Index: frontend/node_modules/dns-packet/index.js
===================================================================
--- frontend/node_modules/dns-packet/index.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/dns-packet/index.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,1761 @@
+'use strict'
+
+const Buffer = require('buffer').Buffer
+const types = require('./types')
+const rcodes = require('./rcodes')
+const opcodes = require('./opcodes')
+const classes = require('./classes')
+const optioncodes = require('./optioncodes')
+const ip = require('@leichtgewicht/ip-codec')
+
+const QUERY_FLAG = 0
+const RESPONSE_FLAG = 1 << 15
+const FLUSH_MASK = 1 << 15
+const NOT_FLUSH_MASK = ~FLUSH_MASK
+const QU_MASK = 1 << 15
+const NOT_QU_MASK = ~QU_MASK
+
+const name = exports.name = {}
+
+name.encode = function (str, buf, offset, { mail = false } = {}) {
+  if (!buf) buf = Buffer.alloc(name.encodingLength(str))
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  // strip leading and trailing .
+  const n = str.replace(/^\.|\.$/gm, '')
+  if (n.length) {
+    let list = []
+    if (mail) {
+      let localPart = ''
+      n.split('.').forEach(label => {
+        if (label.endsWith('\\')) {
+          localPart += (localPart.length ? '.' : '') + label.slice(0, -1)
+        } else {
+          if (list.length === 0 && localPart.length) {
+            list.push(localPart + '.' + label)
+          } else {
+            list.push(label)
+          }
+        }
+      })
+    } else {
+      list = n.split('.')
+    }
+
+    for (let i = 0; i < list.length; i++) {
+      const len = buf.write(list[i], offset + 1)
+      buf[offset] = len
+      offset += len + 1
+    }
+  }
+
+  buf[offset++] = 0
+
+  name.encode.bytes = offset - oldOffset
+  return buf
+}
+
+name.encode.bytes = 0
+
+name.decode = function (buf, offset, { mail = false } = {}) {
+  if (!offset) offset = 0
+
+  const list = []
+  let oldOffset = offset
+  let totalLength = 0
+  let consumedBytes = 0
+  let jumped = false
+
+  while (true) {
+    if (offset >= buf.length) {
+      throw new Error('Cannot decode name (buffer overflow)')
+    }
+    const len = buf[offset++]
+    consumedBytes += jumped ? 0 : 1
+
+    if (len === 0) {
+      break
+    } else if ((len & 0xc0) === 0) {
+      if (offset + len > buf.length) {
+        throw new Error('Cannot decode name (buffer overflow)')
+      }
+      totalLength += len + 1
+      if (totalLength > 254) {
+        throw new Error('Cannot decode name (name too long)')
+      }
+      let label = buf.toString('utf-8', offset, offset + len)
+      if (mail) {
+        label = label.replace(/\./g, '\\.')
+      }
+      list.push(label)
+      offset += len
+      consumedBytes += jumped ? 0 : len
+    } else if ((len & 0xc0) === 0xc0) {
+      if (offset + 1 > buf.length) {
+        throw new Error('Cannot decode name (buffer overflow)')
+      }
+      const jumpOffset = buf.readUInt16BE(offset - 1) - 0xc000
+      if (jumpOffset >= oldOffset) {
+        // Allow only pointers to prior data. RFC 1035, section 4.1.4 states:
+        // "[...] an entire domain name or a list of labels at the end of a domain name
+        // is replaced with a pointer to a prior occurance (sic) of the same name."
+        throw new Error('Cannot decode name (bad pointer)')
+      }
+      offset = jumpOffset
+      oldOffset = jumpOffset
+      consumedBytes += jumped ? 0 : 1
+      jumped = true
+    } else {
+      throw new Error('Cannot decode name (bad label)')
+    }
+  }
+
+  name.decode.bytes = consumedBytes
+  return list.length === 0 ? '.' : list.join('.')
+}
+
+name.decode.bytes = 0
+
+name.encodingLength = function (n) {
+  if (n === '.' || n === '..') return 1
+  return Buffer.byteLength(n.replace(/^\.|\.$/gm, '')) + 2
+}
+
+const string = {}
+
+string.encode = function (s, buf, offset) {
+  if (!buf) buf = Buffer.alloc(string.encodingLength(s))
+  if (!offset) offset = 0
+
+  const len = buf.write(s, offset + 1)
+  buf[offset] = len
+  string.encode.bytes = len + 1
+  return buf
+}
+
+string.encode.bytes = 0
+
+string.decode = function (buf, offset) {
+  if (!offset) offset = 0
+
+  const len = buf[offset]
+  const s = buf.toString('utf-8', offset + 1, offset + 1 + len)
+  string.decode.bytes = len + 1
+  return s
+}
+
+string.decode.bytes = 0
+
+string.encodingLength = function (s) {
+  return Buffer.byteLength(s) + 1
+}
+
+const header = {}
+
+header.encode = function (h, buf, offset) {
+  if (!buf) buf = header.encodingLength(h)
+  if (!offset) offset = 0
+
+  const flags = (h.flags || 0) & 32767
+  const type = h.type === 'response' ? RESPONSE_FLAG : QUERY_FLAG
+
+  buf.writeUInt16BE(h.id || 0, offset)
+  buf.writeUInt16BE(flags | type, offset + 2)
+  buf.writeUInt16BE(h.questions.length, offset + 4)
+  buf.writeUInt16BE(h.answers.length, offset + 6)
+  buf.writeUInt16BE(h.authorities.length, offset + 8)
+  buf.writeUInt16BE(h.additionals.length, offset + 10)
+
+  return buf
+}
+
+header.encode.bytes = 12
+
+header.decode = function (buf, offset) {
+  if (!offset) offset = 0
+  if (buf.length < 12) throw new Error('Header must be 12 bytes')
+  const flags = buf.readUInt16BE(offset + 2)
+
+  return {
+    id: buf.readUInt16BE(offset),
+    type: flags & RESPONSE_FLAG ? 'response' : 'query',
+    flags: flags & 32767,
+    flag_qr: ((flags >> 15) & 0x1) === 1,
+    opcode: opcodes.toString((flags >> 11) & 0xf),
+    flag_aa: ((flags >> 10) & 0x1) === 1,
+    flag_tc: ((flags >> 9) & 0x1) === 1,
+    flag_rd: ((flags >> 8) & 0x1) === 1,
+    flag_ra: ((flags >> 7) & 0x1) === 1,
+    flag_z: ((flags >> 6) & 0x1) === 1,
+    flag_ad: ((flags >> 5) & 0x1) === 1,
+    flag_cd: ((flags >> 4) & 0x1) === 1,
+    rcode: rcodes.toString(flags & 0xf),
+    questions: new Array(buf.readUInt16BE(offset + 4)),
+    answers: new Array(buf.readUInt16BE(offset + 6)),
+    authorities: new Array(buf.readUInt16BE(offset + 8)),
+    additionals: new Array(buf.readUInt16BE(offset + 10))
+  }
+}
+
+header.decode.bytes = 12
+
+header.encodingLength = function () {
+  return 12
+}
+
+const runknown = exports.unknown = {}
+
+runknown.encode = function (data, buf, offset) {
+  if (!buf) buf = Buffer.alloc(runknown.encodingLength(data))
+  if (!offset) offset = 0
+
+  buf.writeUInt16BE(data.length, offset)
+  data.copy(buf, offset + 2)
+
+  runknown.encode.bytes = data.length + 2
+  return buf
+}
+
+runknown.encode.bytes = 0
+
+runknown.decode = function (buf, offset) {
+  if (!offset) offset = 0
+
+  const len = buf.readUInt16BE(offset)
+  const data = buf.slice(offset + 2, offset + 2 + len)
+  runknown.decode.bytes = len + 2
+  return data
+}
+
+runknown.decode.bytes = 0
+
+runknown.encodingLength = function (data) {
+  return data.length + 2
+}
+
+const rns = exports.ns = {}
+
+rns.encode = function (data, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rns.encodingLength(data))
+  if (!offset) offset = 0
+
+  name.encode(data, buf, offset + 2)
+  buf.writeUInt16BE(name.encode.bytes, offset)
+  rns.encode.bytes = name.encode.bytes + 2
+  return buf
+}
+
+rns.encode.bytes = 0
+
+rns.decode = function (buf, offset) {
+  if (!offset) offset = 0
+
+  const len = buf.readUInt16BE(offset)
+  const dd = name.decode(buf, offset + 2)
+
+  rns.decode.bytes = len + 2
+  return dd
+}
+
+rns.decode.bytes = 0
+
+rns.encodingLength = function (data) {
+  return name.encodingLength(data) + 2
+}
+
+const rsoa = exports.soa = {}
+
+rsoa.encode = function (data, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rsoa.encodingLength(data))
+  if (!offset) offset = 0
+
+  const oldOffset = offset
+  offset += 2
+  name.encode(data.mname, buf, offset)
+  offset += name.encode.bytes
+  name.encode(data.rname, buf, offset, { mail: true })
+  offset += name.encode.bytes
+  buf.writeUInt32BE(data.serial || 0, offset)
+  offset += 4
+  buf.writeUInt32BE(data.refresh || 0, offset)
+  offset += 4
+  buf.writeUInt32BE(data.retry || 0, offset)
+  offset += 4
+  buf.writeUInt32BE(data.expire || 0, offset)
+  offset += 4
+  buf.writeUInt32BE(data.minimum || 0, offset)
+  offset += 4
+
+  buf.writeUInt16BE(offset - oldOffset - 2, oldOffset)
+  rsoa.encode.bytes = offset - oldOffset
+  return buf
+}
+
+rsoa.encode.bytes = 0
+
+rsoa.decode = function (buf, offset) {
+  if (!offset) offset = 0
+
+  const oldOffset = offset
+
+  const data = {}
+  offset += 2
+  data.mname = name.decode(buf, offset)
+  offset += name.decode.bytes
+  data.rname = name.decode(buf, offset, { mail: true })
+  offset += name.decode.bytes
+  data.serial = buf.readUInt32BE(offset)
+  offset += 4
+  data.refresh = buf.readUInt32BE(offset)
+  offset += 4
+  data.retry = buf.readUInt32BE(offset)
+  offset += 4
+  data.expire = buf.readUInt32BE(offset)
+  offset += 4
+  data.minimum = buf.readUInt32BE(offset)
+  offset += 4
+
+  rsoa.decode.bytes = offset - oldOffset
+  return data
+}
+
+rsoa.decode.bytes = 0
+
+rsoa.encodingLength = function (data) {
+  return 22 + name.encodingLength(data.mname) + name.encodingLength(data.rname)
+}
+
+const rtxt = exports.txt = {}
+
+rtxt.encode = function (data, buf, offset) {
+  if (!Array.isArray(data)) data = [data]
+  for (let i = 0; i < data.length; i++) {
+    if (typeof data[i] === 'string') {
+      data[i] = Buffer.from(data[i])
+    }
+    if (!Buffer.isBuffer(data[i])) {
+      throw new Error('Must be a Buffer')
+    }
+  }
+
+  if (!buf) buf = Buffer.alloc(rtxt.encodingLength(data))
+  if (!offset) offset = 0
+
+  const oldOffset = offset
+  offset += 2
+
+  data.forEach(function (d) {
+    buf[offset++] = d.length
+    d.copy(buf, offset, 0, d.length)
+    offset += d.length
+  })
+
+  buf.writeUInt16BE(offset - oldOffset - 2, oldOffset)
+  rtxt.encode.bytes = offset - oldOffset
+  return buf
+}
+
+rtxt.encode.bytes = 0
+
+rtxt.decode = function (buf, offset) {
+  if (!offset) offset = 0
+  const oldOffset = offset
+  let remaining = buf.readUInt16BE(offset)
+  offset += 2
+
+  let data = []
+  while (remaining > 0) {
+    const len = buf[offset++]
+    --remaining
+    if (remaining < len) {
+      throw new Error('Buffer overflow')
+    }
+    data.push(buf.slice(offset, offset + len))
+    offset += len
+    remaining -= len
+  }
+
+  rtxt.decode.bytes = offset - oldOffset
+  return data
+}
+
+rtxt.decode.bytes = 0
+
+rtxt.encodingLength = function (data) {
+  if (!Array.isArray(data)) data = [data]
+  let length = 2
+  data.forEach(function (buf) {
+    if (typeof buf === 'string') {
+      length += Buffer.byteLength(buf) + 1
+    } else {
+      length += buf.length + 1
+    }
+  })
+  return length
+}
+
+const rnull = exports.null = {}
+
+rnull.encode = function (data, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rnull.encodingLength(data))
+  if (!offset) offset = 0
+
+  if (typeof data === 'string') data = Buffer.from(data)
+  if (!data) data = Buffer.alloc(0)
+
+  const oldOffset = offset
+  offset += 2
+
+  const len = data.length
+  data.copy(buf, offset, 0, len)
+  offset += len
+
+  buf.writeUInt16BE(offset - oldOffset - 2, oldOffset)
+  rnull.encode.bytes = offset - oldOffset
+  return buf
+}
+
+rnull.encode.bytes = 0
+
+rnull.decode = function (buf, offset) {
+  if (!offset) offset = 0
+  const oldOffset = offset
+  const len = buf.readUInt16BE(offset)
+
+  offset += 2
+
+  const data = buf.slice(offset, offset + len)
+  offset += len
+
+  rnull.decode.bytes = offset - oldOffset
+  return data
+}
+
+rnull.decode.bytes = 0
+
+rnull.encodingLength = function (data) {
+  if (!data) return 2
+  return (Buffer.isBuffer(data) ? data.length : Buffer.byteLength(data)) + 2
+}
+
+const rhinfo = exports.hinfo = {}
+
+rhinfo.encode = function (data, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rhinfo.encodingLength(data))
+  if (!offset) offset = 0
+
+  const oldOffset = offset
+  offset += 2
+  string.encode(data.cpu, buf, offset)
+  offset += string.encode.bytes
+  string.encode(data.os, buf, offset)
+  offset += string.encode.bytes
+  buf.writeUInt16BE(offset - oldOffset - 2, oldOffset)
+  rhinfo.encode.bytes = offset - oldOffset
+  return buf
+}
+
+rhinfo.encode.bytes = 0
+
+rhinfo.decode = function (buf, offset) {
+  if (!offset) offset = 0
+
+  const oldOffset = offset
+
+  const data = {}
+  offset += 2
+  data.cpu = string.decode(buf, offset)
+  offset += string.decode.bytes
+  data.os = string.decode(buf, offset)
+  offset += string.decode.bytes
+  rhinfo.decode.bytes = offset - oldOffset
+  return data
+}
+
+rhinfo.decode.bytes = 0
+
+rhinfo.encodingLength = function (data) {
+  return string.encodingLength(data.cpu) + string.encodingLength(data.os) + 2
+}
+
+const rptr = exports.ptr = {}
+const rcname = exports.cname = rptr
+const rdname = exports.dname = rptr
+
+rptr.encode = function (data, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rptr.encodingLength(data))
+  if (!offset) offset = 0
+
+  name.encode(data, buf, offset + 2)
+  buf.writeUInt16BE(name.encode.bytes, offset)
+  rptr.encode.bytes = name.encode.bytes + 2
+  return buf
+}
+
+rptr.encode.bytes = 0
+
+rptr.decode = function (buf, offset) {
+  if (!offset) offset = 0
+
+  const data = name.decode(buf, offset + 2)
+  rptr.decode.bytes = name.decode.bytes + 2
+  return data
+}
+
+rptr.decode.bytes = 0
+
+rptr.encodingLength = function (data) {
+  return name.encodingLength(data) + 2
+}
+
+const rsrv = exports.srv = {}
+
+rsrv.encode = function (data, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rsrv.encodingLength(data))
+  if (!offset) offset = 0
+
+  buf.writeUInt16BE(data.priority || 0, offset + 2)
+  buf.writeUInt16BE(data.weight || 0, offset + 4)
+  buf.writeUInt16BE(data.port || 0, offset + 6)
+  name.encode(data.target, buf, offset + 8)
+
+  const len = name.encode.bytes + 6
+  buf.writeUInt16BE(len, offset)
+
+  rsrv.encode.bytes = len + 2
+  return buf
+}
+
+rsrv.encode.bytes = 0
+
+rsrv.decode = function (buf, offset) {
+  if (!offset) offset = 0
+
+  const len = buf.readUInt16BE(offset)
+
+  const data = {}
+  data.priority = buf.readUInt16BE(offset + 2)
+  data.weight = buf.readUInt16BE(offset + 4)
+  data.port = buf.readUInt16BE(offset + 6)
+  data.target = name.decode(buf, offset + 8)
+
+  rsrv.decode.bytes = len + 2
+  return data
+}
+
+rsrv.decode.bytes = 0
+
+rsrv.encodingLength = function (data) {
+  return 8 + name.encodingLength(data.target)
+}
+
+const rcaa = exports.caa = {}
+
+rcaa.ISSUER_CRITICAL = 1 << 7
+
+rcaa.encode = function (data, buf, offset) {
+  const len = rcaa.encodingLength(data)
+
+  if (!buf) buf = Buffer.alloc(rcaa.encodingLength(data))
+  if (!offset) offset = 0
+
+  if (data.issuerCritical) {
+    data.flags = rcaa.ISSUER_CRITICAL
+  }
+
+  buf.writeUInt16BE(len - 2, offset)
+  offset += 2
+  buf.writeUInt8(data.flags || 0, offset)
+  offset += 1
+  string.encode(data.tag, buf, offset)
+  offset += string.encode.bytes
+  buf.write(data.value, offset)
+  offset += Buffer.byteLength(data.value)
+
+  rcaa.encode.bytes = len
+  return buf
+}
+
+rcaa.encode.bytes = 0
+
+rcaa.decode = function (buf, offset) {
+  if (!offset) offset = 0
+
+  const len = buf.readUInt16BE(offset)
+  offset += 2
+
+  const oldOffset = offset
+  const data = {}
+  data.flags = buf.readUInt8(offset)
+  offset += 1
+  data.tag = string.decode(buf, offset)
+  offset += string.decode.bytes
+  data.value = buf.toString('utf-8', offset, oldOffset + len)
+
+  data.issuerCritical = !!(data.flags & rcaa.ISSUER_CRITICAL)
+
+  rcaa.decode.bytes = len + 2
+
+  return data
+}
+
+rcaa.decode.bytes = 0
+
+rcaa.encodingLength = function (data) {
+  return string.encodingLength(data.tag) + string.encodingLength(data.value) + 2
+}
+
+const rmx = exports.mx = {}
+
+rmx.encode = function (data, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rmx.encodingLength(data))
+  if (!offset) offset = 0
+
+  const oldOffset = offset
+  offset += 2
+  buf.writeUInt16BE(data.preference || 0, offset)
+  offset += 2
+  name.encode(data.exchange, buf, offset)
+  offset += name.encode.bytes
+
+  buf.writeUInt16BE(offset - oldOffset - 2, oldOffset)
+  rmx.encode.bytes = offset - oldOffset
+  return buf
+}
+
+rmx.encode.bytes = 0
+
+rmx.decode = function (buf, offset) {
+  if (!offset) offset = 0
+
+  const oldOffset = offset
+
+  const data = {}
+  offset += 2
+  data.preference = buf.readUInt16BE(offset)
+  offset += 2
+  data.exchange = name.decode(buf, offset)
+  offset += name.decode.bytes
+
+  rmx.decode.bytes = offset - oldOffset
+  return data
+}
+
+rmx.encodingLength = function (data) {
+  return 4 + name.encodingLength(data.exchange)
+}
+
+const ra = exports.a = {}
+
+ra.encode = function (host, buf, offset) {
+  if (!buf) buf = Buffer.alloc(ra.encodingLength(host))
+  if (!offset) offset = 0
+
+  buf.writeUInt16BE(4, offset)
+  offset += 2
+  ip.v4.encode(host, buf, offset)
+  ra.encode.bytes = 6
+  return buf
+}
+
+ra.encode.bytes = 0
+
+ra.decode = function (buf, offset) {
+  if (!offset) offset = 0
+
+  offset += 2
+  const host = ip.v4.decode(buf, offset)
+  ra.decode.bytes = 6
+  return host
+}
+
+ra.decode.bytes = 0
+
+ra.encodingLength = function () {
+  return 6
+}
+
+const raaaa = exports.aaaa = {}
+
+raaaa.encode = function (host, buf, offset) {
+  if (!buf) buf = Buffer.alloc(raaaa.encodingLength(host))
+  if (!offset) offset = 0
+
+  buf.writeUInt16BE(16, offset)
+  offset += 2
+  ip.v6.encode(host, buf, offset)
+  raaaa.encode.bytes = 18
+  return buf
+}
+
+raaaa.encode.bytes = 0
+
+raaaa.decode = function (buf, offset) {
+  if (!offset) offset = 0
+
+  offset += 2
+  const host = ip.v6.decode(buf, offset)
+  raaaa.decode.bytes = 18
+  return host
+}
+
+raaaa.decode.bytes = 0
+
+raaaa.encodingLength = function () {
+  return 18
+}
+
+const roption = exports.option = {}
+
+roption.encode = function (option, buf, offset) {
+  if (!buf) buf = Buffer.alloc(roption.encodingLength(option))
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  const code = optioncodes.toCode(option.code)
+  buf.writeUInt16BE(code, offset)
+  offset += 2
+  if (option.data) {
+    buf.writeUInt16BE(option.data.length, offset)
+    offset += 2
+    option.data.copy(buf, offset)
+    offset += option.data.length
+  } else {
+    switch (code) {
+      // case 3: NSID.  No encode makes sense.
+      // case 5,6,7: Not implementable
+      case 8: // ECS
+        // note: do IP math before calling
+        const spl = option.sourcePrefixLength || 0
+        const fam = option.family || ip.familyOf(option.ip)
+        const ipBuf = ip.encode(option.ip, Buffer.alloc)
+        const ipLen = Math.ceil(spl / 8)
+        buf.writeUInt16BE(ipLen + 4, offset)
+        offset += 2
+        buf.writeUInt16BE(fam, offset)
+        offset += 2
+        buf.writeUInt8(spl, offset++)
+        buf.writeUInt8(option.scopePrefixLength || 0, offset++)
+
+        ipBuf.copy(buf, offset, 0, ipLen)
+        offset += ipLen
+        break
+      // case 9: EXPIRE (experimental)
+      // case 10: COOKIE.  No encode makes sense.
+      case 11: // KEEP-ALIVE
+        if (option.timeout) {
+          buf.writeUInt16BE(2, offset)
+          offset += 2
+          buf.writeUInt16BE(option.timeout, offset)
+          offset += 2
+        } else {
+          buf.writeUInt16BE(0, offset)
+          offset += 2
+        }
+        break
+      case 12: // PADDING
+        const len = option.length || 0
+        buf.writeUInt16BE(len, offset)
+        offset += 2
+        buf.fill(0, offset, offset + len)
+        offset += len
+        break
+      // case 13:  CHAIN.  Experimental.
+      case 14: // KEY-TAG
+        const tagsLen = option.tags.length * 2
+        buf.writeUInt16BE(tagsLen, offset)
+        offset += 2
+        for (const tag of option.tags) {
+          buf.writeUInt16BE(tag, offset)
+          offset += 2
+        }
+        break
+      default:
+        throw new Error(`Unknown roption code: ${option.code}`)
+    }
+  }
+
+  roption.encode.bytes = offset - oldOffset
+  return buf
+}
+
+roption.encode.bytes = 0
+
+roption.decode = function (buf, offset) {
+  if (!offset) offset = 0
+  const option = {}
+  option.code = buf.readUInt16BE(offset)
+  option.type = optioncodes.toString(option.code)
+  offset += 2
+  const len = buf.readUInt16BE(offset)
+  offset += 2
+  option.data = buf.slice(offset, offset + len)
+  switch (option.code) {
+    // case 3: NSID.  No decode makes sense.
+    case 8: // ECS
+      option.family = buf.readUInt16BE(offset)
+      offset += 2
+      option.sourcePrefixLength = buf.readUInt8(offset++)
+      option.scopePrefixLength = buf.readUInt8(offset++)
+      const padded = Buffer.alloc((option.family === 1) ? 4 : 16)
+      buf.copy(padded, 0, offset, offset + len - 4)
+      option.ip = ip.decode(padded)
+      break
+    // case 12: Padding.  No decode makes sense.
+    case 11: // KEEP-ALIVE
+      if (len > 0) {
+        option.timeout = buf.readUInt16BE(offset)
+        offset += 2
+      }
+      break
+    case 14:
+      option.tags = []
+      for (let i = 0; i < len; i += 2) {
+        option.tags.push(buf.readUInt16BE(offset))
+        offset += 2
+      }
+    // don't worry about default.  caller will use data if desired
+  }
+
+  roption.decode.bytes = len + 4
+  return option
+}
+
+roption.decode.bytes = 0
+
+roption.encodingLength = function (option) {
+  if (option.data) {
+    return option.data.length + 4
+  }
+  const code = optioncodes.toCode(option.code)
+  switch (code) {
+    case 8: // ECS
+      const spl = option.sourcePrefixLength || 0
+      return Math.ceil(spl / 8) + 8
+    case 11: // KEEP-ALIVE
+      return (typeof option.timeout === 'number') ? 6 : 4
+    case 12: // PADDING
+      return option.length + 4
+    case 14: // KEY-TAG
+      return 4 + (option.tags.length * 2)
+  }
+  throw new Error(`Unknown roption code: ${option.code}`)
+}
+
+const ropt = exports.opt = {}
+
+ropt.encode = function (options, buf, offset) {
+  if (!buf) buf = Buffer.alloc(ropt.encodingLength(options))
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  const rdlen = encodingLengthList(options, roption)
+  buf.writeUInt16BE(rdlen, offset)
+  offset = encodeList(options, roption, buf, offset + 2)
+
+  ropt.encode.bytes = offset - oldOffset
+  return buf
+}
+
+ropt.encode.bytes = 0
+
+ropt.decode = function (buf, offset) {
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  const options = []
+  let rdlen = buf.readUInt16BE(offset)
+  offset += 2
+  let o = 0
+  while (rdlen > 0) {
+    options[o++] = roption.decode(buf, offset)
+    offset += roption.decode.bytes
+    rdlen -= roption.decode.bytes
+  }
+  ropt.decode.bytes = offset - oldOffset
+  return options
+}
+
+ropt.decode.bytes = 0
+
+ropt.encodingLength = function (options) {
+  return 2 + encodingLengthList(options || [], roption)
+}
+
+const rdnskey = exports.dnskey = {}
+
+rdnskey.PROTOCOL_DNSSEC = 3
+rdnskey.ZONE_KEY = 0x80
+rdnskey.SECURE_ENTRYPOINT = 0x8000
+
+rdnskey.encode = function (key, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rdnskey.encodingLength(key))
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  const keydata = key.key
+  if (!Buffer.isBuffer(keydata)) {
+    throw new Error('Key must be a Buffer')
+  }
+
+  offset += 2 // Leave space for length
+  buf.writeUInt16BE(key.flags, offset)
+  offset += 2
+  buf.writeUInt8(rdnskey.PROTOCOL_DNSSEC, offset)
+  offset += 1
+  buf.writeUInt8(key.algorithm, offset)
+  offset += 1
+  keydata.copy(buf, offset, 0, keydata.length)
+  offset += keydata.length
+
+  rdnskey.encode.bytes = offset - oldOffset
+  buf.writeUInt16BE(rdnskey.encode.bytes - 2, oldOffset)
+  return buf
+}
+
+rdnskey.encode.bytes = 0
+
+rdnskey.decode = function (buf, offset) {
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  var key = {}
+  var length = buf.readUInt16BE(offset)
+  offset += 2
+  key.flags = buf.readUInt16BE(offset)
+  offset += 2
+  if (buf.readUInt8(offset) !== rdnskey.PROTOCOL_DNSSEC) {
+    throw new Error('Protocol must be 3')
+  }
+  offset += 1
+  key.algorithm = buf.readUInt8(offset)
+  offset += 1
+  key.key = buf.slice(offset, oldOffset + length + 2)
+  offset += key.key.length
+  rdnskey.decode.bytes = offset - oldOffset
+  return key
+}
+
+rdnskey.decode.bytes = 0
+
+rdnskey.encodingLength = function (key) {
+  return 6 + Buffer.byteLength(key.key)
+}
+
+const rrrsig = exports.rrsig = {}
+
+rrrsig.encode = function (sig, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rrrsig.encodingLength(sig))
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  const signature = sig.signature
+  if (!Buffer.isBuffer(signature)) {
+    throw new Error('Signature must be a Buffer')
+  }
+
+  offset += 2 // Leave space for length
+  buf.writeUInt16BE(types.toType(sig.typeCovered), offset)
+  offset += 2
+  buf.writeUInt8(sig.algorithm, offset)
+  offset += 1
+  buf.writeUInt8(sig.labels, offset)
+  offset += 1
+  buf.writeUInt32BE(sig.originalTTL, offset)
+  offset += 4
+  buf.writeUInt32BE(sig.expiration, offset)
+  offset += 4
+  buf.writeUInt32BE(sig.inception, offset)
+  offset += 4
+  buf.writeUInt16BE(sig.keyTag, offset)
+  offset += 2
+  name.encode(sig.signersName, buf, offset)
+  offset += name.encode.bytes
+  signature.copy(buf, offset, 0, signature.length)
+  offset += signature.length
+
+  rrrsig.encode.bytes = offset - oldOffset
+  buf.writeUInt16BE(rrrsig.encode.bytes - 2, oldOffset)
+  return buf
+}
+
+rrrsig.encode.bytes = 0
+
+rrrsig.decode = function (buf, offset) {
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  var sig = {}
+  var length = buf.readUInt16BE(offset)
+  offset += 2
+  sig.typeCovered = types.toString(buf.readUInt16BE(offset))
+  offset += 2
+  sig.algorithm = buf.readUInt8(offset)
+  offset += 1
+  sig.labels = buf.readUInt8(offset)
+  offset += 1
+  sig.originalTTL = buf.readUInt32BE(offset)
+  offset += 4
+  sig.expiration = buf.readUInt32BE(offset)
+  offset += 4
+  sig.inception = buf.readUInt32BE(offset)
+  offset += 4
+  sig.keyTag = buf.readUInt16BE(offset)
+  offset += 2
+  sig.signersName = name.decode(buf, offset)
+  offset += name.decode.bytes
+  sig.signature = buf.slice(offset, oldOffset + length + 2)
+  offset += sig.signature.length
+  rrrsig.decode.bytes = offset - oldOffset
+  return sig
+}
+
+rrrsig.decode.bytes = 0
+
+rrrsig.encodingLength = function (sig) {
+  return 20 +
+    name.encodingLength(sig.signersName) +
+    Buffer.byteLength(sig.signature)
+}
+
+const rrp = exports.rp = {}
+
+rrp.encode = function (data, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rrp.encodingLength(data))
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  offset += 2 // Leave space for length
+  name.encode(data.mbox || '.', buf, offset, { mail: true })
+  offset += name.encode.bytes
+  name.encode(data.txt || '.', buf, offset)
+  offset += name.encode.bytes
+  rrp.encode.bytes = offset - oldOffset
+  buf.writeUInt16BE(rrp.encode.bytes - 2, oldOffset)
+  return buf
+}
+
+rrp.encode.bytes = 0
+
+rrp.decode = function (buf, offset) {
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  const data = {}
+  offset += 2
+  data.mbox = name.decode(buf, offset, { mail: true }) || '.'
+  offset += name.decode.bytes
+  data.txt = name.decode(buf, offset) || '.'
+  offset += name.decode.bytes
+  rrp.decode.bytes = offset - oldOffset
+  return data
+}
+
+rrp.decode.bytes = 0
+
+rrp.encodingLength = function (data) {
+  return 2 + name.encodingLength(data.mbox || '.') + name.encodingLength(data.txt || '.')
+}
+
+const typebitmap = {}
+
+typebitmap.encode = function (typelist, buf, offset) {
+  if (!buf) buf = Buffer.alloc(typebitmap.encodingLength(typelist))
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  var typesByWindow = []
+  for (var i = 0; i < typelist.length; i++) {
+    var typeid = types.toType(typelist[i])
+    if (typesByWindow[typeid >> 8] === undefined) {
+      typesByWindow[typeid >> 8] = []
+    }
+    typesByWindow[typeid >> 8][(typeid >> 3) & 0x1F] |= 1 << (7 - (typeid & 0x7))
+  }
+
+  for (i = 0; i < typesByWindow.length; i++) {
+    if (typesByWindow[i] !== undefined) {
+      var windowBuf = Buffer.from(typesByWindow[i])
+      buf.writeUInt8(i, offset)
+      offset += 1
+      buf.writeUInt8(windowBuf.length, offset)
+      offset += 1
+      windowBuf.copy(buf, offset)
+      offset += windowBuf.length
+    }
+  }
+
+  typebitmap.encode.bytes = offset - oldOffset
+  return buf
+}
+
+typebitmap.encode.bytes = 0
+
+typebitmap.decode = function (buf, offset, length) {
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  var typelist = []
+  while (offset - oldOffset < length) {
+    var window = buf.readUInt8(offset)
+    offset += 1
+    var windowLength = buf.readUInt8(offset)
+    offset += 1
+    for (var i = 0; i < windowLength; i++) {
+      var b = buf.readUInt8(offset + i)
+      for (var j = 0; j < 8; j++) {
+        if (b & (1 << (7 - j))) {
+          var typeid = types.toString((window << 8) | (i << 3) | j)
+          typelist.push(typeid)
+        }
+      }
+    }
+    offset += windowLength
+  }
+
+  typebitmap.decode.bytes = offset - oldOffset
+  return typelist
+}
+
+typebitmap.decode.bytes = 0
+
+typebitmap.encodingLength = function (typelist) {
+  var extents = []
+  for (var i = 0; i < typelist.length; i++) {
+    var typeid = types.toType(typelist[i])
+    extents[typeid >> 8] = Math.max(extents[typeid >> 8] || 0, typeid & 0xFF)
+  }
+
+  var len = 0
+  for (i = 0; i < extents.length; i++) {
+    if (extents[i] !== undefined) {
+      len += 2 + Math.ceil((extents[i] + 1) / 8)
+    }
+  }
+
+  return len
+}
+
+const rnsec = exports.nsec = {}
+
+rnsec.encode = function (record, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rnsec.encodingLength(record))
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  offset += 2 // Leave space for length
+  name.encode(record.nextDomain, buf, offset)
+  offset += name.encode.bytes
+  typebitmap.encode(record.rrtypes, buf, offset)
+  offset += typebitmap.encode.bytes
+
+  rnsec.encode.bytes = offset - oldOffset
+  buf.writeUInt16BE(rnsec.encode.bytes - 2, oldOffset)
+  return buf
+}
+
+rnsec.encode.bytes = 0
+
+rnsec.decode = function (buf, offset) {
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  var record = {}
+  var length = buf.readUInt16BE(offset)
+  offset += 2
+  record.nextDomain = name.decode(buf, offset)
+  offset += name.decode.bytes
+  record.rrtypes = typebitmap.decode(buf, offset, length - (offset - oldOffset))
+  offset += typebitmap.decode.bytes
+
+  rnsec.decode.bytes = offset - oldOffset
+  return record
+}
+
+rnsec.decode.bytes = 0
+
+rnsec.encodingLength = function (record) {
+  return 2 +
+    name.encodingLength(record.nextDomain) +
+    typebitmap.encodingLength(record.rrtypes)
+}
+
+const rnsec3 = exports.nsec3 = {}
+
+rnsec3.encode = function (record, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rnsec3.encodingLength(record))
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  const salt = record.salt
+  if (!Buffer.isBuffer(salt)) {
+    throw new Error('salt must be a Buffer')
+  }
+
+  const nextDomain = record.nextDomain
+  if (!Buffer.isBuffer(nextDomain)) {
+    throw new Error('nextDomain must be a Buffer')
+  }
+
+  offset += 2 // Leave space for length
+  buf.writeUInt8(record.algorithm, offset)
+  offset += 1
+  buf.writeUInt8(record.flags, offset)
+  offset += 1
+  buf.writeUInt16BE(record.iterations, offset)
+  offset += 2
+  buf.writeUInt8(salt.length, offset)
+  offset += 1
+  salt.copy(buf, offset, 0, salt.length)
+  offset += salt.length
+  buf.writeUInt8(nextDomain.length, offset)
+  offset += 1
+  nextDomain.copy(buf, offset, 0, nextDomain.length)
+  offset += nextDomain.length
+  typebitmap.encode(record.rrtypes, buf, offset)
+  offset += typebitmap.encode.bytes
+
+  rnsec3.encode.bytes = offset - oldOffset
+  buf.writeUInt16BE(rnsec3.encode.bytes - 2, oldOffset)
+  return buf
+}
+
+rnsec3.encode.bytes = 0
+
+rnsec3.decode = function (buf, offset) {
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  var record = {}
+  var length = buf.readUInt16BE(offset)
+  offset += 2
+  record.algorithm = buf.readUInt8(offset)
+  offset += 1
+  record.flags = buf.readUInt8(offset)
+  offset += 1
+  record.iterations = buf.readUInt16BE(offset)
+  offset += 2
+  const saltLength = buf.readUInt8(offset)
+  offset += 1
+  record.salt = buf.slice(offset, offset + saltLength)
+  offset += saltLength
+  const hashLength = buf.readUInt8(offset)
+  offset += 1
+  record.nextDomain = buf.slice(offset, offset + hashLength)
+  offset += hashLength
+  record.rrtypes = typebitmap.decode(buf, offset, length - (offset - oldOffset))
+  offset += typebitmap.decode.bytes
+
+  rnsec3.decode.bytes = offset - oldOffset
+  return record
+}
+
+rnsec3.decode.bytes = 0
+
+rnsec3.encodingLength = function (record) {
+  return 8 +
+    record.salt.length +
+    record.nextDomain.length +
+    typebitmap.encodingLength(record.rrtypes)
+}
+
+const rds = exports.ds = {}
+
+rds.encode = function (digest, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rds.encodingLength(digest))
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  const digestdata = digest.digest
+  if (!Buffer.isBuffer(digestdata)) {
+    throw new Error('Digest must be a Buffer')
+  }
+
+  offset += 2 // Leave space for length
+  buf.writeUInt16BE(digest.keyTag, offset)
+  offset += 2
+  buf.writeUInt8(digest.algorithm, offset)
+  offset += 1
+  buf.writeUInt8(digest.digestType, offset)
+  offset += 1
+  digestdata.copy(buf, offset, 0, digestdata.length)
+  offset += digestdata.length
+
+  rds.encode.bytes = offset - oldOffset
+  buf.writeUInt16BE(rds.encode.bytes - 2, oldOffset)
+  return buf
+}
+
+rds.encode.bytes = 0
+
+rds.decode = function (buf, offset) {
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  var digest = {}
+  var length = buf.readUInt16BE(offset)
+  offset += 2
+  digest.keyTag = buf.readUInt16BE(offset)
+  offset += 2
+  digest.algorithm = buf.readUInt8(offset)
+  offset += 1
+  digest.digestType = buf.readUInt8(offset)
+  offset += 1
+  digest.digest = buf.slice(offset, oldOffset + length + 2)
+  offset += digest.digest.length
+  rds.decode.bytes = offset - oldOffset
+  return digest
+}
+
+rds.decode.bytes = 0
+
+rds.encodingLength = function (digest) {
+  return 6 + Buffer.byteLength(digest.digest)
+}
+
+const rsshfp = exports.sshfp = {}
+
+rsshfp.getFingerprintLengthForHashType = function getFingerprintLengthForHashType (hashType) {
+  switch (hashType) {
+    case 1: return 20
+    case 2: return 32
+  }
+}
+
+rsshfp.encode = function encode (record, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rsshfp.encodingLength(record))
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  offset += 2 // The function call starts with the offset pointer at the RDLENGTH field, not the RDATA one
+  buf[offset] = record.algorithm
+  offset += 1
+  buf[offset] = record.hash
+  offset += 1
+
+  const fingerprintBuf = Buffer.from(record.fingerprint.toUpperCase(), 'hex')
+  if (fingerprintBuf.length !== rsshfp.getFingerprintLengthForHashType(record.hash)) {
+    throw new Error('Invalid fingerprint length')
+  }
+  fingerprintBuf.copy(buf, offset)
+  offset += fingerprintBuf.byteLength
+
+  rsshfp.encode.bytes = offset - oldOffset
+  buf.writeUInt16BE(rsshfp.encode.bytes - 2, oldOffset)
+
+  return buf
+}
+
+rsshfp.encode.bytes = 0
+
+rsshfp.decode = function decode (buf, offset) {
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  const record = {}
+  offset += 2 // Account for the RDLENGTH field
+  record.algorithm = buf[offset]
+  offset += 1
+  record.hash = buf[offset]
+  offset += 1
+
+  const fingerprintLength = rsshfp.getFingerprintLengthForHashType(record.hash)
+  record.fingerprint = buf.slice(offset, offset + fingerprintLength).toString('hex').toUpperCase()
+  offset += fingerprintLength
+  rsshfp.decode.bytes = offset - oldOffset
+  return record
+}
+
+rsshfp.decode.bytes = 0
+
+rsshfp.encodingLength = function (record) {
+  return 4 + Buffer.from(record.fingerprint, 'hex').byteLength
+}
+
+const rnaptr = exports.naptr = {}
+
+rnaptr.encode = function (data, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rnaptr.encodingLength(data))
+  if (!offset) offset = 0
+  const oldOffset = offset
+  offset += 2
+  buf.writeUInt16BE(data.order || 0, offset)
+  offset += 2
+  buf.writeUInt16BE(data.preference || 0, offset)
+  offset += 2
+  string.encode(data.flags, buf, offset)
+  offset += string.encode.bytes
+  string.encode(data.services, buf, offset)
+  offset += string.encode.bytes
+  string.encode(data.regexp, buf, offset)
+  offset += string.encode.bytes
+  name.encode(data.replacement, buf, offset)
+  offset += name.encode.bytes
+  rnaptr.encode.bytes = offset - oldOffset
+  buf.writeUInt16BE(rnaptr.encode.bytes - 2, oldOffset)
+  return buf
+}
+
+rnaptr.encode.bytes = 0
+
+rnaptr.decode = function (buf, offset) {
+  if (!offset) offset = 0
+  const oldOffset = offset
+  const data = {}
+  offset += 2
+  data.order = buf.readUInt16BE(offset)
+  offset += 2
+  data.preference = buf.readUInt16BE(offset)
+  offset += 2
+  data.flags = string.decode(buf, offset)
+  offset += string.decode.bytes
+  data.services = string.decode(buf, offset)
+  offset += string.decode.bytes
+  data.regexp = string.decode(buf, offset)
+  offset += string.decode.bytes
+  data.replacement = name.decode(buf, offset)
+  offset += name.decode.bytes
+  rnaptr.decode.bytes = offset - oldOffset
+  return data
+}
+
+rnaptr.decode.bytes = 0
+
+rnaptr.encodingLength = function (data) {
+  return string.encodingLength(data.flags) +
+    string.encodingLength(data.services) +
+    string.encodingLength(data.regexp) +
+    name.encodingLength(data.replacement) + 6
+}
+
+const rtlsa = exports.tlsa = {}
+
+rtlsa.encode = function (cert, buf, offset) {
+  if (!buf) buf = Buffer.alloc(rtlsa.encodingLength(cert))
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  const certdata = cert.certificate
+  if (!Buffer.isBuffer(certdata)) {
+    throw new Error('Certificate must be a Buffer')
+  }
+
+  offset += 2 // Leave space for length
+  buf.writeUInt8(cert.usage, offset)
+  offset += 1
+  buf.writeUInt8(cert.selector, offset)
+  offset += 1
+  buf.writeUInt8(cert.matchingType, offset)
+  offset += 1
+  certdata.copy(buf, offset, 0, certdata.length)
+  offset += certdata.length
+
+  rtlsa.encode.bytes = offset - oldOffset
+  buf.writeUInt16BE(rtlsa.encode.bytes - 2, oldOffset)
+  return buf
+}
+
+rtlsa.encode.bytes = 0
+
+rtlsa.decode = function (buf, offset) {
+  if (!offset) offset = 0
+  const oldOffset = offset
+
+  const cert = {}
+  const length = buf.readUInt16BE(offset)
+  offset += 2
+  cert.usage = buf.readUInt8(offset)
+  offset += 1
+  cert.selector = buf.readUInt8(offset)
+  offset += 1
+  cert.matchingType = buf.readUInt8(offset)
+  offset += 1
+  cert.certificate = buf.slice(offset, oldOffset + length + 2)
+  offset += cert.certificate.length
+  rtlsa.decode.bytes = offset - oldOffset
+  return cert
+}
+
+rtlsa.decode.bytes = 0
+
+rtlsa.encodingLength = function (cert) {
+  return 5 + Buffer.byteLength(cert.certificate)
+}
+
+const renc = exports.record = function (type) {
+  switch (type.toUpperCase()) {
+    case 'A': return ra
+    case 'PTR': return rptr
+    case 'CNAME': return rcname
+    case 'DNAME': return rdname
+    case 'TXT': return rtxt
+    case 'NULL': return rnull
+    case 'AAAA': return raaaa
+    case 'SRV': return rsrv
+    case 'HINFO': return rhinfo
+    case 'CAA': return rcaa
+    case 'NS': return rns
+    case 'SOA': return rsoa
+    case 'MX': return rmx
+    case 'OPT': return ropt
+    case 'DNSKEY': return rdnskey
+    case 'RRSIG': return rrrsig
+    case 'RP': return rrp
+    case 'NSEC': return rnsec
+    case 'NSEC3': return rnsec3
+    case 'SSHFP': return rsshfp
+    case 'DS': return rds
+    case 'NAPTR': return rnaptr
+    case 'TLSA': return rtlsa
+  }
+  return runknown
+}
+
+const answer = exports.answer = {}
+
+answer.encode = function (a, buf, offset) {
+  if (!buf) buf = Buffer.alloc(answer.encodingLength(a))
+  if (!offset) offset = 0
+
+  const oldOffset = offset
+
+  name.encode(a.name, buf, offset)
+  offset += name.encode.bytes
+
+  buf.writeUInt16BE(types.toType(a.type), offset)
+
+  if (a.type.toUpperCase() === 'OPT') {
+    if (a.name !== '.') {
+      throw new Error('OPT name must be root.')
+    }
+    buf.writeUInt16BE(a.udpPayloadSize || 4096, offset + 2)
+    buf.writeUInt8(a.extendedRcode || 0, offset + 4)
+    buf.writeUInt8(a.ednsVersion || 0, offset + 5)
+    buf.writeUInt16BE(a.flags || 0, offset + 6)
+
+    offset += 8
+    ropt.encode(a.options || [], buf, offset)
+    offset += ropt.encode.bytes
+  } else {
+    let klass = classes.toClass(a.class === undefined ? 'IN' : a.class)
+    if (a.flush) klass |= FLUSH_MASK // the 1st bit of the class is the flush bit
+    buf.writeUInt16BE(klass, offset + 2)
+    buf.writeUInt32BE(a.ttl || 0, offset + 4)
+
+    offset += 8
+    const enc = renc(a.type)
+    enc.encode(a.data, buf, offset)
+    offset += enc.encode.bytes
+  }
+
+  answer.encode.bytes = offset - oldOffset
+  return buf
+}
+
+answer.encode.bytes = 0
+
+answer.decode = function (buf, offset) {
+  if (!offset) offset = 0
+
+  const a = {}
+  const oldOffset = offset
+
+  a.name = name.decode(buf, offset)
+  offset += name.decode.bytes
+  a.type = types.toString(buf.readUInt16BE(offset))
+  if (a.type === 'OPT') {
+    a.udpPayloadSize = buf.readUInt16BE(offset + 2)
+    a.extendedRcode = buf.readUInt8(offset + 4)
+    a.ednsVersion = buf.readUInt8(offset + 5)
+    a.flags = buf.readUInt16BE(offset + 6)
+    a.flag_do = ((a.flags >> 15) & 0x1) === 1
+    a.options = ropt.decode(buf, offset + 8)
+    offset += 8 + ropt.decode.bytes
+  } else {
+    const klass = buf.readUInt16BE(offset + 2)
+    a.ttl = buf.readUInt32BE(offset + 4)
+
+    a.class = classes.toString(klass & NOT_FLUSH_MASK)
+    a.flush = !!(klass & FLUSH_MASK)
+
+    const enc = renc(a.type)
+    a.data = enc.decode(buf, offset + 8)
+    offset += 8 + enc.decode.bytes
+  }
+
+  answer.decode.bytes = offset - oldOffset
+  return a
+}
+
+answer.decode.bytes = 0
+
+answer.encodingLength = function (a) {
+  const data = (a.data !== null && a.data !== undefined) ? a.data : a.options
+  return name.encodingLength(a.name) + 8 + renc(a.type).encodingLength(data)
+}
+
+const question = exports.question = {}
+
+question.encode = function (q, buf, offset) {
+  if (!buf) buf = Buffer.alloc(question.encodingLength(q))
+  if (!offset) offset = 0
+
+  const oldOffset = offset
+
+  name.encode(q.name, buf, offset)
+  offset += name.encode.bytes
+
+  buf.writeUInt16BE(types.toType(q.type), offset)
+  offset += 2
+
+  buf.writeUInt16BE(classes.toClass(q.class === undefined ? 'IN' : q.class), offset)
+  offset += 2
+
+  question.encode.bytes = offset - oldOffset
+  return q
+}
+
+question.encode.bytes = 0
+
+question.decode = function (buf, offset) {
+  if (!offset) offset = 0
+
+  const oldOffset = offset
+  const q = {}
+
+  q.name = name.decode(buf, offset)
+  offset += name.decode.bytes
+
+  q.type = types.toString(buf.readUInt16BE(offset))
+  offset += 2
+
+  q.class = classes.toString(buf.readUInt16BE(offset))
+  offset += 2
+
+  const qu = !!(q.class & QU_MASK)
+  if (qu) q.class &= NOT_QU_MASK
+
+  question.decode.bytes = offset - oldOffset
+  return q
+}
+
+question.decode.bytes = 0
+
+question.encodingLength = function (q) {
+  return name.encodingLength(q.name) + 4
+}
+
+exports.AUTHORITATIVE_ANSWER = 1 << 10
+exports.TRUNCATED_RESPONSE = 1 << 9
+exports.RECURSION_DESIRED = 1 << 8
+exports.RECURSION_AVAILABLE = 1 << 7
+exports.AUTHENTIC_DATA = 1 << 5
+exports.CHECKING_DISABLED = 1 << 4
+exports.DNSSEC_OK = 1 << 15
+
+exports.encode = function (result, buf, offset) {
+  const allocing = !buf
+
+  if (allocing) buf = Buffer.alloc(exports.encodingLength(result))
+  if (!offset) offset = 0
+
+  const oldOffset = offset
+
+  if (!result.questions) result.questions = []
+  if (!result.answers) result.answers = []
+  if (!result.authorities) result.authorities = []
+  if (!result.additionals) result.additionals = []
+
+  header.encode(result, buf, offset)
+  offset += header.encode.bytes
+
+  offset = encodeList(result.questions, question, buf, offset)
+  offset = encodeList(result.answers, answer, buf, offset)
+  offset = encodeList(result.authorities, answer, buf, offset)
+  offset = encodeList(result.additionals, answer, buf, offset)
+
+  exports.encode.bytes = offset - oldOffset
+
+  // just a quick sanity check
+  if (allocing && exports.encode.bytes !== buf.length) {
+    return buf.slice(0, exports.encode.bytes)
+  }
+
+  return buf
+}
+
+exports.encode.bytes = 0
+
+exports.decode = function (buf, offset) {
+  if (!offset) offset = 0
+
+  const oldOffset = offset
+  const result = header.decode(buf, offset)
+  offset += header.decode.bytes
+
+  offset = decodeList(result.questions, question, buf, offset)
+  offset = decodeList(result.answers, answer, buf, offset)
+  offset = decodeList(result.authorities, answer, buf, offset)
+  offset = decodeList(result.additionals, answer, buf, offset)
+
+  exports.decode.bytes = offset - oldOffset
+
+  return result
+}
+
+exports.decode.bytes = 0
+
+exports.encodingLength = function (result) {
+  return header.encodingLength(result) +
+    encodingLengthList(result.questions || [], question) +
+    encodingLengthList(result.answers || [], answer) +
+    encodingLengthList(result.authorities || [], answer) +
+    encodingLengthList(result.additionals || [], answer)
+}
+
+exports.streamEncode = function (result) {
+  const buf = exports.encode(result)
+  const sbuf = Buffer.alloc(2)
+  sbuf.writeUInt16BE(buf.byteLength)
+  const combine = Buffer.concat([sbuf, buf])
+  exports.streamEncode.bytes = combine.byteLength
+  return combine
+}
+
+exports.streamEncode.bytes = 0
+
+exports.streamDecode = function (sbuf) {
+  const len = sbuf.readUInt16BE(0)
+  if (sbuf.byteLength < len + 2) {
+    // not enough data
+    return null
+  }
+  const result = exports.decode(sbuf.slice(2))
+  exports.streamDecode.bytes = exports.decode.bytes
+  return result
+}
+
+exports.streamDecode.bytes = 0
+
+function encodingLengthList (list, enc) {
+  let len = 0
+  for (let i = 0; i < list.length; i++) len += enc.encodingLength(list[i])
+  return len
+}
+
+function encodeList (list, enc, buf, offset) {
+  for (let i = 0; i < list.length; i++) {
+    enc.encode(list[i], buf, offset)
+    offset += enc.encode.bytes
+  }
+  return offset
+}
+
+function decodeList (list, enc, buf, offset) {
+  for (let i = 0; i < list.length; i++) {
+    list[i] = enc.decode(buf, offset)
+    offset += enc.decode.bytes
+  }
+  return offset
+}