1 files changed, 180 insertions, 0 deletions
diff --git a/ethwire/messaging.go b/ethwire/messaging.go
new file mode 100644
index 000000000..651bf4710
--- /dev/null
+++ b/ethwire/messaging.go
@@ -0,0 +1,180 @@
+package ethwire
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"github.com/ethereum/eth-go/ethutil"
+	"net"
+	"time"
+)
+
+// Message:
+// [4 bytes token] RLP([TYPE, DATA])
+// Refer to http://wiki.ethereum.org/index.php/Wire_Protocol
+
+// The magic token which should be the first 4 bytes of every message.
+var MagicToken = []byte{34, 64, 8, 145}
+
+type MsgType byte
+
+const (
+	MsgHandshakeTy  = 0x00
+	MsgDiscTy       = 0x01
+	MsgPingTy       = 0x02
+	MsgPongTy       = 0x03
+	MsgGetPeersTy   = 0x10
+	MsgPeersTy      = 0x11
+	MsgTxTy         = 0x12
+	MsgBlockTy      = 0x13
+	MsgGetChainTy   = 0x14
+	MsgNotInChainTy = 0x15
+
+	MsgTalkTy = 0xff
+)
+
+var msgTypeToString = map[MsgType]string{
+	MsgHandshakeTy:  "Handshake",
+	MsgDiscTy:       "Disconnect",
+	MsgPingTy:       "Ping",
+	MsgPongTy:       "Pong",
+	MsgGetPeersTy:   "Get peers",
+	MsgPeersTy:      "Peers",
+	MsgTxTy:         "Transactions",
+	MsgBlockTy:      "Blocks",
+	MsgGetChainTy:   "Get chain",
+	MsgNotInChainTy: "Not in chain",
+}
+
+func (mt MsgType) String() string {
+	return msgTypeToString[mt]
+}
+
+type Msg struct {
+	Type MsgType // Specifies how the encoded data should be interpreted
+	//Data []byte
+	Data *ethutil.Value
+}
+
+func NewMessage(msgType MsgType, data interface{}) *Msg {
+	return &Msg{
+		Type: msgType,
+		Data: ethutil.NewValue(data),
+	}
+}
+
+func ReadMessage(data []byte) (msg *Msg, remaining []byte, done bool, err error) {
+	if len(data) == 0 {
+		return nil, nil, true, nil
+	}
+
+	if len(data) <= 8 {
+		return nil, remaining, false, errors.New("Invalid message")
+	}
+
+	// Check if the received 4 first bytes are the magic token
+	if bytes.Compare(MagicToken, data[:4]) != 0 {
+		return nil, nil, false, fmt.Errorf("MagicToken mismatch. Received %v", data[:4])
+	}
+
+	messageLength := ethutil.BytesToNumber(data[4:8])
+	remaining = data[8+messageLength:]
+	if int(messageLength) > len(data[8:]) {
+		return nil, nil, false, fmt.Errorf("message length %d, expected %d", len(data[8:]), messageLength)
+	}
+
+	message := data[8 : 8+messageLength]
+	decoder := ethutil.NewValueFromBytes(message)
+	// Type of message
+	t := decoder.Get(0).Uint()
+	// Actual data
+	d := decoder.SliceFrom(1)
+
+	msg = &Msg{
+		Type: MsgType(t),
+		Data: d,
+	}
+
+	return
+}
+
+func bufferedRead(conn net.Conn) ([]byte, error) {
+	return nil, nil
+}
+
+// The basic message reader waits for data on the given connection, decoding
+// and doing a few sanity checks such as if there's a data type and
+// unmarhals the given data
+func ReadMessages(conn net.Conn) (msgs []*Msg, err error) {
+	// The recovering function in case anything goes horribly wrong
+	defer func() {
+		if r := recover(); r != nil {
+			err = fmt.Errorf("ethwire.ReadMessage error: %v", r)
+		}
+	}()
+
+	// Buff for writing network message to
+	//buff := make([]byte, 1440)
+	var buff []byte
+	var totalBytes int
+	for {
+		// Give buffering some time
+		conn.SetReadDeadline(time.Now().Add(20 * time.Millisecond))
+		// Create a new temporarily buffer
+		b := make([]byte, 1440)
+		// Wait for a message from this peer
+		n, _ := conn.Read(b)
+		if err != nil && n == 0 {
+			if err.Error() != "EOF" {
+				fmt.Println("err now", err)
+				return nil, err
+			} else {
+				fmt.Println("IOF NOW")
+				break
+			}
+
+			// Messages can't be empty
+		} else if n == 0 {
+			break
+		}
+
+		buff = append(buff, b[:n]...)
+		totalBytes += n
+	}
+
+	// Reslice buffer
+	buff = buff[:totalBytes]
+	msg, remaining, done, err := ReadMessage(buff)
+	for ; done != true; msg, remaining, done, err = ReadMessage(remaining) {
+		//log.Println("rx", msg)
+
+		if msg != nil {
+			msgs = append(msgs, msg)
+		}
+	}
+
+	return
+}
+
+// The basic message writer takes care of writing data over the given
+// connection and does some basic error checking
+func WriteMessage(conn net.Conn, msg *Msg) error {
+	var pack []byte
+
+	// Encode the type and the (RLP encoded) data for sending over the wire
+	encoded := ethutil.NewValue(append([]interface{}{byte(msg.Type)}, msg.Data.Slice()...)).Encode()
+	payloadLength := ethutil.NumberToBytes(uint32(len(encoded)), 32)
+
+	// Write magic token and payload length (first 8 bytes)
+	pack = append(MagicToken, payloadLength...)
+	pack = append(pack, encoded...)
+	//fmt.Printf("payload %v (%v) %q\n", msg.Type, conn.RemoteAddr(), encoded)
+
+	// Write to the connection
+	_, err := conn.Write(pack)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}