Re: [PATCH 1/2] ebtables: processing '--concurrent' beofore other arguments

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Tue, Apr 06, 2021 at 10:57:37AM +0800, Firo Yang wrote:
> The 04/03/2021 20:22, Pablo Neira Ayuso wrote:
> > On Sat, Apr 03, 2021 at 08:15:17PM +0200, Pablo Neira Ayuso wrote:
> > > Hi,
> > >
> > > On Thu, Apr 01, 2021 at 12:07:40PM +0800, Firo Yang wrote:
> > > > Our customer reported a following issue:
> > > > If '--concurrent' was passed to ebtables command behind other arguments,
> > > > '--concurrent' will not take effect sometimes; for a simple example,
> > > > ebtables -L --concurrent. This is becuase the handling of '--concurrent'
> > > > is implemented in a passing-order-dependent way.
> > > >
> > > > So we can fix this problem by processing it before other arguments.
> > >
> > > Would you instead make a patch to spew an error if --concurrent is the
> > > first argument?
> >
> > Wrong wording:
> >
> > Would you instead make a patch to spew an error if --concurrent is
> > _not_ the first argument?
>
> Hi Pablo, I think it would make more sense if we don't introduce this
> inconvenice to users. If you insist, I would go create the patch as you
> intended.

See ebtables.c line 579.

        /* The scenario induced by this loop makes that:
         * '-t'  ,'-M' and --atomic (if specified) have to come
         * before '-A' and the like */

There are other options following this approach, please align
--concurrent with those.

Have a look at 'M' and 't' for the error that is reported.

                case 'M': /* Modprobe */
                        if (OPT_COMMANDS)
                                ebt_print_error2("Please put the -M option earlier");

Thanks.