffer.allocate(length);
+        buf.order(ByteOrder.BIG_ENDIAN);
+        buf.putShort((short) 0x4500);             // IP version and TOS
+        buf.putShort((short) length);
+        buf.putInt(0);                            // ID, flags, offset
+        buf.put((byte) 64);                       // TTL
+        buf.put((byte) OsConstants.IPPROTO_UDP);
+        int ipChecksumOffset = buf.position();
+        buf.putShort((short) 0);                  // IP checksum
+        buf.put(srcAddress.getAddress());
+        buf.put(dstAddress.getAddress());
+        buf.putShort((short) srcPort);
+        buf.putShort((short) dstPort);
+        buf.putShort((short) (length - 20));      // UDP length
+        int udpChecksumOffset = buf.position();
+        buf.putShort((short) 0);                  // UDP checksum
+        buf.put((byte) 0xff);                     // NAT-T keepalive
+        buf.putShort(ipChecksumOffset, IpUtils.ipChecksum(buf, 0));
+        buf.putShort(udpChecksumOffset, IpUtils.udpChecksum(buf, 0, IPV4_HEADER_LENGTH));
+
+        return new NattKeepalivePacketData(srcAddress, srcPort, dstAddress, dstPort, buf.array());
+    }
+
+    /** Parcelable Implementation */
+    public int describeContents() {
+        return 0;
+    }
+
+    /** Write to parcel */
+    public void writeToParcel(Parcel out, int flags) {
+        out.writeString(srcAddress.getHostAddress());
+        out.writeString(dstAddress.getHostAddress());
+        out.writeInt(srcPort);
+        out.writeInt(dstPort);
+    }
+
+    /** Parcelable Creator */
+    public static final Parcelable.Creator<NattKeepalivePacketData> CREATOR =
+            new Parcelable.Creator<NattKeepalivePacketData>() {
+                public NattKeepalivePacketData createFromParcel(Parcel in) {
+                    final InetAddress srcAddress =
+                            InetAddresses.parseNumericAddress(in.readString());
+                    final InetAddress dstAddress =
+                            InetAddresses.parseNumericAddress(in.readString());
+                    final int srcPort = in.readInt();
+                    final int dstPort = in.readInt();
+                    try {
+                        return NattKeepalivePacketData.nattKeepalivePacket(srcAddress, srcPort,
+                                    dstAddress, dstPort);
+                    } catch (InvalidPacketException e) {
+                        throw new IllegalArgumentException(
+                                "Invalid NAT-T keepalive data: " + e.error);
+                    }
+                }
+
+                public NattKeepalivePacketData[] newArray(int size) {
+                    return new NattKeepalivePacketData[size];
+                }
+            };
+}
diff --git a/core/java/android/net/NetworkAgent.java b/core/java/android/net/NetworkAgent.java
index 419fa7a61de5..f416fc795990 100644
--- a/core/java/android/net/NetworkAgent.java
+++ b/core/java/android/net/NetworkAgent.java
@@ -511,7 +511,6 @@ public abstract class NetworkAgent extends Handler {
      * override this method.
      */
     protected void addKeepalivePacketFilter(Message msg) {
-        onSocketKeepaliveEvent(msg.arg1, SocketKeepalive.ERROR_UNSUPPORTED);
     }
 
     /**
@@ -520,7 +519,6 @@ public abstract class NetworkAgent extends Handler {
      * must override this method.
      */
     protected void removeKeepalivePacketFilter(Message msg) {
-        onSocketKeepaliveEvent(msg.arg1, SocketKeepalive.ERROR_UNSUPPORTED);
     }
 
     /**