RE: [Patch bpf v3 8/8] skmsg: increase sk->sk_drops when dropping packets
From: John Fastabend <john.fastabend@gmail.com>
Date: 2021-05-28 05:27:49
Also in:
bpf
Cong Wang wrote:
From: Cong Wang <redacted> It is hard to observe packet drops without increasing relevant drop counters, here we should increase sk->sk_drops which is a protocol-independent counter. Fortunately psock is always associated with a struct sock, we can just use psock->sk. Suggested-by: John Fastabend <john.fastabend@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Jakub Sitnicki <jakub@cloudflare.com> Cc: Lorenz Bauer <redacted> Signed-off-by: Cong Wang <redacted> --- net/core/skmsg.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-)
[...]
quoted hunk ↗ jump to hunk
@@ -942,7 +948,7 @@ static int sk_psock_verdict_apply(struct sk_psock *psock, struct sk_buff *skb, case __SK_DROP: default: out_free: - kfree_skb(skb); + sock_drop(psock->sk, skb);
I must have missed this on first review. Why should we mark a packet we intentionally drop as sk_drops? I think we should leave it as just kfree_skb() this way sk_drops is just the error cases and if users want this counter they can always add it to the bpf prog itself.
} return err;