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Diffstat (limited to 'src/qcommon/net_chan.c')
| -rw-r--r-- | src/qcommon/net_chan.c | 801 |
1 files changed, 801 insertions, 0 deletions
diff --git a/src/qcommon/net_chan.c b/src/qcommon/net_chan.c new file mode 100644 index 0000000..869d87a --- /dev/null +++ b/src/qcommon/net_chan.c @@ -0,0 +1,801 @@ +/* +=========================================================================== +Copyright (C) 1999-2005 Id Software, Inc. +Copyright (C) 2000-2006 Tim Angus + +This file is part of Tremulous. + +Tremulous 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. + +Tremulous 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 Tremulous; if not, write to the Free Software +Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +=========================================================================== +*/ + +#include "q_shared.h" +#include "qcommon.h" + +/* + +packet header +------------- +4 outgoing sequence. high bit will be set if this is a fragmented message +[2 qport (only for client to server)] +[2 fragment start byte] +[2 fragment length. if < FRAGMENT_SIZE, this is the last fragment] + +if the sequence number is -1, the packet should be handled as an out-of-band +message instead of as part of a netcon. + +All fragments will have the same sequence numbers. + +The qport field is a workaround for bad address translating routers that +sometimes remap the client's source port on a packet during gameplay. + +If the base part of the net address matches and the qport matches, then the +channel matches even if the IP port differs. The IP port should be updated +to the new value before sending out any replies. + +*/ + + +#define MAX_PACKETLEN 1400 // max size of a network packet + +#define FRAGMENT_SIZE (MAX_PACKETLEN - 100) +#define PACKET_HEADER 10 // two ints and a short + +#define FRAGMENT_BIT (1<<31) + +cvar_t *showpackets; +cvar_t *showdrop; +cvar_t *qport; + +static char *netsrcString[2] = { + "client", + "server" +}; + +/* +=============== +Netchan_Init + +=============== +*/ +void Netchan_Init( int port ) { + port &= 0xffff; + showpackets = Cvar_Get ("showpackets", "0", CVAR_TEMP ); + showdrop = Cvar_Get ("showdrop", "0", CVAR_TEMP ); + qport = Cvar_Get ("net_qport", va("%i", port), CVAR_INIT ); +} + +/* +============== +Netchan_Setup + +called to open a channel to a remote system +============== +*/ +void Netchan_Setup( netsrc_t sock, netchan_t *chan, netadr_t adr, int qport ) { + Com_Memset (chan, 0, sizeof(*chan)); + + chan->sock = sock; + chan->remoteAddress = adr; + chan->qport = qport; + chan->incomingSequence = 0; + chan->outgoingSequence = 1; +} + +// TTimo: unused, commenting out to make gcc happy +#if 0 +/* +============== +Netchan_ScramblePacket + +A probably futile attempt to make proxy hacking somewhat +more difficult. +============== +*/ +#define SCRAMBLE_START 6 +static void Netchan_ScramblePacket( msg_t *buf ) { + unsigned seed; + int i, j, c, mask, temp; + int seq[MAX_PACKETLEN]; + + seed = ( LittleLong( *(unsigned *)buf->data ) * 3 ) ^ ( buf->cursize * 123 ); + c = buf->cursize; + if ( c <= SCRAMBLE_START ) { + return; + } + if ( c > MAX_PACKETLEN ) { + Com_Error( ERR_DROP, "MAX_PACKETLEN" ); + } + + // generate a sequence of "random" numbers + for (i = 0 ; i < c ; i++) { + seed = (119 * seed + 1); + seq[i] = seed; + } + + // transpose each character + for ( mask = 1 ; mask < c-SCRAMBLE_START ; mask = ( mask << 1 ) + 1 ) { + } + mask >>= 1; + for (i = SCRAMBLE_START ; i < c ; i++) { + j = SCRAMBLE_START + ( seq[i] & mask ); + temp = buf->data[j]; + buf->data[j] = buf->data[i]; + buf->data[i] = temp; + } + + // byte xor the data after the header + for (i = SCRAMBLE_START ; i < c ; i++) { + buf->data[i] ^= seq[i]; + } +} + +static void Netchan_UnScramblePacket( msg_t *buf ) { + unsigned seed; + int i, j, c, mask, temp; + int seq[MAX_PACKETLEN]; + + seed = ( LittleLong( *(unsigned *)buf->data ) * 3 ) ^ ( buf->cursize * 123 ); + c = buf->cursize; + if ( c <= SCRAMBLE_START ) { + return; + } + if ( c > MAX_PACKETLEN ) { + Com_Error( ERR_DROP, "MAX_PACKETLEN" ); + } + + // generate a sequence of "random" numbers + for (i = 0 ; i < c ; i++) { + seed = (119 * seed + 1); + seq[i] = seed; + } + + // byte xor the data after the header + for (i = SCRAMBLE_START ; i < c ; i++) { + buf->data[i] ^= seq[i]; + } + + // transpose each character in reverse order + for ( mask = 1 ; mask < c-SCRAMBLE_START ; mask = ( mask << 1 ) + 1 ) { + } + mask >>= 1; + for (i = c-1 ; i >= SCRAMBLE_START ; i--) { + j = SCRAMBLE_START + ( seq[i] & mask ); + temp = buf->data[j]; + buf->data[j] = buf->data[i]; + buf->data[i] = temp; + } +} +#endif + +/* +================= +Netchan_TransmitNextFragment + +Send one fragment of the current message +================= +*/ +void Netchan_TransmitNextFragment( netchan_t *chan ) { + msg_t send; + byte send_buf[MAX_PACKETLEN]; + int fragmentLength; + + // write the packet header + MSG_InitOOB (&send, send_buf, sizeof(send_buf)); // <-- only do the oob here + + MSG_WriteLong( &send, chan->outgoingSequence | FRAGMENT_BIT ); + + // send the qport if we are a client + if ( chan->sock == NS_CLIENT ) { + MSG_WriteShort( &send, qport->integer ); + } + + // copy the reliable message to the packet first + fragmentLength = FRAGMENT_SIZE; + if ( chan->unsentFragmentStart + fragmentLength > chan->unsentLength ) { + fragmentLength = chan->unsentLength - chan->unsentFragmentStart; + } + + MSG_WriteShort( &send, chan->unsentFragmentStart ); + MSG_WriteShort( &send, fragmentLength ); + MSG_WriteData( &send, chan->unsentBuffer + chan->unsentFragmentStart, fragmentLength ); + + // send the datagram + NET_SendPacket( chan->sock, send.cursize, send.data, chan->remoteAddress ); + + if ( showpackets->integer ) { + Com_Printf ("%s send %4i : s=%i fragment=%i,%i\n" + , netsrcString[ chan->sock ] + , send.cursize + , chan->outgoingSequence + , chan->unsentFragmentStart, fragmentLength); + } + + chan->unsentFragmentStart += fragmentLength; + + // this exit condition is a little tricky, because a packet + // that is exactly the fragment length still needs to send + // a second packet of zero length so that the other side + // can tell there aren't more to follow + if ( chan->unsentFragmentStart == chan->unsentLength && fragmentLength != FRAGMENT_SIZE ) { + chan->outgoingSequence++; + chan->unsentFragments = qfalse; + } +} + + +/* +=============== +Netchan_Transmit + +Sends a message to a connection, fragmenting if necessary +A 0 length will still generate a packet. +================ +*/ +void Netchan_Transmit( netchan_t *chan, int length, const byte *data ) { + msg_t send; + byte send_buf[MAX_PACKETLEN]; + + if ( length > MAX_MSGLEN ) { + Com_Error( ERR_DROP, "Netchan_Transmit: length = %i", length ); + } + chan->unsentFragmentStart = 0; + + // fragment large reliable messages + if ( length >= FRAGMENT_SIZE ) { + chan->unsentFragments = qtrue; + chan->unsentLength = length; + Com_Memcpy( chan->unsentBuffer, data, length ); + + // only send the first fragment now + Netchan_TransmitNextFragment( chan ); + + return; + } + + // write the packet header + MSG_InitOOB (&send, send_buf, sizeof(send_buf)); + + MSG_WriteLong( &send, chan->outgoingSequence ); + chan->outgoingSequence++; + + // send the qport if we are a client + if ( chan->sock == NS_CLIENT ) { + MSG_WriteShort( &send, qport->integer ); + } + + MSG_WriteData( &send, data, length ); + + // send the datagram + NET_SendPacket( chan->sock, send.cursize, send.data, chan->remoteAddress ); + + if ( showpackets->integer ) { + Com_Printf( "%s send %4i : s=%i ack=%i\n" + , netsrcString[ chan->sock ] + , send.cursize + , chan->outgoingSequence - 1 + , chan->incomingSequence ); + } +} + +/* +================= +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 ) { + chan->fragmentSequence = sequence; + chan->fragmentLength = 0; + } + + // if we missed a fragment, dump the message + if ( fragmentStart != chan->fragmentLength ) { + if ( showdrop->integer || showpackets->integer ) { + Com_Printf( "%s:Dropped a message fragment\n" + , NET_AdrToString( chan->remoteAddress )); + } + // we can still keep the part that we have so far, + // so we don't need to clear chan->fragmentLength + return qfalse; + } + + // copy the fragment to the fragment buffer + if ( fragmentLength < 0 || msg->readcount + fragmentLength > msg->cursize || + chan->fragmentLength + fragmentLength > sizeof( chan->fragmentBuffer ) ) { + if ( showdrop->integer || showpackets->integer ) { + Com_Printf ("%s:illegal fragment length\n" + , NET_AdrToString (chan->remoteAddress ) ); + } + return qfalse; + } + + Com_Memcpy( chan->fragmentBuffer + chan->fragmentLength, + msg->data + msg->readcount, fragmentLength ); + + chan->fragmentLength += fragmentLength; + + // if this wasn't the last fragment, don't process anything + if ( fragmentLength == FRAGMENT_SIZE ) { + return qfalse; + } + + if ( chan->fragmentLength > msg->maxsize ) { + Com_Printf( "%s:fragmentLength %i > msg->maxsize\n" + , NET_AdrToString (chan->remoteAddress ), + chan->fragmentLength ); + return qfalse; + } + + // copy the full message over the partial fragment + + // make sure the sequence number is still there + *(int *)msg->data = LittleLong( sequence ); + + Com_Memcpy( msg->data + 4, chan->fragmentBuffer, chan->fragmentLength ); + msg->cursize = chan->fragmentLength + 4; + chan->fragmentLength = 0; + msg->readcount = 4; // past the sequence number + msg->bit = 32; // past the sequence number + + // TTimo + // clients were not acking fragmented messages + chan->incomingSequence = sequence; + + return qtrue; + } + + // + // the message can now be read from the current message pointer + // + chan->incomingSequence = sequence; + + return qtrue; +} + + +//============================================================================== + +/* +=================== +NET_CompareBaseAdr + +Compares without the port +=================== +*/ +qboolean NET_CompareBaseAdr (netadr_t a, netadr_t b) +{ + if (a.type != b.type) + return qfalse; + + if (a.type == NA_LOOPBACK) + return qtrue; + + if (a.type == NA_IP) + { + if (a.ip[0] == b.ip[0] && a.ip[1] == b.ip[1] && a.ip[2] == b.ip[2] && a.ip[3] == b.ip[3]) + return qtrue; + return qfalse; + } + + if (a.type == NA_IPX) + { + if ((memcmp(a.ipx, b.ipx, 10) == 0)) + return qtrue; + return qfalse; + } + + + Com_Printf ("NET_CompareBaseAdr: bad address type\n"); + return qfalse; +} + +const char *NET_AdrToString (netadr_t a) +{ + static char s[64]; + + if (a.type == NA_LOOPBACK) { + Com_sprintf (s, sizeof(s), "loopback"); + } else if (a.type == NA_IP) { + Com_sprintf (s, sizeof(s), "%i.%i.%i.%i:%hu", + a.ip[0], a.ip[1], a.ip[2], a.ip[3], BigShort(a.port)); + } else { + Com_sprintf (s, sizeof(s), "%02x%02x%02x%02x.%02x%02x%02x%02x%02x%02x:%hu", + a.ipx[0], a.ipx[1], a.ipx[2], a.ipx[3], a.ipx[4], a.ipx[5], a.ipx[6], a.ipx[7], a.ipx[8], a.ipx[9], + BigShort(a.port)); + } + + return s; +} + + +qboolean NET_CompareAdr (netadr_t a, netadr_t b) +{ + if (a.type != b.type) + return qfalse; + + if (a.type == NA_LOOPBACK) + return qtrue; + + if (a.type == NA_IP) + { + if (a.ip[0] == b.ip[0] && a.ip[1] == b.ip[1] && a.ip[2] == b.ip[2] && a.ip[3] == b.ip[3] && a.port == b.port) + return qtrue; + return qfalse; + } + + if (a.type == NA_IPX) + { + if ((memcmp(a.ipx, b.ipx, 10) == 0) && a.port == b.port) + return qtrue; + return qfalse; + } + + Com_Printf ("NET_CompareAdr: bad address type\n"); + return qfalse; +} + + +qboolean NET_IsLocalAddress( netadr_t adr ) { + return adr.type == NA_LOOPBACK; +} + + + +/* +============================================================================= + +LOOPBACK BUFFERS FOR LOCAL PLAYER + +============================================================================= +*/ + +// there needs to be enough loopback messages to hold a complete +// gamestate of maximum size +#define MAX_LOOPBACK 16 + +typedef struct { + byte data[MAX_PACKETLEN]; + int datalen; +} loopmsg_t; + +typedef struct { + loopmsg_t msgs[MAX_LOOPBACK]; + int get, send; +} loopback_t; + +loopback_t loopbacks[2]; + + +qboolean NET_GetLoopPacket (netsrc_t sock, netadr_t *net_from, msg_t *net_message) +{ + int i; + loopback_t *loop; + + loop = &loopbacks[sock]; + + if (loop->send - loop->get > MAX_LOOPBACK) + loop->get = loop->send - MAX_LOOPBACK; + + if (loop->get >= loop->send) + return qfalse; + + i = loop->get & (MAX_LOOPBACK-1); + loop->get++; + + Com_Memcpy (net_message->data, loop->msgs[i].data, loop->msgs[i].datalen); + net_message->cursize = loop->msgs[i].datalen; + Com_Memset (net_from, 0, sizeof(*net_from)); + net_from->type = NA_LOOPBACK; + return qtrue; + +} + + +void NET_SendLoopPacket (netsrc_t sock, int length, const void *data, netadr_t to) +{ + int i; + loopback_t *loop; + + loop = &loopbacks[sock^1]; + + i = loop->send & (MAX_LOOPBACK-1); + loop->send++; + + Com_Memcpy (loop->msgs[i].data, data, length); + loop->msgs[i].datalen = length; +} + +//============================================================================= + +typedef struct packetQueue_s { + struct packetQueue_s *next; + int length; + byte *data; + netadr_t to; + int release; +} packetQueue_t; + +packetQueue_t *packetQueue = NULL; + +static void NET_QueuePacket( int length, const void *data, netadr_t to, + int offset ) +{ + packetQueue_t *new, *next = packetQueue; + + if(offset > 999) + offset = 999; + + new = S_Malloc(sizeof(packetQueue_t)); + new->data = S_Malloc(length); + Com_Memcpy(new->data, data, length); + new->length = length; + new->to = to; + new->release = Sys_Milliseconds() + offset; + new->next = NULL; + + if(!packetQueue) { + packetQueue = new; + return; + } + while(next) { + if(!next->next) { + next->next = new; + return; + } + next = next->next; + } +} + +void NET_FlushPacketQueue(void) +{ + packetQueue_t *last; + int now; + + while(packetQueue) { + now = Sys_Milliseconds(); + if(packetQueue->release >= now) + break; + Sys_SendPacket(packetQueue->length, packetQueue->data, + packetQueue->to); + last = packetQueue; + packetQueue = packetQueue->next; + Z_Free(last->data); + Z_Free(last); + } +} + +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 ) { + Com_Printf ("send packet %4i\n", length); + } + + if ( to.type == NA_LOOPBACK ) { + NET_SendLoopPacket (sock, length, data, to); + return; + } + if ( to.type == NA_BAD ) { + return; + } + + if ( sock == NS_CLIENT && cl_packetdelay->integer > 0 ) { + NET_QueuePacket( length, data, to, cl_packetdelay->integer ); + } + else if ( sock == NS_SERVER && sv_packetdelay->integer > 0 ) { + NET_QueuePacket( length, data, to, sv_packetdelay->integer ); + } + else { + Sys_SendPacket( length, data, to ); + } +} + +/* +=============== +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] = -1; + string[1] = -1; + string[2] = -1; + string[3] = -1; + + va_start( argptr, format ); + Q_vsnprintf( string+4, sizeof(string)-4, format, argptr ); + va_end( argptr ); + + // send the datagram + NET_SendPacket( sock, strlen( string ), string, adr ); +} + +/* +=============== +NET_OutOfBandPrint + +Sends a data message in an out-of-band datagram (only used for "connect") +================ +*/ +void QDECL NET_OutOfBandData( netsrc_t sock, netadr_t adr, byte *format, int len ) { + byte string[MAX_MSGLEN*2]; + int i; + msg_t mbuf; + + // set the header + string[0] = 0xff; + string[1] = 0xff; + string[2] = 0xff; + string[3] = 0xff; + + for(i=0;i<len;i++) { + string[i+4] = format[i]; + } + + mbuf.data = string; + mbuf.cursize = len+4; + Huff_Compress( &mbuf, 12); + // send the datagram + NET_SendPacket( sock, mbuf.cursize, mbuf.data, adr ); +} + +/* +============= +NET_StringToAdr + +Traps "localhost" for loopback, passes everything else to system +============= +*/ +qboolean NET_StringToAdr( const char *s, netadr_t *a ) { + qboolean r; + char base[MAX_STRING_CHARS]; + char *port; + + if (!strcmp (s, "localhost")) { + Com_Memset (a, 0, sizeof(*a)); + a->type = NA_LOOPBACK; + return qtrue; + } + + // look for a port number + Q_strncpyz( base, s, sizeof( base ) ); + port = strstr( base, ":" ); + if ( port ) { + *port = 0; + port++; + } + + r = Sys_StringToAdr( base, a ); + + if ( !r ) { + a->type = NA_BAD; + return qfalse; + } + + // inet_addr returns this if out of range + if ( a->ip[0] == 255 && a->ip[1] == 255 && a->ip[2] == 255 && a->ip[3] == 255 ) { + a->type = NA_BAD; + return qfalse; + } + + if ( port ) { + a->port = BigShort( (short)atoi( port ) ); + } else { + a->port = BigShort( PORT_SERVER ); + } + + return qtrue; +} + |