This api is a clean up of the previous one the changes.
We've added a new object that uses device path to get the sessions
allocated on this device (as somebody recommended in other thread,
I think Luiz, Elvis or both, but I can't find the exact email). The discovery
of new remote session should be done using device drivers, which is
compliant with the BlueZ style.
Discussions still in progress:
- Fd-passing issue: As Elvis, Santiago and I discussed yesterday on
IRC we think that the best propose is as follows (please Elvis correct
me if I misunderstood something yesterday):
Reconnections should be implicit and the data channel should
be perceived by the application layer as connected all the time.
When the application tries to write in a closed data channel, HDP
will perform the data channel reconnection and if it fails, then the channel
will be present as closed.
The implementation for this this behaviour will use pipes. Each data
channel will use 2 pipes to do fd-passing to the application. The upper
layer will write in this pipes and HDP will redirect it through the l2cap socket,
in this operation, HDP can reconnect if th l2cap socket is closed.
- Sessions issues: We still think that session are necessary because they
are mentioned in the standard and in the whitepaper and we think that
bluez should follow the standards in order to pass PTS for allow Bluetooth SIG
certifications. Any comment in this respect are welcome to improve the API
usability and conformity with Bluez APIs.
- Paths issues: It will be great to find names and paths that are good for
everybody, comments and suggestion on this respect are also welcome.
I hope we can fix this API asap. All comments or ideas are welcome.
Regards.
--------------------------------------------------
BlueZ D-Bus HDP API description
***********************************
Santiago Carot-Nemesio <sancane@xxxxxxxxx>
José Antonio Santos-Cadenas <santoscadenas@xxxxxxxxx>
Elvis Pfützenreuter <epx@xxxxxxxxxxx>
Health Device Profile hierarchy
===============================
Service org.bluez
Interface org.bluez.Hdp
Object path [variable prefix]/{hci0,hci1,...}
Methods object CreateSession(object path, dict config)
Returns the object path for the new HDP session.
The path parameter is the path of the remote object
with the callbacks to notify events (see
org.bluez.HdpAgent at the end of this document)
This petition starts an mcap session and also register
in the SDP is needed
Dict is defined as bellow:
{ "data_spec" : The data_spec is the data exchange
specification (see section 5.2.10 of
the specification document)
possible values:
0x00 = reserved,
0x01 [IEEE 11073-20601],
0x02..0xff reserved,
(optional)
"end_points" : [{ (optional)
"mdepid" : uint8, (optional)
"role" : ("source" or "sink"), (mandatory)
"specs" :[{ (mandatory)
"data_type" : uint16, (mandatory)
"description" : string, (optional)
}]
}]
}
if "data_spec" is not set, no SDP record will be
registered, so all the other data in the dictionary
will be ignored
Session will be closed by the call or implicitly when
the programs leaves the bus.
Possible errors: org.bluez.Error.InvalidArguments
void CloseSession(object path)
Closes the HDP session identified by the object path.
Also session will be closed if the process that started
it is removed from the D-Bus.
Possible errors: org.bluez.Error.InvalidArguments
org.bluez.Error.NotFound
--------------------------------------------------------------------------------
Service org.bluez
Interface org.bluez.Hdp
Object path [variable prefix]/{hci0,hci1,...}/dev_XX_XX_XX_XX_XX_XX
Methods array GetSessions()
Gets the information of the remote sessions present
in this device and published on its SDP record. The
returned data follows this format.
[{"session_id": "a session identification as string",
"data_spec" : session data spec,
"end_points":
["mdepid": uint8,
"role" : "source" or "sink" ,
"specs" : [{
"dtype" : uint16,
"description" : string, (optional)
}]
]
}]
--------------------------------------------------------------------------------
Service org.bluez
Interface org.bluez.HdpSession
Object path [variable prefix]/{hci0,hci1,...}/{hdp0,hdp1,...}
object Connect(remote_session_id)
Connects with the remote session and returns its object
path.
Possible errors: org.bluez.Error.InvalidArguments
org.bluez.Error.HdpError
void Disconnect(object device, boolean delete)
Disconnect from the remote device. If delete is true, any
status will also be deleted. Otherwise, the status will
be kept for allowing future reconnections.
Possible errors: org.bluez.Error.InvalidArguments
org.bluez.Error.NotFound
org.bluez.Error.HdpError
--------------------------------------------------------------------------------
Service org.bluez
Interface org.bluez.HdpRemoteSession
Object path [variable prefix]/{hci0,hci1,...}/{hdp0,hdp1,...}/rem_session_id
boolean Echo(array{byte})
Sends an echo petition to the remote session. Return True
if response matches with the buffer sent. If some error
is detected False value is returned and the associated
MCL is closed.
uint16 OpenDataChannel(byte mdepid, byte config)
Creates a new data channel with the indicated config
to the remote MCAP Data End Point (MDEP).
The configuration should indicate the channel quality of
service.
Returns the data channel id.
Possible errors: org.bluez.Error.InvalidArguments
org.bluez.Error.HdpError
array GetDcFd(uint16 mdlid)
Gets a file descriptor where data can be read or
written for receive or sent by the data channel.
Returns an array of file descriptors one for write
and other for read.
Possible errors: org.bluez.Error.InvalidArguments
org.bluez.Error.NotFound
org.bluez.Error.HdpError
void DeleteDataChannel(uint16 mdlid)
Deletes a data channel so it will not be available for
use.
Possible errors: org.bluez.Error.InvalidArguments
org.bluez.Error.NotFound
org.bluez.Error.HdpError
void DeleteAllDataChannels()
Deletes all data channels so it will not be available
for use. Typically this function is called when the
connection with the remote device will be closed
permanently
Possible errors: org.bluez.Error.HdpError
dict GetDataChannelStatus()
Return a dictionary with all the data channels that
can be used to send data right now. The dictionary
is formed like follows:
{
"reliable": [id1, ..., idz],
"best_effort" : [idx, ..., idy]
}
The fist reliable data channel will always be the first
data channel in reliable array.
HDPAgent hierarchy
==================
(this object is implemented by the HDP client an receives notifications)
Service unique name
Interface org.bluez.HdpAgent
Object path freely definable
void DeviceConnected(object path)
This method is called whenever a new device connection
has been established over the control channel of the
current HDP session. The object path contains the object
path of the remote device.
void DeviceDisconnected(object path)
This method is called when a remote device is
disconnected definitively. Any future reconnections
will fail. Also all data channels associated to this
device will be closed.
void CreatedDataChannel(object path, uint16 mdlid)
This method is called when a new data channel is created
The path contains the object path of the device whith
the new connection is created and the mdlid the data
channel identificator.
void DeletedDataChannel(object path, uint16 mdlid)
This method is called when a data channel is closed.
After this call the data channel will not be valid and
can be reused for future created data channels.
--
To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
