Re: Relay Checker Plugin (code review please?)

[John Rudd]

Stuart Johnston wrote:
John Rudd wrote:


2) This sort of replaces the other set of rules I created, that did 
this with metarules instead of a plugin.  This made some of the checks 
less useful.  You probably don't need to use both methods.

So, what is the point of doing this as a plugin instead of using 
existing rules?  The obvious disadvantage is the additional dns lookups.

The advantages are:

a) being sure that the hostname in RDNS points back to the IP address 
you started with.  Thus detecting forgeries (which shouldn't happen with 
_any_ legitimate service)

b) just using the rules version of what I wrote, you can only check if 
the decimal IP address, in individual segments, is in the hostname.  You 
can't check if the entire decimal IP address (one large number) is in 
the IP address, nor can you check if the hexidecimal segments are in the 
hostname.


(a) requires more DNS work, yes.  (b) does not.  It just requires a bit 
more math.