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 BDRVCURLState *s;
  82 } CURLSocket;
  83
  84 typedef struct CURLState
  85 {
  86     struct BDRVCURLState *s;
  87     CURLAIOCB *acb[CURL_NUM_ACB];
  88     CURL *curl;
  89     char *orig_buf;
  90     uint64_t buf_start;
  91     size_t buf_off;
  92     size_t buf_len;
  93     char range[128];
  94     char errmsg[CURL_ERROR_SIZE];
  95     char in_use;
  96 } CURLState;
  97
  98 typedef struct BDRVCURLState {
  99     CURLM *multi;
 100     QEMUTimer timer;
 101     uint64_t len;
 102     CURLState states[CURL_NUM_STATES];
 103     GHashTable *sockets; /* GINT_TO_POINTER(fd) -> socket */
 104     char *url;
 105     size_t readahead_size;
 106     bool sslverify;
 107     uint64_t timeout;
 108     char *cookie;
 109     bool accept_range;
 110     AioContext *aio_context;
 111     QemuMutex mutex;
 112     CoQueue free_state_waitq;
 113     char *username;
 114     char *password;
 115     char *proxyusername;
 116     char *proxypassword;
 117 } BDRVCURLState;
 118
 119 static void curl_clean_state(CURLState *s);
 120 static void curl_multi_do(void *arg);
 121
 122 static gboolean curl_drop_socket(void *key, void *value, void *opaque)
 123 {
 124     CURLSocket *socket = value;
 125     BDRVCURLState *s = socket->s;
 126
 127     aio_set_fd_handler(s->aio_context, socket->fd, false,
 128                        NULL, NULL, NULL, NULL);
 129     return true;
 130 }
 131
 132 static void curl_drop_all_sockets(GHashTable *sockets)
 133 {
 134     g_hash_table_foreach_remove(sockets, curl_drop_socket, NULL);
 135 }
 136
 137 /* Called from curl_multi_do_locked, with s->mutex held.  */
 138 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 139 {
 140     BDRVCURLState *s = opaque;
 141
 142     trace_curl_timer_cb(timeout_ms);
 143     if (timeout_ms == -1) {
 144         timer_del(&s->timer);
 145     } else {
 146         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 147         timer_mod(&s->timer,
 148                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 149     }
 150     return 0;
 151 }
 152
 153 /* Called from curl_multi_do_locked, with s->mutex held.  */
 154 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 155                         void *userp, void *sp)
 156 {
 157     BDRVCURLState *s;
 158     CURLState *state = NULL;
 159     CURLSocket *socket;
 160
 161     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 162     s = state->s;
 163
 164     socket = g_hash_table_lookup(s->sockets, GINT_TO_POINTER(fd));
 165     if (!socket) {
 166         socket = g_new0(CURLSocket, 1);
 167         socket->fd = fd;
 168         socket->s = s;
 169         g_hash_table_insert(s->sockets, GINT_TO_POINTER(fd), socket);
 170     }
 171
 172     trace_curl_sock_cb(action, (int)fd);
 173     switch (action) {
 174         case CURL_POLL_IN:
 175             aio_set_fd_handler(s->aio_context, fd, false,
 176                                curl_multi_do, NULL, NULL, socket);
 177             break;
 178         case CURL_POLL_OUT:
 179             aio_set_fd_handler(s->aio_context, fd, false,
 180                                NULL, curl_multi_do, NULL, socket);
 181             break;
 182         case CURL_POLL_INOUT:
 183             aio_set_fd_handler(s->aio_context, fd, false,
 184                                curl_multi_do, curl_multi_do, NULL, socket);
 185             break;
 186         case CURL_POLL_REMOVE:
 187             aio_set_fd_handler(s->aio_context, fd, false,
 188                                NULL, NULL, NULL, NULL);
 189             break;
 190     }
 191
 192     if (action == CURL_POLL_REMOVE) {
 193         g_hash_table_remove(s->sockets, GINT_TO_POINTER(fd));
 194     }
 195
 196     return 0;
 197 }
 198
 199 /* Called from curl_multi_do_locked, with s->mutex held.  */
 200 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 201 {
 202     BDRVCURLState *s = opaque;
 203     size_t realsize = size * nmemb;
 204     const char *header = (char *)ptr;
 205     const char *end = header + realsize;
 206     const char *accept_ranges = "accept-ranges:";
 207     const char *bytes = "bytes";
 208
 209     if (realsize >= strlen(accept_ranges)
 210         && g_ascii_strncasecmp(header, accept_ranges,
 211                                strlen(accept_ranges)) == 0) {
 212
 213         char *p = strchr(header, ':') + 1;
 214
 215         /* Skip whitespace between the header name and value. */
 216         while (p < end && *p && g_ascii_isspace(*p)) {
 217             p++;
 218         }
 219
 220         if (end - p >= strlen(bytes)
 221             && strncmp(p, bytes, strlen(bytes)) == 0) {
 222
 223             /* Check that there is nothing but whitespace after the value. */
 224             p += strlen(bytes);
 225             while (p < end && *p && g_ascii_isspace(*p)) {
 226                 p++;
 227             }
 228
 229             if (p == end || !*p) {
 230                 s->accept_range = true;
 231             }
 232         }
 233     }
 234
 235     return realsize;
 236 }
 237
 238 /* Called from curl_multi_do_locked, with s->mutex held.  */
 239 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 240 {
 241     CURLState *s = ((CURLState*)opaque);
 242     size_t realsize = size * nmemb;
 243
 244     trace_curl_read_cb(realsize);
 245
 246     if (!s || !s->orig_buf) {
 247         goto read_end;
 248     }
 249
 250     if (s->buf_off >= s->buf_len) {
 251         /* buffer full, read nothing */
 252         goto read_end;
 253     }
 254     realsize = MIN(realsize, s->buf_len - s->buf_off);
 255     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 256     s->buf_off += realsize;
 257
 258 read_end:
 259     /* curl will error out if we do not return this value */
 260     return size * nmemb;
 261 }
 262
 263 /* Called with s->mutex held.  */
 264 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
 265                           CURLAIOCB *acb)
 266 {
 267     int i;
 268     uint64_t end = start + len;
 269     uint64_t clamped_end = MIN(end, s->len);
 270     uint64_t clamped_len = clamped_end - start;
 271
 272     for (i=0; i<CURL_NUM_STATES; i++) {
 273         CURLState *state = &s->states[i];
 274         uint64_t buf_end = (state->buf_start + state->buf_off);
 275         uint64_t buf_fend = (state->buf_start + state->buf_len);
 276
 277         if (!state->orig_buf)
 278             continue;
 279         if (!state->buf_off)
 280             continue;
 281
 282         // Does the existing buffer cover our section?
 283         if ((start >= state->buf_start) &&
 284             (start <= buf_end) &&
 285             (clamped_end >= state->buf_start) &&
 286             (clamped_end <= buf_end))
 287         {
 288             char *buf = state->orig_buf + (start - state->buf_start);
 289
 290             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
 291             if (clamped_len < len) {
 292                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
 293             }
 294             acb->ret = 0;
 295             return true;
 296         }
 297
 298         // Wait for unfinished chunks
 299         if (state->in_use &&
 300             (start >= state->buf_start) &&
 301             (start <= buf_fend) &&
 302             (clamped_end >= state->buf_start) &&
 303             (clamped_end <= buf_fend))
 304         {
 305             int j;
 306
 307             acb->start = start - state->buf_start;
 308             acb->end = acb->start + clamped_len;
 309
 310             for (j=0; j<CURL_NUM_ACB; j++) {
 311                 if (!state->acb[j]) {
 312                     state->acb[j] = acb;
 313                     return true;
 314                 }
 315             }
 316         }
 317     }
 318
 319     return false;
 320 }
 321
 322 /* Called with s->mutex held.  */
 323 static void curl_multi_check_completion(BDRVCURLState *s)
 324 {
 325     int msgs_in_queue;
 326
 327     /* Try to find done transfers, so we can free the easy
 328      * handle again. */
 329     for (;;) {
 330         CURLMsg *msg;
 331         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 332
 333         /* Quit when there are no more completions */
 334         if (!msg)
 335             break;
 336
 337         if (msg->msg == CURLMSG_DONE) {
 338             int i;
 339             CURLState *state = NULL;
 340             bool error = msg->data.result != CURLE_OK;
 341
 342             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 343                               (char **)&state);
 344
 345             if (error) {
 346                 static int errcount = 100;
 347
 348                 /* Don't lose the original error message from curl, since
 349                  * it contains extra data.
 350                  */
 351                 if (errcount > 0) {
 352                     error_report("curl: %s", state->errmsg);
 353                     if (--errcount == 0) {
 354                         error_report("curl: further errors suppressed");
 355                     }
 356                 }
 357             }
 358
 359             for (i = 0; i < CURL_NUM_ACB; i++) {
 360                 CURLAIOCB *acb = state->acb[i];
 361
 362                 if (acb == NULL) {
 363                     continue;
 364                 }
 365
 366                 if (!error) {
 367                     /* Assert that we have read all data */
 368                     assert(state->buf_off >= acb->end);
 369
 370                     qemu_iovec_from_buf(acb->qiov, 0,
 371                                         state->orig_buf + acb->start,
 372                                         acb->end - acb->start);
 373
 374                     if (acb->end - acb->start < acb->bytes) {
 375                         size_t offset = acb->end - acb->start;
 376                         qemu_iovec_memset(acb->qiov, offset, 0,
 377                                           acb->bytes - offset);
 378                     }
 379                 }
 380
 381                 acb->ret = error ? -EIO : 0;
 382                 state->acb[i] = NULL;
 383                 qemu_mutex_unlock(&s->mutex);
 384                 aio_co_wake(acb->co);
 385                 qemu_mutex_lock(&s->mutex);
 386             }
 387
 388             curl_clean_state(state);
 389             break;
 390         }
 391     }
 392 }
 393
 394 /* Called with s->mutex held.  */
 395 static void curl_multi_do_locked(CURLSocket *socket)
 396 {
 397     BDRVCURLState *s = socket->s;
 398     int running;
 399     int r;
 400
 401     if (!s->multi) {
 402         return;
 403     }
 404
 405     do {
 406         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
 407     } while (r == CURLM_CALL_MULTI_PERFORM);
 408 }
 409
 410 static void curl_multi_do(void *arg)
 411 {
 412     CURLSocket *socket = arg;
 413     BDRVCURLState *s = socket->s;
 414
 415     qemu_mutex_lock(&s->mutex);
 416     curl_multi_do_locked(socket);
 417     curl_multi_check_completion(s);
 418     qemu_mutex_unlock(&s->mutex);
 419 }
 420
 421 static void curl_multi_timeout_do(void *arg)
 422 {
 423     BDRVCURLState *s = (BDRVCURLState *)arg;
 424     int running;
 425
 426     if (!s->multi) {
 427         return;
 428     }
 429
 430     qemu_mutex_lock(&s->mutex);
 431     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 432
 433     curl_multi_check_completion(s);
 434     qemu_mutex_unlock(&s->mutex);
 435 }
 436
 437 /* Called with s->mutex held.  */
 438 static CURLState *curl_find_state(BDRVCURLState *s)
 439 {
 440     CURLState *state = NULL;
 441     int i;
 442
 443     for (i = 0; i < CURL_NUM_STATES; i++) {
 444         if (!s->states[i].in_use) {
 445             state = &s->states[i];
 446             state->in_use = 1;
 447             break;
 448         }
 449     }
 450     return state;
 451 }
 452
 453 static int curl_init_state(BDRVCURLState *s, CURLState *state)
 454 {
 455     if (!state->curl) {
 456         state->curl = curl_easy_init();
 457         if (!state->curl) {
 458             return -EIO;
 459         }
 460         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 461         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 462                          (long) s->sslverify);
 463         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
 464                          s->sslverify ? 2L : 0L);
 465         if (s->cookie) {
 466             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
 467         }
 468         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
 469         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 470                          (void *)curl_read_cb);
 471         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 472         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 473         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 474         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 475         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 476         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 477         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 478
 479         if (s->username) {
 480             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
 481         }
 482         if (s->password) {
 483             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
 484         }
 485         if (s->proxyusername) {
 486             curl_easy_setopt(state->curl,
 487                              CURLOPT_PROXYUSERNAME, s->proxyusername);
 488         }
 489         if (s->proxypassword) {
 490             curl_easy_setopt(state->curl,
 491                              CURLOPT_PROXYPASSWORD, s->proxypassword);
 492         }
 493
 494         /* Restrict supported protocols to avoid security issues in the more
 495          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 496          * CVE-2013-0249.
 497          *
 498          * Restricting protocols is only supported from 7.19.4 upwards.
 499          */
 500 #if LIBCURL_VERSION_NUM >= 0x071304
 501         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 502         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 503 #endif
 504
 505 #ifdef DEBUG_VERBOSE
 506         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 507 #endif
 508     }
 509
 510     state->s = s;
 511
 512     return 0;
 513 }
 514
 515 /* Called with s->mutex held.  */
 516 static void curl_clean_state(CURLState *s)
 517 {
 518     int j;
 519     for (j = 0; j < CURL_NUM_ACB; j++) {
 520         assert(!s->acb[j]);
 521     }
 522
 523     if (s->s->multi)
 524         curl_multi_remove_handle(s->s->multi, s->curl);
 525
 526     s->in_use = 0;
 527
 528     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
 529 }
 530
 531 static void curl_parse_filename(const char *filename, QDict *options,
 532                                 Error **errp)
 533 {
 534     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
 535 }
 536
 537 static void curl_detach_aio_context(BlockDriverState *bs)
 538 {
 539     BDRVCURLState *s = bs->opaque;
 540     int i;
 541
 542     WITH_QEMU_LOCK_GUARD(&s->mutex) {
 543         curl_drop_all_sockets(s->sockets);
 544         for (i = 0; i < CURL_NUM_STATES; i++) {
 545             if (s->states[i].in_use) {
 546                 curl_clean_state(&s->states[i]);
 547             }
 548             if (s->states[i].curl) {
 549                 curl_easy_cleanup(s->states[i].curl);
 550                 s->states[i].curl = NULL;
 551             }
 552             g_free(s->states[i].orig_buf);
 553             s->states[i].orig_buf = NULL;
 554         }
 555         if (s->multi) {
 556             curl_multi_cleanup(s->multi);
 557             s->multi = NULL;
 558         }
 559     }
 560
 561     timer_del(&s->timer);
 562 }
 563
 564 static void curl_attach_aio_context(BlockDriverState *bs,
 565                                     AioContext *new_context)
 566 {
 567     BDRVCURLState *s = bs->opaque;
 568
 569     aio_timer_init(new_context, &s->timer,
 570                    QEMU_CLOCK_REALTIME, SCALE_NS,
 571                    curl_multi_timeout_do, s);
 572
 573     assert(!s->multi);
 574     s->multi = curl_multi_init();
 575     s->aio_context = new_context;
 576     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 577     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 578     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 579 }
 580
 581 static QemuOptsList runtime_opts = {
 582     .name = "curl",
 583     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 584     .desc = {
 585         {
 586             .name = CURL_BLOCK_OPT_URL,
 587             .type = QEMU_OPT_STRING,
 588             .help = "URL to open",
 589         },
 590         {
 591             .name = CURL_BLOCK_OPT_READAHEAD,
 592             .type = QEMU_OPT_SIZE,
 593             .help = "Readahead size",
 594         },
 595         {
 596             .name = CURL_BLOCK_OPT_SSLVERIFY,
 597             .type = QEMU_OPT_BOOL,
 598             .help = "Verify SSL certificate"
 599         },
 600         {
 601             .name = CURL_BLOCK_OPT_TIMEOUT,
 602             .type = QEMU_OPT_NUMBER,
 603             .help = "Curl timeout"
 604         },
 605         {
 606             .name = CURL_BLOCK_OPT_COOKIE,
 607             .type = QEMU_OPT_STRING,
 608             .help = "Pass the cookie or list of cookies with each request"
 609         },
 610         {
 611             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
 612             .type = QEMU_OPT_STRING,
 613             .help = "ID of secret used as cookie passed with each request"
 614         },
 615         {
 616             .name = CURL_BLOCK_OPT_USERNAME,
 617             .type = QEMU_OPT_STRING,
 618             .help = "Username for HTTP auth"
 619         },
 620         {
 621             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 622             .type = QEMU_OPT_STRING,
 623             .help = "ID of secret used as password for HTTP auth",
 624         },
 625         {
 626             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 627             .type = QEMU_OPT_STRING,
 628             .help = "Username for HTTP proxy auth"
 629         },
 630         {
 631             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 632             .type = QEMU_OPT_STRING,
 633             .help = "ID of secret used as password for HTTP proxy auth",
 634         },
 635         { /* end of list */ }
 636     },
 637 };
 638
 639
 640 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 641                      Error **errp)
 642 {
 643     BDRVCURLState *s = bs->opaque;
 644     CURLState *state = NULL;
 645     QemuOpts *opts;
 646     const char *file;
 647     const char *cookie;
 648     const char *cookie_secret;
 649     double d;
 650     const char *secretid;
 651     const char *protocol_delimiter;
 652     int ret;
 653
 654     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
 655                                     errp);
 656     if (ret < 0) {
 657         return ret;
 658     }
 659
 660     if (!libcurl_initialized) {
 661         ret = curl_global_init(CURL_GLOBAL_ALL);
 662         if (ret) {
 663             error_setg(errp, "libcurl initialization failed with %d", ret);
 664             return -EIO;
 665         }
 666         libcurl_initialized = true;
 667     }
 668
 669     qemu_mutex_init(&s->mutex);
 670     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 671     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
 672         goto out_noclean;
 673     }
 674
 675     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 676                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
 677     if ((s->readahead_size & 0x1ff) != 0) {
 678         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 679                    s->readahead_size);
 680         goto out_noclean;
 681     }
 682
 683     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 684                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
 685     if (s->timeout > CURL_TIMEOUT_MAX) {
 686         error_setg(errp, "timeout parameter is too large or negative");
 687         goto out_noclean;
 688     }
 689
 690     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
 691                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
 692
 693     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 694     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
 695
 696     if (cookie && cookie_secret) {
 697         error_setg(errp,
 698                    "curl driver cannot handle both cookie and cookie secret");
 699         goto out_noclean;
 700     }
 701
 702     if (cookie_secret) {
 703         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
 704         if (!s->cookie) {
 705             goto out_noclean;
 706         }
 707     } else {
 708         s->cookie = g_strdup(cookie);
 709     }
 710
 711     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 712     if (file == NULL) {
 713         error_setg(errp, "curl block driver requires an 'url' option");
 714         goto out_noclean;
 715     }
 716
 717     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
 718         !strstart(protocol_delimiter, "://", NULL))
 719     {
 720         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
 721                    "start with '%s://')", bs->drv->protocol_name, file,
 722                    bs->drv->protocol_name);
 723         goto out_noclean;
 724     }
 725
 726     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 727     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 728
 729     if (secretid) {
 730         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 731         if (!s->password) {
 732             goto out_noclean;
 733         }
 734     }
 735
 736     s->proxyusername = g_strdup(
 737         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 738     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 739     if (secretid) {
 740         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 741         if (!s->proxypassword) {
 742             goto out_noclean;
 743         }
 744     }
 745
 746     trace_curl_open(file);
 747     qemu_co_queue_init(&s->free_state_waitq);
 748     s->aio_context = bdrv_get_aio_context(bs);
 749     s->url = g_strdup(file);
 750     s->sockets = g_hash_table_new_full(NULL, NULL, NULL, g_free);
 751     qemu_mutex_lock(&s->mutex);
 752     state = curl_find_state(s);
 753     qemu_mutex_unlock(&s->mutex);
 754     if (!state) {
 755         goto out_noclean;
 756     }
 757
 758     // Get file size
 759
 760     if (curl_init_state(s, state) < 0) {
 761         goto out;
 762     }
 763
 764     s->accept_range = false;
 765     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 766     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 767                      curl_header_cb);
 768     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 769     if (curl_easy_perform(state->curl))
 770         goto out;
 771     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
 772         goto out;
 773     }
 774     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
 775      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
 776      * known and zero if it is really zero-length file. */
 777 #if LIBCURL_VERSION_NUM >= 0x071304
 778     if (d < 0) {
 779         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 780                 "Server didn't report file size.");
 781         goto out;
 782     }
 783 #else
 784     if (d <= 0) {
 785         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 786                 "Unknown file size or zero-length file.");
 787         goto out;
 788     }
 789 #endif
 790
 791     s->len = d;
 792
 793     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 794         || !strncasecmp(s->url, "https://", strlen("https://")))
 795         && !s->accept_range) {
 796         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 797                 "Server does not support 'range' (byte ranges).");
 798         goto out;
 799     }
 800     trace_curl_open_size(s->len);
 801
 802     qemu_mutex_lock(&s->mutex);
 803     curl_clean_state(state);
 804     qemu_mutex_unlock(&s->mutex);
 805     curl_easy_cleanup(state->curl);
 806     state->curl = NULL;
 807
 808     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 809
 810     qemu_opts_del(opts);
 811     return 0;
 812
 813 out:
 814     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 815     curl_easy_cleanup(state->curl);
 816     state->curl = NULL;
 817 out_noclean:
 818     qemu_mutex_destroy(&s->mutex);
 819     g_free(s->cookie);
 820     g_free(s->url);
 821     g_free(s->username);
 822     g_free(s->proxyusername);
 823     g_free(s->proxypassword);
 824     curl_drop_all_sockets(s->sockets);
 825     g_hash_table_destroy(s->sockets);
 826     qemu_opts_del(opts);
 827     return -EINVAL;
 828 }
 829
 830 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
 831 {
 832     CURLState *state;
 833     int running;
 834
 835     BDRVCURLState *s = bs->opaque;
 836
 837     uint64_t start = acb->offset;
 838     uint64_t end;
 839
 840     qemu_mutex_lock(&s->mutex);
 841
 842     // In case we have the requested data already (e.g. read-ahead),
 843     // we can just call the callback and be done.
 844     if (curl_find_buf(s, start, acb->bytes, acb)) {
 845         goto out;
 846     }
 847
 848     // No cache found, so let's start a new request
 849     for (;;) {
 850         state = curl_find_state(s);
 851         if (state) {
 852             break;
 853         }
 854         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
 855     }
 856
 857     if (curl_init_state(s, state) < 0) {
 858         curl_clean_state(state);
 859         acb->ret = -EIO;
 860         goto out;
 861     }
 862
 863     acb->start = 0;
 864     acb->end = MIN(acb->bytes, s->len - start);
 865
 866     state->buf_off = 0;
 867     g_free(state->orig_buf);
 868     state->buf_start = start;
 869     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
 870     end = start + state->buf_len - 1;
 871     state->orig_buf = g_try_malloc(state->buf_len);
 872     if (state->buf_len && state->orig_buf == NULL) {
 873         curl_clean_state(state);
 874         acb->ret = -ENOMEM;
 875         goto out;
 876     }
 877     state->acb[0] = acb;
 878
 879     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
 880     trace_curl_setup_preadv(acb->bytes, start, state->range);
 881     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 882
 883     if (curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
 884         state->acb[0] = NULL;
 885         acb->ret = -EIO;
 886
 887         curl_clean_state(state);
 888         goto out;
 889     }
 890
 891     /* Tell curl it needs to kick things off */
 892     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 893
 894 out:
 895     qemu_mutex_unlock(&s->mutex);
 896 }
 897
 898 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
 899         int64_t offset, int64_t bytes, QEMUIOVector *qiov,
 900         BdrvRequestFlags flags)
 901 {
 902     CURLAIOCB acb = {
 903         .co = qemu_coroutine_self(),
 904         .ret = -EINPROGRESS,
 905         .qiov = qiov,
 906         .offset = offset,
 907         .bytes = bytes
 908     };
 909
 910     curl_setup_preadv(bs, &acb);
 911     while (acb.ret == -EINPROGRESS) {
 912         qemu_coroutine_yield();
 913     }
 914     return acb.ret;
 915 }
 916
 917 static void curl_close(BlockDriverState *bs)
 918 {
 919     BDRVCURLState *s = bs->opaque;
 920
 921     trace_curl_close();
 922     curl_detach_aio_context(bs);
 923     qemu_mutex_destroy(&s->mutex);
 924
 925     g_hash_table_destroy(s->sockets);
 926     g_free(s->cookie);
 927     g_free(s->url);
 928     g_free(s->username);
 929     g_free(s->proxyusername);
 930     g_free(s->proxypassword);
 931 }
 932
 933 static int64_t curl_getlength(BlockDriverState *bs)
 934 {
 935     BDRVCURLState *s = bs->opaque;
 936     return s->len;
 937 }
 938
 939 static void curl_refresh_filename(BlockDriverState *bs)
 940 {
 941     BDRVCURLState *s = bs->opaque;
 942
 943     /* "readahead" and "timeout" do not change the guest-visible data,
 944      * so ignore them */
 945     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
 946         s->cookie || s->username || s->password || s->proxyusername ||
 947         s->proxypassword)
 948     {
 949         return;
 950     }
 951
 952     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
 953 }
 954
 955
 956 static const char *const curl_strong_runtime_opts[] = {
 957     CURL_BLOCK_OPT_URL,
 958     CURL_BLOCK_OPT_SSLVERIFY,
 959     CURL_BLOCK_OPT_COOKIE,
 960     CURL_BLOCK_OPT_COOKIE_SECRET,
 961     CURL_BLOCK_OPT_USERNAME,
 962     CURL_BLOCK_OPT_PASSWORD_SECRET,
 963     CURL_BLOCK_OPT_PROXY_USERNAME,
 964     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 965
 966     NULL
 967 };
 968
 969 static BlockDriver bdrv_http = {
 970     .format_name                = "http",
 971     .protocol_name              = "http",
 972
 973     .instance_size              = sizeof(BDRVCURLState),
 974     .bdrv_parse_filename        = curl_parse_filename,
 975     .bdrv_file_open             = curl_open,
 976     .bdrv_close                 = curl_close,
 977     .bdrv_getlength             = curl_getlength,
 978
 979     .bdrv_co_preadv             = curl_co_preadv,
 980
 981     .bdrv_detach_aio_context    = curl_detach_aio_context,
 982     .bdrv_attach_aio_context    = curl_attach_aio_context,
 983
 984     .bdrv_refresh_filename      = curl_refresh_filename,
 985     .strong_runtime_opts        = curl_strong_runtime_opts,
 986 };
 987
 988 static BlockDriver bdrv_https = {
 989     .format_name                = "https",
 990     .protocol_name              = "https",
 991
 992     .instance_size              = sizeof(BDRVCURLState),
 993     .bdrv_parse_filename        = curl_parse_filename,
 994     .bdrv_file_open             = curl_open,
 995     .bdrv_close                 = curl_close,
 996     .bdrv_getlength             = curl_getlength,
 997
 998     .bdrv_co_preadv             = curl_co_preadv,
 999
1000     .bdrv_detach_aio_context    = curl_detach_aio_context,
1001     .bdrv_attach_aio_context    = curl_attach_aio_context,
1002
1003     .bdrv_refresh_filename      = curl_refresh_filename,
1004     .strong_runtime_opts        = curl_strong_runtime_opts,
1005 };
1006
1007 static BlockDriver bdrv_ftp = {
1008     .format_name                = "ftp",
1009     .protocol_name              = "ftp",
1010
1011     .instance_size              = sizeof(BDRVCURLState),
1012     .bdrv_parse_filename        = curl_parse_filename,
1013     .bdrv_file_open             = curl_open,
1014     .bdrv_close                 = curl_close,
1015     .bdrv_getlength             = curl_getlength,
1016
1017     .bdrv_co_preadv             = curl_co_preadv,
1018
1019     .bdrv_detach_aio_context    = curl_detach_aio_context,
1020     .bdrv_attach_aio_context    = curl_attach_aio_context,
1021
1022     .bdrv_refresh_filename      = curl_refresh_filename,
1023     .strong_runtime_opts        = curl_strong_runtime_opts,
1024 };
1025
1026 static BlockDriver bdrv_ftps = {
1027     .format_name                = "ftps",
1028     .protocol_name              = "ftps",
1029
1030     .instance_size              = sizeof(BDRVCURLState),
1031     .bdrv_parse_filename        = curl_parse_filename,
1032     .bdrv_file_open             = curl_open,
1033     .bdrv_close                 = curl_close,
1034     .bdrv_getlength             = curl_getlength,
1035
1036     .bdrv_co_preadv             = curl_co_preadv,
1037
1038     .bdrv_detach_aio_context    = curl_detach_aio_context,
1039     .bdrv_attach_aio_context    = curl_attach_aio_context,
1040
1041     .bdrv_refresh_filename      = curl_refresh_filename,
1042     .strong_runtime_opts        = curl_strong_runtime_opts,
1043 };
1044
1045 static void curl_block_init(void)
1046 {
1047     bdrv_register(&bdrv_http);
1048     bdrv_register(&bdrv_https);
1049     bdrv_register(&bdrv_ftp);
1050     bdrv_register(&bdrv_ftps);
1051 }
1052
1053 block_init(curl_block_init);