On Mon, May 15, 2023 at 12:59:11PM +0200, Tim Weippert via Bird-users wrote:

Hi List,

maybe i'm doing something wrong, but if i use some quick and dirty filter on the CLI all is working as expecting:

show route where bgp_large_community ~ [(65000, 0, 1001)] show route where (65000, 0, 1001) ~ bgp_large_community

both get the expected results, show all routes with the specific community attached.

If i use it in a filter function to filter the routes out:

function filter_large(int TestID) { if ( bgp_large_community ~ [(65000, 0, TestID)] ) then { return false; } return true; }

i get "all" routes, if clause doesn't get catched.

function filter_large_V2(int TestID) { if ( (65000, 0, TestID) ~ bgp_large_community ) then { return false; } return true; }

with the V2 function i get what i want, filter out all routes with the community attached and show all the rest.

I'm a little confused here, because the first version of the if clause is used for bgp_ext_community on several functions on my setup and working as expected, only for bgp_large_community i need to switch to if clause from version V2, and only in a function?

Hi Set expressions like [...] in BIRD are static and created in parse-time. Therefore [(65000, 0, 1001)] is valid, while [(65000, 0, TestID)] is valid only if TestID is constant (like with 'define TestID = 100;'). In your case of filter_large() the TestID is a local variable, so [(65000, 0, TestID)] should fail during configuration parsing as non-constant expression. It seems it is not checked, so it is probably just evaluated TestID to zero or some random value and used that. -- Elen sila lumenn' omentielvo Ondrej 'Santiago' Zajicek (email: santiago@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."