Bluetooth: audio: Add possibility to use static broadcast id

fredrikdanebjer · aescolar · commit f970b066d210 · 2024-10-25T14:07:25.000+02:00
Removed the generation of broadcast id inside the stack. It is now up
to the application to generate this by itself. The CAP sample has
been modified to allow either a static broadcast, or a random one.
All of this is handled in the application.

Signed-off-by: Fredrik Danebjer &lt;frdn@demant.com&gt;
diff --git a/doc/releases/migration-guide-4.0.rst b/doc/releases/migration-guide-4.0.rst
@@ -388,6 +388,13 @@ Bluetooth Audio
   do a search-and-replace for ``bt_audio_codec_qos`` to ``bt_bap_qos_cfg`` and
   ``BT_AUDIO_CODEC_QOS`` to ``BT_BAP_QOS_CFG``. (:github:`76633`)
 
+* The generation of broadcast ID inside of zephyr stack has been removed, it is now up the
+  application to generate a broadcast ID. This means that the application can now fully decide
+  whether to use a static or random broadcast ID. Reusing and statically defining a broadcast ID was
+  added to the Basic Audio Profile in version 1.0.2, which is the basis for this change. All
+  instances of :c:func:`bt_cap_initiator_broadcast_get_id` and
+  :c:func:`bt_bap_broadcast_source_get_id` has been removed(:github:`80228`)
+
 Bluetooth Classic
 =================
 
diff --git a/include/zephyr/bluetooth/audio/bap.h b/include/zephyr/bluetooth/audio/bap.h
@@ -2184,22 +2184,6 @@ int bt_bap_broadcast_source_stop(struct bt_bap_broadcast_source *source);
  */
 int bt_bap_broadcast_source_delete(struct bt_bap_broadcast_source *source);
 
-/**
- * @brief Get the broadcast ID of a broadcast source
- *
- * This will return the 3-octet broadcast ID that should be advertised in the
- * extended advertising data with @ref BT_UUID_BROADCAST_AUDIO_VAL as @ref BT_DATA_SVC_DATA16.
- *
- * See table 3.14 in the Basic Audio Profile v1.0.1 for the structure.
- *
- * @param[in]  source        Pointer to the broadcast source.
- * @param[out] broadcast_id  Pointer to the 3-octet broadcast ID.
- *
- * @return Zero on success or (negative) error code otherwise.
- */
-int bt_bap_broadcast_source_get_id(struct bt_bap_broadcast_source *source,
-				   uint32_t *const broadcast_id);
-
 /**
  * @brief Get the Broadcast Audio Stream Endpoint of a broadcast source
  *
diff --git a/include/zephyr/bluetooth/audio/cap.h b/include/zephyr/bluetooth/audio/cap.h
@@ -603,23 +603,6 @@ int bt_cap_initiator_broadcast_audio_stop(struct bt_cap_broadcast_source *broadc
  */
 int bt_cap_initiator_broadcast_audio_delete(struct bt_cap_broadcast_source *broadcast_source);
 
-/**
- * @brief Get the broadcast ID of a Common Audio Profile broadcast source
- *
- * This will return the 3-octet broadcast ID that should be advertised in the
- * extended advertising data with @ref BT_UUID_BROADCAST_AUDIO_VAL as
- * @ref BT_DATA_SVC_DATA16.
- *
- * See table 3.14 in the Basic Audio Profile v1.0.1 for the structure.
- *
- * @param[in]  broadcast_source  Pointer to the broadcast source.
- * @param[out] broadcast_id      Pointer to the 3-octet broadcast ID.
- *
- * @return int		0 if on success, errno on error.
- */
-int bt_cap_initiator_broadcast_get_id(const struct bt_cap_broadcast_source *broadcast_source,
-				      uint32_t *const broadcast_id);
-
 /**
  * @brief Get the Broadcast Audio Stream Endpoint of a Common Audio Profile broadcast source
  *
diff --git a/samples/bluetooth/bap_broadcast_source/Kconfig b/samples/bluetooth/bap_broadcast_source/Kconfig
@@ -45,4 +45,18 @@ config BROADCAST_CODE
 	   Setting a non-empty string for this option will encrypt the broadcast using this
 	   string as the broadcast code. The length of the string shall be between 1 and 16 octets.
 
+config STATIC_BROADCAST_ID
+	bool "Use static broadcast ID"
+	default y
+	help
+	   Enabling this option will make the application use static broadcast ID, as opposed to a
+	   randomly generated one.
+
+config BROADCAST_ID
+	hex "The static broadcast ID to use"
+	range 0x000000 0xFFFFFF
+	depends on STATIC_BROADCAST_ID
+	help
+	   This is the 3-octet broadcast ID advertised if static broadcast IDs are enabled.
+
 source "Kconfig.zephyr"
diff --git a/samples/bluetooth/bap_broadcast_source/prj.conf b/samples/bluetooth/bap_broadcast_source/prj.conf
@@ -14,3 +14,4 @@ CONFIG_BT_ISO_TX_BUF_COUNT=6
 CONFIG_BT_ISO_TX_MTU=60
 
 CONFIG_BT_DEVICE_NAME="Broadcast Audio Source"
+CONFIG_BROADCAST_ID=0x123456
diff --git a/samples/bluetooth/bap_broadcast_source/src/main.c b/samples/bluetooth/bap_broadcast_source/src/main.c
@@ -518,11 +518,15 @@ int main(void)
 			return 0;
 		}
 
-		err = bt_bap_broadcast_source_get_id(broadcast_source, &broadcast_id);
-		if (err != 0) {
-			printk("Unable to get broadcast ID: %d\n", err);
-			return 0;
+#if defined(CONFIG_STATIC_BROADCAST_ID)
+		broadcast_id = CONFIG_BROADCAST_ID;
+#else
+		err = bt_rand(&broadcast_id, BT_AUDIO_BROADCAST_ID_SIZE);
+		if (err) {
+			printk("Unable to generate broadcast ID: %d\n", err);
+			return err;
 		}
+#endif /* CONFIG_STATIC_BROADCAST_ID */
 
 		/* Setup extended advertising data */
 		net_buf_simple_add_le16(&ad_buf, BT_UUID_BROADCAST_AUDIO_VAL);
diff --git a/samples/bluetooth/cap_initiator/Kconfig b/samples/bluetooth/cap_initiator/Kconfig
@@ -26,4 +26,18 @@ config SAMPLE_BROADCAST
 	help
 	  If set to true, the sample will start advertising syncable audio streams
 
+config STATIC_BROADCAST_ID
+	bool "Use static broadcast ID"
+	default y
+	help
+	   Enabling this option will make the application use static broadcast ID, as opposed to a
+	   randomly generated one.
+
+config BROADCAST_ID
+	hex "The static broadcast ID to use"
+	range 0x000000 0xFFFFFF
+	depends on STATIC_BROADCAST_ID
+	help
+	   This is the 3-octet broadcast ID advertised if static broadcast IDs are enabled.
+
 source "Kconfig.zephyr"
diff --git a/samples/bluetooth/cap_initiator/prj.conf b/samples/bluetooth/cap_initiator/prj.conf
@@ -23,3 +23,4 @@ CONFIG_BT_BAP_BROADCAST_SOURCE=y
 # Broadcast sources values if enabled by CONFIG_SAMPLE_BROADCAST
 CONFIG_BT_BAP_BROADCAST_SRC_STREAM_COUNT=2
 CONFIG_BT_BAP_BROADCAST_SRC_SUBGROUP_COUNT=1
+CONFIG_BROADCAST_ID=0x123456
diff --git a/samples/bluetooth/cap_initiator/src/cap_initiator_broadcast.c b/samples/bluetooth/cap_initiator/src/cap_initiator_broadcast.c
@@ -133,11 +133,15 @@ static int setup_extended_adv_data(struct bt_cap_broadcast_source *source,
 	uint32_t broadcast_id;
 	int err;
 
-	err = bt_cap_initiator_broadcast_get_id(source, &broadcast_id);
-	if (err != 0) {
-		LOG_ERR("Unable to get broadcast ID: %d", err);
+#if defined(CONFIG_STATIC_BROADCAST_ID)
+	broadcast_id = CONFIG_BROADCAST_ID;
+#else
+	err = bt_rand(&broadcast_id, BT_AUDIO_BROADCAST_ID_SIZE);
+	if (err) {
+		printk("Unable to generate broadcast ID: %d\n", err);
 		return err;
 	}
+#endif /* CONFIG_STATIC_BROADCAST_ID */
 
 	/* Setup extended advertising data */
 	net_buf_simple_add_le16(&ad_buf, BT_UUID_BROADCAST_AUDIO_VAL);
diff --git a/samples/bluetooth/pbp_public_broadcast_source/Kconfig b/samples/bluetooth/pbp_public_broadcast_source/Kconfig
@@ -0,0 +1,20 @@
+# Copyright (c) 2024 Demant A/S
+# SPDX-License-Identifier: Apache-2.0
+
+mainmenu "Bluetooth: PBP Broadcast Audio Source"
+
+config STATIC_BROADCAST_ID
+	bool "Use static broadcast ID"
+	default y
+	help
+	   Enabling this option will make the application use static broadcast ID, as opposed to a
+	   randomly generated one.
+
+config BROADCAST_ID
+	hex "The static broadcast ID to use"
+	range 0x000000 0xFFFFFF
+	depends on STATIC_BROADCAST_ID
+	help
+	   This is the 3-octet broadcast ID advertised if static broadcast IDs are enabled.
+
+source "Kconfig.zephyr"
diff --git a/samples/bluetooth/pbp_public_broadcast_source/prj.conf b/samples/bluetooth/pbp_public_broadcast_source/prj.conf
@@ -24,3 +24,4 @@ CONFIG_BT_BAP_BROADCAST_SRC_SUBGROUP_COUNT=1
 
 CONFIG_BT_EXT_ADV=y
 CONFIG_BT_DEVICE_NAME="PBS"
+CONFIG_STATIC_BROADCAST_ID=n
diff --git a/samples/bluetooth/pbp_public_broadcast_source/src/main.c b/samples/bluetooth/pbp_public_broadcast_source/src/main.c
@@ -189,12 +189,15 @@ static int setup_extended_adv_data(struct bt_cap_broadcast_source *source,
 	uint32_t broadcast_id;
 	int err;
 
-	err = bt_cap_initiator_broadcast_get_id(source, &broadcast_id);
-	if (err != 0) {
-		printk("Unable to get broadcast ID: %d\n", err);
-
+#if defined(CONFIG_STATIC_BROADCAST_ID)
+	broadcast_id = CONFIG_BROADCAST_ID;
+#else
+	err = bt_rand(&broadcast_id, BT_AUDIO_BROADCAST_ID_SIZE);
+	if (err) {
+		printk("Unable to generate broadcast ID: %d\n", err);
 		return err;
 	}
+#endif /* CONFIG_STATIC_BROADCAST_ID */
 
 	/* Setup extended advertising data */
 	ext_ad[0].type = BT_DATA_GAP_APPEARANCE;
diff --git a/samples/bluetooth/tmap_bms/src/cap_initiator.c b/samples/bluetooth/tmap_bms/src/cap_initiator.c
@@ -172,9 +172,9 @@ static int setup_extended_adv_data(struct bt_cap_broadcast_source *source,
 	uint32_t broadcast_id;
 	int err;
 
-	err = bt_cap_initiator_broadcast_get_id(source, &broadcast_id);
-	if (err != 0) {
-		printk("Unable to get broadcast ID: %d\n", err);
+	err = bt_rand(&broadcast_id, BT_AUDIO_BROADCAST_ID_SIZE);
+	if (err) {
+		printk("Unable to generate broadcast ID: %d\n", err);
 		return err;
 	}
 
diff --git a/subsys/bluetooth/audio/bap_broadcast_source.c b/subsys/bluetooth/audio/bap_broadcast_source.c
@@ -450,36 +450,6 @@ static bool encode_base(struct bt_bap_broadcast_source *source, struct net_buf_s
 	return true;
 }
 
-static int generate_broadcast_id(struct bt_bap_broadcast_source *source)
-{
-	bool unique;
-
-	do {
-		int err;
-
-		err = bt_rand(&source->broadcast_id,
-			      BT_AUDIO_BROADCAST_ID_SIZE);
-		if (err) {
-			return err;
-		}
-
-		/* Ensure uniqueness */
-		unique = true;
-		for (int i = 0; i < ARRAY_SIZE(broadcast_sources); i++) {
-			if (&broadcast_sources[i] == source) {
-				continue;
-			}
-
-			if (broadcast_sources[i].broadcast_id == source->broadcast_id) {
-				unique = false;
-				break;
-			}
-		}
-	} while (!unique);
-
-	return 0;
-}
-
 static void broadcast_source_cleanup(struct bt_bap_broadcast_source *source)
 {
 	struct bt_bap_broadcast_subgroup *subgroup, *next_subgroup;
@@ -830,12 +800,6 @@ int bt_bap_broadcast_source_create(struct bt_bap_broadcast_source_param *param,
 		}
 	}
 
-	err = generate_broadcast_id(source);
-	if (err != 0) {
-		LOG_DBG("Could not generate broadcast id: %d", err);
-		return err;
-	}
-
 	/* Finalize state changes and store information */
 	broadcast_source_set_state(source, BT_BAP_EP_STATE_QOS_CONFIGURED);
 	source->qos = qos;
@@ -852,8 +816,6 @@ int bt_bap_broadcast_source_create(struct bt_bap_broadcast_source_param *param,
 			     sizeof(source->broadcast_code));
 	}
 
-	LOG_DBG("Broadcasting with ID 0x%6X", source->broadcast_id);
-
 	*out_source = source;
 
 	return 0;
@@ -1197,32 +1159,6 @@ int bt_bap_broadcast_source_delete(struct bt_bap_broadcast_source *source)
 	return 0;
 }
 
-int bt_bap_broadcast_source_get_id(struct bt_bap_broadcast_source *source,
-				   uint32_t *const broadcast_id)
-{
-	enum bt_bap_ep_state broadcast_state;
-
-	CHECKIF(source == NULL) {
-		LOG_DBG("source is NULL");
-		return -EINVAL;
-	}
-
-	CHECKIF(broadcast_id == NULL) {
-		LOG_DBG("broadcast_id is NULL");
-		return -EINVAL;
-	}
-
-	broadcast_state = broadcast_source_get_state(source);
-	if (broadcast_state == BT_BAP_EP_STATE_IDLE) {
-		LOG_DBG("Broadcast source invalid state: %u", broadcast_state);
-		return -EBADMSG;
-	}
-
-	*broadcast_id = source->broadcast_id;
-
-	return 0;
-}
-
 int bt_bap_broadcast_source_get_base(struct bt_bap_broadcast_source *source,
 				     struct net_buf_simple *base_buf)
 {
diff --git a/subsys/bluetooth/audio/bap_endpoint.h b/subsys/bluetooth/audio/bap_endpoint.h
@@ -108,7 +108,6 @@ struct bt_bap_broadcast_source {
 	uint8_t stream_count;
 	uint8_t packing;
 	bool encryption;
-	uint32_t broadcast_id; /* 24 bit */
 
 	struct bt_iso_big *big;
 	struct bt_bap_qos_cfg *qos;
diff --git a/subsys/bluetooth/audio/cap_initiator.c b/subsys/bluetooth/audio/cap_initiator.c
@@ -322,17 +322,6 @@ int bt_cap_initiator_broadcast_audio_delete(struct bt_cap_broadcast_source *broa
 	return err;
 }
 
-int bt_cap_initiator_broadcast_get_id(const struct bt_cap_broadcast_source *broadcast_source,
-				      uint32_t *const broadcast_id)
-{
-	CHECKIF(broadcast_source == NULL) {
-		LOG_DBG("broadcast_source is NULL");
-		return -EINVAL;
-	}
-
-	return bt_bap_broadcast_source_get_id(broadcast_source->bap_broadcast, broadcast_id);
-}
-
 int bt_cap_initiator_broadcast_get_base(struct bt_cap_broadcast_source *broadcast_source,
 					struct net_buf_simple *base_buf)
 {
diff --git a/subsys/bluetooth/audio/shell/bap.c b/subsys/bluetooth/audio/shell/bap.c
@@ -4329,9 +4329,9 @@ static ssize_t nonconnectable_ad_data_add(struct bt_data *data_array,
 		uint32_t broadcast_id;
 		int err;
 
-		err = bt_bap_broadcast_source_get_id(default_source.bap_source, &broadcast_id);
+		err = bt_rand(&broadcast_id, BT_AUDIO_BROADCAST_ID_SIZE);
 		if (err != 0) {
-			printk("Unable to get broadcast ID: %d\n", err);
+			printk("Unable to generate broadcast ID: %d\n", err);
 
 			return -1;
 		}
diff --git a/subsys/bluetooth/audio/shell/cap_initiator.c b/subsys/bluetooth/audio/shell/cap_initiator.c
@@ -1447,9 +1447,9 @@ static ssize_t nonconnectable_ad_data_add(struct bt_data *data_array, const size
 		uint32_t broadcast_id;
 		int err;
 
-		err = bt_cap_initiator_broadcast_get_id(default_source.cap_source, &broadcast_id);
-		if (err != 0) {
-			printk("Unable to get broadcast ID: %d\n", err);
+		err = bt_rand(&broadcast_id, BT_AUDIO_BROADCAST_ID_SIZE);
+		if (err) {
+			printk("Unable to generate broadcast ID: %d\n", err);
 
 			return -1;
 		}
diff --git a/tests/bluetooth/audio/bap_broadcast_source/src/main.c b/tests/bluetooth/audio/bap_broadcast_source/src/main.c
diff --git a/tests/bluetooth/tester/src/audio/btp_bap_broadcast.c b/tests/bluetooth/tester/src/audio/btp_bap_broadcast.c
diff --git a/tests/bluetooth/tester/src/audio/btp_cap.c b/tests/bluetooth/tester/src/audio/btp_cap.c
diff --git a/tests/bsim/bluetooth/audio/src/bap_broadcast_source_test.c b/tests/bsim/bluetooth/audio/src/bap_broadcast_source_test.c
diff --git a/tests/bsim/bluetooth/audio/src/cap_initiator_broadcast_test.c b/tests/bsim/bluetooth/audio/src/cap_initiator_broadcast_test.c
diff --git a/tests/bsim/bluetooth/audio/src/gmap_ugg_test.c b/tests/bsim/bluetooth/audio/src/gmap_ugg_test.c
diff --git a/tests/bsim/bluetooth/audio/src/pbp_public_broadcast_source_test.c b/tests/bsim/bluetooth/audio/src/pbp_public_broadcast_source_test.c

Original file line number	Diff line number	Diff line change
`@@ -14,3 +14,4 @@ CONFIG_BT_ISO_TX_BUF_COUNT=6`
`14`	`14`	`CONFIG_BT_ISO_TX_MTU=60`
`15`	`15`
`16`	`16`	`CONFIG_BT_DEVICE_NAME="Broadcast Audio Source"`
	`17`	`+CONFIG_BROADCAST_ID=0x123456`