This patch adds support for obtaining the characteristic value from an
external application during a read procedure.
---
src/gatt-manager.c | 155 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 153 insertions(+), 2 deletions(-)
diff --git a/src/gatt-manager.c b/src/gatt-manager.c
index 7197197..8c92d79 100644
--- a/src/gatt-manager.c
+++ b/src/gatt-manager.c
@@ -48,6 +48,10 @@
#define UUID_GAP 0x1800
#define UUID_GATT 0x1801
+#ifndef MIN
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
struct btd_gatt_manager {
struct btd_adapter *adapter;
struct gatt_db *db;
@@ -72,8 +76,35 @@ struct external_chrc {
uint8_t props;
uint8_t ext_props;
struct gatt_db_attribute *attrib;
+ struct queue *pending_ops;
+};
+
+struct pending_dbus_op {
+ struct external_chrc *chrc;
+ unsigned int id;
+ void *user_data;
};
+static void cancel_pending_dbus_op(void *data, void *user_data)
+{
+ struct pending_dbus_op *op = data;
+
+ gatt_db_attribute_read_result(op->chrc->attrib, op->id,
+ BT_ATT_ERROR_REQUEST_NOT_SUPPORTED,
+ NULL, 0);
+ op->chrc = NULL;
+}
+
+static void pending_dbus_op_free(void *data)
+{
+ struct pending_dbus_op *op = data;
+
+ if (op->chrc)
+ queue_remove(op->chrc->pending_ops, op);
+
+ free(op);
+}
+
static bool match_service_path(const void *a, const void *b)
{
const struct external_service *service = a;
@@ -86,6 +117,8 @@ static void chrc_free(void *data)
{
struct external_chrc *chrc = data;
+ queue_foreach(chrc->pending_ops, cancel_pending_dbus_op, NULL);
+
if (chrc->proxy)
g_dbus_proxy_unref(chrc->proxy);
@@ -179,6 +212,12 @@ static struct external_chrc *chrc_create(GDBusProxy *proxy)
if (!chrc)
return NULL;
+ chrc->pending_ops = queue_new();
+ if (!chrc->pending_ops) {
+ free(chrc);
+ return NULL;
+ }
+
chrc->proxy = g_dbus_proxy_ref(proxy);
return chrc;
@@ -409,6 +448,117 @@ static bool parse_primary(GDBusProxy *proxy, bool *primary)
return true;
}
+static uint8_t dbus_error_to_att_ecode(const char *error_name)
+{
+ /* TODO: Parse error ATT ecode from error_message */
+
+ if (strcmp(error_name, "org.bluez.Error.Failed") == 0)
+ return 0x80; /* For now return this "application error" */
+
+ if (strcmp(error_name, "org.bluez.Error.NotSupported") == 0)
+ return BT_ATT_ERROR_REQUEST_NOT_SUPPORTED;
+
+ if (strcmp(error_name, "org.bluez.Error.NotAuthorized") == 0)
+ return BT_ATT_ERROR_AUTHORIZATION;
+
+ if (strcmp(error_name, "org.bluez.Error.InvalidValueLength") == 0)
+ return BT_ATT_ERROR_INVALID_ATTRIBUTE_VALUE_LEN;
+
+ return 0;
+}
+
+static void read_reply_cb(DBusMessage *message, void *user_data)
+{
+ struct pending_dbus_op *op = user_data;
+ DBusError err;
+ DBusMessageIter iter, array;
+ uint8_t ecode = 0;
+ uint8_t *value = NULL;
+ int len = 0;
+
+ if (!op->chrc) {
+ DBG("Pending read was canceled when object got removed");
+ return;
+ }
+
+ dbus_error_init(&err);
+
+ if (dbus_set_error_from_message(&err, message) == TRUE) {
+ DBG("Failed to read value: %s: %s", err.name, err.message);
+ ecode = dbus_error_to_att_ecode(err.name);
+ ecode = ecode ? ecode : BT_ATT_ERROR_READ_NOT_PERMITTED;
+ dbus_error_free(&err);
+ goto done;
+ }
+
+ dbus_message_iter_init(message, &iter);
+
+ if (dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY) {
+ /*
+ * Return not supported for this, as the external app basically
+ * doesn't properly support reading from this characteristic.
+ */
+ ecode = BT_ATT_ERROR_REQUEST_NOT_SUPPORTED;
+ error("Invalid return value received for \"ReadValue\"");
+ goto done;
+ }
+
+ dbus_message_iter_recurse(&iter, &array);
+ dbus_message_iter_get_fixed_array(&array, &value, &len);
+
+ if (len < 0) {
+ ecode = BT_ATT_ERROR_REQUEST_NOT_SUPPORTED;
+ value = NULL;
+ len = 0;
+ goto done;
+ }
+
+ /* Truncate the value if it's too large */
+ len = MIN(BT_ATT_MAX_VALUE_LEN, len);
+ value = len ? value : NULL;
+
+done:
+ gatt_db_attribute_read_result(op->chrc->attrib, op->id, ecode,
+ value, len);
+}
+
+static void chrc_read_cb(struct gatt_db_attribute *attrib,
+ unsigned int id, uint16_t offset,
+ uint8_t opcode, struct bt_att *att,
+ void *user_data)
+{
+ struct external_chrc *chrc = user_data;
+ struct pending_dbus_op *op;
+ uint8_t ecode = BT_ATT_ERROR_UNLIKELY;
+
+ if (chrc->attrib != attrib) {
+ error("Read callback called with incorrect attribute");
+ goto error;
+
+ }
+
+ op = new0(struct pending_dbus_op, 1);
+ if (!op) {
+ error("Failed to allocate memory for pending read call");
+ ecode = BT_ATT_ERROR_INSUFFICIENT_RESOURCES;
+ goto error;
+ }
+
+ op->chrc = chrc;
+ op->id = id;
+ queue_push_tail(chrc->pending_ops, op);
+
+ if (g_dbus_proxy_method_call(chrc->proxy, "ReadValue", NULL,
+ read_reply_cb, op,
+ pending_dbus_op_free) == TRUE)
+ return;
+
+ pending_dbus_op_free(op);
+
+error:
+ gatt_db_attribute_read_result(attrib, id, ecode, NULL, 0);
+}
+
static bool create_chrc_entry(struct external_service *service,
struct external_chrc *chrc)
{
@@ -425,10 +575,11 @@ static bool create_chrc_entry(struct external_service *service,
return false;
}
- /* TODO: Assign permissions and read/write callbacks */
+ /* TODO: Assign permissions and write callback */
chrc->attrib = gatt_db_service_add_characteristic(service->attrib,
&uuid, 0, chrc->props,
- NULL, NULL, NULL);
+ chrc_read_cb,
+ NULL, chrc);
/* TODO: Create descriptor entries */
--
2.2.0.rc0.207.ga3a616c
--
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