Subject: Re: [p4tc-discussions] Re: [PATCH RFC v2 net-next 12/28] p4tc: add header field create, get, delete, flush and dump

From: Simon Horman <[email-masked]>
Date: Mon, 5 Jun 2023 17:14:21 +0200

On Mon, Jun 05, 2023 at 10:48:18AM -0400, Jamal Hadi Salim wrote:
> On Mon, Jun 5, 2023 at 6:25 AM Simon Horman via p4tc-discussions
> <[email-masked]> wrote:
> >
> > On Wed, May 17, 2023 at 07:02:16AM -0400, Jamal Hadi Salim wrote:
> >
> > ...
> >
> > Hi Victor, Pedro and Jamal,
> >
> > some minor feedback from my side.
> >
> > > +static int _tcf_hdrfield_fill_nlmsg(struct sk_buff *skb,
> > > +                                 struct p4tc_hdrfield *hdrfield)
> > > +{
> > > +     unsigned char *b = nlmsg_get_pos(skb);
> > > +     struct p4tc_hdrfield_ty hdr_arg;
> > > +     struct nlattr *nest;
> > > +     /* Parser instance id + header field id */
> > > +     u32 ids[2];
> > > +
> > > +     ids[0] = hdrfield->parser_inst_id;
> > > +     ids[1] = hdrfield->hdrfield_id;
> > > +
> > > +     if (nla_put(skb, P4TC_PATH, sizeof(ids), ids))
> > > +             goto out_nlmsg_trim;
> > > +
> > > +     nest = nla_nest_start(skb, P4TC_PARAMS);
> > > +     if (!nest)
> > > +             goto out_nlmsg_trim;
> > > +
> > > +     hdr_arg.datatype = hdrfield->datatype;
> > > +     hdr_arg.startbit = hdrfield->startbit;
> > > +     hdr_arg.endbit = hdrfield->endbit;
> >
> > There may be padding at the end of hdr_arg,
> > which is passed uninitialised to nla_put below.
> 
> Yeah, same comment as the metadata case; we could add initialization
> or add PADx at the end. Or maybe there's another approach you had in
> mind.

Thanks. Yes it is  the same comment, sorry for the duplicate.
No, I don't have suggestions other than the ones you have made.