1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
|
/*
* 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.
*
* 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__
#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__ */
|
