Forwarder helper

Some helper functions used by the forwarder. More...

Collaboration diagram for Forwarder helper:

Data Structures
struct	interest_options
	Interest options which the forwarder cares. More...

Typedefs
typedef struct interest_options	interest_options_t
	Interest options which the forwarder cares. More...

Functions
size_t	tlv_get_tlvar (uint8_t *buf, size_t buflen, uint32_t *var)
	Get the first variable of type or length from a TLV encoded form. More...
uint8_t *	tlv_get_type_length (uint8_t *buf, size_t buflen, uint32_t *type, uint32_t *length)
	Get type and length from a TLV encoded form. More...
int	tlv_check_type_length (uint8_t *buf, size_t buflen, uint32_t type)
	Check the type and length of a TLV block. More...
int	tlv_interest_get_header (uint8_t *interest, size_t buflen, interest_options_t *options, uint8_t **name, size_t *name_len)
	Get the name and options of an Interest packet. More...
int	tlv_data_get_name (uint8_t *data, size_t buflen, uint8_t **name, size_t *name_len)
	Get the name of a Data packet. More...
uint8_t *	tlv_interest_get_hoplimit_ptr (uint8_t *interest, size_t buflen)
	Get the pointer to hop limit field of a Interest packet. More...
uint64_t	tlv_get_uint (uint8_t *buf, size_t buflen)
	Decode an unsigned integer value. More...

Detailed Description

Some helper functions used by the forwarder.

Typedef Documentation

interest_options_t

typedef struct interest_options interest_options_t

Interest options which the forwarder cares.

Currently only used in the forwarder.

Function Documentation

tlv_check_type_length()

int tlv_check_type_length	(	uint8_t *	buf,
		size_t	buflen,
		uint32_t	type
	)

Check the type and length of a TLV block.

Parameters

[in]	buf	[Optional] The buffer containing the TLV block.
[in]	buflen	The length of buf.
[in]	type	The required type.

Return values

NDN_SUCCESS	The check succeeds.
NDN_INVALID_POINTER	The buf is NULL.
NDN_OVERSIZE_VAR	Either type of length in buf is truncated or malicious.
NDN_WRONG_TLV_TYPE	The type of buf is different from type.
NDN_WRONG_TLV_LENGTH	The length of buf is different from length.

Note

This function will kindly check buf != NULL.

tlv_data_get_name()

int tlv_data_get_name	(	uint8_t *	data,
		size_t	buflen,
		uint8_t **	name,
		size_t *	name_len
	)

Get the name of a Data packet.

Parameters

[in]	data	The Data packet.
[in]	buflen	The length of data.
[out]	name	A pointer to the name in data.
[out]	name_len	The length of name.

Return values

NDN_SUCCESS	The operation succeeds.
NDN_OVERSIZE_VAR	Either type of length in buf is truncated or malicious.
NDN_WRONG_TLV_TYPE	The type of buf is not TLV_Data.
NDN_WRONG_TLV_LENGTH	The length of buf is different from length.
NDN_UNSUPPORTED_FORMAT	The first element of interest is not TLV_Name.

tlv_get_tlvar()

size_t tlv_get_tlvar	(	uint8_t *	buf,
		size_t	buflen,
		uint32_t *	var
	)

Get the first variable of type or length from a TLV encoded form.

Parameters

[in]	buf	The buffer containing the TLV encoded form.
[in]	buflen	The length of buf.
[out]	var	The decoded value.

Returns

If the function succeeds, return the size var takes. If the function fails, return 0.

tlv_get_type_length()

uint8_t* tlv_get_type_length	(	uint8_t *	buf,
		size_t	buflen,
		uint32_t *	type,
		uint32_t *	length
	)

Get type and length from a TLV encoded form.

Parameters

[in]	buf	The buffer containing the TLV encoded form.
[in]	buflen	The length of buf.
[out]	type	The decoded type.
[out]	length	The decoded length.

Returns

If the function succeeds, return a pointer to its content. If the function fails, return NULL.

tlv_get_uint()

uint64_t tlv_get_uint	(	uint8_t *	buf,
		size_t	buflen
	)

Decode an unsigned integer value.

Parameters

[in]	buf	Buffer pointing to the value, not including T and L.
[in]	buflen	The length of buf.

Returns

The value.

tlv_interest_get_header()

int tlv_interest_get_header	(	uint8_t *	interest,
		size_t	buflen,
		interest_options_t *	options,
		uint8_t **	name,
		size_t *	name_len
	)

Get the name and options of an Interest packet.

Parameters

[in]	interest	The Interest packet.
[in]	buflen	The length of interest.
[out]	options	[Optional] Options of interest.
[out]	name	A pointer to the name in interest.
[out]	name_len	The length of name.

Return values

NDN_SUCCESS	The operation succeeds.
NDN_OVERSIZE_VAR	Either type of length in buf is truncated or malicious.
NDN_WRONG_TLV_TYPE	The type of buf is not TLV_Interest.
NDN_WRONG_TLV_LENGTH	The length of buf is different from length.
NDN_UNSUPPORTED_FORMAT	The first element of interest is not TLV_Name.

tlv_interest_get_hoplimit_ptr()

uint8_t* tlv_interest_get_hoplimit_ptr	(	uint8_t *	interest,
		size_t	buflen
	)

Get the pointer to hop limit field of a Interest packet.

Parameters

[in]	interest	The Interest packet.
[in]	buflen	The length of interest.

Returns

If the function succeeds, return a pointer to the hop limit. If interest doesn't contain a hop limit field, return NULL.

Precondition

tlv_interest_get_header should succeed for interest.