Resolver reverse DNS brokeness?

Hi,

So I visit my website, and I later on test the resolver’s ability to reverse DNS (simply by calling it with an IP address as the input hostname and looking to see what the output hostname says (or it’ll abort with R0 = -1 if there’s no name for that IP address).

The result? The primary name for my host is “www.heyrick.co.uk” (no it isn’t, that’s a virtual host!) and the aliases are… empty.
I ping some of the other addresses associated with that IP address, and these are added in turn to the list of aliases.
All the while, it believes that heyrick is the primary name of the host (no, it isn’t). I ping the primary hostname (fi1.irrelevant.com) and that is just added to the list as an alias.

I’m going to have to reboot my machine now, as reinitialising Resolver leads to abort on data transfer (so I will need to save this message and send it afterwards).

Right, rebooted to a fresh system. It will now correctly look up the true name of the host, but has no aliases at all. On the other hand, if I look at some of the alternative hostnames, then Resolver will return those (with the first seen as the ‘primary’) without actually bothering to look up the hostname correctly.

Some code:

>SYS "Resolver_GetHost", "193.33.179.237" TO e%, h%
>PRINT e%, ~h%
        36         0
>REM 36 means still busy, try again...
>SYS "Resolver_GetHost", "193.33.179.237" TO e%, h%
>PRINT e%, ~h%
         0  201D4B34
>*Memory 201D4B34 +8

Address  :     7 6 5 4     B A 9 8     F E D C     3 2 1 0 :    ASCII Data
201D4B34 :    201D58F4    201D58D4                         : ôX. ÔX. 
>REM First word is pointer to primary name, second is pointer to alias list.
>*Memory 201D58F4 +32

Address  :     7 6 5 4     B A 9 8     F E D C     3 2 1 0 :    ASCII Data
201D58F4 :    2E316966    65727269    6176656C    632E746E : fi1.irrelevant.c
201D5904 :    05006D6F    2002113E    00000000    00000020 : om..>.. .... ...
201D5914 :    00000018    00000001    00000003    00000502 : ................
201D5924 :    000400C0                                     : À...
>REM Correct!
>*Memory 201D58D4 +32

Address  :     7 6 5 4     B A 9 8     F E D C     3 2 1 0 :    ASCII Data
201D58D4 :    00000000    FFFFFFFF    1800396C    18C03974 : ....ÿÿÿÿl9..t9À.
201D58E4 :    20000000    00000011    00000020    00000020 : ... .... ... ...
201D58F4 :    2E316966    65727269    6176656C    632E746E : fi1.irrelevant.c
201D5904 :    05006D6F                                     : om..
>REM NULL? Where's heyrick or any of the other irrelevant.com domains?

If you repeat the above on a freshly booted machine but do a…

ping SBT.heyrick.co.uk

(replace StupidBloodyTextile with “www” in the above)

beforehand, then that’s what will be returned for that IP address, not the correct (fi1…) domain.

Not a big deal really, but it does look broken…

Not a big deal really, but it does look broken…

Yup.
You might, perhaps, recall me me commenting about resolver previously. It might not be a big deal in some circumstances but reverse lookup is used for a number of things, like DNS blacklisting. Hence Frank dB. writing something to do the lookup properly for the DNSB feature in AntiSpam.

Now you know one of the reasons I keep banging on about needing to have a new resolver (and probably much of the IP stack as socket handling is a bit erm …. too)