[rbldnsd] AAAA Queries?

[Steven F Siirila]

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...

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.  :)

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