Refactor HAL macro using gcc statement expressions to avoid returning from a macro. (#705)

Fix memory leak in nfc_initiator_select_passive_target().

libnfc/nfc-internal.h

@@ -46,13 +46,15 @@
  * @macro HAL
  * @brief Execute corresponding driver function if exists.
  */
-#define HAL( FUNCTION, ... ) pnd->last_error = 0; \
+#define HAL( FUNCTION, ... ) __extension__ ({int res; \
+  pnd->last_error = 0; \
   if (pnd->driver->FUNCTION) { \
-    return pnd->driver->FUNCTION( __VA_ARGS__ ); \
+    res = pnd->driver->FUNCTION( __VA_ARGS__ ); \
   } else { \
     pnd->last_error = NFC_EDEVNOTSUPP; \
-    return false; \
+    res = false; \
-  }
+  } \
+  res;})
 
 #ifndef MIN
 #define MIN(a,b) (((a) < (b)) ? (a) : (b))

libnfc/nfc.c

@@ -446,7 +446,7 @@ int
 nfc_device_set_property_int(nfc_device *pnd, const nfc_property property, const int value)
 {
   log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_DEBUG, "set_property_int %s %s", nfc_property_name[property], value ? "True" : "False");
-  HAL(device_set_property_int, pnd, property, value);
+  return HAL(device_set_property_int, pnd, property, value);
 }
 
 
@@ -466,7 +466,7 @@ int
 nfc_device_set_property_bool(nfc_device *pnd, const nfc_property property, const bool bEnable)
 {
   log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_DEBUG, "set_property_bool %s %s", nfc_property_name[property], bEnable ? "True" : "False");
-  HAL(device_set_property_bool, pnd, property, bEnable);
+  return HAL(device_set_property_bool, pnd, property, bEnable);
 }
 
 /** @ingroup initiator
@@ -517,7 +517,7 @@ nfc_initiator_init(nfc_device *pnd)
   // Disallow multiple frames
   if ((res = nfc_device_set_property_bool(pnd, NP_ACCEPT_MULTIPLE_FRAMES, false)) < 0)
     return res;
-  HAL(initiator_init, pnd);
+  return HAL(initiator_init, pnd);
 }
 
 /** @ingroup initiator
@@ -532,7 +532,7 @@ nfc_initiator_init(nfc_device *pnd)
 int
 nfc_initiator_init_secure_element(nfc_device *pnd)
 {
-  HAL(initiator_init_secure_element, pnd);
+  return HAL(initiator_init_secure_element, pnd);
 }
 
 /** @ingroup initiator
@@ -566,29 +566,27 @@ nfc_initiator_select_passive_target(nfc_device *pnd,
 {
   uint8_t *abtInit = NULL;
   uint8_t maxAbt = MAX(12, szInitData);
-  uint8_t *abtTmpInit = malloc(sizeof(uint8_t) * maxAbt);
   size_t  szInit = 0;
   int res;
   if ((res = nfc_device_validate_modulation(pnd, N_INITIATOR, &nm)) != NFC_SUCCESS) {
-    free(abtTmpInit);
     return res;
   }
   if (szInitData == 0) {
     // Provide default values, if any
     prepare_initiator_data(nm, &abtInit, &szInit);
-    free(abtTmpInit);
+    return HAL(initiator_select_passive_target, pnd, nm, abtInit, szInit, pnt);
-  } else if (nm.nmt == NMT_ISO14443A) {
+  }
-    abtInit = abtTmpInit;
+
+  abtInit = malloc(sizeof(uint8_t) * maxAbt);
+  if (nm.nmt == NMT_ISO14443A) {
     iso14443_cascade_uid(pbtInitData, szInitData, abtInit, &szInit);
   } else {
-    abtInit = abtTmpInit;
     memcpy(abtInit, pbtInitData, szInitData);
-    free(abtTmpInit);
     szInit = szInitData;
   }
-  HAL(initiator_select_passive_target, pnd, nm, abtInit, szInit, pnt);
+  res = HAL(initiator_select_passive_target, pnd, nm, abtInit, szInit, pnt);
-
+  free(abtInit);
-  free(abtTmpInit);
+  return res;
 }
 
 /** @ingroup initiator
@@ -680,7 +678,7 @@ nfc_initiator_poll_target(nfc_device *pnd,
                           const uint8_t uiPollNr, const uint8_t uiPeriod,
                           nfc_target *pnt)
 {
-  HAL(initiator_poll_target, pnd, pnmModulations, szModulations, uiPollNr, uiPeriod, pnt);
+  return HAL(initiator_poll_target, pnd, pnmModulations, szModulations, uiPollNr, uiPeriod, pnt);
 }
 
 
@@ -709,7 +707,7 @@ nfc_initiator_select_dep_target(nfc_device *pnd,
                                 const nfc_dep_mode ndm, const nfc_baud_rate nbr,
                                 const nfc_dep_info *pndiInitiator, nfc_target *pnt, const int timeout)
 {
-  HAL(initiator_select_dep_target, pnd, ndm, nbr, pndiInitiator, pnt, timeout);
+  return HAL(initiator_select_dep_target, pnd, ndm, nbr, pndiInitiator, pnt, timeout);
 }
 
 /** @ingroup initiator
@@ -780,7 +778,7 @@ end:
 int
 nfc_initiator_deselect_target(nfc_device *pnd)
 {
-  HAL(initiator_deselect_target, pnd);
+  return HAL(initiator_deselect_target, pnd);
 }
 
 /** @ingroup initiator
@@ -815,7 +813,7 @@ int
 nfc_initiator_transceive_bytes(nfc_device *pnd, const uint8_t *pbtTx, const size_t szTx, uint8_t *pbtRx,
                                const size_t szRx, int timeout)
 {
-  HAL(initiator_transceive_bytes, pnd, pbtTx, szTx, pbtRx, szRx, timeout)
+  return HAL(initiator_transceive_bytes, pnd, pbtTx, szTx, pbtRx, szRx, timeout);
 }
 
 /** @ingroup initiator
@@ -861,7 +859,7 @@ nfc_initiator_transceive_bits(nfc_device *pnd,
                               uint8_t *pbtRxPar)
 {
   (void)szRx;
-  HAL(initiator_transceive_bits, pnd, pbtTx, szTxBits, pbtTxPar, pbtRx, pbtRxPar);
+  return HAL(initiator_transceive_bits, pnd, pbtTx, szTxBits, pbtTxPar, pbtRx, pbtRxPar);
 }
 
 /** @ingroup initiator
@@ -896,7 +894,7 @@ nfc_initiator_transceive_bytes_timed(nfc_device *pnd,
                                      uint8_t *pbtRx, const size_t szRx,
                                      uint32_t *cycles)
 {
-  HAL(initiator_transceive_bytes_timed, pnd, pbtTx, szTx, pbtRx, szRx, cycles);
+  return HAL(initiator_transceive_bytes_timed, pnd, pbtTx, szTx, pbtRx, szRx, cycles);
 }
 
 /** @ingroup initiator
@@ -912,7 +910,7 @@ nfc_initiator_transceive_bytes_timed(nfc_device *pnd,
 int
 nfc_initiator_target_is_present(nfc_device *pnd, const nfc_target *pnt)
 {
-  HAL(initiator_target_is_present, pnd, pnt);
+  return HAL(initiator_target_is_present, pnd, pnt);
 }
 
 /** @ingroup initiator
@@ -944,7 +942,7 @@ nfc_initiator_transceive_bits_timed(nfc_device *pnd,
                                     uint32_t *cycles)
 {
   (void)szRx;
-  HAL(initiator_transceive_bits_timed, pnd, pbtTx, szTxBits, pbtTxPar, pbtRx, pbtRxPar, cycles);
+  return HAL(initiator_transceive_bits_timed, pnd, pbtTx, szTxBits, pbtTxPar, pbtRx, pbtRxPar, cycles);
 }
 
 /** @ingroup target
@@ -1008,7 +1006,7 @@ nfc_target_init(nfc_device *pnd, nfc_target *pnt, uint8_t *pbtRx, const size_t s
   if ((res = nfc_device_set_property_bool(pnd, NP_ACTIVATE_FIELD, false)) < 0)
     return res;
 
-  HAL(target_init, pnd, pnt, pbtRx, szRx, timeout);
+  return HAL(target_init, pnd, pnt, pbtRx, szRx, timeout);
 }
 
 /** @ingroup dev
@@ -1024,7 +1022,7 @@ nfc_target_init(nfc_device *pnd, nfc_target *pnt, uint8_t *pbtRx, const size_t s
 int
 nfc_idle(nfc_device *pnd)
 {
-  HAL(idle, pnd);
+  return HAL(idle, pnd);
 }
 
 /** @ingroup dev
@@ -1041,7 +1039,7 @@ nfc_idle(nfc_device *pnd)
 int
 nfc_abort_command(nfc_device *pnd)
 {
-  HAL(abort_command, pnd);
+  return HAL(abort_command, pnd);
 }
 
 /** @ingroup target
@@ -1062,7 +1060,7 @@ nfc_abort_command(nfc_device *pnd)
 int
 nfc_target_send_bytes(nfc_device *pnd, const uint8_t *pbtTx, const size_t szTx, int timeout)
 {
-  HAL(target_send_bytes, pnd, pbtTx, szTx, timeout);
+  return HAL(target_send_bytes, pnd, pbtTx, szTx, timeout);
 }
 
 /** @ingroup target
@@ -1082,7 +1080,7 @@ nfc_target_send_bytes(nfc_device *pnd, const uint8_t *pbtTx, const size_t szTx,
 int
 nfc_target_receive_bytes(nfc_device *pnd, uint8_t *pbtRx, const size_t szRx, int timeout)
 {
-  HAL(target_receive_bytes, pnd, pbtRx, szRx, timeout);
+  return HAL(target_receive_bytes, pnd, pbtRx, szRx, timeout);
 }
 
 /** @ingroup target
@@ -1099,7 +1097,7 @@ nfc_target_receive_bytes(nfc_device *pnd, uint8_t *pbtRx, const size_t szRx, int
 int
 nfc_target_send_bits(nfc_device *pnd, const uint8_t *pbtTx, const size_t szTxBits, const uint8_t *pbtTxPar)
 {
-  HAL(target_send_bits, pnd, pbtTx, szTxBits, pbtTxPar);
+  return HAL(target_send_bits, pnd, pbtTx, szTxBits, pbtTxPar);
 }
 
 /** @ingroup target
@@ -1121,7 +1119,7 @@ nfc_target_send_bits(nfc_device *pnd, const uint8_t *pbtTx, const size_t szTxBit
 int
 nfc_target_receive_bits(nfc_device *pnd, uint8_t *pbtRx, const size_t szRx, uint8_t *pbtRxPar)
 {
-  HAL(target_receive_bits, pnd, pbtRx, szRx, pbtRxPar);
+  return HAL(target_receive_bits, pnd, pbtRx, szRx, pbtRxPar);
 }
 
 static struct sErrorMessage {
@@ -1240,7 +1238,7 @@ nfc_device_get_connstring(nfc_device *pnd)
 int
 nfc_device_get_supported_modulation(nfc_device *pnd, const nfc_mode mode, const nfc_modulation_type **const supported_mt)
 {
-  HAL(get_supported_modulation, pnd, mode, supported_mt);
+  return HAL(get_supported_modulation, pnd, mode, supported_mt);
 }
 
 /** @ingroup data
@@ -1254,7 +1252,7 @@ nfc_device_get_supported_modulation(nfc_device *pnd, const nfc_mode mode, const
 int
 nfc_device_get_supported_baud_rate(nfc_device *pnd, const nfc_modulation_type nmt, const nfc_baud_rate **const supported_br)
 {
-  HAL(get_supported_baud_rate, pnd, N_INITIATOR, nmt, supported_br);
+  return HAL(get_supported_baud_rate, pnd, N_INITIATOR, nmt, supported_br);
 }
 
 /** @ingroup data
@@ -1268,7 +1266,7 @@ nfc_device_get_supported_baud_rate(nfc_device *pnd, const nfc_modulation_type nm
 int
 nfc_device_get_supported_baud_rate_target_mode(nfc_device *pnd, const nfc_modulation_type nmt, const nfc_baud_rate **const supported_br)
 {
-  HAL(get_supported_baud_rate, pnd, N_TARGET, nmt, supported_br);
+  return HAL(get_supported_baud_rate, pnd, N_TARGET, nmt, supported_br);
 }
 
 /** @ingroup data
@@ -1353,7 +1351,7 @@ nfc_free(void *p)
 int
 nfc_device_get_information_about(nfc_device *pnd, char **buf)
 {
-  HAL(device_get_information_about, pnd, buf);
+  return HAL(device_get_information_about, pnd, buf);
 }
 
 /** @ingroup string-converter