Initial commit.
This commit is contained in:
Jim Gray
566
code/qcommon/net_chan.cpp
Normal file
566
code/qcommon/net_chan.cpp
Normal file
@@ -0,0 +1,566 @@
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#include "../game/q_shared.h"
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#include "qcommon.h"
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/*
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packet header
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-------------
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4 outgoing sequence. high bit will be set if this is a fragmented message
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4 acknowledge sequence
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[2 qport (only for client to server)]
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[2 fragment start byte]
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[2 fragment length. if < FRAGMENT_SIZE, this is the last fragment]
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if the sequence number is -1, the packet should be handled as an out-of-band
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message instead of as part of a netcon.
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All fragments will have the same sequence numbers.
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The qport field is a workaround for bad address translating routers that
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sometimes remap the client's source port on a packet during gameplay.
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If the base part of the net address matches and the qport matches, then the
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channel matches even if the IP port differs. The IP port should be updated
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to the new value before sending out any replies.
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*/
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#define MAX_PACKETLEN (MAX_MSGLEN) //(1400) // max size of a network packet
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#define MAX_LOOPDATA 16 * 1024
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#if (MAX_PACKETLEN > MAX_MSGLEN)
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#error MAX_PACKETLEN must be <= MAX_MSGLEN
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#endif
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#if (MAX_LOOPDATA > MAX_MSGLEN)
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#error MAX_LOOPDATA must be <= MAX_MSGLEN
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#endif
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#define FRAGMENT_SIZE (MAX_PACKETLEN - 100)
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#define PACKET_HEADER 10 // two ints and a short
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#define FRAGMENT_BIT (1<<31)
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cvar_t *showpackets;
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cvar_t *showdrop;
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cvar_t *qport;
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static char *netsrcString[2] = {
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"client",
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"server"
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};
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typedef struct {
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char loopData[MAX_LOOPDATA];
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int get, send;
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} loopback_t;
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static loopback_t *loopbacks = NULL;
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/*
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===============
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Netchan_Init
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===============
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*/
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void Netchan_Init( int port ) {
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if (!loopbacks)
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{
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loopbacks = (loopback_t*) Z_Malloc(sizeof(loopback_t) * 2, TAG_NEWDEL, qtrue);
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}
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port &= 0xffff;
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showpackets = Cvar_Get ("showpackets", "0", CVAR_TEMP );
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showdrop = Cvar_Get ("showdrop", "0", CVAR_TEMP );
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qport = Cvar_Get ("qport", va("%i", port), CVAR_INIT );
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}
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void Netchan_Shutdown()
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{
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if (loopbacks)
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{
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Z_Free(loopbacks);
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loopbacks = 0;
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}
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}
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/*
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==============
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Netchan_Setup
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called to open a channel to a remote system
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==============
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*/
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void Netchan_Setup( netsrc_t sock, netchan_t *chan, netadr_t adr, int qport ) {
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memset (chan, 0, sizeof(*chan));
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chan->sock = sock;
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chan->remoteAddress = adr;
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chan->qport = qport;
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chan->incomingSequence = 0;
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chan->outgoingSequence = 1;
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}
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/*
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===============
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Netchan_Transmit
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Sends a message to a connection, fragmenting if necessary
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A 0 length will still generate a packet.
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================
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*/
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void Netchan_Transmit( netchan_t *chan, int length, const byte *data ) {
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msg_t send;
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byte send_buf[MAX_PACKETLEN];
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int fragmentStart, fragmentLength;
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fragmentStart = 0; // stop warning message
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fragmentLength = 0;
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// fragment large reliable messages
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if ( length >= FRAGMENT_SIZE ) {
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fragmentStart = 0;
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do {
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// write the packet header
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MSG_Init (&send, send_buf, sizeof(send_buf));
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MSG_WriteLong( &send, chan->outgoingSequence | FRAGMENT_BIT );
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MSG_WriteLong( &send, chan->incomingSequence );
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// send the qport if we are a client
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if ( chan->sock == NS_CLIENT ) {
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MSG_WriteShort( &send, qport->integer );
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}
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// copy the reliable message to the packet first
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fragmentLength = FRAGMENT_SIZE;
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if ( fragmentStart + fragmentLength > length ) {
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fragmentLength = length - fragmentStart;
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}
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MSG_WriteShort( &send, fragmentStart );
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MSG_WriteShort( &send, fragmentLength );
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MSG_WriteData( &send, data + fragmentStart, fragmentLength );
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// send the datagram
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NET_SendPacket( chan->sock, send.cursize, send.data, chan->remoteAddress );
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if ( showpackets->integer ) {
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Com_Printf ("%s send %4i : s=%i ack=%i fragment=%i,%i\n"
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, netsrcString[ chan->sock ]
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, send.cursize
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, chan->outgoingSequence - 1
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, chan->incomingSequence
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, fragmentStart, fragmentLength);
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}
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fragmentStart += fragmentLength;
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// this exit condition is a little tricky, because a packet
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// that is exactly the fragment length still needs to send
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// a second packet of zero length so that the other side
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// can tell there aren't more to follow
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} while ( fragmentStart != length || fragmentLength == FRAGMENT_SIZE );
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chan->outgoingSequence++;
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return;
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}
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// write the packet header
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MSG_Init (&send, send_buf, sizeof(send_buf));
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MSG_WriteLong( &send, chan->outgoingSequence );
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MSG_WriteLong( &send, chan->incomingSequence );
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chan->outgoingSequence++;
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// send the qport if we are a client
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if ( chan->sock == NS_CLIENT ) {
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MSG_WriteShort( &send, qport->integer );
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}
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MSG_WriteData( &send, data, length );
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// send the datagram
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NET_SendPacket( chan->sock, send.cursize, send.data, chan->remoteAddress );
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if ( showpackets->integer ) {
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Com_Printf( "%s send %4i : s=%i ack=%i\n"
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, netsrcString[ chan->sock ]
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, send.cursize
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, chan->outgoingSequence - 1
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, chan->incomingSequence );
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}
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}
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/*
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=================
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Netchan_Process
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Returns qfalse if the message should not be processed due to being
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out of order or a fragment.
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Msg must be large enough to hold MAX_MSGLEN, because if this is the
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final fragment of a multi-part message, the entire thing will be
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copied out.
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=================
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*/
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qboolean Netchan_Process( netchan_t *chan, msg_t *msg ) {
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int sequence, sequence_ack;
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int qport;
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int fragmentStart, fragmentLength;
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qboolean fragmented;
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// get sequence numbers
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MSG_BeginReading( msg );
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sequence = MSG_ReadLong( msg );
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sequence_ack = MSG_ReadLong( msg );
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// check for fragment information
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if ( sequence & FRAGMENT_BIT ) {
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sequence &= ~FRAGMENT_BIT;
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fragmented = qtrue;
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} else {
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fragmented = qfalse;
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}
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// read the qport if we are a server
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if ( chan->sock == NS_SERVER ) {
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qport = MSG_ReadShort( msg );
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}
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// read the fragment information
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if ( fragmented ) {
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fragmentStart = MSG_ReadShort( msg );
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fragmentLength = MSG_ReadShort( msg );
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} else {
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fragmentStart = 0; // stop warning message
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fragmentLength = 0;
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}
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if ( showpackets->integer ) {
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if ( fragmented ) {
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Com_Printf( "%s recv %4i : s=%i ack=%i fragment=%i,%i\n"
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, netsrcString[ chan->sock ]
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, msg->cursize
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, sequence
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, sequence_ack
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, fragmentStart, fragmentLength );
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} else {
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Com_Printf( "%s recv %4i : s=%i ack=%i\n"
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, netsrcString[ chan->sock ]
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, msg->cursize
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, sequence
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, sequence_ack );
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}
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}
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//
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// discard out of order or duplicated packets
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//
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if ( sequence <= chan->incomingSequence ) {
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if ( showdrop->integer || showpackets->integer ) {
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Com_Printf( "%s:Out of order packet %i at %i\n"
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, NET_AdrToString( chan->remoteAddress )
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, sequence
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, chan->incomingSequence );
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}
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return qfalse;
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}
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//
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// dropped packets don't keep the message from being used
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//
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chan->dropped = sequence - (chan->incomingSequence+1);
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if ( chan->dropped > 0 ) {
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if ( showdrop->integer || showpackets->integer ) {
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Com_Printf( "%s:Dropped %i packets at %i\n"
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, NET_AdrToString( chan->remoteAddress )
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, chan->dropped
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, sequence );
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}
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}
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//
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// if this is the final framgent of a reliable message,
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// bump incoming_reliable_sequence
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//
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if ( fragmented ) {
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// make sure we
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if ( sequence != chan->fragmentSequence ) {
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chan->fragmentSequence = sequence;
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chan->fragmentLength = 0;
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}
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// if we missed a fragment, dump the message
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if ( fragmentStart != chan->fragmentLength ) {
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if ( showdrop->integer || showpackets->integer ) {
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Com_Printf( "%s:Dropped a message fragment\n"
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, NET_AdrToString( chan->remoteAddress )
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, sequence);
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}
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// we can still keep the part that we have so far,
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// so we don't need to clear chan->fragmentLength
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return qfalse;
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}
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// copy the fragment to the fragment buffer
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if ( fragmentLength < 0 || msg->readcount + fragmentLength > msg->cursize ||
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chan->fragmentLength + fragmentLength > sizeof( chan->fragmentBuffer ) ) {
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if ( showdrop->integer || showpackets->integer ) {
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Com_Printf ("%s:illegal fragment length\n"
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, NET_AdrToString (chan->remoteAddress ) );
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}
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return qfalse;
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}
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memcpy( chan->fragmentBuffer + chan->fragmentLength,
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msg->data + msg->readcount, fragmentLength );
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chan->fragmentLength += fragmentLength;
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// if this wasn't the last fragment, don't process anything
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if ( fragmentLength == FRAGMENT_SIZE ) {
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return qfalse;
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}
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if ( chan->fragmentLength > msg->maxsize ) {
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Com_Printf( "%s:fragmentLength %i > msg->maxsize\n"
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, NET_AdrToString (chan->remoteAddress ),
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chan->fragmentLength );
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return qfalse;
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}
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// copy the full message over the partial fragment
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// make sure the sequence number is still there
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*(int *)msg->data = LittleLong( sequence );
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memcpy( msg->data + 4, chan->fragmentBuffer, chan->fragmentLength );
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msg->cursize = chan->fragmentLength + 4;
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chan->fragmentLength = 0;
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msg->readcount = 4; // past the sequence number
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return qtrue;
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}
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//
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// the message can now be read from the current message pointer
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//
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chan->incomingSequence = sequence;
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chan->incomingAcknowledged = sequence_ack;
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return qtrue;
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}
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//==============================================================================
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/*
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===================
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NET_CompareBaseAdr
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Compares without the port
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===================
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*/
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qboolean NET_CompareBaseAdr (netadr_t a, netadr_t b)
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{
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if (a.type != b.type)
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return qfalse;
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if (a.type == NA_LOOPBACK)
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return qtrue;
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Com_Printf ("NET_CompareBaseAdr: bad address type\n");
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return qfalse;
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}
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const char *NET_AdrToString (netadr_t a)
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{
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static char s[64];
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if (a.type == NA_LOOPBACK) {
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Com_sprintf (s, sizeof(s), "loopback");
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}
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return s;
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}
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qboolean NET_CompareAdr (netadr_t a, netadr_t b)
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{
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if (a.type != b.type)
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return qfalse;
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if (a.type == NA_LOOPBACK)
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return qtrue;
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Com_Printf ("NET_CompareAdr: bad address type\n");
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return qfalse;
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}
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qboolean NET_IsLocalAddress( netadr_t adr ) {
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return adr.type == NA_LOOPBACK;
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}
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/*
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=============================================================================
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LOOPBACK BUFFERS FOR LOCAL PLAYER
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=============================================================================
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*/
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qboolean NET_GetLoopPacket (netsrc_t sock, netadr_t *net_from, msg_t *net_message)
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{
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int i;
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loopback_t *loop;
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loop = &loopbacks[sock];
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//If read and write positions are the same, nothing left to read.
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if (loop->get == loop->send)
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return qfalse;
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//Get read position. Wrap if too close to end.
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i = loop->get;
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if(i > MAX_LOOPDATA - 4) {
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i = 0;
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}
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//Get length of packet.
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int length = *(int*)(loop->loopData + i);
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i += 4;
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//See if entire packet is at end of buffer or part is at the beginning.
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if(i + length <= MAX_LOOPDATA) {
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//Everything fits, full copy.
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memcpy (net_message->data, loop->loopData + i, length);
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net_message->cursize = length;
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i += length;
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loop->get = i;
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} else {
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//Doesn't all fit, partial copy
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const int copyToEnd = MAX_LOOPDATA - i;
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memcpy (net_message->data, loop->loopData + i, copyToEnd);
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memcpy ((char*)net_message->data + copyToEnd,
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loop->loopData, length - copyToEnd);
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net_message->cursize = length;
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loop->get = length - copyToEnd;
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}
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memset (net_from, 0, sizeof(*net_from));
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net_from->type = NA_LOOPBACK;
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return qtrue;
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}
|
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void NET_SendLoopPacket (netsrc_t sock, int length, const void *data, netadr_t to)
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{
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int i;
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loopback_t *loop;
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loop = &loopbacks[sock^1];
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|
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//Make sure there is enough free space in the buffer.
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int freeSpace;
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if(loop->send >= loop->get) {
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freeSpace = MAX_LOOPDATA - (loop->send - loop->get);
|
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} else {
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freeSpace = loop->get - loop->send;
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}
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assert(freeSpace > length);
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//Get write position. Wrap around if too close to end.
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i = loop->send;
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if(i > MAX_LOOPDATA - 4) {
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i = 0;
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}
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//Write length of packet.
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*(int*)(loop->loopData + i) = length;
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i += 4;
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//See if the whole packet will fit on the end of the buffer or if we
|
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//need to write part of it back at the beginning.
|
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if(i + length <= MAX_LOOPDATA) {
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//Everything fits, full copy.
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memcpy (loop->loopData + i, data, length);
|
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i += length;
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loop->send = i;
|
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} else {
|
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//Doesn't all fit, partial copy
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int copyToEnd = MAX_LOOPDATA - i;
|
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memcpy(loop->loopData + i, data, copyToEnd);
|
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memcpy(loop->loopData, (char*)data + copyToEnd, length - copyToEnd);
|
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loop->send = length - copyToEnd;
|
||||
}
|
||||
}
|
||||
|
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//=============================================================================
|
||||
|
||||
|
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void NET_SendPacket( netsrc_t sock, int length, const void *data, netadr_t to ) {
|
||||
|
||||
// sequenced packets are shown in netchan, so just show oob
|
||||
if ( showpackets->integer && *(int *)data == -1 ) {
|
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Com_Printf ("send packet %4i\n", length);
|
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}
|
||||
|
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if ( to.type == NA_LOOPBACK ) {
|
||||
NET_SendLoopPacket (sock, length, data, to);
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
===============
|
||||
NET_OutOfBandPrint
|
||||
|
||||
Sends a text message in an out-of-band datagram
|
||||
================
|
||||
*/
|
||||
void QDECL NET_OutOfBandPrint( netsrc_t sock, netadr_t adr, const char *format, ... ) {
|
||||
va_list argptr;
|
||||
char string[MAX_MSGLEN];
|
||||
|
||||
// set the header
|
||||
string[0] = (char) 0xff;
|
||||
string[1] = (char) 0xff;
|
||||
string[2] = (char) 0xff;
|
||||
string[3] = (char) 0xff;
|
||||
|
||||
va_start( argptr, format );
|
||||
vsprintf( string+4, format, argptr );
|
||||
va_end( argptr );
|
||||
|
||||
// send the datagram
|
||||
NET_SendPacket( sock, strlen( string ), string, adr );
|
||||
}
|
||||
|
||||
|
||||
|
||||
/*
|
||||
=============
|
||||
NET_StringToAdr
|
||||
|
||||
Traps "localhost" for loopback, passes everything else to system
|
||||
=============
|
||||
*/
|
||||
qboolean NET_StringToAdr( const char *s, netadr_t *a ) {
|
||||
if (!strcmp (s, "localhost")) {
|
||||
memset (a, 0, sizeof(*a));
|
||||
a->type = NA_LOOPBACK;
|
||||
return qtrue;
|
||||
}
|
||||
|
||||
a->type = NA_BAD;
|
||||
return qfalse;
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user