From 5628a6038852e880c092077ac4c1671ec41c74f2 Mon Sep 17 00:00:00 2001
From: Denys Smirnov <dennwc@pm.me>
Date: Fri, 24 Nov 2023 17:22:18 +0200
Subject: [PATCH] Share SIP user agent.

---
 cmd/server/main.go  | 12 ++++++++++--
 pkg/sip/client.go   | 19 +++++++++++--------
 pkg/sip/config.go   |  9 ++++-----
 pkg/sip/inbound.go  |  2 +-
 pkg/sip/server.go   | 23 +++++++++++++----------
 test/client/main.go |  5 ++---
 6 files changed, 41 insertions(+), 29 deletions(-)

diff --git a/cmd/server/main.go b/cmd/server/main.go
index bc462d0a..14cfdf5a 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -21,6 +21,7 @@ import (
 	"os/signal"
 	"syscall"
 
+	"github.com/emiago/sipgo"
 	"github.com/urfave/cli/v2"
 
 	"github.com/livekit/protocol/logger"
@@ -84,15 +85,22 @@ func runService(c *cli.Context) error {
 	killChan := make(chan os.Signal, 1)
 	signal.Notify(killChan, syscall.SIGINT)
 
+	ua, err := sipgo.NewUA(
+		sipgo.WithUserAgent(sip.UserAgent),
+	)
+	if err != nil {
+		return err
+	}
+
 	sipCli := sip.NewClient(conf)
-	if err = sipCli.Start(); err != nil {
+	if err = sipCli.Start(ua); err != nil {
 		return err
 	}
 
 	svc := service.NewService(conf, sipCli, psrpcClient, bus)
 
 	sipSrv := sip.NewServer(conf, svc.HandleTrunkAuthentication, svc.HandleDispatchRules)
-	if err = sipSrv.Start(); err != nil {
+	if err = sipSrv.Start(ua); err != nil {
 		return err
 	}
 
diff --git a/pkg/sip/client.go b/pkg/sip/client.go
index 8f5742ae..bb6cfb84 100644
--- a/pkg/sip/client.go
+++ b/pkg/sip/client.go
@@ -46,15 +46,18 @@ func NewClient(conf *config.Config) *Client {
 	return c
 }
 
-func (c *Client) Start() error {
-	ua, err := sipgo.NewUA(
-		sipgo.WithUserAgent(userAgent),
-	)
-	if err != nil {
-		return err
+func (c *Client) Start(agent *sipgo.UserAgent) error {
+	if agent == nil {
+		ua, err := sipgo.NewUA(
+			sipgo.WithUserAgent(UserAgent),
+		)
+		if err != nil {
+			return err
+		}
+		agent = ua
 	}
-
-	c.sipCli, err = sipgo.NewClient(ua, sipgo.WithClientHostname(c.publicIp))
+	var err error
+	c.sipCli, err = sipgo.NewClient(agent, sipgo.WithClientHostname(c.publicIp))
 	if err != nil {
 		return err
 	}
diff --git a/pkg/sip/config.go b/pkg/sip/config.go
index 6a7e0439..e31becf7 100644
--- a/pkg/sip/config.go
+++ b/pkg/sip/config.go
@@ -17,31 +17,30 @@ package sip
 import (
 	"encoding/json"
 	"io"
-	"log"
 	"net/http"
 )
 
 func getPublicIP() string {
 	req, err := http.Get("http://ip-api.com/json/")
 	if err != nil {
-		log.Fatal(err)
+		panic(err)
 	}
 	defer req.Body.Close()
 
 	body, err := io.ReadAll(req.Body)
 	if err != nil {
-		log.Fatal(err)
+		panic(err)
 	}
 
 	ip := struct {
 		Query string
 	}{}
 	if err = json.Unmarshal(body, &ip); err != nil {
-		log.Fatal(err)
+		panic(err)
 	}
 
 	if ip.Query == "" {
-		log.Fatal("Query entry was not populated")
+		panic("Query entry was not populated")
 	}
 
 	return ip.Query
diff --git a/pkg/sip/inbound.go b/pkg/sip/inbound.go
index 51beabe2..72f9ef1a 100644
--- a/pkg/sip/inbound.go
+++ b/pkg/sip/inbound.go
@@ -53,7 +53,7 @@ func (s *Server) handleInviteAuth(req *sip.Request, tx sip.ServerTransaction, fr
 	h := req.GetHeader("Proxy-Authorization")
 	if h == nil {
 		inviteState.challenge = digest.Challenge{
-			Realm:     userAgent,
+			Realm:     UserAgent,
 			Nonce:     fmt.Sprintf("%d", time.Now().UnixMicro()),
 			Algorithm: "MD5",
 		}
diff --git a/pkg/sip/server.go b/pkg/sip/server.go
index 82c6c875..aac3ba73 100644
--- a/pkg/sip/server.go
+++ b/pkg/sip/server.go
@@ -29,7 +29,7 @@ import (
 )
 
 const (
-	userAgent   = "LiveKit"
+	UserAgent   = "LiveKit"
 	digestLimit = 500
 )
 
@@ -104,17 +104,20 @@ func logOnError(err error) {
 	}
 }
 
-func (s *Server) Start() error {
-	ua, err := sipgo.NewUA(
-		sipgo.WithUserAgent(userAgent),
-	)
-	if err != nil {
-		log.Fatal(err)
+func (s *Server) Start(agent *sipgo.UserAgent) error {
+	if agent == nil {
+		ua, err := sipgo.NewUA(
+			sipgo.WithUserAgent(UserAgent),
+		)
+		if err != nil {
+			return err
+		}
+		agent = ua
 	}
-
-	s.sipSrv, err = sipgo.NewServer(ua)
+	var err error
+	s.sipSrv, err = sipgo.NewServer(agent)
 	if err != nil {
-		log.Fatal(err)
+		return err
 	}
 
 	s.sipSrv.OnInvite(s.onInvite)
diff --git a/test/client/main.go b/test/client/main.go
index 0c79d217..8b6d2b93 100644
--- a/test/client/main.go
+++ b/test/client/main.go
@@ -17,7 +17,6 @@ package main
 import (
 	"flag"
 	"fmt"
-	"log"
 	"math/rand"
 	"net"
 	"os"
@@ -235,12 +234,12 @@ func main() {
 		sipgo.WithUserAgent(*from),
 	)
 	if err != nil {
-		log.Fatal(err)
+		panic(err)
 	}
 
 	sipClient, err := sipgo.NewClient(ua, sipgo.WithClientHostname(getLocalIP()))
 	if err != nil {
-		log.Fatal(err)
+		panic(err)
 	}
 
 	var (