[tor-bugs] #9998 [Tor]: resolve "localhost", "host", "hostname" and "host.localdomain" to 127.0.0.1

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#9998: resolve "localhost", "host", "hostname" and "host.localdomain" to 127.0.0.1
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     Reporter:  proper       |      Owner:
         Type:  enhancement  |     Status:  new
     Priority:  normal       |  Milestone:  Tor: 0.2.5.x-final
    Component:  Tor          |    Version:
   Resolution:               |   Keywords:  tor-relay
Actual Points:               |  Parent ID:
       Points:               |
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Comment (by proper):

 > Did you mean for this to happen on the exit node, or elsewhere?

 Not in the exit node. In the code for before DNS resolution. As soon as
 Tor gets asked "what is the IP of the localhost dns name", reply
 "127.0.0.1". Not touching any networks.

 So if DNS = localhost/hostname/[...] then "instantly reply IP 127.0.0.1"
 else do what you currently do to use Tor exit's to resolve DNS.

 > Can you explain more about the use case here?

 If you are using Tor as your default system DNS resolver, i.e. Whonix
 users, Tails users, transparent proxy users, users who made TBB their
 default browser... When you install for example
 [http://packages.debian.org/stable/web/webhttrack webhttrack], it installs
 a start menu entry. Once that start menu entry gets started it
 instructions the system "use the system's default browser and open
 http://host:8080/".

 This will fail when Tor is used as DNS resolver, because Tor does not know
 how to resolve "localhost".

 But resolving "localhost" would be simple in principle, just resolve it to
 127.0.0.1. (Not sure if simple to code.)

 Other examples include when you install a webserver (for hidden service).
 Some instructions recommend to test it using http://localhost. Visiting
 http://localhost won't work in Tor Browser, because Tor does not know how
 to resolve localhost. Would be nicer if it would tell Firefox to visit
 127.0.0.1 instead.

 > With this change, what could a user or admin do that would be hard for
 them to do today?

 It probably isn't that hard to figure out, that Tor doesn't know how to
 resolve "localhost" and correcting those url's manually. Not having this
 feature is only a minor disadvantage.

 If Tor is capable to be a (system) DNS resolver, shouldn't it be as smart
 as resolving "localhost" to "127.0.0.1"?

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/9998#comment:2>
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