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 "qemu/error-report.h"
  26 #include "block/block_int.h"
  27 #include "qapi/qmp/qbool.h"
  28 #include "qapi/qmp/qstring.h"
  29 #include <curl/curl.h>
  30
  31 // #define DEBUG_CURL
  32 // #define DEBUG_VERBOSE
  33
  34 #ifdef DEBUG_CURL
  35 #define DPRINTF(fmt, ...) do { printf(fmt, ## __VA_ARGS__); } while (0)
  36 #else
  37 #define DPRINTF(fmt, ...) do { } while (0)
  38 #endif
  39
  40 #if LIBCURL_VERSION_NUM >= 0x071000
  41 /* The multi interface timer callback was introduced in 7.16.0 */
  42 #define NEED_CURL_TIMER_CALLBACK
  43 #define HAVE_SOCKET_ACTION
  44 #endif
  45
  46 #ifndef HAVE_SOCKET_ACTION
  47 /* If curl_multi_socket_action isn't available, define it statically here in
  48  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
  49  * less efficient but still safe. */
  50 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
  51                                             curl_socket_t sockfd,
  52                                             int ev_bitmask,
  53                                             int *running_handles)
  54 {
  55     return curl_multi_socket(multi_handle, sockfd, running_handles);
  56 }
  57 #define curl_multi_socket_action __curl_multi_socket_action
  58 #endif
  59
  60 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  61                    CURLPROTO_FTP | CURLPROTO_FTPS | \
  62                    CURLPROTO_TFTP)
  63
  64 #define CURL_NUM_STATES 8
  65 #define CURL_NUM_ACB    8
  66 #define SECTOR_SIZE     512
  67 #define READ_AHEAD_DEFAULT (256 * 1024)
  68 #define CURL_TIMEOUT_DEFAULT 5
  69 #define CURL_TIMEOUT_MAX 10000
  70
  71 #define FIND_RET_NONE   0
  72 #define FIND_RET_OK     1
  73 #define FIND_RET_WAIT   2
  74
  75 #define CURL_BLOCK_OPT_URL       "url"
  76 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  77 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  78 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
  79 #define CURL_BLOCK_OPT_COOKIE    "cookie"
  80
  81 struct BDRVCURLState;
  82
  83 typedef struct CURLAIOCB {
  84     BlockAIOCB common;
  85     QEMUBH *bh;
  86     QEMUIOVector *qiov;
  87
  88     int64_t sector_num;
  89     int nb_sectors;
  90
  91     size_t start;
  92     size_t end;
  93 } CURLAIOCB;
  94
  95 typedef struct CURLState
  96 {
  97     struct BDRVCURLState *s;
  98     CURLAIOCB *acb[CURL_NUM_ACB];
  99     CURL *curl;
 100     curl_socket_t sock_fd;
 101     char *orig_buf;
 102     size_t buf_start;
 103     size_t buf_off;
 104     size_t buf_len;
 105     char range[128];
 106     char errmsg[CURL_ERROR_SIZE];
 107     char in_use;
 108 } CURLState;
 109
 110 typedef struct BDRVCURLState {
 111     CURLM *multi;
 112     QEMUTimer timer;
 113     size_t len;
 114     CURLState states[CURL_NUM_STATES];
 115     char *url;
 116     size_t readahead_size;
 117     bool sslverify;
 118     uint64_t timeout;
 119     char *cookie;
 120     bool accept_range;
 121     AioContext *aio_context;
 122 } BDRVCURLState;
 123
 124 static void curl_clean_state(CURLState *s);
 125 static void curl_multi_do(void *arg);
 126 static void curl_multi_read(void *arg);
 127
 128 #ifdef NEED_CURL_TIMER_CALLBACK
 129 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 130 {
 131     BDRVCURLState *s = opaque;
 132
 133     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
 134     if (timeout_ms == -1) {
 135         timer_del(&s->timer);
 136     } else {
 137         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 138         timer_mod(&s->timer,
 139                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 140     }
 141     return 0;
 142 }
 143 #endif
 144
 145 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 146                         void *userp, void *sp)
 147 {
 148     BDRVCURLState *s;
 149     CURLState *state = NULL;
 150     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 151     state->sock_fd = fd;
 152     s = state->s;
 153
 154     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, fd);
 155     switch (action) {
 156         case CURL_POLL_IN:
 157             aio_set_fd_handler(s->aio_context, fd, false,
 158                                curl_multi_read, NULL, state);
 159             break;
 160         case CURL_POLL_OUT:
 161             aio_set_fd_handler(s->aio_context, fd, false,
 162                                NULL, curl_multi_do, state);
 163             break;
 164         case CURL_POLL_INOUT:
 165             aio_set_fd_handler(s->aio_context, fd, false,
 166                                curl_multi_read, curl_multi_do, state);
 167             break;
 168         case CURL_POLL_REMOVE:
 169             aio_set_fd_handler(s->aio_context, fd, false,
 170                                NULL, NULL, NULL);
 171             break;
 172     }
 173
 174     return 0;
 175 }
 176
 177 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 178 {
 179     BDRVCURLState *s = opaque;
 180     size_t realsize = size * nmemb;
 181     const char *accept_line = "Accept-Ranges: bytes";
 182
 183     if (realsize >= strlen(accept_line)
 184         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
 185         s->accept_range = true;
 186     }
 187
 188     return realsize;
 189 }
 190
 191 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 192 {
 193     CURLState *s = ((CURLState*)opaque);
 194     size_t realsize = size * nmemb;
 195     int i;
 196
 197     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
 198
 199     if (!s || !s->orig_buf)
 200         return 0;
 201
 202     if (s->buf_off >= s->buf_len) {
 203         /* buffer full, read nothing */
 204         return 0;
 205     }
 206     realsize = MIN(realsize, s->buf_len - s->buf_off);
 207     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 208     s->buf_off += realsize;
 209
 210     for(i=0; i<CURL_NUM_ACB; i++) {
 211         CURLAIOCB *acb = s->acb[i];
 212
 213         if (!acb)
 214             continue;
 215
 216         if ((s->buf_off >= acb->end)) {
 217             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
 218                                 acb->end - acb->start);
 219             acb->common.cb(acb->common.opaque, 0);
 220             qemu_aio_unref(acb);
 221             s->acb[i] = NULL;
 222         }
 223     }
 224
 225     return realsize;
 226 }
 227
 228 static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len,
 229                          CURLAIOCB *acb)
 230 {
 231     int i;
 232     size_t end = start + len;
 233
 234     for (i=0; i<CURL_NUM_STATES; i++) {
 235         CURLState *state = &s->states[i];
 236         size_t buf_end = (state->buf_start + state->buf_off);
 237         size_t buf_fend = (state->buf_start + state->buf_len);
 238
 239         if (!state->orig_buf)
 240             continue;
 241         if (!state->buf_off)
 242             continue;
 243
 244         // Does the existing buffer cover our section?
 245         if ((start >= state->buf_start) &&
 246             (start <= buf_end) &&
 247             (end >= state->buf_start) &&
 248             (end <= buf_end))
 249         {
 250             char *buf = state->orig_buf + (start - state->buf_start);
 251
 252             qemu_iovec_from_buf(acb->qiov, 0, buf, len);
 253             acb->common.cb(acb->common.opaque, 0);
 254
 255             return FIND_RET_OK;
 256         }
 257
 258         // Wait for unfinished chunks
 259         if (state->in_use &&
 260             (start >= state->buf_start) &&
 261             (start <= buf_fend) &&
 262             (end >= state->buf_start) &&
 263             (end <= buf_fend))
 264         {
 265             int j;
 266
 267             acb->start = start - state->buf_start;
 268             acb->end = acb->start + len;
 269
 270             for (j=0; j<CURL_NUM_ACB; j++) {
 271                 if (!state->acb[j]) {
 272                     state->acb[j] = acb;
 273                     return FIND_RET_WAIT;
 274                 }
 275             }
 276         }
 277     }
 278
 279     return FIND_RET_NONE;
 280 }
 281
 282 static void curl_multi_check_completion(BDRVCURLState *s)
 283 {
 284     int msgs_in_queue;
 285
 286     /* Try to find done transfers, so we can free the easy
 287      * handle again. */
 288     for (;;) {
 289         CURLMsg *msg;
 290         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 291
 292         /* Quit when there are no more completions */
 293         if (!msg)
 294             break;
 295
 296         if (msg->msg == CURLMSG_DONE) {
 297             CURLState *state = NULL;
 298             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 299                               (char **)&state);
 300
 301             /* ACBs for successful messages get completed in curl_read_cb */
 302             if (msg->data.result != CURLE_OK) {
 303                 int i;
 304                 static int errcount = 100;
 305
 306                 /* Don't lose the original error message from curl, since
 307                  * it contains extra data.
 308                  */
 309                 if (errcount > 0) {
 310                     error_report("curl: %s", state->errmsg);
 311                     if (--errcount == 0) {
 312                         error_report("curl: further errors suppressed");
 313                     }
 314                 }
 315
 316                 for (i = 0; i < CURL_NUM_ACB; i++) {
 317                     CURLAIOCB *acb = state->acb[i];
 318
 319                     if (acb == NULL) {
 320                         continue;
 321                     }
 322
 323                     acb->common.cb(acb->common.opaque, -EPROTO);
 324                     qemu_aio_unref(acb);
 325                     state->acb[i] = NULL;
 326                 }
 327             }
 328
 329             curl_clean_state(state);
 330             break;
 331         }
 332     }
 333 }
 334
 335 static void curl_multi_do(void *arg)
 336 {
 337     CURLState *s = (CURLState *)arg;
 338     int running;
 339     int r;
 340
 341     if (!s->s->multi) {
 342         return;
 343     }
 344
 345     do {
 346         r = curl_multi_socket_action(s->s->multi, s->sock_fd, 0, &running);
 347     } while(r == CURLM_CALL_MULTI_PERFORM);
 348
 349 }
 350
 351 static void curl_multi_read(void *arg)
 352 {
 353     CURLState *s = (CURLState *)arg;
 354
 355     curl_multi_do(arg);
 356     curl_multi_check_completion(s->s);
 357 }
 358
 359 static void curl_multi_timeout_do(void *arg)
 360 {
 361 #ifdef NEED_CURL_TIMER_CALLBACK
 362     BDRVCURLState *s = (BDRVCURLState *)arg;
 363     int running;
 364
 365     if (!s->multi) {
 366         return;
 367     }
 368
 369     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 370
 371     curl_multi_check_completion(s);
 372 #else
 373     abort();
 374 #endif
 375 }
 376
 377 static CURLState *curl_init_state(BlockDriverState *bs, BDRVCURLState *s)
 378 {
 379     CURLState *state = NULL;
 380     int i, j;
 381
 382     do {
 383         for (i=0; i<CURL_NUM_STATES; i++) {
 384             for (j=0; j<CURL_NUM_ACB; j++)
 385                 if (s->states[i].acb[j])
 386                     continue;
 387             if (s->states[i].in_use)
 388                 continue;
 389
 390             state = &s->states[i];
 391             state->in_use = 1;
 392             break;
 393         }
 394         if (!state) {
 395             aio_poll(bdrv_get_aio_context(bs), true);
 396         }
 397     } while(!state);
 398
 399     if (!state->curl) {
 400         state->curl = curl_easy_init();
 401         if (!state->curl) {
 402             return NULL;
 403         }
 404         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 405         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 406                          (long) s->sslverify);
 407         if (s->cookie) {
 408             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
 409         }
 410         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
 411         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 412                          (void *)curl_read_cb);
 413         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 414         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 415         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 416         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 417         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 418         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 419         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 420
 421         /* Restrict supported protocols to avoid security issues in the more
 422          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 423          * CVE-2013-0249.
 424          *
 425          * Restricting protocols is only supported from 7.19.4 upwards.
 426          */
 427 #if LIBCURL_VERSION_NUM >= 0x071304
 428         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 429         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 430 #endif
 431
 432 #ifdef DEBUG_VERBOSE
 433         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 434 #endif
 435     }
 436
 437     state->s = s;
 438
 439     return state;
 440 }
 441
 442 static void curl_clean_state(CURLState *s)
 443 {
 444     if (s->s->multi)
 445         curl_multi_remove_handle(s->s->multi, s->curl);
 446     s->in_use = 0;
 447 }
 448
 449 static void curl_parse_filename(const char *filename, QDict *options,
 450                                 Error **errp)
 451 {
 452     qdict_put(options, CURL_BLOCK_OPT_URL, qstring_from_str(filename));
 453 }
 454
 455 static void curl_detach_aio_context(BlockDriverState *bs)
 456 {
 457     BDRVCURLState *s = bs->opaque;
 458     int i;
 459
 460     for (i = 0; i < CURL_NUM_STATES; i++) {
 461         if (s->states[i].in_use) {
 462             curl_clean_state(&s->states[i]);
 463         }
 464         if (s->states[i].curl) {
 465             curl_easy_cleanup(s->states[i].curl);
 466             s->states[i].curl = NULL;
 467         }
 468         g_free(s->states[i].orig_buf);
 469         s->states[i].orig_buf = NULL;
 470     }
 471     if (s->multi) {
 472         curl_multi_cleanup(s->multi);
 473         s->multi = NULL;
 474     }
 475
 476     timer_del(&s->timer);
 477 }
 478
 479 static void curl_attach_aio_context(BlockDriverState *bs,
 480                                     AioContext *new_context)
 481 {
 482     BDRVCURLState *s = bs->opaque;
 483
 484     aio_timer_init(new_context, &s->timer,
 485                    QEMU_CLOCK_REALTIME, SCALE_NS,
 486                    curl_multi_timeout_do, s);
 487
 488     assert(!s->multi);
 489     s->multi = curl_multi_init();
 490     s->aio_context = new_context;
 491     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 492 #ifdef NEED_CURL_TIMER_CALLBACK
 493     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 494     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 495 #endif
 496 }
 497
 498 static QemuOptsList runtime_opts = {
 499     .name = "curl",
 500     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 501     .desc = {
 502         {
 503             .name = CURL_BLOCK_OPT_URL,
 504             .type = QEMU_OPT_STRING,
 505             .help = "URL to open",
 506         },
 507         {
 508             .name = CURL_BLOCK_OPT_READAHEAD,
 509             .type = QEMU_OPT_SIZE,
 510             .help = "Readahead size",
 511         },
 512         {
 513             .name = CURL_BLOCK_OPT_SSLVERIFY,
 514             .type = QEMU_OPT_BOOL,
 515             .help = "Verify SSL certificate"
 516         },
 517         {
 518             .name = CURL_BLOCK_OPT_TIMEOUT,
 519             .type = QEMU_OPT_NUMBER,
 520             .help = "Curl timeout"
 521         },
 522         {
 523             .name = CURL_BLOCK_OPT_COOKIE,
 524             .type = QEMU_OPT_STRING,
 525             .help = "Pass the cookie or list of cookies with each request"
 526         },
 527         { /* end of list */ }
 528     },
 529 };
 530
 531 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 532                      Error **errp)
 533 {
 534     BDRVCURLState *s = bs->opaque;
 535     CURLState *state = NULL;
 536     QemuOpts *opts;
 537     Error *local_err = NULL;
 538     const char *file;
 539     const char *cookie;
 540     double d;
 541
 542     static int inited = 0;
 543
 544     if (flags & BDRV_O_RDWR) {
 545         error_setg(errp, "curl block device does not support writes");
 546         return -EROFS;
 547     }
 548
 549     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 550     qemu_opts_absorb_qdict(opts, options, &local_err);
 551     if (local_err) {
 552         error_propagate(errp, local_err);
 553         goto out_noclean;
 554     }
 555
 556     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 557                                           READ_AHEAD_DEFAULT);
 558     if ((s->readahead_size & 0x1ff) != 0) {
 559         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 560                    s->readahead_size);
 561         goto out_noclean;
 562     }
 563
 564     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 565                                      CURL_TIMEOUT_DEFAULT);
 566     if (s->timeout > CURL_TIMEOUT_MAX) {
 567         error_setg(errp, "timeout parameter is too large or negative");
 568         goto out_noclean;
 569     }
 570
 571     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
 572
 573     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 574     s->cookie = g_strdup(cookie);
 575
 576     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 577     if (file == NULL) {
 578         error_setg(errp, "curl block driver requires an 'url' option");
 579         goto out_noclean;
 580     }
 581
 582     if (!inited) {
 583         curl_global_init(CURL_GLOBAL_ALL);
 584         inited = 1;
 585     }
 586
 587     DPRINTF("CURL: Opening %s\n", file);
 588     s->aio_context = bdrv_get_aio_context(bs);
 589     s->url = g_strdup(file);
 590     state = curl_init_state(bs, s);
 591     if (!state)
 592         goto out_noclean;
 593
 594     // Get file size
 595
 596     s->accept_range = false;
 597     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 598     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 599                      curl_header_cb);
 600     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 601     if (curl_easy_perform(state->curl))
 602         goto out;
 603     curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d);
 604     if (d)
 605         s->len = (size_t)d;
 606     else if(!s->len)
 607         goto out;
 608     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 609         || !strncasecmp(s->url, "https://", strlen("https://")))
 610         && !s->accept_range) {
 611         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 612                 "Server does not support 'range' (byte ranges).");
 613         goto out;
 614     }
 615     DPRINTF("CURL: Size = %zd\n", s->len);
 616
 617     curl_clean_state(state);
 618     curl_easy_cleanup(state->curl);
 619     state->curl = NULL;
 620
 621     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 622
 623     qemu_opts_del(opts);
 624     return 0;
 625
 626 out:
 627     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 628     curl_easy_cleanup(state->curl);
 629     state->curl = NULL;
 630 out_noclean:
 631     g_free(s->cookie);
 632     g_free(s->url);
 633     qemu_opts_del(opts);
 634     return -EINVAL;
 635 }
 636
 637 static const AIOCBInfo curl_aiocb_info = {
 638     .aiocb_size         = sizeof(CURLAIOCB),
 639 };
 640
 641
 642 static void curl_readv_bh_cb(void *p)
 643 {
 644     CURLState *state;
 645     int running;
 646
 647     CURLAIOCB *acb = p;
 648     BDRVCURLState *s = acb->common.bs->opaque;
 649
 650     qemu_bh_delete(acb->bh);
 651     acb->bh = NULL;
 652
 653     size_t start = acb->sector_num * SECTOR_SIZE;
 654     size_t end;
 655
 656     // In case we have the requested data already (e.g. read-ahead),
 657     // we can just call the callback and be done.
 658     switch (curl_find_buf(s, start, acb->nb_sectors * SECTOR_SIZE, acb)) {
 659         case FIND_RET_OK:
 660             qemu_aio_unref(acb);
 661             // fall through
 662         case FIND_RET_WAIT:
 663             return;
 664         default:
 665             break;
 666     }
 667
 668     // No cache found, so let's start a new request
 669     state = curl_init_state(acb->common.bs, s);
 670     if (!state) {
 671         acb->common.cb(acb->common.opaque, -EIO);
 672         qemu_aio_unref(acb);
 673         return;
 674     }
 675
 676     acb->start = 0;
 677     acb->end = (acb->nb_sectors * SECTOR_SIZE);
 678
 679     state->buf_off = 0;
 680     g_free(state->orig_buf);
 681     state->buf_start = start;
 682     state->buf_len = acb->end + s->readahead_size;
 683     end = MIN(start + state->buf_len, s->len) - 1;
 684     state->orig_buf = g_try_malloc(state->buf_len);
 685     if (state->buf_len && state->orig_buf == NULL) {
 686         curl_clean_state(state);
 687         acb->common.cb(acb->common.opaque, -ENOMEM);
 688         qemu_aio_unref(acb);
 689         return;
 690     }
 691     state->acb[0] = acb;
 692
 693     snprintf(state->range, 127, "%zd-%zd", start, end);
 694     DPRINTF("CURL (AIO): Reading %d at %zd (%s)\n",
 695             (acb->nb_sectors * SECTOR_SIZE), start, state->range);
 696     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 697
 698     curl_multi_add_handle(s->multi, state->curl);
 699
 700     /* Tell curl it needs to kick things off */
 701     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 702 }
 703
 704 static BlockAIOCB *curl_aio_readv(BlockDriverState *bs,
 705         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 706         BlockCompletionFunc *cb, void *opaque)
 707 {
 708     CURLAIOCB *acb;
 709
 710     acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque);
 711
 712     acb->qiov = qiov;
 713     acb->sector_num = sector_num;
 714     acb->nb_sectors = nb_sectors;
 715
 716     acb->bh = aio_bh_new(bdrv_get_aio_context(bs), curl_readv_bh_cb, acb);
 717     qemu_bh_schedule(acb->bh);
 718     return &acb->common;
 719 }
 720
 721 static void curl_close(BlockDriverState *bs)
 722 {
 723     BDRVCURLState *s = bs->opaque;
 724
 725     DPRINTF("CURL: Close\n");
 726     curl_detach_aio_context(bs);
 727
 728     g_free(s->cookie);
 729     g_free(s->url);
 730 }
 731
 732 static int64_t curl_getlength(BlockDriverState *bs)
 733 {
 734     BDRVCURLState *s = bs->opaque;
 735     return s->len;
 736 }
 737
 738 static BlockDriver bdrv_http = {
 739     .format_name                = "http",
 740     .protocol_name              = "http",
 741
 742     .instance_size              = sizeof(BDRVCURLState),
 743     .bdrv_parse_filename        = curl_parse_filename,
 744     .bdrv_file_open             = curl_open,
 745     .bdrv_close                 = curl_close,
 746     .bdrv_getlength             = curl_getlength,
 747
 748     .bdrv_aio_readv             = curl_aio_readv,
 749
 750     .bdrv_detach_aio_context    = curl_detach_aio_context,
 751     .bdrv_attach_aio_context    = curl_attach_aio_context,
 752 };
 753
 754 static BlockDriver bdrv_https = {
 755     .format_name                = "https",
 756     .protocol_name              = "https",
 757
 758     .instance_size              = sizeof(BDRVCURLState),
 759     .bdrv_parse_filename        = curl_parse_filename,
 760     .bdrv_file_open             = curl_open,
 761     .bdrv_close                 = curl_close,
 762     .bdrv_getlength             = curl_getlength,
 763
 764     .bdrv_aio_readv             = curl_aio_readv,
 765
 766     .bdrv_detach_aio_context    = curl_detach_aio_context,
 767     .bdrv_attach_aio_context    = curl_attach_aio_context,
 768 };
 769
 770 static BlockDriver bdrv_ftp = {
 771     .format_name                = "ftp",
 772     .protocol_name              = "ftp",
 773
 774     .instance_size              = sizeof(BDRVCURLState),
 775     .bdrv_parse_filename        = curl_parse_filename,
 776     .bdrv_file_open             = curl_open,
 777     .bdrv_close                 = curl_close,
 778     .bdrv_getlength             = curl_getlength,
 779
 780     .bdrv_aio_readv             = curl_aio_readv,
 781
 782     .bdrv_detach_aio_context    = curl_detach_aio_context,
 783     .bdrv_attach_aio_context    = curl_attach_aio_context,
 784 };
 785
 786 static BlockDriver bdrv_ftps = {
 787     .format_name                = "ftps",
 788     .protocol_name              = "ftps",
 789
 790     .instance_size              = sizeof(BDRVCURLState),
 791     .bdrv_parse_filename        = curl_parse_filename,
 792     .bdrv_file_open             = curl_open,
 793     .bdrv_close                 = curl_close,
 794     .bdrv_getlength             = curl_getlength,
 795
 796     .bdrv_aio_readv             = curl_aio_readv,
 797
 798     .bdrv_detach_aio_context    = curl_detach_aio_context,
 799     .bdrv_attach_aio_context    = curl_attach_aio_context,
 800 };
 801
 802 static BlockDriver bdrv_tftp = {
 803     .format_name                = "tftp",
 804     .protocol_name              = "tftp",
 805
 806     .instance_size              = sizeof(BDRVCURLState),
 807     .bdrv_parse_filename        = curl_parse_filename,
 808     .bdrv_file_open             = curl_open,
 809     .bdrv_close                 = curl_close,
 810     .bdrv_getlength             = curl_getlength,
 811
 812     .bdrv_aio_readv             = curl_aio_readv,
 813
 814     .bdrv_detach_aio_context    = curl_detach_aio_context,
 815     .bdrv_attach_aio_context    = curl_attach_aio_context,
 816 };
 817
 818 static void curl_block_init(void)
 819 {
 820     bdrv_register(&bdrv_http);
 821     bdrv_register(&bdrv_https);
 822     bdrv_register(&bdrv_ftp);
 823     bdrv_register(&bdrv_ftps);
 824     bdrv_register(&bdrv_tftp);
 825 }
 826
 827 block_init(curl_block_init);