server/helpers/dns.ts

   1 import { lookup } from 'dns'
   2 import { parse as parseIP } from 'ipaddr.js'
   3
   4 function dnsLookupAll (hostname: string) {
   5   return new Promise<string[]>((res, rej) => {
   6     lookup(hostname, { family: 0, all: true }, (err, adresses) => {
   7       if (err) return rej(err)
   8
   9       return res(adresses.map(a => a.address))
  10     })
  11   })
  12 }
  13
  14 async function isResolvingToUnicastOnly (hostname: string) {
  15   const addresses = await dnsLookupAll(hostname)
  16
  17   for (const address of addresses) {
  18     const parsed = parseIP(address)
  19
  20     if (parsed.range() !== 'unicast') return false
  21   }
  22
  23   return true
  24 }
  25
  26 export {
  27   dnsLookupAll,
  28   isResolvingToUnicastOnly
  29 }