Re: [tcpdump] After setjmp/longjmp update

[Francois-Xavier Le Bail via tcpdump-workers <tcpdump-workers () lists tcpdump org>]

> --- Begin Message ---
>
>
> From: Francois-Xavier Le Bail <devel.fx.lebail () orange fr>
>
> Date: Fri, 18 Sep 2020 10:25:13 +0200
>
> On 17/09/2020 22:05, Francois-Xavier Le Bail via tcpdump-workers wrote:
> > On 17/09/2020 16:15, Denis Ovsienko via tcpdump-workers wrote:
> > > On Sat, 5 Sep 2020 18:20:42 +0200
> > > Francois-Xavier Le Bail via tcpdump-workers
> > > <tcpdump-workers () lists tcpdump org> wrote:
> > >
> > > > 2) Process all the truncated cases with:
> > > > ndo->ndo_ll_hdr_len = 0;
> > > > longjmp(ndo->ndo_truncated, 1);
> > > > (With a new macro, like 'ND_TRUNCATED' or 'ND_IS_TRUNCATED')
> > > The master branch now has a change along these lines. Whilst preparing
> > > changes to a couple decoders based on that (still work in progress), I
> > > managed to make some observations, will post as soon as it all looks
> > > good and makes sense.
> > Should we have something like:
> >
> >         if (setjmp(ndo->early_end) == 0) {
> >                 /* Print the packet. */
> >                 (ndo->ndo_if_printer)(ndo, h, sp);
> >         } else {
> >                 switch (ndo->early_end_reason) {
> >               case TRUNCATED:
> >                       /* A printer quit because the packet was truncated; report it */
> >                       nd_print_trunc(ndo);
> >                       break;
> >                 case INVALID:
> >                       ...
> >               }
> >         }
> >
> > (ndo->ndo_truncated -> ndo->early_end and ndo->early_end_reason = TRUNCATED/INVALID/other?
>
> Or perhaps better (no need for a 'early_end_reason' field):
>         switch (setjmp(ndo->early_end)) {
>         case 0:
>                 /* Print the packet. */
>                 (ndo->ndo_if_printer)(ndo, h, sp);
>                 break;
>         case ND_TRUNCATED:
>                 /* A printer quit because the packet was truncated; report it */
>                 nd_print_trunc(ndo);
>                 break;
>         case ND_INVALID:
>                 ND_PRINT(" (invalid)"); /* or calling a function that do the print */
>         }
>
> With:
> #define ND_TRUNCATED 1
> #define ND_INVALID   2
> and use
> longjmp(ndo->early_end, ND_TRUNCATED); /* for packet truncated cases */
> longjmp(ndo->early_end, ND_INVALID);   /* for invalid cases (bad length, etc.) */
>
> -- 
> Francois-Xavier
>
> --- End Message ---
_______________________________________________
tcpdump-workers mailing list
tcpdump-workers () lists tcpdump org
https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers