unmarshal addressList

pkg/network/message.go

@@ -5,6 +5,7 @@ import (
 	"crypto/sha256"
 	"encoding/binary"
 	"errors"
+	"fmt"
 	"io"
 
 	"github.com/anthdm/neo-go/pkg/network/payload"
@@ -137,10 +138,15 @@ func (m *Message) commandType() commandType {
 func (m *Message) decode(r io.Reader) error {
 	// 24 bytes for the fixed sized fields.
 	buf := make([]byte, minMessageSize)
-	if _, err := r.Read(buf); err != nil {
+	n, err := r.Read(buf)
+	if err != nil {
 		return err
 	}
 
+	if n != minMessageSize {
+		return fmt.Errorf("Expected to read exactly %d bytes got %d", minMessageSize, n)
+	}
+
 	m.Magic = NetMode(binary.LittleEndian.Uint32(buf[0:4]))
 	m.Command = buf[4:16]
 	m.Length = binary.LittleEndian.Uint32(buf[16:20])
@@ -156,10 +162,18 @@ func (m *Message) decode(r io.Reader) error {
 
 func (m *Message) unmarshalPayload(r io.Reader) error {
 	pbuf := make([]byte, m.Length)
-	if _, err := r.Read(pbuf); err != nil {
+	n, err := r.Read(pbuf)
+	if err != nil {
 		return err
 	}
 
+	fmt.Printf("incomming payload: %d bytes\n", len(pbuf))
+	fmt.Println(pbuf)
+
+	if uint32(n) != m.Length {
+		return fmt.Errorf("expected to have read exactly %d bytes got %d", m.Length, n)
+	}
+
 	// Compare the checksum of the payload.
 	if !compareChecksum(m.Checksum, pbuf) {
 		return errors.New("checksum mismatch error")
@@ -177,6 +191,11 @@ func (m *Message) unmarshalPayload(r io.Reader) error {
 		if err := p.UnmarshalBinary(pbuf); err != nil {
 			return err
 		}
+	case cmdAddr:
+		p = &payload.AddressList{}
+		if err := p.UnmarshalBinary(pbuf); err != nil {
+			return err
+		}
 	}
 
 	m.Payload = p
@@ -201,10 +220,24 @@ func (m *Message) encode(w io.Writer) error {
 		copy(buf[minMessageSize:minMessageSize+m.Length], payload)
 	}
 
-	if _, err := w.Write(buf); err != nil {
+	n, err := w.Write(buf)
+	if err != nil {
 		return err
 	}
 
+	// safety check to if we have written enough bytes.
+	if m.Length > 0 {
+		expectWritten := minMessageSize + m.Length
+		if uint32(n) != expectWritten {
+			return fmt.Errorf("expected to written exactly %d did %d", expectWritten, n)
+		}
+	} else {
+		expectWritten := minMessageSize
+		if n != expectWritten {
+			return fmt.Errorf("expected to written exactly %d did %d", expectWritten, n)
+		}
+	}
+
 	return nil
 }
 

pkg/network/payload/addr.go

@@ -1,37 +1,70 @@
 package payload
 
 import (
-	"io"
-	"net"
-	"unsafe"
+	"bytes"
+	"encoding/binary"
 )
 
+// Endpoint host + port of a node.
+type Endpoint struct {
+	IP   [16]byte // TODO: make a uint128 type
+	Port uint16
+}
+
 // AddrWithTime payload
 type AddrWithTime struct {
 	Timestamp uint32
 	Services  uint64
-	Addr      net.Addr
+	Addr      Endpoint
 }
 
+// Size implements the payloader interface.
 func (p *AddrWithTime) Size() uint32 {
-	return 4 + 8 + uint32(unsafe.Sizeof(p.Addr))
+	return 30
 }
 
-func (p *AddrWithTime) Encode(r io.Reader) error {
+// UnmarshalBinary implements the Payloader interface.
+func (p *AddrWithTime) UnmarshalBinary(b []byte) error {
+	p.Timestamp = binary.LittleEndian.Uint32(b[0:4])
+	p.Services = binary.LittleEndian.Uint64(b[4:12])
+	binary.Read(bytes.NewReader(b[12:28]), binary.BigEndian, &p.Addr.IP)
+	p.Addr.Port = binary.LittleEndian.Uint16(b[28:30])
 	return nil
 }
 
-func (p *AddrWithTime) Decode(w io.Writer) error {
+// MarshalBinary implements the Payloader interface.
+func (p *AddrWithTime) MarshalBinary() ([]byte, error) {
+	return nil, nil
+}
+
+// AddressList contains a slice of AddrWithTime.
+type AddressList struct {
+	Addrs []*AddrWithTime
+}
+
+// UnmarshalBinary implements the Payloader interface.
+func (p *AddressList) UnmarshalBinary(b []byte) error {
+	var lenList uint8
+	binary.Read(bytes.NewReader(b[0:1]), binary.LittleEndian, &lenList)
+
+	offset := 1 // skip the uint8 length byte.
+	size := 30  // size of AddrWithTime
+	for i := 0; i < int(lenList); i++ {
+		address := &AddrWithTime{}
+		address.UnmarshalBinary(b[offset : offset+size])
+		p.Addrs = append(p.Addrs, address)
+		offset += size
+	}
+
 	return nil
 }
 
-// AddressList is a slice of AddrWithTime.
-type AddressList []*AddrWithTime
-
-func (p AddressList) Encode(r io.Reader) error {
-	return nil
+// MarshalBinary implements the Payloader interface.
+func (p *AddressList) MarshalBinary() ([]byte, error) {
+	return nil, nil
 }
 
-func (p AddressList) Decode(w io.Writer) error {
-	return nil
+// Size implements the Payloader interface.
+func (p *AddressList) Size() uint32 {
+	return uint32(len(p.Addrs) * 30)
 }

pkg/network/payload/inventory.go

@@ -3,6 +3,7 @@ package payload
 import (
 	"bytes"
 	"encoding/binary"
+	"fmt"
 
 	. "github.com/anthdm/neo-go/pkg/util"
 )
@@ -47,6 +48,8 @@ func (p *Inventory) UnmarshalBinary(b []byte) error {
 	// TODO: what byte is [1:2] ?
 	// We have 1 byte for the type which is uint8 and 32 for the hash.
 	// There is 1 byte left over.
+	fmt.Println(b[0:1])
+	fmt.Println(b[1:2])
 	binary.Read(bytes.NewReader(b), binary.LittleEndian, &p.Type)
 	p.Hash.UnmarshalBinary(b[2:len(b)])
 	return nil

pkg/network/payload/version.go

@@ -5,8 +5,7 @@ import (
 )
 
 const (
-	lenUA          = 12
-	minVersionSize = 27 + lenUA
+	minVersionSize = 27
 )
 
 // Version payload.
@@ -21,7 +20,7 @@ type Version struct {
 	Port uint16
 	// it's used to distinguish the node from public IP
 	Nonce uint32
-	// client id currently 12 bytes \v/NEO:2.6.0/
+	// client id
 	UserAgent []byte
 	// Height of the block chain
 	StartHeight uint32
@@ -45,6 +44,12 @@ func NewVersion(id uint32, p uint16, ua string, h uint32, r bool) *Version {
 
 // UnmarshalBinary implements the Payloader interface.
 func (p *Version) UnmarshalBinary(b []byte) error {
+	// Length of the user agent should be calculated dynamicaly.
+	// There is no information about the size or format of this.
+	// the only thing we know is by looking at the #c source code.
+	// /NEO:{0}/ => /NEO:2.6.0/
+	lenUA := len(b) - minVersionSize
+
 	p.Version = binary.LittleEndian.Uint32(b[0:4])
 	p.Services = binary.LittleEndian.Uint64(b[4:12])
 	p.Timestamp = binary.LittleEndian.Uint32(b[12:16])
@@ -87,6 +92,7 @@ func (p *Version) MarshalBinary() ([]byte, error) {
 	return b, nil
 }
 
+// Size implements the payloader interface.
 func (p *Version) Size() uint32 {
 	return uint32(minVersionSize + len(p.UserAgent))
 }

pkg/network/server.go

@@ -7,6 +7,7 @@ import (
 	"net"
 	"os"
 	"strconv"
+	"time"
 
 	"github.com/anthdm/neo-go/pkg/network/payload"
 	"github.com/anthdm/neo-go/pkg/util"
@@ -182,6 +183,7 @@ func (s *Server) processMessage(msg *Message, peer *Peer) error {
 	case cmdGetAddr:
 		return s.handleGetAddrCmd(msg, peer)
 	case cmdAddr:
+		return s.handleAddrCmd(msg.Payload.(*payload.AddressList), peer)
 	case cmdGetHeaders:
 	case cmdHeaders:
 	case cmdGetBlocks:
@@ -220,6 +222,12 @@ func (s *Server) handleVersionCmd(v *payload.Version, peer *Peer) error {
 	verackMsg := newMessage(s.net, cmdVerack, nil)
 	peer.send <- verackMsg
 
+	go s.startProtocol(peer)
+
+	return nil
+}
+
+func (s *Server) handleAddrCmd(addrList *payload.AddressList, peer *Peer) error {
 	return nil
 }
 
@@ -240,6 +248,15 @@ func (s *Server) handleGetAddrCmd(msg *Message, peer *Peer) error {
 	return nil
 }
 
+func (s *Server) startProtocol(peer *Peer) {
+	for {
+		getaddrMsg := newMessage(s.net, cmdGetAddr, nil)
+		peer.send <- getaddrMsg
+
+		time.Sleep(10 * time.Second)
+	}
+}
+
 func logo() string {
 	return `
     _   ____________        __________ 

pkg/network/tcp.go

@@ -52,8 +52,8 @@ func handleConnection(s *Server, conn net.Conn, initiated bool) {
 
 	// Read from the connection and decode it into an RPCMessage and
 	// tell the server there is message available for proccesing.
-	for {
 	msg := &Message{}
+	for {
 		if err := msg.decode(conn); err != nil {
 			// remote connection probably closed.
 			if err == io.EOF {