Access denied to /dev/ttyUSB0

[Simon Fels]

On 07.09.2016 15:05, Loïc Minier wrote:
> Hi,
> 
> You need to use:
> 
> plugs: [serial-port]
> 
> In your snapcraft.yaml; then you also have to connect your snap to that
> interface manually as it's not autoconnected; check "snap interfaces" to
> see which plugs and slots are connected.

That doesn't work anymore. There is no implicit slot for serial-port.
Right now the only option to get access to serial ports is via defining
a slot on a gadget snap with either a USB product/vendor id pair or a
absolute path to the serial node which then the snap can connect to and
it will only get access to that particular serial port.

You can put something like

slots:
  my-usb-serial-device:
    interface: serial-port
    product-id: 0x0
    vendor-id: 0x0

into your gadget snap and then connect both the snap and gadget together
so your app gets access to that serial node.

In a system where no gadget exists you currently don't get access to
serial nodes. We need to implement hotplut support to make this slots
automatically exported for those devices. Not sure for when this is on
the list.

regards,
Simon

> 
> 
> On Wed, Sep 7, 2016 at 4:00 PM, Jenny Murphy <jenny.murphy at episensor.com
> <mailto:jenny.murphy at episensor.com>> wrote:
> 
>     Hi,
>      I solved the previous issue regarding the use of the RXTX java
>     library and the application is loading and running without errors. 
>     However my java code isn't detecting the port, it should be able to
>     see /dev/ttyUSB0.
> 
>     In the dmesg log I see the following errors :
> 
>     [101043.875139] usb 1-2: new full-speed USB device number 7 using
>     xhci_hcd
>     [101044.006418] usb 1-2: New USB device found, idVendor=10c4,
>     idProduct=ea60
>     [101044.006441] usb 1-2: New USB device strings: Mfr=1, Product=2,
>     SerialNumber=3
>     [101044.006456] usb 1-2: Product: CP2102 USB to UART Bridge Controller
>     [101044.006470] usb 1-2: Manufacturer: Silicon Labs
>     [101044.006482] usb 1-2: SerialNumber: 0001
>     [101044.011589] cp210x 1-2:1.0: cp210x converter detected
>     [101044.012037] usb 1-2: cp210x converter now attached to ttyUSB0
> 
>     [101098.191960] audit_printk_skb: 258 callbacks suppressed
> 
>     [101098.191979] audit: type=1400 audit(1473254849.416:69078):
>     apparmor="DENIED" operation="open"
>     profile="gateway.sideload_main_IdNRFcRcGPGe" name="/dev/ttyUSB0"
>     pid=4875 comm="java" requested_mask="wr" denied_mask="wr" fsuid=0 ouid=0
> 
> 
>     Is there anyway to solve this. I am working on a Ubuntu 15.04 platform.
> 
>     Thanks again.
> 
>     -- 
>     *Jenny Murphy*
>     *EpiSensor, Georges Quay House, Georges Quay, Limerick, Ireland*
>     jenny.murphy at episensor.com <mailto:jenny.murphy at episensor.com>  t |
>     +353 (0) 61 512 511 <tel:%2B353%20%280%29%2061%20512%20511>  w |
>     http://www.episensor.com <http://www.episensor.com/>
> 
>     --
>     Snapcraft mailing list
>     Snapcraft at lists.snapcraft.io <mailto:Snapcraft at lists.snapcraft.io>
>     Modify settings or unsubscribe at:
>     https://lists.ubuntu.com/mailman/listinfo/snapcraft
>     <https://lists.ubuntu.com/mailman/listinfo/snapcraft>
> 
> 
> 
> 
> -- 
> - Loïc
> 
>