This feature totally depends on transport, so if transport doesn't
support it, return error.
Signed-off-by: Arseniy Krasnov <avkrasnov@xxxxxxxxxxxxxxxxx>
Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
---
include/net/af_vsock.h | 7 +++++++
net/vmw_vsock/af_vsock.c | 6 ++++++
2 files changed, 13 insertions(+)
diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index b01cf9ac2437..e302c0e804d0 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 ****/
@@ -241,4 +244,8 @@ static inline void __init vsock_bpf_build_proto(void)
{}
#endif
+static inline bool vsock_msgzerocopy_allow(const struct vsock_transport *t)
+{
+ return t->msgzerocopy_allow && t->msgzerocopy_allow();
+}
#endif /* __AF_VSOCK_H__ */
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 38486efd3d05..71108b1f0dfc 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1824,6 +1824,12 @@ static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
goto out;
}
+ if (msg->msg_flags & MSG_ZEROCOPY &&
+ !vsock_msgzerocopy_allow(transport)) {
+ 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
