shared/gatt-db: Add high-level functions for client

This patch introduces foreach functions to gatt-db for enumerating
service, characteristic, and decriptors stored in the database as
gatt_db_attribute pointers. This patch also adds functions for
extracting service, characteristic, and include declaration data out of
matching attributes.

This is in preparation for using gatt-db as the attribute cache in
shared/gatt-client.

2 files changed, 291 insertions, 0 deletions

diff --git a/src/shared/gatt-db.c b/src/shared/gatt-db.c
index ab08c6989..fe055954b 100644
--- a/src/shared/gatt-db.c
+++ b/src/shared/gatt-db.c
@@ -193,6 +193,29 @@ static int uuid_to_le(const bt_uuid_t *uuid, uint8_t *dst)
 	return bt_uuid_len(&uuid128);
 }
 
+static bool le_to_uuid(const uint8_t *src, size_t len, bt_uuid_t *uuid)
+{
+	uint128_t u128;
+
+	if (len == 2) {
+		bt_uuid16_create(uuid, get_le16(src));
+		return true;
+	}
+
+	if (len == 4) {
+		bt_uuid32_create(uuid, get_le32(src));
+		return true;
+	}
+
+	if (len != 16)
+		return false;
+
+	bswap_128(src, &u128);
+	bt_uuid128_create(uuid, u128);
+
+	return true;
+}
+
 struct gatt_db_attribute *gatt_db_add_service(struct gatt_db *db,
 						const bt_uuid_t *uuid,
 						bool primary,
@@ -665,6 +688,125 @@ void gatt_db_find_information(struct gatt_db *db, uint16_t start_handle,
 	queue_foreach(db->services, find_information, &data);
 }
 
+void gatt_db_foreach_service(struct gatt_db *db, gatt_db_foreach_t func,
+							void *user_data)
+{
+	gatt_db_foreach_service_in_range(db, func, user_data, 0x0001, 0xffff);
+}
+
+struct foreach_data {
+	gatt_db_foreach_t func;
+	void *user_data;
+	uint16_t start, end;
+};
+
+static void foreach_service_in_range(void *data, void *user_data)
+{
+	struct gatt_db_service *service = data;
+	struct foreach_data *foreach_data = user_data;
+	uint16_t svc_start;
+
+	svc_start = get_handle_at_index(service, 0);
+
+	if (svc_start > foreach_data->end || svc_start < foreach_data->start)
+		return;
+
+	foreach_data->func(service->attributes[0], foreach_data->user_data);
+}
+
+void gatt_db_foreach_service_in_range(struct gatt_db *db,
+							gatt_db_foreach_t func,
+							void *user_data,
+							uint16_t start_handle,
+							uint16_t end_handle)
+{
+	struct foreach_data data;
+
+	if (!db || !func || start_handle > end_handle)
+		return;
+
+	data.func = func;
+	data.user_data = user_data;
+	data.start = start_handle;
+	data.end = end_handle;
+
+	queue_foreach(db->services, foreach_service_in_range, &data);
+}
+
+void gatt_db_service_foreach(struct gatt_db_attribute *attrib,
+							const bt_uuid_t *uuid,
+							gatt_db_foreach_t func,
+							void *user_data)
+{
+	struct gatt_db_service *service;
+	struct gatt_db_attribute *attr;
+	uint16_t i;
+
+	if (!attrib || !func)
+		return;
+
+	service = attrib->service;
+
+	for (i = 0; i < service->num_handles; i++) {
+		attr = service->attributes[i];
+		if (!attr)
+			continue;
+
+		if (uuid && bt_uuid_cmp(uuid, &attr->uuid))
+			continue;
+
+		func(attr, user_data);
+	}
+}
+
+void gatt_db_service_foreach_char(struct gatt_db_attribute *attrib,
+							gatt_db_foreach_t func,
+							void *user_data)
+{
+	gatt_db_service_foreach(attrib, &characteristic_uuid, func, user_data);
+}
+
+void gatt_db_service_foreach_desc(struct gatt_db_attribute *attrib,
+							gatt_db_foreach_t func,
+							void *user_data)
+{
+	struct gatt_db_service *service;
+	struct gatt_db_attribute *attr;
+	uint16_t i;
+
+	if (!attrib || !func)
+		return;
+
+	/* Return if this attribute is not a characteristic declaration */
+	if (bt_uuid_cmp(&characteristic_uuid, &attrib->uuid))
+		return;
+
+	service = attrib->service;
+
+	/* Start from the attribute following the value handle */
+	i = attrib->handle - service->attributes[0]->handle + 2;
+	for (; i < service->num_handles; i++) {
+		attr = service->attributes[i];
+		if (!attr)
+			continue;
+
+		/* Return if we reached the end of this characteristic */
+		if (!bt_uuid_cmp(&characteristic_uuid, &attr->uuid) ||
+			!bt_uuid_cmp(&included_service_uuid, &attr->uuid))
+			return;
+
+		func(attr, user_data);
+	}
+}
+
+void gatt_db_service_foreach_incl(struct gatt_db_attribute *attrib,
+							gatt_db_foreach_t func,
+							void *user_data)
+{
+	gatt_db_service_foreach(attrib, &included_service_uuid, func,
+								user_data);
+}
+
 static bool find_service_for_handle(const void *data, const void *user_data)
 {
 	const struct gatt_db_service *service = data;
@@ -769,6 +911,113 @@ bool gatt_db_attribute_get_service_handles(struct gatt_db_attribute *attrib,
 	return true;
 }
 
+bool gatt_db_attribute_get_service_data(struct gatt_db_attribute *attrib,
+							uint16_t *start_handle,
+							uint16_t *end_handle,
+							bool *primary,
+							bt_uuid_t *uuid)
+{
+	struct gatt_db_service *service;
+	struct gatt_db_attribute *decl;
+
+	if (!attrib)
+		return false;
+
+	service = attrib->service;
+	decl = service->attributes[0];
+
+	if (start_handle)
+		*start_handle = decl->handle;
+
+	if (end_handle)
+		*end_handle = decl->handle + service->num_handles - 1;
+
+	if (primary)
+		*primary = bt_uuid_cmp(&decl->uuid, &secondary_service_uuid);
+
+	if (!uuid)
+		return true;
+
+	/*
+	 * The service declaration attribute value is the 16 or 128 bit service
+	 * UUID.
+	 */
+	return le_to_uuid(decl->value, decl->value_len, uuid);
+}
+
+bool gatt_db_attribute_get_char_data(struct gatt_db_attribute *attrib,
+							uint16_t *handle,
+							uint16_t *value_handle,
+							uint8_t *properties,
+							bt_uuid_t *uuid)
+{
+	if (!attrib)
+		return false;
+
+	if (bt_uuid_cmp(&characteristic_uuid, &attrib->uuid))
+		return false;
+
+	/*
+	 * Characteristic declaration value:
+	 * 1 octet: Characteristic properties
+	 * 2 octets: Characteristic value handle
+	 * 2 or 16 octets: characteristic UUID
+	 */
+	if (!attrib->value || (attrib->value_len != 5 &&
+						attrib->value_len != 19))
+		return false;
+
+	if (handle)
+		*handle = attrib->handle;
+
+	if (properties)
+		*properties = attrib->value[0];
+
+	if (value_handle)
+		*value_handle = get_le16(attrib->value + 1);
+
+	if (!uuid)
+		return true;
+
+	return le_to_uuid(attrib->value + 3, attrib->value_len - 3, uuid);
+}
+
+bool gatt_db_attribute_get_incl_data(struct gatt_db_attribute *attrib,
+							uint16_t *handle,
+							uint16_t *start_handle,
+							uint16_t *end_handle)
+{
+	if (!attrib)
+		return false;
+
+	if (bt_uuid_cmp(&included_service_uuid, &attrib->uuid))
+		return false;
+
+	/*
+	 * Include definition value:
+	 * 2 octets: start handle of included service
+	 * 2 octets: end handle of included service
+	 * optional 2 octets: 16-bit Bluetooth UUID
+	 */
+	if (!attrib->value || attrib->value_len < 4 || attrib->value_len > 6)
+		return false;
+
+	/*
+	 * We only return the handles since the UUID can be easily obtained
+	 * from the corresponding attribute.
+	 */
+	if (handle)
+		*handle = attrib->handle;
+
+	if (start_handle)
+		*start_handle = get_le16(attrib->value);
+
+	if (end_handle)
+		*end_handle = get_le16(attrib->value + 2);
+
+	return true;
+}
+
 bool gatt_db_attribute_get_permissions(struct gatt_db_attribute *attrib,
 							uint32_t *permissions)
 {
diff --git a/src/shared/gatt-db.h b/src/shared/gatt-db.h
index 9c71814b1..c943ad253 100644
--- a/src/shared/gatt-db.h
+++ b/src/shared/gatt-db.h
@@ -89,6 +89,31 @@ void gatt_db_find_information(struct gatt_db *db, uint16_t start_handle,
 							struct queue *queue);
 
 
+typedef void (*gatt_db_foreach_t)(struct gatt_db_attribute *attrib,
+							void *user_data);
+void gatt_db_foreach_service(struct gatt_db *db, gatt_db_foreach_t func,
+							void *user_data);
+void gatt_db_foreach_service_in_range(struct gatt_db *db,
+							gatt_db_foreach_t func,
+							void *user_data,
+							uint16_t start_handle,
+							uint16_t end_handle);
+
+void gatt_db_service_foreach(struct gatt_db_attribute *attrib,
+							const bt_uuid_t *uuid,
+							gatt_db_foreach_t func,
+							void *user_data);
+void gatt_db_service_foreach_char(struct gatt_db_attribute *attrib,
+							gatt_db_foreach_t func,
+							void *user_data);
+void gatt_db_service_foreach_desc(struct gatt_db_attribute *attrib,
+							gatt_db_foreach_t func,
+							void *user_data);
+void gatt_db_service_foreach_incl(struct gatt_db_attribute *attrib,
+							gatt_db_foreach_t func,
+							void *user_data);
+
+
 struct gatt_db_attribute *gatt_db_get_attribute(struct gatt_db *db,
 							uint16_t handle);
 
@@ -103,6 +128,23 @@ bool gatt_db_attribute_get_service_handles(struct gatt_db_attribute *attrib,
 						uint16_t *start_handle,
 						uint16_t *end_handle);
 
+bool gatt_db_attribute_get_service_data(struct gatt_db_attribute *attrib,
+							uint16_t *start_handle,
+							uint16_t *end_handle,
+							bool *primary,
+							bt_uuid_t *uuid);
+
+bool gatt_db_attribute_get_char_data(struct gatt_db_attribute *attrib,
+							uint16_t *handle,
+							uint16_t *value_handle,
+							uint8_t *properties,
+							bt_uuid_t *uuid);
+
+bool gatt_db_attribute_get_incl_data(struct gatt_db_attribute *attrib,
+							uint16_t *handle,
+							uint16_t *start_handle,
+							uint16_t *end_handle);
+
 bool gatt_db_attribute_get_permissions(struct gatt_db_attribute *attrib,
 							uint32_t *permissions);