mkurz commented on code in PR #1114: URL: https://github.com/apache/pekko-http/pull/1114#discussion_r3639597551
########## http-core/src/main/scala/org/apache/pekko/http/impl/engine/ws/PerMessageDeflate.scala: ########## @@ -0,0 +1,345 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * https://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.pekko.http.impl.engine.ws + +import java.io.ByteArrayOutputStream +import java.util.Random +import java.util.zip.Deflater +import java.util.zip.Inflater +import java.util.zip.DataFormatException + +import org.apache.pekko +import pekko.NotUsed +import pekko.annotation.InternalApi +import pekko.http.impl.settings.WebSocketCompressionSettingsImpl +import pekko.http.scaladsl.model.headers.WebSocketExtension +import pekko.stream.scaladsl.BidiFlow +import pekko.stream.scaladsl.Flow +import pekko.stream.stage.GraphStage +import pekko.stream.stage.GraphStageLogic +import pekko.stream.stage.InHandler +import pekko.stream.stage.OutHandler +import pekko.stream.{ Attributes, FlowShape, Inlet, Outlet } +import pekko.util.ByteString + +import scala.collection.immutable +import scala.collection.immutable.ListMap + +/** + * INTERNAL API + */ +@InternalApi +private[http] object PerMessageDeflate { + private val ExtensionName = "permessage-deflate" + private val ClientMaxWindowBits = "client_max_window_bits" + private val ServerMaxWindowBits = "server_max_window_bits" + private val ClientNoContextTakeover = "client_no_context_takeover" + private val ServerNoContextTakeover = "server_no_context_takeover" + private val EmptyStoredBlock = ByteString(0x00, 0x00, 0xFF.toByte, 0xFF.toByte) + + final case class Negotiated( + responseExtension: WebSocketExtension, + serverNoContextTakeover: Boolean, + clientNoContextTakeover: Boolean, + settings: WebSocketCompressionSettingsImpl) { + def bidiFlow: BidiFlow[FrameEventOrError, FrameEventOrError, FrameEvent, FrameEvent, NotUsed] = + BidiFlow.fromFlows(inflaterFlow, deflaterFlow) + + def frameEventBidiFlow( + maskRandom: () => Random): BidiFlow[FrameEvent, FrameEvent, FrameEvent, FrameEvent, NotUsed] = + BidiFlow.fromFlows( + Flow[FrameEvent] + .via(Masking.unmaskIf(condition = true)) + .via(inflaterFlow) + .map { + case frame: FrameEvent => frame + case FrameError(ex) => throw ex + } + .via(Masking.maskIf(condition = true, maskRandom)), + deflaterFlow) + + private def inflaterFlow: Flow[FrameEventOrError, FrameEventOrError, NotUsed] = + Flow.fromGraph(new LifecycleMapConcatStage( + "PerMessageDeflate.inflater", + () => new InflaterFlow(clientNoContextTakeover, settings))) + + private def deflaterFlow: Flow[FrameEvent, FrameEvent, NotUsed] = + Flow.fromGraph(new LifecycleMapConcatStage( + "PerMessageDeflate.deflater", + () => new DeflaterFlow(serverNoContextTakeover, settings))) + } + + def negotiate( + requested: immutable.Seq[WebSocketExtension], + settings: WebSocketCompressionSettingsImpl): Option[Negotiated] = { + if (!settings.enabled) None + else { + requested.collectFirst(Function.unlift { extension => + if (extension.name.equalsIgnoreCase(ExtensionName)) negotiate(extension, settings) else None + }) + } + } + + private def negotiate( + extension: WebSocketExtension, + settings: WebSocketCompressionSettingsImpl): Option[Negotiated] = { + var responseParams = ListMap.empty[String, String] + var clientNoContext = false + var serverNoContext = false + var accepted = true + + extension.params.foreach { + case (ClientMaxWindowBits, value) => + if (value.isEmpty) responseParams += ClientMaxWindowBits -> settings.preferredClientWindowSize.toString + else if (validWindowBits(value)) responseParams += ClientMaxWindowBits -> value + else accepted = false + case (ServerMaxWindowBits, value) => + if (value == "15") responseParams += ServerMaxWindowBits -> value + else accepted = false + case (ClientNoContextTakeover, "") => + clientNoContext = settings.preferredClientNoContext + if (clientNoContext) responseParams += ClientNoContextTakeover -> "" + case (ServerNoContextTakeover, "") => + if (settings.allowServerNoContext) { + serverNoContext = true + responseParams += ServerNoContextTakeover -> "" + } else accepted = false + case _ => + accepted = false + } + + if (accepted) { + Some(Negotiated(WebSocketExtension(ExtensionName, responseParams), serverNoContext, clientNoContext, settings)) + } else None + } + + private def validWindowBits(value: String): Boolean = + value.length <= 2 && value.forall(_.isDigit) && { + val parsed = value.toInt + parsed >= 8 && parsed <= 15 + } + + private final class InflaterFlow( + noContextTakeover: Boolean, + settings: WebSocketCompressionSettingsImpl) + extends LifecycleMapConcat[FrameEventOrError, FrameEventOrError] { + private var inflater = new Inflater(true) + private var compressedFrame: Option[CompressedFrame] = None + private var compressedMessageInProgress = false + private var decompressedMessageBytes = 0L + private var bypassFrameInProgress = false + + override def apply(event: FrameEventOrError): immutable.Iterable[FrameEventOrError] = event match { + case start @ FrameStart(header, data) + if header.rsv1 && + (header.opcode == Protocol.Opcode.Text || + header.opcode == Protocol.Opcode.Binary) => + if (compressedMessageInProgress || compressedFrame.isDefined) + throw new ProtocolException("Unexpected data frame while fragmented message is open") + if (header.rsv2 || header.rsv3) throw new ProtocolException("Unexpected reserved bit for compressed message") + compressedMessageInProgress = !header.fin + compressedFrame = Some(CompressedFrame(header.copy(rsv1 = false, length = 0), data, appendTail = header.fin)) + if (start.lastPart) finishFrame() else Nil + case start @ FrameStart(header, _) if bypassFrameInProgress => + throw new ProtocolException(s"Unexpected frame ${header.opcode} while frame data is open") + case start @ FrameStart(header, _) + if (compressedFrame.isDefined || compressedMessageInProgress) && header.opcode.isControl => + bypassFrameInProgress = !start.lastPart + start :: Nil + case start @ FrameStart(header, data) + if compressedMessageInProgress && header.opcode == Protocol.Opcode.Continuation => + if (header.rsv1 || header.rsv2 || header.rsv3) + throw new ProtocolException("Unexpected reserved bit for continuation frame") + compressedMessageInProgress = !header.fin + compressedFrame = Some(CompressedFrame(header.copy(length = 0), data, appendTail = header.fin)) + if (start.lastPart) finishFrame() else Nil + case start @ FrameStart(header, _) if compressedFrame.isDefined || compressedMessageInProgress => + throw new ProtocolException(s"Unexpected frame ${header.opcode} while fragmented message is open") + case data: FrameData if bypassFrameInProgress => + bypassFrameInProgress = !data.lastPart + data :: Nil + case data: FrameData if compressedFrame.isDefined => + compressedFrame = compressedFrame.map(_.append(data.data)) + if (data.lastPart) finishFrame() else Nil + case other => other :: Nil + } + + private def finishFrame(): immutable.Iterable[FrameEventOrError] = { + val frame = compressedFrame.get + compressedFrame = None + val inflated = inflate(frame.data, frame.appendTail) + if (frame.appendTail) decompressedMessageBytes = 0L + if (frame.appendTail && noContextTakeover) { + inflater.end() + inflater = new Inflater(true) + } + FrameStart(frame.header.copy(length = inflated.length), inflated) :: Nil + } + + private def inflate(data: ByteString, appendTail: Boolean): ByteString = { + try { + val input = if (appendTail) data ++ EmptyStoredBlock else data + inflater.setInput(input.toArray) + val output = new ByteArrayOutputStream() + val buffer = new Array[Byte](1024) + var count = inflater.inflate(buffer) + while (count > 0) { + decompressedMessageBytes += count + if (settings.maxAllocation > 0 && decompressedMessageBytes > settings.maxAllocation) + throw new ProtocolException("WebSocket decompressed message exceeds configured maximum allocation") + output.write(buffer, 0, count) + count = inflater.inflate(buffer) + } + ByteString.fromArray(output.toByteArray) Review Comment: Addressed in the merged implementation: the freshly created output arrays are wrapped using `ByteString.fromArrayUnsafe`. They are not modified after ownership is transferred to the `ByteString`. Input uses `toArrayUnsafe` before being passed to the JDK inflater or deflater, which only reads that input. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
