73 lines
2.4 KiB
C
73 lines
2.4 KiB
C
|
/*
|
|||
|
|
* isdnhdlc.h -- General purpose ISDN HDLC decoder.
|
|||
|
|
*
|
|||
|
|
* Implementation of a HDLC decoder/encoder in software.
|
|||
|
|
* Neccessary because some ISDN devices don't have HDLC
|
|||
|
|
* controllers. Also included: a bit reversal table.
|
|||
|
|
*
|
|||
|
|
*Copyright (C) 2002 Wolfgang M<EFBFBD>es <wolfgang@iksw-muees.de>
|
|||
|
|
* 2001 Frode Isaksen <fisaksen@bewan.com>
|
|||
|
|
* 2001 Kai Germaschewski <kai.germaschewski@gmx.de>
|
|||
|
|
*
|
|||
|
|
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
#ifndef __ISDNHDLC_H__
|
|||
|
|
#define __ISDNHDLC_H__
|
|||
|
|
|
|||
|
|
struct isdnhdlc_vars {
|
|||
|
|
int bit_shift;
|
|||
|
|
int hdlc_bits1;
|
|||
|
|
int data_bits;
|
|||
|
|
int ffbit_shift; // encoding only
|
|||
|
|
int state;
|
|||
|
|
int dstpos;
|
|||
|
|
|
|||
|
|
unsigned short crc;
|
|||
|
|
|
|||
|
|
unsigned char cbin;
|
|||
|
|
unsigned char shift_reg;
|
|||
|
|
unsigned char ffvalue;
|
|||
|
|
|
|||
|
|
int data_received:1; // set if transferring data
|
|||
|
|
int dchannel:1; // set if D channel (send idle instead of flags)
|
|||
|
|
int do_adapt56:1; // set if 56K adaptation
|
|||
|
|
int do_closing:1; // set if in closing phase (need to send CRC + flag
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
The return value from isdnhdlc_decode is
|
|||
|
|
the frame length, 0 if no complete frame was decoded,
|
|||
|
|
or a negative error number
|
|||
|
|
*/
|
|||
|
|
#define HDLC_FRAMING_ERROR 1
|
|||
|
|
#define HDLC_CRC_ERROR 2
|
|||
|
|
#define HDLC_LENGTH_ERROR 3
|
|||
|
|
|
|||
|
|
extern const unsigned char isdnhdlc_bit_rev_tab[256];
|
|||
|
|
|
|||
|
|
extern void isdnhdlc_rcv_init (struct isdnhdlc_vars *hdlc, int do_adapt56);
|
|||
|
|
|
|||
|
|
extern int isdnhdlc_decode (struct isdnhdlc_vars *hdlc, const unsigned char *src, int slen,int *count,
|
|||
|
|
unsigned char *dst, int dsize);
|
|||
|
|
|
|||
|
|
extern void isdnhdlc_out_init (struct isdnhdlc_vars *hdlc,int is_d_channel,int do_adapt56);
|
|||
|
|
|
|||
|
|
extern int isdnhdlc_encode (struct isdnhdlc_vars *hdlc,const unsigned char *src,unsigned short slen,int *count,
|
|||
|
|
unsigned char *dst,int dsize);
|
|||
|
|
|
|||
|
|
#endif /* __ISDNHDLC_H__ */
|