Re: [Bug-mailfromd] spam getting through in 9.0 on custom module

["Sergey Poznyakoff" <gray@xxxxxxxxxx>]

Marc <Marc@xxxxxxxxxxxxxxxxx> ha escrit:

> I have this code/module[1]. It looks like this is not working any more
> since upgrading to 9.0 I have. Nothing is being matched. Any idea what
> this can be? Or maybe there is a new solution for this?

The NEWS file for version 8.17 (sic) states that:

  ** primitive_resolve and resolve functions

   string primitive_resolve (string HOST; string DOMAIN, number FAMILY)
   string resolve (string HOST; string DOMAIN, number FAMILY)

   The use of DOMAIN argument is deprecated.
   ...

Then, the documentation for primitive_resolve[1] says:

  string primitive_resolve (string host, [string domain, number family])
  ...
    If a non-empty string is given as domain, the function works as
    follows:
    ...
    [if] host is a string representation of an IPv4 address the address
    is reversed, then a dot and domainâare appended to it. Finally, the
    DNS is queried for an Aârecord of the resulting name.

    Thus,
        primitive_resolve("192.0.2.1", "rev.example.com")
    is equivalent to
        primitive_resolve("1.2.0.192.rev.example.com")

This all boils down to the following: replace the following line in
match_dnsbl_range:

    string res resolve ("\4.\3.\2.\1", zone)

with

    string res resolve (address, zone)

and it will work as expected.  Notice, however, that each call to
match_dnsbl_ret can result in up to N calls to resolve, where N is
number of variadic arguments.  Obviously this slows down your program.
Besides, as noticed above, the use of domain argument is deprecated.
The proper solution therefore would be to rewrite match_dnsbl_range as
follows:

func match_dnsbl_range(string address, string zone, string ...)
  returns number
do
  set res dns_query(DNS_TYPE_A, reverse_ipstr(address).".".zone)
  if res >= 0
    loop for set i 0,
	 while i < dns_reply_count(res),
	 set i i + 1
    do
      set a dns_reply_string(res, i)
      loop for number j 1,
	   while j < $# - @zone,
	   set j j + 1
      do
	set iprange $(j)
	if iprange = 'ANY'
	  set iprange '127.0.0.0/8'
	fi
	if match_cidr(a, iprange)
	  set dnsbl_result a
	  dns_reply_release(res)
	  return 1
	fi
      done
    done
    dns_reply_release(res)
  fi
  return 0
done

Then you can use it instead of match_dnsbl_ret

Kind regards,
Sergey

[1] https://www.gnu.org.ua/software/mailfromd/manual/Simplified-DNS-functions.html#index-primitive_005fresolve