Implement expiration for always-on clients

Fixes #810

default.yaml

         # whether to mark always-on clients away when they have no active connections:
         auto-away: "opt-in"
 
+        # QUIT always-on clients from the server if they go this long without connecting
+        # (use 0 or omit for no expiration):
+        #always-on-expiration: 90d
+
     # vhosts controls the assignment of vhosts (strings displayed in place of the user's
     # hostname/IP) by the HostServ service
     vhosts:

irc/client.go

 }
 
 // sets the session quit message, if there isn't one already
-func (sd *Session) SetQuitMessage(message string) (set bool) {
+func (sd *Session) setQuitMessage(message string) (set bool) {
 	if message == "" {
 		message = "Connection closed"
 	}
 		nextSessionID: 1,
 	}
 
+	if client.checkAlwaysOnExpirationNoMutex(config) {
+		server.logger.Debug("accounts", "always-on client not created due to expiration", account.Name)
+		return
+	}
+
 	client.SetMode(modes.TLS, true)
 	for _, m := range uModes {
 		client.SetMode(m, true)
 	var markDirty bool
 	now := time.Now().UTC()
 	client.stateMutex.Lock()
-	if client.accountSettings.AutoreplayMissed || session.deviceID != "" {
-		client.setLastSeen(now, session.deviceID)
-		if now.Sub(client.lastSeenLastWrite) > lastSeenWriteInterval {
-			markDirty = true
-			client.lastSeenLastWrite = now
+	if client.registered {
+		client.updateIdleTimer(session, now)
+		if client.alwaysOn {
+			client.setLastSeen(now, session.deviceID)
+			if now.Sub(client.lastSeenLastWrite) > lastSeenWriteInterval {
+				markDirty = true
+				client.lastSeenLastWrite = now
+			}
 		}
 	}
-	client.updateIdleTimer(session, now)
 	client.stateMutex.Unlock()
 	if markDirty {
 		client.markDirty(IncludeLastSeen)
 	}
 
 	for _, session := range sessions {
-		if session.SetQuitMessage(message) {
+		if session.setQuitMessage(message) {
 			setFinalData(session)
 		}
 	}
 	config := client.server.Config()
 	var sessionsToDestroy []*Session
 	var saveLastSeen bool
+	var quitMessage string
 
 	client.stateMutex.Lock()
 
 	// XXX a temporary (reattaching) client can be marked alwaysOn when it logs in,
 	// but then the session attaches to another client and we need to clean it up here
 	alwaysOn := registered && client.alwaysOn
+	// if we hit always-on-expiration, confirm the expiration and then proceed as though
+	// always-on is disabled:
+	if alwaysOn && session == nil && client.checkAlwaysOnExpirationNoMutex(config) {
+		quitMessage = "Timed out due to inactivity"
+		alwaysOn = false
+		client.alwaysOn = false
+	}
 
 	var remainingSessions int
 	if session == nil {
 	}
 
 	// destroy all applicable sessions:
-	var quitMessage string
 	for _, session := range sessionsToDestroy {
 		if session.client != client {
 			// session has been attached to a new client; do not destroy it
 		session.stopIdleTimer()
 		// send quit/error message to client if they haven't been sent already
 		client.Quit("", session)
-		quitMessage = session.quitMessage
+		quitMessage = session.quitMessage // doesn't need synch, we already detached
 		session.SetDestroyed()
 		session.socket.Close()
 
 		return
 	}
 
-	splitQuitMessage := utils.MakeMessage(quitMessage)
-	quitItem := history.Item{
-		Type:        history.Quit,
-		Nick:        details.nickMask,
-		AccountName: details.accountName,
-		Message:     splitQuitMessage,
-	}
+	var quitItem history.Item
 	var channels []*Channel
 	// use a defer here to avoid writing to mysql while holding the destroy semaphore:
 	defer func() {
 	if quitMessage == "" {
 		quitMessage = "Exited"
 	}
+	splitQuitMessage := utils.MakeMessage(quitMessage)
+	quitItem = history.Item{
+		Type:        history.Quit,
+		Nick:        details.nickMask,
+		AccountName: details.accountName,
+		Message:     splitQuitMessage,
+	}
 	var cache MessageCache
 	cache.Initialize(client.server, splitQuitMessage.Time, splitQuitMessage.Msgid, details.nickMask, details.accountName, nil, "QUIT", quitMessage)
 	for friend := range friends {

irc/config.go

 }
 
 type MulticlientConfig struct {
-	Enabled          bool
-	AllowedByDefault bool             `yaml:"allowed-by-default"`
-	AlwaysOn         PersistentStatus `yaml:"always-on"`
-	AutoAway         PersistentStatus `yaml:"auto-away"`
+	Enabled            bool
+	AllowedByDefault   bool             `yaml:"allowed-by-default"`
+	AlwaysOn           PersistentStatus `yaml:"always-on"`
+	AutoAway           PersistentStatus `yaml:"auto-away"`
+	AlwaysOnExpiration custime.Duration `yaml:"always-on-expiration"`
 }
 
 type throttleConfig struct {

irc/getters.go

 
 func (client *Client) SetAccountSettings(settings AccountSettings) {
 	// we mark dirty if the client is transitioning to always-on
-	var becameAlwaysOn, autoreplayMissedDisabled bool
+	var becameAlwaysOn bool
 	alwaysOn := persistenceEnabled(client.server.Config().Accounts.Multiclient.AlwaysOn, settings.AlwaysOn)
 	client.stateMutex.Lock()
 	if client.registered {
 		// only allow the client to become always-on if their nick equals their account name
 		alwaysOn = alwaysOn && client.nick == client.accountName
-		autoreplayMissedDisabled = (client.accountSettings.AutoreplayMissed && !settings.AutoreplayMissed)
 		becameAlwaysOn = (!client.alwaysOn && alwaysOn)
 		client.alwaysOn = alwaysOn
-		if autoreplayMissedDisabled {
-			// clear the lastSeen entry for the default session, but not for device IDs
-			delete(client.lastSeen, "")
-		}
 	}
 	client.accountSettings = settings
 	client.stateMutex.Unlock()
 	if becameAlwaysOn {
 		client.markDirty(IncludeAllAttrs)
-	} else if autoreplayMissedDisabled {
-		client.markDirty(IncludeLastSeen)
 	}
 }
 
 	return result
 }
 
+func (client *Client) IsExpiredAlwaysOn(config *Config) (result bool) {
+	client.stateMutex.Lock()
+	defer client.stateMutex.Unlock()
+	return client.checkAlwaysOnExpirationNoMutex(config)
+}
+
+func (client *Client) checkAlwaysOnExpirationNoMutex(config *Config) (result bool) {
+	if !(client.registered && client.alwaysOn) {
+		return false
+	}
+	deadline := time.Duration(config.Accounts.Multiclient.AlwaysOnExpiration)
+	if deadline == 0 {
+		return false
+	}
+	now := time.Now()
+	for _, ts := range client.lastSeen {
+		if now.Sub(ts) < deadline {
+			return false
+		}
+	}
+	return true
+}
+
 func (channel *Channel) Name() string {
 	channel.stateMutex.RLock()
 	defer channel.stateMutex.RUnlock()

irc/server.go

 	_ "net/http/pprof"
 	"os"
 	"os/signal"
+	"runtime/debug"
 	"strconv"
 	"strings"
 	"sync"
 	"github.com/tidwall/buntdb"
 )
 
+const (
+	alwaysOnExpirationPollPeriod = time.Hour
+)
+
 var (
 	// common error line to sub values into
 	errorMsg = "ERROR :%s\r\n"
 	signal.Notify(server.signals, ServerExitSignals...)
 	signal.Notify(server.rehashSignal, syscall.SIGHUP)
 
+	time.AfterFunc(alwaysOnExpirationPollPeriod, server.handleAlwaysOnExpirations)
+
 	return server, nil
 }
 
 	}
 }
 
+func (server *Server) handleAlwaysOnExpirations() {
+	defer func() {
+		if r := recover(); r != nil {
+			server.logger.Error("internal",
+				fmt.Sprintf("Panic in always-on cleanup: %v\n%s", r, debug.Stack()))
+		}
+		// either way, reschedule
+		time.AfterFunc(alwaysOnExpirationPollPeriod, server.handleAlwaysOnExpirations)
+	}()
+
+	config := server.Config()
+	deadline := time.Duration(config.Accounts.Multiclient.AlwaysOnExpiration)
+	if deadline == 0 {
+		return
+	}
+	server.logger.Info("accounts", "Checking always-on clients for expiration")
+	for _, client := range server.clients.AllClients() {
+		if client.IsExpiredAlwaysOn(config) {
+			// TODO save the channels list, use it for autojoin if/when they return?
+			server.logger.Info("accounts", "Expiring always-on client", client.AccountName())
+			client.destroy(nil)
+		}
+	}
+}
+
 //
 // server functionality
 //

traditional.yaml

         # whether to mark always-on clients away when they have no active connections:
         auto-away: "opt-in"
 
+        # QUIT always-on clients from the server if they go this long without connecting
+        # (use 0 or omit for no expiration):
+        #always-on-expiration: 90d
+
     # vhosts controls the assignment of vhosts (strings displayed in place of the user's
     # hostname/IP) by the HostServ service
     vhosts: