Merge 6f5da9c6ac into e430dbfe67

BluetoothHID.py

@@ -1,9 +1,19 @@
+import bluetooth    # requires pybluez package
 import dbus
 import dbus.service
 import os
 import socket
 
 
+# see section "2.5 PSMs and SPSMs": https://www.bluetooth.com/wp-content/uploads/Files/Specification/HTML/Assigned_Numbers/out/en/Assigned_Numbers.pdf
+BLUETOOTH_PORT_HID_CONTROL = 0x0011
+BLUETOOTH_PORT_HID_INTERRUPT = 0x0013
+
+# see section "3.3 SDP Service Class and Profile Identifiers"  of https://www.bluetooth.com/wp-content/uploads/Files/Specification/HTML/Assigned_Numbers/out/en/Assigned_Numbers.pdf
+# and Vol 3, Part B, section 2.5.1 of https://www.bluetooth.com/specifications/specs/core-specification-5-3/
+BLUETOOT_PROFILE_HID = "00001124-0000-1000-8000-00805f9b34fb"
+
+
 class BluetoothHIDProfile(dbus.service.Object):
     def __init__(self, bus, path):
         super(BluetoothHIDProfile, self).__init__(bus, path)
@@ -42,40 +52,54 @@ def error_handler(e):
 
 
 class BluetoothHIDService(object):
-    PROFILE_PATH = "/org/bluez/bthid_profile"
+    PROFILE_PATH = "/org/bluez/emubthid_profile"
 
     HOST = 0
     PORT = 1
 
     def __init__(self, service_record, MAC):
-        self.P_CTRL = 0x0011
-        self.P_INTR = 0x0013
+        if not bluetooth.is_valid_address(MAC):
+            raise ValueError(f"'{MAC}' is not a valid MAC address")
+
         self.SELFMAC = MAC
+
         bus = dbus.SystemBus()
         bluez_obj = bus.get_object("org.bluez", "/org/bluez")
         manager = dbus.Interface(bluez_obj, "org.bluez.ProfileManager1")
 
         BluetoothHIDProfile(bus, self.PROFILE_PATH)
-        opts = {
-            "ServiceRecord": service_record,
-            "Name": "BTKeyboardProfile",
-            "RequireAuthentication": False,
-            "RequireAuthorization": False,
-            "Service": "MY BTKBD",
-            "Role": "server"
-        }
 
-        sock_control = socket.socket(socket.AF_BLUETOOTH, socket.SOCK_SEQPACKET, socket.BTPROTO_L2CAP)
-        sock_control.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-        sock_inter = socket.socket(socket.AF_BLUETOOTH, socket.SOCK_SEQPACKET, socket.BTPROTO_L2CAP)
-        sock_inter.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-        sock_control.bind((self.SELFMAC, self.P_CTRL))
-        sock_inter.bind((self.SELFMAC, self.P_INTR))
-        manager.RegisterProfile(self.PROFILE_PATH, "00001124-0000-1000-8000-00805f9b34fb", opts)
-        print("Registered")
+        sock_control = L2CAPSocket(True)
+        sock_inter = L2CAPSocket(True)
+
+        # The PSM parameter sets the bluetooth "port" for L2CAP connections
+        # "Valid values in the first range are assigned by the Bluetooth SIG and indicate protocols."
+        # https://www.bluetooth.com/wp-content/uploads/Files/Specification/HTML/Core-54/out/en/host/logical-link-control-and-adaptation-protocol-specification.html
+        sock_control.bind((self.SELFMAC, BLUETOOTH_PORT_HID_CONTROL))
+        sock_inter.bind((self.SELFMAC, BLUETOOTH_PORT_HID_INTERRUPT))
+
+        # IDEs dont see this function because bluetooth.BluetoothSocket imports them dynamically
         sock_control.listen(1)
         sock_inter.listen(1)
-        print(f"waiting for connection at controller {MAC}, please double check with the MAC in bluetoothctl")
+
+        manager.RegisterProfile(self.PROFILE_PATH, BLUETOOT_PROFILE_HID, {
+            "Name": "Emulated Bluetooth keyboard",
+            # "Service": "MY BTKBD", # this refers to the bluetooth spec service class uuid
+            "Role": "server",
+            "RequireAuthentication": True,
+            "RequireAuthorization": True,
+            "ServiceRecord": service_record,
+            # note: it seems as if socket creation could be replaced with working through DBus (see PSM option and NewConnection function).
+            # maybe currently the conenction is somehow handled at 2 places at the same time?
+            #
+            # https://www.bluez.org/bluez-5-api-introduction-and-porting-guide/
+            # "The new Profile1 interface (and removal of org.bluez.Service)"
+        })
+
+        print("Registered Bluetooth HID profile in Bluez")
+
+        print(f"Waiting for connection at controller {MAC}, please double check with the MAC in bluetoothctl")
+
         self.ccontrol, cinfo = sock_control.accept()
         print("Control channel connected to " + cinfo[self.HOST])
         self.cinter, cinfo = sock_inter.accept()
@@ -83,3 +107,13 @@ class BluetoothHIDService(object):
 
     def send(self, bytes_buf):
         self.cinter.send(bytes_buf)
+
+
+# https://github.com/karulis/pybluez/blob/master/examples/simple/l2capserver.py
+class L2CAPSocket(bluetooth.BluetoothSocket):
+
+    def __init__(self, reuseaddr: False):
+        super().__init__(bluetooth.L2CAP)
+
+        if reuseaddr:
+            self.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

README.md

@@ -33,10 +33,6 @@ The client who uses the emulated HID device is an android 9 phone.
 
 ## How to Use
 
-### (IMPORTANT) Update the bluetooth controller MAC in `main.py`
-
-Edit `main.py` and change the `CONTROLLER_MAC` variable in the beginning to your own MAC. You can find the MAC of the bluetooth controller in `bluetoothctl`. E.g. the "5C:87:9C:96:BE:5E" shown in the screenshot below is the MAC.
-
 ### Enable bluetooth
 
 1. make sure that bluetoothd has the plugin `input` disabled (i.e. "-P input").
@@ -67,7 +63,7 @@ Edit `main.py` and change the `CONTROLLER_MAC` variable in the beginning to your
 
 5. Run `xhost +` to enable root user also draw something on a non-root user's X session. (see [this stackoverflow](https://stackoverflow.com/questions/31902846/how-to-fix-error-xlib-error-displayconnectionerror-cant-connect-to-display-0))
 
-6. Run `sudo python3 main.py`
+6. Run `sudo python3 main.py <BT controller MAC address>`
 
 In bluetoothctl, it should look like this, where a lot of UUIDs are registered
 

main.py

@@ -1,19 +1,12 @@
 #!/usr/bin/python3
 
 import sys
-import os
-import time
 from BluetoothHID import BluetoothHIDService
 from evdev_xkb_map import evdev_xkb_map, modkeys
 import keymap
 from Xlib import X, display, Xutil
 from dbus.mainloop.glib import DBusGMainLoop
 
-"""
-Change this CONTROLLER_MAC to the mac of your own device
-"""
-CONTROLLER_MAC = "5C:87:9C:96:BE:5E"
-
 usbhid_map = {}
 with open("keycode.txt") as f:
     for line in f.read().splitlines():
@@ -222,13 +215,22 @@ class Window(object):
                 else:
                     prev_y = e.event_y
 
+
 if __name__ == '__main__':
+    try:
+        bt_controller_mac = sys.argv[1]
+    except IndexError:
+        print("You need to pass the MAC address of your Bluetooth controller in the first argument.")
+        print("You can find the MAC of the bluetooth controller in `bluetoothctl`. In its format it is similar to \"5C:87:9C:96:BE:5E\".")
+        exit(1)
+
     DBusGMainLoop(set_as_default=True)
     service_record = open("sdp_record_kbd.xml").read()
     d = display.Display()
     d.change_keyboard_control(auto_repeat_mode=X.AutoRepeatModeOff)
+
     try:
-        bthid_srv = BluetoothHIDService(service_record, CONTROLLER_MAC)
+        bthid_srv = BluetoothHIDService(service_record, bt_controller_mac)
         Window(d).loop(bthid_srv.send)
         #Window(d).loop(print)
     finally: