Merge #1916

1916: Ratelimit outgoing emails per user r=mergify[bot] a=nextgens

## What type of PR?

Feature

## What does this PR do?

A conflict-free version of #1360 implementing per-user sender limits

### Related issue(s)
- close #1360 
- close #1031
- close #1774 

## Prerequistes
Before we can consider review and merge, please make sure the following list is done and checked.
If an entry in not applicable, you can check it or remove it from the list.

- [x] In case of feature or enhancement: documentation updated accordingly
- [x] Unless it's docs or a minor change: add [changelog](https://mailu.io/master/contributors/workflow.html#changelog) entry file.


Co-authored-by: Florent Daigniere <nextgens@freenetproject.org>
Co-authored-by: Dimitri Huisman <diman@huisman.xyz>

core/admin/mailu/configuration.py

@@ -46,6 +46,7 @@ DEFAULT_CONFIG = {
     'DKIM_SELECTOR': 'dkim',
     'DKIM_PATH': '/dkim/{domain}.{selector}.key',
     'DEFAULT_QUOTA': 1000000000,
+    'MESSAGE_RATELIMIT': '200/day',
     # Web settings
     'SITENAME': 'Mailu',
     'WEBSITE': 'https://mailu.io',

core/admin/mailu/internal/views/postfix.py

@@ -1,5 +1,6 @@
-from mailu import models
+from mailu import models, utils
 from mailu.internal import internal
+from flask import current_app as app
 
 import flask
 import idna
@@ -31,7 +32,6 @@ def postfix_alias_map(alias):
     destination = models.Email.resolve_destination(localpart, domain_name)
     return flask.jsonify(",".join(destination)) if destination else flask.abort(404)
 
-
 @internal.route("/postfix/transport/<path:email>")
 def postfix_transport(email):
     if email == '*' or re.match("(^|.*@)\[.*\]$", email):
@@ -139,6 +139,12 @@ def postfix_sender_login(sender):
     destination = models.Email.resolve_destination(localpart, domain_name, True)
     return flask.jsonify(",".join(destination)) if destination else flask.abort(404)
 
+@internal.route("/postfix/sender/rate/<path:sender>")
+def postfix_sender_rate(sender):
+    """ Rate limit outbound emails per sender login
+    """
+    user = models.User.get(sender) or flask.abort(404)
+    return flask.abort(404) if user.sender_limiter.hit() else flask.jsonify("450 4.2.1 You are sending too many emails too fast.")
 
 @internal.route("/postfix/sender/access/<path:sender>")
 def postfix_sender_access(sender):

core/admin/mailu/models.py

@@ -27,7 +27,7 @@ from sqlalchemy.ext.hybrid import hybrid_property
 from sqlalchemy.inspection import inspect
 from werkzeug.utils import cached_property
 
-from mailu import dkim
+from mailu import dkim, utils
 
 
 db = flask_sqlalchemy.SQLAlchemy()
@@ -501,6 +501,12 @@ class User(Base, Email):
             self.reply_enddate > now
         )
 
+    @property
+    def sender_limiter(self):
+        return utils.limiter.get_limiter(
+            app.config["MESSAGE_RATELIMIT"], "sender", self.email
+        )
+
     @classmethod
     def get_password_context(cls):
         """ create password context for hashing and verification

core/admin/mailu/ui/templates/user/list.html

@@ -19,7 +19,8 @@
   <th>{% trans %}User settings{% endtrans %}</th>
   <th>{% trans %}Email{% endtrans %}</th>
   <th>{% trans %}Features{% endtrans %}</th>
-  <th>{% trans %}Quota{% endtrans %}</th>
+  <th>{% trans %}Storage Quota{% endtrans %}</th>
+  <th>{% trans %}Sending Quota{% endtrans %}</th>
   <th>{% trans %}Comment{% endtrans %}</th>
   <th>{% trans %}Created{% endtrans %}</th>
   <th>{% trans %}Last edit{% endtrans %}</th>
@@ -41,6 +42,8 @@
     {% if user.enable_pop %}<span class="label label-info">pop3</span>{% endif %}
   </td>
   <td>{{ user.quota_bytes_used | filesizeformat }} / {{ (user.quota_bytes | filesizeformat) if user.quota_bytes else '∞' }}</td>
+  {% set limiter = user.sender_limiter %}
+  <td>{{ limiter.get_window_stats()[1] }} / {{ limiter.limit }}</td>
   <td>{{ user.comment or '-' }}</td>
   <td>{{ user.created_at }}</td>
   <td>{{ user.updated_at or '' }}</td>

core/postfix/conf/main.cf

@@ -101,6 +101,8 @@ smtpd_sender_login_maps = ${podop}senderlogin
 # Restrictions for incoming SMTP, other restrictions are applied in master.cf
 smtpd_helo_required = yes
 
+check_ratelimit = check_sasl_access ${podop}senderrate
+
 smtpd_client_restrictions =
   permit_mynetworks,
   check_sender_access ${podop}senderaccess,

core/postfix/conf/master.cf

@@ -7,7 +7,8 @@ smtp      inet  n       -       n       -       -       smtpd
 # Internal SMTP service
 10025     inet  n       -       n       -       -       smtpd
   -o smtpd_sasl_auth_enable=yes
-  -o smtpd_client_restrictions=reject_unlisted_sender,reject_authenticated_sender_login_mismatch,permit
+  -o smtpd_discard_ehlo_keywords=pipelining
+  -o smtpd_client_restrictions=$check_ratelimit,reject_unlisted_sender,reject_authenticated_sender_login_mismatch,permit
   -o smtpd_reject_unlisted_recipient={% if REJECT_UNLISTED_RECIPIENT %}{{ REJECT_UNLISTED_RECIPIENT }}{% else %}no{% endif %}
   -o cleanup_service_name=outclean
 outclean  unix n       -       n       -       0       cleanup

core/postfix/start.py

@@ -26,7 +26,8 @@ def start_podop():
         ("recipientmap", "url", url + "recipient/map/§"),
         ("sendermap", "url", url + "sender/map/§"),
         ("senderaccess", "url", url + "sender/access/§"),
-        ("senderlogin", "url", url + "sender/login/§")
+        ("senderlogin", "url", url + "sender/login/§"),
+        ("senderrate", "url", url + "sender/rate/§")
     ])
 
 def is_valid_postconf_line(line):

docs/webadministration.rst

@@ -315,6 +315,21 @@ This page is also accessible for domain managers. On the users page new users ca
 
 * Fetched accounts. Access the fetched accounts page of the user. See the :ref:`fetched accounts page <webadministration_fetched_accounts>` for more information.
 
+This page also shows an overview of the following settings of an user:
+
+* Email. The email address of the user.
+
+* Features. Shows if IMAP or POP3 access is enabled.
+
+* Storage quota. Shows how much assigned storage has been consumed.
+
+* Sending Quota. The sending quota is the limit of messages a single user can send per day. 
+
+* Comment. A desription for the user. 
+
+* Created. Date when the user was created.
+
+* Last edit. Last date when the user was modified. 
 
 .. _webadministration_add_user:
 
@@ -334,7 +349,7 @@ For adding a new user the following options can be configured.
 * Enabled. Tick this checkbox to enable the user account. When an user is disabled, the user is unable to login to the Admin GUI or webmail or access his email via IMAP/POP3 or send mail.
   The email inbox of the user is still retained. This option can be used to temporarily suspend an user account.
 
-* Quota. The maximum quota for the user's email box.
+* Storage Quota. The maximum quota for the user's email box.
 
 * Allow IMAP access. When ticked, allows email retrieval via the IMAP protocol.
 

setup/flavors/compose/mailu.env

@@ -62,6 +62,11 @@ ANTIVIRUS={{ antivirus_enabled or 'none' }}
 # Max attachment size will be 33% smaller
 MESSAGE_SIZE_LIMIT={{ message_size_limit or '50000000' }}
 
+# Message rate limit (per user)
+{% if message_ratelimit_pd > '0' %}
+MESSAGE_RATELIMIT={{ message_ratelimit_pd }}/day
+{% endif %}
+
 # Networks granted relay permissions
 # Use this with care, all hosts in this networks will be able to send mail without authentication!
 RELAYNETS=

setup/templates/steps/config.html

@@ -55,6 +55,13 @@ Or in plain english: if receivers start to classify your mail as spam, this post
   </p>
 </div>
 
+<div class="form-group">
+  <label>Outgoing message rate limit (per user)</label>
+  <!--   Validates number input only -->
+  <p><input class="form-control" style="width: 7%; display: inline;" type="number" name="message_ratelimit_pd" value="200" required > / day
+  </p>
+</div>
+
 <div class="form-check form-check-inline">
   <label class="form-check-label">
     <input class="form-check-input" type="checkbox" name="disable_statistics" value="True">

towncrier/newsfragments/1031.feature

@@ -0,0 +1 @@
+Add sending quotas per user