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