package jounce import ( "fmt" "io" "net" "strings" "gopkg.in/irc.v3" ) type ircError struct { Message *irc.Message } func newUnknownCommandError(cmd string) ircError { return ircError{&irc.Message{ Command: irc.ERR_UNKNOWNCOMMAND, Params: []string{ "*", cmd, "Unknown command", }, }} } func newNeedMoreParamsError(cmd string) ircError { return ircError{&irc.Message{ Command: irc.ERR_NEEDMOREPARAMS, Params: []string{ "*", cmd, "Not enough parameters", }, }} } func (err ircError) Error() string { return err.Message.String() } type downstreamConn struct { net net.Conn irc *irc.Conn srv *Server logger Logger messages chan<- *irc.Message registered bool user *user closed bool nick string username string realname string } func newDownstreamConn(srv *Server, netConn net.Conn) *downstreamConn { msgs := make(chan *irc.Message, 64) conn := &downstreamConn{ net: netConn, irc: irc.NewConn(netConn), srv: srv, logger: &prefixLogger{srv.Logger, fmt.Sprintf("downstream %q: ", netConn.RemoteAddr())}, messages: msgs, } go func() { for msg := range msgs { if err := conn.irc.WriteMessage(msg); err != nil { conn.logger.Printf("failed to write message: %v", err) } } if err := conn.net.Close(); err != nil { conn.logger.Printf("failed to close connection: %v", err) } else { conn.logger.Printf("connection closed") } }() return conn } func (c *downstreamConn) prefix() *irc.Prefix { return &irc.Prefix{ Name: c.nick, User: c.username, // TODO: fill the host? } } func (c *downstreamConn) readMessages() error { c.logger.Printf("new connection") for { msg, err := c.irc.ReadMessage() if err == io.EOF { break } else if err != nil { return fmt.Errorf("failed to read IRC command: %v", err) } err = c.handleMessage(msg) if ircErr, ok := err.(ircError); ok { ircErr.Message.Prefix = c.srv.prefix() c.messages <- ircErr.Message } else if err != nil { return fmt.Errorf("failed to handle IRC command %q: %v", msg.Command, err) } if c.closed { return nil } } return nil } func (c *downstreamConn) Close() error { if c.closed { return fmt.Errorf("downstream connection already closed") } if u := c.user; u != nil { u.lock.Lock() for i := range u.downstreamConns { if u.downstreamConns[i] == c { u.downstreamConns = append(u.downstreamConns[:i], u.downstreamConns[i+1:]...) } } u.lock.Unlock() } close(c.messages) c.closed = true return nil } func (c *downstreamConn) handleMessage(msg *irc.Message) error { switch msg.Command { case "QUIT": return c.Close() case "PING": // TODO: handle params c.messages <- &irc.Message{ Prefix: c.srv.prefix(), Command: "PONG", Params: []string{c.srv.Hostname}, } return nil default: if c.registered { return c.handleMessageRegistered(msg) } else { return c.handleMessageUnregistered(msg) } } } func (c *downstreamConn) handleMessageUnregistered(msg *irc.Message) error { switch msg.Command { case "NICK": if err := parseMessageParams(msg, &c.nick); err != nil { return err } case "USER": var username string if err := parseMessageParams(msg, &username, nil, nil, &c.realname); err != nil { return err } c.username = "~" + username default: c.logger.Printf("unhandled message: %v", msg) return newUnknownCommandError(msg.Command) } if c.username != "" && c.nick != "" { return c.register() } return nil } func (c *downstreamConn) register() error { u := c.srv.getUser(strings.TrimPrefix(c.username, "~")) if u == nil { c.logger.Printf("failed authentication: unknown username %q", c.username) c.messages <- &irc.Message{ Prefix: c.srv.prefix(), Command: irc.ERR_PASSWDMISMATCH, Params: []string{"*", "Invalid username or password"}, } return nil } c.registered = true c.user = u u.lock.Lock() u.downstreamConns = append(u.downstreamConns, c) u.lock.Unlock() c.messages <- &irc.Message{ Prefix: c.srv.prefix(), Command: irc.RPL_WELCOME, Params: []string{c.nick, "Welcome to jounce, " + c.nick}, } c.messages <- &irc.Message{ Prefix: c.srv.prefix(), Command: irc.RPL_YOURHOST, Params: []string{c.nick, "Your host is " + c.srv.Hostname}, } c.messages <- &irc.Message{ Prefix: c.srv.prefix(), Command: irc.RPL_CREATED, Params: []string{c.nick, "Who cares when the server was created?"}, } c.messages <- &irc.Message{ Prefix: c.srv.prefix(), Command: irc.RPL_MYINFO, Params: []string{c.nick, c.srv.Hostname, "jounce", "aiwroO", "OovaimnqpsrtklbeI"}, } c.messages <- &irc.Message{ Prefix: c.srv.prefix(), Command: irc.ERR_NOMOTD, Params: []string{c.nick, "No MOTD"}, } u.forEachUpstream(func(uc *upstreamConn) { // TODO: fix races accessing upstream connection data for _, ch := range uc.channels { if ch.complete { forwardChannel(c, ch) } } }) return nil } func (c *downstreamConn) handleMessageRegistered(msg *irc.Message) error { switch msg.Command { case "USER": return ircError{&irc.Message{ Command: irc.ERR_ALREADYREGISTERED, Params: []string{c.nick, "You may not reregister"}, }} case "NICK": c.user.forEachUpstream(func(uc *upstreamConn) { uc.messages <- msg }) case "JOIN": var name string if err := parseMessageParams(msg, &name); err != nil { return err } if ch, _ := c.user.getChannel(name); ch != nil { break // already joined } // TODO: extract network name from channel name return ircError{&irc.Message{ Command: irc.ERR_NOSUCHCHANNEL, Params: []string{name, "Channel name ambiguous"}, }} case "PART": var name string if err := parseMessageParams(msg, &name); err != nil { return err } ch, err := c.user.getChannel(name) if err != nil { return err } ch.conn.messages <- msg // TODO: remove channel from upstream config case "MODE": var name string if err := parseMessageParams(msg, &name); err != nil { return err } var modeStr string if len(msg.Params) > 1 { modeStr = msg.Params[1] } if msg.Prefix.Name != name { ch, err := c.user.getChannel(name) if err != nil { return err } if modeStr != "" { ch.conn.messages <- msg } else { c.messages <- &irc.Message{ Prefix: c.srv.prefix(), Command: irc.RPL_CHANNELMODEIS, Params: []string{ch.Name, string(ch.modes)}, } } } else { if name != c.nick { return ircError{&irc.Message{ Command: irc.ERR_USERSDONTMATCH, Params: []string{c.nick, "Cannot change mode for other users"}, }} } if modeStr != "" { c.user.forEachUpstream(func(uc *upstreamConn) { uc.messages <- msg }) } else { c.messages <- &irc.Message{ Prefix: c.srv.prefix(), Command: irc.RPL_UMODEIS, Params: []string{""}, // TODO } } } default: c.logger.Printf("unhandled message: %v", msg) return newUnknownCommandError(msg.Command) } return nil }