Re: [Xen-devel] [PATCH v4 07/18] xen/pvcalls: implement socket command

[Roger Pau Monné]

On Wed, Jun 21, 2017 at 01:16:56PM -0700, Stefano Stabellini wrote:
> 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@xxxxxxxxxxx>
> > > CC: boris.ostrovsky@xxxxxxxxxx
> > > CC: jgross@xxxxxxxx
> > > ---
> > >  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.

Oh I see. I still think this should be part of the public pvcalls.h
header, and that the error codes should be the ones defined in
public/errno.h (or else also added to the pvcalls header).

Roger.