From 28b72376a76de3ed597e61c68abf6d36e4d0e6e6 Mon Sep 17 00:00:00 2001
From: ChronosX88 <chronosx88@gmail.com>
Date: Sun, 2 Feb 2020 22:34:58 +0400
Subject: [PATCH] Make starting VPN service and running Yggdrasil (traffic
 hooks into Yggdrasil dummy interface)

---
 app/src/main/AndroidManifest.xml              |  8 +-
 .../chronosx88/yggdrasil/MainActivity.kt      | 29 +++++-
 .../io/github/chronosx88/yggdrasil/Utils.kt   | 65 -------------
 .../chronosx88/yggdrasil/YggdrasilService.kt  | 44 ---------
 .../yggdrasil/YggdrasilTunService.kt          | 96 +++++++++++++++----
 .../yggdrasil/models/config/Config.kt         |  1 +
 6 files changed, 105 insertions(+), 138 deletions(-)
 delete mode 100644 app/src/main/java/io/github/chronosx88/yggdrasil/YggdrasilService.kt

diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 1686b7b..4e5b87b 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -2,7 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
         xmlns:tools="http://schemas.android.com/tools"
         package="io.github.chronosx88.yggdrasil">
-
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <application
             android:allowBackup="true"
             android:icon="@mipmap/ic_launcher"
@@ -14,17 +15,12 @@
         <service
                 android:name=".YggdrasilTunService"
                 android:enabled="true"
-                android:exported="true"></service>
-        <service
-                android:name=".YggdrasilService"
-                android:enabled="true"
                 android:exported="true"
                 android:permission="android.permission.BIND_VPN_SERVICE">
             <intent-filter>
                 <action android:name="android.net.VpnService"/>
             </intent-filter>
         </service>
-
         <activity android:name=".MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
diff --git a/app/src/main/java/io/github/chronosx88/yggdrasil/MainActivity.kt b/app/src/main/java/io/github/chronosx88/yggdrasil/MainActivity.kt
index edae20f..49e3421 100644
--- a/app/src/main/java/io/github/chronosx88/yggdrasil/MainActivity.kt
+++ b/app/src/main/java/io/github/chronosx88/yggdrasil/MainActivity.kt
@@ -1,11 +1,13 @@
 package io.github.chronosx88.yggdrasil
 
+import android.app.Activity
 import android.content.Intent
 import android.net.VpnService
 import android.os.Bundle
 import android.widget.Button
 import androidx.appcompat.app.AppCompatActivity
 
+
 class MainActivity : AppCompatActivity() {
     private var isYggStarted = false
 
@@ -16,12 +18,18 @@ class MainActivity : AppCompatActivity() {
         val connectButton = findViewById<Button>(R.id.connect_button)
         connectButton.setOnClickListener {
             if(!isYggStarted) {
-                VpnService.prepare(this)
-                val intent = Intent(this, YggdrasilTunService::class.java)
-                startService(intent)
-                connectButton.text = "Disconnect"
-                isYggStarted = true
+                // Prepare to establish a VPN connection.
+                // This method returns null if the VPN application is already prepared
+                // or if the user has previously consented to the VPN application.
+                // Otherwise, it returns an Intent to a system activity.
+                val vpnIntent = VpnService.prepare(this)
+                if (vpnIntent != null) startActivityForResult(
+                    vpnIntent,
+                    0x0F
+                )
+                else onActivityResult(0x0F, Activity.RESULT_OK, null)
             } else {
+                // FIXME fix this shit, this code doesn't stop service for some reasons
                 val intent = Intent(this, YggdrasilTunService::class.java)
                 stopService(intent)
                 connectButton.text = "Connect"
@@ -29,4 +37,15 @@ class MainActivity : AppCompatActivity() {
             }
         }
     }
+
+    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
+        super.onActivityResult(requestCode, resultCode, data)
+        if (requestCode == 0x0F && resultCode == Activity.RESULT_OK) {
+            val intent = Intent(this, YggdrasilTunService::class.java)
+            startService(intent)
+            val connectButton = findViewById<Button>(R.id.connect_button)
+            connectButton.text = "Disconnect"
+            isYggStarted = true
+        }
+    }
 }
diff --git a/app/src/main/java/io/github/chronosx88/yggdrasil/Utils.kt b/app/src/main/java/io/github/chronosx88/yggdrasil/Utils.kt
index 26e2d1a..0982a45 100644
--- a/app/src/main/java/io/github/chronosx88/yggdrasil/Utils.kt
+++ b/app/src/main/java/io/github/chronosx88/yggdrasil/Utils.kt
@@ -13,39 +13,6 @@ import java.lang.Runtime.getRuntime
 
 val gson = Gson()
 
-fun Context.execYgg(cmd: String) = getRuntime().exec(
-    "${yggBin.absolutePath} $cmd"
-)
-
-val Context.yggBin get() = File(filesDir, "yggdrasil-$YGGDRASIL_VERSION-linux-${CPU_ABI.let {
-        when {
-            it.contains("v7") -> "armhf"
-            it.contains("v8") -> "arm64"
-            else ->  throw Exception("Unsupported ABI")
-        } 
-    }
-}")
-
-@Throws(RuntimeException::class)
-fun Context.getYggConfig(): Config {
-    val configFile = File(filesDir, "yggdrasil.conf")
-    if(!configFile.exists()) {
-        generateYggConfig()
-    }
-    val configStr = configFile.readText()
-    val configHjsonObject = JsonValue.readHjson(configStr)
-    return gson.fromJson(configHjsonObject.toString(Stringify.PLAIN), Config::class.java)
-}
-
-fun Context.generateYggConfig() {
-    val process = execYgg("-genconf > ${filesDir.absolutePath}/yggdrasil.conf")
-    process.waitFor()
-    val configBytes = process.inputStream.readBytes()
-    val configStr = String(configBytes)
-    val configFile = File(filesDir, "yggdrasil.conf")
-    configFile.writeText(configStr)
-}
-
 fun createNativeYggConfig(config: Config): NodeConfig {
     val nativeConfig = NodeConfig()
     nativeConfig.adminListen = config.adminListen
@@ -64,36 +31,4 @@ fun Context.saveYggConfig(config: Config) {
     val configJson = gson.toJson(config)
     val configFile = File(filesDir, "yggdrasil.conf")
     configFile.writeText(configJson)
-}
-
-fun Context.installBinary() {
-    val type = "yggdrasil-$YGGDRASIL_VERSION-linux-${CPU_ABI.let {
-        when{
-            it.contains("v8") -> "arm64"
-            it.contains("v7") -> "armhf"
-            else -> throw Exception("Unsupported ABI")
-        }
-    }}"
-
-    yggBin.apply {
-        delete()
-        createNewFile()
-    }
-
-    val input = assets.open(type)
-    val output = yggBin.outputStream()
-
-    try {
-        input.copyTo(output)
-    } finally {
-        input.close(); output.close()
-    }
-
-    yggBin.setExecutable(true)
-
-    val yggConfig = getYggConfig() // it generates config automatically
-    yggConfig.ifName = "tun0"
-    saveYggConfig(yggConfig)
-
-    Log.i("Utils", "# Binary installed successfully")
 }
\ No newline at end of file
diff --git a/app/src/main/java/io/github/chronosx88/yggdrasil/YggdrasilService.kt b/app/src/main/java/io/github/chronosx88/yggdrasil/YggdrasilService.kt
deleted file mode 100644
index 98193f2..0000000
--- a/app/src/main/java/io/github/chronosx88/yggdrasil/YggdrasilService.kt
+++ /dev/null
@@ -1,44 +0,0 @@
-package io.github.chronosx88.yggdrasil
-
-import android.app.Service
-import android.content.Intent
-import kotlin.system.exitProcess
-
-class YggdrasilService : Service() {
-    private val LOG_TAG: String = YggdrasilService::class.java.simpleName
-
-    override fun onBind(intent: Intent) = null
-
-    companion object {
-        var daemon: Process? = null
-    }
-
-    private fun start() {
-        val process = execYgg("-useconffile ${filesDir.absolutePath}/yggdrasil.conf")
-        process.waitFor()
-        daemon = process
-    }
-
-    private fun stop() {
-        daemon?.destroy()
-        daemon = null
-    }
-
-    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
-        super.onStartCommand(intent, flags, startId)
-        when (intent?.action) {
-            "start" -> start()
-            "stop" -> stop()
-            "restart" -> {
-                stop(); start()
-            }
-            "exit" -> exitProcess(0)
-        }
-        return START_STICKY
-    }
-
-    override fun onDestroy() {
-        super.onDestroy()
-        stop()
-    }
-}
diff --git a/app/src/main/java/io/github/chronosx88/yggdrasil/YggdrasilTunService.kt b/app/src/main/java/io/github/chronosx88/yggdrasil/YggdrasilTunService.kt
index 3fe0fec..1f9be37 100644
--- a/app/src/main/java/io/github/chronosx88/yggdrasil/YggdrasilTunService.kt
+++ b/app/src/main/java/io/github/chronosx88/yggdrasil/YggdrasilTunService.kt
@@ -5,7 +5,18 @@ import android.content.Intent
 import android.net.VpnService
 import android.os.ParcelFileDescriptor
 import com.google.gson.Gson
+import dummy.ConduitEndpoint
+import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.cancel
+import kotlinx.coroutines.launch
+import mobile.Mobile
 import mobile.Yggdrasil
+import java.io.FileInputStream
+import java.io.FileOutputStream
+import java.io.InputStream
+import java.io.OutputStream
+import kotlin.coroutines.CoroutineContext
+import kotlin.experimental.or
 
 
 class YggdrasilTunService : VpnService() {
@@ -13,6 +24,11 @@ class YggdrasilTunService : VpnService() {
         private var isRunning: Boolean = false
     }
     private var tunInterface: ParcelFileDescriptor? = null
+    private lateinit var yggConduitEndpoint: ConduitEndpoint
+    private var tunInputStream: InputStream? = null
+    private var tunOutputStream: OutputStream? = null
+    private lateinit var readCoroutine: CoroutineContext
+    private lateinit var writeCoroutine: CoroutineContext
 
     override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
         super.onStartCommand(intent, flags, startId)
@@ -26,41 +42,85 @@ class YggdrasilTunService : VpnService() {
     }
 
     private fun setupTunInterface() {
-        if(!yggBin.exists()) {
-            installBinary()
-        }
-
         val builder = Builder()
+        val ygg = Yggdrasil()
+        var configJson = Mobile.generateConfigJSON()
+        val gson = Gson()
 
-        val yggTmp = Yggdrasil()
-        val tempYggConfig = getYggConfig()
-        tempYggConfig.ifName = "none"
-        yggTmp.startJSON(Gson().toJson(tempYggConfig).toByteArray())
-        val address = yggTmp.addressString // hack for getting generic ipv6 string from NodeID
+        var config = gson.fromJson(String(configJson), Map::class.java).toMutableMap()
+        config = fixConfig(config)
+        configJson = gson.toJson(config).toByteArray()
+
+        yggConduitEndpoint = ygg.startJSON(configJson)
+        val address = ygg.addressString // hack for getting generic ipv6 string from NodeID
 
         tunInterface = builder
             .addAddress(address, 7)
             .addRoute("0200::", 7)
             .establish()
 
-        createYggdrasilService()
+        tunInputStream = FileInputStream(tunInterface!!.fileDescriptor)
+        tunOutputStream = FileOutputStream(tunInterface!!.fileDescriptor)
+        readCoroutine = GlobalScope.launch {
+            // FIXME it will throw exception (bad file descriptor) when coroutine will be canceled
+            while (true) {
+                readPacketsFromTun()
+            }
+        }
+        writeCoroutine = GlobalScope.launch {
+            while (true) {
+                writePacketsToTun()
+            }
+        }
     }
 
-    private fun createYggdrasilService() {
-        val intent = Intent(this, YggdrasilService::class.java)
-        intent.action = "start"
-        startService(intent)
+    private fun fixConfig(config: MutableMap<Any?, Any?>): MutableMap<Any?, Any?> {
+        config["Listen"] = ""
+        config["AdminListen"] = "tcp://localhost:9001"
+        config["IfName"] = "dummy"
+        (config["SessionFirewall"] as MutableMap<Any, Any>)["Enable"] = true
+        (config["SwitchOptions"] as MutableMap<Any, Any>)["MaxTotalQueueSize"] = 1048576
+        if (config["AutoStart"] == null) {
+            val tmpMap = emptyMap<String, Boolean>().toMutableMap()
+            tmpMap["WiFi"] = false
+            tmpMap["Mobile"] = false
+            config["AutoStart"] = tmpMap
+        }
+        return config
     }
 
-    private fun stopYggdrasilService() {
-        val intent = Intent(this, YggdrasilService::class.java)
-        stopService(intent)
+    private fun readPacketsFromTun() {
+        if(tunInputStream != null) {
+            val buffer = ByteArray(1024)
+            tunInputStream!!.read(buffer)
+            if (!isBufferEmpty(buffer)) {
+                yggConduitEndpoint.send(buffer)
+            }
+        }
+    }
+
+    private fun isBufferEmpty(buffer: ByteArray): Boolean {
+        var sum: Byte = 0
+        for (i in buffer) {
+            sum.or(i)
+        }
+        return sum == 0.toByte()
+    }
+
+    private fun writePacketsToTun() {
+        if(tunOutputStream != null) {
+            val buffer = yggConduitEndpoint.recv()
+            if (!isBufferEmpty(buffer)) {
+                tunOutputStream!!.write(buffer)
+            }
+        }
     }
 
     override fun onRevoke() {
         super.onRevoke()
         isRunning = false
-        stopYggdrasilService()
+        readCoroutine.cancel()
+        writeCoroutine.cancel()
         tunInterface!!.close()
         tunInterface = null
     }
diff --git a/app/src/main/java/io/github/chronosx88/yggdrasil/models/config/Config.kt b/app/src/main/java/io/github/chronosx88/yggdrasil/models/config/Config.kt
index 5b4e3d2..085f1a9 100644
--- a/app/src/main/java/io/github/chronosx88/yggdrasil/models/config/Config.kt
+++ b/app/src/main/java/io/github/chronosx88/yggdrasil/models/config/Config.kt
@@ -2,6 +2,7 @@ package io.github.chronosx88.yggdrasil.models.config
 
 import com.google.gson.annotations.SerializedName
 
+// FIXME This is old config scheme
 data class Config (
 	@SerializedName("peers") var peers : List<String>,
 	@SerializedName("interfacePeers") var interfacePeers : Map<String, List<String>>,