TorCtl Crashes with Invalid torrc

added component::torctl owner::mikeperry priority::medium resolution::fixed status::closed type::defect version::0.2.1.24 labels

Apologies, didn't realize Flyspray would fail to include the top secret, highly advanced feature known as "line wrapping"... should have known ;)

Can you attach an example of a bad torrc that causes this?

And is ARM the software writing the torrc, or is it "user places new torrc in randomly, decides to HUP tor, and now TorCtl closes the connection"?

Anything that makes tor complain should do the trick (I already gave an example, but any invalid syntax should work). Here's the repro steps:

start tor with any valid torrc
get a TorCtl connection (in my case I'm using arm)
screw up your torrc
issue a sighup
tor dies, and TorCtl dies with the aforementioned error

arm shouldn't have anything to do with this (though I'm using it to send the reset signal.

Cheers! -Damian

(At least from Tor's side, Tor is supposed to die when you hup it and the torrc is invalid. It's better to die than let the user think the hup worked.)

Yup, realize that. The problem here is that TorCtl's death in that occurrence is messy, killing the python process using it (and in my case if curses isn't given the chance to stop nicely it leaves the user's terminal in very bad shape).

Trac:
Parent: N/A to N/A
Component: Tor - Relay to Tor - Torctl
Milestone: N/A to N/A
Keywords: N/A deleted, N/A added

There's two issues here both exhibited from the use case above...

The socket encounters a 104 error after a failed reset. I haven't managed to repro this without arm but it's trivial to fix.
A failed reset causes TorCtl to freeze. This can be repoed with a simple torctl-only use case...

start tor with a valid torrc
connect torctl
screw up the torrc (anything will do)
use torctl to send the reset signal (doing a pkill sighup won't exhibit this problem)

>>> import TorCtl
>>> conn = TorCtl.connect()
>>> conn.send_signal("RELOAD")
NOTICE[Mon Jun 13 07:29:41 2011]:Tor closed control connection. Exiting event thread.

At this point TorCtl hangs until the python process is killed. This second issue is because, in _sendImpl line 785: https://gitweb.torproject.org/pytorctl.git/blob/HEAD:/TorCtl.py#l785

we block until we get a reply which never comes since _loop hit the exception on line 683: https://gitweb.torproject.org/pytorctl.git/blob/HEAD:/TorCtl.py#l683

I've made a fix for this issue in my 'bug1329' branch which raises the TorCtlClosed to the caller: https://gitweb.torproject.org/atagar/pytorctl.git/commit/9de33409bb240d8fe50e135dfb895536dc6a45bd

In all the testing I'm throwing at it this seems to work well, however this concurrency handling is pretty confusing so scrutiny welcome. :)

Trac:
Description: Hi Mike. By issuing a sighup with an invalid torrc (my test case being to set RelayBandwidthBurst < RelayBandwidthRate) TorCtl dies in a rather unsightly way. Unfortunately I can't prevent this in arm, and if TorCtl kills the interpreter while curses is running the user's terminal is left in an especially screwed up state (requiring a reset to function again).

Traceback (most recent call last): File "/home/atagar/Desktop/arm/TorCtl/TorCtl.py", line 494, in _loop isEvent, reply = self._read_reply() File "/home/atagar/Desktop/arm/TorCtl/TorCtl.py", line 636, in _read_reply line = self._s.readline() File "/home/atagar/Desktop/arm/TorCtl/TorUtil.py", line 198, in readline s = self._s.recv(128) error: (104, 'Connection reset by peer')

[Automatically added by flyspray2trac: Operating System: All]

to

Hi Mike. By issuing a sighup with an invalid torrc (my test case being to set RelayBandwidthBurst < RelayBandwidthRate) TorCtl dies in a rather unsightly way. Unfortunately I can't prevent this in arm, and if TorCtl kills the interpreter while curses is running the user's terminal is left in an especially screwed up state (requiring a reset to function again).

Traceback (most recent call last): File "/home/atagar/Desktop/arm/TorCtl/TorCtl.py", line 494, in _loop isEvent, reply = self._read_reply() File "/home/atagar/Desktop/arm/TorCtl/TorCtl.py", line 636, in _read_reply line = self._s.readline() File "/home/atagar/Desktop/arm/TorCtl/TorUtil.py", line 198, in readline s = self._s.recv(128) error: (104, 'Connection reset by peer')

[Automatically added by flyspray2trac: Operating System: All]
Actualpoints: N/A to N/A
Status: new to needs_review
Points: N/A to N/A
Priority: minor to normal

Alright, this one looks good too.

Merged.

Trac:
Resolution: None to fixed
Status: needs_review to closed

closed

mentioned in issue #3834 (moved)

TorCtl Crashes with Invalid torrc

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