server: allow the permission level a client displays for itself to be set

server/player/conf.go

@@ -9,6 +9,7 @@ import (
 	"github.com/df-mc/dragonfly/server/entity"
 	"github.com/df-mc/dragonfly/server/entity/effect"
 	"github.com/df-mc/dragonfly/server/item/inventory"
+	"github.com/df-mc/dragonfly/server/player/permission"
 	"github.com/df-mc/dragonfly/server/player/skin"
 	"github.com/df-mc/dragonfly/server/session"
 	"github.com/df-mc/dragonfly/server/world"
@@ -27,6 +28,9 @@ type Config struct {
 	Locale   language.Tag
 	GameMode world.GameMode
 
+	// PermissionLevel is the permission level the client displays for itself.
+	PermissionLevel permission.Level
+
 	Position               mgl64.Vec3
 	Rotation               cube.Rotation
 	Velocity               mgl64.Vec3
@@ -72,6 +76,7 @@ func (cfg Config) Apply(data *world.EntityData) {
 		mc:                  &entity.MovementComputer{Gravity: 0.08, Drag: 0.02, DragBeforeGravity: true},
 		heldSlot:            &slot,
 		gameMode:            conf.GameMode,
+		permission:          conf.PermissionLevel,
 		skin:                conf.Skin,
 		enchantSeed:         conf.EnchantmentSeed,
 		s:                   conf.Session,

server/player/permission/level.go

@@ -0,0 +1,34 @@
+package permission
+
+import (
+	"github.com/sandertv/gophertunnel/minecraft/protocol"
+	"github.com/sandertv/gophertunnel/minecraft/protocol/packet"
+)
+
+// Level represents the permission level a client displays for itself. It only decides what the client shows
+// and allows locally, such as the command button in the chat window: the server does not use it to authorise
+// anything. Whether a player may run a command is decided by cmd.Allower alone.
+type Level struct {
+	level
+}
+
+type level uint8
+
+// Member is the level of an ordinary client. It is the level a player has unless another one is set.
+func Member() Level {
+	return Level{0}
+}
+
+// Operator is the level of a client that vanilla considers an operator.
+func Operator() Level {
+	return Level{1}
+}
+
+// Permissions returns the player permission level and command permission level sent to a client for the
+// Level.
+func (l level) Permissions() (byte, byte) {
+	if l == 1 {
+		return packet.PermissionLevelOperator, protocol.CommandPermissionLevelGameDirectors
+	}
+	return packet.PermissionLevelMember, protocol.CommandPermissionLevelAny
+}

server/player/player.go

@@ -28,6 +28,7 @@ import (
 	"github.com/df-mc/dragonfly/server/player/form"
 	"github.com/df-mc/dragonfly/server/player/hud"
 	"github.com/df-mc/dragonfly/server/player/input"
+	"github.com/df-mc/dragonfly/server/player/permission"
 	"github.com/df-mc/dragonfly/server/player/scoreboard"
 	"github.com/df-mc/dragonfly/server/player/skin"
 	"github.com/df-mc/dragonfly/server/player/title"
@@ -48,10 +49,11 @@ type playerData struct {
 	absorptionHealth  float64
 	scale             float64
 
-	gameMode world.GameMode
-	skin     skin.Skin
-	s        *session.Session
-	h        Handler
+	gameMode   world.GameMode
+	permission permission.Level
+	skin       skin.Skin
+	s          *session.Session
+	h          Handler
 
 	inv, offHand, enderChest, ui *inventory.Inventory
 	armour                       *inventory.Armour
@@ -1546,6 +1548,25 @@ func (p *Player) GameMode() world.GameMode {
 	return p.gameMode
 }
 
+// SetPermissionLevel changes the permission level the Player's client displays
+// for itself. It unlocks vanilla functionality that the client restricts to a
+// permission level, such as the command button in the chat window, but does not
+// authorise the Player to do anything by itself: cmd.Allower decides which
+// commands a Player may run.
+func (p *Player) SetPermissionLevel(level permission.Level) {
+	if p.permission == level {
+		return
+	}
+	p.permission = level
+	p.session().SendAbilities(p)
+}
+
+// PermissionLevel returns the permission level the Player's client displays for
+// itself, as set by SetPermissionLevel.
+func (p *Player) PermissionLevel() permission.Level {
+	return p.permission
+}
+
 // HasCooldown returns true if the item passed has an active cooldown, meaning it currently cannot be used again. If the
 // world.Item passed is nil, HasCooldown always returns false.
 func (p *Player) HasCooldown(item world.Item) bool {
@@ -3388,6 +3409,7 @@ func (p *Player) Data() Config {
 		Name:                p.nameTag,
 		Locale:              p.locale,
 		GameMode:            p.gameMode,
+		PermissionLevel:     p.permission,
 		Position:            p.Position(),
 		Rotation:            p.Rotation(),
 		Velocity:            p.Velocity(),

server/server.go

@@ -474,6 +474,8 @@ func (srv *Server) finaliseConn(ctx context.Context, conn session.Conn, l Listen
 	data.Dimension = int32(dim)
 	data.Yaw, data.Pitch = float32(d.Rotation.Yaw()), float32(d.Rotation.Pitch())
 
+	data.PlayerPermissions, _ = d.PermissionLevel.Permissions()
+
 	data.EmoteChatMuted = srv.conf.MuteEmoteChat
 
 	if err := conn.StartGameContext(ctx, data); err != nil {

server/session/controllable.go

@@ -12,6 +12,7 @@ import (
 	"github.com/df-mc/dragonfly/server/player/form"
 	"github.com/df-mc/dragonfly/server/player/hud"
 	"github.com/df-mc/dragonfly/server/player/input"
+	"github.com/df-mc/dragonfly/server/player/permission"
 	"github.com/df-mc/dragonfly/server/player/skin"
 	"github.com/df-mc/dragonfly/server/world"
 	"github.com/go-gl/mathgl/mgl64"
@@ -51,6 +52,7 @@ type Controllable interface {
 	Chat(msg ...any)
 	ExecuteCommand(commandLine string)
 	GameMode() world.GameMode
+	PermissionLevel() permission.Level
 	SetGameMode(mode world.GameMode)
 	Effects() []effect.Effect
 

server/session/player.go

@@ -545,10 +545,11 @@ func (s *Session) SendAbilities(c Controllable) {
 	if mode.AllowsInteraction() {
 		abilities |= protocol.AbilityDoorsAndSwitches | protocol.AbilityOpenContainers | protocol.AbilityAttackPlayers | protocol.AbilityAttackMobs
 	}
+	perm, cmdPerm := c.PermissionLevel().Permissions()
 	s.writePacket(&packet.UpdateAbilities{AbilityData: protocol.AbilityData{
 		EntityUniqueID:     selfEntityRuntimeID,
-		PlayerPermissions:  packet.PermissionLevelMember,
-		CommandPermissions: protocol.CommandPermissionLevelAny,
+		PlayerPermissions:  perm,
+		CommandPermissions: cmdPerm,
 		Layers: []protocol.AbilityLayer{
 			{
 				Type:             protocol.AbilityLayerTypeBase,