boost_beast/include/beast/websocket/rfc6455.hpp

//
// Copyright (c) 2013-2017 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef BEAST_WEBSOCKET_RFC6455_HPP
#define BEAST_WEBSOCKET_RFC6455_HPP

#include <beast/config.hpp>
#include <beast/core/static_string.hpp>
#include <boost/optional.hpp>
#include <array>
#include <cstdint>

namespace beast {
namespace websocket {

/** WebSocket frame header opcodes. */
enum class opcode : std::uint8_t
{
    cont    = 0,
    text    = 1,
    binary  = 2,
    rsv3    = 3,
    rsv4    = 4,
    rsv5    = 5,
    rsv6    = 6,
    rsv7    = 7,
    close   = 8,
    ping    = 9,
    pong    = 10,
    crsvb   = 11,
    crsvc   = 12,
    crsvd   = 13,
    crsve   = 14,
    crsvf   = 15
};

/** Close status codes.

    These codes accompany close frames.

    @see <a href="https://tools.ietf.org/html/rfc6455#section-7.4.1">RFC 6455 7.4.1 Defined Status Codes</a>

*/
enum close_code
{
    /// Normal closure; the connection successfully completed whatever purpose for which it was created.
    normal          = 1000,

    /// The endpoint is going away, either because of a server failure or because the browser is navigating away from the page that opened the connection.
    going_away      = 1001,

    /// The endpoint is terminating the connection due to a protocol error.
    protocol_error  = 1002,

    /// The connection is being terminated because the endpoint received data of a type it cannot accept (for example, a text-only endpoint received binary data).
    unknown_data    = 1003,

    /// The endpoint is terminating the connection because a message was received that contained inconsistent data (e.g., non-UTF-8 data within a text message).
    bad_payload     = 1007,

    /// The endpoint is terminating the connection because it received a message that violates its policy. This is a generic status code, used when codes 1003 and 1009 are not suitable.
    policy_error    = 1008,

    /// The endpoint is terminating the connection because a data frame was received that is too large.
    too_big         = 1009,

    /// The client is terminating the connection because it expected the server to negotiate one or more extension, but the server didn't.
    needs_extension = 1010,

    /// The server is terminating the connection because it encountered an unexpected condition that prevented it from fulfilling the request.
    internal_error  = 1011,

    /// The server is terminating the connection because it is restarting.
    service_restart = 1012,

    /// The server is terminating the connection due to a temporary condition, e.g. it is overloaded and is casting off some of its clients.
    try_again_later = 1013,

    //----
    //
    // The following are illegal on the wire
    //

    /** Used internally to mean "no error"

        This code is reserved and may not be sent.
    */
    none            = 0,

    /** Reserved for future use by the WebSocket standard.

        This code is reserved and may not be sent.
    */
    reserved1       = 1004,

    /** No status code was provided even though one was expected.

        This code is reserved and may not be sent.
    */
    no_status       = 1005,

    /** Connection was closed without receiving a close frame
        
        This code is reserved and may not be sent.
    */
    abnormal        = 1006,

    /** Reserved for future use by the WebSocket standard.
        
        This code is reserved and may not be sent.
    */
    reserved2       = 1014,

    /** Reserved for future use by the WebSocket standard.
       
        This code is reserved and may not be sent.
    */
    reserved3       = 1015

    //
    //----

    //last = 5000 // satisfy warnings
};

/// The type representing the reason string in a close frame.
using reason_string = static_string<123, char>;

/// The type representing the payload of ping and pong messages.
using ping_data = static_string<125, char>;

/** Description of the close reason.

    This object stores the close code (if any) and the optional
    utf-8 encoded implementation defined reason string.
*/
struct close_reason
{
    /// The close code.
    std::uint16_t code = close_code::none;

    /// The optional utf8-encoded reason string.
    reason_string reason;

    /** Default constructor.

        The code will be none. Default constructed objects
        will explicitly convert to bool as `false`.
    */
    close_reason() = default;

    /// Construct from a code.
    close_reason(std::uint16_t code_)
        : code(code_)
    {
    }

    /// Construct from a reason. code is close_code::normal.
    template<std::size_t N>
    close_reason(char const (&reason_)[N])
        : code(close_code::normal)
        , reason(reason_)
    {
    }

    /// Construct from a code and reason.
    template<std::size_t N>
    close_reason(close_code code_,
            char const (&reason_)[N])
        : code(code_)
        , reason(reason_)
    {
    }

    /// Returns `true` if a code was specified
    operator bool() const
    {
        return code != close_code::none;
    }
};

} // websocket
} // beast

#endif