robocar-steering/vendor/github.com/eclipse/paho.mqtt.golang/packets/connect.go

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2022-06-09 13:59:30 +00:00
/*
* Copyright (c) 2021 IBM Corp and others.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v2.0
* and Eclipse Distribution License v1.0 which accompany this distribution.
*
* The Eclipse Public License is available at
* https://www.eclipse.org/legal/epl-2.0/
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Allan Stockdill-Mander
*/
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package packets
import (
"bytes"
"fmt"
"io"
)
// ConnectPacket is an internal representation of the fields of the
// Connect MQTT packet
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type ConnectPacket struct {
FixedHeader
ProtocolName string
ProtocolVersion byte
CleanSession bool
WillFlag bool
WillQos byte
WillRetain bool
UsernameFlag bool
PasswordFlag bool
ReservedBit byte
Keepalive uint16
ClientIdentifier string
WillTopic string
WillMessage []byte
Username string
Password []byte
}
func (c *ConnectPacket) String() string {
var password string
if len(c.Password) > 0 {
password = "<redacted>"
}
return fmt.Sprintf("%s protocolversion: %d protocolname: %s cleansession: %t willflag: %t WillQos: %d WillRetain: %t Usernameflag: %t Passwordflag: %t keepalive: %d clientId: %s willtopic: %s willmessage: %s Username: %s Password: %s", c.FixedHeader, c.ProtocolVersion, c.ProtocolName, c.CleanSession, c.WillFlag, c.WillQos, c.WillRetain, c.UsernameFlag, c.PasswordFlag, c.Keepalive, c.ClientIdentifier, c.WillTopic, c.WillMessage, c.Username, password)
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}
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.Keepalive))
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
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func (c *ConnectPacket) Unpack(b io.Reader) error {
var err error
c.ProtocolName, err = decodeString(b)
if err != nil {
return err
}
c.ProtocolVersion, err = decodeByte(b)
if err != nil {
return err
}
options, err := decodeByte(b)
if err != nil {
return err
}
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.Keepalive, err = decodeUint16(b)
if err != nil {
return err
}
c.ClientIdentifier, err = decodeString(b)
if err != nil {
return err
}
if c.WillFlag {
c.WillTopic, err = decodeString(b)
if err != nil {
return err
}
c.WillMessage, err = decodeBytes(b)
if err != nil {
return err
}
}
if c.UsernameFlag {
c.Username, err = decodeString(b)
if err != nil {
return err
}
}
if c.PasswordFlag {
c.Password, err = decodeBytes(b)
if err != nil {
return err
}
}
return nil
}
// Validate performs validation of the fields of a Connect packet
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func (c *ConnectPacket) Validate() byte {
if c.PasswordFlag && !c.UsernameFlag {
return ErrRefusedBadUsernameOrPassword
}
if c.ReservedBit != 0 {
// Bad reserved bit
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return ErrProtocolViolation
}
if (c.ProtocolName == "MQIsdp" && c.ProtocolVersion != 3) || (c.ProtocolName == "MQTT" && c.ProtocolVersion != 4) {
// Mismatched or unsupported protocol version
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return ErrRefusedBadProtocolVersion
}
if c.ProtocolName != "MQIsdp" && c.ProtocolName != "MQTT" {
// Bad protocol name
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return ErrProtocolViolation
}
if len(c.ClientIdentifier) > 65535 || len(c.Username) > 65535 || len(c.Password) > 65535 {
// Bad size field
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return ErrProtocolViolation
}
if len(c.ClientIdentifier) == 0 && !c.CleanSession {
// Bad client identifier
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return ErrRefusedIDRejected
}
return Accepted
}
// Details returns a Details struct containing the Qos and
// MessageID of this ControlPacket
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func (c *ConnectPacket) Details() Details {
return Details{Qos: 0, MessageID: 0}
}