block/curl.c

   1 /*
   2  * QEMU Block driver for CURL images
   3  *
   4  * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "qemu/osdep.h"
  25 #include "qapi/error.h"
  26 #include "qemu-common.h"
  27 #include "qemu/error-report.h"
  28 #include "block/block_int.h"
  29 #include "qapi/qmp/qbool.h"
  30 #include "qapi/qmp/qstring.h"
  31 #include "crypto/secret.h"
  32 #include <curl/curl.h>
  33 #include "qemu/cutils.h"
  34
  35 // #define DEBUG_CURL
  36 // #define DEBUG_VERBOSE
  37
  38 #ifdef DEBUG_CURL
  39 #define DEBUG_CURL_PRINT 1
  40 #else
  41 #define DEBUG_CURL_PRINT 0
  42 #endif
  43 #define DPRINTF(fmt, ...)                                            \
  44     do {                                                             \
  45         if (DEBUG_CURL_PRINT) {                                      \
  46             fprintf(stderr, fmt, ## __VA_ARGS__);                    \
  47         }                                                            \
  48     } while (0)
  49
  50 #if LIBCURL_VERSION_NUM >= 0x071000
  51 /* The multi interface timer callback was introduced in 7.16.0 */
  52 #define NEED_CURL_TIMER_CALLBACK
  53 #define HAVE_SOCKET_ACTION
  54 #endif
  55
  56 #ifndef HAVE_SOCKET_ACTION
  57 /* If curl_multi_socket_action isn't available, define it statically here in
  58  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
  59  * less efficient but still safe. */
  60 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
  61                                             curl_socket_t sockfd,
  62                                             int ev_bitmask,
  63                                             int *running_handles)
  64 {
  65     return curl_multi_socket(multi_handle, sockfd, running_handles);
  66 }
  67 #define curl_multi_socket_action __curl_multi_socket_action
  68 #endif
  69
  70 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  71                    CURLPROTO_FTP | CURLPROTO_FTPS)
  72
  73 #define CURL_NUM_STATES 8
  74 #define CURL_NUM_ACB    8
  75 #define READ_AHEAD_DEFAULT (256 * 1024)
  76 #define CURL_TIMEOUT_DEFAULT 5
  77 #define CURL_TIMEOUT_MAX 10000
  78
  79 #define FIND_RET_NONE   0
  80 #define FIND_RET_OK     1
  81 #define FIND_RET_WAIT   2
  82
  83 #define CURL_BLOCK_OPT_URL       "url"
  84 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  85 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  86 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
  87 #define CURL_BLOCK_OPT_COOKIE    "cookie"
  88 #define CURL_BLOCK_OPT_USERNAME "username"
  89 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
  90 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
  91 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
  92
  93 struct BDRVCURLState;
  94
  95 typedef struct CURLAIOCB {
  96     BlockAIOCB common;
  97     QEMUIOVector *qiov;
  98
  99     int64_t sector_num;
 100     int nb_sectors;
 101
 102     size_t start;
 103     size_t end;
 104 } CURLAIOCB;
 105
 106 typedef struct CURLSocket {
 107     int fd;
 108     QLIST_ENTRY(CURLSocket) next;
 109 } CURLSocket;
 110
 111 typedef struct CURLState
 112 {
 113     struct BDRVCURLState *s;
 114     CURLAIOCB *acb[CURL_NUM_ACB];
 115     CURL *curl;
 116     QLIST_HEAD(, CURLSocket) sockets;
 117     char *orig_buf;
 118     size_t buf_start;
 119     size_t buf_off;
 120     size_t buf_len;
 121     char range[128];
 122     char errmsg[CURL_ERROR_SIZE];
 123     char in_use;
 124 } CURLState;
 125
 126 typedef struct BDRVCURLState {
 127     CURLM *multi;
 128     QEMUTimer timer;
 129     size_t len;
 130     CURLState states[CURL_NUM_STATES];
 131     char *url;
 132     size_t readahead_size;
 133     bool sslverify;
 134     uint64_t timeout;
 135     char *cookie;
 136     bool accept_range;
 137     AioContext *aio_context;
 138     char *username;
 139     char *password;
 140     char *proxyusername;
 141     char *proxypassword;
 142 } BDRVCURLState;
 143
 144 static void curl_clean_state(CURLState *s);
 145 static void curl_multi_do(void *arg);
 146 static void curl_multi_read(void *arg);
 147
 148 #ifdef NEED_CURL_TIMER_CALLBACK
 149 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 150 {
 151     BDRVCURLState *s = opaque;
 152
 153     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
 154     if (timeout_ms == -1) {
 155         timer_del(&s->timer);
 156     } else {
 157         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 158         timer_mod(&s->timer,
 159                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 160     }
 161     return 0;
 162 }
 163 #endif
 164
 165 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 166                         void *userp, void *sp)
 167 {
 168     BDRVCURLState *s;
 169     CURLState *state = NULL;
 170     CURLSocket *socket;
 171
 172     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 173     s = state->s;
 174
 175     QLIST_FOREACH(socket, &state->sockets, next) {
 176         if (socket->fd == fd) {
 177             if (action == CURL_POLL_REMOVE) {
 178                 QLIST_REMOVE(socket, next);
 179                 g_free(socket);
 180             }
 181             break;
 182         }
 183     }
 184     if (!socket) {
 185         socket = g_new0(CURLSocket, 1);
 186         socket->fd = fd;
 187         QLIST_INSERT_HEAD(&state->sockets, socket, next);
 188     }
 189     socket = NULL;
 190
 191     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, (int)fd);
 192     switch (action) {
 193         case CURL_POLL_IN:
 194             aio_set_fd_handler(s->aio_context, fd, false,
 195                                curl_multi_read, NULL, NULL, state);
 196             break;
 197         case CURL_POLL_OUT:
 198             aio_set_fd_handler(s->aio_context, fd, false,
 199                                NULL, curl_multi_do, NULL, state);
 200             break;
 201         case CURL_POLL_INOUT:
 202             aio_set_fd_handler(s->aio_context, fd, false,
 203                                curl_multi_read, curl_multi_do, NULL, state);
 204             break;
 205         case CURL_POLL_REMOVE:
 206             aio_set_fd_handler(s->aio_context, fd, false,
 207                                NULL, NULL, NULL, NULL);
 208             break;
 209     }
 210
 211     return 0;
 212 }
 213
 214 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 215 {
 216     BDRVCURLState *s = opaque;
 217     size_t realsize = size * nmemb;
 218     const char *accept_line = "Accept-Ranges: bytes";
 219
 220     if (realsize >= strlen(accept_line)
 221         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
 222         s->accept_range = true;
 223     }
 224
 225     return realsize;
 226 }
 227
 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     int i;
 233
 234     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
 235
 236     if (!s || !s->orig_buf) {
 237         goto read_end;
 238     }
 239
 240     if (s->buf_off >= s->buf_len) {
 241         /* buffer full, read nothing */
 242         goto read_end;
 243     }
 244     realsize = MIN(realsize, s->buf_len - s->buf_off);
 245     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 246     s->buf_off += realsize;
 247
 248     for(i=0; i<CURL_NUM_ACB; i++) {
 249         CURLAIOCB *acb = s->acb[i];
 250
 251         if (!acb)
 252             continue;
 253
 254         if ((s->buf_off >= acb->end)) {
 255             size_t request_length = acb->nb_sectors * BDRV_SECTOR_SIZE;
 256
 257             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
 258                                 acb->end - acb->start);
 259
 260             if (acb->end - acb->start < request_length) {
 261                 size_t offset = acb->end - acb->start;
 262                 qemu_iovec_memset(acb->qiov, offset, 0,
 263                                   request_length - offset);
 264             }
 265
 266             acb->common.cb(acb->common.opaque, 0);
 267             qemu_aio_unref(acb);
 268             s->acb[i] = NULL;
 269         }
 270     }
 271
 272 read_end:
 273     /* curl will error out if we do not return this value */
 274     return size * nmemb;
 275 }
 276
 277 static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len,
 278                          CURLAIOCB *acb)
 279 {
 280     int i;
 281     size_t end = start + len;
 282     size_t clamped_end = MIN(end, s->len);
 283     size_t clamped_len = clamped_end - start;
 284
 285     for (i=0; i<CURL_NUM_STATES; i++) {
 286         CURLState *state = &s->states[i];
 287         size_t buf_end = (state->buf_start + state->buf_off);
 288         size_t buf_fend = (state->buf_start + state->buf_len);
 289
 290         if (!state->orig_buf)
 291             continue;
 292         if (!state->buf_off)
 293             continue;
 294
 295         // Does the existing buffer cover our section?
 296         if ((start >= state->buf_start) &&
 297             (start <= buf_end) &&
 298             (clamped_end >= state->buf_start) &&
 299             (clamped_end <= buf_end))
 300         {
 301             char *buf = state->orig_buf + (start - state->buf_start);
 302
 303             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
 304             if (clamped_len < len) {
 305                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
 306             }
 307             acb->common.cb(acb->common.opaque, 0);
 308
 309             return FIND_RET_OK;
 310         }
 311
 312         // Wait for unfinished chunks
 313         if (state->in_use &&
 314             (start >= state->buf_start) &&
 315             (start <= buf_fend) &&
 316             (clamped_end >= state->buf_start) &&
 317             (clamped_end <= buf_fend))
 318         {
 319             int j;
 320
 321             acb->start = start - state->buf_start;
 322             acb->end = acb->start + clamped_len;
 323
 324             for (j=0; j<CURL_NUM_ACB; j++) {
 325                 if (!state->acb[j]) {
 326                     state->acb[j] = acb;
 327                     return FIND_RET_WAIT;
 328                 }
 329             }
 330         }
 331     }
 332
 333     return FIND_RET_NONE;
 334 }
 335
 336 static void curl_multi_check_completion(BDRVCURLState *s)
 337 {
 338     int msgs_in_queue;
 339
 340     /* Try to find done transfers, so we can free the easy
 341      * handle again. */
 342     for (;;) {
 343         CURLMsg *msg;
 344         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 345
 346         /* Quit when there are no more completions */
 347         if (!msg)
 348             break;
 349
 350         if (msg->msg == CURLMSG_DONE) {
 351             CURLState *state = NULL;
 352             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 353                               (char **)&state);
 354
 355             /* ACBs for successful messages get completed in curl_read_cb */
 356             if (msg->data.result != CURLE_OK) {
 357                 int i;
 358                 static int errcount = 100;
 359
 360                 /* Don't lose the original error message from curl, since
 361                  * it contains extra data.
 362                  */
 363                 if (errcount > 0) {
 364                     error_report("curl: %s", state->errmsg);
 365                     if (--errcount == 0) {
 366                         error_report("curl: further errors suppressed");
 367                     }
 368                 }
 369
 370                 for (i = 0; i < CURL_NUM_ACB; i++) {
 371                     CURLAIOCB *acb = state->acb[i];
 372
 373                     if (acb == NULL) {
 374                         continue;
 375                     }
 376
 377                     acb->common.cb(acb->common.opaque, -EPROTO);
 378                     qemu_aio_unref(acb);
 379                     state->acb[i] = NULL;
 380                 }
 381             }
 382
 383             curl_clean_state(state);
 384             break;
 385         }
 386     }
 387 }
 388
 389 static void curl_multi_do_locked(CURLState *s)
 390 {
 391     CURLSocket *socket, *next_socket;
 392     int running;
 393     int r;
 394
 395     if (!s->s->multi) {
 396         return;
 397     }
 398
 399     /* Need to use _SAFE because curl_multi_socket_action() may trigger
 400      * curl_sock_cb() which might modify this list */
 401     QLIST_FOREACH_SAFE(socket, &s->sockets, next, next_socket) {
 402         do {
 403             r = curl_multi_socket_action(s->s->multi, socket->fd, 0, &running);
 404         } while (r == CURLM_CALL_MULTI_PERFORM);
 405     }
 406 }
 407
 408 static void curl_multi_do(void *arg)
 409 {
 410     CURLState *s = (CURLState *)arg;
 411
 412     aio_context_acquire(s->s->aio_context);
 413     curl_multi_do_locked(s);
 414     aio_context_release(s->s->aio_context);
 415 }
 416
 417 static void curl_multi_read(void *arg)
 418 {
 419     CURLState *s = (CURLState *)arg;
 420
 421     aio_context_acquire(s->s->aio_context);
 422     curl_multi_do_locked(s);
 423     curl_multi_check_completion(s->s);
 424     aio_context_release(s->s->aio_context);
 425 }
 426
 427 static void curl_multi_timeout_do(void *arg)
 428 {
 429 #ifdef NEED_CURL_TIMER_CALLBACK
 430     BDRVCURLState *s = (BDRVCURLState *)arg;
 431     int running;
 432
 433     if (!s->multi) {
 434         return;
 435     }
 436
 437     aio_context_acquire(s->aio_context);
 438     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 439
 440     curl_multi_check_completion(s);
 441     aio_context_release(s->aio_context);
 442 #else
 443     abort();
 444 #endif
 445 }
 446
 447 static CURLState *curl_init_state(BlockDriverState *bs, BDRVCURLState *s)
 448 {
 449     CURLState *state = NULL;
 450     int i, j;
 451
 452     do {
 453         for (i=0; i<CURL_NUM_STATES; i++) {
 454             for (j=0; j<CURL_NUM_ACB; j++)
 455                 if (s->states[i].acb[j])
 456                     continue;
 457             if (s->states[i].in_use)
 458                 continue;
 459
 460             state = &s->states[i];
 461             state->in_use = 1;
 462             break;
 463         }
 464         if (!state) {
 465             aio_poll(bdrv_get_aio_context(bs), true);
 466         }
 467     } while(!state);
 468
 469     if (!state->curl) {
 470         state->curl = curl_easy_init();
 471         if (!state->curl) {
 472             return NULL;
 473         }
 474         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 475         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 476                          (long) s->sslverify);
 477         if (s->cookie) {
 478             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
 479         }
 480         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
 481         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 482                          (void *)curl_read_cb);
 483         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 484         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 485         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 486         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 487         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 488         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 489         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 490
 491         if (s->username) {
 492             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
 493         }
 494         if (s->password) {
 495             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
 496         }
 497         if (s->proxyusername) {
 498             curl_easy_setopt(state->curl,
 499                              CURLOPT_PROXYUSERNAME, s->proxyusername);
 500         }
 501         if (s->proxypassword) {
 502             curl_easy_setopt(state->curl,
 503                              CURLOPT_PROXYPASSWORD, s->proxypassword);
 504         }
 505
 506         /* Restrict supported protocols to avoid security issues in the more
 507          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 508          * CVE-2013-0249.
 509          *
 510          * Restricting protocols is only supported from 7.19.4 upwards.
 511          */
 512 #if LIBCURL_VERSION_NUM >= 0x071304
 513         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 514         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 515 #endif
 516
 517 #ifdef DEBUG_VERBOSE
 518         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 519 #endif
 520     }
 521
 522     QLIST_INIT(&state->sockets);
 523     state->s = s;
 524
 525     return state;
 526 }
 527
 528 static void curl_clean_state(CURLState *s)
 529 {
 530     if (s->s->multi)
 531         curl_multi_remove_handle(s->s->multi, s->curl);
 532
 533     while (!QLIST_EMPTY(&s->sockets)) {
 534         CURLSocket *socket = QLIST_FIRST(&s->sockets);
 535
 536         QLIST_REMOVE(socket, next);
 537         g_free(socket);
 538     }
 539
 540     s->in_use = 0;
 541 }
 542
 543 static void curl_parse_filename(const char *filename, QDict *options,
 544                                 Error **errp)
 545 {
 546     qdict_put(options, CURL_BLOCK_OPT_URL, qstring_from_str(filename));
 547 }
 548
 549 static void curl_detach_aio_context(BlockDriverState *bs)
 550 {
 551     BDRVCURLState *s = bs->opaque;
 552     int i;
 553
 554     for (i = 0; i < CURL_NUM_STATES; i++) {
 555         if (s->states[i].in_use) {
 556             curl_clean_state(&s->states[i]);
 557         }
 558         if (s->states[i].curl) {
 559             curl_easy_cleanup(s->states[i].curl);
 560             s->states[i].curl = NULL;
 561         }
 562         g_free(s->states[i].orig_buf);
 563         s->states[i].orig_buf = NULL;
 564     }
 565     if (s->multi) {
 566         curl_multi_cleanup(s->multi);
 567         s->multi = NULL;
 568     }
 569
 570     timer_del(&s->timer);
 571 }
 572
 573 static void curl_attach_aio_context(BlockDriverState *bs,
 574                                     AioContext *new_context)
 575 {
 576     BDRVCURLState *s = bs->opaque;
 577
 578     aio_timer_init(new_context, &s->timer,
 579                    QEMU_CLOCK_REALTIME, SCALE_NS,
 580                    curl_multi_timeout_do, s);
 581
 582     assert(!s->multi);
 583     s->multi = curl_multi_init();
 584     s->aio_context = new_context;
 585     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 586 #ifdef NEED_CURL_TIMER_CALLBACK
 587     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 588     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 589 #endif
 590 }
 591
 592 static QemuOptsList runtime_opts = {
 593     .name = "curl",
 594     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 595     .desc = {
 596         {
 597             .name = CURL_BLOCK_OPT_URL,
 598             .type = QEMU_OPT_STRING,
 599             .help = "URL to open",
 600         },
 601         {
 602             .name = CURL_BLOCK_OPT_READAHEAD,
 603             .type = QEMU_OPT_SIZE,
 604             .help = "Readahead size",
 605         },
 606         {
 607             .name = CURL_BLOCK_OPT_SSLVERIFY,
 608             .type = QEMU_OPT_BOOL,
 609             .help = "Verify SSL certificate"
 610         },
 611         {
 612             .name = CURL_BLOCK_OPT_TIMEOUT,
 613             .type = QEMU_OPT_NUMBER,
 614             .help = "Curl timeout"
 615         },
 616         {
 617             .name = CURL_BLOCK_OPT_COOKIE,
 618             .type = QEMU_OPT_STRING,
 619             .help = "Pass the cookie or list of cookies with each request"
 620         },
 621         {
 622             .name = CURL_BLOCK_OPT_USERNAME,
 623             .type = QEMU_OPT_STRING,
 624             .help = "Username for HTTP auth"
 625         },
 626         {
 627             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 628             .type = QEMU_OPT_STRING,
 629             .help = "ID of secret used as password for HTTP auth",
 630         },
 631         {
 632             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 633             .type = QEMU_OPT_STRING,
 634             .help = "Username for HTTP proxy auth"
 635         },
 636         {
 637             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 638             .type = QEMU_OPT_STRING,
 639             .help = "ID of secret used as password for HTTP proxy auth",
 640         },
 641         { /* end of list */ }
 642     },
 643 };
 644
 645
 646 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 647                      Error **errp)
 648 {
 649     BDRVCURLState *s = bs->opaque;
 650     CURLState *state = NULL;
 651     QemuOpts *opts;
 652     Error *local_err = NULL;
 653     const char *file;
 654     const char *cookie;
 655     double d;
 656     const char *secretid;
 657
 658     static int inited = 0;
 659
 660     if (flags & BDRV_O_RDWR) {
 661         error_setg(errp, "curl block device does not support writes");
 662         return -EROFS;
 663     }
 664
 665     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 666     qemu_opts_absorb_qdict(opts, options, &local_err);
 667     if (local_err) {
 668         error_propagate(errp, local_err);
 669         goto out_noclean;
 670     }
 671
 672     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 673                                           READ_AHEAD_DEFAULT);
 674     if ((s->readahead_size & 0x1ff) != 0) {
 675         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 676                    s->readahead_size);
 677         goto out_noclean;
 678     }
 679
 680     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 681                                      CURL_TIMEOUT_DEFAULT);
 682     if (s->timeout > CURL_TIMEOUT_MAX) {
 683         error_setg(errp, "timeout parameter is too large or negative");
 684         goto out_noclean;
 685     }
 686
 687     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
 688
 689     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 690     s->cookie = g_strdup(cookie);
 691
 692     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 693     if (file == NULL) {
 694         error_setg(errp, "curl block driver requires an 'url' option");
 695         goto out_noclean;
 696     }
 697
 698     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 699     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 700
 701     if (secretid) {
 702         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 703         if (!s->password) {
 704             goto out_noclean;
 705         }
 706     }
 707
 708     s->proxyusername = g_strdup(
 709         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 710     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 711     if (secretid) {
 712         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 713         if (!s->proxypassword) {
 714             goto out_noclean;
 715         }
 716     }
 717
 718     if (!inited) {
 719         curl_global_init(CURL_GLOBAL_ALL);
 720         inited = 1;
 721     }
 722
 723     DPRINTF("CURL: Opening %s\n", file);
 724     s->aio_context = bdrv_get_aio_context(bs);
 725     s->url = g_strdup(file);
 726     state = curl_init_state(bs, s);
 727     if (!state)
 728         goto out_noclean;
 729
 730     // Get file size
 731
 732     s->accept_range = false;
 733     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 734     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 735                      curl_header_cb);
 736     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 737     if (curl_easy_perform(state->curl))
 738         goto out;
 739     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
 740         goto out;
 741     }
 742     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
 743      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
 744      * known and zero if it is realy zero-length file. */
 745 #if LIBCURL_VERSION_NUM >= 0x071304
 746     if (d < 0) {
 747         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 748                 "Server didn't report file size.");
 749         goto out;
 750     }
 751 #else
 752     if (d <= 0) {
 753         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 754                 "Unknown file size or zero-length file.");
 755         goto out;
 756     }
 757 #endif
 758
 759     s->len = (size_t)d;
 760
 761     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 762         || !strncasecmp(s->url, "https://", strlen("https://")))
 763         && !s->accept_range) {
 764         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 765                 "Server does not support 'range' (byte ranges).");
 766         goto out;
 767     }
 768     DPRINTF("CURL: Size = %zd\n", s->len);
 769
 770     curl_clean_state(state);
 771     curl_easy_cleanup(state->curl);
 772     state->curl = NULL;
 773
 774     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 775
 776     qemu_opts_del(opts);
 777     return 0;
 778
 779 out:
 780     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 781     curl_easy_cleanup(state->curl);
 782     state->curl = NULL;
 783 out_noclean:
 784     g_free(s->cookie);
 785     g_free(s->url);
 786     qemu_opts_del(opts);
 787     return -EINVAL;
 788 }
 789
 790 static const AIOCBInfo curl_aiocb_info = {
 791     .aiocb_size         = sizeof(CURLAIOCB),
 792 };
 793
 794
 795 static void curl_readv_bh_cb(void *p)
 796 {
 797     CURLState *state;
 798     int running;
 799     int ret = -EINPROGRESS;
 800
 801     CURLAIOCB *acb = p;
 802     BlockDriverState *bs = acb->common.bs;
 803     BDRVCURLState *s = bs->opaque;
 804     AioContext *ctx = bdrv_get_aio_context(bs);
 805
 806     size_t start = acb->sector_num * BDRV_SECTOR_SIZE;
 807     size_t end;
 808
 809     aio_context_acquire(ctx);
 810
 811     // In case we have the requested data already (e.g. read-ahead),
 812     // we can just call the callback and be done.
 813     switch (curl_find_buf(s, start, acb->nb_sectors * BDRV_SECTOR_SIZE, acb)) {
 814         case FIND_RET_OK:
 815             qemu_aio_unref(acb);
 816             // fall through
 817         case FIND_RET_WAIT:
 818             goto out;
 819         default:
 820             break;
 821     }
 822
 823     // No cache found, so let's start a new request
 824     state = curl_init_state(acb->common.bs, s);
 825     if (!state) {
 826         ret = -EIO;
 827         goto out;
 828     }
 829
 830     acb->start = 0;
 831     acb->end = MIN(acb->nb_sectors * BDRV_SECTOR_SIZE, s->len - start);
 832
 833     state->buf_off = 0;
 834     g_free(state->orig_buf);
 835     state->buf_start = start;
 836     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
 837     end = start + state->buf_len - 1;
 838     state->orig_buf = g_try_malloc(state->buf_len);
 839     if (state->buf_len && state->orig_buf == NULL) {
 840         curl_clean_state(state);
 841         ret = -ENOMEM;
 842         goto out;
 843     }
 844     state->acb[0] = acb;
 845
 846     snprintf(state->range, 127, "%zd-%zd", start, end);
 847     DPRINTF("CURL (AIO): Reading %llu at %zd (%s)\n",
 848             (acb->nb_sectors * BDRV_SECTOR_SIZE), start, state->range);
 849     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 850
 851     curl_multi_add_handle(s->multi, state->curl);
 852
 853     /* Tell curl it needs to kick things off */
 854     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 855
 856 out:
 857     aio_context_release(ctx);
 858     if (ret != -EINPROGRESS) {
 859         acb->common.cb(acb->common.opaque, ret);
 860         qemu_aio_unref(acb);
 861     }
 862 }
 863
 864 static BlockAIOCB *curl_aio_readv(BlockDriverState *bs,
 865         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 866         BlockCompletionFunc *cb, void *opaque)
 867 {
 868     CURLAIOCB *acb;
 869
 870     acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque);
 871
 872     acb->qiov = qiov;
 873     acb->sector_num = sector_num;
 874     acb->nb_sectors = nb_sectors;
 875
 876     aio_bh_schedule_oneshot(bdrv_get_aio_context(bs), curl_readv_bh_cb, acb);
 877     return &acb->common;
 878 }
 879
 880 static void curl_close(BlockDriverState *bs)
 881 {
 882     BDRVCURLState *s = bs->opaque;
 883
 884     DPRINTF("CURL: Close\n");
 885     curl_detach_aio_context(bs);
 886
 887     g_free(s->cookie);
 888     g_free(s->url);
 889 }
 890
 891 static int64_t curl_getlength(BlockDriverState *bs)
 892 {
 893     BDRVCURLState *s = bs->opaque;
 894     return s->len;
 895 }
 896
 897 static BlockDriver bdrv_http = {
 898     .format_name                = "http",
 899     .protocol_name              = "http",
 900
 901     .instance_size              = sizeof(BDRVCURLState),
 902     .bdrv_parse_filename        = curl_parse_filename,
 903     .bdrv_file_open             = curl_open,
 904     .bdrv_close                 = curl_close,
 905     .bdrv_getlength             = curl_getlength,
 906
 907     .bdrv_aio_readv             = curl_aio_readv,
 908
 909     .bdrv_detach_aio_context    = curl_detach_aio_context,
 910     .bdrv_attach_aio_context    = curl_attach_aio_context,
 911 };
 912
 913 static BlockDriver bdrv_https = {
 914     .format_name                = "https",
 915     .protocol_name              = "https",
 916
 917     .instance_size              = sizeof(BDRVCURLState),
 918     .bdrv_parse_filename        = curl_parse_filename,
 919     .bdrv_file_open             = curl_open,
 920     .bdrv_close                 = curl_close,
 921     .bdrv_getlength             = curl_getlength,
 922
 923     .bdrv_aio_readv             = curl_aio_readv,
 924
 925     .bdrv_detach_aio_context    = curl_detach_aio_context,
 926     .bdrv_attach_aio_context    = curl_attach_aio_context,
 927 };
 928
 929 static BlockDriver bdrv_ftp = {
 930     .format_name                = "ftp",
 931     .protocol_name              = "ftp",
 932
 933     .instance_size              = sizeof(BDRVCURLState),
 934     .bdrv_parse_filename        = curl_parse_filename,
 935     .bdrv_file_open             = curl_open,
 936     .bdrv_close                 = curl_close,
 937     .bdrv_getlength             = curl_getlength,
 938
 939     .bdrv_aio_readv             = curl_aio_readv,
 940
 941     .bdrv_detach_aio_context    = curl_detach_aio_context,
 942     .bdrv_attach_aio_context    = curl_attach_aio_context,
 943 };
 944
 945 static BlockDriver bdrv_ftps = {
 946     .format_name                = "ftps",
 947     .protocol_name              = "ftps",
 948
 949     .instance_size              = sizeof(BDRVCURLState),
 950     .bdrv_parse_filename        = curl_parse_filename,
 951     .bdrv_file_open             = curl_open,
 952     .bdrv_close                 = curl_close,
 953     .bdrv_getlength             = curl_getlength,
 954
 955     .bdrv_aio_readv             = curl_aio_readv,
 956
 957     .bdrv_detach_aio_context    = curl_detach_aio_context,
 958     .bdrv_attach_aio_context    = curl_attach_aio_context,
 959 };
 960
 961 static void curl_block_init(void)
 962 {
 963     bdrv_register(&bdrv_http);
 964     bdrv_register(&bdrv_https);
 965     bdrv_register(&bdrv_ftp);
 966     bdrv_register(&bdrv_ftps);
 967 }
 968
 969 block_init(curl_block_init);