| /******************************************************************************* |
| * Copyright (c) 2014-2015 IBM Corp. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * Allan Stockdill-Mander - initial API and implementation |
| *******************************************************************************/ |
| |
| /* |
| Package smidge/packets provides de/serialisation of MQTTSN packets |
| */ |
| |
| package packets |
| |
| import ( |
| "bytes" |
| "encoding/binary" |
| "errors" |
| "io" |
| ) |
| |
| type Message interface { |
| MessageType() byte |
| Write(io.Writer) error |
| Unpack(io.Reader) |
| //String() string |
| //Details() Details |
| //UUID() uuid.UUID |
| } |
| |
| type Header struct { |
| Length uint16 |
| MessageType byte |
| } |
| |
| func ReadPacket(r io.Reader) (m Message, err error) { |
| var h Header |
| packet := make([]byte, 1500) |
| r.Read(packet) |
| packetBuf := bytes.NewBuffer(packet) |
| h.unpack(packetBuf) |
| m = NewMessageWithHeader(h) |
| if m == nil { |
| return nil, errors.New("Bad data from client") |
| } |
| m.Unpack(packetBuf) |
| return m, nil |
| } |
| |
| func (h *Header) unpack(b io.Reader) { |
| lengthCheck := readByte(b) |
| if lengthCheck == 0x01 { |
| h.Length = readUint16(b) |
| } else { |
| h.Length = uint16(lengthCheck) |
| } |
| h.MessageType = readByte(b) |
| } |
| |
| func (h *Header) pack() bytes.Buffer { |
| var header bytes.Buffer |
| if h.Length > 256 { |
| h.Length += 2 |
| header.WriteByte(0x01) |
| header.Write(encodeUint16(h.Length)) |
| } else { |
| header.WriteByte(byte(h.Length)) |
| } |
| return header |
| } |
| |
| func NewMessage(msgType byte) (m Message) { |
| switch msgType { |
| case ADVERTISE: |
| m = &AdvertiseMessage{Header: Header{MessageType: ADVERTISE, Length: 5}} |
| case SEARCHGW: |
| m = &SearchGwMessage{Header: Header{MessageType: SEARCHGW, Length: 3}} |
| case GWINFO: |
| m = &GwInfoMessage{Header: Header{MessageType: GWINFO}} |
| case CONNECT: |
| m = &ConnectMessage{Header: Header{MessageType: CONNECT}, ProtocolId: 0x01} |
| case CONNACK: |
| m = &ConnackMessage{Header: Header{MessageType: CONNACK, Length: 3}} |
| case WILLTOPICREQ: |
| m = &WillTopicReqMessage{Header: Header{MessageType: WILLTOPICREQ, Length: 2}} |
| case WILLTOPIC: |
| m = &WillTopicMessage{Header: Header{MessageType: WILLTOPIC}} |
| case WILLMSGREQ: |
| m = &WillMsgReqMessage{Header: Header{MessageType: WILLMSGREQ, Length: 2}} |
| case WILLMSG: |
| m = &WillMsgMessage{Header: Header{MessageType: WILLMSG}} |
| case REGISTER: |
| m = &RegisterMessage{Header: Header{MessageType: REGISTER}} |
| case REGACK: |
| m = &RegackMessage{Header: Header{MessageType: REGACK, Length: 7}} |
| case PUBLISH: |
| m = &PublishMessage{Header: Header{MessageType: PUBLISH}} |
| case PUBACK: |
| m = &PubackMessage{Header: Header{MessageType: PUBACK, Length: 7}} |
| case PUBCOMP: |
| m = &PubcompMessage{Header: Header{MessageType: PUBCOMP, Length: 4}} |
| case PUBREC: |
| m = &PubrecMessage{Header: Header{MessageType: PUBREC, Length: 4}} |
| case PUBREL: |
| m = &PubrelMessage{Header: Header{MessageType: PUBREL, Length: 4}} |
| case SUBSCRIBE: |
| m = &SubscribeMessage{Header: Header{MessageType: SUBSCRIBE}} |
| case SUBACK: |
| m = &SubackMessage{Header: Header{MessageType: SUBACK, Length: 8}} |
| case UNSUBSCRIBE: |
| m = &UnsubscribeMessage{Header: Header{MessageType: UNSUBSCRIBE}} |
| case UNSUBACK: |
| m = &UnsubackMessage{Header: Header{MessageType: UNSUBACK, Length: 4}} |
| case PINGREQ: |
| m = &PingreqMessage{Header: Header{MessageType: PINGREQ}} |
| case PINGRESP: |
| m = &PingrespMessage{Header: Header{MessageType: PINGRESP, Length: 2}} |
| case DISCONNECT: |
| m = &DisconnectMessage{Header: Header{MessageType: DISCONNECT}} |
| case WILLTOPICUPD: |
| m = &WillTopicUpdateMessage{Header: Header{MessageType: WILLTOPICUPD}} |
| case WILLTOPICRESP: |
| m = &WillTopicRespMessage{Header: Header{MessageType: WILLTOPICRESP, Length: 3}} |
| case WILLMSGUPD: |
| m = &WillMsgUpdateMessage{Header: Header{MessageType: WILLMSGUPD}} |
| case WILLMSGRESP: |
| m = &WillMsgRespMessage{Header: Header{MessageType: WILLMSGRESP, Length: 3}} |
| } |
| return |
| } |
| |
| func NewMessageWithHeader(h Header) (m Message) { |
| switch h.MessageType { |
| case ADVERTISE: |
| m = &AdvertiseMessage{Header: h} |
| case SEARCHGW: |
| m = &SearchGwMessage{Header: h} |
| case GWINFO: |
| m = &GwInfoMessage{Header: h} |
| case CONNECT: |
| m = &ConnectMessage{Header: h} |
| case CONNACK: |
| m = &ConnackMessage{Header: h} |
| case WILLTOPICREQ: |
| m = &WillTopicReqMessage{Header: h} |
| case WILLTOPIC: |
| m = &WillTopicMessage{Header: h} |
| case WILLMSGREQ: |
| m = &WillMsgReqMessage{Header: h} |
| case WILLMSG: |
| m = &WillMsgMessage{Header: h} |
| case REGISTER: |
| m = &RegisterMessage{Header: h} |
| case REGACK: |
| m = &RegackMessage{Header: h} |
| case PUBLISH: |
| m = &PublishMessage{Header: h} |
| case PUBACK: |
| m = &PubackMessage{Header: h} |
| case PUBCOMP: |
| m = &PubcompMessage{Header: h} |
| case PUBREC: |
| m = &PubrecMessage{Header: h} |
| case PUBREL: |
| m = &PubrelMessage{Header: h} |
| case SUBSCRIBE: |
| m = &SubscribeMessage{Header: h} |
| case SUBACK: |
| m = &SubackMessage{Header: h} |
| case UNSUBSCRIBE: |
| m = &UnsubscribeMessage{Header: h} |
| case UNSUBACK: |
| m = &UnsubackMessage{Header: h} |
| case PINGREQ: |
| m = &PingreqMessage{Header: h} |
| case PINGRESP: |
| m = &PingrespMessage{Header: h} |
| case DISCONNECT: |
| m = &DisconnectMessage{Header: h} |
| case WILLTOPICUPD: |
| m = &WillTopicUpdateMessage{Header: h} |
| case WILLTOPICRESP: |
| m = &WillTopicRespMessage{Header: h} |
| case WILLMSGUPD: |
| m = &WillMsgUpdateMessage{Header: h} |
| case WILLMSGRESP: |
| m = &WillMsgRespMessage{Header: h} |
| } |
| return |
| } |
| |
| func readByte(b io.Reader) byte { |
| num := make([]byte, 1) |
| b.Read(num) |
| return num[0] |
| } |
| |
| func readUint16(b io.Reader) uint16 { |
| num := make([]byte, 2) |
| b.Read(num) |
| return binary.BigEndian.Uint16(num) |
| } |
| |
| func encodeUint16(num uint16) []byte { |
| bytes := make([]byte, 2) |
| binary.BigEndian.PutUint16(bytes, num) |
| return bytes |
| } |
| |
| // Flags |
| const ( |
| TOPICIDTYPE = 0x03 |
| CLEANSESSION = 0x04 |
| WILLFLAG = 0x08 |
| RETAINFLAG = 0x10 |
| QOSBITS = 0x60 |
| DUPFLAG = 0x80 |
| ) |
| |
| // Errors |
| const ( |
| ACCEPTED = 0x00 |
| REJ_CONGESTION = 0x01 |
| REJ_INVALID_TID = 0x02 |
| REJ_NOT_SUPORTED = 0x03 |
| ) |
| |
| // Message Types |
| const ( |
| ADVERTISE = 0x00 |
| SEARCHGW = 0x01 |
| GWINFO = 0x02 |
| CONNECT = 0x04 |
| CONNACK = 0x05 |
| WILLTOPICREQ = 0x06 |
| WILLTOPIC = 0x07 |
| WILLMSGREQ = 0x08 |
| WILLMSG = 0x09 |
| REGISTER = 0x0A |
| REGACK = 0x0B |
| PUBLISH = 0x0C |
| PUBACK = 0x0D |
| PUBCOMP = 0x0E |
| PUBREC = 0x0F |
| PUBREL = 0x10 |
| SUBSCRIBE = 0x12 |
| SUBACK = 0x13 |
| UNSUBSCRIBE = 0x14 |
| UNSUBACK = 0x15 |
| PINGREQ = 0x16 |
| PINGRESP = 0x17 |
| DISCONNECT = 0x18 |
| WILLTOPICUPD = 0x1A |
| WILLTOPICRESP = 0x1B |
| WILLMSGUPD = 0x1C |
| WILLMSGRESP = 0x1D |
| // 0x03 is reserved |
| // 0x11 is reserved |
| // 0x19 is reserved |
| // 0x1E - 0xFD is reserved |
| // 0xFE - Encapsulated message |
| // 0xFF is reserved |
| ) |
| |
| var MessageNames = map[byte]string{ |
| ADVERTISE: "ADVERTISE", |
| SEARCHGW: "SEARCHGW", |
| GWINFO: "GWINFO", |
| CONNECT: "CONNECT", |
| CONNACK: "CONNACK", |
| WILLTOPICREQ: "WILLTOPICREQ", |
| WILLTOPIC: "WILLTOPIC", |
| WILLMSGREQ: "WILLMSGREQ", |
| WILLMSG: "WILLMSG", |
| REGISTER: "REGISTER", |
| REGACK: "REGACK", |
| PUBLISH: "PUBLISH", |
| PUBACK: "PUBACK", |
| PUBCOMP: "PUBCOMP", |
| PUBREC: "PUBREC", |
| PUBREL: "PUBREL", |
| SUBSCRIBE: "SUBSCRIBE", |
| SUBACK: "SUBACK", |
| UNSUBSCRIBE: "UNSUBSCRIBE", |
| UNSUBACK: "UNSUBACK", |
| PINGREQ: "PINGREQ", |
| PINGRESP: "PINGRESP", |
| DISCONNECT: "DISCONNECT", |
| WILLTOPICUPD: "WILLTOPICUPD", |
| WILLTOPICRESP: "WILLTOPICRESP", |
| WILLMSGUPD: "WILLMSGUPD", |
| WILLMSGRESP: "WILLMSGRESP", |
| } |
