Gatt server with random address does not work (everything is ok with public address)

Gatt server with random address does not work (everything is ok with public address)

[Pavel Machek]

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Hi!

I adapted example-gatt-server for a project... and it works ok
(thanks), as long as public address is used. I could not configure
random address in main.conf, so I'm doing it with btmgmt:

#!/bin/bash
(
    echo power off
    sleep .1
    echo le on
    sleep .1
    echo bredr off
    sleep .1
    echo static-addr c2:34:56:78:90:ab
    #echo public-addr 00:1A:7D:DA:71:11
    #echo static-addr c2:34:56:78:90:ab
    sleep .1
    echo connectable on
    sleep .1
    echo pairable on
    sleep .1
#    echo discov on
    sleep .1
#    echo advertising on
    sleep .1
    sleep .1
    echo power on
) | sudo ../bluez/tools/btmgmt
sleep 2

With random address, it does not work: lescan from other machine
detects right address, and I can connect, but that's it, services
can't be listed.

I'm using 4.19 kernel on one side and current -next on the other side,
with bluez e4cf43fc62b4e4dbabc72d4e44e095d7a9087992, Fri Sep 7
16:25:44 2018.

And it seems I'm not the only one having this problem:
https://stackoverflow.com/questions/50707914/setup-bluez-gatt-server-with-random-address

Any ideas how to debug that? Does configuration with random address
work for you? Is there chance update to latest versions helps?

Thanks,
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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Re: Gatt server with random address does not work (everything is ok with public address)

[Luiz Augusto von Dentz]

Hi Pavel,

On Tue, Apr 16, 2019 at 10:35 PM Pavel Machek <pavel@ucw.cz> wrote:
>
> Hi!
>
> I adapted example-gatt-server for a project... and it works ok
> (thanks), as long as public address is used. I could not configure
> random address in main.conf, so I'm doing it with btmgmt:

Have you tried setting Privacy = device?
https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/src/main.conf#n71

> #!/bin/bash
> (
>     echo power off
>     sleep .1
>     echo le on
>     sleep .1
>     echo bredr off
>     sleep .1
>     echo static-addr c2:34:56:78:90:ab
>     #echo public-addr 00:1A:7D:DA:71:11
>     #echo static-addr c2:34:56:78:90:ab
>     sleep .1
>     echo connectable on
>     sleep .1
>     echo pairable on
>     sleep .1
> #    echo discov on
>     sleep .1
> #    echo advertising on
>     sleep .1
>     sleep .1
>     echo power on
> ) | sudo ../bluez/tools/btmgmt
> sleep 2
>
> With random address, it does not work: lescan from other machine
> detects right address, and I can connect, but that's it, services
> can't be listed.

bluetoothd don't really know that you have set a static address like
that, anyway I don't know what exactly is not working so it very hard
to give any instruction with such vague description of the problem.

> I'm using 4.19 kernel on one side and current -next on the other side,
> with bluez e4cf43fc62b4e4dbabc72d4e44e095d7a9087992, Fri Sep 7
> 16:25:44 2018.
>
> And it seems I'm not the only one having this problem:
> https://stackoverflow.com/questions/50707914/setup-bluez-gatt-server-with-random-address
>
> Any ideas how to debug that? Does configuration with random address
> work for you? Is there chance update to latest versions helps?

Look at privacy, if that doesn't work then collect the journal logs
and btmon traces, etc.


-- 
Luiz Augusto von Dentz

Re: Gatt server with random address does not work (everything is ok with public address)

[Pavel Machek]

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Hi!

> > I adapted example-gatt-server for a project... and it works ok
> > (thanks), as long as public address is used. I could not configure
> > random address in main.conf, so I'm doing it with btmgmt:
> 
> Have you tried setting Privacy = device?
> https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/src/main.conf#n71

I tried playing with privacy, but could not get it to work. But that
was some time ago, and I could have messed it up.

> > #!/bin/bash
> > (
...
> >     echo static-addr c2:34:56:78:90:ab
...
> >     sleep .1
> >     echo power on
> > ) | sudo ../bluez/tools/btmgmt
> > sleep 2
> >
> > With random address, it does not work: lescan from other machine
> > detects right address, and I can connect, but that's it, services
> > can't be listed.
> 
> bluetoothd don't really know that you have set a static address like
> that, anyway I don't know what exactly is not working so it very hard
> to give any instruction with such vague description of the problem.

Ok, if bluetoothd does not know I've done this, that would kind of
explain the problem.

I'm trying to run gatt-server, so I'll need to get static address to
work somehow. What is the correct way to set static address, so that
bluetoothd has chance to know about it? Do I need to patch sources for
that?

> > I'm using 4.19 kernel on one side and current -next on the other side,
> > with bluez e4cf43fc62b4e4dbabc72d4e44e095d7a9087992, Fri Sep 7
> > 16:25:44 2018.
> >
> > And it seems I'm not the only one having this problem:
> > https://stackoverflow.com/questions/50707914/setup-bluez-gatt-server-with-random-address
> >
> > Any ideas how to debug that? Does configuration with random address
> > work for you? Is there chance update to latest versions helps?
> 
> Look at privacy, if that doesn't work then collect the journal logs
> and btmon traces, etc.

Privacy does not do exactly what I need, but I'll try. 

Thanks a lot for help,
									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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Re: Gatt server with random address does not work (everything is ok with public address)

[Pavel Machek]

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Hi!

> > > I adapted example-gatt-server for a project... and it works ok
> > > (thanks), as long as public address is used. I could not configure
> > > random address in main.conf, so I'm doing it with btmgmt:
> > 
> > Have you tried setting Privacy = device?
> > https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/src/main.conf#n71
> 
> I tried playing with privacy, but could not get it to work. But that
> was some time ago, and I could have messed it up.

With privacy = device, bluetoothd does not have enough keys, so it
does _not_ turn it on.

Bluetooth daemon 5.50
...
No IRK stored
Failed to open crypto
Failed to set privacy: rejected.

I guess there are instructions somewhere how to set it up, but I'd
really like static random address, not this.

Best regards,
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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