make default channel modes configurable

irc/channel.go

@@ -57,7 +57,7 @@ func NewChannel(s *Server, name string, addDefaultModes bool) *Channel {
 	}
 
 	if addDefaultModes {
-		for _, mode := range DefaultChannelModes {
+		for _, mode := range s.defaultChannelModes {
 			channel.flags[mode] = true
 		}
 	}

irc/config.go

@@ -217,6 +217,7 @@ type Config struct {
 	}
 
 	Channels struct {
+		DefaultModes *string `yaml:"default-modes"`
 		Registration ChannelRegistrationConfig
 	}
 

irc/modes.go

@@ -149,6 +149,7 @@ var (
 	supportedChannelModesString = SupportedChannelModes.String()
 
 	// DefaultChannelModes are enabled on brand new channels when they're created.
+	// this can be overridden in the `channels` config, with the `default-modes` key
 	DefaultChannelModes = Modes{
 		NoOutside, OpOnlyTopic,
 	}
@@ -385,6 +386,23 @@ func umodeHandler(server *Server, client *Client, msg ircmsg.IrcMessage) bool {
 	return false
 }
 
+// ParseDefaultChannelModes parses the `default-modes` line of the config
+func ParseDefaultChannelModes(config *Config) Modes {
+	if config.Channels.DefaultModes == nil {
+		// not present in config, fall back to compile-time default
+		return DefaultChannelModes
+	}
+	modeChangeStrings := strings.Split(strings.TrimSpace(*config.Channels.DefaultModes), " ")
+	modeChanges, _ := ParseChannelModeChanges(modeChangeStrings...)
+	defaultChannelModes := make(Modes, 0)
+	for _, modeChange := range modeChanges {
+		if modeChange.op == Add {
+			defaultChannelModes = append(defaultChannelModes, modeChange.mode)
+		}
+	}
+	return defaultChannelModes
+}
+
 // ParseChannelModeChanges returns the valid changes, and the list of unknown chars.
 func ParseChannelModeChanges(params ...string) (ModeChanges, map[rune]bool) {
 	changes := make(ModeChanges, 0)
@@ -392,6 +410,9 @@ func ParseChannelModeChanges(params ...string) (ModeChanges, map[rune]bool) {
 
 	if 0 < len(params) {
 		modeArg := params[0]
+		if len(modeArg) == 0 {
+			return changes, unknown
+		}
 		op := ModeOp(modeArg[0])
 		if (op == Add) || (op == Remove) {
 			modeArg = modeArg[1:]

irc/server.go

@@ -97,6 +97,7 @@ type Server struct {
 	connectionThrottleMutex      sync.Mutex // used when affecting the connection limiter, to make sure rehashing doesn't make things go out-of-whack
 	ctime                        time.Time
 	currentOpers                 map[*Client]bool
+	defaultChannelModes          Modes
 	dlines                       *DLineManager
 	isupport                     *ISupportList
 	klines                       *KLineManager
@@ -205,6 +206,7 @@ func NewServer(configFilename string, config *Config, logger *logger.Manager) (*
 		connectionThrottle:           connectionThrottle,
 		ctime:                        time.Now(),
 		currentOpers:                 make(map[*Client]bool),
+		defaultChannelModes:          ParseDefaultChannelModes(config),
 		limits: Limits{
 			AwayLen:        int(config.Limits.AwayLen),
 			ChannelLen:     int(config.Limits.ChannelLen),
@@ -1620,6 +1622,8 @@ func (server *Server) rehash() error {
 	server.accountRegistration = &accountReg
 	server.channelRegistrationEnabled = config.Channels.Registration.Enabled
 
+	server.defaultChannelModes = ParseDefaultChannelModes(config)
+
 	// set new sendqueue size
 	if config.Server.MaxSendQBytes != server.MaxSendQBytes {
 		server.MaxSendQBytes = config.Server.MaxSendQBytes

oragono.yaml

@@ -137,6 +137,11 @@ accounts:
 
 # channel options
 channels:
+    # modes that are set when new channels are created
+    # +n is no-external-messages and +t is op-only-topic
+    # see  /QUOTE HELP cmodes  for more channel modes
+    default-modes: +nt
+
     # channel registration - requires an account
     registration:
         # can users register new channels?