Milter-greylist

On 2013-08-16 02:15, Emmanuel Dreyfus wrote:
> Hajimu UMEMOTO <ume@...> wrote:
>
>>   However, I'm
>> not sure if there is such implementation that changes addr on fail.
>> POSIX says only on success:
>>
>>      Upon successful completion, getnameinfo() shall return the node
>>      and service names, if requested, in the buffers provided. The
>>      returned names are always null-terminated strings.
>
> Thank you for digging that out. Let us start with assuming the standard
> are honoured, we will add workaround later if they are not.

The way I read it, the standard only determines the actions about
success, and not about failure - which is implementation-dependent
(replace the original string with the IP address number, or don't
touch the original string at all). Given that the milter-greylist
rulesets may depend on bracketed names (as mine do, to delay the
message until a later retry might have successful DNS resolution),
I think it would be portable to ensure that we do the same thing
on all platforms - by using the getnameinfo() with a temporary copy
of the string, inspecting the return code, and copying the string
into original buffer if it resolved successfully. This way we won't
have to guess later on about esoteric (or popular) platforms which
might have private quirks. This only costs a few lines of code and
about 300 bytes of temporary buffer space ;)

//Jim