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freeswitch/libs/openzap/src/isdn/Q921.c

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/*****************************************************************************
FileName: q921.c
Description: Contains the implementation of a Q.921 protocol
Created: 27.dec.2000/JVB
License/Copyright:
Copyright (c) 2007, Jan Vidar Berger, Case Labs, Ltd. All rights reserved.
email:janvb@caselaboratories.com
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
* Neither the name of the Case Labs, Ltd nor the names of its contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*****************************************************************************/
#include "Q921.h"
#include <stdlib.h>
#include <stdio.h>
#include "mfifo.h"
int Q921SendRR(L2TRUNK trunk, int Sapi, int cr, int Tei, int pf);
/*****************************************************************************
Function: Q921_InitTrunk
Decription: Initialize a Q.921 trunk so it is ready for use. This
function MUST be called before you call any other functions.
*****************************************************************************/
void Q921_InitTrunk(L2TRUNK trunk,
L2UCHAR sapi,
L2UCHAR tei,
Q921NetUser_t NetUser,
L2INT hsize,
Q921TxCB_t cb21,
Q921TxCB_t cb23,
void *priv21,
void *priv23)
{
if (trunk->initialized != INITIALIZED_MAGIC) {
MFIFOCreate(trunk->HDLCInQueue, Q921MAXHDLCSPACE, 10);
trunk->initialized = INITIALIZED_MAGIC;
}
trunk->va = 0;
trunk->vs = 0;
trunk->vr = 0;
trunk->state = 0;
trunk->sapi = sapi;
trunk->tei = tei;
trunk->NetUser = NetUser;
trunk->Q921Tx21Proc = cb21;
trunk->Q921Tx23Proc = cb23;
trunk->PrivateData21 = priv21;
trunk->PrivateData23 = priv23;
trunk->Q921HeaderSpace = hsize;
trunk->T200 = 0;
trunk->T203 = 0;
trunk->T200Timeout = 1000;
trunk->T203Timeout = 10000;
}
int Q921Tx21Proc(L2TRUNK trunk, L2UCHAR *Msg, L2INT size)
{
return trunk->Q921Tx21Proc(trunk->PrivateData21, Msg, size);
}
int Q921Tx23Proc(L2TRUNK trunk, L2UCHAR *Msg, L2INT size)
{
return trunk->Q921Tx23Proc(trunk->PrivateData23, Msg, size);
}
/*****************************************************************************
Function: Q921TimeTick
Description: Called periodically from an external source to allow the
stack to process and maintain it's own timers.
Return Value: none
*****************************************************************************/
L2ULONG (*Q921GetTimeProc) (void) = NULL; /* callback for func reading time in ms */
L2ULONG tLast = {0};
L2ULONG Q921GetTime(void)
{
L2ULONG tNow = 0;
if(Q921GetTimeProc != NULL)
{
tNow = Q921GetTimeProc();
if(tNow < tLast) /* wrapped */
{
/* TODO */
}
tLast = tNow;
}
return tNow;
}
void Q921T200TimerStart(L2TRUNK trunk)
{
if (!trunk->T200) {
trunk->T200 = Q921GetTime() + trunk->T200Timeout;
}
}
void Q921T200TimerStop(L2TRUNK trunk)
{
trunk->T200 = 0;
}
void Q921T200TimerReset(L2TRUNK trunk)
{
Q921T200TimerStop(trunk);
Q921T200TimerStart(trunk);
}
void Q921T203TimerStart(L2TRUNK trunk)
{
if (!trunk->T203) {
trunk->T203 = Q921GetTime() + trunk->T203Timeout;
}
}
void Q921T203TimerStop(L2TRUNK trunk)
{
trunk->T203 = 0;
}
void Q921T203TimerReset(L2TRUNK trunk)
{
Q921T203TimerStop(trunk);
Q921T203TimerStart(trunk);
}
void Q921T200TimerExpire(L2TRUNK trunk)
{
(void)trunk;
}
void Q921T203TimerExpire(L2TRUNK trunk)
{
Q921T203TimerReset(trunk);
Q921SendRR(trunk, trunk->sapi, trunk->NetUser == Q921_TE ? 0 : 1, trunk->tei, 1);
}
void Q921TimerTick(L2TRUNK trunk)
{
L2ULONG tNow = Q921GetTime();
if (trunk->T200 && tNow > trunk->T200) {
Q921T200TimerExpire(trunk);
}
if (trunk->T203 && tNow > trunk->T203) {
Q921T203TimerExpire(trunk);
}
}
void Q921SetGetTimeCB(L2ULONG (*callback)(void))
{
Q921GetTimeProc = callback;
}
/*****************************************************************************
Function: Q921QueueHDLCFrame
Description: Called to receive and queue an incoming HDLC frame. Will
queue this in Q921HDLCInQueue. The called must either call
Q921Rx12 directly afterwards or signal Q921Rx12 to be called
later. Q921Rx12 will read from the same queue and process
the frame.
This function assumes that the message contains header
space. This is removed for internal Q921 processing, but
must be keept for I frames.
Parameters: trunk trunk #
b ptr to frame;
size size of frame in bytes
*****************************************************************************/
int Q921QueueHDLCFrame(L2TRUNK trunk, L2UCHAR *b, L2INT size)
{
return MFIFOWriteMes(trunk->HDLCInQueue, b, size);
}
/*****************************************************************************
Function: Q921SendI
Description: Compose and Send I Frame to layer. Will receive an I frame
with space for L2 header and fill out that header before
it call Q921Tx21Proc.
Parameters: trunk trunk #
Sapi Sapi
cr C/R field.
Tei Tei.
pf P fiels octet 5
mes ptr to I frame message.
size size of message in bytes.
Return Value: 0 if failed, 1 if Send.
*****************************************************************************/
int Q921SendI(L2TRUNK trunk, L2UCHAR Sapi, char cr, L2UCHAR Tei, char pf, L2UCHAR *mes, L2INT size)
{
mes[trunk->Q921HeaderSpace+0] = (Sapi&0xfc) | ((cr<<1)&0x02);
mes[trunk->Q921HeaderSpace+1] = (Tei<<1) | 0x01;
mes[trunk->Q921HeaderSpace+2] = trunk->vs<<1;
mes[trunk->Q921HeaderSpace+3] = (trunk->vr<<1) | (pf & 0x01);
trunk->vs++;
return Q921Tx21Proc(trunk, mes, size);
}
int Q921Rx32(L2TRUNK trunk, L2UCHAR * Mes, L2INT Size)
{
return Q921SendI(trunk,
trunk->sapi,
trunk->NetUser == Q921_TE ? 0 : 1,
trunk->tei,
0,
Mes,
Size);
}
/*****************************************************************************
Function: Q921SendRR
Description: Compose and send Receive Ready.
Parameters: trunk trunk #
Sapi Sapi
cr C/R field.
Tei Tei.
pf P/F fiels octet 5
Return Value: 0 if failed, 1 if Send.
*****************************************************************************/
int Q921SendRR(L2TRUNK trunk, int Sapi, int cr, int Tei, int pf)
{
L2UCHAR mes[400];
mes[trunk->Q921HeaderSpace+0] = (L2UCHAR)((Sapi&0xfc) | ((cr<<1)&0x02));
mes[trunk->Q921HeaderSpace+1] = (L2UCHAR)((Tei<<1) | 0x01);
mes[trunk->Q921HeaderSpace+2] = (L2UCHAR)0x01;
mes[trunk->Q921HeaderSpace+3] = (L2UCHAR)((trunk->vr<<1) | (pf & 0x01));
return Q921Tx21Proc(trunk, mes, trunk->Q921HeaderSpace+4);
}
/*****************************************************************************
Function: Q921SendRNR
Description: Compose and send Receive Nor Ready
Parameters: trunk trunk #
Sapi Sapi
cr C/R field.
Tei Tei.
pf P/F fiels octet 5
Return Value: 0 if failed, 1 if Send.
*****************************************************************************/
int Q921SendRNR(L2TRUNK trunk, int Sapi, int cr, int Tei, int pf)
{
L2UCHAR mes[400];
mes[trunk->Q921HeaderSpace+0] = (L2UCHAR)((Sapi&0xfc) | ((cr<<1)&0x02));
mes[trunk->Q921HeaderSpace+1] = (L2UCHAR)((Tei<<1) | 0x01);
mes[trunk->Q921HeaderSpace+2] = (L2UCHAR)0x05;
mes[trunk->Q921HeaderSpace+3] = (L2UCHAR)((trunk->vr<<1) | (pf & 0x01));
return Q921Tx21Proc(trunk, mes, trunk->Q921HeaderSpace+4);
}
/*****************************************************************************
Function: Q921SendREJ
Description: Compose and Send Reject.
Parameters: trunk trunk #
Sapi Sapi
cr C/R field.
Tei Tei.
pf P/F fiels octet 5
Return Value: 0 if failed, 1 if Send.
*****************************************************************************/
int Q921SendREJ(L2TRUNK trunk, int Sapi, int cr, int Tei, int pf)
{
L2UCHAR mes[400];
mes[trunk->Q921HeaderSpace+0] = (L2UCHAR)((Sapi&0xfc) | ((cr<<1)&0x02));
mes[trunk->Q921HeaderSpace+1] = (L2UCHAR)((Tei<<1) | 0x01);
mes[trunk->Q921HeaderSpace+2] = (L2UCHAR)0x09;
mes[trunk->Q921HeaderSpace+3] = (L2UCHAR)((trunk->vr<<1) | (pf & 0x01));
return Q921Tx21Proc(trunk, mes, trunk->Q921HeaderSpace+4);
}
/*****************************************************************************
Function: Q921SendSABME
Description: Compose and send SABME
Parameters: trunk trunk #
Sapi Sapi
cr C/R field.
Tei Tei.
pf P fiels octet 4
Return Value: 0 if failed, 1 if Send.
*****************************************************************************/
int Q921SendSABME(L2TRUNK trunk, int Sapi, int cr, int Tei, int pf)
{
L2UCHAR mes[400];
mes[trunk->Q921HeaderSpace+0] = (L2UCHAR)((Sapi&0xfc) | ((cr<<1)&0x02));
mes[trunk->Q921HeaderSpace+1] = (L2UCHAR)((Tei<<1) | 0x01);
mes[trunk->Q921HeaderSpace+2] = (L2UCHAR)(0x6f | ((pf<<4)&0x10));
return Q921Tx21Proc(trunk, mes, trunk->Q921HeaderSpace+3);
}
int Q921Start(L2TRUNK trunk)
{
return Q921SendSABME(trunk,
trunk->sapi,
trunk->NetUser == Q921_TE ? 0 : 1,
trunk->tei,
1);
}
/*****************************************************************************
Function: Q921SendDM
Description: Comose and Send DM (Disconnected Mode)
Parameters: trunk trunk #
Sapi Sapi
cr C/R field.
Tei Tei.
pf F fiels octet 4
Return Value: 0 if failed, 1 if Send.
*****************************************************************************/
int Q921SendDM(L2TRUNK trunk, int Sapi, int cr, int Tei, int pf)
{
L2UCHAR mes[400];
mes[trunk->Q921HeaderSpace+0] = (L2UCHAR)((Sapi&0xfc) | ((cr<<1)&0x02));
mes[trunk->Q921HeaderSpace+1] = (L2UCHAR)((Tei<<1) | 0x01);
mes[trunk->Q921HeaderSpace+2] = (L2UCHAR)(0x0f | ((pf<<4)&0x10));
return Q921Tx21Proc(trunk, mes, trunk->Q921HeaderSpace+3);
}
/*****************************************************************************
Function: Q921SendDISC
Description: Compose and Send Disconnect
Parameters: trunk trunk #
Sapi Sapi
cr C/R field.
Tei Tei.
pf P fiels octet 4
Return Value: 0 if failed, 1 if Send.
*****************************************************************************/
int Q921SendDISC(L2TRUNK trunk, int Sapi, int cr, int Tei, int pf)
{
L2UCHAR mes[400];
mes[trunk->Q921HeaderSpace+0] = (L2UCHAR)((Sapi&0xfc) | ((cr<<1)&0x02));
mes[trunk->Q921HeaderSpace+1] = (L2UCHAR)((Tei<<1) | 0x01);
mes[trunk->Q921HeaderSpace+2] = (L2UCHAR)(0x43 | ((pf<<4)&0x10));
return Q921Tx21Proc(trunk, mes, trunk->Q921HeaderSpace+3);
}
/*****************************************************************************
Function: Q921SendUA
Description: Compose and Send UA
Parameters: trunk trunk #
Sapi Sapi
cr C/R field.
Tei Tei.
pf F fiels octet 4
Return Value: 0 if failed, 1 if Send.
*****************************************************************************/
int Q921SendUA(L2TRUNK trunk, int Sapi, int cr, int Tei, int pf)
{
L2UCHAR mes[400];
mes[trunk->Q921HeaderSpace+0] = (L2UCHAR)((Sapi&0xfc) | ((cr<<1)&0x02));
mes[trunk->Q921HeaderSpace+1] = (L2UCHAR)((Tei<<1) | 0x01);
mes[trunk->Q921HeaderSpace+2] = (L2UCHAR)(0x63 | ((pf<<4)&0x10));
return Q921Tx21Proc(trunk, mes, trunk->Q921HeaderSpace+3);
}
int Q921ProcSABME(L2TRUNK trunk, L2UCHAR *mes, L2INT size)
{
/* TODO: Do we need these paramaters? */
(void)mes;
(void)size;
trunk->vr=0;
trunk->vs=0;
trunk->va=0;
return 1;
}
/*****************************************************************************
Function: Q921Rx12
Description: Called to process a message frame from layer 1. Will
identify the message and call the proper 'processor' for
layer 2 messages and forward I frames to the layer 3 entity.
Q921Rx12 will check the input fifo for a message, and if a
message exist process one message before it exits. The caller
must either call Q921Rx12 polling or keep track on #
messages in the queue.
Parameters: trunk trunk #.
Return Value: # messages processed (always 1 or 0).
*****************************************************************************/
int Q921Rx12(L2TRUNK trunk)
{
L2UCHAR *mes;
L2INT rs,size; /* receive size & Q921 frame size*/
L2UCHAR *smes = MFIFOGetMesPtr(trunk->HDLCInQueue, &size);
L2UCHAR nr;
if(smes != NULL)
{
rs = size - trunk->Q921HeaderSpace;
mes = &smes[trunk->Q921HeaderSpace];
if ((mes[2] & 3) != 3) {
/* we have an S or I frame */
/* if nr is between va and vs, update our va counter */
nr = (mes[3] >> 1);
if (nr >= trunk->va && nr <= trunk->vs) {
trunk->va = nr;
}
}
/* check for I frame */
if((mes[2] & 0x01) == 0)
{
/* we increment before we "really" know its good so that if we send in the callback, we use the right nr */
trunk->vr++;
if(Q921Tx23Proc(trunk, smes, size-2)) /* -2 to clip away CRC */
{
Q921SendRR(trunk, (mes[0]&0xfc)>>2, (mes[0]>>1)&0x01, mes[1]>>1, mes[3]&0x01);
}
else
{
/* todo: whatever*/
/* trunk->vr--; */
/* for now, lets just respond for easier debugging on errors */
Q921SendRR(trunk, (mes[0]&0xfc)>>2, (mes[0]>>1)&0x01, mes[1]>>1, mes[3]&0x01);
}
}
/* check for RR */
else if(mes[2] ==0x01)
{
if (((mes[0]>>1)&0x01) == (trunk->NetUser == Q921_TE ? 1 : 0)) { /* if this is a command */
Q921SendRR(trunk, (mes[0]&0xfc)>>2, (mes[0]>>1)&0x01, mes[1]>>1, mes[2]&0x01);
}
}
/* check for RNR */
/* check for REJ */
/* check for SABME */
else if((mes[2] & 0xef) == 0x6f)
{
Q921ProcSABME(trunk, mes, rs);
Q921SendUA(trunk, (mes[0]&0xfc)>>2, (mes[0]>>1)&0x01,mes[1]>>1, (mes[2]&0x10)>>4);
}
/* check for DM */
/* check for UI */
/* check for DISC */
/* check for UA */
/* check for FRMR */
/* check for XID */
else
{
/* what the ? Issue an error */
/* Q921ErrorProc(trunk, Q921_UNKNOWNFRAME, mes, rs); */
/* todo: REJ or FRMR */
}
MFIFOKillNext(trunk->HDLCInQueue);
return 1;
}
return 0;
}
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