git.rot13.org Git - librfid/blob - src/rfid_layer2_iso14443a.c

   1 /* ISO 14443-3 A anticollision implementation
   2  *
   3  * (C) 2005-2006 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 #include <librfid/rfid_protocol.h>
  32
  33 #define TIMEOUT 1236
  34
  35 /* Transceive a 7-bit short frame */
  36 static int
  37 iso14443a_transceive_sf(struct rfid_layer2_handle *handle,
  38                          unsigned char cmd,
  39                          struct iso14443a_atqa *atqa)
  40 {
  41         struct rfid_reader *rdr = handle->rh->reader;
  42
  43         return rdr->iso14443a.transceive_sf(handle->rh, cmd, atqa);
  44 }
  45
  46 /* Transmit an anticollission bit frame */
  47 static int
  48 iso14443a_transceive_acf(struct rfid_layer2_handle *handle,
  49                          struct iso14443a_anticol_cmd *acf,
  50                          unsigned int *bit_of_col)
  51 {
  52         struct rfid_reader *rdr = handle->rh->reader;
  53
  54         return rdr->iso14443a.transceive_acf(handle->rh, acf, bit_of_col);
  55 }
  56
  57 /* Transmit a regular frame */
  58 static int
  59 iso14443a_transceive(struct rfid_layer2_handle *handle,
  60                      enum rfid_frametype frametype,
  61                         const unsigned char *tx_buf, unsigned int tx_len,
  62                         unsigned char *rx_buf, unsigned int *rx_len,
  63                         u_int64_t timeout, unsigned int flags)
  64 {
  65         return handle->rh->reader->transceive(handle->rh, frametype, tx_buf,
  66                                         tx_len, rx_buf, rx_len, timeout, flags);
  67 }
  68
  69 static int
  70 iso14443a_code_nvb_bits(unsigned char *nvb, unsigned int bits)
  71 {
  72         unsigned int byte_count = bits / 8;
  73         unsigned int bit_count = bits % 8;
  74
  75         if (byte_count < 2 || byte_count > 7)
  76                 return -1;
  77
  78         *nvb = ((byte_count & 0xf) << 4) | bit_count;
  79
  80         return 0;
  81 }
  82
  83 /* first bit is '1', second bit '2' */
  84 static void
  85 set_bit_in_field(unsigned char *bitfield, unsigned int bit)
  86 {
  87         unsigned int byte_count = bit / 8;
  88         unsigned int bit_count = bit % 8;
  89
  90         DEBUGP("bitfield=%p, byte_count=%u, bit_count=%u\n",
  91                         bitfield, byte_count, bit_count);
  92         DEBUGP("%p = 0x%02x\n", (bitfield+byte_count), *(bitfield+byte_count));
  93         *(bitfield+byte_count) |= 1 << (bit_count-1);
  94         DEBUGP("%p = 0x%02x\n", (bitfield+byte_count), *(bitfield+byte_count));
  95 }
  96
  97 static int
  98 iso14443a_anticol(struct rfid_layer2_handle *handle)
  99 {
 100         int ret;
 101         unsigned int uid_size;
 102         struct iso14443a_handle *h = &handle->priv.iso14443a;
 103         struct iso14443a_atqa atqa;
 104         struct iso14443a_anticol_cmd acf;
 105         unsigned int bit_of_col;
 106         unsigned char sak[3];
 107         unsigned int rx_len = sizeof(sak);
 108         char *aqptr = (char *) &atqa;
 109
 110         memset(handle->uid, 0, sizeof(handle->uid));
 111         memset(sak, 0, sizeof(sak));
 112         memset(&atqa, 0, sizeof(atqa));
 113         memset(&acf, 0, sizeof(acf));
 114
 115         ret = iso14443a_transceive_sf(handle, ISO14443A_SF_CMD_REQA, &atqa);
 116         if (ret < 0) {
 117                 h->state = ISO14443A_STATE_REQA_SENT;
 118                 DEBUGP("error during transceive_sf: %d\n", ret);
 119                 return ret;
 120         }
 121         h->state = ISO14443A_STATE_ATQA_RCVD;
 122
 123         DEBUGP("ATQA: 0x%02x 0x%02x\n", *aqptr, *(aqptr+1));
 124
 125         if (!atqa.bf_anticol) {
 126                 h->state = ISO14443A_STATE_NO_BITFRAME_ANTICOL;
 127                 DEBUGP("no bitframe anticollission bits set, aborting\n");
 128                 return -1;
 129         }
 130
 131         if (atqa.uid_size == 2 || atqa.uid_size == 3)
 132                 uid_size = 3;
 133         else if (atqa.uid_size == 1)
 134                 uid_size = 2;
 135         else
 136                 uid_size = 1;
 137
 138         acf.sel_code = ISO14443A_AC_SEL_CODE_CL1;
 139
 140         h->state = ISO14443A_STATE_ANTICOL_RUNNING;
 141         h->level = ISO14443A_LEVEL_CL1;
 142
 143 cascade:
 144         rx_len = sizeof(sak);
 145         iso14443a_code_nvb_bits(&acf.nvb, 16);
 146
 147         ret = iso14443a_transceive_acf(handle, &acf, &bit_of_col);
 148         if (ret < 0)
 149                 return ret;
 150         DEBUGP("bit_of_col = %u\n", bit_of_col);
 151
 152         while (bit_of_col != ISO14443A_BITOFCOL_NONE) {
 153                 set_bit_in_field(&acf.uid_bits[0], bit_of_col-16);
 154                 iso14443a_code_nvb_bits(&acf.nvb, bit_of_col);
 155                 ret = iso14443a_transceive_acf(handle, &acf, &bit_of_col);
 156                 DEBUGP("bit_of_col = %u\n", bit_of_col);
 157                 if (ret < 0)
 158                         return ret;
 159         }
 160
 161         iso14443a_code_nvb_bits(&acf.nvb, 7*8);
 162         ret = iso14443a_transceive(handle, RFID_14443A_FRAME_REGULAR,
 163                                    (unsigned char *)&acf, 7,
 164                                    (unsigned char *) &sak, &rx_len,
 165                                    TIMEOUT, 0);
 166         if (ret < 0)
 167                 return ret;
 168
 169         if (sak[0] & 0x04) {
 170                 /* Cascade bit set, UID not complete */
 171                 switch (acf.sel_code) {
 172                 case ISO14443A_AC_SEL_CODE_CL1:
 173                         /* cascading from CL1 to CL2 */
 174                         if (acf.uid_bits[0] != 0x88) {
 175                                 DEBUGP("Cascade bit set, but UID0 != 0x88\n");
 176                                 return -1;
 177                         }
 178                         memcpy(&handle->uid[0], &acf.uid_bits[1], 3);
 179                         acf.sel_code = ISO14443A_AC_SEL_CODE_CL2;
 180                         h->level = ISO14443A_LEVEL_CL2;
 181                         break;
 182                 case ISO14443A_AC_SEL_CODE_CL2:
 183                         /* cascading from CL2 to CL3 */
 184                         memcpy(&handle->uid[3], &acf.uid_bits[1], 3);
 185                         acf.sel_code = ISO14443A_AC_SEL_CODE_CL3;
 186                         h->level = ISO14443A_LEVEL_CL3;
 187                         break;
 188                 default:
 189                         DEBUGP("cannot cascade any further than CL3\n");
 190                         h->state = ISO14443A_STATE_ERROR;
 191                         return -1;
 192                         break;
 193                 }
 194                 goto cascade;
 195
 196         } else {
 197                 switch (acf.sel_code) {
 198                 case ISO14443A_AC_SEL_CODE_CL1:
 199                         /* single size UID (4 bytes) */
 200                         memcpy(&handle->uid[0], &acf.uid_bits[0], 4);
 201                         break;
 202                 case ISO14443A_AC_SEL_CODE_CL2:
 203                         /* double size UID (7 bytes) */
 204                         memcpy(&handle->uid[3], &acf.uid_bits[0], 4);
 205                         break;
 206                 case ISO14443A_AC_SEL_CODE_CL3:
 207                         /* triple size UID (10 bytes) */
 208                         memcpy(&handle->uid[6], &acf.uid_bits[0], 4);
 209                         break;
 210                 }
 211         }
 212
 213         h->level = ISO14443A_LEVEL_NONE;
 214         h->state = ISO14443A_STATE_SELECTED;
 215
 216         {
 217                 if (uid_size == 1)
 218                         handle->uid_len = 4;
 219                 else if (uid_size == 2)
 220                         handle->uid_len = 7;
 221                 else
 222                         handle->uid_len = 10;
 223
 224                 DEBUGP("UID %s\n", rfid_hexdump(handle->uid, handle->uid_len));
 225         }
 226
 227         if (sak[0] & 0x20) {
 228                 DEBUGP("we have a T=CL compliant PICC\n");
 229                 handle->proto_supported = 1 << RFID_PROTOCOL_TCL;
 230                 h->tcl_capable = 1;
 231         } else {
 232                 DEBUGP("we have a T!=CL PICC\n");
 233                 handle->proto_supported = (1 << RFID_PROTOCOL_MIFARE_UL)|
 234                                           (1 << RFID_PROTOCOL_MIFARE_CLASSIC);
 235                 h->tcl_capable = 0;
 236         }
 237
 238         return 0;
 239 }
 240
 241 static int
 242 iso14443a_hlta(struct rfid_layer2_handle *handle)
 243 {
 244         int ret;
 245         unsigned char tx_buf[2] = { 0x50, 0x00 };
 246         unsigned char rx_buf[10];
 247         unsigned int rx_len = sizeof(rx_buf);
 248
 249         ret = iso14443a_transceive(handle, RFID_14443A_FRAME_REGULAR,
 250                                    tx_buf, sizeof(tx_buf),
 251                                    rx_buf, &rx_len, 1000 /* 1ms */, 0);
 252         if (ret < 0) {
 253                 /* "error" case: we don't get somethng back from the card */
 254                 return 0;
 255         }
 256         return -1;
 257 }
 258
 259 static int
 260 iso14443a_setopt(struct rfid_layer2_handle *handle, int optname,
 261                  const void *optval, unsigned int optlen)
 262 {
 263         int ret = -EINVAL;
 264         struct rfid_reader *rdr = handle->rh->reader;
 265         unsigned int speed;
 266
 267         switch (optname) {
 268         case RFID_OPT_14443A_SPEED_RX:
 269                 if (!rdr->iso14443a.set_speed)
 270                         return -ENOTSUP;
 271                 speed = *(unsigned int *)optval;
 272                 ret = rdr->iso14443a.set_speed(handle->rh, 0, speed);
 273                 break;
 274         case RFID_OPT_14443A_SPEED_TX:
 275                 if (!rdr->iso14443a.set_speed)
 276                         return -ENOTSUP;
 277                 speed = *(unsigned int *)optval;
 278                 ret = rdr->iso14443a.set_speed(handle->rh, 1, speed);
 279                 break;
 280         };
 281
 282         return ret;
 283 }
 284
 285
 286 static struct rfid_layer2_handle *
 287 iso14443a_init(struct rfid_reader_handle *rh)
 288 {
 289         int ret;
 290         struct rfid_layer2_handle *h = malloc(sizeof(*h));
 291         if (!h)
 292                 return NULL;
 293
 294         h->l2 = &rfid_layer2_iso14443a;
 295         h->rh = rh;
 296         h->priv.iso14443a.state = ISO14443A_STATE_NONE;
 297         h->priv.iso14443a.level = ISO14443A_LEVEL_NONE;
 298
 299         ret = h->rh->reader->iso14443a.init(h->rh);
 300         if (ret < 0) {
 301                 free(h);
 302                 return NULL;
 303         }
 304
 305         return h;
 306 }
 307
 308 static int
 309 iso14443a_fini(struct rfid_layer2_handle *handle)
 310 {
 311         free(handle);
 312         return 0;
 313 }
 314
 315
 316 struct rfid_layer2 rfid_layer2_iso14443a = {
 317         .id     = RFID_LAYER2_ISO14443A,
 318         .name   = "ISO 14443-3 A",
 319         .fn     = {
 320                 .init           = &iso14443a_init,
 321                 .open           = &iso14443a_anticol,
 322                 .transceive     = &iso14443a_transceive,
 323                 .close          = &iso14443a_hlta,
 324                 .fini           = &iso14443a_fini,
 325                 .setopt         = &iso14443a_setopt,
 326         },
 327 };
 328