[RFC PATCH v3 1/9] vsock: SO_RCVLOWAT transport set callback
From: Arseniy Krasnov <hidden>
Date: 2022-08-03 13:54:00
Also in:
kvm, lkml, netdev
Subsystem:
networking [general], the rest, vm sockets (af_vsock) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Stefano Garzarella
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 <redacted> --- include/net/af_vsock.h | 1 + net/vmw_vsock/af_vsock.c | 25 +++++++++++++++++++++++++ 2 files changed, 26 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 f04abf662ec6..016ad5ff78b7 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c@@ -2129,6 +2129,30 @@ 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); + + if (val > vsk->buffer_size) + return -EINVAL; + + transport = vsk->transport; + + if (!transport) + return -EOPNOTSUPP; + + if (transport->set_rcvlowat) + err = transport->set_rcvlowat(vsk, val); + else + WRITE_ONCE(sk->sk_rcvlowat, val ? : 1); + + return err; +} + static const struct proto_ops vsock_stream_ops = { .family = PF_VSOCK, .owner = THIS_MODULE,
@@ -2148,6 +2172,7 @@ static const struct proto_ops vsock_stream_ops = { .recvmsg = vsock_connectible_recvmsg, .mmap = sock_no_mmap, .sendpage = sock_no_sendpage, + .set_rcvlowat = vsock_set_rcvlowat, }; static const struct proto_ops vsock_seqpacket_ops = {
--
2.25.1