NFC: digital: Ensure no NAD byte in DEP_REQ and DEP_RES frames

According to chapter 14 of the NFC-DEP Digital
Protocol Spec., the NAD byte should never be
present in DEP_REQ or DEP_RES frames.  However,
this is not enforced so add that enforcement code.

Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

diff --git a/net/nfc/digital_dep.c b/net/nfc/digital_dep.c
index 7d1c794556c3f4a3e4dbf97f5b9a41c6ab00d7ae..d5e669b0dedf2b4d3db9bf79a6fcb0b42b05c9c0 100644 (file)
--- a/net/nfc/digital_dep.c
+++ b/net/nfc/digital_dep.c
@@ -420,6 +420,11 @@ static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
                goto error;
        }
 
+       if (DIGITAL_NFC_DEP_NAD_BIT_SET(pfb)) {
+               rc = -EIO;
+               goto exit;
+       }
+
        if (size > resp->len) {
                rc = -EIO;
                goto error;
@@ -572,6 +577,11 @@ static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
                goto exit;
        }
 
+       if (DIGITAL_NFC_DEP_NAD_BIT_SET(pfb)) {
+               rc = -EIO;
+               goto exit;
+       }
+
        if (size > resp->len) {
                rc = -EIO;
                goto exit;