cloudscope/src/cidr.js

A Node.js library to detect whether an IP address belongs to a cloud provider. Supports AWS, Azure, GCP, Oracle, IBM, DigitalOcean, Linode, Exoscale, and Vultr. Fetches and normalizes CIDR ranges, then lets you check IPv4 and IPv6 addresses efficiently.

const ipaddr = require('ipaddr.js');

function ipInCidr(ip, cidr) {
  try {
    const addr = ipaddr.parse(ip);
    const [rangeAddr, prefixLen] = ipaddr.parseCIDR(cidr);
    if (addr.kind() !== rangeAddr.kind()) return false;
    return addr.match([rangeAddr, prefixLen]);
  } catch {
    return false;
  }
}

module.exports = { ipInCidr };