1 files changed, 53 insertions, 5 deletions

diff --git a/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java b/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java
index fdbf0e9c..57071f63 100644
--- a/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java
+++ b/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java
@@ -25,8 +25,12 @@ import com.wireguard.crypto.KeyFormatException;
 import com.wireguard.util.NonNullForAll;
 
 import java.net.InetAddress;
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.UnknownHostException;
 import java.util.Collections;
 import java.util.LinkedHashSet;
+import java.util.Random;
 import java.util.Set;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.FutureTask;
@@ -50,6 +54,7 @@ public final class GoBackend implements Backend, EventHandler {
     private final Context context;
     @Nullable private Config currentConfig;
     @Nullable private Tunnel currentTunnel;
+    @Nullable private String currentDhcpEvent;
     private int currentTunnelHandle = -1;
 
     /**
@@ -84,7 +89,7 @@ public final class GoBackend implements Backend, EventHandler {
 
     private static native int wgTurnOn(String ifName, int tunFd, String settings, EventHandler handler);
 
-    private static native int wgTurnOnDhcp(String ifName, String settings, EventHandler handler);
+    private static native int wgTurnOnDhcp(String ifName, String lladdr, String settings, EventHandler handler);
 
     private static native String wgVersion();
 
@@ -94,8 +99,8 @@ public final class GoBackend implements Backend, EventHandler {
         if (tunnel != currentTunnel) {
             return info;
         }
-	// TODO update info
-	info.set("FIXME");
+	// TODO use nicer format
+	info.set(currentDhcpEvent);
 	return info;
     }
 
@@ -349,13 +354,18 @@ public final class GoBackend implements Backend, EventHandler {
             } else {
                 // Build config
                 final String goConfig = config.toWgUserspaceString();
+		// TODO verify that an address is available
+		final String llAddr = config.getInterface().getAddresses().iterator().next().getAddress().getHostAddress();
 
-                currentTunnelHandle = wgTurnOnDhcp(tunnel.getName(), goConfig, this);
+		Log.w(TAG, "Using DHCPv6 src=" + llAddr);
+
+                currentTunnelHandle = wgTurnOnDhcp(tunnel.getName(), llAddr, goConfig, this);
                 if (currentTunnelHandle < 0)
                     throw new BackendException(Reason.GO_ACTIVATION_ERROR_CODE, currentTunnelHandle);
 
                 currentTunnel = tunnel;
                 currentConfig = config;
+		currentDhcpEvent = null;
             }
         } else {
             if (currentTunnelHandle == -1) {
@@ -366,12 +376,22 @@ public final class GoBackend implements Backend, EventHandler {
             currentTunnel = null;
             currentTunnelHandle = -1;
             currentConfig = null;
+	    currentDhcpEvent = null;
             wgTurnOff(handleToClose);
         }
 
         tunnel.onStateChange(state);
     }
 
+    private byte[] generateIID() {
+	// The resulting IID MUST be compared against the reserved IPv6 IIDs
+	// [RFC5453] [IANA-RESERVED-IID] and against those IIDs already
+	Random rnd = new Random();
+	byte[] data = new byte[8];
+	rnd.nextBytes(data);
+	return data;
+    }
+    
     public void onEvent(String event) {
         boolean isEvent = false;
         Set<InetNetwork> addresses = new LinkedHashSet<>();
@@ -392,17 +412,45 @@ public final class GoBackend implements Backend, EventHandler {
             }
 
             if ("address".equals(key)) {
+		boolean hasPD = false;
+		byte[] iid = null;
+
                 for (final String strAddr : value.split(",")) {
                     try {
                         InetNetwork addr = InetNetwork.parse(strAddr);
-                        if (addr.getMask() < 33 || addr.getMask() == 128)
+                        if (addr.getAddress() instanceof Inet4Address)
+			    // Add IPv4 address
                             addresses.add(addr);
+			else if (addr.getMask() <= 64) {
+			    // IPv6 prefix delegation
+			    if (!hasPD) {
+				iid = generateIID();
+			    }
+			    hasPD = true;
+			    byte[] raw = addr.getAddress().getAddress();
+			    System.arraycopy(iid, 0, raw, 8, 8);
+			    InetAddress tempAddr = Inet6Address.getByAddress(null, raw, 0);
+			    addresses.add(InetNetwork.parse(tempAddr.getHostAddress() + '/' + addr.getMask()));
+			}
+                    } catch(final UnknownHostException ignored) {
                     } catch(final ParseException ignored) {
                     }
                 }
+
+		// TODO add ipv6 addresses from DHCPv6-NA if no PD.
             }
         }
 
+	if (isEvent) {
+	    StringBuilder buf = new StringBuilder();
+	    buf.append("addresses:\n");
+	    for (final InetNetwork addr : addresses) {
+		buf.append(addr.toString());
+		buf.append('\n');
+	    }
+	    currentDhcpEvent = buf.toString();
+	}
+
         if (addresses.size() > 0) {
             try {
                 setStateInternalFinalize(currentTunnel, currentConfig, addresses);