hw/usb/ccid-card-passthru.c

   1 /*
   2  * CCID Passthru Card Device emulation
   3  *
   4  * Copyright (c) 2011 Red Hat.
   5  * Written by Alon Levy.
   6  *
   7  * This work is licensed under the terms of the GNU GPL, version 2.1 or later.
   8  * See the COPYING file in the top-level directory.
   9  */
  10
  11 #include "qemu/osdep.h"
  12 #include "qemu-common.h"
  13 #include "qemu/units.h"
  14 #include <libcacard.h>
  15 #include "chardev/char-fe.h"
  16 #include "hw/qdev-properties.h"
  17 #include "migration/vmstate.h"
  18 #include "qemu/error-report.h"
  19 #include "qemu/module.h"
  20 #include "qemu/sockets.h"
  21 #include "ccid.h"
  22 #include "qapi/error.h"
  23 #include "qom/object.h"
  24
  25 #define DPRINTF(card, lvl, fmt, ...)                    \
  26 do {                                                    \
  27     if (lvl <= card->debug) {                           \
  28         printf("ccid-card-passthru: " fmt , ## __VA_ARGS__);     \
  29     }                                                   \
  30 } while (0)
  31
  32 #define D_WARN 1
  33 #define D_INFO 2
  34 #define D_MORE_INFO 3
  35 #define D_VERBOSE 4
  36
  37 /* TODO: do we still need this? */
  38 static const uint8_t DEFAULT_ATR[] = {
  39 /*
  40  * From some example somewhere
  41  * 0x3B, 0xB0, 0x18, 0x00, 0xD1, 0x81, 0x05, 0xB1, 0x40, 0x38, 0x1F, 0x03, 0x28
  42  */
  43
  44 /* From an Athena smart card */
  45  0x3B, 0xD5, 0x18, 0xFF, 0x80, 0x91, 0xFE, 0x1F, 0xC3, 0x80, 0x73, 0xC8, 0x21,
  46  0x13, 0x08
  47 };
  48
  49 #define VSCARD_IN_SIZE      (64 * KiB)
  50
  51 /* maximum size of ATR - from 7816-3 */
  52 #define MAX_ATR_SIZE        40
  53
  54 typedef struct PassthruState PassthruState;
  55
  56 struct PassthruState {
  57     CCIDCardState base;
  58     CharBackend cs;
  59     uint8_t  vscard_in_data[VSCARD_IN_SIZE];
  60     uint32_t vscard_in_pos;
  61     uint32_t vscard_in_hdr;
  62     uint8_t  atr[MAX_ATR_SIZE];
  63     uint8_t  atr_length;
  64     uint8_t  debug;
  65 };
  66
  67 #define TYPE_CCID_PASSTHRU "ccid-card-passthru"
  68 DECLARE_INSTANCE_CHECKER(PassthruState, PASSTHRU_CCID_CARD,
  69                          TYPE_CCID_PASSTHRU)
  70
  71 /*
  72  * VSCard protocol over chardev
  73  * This code should not depend on the card type.
  74  */
  75
  76 static void ccid_card_vscard_send_msg(PassthruState *s,
  77         VSCMsgType type, uint32_t reader_id,
  78         const uint8_t *payload, uint32_t length)
  79 {
  80     VSCMsgHeader scr_msg_header;
  81
  82     scr_msg_header.type = htonl(type);
  83     scr_msg_header.reader_id = htonl(reader_id);
  84     scr_msg_header.length = htonl(length);
  85     /* XXX this blocks entire thread. Rewrite to use
  86      * qemu_chr_fe_write and background I/O callbacks */
  87     qemu_chr_fe_write_all(&s->cs, (uint8_t *)&scr_msg_header,
  88                           sizeof(VSCMsgHeader));
  89     qemu_chr_fe_write_all(&s->cs, payload, length);
  90 }
  91
  92 static void ccid_card_vscard_send_apdu(PassthruState *s,
  93     const uint8_t *apdu, uint32_t length)
  94 {
  95     ccid_card_vscard_send_msg(
  96         s, VSC_APDU, VSCARD_MINIMAL_READER_ID, apdu, length);
  97 }
  98
  99 static void ccid_card_vscard_send_error(PassthruState *s,
 100                     uint32_t reader_id, VSCErrorCode code)
 101 {
 102     VSCMsgError msg = {.code = htonl(code)};
 103
 104     ccid_card_vscard_send_msg(
 105         s, VSC_Error, reader_id, (uint8_t *)&msg, sizeof(msg));
 106 }
 107
 108 static void ccid_card_vscard_send_init(PassthruState *s)
 109 {
 110     VSCMsgInit msg = {
 111         .version = htonl(VSCARD_VERSION),
 112         .magic = VSCARD_MAGIC,
 113         .capabilities = {0}
 114     };
 115
 116     ccid_card_vscard_send_msg(s, VSC_Init, VSCARD_UNDEFINED_READER_ID,
 117                          (uint8_t *)&msg, sizeof(msg));
 118 }
 119
 120 static int ccid_card_vscard_can_read(void *opaque)
 121 {
 122     PassthruState *card = opaque;
 123
 124     return VSCARD_IN_SIZE >= card->vscard_in_pos ?
 125            VSCARD_IN_SIZE - card->vscard_in_pos : 0;
 126 }
 127
 128 static void ccid_card_vscard_handle_init(
 129     PassthruState *card, VSCMsgHeader *hdr, VSCMsgInit *init)
 130 {
 131     uint32_t *capabilities;
 132     int num_capabilities;
 133     int i;
 134
 135     capabilities = init->capabilities;
 136     num_capabilities =
 137         1 + ((hdr->length - sizeof(VSCMsgInit)) / sizeof(uint32_t));
 138     init->version = ntohl(init->version);
 139     for (i = 0 ; i < num_capabilities; ++i) {
 140         capabilities[i] = ntohl(capabilities[i]);
 141     }
 142     if (init->magic != VSCARD_MAGIC) {
 143         error_report("wrong magic");
 144         /* we can't disconnect the chardev */
 145     }
 146     if (init->version != VSCARD_VERSION) {
 147         DPRINTF(card, D_WARN,
 148             "got version %d, have %d", init->version, VSCARD_VERSION);
 149     }
 150     /* future handling of capabilities, none exist atm */
 151     ccid_card_vscard_send_init(card);
 152 }
 153
 154 static int check_atr(PassthruState *card, uint8_t *data, int len)
 155 {
 156     int historical_length, opt_bytes;
 157     int td_count = 0;
 158     int td;
 159
 160     if (len < 2) {
 161         return 0;
 162     }
 163     historical_length = data[1] & 0xf;
 164     opt_bytes = 0;
 165     if (data[0] != 0x3b && data[0] != 0x3f) {
 166         DPRINTF(card, D_WARN, "atr's T0 is 0x%X, not in {0x3b, 0x3f}\n",
 167                 data[0]);
 168         return 0;
 169     }
 170     td_count = 0;
 171     td = data[1] >> 4;
 172     while (td && td_count < 2 && opt_bytes + historical_length + 2 < len) {
 173         td_count++;
 174         if (td & 0x1) {
 175             opt_bytes++;
 176         }
 177         if (td & 0x2) {
 178             opt_bytes++;
 179         }
 180         if (td & 0x4) {
 181             opt_bytes++;
 182         }
 183         if (td & 0x8) {
 184             opt_bytes++;
 185             td = data[opt_bytes + 2] >> 4;
 186         }
 187     }
 188     if (len < 2 + historical_length + opt_bytes) {
 189         DPRINTF(card, D_WARN,
 190             "atr too short: len %d, but historical_len %d, T1 0x%X\n",
 191             len, historical_length, data[1]);
 192         return 0;
 193     }
 194     if (len > 2 + historical_length + opt_bytes) {
 195         DPRINTF(card, D_WARN,
 196             "atr too long: len %d, but hist/opt %d/%d, T1 0x%X\n",
 197             len, historical_length, opt_bytes, data[1]);
 198         /* let it through */
 199     }
 200     DPRINTF(card, D_VERBOSE,
 201             "atr passes check: %d total length, %d historical, %d optional\n",
 202             len, historical_length, opt_bytes);
 203
 204     return 1;
 205 }
 206
 207 static void ccid_card_vscard_handle_message(PassthruState *card,
 208     VSCMsgHeader *scr_msg_header)
 209 {
 210     uint8_t *data = (uint8_t *)&scr_msg_header[1];
 211
 212     switch (scr_msg_header->type) {
 213     case VSC_ATR:
 214         DPRINTF(card, D_INFO, "VSC_ATR %d\n", scr_msg_header->length);
 215         if (scr_msg_header->length > MAX_ATR_SIZE) {
 216             error_report("ATR size exceeds spec, ignoring");
 217             ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 218                                         VSC_GENERAL_ERROR);
 219             break;
 220         }
 221         if (!check_atr(card, data, scr_msg_header->length)) {
 222             error_report("ATR is inconsistent, ignoring");
 223             ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 224                                         VSC_GENERAL_ERROR);
 225             break;
 226         }
 227         memcpy(card->atr, data, scr_msg_header->length);
 228         card->atr_length = scr_msg_header->length;
 229         ccid_card_card_inserted(&card->base);
 230         ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 231                                     VSC_SUCCESS);
 232         break;
 233     case VSC_APDU:
 234         ccid_card_send_apdu_to_guest(
 235             &card->base, data, scr_msg_header->length);
 236         break;
 237     case VSC_CardRemove:
 238         DPRINTF(card, D_INFO, "VSC_CardRemove\n");
 239         ccid_card_card_removed(&card->base);
 240         ccid_card_vscard_send_error(card,
 241             scr_msg_header->reader_id, VSC_SUCCESS);
 242         break;
 243     case VSC_Init:
 244         ccid_card_vscard_handle_init(
 245             card, scr_msg_header, (VSCMsgInit *)data);
 246         break;
 247     case VSC_Error:
 248         ccid_card_card_error(&card->base, *(uint32_t *)data);
 249         break;
 250     case VSC_ReaderAdd:
 251         if (ccid_card_ccid_attach(&card->base) < 0) {
 252             ccid_card_vscard_send_error(card, VSCARD_UNDEFINED_READER_ID,
 253                                       VSC_CANNOT_ADD_MORE_READERS);
 254         } else {
 255             ccid_card_vscard_send_error(card, VSCARD_MINIMAL_READER_ID,
 256                                         VSC_SUCCESS);
 257         }
 258         break;
 259     case VSC_ReaderRemove:
 260         ccid_card_ccid_detach(&card->base);
 261         ccid_card_vscard_send_error(card,
 262             scr_msg_header->reader_id, VSC_SUCCESS);
 263         break;
 264     default:
 265         printf("usb-ccid: chardev: unexpected message of type %X\n",
 266                scr_msg_header->type);
 267         ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 268             VSC_GENERAL_ERROR);
 269     }
 270 }
 271
 272 static void ccid_card_vscard_drop_connection(PassthruState *card)
 273 {
 274     qemu_chr_fe_deinit(&card->cs, true);
 275     card->vscard_in_pos = card->vscard_in_hdr = 0;
 276 }
 277
 278 static void ccid_card_vscard_read(void *opaque, const uint8_t *buf, int size)
 279 {
 280     PassthruState *card = opaque;
 281     VSCMsgHeader *hdr;
 282
 283     if (card->vscard_in_pos + size > VSCARD_IN_SIZE) {
 284         error_report("no room for data: pos %u +  size %d > %" PRId64 "."
 285                      " dropping connection.",
 286                      card->vscard_in_pos, size, VSCARD_IN_SIZE);
 287         ccid_card_vscard_drop_connection(card);
 288         return;
 289     }
 290     assert(card->vscard_in_pos < VSCARD_IN_SIZE);
 291     assert(card->vscard_in_hdr < VSCARD_IN_SIZE);
 292     memcpy(card->vscard_in_data + card->vscard_in_pos, buf, size);
 293     card->vscard_in_pos += size;
 294     hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
 295
 296     while ((card->vscard_in_pos - card->vscard_in_hdr >= sizeof(VSCMsgHeader))
 297          &&(card->vscard_in_pos - card->vscard_in_hdr >=
 298                                   sizeof(VSCMsgHeader) + ntohl(hdr->length))) {
 299         hdr->reader_id = ntohl(hdr->reader_id);
 300         hdr->length = ntohl(hdr->length);
 301         hdr->type = ntohl(hdr->type);
 302         ccid_card_vscard_handle_message(card, hdr);
 303         card->vscard_in_hdr += hdr->length + sizeof(VSCMsgHeader);
 304         hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
 305     }
 306     if (card->vscard_in_hdr == card->vscard_in_pos) {
 307         card->vscard_in_pos = card->vscard_in_hdr = 0;
 308     }
 309 }
 310
 311 static void ccid_card_vscard_event(void *opaque, QEMUChrEvent event)
 312 {
 313     PassthruState *card = opaque;
 314
 315     switch (event) {
 316     case CHR_EVENT_BREAK:
 317         card->vscard_in_pos = card->vscard_in_hdr = 0;
 318         break;
 319     case CHR_EVENT_OPENED:
 320         DPRINTF(card, D_INFO, "%s: CHR_EVENT_OPENED\n", __func__);
 321         break;
 322     case CHR_EVENT_MUX_IN:
 323     case CHR_EVENT_MUX_OUT:
 324     case CHR_EVENT_CLOSED:
 325         /* Ignore */
 326         break;
 327     }
 328 }
 329
 330 /* End VSCard handling */
 331
 332 static void passthru_apdu_from_guest(
 333     CCIDCardState *base, const uint8_t *apdu, uint32_t len)
 334 {
 335     PassthruState *card = PASSTHRU_CCID_CARD(base);
 336
 337     if (!qemu_chr_fe_backend_connected(&card->cs)) {
 338         printf("ccid-passthru: no chardev, discarding apdu length %d\n", len);
 339         return;
 340     }
 341     ccid_card_vscard_send_apdu(card, apdu, len);
 342 }
 343
 344 static const uint8_t *passthru_get_atr(CCIDCardState *base, uint32_t *len)
 345 {
 346     PassthruState *card = PASSTHRU_CCID_CARD(base);
 347
 348     *len = card->atr_length;
 349     return card->atr;
 350 }
 351
 352 static void passthru_realize(CCIDCardState *base, Error **errp)
 353 {
 354     PassthruState *card = PASSTHRU_CCID_CARD(base);
 355
 356     card->vscard_in_pos = 0;
 357     card->vscard_in_hdr = 0;
 358     if (qemu_chr_fe_backend_connected(&card->cs)) {
 359         DPRINTF(card, D_INFO, "ccid-card-passthru: initing chardev");
 360         qemu_chr_fe_set_handlers(&card->cs,
 361             ccid_card_vscard_can_read,
 362             ccid_card_vscard_read,
 363             ccid_card_vscard_event, NULL, card, NULL, true);
 364         ccid_card_vscard_send_init(card);
 365     } else {
 366         error_setg(errp, "missing chardev");
 367         return;
 368     }
 369     card->debug = parse_debug_env("QEMU_CCID_PASSTHRU_DEBUG", D_VERBOSE,
 370                                   card->debug);
 371     assert(sizeof(DEFAULT_ATR) <= MAX_ATR_SIZE);
 372     memcpy(card->atr, DEFAULT_ATR, sizeof(DEFAULT_ATR));
 373     card->atr_length = sizeof(DEFAULT_ATR);
 374 }
 375
 376 static VMStateDescription passthru_vmstate = {
 377     .name = "ccid-card-passthru",
 378     .version_id = 1,
 379     .minimum_version_id = 1,
 380     .fields = (VMStateField[]) {
 381         VMSTATE_BUFFER(vscard_in_data, PassthruState),
 382         VMSTATE_UINT32(vscard_in_pos, PassthruState),
 383         VMSTATE_UINT32(vscard_in_hdr, PassthruState),
 384         VMSTATE_BUFFER(atr, PassthruState),
 385         VMSTATE_UINT8(atr_length, PassthruState),
 386         VMSTATE_END_OF_LIST()
 387     }
 388 };
 389
 390 static Property passthru_card_properties[] = {
 391     DEFINE_PROP_CHR("chardev", PassthruState, cs),
 392     DEFINE_PROP_UINT8("debug", PassthruState, debug, 0),
 393     DEFINE_PROP_END_OF_LIST(),
 394 };
 395
 396 static void passthru_class_initfn(ObjectClass *klass, void *data)
 397 {
 398     DeviceClass *dc = DEVICE_CLASS(klass);
 399     CCIDCardClass *cc = CCID_CARD_CLASS(klass);
 400
 401     cc->realize = passthru_realize;
 402     cc->get_atr = passthru_get_atr;
 403     cc->apdu_from_guest = passthru_apdu_from_guest;
 404     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 405     dc->desc = "passthrough smartcard";
 406     dc->vmsd = &passthru_vmstate;
 407     device_class_set_props(dc, passthru_card_properties);
 408 }
 409
 410 static const TypeInfo passthru_card_info = {
 411     .name          = TYPE_CCID_PASSTHRU,
 412     .parent        = TYPE_CCID_CARD,
 413     .instance_size = sizeof(PassthruState),
 414     .class_init    = passthru_class_initfn,
 415 };
 416
 417 static void ccid_card_passthru_register_types(void)
 418 {
 419     type_register_static(&passthru_card_info);
 420 }
 421
 422 type_init(ccid_card_passthru_register_types)