Add cross-domain policy support

Required by the most recent versions of the Java plugin (before it was
killed).

Signed-off-by: Graham <gpe@openrs2.org>

game/src/main/kotlin/org/openrs2/game/net/crossdomain/CrossDomainChannelHandler.kt

@@ -0,0 +1,46 @@
+package org.openrs2.game.net.crossdomain
+
+import io.netty.buffer.Unpooled
+import io.netty.channel.ChannelFutureListener
+import io.netty.channel.ChannelHandler
+import io.netty.channel.ChannelHandlerContext
+import io.netty.channel.SimpleChannelInboundHandler
+import io.netty.handler.codec.http.HttpHeaderNames
+import io.netty.handler.codec.http.HttpMethod
+import io.netty.handler.codec.http.HttpRequest
+import io.netty.handler.codec.http.HttpResponseStatus
+import org.openrs2.game.net.http.Http
+
+@ChannelHandler.Sharable
+public object CrossDomainChannelHandler : SimpleChannelInboundHandler<HttpRequest>() {
+    private const val ENDPOINT = "/crossdomain.xml"
+    private val POLICY = """
+        <?xml version="1.0"?>
+        <!DOCTYPE cross-domain-policy SYSTEM "http://www.adobe.com/xml/dtds/cross-domain-policy.dtd">
+        <cross-domain-policy>
+            <site-control permitted-cross-domain-policies="master-only" />
+            <allow-access-from domain="*" />
+        </cross-domain-policy>
+    """.trimIndent().plus("\n").toByteArray(Charsets.UTF_8)
+
+    override fun handlerAdded(ctx: ChannelHandlerContext) {
+        ctx.read()
+    }
+
+    override fun channelRead0(ctx: ChannelHandlerContext, msg: HttpRequest) {
+        if (msg.method() != HttpMethod.GET || msg.uri() != ENDPOINT) {
+            ctx.write(Http.createResponse(HttpResponseStatus.BAD_REQUEST)).addListener(ChannelFutureListener.CLOSE)
+            return
+        }
+
+        val response = Http.createResponse(HttpResponseStatus.OK)
+        response.headers().add(HttpHeaderNames.CONTENT_TYPE, Http.TEXT_X_CROSS_DOMAIN_POLICY)
+        response.headers().add(HttpHeaderNames.CONTENT_LENGTH, POLICY.size)
+        ctx.write(response, ctx.voidPromise())
+        ctx.write(Unpooled.wrappedBuffer(POLICY)).addListener(ChannelFutureListener.CLOSE)
+    }
+
+    override fun channelReadComplete(ctx: ChannelHandlerContext) {
+        ctx.flush()
+    }
+}

game/src/main/kotlin/org/openrs2/game/net/http/Http.kt

@@ -0,0 +1,20 @@
+package org.openrs2.game.net.http
+
+import io.netty.handler.codec.http.DefaultHttpResponse
+import io.netty.handler.codec.http.HttpHeaderNames
+import io.netty.handler.codec.http.HttpHeaderValues
+import io.netty.handler.codec.http.HttpResponse
+import io.netty.handler.codec.http.HttpResponseStatus
+import io.netty.handler.codec.http.HttpVersion
+
+public object Http {
+    public const val MAX_CONTENT_LENGTH: Int = 65536
+    public const val TEXT_X_CROSS_DOMAIN_POLICY: String = "text/x-cross-domain-policy"
+
+    public fun createResponse(status: HttpResponseStatus): HttpResponse {
+        val response = DefaultHttpResponse(HttpVersion.HTTP_1_1, status)
+        response.headers().add(HttpHeaderNames.CONNECTION, HttpHeaderValues.CLOSE)
+        response.headers().add(HttpHeaderNames.SERVER, "OpenRS2")
+        return response
+    }
+}

game/src/main/kotlin/org/openrs2/game/net/http/HttpChannelHandler.kt

@@ -4,13 +4,10 @@ import io.netty.channel.ChannelFutureListener
 import io.netty.channel.ChannelHandler
 import io.netty.channel.ChannelHandlerContext
 import io.netty.channel.SimpleChannelInboundHandler
-import io.netty.handler.codec.http.DefaultHttpResponse
 import io.netty.handler.codec.http.HttpHeaderNames
 import io.netty.handler.codec.http.HttpHeaderValues
 import io.netty.handler.codec.http.HttpRequest
-import io.netty.handler.codec.http.HttpResponse
 import io.netty.handler.codec.http.HttpResponseStatus
-import io.netty.handler.codec.http.HttpVersion
 import org.openrs2.game.net.FileProvider
 import javax.inject.Inject
 import javax.inject.Singleton
@@ -27,17 +24,17 @@ public class HttpChannelHandler @Inject constructor(
     override fun channelRead0(ctx: ChannelHandlerContext, msg: HttpRequest) {
         val uri = msg.uri()
         if (!uri.startsWith("/")) {
-            ctx.write(createResponse(HttpResponseStatus.BAD_REQUEST)).addListener(ChannelFutureListener.CLOSE)
+            ctx.write(Http.createResponse(HttpResponseStatus.BAD_REQUEST)).addListener(ChannelFutureListener.CLOSE)
             return
         }
 
         val file = fileProvider.get(uri.substring(1))
         if (file == null) {
-            ctx.write(createResponse(HttpResponseStatus.NOT_FOUND)).addListener(ChannelFutureListener.CLOSE)
+            ctx.write(Http.createResponse(HttpResponseStatus.NOT_FOUND)).addListener(ChannelFutureListener.CLOSE)
             return
         }
 
-        val response = createResponse(HttpResponseStatus.OK)
+        val response = Http.createResponse(HttpResponseStatus.OK)
         response.headers().add(HttpHeaderNames.CONTENT_TYPE, HttpHeaderValues.APPLICATION_OCTET_STREAM)
         response.headers().add(HttpHeaderNames.CONTENT_LENGTH, file.count())
 
@@ -48,11 +45,4 @@ public class HttpChannelHandler @Inject constructor(
     override fun channelReadComplete(ctx: ChannelHandlerContext) {
         ctx.flush()
     }
-
-    private fun createResponse(status: HttpResponseStatus): HttpResponse {
-        val response = DefaultHttpResponse(HttpVersion.HTTP_1_1, status)
-        response.headers().add(HttpHeaderNames.CONNECTION, HttpHeaderValues.CLOSE)
-        response.headers().add(HttpHeaderNames.SERVER, "OpenRS2")
-        return response
-    }
 }

game/src/main/kotlin/org/openrs2/game/net/http/HttpChannelInitializer.kt

@@ -16,12 +16,8 @@ public class HttpChannelInitializer @Inject constructor(
         ch.pipeline().addLast(
             HttpRequestDecoder(),
             HttpResponseEncoder(),
-            HttpObjectAggregator(MAX_CONTENT_LENGTH),
+            HttpObjectAggregator(Http.MAX_CONTENT_LENGTH),
             handler
         )
     }
-
-    private companion object {
-        private const val MAX_CONTENT_LENGTH = 65536
-    }
 }

game/src/main/kotlin/org/openrs2/game/net/login/LoginChannelHandler.kt

@@ -5,8 +5,13 @@ import io.netty.channel.ChannelFutureListener
 import io.netty.channel.ChannelHandlerContext
 import io.netty.channel.SimpleChannelInboundHandler
 import io.netty.handler.codec.DelimiterBasedFrameDecoder
+import io.netty.handler.codec.http.HttpObjectAggregator
+import io.netty.handler.codec.http.HttpRequestDecoder
+import io.netty.handler.codec.http.HttpResponseEncoder
 import io.netty.handler.codec.string.StringDecoder
 import org.openrs2.buffer.copiedBuffer
+import org.openrs2.game.net.crossdomain.CrossDomainChannelHandler
+import org.openrs2.game.net.http.Http
 import org.openrs2.game.net.jaggrab.JaggrabChannelHandler
 import org.openrs2.game.net.js5.Js5ChannelHandler
 import org.openrs2.protocol.Rs2Decoder
@@ -32,6 +37,7 @@ public class LoginChannelHandler @Inject constructor(
         when (msg) {
             is LoginRequest.InitJs5RemoteConnection -> handleInitJs5RemoteConnection(ctx, msg)
             is LoginRequest.InitJaggrabConnection -> handleInitJaggrabConnection(ctx)
+            is LoginRequest.InitCrossDomainConnection -> handleInitCrossDomainConnection(ctx)
         }
     }
 
@@ -67,6 +73,21 @@ public class LoginChannelHandler @Inject constructor(
         ctx.pipeline().remove(this)
     }
 
+    private fun handleInitCrossDomainConnection(ctx: ChannelHandlerContext) {
+        ctx.pipeline().addLast(
+            HttpRequestDecoder(),
+            HttpResponseEncoder(),
+            HttpObjectAggregator(Http.MAX_CONTENT_LENGTH),
+            CrossDomainChannelHandler
+        )
+
+        ctx.fireChannelRead(Unpooled.wrappedBuffer(G))
+
+        ctx.pipeline().remove(Rs2Decoder::class.java)
+        ctx.pipeline().remove(Rs2Encoder::class.java)
+        ctx.pipeline().remove(this)
+    }
+
     override fun channelReadComplete(ctx: ChannelHandlerContext) {
         ctx.flush()
     }
@@ -75,5 +96,6 @@ public class LoginChannelHandler @Inject constructor(
         private const val BUILD = 550
         private const val JAGGRAB_MAX_FRAME_LENGTH = 4096
         private val JAGGRAB_DELIMITER = Unpooled.unreleasableBuffer(copiedBuffer("\n\n"))
+        private val G = byteArrayOf('G'.code.toByte())
     }
 }

protocol/src/main/kotlin/org/openrs2/protocol/Protocol.kt

@@ -1,6 +1,7 @@
 package org.openrs2.protocol
 
 import org.openrs2.protocol.login.ClientOutOfDateCodec
+import org.openrs2.protocol.login.InitCrossDomainConnectionCodec
 import org.openrs2.protocol.login.InitJaggrabConnectionCodec
 import org.openrs2.protocol.login.InitJs5RemoteConnectionCodec
 import org.openrs2.protocol.login.IpLimitCodec
@@ -32,7 +33,8 @@ public class Protocol(vararg codecs: PacketCodec<*>) {
         public val LOGIN_UPSTREAM: Protocol = Protocol(
             InitJs5RemoteConnectionCodec,
             InitJaggrabConnectionCodec,
-            RequestWorldListCodec
+            RequestWorldListCodec,
+            InitCrossDomainConnectionCodec
         )
         public val LOGIN_DOWNSTREAM: Protocol = Protocol(
             Js5OkCodec,

protocol/src/main/kotlin/org/openrs2/protocol/login/InitCrossDomainConnectionCodec.kt

@@ -0,0 +1,8 @@
+package org.openrs2.protocol.login
+
+import org.openrs2.protocol.EmptyPacketCodec
+
+public object InitCrossDomainConnectionCodec : EmptyPacketCodec<LoginRequest.InitCrossDomainConnection>(
+    opcode = 'G'.code,
+    packet = LoginRequest.InitCrossDomainConnection
+)

protocol/src/main/kotlin/org/openrs2/protocol/login/LoginRequest.kt

@@ -6,4 +6,5 @@ public sealed class LoginRequest : Packet {
     public data class InitJs5RemoteConnection(public val build: Int) : LoginRequest()
     public object InitJaggrabConnection : LoginRequest()
     public data class RequestWorldList(public val checksum: Int) : LoginRequest()
+    public object InitCrossDomainConnection : LoginRequest()
 }