af_vsock: rest of SEQPACKET support

Add socket ops for SEQPACKET type and .seqpacket_allow() callback
to query transports if they support SEQPACKET. Also split path
for data check for STREAM and SEQPACKET branches.
Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/af_vsock.h

@@ -140,6 +140,8 @@ struct vsock_transport {
 				     int flags);
 	int (*seqpacket_enqueue)(struct vsock_sock *vsk, struct msghdr *msg,
 				 size_t len);
+	bool (*seqpacket_allow)(u32 remote_cid);
+	u32 (*seqpacket_has_data)(struct vsock_sock *vsk);
 
 	/* Notification. */
 	int (*notify_poll_in)(struct vsock_sock *, size_t, bool *);

net/vmw_vsock/af_vsock.c

@@ -452,6 +452,7 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
 		new_transport = transport_dgram;
 		break;
 	case SOCK_STREAM:
+	case SOCK_SEQPACKET:
 		if (vsock_use_local_transport(remote_cid))
 			new_transport = transport_local;
 		else if (remote_cid <= VMADDR_CID_HOST || !transport_h2g ||
@@ -484,6 +485,14 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
 	if (!new_transport || !try_module_get(new_transport->module))
 		return -ENODEV;
 
+	if (sk->sk_type == SOCK_SEQPACKET) {
+		if (!new_transport->seqpacket_allow ||
+		    !new_transport->seqpacket_allow(remote_cid)) {
+			module_put(new_transport->module);
+			return -ESOCKTNOSUPPORT;
+		}
+	}
+
 	ret = new_transport->init(vsk, psk);
 	if (ret) {
 		module_put(new_transport->module);
@@ -684,6 +693,7 @@ static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
 
 	switch (sk->sk_socket->type) {
 	case SOCK_STREAM:
+	case SOCK_SEQPACKET:
 		spin_lock_bh(&vsock_table_lock);
 		retval = __vsock_bind_connectible(vsk, addr);
 		spin_unlock_bh(&vsock_table_lock);
@@ -770,7 +780,7 @@ static struct sock *__vsock_create(struct net *net,
 
 static bool sock_type_connectible(u16 type)
 {
-	return type == SOCK_STREAM;
+	return (type == SOCK_STREAM) || (type == SOCK_SEQPACKET);
 }
 
 static void __vsock_release(struct sock *sk, int level)
@@ -849,6 +859,16 @@ s64 vsock_stream_has_data(struct vsock_sock *vsk)
 }
 EXPORT_SYMBOL_GPL(vsock_stream_has_data);
 
+static s64 vsock_has_data(struct vsock_sock *vsk)
+{
+	struct sock *sk = sk_vsock(vsk);
+
+	if (sk->sk_type == SOCK_SEQPACKET)
+		return vsk->transport->seqpacket_has_data(vsk);
+	else
+		return vsock_stream_has_data(vsk);
+}
+
 s64 vsock_stream_has_space(struct vsock_sock *vsk)
 {
 	return vsk->transport->stream_has_space(vsk);
@@ -1857,7 +1877,7 @@ static int vsock_wait_data(struct sock *sk, struct wait_queue_entry *wait,
 	err = 0;
 	transport = vsk->transport;
 
-	while ((data = vsock_stream_has_data(vsk)) == 0) {
+	while ((data = vsock_has_data(vsk)) == 0) {
 		prepare_to_wait(sk_sleep(sk), wait, TASK_INTERRUPTIBLE);
 
 		if (sk->sk_err != 0 ||
@@ -2120,6 +2140,27 @@ static const struct proto_ops vsock_stream_ops = {
 	.sendpage = sock_no_sendpage,
 };
 
+static const struct proto_ops vsock_seqpacket_ops = {
+	.family = PF_VSOCK,
+	.owner = THIS_MODULE,
+	.release = vsock_release,
+	.bind = vsock_bind,
+	.connect = vsock_connect,
+	.socketpair = sock_no_socketpair,
+	.accept = vsock_accept,
+	.getname = vsock_getname,
+	.poll = vsock_poll,
+	.ioctl = sock_no_ioctl,
+	.listen = vsock_listen,
+	.shutdown = vsock_shutdown,
+	.setsockopt = vsock_connectible_setsockopt,
+	.getsockopt = vsock_connectible_getsockopt,
+	.sendmsg = vsock_connectible_sendmsg,
+	.recvmsg = vsock_connectible_recvmsg,
+	.mmap = sock_no_mmap,
+	.sendpage = sock_no_sendpage,
+};
+
 static int vsock_create(struct net *net, struct socket *sock,
 			int protocol, int kern)
 {
@@ -2140,6 +2181,9 @@ static int vsock_create(struct net *net, struct socket *sock,
 	case SOCK_STREAM:
 		sock->ops = &vsock_stream_ops;
 		break;
+	case SOCK_SEQPACKET:
+		sock->ops = &vsock_seqpacket_ops;
+		break;
 	default:
 		return -ESOCKTNOSUPPORT;
 	}