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isdnhdlc.h
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/*
* isdnhdlc.h -- General purpose ISDN HDLC decoder.
*
* Implementation of a HDLC decoder/encoder in software.
* Necessary 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.
*/
#ifndef __ISDNHDLC_H__
#define __ISDNHDLC_H__
#include <stdint.h>
struct osmo_isdnhdlc_vars {
int bit_shift;
int hdlc_bits1;
int data_bits;
int ffbit_shift; /* encoding only */
int state;
int dstpos;
uint16_t crc;
uint8_t cbin;
uint8_t shift_reg;
uint8_t ffvalue;
/* set if transferring data */
uint32_t data_received:1;
/* set if D channel (send idle instead of flags) */
uint32_t dchannel:1;
/* set if 56K adaptation */
uint32_t do_adapt56:1;
/* set if in closing phase (need to send CRC + flag) */
uint32_t do_closing:1;
/* set if data is bitreverse */
uint32_t do_bitreverse:1;
};
/* Feature Flags */
#define OSMO_HDLC_F_56KBIT 0x01
#define OSMO_HDLC_F_DCHANNEL 0x02
#define OSMO_HDLC_F_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 OSMO_HDLC_FRAMING_ERROR 1
#define OSMO_HDLC_CRC_ERROR 2
#define OSMO_HDLC_LENGTH_ERROR 3
extern void osmo_isdnhdlc_rcv_init(struct osmo_isdnhdlc_vars *hdlc, uint32_t features);
extern int osmo_isdnhdlc_decode(struct osmo_isdnhdlc_vars *hdlc, const uint8_t *src,
int slen, int *count, uint8_t *dst, int dsize);
extern void osmo_isdnhdlc_out_init(struct osmo_isdnhdlc_vars *hdlc, uint32_t features);
extern int osmo_isdnhdlc_encode(struct osmo_isdnhdlc_vars *hdlc, const uint8_t *src,
uint16_t slen, int *count, uint8_t *dst, int dsize);
#endif /* __ISDNHDLC_H__ */
osmo_isdnhdlc_encode
int osmo_isdnhdlc_encode(struct osmo_isdnhdlc_vars *hdlc, const uint8_t *src, uint16_t slen, int *count, uint8_t *dst, int dsize)
encodes HDLC frames to a transparent bit stream.
Definition isdnhdlc.c:338
osmo_isdnhdlc_decode
int osmo_isdnhdlc_decode(struct osmo_isdnhdlc_vars *hdlc, const uint8_t *src, int slen, int *count, uint8_t *dst, int dsize)
decodes HDLC frames from a transparent bit stream.
Definition isdnhdlc.c:117
osmo_isdnhdlc_rcv_init
void osmo_isdnhdlc_rcv_init(struct osmo_isdnhdlc_vars *hdlc, uint32_t features)
Definition isdnhdlc.c:43
osmo_isdnhdlc_out_init
void osmo_isdnhdlc_out_init(struct osmo_isdnhdlc_vars *hdlc, uint32_t features)
Definition isdnhdlc.c:53
osmo_isdnhdlc_vars
Definition isdnhdlc.h:30
osmo_isdnhdlc_vars::do_adapt56
uint32_t do_adapt56
Definition isdnhdlc.h:49
osmo_isdnhdlc_vars::crc
uint16_t crc
Definition isdnhdlc.h:38
osmo_isdnhdlc_vars::hdlc_bits1
int hdlc_bits1
Definition isdnhdlc.h:32
osmo_isdnhdlc_vars::dstpos
int dstpos
Definition isdnhdlc.h:36
osmo_isdnhdlc_vars::ffbit_shift
int ffbit_shift
Definition isdnhdlc.h:34
osmo_isdnhdlc_vars::data_received
uint32_t data_received
Definition isdnhdlc.h:45
osmo_isdnhdlc_vars::do_closing
uint32_t do_closing
Definition isdnhdlc.h:51
osmo_isdnhdlc_vars::cbin
uint8_t cbin
Definition isdnhdlc.h:40
osmo_isdnhdlc_vars::ffvalue
uint8_t ffvalue
Definition isdnhdlc.h:42
osmo_isdnhdlc_vars::shift_reg
uint8_t shift_reg
Definition isdnhdlc.h:41
osmo_isdnhdlc_vars::bit_shift
int bit_shift
Definition isdnhdlc.h:31
osmo_isdnhdlc_vars::dchannel
uint32_t dchannel
Definition isdnhdlc.h:47
osmo_isdnhdlc_vars::do_bitreverse
uint32_t do_bitreverse
Definition isdnhdlc.h:53
osmo_isdnhdlc_vars::state
int state
Definition isdnhdlc.h:35
osmo_isdnhdlc_vars::data_bits
int data_bits
Definition isdnhdlc.h:33