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# ========================================================================== #
# #
# KVMD - The main Pi-KVM daemon. #
# #
# Copyright (C) 2018 Maxim Devaev <[email protected]> #
# #
# This program is free software: you can redistribute it and/or modify #
# it under the terms of the GNU General Public License as published by #
# the Free Software Foundation, either version 3 of the License, or #
# (at your option) any later version. #
# #
# This program is distributed in the hope that it will be useful, #
# but WITHOUT ANY WARRANTY; without even the implied warranty of #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
# GNU General Public License for more details. #
# #
# You should have received a copy of the GNU General Public License #
# along with this program. If not, see <https://www.gnu.org/licenses/>. #
# #
# ========================================================================== #
import os
import signal
import errno
import argparse
import psutil
# =====
def _set_param(gadget: str, param: str, value: str) -> None:
param_path = os.path.join(
"/sys/kernel/config/usb_gadget",
gadget,
"functions/mass_storage.usb0/lun.0",
param,
)
try:
with open(param_path, "w") as param_file:
param_file.write(value + "\n")
except OSError as err:
if err.errno == errno.EBUSY:
raise SystemExit(f"Can't change {param!r} value because device is locked: {err}")
raise
def _reset_msd() -> None:
# https://github.com/torvalds/linux/blob/3039fad/drivers/usb/gadget/function/f_mass_storage.c#L2924
found = False
for proc in psutil.process_iter():
attrs = proc.as_dict(attrs=["name", "exe", "pid"])
if attrs.get("name") == "file-storage" and not attrs.get("exe"):
try:
proc.send_signal(signal.SIGUSR1)
found = True
except Exception as err:
SystemExit(f"Can't send SIGUSR1 to MSD kernel thread with pid={attrs['pid']}: {err}")
if not found:
raise SystemExit("Can't find MSD kernel thread")
# =====
def main() -> None:
parser = argparse.ArgumentParser(description="KVMD OTG MSD Helper")
parser.add_argument("--reset", action="store_true", help="Send SIGUSR1 to MSD kernel thread")
parser.add_argument("--set-cdrom", dest="cdrom", default=None, choices=["0", "1"], help="Set CD-ROM flag")
parser.add_argument("--set-ro", dest="ro", default=None, choices=["0", "1"], help="Set read-only flag")
parser.add_argument("--set-image", dest="image_path", default=None, help="Change image path (or eject for the empty)")
parser.add_argument("--gadget", default="kvmd", help="USB gadget name")
options = parser.parse_args()
if options.reset:
_reset_msd()
if options.cdrom is not None:
_set_param(options.gadget, "cdrom", options.cdrom)
if options.ro is not None:
_set_param(options.gadget, "ro", options.ro)
if options.image_path is not None:
_set_param(options.gadget, "file", options.image_path)
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