TT#89352 add option to strip a:extmap

closes #1271

Change-Id: I17e177b96983798f693f162c45643b5a82258278

README.md

@@ -790,6 +790,10 @@ Optionally included keys are:
 
 		Add `a=mid` attributes to the outgoing SDP if they were not already present.
 
+	- `strip extmap`
+
+		Remove `a=rtpmap` attributes from the outgoing SDP.
+
 	- `original sendrecv`
 
 		With this flag present, *rtpengine* will leave the media direction attributes

daemon/call_interfaces.c

@@ -815,6 +815,9 @@ static void call_ng_flags_flags(struct sdp_ng_flags *out, str *s, void *dummy) {
 		case CSH_LOOKUP("generate-mid"):
 			out->generate_mid = 1;
 			break;
+		case CSH_LOOKUP("strip-extmap"):
+			out->strip_extmap = 1;
+			break;
 		case CSH_LOOKUP("record-call"):
 			out->record_call = 1;
 			break;

daemon/sdp.c

@@ -2061,6 +2061,10 @@ static int process_session_attributes(struct sdp_chopper *chop, struct sdp_attri
 				goto strip;
 
 			case ATTR_EXTMAP:
+				if (flags->strip_extmap)
+					goto strip;
+				break;
+
 			case ATTR_FINGERPRINT:
 			case ATTR_SETUP:
 			case ATTR_IGNORE:
@@ -2173,6 +2177,12 @@ static int process_media_attributes(struct sdp_chopper *chop, struct sdp_media *
 				break;
 
 			case ATTR_EXTMAP:
+				if (MEDIA_ISSET(media, PASSTHRU))
+					break;
+				if (flags->strip_extmap)
+					goto strip;
+				break;
+
 			case ATTR_CRYPTO:
 			case ATTR_FINGERPRINT:
 			case ATTR_SETUP:

include/call_interfaces.h

@@ -98,6 +98,7 @@ struct sdp_ng_flags {
 	             generate_rtcp:1,
 	             generate_rtcp_off:1,
 	             generate_mid:1,
+		     strip_extmap:1,
 	             strict_source:1,
 	             media_handover:1,
 	             dtls_passive:1,

t/auto-daemon-tests.pl

@@ -9786,6 +9786,57 @@ rcv($sock_b, $port_a, rtpm(0, 1022, 5880, $ssrc, "\x00" x 160));
 
 
 
+# extmap stripping
+
+new_call;
+
+offer('strip extmap control', { }, <<SDP);
+v=0
+o=- 1545997027 1 IN IP4 198.51.100.1
+s=tester
+t=0 0
+m=audio 2000 RTP/AVP 0
+c=IN IP4 198.51.100.1
+a=extmap:0 foobar
+a=sendrecv
+----------------------------------
+v=0
+o=- 1545997027 1 IN IP4 198.51.100.1
+s=tester
+t=0 0
+m=audio PORT RTP/AVP 0
+c=IN IP4 203.0.113.1
+a=extmap:0 foobar
+a=rtpmap:0 PCMU/8000
+a=sendrecv
+a=rtcp:PORT
+SDP
+
+new_call;
+
+offer('strip extmap', { flags => ['strip extmap'] }, <<SDP);
+v=0
+o=- 1545997027 1 IN IP4 198.51.100.1
+s=tester
+t=0 0
+m=audio 2000 RTP/AVP 0
+c=IN IP4 198.51.100.1
+a=extmap:0 foobar
+a=sendrecv
+----------------------------------
+v=0
+o=- 1545997027 1 IN IP4 198.51.100.1
+s=tester
+t=0 0
+m=audio PORT RTP/AVP 0
+c=IN IP4 203.0.113.1
+a=rtpmap:0 PCMU/8000
+a=sendrecv
+a=rtcp:PORT
+SDP
+
+
+
 # SDP in/out tests, various ICE options
 
 new_call;