lwpa_pdu.h

/******************************************************************************
 * Copyright 2018 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 lwpa. For more information, go to:
 * https://github.com/ETCLabs/lwpa
 ******************************************************************************/
 
/* pdu.h: Functions to parse and pack a generic PDU as defined in ANSI
 * E1.17. */
#ifndef _LWPA_PDU_H_
#define _LWPA_PDU_H_
 
#include <stddef.h>
#include "lwpa_int.h"
#include "lwpa_bool.h"
 
#define l_flag_set(flags_byte) ((bool)(flags_byte & 0x80))
#define v_flag_set(flags_byte) ((bool)(flags_byte & 0x40))
#define h_flag_set(flags_byte) ((bool)(flags_byte & 0x20))
#define d_flag_set(flags_byte) ((bool)(flags_byte & 0x10))
#define pdu_length(pdu_buf)                                                                           \
  ((uint32_t)(l_flag_set(pdu_buf[0]) ? (((pdu_buf[0] & 0x0f) << 16) | (pdu_buf[1] << 8) | pdu_buf[2]) \
                                     : (((pdu_buf[0] & 0x0f) << 8) | pdu_buf[1])))
 
#define set_l_flag(flags_byte) (flags_byte |= 0x80)
#define set_v_flag(flags_byte) (flags_byte |= 0x40)
#define set_h_flag(flags_byte) (flags_byte |= 0x20)
#define set_d_flag(flags_byte) (flags_byte |= 0x10)
#define pdu_pack_normal_len(pdu_buf, length)                           \
  do                                                                   \
  {                                                                    \
    (pdu_buf)[0] = (((pdu_buf)[0] & 0xf0) | (((length) >> 8) & 0x0f)); \
    (pdu_buf)[1] = (length)&0xff;                                      \
  } while (0)
 
#define pdu_pack_ext_len(pdu_buf, length)                               \
  do                                                                    \
  {                                                                     \
    (pdu_buf)[0] = (((pdu_buf)[0] & 0xf0) | (((length) >> 16) & 0x0f)); \
    (pdu_buf)[1] = (((length) >> 8) & 0xff);                            \
    (pdu_buf)[2] = (length)&0xff;                                       \
  } while (0)
 
typedef struct LwpaPdu
{
  const uint8_t *pvector;
  const uint8_t *pheader;
  const uint8_t *pdata;
  size_t datalen;
  const uint8_t *pnextpdu;
} LwpaPdu;
 
#define PDU_INIT              \
  {                           \
    NULL, NULL, NULL, 0, NULL \
  }
 
#define init_pdu(pduptr)       \
  do                           \
  {                            \
    (pduptr)->pvector = NULL;  \
    (pduptr)->pheader = NULL;  \
    (pduptr)->pdata = NULL;    \
    (pduptr)->datalen = 0;     \
    (pduptr)->pnextpdu = NULL; \
  } while (0)
 
typedef struct LwpaPduConstraints
{
  size_t vector_size; 
  size_t header_size; 
} LwpaPduConstraints;
 
#ifdef __cplusplus
extern "C" {
#endif
 
bool parse_pdu(const uint8_t *buf, size_t buflen, const LwpaPduConstraints *constraints, LwpaPdu *pdu);
 
#ifdef __cplusplus
}
#endif
 
#endif /* _LWPA_PDU_H_ */