#!/usr/bin/env python3
#
# Copyright VyOS maintainers and contributors <maintainers@vyos.io>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# 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 <http://www.gnu.org/licenses/>.

import re
import sys

from vyos.utils.kernel import load_module
from vyos.utils.process import rc_cmd



def main() -> int:
    if len(sys.argv) < 2:
        # No value to validate
        return 1

    module = sys.argv[1].strip()
    if not module:
        return 1

    # Keep the module name format strict.
    if not re.fullmatch(r"[a-zA-Z0-9_\-]+", module):
        return 1

    # Ensure the module exists and is loadable (dry-run).
    # This does not load the module.
    try:
        rc = load_module(module, quiet=True, dry_run=True)
    except OSError:
        return 1

    if rc != 0:
        return 1

    # Validate that the module looks like a watchdog driver.
    # Use modinfo filename location as the heuristic.
    rc, out = rc_cmd(["modinfo", "-F", "filename", module])
    if rc != 0:
        return 1
    filename = (out or "").strip().lower()

    # Accept modules located under drivers/watchdog, plus explicit exception for
    # ipmi_watchdog which lives in drivers/char/ipmi.
    is_watchdog_driver = (
        ("/watchdog/" in filename)
        or filename.endswith("/ipmi_watchdog.ko")
    )

    return 0 if is_watchdog_driver else 1


if __name__ == "__main__":
    sys.exit(main())