sources/network/rconsession.cpp

/*
	Copyright 2014, 2015 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 "rconsession.h"
#include "../interface.h"

// -------------------------------------------------------------------------------------------------
//
RCONSession::RCONSession (Interface* iface) :
	m_state (RCON_DISCONNECTED),
	m_lastPing (0),
	m_numAdmins (0),
	m_interface (iface)
{
	if (not m_socket.set_blocking (false))
	{
		print_to (stderr, "unable to set socket as non-blocking: %s\n",
			m_socket.error_string().chars());
		exit (EXIT_FAILURE);
	}
}

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

// -------------------------------------------------------------------------------------------------
//
void RCONSession::connect (IPAddress address)
{
	m_address = address;
	m_state = RCON_CONNECTING;
	m_interface->update_statusbar();
	send_hello();
}

// -------------------------------------------------------------------------------------------------
//
void RCONSession::disconnect()
{
	if (m_state > RCON_CONNECTING)
	{
		// Say goodbye to remote
		Bytestream packet;
		packet.write_byte (CLRC_DISCONNECT);
		this->send (packet);
		m_interface->print ("Disconnected from %1\n", m_address.to_string (IP_WITH_PORT));
		m_interface->update_statusbar();
	}

	m_state = RCON_DISCONNECTED;
}

// -------------------------------------------------------------------------------------------------
//
void RCONSession::send (const Bytestream& packet)
{
	m_socket.send (m_address, packet);
}

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

	time_t now;
	time (&now);

	if (m_lastPing < now)
	{
		if (m_state == RCON_CONNECTING)
		{
			send_hello();
		}
		else if (m_state == RCON_AUTHENTICATING)
		{
			send_password();
		}
		else if (m_state == RCON_CONNECTED and m_lastPing + 5 < now)
		{
			Bytestream packet;
			packet.write_byte (CLRC_PONG);
			send (packet);
			bump_last_ping();
		}
	}

	for (Datagram datagram; m_socket.read (datagram);)
		handle_packet (datagram.data, datagram.from);
}

// -------------------------------------------------------------------------------------------------
//
void RCONSession::handle_packet (Bytestream& packet, const IPAddress& from)
{
	if (from != m_address)
		return;

	try
	{
		while (packet.bytes_left() > 0)
		{
			int header = packet.read_byte();

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

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

			case SVRC_SALT:
				m_salt = packet.read_string();
				m_state = RCON_AUTHENTICATING;
				send_password();
				break;

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

			case SVRC_MESSAGE:
				{
					String message = packet.read_string();
					message.normalize();
					m_interface->print ("%1\n", message);
				}
				break;

			case SVRC_LOGGEDIN:
				m_interface->print ("Login successful!\n");
				m_serverProtocol = packet.read_byte();
				m_hostname = packet.read_string();
				m_interface->set_title (m_hostname);
				m_state = RCON_CONNECTED;

				for (int i = packet.read_byte(); i > 0; --i)
					process_server_updates (packet);

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

				for (int i = packet.read_byte(); i > 0; --i)
				{
					String message = packet.read_string();
					message.normalize();
					m_interface->print ("--- %1\n", message);
				}

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

			case SVRC_UPDATE:
				process_server_updates (packet);
				break;

			case SVRC_TOOMANYTABCOMPLETES:
				{
					unsigned int numCompletions = packet.read_short();
					m_interface->print ("%1 completions for '%2'.\n",
						int (numCompletions), m_lastTabComplete);
				}
				break;

			case SVRC_TABCOMPLETE:
				{
					StringList completes;

					for (signed int i = packet.read_byte(); i > 0; --i)
						completes << packet.read_string();

					if (completes.size() == 1)
					{
						m_interface->tab_complete (m_lastTabComplete, completes[0]);
					}
					else if (not completes.is_empty())
					{
						m_interface->print ("Completions for '%1':\n", m_lastTabComplete);

						for (int i = 0; i < completes.size(); i += 8)
						{
							Range<int> spliceRange (i, min (i + 8, completes.size() - 1));
							StringList splice (completes.splice (spliceRange));
							m_interface->print ("- %1\n", splice.join (", "));
						}
					}
				}
				break;

			case SVRC_WATCHINGCVAR:
				m_interface->print ("Server acknowledges watch on %1\n", packet.read_string());
				m_interface->print ("Its current value is %1\n", packet.read_string());
				break;

			case SVRC_ALREADYWATCHINGCVAR:
				m_interface->print ("Server says you are already watching %1\n", packet.read_string());
				break;

			case SVRC_WATCHCVARNOTFOUND:
				m_interface->print ("No such cvar %1\n", packet.read_string());
				break;

			case SVRC_CVARCHANGED:
				{
					String name = packet.read_string();
					String value = packet.read_string();
					m_interface->print ("New value of %1: %2\n", name, value);
				}
				break;

			case SVRC_YOUREDISCONNECTED:
				{
					String message = packet.read_string();
					m_interface->print_error ("Connection error: %1\n", message);
					m_state = RCON_DISCONNECTED;
					m_interface->disconnected();
				}
				break;
			}
		}
	}
	catch (std::exception& e)
	{
		m_interface->print_warning ("Couldn't process packet: %1\n", e.what());
	}
}

void RCONSession::process_server_updates (Bytestream& packet)
{
	int header = packet.read_byte();

	switch (RCONUpdateType (header))
	{
	case SVRCU_PLAYERDATA:
		{
			StringList players;

			for (int i = packet.read_byte(); i > 0; --i)
				players.append (packet.read_string());

			m_interface->set_player_names (players);
		}
		break;

	case SVRCU_ADMINCOUNT:
		m_numAdmins = packet.read_byte();
		m_interface->update_statusbar();
		break;

	case SVRCU_MAP:
		m_level = packet.read_string();
		m_interface->update_statusbar();
		break;

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

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

// -------------------------------------------------------------------------------------------------
//
void RCONSession::send_hello()
{
	m_interface->print ("Connecting to %1...\n", m_address.to_string (IP_WITH_PORT));
	Bytestream packet;
	packet.write_byte (CLRC_BEGINCONNECTION);
	packet.write_byte (RCON_PROTOCOL_VERSION);
	send (packet);
	bump_last_ping();
}

// -------------------------------------------------------------------------------------------------
//
void RCONSession::send_password()
{
	m_interface->print ("Authenticating...\n");
	Bytestream packet;
	packet.write_byte (CLRC_PASSWORD);
	packet.write_string ((m_salt + m_password).md5());
	send (packet);
	bump_last_ping();
}

// -------------------------------------------------------------------------------------------------
//
void RCONSession::set_password (const String& password)
{
	m_password = password;
}

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

// -------------------------------------------------------------------------------------------------
//
bool RCONSession::is_active() const
{
	return state() != RCON_DISCONNECTED;
}

// -------------------------------------------------------------------------------------------------
// Returns true if the message was successfully sent.
//
bool RCONSession::send_command (const String& message)
{
	if (m_state != RCON_CONNECTED or message.is_empty())
		return false;

	if (message.starts_with ("/watch "))
	{
		String cvarnamelist = message.mid (String ("/watch ").length(), -1);
		cvarnamelist.normalize();

		Bytestream packet;
		packet.write_byte (CLRC_WATCHCVAR);

		for (String cvarname : cvarnamelist.split (' '))
		{
			m_interface->print (TEXTCOLOR_Green "Requesting watch on %1...\n", cvarname);
			packet.write_string (cvarname);
		}
		send (packet);
		bump_last_ping();
		return true;
	}

	Bytestream packet;
	packet.write_byte (CLRC_COMMAND);
	packet.write_string (message);
	send (packet);
	bump_last_ping();
	return true;
}

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

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

// -------------------------------------------------------------------------------------------------
//
int RCONSession::num_admins() const
{
	return m_numAdmins;
}

// -------------------------------------------------------------------------------------------------
//
const String& RCONSession::level() const
{
	return m_level;
}

// -------------------------------------------------------------------------------------------------
//
void RCONSession::request_tab_complete (const String& part)
{
	if (m_serverProtocol >= 4)
	{
		Bytestream packet;
		packet.write_byte (CLRC_TABCOMPLETE);
		packet.write_string (part);
		send (packet);
		bump_last_ping();
		m_lastTabComplete = part;
	}
	else
		m_interface->print ("Server protocol is %1, cannot tab-complete\n", m_serverProtocol);
}