block/curl.c

   1 /*
   2  * QEMU Block driver for CURL images
   3  *
   4  * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include "qemu/osdep.h"
  26 #include "qapi/error.h"
  27 #include "qemu/error-report.h"
  28 #include "qemu/module.h"
  29 #include "qemu/option.h"
  30 #include "block/block_int.h"
  31 #include "qapi/qmp/qdict.h"
  32 #include "qapi/qmp/qstring.h"
  33 #include "crypto/secret.h"
  34 #include <curl/curl.h>
  35 #include "qemu/cutils.h"
  36 #include "trace.h"
  37
  38 // #define DEBUG_VERBOSE
  39
  40 #if LIBCURL_VERSION_NUM >= 0x071000
  41 /* The multi interface timer callback was introduced in 7.16.0 */
  42 #define NEED_CURL_TIMER_CALLBACK
  43 #define HAVE_SOCKET_ACTION
  44 #endif
  45
  46 #ifndef HAVE_SOCKET_ACTION
  47 /* If curl_multi_socket_action isn't available, define it statically here in
  48  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
  49  * less efficient but still safe. */
  50 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
  51                                             curl_socket_t sockfd,
  52                                             int ev_bitmask,
  53                                             int *running_handles)
  54 {
  55     return curl_multi_socket(multi_handle, sockfd, running_handles);
  56 }
  57 #define curl_multi_socket_action __curl_multi_socket_action
  58 #endif
  59
  60 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  61                    CURLPROTO_FTP | CURLPROTO_FTPS)
  62
  63 #define CURL_NUM_STATES 8
  64 #define CURL_NUM_ACB    8
  65 #define CURL_TIMEOUT_MAX 10000
  66
  67 #define CURL_BLOCK_OPT_URL       "url"
  68 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  69 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  70 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
  71 #define CURL_BLOCK_OPT_COOKIE    "cookie"
  72 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
  73 #define CURL_BLOCK_OPT_USERNAME "username"
  74 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
  75 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
  76 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
  77
  78 #define CURL_BLOCK_OPT_READAHEAD_DEFAULT (256 * 1024)
  79 #define CURL_BLOCK_OPT_SSLVERIFY_DEFAULT true
  80 #define CURL_BLOCK_OPT_TIMEOUT_DEFAULT 5
  81
  82 struct BDRVCURLState;
  83 struct CURLState;
  84
  85 static bool libcurl_initialized;
  86
  87 typedef struct CURLAIOCB {
  88     Coroutine *co;
  89     QEMUIOVector *qiov;
  90
  91     uint64_t offset;
  92     uint64_t bytes;
  93     int ret;
  94
  95     size_t start;
  96     size_t end;
  97 } CURLAIOCB;
  98
  99 typedef struct CURLSocket {
 100     int fd;
 101     struct CURLState *state;
 102     QLIST_ENTRY(CURLSocket) next;
 103 } CURLSocket;
 104
 105 typedef struct CURLState
 106 {
 107     struct BDRVCURLState *s;
 108     CURLAIOCB *acb[CURL_NUM_ACB];
 109     CURL *curl;
 110     QLIST_HEAD(, CURLSocket) sockets;
 111     char *orig_buf;
 112     uint64_t buf_start;
 113     size_t buf_off;
 114     size_t buf_len;
 115     char range[128];
 116     char errmsg[CURL_ERROR_SIZE];
 117     char in_use;
 118 } CURLState;
 119
 120 typedef struct BDRVCURLState {
 121     CURLM *multi;
 122     QEMUTimer timer;
 123     uint64_t len;
 124     CURLState states[CURL_NUM_STATES];
 125     char *url;
 126     size_t readahead_size;
 127     bool sslverify;
 128     uint64_t timeout;
 129     char *cookie;
 130     bool accept_range;
 131     AioContext *aio_context;
 132     QemuMutex mutex;
 133     CoQueue free_state_waitq;
 134     char *username;
 135     char *password;
 136     char *proxyusername;
 137     char *proxypassword;
 138 } BDRVCURLState;
 139
 140 static void curl_clean_state(CURLState *s);
 141 static void curl_multi_do(void *arg);
 142
 143 #ifdef NEED_CURL_TIMER_CALLBACK
 144 /* Called from curl_multi_do_locked, with s->mutex held.  */
 145 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 146 {
 147     BDRVCURLState *s = opaque;
 148
 149     trace_curl_timer_cb(timeout_ms);
 150     if (timeout_ms == -1) {
 151         timer_del(&s->timer);
 152     } else {
 153         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 154         timer_mod(&s->timer,
 155                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 156     }
 157     return 0;
 158 }
 159 #endif
 160
 161 /* Called from curl_multi_do_locked, with s->mutex held.  */
 162 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 163                         void *userp, void *sp)
 164 {
 165     BDRVCURLState *s;
 166     CURLState *state = NULL;
 167     CURLSocket *socket;
 168
 169     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 170     s = state->s;
 171
 172     QLIST_FOREACH(socket, &state->sockets, next) {
 173         if (socket->fd == fd) {
 174             break;
 175         }
 176     }
 177     if (!socket) {
 178         socket = g_new0(CURLSocket, 1);
 179         socket->fd = fd;
 180         socket->state = state;
 181         QLIST_INSERT_HEAD(&state->sockets, socket, next);
 182     }
 183
 184     trace_curl_sock_cb(action, (int)fd);
 185     switch (action) {
 186         case CURL_POLL_IN:
 187             aio_set_fd_handler(s->aio_context, fd, false,
 188                                curl_multi_do, NULL, NULL, socket);
 189             break;
 190         case CURL_POLL_OUT:
 191             aio_set_fd_handler(s->aio_context, fd, false,
 192                                NULL, curl_multi_do, NULL, socket);
 193             break;
 194         case CURL_POLL_INOUT:
 195             aio_set_fd_handler(s->aio_context, fd, false,
 196                                curl_multi_do, curl_multi_do, NULL, socket);
 197             break;
 198         case CURL_POLL_REMOVE:
 199             aio_set_fd_handler(s->aio_context, fd, false,
 200                                NULL, NULL, NULL, NULL);
 201             break;
 202     }
 203
 204     if (action == CURL_POLL_REMOVE) {
 205         QLIST_REMOVE(socket, next);
 206         g_free(socket);
 207     }
 208
 209     return 0;
 210 }
 211
 212 /* Called from curl_multi_do_locked, with s->mutex held.  */
 213 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 214 {
 215     BDRVCURLState *s = opaque;
 216     size_t realsize = size * nmemb;
 217     const char *header = (char *)ptr;
 218     const char *end = header + realsize;
 219     const char *accept_ranges = "accept-ranges:";
 220     const char *bytes = "bytes";
 221
 222     if (realsize >= strlen(accept_ranges)
 223         && g_ascii_strncasecmp(header, accept_ranges,
 224                                strlen(accept_ranges)) == 0) {
 225
 226         char *p = strchr(header, ':') + 1;
 227
 228         /* Skip whitespace between the header name and value. */
 229         while (p < end && *p && g_ascii_isspace(*p)) {
 230             p++;
 231         }
 232
 233         if (end - p >= strlen(bytes)
 234             && strncmp(p, bytes, strlen(bytes)) == 0) {
 235
 236             /* Check that there is nothing but whitespace after the value. */
 237             p += strlen(bytes);
 238             while (p < end && *p && g_ascii_isspace(*p)) {
 239                 p++;
 240             }
 241
 242             if (p == end || !*p) {
 243                 s->accept_range = true;
 244             }
 245         }
 246     }
 247
 248     return realsize;
 249 }
 250
 251 /* Called from curl_multi_do_locked, with s->mutex held.  */
 252 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 253 {
 254     CURLState *s = ((CURLState*)opaque);
 255     size_t realsize = size * nmemb;
 256
 257     trace_curl_read_cb(realsize);
 258
 259     if (!s || !s->orig_buf) {
 260         goto read_end;
 261     }
 262
 263     if (s->buf_off >= s->buf_len) {
 264         /* buffer full, read nothing */
 265         goto read_end;
 266     }
 267     realsize = MIN(realsize, s->buf_len - s->buf_off);
 268     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 269     s->buf_off += realsize;
 270
 271 read_end:
 272     /* curl will error out if we do not return this value */
 273     return size * nmemb;
 274 }
 275
 276 /* Called with s->mutex held.  */
 277 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
 278                           CURLAIOCB *acb)
 279 {
 280     int i;
 281     uint64_t end = start + len;
 282     uint64_t clamped_end = MIN(end, s->len);
 283     uint64_t clamped_len = clamped_end - start;
 284
 285     for (i=0; i<CURL_NUM_STATES; i++) {
 286         CURLState *state = &s->states[i];
 287         uint64_t buf_end = (state->buf_start + state->buf_off);
 288         uint64_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->ret = 0;
 308             return true;
 309         }
 310
 311         // Wait for unfinished chunks
 312         if (state->in_use &&
 313             (start >= state->buf_start) &&
 314             (start <= buf_fend) &&
 315             (clamped_end >= state->buf_start) &&
 316             (clamped_end <= buf_fend))
 317         {
 318             int j;
 319
 320             acb->start = start - state->buf_start;
 321             acb->end = acb->start + clamped_len;
 322
 323             for (j=0; j<CURL_NUM_ACB; j++) {
 324                 if (!state->acb[j]) {
 325                     state->acb[j] = acb;
 326                     return true;
 327                 }
 328             }
 329         }
 330     }
 331
 332     return false;
 333 }
 334
 335 /* Called with s->mutex held.  */
 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             int i;
 352             CURLState *state = NULL;
 353             bool error = msg->data.result != CURLE_OK;
 354
 355             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 356                               (char **)&state);
 357
 358             if (error) {
 359                 static int errcount = 100;
 360
 361                 /* Don't lose the original error message from curl, since
 362                  * it contains extra data.
 363                  */
 364                 if (errcount > 0) {
 365                     error_report("curl: %s", state->errmsg);
 366                     if (--errcount == 0) {
 367                         error_report("curl: further errors suppressed");
 368                     }
 369                 }
 370             }
 371
 372             for (i = 0; i < CURL_NUM_ACB; i++) {
 373                 CURLAIOCB *acb = state->acb[i];
 374
 375                 if (acb == NULL) {
 376                     continue;
 377                 }
 378
 379                 if (!error) {
 380                     /* Assert that we have read all data */
 381                     assert(state->buf_off >= acb->end);
 382
 383                     qemu_iovec_from_buf(acb->qiov, 0,
 384                                         state->orig_buf + acb->start,
 385                                         acb->end - acb->start);
 386
 387                     if (acb->end - acb->start < acb->bytes) {
 388                         size_t offset = acb->end - acb->start;
 389                         qemu_iovec_memset(acb->qiov, offset, 0,
 390                                           acb->bytes - offset);
 391                     }
 392                 }
 393
 394                 acb->ret = error ? -EIO : 0;
 395                 state->acb[i] = NULL;
 396                 qemu_mutex_unlock(&s->mutex);
 397                 aio_co_wake(acb->co);
 398                 qemu_mutex_lock(&s->mutex);
 399             }
 400
 401             curl_clean_state(state);
 402             break;
 403         }
 404     }
 405 }
 406
 407 /* Called with s->mutex held.  */
 408 static void curl_multi_do_locked(CURLSocket *socket)
 409 {
 410     BDRVCURLState *s = socket->state->s;
 411     int running;
 412     int r;
 413
 414     if (!s->multi) {
 415         return;
 416     }
 417
 418     do {
 419         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
 420     } while (r == CURLM_CALL_MULTI_PERFORM);
 421 }
 422
 423 static void curl_multi_do(void *arg)
 424 {
 425     CURLSocket *socket = arg;
 426     BDRVCURLState *s = socket->state->s;
 427
 428     qemu_mutex_lock(&s->mutex);
 429     curl_multi_do_locked(socket);
 430     curl_multi_check_completion(s);
 431     qemu_mutex_unlock(&s->mutex);
 432 }
 433
 434 static void curl_multi_timeout_do(void *arg)
 435 {
 436 #ifdef NEED_CURL_TIMER_CALLBACK
 437     BDRVCURLState *s = (BDRVCURLState *)arg;
 438     int running;
 439
 440     if (!s->multi) {
 441         return;
 442     }
 443
 444     qemu_mutex_lock(&s->mutex);
 445     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 446
 447     curl_multi_check_completion(s);
 448     qemu_mutex_unlock(&s->mutex);
 449 #else
 450     abort();
 451 #endif
 452 }
 453
 454 /* Called with s->mutex held.  */
 455 static CURLState *curl_find_state(BDRVCURLState *s)
 456 {
 457     CURLState *state = NULL;
 458     int i;
 459
 460     for (i = 0; i < CURL_NUM_STATES; i++) {
 461         if (!s->states[i].in_use) {
 462             state = &s->states[i];
 463             state->in_use = 1;
 464             break;
 465         }
 466     }
 467     return state;
 468 }
 469
 470 static int curl_init_state(BDRVCURLState *s, CURLState *state)
 471 {
 472     if (!state->curl) {
 473         state->curl = curl_easy_init();
 474         if (!state->curl) {
 475             return -EIO;
 476         }
 477         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 478         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 479                          (long) s->sslverify);
 480         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
 481                          s->sslverify ? 2L : 0L);
 482         if (s->cookie) {
 483             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
 484         }
 485         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
 486         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 487                          (void *)curl_read_cb);
 488         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 489         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 490         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 491         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 492         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 493         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 494         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 495
 496         if (s->username) {
 497             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
 498         }
 499         if (s->password) {
 500             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
 501         }
 502         if (s->proxyusername) {
 503             curl_easy_setopt(state->curl,
 504                              CURLOPT_PROXYUSERNAME, s->proxyusername);
 505         }
 506         if (s->proxypassword) {
 507             curl_easy_setopt(state->curl,
 508                              CURLOPT_PROXYPASSWORD, s->proxypassword);
 509         }
 510
 511         /* Restrict supported protocols to avoid security issues in the more
 512          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 513          * CVE-2013-0249.
 514          *
 515          * Restricting protocols is only supported from 7.19.4 upwards.
 516          */
 517 #if LIBCURL_VERSION_NUM >= 0x071304
 518         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 519         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 520 #endif
 521
 522 #ifdef DEBUG_VERBOSE
 523         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 524 #endif
 525     }
 526
 527     QLIST_INIT(&state->sockets);
 528     state->s = s;
 529
 530     return 0;
 531 }
 532
 533 /* Called with s->mutex held.  */
 534 static void curl_clean_state(CURLState *s)
 535 {
 536     int j;
 537     for (j = 0; j < CURL_NUM_ACB; j++) {
 538         assert(!s->acb[j]);
 539     }
 540
 541     if (s->s->multi)
 542         curl_multi_remove_handle(s->s->multi, s->curl);
 543
 544     while (!QLIST_EMPTY(&s->sockets)) {
 545         CURLSocket *socket = QLIST_FIRST(&s->sockets);
 546
 547         QLIST_REMOVE(socket, next);
 548         g_free(socket);
 549     }
 550
 551     s->in_use = 0;
 552
 553     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
 554 }
 555
 556 static void curl_parse_filename(const char *filename, QDict *options,
 557                                 Error **errp)
 558 {
 559     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
 560 }
 561
 562 static void curl_detach_aio_context(BlockDriverState *bs)
 563 {
 564     BDRVCURLState *s = bs->opaque;
 565     int i;
 566
 567     qemu_mutex_lock(&s->mutex);
 568     for (i = 0; i < CURL_NUM_STATES; i++) {
 569         if (s->states[i].in_use) {
 570             curl_clean_state(&s->states[i]);
 571         }
 572         if (s->states[i].curl) {
 573             curl_easy_cleanup(s->states[i].curl);
 574             s->states[i].curl = NULL;
 575         }
 576         g_free(s->states[i].orig_buf);
 577         s->states[i].orig_buf = NULL;
 578     }
 579     if (s->multi) {
 580         curl_multi_cleanup(s->multi);
 581         s->multi = NULL;
 582     }
 583     qemu_mutex_unlock(&s->mutex);
 584
 585     timer_del(&s->timer);
 586 }
 587
 588 static void curl_attach_aio_context(BlockDriverState *bs,
 589                                     AioContext *new_context)
 590 {
 591     BDRVCURLState *s = bs->opaque;
 592
 593     aio_timer_init(new_context, &s->timer,
 594                    QEMU_CLOCK_REALTIME, SCALE_NS,
 595                    curl_multi_timeout_do, s);
 596
 597     assert(!s->multi);
 598     s->multi = curl_multi_init();
 599     s->aio_context = new_context;
 600     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 601 #ifdef NEED_CURL_TIMER_CALLBACK
 602     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 603     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 604 #endif
 605 }
 606
 607 static QemuOptsList runtime_opts = {
 608     .name = "curl",
 609     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 610     .desc = {
 611         {
 612             .name = CURL_BLOCK_OPT_URL,
 613             .type = QEMU_OPT_STRING,
 614             .help = "URL to open",
 615         },
 616         {
 617             .name = CURL_BLOCK_OPT_READAHEAD,
 618             .type = QEMU_OPT_SIZE,
 619             .help = "Readahead size",
 620         },
 621         {
 622             .name = CURL_BLOCK_OPT_SSLVERIFY,
 623             .type = QEMU_OPT_BOOL,
 624             .help = "Verify SSL certificate"
 625         },
 626         {
 627             .name = CURL_BLOCK_OPT_TIMEOUT,
 628             .type = QEMU_OPT_NUMBER,
 629             .help = "Curl timeout"
 630         },
 631         {
 632             .name = CURL_BLOCK_OPT_COOKIE,
 633             .type = QEMU_OPT_STRING,
 634             .help = "Pass the cookie or list of cookies with each request"
 635         },
 636         {
 637             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
 638             .type = QEMU_OPT_STRING,
 639             .help = "ID of secret used as cookie passed with each request"
 640         },
 641         {
 642             .name = CURL_BLOCK_OPT_USERNAME,
 643             .type = QEMU_OPT_STRING,
 644             .help = "Username for HTTP auth"
 645         },
 646         {
 647             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 648             .type = QEMU_OPT_STRING,
 649             .help = "ID of secret used as password for HTTP auth",
 650         },
 651         {
 652             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 653             .type = QEMU_OPT_STRING,
 654             .help = "Username for HTTP proxy auth"
 655         },
 656         {
 657             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 658             .type = QEMU_OPT_STRING,
 659             .help = "ID of secret used as password for HTTP proxy auth",
 660         },
 661         { /* end of list */ }
 662     },
 663 };
 664
 665
 666 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 667                      Error **errp)
 668 {
 669     BDRVCURLState *s = bs->opaque;
 670     CURLState *state = NULL;
 671     QemuOpts *opts;
 672     const char *file;
 673     const char *cookie;
 674     const char *cookie_secret;
 675     double d;
 676     const char *secretid;
 677     const char *protocol_delimiter;
 678     int ret;
 679
 680     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
 681                                     errp);
 682     if (ret < 0) {
 683         return ret;
 684     }
 685
 686     if (!libcurl_initialized) {
 687         ret = curl_global_init(CURL_GLOBAL_ALL);
 688         if (ret) {
 689             error_setg(errp, "libcurl initialization failed with %d", ret);
 690             return -EIO;
 691         }
 692         libcurl_initialized = true;
 693     }
 694
 695     qemu_mutex_init(&s->mutex);
 696     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 697     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
 698         goto out_noclean;
 699     }
 700
 701     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 702                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
 703     if ((s->readahead_size & 0x1ff) != 0) {
 704         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 705                    s->readahead_size);
 706         goto out_noclean;
 707     }
 708
 709     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 710                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
 711     if (s->timeout > CURL_TIMEOUT_MAX) {
 712         error_setg(errp, "timeout parameter is too large or negative");
 713         goto out_noclean;
 714     }
 715
 716     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
 717                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
 718
 719     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 720     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
 721
 722     if (cookie && cookie_secret) {
 723         error_setg(errp,
 724                    "curl driver cannot handle both cookie and cookie secret");
 725         goto out_noclean;
 726     }
 727
 728     if (cookie_secret) {
 729         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
 730         if (!s->cookie) {
 731             goto out_noclean;
 732         }
 733     } else {
 734         s->cookie = g_strdup(cookie);
 735     }
 736
 737     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 738     if (file == NULL) {
 739         error_setg(errp, "curl block driver requires an 'url' option");
 740         goto out_noclean;
 741     }
 742
 743     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
 744         !strstart(protocol_delimiter, "://", NULL))
 745     {
 746         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
 747                    "start with '%s://')", bs->drv->protocol_name, file,
 748                    bs->drv->protocol_name);
 749         goto out_noclean;
 750     }
 751
 752     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 753     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 754
 755     if (secretid) {
 756         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 757         if (!s->password) {
 758             goto out_noclean;
 759         }
 760     }
 761
 762     s->proxyusername = g_strdup(
 763         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 764     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 765     if (secretid) {
 766         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 767         if (!s->proxypassword) {
 768             goto out_noclean;
 769         }
 770     }
 771
 772     trace_curl_open(file);
 773     qemu_co_queue_init(&s->free_state_waitq);
 774     s->aio_context = bdrv_get_aio_context(bs);
 775     s->url = g_strdup(file);
 776     qemu_mutex_lock(&s->mutex);
 777     state = curl_find_state(s);
 778     qemu_mutex_unlock(&s->mutex);
 779     if (!state) {
 780         goto out_noclean;
 781     }
 782
 783     // Get file size
 784
 785     if (curl_init_state(s, state) < 0) {
 786         goto out;
 787     }
 788
 789     s->accept_range = false;
 790     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 791     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 792                      curl_header_cb);
 793     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 794     if (curl_easy_perform(state->curl))
 795         goto out;
 796     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
 797         goto out;
 798     }
 799     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
 800      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
 801      * known and zero if it is really zero-length file. */
 802 #if LIBCURL_VERSION_NUM >= 0x071304
 803     if (d < 0) {
 804         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 805                 "Server didn't report file size.");
 806         goto out;
 807     }
 808 #else
 809     if (d <= 0) {
 810         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 811                 "Unknown file size or zero-length file.");
 812         goto out;
 813     }
 814 #endif
 815
 816     s->len = d;
 817
 818     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 819         || !strncasecmp(s->url, "https://", strlen("https://")))
 820         && !s->accept_range) {
 821         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 822                 "Server does not support 'range' (byte ranges).");
 823         goto out;
 824     }
 825     trace_curl_open_size(s->len);
 826
 827     qemu_mutex_lock(&s->mutex);
 828     curl_clean_state(state);
 829     qemu_mutex_unlock(&s->mutex);
 830     curl_easy_cleanup(state->curl);
 831     state->curl = NULL;
 832
 833     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 834
 835     qemu_opts_del(opts);
 836     return 0;
 837
 838 out:
 839     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 840     curl_easy_cleanup(state->curl);
 841     state->curl = NULL;
 842 out_noclean:
 843     qemu_mutex_destroy(&s->mutex);
 844     g_free(s->cookie);
 845     g_free(s->url);
 846     g_free(s->username);
 847     g_free(s->proxyusername);
 848     g_free(s->proxypassword);
 849     qemu_opts_del(opts);
 850     return -EINVAL;
 851 }
 852
 853 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
 854 {
 855     CURLState *state;
 856     int running;
 857
 858     BDRVCURLState *s = bs->opaque;
 859
 860     uint64_t start = acb->offset;
 861     uint64_t end;
 862
 863     qemu_mutex_lock(&s->mutex);
 864
 865     // In case we have the requested data already (e.g. read-ahead),
 866     // we can just call the callback and be done.
 867     if (curl_find_buf(s, start, acb->bytes, acb)) {
 868         goto out;
 869     }
 870
 871     // No cache found, so let's start a new request
 872     for (;;) {
 873         state = curl_find_state(s);
 874         if (state) {
 875             break;
 876         }
 877         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
 878     }
 879
 880     if (curl_init_state(s, state) < 0) {
 881         curl_clean_state(state);
 882         acb->ret = -EIO;
 883         goto out;
 884     }
 885
 886     acb->start = 0;
 887     acb->end = MIN(acb->bytes, s->len - start);
 888
 889     state->buf_off = 0;
 890     g_free(state->orig_buf);
 891     state->buf_start = start;
 892     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
 893     end = start + state->buf_len - 1;
 894     state->orig_buf = g_try_malloc(state->buf_len);
 895     if (state->buf_len && state->orig_buf == NULL) {
 896         curl_clean_state(state);
 897         acb->ret = -ENOMEM;
 898         goto out;
 899     }
 900     state->acb[0] = acb;
 901
 902     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
 903     trace_curl_setup_preadv(acb->bytes, start, state->range);
 904     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 905
 906     if (curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
 907         state->acb[0] = NULL;
 908         acb->ret = -EIO;
 909
 910         curl_clean_state(state);
 911         goto out;
 912     }
 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     trace_curl_close();
 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 void curl_refresh_filename(BlockDriverState *bs)
 961 {
 962     BDRVCURLState *s = bs->opaque;
 963
 964     /* "readahead" and "timeout" do not change the guest-visible data,
 965      * so ignore them */
 966     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
 967         s->cookie || s->username || s->password || s->proxyusername ||
 968         s->proxypassword)
 969     {
 970         return;
 971     }
 972
 973     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
 974 }
 975
 976
 977 static const char *const curl_strong_runtime_opts[] = {
 978     CURL_BLOCK_OPT_URL,
 979     CURL_BLOCK_OPT_SSLVERIFY,
 980     CURL_BLOCK_OPT_COOKIE,
 981     CURL_BLOCK_OPT_COOKIE_SECRET,
 982     CURL_BLOCK_OPT_USERNAME,
 983     CURL_BLOCK_OPT_PASSWORD_SECRET,
 984     CURL_BLOCK_OPT_PROXY_USERNAME,
 985     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 986
 987     NULL
 988 };
 989
 990 static BlockDriver bdrv_http = {
 991     .format_name                = "http",
 992     .protocol_name              = "http",
 993
 994     .instance_size              = sizeof(BDRVCURLState),
 995     .bdrv_parse_filename        = curl_parse_filename,
 996     .bdrv_file_open             = curl_open,
 997     .bdrv_close                 = curl_close,
 998     .bdrv_getlength             = curl_getlength,
 999
1000     .bdrv_co_preadv             = curl_co_preadv,
1001
1002     .bdrv_detach_aio_context    = curl_detach_aio_context,
1003     .bdrv_attach_aio_context    = curl_attach_aio_context,
1004
1005     .bdrv_refresh_filename      = curl_refresh_filename,
1006     .strong_runtime_opts        = curl_strong_runtime_opts,
1007 };
1008
1009 static BlockDriver bdrv_https = {
1010     .format_name                = "https",
1011     .protocol_name              = "https",
1012
1013     .instance_size              = sizeof(BDRVCURLState),
1014     .bdrv_parse_filename        = curl_parse_filename,
1015     .bdrv_file_open             = curl_open,
1016     .bdrv_close                 = curl_close,
1017     .bdrv_getlength             = curl_getlength,
1018
1019     .bdrv_co_preadv             = curl_co_preadv,
1020
1021     .bdrv_detach_aio_context    = curl_detach_aio_context,
1022     .bdrv_attach_aio_context    = curl_attach_aio_context,
1023
1024     .bdrv_refresh_filename      = curl_refresh_filename,
1025     .strong_runtime_opts        = curl_strong_runtime_opts,
1026 };
1027
1028 static BlockDriver bdrv_ftp = {
1029     .format_name                = "ftp",
1030     .protocol_name              = "ftp",
1031
1032     .instance_size              = sizeof(BDRVCURLState),
1033     .bdrv_parse_filename        = curl_parse_filename,
1034     .bdrv_file_open             = curl_open,
1035     .bdrv_close                 = curl_close,
1036     .bdrv_getlength             = curl_getlength,
1037
1038     .bdrv_co_preadv             = curl_co_preadv,
1039
1040     .bdrv_detach_aio_context    = curl_detach_aio_context,
1041     .bdrv_attach_aio_context    = curl_attach_aio_context,
1042
1043     .bdrv_refresh_filename      = curl_refresh_filename,
1044     .strong_runtime_opts        = curl_strong_runtime_opts,
1045 };
1046
1047 static BlockDriver bdrv_ftps = {
1048     .format_name                = "ftps",
1049     .protocol_name              = "ftps",
1050
1051     .instance_size              = sizeof(BDRVCURLState),
1052     .bdrv_parse_filename        = curl_parse_filename,
1053     .bdrv_file_open             = curl_open,
1054     .bdrv_close                 = curl_close,
1055     .bdrv_getlength             = curl_getlength,
1056
1057     .bdrv_co_preadv             = curl_co_preadv,
1058
1059     .bdrv_detach_aio_context    = curl_detach_aio_context,
1060     .bdrv_attach_aio_context    = curl_attach_aio_context,
1061
1062     .bdrv_refresh_filename      = curl_refresh_filename,
1063     .strong_runtime_opts        = curl_strong_runtime_opts,
1064 };
1065
1066 static void curl_block_init(void)
1067 {
1068     bdrv_register(&bdrv_http);
1069     bdrv_register(&bdrv_https);
1070     bdrv_register(&bdrv_ftp);
1071     bdrv_register(&bdrv_ftps);
1072 }
1073
1074 block_init(curl_block_init);