Local discovery problem on Android 11

[webeule]

Hello all,

I am using the syncthing-fork for android and local discovery is not working (see also here: 735#) I have these logs when I activated beacon logs:

2020-12-29 11:44:31 Enabled debug data for "beacon"
2020-12-29 11:44:33 route ip+net: netlinkrib: permission denied
2020-12-29 11:44:33 Stopped broadcastBeacon writer: route ip+net: netlinkrib: permission denied
2020-12-29 11:44:33 broadcastBeacon: Failed service 'Service@0x40000d66c0 created by broadcastBeacon@0x4000138230/writer' (1.999843 failures of 2.000000), restarting: true, error: "{Service@0x40000d66c0 created by broadcastBeacon@0x4000138230/writer Service@0x40000d66c0 created by broadcastBeacon@0x4000138230/writer} returned unexpectedly", stacktrace: [unknown stack trace]
2020-12-29 11:44:33 Starting broadcastBeacon writer
2020-12-29 11:45:03 route ip+net: netlinkrib: permission denied
2020-12-29 11:45:03 Stopped broadcastBeacon writer: route ip+net: netlinkrib: permission denied
2020-12-29 11:45:03 broadcastBeacon: Failed service 'Service@0x40000d66c0 created by broadcastBeacon@0x4000138230/writer' (1.999810 failures of 2.000000), restarting: true, error: "{Service@0x40000d66c0 created by broadcastBeacon@0x4000138230/writer Service@0x40000d66c0 created by broadcastBeacon@0x4000138230/writer} returned unexpectedly", stacktrace: [unknown stack trace]
2020-12-29 11:45:03 Starting broadcastBeacon writer
2020-12-29 11:45:31 Exiting backoff state.
2020-12-29 11:45:31 Starting multicastBeacon writer
2020-12-29 11:45:31 Starting multicastBeacon reader
2020-12-29 11:45:31 route ip+net: netlinkrib: permission denied
2020-12-29 11:45:31 Stopped multicastBeacon writer: route ip+net: netlinkrib: permission denied
2020-12-29 11:45:31 multicastBeacon: Failed service 'Service@0x40000d6d80 created by multicastBeacon@0x40001382d0/writer' (1.000000 failures of 2.000000), restarting: true, error: "{Service@0x40000d6d80 created by

When you need more information, please let me know.

[kluppy]

It seems to be working for me on Android 11.

2020-12-29 20:54:42 sent 515 bytes to 192.168.0.255:21027 2020-12-29 20:54:42 write udp [::]:43262->[ff12::8384]:21027: sendmsg: network is unreachable on write to [ff12::8384]:21027 bond0 2020-12-29 20:54:42 sent 515 bytes to [ff12::8384]:21027 on wlan0 2020-12-29 20:54:42 write udp [::]:43262->[ff12::8384]:21027: sendmsg: network is unreachable on write to [ff12::8384]:21027 wlan1 2020-12-29 20:54:42 write udp [::]:43262->[ff12::8384]:21027: sendmsg: network is unreachable on write to [ff12::8384]:21027 p2p0 2020-12-29 20:54:42 recv 515 bytes from [fe80::b479:c9ff:fe98:1b28%wlan0]:43262 2020-12-29 20:54:58 recv 452 bytes from 192.168.0.102:35263 2020-12-29 20:54:58 recv 452 bytes from [fe80::c069:fd7f:5856:50e9%wlan0]:44536

[DrSchnagels]

Sorry for re-opening this topic!

I have suddenly this problem too after updating my OnePlus 7t Pro yesterday to Android 11. Does anyone know how to fix this? Local discovery was 2/2 before. Now it does not work anymore. I used to use only fixed IP-addresses for Syncthing in my network but i recently switch to only local discovery.

Thanks a lot!

[bt90]

Could you post the logs?

[DrSchnagels]

You can find logs in Catfriends Fork github.

Android 11 local discovery not working

For a log from me i have to find out how to get the log. The Syncthing Fork app does not show a log for Syncthing itself, only the Android log. Do i need to enable debug logs? Or detailed logs in the Syncthing App settings?

[bt90]

You can open the webinterface in the app and retrieve the logs from there

[DrSchnagels]

The log doesnt show anything like an error. Maybe i need to enable some debug info?

[imsodin (Simon)]

There’s logs in the first post. I don’t see any indication that yours should be any different. In the fork’s issue there’s a link to a golang issue with other projects observing something similar when targeting sdk30 (x/mobile: Calling net.InterfaceAddrs() fails on Android SDK 30 · Issue #40569 · golang/go · GitHub). So basically one more thing that currently wont work when targeting that. It worked for @kluppy - maybe they are using syncthing-android, which still targets sdk 29?

[Catfriend1]

I think @imsodin has covered all there to say , (again) it’s unfortunately up to Google to lower the restrictions in upcoming API levels. Not sure the golang team can do anything if the OS blocks the app to use it’s broadcasting features on Api 30.

[bt90]

So the gplay version is crippled after November? Thanks Google /s

[bt90]

I doubt that Google will change its course here. “Use the Android APIs or get wrecked” seems to be the tone over the last few Android releases.

I fear that the UI-only approach of the app won’t work anymore at a certain point in the future. That means it needs to use Android APIs directly via gomobile or via the wrapper(e.g REST calls).

Let’s just hope that i’m completely wrong.

[AudriusButkevicius]

@Catfriend1

I don’t know why they rejected it more times again for the fork and accepted it for the official app

Because @imsodin and @tomasz86 had atleast 4-5 rounds of modifying the privacy policy for it to finally be accepted.