#include "lwip/opt.h"
#include "lwip/pbuf.h"
#include "lwip/ip_addr.h"
#include "lwip/netif.h"
#include "lwip/ip.h"

Data Structures
struct	eth_addr

struct	eth_hdr
	Ethernet header. More...

struct	etharp_hdr
	the ARP message, see RFC 826 ("Packet format") More...

Macros
#define	ARP_REPLY 2

#define	ARP_REQUEST 1
	ARP message types (opcodes) More...

#define	ARP_TMR_INTERVAL 5000
	5 seconds period More...

#define	eth_addr_cmp(addr1, addr2) (memcmp((addr1)->addr, (addr2)->addr, ETHARP_HWADDR_LEN) == 0)

#define	ETHADDR16_COPY(src, dst) SMEMCPY(src, dst, ETHARP_HWADDR_LEN)
	MEMCPY-like macro to copy to/from struct eth_addr's that are no local variables and known to be 16-bit aligned within the protocol header. More...

#define	ETHADDR32_COPY(src, dst) SMEMCPY(src, dst, ETHARP_HWADDR_LEN)
	MEMCPY-like macro to copy to/from struct eth_addr's that are local variables or known to be 32-bit aligned within the protocol header. More...

#define	etharp_gratuitous(netif) etharp_request((netif), &(netif)->ip_addr)
	For Ethernet network interfaces, we might want to send "gratuitous ARP"; this is an ARP packet sent by a node in order to spontaneously cause other nodes to update an entry in their ARP cache. More...

#define	ETHARP_HWADDR_LEN 6

#define	etharp_init() /* Compatibility define, not init needed. */

#define	ETHTYPE_ARP 0x0806U

#define	ETHTYPE_IP 0x0800U

#define	ETHTYPE_PPPOE 0x8864U /* PPP Over Ethernet Session Stage */

#define	ETHTYPE_PPPOEDISC 0x8863U /* PPP Over Ethernet Discovery Stage */

#define	ETHTYPE_VLAN 0x8100U

#define	LWIP_ARP_FILTER_NETIF 0
	Define this to 1 and define LWIP_ARP_FILTER_NETIF_FN(pbuf, netif, type) to a filter function that returns the correct netif when using multiple netifs on one hardware interface where the netif's low-level receive routine cannot decide for the correct netif (e.g. More...

#define	SIZEOF_ETH_HDR (14 + ETH_PAD_SIZE)

#define	SIZEOF_ETHARP_HDR 28

#define	SIZEOF_ETHARP_PACKET (SIZEOF_ETH_HDR + SIZEOF_ETHARP_HDR)

Functions
void	etharp_cleanup_netif (struct netif *netif)
	Remove all ARP table entries of the specified netif. More...

s8_t	etharp_find_addr (struct netif netif, ip_addr_t ipaddr, struct eth_addr eth_ret, ip_addr_t ip_ret)
	Finds (stable) ethernet/IP address pair from ARP table using interface and IP address index. More...

err_t	etharp_output (struct netif netif, struct pbuf q, ip_addr_t *ipaddr)
	Resolve and fill-in Ethernet address header for outgoing IP packet. More...

err_t	etharp_query (struct netif netif, ip_addr_t ipaddr, struct pbuf *q)
	Send an ARP request for the given IP address and/or queue a packet. More...

err_t	etharp_request (struct netif netif, ip_addr_t ipaddr)
	Send an ARP request packet asking for ipaddr. More...

void	etharp_tmr (void)
	Clears expired entries in the ARP table. More...

err_t	ethernet_input (struct pbuf p, struct netif netif)
	Process received ethernet frames. More...

Variables
struct eth_addr ethbroadcast	ethzero

PACK_STRUCT_BEGIN struct eth_addr	PACK_STRUCT_STRUCT

#define ARP_REPLY 2

Referenced by etharp_arp_input().

#define ARP_REQUEST 1

ARP message types (opcodes)

Referenced by etharp_arp_input(), and etharp_request().

#define ARP_TMR_INTERVAL 5000

5 seconds period

Referenced by arp_timer(), and sys_timeouts_init().

#define eth_addr_cmp	(	addr1,
		addr2
	)	(memcmp((addr1)->addr, (addr2)->addr, ETHARP_HWADDR_LEN) == 0)

Referenced by ethernet_input().

#define ETHADDR16_COPY	(	src,
		dst
	)	SMEMCPY(src, dst, ETHARP_HWADDR_LEN)

MEMCPY-like macro to copy to/from struct eth_addr's that are no local variables and known to be 16-bit aligned within the protocol header.

Referenced by etharp_arp_input(), etharp_raw(), and etharp_send_ip().

#define ETHADDR32_COPY	(	src,
		dst
	)	SMEMCPY(src, dst, ETHARP_HWADDR_LEN)

MEMCPY-like macro to copy to/from struct eth_addr's that are local variables or known to be 32-bit aligned within the protocol header.

Referenced by etharp_send_ip(), and etharp_update_arp_entry().

#define etharp_gratuitous ( netif ) etharp_request((netif), &(netif)->ip_addr)

For Ethernet network interfaces, we might want to send "gratuitous ARP"; this is an ARP packet sent by a node in order to spontaneously cause other nodes to update an entry in their ARP cache.

From RFC 3220 "IP Mobility Support for IPv4" section 4.6.

Referenced by netif_set_link_up(), and netif_set_up().

#define ETHARP_HWADDR_LEN 6

Referenced by etharp_arp_input(), etharp_raw(), etharp_send_ip(), and etharp_update_arp_entry().

#define etharp_init ( ) /* Compatibility define, not init needed. */

Referenced by lwip_init().

#define ETHTYPE_ARP 0x0806U

Referenced by etharp_raw(), ethernet_input(), and ethernetif_input().

#define ETHTYPE_IP 0x0800U

Referenced by etharp_arp_input(), etharp_raw(), etharp_send_ip(), ethernet_input(), and ethernetif_input().

#define ETHTYPE_PPPOE 0x8864U /* PPP Over Ethernet Session Stage */

Referenced by ethernet_input(), and ethernetif_input().

#define ETHTYPE_PPPOEDISC 0x8863U /* PPP Over Ethernet Discovery Stage */

Referenced by ethernet_input(), and ethernetif_input().

#define ETHTYPE_VLAN 0x8100U

Referenced by etharp_arp_input(), and ethernet_input().

#define LWIP_ARP_FILTER_NETIF 0

Define this to 1 and define LWIP_ARP_FILTER_NETIF_FN(pbuf, netif, type) to a filter function that returns the correct netif when using multiple netifs on one hardware interface where the netif's low-level receive routine cannot decide for the correct netif (e.g.

when mapping multiple IP addresses to one hardware interface).

#define SIZEOF_ETH_HDR (14 + ETH_PAD_SIZE)

Referenced by etharp_arp_input(), etharp_raw(), and ethernet_input().

#define SIZEOF_ETHARP_HDR 28

#define SIZEOF_ETHARP_PACKET (SIZEOF_ETH_HDR + SIZEOF_ETHARP_HDR)

Referenced by etharp_arp_input(), and etharp_raw().

void etharp_cleanup_netif ( struct netif * netif )

Remove all ARP table entries of the specified netif.

Parameters

netif points to a network interface

References arp_table, etharp_free_entry(), ETHARP_STATE_EMPTY, etharp_entry::state, and netif::state.

Referenced by netif_set_down().

s8_t etharp_find_addr	(	struct netif *	netif,
		ip_addr_t *	ipaddr,
		struct eth_addr **	eth_ret,
		ip_addr_t **	ip_ret
	)

Finds (stable) ethernet/IP address pair from ARP table using interface and IP address index.

Note: the addresses in the ARP table are in network order!

Parameters

netif	points to interface index
ipaddr	points to the (network order) IP address index
eth_ret	points to return pointer
ip_ret	points to return pointer

Returns: table index if found, -1 otherwise

References arp_table, etharp_entry::ethaddr, etharp_find_entry(), ETHARP_FLAG_FIND_ONLY, ETHARP_STATE_STABLE, etharp_entry::ipaddr, LWIP_ASSERT, LWIP_UNUSED_ARG, NULL, and netif::state.

err_t etharp_output	(	struct netif *	netif,
		struct pbuf *	q,
		ip_addr_t *	ipaddr
	)

Resolve and fill-in Ethernet address header for outgoing IP packet.

For IP multicast and broadcast, corresponding Ethernet addresses are selected and the packet is transmitted on the link.

For unicast addresses, the packet is submitted to etharp_query(). In case the IP address is outside the local network, the IP address of the gateway is used.

Parameters

netif	The lwIP network interface which the IP packet will be sent on.
q	The pbuf(s) containing the IP packet to be sent.
ipaddr	The IP address of the packet destination.

Returns

ERR_RTE No route to destination (no gateway to external networks), or the return type of either etharp_query() or etharp_send_ip().

References arp_table, ERR_BUF, ERR_RTE, etharp_cached_entry, ETHARP_DEBUG, etharp_output_to_arp_index(), etharp_query(), etharp_send_ip(), ETHARP_SET_HINT, ETHARP_STATE_STABLE, ETHARP_STATS_INC, netif::gw, netif::hwaddr, ip4_addr2, ip4_addr3, ip4_addr4, netif::ip_addr, ip_addr_cmp, ip_addr_isany, ip_addr_isbroadcast, ip_addr_islinklocal, ip_addr_ismulticast, ip_addr_netcmp, LINK_STATS_INC, LL_MULTICAST_ADDR_0, LL_MULTICAST_ADDR_1, LL_MULTICAST_ADDR_2, LWIP_ASSERT, LWIP_DBG_LEVEL_SERIOUS, LWIP_DBG_TRACE, LWIP_DEBUGF, netif::netmask, NULL, pbuf::payload, and pbuf_header().

Referenced by ethernetif_init().

err_t etharp_query	(	struct netif *	netif,
		ip_addr_t *	ipaddr,
		struct pbuf *	q
	)

Send an ARP request for the given IP address and/or queue a packet.

If the IP address was not yet in the cache, a pending ARP cache entry is added and an ARP request is sent for the given address. The packet is queued on this entry.

If the IP address was already pending in the cache, a new ARP request is sent for the given address. The packet is queued on this entry.

If the IP address was already stable in the cache, and a packet is given, it is directly sent and no ARP request is sent out.

If the IP address was already stable in the cache, and no packet is given, an ARP request is sent out.

Parameters

netif	The lwIP network interface on which ipaddr must be queried for.
ipaddr	The IP address to be resolved.
q	If non-NULL, a pbuf that must be delivered to the IP address. q is not freed by this function.

Note: q must only be ONE packet, not a packet queue!

Returns

ERR_BUF Could not make room for Ethernet header.
ERR_MEM Hardware address unknown, and no more ARP entries available to query for address or queue the packet.
ERR_MEM Could not queue packet due to memory shortage.
ERR_RTE No route to destination (no gateway to external networks).
ERR_ARG Non-unicast address given, those will not appear in ARP cache.

References arp_table, ERR_ARG, ERR_MEM, ERR_OK, ETHARP_DEBUG, etharp_find_entry(), ETHARP_FLAG_TRY_HARD, etharp_request(), etharp_send_ip(), ETHARP_SET_HINT, ETHARP_STATE_EMPTY, ETHARP_STATE_PENDING, ETHARP_STATE_STABLE, ETHARP_STATS_INC, netif::hwaddr, if(), ip_addr_isany, ip_addr_isbroadcast, ip_addr_ismulticast, pbuf::len, LWIP_ASSERT, LWIP_DBG_TRACE, LWIP_DEBUGF, memp_malloc(), pbuf::next, NULL, pbuf_alloc(), pbuf_copy(), pbuf_free(), PBUF_RAM, PBUF_RAW, pbuf_ref(), PBUF_ROM, etharp_entry::q, S16_F, etharp_entry::state, pbuf::tot_len, and pbuf::type.

Referenced by dhcp_check(), and etharp_output().

err_t etharp_request	(	struct netif *	netif,
		ip_addr_t *	ipaddr
	)

Send an ARP request packet asking for ipaddr.

Parameters

netif	the lwip network interface on which to send the request
ipaddr	the IP address for which to ask

Returns: ERR_OK if the request has been sent ERR_MEM if the ARP packet couldn't be allocated any other err_t on failure

References ARP_REQUEST, ETHARP_DEBUG, etharp_raw(), netif::hwaddr, netif::ip_addr, LWIP_DBG_TRACE, and LWIP_DEBUGF.

Referenced by etharp_output_to_arp_index(), and etharp_query().

void etharp_tmr ( void )

Clears expired entries in the ARP table.

This function should be called every ETHARP_TMR_INTERVAL milliseconds (5 seconds), in order to expire entries in the ARP table.

References ARP_MAXAGE, ARP_MAXPENDING, arp_table, etharp_entry::ctime, ETHARP_DEBUG, etharp_free_entry(), ETHARP_STATE_EMPTY, ETHARP_STATE_PENDING, ETHARP_STATE_STABLE, ETHARP_STATE_STABLE_REREQUESTING, LWIP_DEBUGF, etharp_entry::state, and U16_F.

Referenced by arp_timer().

err_t ethernet_input	(	struct pbuf *	p,
		struct netif *	netif
	)

Process received ethernet frames.

Using this function instead of directly calling ip_input and passing ARP frames through etharp in ethernetif_input, the ARP cache is protected from concurrent access.

Parameters

p	the recevied packet, p->payload pointing to the ethernet header
netif	the network interface on which the packet was received

References ERR_OK, eth_addr_cmp, etharp_arp_input(), ETHARP_DEBUG, ETHARP_STATS_INC, ETHTYPE_ARP, ETHTYPE_IP, ETHTYPE_PPPOE, ETHTYPE_PPPOEDISC, ETHTYPE_VLAN, pbuf::flags, netif::flags, htons, netif::hwaddr, ip_input(), pbuf::len, LL_MULTICAST_ADDR_0, LL_MULTICAST_ADDR_1, LL_MULTICAST_ADDR_2, LWIP_ASSERT, LWIP_DBG_TRACE, LWIP_DEBUGF, NETIF_FLAG_ETHARP, pbuf::payload, PBUF_FLAG_LLBCAST, PBUF_FLAG_LLMCAST, pbuf_free(), pbuf_header(), PP_HTONS, SIZEOF_ETH_HDR, and X8_F.

Referenced by tcpip_input(), and tcpip_thread().

struct eth_addr ethbroadcast ethzero

Referenced by etharp_free_entry().

PACK_STRUCT_BEGIN struct etharp_hdr PACK_STRUCT_STRUCT

Microchip® Advanced Software Framework

Data Structures

Macros

Functions

Variables