feat: add android

.github/workflows/build-android.yml

@@ -0,0 +1,91 @@
+name: Build Android
+
+on:
+  release:
+    types: [ published ]
+  push:
+    paths:
+      - "**/*.go"
+      - "go.mod"
+      - "go.sum"
+      - ".github/workflows/*.yml"
+  pull_request:
+    types:
+      - opened
+    paths:
+      - "**/*.go"
+      - "go.mod"
+      - "go.sum"
+
+permissions: write-all
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout codebase
+        uses: actions/checkout@v3
+
+      - name: Set up Go
+        run: |
+          wget https://go.dev/dl/go1.21.3.linux-amd64.tar.gz
+          sudo tar -C /usr/local -xzf go1.21.3.linux-amd64.tar.gz
+          export PATH=$PATH:/usr/local/go/bin
+
+      - name: Get project dependencies
+        run: go mod download
+
+      - name: Build Android AAR
+        run: |
+          go env
+          go install golang.org/x/mobile/cmd/gomobile@latest
+          go get golang.org/x/mobile/bind@latest
+          export PATH="/home/runner/go/bin:${PATH}"
+          mkdir -p build_assets
+          sudo apt update && sudo apt install openjdk-17-jdk
+          export JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64
+          export NDK_LTS_VERSION=23.2.8568313
+          export SDK_TOOLS_VERSION=10406996
+          export ANDROID_PLATFORM_VERSION=24
+          export ANDROID_HOME="/home/runner/android-sdk"
+          export ANDROID_SDK_ROOT=$ANDROID_HOME
+          export CMDLINE_TOOLS_ROOT="${ANDROID_HOME}/cmdline-tools/latest/bin"
+          export ADB_INSTALL_TIMEOUT=120
+          export PATH="${ANDROID_HOME}/emulator:${ANDROID_HOME}/cmdline-tools/latest/bin:${ANDROID_HOME}/tools:${ANDROID_HOME}/tools/bin:${ANDROID_HOME}/platform-tools:${ANDROID_HOME}/platform-tools/bin:${PATH}"
+          export ANDROID_NDK_HOME="/home/runner/android-sdk/ndk/${NDK_LTS_VERSION}"
+          export ANDROID_NDK_ROOT="${ANDROID_NDK_HOME}"
+          mkdir -p ${ANDROID_HOME}/cmdline-tools 
+          mkdir ${ANDROID_HOME}/platforms
+          mkdir ${ANDROID_HOME}/ndk
+          wget -O /tmp/cmdline-tools.zip -t 5 --no-verbose "https://dl.google.com/android/repository/commandlinetools-linux-${SDK_TOOLS_VERSION}_latest.zip"
+          unzip -q /tmp/cmdline-tools.zip -d ${ANDROID_HOME}/cmdline-tools
+          rm /tmp/cmdline-tools.zip
+          mv ${ANDROID_HOME}/cmdline-tools/cmdline-tools ${ANDROID_HOME}/cmdline-tools/latest
+          echo y | ${CMDLINE_TOOLS_ROOT}/sdkmanager "build-tools;${ANDROID_PLATFORM_VERSION}.0.0"
+          echo y | ${CMDLINE_TOOLS_ROOT}/sdkmanager "platforms;android-${ANDROID_PLATFORM_VERSION}"
+          echo y | ${CMDLINE_TOOLS_ROOT}/sdkmanager "ndk;${NDK_LTS_VERSION}"
+          sudo apt install -y --no-install-recommends g++ libc6-dev
+          gomobile init
+          gomobile bind -target=android -o build_assets/zju-connect.aar ./mobile
+
+      - name: Upload artifact
+        if: github.event_name != 'release'
+        uses: actions/upload-artifact@v3
+        with:
+          name: zju-connect-android-aar
+          path: build_assets/*
+
+      - name: Create ZIP archive
+        if: github.event_name == 'release'
+        run: |
+          pushd build_assets || exit 1
+          zip -9vr ../zju-connect-android-aar.zip .
+          popd || exit 1
+
+      - name: Upload release binary
+        if: github.event_name == 'release'
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+        run: |
+          gh release upload ${{ github.event.release.tag_name }} zju-connect-android-aar.zip

client/rvpn_conn.go

@@ -1,6 +1,7 @@
 package client
 
 import (
+	"errors"
 	"github.com/mythologyli/zju-connect/log"
 	"io"
 )
@@ -15,7 +16,6 @@ type RvpnConn struct {
 	recvErrCount int
 }
 
-// always success or panic
 func (r *RvpnConn) Read(p []byte) (n int, err error) {
 	for n, err = r.recvConn.Read(p); err != nil && r.recvErrCount < 5; {
 		log.Printf("Error occurred while receiving, retrying: %v", err)
@@ -24,18 +24,16 @@ func (r *RvpnConn) Read(p []byte) (n int, err error) {
 		_ = r.recvConn.Close()
 		r.recvConn, err = r.easyConnectClient.RecvConn()
 		if err != nil {
-			// TODO graceful shutdown
-			panic(err)
+			return 0, err
 		}
 		r.recvErrCount++
 		if r.recvErrCount >= 5 {
-			panic("recv retry limit exceeded.")
+			return 0, errors.New("recv error count exceeded")
 		}
 	}
 	return
 }
 
-// always success or panic
 func (r *RvpnConn) Write(p []byte) (n int, err error) {
 	for n, err = r.sendConn.Write(p); err != nil && r.sendErrCount < 5; {
 		log.Printf("Error occurred while sending, retrying: %v", err)
@@ -44,12 +42,11 @@ func (r *RvpnConn) Write(p []byte) (n int, err error) {
 		_ = r.sendConn.Close()
 		r.sendConn, err = r.easyConnectClient.SendConn()
 		if err != nil {
-			// TODO graceful shutdown
-			panic(err)
+			return 0, err
 		}
 		r.sendErrCount++
 		if r.sendErrCount >= 5 {
-			panic("send retry limit exceeded.")
+			return 0, errors.New("send error count exceeded")
 		}
 	}
 	return
@@ -75,14 +72,12 @@ func NewRvpnConn(ec *EasyConnectClient) (*RvpnConn, error) {
 	var err error
 	c.sendConn, err = ec.SendConn()
 	if err != nil {
-		log.Printf("Error occurred while creating sendConn: %v", err)
-		panic(err)
+		return nil, err
 	}
 
 	c.recvConn, err = ec.RecvConn()
 	if err != nil {
-		log.Printf("Error occurred while creating recvConn: %v", err)
-		panic(err)
+		return nil, err
 	}
 	return c, nil
 }

mobile/mobile.go

@@ -0,0 +1,45 @@
+package mobile
+
+import (
+	"github.com/mythologyli/zju-connect/client"
+	"github.com/mythologyli/zju-connect/log"
+	"github.com/mythologyli/zju-connect/stack/tun"
+)
+
+var vpnClient *client.EasyConnectClient
+
+func Login(server string, username string, password string) string {
+	log.Init()
+
+	vpnClient = client.NewEasyConnectClient(
+		server,
+		username,
+		password,
+		"",
+		false,
+		false,
+	)
+	err := vpnClient.Setup()
+	if err != nil {
+		return ""
+	}
+
+	log.Printf("EasyConnect client started")
+
+	clientIP, err := vpnClient.IP()
+	if err != nil {
+		return ""
+	}
+
+	return clientIP.String()
+}
+
+func StartStack(fd int) {
+	vpnTUNStack, err := tun.NewStack(vpnClient, "")
+	if err != nil {
+		return
+	}
+
+	vpnTUNStack.SetupTun(fd)
+	vpnTUNStack.Run()
+}

stack/gvisor/stack.go

@@ -76,7 +76,10 @@ func (ep *Endpoint) WritePackets(list stack.PacketBufferList) (int, tcpip.Error)
 		}
 
 		if ep.rvpnConn != nil {
-			n, _ := ep.rvpnConn.Write(buf)
+			n, err := ep.rvpnConn.Write(buf)
+			if err != nil {
+				panic(err)
+			}
 
 			log.DebugPrintf("Send: wrote %d bytes", n)
 			log.DebugDumpHex(buf[:n])
@@ -133,13 +136,20 @@ func NewStack(easyConnectClient *client.EasyConnectClient) (*Stack, error) {
 }
 
 func (s *Stack) Run() {
-
-	s.endpoint.rvpnConn, _ = client.NewRvpnConn(s.endpoint.easyConnectClient)
+	var err error
+	s.endpoint.rvpnConn, err = client.NewRvpnConn(s.endpoint.easyConnectClient)
+	if err != nil {
+		log.Printf("Error occurred while creating sendConn: %v", err)
+		panic(err)
+	}
 
 	// Read from VPN server and send to gVisor stack
 	for {
 		buf := make([]byte, 1500)
-		n, _ := s.endpoint.rvpnConn.Read(buf)
+		n, err := s.endpoint.rvpnConn.Read(buf)
+		if err != nil {
+			panic(err)
+		}
 
 		log.DebugPrintf("Recv: read %d bytes", n)
 		log.DebugDumpHex(buf[:n])

stack/tun/stack.go

@@ -1,3 +1,5 @@
+//go:build !android
+
 package tun
 
 import (
@@ -14,18 +16,26 @@ type Stack struct {
 }
 
 func (s *Stack) Run() {
-	s.rvpnConn, _ = client.NewRvpnConn(s.endpoint.easyConnectClient)
+	var err error
+	s.rvpnConn, err = client.NewRvpnConn(s.endpoint.easyConnectClient)
+	if err != nil {
+		log.Printf("Error occurred while creating sendConn: %v", err)
+		panic(err)
+	}
 
 	// Read from VPN server and send to TUN stack
 	go func() {
 		for {
 			buf := make([]byte, 1500)
-			n, _ := s.rvpnConn.Read(buf)
+			n, err := s.rvpnConn.Read(buf)
+			if err != nil {
+				panic(err)
+			}
 
 			log.DebugPrintf("Recv: read %d bytes", n)
 			log.DebugDumpHex(buf[:n])
 
-			err := s.endpoint.Write(buf[:n])
+			err = s.endpoint.Write(buf[:n])
 			if err != nil {
 				log.Printf("Error occurred while writing to TUN stack: %v", err)
 				panic(err)
@@ -57,7 +67,10 @@ func (s *Stack) Run() {
 			continue
 		}
 
-		_, _ = s.rvpnConn.Write(buf[:n])
+		_, err = s.rvpnConn.Write(buf[:n])
+		if err != nil {
+			panic(err)
+		}
 
 		log.DebugPrintf("Send: wrote %d bytes", n)
 		log.DebugDumpHex(buf[:n])