GoBackend: integrate into app

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/tools/CMakeLists.txt

@@ -10,3 +10,16 @@ target_compile_options(libwg-quick.so PUBLIC -O3 -std=gnu11 -Wall -pedantic -Wno
 file(GLOB WG_SOURCES wireguard/src/tools/*.c libmnl/src/*.c)
 add_executable(libwg.so ${WG_SOURCES})
 target_compile_options(libwg.so PUBLIC "-I${CMAKE_CURRENT_SOURCE_DIR}libmnl/src/" "-I${CMAKE_CURRENT_SOURCE_DIR}/libmnl/include/" "-I${CMAKE_CURRENT_SOURCE_DIR}/wireguard/src/tools/" -O3 -std=gnu11 -D_GNU_SOURCE -DHAVE_VISIBILITY_HIDDEN -DRUNSTATEDIR=\"\\\"/data/data/com.wireguard.android/cache\\\"\" -Wno-pointer-arith -Wno-unused-parameter)
+
+add_custom_target(libwg-go.so WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/libwg-go" COMMENT "Building wireguard-go" VERBATIM COMMAND make
+    ANDROID_ARCH_NAME=${ANDROID_ARCH_NAME}
+    ANDROID_C_COMPILER=${ANDROID_C_COMPILER}
+    ANDROID_TOOLCHAIN_ROOT=${ANDROID_TOOLCHAIN_ROOT}
+    ANDROID_LLVM_TRIPLE=${ANDROID_LLVM_TRIPLE}
+    ANDROID_SYSROOT=${ANDROID_SYSROOT}
+    CFLAGS=${CMAKE_C_FLAGS}\ -Wno-unused-command-line-argument
+    LDFLAGS=${CMAKE_SHARED_LINKER_FLAGS}\ -fuse-ld=gold
+    DESTDIR=${CMAKE_LIBRARY_OUTPUT_DIRECTORY}
+)
+# Hack to make it actually build as part of the default target
+add_dependencies(libwg.so libwg-go.so)

app/tools/libwg-go/.gitignore

@@ -0,0 +1,4 @@
+go/
+*.go
+libwg-go.h
+jni.o

app/tools/libwg-go/Makefile

@@ -0,0 +1,21 @@
+containing = $(foreach v,$2,$(if $(findstring $1,$v),$v))
+FILES := $(wildcard ../wireguard-go/*/*.go) $(wildcard ../wireguard-go/*.go)
+FILES := $(filter-out %/main.go $(filter-out %_linux.go,$(call containing,_,$(FILES))),$(FILES))
+
+export GOPATH := $(CURDIR)/go
+CLANG_FLAGS := --target=$(ANDROID_LLVM_TRIPLE) --gcc-toolchain=$(ANDROID_TOOLCHAIN_ROOT) --sysroot=$(ANDROID_SYSROOT)
+export CGO_CFLAGS := $(CLANG_FLAGS) $(CFLAGS)
+export CGO_LDFLAGS := $(CLANG_FLAGS) $(LDFLAGS)
+export CC := $(ANDROID_C_COMPILER)
+GO_ARCH_FILTER := case "$(ANDROID_ARCH_NAME)" in x86) echo 386 ;; x86_64) echo amd64 ;; *) echo $(ANDROID_ARCH_NAME) ;; esac
+export GOARCH := $(shell $(GO_ARCH_FILTER))
+export GOOS := android
+export CGO_ENABLED := 1
+
+$(DESTDIR)/libwg-go.so: $(FILES) api-android.go jni.c
+	find . -name '*.go' -type l -delete
+	find . -type d -empty -delete
+	mkdir -p $(subst ../wireguard-go/,./,$(dir $(FILES)))
+	$(foreach FILE,$(FILES),ln -sfrt $(subst ../wireguard-go/,./,$(dir $(FILE))) $(FILE);)
+	go get -v -d
+	go build -v -o $(DESTDIR)/libwg-go.so -buildmode c-shared

app/tools/libwg-go/api-android.go

@@ -0,0 +1,111 @@
+package main
+
+// #cgo LDFLAGS: -llog
+// #include <android/log.h>
+import "C"
+
+import (
+	"bufio"
+	"io/ioutil"
+	"log"
+	"math"
+	"os"
+	"strings"
+)
+
+type AndroidLogger struct {
+	level         C.int
+	interfaceName string
+}
+
+func (l AndroidLogger) Write(p []byte) (int, error) {
+	C.__android_log_write(l.level, C.CString("WireGuard/GoBackend/"+l.interfaceName), C.CString(string(p)))
+	return len(p), nil
+}
+
+var tunnelHandles map[int32]*Device
+
+func init() {
+	tunnelHandles = make(map[int32]*Device)
+}
+
+//export wgTurnOn
+func wgTurnOn(ifnameRef string, tun_fd int32, settings string) int32 {
+	interfaceName := string([]byte(ifnameRef))
+
+	logger := &Logger{
+		Debug: log.New(&AndroidLogger{level: C.ANDROID_LOG_DEBUG, interfaceName: interfaceName}, "", 0),
+		Info:  log.New(&AndroidLogger{level: C.ANDROID_LOG_INFO, interfaceName: interfaceName}, "", 0),
+		Error: log.New(&AndroidLogger{level: C.ANDROID_LOG_ERROR, interfaceName: interfaceName}, "", 0),
+	}
+
+	logger.Debug.Println("Debug log enabled")
+
+	tun := &NativeTun{
+		fd:     os.NewFile(uintptr(tun_fd), ""),
+		events: make(chan TUNEvent, 5),
+		errors: make(chan error, 5),
+	}
+	device := NewDevice(tun, logger)
+	device.tun.mtu = DefaultMTU //TODO: make dynamic
+
+	bufferedSettings := bufio.NewReadWriter(bufio.NewReader(strings.NewReader(settings)), bufio.NewWriter(ioutil.Discard))
+	setError := ipcSetOperation(device, bufferedSettings)
+	if setError != nil {
+		logger.Debug.Println(setError)
+		return -1
+	}
+
+	device.Up()
+	logger.Info.Println("Device started")
+
+	var i int32
+	for i = 0; i < math.MaxInt32; i++ {
+		if _, exists := tunnelHandles[i]; !exists {
+			break
+		}
+	}
+	if i == math.MaxInt32 {
+		return -1
+	}
+	tunnelHandles[i] = device
+	return i
+}
+
+//export wgTurnOff
+func wgTurnOff(tunnelHandle int32) {
+	device, ok := tunnelHandles[tunnelHandle]
+	if !ok {
+		return
+	}
+	delete(tunnelHandles, tunnelHandle)
+	device.Close()
+}
+
+//export wgGetSocketV4
+func wgGetSocketV4(tunnelHandle int32) int32 {
+	device, ok := tunnelHandles[tunnelHandle]
+	if !ok {
+		return -1
+	}
+	native, ok := device.net.bind.(NativeBind)
+	if !ok {
+		return -1
+	}
+	return int32(native.sock4)
+}
+
+//export wgGetSocketV6
+func wgGetSocketV6(tunnelHandle int32) int32 {
+	device, ok := tunnelHandles[tunnelHandle]
+	if !ok {
+		return -1
+	}
+	native, ok := device.net.bind.(NativeBind)
+	if !ok {
+		return -1
+	}
+	return int32(native.sock6)
+}
+
+func main() {}

app/tools/libwg-go/jni.c

@@ -0,0 +1,40 @@
+#include <jni.h>
+
+struct go_string { const char *str; long n; };
+extern int wgTurnOn(struct go_string ifname, int tun_fd, struct go_string settings);
+extern void wgTurnOff(int handle);
+extern int wgGetSocketV4(int handle);
+extern int wgGetSocketV6(int handle);
+
+JNIEXPORT jint JNICALL Java_com_wireguard_android_backend_GoBackend_wgTurnOn(JNIEnv *env, jclass c, jstring ifname, jint tun_fd, jstring settings)
+{
+	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);
+	int ret = wgTurnOn((struct go_string){
+		.str = ifname_str,
+		.n = ifname_len
+	}, tun_fd, (struct go_string){
+		.str = settings_str,
+		.n = settings_len
+	});
+	(*env)->ReleaseStringUTFChars(env, ifname, ifname_str);
+	(*env)->ReleaseStringUTFChars(env, settings, settings_str);
+	return ret;
+}
+
+JNIEXPORT void JNICALL Java_com_wireguard_android_backend_GoBackend_wgTurnOff(JNIEnv *env, jclass c, jint handle)
+{
+	wgTurnOff(handle);
+}
+
+JNIEXPORT jint JNICALL Java_com_wireguard_android_backend_GoBackend_wgGetSocketV4(JNIEnv *env, jclass c, jint handle)
+{
+	return wgGetSocketV4(handle);
+}
+
+JNIEXPORT jint JNICALL Java_com_wireguard_android_backend_GoBackend_wgGetSocketV6(JNIEnv *env, jclass c, jint handle)
+{
+	return wgGetSocketV6(handle);
+}