[PATCH net-next v3 2/3] net: icmp: introduce __ping_queue_rcv_skb() to report drop reasons

From: menglong8 . dong
Date: Wed Mar 16 2022 - 02:32:55 EST


From: Menglong Dong <imagedong@xxxxxxxxxxx>

In order to avoid to change the return value of ping_queue_rcv_skb(),
introduce the function __ping_queue_rcv_skb(), which is able to report
the reasons of skb drop as its return value, as Paolo suggested.

Meanwhile, make ping_queue_rcv_skb() a simple call to
__ping_queue_rcv_skb().

The kfree_skb() and sock_queue_rcv_skb() used in ping_queue_rcv_skb()
are replaced with kfree_skb_reason() and sock_queue_rcv_skb_reason()
now.

Reviewed-by: Hao Peng <flyingpeng@xxxxxxxxxxx>
Reviewed-by: Jiang Biao <benbjiang@xxxxxxxxxxx>
Signed-off-by: Menglong Dong <imagedong@xxxxxxxxxxx>
---
v3:
- fix aligenment problem

v2:
- introduce __ping_queue_rcv_skb() instead of change the return value
of ping_queue_rcv_skb()
---
net/ipv4/ping.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 3ee947557b88..9a1ea6c263f8 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -934,16 +934,24 @@ int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
}
EXPORT_SYMBOL_GPL(ping_recvmsg);

-int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+static enum skb_drop_reason __ping_queue_rcv_skb(struct sock *sk,
+ struct sk_buff *skb)
{
+ enum skb_drop_reason reason;
+
pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
inet_sk(sk), inet_sk(sk)->inet_num, skb);
- if (sock_queue_rcv_skb(sk, skb) < 0) {
- kfree_skb(skb);
+ if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) {
+ kfree_skb_reason(skb, reason);
pr_debug("ping_queue_rcv_skb -> failed\n");
- return -1;
+ return reason;
}
- return 0;
+ return SKB_NOT_DROPPED_YET;
+}
+
+int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+ return __ping_queue_rcv_skb(sk, skb) ?: -1;
}
EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);

--
2.35.1