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Subject: [PATCH net-next 7/7] net: dev: use kfree_skb_reason() for __netif_receive_skb_core()
Date:   Fri,  4 Mar 2022 01:47:07 +0800
Message-Id: <20220303174707.40431-8-imagedong@tencent.com>
In-Reply-To: <20220303174707.40431-1-imagedong@tencent.com>
References: <20220303174707.40431-1-imagedong@tencent.com>
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From: Menglong Dong <imagedong@tencent.com>

Add reason for skb drops to __netif_receive_skb_core() when packet_type
not found to handle the skb. For this purpose, the drop reason
SKB_DROP_REASON_PTYPE_ABSENT is introduced. Take ether packets for
example, this case mainly happens when L3 protocol is not supported.

Signed-off-by: Menglong Dong <imagedong@tencent.com>
---
 include/linux/skbuff.h | 5 +++++
 net/core/dev.c         | 8 +++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 04508d15152e..f3945d21cecf 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -413,6 +413,11 @@ enum skb_drop_reason {
 					 * failed (maybe an eBPF program
 					 * is tricking?)
 					 */
+	SKB_DROP_REASON_PTYPE_ABSENT,	/* not packet_type found to handle
+					 * the skb. For an etner packet,
+					 * this means that L3 protocol is
+					 * not supported
+					 */
 	SKB_DROP_REASON_MAX,
 };
 
diff --git a/net/core/dev.c b/net/core/dev.c
index 429ad8265e8c..0bdea7d113f5 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5330,11 +5330,13 @@ static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
 		*ppt_prev = pt_prev;
 	} else {
 drop:
-		if (!deliver_exact)
+		if (!deliver_exact) {
 			atomic_long_inc(&skb->dev->rx_dropped);
-		else
+			kfree_skb_reason(skb, SKB_DROP_REASON_PTYPE_ABSENT);
+		} else {
 			atomic_long_inc(&skb->dev->rx_nohandler);
-		kfree_skb(skb);
+			kfree_skb(skb);
+		}
 		/* Jamal, now you will not able to escape explaining
 		 * me how you were going to use this. :-)
 		 */
-- 
2.35.1