func (cs *ControlSession) DoHandshake(msg []byte, p *peerState) (err error) {
var h ExtensionHandshake
err = bencode.NewDecoder(bytes.NewReader(msg[1:])).Decode(&h)
if err != nil {
cs.log("Error when unmarshaling extension handshake")
return err
}
p.theirExtensions = make(map[string]int)
for name, code := range h.M {
p.theirExtensions[name] = code
}
// Now that handshake is done and we know their extension, send the
// current ih message, if we have one
//
// We need to de-serialize the current ih message saved in db before
// passing it to the sender otherwise it is serialized into a string
var currentIHMessage IHMessage
currentFromSession := cs.session.GetCurrentIHMessage()
if len(currentFromSession) > 0 {
err = bencode.NewDecoder(strings.NewReader(currentFromSession)).Decode(¤tIHMessage)
if err != nil {
cs.log("Error deserializing current ih message to be resent", err)
} else {
p.sendExtensionMessage("bs_metadata", currentIHMessage)
}
}
return nil
}
func NewControlSession(shareid id.Id, listenPort int, session *sharesession.Session, trackers []string) (*ControlSession, error) {
sid := "-tt" + strconv.Itoa(os.Getpid()) + "_" + strconv.FormatInt(rand.Int63(), 10)
// TODO: UPnP UDP port mapping.
cfg := dht.NewConfig()
cfg.Port = listenPort
cfg.NumTargetPeers = TARGET_NUM_PEERS
dhtNode, err := dht.New(cfg)
if err != nil {
log.Fatal("DHT node creation error", err)
}
current := session.GetCurrentIHMessage()
var currentIhMessage IHMessage
err = bencode.NewDecoder(strings.NewReader(current)).Decode(¤tIhMessage)
if err != nil {
log.Printf("Couldn't decode current message, starting from scratch: %s\n", err)
}
rev := "0-"
if currentIhMessage.Info.Rev != "" {
parts := strings.Split(currentIhMessage.Info.Rev, "-")
if len(parts) == 2 {
if _, err := strconv.Atoi(parts[0]); err == nil {
rev = currentIhMessage.Info.Rev
}
}
}
cs := &ControlSession{
Port: listenPort,
PeerID: sid[:20],
ID: shareid,
Torrents: make(chan Announce),
NewPeers: make(chan string),
dht: dhtNode,
peerMessageChan: make(chan peerMessage),
quit: make(chan struct{}),
ourExtensions: map[int]string{
1: "ut_pex",
2: "bs_metadata",
},
peers: newPeers(),
currentIH: currentIhMessage.Info.InfoHash,
rev: rev,
trackers: trackers,
session: session,
}
go cs.dht.Run()
cs.dht.PeersRequest(string(cs.ID.Infohash), true)
go cs.Run()
return cs, nil
}
func (cs *ControlSession) DoMetadata(msg []byte, p *peerState) (err error) {
var message IHMessage
err = bencode.NewDecoder(bytes.NewReader(msg)).Decode(&message)
if err != nil {
cs.log("Couldn't decode metadata message: ", err)
return
}
if message.Port == 0 {
return
}
// take his IP addr, use the advertised port
ip := p.conn.RemoteAddr().(*net.TCPAddr).IP.String()
port := strconv.Itoa(int(message.Port))
peer := ip + ":" + port
if cs.isNewerThan(message.Info.Rev) {
return
}
var tmpInfoBuf bytes.Buffer
err = bencode.NewEncoder(&tmpInfoBuf).Encode(message.Info)
if err != nil {
cs.log("Couldn't encode ih message, returning now")
return err
}
rawInfo := tmpInfoBuf.Bytes()
pub := [ed.PublicKeySize]byte(cs.ID.Pub)
var sig [ed.SignatureSize]byte
copy(sig[0:ed.SignatureSize], message.Sig)
ok := ed.Verify(&pub, rawInfo, &sig)
if !ok {
return errors.New("Bad Signature")
}
var test IHMessage
err = bencode.NewDecoder(bytes.NewReader(msg)).Decode(&test)
cs.session.SaveIHMessage(msg)
cs.Torrents <- Announce{
infohash: message.Info.InfoHash,
peer: peer,
}
return
}
func (t *TorrentSession) reload(info []byte) error {
err := bencode.NewDecoder(bytes.NewReader(info)).Decode(&t.m.Info)
if err != nil {
log.Println("Error when reloading torrent: ", err)
return err
}
t.miChan <- t.m
return t.load()
}
func DecodeInfoDict(bencodedInfo []byte) (map[string]interface{}, error) {
decodedMap := make(map[string]interface{})
bencodedBuffer := bytes.NewBuffer(bencodedInfo)
dec := bencode.NewDecoder(bencodedBuffer)
if err := dec.Decode(&decodedMap); err != nil {
return nil, err
}
return decodedMap, nil
}
func getTrackerInfo(url string) (tr *TrackerResponse, err error) {
r, err := proxyHttpGet(url)
if err != nil {
return
}
defer r.Body.Close()
if r.StatusCode >= 400 {
data, _ := ioutil.ReadAll(r.Body)
reason := "Bad Request " + string(data)
log.Println(reason)
err = errors.New(reason)
return
}
var tr2 TrackerResponse
err = bencode.NewDecoder(r.Body).Decode(&tr2)
r.Body.Close()
if err != nil {
return
}
// Decode peers
if len(tr2.PeersRaw) > 0 {
const peerLen = 6
nPeers := len(tr2.PeersRaw) / peerLen
// log.Println("Tracker gave us", nPeers, "peers")
tr2.Peers = make([]string, nPeers)
for i := 0; i < nPeers; i++ {
peer := nettools.BinaryToDottedPort(tr2.PeersRaw[i*peerLen : (i+1)*peerLen])
tr2.Peers[i/peerLen] = peer
}
}
// Decode peers6
if len(tr2.Peers6Raw) > 0 {
const peerLen = 18
nPeers := len(tr2.Peers6Raw) / peerLen
// log.Println("Tracker gave us", nPeers, "IPv6 peers")
tr2.Peers6 = make([]string, nPeers)
for i := 0; i < nPeers; i++ {
peerEntry := tr2.Peers6Raw[i*peerLen : (i+1)*peerLen]
host := net.IP(peerEntry[0:16])
port := int((uint(peerEntry[16]) << 8) | uint(peerEntry[17]))
peer := net.JoinHostPort(host.String(), strconv.Itoa(port))
tr2.Peers6[i] = peer
}
}
tr = &tr2
return
}
func (t *TorrentSession) DoExtension(msg []byte, p *peerState) (err error) {
var h ExtensionHandshake
if msg[0] == EXTENSION_HANDSHAKE {
err = bencode.NewDecoder(bytes.NewReader(msg[1:])).Decode(&h)
if err != nil {
log.Println("Error when unmarshaling extension handshake")
return err
}
p.theirExtensions = make(map[string]int)
for name, code := range h.M {
p.theirExtensions[name] = code
}
if t.si.HaveTorrent || t.si.ME != nil && t.si.ME.Transferring {
return
}
// Fill metadata info
if h.MetadataSize == 0 {
log.Printf("Missing metadata_size argument, this is invalid.")
return
}
nPieces := h.MetadataSize/METADATA_PIECE_SIZE + 1
t.si.ME.Pieces = make([][]byte, nPieces)
if _, ok := p.theirExtensions["ut_metadata"]; ok {
t.si.ME.Transferring = true
p.sendMetadataRequest(0)
}
} else if ext, ok := t.si.OurExtensions[int(msg[0])]; ok {
switch ext {
case "ut_metadata":
t.DoMetadata(msg[1:], p)
case "ut_pex":
t.DoPex(msg[1:], p)
default:
log.Println("Unknown extension: ", ext)
}
} else {
log.Println("Unknown extension: ", int(msg[0]))
}
return nil
}
// Processes received packets
func (node *Node) processPacket(data []byte, read int, addr net.Addr) error {
data_bigEndian, err := decodeIntoBigEndian(bytes.NewBuffer(data))
if err != nil {
return err
}
// Unmarshal BigEndian BEncode into struct
bencodeDecoder := bencode.NewDecoder(bytes.NewBuffer(data_bigEndian))
var message Message
if err := bencodeDecoder.Decode(&message); err != nil {
return err
}
// Further processing
return node.processMessage(&message, addr)
}
// Reads a torrent-file from the filesystem.
// TODO: Model will create torrent-file; obsoleting this.
func ReadFile(file multipart.File) *Torrent {
fmt.Printf("reading file...")
torrent := &Torrent{Info: &TorrentFile{}, peers: NewPeerMap()}
decoder := bencode.NewDecoder(file)
err := decoder.Decode(torrent.Info)
if err != nil {
fmt.Printf("error decoding torrent file: %s", err.Error())
}
metainfo := torrent.Info
torrent.Info.Info["private"] = 1
fmt.Printf("info[] hash: %x \n", metainfo.EncodeInfo())
fmt.Printf("# of pieces (hashes): %d \n", len(metainfo.Info["pieces"].(string))/20)
return torrent
}
// Wraps the command and arguments in a map[string]interface{}, then
// uses the given Conn to encode them directly to the wire. It sends
// authorization if it is supplied in the given CJDNS.
func (cjdns *CJDNS) Send(command string, args map[string]interface{}) (response map[string]interface{}) {
// Exit if the command is not given.
if command == "" {
return
}
// Otherwise, create the map which will be used to encode the
// message.
message := make(map[string]interface{})
if cjdns.cookie != "" && cjdns.password != "" {
// If there is authentication involved, then use
// "aq". Otherwise, "q".
hash := sha256.New()
hash.Write([]byte(cjdns.password + cjdns.cookie))
message["aq"] = command
message["args"] = args
message["cookie"] = cjdns.cookie
message["hash"] = hex.EncodeToString(hash.Sum(nil)) // as specified
message["q"] = CommandAuth
// Prepare the hash
m, err := bencode.EncodeString(message)
if err != nil {
return
}
hash = sha256.New()
hash.Write([]byte(m))
message["hash"] = hex.EncodeToString(hash.Sum(nil))
} else {
message["q"] = command
}
m, err := bencode.EncodeString(message)
if err == nil {
io.WriteString(cjdns.Conn, m)
bencode.NewDecoder(cjdns.Conn).Decode(&response)
}
return
}
// Tries to call 'procedure' on remote node, with supplied 'args' and allocated return values 'reply'.
// 'timeout' can be used to specify a maximum time to wait for a reply (in seconds). If timeout is 0, we wait forever.
// The reliability of this completing successfully is dependent on the network protocol (UDP is unreliable)
// Returns an error if there is a timeout
func (node *Node) Call(procedure string, addr net.Addr, args interface{}, reply interface{}, timeout int) (err error) {
// Get our call, which contains the message ID
call := node.nextCall(addr)
// Create Query
query := Query{ProcedureName: procedure, MessageID: call.MessageID}
query.constructArgs(args)
// Create Message
message := Message{Query: &query}
// Encode it into BEncode
buf := new(bytes.Buffer)
bencodeE := bencode.NewEncoder(buf)
if err := bencodeE.Encode(message); err != nil {
fmt.Errorf("qrp:", "Error encoding query message into BEncode: %s\n", err.Error())
return err
}
buf_bigEndian, err := encodeIntoBigEndian(buf)
if err != nil {
fmt.Errorf("qrp:", "Error encoding query message into BigEndian: %s\n", err.Error())
return err
}
// Create channel for receiving response
responseChan := make(responseChannel)
// Allocate channel
node.pendingMutex.Lock()
node.pending[call] = &responseChan
node.pendingMutex.Unlock()
// Delete channel after exit
defer func() {
node.pendingMutex.Lock()
delete(node.pending, call)
node.pendingMutex.Unlock()
}()
// Send to host
node.sendingMutex.Lock()
node.connection.WriteTo(buf_bigEndian, addr)
node.sendingMutex.Unlock()
// If timeout isn't 0, initate the timeout function concurrently
timeoutChan := make(chan bool, 1)
if timeout > 0 {
go func() {
// Timeout function
time.Sleep(time.Duration(timeout) * time.Second)
timeoutChan <- true
}()
}
// Wait for response on channel
select {
case replydata := <-responseChan:
// We received a reply
// Decode args
argsReader := bytes.NewReader(replydata)
argsDecoder := bencode.NewDecoder(argsReader)
err := argsDecoder.Decode(reply)
if err != nil {
fmt.Errorf("qrp:", "Error decoding reply return data into value: %s\n", err.Error())
return err
}
case <-timeoutChan:
// We timed out
return new(TimeoutError)
}
return nil
}
// Processes received queries
func (node *Node) processQuery(query *Query, addr net.Addr) error {
procedureName := query.ProcedureName
if procedure := node.procedures[procedureName]; procedure != nil {
// Procedure exists (it's being served)
method := procedure.Method
function := method.Func
// Initialize value
argValue, replyValue := reflect.New(procedure.ArgType.Elem()), reflect.New(procedure.ReplyType.Elem())
// Set value of arg
argsReader := bytes.NewReader(query.ProcedureData)
argsDecoder := bencode.NewDecoder(argsReader)
err := argsDecoder.Decode(argValue.Interface())
if err != nil {
fmt.Errorf("qrp:", "Error decoding procedure data into value: %s\n", err.Error())
return err
}
// Invoke the function
function.Call([]reflect.Value{procedure.Receiver, argValue, replyValue})
// Create reply
reply := Reply{MessageID: query.MessageID}
argsBuf := new(bytes.Buffer)
argsEncoder := bencode.NewEncoder(argsBuf)
argsEncoder.Encode(replyValue.Interface())
reply.ReturnData, err = encodeIntoBigEndian(argsBuf)
if err != nil {
fmt.Errorf("qrp:", "Error encoding reply return data: %s\n", err.Error())
return err
}
// Create message
message := Message{Reply: &reply}
// Encode message
messageBuf := new(bytes.Buffer)
messageEncoder := bencode.NewEncoder(messageBuf)
err = messageEncoder.Encode(message)
if err != nil {
fmt.Errorf("qrp:", "Error encoding reply message into BEncode: %s\n", err.Error())
return err
}
message_bigEndian, err := encodeIntoBigEndian(messageBuf)
if err != nil {
fmt.Errorf("qrp:", "Error encoding reply message into BigEndian: %s\n", err.Error())
return err
}
// Send to host
node.sendingMutex.Lock()
node.connection.WriteTo(message_bigEndian, addr)
node.sendingMutex.Unlock()
return nil
} else {
return &BadProcedureError{procedureName}
}
return nil
}
func (t *Torrent) Resolve() error {
if t.IsMagnet() {
t.hasResolved = true
return nil
}
var torrentFile struct {
Announce string `bencode:"announce"`
AnnounceList [][]string `bencode:"announce-list"`
Info map[string]interface{} `bencode:"info"`
}
// We don't need trackers for public torrents since we'll find them on the
// DHT or public trackers
if (t.InfoHash != "" && t.Name != "" && t.Peers > 0 && t.Seeds > 0) && (t.IsPrivate == false || len(t.Trackers) > 0) {
return nil
}
parts := strings.Split(t.URI, "|")
uri := parts[0]
req, err := http.NewRequest("GET", uri, nil)
if err != nil {
return err
}
if len(parts) > 1 {
for _, part := range parts[1:] {
keyVal := strings.SplitN(part, "=", 2)
req.Header.Add(keyVal[0], keyVal[1])
}
}
resp, err := httpClient.Do(req)
if err != nil {
return err
}
dec := bencode.NewDecoder(resp.Body)
// FIXME!!!!
if err := dec.Decode(&torrentFile); err != nil {
return err
}
if t.InfoHash == "" {
hasher := sha1.New()
bencode.NewEncoder(hasher).Encode(torrentFile.Info)
t.InfoHash = hex.EncodeToString(hasher.Sum(nil))
}
if t.Name == "" {
t.Name = torrentFile.Info["name"].(string)
}
if len(t.Trackers) == 0 {
t.Trackers = append(t.Trackers, torrentFile.Announce)
for _, trackers := range torrentFile.AnnounceList {
t.Trackers = append(t.Trackers, trackers...)
}
}
t.hasResolved = true
t.initialize()
return nil
}