Layer 3 - Address Resolution Protocol (ARP)

TCP/IP Illustrated Vol I - Chapter 4 - ARP RFC 826 More...

Collaboration diagram for Layer 3 - Address Resolution Protocol (ARP):

Data Structures
struct	arp_header
	An ARP header. More...

Macros
#define	ARP_PACKET_SIZE    (sizeof(struct ethernet_header) + sizeof(struct arp_header))
	The maximum total size of an ARP packet.

Enumerations
enum	arp_hw_type { ARP_HW_ETHERNET = 1 }
	The different accepted types of hardware addresses. More...
enum	arp_operation { ARP_REQUEST = 1 , ARP_REPLY = 2 }
	The different ARP operations. More...

Functions
static size_t	arp_header_size (struct arp_header *hdr)
	Compute the size of an ARP header. More...
error_t	arp_add (__be ipv4_t, mac_address_t)
	Add a new entry inside the ARP table. More...
const mac_address_t *	arp_get (__be ipv4_t)
	Retreive the MAC address associated with an IPv4 address. More...
error_t	arp_receive_packet (struct packet *)
	Handle a received ARP packet.
error_t	arp_send_packet (struct arp_header *)
	Send an ARP request/reply.

Detailed Description

Enumeration Type Documentation

arp_hw_type

enum arp_hw_type

Enumerator
ARP_HW_ETHERNET	Ethernet MAC address.

arp_operation

enum arp_operation

Enumerator
ARP_REQUEST	Request. Sent first to try and find a MAC address.
ARP_REPLY	Reply. Sent back to the sender if a match was found.

Function Documentation

arp_add()

error_t arp_add	(	__be	ipv4_t,
		mac_address_t	mac
	)

Parameters

ip	The IP address (in network order)
mac	The MAC address associated with the IP

arp_get()

const mac_address_t * arp_get

(

__be

ipv4_t

)

Parameters

ip	The IP address (in network order)

Returns

The MAC address, or NULL if the IP isn't inside the table

arp_header_size()

static size_t arp_header_size ( struct arp_header *  hdr )

inlinestatic

The ARP protocol header size is of variable length, always use this function instead of the usual sizeof(struct arp_header).