// writeMessage sends a bitcoin Message to the peer with logging.
func (p *peer) writeMessage(msg btcwire.Message) {
// Don't do anything if we're disconnecting.
if atomic.LoadInt32(&p.disconnect) != 0 {
return
}
log.Debugf("[PEER] Sending command [%v] to %s", msg.Command(),
p.addr)
// Use closures to log expensive operations so they are only run when the
// logging level requires it.
log.Tracef("%v", newLogClosure(func() string {
return "[PEER] msg" + spew.Sdump(msg)
}))
log.Tracef("%v", newLogClosure(func() string {
var buf bytes.Buffer
err := btcwire.WriteMessage(&buf, msg, p.protocolVersion, p.btcnet)
if err != nil {
return err.Error()
}
return "[PEER] " + spew.Sdump(buf.Bytes())
}))
// Write the message to the peer.
err := btcwire.WriteMessage(p.conn, msg, p.protocolVersion, p.btcnet)
if err != nil {
p.Disconnect()
p.logError("[PEER] Can't send message: %v", err)
return
}
}
// messageToHex serializes a message to the wire protocol encoding using the
// latest protocol version and returns a hex-encoded string of the result.
func messageToHex(msg btcwire.Message) (string, error) {
var buf bytes.Buffer
err := msg.BtcEncode(&buf, btcwire.ProtocolVersion)
if err != nil {
return "", btcjson.Error{
Code: btcjson.ErrInternal.Code,
Message: err.Error(),
}
}
return hex.EncodeToString(buf.Bytes()), nil
}
// writeMessage sends a bitcoin Message to the peer with logging.
func (p *peer) writeMessage(msg btcwire.Message) {
// Don't do anything if we're disconnecting.
if atomic.LoadInt32(&p.disconnect) != 0 {
return
}
if !p.versionKnown {
switch msg.(type) {
case *btcwire.MsgVersion:
// This is OK.
default:
// We drop all messages other than version if we
// haven't done the handshake already.
return
}
}
// Use closures to log expensive operations so they are only run when
// the logging level requires it.
log.Debugf("%v", newLogClosure(func() string {
// Debug summary of message.
summary := messageSummary(msg)
if len(summary) > 0 {
summary = " (" + summary + ")"
}
return fmt.Sprintf("PEER: Sending %v%s to %s", msg.Command(),
summary, p.addr)
}))
log.Tracef("%v", newLogClosure(func() string {
return "PEER: " + spew.Sdump(msg)
}))
log.Tracef("%v", newLogClosure(func() string {
var buf bytes.Buffer
err := btcwire.WriteMessage(&buf, msg, p.protocolVersion, p.btcnet)
if err != nil {
return err.Error()
}
return "PEER: " + spew.Sdump(buf.Bytes())
}))
// Write the message to the peer.
err := btcwire.WriteMessage(p.conn, msg, p.protocolVersion, p.btcnet)
if err != nil {
p.Disconnect()
p.logError("PEER: Can't send message: %v", err)
return
}
}
// messageSummary returns a human-readable string which summarizes a message.
// Not all messages have or need a summary. This is used for debug logging.
func messageSummary(msg btcwire.Message) string {
switch msg := msg.(type) {
case *btcwire.MsgVersion:
return fmt.Sprintf("agent %s, pver %d, block %d",
msg.UserAgent, msg.ProtocolVersion, msg.LastBlock)
case *btcwire.MsgVerAck:
// No summary.
case *btcwire.MsgGetAddr:
// No summary.
case *btcwire.MsgAddr:
return fmt.Sprintf("%d addr", len(msg.AddrList))
case *btcwire.MsgPing:
// No summary - perhaps add nonce.
case *btcwire.MsgPong:
// No summary - perhaps add nonce.
case *btcwire.MsgAlert:
// No summary.
case *btcwire.MsgMemPool:
// No summary.
case *btcwire.MsgTx:
hash, _ := msg.TxSha()
return fmt.Sprintf("hash %s, %d inputs, %d outputs, lock %s",
hash, len(msg.TxIn), len(msg.TxOut),
formatLockTime(msg.LockTime))
case *btcwire.MsgBlock:
header := &msg.Header
hash, _ := msg.BlockSha()
return fmt.Sprintf("hash %s, ver %d, %d tx, %s", hash,
header.Version, len(msg.Transactions), header.Timestamp)
case *btcwire.MsgInv:
return invSummary(msg.InvList)
case *btcwire.MsgNotFound:
return invSummary(msg.InvList)
case *btcwire.MsgGetData:
return invSummary(msg.InvList)
case *btcwire.MsgGetBlocks:
return locatorSummary(msg.BlockLocatorHashes, &msg.HashStop)
case *btcwire.MsgGetHeaders:
return locatorSummary(msg.BlockLocatorHashes, &msg.HashStop)
case *btcwire.MsgHeaders:
return fmt.Sprintf("num %d", len(msg.Headers))
case *btcwire.MsgReject:
// Ensure the variable length strings don't contain any
// characters which are even remotely dangerous such as HTML
// control characters, etc. Also limit them to sane length for
// logging.
rejCommand := sanitizeString(msg.Cmd, btcwire.CommandSize)
rejReason := sanitizeString(msg.Reason, maxRejectReasonLen)
summary := fmt.Sprintf("cmd %v, code %v, reason %v", rejCommand,
msg.Code, rejReason)
if rejCommand == btcwire.CmdBlock || rejCommand == btcwire.CmdTx {
summary += fmt.Sprintf(", hash %v", msg.Hash)
}
return summary
}
// No summary for other messages.
return ""
}
func connHandler(id int, outAddrs chan<- []*btc.NetAddress, outNode chan<- Node, inAddr <-chan *btc.NetAddress) {
// A worker that deals with the connection to a single bitcoin node.
// It writes the list of nodes reported by node into out.
// It also writes a valid node into outNode.
// It reads from inAddr everytime it closes a connection
for {
addr := <-inAddr
strA := addressFmt(*addr)
threadLog := func(reported LogLevel, msg string) {
if reported <= Level {
logger.Printf("[%d] %s: %s\n", id, strA, msg)
}
}
connProtoVer := btc.ProtocolVersion
write := composeWrite(threadLog, connProtoVer)
conn, err := net.DialTimeout("tcp", strA, time.Millisecond*500)
if err != nil {
threadLog(Log, err.Error())
continue
}
threadLog(Info, "Connected")
ver_m, _ := btc.NewMsgVersionFromConn(conn, genNonce(), 0)
ver_m.AddUserAgent("btcmonitor", "0.0.1")
write(conn, ver_m)
// We are looking for successful addr messages
wins := 0
// After 10 seconds we just close the conn and handle errors
time.AfterFunc(time.Second*10, func() { conn.Close() })
MessageLoop:
for {
var resp btc.Message
resp, _, err := btc.ReadMessage(conn, connProtoVer, btcnet)
if err != nil {
threadLog(Log, err.Error())
break MessageLoop
}
threadLog(Info, resp.Command())
switch resp := resp.(type) {
case *btc.MsgVersion:
nodePVer := uint32(resp.ProtocolVersion)
if nodePVer < connProtoVer {
connProtoVer = nodePVer
write = composeWrite(threadLog, connProtoVer)
}
node := convNode(*addr, *resp)
outNode <- node
verack := btc.NewMsgVerAck()
write(conn, verack)
getAddr := btc.NewMsgGetAddr()
write(conn, getAddr)
case *btc.MsgAddr:
wins += 1
addrs := resp.AddrList
outAddrs <- addrs
if wins == 3 {
break MessageLoop
}
case *btc.MsgPing:
nonce := resp.Nonce
pong := btc.NewMsgPong(nonce)
write(conn, pong)
}
}
}
}
// messageSummary returns a human-readable string which summarizes a message.
// Not all messages have or need a summary. This is used for debug logging.
func messageSummary(msg btcwire.Message) string {
switch msg := msg.(type) {
case *btcwire.MsgVersion:
return fmt.Sprintf("agent %s, pver %d, block %d",
msg.UserAgent, msg.ProtocolVersion, msg.LastBlock)
case *btcwire.MsgVerAck:
// No summary.
case *btcwire.MsgGetAddr:
// No summary.
case *btcwire.MsgAddr:
return fmt.Sprintf("%d addr", len(msg.AddrList))
case *btcwire.MsgPing:
// No summary - perhaps add nonce.
case *btcwire.MsgPong:
// No summary - perhaps add nonce.
case *btcwire.MsgAlert:
// No summary.
case *btcwire.MsgMemPool:
// No summary.
case *btcwire.MsgTx:
hash, _ := msg.TxSha()
return fmt.Sprintf("hash %s, %d inputs, %d outputs, lock %s",
hash, len(msg.TxIn), len(msg.TxOut),
formatLockTime(msg.LockTime))
case *btcwire.MsgBlock:
header := &msg.Header
hash, _ := msg.BlockSha()
return fmt.Sprintf("hash %s, ver %d, %d tx, %s", hash,
header.Version, header.TxnCount, header.Timestamp)
case *btcwire.MsgInv:
return invSummary(msg.InvList)
case *btcwire.MsgNotFound:
return invSummary(msg.InvList)
case *btcwire.MsgGetData:
return invSummary(msg.InvList)
case *btcwire.MsgGetBlocks:
return locatorSummary(msg.BlockLocatorHashes, &msg.HashStop)
case *btcwire.MsgGetHeaders:
return locatorSummary(msg.BlockLocatorHashes, &msg.HashStop)
case *btcwire.MsgHeaders:
return fmt.Sprintf("num %d", len(msg.Headers))
}
// No summary for other messages.
return ""
}
func nodeHandler(cfg TowerCfg, txStream chan<- *TxMeta, blockStream chan<- *btcwire.MsgBlock) {
conn := setupConn(cfg.Addr, cfg.Logger)
connparams := connParams{
conn: conn,
pver: btcwire.ProtocolVersion,
btcnet: cfg.Net,
logger: cfg.Logger,
insetup: true,
}
read, write := composeConnOuts(connparams)
// Initial handshake
ver_m, _ := btcwire.NewMsgVersionFromConn(conn, genNonce(), int32(cfg.StartHeight))
ver_m.AddUserAgent("Watchtower", "0.0.0")
write(ver_m)
// Wait for responses
acked, responded := false, false
for {
var msg btcwire.Message
msg = read()
cfg.Logger.Println(msg.Command())
switch msg := msg.(type) {
case *btcwire.MsgVersion:
responded = true
ack := btcwire.NewMsgVerAck()
nodeVer := uint32(msg.ProtocolVersion)
if nodeVer < connparams.pver {
connparams.pver = nodeVer
read, write = composeConnOuts(connparams)
}
write(ack)
case *btcwire.MsgVerAck:
acked = true
}
if responded && acked {
break
}
}
// We are through the initial handshake, assume functional channel from here
// on out. If there any errors with the pipe logger.Fatal gets called.
connparams.insetup = false
read, write = composeConnOuts(connparams)
cfg.Logger.Println("Conn Negotiated")
for {
// If there are messages to send to peers send them. Otherwise, listen!
select {
case msg := <-cfg.MsgChan:
write(msg)
default:
// listen for txs + blocks then push them into the appropriatestreams
msg := read()
switch msg := msg.(type) {
case *btcwire.MsgInv:
want := btcwire.NewMsgGetData()
invVec := msg.InvList
for i := range invVec {
chunk := invVec[i]
want.AddInvVect(chunk)
}
write(want)
case *btcwire.MsgTx:
var empt []byte // evaluates to nil
meta := TxMeta{MsgTx: msg, BlockSha: empt, Time: time.Now()}
txStream <- &meta
case *btcwire.MsgBlock:
blockStream <- msg
case *btcwire.MsgPing:
pong := btcwire.NewMsgPong(msg.Nonce)
// More fun than anything...
write(pong)
}
}
}
}