ref: 96a017b56ff4d8a7db6a4a6179f6239a38ccdd18
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.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(char *address) { IPaddress ip; char *addr_hostname; int addr_port; int result; char *colon; colon = strchr(address, ':'); if (colon != NULL) { addr_hostname = M_StringDuplicate(address); addr_hostname[colon - address] = '\0'; addr_port = atoi(colon + 1); } else { addr_hostname = address; addr_port = port; } result = SDLNet_ResolveHost(&ip, addr_hostname, addr_port); if (addr_hostname != address) { 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, };