Commit dda2fa08 authored by Wojciech Drewek's avatar Wojciech Drewek Committed by Paolo Abeni
Browse files

flow_dissector: Add L2TPv3 dissectors 



Allow to dissect L2TPv3 specific field which is:
- session ID (32 bits)

L2TPv3 might be transported over IP or over UDP,
this implementation is only about L2TPv3 over IP.
IP protocol carries L2TPv3 when ip_proto is
IPPROTO_L2TP (115).

Acked-by: default avatarGuillaume Nault <gnault@redhat.com>
Signed-off-by: default avatarWojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 65b32f80

include/net/flow_dissector.h

+9 −0
Original line number Diff line number Diff line
@@ -289,6 +289,14 @@ struct flow_dissector_key_pppoe { 
	__be16 type;

};



/**

 * struct flow_dissector_key_l2tpv3:

 * @session_id: identifier for a l2tp session

 */

struct flow_dissector_key_l2tpv3 {

	__be32 session_id;

};



enum flow_dissector_key_id {

	FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */

	FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
@@ -320,6 +328,7 @@ enum flow_dissector_key_id { 
	FLOW_DISSECTOR_KEY_HASH, /* struct flow_dissector_key_hash */

	FLOW_DISSECTOR_KEY_NUM_OF_VLANS, /* struct flow_dissector_key_num_of_vlans */

	FLOW_DISSECTOR_KEY_PPPOE, /* struct flow_dissector_key_pppoe */

	FLOW_DISSECTOR_KEY_L2TPV3, /* struct flow_dissector_key_l2tpv3 */



	FLOW_DISSECTOR_KEY_MAX,

};

net/core/flow_dissector.c

+28 −0
Original line number Diff line number Diff line
@@ -204,6 +204,30 @@ static void __skb_flow_dissect_icmp(const struct sk_buff *skb, 
	skb_flow_get_icmp_tci(skb, key_icmp, data, thoff, hlen);

}



static void __skb_flow_dissect_l2tpv3(const struct sk_buff *skb,

				      struct flow_dissector *flow_dissector,

				      void *target_container, const void *data,

				      int nhoff, int hlen)

{

	struct flow_dissector_key_l2tpv3 *key_l2tpv3;

	struct {

		__be32 session_id;

	} *hdr, _hdr;



	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_L2TPV3))

		return;



	hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);

	if (!hdr)

		return;



	key_l2tpv3 = skb_flow_dissector_target(flow_dissector,

					       FLOW_DISSECTOR_KEY_L2TPV3,

					       target_container);



	key_l2tpv3->session_id = hdr->session_id;

}



void skb_flow_dissect_meta(const struct sk_buff *skb,

			   struct flow_dissector *flow_dissector,

			   void *target_container)
@@ -1501,6 +1525,10 @@ bool __skb_flow_dissect(const struct net *net, 
		__skb_flow_dissect_icmp(skb, flow_dissector, target_container,

					data, nhoff, hlen);

		break;

	case IPPROTO_L2TP:

		__skb_flow_dissect_l2tpv3(skb, flow_dissector, target_container,

					  data, nhoff, hlen);

		break;



	default:

		break;