IPv6 address validation and canonicalization [closed]

Answer 1

For Python, the best solution might be IPy (http://pypi.python.org/pypi/IPy/0.51)

Answer 2

I wrote javascript-ipv6 for this very purpose. It currently powers v6decode.com.

Here's a short example of the API:

var address = new v6.Address("::ffff:7b2d:4359/64");

if (address.isValid()) {
   // Do something if the address is valid
}

console.log(address.correctForm());         // "::ffff:7b2d:4359"
console.log(address.canonicalForm());       // "0000:0000:0000:0000:0000:ffff:7b2d:4359"
console.log(address.v4Form());              // "::ffff:123.45.67.89"
console.log(address.subnetMask);            // "64"
console.log(address.possibleAddresses(96)); // "4,294,967,296"

Answer 3

i simply went through adhoc approach to check the validity of IPV4 and IPV6 both addressing scheme:here is my code ... corrections are always welcome in my code. and pardon me if my solution is wrong.

#include <cstdio>
#include <iostream>
#include <vector>
#include <stack>
#include <algorithm>
#include <sstream>
#include <utility>
#include <cmath>
#include <cstring>
#include <map>
#include <queue>
#include <limits.h>
using namespace std;
bool check6(string s)
{
    for(int i=0;i<s.length();i++)
    {
       if((s[i] < '0' || s[i] > '9') && (s[i] < 'a' || s[i]> 'f') && 
           (s[i] < 'A' || s[i] > 'F'))                       
          return false;
    }
    return true;
}
   bool check4(string s)
   {
      for(int i=0; i< s.length(); i++)
      {
       if(!(s[i]>= '0' && s[i] <= '9'))
          return false;
      }
     stringstream ss(s);
      int e;
      ss >> e;
     if( e < 0 || e > 255 )
      return false;
     else
      return true;
   }

int main()
{
  string s;
  cin>>s;
  vector<string> v;
  int i=0;
  int d=0;
  if((s.find(":")!=std::string::npos || 
         s.find("::")!=std::string::npos)&&  
     s.find(".")==std::string::npos)     
   {
      int x=0;
      while(i< s.length())
      {
          string s1 ="";
          while(i< s.length() && s[i]!= ':')
          {
             s1+= s[i];
             i++;
          }
         if(s1!="")
         v.push_back(s1);
         if((i+1)< s.length() && s[i]==':' && s[i+1]==':')
            x++;
         i++;
         if(i< s.length())
         d++;
     }
      if(x > 1 || d > 7 || v.size() > 8 || (x==1 && d >6))
      {
         cout<<"Not Valid"<<endl;
         return 0;
      }
      else if(d > 2 && v.size() ==0)
      {

         cout<<"Not Valid"<<endl;
         return 0;
      }
      else
      {
         for(int i=0;i< v.size();i++)
         {
             if((v[i]).length() > 4)
             {
                    cout<<"Not Valid"<<endl;
                 return 0;
              }
             else
             {
                if(!check6(v[i]))
                {

                    cout<<"Not Valid"<<endl;
                    return 0;
                }
            }
         }
         cout<<"Valid Ipv6"<<endl;
          return 0;
      }
   }
else if(s.find(":")==std::string::npos && s.find(".")!=std::string::npos)
{
    while(i< s.length())
    {
        string s1="";
        while( i< s.length() && s[i]!='.')
        {
            s1+=s[i];
            i++;
        }
        i++;
        if(i< s.length())
        d++;
        v.push_back(s1);
    }
    if(d > 4 || v.size()> 4)
    {
        cout<<"Not Valid"<<endl;
        return 0;
    }
    else
    {
        for(int i=0;i<v.size();i++)
        {
            if((v[i]).length() > 3)
            {
                cout<<"Not Valid"<<endl;
                return 0;
            }
            if(!check4(v[i]))
            {
                cout<<"Not Valid"<<endl;
                return 0;
            }
        }   
    }
    cout<<"Valid Ipv4"<<endl;
    return 0;
}

        cout<<"Not Valid"<<endl;

return 0;

}

Answer 4

It's too bad Python 3.1 lost the ipaddr lib.

It's still available as a third-party library: py-ipaddr available on PyPI.

Compression

>>> ipaddr.IPv6Address('0:0::0:1').compressed
'::1'

IPv4 mapping

>>> ipaddr.IPv6Address('::ffff:123.45.67.89').ipv4_mapped
IPv4Address('123.45.67.89')

CIDR

>>> ipaddr.IPv6Network('::ffff:123.45.67.89/128')
IPv6Network('::ffff:7b2d:4359/128')

Answer 5

In Java, the Guava library has utility functions for validating IPv6 (and IPv4) in the com.google.common.net.InetAddresses class. http://goo.gl/RucRU

Answer 6

getaddrinfo already returns the shortest textual form, so if you have the longer form you can canonicalize by running through getaddrinfo again. Example Python,

import sys, socket;
result = socket.getaddrinfo('0:0::0:1', None);
print "family:%i socktype:%i proto:%i canonname:%s sockaddr:%s"%result[0];

Outputs the following,

family:10 socktype:1 proto:6 canonname: sockaddr:('::1', 0, 0, 0)

IPv6 CIDR blocks don't appear to be well documented or defined so I wrote my own inet6_network implementation to handle that (C99).