Moved state around

channel.go

@@ -2,6 +2,8 @@ package pnyx
 
 import (
 	"fmt"
+	"slices"
+	"sync/atomic"
 
 	"github.com/google/uuid"
 )
@@ -9,11 +11,14 @@ import (
 type ChannelID byte
 
 const (
-  MODE_RAW ModeID = iota
+  MODE_CHANNEL ModeID = iota
+  MODE_RAW
   MODE_AUDIO
 
   AUDIO_SET_SAMPLE_RATE = iota
   AUDIO_GET_SAMPLE_RATE
+
+  CHANNEL_COMMAND_BUFFER_SIZE int = 2048
 )
 
 type ModeID uint8
@@ -21,40 +26,78 @@ type CommandID uint8
 type Permission string
 
 type Channel struct {
-  id ChannelID
-  name string
-  modes map[ModeID]Mode
-  members []*ServerSession
+  Commands chan SessionChannelCommand
+  Modes  map[ModeID]*atomic.Value
+  Members atomic.Value
+}
+
+func(channel *Channel) update_state() {
+  for true {
+    incoming := <-channel.Commands
+    if incoming.Packet == nil {
+      break
+    }
+
+    command := incoming.Packet
+
+    if command.Mode == MODE_CHANNEL {
+      switch command.Command {
+      case CHANNEL_COMMAND_JOIN:
+        members := channel.Members.Load().([]*ServerSession)
+        if slices.Contains(members, incoming.Session) == false {
+          new_members := make([]*ServerSession, len(members) + 1)
+          copy(new_members, members)
+          new_members[len(members)] = incoming.Session
+          channel.Members.Store(new_members)
+          fmt.Printf("New Members: %+v\n", channel.Members.Load())
+        }
+      case CHANNEL_COMMAND_LEAVE:
+        members := channel.Members.Load().([]*ServerSession)
+        idx := slices.Index(members, incoming.Session)
+        if idx != -1 {
+          new_members := make([]*ServerSession, len(members) - 1)
+          copy(new_members, members[:idx])
+          copy(new_members[idx:], members[idx+1:])
+          channel.Members.Store(new_members)
+          fmt.Printf("New Members: %+v\n", channel.Members.Load())
         }
-
-func(channel *Channel) Data(session *ServerSession, mode ModeID, data []byte) {
-  m, has_mode := channel.modes[mode]
+      }
+    } else {
+      mode, has_mode := channel.Modes[command.Mode]
       if has_mode {
-    m.Data(session, channel.id, channel.members, data)
+        members := channel.Members.Load().([]*ServerSession)
+        mode_val := mode.Load().(Mode)
+        new_mode := mode_val.Command(incoming.Session, command.Command, command.ReqID, command.Channel, members, command.Data)
+        mode.CompareAndSwap(mode_val, new_mode)
+      }
+    }
   }
 }
 
-func(channel *Channel) Command(session *ServerSession, command byte, request_id uuid.UUID, mode_id ModeID, data []byte) error {
-  mode, has_mode := channel.modes[mode_id]
-  if has_mode == false {
-    return fmt.Errorf("Channel has no mode 0x%02x", mode)
-  } else {
-    return mode.Command(session, command, request_id, channel.id, channel.members, data)
+func NewChannel(modes map[ModeID]Mode) (*Channel, error) {
+  initial_modes := map[ModeID]*atomic.Value{}
+  for mode_id, mode := range(modes) {
+    if mode_id == MODE_CHANNEL {
+      return nil, fmt.Errorf("Cannot create a channel with MODE_CHANNEL(0x%02x) mode", MODE_CHANNEL)
     }
+    initial_modes[mode_id] = new(atomic.Value)
+    initial_modes[mode_id].Store(mode)
   }
   
-func(channel *Channel) Join(client PeerID, session SessionID) {
+  channel := &Channel{
+    Commands: make(chan SessionChannelCommand, CHANNEL_COMMAND_BUFFER_SIZE),
+    Modes: initial_modes,
   }
+  channel.Members.Store([]*ServerSession{})
 
-func(channel *Channel) Leave(client PeerID, session SessionID) {
+  go channel.update_state()
+
+  return channel, nil
 }
 
 type Mode interface {
-  Command(session *ServerSession, command byte, request_id uuid.UUID, channel_id ChannelID, members []*ServerSession, data []byte) error
+  Command(session *ServerSession, command byte, request_id uuid.UUID, channel_id ChannelID, members []*ServerSession, data []byte) Mode
   Data(session *ServerSession, channel_id ChannelID, members []*ServerSession, data []byte)
-
-  Join(client PeerID, session SessionID)
-  Leave(client PeerID, session SessionID)
 }
 
 func multiplex_without_sender(origin SessionID, packet *Packet, sessions []*ServerSession) {
@@ -76,20 +119,15 @@ func multiplex(packet *Packet, sessions []*ServerSession) {
 type RawMode struct {
 }
 
-func(mode *RawMode) Command(session *ServerSession, command byte, request_id uuid.UUID, channel_id ChannelID, members []*ServerSession, data []byte) error {
-  return fmt.Errorf("unknown raw mode command 0x%02x", command)
+func(mode RawMode) Command(session *ServerSession, command byte, request_id uuid.UUID, channel_id ChannelID, members []*ServerSession, data []byte) Mode {
+  return mode
 }
 
-func(mode *RawMode) Data(session *ServerSession, channel_id ChannelID, members []*ServerSession, data []byte) {
-  new_packet := NewChannelPeerPacket(session.Peer, channel_id, MODE_RAW, data)
+func(mode RawMode) Data(session *ServerSession, channel_id ChannelID, members []*ServerSession, data []byte) {
+  new_packet := NewPeerPacket(session.Peer, channel_id, MODE_RAW, data)
   multiplex_without_sender(session.ID, new_packet, members)
 }
 
-func(mode *RawMode) Join(client PeerID, session SessionID) {
-}
-func(mode *RawMode) Leave(client PeerID, session SessionID) {
-}
-
 type SampleRate byte
 const (
   SAMPLE_RATE_UNSET SampleRate = 0xFF
@@ -101,7 +139,7 @@ type AudioMode struct {
   SampleRate SampleRate
 }
 
-func(mode *AudioMode) Command(session *ServerSession, command byte, request_id uuid.UUID, channel_id ChannelID, members []*ServerSession, data []byte) error {
+func(mode AudioMode) Command(session *ServerSession, command byte, request_id uuid.UUID, channel_id ChannelID, members []*ServerSession, data []byte) Mode {
   switch command {
   case AUDIO_SET_SAMPLE_RATE:
     if len(data) == 1 {
@@ -112,27 +150,16 @@ func(mode *AudioMode) Command(session *ServerSession, command byte, request_id u
         mode.SampleRate = SampleRate(data[0])
         update_packet := NewChannelCommandPacket(request_id, channel_id, MODE_AUDIO, AUDIO_SET_SAMPLE_RATE, data)
         multiplex(update_packet, members)
-        return nil
-      default:
-        return fmt.Errorf("Invalid sample rate: %x", data[0])
       }
-    } else {
-      return fmt.Errorf("Invalid AUDIO_SET_SAMPLE_RATE payload: %x", data)
     }
   case AUDIO_GET_SAMPLE_RATE:
     session.OutgoingPackets <- NewChannelCommandPacket(request_id, channel_id, MODE_AUDIO, AUDIO_SET_SAMPLE_RATE, []byte{byte(mode.SampleRate)})
-    return nil
-  default:
-    return fmt.Errorf("unknown audio mode command 0x%02x", command)
-  }
   }
   
-func(mode *AudioMode) Data(session *ServerSession, channel_id ChannelID, members []*ServerSession, data []byte) {
-  new_packet := NewChannelPeerPacket(session.Peer, channel_id, MODE_AUDIO, data)
-  multiplex_without_sender(session.ID, new_packet, members)
+  return mode
 }
 
-func(mode *AudioMode) Join(client PeerID, session SessionID) {
-}
-func(mode *AudioMode) Leave(client PeerID, session SessionID) {
+func(mode AudioMode) Data(session *ServerSession, channel_id ChannelID, members []*ServerSession, data []byte) {
+  new_packet := NewPeerPacket(session.Peer, channel_id, MODE_AUDIO, data)
+  multiplex_without_sender(session.ID, new_packet, members)
 }

cmd/client/main.go

@@ -4,14 +4,12 @@ import (
 	"encoding/binary"
 	"fmt"
 	"os"
-	"slices"
 	"time"
 
 	"git.metznet.ca/MetzNet/pnyx"
 	"github.com/gen2brain/malgo"
 	"github.com/google/uuid"
 	"github.com/hraban/opus"
-	"seehuhn.de/go/ncurses"
 )
 
 var decoders = map[pnyx.PeerID]chan[]byte{}
@@ -22,6 +20,7 @@ var speaker = make(chan []int16, 0)
 var audio_data = make(chan []int16, 0)
 
 func set_sample_rate(new_sample_rate int) error {
+  fmt.Printf("Setting sample rate to %d\n", new_sample_rate)
   sample_rate = new_sample_rate
 
   var err error
@@ -258,15 +257,18 @@ func main() {
       }
 
       switch packet := packet.(type) {
+      case pnyx.PingPacket:
+        fmt.Printf("Ping Packet From Server: %+v\n", packet)
       case pnyx.ChannelCommandPacket:
+        fmt.Printf("Channel Command packet: %+v\n", packet)
         if packet.Channel == pnyx.ChannelID(0) {
           if packet.Mode == pnyx.MODE_AUDIO {
             if packet.Command == pnyx.AUDIO_SET_SAMPLE_RATE {
               var new_sample_rate int
-              switch packet.Data[0] {
-              case byte(pnyx.SAMPLE_RATE_24KHZ):
+              switch pnyx.SampleRate(packet.Data[0]) {
+              case pnyx.SAMPLE_RATE_24KHZ:
                 new_sample_rate = 24000
-              case byte(pnyx.SAMPLE_RATE_48KHZ):
+              case pnyx.SAMPLE_RATE_48KHZ:
                 new_sample_rate = 48000
               default:
                 continue
@@ -278,7 +280,9 @@ func main() {
             }
           }
         }
-      case pnyx.ChannelPeerPacket:
+      case pnyx.CommandPacket:
+        fmt.Printf("Command packet: %+v\n", packet)
+      case pnyx.PeerPacket:
         if packet.Channel == pnyx.ChannelID(0) {
           decode_chan, exists := decoders[packet.Peer]
           if exists == false {
@@ -299,7 +303,7 @@ func main() {
     }
   }()
 
-  join_packet := pnyx.NewServerCommandPacket(uuid.New(), pnyx.SERVER_COMMAND_JOIN_CHANNEL, []byte{0x00})
+  join_packet := pnyx.NewChannelCommandPacket(uuid.New(), pnyx.ChannelID(0), pnyx.MODE_CHANNEL, pnyx.CHANNEL_COMMAND_JOIN, nil)
   err = client.Send(join_packet)
   if err != nil {
     panic(err)
@@ -311,17 +315,15 @@ func main() {
     panic(err)
   }
 
-  go func () {
   for true {
     data := <- mic
-      err = client.Send(pnyx.NewChannelDataPacket(pnyx.ChannelID(0), pnyx.MODE_AUDIO, data))
+    err = client.Send(pnyx.NewDataPacket(pnyx.ChannelID(0), pnyx.MODE_AUDIO, data))
     if err != nil {
       panic(err)
     }
   }
-  }()
 
-  window := ncurses.Init()
+  /*window := ncurses.Init()
   defer ncurses.EndWin()
 
   ncurses.ColorPair(1).Init(ncurses.ColorBlue, ncurses.ColorRed)
@@ -342,5 +344,5 @@ func main() {
     for i, peer_id := range(peers) {
       window.MvAddStr(i+1, 0, fmt.Sprintf("%x", peer_id))
     }
-  }
+  }*/
 }

cmd/server/main.go

@@ -13,19 +13,24 @@ func main() {
   os_sigs := make(chan os.Signal, 1)
   signal.Notify(os_sigs, syscall.SIGINT, syscall.SIGINT)
 
-  server, err := pnyx.NewServer(nil)
+  channel_0, err := pnyx.NewChannel(map[pnyx.ModeID]pnyx.Mode{
+    pnyx.MODE_RAW: pnyx.RawMode{},
+    pnyx.MODE_AUDIO: pnyx.AudioMode{
+      SampleRate: pnyx.SAMPLE_RATE_48KHZ,
+    },
+  })
   if err != nil {
     panic(err)
   }
 
-  err = server.Start(os.Args[1])
+  server, err := pnyx.NewServer(nil, map[pnyx.ChannelID]*pnyx.Channel{
+    0: channel_0,
+  })
   if err != nil {
     panic(err)
   }
 
-  err = server.AddChannel(pnyx.ChannelID(0), &pnyx.RawMode{}, &pnyx.AudioMode{
-    SampleRate: pnyx.SAMPLE_RATE_24KHZ,
-  })
+  err = server.Start(os.Args[1])
   if err != nil {
     panic(err)
   }

packet.go

@@ -11,16 +11,18 @@ type PacketType uint8
 const (
   PACKET_SERVER_COMMAND PacketType = iota
   PACKET_CHANNEL_COMMAND 
-  PACKET_CHANNEL_DATA
-  PACKET_CHANNEL_PEER
+  PACKET_DATA
+  PACKET_PEER
+  PACKET_PING
 
   CHANNEL_HEADER_LEN int = 2
   CHANNEL_COMMAND_LEN = CHANNEL_HEADER_LEN + COMMAND_LENGTH + REQ_ID_LENGTH
   CHANNEL_PEER_LEN = CHANNEL_HEADER_LEN + PEER_ID_LENGTH
 
-  SERVER_COMMAND_JOIN_CHANNEL byte = iota
-  SERVER_COMMAND_LEAVE_CHANNEL
-  SERVER_COMMAND_ADD_CHANNEL
+  CHANNEL_COMMAND_JOIN byte = iota
+  CHANNEL_COMMAND_LEAVE
+
+  SERVER_COMMAND_ADD_CHANNEL byte = iota
   SERVER_COMMAND_DEL_CHANNEL
 )
 
@@ -49,25 +51,49 @@ func ParsePacket(data []byte) (Payload, error) {
 
   switch PacketType(data[0]) {
   case PACKET_SERVER_COMMAND:
-    return ParseServerCommandPacket(data[1:])
-  case PACKET_CHANNEL_DATA:
-    return ParseChannelDataPacket(data[1:])
+    return ParseCommandPacket(data[1:])
   case PACKET_CHANNEL_COMMAND:
     return ParseChannelCommandPacket(data[1:])
-  case PACKET_CHANNEL_PEER:
-    return ParseChannelPeerPacket(data[1:])
+  case PACKET_DATA:
+    return ParseDataPacket(data[1:])
+  case PACKET_PEER:
+    return ParsePeerPacket(data[1:])
+  case PACKET_PING:
+    return ParsePingPacket(data[1:])
   default:
     return nil, fmt.Errorf("Don't know how to parse packet type 0x%02x", data[0])
   }
 }
 
-type ServerCommandPacket struct {
+type PingPacket struct {
+}
+
+func(packet PingPacket) MarshalBinary() ([]byte, error) {
+  return []byte{}, nil
+}
+
+func NewPingPacket() *Packet {
+  return &Packet{
+    Type: PACKET_PING,
+    Payload: PingPacket{},
+  }
+}
+
+func ParsePingPacket(data []byte) (PingPacket, error) {
+  if len(data) != 0 {
+    return PingPacket{}, fmt.Errorf("Wrong number of bytes to parse PingPacket %d/0", len(data))
+  }
+
+  return PingPacket{}, nil
+}
+
+type CommandPacket struct {
   ReqID uuid.UUID
   Command byte
   Data []byte
 }
 
-func (packet ServerCommandPacket) MarshalBinary() ([]byte, error) {
+func (packet CommandPacket) MarshalBinary() ([]byte, error) {
   p := make([]byte, 17 + len(packet.Data))
   copy(p, packet.ReqID[:])
   p[16] = packet.Command
@@ -76,10 +102,10 @@ func (packet ServerCommandPacket) MarshalBinary() ([]byte, error) {
   return p, nil
 }
 
-func NewServerCommandPacket(request_id uuid.UUID, command byte, data []byte) *Packet {
+func NewCommandPacket(request_id uuid.UUID, command byte, data []byte) *Packet {
   return &Packet{
     Type: PACKET_SERVER_COMMAND,
-    Payload: ServerCommandPacket{
+    Payload: CommandPacket{
       ReqID: request_id,
       Command: command,
       Data: data,
@@ -87,12 +113,12 @@ func NewServerCommandPacket(request_id uuid.UUID, command byte, data []byte) *Pa
   }
 }
 
-func ParseServerCommandPacket(data []byte) (ServerCommandPacket, error) {
+func ParseCommandPacket(data []byte) (CommandPacket, error) {
   if len(data) < 17 {
-    return ServerCommandPacket{}, fmt.Errorf("Not enough data to decode ServerCommandPacket: %d/%d", len(data), 17)
+    return CommandPacket{}, fmt.Errorf("Not enough data to decode CommandPacket: %d/%d", len(data), 17)
   }
 
-  return ServerCommandPacket{
+  return CommandPacket{
     ReqID: uuid.UUID(data[0:16]),
     Command: data[16],
     Data: data[17:],
@@ -175,16 +201,16 @@ func ParseChannelCommandPacket(data []byte) (ChannelCommandPacket, error) {
   }, nil
 }
 
-type ChannelPeerPacket struct {
+type PeerPacket struct {
   ChannelHeader
   Peer PeerID
   Data []byte
 }
 
-func NewChannelPeerPacket(peer PeerID, channel ChannelID, mode ModeID, data []byte) *Packet {
+func NewPeerPacket(peer PeerID, channel ChannelID, mode ModeID, data []byte) *Packet {
   return &Packet{
-    Type: PACKET_CHANNEL_PEER,
-    Payload: ChannelPeerPacket{
+    Type: PACKET_PEER,
+    Payload: PeerPacket{
       ChannelHeader: ChannelHeader{
         Channel: channel,
         Mode: mode,
@@ -195,7 +221,7 @@ func NewChannelPeerPacket(peer PeerID, channel ChannelID, mode ModeID, data []by
   }
 }
 
-func(packet ChannelPeerPacket) MarshalBinary() ([]byte, error) {
+func(packet PeerPacket) MarshalBinary() ([]byte, error) {
   header, err := packet.ChannelHeader.MarshalBinary()
   if err != nil {
     return nil, err
@@ -205,17 +231,17 @@ func(packet ChannelPeerPacket) MarshalBinary() ([]byte, error) {
   return append(data, packet.Data...), nil
 }
 
-func ParseChannelPeerPacket(data []byte) (ChannelPeerPacket, error) {
+func ParsePeerPacket(data []byte) (PeerPacket, error) {
   if len(data) < CHANNEL_PEER_LEN {
-    return ChannelPeerPacket{}, fmt.Errorf("Not enough bytes to parse ServerChannelPacket: %d/%d", len(data), PEER_ID_LENGTH)
+    return PeerPacket{}, fmt.Errorf("Not enough bytes to parse ServerChannelPacket: %d/%d", len(data), PEER_ID_LENGTH)
   }
 
   header, err := ParseChannelHeader(data)
   if err != nil {
-    return ChannelPeerPacket{}, err
+    return PeerPacket{}, err
   }
 
-  return ChannelPeerPacket{
+  return PeerPacket{
     ChannelHeader: header,
     Peer: PeerID(data[CHANNEL_HEADER_LEN:]),
     Data: data[CHANNEL_PEER_LEN:],
@@ -223,15 +249,15 @@ func ParseChannelPeerPacket(data []byte) (ChannelPeerPacket, error) {
 }
 
 
-type ChannelDataPacket struct {
+type DataPacket struct {
   ChannelHeader
   Data []byte
 }
 
-func NewChannelDataPacket(channel ChannelID, mode ModeID, data []byte) *Packet {
+func NewDataPacket(channel ChannelID, mode ModeID, data []byte) *Packet {
   return &Packet{
-    Type: PACKET_CHANNEL_DATA,
-    Payload: ChannelDataPacket{
+    Type: PACKET_DATA,
+    Payload: DataPacket{
       ChannelHeader: ChannelHeader{
         Channel: channel,
         Mode: mode,
@@ -241,7 +267,7 @@ func NewChannelDataPacket(channel ChannelID, mode ModeID, data []byte) *Packet {
   }
 }
 
-func(packet ChannelDataPacket) MarshalBinary() ([]byte, error) {
+func(packet DataPacket) MarshalBinary() ([]byte, error) {
   header, err := packet.ChannelHeader.MarshalBinary()
   if err != nil {
     return nil, err
@@ -250,17 +276,17 @@ func(packet ChannelDataPacket) MarshalBinary() ([]byte, error) {
   return append(header, packet.Data...), nil
 }
 
-func ParseChannelDataPacket(data []byte) (ChannelDataPacket, error) {
+func ParseDataPacket(data []byte) (DataPacket, error) {
   if len(data) < CHANNEL_HEADER_LEN {
-    return ChannelDataPacket{}, fmt.Errorf("Not enough data to parse ChannelDataPacket")
+    return DataPacket{}, fmt.Errorf("Not enough data to parse DataPacket")
   }
 
   header, err := ParseChannelHeader(data)
   if err != nil {
-    return ChannelDataPacket{}, nil
+    return DataPacket{}, nil
   }
 
-  return ChannelDataPacket{
+  return DataPacket{
     ChannelHeader: header,
     Data: data[CHANNEL_HEADER_LEN:],
   }, nil

server.go

@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"net"
 	"os"
-	"reflect"
 	"slices"
 	"sync"
 	"sync/atomic"
@@ -17,6 +16,7 @@ import (
 const (
  SERVER_UDP_BUFFER_SIZE = 2048
  SERVER_SEND_BUFFER_SIZE = 2048
+ SERVER_COMMAND_BUFFER_SIZE = 2048
 )
 
 type RoleID uint32
@@ -25,7 +25,7 @@ type ServerSession struct {
   Session
   LastSeen time.Time
   IncomingPackets chan[]byte
-  OutgoingPackets chan *Packet
+  OutgoingPackets chan Payload
   Channels []ChannelID
 }
 
@@ -34,19 +34,17 @@ type Server struct {
   active atomic.Bool
   connection *net.UDPConn
   stopped chan error
-
-  modes map[reflect.Type]ModeID
+  commands chan Payload
 
   sessions_lock sync.Mutex
   sessions map[SessionID]*ServerSession
 
-  channels_lock sync.RWMutex
-  channels map[ChannelID]*Channel
+  channels atomic.Value
 
   peers map[PeerID][]RoleID
 }
 
-func NewServer(key ed25519.PrivateKey) (*Server, error) {
+func NewServer(key ed25519.PrivateKey, channels map[ChannelID]*Channel) (*Server, error) {
   if key == nil {
     var err error
     _, key, err = ed25519.GenerateKey(rand.Reader)
@@ -59,67 +57,18 @@ func NewServer(key ed25519.PrivateKey) (*Server, error) {
     connection: nil,
     active: atomic.Bool{},
     stopped: make(chan error, 0),
-
-    modes: map[reflect.Type]ModeID{
-      reflect.TypeFor[*RawMode](): MODE_RAW,
-      reflect.TypeFor[*AudioMode](): MODE_AUDIO,
-    },
+    commands: make(chan Payload, SERVER_COMMAND_BUFFER_SIZE),
 
     sessions: map[SessionID]*ServerSession{},
-    channels: map[ChannelID]*Channel{},
+    channels: atomic.Value{},
 
     peers: map[PeerID][]RoleID{},
   }
+  server.channels.Store(channels)
   server.active.Store(false)
   return server, nil
 }
 
-func(server *Server) RemoveChannel(id ChannelID) error {
-  server.channels_lock.Lock()
-  defer server.channels_lock.Unlock()
-
-  _, exists := server.channels[id]
-  if exists == false {
-    return fmt.Errorf("Channel %x does not exist", id)
-  }
-
-  delete(server.channels, id)
-  return nil
-}
-
-func(server *Server) AddChannel(id ChannelID, modes ...Mode) error {
-  server.channels_lock.Lock()
-  defer server.channels_lock.Unlock()
-
-  _, exists := server.channels[id]
-  if exists {
-    return fmt.Errorf("Channel with ID %x already exists", id)
-  }
-
-  mode_map := map[ModeID]Mode{}
-  for _, mode := range(modes) {
-    reflect_type := reflect.TypeOf(mode)
-    mode_id, known := server.modes[reflect_type]
-    if known == false {
-      return fmt.Errorf("Can't create channel with unknown mode: %s", reflect_type)
-    }
-
-    _, exists := mode_map[mode_id]
-    if exists {
-      return fmt.Errorf("Can't create channel with duplicate ModeID %x", mode_id) 
-    }
-    mode_map[mode_id] = mode
-  }
-
-  server.channels[id] = &Channel{
-    id: id,
-    modes: mode_map,
-    members: []*ServerSession{},
-  }
-
-  return nil
-}
-
 func(server *Server) Log(format string, fields ...interface{}) {
   fmt.Fprint(os.Stderr, fmt.Sprintf(format, fields...) + "\n")
 }
@@ -173,12 +122,34 @@ func handle_session_outgoing(session *ServerSession, server *Server) {
   server.Log("Stopping session outgoing goroutine %s", session.ID)
 }
 
+const SESSION_PING_TIME = time.Minute
+const SESSION_TIMEOUT = 2 * time.Minute
+
+type SessionChannelCommand struct {
+  Session *ServerSession
+  Packet *ChannelCommandPacket
+}
+
 func handle_session_incoming(session *ServerSession, server *Server) {
   server.Log("Starting session incoming goroutine %s", session.ID)
-  for true {
-    encrypted := <- session.IncomingPackets
+  ping_timer := time.After(SESSION_PING_TIME)
+  running := true
+  for running {
+    select {
+    case <- ping_timer:
+      if time.Now().Add(-1*SESSION_TIMEOUT).Compare(session.LastSeen) != 1 {
+        server.sessions_lock.Lock()
+        server.close_session(session)  
+        server.sessions_lock.Unlock()
+        running = false
+      } else {
+        session.OutgoingPackets <- NewPingPacket()
+        ping_timer = time.After(SESSION_PING_TIME)
+      }
+    case encrypted := <- session.IncomingPackets:
       if encrypted == nil {
-      break
+        running = false
+        continue
       }
 
       data, err := ParseSessionData(&session.Session, encrypted)
@@ -193,74 +164,38 @@ func handle_session_incoming(session *ServerSession, server *Server) {
       }
 
       switch packet := packet.(type) {
-    case ServerCommandPacket:
-      switch packet.Command {
-      case SERVER_COMMAND_JOIN_CHANNEL:
-        server.Log("Got join_channel for %x with %x", session.ID, packet.Data)
-        if len(packet.Data) == 1 {
-          server.channels_lock.Lock()
-          channel, exists := server.channels[ChannelID(packet.Data[0])]
-          if exists == true {
-            if slices.Contains(channel.members, session) == false {
-              channel.members = append(channel.members, session)
-              channel.Join(session.Peer, session.ID)
-              // TODO: Send message to clients to notify of join
-            }
-          }
-          server.channels_lock.Unlock()
-        }
-      case SERVER_COMMAND_LEAVE_CHANNEL:
-        server.Log("Got leave_channel for %x with %x", session.ID, packet.Data)
-        if len(packet.Data) == 1 {
-          server.channels_lock.Lock()
-          channel, exists := server.channels[ChannelID(packet.Data[0])]
-          if exists == true {
-            idx := slices.Index(channel.members, session)
-            if idx != -1 {
-              channel.members = slices.Delete(channel.members, idx, idx+1)
-              channel.Leave(session.Peer, session.ID)
-              // TODO: Send message to clients to notify of join
-            }
-          }
-          server.channels_lock.Unlock()
-        }
-      case SERVER_COMMAND_ADD_CHANNEL:
-        server.Log("Got add_channel with %x", packet.Data)
-      case SERVER_COMMAND_DEL_CHANNEL:
-        server.Log("Got del_channel with %x", packet.Data)
-      default:
-        server.Log("Unknown server command %x", packet.Command)
-      }
-    case ChannelDataPacket:
-      server.channels_lock.RLock()
-      channel, exists := server.channels[packet.Channel]
+      case CommandPacket:
+        server.commands<-packet
+      case ChannelCommandPacket:
+        channels := server.channels.Load().(map[ChannelID]*Channel)
+        channel, exists := channels[packet.Channel]
         if exists == true {
-        if slices.Contains(channel.members, session) {
-          channel.Data(session, packet.Mode, packet.Data)
+          channel.Commands<-SessionChannelCommand{
+            Session: session,
+            Packet: &packet,
           }
         } else {
-        server.Log("Packet for unknown channel %d", packet.Channel)
+          server.Log("Command for unknown channel %d", packet.Channel)
         }
-      server.channels_lock.RUnlock()
-
-
-    case ChannelCommandPacket:
-      server.channels_lock.RLock()
-      channel, exists := server.channels[packet.Channel]
+      case DataPacket:
+        channels := server.channels.Load().(map[ChannelID]*Channel)
+        channel, exists := channels[packet.Channel]
         if exists == true {
-        err = channel.Command(session, packet.Command, packet.ReqID, packet.Mode, packet.Data)
-        if err != nil {
-          server.Log("Error processing %+v - %s", packet, err)
+          members := channel.Members.Load().([]*ServerSession)
+          if slices.Contains(members, session) {
+            mode, has_mode := channel.Modes[packet.Mode]
+            if has_mode {
+              mode.Load().(Mode).Data(session, packet.Channel, members, data)
+            }
           }
         } else {
-        server.Log("Packet for unknown channel %d", packet.Channel)
+          server.Log("Data for unknown channel %d", packet.Channel)
         }
-      server.channels_lock.RUnlock()
-
 
       default:
         server.Log("Unhandled packet type from session %s - 0x%02x", session.ID, err)
       }
+    }
 
   }
   server.Log("Stopping session incoming goroutine %s", session.ID)
@@ -277,7 +212,7 @@ func(server *Server) handle_session_open(client_session_open []byte, from *net.U
     Session: session,
     LastSeen: time.Now(),
     IncomingPackets: make(chan[]byte, SESSION_BUFFER_SIZE),
-    OutgoingPackets: make(chan *Packet, SESSION_BUFFER_SIZE),
+    OutgoingPackets: make(chan Payload, SESSION_BUFFER_SIZE),
   }
   server.sessions_lock.Unlock()
 
@@ -406,11 +341,17 @@ func(server *Server) listen_udp() {
     }
   }
 
+  channels := server.channels.Load().(map[ChannelID]*Channel)
+  for _, channel := range(channels) {
+    close(channel.Commands)
+  }
+
   server.sessions_lock.Lock()
   sessions := make([]*ServerSession, 0, len(server.sessions))
   for _, session := range(server.sessions) {  
     sessions = append(sessions, session)
   }
+
   for _, session := range(sessions) {
     server.close_session(session)
   }
@@ -424,31 +365,16 @@ func(server *Server) close_session(session *ServerSession) {
   close(session.IncomingPackets)
   close(session.OutgoingPackets)
   delete(server.sessions, session.ID)
-}
 
-const SESSION_TIMEOUT = time.Minute * 5
-const SESSION_TIMEOUT_CHECK = time.Minute
+  session_closed := NewSessionTimed(SESSION_CLOSED, server.key, &session.Session, time.Now())
+  server.connection.WriteToUDP(session_closed, session.remote)
+}
 
-func(server *Server) cleanup_sessions() {
+func(server *Server) update_state() {
   for server.active.Load() {
     select {
-    case <-time.After(SESSION_TIMEOUT_CHECK):
-      server.sessions_lock.Lock()
-      now := time.Now()
-      stale_sessions := make([]*ServerSession, 0, len(server.sessions))
-      for _, session := range(server.sessions) {
-        if now.Sub(session.LastSeen) >= SESSION_TIMEOUT {
-          server.Log("Closing stale session %s for %s", session.ID, session.Peer)
-          stale_sessions = append(stale_sessions, session)
-        }
-      }
-
-      for _, session := range(stale_sessions) {
-        server.close_session(session)
-      }
-
-      server.sessions_lock.Unlock()
-    // TODO: add a way for this to be shutdown instantly on server shutdown
+    case command := <-server.commands:
+      server.Log("Incoming server command %+v", command)
     }
   }
 }
@@ -472,7 +398,7 @@ func(server *Server) Start(listen string) error {
   }
 
   go server.listen_udp()
-  go server.cleanup_sessions()
+  go server.update_state()
 
   return nil
 }