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Duane Wessels
wessels at packet-pushers.com
Mon Apr 14 23:07:22 UTC 2008
> Is there an application that treats a local file specifier and a host
> specifier indistinguishably? If so, how does it deal with strings (like those
> I listed above) that could potentially be executables as well as domain
> names?
Looking at the 2007 DITL data (traces from DNS roots) its interesting
to see traffic for invalid TLDs that look just like filename
extensions. For example:
% of all TLD/
Queries extension
---------- -----------
0.182 txt
0.055 htm
0.051 c
0.049 lib
0.041 jpg
0.026 gif
0.012 html
0.011 php
0.005 exe
(Note, those really are percentages.)
I have no idea what applications are behind them, but it indicates
that there is software out there that has a hard time telling the
difference between a filename and a hostname. Or maybe its (ab)using
the DNS to help make the decision.
FWIW I was able to find one application, the text browser 'links,'
which accepts either filename or hostnames as its commandline
argument. From what I can tell its algorithm is something like
this:
- if tld/extension has two letters --> URL
- if less than two letters --> File
- if tld/extension is in list of known gTLDs --> URL
- else --> File
DW
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