// Copyright (c) Liam Stanley <me@liamstanley.io>. All rights reserved. Use // of this source code is governed by the MIT license that can be found in // the LICENSE file. package girc import ( "context" "crypto/tls" "errors" "fmt" "io" "io/ioutil" "log" "net" "os" "runtime" "sort" "strconv" "strings" "sync" "time" ) // Client contains all of the information necessary to run a single IRC // client. type Client struct { // Config represents the configuration. Please take extra caution in that // entries in this are not edited while the client is connected, to prevent // data races. This is NOT concurrent safe to update. Config Config // rx is a buffer of events waiting to be processed. rx chan *Event // tx is a buffer of events waiting to be sent. tx chan *Event // state represents the throw-away state for the irc session. state *state // initTime represents the creation time of the client. initTime time.Time // Handlers is a handler which manages internal and external handlers. Handlers *Caller // CTCP is a handler which manages internal and external CTCP handlers. CTCP *CTCP // Cmd contains various helper methods to interact with the server. Cmd *Commands // mu is the mux used for connections/disconnections from the server, // so multiple threads aren't trying to connect at the same time, and // vice versa. mu sync.RWMutex // stop is used to communicate with Connect(), letting it know that the // client wishes to cancel/close. stop context.CancelFunc // conn is a net.Conn reference to the IRC server. If this is nil, it is // safe to assume that we're not connected. If this is not nil, this // means we're either connected, connecting, or cleaning up. This should // be guarded with Client.mu. conn *ircConn // debug is used if a writer is supplied for Client.Config.Debugger. debug *log.Logger } // Config contains configuration options for an IRC client type Config struct { // Server is a host/ip of the server you want to connect to. This only // has an affect during the dial process Server string // ServerPass is the server password used to authenticate. This only has // an affect during the dial process. ServerPass string // Port is the port that will be used during server connection. This only // has an affect during the dial process. Port int // Nick is an rfc-valid nickname used during connection. This only has an // affect during the dial process. Nick string // User is the username/ident to use on connect. Ignored if an identd // server is used. This only has an affect during the dial process. User string // Name is the "realname" that's used during connection. This only has an // affect during the dial process. Name string // SASL contains the necessary authentication data to authenticate // with SASL. See the documentation for SASLMech for what is currently // supported. Capability tracking must be enabled for this to work, as // this requires IRCv3 CAP handling. SASL SASLMech // WebIRC allows forwarding source user hostname/ip information to the server // (if supported by the server) to ensure the source machine doesn't show as // the source. See the WebIRC type for more information. WebIRC WebIRC // Bind is used to bind to a specific host or ip during the dial process // when connecting to the server. This can be a hostname, however it must // resolve to an IPv4/IPv6 address bindable on your system. Otherwise, // you can simply use a IPv4/IPv6 address directly. This only has an // affect during the dial process and will not work with DialerConnect(). Bind string // SSL allows dialing via TLS. See TLSConfig to set your own TLS // configuration (e.g. to not force hostname checking). This only has an // affect during the dial process. SSL bool // DisableSTS disables the use of automatic STS connection upgrades // when the server supports STS. STS can also be disabled using the environment // variable "GIRC_DISABLE_STS=true". As many clients may not propagate options // like this back to the user, this allows to directly disable such automatic // functionality. DisableSTS bool // DisableSTSFallback disables the "fallback" to a non-tls connection if the // strict transport policy expires and the first attempt to reconnect back to // the tls version fails. DisableSTSFallback bool // TLSConfig is an optional user-supplied tls configuration, used during // socket creation to the server. SSL must be enabled for this to be used. // This only has an affect during the dial process. TLSConfig *tls.Config // AllowFlood allows the client to bypass the rate limit of outbound // messages. AllowFlood bool // GlobalFormat enables passing through all events which have trailing // text through the color Fmt() function, so you don't have to wrap // every response in the Fmt() method. // // Note that this only actually applies to PRIVMSG, NOTICE and TOPIC // events, to ensure it doesn't clobber unwanted events. GlobalFormat bool // Debug is an optional, user supplied location to log the raw lines // sent from the server, or other useful debug logs. Defaults to // ioutil.Discard. For quick debugging, this could be set to os.Stdout. Debug io.Writer // Out is used to write out a prettified version of incoming events. For // example, channel JOIN/PART, PRIVMSG/NOTICE, KICk, etc. Useful to get // a brief output of the activity of the client. If you are looking to // log raw messages, look at a handler and girc.ALLEVENTS and the relevant // Event.Bytes() or Event.String() methods. Out io.Writer // RecoverFunc is called when a handler throws a panic. If RecoverFunc is // set, the panic will be considered recovered, otherwise the client will // panic. Set this to DefaultRecoverHandler if you don't want the client // to panic, however you don't want to handle the panic yourself. // DefaultRecoverHandler will log the panic to Debug or os.Stdout if // Debug is unset. RecoverFunc func(c *Client, e *HandlerError) // SupportedCaps are the IRCv3 capabilities you would like the client to // support on top of the ones which the client already supports (see // cap.go for which ones the client enables by default). Only use this // if you have not called DisableTracking(). The keys value gets passed // to the server if supported. SupportedCaps map[string][]string // Version is the application version information that will be used in // response to a CTCP VERSION, if default CTCP replies have not been // overwritten or a VERSION handler was already supplied. Version string // PingDelay is the frequency between when the client sends a keep-alive // PING to the server, and awaits a response (and times out if the server // doesn't respond in time). This should be between 20-600 seconds. See // Client.Latency() if you want to determine the delay between the server // and the client. If this is set to -1, the client will not attempt to // send client -> server PING requests. PingDelay time.Duration // disableTracking disables all channel and user-level tracking. Useful // for highly embedded scripts with single purposes. This has an exported // method which enables this and ensures proper cleanup, see // Client.DisableTracking(). disableTracking bool // HandleNickCollide when set, allows the client to handle nick collisions // in a custom way. If unset, the client will attempt to append a // underscore to the end of the nickname, in order to bypass using // an invalid nickname. For example, if "test" is already in use, or is // blocked by the network/a service, the client will try and use "test_", // then it will attempt "test__", "test___", and so on. HandleNickCollide func(oldNick string) (newNick string) } // WebIRC is useful when a user connects through an indirect method, such web // clients, the indirect client sends its own IP address instead of sending the // user's IP address unless WebIRC is implemented by both the client and the // server. // // Client expectations: // - Perform any proxy resolution. // - Check the reverse DNS and forward DNS match. // - Check the IP against suitable access controls (ipaccess, dnsbl, etc). // // More information: // - https://ircv3.net/specs/extensions/webirc.html // - https://kiwiirc.com/docs/webirc type WebIRC struct { // Password that authenticates the WEBIRC command from this client. Password string // Gateway or client type requesting spoof (cgiirc defaults to cgiirc, as an // example). Gateway string // Hostname of user. Hostname string // Address either in IPv4 dotted quad notation (e.g. 192.0.0.2) or IPv6 // notation (e.g. 1234:5678:9abc::def). IPv4-in-IPv6 addresses // (e.g. ::ffff:192.0.0.2) should not be sent. Address string } // Params returns the arguments for the WEBIRC command that can be passed to the // server. func (w WebIRC) Params() []string { return []string{w.Password, w.Gateway, w.Hostname, w.Address} } // ErrInvalidConfig is returned when the configuration passed to the client // is invalid. type ErrInvalidConfig struct { Conf Config // Conf is the configuration that was not valid. err error } func (e ErrInvalidConfig) Error() string { return "invalid configuration: " + e.err.Error() } // isValid checks some basic settings to ensure the config is valid. func (conf *Config) isValid() error { if conf.Server == "" { return &ErrInvalidConfig{Conf: *conf, err: errors.New("empty server")} } // Default port to 6667 (the standard IRC port). if conf.Port == 0 { conf.Port = 6667 } if conf.Port < 1 || conf.Port > 65535 { return &ErrInvalidConfig{Conf: *conf, err: errors.New("port outside valid range (1-65535)")} } if !IsValidNick(conf.Nick) { return &ErrInvalidConfig{Conf: *conf, err: errors.New("bad nickname specified")} } if !IsValidUser(conf.User) { return &ErrInvalidConfig{Conf: *conf, err: errors.New("bad user/ident specified")} } return nil } // ErrNotConnected is returned if a method is used when the client isn't // connected. var ErrNotConnected = errors.New("client is not connected to server") // New creates a new IRC client with the specified server, name and config. func New(config Config) *Client { c := &Client{ Config: config, rx: make(chan *Event, 25), tx: make(chan *Event, 25), CTCP: newCTCP(), initTime: time.Now(), } c.Cmd = &Commands{c: c} if c.Config.PingDelay >= 0 && c.Config.PingDelay < (20*time.Second) { c.Config.PingDelay = 20 * time.Second } else if c.Config.PingDelay > (600 * time.Second) { c.Config.PingDelay = 600 * time.Second } envDebug, _ := strconv.ParseBool(os.Getenv("GIRC_DEBUG")) if c.Config.Debug == nil { if envDebug { c.debug = log.New(os.Stderr, "debug:", log.Ltime|log.Lshortfile) } else { c.debug = log.New(ioutil.Discard, "", 0) } } else { if envDebug { if c.Config.Debug != os.Stdout && c.Config.Debug != os.Stderr { c.Config.Debug = io.MultiWriter(os.Stderr, c.Config.Debug) } } c.debug = log.New(c.Config.Debug, "debug:", log.Ltime|log.Lshortfile) c.debug.Print("initializing debugging") } envDisableSTS, _ := strconv.ParseBool((os.Getenv("GIRC_DISABLE_STS"))) if envDisableSTS { c.Config.DisableSTS = envDisableSTS } // Setup the caller. c.Handlers = newCaller(c.debug) // Give ourselves a new state. c.state = &state{} c.state.reset(true) // Register builtin handlers. c.registerBuiltins() // Register default CTCP responses. c.CTCP.addDefaultHandlers() return c } // String returns a brief description of the current client state. func (c *Client) String() string { connected := c.IsConnected() return fmt.Sprintf( "<Client init:%q handlers:%d connected:%t>", c.initTime.String(), c.Handlers.Len(), connected, ) } // TLSConnectionState returns the TLS connection state from tls.Conn{}, which // is useful to return needed TLS fingerprint info, certificates, verify cert // expiration dates, etc. Will only return an error if the underlying // connection wasn't established using TLS (see ErrConnNotTLS), or if the // client isn't connected. func (c *Client) TLSConnectionState() (*tls.ConnectionState, error) { c.mu.RLock() defer c.mu.RUnlock() if c.conn == nil { return nil, ErrNotConnected } c.conn.mu.RLock() defer c.conn.mu.RUnlock() if !c.conn.connected { return nil, ErrNotConnected } if tlsConn, ok := c.conn.sock.(*tls.Conn); ok { cs := tlsConn.ConnectionState() return &cs, nil } return nil, ErrConnNotTLS } // ErrConnNotTLS is returned when Client.TLSConnectionState() is called, and // the connection to the server wasn't made with TLS. var ErrConnNotTLS = errors.New("underlying connection is not tls") // Close closes the network connection to the server, and sends a CLOSED // event. This should cause Connect() to return with nil. This should be // safe to call multiple times. See Connect()'s documentation on how // handlers and goroutines are handled when disconnected from the server. func (c *Client) Close() { c.mu.RLock() if c.stop != nil { c.debug.Print("requesting client to stop") c.stop() } c.mu.RUnlock() } // Quit sends a QUIT message to the server with a given reason to close the // connection. Underlying this event being sent, Client.Close() is called as well. // This is different than just calling Client.Close() in that it provides a reason // as to why the connection was closed (for bots to tell users the bot is restarting, // or shutting down, etc). // // NOTE: servers may delay showing of QUIT reasons, until you've been connected to // the server for a certain period of time (e.g. 5 minutes). Keep this in mind. func (c *Client) Quit(reason string) { c.Send(&Event{Command: QUIT, Params: []string{reason}}) } // ErrEvent is an error returned when the server (or library) sends an ERROR // message response. The string returned contains the trailing text from the // message. type ErrEvent struct { Event *Event } func (e *ErrEvent) Error() string { if e.Event == nil { return "unknown error occurred" } return e.Event.Last() } func (c *Client) execLoop(ctx context.Context, errs chan error, wg *sync.WaitGroup) { c.debug.Print("starting execLoop") defer c.debug.Print("closing execLoop") var event *Event for { select { case <-ctx.Done(): // We've been told to exit, however we shouldn't bail on the // current events in the queue that should be processed, as one // may want to handle an ERROR, QUIT, etc. c.debug.Printf("received signal to close, flushing %d events and executing", len(c.rx)) for { select { case event = <-c.rx: c.RunHandlers(event) default: goto done } } done: wg.Done() return case event = <-c.rx: if event != nil && event.Command == ERROR { // Handles incoming ERROR responses. These are only ever sent // by the server (with the exception that this library may use // them as a lower level way of signalling to disconnect due // to some other client-choosen error), and should always be // followed up by the server disconnecting the client. If for // some reason the server doesn't disconnect the client, or // if this library is the source of the error, this should // signal back up to the main connect loop, to disconnect. errs <- &ErrEvent{Event: event} // Make sure to not actually exit, so we can let any handlers // actually handle the ERROR event. } c.RunHandlers(event) } } } // DisableTracking disables all channel/user-level/CAP tracking, and clears // all internal handlers. Useful for highly embedded scripts with single // purposes. This cannot be un-done on a client. func (c *Client) DisableTracking() { c.debug.Print("disabling tracking") c.Config.disableTracking = true c.Handlers.clearInternal() c.state.Lock() c.state.channels = nil c.state.Unlock() c.state.notify(c, UPDATE_STATE) c.registerBuiltins() } // Server returns the string representation of host+port pair for the connection. func (c *Client) Server() string { c.state.Lock() defer c.state.Lock() return c.server() } // server returns the string representation of host+port pair for net.Conn, and // takes into consideration STS. Must lock state mu first! func (c *Client) server() string { if c.state.sts.enabled() { return net.JoinHostPort(c.Config.Server, strconv.Itoa(c.state.sts.upgradePort)) } return net.JoinHostPort(c.Config.Server, strconv.Itoa(c.Config.Port)) } // Lifetime returns the amount of time that has passed since the client was // created. func (c *Client) Lifetime() time.Duration { return time.Since(c.initTime) } // Uptime is the time at which the client successfully connected to the // server. func (c *Client) Uptime() (up *time.Time, err error) { if !c.IsConnected() { return nil, ErrNotConnected } c.mu.RLock() c.conn.mu.RLock() up = c.conn.connTime c.conn.mu.RUnlock() c.mu.RUnlock() return up, nil } // ConnSince is the duration that has past since the client successfully // connected to the server. func (c *Client) ConnSince() (since *time.Duration, err error) { if !c.IsConnected() { return nil, ErrNotConnected } c.mu.RLock() c.conn.mu.RLock() timeSince := time.Since(*c.conn.connTime) c.conn.mu.RUnlock() c.mu.RUnlock() return &timeSince, nil } // IsConnected returns true if the client is connected to the server. func (c *Client) IsConnected() bool { c.mu.RLock() if c.conn == nil { c.mu.RUnlock() return false } c.conn.mu.RLock() connected := c.conn.connected c.conn.mu.RUnlock() c.mu.RUnlock() return connected } // GetNick returns the current nickname of the active connection. Panics if // tracking is disabled. func (c *Client) GetNick() string { c.panicIfNotTracking() c.state.RLock() defer c.state.RUnlock() if c.state.nick == "" { return c.Config.Nick } return c.state.nick } // GetID returns an RFC1459 compliant version of the current nickname. Panics // if tracking is disabled. func (c *Client) GetID() string { return ToRFC1459(c.GetNick()) } // GetIdent returns the current ident of the active connection. Panics if // tracking is disabled. May be empty, as this is obtained from when we join // a channel, as there is no other more efficient method to return this info. func (c *Client) GetIdent() string { c.panicIfNotTracking() c.state.RLock() defer c.state.RUnlock() if c.state.ident == "" { return c.Config.User } return c.state.ident } // GetHost returns the current host of the active connection. Panics if // tracking is disabled. May be empty, as this is obtained from when we join // a channel, as there is no other more efficient method to return this info. func (c *Client) GetHost() (host string) { c.panicIfNotTracking() c.state.RLock() host = c.state.host c.state.RUnlock() return host } // ChannelList returns the (sorted) active list of channel names that the client // is in. Panics if tracking is disabled. func (c *Client) ChannelList() []string { c.panicIfNotTracking() c.state.RLock() channels := make([]string, 0, len(c.state.channels)) for channel := range c.state.channels { channels = append(channels, c.state.channels[channel].Name) } c.state.RUnlock() sort.Strings(channels) return channels } // Channels returns the (sorted) active channels that the client is in. Panics // if tracking is disabled. func (c *Client) Channels() []*Channel { c.panicIfNotTracking() c.state.RLock() channels := make([]*Channel, 0, len(c.state.channels)) for channel := range c.state.channels { channels = append(channels, c.state.channels[channel].Copy()) } c.state.RUnlock() sort.Slice(channels, func(i, j int) bool { return channels[i].Name < channels[j].Name }) return channels } // UserList returns the (sorted) active list of nicknames that the client is // tracking across all channels. Panics if tracking is disabled. func (c *Client) UserList() []string { c.panicIfNotTracking() c.state.RLock() users := make([]string, 0, len(c.state.users)) for user := range c.state.users { users = append(users, c.state.users[user].Nick) } c.state.RUnlock() sort.Strings(users) return users } // Users returns the (sorted) active users that the client is tracking across // all channels. Panics if tracking is disabled. func (c *Client) Users() []*User { c.panicIfNotTracking() c.state.RLock() users := make([]*User, 0, len(c.state.users)) for user := range c.state.users { users = append(users, c.state.users[user].Copy()) } c.state.RUnlock() sort.Slice(users, func(i, j int) bool { return users[i].Nick < users[j].Nick }) return users } // LookupChannel looks up a given channel in state. If the channel doesn't // exist, nil is returned. Panics if tracking is disabled. func (c *Client) LookupChannel(name string) (channel *Channel) { c.panicIfNotTracking() if name == "" { return nil } c.state.RLock() channel = c.state.lookupChannel(name).Copy() c.state.RUnlock() return channel } // LookupUser looks up a given user in state. If the user doesn't exist, nil // is returned. Panics if tracking is disabled. func (c *Client) LookupUser(nick string) (user *User) { c.panicIfNotTracking() if nick == "" { return nil } c.state.RLock() user = c.state.lookupUser(nick).Copy() c.state.RUnlock() return user } // IsInChannel returns true if the client is in channel. Panics if tracking // is disabled. func (c *Client) IsInChannel(channel string) (in bool) { c.panicIfNotTracking() c.state.RLock() _, in = c.state.channels[ToRFC1459(channel)] c.state.RUnlock() return in } // GetServerOption retrieves a server capability setting that was retrieved // during client connection. This is also known as ISUPPORT (or RPL_PROTOCTL). // Will panic if used when tracking has been disabled. Examples of usage: // // nickLen, success := GetServerOption("MAXNICKLEN") // func (c *Client) GetServerOption(key string) (result string, ok bool) { c.panicIfNotTracking() c.state.RLock() result, ok = c.state.serverOptions[key] c.state.RUnlock() return result, ok } // NetworkName returns the network identifier. E.g. "EsperNet", "ByteIRC". // May be empty if the server does not support RPL_ISUPPORT (or RPL_PROTOCTL). // Will panic if used when tracking has been disabled. func (c *Client) NetworkName() (name string) { c.panicIfNotTracking() name, _ = c.GetServerOption("NETWORK") return name } // ServerVersion returns the server software version, if the server has // supplied this information during connection. May be empty if the server // does not support RPL_MYINFO. Will panic if used when tracking has been // disabled. func (c *Client) ServerVersion() (version string) { c.panicIfNotTracking() version, _ = c.GetServerOption("VERSION") return version } // ServerMOTD returns the servers message of the day, if the server has sent // it upon connect. Will panic if used when tracking has been disabled. func (c *Client) ServerMOTD() (motd string) { c.panicIfNotTracking() c.state.RLock() motd = c.state.motd c.state.RUnlock() return motd } // Latency is the latency between the server and the client. This is measured // by determining the difference in time between when we ping the server, and // when we receive a pong. func (c *Client) Latency() (delta time.Duration) { c.mu.RLock() c.conn.mu.RLock() delta = c.conn.lastPong.Sub(c.conn.lastPing) c.conn.mu.RUnlock() c.mu.RUnlock() if delta < 0 { return 0 } return delta } // HasCapability checks if the client connection has the given capability. If // you want the full list of capabilities, listen for the girc.CAP_ACK event. // Will panic if used when tracking has been disabled. func (c *Client) HasCapability(name string) (has bool) { c.panicIfNotTracking() if !c.IsConnected() { return false } name = strings.ToLower(name) c.state.RLock() for key := range c.state.enabledCap { key = strings.ToLower(key) if key == name { has = true break } } c.state.RUnlock() return has } // panicIfNotTracking will throw a panic when it's called, and tracking is // disabled. Adds useful info like what function specifically, and where it // was called from. func (c *Client) panicIfNotTracking() { if !c.Config.disableTracking { return } pc, _, _, _ := runtime.Caller(1) fn := runtime.FuncForPC(pc) _, file, line, _ := runtime.Caller(2) panic(fmt.Sprintf("%s used when tracking is disabled (caller %s:%d)", fn.Name(), file, line)) } func (c *Client) debugLogEvent(e *Event, dropped bool) { var prefix string if dropped { prefix = "dropping event (disconnected):" } else { prefix = ">" } if e.Sensitive { c.debug.Printf(prefix, " %s ***redacted***", e.Command) } else { c.debug.Print(prefix, " ", StripRaw(e.String())) } if c.Config.Out != nil { if pretty, ok := e.Pretty(); ok { fmt.Fprintln(c.Config.Out, StripRaw(pretty)) } } }