Mini Shell

"""
Usage /opt/imunify360/venv/bin/python3 rules_checker.py <action>
    choose an action from ACTIONS map
    e.g.
    /opt/imunify360/venv/bin/python3 rules_checker.py recreate

    Actions:
        - `recreate` - recreates rules if needed and checks ipsets consistent
        - `clear` - waits RulesChecker stop and destroys all rules and ipsets

    Actions based on lazy_init plugin
        placed in im360.plugins.protector.lazy_init
"""

import asyncio
from pathlib import Path
import os
import pickle
import sys
import time

from defence360agent.internals import logger as lg
from defence360agent.internals.global_scope import g
from defence360agent.model import instance, tls_check
from defence360agent.contracts.config import Model, Merger
from im360.contracts.config import IPSET_LISTS_PATH
from im360.files import WHITELISTS, Index
from im360.internals.core import ip_versions
from im360.internals.strategy import Strategy

from im360.plugins.protector import RULES_CHECK_IN_PROGRESS
from im360.plugins.protector.lazy_init import (
    RulesChecker,
    RealProtector,
)
from im360.subsys import smtp_blocking

from logging import getLogger

logger = getLogger("rules-checker")
STATE = {"last_ipset_check": 0.0}
DAY = 24 * 60 * 60


async def _check_for_config_change(rc: RulesChecker, rp: RealProtector):
    """Checking that config state is consistent with the current state."""
    rp._rules_checker = rc
    await rp._rules_checker.check_smtp_state_and_reset()
    await rp._on_config_update_unlocked(None)


async def recreate_rules(rc: RulesChecker, rp: RealProtector):
    """Recreates rules if needed and checks ipsets consistent."""
    logger.info("Checking that need to recreate rules")
    # TODO: check if we need to check it too often
    # for Python implementation we do it only once per day
    if time.time() - STATE["last_ipset_check"] < DAY:
        logger.info("Skip ipsets check")
    else:
        await rc._check_ipsets_consistent()
        STATE["last_ipset_check"] = time.time()
    await rc.recreate_rules_if_needed()
    await _check_for_config_change(rc, rp)
    logger.info("IP sets verification and initialization completed")


async def check_config_update(rc: RulesChecker, rp: RealProtector):
    """Checking config update."""
    logger.info("Checking config update")
    await _check_for_config_change(rc, rp)
    logger.info("Completed")


async def recreate_rules_on_strategy_change(
    rc: RulesChecker, rp: RealProtector
):
    """Recreates rules if needed and checks ipsets consistent."""
    logger.info("Checking that need to recreate rules on strategy change")
    await rc.recreate_rules_if_needed()
    logger.info(
        "Firewall rules recreated due to StrategyChange %s", Strategy.current
    )


async def check_ipsets_consistent(rc: RulesChecker, rp: RealProtector):
    """Check ipsets consistent."""
    logger.info("Checking ipsets consistent")
    await rc._check_ipsets_consistent()
    STATE["last_ipset_check"] = time.time()
    if any(sets for sets in rc.outdated_ipsets.values()):
        await rc.recreate_rules_if_needed()
        await _check_for_config_change(rc, rp)
    logger.info("Completed")


async def clear_everything(rc: RulesChecker, rp: RealProtector):
    """Clear rules and ipsets on stop."""
    logger.info("Clear rules and ipsets")
    rc.should_stop()
    await rc.wait()
    await rc.clear_everything()
    logger.info("Completed")


def setup_environment():
    """Setup environment for rules checker."""
    lg.reconfigure()
    ip_versions.init()
    instance.db.init(Model.PATH)
    instance.db.execute_sql("ATTACH ? AS resident", (Model.RESIDENT_PATH,))
    instance.db.execute_sql("ATTACH ? AS ipsetlists", (IPSET_LISTS_PATH,))
    if os.environ.get("DEBUG") == "true":
        g.DEBUG = True

    Index.add_type(WHITELISTS, "whitelist/v2", 0o770, 0o660, all_zip=True)


class RealProtectorState:
    """RealProtector state to save and restore."""

    def __init__(self, _ws, _pb_dmv, _pbm, _lic):
        self._webshield_status = _ws
        self._port_blocking_deny_mode_values = _pb_dmv
        self._port_blocking_mode = _pbm
        self.last_ipset_check = _lic

    def __str__(self) -> str:
        return (
            "RealProtectorState("
            f"_webshield_status={self._webshield_status}, "
            f"_port_blocking_mode={self._port_blocking_mode}, "
            "_port_blocking_deny_mode_values"
            f"={self._port_blocking_deny_mode_values},"
            f"last_ipset_check={self.last_ipset_check})"
        )


class RulesCheckerState:
    def __init__(self, interface_conf, ipset_outdated_events, outdated_ipsets):
        self._interface_conf = interface_conf
        self._ipsets_outdated_events = ipset_outdated_events
        self.outdated_ipsets = outdated_ipsets

    def __str__(self) -> str:
        return (
            "RulesCheckerState("
            f"_interface_conf={self._interface_conf}, "
            f"_ipsets_outdated_events={self._ipsets_outdated_events})"
            f"outdated_ipsets={self.outdated_ipsets})"
        )


class SmtpSettingsState:
    def __init__(self, active_settings):
        self._active_settings = active_settings

    def __str__(self) -> str:
        return f"SmtpSettingsState(_active_settings={self._active_settings})"


def restore_state(rp: RealProtector, rc: RulesChecker):
    """Restore RealProtector state."""
    Strategy.current = Strategy.get()
    try:
        if REAL_PROTECTOR_STATE.exists():
            rp_state = pickle.load(REAL_PROTECTOR_STATE.open("rb"))
            rp._webshield_status = rp_state._webshield_status
            rp._port_blocking_deny_mode_values = (
                rp_state._port_blocking_deny_mode_values
            )
            rp._port_blocking_mode = rp_state._port_blocking_mode
            STATE["last_ipset_check"] = rp_state.last_ipset_check
    except Exception as e:
        logger.error("Failed to restore RealProtector state: %s", e)
    try:
        if RULES_CHECKER_STATE.exists():
            rc_state = pickle.load(RULES_CHECKER_STATE.open("rb"))
            rc.active_interface_conf = rc_state._interface_conf
            rc._ipsets_outdated_events = rc_state._ipsets_outdated_events
            rc.outdated_ipsets = rc_state.outdated_ipsets
    except Exception as e:
        logger.error("Failed to restore RulesChecker state: %s", e)
    try:
        if SMTP_BLOCKING_STATE.exists():
            smtp_state = pickle.load(SMTP_BLOCKING_STATE.open("rb"))
            for idx, version in enumerate(smtp_blocking.ip_versions.enabled()):
                smtp_instance = smtp_blocking.SMTPBlocking(version)
                smtp_instance.active_settings = smtp_state._active_settings[
                    idx
                ]
    except Exception as e:
        logger.error("Failed to restore SMTPBlocking state: %s", e)
    return rp, rc


def save_state(rp: RealProtector, rc: RulesChecker):
    """Save RealProtector state."""
    rp_state = RealProtectorState(
        rp._webshield_status,
        rp._port_blocking_deny_mode_values,
        rp._port_blocking_mode,
        STATE["last_ipset_check"],
    )
    rc_state = RulesCheckerState(
        rc.active_interface_conf,
        rc._ipsets_outdated_events,
        rc.outdated_ipsets,
    )
    smtp_state = SmtpSettingsState(smtp_blocking.get_active_settings_list())
    pickle.dump(rp_state, REAL_PROTECTOR_STATE.open("wb"))
    pickle.dump(rc_state, RULES_CHECKER_STATE.open("wb"))
    pickle.dump(smtp_state, SMTP_BLOCKING_STATE.open("wb"))


ACTIONS = {
    "recreate": recreate_rules,
    "clear": clear_everything,
    "config-update": check_config_update,
    "strategy-change": recreate_rules_on_strategy_change,
    "ipsets-consistent": check_ipsets_consistent,
}
REAL_PROTECTOR_STATE = Path("/var/imunify360/.realprotector.state")
RULES_CHECKER_STATE = Path("/var/imunify360/.ruleschecker.state")
SMTP_BLOCKING_STATE = Path("/var/imunify360/.smtp_blocking.state")


def main(action):
    try:
        RULES_CHECK_IN_PROGRESS.touch()
    except Exception as e:
        logger.error("Failed to create RULES_CHECK_IN_PROGRESS file: %s", e)
    tls_check.reset()
    setup_environment()
    try:
        Merger.update_merged_config()
    except Exception as e:
        logger.error("Failed to update merged config: %r", e)
    loop = asyncio.get_event_loop()
    rp, rc = restore_state(RealProtector(), RulesChecker(loop))

    if action not in ACTIONS:
        print(
            f"Invalid action: {action}. "
            f"Choose from {', '.join(ACTIONS.keys())}"
        )
        RULES_CHECK_IN_PROGRESS.unlink(missing_ok=True)
        sys.exit(1)

    action = ACTIONS[action]
    loop.run_until_complete(action(rc, rp))
    save_state(rp, rc)
    RULES_CHECK_IN_PROGRESS.unlink(missing_ok=True)
    logger.info("Script finished")


if __name__ == "__main__":
    if len(sys.argv) != 2:
        print(
            "Please provide one action as command line argument."
            f" {', '.join(ACTIONS.keys())}"
        )
        sys.exit(1)

    main(sys.argv[1])