NFC: digital: Enforce NFC-DEP PNI sequencing
NFC-DEP DEP_REQ and DEP_RES exchanges using 'I'
and 'ACK/NACK' PDUs have a sequence number called
the Packet Number Information (PNI). The PNI
is incremented (modulo 4) after every DEP_REQ/
DEP_RES pair and should be verified by the digital
layer code. That verification isn't always done,
though, so add code to make sure that it is done.
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 d5e669b..95a6989 100644
--- a/net/nfc/digital_dep.c
+++ b/net/nfc/digital_dep.c
@@ -447,8 +447,18 @@
case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
pr_err("Received a ACK/NACK PDU\n");
- rc = -EIO;
- goto error;
+
+ if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
+ PROTOCOL_ERR("14.12.3.3");
+ rc = -EIO;
+ goto exit;
+ }
+
+ ddev->curr_nfc_dep_pni =
+ DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
+
+ rc = -EINVAL;
+ goto exit;
case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
if (!DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) {
@@ -592,9 +602,22 @@
switch (DIGITAL_NFC_DEP_PFB_TYPE(pfb)) {
case DIGITAL_NFC_DEP_PFB_I_PDU:
pr_debug("DIGITAL_NFC_DEP_PFB_I_PDU\n");
- ddev->curr_nfc_dep_pni = DIGITAL_NFC_DEP_PFB_PNI(pfb);
+
+ if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
+ PROTOCOL_ERR("14.12.3.4");
+ rc = -EIO;
+ goto exit;
+ }
+
+ rc = 0;
break;
case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
+ if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
+ PROTOCOL_ERR("14.12.3.4");
+ rc = -EIO;
+ goto exit;
+ }
+
pr_err("Received a ACK/NACK PDU\n");
rc = -EINVAL;
goto exit;
@@ -629,6 +652,9 @@
sizeof(ddev->did));
}
+ ddev->curr_nfc_dep_pni =
+ DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
+
digital_skb_push_dep_sod(ddev, skb);
ddev->skb_add_crc(skb);
@@ -677,6 +703,8 @@
ddev->skb_add_crc(skb);
+ ddev->curr_nfc_dep_pni = 0;
+
rc = digital_tg_send_cmd(ddev, skb, 0, digital_tg_send_psl_res_complete,
(void *)(unsigned long)rf_tech);
if (rc)
@@ -800,6 +828,8 @@
ddev->skb_add_crc(skb);
+ ddev->curr_nfc_dep_pni = 0;
+
rc = digital_tg_send_cmd(ddev, skb, 999,
digital_tg_send_atr_res_complete, NULL);
if (rc)