Packet

Collaboration diagram for Packet:

Data Structures
struct	packet
	A network packet. More...

Macros
#define	packet_put_literal(packet, data)   packet_put(packet, &data, sizeof(data))
	Append new data of literal type to the packet (e.g. More...
#define	packet_peek_literal(packet, data)    packet_peek(packet, &data, sizeof(data))
	Read literal from the packet (e.g. More...
#define	packet_pop_literal(packet, data)   packet_pop(packet, &data, sizeof(data))
	Pop literal from the packet (e.g. More...

Functions
struct packet *	packet_new (size_t packet_size)
	Create a new packet.
struct packet *	packet_clone (const struct packet *packet)
	Clone a packet. More...
void	packet_free (struct packet *packet)
	Free a packet.
error_t	packet_send (struct packet *packet)
	Send the packet.
static void *	packet_start (const struct packet *packet)
	Find the start of the actual packet's content.
static size_t	packet_size (const struct packet *packet)
static size_t	packet_read_size (const struct packet *packet)
static void *	packet_end (const struct packet *packet)
	Find the end of the actual packet's content.
error_t	packet_put (struct packet *packet, const void *data, size_t size)
	Append new data to the packet.
size_t	packet_peek (struct packet *packet, void *data, size_t size)
	Read data from the packet. More...
size_t	packet_pop (struct packet *packet, void *data, size_t size)
	Read data from the packet. More...
static void	packet_mark_l2_start (struct packet *packet)
	Set the current end of the packet as the start of the link layer.
static void	packet_set_l2_size (struct packet *packet, size_t size)
	Set the start of the network layer N bytes after the link layer.
static void	packet_mark_l3_start (struct packet *packet)
	Set the current end of the packet as the start of the network layer.
static void	packet_set_l3_size (struct packet *packet, size_t size)
	Set the start of the packet payload N bytes after the network layer.
static void *	packet_payload (const struct packet *packet)
static size_t	packet_header_size (const struct packet *packet)
static size_t	packet_payload_size (const struct packet *packet)

Detailed Description

Network Packet

The network packet is the core of the network API. Each time we send or receive a packet, a new packet is created to hold its data and be passed to the API's function.

This packet's design is inspired by Linux's socket buffer interface. Even though this is a heavily simplified version of it, the philosophy remains the same:

• The packet's content is hidden after its metadata struct
• changes to the packet can only be done incrementally (similar to a stack)

Macro Definition Documentation

packet_peek_literal

#define packet_peek_literal	(		packet,
			data
	)		packet_peek(packet, &data, sizeof(data))

integers)

packet_pop_literal

#define packet_pop_literal	(		packet,
			data
	)		packet_pop(packet, &data, sizeof(data))

integers)

packet_put_literal

#define packet_put_literal	(		packet,
			data
	)		packet_put(packet, &data, sizeof(data))

integers)

Function Documentation

packet_clone()

struct packet * packet_clone

(

const struct packet *

packet

)

The packet's content as well as the current offsets will be duplicated, so that one can use a duplicated packet just like the original one.

packet_header_size()

static size_t packet_header_size ( const struct packet *  packet )

inlinestatic

Returns

the size of the packet's header

packet_payload()

static void * packet_payload ( const struct packet *  packet )

inlinestatic

Returns

the sart of the packet's payload (L4)

packet_payload_size()

static size_t packet_payload_size ( const struct packet *  packet )

inlinestatic

Returns

the size of the packet's payload

packet_peek()

size_t packet_peek	(	struct packet *	packet,
		void *	data,
		size_t	size
	)

Returns

The number of bytes actually read.

packet_pop()

size_t packet_pop	(	struct packet *	packet,
		void *	data,
		size_t	size
	)

Popped data cannot be re-read afterwards.

Returns

The number of bytes actually read.

packet_read_size()

static size_t packet_read_size ( const struct packet *  packet )

inlinestatic

Returns

The current number of bytes that can be read from the packet

packet_size()

static size_t packet_size ( const struct packet *  packet )

inlinestatic

Returns

The current number of bytes placed into the packet