Add port validation rule for #68

app/Rules/Port.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace App\Rules;
+
+use Closure;
+use Illuminate\Contracts\Validation\ValidationRule;
+
+class Port implements ValidationRule
+{
+    /**
+     * Run the validation rule.
+     *
+     * @param  \Closure(string): \Illuminate\Translation\PotentiallyTranslatedString  $fail
+     */
+    public function validate(string $attribute, mixed $value, Closure $fail): void
+    {
+        if (!is_numeric($value)) {
+            $fail('The :attribute must be numeric.');
+        }
+
+        $value = intval($value);
+        if (floatval($value) !== (float) $value) {
+            $fail('The :attribute must be an integer.');
+        }
+
+        if ($value < 0) {
+            $fail('The :attribute must be greater or equal to 0.');
+        }
+
+        if ($value > 65535) {
+            $fail('The :attribute must be less or equal to 65535.');
+        }
+    }
+}