WIP: implement dhcp in tunnel

1 files changed, 86 insertions, 18 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 edf6ac9e..f077189a 100644
--- a/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java
+++ b/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java
@@ -18,6 +18,7 @@ import com.wireguard.android.util.SharedLibraryLoader;
 import com.wireguard.config.Config;
 import com.wireguard.config.InetEndpoint;
 import com.wireguard.config.InetNetwork;
+import com.wireguard.config.ParseException;
 import com.wireguard.config.Peer;
 import com.wireguard.crypto.Key;
 import com.wireguard.crypto.KeyFormatException;
@@ -25,6 +26,7 @@ import com.wireguard.util.NonNullForAll;
 
 import java.net.InetAddress;
 import java.util.Collections;
+import java.util.LinkedHashSet;
 import java.util.Set;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.FutureTask;
@@ -76,10 +78,14 @@ public final class GoBackend implements Backend, EventHandler {
 
     private static native int wgGetSocketV6(int handle);
 
+    private static native void wgSetFd(int handle, int tunFd);
+
     private static native void wgTurnOff(int handle);
 
     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 String wgVersion();
 
     /**
@@ -205,14 +211,9 @@ public final class GoBackend implements Backend, EventHandler {
         return getState(tunnel);
     }
 
-    private void setStateInternal(final Tunnel tunnel, @Nullable final Config config, final State state)
+    private void setStateInternalFinalize(final Tunnel tunnel, final Config config, Set<InetNetwork> addresses)
             throws Exception {
-        Log.i(TAG, "Bringing tunnel " + tunnel.getName() + ' ' + state);
-
-        if (state == State.UP) {
-            if (config == null)
-                throw new BackendException(Reason.TUNNEL_MISSING_CONFIG);
-
+        if (true) { // Add scope to avoid changing indentation level
             if (VpnService.prepare(context) != null)
                 throw new BackendException(Reason.VPN_NOT_AUTHORIZED);
 
@@ -231,12 +232,6 @@ public final class GoBackend implements Backend, EventHandler {
             }
             service.setOwner(this);
 
-            if (currentTunnelHandle != -1) {
-                Log.w(TAG, "Tunnel already up");
-                return;
-            }
-
-
             dnsRetry: for (int i = 0; i < DNS_RESOLUTION_RETRIES; ++i) {
                 // Pre-resolve IPs so they're cached when building the userspace string
                 for (final Peer peer : config.getPeers()) {
@@ -268,9 +263,13 @@ public final class GoBackend implements Backend, EventHandler {
             for (final String includedApplication : config.getInterface().getIncludedApplications())
                 builder.addAllowedApplication(includedApplication);
 
-            for (final InetNetwork addr : config.getInterface().getAddresses())
-                builder.addAddress(addr.getAddress(), addr.getMask());
-
+            if (addresses.size() > 0) {
+                for (final InetNetwork addr : addresses)
+                    builder.addAddress(addr.getAddress(), addr.getMask());
+            } else {
+                for (final InetNetwork addr : config.getInterface().getAddresses())
+                    builder.addAddress(addr.getAddress(), addr.getMask());
+            }
             for (final InetAddress addr : config.getInterface().getDnsServers())
                 builder.addDnsServer(addr.getHostAddress());
 
@@ -304,7 +303,11 @@ public final class GoBackend implements Backend, EventHandler {
                 if (tun == null)
                     throw new BackendException(Reason.TUN_CREATION_ERROR);
                 Log.d(TAG, "Go backend " + wgVersion());
-                currentTunnelHandle = wgTurnOn(tunnel.getName(), tun.detachFd(), goConfig, this);
+                if (currentTunnelHandle < 0) {
+                    currentTunnelHandle = wgTurnOn(tunnel.getName(), tun.detachFd(), goConfig, this);
+                } else {
+                    wgSetFd(currentTunnelHandle, tun.detachFd());
+                }
             }
             if (currentTunnelHandle < 0)
                 throw new BackendException(Reason.GO_ACTIVATION_ERROR_CODE, currentTunnelHandle);
@@ -314,6 +317,35 @@ public final class GoBackend implements Backend, EventHandler {
 
             service.protect(wgGetSocketV4(currentTunnelHandle));
             service.protect(wgGetSocketV6(currentTunnelHandle));
+        }
+    }
+
+    private void setStateInternal(final Tunnel tunnel, @Nullable final Config config, final State state)
+            throws Exception {
+        Log.i(TAG, "Bringing tunnel " + tunnel.getName() + ' ' + state);
+
+        if (state == State.UP) {
+            if (config == null)
+                throw new BackendException(Reason.TUNNEL_MISSING_CONFIG);
+
+            if (currentTunnelHandle != -1) {
+                Log.w(TAG, "Tunnel already up");
+                return;
+            }
+
+            if (false) {
+                setStateInternalFinalize(tunnel, config, null);
+            } else {
+                // Build config
+                final String goConfig = config.toWgUserspaceString();
+
+                currentTunnelHandle = wgTurnOnDhcp(tunnel.getName(), goConfig, this);
+                if (currentTunnelHandle < 0)
+                    throw new BackendException(Reason.GO_ACTIVATION_ERROR_CODE, currentTunnelHandle);
+
+                currentTunnel = tunnel;
+                currentConfig = config;
+            }
         } else {
             if (currentTunnelHandle == -1) {
                 Log.w(TAG, "Tunnel already down");
@@ -330,7 +362,43 @@ public final class GoBackend implements Backend, EventHandler {
     }
 
     public void onEvent(String event) {
-	Log.d(TAG, "onEvent: " + event);
+        boolean isEvent = false;
+        Set<InetNetwork> addresses = new LinkedHashSet<>();
+
+        Log.d(TAG, "onEvent: " + event);
+        for (final String line : event.split("\\n")) {
+            final String[] params = line.split("=", 2);
+            if (params.length != 2)
+                break;
+
+            final String key = params[0];
+            final String value = params[1];
+
+            if ("event".equals(key)) {
+                isEvent = true;
+            } else if (!isEvent) {
+                break;
+            }
+
+            if ("address".equals(key)) {
+                for (final String strAddr : value.split(",")) {
+                    try {
+                        InetNetwork addr = InetNetwork.parse(strAddr);
+                        if (addr.getMask() < 33 || addr.getMask() == 128)
+                            addresses.add(addr);
+                    } catch(final ParseException ignored) {
+                    }
+                }
+            }
+        }
+
+        if (addresses.size() > 0) {
+            try {
+                setStateInternalFinalize(currentTunnel, currentConfig, addresses);
+            } catch (final Exception e) {
+                Log.d(TAG, "setStateInternalFinalize", e);
+            }
+        }
     }
 
     /**