Re: [PATCH v3 06/13] xen/pvcalls: implement bind command

[Boris Ostrovsky]

On 07/31/2017 06:57 PM, Stefano Stabellini wrote:
> Send PVCALLS_BIND to the backend. Introduce a new structure, part of
> struct sock_mapping, to store information specific to passive sockets.
>
> Introduce a status field to keep track of the status of the passive
> socket.
>
> Signed-off-by: Stefano Stabellini <stefano@xxxxxxxxxxx>
> CC: boris.ostrovsky@xxxxxxxxxx
> CC: jgross@xxxxxxxx
> ---
>   drivers/xen/pvcalls-front.c | 59 +++++++++++++++++++++++++++++++++++++++++++++
>   drivers/xen/pvcalls-front.h |  3 +++
>   2 files changed, 62 insertions(+)
>
> diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
> index 379b8fb..5ccef34 100644
> --- a/drivers/xen/pvcalls-front.c
> +++ b/drivers/xen/pvcalls-front.c
> @@ -59,6 +59,13 @@ struct sock_mapping {
>   
>   			wait_queue_head_t inflight_conn_req;
>   		} active;
> +		struct {
> +		/* Socket status */
> +#define PVCALLS_STATUS_UNINITALIZED  0
> +#define PVCALLS_STATUS_BIND          1
> +#define PVCALLS_STATUS_LISTEN        2
> +			uint8_t status;
> +		} passive;
>   	};
>   };
>   
> @@ -308,6 +315,58 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
>   	return ret;
>   }
>   
> +int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
> +{
> +	struct pvcalls_bedata *bedata;
> +	struct sock_mapping *map = NULL;
> +	struct xen_pvcalls_request *req;
> +	int notify, req_id, ret;
> +
> +	if (!pvcalls_front_dev)
> +		return -ENOTCONN;
> +	if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM)


No protocol check? (in the previous patch too)

-boris

> +		return -ENOTSUPP;
> +	bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
> +
> +	map = (struct sock_mapping *) READ_ONCE(sock->sk->sk_send_head);
> +	if (map == NULL)
> +		return -EINVAL;
> +
> +	spin_lock(&bedata->pvcallss_lock);
> +	ret = get_request(bedata, &req_id);
> +	if (ret < 0) {
> +		spin_unlock(&bedata->pvcallss_lock);
> +		return ret;
> +	}
> +	req = RING_GET_REQUEST(&bedata->ring, req_id);
> +	req->req_id = req_id;
> +	map->sock = sock;
> +	req->cmd = PVCALLS_BIND;
> +	req->u.bind.id = (uint64_t) map;
> +	memcpy(req->u.bind.addr, addr, sizeof(*addr));
> +	req->u.bind.len = addr_len;
> +
> +	init_waitqueue_head(&map->passive.inflight_accept_req);
> +
> +	map->active_socket = false;
> +
> +	bedata->ring.req_prod_pvt++;
> +	RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify);
> +	spin_unlock(&bedata->pvcallss_lock);
> +	if (notify)
> +		notify_remote_via_irq(bedata->irq);
> +
> +	wait_event(bedata->inflight_req,
> +		   READ_ONCE(bedata->rsp[req_id].req_id) == req_id);
> +
> +	map->passive.status = PVCALLS_STATUS_BIND;
> +	ret = bedata->rsp[req_id].ret;
> +	/* read ret, then set this rsp slot to be reused */
> +	smp_mb();
> +	WRITE_ONCE(bedata->rsp[req_id].req_id, PVCALLS_INVALID_ID);
> +	return 0;
> +}
> +
>   static const struct xenbus_device_id pvcalls_front_ids[] = {
>   	{ "pvcalls" },
>   	{ "" }
> diff --git a/drivers/xen/pvcalls-front.h b/drivers/xen/pvcalls-front.h
> index 63b0417..8b0a274 100644
> --- a/drivers/xen/pvcalls-front.h
> +++ b/drivers/xen/pvcalls-front.h
> @@ -6,5 +6,8 @@
>   int pvcalls_front_socket(struct socket *sock);
>   int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
>   			  int addr_len, int flags);
> +int pvcalls_front_bind(struct socket *sock,
> +		       struct sockaddr *addr,
> +		       int addr_len);
>   
>   #endif