how to get frost checkbox state using selenium

I have a frost checkbox defined as :

<div id="protocol_input" class="ember-view frost-checkbox small">
 <input id="protocol_input" class="input ember-view" type="checkbox">
  <label class="label" tabindex="0" for="protocol_input">
   Enable protocol
  <svg xmlns="http://ift.tt/nvqhV5" viewBox="3 2 31 31">
    <rect xmlns="http://ift.tt/nvqhV5" x="10.7" y="15.3" transform="matrix(-0.7071 0.7071 -0.7071 -0.7071 35.6974 26.188)" fill="%23009EEF" width="3.5" height="10.3">
   <polygon xmlns="http://ift.tt/nvqhV5" fill="%23009EEF" points="14.9,25.4 12.4,22.9 26.2,9.4 28.7,12.1">
  </svg>
 </label>
</div>

I can perform click operation on the label/input using selenium, which checks/unchecks the checkbox,

But, I have to get its state that whether checkbox selected or not.

selected property for checkbox is showing false in any of the case.