Always-on VPN immediately changes Linphone's connection status to "Not Connected"

[twesterhever]

Hi Linphone development team! :-)

1. Describe the bug (mandatory)

Running the Linphone app on Android only works if any VPN configured with Android itself (i.e., via the internet settings) is not set up to be "always-on", i.e., established under any circumstances. As soon as any active VPN connection is configured to be "always-on", Linphone's connection status immediately changes to "not connected" (accompanied by a grey icon, rather than the usual green one). However, any other apps work fine, as does the VPN itself.

As soon as the same VPN configuration is modified to be active on demand, rather than "always-on", Linphone's status turns to "connected" again (green icon), despite no other aspect of the VPN has changed.

2. To Reproduce (mandatory)

• Install Linphone from F-Droid on an Android device running any reasonably recent (i.e., 3 months or newer) GrapheneOS.
• Set up a VoIP account in Linphone, and ensure it is working properly without any VPN configured on the device.
• Configure a VPN using Android's built-in IPsec client (tested with an IKEv2/IPsec RSA connection).
• Tick the checkbox for making the VPN an "always-on" one.
• Verify that Linphone's connection status has turned from "connected" (green) to "not connected" (grey).
• Modify said VPN connection, untick the "always-on" checkbox, and save it.
• Open Linphone again, and verify the connection status turned to "connected" (green) again.

3. Expected behavior (mandatory)

In this scenario, the Linphone app should act VPN-agnostic, and attempt to establish a SIP connection as usual, regardless if an active VPN is configured to be "always-on" or not.

4. Please complete the following information (mandatory)

• Device: Google Pixel 8a
• OS: GrapheneOS 2024102400 (running Android 15)
• Version of the App: 5.2.5 (installed via F-Droid)
• Version of the SDK: N/A
• Where you did got it from: F-Droid
• Please tell us if your Android is a Lineage OS or another variant: Yes, GrapheneOS

Thank you in advance for looking into this issue!

[Viish]

Hi @twesterhever,

I don't have a graphene OS device to test it, nor a VPN subscription.
Could you please turn on debug logs in advanced settings and reproduce the issue with VPN being "always ON" and share the logs please?
If you can also test with our 6.0 nightly snapshot from here it would be very helpful.

Thanks in advance!
Best regards,

[twesterhever]

Thank you for your quick reply.

Debug logs are ready, however, as they contain quite a lot of PII, I'm reluctant to share these here. Would a DM be suitable as well?
What sticks out, however, are these log messages when trying to use the Linphone app with the "always on" VPN enabled:

2024-11-04 15:32:23:068 [org.linphone/linphone-android] MESSAGE [Platform Helper] [Network Manager 26] Restrict background status is [DISABLED]
2024-11-04 15:32:23:069 [org.linphone/linphone-android] WARNING [Platform Helper] [Network Manager 26] Active network info says it's not connected...
2024-11-04 15:32:23:069 [org.linphone/linphone-android] MESSAGE [Platform Helper] No connectivity: setting network unreachable

If the same VPN is enabled, but not configured as being "always on", this part looks different:

2024-11-04 15:31:41:118 [org.linphone/linphone-android] MESSAGE [Platform Helper] [Network Manager 26] Restrict background status is [DISABLED]
2024-11-04 15:31:41:119 [org.linphone/linphone-android] MESSAGE [Platform Helper] [Network Manager 26] Active network info says it's connected
2024-11-04 15:31:41:119 [org.linphone/linphone-android] MESSAGE [Platform Helper] [Network Manager 26] The active network is using an http proxy: [<redacted>] <redacted>
2024-11-04 15:31:41:119 [org.linphone/linphone-android] WARNING [Platform Helper] Proxy available but forbidden by linphone core [sip] use_system_http_proxy setting
2024-11-04 15:31:41:119 [org.linphone/linphone-android] MESSAGE [Platform Helper] Active network type is VPN, state CONNECTED / CONNECTED
2024-11-04 15:31:41:120 [org.linphone/linphone-android] MESSAGE [Platform Helper] [Network Manager 26] Found DNS host <redacted> from mobile network
2024-11-04 15:31:41:120 [org.linphone/linphone-android] MESSAGE [Platform Helper] [Network Manager 26] Found DNS host <redacted> from mobile network
2024-11-04 15:31:41:120 [org.linphone/linphone-android] MESSAGE [Platform Helper] [Network Manager 26] Found DNS host <redacted> from mobile network
2024-11-04 15:31:41:120 [org.linphone/linphone-android] MESSAGE [Platform Helper] [Network Manager 26] Found DNS host <redacted> from mobile network
2024-11-04 15:31:41:121 [org.linphone/linphone-android] MESSAGE [Platform Helper] [Network Manager 26] Found DNS host <redacted> from mobile network
2024-11-04 15:31:41:121 [org.linphone/linphone-android] MESSAGE [Platform Helper] [Network Manager 26] Found DNS host <redacted> from mobile network
2024-11-04 15:31:41:121 [org.linphone/linphone-android] MESSAGE [Platform Helper] [Network Manager 26] Found DNS host <redacted> from network VPN with default route
2024-11-04 15:31:41:121 [org.linphone/linphone-android] MESSAGE [Platform Helper] [Network Manager 26] Found DNS host <redacted> from network WIFI with default route
2024-11-04 15:31:41:121 [org.linphone/linphone-android] MESSAGE [Platform Helper] [Network Manager 26] Found DNS host <redacted> from active network VPN
2024-11-04 15:31:41:122 [org.linphone/linphone-android] MESSAGE [Platform Helper] DNS servers list updated
2024-11-04 15:31:41:122 [org.linphone/linphone-android] MESSAGE [Platform Helper] Network reachability enabled

I'll try the 6.x alpha release as soon as possible and will report back.

[Viish]

Hi @twesterhever,

You can send the logs to me by email at [email protected]

Cheers,