chanserv enhancements and miscellaneous fixes

* Fix #684
* Fix #683
* Add `CHANSERV CLEAR`
* Allow mode changes from channel founders even when they aren't joined
* Operators with the chanreg capability are exempt from max-channels-per-account
* Small fixes and cleanup

irc/accounts.go

@@ -490,7 +490,7 @@ func (am *AccountManager) dispatchMailtoCallback(client *Client, casefoldedAccou
 		fmt.Sprintf(client.t("Account: %s"), casefoldedAccount) + "\r\n",
 		fmt.Sprintf(client.t("Verification code: %s"), code) + "\r\n",
 		"\r\n",
-		client.t("To verify your account, issue one of these commands:") + "\r\n",
+		client.t("To verify your account, issue the following command:") + "\r\n",
 		fmt.Sprintf("/MSG NickServ VERIFY %s %s", casefoldedAccount, code) + "\r\n",
 	}
 

irc/channel.go

@@ -37,6 +37,7 @@ type Channel struct {
 	createdTime       time.Time
 	registeredFounder string
 	registeredTime    time.Time
+	transferPendingTo string
 	topic             string
 	topicSetBy        string
 	topicSetTime      time.Time
@@ -59,22 +60,17 @@ func NewChannel(s *Server, name string, registered bool) *Channel {
 		return nil
 	}
 
+	config := s.Config()
+
 	channel := &Channel{
 		createdTime:    time.Now().UTC(), // may be overwritten by applyRegInfo
-		lists: map[modes.Mode]*UserMaskSet{
-			modes.BanMask:    NewUserMaskSet(),
-			modes.ExceptMask: NewUserMaskSet(),
-			modes.InviteMask: NewUserMaskSet(),
-		},
 		members:        make(MemberSet),
 		name:           name,
 		nameCasefolded: casefoldedName,
 		server:         s,
-		accountToUMode: make(map[string]modes.Mode),
 	}
 
-	config := s.Config()
+	channel.initializeLists()
-
 	channel.writerSemaphore.Initialize(1)
 	channel.history.Initialize(config.History.ChannelLength, config.History.AutoresizeWindow)
 
@@ -89,6 +85,15 @@ func NewChannel(s *Server, name string, registered bool) *Channel {
 	return channel
 }
 
+func (channel *Channel) initializeLists() {
+	channel.lists = map[modes.Mode]*UserMaskSet{
+		modes.BanMask:    NewUserMaskSet(),
+		modes.ExceptMask: NewUserMaskSet(),
+		modes.InviteMask: NewUserMaskSet(),
+	}
+	channel.accountToUMode = make(map[string]modes.Mode)
+}
+
 // EnsureLoaded blocks until the channel's registration info has been loaded
 // from the database.
 func (channel *Channel) EnsureLoaded() {
@@ -303,6 +308,18 @@ func (channel *Channel) SetUnregistered(expectedFounder string) {
 	channel.accountToUMode = make(map[string]modes.Mode)
 }
 
+// implements `CHANSERV CLEAR #chan ACCESS` (resets bans, invites, excepts, and amodes)
+func (channel *Channel) resetAccess() {
+	defer channel.MarkDirty(IncludeLists)
+
+	channel.stateMutex.Lock()
+	defer channel.stateMutex.Unlock()
+	channel.initializeLists()
+	if channel.registeredFounder != "" {
+		channel.accountToUMode[channel.registeredFounder] = modes.ChannelFounder
+	}
+}
+
 // IsRegistered returns whether the channel is registered.
 func (channel *Channel) IsRegistered() bool {
 	channel.stateMutex.RLock()
@@ -310,6 +327,78 @@ func (channel *Channel) IsRegistered() bool {
 	return channel.registeredFounder != ""
 }
 
+type channelTransferStatus uint
+
+const (
+	channelTransferComplete channelTransferStatus = iota
+	channelTransferPending
+	channelTransferCancelled
+	channelTransferFailed
+)
+
+// Transfer transfers ownership of a registered channel to a different account
+func (channel *Channel) Transfer(client *Client, target string, hasPrivs bool) (status channelTransferStatus, err error) {
+	status = channelTransferFailed
+	defer func() {
+		if status == channelTransferComplete && err == nil {
+			channel.Store(IncludeAllChannelAttrs)
+		}
+	}()
+
+	cftarget, err := CasefoldName(target)
+	if err != nil {
+		err = errAccountDoesNotExist
+		return
+	}
+	channel.stateMutex.Lock()
+	defer channel.stateMutex.Unlock()
+	if channel.registeredFounder == "" {
+		err = errChannelNotOwnedByAccount
+		return
+	}
+	if hasPrivs {
+		channel.transferOwnership(cftarget)
+		return channelTransferComplete, nil
+	} else {
+		if channel.registeredFounder == cftarget {
+			// transferring back to yourself cancels a pending transfer
+			channel.transferPendingTo = ""
+			return channelTransferCancelled, nil
+		} else {
+			channel.transferPendingTo = cftarget
+			return channelTransferPending, nil
+		}
+	}
+}
+
+func (channel *Channel) transferOwnership(newOwner string) {
+	delete(channel.accountToUMode, channel.registeredFounder)
+	channel.registeredFounder = newOwner
+	channel.accountToUMode[channel.registeredFounder] = modes.ChannelFounder
+	channel.transferPendingTo = ""
+}
+
+// AcceptTransfer implements `CS TRANSFER #chan ACCEPT`
+func (channel *Channel) AcceptTransfer(client *Client) (err error) {
+	defer func() {
+		if err == nil {
+			channel.Store(IncludeAllChannelAttrs)
+		}
+	}()
+
+	account := client.Account()
+	if account == "" {
+		return errAccountNotLoggedIn
+	}
+	channel.stateMutex.Lock()
+	defer channel.stateMutex.Unlock()
+	if account != channel.transferPendingTo {
+		return errChannelTransferNotOffered
+	}
+	channel.transferOwnership(account)
+	return nil
+}
+
 func (channel *Channel) regenerateMembersCache() {
 	channel.stateMutex.RLock()
 	result := make([]*Client, len(channel.members))
@@ -1117,21 +1206,23 @@ func (channel *Channel) Quit(client *Client) {
 	client.removeChannel(channel)
 }
 
-func (channel *Channel) Kick(client *Client, target *Client, comment string, rb *ResponseBuffer) {
+func (channel *Channel) Kick(client *Client, target *Client, comment string, rb *ResponseBuffer, hasPrivs bool) {
+	if !hasPrivs {
 		if !(client.HasMode(modes.Operator) || channel.hasClient(client)) {
 			rb.Add(nil, client.server.name, ERR_NOTONCHANNEL, client.Nick(), channel.Name(), client.t("You're not on that channel"))
 			return
 		}
-	if !channel.hasClient(target) {
-		rb.Add(nil, client.server.name, ERR_USERNOTINCHANNEL, client.Nick(), channel.Name(), client.t("They aren't on that channel"))
-		return
-	}
 		if !channel.ClientHasPrivsOver(client, target) {
 			rb.Add(nil, client.server.name, ERR_CHANOPRIVSNEEDED, client.Nick(), channel.Name(), client.t("You don't have enough channel privileges"))
 			return
 		}
+	}
+	if !channel.hasClient(target) {
+		rb.Add(nil, client.server.name, ERR_USERNOTINCHANNEL, client.Nick(), channel.Name(), client.t("They aren't on that channel"))
+		return
+	}
 
-	kicklimit := client.server.Config().Limits.KickLen
+	kicklimit := channel.server.Config().Limits.KickLen
 	if len(comment) > kicklimit {
 		comment = comment[:kicklimit]
 	}

irc/channelmanager.go

@@ -22,6 +22,7 @@ type ChannelManager struct {
 	sync.RWMutex       // tier 2
 	chans              map[string]*channelManagerEntry
 	registeredChannels map[string]bool
+	purgedChannels     map[string]empty
 	server             *Server
 }
 
@@ -37,9 +38,11 @@ func (cm *ChannelManager) Initialize(server *Server) {
 
 func (cm *ChannelManager) loadRegisteredChannels() {
 	registeredChannels := cm.server.channelRegistry.AllChannels()
+	purgedChannels := cm.server.channelRegistry.PurgedChannels()
 	cm.Lock()
 	defer cm.Unlock()
 	cm.registeredChannels = registeredChannels
+	cm.purgedChannels = purgedChannels
 }
 
 // Get returns an existing channel with name equivalent to `name`, or nil
@@ -69,6 +72,10 @@ func (cm *ChannelManager) Join(client *Client, name string, key string, isSajoin
 		cm.Lock()
 		defer cm.Unlock()
 
+		_, purged := cm.purgedChannels[casefoldedName]
+		if purged {
+			return nil
+		}
 		entry := cm.chans[casefoldedName]
 		if entry == nil {
 			registered := cm.registeredChannels[casefoldedName]
@@ -267,3 +274,50 @@ func (cm *ChannelManager) Channels() (result []*Channel) {
 	}
 	return
 }
+
+// Purge marks a channel as purged.
+func (cm *ChannelManager) Purge(chname string, record ChannelPurgeRecord) (err error) {
+	chname, err = CasefoldChannel(chname)
+	if err != nil {
+		return errInvalidChannelName
+	}
+
+	cm.Lock()
+	cm.purgedChannels[chname] = empty{}
+	cm.Unlock()
+
+	cm.server.channelRegistry.PurgeChannel(chname, record)
+	return nil
+}
+
+// IsPurged queries whether a channel is purged.
+func (cm *ChannelManager) IsPurged(chname string) (result bool) {
+	chname, err := CasefoldChannel(chname)
+	if err != nil {
+		return false
+	}
+
+	cm.Lock()
+	_, result = cm.purgedChannels[chname]
+	cm.Unlock()
+	return
+}
+
+// Unpurge deletes a channel's purged status.
+func (cm *ChannelManager) Unpurge(chname string) (err error) {
+	chname, err = CasefoldChannel(chname)
+	if err != nil {
+		return errNoSuchChannel
+	}
+
+	cm.Lock()
+	_, found := cm.purgedChannels[chname]
+	delete(cm.purgedChannels, chname)
+	cm.Unlock()
+
+	cm.server.channelRegistry.UnpurgeChannel(chname)
+	if !found {
+		return errNoSuchChannel
+	}
+	return nil
+}

irc/channelreg.go

@@ -32,6 +32,8 @@ const (
 	keyChannelPassword       = "channel.key %s"
 	keyChannelModes          = "channel.modes %s"
 	keyChannelAccountToUMode = "channel.accounttoumode %s"
+
+	keyChannelPurged = "channel.purged %s"
 )
 
 var (
@@ -96,6 +98,12 @@ type RegisteredChannel struct {
 	Invites map[string]MaskInfo
 }
 
+type ChannelPurgeRecord struct {
+	Oper     string
+	PurgedAt time.Time
+	Reason   string
+}
+
 // ChannelRegistry manages registered channels.
 type ChannelRegistry struct {
 	server *Server
@@ -124,6 +132,24 @@ func (reg *ChannelRegistry) AllChannels() (result map[string]bool) {
 	return
 }
 
+// PurgedChannels returns the set of all channel names that have been purged
+func (reg *ChannelRegistry) PurgedChannels() (result map[string]empty) {
+	result = make(map[string]empty)
+
+	prefix := fmt.Sprintf(keyChannelPurged, "")
+	reg.server.store.View(func(tx *buntdb.Tx) error {
+		return tx.AscendGreaterOrEqual("", prefix, func(key, value string) bool {
+			if !strings.HasPrefix(key, prefix) {
+				return false
+			}
+			channel := strings.TrimPrefix(key, prefix)
+			result[channel] = empty{}
+			return true
+		})
+	})
+	return
+}
+
 // StoreChannel obtains a consistent view of a channel, then persists it to the store.
 func (reg *ChannelRegistry) StoreChannel(info RegisteredChannel, includeFlags uint) (err error) {
 	if !reg.server.ChannelRegistrationEnabled() {
@@ -191,11 +217,11 @@ func (reg *ChannelRegistry) LoadChannel(nameCasefolded string) (info RegisteredC
 
 		info = RegisteredChannel{
 			Name:           name,
-			RegisteredAt:   time.Unix(regTimeInt, 0),
+			RegisteredAt:   time.Unix(regTimeInt, 0).UTC(),
 			Founder:        founder,
 			Topic:          topic,
 			TopicSetBy:     topicSetBy,
-			TopicSetTime:   time.Unix(topicSetTimeInt, 0),
+			TopicSetTime:   time.Unix(topicSetTimeInt, 0).UTC(),
 			Key:            password,
 			Modes:          modeSlice,
 			Bans:           banlist,
@@ -256,14 +282,12 @@ func (reg *ChannelRegistry) deleteChannel(tx *buntdb.Tx, key string, info Regist
 	}
 }
 
-// saveChannel saves a channel to the store.
+func (reg *ChannelRegistry) updateAccountToChannelMapping(tx *buntdb.Tx, channelInfo RegisteredChannel) {
-func (reg *ChannelRegistry) saveChannel(tx *buntdb.Tx, channelInfo RegisteredChannel, includeFlags uint) {
 	channelKey := channelInfo.NameCasefolded
-	// maintain the mapping of account -> registered channels
+	chanFounderKey := fmt.Sprintf(keyChannelFounder, channelKey)
-	chanExistsKey := fmt.Sprintf(keyChannelExists, channelKey)
+	founder, existsErr := tx.Get(chanFounderKey)
-	_, existsErr := tx.Get(chanExistsKey)
+	if existsErr == buntdb.ErrNotFound || founder != channelInfo.Founder {
-	if existsErr == buntdb.ErrNotFound {
+		// add to new founder's list
-		// this is a new registration, need to update account-to-channels
 		accountChannelsKey := fmt.Sprintf(keyAccountChannels, channelInfo.Founder)
 		alreadyChannels, _ := tx.Get(accountChannelsKey)
 		newChannels := channelKey // this is the casefolded channel name
@@ -272,9 +296,30 @@ func (reg *ChannelRegistry) saveChannel(tx *buntdb.Tx, channelInfo RegisteredCha
 		}
 		tx.Set(accountChannelsKey, newChannels, nil)
 	}
+	if existsErr == nil && founder != channelInfo.Founder {
+		// remove from old founder's list
+		accountChannelsKey := fmt.Sprintf(keyAccountChannels, founder)
+		alreadyChannelsRaw, _ := tx.Get(accountChannelsKey)
+		var newChannels []string
+		if alreadyChannelsRaw != "" {
+			for _, chname := range strings.Split(alreadyChannelsRaw, ",") {
+				if chname != channelInfo.NameCasefolded {
+					newChannels = append(newChannels, chname)
+				}
+			}
+		}
+		tx.Set(accountChannelsKey, strings.Join(newChannels, ","), nil)
+	}
+}
+
+// saveChannel saves a channel to the store.
+func (reg *ChannelRegistry) saveChannel(tx *buntdb.Tx, channelInfo RegisteredChannel, includeFlags uint) {
+	channelKey := channelInfo.NameCasefolded
+	// maintain the mapping of account -> registered channels
+	reg.updateAccountToChannelMapping(tx, channelInfo)
 
 	if includeFlags&IncludeInitial != 0 {
-		tx.Set(chanExistsKey, "1", nil)
+		tx.Set(fmt.Sprintf(keyChannelExists, channelKey), "1", nil)
 		tx.Set(fmt.Sprintf(keyChannelName, channelKey), channelInfo.Name, nil)
 		tx.Set(fmt.Sprintf(keyChannelRegTime, channelKey), strconv.FormatInt(channelInfo.RegisteredAt.Unix(), 10), nil)
 		tx.Set(fmt.Sprintf(keyChannelFounder, channelKey), channelInfo.Founder, nil)
@@ -306,3 +351,48 @@ func (reg *ChannelRegistry) saveChannel(tx *buntdb.Tx, channelInfo RegisteredCha
 		tx.Set(fmt.Sprintf(keyChannelAccountToUMode, channelKey), string(accountToUModeString), nil)
 	}
 }
+
+// PurgeChannel records a channel purge.
+func (reg *ChannelRegistry) PurgeChannel(chname string, record ChannelPurgeRecord) (err error) {
+	serialized, err := json.Marshal(record)
+	if err != nil {
+		return err
+	}
+	serializedStr := string(serialized)
+	key := fmt.Sprintf(keyChannelPurged, chname)
+
+	return reg.server.store.Update(func(tx *buntdb.Tx) error {
+		tx.Set(key, serializedStr, nil)
+		return nil
+	})
+}
+
+// LoadPurgeRecord retrieves information about whether and how a channel was purged.
+func (reg *ChannelRegistry) LoadPurgeRecord(chname string) (record ChannelPurgeRecord, err error) {
+	var rawRecord string
+	key := fmt.Sprintf(keyChannelPurged, chname)
+	reg.server.store.View(func(tx *buntdb.Tx) error {
+		rawRecord, _ = tx.Get(key)
+		return nil
+	})
+	if rawRecord == "" {
+		err = errNoSuchChannel
+		return
+	}
+	err = json.Unmarshal([]byte(rawRecord), &record)
+	if err != nil {
+		reg.server.logger.Error("internal", "corrupt purge record", chname, err.Error())
+		err = errNoSuchChannel
+		return
+	}
+	return
+}
+
+// UnpurgeChannel deletes the record of a channel purge.
+func (reg *ChannelRegistry) UnpurgeChannel(chname string) (err error) {
+	key := fmt.Sprintf(keyChannelPurged, chname)
+	return reg.server.store.Update(func(tx *buntdb.Tx) error {
+		tx.Delete(key)
+		return nil
+	})
+}

irc/chanserv.go

@@ -18,6 +18,7 @@ import (
 )
 
 const chanservHelp = `ChanServ lets you register and manage channels.`
+const chanservMask = "ChanServ!ChanServ@localhost"
 
 func chanregEnabled(config *Config) bool {
 	return config.Channels.Registration.Enabled
@@ -75,12 +76,71 @@ referenced by their registered account names, not their nicknames.`,
 			enabled:   chanregEnabled,
 			minParams: 1,
 		},
+		"clear": {
+			handler: csClearHandler,
+			help: `Syntax: $bCLEAR #channel target$b
+
+CLEAR removes users or settings from a channel. Specifically:
+
+$bCLEAR #channel users$b kicks all users except for you.
+$bCLEAR #channel access$b resets all stored bans, invites, ban exceptions,
+and persistent user-mode grants made with CS AMODE.`,
+			helpShort: `$bCLEAR$b removes users or settings from a channel.`,
+			enabled:   chanregEnabled,
+			minParams: 2,
+		},
+		"transfer": {
+			handler: csTransferHandler,
+			help: `Syntax: $bTRANSFER [accept] #channel user [code]$b
+
+TRANSFER transfers ownership of a channel from one user to another.
+To prevent accidental transfers, a verification code is required. For
+example, $bTRANSFER #channel alice$b displays the required confirmation
+code, then $bTRANSFER #channel alice 2930242125$b initiates the transfer.
+Unless you are an IRC operator with the correct permissions, alice must
+then accept the transfer, which she can do with $bTRANSFER accept #channel$b.`,
+			helpShort: `$bTRANSFER$b transfers ownership of a channel to another user.`,
+			enabled:   chanregEnabled,
+			minParams: 2,
+		},
+		"purge": {
+			handler: csPurgeHandler,
+			help: `Syntax: $bPURGE #channel [reason]$b
+
+PURGE blacklists a channel from the server, making it impossible to join
+or otherwise interact with the channel. If the channel currently has members,
+they will be kicked from it. PURGE may also be applied preemptively to
+channels that do not currently have members.`,
+			helpShort:         `$bPURGE$b blacklists a channel from the server.`,
+			capabs:            []string{"chanreg"},
+			minParams:         1,
+			maxParams:         2,
+			unsplitFinalParam: true,
+		},
+		"unpurge": {
+			handler: csUnpurgeHandler,
+			help: `Syntax: $bUNPURGE #channel$b
+
+UNPURGE removes any blacklisting of a channel that was previously
+set using PURGE.`,
+			helpShort: `$bUNPURGE$b undoes a previous PURGE command.`,
+			capabs:    []string{"chanreg"},
+			minParams: 1,
+		},
+		"info": {
+			handler: csInfoHandler,
+			help: `Syntax: $INFO #channel$b
+
+INFO displays info about a registered channel.`,
+			helpShort: `$bINFO$b displays info about a registered channel.`,
+			minParams: 1,
+		},
 	}
 )
 
 // csNotice sends the client a notice from ChanServ
 func csNotice(rb *ResponseBuffer, text string) {
-	rb.Add(nil, "ChanServ!ChanServ@localhost", "NOTICE", rb.target.Nick(), text)
+	rb.Add(nil, chanservMask, "NOTICE", rb.target.Nick(), text)
 }
 
 func csAmodeHandler(server *Server, client *Client, command string, params []string, rb *ResponseBuffer) {
@@ -219,9 +279,7 @@ func csRegisterHandler(server *Server, client *Client, command string, params []
 	}
 
 	account := client.Account()
-	channelsAlreadyRegistered := server.accounts.ChannelsForAccount(account)
+	if !checkChanLimit(client, rb) {
-	if server.Config().Channels.Registration.MaxChannelsPerAccount <= len(channelsAlreadyRegistered) {
-		csNotice(rb, client.t("You have already registered the maximum number of channels; try dropping some with /CS UNREGISTER"))
 		return
 	}
 
@@ -234,7 +292,7 @@ func csRegisterHandler(server *Server, client *Client, command string, params []
 
 	csNotice(rb, fmt.Sprintf(client.t("Channel %s successfully registered"), channelName))
 
-	server.logger.Info("services", fmt.Sprintf("Client %s registered channel %s", client.nick, channelName))
+	server.logger.Info("services", fmt.Sprintf("Client %s registered channel %s", client.Nick(), channelName))
 	server.snomasks.Send(sno.LocalChannels, fmt.Sprintf(ircfmt.Unescape("Channel registered $c[grey][$r%s$c[grey]] by $c[grey][$r%s$c[grey]]"), channelName, client.nickMaskString))
 
 	// give them founder privs
@@ -249,6 +307,17 @@ func csRegisterHandler(server *Server, client *Client, command string, params []
 	}
 }
 
+// check whether a client has already registered too many channels
+func checkChanLimit(client *Client, rb *ResponseBuffer) (ok bool) {
+	account := client.Account()
+	channelsAlreadyRegistered := client.server.accounts.ChannelsForAccount(account)
+	ok = len(channelsAlreadyRegistered) < client.server.Config().Channels.Registration.MaxChannelsPerAccount || client.HasRoleCapabs("chanreg")
+	if !ok {
+		csNotice(rb, client.t("You have already registered the maximum number of channels; try dropping some with /CS UNREGISTER"))
+	}
+	return
+}
+
 func csUnregisterHandler(server *Server, client *Client, command string, params []string, rb *ResponseBuffer) {
 	channelName := params[0]
 	var verificationCode string
@@ -299,3 +368,204 @@ func unregisterConfirmationCode(name string, registeredAt time.Time) (code strin
 	codeInput.WriteString(strconv.FormatInt(registeredAt.Unix(), 16))
 	return strconv.Itoa(int(crc32.ChecksumIEEE(codeInput.Bytes())))
 }
+
+func csClearHandler(server *Server, client *Client, command string, params []string, rb *ResponseBuffer) {
+	channel := server.channels.Get(params[0])
+	if channel == nil {
+		csNotice(rb, client.t("Channel does not exist"))
+		return
+	}
+	account := client.Account()
+	if !(client.HasRoleCapabs("chanreg") || (account != "" && account == channel.Founder())) {
+		csNotice(rb, client.t("Insufficient privileges"))
+		return
+	}
+
+	switch strings.ToLower(params[1]) {
+	case "access":
+		channel.resetAccess()
+		csNotice(rb, client.t("Successfully reset channel access"))
+	case "users":
+		for _, target := range channel.Members() {
+			if target != client {
+				channel.Kick(client, target, "Cleared by ChanServ", rb, true)
+			}
+		}
+	default:
+		csNotice(rb, client.t("Invalid parameters"))
+	}
+
+}
+
+func csTransferHandler(server *Server, client *Client, command string, params []string, rb *ResponseBuffer) {
+	if strings.ToLower(params[0]) == "accept" {
+		processTransferAccept(client, params[1], rb)
+		return
+	}
+	chname := params[0]
+	channel := server.channels.Get(chname)
+	if channel == nil {
+		csNotice(rb, client.t("Channel does not exist"))
+		return
+	}
+	regInfo := channel.ExportRegistration(0)
+	chname = regInfo.Name
+	account := client.Account()
+	isFounder := account != "" && account == regInfo.Founder
+	hasPrivs := client.HasRoleCapabs("chanreg")
+	if !(isFounder || hasPrivs) {
+		csNotice(rb, client.t("Insufficient privileges"))
+		return
+	}
+	target := params[1]
+	_, err := server.accounts.LoadAccount(params[1])
+	if err != nil {
+		csNotice(rb, client.t("Account does not exist"))
+		return
+	}
+	expectedCode := unregisterConfirmationCode(regInfo.Name, regInfo.RegisteredAt)
+	codeValidated := 2 < len(params) && params[2] == expectedCode
+	if !codeValidated {
+		csNotice(rb, ircfmt.Unescape(client.t("$bWarning: you are about to transfer control of your channel to another user.$b")))
+		csNotice(rb, fmt.Sprintf(client.t("To confirm your channel transfer, type: /CS TRANSFER %[1]s %[2]s %[3]s"), chname, target, expectedCode))
+		return
+	}
+	status, err := channel.Transfer(client, target, hasPrivs)
+	if err == nil {
+		switch status {
+		case channelTransferComplete:
+			csNotice(rb, fmt.Sprintf(client.t("Successfully transferred channel %[1]s to account %[2]s"), chname, target))
+		case channelTransferPending:
+			sendTransferPendingNotice(server, target, chname)
+			csNotice(rb, fmt.Sprintf(client.t("Transfer of channel %[1]s to account %[2]s succeeded, pending acceptance"), chname, target))
+		case channelTransferCancelled:
+			csNotice(rb, fmt.Sprintf(client.t("Cancelled pending transfer of channel %s"), chname))
+		}
+	} else {
+		csNotice(rb, client.t("Could not transfer channel"))
+	}
+}
+
+func sendTransferPendingNotice(server *Server, account, chname string) {
+	clients := server.accounts.AccountToClients(account)
+	if len(clients) == 0 {
+		return
+	}
+	var client *Client
+	for _, candidate := range clients {
+		client = candidate
+		if candidate.NickCasefolded() == candidate.Account() {
+			break // prefer the login where the nick is the account
+		}
+	}
+	client.Send(nil, chanservMask, "NOTICE", client.Nick(), fmt.Sprintf(client.t("You have been offered ownership of channel %s. To accept, /CS TRANSFER ACCEPT %s"), chname, chname))
+}
+
+func processTransferAccept(client *Client, chname string, rb *ResponseBuffer) {
+	channel := client.server.channels.Get(chname)
+	if channel == nil {
+		csNotice(rb, client.t("Channel does not exist"))
+		return
+	}
+	if !checkChanLimit(client, rb) {
+		return
+	}
+	switch channel.AcceptTransfer(client) {
+	case nil:
+		csNotice(rb, fmt.Sprintf(client.t("Successfully accepted ownership of channel %s"), channel.Name()))
+	case errChannelTransferNotOffered:
+		csNotice(rb, fmt.Sprintf(client.t("You weren't offered ownership of channel %s"), channel.Name()))
+	default:
+		csNotice(rb, fmt.Sprintf(client.t("Could not accept ownership of channel %s"), channel.Name()))
+	}
+}
+
+func csPurgeHandler(server *Server, client *Client, command string, params []string, rb *ResponseBuffer) {
+	oper := client.Oper()
+	if oper == nil {
+		return // should be impossible because you need oper capabs for this
+	}
+
+	chname := params[0]
+	var reason string
+	if 1 < len(params) {
+		reason = params[1]
+	}
+	purgeRecord := ChannelPurgeRecord{
+		Oper:     oper.Name,
+		PurgedAt: time.Now().UTC(),
+		Reason:   reason,
+	}
+	switch server.channels.Purge(chname, purgeRecord) {
+	case nil:
+		channel := server.channels.Get(chname)
+		if channel != nil { // channel need not exist to be purged
+			for _, target := range channel.Members() {
+				channel.Kick(client, target, "Cleared by ChanServ", rb, true)
+			}
+		}
+		csNotice(rb, fmt.Sprintf(client.t("Successfully purged channel %s from the server"), chname))
+	case errInvalidChannelName:
+		csNotice(rb, fmt.Sprintf(client.t("Can't purge invalid channel %s"), chname))
+	default:
+		csNotice(rb, client.t("An error occurred"))
+	}
+}
+
+func csUnpurgeHandler(server *Server, client *Client, command string, params []string, rb *ResponseBuffer) {
+	chname := params[0]
+	switch server.channels.Unpurge(chname) {
+	case nil:
+		csNotice(rb, fmt.Sprintf(client.t("Successfully unpurged channel %s from the server"), chname))
+	case errNoSuchChannel:
+		csNotice(rb, fmt.Sprintf(client.t("Channel %s wasn't previously purged from the server"), chname))
+	default:
+		csNotice(rb, client.t("An error occurred"))
+	}
+}
+
+func csInfoHandler(server *Server, client *Client, command string, params []string, rb *ResponseBuffer) {
+	chname, err := CasefoldChannel(params[0])
+	if err != nil {
+		csNotice(rb, client.t("Invalid channel name"))
+		return
+	}
+
+	// purge status
+	if client.HasRoleCapabs("chanreg") {
+		purgeRecord, err := server.channelRegistry.LoadPurgeRecord(chname)
+		if err == nil {
+			csNotice(rb, fmt.Sprintf(client.t("Channel %s was purged by the server operators and cannot be used"), chname))
+			csNotice(rb, fmt.Sprintf(client.t("Purged by operator: %s"), purgeRecord.Oper))
+			csNotice(rb, fmt.Sprintf(client.t("Purged at: %s"), purgeRecord.PurgedAt.Format(time.RFC1123)))
+			if purgeRecord.Reason != "" {
+				csNotice(rb, fmt.Sprintf(client.t("Purge reason: %s"), purgeRecord.Reason))
+			}
+		}
+	} else {
+		if server.channels.IsPurged(chname) {
+			csNotice(rb, fmt.Sprintf(client.t("Channel %s was purged by the server operators and cannot be used"), chname))
+		}
+	}
+
+	var chinfo RegisteredChannel
+	channel := server.channels.Get(params[0])
+	if channel != nil {
+		chinfo = channel.ExportRegistration(0)
+	} else {
+		chinfo, err = server.channelRegistry.LoadChannel(chname)
+		if err != nil && !(err == errNoSuchChannel || err == errFeatureDisabled) {
+			csNotice(rb, client.t("An error occurred"))
+			return
+		}
+	}
+
+	// channel exists but is unregistered, or doesn't exist:
+	if chinfo.Founder == "" {
+		csNotice(rb, fmt.Sprintf(client.t("Channel %s is not registered"), chname))
+		return
+	}
+	csNotice(rb, fmt.Sprintf(client.t("Channel %s is registered"), chinfo.Name))
+	csNotice(rb, fmt.Sprintf(client.t("Founder: %s"), chinfo.Founder))
+	csNotice(rb, fmt.Sprintf(client.t("Registered at: %s"), chinfo.RegisteredAt.Format(time.RFC1123)))
+}

irc/client.go

@@ -637,11 +637,11 @@ func (session *Session) playResume() {
 				}
 			} else {
 				if !session.resumeDetails.HistoryIncomplete {
-					fSession.Send(nil, oldNickmask, "QUIT", fmt.Sprintf(friend.t("Client reconnected")))
+					fSession.Send(nil, oldNickmask, "QUIT", friend.t("Client reconnected"))
 				} else if session.resumeDetails.HistoryIncomplete && !timestamp.IsZero() {
 					fSession.Send(nil, oldNickmask, "QUIT", fmt.Sprintf(friend.t("Client reconnected (up to %d seconds of message history lost)"), gapSeconds))
 				} else {
-					fSession.Send(nil, oldNickmask, "QUIT", fmt.Sprintf(friend.t("Client reconnected (message history may have been lost)")))
+					fSession.Send(nil, oldNickmask, "QUIT", friend.t("Client reconnected (message history may have been lost)"))
 				}
 			}
 		}

irc/errors.go

@@ -30,6 +30,7 @@ var (
 	errCallbackFailed                 = errors.New("Account verification could not be sent")
 	errCertfpAlreadyExists            = errors.New(`An account already exists for your certificate fingerprint`)
 	errChannelNotOwnedByAccount       = errors.New("Channel not owned by the specified account")
+	errChannelTransferNotOffered      = errors.New(`You weren't offered ownership of that channel`)
 	errChannelAlreadyRegistered       = errors.New("Channel is already registered")
 	errChannelNameInUse               = errors.New(`Channel name in use`)
 	errInvalidChannelName             = errors.New(`Invalid channel name`)

irc/handlers.go

@@ -1370,7 +1370,7 @@ func kickHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *Resp
 		if comment == "" {
 			comment = kick.nick
 		}
-		channel.Kick(client, target, comment, rb)
+		channel.Kick(client, target, comment, rb, false)
 	}
 	return false
 }
@@ -1725,15 +1725,14 @@ func cmodeHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *Res
 		prefix := client.NickMaskString()
 		//TODO(dan): we should change the name of String and make it return a slice here
 		args := append([]string{channel.name}, strings.Split(applied.String(), " ")...)
-		for _, member := range channel.Members() {
-			if member == client {
 		rb.Add(nil, prefix, "MODE", args...)
 		for _, session := range client.Sessions() {
 			if session != rb.session {
 				session.Send(nil, prefix, "MODE", args...)
 			}
 		}
-			} else {
+		for _, member := range channel.Members() {
+			if member != client {
 				member.Send(nil, prefix, "MODE", args...)
 			}
 		}
@@ -2359,7 +2358,7 @@ func renameHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *Re
 				if reason != "" {
 					targetRb.Add(nil, targetPrefix, "PART", oldName, fmt.Sprintf(mcl.t("Channel renamed: %s"), reason))
 				} else {
-					targetRb.Add(nil, targetPrefix, "PART", oldName, fmt.Sprintf(mcl.t("Channel renamed")))
+					targetRb.Add(nil, targetPrefix, "PART", oldName, mcl.t("Channel renamed"))
 				}
 				if mSession.capabilities.Has(caps.ExtendedJoin) {
 					targetRb.Add(nil, targetPrefix, "JOIN", newName, mDetails.accountName, mDetails.realname)

irc/hostserv.go

@@ -186,7 +186,7 @@ func hsRequestHandler(server *Server, client *Client, command string, params []s
 	if err != nil {
 		hsNotice(rb, client.t("An error occurred"))
 	} else {
-		hsNotice(rb, fmt.Sprintf(client.t("Your vhost request will be reviewed by an administrator")))
+		hsNotice(rb, client.t("Your vhost request will be reviewed by an administrator"))
 		chanMsg := fmt.Sprintf("Account %s requests vhost %s", accountName, vhost)
 		hsNotifyChannel(server, chanMsg)
 		// TODO send admins a snomask of some kind
@@ -221,7 +221,7 @@ func hsStatusHandler(server *Server, client *Client, command string, params []st
 	if account.VHost.ApprovedVHost != "" {
 		hsNotice(rb, fmt.Sprintf(client.t("Account %[1]s has vhost: %[2]s"), accountName, account.VHost.ApprovedVHost))
 		if !account.VHost.Enabled {
-			hsNotice(rb, fmt.Sprintf(client.t("This vhost is currently disabled, but can be enabled with /HS ON")))
+			hsNotice(rb, client.t("This vhost is currently disabled, but can be enabled with /HS ON"))
 		}
 	} else {
 		hsNotice(rb, fmt.Sprintf(client.t("Account %s has no vhost"), accountName))

irc/modes.go

@@ -119,6 +119,9 @@ func (channel *Channel) ApplyChannelModeChanges(client *Client, isSamode bool, c
 		if isSamode {
 			return true
 		}
+		if details.account != "" && details.account == channel.Founder() {
+			return true
+		}
 		switch change.Mode {
 		case modes.ChannelFounder, modes.ChannelAdmin, modes.ChannelOperator, modes.Halfop, modes.Voice:
 			// List on these modes is a no-op anyway
@@ -289,15 +292,16 @@ func (channel *Channel) ProcessAccountToUmodeChange(client *Client, change modes
 		targetModeAfter = change.Mode
 	}
 
-	// operators and founders can do anything
+	// server operators and founders can do anything:
 	hasPrivs := isOperChange || (account != "" && account == channel.registeredFounder)
-	// halfop and up can list, and do add/removes at levels <= their own
+	// halfop and up can list:
 	if change.Op == modes.List && (clientMode == modes.Halfop || umodeGreaterThan(clientMode, modes.Halfop)) {
 		hasPrivs = true
+		// you can do adds or removes at levels you have "privileges over":
 	} else if channelUserModeHasPrivsOver(clientMode, targetModeNow) && channelUserModeHasPrivsOver(clientMode, targetModeAfter) {
 		hasPrivs = true
+		// and you can always de-op yourself:
 	} else if change.Op == modes.Remove && account == change.Arg {
-		// you can always de-op yourself
 		hasPrivs = true
 	}
 	if !hasPrivs {

irc/nickserv.go

@@ -310,19 +310,19 @@ func displaySetting(settingName string, settings AccountSettings, client *Client
 		}
 	case "bouncer":
 		if !config.Accounts.Bouncer.Enabled {
-			nsNotice(rb, fmt.Sprintf(client.t("This feature has been disabled by the server administrators")))
+			nsNotice(rb, client.t("This feature has been disabled by the server administrators"))
 		} else {
 			switch settings.AllowBouncer {
 			case BouncerAllowedServerDefault:
 				if config.Accounts.Bouncer.AllowedByDefault {
-					nsNotice(rb, fmt.Sprintf(client.t("Bouncer functionality is currently enabled for your account, but you can opt out")))
+					nsNotice(rb, client.t("Bouncer functionality is currently enabled for your account, but you can opt out"))
 				} else {
-					nsNotice(rb, fmt.Sprintf(client.t("Bouncer functionality is currently disabled for your account, but you can opt in")))
+					nsNotice(rb, client.t("Bouncer functionality is currently disabled for your account, but you can opt in"))
 				}
 			case BouncerDisallowedByUser:
-				nsNotice(rb, fmt.Sprintf(client.t("Bouncer functionality is currently disabled for your account")))
+				nsNotice(rb, client.t("Bouncer functionality is currently disabled for your account"))
 			case BouncerAllowedByUser:
-				nsNotice(rb, fmt.Sprintf(client.t("Bouncer functionality is currently enabled for your account")))
+				nsNotice(rb, client.t("Bouncer functionality is currently enabled for your account"))
 			}
 		}
 	default:
@@ -569,7 +569,7 @@ func nsInfoHandler(server *Server, client *Client, command string, params []stri
 	}
 
 	nsNotice(rb, fmt.Sprintf(client.t("Account: %s"), account.Name))
-	registeredAt := account.RegisteredAt.Format("Jan 02, 2006 15:04:05Z")
+	registeredAt := account.RegisteredAt.Format(time.RFC1123)
 	nsNotice(rb, fmt.Sprintf(client.t("Registered at: %s"), registeredAt))
 	// TODO nicer formatting for this
 	for _, nick := range account.AdditionalNicks {