fix #581

irc/channelmanager.go

@@ -13,36 +13,54 @@ type channelManagerEntry struct {
 	// think the channel is empty (without holding a lock across the entire Channel.Join()
 	// call)
 	pendingJoins int
+	skeleton     string
 }
 
 // ChannelManager keeps track of all the channels on the server,
 // providing synchronization for creation of new channels on first join,
 // cleanup of empty channels on last part, and renames.
 type ChannelManager struct {
-	sync.RWMutex       // tier 2
-	chans              map[string]*channelManagerEntry
-	registeredChannels map[string]bool
-	purgedChannels     map[string]empty
-	server             *Server
+	sync.RWMutex // tier 2
+	// chans is the main data structure, mapping casefolded name -> *Channel
+	chans               map[string]*channelManagerEntry
+	chansSkeletons      StringSet // skeletons of *unregistered* chans
+	registeredChannels  StringSet // casefolds of registered chans
+	registeredSkeletons StringSet // skeletons of registered chans
+	purgedChannels      StringSet // casefolds of purged chans
+	server              *Server
 }
 
 // NewChannelManager returns a new ChannelManager.
 func (cm *ChannelManager) Initialize(server *Server) {
 	cm.chans = make(map[string]*channelManagerEntry)
+	cm.chansSkeletons = make(StringSet)
 	cm.server = server
 
 	if server.Config().Channels.Registration.Enabled {
 		cm.loadRegisteredChannels()
 	}
+	// purging should work even if registration is disabled
+	cm.purgedChannels = cm.server.channelRegistry.PurgedChannels()
 }
 
 func (cm *ChannelManager) loadRegisteredChannels() {
-	registeredChannels := cm.server.channelRegistry.AllChannels()
-	purgedChannels := cm.server.channelRegistry.PurgedChannels()
+	rawNames := cm.server.channelRegistry.AllChannels()
+	registeredChannels := make(StringSet, len(rawNames))
+	registeredSkeletons := make(StringSet, len(rawNames))
+	for _, name := range rawNames {
+		cfname, err := CasefoldChannel(name)
+		if err == nil {
+			registeredChannels.Add(cfname)
+		}
+		skeleton, err := Skeleton(name)
+		if err == nil {
+			registeredSkeletons.Add(skeleton)
+		}
+	}
 	cm.Lock()
 	defer cm.Unlock()
 	cm.registeredChannels = registeredChannels
-	cm.purgedChannels = purgedChannels
+	cm.registeredSkeletons = registeredSkeletons
 }
 
 // Get returns an existing channel with name equivalent to `name`, or nil
@@ -64,37 +82,49 @@ func (cm *ChannelManager) Get(name string) (channel *Channel) {
 func (cm *ChannelManager) Join(client *Client, name string, key string, isSajoin bool, rb *ResponseBuffer) error {
 	server := client.server
 	casefoldedName, err := CasefoldChannel(name)
-	if err != nil || len(casefoldedName) > server.Config().Limits.ChannelLen {
+	skeleton, skerr := Skeleton(name)
+	if err != nil || skerr != nil || len(casefoldedName) > server.Config().Limits.ChannelLen {
 		return errNoSuchChannel
 	}
 
-	channel := func() *Channel {
+	channel, err := func() (*Channel, error) {
 		cm.Lock()
 		defer cm.Unlock()
 
-		_, purged := cm.purgedChannels[casefoldedName]
-		if purged {
-			return nil
+		if cm.purgedChannels.Has(casefoldedName) {
+			return nil, errChannelPurged
 		}
 		entry := cm.chans[casefoldedName]
 		if entry == nil {
-			registered := cm.registeredChannels[casefoldedName]
+			registered := cm.registeredChannels.Has(casefoldedName)
 			// enforce OpOnlyCreation
 			if !registered && server.Config().Channels.OpOnlyCreation && !client.HasRoleCapabs("chanreg") {
-				return nil
+				return nil, errInsufficientPrivs
+			}
+			// enforce confusables
+			if cm.chansSkeletons.Has(skeleton) || (!registered && cm.registeredSkeletons.Has(skeleton)) {
+				return nil, errConfusableIdentifier
 			}
 			entry = &channelManagerEntry{
-				channel:      NewChannel(server, name, registered),
+				channel:      NewChannel(server, name, casefoldedName, registered),
 				pendingJoins: 0,
 			}
+			if !registered {
+				// for an unregistered channel, we already have the correct unfolded name
+				// and therefore the final skeleton. for a registered channel, we don't have
+				// the unfolded name yet (it needs to be loaded from the db), but we already
+				// have the final skeleton in `registeredSkeletons` so we don't need to track it
+				cm.chansSkeletons.Add(skeleton)
+				entry.skeleton = skeleton
+			}
 			cm.chans[casefoldedName] = entry
 		}
 		entry.pendingJoins += 1
-		return entry.channel
+		return entry.channel, nil
 	}()
 
-	if channel == nil {
-		return errNoSuchChannel
+	if err != nil {
+		return err
 	}
 
 	channel.EnsureLoaded()
@@ -109,8 +139,9 @@ func (cm *ChannelManager) maybeCleanup(channel *Channel, afterJoin bool) {
 	cm.Lock()
 	defer cm.Unlock()
 
-	nameCasefolded := channel.NameCasefolded()
-	entry := cm.chans[nameCasefolded]
+	cfname := channel.NameCasefolded()
+
+	entry := cm.chans[cfname]
 	if entry == nil || entry.channel != channel {
 		return
 	}
@@ -119,7 +150,10 @@ func (cm *ChannelManager) maybeCleanup(channel *Channel, afterJoin bool) {
 		entry.pendingJoins -= 1
 	}
 	if entry.pendingJoins == 0 && entry.channel.IsClean() {
-		delete(cm.chans, nameCasefolded)
+		delete(cm.chans, cfname)
+		if entry.skeleton != "" {
+			delete(cm.chansSkeletons, entry.skeleton)
+		}
 	}
 }
 
@@ -177,7 +211,7 @@ func (cm *ChannelManager) SetRegistered(channelName string, account string) (err
 	if err != nil {
 		return err
 	}
-	cm.registeredChannels[cfname] = true
+	cm.registeredChannels.Add(cfname)
 	return nil
 }
 
@@ -211,13 +245,17 @@ func (cm *ChannelManager) SetUnregistered(channelName string, account string) (e
 }
 
 // Rename renames a channel (but does not notify the members)
-func (cm *ChannelManager) Rename(name string, newname string) (err error) {
+func (cm *ChannelManager) Rename(name string, newName string) (err error) {
 	cfname, err := CasefoldChannel(name)
 	if err != nil {
 		return errNoSuchChannel
 	}
 
-	cfnewname, err := CasefoldChannel(newname)
+	newCfname, err := CasefoldChannel(newName)
+	if err != nil {
+		return errInvalidChannelName
+	}
+	newSkeleton, err := Skeleton(newName)
 	if err != nil {
 		return errInvalidChannelName
 	}
@@ -236,22 +274,35 @@ func (cm *ChannelManager) Rename(name string, newname string) (err error) {
 	cm.Lock()
 	defer cm.Unlock()
 
-	if cm.chans[cfnewname] != nil || cm.registeredChannels[cfnewname] {
+	if cm.chans[newCfname] != nil || cm.registeredChannels.Has(newCfname) {
+		return errChannelNameInUse
+	}
+	if cm.chansSkeletons.Has(newSkeleton) || cm.registeredSkeletons.Has(newSkeleton) {
 		return errChannelNameInUse
 	}
 	entry := cm.chans[cfname]
-	if entry == nil {
+	if entry == nil || !entry.channel.IsLoaded() {
 		return errNoSuchChannel
 	}
 	channel = entry.channel
 	info = channel.ExportRegistration(IncludeInitial)
+	registered := info.Founder != ""
 	delete(cm.chans, cfname)
-	cm.chans[cfnewname] = entry
-	if cm.registeredChannels[cfname] {
+	cm.chans[newCfname] = entry
+	if registered {
 		delete(cm.registeredChannels, cfname)
-		cm.registeredChannels[cfnewname] = true
+		if oldSkeleton, err := Skeleton(info.Name); err == nil {
+			delete(cm.registeredSkeletons, oldSkeleton)
+		}
+		cm.registeredChannels.Add(newCfname)
+		cm.registeredSkeletons.Add(newSkeleton)
+	} else {
+		delete(cm.chansSkeletons, entry.skeleton)
+		cm.chansSkeletons.Add(newSkeleton)
+		entry.skeleton = newSkeleton
+		cm.chans[cfname] = entry
 	}
-	entry.channel.Rename(newname, cfnewname)
+	entry.channel.Rename(newName, newCfname)
 	return nil
 }
 
@@ -283,7 +334,7 @@ func (cm *ChannelManager) Purge(chname string, record ChannelPurgeRecord) (err e
 	}
 
 	cm.Lock()
-	cm.purgedChannels[chname] = empty{}
+	cm.purgedChannels.Add(chname)
 	cm.Unlock()
 
 	cm.server.channelRegistry.PurgeChannel(chname, record)
@@ -298,7 +349,7 @@ func (cm *ChannelManager) IsPurged(chname string) (result bool) {
 	}
 
 	cm.Lock()
-	_, result = cm.purgedChannels[chname]
+	result = cm.purgedChannels.Has(chname)
 	cm.Unlock()
 	return
 }
@@ -311,7 +362,7 @@ func (cm *ChannelManager) Unpurge(chname string) (err error) {
 	}
 
 	cm.Lock()
-	_, found := cm.purgedChannels[chname]
+	found := cm.purgedChannels.Has(chname)
 	delete(cm.purgedChannels, chname)
 	cm.Unlock()