Add NAT1To1IP and UseExternalIP to config

Gives user more control over what IP appears in Offer/Answer
livekit · Dec 3, 2023 · 38500e6 · 38500e6
1 parent 3fff27b
commit 38500e6
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Showing 6 changed files with 81 additions and 19 deletions.
diff --git a/pkg/config/config.go b/pkg/config/config.go
@@ -15,6 +15,7 @@
 package config
 
 import (
+	"fmt"
 	"os"
 
 	"github.com/sirupsen/logrus"
@@ -49,6 +50,9 @@ type Config struct {
 	RTPPort    rtcconfig.PortRange `yaml:"rtp_port"`
 	Logging    logger.Config       `yaml:"logging"`
 
+	UseExternalIP bool   `yaml:"use_external_ip"`
+	NAT1To1IP     string `yaml:"nat_1_to_1_ip"`
+
 	// internal
 	ServiceName string `yaml:"-"`
 	NodeID      string // Do not provide, will be overwritten
@@ -91,6 +95,10 @@ func (conf *Config) Init() error {
 		return err
 	}
 
+	if conf.UseExternalIP && conf.NAT1To1IP != "" {
+		return fmt.Errorf("use_external_ip and nat_1_to_1_ip can not both be set")
+	}
+
 	return nil
 }
 

diff --git a/pkg/sip/client.go b/pkg/sip/client.go
@@ -30,8 +30,8 @@ import (
 type Client struct {
 	conf *config.Config
 
-	sipCli   *sipgo.Client
-	publicIp string
+	sipCli      *sipgo.Client
+	signalingIp string
 
 	cmu         sync.RWMutex
 	activeCalls map[string]*outboundCall
@@ -40,13 +40,25 @@ type Client struct {
 func NewClient(conf *config.Config) *Client {
 	c := &Client{
 		conf:        conf,
-		publicIp:    getPublicIP(),
 		activeCalls: make(map[string]*outboundCall),
 	}
 	return c
 }
 
 func (c *Client) Start(agent *sipgo.UserAgent) error {
+	var err error
+	if c.conf.UseExternalIP {
+		if c.signalingIp, err = getPublicIP(); err != nil {
+			return err
+		}
+	} else if c.conf.NAT1To1IP != "" {
+		c.signalingIp = c.conf.NAT1To1IP
+	} else {
+		if c.signalingIp, err = getLocalIP(); err != nil {
+			return err
+		}
+	}
+
 	if agent == nil {
 		ua, err := sipgo.NewUA(
 			sipgo.WithUserAgent(UserAgent),
@@ -56,8 +68,7 @@ func (c *Client) Start(agent *sipgo.UserAgent) error {
 		}
 		agent = ua
 	}
-	var err error
-	c.sipCli, err = sipgo.NewClient(agent, sipgo.WithClientHostname(c.publicIp))
+	c.sipCli, err = sipgo.NewClient(agent, sipgo.WithClientHostname(c.signalingIp))
 	if err != nil {
 		return err
 	}

diff --git a/pkg/sip/config.go b/pkg/sip/config.go
@@ -16,32 +16,63 @@ package sip
 
 import (
 	"encoding/json"
+	"fmt"
 	"io"
+	"net"
 	"net/http"
 )
 
-func getPublicIP() string {
+func getPublicIP() (string, error) {
 	req, err := http.Get("http://ip-api.com/json/")
 	if err != nil {
-		panic(err)
+		return "", err
 	}
 	defer req.Body.Close()
 
 	body, err := io.ReadAll(req.Body)
 	if err != nil {
-		panic(err)
+		return "", err
 	}
 
 	ip := struct {
 		Query string
 	}{}
 	if err = json.Unmarshal(body, &ip); err != nil {
-		panic(err)
+		return "", err
 	}
 
 	if ip.Query == "" {
-		panic("Query entry was not populated")
+		return "", fmt.Errorf("Query entry was not populated")
 	}
 
-	return ip.Query
+	return ip.Query, nil
+}
+
+func getLocalIP() (string, error) {
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		return "", err
+	}
+	for _, i := range ifaces {
+		addrs, err := i.Addrs()
+		if err != nil {
+			continue
+		}
+
+		for _, a := range addrs {
+			switch v := a.(type) {
+			case *net.IPAddr:
+				if !v.IP.IsLoopback() && v.IP.To4() != nil {
+					return v.IP.String(), nil
+				}
+			case *net.IPNet:
+				if !v.IP.IsLoopback() && v.IP.To4() != nil {
+					return v.IP.String(), nil
+				}
+			}
+
+		}
+	}
+
+	return "", fmt.Errorf("No local interface found")
 }
diff --git a/pkg/sip/inbound.go b/pkg/sip/inbound.go
@@ -170,7 +170,7 @@ func (c *inboundCall) handleInvite(req *sip.Request, tx sip.ServerTransaction) {
 	c.s.cmu.Unlock()
 
 	res := sip.NewResponseFromRequest(req, 200, "OK", answerData)
-	res.AppendHeader(&sip.ContactHeader{Address: sip.Uri{Host: c.s.publicIp, Port: c.s.conf.SIPPort}})
+	res.AppendHeader(&sip.ContactHeader{Address: sip.Uri{Host: c.s.signalingIp, Port: c.s.conf.SIPPort}})
 	res.AppendHeader(&contentTypeHeaderSDP)
 	if err = tx.Respond(res); err != nil {
 		log.Println(err)
@@ -202,7 +202,7 @@ func (c *inboundCall) runMediaConn(offerData []byte) (answerData []byte, _ error
 	s := rtp.NewMediaStreamOut[ulaw.Sample](conn, rtpPacketDur)
 	c.lkRoom.SetOutput(ulaw.Decode(s))
 
-	return sdpGenerateAnswer(offer, c.s.publicIp, conn.LocalAddr().Port)
+	return sdpGenerateAnswer(offer, c.s.signalingIp, conn.LocalAddr().Port)
 }
 
 func (c *inboundCall) pinPrompt() {

diff --git a/pkg/sip/outbound.go b/pkg/sip/outbound.go
@@ -248,7 +248,7 @@ func (c *outboundCall) stopSIP() {
 }
 
 func (c *outboundCall) sipSignal(conf sipOutboundConfig) error {
-	offer, err := sdpGenerateOffer(c.c.publicIp, c.rtpConn.LocalAddr().Port)
+	offer, err := sdpGenerateOffer(c.c.signalingIp, c.rtpConn.LocalAddr().Port)
 	if err != nil {
 		return err
 	}
@@ -271,7 +271,7 @@ func (c *outboundCall) sipAttemptInvite(offer []byte, conf sipOutboundConfig, au
 	req.SetDestination("") // FIXME: what should be here
 	req.SetBody(offer)
 	req.AppendHeader(sip.NewHeader("Content-Type", "application/sdp"))
-	req.AppendHeader(sip.NewHeader("Contact", fmt.Sprintf("<sip:livekit@%s:5060>", c.c.publicIp)))
+	req.AppendHeader(sip.NewHeader("Contact", fmt.Sprintf("<sip:livekit@%s:5060>", c.c.signalingIp)))
 	req.AppendHeader(sip.NewHeader("Allow", "INVITE, ACK, CANCEL, BYE, NOTIFY, REFER, MESSAGE, OPTIONS, INFO, SUBSCRIBE"))
 
 	if authHeader != "" {

diff --git a/pkg/sip/server.go b/pkg/sip/server.go
@@ -41,8 +41,8 @@ type (
 	AuthHandlerFunc         func(from, to, srcAddress string) (username, password string, err error)
 	DispatchRuleHandlerFunc func(callingNumber, calledNumber, srcAddress string, pin string, noPin bool) (joinRoom, identity string, requestPin, rejectInvite bool)
 	Server                  struct {
-		sipSrv   *sipgo.Server
-		publicIp string
+		sipSrv      *sipgo.Server
+		signalingIp string
 
 		inProgressInvites []*inProgressInvite
 
@@ -65,7 +65,6 @@ type (
 func NewServer(conf *config.Config) *Server {
 	s := &Server{
 		conf:              conf,
-		publicIp:          getPublicIP(),
 		activeCalls:       make(map[string]*inboundCall),
 		inProgressInvites: []*inProgressInvite{},
 	}
@@ -110,6 +109,19 @@ func logOnError(err error) {
 }
 
 func (s *Server) Start(agent *sipgo.UserAgent) error {
+	var err error
+	if s.conf.UseExternalIP {
+		if s.signalingIp, err = getPublicIP(); err != nil {
+			return err
+		}
+	} else if s.conf.NAT1To1IP != "" {
+		s.signalingIp = s.conf.NAT1To1IP
+	} else {
+		if s.signalingIp, err = getLocalIP(); err != nil {
+			return err
+		}
+	}
+
 	if agent == nil {
 		ua, err := sipgo.NewUA(
 			sipgo.WithUserAgent(UserAgent),
@@ -119,7 +131,7 @@ func (s *Server) Start(agent *sipgo.UserAgent) error {
 		}
 		agent = ua
 	}
-	var err error
+
 	s.sipSrv, err = sipgo.NewServer(agent)
 	if err != nil {
 		return err