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
  25 #include "qemu/osdep.h"
  26 #include "qapi/error.h"
  27 #include "qemu/error-report.h"
  28 #include "qemu/module.h"
  29 #include "qemu/option.h"
  30 #include "block/block_int.h"
  31 #include "qapi/qmp/qdict.h"
  32 #include "qapi/qmp/qstring.h"
  33 #include "crypto/secret.h"
  34 #include <curl/curl.h>
  35 #include "qemu/cutils.h"
  36 #include "trace.h"
  37
  38 // #define DEBUG_VERBOSE
  39
  40 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  41                    CURLPROTO_FTP | CURLPROTO_FTPS)
  42
  43 #define CURL_NUM_STATES 8
  44 #define CURL_NUM_ACB    8
  45 #define CURL_TIMEOUT_MAX 10000
  46
  47 #define CURL_BLOCK_OPT_URL       "url"
  48 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  49 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  50 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
  51 #define CURL_BLOCK_OPT_COOKIE    "cookie"
  52 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
  53 #define CURL_BLOCK_OPT_USERNAME "username"
  54 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
  55 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
  56 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
  57
  58 #define CURL_BLOCK_OPT_READAHEAD_DEFAULT (256 * 1024)
  59 #define CURL_BLOCK_OPT_SSLVERIFY_DEFAULT true
  60 #define CURL_BLOCK_OPT_TIMEOUT_DEFAULT 5
  61
  62 struct BDRVCURLState;
  63 struct CURLState;
  64
  65 static bool libcurl_initialized;
  66
  67 typedef struct CURLAIOCB {
  68     Coroutine *co;
  69     QEMUIOVector *qiov;
  70
  71     uint64_t offset;
  72     uint64_t bytes;
  73     int ret;
  74
  75     size_t start;
  76     size_t end;
  77 } CURLAIOCB;
  78
  79 typedef struct CURLSocket {
  80     int fd;
  81     struct CURLState *state;
  82     QLIST_ENTRY(CURLSocket) next;
  83 } CURLSocket;
  84
  85 typedef struct CURLState
  86 {
  87     struct BDRVCURLState *s;
  88     CURLAIOCB *acb[CURL_NUM_ACB];
  89     CURL *curl;
  90     QLIST_HEAD(, CURLSocket) sockets;
  91     char *orig_buf;
  92     uint64_t buf_start;
  93     size_t buf_off;
  94     size_t buf_len;
  95     char range[128];
  96     char errmsg[CURL_ERROR_SIZE];
  97     char in_use;
  98 } CURLState;
  99
 100 typedef struct BDRVCURLState {
 101     CURLM *multi;
 102     QEMUTimer timer;
 103     uint64_t len;
 104     CURLState states[CURL_NUM_STATES];
 105     char *url;
 106     size_t readahead_size;
 107     bool sslverify;
 108     uint64_t timeout;
 109     char *cookie;
 110     bool accept_range;
 111     AioContext *aio_context;
 112     QemuMutex mutex;
 113     CoQueue free_state_waitq;
 114     char *username;
 115     char *password;
 116     char *proxyusername;
 117     char *proxypassword;
 118 } BDRVCURLState;
 119
 120 static void curl_clean_state(CURLState *s);
 121 static void curl_multi_do(void *arg);
 122
 123 /* Called from curl_multi_do_locked, with s->mutex held.  */
 124 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 125 {
 126     BDRVCURLState *s = opaque;
 127
 128     trace_curl_timer_cb(timeout_ms);
 129     if (timeout_ms == -1) {
 130         timer_del(&s->timer);
 131     } else {
 132         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 133         timer_mod(&s->timer,
 134                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 135     }
 136     return 0;
 137 }
 138
 139 /* Called from curl_multi_do_locked, with s->mutex held.  */
 140 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 141                         void *userp, void *sp)
 142 {
 143     BDRVCURLState *s;
 144     CURLState *state = NULL;
 145     CURLSocket *socket;
 146
 147     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 148     s = state->s;
 149
 150     QLIST_FOREACH(socket, &state->sockets, next) {
 151         if (socket->fd == fd) {
 152             break;
 153         }
 154     }
 155     if (!socket) {
 156         socket = g_new0(CURLSocket, 1);
 157         socket->fd = fd;
 158         socket->state = state;
 159         QLIST_INSERT_HEAD(&state->sockets, socket, next);
 160     }
 161
 162     trace_curl_sock_cb(action, (int)fd);
 163     switch (action) {
 164         case CURL_POLL_IN:
 165             aio_set_fd_handler(s->aio_context, fd, false,
 166                                curl_multi_do, NULL, NULL, socket);
 167             break;
 168         case CURL_POLL_OUT:
 169             aio_set_fd_handler(s->aio_context, fd, false,
 170                                NULL, curl_multi_do, NULL, socket);
 171             break;
 172         case CURL_POLL_INOUT:
 173             aio_set_fd_handler(s->aio_context, fd, false,
 174                                curl_multi_do, curl_multi_do, NULL, socket);
 175             break;
 176         case CURL_POLL_REMOVE:
 177             aio_set_fd_handler(s->aio_context, fd, false,
 178                                NULL, NULL, NULL, NULL);
 179             break;
 180     }
 181
 182     if (action == CURL_POLL_REMOVE) {
 183         QLIST_REMOVE(socket, next);
 184         g_free(socket);
 185     }
 186
 187     return 0;
 188 }
 189
 190 /* Called from curl_multi_do_locked, with s->mutex held.  */
 191 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 192 {
 193     BDRVCURLState *s = opaque;
 194     size_t realsize = size * nmemb;
 195     const char *header = (char *)ptr;
 196     const char *end = header + realsize;
 197     const char *accept_ranges = "accept-ranges:";
 198     const char *bytes = "bytes";
 199
 200     if (realsize >= strlen(accept_ranges)
 201         && g_ascii_strncasecmp(header, accept_ranges,
 202                                strlen(accept_ranges)) == 0) {
 203
 204         char *p = strchr(header, ':') + 1;
 205
 206         /* Skip whitespace between the header name and value. */
 207         while (p < end && *p && g_ascii_isspace(*p)) {
 208             p++;
 209         }
 210
 211         if (end - p >= strlen(bytes)
 212             && strncmp(p, bytes, strlen(bytes)) == 0) {
 213
 214             /* Check that there is nothing but whitespace after the value. */
 215             p += strlen(bytes);
 216             while (p < end && *p && g_ascii_isspace(*p)) {
 217                 p++;
 218             }
 219
 220             if (p == end || !*p) {
 221                 s->accept_range = true;
 222             }
 223         }
 224     }
 225
 226     return realsize;
 227 }
 228
 229 /* Called from curl_multi_do_locked, with s->mutex held.  */
 230 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 231 {
 232     CURLState *s = ((CURLState*)opaque);
 233     size_t realsize = size * nmemb;
 234
 235     trace_curl_read_cb(realsize);
 236
 237     if (!s || !s->orig_buf) {
 238         goto read_end;
 239     }
 240
 241     if (s->buf_off >= s->buf_len) {
 242         /* buffer full, read nothing */
 243         goto read_end;
 244     }
 245     realsize = MIN(realsize, s->buf_len - s->buf_off);
 246     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 247     s->buf_off += realsize;
 248
 249 read_end:
 250     /* curl will error out if we do not return this value */
 251     return size * nmemb;
 252 }
 253
 254 /* Called with s->mutex held.  */
 255 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
 256                           CURLAIOCB *acb)
 257 {
 258     int i;
 259     uint64_t end = start + len;
 260     uint64_t clamped_end = MIN(end, s->len);
 261     uint64_t clamped_len = clamped_end - start;
 262
 263     for (i=0; i<CURL_NUM_STATES; i++) {
 264         CURLState *state = &s->states[i];
 265         uint64_t buf_end = (state->buf_start + state->buf_off);
 266         uint64_t buf_fend = (state->buf_start + state->buf_len);
 267
 268         if (!state->orig_buf)
 269             continue;
 270         if (!state->buf_off)
 271             continue;
 272
 273         // Does the existing buffer cover our section?
 274         if ((start >= state->buf_start) &&
 275             (start <= buf_end) &&
 276             (clamped_end >= state->buf_start) &&
 277             (clamped_end <= buf_end))
 278         {
 279             char *buf = state->orig_buf + (start - state->buf_start);
 280
 281             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
 282             if (clamped_len < len) {
 283                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
 284             }
 285             acb->ret = 0;
 286             return true;
 287         }
 288
 289         // Wait for unfinished chunks
 290         if (state->in_use &&
 291             (start >= state->buf_start) &&
 292             (start <= buf_fend) &&
 293             (clamped_end >= state->buf_start) &&
 294             (clamped_end <= buf_fend))
 295         {
 296             int j;
 297
 298             acb->start = start - state->buf_start;
 299             acb->end = acb->start + clamped_len;
 300
 301             for (j=0; j<CURL_NUM_ACB; j++) {
 302                 if (!state->acb[j]) {
 303                     state->acb[j] = acb;
 304                     return true;
 305                 }
 306             }
 307         }
 308     }
 309
 310     return false;
 311 }
 312
 313 /* Called with s->mutex held.  */
 314 static void curl_multi_check_completion(BDRVCURLState *s)
 315 {
 316     int msgs_in_queue;
 317
 318     /* Try to find done transfers, so we can free the easy
 319      * handle again. */
 320     for (;;) {
 321         CURLMsg *msg;
 322         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 323
 324         /* Quit when there are no more completions */
 325         if (!msg)
 326             break;
 327
 328         if (msg->msg == CURLMSG_DONE) {
 329             int i;
 330             CURLState *state = NULL;
 331             bool error = msg->data.result != CURLE_OK;
 332
 333             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 334                               (char **)&state);
 335
 336             if (error) {
 337                 static int errcount = 100;
 338
 339                 /* Don't lose the original error message from curl, since
 340                  * it contains extra data.
 341                  */
 342                 if (errcount > 0) {
 343                     error_report("curl: %s", state->errmsg);
 344                     if (--errcount == 0) {
 345                         error_report("curl: further errors suppressed");
 346                     }
 347                 }
 348             }
 349
 350             for (i = 0; i < CURL_NUM_ACB; i++) {
 351                 CURLAIOCB *acb = state->acb[i];
 352
 353                 if (acb == NULL) {
 354                     continue;
 355                 }
 356
 357                 if (!error) {
 358                     /* Assert that we have read all data */
 359                     assert(state->buf_off >= acb->end);
 360
 361                     qemu_iovec_from_buf(acb->qiov, 0,
 362                                         state->orig_buf + acb->start,
 363                                         acb->end - acb->start);
 364
 365                     if (acb->end - acb->start < acb->bytes) {
 366                         size_t offset = acb->end - acb->start;
 367                         qemu_iovec_memset(acb->qiov, offset, 0,
 368                                           acb->bytes - offset);
 369                     }
 370                 }
 371
 372                 acb->ret = error ? -EIO : 0;
 373                 state->acb[i] = NULL;
 374                 qemu_mutex_unlock(&s->mutex);
 375                 aio_co_wake(acb->co);
 376                 qemu_mutex_lock(&s->mutex);
 377             }
 378
 379             curl_clean_state(state);
 380             break;
 381         }
 382     }
 383 }
 384
 385 /* Called with s->mutex held.  */
 386 static void curl_multi_do_locked(CURLSocket *socket)
 387 {
 388     BDRVCURLState *s = socket->state->s;
 389     int running;
 390     int r;
 391
 392     if (!s->multi) {
 393         return;
 394     }
 395
 396     do {
 397         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
 398     } while (r == CURLM_CALL_MULTI_PERFORM);
 399 }
 400
 401 static void curl_multi_do(void *arg)
 402 {
 403     CURLSocket *socket = arg;
 404     BDRVCURLState *s = socket->state->s;
 405
 406     qemu_mutex_lock(&s->mutex);
 407     curl_multi_do_locked(socket);
 408     curl_multi_check_completion(s);
 409     qemu_mutex_unlock(&s->mutex);
 410 }
 411
 412 static void curl_multi_timeout_do(void *arg)
 413 {
 414     BDRVCURLState *s = (BDRVCURLState *)arg;
 415     int running;
 416
 417     if (!s->multi) {
 418         return;
 419     }
 420
 421     qemu_mutex_lock(&s->mutex);
 422     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 423
 424     curl_multi_check_completion(s);
 425     qemu_mutex_unlock(&s->mutex);
 426 }
 427
 428 /* Called with s->mutex held.  */
 429 static CURLState *curl_find_state(BDRVCURLState *s)
 430 {
 431     CURLState *state = NULL;
 432     int i;
 433
 434     for (i = 0; i < CURL_NUM_STATES; i++) {
 435         if (!s->states[i].in_use) {
 436             state = &s->states[i];
 437             state->in_use = 1;
 438             break;
 439         }
 440     }
 441     return state;
 442 }
 443
 444 static int curl_init_state(BDRVCURLState *s, CURLState *state)
 445 {
 446     if (!state->curl) {
 447         state->curl = curl_easy_init();
 448         if (!state->curl) {
 449             return -EIO;
 450         }
 451         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 452         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 453                          (long) s->sslverify);
 454         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
 455                          s->sslverify ? 2L : 0L);
 456         if (s->cookie) {
 457             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
 458         }
 459         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
 460         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 461                          (void *)curl_read_cb);
 462         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 463         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 464         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 465         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 466         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 467         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 468         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 469
 470         if (s->username) {
 471             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
 472         }
 473         if (s->password) {
 474             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
 475         }
 476         if (s->proxyusername) {
 477             curl_easy_setopt(state->curl,
 478                              CURLOPT_PROXYUSERNAME, s->proxyusername);
 479         }
 480         if (s->proxypassword) {
 481             curl_easy_setopt(state->curl,
 482                              CURLOPT_PROXYPASSWORD, s->proxypassword);
 483         }
 484
 485         /* Restrict supported protocols to avoid security issues in the more
 486          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 487          * CVE-2013-0249.
 488          *
 489          * Restricting protocols is only supported from 7.19.4 upwards.
 490          */
 491 #if LIBCURL_VERSION_NUM >= 0x071304
 492         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 493         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 494 #endif
 495
 496 #ifdef DEBUG_VERBOSE
 497         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 498 #endif
 499     }
 500
 501     QLIST_INIT(&state->sockets);
 502     state->s = s;
 503
 504     return 0;
 505 }
 506
 507 /* Called with s->mutex held.  */
 508 static void curl_clean_state(CURLState *s)
 509 {
 510     int j;
 511     for (j = 0; j < CURL_NUM_ACB; j++) {
 512         assert(!s->acb[j]);
 513     }
 514
 515     if (s->s->multi)
 516         curl_multi_remove_handle(s->s->multi, s->curl);
 517
 518     while (!QLIST_EMPTY(&s->sockets)) {
 519         CURLSocket *socket = QLIST_FIRST(&s->sockets);
 520
 521         QLIST_REMOVE(socket, next);
 522         g_free(socket);
 523     }
 524
 525     s->in_use = 0;
 526
 527     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
 528 }
 529
 530 static void curl_parse_filename(const char *filename, QDict *options,
 531                                 Error **errp)
 532 {
 533     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
 534 }
 535
 536 static void curl_detach_aio_context(BlockDriverState *bs)
 537 {
 538     BDRVCURLState *s = bs->opaque;
 539     int i;
 540
 541     WITH_QEMU_LOCK_GUARD(&s->mutex) {
 542         for (i = 0; i < CURL_NUM_STATES; i++) {
 543             if (s->states[i].in_use) {
 544                 curl_clean_state(&s->states[i]);
 545             }
 546             if (s->states[i].curl) {
 547                 curl_easy_cleanup(s->states[i].curl);
 548                 s->states[i].curl = NULL;
 549             }
 550             g_free(s->states[i].orig_buf);
 551             s->states[i].orig_buf = NULL;
 552         }
 553         if (s->multi) {
 554             curl_multi_cleanup(s->multi);
 555             s->multi = NULL;
 556         }
 557     }
 558
 559     timer_del(&s->timer);
 560 }
 561
 562 static void curl_attach_aio_context(BlockDriverState *bs,
 563                                     AioContext *new_context)
 564 {
 565     BDRVCURLState *s = bs->opaque;
 566
 567     aio_timer_init(new_context, &s->timer,
 568                    QEMU_CLOCK_REALTIME, SCALE_NS,
 569                    curl_multi_timeout_do, s);
 570
 571     assert(!s->multi);
 572     s->multi = curl_multi_init();
 573     s->aio_context = new_context;
 574     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 575     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 576     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 577 }
 578
 579 static QemuOptsList runtime_opts = {
 580     .name = "curl",
 581     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 582     .desc = {
 583         {
 584             .name = CURL_BLOCK_OPT_URL,
 585             .type = QEMU_OPT_STRING,
 586             .help = "URL to open",
 587         },
 588         {
 589             .name = CURL_BLOCK_OPT_READAHEAD,
 590             .type = QEMU_OPT_SIZE,
 591             .help = "Readahead size",
 592         },
 593         {
 594             .name = CURL_BLOCK_OPT_SSLVERIFY,
 595             .type = QEMU_OPT_BOOL,
 596             .help = "Verify SSL certificate"
 597         },
 598         {
 599             .name = CURL_BLOCK_OPT_TIMEOUT,
 600             .type = QEMU_OPT_NUMBER,
 601             .help = "Curl timeout"
 602         },
 603         {
 604             .name = CURL_BLOCK_OPT_COOKIE,
 605             .type = QEMU_OPT_STRING,
 606             .help = "Pass the cookie or list of cookies with each request"
 607         },
 608         {
 609             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
 610             .type = QEMU_OPT_STRING,
 611             .help = "ID of secret used as cookie passed with each request"
 612         },
 613         {
 614             .name = CURL_BLOCK_OPT_USERNAME,
 615             .type = QEMU_OPT_STRING,
 616             .help = "Username for HTTP auth"
 617         },
 618         {
 619             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 620             .type = QEMU_OPT_STRING,
 621             .help = "ID of secret used as password for HTTP auth",
 622         },
 623         {
 624             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 625             .type = QEMU_OPT_STRING,
 626             .help = "Username for HTTP proxy auth"
 627         },
 628         {
 629             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 630             .type = QEMU_OPT_STRING,
 631             .help = "ID of secret used as password for HTTP proxy auth",
 632         },
 633         { /* end of list */ }
 634     },
 635 };
 636
 637
 638 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 639                      Error **errp)
 640 {
 641     BDRVCURLState *s = bs->opaque;
 642     CURLState *state = NULL;
 643     QemuOpts *opts;
 644     const char *file;
 645     const char *cookie;
 646     const char *cookie_secret;
 647     double d;
 648     const char *secretid;
 649     const char *protocol_delimiter;
 650     int ret;
 651
 652     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
 653                                     errp);
 654     if (ret < 0) {
 655         return ret;
 656     }
 657
 658     if (!libcurl_initialized) {
 659         ret = curl_global_init(CURL_GLOBAL_ALL);
 660         if (ret) {
 661             error_setg(errp, "libcurl initialization failed with %d", ret);
 662             return -EIO;
 663         }
 664         libcurl_initialized = true;
 665     }
 666
 667     qemu_mutex_init(&s->mutex);
 668     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 669     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
 670         goto out_noclean;
 671     }
 672
 673     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 674                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
 675     if ((s->readahead_size & 0x1ff) != 0) {
 676         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 677                    s->readahead_size);
 678         goto out_noclean;
 679     }
 680
 681     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 682                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
 683     if (s->timeout > CURL_TIMEOUT_MAX) {
 684         error_setg(errp, "timeout parameter is too large or negative");
 685         goto out_noclean;
 686     }
 687
 688     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
 689                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
 690
 691     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 692     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
 693
 694     if (cookie && cookie_secret) {
 695         error_setg(errp,
 696                    "curl driver cannot handle both cookie and cookie secret");
 697         goto out_noclean;
 698     }
 699
 700     if (cookie_secret) {
 701         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
 702         if (!s->cookie) {
 703             goto out_noclean;
 704         }
 705     } else {
 706         s->cookie = g_strdup(cookie);
 707     }
 708
 709     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 710     if (file == NULL) {
 711         error_setg(errp, "curl block driver requires an 'url' option");
 712         goto out_noclean;
 713     }
 714
 715     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
 716         !strstart(protocol_delimiter, "://", NULL))
 717     {
 718         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
 719                    "start with '%s://')", bs->drv->protocol_name, file,
 720                    bs->drv->protocol_name);
 721         goto out_noclean;
 722     }
 723
 724     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 725     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 726
 727     if (secretid) {
 728         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 729         if (!s->password) {
 730             goto out_noclean;
 731         }
 732     }
 733
 734     s->proxyusername = g_strdup(
 735         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 736     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 737     if (secretid) {
 738         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 739         if (!s->proxypassword) {
 740             goto out_noclean;
 741         }
 742     }
 743
 744     trace_curl_open(file);
 745     qemu_co_queue_init(&s->free_state_waitq);
 746     s->aio_context = bdrv_get_aio_context(bs);
 747     s->url = g_strdup(file);
 748     qemu_mutex_lock(&s->mutex);
 749     state = curl_find_state(s);
 750     qemu_mutex_unlock(&s->mutex);
 751     if (!state) {
 752         goto out_noclean;
 753     }
 754
 755     // Get file size
 756
 757     if (curl_init_state(s, state) < 0) {
 758         goto out;
 759     }
 760
 761     s->accept_range = false;
 762     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 763     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 764                      curl_header_cb);
 765     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 766     if (curl_easy_perform(state->curl))
 767         goto out;
 768     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
 769         goto out;
 770     }
 771     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
 772      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
 773      * known and zero if it is really zero-length file. */
 774 #if LIBCURL_VERSION_NUM >= 0x071304
 775     if (d < 0) {
 776         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 777                 "Server didn't report file size.");
 778         goto out;
 779     }
 780 #else
 781     if (d <= 0) {
 782         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 783                 "Unknown file size or zero-length file.");
 784         goto out;
 785     }
 786 #endif
 787
 788     s->len = d;
 789
 790     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 791         || !strncasecmp(s->url, "https://", strlen("https://")))
 792         && !s->accept_range) {
 793         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 794                 "Server does not support 'range' (byte ranges).");
 795         goto out;
 796     }
 797     trace_curl_open_size(s->len);
 798
 799     qemu_mutex_lock(&s->mutex);
 800     curl_clean_state(state);
 801     qemu_mutex_unlock(&s->mutex);
 802     curl_easy_cleanup(state->curl);
 803     state->curl = NULL;
 804
 805     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 806
 807     qemu_opts_del(opts);
 808     return 0;
 809
 810 out:
 811     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 812     curl_easy_cleanup(state->curl);
 813     state->curl = NULL;
 814 out_noclean:
 815     qemu_mutex_destroy(&s->mutex);
 816     g_free(s->cookie);
 817     g_free(s->url);
 818     g_free(s->username);
 819     g_free(s->proxyusername);
 820     g_free(s->proxypassword);
 821     qemu_opts_del(opts);
 822     return -EINVAL;
 823 }
 824
 825 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
 826 {
 827     CURLState *state;
 828     int running;
 829
 830     BDRVCURLState *s = bs->opaque;
 831
 832     uint64_t start = acb->offset;
 833     uint64_t end;
 834
 835     qemu_mutex_lock(&s->mutex);
 836
 837     // In case we have the requested data already (e.g. read-ahead),
 838     // we can just call the callback and be done.
 839     if (curl_find_buf(s, start, acb->bytes, acb)) {
 840         goto out;
 841     }
 842
 843     // No cache found, so let's start a new request
 844     for (;;) {
 845         state = curl_find_state(s);
 846         if (state) {
 847             break;
 848         }
 849         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
 850     }
 851
 852     if (curl_init_state(s, state) < 0) {
 853         curl_clean_state(state);
 854         acb->ret = -EIO;
 855         goto out;
 856     }
 857
 858     acb->start = 0;
 859     acb->end = MIN(acb->bytes, s->len - start);
 860
 861     state->buf_off = 0;
 862     g_free(state->orig_buf);
 863     state->buf_start = start;
 864     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
 865     end = start + state->buf_len - 1;
 866     state->orig_buf = g_try_malloc(state->buf_len);
 867     if (state->buf_len && state->orig_buf == NULL) {
 868         curl_clean_state(state);
 869         acb->ret = -ENOMEM;
 870         goto out;
 871     }
 872     state->acb[0] = acb;
 873
 874     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
 875     trace_curl_setup_preadv(acb->bytes, start, state->range);
 876     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 877
 878     if (curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
 879         state->acb[0] = NULL;
 880         acb->ret = -EIO;
 881
 882         curl_clean_state(state);
 883         goto out;
 884     }
 885
 886     /* Tell curl it needs to kick things off */
 887     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 888
 889 out:
 890     qemu_mutex_unlock(&s->mutex);
 891 }
 892
 893 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
 894         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
 895 {
 896     CURLAIOCB acb = {
 897         .co = qemu_coroutine_self(),
 898         .ret = -EINPROGRESS,
 899         .qiov = qiov,
 900         .offset = offset,
 901         .bytes = bytes
 902     };
 903
 904     curl_setup_preadv(bs, &acb);
 905     while (acb.ret == -EINPROGRESS) {
 906         qemu_coroutine_yield();
 907     }
 908     return acb.ret;
 909 }
 910
 911 static void curl_close(BlockDriverState *bs)
 912 {
 913     BDRVCURLState *s = bs->opaque;
 914
 915     trace_curl_close();
 916     curl_detach_aio_context(bs);
 917     qemu_mutex_destroy(&s->mutex);
 918
 919     g_free(s->cookie);
 920     g_free(s->url);
 921     g_free(s->username);
 922     g_free(s->proxyusername);
 923     g_free(s->proxypassword);
 924 }
 925
 926 static int64_t curl_getlength(BlockDriverState *bs)
 927 {
 928     BDRVCURLState *s = bs->opaque;
 929     return s->len;
 930 }
 931
 932 static void curl_refresh_filename(BlockDriverState *bs)
 933 {
 934     BDRVCURLState *s = bs->opaque;
 935
 936     /* "readahead" and "timeout" do not change the guest-visible data,
 937      * so ignore them */
 938     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
 939         s->cookie || s->username || s->password || s->proxyusername ||
 940         s->proxypassword)
 941     {
 942         return;
 943     }
 944
 945     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
 946 }
 947
 948
 949 static const char *const curl_strong_runtime_opts[] = {
 950     CURL_BLOCK_OPT_URL,
 951     CURL_BLOCK_OPT_SSLVERIFY,
 952     CURL_BLOCK_OPT_COOKIE,
 953     CURL_BLOCK_OPT_COOKIE_SECRET,
 954     CURL_BLOCK_OPT_USERNAME,
 955     CURL_BLOCK_OPT_PASSWORD_SECRET,
 956     CURL_BLOCK_OPT_PROXY_USERNAME,
 957     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 958
 959     NULL
 960 };
 961
 962 static BlockDriver bdrv_http = {
 963     .format_name                = "http",
 964     .protocol_name              = "http",
 965
 966     .instance_size              = sizeof(BDRVCURLState),
 967     .bdrv_parse_filename        = curl_parse_filename,
 968     .bdrv_file_open             = curl_open,
 969     .bdrv_close                 = curl_close,
 970     .bdrv_getlength             = curl_getlength,
 971
 972     .bdrv_co_preadv             = curl_co_preadv,
 973
 974     .bdrv_detach_aio_context    = curl_detach_aio_context,
 975     .bdrv_attach_aio_context    = curl_attach_aio_context,
 976
 977     .bdrv_refresh_filename      = curl_refresh_filename,
 978     .strong_runtime_opts        = curl_strong_runtime_opts,
 979 };
 980
 981 static BlockDriver bdrv_https = {
 982     .format_name                = "https",
 983     .protocol_name              = "https",
 984
 985     .instance_size              = sizeof(BDRVCURLState),
 986     .bdrv_parse_filename        = curl_parse_filename,
 987     .bdrv_file_open             = curl_open,
 988     .bdrv_close                 = curl_close,
 989     .bdrv_getlength             = curl_getlength,
 990
 991     .bdrv_co_preadv             = curl_co_preadv,
 992
 993     .bdrv_detach_aio_context    = curl_detach_aio_context,
 994     .bdrv_attach_aio_context    = curl_attach_aio_context,
 995
 996     .bdrv_refresh_filename      = curl_refresh_filename,
 997     .strong_runtime_opts        = curl_strong_runtime_opts,
 998 };
 999
1000 static BlockDriver bdrv_ftp = {
1001     .format_name                = "ftp",
1002     .protocol_name              = "ftp",
1003
1004     .instance_size              = sizeof(BDRVCURLState),
1005     .bdrv_parse_filename        = curl_parse_filename,
1006     .bdrv_file_open             = curl_open,
1007     .bdrv_close                 = curl_close,
1008     .bdrv_getlength             = curl_getlength,
1009
1010     .bdrv_co_preadv             = curl_co_preadv,
1011
1012     .bdrv_detach_aio_context    = curl_detach_aio_context,
1013     .bdrv_attach_aio_context    = curl_attach_aio_context,
1014
1015     .bdrv_refresh_filename      = curl_refresh_filename,
1016     .strong_runtime_opts        = curl_strong_runtime_opts,
1017 };
1018
1019 static BlockDriver bdrv_ftps = {
1020     .format_name                = "ftps",
1021     .protocol_name              = "ftps",
1022
1023     .instance_size              = sizeof(BDRVCURLState),
1024     .bdrv_parse_filename        = curl_parse_filename,
1025     .bdrv_file_open             = curl_open,
1026     .bdrv_close                 = curl_close,
1027     .bdrv_getlength             = curl_getlength,
1028
1029     .bdrv_co_preadv             = curl_co_preadv,
1030
1031     .bdrv_detach_aio_context    = curl_detach_aio_context,
1032     .bdrv_attach_aio_context    = curl_attach_aio_context,
1033
1034     .bdrv_refresh_filename      = curl_refresh_filename,
1035     .strong_runtime_opts        = curl_strong_runtime_opts,
1036 };
1037
1038 static void curl_block_init(void)
1039 {
1040     bdrv_register(&bdrv_http);
1041     bdrv_register(&bdrv_https);
1042     bdrv_register(&bdrv_ftp);
1043     bdrv_register(&bdrv_ftps);
1044 }
1045
1046 block_init(curl_block_init);