src/rfid_layer2_iso14443a.c

   1 /* ISO 14443-3 A anticollision implementation
   2  *
   3  * (C) 2005 by Harald Welte <laforge@gnumonks.org>
   4  *
   5  */
   6
   7 /*
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License version 2
  10  *  as published by the Free Software Foundation
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24 #include <string.h>
  25 #include <errno.h>
  26
  27 #include <librfid/rfid.h>
  28 #include <librfid/rfid_layer2.h>
  29 #include <librfid/rfid_reader.h>
  30 #include <librfid/rfid_layer2_iso14443a.h>
  31
  32 #define TIMEOUT 1236
  33
  34 /* Transcieve a 7-bit short frame */
  35 static int
  36 iso14443a_transcieve_sf(struct rfid_layer2_handle *handle,
  37                          unsigned char cmd,
  38                          struct iso14443a_atqa *atqa)
  39 {
  40         struct rfid_reader *rdr = handle->rh->reader;
  41
  42         return rdr->iso14443a.transcieve_sf(handle->rh, cmd, atqa);
  43 }
  44
  45 /* Transmit an anticollission bit frame */
  46 static int
  47 iso14443a_transcieve_acf(struct rfid_layer2_handle *handle,
  48                          struct iso14443a_anticol_cmd *acf,
  49                          unsigned int *bit_of_col)
  50 {
  51         struct rfid_reader *rdr = handle->rh->reader;
  52
  53         return rdr->iso14443a.transcieve_acf(handle->rh, acf, bit_of_col);
  54 }
  55
  56 /* Transmit a regular frame */
  57 static int
  58 iso14443a_transcieve(struct rfid_layer2_handle *handle,
  59                      enum rfid_frametype frametype,
  60                         const unsigned char *tx_buf, unsigned int tx_len,
  61                         unsigned char *rx_buf, unsigned int *rx_len,
  62                         u_int64_t timeout, unsigned int flags)
  63 {
  64         return handle->rh->reader->transcieve(handle->rh, frametype, tx_buf,
  65                                         tx_len, rx_buf, rx_len, timeout, flags);
  66 }
  67
  68 static int
  69 iso14443a_code_nvb_bits(unsigned char *nvb, unsigned int bits)
  70 {
  71         unsigned int byte_count = bits / 8;
  72         unsigned int bit_count = bits % 8;
  73
  74         if (byte_count < 2 || byte_count > 7)
  75                 return -1;
  76
  77         *nvb = ((byte_count & 0xf) << 4) | bit_count;
  78
  79         return 0;
  80 }
  81
  82 /* first bit is '1', second bit '2' */
  83 static void
  84 set_bit_in_field(unsigned char *bitfield, unsigned int bit)
  85 {
  86         unsigned int byte_count = bit / 8;
  87         unsigned int bit_count = bit % 8;
  88
  89         DEBUGP("bitfield=%p, byte_count=%u, bit_count=%u\n",
  90                         bitfield, byte_count, bit_count);
  91         DEBUGP("%p = 0x%02x\n", (bitfield+byte_count), *(bitfield+byte_count));
  92         *(bitfield+byte_count) |= 1 << (bit_count-1);
  93         DEBUGP("%p = 0x%02x\n", (bitfield+byte_count), *(bitfield+byte_count));
  94 }
  95
  96 static int
  97 iso14443a_anticol(struct rfid_layer2_handle *handle)
  98 {
  99         int ret;
 100         unsigned int uid_size;
 101         struct iso14443a_handle *h = &handle->priv.iso14443a;
 102         struct iso14443a_atqa atqa;
 103         struct iso14443a_anticol_cmd acf;
 104         unsigned int bit_of_col;
 105         unsigned char sak[3];
 106         unsigned int rx_len = sizeof(sak);
 107         char *aqptr = (char *) &atqa;
 108
 109         memset(handle->uid, 0, sizeof(handle->uid));
 110         memset(sak, 0, sizeof(sak));
 111         memset(&atqa, 0, sizeof(atqa));
 112         memset(&acf, 0, sizeof(acf));
 113
 114         ret = iso14443a_transcieve_sf(handle, ISO14443A_SF_CMD_REQA, &atqa);
 115         if (ret < 0) {
 116                 h->state = ISO14443A_STATE_REQA_SENT;
 117                 DEBUGP("error during transcieve_sf: %d\n", ret);
 118                 return ret;
 119         }
 120         h->state = ISO14443A_STATE_ATQA_RCVD;
 121
 122         DEBUGP("ATQA: 0x%02x 0x%02x\n", *aqptr, *(aqptr+1));
 123
 124         if (!atqa.bf_anticol) {
 125                 h->state = ISO14443A_STATE_NO_BITFRAME_ANTICOL;
 126                 DEBUGP("no bitframe anticollission bits set, aborting\n");
 127                 return -1;
 128         }
 129
 130         if (atqa.uid_size == 2 || atqa.uid_size == 3)
 131                 uid_size = 3;
 132         else if (atqa.uid_size == 1)
 133                 uid_size = 2;
 134         else
 135                 uid_size = 1;
 136
 137         acf.sel_code = ISO14443A_AC_SEL_CODE_CL1;
 138
 139         h->state = ISO14443A_STATE_ANTICOL_RUNNING;
 140         h->level = ISO14443A_LEVEL_CL1;
 141
 142 cascade:
 143         iso14443a_code_nvb_bits(&acf.nvb, 16);
 144
 145         ret = iso14443a_transcieve_acf(handle, &acf, &bit_of_col);
 146         if (ret < 0)
 147                 return ret;
 148         DEBUGP("bit_of_col = %u\n", bit_of_col);
 149
 150         while (bit_of_col != ISO14443A_BITOFCOL_NONE) {
 151                 set_bit_in_field(&acf.uid_bits[0], bit_of_col-16);
 152                 iso14443a_code_nvb_bits(&acf.nvb, bit_of_col);
 153                 ret = iso14443a_transcieve_acf(handle, &acf, &bit_of_col);
 154                 DEBUGP("bit_of_col = %u\n", bit_of_col);
 155                 if (ret < 0)
 156                         return ret;
 157         }
 158
 159         iso14443a_code_nvb_bits(&acf.nvb, 7*8);
 160         ret = iso14443a_transcieve(handle, RFID_14443A_FRAME_REGULAR,
 161                                    (unsigned char *)&acf, 7,
 162                                    (unsigned char *) &sak, &rx_len,
 163                                    TIMEOUT, 0);
 164         if (ret < 0)
 165                 return ret;
 166
 167         if (sak[0] & 0x04) {
 168                 /* Cascade bit set, UID not complete */
 169                 switch (acf.sel_code) {
 170                 case ISO14443A_AC_SEL_CODE_CL1:
 171                         /* cascading from CL1 to CL2 */
 172                         if (acf.uid_bits[0] != 0x88) {
 173                                 DEBUGP("Cascade bit set, but UID0 != 0x88\n");
 174                                 return -1;
 175                         }
 176                         memcpy(&handle->uid[0], &acf.uid_bits[1], 3);
 177                         acf.sel_code = ISO14443A_AC_SEL_CODE_CL2;
 178                         h->level = ISO14443A_LEVEL_CL2;
 179                         break;
 180                 case ISO14443A_AC_SEL_CODE_CL2:
 181                         /* cascading from CL2 to CL3 */
 182                         memcpy(&handle->uid[3], &acf.uid_bits[1], 3);
 183                         acf.sel_code = ISO14443A_AC_SEL_CODE_CL3;
 184                         h->level = ISO14443A_LEVEL_CL3;
 185                         break;
 186                 default:
 187                         DEBUGP("cannot cascade any further than CL3\n");
 188                         h->state = ISO14443A_STATE_ERROR;
 189                         return -1;
 190                         break;
 191                 }
 192                 goto cascade;
 193
 194         } else {
 195                 switch (acf.sel_code) {
 196                 case ISO14443A_AC_SEL_CODE_CL1:
 197                         /* single size UID (4 bytes) */
 198                         memcpy(&handle->uid[0], &acf.uid_bits[0], 4);
 199                         break;
 200                 case ISO14443A_AC_SEL_CODE_CL2:
 201                         /* double size UID (7 bytes) */
 202                         memcpy(&handle->uid[3], &acf.uid_bits[0], 4);
 203                         break;
 204                 case ISO14443A_AC_SEL_CODE_CL3:
 205                         /* triple size UID (10 bytes) */
 206                         memcpy(&handle->uid[6], &acf.uid_bits[0], 4);
 207                         break;
 208                 }
 209         }
 210
 211         h->level = ISO14443A_LEVEL_NONE;
 212         h->state = ISO14443A_STATE_SELECTED;
 213
 214         {
 215                 if (uid_size == 1)
 216                         handle->uid_len = 4;
 217                 else if (uid_size == 2)
 218                         handle->uid_len = 7;
 219                 else
 220                         handle->uid_len = 10;
 221
 222                 DEBUGP("UID %s\n", rfid_hexdump(handle->uid, handle->uid_len));
 223         }
 224
 225         if (sak[0] & 0x20) {
 226                 DEBUGP("we have a T=CL compliant PICC\n");
 227                 h->tcl_capable = 1;
 228         } else {
 229                 DEBUGP("we have a T!=CL PICC\n");
 230                 h->tcl_capable = 0;
 231         }
 232
 233         return 0;
 234 }
 235
 236 static int
 237 iso14443a_hlta(struct rfid_layer2_handle *handle)
 238 {
 239         int ret;
 240         unsigned char tx_buf[2] = { 0x50, 0x00 };
 241         unsigned char rx_buf[10];
 242         unsigned int rx_len = sizeof(rx_buf);
 243
 244         ret = iso14443a_transcieve(handle, RFID_14443A_FRAME_REGULAR,
 245                                    tx_buf, sizeof(tx_buf),
 246                                    rx_buf, &rx_len, 1000 /* 1ms */, 0);
 247         if (ret < 0) {
 248                 /* "error" case: we don't get somethng back from the card */
 249                 return 0;
 250         }
 251         return -1;
 252 }
 253
 254 static int
 255 iso14443a_setopt(struct rfid_layer2_handle *handle, int optname,
 256                  const void *optval, unsigned int optlen)
 257 {
 258         int ret = -EINVAL;
 259         struct rfid_reader *rdr = handle->rh->reader;
 260         unsigned int speed;
 261
 262         switch (optname) {
 263         case RFID_OPT_14443A_SPEED_RX:
 264                 if (!rdr->iso14443a.set_speed)
 265                         return -ENOTSUP;
 266                 speed = *(unsigned int *)optval;
 267                 ret = rdr->iso14443a.set_speed(handle->rh, 0, speed);
 268                 break;
 269         case RFID_OPT_14443A_SPEED_TX:
 270                 if (!rdr->iso14443a.set_speed)
 271                         return -ENOTSUP;
 272                 speed = *(unsigned int *)optval;
 273                 ret = rdr->iso14443a.set_speed(handle->rh, 1, speed);
 274                 break;
 275         };
 276
 277         return ret;
 278 }
 279
 280
 281 static struct rfid_layer2_handle *
 282 iso14443a_init(struct rfid_reader_handle *rh)
 283 {
 284         int ret;
 285         struct rfid_layer2_handle *h = malloc(sizeof(*h));
 286         if (!h)
 287                 return NULL;
 288
 289         h->l2 = &rfid_layer2_iso14443a;
 290         h->rh = rh;
 291         h->priv.iso14443a.state = ISO14443A_STATE_NONE;
 292         h->priv.iso14443a.level = ISO14443A_LEVEL_NONE;
 293
 294         ret = h->rh->reader->iso14443a.init(h->rh);
 295         if (ret < 0) {
 296                 free(h);
 297                 return NULL;
 298         }
 299
 300         return h;
 301 }
 302
 303 static int
 304 iso14443a_fini(struct rfid_layer2_handle *handle)
 305 {
 306         free(handle);
 307         return 0;
 308 }
 309
 310
 311 struct rfid_layer2 rfid_layer2_iso14443a = {
 312         .id     = RFID_LAYER2_ISO14443A,
 313         .name   = "ISO 14443-3 A",
 314         .fn     = {
 315                 .init           = &iso14443a_init,
 316                 .open           = &iso14443a_anticol,
 317                 .transcieve     = &iso14443a_transcieve,
 318                 .close          = &iso14443a_hlta,
 319                 .fini           = &iso14443a_fini,
 320                 .setopt         = &iso14443a_setopt,
 321         },
 322 };
 323