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 *accept_line = "Accept-Ranges: bytes";
 218
 219     if (realsize >= strlen(accept_line)
 220         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
 221         s->accept_range = true;
 222     }
 223
 224     return realsize;
 225 }
 226
 227 /* Called from curl_multi_do_locked, with s->mutex held.  */
 228 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 229 {
 230     CURLState *s = ((CURLState*)opaque);
 231     size_t realsize = size * nmemb;
 232     int i;
 233
 234     trace_curl_read_cb(realsize);
 235
 236     if (!s || !s->orig_buf) {
 237         goto read_end;
 238     }
 239
 240     if (s->buf_off >= s->buf_len) {
 241         /* buffer full, read nothing */
 242         goto read_end;
 243     }
 244     realsize = MIN(realsize, s->buf_len - s->buf_off);
 245     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 246     s->buf_off += realsize;
 247
 248     for(i=0; i<CURL_NUM_ACB; i++) {
 249         CURLAIOCB *acb = s->acb[i];
 250
 251         if (!acb)
 252             continue;
 253
 254         if ((s->buf_off >= acb->end)) {
 255             size_t request_length = acb->bytes;
 256
 257             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
 258                                 acb->end - acb->start);
 259
 260             if (acb->end - acb->start < request_length) {
 261                 size_t offset = acb->end - acb->start;
 262                 qemu_iovec_memset(acb->qiov, offset, 0,
 263                                   request_length - offset);
 264             }
 265
 266             acb->ret = 0;
 267             s->acb[i] = NULL;
 268             qemu_mutex_unlock(&s->s->mutex);
 269             aio_co_wake(acb->co);
 270             qemu_mutex_lock(&s->s->mutex);
 271         }
 272     }
 273
 274 read_end:
 275     /* curl will error out if we do not return this value */
 276     return size * nmemb;
 277 }
 278
 279 /* Called with s->mutex held.  */
 280 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
 281                           CURLAIOCB *acb)
 282 {
 283     int i;
 284     uint64_t end = start + len;
 285     uint64_t clamped_end = MIN(end, s->len);
 286     uint64_t clamped_len = clamped_end - start;
 287
 288     for (i=0; i<CURL_NUM_STATES; i++) {
 289         CURLState *state = &s->states[i];
 290         uint64_t buf_end = (state->buf_start + state->buf_off);
 291         uint64_t buf_fend = (state->buf_start + state->buf_len);
 292
 293         if (!state->orig_buf)
 294             continue;
 295         if (!state->buf_off)
 296             continue;
 297
 298         // Does the existing buffer cover our section?
 299         if ((start >= state->buf_start) &&
 300             (start <= buf_end) &&
 301             (clamped_end >= state->buf_start) &&
 302             (clamped_end <= buf_end))
 303         {
 304             char *buf = state->orig_buf + (start - state->buf_start);
 305
 306             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
 307             if (clamped_len < len) {
 308                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
 309             }
 310             acb->ret = 0;
 311             return true;
 312         }
 313
 314         // Wait for unfinished chunks
 315         if (state->in_use &&
 316             (start >= state->buf_start) &&
 317             (start <= buf_fend) &&
 318             (clamped_end >= state->buf_start) &&
 319             (clamped_end <= buf_fend))
 320         {
 321             int j;
 322
 323             acb->start = start - state->buf_start;
 324             acb->end = acb->start + clamped_len;
 325
 326             for (j=0; j<CURL_NUM_ACB; j++) {
 327                 if (!state->acb[j]) {
 328                     state->acb[j] = acb;
 329                     return true;
 330                 }
 331             }
 332         }
 333     }
 334
 335     return false;
 336 }
 337
 338 /* Called with s->mutex held.  */
 339 static void curl_multi_check_completion(BDRVCURLState *s)
 340 {
 341     int msgs_in_queue;
 342
 343     /* Try to find done transfers, so we can free the easy
 344      * handle again. */
 345     for (;;) {
 346         CURLMsg *msg;
 347         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 348
 349         /* Quit when there are no more completions */
 350         if (!msg)
 351             break;
 352
 353         if (msg->msg == CURLMSG_DONE) {
 354             CURLState *state = NULL;
 355             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 356                               (char **)&state);
 357
 358             /* ACBs for successful messages get completed in curl_read_cb */
 359             if (msg->data.result != CURLE_OK) {
 360                 int i;
 361                 static int errcount = 100;
 362
 363                 /* Don't lose the original error message from curl, since
 364                  * it contains extra data.
 365                  */
 366                 if (errcount > 0) {
 367                     error_report("curl: %s", state->errmsg);
 368                     if (--errcount == 0) {
 369                         error_report("curl: further errors suppressed");
 370                     }
 371                 }
 372
 373                 for (i = 0; i < CURL_NUM_ACB; i++) {
 374                     CURLAIOCB *acb = state->acb[i];
 375
 376                     if (acb == NULL) {
 377                         continue;
 378                     }
 379
 380                     acb->ret = -EIO;
 381                     state->acb[i] = NULL;
 382                     qemu_mutex_unlock(&s->mutex);
 383                     aio_co_wake(acb->co);
 384                     qemu_mutex_lock(&s->mutex);
 385                 }
 386             }
 387
 388             curl_clean_state(state);
 389             break;
 390         }
 391     }
 392 }
 393
 394 /* Called with s->mutex held.  */
 395 static void curl_multi_do_locked(CURLSocket *socket)
 396 {
 397     BDRVCURLState *s = socket->state->s;
 398     int running;
 399     int r;
 400
 401     if (!s->multi) {
 402         return;
 403     }
 404
 405     do {
 406         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
 407     } while (r == CURLM_CALL_MULTI_PERFORM);
 408 }
 409
 410 static void curl_multi_do(void *arg)
 411 {
 412     CURLSocket *socket = arg;
 413     BDRVCURLState *s = socket->state->s;
 414
 415     qemu_mutex_lock(&s->mutex);
 416     curl_multi_do_locked(socket);
 417     curl_multi_check_completion(s);
 418     qemu_mutex_unlock(&s->mutex);
 419 }
 420
 421 static void curl_multi_timeout_do(void *arg)
 422 {
 423 #ifdef NEED_CURL_TIMER_CALLBACK
 424     BDRVCURLState *s = (BDRVCURLState *)arg;
 425     int running;
 426
 427     if (!s->multi) {
 428         return;
 429     }
 430
 431     qemu_mutex_lock(&s->mutex);
 432     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 433
 434     curl_multi_check_completion(s);
 435     qemu_mutex_unlock(&s->mutex);
 436 #else
 437     abort();
 438 #endif
 439 }
 440
 441 /* Called with s->mutex held.  */
 442 static CURLState *curl_find_state(BDRVCURLState *s)
 443 {
 444     CURLState *state = NULL;
 445     int i;
 446
 447     for (i = 0; i < CURL_NUM_STATES; i++) {
 448         if (!s->states[i].in_use) {
 449             state = &s->states[i];
 450             state->in_use = 1;
 451             break;
 452         }
 453     }
 454     return state;
 455 }
 456
 457 static int curl_init_state(BDRVCURLState *s, CURLState *state)
 458 {
 459     if (!state->curl) {
 460         state->curl = curl_easy_init();
 461         if (!state->curl) {
 462             return -EIO;
 463         }
 464         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 465         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 466                          (long) s->sslverify);
 467         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
 468                          s->sslverify ? 2L : 0L);
 469         if (s->cookie) {
 470             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
 471         }
 472         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
 473         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 474                          (void *)curl_read_cb);
 475         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 476         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 477         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 478         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 479         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 480         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 481         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 482
 483         if (s->username) {
 484             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
 485         }
 486         if (s->password) {
 487             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
 488         }
 489         if (s->proxyusername) {
 490             curl_easy_setopt(state->curl,
 491                              CURLOPT_PROXYUSERNAME, s->proxyusername);
 492         }
 493         if (s->proxypassword) {
 494             curl_easy_setopt(state->curl,
 495                              CURLOPT_PROXYPASSWORD, s->proxypassword);
 496         }
 497
 498         /* Restrict supported protocols to avoid security issues in the more
 499          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 500          * CVE-2013-0249.
 501          *
 502          * Restricting protocols is only supported from 7.19.4 upwards.
 503          */
 504 #if LIBCURL_VERSION_NUM >= 0x071304
 505         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 506         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 507 #endif
 508
 509 #ifdef DEBUG_VERBOSE
 510         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 511 #endif
 512     }
 513
 514     QLIST_INIT(&state->sockets);
 515     state->s = s;
 516
 517     return 0;
 518 }
 519
 520 /* Called with s->mutex held.  */
 521 static void curl_clean_state(CURLState *s)
 522 {
 523     int j;
 524     for (j = 0; j < CURL_NUM_ACB; j++) {
 525         assert(!s->acb[j]);
 526     }
 527
 528     if (s->s->multi)
 529         curl_multi_remove_handle(s->s->multi, s->curl);
 530
 531     while (!QLIST_EMPTY(&s->sockets)) {
 532         CURLSocket *socket = QLIST_FIRST(&s->sockets);
 533
 534         QLIST_REMOVE(socket, next);
 535         g_free(socket);
 536     }
 537
 538     s->in_use = 0;
 539
 540     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
 541 }
 542
 543 static void curl_parse_filename(const char *filename, QDict *options,
 544                                 Error **errp)
 545 {
 546     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
 547 }
 548
 549 static void curl_detach_aio_context(BlockDriverState *bs)
 550 {
 551     BDRVCURLState *s = bs->opaque;
 552     int i;
 553
 554     qemu_mutex_lock(&s->mutex);
 555     for (i = 0; i < CURL_NUM_STATES; i++) {
 556         if (s->states[i].in_use) {
 557             curl_clean_state(&s->states[i]);
 558         }
 559         if (s->states[i].curl) {
 560             curl_easy_cleanup(s->states[i].curl);
 561             s->states[i].curl = NULL;
 562         }
 563         g_free(s->states[i].orig_buf);
 564         s->states[i].orig_buf = NULL;
 565     }
 566     if (s->multi) {
 567         curl_multi_cleanup(s->multi);
 568         s->multi = NULL;
 569     }
 570     qemu_mutex_unlock(&s->mutex);
 571
 572     timer_del(&s->timer);
 573 }
 574
 575 static void curl_attach_aio_context(BlockDriverState *bs,
 576                                     AioContext *new_context)
 577 {
 578     BDRVCURLState *s = bs->opaque;
 579
 580     aio_timer_init(new_context, &s->timer,
 581                    QEMU_CLOCK_REALTIME, SCALE_NS,
 582                    curl_multi_timeout_do, s);
 583
 584     assert(!s->multi);
 585     s->multi = curl_multi_init();
 586     s->aio_context = new_context;
 587     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 588 #ifdef NEED_CURL_TIMER_CALLBACK
 589     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 590     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 591 #endif
 592 }
 593
 594 static QemuOptsList runtime_opts = {
 595     .name = "curl",
 596     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 597     .desc = {
 598         {
 599             .name = CURL_BLOCK_OPT_URL,
 600             .type = QEMU_OPT_STRING,
 601             .help = "URL to open",
 602         },
 603         {
 604             .name = CURL_BLOCK_OPT_READAHEAD,
 605             .type = QEMU_OPT_SIZE,
 606             .help = "Readahead size",
 607         },
 608         {
 609             .name = CURL_BLOCK_OPT_SSLVERIFY,
 610             .type = QEMU_OPT_BOOL,
 611             .help = "Verify SSL certificate"
 612         },
 613         {
 614             .name = CURL_BLOCK_OPT_TIMEOUT,
 615             .type = QEMU_OPT_NUMBER,
 616             .help = "Curl timeout"
 617         },
 618         {
 619             .name = CURL_BLOCK_OPT_COOKIE,
 620             .type = QEMU_OPT_STRING,
 621             .help = "Pass the cookie or list of cookies with each request"
 622         },
 623         {
 624             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
 625             .type = QEMU_OPT_STRING,
 626             .help = "ID of secret used as cookie passed with each request"
 627         },
 628         {
 629             .name = CURL_BLOCK_OPT_USERNAME,
 630             .type = QEMU_OPT_STRING,
 631             .help = "Username for HTTP auth"
 632         },
 633         {
 634             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 635             .type = QEMU_OPT_STRING,
 636             .help = "ID of secret used as password for HTTP auth",
 637         },
 638         {
 639             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 640             .type = QEMU_OPT_STRING,
 641             .help = "Username for HTTP proxy auth"
 642         },
 643         {
 644             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 645             .type = QEMU_OPT_STRING,
 646             .help = "ID of secret used as password for HTTP proxy auth",
 647         },
 648         { /* end of list */ }
 649     },
 650 };
 651
 652
 653 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 654                      Error **errp)
 655 {
 656     BDRVCURLState *s = bs->opaque;
 657     CURLState *state = NULL;
 658     QemuOpts *opts;
 659     Error *local_err = NULL;
 660     const char *file;
 661     const char *cookie;
 662     const char *cookie_secret;
 663     double d;
 664     const char *secretid;
 665     const char *protocol_delimiter;
 666     int ret;
 667
 668     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
 669                                     errp);
 670     if (ret < 0) {
 671         return ret;
 672     }
 673
 674     if (!libcurl_initialized) {
 675         ret = curl_global_init(CURL_GLOBAL_ALL);
 676         if (ret) {
 677             error_setg(errp, "libcurl initialization failed with %d", ret);
 678             return -EIO;
 679         }
 680         libcurl_initialized = true;
 681     }
 682
 683     qemu_mutex_init(&s->mutex);
 684     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 685     qemu_opts_absorb_qdict(opts, options, &local_err);
 686     if (local_err) {
 687         error_propagate(errp, local_err);
 688         goto out_noclean;
 689     }
 690
 691     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 692                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
 693     if ((s->readahead_size & 0x1ff) != 0) {
 694         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 695                    s->readahead_size);
 696         goto out_noclean;
 697     }
 698
 699     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 700                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
 701     if (s->timeout > CURL_TIMEOUT_MAX) {
 702         error_setg(errp, "timeout parameter is too large or negative");
 703         goto out_noclean;
 704     }
 705
 706     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
 707                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
 708
 709     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 710     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
 711
 712     if (cookie && cookie_secret) {
 713         error_setg(errp,
 714                    "curl driver cannot handle both cookie and cookie secret");
 715         goto out_noclean;
 716     }
 717
 718     if (cookie_secret) {
 719         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
 720         if (!s->cookie) {
 721             goto out_noclean;
 722         }
 723     } else {
 724         s->cookie = g_strdup(cookie);
 725     }
 726
 727     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 728     if (file == NULL) {
 729         error_setg(errp, "curl block driver requires an 'url' option");
 730         goto out_noclean;
 731     }
 732
 733     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
 734         !strstart(protocol_delimiter, "://", NULL))
 735     {
 736         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
 737                    "start with '%s://')", bs->drv->protocol_name, file,
 738                    bs->drv->protocol_name);
 739         goto out_noclean;
 740     }
 741
 742     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 743     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 744
 745     if (secretid) {
 746         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 747         if (!s->password) {
 748             goto out_noclean;
 749         }
 750     }
 751
 752     s->proxyusername = g_strdup(
 753         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 754     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 755     if (secretid) {
 756         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 757         if (!s->proxypassword) {
 758             goto out_noclean;
 759         }
 760     }
 761
 762     trace_curl_open(file);
 763     qemu_co_queue_init(&s->free_state_waitq);
 764     s->aio_context = bdrv_get_aio_context(bs);
 765     s->url = g_strdup(file);
 766     qemu_mutex_lock(&s->mutex);
 767     state = curl_find_state(s);
 768     qemu_mutex_unlock(&s->mutex);
 769     if (!state) {
 770         goto out_noclean;
 771     }
 772
 773     // Get file size
 774
 775     if (curl_init_state(s, state) < 0) {
 776         goto out;
 777     }
 778
 779     s->accept_range = false;
 780     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 781     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 782                      curl_header_cb);
 783     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 784     if (curl_easy_perform(state->curl))
 785         goto out;
 786     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
 787         goto out;
 788     }
 789     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
 790      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
 791      * known and zero if it is really zero-length file. */
 792 #if LIBCURL_VERSION_NUM >= 0x071304
 793     if (d < 0) {
 794         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 795                 "Server didn't report file size.");
 796         goto out;
 797     }
 798 #else
 799     if (d <= 0) {
 800         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 801                 "Unknown file size or zero-length file.");
 802         goto out;
 803     }
 804 #endif
 805
 806     s->len = d;
 807
 808     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 809         || !strncasecmp(s->url, "https://", strlen("https://")))
 810         && !s->accept_range) {
 811         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 812                 "Server does not support 'range' (byte ranges).");
 813         goto out;
 814     }
 815     trace_curl_open_size(s->len);
 816
 817     qemu_mutex_lock(&s->mutex);
 818     curl_clean_state(state);
 819     qemu_mutex_unlock(&s->mutex);
 820     curl_easy_cleanup(state->curl);
 821     state->curl = NULL;
 822
 823     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 824
 825     qemu_opts_del(opts);
 826     return 0;
 827
 828 out:
 829     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 830     curl_easy_cleanup(state->curl);
 831     state->curl = NULL;
 832 out_noclean:
 833     qemu_mutex_destroy(&s->mutex);
 834     g_free(s->cookie);
 835     g_free(s->url);
 836     g_free(s->username);
 837     g_free(s->proxyusername);
 838     g_free(s->proxypassword);
 839     qemu_opts_del(opts);
 840     return -EINVAL;
 841 }
 842
 843 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
 844 {
 845     CURLState *state;
 846     int running;
 847
 848     BDRVCURLState *s = bs->opaque;
 849
 850     uint64_t start = acb->offset;
 851     uint64_t end;
 852
 853     qemu_mutex_lock(&s->mutex);
 854
 855     // In case we have the requested data already (e.g. read-ahead),
 856     // we can just call the callback and be done.
 857     if (curl_find_buf(s, start, acb->bytes, acb)) {
 858         goto out;
 859     }
 860
 861     // No cache found, so let's start a new request
 862     for (;;) {
 863         state = curl_find_state(s);
 864         if (state) {
 865             break;
 866         }
 867         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
 868     }
 869
 870     if (curl_init_state(s, state) < 0) {
 871         curl_clean_state(state);
 872         acb->ret = -EIO;
 873         goto out;
 874     }
 875
 876     acb->start = 0;
 877     acb->end = MIN(acb->bytes, s->len - start);
 878
 879     state->buf_off = 0;
 880     g_free(state->orig_buf);
 881     state->buf_start = start;
 882     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
 883     end = start + state->buf_len - 1;
 884     state->orig_buf = g_try_malloc(state->buf_len);
 885     if (state->buf_len && state->orig_buf == NULL) {
 886         curl_clean_state(state);
 887         acb->ret = -ENOMEM;
 888         goto out;
 889     }
 890     state->acb[0] = acb;
 891
 892     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
 893     trace_curl_setup_preadv(acb->bytes, start, state->range);
 894     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 895
 896     curl_multi_add_handle(s->multi, state->curl);
 897
 898     /* Tell curl it needs to kick things off */
 899     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 900
 901 out:
 902     qemu_mutex_unlock(&s->mutex);
 903 }
 904
 905 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
 906         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
 907 {
 908     CURLAIOCB acb = {
 909         .co = qemu_coroutine_self(),
 910         .ret = -EINPROGRESS,
 911         .qiov = qiov,
 912         .offset = offset,
 913         .bytes = bytes
 914     };
 915
 916     curl_setup_preadv(bs, &acb);
 917     while (acb.ret == -EINPROGRESS) {
 918         qemu_coroutine_yield();
 919     }
 920     return acb.ret;
 921 }
 922
 923 static void curl_close(BlockDriverState *bs)
 924 {
 925     BDRVCURLState *s = bs->opaque;
 926
 927     trace_curl_close();
 928     curl_detach_aio_context(bs);
 929     qemu_mutex_destroy(&s->mutex);
 930
 931     g_free(s->cookie);
 932     g_free(s->url);
 933     g_free(s->username);
 934     g_free(s->proxyusername);
 935     g_free(s->proxypassword);
 936 }
 937
 938 static int64_t curl_getlength(BlockDriverState *bs)
 939 {
 940     BDRVCURLState *s = bs->opaque;
 941     return s->len;
 942 }
 943
 944 static void curl_refresh_filename(BlockDriverState *bs)
 945 {
 946     BDRVCURLState *s = bs->opaque;
 947
 948     /* "readahead" and "timeout" do not change the guest-visible data,
 949      * so ignore them */
 950     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
 951         s->cookie || s->username || s->password || s->proxyusername ||
 952         s->proxypassword)
 953     {
 954         return;
 955     }
 956
 957     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
 958 }
 959
 960
 961 static const char *const curl_strong_runtime_opts[] = {
 962     CURL_BLOCK_OPT_URL,
 963     CURL_BLOCK_OPT_SSLVERIFY,
 964     CURL_BLOCK_OPT_COOKIE,
 965     CURL_BLOCK_OPT_COOKIE_SECRET,
 966     CURL_BLOCK_OPT_USERNAME,
 967     CURL_BLOCK_OPT_PASSWORD_SECRET,
 968     CURL_BLOCK_OPT_PROXY_USERNAME,
 969     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 970
 971     NULL
 972 };
 973
 974 static BlockDriver bdrv_http = {
 975     .format_name                = "http",
 976     .protocol_name              = "http",
 977
 978     .instance_size              = sizeof(BDRVCURLState),
 979     .bdrv_parse_filename        = curl_parse_filename,
 980     .bdrv_file_open             = curl_open,
 981     .bdrv_close                 = curl_close,
 982     .bdrv_getlength             = curl_getlength,
 983
 984     .bdrv_co_preadv             = curl_co_preadv,
 985
 986     .bdrv_detach_aio_context    = curl_detach_aio_context,
 987     .bdrv_attach_aio_context    = curl_attach_aio_context,
 988
 989     .bdrv_refresh_filename      = curl_refresh_filename,
 990     .strong_runtime_opts        = curl_strong_runtime_opts,
 991 };
 992
 993 static BlockDriver bdrv_https = {
 994     .format_name                = "https",
 995     .protocol_name              = "https",
 996
 997     .instance_size              = sizeof(BDRVCURLState),
 998     .bdrv_parse_filename        = curl_parse_filename,
 999     .bdrv_file_open             = curl_open,
1000     .bdrv_close                 = curl_close,
1001     .bdrv_getlength             = curl_getlength,
1002
1003     .bdrv_co_preadv             = curl_co_preadv,
1004
1005     .bdrv_detach_aio_context    = curl_detach_aio_context,
1006     .bdrv_attach_aio_context    = curl_attach_aio_context,
1007
1008     .bdrv_refresh_filename      = curl_refresh_filename,
1009     .strong_runtime_opts        = curl_strong_runtime_opts,
1010 };
1011
1012 static BlockDriver bdrv_ftp = {
1013     .format_name                = "ftp",
1014     .protocol_name              = "ftp",
1015
1016     .instance_size              = sizeof(BDRVCURLState),
1017     .bdrv_parse_filename        = curl_parse_filename,
1018     .bdrv_file_open             = curl_open,
1019     .bdrv_close                 = curl_close,
1020     .bdrv_getlength             = curl_getlength,
1021
1022     .bdrv_co_preadv             = curl_co_preadv,
1023
1024     .bdrv_detach_aio_context    = curl_detach_aio_context,
1025     .bdrv_attach_aio_context    = curl_attach_aio_context,
1026
1027     .bdrv_refresh_filename      = curl_refresh_filename,
1028     .strong_runtime_opts        = curl_strong_runtime_opts,
1029 };
1030
1031 static BlockDriver bdrv_ftps = {
1032     .format_name                = "ftps",
1033     .protocol_name              = "ftps",
1034
1035     .instance_size              = sizeof(BDRVCURLState),
1036     .bdrv_parse_filename        = curl_parse_filename,
1037     .bdrv_file_open             = curl_open,
1038     .bdrv_close                 = curl_close,
1039     .bdrv_getlength             = curl_getlength,
1040
1041     .bdrv_co_preadv             = curl_co_preadv,
1042
1043     .bdrv_detach_aio_context    = curl_detach_aio_context,
1044     .bdrv_attach_aio_context    = curl_attach_aio_context,
1045
1046     .bdrv_refresh_filename      = curl_refresh_filename,
1047     .strong_runtime_opts        = curl_strong_runtime_opts,
1048 };
1049
1050 static void curl_block_init(void)
1051 {
1052     bdrv_register(&bdrv_http);
1053     bdrv_register(&bdrv_https);
1054     bdrv_register(&bdrv_ftp);
1055     bdrv_register(&bdrv_ftps);
1056 }
1057
1058 block_init(curl_block_init);