wip implement inv command

pkg/network/addr_payload.go

@@ -1,25 +0,0 @@
-package network
-
-import "net"
-
-// AddrWithTimestamp payload.
-type AddrWithTimestamp struct {
-	t        uint32
-	services uint64
-	endpoint net.Addr
-}
-
-func newAddrWithTimestampFromPeer(p *Peer) AddrWithTimestamp {
-	return AddrWithTimestamp{
-		t:        1223345,
-		services: 1,
-		endpoint: p.conn.RemoteAddr(),
-	}
-}
-
-// AddrPayload container a list of known peer addresses.
-type AddrPayload []AddrWithTimestamp
-
-func (p AddrPayload) encode() ([]byte, error) {
-	return nil, nil
-}

pkg/network/message.go

@@ -5,6 +5,7 @@ import (
 	"crypto/sha256"
 	"encoding/binary"
 	"errors"
+	"fmt"
 	"io"
 
 	"github.com/anthdm/neo-go/pkg/network/payload"
@@ -92,23 +93,6 @@ func newMessage(magic NetMode, cmd commandType, p payload.Payloader) *Message {
 	}
 }
 
-func TeeWriter(w io.Writer, r io.Reader) io.Writer {
-	return &teeWriter{w, r}
-}
-
-type teeWriter struct {
-	w io.Writer
-	r io.Reader
-}
-
-func (w *teeWriter) Write(b []byte) (n int, err error) {
-	n, err = w.w.Write(b)
-	if n > 0 {
-		n, err = w.r.Read(b[:n])
-	}
-	return
-}
-
 // Converts the 12 byte command slice to a commandType.
 func (m *Message) commandType() commandType {
 	cmd := string(bytes.TrimRight(m.Command, "\x00"))
@@ -153,11 +137,16 @@ func (m *Message) decode(r io.Reader) error {
 	m.Length = binary.LittleEndian.Uint32(buf[16:20])
 	m.Checksum = binary.LittleEndian.Uint32(buf[20:24])
 
-	// payload is 0, so dont decode it.
-	if m.Length == 0 {
+	// if their is no payload.
+	if m.Length == 0 || !needPayloadDecode(m.commandType()) {
 		return nil
 	}
 
+	return m.decodePayload(r)
+}
+
+func (m *Message) decodePayload(r io.Reader) error {
+	// write to a buffer what we read to calculate the checksum.
 	buffer := new(bytes.Buffer)
 	tr := io.TeeReader(r, buffer)
 	var p payload.Payloader
@@ -168,6 +157,8 @@ func (m *Message) decode(r io.Reader) error {
 		if err := p.Decode(tr); err != nil {
 			return err
 		}
+	default:
+		return fmt.Errorf("unknown command to decode: %s", m.commandType())
 	}
 
 	// Compare the checksum of the payload.
@@ -186,14 +177,18 @@ func (m *Message) encode(w io.Writer) error {
 	pbuf := new(bytes.Buffer)
 
 	// if there is a payload fill its allocated buffer.
+	var checksum []byte
 	if m.Payload != nil {
 		if err := m.Payload.Encode(pbuf); err != nil {
 			return err
 		}
-		checksum := sumSHA256(sumSHA256(pbuf.Bytes()))[:4]
-		m.Checksum = binary.LittleEndian.Uint32(checksum)
+		checksum = sumSHA256(sumSHA256(pbuf.Bytes()))[:4]
+	} else {
+		checksum = sumSHA256(sumSHA256([]byte{}))[:4]
 	}
 
+	m.Checksum = binary.LittleEndian.Uint32(checksum)
+
 	// fill the message buffer
 	binary.LittleEndian.PutUint32(buf[0:4], uint32(m.Magic))
 	copy(buf[4:16], m.Command)
@@ -243,6 +238,10 @@ func cmdToByteSlice(cmd commandType) []byte {
 	return b
 }
 
+func needPayloadDecode(cmd commandType) bool {
+	return cmd != cmdVerack && cmd != cmdGetAddr
+}
+
 func sumSHA256(b []byte) []byte {
 	h := sha256.New()
 	h.Write(b)

pkg/network/message_test.go

@@ -68,20 +68,20 @@ func TestMessageEncodeDecodeWithVersion(t *testing.T) {
 	t.Log(p1)
 }
 
-// func TestMessageInvalidChecksum(t *testing.T) {
-// 	m := newMessage(ModeTestNet, cmdVersion, []byte{})
-// 	m.Checksum = 1337
+func TestMessageInvalidChecksum(t *testing.T) {
+	m := newMessage(ModeTestNet, cmdVersion, nil)
+	m.Checksum = 1337
 
-// 	buf := &bytes.Buffer{}
-// 	if err := m.encode(buf); err != nil {
-// 		t.Error(err)
-// 	}
+	buf := &bytes.Buffer{}
+	if err := m.encode(buf); err != nil {
+		t.Error(err)
+	}
 
-// 	md := &Message{}
-// 	if err := md.decode(buf); err == nil {
-// 		t.Error("decode should failed with checkum mismatch error")
-// 	}
-// }
+	md := &Message{}
+	if err := md.decode(buf); err == nil {
+		t.Error("decode should failed with checkum mismatch error")
+	}
+}
 
 // func TestNewVersionPayload(t *testing.T) {
 // 	ua := "/neo/0.0.1/"

pkg/network/payload/payloader.go

@@ -2,18 +2,10 @@ package payload
 
 import "io"
 
-// Nothing is a safe non payload.
-var Nothing = nothing{}
-
-// Payloader ..
+// Payloader is anything that can be binary encoded and decoded.
+// Every payload used in messages need to satisfy the Payloader interface.
 type Payloader interface {
 	Encode(io.Writer) error
 	Decode(io.Reader) error
 	Size() uint32
 }
-
-type nothing struct{}
-
-func (p nothing) Encode(w io.Writer) error { return nil }
-func (p nothing) Decode(R io.Reader) error { return nil }
-func (p nothing) Size() uint32             { return 0 }

pkg/network/payload/version.go

@@ -1,12 +1,14 @@
 package payload
 
 import (
-	"bytes"
 	"encoding/binary"
 	"io"
 )
 
-const minVersionSize = 27
+const (
+	lenUA          = 12
+	minVersionSize = 27 + lenUA
+)
 
 // Version payload.
 type Version struct {
@@ -20,7 +22,7 @@ type Version struct {
 	Port uint16
 	// it's used to distinguish the node from public IP
 	Nonce uint32
-	// client id currently 6 bytes \v/NEO:2.6.0/
+	// client id currently 12 bytes \v/NEO:2.6.0/
 	UserAgent []byte
 	// Height of the block chain
 	StartHeight uint32
@@ -42,20 +44,19 @@ func NewVersion(p uint16, ua string, h uint32, r bool) *Version {
 	}
 }
 
-// Size ..
+// Size implements the Payloader interface.
 func (p *Version) Size() uint32 {
-	n := minVersionSize + len(p.UserAgent)
+	n := minVersionSize
 	return uint32(n)
 }
 
-// Decode ..
+// Decode implements the Payloader interface.
 func (p *Version) Decode(r io.Reader) error {
-	buf := new(bytes.Buffer)
-	if _, err := buf.ReadFrom(r); err != nil {
+	b := make([]byte, minVersionSize)
+	if _, err := r.Read(b); err != nil {
 		return err
 	}
 
-	b := buf.Bytes()
 	// 27 bytes for the fixed size fields + the length of the user agent
 	// which is kinda variable, according to the docs.
 	lenUA := len(b) - minVersionSize
@@ -75,7 +76,7 @@ func (p *Version) Decode(r io.Reader) error {
 	return nil
 }
 
-// Encode ..
+// Encode implements the Payloader interface.
 func (p *Version) Encode(w io.Writer) error {
 	buf := make([]byte, p.Size())
 

pkg/network/peer.go

@@ -38,7 +38,7 @@ func (p *Peer) writeLoop() {
 
 	for {
 		msg := <-p.send
-		rpcLogger.Printf("OUT :: %+v", msg)
+		rpcLogger.Printf("OUT :: %s", msg.commandType())
 		if err := msg.encode(p.conn); err != nil {
 			log.Printf("encode error: %s", err)
 		}

pkg/network/server.go

@@ -167,11 +167,7 @@ func (s *Server) processMessage(msg *Message, peer *Peer) error {
 
 	switch msg.commandType() {
 	case cmdVersion:
-		// v, err := msg.decodePayload()
-		// if err != nil {
-		// 	return err
-		// }
-		// return s.handleVersionCmd(v.(*Version), peer)
+		return s.handleVersionCmd(msg.Payload.(*payload.Version), peer)
 	case cmdVerack:
 	case cmdGetAddr:
 		return s.handleGetAddrCmd(msg, peer)
@@ -226,10 +222,10 @@ func (s *Server) handleGetAddrCmd(msg *Message, peer *Peer) error {
 	// if err != nil {
 	// 	return err
 	// }
-	var addrList []AddrWithTimestamp
-	for peer := range s.peers {
-		addrList = append(addrList, newAddrWithTimestampFromPeer(peer))
-	}
+	// var addrList []AddrWithTimestamp
+	// for peer := range s.peers {
+	// 	addrList = append(addrList, newAddrWithTimestampFromPeer(peer))
+	// }
 
 	return nil
 }