[rbldnsd] AAAA Queries?

[Amos Jeffries]

----- Original Message ----- 
From: "Steven F Siirila" <sfs at tc.umn.edu>
To: "Small Daemon for DNSBLs" <rbldnsd at corpit.ru>
Sent: Saturday, July 29, 2006 4:39 PM
Subject: Re: [rbldnsd] AAAA Queries?


> On Sat, Jul 29, 2006 at 04:25:19PM +1200, Amos Jeffries wrote:
>> ----- Original Message ----- 
>> From: "Steven F Siirila" <sfs at tc.umn.edu>
>> To: "Small Daemon for DNSBLs" <rbldnsd at corpit.ru>
>> Sent: Saturday, July 29, 2006 5:54 AM
>> Subject: Re: [rbldnsd] AAAA Queries?
>>
>>
>> >On Fri, Jul 28, 2006 at 01:49:05PM -0400, Victor Duchovni wrote:
>> >>On Fri, Jul 28, 2006 at 12:41:33PM -0500, Steven F Siirila wrote:
>> >>
>> >>> We are currently using this snippet to query DNSbls.
>> >>> We do not yet run IPv6 though, so it shouldn't be an issue anyways.
>> >>>
>> >>> #define UC(b)   (((int)b) & 0xff)       /* converts char to int 
>> >>> (0-255)
>> >>> */
>> >>>
>> >>> /*
>> >>>  * dnsbl - read DNS block list data
>> >>>  */
>> >>> struct hostent *
>> >>> dnsbl(char *domain, in_addr_t ipaddr)
>> >>> {
>> >>>     char *cp;                           /* general purpose */
>> >>>     char hbuf[MAXHOSTNAMELEN];          /* temporary host name buffer
>> >>> */
>> >>>     struct hostent *hp;                 /* host node pointer */
>> >>>
>> >>>     cp = (char *)&ipaddr;
>> >>>     sprintf(hbuf, "%d.%d.%d.%d.%s",
>> >>>             UC(cp[3]), UC(cp[2]), UC(cp[1]), UC(cp[0]), domain);
>> >>>     if (debug) {
>> >>>         errmsg("Querying %s", hbuf);
>> >>>     }
>> >>>     if ((hp = gethostbyname(hbuf)) == NULL && h_errno == TRY_AGAIN) {
>> >>>         errmsg("Temporary error querying %s", domain);
>> >>>     }
>> >>>     return(hp);
>> >>> }
>> >>
>> >>This code is wrong, it will make queries for "IP.RBL.<parent_domain>" 
>> >>for
>> >>each domain on your search list. It will on IPv6 capable systems make
>> >>"AAAA" queries, ... It is not capable of reading the corresponding TXT
>> >>record. Rewrite using res_init(3), res_search(3), ...
>> >
>> >Granted, it is not ideal.  It should probably be changed.  But until 
>> >there
>> >is a real need to, it's not going to happen due to other time 
>> >commitments.
>> >
>> >We don't use TXT records either, we write a custom 550 5.7.1 message 
>> >with
>> >a URL containing encrypted data, allowing the sender to initiate a 
>> >three-
>> >way handshake process, etc...
>>
>> Which is in itself not the correct way of doing things. !!
>
> By whose definition of correct?  The way we do things has proven to be
> immensely helpful and takes the mail administrator out of the loop.
> If the remote user follows the URL, they are given the opportunity to
> have an explanation e-mailed to the originator address which they used
> (not an address of their choice) -- which is obtained from the encrypted 
> URL.
> In this explanation they are told why they were blocked and how to request
> a block exception from their intended recipient.  This has been in use 
> since
> 2002 and has been very successful here at the University of Minnesota.

Ah, at firstread it sounded like you were discarding the original TXT 
record, that's what I have problems with.
If your only adding local help to it I have no argument against it.

>
>> The whole point of the TXT field in RBL is to provide a way for the 
>> sender
>> to know why their email did not get through.
>
> We provide a lot more, including a URL to the RBL site, in the above.
>
>> The biggest problem I have as an I/ESP is the number of other providers 
>> who
>> re-write the 554 (gmail.com being the most annoying with "554 Delivery
>> failed"). Simply locating the fault in the delivery chain is vastly
>> complicated, since its usually done over the phone to a non-tech.
>>
>>
>> >
>> >Thanks for the tips!  BTW, I'm an old-timer when it comes to C coding
>> >(1991).
>> >
>> >P.S. I hate HTML-only e-mail with a passion as well.  :)
>> >
>> >-- 
>> >
>> >Steven F. Siirila Office: Lind Hall, Room 130B
>> >Internet Services E-mail: sfs at umn.edu
>> >Office of Information Technology Voice: (612) 626-0244
>> >University of Minnesota Fax: (612) 626-7593
>> >_______________________________________________
>> >rbldnsd mailing list
>> >rbldnsd at corpit.ru
>> >http://www.corpit.ru/mailman/listinfo/rbldnsd
>> >
>>
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>
> -- 
>
> Steven F. Siirila Office: Lind Hall, Room 130B
> Internet Services E-mail: sfs at umn.edu
> Office of Information Technology Voice: (612) 626-0244
> University of Minnesota Fax: (612) 626-7593
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