Class: Protocol::MQTT::Packet::Connect

Inherits:
Protocol::MQTT::Packet show all
Defined in:
lib/protocol/mqtt/packet/connect.rb

Overview

CONNECT (§3.1) — first packet on every connection, identifies the client.

Variable header: protocol_name (utf8) + protocol_level (u8) + connect_flags (u8) + keep_alive (u16) + v5 property block.

Payload (ordered): client_id, [v5 will_properties], [will_topic, will_payload], [username], [password].

will is either nil or a Hash:

{ topic:, payload:, qos: 0, retain: false, properties: {} }

Constant Summary collapse

TYPE_ID = 
CONNECT
PROTOCOL_NAME = 
"MQTT"
FLAG_USER_NAME =

Connect flag bits

0b10000000
FLAG_PASSWORD = 
0b01000000
FLAG_WILL_RETAIN = 
0b00100000
FLAG_WILL_QOS_MASK = 
0b00011000
FLAG_WILL_QOS_SHIFT = 
3
FLAG_WILL = 
0b00000100
FLAG_CLEAN_START = 
0b00000010

Constants inherited from Protocol::MQTT::Packet

AUTH, CONNACK, CONNECT, DISCONNECT, PINGREQ, PINGRESP, PUBACK, PUBCOMP, PUBLISH, PUBREC, PUBREL, SUBACK, SUBSCRIBE, UNSUBACK, UNSUBSCRIBE

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Protocol::MQTT::Packet

decode, decode_from_body, #encode, encode_packet, #flags_nibble, register

Constructor Details

#initialize(client_id:, clean_start: true, keep_alive: 0, username: nil, password: nil, will: nil, properties: {}) ⇒ Connect

Returns a new instance of Connect.



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# File 'lib/protocol/mqtt/packet/connect.rb', line 38

def initialize(client_id:, clean_start: true, keep_alive: 0,
               username: nil, password: nil, will: nil, properties: {})
  @client_id   = client_id
  @clean_start = clean_start
  @keep_alive  = keep_alive
  @username    = username
  @password    = password
  @will        = will ? normalize_will(will) : nil
  @properties  = properties
end

Instance Attribute Details

#clean_start ⇒ Object (readonly)

Returns the value of attribute clean_start.



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# File 'lib/protocol/mqtt/packet/connect.rb', line 34

def clean_start
  @clean_start
end

#client_id ⇒ Object (readonly)

Returns the value of attribute client_id.



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# File 'lib/protocol/mqtt/packet/connect.rb', line 34

def client_id
  @client_id
end

#keep_alive ⇒ Object (readonly)

Returns the value of attribute keep_alive.



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# File 'lib/protocol/mqtt/packet/connect.rb', line 34

def keep_alive
  @keep_alive
end

#password ⇒ Object (readonly)

Returns the value of attribute password.



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# File 'lib/protocol/mqtt/packet/connect.rb', line 34

def password
  @password
end

#properties ⇒ Object (readonly)

Returns the value of attribute properties.



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# File 'lib/protocol/mqtt/packet/connect.rb', line 34

def properties
  @properties
end

#username ⇒ Object (readonly)

Returns the value of attribute username.



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# File 'lib/protocol/mqtt/packet/connect.rb', line 34

def username
  @username
end

#will ⇒ Object (readonly)

Returns the value of attribute will.



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# File 'lib/protocol/mqtt/packet/connect.rb', line 34

def will
  @will
end

Class Method Details

.decode_body(reader, flags:, version:) ⇒ Object

Raises:



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# File 'lib/protocol/mqtt/packet/connect.rb', line 105

def self.decode_body(reader, flags:, version:)
  protocol_name = reader.read_utf8
  protocol_level = reader.read_u8
  raise MalformedPacket, "unsupported protocol name: #{protocol_name.inspect}" unless protocol_name == PROTOCOL_NAME
  wire_version = protocol_level == 5 ? 5 : protocol_level == 4 ? 3 : nil
  raise MalformedPacket, "unsupported protocol level: #{protocol_level}" unless wire_version

  connect_flags = reader.read_u8
  raise MalformedPacket, "reserved connect flag bit must be 0" if (connect_flags & 0b1) != 0
  keep_alive = reader.read_u16
  properties = wire_version == 5 ? Property.decode(reader) : {}

  client_id = reader.read_utf8

  will = nil
  if (connect_flags & FLAG_WILL) != 0
    will_qos = (connect_flags & FLAG_WILL_QOS_MASK) >> FLAG_WILL_QOS_SHIFT
    raise MalformedPacket, "invalid Will QoS 3" if will_qos == 3
    will_retain = (connect_flags & FLAG_WILL_RETAIN) != 0
    will_props = wire_version == 5 ? Property.decode(reader) : {}
    will_topic = reader.read_utf8
    will_payload = reader.read_binary
    will = {
      topic: will_topic,
      payload: will_payload,
      qos: will_qos,
      retain: will_retain,
      properties: will_props,
    }
  elsif (connect_flags & FLAG_WILL_RETAIN) != 0
    raise MalformedPacket, "Will Retain set without Will Flag"
  end

  username = (connect_flags & FLAG_USER_NAME) != 0 ? reader.read_utf8 : nil
  password = (connect_flags & FLAG_PASSWORD) != 0 ? reader.read_binary : nil

  new(
    client_id:   client_id,
    clean_start: (connect_flags & FLAG_CLEAN_START) != 0,
    keep_alive:  keep_alive,
    username:    username,
    password:    password,
    will:        will,
    properties:  properties,
  )
end

.peek_protocol_level(body_bytes) ⇒ Object

Peeks the Protocol Level byte (4 = v3.1.1, 5 = v5) from a raw CONNECT body. Used by brokers to pick the wire version before full decode. Does not consume from body_bytes.

Raises:



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# File 'lib/protocol/mqtt/packet/connect.rb', line 65

def self.peek_protocol_level(body_bytes)
  r = Codec::Reader.new(body_bytes)
  name = r.read_utf8
  raise MalformedPacket, "expected MQTT protocol name, got #{name.inspect}" unless name == PROTOCOL_NAME
  r.read_u8
end

Instance Method Details

#==(other) ⇒ Object Also known as: eql? 



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# File 'lib/protocol/mqtt/packet/connect.rb', line 153

def ==(other)
  other.is_a?(Connect) &&
    other.client_id == @client_id &&
    other.clean_start == @clean_start &&
    other.keep_alive == @keep_alive &&
    other.username == @username &&
    other.password == @password &&
    other.will == @will &&
    other.properties == @properties
end

#encode_body(version) ⇒ Object

Raises:



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# File 'lib/protocol/mqtt/packet/connect.rb', line 73

def encode_body(version)
  raise ProtocolError, "CONNECT requires version 3 or 5, got #{version}" unless [3, 5].include?(version)
  w = Codec::Writer.new
  w.write_utf8(PROTOCOL_NAME)
  w.write_u8(version == 5 ? 5 : 4)

  flags = 0
  flags |= FLAG_USER_NAME    if @username
  flags |= FLAG_PASSWORD     if @password
  flags |= FLAG_CLEAN_START  if @clean_start
  if @will
    flags |= FLAG_WILL
    flags |= (@will.fetch(:qos, 0) & 0b11) << FLAG_WILL_QOS_SHIFT
    flags |= FLAG_WILL_RETAIN if @will[:retain]
  end
  w.write_u8(flags)

  w.write_u16(@keep_alive)
  w.write(Property.encode(@properties)) if version == 5

  w.write_utf8(@client_id)
  if @will
    w.write(Property.encode(@will.fetch(:properties, {}))) if version == 5
    w.write_utf8(@will.fetch(:topic))
    w.write_binary(@will.fetch(:payload))
  end
  w.write_utf8(@username) if @username
  w.write_binary(@password) if @password
  w.bytes
end

#hash ⇒ Object 



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# File 'lib/protocol/mqtt/packet/connect.rb', line 166

def hash
  [self.class, @client_id, @clean_start, @keep_alive, @username, @password, @will, @properties].hash
end