如何计算下一个ipv6地址？

Question

我被困在一个希望很简单的任务上:我想要得到下一个ip地址。

以下是我的一些测试：

    //$binaryIp = inet_pton('192.168.1.1');
    $binaryIp = inet_pton('2001:cdba::1');

    $verySimple = inet_ntop(
        $binaryIp++
    );
    var_dump($verySimple); //'2001:cdba::1'

    $simpleMaths = inet_ntop(
        $binaryIp + inet_pton('0.0.0.1')
    );
    var_dump($simpleMaths); //inet_ntop(): Invalid in_addr value

    $aLittleBitOfSuccess = long2ip(
        ip2long(inet_ntop($binaryIp)) + 1
    );
    var_dump($aLittleBitOfSuccess); //'0.0.0.1' but with IPv4 '192.168.1.2'

好吧，在此之前，很明显，我的尝试更多的是无稽之谈，而不是对我的问题的真正宣泄，但我还能尝试什么呢？我搜索了网页，找到了一些子网计算之类的解决方案，但没有简单的加减。

我的下一个尝试是将字符串从inet_ntop()中分离出来，然后篡改十六进制值，但是必须有一个简单的解决方案才能将1添加到in6_addr中！

Answer 1

我选择了巫术，并做了这个功能：

protected function binaryIncrement($binaryIp, $increment = 1) {

    //inet_pton creates values where each "character" is one ip-address-byte
    //we are splitting the string so we can handle every byte for itselve.
    $binaryIpArrayIn = str_split($binaryIp);
    $binaryIpArrayOut = array();
    $carry = 0 + $increment;
    //reverse array because our following addition is done from right to left.
    foreach (array_reverse($binaryIpArrayIn) as $binaryByte) {
        //transforming on byte from our ip address to decimal
        $decIp = hexdec(bin2hex($binaryByte));
        $tempValue = $decIp + $carry;
        $tempValueHex = dechex($tempValue);
        //check if we have to deal with a carry
        if (strlen($tempValueHex) > 2) {
            //split $tempValueHex in carry and result
            //str_pad because hex2bin only accepts even character counts
            $carryHex = str_pad(substr($tempValueHex,0,1),2,'0',STR_PAD_LEFT);
            $tempResultHex = str_pad(substr($tempValueHex,1,2),2,'0',STR_PAD_LEFT);
            $carry = hexdec($carryHex);
        } else {
            $carry = 0;
            $tempResultHex = str_pad($tempValueHex,2,'0',STR_PAD_LEFT);
        }
        //fill our result array
        $binaryIpArrayOut[] = hex2bin($tempResultHex);
    }
    //we have to reverse our arry back to normal order and building a string
    $binaryIpOut = implode(array_reverse($binaryIpArrayOut));

    return $binaryIpOut;
}

$binaryIpV6In = inet_pton('2001:cdba::FFFF');
$binaryIpV6Out = $this->binaryIncrement($binaryIpV6In);
var_dump(inet_ntop($binaryIpV6Out));
$binaryIpV4In = inet_pton('192.168.1.1');
$binaryIpV4Out = $this->binaryIncrement($binaryIpV4In, 256);
var_dump(inet_ntop($binaryIpV4Out));

这样，我就可以对IPv4和IPv6使用相同的方法。

Answer 2

除了少数例外，IPv6地址被分为两个64位部分:网络/子网和接口ID。您应该对接口ID的64位感兴趣。

最简单的方法是将地址解析为两个64位无符号整数，增加接口ID，然后将这两个部分重新组合成128位地址。