// readMessage reads the next bitcoin message from the peer with logging.
func (p *peer) readMessage() (msg btcwire.Message, buf []byte, err error) {
msg, buf, err = btcwire.ReadMessage(p.conn, p.protocolVersion, p.btcnet)
if err != nil {
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: Received %v%s from %s",
msg.Command(), summary, p.addr)
}))
log.Tracef("%v", newLogClosure(func() string {
return "PEER: " + spew.Sdump(msg)
}))
log.Tracef("%v", newLogClosure(func() string {
return "PEER: " + spew.Sdump(buf)
}))
return
}
// Creates the reading and writing interfaces used to send and recieve messages
// from a Bitcoin peer. inSetup indicates the verbosity of the failure mode.
func composeConnOuts(params connParams) (func() btcwire.Message, func(btcwire.Message)) {
conn := params.conn
logger := params.logger
failmsg := "The Bitcoin server has reached its max peers and does not want to talk"
read := func() btcwire.Message {
msg, _, err := btcwire.ReadMessage(conn, params.pver, params.btcnet)
// a Bitcoin node will typically send a TCP RST if it doesn't want to talk
if params.insetup && err != nil {
logger.Printf(failmsg)
}
if err != nil {
logger.Fatal(err)
}
return msg
}
write := func(msg btcwire.Message) {
err := btcwire.WriteMessage(conn, msg, params.pver, params.btcnet)
if params.insetup && err != nil {
logger.Printf(failmsg)
}
if err != nil {
logger.Fatal(err)
}
}
return read, write
}
func (peer *Peer) InHandler() {
for {
msg, _, err := btcwire.ReadMessage(peer.conn, peer.version, peer.btcnet)
if err != nil {
fmt.Println("Error %v", err)
continue
}
switch msg := msg.(type) {
case *btcwire.MsgVerAck:
// Do nothing
fmt.Println("Version ackknowledged")
default:
fmt.Printf("Received unhandled message of type %v\n", msg.Command())
}
}
}
// readMessage reads the next bitcoin message from the peer with logging.
func (p *peer) readMessage() (msg btcwire.Message, buf []byte, err error) {
msg, buf, err = btcwire.ReadMessage(p.conn, p.protocolVersion, p.btcnet)
if err != nil {
return
}
log.Debugf("[PEER] Received command [%v] from %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] " + spew.Sdump(msg)
}))
log.Tracef("%v", newLogClosure(func() string {
return "[PEER] " + spew.Sdump(buf)
}))
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)
}
}
}
}
// TestMessage tests the Read/WriteMessage API.
func TestMessage(t *testing.T) {
pver := btcwire.ProtocolVersion
// Create the various types of messages to test.
// MsgVersion.
addrYou := &net.TCPAddr{IP: net.ParseIP("192.168.0.1"), Port: 8333}
you, err := btcwire.NewNetAddress(addrYou, btcwire.SFNodeNetwork)
if err != nil {
t.Errorf("NewNetAddress: %v", err)
}
you.Timestamp = time.Time{} // Version message has zero value timestamp.
addrMe := &net.TCPAddr{IP: net.ParseIP("127.0.0.1"), Port: 8333}
me, err := btcwire.NewNetAddress(addrMe, btcwire.SFNodeNetwork)
if err != nil {
t.Errorf("NewNetAddress: %v", err)
}
me.Timestamp = time.Time{} // Version message has zero value timestamp.
msgVersion := btcwire.NewMsgVersion(me, you, 123123, "/test:0.0.1/", 0)
msgVerack := btcwire.NewMsgVerAck()
msgGetAddr := btcwire.NewMsgGetAddr()
msgAddr := btcwire.NewMsgAddr()
msgGetBlocks := btcwire.NewMsgGetBlocks(&btcwire.ShaHash{})
msgBlock := &blockOne
msgInv := btcwire.NewMsgInv()
msgGetData := btcwire.NewMsgGetData()
msgNotFound := btcwire.NewMsgNotFound()
msgTx := btcwire.NewMsgTx()
msgPing := btcwire.NewMsgPing(123123)
msgPong := btcwire.NewMsgPong(123123)
msgGetHeaders := btcwire.NewMsgGetHeaders()
msgHeaders := btcwire.NewMsgHeaders()
msgAlert := btcwire.NewMsgAlert("payload", "signature")
msgMemPool := btcwire.NewMsgMemPool()
tests := []struct {
in btcwire.Message // Value to encode
out btcwire.Message // Expected decoded value
pver uint32 // Protocol version for wire encoding
btcnet btcwire.BitcoinNet // Network to use for wire encoding
}{
{msgVersion, msgVersion, pver, btcwire.MainNet},
{msgVerack, msgVerack, pver, btcwire.MainNet},
{msgGetAddr, msgGetAddr, pver, btcwire.MainNet},
{msgAddr, msgAddr, pver, btcwire.MainNet},
{msgGetBlocks, msgGetBlocks, pver, btcwire.MainNet},
{msgBlock, msgBlock, pver, btcwire.MainNet},
{msgInv, msgInv, pver, btcwire.MainNet},
{msgGetData, msgGetData, pver, btcwire.MainNet},
{msgNotFound, msgNotFound, pver, btcwire.MainNet},
{msgTx, msgTx, pver, btcwire.MainNet},
{msgPing, msgPing, pver, btcwire.MainNet},
{msgPong, msgPong, pver, btcwire.MainNet},
{msgGetHeaders, msgGetHeaders, pver, btcwire.MainNet},
{msgHeaders, msgHeaders, pver, btcwire.MainNet},
{msgAlert, msgAlert, pver, btcwire.MainNet},
{msgMemPool, msgMemPool, pver, btcwire.MainNet},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Encode to wire format.
var buf bytes.Buffer
err := btcwire.WriteMessage(&buf, test.in, test.pver, test.btcnet)
if err != nil {
t.Errorf("WriteMessage #%d error %v", i, err)
continue
}
// Decode from wire format.
rbuf := bytes.NewBuffer(buf.Bytes())
msg, _, err := btcwire.ReadMessage(rbuf, test.pver, test.btcnet)
if err != nil {
t.Errorf("ReadMessage #%d error %v, msg %v", i, err,
spew.Sdump(msg))
continue
}
if !reflect.DeepEqual(msg, test.out) {
t.Errorf("ReadMessage #%d\n got: %v want: %v", i,
spew.Sdump(msg), spew.Sdump(test.out))
continue
}
}
}
// TestReadMessageWireErrors performs negative tests against wire decoding into
// concrete messages to confirm error paths work correctly.
func TestReadMessageWireErrors(t *testing.T) {
pver := btcwire.ProtocolVersion
btcnet := btcwire.MainNet
// Ensure message errors are as expected with no function specified.
wantErr := "something bad happened"
testErr := btcwire.MessageError{Description: wantErr}
if testErr.Error() != wantErr {
t.Errorf("MessageError: wrong error - got %v, want %v",
testErr.Error(), wantErr)
}
// Ensure message errors are as expected with a function specified.
wantFunc := "foo"
testErr = btcwire.MessageError{Func: wantFunc, Description: wantErr}
if testErr.Error() != wantFunc+": "+wantErr {
t.Errorf("MessageError: wrong error - got %v, want %v",
testErr.Error(), wantErr)
}
// Wire encoded bytes for main and testnet3 networks magic identifiers.
testNet3Bytes := makeHeader(btcwire.TestNet3, "", 0, 0)
// Wire encoded bytes for a message that exceeds max overall message
// length.
mpl := btcwire.MaxMessagePayload
exceedMaxPayloadBytes := makeHeader(btcnet, "getaddr", mpl+1, 0)
// Wire encoded bytes for a command which is invalid utf-8.
badCommandBytes := makeHeader(btcnet, "bogus", 0, 0)
badCommandBytes[4] = 0x81
// Wire encoded bytes for a command which is valid, but not supported.
unsupportedCommandBytes := makeHeader(btcnet, "bogus", 0, 0)
// Wire encoded bytes for a message which exceeds the max payload for
// a specific message type.
exceedTypePayloadBytes := makeHeader(btcnet, "getaddr", 1, 0)
// Wire encoded bytes for a message which does not deliver the full
// payload according to the header length.
shortPayloadBytes := makeHeader(btcnet, "version", 115, 0)
// Wire encoded bytes for a message with a bad checksum.
badChecksumBytes := makeHeader(btcnet, "version", 2, 0xbeef)
badChecksumBytes = append(badChecksumBytes, []byte{0x0, 0x0}...)
// Wire encoded bytes for a message which has a valid header, but is
// the wrong format. An addr starts with a varint of the number of
// contained in the message. Claim there is two, but don't provide
// them. At the same time, forge the header fields so the message is
// otherwise accurate.
badMessageBytes := makeHeader(btcnet, "addr", 1, 0xeaadc31c)
badMessageBytes = append(badMessageBytes, 0x2)
// Wire encoded bytes for a message which the header claims has 15k
// bytes of data to discard.
discardBytes := makeHeader(btcnet, "bogus", 15*1024, 0)
tests := []struct {
buf []byte // Wire encoding
pver uint32 // Protocol version for wire encoding
btcnet btcwire.BitcoinNet // Bitcoin network for wire encoding
max int // Max size of fixed buffer to induce errors
readErr error // Expected read error
}{
// Latest protocol version with intentional read errors.
// Short header.
{
[]byte{},
pver,
btcnet,
0,
io.EOF,
},
// Wrong network. Want MainNet, but giving TestNet3.
{
testNet3Bytes,
pver,
btcnet,
len(testNet3Bytes),
&btcwire.MessageError{},
},
// Exceed max overall message payload length.
{
exceedMaxPayloadBytes,
pver,
btcnet,
len(exceedMaxPayloadBytes),
&btcwire.MessageError{},
},
// Invalid UTF-8 command.
{
badCommandBytes,
pver,
btcnet,
len(badCommandBytes),
&btcwire.MessageError{},
},
// Valid, but unsupported command.
{
unsupportedCommandBytes,
pver,
btcnet,
len(unsupportedCommandBytes),
&btcwire.MessageError{},
},
// Exceed max allowed payload for a message of a specific type.
{
exceedTypePayloadBytes,
pver,
btcnet,
len(exceedTypePayloadBytes),
&btcwire.MessageError{},
},
// Message with a payload shorter than the header indicates.
{
shortPayloadBytes,
pver,
btcnet,
len(shortPayloadBytes),
io.EOF,
},
// Message with a bad checksum.
{
badChecksumBytes,
pver,
btcnet,
len(badChecksumBytes),
&btcwire.MessageError{},
},
// Message with a valid header, but wrong format.
{
badMessageBytes,
pver,
btcnet,
len(badMessageBytes),
io.EOF,
},
// 15k bytes of data to discard.
{
discardBytes,
pver,
btcnet,
len(discardBytes),
&btcwire.MessageError{},
},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Decode from wire format.
r := newFixedReader(test.max, test.buf)
_, _, err := btcwire.ReadMessage(r, test.pver, test.btcnet)
if reflect.TypeOf(err) != reflect.TypeOf(test.readErr) {
t.Errorf("ReadMessage #%d wrong error got: %v <%T>, "+
"want: %T", i, err, err, test.readErr)
continue
}
// For errors which are not of type btcwire.MessageError, check
// them for equality.
if _, ok := err.(*btcwire.MessageError); !ok {
if err != test.readErr {
t.Errorf("ReadMessage #%d wrong error got: %v <%T>, "+
"want: %v <%T>", i, err, err,
test.readErr, test.readErr)
continue
}
}
}
}