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Commit ac4bb5de authored by Jiri Pirko's avatar Jiri Pirko Committed by David S. Miller
Browse files

net: flow_dissector: add support for dissection of tcp flags 



Add support for dissection of tcp flags. Uses similar function call to
tcp dissection function as arp, mpls and others.

Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Acked-by: default avatarOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2a7f38c5

include/net/flow_dissector.h

+9 −0
Original line number Diff line number Diff line
@@ -157,6 +157,14 @@ struct flow_dissector_key_eth_addrs { 
	unsigned char src[ETH_ALEN];

};



/**

 * struct flow_dissector_key_tcp:

 * @flags: flags

 */

struct flow_dissector_key_tcp {

	__be16 flags;

};



enum flow_dissector_key_id {

	FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */

	FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
@@ -177,6 +185,7 @@ enum flow_dissector_key_id { 
	FLOW_DISSECTOR_KEY_ENC_CONTROL, /* struct flow_dissector_key_control */

	FLOW_DISSECTOR_KEY_ENC_PORTS, /* struct flow_dissector_key_ports */

	FLOW_DISSECTOR_KEY_MPLS, /* struct flow_dissector_key_mpls */

	FLOW_DISSECTOR_KEY_TCP, /* struct flow_dissector_key_tcp */



	FLOW_DISSECTOR_KEY_MAX,

};

net/core/flow_dissector.c

+29 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/stddef.h>

#include <linux/if_ether.h>

#include <linux/mpls.h>

#include <linux/tcp.h>

#include <net/flow_dissector.h>

#include <scsi/fc/fc_fcoe.h>
@@ -342,6 +343,30 @@ __skb_flow_dissect_gre(const struct sk_buff *skb, 
	return FLOW_DISSECT_RET_OUT_PROTO_AGAIN;

}



static void

__skb_flow_dissect_tcp(const struct sk_buff *skb,

		       struct flow_dissector *flow_dissector,

		       void *target_container, void *data, int thoff, int hlen)

{

	struct flow_dissector_key_tcp *key_tcp;

	struct tcphdr *th, _th;



	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))

		return;



	th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);

	if (!th)

		return;



	if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))

		return;



	key_tcp = skb_flow_dissector_target(flow_dissector,

					    FLOW_DISSECTOR_KEY_TCP,

					    target_container);

	key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));

}



/**

 * __skb_flow_dissect - extract the flow_keys struct and return it

 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
@@ -683,6 +708,10 @@ bool __skb_flow_dissect(const struct sk_buff *skb, 
	case IPPROTO_MPLS:

		proto = htons(ETH_P_MPLS_UC);

		goto mpls;

	case IPPROTO_TCP:

		__skb_flow_dissect_tcp(skb, flow_dissector, target_container,

				       data, nhoff, hlen);

		break;

	default:

		break;

	}