better/safer Linux recommendations

use arg-less main() functions in all scripts

apps/show.py

@@ -90,7 +90,7 @@ class SnoopPacketReader:
 @click.command()
 @click.option('--format', type=click.Choice(['h4', 'snoop']), default='h4', help='Format of the input file')
 @click.argument('filename')
-def show(format, filename):
+def main(format, filename):
     input = open(filename, 'rb')
     if format == 'h4':
         packet_reader = PacketReader(input)
@@ -117,4 +117,4 @@ def show(format, filename):
 
 # -----------------------------------------------------------------------------
 if __name__ == '__main__':
-    show()
+    main()

apps/usb_probe.py

@@ -28,6 +28,8 @@
 # -----------------------------------------------------------------------------
 import os
 import logging
+import sys
+import click
 import usb1
 from colors import color
 
@@ -35,6 +37,7 @@ from colors import color
 # -----------------------------------------------------------------------------
 # Constants
 # -----------------------------------------------------------------------------
+USB_DEVICE_CLASS_DEVICE                          = 0x00
 USB_DEVICE_CLASS_WIRELESS_CONTROLLER             = 0xE0
 USB_DEVICE_SUBCLASS_RF_CONTROLLER                = 0x01
 USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER = 0x01
@@ -75,9 +78,81 @@ USB_DEVICE_CLASSES = {
     0xFF: 'Vendor Specific'
 }
 
+USB_ENDPOINT_IN    = 0x80
+USB_ENDPOINT_TYPES = ['CONTROL', 'ISOCHRONOUS', 'BULK', 'INTERRUPT']
+
+USB_BT_HCI_CLASS_TUPLE = (
+    USB_DEVICE_CLASS_WIRELESS_CONTROLLER,
+    USB_DEVICE_SUBCLASS_RF_CONTROLLER,
+    USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER
+)
+
 
 # -----------------------------------------------------------------------------
-def main():
+def show_device_details(device):
+    for configuration in device:
+        print(f'  Configuration {configuration.getConfigurationValue()}')
+        for interface in configuration:
+            for setting in interface:
+                alternateSetting = setting.getAlternateSetting()
+                suffix = f'/{alternateSetting}' if interface.getNumSettings() > 1 else ''
+                (class_string, subclass_string) = get_class_info(
+                    setting.getClass(),
+                    setting.getSubClass(),
+                    setting.getProtocol()
+                )
+                details = f'({class_string}, {subclass_string})'
+                print(f'      Interface: {setting.getNumber()}{suffix} {details}')
+                for endpoint in setting:
+                    endpoint_type = USB_ENDPOINT_TYPES[endpoint.getAttributes() & 3]
+                    endpoint_direction = 'OUT' if (endpoint.getAddress() & USB_ENDPOINT_IN == 0) else 'IN'
+                    print(f'        Endpoint 0x{endpoint.getAddress():02X}: {endpoint_type} {endpoint_direction}')
+
+
+# -----------------------------------------------------------------------------
+def get_class_info(cls, subclass, protocol):
+    class_info = USB_DEVICE_CLASSES.get(cls)
+    protocol_string = ''
+    if class_info is None:
+        class_string = f'0x{cls:02X}'
+    else:
+        if type(class_info) is tuple:
+            class_string = class_info[0]
+            subclass_info = class_info[1].get(subclass)
+            if subclass_info:
+                protocol_string = subclass_info.get(protocol)
+                if protocol_string is not None:
+                    protocol_string = f' [{protocol_string}]'
+
+        else:
+            class_string = class_info
+
+    subclass_string = f'{subclass}/{protocol}{protocol_string}'
+
+    return (class_string, subclass_string)
+
+
+# -----------------------------------------------------------------------------
+def is_bluetooth_hci(device):
+    # Check if the device class indicates a match
+    if (device.getDeviceClass(), device.getDeviceSubClass(), device.getDeviceProtocol()) == USB_BT_HCI_CLASS_TUPLE:
+        return True
+
+    # If the device class is 'Device', look for a matching interface
+    if device.getDeviceClass() == USB_DEVICE_CLASS_DEVICE:
+        for configuration in device:
+            for interface in configuration:
+                for setting in interface:
+                    if (setting.getClass(), setting.getSubClass(), setting.getProtocol()) == USB_BT_HCI_CLASS_TUPLE:
+                        return True
+
+    return False
+
+
+# -----------------------------------------------------------------------------
+@click.command()
+@click.option('--verbose', is_flag=True, default=False, help='Print more details')
+def main(verbose):
     logging.basicConfig(level = os.environ.get('BUMBLE_LOGLEVEL', 'WARNING').upper())
 
     with usb1.USBContext() as context:
@@ -91,23 +166,28 @@ def main():
 
             device_id = (device.getVendorID(), device.getProductID())
 
-            device_is_bluetooth_hci = (
+            (device_class_string, device_subclass_string) = get_class_info(
-                device_class    == USB_DEVICE_CLASS_WIRELESS_CONTROLLER and
+                device_class,
-                device_subclass == USB_DEVICE_SUBCLASS_RF_CONTROLLER and
+                device_subclass,
-                device_protocol == USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER
+                device_protocol
             )
 
-            device_class_details = ''
+            try:
-            device_class_info    = USB_DEVICE_CLASSES.get(device_class)
+                device_serial_number = device.getSerialNumber()
-            if device_class_info is not None:
+            except usb1.USBError:
-                if type(device_class_info) is tuple:
+                device_serial_number = None
-                    device_class = device_class_info[0]
-                    device_subclass_info = device_class_info[1].get(device_subclass)
-                    if device_subclass_info:
-                        device_class_details = f' [{device_subclass_info.get(device_protocol)}]'
-                else:
-                    device_class = device_class_info
 
+            try:
+                device_manufacturer = device.getManufacturer()
+            except usb1.USBError:
+                device_manufacturer = None
+
+            try:
+                device_product = device.getProduct()
+            except usb1.USBError:
+                device_product = None
+
+            device_is_bluetooth_hci = is_bluetooth_hci(device)
             if device_is_bluetooth_hci:
                 bluetooth_device_count += 1
                 fg_color = 'black'
@@ -123,33 +203,35 @@ def main():
             if device_is_bluetooth_hci:
                 bumble_transport_names.append(f'usb:{bluetooth_device_count - 1}')
 
-            serial_number_collision = False
-            if device_id in devices:
-                for device_serial in devices[device_id]:
-                    if device_serial == device.getSerialNumber():
-                        serial_number_collision = True
-
             if device_id not in devices:
                 bumble_transport_names.append(basic_transport_name)
             else:
                 bumble_transport_names.append(f'{basic_transport_name}#{len(devices[device_id])}')
 
-            if device.getSerialNumber() and not serial_number_collision:
+            if device_serial_number is not None:
-                bumble_transport_names.append(f'{basic_transport_name}/{device.getSerialNumber()}')
+                if device_id not in devices or device_serial_number not in devices[device_id]:
+                    bumble_transport_names.append(f'{basic_transport_name}/{device_serial_number}')
 
+            # Print the results
             print(color(f'ID {device.getVendorID():04X}:{device.getProductID():04X}', fg=fg_color, bg=bg_color))
             if bumble_transport_names:
                 print(color('  Bumble Transport Names:', 'blue'), ' or '.join(color(x, 'cyan' if device_is_bluetooth_hci else 'red') for x in bumble_transport_names))
             print(color('  Bus/Device:            ', 'green'), f'{device.getBusNumber():03}/{device.getDeviceAddress():03}')
-            if device.getSerialNumber():
+            print(color('  Class:                 ', 'green'), device_class_string)
-                print(color('  Serial:                ', 'green'), device.getSerialNumber())
+            print(color('  Subclass/Protocol:     ', 'green'), device_subclass_string)
-            print(color('  Class:                 ', 'green'), device_class)
+            if device_serial_number is not None:
-            print(color('  Subclass/Protocol:     ', 'green'), f'{device_subclass}/{device_protocol}{device_class_details}')
+                print(color('  Serial:                ', 'green'), device_serial_number)
-            print(color('  Manufacturer:          ', 'green'), device.getManufacturer())
+            if device_manufacturer is not None:
-            print(color('  Product:               ', 'green'), device.getProduct())
+                print(color('  Manufacturer:          ', 'green'), device_manufacturer)
+            if device_product is not None:
+                print(color('  Product:               ', 'green'), device_product)
+
+            if verbose:
+                show_device_details(device)
+
             print()
 
-            devices.setdefault(device_id, []).append(device.getSerialNumber())
+            devices.setdefault(device_id, []).append(device_serial_number)
 
 
 # -----------------------------------------------------------------------------

bumble/transport/usb.py

@@ -36,7 +36,7 @@ logger = logging.getLogger(__name__)
 async def open_usb_transport(spec):
     '''
     Open a USB transport.
-    The parameter string has this syntax:
+    The moniker string has this syntax:
     either <index> or
     <vendor>:<product> or
     <vendor>:<product>/<serial-number>] or
@@ -47,15 +47,21 @@ async def open_usb_transport(spec):
     /<serial-number> suffix or #<index> suffix max be specified when more than one device with
     the same vendor and product identifiers are present.
 
+    In addition, if the moniker ends with the symbol "!", the device will be used in "forced" mode:
+    the first USB interface of the device will be used, regardless of the interface class/subclass.
+    This may be useful for some devices that use a custom class/subclass but may nonetheless work as-is.
+
     Examples:
     0 --> the first BT USB dongle
     04b4:f901 --> the BT USB dongle with vendor=04b4 and product=f901
     04b4:f901#2 --> the third USB device with vendor=04b4 and product=f901
     04b4:f901/00E04C239987 --> the BT USB dongle with vendor=04b4 and product=f901 and serial number 00E04C239987
+    usb:0B05:17CB! --> the BT USB dongle vendor=0B05 and product=17CB, in "forced" mode.
     '''
 
     USB_RECIPIENT_DEVICE                             = 0x00
     USB_REQUEST_TYPE_CLASS                           = 0x01 << 5
+    USB_DEVICE_CLASS_DEVICE                          = 0x00
     USB_DEVICE_CLASS_WIRELESS_CONTROLLER             = 0xE0
     USB_DEVICE_SUBCLASS_RF_CONTROLLER                = 0x01
     USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER = 0x01
@@ -63,6 +69,12 @@ async def open_usb_transport(spec):
     USB_ENDPOINT_TRANSFER_TYPE_INTERRUPT             = 0x03
     USB_ENDPOINT_IN                                  = 0x80
 
+    USB_BT_HCI_CLASS_TUPLE = (
+        USB_DEVICE_CLASS_WIRELESS_CONTROLLER,
+        USB_DEVICE_SUBCLASS_RF_CONTROLLER,
+        USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER
+    )
+
     READ_SIZE = 1024
 
     class UsbPacketSink:
@@ -280,6 +292,13 @@ async def open_usb_transport(spec):
     context.open()
     try:
         found = None
+
+        if spec.endswith('!'):
+            spec = spec[:-1]
+            forced_mode = True
+        else:
+            forced_mode = False
+
         if ':' in spec:
             vendor_id, product_id = spec.split(':')
             serial_number = None
@@ -291,10 +310,14 @@ async def open_usb_transport(spec):
                 device_index = int(device_index_str)
 
             for device in context.getDeviceIterator(skip_on_error=True):
+                try:
+                    device_serial_number = device.getSerialNumber()
+                except usb1.USBError:
+                    device_serial_number = None
                 if (
                     device.getVendorID() == int(vendor_id, 16) and
                     device.getProductID() == int(product_id, 16) and
-                    (serial_number is None or device.getSerialNumber() == serial_number)
+                    (serial_number is None or serial_number == device_serial_number)
                 ):
                     if device_index == 0:
                         found = device
@@ -302,13 +325,27 @@ async def open_usb_transport(spec):
                     device_index -= 1
                 device.close()
         else:
+            # Look for a compatible device by index
+            def device_is_bluetooth_hci(device):
+                # Check if the device class indicates a match
+                if (device.getDeviceClass(), device.getDeviceSubClass(), device.getDeviceProtocol()) == \
+                        USB_BT_HCI_CLASS_TUPLE:
+                    return True
+
+                # If the device class is 'Device', look for a matching interface
+                if device.getDeviceClass() == USB_DEVICE_CLASS_DEVICE:
+                    for configuration in device:
+                        for interface in configuration:
+                            for setting in interface:
+                                if (setting.getClass(), setting.getSubClass(), setting.getProtocol()) == \
+                                        USB_BT_HCI_CLASS_TUPLE:
+                                    return True
+
+                return False
+
             device_index = int(spec)
             for device in context.getDeviceIterator(skip_on_error=True):
-                if (
+                if device_is_bluetooth_hci(device):
-                    device.getDeviceClass()    == USB_DEVICE_CLASS_WIRELESS_CONTROLLER and
-                    device.getDeviceSubClass() == USB_DEVICE_SUBCLASS_RF_CONTROLLER and
-                    device.getDeviceProtocol() == USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER
-                ):
                     if device_index == 0:
                         found = device
                         break
@@ -329,9 +366,8 @@ async def open_usb_transport(spec):
                     setting = None
                     for setting in interface:
                         if (
-                            setting.getClass() != USB_DEVICE_CLASS_WIRELESS_CONTROLLER or
+                            not forced_mode and
-                            setting.getSubClass() != USB_DEVICE_SUBCLASS_RF_CONTROLLER or
+                            (setting.getClass(), setting.getSubClass(), setting.getProtocol()) != USB_BT_HCI_CLASS_TUPLE
-                            setting.getProtocol() != USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER
                         ):
                             continue
 

docs/mkdocs/mkdocs.yml

@@ -45,6 +45,10 @@ nav:
     - HCI Bridge: apps_and_tools/hci_bridge.md
     - Golden Gate Bridge: apps_and_tools/gg_bridge.md
     - Show: apps_and_tools/show.md
+    - GATT Dump: apps_and_tools/gatt_dump.md
+    - Pair: apps_and_tools/pair.md
+    - Unbond: apps_and_tools/unbond.md
+    - USB Probe: apps_and_tools/usb_probe.md
   - Hardware:
     - Overview: hardware/index.md
   - Platforms:

docs/mkdocs/requirements.txt

@@ -1,6 +1,6 @@
 # This requirements file is for python3
-mkdocs == 1.2.3
+mkdocs == 1.4.0
-mkdocs-material == 7.1.7
+mkdocs-material == 8.5.6
-mkdocs-material-extensions == 1.0.1
+mkdocs-material-extensions == 1.0.3
-pymdown-extensions == 8.2
+pymdown-extensions == 9.6
-mkdocstrings == 0.15.1
+mkdocstrings-python == 0.7.1

docs/mkdocs/src/apps_and_tools/usb_probe.md

@@ -13,17 +13,29 @@ type of device (there's no way to tell).
 
 ## Usage
 
-This command line tool takes no arguments.
+This command line tool may be invoked with no arguments, or with `--verbose`
+for extra details.
 When installed from PyPI, run as
 ```
 $ bumble-usb-probe
 ```
 
+or, for extra details, with the `--verbose` argument
+```
+$ bumble-usb-probe --v
+```
+
 When running from the source distribution:
 ```
 $ python3 apps/usb-probe.py
 ```
 
+or 
+
+```
+$ python3 apps/usb-probe.py --verbose
+```
+
 !!! example
     ```
     $ python3 apps/usb_probe.py 

docs/mkdocs/src/platforms/linux.md

@@ -1,48 +1,86 @@
 :material-linux: LINUX PLATFORM
 ===============================
 
-In addition to all the standard functionality available from the project by running the python tools and/or writing your own apps by leveraging the API, it is also possible on Linux hosts to interface the Bumble stack with the native BlueZ stack, and with Bluetooth controllers.
+Using Bumble With Physical Bluetooth Controllers
+------------------------------------------------
 
-Using Bumble With BlueZ
+A Bumble application can interface with a local Bluetooth controller on a Linux host.
------------------------
+The 3 main types of physical Bluetooth controllers are:
 
-A Bumble virtual controller can be attached to the BlueZ stack.
+  * Bluetooth USB Dongle
-Attaching a controller to BlueZ can be done by either simulating a UART HCI interface, or by using the VHCI driver interface if available.
+  * HCI over  UART (via a serial port)
-In both cases, the controller can run locally on the Linux host, or remotely on a different host, with a bridge between the remote controller and the local BlueZ host, which may be useful when the BlueZ stack is running on an embedded system, or a host on which running the Bumble controller is not convenient.
+  * Kernel-managed Bluetooth HCI (HCI Sockets)
 
-### Using VHCI
+!!! tip "Conflicts with the kernel and BlueZ"
+    If your use a USB dongle that is recognized by your kernel as a supported Bluetooth device, it is
+    likely that the kernel driver will claim that USB device and attach it to the BlueZ stack. 
+    If you want to claim ownership of it to use with Bumble, you will need to set the state of the corresponding HCI interface as `DOWN`. 
+    HCI interfaces are numbered, starting from 0 (i.e `hci0`, `hci1`, ...).
 
-With the [VHCI transport](../transports/vhci.md) you can attach a Bumble virtual controller to the BlueZ stack. Once attached, the controller will appear just like any other controller, and thus can be used with the standard BlueZ tools.
+    For example, to bring `hci0` down:
-
-!!! example "Attaching a virtual controller"
-    With the example app `run_controller.py`:
     ```
-    PYTHONPATH=. python3 examples/run_controller.py F6:F7:F8:F9:FA:FB examples/device1.json vhci
+    $ sudo hciconfig hci0 down
-    ```
-    
-    You should see a 'Virtual Bus' controller. For example:
-    ```
-    $ hciconfig
-    hci0:	Type: Primary  Bus: Virtual
-        BD Address: F6:F7:F8:F9:FA:FB  ACL MTU: 27:64  SCO MTU: 0:0
-        UP RUNNING 
-        RX bytes:0 acl:0 sco:0 events:43 errors:0
-        TX bytes:274 acl:0 sco:0 commands:43 errors:0
     ```
 
-    And scanning for devices should show the virtual 'Bumble' device that's running as part of the `run_controller.py` example app:
+    You can use the `hciconfig` command with no arguments to get a list of HCI interfaces seen by
+    the kernel.
+
+    Also, if `bluetoothd` is running on your system, it will likely re-claim the interface after you
+    close it, so you may need to bring the interface back `UP` before using it again, or to disable
+    `bluetoothd` altogether (see the section further below about BlueZ and `bluetoothd`).
+
+### Using a USB Dongle
+
+See the [USB Transport page](../transports/usb.md) for general information on how to use HCI USB controllers.
+
+!!! tip "USB Permissions"
+    By default, when running as a regular user, you won't have the permission to use
+    arbitrary USB devices.
+    You can change the permissions for a specific USB device based on its bus number and 
+    device number (you can use `lsusb` to find the Bus and Device numbers for your Bluetooth
+    dongle).
+
+    Example:
     ```
-    pi@raspberrypi:~ $ sudo hcitool -i hci2 lescan
+    $ sudo chmod o+w /dev/bus/usb/001/004
-    LE Scan ...
-    F0:F1:F2:F3:F4:F5 Bumble
     ```
+    This will change the permissions for Device 4 on Bus 1.
+
+    Note that the USB Bus number and Device number may change depending on where you plug the USB
+    dongle and what other USB devices and hubs are also plugged in.
+
+    If you need to make the permission changes permanent across reboots, you can create a `udev`
+    rule for your specific Bluetooth dongle. Visit [this Arch Linux Wiki page](https://wiki.archlinux.org/title/udev) for a
+    good overview of how you may do that.
+
+### Using HCI over UART
+
+See the [Serial Transport page](../transports/serial.md) for general information on how to use HCI over a UART (serial port).
 
 ### Using HCI Sockets
 
 HCI sockets provide a way to send/receive HCI packets to/from a Bluetooth controller managed by the kernel.
-The HCI device referenced by an `hci-socket` transport (`hciX`, where `X` is an integer, with `hci0` being the first controller device, and so on) must be in the `DOWN` state before it can be opened as a transport.
+See the [HCI Socket Transport page](../transports/hci_socket.md) for details on the `hci-socket` tansport syntax.
-You can bring a HCI controller `UP` or `DOWN` with `hciconfig`.
 
+The HCI device referenced by an `hci-socket` transport (`hci<X>`, where `<X>` is an integer, with `hci0` being the first controller device, and so on) must be in the `DOWN` state before it can be opened as a transport.
+You can bring a HCI controller `UP` or `DOWN` with `hciconfig hci<X> up` and `hciconfig hci<X> up`.
+
+!!! tip "HCI Socket Permissions"
+    By default, when running as a regular user, you won't have the permission to use
+    an HCI socket to a Bluetooth controller (you may see an exception like `PermissionError: [Errno 1] Operation not permitted`).
+
+    If you want to run without using `sudo`, you need to manage the capabilities by adding the appropriate entries in `/etc/security/capability.conf` to grant a user or group the `cap_net_admin` capability.  
+    See [this manpage](https://manpages.ubuntu.com/manpages/bionic/man5/capability.conf.5.html) for details.
+    
+    Alternatively, if you are just experimenting temporarily, the `capsh` command may be useful in order
+    to execute a single command with enhanced permissions, as in this example:
+
+
+    ```
+    $ sudo capsh --caps="cap_net_admin+eip cap_setpcap,cap_setuid,cap_setgid+ep" --keep=1 --user=$USER --addamb=cap_net_admin  -- -c "<path/to/executable> <executable-args>"
+    ```
+    Where `<path/to/executable>` is the path to your `python3` executable or to one of the Bumble bundled command-line applications.
+    
 !!! tip "List all available controllers"
     The command
     ```
@@ -72,29 +110,16 @@ You can bring a HCI controller `UP` or `DOWN` with `hciconfig`.
     ```
     $ hciconfig hci0 down
     ``` 
-    (or `hciX` with `X` being the index of the controller device you want to use), but a simpler solution is to just stop the `bluetoothd` daemon, with a command like:
+    (or `hci<X>` with `<X>` being the index of the controller device you want to use), but a simpler solution is to just stop the `bluetoothd` daemon, with a command like:
     ```
     $ sudo systemctl stop bluetooth.service
     ```
     You can always re-start the daemon with
     ```
     $ sudo systemctl start bluetooth.service
-    ```
 
-### Using a Simulated UART HCI
+Bumble on the Raspberry Pi
-
+--------------------------
-### Bridge to a Remote Controller
-
-
-Using Bumble With Bluetooth Controllers
----------------------------------------
-
-A Bumble application can interface with a local Bluetooth controller.
-If your Bluetooth controller is a standard HCI USB controller, see the [USB Transport page](../transports/usb.md) for details on how to use HCI USB controllers.
-If your Bluetooth controller is a standard HCI UART controller, see the [Serial Transport page](../transports/serial.md).
-Alternatively, a Bumble Host object can communicate with one of the platform's controllers via an HCI Socket.
-
-`<details to be filled in>`
 
 ### Raspberry Pi 4 :fontawesome-brands-raspberry-pi:
 
@@ -102,9 +127,10 @@ You can use the Bluetooth controller either via the kernel, or directly to the d
 
 #### Via The Kernel
 
-Use an HCI Socket transport
+Use an HCI Socket transport (see section above)
 
 #### Directly
+
 In order to use the Bluetooth controller directly on a Raspberry Pi 4 board, you need to ensure that it isn't being used by the BlueZ stack (which it probably is by default).
 
 ```
@@ -136,3 +162,47 @@ should detach the controller from the stack, after which you can use the HCI UAR
     python3 run_scanner.py serial:/dev/serial1,3000000
     ```
 
+
+Using Bumble With BlueZ
+-----------------------
+
+In addition to all the standard functionality available from the project by running the python tools and/or writing your own apps by leveraging the API, it is also possible on Linux hosts to interface the Bumble stack with the native BlueZ stack, and with Bluetooth controllers.
+
+A Bumble virtual controller can be attached to the BlueZ stack.
+Attaching a controller to BlueZ can be done by either simulating a UART HCI interface, or by using the VHCI driver interface if available.
+In both cases, the controller can run locally on the Linux host, or remotely on a different host, with a bridge between the remote controller and the local BlueZ host, which may be useful when the BlueZ stack is running on an embedded system, or a host on which running the Bumble controller is not convenient.
+
+### Using VHCI
+
+With the [VHCI transport](../transports/vhci.md) you can attach a Bumble virtual controller to the BlueZ stack. Once attached, the controller will appear just like any other controller, and thus can be used with the standard BlueZ tools.
+
+!!! example "Attaching a virtual controller"
+    With the example app `run_controller.py`:
+    ```
+    python3 examples/run_controller.py F6:F7:F8:F9:FA:FB examples/device1.json vhci
+    ```
+    
+    You should see a 'Virtual Bus' controller. For example:
+    ```
+    $ hciconfig
+    hci0:	Type: Primary  Bus: Virtual
+        BD Address: F6:F7:F8:F9:FA:FB  ACL MTU: 27:64  SCO MTU: 0:0
+        UP RUNNING 
+        RX bytes:0 acl:0 sco:0 events:43 errors:0
+        TX bytes:274 acl:0 sco:0 commands:43 errors:0
+    ```
+
+    And scanning for devices should show the virtual 'Bumble' device that's running as part of the `run_controller.py` example app:
+    ```
+    pi@raspberrypi:~ $ sudo hcitool -i hci2 lescan
+    LE Scan ...
+    F0:F1:F2:F3:F4:F5 Bumble
+    ```
+
+    ```
+
+### Using a Simulated UART HCI
+
+### Bridge to a Remote Controller
+
+

docs/mkdocs/src/transports/usb.md

@@ -5,6 +5,7 @@ The USB transport interfaces with a local Bluetooth USB dongle.
 
 ## Moniker
 The moniker for a USB transport is either:
+
   * `usb:<index>`
   * `usb:<vendor>:<product>`
   * `usb:<vendor>:<product>/<serial-number>`
@@ -16,6 +17,10 @@ In the `usb:<vendor>:<product>#<index>` form, matching devices are the ones with
 
 `<vendor>` and `<product>` are a vendor ID and product ID in hexadecimal.
 
+In addition, if the moniker ends with the symbol "!", the device will be used in "forced" mode:
+the first USB interface of the device will be used, regardless of the interface class/subclass.
+This may be useful for some devices that use a custom class/subclass but may nonetheless work as-is.
+
 !!! examples
     `usb:04b4:f901`  
     The USB dongle with `<vendor>` equal to `04b4` and `<product>` equal to `f901`
@@ -29,6 +34,10 @@ In the `usb:<vendor>:<product>#<index>` form, matching devices are the ones with
     `usb:04b4:f901/#1`
     The second USB dongle with `<vendor>` equal to `04b4` and `<product>` equal to `f901`
 
+    `usb:0B05:17CB!`
+    The BT USB dongle vendor=0B05 and product=17CB, in "forced" mode.
+
+
 ## Alternative
 The library includes two different implementations of the USB transport, implemented using different python bindings for `libusb`.
 Using the transport prefix `pyusb:` instead of `usb:` selects the implementation based on  [PyUSB](https://pypi.org/project/pyusb/), using the synchronous API of `libusb`, whereas the default implementation is based on [libusb1](https://pypi.org/project/libusb1/), using the asynchronous API of `libusb`. In order to use the alternative PyUSB-based implementation, you need to ensure that you have installed that python module, as it isn't installed by default as a dependency of Bumble.

setup.cfg

@@ -67,6 +67,6 @@ development =
     invoke >= 1.4
     nox >= 2022
 documentation =
-    mkdocs >= 1.2.3
+    mkdocs >= 1.4.0
-    mkdocs-material >= 8.1.9
+    mkdocs-material >= 8.5.6
     mkdocstrings[python] >= 0.19.0