Merge "DnsPinger changes incl. binding" (c9d39460) · Commits · e / os / android_frameworks_base

services/java/com/android/server/DnsPinger.java

+44 −34

Original line number	Diff line number	Diff line
		@@ -16,7 +16,6 @@

		package com.android.server;

		import android.content.ContentResolver;
		import android.content.Context;
		import android.net.ConnectivityManager;
		import android.net.LinkProperties;
		@@ -28,6 +27,7 @@ import android.util.Slog;
		import java.net.DatagramPacket;
		import java.net.DatagramSocket;
		import java.net.InetAddress;
		import java.net.NetworkInterface;
		import java.net.SocketTimeoutException;
		import java.util.Collection;
		import java.util.Random;
		@@ -49,7 +49,7 @@ public final class DnsPinger {
		private static final boolean V = true;

		/** Number of bytes for the query */
		private static final int DNS_QUERY_BASE_SIZE = 33;
		private static final int DNS_QUERY_BASE_SIZE = 32;

		/** The DNS port */
		private static final int DNS_PORT = 53;
		@@ -84,12 +84,7 @@ public final class DnsPinger {
		* dns set. Should not be null.
		*/
		public InetAddress getDns() {
		if (mConnectivityManager == null) {
		mConnectivityManager = (ConnectivityManager) mContext.getSystemService(
		Context.CONNECTIVITY_SERVICE);
		}

		LinkProperties curLinkProps = mConnectivityManager.getLinkProperties(mConnectionType);
		LinkProperties curLinkProps = getCurrentLinkProperties();
		if (curLinkProps == null) {
		Slog.e(TAG, "getCurLinkProperties:: LP for type" + mConnectionType + " is null!");
		return mDefaultDns;
		@@ -104,6 +99,15 @@ public final class DnsPinger {
		return dnses.iterator().next();
		}

		private LinkProperties getCurrentLinkProperties() {
		if (mConnectivityManager == null) {
		mConnectivityManager = (ConnectivityManager) mContext.getSystemService(
		Context.CONNECTIVITY_SERVICE);
		}

		return mConnectivityManager.getLinkProperties(mConnectionType);
		}

		private InetAddress getDefaultDns() {
		String dns = Settings.Secure.getString(mContext.getContentResolver(),
		Settings.Secure.DEFAULT_DNS_SERVER);
		@@ -130,8 +134,15 @@ public final class DnsPinger {
		// Set some socket properties
		socket.setSoTimeout(timeout);

		byte[] buf = new byte[DNS_QUERY_BASE_SIZE];
		fillQuery(buf);
		// Try to bind but continue ping if bind fails
		try {
		socket.setNetworkInterface(NetworkInterface.getByName(
		getCurrentLinkProperties().getInterfaceName()));
		} catch (Exception e) {
		Slog.d(TAG,"pingDns::Error binding to socket", e);
		}

		byte[] buf = constructQuery();

		// Send the DNS query

		@@ -164,48 +175,47 @@ public final class DnsPinger {

		}

		private static void fillQuery(byte[] buf) {

		/*
		* See RFC2929 (though the bit tables in there are misleading for us.
		* For example, the recursion desired bit is the 0th bit for us, but
		* looking there it would appear as the 7th bit of the byte
		/**
		* @return google.com DNS query packet
		*/

		// Make sure it's all zeroed out
		for (int i = 0; i < buf.length; i++)
		buf[i] = 0;

		// Form a query for www.android.com
		private static byte[] constructQuery() {
		byte[] buf = new byte[DNS_QUERY_BASE_SIZE];

		// [0-1] bytes are an ID, generate random ID for this query
		buf[0] = (byte) sRandom.nextInt(256);
		buf[1] = (byte) sRandom.nextInt(256);

		// [2-3] bytes are for flags.
		buf[2] = 1; // Recursion desired
		buf[2] = 0x01; // Recursion desired

		// [4-5] bytes are for the query count
		buf[5] = 1; // One query
		// [4-5] bytes are for number of queries (QCOUNT)
		buf[5] = 0x01;

		// [6-7] [8-9] [10-11] are all counts of other fields we don't use

		// [12-15] for www
		writeString(buf, 12, "www");

		// [16-23] for android
		writeString(buf, 16, "android");
		// [16-22] for google
		writeString(buf, 16, "google");

		// [23-26] for com
		writeString(buf, 23, "com");

		// [24-27] for com
		writeString(buf, 24, "com");
		// [27] is a null byte terminator byte for the url

		// [29-30] bytes are for QTYPE, set to 1
		buf[30] = 1;
		// [28-29] bytes are for QTYPE, set to 1 = A (host address)
		buf[29] = 0x01;

		// [31-32] bytes are for QCLASS, set to 1
		buf[32] = 1;
		// [30-31] bytes are for QCLASS, set to 1 = IN (internet)
		buf[31] = 0x01;

		return buf;
		}

		/**
		* Writes the string's length and its contents to the buffer
		*/
		private static void writeString(byte[] buf, int startPos, String string) {
		int pos = startPos;