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marmarek/gadget-control.py

Last active February 9, 2022 22:56
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gadget-control.py
#!/usr/bin/python3
import argparse
import os
import os.path
import pathlib
import struct
import sys
import fileinput
class Gadget:
def __init__(self, storage_path=None, cdrom=False, hid=True):
self.gadget_configfs_root = pathlib.Path("/sys/kernel/config/usb_gadget/kbd")
self.udc = os.listdir('/sys/class/udc')[0]
self.mouse_dev = None
self.keyboard_dev = None
self.storage_path = storage_path
self.storage_cdrom = cdrom
self.hid = hid
def set_sysfs_attr(self, name, value):
path = self.gadget_configfs_root / name
os.makedirs(os.path.dirname(path), exist_ok=True)
if isinstance(value, str):
value = value.encode()
if isinstance(value, int):
value = str(value).encode()
with open(path, 'wb') as f:
f.write(value)
def create_gadget(self):
self.set_sysfs_attr('bcdUSB', '0x0200') # USB 2.0
self.set_sysfs_attr('bDeviceClass', '0x00') # specified in interface
self.set_sysfs_attr('bDeviceSubClass', '0x00') # specified in interface
self.set_sysfs_attr('bcdDevice', '0x0100') # v1.0.0
self.set_sysfs_attr('bDeviceProtocol', '0x00') # specified in interface
self.set_sysfs_attr('idVendor', '0x1d6b') # Linux Foundation
self.set_sysfs_attr('idProduct', '0x0104') # Multifunction composite gadget
self.set_sysfs_attr('strings/0x409/manufacturer', 'marmarek')
self.set_sysfs_attr('strings/0x409/product', 'RPi4 USB Gadget')
self.set_sysfs_attr('strings/0x409/serialnumber', '0123456789abcdef')
self.set_sysfs_attr('configs/c.1/bmAttributes', '0x80') # Bus powered
self.set_sysfs_attr('configs/c.1/MaxPower', '250')
self.set_sysfs_attr('configs/c.1/strings/0x409/configuration', 'c1')
if self.hid:
self._create_keyboard_function()
self._create_mouse_function()
if self.storage_path:
self._create_storage_function()
def _create_keyboard_function(self):
p = 'functions/hid.usb0/'
self.set_sysfs_attr(p + 'protocol', '1') # Keyboard
self.set_sysfs_attr(p + 'subclass', '1') # boot interface subclass
self.set_sysfs_attr(p + 'report_length', '8')
report_descriptor = [
0x05, 0x01, # USAGE_PAGE (Generic Desktop)
0x09, 0x06, # USAGE (Keyboard)
0xa1, 0x01, # COLLECTION (Application)
0x05, 0x07, # USAGE_PAGE (Keyboard)
0x19, 0xe0, # USAGE_MINIMUM (Keyboard LeftControl)
0x29, 0xe7, # USAGE_MAXIMUM (Keyboard Right GUI)
0x15, 0x00, # LOGICAL_MINIMUM (0)
0x25, 0x01, # LOGICAL_MAXIMUM (1)
0x75, 0x01, # REPORT_SIZE (1)
0x95, 0x08, # REPORT_COUNT (8)
0x81, 0x02, # INPUT (Data,Var,Abs)
0x95, 0x01, # REPORT_COUNT (1)
0x75, 0x08, # REPORT_SIZE (8)
0x81, 0x03, # INPUT (Cnst,Var,Abs)
0x95, 0x05, # REPORT_COUNT (5)
0x75, 0x01, # REPORT_SIZE (1)
0x05, 0x08, # USAGE_PAGE (LEDs)
0x19, 0x01, # USAGE_MINIMUM (Num Lock)
0x29, 0x05, # USAGE_MAXIMUM (Kana)
0x91, 0x02, # OUTPUT (Data,Var,Abs)
0x95, 0x01, # REPORT_COUNT (1)
0x75, 0x03, # REPORT_SIZE (3)
0x91, 0x03, # OUTPUT (Cnst,Var,Abs)
0x95, 0x06, # REPORT_COUNT (6)
0x75, 0x08, # REPORT_SIZE (8)
0x15, 0x00, # LOGICAL_MINIMUM (0)
0x25, 0x65, # LOGICAL_MAXIMUM (101)
0x05, 0x07, # USAGE_PAGE (Keyboard)
0x19, 0x00, # USAGE_MINIMUM (Reserved)
0x29, 0x65, # USAGE_MAXIMUM (Keyboard Application)
0x81, 0x00, # INPUT (Data,Ary,Abs)
0xc0 # END_COLLECTION
]
self.set_sysfs_attr(p + 'report_desc', bytes(report_descriptor))
os.symlink(self.gadget_configfs_root / 'functions/hid.usb0',
os.path.join(self.gadget_configfs_root, 'configs/c.1/hid.usb0'))
def _create_mouse_function(self):
p = 'functions/hid.usb1/'
self.set_sysfs_attr(p + 'protocol', '0') # tablet
self.set_sysfs_attr(p + 'subclass', '0') # unspecified
self.set_sysfs_attr(p + 'report_length', '6')
# this mouse reports ABSOLUTE position, not relative!
report_descriptor = [
0x05, 0x01, # Usage Page (Generic Desktop Ctrls)
0x09, 0x02, # Usage (Mouse)
0xA1, 0x01, # Collection (Application)
0x85, 0x01, # Report ID (1)
0x09, 0x01, # Usage (Pointer)
0xA1, 0x00, # Collection (Physical)
0x05, 0x09, # Usage Page (Button)
0x19, 0x01, # Usage Minimum (0x01)
0x29, 0x03, # Usage Maximum (0x03)
0x15, 0x00, # Logical Minimum (0)
0x25, 0x01, # Logical Maximum (1)
0x95, 0x03, # Report Count (3)
0x75, 0x01, # Report Size (1)
0x81, 0x02, # Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0x95, 0x01, # Report Count (1)
0x75, 0x05, # Report Size (5)
0x81, 0x03, # Input (Const,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0x05, 0x01, # Usage Page (Generic Desktop Ctrls)
0x09, 0x30, # Usage (X)
0x09, 0x31, # Usage (Y)
0x16, 0x01, 0x80, # Logical Minimum (-32767)
0x26, 0xFF, 0x7F, # Logical Maximum (32767)
0x75, 0x10, # Report Size (16)
0x95, 0x02, # Report Count (2)
0x81, 0x06, # Input (Data,Var,Rel,No Wrap,Linear,Preferred State,No Null Position)
0xC0, # End Collection
0xC0, # End Collection
0x05, 0x0d, # Usage Page (Digitizer)
0x09, 0x01, # Usage (Digitizer)
0xA1, 0x01, # Collection (Application)
0x85, 0x02, # Report ID (2)
0x05, 0x0d, # Usage Page (Digitizer)
0x09, 0x20, # Usage (Stylus)
0xA1, 0x00, # Collection (Physical)
0x09, 0x32, # Usage (In Range)
0x09, 0x42, # Usage (Tip Switch)
0x09, 0x44, # Usage (Barrel Switch)
0x15, 0x00, # Logical Minimum (0)
0x25, 0x01, # Logical Maximum (1)
0x95, 0x03, # Report Count (3)
0x75, 0x01, # Report Size (1)
0x81, 0x02, # Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0x95, 0x05, # Report Count (5)
0x75, 0x01, # Report Size (1)
0x81, 0x03, # Input (Const,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0x05, 0x01, # Usage Page (Generic Desktop Ctrls)
0x55, 0x0E, # UNIT_EXPONENT (-2) //10^(-2)
0x65, 0x13, # UNIT (Inches, English Linear) //But exponent -2, so Physical Maximum is in 10’s of mils.
0x09, 0x30, # Usage (X)
0x15, 0x00, # Logical Minimum (0)
0x26, 0x00, 0x04, # Logical Maximum (1024)
0x35, 0x00, # Physical Minimum (0)
0x46, 0x00, 0x04, # Physical Maximum (1024)
0x75, 0x10, # Report Size (16)
0x95, 0x01, # Report Count (1)
0x81, 0x02, # Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0x09, 0x31, # Usage (Y)
0x26, 0x00, 0x03, # Logical Maximum (768)
0x46, 0x00, 0x03, # Physical Maximum (768)
0x81, 0x02, # Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0xC0, # End Collection
0xC0, # End Collection
]
self.set_sysfs_attr(p + 'report_desc', bytes(report_descriptor))
os.symlink(self.gadget_configfs_root / 'functions/hid.usb1',
self.gadget_configfs_root / 'configs/c.1/hid.usb1')
def _create_storage_function(self):
p = 'functions/mass_storage.usb2/lun.0/'
self.set_sysfs_attr(p + 'cdrom', 'Y' if self.storage_cdrom else 'N') # is cdrom
self.set_sysfs_attr(p + 'file', self.storage_path) # backing file
self.set_sysfs_attr(p + 'removable', '1')
os.symlink(self.gadget_configfs_root / 'functions/mass_storage.usb2',
self.gadget_configfs_root / 'configs/c.1/mass_storage.usb2')
def _get_gadget_dev(self, func):
with open(self.gadget_configfs_root / (func + '/dev'), 'r') as f:
devnum = f.read()
return '/dev/' + os.path.basename(os.readlink('/sys/dev/char/' + devnum.strip()))
def enable(self):
with open(self.gadget_configfs_root / 'UDC', 'w') as f:
f.write(self.udc)
if self.hid:
self.keyboard_dev = open(self._get_gadget_dev('functions/hid.usb0'), 'wb', buffering=0)
self.mouse_dev = open(self._get_gadget_dev('functions/hid.usb1'), 'wb', buffering=0)
def disable(self):
if self.keyboard_dev:
self.keyboard_dev.close()
self.keyboard_dev = None
if self.mouse_dev:
self.mouse_dev.close()
self.mouse_dev = None
with open(os.path.join(self.gadget_configfs_root, 'UDC'), 'w'):
pass
def cleanup(self):
for d in os.listdir(self.gadget_configfs_root / 'configs/c.1'):
if '.usb' in d:
os.unlink(self.gadget_configfs_root / 'configs/c.1' / d)
for (dirpath, dirs, _files) in os.walk(self.gadget_configfs_root, topdown=False):
for d in dirs:
if d in ('strings', 'os_desc', 'configs', 'functions', 'lun.0'):
# Linux doesn't allow to remove this one
continue
os.rmdir(os.path.join(dirpath, d))
os.rmdir(self.gadget_configfs_root)
def write_mouse_move_report(self, x, y, wheel=0):
# 2 - report id - stylus
# 0x01 - in range, but not touching
report = struct.pack('<bBhh', 2, 0x01, x, y)
self.mouse_dev.write(report)
def write_mouse_btn_report(self, buttons):
# 1 - report id - buttons
report = struct.pack('<bBxxxx', 1, buttons)
self.mouse_dev.write(report)
def write_keyboard_report(self, modifiers, key):
# TODO: more keys?
report = struct.pack('BxxBxxxx', modifiers, key)
self.keyboard_dev.write(report)
self.keyboard_dev.write(b'\0' * 8)
def __enter__(self):
if os.path.exists(self.gadget_configfs_root):
# previous instance didn't cleaned up
self.disable()
self.cleanup()
self.create_gadget()
self.enable()
return self
def __exit__(self, exc_type, exc_value, exc_traceback):
self.disable()
self.cleanup()
# based on Universal Serial Bus HID Usage Tables
keycodes = {
# key: (mods, keycode)
'a': (0, 0x04), 'A': (2, 0x04),
'b': (0, 0x05), 'B': (2, 0x05),
'c': (0, 0x06), 'C': (2, 0x06),
'd': (0, 0x07), 'D': (2, 0x07),
'e': (0, 0x08), 'E': (2, 0x08),
'f': (0, 0x09), 'F': (2, 0x09),
'g': (0, 0x0A), 'G': (2, 0x0A),
'h': (0, 0x0B), 'H': (2, 0x0B),
'i': (0, 0x0C), 'I': (2, 0x0C),
'j': (0, 0x0D), 'J': (2, 0x0D),
'k': (0, 0x0E), 'K': (2, 0x0E),
'l': (0, 0x0F), 'L': (2, 0x0F),
'm': (0, 0x10), 'M': (2, 0x10),
'n': (0, 0x11), 'N': (2, 0x11),
'o': (0, 0x12), 'O': (2, 0x12),
'p': (0, 0x13), 'P': (2, 0x13),
'q': (0, 0x14), 'Q': (2, 0x14),
'r': (0, 0x15), 'R': (2, 0x15),
's': (0, 0x16), 'S': (2, 0x16),
't': (0, 0x17), 'T': (2, 0x17),
'u': (0, 0x18), 'U': (2, 0x18),
'v': (0, 0x19), 'V': (2, 0x19),
'w': (0, 0x1A), 'W': (2, 0x1A),
'x': (0, 0x1B), 'X': (2, 0x1B),
'y': (0, 0x1C), 'Y': (2, 0x1C),
'z': (0, 0x1D), 'Z': (2, 0x1D),
'1': (0, 0x1E), '!': (2, 0x1E),
'2': (0, 0x1F), '@': (2, 0x1F),
'3': (0, 0x20), '#': (2, 0x20),
'4': (0, 0x21), '$': (2, 0x21),
'5': (0, 0x22), '%': (2, 0x22),
'6': (0, 0x23), '^': (2, 0x23),
'7': (0, 0x24), '&': (2, 0x24),
'8': (0, 0x25), '*': (2, 0x25),
'9': (0, 0x26), '(': (2, 0x26),
'0': (0, 0x27), ')': (2, 0x27),
'ret': (0, 0x28),
'esc': (0, 0x29),
'backspace': (0, 0x2A),
'tab': (0, 0x2B),
'space': (0, 0x2C),
'-': (0, 0x2D), '_': (2, 0x2D),
'minus': (0, 0x2D),
'=': (0, 0x2E), '+': (2, 0x2E),
'[': (0, 0x2F), '{': (2, 0x2F),
']': (0, 0x30), '}': (2, 0x30),
'\\': (0, 0x31), '|': (2, 0x31),
#'#': (0, 0x32), '~': (2, 0x32),
';': (0, 0x33), ':': (2, 0x33),
'\'': (0, 0x34), '"': (2, 0x34),
'`': (0, 0x35), '~': (2, 0x35),
',': (0, 0x36), '<': (2, 0x36),
'.': (0, 0x37), '>': (2, 0x37),
'/': (0, 0x38), '?': (2, 0x38),
#'caps lock': (0, 0x39),
'f1': (0, 0x3A),
'f2': (0, 0x3B),
'f3': (0, 0x3C),
'f4': (0, 0x3D),
'f5': (0, 0x3E),
'f6': (0, 0x3F),
'f7': (0, 0x40),
'f8': (0, 0x41),
'f9': (0, 0x42),
'f10': (0, 0x43),
'f11': (0, 0x44),
'f12': (0, 0x45),
'printscreen': (0, 0x46),
'scroll': (0, 0x47),
'pause': (0, 0x48),
'insert': (0, 0x49),
'home': (0, 0x4A),
'pageup': (0, 0x4B),
'delete': (0, 0x4C),
'end': (0, 0x4D),
'pagedown': (0, 0x4E),
'right': (0, 0x4F),
'left': (0, 0x50),
'down': (0, 0x51),
'up': (0, 0x52),
'ctrl': (1, 0x0),
'shift': (2, 0x0),
'alt': (4, 0x0),
'meta': (8, 0x0),
'rctrl': (16, 0x0),
'rshift': (32, 0x0),
'ralt': (64, 0x0),
'rmeta': (128, 0x0),
}
def parse_and_send_cmd(gadget, line):
if line.startswith('mouse_'):
cmd, param = line.split(' ', 1)
if cmd == 'mouse_move':
x, y = [int(p) for p in param.split(' ')]
#x, y = (32767/1024*x), (32767/768*y)
gadget.write_mouse_move_report(int(x), int(y))
elif cmd == 'mouse_button':
param = int(param)
gadget.write_mouse_btn_report(param)
else:
print("Unknown command: {}".format(cmd), file=sys.stderr)
return
key = line
mods = 0
while True:
if key.startswith('ctrl-'):
mods |= 0x01
key = key[len('ctrl-'):]
elif key.startswith('shift-'):
mods |= 0x02
key = key[len('shift-'):]
elif key.startswith('alt-'):
mods |= 0x04
key = key[len('alt-'):]
else:
break
if key not in keycodes:
print("Unknown key: {}".format(key))
return
extra_mods, keycode = keycodes[key]
mods |= extra_mods
gadget.write_keyboard_report(mods, keycode)
def main():
parser = argparse.ArgumentParser()
parser.add_argument('--storage', default=None, action='store')
parser.add_argument('--is-cdrom', default=False, action='store_true')
parser.add_argument('--storage-only', default=False, action='store_true')
args = parser.parse_args()
with Gadget(storage_path=args.storage, cdrom=args.is_cdrom, hid=not args.storage_only) as gadget:
for line in fileinput.input(files=[]):
parse_and_send_cmd(gadget, line.strip())
if __name__ == '__main__':
main()
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