通过 PHP 缩短以 0 结尾的 IPv6 地址答案

【问题标题】：Shortening an IPv6 address ending in 0's via PHP通过 PHP 缩短以 0 结尾的 IPv6 地址
【发布时间】：2016-04-25 07:39:07
【问题描述】：

我正在使用an IPv6 class found on GitHub 进行一些 IP 操作，但我注意到缩短某些地址存在问题，通常以 0 结尾。

当我输入地址2001::6dcd:8c74:0:0:0:0时，结果是2001::6dcd:8c74::::。

$address = '2001::6dcd:8c74:0:0:0:0';
// Check to see if address is already compacted
if (strpos($address, '::') === FALSE) {
    $parts = explode(':', $address);
    $new_parts = array();
    $ignore = FALSE;
    $done = FALSE;

    for ($i = 0; $i < count($parts); $i++) {
        if (intval(hexdec($parts[$i])) === 0 && $ignore == FALSE && $done == FALSE) {
            $ignore = TRUE;
            $new_parts[] = '';
            if ($i == 0) {
                $new_parts = '';
            }
        } else if (intval(hexdec($parts[$i])) === 0 && $ignore == TRUE && $done == FALSE) {
            continue;
        } else if (intval(hexdec($parts[$i])) !== 0 && $ignore == TRUE) {
            $done = TRUE;
            $ignore = FALSE;
            $new_parts[] = $parts[$i];
        } else {
            $new_parts[] = $parts[$i];
        }
    }

    // Glue everything back together
    $address = implode(':', $new_parts);

}

// Remove the leading 0's
$new_address = preg_replace("/:0{1,3}/", ":", $address);

// $this->compact = $new_address;

// return $this->compact;
echo $new_address; // Outputs: 2001::6dcd:8c74::::

【问题讨论】：

标签： php ip-address ipv6

【解决方案1】：

如果没有底部的问题行，您会得到2001::6dcd:8c74:0:0:0:0。现在，在所有前导 0 被替换之前，该函数在删除所有前导 0 之前检查地址是否以 :0 结尾。

if (substr($address, -2) != ':0') {
    $new_address = preg_replace("/:0{1,3}/", ":", $address);
} else {
    $new_address = $address;
}

添加了另一项检查以防止其他可能的有效 IPv6 地址格式错误。

if (isset($new_parts)) {
    if (count($new_parts) < 8 && array_pop($new_parts) == '') {
        $new_address .= ':0';
    }
}

新的完整功能如下所示：

// Check to see if address is already compacted
if (strpos($address, '::') === FALSE) {
    $parts = explode(':', $address);
    $new_parts = array();
    $ignore = FALSE;
    $done = FALSE;

    for ($i = 0; $i < count($parts); $i++) {
        if (intval(hexdec($parts[$i])) === 0 && $ignore == FALSE && $done == FALSE) {
            $ignore = TRUE;
            $new_parts[] = '';
            if ($i == 0) {
                $new_parts = '';
            }
        } else if (intval(hexdec($parts[$i])) === 0 && $ignore == TRUE && $done == FALSE) {
            continue;
        } else if (intval(hexdec($parts[$i])) !== 0 && $ignore == TRUE) {
            $done = TRUE;
            $ignore = FALSE;
            $new_parts[] = $parts[$i];
        } else {
            $new_parts[] = $parts[$i];
        }
    }

    // Glue everything back together
    $address = implode(':', $new_parts);

}
// Check to see if this ends in a shortened :0 before replacing all
// leading 0's
if (substr($address, -2) != ':0') {
    // Remove the leading 0's
    $new_address = preg_replace("/:0{1,3}/", ":", $address);
} else {
    $new_address = $address;
}
// Since new_parts isn't always set, check to see if it's set before
// trying to fix possibly broken shortened addresses ending in 0.
// (Ex: Trying to shorten 2001:19f0::0 will result in unset array)
if (isset($new_parts)) {
    // Some addresses (Ex: starting addresses for a range) can end in
    // all 0's resulting in the last value in the new parts array to be
    // an empty string.  Catch that case here and add the remaining :0
    // for a complete shortened address.
    if (count($new_parts) < 8 && array_pop($new_parts) == '') {
        $new_address .= ':0';
    }
}

// $this->compact = $new_address;

// return $this->compact;
echo $new_address; // Outputs: 2001::6dcd:8c74:0:0:0:0

这不是最干净的解决方案，并且可能在其逻辑中存在漏洞，具体取决于地址是什么。如果我发现任何其他问题，我会更新这个问题/答案。

【讨论】：

【解决方案2】：

要压缩 ipv6 地址，请使用 php 函数 inet_ntop 和 inet_pton 进行格式化，将 ipv6 转换为二进制并返回。

ipv6 示例 - 2001::6dcd:8c74:0:0:0:0

测试使用：

echo inet_ntop(inet_pton('2001::6dcd:8c74:0:0:0:0'));

输出：2001:0:6dcd:8c74::

【讨论】：