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 "qapi/qmp/qbool.h"
  27 #include <curl/curl.h>
  28
  29 // #define DEBUG
  30 // #define DEBUG_VERBOSE
  31
  32 #ifdef DEBUG_CURL
  33 #define DPRINTF(fmt, ...) do { printf(fmt, ## __VA_ARGS__); } while (0)
  34 #else
  35 #define DPRINTF(fmt, ...) do { } while (0)
  36 #endif
  37
  38 #if LIBCURL_VERSION_NUM >= 0x071000
  39 /* The multi interface timer callback was introduced in 7.16.0 */
  40 #define NEED_CURL_TIMER_CALLBACK
  41 #define HAVE_SOCKET_ACTION
  42 #endif
  43
  44 #ifndef HAVE_SOCKET_ACTION
  45 /* If curl_multi_socket_action isn't available, define it statically here in
  46  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
  47  * less efficient but still safe. */
  48 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
  49                                             curl_socket_t sockfd,
  50                                             int ev_bitmask,
  51                                             int *running_handles)
  52 {
  53     return curl_multi_socket(multi_handle, sockfd, running_handles);
  54 }
  55 #define curl_multi_socket_action __curl_multi_socket_action
  56 #endif
  57
  58 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  59                    CURLPROTO_FTP | CURLPROTO_FTPS | \
  60                    CURLPROTO_TFTP)
  61
  62 #define CURL_NUM_STATES 8
  63 #define CURL_NUM_ACB    8
  64 #define SECTOR_SIZE     512
  65 #define READ_AHEAD_DEFAULT (256 * 1024)
  66
  67 #define FIND_RET_NONE   0
  68 #define FIND_RET_OK     1
  69 #define FIND_RET_WAIT   2
  70
  71 #define CURL_BLOCK_OPT_URL       "url"
  72 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  73 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  74
  75 struct BDRVCURLState;
  76
  77 typedef struct CURLAIOCB {
  78     BlockDriverAIOCB common;
  79     QEMUBH *bh;
  80     QEMUIOVector *qiov;
  81
  82     int64_t sector_num;
  83     int nb_sectors;
  84
  85     size_t start;
  86     size_t end;
  87 } CURLAIOCB;
  88
  89 typedef struct CURLState
  90 {
  91     struct BDRVCURLState *s;
  92     CURLAIOCB *acb[CURL_NUM_ACB];
  93     CURL *curl;
  94     curl_socket_t sock_fd;
  95     char *orig_buf;
  96     size_t buf_start;
  97     size_t buf_off;
  98     size_t buf_len;
  99     char range[128];
 100     char errmsg[CURL_ERROR_SIZE];
 101     char in_use;
 102 } CURLState;
 103
 104 typedef struct BDRVCURLState {
 105     CURLM *multi;
 106     QEMUTimer timer;
 107     size_t len;
 108     CURLState states[CURL_NUM_STATES];
 109     char *url;
 110     size_t readahead_size;
 111     bool sslverify;
 112     bool accept_range;
 113     AioContext *aio_context;
 114 } BDRVCURLState;
 115
 116 static void curl_clean_state(CURLState *s);
 117 static void curl_multi_do(void *arg);
 118 static void curl_multi_read(void *arg);
 119
 120 #ifdef NEED_CURL_TIMER_CALLBACK
 121 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 122 {
 123     BDRVCURLState *s = opaque;
 124
 125     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
 126     if (timeout_ms == -1) {
 127         timer_del(&s->timer);
 128     } else {
 129         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 130         timer_mod(&s->timer,
 131                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 132     }
 133     return 0;
 134 }
 135 #endif
 136
 137 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 138                         void *userp, void *sp)
 139 {
 140     BDRVCURLState *s;
 141     CURLState *state = NULL;
 142     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 143     state->sock_fd = fd;
 144     s = state->s;
 145
 146     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, fd);
 147     switch (action) {
 148         case CURL_POLL_IN:
 149             aio_set_fd_handler(s->aio_context, fd, curl_multi_read,
 150                                NULL, state);
 151             break;
 152         case CURL_POLL_OUT:
 153             aio_set_fd_handler(s->aio_context, fd, NULL, curl_multi_do, state);
 154             break;
 155         case CURL_POLL_INOUT:
 156             aio_set_fd_handler(s->aio_context, fd, curl_multi_read,
 157                                curl_multi_do, state);
 158             break;
 159         case CURL_POLL_REMOVE:
 160             aio_set_fd_handler(s->aio_context, fd, NULL, NULL, NULL);
 161             break;
 162     }
 163
 164     return 0;
 165 }
 166
 167 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 168 {
 169     BDRVCURLState *s = opaque;
 170     size_t realsize = size * nmemb;
 171     const char *accept_line = "Accept-Ranges: bytes";
 172
 173     if (realsize >= strlen(accept_line)
 174         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
 175         s->accept_range = true;
 176     }
 177
 178     return realsize;
 179 }
 180
 181 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 182 {
 183     CURLState *s = ((CURLState*)opaque);
 184     size_t realsize = size * nmemb;
 185     int i;
 186
 187     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
 188
 189     if (!s || !s->orig_buf)
 190         return 0;
 191
 192     if (s->buf_off >= s->buf_len) {
 193         /* buffer full, read nothing */
 194         return 0;
 195     }
 196     realsize = MIN(realsize, s->buf_len - s->buf_off);
 197     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 198     s->buf_off += realsize;
 199
 200     for(i=0; i<CURL_NUM_ACB; i++) {
 201         CURLAIOCB *acb = s->acb[i];
 202
 203         if (!acb)
 204             continue;
 205
 206         if ((s->buf_off >= acb->end)) {
 207             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
 208                                 acb->end - acb->start);
 209             acb->common.cb(acb->common.opaque, 0);
 210             qemu_aio_release(acb);
 211             s->acb[i] = NULL;
 212         }
 213     }
 214
 215     return realsize;
 216 }
 217
 218 static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len,
 219                          CURLAIOCB *acb)
 220 {
 221     int i;
 222     size_t end = start + len;
 223
 224     for (i=0; i<CURL_NUM_STATES; i++) {
 225         CURLState *state = &s->states[i];
 226         size_t buf_end = (state->buf_start + state->buf_off);
 227         size_t buf_fend = (state->buf_start + state->buf_len);
 228
 229         if (!state->orig_buf)
 230             continue;
 231         if (!state->buf_off)
 232             continue;
 233
 234         // Does the existing buffer cover our section?
 235         if ((start >= state->buf_start) &&
 236             (start <= buf_end) &&
 237             (end >= state->buf_start) &&
 238             (end <= buf_end))
 239         {
 240             char *buf = state->orig_buf + (start - state->buf_start);
 241
 242             qemu_iovec_from_buf(acb->qiov, 0, buf, len);
 243             acb->common.cb(acb->common.opaque, 0);
 244
 245             return FIND_RET_OK;
 246         }
 247
 248         // Wait for unfinished chunks
 249         if (state->in_use &&
 250             (start >= state->buf_start) &&
 251             (start <= buf_fend) &&
 252             (end >= state->buf_start) &&
 253             (end <= buf_fend))
 254         {
 255             int j;
 256
 257             acb->start = start - state->buf_start;
 258             acb->end = acb->start + len;
 259
 260             for (j=0; j<CURL_NUM_ACB; j++) {
 261                 if (!state->acb[j]) {
 262                     state->acb[j] = acb;
 263                     return FIND_RET_WAIT;
 264                 }
 265             }
 266         }
 267     }
 268
 269     return FIND_RET_NONE;
 270 }
 271
 272 static void curl_multi_check_completion(BDRVCURLState *s)
 273 {
 274     int msgs_in_queue;
 275
 276     /* Try to find done transfers, so we can free the easy
 277      * handle again. */
 278     for (;;) {
 279         CURLMsg *msg;
 280         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 281
 282         /* Quit when there are no more completions */
 283         if (!msg)
 284             break;
 285
 286         if (msg->msg == CURLMSG_DONE) {
 287             CURLState *state = NULL;
 288             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 289                               (char **)&state);
 290
 291             /* ACBs for successful messages get completed in curl_read_cb */
 292             if (msg->data.result != CURLE_OK) {
 293                 int i;
 294                 for (i = 0; i < CURL_NUM_ACB; i++) {
 295                     CURLAIOCB *acb = state->acb[i];
 296
 297                     if (acb == NULL) {
 298                         continue;
 299                     }
 300
 301                     acb->common.cb(acb->common.opaque, -EIO);
 302                     qemu_aio_release(acb);
 303                     state->acb[i] = NULL;
 304                 }
 305             }
 306
 307             curl_clean_state(state);
 308             break;
 309         }
 310     }
 311 }
 312
 313 static void curl_multi_do(void *arg)
 314 {
 315     CURLState *s = (CURLState *)arg;
 316     int running;
 317     int r;
 318
 319     if (!s->s->multi) {
 320         return;
 321     }
 322
 323     do {
 324         r = curl_multi_socket_action(s->s->multi, s->sock_fd, 0, &running);
 325     } while(r == CURLM_CALL_MULTI_PERFORM);
 326
 327 }
 328
 329 static void curl_multi_read(void *arg)
 330 {
 331     CURLState *s = (CURLState *)arg;
 332
 333     curl_multi_do(arg);
 334     curl_multi_check_completion(s->s);
 335 }
 336
 337 static void curl_multi_timeout_do(void *arg)
 338 {
 339 #ifdef NEED_CURL_TIMER_CALLBACK
 340     BDRVCURLState *s = (BDRVCURLState *)arg;
 341     int running;
 342
 343     if (!s->multi) {
 344         return;
 345     }
 346
 347     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 348
 349     curl_multi_check_completion(s);
 350 #else
 351     abort();
 352 #endif
 353 }
 354
 355 static CURLState *curl_init_state(BDRVCURLState *s)
 356 {
 357     CURLState *state = NULL;
 358     int i, j;
 359
 360     do {
 361         for (i=0; i<CURL_NUM_STATES; i++) {
 362             for (j=0; j<CURL_NUM_ACB; j++)
 363                 if (s->states[i].acb[j])
 364                     continue;
 365             if (s->states[i].in_use)
 366                 continue;
 367
 368             state = &s->states[i];
 369             state->in_use = 1;
 370             break;
 371         }
 372         if (!state) {
 373             aio_poll(state->s->aio_context, true);
 374         }
 375     } while(!state);
 376
 377     if (!state->curl) {
 378         state->curl = curl_easy_init();
 379         if (!state->curl) {
 380             return NULL;
 381         }
 382         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 383         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 384                          (long) s->sslverify);
 385         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, 5);
 386         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 387                          (void *)curl_read_cb);
 388         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 389         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 390         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 391         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 392         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 393         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 394         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 395
 396         /* Restrict supported protocols to avoid security issues in the more
 397          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 398          * CVE-2013-0249.
 399          *
 400          * Restricting protocols is only supported from 7.19.4 upwards.
 401          */
 402 #if LIBCURL_VERSION_NUM >= 0x071304
 403         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 404         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 405 #endif
 406
 407 #ifdef DEBUG_VERBOSE
 408         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 409 #endif
 410     }
 411
 412     state->s = s;
 413
 414     return state;
 415 }
 416
 417 static void curl_clean_state(CURLState *s)
 418 {
 419     if (s->s->multi)
 420         curl_multi_remove_handle(s->s->multi, s->curl);
 421     s->in_use = 0;
 422 }
 423
 424 static void curl_parse_filename(const char *filename, QDict *options,
 425                                 Error **errp)
 426 {
 427     qdict_put(options, CURL_BLOCK_OPT_URL, qstring_from_str(filename));
 428 }
 429
 430 static void curl_detach_aio_context(BlockDriverState *bs)
 431 {
 432     BDRVCURLState *s = bs->opaque;
 433     int i;
 434
 435     for (i = 0; i < CURL_NUM_STATES; i++) {
 436         if (s->states[i].in_use) {
 437             curl_clean_state(&s->states[i]);
 438         }
 439         if (s->states[i].curl) {
 440             curl_easy_cleanup(s->states[i].curl);
 441             s->states[i].curl = NULL;
 442         }
 443         if (s->states[i].orig_buf) {
 444             g_free(s->states[i].orig_buf);
 445             s->states[i].orig_buf = NULL;
 446         }
 447     }
 448     if (s->multi) {
 449         curl_multi_cleanup(s->multi);
 450         s->multi = NULL;
 451     }
 452
 453     timer_del(&s->timer);
 454 }
 455
 456 static void curl_attach_aio_context(BlockDriverState *bs,
 457                                     AioContext *new_context)
 458 {
 459     BDRVCURLState *s = bs->opaque;
 460
 461     aio_timer_init(new_context, &s->timer,
 462                    QEMU_CLOCK_REALTIME, SCALE_NS,
 463                    curl_multi_timeout_do, s);
 464
 465     assert(!s->multi);
 466     s->multi = curl_multi_init();
 467     s->aio_context = new_context;
 468     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 469 #ifdef NEED_CURL_TIMER_CALLBACK
 470     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 471     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 472 #endif
 473 }
 474
 475 static QemuOptsList runtime_opts = {
 476     .name = "curl",
 477     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 478     .desc = {
 479         {
 480             .name = CURL_BLOCK_OPT_URL,
 481             .type = QEMU_OPT_STRING,
 482             .help = "URL to open",
 483         },
 484         {
 485             .name = CURL_BLOCK_OPT_READAHEAD,
 486             .type = QEMU_OPT_SIZE,
 487             .help = "Readahead size",
 488         },
 489         {
 490             .name = CURL_BLOCK_OPT_SSLVERIFY,
 491             .type = QEMU_OPT_BOOL,
 492             .help = "Verify SSL certificate"
 493         },
 494         { /* end of list */ }
 495     },
 496 };
 497
 498 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 499                      Error **errp)
 500 {
 501     BDRVCURLState *s = bs->opaque;
 502     CURLState *state = NULL;
 503     QemuOpts *opts;
 504     Error *local_err = NULL;
 505     const char *file;
 506     double d;
 507
 508     static int inited = 0;
 509
 510     if (flags & BDRV_O_RDWR) {
 511         error_setg(errp, "curl block device does not support writes");
 512         return -EROFS;
 513     }
 514
 515     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 516     qemu_opts_absorb_qdict(opts, options, &local_err);
 517     if (local_err) {
 518         error_propagate(errp, local_err);
 519         goto out_noclean;
 520     }
 521
 522     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 523                                           READ_AHEAD_DEFAULT);
 524     if ((s->readahead_size & 0x1ff) != 0) {
 525         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 526                    s->readahead_size);
 527         goto out_noclean;
 528     }
 529
 530     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
 531
 532     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 533     if (file == NULL) {
 534         error_setg(errp, "curl block driver requires an 'url' option");
 535         goto out_noclean;
 536     }
 537
 538     if (!inited) {
 539         curl_global_init(CURL_GLOBAL_ALL);
 540         inited = 1;
 541     }
 542
 543     DPRINTF("CURL: Opening %s\n", file);
 544     s->aio_context = bdrv_get_aio_context(bs);
 545     s->url = g_strdup(file);
 546     state = curl_init_state(s);
 547     if (!state)
 548         goto out_noclean;
 549
 550     // Get file size
 551
 552     s->accept_range = false;
 553     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 554     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 555                      curl_header_cb);
 556     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 557     if (curl_easy_perform(state->curl))
 558         goto out;
 559     curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d);
 560     if (d)
 561         s->len = (size_t)d;
 562     else if(!s->len)
 563         goto out;
 564     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 565         || !strncasecmp(s->url, "https://", strlen("https://")))
 566         && !s->accept_range) {
 567         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 568                 "Server does not support 'range' (byte ranges).");
 569         goto out;
 570     }
 571     DPRINTF("CURL: Size = %zd\n", s->len);
 572
 573     curl_clean_state(state);
 574     curl_easy_cleanup(state->curl);
 575     state->curl = NULL;
 576
 577     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 578
 579     qemu_opts_del(opts);
 580     return 0;
 581
 582 out:
 583     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 584     curl_easy_cleanup(state->curl);
 585     state->curl = NULL;
 586 out_noclean:
 587     g_free(s->url);
 588     qemu_opts_del(opts);
 589     return -EINVAL;
 590 }
 591
 592 static void curl_aio_cancel(BlockDriverAIOCB *blockacb)
 593 {
 594     // Do we have to implement canceling? Seems to work without...
 595 }
 596
 597 static const AIOCBInfo curl_aiocb_info = {
 598     .aiocb_size         = sizeof(CURLAIOCB),
 599     .cancel             = curl_aio_cancel,
 600 };
 601
 602
 603 static void curl_readv_bh_cb(void *p)
 604 {
 605     CURLState *state;
 606     int running;
 607
 608     CURLAIOCB *acb = p;
 609     BDRVCURLState *s = acb->common.bs->opaque;
 610
 611     qemu_bh_delete(acb->bh);
 612     acb->bh = NULL;
 613
 614     size_t start = acb->sector_num * SECTOR_SIZE;
 615     size_t end;
 616
 617     // In case we have the requested data already (e.g. read-ahead),
 618     // we can just call the callback and be done.
 619     switch (curl_find_buf(s, start, acb->nb_sectors * SECTOR_SIZE, acb)) {
 620         case FIND_RET_OK:
 621             qemu_aio_release(acb);
 622             // fall through
 623         case FIND_RET_WAIT:
 624             return;
 625         default:
 626             break;
 627     }
 628
 629     // No cache found, so let's start a new request
 630     state = curl_init_state(s);
 631     if (!state) {
 632         acb->common.cb(acb->common.opaque, -EIO);
 633         qemu_aio_release(acb);
 634         return;
 635     }
 636
 637     acb->start = 0;
 638     acb->end = (acb->nb_sectors * SECTOR_SIZE);
 639
 640     state->buf_off = 0;
 641     if (state->orig_buf)
 642         g_free(state->orig_buf);
 643     state->buf_start = start;
 644     state->buf_len = acb->end + s->readahead_size;
 645     end = MIN(start + state->buf_len, s->len) - 1;
 646     state->orig_buf = g_malloc(state->buf_len);
 647     state->acb[0] = acb;
 648
 649     snprintf(state->range, 127, "%zd-%zd", start, end);
 650     DPRINTF("CURL (AIO): Reading %d at %zd (%s)\n",
 651             (acb->nb_sectors * SECTOR_SIZE), start, state->range);
 652     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 653
 654     curl_multi_add_handle(s->multi, state->curl);
 655
 656     /* Tell curl it needs to kick things off */
 657     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 658 }
 659
 660 static BlockDriverAIOCB *curl_aio_readv(BlockDriverState *bs,
 661         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 662         BlockDriverCompletionFunc *cb, void *opaque)
 663 {
 664     CURLAIOCB *acb;
 665
 666     acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque);
 667
 668     acb->qiov = qiov;
 669     acb->sector_num = sector_num;
 670     acb->nb_sectors = nb_sectors;
 671
 672     acb->bh = aio_bh_new(bdrv_get_aio_context(bs), curl_readv_bh_cb, acb);
 673     qemu_bh_schedule(acb->bh);
 674     return &acb->common;
 675 }
 676
 677 static void curl_close(BlockDriverState *bs)
 678 {
 679     BDRVCURLState *s = bs->opaque;
 680
 681     DPRINTF("CURL: Close\n");
 682     curl_detach_aio_context(bs);
 683
 684     g_free(s->url);
 685 }
 686
 687 static int64_t curl_getlength(BlockDriverState *bs)
 688 {
 689     BDRVCURLState *s = bs->opaque;
 690     return s->len;
 691 }
 692
 693 static BlockDriver bdrv_http = {
 694     .format_name                = "http",
 695     .protocol_name              = "http",
 696
 697     .instance_size              = sizeof(BDRVCURLState),
 698     .bdrv_parse_filename        = curl_parse_filename,
 699     .bdrv_file_open             = curl_open,
 700     .bdrv_close                 = curl_close,
 701     .bdrv_getlength             = curl_getlength,
 702
 703     .bdrv_aio_readv             = curl_aio_readv,
 704
 705     .bdrv_detach_aio_context    = curl_detach_aio_context,
 706     .bdrv_attach_aio_context    = curl_attach_aio_context,
 707 };
 708
 709 static BlockDriver bdrv_https = {
 710     .format_name                = "https",
 711     .protocol_name              = "https",
 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     .bdrv_detach_aio_context    = curl_detach_aio_context,
 722     .bdrv_attach_aio_context    = curl_attach_aio_context,
 723 };
 724
 725 static BlockDriver bdrv_ftp = {
 726     .format_name                = "ftp",
 727     .protocol_name              = "ftp",
 728
 729     .instance_size              = sizeof(BDRVCURLState),
 730     .bdrv_parse_filename        = curl_parse_filename,
 731     .bdrv_file_open             = curl_open,
 732     .bdrv_close                 = curl_close,
 733     .bdrv_getlength             = curl_getlength,
 734
 735     .bdrv_aio_readv             = curl_aio_readv,
 736
 737     .bdrv_detach_aio_context    = curl_detach_aio_context,
 738     .bdrv_attach_aio_context    = curl_attach_aio_context,
 739 };
 740
 741 static BlockDriver bdrv_ftps = {
 742     .format_name                = "ftps",
 743     .protocol_name              = "ftps",
 744
 745     .instance_size              = sizeof(BDRVCURLState),
 746     .bdrv_parse_filename        = curl_parse_filename,
 747     .bdrv_file_open             = curl_open,
 748     .bdrv_close                 = curl_close,
 749     .bdrv_getlength             = curl_getlength,
 750
 751     .bdrv_aio_readv             = curl_aio_readv,
 752
 753     .bdrv_detach_aio_context    = curl_detach_aio_context,
 754     .bdrv_attach_aio_context    = curl_attach_aio_context,
 755 };
 756
 757 static BlockDriver bdrv_tftp = {
 758     .format_name                = "tftp",
 759     .protocol_name              = "tftp",
 760
 761     .instance_size              = sizeof(BDRVCURLState),
 762     .bdrv_parse_filename        = curl_parse_filename,
 763     .bdrv_file_open             = curl_open,
 764     .bdrv_close                 = curl_close,
 765     .bdrv_getlength             = curl_getlength,
 766
 767     .bdrv_aio_readv             = curl_aio_readv,
 768
 769     .bdrv_detach_aio_context    = curl_detach_aio_context,
 770     .bdrv_attach_aio_context    = curl_attach_aio_context,
 771 };
 772
 773 static void curl_block_init(void)
 774 {
 775     bdrv_register(&bdrv_http);
 776     bdrv_register(&bdrv_https);
 777     bdrv_register(&bdrv_ftp);
 778     bdrv_register(&bdrv_ftps);
 779     bdrv_register(&bdrv_tftp);
 780 }
 781
 782 block_init(curl_block_init);