1 files changed, 207 insertions, 0 deletions
diff --git a/netwerk/protocol/http/Http2Compression.h b/netwerk/protocol/http/Http2Compression.h
new file mode 100644
index 0000000000..ad47949938
--- /dev/null
+++ b/netwerk/protocol/http/Http2Compression.h
@@ -0,0 +1,207 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_Http2Compression_Internal_h
+#define mozilla_net_Http2Compression_Internal_h
+
+// HPACK - RFC 7541
+// https://www.rfc-editor.org/rfc/rfc7541.txt
+
+#include "mozilla/Attributes.h"
+#include "nsDeque.h"
+#include "nsString.h"
+#include "mozilla/Telemetry.h"
+#include "mozilla/Mutex.h"
+
+namespace mozilla {
+namespace net {
+
+struct HuffmanIncomingTable;
+
+void Http2CompressionCleanup();
+
+class nvPair {
+ public:
+  nvPair(const nsACString& name, const nsACString& value)
+      : mName(name), mValue(value) {}
+
+  uint32_t Size() const { return mName.Length() + mValue.Length() + 32; }
+  size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const;
+  size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const;
+
+  nsCString mName;
+  nsCString mValue;
+};
+
+class nvFIFO {
+ public:
+  nvFIFO();
+  ~nvFIFO();
+  void AddElement(const nsCString& name, const nsCString& value);
+  void AddElement(const nsCString& name);
+  void RemoveElement();
+  uint32_t ByteCount() const;
+  uint32_t Length() const;
+  uint32_t VariableLength() const;
+  size_t StaticLength() const;
+  void Clear();
+  const nvPair* operator[](size_t index) const;
+  size_t SizeOfDynamicTable(mozilla::MallocSizeOf aMallocSizeOf) const;
+
+ private:
+  uint32_t mByteCount{0};
+  nsDeque<nvPair> mTable;
+
+  // This mutex is held when adding or removing elements in the table
+  // and when accessing the table from the main thread (in SizeOfDynamicTable)
+  // Since the operator[] and other const methods are always called
+  // on the socket thread, they don't need to lock the mutex.
+  // Mutable so it can be locked in SizeOfDynamicTable which is const
+  mutable Mutex mMutex MOZ_UNANNOTATED{"nvFIFO"};
+};
+
+class HpackDynamicTableReporter;
+
+class Http2BaseCompressor {
+ public:
+  Http2BaseCompressor();
+  virtual ~Http2BaseCompressor();
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
+  nsresult SetInitialMaxBufferSize(uint32_t maxBufferSize);
+  void SetDumpTables(bool dumpTables);
+
+ protected:
+  const static uint32_t kDefaultMaxBuffer = 4096;
+
+  virtual void ClearHeaderTable();
+  virtual void MakeRoom(uint32_t amount, const char* direction);
+  virtual void DumpState(const char*);
+  virtual void SetMaxBufferSizeInternal(uint32_t maxBufferSize);
+
+  nsACString* mOutput{nullptr};
+  nvFIFO mHeaderTable;
+
+  uint32_t mMaxBuffer{kDefaultMaxBuffer};
+  uint32_t mMaxBufferSetting{kDefaultMaxBuffer};
+  bool mSetInitialMaxBufferSizeAllowed{true};
+
+  uint32_t mPeakSize{0};
+  uint32_t mPeakCount{0};
+  MOZ_INIT_OUTSIDE_CTOR
+  Telemetry::HistogramID mPeakSizeID;
+  MOZ_INIT_OUTSIDE_CTOR
+  Telemetry::HistogramID mPeakCountID;
+
+  bool mDumpTables{false};
+
+ private:
+  RefPtr<HpackDynamicTableReporter> mDynamicReporter;
+};
+
+class Http2Compressor;
+
+class Http2Decompressor final : public Http2BaseCompressor {
+ public:
+  Http2Decompressor() {
+    mPeakSizeID = Telemetry::HPACK_PEAK_SIZE_DECOMPRESSOR;
+    mPeakCountID = Telemetry::HPACK_PEAK_COUNT_DECOMPRESSOR;
+  };
+  virtual ~Http2Decompressor() = default;
+
+  // NS_OK: Produces the working set of HTTP/1 formatted headers
+  [[nodiscard]] nsresult DecodeHeaderBlock(const uint8_t* data,
+                                           uint32_t datalen, nsACString& output,
+                                           bool isPush);
+
+  void GetStatus(nsACString& hdr) { hdr = mHeaderStatus; }
+  void GetHost(nsACString& hdr) { hdr = mHeaderHost; }
+  void GetScheme(nsACString& hdr) { hdr = mHeaderScheme; }
+  void GetPath(nsACString& hdr) { hdr = mHeaderPath; }
+  void GetMethod(nsACString& hdr) { hdr = mHeaderMethod; }
+
+ private:
+  [[nodiscard]] nsresult DoIndexed();
+  [[nodiscard]] nsresult DoLiteralWithoutIndex();
+  [[nodiscard]] nsresult DoLiteralWithIncremental();
+  [[nodiscard]] nsresult DoLiteralInternal(nsACString&, nsACString&, uint32_t);
+  [[nodiscard]] nsresult DoLiteralNeverIndexed();
+  [[nodiscard]] nsresult DoContextUpdate();
+
+  [[nodiscard]] nsresult DecodeInteger(uint32_t prefixLen, uint32_t& accum);
+  [[nodiscard]] nsresult OutputHeader(uint32_t index);
+  [[nodiscard]] nsresult OutputHeader(const nsACString& name,
+                                      const nsACString& value);
+
+  [[nodiscard]] nsresult CopyHeaderString(uint32_t index, nsACString& name);
+  [[nodiscard]] nsresult CopyStringFromInput(uint32_t bytes, nsACString& val);
+  uint8_t ExtractByte(uint8_t bitsLeft, uint32_t& bytesConsumed);
+  [[nodiscard]] nsresult CopyHuffmanStringFromInput(uint32_t bytes,
+                                                    nsACString& val);
+  [[nodiscard]] nsresult DecodeHuffmanCharacter(
+      const HuffmanIncomingTable* table, uint8_t& c, uint32_t& bytesConsumed,
+      uint8_t& bitsLeft);
+  [[nodiscard]] nsresult DecodeFinalHuffmanCharacter(
+      const HuffmanIncomingTable* table, uint8_t& c, uint8_t& bitsLeft);
+
+  nsCString mHeaderStatus;
+  nsCString mHeaderHost;
+  nsCString mHeaderScheme;
+  nsCString mHeaderPath;
+  nsCString mHeaderMethod;
+
+  // state variables when DecodeBlock() is on the stack
+  uint32_t mOffset{0};
+  const uint8_t* mData{nullptr};
+  uint32_t mDataLen{0};
+  bool mSeenNonColonHeader{false};
+  bool mIsPush{false};
+};
+
+class Http2Compressor final : public Http2BaseCompressor {
+ public:
+  Http2Compressor() {
+    mPeakSizeID = Telemetry::HPACK_PEAK_SIZE_COMPRESSOR;
+    mPeakCountID = Telemetry::HPACK_PEAK_COUNT_COMPRESSOR;
+  };
+  virtual ~Http2Compressor() = default;
+
+  // HTTP/1 formatted header block as input - HTTP/2 formatted
+  // header block as output
+  [[nodiscard]] nsresult EncodeHeaderBlock(
+      const nsCString& nvInput, const nsACString& method,
+      const nsACString& path, const nsACString& host, const nsACString& scheme,
+      const nsACString& protocol, bool simpleConnectForm, nsACString& output);
+
+  int64_t GetParsedContentLength() {
+    return mParsedContentLength;
+  }  // -1 on not found
+
+  void SetMaxBufferSize(uint32_t maxBufferSize);
+
+ private:
+  enum outputCode {
+    kNeverIndexedLiteral,
+    kPlainLiteral,
+    kIndexedLiteral,
+    kIndex
+  };
+
+  void DoOutput(Http2Compressor::outputCode code, const class nvPair* pair,
+                uint32_t index);
+  void EncodeInteger(uint32_t prefixLen, uint32_t val);
+  void ProcessHeader(const nvPair inputPair, bool noLocalIndex,
+                     bool neverIndex);
+  void HuffmanAppend(const nsCString& value);
+  void EncodeTableSizeChange(uint32_t newMaxSize);
+
+  int64_t mParsedContentLength{-1};
+  bool mBufferSizeChangeWaiting{false};
+  uint32_t mLowestBufferSizeWaiting{0};
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // mozilla_net_Http2Compression_Internal_h