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 #if LIBCURL_VERSION_NUM >= 0x071000
  38 /* The multi interface timer callback was introduced in 7.16.0 */
  39 #define NEED_CURL_TIMER_CALLBACK
  40 #endif
  41
  42 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  43                    CURLPROTO_FTP | CURLPROTO_FTPS | \
  44                    CURLPROTO_TFTP)
  45
  46 #define CURL_NUM_STATES 8
  47 #define CURL_NUM_ACB    8
  48 #define SECTOR_SIZE     512
  49 #define READ_AHEAD_SIZE (256 * 1024)
  50
  51 #define FIND_RET_NONE   0
  52 #define FIND_RET_OK     1
  53 #define FIND_RET_WAIT   2
  54
  55 struct BDRVCURLState;
  56
  57 typedef struct CURLAIOCB {
  58     BlockDriverAIOCB common;
  59     QEMUBH *bh;
  60     QEMUIOVector *qiov;
  61
  62     int64_t sector_num;
  63     int nb_sectors;
  64
  65     size_t start;
  66     size_t end;
  67 } CURLAIOCB;
  68
  69 typedef struct CURLState
  70 {
  71     struct BDRVCURLState *s;
  72     CURLAIOCB *acb[CURL_NUM_ACB];
  73     CURL *curl;
  74     char *orig_buf;
  75     size_t buf_start;
  76     size_t buf_off;
  77     size_t buf_len;
  78     char range[128];
  79     char errmsg[CURL_ERROR_SIZE];
  80     char in_use;
  81 } CURLState;
  82
  83 typedef struct BDRVCURLState {
  84     CURLM *multi;
  85     QEMUTimer timer;
  86     size_t len;
  87     CURLState states[CURL_NUM_STATES];
  88     char *url;
  89     size_t readahead_size;
  90     bool accept_range;
  91 } BDRVCURLState;
  92
  93 static void curl_clean_state(CURLState *s);
  94 static void curl_multi_do(void *arg);
  95
  96 #ifdef NEED_CURL_TIMER_CALLBACK
  97 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
  98 {
  99     BDRVCURLState *s = opaque;
 100
 101     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
 102     if (timeout_ms == -1) {
 103         timer_del(&s->timer);
 104     } else {
 105         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 106         timer_mod(&s->timer,
 107                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 108     }
 109     return 0;
 110 }
 111 #endif
 112
 113 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 114                         void *s, void *sp)
 115 {
 116     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, fd);
 117     switch (action) {
 118         case CURL_POLL_IN:
 119             qemu_aio_set_fd_handler(fd, curl_multi_do, NULL, s);
 120             break;
 121         case CURL_POLL_OUT:
 122             qemu_aio_set_fd_handler(fd, NULL, curl_multi_do, s);
 123             break;
 124         case CURL_POLL_INOUT:
 125             qemu_aio_set_fd_handler(fd, curl_multi_do, curl_multi_do, s);
 126             break;
 127         case CURL_POLL_REMOVE:
 128             qemu_aio_set_fd_handler(fd, NULL, NULL, NULL);
 129             break;
 130     }
 131
 132     return 0;
 133 }
 134
 135 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 136 {
 137     BDRVCURLState *s = opaque;
 138     size_t realsize = size * nmemb;
 139     const char *accept_line = "Accept-Ranges: bytes";
 140
 141     if (realsize >= strlen(accept_line)
 142         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
 143         s->accept_range = true;
 144     }
 145
 146     return realsize;
 147 }
 148
 149 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 150 {
 151     CURLState *s = ((CURLState*)opaque);
 152     size_t realsize = size * nmemb;
 153     int i;
 154
 155     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
 156
 157     if (!s || !s->orig_buf)
 158         goto read_end;
 159
 160     if (s->buf_off >= s->buf_len) {
 161         /* buffer full, read nothing */
 162         return 0;
 163     }
 164     realsize = MIN(realsize, s->buf_len - s->buf_off);
 165     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 166     s->buf_off += realsize;
 167
 168     for(i=0; i<CURL_NUM_ACB; i++) {
 169         CURLAIOCB *acb = s->acb[i];
 170
 171         if (!acb)
 172             continue;
 173
 174         if ((s->buf_off >= acb->end)) {
 175             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
 176                                 acb->end - acb->start);
 177             acb->common.cb(acb->common.opaque, 0);
 178             qemu_aio_release(acb);
 179             s->acb[i] = NULL;
 180         }
 181     }
 182
 183 read_end:
 184     return realsize;
 185 }
 186
 187 static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len,
 188                          CURLAIOCB *acb)
 189 {
 190     int i;
 191     size_t end = start + len;
 192
 193     for (i=0; i<CURL_NUM_STATES; i++) {
 194         CURLState *state = &s->states[i];
 195         size_t buf_end = (state->buf_start + state->buf_off);
 196         size_t buf_fend = (state->buf_start + state->buf_len);
 197
 198         if (!state->orig_buf)
 199             continue;
 200         if (!state->buf_off)
 201             continue;
 202
 203         // Does the existing buffer cover our section?
 204         if ((start >= state->buf_start) &&
 205             (start <= buf_end) &&
 206             (end >= state->buf_start) &&
 207             (end <= buf_end))
 208         {
 209             char *buf = state->orig_buf + (start - state->buf_start);
 210
 211             qemu_iovec_from_buf(acb->qiov, 0, buf, len);
 212             acb->common.cb(acb->common.opaque, 0);
 213
 214             return FIND_RET_OK;
 215         }
 216
 217         // Wait for unfinished chunks
 218         if ((start >= state->buf_start) &&
 219             (start <= buf_fend) &&
 220             (end >= state->buf_start) &&
 221             (end <= buf_fend))
 222         {
 223             int j;
 224
 225             acb->start = start - state->buf_start;
 226             acb->end = acb->start + len;
 227
 228             for (j=0; j<CURL_NUM_ACB; j++) {
 229                 if (!state->acb[j]) {
 230                     state->acb[j] = acb;
 231                     return FIND_RET_WAIT;
 232                 }
 233             }
 234         }
 235     }
 236
 237     return FIND_RET_NONE;
 238 }
 239
 240 static void curl_multi_read(BDRVCURLState *s)
 241 {
 242     int msgs_in_queue;
 243
 244     /* Try to find done transfers, so we can free the easy
 245      * handle again. */
 246     do {
 247         CURLMsg *msg;
 248         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 249
 250         if (!msg)
 251             break;
 252         if (msg->msg == CURLMSG_NONE)
 253             break;
 254
 255         switch (msg->msg) {
 256             case CURLMSG_DONE:
 257             {
 258                 CURLState *state = NULL;
 259                 curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE, (char**)&state);
 260
 261                 /* ACBs for successful messages get completed in curl_read_cb */
 262                 if (msg->data.result != CURLE_OK) {
 263                     int i;
 264                     for (i = 0; i < CURL_NUM_ACB; i++) {
 265                         CURLAIOCB *acb = state->acb[i];
 266
 267                         if (acb == NULL) {
 268                             continue;
 269                         }
 270
 271                         acb->common.cb(acb->common.opaque, -EIO);
 272                         qemu_aio_release(acb);
 273                         state->acb[i] = NULL;
 274                     }
 275                 }
 276
 277                 curl_clean_state(state);
 278                 break;
 279             }
 280             default:
 281                 msgs_in_queue = 0;
 282                 break;
 283         }
 284     } while(msgs_in_queue);
 285 }
 286
 287 static void curl_multi_do(void *arg)
 288 {
 289     BDRVCURLState *s = (BDRVCURLState *)arg;
 290     int running;
 291     int r;
 292
 293     if (!s->multi) {
 294         return;
 295     }
 296
 297     do {
 298         r = curl_multi_socket_all(s->multi, &running);
 299     } while(r == CURLM_CALL_MULTI_PERFORM);
 300
 301     curl_multi_read(s);
 302 }
 303
 304 static void curl_multi_timeout_do(void *arg)
 305 {
 306 #ifdef NEED_CURL_TIMER_CALLBACK
 307     BDRVCURLState *s = (BDRVCURLState *)arg;
 308     int running;
 309
 310     if (!s->multi) {
 311         return;
 312     }
 313
 314     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 315
 316     curl_multi_read(s);
 317 #else
 318     abort();
 319 #endif
 320 }
 321
 322 static CURLState *curl_init_state(BDRVCURLState *s)
 323 {
 324     CURLState *state = NULL;
 325     int i, j;
 326
 327     do {
 328         for (i=0; i<CURL_NUM_STATES; i++) {
 329             for (j=0; j<CURL_NUM_ACB; j++)
 330                 if (s->states[i].acb[j])
 331                     continue;
 332             if (s->states[i].in_use)
 333                 continue;
 334
 335             state = &s->states[i];
 336             state->in_use = 1;
 337             break;
 338         }
 339         if (!state) {
 340             g_usleep(100);
 341             curl_multi_do(s);
 342         }
 343     } while(!state);
 344
 345     if (state->curl)
 346         goto has_curl;
 347
 348     state->curl = curl_easy_init();
 349     if (!state->curl)
 350         return NULL;
 351     curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 352     curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, 5);
 353     curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, (void *)curl_read_cb);
 354     curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 355     curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 356     curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 357     curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 358     curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 359     curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 360     curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 361
 362     /* Restrict supported protocols to avoid security issues in the more
 363      * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 364      * CVE-2013-0249.
 365      *
 366      * Restricting protocols is only supported from 7.19.4 upwards.
 367      */
 368 #if LIBCURL_VERSION_NUM >= 0x071304
 369     curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 370     curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 371 #endif
 372
 373 #ifdef DEBUG_VERBOSE
 374     curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 375 #endif
 376
 377 has_curl:
 378
 379     state->s = s;
 380
 381     return state;
 382 }
 383
 384 static void curl_clean_state(CURLState *s)
 385 {
 386     if (s->s->multi)
 387         curl_multi_remove_handle(s->s->multi, s->curl);
 388     s->in_use = 0;
 389 }
 390
 391 static void curl_parse_filename(const char *filename, QDict *options,
 392                                 Error **errp)
 393 {
 394
 395     #define RA_OPTSTR ":readahead="
 396     char *file;
 397     char *ra;
 398     const char *ra_val;
 399     int parse_state = 0;
 400
 401     file = g_strdup(filename);
 402
 403     /* Parse a trailing ":readahead=#:" param, if present. */
 404     ra = file + strlen(file) - 1;
 405     while (ra >= file) {
 406         if (parse_state == 0) {
 407             if (*ra == ':') {
 408                 parse_state++;
 409             } else {
 410                 break;
 411             }
 412         } else if (parse_state == 1) {
 413             if (*ra > '9' || *ra < '0') {
 414                 char *opt_start = ra - strlen(RA_OPTSTR) + 1;
 415                 if (opt_start > file &&
 416                     strncmp(opt_start, RA_OPTSTR, strlen(RA_OPTSTR)) == 0) {
 417                     ra_val = ra + 1;
 418                     ra -= strlen(RA_OPTSTR) - 1;
 419                     *ra = '\0';
 420                     qdict_put(options, "readahead", qstring_from_str(ra_val));
 421                 }
 422                 break;
 423             }
 424         }
 425         ra--;
 426     }
 427
 428     qdict_put(options, "url", qstring_from_str(file));
 429
 430     g_free(file);
 431 }
 432
 433 static QemuOptsList runtime_opts = {
 434     .name = "curl",
 435     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 436     .desc = {
 437         {
 438             .name = "url",
 439             .type = QEMU_OPT_STRING,
 440             .help = "URL to open",
 441         },
 442         {
 443             .name = "readahead",
 444             .type = QEMU_OPT_SIZE,
 445             .help = "Readahead size",
 446         },
 447         { /* end of list */ }
 448     },
 449 };
 450
 451 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 452                      Error **errp)
 453 {
 454     BDRVCURLState *s = bs->opaque;
 455     CURLState *state = NULL;
 456     QemuOpts *opts;
 457     Error *local_err = NULL;
 458     const char *file;
 459     double d;
 460
 461     static int inited = 0;
 462
 463     if (flags & BDRV_O_RDWR) {
 464         error_setg(errp, "curl block device does not support writes");
 465         return -EROFS;
 466     }
 467
 468     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 469     qemu_opts_absorb_qdict(opts, options, &local_err);
 470     if (local_err) {
 471         error_propagate(errp, local_err);
 472         goto out_noclean;
 473     }
 474
 475     s->readahead_size = qemu_opt_get_size(opts, "readahead", READ_AHEAD_SIZE);
 476     if ((s->readahead_size & 0x1ff) != 0) {
 477         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 478                    s->readahead_size);
 479         goto out_noclean;
 480     }
 481
 482     file = qemu_opt_get(opts, "url");
 483     if (file == NULL) {
 484         error_setg(errp, "curl block driver requires an 'url' option");
 485         goto out_noclean;
 486     }
 487
 488     if (!inited) {
 489         curl_global_init(CURL_GLOBAL_ALL);
 490         inited = 1;
 491     }
 492
 493     DPRINTF("CURL: Opening %s\n", file);
 494     s->url = g_strdup(file);
 495     state = curl_init_state(s);
 496     if (!state)
 497         goto out_noclean;
 498
 499     // Get file size
 500
 501     s->accept_range = false;
 502     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 503     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 504                      curl_header_cb);
 505     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 506     if (curl_easy_perform(state->curl))
 507         goto out;
 508     curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d);
 509     if (d)
 510         s->len = (size_t)d;
 511     else if(!s->len)
 512         goto out;
 513     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 514         || !strncasecmp(s->url, "https://", strlen("https://")))
 515         && !s->accept_range) {
 516         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 517                 "Server does not support 'range' (byte ranges).");
 518         goto out;
 519     }
 520     DPRINTF("CURL: Size = %zd\n", s->len);
 521
 522     curl_clean_state(state);
 523     curl_easy_cleanup(state->curl);
 524     state->curl = NULL;
 525
 526     aio_timer_init(bdrv_get_aio_context(bs), &s->timer,
 527                    QEMU_CLOCK_REALTIME, SCALE_NS,
 528                    curl_multi_timeout_do, s);
 529
 530     // Now we know the file exists and its size, so let's
 531     // initialize the multi interface!
 532
 533     s->multi = curl_multi_init();
 534     curl_multi_setopt(s->multi, CURLMOPT_SOCKETDATA, s);
 535     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 536 #ifdef NEED_CURL_TIMER_CALLBACK
 537     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 538     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 539 #endif
 540     curl_multi_do(s);
 541
 542     qemu_opts_del(opts);
 543     return 0;
 544
 545 out:
 546     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 547     curl_easy_cleanup(state->curl);
 548     state->curl = NULL;
 549 out_noclean:
 550     g_free(s->url);
 551     qemu_opts_del(opts);
 552     return -EINVAL;
 553 }
 554
 555 static void curl_aio_cancel(BlockDriverAIOCB *blockacb)
 556 {
 557     // Do we have to implement canceling? Seems to work without...
 558 }
 559
 560 static const AIOCBInfo curl_aiocb_info = {
 561     .aiocb_size         = sizeof(CURLAIOCB),
 562     .cancel             = curl_aio_cancel,
 563 };
 564
 565
 566 static void curl_readv_bh_cb(void *p)
 567 {
 568     CURLState *state;
 569
 570     CURLAIOCB *acb = p;
 571     BDRVCURLState *s = acb->common.bs->opaque;
 572
 573     qemu_bh_delete(acb->bh);
 574     acb->bh = NULL;
 575
 576     size_t start = acb->sector_num * SECTOR_SIZE;
 577     size_t end;
 578
 579     // In case we have the requested data already (e.g. read-ahead),
 580     // we can just call the callback and be done.
 581     switch (curl_find_buf(s, start, acb->nb_sectors * SECTOR_SIZE, acb)) {
 582         case FIND_RET_OK:
 583             qemu_aio_release(acb);
 584             // fall through
 585         case FIND_RET_WAIT:
 586             return;
 587         default:
 588             break;
 589     }
 590
 591     // No cache found, so let's start a new request
 592     state = curl_init_state(s);
 593     if (!state) {
 594         acb->common.cb(acb->common.opaque, -EIO);
 595         qemu_aio_release(acb);
 596         return;
 597     }
 598
 599     acb->start = 0;
 600     acb->end = (acb->nb_sectors * SECTOR_SIZE);
 601
 602     state->buf_off = 0;
 603     if (state->orig_buf)
 604         g_free(state->orig_buf);
 605     state->buf_start = start;
 606     state->buf_len = acb->end + s->readahead_size;
 607     end = MIN(start + state->buf_len, s->len) - 1;
 608     state->orig_buf = g_malloc(state->buf_len);
 609     state->acb[0] = acb;
 610
 611     snprintf(state->range, 127, "%zd-%zd", start, end);
 612     DPRINTF("CURL (AIO): Reading %d at %zd (%s)\n",
 613             (acb->nb_sectors * SECTOR_SIZE), start, state->range);
 614     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 615
 616     curl_multi_add_handle(s->multi, state->curl);
 617     curl_multi_do(s);
 618
 619 }
 620
 621 static BlockDriverAIOCB *curl_aio_readv(BlockDriverState *bs,
 622         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 623         BlockDriverCompletionFunc *cb, void *opaque)
 624 {
 625     CURLAIOCB *acb;
 626
 627     acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque);
 628
 629     acb->qiov = qiov;
 630     acb->sector_num = sector_num;
 631     acb->nb_sectors = nb_sectors;
 632
 633     acb->bh = qemu_bh_new(curl_readv_bh_cb, acb);
 634     qemu_bh_schedule(acb->bh);
 635     return &acb->common;
 636 }
 637
 638 static void curl_close(BlockDriverState *bs)
 639 {
 640     BDRVCURLState *s = bs->opaque;
 641     int i;
 642
 643     DPRINTF("CURL: Close\n");
 644     for (i=0; i<CURL_NUM_STATES; i++) {
 645         if (s->states[i].in_use)
 646             curl_clean_state(&s->states[i]);
 647         if (s->states[i].curl) {
 648             curl_easy_cleanup(s->states[i].curl);
 649             s->states[i].curl = NULL;
 650         }
 651         if (s->states[i].orig_buf) {
 652             g_free(s->states[i].orig_buf);
 653             s->states[i].orig_buf = NULL;
 654         }
 655     }
 656     if (s->multi)
 657         curl_multi_cleanup(s->multi);
 658
 659     timer_del(&s->timer);
 660
 661     g_free(s->url);
 662 }
 663
 664 static int64_t curl_getlength(BlockDriverState *bs)
 665 {
 666     BDRVCURLState *s = bs->opaque;
 667     return s->len;
 668 }
 669
 670 static BlockDriver bdrv_http = {
 671     .format_name            = "http",
 672     .protocol_name          = "http",
 673
 674     .instance_size          = sizeof(BDRVCURLState),
 675     .bdrv_parse_filename    = curl_parse_filename,
 676     .bdrv_file_open         = curl_open,
 677     .bdrv_close             = curl_close,
 678     .bdrv_getlength         = curl_getlength,
 679
 680     .bdrv_aio_readv         = curl_aio_readv,
 681 };
 682
 683 static BlockDriver bdrv_https = {
 684     .format_name            = "https",
 685     .protocol_name          = "https",
 686
 687     .instance_size          = sizeof(BDRVCURLState),
 688     .bdrv_parse_filename    = curl_parse_filename,
 689     .bdrv_file_open         = curl_open,
 690     .bdrv_close             = curl_close,
 691     .bdrv_getlength         = curl_getlength,
 692
 693     .bdrv_aio_readv         = curl_aio_readv,
 694 };
 695
 696 static BlockDriver bdrv_ftp = {
 697     .format_name            = "ftp",
 698     .protocol_name          = "ftp",
 699
 700     .instance_size          = sizeof(BDRVCURLState),
 701     .bdrv_parse_filename    = curl_parse_filename,
 702     .bdrv_file_open         = curl_open,
 703     .bdrv_close             = curl_close,
 704     .bdrv_getlength         = curl_getlength,
 705
 706     .bdrv_aio_readv         = curl_aio_readv,
 707 };
 708
 709 static BlockDriver bdrv_ftps = {
 710     .format_name            = "ftps",
 711     .protocol_name          = "ftps",
 712
 713     .instance_size          = sizeof(BDRVCURLState),
 714     .bdrv_parse_filename    = curl_parse_filename,
 715     .bdrv_file_open         = curl_open,
 716     .bdrv_close             = curl_close,
 717     .bdrv_getlength         = curl_getlength,
 718
 719     .bdrv_aio_readv         = curl_aio_readv,
 720 };
 721
 722 static BlockDriver bdrv_tftp = {
 723     .format_name            = "tftp",
 724     .protocol_name          = "tftp",
 725
 726     .instance_size          = sizeof(BDRVCURLState),
 727     .bdrv_parse_filename    = curl_parse_filename,
 728     .bdrv_file_open         = curl_open,
 729     .bdrv_close             = curl_close,
 730     .bdrv_getlength         = curl_getlength,
 731
 732     .bdrv_aio_readv         = curl_aio_readv,
 733 };
 734
 735 static void curl_block_init(void)
 736 {
 737     bdrv_register(&bdrv_http);
 738     bdrv_register(&bdrv_https);
 739     bdrv_register(&bdrv_ftp);
 740     bdrv_register(&bdrv_ftps);
 741     bdrv_register(&bdrv_tftp);
 742 }
 743
 744 block_init(curl_block_init);