static void NET_SV_ParseSYN(net_packet_t *packet, net_client_t *client, net_addr_t *addr) { unsigned int magic; net_connect_data_t data; char *player_name; char *client_version; int i; // read the magic number if (!NET_ReadInt32(packet, &magic)) { return; } if (magic != NET_MAGIC_NUMBER) { // invalid magic number return; } // Check the client version is the same as the server client_version = NET_ReadString(packet); if (client_version == NULL) { return; } // [crispy] allow Chocolate Doom 2.2.0 clients to connect to Crispy Doom servers if (strcmp(client_version, PACKAGE_STRING) != 0 && strcmp(client_version, "Chocolate Doom 2.2.0") != 0) { //! // @category net // // When running a netgame server, ignore version mismatches between // the server and the client. Using this option may cause game // desyncs to occur, or differences in protocol may mean the netgame // will simply not function at all. // if (M_CheckParm("-ignoreversion") == 0) { NET_SV_SendReject(addr, "Different " PACKAGE_NAME " versions cannot play a net game!\n" "Version mismatch: server version is: " PACKAGE_STRING); return; } } // read the game mode and mission if (!NET_ReadConnectData(packet, &data)) { return; } if (!D_ValidGameMode(data.gamemission, data.gamemode)) { return; } // Check max_players value. This must be in a sensible range. if (data.max_players > NET_MAXPLAYERS) { return; } // read the player's name player_name = NET_ReadString(packet); if (player_name == NULL) { return; } // received a valid SYN // not accepting new connections? if (server_state != SERVER_WAITING_LAUNCH) { NET_SV_SendReject(addr, "Server is not currently accepting connections"); return; } // allocate a client slot if there isn't one already if (client == NULL) { // find a slot, or return if none found for (i=0; i<MAXNETNODES; ++i) { if (!clients[i].active) { client = &clients[i]; break; } } if (client == NULL) { return; } } else { // If this is a recently-disconnected client, deactivate // to allow immediate reconnection if (client->connection.state == NET_CONN_STATE_DISCONNECTED) { client->active = false; } } // New client? if (!client->active) { int num_players; // Before accepting a new client, check that there is a slot // free NET_SV_AssignPlayers(); num_players = NET_SV_NumPlayers(); if ((!data.drone && num_players >= NET_SV_MaxPlayers()) || NET_SV_NumClients() >= MAXNETNODES) { NET_SV_SendReject(addr, "Server is full!"); return; } // TODO: Add server option to allow rejecting clients which // set lowres_turn. This is potentially desirable as the // presence of such clients affects turning resolution. // Adopt the game mode and mission of the first connecting client if (num_players == 0 && !data.drone) { sv_gamemode = data.gamemode; sv_gamemission = data.gamemission; } // Save the SHA1 checksums memcpy(client->wad_sha1sum, data.wad_sha1sum, sizeof(sha1_digest_t)); memcpy(client->deh_sha1sum, data.deh_sha1sum, sizeof(sha1_digest_t)); client->is_freedoom = data.is_freedoom; client->max_players = data.max_players; // Check the connecting client is playing the same game as all // the other clients if (data.gamemode != sv_gamemode || data.gamemission != sv_gamemission) { NET_SV_SendReject(addr, "You are playing the wrong game!"); return; } // Activate, initialize connection NET_SV_InitNewClient(client, addr, player_name); client->recording_lowres = data.lowres_turn; client->drone = data.drone; client->player_class = data.player_class; } if (client->connection.state == NET_CONN_STATE_WAITING_ACK) { // force an acknowledgement client->connection.last_send_time = -1; } }
static void NET_SV_ParseSYN(net_packet_t *packet, net_client_t *client, net_addr_t *addr) { unsigned int magic; net_connect_data_t data; net_packet_t *reply; net_protocol_t protocol; char *player_name; char *client_version; int num_players; int i; NET_Log("server: processing SYN packet"); // Read the magic number and check it is the expected one. if (!NET_ReadInt32(packet, &magic)) { NET_Log("server: error: no magic number for SYN"); return; } switch (magic) { case NET_MAGIC_NUMBER: break; case NET_OLD_MAGIC_NUMBER: NET_Log("server: error: client using old magic number: %d", magic); NET_SV_SendReject(addr, "You are using an old client version that is not supported by " "this server. This server is running " PACKAGE_STRING "."); return; default: NET_Log("server: error: wrong magic number: %d", magic); return; } // Read the client version string. We actually now only use this when // sending a reject message, as we only reject if we can't negotiate a // common protocol (below). client_version = NET_ReadString(packet); if (client_version == NULL) { NET_Log("server: error: no version from client"); return; } // Read the client's list of accepted protocols. Net play between forks // of Chocolate Doom is accepted provided that they can negotiate a // common accepted protocol. protocol = NET_ReadProtocolList(packet); if (protocol == NET_PROTOCOL_UNKNOWN) { char reject_msg[256]; M_snprintf(reject_msg, sizeof(reject_msg), "Version mismatch: server version is: " PACKAGE_STRING "; " "client is: %s. No common compatible protocol could be " "negotiated.", client_version); NET_SV_SendReject(addr, reject_msg); NET_Log("server: error: no common protocol"); return; } // Read connect data, and check that the game mode/mission are valid // and the max_players value is in a sensible range. if (!NET_ReadConnectData(packet, &data)) { NET_Log("server: error: failed to read connect data"); return; } if (!D_ValidGameMode(data.gamemission, data.gamemode) || data.max_players > NET_MAXPLAYERS) { NET_Log("server: error: invalid connect data, max_players=%d, " "gamemission=%d, gamemode=%d", data.max_players, data.gamemission, data.gamemode); return; } // Read the player's name player_name = NET_ReadString(packet); if (player_name == NULL) { NET_Log("server: error: failed to read player name"); return; } // At this point we have received a valid SYN. // Not accepting new connections? if (server_state != SERVER_WAITING_LAUNCH) { NET_Log("server: error: not in waiting launch state, server_state=%d", server_state); NET_SV_SendReject(addr, "Server is not currently accepting connections"); return; } // Before accepting a new client, check that there is a slot free. NET_SV_AssignPlayers(); num_players = NET_SV_NumPlayers(); if ((!data.drone && num_players >= NET_SV_MaxPlayers()) || NET_SV_NumClients() >= MAXNETNODES) { NET_Log("server: no more players, num_players=%d, max=%d", num_players, NET_SV_MaxPlayers()); NET_SV_SendReject(addr, "Server is full!"); return; } // TODO: Add server option to allow rejecting clients which set // lowres_turn. This is potentially desirable as the presence of such // clients affects turning resolution. // Adopt the game mode and mission of the first connecting client: if (num_players == 0 && !data.drone) { sv_gamemode = data.gamemode; sv_gamemission = data.gamemission; NET_Log("server: new game, mode=%d, mission=%d", sv_gamemode, sv_gamemission); } // Check the connecting client is playing the same game as all // the other clients if (data.gamemode != sv_gamemode || data.gamemission != sv_gamemission) { char msg[128]; NET_Log("server: wrong mode/mission, %d != %d || %d != %d", data.gamemode, sv_gamemode, data.gamemission, sv_gamemission); M_snprintf(msg, sizeof(msg), "Game mismatch: server is %s (%s), client is %s (%s)", D_GameMissionString(sv_gamemission), D_GameModeString(sv_gamemode), D_GameMissionString(data.gamemission), D_GameModeString(data.gamemode)); NET_SV_SendReject(addr, msg); return; } // Allocate a client slot if there isn't one already if (client == NULL) { // find a slot, or return if none found for (i=0; i<MAXNETNODES; ++i) { if (!clients[i].active) { client = &clients[i]; break; } } if (client == NULL) { return; } } else { // If this is a recently-disconnected client, deactivate // to allow immediate reconnection if (client->connection.state == NET_CONN_STATE_DISCONNECTED) { client->active = false; } } // Client already connected? if (client->active) { NET_Log("server: client is already initialized (duplicate SYN?)"); return; } // Activate, initialize connection NET_SV_InitNewClient(client, addr, protocol); // Save the SHA1 checksums and other details. memcpy(client->wad_sha1sum, data.wad_sha1sum, sizeof(sha1_digest_t)); memcpy(client->deh_sha1sum, data.deh_sha1sum, sizeof(sha1_digest_t)); client->is_freedoom = data.is_freedoom; client->max_players = data.max_players; client->name = M_StringDuplicate(player_name); client->recording_lowres = data.lowres_turn; client->drone = data.drone; client->player_class = data.player_class; // Send a reply back to the client, indicating a successful connection // and specifying the protocol that will be used for communications. reply = NET_Conn_NewReliable(&client->connection, NET_PACKET_TYPE_SYN); NET_WriteString(reply, PACKAGE_STRING); NET_WriteProtocol(reply, protocol); }