Add StructUdpHeader class to parse UDP header from a packet
Test: atest NetworkStaticLibTests
Change-Id: I98571b8ed916b8e0da5940fe3d8d1f66b24ad93e
diff --git a/staticlibs/device/com/android/net/module/util/structs/UdpHeader.java b/staticlibs/device/com/android/net/module/util/structs/UdpHeader.java
new file mode 100644
index 0000000..8b0316b
--- /dev/null
+++ b/staticlibs/device/com/android/net/module/util/structs/UdpHeader.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2021 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 com.android.net.module.util.structs;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+/**
+ * L4 UDP header as per https://tools.ietf.org/html/rfc768.
+ *
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Source Port | Destination Port |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Length | Checksum |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | data octets ...
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ...
+ */
+public class UdpHeader extends Struct {
+ @Field(order = 0, type = Type.U16)
+ public final int srcPort;
+ @Field(order = 1, type = Type.U16)
+ public final int dstPort;
+ @Field(order = 2, type = Type.U16)
+ public final int length;
+ @Field(order = 3, type = Type.S16)
+ public final short checksum;
+
+ public UdpHeader(final int srcPort, final int dstPort, final int length,
+ final short checksum) {
+ this.srcPort = srcPort;
+ this.dstPort = dstPort;
+ this.length = length;
+ this.checksum = checksum;
+ }
+}