Messages in this thread Patch in this message | | | Date | Wed, 27 Jul 2022 14:24:17 +0200 | From | Stefano Garzarella <> | Subject | Re: [RFC PATCH v2 5/9] vsock: SO_RCVLOWAT transport set callback |
| |
On Mon, Jul 25, 2022 at 08:05:28AM +0000, Arseniy Krasnov wrote: >This adds transport specific callback for SO_RCVLOWAT, because in some >transports it may be difficult to know current available number of bytes >ready to read. Thus, when SO_RCVLOWAT is set, transport may reject it. > >Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru> >--- > include/net/af_vsock.h | 1 + > net/vmw_vsock/af_vsock.c | 19 +++++++++++++++++++ > 2 files changed, 20 insertions(+) > >diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h >index f742e50207fb..eae5874bae35 100644 >--- a/include/net/af_vsock.h >+++ b/include/net/af_vsock.h >@@ -134,6 +134,7 @@ struct vsock_transport { > u64 (*stream_rcvhiwat)(struct vsock_sock *); > bool (*stream_is_active)(struct vsock_sock *); > bool (*stream_allow)(u32 cid, u32 port); >+ int (*set_rcvlowat)(struct vsock_sock *, int); > > /* SEQ_PACKET. */ > ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg, >diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c >index 63a13fa2686a..b7a286db4af1 100644 >--- a/net/vmw_vsock/af_vsock.c >+++ b/net/vmw_vsock/af_vsock.c >@@ -2130,6 +2130,24 @@ vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, > return err; > } > >+static int vsock_set_rcvlowat(struct sock *sk, int val) >+{ >+ const struct vsock_transport *transport; >+ struct vsock_sock *vsk; >+ int err = 0; >+ >+ vsk = vsock_sk(sk); >+ transport = vsk->transport;
`transport` can be NULL if the user call SO_RCVLOWAT before we assign it, so we should check it.
I think if the transport implements `set_rcvlowat`, maybe we should set there sk->sk_rcvlowat, so I would do something like that:
if (transport && transport->set_rcvlowat) err = transport->set_rcvlowat(vsk, val); else WRITE_ONCE(sk->sk_rcvlowat, val ? : 1); return err;
In addition I think we should check that val does not exceed vsk->buffer_size, something similar of what tcp_set_rcvlowat() does.
Thanks, Stefano
| |