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using System;
/*
* http://tools.ietf.org/rfc/rfc2163.txt
*
4. The new DNS resource record for MIXER mapping rules: PX
The specification of the Internet DNS (RFC1035) provides a number of
specific resource records (RRs) to contain specific pieces of
information. In particular they contain the Mail eXchanger (MX) RR
and the host Address (A) records which are used by the Internet SMTP
mailers. As we will store the RFC822 to X.400 mapping information in
the already existing DNS name tree, we need to define a new DNS RR in
order to avoid any possible clash or misuse of already existing data
structures. The same new RR will also be used to store the mappings
from X.400 to RFC822. More over the mapping information, i.e., the
MCGAMs, has a specific format and syntax which require an appropriate
data structure and processing. A further advantage of defining a new
RR is the ability to include flexibility for some eventual future
development.
The definition of the new 'PX' DNS resource record is:
class: IN (Internet)
name: PX (pointer to X.400/RFC822 mapping information)
value: 26
The PX RDATA format is:
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| PREFERENCE |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
/ MAP822 /
/ /
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
/ MAPX400 /
/ /
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
where:
PREFERENCE A 16 bit integer which specifies the preference given to
this RR among others at the same owner. Lower values
are preferred;
MAP822 A <domain-name> element containing <rfc822-domain>, the
RFC822 part of the MCGAM;
MAPX400 A <domain-name> element containing the value of
<x400-in-domain-syntax> derived from the X.400 part of
the MCGAM (see sect. 4.2);
PX records cause no additional section processing. The PX RR format
is the usual one:
<name> [<class>] [<TTL>] <type> <RDATA>
When we store in DNS a 'table1' or a 'gate1' entry, then <name> will
be an X.400 mail domain name in DNS syntax (see sect. 4.2). When we
store a 'table2' or a 'gate2' table entry, <name> will be an RFC822
mail domain name, including both fully qualified DNS domains and mail
only domains (MX-only domains). All normal DNS conventions, like
default values, wildcards, abbreviations and message compression,
apply also for all the components of the PX RR. In particular <name>,
MAP822 and MAPX400, as <domain-name> elements, must have the final
"." (root) when they are fully qualified.
*/
namespace Heijden.DNS
{
public class RecordPX : Record
{
public UInt16 PREFERENCE;
public string MAP822;
public string MAPX400;
public RecordPX(RecordReader rr)
{
PREFERENCE = rr.ReadUInt16();
MAP822 = rr.ReadDomainName();
MAPX400 = rr.ReadDomainName();
}
public override string ToString()
{
return string.Format("{0} {1} {2}",
PREFERENCE,
MAP822,
MAPX400);
}
}
}
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I'm Alphons van der Heijden, living in Lelystad, Netherlands, Europa, Earth. And currently I'm retiring from hard working ( ;- ), owning my own company. Because I'm full of energy, and a little to young to relax ...., I don't sit down, but create and recreate software solutions, that I like. Reinventing the wheel is my second nature. My interest is in the area of Internet technologies, .NET etc. I was there in 1992 when Mosaic came out, and from that point, my life changed dramatically, and so did the world, in fact. (Y)