Cong Wang wrote:
> From: Cong Wang <cong.wang@xxxxxxxxxxxxx>
>
> Yucong noticed we can't poll() sockets in sockmap even when
> they are the destination sockets of redirections. This is
> because we never poll any psock queues in ->poll(), except
> for TCP. Now we can overwrite >sock_is_readable() and
> implement and invoke it for UDP and AF_UNIX sockets.
nit: instead of 'because we never poll any psock queue...' how about
'because we do not poll the psock queues in ->poll(), except
for TCP.'
>
> Reported-by: Yucong Sun <sunyucong@xxxxxxxxx>
> Cc: John Fastabend <john.fastabend@xxxxxxxxx>
> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> Cc: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
> Cc: Lorenz Bauer <lmb@xxxxxxxxxxxxxx>
> Signed-off-by: Cong Wang <cong.wang@xxxxxxxxxxxxx>
> ---
[...]
> static inline void sk_msg_check_to_free(struct sk_msg *msg, u32 i, u32 bytes)
> {
> diff --git a/net/core/skmsg.c b/net/core/skmsg.c
> index 2d6249b28928..93ae48581ad2 100644
> --- a/net/core/skmsg.c
> +++ b/net/core/skmsg.c
> @@ -474,6 +474,20 @@ int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg,
> }
> EXPORT_SYMBOL_GPL(sk_msg_recvmsg);
>
> +bool sk_msg_is_readable(struct sock *sk)
> +{
> + struct sk_psock *psock;
> + bool empty = true;
> +
> + psock = sk_psock_get_checked(sk);
We shouldn't need the checked version here right? We only get here because
we hooked the sk with the callbacks from *_bpf_rebuild_rpotos. Then we
can just use sk_psock() and save a few extra insns/branch.
> + if (IS_ERR_OR_NULL(psock))
> + return false;
> + empty = sk_psock_queue_empty(psock);
> + sk_psock_put(sk, psock);
> + return !empty;
> +}
> +EXPORT_SYMBOL_GPL(sk_msg_is_readable);
[...]
