option.h

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/*
 * option.h -- helpers for handling options in CoAP PDUs
 *
 * Copyright (C) 2010-2013 Olaf Bergmann <bergmann@tzi.org>
 *
 * This file is part of the CoAP library libcoap. Please see
 * README for terms of use. 
 */

#ifndef _OPTION_H_
#define _OPTION_H_

#include "bits.h"
#include "pdu.h"

typedef unsigned char coap_opt_t;
#define PCHAR(p) ((coap_opt_t *)(p))

typedef struct {
  unsigned short delta;
  size_t length;
  unsigned char *value;
} coap_option_t;

size_t coap_opt_parse(const coap_opt_t *opt, size_t length, 
              coap_option_t *result);

size_t coap_opt_size(const coap_opt_t *opt);

#define COAP_OPT_SIZE(opt) coap_opt_size(opt)

coap_opt_t *options_start(coap_pdu_t *pdu);

#define options_next(opt) \
  ((coap_opt_t *)((unsigned char *)(opt) + COAP_OPT_SIZE(opt)))

typedef unsigned char coap_opt_filter_t[(COAP_MAX_OPT >> 3) + 1];

#define COAP_OPT_ALL NULL

static inline void
coap_option_filter_clear(coap_opt_filter_t f) {
  memset(f, 0, sizeof(coap_opt_filter_t));
}

inline static int
coap_option_setb(coap_opt_filter_t filter, unsigned short type) {
  return bits_setb((uint8_t *)filter, sizeof(coap_opt_filter_t), type);
}

inline static int
coap_option_clrb(coap_opt_filter_t filter, unsigned short type) {
  return bits_clrb((uint8_t *)filter, sizeof(coap_opt_filter_t), type);
}

inline static int
coap_option_getb(const coap_opt_filter_t filter, unsigned short type) {
  return bits_getb((uint8_t *)filter, sizeof(coap_opt_filter_t), type);
}

typedef struct {
  size_t length;        
  unsigned short type;      
  unsigned int bad:1;       
  unsigned int filtered:1;  
  coap_opt_t *next_option;  
  coap_opt_filter_t filter; 
} coap_opt_iterator_t;

coap_opt_iterator_t *coap_option_iterator_init(coap_pdu_t *pdu,
     coap_opt_iterator_t *oi, const coap_opt_filter_t filter);

coap_opt_t *coap_option_next(coap_opt_iterator_t *oi);

coap_opt_t *coap_check_option(coap_pdu_t *pdu, 
                  unsigned char type, 
                  coap_opt_iterator_t *oi);

size_t coap_opt_setheader(coap_opt_t *opt, size_t maxlen, 
              unsigned short delta, size_t length);

size_t coap_opt_encode(coap_opt_t *opt, size_t n, unsigned short delta,
               const unsigned char *val, size_t length);

unsigned short coap_opt_delta(const coap_opt_t *opt);

#define COAP_OPT_DELTA(opt) coap_opt_delta(opt)

#define COAP_OPT_SETDELTA(opt,val)          \
  coap_opt_encode((opt), COAP_MAX_PDU_SIZE, (val), NULL, 0)

unsigned short coap_opt_length(const coap_opt_t *opt);

#define COAP_OPT_LENGTH(opt) coap_opt_length(opt)

unsigned char *coap_opt_value(coap_opt_t *opt);

#define COAP_OPT_VALUE(opt) coap_opt_value((coap_opt_t *)opt)

#endif /* _OPTION_H_ */