用php实现vpn用户随机生成

<?php

session_start();


@$ComeUrl = $_SERVER['HTTP_REFERER'];
$MyHost = "www.e1231.com";
$file = '/etc/ppp/chap-secrets';
$getime = 2;

//随机生成字符.我这里用户是5位数,密码是8位数
function get_randstr( $length = 8 ) {
	// 密码字符集，可任意添加你需要的字符
	$chars = 'abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789';

	$str = '';
	for ( $i = 0; $i < $length; $i++ )
	{
		// 这里提供两种字符获取方式
		// 第一种是使用 substr 截取$chars中的任意一位字符；
		// 第二种是取字符数组 $chars 的任意元素
		// $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
		$str .= $chars[ mt_rand(0, strlen($chars) - 1) ];
	}

	return $str;
}

//写入vpn账号密码到ppp的密码文件
function write_user( $user,$password ) {
	global $file;
	$fd = fopen($file,'a+');
	if(!$fd)
		exit(1);
	$str = "$user pptpd $password *\n";
	
	$re = fwrite($fd,$str);
	if(!$re)
		exit(2);
	echo "your user : $user";
	echo "<br />";
	echo "your password : $password ";
	fclose($fd);
	@$_SESSION['time']++;
	return 0;
}

function get_host( $url ) {
	$arr = explode('/',$url,4);
	if(@$arr[2])
		return $arr[2];
}		

//如果不是从我网站过来.就告诉他要去我网站逛逛.
$host = get_host($ComeUrl);
//print "$host = $MyHost <br />";

if(@$_SESSION['time'] > $getime){
	echo "你已经获取过 ".($getime+1)." 次,请休息一下吧!";
	echo "<br />";
	echo "随便看看? -> <a href=http://$MyHost>$MyHost</a>";
	exit(4);
}

if($host != $MyHost) {
	echo "you come from $ComeUrl";
	echo "<br />";
	echo "but you must go My site";
	echo " <a href=http://$MyHost>$MyHost</a>";
} else {
	$user = get_randstr(5);
	$password = get_randstr(11);
	$re = write_user($user,$password);
}

?>