static int process_state_fw_dnld()

in nfcmrvl/fw_dnld.c [247:346]

• 84 lines of code
• 18 McCabe index (conditional complexity)

static int process_state_fw_dnld(struct nfcmrvl_private *priv,
				 struct sk_buff *skb)
{
	uint16_t len;
	uint16_t comp_len;
	struct sk_buff *out_skb;

	switch (priv->fw_dnld.substate) {
	case SUBSTATE_WAIT_COMMAND:
		/*
		 * Command format:
		 * B0..2: NCI header
		 * B3   : Helper command (0xA5)
		 * B4..5: le16 data size
		 * B6..7: le16 data size complement (~)
		 * B8..N: payload
		 */

		/* Remove NCI HDR */
		skb_pull(skb, 3);
		if (skb->data[0] != HELPER_CMD_PACKET_FORMAT || skb->len != 5) {
			nfc_err(priv->dev, "bad command");
			return -EINVAL;
		}
		skb_pull(skb, 1);
		len = get_unaligned_le16(skb->data);
		skb_pull(skb, 2);
		comp_len = get_unaligned_le16(skb->data);
		memcpy(&comp_len, skb->data, 2);
		skb_pull(skb, 2);
		if (((~len) & 0xFFFF) != comp_len) {
			nfc_err(priv->dev, "bad len complement: %x %x %x",
				len, comp_len, (~len & 0xFFFF));
			out_skb = alloc_lc_skb(priv, 1);
			if (!out_skb)
				return -ENOMEM;
			skb_put_u8(out_skb, 0xBF);
			nci_send_frame(priv->ndev, out_skb);
			priv->fw_dnld.substate = SUBSTATE_WAIT_NACK_CREDIT;
			return 0;
		}
		priv->fw_dnld.chunk_len = len;
		out_skb = alloc_lc_skb(priv, 1);
		if (!out_skb)
			return -ENOMEM;
		skb_put_u8(out_skb, HELPER_ACK_PACKET_FORMAT);
		nci_send_frame(priv->ndev, out_skb);
		priv->fw_dnld.substate = SUBSTATE_WAIT_ACK_CREDIT;
		break;

	case SUBSTATE_WAIT_ACK_CREDIT:
		if (sizeof(nci_pattern_core_conn_credits_ntf) != skb->len ||
		    memcmp(nci_pattern_core_conn_credits_ntf, skb->data,
			   skb->len)) {
			nfc_err(priv->dev, "bad packet: waiting for credit");
			return -EINVAL;
		}
		if (priv->fw_dnld.chunk_len == 0) {
			/* FW Loading is done */
			uint8_t conn_id = NCI_CORE_LC_CONNID_PROP_FW_DL;

			priv->fw_dnld.state = STATE_CLOSE_LC;
			nci_send_cmd(priv->ndev, NCI_OP_CORE_CONN_CLOSE_CMD,
				     1, &conn_id);
		} else {
			out_skb = alloc_lc_skb(priv, priv->fw_dnld.chunk_len);
			if (!out_skb)
				return -ENOMEM;
			skb_put_data(out_skb,
				     ((uint8_t *)priv->fw_dnld.fw->data) + priv->fw_dnld.offset,
				     priv->fw_dnld.chunk_len);
			nci_send_frame(priv->ndev, out_skb);
			priv->fw_dnld.substate = SUBSTATE_WAIT_DATA_CREDIT;
		}
		break;

	case SUBSTATE_WAIT_DATA_CREDIT:
		if (sizeof(nci_pattern_core_conn_credits_ntf) != skb->len ||
		    memcmp(nci_pattern_core_conn_credits_ntf, skb->data,
			    skb->len)) {
			nfc_err(priv->dev, "bad packet: waiting for credit");
			return -EINVAL;
		}
		priv->fw_dnld.offset += priv->fw_dnld.chunk_len;
		priv->fw_dnld.chunk_len = 0;
		priv->fw_dnld.substate = SUBSTATE_WAIT_COMMAND;
		break;

	case SUBSTATE_WAIT_NACK_CREDIT:
		if (sizeof(nci_pattern_core_conn_credits_ntf) != skb->len ||
		    memcmp(nci_pattern_core_conn_credits_ntf, skb->data,
			    skb->len)) {
			nfc_err(priv->dev, "bad packet: waiting for credit");
			return -EINVAL;
		}
		priv->fw_dnld.substate = SUBSTATE_WAIT_COMMAND;
		break;
	}
	return 0;
}