[Bluez,06/10] advertising: Expose SupportedCapabilities for advertising

Commit Message

Daniel Winkler Sept. 16, 2020, 11:25 p.m. UTC

To help our advertising clients understand the device capabilities, this
patch adds a SupportedCapabilities dbus endpoint for the advertising
manager. The primary reason behind this is to provide the valid LE tx
power range the controller supports (populated if controller supports
BT5), so a client can know the valid power range before requesting a tx
power for their advertisement.

I also thought it would be useful to indicate the max advertising data
length and scan response length in this endpoint, since some clients
will find it useful to set their advertising data (currently
experimental feature) or scan response data (possible future feature)
directly.

This patch has been tested on Hatch (BT5 support) and Kukui (No BT5
support) chromebooks to verify that the dbus endpoint contains the
correct data.

Reviewed-by: Sonny Sasaka <[e-mail]>
---

 lib/mgmt.h        |  4 ++--
 src/advertising.c | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 2 deletions(-)

Patch

diff --git a/lib/mgmt.h b/lib/mgmt.h
index dbabb513f..5f752ecd5 100644
--- a/lib/mgmt.h
+++ b/lib/mgmt.h
@@ -744,8 +744,8 @@  struct mgmt_rp_add_ext_adv_data {
 	uint8_t	instance;
 } __packed;
 
-#define MGMT_CAP_LE_TX_PWR_MIN	0x0001
-#define MGMT_CAP_LE_TX_PWR_MAX	0x0002
+#define MGMT_CAP_LE_TX_PWR_MIN	0x0000
+#define MGMT_CAP_LE_TX_PWR_MAX	0x0001
 
 #define MGMT_OP_READ_CONTROLLER_CAP	0x0056
 struct mgmt_rp_read_controller_cap {
diff --git a/src/advertising.c b/src/advertising.c
index 02aa11934..df7436b1d 100644
--- a/src/advertising.c
+++ b/src/advertising.c
@@ -1624,12 +1624,46 @@  static gboolean get_supported_secondary(const GDBusPropertyTable *property,
 	return TRUE;
 }
 
+static gboolean get_supported_cap(const GDBusPropertyTable *property,
+					DBusMessageIter *iter, void *data)
+{
+	struct btd_adv_manager *manager = data;
+	DBusMessageIter dict;
+	int16_t min_tx_power = manager->min_tx_power;
+	int16_t max_tx_power = manager->max_tx_power;
+
+	dbus_message_iter_open_container(iter, DBUS_TYPE_ARRAY,
+					DBUS_DICT_ENTRY_BEGIN_CHAR_AS_STRING
+					DBUS_TYPE_STRING_AS_STRING
+					DBUS_TYPE_VARIANT_AS_STRING
+					DBUS_DICT_ENTRY_END_CHAR_AS_STRING,
+					&dict);
+
+	if (min_tx_power != ADV_TX_POWER_NO_PREFERENCE)
+		dict_append_entry(&dict, "MinTxPower", DBUS_TYPE_INT16,
+				&min_tx_power);
+
+	if (max_tx_power != ADV_TX_POWER_NO_PREFERENCE)
+		dict_append_entry(&dict, "MaxTxPower", DBUS_TYPE_INT16,
+				&max_tx_power);
+
+	dict_append_entry(&dict, "MaxAdvLen", DBUS_TYPE_BYTE,
+			&manager->max_adv_len);
+	dict_append_entry(&dict, "MaxScnRspLen", DBUS_TYPE_BYTE,
+			&manager->max_scan_rsp_len);
+
+	dbus_message_iter_close_container(iter, &dict);
+
+	return TRUE;
+}
+
 static const GDBusPropertyTable properties[] = {
 	{ "ActiveInstances", "y", get_active_instances, NULL, NULL },
 	{ "SupportedInstances", "y", get_instances, NULL, NULL },
 	{ "SupportedIncludes", "as", get_supported_includes, NULL, NULL },
 	{ "SupportedSecondaryChannels", "as", get_supported_secondary, NULL,
 							secondary_exits },
+	{ "SupportedCapabilities", "a{sv}", get_supported_cap, NULL, NULL},
 	{ }
 };