Python opp obex server using Bluez-obex and pydbus?

Question

For my project, I need to downlink .zip files over Bluetooth. I am using python and obex for this. I have a working python opp client implemented (shout-out to ukBaz for the help), but I am still using os to start the server, so the rest of my server program has no idea when a file is received. The rest of the program is completed, but without output from the server, I can't trigger the unzip function to run. I've read the bluez-obex API documentation and there doesn't seem to be anything on starting a server. Is there another way of doing this? My code is below.

os.system("sudo obexpushd -B -o /home/pi/Desktop/ -n")

Answer 1

I am not familiar with obexpushd and what it gives you over using the functionality that is there with obexd.

My understanding is that you need to create an obex-agent to accept/reject a Bluetooth object push request with obexd.

Monitoring the InterfacesAdded DBus signal should give you the information that you need to know when a transfer has started. You can then monitor the PropertiesChanged signal for when the status changes.

I was able to push a photo from my phone to a Raspberry Pi with the following running on the RPi (I had my phone and RPi already paired):

from gi.repository import GLib
import pydbus

BUS_NAME = 'org.bluez.obex'
PATH = '/org/bluez/obex'
AGENT_MANAGER_INTERFACE = 'org.bluez.obex.AgentManager1'
AGENT_INTERFACE = 'org.bluez.obex.Agent1'
SESSION_INTERFACE = 'org.bluez.obex.Session1'
TRANSFER_INTERFACE = 'org.bluez.obex.Transfer1'

ses_bus = pydbus.SessionBus()


def transfer_status_handler(iface, props_changed, props_removed):
    if iface == TRANSFER_INTERFACE:
        status = props_changed.get('Status')
        if status == 'complete':
            print('Transfer complete')
        elif status == 'queued':
            print('Still queued')
        elif status == 'active':
            print('transferring')
        elif status == 'suspended':
            print('Suspended')
        elif status == 'error':
            print('error')

def iface_added_handler(dbus_path, interfaces):
    if SESSION_INTERFACE in interfaces and 'server' in dbus_path:
        print('Server session added')
    elif TRANSFER_INTERFACE in interfaces and 'server' in dbus_path:
        print('Transfer started')
        transfer = ses_bus.get(BUS_NAME, dbus_path)
        transfer.onPropertiesChanged = transfer_status_handler


class Agent:
    """
      <node>
        <interface name='org.bluez.obex.Agent1'>
          <method name='Release'>
          </method>
          <method name='AuthorizePush'>
            <arg type='s' name='path' direction='out'/>
            <arg type='o' name='transfer' direction='in'/>
          </method>
          <method name='Cancel'>
          </method>
        </interface>
      </node>
    """
    def AuthorizePush(self, path):
        print('Authorize Push', path)
        transfer = ses_bus.get(BUS_NAME, path)
        props = transfer.GetAll(TRANSFER_INTERFACE)
        print(props)
        return props.get('Name')

    def Cancel(self):
        print('Authorization Cancelled')

    def Release(self):
        pass


if __name__ == '__main__':
    obex_mngr = ses_bus.get('org.bluez.obex', '/')
    obex_mngr.onInterfacesAdded = iface_added_handler
    mainloop = GLib.MainLoop()
    ses_bus.register_object('/test/agent', Agent(), None)
    print('Agent created')
    agnt_mngr = ses_bus.get(BUS_NAME, PATH)
    agnt_mngr.RegisterAgent('/test/agent')
    print('Agent registered')
    try:
        mainloop.run()
    except KeyboardInterrupt:
        mainloop.quit()

This code just accepts any request that is made of it. This is probably a bad thing to do and people might want to add some checking (or prompt the user) if the file should be accepted.