Hello All,
Whenever L2cap security is HIGH and remote device does role switch,
Bluez accepts the Role switch and L2cap disconnects the channel
because of HIGH security.
For PAN profile, I would like to keep the L2cap security to HIGH
since it involves internet browsing but the Widcomm stack always does
a role switch in PAN connection and Bluez disconnects l2cap channel.
Can someone please point in specification about the l2cap security
level and Role switch relation. I tried to find out this but I could
not get this behavior described in specification. Please provide your
comments and inputs. Thanks in Advance.
Thanks,
Prabhakaran.
Hi
>-----Original Message-----
>From: Prabhakaran M.C [mailto:[email protected]]
>Sent: Thursday, August 05, 2010 2:44 PM
>To: Rymarkiewicz Waldemar
>Cc: [email protected]
>Subject: Re: L2cap Security And Role Switch
>
>Hi ,
>
>2010/8/5 <[email protected]>:
>> Hi,
>>
>>>-----Original Message-----
>>>From: Prabhakaran M.C [mailto:[email protected]]
>>>Sent: Thursday, August 05, 2010 12:38 PM
>>>To: Rymarkiewicz Waldemar
>>>Cc: [email protected]
>>>Subject: Re: L2cap Security And Role Switch
>>>
>>>Hi Waldek,
>>>
>>>On Thu, Aug 5, 2010 at 3:37 PM,
>>><[email protected]> wrote:
>>>> Hi,
>>>>
>>>>>-----Original Message-----
>>>>>From: [email protected]
>>>>>[mailto:[email protected]] On Behalf Of
>>>>>Prabhakaran M.C
>>>>>Sent: Wednesday, August 04, 2010 4:09 PM
>>>>>To: [email protected]
>>>>>Subject: Reg: L2cap Security And Role Switch
>>>>>
>>>>>Hello All,
>>>>>
>>>>> Whenever L2cap security is HIGH and remote device does
>role switch,
>>>>>Bluez accepts the Role switch and L2cap disconnects the channel
>>>>>because of HIGH security.
>>>>>
>>>>> For PAN profile, I would like to keep the L2cap security to HIGH
>>>>>since it involves internet browsing but the Widcomm stack
>>>always does
>>>>>a role switch in PAN connection and Bluez disconnects
>l2cap channel.
>>>>>
>>>>> Can someone please point in specification about the l2cap
>security
>>>>>level and Role switch relation. I tried to find out this
>but I could
>>>>>not get this behavior described in specification. Please
>>>provide your
>>>>>comments and inputs. Thanks in Advance.
>>>>>
>>>>>Thanks,
>>>>>Prabhakaran.
>>>>>--
>>>>
>>>> Note that HIGH sec level requires encription on the link.
>>>Role switch procedure turn off ?the encription before it starts
>>>switching roles and turn on it again after all. In 2.1 spec the
>>>controller handles switching off/on encription (pause/resume).
>>>>
>>>> Thanks,
>>>> /Waldek
>>>
>>> From the logs, the link was authenticated and encrypted.
>>>Then Widcomm stack disables the encryption, does a role switch,
>>>enables the encryption.
>>>After role switch bluez kernel disconnects l2cap channel due to HIGH
>>>security. I just want to know where this disconnection part
>is defined
>>>in spec. Or Bluez has to just reject the role switch
>operation instead
>>>of disconnection?
>>>
>>>--
>>>Thanks,
>>>Prabhakaran.
>>
>> As far as I know it's not defined in the spec. It's simply
>Bluez design. What I would like to see, the bluez should block
>outgoing data flow in l2cap for the period of role switch.
>> It's done in rfcomm this way, I guess (?).
>>
>> I agree, in my view the current desing in this use case is
>not perfect.
>>
>> Thanks,
>> /Waldek
>>
>>
>>
>>
>>
>>
>>
>
>Thanks for your response.
>One small correction here (My Bad). The l2cap channel is
>getting closed because encryption of the link goes down during
>role switch.
>"l2cap_check_encryption" function validates the encryption, if
>it is disabled and security is high then channel is getting
>closed by this function. Please let me know your comments about this.
>
>--
>Thanks,
>Prabhakaran.
As I said, if the encryption is disabled due to role switch, l2cap should block data flow and wait some time when the encription is switched on again. If this will not occur l2cap shoudl close the channel otherwise should continue as before the role switch.
Thanks,
/Waldek
Hi ,
2010/8/5 <[email protected]>:
> Hi,
>
>>-----Original Message-----
>>From: Prabhakaran M.C [mailto:[email protected]]
>>Sent: Thursday, August 05, 2010 12:38 PM
>>To: Rymarkiewicz Waldemar
>>Cc: [email protected]
>>Subject: Re: L2cap Security And Role Switch
>>
>>Hi Waldek,
>>
>>On Thu, Aug 5, 2010 at 3:37 PM,
>><[email protected]> wrote:
>>> Hi,
>>>
>>>>-----Original Message-----
>>>>From: [email protected]
>>>>[mailto:[email protected]] On Behalf Of
>>>>Prabhakaran M.C
>>>>Sent: Wednesday, August 04, 2010 4:09 PM
>>>>To: [email protected]
>>>>Subject: Reg: L2cap Security And Role Switch
>>>>
>>>>Hello All,
>>>>
>>>> Whenever L2cap security is HIGH and remote device does role switch,
>>>>Bluez accepts the Role switch and L2cap disconnects the channel
>>>>because of HIGH security.
>>>>
>>>> For PAN profile, I would like to keep the L2cap security to HIGH
>>>>since it involves internet browsing but the Widcomm stack
>>always does
>>>>a role switch in PAN connection and Bluez disconnects l2cap channel.
>>>>
>>>> Can someone please point in specification about the l2cap security
>>>>level and Role switch relation. I tried to find out this but I could
>>>>not get this behavior described in specification. Please
>>provide your
>>>>comments and inputs. Thanks in Advance.
>>>>
>>>>Thanks,
>>>>Prabhakaran.
>>>>--
>>>
>>> Note that HIGH sec level requires encription on the link.
>>Role switch procedure turn off ?the encription before it
>>starts switching roles and turn on it again after all. In 2.1
>>spec the controller handles switching off/on encription (pause/resume).
>>>
>>> Thanks,
>>> /Waldek
>>
>> From the logs, the link was authenticated and encrypted.
>>Then Widcomm stack disables the encryption, does a role
>>switch, enables the encryption.
>>After role switch bluez kernel disconnects l2cap channel due
>>to HIGH security. I just want to know where this disconnection
>>part is defined in spec. Or Bluez has to just reject the role
>>switch operation instead of disconnection?
>>
>>--
>>Thanks,
>>Prabhakaran.
>
> As far as I know it's not defined in the spec. It's simply Bluez design. What I would like to see, the bluez should block outgoing data flow in l2cap for the period of role switch.
> It's done in rfcomm this way, I guess (?).
>
> I agree, in my view the current desing in this use case is not perfect.
>
> Thanks,
> /Waldek
>
>
>
>
>
>
>
Thanks for your response.
One small correction here (My Bad). The l2cap channel is getting
closed because encryption of the link goes down during role switch.
"l2cap_check_encryption" function validates the encryption, if it is
disabled and security is high then channel is getting closed by this
function. Please let me know your comments about this.
--
Thanks,
Prabhakaran.
Hi,
>-----Original Message-----
>From: Prabhakaran M.C [mailto:[email protected]]
>Sent: Thursday, August 05, 2010 12:38 PM
>To: Rymarkiewicz Waldemar
>Cc: [email protected]
>Subject: Re: L2cap Security And Role Switch
>
>Hi Waldek,
>
>On Thu, Aug 5, 2010 at 3:37 PM,
><[email protected]> wrote:
>> Hi,
>>
>>>-----Original Message-----
>>>From: [email protected]
>>>[mailto:[email protected]] On Behalf Of
>>>Prabhakaran M.C
>>>Sent: Wednesday, August 04, 2010 4:09 PM
>>>To: [email protected]
>>>Subject: Reg: L2cap Security And Role Switch
>>>
>>>Hello All,
>>>
>>> Whenever L2cap security is HIGH and remote device does role switch,
>>>Bluez accepts the Role switch and L2cap disconnects the channel
>>>because of HIGH security.
>>>
>>> For PAN profile, I would like to keep the L2cap security to HIGH
>>>since it involves internet browsing but the Widcomm stack
>always does
>>>a role switch in PAN connection and Bluez disconnects l2cap channel.
>>>
>>> Can someone please point in specification about the l2cap security
>>>level and Role switch relation. I tried to find out this but I could
>>>not get this behavior described in specification. Please
>provide your
>>>comments and inputs. Thanks in Advance.
>>>
>>>Thanks,
>>>Prabhakaran.
>>>--
>>
>> Note that HIGH sec level requires encription on the link.
>Role switch procedure turn off ?the encription before it
>starts switching roles and turn on it again after all. In 2.1
>spec the controller handles switching off/on encription (pause/resume).
>>
>> Thanks,
>> /Waldek
>
> From the logs, the link was authenticated and encrypted.
>Then Widcomm stack disables the encryption, does a role
>switch, enables the encryption.
>After role switch bluez kernel disconnects l2cap channel due
>to HIGH security. I just want to know where this disconnection
>part is defined in spec. Or Bluez has to just reject the role
>switch operation instead of disconnection?
>
>--
>Thanks,
>Prabhakaran.
As far as I know it's not defined in the spec. It's simply Bluez design. What I would like to see, the bluez should block outgoing data flow in l2cap for the period of role switch.
It's done in rfcomm this way, I guess (?).
I agree, in my view the current desing in this use case is not perfect.
Thanks,
/Waldek
Hi Waldek,
On Thu, Aug 5, 2010 at 3:37 PM, <[email protected]> wrote:
> Hi,
>
>>-----Original Message-----
>>From: [email protected]
>>[mailto:[email protected]] On Behalf Of
>>Prabhakaran M.C
>>Sent: Wednesday, August 04, 2010 4:09 PM
>>To: [email protected]
>>Subject: Reg: L2cap Security And Role Switch
>>
>>Hello All,
>>
>> Whenever L2cap security is HIGH and remote device does role
>>switch, Bluez accepts the Role switch and L2cap disconnects
>>the channel because of HIGH security.
>>
>> For PAN profile, I would like to keep the L2cap security to
>>HIGH since it involves internet browsing but the Widcomm stack
>>always does a role switch in PAN connection and Bluez
>>disconnects l2cap channel.
>>
>> Can someone please point in specification about the l2cap
>>security level and Role switch relation. I tried to find out
>>this but I could not get this behavior described in
>>specification. Please provide your comments and inputs. Thanks
>>in Advance.
>>
>>Thanks,
>>Prabhakaran.
>>--
>
> Note that HIGH sec level requires encription on the link. Role switch procedure turn off ?the encription before it starts switching roles and turn on it again after all. In 2.1 spec the controller handles switching off/on encription (pause/resume).
>
> Thanks,
> /Waldek
From the logs, the link was authenticated and encrypted.
Then Widcomm stack disables the encryption, does a role switch,
enables the encryption.
After role switch bluez kernel disconnects l2cap channel due to HIGH
security. I just want to know where this disconnection part is defined
in spec. Or Bluez has to just reject the role switch operation instead
of disconnection?
--
Thanks,
Prabhakaran.
Hi,
>-----Original Message-----
>From: [email protected]
>[mailto:[email protected]] On Behalf Of
>Prabhakaran M.C
>Sent: Wednesday, August 04, 2010 4:09 PM
>To: [email protected]
>Subject: Reg: L2cap Security And Role Switch
>
>Hello All,
>
> Whenever L2cap security is HIGH and remote device does role
>switch, Bluez accepts the Role switch and L2cap disconnects
>the channel because of HIGH security.
>
> For PAN profile, I would like to keep the L2cap security to
>HIGH since it involves internet browsing but the Widcomm stack
>always does a role switch in PAN connection and Bluez
>disconnects l2cap channel.
>
> Can someone please point in specification about the l2cap
>security level and Role switch relation. I tried to find out
>this but I could not get this behavior described in
>specification. Please provide your comments and inputs. Thanks
>in Advance.
>
>Thanks,
>Prabhakaran.
>--
Note that HIGH sec level requires encription on the link. Role switch procedure turn off the encription before it starts switching roles and turn on it again after all. In 2.1 spec the controller handles switching off/on encription (pause/resume).
Thanks,
/Waldek