@@ -11,8 +11,11 @@ Standalone Debug Options

      --show-gateway

      --show-gateway IPv6-target

-  If an IPv6 target address is passed as argument, the IPv6 route for this

-  host is reported.

+  For IPv6 this queries the route towards ::/128, or the specified IPv6

+  target address if passed as argument.

+  For IPv4 on Linux, Windows, MacOS and BSD it looks for a 0.0.0.0/0 route.

+  If there are more specific routes, the result will not always be matching

+  the route of the IPv4 packets to the VPN gateway.

 Advanced Expert Options

@@ -345,6 +345,13 @@ sitnl_send(struct nlmsghdr *payload, pid_t peer, unsigned int groups,

  *               continue;

  *           }

  */

+

+            if (h->nlmsg_type == NLMSG_DONE)

+            {

+                ret = 0;

+                goto out;

+            }

+

             if (h->nlmsg_type == NLMSG_ERROR)

             {

                 err = (struct nlmsgerr *)NLMSG_DATA(h);

@@ -360,7 +367,11 @@ sitnl_send(struct nlmsghdr *payload, pid_t peer, unsigned int groups,

                         ret = 0;

                         if (cb)

                         {

-                            ret = cb(h, arg_cb);

+                            int r = cb(h, arg_cb);

+                            if (r <= 0)

+                            {

+                                ret = r;

+                            }

                         }

                     }

                     else

@@ -375,8 +386,12 @@ sitnl_send(struct nlmsghdr *payload, pid_t peer, unsigned int groups,

             if (cb)

             {

-                ret = cb(h, arg_cb);

-                goto out;

+                int r = cb(h, arg_cb);

+                if (r <= 0)

+                {

+                    ret = r;

+                    goto out;

+                }

             }

             else

             {

@@ -410,6 +425,7 @@ typedef struct {

     int addr_size;

     inet_address_t gw;

     char iface[IFNAMSIZ];

+    bool default_only;

 } route_res_t;

 static int

@@ -421,6 +437,12 @@ sitnl_route_save(struct nlmsghdr *n, void *arg)

     int len = n->nlmsg_len - NLMSG_LENGTH(sizeof(*r));

     unsigned int ifindex = 0;

+    /* filter-out non-zero dst prefixes */

+    if (res->default_only && r->rtm_dst_len != 0)

+    {

+        return 1;

+    }

+

     while (RTA_OK(rta, len))

     {

         switch (rta->rta_type)

@@ -477,11 +499,25 @@ sitnl_route_best_gw(sa_family_t af_family, const inet_address_t *dst,

     {

         case AF_INET:

             res.addr_size = sizeof(in_addr_t);

-            req.n.nlmsg_flags |= NLM_F_DUMP;

+            /*

+             * kernel can't return 0.0.0.0/8 host route, dump all

+             * the routes and filter for 0.0.0.0/0 in cb()

+             */

+            if (!dst || !dst->ipv4)

+            {

+                req.n.nlmsg_flags |= NLM_F_DUMP;

+                res.default_only = true;

+            }

+            else

+            {

+                req.r.rtm_dst_len = 32;

+            }

             break;

         case AF_INET6:

             res.addr_size = sizeof(struct in6_addr);

+            /* kernel can return ::/128 host route */

+            req.r.rtm_dst_len = 128;

             break;

         default: