File size: 2,220 Bytes
4e23b01 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 | import net from 'node:net';
export type BindClass = 'loopback' | 'lan' | 'public';
export interface ClassifyOptions {
readonly bindClass?: 'lan' | 'public';
}
function ipv4ToInt(ip: string): number {
const [a, b, c, d] = ip.split('.');
return (
(((Number(a) << 24) >>> 0) +
((Number(b) << 16) >>> 0) +
((Number(c) << 8) >>> 0) +
(Number(d) >>> 0)) >>>
0
);
}
function ipv4InCidr(ip: string, base: string, prefix: number): boolean {
const mask = prefix === 0 ? 0 : (0xffffffff << (32 - prefix)) >>> 0;
return ((ipv4ToInt(ip) & mask) >>> 0) === ((ipv4ToInt(base) & mask) >>> 0);
}
function expandV6(host: string): readonly string[] | null {
const lower = host.toLowerCase();
if (lower.includes('::')) {
const halves = lower.split('::');
const leftRaw = halves[0] ?? '';
const rightRaw = halves[1] ?? '';
const left = leftRaw.length > 0 ? leftRaw.split(':') : [];
const right = rightRaw.length > 0 ? rightRaw.split(':') : [];
const missing = 8 - (left.length + right.length);
if (missing < 0) return null;
return [...left, ...Array<string>(missing).fill('0'), ...right];
}
const parts = lower.split(':');
return parts.length === 8 ? parts : null;
}
function isLinkLocalV6(host: string): boolean {
const groups = expandV6(host);
if (groups === null) return false;
const first = Number.parseInt(groups[0] ?? '', 16);
return first >= 0xfe80 && first <= 0xfebf;
}
export function classify(host: string, opts?: ClassifyOptions): BindClass {
if (host === '' || host === '0.0.0.0' || host === '::') {
return opts?.bindClass ?? 'public';
}
if (host === 'localhost') {
return 'loopback';
}
const family = net.isIP(host);
if (family === 4) {
if (host.startsWith('127.')) return 'loopback';
if (ipv4InCidr(host, '10.0.0.0', 8)) return 'lan';
if (ipv4InCidr(host, '172.16.0.0', 12)) return 'lan';
if (ipv4InCidr(host, '192.168.0.0', 16)) return 'lan';
if (ipv4InCidr(host, '169.254.0.0', 16)) return 'lan';
return 'public';
}
if (family === 6) {
if (host.toLowerCase() === '::1') return 'loopback';
if (isLinkLocalV6(host)) return 'lan';
return 'public';
}
return 'public';
}
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