在php中获取IP地址不准确

Question

我有一个应用程序可以在 php 中获取用户 ip 地址所在位置的纬度和经度，但结果并不准确，这是我的代码

<form action="" method="POST">
<input type="submit" name="ipBtn" value="Get ip address">
    <?php 
     if(isset($_POST['ipBtn'])) {
        $user_ip = getenv('REMOTE_ADDR');
        $geo = unserialize(file_get_contents("http://www.geoplugin.net/php.gp?ip=$user_ip"));
        $country = $geo["geoplugin_countryName"];
        $region = $geo["geoplugin_region"];
        $longitude = $geo["geoplugin_longitude"];
        $latitude = $geo["geoplugin_latitude"];
        $first_name = $_GET[userName];
        $password = $_GET['last_name'];
    ?>

</form>

Answer 1

获取访问者/客户的IP address 的最简单方法是使用$_SERVER['REMOTE_ADDR'] 或$_SERVER['REMOTE_HOST'] 变量。

但是，有时这不会返回访问者的正确 IP 地址，因此我们可以使用其他一些服务器变量来获取 IP 地址。

以下两个函数是等价的，不同之处仅在于检索值的方式和来源。

getenv() 用于在 PHP 中获取环境变量的值。

// Function to get the client IP address
function get_client_ip() {
    $ipaddress = '';
    if (getenv('HTTP_CLIENT_IP'))
        $ipaddress = getenv('HTTP_CLIENT_IP');
    else if(getenv('HTTP_X_FORWARDED_FOR'))
        $ipaddress = getenv('HTTP_X_FORWARDED_FOR');
    else if(getenv('HTTP_X_FORWARDED'))
        $ipaddress = getenv('HTTP_X_FORWARDED');
    else if(getenv('HTTP_FORWARDED_FOR'))
        $ipaddress = getenv('HTTP_FORWARDED_FOR');
    else if(getenv('HTTP_FORWARDED'))
       $ipaddress = getenv('HTTP_FORWARDED');
    else if(getenv('REMOTE_ADDR'))
        $ipaddress = getenv('REMOTE_ADDR');
    else
        $ipaddress = 'UNKNOWN';
    return $ipaddress;
}

$_SERVER 是一个数组，其中包含由 Web 服务器创建的服务器变量。

// Function to get the client IP address
function get_client_ip() {
    $ipaddress = '';
    if (isset($_SERVER['HTTP_CLIENT_IP']))
        $ipaddress = $_SERVER['HTTP_CLIENT_IP'];
    else if(isset($_SERVER['HTTP_X_FORWARDED_FOR']))
        $ipaddress = $_SERVER['HTTP_X_FORWARDED_FOR'];
    else if(isset($_SERVER['HTTP_X_FORWARDED']))
        $ipaddress = $_SERVER['HTTP_X_FORWARDED'];
    else if(isset($_SERVER['HTTP_FORWARDED_FOR']))
        $ipaddress = $_SERVER['HTTP_FORWARDED_FOR'];
    else if(isset($_SERVER['HTTP_FORWARDED']))
        $ipaddress = $_SERVER['HTTP_FORWARDED'];
    else if(isset($_SERVER['REMOTE_ADDR']))
        $ipaddress = $_SERVER['REMOTE_ADDR'];
    else
        $ipaddress = 'UNKNOWN';
    return $ipaddress;
}