option.h File Reference

helpers for handling options in CoAP PDUs More...

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

Go to the source code of this file.

Data Structures
struct	coap_option_t
	Representation of CoAP options. More...
struct	coap_opt_iterator_t
	Iterator to run through PDU options. More...

Macros
#define	PCHAR(p)   ((coap_opt_t *)(p))
#define	COAP_OPT_SIZE(opt)   coap_opt_size(opt)
#define	options_next(opt)
	Interprets opt as pointer to a CoAP option and advances to the next byte past this option. More...
#define	COAP_OPT_ALL   NULL
	Pre-defined filter that includes all options. More...
#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)
#define	COAP_OPT_LENGTH(opt)   coap_opt_length(opt)
#define	COAP_OPT_VALUE(opt)   coap_opt_value((coap_opt_t *)opt)

Typedefs
typedef unsigned char	coap_opt_t
	Use byte-oriented access methods here because sliding a complex struct coap_opt_t over the data buffer may cause bus error on certain platforms. More...
typedef unsigned char	coap_opt_filter_t [(COAP_MAX_OPT >> 3)+1]
	Fixed-size bit-vector we use for option filtering. More...

Functions
size_t	coap_opt_parse (const coap_opt_t *opt, size_t length, coap_option_t *result)
	Parses the option pointed to by opt into result. More...
size_t	coap_opt_size (const coap_opt_t *opt)
	Returns the size of the given option, taking into account a possible option jump. More...
coap_opt_t *	options_start (coap_pdu_t *pdu)
	Calculates the beginning of the PDU's option section. More...
static void	coap_option_filter_clear (coap_opt_filter_t f)
	Clears filter f. More...
static int	coap_option_setb (coap_opt_filter_t filter, unsigned short type)
	Sets the corresponding bit for type in filter. More...
static int	coap_option_clrb (coap_opt_filter_t filter, unsigned short type)
	Clears the corresponding bit for type in filter. More...
static int	coap_option_getb (const coap_opt_filter_t filter, unsigned short type)
	Gets the corresponding bit for type in filter. More...
coap_opt_iterator_t *	coap_option_iterator_init (coap_pdu_t *pdu, coap_opt_iterator_t *oi, const coap_opt_filter_t filter)
	Initializes the given option iterator oi to point to the beginning of the pdu's option list. More...
coap_opt_t *	coap_option_next (coap_opt_iterator_t *oi)
	Updates the iterator oi to point to the next option. More...
coap_opt_t *	coap_check_option (coap_pdu_t *pdu, unsigned char type, coap_opt_iterator_t *oi)
	Retrieves the first option of type type from pdu. More...
size_t	coap_opt_setheader (coap_opt_t *opt, size_t maxlen, unsigned short delta, size_t length)
	Encodes the given delta and length values into opt. More...
size_t	coap_opt_encode (coap_opt_t *opt, size_t n, unsigned short delta, const unsigned char *val, size_t length)
	Encodes option with given delta into opt. More...
unsigned short	coap_opt_delta (const coap_opt_t *opt)
	Decodes the delta value of the next option. More...
unsigned short	coap_opt_length (const coap_opt_t *opt)
	Returns the length of the given option. More...
unsigned char *	coap_opt_value (coap_opt_t *opt)
	Returns a pointer to the value of the given option. More...

Detailed Description

helpers for handling options in CoAP PDUs

Definition in file option.h.

Macro Definition Documentation

#define COAP_OPT_SIZE

(

opt

)

coap_opt_size(opt)

Deprecated:

{ Use coap_opt_size() instead. }

Definition at line 65 of file option.h.

#define options_next

(

opt

)

Interprets opt as pointer to a CoAP option and advances to the next byte past this option.

Definition at line 80 of file option.h.

#define PCHAR

(

p

)

((coap_opt_t *)(p))

Definition at line 27 of file option.h.

Typedef Documentation

typedef unsigned char coap_opt_t

Use byte-oriented access methods here because sliding a complex struct coap_opt_t over the data buffer may cause bus error on certain platforms.

Definition at line 26 of file option.h.

Function Documentation

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

Parses the option pointed to by opt into result.

This function returns the number of bytes that have been parsed, or 0 on error. An error is signaled when illegal delta or length values are encountered or when option parsing would result in reading past the option (i.e. beyond opt + length).

Parameters

opt	The beginning of the option to parse.
length	The maximum length of opt.
result	A pointer to the coap_option_t structure that is filled with actual values iff coap_opt_parse() > 0.

Returns

The number of bytes parsed or 0 on error.

Definition at line 38 of file option.c.

size_t coap_opt_size

(

const coap_opt_t *

opt

)

Returns the size of the given option, taking into account a possible option jump.

Parameters

opt	An option jump or the beginning of the option.

Returns

The number of bytes between opt and the end of the option starting at opt. In case of an error, this function returns 0 as options need at least one byte storage space.

Definition at line 319 of file option.c.

coap_opt_t* options_start

(

coap_pdu_t *

pdu

)

Calculates the beginning of the PDU's option section.

Parameters

pdu	The PDU containing the options.

Returns

A pointer to the first option if available, or NULL otherwise.

Definition at line 24 of file option.c.