ref: 2053768a9251cbd4c731681a3e1e04c800ad21f4
dir: /src/net_server.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.
//
// Network server code
//
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include "config.h"
#include "doomtype.h"
#include "d_mode.h"
#include "i_system.h"
#include "i_timer.h"
#include "m_argv.h"
#include "m_misc.h"
#include "net_client.h"
#include "net_common.h"
#include "net_defs.h"
#include "net_io.h"
#include "net_loop.h"
#include "net_packet.h"
#include "net_query.h"
#include "net_server.h"
#include "net_sdl.h"
#include "net_structrw.h"
// How often to refresh our registration with the master server.
#define MASTER_REFRESH_PERIOD 30 /* twice per minute */
// How often to re-resolve the address of the master server?
#define MASTER_RESOLVE_PERIOD 8 * 60 * 60 /* 8 hours */
typedef enum
{
// waiting for the game to be "launched" (key player to press the start
// button)
SERVER_WAITING_LAUNCH,
// game has been launched, we are waiting for all players to be ready
// so the game can start.
SERVER_WAITING_START,
// in a game
SERVER_IN_GAME,
} net_server_state_t;
typedef struct
{
boolean active;
int player_number;
net_addr_t *addr;
net_connection_t connection;
int last_send_time;
char *name;
// If true, the client has sent the NET_PACKET_TYPE_GAMESTART
// message indicating that it is ready for the game to start.
boolean ready;
// Time that this client connected to the server.
// This is used to determine the controller (oldest client).
unsigned int connect_time;
// Last time new gamedata was received from this client
int last_gamedata_time;
// recording a demo without -longtics
boolean recording_lowres;
// send queue: items to send to the client
// this is a circular buffer
int sendseq;
net_full_ticcmd_t sendqueue[BACKUPTICS];
// Latest acknowledged by the client
unsigned int acknowledged;
// Value of max_players specified by the client on connect.
int max_players;
// Observer: receives data but does not participate in the game.
boolean drone;
// SHA1 hash sums of the client's WAD directory and dehacked data
sha1_digest_t wad_sha1sum;
sha1_digest_t deh_sha1sum;
// Is this client is playing with the Freedoom IWAD?
unsigned int is_freedoom;
// Player class (for Hexen)
int player_class;
} net_client_t;
// structure used for the recv window
typedef struct
{
// Whether this tic has been received yet
boolean active;
// Latency value received from the client
signed int latency;
// Last time we sent a resend request for this tic
unsigned int resend_time;
// Tic data itself
net_ticdiff_t diff;
} net_client_recv_t;
static net_server_state_t server_state;
static boolean server_initialized = false;
static net_client_t clients[MAXNETNODES];
static net_client_t *sv_players[NET_MAXPLAYERS];
static net_context_t *server_context;
static unsigned int sv_gamemode;
static unsigned int sv_gamemission;
static net_gamesettings_t sv_settings;
// For registration with master server:
static net_addr_t *master_server = NULL;
static unsigned int master_refresh_time;
static unsigned int master_resolve_time;
// receive window
static unsigned int recvwindow_start;
static net_client_recv_t recvwindow[BACKUPTICS][NET_MAXPLAYERS];
#define NET_SV_ExpandTicNum(b) NET_ExpandTicNum(recvwindow_start, (b))
static void NET_SV_DisconnectClient(net_client_t *client)
{
if (client->active)
{
NET_Conn_Disconnect(&client->connection);
}
}
static boolean ClientConnected(net_client_t *client)
{
// Check that the client is properly connected: ie. not in the
// process of connecting or disconnecting
return client->active
&& client->connection.state == NET_CONN_STATE_CONNECTED;
}
// Send a message to be displayed on a client's console
static void NET_SV_SendConsoleMessage(net_client_t *client, const char *s, ...) PRINTF_ATTR(2, 3);
static void NET_SV_SendConsoleMessage(net_client_t *client, const char *s, ...)
{
char buf[1024];
va_list args;
net_packet_t *packet;
va_start(args, s);
M_vsnprintf(buf, sizeof(buf), s, args);
va_end(args);
packet = NET_Conn_NewReliable(&client->connection,
NET_PACKET_TYPE_CONSOLE_MESSAGE);
NET_WriteString(packet, buf);
}
// Send a message to all clients
static void NET_SV_BroadcastMessage(const char *s, ...) PRINTF_ATTR(1, 2);
static void NET_SV_BroadcastMessage(const char *s, ...)
{
char buf[1024];
va_list args;
int i;
va_start(args, s);
M_vsnprintf(buf, sizeof(buf), s, args);
va_end(args);
for (i=0; i<MAXNETNODES; ++i)
{
if (ClientConnected(&clients[i]))
{
NET_SV_SendConsoleMessage(&clients[i], "%s", buf);
}
}
printf("%s\n", buf);
}
// Assign player numbers to connected clients
static void NET_SV_AssignPlayers(void)
{
int i;
int pl;
pl = 0;
for (i=0; i<MAXNETNODES; ++i)
{
if (ClientConnected(&clients[i]))
{
if (!clients[i].drone)
{
sv_players[pl] = &clients[i];
sv_players[pl]->player_number = pl;
++pl;
}
else
{
clients[i].player_number = -1;
}
}
}
for (; pl<NET_MAXPLAYERS; ++pl)
{
sv_players[pl] = NULL;
}
}
// Returns the number of players currently connected.
static int NET_SV_NumPlayers(void)
{
int i;
int result;
result = 0;
for (i=0; i<NET_MAXPLAYERS; ++i)
{
if (sv_players[i] != NULL && ClientConnected(sv_players[i]))
{
result += 1;
}
}
return result;
}
// Returns the number of players ready to start the game.
static int NET_SV_NumReadyPlayers(void)
{
int result = 0;
int i;
for (i = 0; i < MAXNETNODES; ++i)
{
if (ClientConnected(&clients[i])
&& !clients[i].drone && clients[i].ready)
{
++result;
}
}
return result;
}
// Returns the maximum number of players that can play.
static int NET_SV_MaxPlayers(void)
{
int i;
for (i = 0; i < MAXNETNODES; ++i)
{
if (ClientConnected(&clients[i]))
{
return clients[i].max_players;
}
}
return NET_MAXPLAYERS;
}
// Returns the number of drones currently connected.
static int NET_SV_NumDrones(void)
{
int i;
int result;
result = 0;
for (i=0; i<MAXNETNODES; ++i)
{
if (ClientConnected(&clients[i]) && clients[i].drone)
{
result += 1;
}
}
return result;
}
// returns the number of clients connected
static int NET_SV_NumClients(void)
{
int count;
int i;
count = 0;
for (i=0; i<MAXNETNODES; ++i)
{
if (ClientConnected(&clients[i]))
{
++count;
}
}
return count;
}
// returns a pointer to the client which controls the server
static net_client_t *NET_SV_Controller(void)
{
net_client_t *best;
int i;
// Find the oldest client (first to connect).
best = NULL;
for (i=0; i<MAXNETNODES; ++i)
{
// Can't be controller?
if (!ClientConnected(&clients[i]) || clients[i].drone)
{
continue;
}
if (best == NULL || clients[i].connect_time < best->connect_time)
{
best = &clients[i];
}
}
return best;
}
static void NET_SV_SendWaitingData(net_client_t *client)
{
net_waitdata_t wait_data;
net_packet_t *packet;
net_client_t *controller;
int i;
NET_SV_AssignPlayers();
controller = NET_SV_Controller();
wait_data.num_players = NET_SV_NumPlayers();
wait_data.num_drones = NET_SV_NumDrones();
wait_data.ready_players = NET_SV_NumReadyPlayers();
wait_data.max_players = NET_SV_MaxPlayers();
wait_data.is_controller = (client == controller);
wait_data.consoleplayer = client->player_number;
// Send the WAD and dehacked checksums of the controlling client.
// If no controller found (?), send the details that the client
// is expecting anyway.
if (controller == NULL)
{
controller = client;
}
memcpy(&wait_data.wad_sha1sum, &controller->wad_sha1sum,
sizeof(sha1_digest_t));
memcpy(&wait_data.deh_sha1sum, &controller->deh_sha1sum,
sizeof(sha1_digest_t));
wait_data.is_freedoom = controller->is_freedoom;
// set name and address of each player:
for (i = 0; i < wait_data.num_players; ++i)
{
M_StringCopy(wait_data.player_names[i],
sv_players[i]->name,
MAXPLAYERNAME);
M_StringCopy(wait_data.player_addrs[i],
NET_AddrToString(sv_players[i]->addr),
MAXPLAYERNAME);
}
// Construct packet:
packet = NET_NewPacket(10);
NET_WriteInt16(packet, NET_PACKET_TYPE_WAITING_DATA);
NET_WriteWaitData(packet, &wait_data);
// Send packet to client and free
NET_Conn_SendPacket(&client->connection, packet);
NET_FreePacket(packet);
}
// Find the latest tic which has been acknowledged as received by
// all clients.
static unsigned int NET_SV_LatestAcknowledged(void)
{
unsigned int lowtic = UINT_MAX;
int i;
for (i=0; i<MAXNETNODES; ++i)
{
if (ClientConnected(&clients[i]))
{
if (clients[i].acknowledged < lowtic)
{
lowtic = clients[i].acknowledged;
}
}
}
return lowtic;
}
// Possibly advance the recv window if all connected clients have
// used the data in the window
static void NET_SV_AdvanceWindow(void)
{
unsigned int lowtic;
int i;
if (NET_SV_NumPlayers() <= 0)
{
return;
}
lowtic = NET_SV_LatestAcknowledged();
// Advance the recv window until it catches up with lowtic
while (recvwindow_start < lowtic)
{
boolean should_advance;
// Check we have tics from all players for first tic in
// the recv window
should_advance = true;
for (i=0; i<NET_MAXPLAYERS; ++i)
{
if (sv_players[i] == NULL || !ClientConnected(sv_players[i]))
{
continue;
}
if (!recvwindow[0][i].active)
{
should_advance = false;
break;
}
}
if (!should_advance)
{
// The first tic is not complete: ie. we have not
// received tics from all connected players. This can
// happen if only one player is in the game.
break;
}
// Advance the window
memmove(recvwindow, recvwindow + 1,
sizeof(*recvwindow) * (BACKUPTICS - 1));
memset(&recvwindow[BACKUPTICS-1], 0, sizeof(*recvwindow));
++recvwindow_start;
NET_Log("server: advanced receive window to %d", recvwindow_start);
}
}
// Given an address, find the corresponding client
static net_client_t *NET_SV_FindClient(net_addr_t *addr)
{
int i;
for (i=0; i<MAXNETNODES; ++i)
{
if (clients[i].active && clients[i].addr == addr)
{
// found the client
return &clients[i];
}
}
return NULL;
}
// send a rejection packet to a client
static void NET_SV_SendReject(net_addr_t *addr, const char *msg)
{
net_packet_t *packet;
NET_Log("server: sending reject to %s", NET_AddrToString(addr));
packet = NET_NewPacket(10);
NET_WriteInt16(packet, NET_PACKET_TYPE_REJECTED);
NET_WriteString(packet, msg);
NET_SendPacket(addr, packet);
NET_FreePacket(packet);
}
static void NET_SV_InitNewClient(net_client_t *client, net_addr_t *addr,
net_protocol_t protocol)
{
client->active = true;
client->connect_time = I_GetTimeMS();
NET_Conn_InitServer(&client->connection, addr, protocol);
client->addr = addr;
NET_ReferenceAddress(addr);
client->last_send_time = -1;
// init the ticcmd send queue
client->sendseq = 0;
client->acknowledged = 0;
client->drone = false;
client->ready = false;
client->last_gamedata_time = 0;
memset(client->sendqueue, 0xff, sizeof(client->sendqueue));
NET_Log("server: initialized new client from %s", NET_AddrToString(addr));
}
// parse a SYN from a client(initiating a connection)
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);
}
// Parse a launch packet. This is sent by the key player when the "start"
// button is pressed, and causes the startup process to continue.
static void NET_SV_ParseLaunch(net_packet_t *packet, net_client_t *client)
{
net_packet_t *launchpacket;
int num_players;
unsigned int i;
NET_Log("server: processing launch packet");
// Only the controller can launch the game.
if (client != NET_SV_Controller())
{
NET_Log("server: error: this client isn't the controller, %d != %d",
client, NET_SV_Controller());
return;
}
// Can only launch when we are in the waiting state.
if (server_state != SERVER_WAITING_LAUNCH)
{
NET_Log("server: error: not in waiting launch state, state=%d",
server_state);
return;
}
// Forward launch on to all clients.
NET_Log("server: sending launch to all clients");
NET_SV_AssignPlayers();
num_players = NET_SV_NumPlayers();
for (i=0; i<MAXNETNODES; ++i)
{
if (!ClientConnected(&clients[i]))
continue;
launchpacket = NET_Conn_NewReliable(&clients[i].connection,
NET_PACKET_TYPE_LAUNCH);
NET_WriteInt8(launchpacket, num_players);
}
// Now in launch state.
server_state = SERVER_WAITING_START;
}
// Transition to the in-game state and send all players the start game
// message. Invoked once all players have indicated they are ready to
// start the game.
static void StartGame(void)
{
net_packet_t *startpacket;
unsigned int i;
int nowtime;
// Assign player numbers
NET_SV_AssignPlayers();
// Check if anyone is recording a demo and set lowres_turn if so.
sv_settings.lowres_turn = false;
for (i = 0; i < NET_MAXPLAYERS; ++i)
{
if (sv_players[i] != NULL && sv_players[i]->recording_lowres)
{
sv_settings.lowres_turn = true;
}
}
sv_settings.num_players = NET_SV_NumPlayers();
// Copy player classes:
for (i = 0; i < NET_MAXPLAYERS; ++i)
{
if (sv_players[i] != NULL)
{
sv_settings.player_classes[i] = sv_players[i]->player_class;
}
else
{
sv_settings.player_classes[i] = 0;
}
}
nowtime = I_GetTimeMS();
// Send start packets to each connected node
for (i = 0; i < MAXNETNODES; ++i)
{
if (!ClientConnected(&clients[i]))
continue;
clients[i].last_gamedata_time = nowtime;
startpacket = NET_Conn_NewReliable(&clients[i].connection,
NET_PACKET_TYPE_GAMESTART);
sv_settings.consoleplayer = clients[i].player_number;
NET_WriteSettings(startpacket, &sv_settings);
}
// Change server state
NET_Log("server: beginning game state");
server_state = SERVER_IN_GAME;
memset(recvwindow, 0, sizeof(recvwindow));
recvwindow_start = 0;
}
// Returns true when all nodes have indicated readiness to start the game.
static boolean AllNodesReady(void)
{
unsigned int i;
for (i = 0; i < MAXNETNODES; ++i)
{
if (ClientConnected(&clients[i]) && !clients[i].ready)
{
return false;
}
}
return true;
}
// Check if the game should start, and if so, start it.
static void CheckStartGame(void)
{
if (!AllNodesReady())
{
NET_Log("server: not all clients ready to start yet");
return;
}
NET_Log("server: all clients ready, starting game");
StartGame();
}
// Send waiting data with current status to all nodes that are ready to
// start the game.
static void SendAllWaitingData(void)
{
unsigned int i;
for (i = 0; i < MAXNETNODES; ++i)
{
if (ClientConnected(&clients[i]) && clients[i].ready)
{
NET_SV_SendWaitingData(&clients[i]);
}
}
}
// Parse a game start packet
static void NET_SV_ParseGameStart(net_packet_t *packet, net_client_t *client)
{
net_gamesettings_t settings;
NET_Log("server: processing game start packet");
// Can only start a game if we are in the waiting start state.
if (server_state != SERVER_WAITING_START)
{
NET_Log("server: error: not in waiting start state, server_state=%d",
server_state);
return;
}
if (client == NET_SV_Controller())
{
if (!NET_ReadSettings(packet, &settings))
{
// Malformed packet
NET_Log("server: error: no settings from controller");
return;
}
// Check the game settings are valid
if (!NET_ValidGameSettings(sv_gamemode, sv_gamemission, &settings))
{
NET_Log("server: error: invalid game settings");
return;
}
sv_settings = settings;
}
client->ready = true;
CheckStartGame();
// Update all ready clients with the current state (number of players
// ready, etc.). This is used by games that show startup progress
// (eg. Hexen's spinal loading)
SendAllWaitingData();
}
// Send a resend request to a client
static void NET_SV_SendResendRequest(net_client_t *client, int start, int end)
{
net_packet_t *packet;
net_client_recv_t *recvobj;
int i;
unsigned int nowtime;
int index;
NET_Log("server: send resend to %s for tics %d-%d",
NET_AddrToString(client->addr), start, end);
packet = NET_NewPacket(20);
NET_WriteInt16(packet, NET_PACKET_TYPE_GAMEDATA_RESEND);
NET_WriteInt32(packet, start);
NET_WriteInt8(packet, end - start + 1);
NET_Conn_SendPacket(&client->connection, packet);
NET_FreePacket(packet);
// Store the time we send the resend request
nowtime = I_GetTimeMS();
for (i=start; i<=end; ++i)
{
index = i - recvwindow_start;
if (index >= BACKUPTICS)
{
// Outside the range
continue;
}
recvobj = &recvwindow[index][client->player_number];
recvobj->resend_time = nowtime;
}
}
// Check for expired resend requests
static void NET_SV_CheckResends(net_client_t *client)
{
int i;
int player;
int resend_start, resend_end;
unsigned int nowtime;
nowtime = I_GetTimeMS();
player = client->player_number;
resend_start = -1;
resend_end = -1;
for (i=0; i<BACKUPTICS; ++i)
{
net_client_recv_t *recvobj;
boolean need_resend;
recvobj = &recvwindow[i][player];
// if need_resend is true, this tic needs another retransmit
// request (300ms timeout)
need_resend = !recvobj->active
&& recvobj->resend_time != 0
&& nowtime > recvobj->resend_time + 300;
if (need_resend)
{
// Start a new run of resend tics?
if (resend_start < 0)
{
resend_start = i;
}
resend_end = i;
}
else if (resend_start >= 0)
{
// End of a run of resend tics
NET_Log("server: resend request to %s timed out for %d-%d (%d)",
NET_AddrToString(client->addr),
recvwindow_start + resend_start,
recvwindow_start + resend_end,
&recvwindow[resend_start][player].resend_time);
NET_SV_SendResendRequest(client,
recvwindow_start + resend_start,
recvwindow_start + resend_end);
resend_start = -1;
}
}
if (resend_start >= 0)
{
NET_Log("server: resend request to %s timed out for %d-%d (%d)",
NET_AddrToString(client->addr),
recvwindow_start + resend_start,
recvwindow_start + resend_end,
&recvwindow[resend_start][player].resend_time);
NET_SV_SendResendRequest(client,
recvwindow_start + resend_start,
recvwindow_start + resend_end);
}
}
// Process game data from a client
static void NET_SV_ParseGameData(net_packet_t *packet, net_client_t *client)
{
net_client_recv_t *recvobj;
unsigned int seq;
unsigned int ackseq;
unsigned int num_tics;
unsigned int nowtime;
size_t i;
int player;
int resend_start, resend_end;
int index;
if (server_state != SERVER_IN_GAME)
{
NET_Log("server: error: not in game state: server_state=%d",
server_state);
return;
}
if (client->drone)
{
// Drones do not contribute any game data.
NET_Log("server: error: game data from a drone?");
return;
}
player = client->player_number;
// Read header
if (!NET_ReadInt8(packet, &ackseq)
|| !NET_ReadInt8(packet, &seq)
|| !NET_ReadInt8(packet, &num_tics))
{
NET_Log("server: error: failed to read header");
return;
}
NET_Log("server: got game data, seq=%d, num_tics=%d, ackseq=%d",
seq, num_tics, ackseq);
// Get the current time
nowtime = I_GetTimeMS();
// Expand 8-bit values to the full sequence number
ackseq = NET_SV_ExpandTicNum(ackseq);
seq = NET_SV_ExpandTicNum(seq);
// Sanity checks
for (i=0; i<num_tics; ++i)
{
net_ticdiff_t diff;
signed int latency;
if (!NET_ReadSInt16(packet, &latency)
|| !NET_ReadTiccmdDiff(packet, &diff, sv_settings.lowres_turn))
{
return;
}
index = seq + i - recvwindow_start;
if (index < 0 || index >= BACKUPTICS)
{
// Not in range of the recv window
continue;
}
recvobj = &recvwindow[index][player];
recvobj->active = true;
recvobj->diff = diff;
recvobj->latency = latency;
client->last_gamedata_time = nowtime;
NET_Log("server: stored tic %d for player %d", seq + i, player);
}
// Higher acknowledgement point?
if (ackseq > client->acknowledged)
{
NET_Log("server: acknowledged up to %d", ackseq);
client->acknowledged = ackseq;
}
// Has this been received out of sequence, ie. have we not received
// all tics before the first tic in this packet? If so, send a
// resend request.
//printf("SV: %p: %i\n", client, seq);
resend_end = seq - recvwindow_start;
if (resend_end <= 0)
return;
if (resend_end >= BACKUPTICS)
resend_end = BACKUPTICS - 1;
index = resend_end - 1;
resend_start = resend_end;
while (index >= 0)
{
recvobj = &recvwindow[index][player];
if (recvobj->active)
{
// ended our run of unreceived tics
break;
}
if (recvobj->resend_time != 0)
{
// Already sent a resend request for this tic
break;
}
resend_start = index;
--index;
}
// Possibly send a resend request
if (resend_start < resend_end)
{
NET_Log("server: request resend for %d-%d before %d",
recvwindow_start + resend_start,
recvwindow_start + resend_end - 1, seq);
NET_SV_SendResendRequest(client,
recvwindow_start + resend_start,
recvwindow_start + resend_end - 1);
}
}
static void NET_SV_ParseGameDataACK(net_packet_t *packet, net_client_t *client)
{
unsigned int ackseq;
NET_Log("server: processing game data ack packet");
if (server_state != SERVER_IN_GAME)
{
NET_Log("server: error: not in game state, server_state=%d",
server_state);
return;
}
// Read header
if (!NET_ReadInt8(packet, &ackseq))
{
NET_Log("server: error: missing acknowledgement field");
return;
}
// Expand 8-bit values to the full sequence number
ackseq = NET_SV_ExpandTicNum(ackseq);
// Higher acknowledgement point than we already have?
if (ackseq > client->acknowledged)
{
NET_Log("server: acknowledged up to %d", ackseq);
client->acknowledged = ackseq;
}
}
static void NET_SV_SendTics(net_client_t *client,
unsigned int start, unsigned int end)
{
net_packet_t *packet;
unsigned int i;
packet = NET_NewPacket(500);
NET_WriteInt16(packet, NET_PACKET_TYPE_GAMEDATA);
// Send the start tic and number of tics
NET_WriteInt8(packet, start & 0xff);
NET_WriteInt8(packet, end-start + 1);
// Write the tics
for (i=start; i<=end; ++i)
{
net_full_ticcmd_t *cmd;
cmd = &client->sendqueue[i % BACKUPTICS];
if (i != cmd->seq)
{
I_Error("Wanted to send %i, but %i is in its place", i, cmd->seq);
}
// Add command
NET_WriteFullTiccmd(packet, cmd, sv_settings.lowres_turn);
}
// Send packet
NET_Conn_SendPacket(&client->connection, packet);
NET_FreePacket(packet);
}
// Parse a retransmission request from a client
static void NET_SV_ParseResendRequest(net_packet_t *packet, net_client_t *client)
{
unsigned int start, last;
unsigned int num_tics;
unsigned int i;
NET_Log("server: processing resend request");
// Read the starting tic and number of tics
if (!NET_ReadInt32(packet, &start)
|| !NET_ReadInt8(packet, &num_tics))
{
NET_Log("server: error: missing fields for resend");
return;
}
//printf("SV: %p: resend %i-%i\n", client, start, start+num_tics-1);
// Check we have all the requested tics
last = start + num_tics - 1;
for (i=start; i<=last; ++i)
{
net_full_ticcmd_t *cmd;
cmd = &client->sendqueue[i % BACKUPTICS];
if (i != cmd->seq)
{
// We do not have the requested tic (any more)
// This is pretty fatal. We could disconnect the client,
// but then again this could be a spoofed packet. Just
// ignore it.
NET_Log("server: error: don't have tic %d any more, "
"can't resend", i);
return;
}
}
// Resend those tics
NET_Log("server: resending tics %d-%d", start, last);
NET_SV_SendTics(client, start, last);
}
// Send a response back to the client
void NET_SV_SendQueryResponse(net_addr_t *addr)
{
net_packet_t *reply;
net_querydata_t querydata;
int p;
// Version
querydata.version = PACKAGE_STRING;
// Server state
querydata.server_state = server_state;
// Number of players/maximum players
querydata.num_players = NET_SV_NumPlayers();
querydata.max_players = NET_SV_MaxPlayers();
// Game mode/mission
querydata.gamemode = sv_gamemode;
querydata.gamemission = sv_gamemission;
//!
// @category net
// @arg <name>
//
// When starting a network server, specify a name for the server.
//
p = M_CheckParmWithArgs("-servername", 1);
if (p > 0)
{
querydata.description = myargv[p + 1];
}
else
{
querydata.description = "Unnamed server";
}
// Send it and we're done.
NET_Log("server: sending query response to %s", NET_AddrToString(addr));
reply = NET_NewPacket(64);
NET_WriteInt16(reply, NET_PACKET_TYPE_QUERY_RESPONSE);
NET_WriteQueryData(reply, &querydata);
NET_SendPacket(addr, reply);
NET_FreePacket(reply);
}
static void NET_SV_ParseHolePunch(net_packet_t *packet)
{
const char *addr_string;
net_packet_t *sendpacket;
net_addr_t *addr;
addr_string = NET_ReadString(packet);
if (addr_string == NULL)
{
NET_Log("server: error: hole punch request but no address provided");
return;
}
addr = NET_ResolveAddress(server_context, addr_string);
if (addr == NULL)
{
NET_Log("server: error: failed to resolve address: %s", addr_string);
return;
}
sendpacket = NET_NewPacket(16);
NET_WriteInt16(sendpacket, NET_PACKET_TYPE_NAT_HOLE_PUNCH);
NET_SendPacket(addr, sendpacket);
NET_FreePacket(sendpacket);
NET_ReleaseAddress(addr);
NET_Log("server: sent hole punch to %s", addr_string);
}
static void NET_SV_MasterPacket(net_packet_t *packet)
{
unsigned int packet_type;
// Read the packet type
if (!NET_ReadInt16(packet, &packet_type))
{
NET_Log("server: error: no packet type in master server message");
return;
}
NET_Log("server: packet from master server; type %d", packet_type);
NET_LogPacket(packet);
switch (packet_type)
{
case NET_MASTER_PACKET_TYPE_ADD_RESPONSE:
NET_Query_AddResponse(packet);
break;
case NET_MASTER_PACKET_TYPE_NAT_HOLE_PUNCH:
NET_SV_ParseHolePunch(packet);
break;
}
}
// Process a packet received by the server
static void NET_SV_Packet(net_packet_t *packet, net_addr_t *addr)
{
net_client_t *client;
unsigned int packet_type;
// Response from master server?
if (addr != NULL && addr == master_server)
{
NET_SV_MasterPacket(packet);
return;
}
// Find which client this packet came from
client = NET_SV_FindClient(addr);
// Read the packet type
if (!NET_ReadInt16(packet, &packet_type))
{
// no packet type
return;
}
NET_Log("server: packet from %s; type %d", NET_AddrToString(addr),
packet_type & ~NET_RELIABLE_PACKET);
NET_LogPacket(packet);
if (packet_type == NET_PACKET_TYPE_SYN)
{
NET_SV_ParseSYN(packet, client, addr);
}
else if (packet_type == NET_PACKET_TYPE_QUERY)
{
NET_SV_SendQueryResponse(addr);
}
else if (client == NULL)
{
// Must come from a valid client; ignore otherwise
}
else if (NET_Conn_Packet(&client->connection, packet, &packet_type))
{
// Packet was eaten by the common connection code
}
else
{
//printf("SV: %s: %i\n", NET_AddrToString(addr), packet_type);
switch (packet_type)
{
case NET_PACKET_TYPE_GAMESTART:
NET_SV_ParseGameStart(packet, client);
break;
case NET_PACKET_TYPE_LAUNCH:
NET_SV_ParseLaunch(packet, client);
break;
case NET_PACKET_TYPE_GAMEDATA:
NET_SV_ParseGameData(packet, client);
break;
case NET_PACKET_TYPE_GAMEDATA_ACK:
NET_SV_ParseGameDataACK(packet, client);
break;
case NET_PACKET_TYPE_GAMEDATA_RESEND:
NET_SV_ParseResendRequest(packet, client);
break;
default:
// unknown packet type
break;
}
}
}
static void NET_SV_PumpSendQueue(net_client_t *client)
{
net_full_ticcmd_t cmd;
int recv_index;
int num_players;
int i;
int starttic, endtic;
// If a client has not sent any acknowledgments for a while,
// wait until they catch up.
if (client->sendseq - NET_SV_LatestAcknowledged() > 40)
{
return;
}
// Work out the index into the receive window
recv_index = client->sendseq - recvwindow_start;
if (recv_index < 0 || recv_index >= BACKUPTICS)
{
return;
}
// Check if we can generate a new entry for the send queue
// using the data in recvwindow.
num_players = 0;
for (i=0; i<NET_MAXPLAYERS; ++i)
{
if (sv_players[i] == client)
{
// Client does not rely on itself for data
continue;
}
if (sv_players[i] == NULL || !ClientConnected(sv_players[i]))
{
continue;
}
if (!recvwindow[recv_index][i].active)
{
// We do not have this player's ticcmd, so we cannot
// generate a complete command yet.
return;
}
++num_players;
}
// If this is a game with only a single player in it, we might
// be sending a ticcmd set containing 0 ticcmds. This is fine;
// however, there's nothing to stop the game running on ahead
// and never stopping. Don't let the server get too far ahead
// of the client.
if (num_players == 0 && client->sendseq > recvwindow_start + 10)
{
return;
}
// We have all data we need to generate a command for this tic.
cmd.seq = client->sendseq;
// Add ticcmds from all players
cmd.latency = 0;
for (i=0; i<NET_MAXPLAYERS; ++i)
{
net_client_recv_t *recvobj;
if (sv_players[i] == client)
{
// Not the player we are sending to
cmd.playeringame[i] = false;
continue;
}
if (sv_players[i] == NULL || !recvwindow[recv_index][i].active)
{
cmd.playeringame[i] = false;
continue;
}
cmd.playeringame[i] = true;
recvobj = &recvwindow[recv_index][i];
cmd.cmds[i] = recvobj->diff;
if (recvobj->latency > cmd.latency)
cmd.latency = recvobj->latency;
}
//printf("SV: %i: latency %i\n", client->player_number, cmd.latency);
// Add into the queue
client->sendqueue[client->sendseq % BACKUPTICS] = cmd;
// Transmit the new tic to the client
starttic = client->sendseq - sv_settings.extratics;
endtic = client->sendseq;
if (starttic < 0)
starttic = 0;
NET_Log("server: send tics %d-%d to %s", starttic, endtic,
NET_AddrToString(client->addr));
NET_SV_SendTics(client, starttic, endtic);
++client->sendseq;
}
// Prevent against deadlock: resend requests are usually only
// triggered if we miss a packet and receive the next one.
// If we miss a whole load of packets, we can end up in a
// deadlock situation where the client will not send any more.
// If we don't receive any game data in a while, trigger a resend
// request for the next tic we're expecting.
void NET_SV_CheckDeadlock(net_client_t *client)
{
int nowtime;
int i;
// Don't expect game data from clients.
if (client->drone)
{
return;
}
nowtime = I_GetTimeMS();
// If we haven't received anything for a long time, it may be a deadlock.
if (nowtime - client->last_gamedata_time > 1000)
{
NET_Log("server: no gamedata from %s since %d - deadlock?",
NET_AddrToString(client->addr),
client->last_gamedata_time);
// Search the receive window for the first tic we are expecting
// from this player.
for (i=0; i<BACKUPTICS; ++i)
{
if (!recvwindow[i][client->player_number].active)
{
NET_Log("server: deadlock: sending resend request for %d-%d",
recvwindow_start + i, recvwindow_start + i + 5);
// Found a tic we haven't received. Send a resend request.
NET_SV_SendResendRequest(client,
recvwindow_start + i,
recvwindow_start + i + 5);
client->last_gamedata_time = nowtime;
break;
}
}
// If we sent a resend request to break the deadlock, also trigger a
// resend of any tics we have sitting in the send queue, in case the
// client is blocked waiting on tics from us that have been lost.
// This fixes deadlock with some older clients which do not send
// resends to break deadlock.
if (i < BACKUPTICS && client->sendseq > client->acknowledged)
{
NET_Log("server: also resending tics %d-%d to break deadlock",
client->acknowledged, client->sendseq - 1);
NET_SV_SendTics(client, client->acknowledged, client->sendseq - 1);
}
}
}
// Called when all players have disconnected. Return to listening for
// players to start a new game, and disconnect any drones still connected.
static void NET_SV_GameEnded(void)
{
int i;
server_state = SERVER_WAITING_LAUNCH;
sv_gamemode = indetermined;
for (i=0; i<MAXNETNODES; ++i)
{
if (clients[i].active)
{
NET_SV_DisconnectClient(&clients[i]);
}
}
}
// Perform any needed action on a client
static void NET_SV_RunClient(net_client_t *client)
{
// Run common code
NET_Conn_Run(&client->connection);
if (client->connection.state == NET_CONN_STATE_DISCONNECTED
&& client->connection.disconnect_reason == NET_DISCONNECT_TIMEOUT)
{
NET_Log("server: client at %s timed out",
NET_AddrToString(client->addr));
NET_SV_BroadcastMessage("Client '%s' timed out and disconnected",
client->name);
}
// Is this client disconnected?
if (client->connection.state == NET_CONN_STATE_DISCONNECTED)
{
client->active = false;
// If we were about to start a game, any player disconnecting
// should cause an abort.
if (server_state == SERVER_WAITING_START && !client->drone)
{
NET_SV_BroadcastMessage("Game startup aborted because "
"player '%s' disconnected.",
client->name);
NET_SV_GameEnded();
}
free(client->name);
NET_ReleaseAddress(client->addr);
// Are there any clients left connected? If not, return the
// server to the waiting-for-players state.
//
// Disconnect any drones still connected.
if (NET_SV_NumPlayers() <= 0)
{
NET_Log("server: no player clients left, game ended");
NET_SV_GameEnded();
}
}
if (!ClientConnected(client))
{
// client has not yet finished connecting
return;
}
if (server_state == SERVER_WAITING_LAUNCH)
{
// Waiting for the game to start
// Send information once every second
if (client->last_send_time < 0
|| I_GetTimeMS() - client->last_send_time > 1000)
{
NET_SV_SendWaitingData(client);
client->last_send_time = I_GetTimeMS();
}
}
if (server_state == SERVER_IN_GAME)
{
NET_SV_PumpSendQueue(client);
NET_SV_CheckDeadlock(client);
}
}
// Add a network module to the server context
void NET_SV_AddModule(net_module_t *module)
{
module->InitServer();
NET_AddModule(server_context, module);
}
// Initialize server and wait for connections
void NET_SV_Init(void)
{
int i;
// initialize send/receive context
server_context = NET_NewContext();
// no clients yet
for (i=0; i<MAXNETNODES; ++i)
{
clients[i].active = false;
}
NET_SV_AssignPlayers();
server_state = SERVER_WAITING_LAUNCH;
sv_gamemode = indetermined;
server_initialized = true;
}
static void UpdateMasterServer(void)
{
unsigned int now;
now = I_GetTimeMS();
// The address of the master server can change. Periodically
// re-resolve the master server to update.
if (now - master_resolve_time > MASTER_RESOLVE_PERIOD * 1000)
{
net_addr_t *new_addr;
new_addr = NET_Query_ResolveMaster(server_context);
NET_ReleaseAddress(master_server);
master_server = new_addr;
master_resolve_time = now;
}
// Possibly refresh our registration with the master server.
if (now - master_refresh_time > MASTER_REFRESH_PERIOD * 1000)
{
NET_Query_AddToMaster(master_server);
master_refresh_time = now;
}
}
void NET_SV_RegisterWithMaster(void)
{
//!
// @category net
//
// When running a server, don't register with the global master server.
// Implies -server.
//
if (!M_CheckParm("-privateserver"))
{
master_server = NET_Query_ResolveMaster(server_context);
}
else
{
master_server = NULL;
}
// Send request.
if (master_server != NULL)
{
NET_Query_AddToMaster(master_server);
master_refresh_time = I_GetTimeMS();
master_resolve_time = master_refresh_time;
}
}
// Run server code to check for new packets/send packets as the server
// requires
void NET_SV_Run(void)
{
net_addr_t *addr;
net_packet_t *packet;
int i;
if (!server_initialized)
{
return;
}
while (NET_RecvPacket(server_context, &addr, &packet))
{
NET_SV_Packet(packet, addr);
NET_FreePacket(packet);
NET_ReleaseAddress(addr);
}
if (master_server != NULL)
{
UpdateMasterServer();
}
// "Run" any clients that may have things to do, independent of responses
// to received packets
for (i=0; i<MAXNETNODES; ++i)
{
if (clients[i].active)
{
NET_SV_RunClient(&clients[i]);
}
}
switch (server_state)
{
case SERVER_WAITING_LAUNCH:
break;
case SERVER_WAITING_START:
CheckStartGame();
break;
case SERVER_IN_GAME:
NET_SV_AdvanceWindow();
for (i = 0; i < NET_MAXPLAYERS; ++i)
{
if (sv_players[i] != NULL && ClientConnected(sv_players[i]))
{
NET_SV_CheckResends(sv_players[i]);
}
}
break;
}
}
void NET_SV_Shutdown(void)
{
int i;
boolean running;
int start_time;
if (!server_initialized)
{
return;
}
fprintf(stderr, "SV: Shutting down server...\n");
// Disconnect all clients
for (i=0; i<MAXNETNODES; ++i)
{
if (clients[i].active)
{
NET_SV_DisconnectClient(&clients[i]);
}
}
// Wait for all clients to finish disconnecting
start_time = I_GetTimeMS();
running = true;
while (running)
{
// Check if any clients are still not finished
running = false;
for (i=0; i<MAXNETNODES; ++i)
{
if (clients[i].active)
{
running = true;
}
}
// Timed out?
if (I_GetTimeMS() - start_time > 5000)
{
running = false;
fprintf(stderr, "SV: Timed out waiting for clients to disconnect.\n");
}
// Run the client code in case this is a loopback client.
NET_CL_Run();
NET_SV_Run();
// Don't hog the CPU
I_Sleep(1);
}
}