Initial structure and implementation

Author: agaffney

.gitignore

@@ -4,6 +4,7 @@
 *.dll
 *.so
 *.dylib
+/go-ouroboros-network
 
 # Test binary, built with `go test -c`
 *.test

Makefile

@@ -0,0 +1,22 @@
+BINARY=go-ouroboros-network
+
+# Determine root directory
+ROOT_DIR=$(shell dirname $(realpath $(firstword $(MAKEFILE_LIST))))
+
+# Gather all .go files for use in dependencies below
+GO_FILES=$(shell find $(ROOT_DIR) -name '*.go')
+
+# Build our program binary
+# Depends on GO_FILES to determine when rebuild is needed
+$(BINARY): $(GO_FILES)
+	# Needed to fetch new dependencies and add them to go.mod
+	go mod tidy
+	go build -o $(BINARY) ./cmd/$(BINARY)
+
+.PHONY: build image
+
+# Alias for building program binary
+build: $(BINARY)
+
+clean:
+	rm -f $(BINARY)

README.md

@@ -1,2 +1,5 @@
-# go-ouroboros
-A Go client implementation of the Cardano Ouroboros protocol
+# go-ouroboros-network
+
+A Go client implementation of the Cardano Ouroboros network protocol
+
+This is loosely based on the [official Haskell implementation](https://github.com/input-output-hk/ouroboros-network)

cmd/go-ouroboros-network/main.go

@@ -0,0 +1,88 @@
+package main
+
+import (
+	"crypto/tls"
+	"flag"
+	"fmt"
+	"github.com/cloudstruct/go-ouroboros-network"
+	"io"
+	"net"
+	"os"
+)
+
+const (
+	TESTNET_MAGIC = 1097911063
+	MAINNET_MAGIC = 764824073
+)
+
+type cmdFlags struct {
+	socket       string
+	address      string
+	useTls       bool
+	networkMagic int
+	testnet      bool
+	mainnet      bool
+}
+
+func main() {
+	f := cmdFlags{}
+	flag.StringVar(&f.socket, "socket", "", "UNIX socket path to connect to")
+	flag.StringVar(&f.address, "address", "", "TCP address to connect to in address:port format")
+	flag.BoolVar(&f.useTls, "tls", false, "enable TLS")
+	flag.IntVar(&f.networkMagic, "network-magic", 0, "network magic value")
+	flag.BoolVar(&f.testnet, "testnet", false, fmt.Sprintf("alias for -network-magic=%d", TESTNET_MAGIC))
+	flag.BoolVar(&f.mainnet, "mainnet", false, fmt.Sprintf("alias for -network-magic=%d", MAINNET_MAGIC))
+	flag.Parse()
+
+	var conn io.ReadWriteCloser
+	var err error
+	var dialProto string
+	var dialAddress string
+	if f.socket != "" {
+		dialProto = "unix"
+		dialAddress = f.socket
+	} else if f.address != "" {
+		dialProto = "tcp"
+		dialAddress = f.address
+	} else {
+		fmt.Printf("You must specify one of -socket or -address\n\n")
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+	if f.useTls {
+		conn, err = tls.Dial(dialProto, dialAddress, nil)
+	} else {
+		conn, err = net.Dial(dialProto, dialAddress)
+	}
+	if err != nil {
+		fmt.Printf("Connection failed: %s\n", err)
+		os.Exit(1)
+	}
+	if f.networkMagic == 0 {
+		if f.testnet {
+			f.networkMagic = TESTNET_MAGIC
+		} else if f.mainnet {
+			f.networkMagic = MAINNET_MAGIC
+		} else {
+			fmt.Printf("You must specify one of -testnet, -mainnet, or -network-magic\n\n")
+			flag.PrintDefaults()
+			os.Exit(1)
+		}
+	}
+	oOpts := &ouroboros.OuroborosOptions{
+		Conn:         conn,
+		NetworkMagic: uint32(f.networkMagic),
+	}
+	o, err := ouroboros.New(oOpts)
+	if err != nil {
+		fmt.Printf("ERROR: %s\n", err)
+		os.Exit(1)
+	}
+	go func() {
+		for {
+			err := <-o.ErrorChan
+			fmt.Printf("ERROR: %s\n", err)
+			os.Exit(1)
+		}
+	}()
+}

go.mod

@@ -0,0 +1,5 @@
+module github.com/cloudstruct/go-ouroboros-network
+
+go 1.16
+
+require github.com/fxamacker/cbor/v2 v2.3.0

go.sum

@@ -0,0 +1,4 @@
+github.com/fxamacker/cbor/v2 v2.3.0 h1:aM45YGMctNakddNNAezPxDUpv38j44Abh+hifNuqXik=
+github.com/fxamacker/cbor/v2 v2.3.0/go.mod h1:TA1xS00nchWmaBnEIxPSE5oHLuJBAVvqrtAnWBwBCVo=
+github.com/x448/float16 v0.8.4 h1:qLwI1I70+NjRFUR3zs1JPUCgaCXSh3SW62uAKT1mSBM=
+github.com/x448/float16 v0.8.4/go.mod h1:14CWIYCyZA/cWjXOioeEpHeN/83MdbZDRQHoFcYsOfg=

handshake/handshake.go

@@ -0,0 +1,100 @@
+package handshake
+
+import (
+	"fmt"
+	"github.com/cloudstruct/go-ouroboros-network/utils"
+)
+
+const (
+	PROTOCOL_ID_SENDER             = 0x0000
+	PROTOCOL_ID_RECEIVER           = 0x8000
+	MESSAGE_TYPE_REQUEST           = 0
+	MESSAGE_TYPE_RESPONSE_ACCEPT   = 1
+	MESSAGE_TYPE_RESPONSE_REFUSE   = 2
+	REFUSE_REASON_VERSION_MISMATCH = 0
+	REFUSE_REASON_DECODE_ERROR     = 1
+	REFUSE_REASON_REFUSED          = 2
+)
+
+type handshakeMessage struct {
+	_           struct{} `cbor:",toarray"`
+	MessageType uint8
+}
+
+type handshakeRequest struct {
+	handshakeMessage
+	VersionMap map[uint16]uint32
+}
+
+type handshakeResponseAccept struct {
+	handshakeMessage
+	Version      uint16
+	NetworkMagic uint32
+}
+
+type handshakeResponseRefuse struct {
+	handshakeMessage
+	Reason []interface{}
+}
+
+type Handshake struct {
+	sendChan chan []byte
+	recvChan chan []byte
+}
+
+func New(sendChan chan []byte, recvChan chan []byte) *Handshake {
+	h := &Handshake{
+		sendChan: sendChan,
+		recvChan: recvChan,
+	}
+	return h
+}
+
+func (h *Handshake) Start(versions []uint16, networkMagic uint32) (uint16, error) {
+	// Create our request
+	versionMap := make(map[uint16]uint32)
+	for _, version := range versions {
+		versionMap[version] = networkMagic
+	}
+	data := handshakeRequest{
+		handshakeMessage: handshakeMessage{
+			MessageType: MESSAGE_TYPE_REQUEST,
+		},
+		VersionMap: versionMap,
+	}
+	dataBytes, err := utils.CborEncode(data)
+	if err != nil {
+		return 0, err
+	}
+	// Send request
+	h.sendChan <- dataBytes
+	// Wait for response
+	respBytes := <-h.recvChan
+	// Decode response into generic list until we can determine what type of response it is
+	var resp []interface{}
+	if err := utils.CborDecode(respBytes, &resp); err != nil {
+		return 0, err
+	}
+	switch resp[0].(uint64) {
+	case MESSAGE_TYPE_RESPONSE_ACCEPT:
+		var respAccept handshakeResponseAccept
+		if err := utils.CborDecode(respBytes, &respAccept); err != nil {
+			return 0, err
+		}
+		return respAccept.Version, nil
+	case MESSAGE_TYPE_RESPONSE_REFUSE:
+		var respRefuse handshakeResponseRefuse
+		if err := utils.CborDecode(respBytes, &respRefuse); err != nil {
+			return 0, err
+		}
+		switch respRefuse.Reason[0].(uint64) {
+		case REFUSE_REASON_VERSION_MISMATCH:
+			return 0, fmt.Errorf("handshake failed: version mismatch")
+		case REFUSE_REASON_DECODE_ERROR:
+			return 0, fmt.Errorf("handshake failed: decode error: %s", respRefuse.Reason[2].(string))
+		case REFUSE_REASON_REFUSED:
+			return 0, fmt.Errorf("handshake failed: refused: %s", respRefuse.Reason[2].(string))
+		}
+	}
+	return 0, fmt.Errorf("unexpected failure")
+}

muxer.go

@@ -0,0 +1,107 @@
+package ouroboros
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+	"time"
+)
+
+type MessageHeader struct {
+	Timestamp     uint32
+	ProtocolId    uint16
+	PayloadLength uint16
+}
+
+type Message struct {
+	MessageHeader
+	Payload []byte
+}
+
+func newMessage(protocolId uint16, payload []byte) (*Message, error) {
+	msgHeader := MessageHeader{
+		Timestamp:  uint32(time.Now().UnixNano() & 0xffffffff),
+		ProtocolId: protocolId,
+	}
+	msgHeader.PayloadLength = uint16(len(payload))
+	msg := &Message{
+		MessageHeader: msgHeader,
+		Payload:       payload,
+	}
+	return msg, nil
+}
+
+type Muxer struct {
+	conn              io.ReadWriteCloser
+	errorChan         chan error
+	respChan          chan *Message
+	protocolSenders   map[uint16]chan []byte
+	protocolReceivers map[uint16]chan []byte
+}
+
+func NewMuxer(conn io.ReadWriteCloser) *Muxer {
+	m := &Muxer{
+		conn:              conn,
+		errorChan:         make(chan error, 10),
+		respChan:          make(chan *Message, 10),
+		protocolSenders:   make(map[uint16]chan []byte),
+		protocolReceivers: make(map[uint16]chan []byte),
+	}
+	go m.readLoop()
+	return m
+}
+
+func (m *Muxer) registerProtocol(senderProtocolId uint16, receiverProtocolId uint16) (chan []byte, chan []byte) {
+	// Generate channels
+	senderChan := make(chan []byte, 10)
+	receiverChan := make(chan []byte, 10)
+	// Record channels in protocol sender/receiver maps
+	m.protocolSenders[senderProtocolId] = senderChan
+	m.protocolReceivers[receiverProtocolId] = receiverChan
+	// Start Goroutine to handle outbound messages
+	go func() {
+		for {
+			payload := <-senderChan
+			m.Send(senderProtocolId, payload)
+		}
+	}()
+	return senderChan, receiverChan
+}
+
+func (m *Muxer) Send(protocolId uint16, payload []byte) error {
+	msg, err := newMessage(protocolId, payload)
+	if err != nil {
+		return err
+	}
+	buf := &bytes.Buffer{}
+	err = binary.Write(buf, binary.BigEndian, msg.MessageHeader)
+	if err != nil {
+		return err
+	}
+	buf.Write(msg.Payload)
+	_, err = m.conn.Write(buf.Bytes())
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (m *Muxer) readLoop() {
+	for {
+		msgHeader := MessageHeader{}
+		if err := binary.Read(m.conn, binary.BigEndian, &msgHeader); err != nil {
+			m.errorChan <- err
+		}
+		msg := &Message{
+			MessageHeader: msgHeader,
+			Payload:       make([]byte, msgHeader.PayloadLength),
+		}
+		// We use ReadFull because it guarantees to read the expected number of bytes or
+		// return an error
+		if _, err := io.ReadFull(m.conn, msg.Payload); err != nil {
+			m.errorChan <- err
+		}
+		// Send message payload to proper receiver
+		m.protocolReceivers[msgHeader.ProtocolId] <- msg.Payload
+	}
+}