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