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Reformat of net_chan.c
This commit is contained in:
Yamagi Burmeister
parent
ee120a0bf0
commit
a42518434c
1 changed files with 152 additions and 186 deletions
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@ -1,78 +1,85 @@
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/*
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Copyright (C) 1997-2001 Id Software, Inc.
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; either version 2
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of the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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See the GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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* Copyright (C) 1997-2001 Id Software, Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or (at
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* your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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*
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* See the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
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* 02111-1307, USA.
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*
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* =======================================================================
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*
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* The low level network code
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*
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* =======================================================================
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*/
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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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31 sequence
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1 does this message contain a reliable payload
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31 acknowledge sequence
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1 acknowledge receipt of even/odd message
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16 qport
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The remote connection never knows if it missed a reliable message, the
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local side detects that it has been dropped by seeing a sequence acknowledge
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higher thatn the last reliable sequence, but without the correct even/odd
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bit for the reliable set.
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If the sender notices that a reliable message has been dropped, it will be
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retransmitted. It will not be retransmitted again until a message after
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the retransmit has been acknowledged and the reliable still failed to get there.
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if the sequence number is -1, the packet should be handled without a netcon
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The reliable message can be added to at any time by doing
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MSG_Write* (&netchan->message, <data>).
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If the message buffer is overflowed, either by a single message, or by
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multiple frames worth piling up while the last reliable transmit goes
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unacknowledged, the netchan signals a fatal error.
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Reliable messages are always placed first in a packet, then the unreliable
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message is included if there is sufficient room.
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To the receiver, there is no distinction between the reliable and unreliable
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parts of the message, they are just processed out as a single larger message.
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Illogical packet sequence numbers cause the packet to be dropped, but do
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not kill the connection. This, combined with the tight window of valid
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reliable acknowledgement numbers provides protection against malicious
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address spoofing.
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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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If there is no information that needs to be transfered on a given frame,
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such as during the connection stage while waiting for the client to load,
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then a packet only needs to be delivered if there is something in the
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unacknowledged reliable
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*/
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* packet header
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* -------------
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* 31 sequence
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* 1 does this message contain a reliable payload
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* 31 acknowledge sequence
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* 1 acknowledge receipt of even/odd message
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* 16 qport
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*
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* The remote connection never knows if it missed a reliable message,
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* the local side detects that it has been dropped by seeing a sequence
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* acknowledge higher thatn the last reliable sequence, but without the
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* correct even/odd bit for the reliable set.
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*
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* If the sender notices that a reliable message has been dropped, it
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* will be retransmitted. It will not be retransmitted again until a
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* message after the retransmit has been acknowledged and the reliable
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* still failed to get there.
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*
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* if the sequence number is -1, the packet should be handled without a
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* netcon
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*
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* The reliable message can be added to at any time by doing MSG_Write*
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* (&netchan->message, <data>).
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*
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* If the message buffer is overflowed, either by a single message, or
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* by multiple frames worth piling up while the last reliable transmit
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* goes unacknowledged, the netchan signals a fatal error.
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*
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* Reliable messages are always placed first in a packet, then the
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* unreliable message is included if there is sufficient room.
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*
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* To the receiver, there is no distinction between the reliable and
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* unreliable parts of the message, they are just processed out as a
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* single larger message.
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*
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* Illogical packet sequence numbers cause the packet to be dropped, but
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* do not kill the connection. This, combined with the tight window of
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* valid reliable acknowledgement numbers provides protection against
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* malicious address spoofing.
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*
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* The qport field is a workaround for bad address translating routers
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* that sometimes remap the client's source port on a packet during
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* gameplay.
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*
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* If the base part of the net address matches and the qport matches,
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* then the channel matches even if the IP port differs. The IP port
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* should be updated to the new value before sending out any replies.
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*
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* If there is no information that needs to be transfered on a given
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* frame, such as during the connection stage while waiting for the
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* client to load, then a packet only needs to be delivered if there is
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* something in the unacknowledged reliable
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*/
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cvar_t *showpackets;
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cvar_t *showdrop;
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@ -82,17 +89,11 @@ netadr_t net_from;
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sizebuf_t net_message;
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byte net_message_buffer[MAX_MSGLEN];
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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 (void)
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{
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int port;
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// pick a port value that should be nice and random
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/* pick a port value that should be nice and random */
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port = Sys_Milliseconds() & 0xffff;
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showpackets = Cvar_Get ("showpackets", "0", 0);
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@ -101,39 +102,31 @@ void Netchan_Init (void)
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}
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/*
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===============
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Netchan_OutOfBand
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Sends an out-of-band datagram
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================
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*/
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* Sends an out-of-band datagram
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*/
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void Netchan_OutOfBand (int net_socket, netadr_t adr, int length, byte *data)
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{
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sizebuf_t send;
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byte send_buf[MAX_MSGLEN];
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// write the packet header
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/* write the packet header */
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SZ_Init (&send, send_buf, sizeof(send_buf));
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MSG_WriteLong (&send, -1); // -1 sequence means out of band
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MSG_WriteLong (&send, -1); /* -1 sequence means out of band */
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SZ_Write (&send, data, length);
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// send the datagram
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/* send the datagram */
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NET_SendPacket (net_socket, send.cursize, send.data, adr);
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}
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/*
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===============
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Netchan_OutOfBandPrint
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Sends a text message in an out-of-band datagram
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================
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*/
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* Sends a text message in an out-of-band datagram
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*/
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void Netchan_OutOfBandPrint (int net_socket, netadr_t adr, char *format, ...)
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{
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va_list argptr;
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static char string[MAX_MSGLEN - 4];
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static char string[MAX_MSGLEN - 4];
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va_start (argptr, format);
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vsnprintf (string, MAX_MSGLEN - 4, format, argptr);
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va_end (argptr);
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@ -141,18 +134,13 @@ void Netchan_OutOfBandPrint (int net_socket, netadr_t adr, char *format, ...)
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Netchan_OutOfBand (net_socket, adr, strlen(string), (byte *)string);
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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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* called to open a channel to a remote system
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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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{
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memset (chan, 0, sizeof(*chan));
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chan->sock = sock;
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chan->remote_address = adr;
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chan->qport = qport;
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@ -164,34 +152,29 @@ void Netchan_Setup (netsrc_t sock, netchan_t *chan, netadr_t adr, int qport)
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chan->message.allowoverflow = true;
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}
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/*
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===============
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Netchan_CanReliable
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Returns true if the last reliable message has acked
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================
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*/
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* Returns true if the last reliable message has acked
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*/
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qboolean Netchan_CanReliable (netchan_t *chan)
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{
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if (chan->reliable_length)
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return false; // waiting for ack
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return false; /* waiting for ack */
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return true;
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}
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qboolean Netchan_NeedReliable (netchan_t *chan)
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{
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qboolean send_reliable;
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// if the remote side dropped the last reliable message, resend it
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/* if the remote side dropped the last reliable message, resend it */
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send_reliable = false;
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if (chan->incoming_acknowledged > chan->last_reliable_sequence
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&& chan->incoming_reliable_acknowledged != chan->reliable_sequence)
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&& chan->incoming_reliable_acknowledged != chan->reliable_sequence)
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send_reliable = true;
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// if the reliable transmit buffer is empty, copy the current message out
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/* if the reliable transmit buffer is empty, copy the current message out */
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if (!chan->reliable_length && chan->message.cursize)
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{
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send_reliable = true;
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@ -201,15 +184,11 @@ qboolean Netchan_NeedReliable (netchan_t *chan)
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}
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/*
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===============
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Netchan_Transmit
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tries to send an unreliable message to a connection, and handles the
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transmition / retransmition of the reliable messages.
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A 0 length will still generate a packet and deal with the reliable messages.
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================
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*/
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* tries to send an unreliable message to a connection, and handles the
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* transmition / retransmition of the reliable messages.
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*
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* A 0 length will still generate a packet and deal with the reliable messages.
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*/
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void Netchan_Transmit (netchan_t *chan, int length, byte *data)
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{
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sizebuf_t send;
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@ -217,12 +196,12 @@ void Netchan_Transmit (netchan_t *chan, int length, byte *data)
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qboolean send_reliable;
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unsigned w1, w2;
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// check for message overflow
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/* check for message overflow */
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if (chan->message.overflowed)
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{
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chan->fatal_error = true;
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Com_Printf ("%s:Outgoing message overflow\n"
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, NET_AdrToString (chan->remote_address));
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, NET_AdrToString (chan->remote_address));
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return;
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}
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@ -236,8 +215,7 @@ void Netchan_Transmit (netchan_t *chan, int length, byte *data)
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chan->reliable_sequence ^= 1;
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}
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// write the packet header
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/* write the packet header */
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SZ_Init (&send, send_buf, sizeof(send_buf));
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w1 = ( chan->outgoing_sequence & ~(1<<31) ) | (send_reliable<<31);
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@ -249,64 +227,60 @@ void Netchan_Transmit (netchan_t *chan, int length, byte *data)
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MSG_WriteLong (&send, w1);
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MSG_WriteLong (&send, w2);
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// send the qport if we are a client
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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->value);
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// copy the reliable message to the packet first
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/* copy the reliable message to the packet first */
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if (send_reliable)
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{
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SZ_Write (&send, chan->reliable_buf, chan->reliable_length);
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chan->last_reliable_sequence = chan->outgoing_sequence;
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}
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// add the unreliable part if space is available
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/* add the unreliable part if space is available */
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if (send.maxsize - send.cursize >= length)
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SZ_Write (&send, data, length);
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else
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Com_Printf ("Netchan_Transmit: dumped unreliable\n");
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// send the datagram
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/* send the datagram */
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NET_SendPacket (chan->sock, send.cursize, send.data, chan->remote_address);
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if (showpackets->value)
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{
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if (send_reliable)
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Com_Printf ("send %4i : s=%i reliable=%i ack=%i rack=%i\n"
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, send.cursize
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, chan->outgoing_sequence - 1
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, chan->reliable_sequence
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, chan->incoming_sequence
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, chan->incoming_reliable_sequence);
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, send.cursize
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, chan->outgoing_sequence - 1
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, chan->reliable_sequence
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, chan->incoming_sequence
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, chan->incoming_reliable_sequence);
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else
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Com_Printf ("send %4i : s=%i ack=%i rack=%i\n"
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, send.cursize
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, chan->outgoing_sequence - 1
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, chan->incoming_sequence
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, chan->incoming_reliable_sequence);
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, send.cursize
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, chan->outgoing_sequence - 1
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, chan->incoming_sequence
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, chan->incoming_reliable_sequence);
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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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called when the current net_message is from remote_address
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modifies net_message so that it points to the packet payload
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=================
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*/
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* called when the current net_message is from remote_address
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* modifies net_message so that it points to the packet payload
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*/
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qboolean Netchan_Process (netchan_t *chan, sizebuf_t *msg)
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{
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unsigned sequence, sequence_ack;
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unsigned reliable_ack, reliable_message;
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int qport;
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// get sequence numbers
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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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// read the qport if we are a server
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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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@ -314,74 +288,66 @@ qboolean Netchan_Process (netchan_t *chan, sizebuf_t *msg)
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reliable_ack = sequence_ack >> 31;
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sequence &= ~(1<<31);
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sequence_ack &= ~(1<<31);
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sequence_ack &= ~(1<<31);
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if (showpackets->value)
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{
|
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if (reliable_message)
|
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Com_Printf ("recv %4i : s=%i reliable=%i ack=%i rack=%i\n"
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, msg->cursize
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, sequence
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, chan->incoming_reliable_sequence ^ 1
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, sequence_ack
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, reliable_ack);
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, msg->cursize
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, sequence
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, chan->incoming_reliable_sequence ^ 1
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, sequence_ack
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, reliable_ack);
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else
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Com_Printf ("recv %4i : s=%i ack=%i rack=%i\n"
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, msg->cursize
|
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, sequence
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, sequence_ack
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, reliable_ack);
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, msg->cursize
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, sequence
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, sequence_ack
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, reliable_ack);
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}
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//
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// discard stale or duplicated packets
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//
|
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/* discard stale or duplicated packets */
|
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if (sequence <= chan->incoming_sequence)
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{
|
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if (showdrop->value)
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Com_Printf ("%s:Out of order packet %i at %i\n"
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, NET_AdrToString (chan->remote_address)
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, sequence
|
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, chan->incoming_sequence);
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, NET_AdrToString (chan->remote_address)
|
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, sequence
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, chan->incoming_sequence);
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return false;
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}
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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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/* dropped packets don't keep the message from being used */
|
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chan->dropped = sequence - (chan->incoming_sequence+1);
|
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|
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if (chan->dropped > 0)
|
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{
|
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if (showdrop->value)
|
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Com_Printf ("%s:Dropped %i packets at %i\n"
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, NET_AdrToString (chan->remote_address)
|
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, chan->dropped
|
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, sequence);
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, NET_AdrToString (chan->remote_address)
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, chan->dropped
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, sequence);
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}
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//
|
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// if the current outgoing reliable message has been acknowledged
|
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// clear the buffer to make way for the next
|
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//
|
||||
/* if the current outgoing reliable message has been acknowledged
|
||||
clear the buffer to make way for the next */
|
||||
if (reliable_ack == chan->reliable_sequence)
|
||||
chan->reliable_length = 0; // it has been received
|
||||
|
||||
//
|
||||
// if this message contains a reliable message, bump incoming_reliable_sequence
|
||||
//
|
||||
chan->reliable_length = 0; /* it has been received */
|
||||
|
||||
/* if this message contains a reliable message, bump incoming_reliable_sequence */
|
||||
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
|
||||
//
|
||||
/* the message can now be read from the current message pointer */
|
||||
chan->last_received = curtime;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue