1<?php
2
3/*
4 * This file is part of the Symfony package.
5 *
6 * (c) Fabien Potencier <fabien@symfony.com>
7 *
8 * For the full copyright and license information, please view the LICENSE
9 * file that was distributed with this source code.
10 */
11
12namespace Symfony\Component\HttpFoundation;
13
14/**
15 * Http utility functions.
16 *
17 * @author Fabien Potencier <fabien@symfony.com>
18 */
19class IpUtils
20{
21    private static $checkedIps = [];
22
23    /**
24     * This class should not be instantiated.
25     */
26    private function __construct()
27    {
28    }
29
30    /**
31     * Checks if an IPv4 or IPv6 address is contained in the list of given IPs or subnets.
32     *
33     * @param string       $requestIp IP to check
34     * @param string|array $ips       List of IPs or subnets (can be a string if only a single one)
35     *
36     * @return bool Whether the IP is valid
37     */
38    public static function checkIp($requestIp, $ips)
39    {
40        if (!\is_array($ips)) {
41            $ips = [$ips];
42        }
43
44        $method = substr_count($requestIp, ':') > 1 ? 'checkIp6' : 'checkIp4';
45
46        foreach ($ips as $ip) {
47            if (self::$method($requestIp, $ip)) {
48                return true;
49            }
50        }
51
52        return false;
53    }
54
55    /**
56     * Compares two IPv4 addresses.
57     * In case a subnet is given, it checks if it contains the request IP.
58     *
59     * @param string $requestIp IPv4 address to check
60     * @param string $ip        IPv4 address or subnet in CIDR notation
61     *
62     * @return bool Whether the request IP matches the IP, or whether the request IP is within the CIDR subnet
63     */
64    public static function checkIp4($requestIp, $ip)
65    {
66        $cacheKey = $requestIp.'-'.$ip;
67        if (isset(self::$checkedIps[$cacheKey])) {
68            return self::$checkedIps[$cacheKey];
69        }
70
71        if (!filter_var($requestIp, \FILTER_VALIDATE_IP, \FILTER_FLAG_IPV4)) {
72            return self::$checkedIps[$cacheKey] = false;
73        }
74
75        if (false !== strpos($ip, '/')) {
76            [$address, $netmask] = explode('/', $ip, 2);
77
78            if ('0' === $netmask) {
79                return self::$checkedIps[$cacheKey] = filter_var($address, \FILTER_VALIDATE_IP, \FILTER_FLAG_IPV4);
80            }
81
82            if ($netmask < 0 || $netmask > 32) {
83                return self::$checkedIps[$cacheKey] = false;
84            }
85        } else {
86            $address = $ip;
87            $netmask = 32;
88        }
89
90        if (false === ip2long($address)) {
91            return self::$checkedIps[$cacheKey] = false;
92        }
93
94        return self::$checkedIps[$cacheKey] = 0 === substr_compare(sprintf('%032b', ip2long($requestIp)), sprintf('%032b', ip2long($address)), 0, $netmask);
95    }
96
97    /**
98     * Compares two IPv6 addresses.
99     * In case a subnet is given, it checks if it contains the request IP.
100     *
101     * @author David Soria Parra <dsp at php dot net>
102     *
103     * @see https://github.com/dsp/v6tools
104     *
105     * @param string $requestIp IPv6 address to check
106     * @param string $ip        IPv6 address or subnet in CIDR notation
107     *
108     * @return bool Whether the IP is valid
109     *
110     * @throws \RuntimeException When IPV6 support is not enabled
111     */
112    public static function checkIp6($requestIp, $ip)
113    {
114        $cacheKey = $requestIp.'-'.$ip;
115        if (isset(self::$checkedIps[$cacheKey])) {
116            return self::$checkedIps[$cacheKey];
117        }
118
119        if (!((\extension_loaded('sockets') && \defined('AF_INET6')) || @inet_pton('::1'))) {
120            throw new \RuntimeException('Unable to check Ipv6. Check that PHP was not compiled with option "disable-ipv6".');
121        }
122
123        if (false !== strpos($ip, '/')) {
124            [$address, $netmask] = explode('/', $ip, 2);
125
126            if ('0' === $netmask) {
127                return (bool) unpack('n*', @inet_pton($address));
128            }
129
130            if ($netmask < 1 || $netmask > 128) {
131                return self::$checkedIps[$cacheKey] = false;
132            }
133        } else {
134            $address = $ip;
135            $netmask = 128;
136        }
137
138        $bytesAddr = unpack('n*', @inet_pton($address));
139        $bytesTest = unpack('n*', @inet_pton($requestIp));
140
141        if (!$bytesAddr || !$bytesTest) {
142            return self::$checkedIps[$cacheKey] = false;
143        }
144
145        for ($i = 1, $ceil = ceil($netmask / 16); $i <= $ceil; ++$i) {
146            $left = $netmask - 16 * ($i - 1);
147            $left = ($left <= 16) ? $left : 16;
148            $mask = ~(0xffff >> $left) & 0xffff;
149            if (($bytesAddr[$i] & $mask) != ($bytesTest[$i] & $mask)) {
150                return self::$checkedIps[$cacheKey] = false;
151            }
152        }
153
154        return self::$checkedIps[$cacheKey] = true;
155    }
156
157    /**
158     * Anonymizes an IP/IPv6.
159     *
160     * Removes the last byte for v4 and the last 8 bytes for v6 IPs
161     */
162    public static function anonymize(string $ip): string
163    {
164        $wrappedIPv6 = false;
165        if ('[' === substr($ip, 0, 1) && ']' === substr($ip, -1, 1)) {
166            $wrappedIPv6 = true;
167            $ip = substr($ip, 1, -1);
168        }
169
170        $packedAddress = inet_pton($ip);
171        if (4 === \strlen($packedAddress)) {
172            $mask = '255.255.255.0';
173        } elseif ($ip === inet_ntop($packedAddress & inet_pton('::ffff:ffff:ffff'))) {
174            $mask = '::ffff:ffff:ff00';
175        } elseif ($ip === inet_ntop($packedAddress & inet_pton('::ffff:ffff'))) {
176            $mask = '::ffff:ff00';
177        } else {
178            $mask = 'ffff:ffff:ffff:ffff:0000:0000:0000:0000';
179        }
180        $ip = inet_ntop($packedAddress & inet_pton($mask));
181
182        if ($wrappedIPv6) {
183            $ip = '['.$ip.']';
184        }
185
186        return $ip;
187    }
188}
189