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 #if LIBCURL_VERSION_NUM >= 0x071000
  41 /* The multi interface timer callback was introduced in 7.16.0 */
  42 #define NEED_CURL_TIMER_CALLBACK
  43 #define HAVE_SOCKET_ACTION
  44 #endif
  45
  46 #ifndef HAVE_SOCKET_ACTION
  47 /* If curl_multi_socket_action isn't available, define it statically here in
  48  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
  49  * less efficient but still safe. */
  50 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
  51                                             curl_socket_t sockfd,
  52                                             int ev_bitmask,
  53                                             int *running_handles)
  54 {
  55     return curl_multi_socket(multi_handle, sockfd, running_handles);
  56 }
  57 #define curl_multi_socket_action __curl_multi_socket_action
  58 #endif
  59
  60 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  61                    CURLPROTO_FTP | CURLPROTO_FTPS)
  62
  63 #define CURL_NUM_STATES 8
  64 #define CURL_NUM_ACB    8
  65 #define CURL_TIMEOUT_MAX 10000
  66
  67 #define CURL_BLOCK_OPT_URL       "url"
  68 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  69 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  70 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
  71 #define CURL_BLOCK_OPT_COOKIE    "cookie"
  72 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
  73 #define CURL_BLOCK_OPT_USERNAME "username"
  74 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
  75 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
  76 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
  77
  78 #define CURL_BLOCK_OPT_READAHEAD_DEFAULT (256 * 1024)
  79 #define CURL_BLOCK_OPT_SSLVERIFY_DEFAULT true
  80 #define CURL_BLOCK_OPT_TIMEOUT_DEFAULT 5
  81
  82 struct BDRVCURLState;
  83 struct CURLState;
  84
  85 static bool libcurl_initialized;
  86
  87 typedef struct CURLAIOCB {
  88     Coroutine *co;
  89     QEMUIOVector *qiov;
  90
  91     uint64_t offset;
  92     uint64_t bytes;
  93     int ret;
  94
  95     size_t start;
  96     size_t end;
  97 } CURLAIOCB;
  98
  99 typedef struct CURLSocket {
 100     int fd;
 101     struct CURLState *state;
 102     QLIST_ENTRY(CURLSocket) next;
 103 } CURLSocket;
 104
 105 typedef struct CURLState
 106 {
 107     struct BDRVCURLState *s;
 108     CURLAIOCB *acb[CURL_NUM_ACB];
 109     CURL *curl;
 110     QLIST_HEAD(, CURLSocket) sockets;
 111     char *orig_buf;
 112     uint64_t buf_start;
 113     size_t buf_off;
 114     size_t buf_len;
 115     char range[128];
 116     char errmsg[CURL_ERROR_SIZE];
 117     char in_use;
 118 } CURLState;
 119
 120 typedef struct BDRVCURLState {
 121     CURLM *multi;
 122     QEMUTimer timer;
 123     uint64_t len;
 124     CURLState states[CURL_NUM_STATES];
 125     char *url;
 126     size_t readahead_size;
 127     bool sslverify;
 128     uint64_t timeout;
 129     char *cookie;
 130     bool accept_range;
 131     AioContext *aio_context;
 132     QemuMutex mutex;
 133     CoQueue free_state_waitq;
 134     char *username;
 135     char *password;
 136     char *proxyusername;
 137     char *proxypassword;
 138 } BDRVCURLState;
 139
 140 static void curl_clean_state(CURLState *s);
 141 static void curl_multi_do(void *arg);
 142
 143 #ifdef NEED_CURL_TIMER_CALLBACK
 144 /* Called from curl_multi_do_locked, with s->mutex held.  */
 145 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 146 {
 147     BDRVCURLState *s = opaque;
 148
 149     trace_curl_timer_cb(timeout_ms);
 150     if (timeout_ms == -1) {
 151         timer_del(&s->timer);
 152     } else {
 153         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 154         timer_mod(&s->timer,
 155                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 156     }
 157     return 0;
 158 }
 159 #endif
 160
 161 /* Called from curl_multi_do_locked, with s->mutex held.  */
 162 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 163                         void *userp, void *sp)
 164 {
 165     BDRVCURLState *s;
 166     CURLState *state = NULL;
 167     CURLSocket *socket;
 168
 169     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 170     s = state->s;
 171
 172     QLIST_FOREACH(socket, &state->sockets, next) {
 173         if (socket->fd == fd) {
 174             break;
 175         }
 176     }
 177     if (!socket) {
 178         socket = g_new0(CURLSocket, 1);
 179         socket->fd = fd;
 180         socket->state = state;
 181         QLIST_INSERT_HEAD(&state->sockets, socket, next);
 182     }
 183
 184     trace_curl_sock_cb(action, (int)fd);
 185     switch (action) {
 186         case CURL_POLL_IN:
 187             aio_set_fd_handler(s->aio_context, fd, false,
 188                                curl_multi_do, NULL, NULL, socket);
 189             break;
 190         case CURL_POLL_OUT:
 191             aio_set_fd_handler(s->aio_context, fd, false,
 192                                NULL, curl_multi_do, NULL, socket);
 193             break;
 194         case CURL_POLL_INOUT:
 195             aio_set_fd_handler(s->aio_context, fd, false,
 196                                curl_multi_do, curl_multi_do, NULL, socket);
 197             break;
 198         case CURL_POLL_REMOVE:
 199             aio_set_fd_handler(s->aio_context, fd, false,
 200                                NULL, NULL, NULL, NULL);
 201             break;
 202     }
 203
 204     if (action == CURL_POLL_REMOVE) {
 205         QLIST_REMOVE(socket, next);
 206         g_free(socket);
 207     }
 208
 209     return 0;
 210 }
 211
 212 /* Called from curl_multi_do_locked, with s->mutex held.  */
 213 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 214 {
 215     BDRVCURLState *s = opaque;
 216     size_t realsize = size * nmemb;
 217     const char *accept_line = "Accept-Ranges: bytes";
 218
 219     if (realsize >= strlen(accept_line)
 220         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
 221         s->accept_range = true;
 222     }
 223
 224     return realsize;
 225 }
 226
 227 /* Called from curl_multi_do_locked, with s->mutex held.  */
 228 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 229 {
 230     CURLState *s = ((CURLState*)opaque);
 231     size_t realsize = size * nmemb;
 232
 233     trace_curl_read_cb(realsize);
 234
 235     if (!s || !s->orig_buf) {
 236         goto read_end;
 237     }
 238
 239     if (s->buf_off >= s->buf_len) {
 240         /* buffer full, read nothing */
 241         goto read_end;
 242     }
 243     realsize = MIN(realsize, s->buf_len - s->buf_off);
 244     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 245     s->buf_off += realsize;
 246
 247 read_end:
 248     /* curl will error out if we do not return this value */
 249     return size * nmemb;
 250 }
 251
 252 /* Called with s->mutex held.  */
 253 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
 254                           CURLAIOCB *acb)
 255 {
 256     int i;
 257     uint64_t end = start + len;
 258     uint64_t clamped_end = MIN(end, s->len);
 259     uint64_t clamped_len = clamped_end - start;
 260
 261     for (i=0; i<CURL_NUM_STATES; i++) {
 262         CURLState *state = &s->states[i];
 263         uint64_t buf_end = (state->buf_start + state->buf_off);
 264         uint64_t buf_fend = (state->buf_start + state->buf_len);
 265
 266         if (!state->orig_buf)
 267             continue;
 268         if (!state->buf_off)
 269             continue;
 270
 271         // Does the existing buffer cover our section?
 272         if ((start >= state->buf_start) &&
 273             (start <= buf_end) &&
 274             (clamped_end >= state->buf_start) &&
 275             (clamped_end <= buf_end))
 276         {
 277             char *buf = state->orig_buf + (start - state->buf_start);
 278
 279             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
 280             if (clamped_len < len) {
 281                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
 282             }
 283             acb->ret = 0;
 284             return true;
 285         }
 286
 287         // Wait for unfinished chunks
 288         if (state->in_use &&
 289             (start >= state->buf_start) &&
 290             (start <= buf_fend) &&
 291             (clamped_end >= state->buf_start) &&
 292             (clamped_end <= buf_fend))
 293         {
 294             int j;
 295
 296             acb->start = start - state->buf_start;
 297             acb->end = acb->start + clamped_len;
 298
 299             for (j=0; j<CURL_NUM_ACB; j++) {
 300                 if (!state->acb[j]) {
 301                     state->acb[j] = acb;
 302                     return true;
 303                 }
 304             }
 305         }
 306     }
 307
 308     return false;
 309 }
 310
 311 /* Called with s->mutex held.  */
 312 static void curl_multi_check_completion(BDRVCURLState *s)
 313 {
 314     int msgs_in_queue;
 315
 316     /* Try to find done transfers, so we can free the easy
 317      * handle again. */
 318     for (;;) {
 319         CURLMsg *msg;
 320         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 321
 322         /* Quit when there are no more completions */
 323         if (!msg)
 324             break;
 325
 326         if (msg->msg == CURLMSG_DONE) {
 327             int i;
 328             CURLState *state = NULL;
 329             bool error = msg->data.result != CURLE_OK;
 330
 331             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 332                               (char **)&state);
 333
 334             if (error) {
 335                 static int errcount = 100;
 336
 337                 /* Don't lose the original error message from curl, since
 338                  * it contains extra data.
 339                  */
 340                 if (errcount > 0) {
 341                     error_report("curl: %s", state->errmsg);
 342                     if (--errcount == 0) {
 343                         error_report("curl: further errors suppressed");
 344                     }
 345                 }
 346             }
 347
 348             for (i = 0; i < CURL_NUM_ACB; i++) {
 349                 CURLAIOCB *acb = state->acb[i];
 350
 351                 if (acb == NULL) {
 352                     continue;
 353                 }
 354
 355                 if (!error) {
 356                     /* Assert that we have read all data */
 357                     assert(state->buf_off >= acb->end);
 358
 359                     qemu_iovec_from_buf(acb->qiov, 0,
 360                                         state->orig_buf + acb->start,
 361                                         acb->end - acb->start);
 362
 363                     if (acb->end - acb->start < acb->bytes) {
 364                         size_t offset = acb->end - acb->start;
 365                         qemu_iovec_memset(acb->qiov, offset, 0,
 366                                           acb->bytes - offset);
 367                     }
 368                 }
 369
 370                 acb->ret = error ? -EIO : 0;
 371                 state->acb[i] = NULL;
 372                 qemu_mutex_unlock(&s->mutex);
 373                 aio_co_wake(acb->co);
 374                 qemu_mutex_lock(&s->mutex);
 375             }
 376
 377             curl_clean_state(state);
 378             break;
 379         }
 380     }
 381 }
 382
 383 /* Called with s->mutex held.  */
 384 static void curl_multi_do_locked(CURLSocket *socket)
 385 {
 386     BDRVCURLState *s = socket->state->s;
 387     int running;
 388     int r;
 389
 390     if (!s->multi) {
 391         return;
 392     }
 393
 394     do {
 395         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
 396     } while (r == CURLM_CALL_MULTI_PERFORM);
 397 }
 398
 399 static void curl_multi_do(void *arg)
 400 {
 401     CURLSocket *socket = arg;
 402     BDRVCURLState *s = socket->state->s;
 403
 404     qemu_mutex_lock(&s->mutex);
 405     curl_multi_do_locked(socket);
 406     curl_multi_check_completion(s);
 407     qemu_mutex_unlock(&s->mutex);
 408 }
 409
 410 static void curl_multi_timeout_do(void *arg)
 411 {
 412 #ifdef NEED_CURL_TIMER_CALLBACK
 413     BDRVCURLState *s = (BDRVCURLState *)arg;
 414     int running;
 415
 416     if (!s->multi) {
 417         return;
 418     }
 419
 420     qemu_mutex_lock(&s->mutex);
 421     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 422
 423     curl_multi_check_completion(s);
 424     qemu_mutex_unlock(&s->mutex);
 425 #else
 426     abort();
 427 #endif
 428 }
 429
 430 /* Called with s->mutex held.  */
 431 static CURLState *curl_find_state(BDRVCURLState *s)
 432 {
 433     CURLState *state = NULL;
 434     int i;
 435
 436     for (i = 0; i < CURL_NUM_STATES; i++) {
 437         if (!s->states[i].in_use) {
 438             state = &s->states[i];
 439             state->in_use = 1;
 440             break;
 441         }
 442     }
 443     return state;
 444 }
 445
 446 static int curl_init_state(BDRVCURLState *s, CURLState *state)
 447 {
 448     if (!state->curl) {
 449         state->curl = curl_easy_init();
 450         if (!state->curl) {
 451             return -EIO;
 452         }
 453         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 454         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 455                          (long) s->sslverify);
 456         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
 457                          s->sslverify ? 2L : 0L);
 458         if (s->cookie) {
 459             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
 460         }
 461         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
 462         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 463                          (void *)curl_read_cb);
 464         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 465         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 466         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 467         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 468         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 469         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 470         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 471
 472         if (s->username) {
 473             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
 474         }
 475         if (s->password) {
 476             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
 477         }
 478         if (s->proxyusername) {
 479             curl_easy_setopt(state->curl,
 480                              CURLOPT_PROXYUSERNAME, s->proxyusername);
 481         }
 482         if (s->proxypassword) {
 483             curl_easy_setopt(state->curl,
 484                              CURLOPT_PROXYPASSWORD, s->proxypassword);
 485         }
 486
 487         /* Restrict supported protocols to avoid security issues in the more
 488          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 489          * CVE-2013-0249.
 490          *
 491          * Restricting protocols is only supported from 7.19.4 upwards.
 492          */
 493 #if LIBCURL_VERSION_NUM >= 0x071304
 494         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 495         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 496 #endif
 497
 498 #ifdef DEBUG_VERBOSE
 499         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 500 #endif
 501     }
 502
 503     QLIST_INIT(&state->sockets);
 504     state->s = s;
 505
 506     return 0;
 507 }
 508
 509 /* Called with s->mutex held.  */
 510 static void curl_clean_state(CURLState *s)
 511 {
 512     int j;
 513     for (j = 0; j < CURL_NUM_ACB; j++) {
 514         assert(!s->acb[j]);
 515     }
 516
 517     if (s->s->multi)
 518         curl_multi_remove_handle(s->s->multi, s->curl);
 519
 520     while (!QLIST_EMPTY(&s->sockets)) {
 521         CURLSocket *socket = QLIST_FIRST(&s->sockets);
 522
 523         QLIST_REMOVE(socket, next);
 524         g_free(socket);
 525     }
 526
 527     s->in_use = 0;
 528
 529     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
 530 }
 531
 532 static void curl_parse_filename(const char *filename, QDict *options,
 533                                 Error **errp)
 534 {
 535     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
 536 }
 537
 538 static void curl_detach_aio_context(BlockDriverState *bs)
 539 {
 540     BDRVCURLState *s = bs->opaque;
 541     int i;
 542
 543     qemu_mutex_lock(&s->mutex);
 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     qemu_mutex_unlock(&s->mutex);
 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 #ifdef NEED_CURL_TIMER_CALLBACK
 578     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 579     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 580 #endif
 581 }
 582
 583 static QemuOptsList runtime_opts = {
 584     .name = "curl",
 585     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 586     .desc = {
 587         {
 588             .name = CURL_BLOCK_OPT_URL,
 589             .type = QEMU_OPT_STRING,
 590             .help = "URL to open",
 591         },
 592         {
 593             .name = CURL_BLOCK_OPT_READAHEAD,
 594             .type = QEMU_OPT_SIZE,
 595             .help = "Readahead size",
 596         },
 597         {
 598             .name = CURL_BLOCK_OPT_SSLVERIFY,
 599             .type = QEMU_OPT_BOOL,
 600             .help = "Verify SSL certificate"
 601         },
 602         {
 603             .name = CURL_BLOCK_OPT_TIMEOUT,
 604             .type = QEMU_OPT_NUMBER,
 605             .help = "Curl timeout"
 606         },
 607         {
 608             .name = CURL_BLOCK_OPT_COOKIE,
 609             .type = QEMU_OPT_STRING,
 610             .help = "Pass the cookie or list of cookies with each request"
 611         },
 612         {
 613             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
 614             .type = QEMU_OPT_STRING,
 615             .help = "ID of secret used as cookie passed with each request"
 616         },
 617         {
 618             .name = CURL_BLOCK_OPT_USERNAME,
 619             .type = QEMU_OPT_STRING,
 620             .help = "Username for HTTP auth"
 621         },
 622         {
 623             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 624             .type = QEMU_OPT_STRING,
 625             .help = "ID of secret used as password for HTTP auth",
 626         },
 627         {
 628             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 629             .type = QEMU_OPT_STRING,
 630             .help = "Username for HTTP proxy auth"
 631         },
 632         {
 633             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 634             .type = QEMU_OPT_STRING,
 635             .help = "ID of secret used as password for HTTP proxy auth",
 636         },
 637         { /* end of list */ }
 638     },
 639 };
 640
 641
 642 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 643                      Error **errp)
 644 {
 645     BDRVCURLState *s = bs->opaque;
 646     CURLState *state = NULL;
 647     QemuOpts *opts;
 648     Error *local_err = NULL;
 649     const char *file;
 650     const char *cookie;
 651     const char *cookie_secret;
 652     double d;
 653     const char *secretid;
 654     const char *protocol_delimiter;
 655     int ret;
 656
 657     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
 658                                     errp);
 659     if (ret < 0) {
 660         return ret;
 661     }
 662
 663     if (!libcurl_initialized) {
 664         ret = curl_global_init(CURL_GLOBAL_ALL);
 665         if (ret) {
 666             error_setg(errp, "libcurl initialization failed with %d", ret);
 667             return -EIO;
 668         }
 669         libcurl_initialized = true;
 670     }
 671
 672     qemu_mutex_init(&s->mutex);
 673     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 674     qemu_opts_absorb_qdict(opts, options, &local_err);
 675     if (local_err) {
 676         error_propagate(errp, local_err);
 677         goto out_noclean;
 678     }
 679
 680     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 681                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
 682     if ((s->readahead_size & 0x1ff) != 0) {
 683         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 684                    s->readahead_size);
 685         goto out_noclean;
 686     }
 687
 688     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 689                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
 690     if (s->timeout > CURL_TIMEOUT_MAX) {
 691         error_setg(errp, "timeout parameter is too large or negative");
 692         goto out_noclean;
 693     }
 694
 695     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
 696                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
 697
 698     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 699     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
 700
 701     if (cookie && cookie_secret) {
 702         error_setg(errp,
 703                    "curl driver cannot handle both cookie and cookie secret");
 704         goto out_noclean;
 705     }
 706
 707     if (cookie_secret) {
 708         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
 709         if (!s->cookie) {
 710             goto out_noclean;
 711         }
 712     } else {
 713         s->cookie = g_strdup(cookie);
 714     }
 715
 716     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 717     if (file == NULL) {
 718         error_setg(errp, "curl block driver requires an 'url' option");
 719         goto out_noclean;
 720     }
 721
 722     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
 723         !strstart(protocol_delimiter, "://", NULL))
 724     {
 725         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
 726                    "start with '%s://')", bs->drv->protocol_name, file,
 727                    bs->drv->protocol_name);
 728         goto out_noclean;
 729     }
 730
 731     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 732     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 733
 734     if (secretid) {
 735         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 736         if (!s->password) {
 737             goto out_noclean;
 738         }
 739     }
 740
 741     s->proxyusername = g_strdup(
 742         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 743     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 744     if (secretid) {
 745         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 746         if (!s->proxypassword) {
 747             goto out_noclean;
 748         }
 749     }
 750
 751     trace_curl_open(file);
 752     qemu_co_queue_init(&s->free_state_waitq);
 753     s->aio_context = bdrv_get_aio_context(bs);
 754     s->url = g_strdup(file);
 755     qemu_mutex_lock(&s->mutex);
 756     state = curl_find_state(s);
 757     qemu_mutex_unlock(&s->mutex);
 758     if (!state) {
 759         goto out_noclean;
 760     }
 761
 762     // Get file size
 763
 764     if (curl_init_state(s, state) < 0) {
 765         goto out;
 766     }
 767
 768     s->accept_range = false;
 769     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 770     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 771                      curl_header_cb);
 772     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 773     if (curl_easy_perform(state->curl))
 774         goto out;
 775     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
 776         goto out;
 777     }
 778     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
 779      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
 780      * known and zero if it is really zero-length file. */
 781 #if LIBCURL_VERSION_NUM >= 0x071304
 782     if (d < 0) {
 783         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 784                 "Server didn't report file size.");
 785         goto out;
 786     }
 787 #else
 788     if (d <= 0) {
 789         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 790                 "Unknown file size or zero-length file.");
 791         goto out;
 792     }
 793 #endif
 794
 795     s->len = d;
 796
 797     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 798         || !strncasecmp(s->url, "https://", strlen("https://")))
 799         && !s->accept_range) {
 800         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 801                 "Server does not support 'range' (byte ranges).");
 802         goto out;
 803     }
 804     trace_curl_open_size(s->len);
 805
 806     qemu_mutex_lock(&s->mutex);
 807     curl_clean_state(state);
 808     qemu_mutex_unlock(&s->mutex);
 809     curl_easy_cleanup(state->curl);
 810     state->curl = NULL;
 811
 812     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 813
 814     qemu_opts_del(opts);
 815     return 0;
 816
 817 out:
 818     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 819     curl_easy_cleanup(state->curl);
 820     state->curl = NULL;
 821 out_noclean:
 822     qemu_mutex_destroy(&s->mutex);
 823     g_free(s->cookie);
 824     g_free(s->url);
 825     g_free(s->username);
 826     g_free(s->proxyusername);
 827     g_free(s->proxypassword);
 828     qemu_opts_del(opts);
 829     return -EINVAL;
 830 }
 831
 832 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
 833 {
 834     CURLState *state;
 835     int running;
 836
 837     BDRVCURLState *s = bs->opaque;
 838
 839     uint64_t start = acb->offset;
 840     uint64_t end;
 841
 842     qemu_mutex_lock(&s->mutex);
 843
 844     // In case we have the requested data already (e.g. read-ahead),
 845     // we can just call the callback and be done.
 846     if (curl_find_buf(s, start, acb->bytes, acb)) {
 847         goto out;
 848     }
 849
 850     // No cache found, so let's start a new request
 851     for (;;) {
 852         state = curl_find_state(s);
 853         if (state) {
 854             break;
 855         }
 856         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
 857     }
 858
 859     if (curl_init_state(s, state) < 0) {
 860         curl_clean_state(state);
 861         acb->ret = -EIO;
 862         goto out;
 863     }
 864
 865     acb->start = 0;
 866     acb->end = MIN(acb->bytes, s->len - start);
 867
 868     state->buf_off = 0;
 869     g_free(state->orig_buf);
 870     state->buf_start = start;
 871     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
 872     end = start + state->buf_len - 1;
 873     state->orig_buf = g_try_malloc(state->buf_len);
 874     if (state->buf_len && state->orig_buf == NULL) {
 875         curl_clean_state(state);
 876         acb->ret = -ENOMEM;
 877         goto out;
 878     }
 879     state->acb[0] = acb;
 880
 881     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
 882     trace_curl_setup_preadv(acb->bytes, start, state->range);
 883     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 884
 885     if (curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
 886         state->acb[0] = NULL;
 887         acb->ret = -EIO;
 888
 889         curl_clean_state(state);
 890         goto out;
 891     }
 892
 893     /* Tell curl it needs to kick things off */
 894     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 895
 896 out:
 897     qemu_mutex_unlock(&s->mutex);
 898 }
 899
 900 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
 901         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
 902 {
 903     CURLAIOCB acb = {
 904         .co = qemu_coroutine_self(),
 905         .ret = -EINPROGRESS,
 906         .qiov = qiov,
 907         .offset = offset,
 908         .bytes = bytes
 909     };
 910
 911     curl_setup_preadv(bs, &acb);
 912     while (acb.ret == -EINPROGRESS) {
 913         qemu_coroutine_yield();
 914     }
 915     return acb.ret;
 916 }
 917
 918 static void curl_close(BlockDriverState *bs)
 919 {
 920     BDRVCURLState *s = bs->opaque;
 921
 922     trace_curl_close();
 923     curl_detach_aio_context(bs);
 924     qemu_mutex_destroy(&s->mutex);
 925
 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);