Re: [RFC PATCH v2 06/13] af_vsock: general support of SOCK_SEQPACKET type.

[Stefano Garzarella <sgarzare@xxxxxxxxxx>]

On Fri, Jan 15, 2021 at 08:42:43AM +0300, Arseny Krasnov wrote:
> This adds socket operations for SOCK_SEQPACKET and adds this type of
> socket for conditions where SOCK_STREAM is involved because both type of
> sockets are connect oriented.
>
> Signed-off-by: Arseny Krasnov <arseny.krasnov@xxxxxxxxxxxxx>
> ---
> net/vmw_vsock/af_vsock.c | 108 +++++++++++++++++++++++++++++++++------
> 1 file changed, 92 insertions(+), 16 deletions(-)
>
> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> index 4a7cdf7756c0..d0ef066e9352 100644
> --- a/net/vmw_vsock/af_vsock.c
> +++ b/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 ||
> @@ -459,6 +460,13 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
> 			new_transport = transport_g2h;
> 		else
> 			new_transport = transport_h2g;
> +
> +		if (sk->sk_type == SOCK_SEQPACKET) {
> +			if (!new_transport->seqpacket_seq_send_len ||
> +			    !new_transport->seqpacket_seq_get_len ||
> +			    !new_transport->seqpacket_dequeue)
> +				return -ENODEV;
> +		}
> 		break;
> 	default:
> 		return -ESOCKTNOSUPPORT;
> @@ -604,8 +612,8 @@ 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;
> @@ -684,8 +692,9 @@ 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_stream(vsk, addr);
> +		retval = __vsock_bind_connectible(vsk, addr);
> 		spin_unlock_bh(&vsock_table_lock);
> 		break;
>
> @@ -767,6 +776,11 @@ static struct sock *__vsock_create(struct net *net,
> 	return sk;
> }
>
> +static bool sock_type_connectible(u16 type)
> +{
> +	return (type == SOCK_STREAM || type == SOCK_SEQPACKET);
> +}
> +
> static void __vsock_release(struct sock *sk, int level)
> {
> 	if (sk) {
> @@ -785,7 +799,7 @@ 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 +959,7 @@ 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 +974,7 @@ 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 +1027,7 @@ 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 +1273,8 @@ 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;
> @@ -1410,7 +1424,7 @@ 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;
> 	}
> @@ -1477,6 +1491,18 @@ static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
> 	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);
> +}
> +
> +static int vsock_seqpacket_connect(struct socket *sock, struct sockaddr *addr,
> +				   int addr_len, int flags)
> +{
> +	return vsock_connect(sock, addr, addr_len, flags);
> +}
> +
> static int vsock_listen(struct socket *sock, int backlog)
> {
> 	int err;
> @@ -1487,7 +1513,7 @@ 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 +1557,11 @@ 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_setsockopt(struct socket *sock,
> +			    int level,
> +			    int optname,
> +			    sockptr_t optval,
> +			    unsigned int optlen)
> {
> 	int err;
> 	struct sock *sk;
> @@ -1612,6 +1638,24 @@ static int vsock_stream_setsockopt(struct socket *sock,
> 	return err;
> }
>
> +static int vsock_seqpacket_setsockopt(struct socket *sock,
> +				      int level,
> +				      int optname,
> +				      sockptr_t optval,
> +				      unsigned int optlen)
> +{
> +	return vsock_setsockopt(sock, level, optname, optval, optlen);
> +}
> +
> +static int vsock_stream_setsockopt(struct socket *sock,
> +				   int level,
> +				   int optname,
> +				   sockptr_t optval,
> +				   unsigned int optlen)
> +{
> +	return vsock_setsockopt(sock, level, optname, optval, optlen);
> +}
> +
> static int vsock_stream_getsockopt(struct socket *sock,
> 				   int level, int optname,
> 				   char __user *optval,
> @@ -1683,6 +1727,14 @@ static int vsock_stream_getsockopt(struct socket *sock,
> 	return 0;
> }
>
> +static int vsock_seqpacket_getsockopt(struct socket *sock,
> +				      int level, int optname,
> +				      char __user *optval,
> +				      int __user *optlen)
> +{
> +	return vsock_stream_getsockopt(sock, level, optname, optval, optlen);
> +}
> +

Why didn't you do the same thing you did with setsockopt?

Both are fine for me, but I'd like to do the same thing for getsockopt 
and setsockopt.

If you opt to create new functions, maybe it's better to call them 
vsock_connectible_*sockopt()

> static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
> 				     size_t len)
> {
> @@ -2184,6 +2236,27 @@ 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_seqpacket_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_seqpacket_setsockopt,
> +	.getsockopt = vsock_seqpacket_getsockopt,
> +	.sendmsg = vsock_seqpacket_sendmsg,
> +	.recvmsg = vsock_seqpacket_recvmsg,
> +	.mmap = sock_no_mmap,
> +	.sendpage = sock_no_sendpage,
> +};
> +
> static int vsock_create(struct net *net, struct socket *sock,
> 			int protocol, int kern)
> {
> @@ -2204,6 +2277,9 @@ 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;
> 	}
> --
> 2.25.1