Re: [PATCH RFC net-next v4 4/8] vsock: make vsock bind reusable

[Stefano Garzarella <sgarzare@xxxxxxxxxx>]

On Sat, Jun 10, 2023 at 12:58:31AM +0000, Bobby Eshleman wrote:
> This commit makes the bind table management functions in vsock usable
> for different bind tables. For use by datagrams in a future patch.
>
> Signed-off-by: Bobby Eshleman <bobby.eshleman@xxxxxxxxxxxxx>
> ---
> net/vmw_vsock/af_vsock.c | 33 ++++++++++++++++++++++++++-------
> 1 file changed, 26 insertions(+), 7 deletions(-)
>
> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> index ef86765f3765..7a3ca4270446 100644
> --- a/net/vmw_vsock/af_vsock.c
> +++ b/net/vmw_vsock/af_vsock.c
> @@ -230,11 +230,12 @@ static void __vsock_remove_connected(struct vsock_sock *vsk)
> 	sock_put(&vsk->sk);
> }
>
> -static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
> +struct sock *vsock_find_bound_socket_common(struct sockaddr_vm *addr,
> +					    struct list_head *bind_table)
> {
> 	struct vsock_sock *vsk;
>
> -	list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
> +	list_for_each_entry(vsk, bind_table, bound_table) {
> 		if (vsock_addr_equals_addr(addr, &vsk->local_addr))
> 			return sk_vsock(vsk);
>
> @@ -247,6 +248,11 @@ static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
> 	return NULL;
> }
>
> +static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
> +{
> +	return vsock_find_bound_socket_common(addr, vsock_bound_sockets(addr));
> +}
> +
> static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
> 						  struct sockaddr_vm *dst)
> {
> @@ -646,12 +652,17 @@ static void vsock_pending_work(struct work_struct *work)
>
> /**** SOCKET OPERATIONS ****/
>
> -static int __vsock_bind_connectible(struct vsock_sock *vsk,
> -				    struct sockaddr_vm *addr)
> +static int vsock_bind_common(struct vsock_sock *vsk,
> +			     struct sockaddr_vm *addr,
> +			     struct list_head *bind_table,
> +			     size_t table_size)
> {
> 	static u32 port;
> 	struct sockaddr_vm new_addr;
>
> +	if (table_size < VSOCK_HASH_SIZE)
> +		return -1;

Why we need this check now?

> +
> 	if (!port)
> 		port = get_random_u32_above(LAST_RESERVED_PORT);
>
> @@ -667,7 +678,8 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
>
> 			new_addr.svm_port = port++;
>
> -			if (!__vsock_find_bound_socket(&new_addr)) {
> +			if (!vsock_find_bound_socket_common(&new_addr,
> +							    &bind_table[VSOCK_HASH(addr)])) {
> 				found = true;
> 				break;
> 			}
> @@ -684,7 +696,8 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
> 			return -EACCES;
> 		}
>
> -		if (__vsock_find_bound_socket(&new_addr))
> +		if (vsock_find_bound_socket_common(&new_addr,
> +						   &bind_table[VSOCK_HASH(addr)]))
> 			return -EADDRINUSE;
> 	}
>
> @@ -696,11 +709,17 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
> 	 * by AF_UNIX.
> 	 */
> 	__vsock_remove_bound(vsk);
> -	__vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
> +	__vsock_insert_bound(&bind_table[VSOCK_HASH(&vsk->local_addr)], vsk);
>
> 	return 0;
> }
>
> +static int __vsock_bind_connectible(struct vsock_sock *vsk,
> +				    struct sockaddr_vm *addr)
> +{
> +	return vsock_bind_common(vsk, addr, vsock_bind_table, VSOCK_HASH_SIZE + 1);
> +}
> +
> static int __vsock_bind_dgram(struct vsock_sock *vsk,
> 			      struct sockaddr_vm *addr)
> {
>
> --
> 2.30.2

The rest seems okay to me, but I agree with Simon's suggestion.

Stefano