Bettercap: mac.changer error: not restoring original mac address when called more than once

[picatz]

Prerequisites

• [x] I read the README.
• [x] I am running the latest stable version.
• [x] I already searched other issues to see if this problem was already reported.
• [x] I understand I don't necessarily have to paste this Prerequisites section in the issue.

Description

mac.changer will fail to reset back to the old mac address if accidentally called twice ( maybe more? ).

Environment

• macOS

sudo bettercap
bettercap v2.0.0 (type 'help' for a list of commands)

10.0.0.0/24 > 10.0.0.37  » mac.changer on
10.0.0.0/24 > 10.0.0.37  » [23:21:49] [sys.log] [inf] Interface mac address set to d1:59:38:f4:a1:f5
10.0.0.0/24 > 10.0.0.37  » mac.changer off
[23:21:52] [sys.log] [inf] Interface mac address restored to 98:7b:f3:1e:a0:5e
10.0.0.0/24 > 10.0.0.37  » mac.changer off
[23:21:55] [sys.log] [err] Module is not running.
10.0.0.0/24 > 10.0.0.37  » mac.changer on
[23:22:00] [sys.log] [inf] Interface mac address set to e6:e0:76:22:2f:b6
10.0.0.0/24 > 10.0.0.37  » mac.changer on
[23:22:03] [sys.log] [err] Module is already running.
10.0.0.0/24 > 10.0.0.37  » mac.changer off
[23:22:05] [sys.log] [inf] Interface mac address restored to e6:e0:76:22:2f:b6
10.0.0.0/24 > 10.0.0.37  » mac.changer off
[23:22:10] [sys.log] [err] Module is not runni

Steps to Reproduce

I turn on the mac.changer module for the first time:

1. mac.changer on
   I accidentally call it again:
2. mac.changer on again
   I then decide I'm done with that.
3. mac.changer off
   But now I see that the mac address hasn't been restored properly.

Expected behavior: I would expect the second mac.changer on to error out and not cause the subsequent mac.changer off to fail to reset the mac address properly.

Actual behavior: The mac address changed in the first on was _probably_ written to a variable or something, even in the event of the error. So when the module was turned off, the mac address wasn't able to restore properly.

[picatz]

Source of Bug

I think I found the source of the bug?

So, whenever the module is ran, return mc.Start() will Configure() the MacChanger struct, effectively overwriting the "original mac" with whatever the current one is.

[picatz]

I'm working on a fix to this now / I'm sure @evilsocket or @Matrix86 could easily beat me to it. 🙏

[picatz]

🤔 This might not be perfect or anything -- but I think it'd basically solve the problem in a way without creating another function like isConfigured() or something -- which I did consider. But I think this is pretty simple. Maybe I need to sleep on it / open to whatever of course!

Commit

https://github.com/picatz/bettercap-ng/commit/69d5cc574f9947bb3b2b1408fe7613eb75e8bc76

[evilsocket]

Yay, congrats for the PR :D

[evilsocket]

Did a quick refactor :)