Update example nginx configs to require Host match.

docs/source/deploy.rst

@@ -39,9 +39,17 @@ An `example configuration`_ file for fast clients with Nginx_::
         }
 
         server {
-            listen 80 default;
+            # If no Host match, close the connection to prevent Host spoofing
+            listen 80 default_server;
+            return 444;
+        }
+
+        server {
+            listen 80;
             client_max_body_size 4G;
-            server_name _;
+
+            # set the correct host(s) for your site
+            server_name example.com www.example.com;
 
             keepalive_timeout 5;
 

examples/nginx.conf

@@ -70,12 +70,20 @@ http {
   }
 
   server {
-    # listen 80 default deferred; # for Linux
-    # listen 80 default accept_filter=httpready; # for FreeBSD
-    listen 80 default;
+    # If no Host match, close the connection to prevent Host spoofing
+    listen 80 default_server;
+    return 444;
+  }
+
+  server {
+    # listen 80 deferred; # for Linux
+    # listen 80 accept_filter=httpready; # for FreeBSD
+    listen 80;
+
+    # set the correct host(s) for your site
+    server_name example.com www.example.com;
 
     client_max_body_size 4G;
-    server_name _;
 
     # ~2 seconds is often enough for most folks to parse HTML/CSS and
     # retrieve needed images/icons/frames, connections are cheap in