1 files changed, 147 insertions, 0 deletions
diff --git a/vendor/react/dns/src/Resolver/Resolver.php b/vendor/react/dns/src/Resolver/Resolver.php
new file mode 100644
index 0000000..92926f3
--- /dev/null
+++ b/vendor/react/dns/src/Resolver/Resolver.php
@@ -0,0 +1,147 @@
+<?php
+
+namespace React\Dns\Resolver;
+
+use React\Dns\Model\Message;
+use React\Dns\Query\ExecutorInterface;
+use React\Dns\Query\Query;
+use React\Dns\RecordNotFoundException;
+
+/**
+ * @see ResolverInterface for the base interface
+ */
+final class Resolver implements ResolverInterface
+{
+    private $executor;
+
+    public function __construct(ExecutorInterface $executor)
+    {
+        $this->executor = $executor;
+    }
+
+    public function resolve($domain)
+    {
+        return $this->resolveAll($domain, Message::TYPE_A)->then(function (array $ips) {
+            return $ips[array_rand($ips)];
+        });
+    }
+
+    public function resolveAll($domain, $type)
+    {
+        $query = new Query($domain, $type, Message::CLASS_IN);
+        $that = $this;
+
+        return $this->executor->query(
+            $query
+        )->then(function (Message $response) use ($query, $that) {
+            return $that->extractValues($query, $response);
+        });
+    }
+
+    /**
+     * [Internal] extract all resource record values from response for this query
+     *
+     * @param Query   $query
+     * @param Message $response
+     * @return array
+     * @throws RecordNotFoundException when response indicates an error or contains no data
+     * @internal
+     */
+    public function extractValues(Query $query, Message $response)
+    {
+        // reject if response code indicates this is an error response message
+        $code = $response->rcode;
+        if ($code !== Message::RCODE_OK) {
+            switch ($code) {
+                case Message::RCODE_FORMAT_ERROR:
+                    $message = 'Format Error';
+                    break;
+                case Message::RCODE_SERVER_FAILURE:
+                    $message = 'Server Failure';
+                    break;
+                case Message::RCODE_NAME_ERROR:
+                    $message = 'Non-Existent Domain / NXDOMAIN';
+                    break;
+                case Message::RCODE_NOT_IMPLEMENTED:
+                    $message = 'Not Implemented';
+                    break;
+                case Message::RCODE_REFUSED:
+                    $message = 'Refused';
+                    break;
+                default:
+                    $message = 'Unknown error response code ' . $code;
+            }
+            throw new RecordNotFoundException(
+                'DNS query for ' . $query->describe() . ' returned an error response (' . $message . ')',
+                $code
+            );
+        }
+
+        $answers = $response->answers;
+        $addresses = $this->valuesByNameAndType($answers, $query->name, $query->type);
+
+        // reject if we did not receive a valid answer (domain is valid, but no record for this type could be found)
+        if (0 === count($addresses)) {
+            throw new RecordNotFoundException(
+                'DNS query for ' . $query->describe() . ' did not return a valid answer (NOERROR / NODATA)'
+            );
+        }
+
+        return array_values($addresses);
+    }
+
+    /**
+     * @param \React\Dns\Model\Record[] $answers
+     * @param string                    $name
+     * @param int                       $type
+     * @return array
+     */
+    private function valuesByNameAndType(array $answers, $name, $type)
+    {
+        // return all record values for this name and type (if any)
+        $named = $this->filterByName($answers, $name);
+        $records = $this->filterByType($named, $type);
+        if ($records) {
+            return $this->mapRecordData($records);
+        }
+
+        // no matching records found? check if there are any matching CNAMEs instead
+        $cnameRecords = $this->filterByType($named, Message::TYPE_CNAME);
+        if ($cnameRecords) {
+            $cnames = $this->mapRecordData($cnameRecords);
+            foreach ($cnames as $cname) {
+                $records = array_merge(
+                    $records,
+                    $this->valuesByNameAndType($answers, $cname, $type)
+                );
+            }
+        }
+
+        return $records;
+    }
+
+    private function filterByName(array $answers, $name)
+    {
+        return $this->filterByField($answers, 'name', $name);
+    }
+
+    private function filterByType(array $answers, $type)
+    {
+        return $this->filterByField($answers, 'type', $type);
+    }
+
+    private function filterByField(array $answers, $field, $value)
+    {
+        $value = strtolower($value);
+        return array_filter($answers, function ($answer) use ($field, $value) {
+            return $value === strtolower($answer->$field);
+        });
+    }
+
+    private function mapRecordData(array $records)
+    {
+        return array_map(function ($record) {
+            return $record->data;
+        }, $records);
+    }
+}