概要

googlebotなどのクローラーがアクセスしてきた時に、特定の処理を除外するために書いた。例えば広告を表示しないなど。

参考:IPアドレスが指定した範囲内にあるかどうか判別する

範囲の形式

完全一致 192.168.0.1
マスク 192.168.0.0/24
マスク 192.168.0.100/24
from/to 192.168.0.100/192.168.0.200

PHPUnitテスト

public function test_accept_ip() {

    // 完全一致
    $this->assertTrue(accept_ip('192.168.0.1', '192.168.0.1'));
    $this->assertFalse(accept_ip('192.168.0.1', '192.168.0.22'));

    // マスク
    $this->assertTrue(accept_ip('192.168.0.1', '192.168.0.0/24'));
    $this->assertFalse(accept_ip('192.168.0.1', '192.168.0.22/24'));
    $this->assertTrue(accept_ip('192.168.0.23', '192.168.0.22/24'));
    $this->assertTrue(accept_ip('66.249.71.129', '66.249.71.128/27'));
    $this->assertFalse(accept_ip('66.249.71.127', '66.249.71.128/27'));
    $this->assertFalse(accept_ip('66.249.64.191', '66.249.64.192/27'));
    $this->assertTrue(accept_ip('66.249.64.192', '66.249.64.192/27'));
    $this->assertTrue(accept_ip('66.249.64.223', '66.249.64.192/27'));
    $this->assertFalse(accept_ip('66.249.64.224', '66.249.64.192/27'));

    // from/to
    $this->assertTrue(accept_ip('148.64.56.64', '148.64.56.64/148.64.56.80'));
    $this->assertFalse(accept_ip('148.64.56.63', '148.64.56.64/148.64.56.80'));
    $this->assertTrue(accept_ip('148.64.56.80', '148.64.56.64/148.64.56.80'));
    $this->assertFalse(accept_ip('148.64.56.81', '148.64.56.64/148.64.56.80'));

    // 引数が不正
    set_error_handler(function(){});
    $this->assertFalse(accept_ip('', null));
    $this->assertFalse(accept_ip(null, null));
    $this->assertFalse(accept_ip('ABCDEFG', null));
    $this->assertFalse(accept_ip('148.64.56.81', ''));
    $this->assertFalse(accept_ip('148.64.56.81', null));
    $this->assertFalse(accept_ip('148.64.56.81', 'ABCDEFG'));
    $this->assertFalse(accept_ip('148.64.56.81', 'ABCDEFG/24'));
    $this->assertFalse(accept_ip('148.64.56.81', '148.64.56.64/ABCDEFG'));
    $this->assertFalse(accept_ip('148.64.56.81', 'ABCDEFG/148.64.56.64'));
}

PHP

/**
 * $remote_ipが$accept_ipの定義に当てはまるか
 * @see 参考 https://qiita.com/ran/items/039706c93a8ff85a011a
 *
 * @param string $remote_ip
 * @param string $accept_ip
 * @return bool
 *
 */
function accept_ip($remote_ip, $accept_ip) {

    if (! valid_ip($remote_ip, 'ipv4')) {
        trigger_error(__FUNCTION__.'(): Argument #1 ($remote_ip) must be in the form of an IP address.', E_USER_WARNING);
        return false;
    }

    if (strpos($accept_ip, '/')) {
        $tmp = explode('/', $accept_ip);
        $accept_ip = $tmp[0];
        $remote_long = ip2long($remote_ip);

        // サブネットマスク のパターン
        if (ctype_digit($tmp[1])) {
            if (! valid_ip($accept_ip, 'ipv4')) {
                trigger_error(__FUNCTION__.'(): Argument #2 ($accept_ip) must be in the form of an IP address.', E_USER_WARNING);
                return false;
            }
            $mask = $tmp[1];
            $accept_long = ip2long($accept_ip);
            $remote_long_prefix = $remote_long >> (32 - $mask);
            $accept_long_prefix = $accept_long >> (32 - $mask);
            return ($remote_long_prefix === $accept_long_prefix && $remote_long >= $accept_long);
        }

        // 範囲下/範囲上 のパターン
        else if (valid_ip($tmp[1], 'ipv4')) {
            $accept_long_gte = ip2long($accept_ip);
            $accept_long_lte = ip2long($tmp[1]);
            return ($accept_long_gte <= $remote_long && $remote_long <= $accept_long_lte);
        }

        trigger_error(__FUNCTION__.'(): Argument #2 ($accept_ip) must be in the form of an IP address.', E_USER_WARNING);
        return false;
    }

    if (! valid_ip($accept_ip, 'ipv4')) {
        trigger_error(__FUNCTION__.'(): Argument #2 ($accept_ip) must be in the form of an IP address.', E_USER_WARNING);
        return false;
    }

    if ($accept_ip === $remote_ip) {
        return true;
    }
    return false;
}

/**
 * Validate IP Address
 *
 * @param string $ip
 * @param string $options 'ipv4' or 'ipv6' to validate a specific IP format
 * @return bool
 */
function valid_ip($ip, $options = null) {
    if (! is_null($options)) {
        $which = strtolower($options);
        if ('ipv4' === $which) {
            $options = 1048576;
        }
        else if ('ipv6' === $which) {
            $options = 2097152;
        }
    }
    return (bool)filter_var($ip, 275, $options);
}