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Mini Shell
Mini Shell
"""
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/>.
Copyright © 2019 Cloud Linux Software Inc.
This software is also available under ImunifyAV commercial license,
see <https://www.imunify360.com/legal/eula>
"""
import asyncio
import base64
import logging
import os
import re
import shutil
from pathlib import Path
from typing import Callable, Iterable, List, Set, Tuple
from defence360agent.contracts.config import ANTIVIRUS_MODE, Malware
from defence360agent.subsys.panels.hosting_panel import HostingPanel
from defence360agent.utils import check_run
from imav.malwarelib.model import MalwareIgnorePath
from imav.malwarelib.scan.crontab import crontab_path
logger = logging.getLogger(__name__)
# location of admin provided watched and ignored paths
_ADMIN_PATH = Path("/etc/sysconfig/imunify360/malware-filters-admin-conf")
# location of internal configs, shipped with imunify360-firewall
_INTERNAL_PATH = Path("/var/imunify360/files/realtime-av-conf/v1")
# location of processed configs
_PROCESSED_PATH = _ADMIN_PATH / "processed"
_PD_NAME = "pd-combined.txt"
_INTERNAL_NAME = "av-internal.txt"
_ADMIN_NAME = "av-admin.txt"
_ADMIN_PATHS_NAME = "av-admin-paths.txt"
_IGNORED_SUB_DIR = "ignored"
_MAX_PATTERN_LENGTH = 64000
_SERVICE = "imunify-realtime-av"
_PD_PREPARE = "/usr/bin/i360-exclcomp"
class PatternLengthError(Exception):
"""Raised when pattern's length is too big."""
pass
def _save_basedirs(dir: Path, basedirs: Set[str]) -> None:
"""Save list of basedirs in a file inside dir."""
with (dir / "basedirs-list.txt").open("w") as f:
for basedir in sorted(basedirs):
f.write(os.path.realpath(basedir) + "\n")
def _split_paths(paths: List[str]) -> Tuple[List[str], List[str]]:
"""Split paths into two lists: absolute and relative.
Relative paths start with +. This + sign is removed from resulting path."""
absolute, relative = [], []
for path in paths:
if path.startswith("+"):
relative.append(path[1:])
else:
absolute.append(path)
return absolute, relative
def _read_list(path: Path) -> List[str]:
"""Read file at path and return its lines as a list.
Empty lines or lines starting with '#' symbol are skipped. Lines are
stripped of leading and trailing whitespace. If the file does not exist,
empty list is returned."""
try:
with path.open() as f:
lines = [line.strip() for line in f]
return [x for x in lines if len(x) > 0 and not x.startswith("#")]
except FileNotFoundError:
return []
class _Watched(list):
"""Holds a list of watched glob patterns ready to be saved."""
def __init__(self, w: List[str], basedirs: Set[str]) -> None:
super().__init__()
absolute, relative = _split_paths(w)
self.extend(
os.path.realpath(p)
for p in absolute + self._extend_relative(relative, basedirs)
if self._is_valid(p)
)
@staticmethod
def _is_valid(pattern: str) -> bool:
"""Return True if watched pattern is valid."""
if not pattern.startswith("/"):
logger.warning(
"skipping watched path %s: not starts with /", pattern
)
return False
return True
@staticmethod
def _extend_relative(paths: List[str], basedirs: Set[str]) -> List[str]:
"""Join basedirs with all paths and return resulting list."""
extended = []
for path in paths:
for basedir in basedirs:
extended.append(os.path.join(basedir, path))
return extended
def save(self, path: Path) -> None:
"""Save watched list at specified path."""
with path.open("w") as f:
f.write("\n".join(self))
class _Ignored(str):
"""Holds a list of ignored regexp patterns ready to be saved."""
@staticmethod
def _is_valid_relative(pattern: str) -> bool:
"""Return True if relative ignored pattern is valid."""
if pattern.startswith("^"):
logger.warning(
"skipping relative ignored path %s: starts with ^", pattern
)
return False
return True
@staticmethod
def _remove_leading_slash(pattern: str) -> str:
"""Remove leading slash from pattern, if present."""
if pattern.startswith("/"):
return pattern[1:]
return pattern
@staticmethod
def _compiles(pattern: str) -> bool:
"""Return True if pattern successfully compiles as regexp."""
try:
re.compile(pattern)
return True
except Exception:
logger.warning(
"skipping ignored pattern %s: invalid regex", pattern
)
return False
@classmethod
def from_patterns(
cls, patterns: List[str], basedirs: Set[str]
) -> "_Ignored":
"""Build single ignored regexp from given patterns and basedirs."""
absolute, relative = _split_paths(patterns)
absolute = [p for p in absolute if cls._compiles(p)]
relative = [
cls._remove_leading_slash(p)
for p in relative
if cls._is_valid_relative(p) and cls._compiles(p)
]
if len(basedirs) > 0 and len(relative) > 0:
relative_pattern = "^(?:{})/(?:{})".format(
"|".join(basedirs), "|".join(relative)
)
absolute.append(relative_pattern)
pat = "|".join(absolute)
if pat == "":
pat = "^$"
return _Ignored(pat)
def save(self, path: Path):
"""Save ignored list at specified path."""
if len(self) > _MAX_PATTERN_LENGTH:
raise PatternLengthError(
"{} pattern is too long ({})".format(path, len(self))
)
with path.open("w") as f:
f.write(self)
def _read_configs(panel: str, name: str) -> Tuple[List[str], List[str]]:
"""Read internal and admin lists from files with given name."""
common_dir = _INTERNAL_PATH / "common"
internal = _read_list(common_dir / name)
panel_path = _INTERNAL_PATH / panel.lower()
if panel_path.exists():
internal.extend(_read_list(panel_path / name))
return internal, _read_list(_ADMIN_PATH / name)
class _WatchedCtx:
def __init__(self, internal: _Watched, admin: _Watched) -> None:
self.internal = internal
self.admin = admin
def save(self, dir: Path) -> None:
w = dir / "watched"
w.mkdir(exist_ok=True)
self.internal.save(w / _INTERNAL_NAME)
self.admin.save(w / _ADMIN_NAME)
def _watched_context(
panel_name: str, basedirs: Set[str], *, extra: Iterable[str]
) -> _WatchedCtx:
internal_watched, admin_watched = _read_configs(panel_name, "watched.txt")
internal_watched.extend(extra)
return _WatchedCtx(
_Watched(internal_watched, basedirs), _Watched(admin_watched, basedirs)
)
class _IgnoredCtx:
def __init__(
self, internal: _Ignored, admin: _Ignored, pd: _Ignored
) -> None:
self.internal = internal
self.admin = admin
self.pd = pd
def save(self, dir: Path) -> None:
w = dir / _IGNORED_SUB_DIR
w.mkdir(exist_ok=True)
self.internal.save(w / _INTERNAL_NAME)
self.admin.save(w / _ADMIN_NAME)
self.pd.save(w / _PD_NAME)
def _ignored_context(panel_name: str, basedirs: Set[str]) -> _IgnoredCtx:
internal_ignored, admin_ignored = _read_configs(panel_name, "ignored.txt")
return _IgnoredCtx(
_Ignored.from_patterns(internal_ignored, basedirs),
_Ignored.from_patterns(admin_ignored, basedirs),
_Ignored.from_patterns(internal_ignored + admin_ignored, basedirs),
)
def _admin_ignored_paths(dir: Path) -> None:
ignored_paths = MalwareIgnorePath.path_list()
ignored_paths_base64 = b"".join(
base64.b64encode(os.fsencode(path)) + b"\n" for path in ignored_paths
)
target = dir / _IGNORED_SUB_DIR / _ADMIN_PATHS_NAME
target.write_bytes(ignored_paths_base64)
def _contain_changes(dir1: Path, dir2: Path) -> bool:
"""Compare content of two folders if files in this directory are the
same return False."""
for file in dir1.iterdir():
if file.is_dir():
if _contain_changes(file, dir2 / file.name):
return True
if not file.is_file():
continue
other = dir2 / file.name
if not other.exists():
return True
if file.read_bytes() != other.read_bytes():
return True
return False
def _save_configs(dir: Path, savers: List[Callable[[Path], None]]) -> bool:
"""Save configs in directory dir using saves callable.
Each function in savers will be called with single dir argument."""
temp = dir.with_suffix(".tmp")
if temp.exists():
shutil.rmtree(str(temp))
temp.mkdir()
for save in savers:
save(temp)
if dir.exists():
backup = dir.with_name(".backup")
if backup.exists():
shutil.rmtree(str(backup))
dir.rename(backup)
try:
temp.rename(dir)
except Exception:
backup.rename(dir)
raise
return _contain_changes(dir, backup)
else:
temp.rename(dir)
return True
def _update_pd_symlink() -> None:
target = _PROCESSED_PATH / _IGNORED_SUB_DIR / _PD_NAME
source = _ADMIN_PATH / _PD_NAME
try:
# source.exists() returns False for broken symlink.
# so call lstat() and if it throws exception, source does not exist.
_ = source.lstat()
except FileNotFoundError:
source.symlink_to(target)
else:
if not (
source.is_symlink() and os.readlink(str(source)) == str(target)
):
source.unlink()
source.symlink_to(target)
def generate_configs() -> bool:
"""Generate new malware paths filters config."""
panel = HostingPanel()
basedirs = panel.basedirs()
extra_watched = set()
if Malware.CRONTABS_SCAN_ENABLED:
extra_watched.add(str(crontab_path()))
changed = _save_configs(
_PROCESSED_PATH,
[
lambda dir: _save_basedirs(dir, {*basedirs, *extra_watched}),
_watched_context(panel.NAME, basedirs, extra=extra_watched).save,
_ignored_context(panel.NAME, basedirs).save,
_admin_ignored_paths,
],
)
_update_pd_symlink()
return changed
async def reload_services() -> None: # pragma: no cover
tasks = [
check_run(["service", _SERVICE, "restart"]),
check_run([_PD_PREPARE]),
]
for t in tasks:
try:
await t
except asyncio.CancelledError:
raise
except Exception as e:
logger.warning("realtime_av.reload_services exception: %s", e)
def should_be_running() -> bool:
return not ANTIVIRUS_MODE and Malware.INOTIFY_ENABLED
Zerion Mini Shell 1.0