Help testing if a variable contains an IPv4

[David Herselman]

Hi,

I'm trying to allow non MFA logins from configuration revisioning systems where the target device doesn't support SSH key based authentication. I started constructing an unlang check using '<ipv4prefix>' and hit some quirks.

Most of our devices include the calling station's source IP in their request, whilst a few send the reverse DNS lookup strings. How do I test if a variable matches the structure of an IPv4 IP?

My problem appears to be that '<ipv4prefix>&String  < 41.0.0.0/29' returns true, for example:

(0)   Calling-Station-Id = "oxidized.syrex.co.za"
(0)       if (&Client-Shortname == "core_routers") && !(&User-Name == "revisioncfg" && &Calling-Station-Id && <ipv4prefix>&Calling-Station-Id < 41.0.0.0/29) {
(0)       EXPAND &Client-Shortname
(0)          --> core_routers
(0)       if (&Client-Shortname == "core_routers") && !(&User-Name == "revisioncfg" && &Calling-Station-Id && <ipv4prefix>&Calling-Station-Id < 41.0.0.0/29)  -> FALSE

(1)   Calling-Station-Id = "196.196.196.196"
(1)       if (&Client-Shortname == "core_routers") && !(&User-Name == "revisioncfg" && &Calling-Station-Id && <ipv4prefix>&Calling-Station-Id < 41.0.0.0/29) {
(1)       EXPAND &Client-Shortname
(1)          --> core_routers
(1)       if (&Client-Shortname == "core_routers") && !(&User-Name == "revisioncfg" && &Calling-Station-Id && <ipv4prefix>&Calling-Station-Id < 41.0.0.0/29)  -> TRUE


I had hoped to have been able to do the following, but the behaviour above makes me believe I have to test them separately:

if (&Client-Shortname == "core_routers") && !(&User-Name == "revisioncfg" && &Calling-Station-Id && (&Calling-Station-Id =="oxidized.syrex.co.za" || <ipv4prefix>&Calling-Station-Id < 41.0.0.0/29))


Regards
David Herselman