mirror of https://gerrit.osmocom.org/libosmocore
isdnhdlc: Port from kernel to userspace
* prefix all symbols/constants with osmo_ * use stdint.h types instead of kernel types * use Doxygen API documentation * use Osmocom CRC16-CCITT functions * use Osmocom bit-reversal functions * integrate with Automake Change-Id: I109085ab3e412c20b19cd42fb7137aa0e4167542changes/15/8115/1
parent
85b9fbae7e
commit
9da77abb6b
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@ -26,6 +26,7 @@ nobase_include_HEADERS = \
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osmocom/core/fsm.h \
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osmocom/core/gsmtap.h \
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osmocom/core/gsmtap_util.h \
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osmocom/core/isdnhdlc.h \
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osmocom/core/linuxlist.h \
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osmocom/core/linuxrbtree.h \
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osmocom/core/logging.h \
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@ -1,5 +1,5 @@
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/*
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* hdlc.h -- General purpose ISDN HDLC decoder.
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* isdnhdlc.h -- General purpose ISDN HDLC decoder.
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*
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* Implementation of a HDLC decoder/encoder in software.
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* Necessary because some ISDN devices don't have HDLC
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@ -29,7 +29,9 @@
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#ifndef __ISDNHDLC_H__
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#define __ISDNHDLC_H__
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struct isdnhdlc_vars {
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#include <stdint.h>
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struct osmo_isdnhdlc_vars {
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int bit_shift;
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int hdlc_bits1;
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int data_bits;
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@ -37,46 +39,46 @@ struct isdnhdlc_vars {
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int state;
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int dstpos;
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u16 crc;
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uint16_t crc;
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u8 cbin;
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u8 shift_reg;
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u8 ffvalue;
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uint8_t cbin;
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uint8_t shift_reg;
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uint8_t ffvalue;
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/* set if transferring data */
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u32 data_received:1;
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uint32_t data_received:1;
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/* set if D channel (send idle instead of flags) */
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u32 dchannel:1;
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uint32_t dchannel:1;
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/* set if 56K adaptation */
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u32 do_adapt56:1;
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uint32_t do_adapt56:1;
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/* set if in closing phase (need to send CRC + flag) */
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u32 do_closing:1;
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uint32_t do_closing:1;
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/* set if data is bitreverse */
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u32 do_bitreverse:1;
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uint32_t do_bitreverse:1;
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};
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/* Feature Flags */
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#define HDLC_56KBIT 0x01
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#define HDLC_DCHANNEL 0x02
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#define HDLC_BITREVERSE 0x04
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#define OSMO_HDLC_F_56KBIT 0x01
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#define OSMO_HDLC_F_DCHANNEL 0x02
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#define OSMO_HDLC_F_BITREVERSE 0x04
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/*
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The return value from isdnhdlc_decode is
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the frame length, 0 if no complete frame was decoded,
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or a negative error number
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*/
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#define HDLC_FRAMING_ERROR 1
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#define HDLC_CRC_ERROR 2
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#define HDLC_LENGTH_ERROR 3
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#define OSMO_HDLC_FRAMING_ERROR 1
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#define OSMO_HDLC_CRC_ERROR 2
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#define OSMO_HDLC_LENGTH_ERROR 3
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extern void isdnhdlc_rcv_init(struct isdnhdlc_vars *hdlc, u32 features);
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extern void osmo_isdnhdlc_rcv_init(struct osmo_isdnhdlc_vars *hdlc, uint32_t features);
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extern int isdnhdlc_decode(struct isdnhdlc_vars *hdlc, const u8 *src,
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int slen, int *count, u8 *dst, int dsize);
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extern int osmo_isdnhdlc_decode(struct osmo_isdnhdlc_vars *hdlc, const uint8_t *src,
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int slen, int *count, uint8_t *dst, int dsize);
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extern void isdnhdlc_out_init(struct isdnhdlc_vars *hdlc, u32 features);
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extern void osmo_isdnhdlc_out_init(struct osmo_isdnhdlc_vars *hdlc, uint32_t features);
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extern int isdnhdlc_encode(struct isdnhdlc_vars *hdlc, const u8 *src,
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u16 slen, int *count, u8 *dst, int dsize);
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extern int osmo_isdnhdlc_encode(struct osmo_isdnhdlc_vars *hdlc, const uint8_t *src,
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uint16_t slen, int *count, uint8_t *dst, int dsize);
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#endif /* __ISDNHDLC_H__ */
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@ -22,7 +22,8 @@ libosmocore_la_SOURCES = timer.c timer_gettimeofday.c timer_clockgettime.c \
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conv.c application.c rbtree.c strrb.c \
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loggingrb.c crc8gen.c crc16gen.c crc32gen.c crc64gen.c \
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macaddr.c stat_item.c stats.c stats_statsd.c prim.c \
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conv_acc.c conv_acc_generic.c sercomm.c prbs.c
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conv_acc.c conv_acc_generic.c sercomm.c prbs.c \
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isdnhdlc.c
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if HAVE_SSSE3
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libosmocore_la_SOURCES += conv_acc_sse.c
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107
src/isdnhdlc.c
107
src/isdnhdlc.c
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@ -7,6 +7,8 @@
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* 2001 Frode Isaksen <fisaksen@bewan.com>
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* 2001 Kai Germaschewski <kai.germaschewski@gmx.de>
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*
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* slightly adapted for use in userspace / osmocom envrionment by Harald Welte
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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@ -22,21 +24,11 @@
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/crc-ccitt.h>
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#include <linux/isdn/hdlc.h>
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#include <linux/bitrev.h>
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#include <string.h>
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/*-------------------------------------------------------------------*/
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MODULE_AUTHOR("Wolfgang Mües <wolfgang@iksw-muees.de>, "
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"Frode Isaksen <fisaksen@bewan.com>, "
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"Kai Germaschewski <kai.germaschewski@gmx.de>");
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MODULE_DESCRIPTION("General purpose ISDN HDLC decoder");
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MODULE_LICENSE("GPL");
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/*-------------------------------------------------------------------*/
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#include <osmocom/core/crc16.h>
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#include <osmocom/core/bits.h>
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#include <osmocom/core/isdnhdlc.h>
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enum {
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HDLC_FAST_IDLE, HDLC_GET_FLAG_B0, HDLC_GETFLAG_B1A6, HDLC_GETFLAG_B7,
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@ -50,21 +42,22 @@ enum {
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HDLC_SENDFLAG_B1A6, HDLC_SENDFLAG_B7, STOPPED, HDLC_SENDFLAG_ONE
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};
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void isdnhdlc_rcv_init(struct isdnhdlc_vars *hdlc, u32 features)
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#define crc_ccitt_byte osmo_crc16_ccitt_byte
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void osmo_isdnhdlc_rcv_init(struct osmo_isdnhdlc_vars *hdlc, uint32_t features)
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{
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memset(hdlc, 0, sizeof(struct isdnhdlc_vars));
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memset(hdlc, 0, sizeof(*hdlc));
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hdlc->state = HDLC_GET_DATA;
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if (features & HDLC_56KBIT)
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if (features & OSMO_HDLC_F_56KBIT)
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hdlc->do_adapt56 = 1;
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if (features & HDLC_BITREVERSE)
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if (features & OSMO_HDLC_F_BITREVERSE)
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hdlc->do_bitreverse = 1;
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}
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EXPORT_SYMBOL(isdnhdlc_out_init);
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void isdnhdlc_out_init(struct isdnhdlc_vars *hdlc, u32 features)
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void osmo_isdnhdlc_out_init(struct osmo_isdnhdlc_vars *hdlc, uint32_t features)
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{
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memset(hdlc, 0, sizeof(struct isdnhdlc_vars));
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if (features & HDLC_DCHANNEL) {
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memset(hdlc, 0, sizeof(*hdlc));
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if (features & OSMO_HDLC_F_DCHANNEL) {
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hdlc->dchannel = 1;
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hdlc->state = HDLC_SEND_FIRST_FLAG;
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} else {
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@ -73,25 +66,24 @@ void isdnhdlc_out_init(struct isdnhdlc_vars *hdlc, u32 features)
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hdlc->ffvalue = 0x7e;
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}
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hdlc->cbin = 0x7e;
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if (features & HDLC_56KBIT) {
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if (features & OSMO_HDLC_F_56KBIT) {
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hdlc->do_adapt56 = 1;
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hdlc->state = HDLC_SENDFLAG_B0;
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} else
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hdlc->data_bits = 8;
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if (features & HDLC_BITREVERSE)
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if (features & OSMO_HDLC_F_BITREVERSE)
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hdlc->do_bitreverse = 1;
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}
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EXPORT_SYMBOL(isdnhdlc_rcv_init);
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static int
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check_frame(struct isdnhdlc_vars *hdlc)
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check_frame(struct osmo_isdnhdlc_vars *hdlc)
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{
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int status;
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if (hdlc->dstpos < 2) /* too small - framing error */
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status = -HDLC_FRAMING_ERROR;
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status = -OSMO_HDLC_FRAMING_ERROR;
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else if (hdlc->crc != 0xf0b8) /* crc error */
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status = -HDLC_CRC_ERROR;
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status = -OSMO_HDLC_CRC_ERROR;
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else {
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/* remove CRC */
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hdlc->dstpos -= 2;
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@ -101,8 +93,7 @@ check_frame(struct isdnhdlc_vars *hdlc)
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return status;
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}
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/*
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isdnhdlc_decode - decodes HDLC frames from a transparent bit stream.
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/*! decodes HDLC frames from a transparent bit stream.
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The source buffer is scanned for valid HDLC frames looking for
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flags (01111110) to indicate the start of a frame. If the start of
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@ -114,22 +105,21 @@ check_frame(struct isdnhdlc_vars *hdlc)
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If the beginning of a valid frame is found, the function returns
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the length.
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If a framing error is found (too many 1s and not a flag) the function
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returns the length with the bit HDLC_FRAMING_ERROR set.
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returns the length with the bit OSMO_HDLC_FRAMING_ERROR set.
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If a CRC error is found the function returns the length with the
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bit HDLC_CRC_ERROR set.
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bit OSMO_HDLC_CRC_ERROR set.
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If the frame length exceeds the destination buffer size, the function
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returns the length with the bit HDLC_LENGTH_ERROR set.
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returns the length with the bit OSMO_HDLC_LENGTH_ERROR set.
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src - source buffer
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slen - source buffer length
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count - number of bytes removed (decoded) from the source buffer
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dst _ destination buffer
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dsize - destination buffer size
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returns - number of decoded bytes in the destination buffer and status
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flag.
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\param[in] src source buffer
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\param[in] slen source buffer length
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\param[out] count number of bytes removed (decoded) from the source buffer
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\param[out] dst destination buffer
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\param[in] dsize destination buffer size
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\returns number of decoded bytes in the destination buffer and status flag.
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*/
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int isdnhdlc_decode(struct isdnhdlc_vars *hdlc, const u8 *src, int slen,
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int *count, u8 *dst, int dsize)
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int osmo_isdnhdlc_decode(struct osmo_isdnhdlc_vars *hdlc, const uint8_t *src, int slen,
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int *count, uint8_t *dst, int dsize)
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{
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int status = 0;
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@ -175,7 +165,7 @@ int isdnhdlc_decode(struct isdnhdlc_vars *hdlc, const u8 *src, int slen,
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if (hdlc->bit_shift == 0) {
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/* the code is for bitreverse streams */
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if (hdlc->do_bitreverse == 0)
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hdlc->cbin = bitrev8(*src++);
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hdlc->cbin = osmo_revbytebits_8(*src++);
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else
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hdlc->cbin = *src++;
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slen--;
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@ -242,7 +232,7 @@ int isdnhdlc_decode(struct isdnhdlc_vars *hdlc, const u8 *src, int slen,
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case 7:
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if (hdlc->data_received)
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/* bad frame */
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status = -HDLC_FRAMING_ERROR;
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status = -OSMO_HDLC_FRAMING_ERROR;
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if (!hdlc->do_adapt56) {
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if (hdlc->cbin == fast_abort
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[hdlc->bit_shift + 1]) {
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@ -302,7 +292,7 @@ int isdnhdlc_decode(struct isdnhdlc_vars *hdlc, const u8 *src, int slen,
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dst[hdlc->dstpos++] = hdlc->shift_reg;
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else {
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/* frame too long */
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status = -HDLC_LENGTH_ERROR;
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status = -OSMO_HDLC_LENGTH_ERROR;
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hdlc->dstpos = 0;
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}
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}
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@ -331,9 +321,7 @@ int isdnhdlc_decode(struct isdnhdlc_vars *hdlc, const u8 *src, int slen,
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*count -= slen;
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return 0;
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}
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EXPORT_SYMBOL(isdnhdlc_decode);
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/*
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isdnhdlc_encode - encodes HDLC frames to a transparent bit stream.
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/*! encodes HDLC frames to a transparent bit stream.
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The bit stream starts with a beginning flag (01111110). After
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that each byte is added to the bit stream with bit stuffing added
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@ -344,15 +332,15 @@ EXPORT_SYMBOL(isdnhdlc_decode);
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If this function is called with empty source buffer (slen=0), flags or
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idle character will be generated.
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src - source buffer
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slen - source buffer length
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count - number of bytes removed (encoded) from source buffer
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dst _ destination buffer
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dsize - destination buffer size
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returns - number of encoded bytes in the destination buffer
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\param[in] src source buffer
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\param[in] slen source buffer length
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\param[out] count number of bytes removed (encoded) from source buffer
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\param[out] dst destination buffer
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\param[in] dsize destination buffer size
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\returns - number of encoded bytes in the destination buffer
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*/
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int isdnhdlc_encode(struct isdnhdlc_vars *hdlc, const u8 *src, u16 slen,
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int *count, u8 *dst, int dsize)
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int osmo_isdnhdlc_encode(struct osmo_isdnhdlc_vars *hdlc, const uint8_t *src, uint16_t slen,
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int *count, uint8_t *dst, int dsize)
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{
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static const unsigned char xfast_flag_value[] = {
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0x7e, 0x3f, 0x9f, 0xcf, 0xe7, 0xf3, 0xf9, 0xfc, 0x7e
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@ -403,7 +391,7 @@ int isdnhdlc_encode(struct isdnhdlc_vars *hdlc, const u8 *src, u16 slen,
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if (slen == 0) {
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/* the code is for bitreverse streams */
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if (hdlc->do_bitreverse == 0)
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*dst++ = bitrev8(hdlc->ffvalue);
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*dst++ = osmo_revbytebits_8(hdlc->ffvalue);
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else
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*dst++ = hdlc->ffvalue;
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len++;
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@ -593,7 +581,7 @@ int isdnhdlc_encode(struct isdnhdlc_vars *hdlc, const u8 *src, u16 slen,
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} else {
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/* the code is for bitreverse streams */
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if (hdlc->do_bitreverse == 0)
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*dst++ = bitrev8(hdlc->cbin);
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*dst++ = osmo_revbytebits_8(hdlc->cbin);
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else
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*dst++ = hdlc->cbin;
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hdlc->bit_shift = 0;
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@ -615,7 +603,7 @@ int isdnhdlc_encode(struct isdnhdlc_vars *hdlc, const u8 *src, u16 slen,
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if (hdlc->data_bits == 8) {
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/* the code is for bitreverse streams */
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if (hdlc->do_bitreverse == 0)
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*dst++ = bitrev8(hdlc->cbin);
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*dst++ = osmo_revbytebits_8(hdlc->cbin);
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else
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*dst++ = hdlc->cbin;
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hdlc->data_bits = 0;
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@ -627,4 +615,3 @@ int isdnhdlc_encode(struct isdnhdlc_vars *hdlc, const u8 *src, u16 slen,
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return len;
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}
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EXPORT_SYMBOL(isdnhdlc_encode);
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