Subject: Re: [PATCH v3 07/18] xen/pvcalls: implement socket command
To: Stefano Stabellini <sstabellini@kernel.org>, xen-devel@lists.xen.org
Cc: linux-kernel@vger.kernel.org, boris.ostrovsky@oracle.com,
        Stefano Stabellini <stefano@aporeto.com>
References: <alpine.DEB.2.10.1706021225440.18759@sstabellini-ThinkPad-X260>
 <1496431915-20774-1-git-send-email-sstabellini@kernel.org>
 <1496431915-20774-7-git-send-email-sstabellini@kernel.org>
From: Juergen Gross <jgross@suse.com>
Message-ID: <e034149e-3dfa-8b61-b149-4405afd14c32@suse.com>
Date: Tue, 13 Jun 2017 08:06:31 +0200
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On 02/06/17 21:31, Stefano Stabellini wrote:
> Just reply with success to the other end for now. Delay the allocation
> of the actual socket to bind and/or connect.
> 
> Signed-off-by: Stefano Stabellini <stefano@aporeto.com>
> CC: boris.ostrovsky@oracle.com
> CC: jgross@suse.com
> ---
>  drivers/xen/pvcalls-back.c | 29 ++++++++++++++++++++++++++++-
>  1 file changed, 28 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c
> index 6057533..1f2bb26 100644
> --- a/drivers/xen/pvcalls-back.c
> +++ b/drivers/xen/pvcalls-back.c
> @@ -12,12 +12,17 @@
>   * GNU General Public License for more details.
>   */
>  
> +#include <linux/inet.h>
>  #include <linux/kthread.h>
>  #include <linux/list.h>
>  #include <linux/radix-tree.h>
>  #include <linux/module.h>
>  #include <linux/semaphore.h>
>  #include <linux/wait.h>
> +#include <net/sock.h>
> +#include <net/inet_common.h>
> +#include <net/inet_connection_sock.h>
> +#include <net/request_sock.h>
>  
>  #include <xen/events.h>
>  #include <xen/grant_table.h>
> @@ -54,7 +59,29 @@ struct pvcalls_fedata {
>  static int pvcalls_back_socket(struct xenbus_device *dev,
>  		struct xen_pvcalls_request *req)
>  {
> -	return 0;
> +	struct pvcalls_fedata *priv;
> +	int ret;
> +	struct xen_pvcalls_response *rsp;
> +
> +	priv = dev_get_drvdata(&dev->dev);
> +
> +	if (req->u.socket.domain != AF_INET ||
> +	    req->u.socket.type != SOCK_STREAM ||
> +	    (req->u.socket.protocol != IPPROTO_IP &&
> +	     req->u.socket.protocol != AF_INET))
> +		ret = -EAFNOSUPPORT;
> +	else
> +		ret = 0;
> +
> +	/* leave the actual socket allocation for later */
> +
> +	rsp = RING_GET_RESPONSE(&priv->ring, priv->ring.rsp_prod_pvt++);
> +	rsp->req_id = req->req_id;
> +	rsp->cmd = req->cmd;
> +	rsp->u.socket.id = req->u.socket.id;
> +	rsp->ret = ret;
> +
> +	return ret;

So if ret != 0 this will omit the call of
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY() in pvcalls_back_work().

I think you want to return 0.


Juergen