2009-12-23 10:00:10

by bluezprofile kernel

[permalink] [raw]
Subject: service search for headset

Hi,
I am trying to get the service of the remote device. I have used
sdptool browse <remote mac>
to get the list of services supported by the remote device.

I have done between two laptops and I am able to see the services available.
When I do the same for my hands free device, I am not able to get the
service details of handsfree unit.
I have debugged this using sdptool application source.
sdptool application sends the attribute request to the hands free
device, in the reply I am not getting anything. (sdp_send_req and sdp_read_rsp)

sdptool record <remote mac> works fine.
sdptool browse --l2cap <remote mac> also works fine
Why --l2cap option required. Please any one explain me.

In my blueman application it shows the list of services when I pair.
Are they using record mechanism to display services?
Any one please help me in this regard.

I have used bluez 5.58
Nic Shen


2009-12-23 12:02:01

by Iain Hibbert

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Subject: Re: service search for headset

On Wed, 23 Dec 2009, bluezprofile kernel wrote:

> Do I need to use --l2cap option for finding service for such cases? Is
> this mandatory?

Sorry I don't really know, and it appears to be undocumented..

iain



2009-12-23 11:10:17

by bluezprofile kernel

[permalink] [raw]
Subject: Re: service search for headset

On Wed, Dec 23, 2009 at 3:49 PM, Iain Hibbert <[email protected]> wrote:
> On Wed, 23 Dec 2009, bluezprofile kernel wrote:
>
>> I have done between two laptops and I am able to see the services available.
>> When I do the same for my hands free device, I am not able to get the
>> service details of handsfree unit.
>> I have debugged this using sdptool application source.
>> sdptool application sends the attribute request to the hands free
>> device, in the reply I am not getting anything. (sdp_send_req and sdp_read_rsp)
>
> All that a "browse" does is start searching for the "Browse Group Root"
> UUID and if the handsfree device doesn't provide that UUID in any of the
> records then it will return no results when you search for it. ?Many
> devices don't provide "Browse Groups" at all (see SDP specification),
> probably your handsfree is like that.
>
> Searching for L2CAP will usually suffice to find all of the (relevant)
> service records in a Bluetooth environment, as most bluetooth protocols
> operate over L2CAP.
>
> iain
>
>
>
Thanks for your help. I will refer the SDP spec.
Do I need to use --l2cap option for finding service for such cases? Is
this mandatory?

2009-12-23 10:19:13

by Iain Hibbert

[permalink] [raw]
Subject: Re: service search for headset

On Wed, 23 Dec 2009, bluezprofile kernel wrote:

> I have done between two laptops and I am able to see the services available.
> When I do the same for my hands free device, I am not able to get the
> service details of handsfree unit.
> I have debugged this using sdptool application source.
> sdptool application sends the attribute request to the hands free
> device, in the reply I am not getting anything. (sdp_send_req and sdp_read_rsp)

All that a "browse" does is start searching for the "Browse Group Root"
UUID and if the handsfree device doesn't provide that UUID in any of the
records then it will return no results when you search for it. Many
devices don't provide "Browse Groups" at all (see SDP specification),
probably your handsfree is like that.

Searching for L2CAP will usually suffice to find all of the (relevant)
service records in a Bluetooth environment, as most bluetooth protocols
operate over L2CAP.

iain



2009-12-23 10:01:29

by bluezprofile kernel

[permalink] [raw]
Subject: Re: service search for headset

On Wed, Dec 23, 2009 at 3:30 PM, bluezprofile kernel
<[email protected]> wrote:
> Hi,
> I am trying to get the service of the remote device. I have used
> sdptool browse <remote mac>
> to get the list of services supported by the remote device.
>
> I have done between two laptops and I am able to see the services available.
> When I do the same for my hands free device, I am not able to get the
> service details of handsfree unit.
> I have debugged this using sdptool application source.
> sdptool application sends the attribute request to the hands free
> device, in the reply I am not getting anything. (sdp_send_req and sdp_read_rsp)
>
> sdptool record <remote mac> works fine.
> sdptool browse --l2cap <remote mac> also works fine
> Why --l2cap option required. Please any one explain me.
>
> In my blueman application it shows the list of services when I pair.
> Are they using record mechanism to display services?
> Any one please help me in this regard.
>
> I have used bluez 5.58
> Nic Shen
>

Sorry it is bluez 4.58