mirror of
https://github.com/JasonYANG170/IOTConnect-Web.git
synced 2024-10-19 14:01:59 +00:00
810 lines
24 KiB
JavaScript
810 lines
24 KiB
JavaScript
const bl = require('bl')
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const { EventEmitter } = require('events')
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const Packet = require('./packet')
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const constants = require('./constants')
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const debug = require('debug')('mqtt-packet:parser')
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class Parser extends EventEmitter {
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constructor () {
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super()
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this.parser = this.constructor.parser
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}
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static parser (opt) {
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if (!(this instanceof Parser)) return (new Parser()).parser(opt)
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this.settings = opt || {}
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this._states = [
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'_parseHeader',
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'_parseLength',
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'_parsePayload',
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'_newPacket'
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]
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this._resetState()
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return this
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}
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_resetState () {
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debug('_resetState: resetting packet, error, _list, and _stateCounter')
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this.packet = new Packet()
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this.error = null
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this._list = bl()
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this._stateCounter = 0
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}
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parse (buf) {
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if (this.error) this._resetState()
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this._list.append(buf)
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debug('parse: current state: %s', this._states[this._stateCounter])
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while ((this.packet.length !== -1 || this._list.length > 0) &&
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this[this._states[this._stateCounter]]() &&
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!this.error) {
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this._stateCounter++
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debug('parse: state complete. _stateCounter is now: %d', this._stateCounter)
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debug('parse: packet.length: %d, buffer list length: %d', this.packet.length, this._list.length)
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if (this._stateCounter >= this._states.length) this._stateCounter = 0
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}
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debug('parse: exited while loop. packet: %d, buffer list length: %d', this.packet.length, this._list.length)
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return this._list.length
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}
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_parseHeader () {
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// There is at least one byte in the buffer
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const zero = this._list.readUInt8(0)
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const cmdIndex = zero >> constants.CMD_SHIFT
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this.packet.cmd = constants.types[cmdIndex]
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const headerFlags = zero & 0xf
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const requiredHeaderFlags = constants.requiredHeaderFlags[cmdIndex]
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if (requiredHeaderFlags != null && headerFlags !== requiredHeaderFlags) {
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// Where a flag bit is marked as “Reserved” in Table 2.2 - Flag Bits, it is reserved for future use and MUST be set to the value listed in that table [MQTT-2.2.2-1]. If invalid flags are received, the receiver MUST close the Network Connection [MQTT-2.2.2-2]
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return this._emitError(new Error(constants.requiredHeaderFlagsErrors[cmdIndex]))
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}
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this.packet.retain = (zero & constants.RETAIN_MASK) !== 0
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this.packet.qos = (zero >> constants.QOS_SHIFT) & constants.QOS_MASK
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if (this.packet.qos > 2) {
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return this._emitError(new Error('Packet must not have both QoS bits set to 1'))
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}
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this.packet.dup = (zero & constants.DUP_MASK) !== 0
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debug('_parseHeader: packet: %o', this.packet)
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this._list.consume(1)
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return true
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}
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_parseLength () {
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// There is at least one byte in the list
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const result = this._parseVarByteNum(true)
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if (result) {
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this.packet.length = result.value
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this._list.consume(result.bytes)
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}
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debug('_parseLength %d', result.value)
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return !!result
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}
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_parsePayload () {
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debug('_parsePayload: payload %O', this._list)
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let result = false
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// Do we have a payload? Do we have enough data to complete the payload?
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// PINGs have no payload
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if (this.packet.length === 0 || this._list.length >= this.packet.length) {
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this._pos = 0
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switch (this.packet.cmd) {
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case 'connect':
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this._parseConnect()
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break
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case 'connack':
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this._parseConnack()
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break
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case 'publish':
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this._parsePublish()
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break
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case 'puback':
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case 'pubrec':
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case 'pubrel':
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case 'pubcomp':
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this._parseConfirmation()
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break
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case 'subscribe':
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this._parseSubscribe()
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break
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case 'suback':
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this._parseSuback()
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break
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case 'unsubscribe':
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this._parseUnsubscribe()
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break
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case 'unsuback':
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this._parseUnsuback()
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break
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case 'pingreq':
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case 'pingresp':
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// These are empty, nothing to do
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break
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case 'disconnect':
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this._parseDisconnect()
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break
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case 'auth':
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this._parseAuth()
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break
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default:
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this._emitError(new Error('Not supported'))
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}
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result = true
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}
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debug('_parsePayload complete result: %s', result)
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return result
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}
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_parseConnect () {
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debug('_parseConnect')
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let topic // Will topic
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let payload // Will payload
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let password // Password
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let username // Username
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const flags = {}
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const packet = this.packet
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// Parse protocolId
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const protocolId = this._parseString()
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if (protocolId === null) return this._emitError(new Error('Cannot parse protocolId'))
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if (protocolId !== 'MQTT' && protocolId !== 'MQIsdp') {
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return this._emitError(new Error('Invalid protocolId'))
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}
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packet.protocolId = protocolId
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// Parse constants version number
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if (this._pos >= this._list.length) return this._emitError(new Error('Packet too short'))
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packet.protocolVersion = this._list.readUInt8(this._pos)
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if (packet.protocolVersion >= 128) {
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packet.bridgeMode = true
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packet.protocolVersion = packet.protocolVersion - 128
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}
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if (packet.protocolVersion !== 3 && packet.protocolVersion !== 4 && packet.protocolVersion !== 5) {
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return this._emitError(new Error('Invalid protocol version'))
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}
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this._pos++
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if (this._pos >= this._list.length) {
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return this._emitError(new Error('Packet too short'))
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}
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if (this._list.readUInt8(this._pos) & 0x1) {
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// The Server MUST validate that the reserved flag in the CONNECT Control Packet is set to zero and disconnect the Client if it is not zero [MQTT-3.1.2-3]
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return this._emitError(new Error('Connect flag bit 0 must be 0, but got 1'))
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}
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// Parse connect flags
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flags.username = (this._list.readUInt8(this._pos) & constants.USERNAME_MASK)
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flags.password = (this._list.readUInt8(this._pos) & constants.PASSWORD_MASK)
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flags.will = (this._list.readUInt8(this._pos) & constants.WILL_FLAG_MASK)
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const willRetain = !!(this._list.readUInt8(this._pos) & constants.WILL_RETAIN_MASK)
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const willQos = (this._list.readUInt8(this._pos) &
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constants.WILL_QOS_MASK) >> constants.WILL_QOS_SHIFT
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if (flags.will) {
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packet.will = {}
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packet.will.retain = willRetain
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packet.will.qos = willQos
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} else {
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if (willRetain) {
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return this._emitError(new Error('Will Retain Flag must be set to zero when Will Flag is set to 0'))
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}
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if (willQos) {
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return this._emitError(new Error('Will QoS must be set to zero when Will Flag is set to 0'))
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}
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}
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packet.clean = (this._list.readUInt8(this._pos) & constants.CLEAN_SESSION_MASK) !== 0
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this._pos++
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// Parse keepalive
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packet.keepalive = this._parseNum()
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if (packet.keepalive === -1) return this._emitError(new Error('Packet too short'))
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// parse properties
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if (packet.protocolVersion === 5) {
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const properties = this._parseProperties()
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if (Object.getOwnPropertyNames(properties).length) {
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packet.properties = properties
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}
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}
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// Parse clientId
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const clientId = this._parseString()
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if (clientId === null) return this._emitError(new Error('Packet too short'))
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packet.clientId = clientId
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debug('_parseConnect: packet.clientId: %s', packet.clientId)
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if (flags.will) {
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if (packet.protocolVersion === 5) {
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const willProperties = this._parseProperties()
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if (Object.getOwnPropertyNames(willProperties).length) {
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packet.will.properties = willProperties
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}
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}
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// Parse will topic
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topic = this._parseString()
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if (topic === null) return this._emitError(new Error('Cannot parse will topic'))
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packet.will.topic = topic
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debug('_parseConnect: packet.will.topic: %s', packet.will.topic)
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// Parse will payload
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payload = this._parseBuffer()
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if (payload === null) return this._emitError(new Error('Cannot parse will payload'))
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packet.will.payload = payload
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debug('_parseConnect: packet.will.paylaod: %s', packet.will.payload)
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}
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// Parse username
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if (flags.username) {
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username = this._parseString()
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if (username === null) return this._emitError(new Error('Cannot parse username'))
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packet.username = username
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debug('_parseConnect: packet.username: %s', packet.username)
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}
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// Parse password
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if (flags.password) {
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password = this._parseBuffer()
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if (password === null) return this._emitError(new Error('Cannot parse password'))
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packet.password = password
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}
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// need for right parse auth packet and self set up
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this.settings = packet
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debug('_parseConnect: complete')
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return packet
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}
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_parseConnack () {
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debug('_parseConnack')
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const packet = this.packet
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if (this._list.length < 1) return null
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const flags = this._list.readUInt8(this._pos++)
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if (flags > 1) {
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return this._emitError(new Error('Invalid connack flags, bits 7-1 must be set to 0'))
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}
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packet.sessionPresent = !!(flags & constants.SESSIONPRESENT_MASK)
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if (this.settings.protocolVersion === 5) {
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if (this._list.length >= 2) {
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packet.reasonCode = this._list.readUInt8(this._pos++)
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} else {
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packet.reasonCode = 0
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}
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} else {
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if (this._list.length < 2) return null
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packet.returnCode = this._list.readUInt8(this._pos++)
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}
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if (packet.returnCode === -1 || packet.reasonCode === -1) return this._emitError(new Error('Cannot parse return code'))
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// mqtt 5 properties
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if (this.settings.protocolVersion === 5) {
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const properties = this._parseProperties()
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if (Object.getOwnPropertyNames(properties).length) {
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packet.properties = properties
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}
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}
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debug('_parseConnack: complete')
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}
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_parsePublish () {
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debug('_parsePublish')
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const packet = this.packet
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packet.topic = this._parseString()
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if (packet.topic === null) return this._emitError(new Error('Cannot parse topic'))
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// Parse messageId
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if (packet.qos > 0) if (!this._parseMessageId()) { return }
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// Properties mqtt 5
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if (this.settings.protocolVersion === 5) {
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const properties = this._parseProperties()
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if (Object.getOwnPropertyNames(properties).length) {
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packet.properties = properties
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}
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}
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packet.payload = this._list.slice(this._pos, packet.length)
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debug('_parsePublish: payload from buffer list: %o', packet.payload)
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}
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_parseSubscribe () {
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debug('_parseSubscribe')
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const packet = this.packet
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let topic
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let options
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let qos
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let rh
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let rap
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let nl
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let subscription
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packet.subscriptions = []
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if (!this._parseMessageId()) { return }
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// Properties mqtt 5
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if (this.settings.protocolVersion === 5) {
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const properties = this._parseProperties()
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if (Object.getOwnPropertyNames(properties).length) {
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packet.properties = properties
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}
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}
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if (packet.length <= 0) { return this._emitError(new Error('Malformed subscribe, no payload specified')) }
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while (this._pos < packet.length) {
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// Parse topic
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topic = this._parseString()
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if (topic === null) return this._emitError(new Error('Cannot parse topic'))
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if (this._pos >= packet.length) return this._emitError(new Error('Malformed Subscribe Payload'))
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options = this._parseByte()
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if (this.settings.protocolVersion === 5) {
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if (options & 0xc0) {
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return this._emitError(new Error('Invalid subscribe topic flag bits, bits 7-6 must be 0'))
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}
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} else {
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if (options & 0xfc) {
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return this._emitError(new Error('Invalid subscribe topic flag bits, bits 7-2 must be 0'))
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}
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}
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qos = options & constants.SUBSCRIBE_OPTIONS_QOS_MASK
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if (qos > 2) {
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return this._emitError(new Error('Invalid subscribe QoS, must be <= 2'))
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}
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nl = ((options >> constants.SUBSCRIBE_OPTIONS_NL_SHIFT) & constants.SUBSCRIBE_OPTIONS_NL_MASK) !== 0
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rap = ((options >> constants.SUBSCRIBE_OPTIONS_RAP_SHIFT) & constants.SUBSCRIBE_OPTIONS_RAP_MASK) !== 0
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rh = (options >> constants.SUBSCRIBE_OPTIONS_RH_SHIFT) & constants.SUBSCRIBE_OPTIONS_RH_MASK
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if (rh > 2) {
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return this._emitError(new Error('Invalid retain handling, must be <= 2'))
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}
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subscription = { topic, qos }
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// mqtt 5 options
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if (this.settings.protocolVersion === 5) {
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subscription.nl = nl
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subscription.rap = rap
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subscription.rh = rh
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} else if (this.settings.bridgeMode) {
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subscription.rh = 0
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subscription.rap = true
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subscription.nl = true
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}
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// Push pair to subscriptions
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debug('_parseSubscribe: push subscription `%s` to subscription', subscription)
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packet.subscriptions.push(subscription)
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}
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}
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_parseSuback () {
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debug('_parseSuback')
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const packet = this.packet
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this.packet.granted = []
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if (!this._parseMessageId()) { return }
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// Properties mqtt 5
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if (this.settings.protocolVersion === 5) {
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const properties = this._parseProperties()
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if (Object.getOwnPropertyNames(properties).length) {
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packet.properties = properties
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}
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}
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if (packet.length <= 0) { return this._emitError(new Error('Malformed suback, no payload specified')) }
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// Parse granted QoSes
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while (this._pos < this.packet.length) {
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const code = this._list.readUInt8(this._pos++)
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if (this.settings.protocolVersion === 5) {
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if (!constants.MQTT5_SUBACK_CODES[code]) {
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return this._emitError(new Error('Invalid suback code'))
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}
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} else {
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if (code > 2 && code !== 0x80) {
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return this._emitError(new Error('Invalid suback QoS, must be 0, 1, 2 or 128'))
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}
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}
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this.packet.granted.push(code)
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}
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}
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_parseUnsubscribe () {
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debug('_parseUnsubscribe')
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const packet = this.packet
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packet.unsubscriptions = []
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// Parse messageId
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if (!this._parseMessageId()) { return }
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// Properties mqtt 5
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if (this.settings.protocolVersion === 5) {
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const properties = this._parseProperties()
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if (Object.getOwnPropertyNames(properties).length) {
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packet.properties = properties
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}
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}
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if (packet.length <= 0) { return this._emitError(new Error('Malformed unsubscribe, no payload specified')) }
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while (this._pos < packet.length) {
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// Parse topic
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const topic = this._parseString()
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if (topic === null) return this._emitError(new Error('Cannot parse topic'))
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// Push topic to unsubscriptions
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debug('_parseUnsubscribe: push topic `%s` to unsubscriptions', topic)
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packet.unsubscriptions.push(topic)
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}
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}
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_parseUnsuback () {
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debug('_parseUnsuback')
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const packet = this.packet
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if (!this._parseMessageId()) return this._emitError(new Error('Cannot parse messageId'))
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if ((this.settings.protocolVersion === 3 ||
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this.settings.protocolVersion === 4) && packet.length !== 2) {
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return this._emitError(new Error('Malformed unsuback, payload length must be 2'))
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}
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if (packet.length <= 0) { return this._emitError(new Error('Malformed unsuback, no payload specified')) }
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// Properties mqtt 5
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if (this.settings.protocolVersion === 5) {
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const properties = this._parseProperties()
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if (Object.getOwnPropertyNames(properties).length) {
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packet.properties = properties
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}
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// Parse granted QoSes
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packet.granted = []
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while (this._pos < this.packet.length) {
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const code = this._list.readUInt8(this._pos++)
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if (!constants.MQTT5_UNSUBACK_CODES[code]) {
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return this._emitError(new Error('Invalid unsuback code'))
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}
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this.packet.granted.push(code)
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}
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}
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}
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// parse packets like puback, pubrec, pubrel, pubcomp
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_parseConfirmation () {
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debug('_parseConfirmation: packet.cmd: `%s`', this.packet.cmd)
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const packet = this.packet
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this._parseMessageId()
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if (this.settings.protocolVersion === 5) {
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if (packet.length > 2) {
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// response code
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packet.reasonCode = this._parseByte()
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switch (this.packet.cmd) {
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case 'puback':
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case 'pubrec':
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if (!constants.MQTT5_PUBACK_PUBREC_CODES[packet.reasonCode]) {
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return this._emitError(new Error('Invalid ' + this.packet.cmd + ' reason code'))
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}
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break
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case 'pubrel':
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case 'pubcomp':
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if (!constants.MQTT5_PUBREL_PUBCOMP_CODES[packet.reasonCode]) {
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return this._emitError(new Error('Invalid ' + this.packet.cmd + ' reason code'))
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}
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break
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}
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debug('_parseConfirmation: packet.reasonCode `%d`', packet.reasonCode)
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} else {
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packet.reasonCode = 0
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}
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if (packet.length > 3) {
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// properies mqtt 5
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const properties = this._parseProperties()
|
|
if (Object.getOwnPropertyNames(properties).length) {
|
|
packet.properties = properties
|
|
}
|
|
}
|
|
}
|
|
|
|
return true
|
|
}
|
|
|
|
// parse disconnect packet
|
|
_parseDisconnect () {
|
|
const packet = this.packet
|
|
debug('_parseDisconnect')
|
|
|
|
if (this.settings.protocolVersion === 5) {
|
|
// response code
|
|
if (this._list.length > 0) {
|
|
packet.reasonCode = this._parseByte()
|
|
if (!constants.MQTT5_DISCONNECT_CODES[packet.reasonCode]) {
|
|
this._emitError(new Error('Invalid disconnect reason code'))
|
|
}
|
|
} else {
|
|
packet.reasonCode = 0
|
|
}
|
|
// properies mqtt 5
|
|
const properties = this._parseProperties()
|
|
if (Object.getOwnPropertyNames(properties).length) {
|
|
packet.properties = properties
|
|
}
|
|
}
|
|
|
|
debug('_parseDisconnect result: true')
|
|
return true
|
|
}
|
|
|
|
// parse auth packet
|
|
_parseAuth () {
|
|
debug('_parseAuth')
|
|
const packet = this.packet
|
|
|
|
if (this.settings.protocolVersion !== 5) {
|
|
return this._emitError(new Error('Not supported auth packet for this version MQTT'))
|
|
}
|
|
|
|
// response code
|
|
packet.reasonCode = this._parseByte()
|
|
if (!constants.MQTT5_AUTH_CODES[packet.reasonCode]) {
|
|
return this._emitError(new Error('Invalid auth reason code'))
|
|
}
|
|
// properies mqtt 5
|
|
const properties = this._parseProperties()
|
|
if (Object.getOwnPropertyNames(properties).length) {
|
|
packet.properties = properties
|
|
}
|
|
|
|
debug('_parseAuth: result: true')
|
|
return true
|
|
}
|
|
|
|
_parseMessageId () {
|
|
const packet = this.packet
|
|
|
|
packet.messageId = this._parseNum()
|
|
|
|
if (packet.messageId === null) {
|
|
this._emitError(new Error('Cannot parse messageId'))
|
|
return false
|
|
}
|
|
|
|
debug('_parseMessageId: packet.messageId %d', packet.messageId)
|
|
return true
|
|
}
|
|
|
|
_parseString (maybeBuffer) {
|
|
const length = this._parseNum()
|
|
const end = length + this._pos
|
|
|
|
if (length === -1 || end > this._list.length || end > this.packet.length) return null
|
|
|
|
const result = this._list.toString('utf8', this._pos, end)
|
|
this._pos += length
|
|
debug('_parseString: result: %s', result)
|
|
return result
|
|
}
|
|
|
|
_parseStringPair () {
|
|
debug('_parseStringPair')
|
|
return {
|
|
name: this._parseString(),
|
|
value: this._parseString()
|
|
}
|
|
}
|
|
|
|
_parseBuffer () {
|
|
const length = this._parseNum()
|
|
const end = length + this._pos
|
|
|
|
if (length === -1 || end > this._list.length || end > this.packet.length) return null
|
|
|
|
const result = this._list.slice(this._pos, end)
|
|
|
|
this._pos += length
|
|
debug('_parseBuffer: result: %o', result)
|
|
return result
|
|
}
|
|
|
|
_parseNum () {
|
|
if (this._list.length - this._pos < 2) return -1
|
|
|
|
const result = this._list.readUInt16BE(this._pos)
|
|
this._pos += 2
|
|
debug('_parseNum: result: %s', result)
|
|
return result
|
|
}
|
|
|
|
_parse4ByteNum () {
|
|
if (this._list.length - this._pos < 4) return -1
|
|
|
|
const result = this._list.readUInt32BE(this._pos)
|
|
this._pos += 4
|
|
debug('_parse4ByteNum: result: %s', result)
|
|
return result
|
|
}
|
|
|
|
_parseVarByteNum (fullInfoFlag) {
|
|
debug('_parseVarByteNum')
|
|
const maxBytes = 4
|
|
let bytes = 0
|
|
let mul = 1
|
|
let value = 0
|
|
let result = false
|
|
let current
|
|
const padding = this._pos ? this._pos : 0
|
|
|
|
while (bytes < maxBytes && (padding + bytes) < this._list.length) {
|
|
current = this._list.readUInt8(padding + bytes++)
|
|
value += mul * (current & constants.VARBYTEINT_MASK)
|
|
mul *= 0x80
|
|
|
|
if ((current & constants.VARBYTEINT_FIN_MASK) === 0) {
|
|
result = true
|
|
break
|
|
}
|
|
if (this._list.length <= bytes) {
|
|
break
|
|
}
|
|
}
|
|
|
|
if (!result && bytes === maxBytes && this._list.length >= bytes) {
|
|
this._emitError(new Error('Invalid variable byte integer'))
|
|
}
|
|
|
|
if (padding) {
|
|
this._pos += bytes
|
|
}
|
|
|
|
if (result) {
|
|
if (fullInfoFlag) {
|
|
result = { bytes, value }
|
|
} else {
|
|
result = value
|
|
}
|
|
} else {
|
|
result = false
|
|
}
|
|
|
|
debug('_parseVarByteNum: result: %o', result)
|
|
return result
|
|
}
|
|
|
|
_parseByte () {
|
|
let result
|
|
if (this._pos < this._list.length) {
|
|
result = this._list.readUInt8(this._pos)
|
|
this._pos++
|
|
}
|
|
debug('_parseByte: result: %o', result)
|
|
return result
|
|
}
|
|
|
|
_parseByType (type) {
|
|
debug('_parseByType: type: %s', type)
|
|
switch (type) {
|
|
case 'byte': {
|
|
return this._parseByte() !== 0
|
|
}
|
|
case 'int8': {
|
|
return this._parseByte()
|
|
}
|
|
case 'int16': {
|
|
return this._parseNum()
|
|
}
|
|
case 'int32': {
|
|
return this._parse4ByteNum()
|
|
}
|
|
case 'var': {
|
|
return this._parseVarByteNum()
|
|
}
|
|
case 'string': {
|
|
return this._parseString()
|
|
}
|
|
case 'pair': {
|
|
return this._parseStringPair()
|
|
}
|
|
case 'binary': {
|
|
return this._parseBuffer()
|
|
}
|
|
}
|
|
}
|
|
|
|
_parseProperties () {
|
|
debug('_parseProperties')
|
|
const length = this._parseVarByteNum()
|
|
const start = this._pos
|
|
const end = start + length
|
|
const result = {}
|
|
while (this._pos < end) {
|
|
const type = this._parseByte()
|
|
if (!type) {
|
|
this._emitError(new Error('Cannot parse property code type'))
|
|
return false
|
|
}
|
|
const name = constants.propertiesCodes[type]
|
|
if (!name) {
|
|
this._emitError(new Error('Unknown property'))
|
|
return false
|
|
}
|
|
// user properties process
|
|
if (name === 'userProperties') {
|
|
if (!result[name]) {
|
|
result[name] = Object.create(null)
|
|
}
|
|
const currentUserProperty = this._parseByType(constants.propertiesTypes[name])
|
|
if (result[name][currentUserProperty.name]) {
|
|
if (Array.isArray(result[name][currentUserProperty.name])) {
|
|
result[name][currentUserProperty.name].push(currentUserProperty.value)
|
|
} else {
|
|
const currentValue = result[name][currentUserProperty.name]
|
|
result[name][currentUserProperty.name] = [currentValue]
|
|
result[name][currentUserProperty.name].push(currentUserProperty.value)
|
|
}
|
|
} else {
|
|
result[name][currentUserProperty.name] = currentUserProperty.value
|
|
}
|
|
continue
|
|
}
|
|
if (result[name]) {
|
|
if (Array.isArray(result[name])) {
|
|
result[name].push(this._parseByType(constants.propertiesTypes[name]))
|
|
} else {
|
|
result[name] = [result[name]]
|
|
result[name].push(this._parseByType(constants.propertiesTypes[name]))
|
|
}
|
|
} else {
|
|
result[name] = this._parseByType(constants.propertiesTypes[name])
|
|
}
|
|
}
|
|
return result
|
|
}
|
|
|
|
_newPacket () {
|
|
debug('_newPacket')
|
|
if (this.packet) {
|
|
this._list.consume(this.packet.length)
|
|
debug('_newPacket: parser emit packet: packet.cmd: %s, packet.payload: %s, packet.length: %d', this.packet.cmd, this.packet.payload, this.packet.length)
|
|
this.emit('packet', this.packet)
|
|
}
|
|
debug('_newPacket: new packet')
|
|
this.packet = new Packet()
|
|
|
|
this._pos = 0
|
|
|
|
return true
|
|
}
|
|
|
|
_emitError (err) {
|
|
debug('_emitError', err)
|
|
this.error = err
|
|
this.emit('error', err)
|
|
}
|
|
}
|
|
|
|
module.exports = Parser
|