@nictool/dns-resource-record/rr/srv.js

DNS Resource Records

import RR from '../rr.js'
import * as TINYDNS from '../lib/tinydns.js'

export default class SRV extends RR {
  constructor(opts) {
    super(opts)
  }

  /****** Resource record specific setters   *******/
  setPriority(val) {
    this.is16bitInt('SRV', 'priority', val)

    this.set('priority', val)
  }

  setPort(val) {
    this.is16bitInt('SRV', 'port', val)

    this.set('port', val)
  }

  setWeight(val) {
    this.is16bitInt('SRV', 'weight', val)

    this.set('weight', val)
  }

  setTarget(val) {
    if (!val) this.throwHelp(`SRV: target is required`)

    if (this.isIPv4(val) || this.isIPv6(val))
      this.throwHelp(`SRV: target must be a FQDN`)

    this.isFullyQualified('SRV', 'target', val)
    this.isValidHostname('SRV', 'target', val)

    // RFC 4034: letters in the DNS names are lower cased
    this.set('target', val.toLowerCase())
  }

  getDescription() {
    return 'Service'
  }

  getRdataFields(arg) {
    return ['priority', 'weight', 'port', 'target']
  }

  getRFCs() {
    return [2782]
  }

  getTypeId() {
    return 33
  }

  /******  IMPORTERS   *******/
  fromTinydns(opts) {
    const str = opts.tinyline
    let fqdn, addr, port, pri, weight, ttl, ts, loc, n, rdata

    if (str[0] === 'S') {
      // patched tinydns with S records
      ;[fqdn, addr, port, pri, weight, ttl, ts, loc] = str
        .substring(1)
        .split(':')
    } else {
      // tinydns generic record format
      ;[fqdn, n, rdata, ttl, ts, loc] = str.substring(1).split(':')
      if (n != 33) this.throwHelp('SRV fromTinydns: invalid n')

      pri = TINYDNS.octalToUInt16(rdata.substring(0, 8))
      weight = TINYDNS.octalToUInt16(rdata.substring(8, 16))
      port = TINYDNS.octalToUInt16(rdata.substring(16, 24))
      addr = TINYDNS.unpackDomainName(rdata.substring(24))[0]
    }

    return new SRV({
      owner: this.fullyQualify(fqdn),
      ttl: parseInt(ttl, 10),
      type: 'SRV',
      priority: parseInt(pri, 10),
      weight: parseInt(weight, 10),
      port: parseInt(port, 10),
      target: this.fullyQualify(addr),
      timestamp: ts,
      location: loc !== '' && loc !== '\n' ? loc : '',
    })
  }

  fromBind(opts) {
    // test.example.com  3600  IN  SRV Priority Weight Port Target
    const [owner, ttl, c, type, pri, weight, port, target] =
      opts.bindline.split(/\s+/)
    return new SRV({
      owner: owner,
      ttl: parseInt(ttl, 10),
      class: c,
      type: type,
      priority: parseInt(pri, 10),
      weight: parseInt(weight, 10),
      port: parseInt(port, 10),
      target: target,
    })
  }

  /******  EXPORTERS   *******/

  toTinydns() {
    let rdata = ''

    for (const e of ['priority', 'weight', 'port']) {
      rdata += TINYDNS.UInt16toOctal(this.get(e))
    }

    rdata += TINYDNS.packDomainName(this.get('target'))

    return this.getTinydnsGeneric(rdata)
  }
}