Return-Path: From: Arman Uguray To: linux-bluetooth@vger.kernel.org Cc: Arman Uguray Subject: [PATCH BlueZ v2 07/16] core: gatt: Support ReadValue for characteristics Date: Fri, 27 Feb 2015 00:16:30 -0800 Message-Id: <1425024999-29789-8-git-send-email-armansito@chromium.org> In-Reply-To: <1425024999-29789-1-git-send-email-armansito@chromium.org> References: <1425024999-29789-1-git-send-email-armansito@chromium.org> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: 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