Go vendor update

vendor/github.com/eclipse/paho.mqtt.golang/README.md

@@ -113,7 +113,9 @@ identifier; this is as per the [spec](https://docs.oasis-open.org/mqtt/mqtt/v3.1
 not received, disconnecting` errors). 
 * When QOS1+ subscriptions have been created previously and you connect with `CleanSession` set to false it is possible 
 that the broker will deliver retained messages before `Subscribe` can be called. To process these messages either 
-configure a handler with `AddRoute` or set a `DefaultPublishHandler`.
+configure a handler with `AddRoute` or set a `DefaultPublishHandler`. If there is no handler (or `DefaultPublishHandler`) 
+then inbound messages will not be acknowledged. Adding a handler (even if it's  `opts.SetDefaultPublishHandler(func(mqtt.Client, mqtt.Message) {})`) 
+is highly recommended to avoid inadvertently hitting inflight message limits.
 * Loss of network connectivity may not be detected immediately. If this is an issue then consider setting 
 `ClientOptions.KeepAlive` (sends regular messages to check the link is active).
 * Reusing a `Client` is not completely safe. After calling `Disconnect` please create a new Client (`NewClient()`) rather 
@@ -193,4 +195,4 @@ Discussion of the Paho clients takes place on the [Eclipse paho-dev mailing list
 
 General questions about the MQTT protocol are discussed in the [MQTT Google Group](https://groups.google.com/forum/?hl=en-US&fromgroups#!forum/mqtt).
 
-There is much more information available via the [MQTT community site](http://mqtt.org).
+There is much more information available via the [MQTT community site](http://mqtt.org).

vendor/github.com/eclipse/paho.mqtt.golang/backoff.go

@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2021 IBM Corp and others.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v2.0
+ * and Eclipse Distribution License v1.0 which accompany this distribution.
+ *
+ * The Eclipse Public License is available at
+ *    https://www.eclipse.org/legal/epl-2.0/
+ * and the Eclipse Distribution License is available at
+ *   http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * Contributors:
+ *    Matt Brittan
+ *    Daichi Tomaru
+ */
+
+package mqtt
+
+import (
+	"sync"
+	"time"
+)
+
+// Controller for sleep with backoff when the client attempts reconnection
+// It has statuses for each situations cause reconnection.
+type backoffController struct {
+	sync.RWMutex
+	statusMap map[string]*backoffStatus
+}
+
+type backoffStatus struct {
+	lastSleepPeriod time.Duration
+	lastErrorTime   time.Time
+}
+
+func newBackoffController() *backoffController {
+	return &backoffController{
+		statusMap: map[string]*backoffStatus{},
+	}
+}
+
+// Calculate next sleep period from the specified parameters.
+// Returned values are next sleep period and whether the error situation is continual.
+// If connection errors continuouslly occurs, its sleep period is exponentially increased.
+// Also if there is a lot of time between last and this error, sleep period is initialized.
+func (b *backoffController) getBackoffSleepTime(
+	situation string, initSleepPeriod time.Duration, maxSleepPeriod time.Duration, processTime time.Duration, skipFirst bool,
+) (time.Duration, bool) {
+	// Decide first sleep time if the situation is not continual. 
+	var firstProcess = func(status *backoffStatus, init time.Duration, skip bool) (time.Duration, bool) {
+		if skip {
+			status.lastSleepPeriod = 0
+			return 0, false
+		}
+		status.lastSleepPeriod = init
+		return init, false
+	}
+
+	// Prioritize maxSleep.
+	if initSleepPeriod > maxSleepPeriod {
+		initSleepPeriod = maxSleepPeriod
+	}
+	b.Lock()
+	defer b.Unlock()
+
+	status, exist := b.statusMap[situation]
+	if !exist {
+		b.statusMap[situation] = &backoffStatus{initSleepPeriod, time.Now()}
+		return firstProcess(b.statusMap[situation], initSleepPeriod, skipFirst)
+	}
+
+	oldTime := status.lastErrorTime
+	status.lastErrorTime = time.Now()
+
+	// When there is a lot of time between last and this error, sleep period is initialized.
+	if status.lastErrorTime.Sub(oldTime) > (processTime * 2 + status.lastSleepPeriod) {
+		return firstProcess(status, initSleepPeriod, skipFirst)
+	}
+
+	if status.lastSleepPeriod == 0 {
+		status.lastSleepPeriod = initSleepPeriod
+		return initSleepPeriod, true
+	}
+
+	if nextSleepPeriod := status.lastSleepPeriod * 2; nextSleepPeriod <= maxSleepPeriod {
+		status.lastSleepPeriod = nextSleepPeriod
+	} else {
+		status.lastSleepPeriod = maxSleepPeriod
+	}
+
+	return status.lastSleepPeriod, true
+}
+
+// Execute sleep the time returned from getBackoffSleepTime.
+func (b *backoffController) sleepWithBackoff(
+	situation string, initSleepPeriod time.Duration, maxSleepPeriod time.Duration, processTime time.Duration, skipFirst bool,
+) (time.Duration, bool) {
+	sleep, isFirst := b.getBackoffSleepTime(situation, initSleepPeriod, maxSleepPeriod, processTime, skipFirst)
+	if sleep != 0 {
+		time.Sleep(sleep)
+	}
+	return sleep, isFirst
+}

vendor/github.com/eclipse/paho.mqtt.golang/client.go

@@ -141,6 +141,8 @@ type client struct {
 	stop         chan struct{}  // Closed to request that workers stop
 	workers      sync.WaitGroup // used to wait for workers to complete (ping, keepalive, errwatch, resume)
 	commsStopped chan struct{}  // closed when the comms routines have stopped (kept running until after workers have closed to avoid deadlocks)
+
+	backoff      *backoffController
 }
 
 // NewClient will create an MQTT v3.1.1 client with all of the options specified
@@ -169,6 +171,7 @@ func NewClient(o *ClientOptions) Client {
 	c.msgRouter.setDefaultHandler(c.options.DefaultPublishHandler)
 	c.obound = make(chan *PacketAndToken)
 	c.oboundP = make(chan *PacketAndToken)
+	c.backoff = newBackoffController()
 	return c
 }
 
@@ -302,10 +305,16 @@ func (c *client) Connect() Token {
 func (c *client) reconnect(connectionUp connCompletedFn) {
 	DEBUG.Println(CLI, "enter reconnect")
 	var (
-		sleep = 1 * time.Second
+		initSleep = 1 * time.Second
 		conn  net.Conn
 	)
 
+	// If the reason of connection lost is same as the before one, sleep timer is set before attempting connection is started.
+	// Sleep time is exponentially increased as the same situation continues
+	if slp, isContinual := c.backoff.sleepWithBackoff("connectionLost", initSleep, c.options.MaxReconnectInterval, 3 * time.Second, true); isContinual {
+		DEBUG.Println(CLI, "Detect continual connection lost after reconnect, slept for", int(slp.Seconds()), "seconds")
+	}
+
 	for {
 		if nil != c.options.OnReconnecting {
 			c.options.OnReconnecting(c, &c.options)
@@ -315,15 +324,8 @@ func (c *client) reconnect(connectionUp connCompletedFn) {
 		if err == nil {
 			break
 		}
-		DEBUG.Println(CLI, "Reconnect failed, sleeping for", int(sleep.Seconds()), "seconds:", err)
-		time.Sleep(sleep)
-		if sleep < c.options.MaxReconnectInterval {
-			sleep *= 2
-		}
-
-		if sleep > c.options.MaxReconnectInterval {
-			sleep = c.options.MaxReconnectInterval
-		}
+		sleep, _ := c.backoff.sleepWithBackoff("attemptReconnection", initSleep, c.options.MaxReconnectInterval, c.options.ConnectTimeout, false)
+		DEBUG.Println(CLI, "Reconnect failed, slept for", int(sleep.Seconds()), "seconds:", err)
 
 		if c.status.ConnectionStatus() != reconnecting { // Disconnect may have been called
 			if err := connectionUp(false); err != nil { // Should always return an error

vendor/github.com/eclipse/paho.mqtt.golang/netconn.go

@@ -40,10 +40,14 @@ import (
 func openConnection(uri *url.URL, tlsc *tls.Config, timeout time.Duration, headers http.Header, websocketOptions *WebsocketOptions, dialer *net.Dialer) (net.Conn, error) {
 	switch uri.Scheme {
 	case "ws":
-		conn, err := NewWebsocket(uri.String(), nil, timeout, headers, websocketOptions)
+		dialURI := *uri // #623 - Gorilla Websockets does not accept URL's where uri.User != nil
+		dialURI.User = nil
+		conn, err := NewWebsocket(dialURI.String(), nil, timeout, headers, websocketOptions)
 		return conn, err
 	case "wss":
-		conn, err := NewWebsocket(uri.String(), tlsc, timeout, headers, websocketOptions)
+		dialURI := *uri // #623 - Gorilla Websockets does not accept URL's where uri.User != nil
+		dialURI.User = nil
+		conn, err := NewWebsocket(dialURI.String(), tlsc, timeout, headers, websocketOptions)
 		return conn, err
 	case "mqtt", "tcp":
 		allProxy := os.Getenv("all_proxy")

vendor/github.com/eclipse/paho.mqtt.golang/ping.go

@@ -32,16 +32,16 @@ import (
 func keepalive(c *client, conn io.Writer) {
 	defer c.workers.Done()
 	DEBUG.Println(PNG, "keepalive starting")
-	var checkInterval int64
+	var checkInterval time.Duration
 	var pingSent time.Time
 
 	if c.options.KeepAlive > 10 {
-		checkInterval = 5
+		checkInterval = 5 * time.Second
 	} else {
-		checkInterval = c.options.KeepAlive / 2
+		checkInterval = time.Duration(c.options.KeepAlive) * time.Second / 2
 	}
 
-	intervalTicker := time.NewTicker(time.Duration(checkInterval * int64(time.Second)))
+	intervalTicker := time.NewTicker(checkInterval)
 	defer intervalTicker.Stop()
 
 	for {