From 9dbe776338e7f97483452cc00adf0d527d6900dd Mon Sep 17 00:00:00 2001 From: Christophe Ricard Date: Tue, 31 Mar 2015 08:02:23 +0200 Subject: [PATCH] nfc: st21nfca: Add additional comments about EVT_TRANSACTION Add comments about HCI EVT_TRANSACTION in order to make the code understandable by other readers. Signed-off-by: Christophe Ricard Signed-off-by: Samuel Ortiz --- drivers/nfc/st21nfca/st21nfca_se.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/nfc/st21nfca/st21nfca_se.c b/drivers/nfc/st21nfca/st21nfca_se.c index bd13cac9c66a..3197e9bb66f7 100644 --- a/drivers/nfc/st21nfca/st21nfca_se.c +++ b/drivers/nfc/st21nfca/st21nfca_se.c @@ -310,6 +310,13 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host, case ST21NFCA_EVT_CONNECTIVITY: break; case ST21NFCA_EVT_TRANSACTION: + /* + * According to specification etsi 102 622 + * 11.2.2.4 EVT_TRANSACTION Table 52 + * Description Tag Length + * AID 81 5 to 16 + * PARAMETERS 82 0 to 255 + */ if (skb->len < NFC_MIN_AID_LENGTH + 2 && skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG) return -EPROTO; @@ -318,8 +325,10 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host, skb->len - 2, GFP_KERNEL); transaction->aid_len = skb->data[1]; - memcpy(transaction->aid, &skb->data[2], skb->data[1]); + memcpy(transaction->aid, &skb->data[2], + transaction->aid_len); + /* Check next byte is PARAMETERS tag (82) */ if (skb->data[transaction->aid_len + 2] != NFC_EVT_TRANSACTION_PARAMS_TAG) return -EPROTO; -- 2.20.1