HFP gateway and new incoming connection

HFP gateway and new incoming connection

[Arnaud Mouiche]

Hi all.

I'm currently playing with the HFP unit role provided by bluez (ie. what 
is related to audio/gateway.c)
No problem concerning the connection to a HFP gateway (ie. GSM most of 
the time).

I have more concern with the reverse side, to accept incoming HFP 
connection, as, obviously I didn't get time to register a "Handsfree 
agent" for the particular new connecting device, at the proper time.

Today, I'm using bluez v4.95, but no real difference with the upstream 
for this case.
Also, I didn't plan to use oFono.... even if it is great piece of software.

I also saw a discussions concerning the initial design in the mailling 
list : http://marc.info/?l=linux-bluetooth&m=126390401614859&w=2

_My questions:_
1) does this design is today "set in stone" ?

2) It seems the only ways to register an agent at the proper time are:
- to trace creation of new devices, and try to register an agent at this 
time.
   But what if the device doesn't show HFP SDP record when connection 
for the first time, and activate it later ?
   Any race conditions ?
or
- collect the authorization request in the adapter user agent, when 
"audio_device_request_authorization" is called.
So it means that the user agent must forward request concerning the HFP 
uuid to the HFP service.

True ?

3) What do you think of the possibility to set a "adapter based" 
Handsfree agent, and use it when there is no "device based" handsfee 
argent matching ?
(the same way "device_request_authentication" (src/device.c) is looking 
for an agent registered to the device first, then, for an agent 
registered to the adapter)

Regards,
Arnaud Mouiche

Re: HFP gateway and new incoming connection

[Gustavo Padovan]

* Arnaud Mouiche <arnaud.mouiche@invoxia.com> [2011-08-22 18:48:57 +0200]:

> Hi all.
> 
> I'm currently playing with the HFP unit role provided by bluez (ie.
> what is related to audio/gateway.c)
> No problem concerning the connection to a HFP gateway (ie. GSM most
> of the time).
> 
> I have more concern with the reverse side, to accept incoming HFP
> connection, as, obviously I didn't get time to register a "Handsfree
> agent" for the particular new connecting device, at the proper time.
> 
> Today, I'm using bluez v4.95, but no real difference with the
> upstream for this case.
> Also, I didn't plan to use oFono.... even if it is great piece of software.
> 
> I also saw a discussions concerning the initial design in the
> mailling list :
> http://marc.info/?l=linux-bluetooth&m=126390401614859&w=2
> 
> _My questions:_
> 1) does this design is today "set in stone" ?

Not sure, we just changed it to add HFP version information.

> 
> 2) It seems the only ways to register an agent at the proper time are:
> - to trace creation of new devices, and try to register an agent at
> this time.
>   But what if the device doesn't show HFP SDP record when connection
> for the first time, and activate it later ?
>   Any race conditions ?

You should listen to DBus UUID property change for the device in the Agent
side. Check the bluetooth plugin inside oFono to learn how to implement that.

> or
> - collect the authorization request in the adapter user agent, when
> "audio_device_request_authorization" is called.
> So it means that the user agent must forward request concerning the
> HFP uuid to the HFP service.
> 
> True ?
> 
> 3) What do you think of the possibility to set a "adapter based"
> Handsfree agent, and use it when there is no "device based" handsfee
> argent matching ? 

I think Luiz also wants that. Luiz?

	Gustavo

Re: HFP gateway and new incoming connection

[Luiz Augusto von Dentz]

Hi,

On Mon, Aug 22, 2011 at 8:49 PM, Gustavo Padovan <padovan@profusion.mobi> wrote:
> * Arnaud Mouiche <arnaud.mouiche@invoxia.com> [2011-08-22 18:48:57 +0200]:
>
>> Hi all.
>>
>> I'm currently playing with the HFP unit role provided by bluez (ie.
>> what is related to audio/gateway.c)
>> No problem concerning the connection to a HFP gateway (ie. GSM most
>> of the time).
>>
>> I have more concern with the reverse side, to accept incoming HFP
>> connection, as, obviously I didn't get time to register a "Handsfree
>> agent" for the particular new connecting device, at the proper time.
>>
>> Today, I'm using bluez v4.95, but no real difference with the
>> upstream for this case.
>> Also, I didn't plan to use oFono.... even if it is great piece of software.
>>
>> I also saw a discussions concerning the initial design in the
>> mailling list :
>> http://marc.info/?l=linux-bluetooth&m=126390401614859&w=2
>>
>> _My questions:_
>> 1) does this design is today "set in stone" ?
>
> Not sure, we just changed it to add HFP version information.
>
>>
>> 2) It seems the only ways to register an agent at the proper time are:
>> - to trace creation of new devices, and try to register an agent at
>> this time.
>>   But what if the device doesn't show HFP SDP record when connection
>> for the first time, and activate it later ?
>>   Any race conditions ?
>
> You should listen to DBus UUID property change for the device in the Agent
> side. Check the bluetooth plugin inside oFono to learn how to implement that.
>
>> or
>> - collect the authorization request in the adapter user agent, when
>> "audio_device_request_authorization" is called.
>> So it means that the user agent must forward request concerning the
>> HFP uuid to the HFP service.
>>
>> True ?
>>
>> 3) What do you think of the possibility to set a "adapter based"
>> Handsfree agent, and use it when there is no "device based" handsfee
>> argent matching ?
>
> I think Luiz also wants that. Luiz?

Yep, we have some plans to move the Agent registration to adapter
path, so it gonna be per adapter. This is necessary to set the
features bit properly in the record and probably gonna support both
roles (with different agents). My initial idea was to use Media API,
but perhaps is confusing since HFP is not entirely about audio but
call control too (mostly) so perhaps we gonna have a different
interface for it e.g. org.bluez.Telephony, in addition to that we are
planning to pass the endpoint bus and path together in the
NewConnection so the telephony agent (oFono) can communicate directly
to endpoint in use (PulseAudio).

Those are my plans, but none of this is set in stone and Im pretty
open for ideas

-- 
Luiz Augusto von Dentz

Re: HFP gateway and new incoming connection

[Arnaud Mouiche]

Hi,

On 08/22/2011 09:58 PM, Luiz Augusto von Dentz wrote:
> [...]
> Yep, we have some plans to move the Agent registration to adapter
> path, so it gonna be per adapter. This is necessary to set the
> features bit properly in the record and probably gonna support both
> roles (with different agents). My initial idea was to use Media API,
> but perhaps is confusing since HFP is not entirely about audio but
> call control too (mostly) so perhaps we gonna have a different
> interface for it e.g. org.bluez.Telephony, in addition to that we are
> planning to pass the endpoint bus and path together in the
> NewConnection so the telephony agent (oFono) can communicate directly
> to endpoint in use (PulseAudio).
>
> Those are my plans, but none of this is set in stone and Im pretty
> open for ideas
>

what about using the org.bluez.Adapter / RegisterAgent API, and add:
- the possibility to setup multiple agents (maintain a list of agents)
- use the "capability" field as a filter definition to find the good 
agent for the particular request
ex:
     audio/gateway.c::agent_sendfd() will look for a agent in the list, 
with a "HFP" capability to send the "NewConnection" request

Arnaud

Re: HFP gateway and new incoming connection

[Luiz Augusto von Dentz]

Hi Arnaud,

On Tue, Aug 23, 2011 at 12:08 PM, Arnaud Mouiche
<arnaud.mouiche@invoxia.com> wrote:
> Hi,
>
> On 08/22/2011 09:58 PM, Luiz Augusto von Dentz wrote:
>>
>> [...]
>> Yep, we have some plans to move the Agent registration to adapter
>> path, so it gonna be per adapter. This is necessary to set the
>> features bit properly in the record and probably gonna support both
>> roles (with different agents). My initial idea was to use Media API,
>> but perhaps is confusing since HFP is not entirely about audio but
>> call control too (mostly) so perhaps we gonna have a different
>> interface for it e.g. org.bluez.Telephony, in addition to that we are
>> planning to pass the endpoint bus and path together in the
>> NewConnection so the telephony agent (oFono) can communicate directly
>> to endpoint in use (PulseAudio).
>>
>> Those are my plans, but none of this is set in stone and Im pretty
>> open for ideas
>>
>
> what about using the org.bluez.Adapter / RegisterAgent API, and add:
> - the possibility to setup multiple agents (maintain a list of agents)
> - use the "capability" field as a filter definition to find the good agent
> for the particular request
> ex:
>    audio/gateway.c::agent_sendfd() will look for a agent in the list, with a
> "HFP" capability to send the "NewConnection" request

I guess it would be confusing since with the same method we would have
different types of agents which implements different interfaces, there
is also the problem that by using Adapter interface it would have to
be implemented in the core daemon but my intention is to maintain this
inside the audio plugin to hook with Media API.

-- 
Luiz Augusto von Dentz

Re: HFP gateway and new incoming connection

[Arnaud Mouiche]

On 08/23/2011 01:14 PM, Luiz Augusto von Dentz wrote:
> Hi Arnaud,
>
> On Tue, Aug 23, 2011 at 12:08 PM, Arnaud Mouiche
> <arnaud.mouiche@invoxia.com>  wrote:
>> Hi,
>>
>> On 08/22/2011 09:58 PM, Luiz Augusto von Dentz wrote:
>>> [...]
>>> Yep, we have some plans to move the Agent registration to adapter
>>> path, so it gonna be per adapter. This is necessary to set the
>>> features bit properly in the record and probably gonna support both
>>> roles (with different agents). My initial idea was to use Media API,
>>> but perhaps is confusing since HFP is not entirely about audio but
>>> call control too (mostly) so perhaps we gonna have a different
>>> interface for it e.g. org.bluez.Telephony, in addition to that we are
>>> planning to pass the endpoint bus and path together in the
>>> NewConnection so the telephony agent (oFono) can communicate directly
>>> to endpoint in use (PulseAudio).
>>>
>>> Those are my plans, but none of this is set in stone and Im pretty
>>> open for ideas
>>>
>> what about using the org.bluez.Adapter / RegisterAgent API, and add:
>> - the possibility to setup multiple agents (maintain a list of agents)
>> - use the "capability" field as a filter definition to find the good agent
>> for the particular request
>> ex:
>>     audio/gateway.c::agent_sendfd() will look for a agent in the list, with a
>> "HFP" capability to send the "NewConnection" request
> I guess it would be confusing since with the same method we would have
> different types of agents which implements different interfaces, there
> is also the problem that by using Adapter interface it would have to
> be implemented in the core daemon but my intention is to maintain this
> inside the audio plugin to hook with Media API.
>
You are right. I didn't see how the core was compartmentalized from plugins.
I need took more closely to the Media API...

arnaud

Re: HFP gateway and new incoming connection

[Luiz Augusto von Dentz]

Hi,

On Tue, Aug 23, 2011 at 2:53 PM, Arnaud Mouiche
<arnaud.mouiche@invoxia.com> wrote:
> On 08/23/2011 01:14 PM, Luiz Augusto von Dentz wrote:
>>
>> Hi Arnaud,
>>
>> On Tue, Aug 23, 2011 at 12:08 PM, Arnaud Mouiche
>> <arnaud.mouiche@invoxia.com>  wrote:
>>>
>>> Hi,
>>>
>>> On 08/22/2011 09:58 PM, Luiz Augusto von Dentz wrote:
>>>>
>>>> [...]
>>>> Yep, we have some plans to move the Agent registration to adapter
>>>> path, so it gonna be per adapter. This is necessary to set the
>>>> features bit properly in the record and probably gonna support both
>>>> roles (with different agents). My initial idea was to use Media API,
>>>> but perhaps is confusing since HFP is not entirely about audio but
>>>> call control too (mostly) so perhaps we gonna have a different
>>>> interface for it e.g. org.bluez.Telephony, in addition to that we are
>>>> planning to pass the endpoint bus and path together in the
>>>> NewConnection so the telephony agent (oFono) can communicate directly
>>>> to endpoint in use (PulseAudio).
>>>>
>>>> Those are my plans, but none of this is set in stone and Im pretty
>>>> open for ideas
>>>>
>>> what about using the org.bluez.Adapter / RegisterAgent API, and add:
>>> - the possibility to setup multiple agents (maintain a list of agents)
>>> - use the "capability" field as a filter definition to find the good
>>> agent
>>> for the particular request
>>> ex:
>>>    audio/gateway.c::agent_sendfd() will look for a agent in the list,
>>> with a
>>> "HFP" capability to send the "NewConnection" request
>>
>> I guess it would be confusing since with the same method we would have
>> different types of agents which implements different interfaces, there
>> is also the problem that by using Adapter interface it would have to
>> be implemented in the core daemon but my intention is to maintain this
>> inside the audio plugin to hook with Media API.
>>
> You are right. I didn't see how the core was compartmentalized from plugins.
> I need took more closely to the Media API...
>

How about the following:

Telephony hierarchy [experiemental]
===================

Service		org.bluez
Interface	org.bluez.Telephony
Object path	[variable prefix]/{hci0,hci1,...}

Methods		void RegisterAgent(object path, dict properties)

			Register a TelephonyAgent to sender, the sender can
			register as many agents as it likes.

			Note: If the sender disconnects its agents are
			automatically unregistered.

			possible properties:

				string UUID:

					UUID of the profile which the agent is
					for.

				uint16 Version:

					Version of the profile which the agent
					implements.

				byte Features:

					Agent supported features as defined in
					profile spec e.g. HFP.

			Possible Errors: org.bluez.Error.InvalidArguments


		void UnregisterAgent(object path)

			Unregister sender agent.

TelephonyAgent hierarchy
========================

Service		unique name
Interface	org.bluez.TelephonyAgent
Object path	freely definable

ethods		void NewConnection(filedescriptor fd, dict properties)

			This method gets called whenever a new connection
			has been established. This method assumes that DBus
			daemon with file descriptor passing capability is
			being used.

			The agent should only return successfully once the
			establishment of the service level connection (SLC)
			has been completed.  In the case of Handsfree this
			means that BRSF exchange has been performed and
			necessary initialization has been done.

			If Endpoint is set the agent is responsible to
			create an object implementing org.bluez.MediaTransport
			and notify the Endpoint using org.bluez.MediaEndpoint.

			possible properties:

				strict Device:

					BlueZ remote device object.

				string UUID:

					Profile UUID of the connection.

				uint16 Version:

					Remote profile version.

				byte Features:

					Remote profile features.

				string Endpoint:

					Optional. Endpoint bus id.

				string EndpointPath:

					Optional. Endpoint object path.

			Possible Errors: org.bluez.Error.InvalidArguments
					 org.bluez.Error.Failed

		void Release()

			This method gets called whenever the service daemon
			unregisters the agent or whenever the Adapter where
			the TelephonyAgent registers itself is removed.


-- 
Luiz Augusto von Dentz

Re: HFP gateway and new incoming connection

[Arnaud Mouiche]

Hi,

This looks fine to me.
But I'm not the one with sufficiently good experience in this part of 
bluez to be a good advise, and see long-term implications
regards,
arnaud


On 08/24/2011 01:03 PM, Luiz Augusto von Dentz wrote:
> Hi,
>
> On Tue, Aug 23, 2011 at 2:53 PM, Arnaud Mouiche
> <arnaud.mouiche@invoxia.com>  wrote:
>> On 08/23/2011 01:14 PM, Luiz Augusto von Dentz wrote:
>>> Hi Arnaud,
>>>
>>> On Tue, Aug 23, 2011 at 12:08 PM, Arnaud Mouiche
>>> <arnaud.mouiche@invoxia.com>    wrote:
>>>> Hi,
>>>>
>>>> On 08/22/2011 09:58 PM, Luiz Augusto von Dentz wrote:
>>>>> [...]
>>>>> Yep, we have some plans to move the Agent registration to adapter
>>>>> path, so it gonna be per adapter. This is necessary to set the
>>>>> features bit properly in the record and probably gonna support both
>>>>> roles (with different agents). My initial idea was to use Media API,
>>>>> but perhaps is confusing since HFP is not entirely about audio but
>>>>> call control too (mostly) so perhaps we gonna have a different
>>>>> interface for it e.g. org.bluez.Telephony, in addition to that we are
>>>>> planning to pass the endpoint bus and path together in the
>>>>> NewConnection so the telephony agent (oFono) can communicate directly
>>>>> to endpoint in use (PulseAudio).
>>>>>
>>>>> Those are my plans, but none of this is set in stone and Im pretty
>>>>> open for ideas
>>>>>
>>>> what about using the org.bluez.Adapter / RegisterAgent API, and add:
>>>> - the possibility to setup multiple agents (maintain a list of agents)
>>>> - use the "capability" field as a filter definition to find the good
>>>> agent
>>>> for the particular request
>>>> ex:
>>>>     audio/gateway.c::agent_sendfd() will look for a agent in the list,
>>>> with a
>>>> "HFP" capability to send the "NewConnection" request
>>> I guess it would be confusing since with the same method we would have
>>> different types of agents which implements different interfaces, there
>>> is also the problem that by using Adapter interface it would have to
>>> be implemented in the core daemon but my intention is to maintain this
>>> inside the audio plugin to hook with Media API.
>>>
>> You are right. I didn't see how the core was compartmentalized from plugins.
>> I need took more closely to the Media API...
>>
> How about the following:
>
> Telephony hierarchy [experiemental]
> ===================
>
> Service		org.bluez
> Interface	org.bluez.Telephony
> Object path	[variable prefix]/{hci0,hci1,...}
>
> Methods		void RegisterAgent(object path, dict properties)
>
> 			Register a TelephonyAgent to sender, the sender can
> 			register as many agents as it likes.
>
> 			Note: If the sender disconnects its agents are
> 			automatically unregistered.
>
> 			possible properties:
>
> 				string UUID:
>
> 					UUID of the profile which the agent is
> 					for.
>
> 				uint16 Version:
>
> 					Version of the profile which the agent
> 					implements.
>
> 				byte Features:
>
> 					Agent supported features as defined in
> 					profile spec e.g. HFP.
>
> 			Possible Errors: org.bluez.Error.InvalidArguments
>
>
> 		void UnregisterAgent(object path)
>
> 			Unregister sender agent.
>
> TelephonyAgent hierarchy
> ========================
>
> Service		unique name
> Interface	org.bluez.TelephonyAgent
> Object path	freely definable
>
> ethods		void NewConnection(filedescriptor fd, dict properties)
>
> 			This method gets called whenever a new connection
> 			has been established. This method assumes that DBus
> 			daemon with file descriptor passing capability is
> 			being used.
>
> 			The agent should only return successfully once the
> 			establishment of the service level connection (SLC)
> 			has been completed.  In the case of Handsfree this
> 			means that BRSF exchange has been performed and
> 			necessary initialization has been done.
>
> 			If Endpoint is set the agent is responsible to
> 			create an object implementing org.bluez.MediaTransport
> 			and notify the Endpoint using org.bluez.MediaEndpoint.
>
> 			possible properties:
>
> 				strict Device:
>
> 					BlueZ remote device object.
>
> 				string UUID:
>
> 					Profile UUID of the connection.
>
> 				uint16 Version:
>
> 					Remote profile version.
>
> 				byte Features:
>
> 					Remote profile features.
>
> 				string Endpoint:
>
> 					Optional. Endpoint bus id.
>
> 				string EndpointPath:
>
> 					Optional. Endpoint object path.
>
> 			Possible Errors: org.bluez.Error.InvalidArguments
> 					 org.bluez.Error.Failed
>
> 		void Release()
>
> 			This method gets called whenever the service daemon
> 			unregisters the agent or whenever the Adapter where
> 			the TelephonyAgent registers itself is removed.
>
>

Re: HFP gateway and new incoming connection

[Frederic Danis]

Hello,

Le 24/08/2011 13:03, Luiz Augusto von Dentz a écrit :
> Hi,
>
> On Tue, Aug 23, 2011 at 2:53 PM, Arnaud Mouiche
> <arnaud.mouiche@invoxia.com>  wrote:
>> On 08/23/2011 01:14 PM, Luiz Augusto von Dentz wrote:
>>>
>>> Hi Arnaud,
>>>
>>> On Tue, Aug 23, 2011 at 12:08 PM, Arnaud Mouiche
>>> <arnaud.mouiche@invoxia.com>    wrote:
>>>>
>>>> Hi,
>>>>
>>>> On 08/22/2011 09:58 PM, Luiz Augusto von Dentz wrote:
>>>>>
>>>>> [...]
>>>>> Yep, we have some plans to move the Agent registration to adapter
>>>>> path, so it gonna be per adapter. This is necessary to set the
>>>>> features bit properly in the record and probably gonna support both
>>>>> roles (with different agents). My initial idea was to use Media API,
>>>>> but perhaps is confusing since HFP is not entirely about audio but
>>>>> call control too (mostly) so perhaps we gonna have a different
>>>>> interface for it e.g. org.bluez.Telephony, in addition to that we are
>>>>> planning to pass the endpoint bus and path together in the
>>>>> NewConnection so the telephony agent (oFono) can communicate directly
>>>>> to endpoint in use (PulseAudio).
>>>>>
>>>>> Those are my plans, but none of this is set in stone and Im pretty
>>>>> open for ideas
>>>>>
>>>> what about using the org.bluez.Adapter / RegisterAgent API, and add:
>>>> - the possibility to setup multiple agents (maintain a list of agents)
>>>> - use the "capability" field as a filter definition to find the good
>>>> agent
>>>> for the particular request
>>>> ex:
>>>>     audio/gateway.c::agent_sendfd() will look for a agent in the list,
>>>> with a
>>>> "HFP" capability to send the "NewConnection" request
>>>
>>> I guess it would be confusing since with the same method we would have
>>> different types of agents which implements different interfaces, there
>>> is also the problem that by using Adapter interface it would have to
>>> be implemented in the core daemon but my intention is to maintain this
>>> inside the audio plugin to hook with Media API.
>>>
>> You are right. I didn't see how the core was compartmentalized from plugins.
>> I need took more closely to the Media API...
>>
>
> How about the following:
>
> Telephony hierarchy [experiemental]
> ===================
>
> Service		org.bluez
> Interface	org.bluez.Telephony
> Object path	[variable prefix]/{hci0,hci1,...}
>
> Methods		void RegisterAgent(object path, dict properties)
>
> 			Register a TelephonyAgent to sender, the sender can
> 			register as many agents as it likes.
>
> 			Note: If the sender disconnects its agents are
> 			automatically unregistered.
>
> 			possible properties:
>
> 				string UUID:
>
> 					UUID of the profile which the agent is
> 					for.
>
> 				uint16 Version:
>
> 					Version of the profile which the agent
> 					implements.
>
> 				byte Features:
>
> 					Agent supported features as defined in
> 					profile spec e.g. HFP.
>
> 			Possible Errors: org.bluez.Error.InvalidArguments
>
>
> 		void UnregisterAgent(object path)
>
> 			Unregister sender agent.
>
> TelephonyAgent hierarchy
> ========================
>
> Service		unique name
> Interface	org.bluez.TelephonyAgent
> Object path	freely definable
>
> ethods		void NewConnection(filedescriptor fd, dict properties)
>
> 			This method gets called whenever a new connection
> 			has been established. This method assumes that DBus
> 			daemon with file descriptor passing capability is
> 			being used.
>
> 			The agent should only return successfully once the
> 			establishment of the service level connection (SLC)
> 			has been completed.  In the case of Handsfree this
> 			means that BRSF exchange has been performed and
> 			necessary initialization has been done.
>
> 			If Endpoint is set the agent is responsible to
> 			create an object implementing org.bluez.MediaTransport
> 			and notify the Endpoint using org.bluez.MediaEndpoint.
>
> 			possible properties:
>
> 				strict Device:
>
> 					BlueZ remote device object.
>
> 				string UUID:
>
> 					Profile UUID of the connection.
>
> 				uint16 Version:
>
> 					Remote profile version.
>
> 				byte Features:
>
> 					Remote profile features.
>
> 				string Endpoint:
>
> 					Optional. Endpoint bus id.
>
> 				string EndpointPath:
>
> 					Optional. Endpoint object path.
>
> 			Possible Errors: org.bluez.Error.InvalidArguments
> 					 org.bluez.Error.Failed
>
> 		void Release()
>
> 			This method gets called whenever the service daemon
> 			unregisters the agent or whenever the Adapter where
> 			the TelephonyAgent registers itself is removed.
>
>

This interface should be used with org.bluez.Media API, daemon 
registering with org.bluez.Telephony will take care of control channel 
while org.bluez.Media will be used to manage audio part, did I 
understand correctly ?

I understand how connection will be managed for server part (incoming 
connections), but what will be used for client part (outgoing connections) ?

It may be possible to use a per device interface similar to 
org.bluez.HandsfreeGateway with only connect/disconnect methods (with 
different interfaces for each HFP roles).

Regards

Fred

-- 
Frederic Danis                            Open Source Technology Centre
frederic.danis@intel.com                              Intel Corporation

Re: HFP gateway and new incoming connection

[Frederic Danis]

Hello,

Le 24/08/2011 13:03, Luiz Augusto von Dentz a écrit :
> Hi,
>
> On Tue, Aug 23, 2011 at 2:53 PM, Arnaud Mouiche
> <arnaud.mouiche@invoxia.com>  wrote:
>> On 08/23/2011 01:14 PM, Luiz Augusto von Dentz wrote:
>>>
>>> Hi Arnaud,
>>>
>>> On Tue, Aug 23, 2011 at 12:08 PM, Arnaud Mouiche
>>> <arnaud.mouiche@invoxia.com>    wrote:
>>>>
>>>> Hi,
>>>>
>>>> On 08/22/2011 09:58 PM, Luiz Augusto von Dentz wrote:
>>>>>
>>>>> [...]
>>>>> Yep, we have some plans to move the Agent registration to adapter
>>>>> path, so it gonna be per adapter. This is necessary to set the
>>>>> features bit properly in the record and probably gonna support both
>>>>> roles (with different agents). My initial idea was to use Media API,
>>>>> but perhaps is confusing since HFP is not entirely about audio but
>>>>> call control too (mostly) so perhaps we gonna have a different
>>>>> interface for it e.g. org.bluez.Telephony, in addition to that we are
>>>>> planning to pass the endpoint bus and path together in the
>>>>> NewConnection so the telephony agent (oFono) can communicate directly
>>>>> to endpoint in use (PulseAudio).
>>>>>
>>>>> Those are my plans, but none of this is set in stone and Im pretty
>>>>> open for ideas
>>>>>
>>>> what about using the org.bluez.Adapter / RegisterAgent API, and add:
>>>> - the possibility to setup multiple agents (maintain a list of agents)
>>>> - use the "capability" field as a filter definition to find the good
>>>> agent
>>>> for the particular request
>>>> ex:
>>>>     audio/gateway.c::agent_sendfd() will look for a agent in the list,
>>>> with a
>>>> "HFP" capability to send the "NewConnection" request
>>>
>>> I guess it would be confusing since with the same method we would have
>>> different types of agents which implements different interfaces, there
>>> is also the problem that by using Adapter interface it would have to
>>> be implemented in the core daemon but my intention is to maintain this
>>> inside the audio plugin to hook with Media API.
>>>
>> You are right. I didn't see how the core was compartmentalized from plugins.
>> I need took more closely to the Media API...
>>
>
> How about the following:
>
> Telephony hierarchy [experiemental]
> ===================
>
> Service		org.bluez
> Interface	org.bluez.Telephony
> Object path	[variable prefix]/{hci0,hci1,...}
>
> Methods		void RegisterAgent(object path, dict properties)
>
> 			Register a TelephonyAgent to sender, the sender can
> 			register as many agents as it likes.
>
> 			Note: If the sender disconnects its agents are
> 			automatically unregistered.
>
> 			possible properties:
>
> 				string UUID:
>
> 					UUID of the profile which the agent is
> 					for.
>
> 				uint16 Version:
>
> 					Version of the profile which the agent
> 					implements.
>
> 				byte Features:
>
> 					Agent supported features as defined in
> 					profile spec e.g. HFP.
>
> 			Possible Errors: org.bluez.Error.InvalidArguments
>
>
> 		void UnregisterAgent(object path)
>
> 			Unregister sender agent.
>
> TelephonyAgent hierarchy
> ========================
>
> Service		unique name
> Interface	org.bluez.TelephonyAgent
> Object path	freely definable
>
> ethods		void NewConnection(filedescriptor fd, dict properties)
>
> 			This method gets called whenever a new connection
> 			has been established. This method assumes that DBus
> 			daemon with file descriptor passing capability is
> 			being used.
>
> 			The agent should only return successfully once the
> 			establishment of the service level connection (SLC)
> 			has been completed.  In the case of Handsfree this
> 			means that BRSF exchange has been performed and
> 			necessary initialization has been done.
>
> 			If Endpoint is set the agent is responsible to
> 			create an object implementing org.bluez.MediaTransport
> 			and notify the Endpoint using org.bluez.MediaEndpoint.
>
> 			possible properties:
>
> 				strict Device:
>
> 					BlueZ remote device object.
>
> 				string UUID:
>
> 					Profile UUID of the connection.
>
> 				uint16 Version:
>
> 					Remote profile version.
>
> 				byte Features:
>
> 					Remote profile features.
>
> 				string Endpoint:
>
> 					Optional. Endpoint bus id.
>
> 				string EndpointPath:
>
> 					Optional. Endpoint object path.
>
> 			Possible Errors: org.bluez.Error.InvalidArguments
> 					 org.bluez.Error.Failed
>
> 		void Release()
>
> 			This method gets called whenever the service daemon
> 			unregisters the agent or whenever the Adapter where
> 			the TelephonyAgent registers itself is removed.
>
>

This interface should be used with org.bluez.Media API, daemon 
registering with org.bluez.Telephony will take care of control channel 
while org.bluez.Media will be used to manage audio part, did I 
understand correctly ?

I understand how connection will be managed for server part (incoming 
connections), but what will be used for client part (outgoing connections) ?

It may be possible to use a per device interface similar to 
org.bluez.HandsfreeGateway with only connect/disconnect methods (with 
different interfaces for each HFP roles).

Regards

Fred

-- 
Frederic Danis                            Open Source Technology Centre
frederic.danis@intel.com                              Intel Corporation