Initial commit of source code and docs

pyquarantine/whitelists.py

@@ -0,0 +1,141 @@
+#!/usr/bin/env python2
+#
+# PyQuarantine-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.
+# 
+# PyQuarantine-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 PyQuarantineMilter.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+import datetime
+import logging
+import peewee
+import re
+import sys
+from playhouse.db_url import connect
+
+
+
+class WhitelistModel(peewee.Model):
+    mailfrom = peewee.CharField()
+    recipient = peewee.CharField()
+    created = peewee.DateTimeField(default=datetime.datetime.now)
+    last_used = peewee.DateTimeField(default=datetime.datetime.now)
+    comment = peewee.TextField(default="")
+    permanent = peewee.BooleanField(default=False)
+
+
+
+class Meta(object):
+    indexes = (
+        (('mailfrom', 'recipient'), True), # trailing comma is mandatory if only one index should be created
+    )
+
+
+
+class Whitelist(object):
+    "Whitelist base class"
+    _whitelists = {}
+
+    def __init__(self, name, config, configtest=False):
+        self.name = name
+        self.config = config[name]
+        self.global_config = config["global"]
+        self.logger = logging.getLogger(__name__)
+        # check if mandatory options are present in config
+        for option in ["whitelist_table"]:
+            if option not in self.config.keys() and option in self.global_config.keys():
+                self.config[option] = self.global_config[option]
+            if option not in self.config.keys():
+                raise RuntimeError("mandatory option '{}' not present in config section '{}' or 'global'".format(option, self.name))
+        self.tablename = self.config["whitelist_table"]
+        connection_string = self.config["whitelist"]
+        if connection_string in Whitelist._whitelists.keys():
+            self.db = Whitelist._whitelists[connection_string]
+            return
+        try:
+            # connect to database
+            self.logger.debug("connecting to database '{}'".format(re.sub(r"(.*?://.*?):.*?(@.*)", r"\1:<PASSWORD>\2", connection_string)))
+            self.db = connect(connection_string)
+        except Exception as e:
+            raise RuntimeError("unable to connect to database: {}".format(e))
+        else:
+            Whitelist._whitelists[connection_string] = self.db
+        if configtest: return
+        self.Meta = Meta
+        self.Meta.database = self.db
+        self.Meta.table_name = self.tablename
+        self.Whitelist = type("WhitelistModel_{}".format(name), (WhitelistModel,), {
+            "Meta": self.Meta 
+        })
+        try:
+            self.db.create_tables([self.Whitelist])
+        except Exception as e:
+            raise RuntimeError("unable to initialize table '{}': {}".format(self.tablename, e))
+
+    def get_weight(self, entry):
+        value = 0
+        for address in [entry.mailfrom, entry.recipient]:
+            if address == "":
+                value += 2
+            elif address[0] == "@":
+                value += 1
+        return value
+
+    def check(self, mailfrom, recipient):
+        # generate list of possible mailfroms
+        self.logger.debug("query database for whitelist entries from <{}> to <{}>".format(mailfrom, recipient))
+        mailfroms = [""]
+        if "@" in mailfrom:
+            mailfroms.append("@{}".format(mailfrom.split("@")[1]))
+        mailfroms.append(mailfrom)
+        # generate list of possible recipients
+        recipients = [""]
+        if "@" in recipient:
+            recipients.append("@{}".format(recipient.split("@")[1]))
+        recipients.append(recipient)
+        # query the database
+        try:
+            entries = list(self.Whitelist.select().where(self.Whitelist.mailfrom.in_(mailfroms), self.Whitelist.recipient.in_(recipients)))
+        except Exception as e:
+            entries = []
+            self.logger.error("unable to query whitelist database: {}".format(e))
+        if len(entries) == 0:
+            # no whitelist entry found
+            return False 
+        print(entries)
+        if len(entries) > 1:
+            entries.sort(key=lambda x: self.get_weight(x))
+        # use entry with the highest weight
+        entry = entries[-1]
+        entry.last_used = datetime.datetime.now()
+        entry.save()
+        return True
+
+
+
+class WhitelistCache(object):
+    def __init__(self):
+        self.cache = {}
+
+    def load(self, whitelist, mailfrom, recipients):
+        for recipient in recipients:
+            self.check(whitelist, mailfrom, recipient)
+
+    def check(self, whitelist, mailfrom, recipient):
+        if whitelist not in self.cache.keys(): self.cache[whitelist] = {}
+        if recipient not in self.cache[whitelist].keys(): self.cache[whitelist][recipient] = None
+        if self.cache[whitelist][recipient] == None:
+            self.cache[whitelist][recipient] = whitelist.check(mailfrom, recipient)
+        return self.cache[whitelist][recipient]
+
+    def get_whitelisted_recipients(self, whitelist, mailfrom, recipients):
+        self.load(whitelist, mailfrom, recipients)
+        return filter(lambda x: self.cache[whitelist][x] == True, self.cache[whitelist].keys())