Merge pull request #43 from mlocati/ip6-ip4-mapped

Add support for IPv4-Mapped Addresses
mlocati · Jul 16, 2020 · 169aa5b · 169aa5b
2 parents e79c9ac + 0278c8a
commit 169aa5b
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diff --git a/README.md b/README.md
@@ -230,6 +230,30 @@ echo \IPLib\Range\Type::getName($type);
 // 'Unknown type'
 ```
 
+
+### Converting IP addresses
+
+This library supports converting IPv4 to/from IPv6 addresses using the [6to4 notation](https://tools.ietf.org/html/rfc3056) or the [IPv4-mapped notation](https://tools.ietf.org/html/rfc4291#section-2.5.5.2):
+
+```php
+$ipv4 = \IPLib\Factory::addressFromString('1.2.3.4');
+
+// 6to4 notation
+$ipv6 = $ipv4->toIPv6();
+// This will print "2002:102:304::"
+echo (string) $ipv6;
+// This will print "1.2.3.4"
+echo $ipv6->toIPv4();
+
+// IPv4-mapped notation
+$ipv6 = $ipv4->toIPv6IPv4Mapped();
+// This will print "::ffff:1.2.3.4"
+echo (string) $ipv6;
+// This will print "1.2.3.4"
+echo $ipv6_6to4->toIPv4();
+```
+
+
 ### Converting IP ranges
 
 This library supports IPv4/IPv6 ranges in pattern format (eg. `192.168.*.*`) and in CIDR/subnet format (eg. `192.168.0.0/16`), and it offers a way to convert between the two formats:

diff --git a/src/Address/IPv4.php b/src/Address/IPv4.php
@@ -326,7 +326,7 @@ public function getRangeType()
     }
 
     /**
-     * Create an IPv6 representation of this address.
+     * Create an IPv6 representation of this address (in 6to4 notation).
      *
      * @return \IPLib\Address\IPv6
      */
@@ -337,6 +337,16 @@ public function toIPv6()
         return IPv6::fromString('2002:' . sprintf('%02x', $myBytes[0]) . sprintf('%02x', $myBytes[1]) . ':' . sprintf('%02x', $myBytes[2]) . sprintf('%02x', $myBytes[3]) . '::');
     }
 
+    /**
+     * Create an IPv6 representation of this address (in IPv6 IPv4-mapped notation).
+     *
+     * @return \IPLib\Address\IPv6
+     */
+    public function toIPv6IPv4Mapped()
+    {
+        return IPv6::fromBytes(array_merge(array(0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff), $this->getBytes()));
+    }
+
     /**
      * {@inheritdoc}
      *

diff --git a/src/Address/IPv6.php b/src/Address/IPv6.php
@@ -420,12 +420,16 @@ public function getRangeType()
      */
     public function toIPv4()
     {
-        $result = null;
         if (strpos($this->longAddress, '2002:') === 0) {
-            $result = IPv4::fromBytes(array_slice($this->getBytes(), 2, 4));
+            // 6to4
+            return IPv4::fromBytes(array_slice($this->getBytes(), 2, 4));
+        }
+        if (strpos($this->longAddress, '0000:0000:0000:0000:0000:ffff:') === 0) {
+            // IPv4-mapped IPv6 addresses
+            return IPv4::fromBytes(array_slice($this->getBytes(), -4));
         }
 
-        return $result;
+        return null;
     }
 
     /**

diff --git a/test/tests/Addresses/ConversionTest.php b/test/tests/Addresses/ConversionTest.php
@@ -7,7 +7,7 @@
 
 class ConversionTest extends TestCase
 {
-    public function validAddressesProvider()
+    public function get6to4TestCases()
     {
         return array(
             array('0.0.0.0'),
@@ -18,11 +18,11 @@ public function validAddressesProvider()
     }
 
     /**
-     * @dataProvider validAddressesProvider
+     * @dataProvider get6to4TestCases
      *
      * @param string $address
      */
-    public function testV4toV6toV4($address)
+    public function test6to4($address)
     {
         $ipV4 = Factory::addressFromString($address);
         $this->assertNotNull($ipV4, "'{$address}' has been detected as an invalid IP, but it should be valid");
@@ -34,4 +34,32 @@ public function testV4toV6toV4($address)
         $this->assertNotNull($ipV4, "'{$address}' has been converted to '" . $ipV6->toString() . "', but it coulnd't be converted back to IPv4");
         $this->assertSame($address, $ipV4back->toString());
     }
+
+    public function getIPv4MappedAddessTestCases()
+    {
+        return array(
+            array('0.0.0.0'),
+            array('127.0.0.1'),
+            array('10.20.30.40'),
+            array('255.255.255.255'),
+        );
+    }
+
+    /**
+     * @dataProvider getIPv4MappedAddessTestCases
+     *
+     * @param string $address
+     */
+    public function testIPv4MappedAddress($address)
+    {
+        $ipV4 = Factory::addressFromString($address);
+        $this->assertNotNull($ipV4, "'{$address}' has been detected as an invalid IP, but it should be valid");
+        $this->assertInstanceOf('IPLib\Address\IPv4', $ipV4);
+        $ipV6 = $ipV4->toIPv6IPv4Mapped();
+        $this->assertNotNull($ipV6);
+        $this->assertInstanceOf('IPLib\Address\IPv6', $ipV6);
+        $ipV4back = $ipV6->toIPv4();
+        $this->assertNotNull($ipV4, "'{$address}' has been converted to '" . $ipV6->toString() . "', but it coulnd't be converted back to IPv4");
+        $this->assertSame($address, (string) $ipV4back->toString());
+    }
 }