package soju import ( "crypto" "crypto/sha256" "crypto/tls" "crypto/x509" "encoding/base64" "errors" "fmt" "io" "net" "strconv" "strings" "time" "unicode" "unicode/utf8" "github.com/emersion/go-sasl" "gopkg.in/irc.v3" ) // permanentUpstreamCaps is the static list of upstream capabilities always // requested when supported. var permanentUpstreamCaps = map[string]bool{ "away-notify": true, "batch": true, "labeled-response": true, "message-tags": true, "multi-prefix": true, "server-time": true, } type upstreamChannel struct { Name string conn *upstreamConn Topic string TopicWho string TopicTime time.Time Status channelStatus modes channelModes creationTime string Members map[string]*memberships complete bool } type upstreamConn struct { conn network *network user *user serverName string availableUserModes string availableChannelModes map[byte]channelModeType availableChannelTypes string availableMemberships []membership registered bool nick string username string realname string modes userModes channels map[string]*upstreamChannel supportedCaps map[string]string caps map[string]bool batches map[string]batch away bool nextLabelID uint64 saslClient sasl.Client saslStarted bool // set of LIST commands in progress, per downstream pendingLISTDownstreamSet map[uint64]struct{} messageLoggers map[string]*messageLogger } func connectToUpstream(network *network) (*upstreamConn, error) { logger := &prefixLogger{network.user.srv.Logger, fmt.Sprintf("upstream %q: ", network.Addr)} var scheme string var addr string addrParts := strings.SplitN(network.Addr, "://", 2) if len(addrParts) == 2 { scheme = addrParts[0] addr = addrParts[1] } else { scheme = "ircs" addr = addrParts[0] } dialer := net.Dialer{Timeout: connectTimeout} var netConn net.Conn var err error switch scheme { case "ircs": if !strings.ContainsRune(addr, ':') { addr = addr + ":6697" } logger.Printf("connecting to TLS server at address %q", addr) var cfg *tls.Config if network.SASL.Mechanism == "EXTERNAL" { if network.SASL.External.CertBlob == nil { return nil, fmt.Errorf("missing certificate for authentication") } if network.SASL.External.PrivKeyBlob == nil { return nil, fmt.Errorf("missing private key for authentication") } key, err := x509.ParsePKCS8PrivateKey(network.SASL.External.PrivKeyBlob) if err != nil { return nil, fmt.Errorf("failed to parse private key: %v", err) } cfg = &tls.Config{ Certificates: []tls.Certificate{ { Certificate: [][]byte{network.SASL.External.CertBlob}, PrivateKey: key.(crypto.PrivateKey), }, }, } logger.Printf("using TLS client certificate %x", sha256.Sum256(network.SASL.External.CertBlob)) } netConn, err = tls.DialWithDialer(&dialer, "tcp", addr, cfg) case "irc+insecure": if !strings.ContainsRune(addr, ':') { addr = addr + ":6667" } logger.Printf("connecting to plain-text server at address %q", addr) netConn, err = dialer.Dial("tcp", addr) default: return nil, fmt.Errorf("failed to dial %q: unknown scheme: %v", addr, scheme) } if err != nil { return nil, fmt.Errorf("failed to dial %q: %v", addr, err) } uc := &upstreamConn{ conn: *newConn(network.user.srv, netConn, logger), network: network, user: network.user, channels: make(map[string]*upstreamChannel), supportedCaps: make(map[string]string), caps: make(map[string]bool), batches: make(map[string]batch), availableChannelTypes: stdChannelTypes, availableChannelModes: stdChannelModes, availableMemberships: stdMemberships, pendingLISTDownstreamSet: make(map[uint64]struct{}), messageLoggers: make(map[string]*messageLogger), } return uc, nil } func (uc *upstreamConn) forEachDownstream(f func(*downstreamConn)) { uc.network.forEachDownstream(f) } func (uc *upstreamConn) forEachDownstreamByID(id uint64, f func(*downstreamConn)) { uc.forEachDownstream(func(dc *downstreamConn) { if id != 0 && id != dc.id { return } f(dc) }) } func (uc *upstreamConn) getChannel(name string) (*upstreamChannel, error) { ch, ok := uc.channels[name] if !ok { return nil, fmt.Errorf("unknown channel %q", name) } return ch, nil } func (uc *upstreamConn) isChannel(entity string) bool { if i := strings.IndexByte(uc.availableChannelTypes, entity[0]); i >= 0 { return true } return false } func (uc *upstreamConn) getPendingLIST() *pendingLIST { for _, pl := range uc.user.pendingLISTs { if _, ok := pl.pendingCommands[uc.network.ID]; !ok { continue } return &pl } return nil } func (uc *upstreamConn) endPendingLISTs(all bool) (found bool) { found = false for i := 0; i < len(uc.user.pendingLISTs); i++ { pl := uc.user.pendingLISTs[i] if _, ok := pl.pendingCommands[uc.network.ID]; !ok { continue } delete(pl.pendingCommands, uc.network.ID) if len(pl.pendingCommands) == 0 { uc.user.pendingLISTs = append(uc.user.pendingLISTs[:i], uc.user.pendingLISTs[i+1:]...) i-- uc.forEachDownstreamByID(pl.downstreamID, func(dc *downstreamConn) { dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_LISTEND, Params: []string{dc.nick, "End of /LIST"}, }) }) } found = true if !all { delete(uc.pendingLISTDownstreamSet, pl.downstreamID) uc.user.forEachUpstream(func(uc *upstreamConn) { uc.trySendLIST(pl.downstreamID) }) return } } return } func (uc *upstreamConn) trySendLIST(downstreamID uint64) { if _, ok := uc.pendingLISTDownstreamSet[downstreamID]; ok { // a LIST command is already pending // we will try again when that command is completed return } for _, pl := range uc.user.pendingLISTs { if pl.downstreamID != downstreamID { continue } // this is the first pending LIST command list of the downstream listCommand, ok := pl.pendingCommands[uc.network.ID] if !ok { // there is no command for this upstream in these LIST commands // do not send anything continue } // there is a command for this upstream in these LIST commands // send it now uc.SendMessageLabeled(downstreamID, listCommand) uc.pendingLISTDownstreamSet[downstreamID] = struct{}{} return } } func (uc *upstreamConn) parseMembershipPrefix(s string) (ms *memberships, nick string) { memberships := make(memberships, 0, 4) i := 0 for _, m := range uc.availableMemberships { if i >= len(s) { break } if s[i] == m.Prefix { memberships = append(memberships, m) i++ } } return &memberships, s[i:] } func isWordBoundary(r rune) bool { switch r { case '-', '_', '|': return false case '\u00A0': return true default: return !unicode.IsLetter(r) && !unicode.IsNumber(r) } } func isHighlight(text, nick string) bool { for { i := strings.Index(text, nick) if i < 0 { return false } // Detect word boundaries var left, right rune if i > 0 { left, _ = utf8.DecodeLastRuneInString(text[:i]) } if i < len(text) { right, _ = utf8.DecodeRuneInString(text[i+len(nick):]) } if isWordBoundary(left) && isWordBoundary(right) { return true } text = text[i+len(nick):] } } func (uc *upstreamConn) handleMessage(msg *irc.Message) error { var label string if l, ok := msg.GetTag("label"); ok { label = l } var msgBatch *batch if batchName, ok := msg.GetTag("batch"); ok { b, ok := uc.batches[batchName] if !ok { return fmt.Errorf("unexpected batch reference: batch was not defined: %q", batchName) } msgBatch = &b if label == "" { label = msgBatch.Label } } var downstreamID uint64 = 0 if label != "" { var labelOffset uint64 n, err := fmt.Sscanf(label, "sd-%d-%d", &downstreamID, &labelOffset) if err == nil && n < 2 { err = errors.New("not enough arguments") } if err != nil { return fmt.Errorf("unexpected message label: invalid downstream reference for label %q: %v", label, err) } } if _, ok := msg.Tags["time"]; !ok { msg.Tags["time"] = irc.TagValue(time.Now().UTC().Format(serverTimeLayout)) } switch msg.Command { case "PING": uc.SendMessage(&irc.Message{ Command: "PONG", Params: msg.Params, }) return nil case "NOTICE", "PRIVMSG", "TAGMSG": if msg.Prefix == nil { return fmt.Errorf("expected a prefix") } var entity, text string if msg.Command != "TAGMSG" { if err := parseMessageParams(msg, &entity, &text); err != nil { return err } } else { if err := parseMessageParams(msg, &entity); err != nil { return err } } if msg.Prefix.Name == serviceNick { uc.logger.Printf("skipping %v from soju's service: %v", msg.Command, msg) break } if entity == serviceNick { uc.logger.Printf("skipping %v to soju's service: %v", msg.Command, msg) break } if msg.Prefix.User == "" && msg.Prefix.Host == "" { // server message uc.produce("", msg, nil) } else { // regular user message target := entity if target == uc.nick { target = msg.Prefix.Name } uc.produce(target, msg, nil) highlight := msg.Prefix.Name != uc.nick && isHighlight(text, uc.nick) if ch, ok := uc.network.channels[target]; ok && ch.Detached && highlight { uc.forEachDownstream(func(dc *downstreamConn) { sendServiceNOTICE(dc, fmt.Sprintf("highlight in %v: <%v> %v", dc.marshalEntity(uc.network, ch.Name), msg.Prefix.Name, text)) }) } } case "CAP": var subCmd string if err := parseMessageParams(msg, nil, &subCmd); err != nil { return err } subCmd = strings.ToUpper(subCmd) subParams := msg.Params[2:] switch subCmd { case "LS": if len(subParams) < 1 { return newNeedMoreParamsError(msg.Command) } caps := subParams[len(subParams)-1] more := len(subParams) >= 2 && msg.Params[len(subParams)-2] == "*" uc.handleSupportedCaps(caps) if more { break // wait to receive all capabilities } uc.requestCaps() if uc.requestSASL() { break // we'll send CAP END after authentication is completed } uc.SendMessage(&irc.Message{ Command: "CAP", Params: []string{"END"}, }) case "ACK", "NAK": if len(subParams) < 1 { return newNeedMoreParamsError(msg.Command) } caps := strings.Fields(subParams[0]) for _, name := range caps { if err := uc.handleCapAck(strings.ToLower(name), subCmd == "ACK"); err != nil { return err } } if uc.registered { uc.forEachDownstream(func(dc *downstreamConn) { dc.updateSupportedCaps() }) } case "NEW": if len(subParams) < 1 { return newNeedMoreParamsError(msg.Command) } uc.handleSupportedCaps(subParams[0]) uc.requestCaps() case "DEL": if len(subParams) < 1 { return newNeedMoreParamsError(msg.Command) } caps := strings.Fields(subParams[0]) for _, c := range caps { delete(uc.supportedCaps, c) delete(uc.caps, c) } if uc.registered { uc.forEachDownstream(func(dc *downstreamConn) { dc.updateSupportedCaps() }) } default: uc.logger.Printf("unhandled message: %v", msg) } case "AUTHENTICATE": if uc.saslClient == nil { return fmt.Errorf("received unexpected AUTHENTICATE message") } // TODO: if a challenge is 400 bytes long, buffer it var challengeStr string if err := parseMessageParams(msg, &challengeStr); err != nil { uc.SendMessage(&irc.Message{ Command: "AUTHENTICATE", Params: []string{"*"}, }) return err } var challenge []byte if challengeStr != "+" { var err error challenge, err = base64.StdEncoding.DecodeString(challengeStr) if err != nil { uc.SendMessage(&irc.Message{ Command: "AUTHENTICATE", Params: []string{"*"}, }) return err } } var resp []byte var err error if !uc.saslStarted { _, resp, err = uc.saslClient.Start() uc.saslStarted = true } else { resp, err = uc.saslClient.Next(challenge) } if err != nil { uc.SendMessage(&irc.Message{ Command: "AUTHENTICATE", Params: []string{"*"}, }) return err } // TODO: send response in multiple chunks if >= 400 bytes var respStr = "+" if resp != nil { respStr = base64.StdEncoding.EncodeToString(resp) } uc.SendMessage(&irc.Message{ Command: "AUTHENTICATE", Params: []string{respStr}, }) case irc.RPL_LOGGEDIN: var account string if err := parseMessageParams(msg, nil, nil, &account); err != nil { return err } uc.logger.Printf("logged in with account %q", account) case irc.RPL_LOGGEDOUT: uc.logger.Printf("logged out") case irc.ERR_NICKLOCKED, irc.RPL_SASLSUCCESS, irc.ERR_SASLFAIL, irc.ERR_SASLTOOLONG, irc.ERR_SASLABORTED: var info string if err := parseMessageParams(msg, nil, &info); err != nil { return err } switch msg.Command { case irc.ERR_NICKLOCKED: uc.logger.Printf("invalid nick used with SASL authentication: %v", info) case irc.ERR_SASLFAIL: uc.logger.Printf("SASL authentication failed: %v", info) case irc.ERR_SASLTOOLONG: uc.logger.Printf("SASL message too long: %v", info) } uc.saslClient = nil uc.saslStarted = false uc.SendMessage(&irc.Message{ Command: "CAP", Params: []string{"END"}, }) case irc.RPL_WELCOME: uc.registered = true uc.logger.Printf("connection registered") uc.forEachDownstream(func(dc *downstreamConn) { dc.updateSupportedCaps() }) if len(uc.network.channels) > 0 { // TODO: split this into multiple messages if need be var names, keys []string for _, ch := range uc.network.channels { names = append(names, ch.Name) keys = append(keys, ch.Key) } uc.SendMessage(&irc.Message{ Command: "JOIN", Params: []string{ strings.Join(names, ","), strings.Join(keys, ","), }, }) } case irc.RPL_MYINFO: if err := parseMessageParams(msg, nil, &uc.serverName, nil, &uc.availableUserModes, nil); err != nil { return err } case irc.RPL_ISUPPORT: if err := parseMessageParams(msg, nil, nil); err != nil { return err } for _, token := range msg.Params[1 : len(msg.Params)-1] { negate := false parameter := token value := "" if strings.HasPrefix(token, "-") { negate = true token = token[1:] } else { if i := strings.IndexByte(token, '='); i >= 0 { parameter = token[:i] value = token[i+1:] } } if !negate { switch parameter { case "CHANMODES": parts := strings.SplitN(value, ",", 5) if len(parts) < 4 { return fmt.Errorf("malformed ISUPPORT CHANMODES value: %v", value) } modes := make(map[byte]channelModeType) for i, mt := range []channelModeType{modeTypeA, modeTypeB, modeTypeC, modeTypeD} { for j := 0; j < len(parts[i]); j++ { mode := parts[i][j] modes[mode] = mt } } uc.availableChannelModes = modes case "CHANTYPES": uc.availableChannelTypes = value case "PREFIX": if value == "" { uc.availableMemberships = nil } else { if value[0] != '(' { return fmt.Errorf("malformed ISUPPORT PREFIX value: %v", value) } sep := strings.IndexByte(value, ')') if sep < 0 || len(value) != sep*2 { return fmt.Errorf("malformed ISUPPORT PREFIX value: %v", value) } memberships := make([]membership, len(value)/2-1) for i := range memberships { memberships[i] = membership{ Mode: value[i+1], Prefix: value[sep+i+1], } } uc.availableMemberships = memberships } } } else { // TODO: handle ISUPPORT negations } } case "BATCH": var tag string if err := parseMessageParams(msg, &tag); err != nil { return err } if strings.HasPrefix(tag, "+") { tag = tag[1:] if _, ok := uc.batches[tag]; ok { return fmt.Errorf("unexpected BATCH reference tag: batch was already defined: %q", tag) } var batchType string if err := parseMessageParams(msg, nil, &batchType); err != nil { return err } label := label if label == "" && msgBatch != nil { label = msgBatch.Label } uc.batches[tag] = batch{ Type: batchType, Params: msg.Params[2:], Outer: msgBatch, Label: label, } } else if strings.HasPrefix(tag, "-") { tag = tag[1:] if _, ok := uc.batches[tag]; !ok { return fmt.Errorf("unknown BATCH reference tag: %q", tag) } delete(uc.batches, tag) } else { return fmt.Errorf("unexpected BATCH reference tag: missing +/- prefix: %q", tag) } case "NICK": if msg.Prefix == nil { return fmt.Errorf("expected a prefix") } var newNick string if err := parseMessageParams(msg, &newNick); err != nil { return err } me := false if msg.Prefix.Name == uc.nick { uc.logger.Printf("changed nick from %q to %q", uc.nick, newNick) me = true uc.nick = newNick } for _, ch := range uc.channels { if memberships, ok := ch.Members[msg.Prefix.Name]; ok { delete(ch.Members, msg.Prefix.Name) ch.Members[newNick] = memberships uc.appendLog(ch.Name, msg) uc.appendHistory(ch.Name, msg) } } if !me { uc.forEachDownstream(func(dc *downstreamConn) { dc.SendMessage(dc.marshalMessage(msg, uc.network)) }) } else { uc.forEachDownstream(func(dc *downstreamConn) { dc.updateNick() }) } case "JOIN": if msg.Prefix == nil { return fmt.Errorf("expected a prefix") } var channels string if err := parseMessageParams(msg, &channels); err != nil { return err } for _, ch := range strings.Split(channels, ",") { if msg.Prefix.Name == uc.nick { uc.logger.Printf("joined channel %q", ch) uc.channels[ch] = &upstreamChannel{ Name: ch, conn: uc, Members: make(map[string]*memberships), } uc.SendMessage(&irc.Message{ Command: "MODE", Params: []string{ch}, }) } else { ch, err := uc.getChannel(ch) if err != nil { return err } ch.Members[msg.Prefix.Name] = &memberships{} } chMsg := msg.Copy() chMsg.Params[0] = ch uc.produce(ch, chMsg, nil) } case "PART": if msg.Prefix == nil { return fmt.Errorf("expected a prefix") } var channels string if err := parseMessageParams(msg, &channels); err != nil { return err } for _, ch := range strings.Split(channels, ",") { if msg.Prefix.Name == uc.nick { uc.logger.Printf("parted channel %q", ch) delete(uc.channels, ch) } else { ch, err := uc.getChannel(ch) if err != nil { return err } delete(ch.Members, msg.Prefix.Name) } chMsg := msg.Copy() chMsg.Params[0] = ch uc.produce(ch, chMsg, nil) } case "KICK": if msg.Prefix == nil { return fmt.Errorf("expected a prefix") } var channel, user string if err := parseMessageParams(msg, &channel, &user); err != nil { return err } if user == uc.nick { uc.logger.Printf("kicked from channel %q by %s", channel, msg.Prefix.Name) delete(uc.channels, channel) } else { ch, err := uc.getChannel(channel) if err != nil { return err } delete(ch.Members, user) } uc.produce(channel, msg, nil) case "QUIT": if msg.Prefix == nil { return fmt.Errorf("expected a prefix") } if msg.Prefix.Name == uc.nick { uc.logger.Printf("quit") } for _, ch := range uc.channels { if _, ok := ch.Members[msg.Prefix.Name]; ok { delete(ch.Members, msg.Prefix.Name) uc.appendLog(ch.Name, msg) uc.appendHistory(ch.Name, msg) } } if msg.Prefix.Name != uc.nick { uc.forEachDownstream(func(dc *downstreamConn) { dc.SendMessage(dc.marshalMessage(msg, uc.network)) }) } case irc.RPL_TOPIC, irc.RPL_NOTOPIC: var name, topic string if err := parseMessageParams(msg, nil, &name, &topic); err != nil { return err } ch, err := uc.getChannel(name) if err != nil { return err } if msg.Command == irc.RPL_TOPIC { ch.Topic = topic } else { ch.Topic = "" } case "TOPIC": var name string if err := parseMessageParams(msg, &name); err != nil { return err } ch, err := uc.getChannel(name) if err != nil { return err } if len(msg.Params) > 1 { ch.Topic = msg.Params[1] } else { ch.Topic = "" } uc.produce(ch.Name, msg, nil) case "MODE": var name, modeStr string if err := parseMessageParams(msg, &name, &modeStr); err != nil { return err } if !uc.isChannel(name) { // user mode change if name != uc.nick { return fmt.Errorf("received MODE message for unknown nick %q", name) } return uc.modes.Apply(modeStr) // TODO: notify downstreams about user mode change? } else { // channel mode change ch, err := uc.getChannel(name) if err != nil { return err } needMarshaling, err := applyChannelModes(ch, modeStr, msg.Params[2:]) if err != nil { return err } uc.appendLog(ch.Name, msg) uc.forEachDownstream(func(dc *downstreamConn) { params := make([]string, len(msg.Params)) params[0] = dc.marshalEntity(uc.network, name) params[1] = modeStr copy(params[2:], msg.Params[2:]) for i, modeParam := range params[2:] { if _, ok := needMarshaling[i]; ok { params[2+i] = dc.marshalEntity(uc.network, modeParam) } } dc.SendMessage(&irc.Message{ Prefix: dc.marshalUserPrefix(uc.network, msg.Prefix), Command: "MODE", Params: params, }) }) } case irc.RPL_UMODEIS: if err := parseMessageParams(msg, nil); err != nil { return err } modeStr := "" if len(msg.Params) > 1 { modeStr = msg.Params[1] } uc.modes = "" if err := uc.modes.Apply(modeStr); err != nil { return err } // TODO: send RPL_UMODEIS to downstream connections when applicable case irc.RPL_CHANNELMODEIS: var channel string if err := parseMessageParams(msg, nil, &channel); err != nil { return err } modeStr := "" if len(msg.Params) > 2 { modeStr = msg.Params[2] } ch, err := uc.getChannel(channel) if err != nil { return err } firstMode := ch.modes == nil ch.modes = make(map[byte]string) if _, err := applyChannelModes(ch, modeStr, msg.Params[3:]); err != nil { return err } if firstMode { modeStr, modeParams := ch.modes.Format() uc.forEachDownstream(func(dc *downstreamConn) { params := []string{dc.nick, dc.marshalEntity(uc.network, channel), modeStr} params = append(params, modeParams...) dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_CHANNELMODEIS, Params: params, }) }) } case rpl_creationtime: var channel, creationTime string if err := parseMessageParams(msg, nil, &channel, &creationTime); err != nil { return err } ch, err := uc.getChannel(channel) if err != nil { return err } firstCreationTime := ch.creationTime == "" ch.creationTime = creationTime if firstCreationTime { uc.forEachDownstream(func(dc *downstreamConn) { dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: rpl_creationtime, Params: []string{dc.nick, channel, creationTime}, }) }) } case rpl_topicwhotime: var name, who, timeStr string if err := parseMessageParams(msg, nil, &name, &who, &timeStr); err != nil { return err } ch, err := uc.getChannel(name) if err != nil { return err } ch.TopicWho = who sec, err := strconv.ParseInt(timeStr, 10, 64) if err != nil { return fmt.Errorf("failed to parse topic time: %v", err) } ch.TopicTime = time.Unix(sec, 0) case irc.RPL_LIST: var channel, clients, topic string if err := parseMessageParams(msg, nil, &channel, &clients, &topic); err != nil { return err } pl := uc.getPendingLIST() if pl == nil { return fmt.Errorf("unexpected RPL_LIST: no matching pending LIST") } uc.forEachDownstreamByID(pl.downstreamID, func(dc *downstreamConn) { dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_LIST, Params: []string{dc.nick, dc.marshalEntity(uc.network, channel), clients, topic}, }) }) case irc.RPL_LISTEND: ok := uc.endPendingLISTs(false) if !ok { return fmt.Errorf("unexpected RPL_LISTEND: no matching pending LIST") } case irc.RPL_NAMREPLY: var name, statusStr, members string if err := parseMessageParams(msg, nil, &statusStr, &name, &members); err != nil { return err } ch, ok := uc.channels[name] if !ok { // NAMES on a channel we have not joined, forward to downstream uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { channel := dc.marshalEntity(uc.network, name) members := splitSpace(members) for i, member := range members { memberships, nick := uc.parseMembershipPrefix(member) members[i] = memberships.Format(dc) + dc.marshalEntity(uc.network, nick) } memberStr := strings.Join(members, " ") dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_NAMREPLY, Params: []string{dc.nick, statusStr, channel, memberStr}, }) }) return nil } status, err := parseChannelStatus(statusStr) if err != nil { return err } ch.Status = status for _, s := range splitSpace(members) { memberships, nick := uc.parseMembershipPrefix(s) ch.Members[nick] = memberships } case irc.RPL_ENDOFNAMES: var name string if err := parseMessageParams(msg, nil, &name); err != nil { return err } ch, ok := uc.channels[name] if !ok { // NAMES on a channel we have not joined, forward to downstream uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { channel := dc.marshalEntity(uc.network, name) dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_ENDOFNAMES, Params: []string{dc.nick, channel, "End of /NAMES list"}, }) }) return nil } if ch.complete { return fmt.Errorf("received unexpected RPL_ENDOFNAMES") } ch.complete = true uc.forEachDownstream(func(dc *downstreamConn) { forwardChannel(dc, ch) }) case irc.RPL_WHOREPLY: var channel, username, host, server, nick, mode, trailing string if err := parseMessageParams(msg, nil, &channel, &username, &host, &server, &nick, &mode, &trailing); err != nil { return err } parts := strings.SplitN(trailing, " ", 2) if len(parts) != 2 { return fmt.Errorf("received malformed RPL_WHOREPLY: wrong trailing parameter: %s", trailing) } realname := parts[1] hops, err := strconv.Atoi(parts[0]) if err != nil { return fmt.Errorf("received malformed RPL_WHOREPLY: wrong hop count: %s", parts[0]) } hops++ trailing = strconv.Itoa(hops) + " " + realname uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { channel := channel if channel != "*" { channel = dc.marshalEntity(uc.network, channel) } nick := dc.marshalEntity(uc.network, nick) dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_WHOREPLY, Params: []string{dc.nick, channel, username, host, server, nick, mode, trailing}, }) }) case irc.RPL_ENDOFWHO: var name string if err := parseMessageParams(msg, nil, &name); err != nil { return err } uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { name := name if name != "*" { // TODO: support WHO masks name = dc.marshalEntity(uc.network, name) } dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_ENDOFWHO, Params: []string{dc.nick, name, "End of /WHO list"}, }) }) case irc.RPL_WHOISUSER: var nick, username, host, realname string if err := parseMessageParams(msg, nil, &nick, &username, &host, nil, &realname); err != nil { return err } uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { nick := dc.marshalEntity(uc.network, nick) dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_WHOISUSER, Params: []string{dc.nick, nick, username, host, "*", realname}, }) }) case irc.RPL_WHOISSERVER: var nick, server, serverInfo string if err := parseMessageParams(msg, nil, &nick, &server, &serverInfo); err != nil { return err } uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { nick := dc.marshalEntity(uc.network, nick) dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_WHOISSERVER, Params: []string{dc.nick, nick, server, serverInfo}, }) }) case irc.RPL_WHOISOPERATOR: var nick string if err := parseMessageParams(msg, nil, &nick); err != nil { return err } uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { nick := dc.marshalEntity(uc.network, nick) dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_WHOISOPERATOR, Params: []string{dc.nick, nick, "is an IRC operator"}, }) }) case irc.RPL_WHOISIDLE: var nick string if err := parseMessageParams(msg, nil, &nick, nil); err != nil { return err } uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { nick := dc.marshalEntity(uc.network, nick) params := []string{dc.nick, nick} params = append(params, msg.Params[2:]...) dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_WHOISIDLE, Params: params, }) }) case irc.RPL_WHOISCHANNELS: var nick, channelList string if err := parseMessageParams(msg, nil, &nick, &channelList); err != nil { return err } channels := splitSpace(channelList) uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { nick := dc.marshalEntity(uc.network, nick) channelList := make([]string, len(channels)) for i, channel := range channels { prefix, channel := uc.parseMembershipPrefix(channel) channel = dc.marshalEntity(uc.network, channel) channelList[i] = prefix.Format(dc) + channel } channels := strings.Join(channelList, " ") dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_WHOISCHANNELS, Params: []string{dc.nick, nick, channels}, }) }) case irc.RPL_ENDOFWHOIS: var nick string if err := parseMessageParams(msg, nil, &nick); err != nil { return err } uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { nick := dc.marshalEntity(uc.network, nick) dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_ENDOFWHOIS, Params: []string{dc.nick, nick, "End of /WHOIS list"}, }) }) case "INVITE": var nick, channel string if err := parseMessageParams(msg, &nick, &channel); err != nil { return err } uc.forEachDownstream(func(dc *downstreamConn) { dc.SendMessage(&irc.Message{ Prefix: dc.marshalUserPrefix(uc.network, msg.Prefix), Command: "INVITE", Params: []string{dc.marshalEntity(uc.network, nick), dc.marshalEntity(uc.network, channel)}, }) }) case irc.RPL_INVITING: var nick, channel string if err := parseMessageParams(msg, nil, &nick, &channel); err != nil { return err } uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_INVITING, Params: []string{dc.nick, dc.marshalEntity(uc.network, nick), dc.marshalEntity(uc.network, channel)}, }) }) case irc.RPL_AWAY: var nick, reason string if err := parseMessageParams(msg, nil, &nick, &reason); err != nil { return err } uc.forEachDownstream(func(dc *downstreamConn) { dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: irc.RPL_AWAY, Params: []string{dc.nick, dc.marshalEntity(uc.network, nick), reason}, }) }) case "AWAY": if msg.Prefix == nil { return fmt.Errorf("expected a prefix") } uc.forEachDownstream(func(dc *downstreamConn) { if !dc.caps["away-notify"] { return } dc.SendMessage(&irc.Message{ Prefix: dc.marshalUserPrefix(uc.network, msg.Prefix), Command: "AWAY", Params: msg.Params, }) }) case irc.RPL_BANLIST, irc.RPL_INVITELIST, irc.RPL_EXCEPTLIST: var channel, mask string if err := parseMessageParams(msg, nil, &channel, &mask); err != nil { return err } var addNick, addTime string if len(msg.Params) >= 5 { addNick = msg.Params[3] addTime = msg.Params[4] } uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { channel := dc.marshalEntity(uc.network, channel) var params []string if addNick != "" && addTime != "" { addNick := dc.marshalEntity(uc.network, addNick) params = []string{dc.nick, channel, mask, addNick, addTime} } else { params = []string{dc.nick, channel, mask} } dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: msg.Command, Params: params, }) }) case irc.RPL_ENDOFBANLIST, irc.RPL_ENDOFINVITELIST, irc.RPL_ENDOFEXCEPTLIST: var channel, trailing string if err := parseMessageParams(msg, nil, &channel, &trailing); err != nil { return err } uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { upstreamChannel := dc.marshalEntity(uc.network, channel) dc.SendMessage(&irc.Message{ Prefix: dc.srv.prefix(), Command: msg.Command, Params: []string{dc.nick, upstreamChannel, trailing}, }) }) case irc.ERR_UNKNOWNCOMMAND, irc.RPL_TRYAGAIN: var command, reason string if err := parseMessageParams(msg, nil, &command, &reason); err != nil { return err } if command == "LIST" { ok := uc.endPendingLISTs(false) if !ok { return fmt.Errorf("unexpected response for LIST: %q: no matching pending LIST", msg.Command) } } if downstreamID != 0 { uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { dc.SendMessage(&irc.Message{ Prefix: uc.srv.prefix(), Command: msg.Command, Params: []string{dc.nick, command, reason}, }) }) } case "ACK": // Ignore case irc.RPL_NOWAWAY, irc.RPL_UNAWAY: // Ignore case irc.RPL_YOURHOST, irc.RPL_CREATED: // Ignore case irc.RPL_LUSERCLIENT, irc.RPL_LUSEROP, irc.RPL_LUSERUNKNOWN, irc.RPL_LUSERCHANNELS, irc.RPL_LUSERME: // Ignore case irc.RPL_MOTDSTART, irc.RPL_MOTD, irc.RPL_ENDOFMOTD: // Ignore case irc.RPL_LISTSTART: // Ignore case rpl_localusers, rpl_globalusers: // Ignore case irc.RPL_STATSVLINE, rpl_statsping, irc.RPL_STATSBLINE, irc.RPL_STATSDLINE: // Ignore default: uc.logger.Printf("unhandled message: %v", msg) if downstreamID != 0 { uc.forEachDownstreamByID(downstreamID, func(dc *downstreamConn) { // best effort marshaling for unknown messages, replies and errors: // most numerics start with the user nick, marshal it if that's the case // otherwise, conservately keep the params without marshaling params := msg.Params if _, err := strconv.Atoi(msg.Command); err == nil { // numeric if len(msg.Params) > 0 && isOurNick(uc.network, msg.Params[0]) { params[0] = dc.nick } } dc.SendMessage(&irc.Message{ Prefix: uc.srv.prefix(), Command: msg.Command, Params: params, }) }) } } return nil } func (uc *upstreamConn) handleSupportedCaps(capsStr string) { caps := strings.Fields(capsStr) for _, s := range caps { kv := strings.SplitN(s, "=", 2) k := strings.ToLower(kv[0]) var v string if len(kv) == 2 { v = kv[1] } uc.supportedCaps[k] = v } } func (uc *upstreamConn) requestCaps() { var requestCaps []string for c := range permanentUpstreamCaps { if _, ok := uc.supportedCaps[c]; ok && !uc.caps[c] { requestCaps = append(requestCaps, c) } } if uc.requestSASL() && !uc.caps["sasl"] { requestCaps = append(requestCaps, "sasl") } if len(requestCaps) == 0 { return } uc.SendMessage(&irc.Message{ Command: "CAP", Params: []string{"REQ", strings.Join(requestCaps, " ")}, }) } func (uc *upstreamConn) requestSASL() bool { if uc.network.SASL.Mechanism == "" { return false } v, ok := uc.supportedCaps["sasl"] if !ok { return false } if v != "" { mechanisms := strings.Split(v, ",") found := false for _, mech := range mechanisms { if strings.EqualFold(mech, uc.network.SASL.Mechanism) { found = true break } } if !found { return false } } return true } func (uc *upstreamConn) handleCapAck(name string, ok bool) error { uc.caps[name] = ok switch name { case "sasl": if !ok { uc.logger.Printf("server refused to acknowledge the SASL capability") return nil } auth := &uc.network.SASL switch auth.Mechanism { case "PLAIN": uc.logger.Printf("starting SASL PLAIN authentication with username %q", auth.Plain.Username) uc.saslClient = sasl.NewPlainClient("", auth.Plain.Username, auth.Plain.Password) case "EXTERNAL": uc.logger.Printf("starting SASL EXTERNAL authentication") uc.saslClient = sasl.NewExternalClient("") default: return fmt.Errorf("unsupported SASL mechanism %q", name) } uc.SendMessage(&irc.Message{ Command: "AUTHENTICATE", Params: []string{auth.Mechanism}, }) default: if permanentUpstreamCaps[name] { break } uc.logger.Printf("received CAP ACK/NAK for a cap we don't support: %v", name) } return nil } func splitSpace(s string) []string { return strings.FieldsFunc(s, func(r rune) bool { return r == ' ' }) } func (uc *upstreamConn) register() { uc.nick = uc.network.Nick uc.username = uc.network.Username if uc.username == "" { uc.username = uc.nick } uc.realname = uc.network.Realname if uc.realname == "" { uc.realname = uc.nick } uc.SendMessage(&irc.Message{ Command: "CAP", Params: []string{"LS", "302"}, }) if uc.network.Pass != "" { uc.SendMessage(&irc.Message{ Command: "PASS", Params: []string{uc.network.Pass}, }) } uc.SendMessage(&irc.Message{ Command: "NICK", Params: []string{uc.nick}, }) uc.SendMessage(&irc.Message{ Command: "USER", Params: []string{uc.username, "0", "*", uc.realname}, }) } func (uc *upstreamConn) runUntilRegistered() error { for !uc.registered { msg, err := uc.ReadMessage() if err != nil { return fmt.Errorf("failed to read message: %v", err) } if err := uc.handleMessage(msg); err != nil { return fmt.Errorf("failed to handle message %q: %v", msg, err) } } for _, command := range uc.network.ConnectCommands { m, err := irc.ParseMessage(command) if err != nil { uc.logger.Printf("failed to parse connect command %q: %v", command, err) } else { uc.SendMessage(m) } } return nil } func (uc *upstreamConn) readMessages(ch chan<- event) error { for { msg, err := uc.ReadMessage() if err == io.EOF { break } else if err != nil { return fmt.Errorf("failed to read IRC command: %v", err) } ch <- eventUpstreamMessage{msg, uc} } return nil } func (uc *upstreamConn) SendMessage(msg *irc.Message) { if !uc.caps["message-tags"] { msg = msg.Copy() msg.Tags = nil } uc.conn.SendMessage(msg) } func (uc *upstreamConn) SendMessageLabeled(downstreamID uint64, msg *irc.Message) { if uc.caps["labeled-response"] { if msg.Tags == nil { msg.Tags = make(map[string]irc.TagValue) } msg.Tags["label"] = irc.TagValue(fmt.Sprintf("sd-%d-%d", downstreamID, uc.nextLabelID)) uc.nextLabelID++ } uc.SendMessage(msg) } // TODO: handle moving logs when a network name changes, when support for this is added func (uc *upstreamConn) appendLog(entity string, msg *irc.Message) { if uc.srv.LogPath == "" { return } ml, ok := uc.messageLoggers[entity] if !ok { ml = newMessageLogger(uc.network, entity) uc.messageLoggers[entity] = ml } if err := ml.Append(msg); err != nil { uc.logger.Printf("failed to log message: %v", err) } } // appendHistory appends a message to the history. entity can be empty. func (uc *upstreamConn) appendHistory(entity string, msg *irc.Message) { detached := false if ch, ok := uc.network.channels[entity]; ok { detached = ch.Detached } // If no client is offline, no need to append the message to the buffer if len(uc.network.offlineClients) == 0 && !detached { return } history, ok := uc.network.history[entity] if !ok { history = &networkHistory{ offlineClients: make(map[string]uint64), ring: NewRing(uc.srv.RingCap), } uc.network.history[entity] = history for clientName, _ := range uc.network.offlineClients { history.offlineClients[clientName] = 0 } if detached { // If the channel is detached, online clients act as offline // clients too uc.forEachDownstream(func(dc *downstreamConn) { history.offlineClients[dc.clientName] = 0 }) } } history.ring.Produce(msg) } // produce appends a message to the logs, adds it to the history and forwards // it to connected downstream connections. // // If origin is not nil and origin doesn't support echo-message, the message is // forwarded to all connections except origin. func (uc *upstreamConn) produce(target string, msg *irc.Message, origin *downstreamConn) { if target != "" { uc.appendLog(target, msg) } uc.appendHistory(target, msg) // Don't forward messages if it's a detached channel if ch, ok := uc.network.channels[target]; ok && ch.Detached { return } uc.forEachDownstream(func(dc *downstreamConn) { if dc != origin || dc.caps["echo-message"] { dc.SendMessage(dc.marshalMessage(msg, uc.network)) } }) } func (uc *upstreamConn) updateAway() { away := true uc.forEachDownstream(func(*downstreamConn) { away = false }) if away == uc.away { return } if away { uc.SendMessage(&irc.Message{ Command: "AWAY", Params: []string{"Auto away"}, }) } else { uc.SendMessage(&irc.Message{ Command: "AWAY", }) } uc.away = away }