Subversion Repositories php-qbpwcf

<?php

namespace React\Dns\Config;

use RuntimeException;

/**

 * Represents a static hosts file which maps hostnames to IPs

 *

 * Hosts files are used on most systems to avoid actually hitting the DNS for

 * certain common hostnames.

 *

 * Most notably, this file usually contains an entry to map "localhost" to the

 * local IP. Windows is a notable exception here, as Windows does not actually

 * include "localhost" in this file by default. To compensate for this, this

 * class may explicitly be wrapped in another HostsFile instance which

 * hard-codes these entries for Windows (see also Factory).

 *

 * This class mostly exists to abstract the parsing/extraction process so this

 * can be replaced with a faster alternative in the future.

 */

class HostsFile

{

    /**

     * Returns the default path for the hosts file on this system

     *

     * @return string

     * @codeCoverageIgnore

     */

    public static function getDefaultPath()

    {

        // use static path for all Unix-based systems

        if (DIRECTORY_SEPARATOR !== '\\') {

            return '/etc/hosts';

        }

        // Windows actually stores the path in the registry under

        // \HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\DataBasePath

        $path = '%SystemRoot%\\system32\drivers\etc\hosts';

        $base = getenv('SystemRoot');

        if ($base === false) {

            $base = 'C:\\Windows';

        }

        return str_replace('%SystemRoot%', $base, $path);

    }

    /**

     * Loads a hosts file (from the given path or default location)

     *

     * Note that this method blocks while loading the given path and should

     * thus be used with care! While this should be relatively fast for normal

     * hosts file, this may be an issue if this file is located on a slow device

     * or contains an excessive number of entries. In particular, this method

     * should only be executed before the loop starts, not while it is running.

     *

     * @param ?string $path (optional) path to hosts file or null=load default location

     * @return self

     * @throws RuntimeException if the path can not be loaded (does not exist)

     */

    public static function loadFromPathBlocking($path = null)

    {

        if ($path === null) {

            $path = self::getDefaultPath();

        }

        $contents = @file_get_contents($path);

        if ($contents === false) {

            throw new RuntimeException('Unable to load hosts file "' . $path . '"');

        }

        return new self($contents);

    }

    private $contents;

    /**

     * Instantiate new hosts file with the given hosts file contents

     *

     * @param string $contents

     */

    public function __construct($contents)

    {

        // remove all comments from the contents

        $contents = preg_replace('/[ \t]*#.*/', '', strtolower($contents));

        $this->contents = $contents;

    }

    /**

     * Returns all IPs for the given hostname

     *

     * @param string $name

     * @return string[]

     */

    public function getIpsForHost($name)

    {

        $name = strtolower($name);

        $ips = array();

        foreach (preg_split('/\r?\n/', $this->contents) as $line) {

            $parts = preg_split('/\s+/', $line);

            $ip = array_shift($parts);

            if ($parts && array_search($name, $parts) !== false) {

                // remove IPv6 zone ID (`fe80::1%lo0` => `fe80:1`)

                if (strpos($ip, ':') !== false && ($pos = strpos($ip, '%')) !== false) {

                    $ip = substr($ip, 0, $pos);

                }

                if (@inet_pton($ip) !== false) {

                    $ips[] = $ip;

                }

            }

        }

        return $ips;

    }

    /**

     * Returns all hostnames for the given IPv4 or IPv6 address

     *

     * @param string $ip

     * @return string[]

     */

    public function getHostsForIp($ip)

    {

        // check binary representation of IP to avoid string case and short notation

        $ip = @inet_pton($ip);

        if ($ip === false) {

            return array();

        }

        $names = array();

        foreach (preg_split('/\r?\n/', $this->contents) as $line) {

            $parts = preg_split('/\s+/', $line, null, PREG_SPLIT_NO_EMPTY);

            $addr = array_shift($parts);

            // remove IPv6 zone ID (`fe80::1%lo0` => `fe80:1`)

            if (strpos($addr, ':') !== false && ($pos = strpos($addr, '%')) !== false) {

                $addr = substr($addr, 0, $pos);

            }

            if (@inet_pton($addr) === $ip) {

                foreach ($parts as $part) {

                    $names[] = $part;

                }

            }

        }

        return $names;

    }

}