[tor-bugs] #13213 [Tor]: Tor should tell its pluggable transports when DisableNetwork gets set/unset

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#13213: Tor should tell its pluggable transports when DisableNetwork gets set/unset
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     Reporter:  arma    |      Owner:
         Type:  defect  |     Status:  new
     Priority:  normal  |  Milestone:  Tor: 0.2.6.x-final
    Component:  Tor     |    Version:
   Resolution:          |   Keywords:  tor-pt
Actual Points:          |  Parent ID:
       Points:          |
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Comment (by yawning):

 Replying to [comment:4 dcf]:
 > It is not specified that that they do. I might argue that if they keep
 using the network, it's for a good reason. Like maybe a PT's purpose is to
 generate cover traffic so an observer can't see when your tor is idle.
 Flash proxy will break its existing WebSocket connections, but won't close
 its external listeners, for example.
 >
 > The confusion is because we're punning on different interpretations of
 "DisableNetwork". One is "drop the firewall and let nothing get out": in
 that case, tor should just kill its client PTs. The other is "make tor
 close its connections, knowing that the (PT, socket, OS) abstractions on
 which they are built may continue to operate as usual": in that case, tor
 should just close its PT connections.

 For my 2 JPY, ideally we would provide both options, with a new config
 entry for the latter definition of "DisableNetwork".  I'm in the camp that
 the first definition follows the principle of least surprise.

 > If the use case for DisableNetwork is saving battery on a mobile, then I
 think you want to kill the PT processes. Same is the use case is to be a
 poor man's firewall.
 >
 > Speaking as an implementer, I would probably rather have my program
 killed and restarted.

 This is what I am planning to do when I go and address this problem, since
 most of the bits are in place for this already (to handle shutting
 down/starting up pts on config change).

 > The same issue exists with SocksProxy. Tor can't enforce the proxy not
 to keep using the network after it has disconnected. Same with external-
 mode proxies: there's nothing you can do to them besides terminate your
 connections.

 Indeed.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/13213#comment:5>
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