Add 'unidirectional' attribute

In order to kernelize unidirectional streams.

README.md

@@ -711,6 +711,10 @@ Optionally included keys are:
 		Corresponds to the *rtpproxy* `a` flag. Advertises an RTP endpoint which uses asymmetric
 		RTP, which disables learning of endpoint addresses (see below).
 
+	- `unidirectional`
+
+		When this flag is present, kernelize also one-way rtp media.
+
 	- `strict source`
 
 		Normally, *rtpengine* attempts to learn the correct endpoint address for every stream during

daemon/call.c

@@ -1553,8 +1553,8 @@ int monologue_offer_answer(struct call_monologue *other_ml, GQueue *streams,
 		if (sp->rtp_endpoint.port) {
 			/* copy parameters advertised by the sender of this message */
 			bf_copy_same(&other_media->media_flags, &sp->sp_flags,
-					SHARED_FLAG_RTCP_MUX | SHARED_FLAG_ASYMMETRIC | SHARED_FLAG_ICE
-					| SHARED_FLAG_TRICKLE_ICE | SHARED_FLAG_ICE_LITE);
+					SHARED_FLAG_RTCP_MUX | SHARED_FLAG_ASYMMETRIC | SHARED_FLAG_UNIDIRECTIONAL |
+					SHARED_FLAG_ICE | SHARED_FLAG_TRICKLE_ICE | SHARED_FLAG_ICE_LITE);
 
 			crypto_params_copy(&other_media->sdes_in.params, &sp->crypto, 1);
 			other_media->sdes_in.tag = sp->sdes_tag;

daemon/call.h

@@ -124,6 +124,7 @@ enum call_stream_state {
 #define SHARED_FLAG_MEDIA_HANDOVER		0x00000200
 #define SHARED_FLAG_TRICKLE_ICE			0x00000400
 #define SHARED_FLAG_ICE_LITE			0x00000800
+#define SHARED_FLAG_UNIDIRECTIONAL		0x00001000
 
 /* struct stream_params */
 #define SP_FLAG_NO_RTCP				0x00010000
@@ -132,6 +133,7 @@ enum call_stream_state {
 #define SP_FLAG_SEND				SHARED_FLAG_SEND
 #define SP_FLAG_RECV				SHARED_FLAG_RECV
 #define SP_FLAG_ASYMMETRIC			SHARED_FLAG_ASYMMETRIC
+#define SP_FLAG_UNIDIRECTIONAL			SHARED_FLAG_UNIDIRECTIONAL
 #define SP_FLAG_SETUP_ACTIVE			SHARED_FLAG_SETUP_ACTIVE
 #define SP_FLAG_SETUP_PASSIVE			SHARED_FLAG_SETUP_PASSIVE
 #define SP_FLAG_ICE				SHARED_FLAG_ICE
@@ -159,6 +161,7 @@ enum call_stream_state {
 /* struct call_media */
 #define MEDIA_FLAG_INITIALIZED			0x00010000
 #define MEDIA_FLAG_ASYMMETRIC			SHARED_FLAG_ASYMMETRIC
+#define MEDIA_FLAG_UNIDIRECTIONAL		SHARED_FLAG_UNIDIRECTIONAL
 #define MEDIA_FLAG_SEND				SHARED_FLAG_SEND
 #define MEDIA_FLAG_RECV				SHARED_FLAG_RECV
 #define MEDIA_FLAG_RTCP_MUX			SHARED_FLAG_RTCP_MUX

daemon/call_interfaces.c

@@ -541,6 +541,8 @@ static void call_ng_process_flags(struct sdp_ng_flags *out, bencode_item_t *inpu
 				out->trust_address = 0;
 			else if (!bencode_strcmp(it, "asymmetric"))
 				out->asymmetric = 1;
+			else if (!bencode_strcmp(it, "unidirectional"))
+				out->unidirectional = 1;
 			else if (!bencode_strcmp(it, "strict-source"))
 				out->strict_source = 1;
 			else if (!bencode_strcmp(it, "media-handover"))

daemon/call_interfaces.h

@@ -31,6 +31,7 @@ struct sdp_ng_flags {
 	sockfamily_t *address_family;
 	int tos;
 	int asymmetric:1,
+	    unidirectional:1,
 	    trust_address:1,
 	    port_latching:1,
 	    replace_origin:1,

daemon/media_socket.c

@@ -1204,6 +1204,11 @@ loop_ok:
 	if (MEDIA_ISSET(media, ASYMMETRIC))
 		PS_SET(stream, CONFIRMED);
 
+	/* confirm sink for unidirectional streams in order to kernelize */
+	if (MEDIA_ISSET(media, UNIDIRECTIONAL)) {
+		PS_SET(sink, CONFIRMED);
+	}
+
 	/* if we have already updated the endpoint in the past ... */
 	if (PS_ISSET(stream, CONFIRMED)) {
 		/* see if we need to compare the source address with the known endpoint */

daemon/sdp.c

@@ -1188,6 +1188,7 @@ int sdp_streams(const GQueue *sessions, GQueue *streams, struct sdp_ng_flags *fl
 			memcpy(sp->direction, flags->direction, sizeof(sp->direction));
 			sp->desired_family = flags->address_family;
 			bf_set_clear(&sp->sp_flags, SP_FLAG_ASYMMETRIC, flags->asymmetric);
+			bf_set_clear(&sp->sp_flags, SP_FLAG_UNIDIRECTIONAL, flags->unidirectional);
 			bf_set_clear(&sp->sp_flags, SP_FLAG_STRICT_SOURCE, flags->strict_source);
 			bf_set_clear(&sp->sp_flags, SP_FLAG_MEDIA_HANDOVER, flags->media_handover);