LXR linux/drivers/nfc/st21nfca/se.c

   1/*
   2 * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
   3 *
   4 * This program is free software; you can redistribute it and/or modify it
   5 * under the terms and conditions of the GNU General Public License,
   6 * version 2, as published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope that it will be useful,
   9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11 * GNU General Public License for more details.
  12 *
  13 * You should have received a copy of the GNU General Public License
  14 * along with this program; if not, see <http://www.gnu.org/licenses/>.
  15 */
  16
  17#include <net/nfc/hci.h>
  18
  19#include "st21nfca.h"
  20
  21#define ST21NFCA_EVT_UICC_ACTIVATE              0x10
  22#define ST21NFCA_EVT_UICC_DEACTIVATE            0x13
  23#define ST21NFCA_EVT_SE_HARD_RESET              0x20
  24#define ST21NFCA_EVT_SE_SOFT_RESET              0x11
  25#define ST21NFCA_EVT_SE_END_OF_APDU_TRANSFER    0x21
  26#define ST21NFCA_EVT_SE_ACTIVATE                0x22
  27#define ST21NFCA_EVT_SE_DEACTIVATE              0x23
  28
  29#define ST21NFCA_EVT_TRANSMIT_DATA              0x10
  30#define ST21NFCA_EVT_WTX_REQUEST                0x11
  31
  32#define ST21NFCA_EVT_CONNECTIVITY               0x10
  33#define ST21NFCA_EVT_TRANSACTION                0x12
  34
  35#define ST21NFCA_ESE_HOST_ID                    0xc0
  36
  37#define ST21NFCA_SE_TO_HOT_PLUG                 1000
  38/* Connectivity pipe only */
  39#define ST21NFCA_SE_COUNT_PIPE_UICC             0x01
  40/* Connectivity + APDU Reader pipe */
  41#define ST21NFCA_SE_COUNT_PIPE_EMBEDDED 0x02
  42
  43#define ST21NFCA_SE_MODE_OFF                    0x00
  44#define ST21NFCA_SE_MODE_ON                             0x01
  45
  46#define ST21NFCA_PARAM_ATR                              0x01
  47#define ST21NFCA_ATR_DEFAULT_BWI                0x04
  48
  49/*
  50 * WT = 2^BWI/10[s], convert into msecs and add a secure
  51 * room by increasing by 2 this timeout
  52 */
  53#define ST21NFCA_BWI_TO_TIMEOUT(x)              ((1 << x) * 200)
  54#define ST21NFCA_ATR_GET_Y_FROM_TD(x)   (x >> 4)
  55
  56/* If TA is present bit 0 is set */
  57#define ST21NFCA_ATR_TA_PRESENT(x) (x & 0x01)
  58/* If TB is present bit 1 is set */
  59#define ST21NFCA_ATR_TB_PRESENT(x) (x & 0x02)
  60
  61static u8 st21nfca_se_get_bwi(struct nfc_hci_dev *hdev)
  62{
  63        int i;
  64        u8 td;
  65        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
  66
  67        /* Bits 8 to 5 of the first TB for T=1 encode BWI from zero to nine */
  68        for (i = 1; i < ST21NFCA_ESE_MAX_LENGTH; i++) {
  69                td = ST21NFCA_ATR_GET_Y_FROM_TD(info->se_info.atr[i]);
  70                if (ST21NFCA_ATR_TA_PRESENT(td))
  71                        i++;
  72                if (ST21NFCA_ATR_TB_PRESENT(td)) {
  73                        i++;
  74                        return info->se_info.atr[i] >> 4;
  75                }
  76        }
  77        return ST21NFCA_ATR_DEFAULT_BWI;
  78}
  79
  80static void st21nfca_se_get_atr(struct nfc_hci_dev *hdev)
  81{
  82        int r;
  83        struct sk_buff *skb;
  84        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
  85
  86        r = nfc_hci_get_param(hdev, ST21NFCA_APDU_READER_GATE,
  87                        ST21NFCA_PARAM_ATR, &skb);
  88        if (r < 0)
  89                return;
  90
  91        if (skb->len <= ST21NFCA_ESE_MAX_LENGTH) {
  92                memcpy(info->se_info.atr, skb->data, skb->len);
  93                info->se_info.wt_timeout =
  94                        ST21NFCA_BWI_TO_TIMEOUT(st21nfca_se_get_bwi(hdev));
  95        }
  96        kfree_skb(skb);
  97}
  98
  99static int st21nfca_hci_control_se(struct nfc_hci_dev *hdev, u32 se_idx,
 100                                u8 state)
 101{
 102        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 103        int r, i;
 104        struct sk_buff *sk_host_list;
 105        u8 se_event, host_id;
 106
 107        switch (se_idx) {
 108        case NFC_HCI_UICC_HOST_ID:
 109                se_event = (state == ST21NFCA_SE_MODE_ON ?
 110                                        ST21NFCA_EVT_UICC_ACTIVATE :
 111                                        ST21NFCA_EVT_UICC_DEACTIVATE);
 112
 113                info->se_info.count_pipes = 0;
 114                info->se_info.expected_pipes = ST21NFCA_SE_COUNT_PIPE_UICC;
 115                break;
 116        case ST21NFCA_ESE_HOST_ID:
 117                se_event = (state == ST21NFCA_SE_MODE_ON ?
 118                                        ST21NFCA_EVT_SE_ACTIVATE :
 119                                        ST21NFCA_EVT_SE_DEACTIVATE);
 120
 121                info->se_info.count_pipes = 0;
 122                info->se_info.expected_pipes = ST21NFCA_SE_COUNT_PIPE_EMBEDDED;
 123                break;
 124        default:
 125                return -EINVAL;
 126        }
 127
 128        /*
 129         * Wait for an EVT_HOT_PLUG in order to
 130         * retrieve a relevant host list.
 131         */
 132        reinit_completion(&info->se_info.req_completion);
 133        r = nfc_hci_send_event(hdev, ST21NFCA_DEVICE_MGNT_GATE, se_event,
 134                               NULL, 0);
 135        if (r < 0)
 136                return r;
 137
 138        mod_timer(&info->se_info.se_active_timer, jiffies +
 139                msecs_to_jiffies(ST21NFCA_SE_TO_HOT_PLUG));
 140        info->se_info.se_active = true;
 141
 142        /* Ignore return value and check in any case the host_list */
 143        wait_for_completion_interruptible(&info->se_info.req_completion);
 144
 145        r = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,
 146                        NFC_HCI_ADMIN_HOST_LIST,
 147                        &sk_host_list);
 148        if (r < 0)
 149                return r;
 150
 151        for (i = 0; i < sk_host_list->len &&
 152                sk_host_list->data[i] != se_idx; i++)
 153                ;
 154        host_id = sk_host_list->data[i];
 155        kfree_skb(sk_host_list);
 156
 157        if (state == ST21NFCA_SE_MODE_ON && host_id == se_idx)
 158                return se_idx;
 159        else if (state == ST21NFCA_SE_MODE_OFF && host_id != se_idx)
 160                return se_idx;
 161
 162        return -1;
 163}
 164
 165int st21nfca_hci_discover_se(struct nfc_hci_dev *hdev)
 166{
 167        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 168        int se_count = 0;
 169
 170        if (test_bit(ST21NFCA_FACTORY_MODE, &hdev->quirks))
 171                return 0;
 172
 173        if (info->se_status->is_uicc_present) {
 174                nfc_add_se(hdev->ndev, NFC_HCI_UICC_HOST_ID, NFC_SE_UICC);
 175                se_count++;
 176        }
 177
 178        if (info->se_status->is_ese_present) {
 179                nfc_add_se(hdev->ndev, ST21NFCA_ESE_HOST_ID, NFC_SE_EMBEDDED);
 180                se_count++;
 181        }
 182
 183        return !se_count;
 184}
 185EXPORT_SYMBOL(st21nfca_hci_discover_se);
 186
 187int st21nfca_hci_enable_se(struct nfc_hci_dev *hdev, u32 se_idx)
 188{
 189        int r;
 190
 191        /*
 192         * According to upper layer, se_idx == NFC_SE_UICC when
 193         * info->se_status->is_uicc_enable is true should never happen.
 194         * Same for eSE.
 195         */
 196        r = st21nfca_hci_control_se(hdev, se_idx, ST21NFCA_SE_MODE_ON);
 197        if (r == ST21NFCA_ESE_HOST_ID) {
 198                st21nfca_se_get_atr(hdev);
 199                r = nfc_hci_send_event(hdev, ST21NFCA_APDU_READER_GATE,
 200                                ST21NFCA_EVT_SE_SOFT_RESET, NULL, 0);
 201                if (r < 0)
 202                        return r;
 203        } else if (r < 0) {
 204                /*
 205                 * The activation tentative failed, the secure element
 206                 * is not connected. Remove from the list.
 207                 */
 208                nfc_remove_se(hdev->ndev, se_idx);
 209                return r;
 210        }
 211
 212        return 0;
 213}
 214EXPORT_SYMBOL(st21nfca_hci_enable_se);
 215
 216int st21nfca_hci_disable_se(struct nfc_hci_dev *hdev, u32 se_idx)
 217{
 218        int r;
 219
 220        /*
 221         * According to upper layer, se_idx == NFC_SE_UICC when
 222         * info->se_status->is_uicc_enable is true should never happen
 223         * Same for eSE.
 224         */
 225        r = st21nfca_hci_control_se(hdev, se_idx, ST21NFCA_SE_MODE_OFF);
 226        if (r < 0)
 227                return r;
 228
 229        return 0;
 230}
 231EXPORT_SYMBOL(st21nfca_hci_disable_se);
 232
 233int st21nfca_hci_se_io(struct nfc_hci_dev *hdev, u32 se_idx,
 234                        u8 *apdu, size_t apdu_length,
 235                        se_io_cb_t cb, void *cb_context)
 236{
 237        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 238
 239        pr_debug("se_io %x\n", se_idx);
 240
 241        switch (se_idx) {
 242        case ST21NFCA_ESE_HOST_ID:
 243                info->se_info.cb = cb;
 244                info->se_info.cb_context = cb_context;
 245                mod_timer(&info->se_info.bwi_timer, jiffies +
 246                          msecs_to_jiffies(info->se_info.wt_timeout));
 247                info->se_info.bwi_active = true;
 248                return nfc_hci_send_event(hdev, ST21NFCA_APDU_READER_GATE,
 249                                        ST21NFCA_EVT_TRANSMIT_DATA,
 250                                        apdu, apdu_length);
 251        default:
 252                return -ENODEV;
 253        }
 254}
 255EXPORT_SYMBOL(st21nfca_hci_se_io);
 256
 257static void st21nfca_se_wt_timeout(unsigned long data)
 258{
 259        /*
 260         * No answer from the secure element
 261         * within the defined timeout.
 262         * Let's send a reset request as recovery procedure.
 263         * According to the situation, we first try to send a software reset
 264         * to the secure element. If the next command is still not
 265         * answering in time, we send to the CLF a secure element hardware
 266         * reset request.
 267         */
 268        /* hardware reset managed through VCC_UICC_OUT power supply */
 269        u8 param = 0x01;
 270        struct st21nfca_hci_info *info = (struct st21nfca_hci_info *) data;
 271
 272        pr_debug("\n");
 273
 274        info->se_info.bwi_active = false;
 275
 276        if (!info->se_info.xch_error) {
 277                info->se_info.xch_error = true;
 278                nfc_hci_send_event(info->hdev, ST21NFCA_APDU_READER_GATE,
 279                                ST21NFCA_EVT_SE_SOFT_RESET, NULL, 0);
 280        } else {
 281                info->se_info.xch_error = false;
 282                nfc_hci_send_event(info->hdev, ST21NFCA_DEVICE_MGNT_GATE,
 283                                ST21NFCA_EVT_SE_HARD_RESET, &param, 1);
 284        }
 285        info->se_info.cb(info->se_info.cb_context, NULL, 0, -ETIME);
 286}
 287
 288static void st21nfca_se_activation_timeout(unsigned long data)
 289{
 290        struct st21nfca_hci_info *info = (struct st21nfca_hci_info *) data;
 291
 292        pr_debug("\n");
 293
 294        info->se_info.se_active = false;
 295
 296        complete(&info->se_info.req_completion);
 297}
 298
 299/*
 300 * Returns:
 301 * <= 0: driver handled the event, skb consumed
 302 *    1: driver does not handle the event, please do standard processing
 303 */
 304int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
 305                                u8 event, struct sk_buff *skb)
 306{
 307        int r = 0;
 308        struct device *dev = &hdev->ndev->dev;
 309        struct nfc_evt_transaction *transaction;
 310
 311        pr_debug("connectivity gate event: %x\n", event);
 312
 313        switch (event) {
 314        case ST21NFCA_EVT_CONNECTIVITY:
 315                r = nfc_se_connectivity(hdev->ndev, host);
 316        break;
 317        case ST21NFCA_EVT_TRANSACTION:
 318                /*
 319                 * According to specification etsi 102 622
 320                 * 11.2.2.4 EVT_TRANSACTION Table 52
 321                 * Description  Tag     Length
 322                 * AID          81      5 to 16
 323                 * PARAMETERS   82      0 to 255
 324                 */
 325                if (skb->len < NFC_MIN_AID_LENGTH + 2 &&
 326                    skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG)
 327                        return -EPROTO;
 328
 329                transaction = (struct nfc_evt_transaction *)devm_kzalloc(dev,
 330                                                   skb->len - 2, GFP_KERNEL);
 331
 332                transaction->aid_len = skb->data[1];
 333                memcpy(transaction->aid, &skb->data[2],
 334                       transaction->aid_len);
 335
 336                /* Check next byte is PARAMETERS tag (82) */
 337                if (skb->data[transaction->aid_len + 2] !=
 338                    NFC_EVT_TRANSACTION_PARAMS_TAG)
 339                        return -EPROTO;
 340
 341                transaction->params_len = skb->data[transaction->aid_len + 3];
 342                memcpy(transaction->params, skb->data +
 343                       transaction->aid_len + 4, transaction->params_len);
 344
 345                r = nfc_se_transaction(hdev->ndev, host, transaction);
 346        break;
 347        default:
 348                nfc_err(&hdev->ndev->dev, "Unexpected event on connectivity gate\n");
 349                return 1;
 350        }
 351        kfree_skb(skb);
 352        return r;
 353}
 354EXPORT_SYMBOL(st21nfca_connectivity_event_received);
 355
 356int st21nfca_apdu_reader_event_received(struct nfc_hci_dev *hdev,
 357                                        u8 event, struct sk_buff *skb)
 358{
 359        int r = 0;
 360        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 361
 362        pr_debug("apdu reader gate event: %x\n", event);
 363
 364        switch (event) {
 365        case ST21NFCA_EVT_TRANSMIT_DATA:
 366                del_timer_sync(&info->se_info.bwi_timer);
 367                info->se_info.bwi_active = false;
 368                r = nfc_hci_send_event(hdev, ST21NFCA_DEVICE_MGNT_GATE,
 369                                ST21NFCA_EVT_SE_END_OF_APDU_TRANSFER, NULL, 0);
 370                if (r < 0)
 371                        goto exit;
 372
 373                info->se_info.cb(info->se_info.cb_context,
 374                        skb->data, skb->len, 0);
 375                break;
 376        case ST21NFCA_EVT_WTX_REQUEST:
 377                mod_timer(&info->se_info.bwi_timer, jiffies +
 378                                msecs_to_jiffies(info->se_info.wt_timeout));
 379                break;
 380        default:
 381                nfc_err(&hdev->ndev->dev, "Unexpected event on apdu reader gate\n");
 382                return 1;
 383        }
 384
 385exit:
 386        kfree_skb(skb);
 387        return r;
 388}
 389EXPORT_SYMBOL(st21nfca_apdu_reader_event_received);
 390
 391void st21nfca_se_init(struct nfc_hci_dev *hdev)
 392{
 393        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 394
 395        init_completion(&info->se_info.req_completion);
 396        /* initialize timers */
 397        init_timer(&info->se_info.bwi_timer);
 398        info->se_info.bwi_timer.data = (unsigned long)info;
 399        info->se_info.bwi_timer.function = st21nfca_se_wt_timeout;
 400        info->se_info.bwi_active = false;
 401
 402        init_timer(&info->se_info.se_active_timer);
 403        info->se_info.se_active_timer.data = (unsigned long)info;
 404        info->se_info.se_active_timer.function = st21nfca_se_activation_timeout;
 405        info->se_info.se_active = false;
 406
 407        info->se_info.count_pipes = 0;
 408        info->se_info.expected_pipes = 0;
 409
 410        info->se_info.xch_error = false;
 411
 412        info->se_info.wt_timeout =
 413                        ST21NFCA_BWI_TO_TIMEOUT(ST21NFCA_ATR_DEFAULT_BWI);
 414}
 415EXPORT_SYMBOL(st21nfca_se_init);
 416
 417void st21nfca_se_deinit(struct nfc_hci_dev *hdev)
 418{
 419        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 420
 421        if (info->se_info.bwi_active)
 422                del_timer_sync(&info->se_info.bwi_timer);
 423        if (info->se_info.se_active)
 424                del_timer_sync(&info->se_info.se_active_timer);
 425
 426        info->se_info.bwi_active = false;
 427        info->se_info.se_active = false;
 428}
 429EXPORT_SYMBOL(st21nfca_se_deinit);
 430