Commit 781dd043 authored by Cong Wang's avatar Cong Wang Committed by Daniel Borkmann
Browse files

skmsg: Increase sk->sk_drops when dropping packets 



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: default avatarJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: default avatarCong Wang <cong.wang@bytedance.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Acked-by: default avatarJakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210615021342.7416-9-xiyou.wangcong@gmail.com
parent 42830571

net/core/skmsg.c

+14 −8
Original line number Diff line number Diff line
@@ -578,6 +578,12 @@ static int sk_psock_handle_skb(struct sk_psock *psock, struct sk_buff *skb, 
	return sk_psock_skb_ingress(psock, skb);

}



static void sock_drop(struct sock *sk, struct sk_buff *skb)

{

	sk_drops_add(sk, skb);

	kfree_skb(skb);

}



static void sk_psock_backlog(struct work_struct *work)

{

	struct sk_psock *psock = container_of(work, struct sk_psock, work);
@@ -617,7 +623,7 @@ static void sk_psock_backlog(struct work_struct *work) 
				/* Hard errors break pipe and stop xmit. */

				sk_psock_report_error(psock, ret ? -ret : EPIPE);

				sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED);

				kfree_skb(skb);

				sock_drop(psock->sk, skb);

				goto end;

			}

			off += ret;
@@ -708,7 +714,7 @@ static void __sk_psock_zap_ingress(struct sk_psock *psock) 


	while ((skb = skb_dequeue(&psock->ingress_skb)) != NULL) {

		skb_bpf_redirect_clear(skb);

		kfree_skb(skb);

		sock_drop(psock->sk, skb);

	}

	__sk_psock_purge_ingress_msg(psock);

}
@@ -834,7 +840,7 @@ static int sk_psock_skb_redirect(struct sk_psock *from, struct sk_buff *skb) 
	 * return code, but then didn't set a redirect interface.

	 */

	if (unlikely(!sk_other)) {

		kfree_skb(skb);

		sock_drop(from->sk, skb);

		return -EIO;

	}

	psock_other = sk_psock(sk_other);
@@ -844,14 +850,14 @@ static int sk_psock_skb_redirect(struct sk_psock *from, struct sk_buff *skb) 
	 */

	if (!psock_other || sock_flag(sk_other, SOCK_DEAD)) {

		skb_bpf_redirect_clear(skb);

		kfree_skb(skb);

		sock_drop(from->sk, skb);

		return -EIO;

	}

	spin_lock_bh(&psock_other->ingress_lock);

	if (!sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED)) {

		spin_unlock_bh(&psock_other->ingress_lock);

		skb_bpf_redirect_clear(skb);

		kfree_skb(skb);

		sock_drop(from->sk, skb);

		return -EIO;

	}
@@ -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);

	}



	return err;
@@ -977,7 +983,7 @@ static void sk_psock_strp_read(struct strparser *strp, struct sk_buff *skb) 
	sk = strp->sk;

	psock = sk_psock(sk);

	if (unlikely(!psock)) {

		kfree_skb(skb);

		sock_drop(sk, skb);

		goto out;

	}

	prog = READ_ONCE(psock->progs.stream_verdict);
@@ -1098,7 +1104,7 @@ static int sk_psock_verdict_recv(read_descriptor_t *desc, struct sk_buff *skb, 
	psock = sk_psock(sk);

	if (unlikely(!psock)) {

		len = 0;

		kfree_skb(skb);

		sock_drop(sk, skb);

		goto out;

	}

	prog = READ_ONCE(psock->progs.stream_verdict);