hid-keyboard-dongle-nRF/SDK/nRF5_SDK_17.0.2_d674dde/components/libraries/slip/slip.h

118 lines
5.1 KiB
C

/**
* Copyright (c) 2015 - 2020, Nordic Semiconductor ASA
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form, except as embedded into a Nordic
* Semiconductor ASA integrated circuit in a product or a software update for
* such product, must reproduce the above copyright notice, this list of
* conditions and the following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* 3. Neither the name of Nordic Semiconductor ASA nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* 4. This software, with or without modification, must only be used with a
* Nordic Semiconductor ASA integrated circuit.
*
* 5. Any software provided in binary form under this license must not be reverse
* engineered, decompiled, modified and/or disassembled.
*
* THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
#ifndef SLIP_H__
#define SLIP_H__
#include <stdint.h>
#include "sdk_errors.h"
#ifdef __cplusplus
extern "C" {
#endif
/** @file
*
* @defgroup slip SLIP encoding and decoding
* @{
* @ingroup app_common
*
* @brief This module encodes and decodes SLIP packages.
*
* @details The SLIP protocol is described in @linkSLIP.
*/
/** @brief Status information that is used while receiving and decoding a packet. */
typedef enum
{
SLIP_STATE_DECODING, //!< Ready to receive the next byte.
SLIP_STATE_ESC_RECEIVED, //!< An ESC byte has been received and the next byte must be decoded differently.
SLIP_STATE_CLEARING_INVALID_PACKET //!< The received data is invalid and transfer must be restarted.
} slip_read_state_t;
/** @brief Representation of a SLIP packet. */
typedef struct
{
slip_read_state_t state; //!< Current state of the packet (see @ref slip_read_state_t).
uint8_t * p_buffer; //!< Decoded data.
uint32_t current_index; //!< Current length of the packet that has been received.
uint32_t buffer_len; //!< Size of the buffer that is available.
} slip_t;
/**@brief Function for encoding a SLIP packet.
*
* The maximum size of the output data is (2*input size + 1) bytes. Ensure that the provided buffer is large enough.
*
* @param[in,out] p_output The buffer where the encoded SLIP packet is stored. Ensure that it is large enough.
* @param[in,out] p_input The buffer to be encoded.
* @param[in,out] input_length The length of the input buffer.
* @param[out] p_output_buffer_length The length of the output buffer after the input has been encoded.
*
* @retval NRF_SUCCESS If the input was successfully encoded into output.
* @retval NRF_ERROR_NULL If one of the provided parameters is NULL.
*/
ret_code_t slip_encode(uint8_t * p_output, uint8_t * p_input, uint32_t input_length, uint32_t * p_output_buffer_length);
/**@brief Function for decoding a SLIP packet.
*
* The decoded packet is put into @p p_slip::p_buffer. The index and buffer state is updated.
*
* Ensure that @p p_slip is properly initialized. The initial state must be set to @ref SLIP_STATE_DECODING.
*
* @param[in,out] p_slip State of the decoding process.
* @param[in] c Byte to decode.
*
* @retval NRF_SUCCESS If a packet has been parsed. The received packet can be retrieved from @p p_slip.
* @retval NRF_ERROR_NULL If @p p_slip is NULL.
* @retval NRF_ERROR_NO_MEM If there is no more room in the buffer provided by @p p_slip.
* @retval NRF_ERROR_BUSY If the packet has not been parsed completely yet.
* @retval NRF_ERROR_INVALID_DATA If the packet is encoded wrong. In this case, @p p_slip::state is set to @ref SLIP_STATE_CLEARING_INVALID_PACKET,
* and decoding will stay in this state until the END byte is received.
*/
ret_code_t slip_decode_add_byte(slip_t * p_slip, uint8_t c);
#ifdef __cplusplus
}
#endif
#endif // SLIP_H__
/** @} */