Add an EnforceDistinctSubnets option so that clients who know what they are doing (mainly people with private testing networks) can disable our same-/16 detection.

svn:r8504

src/or/config.c

@@ -152,6 +152,7 @@ static config_var_t _option_vars[] = {
   VAR("DirPort",             UINT,     DirPort,              "0"),
   OBSOLETE("DirPostPeriod"),
   VAR("DirServer",           LINELIST, DirServers,           NULL),
+  VAR("EnforceDistinctSubnets", BOOL,  EnforceDistinctSubnets,"1"),
   VAR("EntryNodes",          STRING,   EntryNodes,           NULL),
   VAR("ExcludeNodes",        STRING,   ExcludeNodes,         NULL),
   VAR("ExitNodes",           STRING,   ExitNodes,            NULL),

src/or/or.h

@@ -1581,6 +1581,8 @@ typedef struct {
   char *ServerDNSResolvConfFile; /**< If provided, we configure our internal
                      * resolver from the file here rather than from
                      * /etc/resolv.conf (Unix) or the registry (Windows). */
+  int EnforceDistinctSubnets; /** If true, don't allow multiple routers in the
+                               * same network zone in the same circuit. */
 } or_options_t;
 
 /** Persistent state for an onion router, as saved to disk. */

src/or/routerlist.c

@@ -629,10 +629,12 @@ routerlist_add_family(smartlist_t *sl, routerinfo_t *router)
 {
   routerinfo_t *r;
   config_line_t *cl;
+  or_options_t *options = get_options();
 
   /* First, add any routers with similar network addresses.
    * XXX It's possible this will be really expensive; we'll see. */
-  routerlist_add_network_family(sl, router);
+  if (options->EnforceDistinctSubnets)
+    routerlist_add_network_family(sl, router);
 
   if (!router->declared_family)
     return;