qemu/block/curl.c
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   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. */
  50static 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
  81struct BDRVCURLState;
  82
  83typedef 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
  95typedef 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
 110typedef 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
 124static void curl_clean_state(CURLState *s);
 125static void curl_multi_do(void *arg);
 126static void curl_multi_read(void *arg);
 127
 128#ifdef NEED_CURL_TIMER_CALLBACK
 129static 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
 145static 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
 177static 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
 191static 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
 228static 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
 282static 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
 335static 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
 351static 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
 359static 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
 377static 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
 442static 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
 449static 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
 455static 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
 479static 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
 498static 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
 531static 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
 626out:
 627    error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 628    curl_easy_cleanup(state->curl);
 629    state->curl = NULL;
 630out_noclean:
 631    g_free(s->cookie);
 632    g_free(s->url);
 633    qemu_opts_del(opts);
 634    return -EINVAL;
 635}
 636
 637static const AIOCBInfo curl_aiocb_info = {
 638    .aiocb_size         = sizeof(CURLAIOCB),
 639};
 640
 641
 642static 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
 704static 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
 721static 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
 732static int64_t curl_getlength(BlockDriverState *bs)
 733{
 734    BDRVCURLState *s = bs->opaque;
 735    return s->len;
 736}
 737
 738static 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
 754static 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
 770static 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
 786static 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
 802static 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
 818static 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
 827block_init(curl_block_init);
 828