Bluetooth: Cannot receive files

[asdf19293919239]

# Use case

Ubuntu 17.04, quite fresh installation, updated.

Bluetooth file transmission

I want to send files to my smartphone, and receive files sent by my smartphone via bluetooth. I pair both devices, initiate file transfer from one of the devices, and the other device asks me what to do.

# Problems

This is a mix from usability and technical issues.

1. OBEX disabled (bug 1645631)

The bluetooth file transmission service OBEX was not started. I started and enabled OBEX:
`systemctl --user start obex`
`systemctl --user enable obex`

```
Mai 30 14:47:55 tp systemd[1661]: Starting Bluetooth OBEX service...
Mai 30 14:47:55 tp obexd[8168]: OBEX daemon 5.43
```

2. OBEX silently fails (this bug)

After having OBEX enabled, I was able to transmit files from laptop to smartphone, yet I could not receive files on the laptop. In the system log, you could see that OBEX fails (please note `FORBIDDEN`):

```
Mai 30 14:47:55 tp obexd[8168]: OBEX daemon 5.43
Mai 30 14:48:04 tp obexd[8168]: CONNECT(0x0), (null)(0xffffffff)
Mai 30 14:48:04 tp obexd[8168]: CONNECT(0x0), (null)(0x0)
Mai 30 14:48:04 tp obexd[8168]: PUT(0x2), (null)(0xffffffff)
Mai 30 14:48:04 tp obexd[8168]: PUT(0x2), FORBIDDEN(0x43)
Mai 30 14:48:04 tp obexd[8168]: DISCONNECT(0x1), (null)(0xffffffff)
Mai 30 14:48:04 tp obexd[8168]: DISCONNECT(0x1), SUCCESS(0x20)
Mai 30 14:48:04 tp obexd[8168]: disconnected: Transport got disconnected
```

I did not receive a popup notification asking me to receive the file or not.

In the file sharing preferences `gnome-file-share-properties`, there is a setting to automatically receive files via bluetooth. With this box checked, you're finally able to receive files from your smartphone.

Successful log for comparison:
```
Mai 30 14:55:50 tp obexd[8168]: CONNECT(0x0), (null)(0xffffffff)
Mai 30 14:55:50 tp obexd[8168]: CONNECT(0x0), (null)(0x0)
Mai 30 14:55:50 tp obexd[8168]: PUT(0x2), (null)(0xffffffff)
Mai 30 14:55:50 tp obexd[8168]: PUT(0x2), CONTINUE(0x10)
Mai 30 14:56:28 tp obexd[8168]: DISCONNECT(0x1), (null)(0xffffffff)
Mai 30 14:56:28 tp obexd[8168]: DISCONNECT(0x1), SUCCESS(0x20)
Mai 30 14:56:28 tp obexd[8168]: disconnected: Transport got disconnected
```

# Expected behaviour

OBEX is started by default to handle bluetooth file transfers.

If no automatic file receipt is configured, a popup notification asks me if I want to receive the file or not.

If this is not possible, there should be a notification pointing the user to the configuration.

[asdf19293919239 (asdf19293919239)]

Related:
https://bugs.launchpad.net/ubuntu/+source/bluez/+bug/1645631
https://bugs.launchpad.net/ubuntu/+source/gnome-bluetooth/+bug/1687194
https://bugs.launchpad.net/ubuntu/+source/gnome-bluetooth/+bug/1645631

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

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[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Daniel van Vugt (vanvugt)]

Per the description:

1. OBEX disabled

This part is bug 1645631, so please remove part #1 of the description and just mention bug 1645631 instead.

2. OBEX silently fails

Let's make #2 the focus of this bug, so it is not seen as a duplicate of bug 1645631

[Alban Browaeys (prahal)]

Staying on gnome-control-center bluetooth pane while receiving file works too.
When so dbus session show it registers itself to obexd RegisterAgent with '/org/gnome/share/agent'.
As soon as we exit the gnome-control-center bluetooth pane it unregister itself and stop advertising itself as org.bluez.obex.Agent1 on the dbus session bus.
obexd thus fails as no agent is available.

part 2 is https://bugs.launchpad.net/ubuntu/+source/gnome-bluetooth/+bug/1645631 though me might want to keep it there as there are 4 different issues in this previous report. My test shown that when I was with an agent the file goes temporarily to $HOME/.cache/obexd/<random name> then to the Downloads folder. So I do not confirm the bug reports 1645631 findings.
This refutes the root folder is not correct issue (dbus monitor shows the same cache dir with or without an agent).

gnome-file-share-properties is still available in gnome-user-share on ubuntu. As you shown it registers itself and stays available to the obex server obexd. So it is a correct workaround. But it might go away like it did in debian. A fix upstream is more than wanted. Mostly an agent that runs session wide not gnome-control-center a bluetooth pane that is never active except when pairing.

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.
Ubuntu 17.04 (zesty) reached end-of-life on January 13, 2018.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test.

If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in and change the bug status to Confirmed.