From 4b171b849f50b333956ebd48b5b3afd6359c3c45 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Torjus=20H=C3=A5kestad?= <torjus@usit.uio.no>
Date: Tue, 5 Dec 2023 01:25:17 +0100
Subject: [PATCH] Make ephemeral udp ports configurable

---
 main.go          |  2 ++
 ministream.toml  | 13 ++++++++++++-
 server/config.go | 30 ++++++++++++++++++++++++++++--
 server/server.go |  2 +-
 server/stream.go | 16 ++++++++++++----
 5 files changed, 55 insertions(+), 8 deletions(-)

diff --git a/main.go b/main.go
index 04fd1f9..654bb34 100644
--- a/main.go
+++ b/main.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"log/slog"
 	"net/http"
 	"os"
 
@@ -33,6 +34,7 @@ func main() {
 
 					srv := server.NewServer(cfg)
 					srv.Addr = cfg.HTTP.ListenAddr
+					slog.Info("Starting HTTP-server", "addr", srv.Addr, "cfg", cfg)
 					if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
 						return err
 					}
diff --git a/ministream.toml b/ministream.toml
index 80b7322..798956c 100644
--- a/ministream.toml
+++ b/ministream.toml
@@ -7,4 +7,15 @@ SiteName = "stream.example.org"
 # HTTPListenAddr is which port the HTTP server will listen on.
 # Default: ":8080"
 # Env: MINISTREAM_HTTP_LISTENADDR
-HTTPListenAddr = ":8080"
+ListenAddr = ":8080"
+
+[WebRTC]
+# UDPMin is the minimum used for ephemeral ports.
+# Default: 50000
+# Env: MINISTREAM_WEBRTC_UDPMIN
+UDPMin = 50000
+
+# UDPMax is the maximum used for ephemeral ports.
+# Default: 50050
+# Env: MINISTREAM_WEBRTC_UDPMAX
+UDPMAX = 50050
diff --git a/server/config.go b/server/config.go
index a10c7c6..017f4c9 100644
--- a/server/config.go
+++ b/server/config.go
@@ -3,25 +3,36 @@ package server
 import (
 	"io"
 	"os"
+	"strconv"
 
 	"github.com/pelletier/go-toml/v2"
 )
 
 type Config struct {
-	SiteName string     `toml:"siteName"`
-	HTTP     ConfigHTTP `toml:"http"`
+	SiteName string       `toml:"siteName"`
+	HTTP     ConfigHTTP   `toml:"http"`
+	WebRTC   ConfigWebRTC `toml:"WebRTC"`
 }
 
 type ConfigHTTP struct {
 	ListenAddr string `json:"ListenAddr" toml:"ListenAddr"`
 }
 
+type ConfigWebRTC struct {
+	UDPMin int `toml:"UDPMin"`
+	UDPMax int `toml:"UDPMax"`
+}
+
 func DefaultConfig() *Config {
 	return &Config{
 		SiteName: "ministream",
 		HTTP: ConfigHTTP{
 			ListenAddr: ":8080",
 		},
+		WebRTC: ConfigWebRTC{
+			UDPMin: 50000,
+			UDPMax: 50050,
+		},
 	}
 }
 
@@ -33,6 +44,21 @@ func (c *Config) OverrideFromEnv() {
 	if httpAddr, ok := os.LookupEnv("MINISTREAM_HTTP_LISTENADDR"); ok {
 		c.HTTP.ListenAddr = httpAddr
 	}
+
+	if value, ok := os.LookupEnv("MINISTREAM_WEBRTC_UDPMIN"); ok {
+		min, err := strconv.Atoi(value)
+		if err != nil {
+			panic("MINISTREAM_WEBRTC_UDPMIN is invalid")
+		}
+		c.WebRTC.UDPMin = min
+	}
+	if value, ok := os.LookupEnv("MINISTREAM_WEBRTC_UDPMAX"); ok {
+		max, err := strconv.Atoi(value)
+		if err != nil {
+			panic("MINISTREAM_WEBRTC_UDPMAX is invalid")
+		}
+		c.WebRTC.UDPMin = max
+	}
 }
 
 func ConfigFromReader(r io.Reader) (*Config, error) {
diff --git a/server/server.go b/server/server.go
index f1608fe..653af4e 100644
--- a/server/server.go
+++ b/server/server.go
@@ -26,7 +26,7 @@ type Server struct {
 
 func NewServer(config *Config) *Server {
 	srv := &Server{
-		streams: NewStreamStore(),
+		streams: NewStreamStore(config),
 		config:  config,
 	}
 
diff --git a/server/stream.go b/server/stream.go
index 5a2957a..6337791 100644
--- a/server/stream.go
+++ b/server/stream.go
@@ -19,20 +19,24 @@ import (
 var ErrNoSuchStream error = fmt.Errorf("no such stream")
 
 type StreamStore struct {
-	Streams      map[string]*Stream
+	Streams map[string]*Stream
+
+	config       *Config
 	webRTCConfig webrtc.Configuration
 	mu           sync.Mutex
 }
 
-func NewStreamStore() *StreamStore {
+func NewStreamStore(config *Config) *StreamStore {
 	s := &StreamStore{
 		Streams: make(map[string]*Stream),
+		config:  config,
 	}
 
 	return s
 }
 
 type Stream struct {
+	store                 *StreamStore
 	peerConnection        *webrtc.PeerConnection
 	peerConnectionStats   map[string]*stats.Stats
 	peerConnectionStatsMu sync.Mutex
@@ -96,7 +100,10 @@ func (s *Stream) AddListener(sd *webrtc.SessionDescription) (*webrtc.SessionDesc
 	//i.Add(statsInterceptorFactory)
 
 	se := webrtc.SettingEngine{}
-	_ = se.SetEphemeralUDPPortRange(50000, 50050)
+	_ = se.SetEphemeralUDPPortRange(
+		uint16(s.store.config.WebRTC.UDPMin),
+		uint16(s.store.config.WebRTC.UDPMax),
+	)
 
 	webRTCConfig := webrtc.Configuration{
 		ICEServers: []webrtc.ICEServer{
@@ -179,6 +186,7 @@ func (s *StreamStore) Add(streamKey string, sd *webrtc.SessionDescription) (*web
 
 	go func() {
 		stream := &Stream{
+			store:               s,
 			lastUpdate:          time.Now(),
 			peerConnectionStats: make(map[string]*stats.Stats),
 		}
@@ -226,7 +234,7 @@ func (s *StreamStore) Add(streamKey string, sd *webrtc.SessionDescription) (*web
 			},
 		}
 		se := webrtc.SettingEngine{}
-		_ = se.SetEphemeralUDPPortRange(50000, 50050)
+		_ = se.SetEphemeralUDPPortRange(uint16(s.config.WebRTC.UDPMin), uint16(s.config.WebRTC.UDPMax))
 
 		// se.BufferFactory = func(packetType packetio.BufferPacketType, ssrc uint32) io.ReadWriteCloser {
 		// 	buf := packetio.NewBuffer()