block/curl.c

   1 /*
   2  * QEMU Block driver for CURL images
   3  *
   4  * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "qemu-common.h"
  25 #include "block/block_int.h"
  26 #include <curl/curl.h>
  27
  28 // #define DEBUG
  29 // #define DEBUG_VERBOSE
  30
  31 #ifdef DEBUG_CURL
  32 #define DPRINTF(fmt, ...) do { printf(fmt, ## __VA_ARGS__); } while (0)
  33 #else
  34 #define DPRINTF(fmt, ...) do { } while (0)
  35 #endif
  36
  37 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  38                    CURLPROTO_FTP | CURLPROTO_FTPS | \
  39                    CURLPROTO_TFTP)
  40
  41 #define CURL_NUM_STATES 8
  42 #define CURL_NUM_ACB    8
  43 #define SECTOR_SIZE     512
  44 #define READ_AHEAD_SIZE (256 * 1024)
  45
  46 #define FIND_RET_NONE   0
  47 #define FIND_RET_OK     1
  48 #define FIND_RET_WAIT   2
  49
  50 struct BDRVCURLState;
  51
  52 typedef struct CURLAIOCB {
  53     BlockDriverAIOCB common;
  54     QEMUBH *bh;
  55     QEMUIOVector *qiov;
  56
  57     int64_t sector_num;
  58     int nb_sectors;
  59
  60     size_t start;
  61     size_t end;
  62 } CURLAIOCB;
  63
  64 typedef struct CURLState
  65 {
  66     struct BDRVCURLState *s;
  67     CURLAIOCB *acb[CURL_NUM_ACB];
  68     CURL *curl;
  69     char *orig_buf;
  70     size_t buf_start;
  71     size_t buf_off;
  72     size_t buf_len;
  73     char range[128];
  74     char errmsg[CURL_ERROR_SIZE];
  75     char in_use;
  76 } CURLState;
  77
  78 typedef struct BDRVCURLState {
  79     CURLM *multi;
  80     size_t len;
  81     CURLState states[CURL_NUM_STATES];
  82     char *url;
  83     size_t readahead_size;
  84 } BDRVCURLState;
  85
  86 static void curl_clean_state(CURLState *s);
  87 static void curl_multi_do(void *arg);
  88 static int curl_aio_flush(void *opaque);
  89
  90 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
  91                         void *s, void *sp)
  92 {
  93     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, fd);
  94     switch (action) {
  95         case CURL_POLL_IN:
  96             qemu_aio_set_fd_handler(fd, curl_multi_do, NULL, curl_aio_flush, s);
  97             break;
  98         case CURL_POLL_OUT:
  99             qemu_aio_set_fd_handler(fd, NULL, curl_multi_do, curl_aio_flush, s);
 100             break;
 101         case CURL_POLL_INOUT:
 102             qemu_aio_set_fd_handler(fd, curl_multi_do, curl_multi_do,
 103                                     curl_aio_flush, s);
 104             break;
 105         case CURL_POLL_REMOVE:
 106             qemu_aio_set_fd_handler(fd, NULL, NULL, NULL, NULL);
 107             break;
 108     }
 109
 110     return 0;
 111 }
 112
 113 static size_t curl_size_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 114 {
 115     CURLState *s = ((CURLState*)opaque);
 116     size_t realsize = size * nmemb;
 117     size_t fsize;
 118
 119     if(sscanf(ptr, "Content-Length: %zd", &fsize) == 1) {
 120         s->s->len = fsize;
 121     }
 122
 123     return realsize;
 124 }
 125
 126 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 127 {
 128     CURLState *s = ((CURLState*)opaque);
 129     size_t realsize = size * nmemb;
 130     int i;
 131
 132     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
 133
 134     if (!s || !s->orig_buf)
 135         goto read_end;
 136
 137     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 138     s->buf_off += realsize;
 139
 140     for(i=0; i<CURL_NUM_ACB; i++) {
 141         CURLAIOCB *acb = s->acb[i];
 142
 143         if (!acb)
 144             continue;
 145
 146         if ((s->buf_off >= acb->end)) {
 147             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
 148                                 acb->end - acb->start);
 149             acb->common.cb(acb->common.opaque, 0);
 150             qemu_aio_release(acb);
 151             s->acb[i] = NULL;
 152         }
 153     }
 154
 155 read_end:
 156     return realsize;
 157 }
 158
 159 static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len,
 160                          CURLAIOCB *acb)
 161 {
 162     int i;
 163     size_t end = start + len;
 164
 165     for (i=0; i<CURL_NUM_STATES; i++) {
 166         CURLState *state = &s->states[i];
 167         size_t buf_end = (state->buf_start + state->buf_off);
 168         size_t buf_fend = (state->buf_start + state->buf_len);
 169
 170         if (!state->orig_buf)
 171             continue;
 172         if (!state->buf_off)
 173             continue;
 174
 175         // Does the existing buffer cover our section?
 176         if ((start >= state->buf_start) &&
 177             (start <= buf_end) &&
 178             (end >= state->buf_start) &&
 179             (end <= buf_end))
 180         {
 181             char *buf = state->orig_buf + (start - state->buf_start);
 182
 183             qemu_iovec_from_buf(acb->qiov, 0, buf, len);
 184             acb->common.cb(acb->common.opaque, 0);
 185
 186             return FIND_RET_OK;
 187         }
 188
 189         // Wait for unfinished chunks
 190         if ((start >= state->buf_start) &&
 191             (start <= buf_fend) &&
 192             (end >= state->buf_start) &&
 193             (end <= buf_fend))
 194         {
 195             int j;
 196
 197             acb->start = start - state->buf_start;
 198             acb->end = acb->start + len;
 199
 200             for (j=0; j<CURL_NUM_ACB; j++) {
 201                 if (!state->acb[j]) {
 202                     state->acb[j] = acb;
 203                     return FIND_RET_WAIT;
 204                 }
 205             }
 206         }
 207     }
 208
 209     return FIND_RET_NONE;
 210 }
 211
 212 static void curl_multi_do(void *arg)
 213 {
 214     BDRVCURLState *s = (BDRVCURLState *)arg;
 215     int running;
 216     int r;
 217     int msgs_in_queue;
 218
 219     if (!s->multi)
 220         return;
 221
 222     do {
 223         r = curl_multi_socket_all(s->multi, &running);
 224     } while(r == CURLM_CALL_MULTI_PERFORM);
 225
 226     /* Try to find done transfers, so we can free the easy
 227      * handle again. */
 228     do {
 229         CURLMsg *msg;
 230         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 231
 232         if (!msg)
 233             break;
 234         if (msg->msg == CURLMSG_NONE)
 235             break;
 236
 237         switch (msg->msg) {
 238             case CURLMSG_DONE:
 239             {
 240                 CURLState *state = NULL;
 241                 curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE, (char**)&state);
 242
 243                 /* ACBs for successful messages get completed in curl_read_cb */
 244                 if (msg->data.result != CURLE_OK) {
 245                     int i;
 246                     for (i = 0; i < CURL_NUM_ACB; i++) {
 247                         CURLAIOCB *acb = state->acb[i];
 248
 249                         if (acb == NULL) {
 250                             continue;
 251                         }
 252
 253                         acb->common.cb(acb->common.opaque, -EIO);
 254                         qemu_aio_release(acb);
 255                         state->acb[i] = NULL;
 256                     }
 257                 }
 258
 259                 curl_clean_state(state);
 260                 break;
 261             }
 262             default:
 263                 msgs_in_queue = 0;
 264                 break;
 265         }
 266     } while(msgs_in_queue);
 267 }
 268
 269 static CURLState *curl_init_state(BDRVCURLState *s)
 270 {
 271     CURLState *state = NULL;
 272     int i, j;
 273
 274     do {
 275         for (i=0; i<CURL_NUM_STATES; i++) {
 276             for (j=0; j<CURL_NUM_ACB; j++)
 277                 if (s->states[i].acb[j])
 278                     continue;
 279             if (s->states[i].in_use)
 280                 continue;
 281
 282             state = &s->states[i];
 283             state->in_use = 1;
 284             break;
 285         }
 286         if (!state) {
 287             g_usleep(100);
 288             curl_multi_do(s);
 289         }
 290     } while(!state);
 291
 292     if (state->curl)
 293         goto has_curl;
 294
 295     state->curl = curl_easy_init();
 296     if (!state->curl)
 297         return NULL;
 298     curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 299     curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, 5);
 300     curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, (void *)curl_read_cb);
 301     curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 302     curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 303     curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 304     curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 305     curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 306     curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 307     curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 308
 309     /* Restrict supported protocols to avoid security issues in the more
 310      * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 311      * CVE-2013-0249.
 312      *
 313      * Restricting protocols is only supported from 7.19.4 upwards.
 314      */
 315 #if LIBCURL_VERSION_NUM >= 0x071304
 316     curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 317     curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 318 #endif
 319
 320 #ifdef DEBUG_VERBOSE
 321     curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 322 #endif
 323
 324 has_curl:
 325
 326     state->s = s;
 327
 328     return state;
 329 }
 330
 331 static void curl_clean_state(CURLState *s)
 332 {
 333     if (s->s->multi)
 334         curl_multi_remove_handle(s->s->multi, s->curl);
 335     s->in_use = 0;
 336 }
 337
 338 static void curl_parse_filename(const char *filename, QDict *options,
 339                                 Error **errp)
 340 {
 341
 342     #define RA_OPTSTR ":readahead="
 343     char *file;
 344     char *ra;
 345     const char *ra_val;
 346     int parse_state = 0;
 347
 348     file = g_strdup(filename);
 349
 350     /* Parse a trailing ":readahead=#:" param, if present. */
 351     ra = file + strlen(file) - 1;
 352     while (ra >= file) {
 353         if (parse_state == 0) {
 354             if (*ra == ':') {
 355                 parse_state++;
 356             } else {
 357                 break;
 358             }
 359         } else if (parse_state == 1) {
 360             if (*ra > '9' || *ra < '0') {
 361                 char *opt_start = ra - strlen(RA_OPTSTR) + 1;
 362                 if (opt_start > file &&
 363                     strncmp(opt_start, RA_OPTSTR, strlen(RA_OPTSTR)) == 0) {
 364                     ra_val = ra + 1;
 365                     ra -= strlen(RA_OPTSTR) - 1;
 366                     *ra = '\0';
 367                     qdict_put(options, "readahead", qstring_from_str(ra_val));
 368                 }
 369                 break;
 370             }
 371         }
 372         ra--;
 373     }
 374
 375     qdict_put(options, "url", qstring_from_str(file));
 376
 377     g_free(file);
 378 }
 379
 380 static QemuOptsList runtime_opts = {
 381     .name = "curl",
 382     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 383     .desc = {
 384         {
 385             .name = "url",
 386             .type = QEMU_OPT_STRING,
 387             .help = "URL to open",
 388         },
 389         {
 390             .name = "readahead",
 391             .type = QEMU_OPT_SIZE,
 392             .help = "Readahead size",
 393         },
 394         { /* end of list */ }
 395     },
 396 };
 397
 398 static int curl_open(BlockDriverState *bs, QDict *options, int flags)
 399 {
 400     BDRVCURLState *s = bs->opaque;
 401     CURLState *state = NULL;
 402     QemuOpts *opts;
 403     Error *local_err = NULL;
 404     const char *file;
 405     double d;
 406
 407     static int inited = 0;
 408
 409     if (flags & BDRV_O_RDWR) {
 410         qerror_report(ERROR_CLASS_GENERIC_ERROR,
 411                       "curl block device does not support writes");
 412         return -EROFS;
 413     }
 414
 415     opts = qemu_opts_create_nofail(&runtime_opts);
 416     qemu_opts_absorb_qdict(opts, options, &local_err);
 417     if (error_is_set(&local_err)) {
 418         qerror_report_err(local_err);
 419         error_free(local_err);
 420         goto out_noclean;
 421     }
 422
 423     s->readahead_size = qemu_opt_get_size(opts, "readahead", READ_AHEAD_SIZE);
 424     if ((s->readahead_size & 0x1ff) != 0) {
 425         fprintf(stderr, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512\n",
 426                 s->readahead_size);
 427         goto out_noclean;
 428     }
 429
 430     file = qemu_opt_get(opts, "url");
 431     if (file == NULL) {
 432         qerror_report(ERROR_CLASS_GENERIC_ERROR, "curl block driver requires "
 433                       "an 'url' option");
 434         goto out_noclean;
 435     }
 436
 437     if (!inited) {
 438         curl_global_init(CURL_GLOBAL_ALL);
 439         inited = 1;
 440     }
 441
 442     DPRINTF("CURL: Opening %s\n", file);
 443     s->url = g_strdup(file);
 444     state = curl_init_state(s);
 445     if (!state)
 446         goto out_noclean;
 447
 448     // Get file size
 449
 450     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 451     curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, (void *)curl_size_cb);
 452     if (curl_easy_perform(state->curl))
 453         goto out;
 454     curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d);
 455     if (d)
 456         s->len = (size_t)d;
 457     else if(!s->len)
 458         goto out;
 459     DPRINTF("CURL: Size = %zd\n", s->len);
 460
 461     curl_clean_state(state);
 462     curl_easy_cleanup(state->curl);
 463     state->curl = NULL;
 464
 465     // Now we know the file exists and its size, so let's
 466     // initialize the multi interface!
 467
 468     s->multi = curl_multi_init();
 469     curl_multi_setopt(s->multi, CURLMOPT_SOCKETDATA, s);
 470     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 471     curl_multi_do(s);
 472
 473     qemu_opts_del(opts);
 474     return 0;
 475
 476 out:
 477     fprintf(stderr, "CURL: Error opening file: %s\n", state->errmsg);
 478     curl_easy_cleanup(state->curl);
 479     state->curl = NULL;
 480 out_noclean:
 481     g_free(s->url);
 482     qemu_opts_del(opts);
 483     return -EINVAL;
 484 }
 485
 486 static int curl_aio_flush(void *opaque)
 487 {
 488     BDRVCURLState *s = opaque;
 489     int i, j;
 490
 491     for (i=0; i < CURL_NUM_STATES; i++) {
 492         for(j=0; j < CURL_NUM_ACB; j++) {
 493             if (s->states[i].acb[j]) {
 494                 return 1;
 495             }
 496         }
 497     }
 498     return 0;
 499 }
 500
 501 static void curl_aio_cancel(BlockDriverAIOCB *blockacb)
 502 {
 503     // Do we have to implement canceling? Seems to work without...
 504 }
 505
 506 static const AIOCBInfo curl_aiocb_info = {
 507     .aiocb_size         = sizeof(CURLAIOCB),
 508     .cancel             = curl_aio_cancel,
 509 };
 510
 511
 512 static void curl_readv_bh_cb(void *p)
 513 {
 514     CURLState *state;
 515
 516     CURLAIOCB *acb = p;
 517     BDRVCURLState *s = acb->common.bs->opaque;
 518
 519     qemu_bh_delete(acb->bh);
 520     acb->bh = NULL;
 521
 522     size_t start = acb->sector_num * SECTOR_SIZE;
 523     size_t end;
 524
 525     // In case we have the requested data already (e.g. read-ahead),
 526     // we can just call the callback and be done.
 527     switch (curl_find_buf(s, start, acb->nb_sectors * SECTOR_SIZE, acb)) {
 528         case FIND_RET_OK:
 529             qemu_aio_release(acb);
 530             // fall through
 531         case FIND_RET_WAIT:
 532             return;
 533         default:
 534             break;
 535     }
 536
 537     // No cache found, so let's start a new request
 538     state = curl_init_state(s);
 539     if (!state) {
 540         acb->common.cb(acb->common.opaque, -EIO);
 541         qemu_aio_release(acb);
 542         return;
 543     }
 544
 545     acb->start = 0;
 546     acb->end = (acb->nb_sectors * SECTOR_SIZE);
 547
 548     state->buf_off = 0;
 549     if (state->orig_buf)
 550         g_free(state->orig_buf);
 551     state->buf_start = start;
 552     state->buf_len = acb->end + s->readahead_size;
 553     end = MIN(start + state->buf_len, s->len) - 1;
 554     state->orig_buf = g_malloc(state->buf_len);
 555     state->acb[0] = acb;
 556
 557     snprintf(state->range, 127, "%zd-%zd", start, end);
 558     DPRINTF("CURL (AIO): Reading %d at %zd (%s)\n",
 559             (acb->nb_sectors * SECTOR_SIZE), start, state->range);
 560     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 561
 562     curl_multi_add_handle(s->multi, state->curl);
 563     curl_multi_do(s);
 564
 565 }
 566
 567 static BlockDriverAIOCB *curl_aio_readv(BlockDriverState *bs,
 568         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 569         BlockDriverCompletionFunc *cb, void *opaque)
 570 {
 571     CURLAIOCB *acb;
 572
 573     acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque);
 574
 575     acb->qiov = qiov;
 576     acb->sector_num = sector_num;
 577     acb->nb_sectors = nb_sectors;
 578
 579     acb->bh = qemu_bh_new(curl_readv_bh_cb, acb);
 580
 581     if (!acb->bh) {
 582         DPRINTF("CURL: qemu_bh_new failed\n");
 583         return NULL;
 584     }
 585
 586     qemu_bh_schedule(acb->bh);
 587     return &acb->common;
 588 }
 589
 590 static void curl_close(BlockDriverState *bs)
 591 {
 592     BDRVCURLState *s = bs->opaque;
 593     int i;
 594
 595     DPRINTF("CURL: Close\n");
 596     for (i=0; i<CURL_NUM_STATES; i++) {
 597         if (s->states[i].in_use)
 598             curl_clean_state(&s->states[i]);
 599         if (s->states[i].curl) {
 600             curl_easy_cleanup(s->states[i].curl);
 601             s->states[i].curl = NULL;
 602         }
 603         if (s->states[i].orig_buf) {
 604             g_free(s->states[i].orig_buf);
 605             s->states[i].orig_buf = NULL;
 606         }
 607     }
 608     if (s->multi)
 609         curl_multi_cleanup(s->multi);
 610     g_free(s->url);
 611 }
 612
 613 static int64_t curl_getlength(BlockDriverState *bs)
 614 {
 615     BDRVCURLState *s = bs->opaque;
 616     return s->len;
 617 }
 618
 619 static BlockDriver bdrv_http = {
 620     .format_name            = "http",
 621     .protocol_name          = "http",
 622
 623     .instance_size          = sizeof(BDRVCURLState),
 624     .bdrv_parse_filename    = curl_parse_filename,
 625     .bdrv_file_open         = curl_open,
 626     .bdrv_close             = curl_close,
 627     .bdrv_getlength         = curl_getlength,
 628
 629     .bdrv_aio_readv         = curl_aio_readv,
 630 };
 631
 632 static BlockDriver bdrv_https = {
 633     .format_name            = "https",
 634     .protocol_name          = "https",
 635
 636     .instance_size          = sizeof(BDRVCURLState),
 637     .bdrv_parse_filename    = curl_parse_filename,
 638     .bdrv_file_open         = curl_open,
 639     .bdrv_close             = curl_close,
 640     .bdrv_getlength         = curl_getlength,
 641
 642     .bdrv_aio_readv         = curl_aio_readv,
 643 };
 644
 645 static BlockDriver bdrv_ftp = {
 646     .format_name            = "ftp",
 647     .protocol_name          = "ftp",
 648
 649     .instance_size          = sizeof(BDRVCURLState),
 650     .bdrv_parse_filename    = curl_parse_filename,
 651     .bdrv_file_open         = curl_open,
 652     .bdrv_close             = curl_close,
 653     .bdrv_getlength         = curl_getlength,
 654
 655     .bdrv_aio_readv         = curl_aio_readv,
 656 };
 657
 658 static BlockDriver bdrv_ftps = {
 659     .format_name            = "ftps",
 660     .protocol_name          = "ftps",
 661
 662     .instance_size          = sizeof(BDRVCURLState),
 663     .bdrv_parse_filename    = curl_parse_filename,
 664     .bdrv_file_open         = curl_open,
 665     .bdrv_close             = curl_close,
 666     .bdrv_getlength         = curl_getlength,
 667
 668     .bdrv_aio_readv         = curl_aio_readv,
 669 };
 670
 671 static BlockDriver bdrv_tftp = {
 672     .format_name            = "tftp",
 673     .protocol_name          = "tftp",
 674
 675     .instance_size          = sizeof(BDRVCURLState),
 676     .bdrv_parse_filename    = curl_parse_filename,
 677     .bdrv_file_open         = curl_open,
 678     .bdrv_close             = curl_close,
 679     .bdrv_getlength         = curl_getlength,
 680
 681     .bdrv_aio_readv         = curl_aio_readv,
 682 };
 683
 684 static void curl_block_init(void)
 685 {
 686     bdrv_register(&bdrv_http);
 687     bdrv_register(&bdrv_https);
 688     bdrv_register(&bdrv_ftp);
 689     bdrv_register(&bdrv_ftps);
 690     bdrv_register(&bdrv_tftp);
 691 }
 692
 693 block_init(curl_block_init);