thirtyflightsofloving/server/sv_main.c

/*
===========================================================================
Copyright (C) 1997-2001 Id Software, Inc.

This file is part of Quake 2 source code.

Quake 2 source code 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.

Quake 2 source code 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 Quake 2 source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/

// sv_main.c -- server main program

#include "server.h"

netadr_t	master_adr[MAX_MASTERS];	// address of group servers

client_t	*sv_client;			// current client

cvar_t	*sv_paused;
cvar_t	*sv_timedemo;

cvar_t	*sv_enforcetime;

cvar_t	*timeout;				// seconds without any message
cvar_t	*zombietime;			// seconds to sink messages after disconnect

cvar_t	*rcon_password;			// password for remote server commands

cvar_t	*allow_download;
cvar_t	*allow_download_players;
cvar_t	*allow_download_models;
cvar_t	*allow_download_sounds;
cvar_t	*allow_download_maps;
cvar_t	*allow_download_pics;
cvar_t	*allow_download_textures;
// Knightmare- whether to allow downloading 24-bit textures
cvar_t	*allow_download_textures_24bit;

cvar_t	*sv_downloadserver;		// from R1Q2

cvar_t	*sv_baselines_maxlen;	// Knightmare- max packet size for connect messages
cvar_t	*sv_limit_msglen;		// Knightmare- whether to use MAX_MSGLEN_MP for multiplayer games

cvar_t	*sv_airaccelerate;

cvar_t	*sv_noreload;			// don't reload level state when reentering

cvar_t	*maxclients;			// FIXME: rename sv_maxclients
cvar_t	*sv_showclamp;

cvar_t	*hostname;
cvar_t	*public_server;			// should heartbeats be sent

cvar_t	*sv_iplimit;			// r1ch: max connections from a single IP (prevent DoS)

cvar_t	*sv_reconnect_limit;	// minimum seconds between connect messages

cvar_t	*sv_entfile;			// whether to use .ent file

void Master_Shutdown (void);


//============================================================================


/*
=====================
SV_DropClient

Called when the player is totally leaving the server, either willingly
or unwillingly.  This is NOT called if the entire server is quiting
or crashing.
=====================
*/
void SV_DropClient (client_t *drop)
{
	// add the disconnect
	MSG_WriteByte (&drop->netchan.message, svc_disconnect);

	if (drop->state == cs_spawned)
	{
		// call the prog function for removing a client
		// this will remove the body, among other things
		ge->ClientDisconnect (drop->edict);
	}

	if (drop->download)
	{
		FS_FreeFile (drop->download);
		drop->download = NULL;
	}

	// r1ch: fix for mods that don't clean score
	if (drop->edict && drop->edict->client)
		drop->edict->client->ps.stats[STAT_FRAGS] = 0;

	drop->state = cs_zombie;		// become free in a few seconds
	drop->name[0] = 0;
}


//Knightmare added
/*
=====================
GetClientFromAdr

Given an netadr_t, returns the matching client.
=====================
*/
client_t *GetClientFromAdr (netadr_t address)
{
	client_t	*cl;
	int			i;
	qboolean	found = false;

	for (i = 0; i < maxclients->value; i++)
	{
		cl = &svs.clients[i];
		if (NET_CompareBaseAdr(cl->netchan.remote_address, address)) {
			found = true; break; }
	}
	if (found)
		return cl;
	else // don't return non-matching client
		return NULL;
}


/*
=====================
SV_DropClientFromAdr

Calls SV_DropClient, takes netadr_t instead of client pointer.
=====================
*/
void SV_DropClientFromAdr (netadr_t address)
{	// adapted Pat Aftermoon's simplified version of this
	client_t *drop = GetClientFromAdr(address);

	if (!drop)	return; // make sure we have a client to drop

	SV_BroadcastPrintf (PRINT_HIGH, "dropping client %s\n", drop->name);

	SV_DropClient (drop);

	drop->state = cs_free;   // don't bother with zombie state 
}
// end Knightmare

/*
=====================
SV_KickClient

From R1Q2
=====================
*/
void SV_KickClient (client_t *cl, const char *reason, const char *cprintf)
{
	if (reason && cl->state == cs_spawned && cl->name[0])
		SV_BroadcastPrintf (PRINT_HIGH, "%s was dropped: %s\n", cl->name, reason);
	if (cprintf)
		SV_ClientPrintf (cl, PRINT_HIGH, "%s", cprintf);
	Com_Printf ("Dropping %s, %s.\n", cl->name, reason ? reason : "SV_KickClient");
	SV_DropClient (cl);
}


/*
=====================
SV_CleanClient

From R1Q2
r1ch: this does the final cleaning up of a client after zombie state.
=====================
*/
void SV_CleanClient (client_t *drop)
{
	if (drop->download)
	{
		Z_Free (drop->download);
		drop->download = NULL;
	}
}

/*
==============================================================================

CONNECTIONLESS COMMANDS

==============================================================================
*/

/*
===============
SV_StatusString

Builds the string that is sent as heartbeats and status replies
===============
*/
char	*SV_StatusString (void)
{
	char	player[1024];
	static char	status[MAX_MSGLEN - 16];
	int		i;
	client_t	*cl;
	int		statusLength;
	int		playerLength;

//	strncpy (status, Cvar_Serverinfo());
//	strncat (status, "\n");
	Q_strncpyz (status, Cvar_Serverinfo(), sizeof(status));
	Q_strncatz (status, "\n", sizeof(status));
	statusLength = (int)strlen(status);

	for (i=0 ; i<maxclients->value ; i++)
	{
		cl = &svs.clients[i];
		if (cl->state == cs_connected || cl->state == cs_spawned )
		{
			Com_sprintf (player, sizeof(player), "%i %i \"%s\"\n", 
				cl->edict->client->ps.stats[STAT_FRAGS], cl->ping, cl->name);
			playerLength = (int)strlen(player);
			if (statusLength + playerLength >= sizeof(status) )
				break;		// can't hold any more
		//	strncpy (status + statusLength, player);
			Q_strncpyz (status + statusLength, player, sizeof(status));
			statusLength += playerLength;
		}
	}

	return status;
}

/*
================
SVC_Status

Responds with all the info that qplug or qspy can see
================
*/
void SVC_Status (void)
{
	Netchan_OutOfBandPrint (NS_SERVER, net_from, "print\n%s", SV_StatusString());
#if 0
	Com_BeginRedirect (RD_PACKET, sv_outputbuf, SV_OUTPUTBUF_LENGTH, SV_FlushRedirect);
	Com_Printf (SV_StatusString());
	Com_EndRedirect ();
#endif
}

/*
================
SVC_Ack

================
*/
void SVC_Ack (void)
{
	Com_Printf ("Ping acknowledge from %s\n", NET_AdrToString(net_from));
}

/*
================
SVC_Info

Responds with short info for broadcast scans
The second parameter should be the current protocol version number.
================
*/
void SVC_Info (void)
{
	char	string[64];
	int		i, count;
	int		version;

	if (maxclients->value == 1)
		return;		// ignore in single player

	version = atoi (Cmd_Argv(1));

	if (version != PROTOCOL_VERSION)
	{	// According to r1ch, this can be used to make servers endlessly ping each other
	//	Com_sprintf (string, sizeof(string), "%s: wrong version\n", hostname->string, sizeof(string));
		return;
	}
	else
	{
		count = 0;
		for (i=0 ; i<maxclients->value ; i++)
			if (svs.clients[i].state >= cs_connected)
				count++;

		Com_sprintf (string, sizeof(string), "%16s %8s %2i/%2i\n", hostname->string, sv.name, count, (int)maxclients->value);
	}

	Netchan_OutOfBandPrint (NS_SERVER, net_from, "info\n%s", string);
}

/*
================
SVC_Ping

Just responds with an acknowledgement
================
*/
void SVC_Ping (void)
{
	Netchan_OutOfBandPrint (NS_SERVER, net_from, "ack");
}


/*
=================
SVC_GetChallenge

Returns a challenge number that can be used
in a subsequent client_connect command.
We do this to prevent denial of service attacks that
flood the server with invalid connection IPs.  With a
challenge, they must give a valid IP address.
=================
*/
void SVC_GetChallenge (void)
{
	int		i;
	int		oldest;
	int		oldestTime;

	oldest = 0;
	oldestTime = 0x7fffffff;

	// see if we already have a challenge for this ip
	for (i = 0 ; i < MAX_CHALLENGES ; i++)
	{
		if (NET_CompareBaseAdr (net_from, svs.challenges[i].adr))
			break;
		if (svs.challenges[i].time < oldestTime)
		{
			oldestTime = svs.challenges[i].time;
			oldest = i;
		}
	}

	if (i == MAX_CHALLENGES)
	{
		// overwrite the oldest
		svs.challenges[oldest].challenge = rand() & 0x7fff;
		svs.challenges[oldest].adr = net_from;
		svs.challenges[oldest].time = curtime;
		i = oldest;
	}

	// send it back
	Netchan_OutOfBandPrint (NS_SERVER, net_from, "challenge %i", svs.challenges[i].challenge);
}

/*
==================
SVC_DirectConnect

A connection request that did not come from the master
==================
*/
void SVC_DirectConnect (void)
{
	char		userinfo[MAX_INFO_STRING];
	netadr_t	adr;
	int			i;
	client_t	*cl, *newcl;
	client_t	temp;
	edict_t		*ent;
	int			edictnum;
	int			version;
	int			qport;
	int			challenge;
	int			previousclients;	// rich: connection limit per IP

	adr = net_from;

	Com_DPrintf ("SVC_DirectConnect ()\n");

	version = atoi(Cmd_Argv(1));
	if (version != PROTOCOL_VERSION)
	{
		Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nServer is version %4.2f.\n", VERSION);
		Com_DPrintf ("    rejected connect from version %i\n", version);
		return;
	}

	qport = atoi(Cmd_Argv(2));

	challenge = atoi(Cmd_Argv(3));

	// r1ch: limit connections from a single IP
	previousclients = 0;
	for (i=0,cl=svs.clients; i<(int)maxclients->value; i++,cl++)
	{
		if (cl->state == cs_free)
			continue;
		if (NET_CompareBaseAdr (adr, cl->netchan.remote_address))
		{
			// r1ch: zombies are less dangerous
			if (cl->state == cs_zombie)
				previousclients++;
			else
				previousclients += 2;
		}
	}
	if (previousclients >= (int)sv_iplimit->value * 2)
	{
		Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nToo many connections from your host.\n");
		Com_DPrintf ("    too many connections\n");
		return;
	}
	// end r1ch fix

	strncpy (userinfo, Cmd_Argv(4), sizeof(userinfo)-1);
	userinfo[sizeof(userinfo) - 1] = 0;

	// force the IP key/value pair so the game can filter based on ip
	Info_SetValueForKey (userinfo, "ip", NET_AdrToString(net_from));

	// attractloop servers are ONLY for local clients
	if (sv.attractloop)
	{
		if (!NET_IsLocalAddress (adr))
		{
			Com_Printf ("Remote connect in attract loop.  Ignored.\n");
			Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nConnection refused.\n");
			return;
		}
	}

	// see if the challenge is valid
	if (!NET_IsLocalAddress (adr))
	{
		for (i=0 ; i<MAX_CHALLENGES ; i++)
		{
			if (NET_CompareBaseAdr (net_from, svs.challenges[i].adr))
			{
				if (challenge == svs.challenges[i].challenge)
					break;		// good
				Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nBad challenge.\n");
				return;
			}
		}
		if (i == MAX_CHALLENGES)
		{
			Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nNo challenge for address.\n");
			return;
		}
	}

	newcl = &temp;
	memset (newcl, 0, sizeof(client_t));

	// if there is already a slot for this ip, reuse it
	for (i=0,cl=svs.clients ; i<maxclients->value ; i++,cl++)
	{
		if (cl->state == cs_free)
			continue;
		if (NET_CompareBaseAdr (adr, cl->netchan.remote_address)
			&& ( cl->netchan.qport == qport 
			|| adr.port == cl->netchan.remote_address.port ) )
		{
			if (!NET_IsLocalAddress (adr) && (svs.realtime - cl->lastconnect) < ((int)sv_reconnect_limit->value * 1000))
			{
				Com_DPrintf ("%s:reconnect rejected : too soon\n", NET_AdrToString (adr));
				return;
			}
			// r1ch: !! fix nasty bug where non-disconnected clients (from dropped disconnect
			// packets) could be overwritten!
			if (cl->state != cs_zombie)
			{
				Com_DPrintf ("    client already found\n");
				// If we legitly get here, spoofed udp isn't possible (passed challenge) and client addr/port combo
				// is exactly the same, so we can assume its really a dropped/crashed client. i hope...
				Com_Printf ("Dropping %s, ghost reconnect\n", cl->name);
				SV_DropClient (cl);
			}
			// end r1ch fix

			Com_Printf ("%s:reconnect\n", NET_AdrToString (adr));

			SV_CleanClient (cl);	// r1ch: clean up last client data

			newcl = cl;
			goto gotnewcl;
		}
	}

	// find a client slot
	newcl = NULL;
	for (i=0,cl=svs.clients ; i<maxclients->value ; i++,cl++)
	{
		if (cl->state == cs_free)
		{
			newcl = cl;
			break;
		}
	}
	if (!newcl)
	{
		Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nServer is full.\n");
		Com_DPrintf ("Rejected a connection.\n");
		return;
	}

gotnewcl:	
	// build a new connection
	// accept the new client
	// this is the only place a client_t is ever initialized
	*newcl = temp;
	sv_client = newcl;
	edictnum = (newcl-svs.clients)+1;
	ent = EDICT_NUM(edictnum);
	newcl->edict = ent;
	newcl->challenge = challenge; // save challenge for checksumming

	// get the game a chance to reject this connection or modify the userinfo
	if (!(ge->ClientConnect (ent, userinfo)))
	{
		if (*Info_ValueForKey (userinfo, "rejmsg")) 
			Netchan_OutOfBandPrint (NS_SERVER, adr, "print\n%s\nConnection refused.\n",  
				Info_ValueForKey (userinfo, "rejmsg"));
		else
			Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nConnection refused.\n" );
		Com_DPrintf ("Game rejected a connection.\n");
		return;
	}

	// parse some info from the info strings
	strncpy (newcl->userinfo, userinfo, sizeof(newcl->userinfo)-1);
	SV_UserinfoChanged (newcl);

	// send the connect packet to the client
	// r1ch: note we could ideally send this twice but it prints unsightly message on original client.
	if (sv_downloadserver->string[0])
		Netchan_OutOfBandPrint (NS_SERVER, adr, "client_connect dlserver=%s", sv_downloadserver->string);
	else
		Netchan_OutOfBandPrint (NS_SERVER, adr, "client_connect");

	Netchan_Setup (NS_SERVER, &newcl->netchan , adr, qport);

	newcl->state = cs_connected;
	
	SZ_Init (&newcl->datagram, newcl->datagram_buf, sizeof(newcl->datagram_buf) );
	newcl->datagram.allowoverflow = true;
	newcl->lastmessage = svs.realtime;	// don't timeout
	newcl->lastconnect = svs.realtime;
}

int Rcon_Validate (void)
{
	if (!strlen (rcon_password->string))
		return 0;

	if (strcmp (Cmd_Argv(1), rcon_password->string) )
		return 0;

	return 1;
}

/*
===============
SVC_RemoteCommand

A client issued an rcon command.
Shift down the remaining args
Redirect all printfs
===============
*/
void SVC_RemoteCommand (void)
{
	int		i;
	char	remaining[1024];

	i = Rcon_Validate ();

	if (i == 0)
		Com_Printf ("Bad rcon from %s:\n%s\n", NET_AdrToString (net_from), net_message.data+4);
	else
		Com_Printf ("Rcon from %s:\n%s\n", NET_AdrToString (net_from), net_message.data+4);

	Com_BeginRedirect (RD_PACKET, sv_outputbuf, SV_OUTPUTBUF_LENGTH, SV_FlushRedirect);

	if (!Rcon_Validate ())
	{
		Com_Printf ("Bad rcon_password.\n");
	}
	else
	{
		remaining[0] = 0;

		for (i=2 ; i<Cmd_Argc() ; i++)
		{
			strcat (remaining, Cmd_Argv(i) );
			strcat (remaining, " ");
		}

		Cmd_ExecuteString (remaining);
	}

	Com_EndRedirect ();
}

/*
=================
SV_ConnectionlessPacket

A connectionless packet has four leading 0xff
characters to distinguish it from a game channel.
Clients that are in the game can still send
connectionless packets.
=================
*/
void SV_ConnectionlessPacket (void)
{
	char	*s;
	char	*c;

	// r1ch fix: make sure we never talk to ourselves
//	if (NET_IsLocalAddress (net_from.ip[0] == 127) && !NET_IsLocalHost(net_from) && ShortSwap(net_from.port) == server_port)
/*	if ( (net_from.ip[0] == 127) && (net_from.type != NA_LOOPBACK) && (ShortSwap(net_from.port) == server_port) )
	{
		Com_DPrintf ("dropped %d byte connectionless packet from self! (spoofing attack?)\n", net_message.cursize);
		return;
	}*/

	MSG_BeginReading (&net_message);
	MSG_ReadLong (&net_message);		// skip the -1 marker

	s = MSG_ReadStringLine (&net_message);

	Cmd_TokenizeString (s, false);

	c = Cmd_Argv(0);
	Com_DPrintf ("Packet %s : %s\n", NET_AdrToString(net_from), c);

	if (!strcmp(c, "ping"))
		SVC_Ping ();
	else if (!strcmp(c, "ack"))
		SVC_Ack ();
	else if (!strcmp(c,"status"))
		SVC_Status ();
	else if (!strcmp(c,"info"))
		SVC_Info ();
	else if (!strcmp(c,"getchallenge"))
		SVC_GetChallenge ();
	else if (!strcmp(c,"connect"))
		SVC_DirectConnect ();
	else if (!strcmp(c, "rcon"))
		SVC_RemoteCommand ();
	else
		Com_Printf ("bad connectionless packet from %s:\n%s\n"
		, NET_AdrToString (net_from), s);
}


//============================================================================

/*
===================
SV_CalcPings

Updates the cl->ping variables
===================
*/
void SV_CalcPings (void)
{
	int			i, j;
	client_t	*cl;
	int			total, count;

	for (i=0 ; i<maxclients->value ; i++)
	{
		cl = &svs.clients[i];
		if (cl->state != cs_spawned )
			continue;

#if 0
		if (cl->lastframe > 0)
			cl->frame_latency[sv.framenum&(LATENCY_COUNTS-1)] = sv.framenum - cl->lastframe + 1;
		else
			cl->frame_latency[sv.framenum&(LATENCY_COUNTS-1)] = 0;
#endif

		total = 0;
		count = 0;
		for (j=0 ; j<LATENCY_COUNTS ; j++)
		{
			if (cl->frame_latency[j] > 0)
			{
				count++;
				total += cl->frame_latency[j];
			}
		}
		if (!count)
			cl->ping = 0;
		else
#if 0
			cl->ping = total*100/count - 100;
#else
			cl->ping = total / count;
#endif

		// let the game dll know about the ping
		cl->edict->client->ping = cl->ping;
	}
}


/*
===================
SV_GiveMsec

Every few frames, gives all clients an allotment of milliseconds
for their command moves.  If they exceed it, assume cheating.
===================
*/
void SV_GiveMsec (void)
{
	int			i;
	client_t	*cl;

	if (sv.framenum & 15)
		return;

	for (i=0 ; i<maxclients->value ; i++)
	{
		cl = &svs.clients[i];
		if (cl->state == cs_free )
			continue;
		
		cl->commandMsec = 1800;		// 1600 + some slop
	}
}


/*
=================
SV_ReadPackets
=================
*/
void SV_ReadPackets (void)
{
	int			i;
	client_t	*cl;
	int			qport;

	while (NET_GetPacket (NS_SERVER, &net_from, &net_message))
	{
		// check for connectionless packet (0xffffffff) first
		if (*(int *)net_message.data == -1)
		{
			SV_ConnectionlessPacket ();
			continue;
		}

		// read the qport out of the message so we can fix up
		// stupid address translating routers
		MSG_BeginReading (&net_message);
		MSG_ReadLong (&net_message);		// sequence number
		MSG_ReadLong (&net_message);		// sequence number
		qport = MSG_ReadShort (&net_message) & 0xffff;

		// check for packets from connected clients
		for (i=0, cl=svs.clients ; i<maxclients->value ; i++,cl++)
		{
			if (cl->state == cs_free)
				continue;
			if (!NET_CompareBaseAdr (net_from, cl->netchan.remote_address))
				continue;
			if (cl->netchan.qport != qport)
				continue;
			if (cl->netchan.remote_address.port != net_from.port)
			{
				Com_Printf ("SV_ReadPackets: fixing up a translated port\n");
				cl->netchan.remote_address.port = net_from.port;
			}

			if (Netchan_Process(&cl->netchan, &net_message))
			{	// this is a valid, sequenced packet, so process it
				if (cl->state != cs_zombie)
				{
					cl->lastmessage = svs.realtime;	// don't timeout
					SV_ExecuteClientMessage (cl);
				}
			}
			break;
		}
		
		if (i != maxclients->value)
			continue;
	}
}

/*
==================
SV_CheckTimeouts

If a packet has not been received from a client for timeout->value
seconds, drop the conneciton.  Server frames are used instead of
realtime to avoid dropping the local client while debugging.

When a client is normally dropped, the client_t goes into a zombie state
for a few seconds to make sure any final reliable message gets resent
if necessary
==================
*/
void SV_CheckTimeouts (void)
{
	int		i;
	client_t	*cl;
	int			droppoint;
	int			zombiepoint;

	droppoint = svs.realtime - 1000*timeout->value;
	zombiepoint = svs.realtime - 1000*zombietime->value;

	for (i=0,cl=svs.clients ; i<maxclients->value ; i++,cl++)
	{
		// message times may be wrong across a changelevel
		if (cl->lastmessage > svs.realtime)
			cl->lastmessage = svs.realtime;

		if (cl->state == cs_zombie
		&& cl->lastmessage < zombiepoint)
		{
			SV_CleanClient (cl); // r1ch fix: make sure client is cleaned up
			cl->state = cs_free;	// can now be reused
			continue;
		}
		if ( (cl->state == cs_connected || cl->state == cs_spawned) 
			&& cl->lastmessage < droppoint)
		{
			// r1ch fix: only message if they spawned (less spam plz)
			if (cl->state == cs_spawned && cl->name[0])
				SV_BroadcastPrintf (PRINT_HIGH, "%s timed out\n", cl->name);
			SV_DropClient (cl); 
			cl->state = cs_free;	// don't bother with zombie state
		}
	}
}

/*
================
SV_PrepWorldFrame

This has to be done before the world logic, because
player processing happens outside RunWorldFrame
================
*/
void SV_PrepWorldFrame (void)
{
	edict_t	*ent;
	int		i;

	for (i=0 ; i<ge->num_edicts ; i++, ent++)
	{
		ent = EDICT_NUM(i);
		// events only last for a single message
		ent->s.event = 0;
	}

}


/*
=================
SV_RunGameFrame
=================
*/
void SV_RunGameFrame (void)
{
	if (host_speeds->value)
		time_before_game = Sys_Milliseconds ();

	// we always need to bump framenum, even if we
	// don't run the world, otherwise the delta
	// compression can get confused when a client
	// has the "current" frame
	sv.framenum++;
	sv.time = sv.framenum*100;

	// don't run if paused
	if (!sv_paused->value || maxclients->value > 1)
	{
		ge->RunFrame ();

		// never get more than one tic behind
		if (sv.time < svs.realtime)
		{
			if (sv_showclamp->value)
				Com_Printf ("sv highclamp\n");
			svs.realtime = sv.time;
		}
	}

	if (host_speeds->value)
		time_after_game = Sys_Milliseconds ();

}

/*
==================
SV_Frame

==================
*/
void SV_Frame (int msec)
{
	time_before_game = time_after_game = 0;

	// if server is not active, do nothing
	if (!svs.initialized)
		return;

    svs.realtime += msec;

	// keep the random time dependent
	rand ();

	// check timeouts
	SV_CheckTimeouts ();

	// get packets from clients
	SV_ReadPackets ();

	// move autonomous things around if enough time has passed
	if (!sv_timedemo->value && svs.realtime < sv.time)
	{
		// never let the time get too far off
		if (sv.time - svs.realtime > 100)
		{
			if (sv_showclamp->value)
				Com_Printf ("sv lowclamp\n");
			svs.realtime = sv.time - 100;
		}
		NET_Sleep(sv.time - svs.realtime);
		return;
	}

	// update ping based on the last known frame from all clients
	SV_CalcPings ();

	// give the clients some timeslices
	SV_GiveMsec ();

	// let everything in the world think and move
	SV_RunGameFrame ();

	// send messages back to the clients that had packets read this frame
	SV_SendClientMessages ();

	// save the entire world state if recording a serverdemo
	SV_RecordDemoMessage ();

	// send a heartbeat to the master if needed
	Master_Heartbeat ();

	// clear teleport flags, etc for next frame
	SV_PrepWorldFrame ();

}

//============================================================================

/*
================
Master_Heartbeat

Send a message to the master every few minutes to
let it know we are alive, and log information
================
*/
#define	HEARTBEAT_SECONDS	300
void Master_Heartbeat (void)
{
	char		*string;
	int			i;

	// pgm post 3.19 change, cvar pointer not validated before dereferencing
	if (!dedicated || !dedicated->value)
		return;		// only dedicated servers send heartbeats

	// pgm post 3.19 change, cvar pointer not validated before dereferencing
	if (!public_server || !public_server->value)
		return;		// a private dedicated game

	// check for time wraparound
	if (svs.last_heartbeat > svs.realtime)
		svs.last_heartbeat = svs.realtime;

	if (svs.realtime - svs.last_heartbeat < HEARTBEAT_SECONDS*1000)
		return;		// not time to send yet

	svs.last_heartbeat = svs.realtime;

	// send the same string that we would give for a status OOB command
	string = SV_StatusString();

	// send to group master
	for (i=0 ; i<MAX_MASTERS ; i++)
		if (master_adr[i].port)
		{
			Com_Printf ("Sending heartbeat to %s\n", NET_AdrToString (master_adr[i]));
			Netchan_OutOfBandPrint (NS_SERVER, master_adr[i], "heartbeat\n%s", string);
		}
}

/*
=================
Master_Shutdown

Informs all masters that this server is going down
=================
*/
void Master_Shutdown (void)
{
	int			i;

	// pgm post3.19 change, cvar pointer not validated before dereferencing
	if (!dedicated || !dedicated->value)
		return;		// only dedicated servers send heartbeats

	// pgm post3.19 change, cvar pointer not validated before dereferencing
	if (!public_server || !public_server->value)
		return;		// a private dedicated game

	// send to group master
	for (i=0 ; i<MAX_MASTERS ; i++)
		if (master_adr[i].port)
		{
			if (i > 0)
				Com_Printf ("Sending heartbeat to %s\n", NET_AdrToString (master_adr[i]));
			Netchan_OutOfBandPrint (NS_SERVER, master_adr[i], "shutdown");
		}
}

//============================================================================


/*
=================
SV_UserinfoChanged

Pull specific info from a newly changed userinfo string
into a more C freindly form.
=================
*/
void SV_UserinfoChanged (client_t *cl)
{
	char	*val;
	int		i;

	// call prog code to allow overrides
	ge->ClientUserinfoChanged (cl->edict, cl->userinfo);
	
	// name for C code
	strncpy (cl->name, Info_ValueForKey (cl->userinfo, "name"), sizeof(cl->name)-1);
	// mask off high bit
	for (i=0 ; i<sizeof(cl->name) ; i++)
		cl->name[i] &= 127;

	// rate command
	val = Info_ValueForKey (cl->userinfo, "rate");
	if (strlen(val))
	{
		i = atoi(val);
		cl->rate = i;
		if (cl->rate < 100)
			cl->rate = 100;
		if (cl->rate > 15000)
			cl->rate = 15000;
	}
	else
		cl->rate = 5000;

	// msg command
	val = Info_ValueForKey (cl->userinfo, "msg");
	if (strlen(val))
	{
		cl->messagelevel = atoi(val);
	}

}


//============================================================================

/*
===============
SV_Init

Only called at quake2.exe startup, not for each game
===============
*/
void SV_Init (void)
{
	SV_InitOperatorCommands	();

	rcon_password = Cvar_Get ("rcon_password", "", 0);
	Cvar_SetDescription ("rcon_password", "Sets password for rcon commands.");
	Cvar_Get ("skill", "1", 0);
	Cvar_SetDescription ("skill", "Sets skill level. 0 = Easy, 1 = Medium, 2 = Hard, 3 = Nightmare.");
	Cvar_Get ("deathmatch", "0", CVAR_LATCH);
	Cvar_SetDescription ("deathmatch", "Enables non-coop multiplayer.  This is enabled for both Deathmatch and CTF.");
	Cvar_Get ("coop", "0", CVAR_LATCH);
	Cvar_SetDescription ("coop", "Enables cooperative multiplayer.");
	Cvar_Get ("dmflags", va("%i", DF_INSTANT_ITEMS), CVAR_SERVERINFO);
	Cvar_SetDescription ("dmflags", "Bitfield for deathmatch options.  Options and values vary by mod.");
	Cvar_Get ("fraglimit", "0", CVAR_SERVERINFO);
	Cvar_SetDescription ("fraglimit", "Number of frags reached in Deathmatch that triggers a map change.");
	Cvar_Get ("timelimit", "0", CVAR_SERVERINFO);
	Cvar_SetDescription ("timelimit", "Time in minutes between Deathmatch map changes.");
	Cvar_Get ("cheats", "0", CVAR_SERVERINFO|CVAR_LATCH);
	Cvar_SetDescription ("cheats", "Enables cheat codes in multiplayer games.");
	Cvar_Get ("protocol", va("%i", PROTOCOL_VERSION), CVAR_SERVERINFO|CVAR_NOSET);;
	Cvar_SetDescription ("protocol", "Protocol version for this server.");
	maxclients = Cvar_Get ("maxclients", "1", CVAR_SERVERINFO | CVAR_LATCH);
	Cvar_SetDescription ("maxclients", "Maximum number of players allowed on this server.");
	hostname = Cvar_Get ("hostname", "noname", CVAR_SERVERINFO | CVAR_ARCHIVE);
	Cvar_SetDescription ("hostname", "Name of this server visible to clients.");
	timeout = Cvar_Get ("timeout", "125", 0);
	Cvar_SetDescription ("timeout", "Time in seconds after which non-responsive clients are dropped.");
	zombietime = Cvar_Get ("zombietime", "2", 0);
	Cvar_SetDescription ("zombietime", "Time in seconds which client slots are kept in zombie state.");
	sv_showclamp = Cvar_Get ("showclamp", "0", 0);
	Cvar_SetDescription ("showclamp", "Enables output of high and low frame clamps.");
	sv_paused = Cvar_Get ("paused", "0", 0);
	Cvar_SetDescription ("paused", "Value that determines if the game is paused.  Considered a client cheat in multiplayer.");
	sv_timedemo = Cvar_Get ("timedemo", "0", 0);
	Cvar_SetDescription ("timedemo", "Set to 1 for timing playback of demos.  Useful for old-school bencmarking.");
	sv_enforcetime = Cvar_Get ("sv_enforcetime", "0", 0);
	Cvar_SetDescription ("sv_enforcetime", "Enables check for underflow of client command time.");
	allow_download = Cvar_Get ("allow_download", "1", CVAR_ARCHIVE);
	Cvar_SetDescription ("allow_download", "Enables autodownload of game assets in multiplayer.");
	allow_download_players  = Cvar_Get ("allow_download_players", "0", CVAR_ARCHIVE);
	Cvar_SetDescription ("allow_download_players", "Enables download of player models.");
	allow_download_models = Cvar_Get ("allow_download_models", "1", CVAR_ARCHIVE);
	Cvar_SetDescription ("allow_download_models", "Enables download of models.");
	allow_download_sounds = Cvar_Get ("allow_download_sounds", "1", CVAR_ARCHIVE);
	Cvar_SetDescription ("allow_download_sounds", "Enables download of sounds.");
	allow_download_maps	  = Cvar_Get ("allow_download_maps", "1", CVAR_ARCHIVE);
	Cvar_SetDescription ("allow_download_maps", "Enables download of maps.");
	allow_download_pics  = Cvar_Get ("allow_download_pics", "1", CVAR_ARCHIVE);
	Cvar_SetDescription ("allow_download_pics", "Enables download of .pcx images.");
	allow_download_textures  = Cvar_Get ("allow_download_textures", "1", CVAR_ARCHIVE);
	Cvar_SetDescription ("allow_download_textures", "Enables download of .wal textures.");
	// Knightmare- whether to allow downloading 24-bit textures
	allow_download_textures_24bit = Cvar_Get ("allow_download_textures_24bit", "0", CVAR_ARCHIVE);
	Cvar_SetDescription ("allow_download_textures_24bit", "Enables download of TGA/JPG/PNG textures.");

	sv_downloadserver = Cvar_Get ("sv_downloadserver", "", 0);	// r1ch: http dl server
	Cvar_SetDescription ("sv_downloadserver", "Sets URL of HTTP autodownload server where clients can download game content over HTTP.  Default empty.  Path leads to game dir name, e.g. quake2.com/baseq2/maps.");

	sv_baselines_maxlen = Cvar_Get ("sv_baselines_maxlen", "1200", 0);	// Knightmare- max packet size for connect messages
	Cvar_SetDescription ("sv_baselines_maxlen", "Sets max packet size for non-local network connect messages.");
	sv_limit_msglen = Cvar_Get ("sv_limit_msglen", "1", 0);				// Knightmare- whether to use MAX_MSGLEN_MP for multiplayer games
	Cvar_SetDescription ("sv_limit_msglen", "Enables limited packet size for non-local clients.");

	sv_noreload = Cvar_Get ("sv_noreload", "0", 0);
	Cvar_SetDescription ("sv_noreload", "Disables loading of savegames on map change when set to 1.");

	sv_airaccelerate = Cvar_Get("sv_airaccelerate", "0", CVAR_LATCH);
	Cvar_SetDescription ("sv_airaccelerate", "Sets client air acceleration for non-coop multiplayer games.");

	public_server = Cvar_Get ("public", "0", 0);
	Cvar_SetDescription ("public", "Sets whether this is a public server.");

	sv_iplimit = Cvar_Get ("sv_iplimit", "3", 0);	// r1ch: limit connections per ip address (stop zombie dos/flood)
	Cvar_SetDescription("sv_iplimit", "Sets connection limit per IP address.  Stops zombie DoS/Flood.");

	sv_reconnect_limit = Cvar_Get ("sv_reconnect_limit", "3", CVAR_ARCHIVE);
	Cvar_SetDescription ("sv_reconnect_limit", "Sets time in seconds before a client can reconnect.");

	sv_entfile = Cvar_Get ("sv_entfile", "1", CVAR_ARCHIVE); // whether to use .ent file
	Cvar_SetDescription ("sv_entfile", "Enables automatic loading of .ent files to replace BSP entity lump.");

	SZ_Init (&net_message, net_message_buffer, sizeof(net_message_buffer));
}

/*
==================
SV_FinalMessage

Used by SV_Shutdown to send a final message to all
connected clients before the server goes down.  The messages are sent immediately,
not just stuck on the outgoing message list, because the server is going
to totally exit after returning from this function.
==================
*/
void SV_FinalMessage (char *message, qboolean reconnect)
{
	int			i;
	client_t	*cl;
	
	SZ_Clear (&net_message);
	MSG_WriteByte (&net_message, svc_print);
	MSG_WriteByte (&net_message, PRINT_HIGH);
	MSG_WriteString (&net_message, message);

	if (reconnect)
		MSG_WriteByte (&net_message, svc_reconnect);
	else
		MSG_WriteByte (&net_message, svc_disconnect);

	// send it twice
	// stagger the packets to crutch operating system limited buffers

	for (i=0, cl = svs.clients ; i<maxclients->value ; i++, cl++)
		if (cl->state >= cs_connected)
			Netchan_Transmit (&cl->netchan, net_message.cursize
			, net_message.data);

	for (i=0, cl = svs.clients ; i<maxclients->value ; i++, cl++)
		if (cl->state >= cs_connected)
			Netchan_Transmit (&cl->netchan, net_message.cursize
			, net_message.data);
}



/*
================
SV_Shutdown

Called when each game quits,
before Sys_Quit or Sys_Error
================
*/
void SV_Shutdown (char *finalmsg, qboolean reconnect)
{
	if (svs.clients)
		SV_FinalMessage (finalmsg, reconnect);

	Master_Shutdown ();
	SV_ShutdownGameProgs ();

	// free current level
	if (sv.demofile)
		FS_FCloseFile (sv.demofile);
	memset (&sv, 0, sizeof(sv));
	Com_SetServerState (sv.state);

	// free server static data
	if (svs.clients)
		Z_Free (svs.clients);
	if (svs.client_entities)
		Z_Free (svs.client_entities);
	if (svs.demofile)
		fclose (svs.demofile);
	memset (&svs, 0, sizeof(svs));
}