src/rfid_layer2_iso14443b.c

   1 /* ISO 14443-3 B 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
  26 #include <librfid/rfid.h>
  27 #include <librfid/rfid_layer2.h>
  28 #include <librfid/rfid_reader.h>
  29 #include <librfid/rfid_layer2_iso14443b.h>
  30
  31 #include "rfid_iso14443_common.h"
  32
  33 #define ATQB_TIMEOUT    ((256*10e6/ISO14443_FREQ_SUBCARRIER)            \
  34                          +(200*10e6/ISO14443_FREQ_SUBCARRIER))
  35
  36 static inline int
  37 fwi_to_fwt(struct rfid_layer2_handle *h, unsigned int *fwt, unsigned int fwi)
  38 {
  39         unsigned int multiplier, tmp;
  40
  41         /* 15 is RFU */
  42         if (fwi > 14)
  43                 return -1;
  44
  45         /* According to ISO 14443-3:200(E), Chapter 7.9.4.3, the forumala is
  46          * (256 * 16 / fC) * 2^fwi We avoid floating point computations by
  47          * shifting everything into the microsecond range.  In integer
  48          * calculations 1000000*256*16/13560000 evaluates to 302 (instead of
  49          * 302.064897), which provides sufficient precision, IMHO.  The max
  50          * result is 302 * 16384 (4947968), which fits well within the 31/32
  51          * bit range of an integer */
  52
  53         multiplier = 1 << fwi;          /* 2 to the power of fwi */
  54
  55         tmp = (unsigned int) 1000000 * 256 * 16;
  56
  57         return (tmp / h->rh->ah->asic->fc) * multiplier;
  58 }
  59
  60 static int
  61 parse_atqb(struct rfid_layer2_handle *h, struct iso14443b_atqb *atqb)
  62 {
  63         int ret;
  64
  65         if (atqb->fifty != 0x50)
  66                 return -1;
  67
  68         if (atqb->protocol_info.fo & 0x01)
  69                 h->priv.iso14443b.flags |= ISO14443B_CID_SUPPORTED;
  70         if (atqb->protocol_info.fo & 0x02)
  71                 h->priv.iso14443b.flags |= ISO14443B_NAD_SUPPORTED;
  72
  73         ret = fwi_to_fwt(h, &h->priv.iso14443b.fwt, atqb->protocol_info.fwi);
  74         if (ret < 0) {
  75                 DEBUGP("invalid fwi %u\n", atqb->protocol_info.fwi);
  76                 return ret;
  77         }
  78
  79         if (atqb->protocol_info.protocol_type == 0x1) {
  80                 DEBUGP("we have a T=CL compliant PICC\n");
  81                 h->priv.iso14443b.tcl_capable = 1;
  82         } else {
  83                 DEBUGP("we have a T!=CL PICC\n");
  84                 h->priv.iso14443b.tcl_capable = 0;
  85         }
  86
  87         iso14443_fsdi_to_fsd(&h->priv.iso14443b.fsc,
  88                              atqb->protocol_info.max_frame_size);
  89
  90         /* FIXME: speed capability */
  91
  92         memcpy(h->uid, atqb->pupi, sizeof(atqb->pupi));
  93         h->uid_len = sizeof(atqb->pupi);
  94
  95         return 0;
  96 }
  97
  98 static int
  99 send_reqb(struct rfid_layer2_handle *h, unsigned char afi,
 100           unsigned int is_wup, unsigned int num_initial_slots)
 101 {
 102         int ret;
 103         unsigned char reqb[3];
 104         struct iso14443b_atqb atqb;
 105         unsigned int atqb_len = sizeof(atqb);
 106         unsigned int num_slot_idx = num_initial_slots;
 107
 108         reqb[0] = 0x05;
 109         reqb[1] = afi;
 110
 111         for (num_slot_idx = num_initial_slots; num_slot_idx <= 4;
 112              num_slot_idx++) {
 113                 reqb[2] = num_slot_idx & 0x07;
 114                 if (is_wup)
 115                         reqb[2] |= 0x08;
 116
 117                 ret = h->rh->reader->transcieve(h->rh, RFID_14443B_FRAME_REGULAR,
 118                                                 reqb, sizeof(reqb),
 119                                                  (unsigned char *)&atqb,
 120                                                  &atqb_len, ATQB_TIMEOUT, 0);
 121                 h->priv.iso14443b.state = ISO14443B_STATE_REQB_SENT;
 122                 if (ret < 0) {
 123                         DEBUGP("error during transcieve of REQB/WUBP\n");
 124                         continue;
 125                 }
 126
 127                 /* FIXME: send N-1 slot marker frames */
 128
 129                 if (atqb_len != sizeof(atqb)) {
 130                         DEBUGP("error: atqb_len = %u instead of %Zu\n",
 131                                 atqb_len, sizeof(atqb));
 132                         continue;
 133                 }
 134
 135                 /* FIXME: how to detect a collission at 14443B ?  I guess we
 136                  * can only rely on the CRC checking (CRCErr in ErrorFlag
 137                  * register?) */
 138
 139                 if (parse_atqb(h, &atqb) >= 0) {
 140                         h->priv.iso14443b.state = ISO14443B_STATE_ATQB_RCVD;
 141                         return 0;
 142                 }
 143         }
 144
 145         return -1;
 146 }
 147
 148 static inline unsigned int mbli_to_mbl(struct rfid_layer2_handle *h,
 149                                         unsigned int mbli)
 150 {
 151         return (h->priv.iso14443b.fsc * 2 ^ (mbli-1));
 152 }
 153
 154 static int
 155 transcieve_attrib(struct rfid_layer2_handle *h, const unsigned char *inf,
 156             unsigned int inf_len, unsigned char *rx_data, unsigned int *rx_len)
 157 {
 158         struct iso14443b_attrib_hdr *attrib;
 159         unsigned int attrib_size = sizeof(*attrib) + inf_len;
 160         unsigned char *rx_buf;
 161         unsigned char fsdi;
 162         int ret = 0;
 163
 164         DEBUGP("fsd is %u\n", h->priv.iso14443b.fsd);
 165         attrib = malloc(attrib_size);
 166         if (!attrib) {
 167                 perror("attrib_alloc");
 168                 return -1;
 169         }
 170
 171         DEBUGP("fsd is %u\n", h->priv.iso14443b.fsd);
 172         rx_buf = malloc(*rx_len+1);
 173         if (!rx_buf) {
 174                 perror("rx_buf malloc");
 175                 ret = -1;
 176                 goto out_attrib;
 177         }
 178
 179         /* initialize attrib frame */
 180         memset(attrib, 0, attrib_size);
 181         if (inf_len)
 182                 memcpy((unsigned char *)attrib+sizeof(*attrib), inf, inf_len);
 183
 184         attrib->one_d = 0x1d;
 185         memcpy(attrib->identifier, h->uid, 4);
 186
 187         /* FIXME: do we want to change TR0/TR1 from its default ? */
 188         /* FIXME: do we want to change SOF/EOF from its default ? */
 189
 190         ret = iso14443_fsd_to_fsdi(&fsdi, h->priv.iso14443b.fsd);
 191         if (ret < 0) {
 192                 DEBUGP("unable to map FSD(%u) to FSDI\n",
 193                         h->priv.iso14443b.fsd);
 194                 goto out_rx;
 195         }
 196         attrib->param2.fsdi = fsdi;
 197
 198         /* FIXME: spd_in / spd_out */
 199         if (h->priv.iso14443b.tcl_capable == 1)
 200                 attrib->param3.protocol_type = 0x1;
 201
 202         *rx_len = *rx_len + 1;
 203         ret = h->rh->reader->transcieve(h->rh, RFID_14443B_FRAME_REGULAR,
 204                                         (unsigned char *) attrib,
 205                                         sizeof(*attrib)+inf_len,
 206                                         rx_buf, rx_len, h->priv.iso14443b.fwt,
 207                                         0);
 208         h->priv.iso14443b.state = ISO14443B_STATE_ATTRIB_SENT;
 209         if (ret < 0) {
 210                 DEBUGP("transcieve problem\n");
 211                 goto out_rx;
 212         }
 213
 214         if ((rx_buf[0] & 0x0f) != h->priv.iso14443b.cid) {
 215                 DEBUGP("ATTRIB response with invalid CID %u\n",
 216                         rx_buf[0] & 0x0f);
 217                 ret = -1;
 218                 goto out_rx;
 219         }
 220
 221         h->priv.iso14443b.state = ISO14443B_STATE_SELECTED;
 222
 223         h->priv.iso14443b.mbl = mbli_to_mbl(h, (rx_data[0] & 0xf0) >> 4);
 224
 225         *rx_len = *rx_len - 1;
 226         memcpy(rx_data, rx_buf+1, *rx_len);
 227
 228 out_rx:
 229         free(rx_buf);
 230 out_attrib:
 231         free(attrib);
 232
 233         return ret;
 234 }
 235
 236 static int
 237 iso14443b_hltb(struct rfid_layer2_handle *h)
 238 {
 239         int ret;
 240         unsigned char hltb[5];
 241         unsigned char hltb_resp[1];
 242         unsigned int hltb_len = 1;
 243
 244         hltb[0] = 0x50;
 245         memcpy(hltb+1, h->uid, 4);
 246
 247         ret = h->rh->reader->transcieve(h->rh, RFID_14443B_FRAME_REGULAR,
 248                                         hltb, 5,
 249                                         hltb_resp, &hltb_len,
 250                                         h->priv.iso14443b.fwt, 0);
 251         h->priv.iso14443b.state = ISO14443B_STATE_HLTB_SENT;
 252         if (ret < 0) {
 253                 DEBUGP("transcieve problem\n");
 254                 return ret;
 255         }
 256
 257         if (hltb_len != 1 || hltb_resp[0] != 0x00) {
 258                 DEBUGP("bad HLTB response\n");
 259                 return -1;
 260         }
 261         h->priv.iso14443b.state = ISO14443B_STATE_HALTED;
 262
 263         return 0;
 264 }
 265
 266 static int
 267 iso14443b_anticol(struct rfid_layer2_handle *handle)
 268 {
 269         unsigned char afi = 0; /* FIXME */
 270         int ret;
 271         unsigned char buf[255];
 272         unsigned int buf_len = sizeof(buf);
 273
 274         ret = send_reqb(handle, afi, 0, 0);
 275         if (ret < 0)
 276                 return ret;
 277
 278         ret = transcieve_attrib(handle, NULL, 0, buf, &buf_len);
 279         if (ret < 0)
 280                 return ret;
 281
 282         return 0;
 283 }
 284
 285 static struct rfid_layer2_handle *
 286 iso14443b_init(struct rfid_reader_handle *rh)
 287 {
 288         int ret;
 289         struct rfid_layer2_handle *h = malloc(sizeof(*h));
 290         if (!h)
 291                 return NULL;
 292
 293         h->l2 = &rfid_layer2_iso14443b;
 294         h->rh = rh;
 295         h->priv.iso14443b.state = ISO14443B_STATE_NONE;
 296
 297         h->priv.iso14443b.fsd = iso14443_fsd_approx(rh->ah->mru);
 298         DEBUGP("fsd is %u\n", h->priv.iso14443b.fsd);
 299
 300         /* 14443-3 Section 7.1.6 */
 301         h->priv.iso14443b.tr0 = (256/ISO14443_FREQ_SUBCARRIER)*10e6;
 302         h->priv.iso14443b.tr1 = (200/ISO14443_FREQ_SUBCARRIER)*10e6;
 303
 304         ret = h->rh->reader->iso14443b.init(h->rh);
 305         if (ret < 0) {
 306                 DEBUGP("error during reader 14443b init\n");
 307                 free(h);
 308                 return NULL;
 309         }
 310
 311         return h;
 312 }
 313
 314 static int
 315 iso14443b_fini(struct rfid_layer2_handle *handle)
 316 {
 317         free(handle);
 318         return 0;
 319 }
 320
 321 static int
 322 iso14443b_transcieve(struct rfid_layer2_handle *handle,
 323                      enum rfid_frametype frametype,
 324                      const unsigned char *tx_buf, unsigned int tx_len,
 325                      unsigned char *rx_buf, unsigned int *rx_len,
 326                      u_int64_t timeout, unsigned int flags)
 327 {
 328         DEBUGP("transcieving %u bytes, expecting max %u\n", tx_len, *rx_len);
 329         return handle->rh->reader->transcieve(handle->rh, frametype,
 330                                               tx_buf, tx_len,
 331                                               rx_buf, rx_len, timeout, flags);
 332 }
 333
 334 struct rfid_layer2 rfid_layer2_iso14443b = {
 335         .id     = RFID_LAYER2_ISO14443B,
 336         .name   = "ISO 14443-3 B",
 337         .fn     = {
 338                 .init           = &iso14443b_init,
 339                 .open           = &iso14443b_anticol,
 340                 .transcieve     = &iso14443b_transcieve,
 341                 .close          = &iso14443b_hltb,
 342                 .fini           = &iso14443b_fini,
 343         },
 344 };