Merge in multicast changes from trunk ACE 6.1.1 release 3/21/2012 to 4/3/2012

7 files changed, 304 insertions, 210 deletions

diff --git a/ChangeLog b/ChangeLog
index 9249e14d710..b33fd579b99 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,62 @@
+Tue Apr  3 22:49:11 UTC 2012  Steve Huston  <shuston@riverace.com>
+
+        * ace/SOCK_Dgram_Mcast.cpp (subscribe_ifs): Set the error code when
+          a Windows API call fails. Also, when calling GetAdaptersAddresses()
+          to both check size and get the info, supply GAA_FLAG_SKIP_MULTICAST
+          as the flag value. This avoids obtaining info for joined multicast
+          addresses, not multicastable interfaces. Without the flag, and if
+          some other process does a join between the size-check call and the
+          info-gathering call, the size will be wrong.
+
+Wed Mar 28 21:44:20 UTC 2012  Steve Huston  <shuston@riverace.com>
+
+        * tests/Multicast_Test.cpp: Removed the forced set_nic to "lo" for
+          Linux. It's not needed with the changes from:
+          Wed Mar 21 21:57:40 UTC 2012  Steve Huston  <shuston@riverace.com>
+
+Sat Mar 24 21:53:13  UTC 2012  Steve Huston  <shuston@riverace.com>
+
+        * ace/SOCK_Dgram_Mcast.cpp (subscribe_ifs): For Windows, handle IPv6
+          and IPv4 differently. The make_multicast_ifaddr() call that will end
+          up being made for IPv4 wants the interface's IP address, not name.
+
+        * bin/MakeProjectCreator/config/acedefaults.mpb:
+        * bin/MakeProjectCreator/config/ipv6.mpb: Moved the lit_lib for iphlpapi
+          on Windows from the IPv6 base to acedefaults. SOCK_Dgram_Mcast.cpp
+          uses it for both IPv4 and IPv6 now.
+
+Thu Mar 22 16:23:14 UTC 2012  Steve Huston  <shuston@riverace.com>
+
+        * ace/SOCK_Dgram_Mcast.h: Corrected the description of conditions
+          under which using OPT_NULLIFACE_ALL works and neatened things up.
+
+        * tests/Multicast_Test.cpp: Turn on IP_MULTICAST_LOOP all the time.
+          This test requires it and it's not universally the default.
+
+Wed Mar 21 21:57:40 UTC 2012  Steve Huston  <shuston@riverace.com>
+
+        * ace/SOCK_Dgram_Mcast.cpp (subscribe_ifs): Expanded the use of
+          code to scan interfaces to be always, not just for IPv6, when
+          subscribing with OPT_NULLIFACE_ALL and no specific interface.
+          Also replaced use of ACE_OS::if_nameindex with getifaddr() when
+          it's available (which was only on Linux anyway) so checks
+          for interface up and multicastable can be made before joining.
+          The code now works for systems with ACE_HAS_GETIFDADDR (incl.
+          Linux, which was my main issue driving this) and Win32. The others
+          end up in the old get_ip_interfaces code which will never work
+          anywhere as far as I can tell because it tries to subscribe to an
+          interface named with the IP address in string form.
+
+        * tests/Multicast_Test.cpp: Removed hack force of interface "lo0"
+          on join(). No need for that with the fix above. For background, this
+          was added at:
+          Thu Jan 21 15:25:30 UTC 2010  Martin Corino  <mcorino@remedy.nl>
+
+        * ace/Sock_Connect.cpp (get_ip_interfaces_getifaddr): Will no longer
+          return an interface marked 'down'. Partially fixes Bugzilla #1990
+          but other platform-specific changes are needed to resolve it
+          completely.
+
 Wed Mar 07 09:04:40 CET 2012  Johnny Willemsen  <jwillemsen@remedy.nl>
 
         * ACE version 6.1.0 released.
diff --git a/ace/SOCK_Dgram_Mcast.cpp b/ace/SOCK_Dgram_Mcast.cpp
index abac401f790..a5d5e5e0c16 100644
--- a/ace/SOCK_Dgram_Mcast.cpp
+++ b/ace/SOCK_Dgram_Mcast.cpp
@@ -12,10 +12,18 @@
 #include "ace/OS_NS_sys_socket.h"
 #endif
 
-#if defined (ACE_HAS_IPV6) && defined (ACE_WIN32)
+#if defined (ACE_WIN32)
 #include /**/ <iphlpapi.h>
 #endif
 
+#if defined (ACE_HAS_GETIFADDRS)
+#  if defined (ACE_VXWORKS)
+#    include /**/ <net/ifaddrs.h>
+#  else
+#    include /**/ <ifaddrs.h>
+#  endif /*ACE_VXWORKS */
+#endif /* ACE_HAS_GETIFADDRS */
+
 #if !defined (__ACE_INLINE__)
 #include "ace/SOCK_Dgram_Mcast.inl"
 #endif /* __ACE_INLINE__ */
@@ -253,135 +261,135 @@ ACE_SOCK_Dgram_Mcast::subscribe_ifs (const ACE_INET_Addr &mcast_addr,
   if (ACE_BIT_ENABLED (this->opts_, OPT_NULLIFACE_ALL)
       && net_if == 0)
     {
-#if defined (ACE_HAS_IPV6)
-      if (mcast_addr.get_type () == AF_INET6)
-        {
-          size_t nr_subscribed = 0;
-# if defined(ACE_LINUX)
-          struct if_nameindex *intf = 0;
-
-          intf = ACE_OS::if_nameindex ();
-
-          if (intf == 0)
-            return -1;
-
-          int index = 0;
-          while (intf[index].if_index != 0 || intf[index].if_name != 0)
-            {
-              if (this->join (mcast_addr, reuse_addr,
-                              ACE_TEXT_CHAR_TO_TCHAR(intf[index].if_name)) == 0)
-                ++nr_subscribed;
-
-              ++index;
-            }
+      int family = mcast_addr.get_type ();
+      size_t nr_subscribed = 0;
 
-          ACE_OS::if_freenameindex (intf);
+#if defined (ACE_HAS_GETIFADDRS)
 
-# elif defined (ACE_WIN32)
+      // Take advantage of the BSD getifaddrs function that simplifies
+      // access to connected interfaces.
+      struct ifaddrs *ifap = 0;
+      struct ifaddrs *p_if = 0;
 
-          IP_ADAPTER_ADDRESSES tmp_addrs;
-          // Initial call to determine actual memory size needed
-          DWORD dwRetVal;
-          ULONG bufLen = 0;
-          if ((dwRetVal = ::GetAdaptersAddresses (AF_INET6,
-                                                  0,
-                                                  0,
-                                                  &tmp_addrs,
-                                                  &bufLen)) != ERROR_BUFFER_OVERFLOW)
-            return -1; // With output bufferlength 0 this can't be right.
+      if (::getifaddrs (&ifap) != 0)
+        return -1;
 
-          // Get required output buffer and retrieve info for real.
-          PIP_ADAPTER_ADDRESSES pAddrs;
-          char *buf;
-          ACE_NEW_RETURN (buf,
-                          char[bufLen],
-                          -1);
-          pAddrs = reinterpret_cast<PIP_ADAPTER_ADDRESSES> (buf);
-          if ((dwRetVal = ::GetAdaptersAddresses (AF_INET6,
-                                                  0,
-                                                  0,
-                                                  pAddrs,
-                                                  &bufLen)) != NO_ERROR)
+      // Not every interface is for IP, and not all are up and multicast.
+      for (p_if = ifap;
+           p_if != 0;
+           p_if = p_if->ifa_next)
+        {
+          // Some OSes can return interfaces with no ifa_addr if the
+          // interface has no assigned address.
+          // If there is an address but it's not the family we want, ignore it.
+          if (p_if->ifa_addr == 0 || p_if->ifa_addr->sa_family != family)
+            continue;
+
+          // Check to see if it's up and supports multicast.
+          unsigned int wanted = IFF_UP | IFF_MULTICAST;
+          if ((p_if->ifa_flags & wanted) != wanted)
+            continue;
+
+          // Sometimes the kernel returns 0.0.0.0 as the interface
+          // address, skip those...
+          if (p_if->ifa_addr->sa_family == PF_INET)
             {
-              delete[] buf; // clean up
-              return -1;
-            }
+              struct sockaddr_in *addr =
+                reinterpret_cast<sockaddr_in *> (p_if->ifa_addr);
 
-          while (pAddrs)
+              if (addr->sin_addr.s_addr == INADDR_ANY)
+                continue;
+            }
+#  if defined (ACE_HAS_IPV6)
+          else if (p_if->ifa_addr->sa_family == AF_INET6)
             {
-              if (this->join (mcast_addr, reuse_addr,
-                              ACE_TEXT_CHAR_TO_TCHAR(pAddrs->AdapterName)) == 0)
-                ++nr_subscribed;
+              struct sockaddr_in6 *addr =
+                reinterpret_cast<sockaddr_in6 *> (p_if->ifa_addr);
 
-              pAddrs = pAddrs->Next;
+              // Skip the ANY address
+              if (IN6_IS_ADDR_UNSPECIFIED(&addr->sin6_addr))
+                continue;
             }
+#  endif /* ACE_HAS_IPV6 */
 
-          delete[] buf; // clean up
+          // Ok, now join on this interface.
+          if (this->join (mcast_addr,
+                          reuse_addr,
+                          ACE_TEXT_CHAR_TO_TCHAR(p_if->ifa_name)) == 0)
+            ++nr_subscribed;
+        }
 
-# endif /* ACE_WIN32 */
+      ::freeifaddrs (ifap);
 
-          if (nr_subscribed == 0)
-            {
-              errno = ENODEV;
-              return -1;
-            }
+# elif defined (ACE_WIN32)
 
-          return 1;
-        }
-      else
+      IP_ADAPTER_ADDRESSES tmp_addrs;
+      // Initial call to determine actual memory size needed
+      DWORD dwRetVal;
+      ULONG bufLen = 0;
+      // Note... GetAdaptersAddresses returns different bufLen values depending
+      // on how many multicast joins there are on the system. To avoid this,
+      // specify that we don't want to know about multicast addresses. This
+      // does not avoid multicastable interfaces and makes the size-check
+      // more reliable across varying conditions.
+      DWORD flags = GAA_FLAG_SKIP_MULTICAST;
+      if ((dwRetVal = ::GetAdaptersAddresses (family,
+                                              flags,
+                                              0,
+                                              &tmp_addrs,
+                                              &bufLen)) != ERROR_BUFFER_OVERFLOW)
         {
-          // Subscribe on all local multicast-capable network interfaces, by
-          // doing recursive calls with specific interfaces.
-
-          ACE_INET_Addr *if_addrs = 0;
-          size_t if_cnt;
+          errno = dwRetVal;
+          return -1; // With output bufferlength 0 this can't be right.
+        }
 
-          if (ACE::get_ip_interfaces (if_cnt, if_addrs) != 0)
-            return -1;
+      // Get required output buffer and retrieve info for real.
+      PIP_ADAPTER_ADDRESSES pAddrs;
+      char *buf;
+      ACE_NEW_RETURN (buf,
+                      char[bufLen],
+                      -1);
+      pAddrs = reinterpret_cast<PIP_ADAPTER_ADDRESSES> (buf);
+      if ((dwRetVal = ::GetAdaptersAddresses (family,
+                                              flags,
+                                              0,
+                                              pAddrs,
+                                              &bufLen)) != NO_ERROR)
+        {
+          delete[] buf; // clean up
+          errno = dwRetVal;
+          return -1;
+        }
 
-          size_t nr_subscribed = 0;
+      for (; pAddrs; pAddrs = pAddrs->Next)
+        {
+          if (pAddrs->OperStatus != IfOperStatusUp)
+            continue;
 
-          if (if_cnt < 2)
+          // The ACE_SOCK_Dgram::make_multicast_ifaddr (IPv4), called by join(),
+          // can only deal with a dotted-decimal address, not an interface name.
+          if (family == AF_INET)
             {
-              if (this->join (mcast_addr,
-                              reuse_addr,
-                              ACE_TEXT ("0.0.0.0")) == 0)
+              ACE_INET_Addr intf_addr ((sockaddr_in*)(pAddrs->FirstUnicastAddress->Address.lpSockaddr),
+                                       pAddrs->FirstUnicastAddress->Address.iSockaddrLength);
+              char intf_addr_str[INET_ADDRSTRLEN];
+              intf_addr.get_host_addr (intf_addr_str, sizeof (intf_addr_str));
+              if (this->join (mcast_addr, reuse_addr,
+                              ACE_TEXT_CHAR_TO_TCHAR(intf_addr_str)) == 0)
                 ++nr_subscribed;
             }
           else
             {
-              // Iterate through all the interfaces, figure out which ones
-              // offer multicast service, and subscribe to them.
-              while (if_cnt > 0)
-                {
-                  --if_cnt;
-
-                  // Convert to 0-based for indexing, next loop check.
-                  if (if_addrs[if_cnt].get_type () != AF_INET || if_addrs[if_cnt].is_loopback ())
-                    continue;
-                  char addr_buf[INET6_ADDRSTRLEN];
-                  if (this->join (mcast_addr,
-                                  reuse_addr,
-                                  ACE_TEXT_CHAR_TO_TCHAR
-                                   (if_addrs[if_cnt].get_host_addr (addr_buf, INET6_ADDRSTRLEN))) == 0)
-                    ++nr_subscribed;
-                }
+              if (this->join (mcast_addr, reuse_addr,
+                              ACE_TEXT_CHAR_TO_TCHAR(pAddrs->AdapterName)) == 0)
+                ++nr_subscribed;
             }
+        }
 
-          delete [] if_addrs;
+      delete[] buf; // clean up
 
-          if (nr_subscribed == 0)
-            {
-              errno = ENODEV;
-              return -1;
-            }
+# else
 
-          // 1 indicates a "short-circuit" return.  This handles the
-          // recursive behavior of checking all the interfaces.
-          return 1;
-
-        }
-#else
       // Subscribe on all local multicast-capable network interfaces, by
       // doing recursive calls with specific interfaces.
 
@@ -391,8 +399,6 @@ ACE_SOCK_Dgram_Mcast::subscribe_ifs (const ACE_INET_Addr &mcast_addr,
       if (ACE::get_ip_interfaces (if_cnt, if_addrs) != 0)
         return -1;
 
-      size_t nr_subscribed = 0;
-
       if (if_cnt < 2)
         {
           if (this->join (mcast_addr,
@@ -409,7 +415,7 @@ ACE_SOCK_Dgram_Mcast::subscribe_ifs (const ACE_INET_Addr &mcast_addr,
               --if_cnt;
 
               // Convert to 0-based for indexing, next loop check.
-              if (if_addrs[if_cnt].is_loopback ())
+              if (if_addrs[if_cnt].get_type () != family || if_addrs[if_cnt].is_loopback ())
                 continue;
               char addr_buf[INET6_ADDRSTRLEN];
               if (this->join (mcast_addr,
@@ -422,18 +428,19 @@ ACE_SOCK_Dgram_Mcast::subscribe_ifs (const ACE_INET_Addr &mcast_addr,
 
       delete [] if_addrs;
 
+# endif /* ACE_WIN32 */
+
       if (nr_subscribed == 0)
         {
           errno = ENODEV;
           return -1;
         }
 
-      // 1 indicates a "short-circuit" return.  This handles the
-      // recursive behavior of checking all the interfaces.
       return 1;
-#endif /* ACE_HAS_IPV6 */
     }
 
+  // Subscribe on a specific interface, or on the default interface.
+
 #if defined (ACE_HAS_IPV6)
   if (mcast_addr.get_type () == AF_INET6)
     {
@@ -441,6 +448,7 @@ ACE_SOCK_Dgram_Mcast::subscribe_ifs (const ACE_INET_Addr &mcast_addr,
         return -1;
     }
   else
+#endif /* ACE_HAS_IPV6 - Fall into IPv4-only case */
     {
       // Validate passed multicast addr and iface specifications.
       if (this->make_multicast_ifaddr (0,
@@ -448,13 +456,6 @@ ACE_SOCK_Dgram_Mcast::subscribe_ifs (const ACE_INET_Addr &mcast_addr,
                                        net_if) == -1)
         return -1;
     }
-#else
-    // Validate passed multicast addr and iface specifications.
-    if (this->make_multicast_ifaddr (0,
-                                     mcast_addr,
-                                     net_if) == -1)
-      return -1;
-#endif /* ACE_HAS_IPV6 */
 
   return 0;
 
diff --git a/ace/SOCK_Dgram_Mcast.h b/ace/SOCK_Dgram_Mcast.h
index 6f3c3bc5b62..a2e54969d39 100644
--- a/ace/SOCK_Dgram_Mcast.h
+++ b/ace/SOCK_Dgram_Mcast.h
@@ -46,50 +46,56 @@ ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  *
  * Supports multiple simultaneous subscriptions, unsubscription from one or
  * all subscriptions, and independent send/recv address and interface
- * specifications.  Template parameters and/or ctor arguments determine
- * per-instance optional functionality.
+ * specifications.  Constructor arguments determine per-instance optional
+ * functionality.
  *
- * Note that multicast semantics and implementation details are _very_
+ * Note that multicast semantics and implementation details are @i very
  * environment-specific; this class is just a wrapper around the underlying
  * implementation and does not try to normalize the concept of multicast
  * communications.
  *
  * Usage Notes:
- * - Send and Recv addresses and network interfaces, but not port#, are
- *   independent.  While this instance is open, 1 send interface (and a default
- *   send address) is in effect and 0, 1, or multiple recv addresses/interfaces
- *   are in effect.
+ * - Send and receive addresses and network interfaces, but not port number,
+ *   are independent. While this instance is open, one send interface (and a
+ *   default send address) is in effect and 0, 1, or multiple receive
+ *   addresses/interfaces are in effect.
  * - The first open()/subscribe() invocation defines the network interface
  *   and default address used for all sends by this instance, defines the
- *   port# and optionally the multicast address bound to the underlying
- *   socket, and defines the (one) port# that is used for all subscribes
- *   (subsequent subscribes must pass the same port# or '0').
+ *   port number and optionally the multicast address bound to the underlying
+ *   socket, and defines the (one) port number that is used for all subscribes
+ *   (subsequent subscribes must pass the same port number or 0).
  * - The default loopback state is not explicitly set; the environment will
- *   determine the default state.  Note that some environments (e.g. some Win32)
- *   do not allow the default to be changed, and that the semantics of
- *   loopback control are environment dependent (e.g. sender vs receiver
- *   control).
+ *   determine the default state.  Note that some environments (e.g. some
+ *   Windows versions) do not allow the default to be changed, and that the
+ *   semantics of loopback control are environment dependent (e.g. sender vs.
+ *   receiver control).
  * - In general, due to multicast design and implementation quirks/bugs, it is
  *   difficult to tell which address a received message was sent to or which
  *   interface it was received on (even if only one subscription is active).
- *   However; there are filtering options that can be applied, to narrow it
+ *   However, there are filtering options that can be applied, to narrow it
  *   down considerably.
  *
  * Interface specification notes (for subscribe() and unsubscribe()):
- * - If net_if == 0, the null_iface_opt option determines whether only the
- *   system "default" interface or all interfaces is affected.  Specifying
- *   "all" interfaces is supported only for environments for which
- *   ACE_Sock_Connect::get_ip_interfaces() is properly implemented.
+ * - If @a net_if == 0, the @c OPT_NULLIFACE_ALL and @c OPT_NULLIFACE_ONE
+ *   options determine whether only the system default interface
+ *   (if @c OPT_NULLIFACE_ONE is set) or all interfaces (if
+ *   @c OPT_NULLIFACE_ALL is set) is affected.  Specifying all interfaces
+ *   functions correctly only on:
+ *      + Windows
+ *      + Platforms with the ACE_HAS_GETIFADDRS config setting (includes Linux)
+ *      + Platforms which accept the IP address as an interface
+ *        name/specification
+ *      + Systems with only one non-loopback interface.
+ *   Other platforms require additional supporting code.
  * - Multiple subscriptions for the same address but different interfaces is
  *   normally supported, but re-subscription to an address/interface that is
  *   already subscribed is normally not allowed.
- * - The <net_if> interface specification syntax is environment-specific.
+ * - The @a net_if interface specification syntax is environment-specific.
  *   UNIX systems will normally use device specifications such as "le0" or
  *   "elxl1", while other systems will use the IP address of the interface.
  *   Some platforms, such as pSoS, support only cardinal numbers as network
  *   interface specifications; for these platforms, just give these numbers in
- *   alphanumeric form and <subscribe> will convert them into numbers via
- *   ACE_OS::atoi().
+ *   string form and join() will convert them into numbers.
  */
 class ACE_Export ACE_SOCK_Dgram_Mcast : public ACE_SOCK_Dgram
 {
@@ -99,28 +105,30 @@ public:
    * @brief Option parameters.
    *
    * These control per-instance optional functionality.  They are set via
-   * optional constructor arguments.
+   * an optional constructor argument.
+   *
    * @note Certain option values are not valid for all environments (see
    * comments in source file for environment-specific restrictions).  Default
    * values are always valid values for the compilation environment.
    */
   enum options
   {
-  // Define whether a specific (multicast) address (in addition to the port#)
-  // is bound to the socket.
-  // Notes:
-  // - Effect of doing this is stack/environment dependent, but in most
-  //   environments can be used to filter out unwanted unicast, broadcast, and
-  //   (other) multicast messages sent to the same port#.
-  // - Some IP stacks (e.g. some Win32) do not support binding multicast
-  //   addresses.  Using this option will always cause an <open> error.
-  // - It's not strictly possible for user code to do this level of filtering
-  //   w/out the bind; some environments support ways to determine which address
-  //   a message was sent _to_, but this class interface does not support access
-  //   to that info.
-  // - The address (and port#) passed to <open> (or the first <subscribe>, if
-  //   <open> is not explicitly invoked) is the one that is bound.
-  //
+    /* Define whether a specific multicast address (in addition to the port
+     * number) is bound to the socket.
+     * @note:
+     * - Effect of doing this is stack/environment dependent, but in most
+     *   environments can be used to filter out unwanted unicast, broadcast,
+     *   and (other) multicast messages sent to the same port number.
+     * - Some IP stacks (e.g. some Windows) do not support binding multicast
+     *   addresses.  Using this option will always cause an open() error.
+     * - It's not strictly possible for user code to do this level of filtering
+     *   without the bind; some environments support ways to determine which
+     *   address a message was sent to, but this class interface does not
+     *   support access to that information.
+     * - The address (and port number) passed to open() (or the first
+     *   join(), if open() is not explicitly invoked) is the one that is bound.
+     */
+
     /// Disable address bind. (Bind only port.)
     /// @note This might seem odd, but we need a way to distinguish between
     /// default behavior, which might or might not be to bind, and explicitly
@@ -142,20 +150,28 @@ public:
       DEFOPT_BINDADDR  = OPT_BINDADDR_NO,
 #endif /* ACE_LACKS_PERFECT_MULTICAST_FILTERING = 1) */
 
-  /// Define the interpretation of 'NULL' as a recv interface specification.
-  /// If the interface part of a multicast address specification is NULL, it
-  /// will be interpreted to mean either "the default interface" or "all
-  /// interfaces", depending on the setting of this option.
-  /// Notes:
-  /// - The 'nulliface_all' option can not be used in environments which do
-  ///   not fully support the ACE_Sock_Connect::get_ip_interfaces() method
-  ///   (e.g. non-Windows).
-  ///   If it is, using NULL for iface will _always_ fail.
-  /// - The default behavior in most IP stacks is to use the 'default' interface,
-  ///   where 'default' has rather ad-hoc semantics.
-  /// - This applies only to receives, not sends (which always use only one
-  ///   interface; NULL means use the "system default" interface).
-  /// Supported values:
+    /*
+     * Define the interpretation of NULL as a join interface specification.
+     * If the interface part of a multicast address specification is NULL, it
+     * will be interpreted to mean either "the default interface" or "all
+     * interfaces", depending on the setting of this option.
+     * @note
+     * - The @c OPT_NULLIFACE_ALL option can be used only in the following
+     *   environments:
+     *      + Windows
+     *      + Platforms with the ACE_HAS_GETIFADDRS config setting (includes
+     *        Linux)
+     *      + Platforms which accept the IP address as an interface
+     *        name/specification and for which
+     *        ACE_Sock_Connect::get_ip_interfaces() is fully implemented
+     *      + Systems with only one non-loopback interface.
+     *   Other platforms require additional supporting code.
+     * - The default behavior in most IP stacks is to use the default
+     *   interface where "default" has rather ad-hoc semantics.
+     * - This applies only to receives, not sends (which always use only one
+     *   interface; NULL means use the "system default" interface).
+     */
+    /// Supported values:
     /// If (net_if==NULL), use default interface.
     /// @note This might seem odd, but we need a way to distinguish between
     /// default behavior, which might or might not be to bind, and explicitly
@@ -179,15 +195,15 @@ public:
 
   // = Initialization routines.
 
-  /// Ctor - Create an unitialized instance and define per-instance optional
+  /// Create an unitialized instance and define per-instance optional
   /// functionality.
   /**
-   * You must invoke open() or subscribe(), to create/bind a socket and define
+   * You must invoke open() or join(), to create/bind a socket and define
    * operational parameters, before performing any I/O with this instance.
    */
   ACE_SOCK_Dgram_Mcast (options opts = DEFOPTS);
 
-  /// Dtor - Release all resources and implicitly or explicitly unsubscribe
+  /// Release all resources and implicitly or explicitly unsubscribe
   /// from all currently subscribed groups.
   /**
    * The OPT_DTORUNSUB_YES_ option defines whether an explicit unsubscribe() is
@@ -196,31 +212,36 @@ public:
    */
   ~ACE_SOCK_Dgram_Mcast (void);
 
-  /// Explicitly open/bind the socket and define the network interface
-  /// and default multicast address used for sending messages.
   /**
+   * Explicitly open/bind the socket and define the network interface
+   * and default multicast address used for sending messages.
+   *
    * This method is optional; if not explicitly invoked, it is invoked by
-   * the first subscribe(), using the subscribed address/port# and network
+   * the first join(), using the subscribed address/port number and network
    * interface parameters.
-   * The @a mcast_addr parameter defines the default send address/port# and
-   * also the port# and, if the OPT_BINDADDR_YES option is used,
-   * the multicast address that is bound to this socket.
-   * If the @a net_if parameter != 0, it defines the network interface
-   * used for all sends by this instance, otherwise the system "default"
-   * interface is used. (The @a net_if parameter is ignored if this
-   * feature is not supported by the environment.)
-   * The port# in @a mcast_addr may be 0, in which case a system-assigned
-   * (ephemeral) port# is used for sending and receiving.
-   * If @a reuse_addr != 0, the SO_REUSEADDR option and, if it is supported,
-   * the SO_REUSEPORT option are enabled.
    *
-   * Returns: -1 if the call fails.  Failure can occur due to problems with
-   * the address, port#, and/or interface parameters or during system open()
+   * @param mcast_addr  Defines the default send address/port number and,
+   *        if the @c OPT_BINDADDR_YES option is used, the multicast address
+   *        that is bound to this socket. The port number in @a mcast_addr
+   *        may be 0, in which case a system-assigned (ephemeral) port number
+   *        is used for sending and receiving.
+   *
+   * @param net_if  If @a net_if is not 0, it defines the network interface
+   *        used for all sends by this instance, otherwise the system default
+   *        interface is used. (The @a net_if parameter is ignored if this
+   *        feature is not supported by the environment.)
+   *
+   * @param reuse_addr  If @a reuse_addr is not 0, the @c SO_REUSEADDR option
+   *        and, if it is supported, the SO_REUSEPORT option are enabled.
+   *
+   * @retval 0 on success
+   * @retval -1 if the call fails. Failure can occur due to problems with
+   * the address, port, and/or interface parameters or during system open()
    * or socket option processing.
    */
-  int open (const ACE_INET_Addr &mcast_addr,        // Bound & sendto address.
-            const ACE_TCHAR *net_if = 0,            // Net interface for sends.
-            int reuse_addr = 1);                    // Reuse addr/port sock opt.
+  int open (const ACE_INET_Addr &mcast_addr,
+            const ACE_TCHAR *net_if = 0,
+            int reuse_addr = 1);
 
   // = Multicast group subscribe/unsubscribe routines.
 
diff --git a/ace/Sock_Connect.cpp b/ace/Sock_Connect.cpp
index 332b21bb69e..8973534b202 100644
--- a/ace/Sock_Connect.cpp
+++ b/ace/Sock_Connect.cpp
@@ -777,8 +777,14 @@ get_ip_interfaces_getifaddrs (size_t &count,
        p_if != 0;
        p_if = p_if->ifa_next)
     {
-      if (p_if->ifa_addr &&
-          p_if->ifa_addr->sa_family == AF_INET)
+      if (p_if->ifa_addr == 0)
+        continue;
+
+      // Check to see if it's up.
+      if ((p_if->ifa_flags & IFF_UP) != IFF_UP)
+        continue;
+
+      if (p_if->ifa_addr->sa_family == AF_INET)
         {
           struct sockaddr_in *addr =
             reinterpret_cast<sockaddr_in *> (p_if->ifa_addr);
@@ -794,8 +800,7 @@ get_ip_interfaces_getifaddrs (size_t &count,
             }
         }
 # if defined (ACE_HAS_IPV6)
-      else if (p_if->ifa_addr &&
-               p_if->ifa_addr->sa_family == AF_INET6)
+      else if (p_if->ifa_addr->sa_family == AF_INET6)
         {
           struct sockaddr_in6 *addr =
             reinterpret_cast<sockaddr_in6 *> (p_if->ifa_addr);
diff --git a/bin/MakeProjectCreator/config/acedefaults.mpb b/bin/MakeProjectCreator/config/acedefaults.mpb
index 7c7cff5c75c..6798ba1ea52 100644
--- a/bin/MakeProjectCreator/config/acedefaults.mpb
+++ b/bin/MakeProjectCreator/config/acedefaults.mpb
@@ -17,6 +17,10 @@ project: ipv6, vc_warnings, build_files, test_files, svc_conf_files, ace_unicode
     macro_for_lib_modifier=1
   }
 
+  specific(prop:windows) {
+    lit_libs += iphlpapi
+  }
+
   specific(cdt6) {
     win32::platform_libs += ws2_32 mswsock netapi32
     release::macros += ACE_NDEBUG ACE_USE_RCSID=0
diff --git a/bin/MakeProjectCreator/config/ipv6.mpb b/bin/MakeProjectCreator/config/ipv6.mpb
index 92473ad7113..b76821b80d1 100644
--- a/bin/MakeProjectCreator/config/ipv6.mpb
+++ b/bin/MakeProjectCreator/config/ipv6.mpb
@@ -2,9 +2,5 @@
 // $Id$
 
 feature(ipv6) {
-  specific(prop:windows) {
-    lit_libs += iphlpapi
-  }
-
   macros += ACE_HAS_IPV6
 }
diff --git a/tests/Multicast_Test.cpp b/tests/Multicast_Test.cpp
index 5d1d8109f12..a053676b1c2 100644
--- a/tests/Multicast_Test.cpp
+++ b/tests/Multicast_Test.cpp
@@ -448,19 +448,11 @@ public:
                       = ACE_SOCK_Dgram_Mcast::DEFOPTS);
   virtual ~MCT_Event_Handler (void);
 
-#if defined (ACE_LINUX)
-  int join (const ACE_INET_Addr &mcast_addr,
-            int reuse_addr = 1,
-            const ACE_TCHAR *net_if = ACE_TEXT ("lo"));
-  int leave (const ACE_INET_Addr &mcast_addr,
-             const ACE_TCHAR *net_if = ACE_TEXT ("lo"));
-#else
   int join (const ACE_INET_Addr &mcast_addr,
             int reuse_addr = 1,
             const ACE_TCHAR *net_if = 0);
   int leave (const ACE_INET_Addr &mcast_addr,
              const ACE_TCHAR *net_if = 0);
-#endif
 
   // = Event Handler hooks.
   virtual int handle_input (ACE_HANDLE handle);
@@ -468,6 +460,9 @@ public:
 
   virtual ACE_HANDLE get_handle (void) const;
 
+  // Turn loopback on/off. Must be called after at least 1 join() is performed.
+  int loopback (bool on_off);
+
 protected:
   ACE_SOCK_Dgram_Mcast *mcast (void);
   int find (const char *buf);
@@ -641,6 +636,14 @@ MCT_Event_Handler::get_handle (void) const
   return this->mcast_.get_handle ();
 }
 
+// Turn loopback on/off
+int
+MCT_Event_Handler::loopback (bool on_off)
+{
+  char loopback_on = on_off ? 1 : 0;
+  return this->mcast_.set_option (IP_MULTICAST_LOOP, loopback_on);
+}
+
 /******************************************************************************/
 
 /*
@@ -721,6 +724,13 @@ MCT_Task::open (void *)
 
       advance_addr (addr);
 
+      // This test needs loopback because we're both sending and receiving.
+      // Loopback is usually the default, but be sure.
+      if (-1 == handler->loopback (true))
+        ACE_ERROR ((LM_WARNING,
+                    ACE_TEXT ("%p\n"),
+                    ACE_TEXT ("MCT_Task::open - enable loopback")));
+
       if (this->reactor ()->register_handler (handler, READ_MASK) == -1)
         ACE_ERROR_RETURN ((LM_ERROR,
                            ACE_TEXT ("MCT_Task::open - cannot register ")
@@ -787,9 +797,7 @@ int producer (MCT_Config &config)
   ACE_DEBUG ((LM_INFO, ACE_TEXT ("Starting producer...\n")));
   ACE_SOCK_Dgram socket (ACE_sap_any_cast (ACE_INET_Addr &), PF_INET);
   //FUZZ: enable check_for_lack_ACE_OS
-#if defined (ACE_LINUX)
-  socket.set_nic (ACE_TEXT("lo"));
-#endif
+
   // Note that is is IPv4 specific and needs to be changed once
   //
   if (config.ttl () > 1)