[Validator] Adds support to check specific DNS record type for URL

Author: Israel J. Carberry

CHANGELOG.md

@@ -6,6 +6,7 @@ CHANGELOG
 
  * not setting the `strict` option of the `Choice` constraint to `true` is
    deprecated and will throw an exception in Symfony 4.0
+ * setting the `checkDNS` option of the `Url` constraint to `true` is deprecated in favor of constant values and will throw an exception in Symfony 4.0
 
 3.3.0
 -----

Constraints/Url.php

@@ -21,6 +21,20 @@
  */
 class Url extends Constraint
 {
+    const CHECK_DNS_TYPE_ANY = 'ANY';
+    const CHECK_DNS_TYPE_NONE = false;
+    const CHECK_DNS_TYPE_A = 'A';
+    const CHECK_DNS_TYPE_A6 = 'A6';
+    const CHECK_DNS_TYPE_AAAA = 'AAAA';
+    const CHECK_DNS_TYPE_CNAME = 'CNAME';
+    const CHECK_DNS_TYPE_MX = 'MX';
+    const CHECK_DNS_TYPE_NAPTR = 'NAPTR';
+    const CHECK_DNS_TYPE_NS = 'NS';
+    const CHECK_DNS_TYPE_PTR = 'PTR';
+    const CHECK_DNS_TYPE_SOA = 'SOA';
+    const CHECK_DNS_TYPE_SRV = 'SRV';
+    const CHECK_DNS_TYPE_TXT = 'TXT';
+
     const INVALID_URL_ERROR = '57c2f299-1154-4870-89bb-ef3b1f5ad229';
 
     protected static $errorNames = array(
@@ -30,5 +44,5 @@ class Url extends Constraint
     public $message = 'This value is not a valid URL.';
     public $dnsMessage = 'The host could not be resolved.';
     public $protocols = array('http', 'https');
-    public $checkDNS = false;
+    public $checkDNS = self::CHECK_DNS_TYPE_NONE;
 }

Constraints/UrlValidator.php

@@ -13,6 +13,7 @@
 
 use Symfony\Component\Validator\Constraint;
 use Symfony\Component\Validator\ConstraintValidator;
+use Symfony\Component\Validator\Exception\InvalidOptionsException;
 use Symfony\Component\Validator\Exception\UnexpectedTypeException;
 
 /**
@@ -72,9 +73,32 @@ public function validate($value, Constraint $constraint)
         }
 
         if ($constraint->checkDNS) {
+            // backwards compatibility
+            if ($constraint->checkDNS === true) {
+                $constraint->checkDNS = Url::CHECK_DNS_TYPE_ANY;
+                @trigger_error(sprintf('Use of the boolean TRUE for the "checkDNS" option in %s is deprecated.  Use Url::CHECK_DNS_TYPE_ANY instead.', Url::class), E_USER_DEPRECATED);
+            }
+
+            if (!in_array($constraint->checkDNS, array(
+                Url::CHECK_DNS_TYPE_ANY,
+                Url::CHECK_DNS_TYPE_A,
+                Url::CHECK_DNS_TYPE_A6,
+                Url::CHECK_DNS_TYPE_AAAA,
+                Url::CHECK_DNS_TYPE_CNAME,
+                Url::CHECK_DNS_TYPE_MX,
+                Url::CHECK_DNS_TYPE_NAPTR,
+                Url::CHECK_DNS_TYPE_NS,
+                Url::CHECK_DNS_TYPE_PTR,
+                Url::CHECK_DNS_TYPE_SOA,
+                Url::CHECK_DNS_TYPE_SRV,
+                Url::CHECK_DNS_TYPE_TXT,
+            ))) {
+                throw new InvalidOptionsException(sprintf('Invalid value for option "checkDNS" in constraint %s', get_class($constraint)), array('checkDNS'));
+            }
+
             $host = parse_url($value, PHP_URL_HOST);
 
-            if (!is_string($host) || !checkdnsrr($host, 'ANY')) {
+            if (!is_string($host) || !checkdnsrr($host, $constraint->checkDNS)) {
                 $this->context->buildViolation($constraint->dnsMessage)
                     ->setParameter('{{ value }}', $this->formatValue($host))
                     ->setCode(Url::INVALID_URL_ERROR)

Tests/Constraints/UrlValidatorTest.php

@@ -203,7 +203,7 @@ public function testCheckDns($violation)
         DnsMock::withMockedHosts(array('example.com' => array(array('type' => $violation ? '' : 'A'))));
 
         $constraint = new Url(array(
-            'checkDNS' => true,
+            'checkDNS' => 'ANY',
             'dnsMessage' => 'myMessage',
         ));
 
@@ -223,6 +223,75 @@ public function getCheckDns()
     {
         return array(array(true), array(false));
     }
+
+    /**
+     * @dataProvider getCheckDnsTypes
+     * @requires function Symfony\Bridge\PhpUnit\DnsMock::withMockedHosts
+     */
+    public function testCheckDnsByType($type)
+    {
+        DnsMock::withMockedHosts(array('example.com' => array(array('type' => $type))));
+
+        $constraint = new Url(array(
+            'checkDNS' => $type,
+            'dnsMessage' => 'myMessage',
+        ));
+
+        $this->validator->validate('http://example.com', $constraint);
+
+        $this->assertNoViolation();
+    }
+
+    public function getCheckDnsTypes()
+    {
+        return array(
+            array('ANY'),
+            array('A'),
+            array('A6'),
+            array('AAAA'),
+            array('CNAME'),
+            array('MX'),
+            array('NAPTR'),
+            array('NS'),
+            array('PTR'),
+            array('SOA'),
+            array('SRV'),
+            array('TXT'),
+        );
+    }
+
+    /**
+     * @group legacy
+     */
+    public function testCheckDnsWithBoolean()
+    {
+        DnsMock::withMockedHosts(array('example.com' => array(array('type' => 'A'))));
+
+        $constraint = new Url(array(
+            'checkDNS' => true,
+            'dnsMessage' => 'myMessage',
+        ));
+
+        $this->validator->validate('http://example.com', $constraint);
+
+        $this->assertNoViolation();
+    }
+
+    /**
+     * @expectedException \Symfony\Component\Validator\Exception\InvalidOptionsException
+     * @requires function Symfony\Bridge\PhpUnit\DnsMock::withMockedHosts
+     */
+    public function testCheckDnsWithInvalidType()
+    {
+        DnsMock::withMockedHosts(array('example.com' => array(array('type' => 'A'))));
+
+        $constraint = new Url(array(
+            'checkDNS' => 'BOGUS',
+            'dnsMessage' => 'myMessage',
+        ));
+
+        $this->validator->validate('http://example.com', $constraint);
+    }
 }
 
 class EmailProvider