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/osdep.h"
  25 #include "qemu-common.h"
  26 #include "qemu/error-report.h"
  27 #include "block/block_int.h"
  28 #include "qapi/qmp/qbool.h"
  29 #include "qapi/qmp/qstring.h"
  30 #include "crypto/secret.h"
  31 #include <curl/curl.h>
  32
  33 // #define DEBUG_CURL
  34 // #define DEBUG_VERBOSE
  35
  36 #ifdef DEBUG_CURL
  37 #define DPRINTF(fmt, ...) do { printf(fmt, ## __VA_ARGS__); } while (0)
  38 #else
  39 #define DPRINTF(fmt, ...) do { } while (0)
  40 #endif
  41
  42 #if LIBCURL_VERSION_NUM >= 0x071000
  43 /* The multi interface timer callback was introduced in 7.16.0 */
  44 #define NEED_CURL_TIMER_CALLBACK
  45 #define HAVE_SOCKET_ACTION
  46 #endif
  47
  48 #ifndef HAVE_SOCKET_ACTION
  49 /* If curl_multi_socket_action isn't available, define it statically here in
  50  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
  51  * less efficient but still safe. */
  52 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
  53                                             curl_socket_t sockfd,
  54                                             int ev_bitmask,
  55                                             int *running_handles)
  56 {
  57     return curl_multi_socket(multi_handle, sockfd, running_handles);
  58 }
  59 #define curl_multi_socket_action __curl_multi_socket_action
  60 #endif
  61
  62 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  63                    CURLPROTO_FTP | CURLPROTO_FTPS | \
  64                    CURLPROTO_TFTP)
  65
  66 #define CURL_NUM_STATES 8
  67 #define CURL_NUM_ACB    8
  68 #define SECTOR_SIZE     512
  69 #define READ_AHEAD_DEFAULT (256 * 1024)
  70 #define CURL_TIMEOUT_DEFAULT 5
  71 #define CURL_TIMEOUT_MAX 10000
  72
  73 #define FIND_RET_NONE   0
  74 #define FIND_RET_OK     1
  75 #define FIND_RET_WAIT   2
  76
  77 #define CURL_BLOCK_OPT_URL       "url"
  78 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  79 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  80 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
  81 #define CURL_BLOCK_OPT_COOKIE    "cookie"
  82 #define CURL_BLOCK_OPT_USERNAME "username"
  83 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
  84 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
  85 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
  86
  87 struct BDRVCURLState;
  88
  89 typedef struct CURLAIOCB {
  90     BlockAIOCB common;
  91     QEMUBH *bh;
  92     QEMUIOVector *qiov;
  93
  94     int64_t sector_num;
  95     int nb_sectors;
  96
  97     size_t start;
  98     size_t end;
  99 } CURLAIOCB;
 100
 101 typedef struct CURLState
 102 {
 103     struct BDRVCURLState *s;
 104     CURLAIOCB *acb[CURL_NUM_ACB];
 105     CURL *curl;
 106     curl_socket_t sock_fd;
 107     char *orig_buf;
 108     size_t buf_start;
 109     size_t buf_off;
 110     size_t buf_len;
 111     char range[128];
 112     char errmsg[CURL_ERROR_SIZE];
 113     char in_use;
 114 } CURLState;
 115
 116 typedef struct BDRVCURLState {
 117     CURLM *multi;
 118     QEMUTimer timer;
 119     size_t len;
 120     CURLState states[CURL_NUM_STATES];
 121     char *url;
 122     size_t readahead_size;
 123     bool sslverify;
 124     uint64_t timeout;
 125     char *cookie;
 126     bool accept_range;
 127     AioContext *aio_context;
 128     char *username;
 129     char *password;
 130     char *proxyusername;
 131     char *proxypassword;
 132 } BDRVCURLState;
 133
 134 static void curl_clean_state(CURLState *s);
 135 static void curl_multi_do(void *arg);
 136 static void curl_multi_read(void *arg);
 137
 138 #ifdef NEED_CURL_TIMER_CALLBACK
 139 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 140 {
 141     BDRVCURLState *s = opaque;
 142
 143     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
 144     if (timeout_ms == -1) {
 145         timer_del(&s->timer);
 146     } else {
 147         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 148         timer_mod(&s->timer,
 149                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 150     }
 151     return 0;
 152 }
 153 #endif
 154
 155 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 156                         void *userp, void *sp)
 157 {
 158     BDRVCURLState *s;
 159     CURLState *state = NULL;
 160     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 161     state->sock_fd = fd;
 162     s = state->s;
 163
 164     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, fd);
 165     switch (action) {
 166         case CURL_POLL_IN:
 167             aio_set_fd_handler(s->aio_context, fd, false,
 168                                curl_multi_read, NULL, state);
 169             break;
 170         case CURL_POLL_OUT:
 171             aio_set_fd_handler(s->aio_context, fd, false,
 172                                NULL, curl_multi_do, state);
 173             break;
 174         case CURL_POLL_INOUT:
 175             aio_set_fd_handler(s->aio_context, fd, false,
 176                                curl_multi_read, curl_multi_do, state);
 177             break;
 178         case CURL_POLL_REMOVE:
 179             aio_set_fd_handler(s->aio_context, fd, false,
 180                                NULL, NULL, NULL);
 181             break;
 182     }
 183
 184     return 0;
 185 }
 186
 187 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 188 {
 189     BDRVCURLState *s = opaque;
 190     size_t realsize = size * nmemb;
 191     const char *accept_line = "Accept-Ranges: bytes";
 192
 193     if (realsize >= strlen(accept_line)
 194         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
 195         s->accept_range = true;
 196     }
 197
 198     return realsize;
 199 }
 200
 201 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 202 {
 203     CURLState *s = ((CURLState*)opaque);
 204     size_t realsize = size * nmemb;
 205     int i;
 206
 207     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
 208
 209     if (!s || !s->orig_buf)
 210         return 0;
 211
 212     if (s->buf_off >= s->buf_len) {
 213         /* buffer full, read nothing */
 214         return 0;
 215     }
 216     realsize = MIN(realsize, s->buf_len - s->buf_off);
 217     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 218     s->buf_off += realsize;
 219
 220     for(i=0; i<CURL_NUM_ACB; i++) {
 221         CURLAIOCB *acb = s->acb[i];
 222
 223         if (!acb)
 224             continue;
 225
 226         if ((s->buf_off >= acb->end)) {
 227             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
 228                                 acb->end - acb->start);
 229             acb->common.cb(acb->common.opaque, 0);
 230             qemu_aio_unref(acb);
 231             s->acb[i] = NULL;
 232         }
 233     }
 234
 235     return realsize;
 236 }
 237
 238 static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len,
 239                          CURLAIOCB *acb)
 240 {
 241     int i;
 242     size_t end = start + len;
 243
 244     for (i=0; i<CURL_NUM_STATES; i++) {
 245         CURLState *state = &s->states[i];
 246         size_t buf_end = (state->buf_start + state->buf_off);
 247         size_t buf_fend = (state->buf_start + state->buf_len);
 248
 249         if (!state->orig_buf)
 250             continue;
 251         if (!state->buf_off)
 252             continue;
 253
 254         // Does the existing buffer cover our section?
 255         if ((start >= state->buf_start) &&
 256             (start <= buf_end) &&
 257             (end >= state->buf_start) &&
 258             (end <= buf_end))
 259         {
 260             char *buf = state->orig_buf + (start - state->buf_start);
 261
 262             qemu_iovec_from_buf(acb->qiov, 0, buf, len);
 263             acb->common.cb(acb->common.opaque, 0);
 264
 265             return FIND_RET_OK;
 266         }
 267
 268         // Wait for unfinished chunks
 269         if (state->in_use &&
 270             (start >= state->buf_start) &&
 271             (start <= buf_fend) &&
 272             (end >= state->buf_start) &&
 273             (end <= buf_fend))
 274         {
 275             int j;
 276
 277             acb->start = start - state->buf_start;
 278             acb->end = acb->start + len;
 279
 280             for (j=0; j<CURL_NUM_ACB; j++) {
 281                 if (!state->acb[j]) {
 282                     state->acb[j] = acb;
 283                     return FIND_RET_WAIT;
 284                 }
 285             }
 286         }
 287     }
 288
 289     return FIND_RET_NONE;
 290 }
 291
 292 static void curl_multi_check_completion(BDRVCURLState *s)
 293 {
 294     int msgs_in_queue;
 295
 296     /* Try to find done transfers, so we can free the easy
 297      * handle again. */
 298     for (;;) {
 299         CURLMsg *msg;
 300         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 301
 302         /* Quit when there are no more completions */
 303         if (!msg)
 304             break;
 305
 306         if (msg->msg == CURLMSG_DONE) {
 307             CURLState *state = NULL;
 308             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 309                               (char **)&state);
 310
 311             /* ACBs for successful messages get completed in curl_read_cb */
 312             if (msg->data.result != CURLE_OK) {
 313                 int i;
 314                 static int errcount = 100;
 315
 316                 /* Don't lose the original error message from curl, since
 317                  * it contains extra data.
 318                  */
 319                 if (errcount > 0) {
 320                     error_report("curl: %s", state->errmsg);
 321                     if (--errcount == 0) {
 322                         error_report("curl: further errors suppressed");
 323                     }
 324                 }
 325
 326                 for (i = 0; i < CURL_NUM_ACB; i++) {
 327                     CURLAIOCB *acb = state->acb[i];
 328
 329                     if (acb == NULL) {
 330                         continue;
 331                     }
 332
 333                     acb->common.cb(acb->common.opaque, -EPROTO);
 334                     qemu_aio_unref(acb);
 335                     state->acb[i] = NULL;
 336                 }
 337             }
 338
 339             curl_clean_state(state);
 340             break;
 341         }
 342     }
 343 }
 344
 345 static void curl_multi_do(void *arg)
 346 {
 347     CURLState *s = (CURLState *)arg;
 348     int running;
 349     int r;
 350
 351     if (!s->s->multi) {
 352         return;
 353     }
 354
 355     do {
 356         r = curl_multi_socket_action(s->s->multi, s->sock_fd, 0, &running);
 357     } while(r == CURLM_CALL_MULTI_PERFORM);
 358
 359 }
 360
 361 static void curl_multi_read(void *arg)
 362 {
 363     CURLState *s = (CURLState *)arg;
 364
 365     curl_multi_do(arg);
 366     curl_multi_check_completion(s->s);
 367 }
 368
 369 static void curl_multi_timeout_do(void *arg)
 370 {
 371 #ifdef NEED_CURL_TIMER_CALLBACK
 372     BDRVCURLState *s = (BDRVCURLState *)arg;
 373     int running;
 374
 375     if (!s->multi) {
 376         return;
 377     }
 378
 379     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 380
 381     curl_multi_check_completion(s);
 382 #else
 383     abort();
 384 #endif
 385 }
 386
 387 static CURLState *curl_init_state(BlockDriverState *bs, BDRVCURLState *s)
 388 {
 389     CURLState *state = NULL;
 390     int i, j;
 391
 392     do {
 393         for (i=0; i<CURL_NUM_STATES; i++) {
 394             for (j=0; j<CURL_NUM_ACB; j++)
 395                 if (s->states[i].acb[j])
 396                     continue;
 397             if (s->states[i].in_use)
 398                 continue;
 399
 400             state = &s->states[i];
 401             state->in_use = 1;
 402             break;
 403         }
 404         if (!state) {
 405             aio_poll(bdrv_get_aio_context(bs), true);
 406         }
 407     } while(!state);
 408
 409     if (!state->curl) {
 410         state->curl = curl_easy_init();
 411         if (!state->curl) {
 412             return NULL;
 413         }
 414         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 415         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 416                          (long) s->sslverify);
 417         if (s->cookie) {
 418             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
 419         }
 420         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
 421         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 422                          (void *)curl_read_cb);
 423         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 424         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 425         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 426         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 427         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 428         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 429         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 430
 431         if (s->username) {
 432             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
 433         }
 434         if (s->password) {
 435             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
 436         }
 437         if (s->proxyusername) {
 438             curl_easy_setopt(state->curl,
 439                              CURLOPT_PROXYUSERNAME, s->proxyusername);
 440         }
 441         if (s->proxypassword) {
 442             curl_easy_setopt(state->curl,
 443                              CURLOPT_PROXYPASSWORD, s->proxypassword);
 444         }
 445
 446         /* Restrict supported protocols to avoid security issues in the more
 447          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 448          * CVE-2013-0249.
 449          *
 450          * Restricting protocols is only supported from 7.19.4 upwards.
 451          */
 452 #if LIBCURL_VERSION_NUM >= 0x071304
 453         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 454         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 455 #endif
 456
 457 #ifdef DEBUG_VERBOSE
 458         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 459 #endif
 460     }
 461
 462     state->s = s;
 463
 464     return state;
 465 }
 466
 467 static void curl_clean_state(CURLState *s)
 468 {
 469     if (s->s->multi)
 470         curl_multi_remove_handle(s->s->multi, s->curl);
 471     s->in_use = 0;
 472 }
 473
 474 static void curl_parse_filename(const char *filename, QDict *options,
 475                                 Error **errp)
 476 {
 477     qdict_put(options, CURL_BLOCK_OPT_URL, qstring_from_str(filename));
 478 }
 479
 480 static void curl_detach_aio_context(BlockDriverState *bs)
 481 {
 482     BDRVCURLState *s = bs->opaque;
 483     int i;
 484
 485     for (i = 0; i < CURL_NUM_STATES; i++) {
 486         if (s->states[i].in_use) {
 487             curl_clean_state(&s->states[i]);
 488         }
 489         if (s->states[i].curl) {
 490             curl_easy_cleanup(s->states[i].curl);
 491             s->states[i].curl = NULL;
 492         }
 493         g_free(s->states[i].orig_buf);
 494         s->states[i].orig_buf = NULL;
 495     }
 496     if (s->multi) {
 497         curl_multi_cleanup(s->multi);
 498         s->multi = NULL;
 499     }
 500
 501     timer_del(&s->timer);
 502 }
 503
 504 static void curl_attach_aio_context(BlockDriverState *bs,
 505                                     AioContext *new_context)
 506 {
 507     BDRVCURLState *s = bs->opaque;
 508
 509     aio_timer_init(new_context, &s->timer,
 510                    QEMU_CLOCK_REALTIME, SCALE_NS,
 511                    curl_multi_timeout_do, s);
 512
 513     assert(!s->multi);
 514     s->multi = curl_multi_init();
 515     s->aio_context = new_context;
 516     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 517 #ifdef NEED_CURL_TIMER_CALLBACK
 518     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 519     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 520 #endif
 521 }
 522
 523 static QemuOptsList runtime_opts = {
 524     .name = "curl",
 525     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 526     .desc = {
 527         {
 528             .name = CURL_BLOCK_OPT_URL,
 529             .type = QEMU_OPT_STRING,
 530             .help = "URL to open",
 531         },
 532         {
 533             .name = CURL_BLOCK_OPT_READAHEAD,
 534             .type = QEMU_OPT_SIZE,
 535             .help = "Readahead size",
 536         },
 537         {
 538             .name = CURL_BLOCK_OPT_SSLVERIFY,
 539             .type = QEMU_OPT_BOOL,
 540             .help = "Verify SSL certificate"
 541         },
 542         {
 543             .name = CURL_BLOCK_OPT_TIMEOUT,
 544             .type = QEMU_OPT_NUMBER,
 545             .help = "Curl timeout"
 546         },
 547         {
 548             .name = CURL_BLOCK_OPT_COOKIE,
 549             .type = QEMU_OPT_STRING,
 550             .help = "Pass the cookie or list of cookies with each request"
 551         },
 552         {
 553             .name = CURL_BLOCK_OPT_USERNAME,
 554             .type = QEMU_OPT_STRING,
 555             .help = "Username for HTTP auth"
 556         },
 557         {
 558             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 559             .type = QEMU_OPT_STRING,
 560             .help = "ID of secret used as password for HTTP auth",
 561         },
 562         {
 563             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 564             .type = QEMU_OPT_STRING,
 565             .help = "Username for HTTP proxy auth"
 566         },
 567         {
 568             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 569             .type = QEMU_OPT_STRING,
 570             .help = "ID of secret used as password for HTTP proxy auth",
 571         },
 572         { /* end of list */ }
 573     },
 574 };
 575
 576
 577 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 578                      Error **errp)
 579 {
 580     BDRVCURLState *s = bs->opaque;
 581     CURLState *state = NULL;
 582     QemuOpts *opts;
 583     Error *local_err = NULL;
 584     const char *file;
 585     const char *cookie;
 586     double d;
 587     const char *secretid;
 588
 589     static int inited = 0;
 590
 591     if (flags & BDRV_O_RDWR) {
 592         error_setg(errp, "curl block device does not support writes");
 593         return -EROFS;
 594     }
 595
 596     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 597     qemu_opts_absorb_qdict(opts, options, &local_err);
 598     if (local_err) {
 599         error_propagate(errp, local_err);
 600         goto out_noclean;
 601     }
 602
 603     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 604                                           READ_AHEAD_DEFAULT);
 605     if ((s->readahead_size & 0x1ff) != 0) {
 606         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 607                    s->readahead_size);
 608         goto out_noclean;
 609     }
 610
 611     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 612                                      CURL_TIMEOUT_DEFAULT);
 613     if (s->timeout > CURL_TIMEOUT_MAX) {
 614         error_setg(errp, "timeout parameter is too large or negative");
 615         goto out_noclean;
 616     }
 617
 618     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
 619
 620     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 621     s->cookie = g_strdup(cookie);
 622
 623     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 624     if (file == NULL) {
 625         error_setg(errp, "curl block driver requires an 'url' option");
 626         goto out_noclean;
 627     }
 628
 629     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 630     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 631
 632     if (secretid) {
 633         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 634         if (!s->password) {
 635             goto out_noclean;
 636         }
 637     }
 638
 639     s->proxyusername = g_strdup(
 640         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 641     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 642     if (secretid) {
 643         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 644         if (!s->proxypassword) {
 645             goto out_noclean;
 646         }
 647     }
 648
 649     if (!inited) {
 650         curl_global_init(CURL_GLOBAL_ALL);
 651         inited = 1;
 652     }
 653
 654     DPRINTF("CURL: Opening %s\n", file);
 655     s->aio_context = bdrv_get_aio_context(bs);
 656     s->url = g_strdup(file);
 657     state = curl_init_state(bs, s);
 658     if (!state)
 659         goto out_noclean;
 660
 661     // Get file size
 662
 663     s->accept_range = false;
 664     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 665     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 666                      curl_header_cb);
 667     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 668     if (curl_easy_perform(state->curl))
 669         goto out;
 670     curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d);
 671     if (d)
 672         s->len = (size_t)d;
 673     else if(!s->len)
 674         goto out;
 675     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 676         || !strncasecmp(s->url, "https://", strlen("https://")))
 677         && !s->accept_range) {
 678         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 679                 "Server does not support 'range' (byte ranges).");
 680         goto out;
 681     }
 682     DPRINTF("CURL: Size = %zd\n", s->len);
 683
 684     curl_clean_state(state);
 685     curl_easy_cleanup(state->curl);
 686     state->curl = NULL;
 687
 688     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 689
 690     qemu_opts_del(opts);
 691     return 0;
 692
 693 out:
 694     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 695     curl_easy_cleanup(state->curl);
 696     state->curl = NULL;
 697 out_noclean:
 698     g_free(s->cookie);
 699     g_free(s->url);
 700     qemu_opts_del(opts);
 701     return -EINVAL;
 702 }
 703
 704 static const AIOCBInfo curl_aiocb_info = {
 705     .aiocb_size         = sizeof(CURLAIOCB),
 706 };
 707
 708
 709 static void curl_readv_bh_cb(void *p)
 710 {
 711     CURLState *state;
 712     int running;
 713
 714     CURLAIOCB *acb = p;
 715     BDRVCURLState *s = acb->common.bs->opaque;
 716
 717     qemu_bh_delete(acb->bh);
 718     acb->bh = NULL;
 719
 720     size_t start = acb->sector_num * SECTOR_SIZE;
 721     size_t end;
 722
 723     // In case we have the requested data already (e.g. read-ahead),
 724     // we can just call the callback and be done.
 725     switch (curl_find_buf(s, start, acb->nb_sectors * SECTOR_SIZE, acb)) {
 726         case FIND_RET_OK:
 727             qemu_aio_unref(acb);
 728             // fall through
 729         case FIND_RET_WAIT:
 730             return;
 731         default:
 732             break;
 733     }
 734
 735     // No cache found, so let's start a new request
 736     state = curl_init_state(acb->common.bs, s);
 737     if (!state) {
 738         acb->common.cb(acb->common.opaque, -EIO);
 739         qemu_aio_unref(acb);
 740         return;
 741     }
 742
 743     acb->start = 0;
 744     acb->end = (acb->nb_sectors * SECTOR_SIZE);
 745
 746     state->buf_off = 0;
 747     g_free(state->orig_buf);
 748     state->buf_start = start;
 749     state->buf_len = acb->end + s->readahead_size;
 750     end = MIN(start + state->buf_len, s->len) - 1;
 751     state->orig_buf = g_try_malloc(state->buf_len);
 752     if (state->buf_len && state->orig_buf == NULL) {
 753         curl_clean_state(state);
 754         acb->common.cb(acb->common.opaque, -ENOMEM);
 755         qemu_aio_unref(acb);
 756         return;
 757     }
 758     state->acb[0] = acb;
 759
 760     snprintf(state->range, 127, "%zd-%zd", start, end);
 761     DPRINTF("CURL (AIO): Reading %d at %zd (%s)\n",
 762             (acb->nb_sectors * SECTOR_SIZE), start, state->range);
 763     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 764
 765     curl_multi_add_handle(s->multi, state->curl);
 766
 767     /* Tell curl it needs to kick things off */
 768     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 769 }
 770
 771 static BlockAIOCB *curl_aio_readv(BlockDriverState *bs,
 772         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 773         BlockCompletionFunc *cb, void *opaque)
 774 {
 775     CURLAIOCB *acb;
 776
 777     acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque);
 778
 779     acb->qiov = qiov;
 780     acb->sector_num = sector_num;
 781     acb->nb_sectors = nb_sectors;
 782
 783     acb->bh = aio_bh_new(bdrv_get_aio_context(bs), curl_readv_bh_cb, acb);
 784     qemu_bh_schedule(acb->bh);
 785     return &acb->common;
 786 }
 787
 788 static void curl_close(BlockDriverState *bs)
 789 {
 790     BDRVCURLState *s = bs->opaque;
 791
 792     DPRINTF("CURL: Close\n");
 793     curl_detach_aio_context(bs);
 794
 795     g_free(s->cookie);
 796     g_free(s->url);
 797 }
 798
 799 static int64_t curl_getlength(BlockDriverState *bs)
 800 {
 801     BDRVCURLState *s = bs->opaque;
 802     return s->len;
 803 }
 804
 805 static BlockDriver bdrv_http = {
 806     .format_name                = "http",
 807     .protocol_name              = "http",
 808
 809     .instance_size              = sizeof(BDRVCURLState),
 810     .bdrv_parse_filename        = curl_parse_filename,
 811     .bdrv_file_open             = curl_open,
 812     .bdrv_close                 = curl_close,
 813     .bdrv_getlength             = curl_getlength,
 814
 815     .bdrv_aio_readv             = curl_aio_readv,
 816
 817     .bdrv_detach_aio_context    = curl_detach_aio_context,
 818     .bdrv_attach_aio_context    = curl_attach_aio_context,
 819 };
 820
 821 static BlockDriver bdrv_https = {
 822     .format_name                = "https",
 823     .protocol_name              = "https",
 824
 825     .instance_size              = sizeof(BDRVCURLState),
 826     .bdrv_parse_filename        = curl_parse_filename,
 827     .bdrv_file_open             = curl_open,
 828     .bdrv_close                 = curl_close,
 829     .bdrv_getlength             = curl_getlength,
 830
 831     .bdrv_aio_readv             = curl_aio_readv,
 832
 833     .bdrv_detach_aio_context    = curl_detach_aio_context,
 834     .bdrv_attach_aio_context    = curl_attach_aio_context,
 835 };
 836
 837 static BlockDriver bdrv_ftp = {
 838     .format_name                = "ftp",
 839     .protocol_name              = "ftp",
 840
 841     .instance_size              = sizeof(BDRVCURLState),
 842     .bdrv_parse_filename        = curl_parse_filename,
 843     .bdrv_file_open             = curl_open,
 844     .bdrv_close                 = curl_close,
 845     .bdrv_getlength             = curl_getlength,
 846
 847     .bdrv_aio_readv             = curl_aio_readv,
 848
 849     .bdrv_detach_aio_context    = curl_detach_aio_context,
 850     .bdrv_attach_aio_context    = curl_attach_aio_context,
 851 };
 852
 853 static BlockDriver bdrv_ftps = {
 854     .format_name                = "ftps",
 855     .protocol_name              = "ftps",
 856
 857     .instance_size              = sizeof(BDRVCURLState),
 858     .bdrv_parse_filename        = curl_parse_filename,
 859     .bdrv_file_open             = curl_open,
 860     .bdrv_close                 = curl_close,
 861     .bdrv_getlength             = curl_getlength,
 862
 863     .bdrv_aio_readv             = curl_aio_readv,
 864
 865     .bdrv_detach_aio_context    = curl_detach_aio_context,
 866     .bdrv_attach_aio_context    = curl_attach_aio_context,
 867 };
 868
 869 static BlockDriver bdrv_tftp = {
 870     .format_name                = "tftp",
 871     .protocol_name              = "tftp",
 872
 873     .instance_size              = sizeof(BDRVCURLState),
 874     .bdrv_parse_filename        = curl_parse_filename,
 875     .bdrv_file_open             = curl_open,
 876     .bdrv_close                 = curl_close,
 877     .bdrv_getlength             = curl_getlength,
 878
 879     .bdrv_aio_readv             = curl_aio_readv,
 880
 881     .bdrv_detach_aio_context    = curl_detach_aio_context,
 882     .bdrv_attach_aio_context    = curl_attach_aio_context,
 883 };
 884
 885 static void curl_block_init(void)
 886 {
 887     bdrv_register(&bdrv_http);
 888     bdrv_register(&bdrv_https);
 889     bdrv_register(&bdrv_ftp);
 890     bdrv_register(&bdrv_ftps);
 891     bdrv_register(&bdrv_tftp);
 892 }
 893
 894 block_init(curl_block_init);