SOCKS5 proxy, implement #100

src/main/kotlin/com/github/creeper123123321/viaaas/config/VIAaaSConfig.kt

@@ -40,4 +40,7 @@ object VIAaaSConfig : Config(File("config/viaaas.yml")) {
     val rateLimitWs: Double get() = this.getDouble("rate-limit-ws", 1.0)
     val rateLimitConnectionMc: Double get() = this.getDouble("rate-limit-connection-mc", 10.0)
     val listeningWsLimit: Int get() = this.getInt("listening-ws-limit", 16)
+    val backendSocks5ProxyAddress: String?
+        get() = this.getString("backend-socks5-proxy-address", "")!!.let { if (it.isEmpty()) null else it }
+    val backendSocks5ProxyPort: Int get() = this.getInt("backend-socks5-proxy-port", 9050)
 }

src/main/kotlin/com/github/creeper123123321/viaaas/handler/BackEndInit.kt

@@ -14,7 +14,7 @@ class BackEndInit(val connectionData: ConnectionData) : ChannelInitializer<Chann
     override fun initChannel(ch: Channel) {
         val user = UserConnection(ch, true)
         ProtocolPipeline(user)
-        ch.pipeline()
+        ch.pipeline().also { addSocks5(it) }
             // "crypto"
             .addLast("frame", FrameCodec())
             // compress

src/main/kotlin/com/github/creeper123123321/viaaas/handler/Util.kt

@@ -1,11 +1,22 @@
 package com.github.creeper123123321.viaaas.handler
 
+import com.github.creeper123123321.viaaas.config.VIAaaSConfig
 import com.github.creeper123123321.viaaas.packet.Packet
 import com.github.creeper123123321.viaaas.send
+import io.netty.channel.ChannelPipeline
+import io.netty.handler.proxy.Socks5ProxyHandler
 import us.myles.ViaVersion.api.protocol.ProtocolVersion
+import java.net.InetSocketAddress
 
 fun forward(handler: MinecraftHandler, packet: Packet, flush: Boolean = false) {
     send(handler.other!!, packet, flush)
 }
 
 fun is1_7(handler: MinecraftHandler) = handler.data.frontVer!! <= ProtocolVersion.v1_7_6.version
+
+fun addSocks5(pipe: ChannelPipeline) {
+    val addr = VIAaaSConfig.backendSocks5ProxyAddress
+    if (addr != null) {
+        pipe.addFirst(Socks5ProxyHandler(InetSocketAddress(addr, VIAaaSConfig.backendSocks5ProxyPort)))
+    }
+}

src/main/kotlin/com/github/creeper123123321/viaaas/handler/autoprotocol/ProtocolDetector.kt

@@ -6,23 +6,26 @@ import com.github.creeper123123321.viaaas.codec.FrameCodec
 import com.github.creeper123123321.viaaas.codec.MinecraftCodec
 import com.github.creeper123123321.viaaas.handler.ConnectionData
 import com.github.creeper123123321.viaaas.handler.MinecraftHandler
-import com.github.creeper123123321.viaaas.packet.handshake.Handshake
+import com.github.creeper123123321.viaaas.handler.addSocks5
 import com.github.creeper123123321.viaaas.mcLogger
+import com.github.creeper123123321.viaaas.packet.handshake.Handshake
 import com.github.creeper123123321.viaaas.packet.status.StatusRequest
 import com.github.creeper123123321.viaaas.send
-import java.util.concurrent.CompletableFuture
-import java.net.InetSocketAddress
-import us.myles.ViaVersion.api.protocol.ProtocolVersion
-import io.netty.handler.timeout.ReadTimeoutHandler
-import io.netty.channel.socket.nio.NioSocketChannel
-import com.google.common.cache.CacheLoader
-import java.util.concurrent.TimeUnit
 import com.google.common.cache.CacheBuilder
+import com.google.common.cache.CacheLoader
 import io.netty.bootstrap.Bootstrap
-import io.netty.channel.*
+import io.netty.channel.Channel
+import io.netty.channel.ChannelFuture
+import io.netty.channel.ChannelInitializer
+import io.netty.channel.ChannelOption
+import io.netty.handler.timeout.ReadTimeoutHandler
 import io.netty.util.concurrent.Future
+import us.myles.ViaVersion.api.protocol.ProtocolVersion
 import us.myles.ViaVersion.packets.State
+import java.net.InetSocketAddress
+import java.util.concurrent.CompletableFuture
 import java.util.concurrent.ExecutionException
+import java.util.concurrent.TimeUnit
 
 object ProtocolDetector {
     private val SERVER_VER = CacheBuilder.newBuilder()
@@ -38,7 +41,7 @@ object ProtocolDetector {
                     .handler(object : ChannelInitializer<Channel>() {
                         override fun initChannel(channel: Channel) {
                             val data = ConnectionData(channel, state = ProtocolDetectionState(future), frontVer = -1)
-                            channel.pipeline()
+                            channel.pipeline().also { addSocks5(it) }
                                 .addLast("timeout", ReadTimeoutHandler(30, TimeUnit.SECONDS))
                                 .addLast("frame", FrameCodec())
                                 .addLast("mc", MinecraftCodec())

src/main/resources/viaaas.yml

@@ -12,6 +12,10 @@ port: 25565
 bind-address: localhost
 # Use Netty native transport for Minecraft connections when available.
 native-transport-mc: true
+# Address of SOCKS5 proxy used for connecting to backend servers. Empty to disable.
+backend-socks5-proxy-address: ""
+# Port of SOCKS5 proxy used for connecting to backend servers.
+backend-socks5-proxy-port: 9050
 #
 ######
 # Crypto