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 #include "trace.h"
  36
  37 // #define DEBUG_VERBOSE
  38
  39 #if LIBCURL_VERSION_NUM >= 0x071000
  40 /* The multi interface timer callback was introduced in 7.16.0 */
  41 #define NEED_CURL_TIMER_CALLBACK
  42 #define HAVE_SOCKET_ACTION
  43 #endif
  44
  45 #ifndef HAVE_SOCKET_ACTION
  46 /* If curl_multi_socket_action isn't available, define it statically here in
  47  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
  48  * less efficient but still safe. */
  49 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
  50                                             curl_socket_t sockfd,
  51                                             int ev_bitmask,
  52                                             int *running_handles)
  53 {
  54     return curl_multi_socket(multi_handle, sockfd, running_handles);
  55 }
  56 #define curl_multi_socket_action __curl_multi_socket_action
  57 #endif
  58
  59 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  60                    CURLPROTO_FTP | CURLPROTO_FTPS)
  61
  62 #define CURL_NUM_STATES 8
  63 #define CURL_NUM_ACB    8
  64 #define CURL_TIMEOUT_MAX 10000
  65
  66 #define CURL_BLOCK_OPT_URL       "url"
  67 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  68 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  69 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
  70 #define CURL_BLOCK_OPT_COOKIE    "cookie"
  71 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
  72 #define CURL_BLOCK_OPT_USERNAME "username"
  73 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
  74 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
  75 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
  76
  77 #define CURL_BLOCK_OPT_READAHEAD_DEFAULT (256 * 1024)
  78 #define CURL_BLOCK_OPT_SSLVERIFY_DEFAULT true
  79 #define CURL_BLOCK_OPT_TIMEOUT_DEFAULT 5
  80
  81 struct BDRVCURLState;
  82
  83 static bool libcurl_initialized;
  84
  85 typedef struct CURLAIOCB {
  86     Coroutine *co;
  87     QEMUIOVector *qiov;
  88
  89     uint64_t offset;
  90     uint64_t bytes;
  91     int ret;
  92
  93     size_t start;
  94     size_t end;
  95 } CURLAIOCB;
  96
  97 typedef struct CURLSocket {
  98     int fd;
  99     QLIST_ENTRY(CURLSocket) next;
 100 } CURLSocket;
 101
 102 typedef struct CURLState
 103 {
 104     struct BDRVCURLState *s;
 105     CURLAIOCB *acb[CURL_NUM_ACB];
 106     CURL *curl;
 107     QLIST_HEAD(, CURLSocket) sockets;
 108     char *orig_buf;
 109     uint64_t buf_start;
 110     size_t buf_off;
 111     size_t buf_len;
 112     char range[128];
 113     char errmsg[CURL_ERROR_SIZE];
 114     char in_use;
 115 } CURLState;
 116
 117 typedef struct BDRVCURLState {
 118     CURLM *multi;
 119     QEMUTimer timer;
 120     uint64_t len;
 121     CURLState states[CURL_NUM_STATES];
 122     char *url;
 123     size_t readahead_size;
 124     bool sslverify;
 125     uint64_t timeout;
 126     char *cookie;
 127     bool accept_range;
 128     AioContext *aio_context;
 129     QemuMutex mutex;
 130     CoQueue free_state_waitq;
 131     char *username;
 132     char *password;
 133     char *proxyusername;
 134     char *proxypassword;
 135 } BDRVCURLState;
 136
 137 static void curl_clean_state(CURLState *s);
 138 static void curl_multi_do(void *arg);
 139 static void curl_multi_read(void *arg);
 140
 141 #ifdef NEED_CURL_TIMER_CALLBACK
 142 /* Called from curl_multi_do_locked, with s->mutex held.  */
 143 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 144 {
 145     BDRVCURLState *s = opaque;
 146
 147     trace_curl_timer_cb(timeout_ms);
 148     if (timeout_ms == -1) {
 149         timer_del(&s->timer);
 150     } else {
 151         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 152         timer_mod(&s->timer,
 153                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 154     }
 155     return 0;
 156 }
 157 #endif
 158
 159 /* Called from curl_multi_do_locked, with s->mutex held.  */
 160 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 161                         void *userp, void *sp)
 162 {
 163     BDRVCURLState *s;
 164     CURLState *state = NULL;
 165     CURLSocket *socket;
 166
 167     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 168     s = state->s;
 169
 170     QLIST_FOREACH(socket, &state->sockets, next) {
 171         if (socket->fd == fd) {
 172             if (action == CURL_POLL_REMOVE) {
 173                 QLIST_REMOVE(socket, next);
 174                 g_free(socket);
 175             }
 176             break;
 177         }
 178     }
 179     if (!socket) {
 180         socket = g_new0(CURLSocket, 1);
 181         socket->fd = fd;
 182         QLIST_INSERT_HEAD(&state->sockets, socket, next);
 183     }
 184     socket = NULL;
 185
 186     trace_curl_sock_cb(action, (int)fd);
 187     switch (action) {
 188         case CURL_POLL_IN:
 189             aio_set_fd_handler(s->aio_context, fd, false,
 190                                curl_multi_read, NULL, NULL, state);
 191             break;
 192         case CURL_POLL_OUT:
 193             aio_set_fd_handler(s->aio_context, fd, false,
 194                                NULL, curl_multi_do, NULL, state);
 195             break;
 196         case CURL_POLL_INOUT:
 197             aio_set_fd_handler(s->aio_context, fd, false,
 198                                curl_multi_read, curl_multi_do, NULL, state);
 199             break;
 200         case CURL_POLL_REMOVE:
 201             aio_set_fd_handler(s->aio_context, fd, false,
 202                                NULL, NULL, NULL, NULL);
 203             break;
 204     }
 205
 206     return 0;
 207 }
 208
 209 /* Called from curl_multi_do_locked, with s->mutex held.  */
 210 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 211 {
 212     BDRVCURLState *s = opaque;
 213     size_t realsize = size * nmemb;
 214     const char *accept_line = "Accept-Ranges: bytes";
 215
 216     if (realsize >= strlen(accept_line)
 217         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
 218         s->accept_range = true;
 219     }
 220
 221     return realsize;
 222 }
 223
 224 /* Called from curl_multi_do_locked, with s->mutex held.  */
 225 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 226 {
 227     CURLState *s = ((CURLState*)opaque);
 228     size_t realsize = size * nmemb;
 229     int i;
 230
 231     trace_curl_read_cb(realsize);
 232
 233     if (!s || !s->orig_buf) {
 234         goto read_end;
 235     }
 236
 237     if (s->buf_off >= s->buf_len) {
 238         /* buffer full, read nothing */
 239         goto read_end;
 240     }
 241     realsize = MIN(realsize, s->buf_len - s->buf_off);
 242     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 243     s->buf_off += realsize;
 244
 245     for(i=0; i<CURL_NUM_ACB; i++) {
 246         CURLAIOCB *acb = s->acb[i];
 247
 248         if (!acb)
 249             continue;
 250
 251         if ((s->buf_off >= acb->end)) {
 252             size_t request_length = acb->bytes;
 253
 254             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
 255                                 acb->end - acb->start);
 256
 257             if (acb->end - acb->start < request_length) {
 258                 size_t offset = acb->end - acb->start;
 259                 qemu_iovec_memset(acb->qiov, offset, 0,
 260                                   request_length - offset);
 261             }
 262
 263             acb->ret = 0;
 264             s->acb[i] = NULL;
 265             qemu_mutex_unlock(&s->s->mutex);
 266             aio_co_wake(acb->co);
 267             qemu_mutex_lock(&s->s->mutex);
 268         }
 269     }
 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             CURLState *state = NULL;
 352             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 353                               (char **)&state);
 354
 355             /* ACBs for successful messages get completed in curl_read_cb */
 356             if (msg->data.result != CURLE_OK) {
 357                 int i;
 358                 static int errcount = 100;
 359
 360                 /* Don't lose the original error message from curl, since
 361                  * it contains extra data.
 362                  */
 363                 if (errcount > 0) {
 364                     error_report("curl: %s", state->errmsg);
 365                     if (--errcount == 0) {
 366                         error_report("curl: further errors suppressed");
 367                     }
 368                 }
 369
 370                 for (i = 0; i < CURL_NUM_ACB; i++) {
 371                     CURLAIOCB *acb = state->acb[i];
 372
 373                     if (acb == NULL) {
 374                         continue;
 375                     }
 376
 377                     acb->ret = -EIO;
 378                     state->acb[i] = NULL;
 379                     qemu_mutex_unlock(&s->mutex);
 380                     aio_co_wake(acb->co);
 381                     qemu_mutex_lock(&s->mutex);
 382                 }
 383             }
 384
 385             curl_clean_state(state);
 386             break;
 387         }
 388     }
 389 }
 390
 391 /* Called with s->mutex held.  */
 392 static void curl_multi_do_locked(CURLState *s)
 393 {
 394     CURLSocket *socket, *next_socket;
 395     int running;
 396     int r;
 397
 398     if (!s->s->multi) {
 399         return;
 400     }
 401
 402     /* Need to use _SAFE because curl_multi_socket_action() may trigger
 403      * curl_sock_cb() which might modify this list */
 404     QLIST_FOREACH_SAFE(socket, &s->sockets, next, next_socket) {
 405         do {
 406             r = curl_multi_socket_action(s->s->multi, socket->fd, 0, &running);
 407         } while (r == CURLM_CALL_MULTI_PERFORM);
 408     }
 409 }
 410
 411 static void curl_multi_do(void *arg)
 412 {
 413     CURLState *s = (CURLState *)arg;
 414
 415     qemu_mutex_lock(&s->s->mutex);
 416     curl_multi_do_locked(s);
 417     qemu_mutex_unlock(&s->s->mutex);
 418 }
 419
 420 static void curl_multi_read(void *arg)
 421 {
 422     CURLState *s = (CURLState *)arg;
 423
 424     qemu_mutex_lock(&s->s->mutex);
 425     curl_multi_do_locked(s);
 426     curl_multi_check_completion(s->s);
 427     qemu_mutex_unlock(&s->s->mutex);
 428 }
 429
 430 static void curl_multi_timeout_do(void *arg)
 431 {
 432 #ifdef NEED_CURL_TIMER_CALLBACK
 433     BDRVCURLState *s = (BDRVCURLState *)arg;
 434     int running;
 435
 436     if (!s->multi) {
 437         return;
 438     }
 439
 440     qemu_mutex_lock(&s->mutex);
 441     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 442
 443     curl_multi_check_completion(s);
 444     qemu_mutex_unlock(&s->mutex);
 445 #else
 446     abort();
 447 #endif
 448 }
 449
 450 /* Called with s->mutex held.  */
 451 static CURLState *curl_find_state(BDRVCURLState *s)
 452 {
 453     CURLState *state = NULL;
 454     int i;
 455
 456     for (i = 0; i < CURL_NUM_STATES; i++) {
 457         if (!s->states[i].in_use) {
 458             state = &s->states[i];
 459             state->in_use = 1;
 460             break;
 461         }
 462     }
 463     return state;
 464 }
 465
 466 static int curl_init_state(BDRVCURLState *s, CURLState *state)
 467 {
 468     if (!state->curl) {
 469         state->curl = curl_easy_init();
 470         if (!state->curl) {
 471             return -EIO;
 472         }
 473         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 474         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 475                          (long) s->sslverify);
 476         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
 477                          s->sslverify ? 2L : 0L);
 478         if (s->cookie) {
 479             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
 480         }
 481         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
 482         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 483                          (void *)curl_read_cb);
 484         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 485         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 486         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 487         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 488         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 489         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 490         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 491
 492         if (s->username) {
 493             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
 494         }
 495         if (s->password) {
 496             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
 497         }
 498         if (s->proxyusername) {
 499             curl_easy_setopt(state->curl,
 500                              CURLOPT_PROXYUSERNAME, s->proxyusername);
 501         }
 502         if (s->proxypassword) {
 503             curl_easy_setopt(state->curl,
 504                              CURLOPT_PROXYPASSWORD, s->proxypassword);
 505         }
 506
 507         /* Restrict supported protocols to avoid security issues in the more
 508          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 509          * CVE-2013-0249.
 510          *
 511          * Restricting protocols is only supported from 7.19.4 upwards.
 512          */
 513 #if LIBCURL_VERSION_NUM >= 0x071304
 514         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 515         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 516 #endif
 517
 518 #ifdef DEBUG_VERBOSE
 519         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 520 #endif
 521     }
 522
 523     QLIST_INIT(&state->sockets);
 524     state->s = s;
 525
 526     return 0;
 527 }
 528
 529 /* Called with s->mutex held.  */
 530 static void curl_clean_state(CURLState *s)
 531 {
 532     int j;
 533     for (j = 0; j < CURL_NUM_ACB; j++) {
 534         assert(!s->acb[j]);
 535     }
 536
 537     if (s->s->multi)
 538         curl_multi_remove_handle(s->s->multi, s->curl);
 539
 540     while (!QLIST_EMPTY(&s->sockets)) {
 541         CURLSocket *socket = QLIST_FIRST(&s->sockets);
 542
 543         QLIST_REMOVE(socket, next);
 544         g_free(socket);
 545     }
 546
 547     s->in_use = 0;
 548
 549     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
 550 }
 551
 552 static void curl_parse_filename(const char *filename, QDict *options,
 553                                 Error **errp)
 554 {
 555     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
 556 }
 557
 558 static void curl_detach_aio_context(BlockDriverState *bs)
 559 {
 560     BDRVCURLState *s = bs->opaque;
 561     int i;
 562
 563     qemu_mutex_lock(&s->mutex);
 564     for (i = 0; i < CURL_NUM_STATES; i++) {
 565         if (s->states[i].in_use) {
 566             curl_clean_state(&s->states[i]);
 567         }
 568         if (s->states[i].curl) {
 569             curl_easy_cleanup(s->states[i].curl);
 570             s->states[i].curl = NULL;
 571         }
 572         g_free(s->states[i].orig_buf);
 573         s->states[i].orig_buf = NULL;
 574     }
 575     if (s->multi) {
 576         curl_multi_cleanup(s->multi);
 577         s->multi = NULL;
 578     }
 579     qemu_mutex_unlock(&s->mutex);
 580
 581     timer_del(&s->timer);
 582 }
 583
 584 static void curl_attach_aio_context(BlockDriverState *bs,
 585                                     AioContext *new_context)
 586 {
 587     BDRVCURLState *s = bs->opaque;
 588
 589     aio_timer_init(new_context, &s->timer,
 590                    QEMU_CLOCK_REALTIME, SCALE_NS,
 591                    curl_multi_timeout_do, s);
 592
 593     assert(!s->multi);
 594     s->multi = curl_multi_init();
 595     s->aio_context = new_context;
 596     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 597 #ifdef NEED_CURL_TIMER_CALLBACK
 598     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 599     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 600 #endif
 601 }
 602
 603 static QemuOptsList runtime_opts = {
 604     .name = "curl",
 605     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 606     .desc = {
 607         {
 608             .name = CURL_BLOCK_OPT_URL,
 609             .type = QEMU_OPT_STRING,
 610             .help = "URL to open",
 611         },
 612         {
 613             .name = CURL_BLOCK_OPT_READAHEAD,
 614             .type = QEMU_OPT_SIZE,
 615             .help = "Readahead size",
 616         },
 617         {
 618             .name = CURL_BLOCK_OPT_SSLVERIFY,
 619             .type = QEMU_OPT_BOOL,
 620             .help = "Verify SSL certificate"
 621         },
 622         {
 623             .name = CURL_BLOCK_OPT_TIMEOUT,
 624             .type = QEMU_OPT_NUMBER,
 625             .help = "Curl timeout"
 626         },
 627         {
 628             .name = CURL_BLOCK_OPT_COOKIE,
 629             .type = QEMU_OPT_STRING,
 630             .help = "Pass the cookie or list of cookies with each request"
 631         },
 632         {
 633             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
 634             .type = QEMU_OPT_STRING,
 635             .help = "ID of secret used as cookie passed with each request"
 636         },
 637         {
 638             .name = CURL_BLOCK_OPT_USERNAME,
 639             .type = QEMU_OPT_STRING,
 640             .help = "Username for HTTP auth"
 641         },
 642         {
 643             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 644             .type = QEMU_OPT_STRING,
 645             .help = "ID of secret used as password for HTTP auth",
 646         },
 647         {
 648             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 649             .type = QEMU_OPT_STRING,
 650             .help = "Username for HTTP proxy auth"
 651         },
 652         {
 653             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 654             .type = QEMU_OPT_STRING,
 655             .help = "ID of secret used as password for HTTP proxy auth",
 656         },
 657         { /* end of list */ }
 658     },
 659 };
 660
 661
 662 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 663                      Error **errp)
 664 {
 665     BDRVCURLState *s = bs->opaque;
 666     CURLState *state = NULL;
 667     QemuOpts *opts;
 668     Error *local_err = NULL;
 669     const char *file;
 670     const char *cookie;
 671     const char *cookie_secret;
 672     double d;
 673     const char *secretid;
 674     const char *protocol_delimiter;
 675     int ret;
 676
 677     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
 678                                     errp);
 679     if (ret < 0) {
 680         return ret;
 681     }
 682
 683     if (!libcurl_initialized) {
 684         ret = curl_global_init(CURL_GLOBAL_ALL);
 685         if (ret) {
 686             error_setg(errp, "libcurl initialization failed with %d", ret);
 687             return -EIO;
 688         }
 689         libcurl_initialized = true;
 690     }
 691
 692     qemu_mutex_init(&s->mutex);
 693     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 694     qemu_opts_absorb_qdict(opts, options, &local_err);
 695     if (local_err) {
 696         error_propagate(errp, local_err);
 697         goto out_noclean;
 698     }
 699
 700     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 701                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
 702     if ((s->readahead_size & 0x1ff) != 0) {
 703         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 704                    s->readahead_size);
 705         goto out_noclean;
 706     }
 707
 708     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 709                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
 710     if (s->timeout > CURL_TIMEOUT_MAX) {
 711         error_setg(errp, "timeout parameter is too large or negative");
 712         goto out_noclean;
 713     }
 714
 715     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
 716                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
 717
 718     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 719     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
 720
 721     if (cookie && cookie_secret) {
 722         error_setg(errp,
 723                    "curl driver cannot handle both cookie and cookie secret");
 724         goto out_noclean;
 725     }
 726
 727     if (cookie_secret) {
 728         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
 729         if (!s->cookie) {
 730             goto out_noclean;
 731         }
 732     } else {
 733         s->cookie = g_strdup(cookie);
 734     }
 735
 736     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 737     if (file == NULL) {
 738         error_setg(errp, "curl block driver requires an 'url' option");
 739         goto out_noclean;
 740     }
 741
 742     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
 743         !strstart(protocol_delimiter, "://", NULL))
 744     {
 745         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
 746                    "start with '%s://')", bs->drv->protocol_name, file,
 747                    bs->drv->protocol_name);
 748         goto out_noclean;
 749     }
 750
 751     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 752     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 753
 754     if (secretid) {
 755         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 756         if (!s->password) {
 757             goto out_noclean;
 758         }
 759     }
 760
 761     s->proxyusername = g_strdup(
 762         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 763     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 764     if (secretid) {
 765         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 766         if (!s->proxypassword) {
 767             goto out_noclean;
 768         }
 769     }
 770
 771     trace_curl_open(file);
 772     qemu_co_queue_init(&s->free_state_waitq);
 773     s->aio_context = bdrv_get_aio_context(bs);
 774     s->url = g_strdup(file);
 775     qemu_mutex_lock(&s->mutex);
 776     state = curl_find_state(s);
 777     qemu_mutex_unlock(&s->mutex);
 778     if (!state) {
 779         goto out_noclean;
 780     }
 781
 782     // Get file size
 783
 784     if (curl_init_state(s, state) < 0) {
 785         goto out;
 786     }
 787
 788     s->accept_range = false;
 789     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 790     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 791                      curl_header_cb);
 792     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 793     if (curl_easy_perform(state->curl))
 794         goto out;
 795     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
 796         goto out;
 797     }
 798     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
 799      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
 800      * known and zero if it is really zero-length file. */
 801 #if LIBCURL_VERSION_NUM >= 0x071304
 802     if (d < 0) {
 803         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 804                 "Server didn't report file size.");
 805         goto out;
 806     }
 807 #else
 808     if (d <= 0) {
 809         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 810                 "Unknown file size or zero-length file.");
 811         goto out;
 812     }
 813 #endif
 814
 815     s->len = d;
 816
 817     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 818         || !strncasecmp(s->url, "https://", strlen("https://")))
 819         && !s->accept_range) {
 820         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 821                 "Server does not support 'range' (byte ranges).");
 822         goto out;
 823     }
 824     trace_curl_open_size(s->len);
 825
 826     qemu_mutex_lock(&s->mutex);
 827     curl_clean_state(state);
 828     qemu_mutex_unlock(&s->mutex);
 829     curl_easy_cleanup(state->curl);
 830     state->curl = NULL;
 831
 832     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 833
 834     qemu_opts_del(opts);
 835     return 0;
 836
 837 out:
 838     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 839     curl_easy_cleanup(state->curl);
 840     state->curl = NULL;
 841 out_noclean:
 842     qemu_mutex_destroy(&s->mutex);
 843     g_free(s->cookie);
 844     g_free(s->url);
 845     g_free(s->username);
 846     g_free(s->proxyusername);
 847     g_free(s->proxypassword);
 848     qemu_opts_del(opts);
 849     return -EINVAL;
 850 }
 851
 852 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
 853 {
 854     CURLState *state;
 855     int running;
 856
 857     BDRVCURLState *s = bs->opaque;
 858
 859     uint64_t start = acb->offset;
 860     uint64_t end;
 861
 862     qemu_mutex_lock(&s->mutex);
 863
 864     // In case we have the requested data already (e.g. read-ahead),
 865     // we can just call the callback and be done.
 866     if (curl_find_buf(s, start, acb->bytes, acb)) {
 867         goto out;
 868     }
 869
 870     // No cache found, so let's start a new request
 871     for (;;) {
 872         state = curl_find_state(s);
 873         if (state) {
 874             break;
 875         }
 876         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
 877     }
 878
 879     if (curl_init_state(s, state) < 0) {
 880         curl_clean_state(state);
 881         acb->ret = -EIO;
 882         goto out;
 883     }
 884
 885     acb->start = 0;
 886     acb->end = MIN(acb->bytes, s->len - start);
 887
 888     state->buf_off = 0;
 889     g_free(state->orig_buf);
 890     state->buf_start = start;
 891     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
 892     end = start + state->buf_len - 1;
 893     state->orig_buf = g_try_malloc(state->buf_len);
 894     if (state->buf_len && state->orig_buf == NULL) {
 895         curl_clean_state(state);
 896         acb->ret = -ENOMEM;
 897         goto out;
 898     }
 899     state->acb[0] = acb;
 900
 901     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
 902     trace_curl_setup_preadv(acb->bytes, start, state->range);
 903     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 904
 905     curl_multi_add_handle(s->multi, state->curl);
 906
 907     /* Tell curl it needs to kick things off */
 908     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 909
 910 out:
 911     qemu_mutex_unlock(&s->mutex);
 912 }
 913
 914 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
 915         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
 916 {
 917     CURLAIOCB acb = {
 918         .co = qemu_coroutine_self(),
 919         .ret = -EINPROGRESS,
 920         .qiov = qiov,
 921         .offset = offset,
 922         .bytes = bytes
 923     };
 924
 925     curl_setup_preadv(bs, &acb);
 926     while (acb.ret == -EINPROGRESS) {
 927         qemu_coroutine_yield();
 928     }
 929     return acb.ret;
 930 }
 931
 932 static void curl_close(BlockDriverState *bs)
 933 {
 934     BDRVCURLState *s = bs->opaque;
 935
 936     trace_curl_close();
 937     curl_detach_aio_context(bs);
 938     qemu_mutex_destroy(&s->mutex);
 939
 940     g_free(s->cookie);
 941     g_free(s->url);
 942     g_free(s->username);
 943     g_free(s->proxyusername);
 944     g_free(s->proxypassword);
 945 }
 946
 947 static int64_t curl_getlength(BlockDriverState *bs)
 948 {
 949     BDRVCURLState *s = bs->opaque;
 950     return s->len;
 951 }
 952
 953 static void curl_refresh_filename(BlockDriverState *bs)
 954 {
 955     BDRVCURLState *s = bs->opaque;
 956
 957     /* "readahead" and "timeout" do not change the guest-visible data,
 958      * so ignore them */
 959     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
 960         s->cookie || s->username || s->password || s->proxyusername ||
 961         s->proxypassword)
 962     {
 963         return;
 964     }
 965
 966     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
 967 }
 968
 969
 970 static const char *const curl_strong_runtime_opts[] = {
 971     CURL_BLOCK_OPT_URL,
 972     CURL_BLOCK_OPT_SSLVERIFY,
 973     CURL_BLOCK_OPT_COOKIE,
 974     CURL_BLOCK_OPT_COOKIE_SECRET,
 975     CURL_BLOCK_OPT_USERNAME,
 976     CURL_BLOCK_OPT_PASSWORD_SECRET,
 977     CURL_BLOCK_OPT_PROXY_USERNAME,
 978     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 979
 980     NULL
 981 };
 982
 983 static BlockDriver bdrv_http = {
 984     .format_name                = "http",
 985     .protocol_name              = "http",
 986
 987     .instance_size              = sizeof(BDRVCURLState),
 988     .bdrv_parse_filename        = curl_parse_filename,
 989     .bdrv_file_open             = curl_open,
 990     .bdrv_close                 = curl_close,
 991     .bdrv_getlength             = curl_getlength,
 992
 993     .bdrv_co_preadv             = curl_co_preadv,
 994
 995     .bdrv_detach_aio_context    = curl_detach_aio_context,
 996     .bdrv_attach_aio_context    = curl_attach_aio_context,
 997
 998     .bdrv_refresh_filename      = curl_refresh_filename,
 999     .strong_runtime_opts        = curl_strong_runtime_opts,
1000 };
1001
1002 static BlockDriver bdrv_https = {
1003     .format_name                = "https",
1004     .protocol_name              = "https",
1005
1006     .instance_size              = sizeof(BDRVCURLState),
1007     .bdrv_parse_filename        = curl_parse_filename,
1008     .bdrv_file_open             = curl_open,
1009     .bdrv_close                 = curl_close,
1010     .bdrv_getlength             = curl_getlength,
1011
1012     .bdrv_co_preadv             = curl_co_preadv,
1013
1014     .bdrv_detach_aio_context    = curl_detach_aio_context,
1015     .bdrv_attach_aio_context    = curl_attach_aio_context,
1016
1017     .bdrv_refresh_filename      = curl_refresh_filename,
1018     .strong_runtime_opts        = curl_strong_runtime_opts,
1019 };
1020
1021 static BlockDriver bdrv_ftp = {
1022     .format_name                = "ftp",
1023     .protocol_name              = "ftp",
1024
1025     .instance_size              = sizeof(BDRVCURLState),
1026     .bdrv_parse_filename        = curl_parse_filename,
1027     .bdrv_file_open             = curl_open,
1028     .bdrv_close                 = curl_close,
1029     .bdrv_getlength             = curl_getlength,
1030
1031     .bdrv_co_preadv             = curl_co_preadv,
1032
1033     .bdrv_detach_aio_context    = curl_detach_aio_context,
1034     .bdrv_attach_aio_context    = curl_attach_aio_context,
1035
1036     .bdrv_refresh_filename      = curl_refresh_filename,
1037     .strong_runtime_opts        = curl_strong_runtime_opts,
1038 };
1039
1040 static BlockDriver bdrv_ftps = {
1041     .format_name                = "ftps",
1042     .protocol_name              = "ftps",
1043
1044     .instance_size              = sizeof(BDRVCURLState),
1045     .bdrv_parse_filename        = curl_parse_filename,
1046     .bdrv_file_open             = curl_open,
1047     .bdrv_close                 = curl_close,
1048     .bdrv_getlength             = curl_getlength,
1049
1050     .bdrv_co_preadv             = curl_co_preadv,
1051
1052     .bdrv_detach_aio_context    = curl_detach_aio_context,
1053     .bdrv_attach_aio_context    = curl_attach_aio_context,
1054
1055     .bdrv_refresh_filename      = curl_refresh_filename,
1056     .strong_runtime_opts        = curl_strong_runtime_opts,
1057 };
1058
1059 static void curl_block_init(void)
1060 {
1061     bdrv_register(&bdrv_http);
1062     bdrv_register(&bdrv_https);
1063     bdrv_register(&bdrv_ftp);
1064     bdrv_register(&bdrv_ftps);
1065 }
1066
1067 block_init(curl_block_init);