One-KVM/kvmd/apps/otgmsd/__init__.py
2019-10-19 19:37:32 +03:00

128 lines
4.9 KiB
Python

# ========================================================================== #
# #
# KVMD - The main Pi-KVM daemon. #
# #
# Copyright (C) 2018 Maxim Devaev <mdevaev@gmail.com> #
# #
# 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
from typing import List
from typing import Optional
import psutil
import yaml
from ...validators.kvm import valid_msd_image_name
from .. import init
# =====
def _make_param_path(gadget: str, param: str) -> str:
return os.path.join(
"/sys/kernel/config/usb_gadget",
gadget,
"functions/mass_storage.usb0/lun.0",
param,
)
def _get_param(gadget: str, param: str) -> str:
with open(_make_param_path(gadget, param)) as param_file:
return param_file.read().strip()
def _set_param(gadget: str, param: str, value: str) -> None:
try:
with open(_make_param_path(gadget, param), "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:
raise 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(argv: Optional[List[str]]=None) -> None:
(parent_parser, argv, config) = init(
add_help=False,
argv=argv,
load_msd=True,
)
parser = argparse.ArgumentParser(
prog="kvmd-otg-msd",
description="KVMD OTG MSD Helper",
parents=[parent_parser],
)
parser.add_argument("--reset", action="store_true", help="Send SIGUSR1 to MSD kernel thread")
parser.add_argument("--set-cdrom", default=None, choices=["0", "1"], help="Set CD-ROM flag")
parser.add_argument("--set-ro", default=None, choices=["0", "1"], help="Set read-only flag")
parser.add_argument("--set-image", default=None, type=valid_msd_image_name, help="Change the image")
parser.add_argument("--eject", action="store_true", help="Eject the image")
options = parser.parse_args(argv[1:])
if config.kvmd.msd.type != "otg":
raise SystemExit(f"Error: KVMD MSD not using 'otg'"
f" (now configured {config.kvmd.msd.type!r})")
if options.reset:
_reset_msd()
if options.eject:
_set_param(config.otg.gadget, "file", "")
if options.set_cdrom is not None:
_set_param(config.otg.gadget, "cdrom", options.set_cdrom)
if options.set_ro is not None:
_set_param(config.otg.gadget, "ro", options.set_ro)
if options.set_image:
path = os.path.join(config.kvmd.msd.storage, "images", options.set_image)
if not os.path.isfile(path):
raise SystemExit(f"Can't find image {path!r}")
_set_param(config.otg.gadget, "file", path)
print(yaml.dump({ # type: ignore
name: _get_param(config.otg.gadget, param)
for (param, name) in [
("file", "image"),
("cdrom", "cdrom"),
("ro", "ro"),
]
}, default_flow_style=False, sort_keys=False), end="")