feat: bypass internet censorship

android/app/src/main/java/com/rajarsheechatterjee/NativeNetwork/LocalAddressClassifier.kt

@@ -0,0 +1,63 @@
+package com.rajarsheechatterjee.NativeNetwork
+
+import java.net.Inet6Address
+import java.net.InetAddress
+
+internal object LocalAddressClassifier {
+    private val localDnsSuffixes = listOf(
+        ".localhost",
+        ".local",
+        ".lan",
+        ".home",
+        ".home.arpa",
+        ".internal",
+    )
+
+    fun isLocalHostname(value: String): Boolean {
+        val host = value.trim().trimEnd('.').lowercase()
+        return host == "localhost" ||
+            host.isNotEmpty() && '.' !in host && ':' !in host ||
+            localDnsSuffixes.any(host::endsWith)
+    }
+
+    fun isIpLiteral(value: String): Boolean {
+        val host = value.trim().removePrefix("[").removeSuffix("]")
+        return ':' in host || host.isIpv4Address()
+    }
+
+    fun isLocalAddress(address: InetAddress): Boolean {
+        if (address.isAnyLocalAddress ||
+            address.isLoopbackAddress ||
+            address.isLinkLocalAddress ||
+            address.isSiteLocalAddress
+        ) {
+            return true
+        }
+
+        val bytes = address.address
+        if (address is Inet6Address) {
+            return bytes.isNotEmpty() && (bytes[0].toInt() and 0xFE) == 0xFC
+        }
+        if (bytes.size != 4) return false
+
+        val first = bytes[0].toInt() and 0xFF
+        val second = bytes[1].toInt() and 0xFF
+        return first == 0 ||
+            first == 10 ||
+            first == 127 ||
+            first == 169 && second == 254 ||
+            first == 172 && second in 16..31 ||
+            first == 192 && second == 168 ||
+            first == 100 && second in 64..127
+    }
+
+    private fun String.isIpv4Address(): Boolean {
+        val octets = split('.')
+        return octets.size == 4 && octets.all { octet ->
+            octet.isNotEmpty() &&
+                octet.length <= 3 &&
+                octet.all { it in '0'..'9' } &&
+                octet.toInt() in 0..255
+        }
+    }
+}

android/app/src/main/java/com/rajarsheechatterjee/NativeNetwork/LocalAwareDns.kt

@@ -8,37 +8,11 @@ internal class LocalAwareDns(
     private val delegate: Dns,
 ) : Dns {
     override fun lookup(hostname: String): List<InetAddress> =
-        if (hostname.isLocalHost()) {
+        if (LocalAddressClassifier.isLocalHostname(hostname) ||
+            LocalAddressClassifier.isIpLiteral(hostname)
+        ) {
             Dns.SYSTEM.lookup(hostname)
         } else {
             delegate.lookup(hostname)
         }
 }
-
-private fun String.isLocalHost(): Boolean {
-    val host = trimEnd('.').lowercase()
-    return host == "localhost" ||
-        '.' !in host ||
-        ':' in host ||
-        host.isIpv4Address() ||
-        LOCAL_DNS_SUFFIXES.any(host::endsWith)
-}
-
-private fun String.isIpv4Address(): Boolean {
-    val octets = split('.')
-    return octets.size == 4 && octets.all { octet ->
-        octet.isNotEmpty() &&
-            octet.length <= 3 &&
-            octet.all { it in '0'..'9' } &&
-            octet.toInt() in 0..255
-    }
-}
-
-private val LOCAL_DNS_SUFFIXES = listOf(
-    ".localhost",
-    ".local",
-    ".lan",
-    ".home",
-    ".home.arpa",
-    ".internal",
-)

android/app/src/main/java/com/rajarsheechatterjee/NativeNetwork/NativeNetworkModule.kt

@@ -7,22 +7,40 @@ import android.webkit.WebView
 import com.facebook.react.bridge.Promise
 import com.facebook.react.bridge.ReactApplicationContext
 import com.facebook.react.bridge.UiThreadUtil
+import com.facebook.react.modules.network.OkHttpClientProvider
 import com.lnreader.spec.NativeNetworkSpec
 import java.io.File
 import okhttp3.Headers
 
 class NativeNetworkModule(context: ReactApplicationContext) : NativeNetworkSpec(context) {
+    private val networkPreferences = reactApplicationContext.getSharedPreferences(
+        NETWORK_PREFERENCES,
+        Context.MODE_PRIVATE,
+    )
+
     override fun setDohProvider(providerId: String) {
         require(DohProvider.isSupported(providerId)) {
             "Unsupported DNS-over-HTTPS provider: $providerId"
         }
-        reactApplicationContext
-            .getSharedPreferences(NETWORK_PREFERENCES, Context.MODE_PRIVATE)
-            .edit()
+        networkPreferences.edit()
             .putString(DOH_PROVIDER_KEY, providerId)
             .apply()
     }
 
+    override fun setNetworkMode(mode: String) {
+        require(NetworkMode.isSupported(mode)) { "Unsupported network mode: $mode" }
+        networkPreferences.edit()
+            .putString(NETWORK_MODE_KEY, mode)
+            .apply()
+        refreshRouting()
+    }
+
+    override fun getNetworkMode(): String = readNetworkMode(reactApplicationContext).id
+
+    private fun refreshRouting() {
+        OkHttpClientProvider.getOkHttpClient().connectionPool.evictAll()
+    }
+
     override fun isUserAgentValid(value: String): Boolean {
         if (value.isBlank()) return false
         return runCatching {

android/app/src/main/java/com/rajarsheechatterjee/NativeNetwork/NetworkClientFactory.kt

@@ -4,6 +4,7 @@ import android.content.Context
 import com.facebook.react.modules.network.OkHttpClientFactory
 import com.facebook.react.modules.network.OkHttpClientProvider
 import java.io.File
+import java.net.Proxy
 import okhttp3.Cache
 import okhttp3.OkHttpClient
 
@@ -23,14 +24,24 @@ class NetworkClientFactory(context: Context) : OkHttpClientFactory {
         val baseClient = OkHttpClientProvider.createClientBuilder()
             .cache(cache)
             .build()
-        val providerId = applicationContext
-            .getSharedPreferences(NETWORK_PREFERENCES, Context.MODE_PRIVATE)
+        val preferences = applicationContext.getSharedPreferences(
+            NETWORK_PREFERENCES,
+            Context.MODE_PRIVATE,
+        )
+        val providerId = preferences
             .getString(DOH_PROVIDER_KEY, DISABLED_DOH_PROVIDER)
             .orEmpty()
-        val provider = DohProvider.fromId(providerId) ?: return baseClient
+        val provider = DohProvider.fromId(providerId)
+        val clientBuilder = baseClient.newBuilder()
+            .socketFactory(RoutingSocketFactory(applicationContext))
 
-        return baseClient.newBuilder()
-            .dns(provider.createDns(baseClient))
-            .build()
+        if (provider != null) {
+            val bootstrapClient = baseClient.newBuilder()
+                .proxy(Proxy.NO_PROXY)
+                .build()
+            clientBuilder.dns(provider.createDns(bootstrapClient))
+        }
+
+        return clientBuilder.build()
     }
 }

android/app/src/main/java/com/rajarsheechatterjee/NativeNetwork/NetworkMode.kt

@@ -0,0 +1,20 @@
+package com.rajarsheechatterjee.NativeNetwork
+
+import android.content.Context
+
+internal const val NETWORK_MODE_KEY = "network_mode"
+
+internal enum class NetworkMode(val id: String) {
+    DIRECT("direct"),
+    DPI_BYPASS("dpi_bypass");
+
+    companion object {
+        fun fromId(id: String?) = entries.find { it.id == id } ?: DIRECT
+        fun isSupported(id: String) = entries.any { it.id == id }
+    }
+}
+
+internal fun readNetworkMode(context: Context): NetworkMode = NetworkMode.fromId(
+    context.getSharedPreferences(NETWORK_PREFERENCES, Context.MODE_PRIVATE)
+        .getString(NETWORK_MODE_KEY, null),
+)

specs/NativeNetwork.ts

@@ -3,6 +3,8 @@ import { TurboModuleRegistry } from 'react-native';
 
 export interface Spec extends TurboModule {
   setDohProvider(providerId: string): void;
+  setNetworkMode(mode: string): void;
+  getNetworkMode(): string;
   isUserAgentValid(value: string): boolean;
   clearWebViewData(): Promise<void>;
 }

src/screens/settings/SettingsAdvancedScreen.tsx

@@ -16,13 +16,15 @@ import { NOVEL_UPDATE_RANDOM_KEY } from '@hooks/persisted/useUpdates';
 import { AdvancedSettingsScreenProps } from '@navigators/types';
 import { store } from '@plugins/helpers/storage';
 import CookieManager from '@preeternal/react-native-cookie-manager';
+import { useFocusEffect } from '@react-navigation/native';
 import { getDohProviderName } from '@services/network/doh';
+import { getNetworkMode, setNetworkMode } from '@services/network/settings';
 import NativeLocalServer from '@specs/NativeLocalServer';
 import NativeNetwork from '@specs/NativeNetwork';
 import { getString } from '@strings/translations';
 import { MMKVStorage } from '@utils/mmkv/mmkv';
 import { showToast } from '@utils/showToast';
-import React, { useState } from 'react';
+import React, { useCallback, useState } from 'react';
 import { ScrollView, StyleSheet, View } from 'react-native';
 import { KeyboardAwareScrollView } from 'react-native-keyboard-controller';
 import { Portal, Text, TextInput } from 'react-native-paper';
@@ -37,6 +39,13 @@ const AdvancedSettings = ({ navigation }: AdvancedSettingsScreenProps) => {
   const appSettings = useAppSettings();
   const { verboseLogging, setAppSettings } = appSettings;
   const [userAgentInput, setUserAgentInput] = useState(userAgent);
+  const [networkMode, setCurrentNetworkMode] = useState(getNetworkMode);
+
+  useFocusEffect(
+    useCallback(() => {
+      setCurrentNetworkMode(getNetworkMode());
+    }, []),
+  );
 
   /**
    * Confirm Clear Database Dialog
@@ -201,6 +210,18 @@ const AdvancedSettings = ({ navigation }: AdvancedSettingsScreenProps) => {
             onPress={showDohProviderModal}
             theme={theme}
           />
+          <SettingSwitch
+            label={getString('advancedSettingsScreen.bypassDpi')}
+            description={getString('advancedSettingsScreen.bypassDpiDesc')}
+            value={networkMode === 'dpi_bypass'}
+            onPress={() => {
+              const mode =
+                networkMode === 'dpi_bypass' ? 'direct' : 'dpi_bypass';
+              setNetworkMode(mode);
+              setCurrentNetworkMode(mode);
+            }}
+            theme={theme}
+          />
           <List.Item
             title={getString('advancedSettingsScreen.userAgent')}
             description={userAgent}

src/services/network/settings.ts

@@ -0,0 +1,10 @@
+import NativeNetwork from '@specs/NativeNetwork';
+
+export type NetworkMode = 'direct' | 'dpi_bypass';
+
+export const getNetworkMode = (): NetworkMode =>
+  NativeNetwork.getNetworkMode() === 'dpi_bypass' ? 'dpi_bypass' : 'direct';
+
+export const setNetworkMode = (mode: NetworkMode) => {
+  NativeNetwork.setNetworkMode(mode);
+};

strings/languages/en/strings.json

@@ -46,6 +46,8 @@
     "webViewDataClearFailed": "Failed to clear WebView data",
     "dnsOverHttps": "DNS over HTTPS (DoH)",
     "disabled": "Disabled",
+    "bypassDpi": "Bypass internet censorship",
+    "bypassDpiDesc": "(Experimental) Split initial HTTP and TLS traffic to bypass DPI filtering.",
     "resetUserAgent": "Reset default User Agent",
     "invalidUserAgent": "Invalid User-Agent value",
     "storageUsage": "Storage usage",
@@ -66,11 +68,11 @@
     "recreateDBIndexesDesc": "Recreates DB indexes. This may improve performance on slower devices.",
     "developer": "Developer",
     "allowCloudflareBypass": "Allow plugins to use Cloudflare bypass API",
-    "allowCloudflareBypassDesc": "Enables the Cloudflare Turnstile bypass API for plugins. Requires app restart.",
+    "allowCloudflareBypassDesc": "Enables the Cloudflare Turnstile bypass API for plugins.",
     "hideCloudflareOverlay": "Hide WebView overlay when bypassing CF",
     "hideCloudflareOverlayDesc": "Hides the Cloudflare WebView while bypassing. Uncheck to see the solving process.",
     "allowProxyAPI": "Allow plugins to use Proxy API",
-    "allowProxyAPIDesc": "Enables the LocalHttpServer Proxy API used by plugins to bypass CORS. Takes effect immediately.",
+    "allowProxyAPIDesc": "Enables the LocalHttpServer Proxy API used by plugins to bypass CORS.",
     "verboseLogging": "Verbose Logging",
     "verboseLoggingDesc": "Print detailed logs including system logs (reduces performance)",
     "restartRequiredToast": "Please restart the app to apply changes"

strings/languages/vi_VN/strings.json

@@ -46,6 +46,8 @@
     "webViewDataClearFailed": "Không thể xóa dữ liệu WebView",
     "dnsOverHttps": "DNS qua HTTPS (DoH)",
     "disabled": "Đã tắt",
+    "bypassDpi": "Vượt kiểm duyệt Internet",
+    "bypassDpiDesc": "(Thử nghiệm) Chia nhỏ lưu lượng HTTP và TLS ban đầu để vượt bộ lọc DPI.",
     "resetUserAgent": "Đặt lại User Agent mặc định",
     "invalidUserAgent": "Giá trị User-Agent không hợp lệ",
     "storageUsage": "Kho chứa chiếm dụng",
@@ -66,11 +68,11 @@
     "recreateDBIndexesDesc": "Tạo lại DB indexes. Việc này có thể cải thiện hiệu năng trên các thiết bị chậm hơn.",
     "developer": "Nhà phát triển",
     "allowCloudflareBypass": "Cho phép plugin sử dụng API bypass Cloudflare",
-    "allowCloudflareBypassDesc": "Bật tính năng vượt qua Cloudflare Turnstile cho các plugin. Yêu cầu khởi động lại ứng dụng.",
+    "allowCloudflareBypassDesc": "Bật tính năng vượt qua Cloudflare Turnstile cho các plugin.",
     "hideCloudflareOverlay": "Ẩn overlay WebView khi bypass CF",
     "hideCloudflareOverlayDesc": "Ẩn giao diện giải Cloudflare. Tắt đi nếu bạn muốn xem quá trình giải.",
     "allowProxyAPI": "Cho phép plugin sử dụng Proxy API",
-    "allowProxyAPIDesc": "Bật tính năng Proxy API cho LocalHttpServer để giúp plugin vượt qua CORS. Áp dụng ngay lập tức.",
+    "allowProxyAPIDesc": "Bật tính năng Proxy API cho LocalHttpServer để giúp plugin vượt qua CORS.",
     "verboseLogging": "Ghi nhật ký chi tiết",
     "verboseLoggingDesc": "In các ghi chép tường tận đến cả hệ thống (giảm hiệu suất)",
     "restartRequiredToast": "Vui lòng khởi động lại ứng dụng để áp dụng thay đổi"

strings/types/index.ts

@@ -47,6 +47,8 @@ export interface StringMap {
   'advancedSettingsScreen.webViewDataClearFailed': 'string';
   'advancedSettingsScreen.dnsOverHttps': 'string';
   'advancedSettingsScreen.disabled': 'string';
+  'advancedSettingsScreen.bypassDpi': 'string';
+  'advancedSettingsScreen.bypassDpiDesc': 'string';
   'advancedSettingsScreen.resetUserAgent': 'string';
   'advancedSettingsScreen.invalidUserAgent': 'string';
   'advancedSettingsScreen.storageUsage': 'string';