@@ -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__ */
@@ -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);