MT#60476 Add handling of `end-of-candidates`

Flag the media via stream params, when it's
trickle or non-trickle offer/answer, and,
unflag it always only when it's non-trickle.

Change-Id: Ia85ce5792684a4121e224aff1a8e941e061fe5a8

daemon/call.c

@@ -2839,6 +2839,7 @@ static void __media_init_from_flags(struct call_media *other_media, struct call_
 		bf_copy_same(&other_media->media_flags, &sp->sp_flags,
 				SHARED_FLAG_RTCP_MUX | SHARED_FLAG_ASYMMETRIC | SHARED_FLAG_UNIDIRECTIONAL |
 				SHARED_FLAG_ICE | SHARED_FLAG_TRICKLE_ICE | SHARED_FLAG_ICE_LITE_PEER |
+				SHARED_FLAG_END_OF_CANDIDATES |
 				SHARED_FLAG_RTCP_FB | SHARED_FLAG_LEGACY_OSRTP | SHARED_FLAG_LEGACY_OSRTP_REV);
 
 		// duplicate the entire queue of offered crypto params

daemon/sdp.c

@@ -1568,6 +1568,7 @@ static void __sdp_ice(struct stream_params *sp, struct sdp_media *media) {
 	struct sdp_attribute *attr;
 	struct attribute_candidate *ac;
 	struct ice_candidate *cand;
+	bool end_of_candidates = (attr_get_by_id_m_s(media, ATTR_END_OF_CANDIDATES));
 
 	attr = attr_get_by_id_m_s(media, ATTR_ICE_UFRAG);
 	if (!attr)
@@ -1598,6 +1599,13 @@ no_cand:
 	else if (is_trickle_ice_address(&sp->rtp_endpoint))
 		SP_SET(sp, TRICKLE_ICE);
 
+	/* set end_of_candidates flag both, when it's trickle ice or not */
+	if (end_of_candidates)
+		SP_SET(sp, END_OF_CANDIDATES);
+	/* unset end_of_candidates flag, if it's non trickle and no attribute given */
+	if (!SP_ISSET(sp, TRICKLE_ICE) && !end_of_candidates)
+		SP_CLEAR(sp, END_OF_CANDIDATES);
+
 	if (attr_get_by_id_m_s(media, ATTR_ICE_LITE))
 		SP_SET(sp, ICE_LITE_PEER);
 
@@ -2108,6 +2116,10 @@ void sdp_insert_monologue_attributes(GString *gs, union sdp_attr_print_arg a, co
 void sdp_insert_all_attributes(GString *s, struct call_media *media, struct sdp_ng_flags *flags) {
 	for (__auto_type l = media->all_attributes.head; l; l = l->next) {
 		__auto_type a = l->data;
+		// the one exception: skip this and then print it separately if it was present,
+		// so that we can print our own candidates first
+		if (a->attr == ATTR_END_OF_CANDIDATES)
+			continue;
 		append_str_attr_to_gstring(s, &a->strs.name, &a->strs.value, flags, media->type_id);
 	}
 }
@@ -3007,6 +3019,8 @@ static void sdp_out_original_media_attributes(GString *out, struct call_media *m
 		if (rtcp_ps && (!rtcp_ps->selected_sfd || rtcp_ps->selected_sfd->socket.local.port == 0))
 			rtcp_ps = NULL;
 		insert_candidates(out, rtp_ps, rtcp_ps, flags, source_media);
+		if (MEDIA_ISSET(source_media, END_OF_CANDIDATES))
+			append_attr_to_gstring(out, "end-of-candidates", NULL, flags, media->type_id);
 	}
 }
 

include/call.h

@@ -139,6 +139,8 @@ enum {
 #define SHARED_FLAG_RTCP_FB			0x00002000
 #define SHARED_FLAG_LEGACY_OSRTP		0x00004000
 #define SHARED_FLAG_LEGACY_OSRTP_REV		0x00008000
+/* empty range in-between */
+#define SHARED_FLAG_END_OF_CANDIDATES		0x40000000LL
 
 /* struct stream_params */
 #define SP_FLAG_NO_RTCP				0x00010000
@@ -158,6 +160,7 @@ enum {
 #define SP_FLAG_RTCP_FB				SHARED_FLAG_RTCP_FB
 #define SP_FLAG_LEGACY_OSRTP			SHARED_FLAG_LEGACY_OSRTP
 #define SP_FLAG_LEGACY_OSRTP_REV		SHARED_FLAG_LEGACY_OSRTP_REV
+#define SP_FLAG_END_OF_CANDIDATES		SHARED_FLAG_END_OF_CANDIDATES
 
 /* struct packet_stream */
 #define PS_FLAG_RTP				0x00010000
@@ -209,6 +212,7 @@ enum {
 #define MEDIA_FLAG_LEGACY_OSRTP_REV		SHARED_FLAG_LEGACY_OSRTP_REV
 #define MEDIA_FLAG_TRANSCODING			0x100000000LL
 #define MEDIA_FLAG_BLOCK_EGRESS			0x200000000LL
+#define MEDIA_FLAG_END_OF_CANDIDATES		SHARED_FLAG_END_OF_CANDIDATES
 
 /* struct call_monologue */
 #define ML_FLAG_REC_FORWARDING			0x00010000