From 8028d708cbf7d19f4bb6312eac731ad8c16182f0 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Tue, 24 Jul 2018 14:53:43 +0200
Subject: [PATCH] tools: let wg(8) play with userspace implementation

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 app/tools/CMakeLists.txt                      |  1 +
 app/tools/libwg-go/Makefile                   |  2 +-
 .../git.zx2c4.com/wireguard-go/api-android.go | 48 +++++++++++++++----
 app/tools/wireguard-go                        |  2 +-
 4 files changed, 42 insertions(+), 11 deletions(-)

diff --git a/app/tools/CMakeLists.txt b/app/tools/CMakeLists.txt
index bc6e6745..840e9f59 100644
--- a/app/tools/CMakeLists.txt
+++ b/app/tools/CMakeLists.txt
@@ -21,6 +21,7 @@ add_custom_target(libwg-go.so WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/lib
     ANDROID_TOOLCHAIN_ROOT=${ANDROID_TOOLCHAIN_ROOT}
     ANDROID_LLVM_TRIPLE=${ANDROID_LLVM_TRIPLE}
     ANDROID_SYSROOT=${ANDROID_SYSROOT}
+    ANDROID_PACKAGE_NAME=${ANDROID_PACKAGE_NAME}
     CFLAGS=${CMAKE_C_FLAGS}\ -Wno-unused-command-line-argument
     LDFLAGS=${CMAKE_SHARED_LINKER_FLAGS}\ -fuse-ld=gold
     DESTDIR=${CMAKE_LIBRARY_OUTPUT_DIRECTORY}
diff --git a/app/tools/libwg-go/Makefile b/app/tools/libwg-go/Makefile
index 31f41a46..4e86a546 100644
--- a/app/tools/libwg-go/Makefile
+++ b/app/tools/libwg-go/Makefile
@@ -54,5 +54,5 @@ $(DESTDIR)/libwg-go.so: $(FILES) src/git.zx2c4.com/wireguard-go/api-android.go s
 	mkdir -p $(subst ../wireguard-go/,./src/git.zx2c4.com/wireguard-go/,$(dir $(FILES)))
 	$(foreach FILE,$(FILES),ln -sfrt $(subst ../wireguard-go/,./src/git.zx2c4.com/wireguard-go/,$(dir $(FILE))) $(FILE);)
 	GOPATH=$(PWD) go get -v -d git.zx2c4.com/wireguard-go
-	GOPATH=$(PWD) go build -v -o $(DESTDIR)/libwg-go.so -buildmode c-shared git.zx2c4.com/wireguard-go
+	GOPATH=$(PWD) go build -ldflags="-X main.socketDirectory=/data/data/$(ANDROID_PACKAGE_NAME)/cache/wireguard" -v -o $(DESTDIR)/libwg-go.so -buildmode c-shared git.zx2c4.com/wireguard-go
 	go version > .gobuildversion
diff --git a/app/tools/libwg-go/src/git.zx2c4.com/wireguard-go/api-android.go b/app/tools/libwg-go/src/git.zx2c4.com/wireguard-go/api-android.go
index d1b53849..4d87acc8 100644
--- a/app/tools/libwg-go/src/git.zx2c4.com/wireguard-go/api-android.go
+++ b/app/tools/libwg-go/src/git.zx2c4.com/wireguard-go/api-android.go
@@ -16,6 +16,7 @@ import (
 	"io/ioutil"
 	"log"
 	"math"
+	"net"
 	"os"
 	"os/signal"
 	"runtime"
@@ -33,11 +34,16 @@ func (l AndroidLogger) Write(p []byte) (int, error) {
 	return len(p), nil
 }
 
-var tunnelHandles map[int32]*Device
+type TunnelHandle struct {
+	device *Device
+	uapi   net.Listener
+}
+
+var tunnelHandles map[int32]TunnelHandle
 
 func init() {
 	roamingDisabled = true
-	tunnelHandles = make(map[int32]*Device)
+	tunnelHandles = make(map[int32]TunnelHandle)
 	signals := make(chan os.Signal)
 	signal.Notify(signals, unix.SIGUSR2)
 	go func() {
@@ -85,6 +91,29 @@ func wgTurnOn(ifnameRef string, tun_fd int32, settings string) int32 {
 		return -1
 	}
 
+	uapiFile, err := UAPIOpen(name)
+	if err != nil {
+		unix.Close(int(tun_fd))
+		logger.Error.Println(err)
+		return -1
+	}
+	uapi, err := UAPIListen(name, uapiFile)
+	if err != nil {
+		uapiFile.Close()
+		unix.Close(int(tun_fd))
+		logger.Error.Println(err)
+		return -1
+	}
+	go func() {
+		for {
+			conn, err := uapi.Accept()
+			if err != nil {
+				return
+			}
+			go ipcHandle(device, conn)
+		}
+	}()
+
 	device.Up()
 	logger.Info.Println("Device started")
 
@@ -98,27 +127,28 @@ func wgTurnOn(ifnameRef string, tun_fd int32, settings string) int32 {
 		unix.Close(int(tun_fd))
 		return -1
 	}
-	tunnelHandles[i] = device
+	tunnelHandles[i] = TunnelHandle{device: device, uapi: uapi}
 	return i
 }
 
 //export wgTurnOff
 func wgTurnOff(tunnelHandle int32) {
-	device, ok := tunnelHandles[tunnelHandle]
+	handle, ok := tunnelHandles[tunnelHandle]
 	if !ok {
 		return
 	}
 	delete(tunnelHandles, tunnelHandle)
-	device.Close()
+	handle.uapi.Close()
+	handle.device.Close()
 }
 
 //export wgGetSocketV4
 func wgGetSocketV4(tunnelHandle int32) int32 {
-	device, ok := tunnelHandles[tunnelHandle]
+	handle, ok := tunnelHandles[tunnelHandle]
 	if !ok {
 		return -1
 	}
-	native, ok := device.net.bind.(*NativeBind)
+	native, ok := handle.device.net.bind.(*NativeBind)
 	if !ok {
 		return -1
 	}
@@ -138,11 +168,11 @@ func wgGetSocketV4(tunnelHandle int32) int32 {
 
 //export wgGetSocketV6
 func wgGetSocketV6(tunnelHandle int32) int32 {
-	device, ok := tunnelHandles[tunnelHandle]
+	handle, ok := tunnelHandles[tunnelHandle]
 	if !ok {
 		return -1
 	}
-	native, ok := device.net.bind.(*NativeBind)
+	native, ok := handle.device.net.bind.(*NativeBind)
 	if !ok {
 		return -1
 	}
diff --git a/app/tools/wireguard-go b/app/tools/wireguard-go
index 6b3b1c3b..3ad3e83c 160000
--- a/app/tools/wireguard-go
+++ b/app/tools/wireguard-go
@@ -1 +1 @@
-Subproject commit 6b3b1c3b918fcb9bbf1d876ad6d58c38932a2469
+Subproject commit 3ad3e83c7aea762c7030b7aa7485f48083d7d9a9