Re: [PATCH] netfilter: xt_TPROXY: remove pr_debug invocations

[Justin Stitt <justinstitt@google.com>]

On Tue, Jul 12, 2022 at 11:56 AM Nathan Chancellor <nathan@kernel.org> wrote:
>
> Hi Justin,
>
> On Tue, Jul 12, 2022 at 11:34:52AM -0700, Justin Stitt wrote:
> > pr_debug calls are no longer needed in this file.
> >
> > Pablo suggested "a patch to remove these pr_debug calls". This patch has
> > some other beneficial collateral as it also silences multiple Clang
> > -Wformat warnings that were present in the pr_debug calls.
> >
> > Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
> > Signed-off-by: Justin Stitt <justinstitt@google.com>
>
> Thanks for the patch!
>
> Reviewed-by: Nathan Chancellor <nathan@kernel.org>
>
> Couple of style comments below that probably warrant a v2, you can carry
> the above tag forward for future revisions. No need to give me a
> "Suggested-by".
>
> > ---
> > Suggestion here: https://lore.kernel.org/all/Ys0zZACWwGilTwHx@salvia/
> >
> >  net/netfilter/xt_TPROXY.c | 19 -------------------
> >  1 file changed, 19 deletions(-)
> >
> > diff --git a/net/netfilter/xt_TPROXY.c b/net/netfilter/xt_TPROXY.c
> > index 459d0696c91a..dc7284e6357b 100644
> > --- a/net/netfilter/xt_TPROXY.c
> > +++ b/net/netfilter/xt_TPROXY.c
> > @@ -74,18 +74,10 @@ tproxy_tg4(struct net *net, struct sk_buff *skb, __be32 laddr, __be16 lport,
> >               /* This should be in a separate target, but we don't do multiple
> >                  targets on the same rule yet */
> >               skb->mark = (skb->mark & ~mark_mask) ^ mark_value;
> > -
> > -             pr_debug("redirecting: proto %hhu %pI4:%hu -> %pI4:%hu, mark: %x\n",
> > -                      iph->protocol, &iph->daddr, ntohs(hp->dest),
> > -                      &laddr, ntohs(lport), skb->mark);
> > -
> >               nf_tproxy_assign_sock(skb, sk);
> >               return NF_ACCEPT;
> >       }
> >
> > -     pr_debug("no socket, dropping: proto %hhu %pI4:%hu -> %pI4:%hu, mark: %x\n",
> > -              iph->protocol, &iph->saddr, ntohs(hp->source),
> > -              &iph->daddr, ntohs(hp->dest), skb->mark);
> >       return NF_DROP;
> >  }
> >
> > @@ -123,13 +115,11 @@ tproxy_tg6_v1(struct sk_buff *skb, const struct xt_action_param *par)
> >
> >       tproto = ipv6_find_hdr(skb, &thoff, -1, NULL, NULL);
> >       if (tproto < 0) {
>
> checkpatch.pl should have warned that these if statement braces here and
> below are no longer necessary because there is only one statement within
> them now.
Weirdly, checkpatch.pl gave 0 warnings regarding this patch. At any
rate, v2 is coming shortly. Thanks for the review!

>
>         if (tproto < 0)
>                 return NF_DROP;
>
> I believe it is important to do these types of style cleanups when doing
> a larger change so that people do not try to do them as standalone
> changes, which can irritate maintainers.
>
> > -             pr_debug("unable to find transport header in IPv6 packet, dropping\n");
> >               return NF_DROP;
> >       }
> >
> >       hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr);
> >       if (hp == NULL) {
> > -             pr_debug("unable to grab transport header contents in IPv6 packet, dropping\n");
> >               return NF_DROP;
> >       }
>
>         if (hp == NULL)
>                 return NF_DROP;
>
> could even go a step farther and make it
>
>         if (!hp)
>                 return NF_DROP;
>
> if there is a warning about that.
>
> >
> > @@ -168,19 +158,10 @@ tproxy_tg6_v1(struct sk_buff *skb, const struct xt_action_param *par)
> >               /* This should be in a separate target, but we don't do multiple
> >                  targets on the same rule yet */
> >               skb->mark = (skb->mark & ~tgi->mark_mask) ^ tgi->mark_value;
> > -
> > -             pr_debug("redirecting: proto %hhu %pI6:%hu -> %pI6:%hu, mark: %x\n",
> > -                      tproto, &iph->saddr, ntohs(hp->source),
> > -                      laddr, ntohs(lport), skb->mark);
> > -
> >               nf_tproxy_assign_sock(skb, sk);
> >               return NF_ACCEPT;
> >       }
> >
> > -     pr_debug("no socket, dropping: proto %hhu %pI6:%hu -> %pI6:%hu, mark: %x\n",
> > -              tproto, &iph->saddr, ntohs(hp->source),
> > -              &iph->daddr, ntohs(hp->dest), skb->mark);
> > -
> >       return NF_DROP;
> >  }
> >
> > --
> > 2.37.0.144.g8ac04bfd2-goog
> >