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Commit 55733350 authored by Simon Horman's avatar Simon Horman Committed by David S. Miller
Browse files

flow disector: ARP support 



Allow dissection of (R)ARP operation hardware and protocol addresses
for Ethernet hardware and IPv4 protocol addresses.

There are currently no users of FLOW_DISSECTOR_KEY_ARP.
A follow-up patch will allow FLOW_DISSECTOR_KEY_ARP to be used by the
flower classifier.

Signed-off-by: default avatarSimon Horman <simon.horman@netronome.com>
Acked-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 380043b9

include/net/flow_dissector.h

+19 −0
Original line number Diff line number Diff line
@@ -88,6 +88,24 @@ struct flow_dissector_key_addrs { 
	};

};



/**

 * flow_dissector_key_arp:

 *	@ports: Operation, source and target addresses for an ARP header

 *              for Ethernet hardware addresses and IPv4 protocol addresses

 *		sip: Sender IP address

 *		tip: Target IP address

 *		op:  Operation

 *		sha: Sender hardware address

 *		tpa: Target hardware address

 */

struct flow_dissector_key_arp {

	__u32 sip;

	__u32 tip;

	__u8 op;

	unsigned char sha[ETH_ALEN];

	unsigned char tha[ETH_ALEN];

};



/**

 * flow_dissector_key_tp_ports:

 *	@ports: port numbers of Transport header
@@ -141,6 +159,7 @@ enum flow_dissector_key_id { 
	FLOW_DISSECTOR_KEY_ICMP, /* struct flow_dissector_key_icmp */

	FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */

	FLOW_DISSECTOR_KEY_TIPC_ADDRS, /* struct flow_dissector_key_tipc_addrs */

	FLOW_DISSECTOR_KEY_ARP, /* struct flow_dissector_key_arp */

	FLOW_DISSECTOR_KEY_VLAN, /* struct flow_dissector_key_flow_vlan */

	FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_flow_tags */

	FLOW_DISSECTOR_KEY_GRE_KEYID, /* struct flow_dissector_key_keyid */

net/core/flow_dissector.c

+57 −0
Original line number Diff line number Diff line
@@ -138,6 +138,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb, 
	struct flow_dissector_key_control *key_control;

	struct flow_dissector_key_basic *key_basic;

	struct flow_dissector_key_addrs *key_addrs;

	struct flow_dissector_key_arp *key_arp;

	struct flow_dissector_key_ports *key_ports;

	struct flow_dissector_key_icmp *key_icmp;

	struct flow_dissector_key_tags *key_tags;
@@ -379,6 +380,62 @@ bool __skb_flow_dissect(const struct sk_buff *skb, 


		nhoff += FCOE_HEADER_LEN;

		goto out_good;



	case htons(ETH_P_ARP):

	case htons(ETH_P_RARP): {

		struct {

			unsigned char ar_sha[ETH_ALEN];

			unsigned char ar_sip[4];

			unsigned char ar_tha[ETH_ALEN];

			unsigned char ar_tip[4];

		} *arp_eth, _arp_eth;

		const struct arphdr *arp;

		struct arphdr *_arp;



		arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,

					   hlen, &_arp);

		if (!arp)

			goto out_bad;



		if (arp->ar_hrd != htons(ARPHRD_ETHER) ||

		    arp->ar_pro != htons(ETH_P_IP) ||

		    arp->ar_hln != ETH_ALEN ||

		    arp->ar_pln != 4 ||

		    (arp->ar_op != htons(ARPOP_REPLY) &&

		     arp->ar_op != htons(ARPOP_REQUEST)))

			goto out_bad;



		arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),

					       sizeof(_arp_eth), data,

					       hlen - sizeof(_arp),

					       &_arp_eth);

		if (!arp)

			goto out_bad;



		if (dissector_uses_key(flow_dissector,

				       FLOW_DISSECTOR_KEY_ARP)) {



			key_arp = skb_flow_dissector_target(flow_dissector,

							    FLOW_DISSECTOR_KEY_ARP,

							    target_container);



			memcpy(&key_arp->sip, arp_eth->ar_sip,

			       sizeof(key_arp->sip));

			memcpy(&key_arp->tip, arp_eth->ar_tip,

			       sizeof(key_arp->tip));



			/* Only store the lower byte of the opcode;

			 * this covers ARPOP_REPLY and ARPOP_REQUEST.

			 */

			key_arp->op = ntohs(arp->ar_op) & 0xff;



			ether_addr_copy(key_arp->sha, arp_eth->ar_sha);

			ether_addr_copy(key_arp->tha, arp_eth->ar_tha);

		}



		goto out_good;

	}



	default:

		goto out_bad;

	}