src/script/cpp_api

/*
Minetest-c55
Copyright (C) 2010 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#ifndef CONNECTION_HEADER
#define CONNECTION_HEADER

#include <iostream>
#include <fstream>
#include "debug.h"
#include "common_irrlicht.h"
#include "socket.h"
#include "utility.h"
#include "exceptions.h"
#include "constants.h"

namespace con
{

/*
	Exceptions
*/
class NotFoundException : public BaseException
{
public:
	NotFoundException(const char *s):
		BaseException(s)
	{}
};

class PeerNotFoundException : public BaseException
{
public:
	PeerNotFoundException(const char *s):
		BaseException(s)
	{}
};

class ConnectionException : public BaseException
{
public:
	ConnectionException(const char *s):
		BaseException(s)
	{}
};

/*class ThrottlingException : public BaseException
{
public:
	ThrottlingException(const char *s):
		BaseException(s)
	{}
};*/

class InvalidIncomingDataException : public BaseException
{
public:
	InvalidIncomingDataException(const char *s):
		BaseException(s)
	{}
};

class InvalidOutgoingDataException : public BaseException
{
public:
	InvalidOutgoingDataException(const char *s):
		BaseException(s)
	{}
};

class NoIncomingDataException : public BaseException
{
public:
	NoIncomingDataException(const char *s):
		BaseException(s)
	{}
};

class ProcessedSilentlyException : public BaseException
{
public:
	ProcessedSilentlyException(const char *s):
		BaseException(s)
	{}
};

class GotSplitPacketException
{
	SharedBuffer<u8> m_data;
public:
	GotSplitPacketException(SharedBuffer<u8> data):
		m_data(data)
	{}
	SharedBuffer<u8> getData()
	{
		return m_data;
	}
};

inline u16 readPeerId(u8 *packetdata)
{
	return readU16(&packetdata[4]);
}
inline u8 readChannel(u8 *packetdata)
{
	return readU8(&packetdata[6]);
}

#define SEQNUM_MAX 65535
inline bool seqnum_higher(u16 higher, u16 lower)
{
	if(lower > higher && lower - higher > SEQNUM_MAX/2){
		return true;
	}
	return (higher > lower);
}

struct BufferedPacket
{
	BufferedPacket(u8 *a_data, u32 a_size):
		data(a_data, a_size), time(0.0), totaltime(0.0)
	{}
	BufferedPacket(u32 a_size):
		data(a_size), time(0.0), totaltime(0.0)
	{}
	SharedBuffer<u8> data; // Data of the packet, including headers
	float time; // Seconds from buffering the packet or re-sending
	float totaltime; // Seconds from buffering the packet
	Address address; // Sender or destination
};

// This adds the base headers to the data and makes a packet out of it
BufferedPacket makePacket(Address &address, u8 *data, u32 datasize,
		u32 protocol_id, u16 sender_peer_id, u8 channel);
BufferedPacket makePacket(Address &address, SharedBuffer<u8> &data,
		u32 protocol_id, u16 sender_peer_id, u8 channel);

// Add the TYPE_ORIGINAL header to the data
SharedBuffer<u8> makeOriginalPacket(
		SharedBuffer<u8> data);

// Split data in chunks and add TYPE_SPLIT headers to them
core::list<SharedBuffer<u8> > makeSplitPacket(
		SharedBuffer<u8> data,
		u32 chunksize_max,
		u16 seqnum);

// Depending on size, make a TYPE_ORIGINAL or TYPE_SPLIT packet
// Increments split_seqnum if a split packet is made
core::list<SharedBuffer<u8> > makeAutoSplitPacket(
		SharedBuffer<u8> data,
		u32 chunksize_max,
		u16 &split_seqnum);

// Add the TYPE_RELIABLE header to the data
SharedBuffer<u8> makeReliablePacket(
		SharedBuffer<u8> data,
		u16 seqnum);

struct IncomingSplitPacket
{
	IncomingSplitPacket()
	{
		time = 0.0;
		reliable = false;
	}
	// Key is chunk number, value is data without headers
	core::map<u16, SharedBuffer<u8> > chunks;
	u32 chunk_count;
	float time; // Seconds from adding
	bool reliable; // If true, isn't deleted on timeout

	bool allReceived()
	{
		return (chunks.size() == chunk_count);
	}
};

/*
=== NOTES ===

A packet is sent through a channel to a peer with a basic header:
TODO: Should we have a receiver_peer_id also?
	Header (7 bytes):
	[0] u32 protocol_id
	[4] u16 sender_peer_id
	[6] u8 channel
sender_peer_id:
	Unique to each peer.
	value 0 is reserved for making new connections
	value 1 is reserved for server
channel:
	The lower the number, the higher the priority is.
	Only channels 0, 1 and 2 exist.
*/
#define BASE_HEADER_SIZE 7
#define PEER_ID_NEW 0
#define PEER_ID_SERVER 1
#define CHANNEL_COUNT 3
/*
Packet types:

CONTROL: This is a packet used by the protocol.
- When this is processed, nothing is handed to the user.
	Header (2 byte):
	[0] u8 type
	[1] u8 controltype
controltype and data description:
	CONTROLTYPE_ACK
		[2] u16 seqnum
	CONTROLTYPE_SET_PEER_ID
		[2] u16 peer_id_new
	CONTROLTYPE_PING
	- There is no actual reply, but this can be sent in a reliable
	  packet to get a reply
	CONTROLTYPE_DISCO
*/
#define TYPE_CONTROL 0
#define CONTROLTYPE_ACK 0
#define CONTROLTYPE_SET_PEER_ID 1
#define CONTROLTYPE_PING 2
#define CONTROLTYPE_DISCO 3
/*
ORIGINAL: This is a plain packet with no control and no error
checking at all.
- When this is processed, it is directly handed to the user.
	Header (1 byte):
	[0] u8 type
*/
#define TYPE_ORIGINAL 1
#define ORIGINAL_HEADER_SIZE 1
/*
SPLIT: These are sequences of packets forming one bigger piece of
data.
- When processed and all the packet_nums 0...packet_count-1 are
  present (this should be buffered), the resulting data shall be
  directly handed to the user.
- If the data fails to come up in a reasonable time, the buffer shall
  be silently discarded.
- These can be sent as-is or atop of a RELIABLE packet stream.
	Header (7 bytes):
	[0] u8 type
	[1] u16 seqnum
	[3] u16 chunk_count
	[5] u16 chunk_num
*/
#define TYPE_SPLIT 2
/*
RELIABLE: Delivery of all RELIABLE packets shall be forced by ACKs,
and they shall be delivered in the same order as sent. This is done
with a buffer in the receiving and transmitting end.
- When this is processed, the contents of each packet is recursively
  processed as packets.
	Header (3 bytes):
	[0] u8 type
	[1] u16 seqnum

*/
#define TYPE_RELIABLE 3
#define RELIABLE_HEADER_SIZE 3
//#define SEQNUM_INITIAL 0x10
#define SEQNUM_INITIAL 65500

/*
Mode	Name	Size
-rw-r--r--	CMakeLists.txt	639	log plain
-rw-r--r--	s_async.cpp	7654	log plain
-rw-r--r--	s_async.h	4184	log plain
-rw-r--r--	s_base.cpp	8783	log plain
-rw-r--r--	s_base.h	3602	log plain
-rw-r--r--	s_client.cpp	5924	log plain
-rw-r--r--	s_client.h	1937	log plain
-rw-r--r--	s_entity.cpp	7994	log plain
-rw-r--r--	s_entity.h	1554	log plain
-rw-r--r--	s_env.cpp	7320	log plain
-rw-r--r--	s_env.h	1505	log plain
-rw-r--r--	s_internal.h	2878	log plain
-rw-r--r--	s_inventory.cpp	7745	log plain
-rw-r--r--	s_inventory.h	2342	log plain
-rw-r--r--	s_item.cpp	7083	log plain
-rw-r--r--	s_item.h	1952	log plain
-rw-r--r--	s_mainmenu.cpp	2660	log plain
-rw-r--r--	s_mainmenu.h	1454	log plain
-rw-r--r--	s_node.cpp	7902	log plain
-rw-r--r--	s_node.h	2016	log plain
-rw-r--r--	s_nodemeta.cpp	8155	log plain
-rw-r--r--	s_nodemeta.h	2220	log plain
-rw-r--r--	s_player.cpp	5481	log plain
-rw-r--r--	s_player.h	1830	log plain
-rw-r--r--	s_security.cpp	17683	log plain
-rw-r--r--	s_security.h	2599	log plain
-rw-r--r--	s_server.cpp	4532	log plain
-rw-r--r--	s_server.h	1559	log plain