MT#60476 Add `call_media_get_top_ms()` getter

Add a getter function for retrieval of top
most media from given media.

Currently existing getter for the top most
monologue's media subscription, just rename
so it makes more sense and is better to
differentiate:
`call_get_top_media_subscription()` -> `call_ml_get_top_ms()`

Change-Id: I5bf13b69b4d5f67cd6b53018b5a16d759542cd41

daemon/call.c

@@ -3322,6 +3322,7 @@ static void __subscribe_medias_both_ways(struct call_media * a, struct call_medi
 
 /**
  * Retrieve exsisting media subscriptions for a call monologue.
+ * Checks if given media is in subscriptions/subscribers HT of opposite media.
  */
 struct media_subscription *call_get_media_subscription(subscription_ht ht, struct call_media * cm) {
 	subscription_list *l = t_hash_table_lookup(ht, cm);
@@ -3330,12 +3331,21 @@ struct media_subscription *call_get_media_subscription(subscription_ht ht, struc
 	return l->data;
 }
 
+/**
+ * Retrieve top most media subscription of given media.
+ */
+struct media_subscription *call_media_get_top_ms(struct call_media * cm) {
+	if (cm->media_subscriptions.head)
+		return cm->media_subscriptions.head->data;
+	return NULL;
+}
+
 /**
  * Retrieve top most media subscription of top media for a given call monologue.
  * It's useful for offer/answer model cases,
  * where most of cases single-to-single subscription model is used.
  */
-struct media_subscription *call_get_top_media_subscription(struct call_monologue *ml) {
+struct media_subscription *call_ml_get_top_ms(struct call_monologue *ml) {
 	for (int i = 0; i < ml->medias->len; i++)
 	{
 		struct call_media * media = ml->medias->pdata[i];

daemon/sdp.c

@@ -2477,7 +2477,7 @@ static void sdp_version_check(GString *s, struct call_monologue *monologue,
 	sdp_origin *origin = monologue->session_last_sdp_orig;
 	sdp_origin *other_origin = NULL;
 
-	struct media_subscription *ms = call_get_top_media_subscription(monologue);
+	struct media_subscription *ms = call_ml_get_top_ms(monologue);
 	if (ms && ms->monologue && ms->monologue->session_sdp_orig)
 		other_origin = ms->monologue->session_sdp_orig;
 
@@ -2736,7 +2736,7 @@ static void sdp_out_add_origin(GString *out, struct call_monologue *monologue,
 	/* for the offer/answer model or subscribe don't use the given monologues SDP,
 	 * but try the one of the subscription, because the given monologue itself
 	 * has likely no session attributes set yet */
-	struct media_subscription *ms = call_get_top_media_subscription(monologue);
+	struct media_subscription *ms = call_ml_get_top_ms(monologue);
 	if (ms && ms->monologue)
 		ml = ms->monologue;
 
@@ -2791,7 +2791,7 @@ static void sdp_out_add_session_name(GString *out, struct call_monologue *monolo
 	/* for the offer/answer model or subscribe don't use the given monologues SDP,
 	 * but try the one of the subscription, because the given monologue itself
 	 * has likely no session attributes set yet */
-	struct media_subscription *ms = call_get_top_media_subscription(monologue);
+	struct media_subscription *ms = call_ml_get_top_ms(monologue);
 	if (ms && ms->monologue)
 	{
 		/* if a session name was empty in the s= attr of the coming message,
@@ -2811,7 +2811,7 @@ static void sdp_out_add_timing(GString *out, struct call_monologue *monologue)
 	/* sdp timing per session level */
 	g_string_append(out, "t=");
 
-	struct media_subscription *ms = call_get_top_media_subscription(monologue);
+	struct media_subscription *ms = call_ml_get_top_ms(monologue);
 	if (ms && ms->monologue && ms->monologue->sdp_session_timing.len)
 		g_string_append_len(out, ms->monologue->sdp_session_timing.s, ms->monologue->sdp_session_timing.len);
 	else
@@ -2827,7 +2827,7 @@ static void sdp_out_add_other(GString *out, struct call_monologue *monologue,
 	bool media_has_ice = MEDIA_ISSET(media, ICE);
 	bool media_has_ice_lite_self = MEDIA_ISSET(media, ICE_LITE_SELF);
 
-	struct media_subscription *ms = call_get_top_media_subscription(monologue);
+	struct media_subscription *ms = call_ml_get_top_ms(monologue);
 
 	/* add loop protectio if required */
 	if (flags->loop_protect)
@@ -2855,7 +2855,7 @@ static void sdp_out_add_bandwidth(GString *out, struct call_monologue *monologue
 	/* if there's a media given, only do look up the values for that one */
 	if (media) {
 		/* sdp bandwidth per media level */
-		struct media_subscription *ms = media->media_subscriptions.head ? media->media_subscriptions.head->data : NULL;
+		struct media_subscription *ms = call_media_get_top_ms(media);
 		if (!ms || !ms->media)
 			return;
 		if (ms->media->sdp_media_bandwidth.as >= 0)
@@ -2870,7 +2870,7 @@ static void sdp_out_add_bandwidth(GString *out, struct call_monologue *monologue
 	else {
 		/* sdp bandwidth per session/media level
 		* 0 value is supported (e.g. b=RR:0 and b=RS:0), to be able to disable rtcp */
-		struct media_subscription *ms = call_get_top_media_subscription(monologue);
+		struct media_subscription *ms = call_ml_get_top_ms(monologue);
 		if (!ms || !ms->monologue)
 			return;
 		if (ms->monologue->sdp_session_bandwidth.as >= 0)
@@ -3034,7 +3034,7 @@ static struct call_media *sdp_out_set_source_media_address(struct call_media *me
 	/* the port and address that goes into the SDP also depends on this */
 	*sdp_address = rtp_ps->selected_sfd ? &rtp_ps->selected_sfd->socket.local : NULL;
 
-	struct media_subscription *ms = media->media_subscriptions.head ? media->media_subscriptions.head->data : NULL;
+	struct media_subscription *ms = call_media_get_top_ms(media);
 	if (ms && ms->media) {
 		source_media = ms->media;
 		/* cases with message, force relay and pass through */

include/call.h

@@ -805,7 +805,8 @@ void __monologue_viabranch(struct call_monologue *ml, const str *viabranch);
 struct packet_stream *__packet_stream_new(call_t *call);
 void __add_media_subscription(struct call_media * which, struct call_media * to,
 		const struct sink_attrs *attrs);
-struct media_subscription *call_get_top_media_subscription(struct call_monologue *ml);
+struct media_subscription *call_ml_get_top_ms(struct call_monologue *ml);
+struct media_subscription *call_media_get_top_ms(struct call_media * cm);
 struct media_subscription *call_get_media_subscription(subscription_ht ht, struct call_media * cm);
 struct call_monologue * ml_medias_subscribed_to_single_ml(struct call_monologue *ml);