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-rw-r--r--core/java/android/net/KeepalivePacketData.aidl19
-rw-r--r--core/java/android/net/KeepalivePacketData.java174
-rw-r--r--core/java/android/net/util/IpUtils.java151
3 files changed, 344 insertions, 0 deletions
diff --git a/core/java/android/net/KeepalivePacketData.aidl b/core/java/android/net/KeepalivePacketData.aidl
new file mode 100644
index 000000000000..d456b53fd188
--- /dev/null
+++ b/core/java/android/net/KeepalivePacketData.aidl
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2018 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;
+
+parcelable KeepalivePacketData;
diff --git a/core/java/android/net/KeepalivePacketData.java b/core/java/android/net/KeepalivePacketData.java
new file mode 100644
index 000000000000..08d4ff5da966
--- /dev/null
+++ b/core/java/android/net/KeepalivePacketData.java
@@ -0,0 +1,174 @@
+/*
+ * Copyright (C) 2015 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 android.system.OsConstants;
+import android.net.ConnectivityManager;
+import android.net.util.IpUtils;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.system.OsConstants;
+import android.util.Log;
+
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.InetAddress;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
+import static android.net.ConnectivityManager.PacketKeepalive.*;
+
+/**
+ * Represents the actual packets that are sent by the
+ * {@link android.net.ConnectivityManager.PacketKeepalive} API.
+ *
+ * @hide
+ */
+public class KeepalivePacketData implements Parcelable {
+ private static final String TAG = "KeepalivePacketData";
+
+ /** Source IP address */
+ public final InetAddress srcAddress;
+
+ /** Destination IP address */
+ public final InetAddress dstAddress;
+
+ /** Source port */
+ public final int srcPort;
+
+ /** Destination port */
+ public final int dstPort;
+
+ /** Packet data. A raw byte string of packet data, not including the link-layer header. */
+ private final byte[] mPacket;
+
+ private static final int IPV4_HEADER_LENGTH = 20;
+ private static final int UDP_HEADER_LENGTH = 8;
+
+ // This should only be constructed via static factory methods, such as
+ // nattKeepalivePacket
+ protected KeepalivePacketData(InetAddress srcAddress, int srcPort,
+ InetAddress dstAddress, int dstPort, byte[] data) throws InvalidPacketException {
+ this.srcAddress = srcAddress;
+ this.dstAddress = dstAddress;
+ this.srcPort = srcPort;
+ this.dstPort = dstPort;
+ this.mPacket = data;
+
+ // Check we have two IP addresses of the same family.
+ if (srcAddress == null || dstAddress == null || !srcAddress.getClass().getName()
+ .equals(dstAddress.getClass().getName())) {
+ Log.e(TAG, "Invalid or mismatched InetAddresses in KeepalivePacketData");
+ throw new InvalidPacketException(ERROR_INVALID_IP_ADDRESS);
+ }
+
+ // Check the ports.
+ if (!IpUtils.isValidUdpOrTcpPort(srcPort) || !IpUtils.isValidUdpOrTcpPort(dstPort)) {
+ Log.e(TAG, "Invalid ports in KeepalivePacketData");
+ throw new InvalidPacketException(ERROR_INVALID_PORT);
+ }
+ }
+
+ public static class InvalidPacketException extends Exception {
+ public final int error;
+ public InvalidPacketException(int error) {
+ this.error = error;
+ }
+ }
+
+ public byte[] getPacket() {
+ return mPacket.clone();
+ }
+
+ public static KeepalivePacketData nattKeepalivePacket(
+ InetAddress srcAddress, int srcPort, InetAddress dstAddress, int dstPort)
+ throws InvalidPacketException {
+
+ // FIXME: remove this and actually support IPv6 keepalives
+ if (srcAddress instanceof Inet6Address && dstAddress instanceof Inet6Address) {
+ // Optimistically returning an IPv6 Keepalive Packet with no data,
+ // which currently only works on cellular
+ return new KeepalivePacketData(srcAddress, srcPort, dstAddress, dstPort, new byte[0]);
+ }
+
+ if (!(srcAddress instanceof Inet4Address) || !(dstAddress instanceof Inet4Address)) {
+ throw new InvalidPacketException(ERROR_INVALID_IP_ADDRESS);
+ }
+
+ if (dstPort != 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 KeepalivePacketData(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);
+ out.writeByteArray(mPacket);
+ }
+
+ private KeepalivePacketData(Parcel in) {
+ srcAddress = NetworkUtils.numericToInetAddress(in.readString());
+ dstAddress = NetworkUtils.numericToInetAddress(in.readString());
+ srcPort = in.readInt();
+ dstPort = in.readInt();
+ mPacket = in.createByteArray();
+ }
+
+ /** Parcelable Creator */
+ public static final Parcelable.Creator<KeepalivePacketData> CREATOR =
+ new Parcelable.Creator<KeepalivePacketData>() {
+ public KeepalivePacketData createFromParcel(Parcel in) {
+ return new KeepalivePacketData(in);
+ }
+
+ public KeepalivePacketData[] newArray(int size) {
+ return new KeepalivePacketData[size];
+ }
+ };
+
+}
diff --git a/core/java/android/net/util/IpUtils.java b/core/java/android/net/util/IpUtils.java
new file mode 100644
index 000000000000..e037c4035aca
--- /dev/null
+++ b/core/java/android/net/util/IpUtils.java
@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2015 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.util;
+
+import java.net.Inet6Address;
+import java.net.InetAddress;
+import java.nio.BufferOverflowException;
+import java.nio.BufferUnderflowException;
+import java.nio.ByteBuffer;
+import java.nio.ShortBuffer;
+
+import static android.system.OsConstants.IPPROTO_TCP;
+import static android.system.OsConstants.IPPROTO_UDP;
+
+/**
+ * @hide
+ */
+public class IpUtils {
+ /**
+ * Converts a signed short value to an unsigned int value. Needed
+ * because Java does not have unsigned types.
+ */
+ private static int intAbs(short v) {
+ return v & 0xFFFF;
+ }
+
+ /**
+ * Performs an IP checksum (used in IP header and across UDP
+ * payload) on the specified portion of a ByteBuffer. The seed
+ * allows the checksum to commence with a specified value.
+ */
+ private static int checksum(ByteBuffer buf, int seed, int start, int end) {
+ int sum = seed;
+ final int bufPosition = buf.position();
+
+ // set position of original ByteBuffer, so that the ShortBuffer
+ // will be correctly initialized
+ buf.position(start);
+ ShortBuffer shortBuf = buf.asShortBuffer();
+
+ // re-set ByteBuffer position
+ buf.position(bufPosition);
+
+ final int numShorts = (end - start) / 2;
+ for (int i = 0; i < numShorts; i++) {
+ sum += intAbs(shortBuf.get(i));
+ }
+ start += numShorts * 2;
+
+ // see if a singleton byte remains
+ if (end != start) {
+ short b = buf.get(start);
+
+ // make it unsigned
+ if (b < 0) {
+ b += 256;
+ }
+
+ sum += b * 256;
+ }
+
+ sum = ((sum >> 16) & 0xFFFF) + (sum & 0xFFFF);
+ sum = ((sum + ((sum >> 16) & 0xFFFF)) & 0xFFFF);
+ int negated = ~sum;
+ return intAbs((short) negated);
+ }
+
+ private static int pseudoChecksumIPv4(
+ ByteBuffer buf, int headerOffset, int protocol, int transportLen) {
+ int partial = protocol + transportLen;
+ partial += intAbs(buf.getShort(headerOffset + 12));
+ partial += intAbs(buf.getShort(headerOffset + 14));
+ partial += intAbs(buf.getShort(headerOffset + 16));
+ partial += intAbs(buf.getShort(headerOffset + 18));
+ return partial;
+ }
+
+ private static int pseudoChecksumIPv6(
+ ByteBuffer buf, int headerOffset, int protocol, int transportLen) {
+ int partial = protocol + transportLen;
+ for (int offset = 8; offset < 40; offset += 2) {
+ partial += intAbs(buf.getShort(headerOffset + offset));
+ }
+ return partial;
+ }
+
+ private static byte ipversion(ByteBuffer buf, int headerOffset) {
+ return (byte) ((buf.get(headerOffset) & (byte) 0xf0) >> 4);
+ }
+
+ public static short ipChecksum(ByteBuffer buf, int headerOffset) {
+ byte ihl = (byte) (buf.get(headerOffset) & 0x0f);
+ return (short) checksum(buf, 0, headerOffset, headerOffset + ihl * 4);
+ }
+
+ private static short transportChecksum(ByteBuffer buf, int protocol,
+ int ipOffset, int transportOffset, int transportLen) {
+ if (transportLen < 0) {
+ throw new IllegalArgumentException("Transport length < 0: " + transportLen);
+ }
+ int sum;
+ byte ver = ipversion(buf, ipOffset);
+ if (ver == 4) {
+ sum = pseudoChecksumIPv4(buf, ipOffset, protocol, transportLen);
+ } else if (ver == 6) {
+ sum = pseudoChecksumIPv6(buf, ipOffset, protocol, transportLen);
+ } else {
+ throw new UnsupportedOperationException("Checksum must be IPv4 or IPv6");
+ }
+
+ sum = checksum(buf, sum, transportOffset, transportOffset + transportLen);
+ if (protocol == IPPROTO_UDP && sum == 0) {
+ sum = (short) 0xffff;
+ }
+ return (short) sum;
+ }
+
+ public static short udpChecksum(ByteBuffer buf, int ipOffset, int transportOffset) {
+ int transportLen = intAbs(buf.getShort(transportOffset + 4));
+ return transportChecksum(buf, IPPROTO_UDP, ipOffset, transportOffset, transportLen);
+ }
+
+ public static short tcpChecksum(ByteBuffer buf, int ipOffset, int transportOffset,
+ int transportLen) {
+ return transportChecksum(buf, IPPROTO_TCP, ipOffset, transportOffset, transportLen);
+ }
+
+ public static String addressAndPortToString(InetAddress address, int port) {
+ return String.format(
+ (address instanceof Inet6Address) ? "[%s]:%d" : "%s:%d",
+ address.getHostAddress(), port);
+ }
+
+ public static boolean isValidUdpOrTcpPort(int port) {
+ return port > 0 && port < 65536;
+ }
+}
generated by cgit v1.2.3 (git 2.25.1) at 2026-01-06 20:02:03 +0000