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: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Wojciech Drewek 2022-09-08 10:16:41 -07:00 committed by Paolo Abeni
parent 65b32f801b
commit dda2fa08a1
2 changed files with 37 additions and 0 deletions

View File

@ -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,
};

View File

@ -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 @@ ip_proto_again:
__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;