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-io.h"
  31 #include "block/block_int.h"
  32 #include "qapi/qmp/qdict.h"
  33 #include "qapi/qmp/qstring.h"
  34 #include "crypto/secret.h"
  35 #include <curl/curl.h>
  36 #include "qemu/cutils.h"
  37 #include "trace.h"
  38
  39 // #define DEBUG_VERBOSE
  40
  41 /* CURL 7.85.0 switches to a string based API for specifying
  42  * the desired protocols.
  43  */
  44 #if LIBCURL_VERSION_NUM >= 0x075500
  45 #define PROTOCOLS "HTTP,HTTPS,FTP,FTPS"
  46 #else
  47 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  48                    CURLPROTO_FTP | CURLPROTO_FTPS)
  49 #endif
  50
  51 #define CURL_NUM_STATES 8
  52 #define CURL_NUM_ACB    8
  53 #define CURL_TIMEOUT_MAX 10000
  54
  55 #define CURL_BLOCK_OPT_URL       "url"
  56 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  57 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  58 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
  59 #define CURL_BLOCK_OPT_COOKIE    "cookie"
  60 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
  61 #define CURL_BLOCK_OPT_USERNAME "username"
  62 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
  63 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
  64 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
  65
  66 #define CURL_BLOCK_OPT_READAHEAD_DEFAULT (256 * 1024)
  67 #define CURL_BLOCK_OPT_SSLVERIFY_DEFAULT true
  68 #define CURL_BLOCK_OPT_TIMEOUT_DEFAULT 5
  69
  70 struct BDRVCURLState;
  71 struct CURLState;
  72
  73 static bool libcurl_initialized;
  74
  75 typedef struct CURLAIOCB {
  76     Coroutine *co;
  77     QEMUIOVector *qiov;
  78
  79     uint64_t offset;
  80     uint64_t bytes;
  81     int ret;
  82
  83     size_t start;
  84     size_t end;
  85 } CURLAIOCB;
  86
  87 typedef struct CURLSocket {
  88     int fd;
  89     struct BDRVCURLState *s;
  90 } CURLSocket;
  91
  92 typedef struct CURLState
  93 {
  94     struct BDRVCURLState *s;
  95     CURLAIOCB *acb[CURL_NUM_ACB];
  96     CURL *curl;
  97     char *orig_buf;
  98     uint64_t buf_start;
  99     size_t buf_off;
 100     size_t buf_len;
 101     char range[128];
 102     char errmsg[CURL_ERROR_SIZE];
 103     char in_use;
 104 } CURLState;
 105
 106 typedef struct BDRVCURLState {
 107     CURLM *multi;
 108     QEMUTimer timer;
 109     uint64_t len;
 110     CURLState states[CURL_NUM_STATES];
 111     GHashTable *sockets; /* GINT_TO_POINTER(fd) -> socket */
 112     char *url;
 113     size_t readahead_size;
 114     bool sslverify;
 115     uint64_t timeout;
 116     char *cookie;
 117     bool accept_range;
 118     AioContext *aio_context;
 119     QemuMutex mutex;
 120     CoQueue free_state_waitq;
 121     char *username;
 122     char *password;
 123     char *proxyusername;
 124     char *proxypassword;
 125 } BDRVCURLState;
 126
 127 static void curl_clean_state(CURLState *s);
 128 static void curl_multi_do(void *arg);
 129
 130 static gboolean curl_drop_socket(void *key, void *value, void *opaque)
 131 {
 132     CURLSocket *socket = value;
 133     BDRVCURLState *s = socket->s;
 134
 135     aio_set_fd_handler(s->aio_context, socket->fd, false,
 136                        NULL, NULL, NULL, NULL, NULL);
 137     return true;
 138 }
 139
 140 static void curl_drop_all_sockets(GHashTable *sockets)
 141 {
 142     g_hash_table_foreach_remove(sockets, curl_drop_socket, NULL);
 143 }
 144
 145 /* Called from curl_multi_do_locked, with s->mutex held.  */
 146 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 147 {
 148     BDRVCURLState *s = opaque;
 149
 150     trace_curl_timer_cb(timeout_ms);
 151     if (timeout_ms == -1) {
 152         timer_del(&s->timer);
 153     } else {
 154         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 155         timer_mod(&s->timer,
 156                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 157     }
 158     return 0;
 159 }
 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     socket = g_hash_table_lookup(s->sockets, GINT_TO_POINTER(fd));
 173     if (!socket) {
 174         socket = g_new0(CURLSocket, 1);
 175         socket->fd = fd;
 176         socket->s = s;
 177         g_hash_table_insert(s->sockets, GINT_TO_POINTER(fd), socket);
 178     }
 179
 180     trace_curl_sock_cb(action, (int)fd);
 181     switch (action) {
 182         case CURL_POLL_IN:
 183             aio_set_fd_handler(s->aio_context, fd, false,
 184                                curl_multi_do, NULL, NULL, NULL, socket);
 185             break;
 186         case CURL_POLL_OUT:
 187             aio_set_fd_handler(s->aio_context, fd, false,
 188                                NULL, curl_multi_do, NULL, NULL, socket);
 189             break;
 190         case CURL_POLL_INOUT:
 191             aio_set_fd_handler(s->aio_context, fd, false,
 192                                curl_multi_do, curl_multi_do,
 193                                NULL, NULL, socket);
 194             break;
 195         case CURL_POLL_REMOVE:
 196             aio_set_fd_handler(s->aio_context, fd, false,
 197                                NULL, NULL, NULL, NULL, NULL);
 198             break;
 199     }
 200
 201     if (action == CURL_POLL_REMOVE) {
 202         g_hash_table_remove(s->sockets, GINT_TO_POINTER(fd));
 203     }
 204
 205     return 0;
 206 }
 207
 208 /* Called from curl_multi_do_locked, with s->mutex held.  */
 209 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 210 {
 211     BDRVCURLState *s = opaque;
 212     size_t realsize = size * nmemb;
 213     const char *header = (char *)ptr;
 214     const char *end = header + realsize;
 215     const char *accept_ranges = "accept-ranges:";
 216     const char *bytes = "bytes";
 217
 218     if (realsize >= strlen(accept_ranges)
 219         && g_ascii_strncasecmp(header, accept_ranges,
 220                                strlen(accept_ranges)) == 0) {
 221
 222         char *p = strchr(header, ':') + 1;
 223
 224         /* Skip whitespace between the header name and value. */
 225         while (p < end && *p && g_ascii_isspace(*p)) {
 226             p++;
 227         }
 228
 229         if (end - p >= strlen(bytes)
 230             && strncmp(p, bytes, strlen(bytes)) == 0) {
 231
 232             /* Check that there is nothing but whitespace after the value. */
 233             p += strlen(bytes);
 234             while (p < end && *p && g_ascii_isspace(*p)) {
 235                 p++;
 236             }
 237
 238             if (p == end || !*p) {
 239                 s->accept_range = true;
 240             }
 241         }
 242     }
 243
 244     return realsize;
 245 }
 246
 247 /* Called from curl_multi_do_locked, with s->mutex held.  */
 248 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 249 {
 250     CURLState *s = ((CURLState*)opaque);
 251     size_t realsize = size * nmemb;
 252
 253     trace_curl_read_cb(realsize);
 254
 255     if (!s || !s->orig_buf) {
 256         goto read_end;
 257     }
 258
 259     if (s->buf_off >= s->buf_len) {
 260         /* buffer full, read nothing */
 261         goto read_end;
 262     }
 263     realsize = MIN(realsize, s->buf_len - s->buf_off);
 264     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 265     s->buf_off += realsize;
 266
 267 read_end:
 268     /* curl will error out if we do not return this value */
 269     return size * nmemb;
 270 }
 271
 272 /* Called with s->mutex held.  */
 273 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
 274                           CURLAIOCB *acb)
 275 {
 276     int i;
 277     uint64_t end = start + len;
 278     uint64_t clamped_end = MIN(end, s->len);
 279     uint64_t clamped_len = clamped_end - start;
 280
 281     for (i=0; i<CURL_NUM_STATES; i++) {
 282         CURLState *state = &s->states[i];
 283         uint64_t buf_end = (state->buf_start + state->buf_off);
 284         uint64_t buf_fend = (state->buf_start + state->buf_len);
 285
 286         if (!state->orig_buf)
 287             continue;
 288         if (!state->buf_off)
 289             continue;
 290
 291         // Does the existing buffer cover our section?
 292         if ((start >= state->buf_start) &&
 293             (start <= buf_end) &&
 294             (clamped_end >= state->buf_start) &&
 295             (clamped_end <= buf_end))
 296         {
 297             char *buf = state->orig_buf + (start - state->buf_start);
 298
 299             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
 300             if (clamped_len < len) {
 301                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
 302             }
 303             acb->ret = 0;
 304             return true;
 305         }
 306
 307         // Wait for unfinished chunks
 308         if (state->in_use &&
 309             (start >= state->buf_start) &&
 310             (start <= buf_fend) &&
 311             (clamped_end >= state->buf_start) &&
 312             (clamped_end <= buf_fend))
 313         {
 314             int j;
 315
 316             acb->start = start - state->buf_start;
 317             acb->end = acb->start + clamped_len;
 318
 319             for (j=0; j<CURL_NUM_ACB; j++) {
 320                 if (!state->acb[j]) {
 321                     state->acb[j] = acb;
 322                     return true;
 323                 }
 324             }
 325         }
 326     }
 327
 328     return false;
 329 }
 330
 331 /* Called with s->mutex held.  */
 332 static void curl_multi_check_completion(BDRVCURLState *s)
 333 {
 334     int msgs_in_queue;
 335
 336     /* Try to find done transfers, so we can free the easy
 337      * handle again. */
 338     for (;;) {
 339         CURLMsg *msg;
 340         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 341
 342         /* Quit when there are no more completions */
 343         if (!msg)
 344             break;
 345
 346         if (msg->msg == CURLMSG_DONE) {
 347             int i;
 348             CURLState *state = NULL;
 349             bool error = msg->data.result != CURLE_OK;
 350
 351             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 352                               (char **)&state);
 353
 354             if (error) {
 355                 static int errcount = 100;
 356
 357                 /* Don't lose the original error message from curl, since
 358                  * it contains extra data.
 359                  */
 360                 if (errcount > 0) {
 361                     error_report("curl: %s", state->errmsg);
 362                     if (--errcount == 0) {
 363                         error_report("curl: further errors suppressed");
 364                     }
 365                 }
 366             }
 367
 368             for (i = 0; i < CURL_NUM_ACB; i++) {
 369                 CURLAIOCB *acb = state->acb[i];
 370
 371                 if (acb == NULL) {
 372                     continue;
 373                 }
 374
 375                 if (!error) {
 376                     /* Assert that we have read all data */
 377                     assert(state->buf_off >= acb->end);
 378
 379                     qemu_iovec_from_buf(acb->qiov, 0,
 380                                         state->orig_buf + acb->start,
 381                                         acb->end - acb->start);
 382
 383                     if (acb->end - acb->start < acb->bytes) {
 384                         size_t offset = acb->end - acb->start;
 385                         qemu_iovec_memset(acb->qiov, offset, 0,
 386                                           acb->bytes - offset);
 387                     }
 388                 }
 389
 390                 acb->ret = error ? -EIO : 0;
 391                 state->acb[i] = NULL;
 392                 qemu_mutex_unlock(&s->mutex);
 393                 aio_co_wake(acb->co);
 394                 qemu_mutex_lock(&s->mutex);
 395             }
 396
 397             curl_clean_state(state);
 398             break;
 399         }
 400     }
 401 }
 402
 403 /* Called with s->mutex held.  */
 404 static void curl_multi_do_locked(CURLSocket *socket)
 405 {
 406     BDRVCURLState *s = socket->s;
 407     int running;
 408     int r;
 409
 410     if (!s->multi) {
 411         return;
 412     }
 413
 414     do {
 415         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
 416     } while (r == CURLM_CALL_MULTI_PERFORM);
 417 }
 418
 419 static void curl_multi_do(void *arg)
 420 {
 421     CURLSocket *socket = arg;
 422     BDRVCURLState *s = socket->s;
 423
 424     qemu_mutex_lock(&s->mutex);
 425     curl_multi_do_locked(socket);
 426     curl_multi_check_completion(s);
 427     qemu_mutex_unlock(&s->mutex);
 428 }
 429
 430 static void curl_multi_timeout_do(void *arg)
 431 {
 432     BDRVCURLState *s = (BDRVCURLState *)arg;
 433     int running;
 434
 435     if (!s->multi) {
 436         return;
 437     }
 438
 439     qemu_mutex_lock(&s->mutex);
 440     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 441
 442     curl_multi_check_completion(s);
 443     qemu_mutex_unlock(&s->mutex);
 444 }
 445
 446 /* Called with s->mutex held.  */
 447 static CURLState *curl_find_state(BDRVCURLState *s)
 448 {
 449     CURLState *state = NULL;
 450     int i;
 451
 452     for (i = 0; i < CURL_NUM_STATES; i++) {
 453         if (!s->states[i].in_use) {
 454             state = &s->states[i];
 455             state->in_use = 1;
 456             break;
 457         }
 458     }
 459     return state;
 460 }
 461
 462 static int curl_init_state(BDRVCURLState *s, CURLState *state)
 463 {
 464     if (!state->curl) {
 465         state->curl = curl_easy_init();
 466         if (!state->curl) {
 467             return -EIO;
 468         }
 469         if (curl_easy_setopt(state->curl, CURLOPT_URL, s->url) ||
 470             curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 471                              (long) s->sslverify) ||
 472             curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
 473                              s->sslverify ? 2L : 0L)) {
 474             goto err;
 475         }
 476         if (s->cookie) {
 477             if (curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie)) {
 478                 goto err;
 479             }
 480         }
 481         if (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             goto err;
 492         }
 493         if (s->username) {
 494             if (curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username)) {
 495                 goto err;
 496             }
 497         }
 498         if (s->password) {
 499             if (curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password)) {
 500                 goto err;
 501             }
 502         }
 503         if (s->proxyusername) {
 504             if (curl_easy_setopt(state->curl,
 505                                  CURLOPT_PROXYUSERNAME, s->proxyusername)) {
 506                 goto err;
 507             }
 508         }
 509         if (s->proxypassword) {
 510             if (curl_easy_setopt(state->curl,
 511                                  CURLOPT_PROXYPASSWORD, s->proxypassword)) {
 512                 goto err;
 513             }
 514         }
 515
 516         /* Restrict supported protocols to avoid security issues in the more
 517          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 518          * CVE-2013-0249.
 519          *
 520          * Restricting protocols is only supported from 7.19.4 upwards. Note:
 521          * version 7.85.0 deprecates CURLOPT_*PROTOCOLS in favour of a string
 522          * based CURLOPT_*PROTOCOLS_STR API.
 523          */
 524 #if LIBCURL_VERSION_NUM >= 0x075500
 525         if (curl_easy_setopt(state->curl,
 526                              CURLOPT_PROTOCOLS_STR, PROTOCOLS) ||
 527             curl_easy_setopt(state->curl,
 528                              CURLOPT_REDIR_PROTOCOLS_STR, PROTOCOLS)) {
 529             goto err;
 530         }
 531 #elif LIBCURL_VERSION_NUM >= 0x071304
 532         if (curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS) ||
 533             curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS)) {
 534             goto err;
 535         }
 536 #endif
 537
 538 #ifdef DEBUG_VERBOSE
 539         if (curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1)) {
 540             goto err;
 541         }
 542 #endif
 543     }
 544
 545     state->s = s;
 546
 547     return 0;
 548
 549 err:
 550     curl_easy_cleanup(state->curl);
 551     state->curl = NULL;
 552     return -EIO;
 553 }
 554
 555 /* Called with s->mutex held.  */
 556 static void curl_clean_state(CURLState *s)
 557 {
 558     int j;
 559     for (j = 0; j < CURL_NUM_ACB; j++) {
 560         assert(!s->acb[j]);
 561     }
 562
 563     if (s->s->multi)
 564         curl_multi_remove_handle(s->s->multi, s->curl);
 565
 566     s->in_use = 0;
 567
 568     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
 569 }
 570
 571 static void curl_parse_filename(const char *filename, QDict *options,
 572                                 Error **errp)
 573 {
 574     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
 575 }
 576
 577 static void curl_detach_aio_context(BlockDriverState *bs)
 578 {
 579     BDRVCURLState *s = bs->opaque;
 580     int i;
 581
 582     WITH_QEMU_LOCK_GUARD(&s->mutex) {
 583         curl_drop_all_sockets(s->sockets);
 584         for (i = 0; i < CURL_NUM_STATES; i++) {
 585             if (s->states[i].in_use) {
 586                 curl_clean_state(&s->states[i]);
 587             }
 588             if (s->states[i].curl) {
 589                 curl_easy_cleanup(s->states[i].curl);
 590                 s->states[i].curl = NULL;
 591             }
 592             g_free(s->states[i].orig_buf);
 593             s->states[i].orig_buf = NULL;
 594         }
 595         if (s->multi) {
 596             curl_multi_cleanup(s->multi);
 597             s->multi = NULL;
 598         }
 599     }
 600
 601     timer_del(&s->timer);
 602 }
 603
 604 static void curl_attach_aio_context(BlockDriverState *bs,
 605                                     AioContext *new_context)
 606 {
 607     BDRVCURLState *s = bs->opaque;
 608
 609     aio_timer_init(new_context, &s->timer,
 610                    QEMU_CLOCK_REALTIME, SCALE_NS,
 611                    curl_multi_timeout_do, s);
 612
 613     assert(!s->multi);
 614     s->multi = curl_multi_init();
 615     s->aio_context = new_context;
 616     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 617     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 618     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 619 }
 620
 621 static QemuOptsList runtime_opts = {
 622     .name = "curl",
 623     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 624     .desc = {
 625         {
 626             .name = CURL_BLOCK_OPT_URL,
 627             .type = QEMU_OPT_STRING,
 628             .help = "URL to open",
 629         },
 630         {
 631             .name = CURL_BLOCK_OPT_READAHEAD,
 632             .type = QEMU_OPT_SIZE,
 633             .help = "Readahead size",
 634         },
 635         {
 636             .name = CURL_BLOCK_OPT_SSLVERIFY,
 637             .type = QEMU_OPT_BOOL,
 638             .help = "Verify SSL certificate"
 639         },
 640         {
 641             .name = CURL_BLOCK_OPT_TIMEOUT,
 642             .type = QEMU_OPT_NUMBER,
 643             .help = "Curl timeout"
 644         },
 645         {
 646             .name = CURL_BLOCK_OPT_COOKIE,
 647             .type = QEMU_OPT_STRING,
 648             .help = "Pass the cookie or list of cookies with each request"
 649         },
 650         {
 651             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
 652             .type = QEMU_OPT_STRING,
 653             .help = "ID of secret used as cookie passed with each request"
 654         },
 655         {
 656             .name = CURL_BLOCK_OPT_USERNAME,
 657             .type = QEMU_OPT_STRING,
 658             .help = "Username for HTTP auth"
 659         },
 660         {
 661             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 662             .type = QEMU_OPT_STRING,
 663             .help = "ID of secret used as password for HTTP auth",
 664         },
 665         {
 666             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 667             .type = QEMU_OPT_STRING,
 668             .help = "Username for HTTP proxy auth"
 669         },
 670         {
 671             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 672             .type = QEMU_OPT_STRING,
 673             .help = "ID of secret used as password for HTTP proxy auth",
 674         },
 675         { /* end of list */ }
 676     },
 677 };
 678
 679
 680 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 681                      Error **errp)
 682 {
 683     BDRVCURLState *s = bs->opaque;
 684     CURLState *state = NULL;
 685     QemuOpts *opts;
 686     const char *file;
 687     const char *cookie;
 688     const char *cookie_secret;
 689     /* CURL >= 7.55.0 uses curl_off_t for content length instead of a double */
 690 #if LIBCURL_VERSION_NUM >= 0x073700
 691     curl_off_t cl;
 692 #else
 693     double cl;
 694 #endif
 695     const char *secretid;
 696     const char *protocol_delimiter;
 697     int ret;
 698
 699     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
 700                                     errp);
 701     if (ret < 0) {
 702         return ret;
 703     }
 704
 705     if (!libcurl_initialized) {
 706         ret = curl_global_init(CURL_GLOBAL_ALL);
 707         if (ret) {
 708             error_setg(errp, "libcurl initialization failed with %d", ret);
 709             return -EIO;
 710         }
 711         libcurl_initialized = true;
 712     }
 713
 714     qemu_mutex_init(&s->mutex);
 715     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 716     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
 717         goto out_noclean;
 718     }
 719
 720     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 721                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
 722     if ((s->readahead_size & 0x1ff) != 0) {
 723         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 724                    s->readahead_size);
 725         goto out_noclean;
 726     }
 727
 728     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 729                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
 730     if (s->timeout > CURL_TIMEOUT_MAX) {
 731         error_setg(errp, "timeout parameter is too large or negative");
 732         goto out_noclean;
 733     }
 734
 735     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
 736                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
 737
 738     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 739     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
 740
 741     if (cookie && cookie_secret) {
 742         error_setg(errp,
 743                    "curl driver cannot handle both cookie and cookie secret");
 744         goto out_noclean;
 745     }
 746
 747     if (cookie_secret) {
 748         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
 749         if (!s->cookie) {
 750             goto out_noclean;
 751         }
 752     } else {
 753         s->cookie = g_strdup(cookie);
 754     }
 755
 756     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 757     if (file == NULL) {
 758         error_setg(errp, "curl block driver requires an 'url' option");
 759         goto out_noclean;
 760     }
 761
 762     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
 763         !strstart(protocol_delimiter, "://", NULL))
 764     {
 765         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
 766                    "start with '%s://')", bs->drv->protocol_name, file,
 767                    bs->drv->protocol_name);
 768         goto out_noclean;
 769     }
 770
 771     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 772     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 773
 774     if (secretid) {
 775         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 776         if (!s->password) {
 777             goto out_noclean;
 778         }
 779     }
 780
 781     s->proxyusername = g_strdup(
 782         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 783     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 784     if (secretid) {
 785         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 786         if (!s->proxypassword) {
 787             goto out_noclean;
 788         }
 789     }
 790
 791     trace_curl_open(file);
 792     qemu_co_queue_init(&s->free_state_waitq);
 793     s->aio_context = bdrv_get_aio_context(bs);
 794     s->url = g_strdup(file);
 795     s->sockets = g_hash_table_new_full(NULL, NULL, NULL, g_free);
 796     qemu_mutex_lock(&s->mutex);
 797     state = curl_find_state(s);
 798     qemu_mutex_unlock(&s->mutex);
 799     if (!state) {
 800         goto out_noclean;
 801     }
 802
 803     // Get file size
 804
 805     if (curl_init_state(s, state) < 0) {
 806         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 807                 "curl library initialization failed.");
 808         goto out;
 809     }
 810
 811     s->accept_range = false;
 812     if (curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1) ||
 813         curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION, curl_header_cb) ||
 814         curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s)) {
 815         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 816                 "curl library initialization failed.");
 817         goto out;
 818     }
 819     if (curl_easy_perform(state->curl))
 820         goto out;
 821     /* CURL 7.55.0 deprecates CURLINFO_CONTENT_LENGTH_DOWNLOAD in favour of
 822      * the *_T version which returns a more sensible type for content length.
 823      */
 824 #if LIBCURL_VERSION_NUM >= 0x073700
 825     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD_T, &cl)) {
 826         goto out;
 827     }
 828 #else
 829     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &cl)) {
 830         goto out;
 831     }
 832 #endif
 833     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
 834      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
 835      * known and zero if it is really zero-length file. */
 836 #if LIBCURL_VERSION_NUM >= 0x071304
 837     if (cl < 0) {
 838         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 839                 "Server didn't report file size.");
 840         goto out;
 841     }
 842 #else
 843     if (cl <= 0) {
 844         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 845                 "Unknown file size or zero-length file.");
 846         goto out;
 847     }
 848 #endif
 849
 850     s->len = cl;
 851
 852     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 853         || !strncasecmp(s->url, "https://", strlen("https://")))
 854         && !s->accept_range) {
 855         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 856                 "Server does not support 'range' (byte ranges).");
 857         goto out;
 858     }
 859     trace_curl_open_size(s->len);
 860
 861     qemu_mutex_lock(&s->mutex);
 862     curl_clean_state(state);
 863     qemu_mutex_unlock(&s->mutex);
 864     curl_easy_cleanup(state->curl);
 865     state->curl = NULL;
 866
 867     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 868
 869     qemu_opts_del(opts);
 870     return 0;
 871
 872 out:
 873     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 874     curl_easy_cleanup(state->curl);
 875     state->curl = NULL;
 876 out_noclean:
 877     qemu_mutex_destroy(&s->mutex);
 878     g_free(s->cookie);
 879     g_free(s->url);
 880     g_free(s->username);
 881     g_free(s->proxyusername);
 882     g_free(s->proxypassword);
 883     if (s->sockets) {
 884         curl_drop_all_sockets(s->sockets);
 885         g_hash_table_destroy(s->sockets);
 886     }
 887     qemu_opts_del(opts);
 888     return -EINVAL;
 889 }
 890
 891 static void coroutine_fn curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
 892 {
 893     CURLState *state;
 894     int running;
 895
 896     BDRVCURLState *s = bs->opaque;
 897
 898     uint64_t start = acb->offset;
 899     uint64_t end;
 900
 901     qemu_mutex_lock(&s->mutex);
 902
 903     // In case we have the requested data already (e.g. read-ahead),
 904     // we can just call the callback and be done.
 905     if (curl_find_buf(s, start, acb->bytes, acb)) {
 906         goto out;
 907     }
 908
 909     // No cache found, so let's start a new request
 910     for (;;) {
 911         state = curl_find_state(s);
 912         if (state) {
 913             break;
 914         }
 915         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
 916     }
 917
 918     if (curl_init_state(s, state) < 0) {
 919         curl_clean_state(state);
 920         acb->ret = -EIO;
 921         goto out;
 922     }
 923
 924     acb->start = 0;
 925     acb->end = MIN(acb->bytes, s->len - start);
 926
 927     state->buf_off = 0;
 928     g_free(state->orig_buf);
 929     state->buf_start = start;
 930     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
 931     end = start + state->buf_len - 1;
 932     state->orig_buf = g_try_malloc(state->buf_len);
 933     if (state->buf_len && state->orig_buf == NULL) {
 934         curl_clean_state(state);
 935         acb->ret = -ENOMEM;
 936         goto out;
 937     }
 938     state->acb[0] = acb;
 939
 940     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
 941     trace_curl_setup_preadv(acb->bytes, start, state->range);
 942     if (curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range) ||
 943         curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
 944         state->acb[0] = NULL;
 945         acb->ret = -EIO;
 946
 947         curl_clean_state(state);
 948         goto out;
 949     }
 950
 951     /* Tell curl it needs to kick things off */
 952     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 953
 954 out:
 955     qemu_mutex_unlock(&s->mutex);
 956 }
 957
 958 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
 959         int64_t offset, int64_t bytes, QEMUIOVector *qiov,
 960         BdrvRequestFlags flags)
 961 {
 962     CURLAIOCB acb = {
 963         .co = qemu_coroutine_self(),
 964         .ret = -EINPROGRESS,
 965         .qiov = qiov,
 966         .offset = offset,
 967         .bytes = bytes
 968     };
 969
 970     curl_setup_preadv(bs, &acb);
 971     while (acb.ret == -EINPROGRESS) {
 972         qemu_coroutine_yield();
 973     }
 974     return acb.ret;
 975 }
 976
 977 static void curl_close(BlockDriverState *bs)
 978 {
 979     BDRVCURLState *s = bs->opaque;
 980
 981     trace_curl_close();
 982     curl_detach_aio_context(bs);
 983     qemu_mutex_destroy(&s->mutex);
 984
 985     g_hash_table_destroy(s->sockets);
 986     g_free(s->cookie);
 987     g_free(s->url);
 988     g_free(s->username);
 989     g_free(s->proxyusername);
 990     g_free(s->proxypassword);
 991 }
 992
 993 static int64_t coroutine_fn curl_co_getlength(BlockDriverState *bs)
 994 {
 995     BDRVCURLState *s = bs->opaque;
 996     return s->len;
 997 }
 998
 999 static void curl_refresh_filename(BlockDriverState *bs)
1000 {
1001     BDRVCURLState *s = bs->opaque;
1002
1003     /* "readahead" and "timeout" do not change the guest-visible data,
1004      * so ignore them */
1005     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
1006         s->cookie || s->username || s->password || s->proxyusername ||
1007         s->proxypassword)
1008     {
1009         return;
1010     }
1011
1012     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
1013 }
1014
1015
1016 static const char *const curl_strong_runtime_opts[] = {
1017     CURL_BLOCK_OPT_URL,
1018     CURL_BLOCK_OPT_SSLVERIFY,
1019     CURL_BLOCK_OPT_COOKIE,
1020     CURL_BLOCK_OPT_COOKIE_SECRET,
1021     CURL_BLOCK_OPT_USERNAME,
1022     CURL_BLOCK_OPT_PASSWORD_SECRET,
1023     CURL_BLOCK_OPT_PROXY_USERNAME,
1024     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
1025
1026     NULL
1027 };
1028
1029 static BlockDriver bdrv_http = {
1030     .format_name                = "http",
1031     .protocol_name              = "http",
1032
1033     .instance_size              = sizeof(BDRVCURLState),
1034     .bdrv_parse_filename        = curl_parse_filename,
1035     .bdrv_file_open             = curl_open,
1036     .bdrv_close                 = curl_close,
1037     .bdrv_co_getlength          = curl_co_getlength,
1038
1039     .bdrv_co_preadv             = curl_co_preadv,
1040
1041     .bdrv_detach_aio_context    = curl_detach_aio_context,
1042     .bdrv_attach_aio_context    = curl_attach_aio_context,
1043
1044     .bdrv_refresh_filename      = curl_refresh_filename,
1045     .strong_runtime_opts        = curl_strong_runtime_opts,
1046 };
1047
1048 static BlockDriver bdrv_https = {
1049     .format_name                = "https",
1050     .protocol_name              = "https",
1051
1052     .instance_size              = sizeof(BDRVCURLState),
1053     .bdrv_parse_filename        = curl_parse_filename,
1054     .bdrv_file_open             = curl_open,
1055     .bdrv_close                 = curl_close,
1056     .bdrv_co_getlength          = curl_co_getlength,
1057
1058     .bdrv_co_preadv             = curl_co_preadv,
1059
1060     .bdrv_detach_aio_context    = curl_detach_aio_context,
1061     .bdrv_attach_aio_context    = curl_attach_aio_context,
1062
1063     .bdrv_refresh_filename      = curl_refresh_filename,
1064     .strong_runtime_opts        = curl_strong_runtime_opts,
1065 };
1066
1067 static BlockDriver bdrv_ftp = {
1068     .format_name                = "ftp",
1069     .protocol_name              = "ftp",
1070
1071     .instance_size              = sizeof(BDRVCURLState),
1072     .bdrv_parse_filename        = curl_parse_filename,
1073     .bdrv_file_open             = curl_open,
1074     .bdrv_close                 = curl_close,
1075     .bdrv_co_getlength          = curl_co_getlength,
1076
1077     .bdrv_co_preadv             = curl_co_preadv,
1078
1079     .bdrv_detach_aio_context    = curl_detach_aio_context,
1080     .bdrv_attach_aio_context    = curl_attach_aio_context,
1081
1082     .bdrv_refresh_filename      = curl_refresh_filename,
1083     .strong_runtime_opts        = curl_strong_runtime_opts,
1084 };
1085
1086 static BlockDriver bdrv_ftps = {
1087     .format_name                = "ftps",
1088     .protocol_name              = "ftps",
1089
1090     .instance_size              = sizeof(BDRVCURLState),
1091     .bdrv_parse_filename        = curl_parse_filename,
1092     .bdrv_file_open             = curl_open,
1093     .bdrv_close                 = curl_close,
1094     .bdrv_co_getlength          = curl_co_getlength,
1095
1096     .bdrv_co_preadv             = curl_co_preadv,
1097
1098     .bdrv_detach_aio_context    = curl_detach_aio_context,
1099     .bdrv_attach_aio_context    = curl_attach_aio_context,
1100
1101     .bdrv_refresh_filename      = curl_refresh_filename,
1102     .strong_runtime_opts        = curl_strong_runtime_opts,
1103 };
1104
1105 static void curl_block_init(void)
1106 {
1107     bdrv_register(&bdrv_http);
1108     bdrv_register(&bdrv_https);
1109     bdrv_register(&bdrv_ftp);
1110     bdrv_register(&bdrv_ftps);
1111 }
1112
1113 block_init(curl_block_init);