[PATCH v4 net-next 5/7] net: ipv4: use kfree_skb_reason() in ip_protocol_deliver_rcu()

[menglong8.dong@gmail.com]

From: Menglong Dong <imagedong@tencent.com>

Replace kfree_skb() with kfree_skb_reason() in ip_protocol_deliver_rcu().
Following new drop reasons are introduced:

SKB_DROP_REASON_XFRM_POLICY
SKB_DROP_REASON_IP_NOPROTO

Signed-off-by: Menglong Dong <imagedong@tencent.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
---
v2:
- add document for the introduced drop reasons
---
 include/linux/skbuff.h     | 2 ++
 include/trace/events/skb.h | 2 ++
 net/ipv4/ip_input.c        | 5 +++--
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 4baba45f223d..2a64afa97910 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -339,6 +339,8 @@ enum skb_drop_reason {
 						  * is multicast, but L3 is
 						  * unicast.
 						  */
+	SKB_DROP_REASON_XFRM_POLICY,	/* xfrm policy check failed */
+	SKB_DROP_REASON_IP_NOPROTO,	/* no support for IP protocol */
 	SKB_DROP_REASON_MAX,
 };
 
diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h
index 485a1d3034a4..985e481c092d 100644
--- a/include/trace/events/skb.h
+++ b/include/trace/events/skb.h
@@ -23,6 +23,8 @@
 	EM(SKB_DROP_REASON_IP_RPFILTER, IP_RPFILTER)		\
 	EM(SKB_DROP_REASON_UNICAST_IN_L2_MULTICAST,		\
 	   UNICAST_IN_L2_MULTICAST)				\
+	EM(SKB_DROP_REASON_XFRM_POLICY, XFRM_POLICY)		\
+	EM(SKB_DROP_REASON_IP_NOPROTO, IP_NOPROTO)		\
 	EMe(SKB_DROP_REASON_MAX, MAX)
 
 #undef EM
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index d5222c0fa87c..d94f9f7e60c3 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -196,7 +196,8 @@ void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int protocol)
 	if (ipprot) {
 		if (!ipprot->no_policy) {
 			if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
-				kfree_skb(skb);
+				kfree_skb_reason(skb,
+						 SKB_DROP_REASON_XFRM_POLICY);
 				return;
 			}
 			nf_reset_ct(skb);
@@ -215,7 +216,7 @@ void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int protocol)
 				icmp_send(skb, ICMP_DEST_UNREACH,
 					  ICMP_PROT_UNREACH, 0);
 			}
-			kfree_skb(skb);
+			kfree_skb_reason(skb, SKB_DROP_REASON_IP_NOPROTO);
 		} else {
 			__IP_INC_STATS(net, IPSTATS_MIB_INDELIVERS);
 			consume_skb(skb);
-- 
2.34.1