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From:   Barry Byford <31baz66@gmail.com>
Date:   Tue, 21 Jul 2020 22:38:59 +0100
Message-ID: <CAAu3APZ_SqZniWRsp68cKtnjUoP2u3Sx8j2esDDj7cM65rksEw@mail.gmail.com>
Subject: Networking - NetworkServer1
To:     Bluez mailing list <linux-bluetooth@vger.kernel.org>
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Sender: linux-bluetooth-owner@vger.kernel.org
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I am trying to get Bluetooth networking to happen between a couple of
Raspberry Pi's running the latest Raspberry Pi OS and BlueZ 5.50

$ uname -a
Linux raspberry 4.19.118-v7+ #1311 SMP Mon Apr 27 14:21:24 BST 2020
armv7l GNU/Linux
$ bluetoothctl --version
bluetoothctl: 5.50

I have been able to use the Network1 interface to Connect to my
Android phone using Bluetooth tethering.

However, when I use the NetworkServer1 interface to register a profile
I have not had success in getting two devices to communicate. I have
paired and trusted the two devices. This allows the Bluetooth to
connect but not for the networking interface to be created as can be
seen in the logs:

e.g. bluetoothd: BNEP server cannot be added

A search for that error message didn't seem to turn up anything actionable.

```
> ACL Data RX: Handle 11 flags 0x02 dlen 44                                           #50 [hci0] 21:54:01.130545
      Channel: 64 len 40 [PSM 15 mode 0] {chan 0}
      BNEP: Control (0x01|0)
         Filter MultAddr Set (0x05)
           Length: 0x0024
           ff:ff:ff:ff:ff:ff - ff:ff:ff:ff:ff:ff
           33:33:00:00:00:01 - 33:33:00:00:00:01
           01:00:5e:00:00:01 - 01:00:5e:00:00:01
< ACL Data TX: Handle 11 flags 0x00 dlen 8
               #51 [hci0] 21:54:01.131140
      Channel: 64 len 4 [PSM 15 mode 0] {chan 0}
      BNEP: Control (0x01|0)
         Filter MultAddr Rsp (0x06)
           Rsp msg: Operation Successful(0x0000)
> ACL Data RX: Handle 11 flags 0x02 dlen 56                                           #52 [hci0] 21:54:01.131800
      Channel: 64 len 52 [PSM 15 mode 0] {chan 0}
      BNEP: Control (0x01|0)
         Filter MultAddr Set (0x05)
           Length: 0x0030
           ff:ff:ff:ff:ff:ff - ff:ff:ff:ff:ff:ff
           33:33:00:00:00:01 - 33:33:00:00:00:01
           01:00:5e:00:00:01 - 01:00:5e:00:00:01
           33:33:ff:d1:14:7e - 33:33:ff:d1:14:7e
< ACL Data TX: Handle 11 flags 0x00 dlen 8
               #53 [hci0] 21:54:01.131912
      Channel: 64 len 4 [PSM 15 mode 0] {chan 0}
      BNEP: Control (0x01|0)
         Filter MultAddr Rsp (0x06)
           Rsp msg: Operation Successful(0x0000)
> HCI Event: Number of Completed Packets (0x13) plen 5                                #54 [hci0] 21:54:01.132894
        Num handles: 1
        Handle: 11
        Count: 2
> HCI Event: Number of Completed Packets (0x13) plen 5                                #55 [hci0] 21:54:01.135075
        Num handles: 1
        Handle: 11
        Count: 2
= bluetoothd: bnep: Can't add bnep0 to the bridge tether: No such
device(19)                     21:54:01.138304
= bluetoothd: BNEP server cannot be added
                          21:54:01.138429
> ACL Data RX: Handle 11 flags 0x02 dlen 89                                           #56 [hci0] 21:54:01.158957
      Channel: 64 len 85 [PSM 15 mode 0] {chan 0}
      BNEP: Compressed Ethernet DestOnly (0x04|0)
         dst 33:33:00:00:00:16 [proto 0x86dd]
        60 00 00 00 00 24 00 01 00 00 00 00 00 00 00 00  `....$..........
        00 00 00 00 00 00 00 00 ff 02 00 00 00 00 00 00  ................
        00 00 00 00 00 00 00 16 3a 00 05 02 00 00 01 00  ........:.......
        8f 00 5a 3b 00 00 00 01 04 00 00 00 ff 02 00 00  ..Z;............
        00 00 00 00 00 00 00 01 ff d1 14 7e              ...........~
> ACL Data RX: Handle 11 flags 0x02 dlen 68                                           #57 [hci0] 21:54:01.265654
      Channel: 64 len 64 [PSM 15 mode 0] {chan 0}
      BNEP: Control (0x01|0)
         Filter MultAddr Set (0x05)
           Length: 0x003c
           ff:ff:ff:ff:ff:ff - ff:ff:ff:ff:ff:ff
           33:33:00:00:00:01 - 33:33:00:00:00:01
           01:00:5e:00:00:01 - 01:00:5e:00:00:01
           33:33:ff:d1:14:7e - 33:33:ff:d1:14:7e
           33:33:00:00:00:fb - 33:33:00:00:00:fb
```
The client seems to be created correctly.

I have been searching around and I cannot find any working solutions
being reported for GN or PANU using the tools that are currently
available.

There is this thread but it seems to have ended without conclusion
https://marc.info/?l=linux-bluetooth&m=149129850001348&w=2

I have added org.bluez.Network1 and org.bluez.NetworkServer1 to my
/etc/dbus-1/system.d/bluetooth.conf for both server and client.

Are there any other configuration files that need editing?

Any help or guidance gratefully received. Pointers to a tutorial or
the steps required would be good also as there appears to be some step
I'm missing.

Thanks,
Barry