coap_pdu_internal.h

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/*
 * coap_pdu_internal.h -- CoAP PDU structure
 *
 * Copyright (C) 2010-2021 Olaf Bergmann <bergmann@tzi.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * This file is part of the CoAP library libcoap. Please see README for terms
 * of use.
 */
 
#ifndef COAP_COAP_PDU_INTERNAL_H_
#define COAP_COAP_PDU_INTERNAL_H_
 
#ifdef WITH_LWIP
#include <lwip/pbuf.h>
#endif
 
#include <stdint.h>
 
#define COAP_DEFAULT_VERSION      1 /* version of CoAP supported */
 
/* TCP Message format constants, do not modify */
#define COAP_MESSAGE_SIZE_OFFSET_TCP8 13
#define COAP_MESSAGE_SIZE_OFFSET_TCP16 269 /* 13 + 256 */
#define COAP_MESSAGE_SIZE_OFFSET_TCP32 65805 /* 269 + 65536 */
 
/* Derived message size limits */
#define COAP_MAX_MESSAGE_SIZE_TCP0 (COAP_MESSAGE_SIZE_OFFSET_TCP8-1) /* 12 */
#define COAP_MAX_MESSAGE_SIZE_TCP8 (COAP_MESSAGE_SIZE_OFFSET_TCP16-1) /* 268 */
#define COAP_MAX_MESSAGE_SIZE_TCP16 (COAP_MESSAGE_SIZE_OFFSET_TCP32-1) /* 65804 */
#define COAP_MAX_MESSAGE_SIZE_TCP32 (COAP_MESSAGE_SIZE_OFFSET_TCP32+0xFFFFFFFF)
 
#ifndef COAP_DEBUG_BUF_SIZE
#if defined(WITH_CONTIKI) || defined(WITH_LWIP)
#define COAP_DEBUG_BUF_SIZE 128
#else /* defined(WITH_CONTIKI) || defined(WITH_LWIP) */
/* 1024 derived from RFC7252 4.6.  Message Size max payload */
#define COAP_DEBUG_BUF_SIZE (8 + 1024 * 2)
#endif /* defined(WITH_CONTIKI) || defined(WITH_LWIP) */
#endif /* COAP_DEBUG_BUF_SIZE */
 
#ifndef COAP_DEFAULT_MAX_PDU_RX_SIZE
#if defined(WITH_CONTIKI) || defined(WITH_LWIP)
#define COAP_DEFAULT_MAX_PDU_RX_SIZE (COAP_MAX_MESSAGE_SIZE_TCP16+4UL)
#else
/* 8 MiB max-message-size plus some space for options */
#define COAP_DEFAULT_MAX_PDU_RX_SIZE (8UL*1024*1024+256)
#endif
#endif /* COAP_DEFAULT_MAX_PDU_RX_SIZE */
 
#define COAP_DROPPED_RESPONSE -2
 
#define COAP_PDU_DELAYED -3
 
#define COAP_PAYLOAD_START 0xFF /* payload marker */
 
#define COAP_PDU_IS_EMPTY(pdu)     ((pdu)->code == 0)
#define COAP_PDU_IS_REQUEST(pdu)   (!COAP_PDU_IS_EMPTY(pdu) && (pdu)->code < 32)
#define COAP_PDU_IS_RESPONSE(pdu)  ((pdu)->code >= 64 && (pdu)->code < 224)
#define COAP_PDU_IS_SIGNALING(pdu) ((pdu)->code >= 224)
 
#define COAP_PDU_MAX_UDP_HEADER_SIZE 4
#define COAP_PDU_MAX_TCP_HEADER_SIZE 6
 
struct coap_pdu_t {
  coap_pdu_type_t type;     
  coap_pdu_code_t code;     
  coap_mid_t mid;           
  uint8_t max_hdr_size;     
  uint8_t hdr_size;         
  uint8_t token_length;     
  uint16_t max_opt;         
  size_t alloc_size;        
  size_t used_size;         
  size_t max_size;          
  uint8_t *token;           
  uint8_t *data;            
#ifdef WITH_LWIP
  struct pbuf *pbuf;        
#endif
  const uint8_t *body_data; 
  size_t body_length;       
  size_t body_offset;       
  size_t body_total;        
  coap_lg_xmit_t *lg_xmit;  
};
 
int coap_pdu_resize(coap_pdu_t *pdu, size_t new_size);
 
int coap_pdu_check_resize(coap_pdu_t *pdu, size_t new_size);
 
size_t coap_pdu_parse_header_size(coap_proto_t proto,
                                 const uint8_t *data);
 
size_t coap_pdu_parse_size(coap_proto_t proto,
                           const uint8_t *data,
                           size_t length);
 
int coap_pdu_parse_header(coap_pdu_t *pdu, coap_proto_t proto);
 
int coap_pdu_parse_opt(coap_pdu_t *pdu);
 
int coap_pdu_parse(coap_proto_t proto,
                   const uint8_t *data,
                   size_t length,
                   coap_pdu_t *pdu);
 
void coap_pdu_clear(coap_pdu_t *pdu, size_t size);
 
int coap_remove_option(coap_pdu_t *pdu, coap_option_num_t number);
 
size_t coap_insert_option(coap_pdu_t *pdu, coap_option_num_t number,
                          size_t len, const uint8_t *data);
 
size_t coap_update_option(coap_pdu_t *pdu,
                          coap_option_num_t number,
                          size_t len,
                          const uint8_t *data);
 
size_t coap_pdu_encode_header(coap_pdu_t *pdu, coap_proto_t proto);
 
int coap_update_token(coap_pdu_t *pdu,
                      size_t len,
                      const uint8_t *data);
 
#endif /* COAP_COAP_PDU_INTERNAL_H_ */