git.rot13.org Git - librfid/blob - 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
  26 #include <rfid/rfid.h>
  27 #include <rfid/rfid_layer2.h>
  28 #include <rfid/rfid_reader.h>
  29 #include <rfid/rfid_layer2_iso14443a.h>
  30
  31 #define TIMEOUT 1236
  32
  33 /* Transcieve a 7-bit short frame */
  34 static int
  35 iso14443a_transcieve_sf(struct rfid_layer2_handle *handle,
  36                          unsigned char cmd,
  37                          struct iso14443a_atqa *atqa)
  38 {
  39         struct rfid_reader *rdr = handle->rh->reader;
  40
  41         return rdr->iso14443a.transcieve_sf(handle->rh, cmd, atqa);
  42 }
  43
  44 /* Transmit an anticollission bit frame */
  45 static int
  46 iso14443a_transcieve_acf(struct rfid_layer2_handle *handle,
  47                          struct iso14443a_anticol_cmd *acf,
  48                          unsigned int *bit_of_col)
  49 {
  50         struct rfid_reader *rdr = handle->rh->reader;
  51
  52         return rdr->iso14443a.transcieve_acf(handle->rh, acf, bit_of_col);
  53 }
  54
  55 /* Transmit a regular frame */
  56 static int
  57 iso14443a_transcieve(struct rfid_layer2_handle *handle,
  58                      enum rfid_frametype frametype,
  59                         const unsigned char *tx_buf, unsigned int tx_len,
  60                         unsigned char *rx_buf, unsigned int *rx_len,
  61                         u_int64_t timeout, unsigned int flags)
  62 {
  63         return handle->rh->reader->transcieve(handle->rh, frametype, tx_buf,
  64                                         tx_len, rx_buf, rx_len, timeout, flags);
  65 }
  66
  67 static int
  68 iso14443a_code_nvb_bits(unsigned char *nvb, unsigned int bits)
  69 {
  70         unsigned int byte_count = bits / 8;
  71         unsigned int bit_count = bits % 8;
  72
  73         if (byte_count < 2 || byte_count > 7)
  74                 return -1;
  75
  76         *nvb = ((byte_count & 0xf) << 4) | bit_count;
  77
  78         return 0;
  79 }
  80
  81 /* first bit is '1', second bit '2' */
  82 static void
  83 set_bit_in_field(unsigned char *bitfield, unsigned int bit)
  84 {
  85         unsigned int byte_count = bit / 8;
  86         unsigned int bit_count = bit % 8;
  87
  88         DEBUGP("bitfield=%p, byte_count=%u, bit_count=%u\n",
  89                         bitfield, byte_count, bit_count);
  90         DEBUGP("%p = 0x%02x\n", (bitfield+byte_count), *(bitfield+byte_count));
  91         *(bitfield+byte_count) |= 1 << (bit_count-1);
  92         DEBUGP("%p = 0x%02x\n", (bitfield+byte_count), *(bitfield+byte_count));
  93 }
  94
  95 static int
  96 iso14443a_anticol(struct rfid_layer2_handle *handle)
  97 {
  98         int ret;
  99         unsigned int uid_size;
 100         struct iso14443a_handle *h = &handle->priv.iso14443a;
 101         struct iso14443a_atqa atqa;
 102         struct iso14443a_anticol_cmd acf;
 103         unsigned int bit_of_col;
 104         unsigned char sak[3];
 105         unsigned int rx_len = sizeof(sak);
 106         char *aqptr = (char *) &atqa;
 107
 108         memset(handle->uid, 0, sizeof(handle->uid));
 109         memset(sak, 0, sizeof(sak));
 110         memset(&atqa, 0, sizeof(atqa));
 111         memset(&acf, 0, sizeof(acf));
 112
 113         ret = iso14443a_transcieve_sf(handle, ISO14443A_SF_CMD_REQA, &atqa);
 114         if (ret < 0) {
 115                 h->state = ISO14443A_STATE_REQA_SENT;
 116                 DEBUGP("error during transcieve_sf: %d\n", ret);
 117                 return ret;
 118         }
 119         h->state = ISO14443A_STATE_ATQA_RCVD;
 120
 121         DEBUGP("ATQA: 0x%02x 0x%02x\n", *aqptr, *(aqptr+1));
 122
 123         if (!atqa.bf_anticol) {
 124                 h->state = ISO14443A_STATE_NO_BITFRAME_ANTICOL;
 125                 DEBUGP("no bitframe anticollission bits set, aborting\n");
 126                 return -1;
 127         }
 128
 129         if (atqa.uid_size == 2 || atqa.uid_size == 3)
 130                 uid_size = 3;
 131         else if (atqa.uid_size == 1)
 132                 uid_size = 2;
 133         else
 134                 uid_size = 1;
 135
 136         acf.sel_code = ISO14443A_AC_SEL_CODE_CL1;
 137
 138         h->state = ISO14443A_STATE_ANTICOL_RUNNING;
 139         h->level = ISO14443A_LEVEL_CL1;
 140
 141 cascade:
 142         iso14443a_code_nvb_bits(&acf.nvb, 16);
 143
 144         ret = iso14443a_transcieve_acf(handle, &acf, &bit_of_col);
 145         if (ret < 0)
 146                 return ret;
 147         DEBUGP("bit_of_col = %u\n", bit_of_col);
 148
 149         while (bit_of_col != ISO14443A_BITOFCOL_NONE) {
 150                 set_bit_in_field(&acf.uid_bits[0], bit_of_col-16);
 151                 iso14443a_code_nvb_bits(&acf.nvb, bit_of_col);
 152                 ret = iso14443a_transcieve_acf(handle, &acf, &bit_of_col);
 153                 DEBUGP("bit_of_col = %u\n", bit_of_col);
 154                 if (ret < 0)
 155                         return ret;
 156         }
 157
 158         iso14443a_code_nvb_bits(&acf.nvb, 7*8);
 159         ret = iso14443a_transcieve(handle, RFID_14443A_FRAME_REGULAR,
 160                                    (unsigned char *)&acf, 7,
 161                                    (unsigned char *) &sak, &rx_len,
 162                                    TIMEOUT, 0);
 163         if (ret < 0)
 164                 return ret;
 165
 166         if (sak[0] & 0x04) {
 167                 /* Cascade bit set, UID not complete */
 168                 switch (acf.sel_code) {
 169                 case ISO14443A_AC_SEL_CODE_CL1:
 170                         /* cascading from CL1 to CL2 */
 171                         if (acf.uid_bits[0] != 0x88) {
 172                                 DEBUGP("Cascade bit set, but UID0 != 0x88\n");
 173                                 return -1;
 174                         }
 175                         memcpy(&handle->uid[0], &acf.uid_bits[1], 3);
 176                         acf.sel_code = ISO14443A_AC_SEL_CODE_CL2;
 177                         h->level = ISO14443A_LEVEL_CL2;
 178                         break;
 179                 case ISO14443A_AC_SEL_CODE_CL2:
 180                         /* cascading from CL2 to CL3 */
 181                         memcpy(&handle->uid[3], &acf.uid_bits[1], 3);
 182                         acf.sel_code = ISO14443A_AC_SEL_CODE_CL3;
 183                         h->level = ISO14443A_LEVEL_CL3;
 184                         break;
 185                 default:
 186                         DEBUGP("cannot cascade any further than CL3\n");
 187                         h->state = ISO14443A_STATE_ERROR;
 188                         return -1;
 189                         break;
 190                 }
 191                 goto cascade;
 192
 193         } else {
 194                 switch (acf.sel_code) {
 195                 case ISO14443A_AC_SEL_CODE_CL1:
 196                         /* single size UID (4 bytes) */
 197                         memcpy(&handle->uid[0], &acf.uid_bits[0], 4);
 198                         break;
 199                 case ISO14443A_AC_SEL_CODE_CL2:
 200                         /* double size UID (7 bytes) */
 201                         memcpy(&handle->uid[3], &acf.uid_bits[0], 4);
 202                         break;
 203                 case ISO14443A_AC_SEL_CODE_CL3:
 204                         /* triple size UID (10 bytes) */
 205                         memcpy(&handle->uid[6], &acf.uid_bits[0], 4);
 206                         break;
 207                 }
 208         }
 209
 210         h->level = ISO14443A_LEVEL_NONE;
 211         h->state = ISO14443A_STATE_SELECTED;
 212
 213         {
 214                 if (uid_size == 1)
 215                         handle->uid_len = 4;
 216                 else if (uid_size == 2)
 217                         handle->uid_len = 7;
 218                 else
 219                         handle->uid_len = 10;
 220
 221                 DEBUGP("UID %s\n", rfid_hexdump(handle->uid, handle->uid_len));
 222         }
 223
 224         if (sak[0] & 0x20) {
 225                 DEBUGP("we have a T=CL compliant PICC\n");
 226                 h->tcl_capable = 1;
 227         } else {
 228                 DEBUGP("we have a T!=CL PICC\n");
 229                 h->tcl_capable = 0;
 230         }
 231
 232         return 0;
 233 }
 234
 235 static int
 236 iso14443a_hlta(struct rfid_layer2_handle *handle)
 237 {
 238         int ret;
 239         unsigned char tx_buf[2] = { 0x50, 0x00 };
 240         unsigned char rx_buf[10];
 241         unsigned int rx_len = sizeof(rx_buf);
 242
 243         ret = iso14443a_transcieve(handle, RFID_14443A_FRAME_REGULAR,
 244                                    tx_buf, sizeof(tx_buf),
 245                                    rx_buf, &rx_len, 1000 /* 1ms */, 0);
 246         if (ret < 0) {
 247                 /* "error" case: we don't get somethng back from the card */
 248                 return 0;
 249         }
 250         return -1;
 251 }
 252
 253 static struct rfid_layer2_handle *
 254 iso14443a_init(struct rfid_reader_handle *rh)
 255 {
 256         int ret;
 257         struct rfid_layer2_handle *h = malloc(sizeof(*h));
 258         if (!h)
 259                 return NULL;
 260
 261         h->l2 = &rfid_layer2_iso14443a;
 262         h->rh = rh;
 263         h->priv.iso14443a.state = ISO14443A_STATE_NONE;
 264         h->priv.iso14443a.level = ISO14443A_LEVEL_NONE;
 265
 266         ret = h->rh->reader->iso14443a.init(h->rh);
 267         if (ret < 0) {
 268                 free(h);
 269                 return NULL;
 270         }
 271
 272         return h;
 273 }
 274
 275 static int
 276 iso14443a_fini(struct rfid_layer2_handle *handle)
 277 {
 278         free(handle);
 279         return 0;
 280 }
 281
 282
 283 struct rfid_layer2 rfid_layer2_iso14443a = {
 284         .id     = RFID_LAYER2_ISO14443A,
 285         .name   = "ISO 14443-3 A",
 286         .fn     = {
 287                 .init           = &iso14443a_init,
 288                 .open           = &iso14443a_anticol,
 289                 .transcieve     = &iso14443a_transcieve,
 290                 .close          = &iso14443a_hlta,
 291                 .fini           = &iso14443a_fini,
 292         },
 293 };
 294