sources/network/rconsession.cpp

/*
	Copyright 2014 - 2021 Teemu Piippo
	All rights reserved.

	Redistribution and use in source and binary forms, with or without
	modification, are permitted provided that the following conditions
	are met:

	1. Redistributions of source code must retain the above copyright
	   notice, this list of conditions and the following disclaimer.
	2. Redistributions in binary form must reproduce the above copyright
	   notice, this list of conditions and the following disclaimer in the
	   documentation and/or other materials provided with the distribution.
	3. Neither the name of the copyright holder nor the names of its
	   contributors may be used to endorse or promote products derived from
	   this software without specific prior written permission.

	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
	TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
	PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER
	OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
	LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
	NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
	SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <time.h>
#include "rconsession.h"
#include "../interface.h"
#include "../md5.h"
BEGIN_ZFC_NAMESPACE

// -------------------------------------------------------------------------------------------------
//
RCONSession::RCONSession() :
	m_state(RCON_DISCONNECTED),
	m_lastPing(0),
	m_adminCount(0),
	m_interface(nullptr)
{
	std::stringstream errors;
	if (not m_socket.set_blocking(false, errors))
	{
		fprintf(stderr, "unable to set socket as non-blocking: %s\n", errors.str().data());
		exit(EXIT_FAILURE);
	}
}

// -------------------------------------------------------------------------------------------------
//
RCONSession::~RCONSession() {}

// -------------------------------------------------------------------------------------------------
//
void RCONSession::connect(net::ip_address address)
{
	this->m_address = address;
	this->m_state = RCON_CONNECTING;
	this->m_interface->updateStatusBar();
	this->tick();
}

// -------------------------------------------------------------------------------------------------
//
void RCONSession::disconnect()
{
	if (m_state > RCON_CONNECTING)
	{
		// Say goodbye to remote
		send({CLRC_DISCONNECT});
		m_interface->disconnected();
	}

	m_state = RCON_DISCONNECTED;
}

// -------------------------------------------------------------------------------------------------
//
bool RCONSession::send(const std::vector<unsigned char>& packet)
{
	std::stringstream errors;
	const bool result = m_socket.send(m_address, packet, errors);
	if (not result)
	{
		this->m_interface->printError("Network error: %s\n", errors.str().data());
	}
	return result;
}

// -------------------------------------------------------------------------------------------------
//
void RCONSession::tick()
{
	if (m_state == RCON_DISCONNECTED)
		return;

	const std::time_t now = std::time(nullptr);

	if (m_lastPing < now)
	{
		// This code block is reached every second
		switch (m_state)
		{
		case RCON_CONNECTING:
			m_interface->print("Connecting to %s...\n", net::ip_address_to_string(m_address).data());
			this->send({CLRC_BEGINCONNECTION, RCON_PROTOCOL_VERSION});
			break;
		case RCON_AUTHENTICATING:
			m_interface->print("Authenticating...\n");
			{
				std::vector<unsigned char> message;
				Bytestream stream(message);
				stream.writeByte(CLRC_PASSWORD);
				stream.writeString(md5((m_salt + m_password).data()));
				this->send(message);
			}
			break;
		case RCON_CONNECTED:
			if (this->m_lastPing + 5 < now)
			{
				this->send({CLRC_PONG});
			}
			break;
		case RCON_DISCONNECTED:
			break;
		}
		this->m_lastPing = now;
	}

	// Check for new packets in our socket
	std::stringstream errors;
	for (net::Datagram datagram; m_socket.read(datagram, errors);)
	{
		if (errors.tellp() > 0)
		{
			m_interface->printError("Network error: %s\n", errors.str().data());
			errors = {};
		}
		// Only process packets that originate from the game server.
		if (datagram.address == m_address)
			handlePacket(datagram.message);
	}
}

// -------------------------------------------------------------------------------------------------
//
void RCONSession::handlePacket(std::vector<unsigned char>& message)
{
	Bytestream stream(message);

	try
	{
		while (stream.bytesLeft() > 0)
		{
			int header = stream.readByte();

			switch (ServerResponse(header))
			{
			case SVRC_OLDPROTOCOL:
				m_interface->printError("Your RCON client is using outdated protocol.\n");
				m_state = RCON_DISCONNECTED;
				break;

			case SVRC_BANNED:
				m_interface->printError("You have been banned from the server.\n");
				m_state = RCON_DISCONNECTED;
				break;

			case SVRC_SALT:
				m_salt = stream.readString();
				m_state = RCON_AUTHENTICATING;
				break;

			case SVRC_INVALIDPASSWORD:
				m_interface->printError("Login failed.\n");
				m_state = RCON_DISCONNECTED;
				break;

			case SVRC_MESSAGE:
				{
					std::string message = stream.readString();
					normalize(message);
					m_interface->printText("%s\n", message.data());
				}
				break;

			case SVRC_LOGGEDIN:
				m_interface->print("Login successful!\n");
				m_serverProtocol = stream.readByte();
				m_hostname = stream.readString();
				m_interface->setTitle(m_hostname);
				m_state = RCON_CONNECTED;

				for (int i = stream.readByte(); i > 0; --i)
					processServerUpdates(stream);

				m_interface->print("Previous messages:\n");

				for (int i = stream.readByte(); i > 0; --i)
				{
					std::string message = stream.readString();
					normalize(message);
					m_interface->printText("--- %s\n", message.data());
				}

				m_interface->print("End of previous messages.\n");
				break;

			case SVRC_UPDATE:
				processServerUpdates(stream);
				break;

			case SVRC_TOOMANYTABCOMPLETES:
				{
					unsigned int numCompletions = stream.readShort();
					m_interface->print("%d completions for '%s'.\n",
						int(numCompletions), m_lastTabComplete.data());
				}
				break;

			case SVRC_TABCOMPLETE:
				{
					std::vector<std::string> completes;
					completes.resize(stream.readByte());

					for (std::string& completion : completes)
						completion = stream.readString();

					if (completes.size() == 1)
					{
						m_interface->tabComplete(m_lastTabComplete, completes[0]);
					}
					else if (completes.size() > 0)
					{
						m_interface->print("Completions for '%s':\n", m_lastTabComplete.data());

						for (std::size_t i = 0; i < completes.size(); i += 8)
						{
							const int end = min(i + 8, completes.size());
							std::vector<std::string> splices = splice(completes, i, end);
							m_interface->print("- %s\n", join_string_list(splices, ", ").data());
						}
					}
				}
				break;
			}
		}
	}
	catch (std::exception& e)
	{
		m_interface->printWarning("Couldn't process packet: %s\n", e.what());
		m_interface->printWarning("Packet contents was: %s\n", quote(message).data());
		m_interface->printWarning("Stream position in payload was: %d\n", stream.position());
	}
}

void RCONSession::processServerUpdates(Bytestream& packet)
{
	int header = packet.readByte();

	switch (RCONUpdateType(header))
	{
	case SVRCU_PLAYERDATA:
		{
			std::vector<std::string> players;

			for (int i = packet.readByte(); i > 0; --i)
				players.push_back(packet.readString());

			m_interface->setPlayerNames(players);
		}
		break;

	case SVRCU_ADMINCOUNT:
		m_adminCount = packet.readByte();
		m_interface->updateStatusBar();
		break;

	case SVRCU_MAP:
		m_level = packet.readString();
		m_interface->updateStatusBar();
		break;

	default:
		m_interface->printWarning("Unknown server update type: %d\n", header);
		break;
	}
}

// -------------------------------------------------------------------------------------------------
//
net::UDPSocket* RCONSession::getSocket()
{
	return &m_socket;
}

// -------------------------------------------------------------------------------------------------
//
void RCONSession::setPassword(const std::string& password)
{
	m_password = password;
}

// -------------------------------------------------------------------------------------------------
//
void RCONSession::bumpLastPing()
{
	time_t now;
	time(&now);
	m_lastPing = now;
}

// -------------------------------------------------------------------------------------------------
//
bool RCONSession::isActive() const
{
	return getState() != RCON_DISCONNECTED;
}

// -------------------------------------------------------------------------------------------------
// Returns true if the message was successfully sent.
//
bool RCONSession::sendCommand(const std::string& commandString)
{
	if (m_state != RCON_CONNECTED or commandString.empty())
		return false;

	std::vector<unsigned char> message;
	Bytestream stream(message);
	stream.writeByte(CLRC_COMMAND);
	stream.writeString(commandString);
	send(message);
	return true;
}

// -------------------------------------------------------------------------------------------------
//
RCONSessionState RCONSession::getState() const
{
	return m_state;
}

// -------------------------------------------------------------------------------------------------
//
const net::ip_address& RCONSession::address() const
{
	return m_address;
}

// -------------------------------------------------------------------------------------------------
//
int RCONSession::getAdminCount() const
{
	return m_adminCount;
}

// -------------------------------------------------------------------------------------------------
//
const std::string& RCONSession::getLevel() const
{
	return m_level;
}

// -------------------------------------------------------------------------------------------------
//
void RCONSession::requestTabCompletion(const std::string& part)
{
	if (m_serverProtocol >= 4)
	{
		std::vector<unsigned char> message;
		Bytestream stream(message);
		stream.writeByte(CLRC_TABCOMPLETE);
		stream.writeString(part);
		send(message);
		m_lastTabComplete = part;
	}
	else
	{
		m_interface->print("This server does not support tab-completion\n");
	}
}

// -------------------------------------------------------------------------------------------------
//
void RCONSession::setInterface(Interface* interface)
{
	m_interface = interface;
}

END_ZFC_NAMESPACE