kopia lustrzana https://github.com/sq8vps/vp-digi
99 wiersze
2.6 KiB
C
99 wiersze
2.6 KiB
C
/*
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Copyright 2020-2023 Piotr Wilkon
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This file is part of VP-Digi.
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VP-Digi 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 3 of the License, or
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(at your option) any later version.
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VP-Digi 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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You should have received a copy of the GNU General Public License
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along with VP-Digi. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "kiss.h"
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#include "ax25.h"
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#include "digipeater.h"
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void KissSend(Uart *port, uint8_t *buf, uint16_t size)
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{
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if(port->mode == MODE_KISS)
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{
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UartSendByte(port, 0xC0);
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UartSendByte(port, 0x00);
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for(uint16_t i = 0; i < size; i++)
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{
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if(buf[i] == 0xC0) //frame end in data
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{
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UartSendByte(port, 0xDB); //frame escape
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UartSendByte(port, 0xDC); //transposed frame end
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}
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else if(buf[i] == 0xDB) //frame escape in data
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{
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UartSendByte(port, 0xDB); //frame escape
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UartSendByte(port, 0xDD); //transposed frame escape
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}
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else
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UartSendByte(port, buf[i]);
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}
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UartSendByte(port, 0xC0);
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}
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}
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void KissParse(Uart *port, uint8_t data)
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{
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if(data == 0xC0) //frame end marker
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{
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if(port->kissBufferHead < 16) //command+source+destination+Control=16
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{
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port->kissBufferHead = 0;
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return;
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}
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if((port->kissBuffer[0] & 0xF) != 0) //check if this is an actual frame
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{
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port->kissBufferHead = 0;
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return;
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}
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//simple sanity check
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//check if LSbits in the first 13 bytes are set to 0
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//they should always be in an AX.25 frame
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for(uint8_t i = 0; i < 13; i++)
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{
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if((port->kissBuffer[i + 1] & 1) != 0)
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{
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port->kissBufferHead = 0;
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return;
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}
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}
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Ax25WriteTxFrame((uint8_t*)&port->kissBuffer[1], port->kissBufferHead - 1);
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DigiStoreDeDupe((uint8_t*)&port->kissBuffer[1], port->kissBufferHead - 1);
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port->kissBufferHead = 0;
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return;
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}
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else if(port->kissBufferHead > 0)
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{
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if((data == 0xDC) && (port->kissBuffer[port->kissBufferHead - 1] == 0xDB)) //escape character with transposed frame end
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{
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port->kissBuffer[port->kissBufferHead - 1] = 0xC0;
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return;
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}
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else if((data == 0xDD) && (port->kissBuffer[port->kissBufferHead - 1] == 0xDB)) //escape character with transposed escape character
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{
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port->kissBuffer[port->kissBufferHead - 1] = 0xDB;
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return;
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}
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}
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port->kissBuffer[port->kissBufferHead++] = data;
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port->kissBufferHead %= sizeof(port->kissBuffer);
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}
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