Files
pyquarantine-milter/pymodmilter/storage.py
2021-09-21 00:35:12 +02:00

308 lines
10 KiB
Python

# PyMod-Milter 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.
#
# PyMod-Milter 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 PyMod-Milter. If not, see <http://www.gnu.org/licenses/>.
#
__all__ = [
"BaseMailStorage",
"FileMailStorage",
"Quarantine"]
import json
import logging
import os
from calendar import timegm
from datetime import datetime
from glob import glob
from time import gmtime
from pymodmilter.base import CustomLogger
class BaseMailStorage:
"Mail storage base class"
_headersonly = True
def __init__(self, original=False, metadata=False, metavar=None):
self.original = original
self.metadata = metadata
self.metavar = metavar
return
def add(self, data, qid, mailfrom="", recipients=[]):
"Add email to storage."
return ("", "")
def execute(self, milter, pretend=False,
logger=logging.getLogger(__name__)):
return
def find(self, mailfrom=None, recipients=None, older_than=None):
"Find emails in storage."
return
def get_metadata(self, storage_id):
"Return metadata of email in storage."
return
def delete(self, storage_id, recipients=None):
"Delete email from storage."
return
def get_mail(self, storage_id):
"Return email and metadata."
return
class FileMailStorage(BaseMailStorage):
"Storage class to store mails on filesystem."
_headersonly = False
def __init__(self, directory, original=False, metadata=False,
metavar=None):
super().__init__(original, metadata, metavar)
# check if directory exists and is writable
if not os.path.isdir(directory) or \
not os.access(directory, os.W_OK):
raise RuntimeError(
f"directory '{directory}' does not exist or is "
f"not writable")
self.directory = directory
self._metadata_suffix = ".metadata"
def get_storageid(self, qid):
timestamp = datetime.now().strftime("%Y%m%d%H%M%S")
return f"{timestamp}_{qid}"
def _get_file_paths(self, storage_id):
datafile = os.path.join(self.directory, storage_id)
metafile = f"{datafile}{self._metadata_suffix}"
return metafile, datafile
def _save_datafile(self, datafile, data):
try:
with open(datafile, "wb") as f:
f.write(data)
except IOError as e:
raise RuntimeError(f"unable save data file: {e}")
def _save_metafile(self, metafile, metadata):
try:
with open(metafile, "w") as f:
json.dump(metadata, f, indent=2)
except IOError as e:
raise RuntimeError(f"unable to save metadata file: {e}")
def _remove(self, storage_id):
metafile, datafile = self._get_file_paths(storage_id)
try:
if self.metadata:
os.remove(metafile)
os.remove(datafile)
except IOError as e:
raise RuntimeError(f"unable to remove file: {e}")
def add(self, data, qid, mailfrom="", recipients=[], subject=""):
"Add email to file storage and return storage id."
super().add(data, qid, mailfrom, recipients)
storage_id = self.get_storageid(qid)
metafile, datafile = self._get_file_paths(storage_id)
# save mail
self._save_datafile(datafile, data)
if not self.metadata:
return storage_id, None, datafile
# save metadata
metadata = {
"mailfrom": mailfrom,
"recipients": recipients,
"subject": subject,
"timestamp": timegm(gmtime()),
"queue_id": qid}
try:
self._save_metafile(metafile, metadata)
except RuntimeError as e:
os.remove(datafile)
raise e
return storage_id, metafile, datafile
def execute(self, milter, pretend=False,
logger=logging.getLogger(__name__)):
if self.original:
milter.fp.seek(0)
data = milter.fp.read
mailfrom = milter.mailfrom
recipients = list(milter.rcpts)
subject = ""
else:
data = milter.msg.as_bytes
mailfrom = milter.msginfo["mailfrom"]
recipients = list(milter.msginfo["rcpts"])
subject = milter.msg["subject"] or ""
if not pretend:
storage_id, metafile, datafile = self.add(
data(), milter.qid, mailfrom, recipients, subject)
logger.info(f"stored message in file {datafile}")
else:
storage_id = self.get_storageid(milter.qid)
metafile, datafile = self._get_file_paths(storage_id)
if self.metavar:
milter.msginfo["vars"][f"{self.metavar}_ID"] = storage_id
milter.msginfo["vars"][f"{self.metavar}_DATAFILE"] = datafile
if self.metadata:
milter.msginfo["vars"][f"{self.metavar}_METAFILE"] = metafile
def get_metadata(self, storage_id):
"Return metadata of email in storage."
super(FileMailStorage, self).get_metadata(storage_id)
if not self.metadata:
return None
metafile, _ = self._get_file_paths(storage_id)
if not os.path.isfile(metafile):
raise RuntimeError(
f"invalid storage id '{storage_id}'")
try:
with open(metafile, "r") as f:
metadata = json.load(f)
except IOError as e:
raise RuntimeError(f"unable to read metadata file: {e}")
except json.JSONDecodeError as e:
raise RuntimeError(
f"invalid metafile '{metafile}': {e}")
return metadata
def find(self, mailfrom=None, recipients=None, older_than=None):
"Find emails in storage."
super(FileMailStorage, self).find(mailfrom, recipients, older_than)
if isinstance(mailfrom, str):
mailfrom = [mailfrom]
if isinstance(recipients, str):
recipients = [recipients]
if not self.metadata:
return {}
emails = {}
metafiles = glob(os.path.join(
self.directory, f"*{self._metadata_suffix}"))
for metafile in metafiles:
if not os.path.isfile(metafile):
continue
storage_id = os.path.basename(
metafile[:-len(self._metadata_suffix)])
metadata = self.get_metadata(storage_id)
if older_than is not None:
if timegm(gmtime()) - metadata["date"] < (older_than * 86400):
continue
if mailfrom is not None:
if metadata["mailfrom"] not in mailfrom:
continue
if recipients is not None:
if len(recipients) == 1 and \
recipients[0] not in metadata["recipients"]:
continue
elif len(set(recipients + metadata["recipients"])) == \
len(recipients + metadata["recipients"]):
continue
emails[storage_id] = metadata
return emails
def delete(self, storage_id, recipients=None):
"Delete email from storage."
super(FileMailStorage, self).delete(storage_id, recipients)
if not recipients or not self.metadata:
self._remove(storage_id)
return
try:
metadata = self.get_metadata(storage_id)
except RuntimeError as e:
raise RuntimeError(f"unable to delete email: {e}")
metafile, _ = self._get_file_paths(storage_id)
if type(recipients) == str:
recipients = [recipients]
for recipient in recipients:
if recipient not in metadata["recipients"]:
raise RuntimeError(f"invalid recipient '{recipient}'")
metadata["recipients"].remove(recipient)
if not metadata["recipients"]:
self._remove(storage_id)
else:
self._save_metafile(metafile, metadata)
def get_mail(self, storage_id):
super(FileMailStorage, self).get_mail(storage_id)
metadata = self.get_metadata(storage_id)
_, datafile = self._get_file_paths(storage_id)
try:
data = open(datafile, "rb").read()
except IOError as e:
raise RuntimeError(f"unable to open email data file: {e}")
return (metadata, data)
class Quarantine:
"Quarantine class."
_headersonly = False
def __init__(self, storage, notification=None, milter_action=None,
reject_reason="Message rejected"):
self.storage = storage.action(**storage.args, metadata=True)
self.storage_name = storage.name
self.storage_logger = storage.logger
self.notification = notification
if self.notification is not None:
self.notification = notification.action(**notification.args)
self.notification_name = notification.name
self.notification_logger = notification.logger
self.milter_action = milter_action
self.reject_reason = reject_reason
def execute(self, milter, pretend=False,
logger=logging.getLogger(__name__)):
custom_logger = CustomLogger(
self.storage_logger, {"name": self.storage_name})
self.storage.execute(milter, pretend, custom_logger)
if self.notification is not None:
custom_logger = CustomLogger(
self.notification_logger, {"name": self.notification_name})
self.notification.execute(milter, pretend, custom_logger)
milter.msginfo["rcpts"] = []
if self.milter_action is not None:
return (self.milter_action, self.reject_reason)