Commit bec21719 authored by Liu Jian's avatar Liu Jian Committed by Daniel Borkmann
Browse files

skmsg: Schedule psock work if the cached skb exists on the psock 



In sk_psock_backlog function, for ingress direction skb, if no new data
packet arrives after the skb is cached, the cached skb does not have a
chance to be added to the receive queue of psock. As a result, the cached
skb cannot be received by the upper-layer application. Fix this by reschedule
the psock work to dispose the cached skb in sk_msg_recvmsg function.

Fixes: 604326b4 ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: default avatarLiu Jian <liujian56@huawei.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220907071311.60534-1-liujian56@huawei.com
parent 043a7356

net/core/skmsg.c

+8 −4
Original line number Diff line number Diff line
@@ -434,8 +434,10 @@ int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg, 
			if (copied + copy > len)

				copy = len - copied;

			copy = copy_page_to_iter(page, sge->offset, copy, iter);

			if (!copy)

				return copied ? copied : -EFAULT;

			if (!copy) {

				copied = copied ? copied : -EFAULT;

				goto out;

			}



			copied += copy;

			if (likely(!peek)) {
@@ -455,7 +457,7 @@ int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg, 
				 * didn't copy the entire length lets just break.

				 */

				if (copy != sge->length)

					return copied;

					goto out;

				sk_msg_iter_var_next(i);

			}
@@ -477,7 +479,9 @@ int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg, 
		}

		msg_rx = sk_psock_peek_msg(psock);

	}



out:

	if (psock->work_state.skb && copied > 0)

		schedule_work(&psock->work);

	return copied;

}

EXPORT_SYMBOL_GPL(sk_msg_recvmsg);