mip_field.c File Reference

#include "mip_field.h"
#include "mip_packet.h"
#include "mip_offsets.h"
#include "definitions/descriptors.h"
#include <assert.h>

Include dependency graph for mip_field.c:

Functions
void	mip_field_init (mip_field *field, uint8_t descriptor_set, uint8_t field_descriptor, const uint8_t *payload, uint8_t payload_length)
	Constructs a mip_field given the parameters. More...
uint8_t	mip_field_descriptor_set (const mip_field *field)
	Returns the descriptor set of the packet containing this field._. More...
uint8_t	mip_field_field_descriptor (const mip_field *field)
	Returns the field descriptor. More...
uint8_t	mip_field_payload_length (const mip_field *field)
	Returns the length of the payload. More...
const uint8_t *	mip_field_payload (const mip_field *field)
	Returns the payload pointer for the field data. More...
bool	mip_field_is_valid (const mip_field *field)
	Returns true if the field has a valid field descriptor. More...
void	mip_field_init_empty (mip_field *field)
	Initialize a mip_field struct to an invalid/empty state. More...
mip_field	mip_field_from_header_ptr (const uint8_t *header, uint8_t total_length, uint8_t descriptor_set)
	Constructs a mip_field from a pointer to the heaader. More...
mip_field	mip_field_first_from_packet (const mip_packet *packet)
	Extracts the first field from a MIP packet. More...
mip_field	mip_field_next_after (const mip_field *field)
	Gets the next field after the specified field._. More...
bool	mip_field_next (mip_field *field)
	Updates the mip_field to refer to the next field in a packet. More...
bool	mip_field_next_in_packet (mip_field *field, const mip_packet *packet)
	Iterates over all fields in a packet. More...

Function Documentation

mip_field_descriptor_set()

uint8_t mip_field_descriptor_set

(

const mip_field *

field

)

Returns the descriptor set of the packet containing this field._.

mip_field_field_descriptor()

uint8_t mip_field_field_descriptor

(

const mip_field *

field

)

Returns the field descriptor.

mip_field_first_from_packet()

mip_field mip_field_first_from_packet

(

const mip_packet *

packet

)

Extracts the first field from a MIP packet.

Typically this would be used as the first step when iterating through all fields in a received packet. To access each field after the first, call mip_field_next(). You should call mip_field_is_at_end() or mip_field_is_valid() after obtaining each field (including the first) to determine if the field is actually valid.

Parameters

packet

The mip packet containing 0 or more fields. Assumed to be valid, and the payload pointer and size must be correct.

Returns

A mip_field struct with the first field from the packet.

mip_field_from_header_ptr()

mip_field mip_field_from_header_ptr	(	const uint8_t *	header,
		uint8_t	total_length,
		uint8_t	descriptor_set
	)

Constructs a mip_field from a pointer to the heaader.

Generally you should use mip_field_from_packet() or mip_field_create() instead.

Parameters

header	A pointer to the header and payload. Usually inside of a MIP packet.
total_length	The total length of either the field or packet payload, starting from header_ptr and including the header bytes. If total_length is longer than the field (i.e. if it's the packet payload length) then mip_field_next() may be used to iterate fields.
descriptor_set	The descriptor set for the packet containing this field. May be 0x00 if not used by any function handling the field.

Returns

a mip_field struct with the field data.

mip_field_init()

void mip_field_init	(	mip_field *	field,
		uint8_t	descriptor_set,
		uint8_t	field_descriptor,
		const uint8_t *	payload,
		uint8_t	payload_length
	)

Constructs a mip_field given the parameters.

Parameters

field
descriptor_set	The MIP descriptor set of the packet.
field_descriptor	The MIP field descriptor.
payload	A pointer to a buffer containing the field payload, not including the field header. The data must exist while the field is in use. Can be NULL if payload_length is 0.
payload_length	The length of the payload. Cannot exceed MIP_FIELD_PAYLOAD_LENGTH_MAX.

Returns

A mip_field initialized with the specified values.

mip_field_init_empty()

void mip_field_init_empty

(

mip_field *

field

)

Initialize a mip_field struct to an invalid/empty state.

Intended to be used with mip_field_next_in_packet. The field will not be valid (mip_field_is_valid will return false).

Parameters

field

mip_field_is_valid()

bool mip_field_is_valid

(

const mip_field *

field

)

Returns true if the field has a valid field descriptor.

mip_field_next()

bool mip_field_next

(

mip_field *

field

)

Updates the mip_field to refer to the next field in a packet.

Parameters

field

This mip_field struct will be updated to the next field._ Can be an invalid field, in which case the result will be invalid as well.

Returns

true if the field exists and is valid.

mip_field_next_after()

mip_field mip_field_next_after

(

const mip_field *

field

)

Gets the next field after the specified field._.

Parameters

field

An existing MIP field in a packet. Can be invalid, in which case the result will also be invalid.

Returns

A mip_field struct referencing the next field after the input field._ Check mip_field_is_valid() to see if the field exists.

mip_field_next_in_packet()

bool mip_field_next_in_packet	(	mip_field *	field,
		const mip_packet *	packet
	)

Iterates over all fields in a packet.

Parameters

field	An initialized mip_field struct. This will be updated to the next field in the packet, if one exists. Otherwise it will be invalid.
packet	A valid MIP packet.

Returns

true if another field exists.

false if there are no more fields.

Example usage:

struct mip_field field;
mip_field_init_empty(&field);
while( mip_field_next_in_packet(&field, packet) )
{
  // Do something with the field.
}

mip_field_payload()

const uint8_t* mip_field_payload

(

const mip_field *

field

)

Returns the payload pointer for the field data.

mip_field_payload_length()

uint8_t mip_field_payload_length

(

const mip_field *

field

)

Returns the length of the payload.