From fd337dd0ccadd1bed36475409172009c610388d1 Mon Sep 17 00:00:00 2001
From: Romain Tartiere <romain.tartiere@gmail.com>
Date: Fri, 20 Aug 2010 10:40:00 +0000
Subject: [PATCH] Also detect error frames in pn532_uart (tested) and arygon
 drivers (not tested).

---
 libnfc/drivers/arygon.c     | 14 +++++++++-----
 libnfc/drivers/pn532_uart.c | 20 ++++++++++++--------
 2 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/libnfc/drivers/arygon.c b/libnfc/drivers/arygon.c
index 770f049..4d5c8bf 100644
--- a/libnfc/drivers/arygon.c
+++ b/libnfc/drivers/arygon.c
@@ -237,11 +237,6 @@ bool arygon_transceive(nfc_device_t* pnd, const byte_t* pbtTx, const size_t szTx
   PRINT_HEX("RX", abtRxBuf,szRxBufLen);
 #endif
 
-  // When the answer should be ignored, just return a successful result
-  if(pbtRx == NULL || pszRxLen == NULL) return true;
-
-  // Only succeed when the result is at least 00 00 FF xx Fx Dx xx .. .. .. xx 00 (x = variable)
-  if(szRxBufLen < 9) return false;
 
 #ifdef DEBUG
   PRINT_HEX("TX", ack_frame, 6);
@@ -251,6 +246,15 @@ bool arygon_transceive(nfc_device_t* pnd, const byte_t* pbtTx, const size_t szTx
     return false;
   }
 
+  if (!pn53x_transceive_check_error_frame_callback(pnd, abtRxBuf, szRxBufLen))
+    return false;
+
+  // When the answer should be ignored, just return a successful result
+  if(pbtRx == NULL || pszRxLen == NULL) return true;
+
+  // Only succeed when the result is at least 00 00 FF xx Fx Dx xx .. .. .. xx 00 (x = variable)
+  if(szRxBufLen < 9) return false;
+
   // Remove the preceding and appending bytes 00 00 ff 00 ff 00 00 00 FF xx Fx .. .. .. xx 00 (x = variable)
   *pszRxLen = szRxBufLen - 9;
   memcpy(pbtRx, abtRxBuf+7, *pszRxLen);
diff --git a/libnfc/drivers/pn532_uart.c b/libnfc/drivers/pn532_uart.c
index 88d01f5..982cd82 100644
--- a/libnfc/drivers/pn532_uart.c
+++ b/libnfc/drivers/pn532_uart.c
@@ -237,14 +237,6 @@ bool pn532_uart_transceive(nfc_device_t* pnd, const byte_t* pbtTx, const size_t
 #endif
   }
 
-  // When the answer should be ignored, just return a successful result
-  if(pbtRx == NULL || pszRxLen == NULL) return true;
-
-  // Only succeed when the result is at least 00 00 FF xx Fx Dx xx .. .. .. xx 00 (x = variable)
-  if(szRxBufLen < 9) {
-    pnd->iLastError = DEINVAL;
-    return false;
-  }
 
 #ifdef DEBUG
   PRINT_HEX("TX", ack_frame,6);
@@ -256,6 +248,18 @@ bool pn532_uart_transceive(nfc_device_t* pnd, const byte_t* pbtTx, const size_t
     return false;
   }
 
+  if (!pn53x_transceive_check_error_frame_callback (pnd, abtRxBuf, szRxBufLen))
+    return false;
+
+  // When the answer should be ignored, just return a successful result
+  if(pbtRx == NULL || pszRxLen == NULL) return true;
+
+  // Only succeed when the result is at least 00 00 FF xx Fx Dx xx .. .. .. xx 00 (x = variable)
+  if(szRxBufLen < 9) {
+    pnd->iLastError = DEINVAL;
+    return false;
+  }
+
   // Remove the preceding and appending bytes 00 00 ff 00 ff 00 00 00 FF xx Fx .. .. .. xx 00 (x = variable)
   *pszRxLen = szRxBufLen - 9;
   memcpy(pbtRx, abtRxBuf+7, *pszRxLen);