[Rspamd-Users] spamassassin meta support

[Vsevolod Stakhov]

On 15/01/2020 20:56, Steve Sturges (ststurge) via Users wrote:
> Hi-
> 
> I’ve been playing around with rspamd and have a question about the spamassassin plugin…
> I have a few meta rules that are of two different forms:
> 
> meta X (Z - Y) > 0.1
> meta D (A +  0.25 * B + 0.5 * C) >= 1
> 
> When I load them into rspamd using the spamassassin plugin, they are not parsing properly, and I get an error “Cannot parse expression
>  (Z - Y) > 0.1“ and “Cannot parse expression (A+ 0.25 * B + 0.5 * C) >= 1” respectively.
> 
> Near as I can tell from the code, with the 1st form, the plugin and expression parser does not handle the - as an arithmetic operator the same way it does with +.  Is this accurate?  Are there alternatives in converting the meta expressions?  Or plans to add support for this in the future?
> 
> For the 2nd example, I have tried swapping the order, making it (A + B * 0.25 + C * 0.5) >= 1, but still get an error.  Step through the debugger, the error message comes back as “Cannot parse atom: callback function failed to parse ‘.25 + C * 0.5) >= 1’”, which implies that the combination of addition and multiplication as part of the expression itself is not working as I expect.
> 
> Any suggestions from people who have migrated from spamassassin to rspamd?
> 
> Thanks!
> 

These operations (specifically `-` and `*`) have never been implemented
because there was no particular need in them. In theory, such a support
is more or less trivial to add (but AST local optimisations might
require some changes). The question is if they are really useful? I can
not see any useful appliances of them to be honest.