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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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629 lines
16 KiB
C
629 lines
16 KiB
C
![]() |
/*
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* isdnhdlc.c -- General purpose ISDN HDLC decoder.
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*
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*Copyright (C) 2002 Wolfgang M<EFBFBD>es <wolfgang@iksw-muees.de>
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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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* 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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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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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 "isdnhdlc.h"
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/*-------------------------------------------------------------------*/
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MODULE_AUTHOR("Wolfgang M<>es <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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/* bit swap table.
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* Very handy for devices with different bit order,
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* and neccessary for each transparent B-channel access for all
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* devices which works with this HDLC decoder without bit reversal.
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*/
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const unsigned char isdnhdlc_bit_rev_tab[256] = {
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0x00,0x80,0x40,0xC0,0x20,0xA0,0x60,0xE0,0x10,0x90,0x50,0xD0,0x30,0xB0,0x70,0xF0,
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0x08,0x88,0x48,0xC8,0x28,0xA8,0x68,0xE8,0x18,0x98,0x58,0xD8,0x38,0xB8,0x78,0xF8,
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0x04,0x84,0x44,0xC4,0x24,0xA4,0x64,0xE4,0x14,0x94,0x54,0xD4,0x34,0xB4,0x74,0xF4,
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0x0C,0x8C,0x4C,0xCC,0x2C,0xAC,0x6C,0xEC,0x1C,0x9C,0x5C,0xDC,0x3C,0xBC,0x7C,0xFC,
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0x02,0x82,0x42,0xC2,0x22,0xA2,0x62,0xE2,0x12,0x92,0x52,0xD2,0x32,0xB2,0x72,0xF2,
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0x0A,0x8A,0x4A,0xCA,0x2A,0xAA,0x6A,0xEA,0x1A,0x9A,0x5A,0xDA,0x3A,0xBA,0x7A,0xFA,
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0x06,0x86,0x46,0xC6,0x26,0xA6,0x66,0xE6,0x16,0x96,0x56,0xD6,0x36,0xB6,0x76,0xF6,
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0x0E,0x8E,0x4E,0xCE,0x2E,0xAE,0x6E,0xEE,0x1E,0x9E,0x5E,0xDE,0x3E,0xBE,0x7E,0xFE,
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0x01,0x81,0x41,0xC1,0x21,0xA1,0x61,0xE1,0x11,0x91,0x51,0xD1,0x31,0xB1,0x71,0xF1,
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0x09,0x89,0x49,0xC9,0x29,0xA9,0x69,0xE9,0x19,0x99,0x59,0xD9,0x39,0xB9,0x79,0xF9,
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0x05,0x85,0x45,0xC5,0x25,0xA5,0x65,0xE5,0x15,0x95,0x55,0xD5,0x35,0xB5,0x75,0xF5,
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0x0D,0x8D,0x4D,0xCD,0x2D,0xAD,0x6D,0xED,0x1D,0x9D,0x5D,0xDD,0x3D,0xBD,0x7D,0xFD,
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0x03,0x83,0x43,0xC3,0x23,0xA3,0x63,0xE3,0x13,0x93,0x53,0xD3,0x33,0xB3,0x73,0xF3,
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0x0B,0x8B,0x4B,0xCB,0x2B,0xAB,0x6B,0xEB,0x1B,0x9B,0x5B,0xDB,0x3B,0xBB,0x7B,0xFB,
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0x07,0x87,0x47,0xC7,0x27,0xA7,0x67,0xE7,0x17,0x97,0x57,0xD7,0x37,0xB7,0x77,0xF7,
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0x0F,0x8F,0x4F,0xCF,0x2F,0xAF,0x6F,0xEF,0x1F,0x9F,0x5F,0xDF,0x3F,0xBF,0x7F,0xFF
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};
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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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HDLC_GET_DATA,HDLC_FAST_FLAG
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};
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enum {
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HDLC_SEND_DATA,HDLC_SEND_CRC1,HDLC_SEND_FAST_FLAG,
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HDLC_SEND_FIRST_FLAG,HDLC_SEND_CRC2,HDLC_SEND_CLOSING_FLAG,
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HDLC_SEND_IDLE1,HDLC_SEND_FAST_IDLE,HDLC_SENDFLAG_B0,
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HDLC_SENDFLAG_B1A6,HDLC_SENDFLAG_B7,STOPPED
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};
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void isdnhdlc_rcv_init (struct isdnhdlc_vars *hdlc, int do_adapt56)
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{
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hdlc->bit_shift = 0;
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hdlc->hdlc_bits1 = 0;
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hdlc->data_bits = 0;
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hdlc->ffbit_shift = 0;
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hdlc->data_received = 0;
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hdlc->state = HDLC_GET_DATA;
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hdlc->do_adapt56 = do_adapt56;
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hdlc->dchannel = 0;
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hdlc->crc = 0;
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hdlc->cbin = 0;
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hdlc->shift_reg = 0;
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hdlc->ffvalue = 0;
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hdlc->dstpos = 0;
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}
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void isdnhdlc_out_init (struct isdnhdlc_vars *hdlc, int is_d_channel, int do_adapt56)
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{
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hdlc->bit_shift = 0;
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hdlc->hdlc_bits1 = 0;
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hdlc->data_bits = 0;
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hdlc->ffbit_shift = 0;
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hdlc->data_received = 0;
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hdlc->do_closing = 0;
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hdlc->ffvalue = 0;
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if (is_d_channel) {
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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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hdlc->dchannel = 0;
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hdlc->state = HDLC_SEND_FAST_FLAG;
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hdlc->ffvalue = 0x7e;
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}
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hdlc->cbin = 0x7e;
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hdlc->bit_shift = 0;
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if(do_adapt56){
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hdlc->do_adapt56 = 1;
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hdlc->data_bits = 0;
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hdlc->state = HDLC_SENDFLAG_B0;
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} else {
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hdlc->do_adapt56 = 0;
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hdlc->data_bits = 8;
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}
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hdlc->shift_reg = 0;
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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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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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the frame is found, the bit stuffing is removed (0 after 5 1's).
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When a new flag is found, the complete frame has been received
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and the CRC is checked.
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If a valid frame is found, the function returns the frame length
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excluding the CRC with the bit HDLC_END_OF_FRAME set.
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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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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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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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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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*/
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int isdnhdlc_decode (struct isdnhdlc_vars *hdlc, const unsigned char *src,
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int slen, int *count, unsigned char *dst, int dsize)
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{
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int status=0;
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static const unsigned char fast_flag[]={
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0x00,0x00,0x00,0x20,0x30,0x38,0x3c,0x3e,0x3f
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};
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static const unsigned char fast_flag_value[]={
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0x00,0x7e,0xfc,0xf9,0xf3,0xe7,0xcf,0x9f,0x3f
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};
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static const unsigned char fast_abort[]={
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0x00,0x00,0x80,0xc0,0xe0,0xf0,0xf8,0xfc,0xfe,0xff
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};
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*count = slen;
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while(slen > 0){
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if(hdlc->bit_shift==0){
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hdlc->cbin = *src++;
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slen--;
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hdlc->bit_shift = 8;
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if(hdlc->do_adapt56){
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hdlc->bit_shift --;
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}
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}
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switch(hdlc->state){
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case STOPPED:
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return 0;
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case HDLC_FAST_IDLE:
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if(hdlc->cbin == 0xff){
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hdlc->bit_shift = 0;
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break;
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}
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hdlc->state = HDLC_GET_FLAG_B0;
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hdlc->hdlc_bits1 = 0;
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hdlc->bit_shift = 8;
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break;
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case HDLC_GET_FLAG_B0:
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if(!(hdlc->cbin & 0x80)) {
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hdlc->state = HDLC_GETFLAG_B1A6;
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hdlc->hdlc_bits1 = 0;
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} else {
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if(!hdlc->do_adapt56){
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if(++hdlc->hdlc_bits1 >=8 ) if(hdlc->bit_shift==1)
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hdlc->state = HDLC_FAST_IDLE;
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}
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}
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hdlc->cbin<<=1;
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hdlc->bit_shift --;
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break;
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case HDLC_GETFLAG_B1A6:
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if(hdlc->cbin & 0x80){
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hdlc->hdlc_bits1++;
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if(hdlc->hdlc_bits1==6){
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hdlc->state = HDLC_GETFLAG_B7;
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}
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} else {
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hdlc->hdlc_bits1 = 0;
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}
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hdlc->cbin<<=1;
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hdlc->bit_shift --;
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break;
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case HDLC_GETFLAG_B7:
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if(hdlc->cbin & 0x80) {
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hdlc->state = HDLC_GET_FLAG_B0;
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} else {
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hdlc->state = HDLC_GET_DATA;
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hdlc->crc = 0xffff;
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hdlc->shift_reg = 0;
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hdlc->hdlc_bits1 = 0;
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hdlc->data_bits = 0;
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hdlc->data_received = 0;
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}
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hdlc->cbin<<=1;
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hdlc->bit_shift --;
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break;
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case HDLC_GET_DATA:
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if(hdlc->cbin & 0x80){
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hdlc->hdlc_bits1++;
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switch(hdlc->hdlc_bits1){
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case 6:
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break;
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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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}
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if(!hdlc->do_adapt56){
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if(hdlc->cbin==fast_abort[hdlc->bit_shift+1]){
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hdlc->state = HDLC_FAST_IDLE;
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hdlc->bit_shift=1;
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break;
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}
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} else {
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hdlc->state = HDLC_GET_FLAG_B0;
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}
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break;
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default:
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hdlc->shift_reg>>=1;
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hdlc->shift_reg |= 0x80;
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hdlc->data_bits++;
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break;
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}
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} else {
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switch(hdlc->hdlc_bits1){
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case 5:
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break;
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case 6:
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if(hdlc->data_received){
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if (hdlc->dstpos < 2) {
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status = -HDLC_FRAMING_ERROR;
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} else if (hdlc->crc != 0xf0b8){
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// crc error
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status = -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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// good frame
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status = hdlc->dstpos;
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}
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}
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hdlc->crc = 0xffff;
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hdlc->shift_reg = 0;
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hdlc->data_bits = 0;
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if(!hdlc->do_adapt56){
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if(hdlc->cbin==fast_flag[hdlc->bit_shift]){
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hdlc->ffvalue = fast_flag_value[hdlc->bit_shift];
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hdlc->state = HDLC_FAST_FLAG;
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hdlc->ffbit_shift = hdlc->bit_shift;
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hdlc->bit_shift = 1;
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} else {
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hdlc->state = HDLC_GET_DATA;
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hdlc->data_received = 0;
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}
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} else {
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hdlc->state = HDLC_GET_DATA;
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hdlc->data_received = 0;
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}
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break;
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default:
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hdlc->shift_reg>>=1;
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hdlc->data_bits++;
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break;
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}
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hdlc->hdlc_bits1 = 0;
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}
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if (status) {
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hdlc->dstpos = 0;
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*count -= slen;
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hdlc->cbin <<= 1;
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hdlc->bit_shift--;
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return status;
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}
|
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if(hdlc->data_bits==8){
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hdlc->data_bits = 0;
|
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hdlc->data_received = 1;
|
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hdlc->crc = crc_ccitt_byte(hdlc->crc, hdlc->shift_reg);
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|
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// good byte received
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if (hdlc->dstpos < dsize) {
|
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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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hdlc->dstpos = 0;
|
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}
|
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}
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hdlc->cbin <<= 1;
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hdlc->bit_shift--;
|
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break;
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case HDLC_FAST_FLAG:
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if(hdlc->cbin==hdlc->ffvalue){
|
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hdlc->bit_shift = 0;
|
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break;
|
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|
} else {
|
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|
if(hdlc->cbin == 0xff){
|
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hdlc->state = HDLC_FAST_IDLE;
|
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hdlc->bit_shift=0;
|
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|
} else if(hdlc->ffbit_shift==8){
|
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|
hdlc->state = HDLC_GETFLAG_B7;
|
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break;
|
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|
} else {
|
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|
hdlc->shift_reg = fast_abort[hdlc->ffbit_shift-1];
|
|||
|
hdlc->hdlc_bits1 = hdlc->ffbit_shift-2;
|
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|
if(hdlc->hdlc_bits1<0)hdlc->hdlc_bits1 = 0;
|
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|
hdlc->data_bits = hdlc->ffbit_shift-1;
|
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|
hdlc->state = HDLC_GET_DATA;
|
|||
|
hdlc->data_received = 0;
|
|||
|
}
|
|||
|
}
|
|||
|
break;
|
|||
|
default:
|
|||
|
break;
|
|||
|
}
|
|||
|
}
|
|||
|
*count -= slen;
|
|||
|
return 0;
|
|||
|
}
|
|||
|
|
|||
|
/*
|
|||
|
isdnhdlc_encode - encodes HDLC frames to a transparent bit stream.
|
|||
|
|
|||
|
The bit stream starts with a beginning flag (01111110). After
|
|||
|
that each byte is added to the bit stream with bit stuffing added
|
|||
|
(0 after 5 1's).
|
|||
|
When the last byte has been removed from the source buffer, the
|
|||
|
CRC (2 bytes is added) and the frame terminates with the ending flag.
|
|||
|
For the dchannel, the idle character (all 1's) is also added at the end.
|
|||
|
If this function is called with empty source buffer (slen=0), flags or
|
|||
|
idle character will be generated.
|
|||
|
|
|||
|
src - source buffer
|
|||
|
slen - source buffer length
|
|||
|
count - number of bytes removed (encoded) from source buffer
|
|||
|
dst _ destination buffer
|
|||
|
dsize - destination buffer size
|
|||
|
returns - number of encoded bytes in the destination buffer
|
|||
|
*/
|
|||
|
int isdnhdlc_encode(struct isdnhdlc_vars *hdlc, const unsigned char *src,
|
|||
|
unsigned short slen, int *count,
|
|||
|
unsigned char *dst, int dsize)
|
|||
|
{
|
|||
|
static const unsigned char xfast_flag_value[] = {
|
|||
|
0x7e,0x3f,0x9f,0xcf,0xe7,0xf3,0xf9,0xfc,0x7e
|
|||
|
};
|
|||
|
|
|||
|
int len = 0;
|
|||
|
|
|||
|
*count = slen;
|
|||
|
|
|||
|
while (dsize > 0) {
|
|||
|
if(hdlc->bit_shift==0){
|
|||
|
if(slen && !hdlc->do_closing){
|
|||
|
hdlc->shift_reg = *src++;
|
|||
|
slen--;
|
|||
|
if (slen == 0)
|
|||
|
hdlc->do_closing = 1; /* closing sequence, CRC + flag(s) */
|
|||
|
hdlc->bit_shift = 8;
|
|||
|
} else {
|
|||
|
if(hdlc->state == HDLC_SEND_DATA){
|
|||
|
if(hdlc->data_received){
|
|||
|
hdlc->state = HDLC_SEND_CRC1;
|
|||
|
hdlc->crc ^= 0xffff;
|
|||
|
hdlc->bit_shift = 8;
|
|||
|
hdlc->shift_reg = hdlc->crc & 0xff;
|
|||
|
} else if(!hdlc->do_adapt56){
|
|||
|
hdlc->state = HDLC_SEND_FAST_FLAG;
|
|||
|
} else {
|
|||
|
hdlc->state = HDLC_SENDFLAG_B0;
|
|||
|
}
|
|||
|
}
|
|||
|
|
|||
|
}
|
|||
|
}
|
|||
|
|
|||
|
switch(hdlc->state){
|
|||
|
case STOPPED:
|
|||
|
while (dsize--)
|
|||
|
*dst++ = 0xff;
|
|||
|
|
|||
|
return dsize;
|
|||
|
case HDLC_SEND_FAST_FLAG:
|
|||
|
hdlc->do_closing = 0;
|
|||
|
if(slen == 0){
|
|||
|
*dst++ = hdlc->ffvalue;
|
|||
|
len++;
|
|||
|
dsize--;
|
|||
|
break;
|
|||
|
}
|
|||
|
if(hdlc->bit_shift==8){
|
|||
|
hdlc->cbin = hdlc->ffvalue>>(8-hdlc->data_bits);
|
|||
|
hdlc->state = HDLC_SEND_DATA;
|
|||
|
hdlc->crc = 0xffff;
|
|||
|
hdlc->hdlc_bits1 = 0;
|
|||
|
hdlc->data_received = 1;
|
|||
|
}
|
|||
|
break;
|
|||
|
case HDLC_SENDFLAG_B0:
|
|||
|
hdlc->do_closing = 0;
|
|||
|
hdlc->cbin <<= 1;
|
|||
|
hdlc->data_bits++;
|
|||
|
hdlc->hdlc_bits1 = 0;
|
|||
|
hdlc->state = HDLC_SENDFLAG_B1A6;
|
|||
|
break;
|
|||
|
case HDLC_SENDFLAG_B1A6:
|
|||
|
hdlc->cbin <<= 1;
|
|||
|
hdlc->data_bits++;
|
|||
|
hdlc->cbin++;
|
|||
|
if(++hdlc->hdlc_bits1 == 6)
|
|||
|
hdlc->state = HDLC_SENDFLAG_B7;
|
|||
|
break;
|
|||
|
case HDLC_SENDFLAG_B7:
|
|||
|
hdlc->cbin <<= 1;
|
|||
|
hdlc->data_bits++;
|
|||
|
if(slen == 0){
|
|||
|
hdlc->state = HDLC_SENDFLAG_B0;
|
|||
|
break;
|
|||
|
}
|
|||
|
if(hdlc->bit_shift==8){
|
|||
|
hdlc->state = HDLC_SEND_DATA;
|
|||
|
hdlc->crc = 0xffff;
|
|||
|
hdlc->hdlc_bits1 = 0;
|
|||
|
hdlc->data_received = 1;
|
|||
|
}
|
|||
|
break;
|
|||
|
case HDLC_SEND_FIRST_FLAG:
|
|||
|
hdlc->data_received = 1;
|
|||
|
if(hdlc->data_bits==8){
|
|||
|
hdlc->state = HDLC_SEND_DATA;
|
|||
|
hdlc->crc = 0xffff;
|
|||
|
hdlc->hdlc_bits1 = 0;
|
|||
|
break;
|
|||
|
}
|
|||
|
hdlc->cbin <<= 1;
|
|||
|
hdlc->data_bits++;
|
|||
|
if(hdlc->shift_reg & 0x01)
|
|||
|
hdlc->cbin++;
|
|||
|
hdlc->shift_reg >>= 1;
|
|||
|
hdlc->bit_shift--;
|
|||
|
if(hdlc->bit_shift==0){
|
|||
|
hdlc->state = HDLC_SEND_DATA;
|
|||
|
hdlc->crc = 0xffff;
|
|||
|
hdlc->hdlc_bits1 = 0;
|
|||
|
}
|
|||
|
break;
|
|||
|
case HDLC_SEND_DATA:
|
|||
|
hdlc->cbin <<= 1;
|
|||
|
hdlc->data_bits++;
|
|||
|
if(hdlc->hdlc_bits1 == 5){
|
|||
|
hdlc->hdlc_bits1 = 0;
|
|||
|
break;
|
|||
|
}
|
|||
|
if(hdlc->bit_shift==8){
|
|||
|
hdlc->crc = crc_ccitt_byte(hdlc->crc, hdlc->shift_reg);
|
|||
|
}
|
|||
|
if(hdlc->shift_reg & 0x01){
|
|||
|
hdlc->hdlc_bits1++;
|
|||
|
hdlc->cbin++;
|
|||
|
hdlc->shift_reg >>= 1;
|
|||
|
hdlc->bit_shift--;
|
|||
|
} else {
|
|||
|
hdlc->hdlc_bits1 = 0;
|
|||
|
hdlc->shift_reg >>= 1;
|
|||
|
hdlc->bit_shift--;
|
|||
|
}
|
|||
|
break;
|
|||
|
case HDLC_SEND_CRC1:
|
|||
|
hdlc->cbin <<= 1;
|
|||
|
hdlc->data_bits++;
|
|||
|
if(hdlc->hdlc_bits1 == 5){
|
|||
|
hdlc->hdlc_bits1 = 0;
|
|||
|
break;
|
|||
|
}
|
|||
|
if(hdlc->shift_reg & 0x01){
|
|||
|
hdlc->hdlc_bits1++;
|
|||
|
hdlc->cbin++;
|
|||
|
hdlc->shift_reg >>= 1;
|
|||
|
hdlc->bit_shift--;
|
|||
|
} else {
|
|||
|
hdlc->hdlc_bits1 = 0;
|
|||
|
hdlc->shift_reg >>= 1;
|
|||
|
hdlc->bit_shift--;
|
|||
|
}
|
|||
|
if(hdlc->bit_shift==0){
|
|||
|
hdlc->shift_reg = (hdlc->crc >> 8);
|
|||
|
hdlc->state = HDLC_SEND_CRC2;
|
|||
|
hdlc->bit_shift = 8;
|
|||
|
}
|
|||
|
break;
|
|||
|
case HDLC_SEND_CRC2:
|
|||
|
hdlc->cbin <<= 1;
|
|||
|
hdlc->data_bits++;
|
|||
|
if(hdlc->hdlc_bits1 == 5){
|
|||
|
hdlc->hdlc_bits1 = 0;
|
|||
|
break;
|
|||
|
}
|
|||
|
if(hdlc->shift_reg & 0x01){
|
|||
|
hdlc->hdlc_bits1++;
|
|||
|
hdlc->cbin++;
|
|||
|
hdlc->shift_reg >>= 1;
|
|||
|
hdlc->bit_shift--;
|
|||
|
} else {
|
|||
|
hdlc->hdlc_bits1 = 0;
|
|||
|
hdlc->shift_reg >>= 1;
|
|||
|
hdlc->bit_shift--;
|
|||
|
}
|
|||
|
if(hdlc->bit_shift==0){
|
|||
|
hdlc->shift_reg = 0x7e;
|
|||
|
hdlc->state = HDLC_SEND_CLOSING_FLAG;
|
|||
|
hdlc->bit_shift = 8;
|
|||
|
}
|
|||
|
break;
|
|||
|
case HDLC_SEND_CLOSING_FLAG:
|
|||
|
hdlc->cbin <<= 1;
|
|||
|
hdlc->data_bits++;
|
|||
|
if(hdlc->hdlc_bits1 == 5){
|
|||
|
hdlc->hdlc_bits1 = 0;
|
|||
|
break;
|
|||
|
}
|
|||
|
if(hdlc->shift_reg & 0x01){
|
|||
|
hdlc->cbin++;
|
|||
|
}
|
|||
|
hdlc->shift_reg >>= 1;
|
|||
|
hdlc->bit_shift--;
|
|||
|
if(hdlc->bit_shift==0){
|
|||
|
hdlc->ffvalue = xfast_flag_value[hdlc->data_bits];
|
|||
|
if(hdlc->dchannel){
|
|||
|
hdlc->ffvalue = 0x7e;
|
|||
|
hdlc->state = HDLC_SEND_IDLE1;
|
|||
|
hdlc->bit_shift = 8-hdlc->data_bits;
|
|||
|
if(hdlc->bit_shift==0)
|
|||
|
hdlc->state = HDLC_SEND_FAST_IDLE;
|
|||
|
} else {
|
|||
|
if(!hdlc->do_adapt56){
|
|||
|
hdlc->state = HDLC_SEND_FAST_FLAG;
|
|||
|
hdlc->data_received = 0;
|
|||
|
} else {
|
|||
|
hdlc->state = HDLC_SENDFLAG_B0;
|
|||
|
hdlc->data_received = 0;
|
|||
|
}
|
|||
|
// Finished with this frame, send flags
|
|||
|
if (dsize > 1) dsize = 1;
|
|||
|
}
|
|||
|
}
|
|||
|
break;
|
|||
|
case HDLC_SEND_IDLE1:
|
|||
|
hdlc->do_closing = 0;
|
|||
|
hdlc->cbin <<= 1;
|
|||
|
hdlc->cbin++;
|
|||
|
hdlc->data_bits++;
|
|||
|
hdlc->bit_shift--;
|
|||
|
if(hdlc->bit_shift==0){
|
|||
|
hdlc->state = HDLC_SEND_FAST_IDLE;
|
|||
|
hdlc->bit_shift = 0;
|
|||
|
}
|
|||
|
break;
|
|||
|
case HDLC_SEND_FAST_IDLE:
|
|||
|
hdlc->do_closing = 0;
|
|||
|
hdlc->cbin = 0xff;
|
|||
|
hdlc->data_bits = 8;
|
|||
|
if(hdlc->bit_shift == 8){
|
|||
|
hdlc->cbin = 0x7e;
|
|||
|
hdlc->state = HDLC_SEND_FIRST_FLAG;
|
|||
|
} else {
|
|||
|
*dst++ = hdlc->cbin;
|
|||
|
hdlc->bit_shift = hdlc->data_bits = 0;
|
|||
|
len++;
|
|||
|
dsize = 0;
|
|||
|
}
|
|||
|
break;
|
|||
|
default:
|
|||
|
break;
|
|||
|
}
|
|||
|
if(hdlc->do_adapt56){
|
|||
|
if(hdlc->data_bits==7){
|
|||
|
hdlc->cbin <<= 1;
|
|||
|
hdlc->cbin++;
|
|||
|
hdlc->data_bits++;
|
|||
|
}
|
|||
|
}
|
|||
|
if(hdlc->data_bits==8){
|
|||
|
*dst++ = hdlc->cbin;
|
|||
|
hdlc->data_bits = 0;
|
|||
|
len++;
|
|||
|
dsize--;
|
|||
|
}
|
|||
|
}
|
|||
|
*count -= slen;
|
|||
|
|
|||
|
return len;
|
|||
|
}
|
|||
|
|
|||
|
EXPORT_SYMBOL(isdnhdlc_bit_rev_tab);
|
|||
|
EXPORT_SYMBOL(isdnhdlc_rcv_init);
|
|||
|
EXPORT_SYMBOL(isdnhdlc_decode);
|
|||
|
EXPORT_SYMBOL(isdnhdlc_out_init);
|
|||
|
EXPORT_SYMBOL(isdnhdlc_encode);
|