Don't resolve database hosts; closes #2237

app/Http/Middleware/Api/Client/Server/SubuserBelongsToServer.php

@@ -3,7 +3,6 @@
 namespace Pterodactyl\Http\Middleware\Api\Client\Server;
 
 use Closure;
-use Exception;
 use Illuminate\Http\Request;
 
 class SubuserBelongsToServer

app/Http/Requests/Admin/DatabaseHostFormRequest.php

@@ -29,10 +29,6 @@ class DatabaseHostFormRequest extends AdminFormRequest
             $this->merge(['node_id' => null]);
         }
 
-        $this->merge([
-            'host' => gethostbyname($this->input('host')),
-        ]);
-
         return parent::getValidatorInstance();
     }
 }

app/Models/DatabaseHost.php

@@ -2,6 +2,8 @@
 
 namespace Pterodactyl\Models;
 
+use Pterodactyl\Rules\ResolvesToIPAddress;
+
 class DatabaseHost extends Model
 {
     /**
@@ -51,13 +53,25 @@ class DatabaseHost extends Model
      */
     public static $validationRules = [
         'name' => 'required|string|max:255',
-        'host' => 'required|unique:database_hosts,host',
+        'host' => 'required|string',
         'port' => 'required|numeric|between:1,65535',
         'username' => 'required|string|max:32',
         'password' => 'nullable|string',
         'node_id' => 'sometimes|nullable|integer|exists:nodes,id',
     ];
 
+    /**
+     * @return array
+     */
+    public static function getRules()
+    {
+        $rules = parent::getRules();
+
+        $rules['host'] = array_merge($rules['host'], [ new ResolvesToIPAddress() ]);
+
+        return $rules;
+    }
+
     /**
      * Gets the node associated with a database host.
      *

app/Rules/ResolvesToIPAddress.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace Pterodactyl\Rules;
+
+use Illuminate\Contracts\Validation\Rule;
+
+class ResolvesToIPAddress implements Rule
+{
+    /**
+     * Validate that a given string can correctly resolve to a valid IPv4 address.
+     *
+     * @param string $attribute
+     * @param mixed $value
+     * @return bool
+     */
+    public function passes($attribute, $value): bool
+    {
+        // inet_pton returns false if the value passed through is not a valid IP address, so we'll just
+        // use that a nice ugly PHP hack to determine if we should pass this off to the gethostbyname
+        // call below.
+        $isIP = inet_pton($attribute) !== false;
+
+        // If the value received is not an IP address try to look it up using the gethostbyname() call.
+        // If that returns the same value that we passed in then it means it did not resolve to anything
+        // and we should fail this validation call.
+        return $isIP || gethostbyname($value) !== $value;
+    }
+
+    /**
+     * Return a validation message for use when this rule fails.
+     *
+     * @return string
+     */
+    public function message(): string
+    {
+        return 'The :attribute must be a valid IPv4 address or hostname that resolves to a valid IPv4 address.';
+    }
+
+    /**
+     * Convert the rule to a validation string. This is necessary to avoid
+     * issues with Eloquence which tries to use this rule as a string.
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return 'p_resolves_to_ip_address';
+    }
+}