Handle situations where IPv4 multicast is not available

Fixes [Bug #13864]

test/rinda/test_rinda.rb

@@ -583,6 +583,22 @@ def test_take_bug_8215
   end
 end
 
+module RingIPv4
+  def ipv4_mc(rf)
+    begin
+      v4mc = rf.make_socket('239.0.0.1')
+    rescue Errno::ENETUNREACH, Errno::ENOBUFS, Errno::ENODEV
+      omit 'IPv4 multicast not available'
+    end
+
+    begin
+      yield v4mc
+    ensure
+      v4mc.close
+    end
+  end
+end
+
 module RingIPv6
   def prepare_ipv6(r)
     begin
@@ -625,6 +641,7 @@ def ipv6_mc(rf, hops = nil)
 end
 
 class TestRingServer < Test::Unit::TestCase
+  include RingIPv4
 
   def setup
     @port = Rinda::Ring_PORT
@@ -697,27 +714,23 @@ def test_make_socket_unicast
   end
 
   def test_make_socket_ipv4_multicast
-    begin
-      v4mc = @rs.make_socket('239.0.0.1')
-    rescue Errno::ENOBUFS => e
-      omit "Missing multicast support in OS: #{e.message}"
-    end
-
-    begin
-      if Socket.const_defined?(:SO_REUSEPORT) then
-        assert(v4mc.getsockopt(:SOCKET, :SO_REUSEPORT).bool)
-      else
-        assert(v4mc.getsockopt(:SOCKET, :SO_REUSEADDR).bool)
-      end
-    rescue TypeError
-      if /aix/ =~ RUBY_PLATFORM
-        omit "Known bug in getsockopt(2) on AIX"
+    ipv4_mc(@rs) do |v4mc|
+      begin
+        if Socket.const_defined?(:SO_REUSEPORT) then
+          assert(v4mc.getsockopt(:SOCKET, :SO_REUSEPORT).bool)
+        else
+          assert(v4mc.getsockopt(:SOCKET, :SO_REUSEADDR).bool)
+        end
+      rescue TypeError
+        if /aix/ =~ RUBY_PLATFORM
+          omit "Known bug in getsockopt(2) on AIX"
+        end
+        raise $!
       end
-      raise $!
-    end
 
-    assert_equal('0.0.0.0', v4mc.local_address.ip_address)
-    assert_equal(@port,     v4mc.local_address.ip_port)
+      assert_equal('0.0.0.0', v4mc.local_address.ip_address)
+      assert_equal(@port,     v4mc.local_address.ip_port)
+    end
   end
 
   def test_make_socket_ipv6_multicast
@@ -746,7 +759,7 @@ def test_ring_server_ipv4_multicast
     @rs.shutdown
     begin
       @rs = Rinda::RingServer.new(@ts, [['239.0.0.1', '0.0.0.0']], @port)
-    rescue Errno::ENOBUFS => e
+    rescue Errno::ENOBUFS, Errno::ENODEV => e
       omit "Missing multicast support in OS: #{e.message}"
     end
 
@@ -848,6 +861,7 @@ def wait_for(n)
 
 class TestRingFinger < Test::Unit::TestCase
   include RingIPv6
+  include RingIPv4
 
   def setup
     @rf = Rinda::RingFinger.new
@@ -867,12 +881,10 @@ def test_make_socket_unicast
   end
 
   def test_make_socket_ipv4_multicast
-    v4mc = @rf.make_socket('239.0.0.1')
-
-    assert_equal(1, v4mc.getsockopt(:IPPROTO_IP, :IP_MULTICAST_LOOP).ipv4_multicast_loop)
-    assert_equal(1, v4mc.getsockopt(:IPPROTO_IP, :IP_MULTICAST_TTL).ipv4_multicast_ttl)
-  ensure
-    v4mc.close if v4mc
+    ipv4_mc(@rf) do |v4mc|
+      assert_equal(1, v4mc.getsockopt(:IPPROTO_IP, :IP_MULTICAST_LOOP).ipv4_multicast_loop)
+      assert_equal(1, v4mc.getsockopt(:IPPROTO_IP, :IP_MULTICAST_TTL).ipv4_multicast_ttl)
+    end
   end
 
   def test_make_socket_ipv6_multicast
@@ -884,10 +896,9 @@ def test_make_socket_ipv6_multicast
 
   def test_make_socket_ipv4_multicast_hops
     @rf.multicast_hops = 2
-    v4mc = @rf.make_socket('239.0.0.1')
-    assert_equal(2, v4mc.getsockopt(:IPPROTO_IP, :IP_MULTICAST_TTL).ipv4_multicast_ttl)
-  ensure
-    v4mc.close if v4mc
+    ipv4_mc(@rf) do |v4mc|
+      assert_equal(2, v4mc.getsockopt(:IPPROTO_IP, :IP_MULTICAST_TTL).ipv4_multicast_ttl)
+    end
   end
 
   def test_make_socket_ipv6_multicast_hops