From bf491944d4e2920833b05f4b3746f3bda68f18b3 Mon Sep 17 00:00:00 2001
From: vadym <vadym.vikulin@gmail.com>
Date: Mon, 29 Jun 2020 02:30:31 -0700
Subject: [PATCH] 1. fix for DNS unavailability

---
 .../chronosx88/yggdrasil/MainActivity.kt      |  8 +++---
 .../yggdrasil/YggdrasilTunService.kt          | 27 ++++++++++++++++++-
 2 files changed, 30 insertions(+), 5 deletions(-)

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 c7c412b..218c8f4 100644
--- a/app/src/main/java/io/github/chronosx88/yggdrasil/MainActivity.kt
+++ b/app/src/main/java/io/github/chronosx88/yggdrasil/MainActivity.kt
@@ -127,7 +127,7 @@ class MainActivity : AppCompatActivity() {
                     // No services have actually been discovered yet, so this method
                     // can often be left blank.  Code for peer discovery goes in the
                     // onReceive method, detailed below.
-                    showToast("discover peers success")
+                    //showToast("discover peers success")
                 }
 
                 override fun onFailure(reasonCode: Int) {
@@ -383,11 +383,11 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun updateThisDevice(wifiP2pDevice: WifiP2pDevice) {
-        showToast("update device:"+wifiP2pDevice.deviceName+" address:"+wifiP2pDevice.deviceAddress)
+        //showToast("update device:"+wifiP2pDevice.deviceName+" address:"+wifiP2pDevice.deviceAddress)
     }
 
     private fun setIsWifiP2pEnabled(b: Boolean) {
-        showToast("WifiP2pEnabled="+b)
+        //showToast("WifiP2pEnabled="+b)
     }
 
     /** register the BroadcastReceiver with the intent values to be matched  */
@@ -413,7 +413,7 @@ class MainActivity : AppCompatActivity() {
             // If an AdapterView is backed by this data, notify it // of the change. For instance, if you have a ListView of available // peers, trigger an update.
             //((WiFiPeerListAdapter) getListAdapter()).notifyDataSetChanged(); if (peers.size() == 0) { Log.d(WiFiDirectActivity.TAG, "No devices found"); return; } }
             //just show message
-            showToast("available peers:"+this@MainActivity.wirelessPeers.size)
+            //showToast("available peers:"+this@MainActivity.wirelessPeers.size)
         }
 
     }
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 f4e4729..ea4b323 100644
--- a/app/src/main/java/io/github/chronosx88/yggdrasil/YggdrasilTunService.kt
+++ b/app/src/main/java/io/github/chronosx88/yggdrasil/YggdrasilTunService.kt
@@ -1,7 +1,10 @@
 package io.github.chronosx88.yggdrasil
 
 import android.app.PendingIntent
+import android.content.Context
 import android.content.Intent
+import android.net.ConnectivityManager
+import android.net.Network
 import android.net.VpnService
 import android.os.ParcelFileDescriptor
 import android.system.OsConstants
@@ -17,6 +20,7 @@ import kotlinx.coroutines.*
 import mobile.Mobile
 import mobile.Yggdrasil
 import java.io.*
+import java.net.Inet6Address
 import java.nio.ByteBuffer
 
 
@@ -63,7 +67,6 @@ class YggdrasilTunService : VpnService() {
     private fun setupIOStreams(dns: MutableSet<DNSInfo>){
         address = ygg.addressString
         var builder = Builder()
-            .addAddress(address, 7)
             .allowFamily(OsConstants.AF_INET)
             .setMtu(MAX_PACKET_SIZE)
         if (dns.size > 0) {
@@ -72,6 +75,12 @@ class YggdrasilTunService : VpnService() {
                 builder.addDnsServer(d.address)
             }
         }
+        /*
+        fix for DNS unavailability
+         */
+        if(!hasIpv6DefaultRoute()){
+            builder.addRoute("::",0)
+        }
         if(tunInterface!=null){
             tunInterface!!.close()
             tunInputStream!!.close()
@@ -193,4 +202,20 @@ class YggdrasilTunService : VpnService() {
         super.onDestroy()
         stopSelf()
     }
+
+    private fun hasIpv6DefaultRoute(): Boolean {
+        val cm =
+            getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
+        val networks = cm.allNetworks
+        for (network in networks) {
+            val linkProperties = cm.getLinkProperties(network)
+            val routes = linkProperties.routes
+            for (route in routes) {
+                if (route.isDefaultRoute && route.gateway is Inet6Address) {
+                    return true
+                }
+            }
+        }
+        return false
+    }
 }