fix: remove closing dialog server from hangup, do not override existi…

…ng contact hdr

dialog.go

@@ -10,7 +10,7 @@ import (
 
 var (
 	ErrDialogOutsideDialog   = errors.New("Call/Transaction outside dialog")
-	ErrDialogDoesNotExists   = errors.New("Call/Transaction Does Not Exist")
+	ErrDialogDoesNotExists   = errors.New("Dialog Does Not Exist")
 	ErrDialogInviteNoContact = errors.New("No Contact header")
 	ErrDialogCanceled        = errors.New("Dialog canceled")
 )

dialog_client.go

@@ -50,7 +50,8 @@ func (s *DialogClient) matchDialogRequest(req *sip.Request) (*DialogClientSessio
 }
 
 // NewDialogClient provides handle for managing UAC dialog
-// Contact hdr must be provided for correct invite
+// Contact hdr is default to be provided for correct invite. It is not used if you provided hdr as part of request,
+// but contact hdr must be present so this makes sure correct dialog is established.
 // In case handling different transports you should have multiple instances per transport
 func NewDialogClient(client *Client, contactHDR sip.ContactHeader) *DialogClient {
 	s := &DialogClient{
@@ -70,6 +71,7 @@ func (e ErrDialogResponse) Error() string {
 }
 
 // Invite sends INVITE request and creates early dialog session.
+// This is actually not yet dialog (ID is empty)
 // You need to call WaitAnswer after for establishing dialog
 // For passing custom Invite request use WriteInvite
 func (c *DialogClient) Invite(ctx context.Context, recipient sip.Uri, body []byte, headers ...sip.Header) (*DialogClientSession, error) {
@@ -87,9 +89,11 @@ func (c *DialogClient) Invite(ctx context.Context, recipient sip.Uri, body []byt
 func (c *DialogClient) WriteInvite(ctx context.Context, inviteRequest *sip.Request) (*DialogClientSession, error) {
 	cli := c.c
 
-	inviteRequest.AppendHeader(&c.contactHDR)
+	if inviteRequest.Contact() == nil {
+		// Set contact only if not exists
+		inviteRequest.AppendHeader(&c.contactHDR)
+	}
 
-	// TODO passing client transaction options is now hidden
 	tx, err := cli.TransactionRequest(ctx, inviteRequest)
 	if err != nil {
 		return nil, err
@@ -407,7 +411,7 @@ func digestTransactionRequest(ctx context.Context, client *Client, req *sip.Requ
 
 // newByeRequestUAC creates bye request from established dialog
 // https://datatracker.ietf.org/doc/html/rfc3261#section-15.1.1
-// NOTE: it does not copy Via header. This is left to transport or caller to enforce
+// NOTE: it does not copy Via header neither increases CSEQ. This is left to dialog transaction request
 func newByeRequestUAC(inviteRequest *sip.Request, inviteResponse *sip.Response, body []byte) *sip.Request {
 	recipient := &inviteRequest.Recipient
 	cont := inviteResponse.Contact()

dialog_integration_test.go

@@ -166,7 +166,7 @@ func TestIntegrationDialogBrokenUAC(t *testing.T) {
 	defer cancel()
 
 	uasContact := sip.ContactHeader{
-		Address: sip.Uri{User: "test", Host: "127.0.0.200", Port: 5099},
+		Address: sip.Uri{User: "test", Host: "127.0.0.201", Port: 5099},
 	}
 
 	dialogSrv := NewDialogServer(cli, uasContact)
@@ -207,7 +207,7 @@ func TestIntegrationDialogBrokenUAC(t *testing.T) {
 		cli, _ := NewClient(ua)
 
 		contactHDR := sip.ContactHeader{
-			Address: sip.Uri{User: "test", Host: "127.0.0.200", Port: 5088},
+			Address: sip.Uri{User: "test", Host: "127.0.0.201", Port: 5088},
 		}
 		dialogCli := NewDialogClient(cli, contactHDR)
 
@@ -227,7 +227,7 @@ func TestIntegrationDialogBrokenUAC(t *testing.T) {
 				tx.Respond(sip.NewResponseFromRequest(req, sip.StatusInternalServerError, "", nil))
 			})
 			// INVITE
-			t.Log("UAC: INVITE")
+			t.Log("UAC: INVITE ", uasContact.Address.String())
 			sess, err := dialogCli.Invite(context.TODO(), uasContact.Address, nil)
 			require.NoError(t, err)
 			defer sess.Close()
@@ -249,7 +249,7 @@ func TestIntegrationDialogBrokenUAC(t *testing.T) {
 
 		t.Run("UAS ACK Error", func(t *testing.T) {
 			// INVITE
-			t.Log("UAC: INVITE")
+			t.Log("UAC: INVITE ", uasContact.Address.String())
 			sess, err := dialogCli.Invite(context.TODO(), uasContact.Address, nil)
 			require.NoError(t, err)
 			defer sess.Close()

dialog_server.go

@@ -42,7 +42,7 @@ func (s *DialogServer) matchDialogRequest(req *sip.Request) (*DialogServerSessio
 }
 
 // NewDialogServer provides handle for managing UAS dialog
-// Contact hdr must be provided for responses
+// Contact hdr is default that is provided for responses.
 // Client is needed for termination dialog session
 // In case handling different transports you should have multiple instances per transport
 func NewDialogServer(client *Client, contactHDR sip.ContactHeader) *DialogServer {
@@ -89,7 +89,7 @@ func (s *DialogServer) ReadInvite(req *sip.Request, tx sip.ServerTransaction) (*
 		inviteTx: tx,
 		s:        s,
 	}
-
+	s.dialogs.Store(id, dtx)
 	return dtx, nil
 }
 
@@ -247,8 +247,11 @@ func (s *DialogServerSession) RespondSDP(sdp []byte) error {
 func (s *DialogServerSession) WriteResponse(res *sip.Response) error {
 	tx := s.inviteTx
 
-	// Must add contact header
-	res.AppendHeader(&s.s.contactHDR)
+	if res.Contact() == nil {
+		// Add our default contact header
+		res.AppendHeader(&s.s.contactHDR)
+	}
+
 	s.Dialog.InviteResponse = res
 
 	// Do we have cancel in meantime
@@ -285,10 +288,7 @@ func (s *DialogServerSession) WriteResponse(res *sip.Response) error {
 		return fmt.Errorf("ID do not match. Invite request has changed headers?")
 	}
 
-	// We need to make dialog present as ACK can land immediately after
-	s.s.dialogs.Store(id, s)
 	s.setState(sip.DialogStateEstablished)
-
 	if err := tx.Respond(res); err != nil {
 		// We could also not delete this as Close will handle cleanup
 		s.s.dialogs.Delete(id)
@@ -317,7 +317,6 @@ func (s *DialogServerSession) Bye(ctx context.Context) error {
 	}
 
 	// This is tricky
-	defer s.Close()              // Delete our dialog always
 	defer s.inviteTx.Terminate() // Terminates INVITE in all cases
 
 	// https://datatracker.ietf.org/doc/html/rfc3261#section-15