WIP: implement dhcp in tunnel

4 files changed, 155 insertions, 29 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);
+            }
+        }
     }
 
     /**
diff --git a/tunnel/tools/libwg-go/api-android.go b/tunnel/tools/libwg-go/api-android.go
index 2fb6e40f..cadbab12 100644
--- a/tunnel/tools/libwg-go/api-android.go
+++ b/tunnel/tools/libwg-go/api-android.go
@@ -32,6 +32,7 @@ import (
 	"golang.zx2c4.com/wireguard/tun/netstack/ipvlan"
 
 	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/link/fdbased"
 	"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
 	"gvisor.dev/gvisor/pkg/tcpip/network/ipv6"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
@@ -63,12 +64,21 @@ type TunnelHandle struct {
 	eventHandler unsafe.Pointer
 	cancel context.CancelFunc
 	master *ipvlan.IPVLANMaster
+	//	tunEP *stack.LinkEndpoint
+	tunFd int
 }
 
+var globalStack *stack.Stack
 var tunnelHandles map[int32]TunnelHandle
 
 func init() {
 	tunnelHandles = make(map[int32]TunnelHandle)
+	opts := stack.Options{
+		NetworkProtocols:   []stack.NetworkProtocolFactory{ipv4.NewProtocol, ipv6.NewProtocol},
+		TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol, udp.NewProtocol},
+		HandleLocal:        true,
+	}
+	globalStack = stack.New(opts)
 	signals := make(chan os.Signal)
 	signal.Notify(signals, unix.SIGUSR2)
 	go func() {
@@ -200,12 +210,7 @@ func wgTurnOnDhcp(interfaceName string, settings string, eventHandler unsafe.Poi
 		Errorf:   AndroidLogger{level: C.ANDROID_LOG_ERROR, tag: tag}.Printf,
 	}
 
-	opts := stack.Options{
-		NetworkProtocols:   []stack.NetworkProtocolFactory{ipv4.NewProtocol, ipv6.NewProtocol},
-		TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol, udp.NewProtocol},
-		HandleLocal:        true,
-	}
-	stack := stack.New(opts)
+	stack := globalStack
 
 	// FIXME IP address
 	ipStr := "fe80::101"
@@ -308,14 +313,19 @@ func wgTurnOnDhcp(interfaceName string, settings string, eventHandler unsafe.Poi
 			return
 		}
 
+		msg := ""
+
 		logger.Verbosef("DHCP finished")
 		for _, addr := range addrs {
 			logger.Verbosef("Address: %v", addr)
+			if msg == "" {
+				msg = "event=1\naddress=" + addr.String()
+			} else {
+				msg += "," + addr.String()
+			}
 		}
 
-		// TODO move to wgSetTunFd
-		// tunEP := newTun(stack, 2, "tun0")
-		// master.SetIntEP(tunEP)
+		C.wgOnEvent(tunnelHandles[i].eventHandler, C.CString(msg))
 	}(ctx)
 
 	logger.Verbosef("Before wgOnEvent %v", eventHandler)
@@ -325,12 +335,35 @@ func wgTurnOnDhcp(interfaceName string, settings string, eventHandler unsafe.Poi
 	return i
 }
 
+//export wgSetFd
+func wgSetFd(tunnelHandle int32, tunFd int32) {
+	handle, ok := tunnelHandles[tunnelHandle]
+	if !ok {
+		return
+	}
+
+	// FIXME MTU
+	var mtu uint32 = 1280
+	tunEP, err := fdbased.New(&fdbased.Options{FDs: []int{int(tunFd)}, MTU: mtu})
+	if err != nil {
+		log.Fatal(err)
+	}
+	handle.tunFd = int(tunFd)
+	handle.master.SetIntEP(tunEP)
+}
+
 //export wgTurnOff
 func wgTurnOff(tunnelHandle int32) unsafe.Pointer {
 	handle, ok := tunnelHandles[tunnelHandle]
 	if !ok {
 		return nil
 	}
+	if handle.master != nil {
+		globalStack.RemoveNIC(1)
+		handle.master.SetIntEP(nil)
+		unix.Close(handle.tunFd)
+	}
+
 	eventHandler := handle.eventHandler
 	C.wgOnEvent(handle.eventHandler, C.CString("Called wgTurnOff"))
 	delete(tunnelHandles, tunnelHandle)
diff --git a/tunnel/tools/libwg-go/go.mod b/tunnel/tools/libwg-go/go.mod
index 6fdb520c..98bbf52a 100644
--- a/tunnel/tools/libwg-go/go.mod
+++ b/tunnel/tools/libwg-go/go.mod
@@ -13,4 +13,4 @@ require (
 	golang.zx2c4.com/wintun v0.0.0-20211104114900-415007cec224 // indirect
 )
 
-replace golang.zx2c4.com/wireguard/tun/netstack => golang.m7n.se/wireguard/tun/netstack v0.0.0-20210315004706-824f10afd504
+replace golang.zx2c4.com/wireguard/tun/netstack => golang.m7n.se/wireguard/tun/netstack v0.0.0-20210315192121-e7c9dcf39d3f
diff --git a/tunnel/tools/libwg-go/jni.c b/tunnel/tools/libwg-go/jni.c
index de6a1e85..3897b2b7 100644
--- a/tunnel/tools/libwg-go/jni.c
+++ b/tunnel/tools/libwg-go/jni.c
@@ -14,6 +14,7 @@
 struct go_string { const char *str; long n; };
 extern int wgTurnOn(struct go_string ifname, int tun_fd, struct go_string settings, void *eventHandler);
 extern int wgTurnOnDhcp(struct go_string ifname, struct go_string settings, void *eventHandler);
+extern void wgSetFd(int handle, int tun_fd);
 extern void *wgTurnOff(int handle);
 extern int wgGetSocketV4(int handle);
 extern int wgGetSocketV6(int handle);
@@ -59,10 +60,29 @@ JNIEXPORT jint JNICALL Java_com_wireguard_android_backend_GoBackend_wgTurnOn(JNI
 	const char *settings_str = (*env)->GetStringUTFChars(env, settings, 0);
 	size_t settings_len = (*env)->GetStringUTFLength(env, settings);
 	jobject event_handler = (*env)->NewGlobalRef(env, eventHandler);
+	int ret = wgTurnOn((struct go_string){
+		.str = ifname_str,
+		.n = ifname_len
+	}, tun_fd, (struct go_string){
+		.str = settings_str,
+		.n = settings_len
+	}, event_handler);
+	(*env)->ReleaseStringUTFChars(env, ifname, ifname_str);
+	(*env)->ReleaseStringUTFChars(env, settings, settings_str);
+	return ret;
+}
+
+JNIEXPORT jint JNICALL Java_com_wireguard_android_backend_GoBackend_wgTurnOnDhcp(JNIEnv *env, jclass c, jstring ifname, jstring settings, jobject eventHandler)
+{
+	const char *ifname_str = (*env)->GetStringUTFChars(env, ifname, 0);
+	size_t ifname_len = (*env)->GetStringUTFLength(env, ifname);
+	const char *settings_str = (*env)->GetStringUTFChars(env, settings, 0);
+	size_t settings_len = (*env)->GetStringUTFLength(env, settings);
+	jobject event_handler = (*env)->NewGlobalRef(env, eventHandler);
 	int ret = wgTurnOnDhcp((struct go_string){
 		.str = ifname_str,
 		.n = ifname_len
-						    }, /* tun_fd,*/ (struct go_string){
+	}, (struct go_string){
 		.str = settings_str,
 		.n = settings_len
 	}, event_handler);
@@ -71,6 +91,11 @@ JNIEXPORT jint JNICALL Java_com_wireguard_android_backend_GoBackend_wgTurnOn(JNI
 	return ret;
 }
 
+JNIEXPORT void JNICALL Java_com_wireguard_android_backend_GoBackend_wgSetFd(JNIEnv *env, jclass c, jint handle, jint tun_fd)
+{
+	wgSetFd(handle, tun_fd);
+}
+
 JNIEXPORT void JNICALL Java_com_wireguard_android_backend_GoBackend_wgTurnOff(JNIEnv *env, jclass c, jint handle)
 {
 	jobject event_handler = wgTurnOff(handle);