block/curl.c

   1 /*
   2  * QEMU Block driver for CURL images
   3  *
   4  * Copyright (c) 2009 Alexander Graf <[email protected]>
   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 CURL_BLOCK_OPT_URL       "url"
  80 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  81 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  82 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
  83 #define CURL_BLOCK_OPT_COOKIE    "cookie"
  84 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
  85 #define CURL_BLOCK_OPT_USERNAME "username"
  86 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
  87 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
  88 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
  89
  90 struct BDRVCURLState;
  91
  92 static bool libcurl_initialized;
  93
  94 typedef struct CURLAIOCB {
  95     Coroutine *co;
  96     QEMUIOVector *qiov;
  97
  98     uint64_t offset;
  99     uint64_t bytes;
 100     int ret;
 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     uint64_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     uint64_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     QemuMutex mutex;
 139     CoQueue free_state_waitq;
 140     char *username;
 141     char *password;
 142     char *proxyusername;
 143     char *proxypassword;
 144 } BDRVCURLState;
 145
 146 static void curl_clean_state(CURLState *s);
 147 static void curl_multi_do(void *arg);
 148 static void curl_multi_read(void *arg);
 149
 150 #ifdef NEED_CURL_TIMER_CALLBACK
 151 /* Called from curl_multi_do_locked, with s->mutex held.  */
 152 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 153 {
 154     BDRVCURLState *s = opaque;
 155
 156     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
 157     if (timeout_ms == -1) {
 158         timer_del(&s->timer);
 159     } else {
 160         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 161         timer_mod(&s->timer,
 162                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 163     }
 164     return 0;
 165 }
 166 #endif
 167
 168 /* Called from curl_multi_do_locked, with s->mutex held.  */
 169 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 170                         void *userp, void *sp)
 171 {
 172     BDRVCURLState *s;
 173     CURLState *state = NULL;
 174     CURLSocket *socket;
 175
 176     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 177     s = state->s;
 178
 179     QLIST_FOREACH(socket, &state->sockets, next) {
 180         if (socket->fd == fd) {
 181             if (action == CURL_POLL_REMOVE) {
 182                 QLIST_REMOVE(socket, next);
 183                 g_free(socket);
 184             }
 185             break;
 186         }
 187     }
 188     if (!socket) {
 189         socket = g_new0(CURLSocket, 1);
 190         socket->fd = fd;
 191         QLIST_INSERT_HEAD(&state->sockets, socket, next);
 192     }
 193     socket = NULL;
 194
 195     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, (int)fd);
 196     switch (action) {
 197         case CURL_POLL_IN:
 198             aio_set_fd_handler(s->aio_context, fd, false,
 199                                curl_multi_read, NULL, NULL, state);
 200             break;
 201         case CURL_POLL_OUT:
 202             aio_set_fd_handler(s->aio_context, fd, false,
 203                                NULL, curl_multi_do, NULL, state);
 204             break;
 205         case CURL_POLL_INOUT:
 206             aio_set_fd_handler(s->aio_context, fd, false,
 207                                curl_multi_read, curl_multi_do, NULL, state);
 208             break;
 209         case CURL_POLL_REMOVE:
 210             aio_set_fd_handler(s->aio_context, fd, false,
 211                                NULL, NULL, NULL, NULL);
 212             break;
 213     }
 214
 215     return 0;
 216 }
 217
 218 /* Called from curl_multi_do_locked, with s->mutex held.  */
 219 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 220 {
 221     BDRVCURLState *s = opaque;
 222     size_t realsize = size * nmemb;
 223     const char *accept_line = "Accept-Ranges: bytes";
 224
 225     if (realsize >= strlen(accept_line)
 226         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
 227         s->accept_range = true;
 228     }
 229
 230     return realsize;
 231 }
 232
 233 /* Called from curl_multi_do_locked, with s->mutex held.  */
 234 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 235 {
 236     CURLState *s = ((CURLState*)opaque);
 237     size_t realsize = size * nmemb;
 238     int i;
 239
 240     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
 241
 242     if (!s || !s->orig_buf) {
 243         goto read_end;
 244     }
 245
 246     if (s->buf_off >= s->buf_len) {
 247         /* buffer full, read nothing */
 248         goto read_end;
 249     }
 250     realsize = MIN(realsize, s->buf_len - s->buf_off);
 251     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 252     s->buf_off += realsize;
 253
 254     for(i=0; i<CURL_NUM_ACB; i++) {
 255         CURLAIOCB *acb = s->acb[i];
 256
 257         if (!acb)
 258             continue;
 259
 260         if ((s->buf_off >= acb->end)) {
 261             size_t request_length = acb->bytes;
 262
 263             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
 264                                 acb->end - acb->start);
 265
 266             if (acb->end - acb->start < request_length) {
 267                 size_t offset = acb->end - acb->start;
 268                 qemu_iovec_memset(acb->qiov, offset, 0,
 269                                   request_length - offset);
 270             }
 271
 272             acb->ret = 0;
 273             s->acb[i] = NULL;
 274             qemu_mutex_unlock(&s->s->mutex);
 275             aio_co_wake(acb->co);
 276             qemu_mutex_lock(&s->s->mutex);
 277         }
 278     }
 279
 280 read_end:
 281     /* curl will error out if we do not return this value */
 282     return size * nmemb;
 283 }
 284
 285 /* Called with s->mutex held.  */
 286 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
 287                           CURLAIOCB *acb)
 288 {
 289     int i;
 290     uint64_t end = start + len;
 291     uint64_t clamped_end = MIN(end, s->len);
 292     uint64_t clamped_len = clamped_end - start;
 293
 294     for (i=0; i<CURL_NUM_STATES; i++) {
 295         CURLState *state = &s->states[i];
 296         uint64_t buf_end = (state->buf_start + state->buf_off);
 297         uint64_t buf_fend = (state->buf_start + state->buf_len);
 298
 299         if (!state->orig_buf)
 300             continue;
 301         if (!state->buf_off)
 302             continue;
 303
 304         // Does the existing buffer cover our section?
 305         if ((start >= state->buf_start) &&
 306             (start <= buf_end) &&
 307             (clamped_end >= state->buf_start) &&
 308             (clamped_end <= buf_end))
 309         {
 310             char *buf = state->orig_buf + (start - state->buf_start);
 311
 312             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
 313             if (clamped_len < len) {
 314                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
 315             }
 316             acb->ret = 0;
 317             return true;
 318         }
 319
 320         // Wait for unfinished chunks
 321         if (state->in_use &&
 322             (start >= state->buf_start) &&
 323             (start <= buf_fend) &&
 324             (clamped_end >= state->buf_start) &&
 325             (clamped_end <= buf_fend))
 326         {
 327             int j;
 328
 329             acb->start = start - state->buf_start;
 330             acb->end = acb->start + clamped_len;
 331
 332             for (j=0; j<CURL_NUM_ACB; j++) {
 333                 if (!state->acb[j]) {
 334                     state->acb[j] = acb;
 335                     return true;
 336                 }
 337             }
 338         }
 339     }
 340
 341     return false;
 342 }
 343
 344 /* Called with s->mutex held.  */
 345 static void curl_multi_check_completion(BDRVCURLState *s)
 346 {
 347     int msgs_in_queue;
 348
 349     /* Try to find done transfers, so we can free the easy
 350      * handle again. */
 351     for (;;) {
 352         CURLMsg *msg;
 353         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 354
 355         /* Quit when there are no more completions */
 356         if (!msg)
 357             break;
 358
 359         if (msg->msg == CURLMSG_DONE) {
 360             CURLState *state = NULL;
 361             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 362                               (char **)&state);
 363
 364             /* ACBs for successful messages get completed in curl_read_cb */
 365             if (msg->data.result != CURLE_OK) {
 366                 int i;
 367                 static int errcount = 100;
 368
 369                 /* Don't lose the original error message from curl, since
 370                  * it contains extra data.
 371                  */
 372                 if (errcount > 0) {
 373                     error_report("curl: %s", state->errmsg);
 374                     if (--errcount == 0) {
 375                         error_report("curl: further errors suppressed");
 376                     }
 377                 }
 378
 379                 for (i = 0; i < CURL_NUM_ACB; i++) {
 380                     CURLAIOCB *acb = state->acb[i];
 381
 382                     if (acb == NULL) {
 383                         continue;
 384                     }
 385
 386                     acb->ret = -EIO;
 387                     state->acb[i] = NULL;
 388                     qemu_mutex_unlock(&s->mutex);
 389                     aio_co_wake(acb->co);
 390                     qemu_mutex_lock(&s->mutex);
 391                 }
 392             }
 393
 394             curl_clean_state(state);
 395             break;
 396         }
 397     }
 398 }
 399
 400 /* Called with s->mutex held.  */
 401 static void curl_multi_do_locked(CURLState *s)
 402 {
 403     CURLSocket *socket, *next_socket;
 404     int running;
 405     int r;
 406
 407     if (!s->s->multi) {
 408         return;
 409     }
 410
 411     /* Need to use _SAFE because curl_multi_socket_action() may trigger
 412      * curl_sock_cb() which might modify this list */
 413     QLIST_FOREACH_SAFE(socket, &s->sockets, next, next_socket) {
 414         do {
 415             r = curl_multi_socket_action(s->s->multi, socket->fd, 0, &running);
 416         } while (r == CURLM_CALL_MULTI_PERFORM);
 417     }
 418 }
 419
 420 static void curl_multi_do(void *arg)
 421 {
 422     CURLState *s = (CURLState *)arg;
 423
 424     qemu_mutex_lock(&s->s->mutex);
 425     curl_multi_do_locked(s);
 426     qemu_mutex_unlock(&s->s->mutex);
 427 }
 428
 429 static void curl_multi_read(void *arg)
 430 {
 431     CURLState *s = (CURLState *)arg;
 432
 433     qemu_mutex_lock(&s->s->mutex);
 434     curl_multi_do_locked(s);
 435     curl_multi_check_completion(s->s);
 436     qemu_mutex_unlock(&s->s->mutex);
 437 }
 438
 439 static void curl_multi_timeout_do(void *arg)
 440 {
 441 #ifdef NEED_CURL_TIMER_CALLBACK
 442     BDRVCURLState *s = (BDRVCURLState *)arg;
 443     int running;
 444
 445     if (!s->multi) {
 446         return;
 447     }
 448
 449     qemu_mutex_lock(&s->mutex);
 450     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 451
 452     curl_multi_check_completion(s);
 453     qemu_mutex_unlock(&s->mutex);
 454 #else
 455     abort();
 456 #endif
 457 }
 458
 459 /* Called with s->mutex held.  */
 460 static CURLState *curl_find_state(BDRVCURLState *s)
 461 {
 462     CURLState *state = NULL;
 463     int i;
 464
 465     for (i = 0; i < CURL_NUM_STATES; i++) {
 466         if (!s->states[i].in_use) {
 467             state = &s->states[i];
 468             state->in_use = 1;
 469             break;
 470         }
 471     }
 472     return state;
 473 }
 474
 475 static int curl_init_state(BDRVCURLState *s, CURLState *state)
 476 {
 477     if (!state->curl) {
 478         state->curl = curl_easy_init();
 479         if (!state->curl) {
 480             return -EIO;
 481         }
 482         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 483         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 484                          (long) s->sslverify);
 485         if (s->cookie) {
 486             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
 487         }
 488         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
 489         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 490                          (void *)curl_read_cb);
 491         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 492         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 493         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 494         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 495         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 496         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 497         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 498
 499         if (s->username) {
 500             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
 501         }
 502         if (s->password) {
 503             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
 504         }
 505         if (s->proxyusername) {
 506             curl_easy_setopt(state->curl,
 507                              CURLOPT_PROXYUSERNAME, s->proxyusername);
 508         }
 509         if (s->proxypassword) {
 510             curl_easy_setopt(state->curl,
 511                              CURLOPT_PROXYPASSWORD, s->proxypassword);
 512         }
 513
 514         /* Restrict supported protocols to avoid security issues in the more
 515          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 516          * CVE-2013-0249.
 517          *
 518          * Restricting protocols is only supported from 7.19.4 upwards.
 519          */
 520 #if LIBCURL_VERSION_NUM >= 0x071304
 521         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 522         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 523 #endif
 524
 525 #ifdef DEBUG_VERBOSE
 526         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 527 #endif
 528     }
 529
 530     QLIST_INIT(&state->sockets);
 531     state->s = s;
 532
 533     return 0;
 534 }
 535
 536 /* Called with s->mutex held.  */
 537 static void curl_clean_state(CURLState *s)
 538 {
 539     int j;
 540     for (j = 0; j < CURL_NUM_ACB; j++) {
 541         assert(!s->acb[j]);
 542     }
 543
 544     if (s->s->multi)
 545         curl_multi_remove_handle(s->s->multi, s->curl);
 546
 547     while (!QLIST_EMPTY(&s->sockets)) {
 548         CURLSocket *socket = QLIST_FIRST(&s->sockets);
 549
 550         QLIST_REMOVE(socket, next);
 551         g_free(socket);
 552     }
 553
 554     s->in_use = 0;
 555
 556     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
 557 }
 558
 559 static void curl_parse_filename(const char *filename, QDict *options,
 560                                 Error **errp)
 561 {
 562     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
 563 }
 564
 565 static void curl_detach_aio_context(BlockDriverState *bs)
 566 {
 567     BDRVCURLState *s = bs->opaque;
 568     int i;
 569
 570     qemu_mutex_lock(&s->mutex);
 571     for (i = 0; i < CURL_NUM_STATES; i++) {
 572         if (s->states[i].in_use) {
 573             curl_clean_state(&s->states[i]);
 574         }
 575         if (s->states[i].curl) {
 576             curl_easy_cleanup(s->states[i].curl);
 577             s->states[i].curl = NULL;
 578         }
 579         g_free(s->states[i].orig_buf);
 580         s->states[i].orig_buf = NULL;
 581     }
 582     if (s->multi) {
 583         curl_multi_cleanup(s->multi);
 584         s->multi = NULL;
 585     }
 586     qemu_mutex_unlock(&s->mutex);
 587
 588     timer_del(&s->timer);
 589 }
 590
 591 static void curl_attach_aio_context(BlockDriverState *bs,
 592                                     AioContext *new_context)
 593 {
 594     BDRVCURLState *s = bs->opaque;
 595
 596     aio_timer_init(new_context, &s->timer,
 597                    QEMU_CLOCK_REALTIME, SCALE_NS,
 598                    curl_multi_timeout_do, s);
 599
 600     assert(!s->multi);
 601     s->multi = curl_multi_init();
 602     s->aio_context = new_context;
 603     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 604 #ifdef NEED_CURL_TIMER_CALLBACK
 605     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 606     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 607 #endif
 608 }
 609
 610 static QemuOptsList runtime_opts = {
 611     .name = "curl",
 612     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 613     .desc = {
 614         {
 615             .name = CURL_BLOCK_OPT_URL,
 616             .type = QEMU_OPT_STRING,
 617             .help = "URL to open",
 618         },
 619         {
 620             .name = CURL_BLOCK_OPT_READAHEAD,
 621             .type = QEMU_OPT_SIZE,
 622             .help = "Readahead size",
 623         },
 624         {
 625             .name = CURL_BLOCK_OPT_SSLVERIFY,
 626             .type = QEMU_OPT_BOOL,
 627             .help = "Verify SSL certificate"
 628         },
 629         {
 630             .name = CURL_BLOCK_OPT_TIMEOUT,
 631             .type = QEMU_OPT_NUMBER,
 632             .help = "Curl timeout"
 633         },
 634         {
 635             .name = CURL_BLOCK_OPT_COOKIE,
 636             .type = QEMU_OPT_STRING,
 637             .help = "Pass the cookie or list of cookies with each request"
 638         },
 639         {
 640             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
 641             .type = QEMU_OPT_STRING,
 642             .help = "ID of secret used as cookie passed with each request"
 643         },
 644         {
 645             .name = CURL_BLOCK_OPT_USERNAME,
 646             .type = QEMU_OPT_STRING,
 647             .help = "Username for HTTP auth"
 648         },
 649         {
 650             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 651             .type = QEMU_OPT_STRING,
 652             .help = "ID of secret used as password for HTTP auth",
 653         },
 654         {
 655             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 656             .type = QEMU_OPT_STRING,
 657             .help = "Username for HTTP proxy auth"
 658         },
 659         {
 660             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 661             .type = QEMU_OPT_STRING,
 662             .help = "ID of secret used as password for HTTP proxy auth",
 663         },
 664         { /* end of list */ }
 665     },
 666 };
 667
 668
 669 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 670                      Error **errp)
 671 {
 672     BDRVCURLState *s = bs->opaque;
 673     CURLState *state = NULL;
 674     QemuOpts *opts;
 675     Error *local_err = NULL;
 676     const char *file;
 677     const char *cookie;
 678     const char *cookie_secret;
 679     double d;
 680     const char *secretid;
 681     const char *protocol_delimiter;
 682     int ret;
 683
 684
 685     if (flags & BDRV_O_RDWR) {
 686         error_setg(errp, "curl block device does not support writes");
 687         return -EROFS;
 688     }
 689
 690     if (!libcurl_initialized) {
 691         ret = curl_global_init(CURL_GLOBAL_ALL);
 692         if (ret) {
 693             error_setg(errp, "libcurl initialization failed with %d", ret);
 694             return -EIO;
 695         }
 696         libcurl_initialized = true;
 697     }
 698
 699     qemu_mutex_init(&s->mutex);
 700     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 701     qemu_opts_absorb_qdict(opts, options, &local_err);
 702     if (local_err) {
 703         error_propagate(errp, local_err);
 704         goto out_noclean;
 705     }
 706
 707     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 708                                           READ_AHEAD_DEFAULT);
 709     if ((s->readahead_size & 0x1ff) != 0) {
 710         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 711                    s->readahead_size);
 712         goto out_noclean;
 713     }
 714
 715     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 716                                      CURL_TIMEOUT_DEFAULT);
 717     if (s->timeout > CURL_TIMEOUT_MAX) {
 718         error_setg(errp, "timeout parameter is too large or negative");
 719         goto out_noclean;
 720     }
 721
 722     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
 723
 724     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 725     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
 726
 727     if (cookie && cookie_secret) {
 728         error_setg(errp,
 729                    "curl driver cannot handle both cookie and cookie secret");
 730         goto out_noclean;
 731     }
 732
 733     if (cookie_secret) {
 734         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
 735         if (!s->cookie) {
 736             goto out_noclean;
 737         }
 738     } else {
 739         s->cookie = g_strdup(cookie);
 740     }
 741
 742     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 743     if (file == NULL) {
 744         error_setg(errp, "curl block driver requires an 'url' option");
 745         goto out_noclean;
 746     }
 747
 748     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
 749         !strstart(protocol_delimiter, "://", NULL))
 750     {
 751         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
 752                    "start with '%s://')", bs->drv->protocol_name, file,
 753                    bs->drv->protocol_name);
 754         goto out_noclean;
 755     }
 756
 757     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 758     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 759
 760     if (secretid) {
 761         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 762         if (!s->password) {
 763             goto out_noclean;
 764         }
 765     }
 766
 767     s->proxyusername = g_strdup(
 768         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 769     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 770     if (secretid) {
 771         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 772         if (!s->proxypassword) {
 773             goto out_noclean;
 774         }
 775     }
 776
 777     DPRINTF("CURL: Opening %s\n", file);
 778     qemu_co_queue_init(&s->free_state_waitq);
 779     s->aio_context = bdrv_get_aio_context(bs);
 780     s->url = g_strdup(file);
 781     qemu_mutex_lock(&s->mutex);
 782     state = curl_find_state(s);
 783     qemu_mutex_unlock(&s->mutex);
 784     if (!state) {
 785         goto out_noclean;
 786     }
 787
 788     // Get file size
 789
 790     if (curl_init_state(s, state) < 0) {
 791         goto out;
 792     }
 793
 794     s->accept_range = false;
 795     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 796     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 797                      curl_header_cb);
 798     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 799     if (curl_easy_perform(state->curl))
 800         goto out;
 801     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
 802         goto out;
 803     }
 804     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
 805      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
 806      * known and zero if it is realy zero-length file. */
 807 #if LIBCURL_VERSION_NUM >= 0x071304
 808     if (d < 0) {
 809         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 810                 "Server didn't report file size.");
 811         goto out;
 812     }
 813 #else
 814     if (d <= 0) {
 815         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 816                 "Unknown file size or zero-length file.");
 817         goto out;
 818     }
 819 #endif
 820
 821     s->len = d;
 822
 823     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 824         || !strncasecmp(s->url, "https://", strlen("https://")))
 825         && !s->accept_range) {
 826         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 827                 "Server does not support 'range' (byte ranges).");
 828         goto out;
 829     }
 830     DPRINTF("CURL: Size = %" PRIu64 "\n", s->len);
 831
 832     qemu_mutex_lock(&s->mutex);
 833     curl_clean_state(state);
 834     qemu_mutex_unlock(&s->mutex);
 835     curl_easy_cleanup(state->curl);
 836     state->curl = NULL;
 837
 838     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 839
 840     qemu_opts_del(opts);
 841     return 0;
 842
 843 out:
 844     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 845     curl_easy_cleanup(state->curl);
 846     state->curl = NULL;
 847 out_noclean:
 848     qemu_mutex_destroy(&s->mutex);
 849     g_free(s->cookie);
 850     g_free(s->url);
 851     g_free(s->username);
 852     g_free(s->proxyusername);
 853     g_free(s->proxypassword);
 854     qemu_opts_del(opts);
 855     return -EINVAL;
 856 }
 857
 858 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
 859 {
 860     CURLState *state;
 861     int running;
 862
 863     BDRVCURLState *s = bs->opaque;
 864
 865     uint64_t start = acb->offset;
 866     uint64_t end;
 867
 868     qemu_mutex_lock(&s->mutex);
 869
 870     // In case we have the requested data already (e.g. read-ahead),
 871     // we can just call the callback and be done.
 872     if (curl_find_buf(s, start, acb->bytes, acb)) {
 873         goto out;
 874     }
 875
 876     // No cache found, so let's start a new request
 877     for (;;) {
 878         state = curl_find_state(s);
 879         if (state) {
 880             break;
 881         }
 882         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
 883     }
 884
 885     if (curl_init_state(s, state) < 0) {
 886         curl_clean_state(state);
 887         acb->ret = -EIO;
 888         goto out;
 889     }
 890
 891     acb->start = 0;
 892     acb->end = MIN(acb->bytes, s->len - start);
 893
 894     state->buf_off = 0;
 895     g_free(state->orig_buf);
 896     state->buf_start = start;
 897     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
 898     end = start + state->buf_len - 1;
 899     state->orig_buf = g_try_malloc(state->buf_len);
 900     if (state->buf_len && state->orig_buf == NULL) {
 901         curl_clean_state(state);
 902         acb->ret = -ENOMEM;
 903         goto out;
 904     }
 905     state->acb[0] = acb;
 906
 907     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
 908     DPRINTF("CURL (AIO): Reading %" PRIu64 " at %" PRIu64 " (%s)\n",
 909             acb->bytes, start, state->range);
 910     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 911
 912     curl_multi_add_handle(s->multi, state->curl);
 913
 914     /* Tell curl it needs to kick things off */
 915     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 916
 917 out:
 918     qemu_mutex_unlock(&s->mutex);
 919 }
 920
 921 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
 922         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
 923 {
 924     CURLAIOCB acb = {
 925         .co = qemu_coroutine_self(),
 926         .ret = -EINPROGRESS,
 927         .qiov = qiov,
 928         .offset = offset,
 929         .bytes = bytes
 930     };
 931
 932     curl_setup_preadv(bs, &acb);
 933     while (acb.ret == -EINPROGRESS) {
 934         qemu_coroutine_yield();
 935     }
 936     return acb.ret;
 937 }
 938
 939 static void curl_close(BlockDriverState *bs)
 940 {
 941     BDRVCURLState *s = bs->opaque;
 942
 943     DPRINTF("CURL: Close\n");
 944     curl_detach_aio_context(bs);
 945     qemu_mutex_destroy(&s->mutex);
 946
 947     g_free(s->cookie);
 948     g_free(s->url);
 949     g_free(s->username);
 950     g_free(s->proxyusername);
 951     g_free(s->proxypassword);
 952 }
 953
 954 static int64_t curl_getlength(BlockDriverState *bs)
 955 {
 956     BDRVCURLState *s = bs->opaque;
 957     return s->len;
 958 }
 959
 960 static BlockDriver bdrv_http = {
 961     .format_name                = "http",
 962     .protocol_name              = "http",
 963
 964     .instance_size              = sizeof(BDRVCURLState),
 965     .bdrv_parse_filename        = curl_parse_filename,
 966     .bdrv_file_open             = curl_open,
 967     .bdrv_close                 = curl_close,
 968     .bdrv_getlength             = curl_getlength,
 969
 970     .bdrv_co_preadv             = curl_co_preadv,
 971
 972     .bdrv_detach_aio_context    = curl_detach_aio_context,
 973     .bdrv_attach_aio_context    = curl_attach_aio_context,
 974 };
 975
 976 static BlockDriver bdrv_https = {
 977     .format_name                = "https",
 978     .protocol_name              = "https",
 979
 980     .instance_size              = sizeof(BDRVCURLState),
 981     .bdrv_parse_filename        = curl_parse_filename,
 982     .bdrv_file_open             = curl_open,
 983     .bdrv_close                 = curl_close,
 984     .bdrv_getlength             = curl_getlength,
 985
 986     .bdrv_co_preadv             = curl_co_preadv,
 987
 988     .bdrv_detach_aio_context    = curl_detach_aio_context,
 989     .bdrv_attach_aio_context    = curl_attach_aio_context,
 990 };
 991
 992 static BlockDriver bdrv_ftp = {
 993     .format_name                = "ftp",
 994     .protocol_name              = "ftp",
 995
 996     .instance_size              = sizeof(BDRVCURLState),
 997     .bdrv_parse_filename        = curl_parse_filename,
 998     .bdrv_file_open             = curl_open,
 999     .bdrv_close                 = curl_close,
1000     .bdrv_getlength             = curl_getlength,
1001
1002     .bdrv_co_preadv             = curl_co_preadv,
1003
1004     .bdrv_detach_aio_context    = curl_detach_aio_context,
1005     .bdrv_attach_aio_context    = curl_attach_aio_context,
1006 };
1007
1008 static BlockDriver bdrv_ftps = {
1009     .format_name                = "ftps",
1010     .protocol_name              = "ftps",
1011
1012     .instance_size              = sizeof(BDRVCURLState),
1013     .bdrv_parse_filename        = curl_parse_filename,
1014     .bdrv_file_open             = curl_open,
1015     .bdrv_close                 = curl_close,
1016     .bdrv_getlength             = curl_getlength,
1017
1018     .bdrv_co_preadv             = curl_co_preadv,
1019
1020     .bdrv_detach_aio_context    = curl_detach_aio_context,
1021     .bdrv_attach_aio_context    = curl_attach_aio_context,
1022 };
1023
1024 static void curl_block_init(void)
1025 {
1026     bdrv_register(&bdrv_http);
1027     bdrv_register(&bdrv_https);
1028     bdrv_register(&bdrv_ftp);
1029     bdrv_register(&bdrv_ftps);
1030 }
1031
1032 block_init(curl_block_init);