1/* 2 * isdnhdlc.h -- General purpose ISDN HDLC decoder. 3 * 4 * Implementation of a HDLC decoder/encoder in software. 5 * Neccessary because some ISDN devices don't have HDLC 6 * controllers. Also included: a bit reversal table. 7 * 8 *Copyright (C) 2002 Wolfgang M�es <wolfgang@iksw-muees.de> 9 * 2001 Frode Isaksen <fisaksen@bewan.com> 10 * 2001 Kai Germaschewski <kai.germaschewski@gmx.de> 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License as published by 14 * the Free Software Foundation; either version 2 of the License, or 15 * (at your option) any later version. 16 * 17 * This program is distributed in the hope that it will be useful, 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20 * GNU General Public License for more details. 21 * 22 * You should have received a copy of the GNU General Public License 23 * along with this program; if not, write to the Free Software 24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 25 */ 26 27#ifndef __ISDNHDLC_H__ 28#define __ISDNHDLC_H__ 29 30struct isdnhdlc_vars { 31 int bit_shift; 32 int hdlc_bits1; 33 int data_bits; 34 int ffbit_shift; // encoding only 35 int state; 36 int dstpos; 37 38 unsigned short crc; 39 40 unsigned char cbin; 41 unsigned char shift_reg; 42 unsigned char ffvalue; 43 44 unsigned int data_received:1; // set if transferring data 45 unsigned int dchannel:1; // set if D channel (send idle instead of flags) 46 unsigned int do_adapt56:1; // set if 56K adaptation 47 unsigned int do_closing:1; // set if in closing phase (need to send CRC + flag 48}; 49 50 51/* 52 The return value from isdnhdlc_decode is 53 the frame length, 0 if no complete frame was decoded, 54 or a negative error number 55*/ 56#define HDLC_FRAMING_ERROR 1 57#define HDLC_CRC_ERROR 2 58#define HDLC_LENGTH_ERROR 3 59 60extern void isdnhdlc_rcv_init (struct isdnhdlc_vars *hdlc, int do_adapt56); 61 62extern int isdnhdlc_decode (struct isdnhdlc_vars *hdlc, const unsigned char *src, int slen,int *count, 63 unsigned char *dst, int dsize); 64 65extern void isdnhdlc_out_init (struct isdnhdlc_vars *hdlc,int is_d_channel,int do_adapt56); 66 67extern int isdnhdlc_encode (struct isdnhdlc_vars *hdlc,const unsigned char *src,unsigned short slen,int *count, 68 unsigned char *dst,int dsize); 69 70#endif /* __ISDNHDLC_H__ */ 71