MT#55283 introduce `inactive` flag

Used to pause media sent to a subscription

Change-Id: I208c12c85350f44c11b1a97ebee2ea8aba6d28e0

daemon/call.c

@@ -3410,7 +3410,10 @@ static int monologue_subscribe_request1(struct call_monologue *src_ml, struct ca
 
 		codec_handlers_update(dst_media, src_media, flags, sp);
 
-		bf_copy(&dst_media->media_flags, MEDIA_FLAG_SEND, &src_media->media_flags, SP_FLAG_RECV);
+		if (!flags->inactive)
+			bf_copy(&dst_media->media_flags, MEDIA_FLAG_SEND, &src_media->media_flags, SP_FLAG_RECV);
+		else
+			MEDIA_CLEAR(dst_media, SEND);
 		MEDIA_CLEAR(dst_media, RECV);
 
 		__rtcp_mux_set(flags, dst_media);

daemon/call_interfaces.c

@@ -1051,6 +1051,9 @@ static void call_ng_flags_flags(struct sdp_ng_flags *out, str *s, void *dummy) {
 		case CSH_LOOKUP("record-call"):
 			out->record_call = 1;
 			break;
+		case CSH_LOOKUP("inactive"):
+			out->inactive = 1;
+			break;
 		case CSH_LOOKUP("debug"):
 			out->debug = 1;
 			break;

docs/ng_control_protocol.md

@@ -834,6 +834,12 @@ Spaces in each string may be replaced by hyphens.
 
 	Add `a=mid` attributes to the outgoing SDP if they were not already present.
 
+* `inactive`
+
+    Useful for `subscribe request` messages to produce an SDP which is marked
+    as inactive, instead of `sendonly` which is the default. This can be used
+    to pause media sent to a subscription.
+
 * `inject DTMF`
 
 	Signals to *rtpengine* that the audio streams involved in this `offer` or `answer`

include/call_interfaces.h

@@ -158,6 +158,7 @@ struct sdp_ng_flags {
 	             fragment:1,
 	             record_call:1,
 		     debug:1,
+		     inactive:1,
 	             loop_protect:1,
 	             original_sendrecv:1,
 	             single_codec:1,