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
  84 static bool libcurl_initialized;
  85
  86 typedef struct CURLAIOCB {
  87     Coroutine *co;
  88     QEMUIOVector *qiov;
  89
  90     uint64_t offset;
  91     uint64_t bytes;
  92     int ret;
  93
  94     size_t start;
  95     size_t end;
  96 } CURLAIOCB;
  97
  98 typedef struct CURLSocket {
  99     int fd;
 100     QLIST_ENTRY(CURLSocket) next;
 101 } CURLSocket;
 102
 103 typedef struct CURLState
 104 {
 105     struct BDRVCURLState *s;
 106     CURLAIOCB *acb[CURL_NUM_ACB];
 107     CURL *curl;
 108     QLIST_HEAD(, CURLSocket) sockets;
 109     char *orig_buf;
 110     uint64_t buf_start;
 111     size_t buf_off;
 112     size_t buf_len;
 113     char range[128];
 114     char errmsg[CURL_ERROR_SIZE];
 115     char in_use;
 116 } CURLState;
 117
 118 typedef struct BDRVCURLState {
 119     CURLM *multi;
 120     QEMUTimer timer;
 121     uint64_t len;
 122     CURLState states[CURL_NUM_STATES];
 123     char *url;
 124     size_t readahead_size;
 125     bool sslverify;
 126     uint64_t timeout;
 127     char *cookie;
 128     bool accept_range;
 129     AioContext *aio_context;
 130     QemuMutex mutex;
 131     CoQueue free_state_waitq;
 132     char *username;
 133     char *password;
 134     char *proxyusername;
 135     char *proxypassword;
 136 } BDRVCURLState;
 137
 138 static void curl_clean_state(CURLState *s);
 139 static void curl_multi_do(void *arg);
 140 static void curl_multi_read(void *arg);
 141
 142 #ifdef NEED_CURL_TIMER_CALLBACK
 143 /* Called from curl_multi_do_locked, with s->mutex held.  */
 144 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 145 {
 146     BDRVCURLState *s = opaque;
 147
 148     trace_curl_timer_cb(timeout_ms);
 149     if (timeout_ms == -1) {
 150         timer_del(&s->timer);
 151     } else {
 152         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 153         timer_mod(&s->timer,
 154                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 155     }
 156     return 0;
 157 }
 158 #endif
 159
 160 /* Called from curl_multi_do_locked, with s->mutex held.  */
 161 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 162                         void *userp, void *sp)
 163 {
 164     BDRVCURLState *s;
 165     CURLState *state = NULL;
 166     CURLSocket *socket;
 167
 168     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 169     s = state->s;
 170
 171     QLIST_FOREACH(socket, &state->sockets, next) {
 172         if (socket->fd == fd) {
 173             if (action == CURL_POLL_REMOVE) {
 174                 QLIST_REMOVE(socket, next);
 175                 g_free(socket);
 176             }
 177             break;
 178         }
 179     }
 180     if (!socket) {
 181         socket = g_new0(CURLSocket, 1);
 182         socket->fd = fd;
 183         QLIST_INSERT_HEAD(&state->sockets, socket, next);
 184     }
 185     socket = NULL;
 186
 187     trace_curl_sock_cb(action, (int)fd);
 188     switch (action) {
 189         case CURL_POLL_IN:
 190             aio_set_fd_handler(s->aio_context, fd, false,
 191                                curl_multi_read, NULL, NULL, state);
 192             break;
 193         case CURL_POLL_OUT:
 194             aio_set_fd_handler(s->aio_context, fd, false,
 195                                NULL, curl_multi_do, NULL, state);
 196             break;
 197         case CURL_POLL_INOUT:
 198             aio_set_fd_handler(s->aio_context, fd, false,
 199                                curl_multi_read, curl_multi_do, NULL, state);
 200             break;
 201         case CURL_POLL_REMOVE:
 202             aio_set_fd_handler(s->aio_context, fd, false,
 203                                NULL, NULL, NULL, NULL);
 204             break;
 205     }
 206
 207     return 0;
 208 }
 209
 210 /* Called from curl_multi_do_locked, with s->mutex held.  */
 211 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 212 {
 213     BDRVCURLState *s = opaque;
 214     size_t realsize = size * nmemb;
 215     const char *accept_line = "Accept-Ranges: bytes";
 216
 217     if (realsize >= strlen(accept_line)
 218         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
 219         s->accept_range = true;
 220     }
 221
 222     return realsize;
 223 }
 224
 225 /* Called from curl_multi_do_locked, with s->mutex held.  */
 226 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 227 {
 228     CURLState *s = ((CURLState*)opaque);
 229     size_t realsize = size * nmemb;
 230     int i;
 231
 232     trace_curl_read_cb(realsize);
 233
 234     if (!s || !s->orig_buf) {
 235         goto read_end;
 236     }
 237
 238     if (s->buf_off >= s->buf_len) {
 239         /* buffer full, read nothing */
 240         goto read_end;
 241     }
 242     realsize = MIN(realsize, s->buf_len - s->buf_off);
 243     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 244     s->buf_off += realsize;
 245
 246     for(i=0; i<CURL_NUM_ACB; i++) {
 247         CURLAIOCB *acb = s->acb[i];
 248
 249         if (!acb)
 250             continue;
 251
 252         if ((s->buf_off >= acb->end)) {
 253             size_t request_length = acb->bytes;
 254
 255             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
 256                                 acb->end - acb->start);
 257
 258             if (acb->end - acb->start < request_length) {
 259                 size_t offset = acb->end - acb->start;
 260                 qemu_iovec_memset(acb->qiov, offset, 0,
 261                                   request_length - offset);
 262             }
 263
 264             acb->ret = 0;
 265             s->acb[i] = NULL;
 266             qemu_mutex_unlock(&s->s->mutex);
 267             aio_co_wake(acb->co);
 268             qemu_mutex_lock(&s->s->mutex);
 269         }
 270     }
 271
 272 read_end:
 273     /* curl will error out if we do not return this value */
 274     return size * nmemb;
 275 }
 276
 277 /* Called with s->mutex held.  */
 278 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
 279                           CURLAIOCB *acb)
 280 {
 281     int i;
 282     uint64_t end = start + len;
 283     uint64_t clamped_end = MIN(end, s->len);
 284     uint64_t clamped_len = clamped_end - start;
 285
 286     for (i=0; i<CURL_NUM_STATES; i++) {
 287         CURLState *state = &s->states[i];
 288         uint64_t buf_end = (state->buf_start + state->buf_off);
 289         uint64_t buf_fend = (state->buf_start + state->buf_len);
 290
 291         if (!state->orig_buf)
 292             continue;
 293         if (!state->buf_off)
 294             continue;
 295
 296         // Does the existing buffer cover our section?
 297         if ((start >= state->buf_start) &&
 298             (start <= buf_end) &&
 299             (clamped_end >= state->buf_start) &&
 300             (clamped_end <= buf_end))
 301         {
 302             char *buf = state->orig_buf + (start - state->buf_start);
 303
 304             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
 305             if (clamped_len < len) {
 306                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
 307             }
 308             acb->ret = 0;
 309             return true;
 310         }
 311
 312         // Wait for unfinished chunks
 313         if (state->in_use &&
 314             (start >= state->buf_start) &&
 315             (start <= buf_fend) &&
 316             (clamped_end >= state->buf_start) &&
 317             (clamped_end <= buf_fend))
 318         {
 319             int j;
 320
 321             acb->start = start - state->buf_start;
 322             acb->end = acb->start + clamped_len;
 323
 324             for (j=0; j<CURL_NUM_ACB; j++) {
 325                 if (!state->acb[j]) {
 326                     state->acb[j] = acb;
 327                     return true;
 328                 }
 329             }
 330         }
 331     }
 332
 333     return false;
 334 }
 335
 336 /* Called with s->mutex held.  */
 337 static void curl_multi_check_completion(BDRVCURLState *s)
 338 {
 339     int msgs_in_queue;
 340
 341     /* Try to find done transfers, so we can free the easy
 342      * handle again. */
 343     for (;;) {
 344         CURLMsg *msg;
 345         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 346
 347         /* Quit when there are no more completions */
 348         if (!msg)
 349             break;
 350
 351         if (msg->msg == CURLMSG_DONE) {
 352             CURLState *state = NULL;
 353             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 354                               (char **)&state);
 355
 356             /* ACBs for successful messages get completed in curl_read_cb */
 357             if (msg->data.result != CURLE_OK) {
 358                 int i;
 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                 for (i = 0; i < CURL_NUM_ACB; i++) {
 372                     CURLAIOCB *acb = state->acb[i];
 373
 374                     if (acb == NULL) {
 375                         continue;
 376                     }
 377
 378                     acb->ret = -EIO;
 379                     state->acb[i] = NULL;
 380                     qemu_mutex_unlock(&s->mutex);
 381                     aio_co_wake(acb->co);
 382                     qemu_mutex_lock(&s->mutex);
 383                 }
 384             }
 385
 386             curl_clean_state(state);
 387             break;
 388         }
 389     }
 390 }
 391
 392 /* Called with s->mutex held.  */
 393 static void curl_multi_do_locked(CURLState *s)
 394 {
 395     CURLSocket *socket, *next_socket;
 396     int running;
 397     int r;
 398
 399     if (!s->s->multi) {
 400         return;
 401     }
 402
 403     /* Need to use _SAFE because curl_multi_socket_action() may trigger
 404      * curl_sock_cb() which might modify this list */
 405     QLIST_FOREACH_SAFE(socket, &s->sockets, next, next_socket) {
 406         do {
 407             r = curl_multi_socket_action(s->s->multi, socket->fd, 0, &running);
 408         } while (r == CURLM_CALL_MULTI_PERFORM);
 409     }
 410 }
 411
 412 static void curl_multi_do(void *arg)
 413 {
 414     CURLState *s = (CURLState *)arg;
 415
 416     qemu_mutex_lock(&s->s->mutex);
 417     curl_multi_do_locked(s);
 418     qemu_mutex_unlock(&s->s->mutex);
 419 }
 420
 421 static void curl_multi_read(void *arg)
 422 {
 423     CURLState *s = (CURLState *)arg;
 424
 425     qemu_mutex_lock(&s->s->mutex);
 426     curl_multi_do_locked(s);
 427     curl_multi_check_completion(s->s);
 428     qemu_mutex_unlock(&s->s->mutex);
 429 }
 430
 431 static void curl_multi_timeout_do(void *arg)
 432 {
 433 #ifdef NEED_CURL_TIMER_CALLBACK
 434     BDRVCURLState *s = (BDRVCURLState *)arg;
 435     int running;
 436
 437     if (!s->multi) {
 438         return;
 439     }
 440
 441     qemu_mutex_lock(&s->mutex);
 442     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 443
 444     curl_multi_check_completion(s);
 445     qemu_mutex_unlock(&s->mutex);
 446 #else
 447     abort();
 448 #endif
 449 }
 450
 451 /* Called with s->mutex held.  */
 452 static CURLState *curl_find_state(BDRVCURLState *s)
 453 {
 454     CURLState *state = NULL;
 455     int i;
 456
 457     for (i = 0; i < CURL_NUM_STATES; i++) {
 458         if (!s->states[i].in_use) {
 459             state = &s->states[i];
 460             state->in_use = 1;
 461             break;
 462         }
 463     }
 464     return state;
 465 }
 466
 467 static int curl_init_state(BDRVCURLState *s, CURLState *state)
 468 {
 469     if (!state->curl) {
 470         state->curl = curl_easy_init();
 471         if (!state->curl) {
 472             return -EIO;
 473         }
 474         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 475         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 476                          (long) s->sslverify);
 477         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
 478                          s->sslverify ? 2L : 0L);
 479         if (s->cookie) {
 480             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
 481         }
 482         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
 483         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 484                          (void *)curl_read_cb);
 485         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 486         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 487         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 488         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 489         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 490         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 491         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 492
 493         if (s->username) {
 494             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
 495         }
 496         if (s->password) {
 497             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
 498         }
 499         if (s->proxyusername) {
 500             curl_easy_setopt(state->curl,
 501                              CURLOPT_PROXYUSERNAME, s->proxyusername);
 502         }
 503         if (s->proxypassword) {
 504             curl_easy_setopt(state->curl,
 505                              CURLOPT_PROXYPASSWORD, s->proxypassword);
 506         }
 507
 508         /* Restrict supported protocols to avoid security issues in the more
 509          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 510          * CVE-2013-0249.
 511          *
 512          * Restricting protocols is only supported from 7.19.4 upwards.
 513          */
 514 #if LIBCURL_VERSION_NUM >= 0x071304
 515         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 516         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 517 #endif
 518
 519 #ifdef DEBUG_VERBOSE
 520         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 521 #endif
 522     }
 523
 524     QLIST_INIT(&state->sockets);
 525     state->s = s;
 526
 527     return 0;
 528 }
 529
 530 /* Called with s->mutex held.  */
 531 static void curl_clean_state(CURLState *s)
 532 {
 533     int j;
 534     for (j = 0; j < CURL_NUM_ACB; j++) {
 535         assert(!s->acb[j]);
 536     }
 537
 538     if (s->s->multi)
 539         curl_multi_remove_handle(s->s->multi, s->curl);
 540
 541     while (!QLIST_EMPTY(&s->sockets)) {
 542         CURLSocket *socket = QLIST_FIRST(&s->sockets);
 543
 544         QLIST_REMOVE(socket, next);
 545         g_free(socket);
 546     }
 547
 548     s->in_use = 0;
 549
 550     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
 551 }
 552
 553 static void curl_parse_filename(const char *filename, QDict *options,
 554                                 Error **errp)
 555 {
 556     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
 557 }
 558
 559 static void curl_detach_aio_context(BlockDriverState *bs)
 560 {
 561     BDRVCURLState *s = bs->opaque;
 562     int i;
 563
 564     qemu_mutex_lock(&s->mutex);
 565     for (i = 0; i < CURL_NUM_STATES; i++) {
 566         if (s->states[i].in_use) {
 567             curl_clean_state(&s->states[i]);
 568         }
 569         if (s->states[i].curl) {
 570             curl_easy_cleanup(s->states[i].curl);
 571             s->states[i].curl = NULL;
 572         }
 573         g_free(s->states[i].orig_buf);
 574         s->states[i].orig_buf = NULL;
 575     }
 576     if (s->multi) {
 577         curl_multi_cleanup(s->multi);
 578         s->multi = NULL;
 579     }
 580     qemu_mutex_unlock(&s->mutex);
 581
 582     timer_del(&s->timer);
 583 }
 584
 585 static void curl_attach_aio_context(BlockDriverState *bs,
 586                                     AioContext *new_context)
 587 {
 588     BDRVCURLState *s = bs->opaque;
 589
 590     aio_timer_init(new_context, &s->timer,
 591                    QEMU_CLOCK_REALTIME, SCALE_NS,
 592                    curl_multi_timeout_do, s);
 593
 594     assert(!s->multi);
 595     s->multi = curl_multi_init();
 596     s->aio_context = new_context;
 597     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 598 #ifdef NEED_CURL_TIMER_CALLBACK
 599     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 600     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 601 #endif
 602 }
 603
 604 static QemuOptsList runtime_opts = {
 605     .name = "curl",
 606     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 607     .desc = {
 608         {
 609             .name = CURL_BLOCK_OPT_URL,
 610             .type = QEMU_OPT_STRING,
 611             .help = "URL to open",
 612         },
 613         {
 614             .name = CURL_BLOCK_OPT_READAHEAD,
 615             .type = QEMU_OPT_SIZE,
 616             .help = "Readahead size",
 617         },
 618         {
 619             .name = CURL_BLOCK_OPT_SSLVERIFY,
 620             .type = QEMU_OPT_BOOL,
 621             .help = "Verify SSL certificate"
 622         },
 623         {
 624             .name = CURL_BLOCK_OPT_TIMEOUT,
 625             .type = QEMU_OPT_NUMBER,
 626             .help = "Curl timeout"
 627         },
 628         {
 629             .name = CURL_BLOCK_OPT_COOKIE,
 630             .type = QEMU_OPT_STRING,
 631             .help = "Pass the cookie or list of cookies with each request"
 632         },
 633         {
 634             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
 635             .type = QEMU_OPT_STRING,
 636             .help = "ID of secret used as cookie passed with each request"
 637         },
 638         {
 639             .name = CURL_BLOCK_OPT_USERNAME,
 640             .type = QEMU_OPT_STRING,
 641             .help = "Username for HTTP auth"
 642         },
 643         {
 644             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 645             .type = QEMU_OPT_STRING,
 646             .help = "ID of secret used as password for HTTP auth",
 647         },
 648         {
 649             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 650             .type = QEMU_OPT_STRING,
 651             .help = "Username for HTTP proxy auth"
 652         },
 653         {
 654             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 655             .type = QEMU_OPT_STRING,
 656             .help = "ID of secret used as password for HTTP proxy auth",
 657         },
 658         { /* end of list */ }
 659     },
 660 };
 661
 662
 663 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 664                      Error **errp)
 665 {
 666     BDRVCURLState *s = bs->opaque;
 667     CURLState *state = NULL;
 668     QemuOpts *opts;
 669     Error *local_err = NULL;
 670     const char *file;
 671     const char *cookie;
 672     const char *cookie_secret;
 673     double d;
 674     const char *secretid;
 675     const char *protocol_delimiter;
 676     int ret;
 677
 678     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
 679                                     errp);
 680     if (ret < 0) {
 681         return ret;
 682     }
 683
 684     if (!libcurl_initialized) {
 685         ret = curl_global_init(CURL_GLOBAL_ALL);
 686         if (ret) {
 687             error_setg(errp, "libcurl initialization failed with %d", ret);
 688             return -EIO;
 689         }
 690         libcurl_initialized = true;
 691     }
 692
 693     qemu_mutex_init(&s->mutex);
 694     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 695     qemu_opts_absorb_qdict(opts, options, &local_err);
 696     if (local_err) {
 697         error_propagate(errp, local_err);
 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     curl_multi_add_handle(s->multi, state->curl);
 907
 908     /* Tell curl it needs to kick things off */
 909     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 910
 911 out:
 912     qemu_mutex_unlock(&s->mutex);
 913 }
 914
 915 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
 916         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
 917 {
 918     CURLAIOCB acb = {
 919         .co = qemu_coroutine_self(),
 920         .ret = -EINPROGRESS,
 921         .qiov = qiov,
 922         .offset = offset,
 923         .bytes = bytes
 924     };
 925
 926     curl_setup_preadv(bs, &acb);
 927     while (acb.ret == -EINPROGRESS) {
 928         qemu_coroutine_yield();
 929     }
 930     return acb.ret;
 931 }
 932
 933 static void curl_close(BlockDriverState *bs)
 934 {
 935     BDRVCURLState *s = bs->opaque;
 936
 937     trace_curl_close();
 938     curl_detach_aio_context(bs);
 939     qemu_mutex_destroy(&s->mutex);
 940
 941     g_free(s->cookie);
 942     g_free(s->url);
 943     g_free(s->username);
 944     g_free(s->proxyusername);
 945     g_free(s->proxypassword);
 946 }
 947
 948 static int64_t curl_getlength(BlockDriverState *bs)
 949 {
 950     BDRVCURLState *s = bs->opaque;
 951     return s->len;
 952 }
 953
 954 static void curl_refresh_filename(BlockDriverState *bs)
 955 {
 956     BDRVCURLState *s = bs->opaque;
 957
 958     /* "readahead" and "timeout" do not change the guest-visible data,
 959      * so ignore them */
 960     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
 961         s->cookie || s->username || s->password || s->proxyusername ||
 962         s->proxypassword)
 963     {
 964         return;
 965     }
 966
 967     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
 968 }
 969
 970
 971 static const char *const curl_strong_runtime_opts[] = {
 972     CURL_BLOCK_OPT_URL,
 973     CURL_BLOCK_OPT_SSLVERIFY,
 974     CURL_BLOCK_OPT_COOKIE,
 975     CURL_BLOCK_OPT_COOKIE_SECRET,
 976     CURL_BLOCK_OPT_USERNAME,
 977     CURL_BLOCK_OPT_PASSWORD_SECRET,
 978     CURL_BLOCK_OPT_PROXY_USERNAME,
 979     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 980
 981     NULL
 982 };
 983
 984 static BlockDriver bdrv_http = {
 985     .format_name                = "http",
 986     .protocol_name              = "http",
 987
 988     .instance_size              = sizeof(BDRVCURLState),
 989     .bdrv_parse_filename        = curl_parse_filename,
 990     .bdrv_file_open             = curl_open,
 991     .bdrv_close                 = curl_close,
 992     .bdrv_getlength             = curl_getlength,
 993
 994     .bdrv_co_preadv             = curl_co_preadv,
 995
 996     .bdrv_detach_aio_context    = curl_detach_aio_context,
 997     .bdrv_attach_aio_context    = curl_attach_aio_context,
 998
 999     .bdrv_refresh_filename      = curl_refresh_filename,
1000     .strong_runtime_opts        = curl_strong_runtime_opts,
1001 };
1002
1003 static BlockDriver bdrv_https = {
1004     .format_name                = "https",
1005     .protocol_name              = "https",
1006
1007     .instance_size              = sizeof(BDRVCURLState),
1008     .bdrv_parse_filename        = curl_parse_filename,
1009     .bdrv_file_open             = curl_open,
1010     .bdrv_close                 = curl_close,
1011     .bdrv_getlength             = curl_getlength,
1012
1013     .bdrv_co_preadv             = curl_co_preadv,
1014
1015     .bdrv_detach_aio_context    = curl_detach_aio_context,
1016     .bdrv_attach_aio_context    = curl_attach_aio_context,
1017
1018     .bdrv_refresh_filename      = curl_refresh_filename,
1019     .strong_runtime_opts        = curl_strong_runtime_opts,
1020 };
1021
1022 static BlockDriver bdrv_ftp = {
1023     .format_name                = "ftp",
1024     .protocol_name              = "ftp",
1025
1026     .instance_size              = sizeof(BDRVCURLState),
1027     .bdrv_parse_filename        = curl_parse_filename,
1028     .bdrv_file_open             = curl_open,
1029     .bdrv_close                 = curl_close,
1030     .bdrv_getlength             = curl_getlength,
1031
1032     .bdrv_co_preadv             = curl_co_preadv,
1033
1034     .bdrv_detach_aio_context    = curl_detach_aio_context,
1035     .bdrv_attach_aio_context    = curl_attach_aio_context,
1036
1037     .bdrv_refresh_filename      = curl_refresh_filename,
1038     .strong_runtime_opts        = curl_strong_runtime_opts,
1039 };
1040
1041 static BlockDriver bdrv_ftps = {
1042     .format_name                = "ftps",
1043     .protocol_name              = "ftps",
1044
1045     .instance_size              = sizeof(BDRVCURLState),
1046     .bdrv_parse_filename        = curl_parse_filename,
1047     .bdrv_file_open             = curl_open,
1048     .bdrv_close                 = curl_close,
1049     .bdrv_getlength             = curl_getlength,
1050
1051     .bdrv_co_preadv             = curl_co_preadv,
1052
1053     .bdrv_detach_aio_context    = curl_detach_aio_context,
1054     .bdrv_attach_aio_context    = curl_attach_aio_context,
1055
1056     .bdrv_refresh_filename      = curl_refresh_filename,
1057     .strong_runtime_opts        = curl_strong_runtime_opts,
1058 };
1059
1060 static void curl_block_init(void)
1061 {
1062     bdrv_register(&bdrv_http);
1063     bdrv_register(&bdrv_https);
1064     bdrv_register(&bdrv_ftp);
1065     bdrv_register(&bdrv_ftps);
1066 }
1067
1068 block_init(curl_block_init);