nimble/host: Set length correctly in periodic_set_adv_data

   This change sets length field only if data is non NULL, else sets
   length to zero.

nimble/host/src/ble_gap.c

@@ -3711,41 +3711,55 @@ ble_gap_periodic_adv_set(uint8_t instance, struct os_mbuf **data)
  static uint8_t buf[sizeof(struct ble_hci_le_set_periodic_adv_data_cp) +
  MYNEWT_VAL(BLE_EXT_ADV_MAX_SIZE)];
  struct ble_hci_le_set_periodic_adv_data_cp *cmd = (void *) buf;
- uint16_t len = OS_MBUF_PKTLEN(*data);
+ uint16_t len = 0;
  uint16_t opcode;
 
+ if (*data) {
+ len = OS_MBUF_PKTLEN(*data);
+ }
+
  opcode = BLE_HCI_OP(BLE_HCI_OGF_LE, BLE_HCI_OCF_LE_SET_PERIODIC_ADV_DATA);
 
  cmd->adv_handle = instance;
  cmd->operation = BLE_HCI_LE_SET_DATA_OPER_COMPLETE;
  cmd->adv_data_len = len;
- os_mbuf_copydata(*data, 0, len, cmd->adv_data);
 
- os_mbuf_adj(*data, len);
- *data = os_mbuf_trim_front(*data);
+ if (len) {
+ os_mbuf_copydata(*data, 0, len, cmd->adv_data);
+
+ os_mbuf_adj(*data, len);
+ *data = os_mbuf_trim_front(*data);
+ }
 
  return ble_hs_hci_cmd_tx(opcode, cmd, sizeof(*cmd) + cmd->adv_data_len,
  NULL, 0);
 #else
  static uint8_t buf[sizeof(struct ble_hci_le_set_periodic_adv_data_cp) +
  BLE_HCI_MAX_PERIODIC_ADV_DATA_LEN];
  struct ble_hci_le_set_periodic_adv_data_cp *cmd = (void *) buf;
- uint16_t len = OS_MBUF_PKTLEN(*data);
+ uint16_t len = 0;
  uint16_t opcode;
  uint8_t op;
  int rc;
 
+ if (*data) {
+ len = OS_MBUF_PKTLEN(*data);
+ }
+
  opcode = BLE_HCI_OP(BLE_HCI_OGF_LE, BLE_HCI_OCF_LE_SET_PERIODIC_ADV_DATA);
  cmd->adv_handle = instance;
 
  /* Complete data */
  if (len <= BLE_HCI_MAX_PERIODIC_ADV_DATA_LEN) {
  cmd->operation = BLE_HCI_LE_SET_DATA_OPER_COMPLETE;
  cmd->adv_data_len = len;
- os_mbuf_copydata(*data, 0, len, cmd->adv_data);
 
- os_mbuf_adj(*data, len);
- *data = os_mbuf_trim_front(*data);
+ if (len) {
+ os_mbuf_copydata(*data, 0, len, cmd->adv_data);
+
+ os_mbuf_adj(*data, len);
+ *data = os_mbuf_trim_front(*data);
+ }
 
  return ble_hs_hci_cmd_tx(opcode, cmd, sizeof(*cmd) + cmd->adv_data_len,
  NULL, 0);