acn_pdu.h

/******************************************************************************
 * Copyright 2022 ETC Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *******************************************************************************
 * This file is a part of EtcPal. For more information, go to:
 * https://github.com/ETCLabs/EtcPal
 ******************************************************************************/
 
/* etcpal/acn_pdu.h: Functions to parse and pack a generic ACN PDU as defined in ANSI E1.17. */
 
#ifndef ETCPAL_ACN_PDU_H_
#define ETCPAL_ACN_PDU_H_
 
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
 
#define ACN_PDU_L_FLAG_SET(flags_byte) ((bool)((flags_byte)&0x80u))
 
#define ACN_PDU_V_FLAG_SET(flags_byte) ((bool)((flags_byte)&0x40u))
 
#define ACN_PDU_H_FLAG_SET(flags_byte) ((bool)((flags_byte)&0x20u))
 
#define ACN_PDU_D_FLAG_SET(flags_byte) ((bool)((flags_byte)&0x10u))
 
#define ACN_PDU_LENGTH(pdu_buf)                                                                                   \
  ((uint32_t)(ACN_PDU_L_FLAG_SET(pdu_buf[0])                                                                      \
                  ? ((uint32_t)((pdu_buf[0] & 0x0fu) << 16) | (uint32_t)(pdu_buf[1] << 8) | (uint32_t)pdu_buf[2]) \
                  : ((uint32_t)((pdu_buf[0] & 0x0fu) << 8) | (uint32_t)pdu_buf[1])))
 
#define ACN_PDU_SET_L_FLAG(flags_byte) (flags_byte |= 0x80u)
 
#define ACN_PDU_SET_V_FLAG(flags_byte) (flags_byte |= 0x40u)
 
#define ACN_PDU_SET_H_FLAG(flags_byte) (flags_byte |= 0x20u)
 
#define ACN_PDU_SET_D_FLAG(flags_byte) (flags_byte |= 0x10u)
 
#define ACN_PDU_PACK_NORMAL_LEN(pdu_buf, length)                                 \
  do                                                                             \
  {                                                                              \
    (pdu_buf)[0] = (uint8_t)(((pdu_buf)[0] & 0xf0) | (((length) >> 8) & 0x0fu)); \
    (pdu_buf)[1] = (uint8_t)(length)&0xffu;                                      \
  } while (0)
 
#define ACN_PDU_PACK_EXT_LEN(pdu_buf, length)                                     \
  do                                                                              \
  {                                                                               \
    (pdu_buf)[0] = (uint8_t)(((pdu_buf)[0] & 0xf0) | (((length) >> 16) & 0x0fu)); \
    (pdu_buf)[1] = (uint8_t)(((length) >> 8) & 0xffu);                            \
    (pdu_buf)[2] = (uint8_t)(length)&0xffu;                                       \
  } while (0)
 
typedef struct AcnPdu
{
  const uint8_t* pvector;  
  const uint8_t* pheader;  
  const uint8_t* pdata;    
  size_t         data_len; 
  const uint8_t* pnextpdu; 
} AcnPdu;
 
#define ACN_PDU_INIT          \
  {                           \
    NULL, NULL, NULL, 0, NULL \
  }
 
#define ACN_INIT_PDU(pduptr)   \
  do                           \
  {                            \
    (pduptr)->pvector  = NULL; \
    (pduptr)->pheader  = NULL; \
    (pduptr)->pdata    = NULL; \
    (pduptr)->data_len = 0;    \
    (pduptr)->pnextpdu = NULL; \
  } while (0)
 
typedef struct AcnPduConstraints
{
  size_t vector_size; 
  size_t header_size; 
} AcnPduConstraints;
 
#ifdef __cplusplus
extern "C" {
#endif
 
bool acn_parse_pdu(const uint8_t* buf, size_t buflen, const AcnPduConstraints* constraints, AcnPdu* pdu);
 
#ifdef __cplusplus
}
#endif
 
#endif /* ETCPAL_ACN_PDU_H_ */