drivers/nfc/st21nfca/se.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
   4  */
   5
   6 #include <net/nfc/hci.h>
   7
   8 #include "st21nfca.h"
   9
  10 #define ST21NFCA_EVT_UICC_ACTIVATE              0x10
  11 #define ST21NFCA_EVT_UICC_DEACTIVATE            0x13
  12 #define ST21NFCA_EVT_SE_HARD_RESET              0x20
  13 #define ST21NFCA_EVT_SE_SOFT_RESET              0x11
  14 #define ST21NFCA_EVT_SE_END_OF_APDU_TRANSFER    0x21
  15 #define ST21NFCA_EVT_SE_ACTIVATE                0x22
  16 #define ST21NFCA_EVT_SE_DEACTIVATE              0x23
  17
  18 #define ST21NFCA_EVT_TRANSMIT_DATA              0x10
  19 #define ST21NFCA_EVT_WTX_REQUEST                0x11
  20
  21 #define ST21NFCA_EVT_CONNECTIVITY               0x10
  22 #define ST21NFCA_EVT_TRANSACTION                0x12
  23
  24 #define ST21NFCA_SE_TO_HOT_PLUG                 1000
  25 /* Connectivity pipe only */
  26 #define ST21NFCA_SE_COUNT_PIPE_UICC             0x01
  27 /* Connectivity + APDU Reader pipe */
  28 #define ST21NFCA_SE_COUNT_PIPE_EMBEDDED 0x02
  29
  30 #define ST21NFCA_SE_MODE_OFF                    0x00
  31 #define ST21NFCA_SE_MODE_ON                             0x01
  32
  33 #define ST21NFCA_PARAM_ATR                              0x01
  34 #define ST21NFCA_ATR_DEFAULT_BWI                0x04
  35
  36 /*
  37  * WT = 2^BWI/10[s], convert into msecs and add a secure
  38  * room by increasing by 2 this timeout
  39  */
  40 #define ST21NFCA_BWI_TO_TIMEOUT(x)              ((1 << x) * 200)
  41 #define ST21NFCA_ATR_GET_Y_FROM_TD(x)   (x >> 4)
  42
  43 /* If TA is present bit 0 is set */
  44 #define ST21NFCA_ATR_TA_PRESENT(x) (x & 0x01)
  45 /* If TB is present bit 1 is set */
  46 #define ST21NFCA_ATR_TB_PRESENT(x) (x & 0x02)
  47
  48 static u8 st21nfca_se_get_bwi(struct nfc_hci_dev *hdev)
  49 {
  50         int i;
  51         u8 td;
  52         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
  53
  54         /* Bits 8 to 5 of the first TB for T=1 encode BWI from zero to nine */
  55         for (i = 1; i < ST21NFCA_ESE_MAX_LENGTH; i++) {
  56                 td = ST21NFCA_ATR_GET_Y_FROM_TD(info->se_info.atr[i]);
  57                 if (ST21NFCA_ATR_TA_PRESENT(td))
  58                         i++;
  59                 if (ST21NFCA_ATR_TB_PRESENT(td)) {
  60                         i++;
  61                         return info->se_info.atr[i] >> 4;
  62                 }
  63         }
  64         return ST21NFCA_ATR_DEFAULT_BWI;
  65 }
  66
  67 static void st21nfca_se_get_atr(struct nfc_hci_dev *hdev)
  68 {
  69         int r;
  70         struct sk_buff *skb;
  71         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
  72
  73         r = nfc_hci_get_param(hdev, ST21NFCA_APDU_READER_GATE,
  74                         ST21NFCA_PARAM_ATR, &skb);
  75         if (r < 0)
  76                 return;
  77
  78         if (skb->len <= ST21NFCA_ESE_MAX_LENGTH) {
  79                 memcpy(info->se_info.atr, skb->data, skb->len);
  80                 info->se_info.wt_timeout =
  81                         ST21NFCA_BWI_TO_TIMEOUT(st21nfca_se_get_bwi(hdev));
  82         }
  83         kfree_skb(skb);
  84 }
  85
  86 static int st21nfca_hci_control_se(struct nfc_hci_dev *hdev, u32 se_idx,
  87                                 u8 state)
  88 {
  89         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
  90         int r, i;
  91         struct sk_buff *sk_host_list;
  92         u8 se_event, host_id;
  93
  94         switch (se_idx) {
  95         case NFC_HCI_UICC_HOST_ID:
  96                 se_event = (state == ST21NFCA_SE_MODE_ON ?
  97                                         ST21NFCA_EVT_UICC_ACTIVATE :
  98                                         ST21NFCA_EVT_UICC_DEACTIVATE);
  99
 100                 info->se_info.count_pipes = 0;
 101                 info->se_info.expected_pipes = ST21NFCA_SE_COUNT_PIPE_UICC;
 102                 break;
 103         case ST21NFCA_ESE_HOST_ID:
 104                 se_event = (state == ST21NFCA_SE_MODE_ON ?
 105                                         ST21NFCA_EVT_SE_ACTIVATE :
 106                                         ST21NFCA_EVT_SE_DEACTIVATE);
 107
 108                 info->se_info.count_pipes = 0;
 109                 info->se_info.expected_pipes = ST21NFCA_SE_COUNT_PIPE_EMBEDDED;
 110                 break;
 111         default:
 112                 return -EINVAL;
 113         }
 114
 115         /*
 116          * Wait for an EVT_HOT_PLUG in order to
 117          * retrieve a relevant host list.
 118          */
 119         reinit_completion(&info->se_info.req_completion);
 120         r = nfc_hci_send_event(hdev, ST21NFCA_DEVICE_MGNT_GATE, se_event,
 121                                NULL, 0);
 122         if (r < 0)
 123                 return r;
 124
 125         mod_timer(&info->se_info.se_active_timer, jiffies +
 126                 msecs_to_jiffies(ST21NFCA_SE_TO_HOT_PLUG));
 127         info->se_info.se_active = true;
 128
 129         /* Ignore return value and check in any case the host_list */
 130         wait_for_completion_interruptible(&info->se_info.req_completion);
 131
 132         r = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,
 133                         NFC_HCI_ADMIN_HOST_LIST,
 134                         &sk_host_list);
 135         if (r < 0)
 136                 return r;
 137
 138         for (i = 0; i < sk_host_list->len &&
 139                 sk_host_list->data[i] != se_idx; i++)
 140                 ;
 141         host_id = sk_host_list->data[i];
 142         kfree_skb(sk_host_list);
 143
 144         if (state == ST21NFCA_SE_MODE_ON && host_id == se_idx)
 145                 return se_idx;
 146         else if (state == ST21NFCA_SE_MODE_OFF && host_id != se_idx)
 147                 return se_idx;
 148
 149         return -1;
 150 }
 151
 152 int st21nfca_hci_discover_se(struct nfc_hci_dev *hdev)
 153 {
 154         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 155         int se_count = 0;
 156
 157         if (test_bit(ST21NFCA_FACTORY_MODE, &hdev->quirks))
 158                 return 0;
 159
 160         if (info->se_status->is_uicc_present) {
 161                 nfc_add_se(hdev->ndev, NFC_HCI_UICC_HOST_ID, NFC_SE_UICC);
 162                 se_count++;
 163         }
 164
 165         if (info->se_status->is_ese_present) {
 166                 nfc_add_se(hdev->ndev, ST21NFCA_ESE_HOST_ID, NFC_SE_EMBEDDED);
 167                 se_count++;
 168         }
 169
 170         return !se_count;
 171 }
 172 EXPORT_SYMBOL(st21nfca_hci_discover_se);
 173
 174 int st21nfca_hci_enable_se(struct nfc_hci_dev *hdev, u32 se_idx)
 175 {
 176         int r;
 177
 178         /*
 179          * According to upper layer, se_idx == NFC_SE_UICC when
 180          * info->se_status->is_uicc_enable is true should never happen.
 181          * Same for eSE.
 182          */
 183         r = st21nfca_hci_control_se(hdev, se_idx, ST21NFCA_SE_MODE_ON);
 184         if (r == ST21NFCA_ESE_HOST_ID) {
 185                 st21nfca_se_get_atr(hdev);
 186                 r = nfc_hci_send_event(hdev, ST21NFCA_APDU_READER_GATE,
 187                                 ST21NFCA_EVT_SE_SOFT_RESET, NULL, 0);
 188                 if (r < 0)
 189                         return r;
 190         } else if (r < 0) {
 191                 /*
 192                  * The activation tentative failed, the secure element
 193                  * is not connected. Remove from the list.
 194                  */
 195                 nfc_remove_se(hdev->ndev, se_idx);
 196                 return r;
 197         }
 198
 199         return 0;
 200 }
 201 EXPORT_SYMBOL(st21nfca_hci_enable_se);
 202
 203 int st21nfca_hci_disable_se(struct nfc_hci_dev *hdev, u32 se_idx)
 204 {
 205         int r;
 206
 207         /*
 208          * According to upper layer, se_idx == NFC_SE_UICC when
 209          * info->se_status->is_uicc_enable is true should never happen
 210          * Same for eSE.
 211          */
 212         r = st21nfca_hci_control_se(hdev, se_idx, ST21NFCA_SE_MODE_OFF);
 213         if (r < 0)
 214                 return r;
 215
 216         return 0;
 217 }
 218 EXPORT_SYMBOL(st21nfca_hci_disable_se);
 219
 220 int st21nfca_hci_se_io(struct nfc_hci_dev *hdev, u32 se_idx,
 221                         u8 *apdu, size_t apdu_length,
 222                         se_io_cb_t cb, void *cb_context)
 223 {
 224         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 225
 226         pr_debug("se_io %x\n", se_idx);
 227
 228         switch (se_idx) {
 229         case ST21NFCA_ESE_HOST_ID:
 230                 info->se_info.cb = cb;
 231                 info->se_info.cb_context = cb_context;
 232                 mod_timer(&info->se_info.bwi_timer, jiffies +
 233                           msecs_to_jiffies(info->se_info.wt_timeout));
 234                 info->se_info.bwi_active = true;
 235                 return nfc_hci_send_event(hdev, ST21NFCA_APDU_READER_GATE,
 236                                         ST21NFCA_EVT_TRANSMIT_DATA,
 237                                         apdu, apdu_length);
 238         default:
 239                 return -ENODEV;
 240         }
 241 }
 242 EXPORT_SYMBOL(st21nfca_hci_se_io);
 243
 244 static void st21nfca_se_wt_work(struct work_struct *work)
 245 {
 246         /*
 247          * No answer from the secure element
 248          * within the defined timeout.
 249          * Let's send a reset request as recovery procedure.
 250          * According to the situation, we first try to send a software reset
 251          * to the secure element. If the next command is still not
 252          * answering in time, we send to the CLF a secure element hardware
 253          * reset request.
 254          */
 255         /* hardware reset managed through VCC_UICC_OUT power supply */
 256         u8 param = 0x01;
 257         struct st21nfca_hci_info *info = container_of(work,
 258                                                 struct st21nfca_hci_info,
 259                                                 se_info.timeout_work);
 260
 261         pr_debug("\n");
 262
 263         info->se_info.bwi_active = false;
 264
 265         if (!info->se_info.xch_error) {
 266                 info->se_info.xch_error = true;
 267                 nfc_hci_send_event(info->hdev, ST21NFCA_APDU_READER_GATE,
 268                                 ST21NFCA_EVT_SE_SOFT_RESET, NULL, 0);
 269         } else {
 270                 info->se_info.xch_error = false;
 271                 nfc_hci_send_event(info->hdev, ST21NFCA_DEVICE_MGNT_GATE,
 272                                 ST21NFCA_EVT_SE_HARD_RESET, &param, 1);
 273         }
 274         info->se_info.cb(info->se_info.cb_context, NULL, 0, -ETIME);
 275 }
 276
 277 static void st21nfca_se_wt_timeout(struct timer_list *t)
 278 {
 279         struct st21nfca_hci_info *info = from_timer(info, t, se_info.bwi_timer);
 280
 281         schedule_work(&info->se_info.timeout_work);
 282 }
 283
 284 static void st21nfca_se_activation_timeout(struct timer_list *t)
 285 {
 286         struct st21nfca_hci_info *info = from_timer(info, t,
 287                                                     se_info.se_active_timer);
 288
 289         pr_debug("\n");
 290
 291         info->se_info.se_active = false;
 292
 293         complete(&info->se_info.req_completion);
 294 }
 295
 296 /*
 297  * Returns:
 298  * <= 0: driver handled the event, skb consumed
 299  *    1: driver does not handle the event, please do standard processing
 300  */
 301 int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
 302                                 u8 event, struct sk_buff *skb)
 303 {
 304         int r = 0;
 305         struct device *dev = &hdev->ndev->dev;
 306         struct nfc_evt_transaction *transaction;
 307         u32 aid_len;
 308         u8 params_len;
 309
 310         pr_debug("connectivity gate event: %x\n", event);
 311
 312         switch (event) {
 313         case ST21NFCA_EVT_CONNECTIVITY:
 314                 r = nfc_se_connectivity(hdev->ndev, host);
 315         break;
 316         case ST21NFCA_EVT_TRANSACTION:
 317                 /* According to specification etsi 102 622
 318                  * 11.2.2.4 EVT_TRANSACTION Table 52
 319                  * Description  Tag     Length
 320                  * AID          81      5 to 16
 321                  * PARAMETERS   82      0 to 255
 322                  *
 323                  * The key differences are aid storage length is variably sized
 324                  * in the packet, but fixed in nfc_evt_transaction, and that the aid_len
 325                  * is u8 in the packet, but u32 in the structure, and the tags in
 326                  * the packet are not included in nfc_evt_transaction.
 327                  *
 328                  * size in bytes: 1          1       5-16 1             1           0-255
 329                  * offset:        0          1       2    aid_len + 2   aid_len + 3 aid_len + 4
 330                  * member name:   aid_tag(M) aid_len aid  params_tag(M) params_len  params
 331                  * example:       0x81       5-16    X    0x82 0-255    X
 332                  */
 333                 if (skb->len < 2 || skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG)
 334                         return -EPROTO;
 335
 336                 aid_len = skb->data[1];
 337
 338                 if (skb->len < aid_len + 4 || aid_len > sizeof(transaction->aid))
 339                         return -EPROTO;
 340
 341                 params_len = skb->data[aid_len + 3];
 342
 343                 /* Verify PARAMETERS tag is (82), and final check that there is enough
 344                  * space in the packet to read everything.
 345                  */
 346                 if ((skb->data[aid_len + 2] != NFC_EVT_TRANSACTION_PARAMS_TAG) ||
 347                     (skb->len < aid_len + 4 + params_len))
 348                         return -EPROTO;
 349
 350                 transaction = devm_kzalloc(dev, sizeof(*transaction) + params_len, GFP_KERNEL);
 351                 if (!transaction)
 352                         return -ENOMEM;
 353
 354                 transaction->aid_len = aid_len;
 355                 transaction->params_len = params_len;
 356
 357                 memcpy(transaction->aid, &skb->data[2], aid_len);
 358                 memcpy(transaction->params, &skb->data[aid_len + 4], params_len);
 359
 360                 r = nfc_se_transaction(hdev->ndev, host, transaction);
 361         break;
 362         default:
 363                 nfc_err(&hdev->ndev->dev, "Unexpected event on connectivity gate\n");
 364                 return 1;
 365         }
 366         kfree_skb(skb);
 367         return r;
 368 }
 369 EXPORT_SYMBOL(st21nfca_connectivity_event_received);
 370
 371 int st21nfca_apdu_reader_event_received(struct nfc_hci_dev *hdev,
 372                                         u8 event, struct sk_buff *skb)
 373 {
 374         int r = 0;
 375         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 376
 377         pr_debug("apdu reader gate event: %x\n", event);
 378
 379         switch (event) {
 380         case ST21NFCA_EVT_TRANSMIT_DATA:
 381                 del_timer_sync(&info->se_info.bwi_timer);
 382                 cancel_work_sync(&info->se_info.timeout_work);
 383                 info->se_info.bwi_active = false;
 384                 r = nfc_hci_send_event(hdev, ST21NFCA_DEVICE_MGNT_GATE,
 385                                 ST21NFCA_EVT_SE_END_OF_APDU_TRANSFER, NULL, 0);
 386                 if (r < 0)
 387                         goto exit;
 388
 389                 info->se_info.cb(info->se_info.cb_context,
 390                         skb->data, skb->len, 0);
 391                 break;
 392         case ST21NFCA_EVT_WTX_REQUEST:
 393                 mod_timer(&info->se_info.bwi_timer, jiffies +
 394                                 msecs_to_jiffies(info->se_info.wt_timeout));
 395                 break;
 396         default:
 397                 nfc_err(&hdev->ndev->dev, "Unexpected event on apdu reader gate\n");
 398                 return 1;
 399         }
 400
 401 exit:
 402         kfree_skb(skb);
 403         return r;
 404 }
 405 EXPORT_SYMBOL(st21nfca_apdu_reader_event_received);
 406
 407 void st21nfca_se_init(struct nfc_hci_dev *hdev)
 408 {
 409         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 410
 411         init_completion(&info->se_info.req_completion);
 412         INIT_WORK(&info->se_info.timeout_work, st21nfca_se_wt_work);
 413         /* initialize timers */
 414         timer_setup(&info->se_info.bwi_timer, st21nfca_se_wt_timeout, 0);
 415         info->se_info.bwi_active = false;
 416
 417         timer_setup(&info->se_info.se_active_timer,
 418                     st21nfca_se_activation_timeout, 0);
 419         info->se_info.se_active = false;
 420
 421         info->se_info.count_pipes = 0;
 422         info->se_info.expected_pipes = 0;
 423
 424         info->se_info.xch_error = false;
 425
 426         info->se_info.wt_timeout =
 427                         ST21NFCA_BWI_TO_TIMEOUT(ST21NFCA_ATR_DEFAULT_BWI);
 428 }
 429 EXPORT_SYMBOL(st21nfca_se_init);
 430
 431 void st21nfca_se_deinit(struct nfc_hci_dev *hdev)
 432 {
 433         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 434
 435         if (info->se_info.bwi_active)
 436                 del_timer_sync(&info->se_info.bwi_timer);
 437         if (info->se_info.se_active)
 438                 del_timer_sync(&info->se_info.se_active_timer);
 439
 440         cancel_work_sync(&info->se_info.timeout_work);
 441         info->se_info.bwi_active = false;
 442         info->se_info.se_active = false;
 443 }
 444 EXPORT_SYMBOL(st21nfca_se_deinit);