14 log "github.com/sirupsen/logrus"
15 "github.com/tendermint/go-wire"
17 "github.com/vapor/common"
18 cfg "github.com/vapor/config"
19 "github.com/vapor/crypto"
20 "github.com/vapor/crypto/ed25519"
21 "github.com/vapor/p2p/netutil"
22 "github.com/vapor/version"
27 logModule = "discover"
32 errPacketTooSmall = errors.New("too small")
33 errBadPrefix = errors.New("bad prefix")
34 errExpired = errors.New("expired")
35 errUnsolicitedReply = errors.New("unsolicited reply")
36 errUnknownNode = errors.New("unknown node")
37 errTimeout = errors.New("RPC timeout")
38 errClockWarp = errors.New("reply deadline too far in the future")
39 errClosed = errors.New("socket closed")
44 respTimeout = 1 * time.Second
45 queryDelay = 1000 * time.Millisecond
46 expiration = 20 * time.Second
48 ntpFailureThreshold = 32 // Continuous timeouts after which to check NTP
49 ntpWarningCooldown = 10 * time.Minute // Minimum amount of time to pass before repeating NTP warning
50 driftThreshold = 10 * time.Second // Allowed clock drift before warning user
53 // ReadPacket is sent to the unhandled channel when it could not be processed
54 type ReadPacket struct {
59 // Config holds Table-related settings.
61 // These settings are required and configure the UDP listener:
62 PrivateKey *ecdsa.PrivateKey
64 // These settings are optional:
65 AnnounceAddr *net.UDPAddr // local address announced in the DHT
66 NodeDBPath string // if set, the node database is stored at this filesystem location
67 //NetRestrict *netutil.Netlist // network whitelist
68 Bootnodes []*Node // list of bootstrap nodes
69 Unhandled chan<- ReadPacket // unhandled packets are sent on this channel
72 // RPC request structures
82 // Ignore additional fields (for forward compatibility).
86 // pong is the reply to ping.
88 // This field should mirror the UDP envelope address
89 // of the ping packet, which provides a way to discover the
90 // the external address (after NAT).
93 ReplyTok []byte // This contains the hash of the ping packet.
94 Expiration uint64 // Absolute timestamp at which the packet becomes invalid.
101 // Ignore additional fields (for forward compatibility).
105 // findnode is a query for nodes close to the given target.
107 Target NodeID // doesn't need to be an actual public key
109 // Ignore additional fields (for forward compatibility).
113 // findnode is a query for nodes close to the given target.
114 findnodeHash struct {
117 // Ignore additional fields (for forward compatibility).
125 // Ignore additional fields (for forward compatibility).
129 topicRegister struct {
140 // reply to topicQuery
147 IP net.IP // len 4 for IPv4 or 16 for IPv6
148 UDP uint16 // for discovery protocol
149 TCP uint16 // for RLPx protocol
154 IP net.IP // len 4 for IPv4 or 16 for IPv6
155 UDP uint16 // for discovery protocol
156 TCP uint16 // for RLPx protocol
161 versionPrefix = []byte("bytom discovery")
162 versionPrefixSize = len(versionPrefix)
165 headSize = versionPrefixSize + nodeIDSize + sigSize // space of packet frame data
168 // Neighbors replies are sent across multiple packets to
169 // stay below the 1280 byte limit. We compute the maximum number
170 // of entries by stuffing a packet until it grows too large.
171 var maxNeighbors = func() int {
172 p := neighbors{Expiration: ^uint64(0)}
173 maxSizeNode := rpcNode{IP: make(net.IP, 16), UDP: ^uint16(0), TCP: ^uint16(0)}
175 p.Nodes = append(p.Nodes, maxSizeNode)
178 b := new(bytes.Buffer)
179 wire.WriteJSON(p, b, &size, &err)
181 // If this ever happens, it will be caught by the unit tests.
182 panic("cannot encode: " + err.Error())
184 if headSize+size+1 >= 1280 {
190 var maxTopicNodes = func() int {
192 maxSizeNode := rpcNode{IP: make(net.IP, 16), UDP: ^uint16(0), TCP: ^uint16(0)}
194 p.Nodes = append(p.Nodes, maxSizeNode)
197 b := new(bytes.Buffer)
198 wire.WriteJSON(p, b, &size, &err)
200 // If this ever happens, it will be caught by the unit tests.
201 panic("cannot encode: " + err.Error())
203 if headSize+size+1 >= 1280 {
209 func makeEndpoint(addr *net.UDPAddr, tcpPort uint16) rpcEndpoint {
214 return rpcEndpoint{IP: ip, UDP: uint16(addr.Port), TCP: tcpPort}
217 func (e1 rpcEndpoint) equal(e2 rpcEndpoint) bool {
218 return e1.UDP == e2.UDP && e1.TCP == e2.TCP && e1.IP.Equal(e2.IP)
221 func nodeFromRPC(sender *net.UDPAddr, rn rpcNode) (*Node, error) {
222 if err := netutil.CheckRelayIP(sender.IP, rn.IP); err != nil {
225 n := NewNode(rn.ID, rn.IP, rn.UDP, rn.TCP)
226 err := n.validateComplete()
230 func nodeToRPC(n *Node) rpcNode {
231 return rpcNode{ID: n.ID, IP: n.IP, UDP: n.UDP, TCP: n.TCP}
234 type ingressPacket struct {
236 remoteAddr *net.UDPAddr
239 data interface{} // one of the RPC structs
243 type conn interface {
244 ReadFromUDP(b []byte) (n int, addr *net.UDPAddr, err error)
245 WriteToUDP(b []byte, addr *net.UDPAddr) (n int, err error)
250 type netWork interface {
251 reqReadPacket(pkt ingressPacket)
255 // udp implements the RPC protocol.
258 priv ed25519.PrivateKey
259 ourEndpoint rpcEndpoint
264 func NewDiscover(config *cfg.Config, priv ed25519.PrivateKey, port uint16) (*Network, error) {
265 addr, err := net.ResolveUDPAddr("udp", net.JoinHostPort("0.0.0.0", strconv.FormatUint(uint64(port), 10)))
270 conn, err := net.ListenUDP("udp", addr)
275 realaddr := conn.LocalAddr().(*net.UDPAddr)
276 ntab, err := ListenUDP(priv, conn, realaddr, path.Join(config.DBDir(), "discover"), nil)
280 seeds, err := QueryDNSSeeds(net.LookupHost)
282 log.WithFields(log.Fields{"module": logModule, "err": err}).Error("fail on query dns seeds")
285 codedSeeds := netutil.CheckAndSplitAddresses(config.P2P.Seeds)
286 seeds = append(seeds, codedSeeds...)
292 for _, seed := range seeds {
293 version.Status.AddSeed(seed)
294 url := "enode://" + hex.EncodeToString(crypto.Sha256([]byte(seed))) + "@" + seed
295 nodes = append(nodes, MustParseNode(url))
298 if err = ntab.SetFallbackNodes(nodes); err != nil {
304 // ListenUDP returns a new table that listens for UDP packets on laddr.
305 func ListenUDP(priv ed25519.PrivateKey, conn conn, realaddr *net.UDPAddr, nodeDBPath string, netrestrict *netutil.Netlist) (*Network, error) {
306 transport, err := listenUDP(priv, conn, realaddr)
311 net, err := newNetwork(transport, priv.Public(), nodeDBPath, netrestrict)
315 log.WithFields(log.Fields{"module": logModule, "net": net.tab.self}).Info("UDP listener up v5")
317 go transport.readLoop()
321 func listenUDP(priv ed25519.PrivateKey, conn conn, realaddr *net.UDPAddr) (*udp, error) {
322 return &udp{conn: conn, priv: priv, ourEndpoint: makeEndpoint(realaddr, uint16(realaddr.Port))}, nil
325 func (t *udp) localAddr() *net.UDPAddr {
326 return t.conn.LocalAddr().(*net.UDPAddr)
329 func (t *udp) Close() {
333 func (t *udp) send(remote *Node, ptype nodeEvent, data interface{}) (hash []byte) {
334 hash, _ = t.sendPacket(remote.ID, remote.addr(), byte(ptype), data)
338 func (t *udp) sendPing(remote *Node, toaddr *net.UDPAddr, topics []Topic) (hash []byte) {
339 hash, _ = t.sendPacket(remote.ID, toaddr, byte(pingPacket), ping{
342 To: makeEndpoint(toaddr, uint16(toaddr.Port)), // TODO: maybe use known TCP port from DB
343 Expiration: uint64(time.Now().Add(expiration).Unix()),
349 func (t *udp) sendFindnode(remote *Node, target NodeID) {
350 t.sendPacket(remote.ID, remote.addr(), byte(findnodePacket), findnode{
352 Expiration: uint64(time.Now().Add(expiration).Unix()),
356 func (t *udp) sendNeighbours(remote *Node, results []*Node) {
357 // Send neighbors in chunks with at most maxNeighbors per packet
358 // to stay below the 1280 byte limit.
359 p := neighbors{Expiration: uint64(time.Now().Add(expiration).Unix())}
360 for i, result := range results {
361 p.Nodes = append(p.Nodes, nodeToRPC(result))
362 if len(p.Nodes) == maxNeighbors || i == len(results)-1 {
363 t.sendPacket(remote.ID, remote.addr(), byte(neighborsPacket), p)
364 p.Nodes = p.Nodes[:0]
369 func (t *udp) sendFindnodeHash(remote *Node, target common.Hash) {
370 t.sendPacket(remote.ID, remote.addr(), byte(findnodeHashPacket), findnodeHash{
371 Target: common.Hash(target),
372 Expiration: uint64(time.Now().Add(expiration).Unix()),
376 func (t *udp) sendTopicRegister(remote *Node, topics []Topic, idx int, pong []byte) {
377 t.sendPacket(remote.ID, remote.addr(), byte(topicRegisterPacket), topicRegister{
384 func (t *udp) sendTopicNodes(remote *Node, queryHash common.Hash, nodes []*Node) {
385 p := topicNodes{Echo: queryHash}
387 for _, result := range nodes {
388 if result.IP.Equal(t.net.selfIP()) || netutil.CheckRelayIP(remote.IP, result.IP) == nil {
389 p.Nodes = append(p.Nodes, nodeToRPC(result))
391 if len(p.Nodes) == maxTopicNodes {
392 t.sendPacket(remote.ID, remote.addr(), byte(topicNodesPacket), p)
393 p.Nodes = p.Nodes[:0]
397 if !sent || len(p.Nodes) > 0 {
398 t.sendPacket(remote.ID, remote.addr(), byte(topicNodesPacket), p)
402 func (t *udp) sendPacket(toid NodeID, toaddr *net.UDPAddr, ptype byte, req interface{}) (hash []byte, err error) {
403 packet, hash, err := encodePacket(t.priv, ptype, req)
407 log.WithFields(log.Fields{"module": logModule, "event": nodeEvent(ptype), "to id": hex.EncodeToString(toid[:8]), "to addr": toaddr}).Debug("send packet")
408 if _, err = t.conn.WriteToUDP(packet, toaddr); err != nil {
409 log.WithFields(log.Fields{"module": logModule, "error": err}).Info(fmt.Sprint("UDP send failed"))
414 // zeroed padding space for encodePacket.
415 var headSpace = make([]byte, headSize)
417 func encodePacket(priv ed25519.PrivateKey, ptype byte, req interface{}) (p, hash []byte, err error) {
418 b := new(bytes.Buffer)
422 wire.WriteJSON(req, b, &size, &err)
424 log.WithFields(log.Fields{"module": logModule, "error": err}).Error("error encoding packet")
428 nodeID := priv.Public()
429 sig := ed25519.Sign(priv, common.BytesToHash(packet[headSize:]).Bytes())
430 copy(packet, versionPrefix)
431 copy(packet[versionPrefixSize:], nodeID[:])
432 copy(packet[versionPrefixSize+nodeIDSize:], sig)
434 hash = common.BytesToHash(packet[versionPrefixSize:]).Bytes()
435 return packet, hash, nil
438 // readLoop runs in its own goroutine. it injects ingress UDP packets
439 // into the network loop.
440 func (t *udp) readLoop() {
442 // Discovery packets are defined to be no larger than 1280 bytes.
443 // Packets larger than this size will be cut at the end and treated
444 // as invalid because their hash won't match.
445 buf := make([]byte, 1280)
447 nbytes, from, err := t.conn.ReadFromUDP(buf)
448 if netutil.IsTemporaryError(err) {
449 // Ignore temporary read errors.
450 log.WithFields(log.Fields{"module": logModule, "error": err}).Debug("Temporary read error")
452 } else if err != nil {
453 // Shut down the loop for permament errors.
454 log.WithFields(log.Fields{"module": logModule, "error": err}).Debug("Read error")
457 t.handlePacket(from, buf[:nbytes])
461 func (t *udp) handlePacket(from *net.UDPAddr, buf []byte) error {
462 pkt := ingressPacket{remoteAddr: from}
463 if err := decodePacket(buf, &pkt); err != nil {
464 log.WithFields(log.Fields{"module": logModule, "from": from, "error": err}).Error("Bad packet")
467 t.net.reqReadPacket(pkt)
471 func decodePacket(buffer []byte, pkt *ingressPacket) error {
472 if len(buffer) < headSize+1 {
473 return errPacketTooSmall
475 buf := make([]byte, len(buffer))
477 prefix, fromID, sigdata := buf[:versionPrefixSize], buf[versionPrefixSize:versionPrefixSize+nodeIDSize], buf[headSize:]
478 if !bytes.Equal(prefix, versionPrefix) {
482 pkt.hash = common.BytesToHash(buf[versionPrefixSize:]).Bytes()
483 pkt.remoteID = ByteID(fromID)
484 switch pkt.ev = nodeEvent(sigdata[0]); pkt.ev {
490 pkt.data = new(findnode)
491 case neighborsPacket:
492 pkt.data = new(neighbors)
493 case findnodeHashPacket:
494 pkt.data = new(findnodeHash)
495 case topicRegisterPacket:
496 pkt.data = new(topicRegister)
497 case topicQueryPacket:
498 pkt.data = new(topicQuery)
499 case topicNodesPacket:
500 pkt.data = new(topicNodes)
502 return fmt.Errorf("unknown packet type: %d", sigdata[0])
505 wire.ReadJSON(pkt.data, sigdata[1:], &err)
507 log.WithFields(log.Fields{"module": logModule, "error": err}).Error("wire readjson err")