600 lines
15 KiB
Go
600 lines
15 KiB
Go
package main
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/*
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Copyright (C) 2016 The `nmdc-ircfrontend' author(s)
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Copyright (C) 2013 Harry Jeffery
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU Affero General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Affero General Public License for more details.
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You should have received a copy of the GNU Affero General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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import (
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"bytes"
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"fmt"
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"io"
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"libnmdc"
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"log"
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"net"
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"strings"
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"time"
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)
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type ClientState int
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const (
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CSUnregistered ClientState = iota
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CSRegistered
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CSJoined
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)
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type Server struct {
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name string
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motd string
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clientConn net.Conn
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clientState ClientState
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upstreamLauncher libnmdc.HubConnectionOptions
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upstreamCloser chan struct{}
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upstream *libnmdc.HubConnection
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verbose bool
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autojoin bool
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lastMessage string // FIXME racey
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}
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func NewServer(name string, upstream libnmdc.HubAddress, conn net.Conn) *Server {
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self := libnmdc.NewUserInfo("")
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self.ClientTag = APP_DESCRIPTION
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return &Server{
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name: name,
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clientConn: conn,
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clientState: CSUnregistered,
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motd: "Connected to " + name + ". You /must/ join " + BLESSED_CHANNEL + " to continue.",
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upstreamLauncher: libnmdc.HubConnectionOptions{
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Address: upstream,
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Self: *self,
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},
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upstreamCloser: make(chan struct{}, 1),
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}
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}
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func (s *Server) verboseln(line string) {
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if s.verbose {
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log.Println(line)
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}
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}
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func (s *Server) verbosef(fmt string, args ...interface{}) {
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if s.verbose {
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log.Printf(fmt, args...)
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}
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}
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func (s *Server) RunWorker() {
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// Send the connection handshake.
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// Can't connect to the upstream server yet, until we've recieved a nick.
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s.sendMOTD(s.motd)
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for {
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if s.clientConn == nil {
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break // abandon thread
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}
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buf := make([]byte, CLIENT_READ_BUFFSIZE)
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ln, err := s.clientConn.Read(buf)
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if err != nil {
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if err == io.EOF {
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break // abandon thread
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}
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// If this was a /timeout/, send a KA and continue.
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// But otherwise, it was a real error (e.g. unexpected disconnect)
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s.verboseln(err.Error())
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break // abandon
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}
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rawLines := buf[:ln]
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rawLines = bytes.Replace(rawLines, []byte("\r\n"), []byte("\n"), -1)
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rawLines = bytes.Replace(rawLines, []byte("\r"), []byte("\n"), -1)
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lines := bytes.Split(rawLines, []byte("\n"))
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for _, line := range lines {
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if len(line) > 0 {
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// Client sent a command
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fields := strings.Fields(string(line))
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if len(fields) < 1 {
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return
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}
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if strings.HasPrefix(fields[0], ":") {
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fields = fields[1:]
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}
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s.handleCommand(strings.ToUpper(fields[0]), fields[1:])
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}
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}
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}
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s.verboseln("Broken loop.")
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// Cleanup upstream
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if s.upstream != nil {
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s.upstreamCloser <- struct{}{} // always safe to do this /once/
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}
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// Clean up ourselves
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s.DisconnectClient() // if not already done
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}
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func (s *Server) upstreamWorker() {
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var BLANK_NICK = "PtokaX" // "\xC2\xA0"
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// Read loop
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for {
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select {
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case <-s.upstreamCloser:
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// Abandon the upstream connection
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s.verboseln("Abandoning upstream connection...")
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s.upstream.Disconnect()
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return
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case hubEvent := <-s.upstream.OnEvent:
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switch hubEvent.EventType {
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case libnmdc.EVENT_USER_JOINED:
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s.reply(rplJoin, hubEvent.Nick, BLESSED_CHANNEL)
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case libnmdc.EVENT_USER_PART:
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s.reply(rplPart, hubEvent.Nick, BLESSED_CHANNEL, "Disconnected")
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case libnmdc.EVENT_USER_UPDATED_INFO:
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// description change - no relevance for IRC users
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case libnmdc.EVENT_CONNECTION_STATE_CHANGED:
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s.reply(rplMsg, BLANK_NICK, BLESSED_CHANNEL, "* Upstream: "+hubEvent.StateChange.Format())
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case libnmdc.EVENT_HUBNAME_CHANGED:
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s.sendChannelTopic(hubEvent.Nick)
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case libnmdc.EVENT_PRIVATE:
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s.reply(rplMsg, hubEvent.Nick, s.upstreamLauncher.Self.Nick, hubEvent.Message)
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case libnmdc.EVENT_PUBLIC:
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if hubEvent.Nick == s.upstreamLauncher.Self.Nick && hubEvent.Message == s.lastMessage {
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s.lastMessage = "" // irc doesn't echo our own pubchat
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} else {
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s.reply(rplMsg, hubEvent.Nick, BLESSED_CHANNEL, hubEvent.Message)
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}
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case libnmdc.EVENT_SYSTEM_MESSAGE_FROM_CONN, libnmdc.EVENT_SYSTEM_MESSAGE_FROM_HUB:
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// FIXME blank names work well in hexchat, but not in yaaic
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s.reply(rplMsg, BLANK_NICK, BLESSED_CHANNEL, hubEvent.Message)
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}
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}
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}
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}
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func (s *Server) handleCommand(command string, args []string) {
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s.verbosef(" >>> '%s' %v", command, args)
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switch command {
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case "PING":
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s.reply(rplPong)
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case "PONG":
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// do nothing
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case "INFO":
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s.reply(rplInfo, APP_DESCRIPTION)
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case "VERSION":
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s.reply(rplVersion, VERSION)
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case "MOTD":
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s.sendMOTD(s.motd)
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case "CAP":
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return
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/*
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if len(args) < 1 {
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s.reply(errMoreArgs)
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return
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}
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if args[0] == "LS" {
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s.writeClient("CAP * LS :nmdc-ircfrontend") // no special IRCv3 capabilities available
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} else {
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s.writeClient(fmt.Sprintf(":%s 410 * %s :Invalid CAP command", s.name, args[0]))
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}
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*/
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case "PASS":
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// RFC2812 registration. Stash the password for later
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if len(args) < 1 {
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s.reply(errMoreArgs)
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return
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}
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s.upstreamLauncher.NickPassword = args[0]
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case "NICK":
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if len(args) < 1 {
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s.reply(errMoreArgs)
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return
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}
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if s.upstreamLauncher.Self.Nick == "" {
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// allow set, as part of the login phase
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s.upstreamLauncher.Self.Nick = args[0]
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} else {
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s.reply(rplKill, "Can't change nicks on this server", "")
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s.DisconnectClient()
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}
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case "USER":
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// This command sets altname, realname, ... none of which we use
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// It's the final step in a PASS/NICK/USER login handshake.
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if s.clientState != CSUnregistered {
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s.reply(rplKill, "You're already registered.", "")
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s.DisconnectClient()
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return
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}
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if s.upstreamLauncher.Self.Nick == "" {
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s.reply(rplKill, "Your nickname is already being used", "")
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s.DisconnectClient()
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return
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}
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s.reply(rplWelcome)
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s.clientState = CSRegistered
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// TODO tell the client that they /must/ join #chat
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if s.autojoin {
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s.handleCommand("JOIN", []string{BLESSED_CHANNEL})
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}
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// Send a CTCP VERSION request to the client. If the IRC client can
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// supply a client version string, we can replace our tag with it,
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// but that's optional
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default:
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s.handleRegisteredCommand(command, args)
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}
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}
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func (s *Server) handleRegisteredCommand(command string, args []string) {
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if s.clientState == CSUnregistered {
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s.reply(errNotReg)
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return
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}
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switch command {
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case "JOIN":
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if len(args) < 1 {
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s.reply(errMoreArgs)
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return
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}
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switch args[0] {
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case BLESSED_CHANNEL:
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if s.clientState != CSJoined {
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// Join for the first time
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s.clientState = CSJoined
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// Acknowledge
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s.reply(rplJoin, s.upstreamLauncher.Self.Nick, BLESSED_CHANNEL)
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// Send (initially just us) nicklist for the chat channel
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s.sendNames()
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// Spawn upstream connection
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s.upstream = s.upstreamLauncher.Connect()
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go s.upstreamWorker()
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} else {
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// They're already here, ignore
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// Can happen if autojoin is enabled but the client already requested a login
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}
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case "0":
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// Quitting all channels? Drop client
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s.reply(rplKill, "Bye.", "")
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s.DisconnectClient()
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default:
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s.reply(rplKill, "There is only '"+BLESSED_CHANNEL+"'.", "")
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s.DisconnectClient()
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}
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case "PART":
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if len(args) < 1 {
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s.reply(errMoreArgs)
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return
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}
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if args[0] == BLESSED_CHANNEL {
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// You can check out any time you like, but you can never leave
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s.reply(rplJoin, s.upstreamLauncher.Self.Nick, BLESSED_CHANNEL)
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s.sendNames()
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}
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case "PRIVMSG", "NOTICE":
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if len(args) < 2 {
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s.reply(errMoreArgs)
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return
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}
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if s.upstream == nil || s.upstream.State != libnmdc.CONNECTIONSTATE_CONNECTED {
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s.reply(errCannotSend, args[0])
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return
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}
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message := strings.Join(args[1:], " ")[1:] // strip leading colon
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// IRC is case-insensitive case-preserving. We can respect that for the
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// channel name, but not really for user nicks
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if strings.ToLower(args[0]) == BLESSED_CHANNEL {
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s.lastMessage = message
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s.upstream.SayPublic(s.lastMessage)
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} else if _, clientExists := s.upstream.Users[args[0]]; clientExists {
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s.upstream.SayPrivate(args[0], message)
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} else {
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s.reply(errNoSuchNick, args[0])
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}
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case "QUIT":
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s.DisconnectClient()
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case "TOPIC":
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if len(args) < 1 {
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s.reply(errMoreArgs)
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return
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}
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if strings.ToLower(args[0]) != BLESSED_CHANNEL {
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s.reply(errNoSuchNick, args[0])
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return
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}
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if len(args) == 1 {
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s.sendChannelTopic(s.upstream.HubName) // Valid topic get
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} else {
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s.reply(errNoPriv) // Disallow topic set
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}
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case "LIST":
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listItem := fmt.Sprintf("%s %d :%s", BLESSED_CHANNEL, len(s.upstream.Users), s.upstream.HubName)
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s.reply(rplList, listItem)
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s.reply(rplListEnd)
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case "OPER":
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if len(args) < 2 {
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s.reply(errMoreArgs)
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return
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}
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// Can't use this command.
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s.reply(errPassword)
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case "KILL", "KICK":
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s.reply(errNoPriv)
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return
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case "WHO":
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if len(args) < 1 {
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s.reply(errMoreArgs)
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return
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}
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// Ignore what we're "supposed" to do
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s.sendNames()
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/*
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if args[0] == BLESSED_CHANNEL {
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// always include ourselves
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s.reply(rplWho, s.upstreamLauncher.Self.Nick, args[0])
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for nick, _ := range s.upstream.Users {
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if nick != s.upstreamLauncher.Self.Nick { // but don't repeat ourselves
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s.reply(rplWho, nick, args[0])
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}
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}
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} else {
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// argument is a filter
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for nick, _ := range s.upstream.Users {
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if strings.Contains(nick, args[0]) {
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s.reply(rplWho, nick, args[0])
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}
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}
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}
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s.reply(rplEndOfWho, args[0])
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*/
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case "MODE":
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if len(args) < 1 {
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s.reply(errMoreArgs)
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return
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}
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if strings.ToLower(args[0]) != BLESSED_CHANNEL {
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s.reply(errNoSuchNick, args[0])
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return
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}
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if len(args) == 1 {
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// No more args, they just want the mode
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s.reply(rplChannelModeIs, args[0], BLESSED_CHANNEL_MODE, "")
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} else {
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// Setting modes is disallowed
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s.reply(errNoPriv)
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}
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return
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default:
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s.reply(errUnknownCommand, command)
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}
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}
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func (s *Server) DisconnectClient() {
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if s.clientConn != nil {
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s.clientConn.Close()
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}
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s.clientConn = nil
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s.clientState = CSUnregistered
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// Readloop will stop, which kills the upstream connection too
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}
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func (s *Server) sendNames() {
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names := s.upstreamLauncher.Self.Nick
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if s.upstream != nil {
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for nick, _ := range s.upstream.Users {
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names += " " + nick
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}
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}
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s.reply(rplNames, BLESSED_CHANNEL, names)
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s.reply(rplEndOfNames, BLESSED_CHANNEL)
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}
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func (s *Server) sendChannelTopic(topic string) {
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if len(topic) > 0 {
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s.reply(rplTopic, BLESSED_CHANNEL, s.upstream.HubName)
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} else {
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s.reply(rplNoTopic, BLESSED_CHANNEL)
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}
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}
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func (s *Server) sendMOTD(motd string) {
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s.reply(rplMOTDStart)
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for len(motd) > 80 {
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s.reply(rplMOTD, motd[:80])
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motd = motd[80:]
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}
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if len(motd) > 0 {
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s.reply(rplMOTD, motd)
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}
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s.reply(rplEndOfMOTD)
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}
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// Send a reply to a user with the code specified
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func (s *Server) reply(code replyCode, args ...string) {
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switch code {
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case rplWelcome:
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s.writeClient(fmt.Sprintf(":%s 001 %s :Welcome to %s", s.name, s.upstreamLauncher.Self.Nick, s.name))
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case rplJoin:
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s.writeClient(fmt.Sprintf(":%s JOIN %s", args[0], args[1]))
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case rplPart:
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s.writeClient(fmt.Sprintf(":%s PART %s %s", args[0], args[1], args[2]))
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case rplTopic:
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s.writeClient(fmt.Sprintf(":%s 332 %s %s :%s", s.name, s.upstreamLauncher.Self.Nick, args[0], args[1]))
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case rplNoTopic:
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s.writeClient(fmt.Sprintf(":%s 331 %s %s :No topic is set", s.name, s.upstreamLauncher.Self.Nick, args[0]))
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case rplNames:
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s.writeClient(fmt.Sprintf(":%s 353 %s = %s :%s", s.name, s.upstreamLauncher.Self.Nick, args[0], args[1]))
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case rplEndOfNames:
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s.writeClient(fmt.Sprintf(":%s 366 %s %s :End of NAMES list", s.name, s.upstreamLauncher.Self.Nick, args[0]))
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case rplWho:
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s.writeClient(fmt.Sprintf(":%s 352 %s %s %s %s %s %s H :0 %s", s.name, s.upstreamLauncher.Self.Nick, args[1], args[0], args[0], s.name, args[0], args[0]))
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case rplEndOfWho:
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s.writeClient(fmt.Sprintf(":%s 315 %s %s :End of WHO list", s.name, s.upstreamLauncher.Self.Nick, args[0]))
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case rplNickChange:
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s.writeClient(fmt.Sprintf(":%s NICK %s", args[0], args[1]))
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case rplKill:
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s.writeClient(fmt.Sprintf(":%s KILL %s A %s", args[0], s.upstreamLauncher.Self.Nick, args[1]))
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case rplMsg:
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for _, itm := range strings.Split(args[2], "\n") {
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s.writeClient(fmt.Sprintf(":%s PRIVMSG %s %s", args[0], args[1], itm))
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}
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case rplList:
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s.writeClient(fmt.Sprintf(":%s 322 %s %s", s.name, s.upstreamLauncher.Self.Nick, args[0]))
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case rplListEnd:
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s.writeClient(fmt.Sprintf(":%s 323 %s", s.name, s.upstreamLauncher.Self.Nick))
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case rplOper:
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s.writeClient(fmt.Sprintf(":%s 381 %s :You are now an operator", s.name, s.upstreamLauncher.Self.Nick))
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case rplChannelModeIs:
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s.writeClient(fmt.Sprintf(":%s 324 %s %s %s %s", s.name, s.upstreamLauncher.Self.Nick, args[0], args[1], args[2]))
|
|
case rplKick:
|
|
s.writeClient(fmt.Sprintf(":%s KICK %s %s %s", args[0], args[1], args[2], args[3]))
|
|
case rplInfo:
|
|
s.writeClient(fmt.Sprintf(":%s 371 %s :%s", s.name, s.upstreamLauncher.Self.Nick, args[0]))
|
|
case rplVersion:
|
|
s.writeClient(fmt.Sprintf(":%s 351 %s %s", s.name, s.upstreamLauncher.Self.Nick, args[0]))
|
|
case rplMOTDStart:
|
|
s.writeClient(fmt.Sprintf(":%s 375 %s :- Message of the day - ", s.name, s.upstreamLauncher.Self.Nick))
|
|
case rplMOTD:
|
|
s.writeClient(fmt.Sprintf(":%s 372 %s :- %s", s.name, s.upstreamLauncher.Self.Nick, args[0]))
|
|
case rplEndOfMOTD:
|
|
s.writeClient(fmt.Sprintf(":%s 376 %s :- End of MOTD", s.name, s.upstreamLauncher.Self.Nick))
|
|
case rplPong:
|
|
s.writeClient(fmt.Sprintf(":%s PONG %s %s", s.name, s.upstreamLauncher.Self.Nick, s.name))
|
|
case errMoreArgs:
|
|
s.writeClient(fmt.Sprintf(":%s 461 %s :Not enough params", s.name, s.upstreamLauncher.Self.Nick))
|
|
case errNoNick:
|
|
s.writeClient(fmt.Sprintf(":%s 431 %s :No nickname given", s.name, s.upstreamLauncher.Self.Nick))
|
|
case errInvalidNick:
|
|
s.writeClient(fmt.Sprintf(":%s 432 %s %s :Erronenous nickname", s.name, s.upstreamLauncher.Self.Nick, args[0]))
|
|
case errNickInUse:
|
|
s.writeClient(fmt.Sprintf(":%s 433 %s %s :Nick already in use", s.name, s.upstreamLauncher.Self.Nick, args[0]))
|
|
case errAlreadyReg:
|
|
s.writeClient(fmt.Sprintf(":%s 462 :You need a valid nick first", s.name))
|
|
case errNoSuchNick:
|
|
s.writeClient(fmt.Sprintf(":%s 401 %s %s :No such nick/channel", s.name, s.upstreamLauncher.Self.Nick, args[0]))
|
|
case errUnknownCommand:
|
|
s.writeClient(fmt.Sprintf(":%s 421 %s %s :Unknown command", s.name, s.upstreamLauncher.Self.Nick, args[0]))
|
|
case errNotReg:
|
|
s.writeClient(fmt.Sprintf(":%s 451 :- You have not registered", s.name))
|
|
case errPassword:
|
|
s.writeClient(fmt.Sprintf(":%s 464 %s :Error, password incorrect", s.name, s.upstreamLauncher.Self.Nick))
|
|
case errNoPriv:
|
|
s.writeClient(fmt.Sprintf(":%s 481 %s :Permission denied", s.name, s.upstreamLauncher.Self.Nick))
|
|
case errCannotSend:
|
|
s.writeClient(fmt.Sprintf(":%s 404 %s %s :Cannot send to channel", s.name, s.upstreamLauncher.Self.Nick, args[0]))
|
|
}
|
|
}
|
|
|
|
func (s *Server) writeClient(output string) {
|
|
if s.clientConn == nil {
|
|
return
|
|
}
|
|
|
|
s.verbosef(" <<< %s", output)
|
|
|
|
s.clientConn.SetWriteDeadline(time.Now().Add(time.Second * 30))
|
|
if _, err := fmt.Fprintf(s.clientConn, "%s\r\n", output); err != nil {
|
|
s.DisconnectClient()
|
|
return
|
|
}
|
|
}
|