rfcomm bluetooth permission denied error raspberry pi

Question

I'm using a bluetooth dongle to try and send information from ubuntu 15.04 to raspberry pi b+ running the latest debian jessie image. I'm just following the http://people.csail.mit.edu/albert/bluez-intro/ tutorial. I got the simple RFCOMM and L2CAP protocols working. I'm having trouble running the SDP protocol. The server code is -

from bluetooth import *

server_sock = BluetoothSocket(RFCOMM)
server_sock.bind(("", PORT_ANY))
server_sock.listen(1)

advertise_service(server_sock, "SampleServer",service_classes=[SERIAL_PORT_CLASS], profiles=[SERIAL_PORT_PROFILE])

client_sock, client_info = server_sock.accept()

print "connection from: ", client_info

client_sock.send("PyBluez server says Hello!")
data = client_sock.recv(1024)
print "received: ", data

client_sock.close()
server_sock.close()

The error I'm getting is -

Traceback (most recent call last):
  File "rfcomm-server.py", line 7, in <module>
    advertise_service(server_sock, "SampleServer",service_classes=[SERIAL_PORT_CLASS], profiles=[SERIAL_PORT_PROFILE])
  File "/usr/lib/python2.7/dist-packages/bluetooth/bluez.py", line 176, in advertise_service
    raise BluetoothError (str (e))
bluetooth.btcommon.BluetoothError: (13, 'Permission denied')

Here are some steps I have taken-

Add the user 'pi' to lp group
run piscan on hciconfig hci0
Add --compat option to bluetoothd in bluetooth.service

Any help would be appreciated. Thanks!

I should hit myself on the head. Sometimes the solution is that simple! — Ankit Sharma, Jan 04 '16 at 21:08
Running as root will not work if the `pip` install is local to user. The simplest way to solve this is `sudo chmod o+rw /var/run/sdp`. And from here, improve it accordingly. No huzz fuzz. This is the direct solution. — daparic, Oct 14 '21 at 13:51

score 19 · Answer 1 · edited Apr 13 '17 at 12:36

Running your script as root kinda works, but it's not a good practice.

According to this thread, you just need to adjust permissions to the /var/run/sdp file (which is created when using the --compat switch).

So, to prevent link rot I'm reproducing dlech's post and adapting it to Raspberry Pi:

make sure your pi user is in the bluetooth group:

$ cat /etc/group | grep bluetooth
bluetooth:x:113:pi

1.1. If it's not, add pi to bluetooth group:

$ sudo usermod -G bluetooth -a pi

Change group of the /var/run/sdp file:
```
$ sudo chgrp bluetooth /var/run/sdp
```

To make the change persistent after reboot:

3.1. Create file /etc/systemd/system/var-run-sdp.path with the following content:

[Unit]
Descrption=Monitor /var/run/sdp

[Install]
WantedBy=bluetooth.service

[Path]
PathExists=/var/run/sdp
Unit=var-run-sdp.service

3.2. And another file, /etc/systemd/system/var-run-sdp.service:

[Unit]
Description=Set permission of /var/run/sdp

[Install]
RequiredBy=var-run-sdp.path

[Service]
Type=simple
ExecStart=/bin/chgrp bluetooth /var/run/sdp

3.3. Finally, start it all up:

sudo systemctl daemon-reload
sudo systemctl enable var-run-sdp.path
sudo systemctl enable var-run-sdp.service
sudo systemctl start var-run-sdp.path

Credit goes to user dlech who "figured it out" originally.

You need to modify the service file to include: `ExecStartPost=/bin/chmod 662 /var/run/sdp`. This worked for me — Jonno_FTW, Jul 21 '17 at 02:09

score 2 · Answer 2 · answered Feb 05 '22 at 15:16

2

This solution worked for me:

sudo chmod o+rw /var/run/sdp

Thanks @eigenfield

answered Feb 05 '22 at 15:16

ucefM

21
2

score -3 · Answer 3 · edited Dec 04 '17 at 02:24

-3

And sudo does the job.

sudo python script.py

edited Dec 04 '17 at 02:24

Anik Islam Abhi

25,137
8
58
80

answered Jan 04 '16 at 21:09

Ankit Sharma

663
1
5
17

rfcomm bluetooth permission denied error raspberry pi

3 Answers3

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