boost_beast/include/boost/beast/websocket/impl/accept.ipp

//
// Copyright (c) 2016-2017 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)
//
// Official repository: https://github.com/boostorg/beast
//

#ifndef BOOST_BEAST_WEBSOCKET_IMPL_ACCEPT_IPP
#define BOOST_BEAST_WEBSOCKET_IMPL_ACCEPT_IPP

#include <boost/beast/websocket/detail/type_traits.hpp>
#include <boost/beast/http/empty_body.hpp>
#include <boost/beast/http/parser.hpp>
#include <boost/beast/http/read.hpp>
#include <boost/beast/http/string_body.hpp>
#include <boost/beast/http/write.hpp>
#include <boost/beast/core/async_op_base.hpp>
#include <boost/beast/core/buffers_prefix.hpp>
#include <boost/beast/core/detail/buffer.hpp>
#include <boost/beast/core/detail/get_executor_type.hpp>
#include <boost/beast/core/detail/type_traits.hpp>
#include <boost/asio/coroutine.hpp>
#include <boost/asio/post.hpp>
#include <boost/assert.hpp>
#include <boost/throw_exception.hpp>
#include <memory>
#include <type_traits>

namespace boost {
namespace beast {
namespace websocket {

// Respond to an upgrade HTTP request
template<class NextLayer, bool deflateSupported>
template<class Handler>
class stream<NextLayer, deflateSupported>::response_op
    : public beast::stable_async_op_base<
        Handler, beast::detail::get_executor_type<stream>>
    , public net::coroutine
{
    struct data
    {
        stream<NextLayer, deflateSupported>& ws;
        error_code result;
        response_type res;

        template<class Body, class Allocator, class Decorator>
        data(
            stream<NextLayer, deflateSupported>& ws_,
            http::request<Body,
                http::basic_fields<Allocator>> const& req,
            Decorator const& decorator)
            : ws(ws_)
            , res(ws_.build_response(req, decorator, result))
        {
        }
    };

    data& d_;

public:
    template<
        class Handler_,
        class... Args>
    response_op(
        Handler_&& h,
        stream<NextLayer, deflateSupported>& ws,
        Args&&... args)
        : stable_async_op_base<
            Handler, beast::detail::get_executor_type<stream>>(
                std::forward<Handler_>(h), ws.get_executor())
        , d_(beast::allocate_stable<data>(
            *this,  ws, std::forward<Args>(args)...))
    {
    }

    void operator()(
        error_code ec = {},
        std::size_t bytes_transferred = 0)
    {
        boost::ignore_unused(bytes_transferred);

        BOOST_ASIO_CORO_REENTER(*this)
        {
            // Send response
            BOOST_ASIO_CORO_YIELD
            http::async_write(d_.ws.next_layer(),
                d_.res, std::move(*this));
            if(! ec)
                ec = d_.result;
            if(! ec)
            {
                d_.ws.do_pmd_config(d_.res);
                d_.ws.open(role_type::server);
            }
            this->invoke(ec);
        }
    }
};

//------------------------------------------------------------------------------

// read and respond to an upgrade request
//
template<class NextLayer, bool deflateSupported>
template<class Decorator, class Handler>
class stream<NextLayer, deflateSupported>::accept_op
    : public beast::stable_async_op_base<
        Handler, beast::detail::get_executor_type<stream>>
    , public net::coroutine
{
    struct data
    {
        stream<NextLayer, deflateSupported>& ws;
        Decorator decorator;
        http::request_parser<http::empty_body> p;

        data(
            stream<NextLayer, deflateSupported>& ws_,
            Decorator const& decorator_)
            : ws(ws_)
            , decorator(decorator_)
        {
        }
    };

    data& d_;

public:
    template<
        class Handler_,
        class... Args>
    accept_op(
        Handler_&& h,
        stream<NextLayer, deflateSupported>& ws,
        Args&&... args)
        : stable_async_op_base<
            Handler, beast::detail::get_executor_type<stream>>(
                std::forward<Handler_>(h), ws.get_executor())
        , d_(beast::allocate_stable<data>(
            *this,  ws, std::forward<Args>(args)...))
    {
    }

    template<class Buffers>
    void run(Buffers const& buffers)
    {
        using net::buffer_copy;
        using net::buffer_size;
        error_code ec;
        auto const mb = beast::detail::dynamic_buffer_prepare(
            d_.ws.rd_buf_, buffer_size(buffers), ec,
                error::buffer_overflow);
        if(ec)
            return (*this)(ec);
        d_.ws.rd_buf_.commit(buffer_copy(*mb, buffers));
        (*this)(ec);
    }

    void operator()(
        error_code ec = {},
        std::size_t bytes_used = 0)
    {
        boost::ignore_unused(bytes_used);

        BOOST_ASIO_CORO_REENTER(*this)
        {
            if(ec)
            {
                BOOST_ASIO_CORO_YIELD
                net::post(
                    d_.ws.get_executor(),
                    beast::bind_front_handler(std::move(*this), ec));
            }
            else
            {
                BOOST_ASIO_CORO_YIELD
                http::async_read(
                    d_.ws.next_layer(), d_.ws.rd_buf_,
                        d_.p, std::move(*this));
                if(ec == http::error::end_of_stream)
                    ec = error::closed;
                if(! ec)
                {
                    // Arguments from our state must be
                    // moved to the stack before releasing
                    // the handler.
                    auto& ws = d_.ws;
                    auto const req = d_.p.release();
                    auto const decorator = d_.decorator;
                #if 1
                    return response_op<Handler>{
                        this->release_handler(),
                            ws, req, decorator}(ec);
                #else
                    // VFALCO This *should* work but breaks
                    //        coroutine invariants in the unit test.
                    //        Also it calls reset() when it shouldn't.
                    return ws.async_accept_ex(
                        req, decorator, this->release_handler());
                #endif
                }
            }
            this->invoke(ec);
        }
    }
};

//------------------------------------------------------------------------------

template<class NextLayer, bool deflateSupported>
void
stream<NextLayer, deflateSupported>::
accept()
{
    static_assert(is_sync_stream<next_layer_type>::value,
        "SyncStream requirements not met");
    error_code ec;
    accept(ec);
    if(ec)
        BOOST_THROW_EXCEPTION(system_error{ec});
}

template<class NextLayer, bool deflateSupported>
template<class ResponseDecorator>
void
stream<NextLayer, deflateSupported>::
accept_ex(ResponseDecorator const& decorator)
{
    static_assert(is_sync_stream<next_layer_type>::value,
        "SyncStream requirements not met");
    static_assert(detail::is_response_decorator<
        ResponseDecorator>::value,
            "ResponseDecorator requirements not met");
    error_code ec;
    accept_ex(decorator, ec);
    if(ec)
        BOOST_THROW_EXCEPTION(system_error{ec});
}

template<class NextLayer, bool deflateSupported>
void
stream<NextLayer, deflateSupported>::
accept(error_code& ec)
{
    static_assert(is_sync_stream<next_layer_type>::value,
        "SyncStream requirements not met");
    reset();
    do_accept(&default_decorate_res, ec);
}

template<class NextLayer, bool deflateSupported>
template<class ResponseDecorator>
void
stream<NextLayer, deflateSupported>::
accept_ex(ResponseDecorator const& decorator, error_code& ec)
{
    static_assert(is_sync_stream<next_layer_type>::value,
        "SyncStream requirements not met");
    static_assert(detail::is_response_decorator<
        ResponseDecorator>::value,
            "ResponseDecorator requirements not met");
    reset();
    do_accept(decorator, ec);
}

template<class NextLayer, bool deflateSupported>
template<class ConstBufferSequence>
typename std::enable_if<! http::detail::is_header<
    ConstBufferSequence>::value>::type
stream<NextLayer, deflateSupported>::
accept(ConstBufferSequence const& buffers)
{
    static_assert(is_sync_stream<next_layer_type>::value,
        "SyncStream requirements not met");
    static_assert(net::is_const_buffer_sequence<
        ConstBufferSequence>::value,
            "ConstBufferSequence requirements not met");
    error_code ec;
    accept(buffers, ec);
    if(ec)
        BOOST_THROW_EXCEPTION(system_error{ec});
}

template<class NextLayer, bool deflateSupported>
template<
    class ConstBufferSequence,
    class ResponseDecorator>
typename std::enable_if<! http::detail::is_header<
    ConstBufferSequence>::value>::type
stream<NextLayer, deflateSupported>::
accept_ex(
    ConstBufferSequence const& buffers,
    ResponseDecorator const &decorator)
{
    static_assert(is_sync_stream<next_layer_type>::value,
        "SyncStream requirements not met");
    static_assert(net::is_const_buffer_sequence<
        ConstBufferSequence>::value,
            "ConstBufferSequence requirements not met");
    static_assert(detail::is_response_decorator<
        ResponseDecorator>::value,
            "ResponseDecorator requirements not met");
    error_code ec;
    accept_ex(buffers, decorator, ec);
    if(ec)
        BOOST_THROW_EXCEPTION(system_error{ec});
}

template<class NextLayer, bool deflateSupported>
template<class ConstBufferSequence>
typename std::enable_if<! http::detail::is_header<
    ConstBufferSequence>::value>::type
stream<NextLayer, deflateSupported>::
accept(
    ConstBufferSequence const& buffers, error_code& ec)
{
    static_assert(is_sync_stream<next_layer_type>::value,
        "SyncStream requirements not met");
    static_assert(net::is_const_buffer_sequence<
        ConstBufferSequence>::value,
            "ConstBufferSequence requirements not met");
    using net::buffer_copy;
    using net::buffer_size;
    reset();
    auto const mb = beast::detail::dynamic_buffer_prepare(
        rd_buf_, buffer_size(buffers), ec,
            error::buffer_overflow);
    if(ec)
        return;
    rd_buf_.commit(buffer_copy(*mb, buffers));
    do_accept(&default_decorate_res, ec);
}

template<class NextLayer, bool deflateSupported>
template<
    class ConstBufferSequence,
    class ResponseDecorator>
typename std::enable_if<! http::detail::is_header<
    ConstBufferSequence>::value>::type
stream<NextLayer, deflateSupported>::
accept_ex(
    ConstBufferSequence const& buffers,
    ResponseDecorator const& decorator,
    error_code& ec)
{
    static_assert(is_sync_stream<next_layer_type>::value,
        "SyncStream requirements not met");
    static_assert(net::is_const_buffer_sequence<
        ConstBufferSequence>::value,
            "ConstBufferSequence requirements not met");
    static_assert(net::is_const_buffer_sequence<
        ConstBufferSequence>::value,
            "ConstBufferSequence requirements not met");
    using net::buffer_copy;
    using net::buffer_size;
    reset();
    auto const mb = beast::detail::dynamic_buffer_prepare(
        rd_buf_, buffer_size(buffers), ec,
            error::buffer_overflow);
    if(ec)
        return;
    rd_buf_.commit(buffer_copy(*mb, buffers));
    do_accept(decorator, ec);
}

template<class NextLayer, bool deflateSupported>
template<class Body, class Allocator>
void
stream<NextLayer, deflateSupported>::
accept(
    http::request<Body,
        http::basic_fields<Allocator>> const& req)
{
    static_assert(is_sync_stream<next_layer_type>::value,
        "SyncStream requirements not met");
    error_code ec;
    accept(req, ec);
    if(ec)
        BOOST_THROW_EXCEPTION(system_error{ec});
}

template<class NextLayer, bool deflateSupported>
template<
    class Body, class Allocator,
    class ResponseDecorator>
void
stream<NextLayer, deflateSupported>::
accept_ex(
    http::request<Body,
        http::basic_fields<Allocator>> const& req,
    ResponseDecorator const& decorator)
{
    static_assert(is_sync_stream<next_layer_type>::value,
        "SyncStream requirements not met");
    static_assert(detail::is_response_decorator<
        ResponseDecorator>::value,
            "ResponseDecorator requirements not met");
    error_code ec;
    accept_ex(req, decorator, ec);
    if(ec)
        BOOST_THROW_EXCEPTION(system_error{ec});
}

template<class NextLayer, bool deflateSupported>
template<class Body, class Allocator>
void
stream<NextLayer, deflateSupported>::
accept(
    http::request<Body,
        http::basic_fields<Allocator>> const& req,
    error_code& ec)
{
    static_assert(is_sync_stream<next_layer_type>::value,
        "SyncStream requirements not met");
    reset();
    do_accept(req, &default_decorate_res, ec);
}

template<class NextLayer, bool deflateSupported>
template<
    class Body, class Allocator,
    class ResponseDecorator>
void
stream<NextLayer, deflateSupported>::
accept_ex(
    http::request<Body,
        http::basic_fields<Allocator>> const& req,
    ResponseDecorator const& decorator,
    error_code& ec)
{
    static_assert(is_sync_stream<next_layer_type>::value,
        "SyncStream requirements not met");
    static_assert(detail::is_response_decorator<
        ResponseDecorator>::value,
            "ResponseDecorator requirements not met");
    reset();
    do_accept(req, decorator, ec);
}

//------------------------------------------------------------------------------

template<class NextLayer, bool deflateSupported>
template<
    class AcceptHandler>
BOOST_ASIO_INITFN_RESULT_TYPE(
    AcceptHandler, void(error_code))
stream<NextLayer, deflateSupported>::
async_accept(
    AcceptHandler&& handler)
{
    static_assert(is_async_stream<next_layer_type>::value,
        "AsyncStream requirements not met");
    BOOST_BEAST_HANDLER_INIT(
        AcceptHandler, void(error_code));
    reset();
    accept_op<
        decltype(&default_decorate_res),
        BOOST_ASIO_HANDLER_TYPE(
            AcceptHandler, void(error_code))>{
                std::move(init.completion_handler),
                *this,
                &default_decorate_res}({});
    return init.result.get();
}

template<class NextLayer, bool deflateSupported>
template<
    class ResponseDecorator,
    class AcceptHandler>
BOOST_ASIO_INITFN_RESULT_TYPE(
    AcceptHandler, void(error_code))
stream<NextLayer, deflateSupported>::
async_accept_ex(
    ResponseDecorator const& decorator,
    AcceptHandler&& handler)
{
    static_assert(is_async_stream<next_layer_type>::value,
        "AsyncStream requirements not met");
    static_assert(detail::is_response_decorator<
        ResponseDecorator>::value,
            "ResponseDecorator requirements not met");
    BOOST_BEAST_HANDLER_INIT(
        AcceptHandler, void(error_code));
    reset();
    accept_op<
        ResponseDecorator,
        BOOST_ASIO_HANDLER_TYPE(
            AcceptHandler, void(error_code))>{
                std::move(init.completion_handler),
                *this,
                decorator}({});
    return init.result.get();
}

template<class NextLayer, bool deflateSupported>
template<
    class ConstBufferSequence,
    class AcceptHandler>
typename std::enable_if<
    ! http::detail::is_header<ConstBufferSequence>::value,
    BOOST_ASIO_INITFN_RESULT_TYPE(
        AcceptHandler, void(error_code))>::type
stream<NextLayer, deflateSupported>::
async_accept(
    ConstBufferSequence const& buffers,
    AcceptHandler&& handler)
{
    static_assert(is_async_stream<next_layer_type>::value,
        "AsyncStream requirements not met");
    static_assert(net::is_const_buffer_sequence<
        ConstBufferSequence>::value,
            "ConstBufferSequence requirements not met");
    BOOST_BEAST_HANDLER_INIT(
        AcceptHandler, void(error_code));
    reset();
    accept_op<
        decltype(&default_decorate_res),
        BOOST_ASIO_HANDLER_TYPE(
            AcceptHandler, void(error_code))>{
                std::move(init.completion_handler),
                *this,
                &default_decorate_res}.run(buffers);
    return init.result.get();
}

template<class NextLayer, bool deflateSupported>
template<
    class ConstBufferSequence,
    class ResponseDecorator,
    class AcceptHandler>
typename std::enable_if<
    ! http::detail::is_header<ConstBufferSequence>::value,
    BOOST_ASIO_INITFN_RESULT_TYPE(
        AcceptHandler, void(error_code))>::type
stream<NextLayer, deflateSupported>::
async_accept_ex(
    ConstBufferSequence const& buffers,
    ResponseDecorator const& decorator,
    AcceptHandler&& handler)
{
    static_assert(is_async_stream<next_layer_type>::value,
        "AsyncStream requirements not met");
    static_assert(net::is_const_buffer_sequence<
        ConstBufferSequence>::value,
            "ConstBufferSequence requirements not met");
    static_assert(detail::is_response_decorator<
        ResponseDecorator>::value,
            "ResponseDecorator requirements not met");
    BOOST_BEAST_HANDLER_INIT(
        AcceptHandler, void(error_code));
    reset();
    accept_op<
        ResponseDecorator,
        BOOST_ASIO_HANDLER_TYPE(
            AcceptHandler, void(error_code))>{
                std::move(init.completion_handler),
                *this,
                decorator}.run(buffers);
    return init.result.get();
}

template<class NextLayer, bool deflateSupported>
template<
    class Body, class Allocator,
    class AcceptHandler>
BOOST_ASIO_INITFN_RESULT_TYPE(
    AcceptHandler, void(error_code))
stream<NextLayer, deflateSupported>::
async_accept(
    http::request<Body, http::basic_fields<Allocator>> const& req,
    AcceptHandler&& handler)
{
    static_assert(is_async_stream<next_layer_type>::value,
        "AsyncStream requirements not met");
    BOOST_BEAST_HANDLER_INIT(
        AcceptHandler, void(error_code));
    reset();
    using net::asio_handler_is_continuation;
    response_op<
        BOOST_ASIO_HANDLER_TYPE(
            AcceptHandler, void(error_code))>{
                std::move(init.completion_handler),
                *this,
                req,
                &default_decorate_res}();
    return init.result.get();
}

template<class NextLayer, bool deflateSupported>
template<
    class Body, class Allocator,
    class ResponseDecorator,
    class AcceptHandler>
BOOST_ASIO_INITFN_RESULT_TYPE(
    AcceptHandler, void(error_code))
stream<NextLayer, deflateSupported>::
async_accept_ex(
    http::request<Body, http::basic_fields<Allocator>> const& req,
    ResponseDecorator const& decorator,
    AcceptHandler&& handler)
{
    static_assert(is_async_stream<next_layer_type>::value,
        "AsyncStream requirements not met");
    static_assert(detail::is_response_decorator<
        ResponseDecorator>::value,
            "ResponseDecorator requirements not met");
    BOOST_BEAST_HANDLER_INIT(
        AcceptHandler, void(error_code));
    reset();
    using net::asio_handler_is_continuation;
    response_op<
        BOOST_ASIO_HANDLER_TYPE(
            AcceptHandler, void(error_code))>{
                std::move(init.completion_handler),
                *this,
                req,
                decorator}();
    return init.result.get();
}

//------------------------------------------------------------------------------

template<class NextLayer, bool deflateSupported>
template<class Decorator>
void
stream<NextLayer, deflateSupported>::
do_accept(
    Decorator const& decorator,
    error_code& ec)
{
    http::request_parser<http::empty_body> p;
    http::read(next_layer(), rd_buf_, p, ec);
    if(ec == http::error::end_of_stream)
        ec = error::closed;
    if(ec)
        return;
    do_accept(p.get(), decorator, ec);
}

template<class NextLayer, bool deflateSupported>
template<class Body, class Allocator,
    class Decorator>
void
stream<NextLayer, deflateSupported>::
do_accept(
    http::request<Body,
        http::basic_fields<Allocator>> const& req,
    Decorator const& decorator,
    error_code& ec)
{
    error_code result;
    auto const res = build_response(req, decorator, result);
    http::write(stream_, res, ec);
    if(ec)
        return;
    ec = result;
    if(ec)
    {
        // VFALCO TODO Respect keep alive setting, perform
        //             teardown if Connection: close.
        return;
    }
    this->do_pmd_config(res);
    open(role_type::server);
}

} // websocket
} // beast
} // boost

#endif