| // 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_CONSTANTS_H_ |
| #define NET_HTTP2_HTTP2_CONSTANTS_H_ |
| |
| // Constants from the HTTP/2 spec, RFC 7540, and associated helper functions. |
| |
| #include <stdint.h> |
| |
| #include <iosfwd> |
| #include <ostream> |
| |
| #include "net/http2/platform/api/http2_export.h" |
| #include "net/http2/platform/api/http2_string.h" |
| |
| namespace net { |
| |
| // TODO(jamessynge): create http2_simple_types for types similar to |
| // SpdyStreamId, but not for structures like Http2FrameHeader. Then will be |
| // able to move these stream id functions there. |
| constexpr uint32_t UInt31Mask() { |
| return 0x7fffffff; |
| } |
| constexpr uint32_t StreamIdMask() { |
| return UInt31Mask(); |
| } |
| |
| // The value used to identify types of frames. Upper case to match the RFC. |
| // The comments indicate which flags are valid for that frame type. |
| // ALTSVC is defined in http://httpwg.org/http-extensions/alt-svc.html |
| // (not yet final standard as of March 2016, but close). |
| enum class Http2FrameType : uint8_t { |
| DATA = 0, // END_STREAM | PADDED |
| HEADERS = 1, // END_STREAM | END_HEADERS | PADDED | PRIORITY |
| PRIORITY = 2, // |
| RST_STREAM = 3, // |
| SETTINGS = 4, // ACK |
| PUSH_PROMISE = 5, // END_HEADERS | PADDED |
| PING = 6, // ACK |
| GOAWAY = 7, // |
| WINDOW_UPDATE = 8, // |
| CONTINUATION = 9, // END_HEADERS |
| ALTSVC = 10, // |
| }; |
| |
| // Is the frame type known/supported? |
| inline bool IsSupportedHttp2FrameType(uint32_t v) { |
| return v <= static_cast<uint32_t>(Http2FrameType::ALTSVC); |
| } |
| inline bool IsSupportedHttp2FrameType(Http2FrameType v) { |
| return IsSupportedHttp2FrameType(static_cast<uint32_t>(v)); |
| } |
| |
| // The return type is 'string' so that they can generate a unique string for |
| // each unsupported value. Since these are just used for debugging/error |
| // messages, that isn't a cost to we need to worry about. |
| // The same applies to the functions later in this file. |
| HTTP2_EXPORT_PRIVATE Http2String Http2FrameTypeToString(Http2FrameType v); |
| HTTP2_EXPORT_PRIVATE Http2String Http2FrameTypeToString(uint8_t v); |
| HTTP2_EXPORT_PRIVATE inline std::ostream& operator<<(std::ostream& out, |
| Http2FrameType v) { |
| return out << Http2FrameTypeToString(v); |
| } |
| |
| // Flags that appear in supported frame types. These are treated as bit masks. |
| // The comments indicate for which frame types the flag is valid. |
| enum Http2FrameFlag { |
| END_STREAM = 0x01, // DATA, HEADERS |
| ACK = 0x01, // SETTINGS, PING |
| END_HEADERS = 0x04, // HEADERS, PUSH_PROMISE, CONTINUATION |
| PADDED = 0x08, // DATA, HEADERS, PUSH_PROMISE |
| PRIORITY = 0x20, // HEADERS |
| }; |
| |
| // Formats zero or more flags for the specified type of frame. Returns an |
| // empty string if flags==0. |
| HTTP2_EXPORT_PRIVATE Http2String Http2FrameFlagsToString(Http2FrameType type, |
| uint8_t flags); |
| HTTP2_EXPORT_PRIVATE Http2String Http2FrameFlagsToString(uint8_t type, |
| uint8_t flags); |
| |
| // Error codes for GOAWAY and RST_STREAM frames. |
| enum class Http2ErrorCode : uint32_t { |
| // The associated condition is not a result of an error. For example, a GOAWAY |
| // might include this code to indicate graceful shutdown of a connection. |
| HTTP2_NO_ERROR = 0x0, |
| |
| // The endpoint detected an unspecific protocol error. This error is for use |
| // when a more specific error code is not available. |
| PROTOCOL_ERROR = 0x1, |
| |
| // The endpoint encountered an unexpected internal error. |
| INTERNAL_ERROR = 0x2, |
| |
| // The endpoint detected that its peer violated the flow-control protocol. |
| FLOW_CONTROL_ERROR = 0x3, |
| |
| // The endpoint sent a SETTINGS frame but did not receive a response in a |
| // timely manner. See Section 6.5.3 ("Settings Synchronization"). |
| SETTINGS_TIMEOUT = 0x4, |
| |
| // The endpoint received a frame after a stream was half-closed. |
| STREAM_CLOSED = 0x5, |
| |
| // The endpoint received a frame with an invalid size. |
| FRAME_SIZE_ERROR = 0x6, |
| |
| // The endpoint refused the stream prior to performing any application |
| // processing (see Section 8.1.4 for details). |
| REFUSED_STREAM = 0x7, |
| |
| // Used by the endpoint to indicate that the stream is no longer needed. |
| CANCEL = 0x8, |
| |
| // The endpoint is unable to maintain the header compression context |
| // for the connection. |
| COMPRESSION_ERROR = 0x9, |
| |
| // The connection established in response to a CONNECT request (Section 8.3) |
| // was reset or abnormally closed. |
| CONNECT_ERROR = 0xa, |
| |
| // The endpoint detected that its peer is exhibiting a behavior that might |
| // be generating excessive load. |
| ENHANCE_YOUR_CALM = 0xb, |
| |
| // The underlying transport has properties that do not meet minimum |
| // security requirements (see Section 9.2). |
| INADEQUATE_SECURITY = 0xc, |
| |
| // The endpoint requires that HTTP/1.1 be used instead of HTTP/2. |
| HTTP_1_1_REQUIRED = 0xd, |
| }; |
| |
| // Is the error code supported? (So far that means it is in RFC 7540.) |
| inline bool IsSupportedHttp2ErrorCode(uint32_t v) { |
| return v <= static_cast<uint32_t>(Http2ErrorCode::HTTP_1_1_REQUIRED); |
| } |
| inline bool IsSupportedHttp2ErrorCode(Http2ErrorCode v) { |
| return IsSupportedHttp2ErrorCode(static_cast<uint32_t>(v)); |
| } |
| |
| // Format the specified error code. |
| HTTP2_EXPORT_PRIVATE Http2String Http2ErrorCodeToString(uint32_t v); |
| HTTP2_EXPORT_PRIVATE Http2String Http2ErrorCodeToString(Http2ErrorCode v); |
| HTTP2_EXPORT_PRIVATE inline std::ostream& operator<<(std::ostream& out, |
| Http2ErrorCode v) { |
| return out << Http2ErrorCodeToString(v); |
| } |
| |
| // Supported parameters in SETTINGS frames; so far just those in RFC 7540. |
| enum class Http2SettingsParameter : uint16_t { |
| // Allows the sender to inform the remote endpoint of the maximum size of the |
| // header compression table used to decode header blocks, in octets. The |
| // encoder can select any size equal to or less than this value by using |
| // signaling specific to the header compression format inside a header block |
| // (see [COMPRESSION]). The initial value is 4,096 octets. |
| HEADER_TABLE_SIZE = 0x1, |
| |
| // This setting can be used to disable server push (Section 8.2). An endpoint |
| // MUST NOT send a PUSH_PROMISE frame if it receives this parameter set to a |
| // value of 0. An endpoint that has both set this parameter to 0 and had it |
| // acknowledged MUST treat the receipt of a PUSH_PROMISE frame as a connection |
| // error (Section 5.4.1) of type PROTOCOL_ERROR. |
| // |
| // The initial value is 1, which indicates that server push is permitted. Any |
| // value other than 0 or 1 MUST be treated as a connection error (Section |
| // 5.4.1) of type PROTOCOL_ERROR. |
| ENABLE_PUSH = 0x2, |
| |
| // Indicates the maximum number of concurrent streams that the sender will |
| // allow. This limit is directional: it applies to the number of streams that |
| // the sender permits the receiver to create. Initially, there is no limit to |
| // this value. It is recommended that this value be no smaller than 100, so as |
| // to not unnecessarily limit parallelism. |
| // |
| // A value of 0 for MAX_CONCURRENT_STREAMS SHOULD NOT be treated as |
| // special by endpoints. A zero value does prevent the creation of new |
| // streams; however, this can also happen for any limit that is exhausted with |
| // active streams. Servers SHOULD only set a zero value for short durations; |
| // if a server does not wish to accept requests, closing the connection is |
| // more appropriate. |
| MAX_CONCURRENT_STREAMS = 0x3, |
| |
| // Indicates the sender's initial window size (in octets) for stream-level |
| // flow control. The initial value is 2^16-1 (65,535) octets. |
| // |
| // This setting affects the window size of all streams (see Section 6.9.2). |
| // |
| // Values above the maximum flow-control window size of 2^31-1 MUST be treated |
| // as a connection error (Section 5.4.1) of type FLOW_CONTROL_ERROR. |
| INITIAL_WINDOW_SIZE = 0x4, |
| |
| // Indicates the size of the largest frame payload that the sender is willing |
| // to receive, in octets. |
| // |
| // The initial value is 2^14 (16,384) octets. The value advertised by an |
| // endpoint MUST be between this initial value and the maximum allowed frame |
| // size (2^24-1 or 16,777,215 octets), inclusive. Values outside this range |
| // MUST be treated as a connection error (Section 5.4.1) of type |
| // PROTOCOL_ERROR. |
| MAX_FRAME_SIZE = 0x5, |
| |
| // This advisory setting informs a peer of the maximum size of header list |
| // that the sender is prepared to accept, in octets. The value is based on the |
| // uncompressed size of header fields, including the length of the name and |
| // value in octets plus an overhead of 32 octets for each header field. |
| // |
| // For any given request, a lower limit than what is advertised MAY be |
| // enforced. The initial value of this setting is unlimited. |
| MAX_HEADER_LIST_SIZE = 0x6, |
| }; |
| |
| // Is the settings parameter supported (so far that means it is in RFC 7540)? |
| inline bool IsSupportedHttp2SettingsParameter(uint32_t v) { |
| return 0 < v && |
| v <= static_cast<uint32_t>( |
| Http2SettingsParameter::MAX_HEADER_LIST_SIZE); |
| } |
| inline bool IsSupportedHttp2SettingsParameter(Http2SettingsParameter v) { |
| return IsSupportedHttp2SettingsParameter(static_cast<uint32_t>(v)); |
| } |
| |
| // Format the specified settings parameter. |
| HTTP2_EXPORT_PRIVATE Http2String Http2SettingsParameterToString(uint32_t v); |
| HTTP2_EXPORT_PRIVATE Http2String |
| Http2SettingsParameterToString(Http2SettingsParameter v); |
| inline std::ostream& operator<<(std::ostream& out, Http2SettingsParameter v) { |
| return out << Http2SettingsParameterToString(v); |
| } |
| |
| // Information about the initial, minimum and maximum value of settings (not |
| // applicable to all settings parameters). |
| class Http2SettingsInfo { |
| public: |
| // Default value for HEADER_TABLE_SIZE. |
| static constexpr uint32_t DefaultHeaderTableSize() { return 4096; } |
| |
| // Default value for ENABLE_PUSH. |
| static constexpr bool DefaultEnablePush() { return true; } |
| |
| // Default value for INITIAL_WINDOW_SIZE. |
| static constexpr uint32_t DefaultInitialWindowSize() { return 65535; } |
| |
| // Maximum value for INITIAL_WINDOW_SIZE, and for the connection flow control |
| // window, and for each stream flow control window. |
| static constexpr uint32_t MaximumWindowSize() { return UInt31Mask(); } |
| |
| // Default value for MAX_FRAME_SIZE. |
| static constexpr uint32_t DefaultMaxFrameSize() { return 16384; } |
| |
| // Minimum value for MAX_FRAME_SIZE. |
| static constexpr uint32_t MinimumMaxFrameSize() { return 16384; } |
| |
| // Maximum value for MAX_FRAME_SIZE. |
| static constexpr uint32_t MaximumMaxFrameSize() { return (1 << 24) - 1; } |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_HTTP2_HTTP2_CONSTANTS_H_ |