src/java.base/macosx/classes/java/net/DefaultInterface.java

rev 16951 : [mq]: defaultInterface

*** 48,61 ****
      static NetworkInterface getDefault() {
          return defaultInterface;
      }
  
      /**
!      * Choose a default interface. This method returns an interface that is
!      * both "up" and supports multicast. This method choses an interface in
       * order of preference:
       * 1. neither loopback nor point to point
       * 2. point to point
       * 3. loopback
       *
       * @return  the chosen interface or {@code null} if there isn't a suitable
       *          default
--- 48,62 ----
      static NetworkInterface getDefault() {
          return defaultInterface;
      }
  
      /**
!      * Choose a default interface. This method returns the first interface that
!      * is both "up" and supports multicast. This method chooses an interface in
       * order of preference:
       * 1. neither loopback nor point to point
+      *    ( prefer interfaces with dual IP support )
       * 2. point to point
       * 3. loopback
       *
       * @return  the chosen interface or {@code null} if there isn't a suitable
       *          default
*** 64,97 ****
          Enumeration<NetworkInterface> nifs;
  
          try {
             nifs = NetworkInterface.getNetworkInterfaces();
          } catch (IOException ignore) {
!             // unable to enumate network interfaces
              return null;
          }
  
          NetworkInterface ppp = null;
          NetworkInterface loopback = null;
  
          while (nifs.hasMoreElements()) {
              NetworkInterface ni = nifs.nextElement();
              try {
!                 if (ni.isUp() && ni.supportsMulticast()) {
                      boolean isLoopback = ni.isLoopback();
                      boolean isPPP = ni.isPointToPoint();
                      if (!isLoopback && !isPPP) {
                          // found an interface that is not the loopback or a
                          // point-to-point interface
                          return ni;
                      }
                      if (ppp == null && isPPP)
                          ppp = ni;
                      if (loopback == null && isLoopback)
                          loopback = ni;
!                 }
              } catch (IOException skip) { }
          }
  
          return (ppp != null) ? ppp : loopback;
      }
  }
--- 65,122 ----
          Enumeration<NetworkInterface> nifs;
  
          try {
             nifs = NetworkInterface.getNetworkInterfaces();
          } catch (IOException ignore) {
!             // unable to enumerate network interfaces
              return null;
          }
  
+         NetworkInterface preferred = null;
          NetworkInterface ppp = null;
          NetworkInterface loopback = null;
  
          while (nifs.hasMoreElements()) {
              NetworkInterface ni = nifs.nextElement();
              try {
!                 if (!ni.isUp() || !ni.supportsMulticast())
!                     continue;
! 
!                 boolean ip4 = false, ip6 = false;
!                 Enumeration<InetAddress> addrs = ni.getInetAddresses();
!                 while (addrs.hasMoreElements()) {
!                     InetAddress addr = addrs.nextElement();
!                     if (!addr.isAnyLocalAddress()) {
!                         if (addr instanceof Inet4Address) {
!                             ip4 = true;
!                         } else if (addr instanceof Inet6Address) {
!                             ip6 = true;
!                         }
!                     }
!                 }
! 
                  boolean isLoopback = ni.isLoopback();
                  boolean isPPP = ni.isPointToPoint();
                  if (!isLoopback && !isPPP) {
                      // found an interface that is not the loopback or a
                      // point-to-point interface
+                     if (preferred == null) {
+                         preferred = ni;
+                     } else if (ip4 == true && ip6 == true){
                          return ni;
                      }
+                 }
                  if (ppp == null && isPPP)
                      ppp = ni;
                  if (loopback == null && isLoopback)
                      loopback = ni;
! 
              } catch (IOException skip) { }
          }
  
+         if (preferred != null) {
+             return preferred;
+         } else {
              return (ppp != null) ? ppp : loopback;
          }
+     }
  }