middleware: allow CIDR blocks in maintenance passthrough IPs (#73039)

tests/test_maintenance.py

@@ -39,6 +39,12 @@ def test_maintenance_page(settings):
     settings.MAINTENANCE_PASS_THROUGH_IPS = []
     resp = app.get('/', status=503)
 
+    settings.MAINTENANCE_PASS_THROUGH_IPS = ['127.0.0.1/4']
+    resp = app.get('/', status=200)
+
+    settings.MAINTENANCE_PASS_THROUGH_IPS = []
+    resp = app.get('/', status=503)
+
     with open(site_options_path, 'w') as fd:
         fd.write(
             '''\

wcs/middleware.py

@@ -14,6 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program; if not, see <http://www.gnu.org/licenses/>.
 
+import ipaddress
 import json
 import threading
 import time
@@ -133,6 +134,12 @@ def pass_through(request, pub):
         pass_through_ips = getattr(settings, 'MAINTENANCE_PASS_THROUGH_IPS', [])
         if remote_addr in pass_through_ips:
             return True
+        for network in [x for x in pass_through_ips if '/' in x]:
+            try:
+                if ipaddress.ip_address(remote_addr) in ipaddress.ip_network(network, strict=False):
+                    return True
+            except ValueError:  # bad remote_addr or network syntax
+                pass
     pass_through_header = pub.get_site_option('maintenance_pass_through_header', 'variables')
     if pass_through_header and pass_through_header in request.headers:
         return True