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
  25 #include "qemu/osdep.h"
  26 #include "qapi/error.h"
  27 #include "qemu/error-report.h"
  28 #include "qemu/option.h"
  29 #include "block/block_int.h"
  30 #include "qapi/qmp/qdict.h"
  31 #include "qapi/qmp/qstring.h"
  32 #include "crypto/secret.h"
  33 #include <curl/curl.h>
  34 #include "qemu/cutils.h"
  35
  36 // #define DEBUG_CURL
  37 // #define DEBUG_VERBOSE
  38
  39 #ifdef DEBUG_CURL
  40 #define DEBUG_CURL_PRINT 1
  41 #else
  42 #define DEBUG_CURL_PRINT 0
  43 #endif
  44 #define DPRINTF(fmt, ...)                                            \
  45     do {                                                             \
  46         if (DEBUG_CURL_PRINT) {                                      \
  47             fprintf(stderr, fmt, ## __VA_ARGS__);                    \
  48         }                                                            \
  49     } while (0)
  50
  51 #if LIBCURL_VERSION_NUM >= 0x071000
  52 /* The multi interface timer callback was introduced in 7.16.0 */
  53 #define NEED_CURL_TIMER_CALLBACK
  54 #define HAVE_SOCKET_ACTION
  55 #endif
  56
  57 #ifndef HAVE_SOCKET_ACTION
  58 /* If curl_multi_socket_action isn't available, define it statically here in
  59  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
  60  * less efficient but still safe. */
  61 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
  62                                             curl_socket_t sockfd,
  63                                             int ev_bitmask,
  64                                             int *running_handles)
  65 {
  66     return curl_multi_socket(multi_handle, sockfd, running_handles);
  67 }
  68 #define curl_multi_socket_action __curl_multi_socket_action
  69 #endif
  70
  71 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  72                    CURLPROTO_FTP | CURLPROTO_FTPS)
  73
  74 #define CURL_NUM_STATES 8
  75 #define CURL_NUM_ACB    8
  76 #define READ_AHEAD_DEFAULT (256 * 1024)
  77 #define CURL_TIMEOUT_DEFAULT 5
  78 #define CURL_TIMEOUT_MAX 10000
  79
  80 #define CURL_BLOCK_OPT_URL       "url"
  81 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  82 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  83 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
  84 #define CURL_BLOCK_OPT_COOKIE    "cookie"
  85 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
  86 #define CURL_BLOCK_OPT_USERNAME "username"
  87 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
  88 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
  89 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
  90
  91 struct BDRVCURLState;
  92
  93 static bool libcurl_initialized;
  94
  95 typedef struct CURLAIOCB {
  96     Coroutine *co;
  97     QEMUIOVector *qiov;
  98
  99     uint64_t offset;
 100     uint64_t bytes;
 101     int ret;
 102
 103     size_t start;
 104     size_t end;
 105 } CURLAIOCB;
 106
 107 typedef struct CURLSocket {
 108     int fd;
 109     QLIST_ENTRY(CURLSocket) next;
 110 } CURLSocket;
 111
 112 typedef struct CURLState
 113 {
 114     struct BDRVCURLState *s;
 115     CURLAIOCB *acb[CURL_NUM_ACB];
 116     CURL *curl;
 117     QLIST_HEAD(, CURLSocket) sockets;
 118     char *orig_buf;
 119     uint64_t buf_start;
 120     size_t buf_off;
 121     size_t buf_len;
 122     char range[128];
 123     char errmsg[CURL_ERROR_SIZE];
 124     char in_use;
 125 } CURLState;
 126
 127 typedef struct BDRVCURLState {
 128     CURLM *multi;
 129     QEMUTimer timer;
 130     uint64_t len;
 131     CURLState states[CURL_NUM_STATES];
 132     char *url;
 133     size_t readahead_size;
 134     bool sslverify;
 135     uint64_t timeout;
 136     char *cookie;
 137     bool accept_range;
 138     AioContext *aio_context;
 139     QemuMutex mutex;
 140     CoQueue free_state_waitq;
 141     char *username;
 142     char *password;
 143     char *proxyusername;
 144     char *proxypassword;
 145 } BDRVCURLState;
 146
 147 static void curl_clean_state(CURLState *s);
 148 static void curl_multi_do(void *arg);
 149 static void curl_multi_read(void *arg);
 150
 151 #ifdef NEED_CURL_TIMER_CALLBACK
 152 /* Called from curl_multi_do_locked, with s->mutex held.  */
 153 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 154 {
 155     BDRVCURLState *s = opaque;
 156
 157     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
 158     if (timeout_ms == -1) {
 159         timer_del(&s->timer);
 160     } else {
 161         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 162         timer_mod(&s->timer,
 163                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 164     }
 165     return 0;
 166 }
 167 #endif
 168
 169 /* Called from curl_multi_do_locked, with s->mutex held.  */
 170 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 171                         void *userp, void *sp)
 172 {
 173     BDRVCURLState *s;
 174     CURLState *state = NULL;
 175     CURLSocket *socket;
 176
 177     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 178     s = state->s;
 179
 180     QLIST_FOREACH(socket, &state->sockets, next) {
 181         if (socket->fd == fd) {
 182             if (action == CURL_POLL_REMOVE) {
 183                 QLIST_REMOVE(socket, next);
 184                 g_free(socket);
 185             }
 186             break;
 187         }
 188     }
 189     if (!socket) {
 190         socket = g_new0(CURLSocket, 1);
 191         socket->fd = fd;
 192         QLIST_INSERT_HEAD(&state->sockets, socket, next);
 193     }
 194     socket = NULL;
 195
 196     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, (int)fd);
 197     switch (action) {
 198         case CURL_POLL_IN:
 199             aio_set_fd_handler(s->aio_context, fd, false,
 200                                curl_multi_read, NULL, NULL, state);
 201             break;
 202         case CURL_POLL_OUT:
 203             aio_set_fd_handler(s->aio_context, fd, false,
 204                                NULL, curl_multi_do, NULL, state);
 205             break;
 206         case CURL_POLL_INOUT:
 207             aio_set_fd_handler(s->aio_context, fd, false,
 208                                curl_multi_read, curl_multi_do, NULL, state);
 209             break;
 210         case CURL_POLL_REMOVE:
 211             aio_set_fd_handler(s->aio_context, fd, false,
 212                                NULL, NULL, NULL, NULL);
 213             break;
 214     }
 215
 216     return 0;
 217 }
 218
 219 /* Called from curl_multi_do_locked, with s->mutex held.  */
 220 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 221 {
 222     BDRVCURLState *s = opaque;
 223     size_t realsize = size * nmemb;
 224     const char *accept_line = "Accept-Ranges: bytes";
 225
 226     if (realsize >= strlen(accept_line)
 227         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
 228         s->accept_range = true;
 229     }
 230
 231     return realsize;
 232 }
 233
 234 /* Called from curl_multi_do_locked, with s->mutex held.  */
 235 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 236 {
 237     CURLState *s = ((CURLState*)opaque);
 238     size_t realsize = size * nmemb;
 239     int i;
 240
 241     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
 242
 243     if (!s || !s->orig_buf) {
 244         goto read_end;
 245     }
 246
 247     if (s->buf_off >= s->buf_len) {
 248         /* buffer full, read nothing */
 249         goto read_end;
 250     }
 251     realsize = MIN(realsize, s->buf_len - s->buf_off);
 252     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 253     s->buf_off += realsize;
 254
 255     for(i=0; i<CURL_NUM_ACB; i++) {
 256         CURLAIOCB *acb = s->acb[i];
 257
 258         if (!acb)
 259             continue;
 260
 261         if ((s->buf_off >= acb->end)) {
 262             size_t request_length = acb->bytes;
 263
 264             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
 265                                 acb->end - acb->start);
 266
 267             if (acb->end - acb->start < request_length) {
 268                 size_t offset = acb->end - acb->start;
 269                 qemu_iovec_memset(acb->qiov, offset, 0,
 270                                   request_length - offset);
 271             }
 272
 273             acb->ret = 0;
 274             s->acb[i] = NULL;
 275             qemu_mutex_unlock(&s->s->mutex);
 276             aio_co_wake(acb->co);
 277             qemu_mutex_lock(&s->s->mutex);
 278         }
 279     }
 280
 281 read_end:
 282     /* curl will error out if we do not return this value */
 283     return size * nmemb;
 284 }
 285
 286 /* Called with s->mutex held.  */
 287 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
 288                           CURLAIOCB *acb)
 289 {
 290     int i;
 291     uint64_t end = start + len;
 292     uint64_t clamped_end = MIN(end, s->len);
 293     uint64_t clamped_len = clamped_end - start;
 294
 295     for (i=0; i<CURL_NUM_STATES; i++) {
 296         CURLState *state = &s->states[i];
 297         uint64_t buf_end = (state->buf_start + state->buf_off);
 298         uint64_t buf_fend = (state->buf_start + state->buf_len);
 299
 300         if (!state->orig_buf)
 301             continue;
 302         if (!state->buf_off)
 303             continue;
 304
 305         // Does the existing buffer cover our section?
 306         if ((start >= state->buf_start) &&
 307             (start <= buf_end) &&
 308             (clamped_end >= state->buf_start) &&
 309             (clamped_end <= buf_end))
 310         {
 311             char *buf = state->orig_buf + (start - state->buf_start);
 312
 313             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
 314             if (clamped_len < len) {
 315                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
 316             }
 317             acb->ret = 0;
 318             return true;
 319         }
 320
 321         // Wait for unfinished chunks
 322         if (state->in_use &&
 323             (start >= state->buf_start) &&
 324             (start <= buf_fend) &&
 325             (clamped_end >= state->buf_start) &&
 326             (clamped_end <= buf_fend))
 327         {
 328             int j;
 329
 330             acb->start = start - state->buf_start;
 331             acb->end = acb->start + clamped_len;
 332
 333             for (j=0; j<CURL_NUM_ACB; j++) {
 334                 if (!state->acb[j]) {
 335                     state->acb[j] = acb;
 336                     return true;
 337                 }
 338             }
 339         }
 340     }
 341
 342     return false;
 343 }
 344
 345 /* Called with s->mutex held.  */
 346 static void curl_multi_check_completion(BDRVCURLState *s)
 347 {
 348     int msgs_in_queue;
 349
 350     /* Try to find done transfers, so we can free the easy
 351      * handle again. */
 352     for (;;) {
 353         CURLMsg *msg;
 354         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 355
 356         /* Quit when there are no more completions */
 357         if (!msg)
 358             break;
 359
 360         if (msg->msg == CURLMSG_DONE) {
 361             CURLState *state = NULL;
 362             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 363                               (char **)&state);
 364
 365             /* ACBs for successful messages get completed in curl_read_cb */
 366             if (msg->data.result != CURLE_OK) {
 367                 int i;
 368                 static int errcount = 100;
 369
 370                 /* Don't lose the original error message from curl, since
 371                  * it contains extra data.
 372                  */
 373                 if (errcount > 0) {
 374                     error_report("curl: %s", state->errmsg);
 375                     if (--errcount == 0) {
 376                         error_report("curl: further errors suppressed");
 377                     }
 378                 }
 379
 380                 for (i = 0; i < CURL_NUM_ACB; i++) {
 381                     CURLAIOCB *acb = state->acb[i];
 382
 383                     if (acb == NULL) {
 384                         continue;
 385                     }
 386
 387                     acb->ret = -EIO;
 388                     state->acb[i] = NULL;
 389                     qemu_mutex_unlock(&s->mutex);
 390                     aio_co_wake(acb->co);
 391                     qemu_mutex_lock(&s->mutex);
 392                 }
 393             }
 394
 395             curl_clean_state(state);
 396             break;
 397         }
 398     }
 399 }
 400
 401 /* Called with s->mutex held.  */
 402 static void curl_multi_do_locked(CURLState *s)
 403 {
 404     CURLSocket *socket, *next_socket;
 405     int running;
 406     int r;
 407
 408     if (!s->s->multi) {
 409         return;
 410     }
 411
 412     /* Need to use _SAFE because curl_multi_socket_action() may trigger
 413      * curl_sock_cb() which might modify this list */
 414     QLIST_FOREACH_SAFE(socket, &s->sockets, next, next_socket) {
 415         do {
 416             r = curl_multi_socket_action(s->s->multi, socket->fd, 0, &running);
 417         } while (r == CURLM_CALL_MULTI_PERFORM);
 418     }
 419 }
 420
 421 static void curl_multi_do(void *arg)
 422 {
 423     CURLState *s = (CURLState *)arg;
 424
 425     qemu_mutex_lock(&s->s->mutex);
 426     curl_multi_do_locked(s);
 427     qemu_mutex_unlock(&s->s->mutex);
 428 }
 429
 430 static void curl_multi_read(void *arg)
 431 {
 432     CURLState *s = (CURLState *)arg;
 433
 434     qemu_mutex_lock(&s->s->mutex);
 435     curl_multi_do_locked(s);
 436     curl_multi_check_completion(s->s);
 437     qemu_mutex_unlock(&s->s->mutex);
 438 }
 439
 440 static void curl_multi_timeout_do(void *arg)
 441 {
 442 #ifdef NEED_CURL_TIMER_CALLBACK
 443     BDRVCURLState *s = (BDRVCURLState *)arg;
 444     int running;
 445
 446     if (!s->multi) {
 447         return;
 448     }
 449
 450     qemu_mutex_lock(&s->mutex);
 451     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 452
 453     curl_multi_check_completion(s);
 454     qemu_mutex_unlock(&s->mutex);
 455 #else
 456     abort();
 457 #endif
 458 }
 459
 460 /* Called with s->mutex held.  */
 461 static CURLState *curl_find_state(BDRVCURLState *s)
 462 {
 463     CURLState *state = NULL;
 464     int i;
 465
 466     for (i = 0; i < CURL_NUM_STATES; i++) {
 467         if (!s->states[i].in_use) {
 468             state = &s->states[i];
 469             state->in_use = 1;
 470             break;
 471         }
 472     }
 473     return state;
 474 }
 475
 476 static int curl_init_state(BDRVCURLState *s, CURLState *state)
 477 {
 478     if (!state->curl) {
 479         state->curl = curl_easy_init();
 480         if (!state->curl) {
 481             return -EIO;
 482         }
 483         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 484         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 485                          (long) s->sslverify);
 486         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
 487                          s->sslverify ? 2L : 0L);
 488         if (s->cookie) {
 489             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
 490         }
 491         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
 492         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 493                          (void *)curl_read_cb);
 494         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 495         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 496         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 497         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 498         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 499         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 500         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 501
 502         if (s->username) {
 503             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
 504         }
 505         if (s->password) {
 506             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
 507         }
 508         if (s->proxyusername) {
 509             curl_easy_setopt(state->curl,
 510                              CURLOPT_PROXYUSERNAME, s->proxyusername);
 511         }
 512         if (s->proxypassword) {
 513             curl_easy_setopt(state->curl,
 514                              CURLOPT_PROXYPASSWORD, s->proxypassword);
 515         }
 516
 517         /* Restrict supported protocols to avoid security issues in the more
 518          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 519          * CVE-2013-0249.
 520          *
 521          * Restricting protocols is only supported from 7.19.4 upwards.
 522          */
 523 #if LIBCURL_VERSION_NUM >= 0x071304
 524         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 525         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 526 #endif
 527
 528 #ifdef DEBUG_VERBOSE
 529         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 530 #endif
 531     }
 532
 533     QLIST_INIT(&state->sockets);
 534     state->s = s;
 535
 536     return 0;
 537 }
 538
 539 /* Called with s->mutex held.  */
 540 static void curl_clean_state(CURLState *s)
 541 {
 542     int j;
 543     for (j = 0; j < CURL_NUM_ACB; j++) {
 544         assert(!s->acb[j]);
 545     }
 546
 547     if (s->s->multi)
 548         curl_multi_remove_handle(s->s->multi, s->curl);
 549
 550     while (!QLIST_EMPTY(&s->sockets)) {
 551         CURLSocket *socket = QLIST_FIRST(&s->sockets);
 552
 553         QLIST_REMOVE(socket, next);
 554         g_free(socket);
 555     }
 556
 557     s->in_use = 0;
 558
 559     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
 560 }
 561
 562 static void curl_parse_filename(const char *filename, QDict *options,
 563                                 Error **errp)
 564 {
 565     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
 566 }
 567
 568 static void curl_detach_aio_context(BlockDriverState *bs)
 569 {
 570     BDRVCURLState *s = bs->opaque;
 571     int i;
 572
 573     qemu_mutex_lock(&s->mutex);
 574     for (i = 0; i < CURL_NUM_STATES; i++) {
 575         if (s->states[i].in_use) {
 576             curl_clean_state(&s->states[i]);
 577         }
 578         if (s->states[i].curl) {
 579             curl_easy_cleanup(s->states[i].curl);
 580             s->states[i].curl = NULL;
 581         }
 582         g_free(s->states[i].orig_buf);
 583         s->states[i].orig_buf = NULL;
 584     }
 585     if (s->multi) {
 586         curl_multi_cleanup(s->multi);
 587         s->multi = NULL;
 588     }
 589     qemu_mutex_unlock(&s->mutex);
 590
 591     timer_del(&s->timer);
 592 }
 593
 594 static void curl_attach_aio_context(BlockDriverState *bs,
 595                                     AioContext *new_context)
 596 {
 597     BDRVCURLState *s = bs->opaque;
 598
 599     aio_timer_init(new_context, &s->timer,
 600                    QEMU_CLOCK_REALTIME, SCALE_NS,
 601                    curl_multi_timeout_do, s);
 602
 603     assert(!s->multi);
 604     s->multi = curl_multi_init();
 605     s->aio_context = new_context;
 606     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 607 #ifdef NEED_CURL_TIMER_CALLBACK
 608     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 609     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 610 #endif
 611 }
 612
 613 static QemuOptsList runtime_opts = {
 614     .name = "curl",
 615     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 616     .desc = {
 617         {
 618             .name = CURL_BLOCK_OPT_URL,
 619             .type = QEMU_OPT_STRING,
 620             .help = "URL to open",
 621         },
 622         {
 623             .name = CURL_BLOCK_OPT_READAHEAD,
 624             .type = QEMU_OPT_SIZE,
 625             .help = "Readahead size",
 626         },
 627         {
 628             .name = CURL_BLOCK_OPT_SSLVERIFY,
 629             .type = QEMU_OPT_BOOL,
 630             .help = "Verify SSL certificate"
 631         },
 632         {
 633             .name = CURL_BLOCK_OPT_TIMEOUT,
 634             .type = QEMU_OPT_NUMBER,
 635             .help = "Curl timeout"
 636         },
 637         {
 638             .name = CURL_BLOCK_OPT_COOKIE,
 639             .type = QEMU_OPT_STRING,
 640             .help = "Pass the cookie or list of cookies with each request"
 641         },
 642         {
 643             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
 644             .type = QEMU_OPT_STRING,
 645             .help = "ID of secret used as cookie passed with each request"
 646         },
 647         {
 648             .name = CURL_BLOCK_OPT_USERNAME,
 649             .type = QEMU_OPT_STRING,
 650             .help = "Username for HTTP auth"
 651         },
 652         {
 653             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 654             .type = QEMU_OPT_STRING,
 655             .help = "ID of secret used as password for HTTP auth",
 656         },
 657         {
 658             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 659             .type = QEMU_OPT_STRING,
 660             .help = "Username for HTTP proxy auth"
 661         },
 662         {
 663             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 664             .type = QEMU_OPT_STRING,
 665             .help = "ID of secret used as password for HTTP proxy auth",
 666         },
 667         { /* end of list */ }
 668     },
 669 };
 670
 671
 672 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 673                      Error **errp)
 674 {
 675     BDRVCURLState *s = bs->opaque;
 676     CURLState *state = NULL;
 677     QemuOpts *opts;
 678     Error *local_err = NULL;
 679     const char *file;
 680     const char *cookie;
 681     const char *cookie_secret;
 682     double d;
 683     const char *secretid;
 684     const char *protocol_delimiter;
 685     int ret;
 686
 687
 688     if (flags & BDRV_O_RDWR) {
 689         error_setg(errp, "curl block device does not support writes");
 690         return -EROFS;
 691     }
 692
 693     if (!libcurl_initialized) {
 694         ret = curl_global_init(CURL_GLOBAL_ALL);
 695         if (ret) {
 696             error_setg(errp, "libcurl initialization failed with %d", ret);
 697             return -EIO;
 698         }
 699         libcurl_initialized = true;
 700     }
 701
 702     qemu_mutex_init(&s->mutex);
 703     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 704     qemu_opts_absorb_qdict(opts, options, &local_err);
 705     if (local_err) {
 706         error_propagate(errp, local_err);
 707         goto out_noclean;
 708     }
 709
 710     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 711                                           READ_AHEAD_DEFAULT);
 712     if ((s->readahead_size & 0x1ff) != 0) {
 713         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 714                    s->readahead_size);
 715         goto out_noclean;
 716     }
 717
 718     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 719                                      CURL_TIMEOUT_DEFAULT);
 720     if (s->timeout > CURL_TIMEOUT_MAX) {
 721         error_setg(errp, "timeout parameter is too large or negative");
 722         goto out_noclean;
 723     }
 724
 725     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
 726
 727     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 728     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
 729
 730     if (cookie && cookie_secret) {
 731         error_setg(errp,
 732                    "curl driver cannot handle both cookie and cookie secret");
 733         goto out_noclean;
 734     }
 735
 736     if (cookie_secret) {
 737         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
 738         if (!s->cookie) {
 739             goto out_noclean;
 740         }
 741     } else {
 742         s->cookie = g_strdup(cookie);
 743     }
 744
 745     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 746     if (file == NULL) {
 747         error_setg(errp, "curl block driver requires an 'url' option");
 748         goto out_noclean;
 749     }
 750
 751     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
 752         !strstart(protocol_delimiter, "://", NULL))
 753     {
 754         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
 755                    "start with '%s://')", bs->drv->protocol_name, file,
 756                    bs->drv->protocol_name);
 757         goto out_noclean;
 758     }
 759
 760     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 761     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 762
 763     if (secretid) {
 764         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 765         if (!s->password) {
 766             goto out_noclean;
 767         }
 768     }
 769
 770     s->proxyusername = g_strdup(
 771         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 772     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 773     if (secretid) {
 774         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 775         if (!s->proxypassword) {
 776             goto out_noclean;
 777         }
 778     }
 779
 780     DPRINTF("CURL: Opening %s\n", file);
 781     qemu_co_queue_init(&s->free_state_waitq);
 782     s->aio_context = bdrv_get_aio_context(bs);
 783     s->url = g_strdup(file);
 784     qemu_mutex_lock(&s->mutex);
 785     state = curl_find_state(s);
 786     qemu_mutex_unlock(&s->mutex);
 787     if (!state) {
 788         goto out_noclean;
 789     }
 790
 791     // Get file size
 792
 793     if (curl_init_state(s, state) < 0) {
 794         goto out;
 795     }
 796
 797     s->accept_range = false;
 798     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 799     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 800                      curl_header_cb);
 801     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 802     if (curl_easy_perform(state->curl))
 803         goto out;
 804     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
 805         goto out;
 806     }
 807     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
 808      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
 809      * known and zero if it is really zero-length file. */
 810 #if LIBCURL_VERSION_NUM >= 0x071304
 811     if (d < 0) {
 812         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 813                 "Server didn't report file size.");
 814         goto out;
 815     }
 816 #else
 817     if (d <= 0) {
 818         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 819                 "Unknown file size or zero-length file.");
 820         goto out;
 821     }
 822 #endif
 823
 824     s->len = d;
 825
 826     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 827         || !strncasecmp(s->url, "https://", strlen("https://")))
 828         && !s->accept_range) {
 829         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 830                 "Server does not support 'range' (byte ranges).");
 831         goto out;
 832     }
 833     DPRINTF("CURL: Size = %" PRIu64 "\n", s->len);
 834
 835     qemu_mutex_lock(&s->mutex);
 836     curl_clean_state(state);
 837     qemu_mutex_unlock(&s->mutex);
 838     curl_easy_cleanup(state->curl);
 839     state->curl = NULL;
 840
 841     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 842
 843     qemu_opts_del(opts);
 844     return 0;
 845
 846 out:
 847     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 848     curl_easy_cleanup(state->curl);
 849     state->curl = NULL;
 850 out_noclean:
 851     qemu_mutex_destroy(&s->mutex);
 852     g_free(s->cookie);
 853     g_free(s->url);
 854     g_free(s->username);
 855     g_free(s->proxyusername);
 856     g_free(s->proxypassword);
 857     qemu_opts_del(opts);
 858     return -EINVAL;
 859 }
 860
 861 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
 862 {
 863     CURLState *state;
 864     int running;
 865
 866     BDRVCURLState *s = bs->opaque;
 867
 868     uint64_t start = acb->offset;
 869     uint64_t end;
 870
 871     qemu_mutex_lock(&s->mutex);
 872
 873     // In case we have the requested data already (e.g. read-ahead),
 874     // we can just call the callback and be done.
 875     if (curl_find_buf(s, start, acb->bytes, acb)) {
 876         goto out;
 877     }
 878
 879     // No cache found, so let's start a new request
 880     for (;;) {
 881         state = curl_find_state(s);
 882         if (state) {
 883             break;
 884         }
 885         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
 886     }
 887
 888     if (curl_init_state(s, state) < 0) {
 889         curl_clean_state(state);
 890         acb->ret = -EIO;
 891         goto out;
 892     }
 893
 894     acb->start = 0;
 895     acb->end = MIN(acb->bytes, s->len - start);
 896
 897     state->buf_off = 0;
 898     g_free(state->orig_buf);
 899     state->buf_start = start;
 900     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
 901     end = start + state->buf_len - 1;
 902     state->orig_buf = g_try_malloc(state->buf_len);
 903     if (state->buf_len && state->orig_buf == NULL) {
 904         curl_clean_state(state);
 905         acb->ret = -ENOMEM;
 906         goto out;
 907     }
 908     state->acb[0] = acb;
 909
 910     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
 911     DPRINTF("CURL (AIO): Reading %" PRIu64 " at %" PRIu64 " (%s)\n",
 912             acb->bytes, start, state->range);
 913     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 914
 915     curl_multi_add_handle(s->multi, state->curl);
 916
 917     /* Tell curl it needs to kick things off */
 918     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 919
 920 out:
 921     qemu_mutex_unlock(&s->mutex);
 922 }
 923
 924 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
 925         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
 926 {
 927     CURLAIOCB acb = {
 928         .co = qemu_coroutine_self(),
 929         .ret = -EINPROGRESS,
 930         .qiov = qiov,
 931         .offset = offset,
 932         .bytes = bytes
 933     };
 934
 935     curl_setup_preadv(bs, &acb);
 936     while (acb.ret == -EINPROGRESS) {
 937         qemu_coroutine_yield();
 938     }
 939     return acb.ret;
 940 }
 941
 942 static void curl_close(BlockDriverState *bs)
 943 {
 944     BDRVCURLState *s = bs->opaque;
 945
 946     DPRINTF("CURL: Close\n");
 947     curl_detach_aio_context(bs);
 948     qemu_mutex_destroy(&s->mutex);
 949
 950     g_free(s->cookie);
 951     g_free(s->url);
 952     g_free(s->username);
 953     g_free(s->proxyusername);
 954     g_free(s->proxypassword);
 955 }
 956
 957 static int64_t curl_getlength(BlockDriverState *bs)
 958 {
 959     BDRVCURLState *s = bs->opaque;
 960     return s->len;
 961 }
 962
 963 static BlockDriver bdrv_http = {
 964     .format_name                = "http",
 965     .protocol_name              = "http",
 966
 967     .instance_size              = sizeof(BDRVCURLState),
 968     .bdrv_parse_filename        = curl_parse_filename,
 969     .bdrv_file_open             = curl_open,
 970     .bdrv_close                 = curl_close,
 971     .bdrv_getlength             = curl_getlength,
 972
 973     .bdrv_co_preadv             = curl_co_preadv,
 974
 975     .bdrv_detach_aio_context    = curl_detach_aio_context,
 976     .bdrv_attach_aio_context    = curl_attach_aio_context,
 977 };
 978
 979 static BlockDriver bdrv_https = {
 980     .format_name                = "https",
 981     .protocol_name              = "https",
 982
 983     .instance_size              = sizeof(BDRVCURLState),
 984     .bdrv_parse_filename        = curl_parse_filename,
 985     .bdrv_file_open             = curl_open,
 986     .bdrv_close                 = curl_close,
 987     .bdrv_getlength             = curl_getlength,
 988
 989     .bdrv_co_preadv             = curl_co_preadv,
 990
 991     .bdrv_detach_aio_context    = curl_detach_aio_context,
 992     .bdrv_attach_aio_context    = curl_attach_aio_context,
 993 };
 994
 995 static BlockDriver bdrv_ftp = {
 996     .format_name                = "ftp",
 997     .protocol_name              = "ftp",
 998
 999     .instance_size              = sizeof(BDRVCURLState),
1000     .bdrv_parse_filename        = curl_parse_filename,
1001     .bdrv_file_open             = curl_open,
1002     .bdrv_close                 = curl_close,
1003     .bdrv_getlength             = curl_getlength,
1004
1005     .bdrv_co_preadv             = curl_co_preadv,
1006
1007     .bdrv_detach_aio_context    = curl_detach_aio_context,
1008     .bdrv_attach_aio_context    = curl_attach_aio_context,
1009 };
1010
1011 static BlockDriver bdrv_ftps = {
1012     .format_name                = "ftps",
1013     .protocol_name              = "ftps",
1014
1015     .instance_size              = sizeof(BDRVCURLState),
1016     .bdrv_parse_filename        = curl_parse_filename,
1017     .bdrv_file_open             = curl_open,
1018     .bdrv_close                 = curl_close,
1019     .bdrv_getlength             = curl_getlength,
1020
1021     .bdrv_co_preadv             = curl_co_preadv,
1022
1023     .bdrv_detach_aio_context    = curl_detach_aio_context,
1024     .bdrv_attach_aio_context    = curl_attach_aio_context,
1025 };
1026
1027 static void curl_block_init(void)
1028 {
1029     bdrv_register(&bdrv_http);
1030     bdrv_register(&bdrv_https);
1031     bdrv_register(&bdrv_ftp);
1032     bdrv_register(&bdrv_ftps);
1033 }
1034
1035 block_init(curl_block_init);