/* CLIENT */
func (n *Node) Dial(peerPubKey *rsa.PublicKey) (conn Conn, err error) {
infoHash, err := pubKeyToInfoHash(peerPubKey)
if err != nil {
return
}
peerNotifications := make(chan string, peerChanBufferCapacity)
n.dht.subscribeToInfoHash(dht.InfoHash(infoHash), peerNotifications)
// ask for the infohash
n.dht.PeersRequest(infoHash, false)
connSuccessChan := make(chan interface{})
for peerNotification := range peerNotifications {
go func(peerNotification string) {
// ASSUMPTION: peerNotifications doesn't yield duplicates.
someConn, connErr := n.handlePotentialPeer(peerNotification, peerPubKey)
if err != nil {
Log(LOG_INFO, "Failed to connect to potential peer %s: %s", peerNotification, connErr)
}
connSuccessChan <- someConn
}(peerNotification)
}
maybeConn, err := netutils.ReadWithTimeout(connSuccessChan, 30000)
if err != nil {
return
}
return maybeConn.(Conn), nil
}
// infohash used for this wherez lookup. This should be somewhat hard to guess
// but it's not exactly a secret.
func infoHash(passphrase []byte) (dht.InfoHash, error) {
// SHA256 of the passphrase.
h256 := sha256.New()
h256.Write(passphrase)
h := h256.Sum(nil)
// Assuming perfect rainbow databases, it's better if the infohash does not
// give out too much about the passphrase. Take half of this hash, then
// generate a SHA1 hash from it.
h2 := h[0 : sha256.Size/2]
// Mainline DHT uses sha1.
h160 := sha1.New()
h160.Write(h2)
h3 := h160.Sum(nil)
return dht.InfoHash(h3[:]), nil
}
func TestReceivePeers(t *testing.T) {
cleanupPeers()
d := NewDHT(NewDHTConfig())
peers := NewPeers(NewPeersConfig())
peers.Init()
m := make(map[dht.InfoHash][]string)
ps := make([]string, 0)
ps = append(ps, string([]byte{013, 026, 041, 054, 013, 013}))
ps = append(ps, string([]byte{013, 026, 041, 055, 013, 013}))
m[dht.InfoHash("")] = ps
d.ReceivePeers(m, peers.Peers)
assert.Equal(t, len(peers.Peers.Peerlist), 2)
assert.NotNil(t, peers.Peers.Peerlist["11.22.33.45:2827"])
assert.NotNil(t, peers.Peers.Peerlist["11.22.33.44:2827"])
wait()
d.Shutdown()
wait()
}
func trackerHandler(w http.ResponseWriter, r *http.Request) {
if r.FormValue("compact") != "1" {
http.Error(w, "Only compact protocol supported.", 400)
return
}
info_hash := dht.InfoHash(r.FormValue("info_hash"))
if len(info_hash) != 20 {
http.Error(w, "Bad info_hash.", 400)
return
}
response := TrackerResponse{
Interval: 300,
MinInterval: 60,
}
peers, ok := peerCache.Get(info_hash)
dhtNode.Find(info_hash)
if !ok || len(peers) == 0 {
response.Interval = 30
response.MinInterval = 10
time.Sleep(5 * time.Second)
peers, ok = peerCache.Get(info_hash)
}
if ok && len(peers) > 0 {
response.Incomplete = len(peers)
response.Peers = strings.Join(peers, "")
}
w.Header().Set("Content-Type", "application/octet-stream")
if err := bencode.Marshal(w, response); err != nil {
http.Error(w, err.Error(), 500)
}
}
