WIP: netstack: implement dhcp and ipvlan

3 files changed, 178 insertions, 2 deletions

diff --git a/tunnel/tools/libwg-go/api-android.go b/tunnel/tools/libwg-go/api-android.go
index db056f67..2fb6e40f 100644
--- a/tunnel/tools/libwg-go/api-android.go
+++ b/tunnel/tools/libwg-go/api-android.go
@@ -11,7 +11,9 @@ package main
 import "C"
 
 import (
+	"context"
 	"fmt"
+	"log"
 	"math"
 	"net"
 	"os"
@@ -26,6 +28,15 @@ import (
 	"golang.zx2c4.com/wireguard/device"
 	"golang.zx2c4.com/wireguard/ipc"
 	"golang.zx2c4.com/wireguard/tun"
+	"golang.zx2c4.com/wireguard/tun/netstack"
+	"golang.zx2c4.com/wireguard/tun/netstack/ipvlan"
+
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
+	"gvisor.dev/gvisor/pkg/tcpip/network/ipv6"
+	"gvisor.dev/gvisor/pkg/tcpip/stack"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
 )
 
 type AndroidLogger struct {
@@ -50,6 +61,8 @@ type TunnelHandle struct {
 	device *device.Device
 	uapi   net.Listener
 	eventHandler unsafe.Pointer
+	cancel context.CancelFunc
+	master *ipvlan.IPVLANMaster
 }
 
 var tunnelHandles map[int32]TunnelHandle
@@ -152,6 +165,166 @@ func wgTurnOn(interfaceName string, tunFd int32, settings string, eventHandler u
 	return i
 }
 
+func createNetTUNWithStack(stack *stack.Stack, nicID tcpip.NICID, localAddresses []net.IP, dnsServers []net.IP, mtu int) (tun.Device, *netstack.Net, *ipvlan.IPVLANMaster, error) {
+	dev, ep, err := netstack.NewNetTUN(stack, mtu)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+
+	master := ipvlan.NewIPVLANMaster(ep)
+
+	addrs := make([]tcpip.Address, 0, len(localAddresses))
+	for _, addr := range localAddresses {
+		addrs = append(addrs, tcpip.Address(addr))
+	}
+	ipvlanEP := master.NewIPVLAN(addrs)
+
+	tcpipErr := stack.CreateNIC(nicID, ipvlanEP)
+	if tcpipErr != nil {
+		return nil, nil, nil, fmt.Errorf("CreateNIC: %v", tcpipErr)
+	}
+
+	tnet, err := netstack.NewNetAdapter(stack, nicID, localAddresses, dnsServers)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+
+	return dev, tnet, master, nil
+}
+
+//export wgTurnOnDhcp
+func wgTurnOnDhcp(interfaceName string, settings string, eventHandler unsafe.Pointer) int32 {
+	tag := cstring("WireGuard/GoBackend/" + interfaceName)
+	logger := &device.Logger{
+		Verbosef: AndroidLogger{level: C.ANDROID_LOG_DEBUG, tag: tag}.Printf,
+		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)
+
+	// FIXME IP address
+	ipStr := "fe80::101"
+	// FIXME name
+	name := "wg0"
+	var tundev tun.Device
+	var tnet *netstack.Net
+	tundev, tnet, master, err := createNetTUNWithStack(
+		stack,
+		1,
+		[]net.IP{net.ParseIP(ipStr)},
+		//                []net.IP{net.ParseIP("fe80::1")},
+		[]net.IP{net.ParseIP("fe80::1")},
+		1420)
+	if err != nil {
+		log.Panic(err)
+	}
+
+	logger.Verbosef("Attaching to netstack interface")
+	device := device.NewDevice(tundev, conn.NewStdNetBind(), logger)
+
+	err = device.IpcSet(settings)
+	if err != nil {
+		logger.Errorf("IpcSet: %v", err)
+		return -1
+	}
+	device.DisableSomeRoamingForBrokenMobileSemantics()
+
+	var uapi net.Listener
+
+	uapiFile, err := ipc.UAPIOpen(name)
+	if err != nil {
+		logger.Errorf("UAPIOpen: %v", err)
+	} else {
+		uapi, err = ipc.UAPIListen(name, uapiFile)
+		if err != nil {
+			uapiFile.Close()
+			logger.Errorf("UAPIListen: %v", err)
+		} else {
+			go func() {
+				for {
+					conn, err := uapi.Accept()
+					if err != nil {
+						return
+					}
+					go device.IpcHandle(conn)
+				}
+			}()
+		}
+	}
+
+	err = device.Up()
+	if err != nil {
+		logger.Errorf("Unable to bring up device: %v", err)
+		uapiFile.Close()
+		device.Close()
+		return -1
+	}
+	logger.Verbosef("Device started")
+
+	var i int32
+	for i = 0; i < math.MaxInt32; i++ {
+		if _, exists := tunnelHandles[i]; !exists {
+			break
+		}
+	}
+	if i == math.MaxInt32 {
+		logger.Errorf("Unable to find empty handle")
+		uapiFile.Close()
+		device.Close()
+		return -1
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+
+	tunnelHandles[i] = TunnelHandle{device: device, uapi: uapi, eventHandler: eventHandler, cancel: cancel, master: master}
+
+	go func(ctx context.Context) {
+		logger.Verbosef("Start dhcp client")
+		src, err := net.ResolveUDPAddr("udp6", fmt.Sprintf("[%s%%1]:546", ipStr))
+		if err != nil {
+			logger.Errorf("ResolveUDPAddr: %v", err)
+			return
+		}
+
+		var dst *net.UDPAddr
+		dst = nil
+
+		conn, err := tnet.DialUDP(src, dst)
+		if err != nil {
+			logger.Errorf("DialUDP: %v", err)
+			return
+		}
+
+		logger.Verbosef("Conn: %v %v %v", src, dst, conn)
+		hwAddr := []byte("   101")
+		addrs, err := netstack.RunDhcp(ctx, conn, hwAddr)
+
+		if err != nil {
+			logger.Errorf("DHCP: %v", err)
+			return
+		}
+
+		logger.Verbosef("DHCP finished")
+		for _, addr := range addrs {
+			logger.Verbosef("Address: %v", addr)
+		}
+
+		// TODO move to wgSetTunFd
+		// tunEP := newTun(stack, 2, "tun0")
+		// master.SetIntEP(tunEP)
+	}(ctx)
+
+	logger.Verbosef("Before wgOnEvent %v", eventHandler)
+	C.wgOnEvent(tunnelHandles[i].eventHandler, C.CString("FOOBAR"))
+	C.wgOnEvent(tunnelHandles[i].eventHandler, C.CString("Called wgTurnOn"))
+	logger.Verbosef("After wgOnEvent")
+	return i
+}
+
 //export wgTurnOff
 func wgTurnOff(tunnelHandle int32) unsafe.Pointer {
 	handle, ok := tunnelHandles[tunnelHandle]
diff --git a/tunnel/tools/libwg-go/go.mod b/tunnel/tools/libwg-go/go.mod
index e64d2fb1..6fdb520c 100644
--- a/tunnel/tools/libwg-go/go.mod
+++ b/tunnel/tools/libwg-go/go.mod
@@ -12,3 +12,5 @@ require (
 	golang.org/x/net v0.0.0-20220516155154-20f960328961 // indirect
 	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
diff --git a/tunnel/tools/libwg-go/jni.c b/tunnel/tools/libwg-go/jni.c
index 52bec1e8..de6a1e85 100644
--- a/tunnel/tools/libwg-go/jni.c
+++ b/tunnel/tools/libwg-go/jni.c
@@ -13,6 +13,7 @@
 
 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 *wgTurnOff(int handle);
 extern int wgGetSocketV4(int handle);
 extern int wgGetSocketV6(int handle);
@@ -58,10 +59,10 @@ 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){
+	int ret = wgTurnOnDhcp((struct go_string){
 		.str = ifname_str,
 		.n = ifname_len
-	}, tun_fd, (struct go_string){
+						    }, /* tun_fd,*/ (struct go_string){
 		.str = settings_str,
 		.n = settings_len
 	}, event_handler);