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package main
import (
"github.com/ethereum/ethutil-go"
"github.com/ethereum/ethwire-go"
"log"
"net"
"sync/atomic"
"time"
)
const (
// The size of the output buffer for writing messages
outputBufferSize = 50
)
type Peer struct {
// Server interface
server *Server
// Net connection
conn net.Conn
// Output queue which is used to communicate and handle messages
outputQueue chan *ethwire.InOutMsg
// Quit channel
quit chan bool
// Determines whether it's an inbound or outbound peer
inbound bool
// Flag for checking the peer's connectivity state
connected int32
disconnect int32
// Last known message send
lastSend time.Time
// Indicated whether a verack has been send or not
// This flag is used by writeMessage to check if messages are allowed
// to be send or not. If no version is known all messages are ignored.
versionKnown bool
}
func NewPeer(conn net.Conn, server *Server, inbound bool) *Peer {
return &Peer{
outputQueue: make(chan *ethwire.InOutMsg, outputBufferSize),
quit: make(chan bool),
server: server,
conn: conn,
inbound: inbound,
disconnect: 0,
connected: 1,
}
}
func NewOutboundPeer(addr string, server *Server) *Peer {
p := &Peer{
outputQueue: make(chan *ethwire.InOutMsg, outputBufferSize),
quit: make(chan bool),
server: server,
inbound: false,
connected: 0,
disconnect: 1,
}
// Set up the connection in another goroutine so we don't block the main thread
go func() {
conn, err := net.Dial("tcp", addr)
if err != nil {
p.Stop()
}
p.conn = conn
// Atomically set the connection state
atomic.StoreInt32(&p.connected, 1)
atomic.StoreInt32(&p.disconnect, 0)
log.Println("Connected to peer ::", conn.RemoteAddr())
p.Start()
}()
return p
}
// Outputs any RLP encoded data to the peer
func (p *Peer) QueueMessage(msg *ethwire.InOutMsg) {
p.outputQueue <- msg
}
func (p *Peer) writeMessage(msg *ethwire.InOutMsg) {
// Ignore the write if we're not connected
if atomic.LoadInt32(&p.connected) != 1 {
return
}
if !p.versionKnown {
switch msg.MsgType {
case "verack": // Ok
default: // Anything but ack is allowed
return
}
}
err := ethwire.WriteMessage(p.conn, msg)
if err != nil {
log.Println("Can't send message:", err)
// Stop the client if there was an error writing to it
p.Stop()
return
}
}
// Outbound message handler. Outbound messages are handled here
func (p *Peer) HandleOutbound() {
out:
for {
select {
// Main message queue. All outbound messages are processed through here
case msg := <-p.outputQueue:
p.writeMessage(msg)
p.lastSend = time.Now()
// Break out of the for loop if a quit message is posted
case <-p.quit:
break out
}
}
clean:
// This loop is for draining the output queue and anybody waiting for us
for {
select {
case <- p.outputQueue:
// TODO
default:
break clean
}
}
}
// Inbound handler. Inbound messages are received here and passed to the appropriate methods
func (p *Peer) HandleInbound() {
out:
for atomic.LoadInt32(&p.disconnect) == 0 {
// Wait for a message from the peer
msg, err := ethwire.ReadMessage(p.conn)
if err != nil {
log.Println(err)
break out
}
if Debug {
log.Printf("Received %s\n", msg.MsgType)
}
// TODO Hash data and check if for existence (= ignore)
switch msg.MsgType {
case "verack":
// Version message
p.handleVersionAck(msg)
case "block":
err := p.server.blockManager.ProcessBlock(ethutil.NewBlock(msg.Data))
if err != nil {
log.Println(err)
}
case "blockmine":
d, _ := ethutil.Decode(msg.Data, 0)
log.Printf("block mined %s\n", d)
}
}
p.Stop()
}
func (p *Peer) Start() {
if !p.inbound {
err := p.pushVersionAck()
if err != nil {
log.Printf("Peer can't send outbound version ack", err)
p.Stop()
}
}
// Run the outbound handler in a new goroutine
go p.HandleOutbound()
// Run the inbound handler in a new goroutine
go p.HandleInbound()
}
func (p *Peer) Stop() {
if atomic.AddInt32(&p.disconnect, 1) != 1 {
return
}
close(p.quit)
if atomic.LoadInt32(&p.connected) != 0 {
p.conn.Close()
}
log.Println("Peer shutdown")
}
func (p *Peer) pushVersionAck() error {
msg := ethwire.NewMessage("verack", p.server.Nonce, []byte("01"))
p.QueueMessage(msg)
return nil
}
func (p *Peer) handleVersionAck(msg *ethwire.InOutMsg) {
// Detect self connect
if msg.Nonce == p.server.Nonce {
log.Println("Peer connected to self, disconnecting")
p.Stop()
return
}
p.versionKnown = true
// If this is an inbound connection send an ack back
if p.inbound {
err := p.pushVersionAck()
if err != nil {
log.Println("Peer can't send ack back")
p.Stop()
}
}
}
|
