/
main.go
473 lines (422 loc) · 10.6 KB
/
main.go
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package main
import (
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"log"
"os"
"runtime/debug"
"strings"
"sync"
"time"
"github.com/df-mc/atomic"
"github.com/fsnotify/fsnotify"
_ "github.com/icza/bitio"
"github.com/pelletier/go-toml/v2"
"github.com/sandertv/gophertunnel/minecraft"
"github.com/sandertv/gophertunnel/minecraft/auth"
"github.com/sandertv/gophertunnel/minecraft/protocol/packet"
"github.com/sirupsen/logrus"
"golang.org/x/oauth2"
)
const (
packetTypeReferencePackage = "github.com/sandertv/gophertunnel"
packetTypeReferenceLinkTemplate = "(Look at https://pkg.go.dev/" + packetTypeReferencePackage + "@%s/minecraft/protocol/packet#pkg-index)"
)
var (
packetTypeReferenceLink string
showPacketType []string
showPacketTypeMu sync.RWMutex
)
type authMessageWriter chan *oauth2.Token
func (authMessageWriter) Write(message []byte) (int, error) {
fmt.Println(string(message))
fmt.Println("Press enter to skip this step, if the target server does not require authentication (online mode = off).")
return 0, nil
}
// The following program implements a proxy that forwards players from one local address to a remote address.
func main() {
findPacketTypeReferencePackageVersion()
logrus.SetFormatter(&logrus.TextFormatter{
FullTimestamp: true,
})
logrus.SetLevel(logrus.TraceLevel)
const configPath = "config.toml"
c := readConfig(configPath)
writer := make(authMessageWriter, 1)
var src oauth2.TokenSource
skip := make(chan struct{}, 1)
go func() {
if token, err := auth.RequestLiveTokenWriter(writer); err != nil {
logrus.Errorf("Authentication failed: %s", err)
} else {
src = auth.RefreshTokenSource(token)
}
if skip != nil {
close(skip)
skip = nil
}
}()
go func() {
fmt.Scanln()
if skip != nil {
close(skip)
skip = nil
}
}()
<-skip
p, err := minecraft.NewForeignStatusProvider(c.Connection.RemoteAddress)
if err != nil {
panic(err)
}
listener, err := minecraft.ListenConfig{
StatusProvider: p,
}.Listen("raknet", c.Connection.LocalAddress)
if err != nil {
panic(err)
}
defer listener.Close()
onReload := make([]func(c config), 3)
onReload[0] = func(c config) {
showPacketTypeMu.Lock()
defer showPacketTypeMu.Unlock()
showPacketType = c.PacketLogger.ShowPacketType
}
/*
0 = receive.
1 = send.
*/
loggerContexts := []loggerContext{
{
Prefix: "[Receive] ",
},
{
Prefix: "[Send] ",
},
}
for index, context := range loggerContexts {
newDelayChannel := make(chan time.Duration)
context.CountHiddenDelayChannel = newDelayChannel
context.CountHiddenAtomicPointer = &atomic.Int32{}
loggerContexts[index] = context
var f func(c config)
switch index {
default:
f = func(config) {
logrus.Debugf("Config update does not affect logger %s.", context.Prefix)
}
case 0:
f = func(c config) {
newDelayChannel <- c.PacketLogger.ReportHiddenPacketCountDelay.Receive
}
case 1:
f = func(c config) {
newDelayChannel <- c.PacketLogger.ReportHiddenPacketCountDelay.Send
}
}
onReload[index+1] = f
go startReportingHiddenPacketCount(context)
}
if c.Reload.ConfigAutoReload {
logrus.Info("Creating file watcher...")
watcher, err := fsnotify.NewWatcher()
if err != nil {
logrus.Error(err)
}
defer watcher.Close()
logrus.Infof("Adding %s to file watcher...", configPath)
if err := watcher.Add(configPath); err != nil {
logrus.Error(err)
} else {
go configAutoReload(configPath, watcher, onReload)
}
}
// The original config.
for _, f := range onReload {
go f(c)
}
if src != nil {
logrus.Info("Starting local proxy with authentication...")
} else {
logrus.Warn("Starting local proxy WITHOUT authentication...")
}
for {
conn, err := listener.Accept()
if err != nil {
panic(err)
}
logrus.Info("New connection established.")
// Address will not be affected by config reload.
go handleConn(conn.(*minecraft.Conn), listener, c.Connection.RemoteAddress, src, loggerContexts)
}
}
// configAutoReload runs each onReload function on its own goroutine.
func configAutoReload(configPath string, watcher *fsnotify.Watcher, onReload []func(c config)) {
for {
select {
case event, ok := <-watcher.Events:
if !ok {
return
}
c := config{}
if event.Op&fsnotify.Write != fsnotify.Write || readConfigNoWrite(configPath, &c) != nil {
continue
}
logrus.Debug("Reloaded config.")
if !c.Reload.ConfigAutoReload {
logrus.Info("Config auto-reload will until this app instance ends from now on.")
return
}
for _, f := range onReload {
go f(c)
}
case err, ok := <-watcher.Errors:
if !ok {
return
}
logrus.Warnf("Failed to reload config: %s", err)
}
}
}
type loggerContext struct {
Prefix string
CountHiddenDelayChannel <-chan time.Duration
CountHiddenAtomicPointer *atomic.Int32
}
// handleConn handles a new incoming minecraft.Conn from the minecraft.Listener passed.
func handleConn(conn *minecraft.Conn, listener *minecraft.Listener, remoteAddress string, src oauth2.TokenSource, loggerContexts []loggerContext) {
serverConn, err := minecraft.Dialer{
TokenSource: src,
ClientData: conn.ClientData(),
}.Dial("raknet", remoteAddress)
if err != nil {
panic(err)
}
var g sync.WaitGroup
g.Add(2)
go func() {
if err := conn.StartGame(serverConn.GameData()); err != nil {
panic(err)
}
g.Done()
}()
go func() {
if err := serverConn.DoSpawn(); err != nil {
panic(err)
}
g.Done()
}()
g.Wait()
go func() {
defer logrus.Info("Terminated one connection.")
defer listener.Disconnect(conn, "connection lost")
defer serverConn.Close()
for {
pk, err := conn.ReadPacket()
if err != nil {
return
}
context := loggerContexts[1]
pkText, err := context.PacketToLog(pk)
if pkText != "" {
text := context.Prefix + pkText
if err == nil {
logrus.Info(text)
} else {
logrus.Error(text)
}
}
if err := serverConn.WritePacket(pk); err != nil {
if disconnect, ok := errors.Unwrap(err).(minecraft.DisconnectError); ok {
_ = listener.Disconnect(conn, disconnect.Error())
}
return
}
}
}()
go func() {
defer serverConn.Close()
defer listener.Disconnect(conn, "connection lost")
for {
pk, err := serverConn.ReadPacket()
if err != nil {
if disconnect, ok := errors.Unwrap(err).(minecraft.DisconnectError); ok {
_ = listener.Disconnect(conn, disconnect.Error())
}
return
}
context := loggerContexts[0]
pkText, err := context.PacketToLog(pk)
if pkText != "" {
text := context.Prefix + pkText
if err == nil {
logrus.Info(text)
} else {
logrus.Error(text)
}
}
if err := conn.WritePacket(pk); err != nil {
return
}
}
}()
}
type config struct {
Connection struct {
LocalAddress string
RemoteAddress string
}
PacketLogger struct {
ShowPacketType []string
ReportHiddenPacketCountDelay struct {
Receive, Send time.Duration
}
}
Reload struct {
ConfigAutoReload bool
}
}
func readConfig(configPath string) config {
c := config{}
if _, err := os.Stat(configPath); os.IsNotExist(err) {
f, err := os.Create(configPath)
if err != nil {
log.Fatalf("error creating config: %v", err)
}
// Default config:
c.PacketLogger.ShowPacketType = []string{
"ActorEvent",
"ActorPickRequest",
packetTypeReferenceLink,
}
const delay = time.Second * 5
c.PacketLogger.ReportHiddenPacketCountDelay = struct {
Receive, Send time.Duration
}{delay, delay}
data, err := toml.Marshal(c)
if err != nil {
log.Fatalf("error encoding default config: %v", err)
}
if _, err := f.Write(data); err != nil {
log.Fatalf("error writing encoded default config: %v", err)
}
_ = f.Close()
}
if readConfigNoWrite(configPath, &c) != nil {
logrus.Fatal("Please come back with a fixed config.")
}
// Fallback config:
if c.Connection.LocalAddress == "" {
c.Connection.LocalAddress = "0.0.0.0:19132"
}
if len(c.PacketLogger.ShowPacketType) == 0 {
c.PacketLogger.ShowPacketType = []string{
packetTypeReferenceLink,
}
}
data, _ := toml.Marshal(c)
if err := ioutil.WriteFile(configPath, data, 0644); err != nil {
log.Fatalf("error writing config file: %v", err)
}
return c
}
func readConfigNoWrite(configPath string, c *config) error {
data, err := ioutil.ReadFile(configPath)
if err != nil {
logrus.Errorf("error reading config: %v", err)
}
if err := toml.Unmarshal(data, c); err != nil {
logrus.Errorf("error decoding config: %v", err)
return err
}
return nil
}
func (context loggerContext) PacketToLog(pk packet.Packet) (text string, err error) {
packetTypeName := fmt.Sprintf("%T", pk)
for _, ShowPacketType := range getShowPacketType() {
if strings.Contains(packetTypeName, ShowPacketType) {
const (
prefix = "=========="
suffix = " PACKET " + prefix
)
text += packetTypeName + "\n"
if pkMarshal, err2 := json.MarshalIndent(pk, "", " "); err2 != nil {
err = err2
text += err.Error()
} else {
text += prefix + "BEGIN " + suffix + "\n"
text += string(pkMarshal)
text += prefix + "END " + suffix
}
return
}
}
context.CountHiddenAtomicPointer.Add(1)
return
}
// findPacketTypeReferencePackageVersion generates a pkg.go.dev URL for the reference of packet type.
// It gets the version of one specified library (Gophertunnel) that was shipped in the current build.
// Generated URL will be output to packetTypeReferenceLink eventually.
// If it fails to read the build info, the "latest" version will be used.
func findPacketTypeReferencePackageVersion() {
if bi, ok := debug.ReadBuildInfo(); !ok {
logrus.Warn("Failed to read build info")
return
} else {
for _, dep := range bi.Deps {
if dep.Path != packetTypeReferencePackage {
continue
}
packetTypeReferenceLink = fmt.Sprintf(packetTypeReferenceLinkTemplate, dep.Version)
return
}
}
packetTypeReferenceLink = fmt.Sprintf(packetTypeReferenceLinkTemplate, "latest")
}
func startReportingHiddenPacketCount(context loggerContext) {
const template = "%d hidden packets."
var (
delay time.Duration
t *time.Ticker
)
defer func() {
if t != nil {
t.Stop()
}
}()
for {
for delay <= 0 {
delay = <-context.CountHiddenDelayChannel
}
if t == nil {
t = time.NewTicker(delay)
} else {
t.Reset(delay)
}
counter := context.CountHiddenAtomicPointer
count := counter.Load()
counter.Store(0)
if count > 0 {
logrus.Infof(
context.Prefix+template,
count,
)
}
select {
case <-t.C:
case delay = <-context.CountHiddenDelayChannel:
if delay <= 0 {
t.Stop()
t = nil
} else {
t.Reset(delay)
}
}
}
}
func getShowPacketType() []string {
showPacketTypeMu.RLock()
defer showPacketTypeMu.RUnlock()
return showPacketType
}