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package packets
import (
"bytes"
"fmt"
"github.com/pborman/uuid"
"io"
)
//ConnectPacket is an internal representation of the fields of the
//Connect MQTT packet
type ConnectPacket struct {
FixedHeader
ProtocolName string
ProtocolVersion byte
CleanSession bool
WillFlag bool
WillQos byte
WillRetain bool
UsernameFlag bool
PasswordFlag bool
ReservedBit byte
KeepaliveTimer uint16
ClientIdentifier string
WillTopic string
WillMessage []byte
Username string
Password []byte
uuid uuid.UUID
}
func (c *ConnectPacket) String() string {
str := fmt.Sprintf("%s\n", c.FixedHeader)
str += fmt.Sprintf("protocolversion: %d protocolname: %s cleansession: %t willflag: %t WillQos: %d WillRetain: %t Usernameflag: %t Passwordflag: %t keepalivetimer: %d\nclientId: %s\nwilltopic: %s\nwillmessage: %s\nUsername: %s\nPassword: %s\n", c.ProtocolVersion, c.ProtocolName, c.CleanSession, c.WillFlag, c.WillQos, c.WillRetain, c.UsernameFlag, c.PasswordFlag, c.KeepaliveTimer, c.ClientIdentifier, c.WillTopic, c.WillMessage, c.Username, c.Password)
return str
}
func (c *ConnectPacket) Write(w io.Writer) error {
var body bytes.Buffer
var err error
body.Write(encodeString(c.ProtocolName))
body.WriteByte(c.ProtocolVersion)
body.WriteByte(boolToByte(c.CleanSession)<<1 | boolToByte(c.WillFlag)<<2 | c.WillQos<<3 | boolToByte(c.WillRetain)<<5 | boolToByte(c.PasswordFlag)<<6 | boolToByte(c.UsernameFlag)<<7)
body.Write(encodeUint16(c.KeepaliveTimer))
body.Write(encodeString(c.ClientIdentifier))
if c.WillFlag {
body.Write(encodeString(c.WillTopic))
body.Write(encodeBytes(c.WillMessage))
}
if c.UsernameFlag {
body.Write(encodeString(c.Username))
}
if c.PasswordFlag {
body.Write(encodeBytes(c.Password))
}
c.FixedHeader.RemainingLength = body.Len()
packet := c.FixedHeader.pack()
packet.Write(body.Bytes())
_, err = packet.WriteTo(w)
return err
}
//Unpack decodes the details of a ControlPacket after the fixed
//header has been read
func (c *ConnectPacket) Unpack(b io.Reader) {
c.ProtocolName = decodeString(b)
c.ProtocolVersion = decodeByte(b)
options := decodeByte(b)
c.ReservedBit = 1 & options
c.CleanSession = 1&(options>>1) > 0
c.WillFlag = 1&(options>>2) > 0
c.WillQos = 3 & (options >> 3)
c.WillRetain = 1&(options>>5) > 0
c.PasswordFlag = 1&(options>>6) > 0
c.UsernameFlag = 1&(options>>7) > 0
c.KeepaliveTimer = decodeUint16(b)
c.ClientIdentifier = decodeString(b)
if c.WillFlag {
c.WillTopic = decodeString(b)
c.WillMessage = decodeBytes(b)
}
if c.UsernameFlag {
c.Username = decodeString(b)
}
if c.PasswordFlag {
c.Password = decodeBytes(b)
}
}
//Validate performs validation of the fields of a Connect packet
func (c *ConnectPacket) Validate() byte {
if c.PasswordFlag && !c.UsernameFlag {
return ErrRefusedBadUsernameOrPassword
}
if c.ReservedBit != 0 {
//Bad reserved bit
return ErrProtocolViolation
}
if (c.ProtocolName == "MQIsdp" && c.ProtocolVersion != 3) || (c.ProtocolName == "MQTT" && c.ProtocolVersion != 4) {
//Mismatched or unsupported protocol version
return ErrRefusedBadProtocolVersion
}
if c.ProtocolName != "MQIsdp" && c.ProtocolName != "MQTT" {
//Bad protocol name
return ErrProtocolViolation
}
if len(c.ClientIdentifier) > 65535 || len(c.Username) > 65535 || len(c.Password) > 65535 {
//Bad size field
return ErrProtocolViolation
}
return Accepted
}
//Details returns a Details struct containing the Qos and
//MessageID of this ControlPacket
func (c *ConnectPacket) Details() Details {
return Details{Qos: 0, MessageID: 0}
}
//UUID returns the unique ID assigned to the ControlPacket when
//it was originally received. Note: this is not related to the
//MessageID field for MQTT packets
func (c *ConnectPacket) UUID() uuid.UUID {
return c.uuid
}
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