Tor broken by ntp

[paskao]

When ntp update the time can broke the tor circuits connections, and tor must be restarted. But we havent a user-friendly way to do that.

This is what is output in the tor log:
root@freepto # tail -n 2 /var/log/tor/log
Jun 14 20:05:55.000 [warn] Problem bootstrapping. Stuck at 80%: Connecting to the Tor network. (Network is unreachable; NOROUTE; count 15; recommendation warn)
Jun 14 18:06:21.000 [notice] Your system clock just jumped 7199 seconds backward; assuming established circuits no longer work.

[ghost]

A quick way to provide a user-friendly way to do that, could be add a new menu category (eg: services) and add something like: "tor restart" (that basically execute: "sudo /etc/init.d/tor restart")

[boyska]

We investigated a bit, and probably the "right" way to do it, is adding
an hook into NetworkManager.d/dispatchers (can't remember the exact
name).
You can also look at tails code to see what they do (which is much more
complicated than just a restart!)

boyska

[boyska]

Paskao will do this

[boyska]

in ff66f67 it works for me. I did the following test:

date -s  "2 days ago"
service tor restart
curl -i ifconfig.me
service ntp restart
curl -i ifconfig.me

Notice that:

• just disconnecting and reconnecting from the network is not enough: time will not come back up to date. Therefore I invoke ntp restart
• in /var/log/tor/log it appears that the tor daemon correctly notice that time has shift, and regenerate the circuit automatically

[boyska]

@paskao : while I know that the bug you report is true and is grave and should be fixed, there seems to be no clear way to reproduce it. Can you help us in reproducing it?

[boyska]

See be59f6e at boyska/129-fix-tor-ntp

[boyska]

I removed the testing-needed label, as it can be confusing. That's the current situation:

• There seems to be a fix, but it has not been merged
• Such a fix is pointless if it cannot be tested, and the bug reproduced
• A wiki page should be written documenting how to reproduce the bug on a "old" freepto
• It should be tested that the bug does not happen anymore

[boyska]

I managed to reproduce it! It is documented in https://we.riseup.net/freepto-wiki/tor-ntp . The script that make tor fails is http://paste.debian.net/125967/

[boyska]

Postponed to v1.1, as v1.0 is already too late