diff --git a/src/upstream.c b/src/upstream.c
index 327b727..c84bad2 100644
--- a/src/upstream.c
+++ b/src/upstream.c
@@ -43,6 +43,35 @@ proxy_type_name(proxy_type type)
     }
 }
 
+/**
+ * Parse and process a netmask format (IP/mask), otherwise treat as a domain
+ */
+static void upstream_handle_site_spec(struct upstream *up, const char *domain)
+{
+        char *ptr;
+
+        ptr = strchr (domain, '/');
+        if (ptr) {
+                struct in_addr addrstruct;
+
+                *ptr = '\0';
+                if (inet_aton (domain, &addrstruct) != 0) {
+                        up->ip = ntohl (addrstruct.s_addr);
+                        *ptr++ = '/';
+
+                        if (strchr (ptr, '.')) {
+                                if (inet_aton (ptr, &addrstruct) != 0)
+                                        up->mask =
+                                            ntohl (addrstruct.s_addr);
+                        } else {
+                                up->mask =
+                                    ~((1 << (32 - atoi (ptr))) - 1);
+                        }
+                }
+        } else {
+                up->domain = safestrdup (domain);
+        }
+}
 /**
  * Construct an upstream struct from input data.
  */
@@ -50,7 +79,6 @@ static struct upstream *upstream_build (const char *host, int port, const char *
                         const char *user, const char *pass,
 			proxy_type type)
 {
-        char *ptr;
         struct upstream *up;
 
         up = (struct upstream *) safemalloc (sizeof (struct upstream));
@@ -99,27 +127,7 @@ static struct upstream *upstream_build (const char *host, int port, const char *
                         goto fail;
                 }
 
-                ptr = strchr (domain, '/');
-                if (ptr) {
-                        struct in_addr addrstruct;
-
-                        *ptr = '\0';
-                        if (inet_aton (domain, &addrstruct) != 0) {
-                                up->ip = ntohl (addrstruct.s_addr);
-                                *ptr++ = '/';
-
-                                if (strchr (ptr, '.')) {
-                                        if (inet_aton (ptr, &addrstruct) != 0)
-                                                up->mask =
-                                                    ntohl (addrstruct.s_addr);
-                                } else {
-                                        up->mask =
-                                            ~((1 << (32 - atoi (ptr))) - 1);
-                                }
-                        }
-                } else {
-                        up->domain = safestrdup (domain);
-                }
+                upstream_handle_site_spec(up, domain);
 
                 log_message (LOG_INFO, "Added no-upstream for %s", domain);
         } else {