An abstract-encoding compliant module for encoding / decoding DNS packets. Lifted out of multicast-dns as a separate module.
npm install dns-packet
var packet = require('dns-packet')
var dgram = require('dgram')
var socket = dgram.createSocket('udp4')
var buf = packet.encode({
type: 'query',
id: 1,
questions: [{
type: 'A',
name: 'google.com'
}]
})
socket.on('message', function (message) {
console.log(packet.decode(message)) // prints out a response from google dns
})
socket.send(buf, 0, buf.length, 53, '8.8.8.8')
Encodes a DNS packet into a buffer.
Decode a DNS packet from a buffer
Returns how many bytes are needed to encode the DNS packet
Packets look like this
{
type: 'query|response',
id: optionalIdNumber,
questions: [...],
answers: [...],
additionals: [...],
authorities: [...]
}
A question looks like this
{
type: 'A', // or SRV, AAAA, etc
name: 'google.com' // which record are you looking for
}
And an answers, additional, or authority looks like this
{
type: 'A', // or SRV, AAAA, etc
name: 'google.com', // which name is this record for
ttl: optionalTimeToLiveInSeconds,
(record specific data, see below)
}
Currently the different available records are
{
data: 'IPv4 address' // fx 127.0.0.1
}
{
data: 'IPv6 address' // fx fe80::1
}
{
data: Buffer('some text')
}
{
data: Buffer('any binary data')
}
{
data: {
port: servicePort,
target: serviceHostName,
priority: optionalServicePriority,
weight: optionalServiceWeight
}
}
{
data: {
cpu: 'cpu info',
os: 'os info'
}
}
{
data: 'points.to.another.record'
}
{
data: 'cname.to.another.record'
}
{
data: 'dname.to.another.record'
}
If you need another one, open an issue and we'll try to add it.
MIT