ConnectAttempt.h

//------------------------------------------------------------------------------
/*
    This file is part of rippled: https://github.com/ripple/rippled
    Copyright (c) 2012, 2013 Ripple Labs Inc.
 
    Permission to use, copy, modify, and/or distribute this software for any
    purpose  with  or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.
 
    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
 
#ifndef RIPPLE_OVERLAY_CONNECTATTEMPT_H_INCLUDED
#define RIPPLE_OVERLAY_CONNECTATTEMPT_H_INCLUDED
 
#include <xrpld/overlay/detail/OverlayImpl.h>
 
#include <chrono>
 
namespace ripple {
 
class ConnectAttempt : public OverlayImpl::Child,
                       public std::enable_shared_from_this<ConnectAttempt>
{
private:
    using error_code = boost::system::error_code;
    using endpoint_type = boost::asio::ip::tcp::endpoint;
    using request_type =
        boost::beast::http::request<boost::beast::http::empty_body>;
    using response_type =
        boost::beast::http::response<boost::beast::http::dynamic_body>;
    using socket_type = boost::asio::ip::tcp::socket;
    using middle_type = boost::beast::tcp_stream;
    using stream_type = boost::beast::ssl_stream<middle_type>;
    using shared_context = std::shared_ptr<boost::asio::ssl::context>;
 
    enum class ConnectionStep {
        Init,            // Initial state, nothing started
        TcpConnect,      // Establishing TCP connection to remote peer
        TlsHandshake,    // Performing SSL/TLS handshake
        HttpWrite,       // Sending HTTP upgrade request
        HttpRead,        // Reading HTTP upgrade response
        Complete,        // Connection successfully established
        ShutdownStarted  // Connection shutdown has started
    };
 
    // A timeout for connection process, greater than all step timeouts
    static constexpr std::chrono::seconds connectTimeout{25};
 
    struct StepTimeouts
    {
        // TCP connection timeout
        static constexpr std::chrono::seconds tcpConnect{8};
        // SSL handshake timeout
        static constexpr std::chrono::seconds tlsHandshake{8};
        // HTTP write timeout
        static constexpr std::chrono::seconds httpWrite{3};
        // HTTP read timeout
        static constexpr std::chrono::seconds httpRead{3};
        // SSL shutdown timeout
        static constexpr std::chrono::seconds tlsShutdown{2};
    };
 
    // Core application and networking components
    Application& app_;
    Peer::id_t const id_;
    beast::WrappedSink sink_;
    beast::Journal const journal_;
    endpoint_type remote_endpoint_;
    Resource::Consumer usage_;
 
    boost::asio::strand<boost::asio::io_context::executor_type> strand_;
    boost::asio::basic_waitable_timer<std::chrono::steady_clock> timer_;
    boost::asio::basic_waitable_timer<std::chrono::steady_clock> stepTimer_;
 
    std::unique_ptr<stream_type> stream_ptr_;  // SSL stream (owned)
    socket_type& socket_;
    stream_type& stream_;
    boost::beast::multi_buffer read_buf_;
 
    response_type response_;
    std::shared_ptr<PeerFinder::Slot> slot_;
    request_type req_;
 
    bool shutdown_ = false;   // Shutdown has been initiated
    bool ioPending_ = false;  // Async I/O operation in progress
    ConnectionStep currentStep_ = ConnectionStep::Init;
 
public:
    ConnectAttempt(
        Application& app,
        boost::asio::io_context& io_context,
        endpoint_type const& remote_endpoint,
        Resource::Consumer usage,
        shared_context const& context,
        Peer::id_t id,
        std::shared_ptr<PeerFinder::Slot> const& slot,
        beast::Journal journal,
        OverlayImpl& overlay);
 
    ~ConnectAttempt();
 
    void
    stop() override;
 
    void
    run();
 
private:
    void
    setTimer(ConnectionStep step);
 
    void
    cancelTimer();
 
    void
    onTimer(error_code ec);
 
    // Connection phase handlers
    void
    onConnect(error_code ec);  // TCP connection completion handler
    void
    onHandshake(error_code ec);  // TLS handshake completion handler
    void
    onWrite(error_code ec);  // HTTP write completion handler
    void
    onRead(error_code ec);  // HTTP read completion handler
 
    // Error and cleanup handlers
    void
    fail(std::string const& reason);  // Fail with custom reason
    void
    fail(std::string const& name, error_code ec);  // Fail with system error
    void
    shutdown();  // Initiate graceful shutdown
    void
    tryAsyncShutdown();  // Attempt async SSL shutdown
    void
    onShutdown(error_code ec);  // SSL shutdown completion handler
    void
    close();  // Force close socket
 
    void
    processResponse();
 
    static std::string
    stepToString(ConnectionStep step)
    {
        switch (step)
        {
            case ConnectionStep::Init:
                return "Init";
            case ConnectionStep::TcpConnect:
                return "TcpConnect";
            case ConnectionStep::TlsHandshake:
                return "TlsHandshake";
            case ConnectionStep::HttpWrite:
                return "HttpWrite";
            case ConnectionStep::HttpRead:
                return "HttpRead";
            case ConnectionStep::Complete:
                return "Complete";
            case ConnectionStep::ShutdownStarted:
                return "ShutdownStarted";
        }
        return "Unknown";
    };
 
    template <class = void>
    static boost::asio::ip::tcp::endpoint
    parse_endpoint(std::string const& s, boost::system::error_code& ec)
    {
        beast::IP::Endpoint bep;
        std::istringstream is(s);
        is >> bep;
        if (is.fail())
        {
            ec = boost::system::errc::make_error_code(
                boost::system::errc::invalid_argument);
            return boost::asio::ip::tcp::endpoint{};
        }
 
        return beast::IPAddressConversion::to_asio_endpoint(bep);
    }
};
 
}  // namespace ripple
 
#endif