151 lines
5.3 KiB
C
151 lines
5.3 KiB
C
/**
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* Copyright (c) 2015 - 2020, Nordic Semiconductor ASA
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*
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without modification,
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* are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice, this
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* list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form, except as embedded into a Nordic
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* Semiconductor ASA integrated circuit in a product or a software update for
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* such product, must reproduce the above copyright notice, this list of
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* conditions and the following disclaimer in the documentation and/or other
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* materials provided with the distribution.
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*
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* 3. Neither the name of Nordic Semiconductor ASA nor the names of its
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* contributors may be used to endorse or promote products derived from this
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* software without specific prior written permission.
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*
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* 4. This software, with or without modification, must only be used with a
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* Nordic Semiconductor ASA integrated circuit.
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*
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* 5. Any software provided in binary form under this license must not be reverse
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* engineered, decompiled, modified and/or disassembled.
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*
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* THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
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* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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#include "sdk_common.h"
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#if NRF_MODULE_ENABLED(SLIP)
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#include "slip.h"
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#include <string.h>
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#define SLIP_BYTE_END 0300 /* indicates end of packet */
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#define SLIP_BYTE_ESC 0333 /* indicates byte stuffing */
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#define SLIP_BYTE_ESC_END 0334 /* ESC ESC_END means END data byte */
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#define SLIP_BYTE_ESC_ESC 0335 /* ESC ESC_ESC means ESC data byte */
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ret_code_t slip_encode(uint8_t * p_output, uint8_t * p_input, uint32_t input_length, uint32_t * p_output_buffer_length)
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{
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if (p_output == NULL || p_input == NULL || p_output_buffer_length == NULL)
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{
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return NRF_ERROR_NULL;
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}
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*p_output_buffer_length = 0;
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uint32_t input_index;
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for (input_index = 0; input_index < input_length; input_index++)
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{
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switch (p_input[input_index])
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{
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case SLIP_BYTE_END:
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p_output[(*p_output_buffer_length)++] = SLIP_BYTE_ESC;
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p_output[(*p_output_buffer_length)++] = SLIP_BYTE_ESC_END;
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break;
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case SLIP_BYTE_ESC:
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p_output[(*p_output_buffer_length)++] = SLIP_BYTE_ESC;
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p_output[(*p_output_buffer_length)++] = SLIP_BYTE_ESC_ESC;
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break;
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default:
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p_output[(*p_output_buffer_length)++] = p_input[input_index];
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}
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}
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p_output[(*p_output_buffer_length)++] = SLIP_BYTE_END;
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return NRF_SUCCESS;
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}
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ret_code_t slip_decode_add_byte(slip_t * p_slip, uint8_t c)
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{
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if (p_slip == NULL)
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{
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return NRF_ERROR_NULL;
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}
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if (p_slip->current_index == p_slip->buffer_len)
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{
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return NRF_ERROR_NO_MEM;
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}
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switch (p_slip->state)
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{
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case SLIP_STATE_DECODING:
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switch (c)
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{
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case SLIP_BYTE_END:
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// finished reading packet
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return NRF_SUCCESS;
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case SLIP_BYTE_ESC:
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// wait for
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p_slip->state = SLIP_STATE_ESC_RECEIVED;
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break;
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default:
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// add byte to buffer
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p_slip->p_buffer[p_slip->current_index++] = c;
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break;
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}
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break;
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case SLIP_STATE_ESC_RECEIVED:
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switch (c)
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{
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case SLIP_BYTE_ESC_END:
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p_slip->p_buffer[p_slip->current_index++] = SLIP_BYTE_END;
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p_slip->state = SLIP_STATE_DECODING;
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break;
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case SLIP_BYTE_ESC_ESC:
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p_slip->p_buffer[p_slip->current_index++] = SLIP_BYTE_ESC;
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p_slip->state = SLIP_STATE_DECODING;
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break;
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default:
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// protocol violation
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p_slip->state = SLIP_STATE_CLEARING_INVALID_PACKET;
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return NRF_ERROR_INVALID_DATA;
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}
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break;
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case SLIP_STATE_CLEARING_INVALID_PACKET:
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if (c == SLIP_BYTE_END)
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{
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p_slip->state = SLIP_STATE_DECODING;
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p_slip->current_index = 0;
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}
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break;
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}
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return NRF_ERROR_BUSY;
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}
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#endif //NRF_MODULE_ENABLED(SLIP)
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