diff options
Diffstat (limited to 'vendor/github.com/hashicorp/memberlist/net.go')
| -rw-r--r-- | vendor/github.com/hashicorp/memberlist/net.go | 1069 |
1 files changed, 1069 insertions, 0 deletions
diff --git a/vendor/github.com/hashicorp/memberlist/net.go b/vendor/github.com/hashicorp/memberlist/net.go new file mode 100644 index 000000000..e0036d01d --- /dev/null +++ b/vendor/github.com/hashicorp/memberlist/net.go @@ -0,0 +1,1069 @@ +package memberlist + +import ( + "bufio" + "bytes" + "encoding/binary" + "fmt" + "hash/crc32" + "io" + "net" + "time" + + "github.com/armon/go-metrics" + "github.com/hashicorp/go-msgpack/codec" +) + +// This is the minimum and maximum protocol version that we can +// _understand_. We're allowed to speak at any version within this +// range. This range is inclusive. +const ( + ProtocolVersionMin uint8 = 1 + + // Version 3 added support for TCP pings but we kept the default + // protocol version at 2 to ease transition to this new feature. + // A memberlist speaking version 2 of the protocol will attempt + // to TCP ping another memberlist who understands version 3 or + // greater. + // + // Version 4 added support for nacks as part of indirect probes. + // A memberlist speaking version 2 of the protocol will expect + // nacks from another memberlist who understands version 4 or + // greater, and likewise nacks will be sent to memberlists who + // understand version 4 or greater. + ProtocolVersion2Compatible = 2 + + ProtocolVersionMax = 5 +) + +// messageType is an integer ID of a type of message that can be received +// on network channels from other members. +type messageType uint8 + +// The list of available message types. +const ( + pingMsg messageType = iota + indirectPingMsg + ackRespMsg + suspectMsg + aliveMsg + deadMsg + pushPullMsg + compoundMsg + userMsg // User mesg, not handled by us + compressMsg + encryptMsg + nackRespMsg + hasCrcMsg +) + +// compressionType is used to specify the compression algorithm +type compressionType uint8 + +const ( + lzwAlgo compressionType = iota +) + +const ( + MetaMaxSize = 512 // Maximum size for node meta data + compoundHeaderOverhead = 2 // Assumed header overhead + compoundOverhead = 2 // Assumed overhead per entry in compoundHeader + userMsgOverhead = 1 + blockingWarning = 10 * time.Millisecond // Warn if a UDP packet takes this long to process + maxPushStateBytes = 10 * 1024 * 1024 +) + +// ping request sent directly to node +type ping struct { + SeqNo uint32 + + // Node is sent so the target can verify they are + // the intended recipient. This is to protect again an agent + // restart with a new name. + Node string +} + +// indirect ping sent to an indirect ndoe +type indirectPingReq struct { + SeqNo uint32 + Target []byte + Port uint16 + Node string + Nack bool // true if we'd like a nack back +} + +// ack response is sent for a ping +type ackResp struct { + SeqNo uint32 + Payload []byte +} + +// nack response is sent for an indirect ping when the pinger doesn't hear from +// the ping-ee within the configured timeout. This lets the original node know +// that the indirect ping attempt happened but didn't succeed. +type nackResp struct { + SeqNo uint32 +} + +// suspect is broadcast when we suspect a node is dead +type suspect struct { + Incarnation uint32 + Node string + From string // Include who is suspecting +} + +// alive is broadcast when we know a node is alive. +// Overloaded for nodes joining +type alive struct { + Incarnation uint32 + Node string + Addr []byte + Port uint16 + Meta []byte + + // The versions of the protocol/delegate that are being spoken, order: + // pmin, pmax, pcur, dmin, dmax, dcur + Vsn []uint8 +} + +// dead is broadcast when we confirm a node is dead +// Overloaded for nodes leaving +type dead struct { + Incarnation uint32 + Node string + From string // Include who is suspecting +} + +// pushPullHeader is used to inform the +// otherside how many states we are transferring +type pushPullHeader struct { + Nodes int + UserStateLen int // Encodes the byte lengh of user state + Join bool // Is this a join request or a anti-entropy run +} + +// userMsgHeader is used to encapsulate a userMsg +type userMsgHeader struct { + UserMsgLen int // Encodes the byte lengh of user state +} + +// pushNodeState is used for pushPullReq when we are +// transferring out node states +type pushNodeState struct { + Name string + Addr []byte + Port uint16 + Meta []byte + Incarnation uint32 + State nodeStateType + Vsn []uint8 // Protocol versions +} + +// compress is used to wrap an underlying payload +// using a specified compression algorithm +type compress struct { + Algo compressionType + Buf []byte +} + +// msgHandoff is used to transfer a message between goroutines +type msgHandoff struct { + msgType messageType + buf []byte + from net.Addr +} + +// encryptionVersion returns the encryption version to use +func (m *Memberlist) encryptionVersion() encryptionVersion { + switch m.ProtocolVersion() { + case 1: + return 0 + default: + return 1 + } +} + +// streamListen is a long running goroutine that pulls incoming streams from the +// transport and hands them off for processing. +func (m *Memberlist) streamListen() { + for { + select { + case conn := <-m.transport.StreamCh(): + go m.handleConn(conn) + + case <-m.shutdownCh: + return + } + } +} + +// handleConn handles a single incoming stream connection from the transport. +func (m *Memberlist) handleConn(conn net.Conn) { + m.logger.Printf("[DEBUG] memberlist: Stream connection %s", LogConn(conn)) + + defer conn.Close() + metrics.IncrCounter([]string{"memberlist", "tcp", "accept"}, 1) + + conn.SetDeadline(time.Now().Add(m.config.TCPTimeout)) + msgType, bufConn, dec, err := m.readStream(conn) + if err != nil { + if err != io.EOF { + m.logger.Printf("[ERR] memberlist: failed to receive: %s %s", err, LogConn(conn)) + } + return + } + + switch msgType { + case userMsg: + if err := m.readUserMsg(bufConn, dec); err != nil { + m.logger.Printf("[ERR] memberlist: Failed to receive user message: %s %s", err, LogConn(conn)) + } + case pushPullMsg: + join, remoteNodes, userState, err := m.readRemoteState(bufConn, dec) + if err != nil { + m.logger.Printf("[ERR] memberlist: Failed to read remote state: %s %s", err, LogConn(conn)) + return + } + + if err := m.sendLocalState(conn, join); err != nil { + m.logger.Printf("[ERR] memberlist: Failed to push local state: %s %s", err, LogConn(conn)) + return + } + + if err := m.mergeRemoteState(join, remoteNodes, userState); err != nil { + m.logger.Printf("[ERR] memberlist: Failed push/pull merge: %s %s", err, LogConn(conn)) + return + } + case pingMsg: + var p ping + if err := dec.Decode(&p); err != nil { + m.logger.Printf("[ERR] memberlist: Failed to decode ping: %s %s", err, LogConn(conn)) + return + } + + if p.Node != "" && p.Node != m.config.Name { + m.logger.Printf("[WARN] memberlist: Got ping for unexpected node %s %s", p.Node, LogConn(conn)) + return + } + + ack := ackResp{p.SeqNo, nil} + out, err := encode(ackRespMsg, &ack) + if err != nil { + m.logger.Printf("[ERR] memberlist: Failed to encode ack: %s", err) + return + } + + err = m.rawSendMsgStream(conn, out.Bytes()) + if err != nil { + m.logger.Printf("[ERR] memberlist: Failed to send ack: %s %s", err, LogConn(conn)) + return + } + default: + m.logger.Printf("[ERR] memberlist: Received invalid msgType (%d) %s", msgType, LogConn(conn)) + } +} + +// packetListen is a long running goroutine that pulls packets out of the +// transport and hands them off for processing. +func (m *Memberlist) packetListen() { + for { + select { + case packet := <-m.transport.PacketCh(): + m.ingestPacket(packet.Buf, packet.From, packet.Timestamp) + + case <-m.shutdownCh: + return + } + } +} + +func (m *Memberlist) ingestPacket(buf []byte, from net.Addr, timestamp time.Time) { + // Check if encryption is enabled + if m.config.EncryptionEnabled() { + // Decrypt the payload + plain, err := decryptPayload(m.config.Keyring.GetKeys(), buf, nil) + if err != nil { + m.logger.Printf("[ERR] memberlist: Decrypt packet failed: %v %s", err, LogAddress(from)) + return + } + + // Continue processing the plaintext buffer + buf = plain + } + + // See if there's a checksum included to verify the contents of the message + if len(buf) >= 5 && messageType(buf[0]) == hasCrcMsg { + crc := crc32.ChecksumIEEE(buf[5:]) + expected := binary.BigEndian.Uint32(buf[1:5]) + if crc != expected { + m.logger.Printf("[WARN] memberlist: Got invalid checksum for UDP packet: %x, %x", crc, expected) + return + } + m.handleCommand(buf[5:], from, timestamp) + } else { + m.handleCommand(buf, from, timestamp) + } +} + +func (m *Memberlist) handleCommand(buf []byte, from net.Addr, timestamp time.Time) { + // Decode the message type + msgType := messageType(buf[0]) + buf = buf[1:] + + // Switch on the msgType + switch msgType { + case compoundMsg: + m.handleCompound(buf, from, timestamp) + case compressMsg: + m.handleCompressed(buf, from, timestamp) + + case pingMsg: + m.handlePing(buf, from) + case indirectPingMsg: + m.handleIndirectPing(buf, from) + case ackRespMsg: + m.handleAck(buf, from, timestamp) + case nackRespMsg: + m.handleNack(buf, from) + + case suspectMsg: + fallthrough + case aliveMsg: + fallthrough + case deadMsg: + fallthrough + case userMsg: + select { + case m.handoff <- msgHandoff{msgType, buf, from}: + default: + m.logger.Printf("[WARN] memberlist: handler queue full, dropping message (%d) %s", msgType, LogAddress(from)) + } + + default: + m.logger.Printf("[ERR] memberlist: msg type (%d) not supported %s", msgType, LogAddress(from)) + } +} + +// packetHandler is a long running goroutine that processes messages received +// over the packet interface, but is decoupled from the listener to avoid +// blocking the listener which may cause ping/ack messages to be delayed. +func (m *Memberlist) packetHandler() { + for { + select { + case msg := <-m.handoff: + msgType := msg.msgType + buf := msg.buf + from := msg.from + + switch msgType { + case suspectMsg: + m.handleSuspect(buf, from) + case aliveMsg: + m.handleAlive(buf, from) + case deadMsg: + m.handleDead(buf, from) + case userMsg: + m.handleUser(buf, from) + default: + m.logger.Printf("[ERR] memberlist: Message type (%d) not supported %s (packet handler)", msgType, LogAddress(from)) + } + + case <-m.shutdownCh: + return + } + } +} + +func (m *Memberlist) handleCompound(buf []byte, from net.Addr, timestamp time.Time) { + // Decode the parts + trunc, parts, err := decodeCompoundMessage(buf) + if err != nil { + m.logger.Printf("[ERR] memberlist: Failed to decode compound request: %s %s", err, LogAddress(from)) + return + } + + // Log any truncation + if trunc > 0 { + m.logger.Printf("[WARN] memberlist: Compound request had %d truncated messages %s", trunc, LogAddress(from)) + } + + // Handle each message + for _, part := range parts { + m.handleCommand(part, from, timestamp) + } +} + +func (m *Memberlist) handlePing(buf []byte, from net.Addr) { + var p ping + if err := decode(buf, &p); err != nil { + m.logger.Printf("[ERR] memberlist: Failed to decode ping request: %s %s", err, LogAddress(from)) + return + } + // If node is provided, verify that it is for us + if p.Node != "" && p.Node != m.config.Name { + m.logger.Printf("[WARN] memberlist: Got ping for unexpected node '%s' %s", p.Node, LogAddress(from)) + return + } + var ack ackResp + ack.SeqNo = p.SeqNo + if m.config.Ping != nil { + ack.Payload = m.config.Ping.AckPayload() + } + if err := m.encodeAndSendMsg(from.String(), ackRespMsg, &ack); err != nil { + m.logger.Printf("[ERR] memberlist: Failed to send ack: %s %s", err, LogAddress(from)) + } +} + +func (m *Memberlist) handleIndirectPing(buf []byte, from net.Addr) { + var ind indirectPingReq + if err := decode(buf, &ind); err != nil { + m.logger.Printf("[ERR] memberlist: Failed to decode indirect ping request: %s %s", err, LogAddress(from)) + return + } + + // For proto versions < 2, there is no port provided. Mask old + // behavior by using the configured port. + if m.ProtocolVersion() < 2 || ind.Port == 0 { + ind.Port = uint16(m.config.BindPort) + } + + // Send a ping to the correct host. + localSeqNo := m.nextSeqNo() + ping := ping{SeqNo: localSeqNo, Node: ind.Node} + + // Setup a response handler to relay the ack + cancelCh := make(chan struct{}) + respHandler := func(payload []byte, timestamp time.Time) { + // Try to prevent the nack if we've caught it in time. + close(cancelCh) + + // Forward the ack back to the requestor. + ack := ackResp{ind.SeqNo, nil} + if err := m.encodeAndSendMsg(from.String(), ackRespMsg, &ack); err != nil { + m.logger.Printf("[ERR] memberlist: Failed to forward ack: %s %s", err, LogAddress(from)) + } + } + m.setAckHandler(localSeqNo, respHandler, m.config.ProbeTimeout) + + // Send the ping. + addr := joinHostPort(net.IP(ind.Target).String(), ind.Port) + if err := m.encodeAndSendMsg(addr, pingMsg, &ping); err != nil { + m.logger.Printf("[ERR] memberlist: Failed to send ping: %s %s", err, LogAddress(from)) + } + + // Setup a timer to fire off a nack if no ack is seen in time. + if ind.Nack { + go func() { + select { + case <-cancelCh: + return + case <-time.After(m.config.ProbeTimeout): + nack := nackResp{ind.SeqNo} + if err := m.encodeAndSendMsg(from.String(), nackRespMsg, &nack); err != nil { + m.logger.Printf("[ERR] memberlist: Failed to send nack: %s %s", err, LogAddress(from)) + } + } + }() + } +} + +func (m *Memberlist) handleAck(buf []byte, from net.Addr, timestamp time.Time) { + var ack ackResp + if err := decode(buf, &ack); err != nil { + m.logger.Printf("[ERR] memberlist: Failed to decode ack response: %s %s", err, LogAddress(from)) + return + } + m.invokeAckHandler(ack, timestamp) +} + +func (m *Memberlist) handleNack(buf []byte, from net.Addr) { + var nack nackResp + if err := decode(buf, &nack); err != nil { + m.logger.Printf("[ERR] memberlist: Failed to decode nack response: %s %s", err, LogAddress(from)) + return + } + m.invokeNackHandler(nack) +} + +func (m *Memberlist) handleSuspect(buf []byte, from net.Addr) { + var sus suspect + if err := decode(buf, &sus); err != nil { + m.logger.Printf("[ERR] memberlist: Failed to decode suspect message: %s %s", err, LogAddress(from)) + return + } + m.suspectNode(&sus) +} + +func (m *Memberlist) handleAlive(buf []byte, from net.Addr) { + var live alive + if err := decode(buf, &live); err != nil { + m.logger.Printf("[ERR] memberlist: Failed to decode alive message: %s %s", err, LogAddress(from)) + return + } + + // For proto versions < 2, there is no port provided. Mask old + // behavior by using the configured port + if m.ProtocolVersion() < 2 || live.Port == 0 { + live.Port = uint16(m.config.BindPort) + } + + m.aliveNode(&live, nil, false) +} + +func (m *Memberlist) handleDead(buf []byte, from net.Addr) { + var d dead + if err := decode(buf, &d); err != nil { + m.logger.Printf("[ERR] memberlist: Failed to decode dead message: %s %s", err, LogAddress(from)) + return + } + m.deadNode(&d) +} + +// handleUser is used to notify channels of incoming user data +func (m *Memberlist) handleUser(buf []byte, from net.Addr) { + d := m.config.Delegate + if d != nil { + d.NotifyMsg(buf) + } +} + +// handleCompressed is used to unpack a compressed message +func (m *Memberlist) handleCompressed(buf []byte, from net.Addr, timestamp time.Time) { + // Try to decode the payload + payload, err := decompressPayload(buf) + if err != nil { + m.logger.Printf("[ERR] memberlist: Failed to decompress payload: %v %s", err, LogAddress(from)) + return + } + + // Recursively handle the payload + m.handleCommand(payload, from, timestamp) +} + +// encodeAndSendMsg is used to combine the encoding and sending steps +func (m *Memberlist) encodeAndSendMsg(addr string, msgType messageType, msg interface{}) error { + out, err := encode(msgType, msg) + if err != nil { + return err + } + if err := m.sendMsg(addr, out.Bytes()); err != nil { + return err + } + return nil +} + +// sendMsg is used to send a message via packet to another host. It will +// opportunistically create a compoundMsg and piggy back other broadcasts. +func (m *Memberlist) sendMsg(addr string, msg []byte) error { + // Check if we can piggy back any messages + bytesAvail := m.config.UDPBufferSize - len(msg) - compoundHeaderOverhead + if m.config.EncryptionEnabled() { + bytesAvail -= encryptOverhead(m.encryptionVersion()) + } + extra := m.getBroadcasts(compoundOverhead, bytesAvail) + + // Fast path if nothing to piggypack + if len(extra) == 0 { + return m.rawSendMsgPacket(addr, nil, msg) + } + + // Join all the messages + msgs := make([][]byte, 0, 1+len(extra)) + msgs = append(msgs, msg) + msgs = append(msgs, extra...) + + // Create a compound message + compound := makeCompoundMessage(msgs) + + // Send the message + return m.rawSendMsgPacket(addr, nil, compound.Bytes()) +} + +// rawSendMsgPacket is used to send message via packet to another host without +// modification, other than compression or encryption if enabled. +func (m *Memberlist) rawSendMsgPacket(addr string, node *Node, msg []byte) error { + // Check if we have compression enabled + if m.config.EnableCompression { + buf, err := compressPayload(msg) + if err != nil { + m.logger.Printf("[WARN] memberlist: Failed to compress payload: %v", err) + } else { + // Only use compression if it reduced the size + if buf.Len() < len(msg) { + msg = buf.Bytes() + } + } + } + + // Try to look up the destination node + if node == nil { + toAddr, _, err := net.SplitHostPort(addr) + if err != nil { + m.logger.Printf("[ERR] memberlist: Failed to parse address %q: %v", addr, err) + return err + } + m.nodeLock.RLock() + nodeState, ok := m.nodeMap[toAddr] + m.nodeLock.RUnlock() + if ok { + node = &nodeState.Node + } + } + + // Add a CRC to the end of the payload if the recipient understands + // ProtocolVersion >= 5 + if node != nil && node.PMax >= 5 { + crc := crc32.ChecksumIEEE(msg) + header := make([]byte, 5, 5+len(msg)) + header[0] = byte(hasCrcMsg) + binary.BigEndian.PutUint32(header[1:], crc) + msg = append(header, msg...) + } + + // Check if we have encryption enabled + if m.config.EncryptionEnabled() { + // Encrypt the payload + var buf bytes.Buffer + primaryKey := m.config.Keyring.GetPrimaryKey() + err := encryptPayload(m.encryptionVersion(), primaryKey, msg, nil, &buf) + if err != nil { + m.logger.Printf("[ERR] memberlist: Encryption of message failed: %v", err) + return err + } + msg = buf.Bytes() + } + + metrics.IncrCounter([]string{"memberlist", "udp", "sent"}, float32(len(msg))) + _, err := m.transport.WriteTo(msg, addr) + return err +} + +// rawSendMsgStream is used to stream a message to another host without +// modification, other than applying compression and encryption if enabled. +func (m *Memberlist) rawSendMsgStream(conn net.Conn, sendBuf []byte) error { + // Check if compresion is enabled + if m.config.EnableCompression { + compBuf, err := compressPayload(sendBuf) + if err != nil { + m.logger.Printf("[ERROR] memberlist: Failed to compress payload: %v", err) + } else { + sendBuf = compBuf.Bytes() + } + } + + // Check if encryption is enabled + if m.config.EncryptionEnabled() { + crypt, err := m.encryptLocalState(sendBuf) + if err != nil { + m.logger.Printf("[ERROR] memberlist: Failed to encrypt local state: %v", err) + return err + } + sendBuf = crypt + } + + // Write out the entire send buffer + metrics.IncrCounter([]string{"memberlist", "tcp", "sent"}, float32(len(sendBuf))) + + if n, err := conn.Write(sendBuf); err != nil { + return err + } else if n != len(sendBuf) { + return fmt.Errorf("only %d of %d bytes written", n, len(sendBuf)) + } + + return nil +} + +// sendUserMsg is used to stream a user message to another host. +func (m *Memberlist) sendUserMsg(addr string, sendBuf []byte) error { + conn, err := m.transport.DialTimeout(addr, m.config.TCPTimeout) + if err != nil { + return err + } + defer conn.Close() + + bufConn := bytes.NewBuffer(nil) + if err := bufConn.WriteByte(byte(userMsg)); err != nil { + return err + } + + header := userMsgHeader{UserMsgLen: len(sendBuf)} + hd := codec.MsgpackHandle{} + enc := codec.NewEncoder(bufConn, &hd) + if err := enc.Encode(&header); err != nil { + return err + } + if _, err := bufConn.Write(sendBuf); err != nil { + return err + } + return m.rawSendMsgStream(conn, bufConn.Bytes()) +} + +// sendAndReceiveState is used to initiate a push/pull over a stream with a +// remote host. +func (m *Memberlist) sendAndReceiveState(addr string, join bool) ([]pushNodeState, []byte, error) { + // Attempt to connect + conn, err := m.transport.DialTimeout(addr, m.config.TCPTimeout) + if err != nil { + return nil, nil, err + } + defer conn.Close() + m.logger.Printf("[DEBUG] memberlist: Initiating push/pull sync with: %s", conn.RemoteAddr()) + metrics.IncrCounter([]string{"memberlist", "tcp", "connect"}, 1) + + // Send our state + if err := m.sendLocalState(conn, join); err != nil { + return nil, nil, err + } + + conn.SetDeadline(time.Now().Add(m.config.TCPTimeout)) + msgType, bufConn, dec, err := m.readStream(conn) + if err != nil { + return nil, nil, err + } + + // Quit if not push/pull + if msgType != pushPullMsg { + err := fmt.Errorf("received invalid msgType (%d), expected pushPullMsg (%d) %s", msgType, pushPullMsg, LogConn(conn)) + return nil, nil, err + } + + // Read remote state + _, remoteNodes, userState, err := m.readRemoteState(bufConn, dec) + return remoteNodes, userState, err +} + +// sendLocalState is invoked to send our local state over a stream connection. +func (m *Memberlist) sendLocalState(conn net.Conn, join bool) error { + // Setup a deadline + conn.SetDeadline(time.Now().Add(m.config.TCPTimeout)) + + // Prepare the local node state + m.nodeLock.RLock() + localNodes := make([]pushNodeState, len(m.nodes)) + for idx, n := range m.nodes { + localNodes[idx].Name = n.Name + localNodes[idx].Addr = n.Addr + localNodes[idx].Port = n.Port + localNodes[idx].Incarnation = n.Incarnation + localNodes[idx].State = n.State + localNodes[idx].Meta = n.Meta + localNodes[idx].Vsn = []uint8{ + n.PMin, n.PMax, n.PCur, + n.DMin, n.DMax, n.DCur, + } + } + m.nodeLock.RUnlock() + + // Get the delegate state + var userData []byte + if m.config.Delegate != nil { + userData = m.config.Delegate.LocalState(join) + } + + // Create a bytes buffer writer + bufConn := bytes.NewBuffer(nil) + + // Send our node state + header := pushPullHeader{Nodes: len(localNodes), UserStateLen: len(userData), Join: join} + hd := codec.MsgpackHandle{} + enc := codec.NewEncoder(bufConn, &hd) + + // Begin state push + if _, err := bufConn.Write([]byte{byte(pushPullMsg)}); err != nil { + return err + } + + if err := enc.Encode(&header); err != nil { + return err + } + for i := 0; i < header.Nodes; i++ { + if err := enc.Encode(&localNodes[i]); err != nil { + return err + } + } + + // Write the user state as well + if userData != nil { + if _, err := bufConn.Write(userData); err != nil { + return err + } + } + + // Get the send buffer + return m.rawSendMsgStream(conn, bufConn.Bytes()) +} + +// encryptLocalState is used to help encrypt local state before sending +func (m *Memberlist) encryptLocalState(sendBuf []byte) ([]byte, error) { + var buf bytes.Buffer + + // Write the encryptMsg byte + buf.WriteByte(byte(encryptMsg)) + + // Write the size of the message + sizeBuf := make([]byte, 4) + encVsn := m.encryptionVersion() + encLen := encryptedLength(encVsn, len(sendBuf)) + binary.BigEndian.PutUint32(sizeBuf, uint32(encLen)) + buf.Write(sizeBuf) + + // Write the encrypted cipher text to the buffer + key := m.config.Keyring.GetPrimaryKey() + err := encryptPayload(encVsn, key, sendBuf, buf.Bytes()[:5], &buf) + if err != nil { + return nil, err + } + return buf.Bytes(), nil +} + +// decryptRemoteState is used to help decrypt the remote state +func (m *Memberlist) decryptRemoteState(bufConn io.Reader) ([]byte, error) { + // Read in enough to determine message length + cipherText := bytes.NewBuffer(nil) + cipherText.WriteByte(byte(encryptMsg)) + _, err := io.CopyN(cipherText, bufConn, 4) + if err != nil { + return nil, err + } + + // Ensure we aren't asked to download too much. This is to guard against + // an attack vector where a huge amount of state is sent + moreBytes := binary.BigEndian.Uint32(cipherText.Bytes()[1:5]) + if moreBytes > maxPushStateBytes { + return nil, fmt.Errorf("Remote node state is larger than limit (%d)", moreBytes) + } + + // Read in the rest of the payload + _, err = io.CopyN(cipherText, bufConn, int64(moreBytes)) + if err != nil { + return nil, err + } + + // Decrypt the cipherText + dataBytes := cipherText.Bytes()[:5] + cipherBytes := cipherText.Bytes()[5:] + + // Decrypt the payload + keys := m.config.Keyring.GetKeys() + return decryptPayload(keys, cipherBytes, dataBytes) +} + +// readStream is used to read from a stream connection, decrypting and +// decompressing the stream if necessary. +func (m *Memberlist) readStream(conn net.Conn) (messageType, io.Reader, *codec.Decoder, error) { + // Created a buffered reader + var bufConn io.Reader = bufio.NewReader(conn) + + // Read the message type + buf := [1]byte{0} + if _, err := bufConn.Read(buf[:]); err != nil { + return 0, nil, nil, err + } + msgType := messageType(buf[0]) + + // Check if the message is encrypted + if msgType == encryptMsg { + if !m.config.EncryptionEnabled() { + return 0, nil, nil, + fmt.Errorf("Remote state is encrypted and encryption is not configured") + } + + plain, err := m.decryptRemoteState(bufConn) + if err != nil { + return 0, nil, nil, err + } + + // Reset message type and bufConn + msgType = messageType(plain[0]) + bufConn = bytes.NewReader(plain[1:]) + } else if m.config.EncryptionEnabled() { + return 0, nil, nil, + fmt.Errorf("Encryption is configured but remote state is not encrypted") + } + + // Get the msgPack decoders + hd := codec.MsgpackHandle{} + dec := codec.NewDecoder(bufConn, &hd) + + // Check if we have a compressed message + if msgType == compressMsg { + var c compress + if err := dec.Decode(&c); err != nil { + return 0, nil, nil, err + } + decomp, err := decompressBuffer(&c) + if err != nil { + return 0, nil, nil, err + } + + // Reset the message type + msgType = messageType(decomp[0]) + + // Create a new bufConn + bufConn = bytes.NewReader(decomp[1:]) + + // Create a new decoder + dec = codec.NewDecoder(bufConn, &hd) + } + + return msgType, bufConn, dec, nil +} + +// readRemoteState is used to read the remote state from a connection +func (m *Memberlist) readRemoteState(bufConn io.Reader, dec *codec.Decoder) (bool, []pushNodeState, []byte, error) { + // Read the push/pull header + var header pushPullHeader + if err := dec.Decode(&header); err != nil { + return false, nil, nil, err + } + + // Allocate space for the transfer + remoteNodes := make([]pushNodeState, header.Nodes) + + // Try to decode all the states + for i := 0; i < header.Nodes; i++ { + if err := dec.Decode(&remoteNodes[i]); err != nil { + return false, nil, nil, err + } + } + + // Read the remote user state into a buffer + var userBuf []byte + if header.UserStateLen > 0 { + userBuf = make([]byte, header.UserStateLen) + bytes, err := io.ReadAtLeast(bufConn, userBuf, header.UserStateLen) + if err == nil && bytes != header.UserStateLen { + err = fmt.Errorf( + "Failed to read full user state (%d / %d)", + bytes, header.UserStateLen) + } + if err != nil { + return false, nil, nil, err + } + } + + // For proto versions < 2, there is no port provided. Mask old + // behavior by using the configured port + for idx := range remoteNodes { + if m.ProtocolVersion() < 2 || remoteNodes[idx].Port == 0 { + remoteNodes[idx].Port = uint16(m.config.BindPort) + } + } + + return header.Join, remoteNodes, userBuf, nil +} + +// mergeRemoteState is used to merge the remote state with our local state +func (m *Memberlist) mergeRemoteState(join bool, remoteNodes []pushNodeState, userBuf []byte) error { + if err := m.verifyProtocol(remoteNodes); err != nil { + return err + } + + // Invoke the merge delegate if any + if join && m.config.Merge != nil { + nodes := make([]*Node, len(remoteNodes)) + for idx, n := range remoteNodes { + nodes[idx] = &Node{ + Name: n.Name, + Addr: n.Addr, + Port: n.Port, + Meta: n.Meta, + PMin: n.Vsn[0], + PMax: n.Vsn[1], + PCur: n.Vsn[2], + DMin: n.Vsn[3], + DMax: n.Vsn[4], + DCur: n.Vsn[5], + } + } + if err := m.config.Merge.NotifyMerge(nodes); err != nil { + return err + } + } + + // Merge the membership state + m.mergeState(remoteNodes) + + // Invoke the delegate for user state + if userBuf != nil && m.config.Delegate != nil { + m.config.Delegate.MergeRemoteState(userBuf, join) + } + return nil +} + +// readUserMsg is used to decode a userMsg from a stream. +func (m *Memberlist) readUserMsg(bufConn io.Reader, dec *codec.Decoder) error { + // Read the user message header + var header userMsgHeader + if err := dec.Decode(&header); err != nil { + return err + } + + // Read the user message into a buffer + var userBuf []byte + if header.UserMsgLen > 0 { + userBuf = make([]byte, header.UserMsgLen) + bytes, err := io.ReadAtLeast(bufConn, userBuf, header.UserMsgLen) + if err == nil && bytes != header.UserMsgLen { + err = fmt.Errorf( + "Failed to read full user message (%d / %d)", + bytes, header.UserMsgLen) + } + if err != nil { + return err + } + + d := m.config.Delegate + if d != nil { + d.NotifyMsg(userBuf) + } + } + + return nil +} + +// sendPingAndWaitForAck makes a stream connection to the given address, sends +// a ping, and waits for an ack. All of this is done as a series of blocking +// operations, given the deadline. The bool return parameter is true if we +// we able to round trip a ping to the other node. +func (m *Memberlist) sendPingAndWaitForAck(addr string, ping ping, deadline time.Time) (bool, error) { + conn, err := m.transport.DialTimeout(addr, m.config.TCPTimeout) + if err != nil { + // If the node is actually dead we expect this to fail, so we + // shouldn't spam the logs with it. After this point, errors + // with the connection are real, unexpected errors and should + // get propagated up. + return false, nil + } + defer conn.Close() + conn.SetDeadline(deadline) + + out, err := encode(pingMsg, &ping) + if err != nil { + return false, err + } + + if err = m.rawSendMsgStream(conn, out.Bytes()); err != nil { + return false, err + } + + msgType, _, dec, err := m.readStream(conn) + if err != nil { + return false, err + } + + if msgType != ackRespMsg { + return false, fmt.Errorf("Unexpected msgType (%d) from ping %s", msgType, LogConn(conn)) + } + + var ack ackResp + if err = dec.Decode(&ack); err != nil { + return false, err + } + + if ack.SeqNo != ping.SeqNo { + return false, fmt.Errorf("Sequence number from ack (%d) doesn't match ping (%d)", ack.SeqNo, ping.SeqNo, LogConn(conn)) + } + + return true, nil +} |