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