Merge pull request #5 from HimbeerserverDE/main

fetch upstream

chat.go

@@ -9,6 +9,10 @@ import (
 	"github.com/anon55555/mt"
 )
 
+// ChatCmdTimeout is the time needed until a user is warned
+// about a chat command that's taking long to execute.
+var ChatCmdTimeout = 10 * time.Second
+
 // SendChatMsg sends a chat message to the ClientConn.
 func (cc *ClientConn) SendChatMsg(msg ...string) {
 	cc.SendCmd(&mt.ToCltChatMsg{

config.go

@@ -2,6 +2,7 @@ package proxy
 
 import (
 	"encoding/json"
+	"fmt"
 	"log"
 	"os"
 	"sync"
@@ -25,7 +26,10 @@ var loadConfigOnce sync.Once
 type Server struct {
 	Name      string
 	Addr      string
+	MediaPool string
 	Fallbacks []string
+
+	dynamic bool
 }
 
 // A Config contains information from the configuration file
@@ -87,34 +91,78 @@ func Conf() Config {
 	return config
 }
 
-// AddServer appends a server to the list of configured servers.
-func AddServer(server Server) bool {
+// PoolServers returns all media pools and their member servers.
+func PoolServers() map[string][]Server {
+	var srvs = make(map[string][]Server)
+	conf := Conf()
+
+	// map all to.. map of slices
+	for _, srv := range conf.Servers {
+		srvs[srv.MediaPool] = append(srvs[srv.MediaPool], srv)
+	}
+
+	return srvs
+}
+
+// AddServer dynamically configures a new Server at runtime.
+// Servers added in this way are ephemeral and will be lost
+// when the proxy shuts down.
+// The server must be part of a media pool with at least one
+// other member. At least one of the other members always
+// needs to be reachable.
+func AddServer(s Server) bool {
 	configMu.Lock()
 	defer configMu.Unlock()
 
+	s.dynamic = true
+
 	for _, srv := range config.Servers {
-		if srv.Name == server.Name {
+		if srv.Name == s.Name {
 			return false
 		}
 	}
 
-	config.Servers = append(config.Servers, server)
+	var poolMembers bool
+	for _, srv := range config.Servers {
+		if srv.MediaPool == s.MediaPool {
+			poolMembers = true
+		}
+	}
+
+	if !poolMembers {
+		return false
+	}
+
+	config.Servers = append(config.Servers, s)
 	return true
 }
 
-// DelServer removes a server based on name.
-func DelServer(name string) bool {
+// RmServer deletes a Server from the Config at runtime.
+// Only servers added using AddServer can be deleted at runtime.
+// Returns true on success or if the server doesn't exist.
+func RmServer(name string) bool {
 	configMu.Lock()
 	defer configMu.Unlock()
 
 	for i, srv := range config.Servers {
 		if srv.Name == name {
+			if srv.dynamic {
+				return false
+			}
+
+			// Can't remove server if players are connected to it
+			for cc := range Clts() {
+				if cc.ServerName() == name {
+					return false
+				}
+			}
+
 			config.Servers = append(config.Servers[:i], config.Servers[1+i:]...)
 			return true
 		}
 	}
 
-	return false
+	return true
 }
 
 // FallbackServers returns a slice of server names that
@@ -185,6 +233,40 @@ func LoadConfig() error {
 		return err
 	}
 
+	// Dynamic servers shouldn't be deleted silently.
+DynLoop:
+	for _, srv := range oldConf.Servers {
+		if srv.dynamic {
+			config.Servers = append(config.Servers, srv)
+		} else {
+			for _, s := range config.Servers {
+				if srv.Name == s.Name {
+					continue DynLoop
+				}
+			}
+
+			for cc := range Clts() {
+				if cc.ServerName() == srv.Name {
+					config = oldConf
+					return fmt.Errorf("can't delete server %s with players", srv.Name)
+				}
+			}
+		}
+	}
+
+	for i, srv := range config.Servers {
+		for _, s := range config.Servers {
+			if srv.Name == s.Name {
+				config = oldConf
+				return fmt.Errorf("duplicate server %s", s.Name)
+			}
+		}
+
+		if srv.MediaPool == "" {
+			config.Servers[i].MediaPool = srv.Name
+		}
+	}
+
 	log.Print("load config")
 	return nil
 }

connect.go

@@ -17,13 +17,21 @@ func connect(conn net.Conn, name string, cc *ClientConn) *ServerConn {
 	}
 	cc.mu.RUnlock()
 
-	prefix := fmt.Sprintf("[server %s] ", name)
+	var mediaPool string
+	for _, srv := range Conf().Servers {
+		if srv.Name == name {
+			mediaPool = srv.MediaPool
+		}
+	}
+
+	logPrefix := fmt.Sprintf("[server %s] ", name)
 	sc := &ServerConn{
 		Peer:             mt.Connect(conn),
-		logger:           log.New(logWriter, prefix, log.LstdFlags|log.Lmsgprefix),
+		logger:           log.New(logWriter, logPrefix, log.LstdFlags|log.Lmsgprefix),
 		initCh:           make(chan struct{}),
 		clt:              cc,
 		name:             name,
+		mediaPool:        mediaPool,
 		aos:              make(map[mt.AOID]struct{}),
 		particleSpawners: make(map[mt.ParticleSpawnerID]struct{}),
 		sounds:           make(map[mt.SoundID]struct{}),
@@ -40,14 +48,15 @@ func connect(conn net.Conn, name string, cc *ClientConn) *ServerConn {
 	return sc
 }
 
-func connectContent(conn net.Conn, name, userName string) (*contentConn, error) {
-	prefix := fmt.Sprintf("[content %s] ", name)
+func connectContent(conn net.Conn, name, userName, mediaPool string) (*contentConn, error) {
+	logPrefix := fmt.Sprintf("[content %s] ", name)
 	cc := &contentConn{
-		Peer:     mt.Connect(conn),
-		logger:   log.New(logWriter, prefix, log.LstdFlags|log.Lmsgprefix),
-		doneCh:   make(chan struct{}),
-		name:     name,
-		userName: userName,
+		Peer:      mt.Connect(conn),
+		logger:    log.New(logWriter, logPrefix, log.LstdFlags|log.Lmsgprefix),
+		doneCh:    make(chan struct{}),
+		name:      name,
+		userName:  userName,
+		mediaPool: mediaPool,
 	}
 
 	if err := cc.addDefaultTextures(); err != nil {

content.go

@@ -45,6 +45,8 @@ type contentConn struct {
 		salt, srpA, a, srpK []byte
 	}
 
+	mediaPool string
+
 	itemDefs []mt.ItemDef
 	aliases  []struct{ Alias, Orig string }
 
@@ -357,21 +359,21 @@ func muxItemDefs(conns []*contentConn) ([]mt.ItemDef, []struct{ Alias, Orig stri
 				def.Name = "hand"
 			}
 
-			prepend(cc.name, &def.Name)
-			prependTexture(cc.name, &def.InvImg)
-			prependTexture(cc.name, &def.WieldImg)
-			prepend(cc.name, &def.PlacePredict)
-			prepend(cc.name, &def.PlaceSnd.Name)
-			prepend(cc.name, &def.PlaceFailSnd.Name)
-			prependTexture(cc.name, &def.Palette)
-			prependTexture(cc.name, &def.InvOverlay)
-			prependTexture(cc.name, &def.WieldOverlay)
+			prepend(cc.mediaPool, &def.Name)
+			prependTexture(cc.mediaPool, &def.InvImg)
+			prependTexture(cc.mediaPool, &def.WieldImg)
+			prepend(cc.mediaPool, &def.PlacePredict)
+			prepend(cc.mediaPool, &def.PlaceSnd.Name)
+			prepend(cc.mediaPool, &def.PlaceFailSnd.Name)
+			prependTexture(cc.mediaPool, &def.Palette)
+			prependTexture(cc.mediaPool, &def.InvOverlay)
+			prependTexture(cc.mediaPool, &def.WieldOverlay)
 			itemDefs = append(itemDefs, def)
 		}
 
 		for _, alias := range cc.aliases {
-			prepend(cc.name, &alias.Alias)
-			prepend(cc.name, &alias.Orig)
+			prepend(cc.mediaPool, &alias.Alias)
+			prepend(cc.mediaPool, &alias.Orig)
 
 			aliases = append(aliases, struct{ Alias, Orig string }{
 				Alias: alias.Alias,
@@ -429,25 +431,25 @@ func muxNodeDefs(conns []*contentConn) (nodeDefs []mt.NodeDef, p0Map param0Map,
 			}
 
 			def.Param0 = param0
-			prepend(cc.name, &def.Name)
-			prepend(cc.name, &def.Mesh)
+			prepend(cc.mediaPool, &def.Name)
+			prepend(cc.mediaPool, &def.Mesh)
 			for i := range def.Tiles {
-				prependTexture(cc.name, &def.Tiles[i].Texture)
+				prependTexture(cc.mediaPool, &def.Tiles[i].Texture)
 			}
 			for i := range def.OverlayTiles {
-				prependTexture(cc.name, &def.OverlayTiles[i].Texture)
+				prependTexture(cc.mediaPool, &def.OverlayTiles[i].Texture)
 			}
 			for i := range def.SpecialTiles {
-				prependTexture(cc.name, &def.SpecialTiles[i].Texture)
+				prependTexture(cc.mediaPool, &def.SpecialTiles[i].Texture)
 			}
-			prependTexture(cc.name, &def.Palette)
+			prependTexture(cc.mediaPool, &def.Palette)
 			for k, v := range def.ConnectTo {
 				def.ConnectTo[k] = p0Map[cc.name][v]
 			}
-			prepend(cc.name, &def.FootstepSnd.Name)
-			prepend(cc.name, &def.DiggingSnd.Name)
-			prepend(cc.name, &def.DugSnd.Name)
-			prepend(cc.name, &def.DigPredict)
+			prepend(cc.mediaPool, &def.FootstepSnd.Name)
+			prepend(cc.mediaPool, &def.DiggingSnd.Name)
+			prepend(cc.mediaPool, &def.DugSnd.Name)
+			prepend(cc.mediaPool, &def.DigPredict)
 			nodeDefs = append(nodeDefs, def)
 
 			param0++
@@ -466,7 +468,7 @@ func muxMedia(conns []*contentConn) []mediaFile {
 	for _, cc := range conns {
 		<-cc.done()
 		for _, f := range cc.media {
-			prepend(cc.name, &f.name)
+			prepend(cc.mediaPool, &f.name)
 			media = append(media, f)
 		}
 	}
@@ -494,27 +496,37 @@ func muxRemotes(conns []*contentConn) []string {
 
 func muxContent(userName string) (itemDefs []mt.ItemDef, aliases []struct{ Alias, Orig string }, nodeDefs []mt.NodeDef, p0Map param0Map, p0SrvMap param0SrvMap, media []mediaFile, remotes []string, err error) {
 	var conns []*contentConn
-	for _, srv := range Conf().Servers {
+
+PoolLoop:
+	for _, pool := range PoolServers() {
 		var addr *net.UDPAddr
-		addr, err = net.ResolveUDPAddr("udp", srv.Addr)
-		if err != nil {
-			return
+
+		for _, srv := range pool {
+			addr, err = net.ResolveUDPAddr("udp", srv.Addr)
+			if err != nil {
+				continue
+			}
+
+			var conn *net.UDPConn
+			conn, err = net.DialUDP("udp", nil, addr)
+			if err != nil {
+				continue
+			}
+
+			var cc *contentConn
+			cc, err = connectContent(conn, srv.Name, userName, srv.MediaPool)
+			if err != nil {
+				continue
+			}
+			defer cc.Close()
+
+			conns = append(conns, cc)
+			continue PoolLoop
 		}
 
-		var conn *net.UDPConn
-		conn, err = net.DialUDP("udp", nil, addr)
-		if err != nil {
-			return
-		}
-
-		var cc *contentConn
-		cc, err = connectContent(conn, srv.Name, userName)
-		if err != nil {
-			return
-		}
-		defer cc.Close()
-
-		conns = append(conns, cc)
+		// There's a pool with no reachable servers.
+		// We can't safely let clients join.
+		return
 	}
 
 	itemDefs, aliases = muxItemDefs(conns)
@@ -594,7 +606,7 @@ func prependTexture(prep string, t *mt.Texture) {
 func (sc *ServerConn) prependInv(inv mt.Inv) {
 	for k, l := range inv {
 		for i := range l.Stacks {
-			prepend(sc.name, &inv[k].InvList.Stacks[i].Name)
+			prepend(sc.mediaPool, &inv[k].InvList.Stacks[i].Name)
 		}
 	}
 }
@@ -603,28 +615,28 @@ func (sc *ServerConn) prependHUD(t mt.HUDType, cmdIface mt.ToCltCmd) {
 	pa := func(cmd *mt.ToCltAddHUD) {
 		switch t {
 		case mt.StatbarHUD:
-			prepend(sc.name, &cmd.Text2)
+			prepend(sc.mediaPool, &cmd.Text2)
 			fallthrough
 		case mt.ImgHUD:
 			fallthrough
 		case mt.ImgWaypointHUD:
 			fallthrough
 		case mt.ImgWaypointHUD + 1:
-			prepend(sc.name, &cmd.Text)
+			prepend(sc.mediaPool, &cmd.Text)
 		}
 	}
 
 	pc := func(cmd *mt.ToCltChangeHUD) {
 		switch t {
 		case mt.StatbarHUD:
-			prepend(sc.name, &cmd.Text2)
+			prepend(sc.mediaPool, &cmd.Text2)
 			fallthrough
 		case mt.ImgHUD:
 			fallthrough
 		case mt.ImgWaypointHUD:
 			fallthrough
 		case mt.ImgWaypointHUD + 1:
-			prepend(sc.name, &cmd.Text)
+			prepend(sc.mediaPool, &cmd.Text)
 		}
 	}
 

doc/config.md

@@ -117,6 +117,15 @@ Default: ""
 Description: The network address and port of an internal server.
 ```
 
+> `Server.MediaPool`
+```
+Type: string
+Default: Server.Name
+Description: The media pool this server will be part of.
+See [media_pools.md](https://github.com/HimbeerserverDE/mt-multiserver-proxy/blob/main/doc/media_pools.md)
+for more information.
+```
+
 > `Server.Fallback`
 ```
 Type: []string

doc/media_pools.md

@@ -0,0 +1,53 @@
+# Media Pools
+
+All servers must be part of a media pool. By default the name of the server
+is used.
+
+## Background
+When the proxy sends any content-related packets to the client,
+it prefixes any content names such as node names or media file names
+with the media pool of the current server and an underscore.
+The purpose of this is to allow servers to have different media
+with the same name and to avoid some other multiplexing issues.
+
+## When to use media pools?
+In general, custom media pools are not required.
+There are reasons to use them:
+- reducing memory and storage usage on the client
+- dynamically adding servers
+
+### Reducing RAM and disk usage
+The client has to store all media it receives in memory and in its cache.
+Minetest doesn't do this very efficiently: Identical files with different
+names will not share memory, a copy will be made. Even if they did share
+memory the references would still consume memory themselves but that would
+probably be negligable.
+
+This may not look like a big issue but it is. Many machines, especially
+phones, still only have 4 GB of RAM or even less. It's quite easy to
+exceed this limit even with lightweight or basic subgames. This will make
+devices that don't have enough memory unable to connect. The game will crash
+while downloading media.
+
+The unnecessarily redundant caching will fill the permanent storage with
+unneeded files too. This isn't as big of a problem as the cache isn't
+(or at least shouldn't) be required for the engine to work. However
+inexperienced players are going to wonder where their disk space is going.
+
+### Dynamic servers
+These are a whole other mess but all you need to know is that they won't work
+without media pools. The reason is that connected clients can't get the new
+content without reconnecting due to engine restrictions. Media pools are
+pushed to the client when it connects. This requires the first server of the
+media pool to be reachable. This means you can make a dummy server for the
+media and prevent players from connecting to it, or just use a hub server
+as the media master.
+
+## How to use media pools?
+Simply specify the name of the media pool you'd like the server to be part of
+in the MediaPool field of the server definition. All server you do this for
+will be part of the pool. Alternatively you can specify the name of another
+server if that server doesn't have a custom media pool set or if it's the same
+as its name. This will result in the servers being in a media pool that has
+the same name as that server. You can use it to your advantage when creating
+and naming dummy servers.

formspec.go

@@ -13,7 +13,7 @@ func (sc *ServerConn) prependFormspec(fs *string) {
 
 	for i, sub := range subs {
 		if textureName.MatchString(sub) && !strings.Contains(sub, " ") {
-			prepend(sc.name, &subs[i])
+			prepend(sc.mediaPool, &subs[i])
 		}
 	}
 

process.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net"
 	"strings"
+	"time"
 
 	"github.com/HimbeerserverDE/srp"
 	"github.com/anon55555/mt"
@@ -441,14 +442,28 @@ func (cc *ClientConn) process(pkt mt.Pkt) {
 			srv.swapAOID(&cmd.Pointed.(*mt.PointedAO).ID)
 		}
 	case *mt.ToSrvChatMsg:
-		go func() {
+		done := make(chan struct{})
+
+		go func(done chan<- struct{}) {
+
 			result, isCmd := onChatMsg(cc, cmd)
 			if !isCmd {
 				forward(pkt)
 			} else if result != "" {
 				cc.SendChatMsg(result)
 			}
-		}()
+
+      close(done)
+		}(done)
+
+		go func(done <-chan struct{}) {
+			select {
+			case <-done:
+			case <-time.After(ChatCmdTimeout):
+				cmdName := strings.Split(cmd.Msg, " ")[0]
+				cc.SendChatMsg("Command", cmdName, "is taking suspiciously long to execute.")
+			}
+		}(done)
 
 		return
 	}
@@ -616,7 +631,7 @@ func (sc *ServerConn) process(pkt mt.Pkt) {
 
 		handStack := mt.Stack{
 			Item: mt.Item{
-				Name: sc.name + "_hand",
+				Name: sc.mediaPool + "_hand",
 			},
 			Count: 1,
 		}
@@ -734,7 +749,7 @@ func (sc *ServerConn) process(pkt mt.Pkt) {
 			break
 		}
 
-		prepend(sc.name, &cmd.Filename)
+		prepend(sc.mediaPool, &cmd.Filename)
 		if cmd.ShouldCache {
 			cacheMedia(mediaFile{
 				name:       cmd.Filename,
@@ -744,17 +759,17 @@ func (sc *ServerConn) process(pkt mt.Pkt) {
 		}
 	case *mt.ToCltSkyParams:
 		for i := range cmd.Textures {
-			prependTexture(sc.name, &cmd.Textures[i])
+			prependTexture(sc.mediaPool, &cmd.Textures[i])
 		}
 	case *mt.ToCltSunParams:
-		prependTexture(sc.name, &cmd.Texture)
-		prependTexture(sc.name, &cmd.ToneMap)
-		prependTexture(sc.name, &cmd.Rise)
+		prependTexture(sc.mediaPool, &cmd.Texture)
+		prependTexture(sc.mediaPool, &cmd.ToneMap)
+		prependTexture(sc.mediaPool, &cmd.Rise)
 	case *mt.ToCltMoonParams:
-		prependTexture(sc.name, &cmd.Texture)
-		prependTexture(sc.name, &cmd.ToneMap)
+		prependTexture(sc.mediaPool, &cmd.Texture)
+		prependTexture(sc.mediaPool, &cmd.ToneMap)
 	case *mt.ToCltSetHotbarParam:
-		prependTexture(sc.name, &cmd.Img)
+		prependTexture(sc.mediaPool, &cmd.Img)
 	case *mt.ToCltUpdatePlayerList:
 		if !clt.playerListInit {
 			clt.playerListInit = true
@@ -772,7 +787,7 @@ func (sc *ServerConn) process(pkt mt.Pkt) {
 			}
 		}
 	case *mt.ToCltSpawnParticle:
-		prependTexture(sc.name, &cmd.Texture)
+		prependTexture(sc.mediaPool, &cmd.Texture)
 		sc.globalParam0(&cmd.NodeParam0)
 	case *mt.ToCltBlkData:
 		for i := range cmd.Blk.Param0 {
@@ -791,14 +806,14 @@ func (sc *ServerConn) process(pkt mt.Pkt) {
 	case *mt.ToCltAddNode:
 		sc.globalParam0(&cmd.Node.Param0)
 	case *mt.ToCltAddParticleSpawner:
-		prependTexture(sc.name, &cmd.Texture)
+		prependTexture(sc.mediaPool, &cmd.Texture)
 		sc.swapAOID(&cmd.AttachedAOID)
 		sc.globalParam0(&cmd.NodeParam0)
 		sc.particleSpawners[cmd.ID] = struct{}{}
 	case *mt.ToCltDelParticleSpawner:
 		delete(sc.particleSpawners, cmd.ID)
 	case *mt.ToCltPlaySound:
-		prepend(sc.name, &cmd.Name)
+		prepend(sc.mediaPool, &cmd.Name)
 		sc.swapAOID(&cmd.SrcAOID)
 		if cmd.Loop {
 			sc.sounds[cmd.ID] = struct{}{}
@@ -823,7 +838,7 @@ func (sc *ServerConn) process(pkt mt.Pkt) {
 		sc.prependFormspec(&cmd.Formspec)
 	case *mt.ToCltMinimapModes:
 		for i := range cmd.Modes {
-			prependTexture(sc.name, &cmd.Modes[i].Texture)
+			prependTexture(sc.mediaPool, &cmd.Modes[i].Texture)
 		}
 	case *mt.ToCltNodeMetasChanged:
 		for k := range cmd.Changed {

proxy.go

@@ -16,7 +16,7 @@ import (
 const (
 	latestSerializeVer = 28
 	latestProtoVer     = 39
-	versionString      = "5.4.1-dev-b2596eda3"
+	versionString      = "5.4.1"
 	maxPlayerNameLen   = 20
 	bytesPerMediaBunch = 5000
 )

server_conn.go

@@ -29,6 +29,8 @@ type ServerConn struct {
 		salt, srpA, a, srpK []byte
 	}
 
+	mediaPool string
+
 	inv          mt.Inv
 	detachedInvs []string