[PATCH v2 net-next 6/8] net: ipv4: use kfree_skb_reason() in ip_protocol_deliver_rcu()

From: menglong8 . dong
Date: Thu Jan 27 2022 - 04:14:33 EST


From: Menglong Dong <imagedong@xxxxxxxxxxx>

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@xxxxxxxxxxx>
---
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 2d712459d564..4e55321e2fc2 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 184decb1c8eb..74c090f6eb9d 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