On Mon, Sep 14, 2020 at 09:32:46AM +0200, Martijn van Duren wrote:
> On Mon, 2020-09-14 at 08:12 +0100, Stuart Henderson wrote:
> > On 2020/09/13 22:48, Giovanni Bechis wrote:
> > > "smtpctl spf walk" doesn't work as it should because it breaks when it
> > > finds
> > > macros as defined in RFC 7208.
> > >
> > > $ echo ryanair.com | smtpctl spf walk
> > > gives no output while dig reply is:
> > > $ dig txt ryanair.com | grep spf
> > > ryanair.com. 17 IN TXT "v=spf1
> > > include:ryanair.com._nspf.vali.email
> > > include:%{i}._ip.%{h}._ehlo.%{d}._spf.vali.email ~all"
> >
> > "spf walk" should return a warning or an error in these cases.
>
> Was already working on that. How about the diff below?
>
> $ echo ryanair.com | ./smtpctl/obj/smtpctl spf walk
> smtpctl: lookup_record: %{i}._ip.%{h}._ehlo.%{d}._spf.vali.email contains
> macros and can't be resolved
> >
> > > Is it worth mentioning in smtpctl in CAVEATS section or somewhere else ?
> >
> > Maybe in caveats, but if it's there it should be referenced in the
> > description of "spf walk" too, to make it easier to find.
> >
> > Text something like this?
> >
> > "SPF records may contain macros which cannot be included in a static list
> > and must be resolved dynamically at connection time.
> > spf walk cannot provide full results in these cases."
>
> Text reads fine to me. Added to diff below.
> While here I also changed the # to $ so not to give people the
> impression it should be run as root.
>
> OK?
>
> martijn@
>
> Index: spfwalk.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/smtpd/spfwalk.c,v
> retrieving revision 1.17
> diff -u -p -r1.17 spfwalk.c
> --- spfwalk.c 15 Mar 2020 16:34:57 -0000 1.17
> +++ spfwalk.c 14 Sep 2020 07:31:03 -0000
> @@ -118,6 +118,11 @@ lookup_record(int type, const char *reco
> struct asr_query *as;
> struct target *ntgt;
>
> + if (strchr(record, '%') != NULL) {
> + warnx("%s: %s contains macros and can't be resolved", __func__,
> + record);
> + return;
> + }
maybe escape the output before it reachs the terminal ? the string
comes from untrusted source...
> as = res_query_async(record, C_IN, type, NULL);
> if (as == NULL)
> err(1, "res_query_async");
> Index: smtpctl.8
> ===================================================================
> RCS file: /cvs/src/usr.sbin/smtpd/smtpctl.8,v
> retrieving revision 1.64
> diff -u -p -r1.64 smtpctl.8
> --- smtpctl.8 18 Sep 2018 06:21:45 -0000 1.64
> +++ smtpctl.8 14 Sep 2020 07:31:03 -0000
> @@ -247,8 +247,12 @@ Shows if MTA, MDA and SMTP systems are c
> Recursively look up SPF records for the domains read from stdin.
> For example:
> .Bd -literal -offset indent
> -# smtpctl spf walk < domains.txt
> +$ smtpctl spf walk < domains.txt
> .Ed
> +.Pp
> +SPF records may contain macros which cannot be included in a static list and
> +must be resolved dynamically at connection time.
> +spf walk cannot provide full results in these cases.
> .It Cm trace Ar subsystem
> Enables real-time tracing of
> .Ar subsystem .
>
--
Sebastien Marie
