ref: 5d0720d59b521da5686dff85ccfcbf65d79a2b8a
dir: /src/net_sdl.c/
//
// Copyright(C) 2005-2014 Simon Howard
//
// 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.
//
// DESCRIPTION:
// Networking module which uses SDL_net
//
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "doomtype.h"
#include "i_system.h"
#include "m_argv.h"
#include "m_misc.h"
#include "net_defs.h"
#include "net_io.h"
#include "net_packet.h"
#include "net_sdl.h"
#include "z_zone.h"
//
// NETWORKING
//
#include <SDL_net.h>
#define DEFAULT_PORT 2342
static boolean initted = false;
static int port = DEFAULT_PORT;
static UDPsocket udpsocket;
static UDPpacket *recvpacket;
typedef struct
{
net_addr_t net_addr;
IPaddress sdl_addr;
} addrpair_t;
static addrpair_t **addr_table;
static int addr_table_size = -1;
// Initializes the address table
static void NET_SDL_InitAddrTable(void)
{
addr_table_size = 16;
addr_table = Z_Malloc(sizeof(addrpair_t *) * addr_table_size,
PU_STATIC, 0);
memset(addr_table, 0, sizeof(addrpair_t *) * addr_table_size);
}
static boolean AddressesEqual(IPaddress *a, IPaddress *b)
{
return a->host == b->host
&& a->port == b->port;
}
// Finds an address by searching the table. If the address is not found,
// it is added to the table.
static net_addr_t *NET_SDL_FindAddress(IPaddress *addr)
{
addrpair_t *new_entry;
int empty_entry = -1;
int i;
if (addr_table_size < 0)
{
NET_SDL_InitAddrTable();
}
for (i=0; i<addr_table_size; ++i)
{
if (addr_table[i] != NULL
&& AddressesEqual(addr, &addr_table[i]->sdl_addr))
{
return &addr_table[i]->net_addr;
}
if (empty_entry < 0 && addr_table[i] == NULL)
empty_entry = i;
}
// Was not found in list. We need to add it.
// Is there any space in the table? If not, increase the table size
if (empty_entry < 0)
{
addrpair_t **new_addr_table;
int new_addr_table_size;
// after reallocing, we will add this in as the first entry
// in the new block of memory
empty_entry = addr_table_size;
// allocate a new array twice the size, init to 0 and copy
// the existing table in. replace the old table.
new_addr_table_size = addr_table_size * 2;
new_addr_table = Z_Malloc(sizeof(addrpair_t *) * new_addr_table_size,
PU_STATIC, 0);
memset(new_addr_table, 0, sizeof(addrpair_t *) * new_addr_table_size);
memcpy(new_addr_table, addr_table,
sizeof(addrpair_t *) * addr_table_size);
Z_Free(addr_table);
addr_table = new_addr_table;
addr_table_size = new_addr_table_size;
}
// Add a new entry
new_entry = Z_Malloc(sizeof(addrpair_t), PU_STATIC, 0);
new_entry->sdl_addr = *addr;
new_entry->net_addr.refcount = 0;
new_entry->net_addr.handle = &new_entry->sdl_addr;
new_entry->net_addr.module = &net_sdl_module;
addr_table[empty_entry] = new_entry;
return &new_entry->net_addr;
}
static void NET_SDL_FreeAddress(net_addr_t *addr)
{
int i;
for (i=0; i<addr_table_size; ++i)
{
if (addr == &addr_table[i]->net_addr)
{
Z_Free(addr_table[i]);
addr_table[i] = NULL;
return;
}
}
I_Error("NET_SDL_FreeAddress: Attempted to remove an unused address!");
}
static boolean NET_SDL_InitClient(void)
{
int p;
if (initted)
return true;
//!
// @category net
// @arg <n>
//
// Use the specified UDP port for communications, instead of
// the default (2342).
//
p = M_CheckParmWithArgs("-port", 1);
if (p > 0)
port = atoi(myargv[p+1]);
SDLNet_Init();
udpsocket = SDLNet_UDP_Open(0);
if (udpsocket == NULL)
{
I_Error("NET_SDL_InitClient: Unable to open a socket!");
}
recvpacket = SDLNet_AllocPacket(1500);
#ifdef DROP_PACKETS
srand(time(NULL));
#endif
initted = true;
return true;
}
static boolean NET_SDL_InitServer(void)
{
int p;
if (initted)
return true;
p = M_CheckParmWithArgs("-port", 1);
if (p > 0)
port = atoi(myargv[p+1]);
SDLNet_Init();
udpsocket = SDLNet_UDP_Open(port);
if (udpsocket == NULL)
{
I_Error("NET_SDL_InitServer: Unable to bind to port %i", port);
}
recvpacket = SDLNet_AllocPacket(1500);
#ifdef DROP_PACKETS
srand(time(NULL));
#endif
initted = true;
return true;
}
static void NET_SDL_SendPacket(net_addr_t *addr, net_packet_t *packet)
{
UDPpacket sdl_packet;
IPaddress ip;
if (addr == &net_broadcast_addr)
{
SDLNet_ResolveHost(&ip, NULL, port);
ip.host = INADDR_BROADCAST;
}
else
{
ip = *((IPaddress *) addr->handle);
}
#if 0
{
static int this_second_sent = 0;
static int lasttime;
this_second_sent += packet->len + 64;
if (I_GetTime() - lasttime > TICRATE)
{
printf("%i bytes sent in the last second\n", this_second_sent);
lasttime = I_GetTime();
this_second_sent = 0;
}
}
#endif
#ifdef DROP_PACKETS
if ((rand() % 4) == 0)
return;
#endif
sdl_packet.channel = 0;
sdl_packet.data = packet->data;
sdl_packet.len = packet->len;
sdl_packet.address = ip;
if (!SDLNet_UDP_Send(udpsocket, -1, &sdl_packet))
{
I_Error("NET_SDL_SendPacket: Error transmitting packet: %s",
SDLNet_GetError());
}
}
static boolean NET_SDL_RecvPacket(net_addr_t **addr, net_packet_t **packet)
{
int result;
result = SDLNet_UDP_Recv(udpsocket, recvpacket);
if (result < 0)
{
I_Error("NET_SDL_RecvPacket: Error receiving packet: %s",
SDLNet_GetError());
}
// no packets received
if (result == 0)
return false;
// Put the data into a new packet structure
*packet = NET_NewPacket(recvpacket->len);
memcpy((*packet)->data, recvpacket->data, recvpacket->len);
(*packet)->len = recvpacket->len;
// Address
*addr = NET_SDL_FindAddress(&recvpacket->address);
return true;
}
void NET_SDL_AddrToString(net_addr_t *addr, char *buffer, int buffer_len)
{
IPaddress *ip;
uint32_t host;
uint16_t port;
ip = (IPaddress *) addr->handle;
host = SDLNet_Read32(&ip->host);
port = SDLNet_Read16(&ip->port);
M_snprintf(buffer, buffer_len, "%i.%i.%i.%i",
(host >> 24) & 0xff, (host >> 16) & 0xff,
(host >> 8) & 0xff, host & 0xff);
// If we are using the default port we just need to show the IP address,
// but otherwise we need to include the port. This is important because
// we use the string representation in the setup tool to provided an
// address to connect to.
if (port != DEFAULT_PORT)
{
char portbuf[10];
M_snprintf(portbuf, sizeof(portbuf), ":%i", port);
M_StringConcat(buffer, portbuf, buffer_len);
}
}
net_addr_t *NET_SDL_ResolveAddress(const char *address)
{
IPaddress ip;
char *addr_hostname;
int addr_port;
int result;
char *colon;
colon = strchr(address, ':');
addr_hostname = M_StringDuplicate(address);
if (colon != NULL)
{
addr_hostname[colon - address] = '\0';
addr_port = atoi(colon + 1);
}
else
{
addr_port = port;
}
result = SDLNet_ResolveHost(&ip, addr_hostname, addr_port);
free(addr_hostname);
if (result)
{
// unable to resolve
return NULL;
}
else
{
return NET_SDL_FindAddress(&ip);
}
}
// Complete module
net_module_t net_sdl_module =
{
NET_SDL_InitClient,
NET_SDL_InitServer,
NET_SDL_SendPacket,
NET_SDL_RecvPacket,
NET_SDL_AddrToString,
NET_SDL_FreeAddress,
NET_SDL_ResolveAddress,
};