Parse the BYE reason. (#471)

* Parse the BYE reason.

* Fix REFER test.

* Only populate error for non-normal bye reasons.

Author: dennwc

pkg/sip/inbound.go

@@ -23,6 +23,7 @@ import (
 	"math"
 	"net/netip"
 	"slices"
+	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -464,9 +465,25 @@ func (s *Server) onBye(log *slog.Logger, req *sip.Request, tx sip.ServerTransact
 	c := s.activeCalls[tag]
 	s.cmu.RUnlock()
 	if c != nil {
-		c.log.Infow("BYE from remote")
 		c.cc.AcceptBye(req, tx)
-		_ = c.Close()
+		var (
+			reason    ReasonHeader
+			rawReason string
+		)
+		if h := req.GetHeader("Reason"); h != nil {
+			rawReason = h.Value()
+			reason, err = ParseReasonHeader(rawReason)
+			if err != nil {
+				c.log.Warnw("cannot parse reason header", err, "reason-raw", rawReason)
+			}
+		}
+		c.log.Infow("BYE from remote",
+			"reason-type", reason.Type,
+			"reason-cause", reason.Cause,
+			"reason-text", reason.Text,
+			"reason-raw", rawReason,
+		)
+		c.Bye(reason)
 		return
 	}
 	ok := false
@@ -540,6 +557,7 @@ type inboundCall struct {
 	attrsToHdr  map[string]string
 	ctx         context.Context
 	cancel      func()
+	closeReason atomic.Pointer[ReasonHeader]
 	call        *rpc.SIPCall
 	media       *MediaPort
 	dtmf        chan dtmf.Event // buffered
@@ -1062,17 +1080,41 @@ func (c *inboundCall) closeWithNoACK() {
 }
 
 func (c *inboundCall) closeWithCancelled() {
-	c.state.DeferUpdate(func(info *livekit.SIPCallInfo) {
-		info.DisconnectReason = livekit.DisconnectReason_CLIENT_INITIATED
-	})
-	c.close(false, CallHangup, "cancelled")
+	var reason ReasonHeader
+	if p := c.closeReason.Load(); p != nil {
+		reason = *p
+	}
+	c.closeWithReason(CallHangup, "cancelled", reason)
 }
 
 func (c *inboundCall) closeWithHangup() {
+	var reason ReasonHeader
+	if p := c.closeReason.Load(); p != nil {
+		reason = *p
+	}
+	c.closeWithReason(CallHangup, "hangup", reason)
+}
+
+func (c *inboundCall) closeWithReason(status CallStatus, reasonName string, reason ReasonHeader) {
 	c.state.DeferUpdate(func(info *livekit.SIPCallInfo) {
 		info.DisconnectReason = livekit.DisconnectReason_CLIENT_INITIATED
+		if info.Error == "" {
+			if !reason.IsNormal() {
+				info.Error = reason.String()
+			}
+		}
 	})
-	c.close(false, CallHangup, "hangup")
+	if reason.Type != "" {
+		if !reason.IsNormal() {
+			reasonName = fmt.Sprintf("bye-%s-%d", strings.ToLower(reason.Type), reason.Cause)
+		}
+	}
+	c.close(false, status, reasonName)
+}
+
+func (c *inboundCall) Bye(reason ReasonHeader) {
+	c.closeReason.Store(&reason)
+	_ = c.Close()
 }
 
 func (c *inboundCall) Close() error {

pkg/sip/protocol.go

@@ -456,3 +456,59 @@ func ToSIPUri(ip string, u sip.Uri) *livekit.SIPUri {
 	}
 	return url
 }
+
+type ReasonHeader struct {
+	Type  string
+	Cause int
+	Text  string
+}
+
+func (r ReasonHeader) IsZero() bool {
+	return r == ReasonHeader{}
+}
+
+func (r ReasonHeader) IsNormal() bool {
+	if r.IsZero() {
+		return true // assume there's no specific reason
+	}
+	switch r.Type {
+	case "Q.850":
+		switch r.Cause {
+		case 16: // Normal call clearing
+			return true
+		}
+	}
+	return false
+}
+
+func (r ReasonHeader) String() string {
+	if r.IsZero() {
+		return "<none>"
+	}
+	return fmt.Sprintf("%s-%d: %s", r.Type, r.Cause, r.Text)
+}
+
+func ParseReasonHeader(header string) (ReasonHeader, error) {
+	list := strings.Split(header, ";")
+	if len(list) < 2 {
+		return ReasonHeader{}, errors.New("no fields in the reason")
+	}
+	typ := strings.TrimSpace(list[0])
+	r := ReasonHeader{Type: typ}
+	for _, line := range list[1:] {
+		line = strings.TrimSpace(line)
+		i := strings.Index(line, "=")
+		if i < 0 {
+			continue
+		}
+		key := strings.TrimSpace(line[:i])
+		val := strings.TrimSpace(line[i+1:])
+		switch key {
+		case "cause":
+			r.Cause, _ = strconv.Atoi(val)
+		case "text":
+			r.Text, _ = strconv.Unquote(val)
+		}
+	}
+	return r, nil
+}

pkg/sip/protocol_test.go

@@ -72,3 +72,37 @@ func TestHandleNotify(t *testing.T) {
 	m, c, s, r, err = handleNotify(req)
 	require.Error(t, err)
 }
+
+func TestParseReason(t *testing.T) {
+	cases := []struct {
+		Name   string
+		Header string
+		Reason ReasonHeader
+	}{
+		{
+			Name:   "SIP",
+			Header: `SIP ;cause=200 ;text="Call completed elsewhere"`,
+			Reason: ReasonHeader{
+				Type:  "SIP",
+				Cause: 200,
+				Text:  "Call completed elsewhere",
+			},
+		},
+		{
+			Name:   "Q.850",
+			Header: `Q.850;cause=16;text="Terminated"`,
+			Reason: ReasonHeader{
+				Type:  "Q.850",
+				Cause: 16,
+				Text:  "Terminated",
+			},
+		},
+	}
+	for _, c := range cases {
+		t.Run(c.Name, func(t *testing.T) {
+			r, err := ParseReasonHeader(c.Header)
+			require.NoError(t, err)
+			require.Equal(t, c.Reason, r)
+		})
+	}
+}

test/integration/sip_test.go

@@ -421,7 +421,7 @@ func TestSIPJoinOpenRoom(t *testing.T) {
 
 	require.Equal(t, sipgo.REFER, referRequest.Method)
 	transferTo := referRequest.GetHeader("Refer-To")
-	require.Equal(t, "tel:"+transferNumber, transferTo.Value())
+	require.Equal(t, "<tel:"+transferNumber+">", transferTo.Value())
 
 	time.Sleep(notifyIntervalDelay)
 	err = cli.SendNotify(referRequest, "SIP/2.0 100 Trying")
@@ -577,7 +577,7 @@ func TestSIPJoinPinRoom(t *testing.T) {
 
 	require.Equal(t, sipgo.REFER, referRequest.Method)
 	transferTo := referRequest.GetHeader("Refer-To")
-	require.Equal(t, "tel:"+transferNumber, transferTo.Value())
+	require.Equal(t, "<tel:"+transferNumber+">", transferTo.Value())
 
 	time.Sleep(notifyIntervalDelay)
 	err = cli.SendNotify(referRequest, "SIP/2.0 403 Fobidden")