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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
#ifndef INCLUDED_LOOLWEBSOCKET_HPP
#define INCLUDED_LOOLWEBSOCKET_HPP
#include <cstdlib>
#include <mutex>
#include <thread>
#include <Poco/Net/WebSocket.h>
#include <Common.hpp>
#include <Protocol.hpp>
#include <Log.hpp>
/// WebSocket that is thread safe, and handles large frames transparently.
/// Careful - sendFrame and receiveFrame are _not_ virtual,
/// we need to make sure that we use LOOLWebSocket all over the place.
/// It would be a kind of more natural to encapsulate Poco::Net::WebSocket
/// instead of inheriting (from that reason,) but that would requite much
/// larger code changes.
class LOOLWebSocket : public Poco::Net::WebSocket
{
private:
std::mutex _mutexRead;
std::mutex _mutexWrite;
#if ENABLE_DEBUG
static std::chrono::milliseconds getWebSocketDelay()
{
unsigned long baseDelay = 0;
unsigned long jitter = 0;
if (std::getenv("LOOL_WS_DELAY"))
{
baseDelay = std::stoul(std::getenv("LOOL_WS_DELAY"));
}
if (std::getenv("LOOL_WS_JITTER"))
{
jitter = std::stoul(std::getenv("LOOL_WS_JITTER"));
}
return std::chrono::milliseconds(baseDelay + (jitter > 0 ? (std::rand() % jitter) : 0));
}
void setMinSocketBufferSize()
{
// Lets set it to zero as system will automatically adjust it to minimum
setSendBufferSize(0);
LOG_INF("Send buffer size for web socket set to minimum: " << getSendBufferSize());
}
#endif
public:
LOOLWebSocket(const Socket& socket) :
Poco::Net::WebSocket(socket)
{
}
LOOLWebSocket(Poco::Net::HTTPServerRequest& request,
Poco::Net::HTTPServerResponse& response) :
Poco::Net::WebSocket(request, response)
{
#if ENABLE_DEBUG
setMinSocketBufferSize();
#endif
}
LOOLWebSocket(Poco::Net::HTTPClientSession& cs,
Poco::Net::HTTPRequest& request,
Poco::Net::HTTPResponse& response) :
Poco::Net::WebSocket(cs, request, response)
{
#if ENABLE_DEBUG
setMinSocketBufferSize();
#endif
}
LOOLWebSocket(Poco::Net::HTTPClientSession& cs,
Poco::Net::HTTPRequest& request,
Poco::Net::HTTPResponse& response,
Poco::Net::HTTPCredentials& credentials) :
Poco::Net::WebSocket(cs, request, response, credentials)
{
#if ENABLE_DEBUG
setMinSocketBufferSize();
#endif
}
/// Wrapper for Poco::Net::WebSocket::receiveFrame() that handles PING frames
/// (by replying with a PONG frame) and PONG frames. PONG frames are ignored.
/// Returns number of bytes received, or 0 if the Poco receiveFrame() returned 0,
/// or -1 if no "interesting" (not PING or PONG) frame was actually received).
/// Should we also factor out the handling of non-final and continuation frames into this?
int receiveFrame(char* buffer, const int length, int& flags)
{
#if ENABLE_DEBUG
// Delay receiving the frame
std::this_thread::sleep_for(getWebSocketDelay());
#endif
// Timeout is in microseconds. We don't need this, except to yield the cpu.
static const Poco::Timespan waitTime(POLL_TIMEOUT_MS * 1000 / 10);
static const Poco::Timespan waitZero(0);
while (poll(waitTime, Poco::Net::Socket::SELECT_READ))
{
std::unique_lock<std::mutex> lockRead(_mutexRead);
const int n = Poco::Net::WebSocket::receiveFrame(buffer, length, flags);
lockRead.unlock();
if (n <= 0)
LOG_TRC("Got nothing (" << n << ")");
else
LOG_TRC("Got frame: " << LOOLProtocol::getAbbreviatedFrameDump(buffer, n, flags));
if ((flags & WebSocket::FRAME_OP_BITMASK) == WebSocket::FRAME_OP_CLOSE)
{
// Nothing to do.
return n;
}
if ((flags & WebSocket::FRAME_OP_BITMASK) == WebSocket::FRAME_OP_PING)
{
// Echo back the ping message.
std::unique_lock<std::mutex> lock(_mutexWrite);
if (Poco::Net::WebSocket::sendFrame(buffer, n, static_cast<int>(WebSocket::FRAME_FLAG_FIN) | WebSocket::FRAME_OP_PONG) != n)
{
LOG_WRN("Sending Pong failed.");
return -1;
}
}
else if ((flags & WebSocket::FRAME_OP_BITMASK) == WebSocket::FRAME_OP_PONG)
{
// In case we do send pings in the future.
}
else
{
return n;
}
}
// Not ready for read.
return -1;
}
/// Wrapper for Poco::Net::WebSocket::sendFrame() that handles large frames.
int sendFrame(const char* buffer, const int length, const int flags = FRAME_TEXT)
{
#if ENABLE_DEBUG
// Delay sending the frame
std::this_thread::sleep_for(getWebSocketDelay());
#endif
static const Poco::Timespan waitZero(0);
std::unique_lock<std::mutex> lock(_mutexWrite);
const int result = Poco::Net::WebSocket::sendFrame(buffer, length, flags);
lock.unlock();
if (result != length)
{
LOG_ERR("Sent incomplete message, expected " << length << " bytes but sent " << result <<
" for: " << LOOLProtocol::getAbbreviatedFrameDump(buffer, length, flags));
}
else
{
LOG_TRC("Sent frame: " << LOOLProtocol::getAbbreviatedFrameDump(buffer, length, flags));
}
return result;
}
/// Safe shutdown by sending a normal close frame, if socket is not in error,
/// or, otherwise, close the socket without sending close frame, if it is.
void shutdown()
{
shutdown(Poco::Net::WebSocket::StatusCodes::WS_NORMAL_CLOSE);
}
/// Safe shutdown by sending a specific close frame, if socket is not in error,
/// or, otherwise, close the socket without sending close frame, if it is.
void shutdown(Poco::UInt16 statusCode, const std::string& statusMessage = "")
{
std::unique_lock<std::mutex> lockRead(_mutexRead);
std::unique_lock<std::mutex> lockWrite(_mutexWrite);
try
{
// Calling shutdown, in case of error, would try to send a 'close' frame
// which won't work in case of broken pipe or timeout from peer. Just close the
// socket in that case preventing 'close' frame from being sent.
if (Poco::Net::WebSocket::poll(Poco::Timespan(0), Socket::SelectMode::SELECT_ERROR))
{
Poco::Net::WebSocket::close();
}
else
{
Poco::Net::WebSocket::shutdown(statusCode, statusMessage);
}
}
catch (const Poco::Exception& exc)
{
LOG_WRN("LOOLWebSocket::shutdown: Exception: " << exc.displayText() <<
(exc.nested() ? " (" + exc.nested()->displayText() + ")" : ""));
// Just close it.
try
{
Poco::Net::WebSocket::close();
}
catch (const std::exception&)
{
// Nothing we can do.
}
}
}
};
#endif
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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