net/ipv4/arp.c

2 /* linux/net/ipv4/arp.c
40  *					eg intelligent arp probing and
51  *		Stuart Cheshire	:	Metricom and grat arp fixes
60  *		Alexey Kuznetsov:	new arp state machine;
63  *		Arnaldo C. Melo :	convert /proc/net/arp to seq_file
109 #include <net/arp.h>
300 /* Create and send an arp packet. */
310 	/* arp on this interface. */
442 	case 2: /* Create a neighbor in the arp table only if sip
500  * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev)
502  * RFC3069 supports proxy arp replies back to the same interface.  This
541  *	Create an arp packet. If dest_hw is not set, we create a broadcast
551 	struct arphdr *arp;
566 	arp = skb_put(skb, arp_hdr_len(dev));
581 	 * Fill out the arp protocol part.
583 	 * The arp hardware type should match the device type, except for FDDI,
592 		arp->ar_hrd = htons(dev->type);
593 		arp->ar_pro = htons(ETH_P_IP);
598 		arp->ar_hrd = htons(ARPHRD_AX25);
599 		arp->ar_pro = htons(AX25_P_IP);
604 		arp->ar_hrd = htons(ARPHRD_NETROM);
605 		arp->ar_pro = htons(AX25_P_IP);
612 		arp->ar_hrd = htons(ARPHRD_ETHER);
613 		arp->ar_pro = htons(ETH_P_IP);
618 	arp->ar_hln = dev->addr_len;
619 	arp->ar_pln = 4;
620 	arp->ar_op = htons(type);
622 	arp_ptr = (unsigned char *)(arp + 1);
657  *	Send an arp packet.
695  *	Process an arp request.
702 	struct arphdr *arp;
721 	arp = arp_hdr(skb);
725 		if (arp->ar_pro != htons(ETH_P_IP) ||
726 		    htons(dev_type) != arp->ar_hrd)
741 		if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
742 		     arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
743 		    arp->ar_pro != htons(ETH_P_IP))
747 		if (arp->ar_pro != htons(AX25_P_IP) ||
748 		    arp->ar_hrd != htons(ARPHRD_AX25))
752 		if (arp->ar_pro != htons(AX25_P_IP) ||
753 		    arp->ar_hrd != htons(ARPHRD_NETROM))
760 	if (arp->ar_op != htons(ARPOP_REPLY) &&
761 	    arp->ar_op != htons(ARPOP_REQUEST))
767 	arp_ptr = (unsigned char *)(arp + 1);
817  *  and in the case of requests for us we add the requester to the arp
821 	if (arp->ar_op == htons(ARPOP_REQUEST) && skb_metadata_dst(skb))
828 		if (arp->ar_op == htons(ARPOP_REQUEST) &&
836 	if (arp->ar_op == htons(ARPOP_REQUEST) &&
892 		is_garp = arp_is_garp(net, dev, &addr_type, arp->ar_op,
903 		     (arp->ar_op == htons(ARPOP_REPLY) &&
919 		   arp trashing and chooses the fastest router.
929 		if (arp->ar_op != htons(ARPOP_REPLY) ||
960  *	Receive an arp request from the device layer.
966 	const struct arphdr *arp;
982 	arp = arp_hdr(skb);
983 	if (arp->ar_hln != dev->addr_len || arp->ar_pln != 4)
1431 	/* Don't want to confuse "arp -a" w/ magic entries,
1447 	if (!proc_create_net("arp", 0444, net->proc_net, &arp_seq_ops,
1455 	remove_proc_entry("arp", net->proc_net);