Update server version

Add the OnUnsubscribed hook to the unsubscribeClient method，and change the unsubscribeClient to externally visible. In a clustered environment, if a client is disconnected and then connected to another node, the subscriptions on the previous node need to be cleared.

README.md

@@ -305,13 +305,22 @@ The function signatures for all the hooks and `mqtt.Hook` interface can be found
 
 If you are building a persistent storage hook, see the existing persistent hooks for inspiration and patterns. If you are building an auth hook, you will need `OnACLCheck` and `OnConnectAuthenticate`.
 
-### Packet Injection
-It's also possible to inject custom MQTT packets directly into the runtime as though they had been received by a specific client. This special client is called an InlineClient, and it has unique privileges: it bypasses all ACL and topic validation checks, meaning it can even publish to $SYS topics. 
 
-Packet injection can be used with MQTT packet, including ping requests, subscriptions, etc. And because the Clients structs and methods are now exported, you can even inject packets on behalf of a connected client (if you have a very custom requirement).
+### Direct Publish
+To publish basic message to a topic from within the embedding application, you can use the `server.Publish(topic string, payload []byte, retain bool, qos byte) error` method.
 
 ```go
-cl := mqtt.NewInlineClient("inline", "local")
+err := server.Publish("direct/publish", []byte("packet scheduled message"), false, 0)
+```
+> The Qos byte in this case is only used to set the upper qos limit available for subscribers, as per MQTT v5 spec.
+
+### Packet Injection
+If you want more control, or want to set specific MQTT v5 properties and other values you can create your own publish packets from a client of your choice. This method allows you to inject MQTT packets (no just publish) directly into the runtime as though they had been received by a specific client. Most of the time you'll want to use the special client flag `inline=true`, as it has unique privileges: it bypasses all ACL and topic validation checks, meaning it can even publish to $SYS topics. 
+
+Packet injection can be used for any MQTT packet, including ping requests, subscriptions, etc. And because the Clients structs and methods are now exported, you can even inject packets on behalf of a connected client (if you have a very custom requirements).
+
+```go
+cl := server.NewClient(nil, "local", "inline", true)
 server.InjectPacket(cl, packets.Packet{
   FixedHeader: packets.FixedHeader{
     Type: packets.Publish,

clients.go

@@ -146,14 +146,10 @@ type ClientState struct {
 	keepalive     uint16         // the number of seconds the connection can wait
 }
 
-// NewClient returns a new instance of Client.
-func NewClient(c net.Conn, o *ops) *Client {
+// newClient returns a new instance of Client. This is almost exclusively used by Server
+// for creating new clients, but it lives here because it's not dependent.
+func newClient(c net.Conn, o *ops) *Client {
 	cl := &Client{
-		Net: ClientConnection{
-			conn:   c,
-			bconn:  bufio.NewReadWriter(bufio.NewReader(c), bufio.NewWriter(c)),
-			Remote: c.RemoteAddr().String(),
-		},
 		State: ClientState{
 			Inflight:      NewInflights(),
 			Subscriptions: NewSubscriptions(),
@@ -166,46 +162,19 @@ func NewClient(c net.Conn, o *ops) *Client {
 		ops: o,
 	}
 
+	if c != nil {
+		cl.Net = ClientConnection{
+			conn:   c,
+			bconn:  bufio.NewReadWriter(bufio.NewReader(c), bufio.NewWriter(c)),
+			Remote: c.RemoteAddr().String(),
+		}
+	}
+
 	cl.refreshDeadline(cl.State.keepalive)
 
 	return cl
 }
 
-// NewInlineClient returns a client used when publishing from the embedding system.
-func NewInlineClient(id, remote string) *Client {
-	return &Client{
-		ID: id,
-		Net: ClientConnection{
-			Remote: remote,
-			Inline: true,
-		},
-		State: ClientState{
-			Inflight:      NewInflights(),
-			Subscriptions: NewSubscriptions(),
-			TopicAliases:  NewTopicAliases(0),
-		},
-		Properties: ClientProperties{
-			ProtocolVersion: defaultClientProtocolVersion, // default protocol version
-		},
-	}
-}
-
-// newClientStub returns an instance of Client with minimal initializations, such as
-// restoring client data from a db. In particular, the client is marked as offline (done).
-func newClientStub() *Client {
-	return &Client{
-		State: ClientState{
-			Inflight:      NewInflights(),
-			Subscriptions: NewSubscriptions(),
-			TopicAliases:  NewTopicAliases(0),
-			done:          1,
-		},
-		Properties: ClientProperties{
-			ProtocolVersion: defaultClientProtocolVersion, // default protocol version
-		},
-	}
-}
-
 // ParseConnect parses the connect parameters and properties for a client.
 func (cl *Client) ParseConnect(lid string, pk packets.Packet) {
 	cl.Net.Listener = lid
@@ -414,6 +383,10 @@ func (cl *Client) ReadFixedHeader(fh *packets.FixedHeader) error {
 		return err
 	}
 
+	if cl.ops.capabilities.MaximumPacketSize > 0 && uint32(fh.Remaining+1) > cl.ops.capabilities.MaximumPacketSize {
+		return packets.ErrPacketTooLarge // [MQTT-3.2.2-15]
+	}
+
 	atomic.AddInt64(&cl.ops.info.BytesReceived, int64(bu+1))
 	return nil
 }

clients_test.go

@@ -22,10 +22,10 @@ const pkInfo = "packet type %v, %s"
 
 var errClientStop = errors.New("test stop")
 
-func newClient() (cl *Client, r net.Conn, w net.Conn) {
+func newTestClient() (cl *Client, r net.Conn, w net.Conn) {
 	r, w = net.Pipe()
 
-	cl = NewClient(w, &ops{
+	cl = newClient(w, &ops{
 		info:  new(system.Info),
 		hooks: new(Hooks),
 		log:   &logger,
@@ -119,34 +119,21 @@ func TestClientsGetByListener(t *testing.T) {
 }
 
 func TestNewClient(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 
 	require.NotNil(t, cl)
 	require.NotNil(t, cl.State.Inflight.internal)
 	require.NotNil(t, cl.State.Subscriptions)
-	require.Nil(t, cl.StopCause())
-}
-
-func TestNewClientStub(t *testing.T) {
-	cl := newClientStub()
-	require.NotNil(t, cl)
-	require.NotNil(t, cl.State.Inflight.internal)
-	require.NotNil(t, cl.State.Subscriptions)
-	require.Equal(t, uint32(1), atomic.LoadUint32(&cl.State.done))
-}
-
-func TestNewInlineClient(t *testing.T) {
-	cl := NewInlineClient("inline", "local")
-	require.NotNil(t, cl)
-	require.NotNil(t, cl.State.Inflight.internal)
-	require.NotNil(t, cl.State.Subscriptions)
-	require.Equal(t, uint32(0), atomic.LoadUint32(&cl.State.done))
-	require.Equal(t, "inline", cl.ID)
-	require.Equal(t, "local", cl.Net.Remote)
+	require.NotNil(t, cl.State.TopicAliases)
+	require.Equal(t, defaultKeepalive, cl.State.keepalive)
+	require.Equal(t, defaultClientProtocolVersion, cl.Properties.ProtocolVersion)
+	require.NotNil(t, cl.Net.conn)
+	require.NotNil(t, cl.Net.bconn)
+	require.False(t, cl.Net.Inline)
 }
 
 func TestClientParseConnect(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 
 	pk := packets.Packet{
 		ProtocolVersion: 4,
@@ -183,7 +170,7 @@ func TestClientParseConnect(t *testing.T) {
 }
 
 func TestClientParseConnectOverrideWillDelay(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 
 	pk := packets.Packet{
 		ProtocolVersion: 4,
@@ -208,13 +195,13 @@ func TestClientParseConnectOverrideWillDelay(t *testing.T) {
 }
 
 func TestClientParseConnectNoID(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.ParseConnect("tcp1", packets.Packet{})
 	require.NotEmpty(t, cl.ID)
 }
 
 func TestClientNextPacketID(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 
 	i, err := cl.NextPacketID()
 	require.NoError(t, err)
@@ -226,7 +213,7 @@ func TestClientNextPacketID(t *testing.T) {
 }
 
 func TestClientNextPacketIDInUse(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 
 	// skip over 2
 	cl.State.Inflight.Set(packets.Packet{PacketID: 2})
@@ -249,7 +236,7 @@ func TestClientNextPacketIDInUse(t *testing.T) {
 }
 
 func TestClientNextPacketIDExhausted(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	for i := 0; i <= 65535; i++ {
 		cl.State.Inflight.Set(packets.Packet{PacketID: uint16(i)})
 	}
@@ -261,7 +248,7 @@ func TestClientNextPacketIDExhausted(t *testing.T) {
 }
 
 func TestClientNextPacketIDOverflow(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 
 	cl.State.packetID = uint32(65534)
 
@@ -275,7 +262,7 @@ func TestClientNextPacketIDOverflow(t *testing.T) {
 }
 
 func TestClientClearInflights(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 
 	n := time.Now().Unix()
 	cl.State.Inflight.Set(packets.Packet{PacketID: 1, Expiry: n - 1})
@@ -291,7 +278,7 @@ func TestClientClearInflights(t *testing.T) {
 
 func TestClientResendInflightMessages(t *testing.T) {
 	pk1 := packets.TPacketData[packets.Puback].Get(packets.TPuback)
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 
 	cl.State.Inflight.Set(*pk1.Packet)
 	require.Equal(t, 1, cl.State.Inflight.Len())
@@ -311,7 +298,7 @@ func TestClientResendInflightMessages(t *testing.T) {
 
 func TestClientResendInflightMessagesWriteFailure(t *testing.T) {
 	pk1 := packets.TPacketData[packets.Publish].Get(packets.TPublishQos1Dup)
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	r.Close()
 
 	cl.State.Inflight.Set(*pk1.Packet)
@@ -323,19 +310,19 @@ func TestClientResendInflightMessagesWriteFailure(t *testing.T) {
 }
 
 func TestClientResendInflightMessagesNoMessages(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	err := cl.ResendInflightMessages(true)
 	require.NoError(t, err)
 }
 
 func TestClientRefreshDeadline(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.refreshDeadline(10)
 	require.NotNil(t, cl.Net.conn) // how do we check net.Conn deadline?
 }
 
 func TestClientReadFixedHeader(t *testing.T) {
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 
 	defer cl.Stop(errClientStop)
 	go func() {
@@ -350,7 +337,7 @@ func TestClientReadFixedHeader(t *testing.T) {
 }
 
 func TestClientReadFixedHeaderDecodeError(t *testing.T) {
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	defer cl.Stop(errClientStop)
 
 	go func() {
@@ -363,8 +350,24 @@ func TestClientReadFixedHeaderDecodeError(t *testing.T) {
 	require.Error(t, err)
 }
 
+func TestClientReadFixedHeaderPacketOversized(t *testing.T) {
+	cl, r, _ := newTestClient()
+	cl.ops.capabilities.MaximumPacketSize = 2
+	defer cl.Stop(errClientStop)
+
+	go func() {
+		r.Write(packets.TPacketData[packets.Publish].Get(packets.TPublishQos1Dup).RawBytes)
+		r.Close()
+	}()
+
+	fh := new(packets.FixedHeader)
+	err := cl.ReadFixedHeader(fh)
+	require.Error(t, err)
+	require.ErrorIs(t, err, packets.ErrPacketTooLarge)
+}
+
 func TestClientReadFixedHeaderReadEOF(t *testing.T) {
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	defer cl.Stop(errClientStop)
 
 	go func() {
@@ -378,7 +381,7 @@ func TestClientReadFixedHeaderReadEOF(t *testing.T) {
 }
 
 func TestClientReadFixedHeaderNoLengthTerminator(t *testing.T) {
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	defer cl.Stop(errClientStop)
 
 	go func() {
@@ -392,7 +395,7 @@ func TestClientReadFixedHeaderNoLengthTerminator(t *testing.T) {
 }
 
 func TestClientReadOK(t *testing.T) {
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	defer cl.Stop(errClientStop)
 	go func() {
 		r.Write([]byte{
@@ -446,7 +449,7 @@ func TestClientReadOK(t *testing.T) {
 }
 
 func TestClientReadDone(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	defer cl.Stop(errClientStop)
 	cl.State.done = 1
 
@@ -461,15 +464,16 @@ func TestClientReadDone(t *testing.T) {
 }
 
 func TestClientStop(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.Stop(nil)
 	require.Equal(t, nil, cl.State.stopCause.Load())
 	require.Equal(t, time.Now().Unix(), cl.State.disconnected)
 	require.Equal(t, uint32(1), cl.State.done)
+	require.Equal(t, nil, cl.StopCause())
 }
 
 func TestClientReadFixedHeaderError(t *testing.T) {
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	defer cl.Stop(errClientStop)
 	go func() {
 		r.Write([]byte{
@@ -486,7 +490,7 @@ func TestClientReadFixedHeaderError(t *testing.T) {
 }
 
 func TestClientReadReadHandlerErr(t *testing.T) {
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	defer cl.Stop(errClientStop)
 	go func() {
 		r.Write([]byte{
@@ -506,7 +510,7 @@ func TestClientReadReadHandlerErr(t *testing.T) {
 }
 
 func TestClientReadReadPacketOK(t *testing.T) {
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	defer cl.Stop(errClientStop)
 	go func() {
 		r.Write([]byte{
@@ -538,7 +542,7 @@ func TestClientReadReadPacketOK(t *testing.T) {
 }
 
 func TestClientReadPacket(t *testing.T) {
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	defer cl.Stop(errClientStop)
 
 	for _, tx := range pkTable {
@@ -571,9 +575,17 @@ func TestClientReadPacket(t *testing.T) {
 	}
 }
 
+func TestClientReadPacketInvalidTypeError(t *testing.T) {
+	cl, _, _ := newTestClient()
+	cl.Net.conn.Close()
+	_, err := cl.ReadPacket(&packets.FixedHeader{})
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "invalid packet type")
+}
+
 func TestClientWritePacket(t *testing.T) {
 	for _, tt := range pkTable {
-		cl, r, _ := newClient()
+		cl, r, _ := newTestClient()
 		defer cl.Stop(errClientStop)
 
 		cl.Properties.ProtocolVersion = tt.Packet.ProtocolVersion
@@ -613,7 +625,7 @@ func TestClientWritePacket(t *testing.T) {
 }
 
 func TestWriteClientOversizePacket(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.Properties.Props.MaximumPacketSize = 2
 	pk := *packets.TPacketData[packets.Publish].Get(packets.TPublishDropOversize).Packet
 	err := cl.WritePacket(pk)
@@ -622,7 +634,7 @@ func TestWriteClientOversizePacket(t *testing.T) {
 }
 
 func TestClientReadPacketReadingError(t *testing.T) {
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	defer cl.Stop(errClientStop)
 	go func() {
 		r.Write([]byte{
@@ -642,7 +654,7 @@ func TestClientReadPacketReadingError(t *testing.T) {
 }
 
 func TestClientReadPacketReadUnknown(t *testing.T) {
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	defer cl.Stop(errClientStop)
 	go func() {
 		r.Write([]byte{
@@ -661,7 +673,7 @@ func TestClientReadPacketReadUnknown(t *testing.T) {
 }
 
 func TestClientWritePacketWriteNoConn(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.Stop(errClientStop)
 
 	err := cl.WritePacket(*pkTable[1].Packet)
@@ -670,7 +682,7 @@ func TestClientWritePacketWriteNoConn(t *testing.T) {
 }
 
 func TestClientWritePacketWriteError(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.Net.conn.Close()
 
 	err := cl.WritePacket(*pkTable[1].Packet)
@@ -678,7 +690,7 @@ func TestClientWritePacketWriteError(t *testing.T) {
 }
 
 func TestClientWritePacketInvalidPacket(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	err := cl.WritePacket(packets.Packet{})
 	require.Error(t, err)
 }

examples/hooks/main.go

@@ -52,15 +52,30 @@ func main() {
 	// `server.Publish` method. Subscribe to `direct/publish` using your
 	// MQTT client to see the messages.
 	go func() {
-		cl := mqtt.NewInlineClient("inline", "local")
-		for range time.Tick(time.Second * 10) {
-			server.InjectPacket(cl, packets.Packet{
+		cl := server.NewClient(nil, "local", "inline", true)
+		for range time.Tick(time.Second * 1) {
+			err := server.InjectPacket(cl, packets.Packet{
 				FixedHeader: packets.FixedHeader{
 					Type: packets.Publish,
 				},
 				TopicName: "direct/publish",
-				Payload:   []byte("scheduled message"),
+				Payload:   []byte("injected scheduled message"),
 			})
+			if err != nil {
+				server.Log.Error().Err(err).Msg("server.InjectPacket")
+			}
+			server.Log.Info().Msgf("main.go injected packet to direct/publish")
+		}
+	}()
+
+	// There is also a shorthand convenience function, Publish, for easily sending
+	// publish packets if you are not concerned with creating your own packets.
+	go func() {
+		for range time.Tick(time.Second * 5) {
+			err := server.Publish("direct/publish", []byte("packet scheduled message"), false, 0)
+			if err != nil {
+				server.Log.Error().Err(err).Msg("server.Publish")
+			}
 			server.Log.Info().Msgf("main.go issued direct message to direct/publish")
 		}
 	}()

hooks.go

@@ -351,7 +351,7 @@ func (h *Hooks) OnUnsubscribed(cl *Client, pk packets.Packet) {
 	}
 }
 
-// OnPublish is called when a client publishes a message. This method differs from OnMessage
+// OnPublish is called when a client publishes a message. This method differs from OnPublished
 // in that it allows you to modify you to modify the incoming packet before it is processed.
 // The return values of the hook methods are passed-through in the order the hooks were attached.
 func (h *Hooks) OnPublish(cl *Client, pk packets.Packet) (pkx packets.Packet, err error) {

inflight_test.go

@@ -13,7 +13,7 @@ import (
 )
 
 func TestInflightSet(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 
 	r := cl.State.Inflight.Set(packets.Packet{PacketID: 1})
 	require.True(t, r)
@@ -25,7 +25,7 @@ func TestInflightSet(t *testing.T) {
 }
 
 func TestInflightGet(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.State.Inflight.Set(packets.Packet{PacketID: 2})
 
 	msg, ok := cl.State.Inflight.Get(2)
@@ -34,7 +34,7 @@ func TestInflightGet(t *testing.T) {
 }
 
 func TestInflightGetAllAndImmediate(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.State.Inflight.Set(packets.Packet{PacketID: 1, Created: 1})
 	cl.State.Inflight.Set(packets.Packet{PacketID: 2, Created: 2})
 	cl.State.Inflight.Set(packets.Packet{PacketID: 3, Created: 3, Expiry: -1})
@@ -56,13 +56,13 @@ func TestInflightGetAllAndImmediate(t *testing.T) {
 }
 
 func TestInflightLen(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.State.Inflight.Set(packets.Packet{PacketID: 2})
 	require.Equal(t, 1, cl.State.Inflight.Len())
 }
 
 func TestInflightDelete(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 
 	cl.State.Inflight.Set(packets.Packet{PacketID: 3})
 	require.NotNil(t, cl.State.Inflight.internal[3])
@@ -163,7 +163,7 @@ func TestSendQuota(t *testing.T) {
 }
 
 func TestNextImmediate(t *testing.T) {
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.State.Inflight.Set(packets.Packet{PacketID: 1, Created: 1})
 	cl.State.Inflight.Set(packets.Packet{PacketID: 2, Created: 2})
 	cl.State.Inflight.Set(packets.Packet{PacketID: 3, Created: 3, Expiry: -1})

listeners/websocket.go

@@ -7,6 +7,7 @@ package listeners
 import (
 	"context"
 	"errors"
+	"io"
 	"net"
 	"net/http"
 	"sync"
@@ -137,25 +138,35 @@ type wsConn struct {
 }
 
 // Read reads the next span of bytes from the websocket connection and returns the number of bytes read.
-func (ws *wsConn) Read(p []byte) (n int, err error) {
+func (ws *wsConn) Read(p []byte) (int, error) {
 	op, r, err := ws.c.NextReader()
 	if err != nil {
-		return
+		return 0, err
 	}
 
 	if op != websocket.BinaryMessage {
 		err = ErrInvalidMessage
-		return
+		return 0, err
 	}
 
-	return r.Read(p)
+	var n, br int
+	for {
+		br, err = r.Read(p[n:])
+		n += br
+		if err != nil {
+			if err == io.EOF {
+				err = nil
+			}
+			return n, err
+		}
+	}
 }
 
 // Write writes bytes to the websocket connection.
-func (ws *wsConn) Write(p []byte) (n int, err error) {
-	err = ws.c.WriteMessage(websocket.BinaryMessage, p)
+func (ws *wsConn) Write(p []byte) (int, error) {
+	err := ws.c.WriteMessage(websocket.BinaryMessage, p)
 	if err != nil {
-		return
+		return 0, err
 	}
 
 	return len(p), nil

server.go

@@ -26,10 +26,10 @@ import (
 )
 
 const (
-	Version                        = "2.0.0"  // the current server version.
-	defaultSysTopicInterval int64  = 1        // the interval between $SYS topic publishes
-	defaultFanPoolSize      uint64 = 64       // the number of concurrent workers in the pool
-	defaultFanPoolQueueSize uint64 = 32 * 128 // the capacity of each worker queue
+	Version                        = "2.0.7" // the current server version.
+	defaultSysTopicInterval int64  = 1       // the interval between $SYS topic publishes
+	defaultFanPoolSize      uint64 = 32      // the number of concurrent workers in the pool
+	defaultFanPoolQueueSize uint64 = 1024    // the capacity of each worker queue
 )
 
 var (
@@ -199,6 +199,31 @@ func (o *Options) ensureDefaults() {
 	}
 }
 
+// NewClient returns a new Client instance, populated with all the required values and
+// references to be used with the server. If you are using this client to directly publish
+// messages from the embedding application, set the inline flag to true to bypass ACL and
+// topic validation checks.
+func (s *Server) NewClient(c net.Conn, listener string, id string, inline bool) *Client {
+	cl := newClient(c, &ops{ // [MQTT-3.1.2-6] implicit
+		capabilities: s.Options.Capabilities,
+		info:         s.Info,
+		hooks:        s.hooks,
+		log:          s.Log,
+	})
+
+	cl.ID = id
+	cl.Net.Listener = listener
+
+	if inline { // inline clients bypass acl and some validity checks.
+		cl.Net.Inline = true
+		// By default we don't want to restrict developer publishes,
+		// but if you do, reset this after creating inline client.
+		cl.State.Inflight.ResetReceiveQuota(math.MaxInt32)
+	}
+
+	return cl
+}
+
 // AddHook attaches a new Hook to the server. Ideally, this should be called
 // before the server is started with s.Serve().
 func (s *Server) AddHook(hook Hook, config any) error {
@@ -281,27 +306,21 @@ func (s *Server) eventLoop() {
 }
 
 // EstablishConnection establishes a new client when a listener accepts a new connection.
-func (s *Server) EstablishConnection(lid string, c net.Conn) error {
-	cl := NewClient(c, &ops{ // [MQTT-3.1.2-6] implicit
-		capabilities: s.Options.Capabilities,
-		info:         s.Info,
-		hooks:        s.hooks,
-		log:          s.Log,
-	})
-
-	return s.attachClient(cl, lid)
+func (s *Server) EstablishConnection(listener string, c net.Conn) error {
+	cl := s.NewClient(c, listener, "", false)
+	return s.attachClient(cl, listener)
 }
 
 // attachClient validates an incoming client connection and if viable, attaches the client
 // to the server, performs session housekeeping, and reads incoming packets.
-func (s *Server) attachClient(cl *Client, lid string) error {
+func (s *Server) attachClient(cl *Client, listener string) error {
 	defer cl.Stop(nil)
 	pk, err := s.readConnectionPacket(cl)
 	if err != nil {
 		return fmt.Errorf("read connection: %w", err)
 	}
 
-	cl.ParseConnect(lid, pk)
+	cl.ParseConnect(listener, pk)
 	code := s.validateConnect(cl, pk) // [MQTT-3.1.4-1] [MQTT-3.1.4-2]
 	if code != packets.CodeSuccess {
 		if err := s.sendConnack(cl, code, false); err != nil {
@@ -353,11 +372,11 @@ func (s *Server) attachClient(cl *Client, lid string) error {
 		cl.Properties.Will = Will{} // [MQTT-3.14.4-3] [MQTT-3.1.2-10]
 	}
 
-	s.Log.Debug().Str("client", cl.ID).Err(err).Str("remote", cl.Net.Remote).Str("listener", lid).Msg("client disconnected")
+	s.Log.Debug().Str("client", cl.ID).Err(err).Str("remote", cl.Net.Remote).Str("listener", listener).Msg("client disconnected")
 	expire := (cl.Properties.ProtocolVersion == 5 && cl.Properties.Props.SessionExpiryIntervalFlag && cl.Properties.Props.SessionExpiryInterval == 0) || (cl.Properties.ProtocolVersion < 5 && cl.Properties.Clean)
 	s.hooks.OnDisconnect(cl, err, expire)
 	if expire {
-		s.unsubscribeClient(cl)
+		s.UnsubscribeClient(cl)
 		cl.ClearInflights(math.MaxInt64, 0)
 		s.Clients.Delete(cl.ID) // [MQTT-4.1.0-2] ![MQTT-3.1.2-23]
 	}
@@ -436,7 +455,7 @@ func (s *Server) inheritClientSession(pk packets.Packet, cl *Client) bool {
 		defer existing.Unlock()
 		s.DisconnectClient(existing, packets.ErrSessionTakenOver)                                 // [MQTT-3.1.4-3]
 		if pk.Connect.Clean || (existing.Properties.Clean && cl.Properties.ProtocolVersion < 5) { // [MQTT-3.1.2-4] [MQTT-3.1.4-4]
-			s.unsubscribeClient(existing)
+			s.UnsubscribeClient(existing)
 			existing.ClearInflights(math.MaxInt64, 0)
 			return false // [MQTT-3.2.2-3]
 		}
@@ -592,6 +611,24 @@ func (s *Server) processPingreq(cl *Client, _ packets.Packet) error {
 	})
 }
 
+// Publish publishes a publish packet into the broker as if it were sent from the speicfied client.
+// This is a convenience function which wraps InjectPacket. As such, this method can publish packets
+// to any topic (including $SYS) and bypass ACL checks. The qos byte is used for limiting the
+// outbound qos (mqtt v5) rather than issuing to the broker (we assume qos 2 complete).
+func (s *Server) Publish(topic string, payload []byte, retain bool, qos byte) error {
+	cl := s.NewClient(nil, "local", "inline", true)
+	return s.InjectPacket(cl, packets.Packet{
+		FixedHeader: packets.FixedHeader{
+			Type:   packets.Publish,
+			Qos:    qos,
+			Retain: retain,
+		},
+		TopicName: topic,
+		Payload:   payload,
+		PacketID:  uint16(qos), // we never process the inbound qos, but we need a packet id for validity checks.
+	})
+}
+
 // InjectPacket injects a packet into the broker as if it were sent from the specified client.
 // InlineClients using this method can publish packets to any topic (including $SYS) and bypass ACL checks.
 func (s *Server) InjectPacket(cl *Client, pk packets.Packet) error {
@@ -627,7 +664,7 @@ func (s *Server) processPublish(cl *Client, pk packets.Packet) error {
 	pk.Origin = cl.ID
 	pk.Created = time.Now().Unix()
 
-	if pki, ok := cl.State.Inflight.Get(pk.PacketID); ok {
+	if pki, ok := cl.State.Inflight.Get(pk.PacketID); ok && !cl.Net.Inline {
 		if pki.FixedHeader.Type == packets.Pubrec { // [MQTT-4.3.3-10]
 			ack := s.buildAck(pk.PacketID, packets.Pubrec, 0, pk.Properties, packets.ErrPacketIdentifierInUse)
 			return cl.WritePacket(ack)
@@ -660,6 +697,7 @@ func (s *Server) processPublish(cl *Client, pk packets.Packet) error {
 			s.publishToSubscribers(pk)
 		})
 
+		s.hooks.OnPublished(cl, pk)
 		return nil
 	}
 
@@ -690,8 +728,7 @@ func (s *Server) processPublish(cl *Client, pk packets.Packet) error {
 		s.publishToSubscribers(pk)
 	})
 
-	s.hooks.OnPublish(cl, pk)
-
+	s.hooks.OnPublished(cl, pk)
 	return nil
 }
 
@@ -1035,14 +1072,20 @@ func (s *Server) processUnsubscribe(cl *Client, pk packets.Packet) error {
 	return cl.WritePacket(ack)
 }
 
-// unsubscribeClient unsubscribes a client from all of their subscriptions.
-func (s *Server) unsubscribeClient(cl *Client) {
-	for k := range cl.State.Subscriptions.GetAll() {
+// UnsubscribeClient unsubscribes a client from all of their subscriptions.
+func (s *Server) UnsubscribeClient(cl *Client) {
+	i := 0
+	filterMap := cl.State.Subscriptions.GetAll()
+	filters := make([]packets.Subscription, len(filterMap))
+	for k, v := range filterMap {
 		cl.State.Subscriptions.Delete(k)
 		if s.Topics.Unsubscribe(k, cl.ID) {
 			atomic.AddInt64(&s.Info.Subscriptions, -1)
 		}
+		filters[i] = v
+		i++
 	}
+	s.hooks.OnUnsubscribed(cl, packets.Packet{Filters: filters})
 }
 
 // processAuth processes an Auth packet.
@@ -1087,9 +1130,14 @@ func (s *Server) DisconnectClient(cl *Client, code packets.Code) error {
 		out.Properties.ReasonString = code.Reason //  // [MQTT-3.14.2-1]
 	}
 
+	// We already have a code we are using to disconnect the client, so we are not
+	// interested if the write packet fails due to a closed connection (as we are closing it).
 	err := cl.WritePacket(out)
 	if !s.Options.Capabilities.Compatibilities.PassiveClientDisconnect {
 		cl.Stop(code)
+		if code.Code >= packets.ErrUnspecifiedError.Code {
+			return code
+		}
 	}
 
 	return err
@@ -1304,9 +1352,7 @@ func (s *Server) loadSubscriptions(v []storage.Subscription) {
 // loadClients restores clients from the datastore.
 func (s *Server) loadClients(v []storage.Client) {
 	for _, c := range v {
-		cl := newClientStub()
-		cl.ID = c.ID
-		cl.Net.Listener = c.Listener
+		cl := s.NewClient(nil, c.Listener, c.ID, false)
 		cl.Properties.Username = c.Username
 		cl.Properties.Clean = c.Clean
 		cl.Properties.ProtocolVersion = c.ProtocolVersion

server_test.go

@@ -102,7 +102,34 @@ func TestNewNilOpts(t *testing.T) {
 	require.NotNil(t, s.Options)
 }
 
-func TestAddHook(t *testing.T) {
+func TestServerNewClient(t *testing.T) {
+	s := New(nil)
+	s.Log = &logger
+	r, _ := net.Pipe()
+
+	cl := s.NewClient(r, "testing", "test", false)
+	require.NotNil(t, cl)
+	require.Equal(t, "test", cl.ID)
+	require.Equal(t, "testing", cl.Net.Listener)
+	require.False(t, cl.Net.Inline)
+	require.NotNil(t, cl.State.Inflight.internal)
+	require.NotNil(t, cl.State.Subscriptions)
+	require.NotNil(t, cl.State.TopicAliases)
+	require.Equal(t, defaultKeepalive, cl.State.keepalive)
+	require.Equal(t, defaultClientProtocolVersion, cl.Properties.ProtocolVersion)
+	require.NotNil(t, cl.Net.conn)
+	require.NotNil(t, cl.Net.bconn)
+	require.NotNil(t, cl.ops)
+	require.Equal(t, s.Log, cl.ops.log)
+}
+
+func TestServerNewClientInline(t *testing.T) {
+	s := New(nil)
+	cl := s.NewClient(nil, "testing", "test", true)
+	require.True(t, cl.Net.Inline)
+}
+
+func TestServerAddHook(t *testing.T) {
 	s := New(nil)
 	s.Log = &logger
 	require.NotNil(t, s)
@@ -113,7 +140,7 @@ func TestAddHook(t *testing.T) {
 	require.Equal(t, int64(1), s.hooks.Len())
 }
 
-func TestAddListener(t *testing.T) {
+func TestServerAddListener(t *testing.T) {
 	s := newServer()
 	defer s.Close()
 
@@ -128,7 +155,7 @@ func TestAddListener(t *testing.T) {
 	require.Equal(t, ErrListenerIDExists, err)
 }
 
-func TestAddListenerInitFailure(t *testing.T) {
+func TestServerAddListenerInitFailure(t *testing.T) {
 	s := newServer()
 	defer s.Close()
 
@@ -197,7 +224,7 @@ func TestServerReadConnectionPacket(t *testing.T) {
 	s := newServer()
 	defer s.Close()
 
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	s.Clients.Add(cl)
 
 	o := make(chan packets.Packet)
@@ -219,7 +246,7 @@ func TestServerReadConnectionPacketBadFixedHeader(t *testing.T) {
 	s := newServer()
 	defer s.Close()
 
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	s.Clients.Add(cl)
 
 	o := make(chan error)
@@ -242,7 +269,7 @@ func TestServerReadConnectionPacketBadPacketType(t *testing.T) {
 	s := newServer()
 	defer s.Close()
 
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	s.Clients.Add(cl)
 
 	go func() {
@@ -259,7 +286,7 @@ func TestServerReadConnectionPacketBadPacket(t *testing.T) {
 	s := newServer()
 	defer s.Close()
 
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	s.Clients.Add(cl)
 
 	go func() {
@@ -377,7 +404,7 @@ func TestEstablishConnectionInheritExisting(t *testing.T) {
 	s := newServer()
 	defer s.Close()
 
-	cl, r0, _ := newClient()
+	cl, r0, _ := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	cl.ID = packets.TPacketData[packets.Connect].Get(packets.TConnectMqtt311).Packet.Connect.ClientIdentifier
 	cl.State.Subscriptions.Add("a/b/c", packets.Subscription{Filter: "a/b/c", Qos: 1})
@@ -438,7 +465,7 @@ func TestEstablishConnectionResentPendingInflightsError(t *testing.T) {
 	defer s.Close()
 
 	n := time.Now().Unix()
-	cl, r0, _ := newClient()
+	cl, r0, _ := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	cl.ID = packets.TPacketData[packets.Connect].Get(packets.TConnectMqtt311).Packet.Connect.ClientIdentifier
 	cl.State.Inflight = NewInflights()
@@ -474,7 +501,7 @@ func TestEstablishConnectionInheritExistingClean(t *testing.T) {
 	s := newServer()
 	defer s.Close()
 
-	cl, r0, _ := newClient()
+	cl, r0, _ := newTestClient()
 	cl.ID = packets.TPacketData[packets.Connect].Get(packets.TConnectMqtt311).Packet.Connect.ClientIdentifier
 	cl.Properties.Clean = true
 	cl.State.Subscriptions.Add("a/b/c", packets.Subscription{Filter: "a/b/c", Qos: 1})
@@ -660,7 +687,7 @@ func TestServerEstablishConnectionBadPacket(t *testing.T) {
 
 func TestServerSendConnack(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	s.Options.Capabilities.ServerKeepAlive = 20
 	s.Options.Capabilities.MaximumQos = 1
@@ -680,7 +707,7 @@ func TestServerSendConnack(t *testing.T) {
 
 func TestServerSendConnackFailureReason(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	s.Options.Capabilities.ServerKeepAlive = 20
 	go func() {
@@ -758,7 +785,7 @@ func TestServerValidateConnect(t *testing.T) {
 
 func TestServerSendConnackAdjustedExpiryInterval(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	cl.Properties.Props.SessionExpiryInterval = uint32(300)
 	s.Options.Capabilities.MaximumSessionExpiryInterval = 120
@@ -778,7 +805,7 @@ func TestInheritClientSession(t *testing.T) {
 
 	n := time.Now().Unix()
 
-	existing, _, _ := newClient()
+	existing, _, _ := newTestClient()
 	existing.Net.conn = nil
 	existing.ID = "mochi"
 	existing.State.Subscriptions.Add("a/b/c", packets.Subscription{Filter: "a/b/c", Qos: 1})
@@ -788,7 +815,7 @@ func TestInheritClientSession(t *testing.T) {
 
 	s.Clients.Add(existing)
 
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 
 	require.Equal(t, 0, cl.State.Inflight.Len())
@@ -801,7 +828,7 @@ func TestInheritClientSession(t *testing.T) {
 	require.Equal(t, 1, cl.State.Subscriptions.Len())
 
 	// On clean, clear existing properties
-	cl, _, _ = newClient()
+	cl, _, _ = newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	b = s.inheritClientSession(packets.Packet{Connect: packets.ConnectParams{ClientIdentifier: "mochi", Clean: true}}, cl)
 	require.False(t, b)
@@ -811,27 +838,27 @@ func TestInheritClientSession(t *testing.T) {
 
 func TestServerUnsubscribeClient(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	pk := packets.Subscription{Filter: "a/b/c", Qos: 1}
 	cl.State.Subscriptions.Add("a/b/c", pk)
 	s.Topics.Subscribe(cl.ID, pk)
 	subs := s.Topics.Subscribers("a/b/c")
 	require.Equal(t, 1, len(subs.Subscriptions))
-	s.unsubscribeClient(cl)
+	s.UnsubscribeClient(cl)
 	subs = s.Topics.Subscribers("a/b/c")
 	require.Equal(t, 0, len(subs.Subscriptions))
 }
 
 func TestServerProcessPacketFailure(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	err := s.processPacket(cl, packets.Packet{})
 	require.Error(t, err)
 }
 
 func TestServerProcessPacketConnect(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 
 	err := s.processPacket(cl, *packets.TPacketData[packets.Connect].Get(packets.TConnectClean).Packet)
 	require.Error(t, err)
@@ -839,7 +866,7 @@ func TestServerProcessPacketConnect(t *testing.T) {
 
 func TestServerProcessPacketPingreq(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 
 	go func() {
 		err := s.processPacket(cl, *packets.TPacketData[packets.Pingreq].Get(packets.TPingreq).Packet)
@@ -854,7 +881,7 @@ func TestServerProcessPacketPingreq(t *testing.T) {
 
 func TestServerProcessPacketPingreqError(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.Stop(packets.CodeDisconnect)
 
 	err := s.processPacket(cl, *packets.TPacketData[packets.Pingreq].Get(packets.TPingreq).Packet)
@@ -864,7 +891,7 @@ func TestServerProcessPacketPingreqError(t *testing.T) {
 
 func TestServerProcessPacketPublishInvalid(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 
 	err := s.processPacket(cl, *packets.TPacketData[packets.Publish].Get(packets.TPublishInvalidQosMustPacketID).Packet)
 	require.Error(t, err)
@@ -876,12 +903,12 @@ func TestInjectPacketPublishAndReceive(t *testing.T) {
 	s.Serve()
 	defer s.Close()
 
-	sender, _, w1 := newClient()
+	sender, _, w1 := newTestClient()
 	sender.Net.Inline = true
 	sender.ID = "sender"
 	s.Clients.Add(sender)
 
-	receiver, r2, w2 := newClient()
+	receiver, r2, w2 := newTestClient()
 	receiver.ID = "receiver"
 	s.Clients.Add(receiver)
 	s.Topics.Subscribe(receiver.ID, packets.Subscription{Filter: "a/b/c"})
@@ -906,10 +933,46 @@ func TestInjectPacketPublishAndReceive(t *testing.T) {
 	require.Equal(t, packets.TPacketData[packets.Publish].Get(packets.TPublishBasic).RawBytes, <-receiverBuf)
 }
 
+func TestServerDirectPublishAndReceive(t *testing.T) {
+	s := newServer()
+	s.Serve()
+	defer s.Close()
+
+	sender, _, w1 := newTestClient()
+	sender.Net.Inline = true
+	sender.ID = "sender"
+	s.Clients.Add(sender)
+
+	receiver, r2, w2 := newTestClient()
+	receiver.ID = "receiver"
+	s.Clients.Add(receiver)
+	s.Topics.Subscribe(receiver.ID, packets.Subscription{Filter: "a/b/c"})
+
+	require.Equal(t, int64(0), atomic.LoadInt64(&s.Info.PacketsReceived))
+
+	receiverBuf := make(chan []byte)
+	go func() {
+		buf, err := io.ReadAll(r2)
+		require.NoError(t, err)
+		receiverBuf <- buf
+	}()
+
+	go func() {
+		pkx := *packets.TPacketData[packets.Publish].Get(packets.TPublishBasic).Packet
+		err := s.Publish(pkx.TopicName, pkx.Payload, pkx.FixedHeader.Retain, pkx.FixedHeader.Qos)
+		require.NoError(t, err)
+		w1.Close()
+		time.Sleep(time.Millisecond * 10)
+		w2.Close()
+	}()
+
+	require.Equal(t, packets.TPacketData[packets.Publish].Get(packets.TPublishBasic).RawBytes, <-receiverBuf)
+}
+
 func TestInjectPacketError(t *testing.T) {
 	s := newServer()
 	defer s.Close()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.Net.Inline = true
 	pkx := *packets.TPacketData[packets.Subscribe].Get(packets.TSubscribe).Packet
 	pkx.Filters = packets.Subscriptions{}
@@ -920,7 +983,7 @@ func TestInjectPacketError(t *testing.T) {
 func TestInjectPacketPublishInvalidTopic(t *testing.T) {
 	s := newServer()
 	defer s.Close()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.Net.Inline = true
 	pkx := *packets.TPacketData[packets.Publish].Get(packets.TPublishBasic).Packet
 	pkx.TopicName = "$SYS/test"
@@ -933,11 +996,11 @@ func TestServerProcessPacketPublishAndReceive(t *testing.T) {
 	s.Serve()
 	defer s.Close()
 
-	sender, _, w1 := newClient()
+	sender, _, w1 := newTestClient()
 	sender.ID = "sender"
 	s.Clients.Add(sender)
 
-	receiver, r2, w2 := newClient()
+	receiver, r2, w2 := newTestClient()
 	receiver.ID = "receiver"
 	s.Clients.Add(receiver)
 	s.Topics.Subscribe(receiver.ID, packets.Subscription{Filter: "a/b/c"})
@@ -966,7 +1029,7 @@ func TestServerProcessPacketPublishAndReceive(t *testing.T) {
 
 func TestServerProcessPacketAndNextImmediate(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 
 	next := *packets.TPacketData[packets.Publish].Get(packets.TPublishQos1).Packet
 	next.Expiry = -1
@@ -993,7 +1056,7 @@ func TestServerProcessPacketPublishAckFailure(t *testing.T) {
 	s.Serve()
 	defer s.Close()
 
-	cl, _, w := newClient()
+	cl, _, w := newTestClient()
 	s.Clients.Add(cl)
 
 	w.Close()
@@ -1007,14 +1070,15 @@ func TestServerProcessPacketPublishMaximumReceive(t *testing.T) {
 	s.Serve()
 	defer s.Close()
 
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	cl.State.Inflight.ResetReceiveQuota(0)
 	s.Clients.Add(cl)
 
 	go func() {
 		err := s.processPacket(cl, *packets.TPacketData[packets.Publish].Get(packets.TPublishQos1).Packet)
-		require.NoError(t, err)
+		require.Error(t, err)
+		require.ErrorIs(t, err, packets.ErrReceiveMaximum)
 		w.Close()
 	}()
 
@@ -1027,7 +1091,7 @@ func TestServerProcessPublishInvalidTopic(t *testing.T) {
 	s := newServer()
 	s.Serve()
 	defer s.Close()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	err := s.processPublish(cl, *packets.TPacketData[packets.Publish].Get(packets.TPublishSpecDenySysTopic).Packet)
 	require.NoError(t, err) // $SYS topics should be ignored?
 }
@@ -1040,7 +1104,7 @@ func TestServerProcessPublishACLCheckDeny(t *testing.T) {
 	})
 	s.Serve()
 	defer s.Close()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	err := s.processPublish(cl, *packets.TPacketData[packets.Publish].Get(packets.TPublishBasic).Packet)
 	require.NoError(t, err) // ACL check fails silently
 }
@@ -1057,14 +1121,14 @@ func TestServerProcessPublishOnMessageRecvRejected(t *testing.T) {
 
 	s.Serve()
 	defer s.Close()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	err = s.processPublish(cl, *packets.TPacketData[packets.Publish].Get(packets.TPublishBasic).Packet)
 	require.NoError(t, err) // packets rejected silently
 }
 
 func TestServerProcessPacketPublishQos0(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 
 	go func() {
 		err := s.processPacket(cl, *packets.TPacketData[packets.Publish].Get(packets.TPublishBasic).Packet)
@@ -1079,7 +1143,7 @@ func TestServerProcessPacketPublishQos0(t *testing.T) {
 
 func TestServerProcessPacketPublishQos1PacketIDInUse(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.State.Inflight.Set(packets.Packet{PacketID: 7, FixedHeader: packets.FixedHeader{Type: packets.Publish}})
 	atomic.StoreInt64(&s.Info.Inflight, 1)
 
@@ -1097,7 +1161,7 @@ func TestServerProcessPacketPublishQos1PacketIDInUse(t *testing.T) {
 
 func TestServerProcessPacketPublishQos2PacketIDInUse(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	cl.State.Inflight.Set(packets.Packet{PacketID: 7, FixedHeader: packets.FixedHeader{Type: packets.Pubrec}})
 	atomic.StoreInt64(&s.Info.Inflight, 1)
@@ -1116,7 +1180,7 @@ func TestServerProcessPacketPublishQos2PacketIDInUse(t *testing.T) {
 
 func TestServerProcessPacketPublishQos1(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 
 	go func() {
 		err := s.processPacket(cl, *packets.TPacketData[packets.Publish].Get(packets.TPublishQos1).Packet)
@@ -1131,7 +1195,7 @@ func TestServerProcessPacketPublishQos1(t *testing.T) {
 
 func TestServerProcessPacketPublishQos2(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 
 	go func() {
 		err := s.processPacket(cl, *packets.TPacketData[packets.Publish].Get(packets.TPublishQos2).Packet)
@@ -1147,7 +1211,7 @@ func TestServerProcessPacketPublishQos2(t *testing.T) {
 func TestServerProcessPacketPublishDowngradeQos(t *testing.T) {
 	s := newServer()
 	s.Options.Capabilities.MaximumQos = 1
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 
 	go func() {
 		err := s.processPacket(cl, *packets.TPacketData[packets.Publish].Get(packets.TPublishQos2).Packet)
@@ -1162,7 +1226,7 @@ func TestServerProcessPacketPublishDowngradeQos(t *testing.T) {
 
 func TestPublishToSubscribersSelfNoLocal(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	s.Clients.Add(cl)
 	subbed := s.Topics.Subscribe(cl.ID, packets.Subscription{Filter: "a/b/c", NoLocal: true})
 	require.True(t, subbed)
@@ -1187,11 +1251,11 @@ func TestPublishToSubscribersSelfNoLocal(t *testing.T) {
 
 func TestPublishToSubscribers(t *testing.T) {
 	s := newServer()
-	cl, r1, w1 := newClient()
+	cl, r1, w1 := newTestClient()
 	cl.ID = "cl1"
-	cl2, r2, w2 := newClient()
+	cl2, r2, w2 := newTestClient()
 	cl2.ID = "cl2"
-	cl3, r3, w3 := newClient()
+	cl3, r3, w3 := newTestClient()
 	cl3.ID = "cl3"
 	s.Clients.Add(cl)
 	s.Clients.Add(cl2)
@@ -1249,7 +1313,7 @@ func TestPublishToSubscribers(t *testing.T) {
 func TestPublishToSubscribersMessageExpiryDelta(t *testing.T) {
 	s := newServer()
 	s.Options.Capabilities.MaximumMessageExpiryInterval = 86400
-	cl, r1, w1 := newClient()
+	cl, r1, w1 := newTestClient()
 	cl.ID = "cl1"
 	cl.Properties.ProtocolVersion = 5
 	s.Clients.Add(cl)
@@ -1278,7 +1342,7 @@ func TestPublishToSubscribersMessageExpiryDelta(t *testing.T) {
 
 func TestPublishToSubscribersIdentifiers(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	s.Clients.Add(cl)
 	subbed := s.Topics.Subscribe(cl.ID, packets.Subscription{Filter: "a/b/+", Identifier: 2})
@@ -1308,7 +1372,7 @@ func TestPublishToClientServerDowngradeQos(t *testing.T) {
 	s := newServer()
 	s.Options.Capabilities.MaximumQos = 1
 
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	s.Clients.Add(cl)
 
 	_, ok := cl.State.Inflight.Get(1)
@@ -1334,7 +1398,7 @@ func TestPublishToClientServerDowngradeQos(t *testing.T) {
 
 func TestPublishToClientServerTopicAlias(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	cl.Properties.Props.TopicAliasMaximum = 5
 	s.Clients.Add(cl)
@@ -1363,7 +1427,7 @@ func TestPublishToClientServerTopicAlias(t *testing.T) {
 
 func TestPublishToClientExhaustedPacketID(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	for i := 0; i <= 65535; i++ {
 		cl.State.Inflight.Set(packets.Packet{PacketID: uint16(i)})
 	}
@@ -1375,7 +1439,7 @@ func TestPublishToClientExhaustedPacketID(t *testing.T) {
 
 func TestPublishToClientNoConn(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.Net.conn = nil
 
 	_, err := s.publishToClient(cl, packets.Subscription{Filter: "a/b/c"}, *packets.TPacketData[packets.Publish].Get(packets.TPublishQos1).Packet)
@@ -1385,12 +1449,12 @@ func TestPublishToClientNoConn(t *testing.T) {
 
 func TestProcessPublishWithTopicAlias(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	s.Clients.Add(cl)
 	subbed := s.Topics.Subscribe(cl.ID, packets.Subscription{Filter: "a/b/c", Qos: 0})
 	require.True(t, subbed)
 
-	cl2, _, w2 := newClient()
+	cl2, _, w2 := newTestClient()
 	cl2.Properties.ProtocolVersion = 5
 	cl2.State.TopicAliases.Inbound.Set(1, "a/b/c")
 
@@ -1412,7 +1476,7 @@ func TestProcessPublishWithTopicAlias(t *testing.T) {
 
 func TestPublishToSubscribersExhaustedSendQuota(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	s.Clients.Add(cl)
 	cl.State.Inflight.sendQuota = 0
 
@@ -1431,7 +1495,7 @@ func TestPublishToSubscribersExhaustedSendQuota(t *testing.T) {
 
 func TestPublishToSubscribersExhaustedPacketIDs(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	s.Clients.Add(cl)
 	for i := 0; i <= 65535; i++ {
 		cl.State.Inflight.Set(packets.Packet{PacketID: 1})
@@ -1452,7 +1516,7 @@ func TestPublishToSubscribersExhaustedPacketIDs(t *testing.T) {
 
 func TestPublishToSubscribersNoConnection(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	s.Clients.Add(cl)
 	subbed := s.Topics.Subscribe(cl.ID, packets.Subscription{Filter: "a/b/c", Qos: 2})
 	require.True(t, subbed)
@@ -1467,7 +1531,7 @@ func TestPublishToSubscribersNoConnection(t *testing.T) {
 
 func TestPublishRetainedToClient(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	s.Clients.Add(cl)
 
 	subbed := s.Topics.Subscribe(cl.ID, packets.Subscription{Filter: "a/b/c", Qos: 2})
@@ -1489,7 +1553,7 @@ func TestPublishRetainedToClient(t *testing.T) {
 
 func TestPublishRetainedToClientIsShared(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	s.Clients.Add(cl)
 
 	sub := packets.Subscription{Filter: SharePrefix + "/test/a/b/c"}
@@ -1508,7 +1572,7 @@ func TestPublishRetainedToClientIsShared(t *testing.T) {
 
 func TestPublishRetainedToClientError(t *testing.T) {
 	s := newServer()
-	cl, _, w := newClient()
+	cl, _, w := newTestClient()
 	s.Clients.Add(cl)
 
 	sub := packets.Subscription{Filter: "a/b/c"}
@@ -1538,7 +1602,7 @@ func TestServerProcessPacketPuback(t *testing.T) {
 		t.Run(strconv.Itoa(int(tx.protocolVersion)), func(t *testing.T) {
 			pID := uint16(7)
 			s := newServer()
-			cl, _, _ := newClient()
+			cl, _, _ := newTestClient()
 			cl.State.Inflight.sendQuota = 3
 			cl.State.Inflight.receiveQuota = 3
 
@@ -1560,7 +1624,7 @@ func TestServerProcessPacketPuback(t *testing.T) {
 
 func TestServerProcessPacketPubackNoPacketID(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.State.Inflight.sendQuota = 3
 	cl.State.Inflight.receiveQuota = 3
 
@@ -1575,7 +1639,7 @@ func TestServerProcessPacketPubackNoPacketID(t *testing.T) {
 func TestServerProcessPacketPubrec(t *testing.T) {
 	pID := uint16(7)
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.State.Inflight.sendQuota = 3
 	cl.State.Inflight.receiveQuota = 3
 
@@ -1604,7 +1668,7 @@ func TestServerProcessPacketPubrec(t *testing.T) {
 
 func TestServerProcessPacketPubrecNoPacketID(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	cl.State.Inflight.sendQuota = 3
 	cl.State.Inflight.receiveQuota = 3
@@ -1630,7 +1694,7 @@ func TestServerProcessPacketPubrecNoPacketID(t *testing.T) {
 func TestServerProcessPacketPubrecInvalidReason(t *testing.T) {
 	pID := uint16(7)
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.State.Inflight.Set(packets.Packet{PacketID: pID})
 	err := s.processPacket(cl, *packets.TPacketData[packets.Pubrec].Get(packets.TPubrecInvalidReason).Packet)
 	require.NoError(t, err)
@@ -1642,7 +1706,7 @@ func TestServerProcessPacketPubrecInvalidReason(t *testing.T) {
 func TestServerProcessPacketPubrecFailure(t *testing.T) {
 	pID := uint16(7)
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.State.Inflight.Set(packets.Packet{PacketID: pID})
 	cl.Stop(packets.CodeDisconnect)
 	err := s.processPacket(cl, *packets.TPacketData[packets.Pubrec].Get(packets.TPubrec).Packet)
@@ -1653,7 +1717,7 @@ func TestServerProcessPacketPubrecFailure(t *testing.T) {
 func TestServerProcessPacketPubrel(t *testing.T) {
 	pID := uint16(7)
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.State.Inflight.sendQuota = 3
 	cl.State.Inflight.receiveQuota = 3
 
@@ -1683,7 +1747,7 @@ func TestServerProcessPacketPubrel(t *testing.T) {
 
 func TestServerProcessPacketPubrelNoPacketID(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	cl.State.Inflight.sendQuota = 3
 	cl.State.Inflight.receiveQuota = 3
@@ -1709,7 +1773,7 @@ func TestServerProcessPacketPubrelNoPacketID(t *testing.T) {
 func TestServerProcessPacketPubrelFailure(t *testing.T) {
 	pID := uint16(7)
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.State.Inflight.Set(packets.Packet{PacketID: pID})
 	cl.Stop(packets.CodeDisconnect)
 	err := s.processPacket(cl, *packets.TPacketData[packets.Pubrel].Get(packets.TPubrel).Packet)
@@ -1720,7 +1784,7 @@ func TestServerProcessPacketPubrelFailure(t *testing.T) {
 func TestServerProcessPacketPubrelBadReason(t *testing.T) {
 	pID := uint16(7)
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.State.Inflight.Set(packets.Packet{PacketID: pID})
 	err := s.processPacket(cl, *packets.TPacketData[packets.Pubrel].Get(packets.TPubrelInvalidReason).Packet)
 	require.NoError(t, err)
@@ -1745,7 +1809,7 @@ func TestServerProcessPacketPubcomp(t *testing.T) {
 		t.Run(strconv.Itoa(int(tx.protocolVersion)), func(t *testing.T) {
 			pID := uint16(7)
 			s := newServer()
-			cl, _, _ := newClient()
+			cl, _, _ := newTestClient()
 			cl.Properties.ProtocolVersion = tx.protocolVersion
 			cl.State.Inflight.sendQuota = 3
 			cl.State.Inflight.receiveQuota = 3
@@ -1792,7 +1856,7 @@ func TestServerProcessInboundQos2Flow(t *testing.T) {
 
 	pID := uint16(7)
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.State.Inflight.sendQuota = 3
 	cl.State.Inflight.receiveQuota = 3
 
@@ -1863,7 +1927,7 @@ func TestServerProcessOutboundQos2Flow(t *testing.T) {
 
 	pID := uint16(6)
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.State.packetID = uint32(6)
 	cl.State.Inflight.sendQuota = 3
 	cl.State.Inflight.receiveQuota = 3
@@ -1907,7 +1971,7 @@ func TestServerProcessOutboundQos2Flow(t *testing.T) {
 
 func TestServerProcessPacketSubscribe(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	go func() {
 		err := s.processPacket(cl, *packets.TPacketData[packets.Subscribe].Get(packets.TSubscribeMqtt5).Packet)
@@ -1922,7 +1986,7 @@ func TestServerProcessPacketSubscribe(t *testing.T) {
 
 func TestServerProcessPacketSubscribePacketIDInUse(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	cl.State.Inflight.Set(packets.Packet{PacketID: 15, FixedHeader: packets.FixedHeader{Type: packets.Publish}})
 
@@ -1941,7 +2005,7 @@ func TestServerProcessPacketSubscribePacketIDInUse(t *testing.T) {
 
 func TestServerProcessPacketSubscribeInvalid(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 
 	err := s.processPacket(cl, *packets.TPacketData[packets.Subscribe].Get(packets.TSubscribeSpecQosMustPacketID).Packet)
@@ -1951,7 +2015,7 @@ func TestServerProcessPacketSubscribeInvalid(t *testing.T) {
 
 func TestServerProcessPacketSubscribeInvalidFilter(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 
 	go func() {
@@ -1967,7 +2031,7 @@ func TestServerProcessPacketSubscribeInvalidFilter(t *testing.T) {
 
 func TestServerProcessPacketSubscribeInvalidSharedNoLocal(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 
 	go func() {
@@ -1983,7 +2047,7 @@ func TestServerProcessPacketSubscribeInvalidSharedNoLocal(t *testing.T) {
 
 func TestServerProcessSubscribeWithRetain(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 
 	retained := s.Topics.RetainMessage(*packets.TPacketData[packets.Publish].Get(packets.TPublishRetain).Packet)
 	require.Equal(t, int64(1), retained)
@@ -2007,7 +2071,7 @@ func TestServerProcessSubscribeWithRetain(t *testing.T) {
 func TestServerProcessSubscribeDowngradeQos(t *testing.T) {
 	s := newServer()
 	s.Options.Capabilities.MaximumQos = 1
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 
 	go func() {
 		err := s.processPacket(cl, *packets.TPacketData[packets.Subscribe].Get(packets.TSubscribeMany).Packet)
@@ -2024,7 +2088,7 @@ func TestServerProcessSubscribeDowngradeQos(t *testing.T) {
 
 func TestServerProcessSubscribeWithRetainHandling1(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	s.Topics.Subscribe(cl.ID, packets.Subscription{Filter: "a/b/c"})
 	s.Clients.Add(cl)
 
@@ -2046,7 +2110,7 @@ func TestServerProcessSubscribeWithRetainHandling1(t *testing.T) {
 
 func TestServerProcessSubscribeWithRetainHandling2(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	s.Clients.Add(cl)
 
 	retained := s.Topics.RetainMessage(*packets.TPacketData[packets.Publish].Get(packets.TPublishRetain).Packet)
@@ -2067,7 +2131,7 @@ func TestServerProcessSubscribeWithRetainHandling2(t *testing.T) {
 
 func TestServerProcessSubscribeWithNotRetainAsPublished(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	s.Clients.Add(cl)
 
 	retained := s.Topics.RetainMessage(*packets.TPacketData[packets.Publish].Get(packets.TPublishRetain).Packet)
@@ -2091,7 +2155,7 @@ func TestServerProcessSubscribeWithNotRetainAsPublished(t *testing.T) {
 
 func TestServerProcessSubscribeNoConnection(t *testing.T) {
 	s := newServer()
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	r.Close()
 	err := s.processSubscribe(cl, *packets.TPacketData[packets.Subscribe].Get(packets.TSubscribe).Packet)
 	require.Error(t, err)
@@ -2105,7 +2169,7 @@ func TestServerProcessSubscribeACLCheckDeny(t *testing.T) {
 		FanPoolQueueSize: 10,
 	})
 	s.Serve()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 
 	go func() {
@@ -2127,7 +2191,7 @@ func TestServerProcessSubscribeACLCheckDenyObscure(t *testing.T) {
 	})
 	s.Serve()
 	s.Options.Capabilities.Compatibilities.ObscureNotAuthorized = true
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 
 	go func() {
@@ -2143,7 +2207,7 @@ func TestServerProcessSubscribeACLCheckDenyObscure(t *testing.T) {
 
 func TestServerProcessSubscribeErrorDowngrade(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 3
 	cl.State.packetID = 1 // just to match the same packet id (7) in the fixtures
 
@@ -2160,7 +2224,7 @@ func TestServerProcessSubscribeErrorDowngrade(t *testing.T) {
 
 func TestServerProcessPacketUnsubscribe(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	s.Topics.Subscribe(cl.ID, packets.Subscription{Filter: "a/b", Qos: 0})
 	go func() {
@@ -2177,7 +2241,7 @@ func TestServerProcessPacketUnsubscribe(t *testing.T) {
 
 func TestServerProcessPacketUnsubscribePackedIDInUse(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.ProtocolVersion = 5
 	cl.State.Inflight.Set(packets.Packet{PacketID: 15, FixedHeader: packets.FixedHeader{Type: packets.Publish}})
 	go func() {
@@ -2194,7 +2258,7 @@ func TestServerProcessPacketUnsubscribePackedIDInUse(t *testing.T) {
 
 func TestServerProcessPacketUnsubscribeInvalid(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	err := s.processPacket(cl, *packets.TPacketData[packets.Unsubscribe].Get(packets.TUnsubscribeSpecQosMustPacketID).Packet)
 	require.Error(t, err)
 	require.ErrorIs(t, err, packets.ErrProtocolViolationNoPacketID)
@@ -2202,7 +2266,7 @@ func TestServerProcessPacketUnsubscribeInvalid(t *testing.T) {
 
 func TestServerReceivePacketError(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	err := s.receivePacket(cl, *packets.TPacketData[packets.Unsubscribe].Get(packets.TUnsubscribeSpecQosMustPacketID).Packet)
 	require.Error(t, err)
 	require.ErrorIs(t, err, packets.ErrProtocolViolationNoPacketID)
@@ -2210,7 +2274,7 @@ func TestServerReceivePacketError(t *testing.T) {
 
 func TestServerRecievePacketDisconnectClientZeroNonZero(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 	cl.Properties.Props.SessionExpiryInterval = 0
 	cl.Properties.ProtocolVersion = 5
 	cl.Properties.Props.RequestProblemInfo = 0
@@ -2227,9 +2291,24 @@ func TestServerRecievePacketDisconnectClientZeroNonZero(t *testing.T) {
 	require.Equal(t, packets.TPacketData[packets.Disconnect].Get(packets.TDisconnectZeroNonZeroExpiry).RawBytes, buf)
 }
 
+func TestServerRecievePacketDisconnectClient(t *testing.T) {
+	s := newServer()
+	cl, r, w := newTestClient()
+
+	go func() {
+		err := s.DisconnectClient(cl, packets.CodeDisconnect)
+		require.NoError(t, err)
+		w.Close()
+	}()
+
+	buf, err := io.ReadAll(r)
+	require.NoError(t, err)
+	require.Equal(t, packets.TPacketData[packets.Disconnect].Get(packets.TDisconnect).RawBytes, buf)
+}
+
 func TestServerProcessPacketDisconnect(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.Properties.Props.SessionExpiryInterval = 30
 	cl.Properties.ProtocolVersion = 5
 
@@ -2246,7 +2325,7 @@ func TestServerProcessPacketDisconnect(t *testing.T) {
 
 func TestServerProcessPacketDisconnectNonZeroExpiryViolation(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.Properties.Props.SessionExpiryInterval = 0
 	cl.Properties.ProtocolVersion = 5
 	cl.Properties.Props.RequestProblemInfo = 0
@@ -2259,7 +2338,7 @@ func TestServerProcessPacketDisconnectNonZeroExpiryViolation(t *testing.T) {
 
 func TestServerProcessPacketAuth(t *testing.T) {
 	s := newServer()
-	cl, r, w := newClient()
+	cl, r, w := newTestClient()
 
 	go func() {
 		err := s.processPacket(cl, *packets.TPacketData[packets.Auth].Get(packets.TAuth).Packet)
@@ -2274,7 +2353,7 @@ func TestServerProcessPacketAuth(t *testing.T) {
 
 func TestServerProcessPacketAuthInvalidReason(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	pkx := *packets.TPacketData[packets.Auth].Get(packets.TAuth).Packet
 	pkx.ReasonCode = 99
 	err := s.processPacket(cl, pkx)
@@ -2284,7 +2363,7 @@ func TestServerProcessPacketAuthInvalidReason(t *testing.T) {
 
 func TestServerProcessPacketAuthFailure(t *testing.T) {
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 
 	hook := new(modifiedHookBase)
 	hook.fail = true
@@ -2301,7 +2380,7 @@ func TestServerSendLWT(t *testing.T) {
 	s.Serve()
 	defer s.Close()
 
-	sender, _, w1 := newClient()
+	sender, _, w1 := newTestClient()
 	sender.ID = "sender"
 	sender.Properties.Will = Will{
 		Flag:      1,
@@ -2310,7 +2389,7 @@ func TestServerSendLWT(t *testing.T) {
 	}
 	s.Clients.Add(sender)
 
-	receiver, r2, w2 := newClient()
+	receiver, r2, w2 := newTestClient()
 	receiver.ID = "receiver"
 	s.Clients.Add(receiver)
 	s.Topics.Subscribe(receiver.ID, packets.Subscription{Filter: "a/b/c", Qos: 0})
@@ -2337,7 +2416,7 @@ func TestServerSendLWT(t *testing.T) {
 
 func TestServerSendLWTDelayed(t *testing.T) {
 	s := newServer()
-	cl1, _, _ := newClient()
+	cl1, _, _ := newTestClient()
 	cl1.ID = "cl1"
 	cl1.Properties.Will = Will{
 		Flag:              1,
@@ -2348,7 +2427,7 @@ func TestServerSendLWTDelayed(t *testing.T) {
 	}
 	s.Clients.Add(cl1)
 
-	cl2, r, w := newClient()
+	cl2, r, w := newTestClient()
 	cl2.ID = "cl2"
 	s.Clients.Add(cl2)
 	require.True(t, s.Topics.Subscribe(cl2.ID, packets.Subscription{Filter: "a/b/c"}))
@@ -2426,7 +2505,7 @@ func TestServerLoadSubscriptions(t *testing.T) {
 	}
 
 	s := newServer()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	s.Clients.Add(cl)
 	require.Equal(t, 0, cl.State.Subscriptions.Len())
 	s.loadSubscriptions(v)
@@ -2486,7 +2565,7 @@ func TestServerClose(t *testing.T) {
 	hook := new(modifiedHookBase)
 	s.AddHook(hook, nil)
 
-	cl, r, _ := newClient()
+	cl, r, _ := newTestClient()
 	cl.Net.Listener = "t1"
 	cl.Properties.ProtocolVersion = 5
 	s.Clients.Add(cl)
@@ -2524,7 +2603,7 @@ func TestServerClearExpiredInflights(t *testing.T) {
 	s.Options.Capabilities.MaximumMessageExpiryInterval = 4
 
 	n := time.Now().Unix()
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.ops.info = s.Info
 
 	cl.State.Inflight.Set(packets.Packet{PacketID: 1, Expiry: n - 1})
@@ -2564,12 +2643,12 @@ func TestServerClearExpiredClients(t *testing.T) {
 
 	n := time.Now().Unix()
 
-	cl, _, _ := newClient()
+	cl, _, _ := newTestClient()
 	cl.ID = "cl"
 	s.Clients.Add(cl)
 
 	// No Expiry
-	cl0, _, _ := newClient()
+	cl0, _, _ := newTestClient()
 	cl0.ID = "c0"
 	cl0.State.disconnected = n - 10
 	cl0.State.done = 1
@@ -2579,7 +2658,7 @@ func TestServerClearExpiredClients(t *testing.T) {
 	s.Clients.Add(cl0)
 
 	// Normal Expiry
-	cl1, _, _ := newClient()
+	cl1, _, _ := newTestClient()
 	cl1.ID = "c1"
 	cl1.State.disconnected = n - 10
 	cl1.State.done = 1
@@ -2589,7 +2668,7 @@ func TestServerClearExpiredClients(t *testing.T) {
 	s.Clients.Add(cl1)
 
 	// No Expiry, indefinite session
-	cl2, _, _ := newClient()
+	cl2, _, _ := newTestClient()
 	cl2.ID = "c2"
 	cl2.State.disconnected = n - 10
 	cl2.State.done = 1