neoneo-go/pkg/network/message.go
Roman Khimov 0ba6b2a754 network: introduce peer sending queues
Two queues for high-priority and ordinary messages. Fixes #590. These queues
are deliberately made small to avoid buffer bloat problem, there is gonna be
another queueing layer above them to compensate for that. The queues are
designed to be synchronous in enqueueing, async capabilities are to be added
layer above later.
2020-01-20 17:23:26 +03:00

272 lines
6.1 KiB
Go

package network
import (
"encoding/binary"
"errors"
"fmt"
"github.com/CityOfZion/neo-go/config"
"github.com/CityOfZion/neo-go/pkg/consensus"
"github.com/CityOfZion/neo-go/pkg/core/block"
"github.com/CityOfZion/neo-go/pkg/core/transaction"
"github.com/CityOfZion/neo-go/pkg/crypto/hash"
"github.com/CityOfZion/neo-go/pkg/io"
"github.com/CityOfZion/neo-go/pkg/network/payload"
)
const (
// The minimum size of a valid message.
minMessageSize = 24
cmdSize = 12
)
var (
errChecksumMismatch = errors.New("checksum mismatch")
)
// Message is the complete message send between nodes.
type Message struct {
// NetMode of the node that sends this message.
Magic config.NetMode
// Command is utf8 code, of which the length is 12 bytes,
// the extra part is filled with 0.
Command [cmdSize]byte
// Length of the payload.
Length uint32
// Checksum is the first 4 bytes of the value that two times SHA256
// hash of the payload.
Checksum uint32
// Payload send with the message.
Payload payload.Payload
}
// CommandType represents the type of a message command.
type CommandType string
// Valid protocol commands used to send between nodes.
const (
CMDAddr CommandType = "addr"
CMDBlock CommandType = "block"
CMDConsensus CommandType = "consensus"
CMDFilterAdd CommandType = "filteradd"
CMDFilterClear CommandType = "filterclear"
CMDFilterLoad CommandType = "filterload"
CMDGetAddr CommandType = "getaddr"
CMDGetBlocks CommandType = "getblocks"
CMDGetData CommandType = "getdata"
CMDGetHeaders CommandType = "getheaders"
CMDHeaders CommandType = "headers"
CMDInv CommandType = "inv"
CMDMempool CommandType = "mempool"
CMDMerkleBlock CommandType = "merkleblock"
CMDPing CommandType = "ping"
CMDPong CommandType = "pong"
CMDTX CommandType = "tx"
CMDUnknown CommandType = "unknown"
CMDVerack CommandType = "verack"
CMDVersion CommandType = "version"
)
// NewMessage returns a new message with the given payload.
func NewMessage(magic config.NetMode, cmd CommandType, p payload.Payload) *Message {
var (
size uint32
checksum []byte
)
if p != nil {
buf := io.NewBufBinWriter()
p.EncodeBinary(buf.BinWriter)
if buf.Err != nil {
panic(buf.Err)
}
b := buf.Bytes()
size = uint32(len(b))
checksum = hash.Checksum(b)
} else {
checksum = hash.Checksum([]byte{})
}
return &Message{
Magic: magic,
Command: cmdToByteArray(cmd),
Length: size,
Payload: p,
Checksum: binary.LittleEndian.Uint32(checksum[:4]),
}
}
// CommandType converts the 12 byte command slice to a CommandType.
func (m *Message) CommandType() CommandType {
cmd := cmdByteArrayToString(m.Command)
switch cmd {
case "addr":
return CMDAddr
case "block":
return CMDBlock
case "consensus":
return CMDConsensus
case "filteradd":
return CMDFilterAdd
case "filterclear":
return CMDFilterClear
case "filterload":
return CMDFilterLoad
case "getaddr":
return CMDGetAddr
case "getblocks":
return CMDGetBlocks
case "getdata":
return CMDGetData
case "getheaders":
return CMDGetHeaders
case "headers":
return CMDHeaders
case "inv":
return CMDInv
case "mempool":
return CMDMempool
case "merkleblock":
return CMDMerkleBlock
case "ping":
return CMDPing
case "pong":
return CMDPong
case "tx":
return CMDTX
case "verack":
return CMDVerack
case "version":
return CMDVersion
default:
return CMDUnknown
}
}
// Decode decodes a Message from the given reader.
func (m *Message) Decode(br *io.BinReader) error {
m.Magic = config.NetMode(br.ReadU32LE())
br.ReadBytes(m.Command[:])
m.Length = br.ReadU32LE()
m.Checksum = br.ReadU32LE()
if br.Err != nil {
return br.Err
}
// return if their is no payload.
if m.Length == 0 {
return nil
}
return m.decodePayload(br)
}
func (m *Message) decodePayload(br *io.BinReader) error {
buf := make([]byte, m.Length)
br.ReadBytes(buf)
if br.Err != nil {
return br.Err
}
// Compare the checksum of the payload.
if !compareChecksum(m.Checksum, buf) {
return errChecksumMismatch
}
r := io.NewBinReaderFromBuf(buf)
var p payload.Payload
switch m.CommandType() {
case CMDVersion:
p = &payload.Version{}
case CMDInv, CMDGetData:
p = &payload.Inventory{}
case CMDAddr:
p = &payload.AddressList{}
case CMDBlock:
p = &block.Block{}
case CMDConsensus:
p = &consensus.Payload{}
case CMDGetBlocks:
fallthrough
case CMDGetHeaders:
p = &payload.GetBlocks{}
case CMDHeaders:
p = &payload.Headers{}
case CMDTX:
p = &transaction.Transaction{}
case CMDMerkleBlock:
p = &payload.MerkleBlock{}
case CMDPing, CMDPong:
p = &payload.Ping{}
default:
return fmt.Errorf("can't decode command %s", cmdByteArrayToString(m.Command))
}
p.DecodeBinary(r)
if r.Err == nil || r.Err == payload.ErrTooManyHeaders {
m.Payload = p
}
return r.Err
}
// Encode encodes a Message to any given BinWriter.
func (m *Message) Encode(br *io.BinWriter) error {
br.WriteU32LE(uint32(m.Magic))
br.WriteBytes(m.Command[:])
br.WriteU32LE(m.Length)
br.WriteU32LE(m.Checksum)
if m.Payload != nil {
m.Payload.EncodeBinary(br)
}
if br.Err != nil {
return br.Err
}
return nil
}
// Bytes serializes a Message into the new allocated buffer and returns it.
func (m *Message) Bytes() ([]byte, error) {
w := io.NewBufBinWriter()
if err := m.Encode(w.BinWriter); err != nil {
return nil, err
}
if w.Err != nil {
return nil, w.Err
}
return w.Bytes(), nil
}
// convert a command (string) to a byte slice filled with 0 bytes till
// size 12.
func cmdToByteArray(cmd CommandType) [cmdSize]byte {
cmdLen := len(cmd)
if cmdLen > cmdSize {
panic("exceeded command max length of size 12")
}
// The command can have max 12 bytes, rest is filled with 0.
b := [cmdSize]byte{}
for i := 0; i < cmdLen; i++ {
b[i] = cmd[i]
}
return b
}
func cmdByteArrayToString(cmd [cmdSize]byte) string {
buf := make([]byte, 0, cmdSize)
for i := 0; i < cmdSize; i++ {
if cmd[i] != 0 {
buf = append(buf, cmd[i])
}
}
return string(buf)
}
func compareChecksum(have uint32, b []byte) bool {
sum := hash.Checksum(b)
want := binary.LittleEndian.Uint32(sum)
return have == want
}