Given A List Of Ranges How Can We Find If The Given Value Exist In That List Of Ranges In Node Js
I have aset of ip ranges and i need to find if the ip given by the user exists between the given list of ip ranges . This is in continuation to this question How to check if a giv
Solution 1:
Ive observated that many of your ips look like this:
123.123.123.0 - 123.123.123.255
So to filter them out, we just need to block every ip starting with:
123.123.123
Now there are just 16E6 ip ranges left for being blocked. However you will probably block just a few of them, which gives us the ability to store that in a Set. A bit of code:
const blockedRange = new Set();
function IPtoBlock(ip){
return ip.split(".").slice(0,3).join(".");
}
//to block an ip range ( if youve got one ip of it):
blockedRange.add( IPtoBlock("192.168.2.48") );
//to check for an ip
blockedRange.has( IPtoBlock( someip ));
So now there are just a few ranges that are not a block, like:
5.44.26.144 - 5.44.26.159
But hey, just 15 ips, which we can add to a ban by ip list:
const blockedIPs = newSet();
functionNumtoIP(num){
return (num+"").split("").reduce((res,char,i) =>
res + (!i || i%3?"":".") + (char === "0"?"":char)
,"");
}
functionaddRange(start,end){
start = IPtoNum(start);
end = IPtoNum(end);//include from last answerfor(var i = start; i <= end; i++){
blockedIPs.add( NumtoIP( i ) );
}
}
So when iterating over our range list we can seperate:
ranges.forEach(([min,max]) => {
if( min.substr(-1) === "0" && max.substr(-3) === "255" ){
blockedRange.add( IPtoBlock( min ) );
}else{
addRange(min, max);
}
});
To check if an ip fails the check
function isBlocked(ip){
return blockedIPs.has(ip) && blockedRange.has( IPtoBlock(ip) );
}
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