TT#49045 add new flag to leave media direction attrs unchanged

Change-Id: I2dcafa3be9f8a0dfd7c1cf3e6046dabe9fa5bbee

README.md

@@ -1256,6 +1256,14 @@ Optionally included keys are:
 
 		Add `a=mid` attributes to the outgoing SDP if they were not already present.
 
+	- `original sendrecv`
+
+		With this flag present, *rtpengine* will leave the media direction attributes
+		(`sendrecv`, `recvonly`, `sendonly`, and `inactive`) from the received SDP body
+		unchanged. Normally *rtpengine* would consume these attributes and insert its
+		own version of them based on other media parameters (e.g. a media section with
+		a zero IP address would come out as `sendonly` or `inactive`).
+
 * `replace`
 
 	Similar to the `flags` list. Controls which parts of the SDP body should be rewritten.

daemon/call_interfaces.c

@@ -674,6 +674,9 @@ static void call_ng_flags_flags(struct sdp_ng_flags *out, str *s, void *dummy) {
 		case CSH_LOOKUP("loop-protect"):
 			out->loop_protect = 1;
 			break;
+		case CSH_LOOKUP("original-sendrecv"):
+			out->original_sendrecv = 1;
+			break;
 		case CSH_LOOKUP("always-transcode"):
 			out->always_transcode = 1;
 			break;

daemon/sdp.c

@@ -1627,15 +1627,19 @@ static int process_session_attributes(struct sdp_chopper *chop, struct sdp_attri
 				goto strip;
 
 			case ATTR_EXTMAP:
-			case ATTR_INACTIVE:
-			case ATTR_SENDONLY:
-			case ATTR_RECVONLY:
-			case ATTR_SENDRECV:
 			case ATTR_FINGERPRINT:
 			case ATTR_SETUP:
 			case ATTR_IGNORE:
 				goto strip;
 
+			case ATTR_INACTIVE:
+			case ATTR_SENDONLY:
+			case ATTR_RECVONLY:
+			case ATTR_SENDRECV:
+				if (!flags->original_sendrecv)
+					goto strip;
+				break;
+
 			case ATTR_GROUP:
 				if (attr->u.group.semantics == GROUP_BUNDLE)
 					goto strip;
@@ -1697,16 +1701,21 @@ static int process_media_attributes(struct sdp_chopper *chop, struct sdp_media *
 			case ATTR_RTCP_MUX:
 				if (flags->ice_force_relay)
 					break;
-				// fall thru
-			case ATTR_INACTIVE:
-			case ATTR_SENDONLY:
-			case ATTR_RECVONLY:
-			case ATTR_SENDRECV:
+				goto strip;
+
 			case ATTR_IGNORE:
 			case ATTR_END_OF_CANDIDATES: // we strip it here and re-insert it later
 			case ATTR_MID:
 				goto strip;
 
+			case ATTR_INACTIVE:
+			case ATTR_SENDONLY:
+			case ATTR_RECVONLY:
+			case ATTR_SENDRECV:
+				if (!flags->original_sendrecv)
+					goto strip;
+				break;
+
 			case ATTR_RTPMAP:
 			case ATTR_FMTP:
 			case ATTR_PTIME:
@@ -2096,14 +2105,16 @@ int sdp_replace(struct sdp_chopper *chop, GQueue *sessions, struct call_monologu
 			if (!sdp_media->port_num || !ps->selected_sfd)
 				goto next;
 
-			if (MEDIA_ARESET2(call_media, SEND, RECV))
-				chopper_append_c(chop, "a=sendrecv\r\n");
-			else if (MEDIA_ISSET(call_media, SEND))
-				chopper_append_c(chop, "a=sendonly\r\n");
-			else if (MEDIA_ISSET(call_media, RECV))
-				chopper_append_c(chop, "a=recvonly\r\n");
-			else
-				chopper_append_c(chop, "a=inactive\r\n");
+			if (!flags->original_sendrecv) {
+				if (MEDIA_ARESET2(call_media, SEND, RECV))
+					chopper_append_c(chop, "a=sendrecv\r\n");
+				else if (MEDIA_ISSET(call_media, SEND))
+					chopper_append_c(chop, "a=sendonly\r\n");
+				else if (MEDIA_ISSET(call_media, RECV))
+					chopper_append_c(chop, "a=recvonly\r\n");
+				else
+					chopper_append_c(chop, "a=inactive\r\n");
+			}
 
 			if (call_media->protocol && call_media->protocol->rtp) {
 				if (MEDIA_ISSET(call_media, RTCP_MUX)

include/call_interfaces.h

@@ -64,6 +64,7 @@ struct sdp_ng_flags {
 	    fragment:1,
 	    record_call:1,
 	    loop_protect:1,
+	    original_sendrecv:1,
 	    always_transcode:1,
 	    asymmetric_codecs:1,
 	    supports_load_limit:1,

utils/rtpengine-ng-client

@@ -64,6 +64,7 @@ GetOptions(
 	'pad-crypto'			=> \$options{'pad crypto'},
 	'generate-mid'			=> \$options{'generate mid'},
 	'fragment'			=> \$options{'fragment'},
+	'original-sendrecv'		=> \$options{'original sendrecv'},
 ) or die;
 
 my $cmd = shift(@ARGV) or die;
@@ -76,7 +77,7 @@ for my $x (split(/,/, 'from-tag,to-tag,call-id,transport protocol,media address,
 for my $x (split(/,/, 'TOS,delete-delay')) {
 	defined($options{$x}) and $packet{$x} = $options{$x};
 }
-for my $x (split(/,/, 'trust address,symmetric,asymmetric,force,strict source,media handover,sip source address,reset,port latching,no rtcp attribute,full rtcp attribute,loop protect,record call,always transcode,all,pad crypto,generate mid,fragment')) {
+for my $x (split(/,/, 'trust address,symmetric,asymmetric,force,strict source,media handover,sip source address,reset,port latching,no rtcp attribute,full rtcp attribute,loop protect,record call,always transcode,all,pad crypto,generate mid,fragment,original sendrecv')) {
 	defined($options{$x}) and push(@{$packet{flags}}, $x);
 }
 for my $x (split(/,/, 'origin,session connection')) {