grumble/message.go

// Grumble - an implementation of Murmur in Go
// Copyright (c) 2010 The Grumble Authors
// The use of this source code is goverened by a BSD-style
// license that can be found in the LICENSE-file.

package main

import (
	"log"
	"mumbleproto"
	"goprotobuf.googlecode.com/hg/proto"
	"net"
	"cryptstate"
)

// These are the different kinds of messages
// that are defined for the Mumble protocol
const (
	MessageVersion = iota
	MessageUDPTunnel
	MessageAuthenticate
	MessagePing
	MessageReject
	MessageServerSync
	MessageChannelRemove
	MessageChannelState
	MessageUserRemove
	MessageUserState
	MessageBanList
	MessageTextMessage
	MessagePermissionDenied
	MessageACL
	MessageQueryUsers
	MessageCryptSetup
	MessageContextActionAdd
	MessageContextAction
	MessageUserList
	MessageVoiceTarget
	MessagePermissionQuery
	MessageCodecVersion
	MessageUserStats
	MessageRequestBlob
	MessageServerConfig
)

const (
	UDPMessageVoiceCELTAlpha = iota
	UDPMessagePing
	UDPMessageVoiceSpeex
	UDPMessageVoiceCELTBeta
)

type Message struct {
	buf  []byte

	// Kind denotes a message kind for TCP packets. This field
	// is ignored for UDP packets.
	kind uint16

	// For UDP datagrams one of these fiels have to be filled out.
	// If there is no connection established, address must be used.
	// If the datagram comes from an already-connected client, the
	// client field should point to that client.
	client *ClientConnection
	address net.Addr
}

func (server *Server) handleCryptSetup(client *ClientConnection, msg *Message) {
	cs := &mumbleproto.CryptSetup{}
	err := proto.Unmarshal(msg.buf, cs)
	if err != nil {
		client.Panic(err.String())
		return
	}

	// No client nonce. This means the client
	// is requesting that we re-sync our nonces.
	if len(cs.ClientNonce) == 0 {
		log.Printf("Requested crypt-nonce resync")
		cs.ClientNonce = make([]byte, cryptstate.AESBlockSize)
		if copy(cs.ClientNonce, client.crypt.EncryptIV[0:]) != cryptstate.AESBlockSize {
			return
		}
		client.sendProtoMessage(MessageCryptSetup, cs)
	} else {
		log.Printf("Received client nonce")
		if len(cs.ClientNonce) != cryptstate.AESBlockSize {
			return
		}

		client.crypt.Resync += 1
		if copy(client.crypt.DecryptIV[0:], cs.ClientNonce) != cryptstate.AESBlockSize {
			return
		}
		log.Printf("Crypt re-sync successful")
	}
}

func (server *Server) handlePingMessage(client *ClientConnection, msg *Message) {
	ping := &mumbleproto.Ping{}
	err := proto.Unmarshal(msg.buf, ping)
	if err != nil {
		client.Panic(err.String())
		return
	}

	// Phony response for ping messages. We don't keep stats
	// for this yet.
	client.sendProtoMessage(MessagePing, &mumbleproto.Ping{
		Timestamp: ping.Timestamp,
		Good:      proto.Uint32(uint32(client.crypt.Good)),
		Late:      proto.Uint32(uint32(client.crypt.Late)),
		Lost:      proto.Uint32(uint32(client.crypt.Lost)),
		Resync:    proto.Uint32(uint32(client.crypt.Resync)),
	})
}

func (server *Server) handleChannelAddMessage(client *ClientConnection, msg *Message) {
}

func (server *Server) handleChannelRemoveMessage(client *ClientConnection, msg *Message) {
}

func (server *Server) handleChannelStateMessage(client *ClientConnection, msg *Message) {
}

func (server *Server) handleUserRemoveMessage(client *ClientConnection, msg *Message) {
}

func (server *Server) handleUserStateMessage(client *ClientConnection, msg *Message) {
}

func (server *Server) handleBanListMessage(client *ClientConnection, msg *Message) {
}

func (server *Server) handleTextMessage(client *ClientConnection, msg *Message) {
	txtmsg := &mumbleproto.TextMessage{}
	err := proto.Unmarshal(msg.buf, txtmsg)
	if err != nil {
		client.Panic(err.String())
		return
	}

	users := []*ClientConnection{};
	for i := 0; i < len(txtmsg.Session); i++ {
		user := server.getClientConnection(txtmsg.Session[i])
		users = append(users, user)
	}

	for _, user := range users {
		user.sendProtoMessage(MessageTextMessage, &mumbleproto.TextMessage{
			Actor:   proto.Uint32(client.Session),
			Message: txtmsg.Message,
		})
	}
}

func (server *Server) handleAclMessage(client *ClientConnection, msg *Message) {
}

// User query
func (server *Server) handleQueryUsers(client *ClientConnection, msg *Message) {
}

// User stats message. Shown in the Mumble client when a
// user right clicks a user and selects 'User Information'.
func (server *Server) handleUserStatsMessage(client *ClientConnection, msg *Message) {
	stats := &mumbleproto.UserStats{}
	err := proto.Unmarshal(msg.buf, stats)
	if err != nil {
		client.Panic(err.String())
	}
}