Convert IP addresses to strings in MySQL before calling `GROUP_CONCAT()` (#19786)

* Convert IP addresses to strings in MySQL before calling GROUP_CONCAT()

This avoids issues with commas inside the bytestring representation
of the binary value, which can happen for some IPs.

src/olympia/amo/models.py

@@ -7,6 +7,8 @@ from urllib.parse import urljoin
 from django.conf import settings
 from django.core.files.storage import default_storage as storage
 from django.db import models
+from django.db.models.expressions import Func
+from django.db.models.fields import CharField
 from django.db.models.fields.related_descriptors import ManyToManyDescriptor
 from django.db.models.query import ModelIterable
 from django.urls import resolve, reverse
@@ -633,3 +635,8 @@ class FilterableManyToManyField(models.fields.related.ManyToManyField):
 class GroupConcat(models.Aggregate):
     function = 'GROUP_CONCAT'
     allow_distinct = True
+
+
+class Inet6Ntoa(Func):
+    function = 'INET6_NTOA'
+    output_field = CharField()

src/olympia/users/admin.py

@@ -6,7 +6,6 @@ from django import http
 from django.contrib import admin, messages
 from django.contrib.admin.utils import unquote
 from django.db.models import (
-    CharField,
     Count,
     F,
     FilteredRelation,
@@ -37,7 +36,7 @@ from olympia.amo.admin import (
     SEARCH_VAR,
 )
 from olympia.amo.fields import IPAddressBinaryField
-from olympia.amo.models import GroupConcat
+from olympia.amo.models import GroupConcat, Inet6Ntoa
 from olympia.api.models import APIKey, APIKeyConfirmation
 from olympia.bandwagon.models import Collection
 from olympia.ratings.models import Rating
@@ -242,11 +241,8 @@ class UserAdmin(CommaSearchInAdminMixin, admin.ModelAdmin):
             # FilteredRelation we can force it...
             annotations = {
                 'activity_ips': GroupConcat(
-                    'activitylog__iplog__ip_address_binary',
+                    Inet6Ntoa('activitylog__iplog__ip_address_binary'),
                     distinct=True,
-                    # You can't have multiple ip addresses in an IPv[4|6]Address object
-                    # so we store the binary values in a CharField instead.
-                    output_field=CharField(),
                 ),
                 'activitylog_filtered': FilteredRelation(
                     'activitylog__iplog', condition=condition
@@ -482,11 +478,12 @@ class UserAdmin(CommaSearchInAdminMixin, admin.ModelAdmin):
         # extra queries for each row of results), otherwise, look everywhere
         # we can.
         activity_ips = getattr(obj, 'activity_ips', None)
-        to_ipaddress = IPAddressBinaryField().to_python
         if activity_ips is not None:
-            # The GroupConcat value is a comma seperated string of the binary values.
-            ip_addresses = {to_ipaddress(ip) for ip in activity_ips.split(b',')}
+            # The GroupConcat value is a comma seperated string of the ip
+            # addresses (already converted to string thanks to INET6_NTOA).
+            ip_addresses = set(activity_ips.split(','))
         else:
+            to_ipaddress = IPAddressBinaryField().to_python
             ip_addresses = set(
                 Rating.objects.filter(user=obj)
                 .values_list('ip_address', flat=True)

src/olympia/users/tests/test_admin.py

@@ -127,7 +127,11 @@ class TestUserAdmin(TestCase):
             self.user.update(email='foo@bar.com')
             # That will make self.user match our query.
             ActivityLog.create(amo.LOG.LOG_IN, user=self.user)
-        with core.override_remote_addr('127.0.0.3'):
+        # 127.0.0.44 packed is b'\x7f\x00\x00,' - it's useful to test since it
+        # contains a comma character, which would trip the split(',') we do on
+        # the result of the GROUP_CONCAT if the binary value wasn't translated
+        # to an IP address string representation before being grouped.
+        with core.override_remote_addr('127.0.0.44'):
             # Add another login from a different IP to make sure we show it.
             ActivityLog.create(amo.LOG.LOG_IN, user=self.user)
         with core.override_remote_addr('127.0.0.1'):
@@ -145,7 +149,7 @@ class TestUserAdmin(TestCase):
         # Make sure it's the right user.
         assert doc('.field-email').text() == self.user.email
         # Make sure login ip is now displayed, and has the right value.
-        assert doc('.field-known_ip_adresses').text() == '127.0.0.2\n127.0.0.3'
+        assert doc('.field-known_ip_adresses').text() == '127.0.0.2\n127.0.0.44'
 
     def test_search_for_single_ip_multiple_results_for_different_reasons(self):
         user = user_factory(email='someone@mozilla.com')