block.h

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/*
 * block.h -- block transfer
 *
 * Copyright (C) 2010-2012,2014-2015 Olaf Bergmann <bergmann@tzi.org>
 *
 * 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 "option.h"
#include "pdu.h"

struct coap_resource_t;
struct coap_session_t;

#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;

#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(coap_pdu_t *pdu, uint16_t type, coap_block_t *block);

int coap_write_block_opt(coap_block_t *block,
                         uint16_t type,
                         coap_pdu_t *pdu,
                         size_t data_length);

int coap_add_block(coap_pdu_t *pdu,
                   unsigned int len,
                   const uint8_t *data,
                   unsigned int block_num,
                   unsigned char block_szx);

void
coap_add_data_blocked_response(struct coap_resource_t *resource,
                               struct coap_session_t *session,
                               coap_pdu_t *request,
                               coap_pdu_t *response,
                               const coap_binary_t *token,
                               uint16_t media_type,
                               int maxage,
                               size_t length,
                               const uint8_t* data);

#endif /* COAP_BLOCK_H_ */