This feature totally depends on transport, so if transport doesn't
support it, return error.
Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
---
include/net/af_vsock.h | 3 +++
net/vmw_vsock/af_vsock.c | 7 +++++++
2 files changed, 10 insertions(+)
diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 0e7504a42925..270ca54cfab8 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -177,6 +177,9 @@ struct vsock_transport {
/* Read a single skb */
int (*read_skb)(struct vsock_sock *, skb_read_actor_t);
+
+ /* Zero-copy. */
+ bool (*msgzerocopy_allow)(void);
};
/**** CORE ****/
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index c50d2632a75f..eac8c1affd6a 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1824,6 +1824,13 @@ static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
goto out;
}
+ if (msg->msg_flags & MSG_ZEROCOPY &&
+ (!transport->msgzerocopy_allow ||
+ !transport->msgzerocopy_allow())) {
+ err = -EOPNOTSUPP;
+ goto out;
+ }
+
/* Wait for room in the produce queue to enqueue our user's data. */
timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
--
2.25.1
