Rime buffer management

The packetbuf module does Rime's buffer management. More...

Files
file	packetbuf.c
	Rime buffer (packetbuf) management
file	packetbuf.h
	Header file for the Rime buffer (packetbuf) management

Macros
#define	PACKETBUF_SIZE   128
	The size of the packetbuf, in bytes.
#define	PACKETBUF_HDR_SIZE   48
	The size of the packetbuf header, in bytes.

Functions
void	packetbuf_clear (void)
	Clear and reset the packetbuf. More...
void	packetbuf_clear_hdr (void)
	Clear and reset the header of the packetbuf. More...
int	packetbuf_copyfrom (const void *from, uint16_t len)
	Copy from external data into the packetbuf. More...
void	packetbuf_compact (void)
	Compact the packetbuf. More...
int	packetbuf_copyto_hdr (uint8_t *to)
	Copy the header portion of the packetbuf to an external buffer. More...
int	packetbuf_copyto (void *to)
	Copy the entire packetbuf to an external buffer. More...
int	packetbuf_hdralloc (int size)
	Extend the header of the packetbuf, for outbound packets. More...
int	packetbuf_hdrreduce (int size)
	Reduce the header in the packetbuf, for incoming packets. More...
void	packetbuf_set_datalen (uint16_t len)
	Set the length of the data in the packetbuf. More...
void *	packetbuf_dataptr (void)
	Get a pointer to the data in the packetbuf. More...
void *	packetbuf_hdrptr (void)
	Get a pointer to the header in the packetbuf, for outbound packets. More...
void	packetbuf_reference (void *ptr, uint16_t len)
	Point the packetbuf to external data. More...
int	packetbuf_is_reference (void)
	Check if the packetbuf references external data. More...
void *	packetbuf_reference_ptr (void)
	Get a pointer to external data referenced by the packetbuf. More...
uint16_t	packetbuf_datalen (void)
	Get the length of the data in the packetbuf. More...
uint8_t	packetbuf_hdrlen (void)
	Get the length of the header in the packetbuf, for outbound packets. More...
uint16_t	packetbuf_totlen (void)
	Get the total length of the header and data in the packetbuf. More...

Detailed Description

The packetbuf module does Rime's buffer management.

Function Documentation

void packetbuf_clear

(

void

)

Clear and reset the packetbuf.

This function clears the packetbuf and resets all internal state pointers (header size, header pointer, external data pointer). It is used before preparing a packet in the packetbuf.

Examples:

example-collect.c.

Definition at line 78 of file packetbuf.c.

References PACKETBUF_HDR_SIZE.

Referenced by dtn_network_get_buffer(), main(), packetbuf_copyfrom(), and packetbuf_reference().

void packetbuf_clear_hdr

(

void

)

Clear and reset the header of the packetbuf.

This function clears the header of the packetbuf and resets all the internal state pointers pertaining to the header (header size, header pointer, but not external data pointer). It is used before after sending a packet in the packetbuf, to be able to reuse the packet buffer for a later retransmission.

Definition at line 88 of file packetbuf.c.

References PACKETBUF_HDR_SIZE.

void packetbuf_compact

(

void

)

Compact the packetbuf.

This function compacts the packetbuf by copying the data portion of the packetbuf so that becomes consecutive to the header. It also copies external data that has previously been referenced with packetbuf_reference() into the packetbuf.

This function is called by the Rime code before a packet is to be sent by a device driver. This assures that the entire packet is consecutive in memory.

Definition at line 106 of file packetbuf.c.

References packetbuf_datalen(), PACKETBUF_HDR_SIZE, packetbuf_is_reference(), and packetbuf_reference_ptr().

int packetbuf_copyfrom	(	const void *	from,
		uint16_t	len
	)

Copy from external data into the packetbuf.

Parameters

from	A pointer to the data from which to copy
len	The size of the data to copy

Return values

The	number of bytes that was copied into the packetbuf This function copies data from a pointer into the packetbuf. If the data that is to be copied is larger than the packetbuf, only the data that fits in the packetbuf is copied. The number of bytes that could be copied into the rimbuf is returned.

Examples:

example-broadcast.c, example-mesh.c, example-multihop.c, example-runicast.c, example-trickle.c, and example-unicast.c.

Definition at line 94 of file packetbuf.c.

References packetbuf_clear(), and PACKETBUF_SIZE.

int packetbuf_copyto

(

void *

to

)

Copy the entire packetbuf to an external buffer.

Parameters

to	A pointer to the buffer to which the data is to be copied

Return values

The

number of bytes that was copied to the external buffer This function copies the packetbuf to an external buffer. Both the data portion and the header portion of the packetbuf is copied. If the packetbuf referenced external data (referenced with packetbuf_reference()) the external data is copied. The external buffer to which the packetbuf is to be copied must be able to accomodate at least (PACKETBUF_SIZE + PACKETBUF_HDR_SIZE) bytes. The number of bytes that was copied to the external buffer is returned.

Definition at line 141 of file packetbuf.c.

References PACKETBUF_HDR_SIZE, and PACKETBUF_SIZE.

int packetbuf_copyto_hdr

(

uint8_t *

to

)

Copy the header portion of the packetbuf to an external buffer.

Parameters

to	A pointer to the buffer to which the data is to be copied

Return values

The

number of bytes that was copied to the external buffer This function copies the header portion of the packetbuf to an external buffer. The external buffer to which the packetbuf is to be copied must be able to accomodate at least PACKETBUF_HDR_SIZE bytes. The number of bytes that was copied to the external buffer is returned.

Definition at line 124 of file packetbuf.c.

References PACKETBUF_HDR_SIZE.

uint16_t packetbuf_datalen

(

void

)

Get the length of the data in the packetbuf.

Returns

Length of the data in the packetbuf

        For outbound packets, the packetbuf consists of two
        parts: header and data. This function is used to get
        the length of the data in the packetbuf. The data is
        stored in the packetbuf and accessed via the
        packetbuf_dataptr() function.

        For incoming packets, both the packet header and the
        packet data is stored in the data portion of the
        packetbuf. This function is then used to get the total
        length of the packet - both header and data.

Examples:

example-collect.c, example-mesh.c, and example-unicast.c.

Definition at line 240 of file packetbuf.c.

Referenced by packetbuf_compact(), packetbuf_totlen(), and sicslowmac_dataRequest().

void * packetbuf_dataptr

(

void

)

Get a pointer to the data in the packetbuf.

Returns

Pointer to the packetbuf data

        This function is used to get a pointer to the data in
        the packetbuf. The data is either stored in the packetbuf,
        or referenced to an external location.

        For outbound packets, the packetbuf consists of two
        parts: header and data. The header is accessed with the
        packetbuf_hdrptr() function.

        For incoming packets, both the packet header and the
        packet data is stored in the data portion of the
        packetbuf. Thus this function is used to get a pointer to
        the header for incoming packets.

Examples:

example-broadcast.c, example-collect.c, example-mesh.c, example-multihop.c, example-trickle.c, and example-unicast.c.

Definition at line 208 of file packetbuf.c.

References PACKETBUF_HDR_SIZE.

Referenced by dtn_network_get_buffer(), main(), and sicslowmac_dataRequest().

int packetbuf_hdralloc

(

int

size

)

Extend the header of the packetbuf, for outbound packets.

Parameters

size	The number of bytes the header should be extended

Return values

Non-zero

if the header could be extended, zero otherwise This function is used to allocate extra space in the header portion in the packetbuf, when preparing outbound packets for transmission. If the function is unable to allocate sufficient header space, the function returns zero and does not allocate anything.

Definition at line 173 of file packetbuf.c.

References PACKETBUF_SIZE, and packetbuf_totlen().

uint8_t packetbuf_hdrlen

(

void

)

Get the length of the header in the packetbuf, for outbound packets.

Returns

Length of the header in the packetbuf

        For outbound packets, the packetbuf consists of two
        parts: header and data. This function is used to get
        the length of the header in the packetbuf. The header is
        stored in the packetbuf and accessed via the
        packetbuf_hdrptr() function.

Definition at line 246 of file packetbuf.c.

References PACKETBUF_HDR_SIZE.

Referenced by packetbuf_totlen().

void * packetbuf_hdrptr

(

void

)

Get a pointer to the header in the packetbuf, for outbound packets.

Returns

Pointer to the packetbuf header

        For outbound packets, the packetbuf consists of two
        parts: header and data. This function is used to get a
        pointer to the header in the packetbuf. The header is
        stored in the packetbuf.

Definition at line 214 of file packetbuf.c.

Referenced by main().

int packetbuf_hdrreduce

(

int

size

)

Reduce the header in the packetbuf, for incoming packets.

Parameters

size	The number of bytes the header should be reduced

Return values

Non-zero

if the header could be reduced, zero otherwise This function is used to remove the first part of the header in the packetbuf, when processing incoming packets. If the function is unable to remove the requested amount of header space, the function returns zero and does not allocate anything.

Definition at line 189 of file packetbuf.c.

int packetbuf_is_reference

(

void

)

Check if the packetbuf references external data.

Return values

Non-zero

if the packetbuf references external data, zero otherwise. For outbound packets, the packetbuf consists of two parts: header and data. This function is used to check if the packetbuf points to external data that has previously been referenced with packetbuf_reference().

Definition at line 228 of file packetbuf.c.

References PACKETBUF_HDR_SIZE.

Referenced by packetbuf_compact().

void packetbuf_reference	(	void *	ptr,
		uint16_t	len
	)

Point the packetbuf to external data.

Parameters

ptr	A pointer to the external data
len	The length of the external data For outbound packets, the packetbuf consists of two parts: header and data. This function is used to make the packetbuf point to external data. The function also specifies the length of the external data that the packetbuf references.

Definition at line 220 of file packetbuf.c.

References packetbuf_clear().

void * packetbuf_reference_ptr

(

void

)

Get a pointer to external data referenced by the packetbuf.

Return values

A	pointer to the external data For outbound packets, the packetbuf consists of two parts: header and data. The data may point to external data that has previously been referenced with packetbuf_reference(). This function is used to get a pointer to the external data.

Definition at line 234 of file packetbuf.c.

Referenced by packetbuf_compact().

void packetbuf_set_datalen

(

uint16_t

len

)

Set the length of the data in the packetbuf.

Parameters

len	The length of the data For outbound packets, the packetbuf consists of two parts: header and data. This function is used to set the length of the data in the packetbuf.

Examples:

example-collect.c.

Definition at line 201 of file packetbuf.c.

Referenced by dtn_network_send(), and main().

uint16_t packetbuf_totlen

(

void

)

Get the total length of the header and data in the packetbuf.

Returns

Length of data and header in the packetbuf

Definition at line 252 of file packetbuf.c.

References packetbuf_datalen(), and packetbuf_hdrlen().

Referenced by packetbuf_hdralloc().