Adding root support (#1)

* A: root support, DHCP setup avoid the user to set manually the proxy on the device he wants to connect to the hotspot

* U: README.md

README.md

@@ -1,4 +1,4 @@
-# Share internet via Wifi direct on Android
+# Share internet via Wifi direct on Android [Root]
 
 ## Direct Net Share
 
@@ -9,7 +9,7 @@ Requirements
 ------------
 - Launch the app in the host device.
 - Connect to the host device using the `ssid` and `password` displayed in the app.
-- On the other device, go to `Settings` -> `Wifi` -> Long click the current network -> `Modify network` -> `Advanced Options` -> and use the proxy settings displayed in the app.
+- No need to setup a proxy on the device(s) you wish to connect. The ip is forwarded thanks to the root rights.
 
 Repository overview
 -------------------

app/build.gradle

@@ -1,4 +1,5 @@
 apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
 
 android {
     compileSdkVersion 26
@@ -15,9 +16,19 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
+    kotlin {
+        experimental {
+            coroutines 'enable'
+        }
+    }
 }
 
 dependencies {
     implementation 'com.android.support:appcompat-v7:26.1.0'
     compile project(':direct-share')
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:0.22.5"
+}
+repositories {
+    mavenCentral()
 }

app/src/main/AndroidManifest.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="shinil.direct_share">
+
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"

app/src/main/java/shinil/direct_share/MainActivity.kt

@@ -0,0 +1,74 @@
+package shinil.direct_share
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import android.net.ConnectivityManager
+import android.os.Bundle
+import android.support.v7.app.AppCompatActivity
+import android.support.v7.widget.SwitchCompat
+import android.util.Log
+import android.widget.CompoundButton
+import android.widget.TextView
+import kotlinx.coroutines.experimental.launch
+import shinil.direct.share.DirectNetShare
+
+class MainActivity : AppCompatActivity() {
+    private lateinit var infoTv: TextView
+    private val rootManager = RootManager()
+    private val groupCreatedListener = DirectNetShare.GroupCreatedListener { ssid, password -> infoTv.text = String.format("SSID : %s\nPassword : %s", ssid, password) }
+    private lateinit var share: DirectNetShare
+    private val onCheckedChangeListener = CompoundButton.OnCheckedChangeListener { _, isChecked ->
+        if (isChecked) {
+            checkWifiAndStart()
+        } else {
+            stopShare()
+        }
+    }
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_main)
+        infoTv = findViewById(R.id.info)
+        (findViewById<SwitchCompat>(R.id.wifi_switch)).setOnCheckedChangeListener(onCheckedChangeListener)
+    }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        stopShare()
+    }
+
+    private fun checkWifiAndStart() {
+        if (!Utils.isWifiEnabled(applicationContext)) {
+            registerReceiver(object : BroadcastReceiver() {
+                override fun onReceive(context: Context, intent: Intent) {
+                    if (intent.action != null && intent.action == ConnectivityManager.CONNECTIVITY_ACTION) {
+                        val noConnectivity = intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false)
+                        if (!noConnectivity) {
+                            startShare()
+                            unregisterReceiver(this)
+                        }
+                    }
+                }
+            }, IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION))
+            Utils.enableWifi(applicationContext)
+        } else {
+            startShare()
+        }
+    }
+
+    private fun startShare() {
+        share = DirectNetShare(this@MainActivity, groupCreatedListener)
+        share.start()
+        launch {
+            val success = rootManager.dhcpSetup()
+            Log.d("MainActivity", "DHCP setup successful? $success")
+        }
+    }
+
+    private fun stopShare() {
+        share.stop()
+        infoTv.text = ""
+    }
+}

app/src/main/java/shinil/direct_share/RootManager.kt

@@ -0,0 +1,32 @@
+package shinil.direct_share
+
+import android.util.Log
+import java.util.*
+
+class RootManager {
+    suspend fun dhcpSetup(): Boolean {
+        var success = true
+        success = success && runRootCommand("echo 1 > /proc/sys/net/ipv4/ip_forward")
+        success = success && runRootCommand("iptables -F")
+        success = success && runRootCommand("iptables -t nat -A POSTROUTING  -j MASQUERADE")
+        success = success && runRootCommand("iptables -A FORWARD -j ACCEPT")
+        success = success && runRootCommand("iptables -t nat -A PREROUTING  -p udp --dport 53 -j DNAT --to-destination 8.8.8.8:53")
+        success = success && runRootCommand("iptables -A FORWARD -p udp -d 8.8.8.8 --dport 53 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT")
+        return success
+    }
+
+    /**
+     * Warning: keep the 'suspend' here.
+     * waitFor documentation: Causes the current thread to wait, if necessary, until the process represented by this Process object has terminated.
+     */
+    private suspend fun runRootCommand(command: String): Boolean {
+        val commands = arrayOf("su", "-c", command)
+        val start: Long = System.currentTimeMillis()
+        val process: Process = Runtime.getRuntime().exec(commands)
+        val result = process.waitFor()
+        val end: Long = System.currentTimeMillis()
+        Log.d("RootManager", "Command ${Arrays.toString(commands)} executed in ${end - start} ms " +
+                " with result $result")
+        return result == 0
+    }
+}

app/src/main/java/shinil/direct_share/U.java → app/src/main/java/shinil/direct_share/Utils.java

@@ -7,7 +7,7 @@
  * @author shinilms
  */
 
-public final class U {
+public final class Utils {
 
     public static boolean enableWifi(Context context) {
         WifiManager wifiManager = (WifiManager) context.getApplicationContext().

app/src/main/res/layout/activity_main.xml

@@ -1,24 +1,21 @@
 <?xml version="1.0" encoding="utf-8"?>
-<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    tools:context="shinil.direct_share.MainActivity"
-    android:padding="16dp">
-    <TextView
-        android:id="@+id/text_view_info"
+    android:orientation="vertical"
+    android:padding="16dp"
+    tools:context="shinil.direct_share.MainActivity">
+
+    <android.support.v7.widget.SwitchCompat
+        android:id="@+id/wifi_switch"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:layout_alignParentTop="true"
-        android:layout_centerHorizontal="true"
-        android:layout_marginTop="20dp"
-        android:textSize="20sp"
-        android:text="Creating group.."/>
+        android:text="Enable Wifi" />
+
     <TextView
-        android:id="@+id/text_view_hint"
+        android:id="@+id/info"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:layout_below="@id/text_view_info"
-        android:layout_centerHorizontal="true"
-        android:layout_marginTop="40dp"/>
-</RelativeLayout>
+        android:layout_marginTop="40dp" />
+</LinearLayout>

build.gradle

@@ -1,14 +1,16 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
-
+    ext.kotlin_version = '1.2.41'
+
     repositories {
         google()
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.0.0'
-
+        classpath 'com.android.tools.build:gradle:3.1.2'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Mon Dec 11 12:55:17 IST 2017
+#Thu May 24 11:27:11 GMT 2018
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-all.zip