block/curl.c

   1 /*
   2  * QEMU Block driver for CURL images
   3  *
   4  * Copyright (c) 2009 Alexander Graf <[email protected]>
   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 #define CURL_TIMEOUT_DEFAULT 5
  67
  68 #define FIND_RET_NONE   0
  69 #define FIND_RET_OK     1
  70 #define FIND_RET_WAIT   2
  71
  72 #define CURL_BLOCK_OPT_URL       "url"
  73 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  74 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  75 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
  76 #define CURL_BLOCK_OPT_COOKIE    "cookie"
  77
  78 struct BDRVCURLState;
  79
  80 typedef struct CURLAIOCB {
  81     BlockDriverAIOCB common;
  82     QEMUBH *bh;
  83     QEMUIOVector *qiov;
  84
  85     int64_t sector_num;
  86     int nb_sectors;
  87
  88     size_t start;
  89     size_t end;
  90 } CURLAIOCB;
  91
  92 typedef struct CURLState
  93 {
  94     struct BDRVCURLState *s;
  95     CURLAIOCB *acb[CURL_NUM_ACB];
  96     CURL *curl;
  97     curl_socket_t sock_fd;
  98     char *orig_buf;
  99     size_t buf_start;
 100     size_t buf_off;
 101     size_t buf_len;
 102     char range[128];
 103     char errmsg[CURL_ERROR_SIZE];
 104     char in_use;
 105 } CURLState;
 106
 107 typedef struct BDRVCURLState {
 108     CURLM *multi;
 109     QEMUTimer timer;
 110     size_t len;
 111     CURLState states[CURL_NUM_STATES];
 112     char *url;
 113     size_t readahead_size;
 114     bool sslverify;
 115     int timeout;
 116     char *cookie;
 117     bool accept_range;
 118     AioContext *aio_context;
 119 } BDRVCURLState;
 120
 121 static void curl_clean_state(CURLState *s);
 122 static void curl_multi_do(void *arg);
 123 static void curl_multi_read(void *arg);
 124
 125 #ifdef NEED_CURL_TIMER_CALLBACK
 126 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 127 {
 128     BDRVCURLState *s = opaque;
 129
 130     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
 131     if (timeout_ms == -1) {
 132         timer_del(&s->timer);
 133     } else {
 134         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 135         timer_mod(&s->timer,
 136                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 137     }
 138     return 0;
 139 }
 140 #endif
 141
 142 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 143                         void *userp, void *sp)
 144 {
 145     BDRVCURLState *s;
 146     CURLState *state = NULL;
 147     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 148     state->sock_fd = fd;
 149     s = state->s;
 150
 151     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, fd);
 152     switch (action) {
 153         case CURL_POLL_IN:
 154             aio_set_fd_handler(s->aio_context, fd, curl_multi_read,
 155                                NULL, state);
 156             break;
 157         case CURL_POLL_OUT:
 158             aio_set_fd_handler(s->aio_context, fd, NULL, curl_multi_do, state);
 159             break;
 160         case CURL_POLL_INOUT:
 161             aio_set_fd_handler(s->aio_context, fd, curl_multi_read,
 162                                curl_multi_do, state);
 163             break;
 164         case CURL_POLL_REMOVE:
 165             aio_set_fd_handler(s->aio_context, fd, NULL, NULL, NULL);
 166             break;
 167     }
 168
 169     return 0;
 170 }
 171
 172 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 173 {
 174     BDRVCURLState *s = opaque;
 175     size_t realsize = size * nmemb;
 176     const char *accept_line = "Accept-Ranges: bytes";
 177
 178     if (realsize >= strlen(accept_line)
 179         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
 180         s->accept_range = true;
 181     }
 182
 183     return realsize;
 184 }
 185
 186 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 187 {
 188     CURLState *s = ((CURLState*)opaque);
 189     size_t realsize = size * nmemb;
 190     int i;
 191
 192     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
 193
 194     if (!s || !s->orig_buf)
 195         return 0;
 196
 197     if (s->buf_off >= s->buf_len) {
 198         /* buffer full, read nothing */
 199         return 0;
 200     }
 201     realsize = MIN(realsize, s->buf_len - s->buf_off);
 202     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 203     s->buf_off += realsize;
 204
 205     for(i=0; i<CURL_NUM_ACB; i++) {
 206         CURLAIOCB *acb = s->acb[i];
 207
 208         if (!acb)
 209             continue;
 210
 211         if ((s->buf_off >= acb->end)) {
 212             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
 213                                 acb->end - acb->start);
 214             acb->common.cb(acb->common.opaque, 0);
 215             qemu_aio_release(acb);
 216             s->acb[i] = NULL;
 217         }
 218     }
 219
 220     return realsize;
 221 }
 222
 223 static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len,
 224                          CURLAIOCB *acb)
 225 {
 226     int i;
 227     size_t end = start + len;
 228
 229     for (i=0; i<CURL_NUM_STATES; i++) {
 230         CURLState *state = &s->states[i];
 231         size_t buf_end = (state->buf_start + state->buf_off);
 232         size_t buf_fend = (state->buf_start + state->buf_len);
 233
 234         if (!state->orig_buf)
 235             continue;
 236         if (!state->buf_off)
 237             continue;
 238
 239         // Does the existing buffer cover our section?
 240         if ((start >= state->buf_start) &&
 241             (start <= buf_end) &&
 242             (end >= state->buf_start) &&
 243             (end <= buf_end))
 244         {
 245             char *buf = state->orig_buf + (start - state->buf_start);
 246
 247             qemu_iovec_from_buf(acb->qiov, 0, buf, len);
 248             acb->common.cb(acb->common.opaque, 0);
 249
 250             return FIND_RET_OK;
 251         }
 252
 253         // Wait for unfinished chunks
 254         if (state->in_use &&
 255             (start >= state->buf_start) &&
 256             (start <= buf_fend) &&
 257             (end >= state->buf_start) &&
 258             (end <= buf_fend))
 259         {
 260             int j;
 261
 262             acb->start = start - state->buf_start;
 263             acb->end = acb->start + len;
 264
 265             for (j=0; j<CURL_NUM_ACB; j++) {
 266                 if (!state->acb[j]) {
 267                     state->acb[j] = acb;
 268                     return FIND_RET_WAIT;
 269                 }
 270             }
 271         }
 272     }
 273
 274     return FIND_RET_NONE;
 275 }
 276
 277 static void curl_multi_check_completion(BDRVCURLState *s)
 278 {
 279     int msgs_in_queue;
 280
 281     /* Try to find done transfers, so we can free the easy
 282      * handle again. */
 283     for (;;) {
 284         CURLMsg *msg;
 285         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 286
 287         /* Quit when there are no more completions */
 288         if (!msg)
 289             break;
 290
 291         if (msg->msg == CURLMSG_DONE) {
 292             CURLState *state = NULL;
 293             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 294                               (char **)&state);
 295
 296             /* ACBs for successful messages get completed in curl_read_cb */
 297             if (msg->data.result != CURLE_OK) {
 298                 int i;
 299                 for (i = 0; i < CURL_NUM_ACB; i++) {
 300                     CURLAIOCB *acb = state->acb[i];
 301
 302                     if (acb == NULL) {
 303                         continue;
 304                     }
 305
 306                     acb->common.cb(acb->common.opaque, -EIO);
 307                     qemu_aio_release(acb);
 308                     state->acb[i] = NULL;
 309                 }
 310             }
 311
 312             curl_clean_state(state);
 313             break;
 314         }
 315     }
 316 }
 317
 318 static void curl_multi_do(void *arg)
 319 {
 320     CURLState *s = (CURLState *)arg;
 321     int running;
 322     int r;
 323
 324     if (!s->s->multi) {
 325         return;
 326     }
 327
 328     do {
 329         r = curl_multi_socket_action(s->s->multi, s->sock_fd, 0, &running);
 330     } while(r == CURLM_CALL_MULTI_PERFORM);
 331
 332 }
 333
 334 static void curl_multi_read(void *arg)
 335 {
 336     CURLState *s = (CURLState *)arg;
 337
 338     curl_multi_do(arg);
 339     curl_multi_check_completion(s->s);
 340 }
 341
 342 static void curl_multi_timeout_do(void *arg)
 343 {
 344 #ifdef NEED_CURL_TIMER_CALLBACK
 345     BDRVCURLState *s = (BDRVCURLState *)arg;
 346     int running;
 347
 348     if (!s->multi) {
 349         return;
 350     }
 351
 352     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 353
 354     curl_multi_check_completion(s);
 355 #else
 356     abort();
 357 #endif
 358 }
 359
 360 static CURLState *curl_init_state(BlockDriverState *bs, BDRVCURLState *s)
 361 {
 362     CURLState *state = NULL;
 363     int i, j;
 364
 365     do {
 366         for (i=0; i<CURL_NUM_STATES; i++) {
 367             for (j=0; j<CURL_NUM_ACB; j++)
 368                 if (s->states[i].acb[j])
 369                     continue;
 370             if (s->states[i].in_use)
 371                 continue;
 372
 373             state = &s->states[i];
 374             state->in_use = 1;
 375             break;
 376         }
 377         if (!state) {
 378             aio_poll(bdrv_get_aio_context(bs), true);
 379         }
 380     } while(!state);
 381
 382     if (!state->curl) {
 383         state->curl = curl_easy_init();
 384         if (!state->curl) {
 385             return NULL;
 386         }
 387         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 388         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 389                          (long) s->sslverify);
 390         if (s->cookie) {
 391             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
 392         }
 393         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, s->timeout);
 394         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 395                          (void *)curl_read_cb);
 396         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 397         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 398         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 399         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 400         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 401         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 402         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 403
 404         /* Restrict supported protocols to avoid security issues in the more
 405          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 406          * CVE-2013-0249.
 407          *
 408          * Restricting protocols is only supported from 7.19.4 upwards.
 409          */
 410 #if LIBCURL_VERSION_NUM >= 0x071304
 411         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 412         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 413 #endif
 414
 415 #ifdef DEBUG_VERBOSE
 416         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 417 #endif
 418     }
 419
 420     state->s = s;
 421
 422     return state;
 423 }
 424
 425 static void curl_clean_state(CURLState *s)
 426 {
 427     if (s->s->multi)
 428         curl_multi_remove_handle(s->s->multi, s->curl);
 429     s->in_use = 0;
 430 }
 431
 432 static void curl_parse_filename(const char *filename, QDict *options,
 433                                 Error **errp)
 434 {
 435     qdict_put(options, CURL_BLOCK_OPT_URL, qstring_from_str(filename));
 436 }
 437
 438 static void curl_detach_aio_context(BlockDriverState *bs)
 439 {
 440     BDRVCURLState *s = bs->opaque;
 441     int i;
 442
 443     for (i = 0; i < CURL_NUM_STATES; i++) {
 444         if (s->states[i].in_use) {
 445             curl_clean_state(&s->states[i]);
 446         }
 447         if (s->states[i].curl) {
 448             curl_easy_cleanup(s->states[i].curl);
 449             s->states[i].curl = NULL;
 450         }
 451         g_free(s->states[i].orig_buf);
 452         s->states[i].orig_buf = NULL;
 453     }
 454     if (s->multi) {
 455         curl_multi_cleanup(s->multi);
 456         s->multi = NULL;
 457     }
 458
 459     timer_del(&s->timer);
 460 }
 461
 462 static void curl_attach_aio_context(BlockDriverState *bs,
 463                                     AioContext *new_context)
 464 {
 465     BDRVCURLState *s = bs->opaque;
 466
 467     aio_timer_init(new_context, &s->timer,
 468                    QEMU_CLOCK_REALTIME, SCALE_NS,
 469                    curl_multi_timeout_do, s);
 470
 471     assert(!s->multi);
 472     s->multi = curl_multi_init();
 473     s->aio_context = new_context;
 474     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 475 #ifdef NEED_CURL_TIMER_CALLBACK
 476     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 477     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 478 #endif
 479 }
 480
 481 static QemuOptsList runtime_opts = {
 482     .name = "curl",
 483     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 484     .desc = {
 485         {
 486             .name = CURL_BLOCK_OPT_URL,
 487             .type = QEMU_OPT_STRING,
 488             .help = "URL to open",
 489         },
 490         {
 491             .name = CURL_BLOCK_OPT_READAHEAD,
 492             .type = QEMU_OPT_SIZE,
 493             .help = "Readahead size",
 494         },
 495         {
 496             .name = CURL_BLOCK_OPT_SSLVERIFY,
 497             .type = QEMU_OPT_BOOL,
 498             .help = "Verify SSL certificate"
 499         },
 500         {
 501             .name = CURL_BLOCK_OPT_TIMEOUT,
 502             .type = QEMU_OPT_NUMBER,
 503             .help = "Curl timeout"
 504         },
 505         {
 506             .name = CURL_BLOCK_OPT_COOKIE,
 507             .type = QEMU_OPT_STRING,
 508             .help = "Pass the cookie or list of cookies with each request"
 509         },
 510         { /* end of list */ }
 511     },
 512 };
 513
 514 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 515                      Error **errp)
 516 {
 517     BDRVCURLState *s = bs->opaque;
 518     CURLState *state = NULL;
 519     QemuOpts *opts;
 520     Error *local_err = NULL;
 521     const char *file;
 522     const char *cookie;
 523     double d;
 524
 525     static int inited = 0;
 526
 527     if (flags & BDRV_O_RDWR) {
 528         error_setg(errp, "curl block device does not support writes");
 529         return -EROFS;
 530     }
 531
 532     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 533     qemu_opts_absorb_qdict(opts, options, &local_err);
 534     if (local_err) {
 535         error_propagate(errp, local_err);
 536         goto out_noclean;
 537     }
 538
 539     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 540                                           READ_AHEAD_DEFAULT);
 541     if ((s->readahead_size & 0x1ff) != 0) {
 542         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 543                    s->readahead_size);
 544         goto out_noclean;
 545     }
 546
 547     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 548                                      CURL_TIMEOUT_DEFAULT);
 549
 550     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
 551
 552     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 553     s->cookie = g_strdup(cookie);
 554
 555     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 556     if (file == NULL) {
 557         error_setg(errp, "curl block driver requires an 'url' option");
 558         goto out_noclean;
 559     }
 560
 561     if (!inited) {
 562         curl_global_init(CURL_GLOBAL_ALL);
 563         inited = 1;
 564     }
 565
 566     DPRINTF("CURL: Opening %s\n", file);
 567     s->aio_context = bdrv_get_aio_context(bs);
 568     s->url = g_strdup(file);
 569     state = curl_init_state(bs, s);
 570     if (!state)
 571         goto out_noclean;
 572
 573     // Get file size
 574
 575     s->accept_range = false;
 576     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 577     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 578                      curl_header_cb);
 579     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 580     if (curl_easy_perform(state->curl))
 581         goto out;
 582     curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d);
 583     if (d)
 584         s->len = (size_t)d;
 585     else if(!s->len)
 586         goto out;
 587     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 588         || !strncasecmp(s->url, "https://", strlen("https://")))
 589         && !s->accept_range) {
 590         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 591                 "Server does not support 'range' (byte ranges).");
 592         goto out;
 593     }
 594     DPRINTF("CURL: Size = %zd\n", s->len);
 595
 596     curl_clean_state(state);
 597     curl_easy_cleanup(state->curl);
 598     state->curl = NULL;
 599
 600     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 601
 602     qemu_opts_del(opts);
 603     return 0;
 604
 605 out:
 606     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 607     curl_easy_cleanup(state->curl);
 608     state->curl = NULL;
 609 out_noclean:
 610     g_free(s->cookie);
 611     g_free(s->url);
 612     qemu_opts_del(opts);
 613     return -EINVAL;
 614 }
 615
 616 static void curl_aio_cancel(BlockDriverAIOCB *blockacb)
 617 {
 618     // Do we have to implement canceling? Seems to work without...
 619 }
 620
 621 static const AIOCBInfo curl_aiocb_info = {
 622     .aiocb_size         = sizeof(CURLAIOCB),
 623     .cancel             = curl_aio_cancel,
 624 };
 625
 626
 627 static void curl_readv_bh_cb(void *p)
 628 {
 629     CURLState *state;
 630     int running;
 631
 632     CURLAIOCB *acb = p;
 633     BDRVCURLState *s = acb->common.bs->opaque;
 634
 635     qemu_bh_delete(acb->bh);
 636     acb->bh = NULL;
 637
 638     size_t start = acb->sector_num * SECTOR_SIZE;
 639     size_t end;
 640
 641     // In case we have the requested data already (e.g. read-ahead),
 642     // we can just call the callback and be done.
 643     switch (curl_find_buf(s, start, acb->nb_sectors * SECTOR_SIZE, acb)) {
 644         case FIND_RET_OK:
 645             qemu_aio_release(acb);
 646             // fall through
 647         case FIND_RET_WAIT:
 648             return;
 649         default:
 650             break;
 651     }
 652
 653     // No cache found, so let's start a new request
 654     state = curl_init_state(acb->common.bs, s);
 655     if (!state) {
 656         acb->common.cb(acb->common.opaque, -EIO);
 657         qemu_aio_release(acb);
 658         return;
 659     }
 660
 661     acb->start = 0;
 662     acb->end = (acb->nb_sectors * SECTOR_SIZE);
 663
 664     state->buf_off = 0;
 665     g_free(state->orig_buf);
 666     state->buf_start = start;
 667     state->buf_len = acb->end + s->readahead_size;
 668     end = MIN(start + state->buf_len, s->len) - 1;
 669     state->orig_buf = g_try_malloc(state->buf_len);
 670     if (state->buf_len && state->orig_buf == NULL) {
 671         curl_clean_state(state);
 672         acb->common.cb(acb->common.opaque, -ENOMEM);
 673         qemu_aio_release(acb);
 674         return;
 675     }
 676     state->acb[0] = acb;
 677
 678     snprintf(state->range, 127, "%zd-%zd", start, end);
 679     DPRINTF("CURL (AIO): Reading %d at %zd (%s)\n",
 680             (acb->nb_sectors * SECTOR_SIZE), start, state->range);
 681     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 682
 683     curl_multi_add_handle(s->multi, state->curl);
 684
 685     /* Tell curl it needs to kick things off */
 686     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 687 }
 688
 689 static BlockDriverAIOCB *curl_aio_readv(BlockDriverState *bs,
 690         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 691         BlockDriverCompletionFunc *cb, void *opaque)
 692 {
 693     CURLAIOCB *acb;
 694
 695     acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque);
 696
 697     acb->qiov = qiov;
 698     acb->sector_num = sector_num;
 699     acb->nb_sectors = nb_sectors;
 700
 701     acb->bh = aio_bh_new(bdrv_get_aio_context(bs), curl_readv_bh_cb, acb);
 702     qemu_bh_schedule(acb->bh);
 703     return &acb->common;
 704 }
 705
 706 static void curl_close(BlockDriverState *bs)
 707 {
 708     BDRVCURLState *s = bs->opaque;
 709
 710     DPRINTF("CURL: Close\n");
 711     curl_detach_aio_context(bs);
 712
 713     g_free(s->cookie);
 714     g_free(s->url);
 715 }
 716
 717 static int64_t curl_getlength(BlockDriverState *bs)
 718 {
 719     BDRVCURLState *s = bs->opaque;
 720     return s->len;
 721 }
 722
 723 static BlockDriver bdrv_http = {
 724     .format_name                = "http",
 725     .protocol_name              = "http",
 726
 727     .instance_size              = sizeof(BDRVCURLState),
 728     .bdrv_parse_filename        = curl_parse_filename,
 729     .bdrv_file_open             = curl_open,
 730     .bdrv_close                 = curl_close,
 731     .bdrv_getlength             = curl_getlength,
 732
 733     .bdrv_aio_readv             = curl_aio_readv,
 734
 735     .bdrv_detach_aio_context    = curl_detach_aio_context,
 736     .bdrv_attach_aio_context    = curl_attach_aio_context,
 737 };
 738
 739 static BlockDriver bdrv_https = {
 740     .format_name                = "https",
 741     .protocol_name              = "https",
 742
 743     .instance_size              = sizeof(BDRVCURLState),
 744     .bdrv_parse_filename        = curl_parse_filename,
 745     .bdrv_file_open             = curl_open,
 746     .bdrv_close                 = curl_close,
 747     .bdrv_getlength             = curl_getlength,
 748
 749     .bdrv_aio_readv             = curl_aio_readv,
 750
 751     .bdrv_detach_aio_context    = curl_detach_aio_context,
 752     .bdrv_attach_aio_context    = curl_attach_aio_context,
 753 };
 754
 755 static BlockDriver bdrv_ftp = {
 756     .format_name                = "ftp",
 757     .protocol_name              = "ftp",
 758
 759     .instance_size              = sizeof(BDRVCURLState),
 760     .bdrv_parse_filename        = curl_parse_filename,
 761     .bdrv_file_open             = curl_open,
 762     .bdrv_close                 = curl_close,
 763     .bdrv_getlength             = curl_getlength,
 764
 765     .bdrv_aio_readv             = curl_aio_readv,
 766
 767     .bdrv_detach_aio_context    = curl_detach_aio_context,
 768     .bdrv_attach_aio_context    = curl_attach_aio_context,
 769 };
 770
 771 static BlockDriver bdrv_ftps = {
 772     .format_name                = "ftps",
 773     .protocol_name              = "ftps",
 774
 775     .instance_size              = sizeof(BDRVCURLState),
 776     .bdrv_parse_filename        = curl_parse_filename,
 777     .bdrv_file_open             = curl_open,
 778     .bdrv_close                 = curl_close,
 779     .bdrv_getlength             = curl_getlength,
 780
 781     .bdrv_aio_readv             = curl_aio_readv,
 782
 783     .bdrv_detach_aio_context    = curl_detach_aio_context,
 784     .bdrv_attach_aio_context    = curl_attach_aio_context,
 785 };
 786
 787 static BlockDriver bdrv_tftp = {
 788     .format_name                = "tftp",
 789     .protocol_name              = "tftp",
 790
 791     .instance_size              = sizeof(BDRVCURLState),
 792     .bdrv_parse_filename        = curl_parse_filename,
 793     .bdrv_file_open             = curl_open,
 794     .bdrv_close                 = curl_close,
 795     .bdrv_getlength             = curl_getlength,
 796
 797     .bdrv_aio_readv             = curl_aio_readv,
 798
 799     .bdrv_detach_aio_context    = curl_detach_aio_context,
 800     .bdrv_attach_aio_context    = curl_attach_aio_context,
 801 };
 802
 803 static void curl_block_init(void)
 804 {
 805     bdrv_register(&bdrv_http);
 806     bdrv_register(&bdrv_https);
 807     bdrv_register(&bdrv_ftp);
 808     bdrv_register(&bdrv_ftps);
 809     bdrv_register(&bdrv_tftp);
 810 }
 811
 812 block_init(curl_block_init);