Strange bgp_ext_community.add behaviour

[Ondrej Zajicek]

On Thu, Jul 03, 2014 at 01:41:33PM +0300, Alexander Shikov wrote:
> Hi!
> 
> On Thu, Jul 03, 2014 at 12:48:04PM +0200, Ondrej Zajicek wrote:
> > This is expected, as .add argument may be a (e)clist, but not a (E)C set,
> > and  [ (ro,MyASN,10856), (ro,MyASN,3) ] expression is an EC set.
> Hm... Now I'm confused.
> "clist is similar to a set"
> I understand that as I can define eclist variable in a similar way:
> eclist var;
> var = [ ... ];
> 
> I tried that:
> filter Reject_Static
> eclist cmn;
> {
>         cmn = [ (ro,MyASN,10856), (ro,MyASN,3) ];

This is the same problem - assigning EC set value to eclist variable.

> "print cmn.len" does not print anything neither in syslog nor in stderr,
> when running with -d switch.

Seems like you have missing all log messages from filters. What your
'log' config option looks like?

> >From my point of view, expressions like
> bgp_community.add( [] )
> bgp_ext_community.add( [] )
> should treat arguments like (e)clist. It would be more logical.

Unfortunately with the way how the filter language is implemented,
expressions are interpreted independently of the context and the
'[...]' expression is just a set expression.

> > But it should report error during filter:
> > bird: filters, line 169: Can't add set
> 
> It does not reports anything. Moreover, if change [] brackets with ()
> brackets:
> cmn = ( (ro,MyASN,10856), (ro,MyASN,2) );
> ... there is no syntax error, but it should be?

You can enclose any expression with () brackets, it does not change
its meaning, . It is like 2+2 vs (2+2).

-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."
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