Re: [RFC PATCH v3 01/13] af_vsock: prepare for SOCK_SEQPACKET support

[Stefano Garzarella <sgarzare@redhat.com>]

I think the patch title should be more explicit, so something like

vsock: generalize function to manage connectible sockets

On Mon, Jan 25, 2021 at 02:11:28PM +0300, Arseny Krasnov wrote:
>This prepares af_vsock.c for SEQPACKET support:
>1) As both stream and seqpacket sockets are connection oriented, add
>   check for SOCK_SEQPACKET to conditions where SOCK_STREAM is checked.
>2) Some functions such as setsockopt(), getsockopt(), connect(),
>   recvmsg(), sendmsg() are shared between both types of sockets, so
>   rename them in general manner and create entry points for each type
>   of socket to call these functions(for stream in this patch, for
>   seqpacket in further patches).
>
>Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
>---
> net/vmw_vsock/af_vsock.c | 91 +++++++++++++++++++++++++++++-----------
> 1 file changed, 67 insertions(+), 24 deletions(-)
>
>diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>index b12d3a322242..c9ce57db9554 100644
>--- a/net/vmw_vsock/af_vsock.c
>+++ b/net/vmw_vsock/af_vsock.c
>@@ -604,8 +604,8 @@ static void vsock_pending_work(struct work_struct *work)
>
> /**** SOCKET OPERATIONS ****/
>
>-static int __vsock_bind_stream(struct vsock_sock *vsk,
>-			       struct sockaddr_vm *addr)
>+static int __vsock_bind_connectible(struct vsock_sock *vsk,
>+				    struct sockaddr_vm *addr)
> {
> 	static u32 port;
> 	struct sockaddr_vm new_addr;
>@@ -685,7 +685,7 @@ static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
> 	switch (sk->sk_socket->type) {
> 	case SOCK_STREAM:
> 		spin_lock_bh(&vsock_table_lock);
>-		retval = __vsock_bind_stream(vsk, addr);
>+		retval = __vsock_bind_connectible(vsk, addr);
> 		spin_unlock_bh(&vsock_table_lock);
> 		break;
>
>@@ -767,6 +767,11 @@ static struct sock *__vsock_create(struct net *net,
> 	return sk;
> }
>
>+static bool sock_type_connectible(u16 type)
>+{
>+	return (type == SOCK_STREAM || type == SOCK_SEQPACKET);
>+}
>+

I think it's okay to add this function in this patch, but until 
SOCK_SEQPACKET is not supported, I would check only SOCK_STREAM and add 
SOCK_SEQPACKET only when you add 'vsock_seqpacket_ops' later.

> static void __vsock_release(struct sock *sk, int level)
> {
> 	if (sk) {
>@@ -785,7 +790,7 @@ static void __vsock_release(struct sock *sk, int level)
>
> 		if (vsk->transport)
> 			vsk->transport->release(vsk);
>-		else if (sk->sk_type == SOCK_STREAM)
>+		else if (sock_type_connectible(sk->sk_type))
> 			vsock_remove_sock(vsk);
>
> 		sock_orphan(sk);
>@@ -945,7 +950,7 @@ static int vsock_shutdown(struct socket *sock, int mode)
> 	sk = sock->sk;
> 	if (sock->state == SS_UNCONNECTED) {
> 		err = -ENOTCONN;
>-		if (sk->sk_type == SOCK_STREAM)
>+		if (sock_type_connectible(sk->sk_type))
> 			return err;
> 	} else {
> 		sock->state = SS_DISCONNECTING;
>@@ -960,7 +965,7 @@ static int vsock_shutdown(struct socket *sock, int mode)
> 		sk->sk_state_change(sk);
> 		release_sock(sk);
>
>-		if (sk->sk_type == SOCK_STREAM) {
>+		if (sock_type_connectible(sk->sk_type)) {
> 			sock_reset_flag(sk, SOCK_DONE);
> 			vsock_send_shutdown(sk, mode);
> 		}
>@@ -1013,7 +1018,7 @@ static __poll_t vsock_poll(struct file *file, struct socket *sock,
> 		if (!(sk->sk_shutdown & SEND_SHUTDOWN))
> 			mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
>
>-	} else if (sock->type == SOCK_STREAM) {
>+	} else if (sock_type_connectible(sk->sk_type)) {
> 		const struct vsock_transport *transport = vsk->transport;
> 		lock_sock(sk);
>
>@@ -1259,8 +1264,8 @@ static void vsock_connect_timeout(struct work_struct *work)
> 	sock_put(sk);
> }
>
>-static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
>-				int addr_len, int flags)
>+static int vsock_connect(struct socket *sock, struct sockaddr *addr,
>+			 int addr_len, int flags)
> {
> 	int err;
> 	struct sock *sk;
>@@ -1395,6 +1400,12 @@ static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
> 	return err;
> }
>
>+static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
>+				int addr_len, int flags)
>+{
>+	return vsock_connect(sock, addr, addr_len, flags);
>+}
>+

I think you can directly use vsock_connect in 'vsock_stream_ops'.

> static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
> 			bool kern)
> {
>@@ -1410,7 +1421,7 @@ static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
>
> 	lock_sock(listener);
>
>-	if (sock->type != SOCK_STREAM) {
>+	if (!sock_type_connectible(sock->type)) {
> 		err = -EOPNOTSUPP;
> 		goto out;
> 	}
>@@ -1487,7 +1498,7 @@ static int vsock_listen(struct socket *sock, int 
>backlog)
>
> 	lock_sock(sk);
>
>-	if (sock->type != SOCK_STREAM) {
>+	if (!sock_type_connectible(sk->sk_type)) {
> 		err = -EOPNOTSUPP;
> 		goto out;
> 	}
>@@ -1531,11 +1542,11 @@ static void vsock_update_buffer_size(struct vsock_sock *vsk,
> 	vsk->buffer_size = val;
> }
>
>-static int vsock_stream_setsockopt(struct socket *sock,
>-				   int level,
>-				   int optname,
>-				   sockptr_t optval,
>-				   unsigned int optlen)
>+static int vsock_connectible_setsockopt(struct socket *sock,
>+					int level,
>+					int optname,
>+					sockptr_t optval,
>+					unsigned int optlen)
> {
> 	int err;
> 	struct sock *sk;
>@@ -1612,10 +1623,20 @@ static int vsock_stream_setsockopt(struct socket *sock,
> 	return err;
> }
>
>-static int vsock_stream_getsockopt(struct socket *sock,
>-				   int level, int optname,
>-				   char __user *optval,
>-				   int __user *optlen)
>+static int vsock_stream_setsockopt(struct socket *sock,
>+				   int level,
>+				   int optname,
>+				   sockptr_t optval,
>+				   unsigned int optlen)
>+{
>+	return vsock_connectible_setsockopt(sock, level, optname, optval,
>+					    optlen);
>+}

As before, I think you can directly use vsock_connectible_setsockopt in 
'vsock_stream_ops'.

>+
>+static int vsock_connectible_getsockopt(struct socket *sock,
>+					int level, int optname,
>+					char __user *optval,
>+					int __user *optlen)
> {
> 	int err;
> 	int len;
>@@ -1683,8 +1704,17 @@ static int vsock_stream_getsockopt(struct socket *sock,
> 	return 0;
> }
>
>-static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
>-				size_t len)
>+static int vsock_stream_getsockopt(struct socket *sock,
>+				   int level, int optname,
>+				   char __user *optval,
>+				   int __user *optlen)
>+{
>+	return vsock_connectible_getsockopt(sock, level, optname, optval,
>+					    optlen);
>+}
>+

Ditto.

>+static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
>+				     size_t len)
> {
> 	struct sock *sk;
> 	struct vsock_sock *vsk;
>@@ -1822,10 +1852,16 @@ static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
> 	return err;
> }
>
>+static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
>+				size_t len)
>+{
>+	return vsock_connectible_sendmsg(sock, msg, len);
>+}
>+

Ditto.

>
> static int
>-vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
>-		     int flags)
>+vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
>+			  int flags)
> {
> 	struct sock *sk;
> 	struct vsock_sock *vsk;
>@@ -1995,6 +2031,13 @@ vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
> 	return err;
> }
>
>+static int
>+vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
>+		     int flags)
>+{
>+	return vsock_connectible_recvmsg(sock, msg, len, flags);
>+}
>+

Ditto.

> static const struct proto_ops vsock_stream_ops = {
> 	.family = PF_VSOCK,
> 	.owner = THIS_MODULE,
>-- 
>2.25.1
>