NFC: digital: Add NFC-DEP Target-side NACK Support
When an NFC-DEP Target receives a NACK PDU with
a PNI equal to 1 less than the current PNI, it
is supposed to re-send the last PDU. This is
implied in section 14.12.5.4 of the NFC Digital
Protocol Spec.
The digital layer's NFC-DEP code doesn't implement
Target-side NACK handing so add it. The last PDU
that was sent is saved in the 'nfc_digital_dev'
structure's 'saved_skb' member. The skb will have
an additional reference taken to ensure that the skb
isn't freed when the driver performs a kfree_skb()
on the skb. The length of the skb/PDU is also saved
so the length can be restored when re-sending the PDU
in the skb (the driver will perform an skb_pull() so
an skb_push() needs to be done to restore the skb's
data pointer/length).
Reviewed-by: Thierry Escande <[email protected]>
Tested-by: Thierry Escande <[email protected]>
Signed-off-by: Mark A. Greer <[email protected]>
Signed-off-by: Samuel Ortiz <[email protected]>
diff --git a/include/net/nfc/digital.h b/include/net/nfc/digital.h
index 2fd498c..7400a81 100644
--- a/include/net/nfc/digital.h
+++ b/include/net/nfc/digital.h
@@ -235,6 +235,9 @@
int nack_count;
+ struct sk_buff *saved_skb;
+ unsigned int saved_skb_len;
+
u16 target_fsc;
int (*skb_check_crc)(struct sk_buff *skb);
