Re: [PATCH net-next 1/2] selftests: openvswitch: fix action formatting

[Adrián Moreno]

On Mon, Jun 03, 2024 at 03:00:03PM GMT, Aaron Conole wrote:
> Adrian Moreno <amorenoz@xxxxxxxxxx> writes:
>
> > In the action formatting function ("dpstr"), the iteration is made over
> > the nla_map, so if there are more than one attribute from the same type
> > we only print the first one.
> >
> > Fix this by iterating over the actual attributes.
> >
> > Signed-off-by: Adrian Moreno <amorenoz@xxxxxxxxxx>
> > ---
> >  .../selftests/net/openvswitch/ovs-dpctl.py    | 48 +++++++++++--------
> >  1 file changed, 27 insertions(+), 21 deletions(-)
> >
> > diff --git a/tools/testing/selftests/net/openvswitch/ovs-dpctl.py b/tools/testing/selftests/net/openvswitch/ovs-dpctl.py
> > index 1dd057afd3fb..b76907ac0092 100644
> > --- a/tools/testing/selftests/net/openvswitch/ovs-dpctl.py
> > +++ b/tools/testing/selftests/net/openvswitch/ovs-dpctl.py
> > @@ -437,40 +437,46 @@ class ovsactions(nla):
> >      def dpstr(self, more=False):
> >          print_str = ""
> >
> > -        for field in self.nla_map:
> > -            if field[1] == "none" or self.get_attr(field[0]) is None:
> > +        for attr_name, value in self["attrs"]:
> > +            attr_desc = next(filter(lambda x: x[0] == attr_name, self.nla_map),
> > +                             None)
> > +            if not attr_desc:
> > +                raise ValueError("Unknown attribute: %s" % attr)
> > +
> > +            attr_type = attr_desc[1]
> > +
> > +            if attr_type == "none":
>
> I agree, this is an issue.  BUT I think it might be better to just
> filter by field type up front.  See:
>
> https://github.com/apconole/linux-next-work/commit/7262107de7170d44b6dbf6c5ea6f7e6c0bb71d36#diff-3e72e7405c6bb4e9842bed5f63883ca930387086bb40d4034e92ed83a5decb4bR441
>
> That version I think ends up being much easier to follow.  If you want
> to take it for your series, feel free.  If you disagree, maybe there's
> something I'm not considering about it.
>

I agree. It's better to check field attribute names first. I found this
during manual testing of the "emit_sample" series but I ended up not
needing it for the automated one, so I'm OK waiting for your cleanup
series.

In fact, I also have some patches that try some rework of this part. In
particular, I tried to unify all attributes under a common base class
that would handle printing and parsing. That way, most cases would fall
into "print_str += datum.dpstr(more)" and the "if/elif" block would
shrink significantly.

> NOTE that version is just a bunch of independent changes that are
> squashed together.  I have a cleaner version.
>
> I can also bundle up the series I have so far and submit, but I didn't
> want to do that until I got all the pmtu.sh support working.  Maybe it
> makes sense to send it now though.  Simon, Jakub - wdyt?
>
> >                  continue
> >              if print_str != "":
> >                  print_str += ","
> >
> > -            if field[1] == "uint32":
> > -                if field[0] == "OVS_ACTION_ATTR_OUTPUT":
> > -                    print_str += "%d" % int(self.get_attr(field[0]))
> > -                elif field[0] == "OVS_ACTION_ATTR_RECIRC":
> > -                    print_str += "recirc(0x%x)" % int(self.get_attr(field[0]))
> > -                elif field[0] == "OVS_ACTION_ATTR_TRUNC":
> > -                    print_str += "trunc(%d)" % int(self.get_attr(field[0]))
> > -                elif field[0] == "OVS_ACTION_ATTR_DROP":
> > -                    print_str += "drop(%d)" % int(self.get_attr(field[0]))
> > -            elif field[1] == "flag":
> > -                if field[0] == "OVS_ACTION_ATTR_CT_CLEAR":
> > +            if attr_type == "uint32":
> > +                if attr_name == "OVS_ACTION_ATTR_OUTPUT":
> > +                    print_str += "%d" % int(value)
> > +                elif attr_name == "OVS_ACTION_ATTR_RECIRC":
> > +                    print_str += "recirc(0x%x)" % int(value)
> > +                elif attr_name == "OVS_ACTION_ATTR_TRUNC":
> > +                    print_str += "trunc(%d)" % int(value)
> > +                elif attr_name == "OVS_ACTION_ATTR_DROP":
> > +                    print_str += "drop(%d)" % int(value)
> > +            elif attr_type == "flag":
> > +                if attr_name == "OVS_ACTION_ATTR_CT_CLEAR":
> >                      print_str += "ct_clear"
> > -                elif field[0] == "OVS_ACTION_ATTR_POP_VLAN":
> > +                elif attr_name == "OVS_ACTION_ATTR_POP_VLAN":
> >                      print_str += "pop_vlan"
> > -                elif field[0] == "OVS_ACTION_ATTR_POP_ETH":
> > +                elif attr_name == "OVS_ACTION_ATTR_POP_ETH":
> >                      print_str += "pop_eth"
> > -                elif field[0] == "OVS_ACTION_ATTR_POP_NSH":
> > +                elif attr_name == "OVS_ACTION_ATTR_POP_NSH":
> >                      print_str += "pop_nsh"
> > -                elif field[0] == "OVS_ACTION_ATTR_POP_MPLS":
> > +                elif attr_name == "OVS_ACTION_ATTR_POP_MPLS":
> >                      print_str += "pop_mpls"
> >              else:
> > -                datum = self.get_attr(field[0])
> > -                if field[0] == "OVS_ACTION_ATTR_CLONE":
> > +                if attr_name == "OVS_ACTION_ATTR_CLONE":
> >                      print_str += "clone("
> > -                    print_str += datum.dpstr(more)
> > +                    print_str += value.dpstr(more)
> >                      print_str += ")"
> >                  else:
> > -                    print_str += datum.dpstr(more)
> > +                    print_str += value.dpstr(more)
> >
> >          return print_str
>