Very initial maxline work

CHANGELOG.md

@@ -37,6 +37,7 @@ This release also updates the database, so be sure to run the `oragono upgradedb
 ### Added
 * Added ability to ban IP addresses and networks from the server with the `DLINE` and `UNDLINE` commands.
 * Added alpha REST API (intended primarily for use with a future web interface to manage accounts, DLINEs, etc).
+* Added proposed IRCv3 capability [`maxline`](https://github.com/ircv3/ircv3-specifications/pull/281).
 
 ### Changed
 * Database upgraded to make handling accounts simpler.

irc/capability.go

@@ -22,6 +22,7 @@ const (
 	EchoMessage     Capability = "echo-message"
 	ExtendedJoin    Capability = "extended-join"
 	InviteNotify    Capability = "invite-notify"
+	MaxLine         Capability = "draft/maxline"
 	MessageTags     Capability = "draft/message-tags"
 	MultiPrefix     Capability = "multi-prefix"
 	SASL            Capability = "sasl"
@@ -39,6 +40,7 @@ var (
 		EchoMessage:   true,
 		ExtendedJoin:  true,
 		InviteNotify:  true,
+		// MaxLine is set during server startup
 		MessageTags: true,
 		MultiPrefix: true,
 		// SASL is set during server startup

irc/client.go

@@ -152,7 +152,14 @@ func (client *Client) run() {
 			break
 		}
 
-		msg, err = ircmsg.ParseLine(line)
+		var maxLen int
+		if client.capabilities[MaxLine] {
+			maxLen = maxLineLength
+		} else {
+			maxLen = 512
+		}
+
+		msg, err = ircmsg.ParseLineMaxLen(line, maxLen)
 		if err != nil {
 			client.Quit("received malformed line")
 			break
@@ -505,9 +512,16 @@ func (client *Client) Send(tags *map[string]ircmsg.TagValue, prefix string, comm
 		}
 	}
 
+	var maxLen int
+	if client.capabilities[MaxLine] {
+		maxLen = maxLineLength
+	} else {
+		maxLen = 512
+	}
+
 	// send out the message
 	message := ircmsg.MakeMessage(tags, prefix, command, params...)
-	line, err := message.Line()
+	line, err := message.LineMaxLen(maxLen)
 	if err != nil {
 		// try not to fail quietly - especially useful when running tests, as a note to dig deeper
 		// log.Println("Error assembling message:")

irc/config.go

@@ -151,14 +151,15 @@ type Config struct {
 	Opers map[string]*OperConfig
 
 	Limits struct {
-		NickLen        uint `yaml:"nicklen"`
-		ChannelLen     uint `yaml:"channellen"`
 		AwayLen        uint `yaml:"awaylen"`
+		ChanListModes  uint `yaml:"chan-list-modes"`
+		ChannelLen     uint `yaml:"channellen"`
 		KickLen        uint `yaml:"kicklen"`
+		LineLen        uint `yaml:"linelen"`
+		MonitorEntries uint `yaml:"monitor-entries"`
+		NickLen        uint `yaml:"nicklen"`
 		TopicLen       uint `yaml:"topiclen"`
 		WhowasEntries  uint `yaml:"whowas-entries"`
-		MonitorEntries uint `yaml:"monitor-entries"`
-		ChanListModes  uint `yaml:"chan-list-modes"`
 	}
 }
 
@@ -335,6 +336,9 @@ func LoadConfig(filename string) (config *Config, err error) {
 			return nil, fmt.Errorf("Could not parse connection-throttle ban-duration: %s", err.Error())
 		}
 	}
+	if config.Limits.LineLen < 512 {
+		return nil, errors.New("Line length must be 512 or greater")
+	}
 
 	return config, nil
 }

irc/constants.go

@@ -16,6 +16,8 @@ var (
 	// Ver is the full version of Oragono, used in responses to clients.
 	Ver = fmt.Sprintf("oragono-%s", SemVer)
 
+	// Used as the standard maximum line length unless overridden at runtime.
+	maxLineLength = 512
 	// maxLastArgLength is used to simply cap off the final argument when creating general messages where we need to select a limit.
 	// for instance, in MONITOR lists, RPL_ISUPPORT lists, etc.
 	maxLastArgLength = 400

irc/server.go

@@ -46,6 +46,7 @@ type Limits struct {
 	NickLen        int
 	TopicLen       int
 	ChanListModes  int
+	LineLen        int
 }
 
 // ListenerInterface represents an interface for a listener.
@@ -146,6 +147,12 @@ func NewServer(configFilename string, config *Config) *Server {
 		SupportedCapabilities[SASL] = true
 	}
 
+	if config.Limits.LineLen > 512 {
+		maxLineLength = int(config.Limits.LineLen)
+		SupportedCapabilities[MaxLine] = true
+		CapValues[MaxLine] = strconv.Itoa(int(config.Limits.LineLen))
+	}
+
 	operClasses, err := config.OperatorClasses()
 	if err != nil {
 		log.Fatal("Error loading oper classes:", err.Error())
@@ -184,6 +191,7 @@ func NewServer(configFilename string, config *Config) *Server {
 			NickLen:        int(config.Limits.NickLen),
 			TopicLen:       int(config.Limits.TopicLen),
 			ChanListModes:  int(config.Limits.ChanListModes),
+			LineLen:        int(config.Limits.LineLen),
 		},
 		listeners:      make(map[string]ListenerInterface),
 		monitoring:     make(map[string][]Client),
@@ -1099,6 +1107,11 @@ func (server *Server) rehash() error {
 		return fmt.Errorf("Error rehashing config file config: %s", err.Error())
 	}
 
+	// line lengths cannot be changed after launching the server
+	if maxLineLength != int(config.Limits.LineLen) {
+		return fmt.Errorf("Maximum line length (linelen) cannot be changed after launching the server, rehash aborted")
+	}
+
 	// confirm connectionLimits are fine
 	connectionLimits, err := NewConnectionLimits(config.Server.ConnectionLimits)
 	if err != nil {

oragono.yaml

@@ -186,13 +186,13 @@ limits:
     channellen: 64
 
     # awaylen is the maximum length of an away message
-    awaylen: 200
+    awaylen: 500
 
     # kicklen is the maximum length of a kick message
-    kicklen: 390
+    kicklen: 1000
 
     # topiclen is the maximum length of a channel topic
-    topiclen: 390
+    topiclen: 1000
 
     # maximum number of monitor entries a client can have
     monitor-entries: 100
@@ -202,3 +202,6 @@ limits:
 
     # maximum length of channel lists (beI modes)
     chan-list-modes: 60
+
+    # maximum length of IRC lines
+    linelen: 2048