MT#56465 sdp_create(), set the actual media connection

In all the cases (apart PUBLISH) ensure to set the actual
media connection when creating SDP using `sdp_create()`.

A new dedicated func `sdp_out_add_media_connection()`
introduced for that.

Change-Id: I26e9b123aad95e2d335aef903d441ecc2cae2605

daemon/call_interfaces.c

@@ -3678,7 +3678,7 @@ const char *call_publish_ng(ng_buffer *ngbuf, bencode_item_t *input, bencode_ite
 	if (ret)
 		ilog(LOG_ERR, "Publish error"); // XXX close call? handle errors?
 
-	ret = sdp_create(&sdp_out, ml, &flags);
+	ret = sdp_create(&sdp_out, ml, &streams, &flags);
 	if (!ret) {
 		save_last_sdp(ml, &sdp_in, &parsed, &streams);
 		bencode_buffer_destroy_add(output->buffer, g_free, sdp_out.s);
@@ -3759,7 +3759,7 @@ const char *call_subscribe_request_ng(bencode_item_t *input, bencode_item_t *out
 			return "Failed to rewrite SDP";
 	} else {
 		/* create new SDP */
-		ret = sdp_create(&sdp_out, dest_ml, &flags);
+		ret = sdp_create(&sdp_out, dest_ml, NULL, &flags);
 	}
 
 	/* place return output SDP */

daemon/janus.c

@@ -651,7 +651,7 @@ static const char *janus_videoroom_join(struct websocket_message *wm, struct jan
 			return "Subscribe error";
 
 		/* create SDP */
-		ret = sdp_create(jsep_sdp_out, dest_ml, &flags);
+		ret = sdp_create(jsep_sdp_out, dest_ml, NULL, &flags);
 
 		if (!dest_ml->janus_session)
 			dest_ml->janus_session = obj_get(session);
@@ -881,7 +881,7 @@ static const char *janus_videoroom_configure(struct websocket_message *wm, struc
 		// XXX check there's only one audio and one video stream?
 
 		g_auto(str) sdp_out = STR_NULL;
-		ret = sdp_create(&sdp_out, ml, &flags);
+		ret = sdp_create(&sdp_out, ml, &streams, &flags);
 		if (ret)
 			return "Publish error";
 

daemon/sdp.c

@@ -1789,7 +1789,8 @@ int sdp_streams(const sdp_sessions_q *sessions, sdp_streams_q *streams, sdp_ng_f
 		session = l->data;
 
 		/* carry some of session level attributes for a later usage, using flags
-		 * e.g. usage in `__call_monologue_init_from_flags()`
+		 * e.g. usage in `__call_monologue_init_from_flags()` or direct usage
+		 * in `sdp_create()`
 		 */
 		sdp_attr_append_other(&flags->session_attributes, &session->attributes);
 		flags->session_sdp_orig = session->origin;
@@ -3431,6 +3432,29 @@ static void sdp_out_add_session_name(GString *out, struct call_monologue *monolo
 	g_string_append_printf(out, "s=%s\r\n", sdp_session_name);
 }
 
+static void sdp_out_add_media_connection(GString *out, struct call_media *media,
+		struct packet_stream *rtp_ps, struct stream_params *sp,
+		sdp_ng_flags *flags)
+{
+	const char *media_conn_address = NULL;
+	const char *media_conn_address_type = rtp_ps->selected_sfd->local_intf->advertised_address.addr.family->rfc_name;
+
+	/* we want to keep an original media connection for message / force relay */
+	if (sp && (media->type_id == MT_MESSAGE || flags->ice_option == ICE_FORCE_RELAY))
+	{
+		media_conn_address = sockaddr_print_buf(&sp->rtp_endpoint.address);
+		media_conn_address_type = sp->rtp_endpoint.address.family->rfc_name;
+	}
+	else {
+		media_conn_address = sockaddr_print_buf(&rtp_ps->selected_sfd->local_intf->advertised_address.addr);
+	}
+
+	g_string_append_printf(out,
+			"c=IN %s %s\r\n",
+			media_conn_address_type,
+			media_conn_address);
+}
+
 /**
  * For the offer/answer model, SDP create will be triggered for the B monologue,
  * which likely has empty paramaters (such as sdp origin, session name etc.), hence
@@ -3439,10 +3463,12 @@ static void sdp_out_add_session_name(GString *out, struct call_monologue *monolo
  * For the rest of cases (publish, subscribe, janus etc.) this works as usual:
  * given monologue is a monologue which is being processed.
  */
-int sdp_create(str *out, struct call_monologue *monologue, sdp_ng_flags *flags)
+int sdp_create(str *out, struct call_monologue *monologue,
+	 sdp_streams_q *streams, sdp_ng_flags *flags)
 {
 	const char *err = NULL;
 	GString *s = NULL;
+	struct stream_params *sp;
 
 	err = "Need at least one media";
 	if (!monologue->medias->len)
@@ -3467,13 +3493,23 @@ int sdp_create(str *out, struct call_monologue *monologue, sdp_ng_flags *flags)
 	/* add an actual sdp session name */
 	sdp_out_add_session_name(s, monologue, flags->opmode);
 
+	/* don't set connection on the session level
+	 * but instead per media, below */
+
 	/* set timing to always be: 0 0 */
 	g_string_append(s, "t=0 0\r\n");
 
 	monologue->sdp_attr_print(s, monologue, flags);
 
-	for (unsigned int i = 0; i < monologue->medias->len; i++) {
+	for (unsigned int i = 0; i < monologue->medias->len; i++)
+	{
 		media = monologue->medias->pdata[i];
+
+		/* take corresponding stream to get per media flags */
+		sp = NULL;
+		if (streams)
+			sp = t_queue_peek_nth(streams, i);
+
 		err = "Empty media stream";
 		if (!media)
 			continue;
@@ -3499,9 +3535,14 @@ int sdp_create(str *out, struct call_monologue *monologue, sdp_ng_flags *flags)
 		else
 			goto err;
 		print_codec_list(s, media);
-		g_string_append_printf(s, "\r\nc=IN %s %s\r\n",
-				rtp_ps->selected_sfd->local_intf->advertised_address.addr.family->rfc_name,
-				sockaddr_print_buf(&rtp_ps->selected_sfd->local_intf->advertised_address.addr));
+
+		/* after codecs added, add newline  */
+		g_string_append_printf(s, "\r\n");
+
+		/* add an actual media connection */
+		sdp_out_add_media_connection(s, media, rtp_ps, sp, flags);
+
+		/* print media level attributes */
 		print_sdp_media_section(s, media, NULL, flags, rtp_ps_link, true, false);
 	}
 

include/sdp.h

@@ -81,7 +81,7 @@ void sdp_streams_clear(sdp_streams_q *);
 void sdp_sessions_clear(sdp_sessions_q *sessions);
 int sdp_replace(struct sdp_chopper *, sdp_sessions_q *, struct call_monologue *, sdp_ng_flags *);
 int sdp_is_duplicate(sdp_sessions_q *sessions);
-int sdp_create(str *out, struct call_monologue *, sdp_ng_flags *flags);
+int sdp_create(str *out, struct call_monologue *, sdp_streams_q *streams, sdp_ng_flags *flags);
 const char *sdp_get_sendrecv(struct call_media *media);
 
 int sdp_parse_candidate(struct ice_candidate *cand, const str *s); // returns -1, 0, 1