[RFC PATCH net-next v2 2/5] flow_dissector: Add L2TPv3 dissectors
From: Wojciech Drewek <hidden>
Date: 2022-08-29 09:47:39
Also in:
intel-wired-lan
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Allow to dissect L2TPv3 specific field which is: - session ID (32 bits) L2TPv3 might be transported over IP or over UDP, this ipmplementation is only about L2TPv3 over IP. IP protocold carries L2TPv3 when ip_proto is IPPROTO_L2TP (115). Signed-off-by: Wojciech Drewek <redacted> --- include/net/flow_dissector.h | 9 +++++++++ net/core/flow_dissector.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 37 insertions(+)
diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
index 6c74812d64b2..5ccf52ef8809 100644
--- 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, };
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 764c4cb3fe8f..dbd944de4129 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c@@ -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; + + hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); + if (!hdr) + return; + + if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_L2TPV3)) + 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 @@ 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;
--
2.31.1