Add IPv4 subnet validation

lib/ipaddress.rb

@@ -102,21 +102,63 @@ module IPAddress
     self.kind_of? IPAddress::IPv6
   end
 
+
+  #
+  # Checks if the given string is either a valid IP, either a valid IPv4 subnet
+  #
+  # Example:
+  #
+  #   IPAddress::valid? "10.0.0.0/24"
+  #     #=> true
+  #
+  #   IPAddress::valid? "2002::1"
+  #     #=> true
+  #
+  #   IPAddress::valid? "10.0.0.256"
+  #     #=> false
+  #
+  #   IPAddress::valid? "10.0.0.0/999"
+  #     #=> false
+  #
+  def self.valid?(addr)
+    valid_ip?(addr) || valid_ipv4_subnet?(addr)
+  end
+
   # 
   # Checks if the given string is a valid IP address,
   # either IPv4 or IPv6
   #
   # Example:
   #
-  #   IPAddress::valid? "2002::1"
+  #   IPAddress::valid_ip? "2002::1"
   #     #=> true
   #
-  #   IPAddress::valid? "10.0.0.256"   
+  #   IPAddress::valid_ip? "10.0.0.256"
   #     #=> false
   #
-  def self.valid?(addr)
+  def self.valid_ip?(addr)
     valid_ipv4?(addr) || valid_ipv6?(addr)
   end
+
+  #
+  # Checks if the given string is a valid IPv4 subnet
+  #
+  # Example:
+  #
+  #   IPAdress::valid_ipv4_subnet? "10.0.0.0/24"
+  #     #=> true
+  #
+  #   IPAdress::valid_ipv4_subnet? "10.0.0.0/255.255.255.0"
+  #     #=> true
+  #
+  #   IPAdress::valid_ipv4_subnet? "10.0.0.0/64"
+  #     #=> false
+  #
+  def self.valid_ipv4_subnet?(addr)
+    ip, netmask = addr.split("/")
+
+    valid_ipv4?(ip) && (!(netmask =~ /\A([12]?\d|3[0-2])\z/).nil? || valid_ipv4_netmask?(netmask))
+  end
   
   #
   # Checks if the given string is a valid IPv4 address

test/ipaddress_test.rb

@@ -59,6 +59,13 @@ class IPAddressTest < Minitest::Test
   end
 
   def test_module_method_valid?
+    assert_equal true, IPAddress::valid?("10.0.0.0/24")
+    assert_equal true, IPAddress::valid?("10.0.0.0/255.255.255.0")
+    assert_equal false, IPAddress::valid?("10.0.0.0/64")
+    assert_equal false, IPAddress::valid?("10.0.0.0/255.255.255.256")
+  end
+
+  def test_module_method_valid_ip?
     assert_equal true, IPAddress::valid?("10.0.0.1")
     assert_equal true, IPAddress::valid?("10.0.0.0")
     assert_equal true, IPAddress::valid?("2002::1")
@@ -69,14 +76,24 @@ class IPAddressTest < Minitest::Test
     assert_equal false, IPAddress::valid?("10.0")
     assert_equal false, IPAddress::valid?("2002:::1")
     assert_equal false, IPAddress::valid?("2002:516:2:200")
-
   end
 
-  def test_module_method_valid_ipv4_netmark?
+  def test_module_method_valid_ipv4_netmask?
     assert_equal true, IPAddress::valid_ipv4_netmask?("255.255.255.0")
     assert_equal false, IPAddress::valid_ipv4_netmask?("10.0.0.1")
   end
 
+  def test_module_method_valid_ipv4_subnet?
+    assert_equal true, IPAddress::valid_ipv4_subnet?("10.0.0.0/255.255.255.0")
+    assert_equal true, IPAddress::valid_ipv4_subnet?("10.0.0.0/0")
+    assert_equal true, IPAddress::valid_ipv4_subnet?("10.0.0.0/32")
+    assert_equal false, IPAddress::valid_ipv4_subnet?("10.0.0.0/ABC")
+    assert_equal false, IPAddress::valid_ipv4_subnet?("10.0.0.1")
+    assert_equal false, IPAddress::valid_ipv4_subnet?("10.0.0.0/33")
+    assert_equal false, IPAddress::valid_ipv4_subnet?("10.0.0.256/24")
+    assert_equal false, IPAddress::valid_ipv4_subnet?("10.0.0.0/255.255.255.256")
+  end
+
 end