SFML/src/SFML/Network/TcpSocket.cpp
2014-02-06 20:08:26 +01:00

382 lines
12 KiB
C++

////////////////////////////////////////////////////////////
//
// SFML - Simple and Fast Multimedia Library
// Copyright (C) 2007-2014 Laurent Gomila (laurent.gom@gmail.com)
//
// This software is provided 'as-is', without any express or implied warranty.
// In no event will the authors be held liable for any damages arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it freely,
// subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented;
// you must not claim that you wrote the original software.
// If you use this software in a product, an acknowledgment
// in the product documentation would be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such,
// and must not be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////
// Headers
////////////////////////////////////////////////////////////
#include <SFML/Network/TcpSocket.hpp>
#include <SFML/Network/IpAddress.hpp>
#include <SFML/Network/Packet.hpp>
#include <SFML/Network/SocketImpl.hpp>
#include <SFML/System/Err.hpp>
#include <algorithm>
#include <cstring>
#ifdef _MSC_VER
#pragma warning(disable : 4127) // "conditional expression is constant" generated by the FD_SET macro
#endif
namespace
{
// Define the low-level send/receive flags, which depend on the OS
#ifdef SFML_SYSTEM_LINUX
const int flags = MSG_NOSIGNAL;
#else
const int flags = 0;
#endif
}
namespace sf
{
////////////////////////////////////////////////////////////
TcpSocket::TcpSocket() :
Socket(Tcp)
{
}
////////////////////////////////////////////////////////////
unsigned short TcpSocket::getLocalPort() const
{
if (getHandle() != priv::SocketImpl::invalidSocket())
{
// Retrieve informations about the local end of the socket
sockaddr_in address;
priv::SocketImpl::AddrLength size = sizeof(address);
if (getsockname(getHandle(), reinterpret_cast<sockaddr*>(&address), &size) != -1)
{
return ntohs(address.sin_port);
}
}
// We failed to retrieve the port
return 0;
}
////////////////////////////////////////////////////////////
IpAddress TcpSocket::getRemoteAddress() const
{
if (getHandle() != priv::SocketImpl::invalidSocket())
{
// Retrieve informations about the remote end of the socket
sockaddr_in address;
priv::SocketImpl::AddrLength size = sizeof(address);
if (getpeername(getHandle(), reinterpret_cast<sockaddr*>(&address), &size) != -1)
{
return IpAddress(ntohl(address.sin_addr.s_addr));
}
}
// We failed to retrieve the address
return IpAddress::None;
}
////////////////////////////////////////////////////////////
unsigned short TcpSocket::getRemotePort() const
{
if (getHandle() != priv::SocketImpl::invalidSocket())
{
// Retrieve informations about the remote end of the socket
sockaddr_in address;
priv::SocketImpl::AddrLength size = sizeof(address);
if (getpeername(getHandle(), reinterpret_cast<sockaddr*>(&address), &size) != -1)
{
return ntohs(address.sin_port);
}
}
// We failed to retrieve the port
return 0;
}
////////////////////////////////////////////////////////////
Socket::Status TcpSocket::connect(const IpAddress& remoteAddress, unsigned short remotePort, Time timeout)
{
// Create the internal socket if it doesn't exist
create();
// Create the remote address
sockaddr_in address = priv::SocketImpl::createAddress(remoteAddress.toInteger(), remotePort);
if (timeout <= Time::Zero)
{
// ----- We're not using a timeout: just try to connect -----
// Connect the socket
if (::connect(getHandle(), reinterpret_cast<sockaddr*>(&address), sizeof(address)) == -1)
return priv::SocketImpl::getErrorStatus();
// Connection succeeded
return Done;
}
else
{
// ----- We're using a timeout: we'll need a few tricks to make it work -----
// Save the previous blocking state
bool blocking = isBlocking();
// Switch to non-blocking to enable our connection timeout
if (blocking)
setBlocking(false);
// Try to connect to the remote address
if (::connect(getHandle(), reinterpret_cast<sockaddr*>(&address), sizeof(address)) >= 0)
{
// We got instantly connected! (it may no happen a lot...)
setBlocking(blocking);
return Done;
}
// Get the error status
Status status = priv::SocketImpl::getErrorStatus();
// If we were in non-blocking mode, return immediatly
if (!blocking)
return status;
// Otherwise, wait until something happens to our socket (success, timeout or error)
if (status == Socket::NotReady)
{
// Setup the selector
fd_set selector;
FD_ZERO(&selector);
FD_SET(getHandle(), &selector);
// Setup the timeout
timeval time;
time.tv_sec = static_cast<long>(timeout.asMicroseconds() / 1000000);
time.tv_usec = static_cast<long>(timeout.asMicroseconds() % 1000000);
// Wait for something to write on our socket (which means that the connection request has returned)
if (select(static_cast<int>(getHandle() + 1), NULL, &selector, NULL, &time) > 0)
{
// At this point the connection may have been either accepted or refused.
// To know whether it's a success or a failure, we must check the address of the connected peer
if (getRemoteAddress() != sf::IpAddress::None)
{
// Connection accepted
status = Done;
}
else
{
// Connection refused
status = priv::SocketImpl::getErrorStatus();
}
}
else
{
// Failed to connect before timeout is over
status = priv::SocketImpl::getErrorStatus();
}
}
// Switch back to blocking mode
setBlocking(true);
return status;
}
}
////////////////////////////////////////////////////////////
void TcpSocket::disconnect()
{
// Close the socket
close();
// Reset the pending packet data
m_pendingPacket = PendingPacket();
}
////////////////////////////////////////////////////////////
Socket::Status TcpSocket::send(const void* data, std::size_t size)
{
// Check the parameters
if (!data || (size == 0))
{
err() << "Cannot send data over the network (no data to send)" << std::endl;
return Error;
}
// Loop until every byte has been sent
int sent = 0;
int sizeToSend = static_cast<int>(size);
for (int length = 0; length < sizeToSend; length += sent)
{
// Send a chunk of data
sent = ::send(getHandle(), static_cast<const char*>(data) + length, sizeToSend - length, flags);
// Check for errors
if (sent < 0)
return priv::SocketImpl::getErrorStatus();
}
return Done;
}
////////////////////////////////////////////////////////////
Socket::Status TcpSocket::receive(void* data, std::size_t size, std::size_t& received)
{
// First clear the variables to fill
received = 0;
// Check the destination buffer
if (!data)
{
err() << "Cannot receive data from the network (the destination buffer is invalid)" << std::endl;
return Error;
}
// Receive a chunk of bytes
int sizeReceived = recv(getHandle(), static_cast<char*>(data), static_cast<int>(size), flags);
// Check the number of bytes received
if (sizeReceived > 0)
{
received = static_cast<std::size_t>(sizeReceived);
return Done;
}
else if (sizeReceived == 0)
{
return Socket::Disconnected;
}
else
{
return priv::SocketImpl::getErrorStatus();
}
}
////////////////////////////////////////////////////////////
Socket::Status TcpSocket::send(Packet& packet)
{
// TCP is a stream protocol, it doesn't preserve messages boundaries.
// This means that we have to send the packet size first, so that the
// receiver knows the actual end of the packet in the data stream.
// We allocate an extra memory block so that the size can be sent
// together with the data in a single call. This may seem inefficient,
// but it is actually required to avoid partial send, which could cause
// data corruption on the receiving end.
// Get the data to send from the packet
std::size_t size = 0;
const void* data = packet.onSend(size);
// First convert the packet size to network byte order
Uint32 packetSize = htonl(static_cast<Uint32>(size));
// Allocate memory for the data block to send
std::vector<char> blockToSend(sizeof(packetSize) + size);
// Copy the packet size and data into the block to send
std::memcpy(&blockToSend[0], &packetSize, sizeof(packetSize));
if (size > 0)
std::memcpy(&blockToSend[0] + sizeof(packetSize), data, size);
// Send the data block
return send(&blockToSend[0], blockToSend.size());
}
////////////////////////////////////////////////////////////
Socket::Status TcpSocket::receive(Packet& packet)
{
// First clear the variables to fill
packet.clear();
// We start by getting the size of the incoming packet
Uint32 packetSize = 0;
std::size_t received = 0;
if (m_pendingPacket.SizeReceived < sizeof(m_pendingPacket.Size))
{
// Loop until we've received the entire size of the packet
// (even a 4 byte variable may be received in more than one call)
while (m_pendingPacket.SizeReceived < sizeof(m_pendingPacket.Size))
{
char* data = reinterpret_cast<char*>(&m_pendingPacket.Size) + m_pendingPacket.SizeReceived;
Status status = receive(data, sizeof(m_pendingPacket.Size) - m_pendingPacket.SizeReceived, received);
m_pendingPacket.SizeReceived += received;
if (status != Done)
return status;
}
// The packet size has been fully received
packetSize = ntohl(m_pendingPacket.Size);
}
else
{
// The packet size has already been received in a previous call
packetSize = ntohl(m_pendingPacket.Size);
}
// Loop until we receive all the packet data
char buffer[1024];
while (m_pendingPacket.Data.size() < packetSize)
{
// Receive a chunk of data
std::size_t sizeToGet = std::min(static_cast<std::size_t>(packetSize - m_pendingPacket.Data.size()), sizeof(buffer));
Status status = receive(buffer, sizeToGet, received);
if (status != Done)
return status;
// Append it into the packet
if (received > 0)
{
m_pendingPacket.Data.resize(m_pendingPacket.Data.size() + received);
char* begin = &m_pendingPacket.Data[0] + m_pendingPacket.Data.size() - received;
std::memcpy(begin, buffer, received);
}
}
// We have received all the packet data: we can copy it to the user packet
if (!m_pendingPacket.Data.empty())
packet.onReceive(&m_pendingPacket.Data[0], m_pendingPacket.Data.size());
// Clear the pending packet data
m_pendingPacket = PendingPacket();
return Done;
}
////////////////////////////////////////////////////////////
TcpSocket::PendingPacket::PendingPacket() :
Size (0),
SizeReceived(0),
Data ()
{
}
} // namespace sf