Upstream proxy server support (#42)

krlvm · Dec 18, 2020 · 96f750c · DRSDavidSoft · Dec 18, 2020 · krlvm
1 parent f4bf499
commit 96f750c
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Showing 8 changed files with 137 additions and 8 deletions.
diff --git a/app/src/main/java/ru/krlvm/powertunnel/PowerTunnel.java b/app/src/main/java/ru/krlvm/powertunnel/PowerTunnel.java
@@ -1,6 +1,7 @@
 package ru.krlvm.powertunnel;
 
 import org.jitsi.dnssec.validator.ValidatingResolver;
+import org.littleshoot.proxy.ChainedProxyManager;
 import org.littleshoot.proxy.HttpFilters;
 import org.littleshoot.proxy.HttpFiltersSourceAdapter;
 import org.littleshoot.proxy.HttpProxyServer;
@@ -20,6 +21,7 @@
 
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.http.HttpRequest;
+import ru.krlvm.powertunnel.adapters.UpstreamChainedProxyAdapter;
 import ru.krlvm.powertunnel.android.managers.PTManager;
 import ru.krlvm.powertunnel.android.resolver.AndroidDohResolver;
 import ru.krlvm.powertunnel.enums.SNITrick;
@@ -83,6 +85,12 @@ public class PowerTunnel {
     private static final Set<String> GOVERNMENT_BLACKLIST = null; //= new HashSet<>();
     private static final Set<String> ISP_STUB_LIST        = null; //= new HashSet<>();
 
+    public static boolean UPSTREAM_PROXY_CACHE = false;
+    public static String UPSTREAM_PROXY_IP = null;
+    public static int UPSTREAM_PROXY_PORT = -1;
+    public static String UPSTREAM_PROXY_USERNAME = null;
+    public static String UPSTREAM_PROXY_PASSWORD = null;
+
     /**
      * PowerTunnel bootstrap
      */
@@ -171,6 +179,18 @@ public HttpFilters filterRequest(HttpRequest originalRequest, ChannelHandlerCont
                 throw new Exception("Failed to initialize MITM Manager for SNI tricks: " + ex.getMessage(), ex);
             }
         }
+
+        if(UPSTREAM_PROXY_IP != null) {
+            ChainedProxyManager manager;
+            if(UPSTREAM_PROXY_CACHE) {
+                final UpstreamChainedProxyAdapter adapter = new UpstreamChainedProxyAdapter();
+                manager = (httpRequest, queue) -> queue.add(adapter);
+            } else {
+                manager = (httpRequest, queue) -> queue.add(new UpstreamChainedProxyAdapter());
+            }
+            bootstrap.withName("Downstream").withChainProxyManager(manager);
+        }
+
         SERVER = bootstrap.start();
         RUNNING = true;
         System.out.println("[.] Server started");

diff --git a/app/src/main/java/ru/krlvm/powertunnel/adapters/UpstreamChainedProxyAdapter.java b/app/src/main/java/ru/krlvm/powertunnel/adapters/UpstreamChainedProxyAdapter.java
@@ -0,0 +1,40 @@
+package ru.krlvm.powertunnel.adapters;
+
+import org.littleshoot.proxy.ChainedProxyAdapter;
+
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.UnknownHostException;
+
+import ru.krlvm.powertunnel.PowerTunnel;
+
+public class UpstreamChainedProxyAdapter extends ChainedProxyAdapter {
+
+    private InetSocketAddress cachedAddress = null;
+
+    public UpstreamChainedProxyAdapter() {
+        if (PowerTunnel.UPSTREAM_PROXY_CACHE) {
+            try {
+                cachedAddress = getAddress();
+            } catch (UnknownHostException ex) {
+                System.out.println("[x] Failed to cache upstream proxy address: " + ex.getMessage());
+                ex.printStackTrace();
+            }
+        }
+    }
+
+    @Override
+    public InetSocketAddress getChainedProxyAddress() {
+        try {
+            return cachedAddress == null ? getAddress() : cachedAddress;
+        } catch (UnknownHostException ex) {
+            System.out.println("[x] Failed to resolve upstream proxy address: " + ex.getMessage());
+            ex.printStackTrace();
+            return null;
+        }
+    }
+
+    private InetSocketAddress getAddress() throws UnknownHostException {
+        return new InetSocketAddress(InetAddress.getByName(PowerTunnel.UPSTREAM_PROXY_IP), PowerTunnel.UPSTREAM_PROXY_PORT);
+    }
+}
diff --git a/app/src/main/java/ru/krlvm/powertunnel/android/MainActivity.java b/app/src/main/java/ru/krlvm/powertunnel/android/MainActivity.java
@@ -59,6 +59,7 @@ public class MainActivity extends AppCompatActivity {
     private Button start;
     private Handler statusHandler = new Handler();
     private Handler progressHandler = new Handler();
+    private static final long PROGRESS_DELAY = 500L;
 
     private Tun2HttpVpnService service;
     private ServiceConnection serviceConnection = new ServiceConnection() {
@@ -292,14 +293,14 @@ private void startTunnel() {
         dialog.show();
         updateStatus();
         final boolean vpn = PTManager.isVPN(this);
-        progressHandler.post(() -> {
+        progressHandler.postDelayed(() -> {
             if(vpn) {
                 startVpn();
             } else {
                 startProxy();
             }
             dialog.dismiss();
-        });
+        }, PROGRESS_DELAY);
     }
 
     private void startVpn() {
@@ -337,10 +338,10 @@ private void stopTunnel() {
         final ProgressDialog dialog = progress(false);
         dialog.show();
         updateStatus();
-        progressHandler.post(() -> {
+        progressHandler.postDelayed(() -> {
             PTManager.stopTunnel(this);
             dialog.dismiss();
-        });
+        }, PROGRESS_DELAY);
     }
 
     private ProgressDialog progress(boolean starting) {

diff --git a/app/src/main/java/ru/krlvm/powertunnel/android/fragments/SettingsFragment.java b/app/src/main/java/ru/krlvm/powertunnel/android/fragments/SettingsFragment.java
@@ -73,10 +73,13 @@ public void onCreate(Bundle savedInstanceState) {
         clearAllSelection.setOnPreferenceClickListener(this);
         findPreference(RESET_CONNECTION_SETTINGS).setOnPreferenceClickListener(this);
         findPreference("theme").setOnPreferenceChangeListener(this);
-        findPreference("proxy_mode").setOnPreferenceChangeListener(this);
         findPreference("sni").setOnPreferenceChangeListener(this);
 
+        findPreference("proxy_mode").setOnPreferenceChangeListener(this);
+        findPreference("upstream_proxy").setOnPreferenceChangeListener(this);
+
         updateProxyVpn(!prefs.getBoolean("proxy_mode", false));
+        updateUpstreamProxy(prefs.getBoolean("upstream_proxy", false));
 
         updateSpecDnsStatus(prefs.getString(DNS_PROVIDER, "GOOGLE_DOH"));
         updateVPNModeItem();
@@ -130,6 +133,12 @@ private void updateProxyVpn(boolean vpnMode) {
         updateVPNModeItem(vpnMode);
     }
 
+    private void updateUpstreamProxy(boolean enabled) {
+        findPreference("upstream_ip").setEnabled(enabled);
+        findPreference("upstream_port").setEnabled(enabled);
+        findPreference("upstream_cache").setEnabled(enabled);
+    }
+
     private void updateSpecDnsStatus(String provider) {
         prefSpecDns.setEnabled(provider.equals("SPECIFIED"));
     }
@@ -182,6 +191,7 @@ public boolean onPreferenceClick(Preference preference) {
 
     @Override
     public boolean onPreferenceChange(Preference preference, Object newValue) {
+        System.out.println("CHANGED: " + preference.getKey());
         switch (preference.getKey()) {
             case "theme": {
                 MainActivity.applyTheme(((String) newValue));
@@ -195,6 +205,10 @@ public boolean onPreferenceChange(Preference preference, Object newValue) {
                 updateProxyVpn(vpnMode);
                 break;
             }
+            case "upstream_proxy": {
+                updateUpstreamProxy(((boolean) newValue));
+                break;
+            }
             case "sni": {
                 if(((boolean) newValue) && context != null) {
                     Toast.makeText(context, R.string.sni_warning, Toast.LENGTH_LONG).show();

diff --git a/app/src/main/java/ru/krlvm/powertunnel/android/managers/PTManager.java b/app/src/main/java/ru/krlvm/powertunnel/android/managers/PTManager.java
@@ -56,6 +56,16 @@ public static void configure(Context context, SharedPreferences prefs) {
             PowerTunnel.DEFAULT_CHUNK_SIZE = 2;
         }
         PowerTunnel.PAYLOAD_LENGTH = prefs.getBoolean("send_payload", false) ? 21 : 0;
+        if(prefs.getBoolean("upstream_proxy", false)) {
+            PowerTunnel.UPSTREAM_PROXY_CACHE = prefs.getBoolean("upstream_cache", false);
+            PowerTunnel.UPSTREAM_PROXY_IP = prefs.getString("upstream_ip", null);
+            PowerTunnel.UPSTREAM_PROXY_PORT = Integer.parseInt(prefs.getString("upstream_port", "-1"));
+            PowerTunnel.UPSTREAM_PROXY_USERNAME = prefs.getString("upstream_username", null);
+            PowerTunnel.UPSTREAM_PROXY_PASSWORD = prefs.getString("upstream_password", null);
+        } else {
+            PowerTunnel.UPSTREAM_PROXY_IP = null;
+            PowerTunnel.UPSTREAM_PROXY_USERNAME = null;
+        }
         DNS_SERVERS = Util.getDefaultDNS(context);
         DNS_OVERRIDE = false;
         PowerTunnel.DOH_ADDRESS = null;

diff --git a/app/src/main/res/values-ru/strings.xml b/app/src/main/res/values-ru/strings.xml
@@ -101,4 +101,11 @@
     <string name="read_more">Подробнее</string>
     <string name="failed_to_start_powertunnel">Ошибка при запуске PowerTunnel</string>
     <string name="restarting_proxy">Прокси-сервер перезапускается…</string>
+    <string name="pref_upstream_proxy">Подключаться используя внешний прокси-сервер</string>
+    <string name="pref_upstream_proxy_desc">Подключение к Интернету будет осуществляться через внешний прокси-сервер</string>
+    <string name="pref_upstream_ip">Адрес внешнего прокси-сервера</string>
+    <string name="pref_upstream_port">Порт внешнего прокси-сервера</string>
+    <string name="pref_upstream_title">Внешний прокси-сервер</string>
+    <string name="pref_upstream_cache">Кешировать адрес внешнего прокси-сервера</string>
+    <string name="pref_upstream_cache_desc">Увеличивает производительность</string>
 </resources>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
@@ -117,8 +117,8 @@
     <string name="dns_fetch_error">Failed to fetch the DNS servers list</string>
     <string name="error">Error</string>
     <string name="download">Download</string>
-    <string name="specify_dns_provider">Specify DNS provider</string>
-    <string name="specified_dns_provider">Specified DNS provider</string>
+    <string name="specify_dns_provider">Custom DNS provider</string>
+    <string name="specified_dns_provider">Custom DNS provider</string>
     <string name="pref_theme_title">Dark theme</string>
     <string name="pref_category_appearance">Appearance</string>
     <string name="secdns_discounted">SecureDNS DNS provider has been discounted since April 30, 2020. Your DNS provider was automatically changed to CloudFlare DoH to avoid connectivity issues.</string>
@@ -130,7 +130,7 @@
     <string name="proxy_mode_warning">Now you have to set applications proxy manually. If you have problems, switch back to VPN mode disabling proxy mode.</string>
     <string name="notification_channel_proxy">PowerTunnel Proxy</string>
     <string name="pref_category_vpn">VPN settings</string>
-    <string name="pref_proxy_ip">Local proxy server address</string>
+    <string name="pref_proxy_ip">Local proxy server IP address</string>
     <string name="pref_proxy_port">Local proxy server port</string>
     <string name="reset_connection_settings">Reset proxy settings</string>
     <string name="reset_connection_settings_summary">Return to default address and port</string>
@@ -155,4 +155,11 @@
     <string name="samsung_firmware_bug">Samsung introduced a bug in August 2020 software update that preventing us from starting VPN service, you have can solve this problem manually.</string>
     <string name="read_more">Read more</string>
     <string name="restarting_proxy">Restarting proxy server…</string>
+    <string name="pref_upstream_proxy">Connect via upstream proxy</string>
+    <string name="pref_upstream_proxy_desc">Use upstream proxy to connect to the Internet</string>
+    <string name="pref_upstream_ip">Upstream proxy IP address</string>
+    <string name="pref_upstream_port">Upstream proxy port</string>
+    <string name="pref_upstream_title">Upstream proxy</string>
+    <string name="pref_upstream_cache">Cache upstream proxy address</string>
+    <string name="pref_upstream_cache_desc">Improves performance</string>
 </resources>
diff --git a/app/src/main/res/xml/preferences.xml b/app/src/main/res/xml/preferences.xml
@@ -46,6 +46,36 @@
 			android:defaultValue="false"/>
 	</PreferenceCategory>
 
+	<PreferenceCategory android:title="@string/pref_upstream_title">
+		<SwitchPreference
+			android:title="@string/pref_upstream_proxy"
+			android:summary="@string/pref_upstream_proxy_desc"
+			android:key="upstream_proxy"
+			android:defaultValue="false"/>
+
+		<tun.proxy.preferences.preference.EditTextSummaryPreference
+			android:key="upstream_ip"
+			android:title="@string/pref_upstream_ip"
+			android:defaultValue=""
+			android:summary="%s"
+			app:useSimpleSummaryProvider="true" />
+
+		<tun.proxy.preferences.preference.EditTextSummaryPreference
+			android:key="upstream_port"
+			android:title="@string/pref_upstream_port"
+			android:defaultValue=""
+			android:summary="%s"
+			android:inputType="numberDecimal"
+			android:maxLength="4"
+			app:useSimpleSummaryProvider="true" />
+
+		<SwitchPreference
+			android:title="@string/pref_upstream_cache"
+			android:summary="@string/pref_upstream_cache_desc"
+			android:key="upstream_cache"
+			android:defaultValue="false"/>
+	</PreferenceCategory>
+
 	<PreferenceCategory android:title="@string/pref_category_vpn">
 		<ListPreference
 			android:key="vpn_connection_mode"