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/* $Id$ */
/*
* This file is part of OpenTTD.
* OpenTTD 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, version 2.
* OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file packet.h Basic functions to create, fill and read packets.
*/
#ifndef NETWORK_CORE_PACKET_H
#define NETWORK_CORE_PACKET_H
#include "config.h"
#include "core.h"
#include "../../string_type.h"
#ifdef ENABLE_NETWORK
typedef uint16 PacketSize; ///< Size of the whole packet.
typedef uint8 PacketType; ///< Identifier for the packet
/**
* Internal entity of a packet. As everything is sent as a packet,
* all network communication will need to call the functions that
* populate the packet.
* Every packet can be at most SEND_MTU bytes. Overflowing this
* limit will give an assertion when sending (i.e. writing) the
* packet. Reading past the size of the packet when receiving
* will return all 0 values and "" in case of the string.
*
* --- Points of attention ---
* - all > 1 byte integral values are written in little endian,
* unless specified otherwise.
* Thus, 0x01234567 would be sent as {0x67, 0x45, 0x23, 0x01}.
* - all sent strings are of variable length and terminated by a '\0'.
* Thus, the length of the strings is not sent.
* - years that are leap years in the 'days since X' to 'date' calculations:
* (year % 4 == 0) and ((year % 100 != 0) or (year % 400 == 0))
*/
struct Packet {
/** The next packet. Used for queueing packets before sending. */
Packet *next;
/**
* The size of the whole packet for received packets. For packets
* that will be sent, the value is filled in just before the
* actual transmission.
*/
PacketSize size;
/** The current read/write position in the packet */
PacketSize pos;
/** The buffer of this packet, of basically variable length up to SEND_MTU. */
byte *buffer;
private:
/** Socket we're associated with. */
NetworkSocketHandler *cs;
public:
Packet(NetworkSocketHandler *cs);
Packet(PacketType type);
~Packet();
/* Sending/writing of packets */
void PrepareToSend();
void Send_bool (bool data);
void Send_uint8 (uint8 data);
void Send_uint16(uint16 data);
void Send_uint32(uint32 data);
void Send_uint64(uint64 data);
void Send_string(const char *data);
/* Reading/receiving of packets */
void ReadRawPacketSize();
void PrepareToRead();
bool CanReadFromPacket (uint bytes_to_read);
bool Recv_bool ();
uint8 Recv_uint8 ();
uint16 Recv_uint16();
uint32 Recv_uint32();
uint64 Recv_uint64();
void Recv_string(char *buffer, size_t size, StringValidationSettings settings = SVS_REPLACE_WITH_QUESTION_MARK);
};
#endif /* ENABLE_NETWORK */
#endif /* NETWORK_CORE_PACKET_H */
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