diff --git a/bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/LanTcpPlugin.java b/bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/LanTcpPlugin.java
index 7d26b8e5e06999e1b7b48561e1f039dd9e4a3991..37c5935f949f4199b5e977728ca4cb8492171a2e 100644
--- a/bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/LanTcpPlugin.java
+++ b/bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/LanTcpPlugin.java
@@ -23,7 +23,7 @@ import java.net.SocketAddress;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.Collections;
-import java.util.LinkedList;
+import java.util.Comparator;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.Executor;
@@ -44,6 +44,9 @@ class LanTcpPlugin extends TcpPlugin {
private static final Logger LOG =
Logger.getLogger(LanTcpPlugin.class.getName());
+ private static final LanAddressComparator ADDRESS_COMPARATOR =
+ new LanAddressComparator();
+
private static final int MAX_ADDRESSES = 4;
private static final String SEPARATOR = ",";
@@ -63,19 +66,18 @@ class LanTcpPlugin extends TcpPlugin {
TransportProperties p = callback.getLocalProperties();
String oldIpPorts = p.get(PROP_IP_PORTS);
List<InetSocketAddress> olds = parseSocketAddresses(oldIpPorts);
- List<InetSocketAddress> locals = new LinkedList<>();
+ List<InetSocketAddress> locals = new ArrayList<>();
for (InetAddress local : getLocalIpAddresses()) {
if (isAcceptableAddress(local)) {
// If this is the old address, try to use the same port
for (InetSocketAddress old : olds) {
- if (old.getAddress().equals(local)) {
- int port = old.getPort();
- locals.add(0, new InetSocketAddress(local, port));
- }
+ if (old.getAddress().equals(local))
+ locals.add(new InetSocketAddress(local, old.getPort()));
}
locals.add(new InetSocketAddress(local, 0));
}
}
+ Collections.sort(locals, ADDRESS_COMPARATOR);
return locals;
}
@@ -153,17 +155,39 @@ class LanTcpPlugin extends TcpPlugin {
// Package access for testing
boolean addressesAreOnSameLan(byte[] localIp, byte[] remoteIp) {
// 10.0.0.0/8
- if (localIp[0] == 10) return remoteIp[0] == 10;
+ if (isPrefix10(localIp)) return isPrefix10(remoteIp);
// 172.16.0.0/12
- if (localIp[0] == (byte) 172 && (localIp[1] & 0xF0) == 16)
- return remoteIp[0] == (byte) 172 && (remoteIp[1] & 0xF0) == 16;
+ if (isPrefix172(localIp)) return isPrefix172(remoteIp);
// 192.168.0.0/16
- if (localIp[0] == (byte) 192 && localIp[1] == (byte) 168)
- return remoteIp[0] == (byte) 192 && remoteIp[1] == (byte) 168;
+ if (isPrefix192(localIp)) return isPrefix192(remoteIp);
// Unrecognised prefix - may be compatible
return true;
}
+ private static boolean isPrefix10(byte[] ipv4) {
+ return ipv4[0] == 10;
+ }
+
+ private static boolean isPrefix172(byte[] ipv4) {
+ return ipv4[0] == (byte) 172 && (ipv4[1] & 0xF0) == 16;
+ }
+
+ private static boolean isPrefix192(byte[] ipv4) {
+ return ipv4[0] == (byte) 192 && ipv4[1] == (byte) 168;
+ }
+
+ // Returns the prefix length for an RFC 1918 address, or 0 for any other
+ // address
+ private static int getRfc1918PrefixLength(InetAddress addr) {
+ if (!(addr instanceof Inet4Address)) return 0;
+ if (!addr.isSiteLocalAddress()) return 0;
+ byte[] ipv4 = addr.getAddress();
+ if (isPrefix10(ipv4)) return 8;
+ if (isPrefix172(ipv4)) return 12;
+ if (isPrefix192(ipv4)) return 16;
+ return 0;
+ }
+
@Override
public boolean supportsKeyAgreement() {
return true;
@@ -278,4 +302,19 @@ class LanTcpPlugin extends TcpPlugin {
}
}
}
+
+ static class LanAddressComparator implements Comparator<InetSocketAddress> {
+
+ @Override
+ public int compare(InetSocketAddress a, InetSocketAddress b) {
+ // Prefer addresses with non-zero ports
+ int aPort = a.getPort(), bPort = b.getPort();
+ if (aPort > 0 && bPort == 0) return -1;
+ if (aPort == 0 && bPort > 0) return 1;
+ // Prefer addresses with longer RFC 1918 prefixes
+ int aPrefix = getRfc1918PrefixLength(a.getAddress());
+ int bPrefix = getRfc1918PrefixLength(b.getAddress());
+ return bPrefix - aPrefix;
+ }
+ }
}
diff --git a/bramble-core/src/test/java/org/briarproject/bramble/plugin/tcp/LanTcpPluginTest.java b/bramble-core/src/test/java/org/briarproject/bramble/plugin/tcp/LanTcpPluginTest.java
index d6ea0b6390289463e1049bc3fff8acc3f3f7c934..ede3df810f2c646728e9f23715e5d53723d5e7b5 100644
--- a/bramble-core/src/test/java/org/briarproject/bramble/plugin/tcp/LanTcpPluginTest.java
+++ b/bramble-core/src/test/java/org/briarproject/bramble/plugin/tcp/LanTcpPluginTest.java
@@ -11,6 +11,7 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
import org.briarproject.bramble.api.properties.TransportProperties;
import org.briarproject.bramble.api.settings.Settings;
+import org.briarproject.bramble.plugin.tcp.LanTcpPlugin.LanAddressComparator;
import org.briarproject.bramble.test.BrambleTestCase;
import org.junit.Test;
@@ -22,6 +23,7 @@ import java.net.NetworkInterface;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Collections;
+import java.util.Comparator;
import java.util.Hashtable;
import java.util.Map;
import java.util.concurrent.Callable;
@@ -56,6 +58,9 @@ public class LanTcpPluginTest extends BrambleTestCase {
// Local and remote in 192.168.0.0/16 should return true
assertTrue(plugin.addressesAreOnSameLan(makeAddress(192, 168, 0, 0),
makeAddress(192, 168, 255, 255)));
+ // Local and remote in 169.254.0.0/16 (link-local) should return true
+ assertTrue(plugin.addressesAreOnSameLan(makeAddress(169, 254, 0, 0),
+ makeAddress(169, 254, 255, 255)));
// Local and remote in different recognised prefixes should return false
assertFalse(plugin.addressesAreOnSameLan(makeAddress(10, 0, 0, 0),
makeAddress(172, 31, 255, 255)));
@@ -269,6 +274,57 @@ public class LanTcpPluginTest extends BrambleTestCase {
plugin.stop();
}
+ @Test
+ public void testComparatorPrefersNonZeroPorts() throws Exception {
+ Comparator<InetSocketAddress> comparator = new LanAddressComparator();
+ InetSocketAddress nonZero = new InetSocketAddress("1.2.3.4", 1234);
+ InetSocketAddress zero = new InetSocketAddress("1.2.3.4", 0);
+
+ assertEquals(0, comparator.compare(nonZero, nonZero));
+ assertTrue(comparator.compare(nonZero, zero) < 0);
+
+ assertTrue(comparator.compare(zero, nonZero) > 0);
+ assertEquals(0, comparator.compare(zero, zero));
+ }
+
+ @Test
+ public void testComparatorPrefersLongerPrefixes() throws Exception {
+ Comparator<InetSocketAddress> comparator = new LanAddressComparator();
+ InetSocketAddress prefix192 = new InetSocketAddress("192.168.0.1", 0);
+ InetSocketAddress prefix172 = new InetSocketAddress("172.16.0.1", 0);
+ InetSocketAddress prefix10 = new InetSocketAddress("10.0.0.1", 0);
+
+ assertEquals(0, comparator.compare(prefix192, prefix192));
+ assertTrue(comparator.compare(prefix192, prefix172) < 0);
+ assertTrue(comparator.compare(prefix192, prefix10) < 0);
+
+ assertTrue(comparator.compare(prefix172, prefix192) > 0);
+ assertEquals(0, comparator.compare(prefix172, prefix172));
+ assertTrue(comparator.compare(prefix172, prefix10) < 0);
+
+ assertTrue(comparator.compare(prefix10, prefix192) > 0);
+ assertTrue(comparator.compare(prefix10, prefix172) > 0);
+ assertEquals(0, comparator.compare(prefix10, prefix10));
+ }
+
+ @Test
+ public void testComparatorPrefersSiteLocalToLinkLocal() throws Exception {
+ Comparator<InetSocketAddress> comparator = new LanAddressComparator();
+ InetSocketAddress prefix192 = new InetSocketAddress("192.168.0.1", 0);
+ InetSocketAddress prefix172 = new InetSocketAddress("172.16.0.1", 0);
+ InetSocketAddress prefix10 = new InetSocketAddress("10.0.0.1", 0);
+ InetSocketAddress linkLocal = new InetSocketAddress("169.254.0.1", 0);
+
+ assertTrue(comparator.compare(prefix192, linkLocal) < 0);
+ assertTrue(comparator.compare(prefix172, linkLocal) < 0);
+ assertTrue(comparator.compare(prefix10, linkLocal) < 0);
+
+ assertTrue(comparator.compare(linkLocal, prefix192) > 0);
+ assertTrue(comparator.compare(linkLocal, prefix172) > 0);
+ assertTrue(comparator.compare(linkLocal, prefix10) > 0);
+ assertEquals(0, comparator.compare(linkLocal, linkLocal));
+ }
+
private boolean systemHasLocalIpv4Address() throws Exception {
for (NetworkInterface i : Collections.list(
NetworkInterface.getNetworkInterfaces())) {