StopSnowflakeProxy() doesn't work

[bitmold]

I noticed that calling this function in (at lesat) IPtProxy 1.4.0 doesn't do anything, you still get events:

2022-02-10 00:24:13.218 5890-5962/com.example.testsnowflakeproxy E/GoLog: 2022/02/10 05:24:13 NAT type: restricted
2022-02-10 00:24:16.078 5890-5962/com.example.testsnowflakeproxy E/GoLog: 2022/02/10 05:24:16 NAT type: restricted

func StopSnowflakeProxy() {
    if snowflakeProxy == nil {
        return
    }

    go func() {
        snowflakeProxy.Stop()
        snowflakeProxy = nil
    }()
}

The null assignment here does work, since you can then invoke StartSnowflakeProxy()

however this loop never seems to end:

for ; true; <-ticker.C {
        select {
        case <-sf.shutdown:
            return nil
        default:
            tokens.get()
            sessionID := genSessionID()
            sf.runSession(sessionID)
        }
    }
    return nil

[bitmold]

I'm not sure if this is an issue in IPtProxy or snowflake itself

[bitmold]

If you update snowflake to 2.1.0 https://github.com/tladesignz/IPtProxy/pull/20 this bug still exists too

[bitmold]

This was an issue in IPtProxy, by nil'ing the SnowflakeProxy pointer outside and after the goroutine IPtProxy behaves correctly.

The latest commit in that pull request fixes this bug. In the PR I made the patch to 2.1.0 as a means of testing to see if the bug goes away and for my own experimentation. I've only tested the proxy side of things with that patch too, not the snowflake client. So if you just want this bug to go away and do the patching your own way, you can cherry-pick the last commit from that branch.

For simple testing with an IPtProxy.aar file and what's hosted on jitpack.io you can use https://github.com/bitmold/TestSnowflakeProxy

[bitmold]

@n8fr8 This effects Orbot too, we need to bump Orbot once this gets fixed

[tladesignz]

Fixed with bd61f76a5e234be08f49a648f7ce76cb0dfe07d0. Thanks a lot for catching this!