Re: Bluetooth printer connection error

[Laurent Vivier <laurent@vivier.eu>]

Le 09/12/2020 à 21:27, Bastien Nocera a écrit :
> On Wed, 2020-12-09 at 20:04 +0100, Laurent Vivier wrote:
>> Le 09/12/2020 à 12:34, Bastien Nocera a écrit :
>>> On Wed, 2020-12-09 at 12:14 +0100, Laurent Vivier wrote:
>> ...
>>>>> If the printer has uses the SPP or HCRP printing profiles, you
>>>>> should
>>>>> see it when using:
>>>>> /usr/lib/cups/backend/bluetooth
>>>>> without any arguments.
>>>>
>>>> As I don't see it once it is paired, I guess it is not using one
>>>> of
>>>> these profiles.
>>>
>>> I don't remember how this used to work, but you'll probably only
>>> see
>>> something if the printer is visible.
>>>
>>> You might be able to get the printer to work by adding:
>>> bluetooth://DC0D309023C7
>>> as a printer in the printer settings of your favourite desktop
>>> environment, if it actually uses SPP.
>>>
>>> running the cups backend with:
>>> /usr/lib/cups/backend/bluetooth --get-deviceid
>>> bluetooth://DC0D309023C7
>>>
>>> should show you whether it can get autoconfigured for CUPS use.
>>>
>>
>> Thank you Bastien, it's exactly what I needed to know.
>>
>> Correct me if I'm wrong but it seems there is a bug in the
>> cups/bluetooth
>> command:
> 
> Sigh. No, it's not a bug, it's just that the cups tool was never ported
> from the bluez 4.x to the current bluez 5.x API...
> 
> Until that's ported (if ever, given the low number of Bluetooth
> printers around...), you could try to extract the IEEE1284 ID using:
> sdptool records DC:0D:30:90:23:C7

$ sdptool records DC:0D:30:90:23:C7
Service Name: SPP Dev
Service RecHandle: 0x10001
Service Class ID List:
  "Serial Port" (0x1101)
Protocol Descriptor List:
  "L2CAP" (0x0100)
  "RFCOMM" (0x0003)
    Channel: 1
Language Base Attr List:
  code_ISO639: 0x656e
  encoding:    0x6a
  base_offset: 0x100

It doesn't seem to provide an IEEE1284 ID.

> 
> But I'm not certain that this working is necessary to actually try a
> print. Have you tested that?
> 

Not sure what to do...

If I try to add the printer using the GUI, it doesn't appear in the list and I cannot add it
manually (Fedora 33/GNOME 3.38.2) in GUI.

If I add it with the following command line:

  lpadmin -p M02 -E -v bluetooth://DC0D309023C7 -P /usr/share/cups/model/Phomemo/Phomemo-M02.ppd.gz

It doesn't print anything.

But I had some selinux related error:

setroubleshoot[13488]: SELinux interdit à bluetooth d'utiliser l'accès connect sur le
bluetooth_socket Inconnu.Pour des messages SELinux exhaustifs, lancez sealert -l
965e2270-948f-4791-93f0-3b856c162cea
setroubleshoot[13488]: SELinux interdit à bluetooth d'utiliser l'accès connect sur le
bluetooth_socket Inconnu.
...

So I ran:

  ausearch -c "bluetooth" --raw | audit2allow -M my-bluetooth
  semodule -X 300 -i my-bluetooth.pp

And now what I have in the syslogs is:

cupsd[1185]: REQUEST localhost - - "POST /printers/M02 HTTP/1.1" 200 499560 Print-Job successful-ok
DC0D309023C7[14310]: sdp_send_req_w4_rsp: Error sending data:Permission denied
DC0D309023C7[14310]: sdp_service_search_attr_req: Unexpected end of packet
DC0D309023C7[14310]: sdp_send_req_w4_rsp: Error sending data:Permission denied
DC0D309023C7[14310]: sdp_service_search_attr_req: Unexpected end of packet
cupsd[1185]: Can\'t get service information
DC0D309023C7[14310]: sdp_send_req_w4_rsp: Error sending data:Permission denied
DC0D309023C7[14310]: sdp_service_search_attr_req: Unexpected end of packet

Thanks,
Laurent