IPv6地址的正则表达式 [英] regular expression for IPv6 addresses

问题描述

我有一个如下所示的IPv6地址正则表达式

I have a regular expression for IPv6 addresses as given below

IPV4ADDRESS      [ \t]*(([[:digit:]]{1,3}"."){3}([[:digit:]]{1,3}))[ \t]*
x4               ([[:xdigit:]]{1,4})
xseq             ({x4}(:{x4}){0,7})
xpart            ({xseq}|({xseq}::({xseq}?))|::{xseq})
IPV6ADDRESS      [ \t]*({xpart}(":"{IPV4ADDRESS})?)[ \t]*

这是正确的所有IPv6地址格式，包括

It is correctly all formats of IPv6 addresses including

1) non-compressed IPv6 addresses
2) compressed IPv6 addresses
3) IPv6 addresses in legacy formats.(supporting IPv4)

传统格式的IPv6地址的理想示例是

Ideal examples of IPv6 addresses in legacy formats would be

2001:1234::3210:5.6.7.8

     OR
2001:1234:1234:5432:4578:5678:5.6.7.8

As you can see above there are 10 groups separated by either `":" or ".".`

与普通IPv6地址中的8个组相反.这是因为最后4个组用"分隔.应该压缩为IPv6地址的最低有效32位.因此，我们需要10个组来满足128位.

As opposed to 8 groups in normal IPv6 addresses.This is because the last 4 groups that are separated by `"." should be compressed into least significant 32-bits of the IPv6 addresses.Hence we need 10 groups to satisfy 128 bits.

但是，如果我使用以下地址格式

However If I use the following address format

   2001:1234:4563:3210:5.6.7.8

在此，每个以:"分隔的组代表16位.最后四个组以."分隔.代表8位.总位数为64 + 32 = 96位.缺少32位

Here each group separated by ":" represents 16-bits.the last four groups separted by "." represents 8 bits.Total number of bits is 64 + 32 = 96 bits.32 bits are missing

正则表达式将其接受为有效的IPv6地址格式.我无法弄清楚如何修复正则表达式以丢弃此类值.我们非常感谢您的帮助.

The regular expression is accepting it as a valid IPv6 address format.I am unable to figure out how to fix the regular expression to discard such values.Any help is highly appreciated.

推荐答案

以下是 RFC 5954 中确认:

Here's the grammar for IPv6 addresses as given in RFC 3986 and subsequently affirmed in RFC 5954:

 IPv6address   =                             6( h16 ":" ) ls32
                /                       "::" 5( h16 ":" ) ls32
                / [               h16 ] "::" 4( h16 ":" ) ls32
                / [ *1( h16 ":" ) h16 ] "::" 3( h16 ":" ) ls32
                / [ *2( h16 ":" ) h16 ] "::" 2( h16 ":" ) ls32
                / [ *3( h16 ":" ) h16 ] "::"    h16 ":"   ls32
                / [ *4( h16 ":" ) h16 ] "::"              ls32
                / [ *5( h16 ":" ) h16 ] "::"              h16
                / [ *6( h16 ":" ) h16 ] "::"

 h16           = 1*4HEXDIG
 ls32          = ( h16 ":" h16 ) / IPv4address
 IPv4address   = dec-octet "." dec-octet "." dec-octet "." dec-octet
 dec-octet     = DIGIT                 ; 0-9
                / %x31-39 DIGIT         ; 10-99
                / "1" 2DIGIT            ; 100-199
                / "2" %x30-34 DIGIT     ; 200-249
                / "25" %x30-35          ; 250-255

以此为基础，我们可以为IPv6地址构建符合标准的正则表达式.

Using this, we can build a standards-compliant regular expression for IPv6 addresses.

dec_octet      ([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])
ipv4address    ({dec_octet}"."){3}{dec_octet}
h16            ([[:xdigit:]]{1,4})
ls32           ({h16}:{h16}|{ipv4address})
ipv6address    (({h16}:){6}{ls32}|::({h16}:){5}{ls32}|({h16})?::({h16}:){4}{ls32}|(({h16}:){0,1}{h16})?::({h16}:){3}{ls32}|(({h16}:){0,2}{h16})?::({h16}:){2}{ls32}|(({h16}:){0,3}{h16})?::{h16}:{ls32}|(({h16}:){0,4}{h16})?::{ls32}|(({h16}:){0,5}{h16})?::{h16}|(({h16}:){0,6}{h16})?::)

免责声明:未经测试.

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