From: Wojciech Drewek <wojciech.drewek@intel.com>
Date: Thu, 8 Sep 2022 10:16:41 -0700
Subject: flow_dissector: Add L2TPv3 dissectors
Patch-mainline: v6.1-rc1
Git-commit: dda2fa08a13c688bed320ef2e4ba541abb4d6c17
References: jsc#PED-376
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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
include/net/flow_dissector.h | 9 +++++++++
net/core/flow_dissector.c | 28 ++++++++++++++++++++++++++++
2 files changed, 37 insertions(+)
--- a/include/net/flow_dissector.h
+++ b/include/net/flow_dissector.h
@@ -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,
};
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -204,6 +204,30 @@ static void __skb_flow_dissect_icmp(cons
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)
@@ -1497,6 +1521,10 @@ 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;