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 "chardev/char-fe.h"
  13 #include "qemu/error-report.h"
  14 #include "qemu/sockets.h"
  15 #include "ccid.h"
  16 #include "cacard/vscard_common.h"
  17
  18 #define DPRINTF(card, lvl, fmt, ...)                    \
  19 do {                                                    \
  20     if (lvl <= card->debug) {                           \
  21         printf("ccid-card-passthru: " fmt , ## __VA_ARGS__);     \
  22     }                                                   \
  23 } while (0)
  24
  25 #define D_WARN 1
  26 #define D_INFO 2
  27 #define D_MORE_INFO 3
  28 #define D_VERBOSE 4
  29
  30 /* TODO: do we still need this? */
  31 static const uint8_t DEFAULT_ATR[] = {
  32 /*
  33  * From some example somewhere
  34  * 0x3B, 0xB0, 0x18, 0x00, 0xD1, 0x81, 0x05, 0xB1, 0x40, 0x38, 0x1F, 0x03, 0x28
  35  */
  36
  37 /* From an Athena smart card */
  38  0x3B, 0xD5, 0x18, 0xFF, 0x80, 0x91, 0xFE, 0x1F, 0xC3, 0x80, 0x73, 0xC8, 0x21,
  39  0x13, 0x08
  40 };
  41
  42 #define VSCARD_IN_SIZE 65536
  43
  44 /* maximum size of ATR - from 7816-3 */
  45 #define MAX_ATR_SIZE        40
  46
  47 typedef struct PassthruState PassthruState;
  48
  49 struct PassthruState {
  50     CCIDCardState base;
  51     CharBackend cs;
  52     uint8_t  vscard_in_data[VSCARD_IN_SIZE];
  53     uint32_t vscard_in_pos;
  54     uint32_t vscard_in_hdr;
  55     uint8_t  atr[MAX_ATR_SIZE];
  56     uint8_t  atr_length;
  57     uint8_t  debug;
  58 };
  59
  60 #define TYPE_CCID_PASSTHRU "ccid-card-passthru"
  61 #define PASSTHRU_CCID_CARD(obj) \
  62     OBJECT_CHECK(PassthruState, (obj), TYPE_CCID_PASSTHRU)
  63
  64 /*
  65  * VSCard protocol over chardev
  66  * This code should not depend on the card type.
  67  */
  68
  69 static void ccid_card_vscard_send_msg(PassthruState *s,
  70         VSCMsgType type, uint32_t reader_id,
  71         const uint8_t *payload, uint32_t length)
  72 {
  73     VSCMsgHeader scr_msg_header;
  74
  75     scr_msg_header.type = htonl(type);
  76     scr_msg_header.reader_id = htonl(reader_id);
  77     scr_msg_header.length = htonl(length);
  78     /* XXX this blocks entire thread. Rewrite to use
  79      * qemu_chr_fe_write and background I/O callbacks */
  80     qemu_chr_fe_write_all(&s->cs, (uint8_t *)&scr_msg_header,
  81                           sizeof(VSCMsgHeader));
  82     qemu_chr_fe_write_all(&s->cs, payload, length);
  83 }
  84
  85 static void ccid_card_vscard_send_apdu(PassthruState *s,
  86     const uint8_t *apdu, uint32_t length)
  87 {
  88     ccid_card_vscard_send_msg(
  89         s, VSC_APDU, VSCARD_MINIMAL_READER_ID, apdu, length);
  90 }
  91
  92 static void ccid_card_vscard_send_error(PassthruState *s,
  93                     uint32_t reader_id, VSCErrorCode code)
  94 {
  95     VSCMsgError msg = {.code = htonl(code)};
  96
  97     ccid_card_vscard_send_msg(
  98         s, VSC_Error, reader_id, (uint8_t *)&msg, sizeof(msg));
  99 }
 100
 101 static void ccid_card_vscard_send_init(PassthruState *s)
 102 {
 103     VSCMsgInit msg = {
 104         .version = htonl(VSCARD_VERSION),
 105         .magic = VSCARD_MAGIC,
 106         .capabilities = {0}
 107     };
 108
 109     ccid_card_vscard_send_msg(s, VSC_Init, VSCARD_UNDEFINED_READER_ID,
 110                          (uint8_t *)&msg, sizeof(msg));
 111 }
 112
 113 static int ccid_card_vscard_can_read(void *opaque)
 114 {
 115     PassthruState *card = opaque;
 116
 117     return VSCARD_IN_SIZE >= card->vscard_in_pos ?
 118            VSCARD_IN_SIZE - card->vscard_in_pos : 0;
 119 }
 120
 121 static void ccid_card_vscard_handle_init(
 122     PassthruState *card, VSCMsgHeader *hdr, VSCMsgInit *init)
 123 {
 124     uint32_t *capabilities;
 125     int num_capabilities;
 126     int i;
 127
 128     capabilities = init->capabilities;
 129     num_capabilities =
 130         1 + ((hdr->length - sizeof(VSCMsgInit)) / sizeof(uint32_t));
 131     init->version = ntohl(init->version);
 132     for (i = 0 ; i < num_capabilities; ++i) {
 133         capabilities[i] = ntohl(capabilities[i]);
 134     }
 135     if (init->magic != VSCARD_MAGIC) {
 136         error_report("wrong magic");
 137         /* we can't disconnect the chardev */
 138     }
 139     if (init->version != VSCARD_VERSION) {
 140         DPRINTF(card, D_WARN,
 141             "got version %d, have %d", init->version, VSCARD_VERSION);
 142     }
 143     /* future handling of capabilities, none exist atm */
 144     ccid_card_vscard_send_init(card);
 145 }
 146
 147 static int check_atr(PassthruState *card, uint8_t *data, int len)
 148 {
 149     int historical_length, opt_bytes;
 150     int td_count = 0;
 151     int td;
 152
 153     if (len < 2) {
 154         return 0;
 155     }
 156     historical_length = data[1] & 0xf;
 157     opt_bytes = 0;
 158     if (data[0] != 0x3b && data[0] != 0x3f) {
 159         DPRINTF(card, D_WARN, "atr's T0 is 0x%X, not in {0x3b, 0x3f}\n",
 160                 data[0]);
 161         return 0;
 162     }
 163     td_count = 0;
 164     td = data[1] >> 4;
 165     while (td && td_count < 2 && opt_bytes + historical_length + 2 < len) {
 166         td_count++;
 167         if (td & 0x1) {
 168             opt_bytes++;
 169         }
 170         if (td & 0x2) {
 171             opt_bytes++;
 172         }
 173         if (td & 0x4) {
 174             opt_bytes++;
 175         }
 176         if (td & 0x8) {
 177             opt_bytes++;
 178             td = data[opt_bytes + 2] >> 4;
 179         }
 180     }
 181     if (len < 2 + historical_length + opt_bytes) {
 182         DPRINTF(card, D_WARN,
 183             "atr too short: len %d, but historical_len %d, T1 0x%X\n",
 184             len, historical_length, data[1]);
 185         return 0;
 186     }
 187     if (len > 2 + historical_length + opt_bytes) {
 188         DPRINTF(card, D_WARN,
 189             "atr too long: len %d, but hist/opt %d/%d, T1 0x%X\n",
 190             len, historical_length, opt_bytes, data[1]);
 191         /* let it through */
 192     }
 193     DPRINTF(card, D_VERBOSE,
 194             "atr passes check: %d total length, %d historical, %d optional\n",
 195             len, historical_length, opt_bytes);
 196
 197     return 1;
 198 }
 199
 200 static void ccid_card_vscard_handle_message(PassthruState *card,
 201     VSCMsgHeader *scr_msg_header)
 202 {
 203     uint8_t *data = (uint8_t *)&scr_msg_header[1];
 204
 205     switch (scr_msg_header->type) {
 206     case VSC_ATR:
 207         DPRINTF(card, D_INFO, "VSC_ATR %d\n", scr_msg_header->length);
 208         if (scr_msg_header->length > MAX_ATR_SIZE) {
 209             error_report("ATR size exceeds spec, ignoring");
 210             ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 211                                         VSC_GENERAL_ERROR);
 212             break;
 213         }
 214         if (!check_atr(card, data, scr_msg_header->length)) {
 215             error_report("ATR is inconsistent, ignoring");
 216             ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 217                                         VSC_GENERAL_ERROR);
 218             break;
 219         }
 220         memcpy(card->atr, data, scr_msg_header->length);
 221         card->atr_length = scr_msg_header->length;
 222         ccid_card_card_inserted(&card->base);
 223         ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 224                                     VSC_SUCCESS);
 225         break;
 226     case VSC_APDU:
 227         ccid_card_send_apdu_to_guest(
 228             &card->base, data, scr_msg_header->length);
 229         break;
 230     case VSC_CardRemove:
 231         DPRINTF(card, D_INFO, "VSC_CardRemove\n");
 232         ccid_card_card_removed(&card->base);
 233         ccid_card_vscard_send_error(card,
 234             scr_msg_header->reader_id, VSC_SUCCESS);
 235         break;
 236     case VSC_Init:
 237         ccid_card_vscard_handle_init(
 238             card, scr_msg_header, (VSCMsgInit *)data);
 239         break;
 240     case VSC_Error:
 241         ccid_card_card_error(&card->base, *(uint32_t *)data);
 242         break;
 243     case VSC_ReaderAdd:
 244         if (ccid_card_ccid_attach(&card->base) < 0) {
 245             ccid_card_vscard_send_error(card, VSCARD_UNDEFINED_READER_ID,
 246                                       VSC_CANNOT_ADD_MORE_READERS);
 247         } else {
 248             ccid_card_vscard_send_error(card, VSCARD_MINIMAL_READER_ID,
 249                                         VSC_SUCCESS);
 250         }
 251         break;
 252     case VSC_ReaderRemove:
 253         ccid_card_ccid_detach(&card->base);
 254         ccid_card_vscard_send_error(card,
 255             scr_msg_header->reader_id, VSC_SUCCESS);
 256         break;
 257     default:
 258         printf("usb-ccid: chardev: unexpected message of type %X\n",
 259                scr_msg_header->type);
 260         ccid_card_vscard_send_error(card, scr_msg_header->reader_id,
 261             VSC_GENERAL_ERROR);
 262     }
 263 }
 264
 265 static void ccid_card_vscard_drop_connection(PassthruState *card)
 266 {
 267     qemu_chr_fe_deinit(&card->cs, true);
 268     card->vscard_in_pos = card->vscard_in_hdr = 0;
 269 }
 270
 271 static void ccid_card_vscard_read(void *opaque, const uint8_t *buf, int size)
 272 {
 273     PassthruState *card = opaque;
 274     VSCMsgHeader *hdr;
 275
 276     if (card->vscard_in_pos + size > VSCARD_IN_SIZE) {
 277         error_report(
 278             "no room for data: pos %d +  size %d > %d. dropping connection.",
 279             card->vscard_in_pos, size, VSCARD_IN_SIZE);
 280         ccid_card_vscard_drop_connection(card);
 281         return;
 282     }
 283     assert(card->vscard_in_pos < VSCARD_IN_SIZE);
 284     assert(card->vscard_in_hdr < VSCARD_IN_SIZE);
 285     memcpy(card->vscard_in_data + card->vscard_in_pos, buf, size);
 286     card->vscard_in_pos += size;
 287     hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
 288
 289     while ((card->vscard_in_pos - card->vscard_in_hdr >= sizeof(VSCMsgHeader))
 290          &&(card->vscard_in_pos - card->vscard_in_hdr >=
 291                                   sizeof(VSCMsgHeader) + ntohl(hdr->length))) {
 292         hdr->reader_id = ntohl(hdr->reader_id);
 293         hdr->length = ntohl(hdr->length);
 294         hdr->type = ntohl(hdr->type);
 295         ccid_card_vscard_handle_message(card, hdr);
 296         card->vscard_in_hdr += hdr->length + sizeof(VSCMsgHeader);
 297         hdr = (VSCMsgHeader *)(card->vscard_in_data + card->vscard_in_hdr);
 298     }
 299     if (card->vscard_in_hdr == card->vscard_in_pos) {
 300         card->vscard_in_pos = card->vscard_in_hdr = 0;
 301     }
 302 }
 303
 304 static void ccid_card_vscard_event(void *opaque, int event)
 305 {
 306     PassthruState *card = opaque;
 307
 308     switch (event) {
 309     case CHR_EVENT_BREAK:
 310         card->vscard_in_pos = card->vscard_in_hdr = 0;
 311         break;
 312     case CHR_EVENT_OPENED:
 313         DPRINTF(card, D_INFO, "%s: CHR_EVENT_OPENED\n", __func__);
 314         break;
 315     }
 316 }
 317
 318 /* End VSCard handling */
 319
 320 static void passthru_apdu_from_guest(
 321     CCIDCardState *base, const uint8_t *apdu, uint32_t len)
 322 {
 323     PassthruState *card = PASSTHRU_CCID_CARD(base);
 324
 325     if (!qemu_chr_fe_backend_connected(&card->cs)) {
 326         printf("ccid-passthru: no chardev, discarding apdu length %d\n", len);
 327         return;
 328     }
 329     ccid_card_vscard_send_apdu(card, apdu, len);
 330 }
 331
 332 static const uint8_t *passthru_get_atr(CCIDCardState *base, uint32_t *len)
 333 {
 334     PassthruState *card = PASSTHRU_CCID_CARD(base);
 335
 336     *len = card->atr_length;
 337     return card->atr;
 338 }
 339
 340 static int passthru_initfn(CCIDCardState *base)
 341 {
 342     PassthruState *card = PASSTHRU_CCID_CARD(base);
 343
 344     card->vscard_in_pos = 0;
 345     card->vscard_in_hdr = 0;
 346     if (qemu_chr_fe_backend_connected(&card->cs)) {
 347         DPRINTF(card, D_INFO, "initing chardev\n");
 348         qemu_chr_fe_set_handlers(&card->cs,
 349             ccid_card_vscard_can_read,
 350             ccid_card_vscard_read,
 351             ccid_card_vscard_event, NULL, card, NULL, true);
 352         ccid_card_vscard_send_init(card);
 353     } else {
 354         error_report("missing chardev");
 355         return -1;
 356     }
 357     card->debug = parse_debug_env("QEMU_CCID_PASSTHRU_DEBUG", D_VERBOSE,
 358                                   card->debug);
 359     assert(sizeof(DEFAULT_ATR) <= MAX_ATR_SIZE);
 360     memcpy(card->atr, DEFAULT_ATR, sizeof(DEFAULT_ATR));
 361     card->atr_length = sizeof(DEFAULT_ATR);
 362     return 0;
 363 }
 364
 365 static VMStateDescription passthru_vmstate = {
 366     .name = "ccid-card-passthru",
 367     .version_id = 1,
 368     .minimum_version_id = 1,
 369     .fields = (VMStateField[]) {
 370         VMSTATE_BUFFER(vscard_in_data, PassthruState),
 371         VMSTATE_UINT32(vscard_in_pos, PassthruState),
 372         VMSTATE_UINT32(vscard_in_hdr, PassthruState),
 373         VMSTATE_BUFFER(atr, PassthruState),
 374         VMSTATE_UINT8(atr_length, PassthruState),
 375         VMSTATE_END_OF_LIST()
 376     }
 377 };
 378
 379 static Property passthru_card_properties[] = {
 380     DEFINE_PROP_CHR("chardev", PassthruState, cs),
 381     DEFINE_PROP_UINT8("debug", PassthruState, debug, 0),
 382     DEFINE_PROP_END_OF_LIST(),
 383 };
 384
 385 static void passthru_class_initfn(ObjectClass *klass, void *data)
 386 {
 387     DeviceClass *dc = DEVICE_CLASS(klass);
 388     CCIDCardClass *cc = CCID_CARD_CLASS(klass);
 389
 390     cc->initfn = passthru_initfn;
 391     cc->get_atr = passthru_get_atr;
 392     cc->apdu_from_guest = passthru_apdu_from_guest;
 393     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 394     dc->desc = "passthrough smartcard";
 395     dc->vmsd = &passthru_vmstate;
 396     dc->props = passthru_card_properties;
 397 }
 398
 399 static const TypeInfo passthru_card_info = {
 400     .name          = TYPE_CCID_PASSTHRU,
 401     .parent        = TYPE_CCID_CARD,
 402     .instance_size = sizeof(PassthruState),
 403     .class_init    = passthru_class_initfn,
 404 };
 405
 406 static void ccid_card_passthru_register_types(void)
 407 {
 408     type_register_static(&passthru_card_info);
 409 }
 410
 411 type_init(ccid_card_passthru_register_types)