ref: 5193587afe42a06f8f73cbc1fc4bedd3e0506562
dir: /src/net_server.c/
// Emacs style mode select -*- C++ -*-
//-----------------------------------------------------------------------------
//
// Copyright(C) 2005 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.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
// 02111-1307, USA.
//
// Network server code
//
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include "config.h"
#include "doomdef.h"
#include "doomstat.h"
#include "i_system.h"
#include "i_timer.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_server.h"
#include "net_sdl.h"
#include "net_structrw.h"
typedef enum
{
// waiting for the game to 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;
// 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;
// Observer: receives data but does not participate in the game.
boolean drone;
// MD5 hash sums of the client's WAD directory and dehacked data
md5_digest_t wad_md5sum;
md5_digest_t deh_md5sum;
// Is this client is playing with the Freedoom IWAD?
unsigned int is_freedoom;
} 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_initialised = false;
static net_client_t clients[MAXNETNODES];
static net_client_t *sv_players[MAXPLAYERS];
static net_context_t *server_context;
static unsigned int sv_gamemode;
static unsigned int sv_gamemission;
static net_gamesettings_t sv_settings;
// receive window
static unsigned int recvwindow_start;
static net_client_recv_t recvwindow[BACKUPTICS][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, char *s, ...)
{
char buf[1024];
va_list args;
net_packet_t *packet;
va_start(args, s);
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(char *s, ...)
{
char buf[1024];
va_list args;
int i;
va_start(args, s);
vsnprintf(buf, sizeof(buf), s, args);
va_end(args);
for (i=0; i<MAXNETNODES; ++i)
{
if (ClientConnected(&clients[i]))
{
NET_SV_SendConsoleMessage(&clients[i], buf);
}
}
NET_SafePuts(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<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<MAXPLAYERS; ++i)
{
if (sv_players[i] != NULL && ClientConnected(sv_players[i]))
{
result += 1;
}
}
return result;
}
// 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;
}
// 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<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
memcpy(recvwindow, recvwindow + 1, sizeof(*recvwindow) * (BACKUPTICS - 1));
memset(&recvwindow[BACKUPTICS-1], 0, sizeof(*recvwindow));
++recvwindow_start;
//printf("SV: advanced to %i\n", recvwindow_start);
}
}
// returns a pointer to the client which controls the server
static net_client_t *NET_SV_Controller(void)
{
int i;
// first client in the list is the controller
for (i=0; i<MAXNETNODES; ++i)
{
if (ClientConnected(&clients[i]) && !clients[i].drone)
{
return &clients[i];
}
}
return NULL;
}
// 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, char *msg)
{
net_packet_t *packet;
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,
char *player_name)
{
client->active = true;
NET_Conn_InitServer(&client->connection, addr);
client->addr = addr;
client->last_send_time = -1;
client->name = strdup(player_name);
// init the ticcmd send queue
client->sendseq = 0;
client->acknowledged = 0;
client->drone = false;
client->last_gamedata_time = 0;
memset(client->sendqueue, 0xff, sizeof(client->sendqueue));
}
// 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;
unsigned int cl_gamemode, cl_gamemission;
unsigned int cl_recording_lowres;
unsigned int cl_drone;
unsigned int is_freedoom;
md5_digest_t deh_md5sum, wad_md5sum;
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;
}
if (strcmp(client_version, PACKAGE_STRING) != 0)
{
NET_SV_SendReject(addr, "Different versions cannot play a network game!");
return;
}
// read the game mode and mission
if (!NET_ReadInt16(packet, &cl_gamemode)
|| !NET_ReadInt16(packet, &cl_gamemission)
|| !NET_ReadInt8(packet, &cl_recording_lowres)
|| !NET_ReadInt8(packet, &cl_drone)
|| !NET_ReadMD5Sum(packet, wad_md5sum)
|| !NET_ReadMD5Sum(packet, deh_md5sum)
|| !NET_ReadInt8(packet, &is_freedoom))
{
return;
}
if (!NET_ValidGameMode(cl_gamemode, cl_gamemission))
{
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_START)
{
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 ((!cl_drone && num_players >= 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 && !cl_drone)
{
sv_gamemode = cl_gamemode;
sv_gamemission = cl_gamemission;
}
// Save the MD5 checksums
memcpy(client->wad_md5sum, wad_md5sum, sizeof(md5_digest_t));
memcpy(client->deh_md5sum, deh_md5sum, sizeof(md5_digest_t));
client->is_freedoom = is_freedoom;
// Check the connecting client is playing the same game as all
// the other clients
if (cl_gamemode != sv_gamemode || cl_gamemission != sv_gamemission)
{
NET_SV_SendReject(addr, "You are playing the wrong game!");
return;
}
// Activate, initialise connection
NET_SV_InitNewClient(client, addr, player_name);
client->recording_lowres = cl_recording_lowres;
client->drone = cl_drone;
}
if (client->connection.state == NET_CONN_STATE_WAITING_ACK)
{
// force an acknowledgement
client->connection.last_send_time = -1;
}
}
// Parse a game start packet
static void NET_SV_ParseGameStart(net_packet_t *packet, net_client_t *client)
{
net_gamesettings_t settings;
net_packet_t *startpacket;
int nowtime;
int i;
if (client != NET_SV_Controller())
{
// Only the controller can start a new game
return;
}
if (!NET_ReadSettings(packet, &settings))
{
// Malformed packet
return;
}
// Check the game settings are valid
if (!NET_ValidGameSettings(sv_gamemode, sv_gamemission, &settings))
{
return;
}
if (server_state != SERVER_WAITING_START)
{
// Can only start a game if we are in the waiting start state.
return;
}
// Assign player numbers
NET_SV_AssignPlayers();
// Check if anyone is recording a demo and set lowres_turn if so.
settings.lowres_turn = false;
for (i=0; i<MAXPLAYERS; ++i)
{
if (sv_players[i] != NULL && sv_players[i]->recording_lowres)
{
settings.lowres_turn = true;
}
}
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);
NET_WriteInt8(startpacket, NET_SV_NumPlayers());
NET_WriteInt8(startpacket, clients[i].player_number);
NET_WriteSettings(startpacket, &settings);
}
// Change server state
server_state = SERVER_IN_GAME;
sv_settings = settings;
memset(recvwindow, 0, sizeof(recvwindow));
recvwindow_start = 0;
}
// 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;
//printf("SV: send resend for %i-%i\n", 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
//printf("SV: resend request timed out: %i-%i\n", resend_start, resend_end);
NET_SV_SendResendRequest(client,
recvwindow_start + resend_start,
recvwindow_start + resend_end);
resend_start = -1;
}
}
}
if (resend_start >= 0)
{
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)
{
return;
}
if (client->drone)
{
// Drones do not contribute any game data.
return;
}
player = client->player_number;
// Read header
if (!NET_ReadInt8(packet, &ackseq)
|| !NET_ReadInt8(packet, &seq)
|| !NET_ReadInt8(packet, &num_tics))
{
return;
}
// 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;
}
// Higher acknowledgement point?
if (ackseq > client->acknowledged)
{
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)
{
/*
printf("missed %i-%i before %i, send resend\n",
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;
if (server_state != SERVER_IN_GAME)
{
return;
}
// Read header
if (!NET_ReadInt8(packet, &ackseq))
{
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)
{
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;
// Read the starting tic and number of tics
if (!NET_ReadInt32(packet, &start)
|| !NET_ReadInt8(packet, &num_tics))
{
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.
return;
}
}
// Resend those tics
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;
// 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 = MAXPLAYERS;
// Game mode/mission
querydata.gamemode = sv_gamemode;
querydata.gamemission = sv_gamemission;
// Server description. This is currently hard-coded.
querydata.description = "Chocolate Doom server";
// Send it and we're done.
reply = NET_NewPacket(64);
NET_WriteInt16(reply, NET_PACKET_TYPE_QUERY_RESPONSE);
NET_WriteQueryData(reply, &querydata);
NET_SendPacket(addr, reply);
NET_FreePacket(reply);
}
// 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;
// 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;
}
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_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;
}
}
// If this address is not in the list of clients, be sure to
// free it back.
if (NET_SV_FindClient(addr) == NULL)
{
NET_FreeAddress(addr);
}
}
static void NET_SV_SendWaitingData(net_client_t *client)
{
net_packet_t *packet;
net_client_t *controller;
int num_players;
int i;
NET_SV_AssignPlayers();
controller = NET_SV_Controller();
num_players = NET_SV_NumPlayers();
// time to send the client another status packet
packet = NET_NewPacket(10);
NET_WriteInt16(packet, NET_PACKET_TYPE_WAITING_DATA);
// include the number of players waiting
NET_WriteInt8(packet, num_players);
// send the number of drone clients
NET_WriteInt8(packet, NET_SV_NumDrones());
// indicate whether the client is the controller
NET_WriteInt8(packet, client == controller);
// send the player number of this client
NET_WriteInt8(packet, client->player_number);
// send the addresses of all players
for (i=0; i<num_players; ++i)
{
char *addr;
// name
NET_WriteString(packet, sv_players[i]->name);
// address
addr = NET_AddrToString(sv_players[i]->addr);
NET_WriteString(packet, addr);
}
// Send the WAD and dehacked checksums of the controlling client.
if (controller != NULL)
{
NET_WriteMD5Sum(packet, controller->wad_md5sum);
NET_WriteMD5Sum(packet, controller->deh_md5sum);
NET_WriteInt8(packet, controller->is_freedoom);
}
else
{
NET_WriteMD5Sum(packet, client->wad_md5sum);
NET_WriteMD5Sum(packet, client->deh_md5sum);
NET_WriteInt8(packet, client->is_freedoom);
}
// send packet to client and free
NET_Conn_SendPacket(&client->connection, packet);
NET_FreePacket(packet);
}
static void NET_SV_PumpSendQueue(net_client_t *client)
{
net_full_ticcmd_t cmd;
int recv_index;
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.
for (i=0; i<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;
}
}
//printf("SV: have complete ticcmd for %i\n", client->sendseq);
// 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<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_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)
{
// Search the receive window for the first tic we are expecting
// from this player.
for (i=0; i<BACKUPTICS; ++i)
{
if (!recvwindow[client->player_number][i].active)
{
//printf("Possible deadlock: Sending resend request\n");
// 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;
}
}
}
}
// 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_SV_BroadcastMessage("Client '%s' timed out and disconnected",
client->name);
}
// Is this client disconnected?
if (client->connection.state == NET_CONN_STATE_DISCONNECTED)
{
// deactivate and free back
client->active = false;
free(client->name);
NET_FreeAddress(client->addr);
// Are there any clients left connected? If not, return the
// server to the waiting-for-players state.
if (NET_SV_NumClients() <= 0)
{
server_state = SERVER_WAITING_START;
sv_gamemode = indetermined;
}
}
if (!ClientConnected(client))
{
// client has not yet finished connecting
return;
}
if (server_state == SERVER_WAITING_START)
{
// 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);
}
// Initialise server and wait for connections
void NET_SV_Init(void)
{
int i;
// initialise 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_START;
sv_gamemode = indetermined;
server_initialised = true;
}
// 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_initialised)
{
return;
}
while (NET_RecvPacket(server_context, &addr, &packet))
{
NET_SV_Packet(packet, addr);
NET_FreePacket(packet);
}
// "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]);
}
}
if (server_state == SERVER_IN_GAME)
{
NET_SV_AdvanceWindow();
for (i=0; i<MAXPLAYERS; ++i)
{
if (sv_players[i] != NULL && ClientConnected(sv_players[i]))
{
NET_SV_CheckResends(sv_players[i]);
}
}
}
}
void NET_SV_Shutdown(void)
{
int i;
boolean running;
int start_time;
if (!server_initialised)
{
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);
}
}