Add new HTTP/2 and HPACK decoder in net/http2/.

net/http2/http2_structures.h

Index: net/http2/http2_structures.h
diff --git a/net/http2/http2_structures.h b/net/http2/http2_structures.h
new file mode 100644
index 0000000000000000000000000000000000000000..95328e1f5ab8d532ac16c83f1ff40ca7d9be9719
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+++ b/net/http2/http2_structures.h
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+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_HTTP2_HTTP2_STRUCTURES_H_
+#define NET_HTTP2_HTTP2_STRUCTURES_H_
+
+// Defines structs for various fixed sized structures in HTTP/2.
+//
+// Those structs with multiple fields have constructors that take arguments in
+// the same order as their encoding (which may be different from their order
+// in the struct). For single field structs, use aggregate initialization if
+// desired, e.g.:
+//
+//   Http2RstStreamFields var{Http2ErrorCode::ENHANCE_YOUR_CALM};
+// or:
+//   SomeFunc(Http2RstStreamFields{Http2ErrorCode::ENHANCE_YOUR_CALM});
+//
+// Each struct includes a static method EncodedSize which returns the number
+// of bytes of the encoding.
+//
+// With the exception of Http2FrameHeader, all the types are named
+// Http2<X>Fields, where X is the title-case form of the frame which always
+// includes the fields; the "always" is to cover the case of the PRIORITY frame;
+// its fields optionally appear in the HEADERS frame, but the struct is called
+// Http2PriorityFields.
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <ostream>
+#include <string>
+
+#include "base/logging.h"
+#include "net/base/net_export.h"
+#include "net/http2/http2_constants.h"
+
+namespace net {
+
+struct NET_EXPORT_PRIVATE Http2FrameHeader {
+  Http2FrameHeader() {}
+  Http2FrameHeader(uint32_t payload_length,
+                   Http2FrameType type,
+                   uint8_t flags,
+                   uint32_t stream_id)
+      : payload_length(payload_length),
+        stream_id(stream_id),
+        type(type),
+        flags(static_cast<Http2FrameFlag>(flags)) {
+    DCHECK_LT(payload_length, static_cast<uint32_t>(1 << 24))
+        << "Payload Length is only a 24 bit field\n"
+        << ToString();
+  }
+
+  static constexpr size_t EncodedSize() { return 9; }
+
+  // Keep the current value of those flags that are in
+  // valid_flags, and clear all the others.
+  void RetainFlags(uint8_t valid_flags) {
+    flags = static_cast<Http2FrameFlag>(flags & valid_flags);
+  }
+
+  // Returns true if any of the flags in flag_mask are set,
+  // otherwise false.
+  bool HasAnyFlags(uint8_t flag_mask) const { return 0 != (flags & flag_mask); }
+
+  // Is the END_STREAM flag set?
+  bool IsEndStream() const {
+    DCHECK(type == Http2FrameType::DATA || type == Http2FrameType::HEADERS)
+        << ToString();
+    return (flags & Http2FrameFlag::FLAG_END_STREAM) != 0;
+  }
+
+  // Is the ACK flag set?
+  bool IsAck() const {
+    DCHECK(type == Http2FrameType::SETTINGS || type == Http2FrameType::PING)
+        << ToString();
+    return (flags & Http2FrameFlag::FLAG_ACK) != 0;
+  }
+
+  // Is the END_HEADERS flag set?
+  bool IsEndHeaders() const {
+    DCHECK(type == Http2FrameType::HEADERS ||
+           type == Http2FrameType::PUSH_PROMISE ||
+           type == Http2FrameType::CONTINUATION)
+        << ToString();
+    return (flags & Http2FrameFlag::FLAG_END_HEADERS) != 0;
+  }
+
+  // Is the PADDED flag set?
+  bool IsPadded() const {
+    DCHECK(type == Http2FrameType::DATA || type == Http2FrameType::HEADERS ||
+           type == Http2FrameType::PUSH_PROMISE)
+        << ToString();
+    return (flags & Http2FrameFlag::FLAG_PADDED) != 0;
+  }
+
+  // Is the PRIORITY flag set?
+  bool HasPriority() const {
+    DCHECK_EQ(type, Http2FrameType::HEADERS) << ToString();
+    return (flags & Http2FrameFlag::FLAG_PRIORITY) != 0;
+  }
+
+  // Does the encoding of this header start with "HTTP/", indicating that it
+  // might be from a non-HTTP/2 server.
+  bool IsProbableHttpResponse() const;
+
+  // Produce strings useful for debugging/logging messages.
+  std::string ToString() const;
+  std::string FlagsToString() const;
+
+  // 24 bit length of the payload after the header, including any padding.
+  // First field in encoding.
+  uint32_t payload_length;  // 24 bits
+
+  // 31 bit stream id, with high bit (32nd bit) reserved (must be zero),
+  // and is cleared during decoding.
+  // Fourth field in encoding.
+  uint32_t stream_id;
+
+  // Type of the frame.
+  // Second field in encoding.
+  Http2FrameType type;
+
+  // Flag bits, with interpretations that depend upon the frame type.
+  // Flag bits not used by the frame type are cleared.
+  // Third field in encoding.
+  Http2FrameFlag flags;
+};
+
+NET_EXPORT_PRIVATE bool operator==(const Http2FrameHeader& a,
+                                   const Http2FrameHeader& b);
+NET_EXPORT_PRIVATE inline bool operator!=(const Http2FrameHeader& a,
+                                          const Http2FrameHeader& b) {
+  return !(a == b);
+}
+NET_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& out,
+                                            const Http2FrameHeader& v);
+
+// Http2PriorityFields:
+
+struct NET_EXPORT_PRIVATE Http2PriorityFields {
+  Http2PriorityFields() {}
+  Http2PriorityFields(uint32_t stream_dependency,
+                      uint32_t weight,
+                      bool is_exclusive)
+      : stream_dependency(stream_dependency),
+        weight(weight),
+        is_exclusive(is_exclusive) {
+    // Can't have the high-bit set in the stream id because we need to use
+    // that for the EXCLUSIVE flag bit.
+    DCHECK_EQ(stream_dependency, stream_dependency & StreamIdMask())
+        << "Stream Dependency is only a 31-bit field.\n"
+        << ToString();
+    DCHECK_LE(1u, weight) << "Weight is too small.";
+    DCHECK_LE(weight, 256u) << "Weight is too large.";
+  }
+  static constexpr size_t EncodedSize() { return 5; }
+
+  // Produce strings useful for debugging/logging messages.
+  std::string ToString() const;
+
+  // A 31-bit stream identifier for the stream that this stream depends on.
+  uint32_t stream_dependency;
+
+  // Weight (1 to 256) is encoded as a byte in the range 0 to 255, so we
+  // add one when decoding, and store it in a field larger than a byte.
+  uint32_t weight;
+
+  // A single-bit flag indicating that the stream dependency is exclusive;
+  // extracted from high bit of stream dependency field during decoding.
+  bool is_exclusive;
+};
+
+NET_EXPORT_PRIVATE bool operator==(const Http2PriorityFields& a,
+                                   const Http2PriorityFields& b);
+NET_EXPORT_PRIVATE inline bool operator!=(const Http2PriorityFields& a,
+                                          const Http2PriorityFields& b) {
+  return !(a == b);
+}
+NET_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& out,
+                                            const Http2PriorityFields& v);
+
+// Http2RstStreamFields:
+
+struct Http2RstStreamFields {
+  static constexpr size_t EncodedSize() { return 4; }
+  bool IsSupportedErrorCode() const {
+    return IsSupportedHttp2ErrorCode(error_code);
+  }
+
+  Http2ErrorCode error_code;
+};
+
+NET_EXPORT_PRIVATE bool operator==(const Http2RstStreamFields& a,
+                                   const Http2RstStreamFields& b);
+NET_EXPORT_PRIVATE inline bool operator!=(const Http2RstStreamFields& a,
+                                          const Http2RstStreamFields& b) {
+  return !(a == b);
+}
+NET_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& out,
+                                            const Http2RstStreamFields& v);
+
+// Http2SettingFields:
+
+struct Http2SettingFields {
+  Http2SettingFields() {}
+  Http2SettingFields(Http2SettingsParameter parameter, uint32_t value)
+      : parameter(parameter), value(value) {}
+  static constexpr size_t EncodedSize() { return 6; }
+  bool IsSupportedParameter() const {
+    return IsSupportedHttp2SettingsParameter(parameter);
+  }
+
+  Http2SettingsParameter parameter;
+  uint32_t value;
+};
+
+NET_EXPORT_PRIVATE bool operator==(const Http2SettingFields& a,
+                                   const Http2SettingFields& b);
+NET_EXPORT_PRIVATE inline bool operator!=(const Http2SettingFields& a,
+                                          const Http2SettingFields& b) {
+  return !(a == b);
+}
+NET_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& out,
+                                            const Http2SettingFields& v);
+
+// Http2PushPromiseFields:
+
+struct Http2PushPromiseFields {
+  static constexpr size_t EncodedSize() { return 4; }
+
+  uint32_t promised_stream_id;
+};
+
+NET_EXPORT_PRIVATE bool operator==(const Http2PushPromiseFields& a,
+                                   const Http2PushPromiseFields& b);
+NET_EXPORT_PRIVATE inline bool operator!=(const Http2PushPromiseFields& a,
+                                          const Http2PushPromiseFields& b) {
+  return !(a == b);
+}
+NET_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& out,
+                                            const Http2PushPromiseFields& v);
+
+// Http2PingFields:
+
+struct Http2PingFields {
+  static constexpr size_t EncodedSize() { return 8; }
+
+  // TODO(jamessynge): Rename opaque_data to opaque_bytes.
+  uint8_t opaque_data[8];
+};
+
+NET_EXPORT_PRIVATE bool operator==(const Http2PingFields& a,
+                                   const Http2PingFields& b);
+NET_EXPORT_PRIVATE inline bool operator!=(const Http2PingFields& a,
+                                          const Http2PingFields& b) {
+  return !(a == b);
+}
+NET_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& out,
+                                            const Http2PingFields& v);
+
+// Http2GoAwayFields:
+
+struct Http2GoAwayFields {
+  Http2GoAwayFields() {}
+  Http2GoAwayFields(uint32_t last_stream_id, Http2ErrorCode error_code)
+      : last_stream_id(last_stream_id), error_code(error_code) {}
+  static constexpr size_t EncodedSize() { return 8; }
+  bool IsSupportedErrorCode() const {
+    return IsSupportedHttp2ErrorCode(error_code);
+  }
+
+  uint32_t last_stream_id;
+  Http2ErrorCode error_code;
+};
+
+NET_EXPORT_PRIVATE bool operator==(const Http2GoAwayFields& a,
+                                   const Http2GoAwayFields& b);
+NET_EXPORT_PRIVATE inline bool operator!=(const Http2GoAwayFields& a,
+                                          const Http2GoAwayFields& b) {
+  return !(a == b);
+}
+NET_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& out,
+                                            const Http2GoAwayFields& v);
+
+// Http2WindowUpdateFields:
+
+struct Http2WindowUpdateFields {
+  static constexpr size_t EncodedSize() { return 4; }
+
+  // 31-bit, unsigned increase in the window size (only positive values are
+  // allowed). The high-bit is reserved for the future.
+  uint32_t window_size_increment;
+};
+
+NET_EXPORT_PRIVATE bool operator==(const Http2WindowUpdateFields& a,
+                                   const Http2WindowUpdateFields& b);
+NET_EXPORT_PRIVATE inline bool operator!=(const Http2WindowUpdateFields& a,
+                                          const Http2WindowUpdateFields& b) {
+  return !(a == b);
+}
+NET_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& out,
+                                            const Http2WindowUpdateFields& v);
+
+// Http2AltSvcFields:
+
+struct Http2AltSvcFields {
+  static constexpr size_t EncodedSize() { return 2; }
+
+  // This is the one fixed size portion of the ALTSVC payload.
+  uint16_t origin_length;
+};
+
+NET_EXPORT_PRIVATE bool operator==(const Http2AltSvcFields& a,
+                                   const Http2AltSvcFields& b);
+NET_EXPORT_PRIVATE inline bool operator!=(const Http2AltSvcFields& a,
+                                          const Http2AltSvcFields& b) {
+  return !(a == b);
+}
+NET_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& out,
+                                            const Http2AltSvcFields& v);
+
+}  // namespace net
+
+#endif  // NET_HTTP2_HTTP2_STRUCTURES_H_