Problem with setting substring match variables (%{1} etc.)

[Enrik Berkhan]

Hi,

Alan DeKok wrote:
> Enrik Berkhan wrote:
>> Is this expected behaviour? If not, how can this be fixed? Just leave
>> out the 'break' in the for loop? (Code from valuepair.c)
> 
>   Likely, yes.
> 
>   If that works, please say so, and I'll commit a patch.  I'm a little
> overloaded right now, and can't look at it myself.

For testing, I've changed the inner 'no match or no subexpression match'
condition of the four for-loops that are currently used to update
%{0}... in the following way:

old:
>  if (r) {
>    free(r);
>    continue;
>  }
>  break;

new:
>  if (r) {
>    free(r);
>  }
>  continue;

This seems to work, variables are unset if they have an old value and no
new value (no match at all or empty) or they are set/updated if they
have a new value (match implied).

I've only tested it using unlang:

>  if ("%{User-Name}" =~ /^(a)(.)(.)/) {
>     update reply {
>       Reply-Message := "first match: 0:%{0} 1:%{1} 2:%{2} 3:%{3} "
>     }
>   }
>   else {
>     update reply {
>       Reply-Message := "no match on first regex"
>     }
>   }
>   if ("%{User-Name}" =~ /^(a|b)?(.)/) {
>     update reply {
>       # += segfaults?!
>       #Reply-Message += "second match: 0:%{0} 1:%{1} 2:%{2} 3:%{3} "
>       Reply-Message := "%{reply:Reply-Message}; second match: 0:%{0} 1:%{1} 2:%{2} 3:%{3} "
>     }
>   }
>   else {
>     update reply {
>       #Reply-Message += "no match on second regex"
>       Reply-Message := "%{reply:Reply-Message}; no match on second regex"
>     }
>   }

The for-loops to update %{0}... are currently explicitly found in

- src/main/evaluate.c
- src/main/valuepair.c
- src/modules/rlm_attr_rewrite/rlm_attr_rewrite.c (slight variation:
doesn't touch the variables on no match)
- src/modules/rlm_policy/evaluate.c

Shouldn't this be moved to a single place like a function in
src/main/util.c or main/xlat.c called xlat_update_regex or so?

Further, I've noticed that in all places where regex-no-match operators
are implemented but in src/modules/rlm_policy/evalute.c, the
subexpressions are evaluated but never used later. May this could be
fixed, too.

Of course I could provide patches for all of this or parts thereof if
it's the right direction. Just tell me what you'd prefer.

Now I'm gonna try to find out why the += segfaults in the above unlang
example ...

Enrik