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
501  * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev)
503  * RFC3069 supports proxy arp replies back to the same interface.  This
542  *	Create an arp packet. If dest_hw is not set, we create a broadcast
552 	struct arphdr *arp;
567 	arp = skb_put(skb, arp_hdr_len(dev));
582 	 * Fill out the arp protocol part.
584 	 * The arp hardware type should match the device type, except for FDDI,
593 		arp->ar_hrd = htons(dev->type);
594 		arp->ar_pro = htons(ETH_P_IP);
599 		arp->ar_hrd = htons(ARPHRD_AX25);
600 		arp->ar_pro = htons(AX25_P_IP);
605 		arp->ar_hrd = htons(ARPHRD_NETROM);
606 		arp->ar_pro = htons(AX25_P_IP);
613 		arp->ar_hrd = htons(ARPHRD_ETHER);
614 		arp->ar_pro = htons(ETH_P_IP);
619 	arp->ar_hln = dev->addr_len;
620 	arp->ar_pln = 4;
621 	arp->ar_op = htons(type);
623 	arp_ptr = (unsigned char *)(arp + 1);
658  *	Send an arp packet.
696  *	Process an arp request.
703 	struct arphdr *arp;
722 	arp = arp_hdr(skb);
726 		if (arp->ar_pro != htons(ETH_P_IP) ||
727 		    htons(dev_type) != arp->ar_hrd)
742 		if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
743 		     arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
744 		    arp->ar_pro != htons(ETH_P_IP))
748 		if (arp->ar_pro != htons(AX25_P_IP) ||
749 		    arp->ar_hrd != htons(ARPHRD_AX25))
753 		if (arp->ar_pro != htons(AX25_P_IP) ||
754 		    arp->ar_hrd != htons(ARPHRD_NETROM))
761 	if (arp->ar_op != htons(ARPOP_REPLY) &&
762 	    arp->ar_op != htons(ARPOP_REQUEST))
768 	arp_ptr = (unsigned char *)(arp + 1);
818  *  and in the case of requests for us we add the requester to the arp
822 	if (arp->ar_op == htons(ARPOP_REQUEST) && skb_metadata_dst(skb))
829 		if (arp->ar_op == htons(ARPOP_REQUEST) &&
837 	if (arp->ar_op == htons(ARPOP_REQUEST) &&
893 		is_garp = arp_is_garp(net, dev, &addr_type, arp->ar_op,
904 		     (arp->ar_op == htons(ARPOP_REPLY) &&
920 		   arp trashing and chooses the fastest router.
930 		if (arp->ar_op != htons(ARPOP_REPLY) ||
961  *	Receive an arp request from the device layer.
967 	const struct arphdr *arp;
983 	arp = arp_hdr(skb);
984 	if (arp->ar_hln != dev->addr_len || arp->ar_pln != 4)
1477 	/* Don't want to confuse "arp -a" w/ magic entries,
1493 	if (!proc_create_net("arp", 0444, net->proc_net, &arp_seq_ops,
1501 	remove_proc_entry("arp", net->proc_net);