IPv6地址验证和规范化 [英] IPv6 address validation and canonicalization

问题描述

您使用了哪些库？它们彼此之间有多兼容？或者您是否编写了自己的解析例程？

What libs have you used for that? How compatible are they with one another? Or did you write your own parsing routine?

我对Java，C ++，Python和JavaScript的相互兼容的实现特别感兴趣，它们支持：

I'm particularly interested in mutually-compatible implementations for Java, C++, Python, and JavaScript, which support:

• 零压缩（ :: ）


• IPv4映射地址（ :: ffff：123.45.67.89 ）


• 规范化（包括简写形式，适用于人类）可读性）


• CIDR风格的网络掩码（最后是 / 64 ）

• zero compression ("::")
• IPv4-mapped addresses ("::ffff:123.45.67.89")
• canonicalization (including to the short form, for human readability)
• CIDR-style netmasks (like "/64" at the end)

推荐答案

在POSIX系统上，您可以使用 inet_pton 和 inet_ntop 组合进行规范化。您仍然需要进行自己的CIDR解析。幸运的是，我认为IPv6的唯一有效CIDR语法是/ number_of_bits表示法，因此相当容易。

On POSIX systems you can use inet_pton and inet_ntop in combination to do canonicalization. You will still have to do your own CIDR parsing. Fortunately, I believe the only valid CIDR syntax for IPv6 is the /number_of_bits notation, so that's fairly easy.

您将遇到的另一个问题是缺乏对接口规格。对于链接本地地址，您将在末尾看到诸如％eth0 之类的内容，以指定它们本地的链接。 getaddrinfo 会解析但 inet_pton 不会。

The other issue you will run into is the lack of support for interface specifications. For link-local addresses, you will see things like %eth0 on the end to specify what link they are local too. getaddrinfo will parse that but inet_pton won't.

您可以采用的一种策略是使用 getaddrinfo 来解析和 inet_ntop 进行规范化。

One strategy you could go for is using getaddrinfo to parse and inet_ntop to canonicalize.

getaddrinfo 适用于Windows。 inet_pton 和 inet_ntop 不是。幸运的是，编写代码来生成规范格式的IPv6地址并不困难。它将需要两次通过，因为0压缩的规则是首先出现的最大0字符串。 IPv4表单（即 :: 127.0.0.1 ）仅用于 :: IPv4 或 :: ffff：IPv4 。

getaddrinfo is available for Windows. inet_pton and inet_ntop aren't. Fortunately, it isn't too hard to write code to produce a canonical form IPv6 address. It will require two passes though because the rule for 0 compression is the biggest string of 0s that occurs first. Also IPv4 form (i.e. ::127.0.0.1) is only used for ::IPv4 or ::ffff:IPv4.

我没有要测试的Windows机器，但是从文档中可以看出Windows上的Python支持<在套接字模块中code> inet_pton 和 inet_ntop 。

I have no Windows machine to test with, but from the documentation it appears that Python on Windows supports inet_pton and inet_ntop in its socket module.

编写你的生成规范形式的自己的例程可能并不是一个坏主意，因为即使你的规范形式与其他人不一样，只要它有效，其他人就可以解析它。但我绝不会在解析 IPv6地址上编写您自己的例程。

Writing your own routine for producing a canonical form might not be a bad idea, since even if your canonical form isn't the same as everybody else's, as long as it's valid other people can parse it. But I would under no circumstances write a routine of your own to parse IPv6 addresses.

我的建议对Python，C和C ++。我对如何用Java或Javascript解决这个问题知之甚少。

My advice above is good for Python, C, and C++. I know little or nothing about how to solve this problem in Java or Javascript.

EDIT ：我一直在研究getaddrinfo及其对应的getnameinfo 。这些几乎在所有方面都优于 inet_pton 和 inet_ntop 。它们是线程安全的，你可以传递它们的选项（ AI_NUMERICHOST 在 getaddrinfo 的情况下，以及 NI_NUMERCHOST 在 getnameinfo 的情况下），以防止他们进行任何类型的DNS查询。它们的界面有点复杂，让我想起了某些方面丑陋的Windows界面，但要弄清楚要通过哪些选项来获得你想要的东西是相当容易的。我衷心地推荐他们两个。

EDIT: I have been examining getaddrinfo and its counterpart, getnameinfo. These are in almost all ways better than inet_pton and inet_ntop. They are thread safe, and you can pass them options (AI_NUMERICHOST in getaddrinfo's case, and NI_NUMERCHOST in getnameinfo's case) to keep them from doing any kind of DNS queries. Their interface is a little complex and reminds me of an ugly Windows interface in some respects, but it's fairly easy to figure out what options to pass to get what you want. I heartily recommend them both.

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