- Detect errors in pn53x_get_reg();

- Add a test case to confirm an endianness problem on little-endian machines.

libnfc/chips/pn53x.c

@@ -156,27 +156,29 @@ bool pn53x_transceive(nfc_device_t* pnd, const byte_t* pbtTx, const size_t szTxL
   return (0 == pnd->iLastError);
 }
 
-byte_t pn53x_get_reg(nfc_device_t* pnd, uint16_t ui16Reg)
+bool pn53x_get_reg(nfc_device_t* pnd, uint16_t ui16Reg, uint8_t* ui8Value)
 {
-  uint8_t ui8Value;
   size_t szValueLen = 1;
   byte_t abtCmd[sizeof(pncmd_get_register)];
   memcpy(abtCmd,pncmd_get_register,sizeof(pncmd_get_register));
 
   abtCmd[2] = ui16Reg >> 8;
   abtCmd[3] = ui16Reg & 0xff;
-  pn53x_transceive(pnd,abtCmd,4,&ui8Value,&szValueLen);
-  return ui8Value;
+  return pn53x_transceive(pnd,abtCmd,4,ui8Value,&szValueLen);
 }
 
 bool pn53x_set_reg(nfc_device_t* pnd, uint16_t ui16Reg, uint8_t ui8SybmolMask, uint8_t ui8Value)
 {
+  uint8_t ui8Current;
   byte_t abtCmd[sizeof(pncmd_set_register)];
   memcpy(abtCmd,pncmd_set_register,sizeof(pncmd_set_register));
 
   abtCmd[2] = ui16Reg >> 8;
   abtCmd[3] = ui16Reg & 0xff;
-  abtCmd[4] = ui8Value | (pn53x_get_reg(pnd,ui16Reg) & (~ui8SybmolMask));
+  if (!pn53x_get_reg(pnd,ui16Reg, &ui8Current))
+      return false;
+
+  abtCmd[4] = ui8Value | (ui8Current & (~ui8SybmolMask));
   return pn53x_transceive(pnd,abtCmd,5,NULL,NULL);
 }
 
@@ -784,6 +786,7 @@ bool pn53x_initiator_transceive_bits(nfc_device_t* pnd, const byte_t* pbtTx, con
   size_t szRxLen;
   size_t szFrameBits = 0;
   size_t szFrameBytes = 0;
+  uint8_t ui8rcc;
   uint8_t ui8Bits = 0;
   byte_t abtCmd[sizeof(pncmd_initiator_exchange_raw_data)];
 
@@ -815,7 +818,9 @@ bool pn53x_initiator_transceive_bits(nfc_device_t* pnd, const byte_t* pbtTx, con
   if (!pn53x_transceive(pnd,abtCmd,szFrameBytes+2,abtRx,&szRxLen)) return false;
 
   // Get the last bit-count that is stored in the received byte 
-  ui8Bits = pn53x_get_reg(pnd,REG_CIU_CONTROL) & SYMBOL_RX_LAST_BITS;
+  if (!pn53x_get_reg(pnd,REG_CIU_CONTROL, &ui8rcc))
+      return false;
+  ui8Bits = ui8rcc & SYMBOL_RX_LAST_BITS;
 
   // Recover the real frame length in bits
   szFrameBits = ((szRxLen-1-((ui8Bits==0)?0:1))*8)+ui8Bits;
@@ -909,6 +914,7 @@ bool pn53x_target_init(nfc_device_t* pnd, byte_t* pbtRx, size_t* pszRxBits)
 {
   byte_t abtRx[MAX_FRAME_LEN];
   size_t szRxLen;
+  uint8_t ui8rcc;
   uint8_t ui8Bits;
   // Save the current configuration settings
   bool bCrc = pnd->bCrc;
@@ -944,7 +950,8 @@ bool pn53x_target_init(nfc_device_t* pnd, byte_t* pbtRx, size_t* pszRxBits)
   if (!pn53x_transceive(pnd,abtCmd,39,abtRx,&szRxLen)) return false;
 
   // Get the last bit-count that is stored in the received byte 
-  ui8Bits = pn53x_get_reg(pnd,REG_CIU_CONTROL) & SYMBOL_RX_LAST_BITS;
+  if (!pn53x_get_reg(pnd,REG_CIU_CONTROL, &ui8rcc)) return false;
+  ui8Bits = ui8rcc & SYMBOL_RX_LAST_BITS;
 
   // We are sure the parity is handled by the PN53X chip, so we handle it this way
   *pszRxBits = ((szRxLen-1-((ui8Bits==0)?0:1))*8)+ui8Bits;
@@ -963,13 +970,15 @@ bool pn53x_target_receive_bits(nfc_device_t* pnd, byte_t* pbtRx, size_t* pszRxBi
   byte_t abtRx[MAX_FRAME_LEN];
   size_t szRxLen;
   size_t szFrameBits;
+  uint8_t ui8rcc;
   uint8_t ui8Bits;
 
   // Try to gather a received frame from the reader
   if (!pn53x_transceive(pnd,pncmd_target_receive,2,abtRx,&szRxLen)) return false;
 
   // Get the last bit-count that is stored in the received byte 
-  ui8Bits = pn53x_get_reg(pnd,REG_CIU_CONTROL) & SYMBOL_RX_LAST_BITS;
+  if (!pn53x_get_reg(pnd,REG_CIU_CONTROL, &ui8rcc)) return false;
+  ui8Bits = ui8rcc & SYMBOL_RX_LAST_BITS;
 
   // Recover the real frame length in bits
   szFrameBits = ((szRxLen-1-((ui8Bits==0)?0:1))*8)+ui8Bits;

libnfc/chips/pn53x.h

@@ -81,7 +81,7 @@
 bool pn53x_transceive_check_ack_frame_callback(nfc_device_t* pnd, const byte_t *pbtRxFrame, const size_t szRxFrameLen);
 bool pn53x_transceive_check_error_frame_callback(nfc_device_t* pnd, const byte_t *pbtRxFrame, const size_t szRxFrameLen);
 bool pn53x_transceive(nfc_device_t* pnd, const byte_t* pbtTx, const size_t szTxLen, byte_t* pbtRx, size_t* pszRxLen);
-byte_t pn53x_get_reg(nfc_device_t* pnd, uint16_t ui16Reg);
+bool pn53x_get_reg(nfc_device_t* pnd, uint16_t ui16Reg, uint8_t* ui8Value);
 bool pn53x_set_reg(nfc_device_t* pnd, uint16_t ui16Reg, uint8_t ui8SybmolMask, uint8_t ui8Value);
 bool pn53x_set_parameters(nfc_device_t* pnd, uint8_t ui8Value);
 bool pn53x_set_tx_bits(nfc_device_t* pnd, uint8_t ui8Bits);

test/Makefile.am

@@ -8,13 +8,17 @@ TESTS = run-test.sh
 TESTS_ENVIRONMENT = NO_MAKE=yes CUTTER="$(CUTTER)"
 
 noinst_LTLIBRARIES = \
-		     test_access_storm.la
+		     test_access_storm.la \
+		     test_register_endianness.la
 
 AM_LDFLAGS = -module -rpath $(libdir) -avoid-version -no-undefined
 
 test_access_storm_la_SOURCES = test_access_storm.c
 test_access_storm_la_LIBADD = $(top_builddir)/libnfc/libnfc.la
 
+test_register_endianness_la_SOURCES = test_register_endianness.c
+test_register_endianness_la_LIBADD = $(top_builddir)/libnfc/libnfc.la
+
 echo-cutter:
 		@echo $(CUTTER)
 

test/test_register_endianness.c

@@ -0,0 +1,39 @@
+#include <cutter.h>
+
+#include <nfc/nfc.h>
+
+#define MAX_DEVICE_COUNT 1
+#define MAX_TARGET_COUNT 1
+
+bool pn53x_get_reg(nfc_device_t* pnd, uint16_t ui16Reg, uint8_t* ui8Value);
+
+void
+test_register_endianness (void)
+{
+    nfc_device_desc_t devices[MAX_DEVICE_COUNT];
+    size_t device_count;
+    bool res;
+
+    nfc_list_devices (devices, MAX_DEVICE_COUNT, &device_count);
+    if (!device_count)
+	cut_omit ("No NFC device found");
+
+    nfc_device_t *device;
+
+    device = nfc_connect (&(devices[0]));
+    cut_assert_not_null (device, cut_message ("nfc_connect"));
+
+    uint8_t value;
+
+    /* Read valid XRAM memory */
+    res = pn53x_get_reg (device, 0xF0FF, &value);
+    cut_assert_true (res, cut_message ("read register 0xF0FF"));
+    nfc_perror (device, "get");
+
+    /* Read invalid SFR register */
+    res = pn53x_get_reg (device, 0xFFF0, &value);
+    cut_assert_false (res, cut_message ("read register 0xFFF0"));
+    nfc_perror (device, "get");
+
+    nfc_disconnect (device);
+}