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 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  42                    CURLPROTO_FTP | CURLPROTO_FTPS)
  43
  44 #define CURL_NUM_STATES 8
  45 #define CURL_NUM_ACB    8
  46 #define CURL_TIMEOUT_MAX 10000
  47
  48 #define CURL_BLOCK_OPT_URL       "url"
  49 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  50 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  51 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
  52 #define CURL_BLOCK_OPT_COOKIE    "cookie"
  53 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
  54 #define CURL_BLOCK_OPT_USERNAME "username"
  55 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
  56 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
  57 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
  58
  59 #define CURL_BLOCK_OPT_READAHEAD_DEFAULT (256 * 1024)
  60 #define CURL_BLOCK_OPT_SSLVERIFY_DEFAULT true
  61 #define CURL_BLOCK_OPT_TIMEOUT_DEFAULT 5
  62
  63 struct BDRVCURLState;
  64 struct CURLState;
  65
  66 static bool libcurl_initialized;
  67
  68 typedef struct CURLAIOCB {
  69     Coroutine *co;
  70     QEMUIOVector *qiov;
  71
  72     uint64_t offset;
  73     uint64_t bytes;
  74     int ret;
  75
  76     size_t start;
  77     size_t end;
  78 } CURLAIOCB;
  79
  80 typedef struct CURLSocket {
  81     int fd;
  82     struct BDRVCURLState *s;
  83 } CURLSocket;
  84
  85 typedef struct CURLState
  86 {
  87     struct BDRVCURLState *s;
  88     CURLAIOCB *acb[CURL_NUM_ACB];
  89     CURL *curl;
  90     char *orig_buf;
  91     uint64_t buf_start;
  92     size_t buf_off;
  93     size_t buf_len;
  94     char range[128];
  95     char errmsg[CURL_ERROR_SIZE];
  96     char in_use;
  97 } CURLState;
  98
  99 typedef struct BDRVCURLState {
 100     CURLM *multi;
 101     QEMUTimer timer;
 102     uint64_t len;
 103     CURLState states[CURL_NUM_STATES];
 104     GHashTable *sockets; /* GINT_TO_POINTER(fd) -> socket */
 105     char *url;
 106     size_t readahead_size;
 107     bool sslverify;
 108     uint64_t timeout;
 109     char *cookie;
 110     bool accept_range;
 111     AioContext *aio_context;
 112     QemuMutex mutex;
 113     CoQueue free_state_waitq;
 114     char *username;
 115     char *password;
 116     char *proxyusername;
 117     char *proxypassword;
 118 } BDRVCURLState;
 119
 120 static void curl_clean_state(CURLState *s);
 121 static void curl_multi_do(void *arg);
 122
 123 static gboolean curl_drop_socket(void *key, void *value, void *opaque)
 124 {
 125     CURLSocket *socket = value;
 126     BDRVCURLState *s = socket->s;
 127
 128     aio_set_fd_handler(s->aio_context, socket->fd, false,
 129                        NULL, NULL, NULL, NULL, NULL);
 130     return true;
 131 }
 132
 133 static void curl_drop_all_sockets(GHashTable *sockets)
 134 {
 135     g_hash_table_foreach_remove(sockets, curl_drop_socket, NULL);
 136 }
 137
 138 /* Called from curl_multi_do_locked, with s->mutex held.  */
 139 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 140 {
 141     BDRVCURLState *s = opaque;
 142
 143     trace_curl_timer_cb(timeout_ms);
 144     if (timeout_ms == -1) {
 145         timer_del(&s->timer);
 146     } else {
 147         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 148         timer_mod(&s->timer,
 149                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 150     }
 151     return 0;
 152 }
 153
 154 /* Called from curl_multi_do_locked, with s->mutex held.  */
 155 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 156                         void *userp, void *sp)
 157 {
 158     BDRVCURLState *s;
 159     CURLState *state = NULL;
 160     CURLSocket *socket;
 161
 162     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 163     s = state->s;
 164
 165     socket = g_hash_table_lookup(s->sockets, GINT_TO_POINTER(fd));
 166     if (!socket) {
 167         socket = g_new0(CURLSocket, 1);
 168         socket->fd = fd;
 169         socket->s = s;
 170         g_hash_table_insert(s->sockets, GINT_TO_POINTER(fd), socket);
 171     }
 172
 173     trace_curl_sock_cb(action, (int)fd);
 174     switch (action) {
 175         case CURL_POLL_IN:
 176             aio_set_fd_handler(s->aio_context, fd, false,
 177                                curl_multi_do, NULL, NULL, NULL, socket);
 178             break;
 179         case CURL_POLL_OUT:
 180             aio_set_fd_handler(s->aio_context, fd, false,
 181                                NULL, curl_multi_do, NULL, NULL, socket);
 182             break;
 183         case CURL_POLL_INOUT:
 184             aio_set_fd_handler(s->aio_context, fd, false,
 185                                curl_multi_do, curl_multi_do,
 186                                NULL, NULL, socket);
 187             break;
 188         case CURL_POLL_REMOVE:
 189             aio_set_fd_handler(s->aio_context, fd, false,
 190                                NULL, NULL, NULL, NULL, NULL);
 191             break;
 192     }
 193
 194     if (action == CURL_POLL_REMOVE) {
 195         g_hash_table_remove(s->sockets, GINT_TO_POINTER(fd));
 196     }
 197
 198     return 0;
 199 }
 200
 201 /* Called from curl_multi_do_locked, with s->mutex held.  */
 202 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 203 {
 204     BDRVCURLState *s = opaque;
 205     size_t realsize = size * nmemb;
 206     const char *header = (char *)ptr;
 207     const char *end = header + realsize;
 208     const char *accept_ranges = "accept-ranges:";
 209     const char *bytes = "bytes";
 210
 211     if (realsize >= strlen(accept_ranges)
 212         && g_ascii_strncasecmp(header, accept_ranges,
 213                                strlen(accept_ranges)) == 0) {
 214
 215         char *p = strchr(header, ':') + 1;
 216
 217         /* Skip whitespace between the header name and value. */
 218         while (p < end && *p && g_ascii_isspace(*p)) {
 219             p++;
 220         }
 221
 222         if (end - p >= strlen(bytes)
 223             && strncmp(p, bytes, strlen(bytes)) == 0) {
 224
 225             /* Check that there is nothing but whitespace after the value. */
 226             p += strlen(bytes);
 227             while (p < end && *p && g_ascii_isspace(*p)) {
 228                 p++;
 229             }
 230
 231             if (p == end || !*p) {
 232                 s->accept_range = true;
 233             }
 234         }
 235     }
 236
 237     return realsize;
 238 }
 239
 240 /* Called from curl_multi_do_locked, with s->mutex held.  */
 241 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 242 {
 243     CURLState *s = ((CURLState*)opaque);
 244     size_t realsize = size * nmemb;
 245
 246     trace_curl_read_cb(realsize);
 247
 248     if (!s || !s->orig_buf) {
 249         goto read_end;
 250     }
 251
 252     if (s->buf_off >= s->buf_len) {
 253         /* buffer full, read nothing */
 254         goto read_end;
 255     }
 256     realsize = MIN(realsize, s->buf_len - s->buf_off);
 257     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 258     s->buf_off += realsize;
 259
 260 read_end:
 261     /* curl will error out if we do not return this value */
 262     return size * nmemb;
 263 }
 264
 265 /* Called with s->mutex held.  */
 266 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
 267                           CURLAIOCB *acb)
 268 {
 269     int i;
 270     uint64_t end = start + len;
 271     uint64_t clamped_end = MIN(end, s->len);
 272     uint64_t clamped_len = clamped_end - start;
 273
 274     for (i=0; i<CURL_NUM_STATES; i++) {
 275         CURLState *state = &s->states[i];
 276         uint64_t buf_end = (state->buf_start + state->buf_off);
 277         uint64_t buf_fend = (state->buf_start + state->buf_len);
 278
 279         if (!state->orig_buf)
 280             continue;
 281         if (!state->buf_off)
 282             continue;
 283
 284         // Does the existing buffer cover our section?
 285         if ((start >= state->buf_start) &&
 286             (start <= buf_end) &&
 287             (clamped_end >= state->buf_start) &&
 288             (clamped_end <= buf_end))
 289         {
 290             char *buf = state->orig_buf + (start - state->buf_start);
 291
 292             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
 293             if (clamped_len < len) {
 294                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
 295             }
 296             acb->ret = 0;
 297             return true;
 298         }
 299
 300         // Wait for unfinished chunks
 301         if (state->in_use &&
 302             (start >= state->buf_start) &&
 303             (start <= buf_fend) &&
 304             (clamped_end >= state->buf_start) &&
 305             (clamped_end <= buf_fend))
 306         {
 307             int j;
 308
 309             acb->start = start - state->buf_start;
 310             acb->end = acb->start + clamped_len;
 311
 312             for (j=0; j<CURL_NUM_ACB; j++) {
 313                 if (!state->acb[j]) {
 314                     state->acb[j] = acb;
 315                     return true;
 316                 }
 317             }
 318         }
 319     }
 320
 321     return false;
 322 }
 323
 324 /* Called with s->mutex held.  */
 325 static void curl_multi_check_completion(BDRVCURLState *s)
 326 {
 327     int msgs_in_queue;
 328
 329     /* Try to find done transfers, so we can free the easy
 330      * handle again. */
 331     for (;;) {
 332         CURLMsg *msg;
 333         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 334
 335         /* Quit when there are no more completions */
 336         if (!msg)
 337             break;
 338
 339         if (msg->msg == CURLMSG_DONE) {
 340             int i;
 341             CURLState *state = NULL;
 342             bool error = msg->data.result != CURLE_OK;
 343
 344             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 345                               (char **)&state);
 346
 347             if (error) {
 348                 static int errcount = 100;
 349
 350                 /* Don't lose the original error message from curl, since
 351                  * it contains extra data.
 352                  */
 353                 if (errcount > 0) {
 354                     error_report("curl: %s", state->errmsg);
 355                     if (--errcount == 0) {
 356                         error_report("curl: further errors suppressed");
 357                     }
 358                 }
 359             }
 360
 361             for (i = 0; i < CURL_NUM_ACB; i++) {
 362                 CURLAIOCB *acb = state->acb[i];
 363
 364                 if (acb == NULL) {
 365                     continue;
 366                 }
 367
 368                 if (!error) {
 369                     /* Assert that we have read all data */
 370                     assert(state->buf_off >= acb->end);
 371
 372                     qemu_iovec_from_buf(acb->qiov, 0,
 373                                         state->orig_buf + acb->start,
 374                                         acb->end - acb->start);
 375
 376                     if (acb->end - acb->start < acb->bytes) {
 377                         size_t offset = acb->end - acb->start;
 378                         qemu_iovec_memset(acb->qiov, offset, 0,
 379                                           acb->bytes - offset);
 380                     }
 381                 }
 382
 383                 acb->ret = error ? -EIO : 0;
 384                 state->acb[i] = NULL;
 385                 qemu_mutex_unlock(&s->mutex);
 386                 aio_co_wake(acb->co);
 387                 qemu_mutex_lock(&s->mutex);
 388             }
 389
 390             curl_clean_state(state);
 391             break;
 392         }
 393     }
 394 }
 395
 396 /* Called with s->mutex held.  */
 397 static void curl_multi_do_locked(CURLSocket *socket)
 398 {
 399     BDRVCURLState *s = socket->s;
 400     int running;
 401     int r;
 402
 403     if (!s->multi) {
 404         return;
 405     }
 406
 407     do {
 408         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
 409     } while (r == CURLM_CALL_MULTI_PERFORM);
 410 }
 411
 412 static void curl_multi_do(void *arg)
 413 {
 414     CURLSocket *socket = arg;
 415     BDRVCURLState *s = socket->s;
 416
 417     qemu_mutex_lock(&s->mutex);
 418     curl_multi_do_locked(socket);
 419     curl_multi_check_completion(s);
 420     qemu_mutex_unlock(&s->mutex);
 421 }
 422
 423 static void curl_multi_timeout_do(void *arg)
 424 {
 425     BDRVCURLState *s = (BDRVCURLState *)arg;
 426     int running;
 427
 428     if (!s->multi) {
 429         return;
 430     }
 431
 432     qemu_mutex_lock(&s->mutex);
 433     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 434
 435     curl_multi_check_completion(s);
 436     qemu_mutex_unlock(&s->mutex);
 437 }
 438
 439 /* Called with s->mutex held.  */
 440 static CURLState *curl_find_state(BDRVCURLState *s)
 441 {
 442     CURLState *state = NULL;
 443     int i;
 444
 445     for (i = 0; i < CURL_NUM_STATES; i++) {
 446         if (!s->states[i].in_use) {
 447             state = &s->states[i];
 448             state->in_use = 1;
 449             break;
 450         }
 451     }
 452     return state;
 453 }
 454
 455 static int curl_init_state(BDRVCURLState *s, CURLState *state)
 456 {
 457     if (!state->curl) {
 458         state->curl = curl_easy_init();
 459         if (!state->curl) {
 460             return -EIO;
 461         }
 462         if (curl_easy_setopt(state->curl, CURLOPT_URL, s->url) ||
 463             curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 464                              (long) s->sslverify) ||
 465             curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
 466                              s->sslverify ? 2L : 0L)) {
 467             goto err;
 468         }
 469         if (s->cookie) {
 470             if (curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie)) {
 471                 goto err;
 472             }
 473         }
 474         if (curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout) ||
 475             curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 476                              (void *)curl_read_cb) ||
 477             curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state) ||
 478             curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state) ||
 479             curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1) ||
 480             curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1) ||
 481             curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1) ||
 482             curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg) ||
 483             curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1)) {
 484             goto err;
 485         }
 486         if (s->username) {
 487             if (curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username)) {
 488                 goto err;
 489             }
 490         }
 491         if (s->password) {
 492             if (curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password)) {
 493                 goto err;
 494             }
 495         }
 496         if (s->proxyusername) {
 497             if (curl_easy_setopt(state->curl,
 498                                  CURLOPT_PROXYUSERNAME, s->proxyusername)) {
 499                 goto err;
 500             }
 501         }
 502         if (s->proxypassword) {
 503             if (curl_easy_setopt(state->curl,
 504                                  CURLOPT_PROXYPASSWORD, s->proxypassword)) {
 505                 goto err;
 506             }
 507         }
 508
 509         /* Restrict supported protocols to avoid security issues in the more
 510          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 511          * CVE-2013-0249.
 512          *
 513          * Restricting protocols is only supported from 7.19.4 upwards.
 514          */
 515 #if LIBCURL_VERSION_NUM >= 0x071304
 516         if (curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS) ||
 517             curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS)) {
 518             goto err;
 519         }
 520 #endif
 521
 522 #ifdef DEBUG_VERBOSE
 523         if (curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1)) {
 524             goto err;
 525         }
 526 #endif
 527     }
 528
 529     state->s = s;
 530
 531     return 0;
 532
 533 err:
 534     curl_easy_cleanup(state->curl);
 535     state->curl = NULL;
 536     return -EIO;
 537 }
 538
 539 /* Called with s->mutex held.  */
 540 static void curl_clean_state(CURLState *s)
 541 {
 542     int j;
 543     for (j = 0; j < CURL_NUM_ACB; j++) {
 544         assert(!s->acb[j]);
 545     }
 546
 547     if (s->s->multi)
 548         curl_multi_remove_handle(s->s->multi, s->curl);
 549
 550     s->in_use = 0;
 551
 552     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
 553 }
 554
 555 static void curl_parse_filename(const char *filename, QDict *options,
 556                                 Error **errp)
 557 {
 558     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
 559 }
 560
 561 static void curl_detach_aio_context(BlockDriverState *bs)
 562 {
 563     BDRVCURLState *s = bs->opaque;
 564     int i;
 565
 566     WITH_QEMU_LOCK_GUARD(&s->mutex) {
 567         curl_drop_all_sockets(s->sockets);
 568         for (i = 0; i < CURL_NUM_STATES; i++) {
 569             if (s->states[i].in_use) {
 570                 curl_clean_state(&s->states[i]);
 571             }
 572             if (s->states[i].curl) {
 573                 curl_easy_cleanup(s->states[i].curl);
 574                 s->states[i].curl = NULL;
 575             }
 576             g_free(s->states[i].orig_buf);
 577             s->states[i].orig_buf = NULL;
 578         }
 579         if (s->multi) {
 580             curl_multi_cleanup(s->multi);
 581             s->multi = NULL;
 582         }
 583     }
 584
 585     timer_del(&s->timer);
 586 }
 587
 588 static void curl_attach_aio_context(BlockDriverState *bs,
 589                                     AioContext *new_context)
 590 {
 591     BDRVCURLState *s = bs->opaque;
 592
 593     aio_timer_init(new_context, &s->timer,
 594                    QEMU_CLOCK_REALTIME, SCALE_NS,
 595                    curl_multi_timeout_do, s);
 596
 597     assert(!s->multi);
 598     s->multi = curl_multi_init();
 599     s->aio_context = new_context;
 600     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 601     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 602     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 603 }
 604
 605 static QemuOptsList runtime_opts = {
 606     .name = "curl",
 607     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 608     .desc = {
 609         {
 610             .name = CURL_BLOCK_OPT_URL,
 611             .type = QEMU_OPT_STRING,
 612             .help = "URL to open",
 613         },
 614         {
 615             .name = CURL_BLOCK_OPT_READAHEAD,
 616             .type = QEMU_OPT_SIZE,
 617             .help = "Readahead size",
 618         },
 619         {
 620             .name = CURL_BLOCK_OPT_SSLVERIFY,
 621             .type = QEMU_OPT_BOOL,
 622             .help = "Verify SSL certificate"
 623         },
 624         {
 625             .name = CURL_BLOCK_OPT_TIMEOUT,
 626             .type = QEMU_OPT_NUMBER,
 627             .help = "Curl timeout"
 628         },
 629         {
 630             .name = CURL_BLOCK_OPT_COOKIE,
 631             .type = QEMU_OPT_STRING,
 632             .help = "Pass the cookie or list of cookies with each request"
 633         },
 634         {
 635             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
 636             .type = QEMU_OPT_STRING,
 637             .help = "ID of secret used as cookie passed with each request"
 638         },
 639         {
 640             .name = CURL_BLOCK_OPT_USERNAME,
 641             .type = QEMU_OPT_STRING,
 642             .help = "Username for HTTP auth"
 643         },
 644         {
 645             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 646             .type = QEMU_OPT_STRING,
 647             .help = "ID of secret used as password for HTTP auth",
 648         },
 649         {
 650             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 651             .type = QEMU_OPT_STRING,
 652             .help = "Username for HTTP proxy auth"
 653         },
 654         {
 655             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 656             .type = QEMU_OPT_STRING,
 657             .help = "ID of secret used as password for HTTP proxy auth",
 658         },
 659         { /* end of list */ }
 660     },
 661 };
 662
 663
 664 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 665                      Error **errp)
 666 {
 667     BDRVCURLState *s = bs->opaque;
 668     CURLState *state = NULL;
 669     QemuOpts *opts;
 670     const char *file;
 671     const char *cookie;
 672     const char *cookie_secret;
 673     double d;
 674     const char *secretid;
 675     const char *protocol_delimiter;
 676     int ret;
 677
 678     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
 679                                     errp);
 680     if (ret < 0) {
 681         return ret;
 682     }
 683
 684     if (!libcurl_initialized) {
 685         ret = curl_global_init(CURL_GLOBAL_ALL);
 686         if (ret) {
 687             error_setg(errp, "libcurl initialization failed with %d", ret);
 688             return -EIO;
 689         }
 690         libcurl_initialized = true;
 691     }
 692
 693     qemu_mutex_init(&s->mutex);
 694     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 695     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
 696         goto out_noclean;
 697     }
 698
 699     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 700                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
 701     if ((s->readahead_size & 0x1ff) != 0) {
 702         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 703                    s->readahead_size);
 704         goto out_noclean;
 705     }
 706
 707     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 708                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
 709     if (s->timeout > CURL_TIMEOUT_MAX) {
 710         error_setg(errp, "timeout parameter is too large or negative");
 711         goto out_noclean;
 712     }
 713
 714     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
 715                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
 716
 717     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 718     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
 719
 720     if (cookie && cookie_secret) {
 721         error_setg(errp,
 722                    "curl driver cannot handle both cookie and cookie secret");
 723         goto out_noclean;
 724     }
 725
 726     if (cookie_secret) {
 727         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
 728         if (!s->cookie) {
 729             goto out_noclean;
 730         }
 731     } else {
 732         s->cookie = g_strdup(cookie);
 733     }
 734
 735     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 736     if (file == NULL) {
 737         error_setg(errp, "curl block driver requires an 'url' option");
 738         goto out_noclean;
 739     }
 740
 741     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
 742         !strstart(protocol_delimiter, "://", NULL))
 743     {
 744         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
 745                    "start with '%s://')", bs->drv->protocol_name, file,
 746                    bs->drv->protocol_name);
 747         goto out_noclean;
 748     }
 749
 750     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 751     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 752
 753     if (secretid) {
 754         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 755         if (!s->password) {
 756             goto out_noclean;
 757         }
 758     }
 759
 760     s->proxyusername = g_strdup(
 761         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 762     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 763     if (secretid) {
 764         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 765         if (!s->proxypassword) {
 766             goto out_noclean;
 767         }
 768     }
 769
 770     trace_curl_open(file);
 771     qemu_co_queue_init(&s->free_state_waitq);
 772     s->aio_context = bdrv_get_aio_context(bs);
 773     s->url = g_strdup(file);
 774     s->sockets = g_hash_table_new_full(NULL, NULL, NULL, g_free);
 775     qemu_mutex_lock(&s->mutex);
 776     state = curl_find_state(s);
 777     qemu_mutex_unlock(&s->mutex);
 778     if (!state) {
 779         goto out_noclean;
 780     }
 781
 782     // Get file size
 783
 784     if (curl_init_state(s, state) < 0) {
 785         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 786                 "curl library initialization failed.");
 787         goto out;
 788     }
 789
 790     s->accept_range = false;
 791     if (curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1) ||
 792         curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION, curl_header_cb) ||
 793         curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s)) {
 794         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 795                 "curl library initialization failed.");
 796         goto out;
 797     }
 798     if (curl_easy_perform(state->curl))
 799         goto out;
 800     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
 801         goto out;
 802     }
 803     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
 804      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
 805      * known and zero if it is really zero-length file. */
 806 #if LIBCURL_VERSION_NUM >= 0x071304
 807     if (d < 0) {
 808         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 809                 "Server didn't report file size.");
 810         goto out;
 811     }
 812 #else
 813     if (d <= 0) {
 814         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 815                 "Unknown file size or zero-length file.");
 816         goto out;
 817     }
 818 #endif
 819
 820     s->len = d;
 821
 822     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 823         || !strncasecmp(s->url, "https://", strlen("https://")))
 824         && !s->accept_range) {
 825         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 826                 "Server does not support 'range' (byte ranges).");
 827         goto out;
 828     }
 829     trace_curl_open_size(s->len);
 830
 831     qemu_mutex_lock(&s->mutex);
 832     curl_clean_state(state);
 833     qemu_mutex_unlock(&s->mutex);
 834     curl_easy_cleanup(state->curl);
 835     state->curl = NULL;
 836
 837     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 838
 839     qemu_opts_del(opts);
 840     return 0;
 841
 842 out:
 843     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 844     curl_easy_cleanup(state->curl);
 845     state->curl = NULL;
 846 out_noclean:
 847     qemu_mutex_destroy(&s->mutex);
 848     g_free(s->cookie);
 849     g_free(s->url);
 850     g_free(s->username);
 851     g_free(s->proxyusername);
 852     g_free(s->proxypassword);
 853     curl_drop_all_sockets(s->sockets);
 854     g_hash_table_destroy(s->sockets);
 855     qemu_opts_del(opts);
 856     return -EINVAL;
 857 }
 858
 859 static void coroutine_fn 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     trace_curl_setup_preadv(acb->bytes, start, state->range);
 910     if (curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range) ||
 911         curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
 912         state->acb[0] = NULL;
 913         acb->ret = -EIO;
 914
 915         curl_clean_state(state);
 916         goto out;
 917     }
 918
 919     /* Tell curl it needs to kick things off */
 920     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 921
 922 out:
 923     qemu_mutex_unlock(&s->mutex);
 924 }
 925
 926 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
 927         int64_t offset, int64_t bytes, QEMUIOVector *qiov,
 928         BdrvRequestFlags flags)
 929 {
 930     CURLAIOCB acb = {
 931         .co = qemu_coroutine_self(),
 932         .ret = -EINPROGRESS,
 933         .qiov = qiov,
 934         .offset = offset,
 935         .bytes = bytes
 936     };
 937
 938     curl_setup_preadv(bs, &acb);
 939     while (acb.ret == -EINPROGRESS) {
 940         qemu_coroutine_yield();
 941     }
 942     return acb.ret;
 943 }
 944
 945 static void curl_close(BlockDriverState *bs)
 946 {
 947     BDRVCURLState *s = bs->opaque;
 948
 949     trace_curl_close();
 950     curl_detach_aio_context(bs);
 951     qemu_mutex_destroy(&s->mutex);
 952
 953     g_hash_table_destroy(s->sockets);
 954     g_free(s->cookie);
 955     g_free(s->url);
 956     g_free(s->username);
 957     g_free(s->proxyusername);
 958     g_free(s->proxypassword);
 959 }
 960
 961 static int64_t curl_getlength(BlockDriverState *bs)
 962 {
 963     BDRVCURLState *s = bs->opaque;
 964     return s->len;
 965 }
 966
 967 static void curl_refresh_filename(BlockDriverState *bs)
 968 {
 969     BDRVCURLState *s = bs->opaque;
 970
 971     /* "readahead" and "timeout" do not change the guest-visible data,
 972      * so ignore them */
 973     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
 974         s->cookie || s->username || s->password || s->proxyusername ||
 975         s->proxypassword)
 976     {
 977         return;
 978     }
 979
 980     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
 981 }
 982
 983
 984 static const char *const curl_strong_runtime_opts[] = {
 985     CURL_BLOCK_OPT_URL,
 986     CURL_BLOCK_OPT_SSLVERIFY,
 987     CURL_BLOCK_OPT_COOKIE,
 988     CURL_BLOCK_OPT_COOKIE_SECRET,
 989     CURL_BLOCK_OPT_USERNAME,
 990     CURL_BLOCK_OPT_PASSWORD_SECRET,
 991     CURL_BLOCK_OPT_PROXY_USERNAME,
 992     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 993
 994     NULL
 995 };
 996
 997 static BlockDriver bdrv_http = {
 998     .format_name                = "http",
 999     .protocol_name              = "http",
1000
1001     .instance_size              = sizeof(BDRVCURLState),
1002     .bdrv_parse_filename        = curl_parse_filename,
1003     .bdrv_file_open             = curl_open,
1004     .bdrv_close                 = curl_close,
1005     .bdrv_getlength             = curl_getlength,
1006
1007     .bdrv_co_preadv             = curl_co_preadv,
1008
1009     .bdrv_detach_aio_context    = curl_detach_aio_context,
1010     .bdrv_attach_aio_context    = curl_attach_aio_context,
1011
1012     .bdrv_refresh_filename      = curl_refresh_filename,
1013     .strong_runtime_opts        = curl_strong_runtime_opts,
1014 };
1015
1016 static BlockDriver bdrv_https = {
1017     .format_name                = "https",
1018     .protocol_name              = "https",
1019
1020     .instance_size              = sizeof(BDRVCURLState),
1021     .bdrv_parse_filename        = curl_parse_filename,
1022     .bdrv_file_open             = curl_open,
1023     .bdrv_close                 = curl_close,
1024     .bdrv_getlength             = curl_getlength,
1025
1026     .bdrv_co_preadv             = curl_co_preadv,
1027
1028     .bdrv_detach_aio_context    = curl_detach_aio_context,
1029     .bdrv_attach_aio_context    = curl_attach_aio_context,
1030
1031     .bdrv_refresh_filename      = curl_refresh_filename,
1032     .strong_runtime_opts        = curl_strong_runtime_opts,
1033 };
1034
1035 static BlockDriver bdrv_ftp = {
1036     .format_name                = "ftp",
1037     .protocol_name              = "ftp",
1038
1039     .instance_size              = sizeof(BDRVCURLState),
1040     .bdrv_parse_filename        = curl_parse_filename,
1041     .bdrv_file_open             = curl_open,
1042     .bdrv_close                 = curl_close,
1043     .bdrv_getlength             = curl_getlength,
1044
1045     .bdrv_co_preadv             = curl_co_preadv,
1046
1047     .bdrv_detach_aio_context    = curl_detach_aio_context,
1048     .bdrv_attach_aio_context    = curl_attach_aio_context,
1049
1050     .bdrv_refresh_filename      = curl_refresh_filename,
1051     .strong_runtime_opts        = curl_strong_runtime_opts,
1052 };
1053
1054 static BlockDriver bdrv_ftps = {
1055     .format_name                = "ftps",
1056     .protocol_name              = "ftps",
1057
1058     .instance_size              = sizeof(BDRVCURLState),
1059     .bdrv_parse_filename        = curl_parse_filename,
1060     .bdrv_file_open             = curl_open,
1061     .bdrv_close                 = curl_close,
1062     .bdrv_getlength             = curl_getlength,
1063
1064     .bdrv_co_preadv             = curl_co_preadv,
1065
1066     .bdrv_detach_aio_context    = curl_detach_aio_context,
1067     .bdrv_attach_aio_context    = curl_attach_aio_context,
1068
1069     .bdrv_refresh_filename      = curl_refresh_filename,
1070     .strong_runtime_opts        = curl_strong_runtime_opts,
1071 };
1072
1073 static void curl_block_init(void)
1074 {
1075     bdrv_register(&bdrv_http);
1076     bdrv_register(&bdrv_https);
1077     bdrv_register(&bdrv_ftp);
1078     bdrv_register(&bdrv_ftps);
1079 }
1080
1081 block_init(curl_block_init);