php通过判断来源主机头进行防盗链
check.php
<span style="color: #0000ff;"><span style="color: #800000;">html</span><span style="color: #0000ff;">></span><span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span><span style="color: #0000ff;"><span style="color: #800000;">form </span><span style="color: #ff0000;">action</span><span style="color: #0000ff;">="test.php"</span><span style="color: #ff0000;"> method</span><span style="color: #0000ff;">="post"</span><span style="color: #0000ff;">></span><span style="color: #000000;"> message</span><span style="color: #0000ff;"><span style="color: #800000;">input </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="text"</span><span style="color: #ff0000;"> name</span><span style="color: #0000ff;">="name"</span><span style="color: #ff0000;"> value</span><span style="color: #0000ff;">="123456"</span> <span style="color: #0000ff;">/></span> <span style="color: #0000ff;"><span style="color: #800000;">input </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="submit"</span><span style="color: #ff0000;"> value</span><span style="color: #0000ff;">="submit"</span> <span style="color: #0000ff;">/></span><span style="color: #0000ff;"></span><span style="color: #800000;">form</span><span style="color: #0000ff;">></span><span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span><span style="color: #0000ff;"></span><span style="color: #800000;">html</span><span style="color: #0000ff;">></span></span></span></span></span></span>
test.php
<span style="color: #000000;">php</span><span style="color: #008080;">header</span>("Content-type:text/html;charset='utf8'"<span style="color: #000000;">);</span><span style="color: #008080;">error_reporting</span>(<span style="color: #ff00ff;">E_ALL</span><span style="color: #000000;">);</span><span style="color: #800080;">$url</span> = <span style="color: #008080;">parse_url</span>(<span style="color: #800080;">$_SERVER</span>['HTTP_REFERER'<span style="color: #000000;">]);</span><span style="color: #008000;">//</span><span style="color: #008000;">print_r($url);</span><span style="color: #0000ff;">if</span>(<span style="color: #800080;">$url</span>['host'] != "localhost"<span style="color: #000000;">){ </span><span style="color: #0000ff;">echo</span> "<script>alert('host error.');history.go(-1);</script>"<span style="color: #000000;">; </span><span style="color: #0000ff;">exit</span>(0<span style="color: #000000;">);}</span><span style="color: #0000ff;">else</span><span style="color: #000000;">{ </span><span style="color: #0000ff;">echo</span> "<script>alert('host right.');</script>"<span style="color: #000000;">; </span><span style="color: #0000ff;">echo</span> "<h1>Hello World!</h1>"<span style="color: #000000;">;}</span>