tls: Allow MSG_SPLICE_PAGES but treat it as normal sendmsg

Allow MSG_SPLICE_PAGES to be specified to sendmsg() but treat it as normal
sendmsg for now.  This means the data will just be copied until
MSG_SPLICE_PAGES is handled.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Chuck Lever <chuck.lever@oracle.com>
cc: Boris Pismenny <borisp@nvidia.com>
cc: John Fastabend <john.fastabend@gmail.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/tls/tls_device.c

@@ -447,7 +447,8 @@ static int tls_push_data(struct sock *sk,
 	long timeo;
 
 	if (flags &
-	    ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_SENDPAGE_NOTLAST))
+	    ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_SENDPAGE_NOTLAST |
+	      MSG_SPLICE_PAGES))
 		return -EOPNOTSUPP;
 
 	if (unlikely(sk->sk_err))

net/tls/tls_sw.c

@@ -955,7 +955,7 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 	int pending;
 
 	if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
-			       MSG_CMSG_COMPAT))
+			       MSG_CMSG_COMPAT | MSG_SPLICE_PAGES))
 		return -EOPNOTSUPP;
 
 	ret = mutex_lock_interruptible(&tls_ctx->tx_lock);