src/rfid_layer2_iso15693.c

   1 /* ISO 15693 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_iso15693.h>
  30
  31 #if 0
  32 /* Transcieve a 7-bit short frame */
  33 static int
  34 iso14443a_transcieve_sf(struct rfid_layer2_handle *handle,
  35                          unsigned char cmd,
  36                          struct iso14443a_atqa *atqa)
  37 {
  38         struct rfid_reader *rdr = handle->rh->reader;
  39
  40         return rdr->iso14443a.transcieve_sf(handle->rh, cmd, atqa);
  41 }
  42
  43 /* Transmit an anticollission bit frame */
  44 static int
  45 iso14443a_transcieve_acf(struct rfid_layer2_handle *handle,
  46                          struct iso14443a_anticol_cmd *acf,
  47                          unsigned int *bit_of_col)
  48 {
  49         struct rfid_reader *rdr = handle->rh->reader;
  50
  51         return rdr->iso14443a.transcieve_acf(handle->rh, acf, bit_of_col);
  52 }
  53
  54 /* Transmit a regular frame */
  55 static int
  56 iso14443a_transcieve(struct rfid_layer2_handle *handle,
  57                         const unsigned char *tx_buf, unsigned int tx_len,
  58                         unsigned char *rx_buf, unsigned int *rx_len,
  59                         u_int64_t, unsigned int flags)
  60 {
  61         return handle->rh->reader->transcieve(handle->rh, tx_buf, tx_len,
  62                                                 rx_buf, rx_len, timeout, flags);
  63 }
  64
  65 static int
  66 iso14443a_code_nvb_bits(unsigned char *nvb, unsigned int bits)
  67 {
  68         unsigned int byte_count = bits / 8;
  69         unsigned int bit_count = bits % 8;
  70
  71         if (byte_count < 2 || byte_count > 7)
  72                 return -1;
  73
  74         *nvb = ((byte_count & 0xf) << 4) | bit_count;
  75
  76         return 0;
  77 }
  78
  79 /* first bit is '1', second bit '2' */
  80 static void
  81 set_bit_in_field(unsigned char *bitfield, unsigned int bit)
  82 {
  83         unsigned int byte_count = bit / 8;
  84         unsigned int bit_count = bit % 8;
  85
  86         DEBUGP("bitfield=%p, byte_count=%u, bit_count=%u\n",
  87                         bitfield, byte_count, bit_count);
  88         DEBUGP("%p = 0x%02x\n", (bitfield+byte_count), *(bitfield+byte_count));
  89         *(bitfield+byte_count) |= 1 << (bit_count-1);
  90         DEBUGP("%p = 0x%02x\n", (bitfield+byte_count), *(bitfield+byte_count));
  91 }
  92
  93 static int
  94 iso14443a_anticol(struct rfid_layer2_handle *handle)
  95 {
  96         int ret;
  97         unsigned int uid_size;
  98         struct iso14443a_atqa atqa;
  99         struct iso14443a_anticol_cmd acf;
 100         unsigned int bit_of_col;
 101         unsigned char sak[3];
 102         unsigned char uid[10];  // triple size equals 10 bytes;
 103         unsigned int rx_len = sizeof(sak);
 104         char *aqptr = (char *) &atqa;
 105         static int first = 0;
 106
 107         memset(uid, 0, sizeof(uid));
 108         memset(sak, 0, sizeof(sak));
 109         memset(&atqa, 0, sizeof(atqa));
 110         memset(&acf, 0, sizeof(acf));
 111
 112         if (first == 0) {
 113         DEBUGP("Sending REQA\n");
 114         ret = iso14443a_transcieve_sf(handle, ISO14443A_SF_CMD_REQA, &atqa);
 115         first = 1;
 116         } else {
 117         DEBUGP("Sending WUPA\n");
 118         ret = iso14443a_transcieve_sf(handle, ISO14443A_SF_CMD_WUPA, &atqa);
 119         }
 120
 121         if (ret < 0) {
 122                 handle->priv.iso14443a.state = ISO14443A_STATE_REQA_SENT;
 123                 DEBUGP("error during transcieve_sf: %d\n", ret);
 124                 return ret;
 125         }
 126         handle->priv.iso14443a.state = ISO14443A_STATE_ATQA_RCVD;
 127
 128         DEBUGP("ATQA: 0x%02x 0x%02x\n", *aqptr, *(aqptr+1));
 129
 130         if (!atqa.bf_anticol) {
 131                 handle->priv.iso14443a.state =ISO14443A_STATE_NO_BITFRAME_ANTICOL;
 132                 DEBUGP("no bitframe anticollission bits set, aborting\n");
 133                 return -1;
 134         }
 135
 136         if (atqa.uid_size == 2 || atqa.uid_size == 3)
 137                 uid_size = 3;
 138         else if (atqa.uid_size == 1)
 139                 uid_size = 2;
 140         else
 141                 uid_size = 1;
 142
 143         acf.sel_code = ISO14443A_AC_SEL_CODE_CL1;
 144
 145         handle->priv.iso14443a.state = ISO14443A_STATE_ANTICOL_RUNNING;
 146         handle->priv.iso14443a.level = ISO14443A_LEVEL_CL1;
 147
 148 cascade:
 149         iso14443a_code_nvb_bits(&acf.nvb, 16);
 150
 151         ret = iso14443a_transcieve_acf(handle, &acf, &bit_of_col);
 152         if (ret < 0)
 153                 return ret;
 154         DEBUGP("bit_of_col = %u\n", bit_of_col);
 155
 156         while (bit_of_col != ISO14443A_BITOFCOL_NONE) {
 157                 set_bit_in_field(&acf.uid_bits[0], bit_of_col-16);
 158                 iso14443a_code_nvb_bits(&acf.nvb, bit_of_col);
 159                 ret = iso14443a_transcieve_acf(handle, &acf, &bit_of_col);
 160                 DEBUGP("bit_of_col = %u\n", bit_of_col);
 161                 if (ret < 0)
 162                         return ret;
 163         }
 164
 165         iso14443a_code_nvb_bits(&acf.nvb, 7*8);
 166         ret = iso14443a_transcieve(handle, (unsigned char *)&acf, 7,
 167                                    (unsigned char *) &sak, &rx_len,
 168                                    TIMEOUT, 0);
 169         if (ret < 0)
 170                 return ret;
 171
 172         if (sak[0] & 0x04) {
 173                 /* Cascade bit set, UID not complete */
 174                 switch (acf.sel_code) {
 175                 case ISO14443A_AC_SEL_CODE_CL1:
 176                         /* cascading from CL1 to CL2 */
 177                         if (acf.uid_bits[0] != 0x88) {
 178                                 DEBUGP("Cascade bit set, but UID0 != 0x88\n");
 179                                 return -1;
 180                         }
 181                         memcpy(&uid[0], &acf.uid_bits[1], 3);
 182                         acf.sel_code = ISO14443A_AC_SEL_CODE_CL2;
 183                         handle->priv.iso14443a.level = ISO14443A_LEVEL_CL2;
 184                         break;
 185                 case ISO14443A_AC_SEL_CODE_CL2:
 186                         /* cascading from CL2 to CL3 */
 187                         memcpy(&uid[3], &acf.uid_bits[1], 3);
 188                         acf.sel_code = ISO14443A_AC_SEL_CODE_CL3;
 189                         handle->priv.iso14443a.level = ISO14443A_LEVEL_CL3;
 190                         break;
 191                 default:
 192                         DEBUGP("cannot cascade any further than CL3\n");
 193                         handle->priv.iso14443a.state = ISO14443A_STATE_ERROR;
 194                         return -1;
 195                         break;
 196                 }
 197                 goto cascade;
 198
 199         } else {
 200                 switch (acf.sel_code) {
 201                 case ISO14443A_AC_SEL_CODE_CL1:
 202                         /* single size UID (4 bytes) */
 203                         memcpy(&uid[0], &acf.uid_bits[0], 4);
 204                         break;
 205                 case ISO14443A_AC_SEL_CODE_CL2:
 206                         /* double size UID (7 bytes) */
 207                         memcpy(&uid[3], &acf.uid_bits[0], 4);
 208                         break;
 209                 case ISO14443A_AC_SEL_CODE_CL3:
 210                         /* triple size UID (10 bytes) */
 211                         memcpy(&uid[6], &acf.uid_bits[0], 4);
 212                         break;
 213                 }
 214         }
 215
 216         handle->priv.iso14443a.level = ISO14443A_LEVEL_NONE;
 217         handle->priv.iso14443a.state = ISO14443A_STATE_SELECTED;
 218
 219         {
 220                 int uid_len;
 221                 if (uid_size == 1)
 222                         uid_len = 4;
 223                 else if (uid_size == 2)
 224                         uid_len = 7;
 225                 else
 226                         uid_len = 10;
 227
 228                 DEBUGP("UID %s\n", rfid_hexdump(uid, uid_len));
 229         }
 230
 231         if (sak[0] & 0x20) {
 232                 DEBUGP("we have a T=CL compliant PICC\n");
 233                 handle->priv.iso14443a.tcl_capable = 1;
 234         } else {
 235                 DEBUGP("we have a T!=CL PICC\n");
 236                 handle->priv.iso14443a.tcl_capable = 0;
 237         }
 238
 239         return 0;
 240 }
 241
 242 static int
 243 iso14443a_hlta(struct rfid_layer2_handle *handle)
 244 {
 245         int ret;
 246         unsigned char tx_buf[2] = { 0x50, 0x00 };
 247         unsigned char rx_buf[10];
 248         unsigned int rx_len = sizeof(rx_buf);
 249
 250         return 0;
 251
 252         ret = iso14443a_transcieve(handle, tx_buf, sizeof(tx_buf),
 253                                    rx_buf, &rx_len, 1000 /* 1ms */, 0);
 254         if (ret < 0) {
 255                 /* "error" case: we don't get somethng back from the card */
 256                 return 0;
 257         }
 258         return -1;
 259 }
 260 #endif
 261
 262 static struct rfid_layer2_handle *
 263 iso15693_init(struct rfid_reader_handle *rh)
 264 {
 265         int ret;
 266         struct rfid_layer2_handle *h = malloc(sizeof(*h));
 267         if (!h)
 268                 return NULL;
 269
 270         h->l2 = &rfid_layer2_iso15693;
 271         h->rh = rh;
 272         h->priv.iso15693.state = ISO15693_STATE_NONE;
 273
 274         ret = h->rh->reader->iso15693.init(h->rh);
 275         if (ret < 0) {
 276                 free(h);
 277                 return NULL;
 278         }
 279
 280         return h;
 281 }
 282
 283 static int
 284 iso15693_fini(struct rfid_layer2_handle *handle)
 285 {
 286         free(handle);
 287         return 0;
 288 }
 289
 290
 291 struct rfid_layer2 rfid_layer2_iso15693 = {
 292         .id     = RFID_LAYER2_ISO15693,
 293         .name   = "ISO 15693",
 294         .fn     = {
 295                 .init           = &iso15693_init,
 296                 //.open                 = &iso15693_anticol,
 297                 //.transcieve   = &iso15693_transcieve,
 298                 //.close                = &iso14443a_hlta,
 299                 .fini           = &iso15693_fini,
 300         },
 301 };
 302