block.h

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/*
 * block.h -- block transfer
 *
 * Copyright (C) 2010-2012,2014-2015 Olaf Bergmann <bergmann@tzi.org>
 * Copyright (C) 2022                Jon Shallow <supjps-libcoap@jpshallow.com>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * This file is part of the CoAP library libcoap. Please see README for terms
 * of use.
 */
 
#ifndef COAP_BLOCK_H_
#define COAP_BLOCK_H_
 
#include "encode.h"
#include "coap_option.h"
#include "pdu.h"
 
#ifndef COAP_MAX_BLOCK_SZX
#define COAP_MAX_BLOCK_SZX      6
#endif /* COAP_MAX_BLOCK_SZX */
 
typedef struct {
  unsigned int num;       
  unsigned int m:1;       
  unsigned int szx:3;     
} coap_block_t;
 
typedef struct {
  unsigned int num;       
  unsigned int m:1;       
  unsigned int szx:3;     
  unsigned int aszx:3;    
  unsigned int defined:1; 
  unsigned int bert:1;    
  uint32_t chunk_size;    
} coap_block_b_t;
 
#define COAP_BLOCK_USE_LIBCOAP  0x01 /* Use libcoap to do block requests */
#define COAP_BLOCK_SINGLE_BODY  0x02 /* Deliver the data as a single body */
 
#define COAP_OPT_BLOCK_LAST(opt) \
  (coap_opt_length(opt) ? (coap_opt_value(opt) + (coap_opt_length(opt)-1)) : 0)
 
#define COAP_OPT_BLOCK_MORE(opt) \
  (coap_opt_length(opt) ? (*COAP_OPT_BLOCK_LAST(opt) & 0x08) : 0)
 
#define COAP_OPT_BLOCK_SZX(opt)  \
  (coap_opt_length(opt) ? (*COAP_OPT_BLOCK_LAST(opt) & 0x07) : 0)
 
unsigned int coap_opt_block_num(const coap_opt_t *block_opt);
 
COAP_STATIC_INLINE int
coap_more_blocks(size_t data_len, unsigned int num, uint16_t szx) {
  return ((num+1) << (szx + 4)) < data_len;
}
 
#if 0
COAP_STATIC_INLINE void
coap_opt_block_set_m(coap_opt_t *block_opt, int m) {
  if (m)
    *(coap_opt_value(block_opt) + (coap_opt_length(block_opt) - 1)) |= 0x08;
  else
    *(coap_opt_value(block_opt) + (coap_opt_length(block_opt) - 1)) &= ~0x08;
}
#endif
 
int coap_get_block(const coap_pdu_t *pdu, coap_option_num_t number,
                   coap_block_t *block);
 
 
int coap_get_block_b(const coap_session_t *session, const coap_pdu_t *pdu,
                     coap_option_num_t number, coap_block_b_t *block);
 
int coap_write_block_opt(coap_block_t *block,
                         coap_option_num_t number,
                         coap_pdu_t *pdu,
                         size_t data_length);
int coap_write_block_b_opt(coap_session_t *session,
                           coap_block_b_t *block,
                           coap_option_num_t number,
                           coap_pdu_t *pdu,
                           size_t data_length);
 
 
int coap_add_block(coap_pdu_t *pdu,
                   size_t len,
                   const uint8_t *data,
                   unsigned int block_num,
                   unsigned char block_szx);
 
int coap_add_block_b_data(coap_pdu_t *pdu, size_t len, const uint8_t *data,
                          coap_block_b_t *block);
 
coap_binary_t *
coap_block_build_body(coap_binary_t *body_data, size_t length,
                      const uint8_t *data, size_t offset, size_t total);
 
void
coap_add_data_blocked_response(const coap_pdu_t *request,
                               coap_pdu_t *response,
                               uint16_t media_type,
                               int maxage,
                               size_t length,
                               const uint8_t* data);
 
typedef void (*coap_release_large_data_t)(coap_session_t *session,
                                          void *app_ptr);
 
int coap_add_data_large_request(coap_session_t *session,
                                coap_pdu_t *pdu,
                                size_t length,
                                const uint8_t *data,
                                coap_release_large_data_t release_func,
                                void *app_ptr);
 
int
coap_add_data_large_response(coap_resource_t *resource,
                             coap_session_t *session,
                             const coap_pdu_t *request,
                             coap_pdu_t *response,
                             const coap_string_t *query,
                             uint16_t media_type,
                             int maxage,
                             uint64_t etag,
                             size_t length,
                             const uint8_t *data,
                             coap_release_large_data_t release_func,
                             void *app_ptr);
 
void coap_context_set_block_mode(coap_context_t *context,
                                  uint8_t block_mode);
 
int coap_cancel_observe(coap_session_t *session, coap_binary_t *token,
                    coap_pdu_type_t message_type);
 
#endif /* COAP_BLOCK_H_ */