[BlueZ,v5,5/6] shared/bap: Add API to add an observed BIS

Commit Message

Andrei Istodorescu March 1, 2024, 3 p.m. UTC

Add API to add a PAC for each observed BIS that is supported by the
local PACS data.
Each BIS observed capabilities LTV is compared to the local capabilities
and when we have a full LTVs match a PAC record is created for that BIS.
Also a MediaEndpoint is registered over DBUS and the stream can be
enabled using the SetConfiguration DBUS call.
---
 src/shared/bap.c | 266 ++++++++++++++++++++++++++++++++++++++++++++++-
 src/shared/bap.h |   7 ++
 2 files changed, 268 insertions(+), 5 deletions(-)

Patch

diff --git a/src/shared/bap.c b/src/shared/bap.c
index 50d03456e6cd..b84760da4510 100644
--- a/src/shared/bap.c
+++ b/src/shared/bap.c
@@ -48,6 +48,15 @@ 
 
 #define BAP_PROCESS_TIMEOUT 10
 
+#define BAP_FREQ_LTV_TYPE 1
+#define BAP_DURATION_LTV_TYPE 2
+#define BAP_CHANNEL_ALLOCATION_LTV_TYPE 3
+#define BAP_FRAME_LEN_LTV_TYPE 4
+#define CODEC_SPECIFIC_CONFIGURATION_MASK (\
+		(1<<BAP_FREQ_LTV_TYPE)|\
+		(1<<BAP_DURATION_LTV_TYPE)|\
+		(1<<BAP_FRAME_LEN_LTV_TYPE))
+
 struct bt_bap_pac_changed {
 	unsigned int id;
 	bt_bap_pac_func_t added;
@@ -6002,8 +6011,9 @@  static void add_new_subgroup(struct bt_base *base,
 
 struct bt_ltv_match {
 	uint8_t l;
-	uint8_t *v;
+	void *data;
 	bool found;
+	uint32_t data32;
 };
 
 struct bt_ltv_search {
@@ -6022,7 +6032,7 @@  static void match_ltv(size_t i, uint8_t l, uint8_t t, uint8_t *v,
 	if (ltv_match->l != l)
 		return;
 
-	if (!memcmp(v, ltv_match->v, l))
+	if (!memcmp(v, ltv_match->data, l))
 		ltv_match->found = true;
 }
 
@@ -6034,7 +6044,7 @@  static void search_ltv(size_t i, uint8_t l, uint8_t t, uint8_t *v,
 
 	ltv_match.found = false;
 	ltv_match.l = l;
-	ltv_match.v = v;
+	ltv_match.data = v;
 
 	util_ltv_foreach(ltv_search->iov->iov_base,
 			ltv_search->iov->iov_len, &t,
@@ -6075,8 +6085,10 @@  static bool compare_ltv(struct iovec *iov1,
 }
 
 struct bt_ltv_extract {
-	struct iovec *result;
 	struct iovec *src;
+	void *value;
+	uint8_t len;
+	struct iovec *result;
 };
 
 static void extract_ltv(size_t i, uint8_t l, uint8_t t, uint8_t *v,
@@ -6088,7 +6100,7 @@  static void extract_ltv(size_t i, uint8_t l, uint8_t t, uint8_t *v,
 
 	ltv_match.found = false;
 	ltv_match.l = l;
-	ltv_match.v = v;
+	ltv_match.data = v;
 
 	/* Search each BIS caps ltv in subgroup caps
 	 * to extract the one that are BIS specific
@@ -6221,3 +6233,247 @@  struct iovec *bt_bap_stream_get_base(struct bt_bap_stream *stream)
 
 	return base_iov;
 }
+
+static void bap_sink_get_allocation(size_t i, uint8_t l, uint8_t t,
+		uint8_t *v, void *user_data)
+{
+	uint32_t location32;
+
+	if (!v)
+		return;
+
+	memcpy(&location32, v, l);
+	*((uint32_t *)user_data) = le32_to_cpu(location32);
+}
+
+/*
+ * This function compares PAC Codec Specific Capabilities, with the Codec
+ * Specific Configuration LTVs received in the BASE of the BAP Source. The
+ * result is accumulated in data32 which is a bitmask of types.
+ */
+static void check_pac_caps_ltv(size_t i, uint8_t l, uint8_t t, uint8_t *v,
+					void *user_data)
+{
+	struct bt_ltv_match *compare_data = user_data;
+	uint8_t *bis_v = compare_data->data;
+	uint16_t mask;
+	uint16_t min;
+	uint16_t max;
+	uint16_t frame_len;
+
+	switch (t) {
+	case BAP_FREQ_LTV_TYPE:
+		mask = *((uint16_t *)v);
+		mask = le16_to_cpu(mask);
+		if (mask & (1 << (bis_v[0] - 1)))
+			compare_data->data32 |= 1<<t;
+		break;
+	case BAP_DURATION_LTV_TYPE:
+		if ((v[0]) & (1 << bis_v[0]))
+			compare_data->data32 |= 1<<t;
+		break;
+	case BAP_FRAME_LEN_LTV_TYPE:
+		min = *((uint16_t *)v);
+		max = *((uint16_t *)(&v[2]));
+		frame_len = *((uint16_t *)bis_v);
+		min = le16_to_cpu(min);
+		max = le16_to_cpu(max);
+		frame_len = le16_to_cpu(frame_len);
+		if ((frame_len >= min) &&
+				(frame_len <= max))
+			compare_data->data32 |= 1<<t;
+		break;
+	}
+}
+
+static void check_source_ltv(size_t i, uint8_t l, uint8_t t, uint8_t *v,
+					void *user_data)
+{
+	struct bt_ltv_match *local_data = user_data;
+	struct iovec *pac_caps = local_data->data;
+	struct bt_ltv_match compare_data;
+
+	compare_data.data = v;
+
+	/* Search inside local PAC's caps for LTV of type t */
+	util_ltv_foreach(pac_caps->iov_base, pac_caps->iov_len, &t,
+					check_pac_caps_ltv, &compare_data);
+
+	local_data->data32 |= compare_data.data32;
+}
+
+static void bap_sink_check_level3_ltv(size_t i, uint8_t l, uint8_t t,
+		uint8_t *v, void *user_data)
+{
+	struct bt_ltv_extract *merge_data = user_data;
+
+	merge_data->value = v;
+	merge_data->len = l;
+}
+
+static void bap_sink_check_level2_ltv(size_t i, uint8_t l, uint8_t t,
+		uint8_t *v, void *user_data)
+{
+	struct bt_ltv_extract *merge_data = user_data;
+
+	merge_data->value = NULL;
+	util_ltv_foreach(merge_data->src->iov_base,
+			merge_data->src->iov_len,
+			&t,
+			bap_sink_check_level3_ltv, merge_data);
+
+	/* If the LTV at level 2 was found at level 3 add the one from level 3,
+	 * otherwise add the one at level 2
+	 */
+	if (merge_data->value)
+		util_ltv_push(merge_data->result, merge_data->len,
+				t, merge_data->value);
+	else
+		util_ltv_push(merge_data->result, l, t, v);
+}
+
+static void check_local_pac(void *data, void *user_data)
+{
+	struct bt_ltv_match *compare_data = user_data;
+	struct iovec *bis_data = (struct iovec *)compare_data->data;
+	const struct bt_bap_pac *pac = data;
+
+	/* Keep searching for a matching PAC if one wasn't found
+	 * in previous PAC element
+	 */
+	if (compare_data->found == false) {
+		struct bt_ltv_match bis_compare_data = {
+				.data = pac->data,
+				.data32 = 0, /* LTVs bitmask result */
+				.found = false
+		};
+
+		/* loop each BIS LTV */
+		util_ltv_foreach(bis_data->iov_base, bis_data->iov_len, NULL,
+				check_source_ltv, &bis_compare_data);
+
+		/* We have a match if all selected LTVs have a match */
+		if ((bis_compare_data.data32 &
+			CODEC_SPECIFIC_CONFIGURATION_MASK) ==
+			CODEC_SPECIFIC_CONFIGURATION_MASK)
+			compare_data->found = true;
+	}
+}
+
+static void bap_sink_match_allocation(size_t i, uint8_t l, uint8_t t,
+		uint8_t *v, void *user_data)
+{
+	struct bt_ltv_match *data = user_data;
+	uint32_t location32;
+
+	if (!v)
+		return;
+
+	memcpy(&location32, v, l);
+	location32 = le32_to_cpu(location32);
+
+	/* If all the bits in the received bitmask are found in
+	 * the local bitmask then we have a match
+	 */
+	if ((location32 & data->data32) == location32)
+		data->found = true;
+	else
+		data->found = false;
+}
+
+static bool bap_check_bis(struct bt_bap_db *ldb, struct iovec *bis_data)
+{
+	struct bt_ltv_match compare_data = {};
+
+	/* Check channel allocation against the PACS location.
+	 * If we don't have a location set we can accept any BIS location.
+	 * If the BIS doesn't have a location set we also accept it
+	 */
+	compare_data.found = true;
+
+	if (ldb->pacs->sink_loc_value) {
+		uint8_t type = BAP_CHANNEL_ALLOCATION_LTV_TYPE;
+
+		compare_data.data32 = ldb->pacs->sink_loc_value;
+		util_ltv_foreach(bis_data->iov_base, bis_data->iov_len, &type,
+				bap_sink_match_allocation, &compare_data);
+	}
+
+	/* Check remaining LTVs against the PACs list */
+	if (compare_data.found) {
+		compare_data.data = bis_data;
+		compare_data.found = false;
+		queue_foreach(ldb->broadcast_sinks, check_local_pac,
+				&compare_data);
+	}
+
+	return compare_data.found;
+}
+
+void bt_bap_add_bis(struct bt_bap *bap, uint8_t bis_index,
+		struct bt_bap_codec *codec,
+		struct iovec *l2_caps,
+		struct iovec *l3_caps,
+		struct iovec *meta)
+{
+	struct bt_bap_pac *pac_source_bis;
+	struct bt_bap_endpoint *ep;
+	int err = 0;
+	struct bt_bap_pac_qos bis_qos = {0};
+	uint8_t type = 0;
+	struct bt_ltv_extract merge_data = {0};
+
+	merge_data.src = l3_caps;
+	merge_data.result = new0(struct iovec, 1);
+
+	/* Create a Codec Specific Configuration with LTVs at level 2 (subgroup)
+	 * overwritten by LTVs at level 3 (BIS)
+	 */
+	util_ltv_foreach(l2_caps->iov_base,
+			l2_caps->iov_len,
+			NULL,
+			bap_sink_check_level2_ltv, &merge_data);
+
+	/* Check each BIS Codec Specific Configuration LTVs against our Codec
+	 * Specific Capabilities and if the BIS matches create a PAC with it
+	 */
+	if (bap_check_bis(bap->ldb, merge_data.result) == false)
+		goto cleanup;
+
+	DBG(bap, "Matching BIS %i", bis_index);
+
+	/* Create a QoS structure based on the received BIS information to
+	 * specify the desired channel for this BIS/PAC
+	 */
+	type = BAP_CHANNEL_ALLOCATION_LTV_TYPE;
+	util_ltv_foreach(merge_data.result->iov_base,
+			merge_data.result->iov_len, &type,
+			bap_sink_get_allocation, &bis_qos.location);
+
+	/* Create a remote PAC */
+	pac_source_bis = bap_pac_new(bap->rdb, NULL,
+				BT_BAP_BCAST_SOURCE, codec, &bis_qos,
+				merge_data.result, meta);
+
+	err = asprintf(&pac_source_bis->name, "%d", bis_index);
+
+	if (err < 0) {
+		DBG(bap, "error in asprintf");
+		goto cleanup;
+	}
+
+	/* Add remote source endpoint */
+	if (!bap->rdb->broadcast_sources)
+		bap->rdb->broadcast_sources = queue_new();
+	queue_push_tail(bap->rdb->broadcast_sources, pac_source_bis);
+
+	queue_foreach(bap->pac_cbs, notify_pac_added, pac_source_bis);
+	/* Push remote endpoint with direction sink */
+	ep = bap_endpoint_new_broadcast(bap->rdb, BT_BAP_BCAST_SINK);
+
+	if (ep)
+		queue_push_tail(bap->remote_eps, ep);
+
+cleanup:
+	util_iov_free(merge_data.result, 1);
+}
diff --git a/src/shared/bap.h b/src/shared/bap.h
index e4785b587e3a..76f3fb0adab6 100644
--- a/src/shared/bap.h
+++ b/src/shared/bap.h
@@ -333,3 +333,10 @@  void bt_bap_update_bcast_source(struct bt_bap_pac *pac,
 bool bt_bap_pac_bcast_is_local(struct bt_bap *bap, struct bt_bap_pac *pac);
 
 struct iovec *bt_bap_stream_get_base(struct bt_bap_stream *stream);
+
+void bt_bap_add_bis(struct bt_bap *bap, uint8_t bis_index,
+		struct bt_bap_codec *codec,
+		struct iovec *l2_caps,
+		struct iovec *l3_caps,
+		struct iovec *meta);
+