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