ARP

API for the Address Resolution Protocol More...

Functions
int	net_arp_init (void)
	Init ARP.
void	net_arp_shutdown (void)
	Shutdown ARP.
int	net_arp_insert (netif_t *nif, const uint8 mac[6], const uint8 ip[4], uint64 timestamp)
	Add an entry to the ARP cache manually.
int	net_arp_lookup (netif_t *nif, const uint8 ip_in[4], uint8 mac_out[6], const ip_hdr_t *pkt, const uint8 *data, int data_size)
	Look up an entry from the ARP cache.
int	net_arp_revlookup (netif_t *nif, uint8 ip_out[4], const uint8 mac_in[6])
	Do a reverse ARP lookup.
int	net_arp_input (netif_t *nif, const uint8 *pkt, int len)
	Receive an ARP packet and process it (called by net_input).
int	net_arp_query (netif_t *nif, const uint8 ip[4])
	Generate an ARP who-has query on the given device.

Detailed Description

API for the Address Resolution Protocol

Function Documentation

net_arp_init()

int net_arp_init

(

void

)

Init ARP.

Return values

0	On success (no error conditions defined).

net_arp_input()

int net_arp_input	(	netif_t *	nif,
		const uint8 *	pkt,
		int	len )

Receive an ARP packet and process it (called by net_input).

Parameters

nif	The network device in use.
pkt	The packet received.
len	The length of the packet.

Return values

0	On success (no error conditions defined).

net_arp_insert()

int net_arp_insert	(	netif_t *	nif,
		const uint8	mac[6],
		const uint8	ip[4],
		uint64	timestamp )

Add an entry to the ARP cache manually.

Parameters

nif	The network device in use.
mac	The MAC address of the entry.
ip	The IPv4 address of the entry.
timestamp	The entry's timestamp. Set to 0 for a permanent entry, otherwise set to the current number of milliseconds since boot (i.e, timer_ms_gettime64()).

Return values

0	On success.
-1	Error allocating memory.

net_arp_lookup()

int net_arp_lookup	(	netif_t *	nif,
		const uint8	ip_in[4],
		uint8	mac_out[6],
		const ip_hdr_t *	pkt,
		const uint8 *	data,
		int	data_size )

Look up an entry from the ARP cache.

If no entry is found, then an ARP query will be sent and an error will be returned. If you specify a packet with the call, it will be sent when the reply comes in.

Parameters

nif	The network device in use.
ip_in	The IP address to lookup.
mac_out	Storage for the MAC address, if found.
pkt	A simple IPv4 header, if you want to send one when a response comes in (if not found immediately).
data	Packet data to go with the header.
data_size	The size of data.

Return values

0	On success.
-1	A query is outstanding for that address.
-2	Address not found, query generated.
-3	Error allocating memory.

net_arp_query()

int net_arp_query	(	netif_t *	nif,
		const uint8	ip[4] )

Generate an ARP who-has query on the given device.

Parameters

nif	The network device to use.
ip	The IP to query.

Return values

0	On success (no error conditions defined).

net_arp_revlookup()

int net_arp_revlookup	(	netif_t *	nif,
		uint8	ip_out[4],
		const uint8	mac_in[6] )

Do a reverse ARP lookup.

This function looks for an IP for a given mac address; note that if this fails, you have no recourse.

Parameters

nif	The network device in use.
ip_out	Storage for the IPv4 address.
mac_in	The MAC address to look up.

Return values

0	On success.
-1	On failure.

net_arp_shutdown()

void net_arp_shutdown

(

void

)

Shutdown ARP.