more srv stuff and packet inspetor

cmd/strom/main.go

@@ -9,6 +9,7 @@ import (
 	"slices"
 
 	"github.com/admin-else/strom/cmd/strom/offline_uuid"
+	"github.com/admin-else/strom/cmd/strom/packet_inspector"
 	"github.com/admin-else/strom/cmd/strom/print_nbt"
 	"github.com/admin-else/strom/cmd/strom/status"
 )
@@ -20,6 +21,7 @@ var subcommands = map[string]func(args []string) error{
 	"offline-uuid": offline_uuid.Run,
 	"print-nbt":    print_nbt.Run,
 	"status":       status.Run,
+	"packet-spy":   packet_inspector.Run,
 }
 
 func Help(args []string) (err error) {

cmd/strom/packet_inspector/main.go

@@ -0,0 +1,118 @@
+package packet_inspector
+
+import (
+	"flag"
+	"log/slog"
+
+	"github.com/admin-else/strom/api"
+	"github.com/admin-else/strom/client"
+	"github.com/admin-else/strom/event"
+	"github.com/admin-else/strom/nbt"
+	"github.com/admin-else/strom/proto"
+	"github.com/admin-else/strom/proto_base"
+	"github.com/admin-else/strom/proto_generated/v1_21_11"
+	"github.com/admin-else/strom/server"
+	"github.com/admin-else/strom/text"
+)
+
+var Cmd = flag.NewFlagSet("packet-inspector", flag.ContinueOnError)
+
+var OfflineNameFlag = Cmd.String("name", "packet_inspector", "offline player name")
+var Token = Cmd.String("token", "", "token to use")
+
+var TargetAddr = Cmd.String("addr", "127.0.0.1:25565", "address to connect to")
+var ListenAddr = Cmd.String("listen", "127.0.0.1:25566", "address to listen on")
+
+type Proxy struct {
+	Client, Servee *proto.Conn
+	Data           nbt.Tag
+}
+
+func (p *Proxy) Start() (err error) {
+	p.Client.RegisterCritical(p.OnAnything)
+	p.Servee.RegisterCritical(p.OnAnything)
+
+	p.Servee.RegisterCriticalUntilLatest(p.OnFinishConfiguration)
+
+	errChan := make(chan error)
+	go func() {
+		errChan <- p.Client.StartConn()
+	}()
+	go func() {
+		errChan <- p.Servee.StartConn()
+	}()
+	err = <-errChan
+	return
+}
+
+func (p *Proxy) OnAnything(e event.Anything) (err error) {
+	packet, ok := e.Val.(proto_base.EncodeDecodeAble)
+	if !ok {
+		return
+	}
+	packetInfo, ok := proto.LookupPacketInfoByType(packet)
+	if !ok {
+		return
+	}
+	switch packetInfo.Direction {
+	case proto_base.ToServer:
+		err = p.Client.Send(packet)
+	case proto_base.ToClient:
+		err = p.Servee.Send(packet)
+	}
+	return
+}
+
+func (p *Proxy) OnFinishConfiguration(packet *v1_21_11.ConfigurationToServerPacketFinishConfiguration) (err error) {
+	err = p.Client.Send(packet)
+	if err != nil {
+		return
+	}
+	p.Servee.SetState(proto_base.Play)
+	p.Client.SetState(proto_base.Play)
+	err = event.DontForwardErr
+	return
+}
+
+var StatusResponse = server.StatusResponse{
+	Version: server.StatusResponseVersion{
+		Name:     text.Pretty("STROM"),
+		Protocol: 772,
+	},
+	Players:            server.StatusResponsePlayers{},
+	Description:        text.Pretty("Packet spy forwards to " + *TargetAddr),
+	Favicon:            "",
+	EnforcesSecureChat: false,
+}
+
+func Run(args []string) (err error) {
+	err = Cmd.Parse(args)
+	if err != nil {
+		return
+	}
+	slog.SetLogLoggerLevel(slog.LevelDebug)
+	slog.Info("Starting packet inspector", "listen", *ListenAddr)
+	err = server.StartServerWithOnConn(*ListenAddr, func(serveeConn *proto.Conn) (err error) {
+		p := &Proxy{Servee: serveeConn, Client: nil}
+		var acc = api.NewOfflineAccount(*OfflineNameFlag)
+		if *Token != "" {
+			acc, err = api.NewAccountFromYGG(*Token)
+			if err != nil {
+				return
+			}
+		}
+		_, err = server.ServeLogin(serveeConn, server.WithOtherAccount(acc), server.WithStatus(StatusResponse))
+		if err != nil {
+			return
+		}
+		c, err := client.Login(*TargetAddr, acc)
+		if err != nil {
+			return
+		}
+		defer c.Close()
+		p.Client = c
+		err = p.Start()
+		return
+	})
+	return
+}