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