Initial session handling

connection.go

@@ -0,0 +1,92 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"time"
+
+	"badat.dev/maeqtt/v2/mqtt/packets"
+)
+
+type Connection struct {
+	MaxPacketSize   *uint32
+	RecvMax         uint16
+	TopicAliasMax   uint16
+	WantsRespInf    bool
+	WantsProblemInf bool
+	Will            packets.Will
+
+	KeepAliveInterval time.Duration
+	keepAliveTicker   time.Ticker
+
+	PacketChannel          chan packets.ClientPacket
+	ClientDisconnectedChan chan bool
+
+	rw io.ReadWriteCloser
+}
+
+func (c *Connection) resetKeepAlive() {
+	if c.KeepAliveInterval != 0 {
+		// TODO IMPLEMENT THIS
+		//s.keepAliveTicker.Reset(s.KeepAliveInterval)
+	}
+}
+
+func (c *Connection) readPacket() (*packets.ClientPacket, error) {
+	return packets.ReadPacket(bufio.NewReader(c.rw))
+}
+
+func (c *Connection) sendPacket(p packets.ServerPacket) error {
+	c.resetKeepAlive()
+	return p.Write(c.rw)
+}
+
+func (c *Connection) close() error {
+	close(c.PacketChannel)
+	return c.rw.Close()
+}
+
+func (c *Connection) packetReadLoop() {
+	for {
+		pack, err := c.readPacket()
+		if err == io.EOF {
+			c.ClientDisconnectedChan <- true
+		} else if err != nil {
+			panic(fmt.Errorf("Unimplemented error handling, %e", err).Error())
+		} else {
+			c.PacketChannel <- *pack
+		}
+	}
+}
+
+func NewConnection(p packets.ConnectPacket, rw io.ReadWriteCloser) Connection {
+	conn := Connection{}
+	conn.rw = rw
+
+	if p.Properties.ReceiveMaximum.Value != nil {
+		conn.RecvMax = *p.Properties.ReceiveMaximum.Value
+	} else {
+		conn.RecvMax = 65535
+	}
+	conn.MaxPacketSize = p.Properties.MaximumPacketSize.Value
+
+	if p.Properties.TopicAliasMaximum.Value != nil {
+		conn.TopicAliasMax = *p.Properties.TopicAliasMaximum.Value
+	} else {
+		conn.TopicAliasMax = 0
+	}
+
+	if p.Properties.RequestProblemInformation.Value != nil {
+		conn.WantsRespInf = *p.Properties.RequestProblemInformation.Value != 0
+	} else {
+		conn.WantsRespInf = false
+	}
+
+	conn.KeepAliveInterval = time.Duration(p.KeepAliveInterval) * time.Second
+
+	conn.PacketChannel = make(chan packets.ClientPacket)
+
+	go conn.packetReadLoop()
+	return conn
+}

go.mod

@@ -2,4 +2,10 @@ module badat.dev/maeqtt/v2
 
 go 1.16
 
-require github.com/gdexlab/go-render v1.0.1 // indirect
+require (
+	github.com/gdexlab/go-render v1.0.1 // indirect
+	github.com/josharian/impl v1.1.0 // indirect
+	golang.org/x/mod v0.5.0 // indirect
+	golang.org/x/sys v0.0.0-20210915083310-ed5796bab164 // indirect
+	golang.org/x/tools v0.1.5 // indirect
+)

go.sum

@@ -1,2 +1,39 @@
 github.com/gdexlab/go-render v1.0.1 h1:rxqB3vo5s4n1kF0ySmoNeSPRYkEsyHgln4jFIQY7v0U=
 github.com/gdexlab/go-render v1.0.1/go.mod h1:wRi5nW2qfjiGj4mPukH4UV0IknS1cHD4VgFTmJX5JzM=
+github.com/josharian/impl v1.1.0 h1:gafhg1OFVMq46ifdkBa8wp4hlGogjktjjA5h/2j4+2k=
+github.com/josharian/impl v1.1.0/go.mod h1:SQ6aJMP6xsJpGSD/36IIqrUdigLCYe9bz/9o5AKm6Aw=
+github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/mod v0.5.0 h1:UG21uOlmZabA4fW5i7ZX6bjw1xELEGg/ZLgZq9auk/Q=
+golang.org/x/mod v0.5.0/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20210915083310-ed5796bab164 h1:7ZDGnxgHAMw7thfC5bEos0RDAccZKxioiWBhfIe+tvw=
+golang.org/x/sys v0.0.0-20210915083310-ed5796bab164/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20200522201501-cb1345f3a375/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
+golang.org/x/tools v0.1.5 h1:ouewzE6p+/VEB31YYnTbEJdi8pFqKp4P4n85vwo3DHA=
+golang.org/x/tools v0.1.5/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

main.go

@@ -4,10 +4,9 @@ import (
 	"bufio"
 	"log"
 	"net"
+	"runtime/debug"
 
 	"badat.dev/maeqtt/v2/mqtt/packets"
-	"badat.dev/maeqtt/v2/mqtt/properties"
-	"github.com/gdexlab/go-render/render" // For testing
 )
 
 func main() {
@@ -28,37 +27,31 @@ func main() {
 }
 
 func handleConnection(con net.Conn) {
-	defer closeConnection(con)
+	defer handlePanic()
 
-	for {
 	reader := bufio.NewReader(con)
+
 	packet, err := packets.ReadPacket(reader)
 	if err != nil {
 		log.Println("Error reading packet ", err)
-			break
+		return
-		}
-		log.Println(render.AsCode(packet))
-		clientId := "aa"
-		resp := packets.ConnackPacket{
-			ResonCode:      packets.ConnectReasonCodeSuccess,
-			SessionPresent: false,
-			Properties: properties.ConnackPacketProperties{
-				AssignedClientIdentifier: properties.AssignedClientIdentifier{Value: &clientId},
-			},
-		}
-		err = resp.Write(con)
-		log.Println("Wrote response")
-		if err != nil {
-			log.Println("Error writing response ", err)
-			break
 	}
+	connect, isConn := (*packet).(packets.ConnectPacket)
+	if !isConn {
+		log.Println("Didn't recieve a connet packet")
+		panic("TODO: Send a disconnect packet")
 	}
 
+	conn := NewConnection(connect, con)
+
+	sess := NewSession(&conn, connect)
+	sess.HandlerLoop()
 }
 
-func closeConnection(con net.Conn) {
+func handlePanic() {
-	err := con.Close()
+	if r := recover(); r != nil {
-	if err != nil {
+		log.Println("Recovering from panic:", r)
-		log.Println("Failed to close connection", err)
+		log.Println("Stack Trace:")
+		debug.PrintStack()
 	}
 }

mqtt/packets/Connect.go

@@ -8,8 +8,8 @@ import (
 )
 
 type Will struct {
-	retain     bool
+	Retain     bool
-	properties properties.WillProperties
+	Properties properties.WillProperties
 }
 
 type ConnectPacket struct {
@@ -23,8 +23,8 @@ type ConnectPacket struct {
 	Properties properties.ConnectPacketProperties
 }
 
-func (c ConnectPacket) visit(visitor PacketVisitor) {
+func (c ConnectPacket) Visit(Visitor PacketVisitor) {
-	visitor.visitConnect(c)
+	Visitor.VisitConnect(c)
 }
 
 func parseConnectPacket(control controlPacket) (ConnectPacket, error) {
@@ -95,11 +95,11 @@ func parseConnectPacket(control controlPacket) (ConnectPacket, error) {
 
 	if willFlag {
 		packet.Will = &Will{}
-		err = properties.ParseProperties(r, packet.Will.properties.ArrayOf())
+		err = properties.ParseProperties(r, packet.Will.Properties.ArrayOf())
 		if err != nil {
 			return packet, err
 		}
-		packet.Will.retain = willRetainFlag
+		packet.Will.Retain = willRetainFlag
 	}
 
 	var username string

mqtt/packets/Disconnect.go

@@ -99,6 +99,6 @@ func (p DisconnectPacket) Write(w io.Writer) error {
 	return control.write(w)
 }
 
-func (p DisconnectPacket) visit(v PacketVisitor) {
+func (p DisconnectPacket) Visit(v PacketVisitor) {
-	v.visitDisconnect(p)
+	v.VisitDisconnect(p)
 }

mqtt/packets/Ping.go

@@ -9,7 +9,7 @@ import (
 
 type PingreqPacket struct {}
 
-func ParesPingreq(control controlPacket) (PingreqPacket, error) {
+func parsePingreq(control controlPacket) (PingreqPacket, error) {
 	packet := PingreqPacket{}
 
 	if control.packetType != PacketTypePingreq {
@@ -22,6 +22,10 @@ func ParesPingreq(control controlPacket) (PingreqPacket, error) {
 	return packet, nil
 }
 
+func (r PingreqPacket) Visit(p PacketVisitor) {
+	p.VisitPing(r)
+}
+
 type PingrespPacket struct {}
 
 func (p PingrespPacket) Write(w io.Writer) error {

mqtt/packets/Publish.go

@@ -19,8 +19,8 @@ type PublishPacket struct {
 	Properties properties.PublishPacketProperties
 }
 
-func (p PublishPacket) visit(v PacketVisitor) {
+func (p PublishPacket) Visit(v PacketVisitor) {
-	v.visitPublish(p)
+	v.VisitPublish(p)
 }
 
 func parsePublishPacket(control controlPacket) (PublishPacket, error) {

mqtt/packets/Subscriptions.go

@@ -4,13 +4,32 @@ import (
 	"bufio"
 	"errors"
 	"io"
+	"strings"
 
 	"badat.dev/maeqtt/v2/mqtt/properties"
 	"badat.dev/maeqtt/v2/mqtt/types"
 )
 
+type Topic struct {
+	Fields []string
+}
+
+var multiLevelWildcardNotLast = errors.New("Multi level wildcard isn't the field in a topic")
+func parseTopic(topic_name string) (Topic, error) {
+	topic := Topic{}
+	fields := strings.Split(topic_name, "/")
+	for i, field := range fields {
+		if field == "#" && len(fields) > i+1 {
+			return topic, multiLevelWildcardNotLast
+		}
+	}
+	topic.Fields = fields
+
+	return topic, nil
+}
+
 type TopicFilter struct {
-	Topic             string
+	Topic             Topic
 	MaxQoS            uint
 	NoLocal           bool
 	RetainAsPublished bool
@@ -21,7 +40,12 @@ func parseTopicFilter(r *bufio.Reader) (TopicFilter, error) {
 	filter := TopicFilter{}
 	var err error
 
-	filter.Topic, err = types.DecodeUTF8String(r)
+	topic_str, err := types.DecodeUTF8String(r)
+	if err != nil {
+		return filter, err
+	}
+
+	filter.Topic, err = parseTopic(topic_str)
 	if err != nil {
 		return filter, err
 	}
@@ -69,10 +93,14 @@ func parseSubscriptionPacket(control controlPacket, props []properties.Property)
 			return packet, err
 		}
 		_, err = r.Peek(1)
-		if err != nil || err != io.EOF {
+		if err != nil && err != io.EOF {
 			return packet, err
 		}
+		if err == io.EOF {
+			return packet, nil
 		}
+	}
+	println("A")
 
 	return packet, nil
 }
@@ -82,6 +110,9 @@ type SubscribePacket struct {
 	props properties.SubscribePacketProperties
 }
 
+/// CURRENTLY BROKEN
+
+// TODO FIXME AAAAA
 func parseSubscribePacket(control controlPacket) (SubscribePacket, error) {
 	if control.packetType != PacketTypeSubscribe {
 		panic("Wrong packet type for parseSubscribePacket")
@@ -92,11 +123,14 @@ func parseSubscribePacket(control controlPacket) (SubscribePacket, error) {
 	if err != nil {
 		return pack, err
 	}
-	pack.PacketId = subscriptionPack.PacketId
+	pack.SubscriptionPacket = &subscriptionPack
-	pack.TopicFilters = subscriptionPack.TopicFilters
 	return pack, nil
 }
 
+func (p SubscribePacket) Visit(v PacketVisitor) {
+	v.VisitSubscribe(p)
+}
+
 type SubackReasonCode byte
 
 const (
@@ -151,6 +185,10 @@ func parseUnsubscribePacket(control controlPacket) (UnsubscribePacket, error) {
 	return pack, nil
 }
 
+func (p UnsubscribePacket) Visit(v PacketVisitor) {
+	v.VisitUnsubscribe(p)
+}
+
 type UnsubackReasonCode byte
 
 const (

mqtt/packets/packets.go

@@ -2,7 +2,6 @@ package packets
 
 import (
 	"bufio"
-	"bytes"
 	"fmt"
 	"io"
 
@@ -10,17 +9,24 @@ import (
 )
 
 type PacketVisitor interface {
-	visitConnect(ConnectPacket)
+	VisitConnect(ConnectPacket)
-	visitPublish(PublishPacket)
+	VisitPublish(PublishPacket)
-	visitDisconnect(DisconnectPacket)
+	VisitDisconnect(DisconnectPacket)
+	VisitSubscribe(SubscribePacket)
+	VisitUnsubscribe(UnsubscribePacket)
+	VisitPing(PingreqPacket)
+	VisitPubackPacket(PubackPacket)
+	VisitPubrecPacket(PubrecPacket)
+	VisitPubrelPacket(PubrelPacket)
+	VisitPubcompPacket(PubcompPacket)
 }
 
 type ClientPacket interface {
-	visit(PacketVisitor)
+	Visit(PacketVisitor)
 }
 
 type ServerPacket interface {
-	Encode() (bytes.Buffer, error)
+	Write(w io.Writer) error
 }
 
 type PacketType byte
@@ -45,12 +51,10 @@ const (
 )
 
 func ReadPacket(r *bufio.Reader) (*ClientPacket, error) {
-	println("AAAA")
 	fixedHeader, err := r.ReadByte()
 	if err != nil {
 		return nil, err
 	}
-	println("BBB")
 
 	highestFourBits := uint((fixedHeader >> 4) & 0b1111)
 	lowerFourBits := uint(fixedHeader & 0b1111)
@@ -60,6 +64,7 @@ func ReadPacket(r *bufio.Reader) (*ClientPacket, error) {
 		return nil, err
 	}
 	reader := io.LimitReader(r, int64(dataLength))
+	
 	control := controlPacket{
 		packetType: PacketType(highestFourBits),
 		flags:      lowerFourBits,
@@ -74,6 +79,20 @@ func ReadPacket(r *bufio.Reader) (*ClientPacket, error) {
 		packet, err = parsePublishPacket(control)
 	case PacketTypeDisconnect:
 		packet, err = parseDisconnectPacket(control)
+	case PacketTypeSubscribe:
+		packet, err = parseSubscribePacket(control)
+	case PacketTypeUnsubscribe:
+		packet, err = parseUnsubscribePacket(control)
+	case PacketTypePingreq:
+		packet, err = parsePingreq(control)
+	case PacketTypePuback:
+		panic("Puback packet parsing unimplemented")
+	case PacketTypePubrec:
+		panic("Pubrec packet parsing unimplemented")
+	case PacketTypePubrel:
+		panic("Pubrel packet parsing unimplemented")
+	case PacketTypePubcomp:
+		panic("Pubcomp packet parsing unimplemented")
 	default:
 		return nil, fmt.Errorf("Unknown packet type %v", control.packetType)
 	}

session.go

@@ -0,0 +1,181 @@
+package main
+
+import (
+	"encoding/base64"
+	"fmt"
+	"log"
+	"math/rand"
+	"time"
+
+	"badat.dev/maeqtt/v2/mqtt/packets"
+)
+
+func init() {
+	rand.Seed(time.Now().UnixNano())
+}
+
+func Auth(username string, password []byte) bool {
+	return true
+}
+
+type Session struct {
+	ClientID *string
+
+	// Nullable
+	Connection          *Connection
+	SubscriptionChannel chan packets.PublishPacket
+
+	ExpiryInterval time.Duration
+	expireTimer    time.Timer // TODO
+}
+
+func NewSession(conn *Connection, p packets.ConnectPacket) Session {
+	sess := Session{}
+	sess.SubscriptionChannel = make(chan packets.PublishPacket)
+
+	sess.Connect(conn, p)
+	return sess
+}
+
+func (s *Session) Connect(conn *Connection, p packets.ConnectPacket) {
+	if s.Connection != nil {
+		//TODO
+		panic("Disconnect if already have a connection, unimplemented")
+	}
+	connAck := packets.ConnackPacket{}
+
+	s.updateExpireTimer(p.Properties.SessionExpiryInterval.Value)
+
+	if p.ClientId != nil {
+		if s.ClientID == nil {
+			s.ClientID = genClientID()
+		}
+		connAck.Properties.AssignedClientIdentifier.Value = s.ClientID
+	}
+
+	true := byte(1)
+	false := byte(0)
+	connAck.Properties.WildcardSubscriptionAvailable.Value = &true
+
+	connAck.Properties.RetainAvailable.Value = &false
+	connAck.Properties.SharedSubscriptionAvailable.Value = &false
+
+
+	s.Connection = conn
+	err := s.Connection.sendPacket(connAck)
+	if err != nil {
+		panic(err)
+	}
+}
+
+// Starts a loop the recieves and responds to packets
+func (s *Session) HandlerLoop() {
+	for s.Connection != nil {
+		select {
+		case packet := <-s.Connection.PacketChannel:
+			packet.Visit(s)
+		case _ = <-s.Connection.ClientDisconnectedChan:
+			s.OnDisconnect()
+		case subMessage := <-s.SubscriptionChannel:
+			//TODO, log for now
+			log.Printf("Recieved subscription message, handling UNIMPLEMENTED, message: %v", subMessage)
+		}
+	}
+}
+
+func (s *Session) Disconnect() error {
+	panic("Disconnection unimplemented")
+	err := s.Connection.close()
+	if err != nil {
+		return err
+	}
+	s.OnDisconnect()
+	return nil
+}
+
+func (s *Session) OnDisconnect() {
+	s.Connection = nil
+	s.resetExpireTimer()
+	log.Printf("Client disconnected, id: %s", *s.ClientID)
+}
+
+// newTime is nullable
+func (s *Session) updateExpireTimer(newTime *uint32) {
+	var expiry = uint32(0)
+	if newTime != nil {
+		expiry = *newTime
+	} else {
+		expiry = uint32(0)
+	}
+	s.ExpiryInterval = time.Duration(expiry) * time.Second
+
+	if s.Connection == nil {
+		s.resetExpireTimer()
+	}
+}
+func (s *Session) resetExpireTimer() {
+	//s.expireTimer.Reset(s.ExpiryInterval)
+}
+
+func genClientID() *string {
+	buf := make([]byte, 32)
+	_, err := rand.Read(buf)
+	if err != nil {
+		// I don't think this can actually happen but just in case panic
+		panic(fmt.Errorf("Failed to generate a client id, %e", err))
+	}
+	id := "Client_rand_" + base64.URLEncoding.WithPadding(base64.NoPadding).EncodeToString(buf)
+	return &id
+}
+
+func (s *Session) VisitConnect(_ packets.ConnectPacket) {
+	// ERROR CANNOT RECIEVE CONNECT ON AN ALREADY OPEN CONNECTION
+	s.Disconnect()
+}
+
+func (s *Session) VisitPublish(p packets.PublishPacket) {
+	println("UNIMPLEMENTED, Publishing packet, message:", string(p.Payload))
+	subs, lock := Subscriptions.GetSubscriptions(p.TopicName) 
+	defer lock.Unlock()
+
+	for _, sub := range subs {
+		go func(sub Subscription) {sub <- p}(sub)
+	}
+}
+
+func (s *Session) VisitDisconnect(p packets.DisconnectPacket) {
+	//TODO FINISH
+	// HANDLE CLIENT DISCONNECTING
+	s.OnDisconnect()
+}
+
+func (s *Session) VisitSubscribe(p packets.SubscribePacket) {
+	//TODO FINISH
+	for _, filter := range p.TopicFilters {
+		Subscriptions.Subscribe(filter.Topic, s.SubscriptionChannel)		
+	}
+}
+
+func (s *Session) VisitUnsubscribe(_ packets.UnsubscribePacket) {
+	panic("not implemented") // TODO: Implement
+}
+
+func (s *Session) VisitPing(p packets.PingreqPacket) {
+	s.Connection.sendPacket(packets.PingrespPacket{})
+}
+
+func (s *Session) VisitPubackPacket(_ packets.PubackPacket) {
+	panic("not implemented") // TODO: Implement
+}
+
+func (s *Session) VisitPubrecPacket(_ packets.PubrecPacket) {
+	panic("not implemented") // TODO: Implement
+}
+
+func (s *Session) VisitPubrelPacket(_ packets.PubrelPacket) {
+	panic("not implemented") // TODO: Implement
+}
+
+func (s *Session) VisitPubcompPacket(_ packets.PubcompPacket) {
+	panic("not implemented") // TODO: Implement
+}

subscription.go

@@ -0,0 +1,86 @@
+package main
+
+//TODO FULLY IMPLEMENT SUBSCRIPTIONS INSTEAD OF JUST THE TOPIC FILTERS
+
+import (
+	"strings"
+	"sync"
+
+	"badat.dev/maeqtt/v2/mqtt/packets"
+)
+
+var Subscriptions SubscriptionTreeNode = *NewSubscriptionTreeNode()
+
+type Subscription chan packets.PublishPacket
+
+type SubscriptionTreeNode struct {
+	subscriptions []Subscription
+	children      map[string]*SubscriptionTreeNode
+	nodeLock      sync.RWMutex
+}
+func NewSubscriptionTreeNode() *SubscriptionTreeNode {
+	s := SubscriptionTreeNode{}
+	s.children = make(map[string]*SubscriptionTreeNode)
+	return &s
+}
+
+func (s *SubscriptionTreeNode) findNode(fields []string) *SubscriptionTreeNode {
+	if len(fields) == 0 {
+		return s
+	}
+
+	field := fields[0]
+
+	s.nodeLock.RLock()
+	_, exists := s.children[field]
+	// Insert a value into the map if one doesn't exist yet
+	if !exists {
+		// Can't upgrade a read lock so we need to unlock and
+		// check again, this time with a write lock
+		s.nodeLock.RUnlock()
+		s.nodeLock.Lock()
+
+		_, exists = s.children[field]
+		if !exists {
+			s.children[field] = NewSubscriptionTreeNode()
+		}
+		s.nodeLock.Unlock()
+		s.nodeLock.RLock()
+	}
+
+	child, _ := s.children[field]
+	s.nodeLock.RUnlock()
+	return child.findNode(fields[1:])
+}
+
+func (s *SubscriptionTreeNode) Subscribe(topic packets.Topic, sub Subscription) {
+	node := s.findNode(topic.Fields)
+	node.nodeLock.Lock()
+	node.subscriptions = append(node.subscriptions, sub)
+	node.nodeLock.Unlock()
+}
+
+func (s *SubscriptionTreeNode) GetSubscriptions(topic string) ([]Subscription, sync.Locker) {
+	fields := strings.Split(topic,"/")
+
+	child := s.findNode(fields)
+	locker := child.nodeLock.RLocker()
+	locker.Lock()
+	return child.subscriptions, locker
+}
+
+func (s *SubscriptionTreeNode) findMatchingRec(topic []string) ([]Subscription, sync.Locker) {
+	locker := s.nodeLock.RLocker()
+	s.nodeLock.RLock()
+	if len(topic) == 0 {
+		return s.subscriptions,locker
+	}
+	defer s.nodeLock.RUnlock()
+
+	child, exists := s.children[topic[0]]
+	if exists {
+		return child.findMatchingRec(topic[1:])
+	} else {
+		return []Subscription{},locker
+	}
+}