/*
==================
SV_UserMove

The message usually contains all the movement commands 
that were in the last three packets, so that the information
in dropped packets can be recovered.

On very fast clients, there may be multiple usercmd packed into
each of the backup packets.
==================
*/
static void SV_UserMove( client_t *cl, msg_t *msg ) {
	int			i, start;
	int			cmdNum;
	int			firstNum;
	int			cmdCount;
	usercmd_t	nullcmd;
	usercmd_t	cmds[MAX_PACKET_USERCMDS];
	usercmd_t	*cmd, *oldcmd;
	int			clientTime;
	int			serverId;

	cl->reliableAcknowledge = MSG_ReadLong( msg );
	serverId = MSG_ReadLong( msg );
	clientTime = MSG_ReadLong( msg );
	cl->deltaMessage = MSG_ReadLong( msg );

	// cmdNum is the command number of the most recent included usercmd
	cmdNum = MSG_ReadLong( msg );
	cmdCount = MSG_ReadByte( msg );

	if ( cmdCount < 1 ) {
		Com_Printf( "cmdCount < 1\n" );
		return;
	}

	if ( cmdCount > MAX_PACKET_USERCMDS ) {
		Com_Printf( "cmdCount > MAX_PACKET_USERCMDS\n" );
		return;
	}

	memset( &nullcmd, 0, sizeof(nullcmd) );
	oldcmd = &nullcmd;
	for ( i = 0 ; i < cmdCount ; i++ ) {
		cmd = &cmds[i];
		MSG_ReadDeltaUsercmd( msg, oldcmd, cmd );
		oldcmd = cmd;
	}

	// if this is a usercmd from a previous gamestate,
	// ignore it or retransmit the current gamestate
	if ( serverId != sv.serverId ) {
		// if we can tell that the client has dropped the last
		// gamestate we sent them, resend it
		if ( cl->netchan.incomingAcknowledged > cl->gamestateMessageNum ) {
			Com_DPrintf( "%s : dropped gamestate, resending\n", cl->name );
			SV_SendClientGameState( cl );
		}
		return;
	}

	// if this is the first usercmd we have received
	// this gamestate, put the client into the world
	if ( cl->state == CS_PRIMED ) {

		SV_ClientEnterWorld( cl, &cmds[0], eSavedGameJustLoaded );
#ifndef _XBOX	// No auto-saving for now?
		if ( sv_mapname->string[0]!='_' )
		{
			char savename[MAX_QPATH];
			if ( eSavedGameJustLoaded == eNO )
			{
				SG_WriteSavegame("auto",qtrue);
				if ( strnicmp(sv_mapname->string, "academy", 7) != 0)
				{
					Com_sprintf (savename, sizeof(savename), "auto_%s",sv_mapname->string);
					SG_WriteSavegame(savename,qtrue);//can't use va becuase it's nested
				}
			}
			else if ( qbLoadTransition == qtrue )
			{
				Com_sprintf (savename, sizeof(savename), "hub/%s", sv_mapname->string );
				SG_WriteSavegame( savename, qfalse );//save a full one
				SG_WriteSavegame( "auto", qfalse );//need a copy for auto, too
			}
		}
#endif
		eSavedGameJustLoaded = eNO;
		// the moves can be processed normaly
	}

	if ( cl->state != CS_ACTIVE ) {
		cl->deltaMessage = -1;
		return;
	}


	// if there is a time gap from the last packet to this packet,
	// fill in with the first command in the packet
//.........这里部分代码省略.........

//.........这里部分代码省略.........

	//
	// parse the pmove_state_t
	//
	if (flags & PS_M_TYPE)
		state->pmove.pm_type = MSG_ReadByte(&net_message);

	if (flags & PS_M_ORIGIN)
	{
		state->pmove.origin[0] = MSG_ReadShort (&net_message);
		state->pmove.origin[1] = MSG_ReadShort (&net_message);
		state->pmove.origin[2] = MSG_ReadShort (&net_message);
	}

	if (flags & PS_M_VELOCITY)
	{
		state->pmove.velocity[0] = MSG_ReadShort (&net_message);
		state->pmove.velocity[1] = MSG_ReadShort (&net_message);
		state->pmove.velocity[2] = MSG_ReadShort (&net_message);
	}

	if (flags & PS_M_TIME)
		state->pmove.pm_time = MSG_ReadByte(&net_message);

	if (flags & PS_M_FLAGS)
		state->pmove.pm_flags = MSG_ReadByte(&net_message);

	if (flags & PS_M_GRAVITY)
		state->pmove.gravity = MSG_ReadShort (&net_message);

	if (flags & PS_M_DELTA_ANGLES)
	{
		state->pmove.delta_angles[0] = MSG_ReadShort (&net_message);
		state->pmove.delta_angles[1] = MSG_ReadShort (&net_message);
		state->pmove.delta_angles[2] = MSG_ReadShort (&net_message);
	}

	if (cl.attractloop)
		state->pmove.pm_type = PM_FREEZE;		// demo playback

	//
	// parse the rest of the player_state_t
	//
	if (flags & PS_VIEWOFFSET)
	{
		state->viewoffset[0] = MSG_ReadChar(&net_message) * 0.25;
		state->viewoffset[1] = MSG_ReadChar(&net_message) * 0.25;
		state->viewoffset[2] = MSG_ReadChar(&net_message) * 0.25;
	}

	if (flags & PS_VIEWANGLES)
	{
		state->viewangles[0] = MSG_ReadAngle16(&net_message);
		state->viewangles[1] = MSG_ReadAngle16(&net_message);
		state->viewangles[2] = MSG_ReadAngle16(&net_message);
	}

	if (flags & PS_KICKANGLES)
	{
		state->kick_angles[0] = MSG_ReadChar(&net_message) * 0.25;
		state->kick_angles[1] = MSG_ReadChar(&net_message) * 0.25;
		state->kick_angles[2] = MSG_ReadChar(&net_message) * 0.25;
	}

	if (flags & PS_WEAPONINDEX)
	{
		state->gunindex = MSG_ReadByte(&net_message);
	}

	if (flags & PS_WEAPONFRAME)
	{
		state->gunframe = MSG_ReadByte(&net_message);
		state->gunoffset[0] = MSG_ReadChar(&net_message)*0.25;
		state->gunoffset[1] = MSG_ReadChar(&net_message)*0.25;
		state->gunoffset[2] = MSG_ReadChar(&net_message)*0.25;
		state->gunangles[0] = MSG_ReadChar(&net_message)*0.25;
		state->gunangles[1] = MSG_ReadChar(&net_message)*0.25;
		state->gunangles[2] = MSG_ReadChar(&net_message)*0.25;
	}

	if (flags & PS_BLEND)
	{
		state->blend[0] = MSG_ReadByte(&net_message)*0.003921568627450980392156862745098;
		state->blend[1] = MSG_ReadByte(&net_message)*0.003921568627450980392156862745098;
		state->blend[2] = MSG_ReadByte(&net_message)*0.003921568627450980392156862745098;
		state->blend[3] = MSG_ReadByte(&net_message)*0.003921568627450980392156862745098;
	}

	if (flags & PS_FOV)
		state->fov = MSG_ReadByte(&net_message);

	if (flags & PS_RDFLAGS)
		state->rdflags = MSG_ReadByte(&net_message);

	// parse stats
	statbits = MSG_ReadLong (&net_message);
	for (i=0 ; i<MAX_STATS ; i++)
		if (statbits & (1<<i) )
			state->stats[i] = MSG_ReadShort(&net_message);
}

/*
==================
CL_ParseDelta

Can go from either a baseline or a previous packet_entity
==================
*/
void CL_ParseDelta (entity_state_t *from, entity_state_t *to, int number, int bits)
{
	// set everything to the state we are delta'ing from
	*to = *from;

	VectorCopy(from->origin, to->old_origin);
	to->number = number;

	if (bits & U_MODEL)
		to->modelindex = MSG_ReadByte(&net_message);

	if (bits & U_MODEL2)
		to->modelindex2 = MSG_ReadByte(&net_message);

	if (bits & U_MODEL3)
		to->modelindex3 = MSG_ReadByte(&net_message);

	if (bits & U_MODEL4)
		to->modelindex4 = MSG_ReadByte(&net_message);
		
	if (bits & U_FRAME8)
		to->frame = MSG_ReadByte(&net_message);

	if (bits & U_FRAME16)
		to->frame = MSG_ReadShort(&net_message);

	assert(to->skinnum >= 0); // jitdebug

	if ((bits & U_SKIN8) && (bits & U_SKIN16))		//used for laser colors
		to->skinnum = MSG_ReadLong(&net_message);
	else if (bits & U_SKIN8)
		to->skinnum = MSG_ReadByte(&net_message);
	else if (bits & U_SKIN16)
		to->skinnum = MSG_ReadShort(&net_message);

	assert(to->skinnum >= 0);

	if ((bits & (U_EFFECTS8|U_EFFECTS16)) == (U_EFFECTS8|U_EFFECTS16))
		to->effects = MSG_ReadLong(&net_message);
	else if (bits & U_EFFECTS8)
		to->effects = MSG_ReadByte(&net_message);
	else if (bits & U_EFFECTS16)
		to->effects = MSG_ReadShort(&net_message);

	if ((bits & (U_RENDERFX8|U_RENDERFX16)) == (U_RENDERFX8|U_RENDERFX16))
		to->renderfx = MSG_ReadLong(&net_message);
	else if (bits & U_RENDERFX8)
		to->renderfx = MSG_ReadByte(&net_message);
	else if (bits & U_RENDERFX16)
		to->renderfx = MSG_ReadShort(&net_message);

	if (bits & U_ORIGIN1)
		to->origin[0] = MSG_ReadCoord(&net_message);

	if (bits & U_ORIGIN2)
		to->origin[1] = MSG_ReadCoord(&net_message);

	if (bits & U_ORIGIN3)
		to->origin[2] = MSG_ReadCoord(&net_message);
		
	if (bits & U_ANGLE1)
		to->angles[0] = MSG_ReadAngle(&net_message);

	if (bits & U_ANGLE2)
		to->angles[1] = MSG_ReadAngle(&net_message);

	if (bits & U_ANGLE3)
		to->angles[2] = MSG_ReadAngle(&net_message);

	if (bits & U_OLDORIGIN)
		MSG_ReadPos(&net_message, to->old_origin);

	if (bits & U_SOUND)
		to->sound = MSG_ReadByte(&net_message);

	if (bits & U_EVENT)
		to->event = MSG_ReadByte(&net_message);
	else
		to->event = 0;

	if (bits & U_SOLID)
		to->solid = MSG_ReadShort(&net_message);
}

/*
=================
Netchan_Process

Returns qfalse if the message should not be processed due to being
out of order or a fragment.

Msg must be large enough to hold MAX_MSGLEN, because if this is the
final fragment of a multi-part message, the entire thing will be
copied out.
=================
*/
qboolean Netchan_Process( netchan_t *chan, msg_t *msg ) {
	int			sequence;
	//int			qport;
	int			fragmentStart, fragmentLength;
	qboolean	fragmented;

	// get sequence numbers
	MSG_BeginReadingOOB( msg );
	sequence = MSG_ReadLong( msg );

	// check for fragment information
	if ( sequence & FRAGMENT_BIT ) {
		sequence &= ~FRAGMENT_BIT;
		fragmented = qtrue;
	} else {
		fragmented = qfalse;
	}

	// read the qport if we are a server
	if ( chan->sock == NS_SERVER ) {
		/*qport = */MSG_ReadShort( msg );
	}

	// read the fragment information
	if ( fragmented ) {
		fragmentStart  = (unsigned short)MSG_ReadShort( msg );
		fragmentLength = (unsigned short)MSG_ReadShort( msg );
	} else {
		fragmentStart = 0;		// stop warning message
		fragmentLength = 0;
	}

	if ( showpackets->integer ) {
		if ( fragmented ) {
			Com_Printf( "%s recv %4i : s=%i fragment=%i,%i\n"
				, netsrcString[ chan->sock ]
				, msg->cursize
				, sequence
				, fragmentStart, fragmentLength );
		} else {
			Com_Printf( "%s recv %4i : s=%i\n"
				, netsrcString[ chan->sock ]
				, msg->cursize
				, sequence );
		}
	}

	//
	// discard out of order or duplicated packets
	//
	if ( sequence <= chan->incomingSequence ) {
		if ( showdrop->integer || showpackets->integer ) {
			Com_Printf( "%s:Out of order packet %i at %i\n"
				, NET_AdrToString( chan->remoteAddress )
				,  sequence
				, chan->incomingSequence );
		}
		return qfalse;
	}

	//
	// dropped packets don't keep the message from being used
	//
	chan->dropped = sequence - (chan->incomingSequence+1);
	if ( chan->dropped > 0 ) {
		if ( showdrop->integer || showpackets->integer ) {
			Com_Printf( "%s:Dropped %i packets at %i\n"
			, NET_AdrToString( chan->remoteAddress )
			, chan->dropped
			, sequence );
		}
	}


	//
	// if this is the final framgent of a reliable message,
	// bump incoming_reliable_sequence
	//
	if ( fragmented ) {
		// make sure we
		if ( sequence != chan->fragmentSequence ) {
			chan->fragmentSequence = sequence;
			chan->fragmentLength = 0;
		}

		// if we missed a fragment, dump the message
		if ( fragmentStart != chan->fragmentLength ) {
			if ( showdrop->integer || showpackets->integer ) {
//.........这里部分代码省略.........

/*
==================
CL_ParseClientdata

Server information pertaining to this client only
==================
*/
void CL_ParseClientdata (void)
{
	int		i, j;
	int		bits; //johnfitz

	bits = (unsigned short)MSG_ReadShort (); //johnfitz -- read bits here isntead of in CL_ParseServerMessage()

	//johnfitz -- PROTOCOL_FITZQUAKE
	if (bits & SU_EXTEND1)
		bits |= (MSG_ReadByte() << 16);
	if (bits & SU_EXTEND2)
		bits |= (MSG_ReadByte() << 24);
	//johnfitz

	if (bits & SU_VIEWHEIGHT)
		cl.viewheight = MSG_ReadChar ();
	else
		cl.viewheight = DEFAULT_VIEWHEIGHT;

	if (bits & SU_IDEALPITCH)
		cl.idealpitch = MSG_ReadChar ();
	else
		cl.idealpitch = 0;

	VectorCopy (cl.mvelocity[0], cl.mvelocity[1]);
	for (i = 0; i < 3; i++)
	{
		if (bits & (SU_PUNCH1<<i) )
			cl.punchangle[i] = MSG_ReadChar();
		else
			cl.punchangle[i] = 0;

		if (bits & (SU_VELOCITY1<<i) )
			cl.mvelocity[0][i] = MSG_ReadChar()*16;
		else
			cl.mvelocity[0][i] = 0;
	}

	//johnfitz -- update v_punchangles
	if (v_punchangles[0][0] != cl.punchangle[0] || v_punchangles[0][1] != cl.punchangle[1] || v_punchangles[0][2] != cl.punchangle[2])
	{
		VectorCopy (v_punchangles[0], v_punchangles[1]);
		VectorCopy (cl.punchangle, v_punchangles[0]);
	}
	//johnfitz

// [always sent]	if (bits & SU_ITEMS)
		i = MSG_ReadLong ();

	if (cl.items != i)
	{	// set flash times
		Sbar_Changed ();
		for (j = 0; j < 32; j++)
			if ( (i & (1<<j)) && !(cl.items & (1<<j)))
				cl.item_gettime[j] = cl.time;
		cl.items = i;
	}

	cl.onground = (bits & SU_ONGROUND) != 0;
	cl.inwater = (bits & SU_INWATER) != 0;

	if (bits & SU_WEAPONFRAME)
		cl.stats[STAT_WEAPONFRAME] = MSG_ReadByte ();
	else
		cl.stats[STAT_WEAPONFRAME] = 0;

	if (bits & SU_ARMOR)
		i = MSG_ReadByte ();
	else
		i = 0;
	if (cl.stats[STAT_ARMOR] != i)
	{
		cl.stats[STAT_ARMOR] = i;
		Sbar_Changed ();
	}

	if (bits & SU_WEAPON)
		i = MSG_ReadByte ();
	else
		i = 0;
	if (cl.stats[STAT_WEAPON] != i)
	{
		cl.stats[STAT_WEAPON] = i;
		Sbar_Changed ();

		//johnfitz -- lerping
		if (cl.viewent.model != cl.model_precache[cl.stats[STAT_WEAPON]])
			cl.viewent.lerpflags |= LERP_RESETANIM; //don't lerp animation across model changes
		//johnfitz
	}

	i = MSG_ReadShort ();
	if (cl.stats[STAT_HEALTH] != i)
//.........这里部分代码省略.........

/*
==================
CL_ParseGamestate
==================
*/
void CL_ParseGamestate( msg_t *msg ) {
	int i;
	entityState_t   *es;
	int newnum;
	entityState_t nullstate;
	int cmd;
	char            *s;
	char oldGame[MAX_QPATH];

	Con_Close();

	clc.connectPacketCount = 0;

	// wipe local client state
	CL_ClearState();

	// a gamestate always marks a server command sequence
	clc.serverCommandSequence = MSG_ReadLong( msg );

	// parse all the configstrings and baselines
	cl.gameState.dataCount = 1; // leave a 0 at the beginning for uninitialized configstrings
	while ( 1 ) {
		cmd = MSG_ReadByte( msg );

		if ( cmd == svc_EOF ) {
			break;
		}

		if ( cmd == svc_configstring ) {
			int len;

			i = MSG_ReadShort( msg );
			if ( i < 0 || i >= MAX_CONFIGSTRINGS ) {
				Com_Error( ERR_DROP, "configstring > MAX_CONFIGSTRINGS" );
			}
			s = MSG_ReadBigString( msg );
			len = strlen( s );

			if ( len + 1 + cl.gameState.dataCount > MAX_GAMESTATE_CHARS ) {
				Com_Error( ERR_DROP, "MAX_GAMESTATE_CHARS exceeded" );
			}

			// append it to the gameState string buffer
			cl.gameState.stringOffsets[ i ] = cl.gameState.dataCount;
			memcpy( cl.gameState.stringData + cl.gameState.dataCount, s, len + 1 );
			cl.gameState.dataCount += len + 1;
		} else if ( cmd == svc_baseline ) {
			newnum = MSG_ReadBits( msg, GENTITYNUM_BITS );
			if ( newnum < 0 || newnum >= MAX_GENTITIES ) {
				Com_Error( ERR_DROP, "Baseline number out of range: %i", newnum );
			}
			memset( &nullstate, 0, sizeof( nullstate ) );
			es = &cl.entityBaselines[ newnum ];
			MSG_ReadDeltaEntity( msg, &nullstate, es, newnum );
		} else {
			Com_Error( ERR_DROP, "CL_ParseGamestate: bad command byte" );
		}
	}

	clc.clientNum = MSG_ReadLong( msg );
	// read the checksum feed
	clc.checksumFeed = MSG_ReadLong( msg );

	// save old gamedir
	Cvar_VariableStringBuffer("fs_game", oldGame, sizeof(oldGame));

	// parse useful values out of CS_SERVERINFO
	CL_ParseServerInfo();

	// parse serverId and other cvars
	CL_SystemInfoChanged();

	// stop recording now so the demo won't have an unnecessary level load at the end.
	if(cl_autoRecordDemo->integer && clc.demorecording)
		CL_StopRecord_f();

	// reinitialize the filesystem if the game directory has changed
	if(!cl_oldGameSet && (Cvar_Flags("fs_game") & CVAR_MODIFIED))
	{
		cl_oldGameSet = qtrue;
		Q_strncpyz(cl_oldGame, oldGame, sizeof(cl_oldGame));
	}

	FS_ConditionalRestart(clc.checksumFeed, qfalse);

	// This used to call CL_StartHunkUsers, but now we enter the download state before loading the
	// cgame
	CL_InitDownloads();

	// make sure the game starts
	Cvar_Set( "cl_paused", "0" );
}

/*
=====================
CL_ParseVoip

A VoIP message has been received from the server
=====================
*/
static
void CL_ParseVoip ( msg_t *msg, qboolean ignoreData ) {
	static short decoded[VOIP_MAX_PACKET_SAMPLES*4]; // !!! FIXME: don't hard code

	const int sender = MSG_ReadShort(msg);
	const int generation = MSG_ReadByte(msg);
	const int sequence = MSG_ReadLong(msg);
	const int frames = MSG_ReadByte(msg);
	const int packetsize = MSG_ReadShort(msg);
	const int flags = MSG_ReadBits(msg, VOIP_FLAGCNT);
	unsigned char encoded[4000];
	int	numSamples;
	int seqdiff;
	int written = 0;
	int i;

	Com_DPrintf("VoIP: %d-byte packet from client %d\n", packetsize, sender);

	if (sender < 0)
		return;   // short/invalid packet, bail.
	else if (generation < 0)
		return;   // short/invalid packet, bail.
	else if (sequence < 0)
		return;   // short/invalid packet, bail.
	else if (frames < 0)
		return;   // short/invalid packet, bail.
	else if (packetsize < 0)
		return;   // short/invalid packet, bail.

	if (packetsize > sizeof (encoded)) {  // overlarge packet?
		int bytesleft = packetsize;
		while (bytesleft) {
			int br = bytesleft;
			if (br > sizeof (encoded))
				br = sizeof (encoded);
			MSG_ReadData(msg, encoded, br);
			bytesleft -= br;
		}
		return;   // overlarge packet, bail.
	}

	MSG_ReadData(msg, encoded, packetsize);

	if (ignoreData) {
		return; // just ignore legacy speex voip data
	} else if (!clc.voipCodecInitialized) {
		return;   // can't handle VoIP without libopus!
	} else if (sender >= MAX_CLIENTS) {
		return;   // bogus sender.
	} else if (CL_ShouldIgnoreVoipSender(sender)) {
		return;   // Channel is muted, bail.
	}

	// !!! FIXME: make sure data is narrowband? Does decoder handle this?

	Com_DPrintf("VoIP: packet accepted!\n");

	seqdiff = sequence - clc.voipIncomingSequence[sender];

	// This is a new "generation" ... a new recording started, reset the bits.
	if (generation != clc.voipIncomingGeneration[sender]) {
		Com_DPrintf("VoIP: new generation %d!\n", generation);
		opus_decoder_ctl(clc.opusDecoder[sender], OPUS_RESET_STATE);
		clc.voipIncomingGeneration[sender] = generation;
		seqdiff = 0;
	} else if (seqdiff < 0) {   // we're ahead of the sequence?!
		// This shouldn't happen unless the packet is corrupted or something.
		Com_DPrintf("VoIP: misordered sequence! %d < %d!\n",
		            sequence, clc.voipIncomingSequence[sender]);
		// reset the decoder just in case.
		opus_decoder_ctl(clc.opusDecoder[sender], OPUS_RESET_STATE);
		seqdiff = 0;
	} else if (seqdiff * VOIP_MAX_PACKET_SAMPLES*2 >= sizeof (decoded)) { // dropped more than we can handle?
		// just start over.
		Com_DPrintf("VoIP: Dropped way too many (%d) frames from client #%d\n",
		            seqdiff, sender);
		opus_decoder_ctl(clc.opusDecoder[sender], OPUS_RESET_STATE);
		seqdiff = 0;
	}

	if (seqdiff != 0) {
		Com_DPrintf("VoIP: Dropped %d frames from client #%d\n",
		            seqdiff, sender);
		// tell opus that we're missing frames...
		for (i = 0; i < seqdiff; i++) {
			assert((written + VOIP_MAX_PACKET_SAMPLES) * 2 < sizeof (decoded));
			numSamples = opus_decode(clc.opusDecoder[sender], NULL, 0, decoded + written, VOIP_MAX_PACKET_SAMPLES, 0);
			if ( numSamples <= 0 ) {
				Com_DPrintf("VoIP: Error decoding frame %d from client #%d\n", i, sender);
				continue;
			}
			written += numSamples;
		}
//.........这里部分代码省略.........

/*
=================
Netchan_Process

Returns qfalse if the message should not be processed due to being
out of order or a fragment.

Msg must be large enough to hold MAX_MSGLEN, because if this is the
final fragment of a multi-part message, the entire thing will be
copied out.
=================
*/
qboolean Netchan_Process( netchan_t *chan, msg_t *msg ) {
	int			sequence;
	int			qport;
	int			fragmentStart, fragmentLength;
	qboolean	fragmented;

	// XOR unscramble all data in the packet after the header
//	Netchan_UnScramblePacket( msg );

	// get sequence numbers		
	MSG_BeginReadingOOB( msg );
	sequence = MSG_ReadLong( msg );

	// check for fragment information
	if ( sequence & FRAGMENT_BIT ) {
		sequence &= ~FRAGMENT_BIT;
		fragmented = qtrue;
	} else {
		fragmented = qfalse;
	}

	// read the qport if we are a server
	if ( chan->sock == NS_SERVER ) {
		qport = MSG_ReadShort( msg );
	}

	// read the fragment information
	if ( fragmented ) {
		fragmentStart = MSG_ReadShort( msg );
		fragmentLength = MSG_ReadShort( msg );
	} else {
		fragmentStart = 0;		// stop warning message
		fragmentLength = 0;
	}

	if ( showpackets->integer ) {
		if ( fragmented ) {
			Com_Printf( "%s recv %4i : s=%i fragment=%i,%i\n"
				, netsrcString[ chan->sock ]
				, msg->cursize
				, sequence
				, fragmentStart, fragmentLength );
		} else {
			Com_Printf( "%s recv %4i : s=%i\n"
				, netsrcString[ chan->sock ]
				, msg->cursize
				, sequence );
		}
	}

	//
	// discard out of order or duplicated packets
	//
	if ( sequence <= chan->incomingSequence ) {
		if ( showdrop->integer || showpackets->integer ) {
			Com_Printf( "%s:Out of order packet %i at %i\n"
				, NET_AdrToString( chan->remoteAddress )
				,  sequence
				, chan->incomingSequence );
		}
		return qfalse;
	}

	//
	// dropped packets don't keep the message from being used
	//
	chan->dropped = sequence - (chan->incomingSequence+1);
	if ( chan->dropped > 0 ) {
		if ( showdrop->integer || showpackets->integer ) {
			Com_Printf( "%s:Dropped %i packets at %i\n"
			, NET_AdrToString( chan->remoteAddress )
			, chan->dropped
			, sequence );
		}
	}
	

	//
	// if this is the final framgent of a reliable message,
	// bump incoming_reliable_sequence 
	//
	if ( fragmented ) {
		// TTimo
		// make sure we add the fragments in correct order
		// either a packet was dropped, or we received this one too soon
		// we don't reconstruct the fragments. we will wait till this fragment gets to us again
		// (NOTE: we could probably try to rebuild by out of order chunks if needed)
		if ( sequence != chan->fragmentSequence ) {
//.........这里部分代码省略.........

/*
=====================
CL_ParseVoip

A VoIP message has been received from the server
=====================
*/
static
void CL_ParseVoip ( msg_t *msg ) {
	static short decoded[4096];  // !!! FIXME: don't hardcode.

	const int sender = MSG_ReadShort(msg);
	const int generation = MSG_ReadByte(msg);
	const int sequence = MSG_ReadLong(msg);
	const int frames = MSG_ReadByte(msg);
	const int packetsize = MSG_ReadShort(msg);
	const int flags = MSG_ReadBits(msg, VOIP_FLAGCNT);
	char encoded[1024];
	int seqdiff = sequence - clc.voipIncomingSequence[sender];
	int written = 0;
	int i;

	Com_DPrintf("VoIP: %d-byte packet from client %d\n", packetsize, sender);

	if (sender < 0)
		return;   // short/invalid packet, bail.
	else if (generation < 0)
		return;   // short/invalid packet, bail.
	else if (sequence < 0)
		return;   // short/invalid packet, bail.
	else if (frames < 0)
		return;   // short/invalid packet, bail.
	else if (packetsize < 0)
		return;   // short/invalid packet, bail.

	if (packetsize > sizeof (encoded)) {  // overlarge packet?
		int bytesleft = packetsize;
		while (bytesleft) {
			int br = bytesleft;
			if (br > sizeof (encoded))
				br = sizeof (encoded);
			MSG_ReadData(msg, encoded, br);
			bytesleft -= br;
		}
		return;   // overlarge packet, bail.
	}

	if (!clc.speexInitialized) {
		MSG_ReadData(msg, encoded, packetsize);  // skip payload.
		return;   // can't handle VoIP without libspeex!
	} else if (sender >= MAX_CLIENTS) {
		MSG_ReadData(msg, encoded, packetsize);  // skip payload.
		return;   // bogus sender.
	} else if (CL_ShouldIgnoreVoipSender(sender)) {
		MSG_ReadData(msg, encoded, packetsize);  // skip payload.
		return;   // Channel is muted, bail.
	}

	// !!! FIXME: make sure data is narrowband? Does decoder handle this?

	Com_DPrintf("VoIP: packet accepted!\n");

	// This is a new "generation" ... a new recording started, reset the bits.
	if (generation != clc.voipIncomingGeneration[sender]) {
		Com_DPrintf("VoIP: new generation %d!\n", generation);
		speex_bits_reset(&clc.speexDecoderBits[sender]);
		clc.voipIncomingGeneration[sender] = generation;
		seqdiff = 0;
	} else if (seqdiff < 0) {   // we're ahead of the sequence?!
		// This shouldn't happen unless the packet is corrupted or something.
		Com_DPrintf("VoIP: misordered sequence! %d < %d!\n",
		            sequence, clc.voipIncomingSequence[sender]);
		// reset the bits just in case.
		speex_bits_reset(&clc.speexDecoderBits[sender]);
		seqdiff = 0;
	} else if (seqdiff > 100) { // more than 2 seconds of audio dropped?
		// just start over.
		Com_DPrintf("VoIP: Dropped way too many (%d) frames from client #%d\n",
		            seqdiff, sender);
		speex_bits_reset(&clc.speexDecoderBits[sender]);
		seqdiff = 0;
	}

	if (seqdiff != 0) {
		Com_DPrintf("VoIP: Dropped %d frames from client #%d\n",
		            seqdiff, sender);
		// tell speex that we're missing frames...
		for (i = 0; i < seqdiff; i++) {
			assert((written + clc.speexFrameSize) * 2 < sizeof (decoded));
			speex_decode_int(clc.speexDecoder[sender], NULL, decoded + written);
			written += clc.speexFrameSize;
		}
	}

	for (i = 0; i < frames; i++) {
		char encoded[256];
		const int len = MSG_ReadByte(msg);
		if (len < 0) {
			Com_DPrintf("VoIP: Short packet!\n");
			break;
//.........这里部分代码省略.........

/*
==================
CL_ParseGamestate
==================
*/
void CL_ParseGamestate( msg_t *msg )
{
	int           i;
	entityState_t *es;
	int           newnum;
	entityState_t nullstate;
	int           cmd;

	Con_Close();

	clc.connectPacketCount = 0;

	// wipe local client state
	CL_ClearState();

	// a gamestate always marks a server command sequence
	clc.serverCommandSequence = MSG_ReadLong( msg );

	// parse all the configstrings and baselines
	while ( 1 )
	{
		cmd = MSG_ReadByte( msg );

		if ( cmd == svc_EOF )
		{
			break;
		}

		if ( cmd == svc_configstring )
		{
			i = MSG_ReadShort( msg );

			if ( i < 0 || i >= MAX_CONFIGSTRINGS )
			{
				Com_Error( ERR_DROP, "configstring > MAX_CONFIGSTRINGS" );
			}

            const char* str = MSG_ReadBigString( msg );
            std::string s = str;
			cl.gameState[i] = str;
		}
		else if ( cmd == svc_baseline )
		{
			newnum = MSG_ReadBits( msg, GENTITYNUM_BITS );

			if ( newnum < 0 || newnum >= MAX_GENTITIES )
			{
				Com_Error( ERR_DROP, "Baseline number out of range: %i", newnum );
			}

			memset( &nullstate, 0, sizeof( nullstate ) );
			es = &cl.entityBaselines[ newnum ];
			MSG_ReadDeltaEntity( msg, &nullstate, es, newnum );
		}
		else
		{
			Com_Error( ERR_DROP, "CL_ParseGamestate: bad command byte" );
		}
	}

	clc.clientNum = MSG_ReadLong( msg );
	// read the checksum feed
	clc.checksumFeed = MSG_ReadLong( msg );

	// parse serverId and other cvars
	CL_SystemInfoChanged();

	// This used to call CL_StartHunkUsers, but now we enter the download state before loading the
	// cgame
	CL_InitDownloads();

	// make sure the game starts
	Cvar_Set( "cl_paused", "0" );
}

/*
=====================
CL_ParseDownload

A download message has been received from the server
=====================
*/
void CL_ParseDownload( msg_t *msg )
{
	int           size;
	unsigned char data[ MAX_MSGLEN ];
	int           block;

	if ( !*cls.downloadTempName )
	{
		Com_Printf( "Server sending download, but no download was requested\n" );
        // Eat the packet anyway
	    block = MSG_ReadShort( msg );
        if (block == -1) {
			MSG_ReadString( msg );
			MSG_ReadLong( msg );
			MSG_ReadLong( msg );
        } else if (block != 0) {
            size = MSG_ReadShort( msg );
            if ( size < 0 || size > (int) sizeof( data ) )
            {
                Com_Error( ERR_DROP, "CL_ParseDownload: Invalid size %d for download chunk.", size );
            }
	        MSG_ReadData( msg, data, size );
        }

		CL_AddReliableCommand( "stopdl" );
		return;
	}

	// read the data
	block = MSG_ReadShort( msg );

	// TTimo - www dl
	// if we haven't acked the download redirect yet
	if ( block == -1 )
	{
		if ( !clc.bWWWDl )
		{
			// server is sending us a www download
			Q_strncpyz( cls.originalDownloadName, cls.downloadName, sizeof( cls.originalDownloadName ) );
			Q_strncpyz( cls.downloadName, MSG_ReadString( msg ), sizeof( cls.downloadName ) );
			clc.downloadSize = MSG_ReadLong( msg );
			clc.downloadFlags = MSG_ReadLong( msg );

            downloadLogger.Debug("Server sent us a new WWW DL '%s', size %i, flags %i",
                                 cls.downloadName, clc.downloadSize, clc.downloadFlags);

			Cvar_SetValue( "cl_downloadSize", clc.downloadSize );
			clc.bWWWDl = true; // activate wwwdl client loop
			CL_AddReliableCommand( "wwwdl ack" );
			cls.state = CA_DOWNLOADING;

			// make sure the server is not trying to redirect us again on a bad checksum
			if ( strstr( clc.badChecksumList, va( "@%s", cls.originalDownloadName ) ) )
			{
				Com_Printf( "refusing redirect to %s by server (bad checksum)\n", cls.downloadName );
				CL_AddReliableCommand( "wwwdl fail" );
				clc.bWWWDlAborting = true;
				return;
			}

			if ( !DL_BeginDownload( cls.downloadTempName, cls.downloadName ) )
			{
				// setting bWWWDl to false after sending the wwwdl fail doesn't work
				// not sure why, but I suspect we have to eat all remaining block -1 that the server has sent us
				// still leave a flag so that CL_WWWDownload is inactive
				// we count on server sending us a gamestate to start up clean again
				CL_AddReliableCommand( "wwwdl fail" );
				clc.bWWWDlAborting = true;
				Com_Printf( "Failed to initialize download for '%s'\n", cls.downloadName );
			}

			// Check for a disconnected download
			// we'll let the server disconnect us when it gets the bbl8r message
			if ( clc.downloadFlags & ( 1 << DL_FLAG_DISCON ) )
			{
				CL_AddReliableCommand( "wwwdl bbl8r" );
				cls.bWWWDlDisconnected = true;
			}

			return;
		}
		else
		{
			// server keeps sending that message till we ack it, eat and ignore
			//MSG_ReadLong( msg );
			MSG_ReadString( msg );
			MSG_ReadLong( msg );
			MSG_ReadLong( msg );
			return;
		}
	}

	if ( !block )
//.........这里部分代码省略.........

static qsocket_t *_Datagram_CheckNewConnections (void)
{
	struct qsockaddr clientaddr;
	struct qsockaddr newaddr;
	int			newsock;
	int			acceptsock;
	qsocket_t	*sock;
	qsocket_t	*s;
	int			len;
	int			command;
	int			control;
	int			ret;

	acceptsock = dfunc.CheckNewConnections();
	if (acceptsock == -1)
		return NULL;

	SZ_Clear(&net_message);

	len = dfunc.Read (acceptsock, net_message.data, net_message.maxsize, &clientaddr);
	if (len < sizeof(int))
		return NULL;
	net_message.cursize = len;

	MSG_BeginReading ();
	control = BigLong(*((int *)net_message.data));
	MSG_ReadLong();
	if (control == -1)
		return NULL;
	if ((control & (~NETFLAG_LENGTH_MASK)) !=  NETFLAG_CTL)
		return NULL;
	if ((control & NETFLAG_LENGTH_MASK) != len)
		return NULL;

	command = MSG_ReadByte();
	if (command == CCREQ_SERVER_INFO)
	{
		if (Q_strcmp(MSG_ReadString(), "QUAKE") != 0)
			return NULL;

		SZ_Clear(&net_message);
		// save space for the header, filled in later
		MSG_WriteLong(&net_message, 0);
		MSG_WriteByte(&net_message, CCREP_SERVER_INFO);
		dfunc.GetSocketAddr(acceptsock, &newaddr);
		MSG_WriteString(&net_message, dfunc.AddrToString(&newaddr));
		MSG_WriteString(&net_message, hostname.string);
		MSG_WriteString(&net_message, sv.name);
		MSG_WriteByte(&net_message, net_activeconnections);
		MSG_WriteByte(&net_message, svs.maxclients);
		MSG_WriteByte(&net_message, NET_PROTOCOL_VERSION);
		*((int *)net_message.data) = BigLong(NETFLAG_CTL | (net_message.cursize & NETFLAG_LENGTH_MASK));
		dfunc.Write (acceptsock, net_message.data, net_message.cursize, &clientaddr);
		SZ_Clear(&net_message);
		return NULL;
	}

	if (command == CCREQ_PLAYER_INFO)
	{
		int			playerNumber;
		int			activeNumber;
		int			clientNumber;
		client_t	*client;
		
		playerNumber = MSG_ReadByte();
		activeNumber = -1;
		for (clientNumber = 0, client = svs.clients; clientNumber < svs.maxclients; clientNumber++, client++)
		{
			if (client->active)
			{
				activeNumber++;
				if (activeNumber == playerNumber)
					break;
			}
		}
		if (clientNumber == svs.maxclients)
			return NULL;

		SZ_Clear(&net_message);
		// save space for the header, filled in later
		MSG_WriteLong(&net_message, 0);
		MSG_WriteByte(&net_message, CCREP_PLAYER_INFO);
		MSG_WriteByte(&net_message, playerNumber);
		MSG_WriteString(&net_message, client->name);
		MSG_WriteLong(&net_message, client->colors);
		MSG_WriteLong(&net_message, (int)client->edict->v.frags);
		MSG_WriteLong(&net_message, (int)(net_time - client->netconnection->connecttime));
		MSG_WriteString(&net_message, client->netconnection->address);
		*((int *)net_message.data) = BigLong(NETFLAG_CTL | (net_message.cursize & NETFLAG_LENGTH_MASK));
		dfunc.Write (acceptsock, net_message.data, net_message.cursize, &clientaddr);
		SZ_Clear(&net_message);

		return NULL;
	}

	if (command == CCREQ_RULE_INFO)
	{
		char	*prevCvarName;
		cvar_t	*var;

//.........这里部分代码省略.........

static qsocket_t *_Datagram_Connect (char *host)
{
	struct qsockaddr sendaddr;
	struct qsockaddr readaddr;
	qsocket_t	*sock;
	int			newsock;
	int			ret;
	int			reps;
	double		start_time;
	int			control;
	char		*reason;

	// see if we can resolve the host name
	if (dfunc.GetAddrFromName(host, &sendaddr) == -1)
		return NULL;

	newsock = dfunc.OpenSocket (0);
	if (newsock == -1)
		return NULL;

	sock = NET_NewQSocket ();
	if (sock == NULL)
		goto ErrorReturn2;
	sock->socket = newsock;
	sock->landriver = net_landriverlevel;

	// connect to the host
	if (dfunc.Connect (newsock, &sendaddr) == -1)
		goto ErrorReturn;

	// send the connection request
	Con_Printf("trying...\n"); SCR_UpdateScreen ();
	start_time = net_time;

	for (reps = 0; reps < 3; reps++)
	{
		SZ_Clear(&net_message);
		// save space for the header, filled in later
		MSG_WriteLong(&net_message, 0);
		MSG_WriteByte(&net_message, CCREQ_CONNECT);
		MSG_WriteString(&net_message, "QUAKE");
		MSG_WriteByte(&net_message, NET_PROTOCOL_VERSION);
		*((int *)net_message.data) = BigLong(NETFLAG_CTL | (net_message.cursize & NETFLAG_LENGTH_MASK));
		dfunc.Write (newsock, net_message.data, net_message.cursize, &sendaddr);
		SZ_Clear(&net_message);
		do
		{
			ret = dfunc.Read (newsock, net_message.data, net_message.maxsize, &readaddr);
			// if we got something, validate it
			if (ret > 0)
			{
				// is it from the right place?
				if (sfunc.AddrCompare(&readaddr, &sendaddr) != 0)
				{
#ifdef DEBUG
					Con_Printf("wrong reply address\n");
					Con_Printf("Expected: %s\n", StrAddr (&sendaddr));
					Con_Printf("Received: %s\n", StrAddr (&readaddr));
					SCR_UpdateScreen ();
#endif
					ret = 0;
					continue;
				}

				if (ret < sizeof(int))
				{
					ret = 0;
					continue;
				}

				net_message.cursize = ret;
				MSG_BeginReading ();

				control = BigLong(*((int *)net_message.data));
				MSG_ReadLong();
				if (control == -1)
				{
					ret = 0;
					continue;
				}
				if ((control & (~NETFLAG_LENGTH_MASK)) !=  NETFLAG_CTL)
				{
					ret = 0;
					continue;
				}
				if ((control & NETFLAG_LENGTH_MASK) != ret)
				{
					ret = 0;
					continue;
				}
			}
		}
		while (ret == 0 && (SetNetTime() - start_time) < 2.5);
		if (ret)
			break;
		Con_Printf("still trying...\n"); SCR_UpdateScreen ();
		start_time = SetNetTime();
	}

	if (ret == 0)
//.........这里部分代码省略.........

static void _Datagram_SearchForHosts (qboolean xmit)
{
	int		ret;
	int		n;
	int		i;
	struct qsockaddr readaddr;
	struct qsockaddr myaddr;
	int		control;

	dfunc.GetSocketAddr (dfunc.controlSock, &myaddr);
	if (xmit)
	{
		SZ_Clear(&net_message);
		// save space for the header, filled in later
		MSG_WriteLong(&net_message, 0);
		MSG_WriteByte(&net_message, CCREQ_SERVER_INFO);
		MSG_WriteString(&net_message, "QUAKE");
		MSG_WriteByte(&net_message, NET_PROTOCOL_VERSION);
		*((int *)net_message.data) = BigLong(NETFLAG_CTL | (net_message.cursize & NETFLAG_LENGTH_MASK));
		dfunc.Broadcast(dfunc.controlSock, net_message.data, net_message.cursize);
		SZ_Clear(&net_message);
	}

	while ((ret = dfunc.Read (dfunc.controlSock, net_message.data, net_message.maxsize, &readaddr)) > 0)
	{
		if (ret < sizeof(int))
			continue;
		net_message.cursize = ret;

		// don't answer our own query
		if (dfunc.AddrCompare(&readaddr, &myaddr) >= 0)
			continue;

		// is the cache full?
		if (hostCacheCount == HOSTCACHESIZE)
			continue;

		MSG_BeginReading ();
		control = BigLong(*((int *)net_message.data));
		MSG_ReadLong();
		if (control == -1)
			continue;
		if ((control & (~NETFLAG_LENGTH_MASK)) !=  NETFLAG_CTL)
			continue;
		if ((control & NETFLAG_LENGTH_MASK) != ret)
			continue;

		if (MSG_ReadByte() != CCREP_SERVER_INFO)
			continue;

		dfunc.GetAddrFromName(MSG_ReadString(), &readaddr);
		// search the cache for this server
		for (n = 0; n < hostCacheCount; n++)
			if (dfunc.AddrCompare(&readaddr, &hostcache[n].addr) == 0)
				break;

		// is it already there?
		if (n < hostCacheCount)
			continue;

		// add it
		hostCacheCount++;
		Q_strcpy(hostcache[n].name, MSG_ReadString());
		Q_strcpy(hostcache[n].map, MSG_ReadString());
		hostcache[n].users = MSG_ReadByte();
		hostcache[n].maxusers = MSG_ReadByte();
		if (MSG_ReadByte() != NET_PROTOCOL_VERSION)
		{
			Q_strcpy(hostcache[n].cname, hostcache[n].name);
			hostcache[n].cname[14] = 0;
			Q_strcpy(hostcache[n].name, "*");
			Q_strcat(hostcache[n].name, hostcache[n].cname);
		}
		Q_memcpy(&hostcache[n].addr, &readaddr, sizeof(struct qsockaddr));
		hostcache[n].driver = net_driverlevel;
		hostcache[n].ldriver = net_landriverlevel;
		Q_strcpy(hostcache[n].cname, dfunc.AddrToString(&readaddr));

		// check for a name conflict
		for (i = 0; i < hostCacheCount; i++)
		{
			if (i == n)
				continue;
			if (Q_strcasecmp (hostcache[n].name, hostcache[i].name) == 0)
			{
				i = Q_strlen(hostcache[n].name);
				if (i < 15 && hostcache[n].name[i-1] > '8')
				{
					hostcache[n].name[i] = '0';
					hostcache[n].name[i+1] = 0;
				}
				else
					hostcache[n].name[i-1]++;
				i = -1;
			}
		}
	}
}

/*
===================
SV_ExecuteClientMessage

Parse a client packet
===================
*/
void SV_ExecuteClientMessage( client_t *cl, msg_t *msg ) {
	int			c;
	int			serverId;

	MSG_Bitstream(msg);

	serverId = MSG_ReadLong( msg );
	cl->messageAcknowledge = MSG_ReadLong( msg );

	if (cl->messageAcknowledge < 0) {
		// usually only hackers create messages like this
		// it is more annoying for them to let them hanging
#ifndef NDEBUG
		SV_DropClient( cl, "DEBUG: illegible client message" );
#endif
		return;
	}

	cl->reliableAcknowledge = MSG_ReadLong( msg );

	// NOTE: when the client message is fux0red the acknowledgement numbers
	// can be out of range, this could cause the server to send thousands of server
	// commands which the server thinks are not yet acknowledged in SV_UpdateServerCommandsToClient
	if (cl->reliableAcknowledge < cl->reliableSequence - MAX_RELIABLE_COMMANDS) {
		// usually only hackers create messages like this
		// it is more annoying for them to let them hanging
#ifndef NDEBUG
		SV_DropClient( cl, "DEBUG: illegible client message" );
#endif
		cl->reliableAcknowledge = cl->reliableSequence;
		return;
	}
	// if this is a usercmd from a previous gamestate,
	// ignore it or retransmit the current gamestate
	// 
	// if the client was downloading, let it stay at whatever serverId and
	// gamestate it was at.  This allows it to keep downloading even when
	// the gamestate changes.  After the download is finished, we'll
	// notice and send it a new game state
	//
	// https://zerowing.idsoftware.com/bugzilla/show_bug.cgi?id=536
	// don't drop as long as previous command was a nextdl, after a dl is done, downloadName is set back to ""
	// but we still need to read the next message to move to next download or send gamestate
	// I don't like this hack though, it must have been working fine at some point, suspecting the fix is somewhere else
	if ( serverId != sv.serverId && !*cl->downloadName && !strstr(cl->lastClientCommandString, "nextdl") ) {
		if ( serverId >= sv.restartedServerId && serverId < sv.serverId ) { // TTimo - use a comparison here to catch multiple map_restart
			// they just haven't caught the map_restart yet
			Com_DPrintf("%s : ignoring pre map_restart / outdated client message\n", cl->name);
			return;
		}
		// if we can tell that the client has dropped the last
		// gamestate we sent them, resend it
		if ( cl->messageAcknowledge > cl->gamestateMessageNum ) {
			Com_DPrintf( "%s : dropped gamestate, resending\n", cl->name );
			SV_SendClientGameState( cl );
		}
		return;
	}

	// read optional clientCommand strings
	do {
		c = MSG_ReadByte( msg );
		if ( c == clc_EOF ) {
			break;
		}
		if ( c != clc_clientCommand ) {
			break;
		}
		if ( !SV_ClientCommand( cl, msg ) ) {
			return;	// we couldn't execute it because of the flood protection
		}
		if (cl->state == CS_ZOMBIE) {
			return;	// disconnect command
		}
	} while ( 1 );

	// read the usercmd_t
	if ( c == clc_move ) {
		SV_UserMove( cl, msg, qtrue );
	} else if ( c == clc_moveNoDelta ) {
		SV_UserMove( cl, msg, qfalse );
	} else if ( c != clc_EOF ) {
		Com_Printf( "WARNING: bad command byte for client %i\n", cl - svs.clients );
	}
//	if ( msg->readcount != msg->cursize ) {
//		Com_Printf( "WARNING: Junk at end of packet for client %i\n", cl - svs.clients );
//	}
}