ACR122 devices support enhancements.

- Add driver agnostic nfc_pick_device(), nfc_list_devices();
  - New API function: nfc_list_devices();
  - PCSC Context sharing for acr122 driver;
  - List all devices in nfc-list(1);
  - Various code fixes and cleanup;
  - Remove warnings when compiling;
  - Merge r191:199 from trunk \_°< Coin!

src/examples/nfc-list.c

@@ -32,18 +32,26 @@
 #include "nfc-messages.h"
 #include "bitutils.h"
 
+#define MAX_DEVICE_COUNT 16
+
 static nfc_device_t* pnd;
 static byte_t abtFelica[5] = { 0x00, 0xff, 0xff, 0x00, 0x00 };
 
 int main(int argc, const char* argv[])
 {
+  size_t szFound;
+  int i;
   nfc_target_info_t nti;
+  nfc_device_desc_t *pnddDevices;
 
+  // Display libnfc version
   const char* acLibnfcVersion = nfc_version();
   printf("%s use libnfc %s\n", argv[0], acLibnfcVersion);
 
-  // Try to open the NFC device
+  // Lazy way to open an NFC device
+  /*
   pnd = nfc_connect(NULL);
+  */
 
   // If specific device is wanted, i.e. an ARYGON device on /dev/ttyUSB0
   /*
@@ -54,10 +62,27 @@ int main(int argc, const char* argv[])
 
   pnd = nfc_connect(&ndd);
   */
+  if (!(pnddDevices = malloc (MAX_DEVICE_COUNT * sizeof (*pnddDevices))))
+  {
+    fprintf (stderr, "malloc() failed\n");
+    return EXIT_FAILURE;
+  }
+
+  nfc_list_devices (pnddDevices, MAX_DEVICE_COUNT, &szFound);
+
+  if (szFound == 0)
+  {
+    INFO("%s", "No device found.");
+  }
+
+  for (i = 0; i < szFound; i++)
+  {
+    pnd = nfc_connect(&(pnddDevices[i]));
+
 
   if (pnd == NULL)
   {
-    ERR("Unable to connect to NFC device.");
+    ERR("%s", "Unable to connect to NFC device.");
     return 1;
   }
   nfc_initiator_init(pnd);
@@ -121,5 +146,8 @@ int main(int argc, const char* argv[])
   }
 
   nfc_disconnect(pnd);
+  }
+
+  free (pnddDevices);
   return 0;
 }

src/examples/nfc-relay.c

@@ -25,6 +25,7 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
+#include <signal.h>
 
 #include <nfc.h>
 
@@ -41,6 +42,14 @@ static byte_t abtTagRxPar[MAX_FRAME_LEN];
 static size_t szTagRxBits;
 static nfc_device_t* pndReader;
 static nfc_device_t* pndTag;
+static bool quitting=false;
+
+void intr_hdlr(void)
+{
+  printf("\nQuitting...\n");
+  quitting=true;
+  return;
+}
 
 void print_usage(char* argv[])
 {
@@ -70,6 +79,12 @@ int main(int argc,char* argv[])
     }
   }
 
+#ifdef WIN32
+  signal(SIGINT, (void (__cdecl*)(int)) intr_hdlr);
+#else
+  signal(SIGINT, (void (*)()) intr_hdlr);
+#endif
+
   // Try to open the NFC emulator device
   pndTag = nfc_connect(NULL);
   if (pndTag == NULL)
@@ -83,7 +98,12 @@ int main(int argc,char* argv[])
   printf("[+] Try to break out the auto-emulation, this requires a second reader!\n");
   printf("[+] To do this, please send any command after the anti-collision\n");
   printf("[+] For example, send a RATS command or use the \"nfc-anticol\" tool\n");
-  nfc_target_init(pndTag,abtReaderRx,&szReaderRxBits);
+  if (!nfc_target_init(pndTag,abtReaderRx,&szReaderRxBits))
+  {
+    printf("[+] Initialization of NFC emulator failed\n");
+    nfc_disconnect(pndTag);
+    return 1;
+  }
   printf("[+] Configuring emulator settings\n");
   nfc_configure(pndTag,NDO_HANDLE_CRC,false);
   nfc_configure(pndTag,NDO_HANDLE_PARITY,false);
@@ -94,12 +114,13 @@ int main(int argc,char* argv[])
   pndReader = NULL;
   while (pndReader == NULL) pndReader = nfc_connect(NULL);
   printf("[+] Configuring NFC reader settings\n");
+  nfc_initiator_init(pndReader);
   nfc_configure(pndReader,NDO_HANDLE_CRC,false);
   nfc_configure(pndReader,NDO_HANDLE_PARITY,false);
   nfc_configure(pndReader,NDO_ACCEPT_INVALID_FRAMES,true);
   printf("[+] Done, relaying frames now!\n\n");
 
-  while(true)
+  while(!quitting)
   {
     // Test if we received a frame from the reader
     if (nfc_target_receive_bits(pndTag,abtReaderRx,&szReaderRxBits,abtReaderRxPar))