Hadn't thought about it that way before. This was a useful bit of info, thanks. -Blake On Thu, Nov 29, 2012 at 8:55 AM, William Herrin <bill@herrin.us> wrote:
On Thu, Nov 29, 2012 at 9:01 AM, Ray Soucy <rps@maine.edu> wrote:
You should store IPv6 as a pair of 64-bit integers. While PHP lacks the function set to do this on its own, it's not very difficult to do.
Hi Ray,
I have to disagree. In your SQL database you should store addresses as a fixed length character string containing a zero-padded hexadecimal representation of the IPv4 or IPv6 address with A through F forced to the consistent case of your choice. Expand :: and optionally strip the colons entirely. If you want to store a block of addresses, store it as two character strings: start and end of the range.
Bytes are cheap and query simplicity is important. Multi-element indexes are messy and the code to manage an array of integers is messier than managing a character string in most programming languages. memcmp() that integer array for less or greater than? Not on a little endian machine!
Here are a set of functions I wrote a while back to do just that (though I admit I should spend some time to try and make it more elegant and I'm not sure it's completely up to date compared to my local copy ... I would love some eyes on it to make some improvements).
If we're plugging our code, give my public domain libeasyv6 a try. It eases entry into dual stack programming for anyone used to doing gethostbyname followed by a blocking connect(). Just do a connectbyname() with the hostname or textual IP address, the port, a timeout and null options. The library takes care of finding a working IPv4 or IPv6 address for the host and connecting to it in a timely manner.
http://bill.herrin.us/freebies/
Currently Linux only but if you're willing to lose timeout control on the DNS lookup you can replace getaddrinfo_a() with standard getaddrinfo() and the code should run anywhere.
Regards, Bill Herrin
-- William D. Herrin ................ herrin@dirtside.com bill@herrin.us 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004