Modified get_default_gateway code for Linux

to return the route with the smallest metric
if multiple 0.0.0.0/0.0.0.0 entries are present.

git-svn-id: http://svn.openvpn.net/projects/openvpn/branches/BETA21/openvpn@692 e7ae566f-a301-0410-adde-c780ea21d3b5

diff --git a/route.c b/route.c
index 255d35c4225e684136c856231b1bcdf00ad12175..a0ae19bf1ac58196609bb049a9bac874abe3d5a6 100644 (file)
--- a/route.c
+++ b/route.c
@@ -1347,6 +1347,9 @@ get_default_gateway (in_addr_t *ret)
     {
       char line[256];
       int count = 0;
+      int best_count = 0;
+      unsigned int lowest_metric = ~0;
+      in_addr_t best_gw = 0;
       while (fgets (line, sizeof (line), fp) != NULL)
        {
          if (count)
@@ -1354,33 +1357,44 @@ get_default_gateway (in_addr_t *ret)
              unsigned int net_x = 0;
              unsigned int mask_x = 0;
              unsigned int gw_x = 0;
-             const int np = sscanf (line, "%*s\t%x\t%x\t%*s\t%*s\t%*s\t%*s\t%x",
+             unsigned int metric = 0;
+             const int np = sscanf (line, "%*s\t%x\t%x\t%*s\t%*s\t%*s\t%d\t%x",
                                     &net_x,
                                     &gw_x,
+                                    &metric,
                                     &mask_x);
-             if (np == 3)
+             if (np == 4)
                {
                  const in_addr_t net = ntohl (net_x);
                  const in_addr_t mask = ntohl (mask_x);
                  const in_addr_t gw = ntohl (gw_x);
-#if 0
-                 msg (M_INFO, "route %s %s %s",
-                      print_in_addr_t ((in_addr_t) net, 0, &gc),
-                      print_in_addr_t ((in_addr_t) mask, 0, &gc),
-                      print_in_addr_t ((in_addr_t) gw, 0, &gc));
-#endif
-                 if (!net && !mask)
+
+                 dmsg (D_ROUTE_DEBUG, "GDG: route[%d] %s/%s/%s m=%u",
+                       count,
+                       print_in_addr_t ((in_addr_t) net, 0, &gc),
+                       print_in_addr_t ((in_addr_t) mask, 0, &gc),
+                       print_in_addr_t ((in_addr_t) gw, 0, &gc),
+                       metric);
+
+                 if (!net && !mask && metric < lowest_metric)
                    {
-                     fclose (fp);
-                     *ret = gw;
-                     gc_free (&gc);
-                     return true;
+                     best_gw = gw;
+                     lowest_metric = metric;
+                     best_count = count;
                    }
                }
            }
          ++count;
        }
       fclose (fp);
+
+      if (best_gw)
+       *ret = best_gw;
+
+      dmsg (D_ROUTE_DEBUG, "GDG: best=%s[%d] lm=%u",
+           print_in_addr_t ((in_addr_t) best_gw, 0, &gc),
+           best_count,
+           (unsigned int)lowest_metric);
     }
 
   gc_free (&gc);