Make connection multiplexing configurable

config/config.go

@@ -58,6 +58,8 @@ const (
 
 	OptionTypeAntiReplayMaxSize
 
+	OptionTypeMultiplexPerConnection
+
 	OptionTypeSecret
 	OptionTypeAdtag
 )
@@ -80,6 +82,8 @@ type Config struct {
 
 	AntiReplayMaxSize int64 `json:"anti_replay_max_size"`
 
+	MultiplexPerConnection int `json:"multiplex_per_connection"`
+
 	Debug            bool             `json:"debug"`
 	Verbose          bool             `json:"verbose"`
 	StatsdTagsFormat statsd.TagFormat `json:"statsd_tags_format"`
@@ -149,6 +153,8 @@ func Init(options ...Opt) error { // nolint: gocyclo, funlen
 			C.CloakPort = int(opt.Value.(uint16))
 		case OptionTypeAntiReplayMaxSize:
 			C.AntiReplayMaxSize = int64(opt.Value.(units.Base2Bytes))
+		case OptionTypeMultiplexPerConnection:
+			C.MultiplexPerConnection = int(opt.Value.(uint))
 		case OptionTypeSecret:
 			C.Secret = opt.Value.([]byte)
 		case OptionTypeAdtag:
@@ -173,6 +179,10 @@ func Init(options ...Opt) error { // nolint: gocyclo, funlen
 		return errors.New("incorrect secret")
 	}
 
+	if C.MultiplexPerConnection == 0 {
+		return errors.New("cannot use 0 clients per connection for multiplexing")
+	}
+
 	if C.CloakHost != "" {
 		addrs, err := net.LookupHost(C.CloakHost)
 		if err != nil {

hub/connection_list.go

@@ -3,9 +3,9 @@ package hub
 import (
 	"fmt"
 	"sort"
-)
 
-const connectionListMaxClientsPerConnection = 2
+	"github.com/9seconds/mtg/config"
+)
 
 type connectionList struct {
 	connections []*connection
@@ -16,7 +16,7 @@ func (c *connectionList) Get(conn *ProxyConn) (*connection, error) {
 		c.gc()
 	}
 
-	if len(c.connections) > 0 && c.connections[0].Len() < connectionListMaxClientsPerConnection {
+	if len(c.connections) > 0 && c.connections[0].Len() < config.C.MultiplexPerConnection {
 		if err := c.connections[0].Attach(conn); err == nil {
 			return c.connections[0], nil
 		}

main.go

@@ -108,6 +108,11 @@ var (
 		Envar("MTG_ANTIREPLAY_MAXSIZE").
 		Default("128MB").
 		Bytes()
+	runMultiplexPerConnection = runCommand.Flag("multiplex-per-connection",
+		"How many clients can share a single connection to Telegram.").
+		Envar("MTG_MULTIPLEX_PERCONNECTION").
+		Default("50").
+		Uint()
 	runSecret = runCommand.Arg("secret", "Secret of this proxy.").Required().HexBytes()
 	runAdtag  = runCommand.Arg("adtag", "ADTag of the proxy.").HexBytes()
 )
@@ -141,6 +146,7 @@ func main() {
 			config.Opt{Option: config.OptionTypeReadBufferSize, Value: *runReadBufferSize},
 			config.Opt{Option: config.OptionTypeCloakPort, Value: *runTLSCloakPort},
 			config.Opt{Option: config.OptionTypeAntiReplayMaxSize, Value: *runAntiReplayMaxSize},
+			config.Opt{Option: config.OptionTypeMultiplexPerConnection, Value: *runMultiplexPerConnection},
 			config.Opt{Option: config.OptionTypeSecret, Value: *runSecret},
 			config.Opt{Option: config.OptionTypeAdtag, Value: *runAdtag},
 		)