return ERR_PTR(-ENOMEM);
}
- skb_reserve(new_skb, ddev->tx_headroom + NFC_HEADER_SIZE +
- DIGITAL_NFC_DEP_REQ_RES_HEADROOM);
memcpy(skb_put(new_skb, ddev->remote_payload_max), skb->data,
ddev->remote_payload_max);
skb_pull(skb, ddev->remote_payload_max);
break;
case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
+ if (DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) {
+ PROTOCOL_ERR("14.12.4.5");
+ rc = -EIO;
+ goto exit;
+ }
+
if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
PROTOCOL_ERR("14.12.3.3");
rc = -EIO;
ddev->curr_nfc_dep_pni =
DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
- if (ddev->chaining_skb && !DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) {
- kfree_skb(ddev->saved_skb);
- ddev->saved_skb = NULL;
+ if (!ddev->chaining_skb) {
+ PROTOCOL_ERR("14.12.4.3");
+ rc = -EIO;
+ goto exit;
+ }
- rc = digital_in_send_dep_req(ddev, NULL,
- ddev->chaining_skb,
- ddev->data_exch);
- if (rc)
- goto error;
+ /* The initiator has received a valid ACK. Free the last sent
+ * PDU and keep on sending chained skb.
+ */
+ kfree_skb(ddev->saved_skb);
+ ddev->saved_skb = NULL;
- return;
- }
+ rc = digital_in_send_dep_req(ddev, NULL,
+ ddev->chaining_skb,
+ ddev->data_exch);
+ if (rc)
+ goto error;
- pr_err("Received a ACK/NACK PDU\n");
- rc = -EINVAL;
- goto exit;
+ goto free_resp;
case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
if (!DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) { /* ATN */
if (rc)
kfree_skb(resp);
+
+ return;
+
+free_resp:
+ dev_kfree_skb(resp);
}
int digital_in_send_dep_req(struct nfc_digital_dev *ddev,
case DIGITAL_NFC_DEP_PFB_I_PDU:
pr_debug("DIGITAL_NFC_DEP_PFB_I_PDU\n");
- if ((ddev->atn_count && (DIGITAL_NFC_DEP_PFB_PNI(pfb - 1) !=
- ddev->curr_nfc_dep_pni)) ||
- (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni)) {
- PROTOCOL_ERR("14.12.3.4");
- rc = -EIO;
- goto exit;
- }
-
if (ddev->atn_count) {
+ /* The target has received (and replied to) at least one
+ * ATN DEP_REQ.
+ */
ddev->atn_count = 0;
- rc = digital_tg_send_saved_skb(ddev);
- if (rc)
- goto exit;
+ /* pni of resp PDU equal to the target current pni - 1
+ * means resp is the previous DEP_REQ PDU received from
+ * the initiator so the target replies with saved_skb
+ * which is the previous DEP_RES saved in
+ * digital_tg_send_dep_res().
+ */
+ if (DIGITAL_NFC_DEP_PFB_PNI(pfb) ==
+ DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni - 1)) {
+ rc = digital_tg_send_saved_skb(ddev);
+ if (rc)
+ goto exit;
- return;
+ goto free_resp;
+ }
+
+ /* atn_count > 0 and PDU pni != curr_nfc_dep_pni - 1
+ * means the target probably did not received the last
+ * DEP_REQ PDU sent by the initiator. The target
+ * fallbacks to normal processing then.
+ */
+ }
+
+ if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
+ PROTOCOL_ERR("14.12.3.4");
+ rc = -EIO;
+ goto exit;
}
kfree_skb(ddev->saved_skb);
rc = 0;
break;
case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
- if (!DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) { /* ACK */
- if ((ddev->atn_count &&
- (DIGITAL_NFC_DEP_PFB_PNI(pfb - 1) !=
- ddev->curr_nfc_dep_pni)) ||
- (DIGITAL_NFC_DEP_PFB_PNI(pfb) !=
- ddev->curr_nfc_dep_pni) ||
- !ddev->chaining_skb || !ddev->saved_skb) {
+ if (DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) { /* NACK */
+ if (DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) !=
+ ddev->curr_nfc_dep_pni) {
rc = -EIO;
goto exit;
}
- if (ddev->atn_count) {
- ddev->atn_count = 0;
+ ddev->atn_count = 0;
+
+ rc = digital_tg_send_saved_skb(ddev);
+ if (rc)
+ goto exit;
+ goto free_resp;
+ }
+
+ /* ACK */
+ if (ddev->atn_count) {
+ /* The target has previously recevied one or more ATN
+ * PDUs.
+ */
+ ddev->atn_count = 0;
+
+ /* If the ACK PNI is equal to the target PNI - 1 means
+ * that the initiator did not receive the previous PDU
+ * sent by the target so re-send it.
+ */
+ if (DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) ==
+ ddev->curr_nfc_dep_pni) {
rc = digital_tg_send_saved_skb(ddev);
if (rc)
goto exit;
- return;
+ goto free_resp;
}
- kfree_skb(ddev->saved_skb);
- ddev->saved_skb = NULL;
+ /* Otherwise, the target did not receive the previous
+ * ACK PDU from the initiator. Fallback to normal
+ * processing of chained PDU then.
+ */
+ }
- rc = digital_tg_send_dep_res(ddev, ddev->chaining_skb);
- if (rc)
- goto exit;
- } else { /* NACK */
- if ((DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) !=
- ddev->curr_nfc_dep_pni) ||
- !ddev->saved_skb) {
- rc = -EIO;
- goto exit;
- }
+ /* Keep on sending chained PDU */
+ if (!ddev->chaining_skb ||
+ DIGITAL_NFC_DEP_PFB_PNI(pfb) !=
+ ddev->curr_nfc_dep_pni) {
+ rc = -EIO;
+ goto exit;
+ }
- ddev->atn_count = 0;
+ kfree_skb(ddev->saved_skb);
+ ddev->saved_skb = NULL;
- rc = digital_tg_send_saved_skb(ddev);
- if (rc)
- goto exit;
- }
+ rc = digital_tg_send_dep_res(ddev, ddev->chaining_skb);
+ if (rc)
+ goto exit;
- return;
+ goto free_resp;
case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
if (DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) {
rc = -EINVAL;
if (rc)
kfree_skb(resp);
+
+ return;
+
+free_resp:
+ dev_kfree_skb(resp);
}
int digital_tg_send_dep_res(struct nfc_digital_dev *ddev, struct sk_buff *skb)
projects / karo-tx-linux.git / blobdiff