libnfc/examples/nfc-anticol.c

/*-
 * Public platform independent Near Field Communication (NFC) library
 * 
 * Copyright (C) 2009, Roel Verdult
 * 
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 */

/** 
 * @file nfc-anticol.c
 * @brief
 */

#ifdef HAVE_CONFIG_H
  #include "config.h"
#endif // HAVE_CONFIG_H

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>

#include <nfc/nfc.h>

#include <nfc/nfc-messages.h>
#include "nfc-utils.h"

#define SAK_FLAG_ATS_SUPPORTED 0x20

#define MAX_FRAME_LEN 264

static byte_t abtRx[MAX_FRAME_LEN];
static size_t szRxBits;
static size_t szRxLen;
static byte_t abtUid[10];
static size_t szUidLen = 4;
static nfc_device_t* pnd;

bool quiet_output = false;

// ISO14443A Anti-Collision Commands
byte_t abtReqa      [1] = { 0x26 };
byte_t abtSelectAll [2] = { 0x93,0x20 };
byte_t abtSelectTag [9] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
byte_t abtRats      [4] = { 0xe0,0x50,0xbc,0xa5 };
byte_t abtHalt      [4] = { 0x50,0x00,0x57,0xcd };

static bool transmit_bits(const byte_t* pbtTx, const size_t szTxBits)
{
  // Show transmitted command
  if(!quiet_output)
  {
    printf("R: "); 
    print_hex_bits(pbtTx,szTxBits);
  }

  // Transmit the bit frame command, we don't use the arbitrary parity feature
  if (!nfc_initiator_transceive_bits(pnd,pbtTx,szTxBits,NULL,abtRx,&szRxBits,NULL)) return false;

  // Show received answer
  if(!quiet_output)
  {
    printf("T: "); 
    print_hex_bits(abtRx,szRxBits);
  }

  // Succesful transfer
  return true;
}


static bool transmit_bytes(const byte_t* pbtTx, const size_t szTxLen)
{
  // Show transmitted command
  if(!quiet_output)
  {
    printf("R: "); 
    print_hex(pbtTx,szTxLen);
  }

  // Transmit the command bytes
  if (!nfc_initiator_transceive_bytes(pnd,pbtTx,szTxLen,abtRx,&szRxLen)) return false;

  // Show received answer
  if(!quiet_output)
  {
    printf("T: "); 
    print_hex(abtRx,szRxLen);
  }

  // Succesful transfer
  return true;
}

static void print_usage(char* argv[])
{
  printf("Usage: %s [OPTIONS]\n", argv[0]);
  printf("Options:\n");
  printf("\t-h\tHelp. Print this message.\n");
  printf("\t-q\tQuiet mode. Suppress output of READER and EMULATOR data (improves timing).\n");
}

int main(int argc,char* argv[])
{
  int arg;

  // Get commandline options
  for (arg=1;arg<argc;arg++) {
    if (0 == strcmp(argv[arg], "-h")) {
      print_usage(argv);
      return 0;
    } else if (0 == strcmp(argv[arg], "-q")) {
      INFO("%s", "Quiet mode.");
      quiet_output = true;
    } else {
      ERR("%s is not supported option.", argv[arg]);
      print_usage(argv);
      return -1;
    }
  }

  // Try to open the NFC reader
  pnd = nfc_connect(NULL);

  if (!pnd)
  {
    printf("Error connecting NFC reader\n");
    return 1;
  }
  nfc_initiator_init(pnd);

  // Drop the field for a while
  nfc_configure(pnd,NDO_ACTIVATE_FIELD,false);

  // Configure the CRC and Parity settings
  nfc_configure(pnd,NDO_HANDLE_CRC,false);
  nfc_configure(pnd,NDO_HANDLE_PARITY,true);

  // Enable field so more power consuming cards can power themselves up
  nfc_configure(pnd,NDO_ACTIVATE_FIELD,true);

  printf("\nConnected to NFC reader: %s\n\n",pnd->acName);

  // Send the 7 bits request command specified in ISO 14443A (0x26)
  if (!transmit_bits(abtReqa,7))
  {
    printf("Error: No tag available\n");
    nfc_disconnect(pnd);
    return 1;
  }

  // Anti-collision
  transmit_bytes(abtSelectAll,2);

  // Save the UID
  memcpy(abtUid,abtRx,4);
  memcpy(abtSelectTag+2,abtRx,5);
  append_iso14443a_crc(abtSelectTag,7);
  transmit_bytes(abtSelectTag,9);

  // Test if we are dealing with a 4 bytes uid
  if (abtUid[0]!= 0x88)
  {
    szUidLen = 4;
  } else {
    // We have to do the anti-collision for cascade level 2
    abtSelectAll[0] = 0x95;
    abtSelectTag[0] = 0x95;

    // Anti-collision
    transmit_bytes(abtSelectAll,2);

    // Save the UID
    memcpy(abtUid+4,abtRx,4);
    memcpy(abtSelectTag+2,abtRx,5);
    append_iso14443a_crc(abtSelectTag,7);
    transmit_bytes(abtSelectTag,9);
    szUidLen = 7;
  }

  // Request ATS, this only applies to tags that support ISO 14443A-4
  if (abtRx[0] & SAK_FLAG_ATS_SUPPORTED) transmit_bytes(abtRats,4);

  // Done, halt the tag now
  transmit_bytes(abtHalt,4);

  printf("\nFound tag with UID: ");
  if (szUidLen == 7) {
    printf("%02x%02x%02x", abtUid[6], abtUid[5], abtUid[4]);
  }
  printf("%02x%02x%02x%02x\n", abtUid[3], abtUid[2], abtUid[1], abtUid[0]);

  nfc_disconnect(pnd);
  return 0;
}