MAP-E のアドレス変換器（PHP >= 7.1.0）

v6plus.php

<?php

// https://qiita.com/mpyw/items/0fdffd3c70b3abd802f5
function array_group_by_range(array $array, $separator = '-')
{
    sort($array, SORT_NUMERIC);
    $pairs = $ranges = [];
    foreach (array_values(array_unique($array, SORT_NUMERIC)) as $i => $v) {
        $pairs[$v - $i][isset($pairs[$v - $i])] = $v;
    }
    foreach ($pairs as $pair) {
        $ranges[] = implode($separator, $pair);
    }
    return $ranges;
}

// MAP-E IPv4
function calculate_mapped_ipv4(string $ipv6)
{
    static $address_map = [
        '240b:10' => '106.72',
        '240b:12' => '14.8',
        '240b:250' => '14.10',
        '240b:252' => '14.12',
    ];

    preg_match('/^(240b:[a-f0-9]{1,4}):([a-f0-9]{2})([a-f0-9]{2})/', $ipv6, $matches);
    [ , $key, $high_1, $high_2 ] = $matches;

    return sprintf('%s.%s.%s', $address_map[$key], intval($high_1, 16), intval($high_2, 16));
}

// CE IPv6
function calculate_ce_ipv6(string $ipv6)
{
    preg_match('/^(240b:[a-f0-9]{1,4}):([a-f0-9]{1,4}):([a-f0-9]{1,4})/', $ipv6, $matches);
    [ , $key, $high, $low ] = $matches;

    $ipv4 = sprintf('%x:%x%02x:%02x', ...array_map('intval', explode('.', calculate_mapped_ipv4($ipv6))));
    return sprintf('%s:%s:%s:%s00:%s', $key, $high, $low, $ipv4, $low);
}

// MAP-E Ports
function calculate_mapped_ports(string $ipv6)
{
    preg_match('/^240b:[a-f0-9]{1,4}:([a-f0-9]{2})/', $ipv6, $matches);
    [ , $psid ] = $matches;

    return array_merge(...array_map(function ($port) use ($psid) {
        [ $high, $low ] = str_split(sprintf('%02x', $port));
        return [
            sprintf('%02x', $port) => intval(sprintf('%s%s%s', $high, $psid, $low), 16),
        ];
    }, range(0x10, 0xff)));
}

echo 'IPv6: ';
$ipv6 = strtolower(rtrim(fgets(STDIN)));

echo "\n";
echo "Mapped IPv4:\n  " . calculate_mapped_ipv4($ipv6) . "\n";
echo "CE IPv6:\n  " . calculate_ce_ipv6($ipv6) . "\n";
echo "Mapped ports:\n  " . implode("\n  ", array_group_by_range(calculate_mapped_ports($ipv6))) . "\n";