Merge pull request #82 from ev2-1/main

Issue #4

cmd/mt-multiserver-proxy/.gitignore

@@ -0,0 +1,4 @@
+config.json
+cache/
+*.log
+auth/

cmd/mt-multiserver-proxy/build.sh

@@ -0,0 +1,4 @@
+cd ../..
+go build
+cd cmd/mt-multiserver-proxy
+go build

config.go

@@ -33,10 +33,12 @@ type Config struct {
 	TelnetAddr    string
 	BindAddr      string
 	Servers       []struct {
-		Name string
-		Addr string
+		Name      string
+		Addr      string
+		Fallbacks []string
 	}
 	ForceDefaultSrv bool
+	FallbackServers []string
 	CSMRF           struct {
 		NoCSMs          bool
 		ChatMsgs        bool
@@ -75,6 +77,38 @@ func Conf() Config {
 	return config
 }
 
+// FallbackServers returns a slice of server names that
+// a server can fall back to.
+func FallbackServers(server string) []string {
+	configMu.RLock()
+	defer configMu.RUnlock()
+
+	fallbacks := make([]string, 0)
+
+	conf := Conf()
+	
+	// find server
+	for _, srv := range conf.Servers {
+		if srv.Name == server {
+			fallbacks = append(fallbacks, srv.Fallbacks...)
+			break
+		}
+	}
+
+	// global fallbacks
+	if len(conf.FallbackServers) == 0 {
+		if len(conf.Servers) == 0 {
+			return fallbacks
+		}
+		
+		return append(fallbacks, conf.Servers[0].Name)
+	} else {
+		return append(fallbacks, conf.FallbackServers...)
+	}
+
+	return fallbacks
+}
+
 // LoadConfig attempts to parse the configuration file.
 // It leaves the config unchanged if there is an error
 // and returns the error.
@@ -90,6 +124,7 @@ func LoadConfig() error {
 	config.AuthBackend = defaultAuthBackend
 	config.TelnetAddr = defaultTelnetAddr
 	config.BindAddr = defaultBindAddr
+	config.FallbackServers = make([]string, 0)
 	config.Groups = make(map[string][]string)
 	config.UserGroups = make(map[string]string)
 	config.List.Interval = defaultListInterval

doc/config.md

@@ -117,6 +117,13 @@ Default: ""
 Description: The network address and port of an internal server.
 ```
 
+> `Server.Fallback`
+```
+Type: []string
+Default: []string{}
+Description: Servers that clients get sent to when server stops or crashes (in order).
+```
+
 > `ForceDefaultSrv`
 ```
 Type: bool
@@ -181,6 +188,13 @@ Default: 0
 Description: The maximum distance from which CSMs can read the map.
 ```
 
+> `FallbackServers`
+```
+Type: []string
+Default: []string{}
+Description: General Fallback servers if server stopps and clients are connected.
+```
+
 > `DropCSMRF`
 ```
 Type: bool

process.go

@@ -538,6 +538,19 @@ func (sc *ServerConn) process(pkt mt.Pkt) {
 		return
 	case *mt.ToCltKick:
 		sc.Log("<-", "deny access", cmd)
+		
+		if cmd.Reason == mt.Shutdown || cmd.Reason == mt.Crash || cmd.Reason == mt.SrvErr || cmd.Reason == cmd.TooManyClts || cmd.Reason == cmd.UnsupportedVer {
+			clt.SendChatMsg(cmd.String())
+			for _, srvName := range FallbackServers(sc.name) {
+				if err := clt.Hop(); err != nil {
+					clt.Log("<-", err)
+					break
+				}
+			}
+			
+			return
+		}
+
 		ack, _ := clt.SendCmd(cmd)
 
 		select {