/* Copyright (C) 1996-1997 Id Software, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "quakedef.h" #ifdef _WIN32 #include "winquake.h" #else #include "unistd.h" #endif #define PACKET_HEADER 8 #define ANTISTUNBIAS 0x40000000 //adding this to sequences in the header ensures that we our packets will not get confused for stun or rtp packets. /* packet header ------------- 31 sequence 1 does this message contain a reliable payload 31 acknowledge sequence 1 acknowledge receipt of even/odd message 16 qport (only from client) 15 fragoffset (extension) 1 lastfrag (extension) The remote connection never knows if it missed a reliable message, the local side detects that it has been dropped by seeing a sequence acknowledge higher thatn the last reliable sequence, but without the correct even/odd bit for the reliable set. If the sender notices that a reliable message has been dropped, it will be retransmitted. It will not be retransmitted again until a message after the retransmit has been acknowledged and the reliable still failed to get there. if the sequence number is -1, the packet should be handled without a netcon The reliable message can be added to at any time by doing MSG_Write* (&netchan->message, ). If the message buffer is overflowed, either by a single message, or by multiple frames worth piling up while the last reliable transmit goes unacknowledged, the netchan signals a fatal error. Reliable messages are always placed first in a packet, then the unreliable message is included if there is sufficient room. To the receiver, there is no distinction between the reliable and unreliable parts of the message, they are just processed out as a single larger message. Illogical packet sequence numbers cause the packet to be dropped, but do not kill the connection. This, combined with the tight window of valid reliable acknowledgement numbers provides protection against malicious address spoofing. 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. fragmentation works like IP, offset and morefrags. offset is *8 (decode: (offset&~1)<<2 to avoid stomping on the morefrags flag, this allows really jumbo packets with 18 bits of length) */ int net_drop; cvar_t showpackets = CVAR("showpackets", "0"); cvar_t showdrop = CVAR("showdrop", "0"); cvar_t qport = CVARF("qport_", "0", CVAR_NOSAVE); #ifdef FTE_TARGET_WEB //with webrtc our packets will be layered over sctp(header=28,extras=20ish) over dtls(13), cvar_t net_mtu = CVARD("net_mtu", "1384", "Specifies a maximum udp payload size, above which packets will be fragmented. If routers all worked properly this could be some massive value, and some massive value may work really nicely for lans. Use smaller values than the default if you're connecting through nested tunnels through routers that fail with IP fragmentation."); #else cvar_t net_mtu = CVARD("net_mtu", "1440", "Specifies a maximum udp payload size, above which packets will be fragmented. If routers all worked properly this could be some massive value, and some massive value may work really nicely for lans. Use smaller values than the default if you're connecting through nested tunnels through routers that fail with IP fragmentation."); #endif cvar_t net_compress = CVARD("net_compress", "0", "Enables huffman compression of network packets."); cvar_t pext_vrinputs = CVARD("_pext_vrinputs", "0", "RENAME ME WHEN STABLE. Networks player inputs slightly differently, allowing for greater capabilities, particuarly vr controller info."); cvar_t pext_lerptime = CVARD("_pext_lerptime", "0", "RENAME ME WHEN STABLE. Sends timing hints for interpolation."); cvar_t pext_infoblobs = CVARD("_pext_infoblobs", "0", "RENAME ME WHEN STABLE. Enables the use of very large infokeys containing potentially invalid chars. Note that the userinfo is still limited by sv_userinfo_bytelimit and sv_userinfo_keylimit."); cvar_t pext_replacementdeltas = CVARD("pext_replacementdeltas", "1", "Enables the use of alternative nack-based entity deltas"); cvar_t pext_predinfo = CVARD("pext_predinfo", "1", "Enables some extra things to support prediction over NQ protocols."); extern cvar_t net_fakemtu; #if defined(HAVE_CLIENT) && defined(HAVE_SERVER) #define NET_SendPacket(c,s,d,t) NET_SendPacket((c&NCF_CLIENT)?cls.sockets:svs.sockets,s,d,t) #elif defined(HAVE_SERVER) #define NET_SendPacket(c,s,d,t) NET_SendPacket(svs.sockets,s,d,t) #else #define NET_SendPacket(c,s,d,t) NET_SendPacket(cls.sockets,s,d,t) #endif /*returns the entire bitmask of supported+enabled extensions*/ unsigned int Net_PextMask(unsigned int protover, qboolean fornq) { unsigned int mask = 0; if (protover == PROTOCOL_VERSION_FTE1) { #ifdef PEXT_SCALE mask |= PEXT_SCALE; #endif #ifdef PEXT_LIGHTSTYLECOL mask |= PEXT_LIGHTSTYLECOL; #endif #ifdef PEXT_TRANS mask |= PEXT_TRANS; #endif #ifdef PEXT_VIEW2 mask |= PEXT_VIEW2; #endif #ifdef PEXT_ACCURATETIMINGS #ifdef QUAKESTATS //needs stat_time mask |= PEXT_ACCURATETIMINGS; #endif #endif #ifdef PEXT_ZLIBDL mask |= PEXT_ZLIBDL; #endif #ifdef PEXT_FATNESS mask |= PEXT_FATNESS; #endif #ifdef PEXT_HLBSP mask |= PEXT_HLBSP; #endif #ifdef PEXT_Q2BSP mask |= PEXT_Q2BSP; #endif #ifdef PEXT_Q3BSP mask |= PEXT_Q3BSP; #endif #ifdef PEXT_TE_BULLET mask |= PEXT_TE_BULLET; #endif #ifdef PEXT_HULLSIZE mask |= PEXT_HULLSIZE; #endif #ifdef PEXT_SETVIEW mask |= PEXT_SETVIEW; #endif #ifdef PEXT_MODELDBL mask |= PEXT_MODELDBL; #endif #ifdef PEXT_SOUNDDBL mask |= PEXT_SOUNDDBL; #endif #ifdef PEXT_VWEAP mask |= PEXT_VWEAP; #endif #ifdef PEXT_FLOATCOORDS mask |= PEXT_FLOATCOORDS; #endif mask |= PEXT_SPAWNSTATIC2; mask |= PEXT_COLOURMOD; #if MAX_SPLITS > 1 mask |= PEXT_SPLITSCREEN; #endif mask |= PEXT_HEXEN2; mask |= PEXT_CUSTOMTEMPEFFECTS; mask |= PEXT_256PACKETENTITIES; mask |= PEXT_ENTITYDBL; mask |= PEXT_ENTITYDBL2; mask |= PEXT_SHOWPIC; mask |= PEXT_SETATTACHMENT; #ifdef PEXT_CHUNKEDDOWNLOADS mask |= PEXT_CHUNKEDDOWNLOADS; #endif #ifdef CSQC_DAT mask |= PEXT_CSQC; #endif #ifdef PEXT_DPFLAGS mask |= PEXT_DPFLAGS; #endif if (fornq) { //only ones that are tested mask &= #ifdef CSQC_DAT PEXT_CSQC | #endif #ifdef PEXT_Q2BSP PEXT_Q2BSP | #endif #ifdef PEXT_Q3BSP PEXT_Q3BSP | #endif PEXT_TE_BULLET | //qw's gunshot+explosions etc. PEXT_FLOATCOORDS | PEXT_HLBSP; //these all depend fully upon the player/entity deltas, and don't make sense for NQ. Implement PEXT2_REPLACEMENTDELTAS instead. mask &= ~(PEXT_SCALE|PEXT_TRANS|PEXT_ACCURATETIMINGS|PEXT_FATNESS|PEXT_HULLSIZE|PEXT_MODELDBL|PEXT_ENTITYDBL|PEXT_ENTITYDBL2|PEXT_COLOURMOD|PEXT_SPAWNSTATIC2|PEXT_256PACKETENTITIES|PEXT_SETATTACHMENT|PEXT_DPFLAGS); } } else if (protover == PROTOCOL_VERSION_FTE2) { mask |= PEXT2_PRYDONCURSOR; #ifdef PEXT2_VOICECHAT mask |= PEXT2_VOICECHAT; #endif mask |= PEXT2_SETANGLEDELTA; if (pext_replacementdeltas.ival) { mask |= PEXT2_REPLACEMENTDELTAS; if (/*fornq &&*/ pext_predinfo.ival) mask |= PEXT2_PREDINFO; } if (pext_infoblobs.ival) mask |= PEXT2_INFOBLOBS; if (pext_vrinputs.ival) mask |= PEXT2_VRINPUTS; if (pext_lerptime.ival) mask |= PEXT2_LERPTIME; if (MAX_CLIENTS != QWMAX_CLIENTS) mask |= PEXT2_MAXPLAYERS; if (mask & PEXT2_REPLACEMENTDELTAS) mask |= PEXT2_NEWSIZEENCODING; //use if we can mask |= PEXT2_STUNAWARE; if (fornq) { //only ones that are tested mask &= PEXT2_PRYDONCURSOR | PEXT2_VOICECHAT | PEXT2_SETANGLEDELTA | PEXT2_REPLACEMENTDELTAS | PEXT2_MAXPLAYERS | PEXT2_PREDINFO | PEXT2_NEWSIZEENCODING | PEXT2_VRINPUTS | PEXT2_LERPTIME; } // else // mask &= ~PEXT2_PREDINFO; } else if (protover == PROTOCOL_VERSION_EZQUAKE1) { mask = EZPEXT1_FLOATENTCOORDS;//|EZPEXT1_SETANGLEREASON; if (fornq) { mask &= ~EZPEXT1_FLOATENTCOORDS; //keep things simple. interactions are not defined. mask &= ~EZPEXT1_SETANGLEREASON; //potentially breaks too many nq mods. don't encourage it. } } return mask; } /* =============== Netchan_Init =============== */ void Netchan_Init (void) { static char qportstr[16]; int port; // pick a port value that should be nice and random #ifdef _WIN32 port = (time(NULL)) & 0xffff; #else port = ((int)(getpid()+getuid()*1000) * time(NULL)) & 0xffff; #endif Q_snprintfz(qportstr, sizeof(qportstr), "%i", port); qport.enginevalue = qportstr; Cvar_Register (&pext_predinfo, "Protocol Extensions"); Cvar_Register (&pext_replacementdeltas, "Protocol Extensions"); Cvar_Register (&pext_infoblobs, "Protocol Extensions"); Cvar_Register (&pext_vrinputs, "Protocol Extensions"); Cvar_Register (&pext_lerptime, "Protocol Extensions"); Cvar_Register (&showpackets, "Networking"); Cvar_Register (&showdrop, "Networking"); Cvar_Register (&qport, "Networking"); Cvar_Register (&net_mtu, "Networking"); Cvar_Register (&net_compress, "Networking"); } /* =============== Netchan_OutOfBand Sends an out-of-band datagram ================ */ void Netchan_OutOfBand (unsigned int ncflags, netadr_t *adr, int length, const qbyte *data) { sizebuf_t send; qbyte send_buf[MAX_QWMSGLEN + PACKET_HEADER]; // write the packet header memset(&send, 0, sizeof(send)); send.data = send_buf; send.maxsize = sizeof(send_buf); send.cursize = 0; MSG_WriteLong (&send, -1); // -1 sequence means out of band SZ_Write (&send, data, length); // send the datagram //zoid, no input in demo playback mode #ifndef SERVERONLY if (!cls.demoplayback) #endif NET_SendPacket (ncflags, send.cursize, send.data, adr); } /* =============== Netchan_OutOfBandPrint Sends a text message in an out-of-band datagram ================ */ void VARGS Netchan_OutOfBandPrint (unsigned int ncflags, netadr_t *adr, char *format, ...) { va_list argptr; static char string[8192]; // ??? why static? va_start (argptr, format); vsnprintf (string,sizeof(string)-1, format,argptr); va_end (argptr); Netchan_OutOfBand (ncflags, adr, strlen(string), (qbyte *)string); } #ifndef CLIENTONLY void VARGS Netchan_OutOfBandTPrintf (unsigned int ncflags, netadr_t *adr, int language, translation_t text, ...) { va_list argptr; static char string[8192]; // ??? why static? const char *format = langtext(text, language); string[0] = A2C_PRINT; va_start (argptr, text); vsnprintf (string+1,sizeof(string)-1, format,argptr); va_end (argptr); Netchan_OutOfBand (ncflags, adr, strlen(string), (qbyte *)string); } #endif size_t Netchan_GetMaxUnreliable(netchan_t *chan) { //returns the maximum unreliable size we should be aiming for #ifdef HAVE_SERVER //debug prints if (!(chan->flags&NCF_CLIENT) && chan == &svs.clients[0].netchan) { static int oldmtu; if (oldmtu != chan->mtu_cur) { Con_DPrintf("Player0 MTU changed %i->%i\n", oldmtu, chan->mtu_cur); oldmtu = chan->mtu_cur; } } #endif // if (chan->remote_address.type == NA_LOOPBACK) // return ~0u; //our client supports big stuff. demos don't really care either so its fine. if (chan->incoming_acknowledged > chan->last_reliable_sequence && chan->incoming_reliable_acknowledged != chan->reliable_sequence) { //we want to send a reliable... if (chan->reliable_length) //one will be resent return chan->mtu_cur - chan->reliable_length; if (chan->message.cursize) //a new one will go out return chan->mtu_cur - chan->message.cursize; } return chan->mtu_cur; } /* ============== Netchan_Setup called to open a channel to a remote system ============== */ void Netchan_Setup (unsigned int flags, netchan_t *chan, netadr_t *adr, int qport, unsigned int mtu) { memset (chan, 0, sizeof(*chan)); chan->flags = flags; chan->remote_address = *adr; chan->last_received = realtime; #ifdef NQPROT chan->nqreliable_allowed = true; #endif chan->incoming_unreliable = -1; if (flags&NCF_CLIENT) chan->outgoing_sequence = 1; //so the first one doesn't get dropped. if (adr->prot == NP_KEXLAN) chan->qportsize = 0; else chan->qportsize = 2; chan->qport = qport; //input mtu is the expected 'udp data size' if (mtu<64 || mtu > 0xffff) mtu = MAX_QWMSGLEN; mtu = max(mtu, 508); //compute the minimum mtu for the address type if (adr->type == NA_IP) chan->mtu_min = 508; //576 - 20..60(IP header) - 8(udp header) else if (adr->type == NA_IPV6) chan->mtu_min = 1200; else if (adr->type == NA_IPX) chan->mtu_min = 1450; #ifdef SUPPORT_ICE else if (adr->type == NA_ICE) chan->mtu_min = 508; //match ipv4 here... #endif else if (adr->type == NA_LOOPBACK) chan->mtu_min = 8192; else chan->mtu_min = 1450; if (chan->mtu_min < 1024) chan->mtu_min = 1200; //the internet is ethernet. if you can't deal with ipv6's limit then your connection is seriously dodgy. plus this lets us be a bit more agressive. mtu -= PACKET_HEADER; //Note: This is not considered in vanilla - meaning net_mtu should be 1458 to match it (which will probably cause PTB issues). if (flags&NCF_CLIENT) mtu -= chan->qportsize; if (flags&NCF_FRAGABLE) mtu -= 2; #ifdef SUPPORT_ICE if (adr->type == NA_ICE) mtu -= 48+12; //fixme: check if we're actually using the dtls and sctp layers or not. else #endif { if (adr->prot == NP_DTLS || adr->prot == NP_TLS) mtu -= 48; } chan->mtu_min = min(mtu, chan->mtu_min); chan->mtu_cur = mtu; //try to use the requested size to begin with. if it fails (probably on the realibles) then we'll allow it to drop chan->mtu_max = mtu; //don't grow beyond what the user set. we're not aware of multiple paths nor are we tracking packetloss rates so if its partly wrong they'll get a load more loss, so don't be agressive here. let the user do that themselves! chan->mtu_reprobetime = realtime; //try and grow the effective mtu after a bit (route may have changed) chan->message.data = chan->message_buf; chan->message.allowoverflow = true; chan->message.maxsize = min(chan->mtu_cur, sizeof(chan->message_buf)); } /* =============== Netchan_CanPacket Returns true if the bandwidth choke isn't active ================ */ #define MAX_BACKUP 200 qboolean Netchan_CanPacket (netchan_t *chan, int rate) { if (chan->remote_address.type == NA_LOOPBACK) return true; //don't ever drop packets due to possible routing problems when there is no routing. if (!rate) return true; if (chan->cleartime < realtime + 0.25)//(MAX_BACKUP/(float)rate)) return true; return false; } int Netchan_CanBytes (netchan_t *chan, int rate) { const double slop = 0.25; if (chan->remote_address.type == NA_LOOPBACK) return 0x7fffffff; //don't ever drop packets due to possible routing problems when there is no routing. if (!rate) return 0x7fffffff; return ((realtime+slop)-chan->cleartime)*rate; } void Netchan_Block (netchan_t *chan, int bytes, int rate) { if (rate) { if (chan->cleartime < realtime-0.25) //0.25 allows it to be a little bursty. chan->cleartime = realtime + (bytes/(float)rate); else chan->cleartime += bytes/(float)rate; } } /* =============== Netchan_CanReliable Returns true if the bandwidth choke isn't ================ */ qboolean Netchan_CanReliable (netchan_t *chan, int rate) { if (chan->reliable_length) return false; // waiting for ack return Netchan_CanPacket (chan, rate); } #ifdef SERVERONLY qboolean ServerPaused(void); #endif #ifdef NQPROT size_t ZLib_DecompressBuffer(qbyte *in, size_t insize, qbyte *out, size_t maxoutsize); enum nqnc_packettype_e NQNetChan_Process(netchan_t *chan) { int header; int sequence; int drop; chan->bytesin += net_message.cursize; MSG_BeginReading (&net_message, chan->netprim); header = LongSwap(MSG_ReadLong()); if (header & NETFLAG_CTL) return NQNC_IGNORED; //huh? #ifdef HAVE_CLIENT if (header & NETFLAG_ZLIB) { //note: qex gets the size header wrong here. qbyte *tmp; if (net_message.cursize <= PACKET_HEADER || net_message.cursize != PACKET_HEADER+(header & NETFLAG_LENGTH_MASK)) return NQNC_IGNORED; //huh? /*redundantsequence =*/ MSG_ReadLong(); //wasting 4 bytes... #ifdef AVAIL_ZLIB tmp = alloca(0xffff); //note: its zlib rather than raw deflate (wasting a further 6 bytes...). net_message.cursize = ZLib_DecompressBuffer(net_message.data+8, net_message.cursize-8, tmp, 0xffff); if (net_message.cursize < PACKET_HEADER) { if (chan->flags&NCF_CLIENT) { //clients can just throw an error. the server will appear dead if we try to just ignore it. Host_EndGame("QuakeEx netchan decompression error"); return NQNC_IGNORED; } else { //inject a disconnect request. clients shouldn't be sending this anyway. net_message.data[8] = clc_disconnect; net_message.cursize = 9; return NQNC_RELIABLE; } } memcpy(net_message.data, tmp, net_message.cursize); MSG_BeginReading (&net_message, chan->netprim); header = LongSwap(MSG_ReadLong()); //re-read the now-decompressed copy of the header for the real flags #else if (chan->flags&NCF_CLIENT) Host_EndGame("NQNetChan_Process: zlib not enabled at compile time"); else Con_Printf("QuakeEx netchan decompression error"); net_message.data[8] = (chan->flags&NCF_CLIENT)?svc_disconnect:clc_disconnect; net_message.cursize = 9; return NQNC_RELIABLE; #endif } #endif if (net_message.cursize != (header & NETFLAG_LENGTH_MASK)) return NQNC_IGNORED; //size was wrong, couldn't have been ours. sequence = LongSwap(MSG_ReadLong()); if (header & NETFLAG_ACK) { if (sequence == chan->reliable_sequence) { chan->reliable_start += MAX_NQDATAGRAM; if (chan->reliable_start >= chan->reliable_length) { chan->reliable_length = 0; //they got the entire message chan->reliable_start = 0; } chan->incoming_reliable_acknowledged = chan->reliable_sequence; chan->reliable_sequence++; chan->nqreliable_allowed = true; chan->last_received = realtime; } else if (sequence < chan->reliable_sequence) { if (showdrop.ival) Con_Printf("Stale ack recieved\n"); } else if (sequence > chan->reliable_sequence) { if (showdrop.ival) Con_Printf("Future ack recieved\n"); } if (showpackets.value) Con_Printf ("in %s a=%i %i\n" , (chan->flags&NCF_CLIENT)?"s2c":"c2s" , sequence , 0); return NQNC_ACK; //don't try execing the 'payload'. I hate ack packets. } if (header & NETFLAG_UNRELIABLE) { if (sequence <= chan->incoming_unreliable) { if (showdrop.ival) Con_Printf("Stale datagram recieved (%i<=%i)\n", sequence, chan->incoming_unreliable); return NQNC_IGNORED; } drop = sequence - chan->incoming_unreliable - 1; if (drop > 0) { if (showdrop.ival) Con_Printf("Dropped %i datagrams (%i - %i)\n", drop, chan->incoming_unreliable+1, sequence-1); chan->drop_count += drop; } chan->incoming_unreliable = sequence; // chan->frame_latency = chan->frame_latency*OLD_AVG // + (chan->outgoing_sequence-sequence_ack)*(1.0-OLD_AVG); chan->frame_rate = chan->frame_rate*OLD_AVG + (realtime-chan->last_received)*(1.0-OLD_AVG); chan->last_received = realtime; chan->incoming_acknowledged++; if (showpackets.value) Con_Printf ("in %s u=%i %i\n" , (chan->flags&NCF_CLIENT)?"c2s":"s2c" , chan->incoming_unreliable , net_message.cursize); return NQNC_UNRELIABLE; } if (header & NETFLAG_DATA) { int runt[2]; //always reply. a stale sequence probably means our ack got lost. runt[0] = BigLong(NETFLAG_ACK | 8); runt[1] = BigLong(sequence); NET_SendPacket (chan->flags, 8, runt, &net_from); if (showpackets.value) Con_Printf ("out %s a=%i %i\n" , (chan->flags&NCF_CLIENT)?"c2s":"s2c" , sequence , 0); chan->last_received = realtime; if (sequence == chan->incoming_reliable_sequence) { chan->incoming_reliable_sequence++; if (chan->in_fragment_length + net_message.cursize-8 >= sizeof(chan->in_fragment_buf)) { chan->fatal_error = true; return NQNC_IGNORED; } memcpy(chan->in_fragment_buf + chan->in_fragment_length, net_message.data+8, net_message.cursize-8); chan->in_fragment_length += net_message.cursize-8; if (header & NETFLAG_EOM) { SZ_Clear(&net_message); SZ_Write(&net_message, chan->in_fragment_buf, chan->in_fragment_length); chan->in_fragment_length = 0; MSG_BeginReading(&net_message, chan->netprim); if (showpackets.value) Con_Printf ("in %s r=%i %i\n" , (chan->flags&NCF_CLIENT)?"s2c":"c2s" , sequence , net_message.cursize); return NQNC_RELIABLE; //we can read it now } } else { if (showdrop.ival) Con_Printf("Stale reliable (%i)\n", sequence); } return NQNC_IGNORED; } return NQNC_IGNORED; //not supported. } #endif /* =============== Netchan_Transmit tries to send an unreliable message to a connection, and handles the transmition / retransmition of the reliable messages. A 0 length will still generate a packet and deal with the reliable messages. ================ */ int Netchan_Transmit (netchan_t *chan, int length, qbyte *data, int rate) { sizebuf_t send; qbyte send_buf[MAX_OVERALLMSGLEN + PACKET_HEADER]; qboolean send_reliable; char remote_adr[MAX_ADR_SIZE]; unsigned w1, w2, mtuseq; int i; neterr_t e; qboolean ismtuprobe; int dupes = chan->dupe; int availbytes = Netchan_CanBytes(chan, rate); int hsz; availbytes = max(0, availbytes); //make sure it can't go negative (clientside doesn't check rate limits much) #ifdef NQPROT if (chan->isnqprotocol) { int sentsize = 0; send.data = send_buf; send.maxsize = MAX_NQMSGLEN + PACKET_HEADER; send.cursize = 0; /*unreliables flood out, but reliables are tied to server sequences*/ if (chan->nqreliable_resendtime < realtime) chan->nqreliable_allowed = true; if (chan->nqreliable_allowed) { //consume the new reliable when we can. if (!chan->reliable_length && chan->message.cursize && chan->nqunreliableonly != 1) { if (chan->nqunreliableonly == 2) chan->nqunreliableonly = 1; memcpy (chan->reliable_buf, chan->message_buf, chan->message.cursize); chan->reliable_length = chan->message.cursize; chan->reliable_start = 0; chan->message.cursize = 0; } i = chan->reliable_length - chan->reliable_start; if (i>0) { MSG_WriteLong(&send, 0); MSG_WriteLong(&send, LongSwap(chan->reliable_sequence)); //limit the payload length to nq's datagram max size. //relax the limitation if its reliable (ie: over tcp) where its assumed to have no real limit (beware tunnels) if (i > MAX_NQDATAGRAM && !NET_AddrIsReliable(&chan->remote_address)) i = MAX_NQDATAGRAM; SZ_Write (&send, chan->reliable_buf+chan->reliable_start, i); if (chan->reliable_start+i == chan->reliable_length) { if (send.cursize + length < send.maxsize) { //throw the unreliable packet into the same one as the reliable (but not sent reliably) // SZ_Write (&send, data, length); // length = 0; } *(int*)send_buf = BigLong(NETFLAG_DATA | NETFLAG_EOM | send.cursize); } else *(int*)send_buf = BigLong(NETFLAG_DATA | send.cursize); chan->bytesout += send.cursize; sentsize += send.cursize; if (showpackets.value) Con_Printf ("out %s r s=%i %i\n" , (chan->flags&NCF_CLIENT)?"c2s":"s2c" , chan->reliable_sequence , send.cursize); chan->nqreliable_allowed = false; chan->nqreliable_resendtime = realtime + 0.3; //resend reliables after 0.3 seconds. nq transports suck. FIXME: reduce to pingtime if (NET_SendPacket (chan->flags, send.cursize, send.data, &chan->remote_address) == NETERR_SENT && ( NET_AddrIsReliable(&chan->remote_address) || chan->nqunreliableonly==3 )) { //if over tcp (or we're dropping the connection), everything is assumed to be reliable. pretend it got acked now. //if we get an ack later, then who cares. chan->reliable_start += i; if (chan->reliable_start >= chan->reliable_length) { chan->reliable_length = 0; //they got the entire message chan->reliable_start = 0; } chan->incoming_reliable_acknowledged = chan->reliable_sequence; chan->reliable_sequence++; chan->nqreliable_allowed = true; } send.cursize = 0; } } //send out the unreliable (if still unsent) if (length) { MSG_WriteLong(&send, 0); MSG_WriteLong(&send, LongSwap(chan->outgoing_unreliable)); chan->outgoing_unreliable++; SZ_Write (&send, data, length); *(int*)send_buf = BigLong(NETFLAG_UNRELIABLE | send.cursize); for (i = -1, e = NETERR_SENT; i < dupes && e == NETERR_SENT; i++) e = NET_SendPacket (chan->flags, send.cursize, send.data, &chan->remote_address); sentsize += send.cursize*i; if (e == NETERR_MTU && chan->mtu_cur > chan->mtu_min) { //yay, router works properly. unfortunately we don't know the exact size so keep retrying with a slightly smaller value until it goes through... chan->mtu_cur = max(chan->mtu_min, chan->mtu_cur-10); Con_Printf("Reducing MSS to %i\n", chan->mtu_cur); } if (showpackets.value) Con_Printf ("out %s u=%i %i\n" , (chan->flags&NCF_CLIENT)?"c2s":"s2c" , chan->outgoing_unreliable-1 , send.cursize); send.cursize = 0; } chan->bytesout += sentsize; Netchan_Block(chan, sentsize, rate); return sentsize; } #endif // check for message overflow if (chan->message.overflowed) { chan->fatal_error = true; Con_TPrintf ("%s: Outgoing message overflow\n" , NET_AdrToString (remote_adr, sizeof(remote_adr), &chan->remote_address)); return 0; } // if the remote side dropped the last reliable message, resend it send_reliable = false; if (chan->incoming_acknowledged > chan->last_reliable_sequence && chan->incoming_reliable_acknowledged != chan->reliable_sequence) send_reliable = true; //they acked a later packet without acking the reliable... // if the reliable transmit buffer is empty, copy the current message out if (!chan->reliable_length && chan->message.cursize) { memcpy (chan->reliable_buf, chan->message_buf, chan->message.cursize); chan->reliable_length = chan->message.cursize; chan->message.cursize = 0; chan->reliable_sequence ^= 1; send_reliable = true; chan->mtu_resends=0; } if (send_reliable && chan->remote_address.prot == NP_KEXLAN) //FIXME: use with webrtc too - sctp can avoid the round-trip delay. #ifndef SERVERONLY if (!cls.demoplayback) #endif { if (chan->reliable_length) { send.data = send_buf; send.maxsize = sizeof(send_buf); send.cursize = 0; MSG_WriteLong (&send, 1u<<31); MSG_WriteLong (&send, 1u<<31); SZ_Write (&send, chan->reliable_buf, chan->reliable_length); if (NETERR_SENT == NET_SendPacket (chan->flags, send.cursize, send.data, &chan->remote_address)) chan->reliable_length = 0; //the lower layer will handle any retransmission for us. } send_reliable = 0; chan->incoming_reliable_sequence = 0; } // write the packet header send.data = send_buf; send.maxsize = PACKET_HEADER + ((chan->flags&NCF_CLIENT)?chan->qportsize:0) + ((chan->flags&NCF_FRAGABLE)?2:0); send.maxsize += chan->mtu_cur; send.cursize = 0; mtuseq = chan->outgoing_sequence&(countof(chan->sentsizes)-1); for (; (chan->outgoing_sequence_last&(countof(chan->sentsizes)-1)) != mtuseq; chan->outgoing_sequence_last++) chan->sentsizes[chan->outgoing_sequence_last&(countof(chan->sentsizes)-1)] = 0; //lost c2s or something, gaps now. w1 = chan->outgoing_sequence | (send_reliable<<31); w2 = chan->incoming_sequence | (chan->incoming_reliable_sequence<<31); if (chan->flags&NCF_STUNAWARE) { w1 = BigLong(w1+ANTISTUNBIAS); w2 = BigLong(w2); } chan->outgoing_sequence++; MSG_WriteLong (&send, w1); MSG_WriteLong (&send, w2); hsz = 8; // send the qport if we are a client #ifndef SERVERONLY if (chan->flags&NCF_CLIENT) { if (chan->qportsize == 2) MSG_WriteShort (&send, chan->qport); else if (chan->qportsize == 1) MSG_WriteByte (&send, chan->qport&0xff); hsz += chan->qportsize; } #endif if (chan->flags&NCF_FRAGABLE) { //allow the max size to be bigger, sending everything available send.maxsize = MAX_OVERALLMSGLEN-100; MSG_WriteShort(&send, 0); hsz += 2; } // copy the reliable message to the packet first if (send_reliable) { if (send.maxsize - send.cursize < chan->reliable_length) { if (!chan->fatal_error) { chan->fatal_error = true; Con_TPrintf ("%s: Path MTU is lower than %u\n" , NET_AdrToString (remote_adr, sizeof(remote_adr), &chan->remote_address), chan->reliable_length); } chan->outgoing_sequence--; return 0; } SZ_Write (&send, chan->reliable_buf, chan->reliable_length); chan->last_reliable_sequence = chan->outgoing_sequence; if (chan->mtu_resends > 5) { //getting blackholed? if (chan->mtu_cur > chan->mtu_min) { //reset the mtu, and re-enable probes to get it back up to something usable. chan->mtu_cur = chan->mtu_min; // chan->mtu_cur = max(chan->mtu_min, min(send.cursize, chan->mtu_cur-16)); Con_DPrintf("Reliables Blackholed? Reducing MSS to %i\n", chan->mtu_cur); chan->mtu_probes = 0; //and try and grow it again. } //chan->mtu_resends = 0; } chan->mtu_resends++; } if (chan->outgoing_sequence - chan->incoming_acknowledged > 128 && chan->mtu_cur > chan->mtu_min) { chan->mtu_cur = chan->mtu_min; // chan->mtu_cur = max(chan->mtu_min, min(send.cursize, chan->mtu_cur-16)); Con_DPrintf("MTU blackhole? Reducing MSS to %i\n", chan->mtu_cur); chan->mtu_probes = 0; //and try and grow it again. } // add the unreliable part if space is available if (send.maxsize - send.cursize >= length) SZ_Write (&send, data, length); ismtuprobe = false; if (chan->mtu_reprobetime < realtime) { chan->mtu_probes = min(chan->mtu_probes,4); chan->mtu_reprobetime = realtime + 30; } if (!send_reliable/*reliables depend on round trip times, don't risk losing them*/ && chan->incoming_acknowledged >= chan->outgoing_mtu_probe+chan->mtu_probes/*not still waiting for one, slow down a bit if they're dropping.*/ && chan->mtu_cur < chan->mtu_max && chan->mtu_probes < 5/*give up if its just not growing*/) { int targsize = min(chan->mtu_max, chan->mtu_cur+16); int padsize = (hsz+targsize)-send.cursize; if (padsize > 0 && targsize <= send.maxsize) { if (chan->flags&NCF_CLIENT) Q_memset (SZ_GetSpace(&send,padsize),clc_nop,padsize); else Q_memset (SZ_GetSpace(&send,padsize),svc_nop,padsize); ismtuprobe = true; //don't do our fragmentation stuff. chan->mtu_probes++; chan->outgoing_mtu_probe = chan->outgoing_sequence; chan->mtu_reprobetime = realtime + 30; Con_DPrintf("Sending mtu probe\n"); } } // send the datagram // i = chan->outgoing_sequence & (MAX_LATENT-1); // chan->outgoing_size[i] = send.cursize; // chan->outgoing_time[i] = realtime; #ifdef HUFFNETWORK if (chan->compresstable) { //int oldsize = send.cursize; Huff_CompressPacket(chan->compresstable, &send, 8 + ((chan->flags&NCF_CLIENT)?2:0) + (chan->flags&NCF_FRAGABLE?2:0)); // Con_Printf("%i becomes %i\n", oldsize, send.cursize); // Huff_DecompressPacket(&send, (chan->sock == NS_CLIENT)?10:8); } #endif e = NETERR_SENT; //zoid, no input in demo playback mode #ifndef SERVERONLY if (!cls.demoplayback) #endif { dupes = min(chan->dupe, availbytes / send.cursize); if (ismtuprobe || !(chan->flags&NCF_FRAGABLE))// || send.cursize < ((chan->mtu - hsz)&~7)) { //vanilla sends for (i = -1; i < dupes && e == NETERR_SENT; i++) e = NET_SendPacket (chan->flags, send.cursize, send.data, &chan->remote_address); //ipv4 'guarentees' mtu sizes of at least 560ish. //our reliable/backbuf messages are limited to 1024 bytes. //this means that large reliables may be unsendable. if (e == NETERR_MTU && send.cursize-hsz > chan->mtu_min) { chan->mtu_cur = max(chan->mtu_min, send.cursize-hsz-10); chan->mtu_max = min(chan->mtu_max, chan->mtu_cur); //don't try growing past it Con_Printf("Reducing MSS to %i\n", chan->mtu_cur); } chan->sentsizes[mtuseq] = send.cursize-hsz; send.cursize += send.cursize * i; } else { //fte's fragmentaton protocol int offset = 0, no; qboolean more; int outbytes = 0; int fragbytes; /*FIXME: splurge over a number of frames, if we have an outgoing reliable*/ /*send the additional parts, adding new headers within the previous packet*/ do { no = offset + chan->mtu_cur - hsz; if (no < send.cursize-hsz) { no &= ~7; more = true; } else { //this is the last... no = send.cursize-hsz; more = false; } *(int*)&send.data[(offset) + 0] = LittleLong(w1); *(int*)&send.data[(offset) + 4] = LittleLong(w2); #ifndef SERVERONLY if (chan->flags&NCF_CLIENT) { if (chan->qportsize == 2) *(short*)&send.data[offset + hsz-4] = LittleShort(chan->qport); else if (chan->qportsize == 1) *(qbyte*)&send.data[offset + hsz-3] = chan->qport&0xff; } #endif *(short*)&send.data[offset + hsz-2] = LittleShort((offset>>2) | (more?1:0)); if (e == NETERR_SENT) { for (i = -1; i < dupes && e == NETERR_SENT; i++) { fragbytes = (no - offset) + hsz; e = NET_SendPacket (chan->flags, fragbytes, send.data + offset, &chan->remote_address); if (e == NETERR_MTU && !offset && chan->mtu_cur > chan->mtu_min) { chan->mtu_cur = max(chan->mtu_min, chan->mtu_cur-16); chan->mtu_max = min(chan->mtu_max, chan->mtu_cur); //don't try growing past it Con_Printf("Reducing MSS to %i\n", chan->mtu_cur); no = offset; more = true; e = NETERR_SENT; //... keep trying... break; } if (!offset) chan->sentsizes[mtuseq] = fragbytes-hsz; outbytes += fragbytes; } } offset = no; } while(more); send.cursize = outbytes; } } if (e == NETERR_SENT) { if (send_reliable && NET_AddrIsReliable(&chan->remote_address)) chan->reliable_length = 0; //we know the peer will receive it. don't worry about waiting for their acks. chan->bytesout += send.cursize; Netchan_Block(chan, send.cursize, rate); } #ifdef SERVERONLY if (ServerPaused()) chan->cleartime = realtime; #endif if (showpackets.value) { char *errtext; switch(e) { case NETERR_SENT: errtext = ""; break; case NETERR_NOROUTE: errtext = " unroutable"; break; case NETERR_DISCONNECTED: errtext = " disconnected"; break; case NETERR_MTU: errtext = " mss exceeded"; break; case NETERR_CLOGGED: errtext = " conjestion"; break; default: errtext = " unk error"; break; } Con_Printf ("%f %s --> s=%i(%i) a=%i(%i) %i%s\n" , Sys_DoubleTime() , (chan->flags&NCF_CLIENT)?"c2s":"s2c" , chan->outgoing_sequence , send_reliable , chan->incoming_sequence , chan->incoming_reliable_sequence , send.cursize, errtext); } return send.cursize; } /* ================= Netchan_Process called when the current net_message is from remote_address modifies net_message so that it points to the packet payload ================= */ qboolean Netchan_Process (netchan_t *chan) { unsigned sequence, sequence_ack; unsigned reliable_ack, reliable_message; char adr[MAX_ADR_SIZE]; int offset; int oob_reliable; if ( #ifndef SERVERONLY !cls.demoplayback && #endif !NET_CompareAdr (&net_from, &chan->remote_address)) return false; chan->bytesin += net_message.cursize; // get sequence numbers MSG_BeginReading (&net_message, chan->netprim); sequence = MSG_ReadLong (); sequence_ack = MSG_ReadLong (); if (chan->flags&NCF_STUNAWARE) { sequence = BigLong(sequence); if (!(sequence&ANTISTUNBIAS)) return false; sequence -= ANTISTUNBIAS; sequence_ack = BigLong(sequence_ack); } oob_reliable = (sequence == (1u<<31) && sequence_ack == (1u<<31)); // skip over the qport if we are a server (its handled elsewhere) #ifndef CLIENTONLY if (!(chan->flags&NCF_CLIENT)) MSG_ReadSkip (chan->qportsize); #endif if (chan->flags&NCF_FRAGABLE) offset = (unsigned short)MSG_ReadShort(); else offset = 0; reliable_message = sequence >> 31; reliable_ack = sequence_ack >> 31; sequence &= ~(1u<<31); sequence_ack &= ~(1u<<31); if (showpackets.value) Con_Printf ("%f %s <-- s=%i(%i) a=%i(%i) %i%s\n" , Sys_DoubleTime() , (chan->flags&NCF_CLIENT)?"s2c":"c2s" , sequence , reliable_message , sequence_ack , reliable_ack , net_message.cursize , offset?" frag":""); // get a rate estimation #if 0 if (chan->outgoing_sequence - sequence_ack < MAX_LATENT) { int i; double time, rate; i = sequence_ack & (MAX_LATENT - 1); time = realtime - chan->outgoing_time[i]; time -= 0.1; // subtract 100 ms if (time <= 0) { // gotta be a digital link for <100 ms ping if (chan->rate > 1.0/5000) chan->rate = 1.0/5000; } else { if (chan->outgoing_size[i] < 512) { // only deal with small messages rate = chan->outgoing_size[i]/time; if (rate > 5000) rate = 5000; rate = 1.0/rate; if (chan->rate > rate) chan->rate = rate; } } } #endif // // discard stale or duplicated packets // if (oob_reliable) { //if its an oob reliable then its sequence numbers are screwy and bypass the dupe/etc check. if (NET_AddrIsReliable(&chan->remote_address)) ; //mostly for NP_KEXLAN. else { Con_TPrintf ("%s:Unexpected out-of-band reliable at %i\n" , NET_AdrToString (adr, sizeof(adr), &chan->remote_address) , chan->incoming_sequence); return false; } } else { int ssize = 0; if (sequence <= (unsigned)chan->incoming_sequence && !(reliable_message && chan->remote_address.prot == NP_KEXLAN)) //*sigh* reliables don't work properly here. { if (showdrop.value) Con_TPrintf ("%s:Out of order packet %i at %i\n" , NET_AdrToString (adr, sizeof(adr), &chan->remote_address) , sequence , chan->incoming_sequence); return false; } if (chan->outgoing_sequence-sequence_ack < countof(chan->sentsizes)-2) ssize = chan->sentsizes[sequence_ack&(countof(chan->sentsizes)-1)]; if (ssize && ssize > chan->mtu_cur) { chan->mtu_cur = ssize; Con_DPrintf("MTU confirmed to %i\n", chan->mtu_cur); chan->mtu_probes = 0; //start growing again. } } if (offset) { int len = net_message.cursize - MSG_GetReadCount(); qboolean more = false; if (offset & 1) { more = true; offset &= ~1; } offset = offset << 2; if (offset + len > sizeof(chan->in_fragment_buf)) /*stop the overflow*/ { if (showdrop.value) Con_Printf("Dropping packet - too many fragments\n"); return false; } if (chan->incoming_unreliable != sequence) { if (chan->in_fragment_length && showdrop.ival) Con_Printf("final fragment lost (%i). dropping entire packet\n", offset); /*sequence doesn't match, forget the old*/ chan->in_fragment_length = 0; chan->incoming_unreliable = sequence; } if (offset != chan->in_fragment_length) { if (showdrop.ival) Con_Printf("prior fragment lost (%i-%i). dropping entire packet\n", offset, chan->in_fragment_length); return false; /*dropped one*/ } memcpy(chan->in_fragment_buf + offset, net_message.data + MSG_GetReadCount(), len); chan->in_fragment_length += len; if (more) { /*nothing to process yet*/ return false; } memcpy(net_message.data, chan->in_fragment_buf, chan->in_fragment_length); net_message.currentbit = 0; net_message.cursize = chan->in_fragment_length; if (showpackets.value) Con_Printf ("<-- s=%i(%i) a=%i(%i) %i Recombined\n" , sequence , reliable_message , sequence_ack , reliable_ack , net_message.cursize); chan->incoming_unreliable = 0; chan->in_fragment_length = 0; } else { /*kill any pending reliable*/ chan->incoming_unreliable = 0; chan->in_fragment_length = 0; } // // dropped packets don't keep the message from being used // net_drop = sequence - (chan->incoming_sequence+1); if (net_drop > 0) { chan->drop_count += 1; if (showdrop.value) Con_TPrintf ("%s:Dropped %i packets at %i\n" , NET_AdrToString (adr, sizeof(adr), &chan->remote_address) , sequence-(chan->incoming_sequence+1) , sequence); } // // if the current outgoing reliable message has been acknowledged // clear the buffer to make way for the next // if (reliable_ack == (unsigned)chan->reliable_sequence) chan->reliable_length = 0; // it has been received // // if this message contains a reliable message, bump incoming_reliable_sequence // if (oob_reliable) //*sigh* reliables don't work properly here. ; //don't corrupt sequences/acks/etc. else { chan->incoming_sequence = sequence; chan->incoming_acknowledged = sequence_ack; chan->incoming_reliable_acknowledged = reliable_ack; if (reliable_message) chan->incoming_reliable_sequence ^= 1; } // // the message can now be read from the current message pointer // update statistics counters // chan->frame_latency = chan->frame_latency*OLD_AVG + (chan->outgoing_sequence-sequence_ack)*(1.0-OLD_AVG); chan->frame_rate = chan->frame_rate*OLD_AVG + (realtime-chan->last_received)*(1.0-OLD_AVG); chan->last_received = realtime; #ifdef HUFFNETWORK if (chan->compresstable) { // Huff_CompressPacket(&net_message, (chan->sock == NS_SERVER)?10:8); Huff_DecompressPacket(chan->compresstable, &net_message, MSG_GetReadCount()); } #endif return true; }