Custom domains: don't allow IPs (#9429)

Closes readthedocs/readthedocs-ext#516

Author: stsewd

readthedocs/projects/migrations/0090_dont_allow_ips_on_domains.py

@@ -0,0 +1,28 @@
+# Generated by Django 3.2.13 on 2022-07-12 21:56
+
+from django.db import migrations, models
+
+import readthedocs.projects.validators
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("projects", "0089_update_help_text"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="domain",
+            name="domain",
+            field=models.CharField(
+                max_length=255,
+                unique=True,
+                validators=[
+                    readthedocs.projects.validators.DomainNameValidator(),
+                    readthedocs.projects.validators.NoIPValidator(),
+                ],
+                verbose_name="Domain",
+            ),
+        ),
+    ]

readthedocs/projects/models.py

@@ -43,6 +43,7 @@
 from readthedocs.projects.templatetags.projects_tags import sort_version_aware
 from readthedocs.projects.validators import (
     validate_domain_name,
+    validate_no_ip,
     validate_repository_url,
 )
 from readthedocs.projects.version_handling import determine_stable_version
@@ -1643,7 +1644,7 @@ class Domain(TimeStampedModel, models.Model):
         _('Domain'),
         unique=True,
         max_length=255,
-        validators=[validate_domain_name],
+        validators=[validate_domain_name, validate_no_ip],
     )
     machine = models.BooleanField(
         default=False,

readthedocs/projects/validators.py

@@ -22,6 +22,16 @@ class DomainNameValidator(RegexValidator):
 validate_domain_name = DomainNameValidator()
 
 
+@deconstructible
+class NoIPValidator(RegexValidator):
+    message = _("The domain name can't be an IP address.")
+    regex = re.compile(r"^(\d+\.)+\d+$")
+    inverse_match = True
+
+
+validate_no_ip = NoIPValidator()
+
+
 @deconstructible
 class RepositoryURLValidator:
 

readthedocs/rtd_tests/tests/test_domains.py

@@ -1,5 +1,3 @@
-import json
-
 from django.conf import settings
 from django.test import TestCase, override_settings
 from django_dynamic_fixture import get
@@ -123,15 +121,19 @@ def test_valid_domains(self):
 
     def test_invalid_domains(self):
         domains = [
-            'python..org',
-            '****.foo.com',
-            'domain',
-            'domain.com.',
-            'My domain.org',
-            'i.o',
-            '[special].com',
-            'some_thing.org',
-            'invalid-.com',
+            "python..org",
+            "****.foo.com",
+            "domain",
+            "domain.com.",
+            "My domain.org",
+            "i.o",
+            "[special].com",
+            "some_thing.org",
+            "invalid-.com",
+            "1.1.1.1",
+            "1.23.45.67",
+            "127.0.0.1",
+            "127.0.0.10",
         ]
         for domain in domains:
             form = DomainForm(