Why WordPress attachments LINK TO settings are not working?

Using this code below, I added some on-hover share icons for all images of the content. But, now these images are not getting any "Link To" setting from authors. I don't know what is the problem. Can anyone please look at this code below and guide me?

public function 
    Add_Pin_Button($content){
            global $post;

        // Get the post urls
        $posturl = urlencode(get_permalink());

        // Define a pattern to find all images inside the content
        $pattern = '/<img(.*?)src="(.*?).(bmp|gif|jpeg|jpg|png)" (.*?) width="(.*?)" height="(.*?)" \/>/i';

        // Replace the images with the following div and pin button
        $button_div = '<div class="democlass">
        <div class="secondclass">
            <div class="thirdclass">
                <a href="http://ift.tt/OxyLGR' . get_permalink().'&title='.get_the_title().'">
                    <img src="http://ift.tt/1DkDhoJ" width="45px" />
                </a>
            </div>

        </div>

            <div class="disdemo"><img$1src="$2.$3" $4 width="$5" height="$6" /></div> </div>
            ';

        // Replace the images with a containing div with a pin button on the image
        $content = preg_replace( $pattern, $button_div, $content );

        return $content;
    }

And how to add attachment link to all images of the content?