Sync requires validated Internet connection

[AntiSol]

Hi, I'm trying to use davx5 to sync my carddav and caldav contacts (both on the same server, running radicale) and calendar with my de-googled Android 10 device. I was reading in the documentation that running without google play services is one of davx5's supported use cases. I am trying to use it with the fossify calendar and contacts applications.

When I try to set up my account everything works fine, up until it actually adds the accounts. After probing the server and finding my calendar and address book, I get a notificaiton telling me that I need to enable google play services:

Davx5 says that the account has been added, but:

• When I press the 'sync' button in davx5, nothing seems to happen (and I see no activity in my server logs)
• The davx5 address book is not added in the 'accounts' section of my android settings. If I try to add one, I get the same notification again.
• Pressing 'sync' in the accounts section in android settings doesn't seem to do anything (and I see no activity in my server logs)
• My CalDav account shows up in the fossify calendar, but when I try to sync it from the fossify app, nothing happens (and I see no activity in my server logs).
• Adding a new calendar entry or contact is not synced back to my server.

I also have these accounts set up using davx5 on my older device, running lineageos 14. I have been using this for many years without any problem. Is there some trick to making it work on this Android 10 device without enabling google play services?

Thanks very much for your time (and for davx5)!

[ArnyminerZ]

Hi, some questions.

and I see no activity in my server logs

If you are synchronizing with Google, how can you see server logs? How have you configured it? Have you followed our guide?

If you are not actually trying to sync with Google's servers, what server are you using? Have you installed the app from F-Droid or directly from GitHub? If you are using an alternative client for Play Store such as Aurora, we cannot guarantee that everything is going to work fine.

Sorry for asking so many questions, but this popup is a bit strange 😅

[AntiSol]

Thanks for getting back so quickly.

I am not trying to synchronise with google. As I mentioned I'm trying to synchronise with my radicale server.

I configured it in the same way as I configured the lineageos14 device which has been talking to that server for years without incident: I pointed davx5 at the appropriate url and entered credentials, and davx5 probed the server with a bunch of OPTIONS and PROPFIND requests, and found the carddav and caldav services, and then popped up this message and refused to sync.

I installed both davx5 and the fossify calendat/contacts apps from f-droid. I am not using an alternative google store, just f-droid.

I have disabled (but not yet removed) many google services including google play services. Note that I am not able to disable the google contacts app (I think because it's ap app, not a service? it only has 'force stop' as an option, not 'disable'), but I have disabled the google calendar app. I have not disabled the 'contacts storage' or 'calendar storage' services, pehaps i should disable those?

[AntiSol]

I have not disabled the 'contacts storage' or 'calendar storage' services, pehaps i should disable those?

Disabling these is bad - makes the contacts and calendar entries stored on the phone disappear.

[ArnyminerZ]

As I mentioned I'm trying to synchronise with my radicale server.

Sorry, I misread that.

I am not able to disable the google contacts app

That's strange, I have disabled it on my google-services-phone. But shouldn't cause any problems.

Mmmh that's really strange. Please, can you provide some debug information as shown here. It should be enough if you enable "detailed logging" from the settings, try running the synchronization again, and share the logs with debug information sharing (the first option in settings). That should give you a zip file that you can share here.

Tip

Maybe email it to yourself and attach it here?

You can obfuscate of course any personal information, or if you are not comfortable sharing details here, use the form on our website. We can further help there.

[sunkup]

I am on graphene os (+sandboxed gapps) and started seeing the message myself some days ago. I am not sure whether DAVx5 is triggering the Google Contacts Sync, but for me the actual DAVx5 contacts sync works fine - so I simply disabled the annoying notification. I could probably debug this with my phone ... if I find out how to reenable the notification 😅

[AntiSol]

no problem, I'll give it another shot tomorrow and probably send a log via the support form. thanks.

[AntiSol]

logs submitted via support form, thank you.

[AntiSol]

Looks as if Android's job scheduler had a problem. (Although I don't know why it then runs the service detection jobs.)

Is that running in a different task/app to Davx5? If so, what will the task be? maybe it's just being blocked by my firewall. I've allowed internet access to davx5 but if the sync job is running under some other task it may not have internet access.

What is an "A-gold Titan" device? Is Titan_EEA_20221117 a custom ROM? Maybe it's related to that.

It's the stock Android 10 OS on a Unihertz Titan, not a custom ROM, though as I mentioned I've de-googled it by disabling many google services. But if it was related to that and the same thing is running both the service detection job and the sync job then I would expect the service detection job to not run.

[rfc2822]

Is that running in a different task/app to Davx5?

Runs in a DAVx5 process – the JobScheduler starts a JobService service handled by WorkManager to do the work.

If so, what will the task be? maybe it's just being blocked by my firewall. I've allowed internet access to davx5 but if the sync job is running under some other task it may not have internet access.

Can you disable all firewalls and other settings that may block synchronization and try again?

[AntiSol]

Can you disable all firewalls and other settings that may block synchronization and try again?

Doing so would allow other unknown/untrusted processes access to the internet. I see lots of attempted access from all kinds of things that are untrusted and which should not be talking to the internet (e.g messaging, and also "unknown"). For this reason I am very hesitant to completely disable the firewall and would stongly. prefer a whitelist-only approach.

The firewall I'm using is AFWall, which allows me to block/allow each app. I have enabled access for davx5 over both wifi and cellular. If there's some other app which I need to grant access for, and you can let me know what that is, I'll be happy to try it. But allowing unrestricted network access once is all it would take for one of these untrusted / unknown things to compromise the device.

[rfc2822]

I understand, but on the other side, if you disable Android functions with some extra firewall, it's possible that things break and then cause extra work.

Also I have found something: the sync worker requires a working (validated) Internet connection:

davx5-ose/app/src/main/kotlin/at/bitfire/davdroid/sync/worker/SyncWorkerManager.kt

Line 82 in f69533b

.setRequiredNetworkType(NetworkType.CONNECTED) // require a network connection

So if your firewall blocks the Internet detection of JobScheduler (usually done by some request to some static Google or vendor host like https://android.stackexchange.com/questions/134963/change-the-server-that-android-uses-for-an-internet-connectivity-check), sync jobs won't be run.

I think giving Internet access to uid 1000 should solve it. Otherwise you have to experiment and set up your firewall so that it allows the Android function "validate connections" to work again.

However I wonder if you don't get the "No Internet access" message in DAVx5 main screen like in #245? This should appear when there's no working connection and warn that syncs may not run.

See also: #990

[AntiSol]

I do get that message. I've seen it in other programs, too. I had assumed that davx5 would be trying a connection anyway like other software does, if it's not trying because it thinks there's no internet then that would explain why it's not working - I have not allowed access to those google IPs used for checking internet.

I'll play around some more and see about enabling access to uid 1000 (this is one of the 'unknown' ones, and it hits many google IPs, so I'm hesitant to give it access) and see how that works. But I think this is probably the solution.

IMO davx5 should consider trying to connect regardless of whether the system considers itself to have internet access, since that test is based on broken assumptions and doesn't actually check what it purports to check (i.e it's actually checking whether it can access certain google IPs, which is quite a different thing to "do I have internet?", and also note that this is itself a distinct question from "can I access the configured dav server?" e.g I might be connected to a LAN where there is a caldav/carddav server, but not wider internet - by assuming that "internet" and "access to the configured caldav server" are equivalent you are limiting the use cases for davx5).

Maybe it makes sense for this to be an optional behaviour, I can see it might e.g save battery to not attempt connections. I thought I saw an option in there to not require an internet connection? (yeah, "VPN requires underlying internet". I guess maybe that's only if you're using a VPN connection? I have it turned off in my settings)

[rfc2822]

This is a very old discussion and I think we should support the special use case for 0,1% of the people who want to synchronize "without connectivity" (in Android terms), hence #990.

However until then – the warning even appears… how can we make it more clear what it means? Apparently it's not immersive enough to make affected people notice it.

[AntiSol]

I'm glad to know that we're on the same page WRT supporting this use case! :)

it's not that it's not immersive enough or that we don't notice it, it's that the common practice for all other software on my device is to attempt to connect anyway, even though the operating system thinks there is no connectivity, leading me to expect that behaviour from davx5. For example brave shows me a warning telling me that there's no connectivity, and then immediately loads the page. I've seen similar behaviours in a couple of other programs, too, but I don't remember which ones right now.

I think as an interim measure the wording of the message could be made more explicit - i.e if the warning included information advising that "davx5 will not attempt to synchronise while the operating system reports 'no connectivity'", then it would have been immediately obvious to me what was going on. The issue is that davx5 is doing things differently to most other software out there (which tends to try to connect anyway) and also not quite making it clear that this is what is happening :)

I was able to get it to sync by allowing uid -1000, which also got rid of the 'no connectivity' icon in the os. Thanks for your help!

[rfc2822]

For curiosity: which background sync software always connects, regarding of the network status? I had a quick look and for instance Thunderbird / K-9 mail seems to require a network connection as well:

https://github.com/thunderbird/thunderbird-android/blob/805a4e86b30e8d7f5239cf6ab4600e34880ace2c/legacy/core/src/main/java/com/fsck/k9/job/MailSyncWorkerManager.kt#L35

Would be especially interesting as there come many difficulties with it, for instance how to distinguish acceptable I/O (for instance, because a WiFi network is connected, but not logged in / in a validated state) errors from "real" I/O errors that should cause a notification.

Also I can imagine that Android doesn't provide network connectivity in doze modes, and jobs that don't require network connectivity would be run, but can't sync. But to find out all these things there's #990.

"davx5 will not attempt to synchronise while the operating system reports 'no connectivity'"

The current message is "Synchronization may not be run" to keep it short.