DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BB388217C3
Date: Wed, 21 Jun 2017 13:16:56 -0700 (PDT)
From: Stefano Stabellini <sstabellini@kernel.org>
To: =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= <roger.pau@citrix.com>
cc: Stefano Stabellini <sstabellini@kernel.org>, xen-devel@lists.xen.org,
        jgross@suse.com, Stefano Stabellini <stefano@aporeto.com>,
        boris.ostrovsky@oracle.com, linux-kernel@vger.kernel.org
Subject: Re: [Xen-devel] [PATCH v4 07/18] xen/pvcalls: implement socket
 command
In-Reply-To: <20170620161112.7x4qickboyt7qyvh@dhcp-3-128.uk.xensource.com>
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On Tue, 20 Jun 2017, Roger Pau Monné wrote:
> On Thu, Jun 15, 2017 at 12:09:36PM -0700, 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 | 27 +++++++++++++++++++++++++++
> >  1 file changed, 27 insertions(+)
> > 
> > diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c
> > index 437c2ad..953458b 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>
> > @@ -54,6 +59,28 @@ struct pvcalls_fedata {
> >  static int pvcalls_back_socket(struct xenbus_device *dev,
> >  		struct xen_pvcalls_request *req)
> >  {
> > +	struct pvcalls_fedata *fedata;
> > +	int ret;
> > +	struct xen_pvcalls_response *rsp;
> > +
> > +	fedata = 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;
> 
> Sorry for jumping into this out of the blue, but shouldn't all the
> constants used above be part of the protocol? AF_INET/SOCK_STREAM/...
> are all part of POSIX, but their specific value is not defined in the
> standard, hence we should have XEN_AF_INET/XEN_SOCK_STREAM/... Or am I
> just missing something?

The values of these constants for the pvcalls protocol are defined by
docs/misc/pvcalls.markdown under "Socket families and address format".

They happen to be the same as the ones defined by Linux as AF_INET,
SOCK_STREAM, etc, so in Linux I am just using those, but that is just an
implementation detail internal to the Linux kernel driver. What is
important from the protocol ABI perspective are the values defined by
docs/misc/pvcalls.markdown.
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