83 lines
2.3 KiB
C
83 lines
2.3 KiB
C
/*
|
|
* hdlc.h -- General purpose ISDN HDLC decoder.
|
|
*
|
|
* Implementation of a HDLC decoder/encoder in software.
|
|
* Neccessary because some ISDN devices don't have HDLC
|
|
* controllers.
|
|
*
|
|
* Copyright (C)
|
|
* 2009 Karsten Keil <keil@b1-systems.de>
|
|
* 2002 Wolfgang Mües <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;
|
|
|
|
u16 crc;
|
|
|
|
u8 cbin;
|
|
u8 shift_reg;
|
|
u8 ffvalue;
|
|
|
|
/* set if transferring data */
|
|
u32 data_received:1;
|
|
/* set if D channel (send idle instead of flags) */
|
|
u32 dchannel:1;
|
|
/* set if 56K adaptation */
|
|
u32 do_adapt56:1;
|
|
/* set if in closing phase (need to send CRC + flag) */
|
|
u32 do_closing:1;
|
|
/* set if data is bitreverse */
|
|
u32 do_bitreverse:1;
|
|
};
|
|
|
|
/* Feature Flags */
|
|
#define HDLC_56KBIT 0x01
|
|
#define HDLC_DCHANNEL 0x02
|
|
#define HDLC_BITREVERSE 0x04
|
|
|
|
/*
|
|
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 void isdnhdlc_rcv_init(struct isdnhdlc_vars *hdlc, u32 features);
|
|
|
|
extern int isdnhdlc_decode(struct isdnhdlc_vars *hdlc, const u8 *src,
|
|
int slen, int *count, u8 *dst, int dsize);
|
|
|
|
extern void isdnhdlc_out_init(struct isdnhdlc_vars *hdlc, u32 features);
|
|
|
|
extern int isdnhdlc_encode(struct isdnhdlc_vars *hdlc, const u8 *src,
|
|
u16 slen, int *count, u8 *dst, int dsize);
|
|
|
|
#endif /* __ISDNHDLC_H__ */
|