Problem: no way to check if ziflist interface has IPv6

Solution: add a new (draft) ziflist_is_ipv6 API that returns
true/false.

api/ziflist.api

@@ -65,4 +65,9 @@
     <method name = "reload ipv6" state = "draft">
         Reload network interfaces from system, including IPv6
     </method>
+
+    <method name = "is ipv6" state = "draft">
+        Return true if the current interface uses IPv6
+        <return type = "boolean" />
+    </method>
 </class>

bindings/jni/src/main/c/org_zeromq_czmq_Ziflist.c

@@ -97,6 +97,13 @@ Java_org_zeromq_czmq_Ziflist__1_1reloadIpv6 (JNIEnv *env, jclass c, jlong self)
     ziflist_reload_ipv6 ((ziflist_t *) (intptr_t) self);
 }
 
+JNIEXPORT jboolean JNICALL
+Java_org_zeromq_czmq_Ziflist__1_1isIpv6 (JNIEnv *env, jclass c, jlong self)
+{
+    jboolean is_ipv6_ = (jboolean) ziflist_is_ipv6 ((ziflist_t *) (intptr_t) self);
+    return is_ipv6_;
+}
+
 JNIEXPORT void JNICALL
 Java_org_zeromq_czmq_Ziflist__1_1test (JNIEnv *env, jclass c, jboolean verbose)
 {

bindings/jni/src/main/java/org/zeromq/czmq/Ziflist.java

@@ -108,6 +108,13 @@ public void reloadIpv6 () {
         __reloadIpv6 (self);
     }
     /*
+    Return true if the current interface uses IPv6
+    */
+    native static boolean __isIpv6 (long self);
+    public boolean isIpv6 () {
+        return __isIpv6 (self);
+    }
+    /*
     Self test of this class.
     */
     native static void __test (boolean verbose);

bindings/lua_ffi/czmq_ffi.lua

@@ -1477,6 +1477,10 @@ ziflist_t *
 void
     ziflist_reload_ipv6 (ziflist_t *self);
 
+// Return true if the current interface uses IPv6
+bool
+    ziflist_is_ipv6 (ziflist_t *self);
+
 // Self test of this class.
 void
     ziflist_test (bool verbose);

bindings/nodejs/README.md

@@ -1545,6 +1545,12 @@ nothing my_ziflist.reloadIpv6 ()
 
 Reload network interfaces from system, including IPv6
 
+```
+boolean my_ziflist.isIpv6 ()
+```
+
+Return true if the current interface uses IPv6
+
 ```
 nothing my_ziflist.test (Boolean)
 ```

bindings/nodejs/binding.cc

@@ -2839,6 +2839,7 @@ NAN_MODULE_INIT (Ziflist::Init) {
     Nan::SetPrototypeMethod (tpl, "print", _print);
     Nan::SetPrototypeMethod (tpl, "newIpv6", _new_ipv6);
     Nan::SetPrototypeMethod (tpl, "reloadIpv6", _reload_ipv6);
+    Nan::SetPrototypeMethod (tpl, "isIpv6", _is_ipv6);
     Nan::SetPrototypeMethod (tpl, "test", _test);
 
     constructor ().Reset (Nan::GetFunction (tpl).ToLocalChecked ());
@@ -2939,6 +2940,12 @@ NAN_METHOD (Ziflist::_reload_ipv6) {
     ziflist_reload_ipv6 (ziflist->self);
 }
 
+NAN_METHOD (Ziflist::_is_ipv6) {
+    Ziflist *ziflist = Nan::ObjectWrap::Unwrap <Ziflist> (info.Holder ());
+    bool result = ziflist_is_ipv6 (ziflist->self);
+    info.GetReturnValue ().Set (Nan::New<Boolean>(result));
+}
+
 NAN_METHOD (Ziflist::_test) {
     if (info [0]->IsUndefined ())
         return Nan::ThrowTypeError ("method requires a `verbose`");

bindings/nodejs/binding.h

@@ -414,6 +414,7 @@ class Ziflist: public Nan::ObjectWrap {
     static NAN_METHOD (_print);
     static NAN_METHOD (_new_ipv6);
     static NAN_METHOD (_reload_ipv6);
+    static NAN_METHOD (_is_ipv6);
     static NAN_METHOD (_test);
 };
 

bindings/python/czmq/_czmq_ctypes.py

@@ -3120,6 +3120,8 @@ def test(verbose):
 lib.ziflist_new_ipv6.argtypes = []
 lib.ziflist_reload_ipv6.restype = None
 lib.ziflist_reload_ipv6.argtypes = [ziflist_p]
+lib.ziflist_is_ipv6.restype = c_bool
+lib.ziflist_is_ipv6.argtypes = [ziflist_p]
 lib.ziflist_test.restype = None
 lib.ziflist_test.argtypes = [c_bool]
 
@@ -3233,6 +3235,12 @@ def reload_ipv6(self):
         """
         return lib.ziflist_reload_ipv6(self._as_parameter_)
 
+    def is_ipv6(self):
+        """
+        Return true if the current interface uses IPv6
+        """
+        return lib.ziflist_is_ipv6(self._as_parameter_)
+
     @staticmethod
     def test(verbose):
         """

bindings/python_cffi/czmq_cffi.py

@@ -1504,6 +1504,10 @@
 void
     ziflist_reload_ipv6 (ziflist_t *self);
 
+// Return true if the current interface uses IPv6
+bool
+    ziflist_is_ipv6 (ziflist_t *self);
+
 // Self test of this class.
 void
     ziflist_test (bool verbose);

bindings/qml/src/QmlZiflist.cpp

@@ -62,6 +62,12 @@ void QmlZiflist::reloadIpv6 () {
     ziflist_reload_ipv6 (self);
 };
 
+///
+//  Return true if the current interface uses IPv6
+bool QmlZiflist::isIpv6 () {
+    return ziflist_is_ipv6 (self);
+};
+
 
 QObject* QmlZiflist::qmlAttachedProperties(QObject* object) {
     return new QmlZiflistAttached(object);

bindings/qml/src/QmlZiflist.h

@@ -54,6 +54,9 @@ public slots:
 
     //  Reload network interfaces from system, including IPv6
     void reloadIpv6 ();
+
+    //  Return true if the current interface uses IPv6
+    bool isIpv6 ();
 };
 
 class QmlZiflistAttached : public QObject

bindings/qt/src/qziflist.cpp

@@ -110,6 +110,14 @@ void QZiflist::reloadIpv6 ()
 
 }
 
+///
+//  Return true if the current interface uses IPv6
+bool QZiflist::isIpv6 ()
+{
+    bool rv = ziflist_is_ipv6 (self);
+    return rv;
+}
+
 ///
 //  Self test of this class.
 void QZiflist::test (bool verbose)

bindings/qt/src/qziflist.h

@@ -54,6 +54,9 @@ class QT_CZMQ_EXPORT QZiflist : public QObject
     //  Reload network interfaces from system, including IPv6
     void reloadIpv6 ();
 
+    //  Return true if the current interface uses IPv6
+    bool isIpv6 ();
+
     //  Self test of this class.
     static void test (bool verbose);
 

bindings/ruby/lib/czmq/ffi.rb

@@ -453,6 +453,17 @@ def self.ziflist_reload_ipv6(*)
           raise NotImplementedError, "compile CZMQ with --enable-drafts"
         end
       end
+      begin # DRAFT method
+        attach_function :ziflist_is_ipv6, [:pointer], :bool, **opts
+      rescue ::FFI::NotFoundError
+        if $VERBOSE || $DEBUG
+          warn "The DRAFT function ziflist_is_ipv6()" +
+            " is not provided by the installed CZMQ library."
+        end
+        def self.ziflist_is_ipv6(*)
+          raise NotImplementedError, "compile CZMQ with --enable-drafts"
+        end
+      end
       attach_function :ziflist_test, [:bool], :void, **opts
 
       require_relative 'ffi/ziflist'

bindings/ruby/lib/czmq/ffi/ziflist.rb

@@ -190,6 +190,16 @@ def reload_ipv6()
         result
       end
 
+      # Return true if the current interface uses IPv6
+      #
+      # @return [Boolean]
+      def is_ipv6()
+        raise DestroyedError unless @ptr
+        self_p = @ptr
+        result = ::CZMQ::FFI.ziflist_is_ipv6(self_p)
+        result
+      end
+
       # Self test of this class.
       #
       # @param verbose [Boolean]

include/ziflist.h

@@ -82,6 +82,11 @@ CZMQ_EXPORT ziflist_t *
 CZMQ_EXPORT void
     ziflist_reload_ipv6 (ziflist_t *self);
 
+//  *** Draft method, for development use, may change without warning ***
+//  Return true if the current interface uses IPv6
+CZMQ_EXPORT bool
+    ziflist_is_ipv6 (ziflist_t *self);
+
 #endif // CZMQ_BUILD_DRAFT_API
 //  @end
 

src/czmq_classes.h

@@ -112,6 +112,11 @@ CZMQ_PRIVATE ziflist_t *
 CZMQ_PRIVATE void
     ziflist_reload_ipv6 (ziflist_t *self);
 
+//  *** Draft method, defined for internal use only ***
+//  Return true if the current interface uses IPv6
+CZMQ_PRIVATE bool
+    ziflist_is_ipv6 (ziflist_t *self);
+
 //  *** Draft method, defined for internal use only ***
 //  Return message routing ID, if the message came from a ZMQ_SERVER socket.
 //  Else returns zero.                                                      

src/ziflist.c

@@ -30,6 +30,7 @@ typedef struct {
     char *address;
     char *netmask;
     char *broadcast;
+    bool is_ipv6;
 } interface_t;
 
 
@@ -99,6 +100,8 @@ s_interface_new (char *name, struct sockaddr *address, struct sockaddr *netmask,
         assert (self->broadcast);
     }
 
+    self->is_ipv6 = address->sa_family == AF_INET6 ? true : false;
+
     return self;
 }
 
@@ -423,6 +426,18 @@ ziflist_netmask (ziflist_t *self)
 }
 
 
+//  --------------------------------------------------------------------------
+//  Return true if the current interface uses IPv6
+
+bool
+ziflist_is_ipv6 (ziflist_t *self)
+{
+    assert (self);
+    interface_t *iface = (interface_t *) zlistx_item ((zlistx_t *) self);
+    return iface->is_ipv6;
+}
+
+
 //  --------------------------------------------------------------------------
 //  Selftest for this class