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,
 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,
 184                                curl_multi_do, NULL, NULL, NULL, socket);
 185             break;
 186         case CURL_POLL_OUT:
 187             aio_set_fd_handler(s->aio_context, fd,
 188                                NULL, curl_multi_do, NULL, NULL, socket);
 189             break;
 190         case CURL_POLL_INOUT:
 191             aio_set_fd_handler(s->aio_context, fd,
 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,
 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 *p = ptr;
 214     const char *end = p + realsize;
 215     const char *t = "accept-ranges : bytes "; /* A lowercase template */
 216
 217     /* check if header matches the "t" template */
 218     for (;;) {
 219         if (*t == ' ') { /* space in t matches any amount of isspace in p */
 220             if (p < end && g_ascii_isspace(*p)) {
 221                 ++p;
 222             } else {
 223                 ++t;
 224             }
 225         } else if (*t && p < end && *t == g_ascii_tolower(*p)) {
 226             ++p, ++t;
 227         } else {
 228             break;
 229         }
 230     }
 231
 232     if (!*t && p == end) { /* if we managed to reach ends of both strings */
 233         s->accept_range = true;
 234     }
 235
 236     return realsize;
 237 }
 238
 239 /* Called from curl_multi_do_locked, with s->mutex held.  */
 240 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 241 {
 242     CURLState *s = ((CURLState*)opaque);
 243     size_t realsize = size * nmemb;
 244
 245     trace_curl_read_cb(realsize);
 246
 247     if (!s || !s->orig_buf) {
 248         goto read_end;
 249     }
 250
 251     if (s->buf_off >= s->buf_len) {
 252         /* buffer full, read nothing */
 253         goto read_end;
 254     }
 255     realsize = MIN(realsize, s->buf_len - s->buf_off);
 256     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 257     s->buf_off += realsize;
 258
 259 read_end:
 260     /* curl will error out if we do not return this value */
 261     return size * nmemb;
 262 }
 263
 264 /* Called with s->mutex held.  */
 265 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
 266                           CURLAIOCB *acb)
 267 {
 268     int i;
 269     uint64_t end = start + len;
 270     uint64_t clamped_end = MIN(end, s->len);
 271     uint64_t clamped_len = clamped_end - start;
 272
 273     for (i=0; i<CURL_NUM_STATES; i++) {
 274         CURLState *state = &s->states[i];
 275         uint64_t buf_end = (state->buf_start + state->buf_off);
 276         uint64_t buf_fend = (state->buf_start + state->buf_len);
 277
 278         if (!state->orig_buf)
 279             continue;
 280         if (!state->buf_off)
 281             continue;
 282
 283         // Does the existing buffer cover our section?
 284         if ((start >= state->buf_start) &&
 285             (start <= buf_end) &&
 286             (clamped_end >= state->buf_start) &&
 287             (clamped_end <= buf_end))
 288         {
 289             char *buf = state->orig_buf + (start - state->buf_start);
 290
 291             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
 292             if (clamped_len < len) {
 293                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
 294             }
 295             acb->ret = 0;
 296             return true;
 297         }
 298
 299         // Wait for unfinished chunks
 300         if (state->in_use &&
 301             (start >= state->buf_start) &&
 302             (start <= buf_fend) &&
 303             (clamped_end >= state->buf_start) &&
 304             (clamped_end <= buf_fend))
 305         {
 306             int j;
 307
 308             acb->start = start - state->buf_start;
 309             acb->end = acb->start + clamped_len;
 310
 311             for (j=0; j<CURL_NUM_ACB; j++) {
 312                 if (!state->acb[j]) {
 313                     state->acb[j] = acb;
 314                     return true;
 315                 }
 316             }
 317         }
 318     }
 319
 320     return false;
 321 }
 322
 323 /* Called with s->mutex held.  */
 324 static void curl_multi_check_completion(BDRVCURLState *s)
 325 {
 326     int msgs_in_queue;
 327
 328     /* Try to find done transfers, so we can free the easy
 329      * handle again. */
 330     for (;;) {
 331         CURLMsg *msg;
 332         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 333
 334         /* Quit when there are no more completions */
 335         if (!msg)
 336             break;
 337
 338         if (msg->msg == CURLMSG_DONE) {
 339             int i;
 340             CURLState *state = NULL;
 341             bool error = msg->data.result != CURLE_OK;
 342
 343             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 344                               (char **)&state);
 345
 346             if (error) {
 347                 static int errcount = 100;
 348
 349                 /* Don't lose the original error message from curl, since
 350                  * it contains extra data.
 351                  */
 352                 if (errcount > 0) {
 353                     error_report("curl: %s", state->errmsg);
 354                     if (--errcount == 0) {
 355                         error_report("curl: further errors suppressed");
 356                     }
 357                 }
 358             }
 359
 360             for (i = 0; i < CURL_NUM_ACB; i++) {
 361                 CURLAIOCB *acb = state->acb[i];
 362
 363                 if (acb == NULL) {
 364                     continue;
 365                 }
 366
 367                 if (!error) {
 368                     /* Assert that we have read all data */
 369                     assert(state->buf_off >= acb->end);
 370
 371                     qemu_iovec_from_buf(acb->qiov, 0,
 372                                         state->orig_buf + acb->start,
 373                                         acb->end - acb->start);
 374
 375                     if (acb->end - acb->start < acb->bytes) {
 376                         size_t offset = acb->end - acb->start;
 377                         qemu_iovec_memset(acb->qiov, offset, 0,
 378                                           acb->bytes - offset);
 379                     }
 380                 }
 381
 382                 acb->ret = error ? -EIO : 0;
 383                 state->acb[i] = NULL;
 384                 qemu_mutex_unlock(&s->mutex);
 385                 aio_co_wake(acb->co);
 386                 qemu_mutex_lock(&s->mutex);
 387             }
 388
 389             curl_clean_state(state);
 390             break;
 391         }
 392     }
 393 }
 394
 395 /* Called with s->mutex held.  */
 396 static void curl_multi_do_locked(CURLSocket *socket)
 397 {
 398     BDRVCURLState *s = socket->s;
 399     int running;
 400     int r;
 401
 402     if (!s->multi) {
 403         return;
 404     }
 405
 406     do {
 407         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
 408     } while (r == CURLM_CALL_MULTI_PERFORM);
 409 }
 410
 411 static void curl_multi_do(void *arg)
 412 {
 413     CURLSocket *socket = arg;
 414     BDRVCURLState *s = socket->s;
 415
 416     qemu_mutex_lock(&s->mutex);
 417     curl_multi_do_locked(socket);
 418     curl_multi_check_completion(s);
 419     qemu_mutex_unlock(&s->mutex);
 420 }
 421
 422 static void curl_multi_timeout_do(void *arg)
 423 {
 424     BDRVCURLState *s = (BDRVCURLState *)arg;
 425     int running;
 426
 427     if (!s->multi) {
 428         return;
 429     }
 430
 431     qemu_mutex_lock(&s->mutex);
 432     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 433
 434     curl_multi_check_completion(s);
 435     qemu_mutex_unlock(&s->mutex);
 436 }
 437
 438 /* Called with s->mutex held.  */
 439 static CURLState *curl_find_state(BDRVCURLState *s)
 440 {
 441     CURLState *state = NULL;
 442     int i;
 443
 444     for (i = 0; i < CURL_NUM_STATES; i++) {
 445         if (!s->states[i].in_use) {
 446             state = &s->states[i];
 447             state->in_use = 1;
 448             break;
 449         }
 450     }
 451     return state;
 452 }
 453
 454 static int curl_init_state(BDRVCURLState *s, CURLState *state)
 455 {
 456     if (!state->curl) {
 457         state->curl = curl_easy_init();
 458         if (!state->curl) {
 459             return -EIO;
 460         }
 461         if (curl_easy_setopt(state->curl, CURLOPT_URL, s->url) ||
 462             curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 463                              (long) s->sslverify) ||
 464             curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
 465                              s->sslverify ? 2L : 0L)) {
 466             goto err;
 467         }
 468         if (s->cookie) {
 469             if (curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie)) {
 470                 goto err;
 471             }
 472         }
 473         if (curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout) ||
 474             curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 475                              (void *)curl_read_cb) ||
 476             curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state) ||
 477             curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state) ||
 478             curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1) ||
 479             curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1) ||
 480             curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1) ||
 481             curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg) ||
 482             curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1)) {
 483             goto err;
 484         }
 485         if (s->username) {
 486             if (curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username)) {
 487                 goto err;
 488             }
 489         }
 490         if (s->password) {
 491             if (curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password)) {
 492                 goto err;
 493             }
 494         }
 495         if (s->proxyusername) {
 496             if (curl_easy_setopt(state->curl,
 497                                  CURLOPT_PROXYUSERNAME, s->proxyusername)) {
 498                 goto err;
 499             }
 500         }
 501         if (s->proxypassword) {
 502             if (curl_easy_setopt(state->curl,
 503                                  CURLOPT_PROXYPASSWORD, s->proxypassword)) {
 504                 goto err;
 505             }
 506         }
 507
 508         /* Restrict supported protocols to avoid security issues in the more
 509          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 510          * CVE-2013-0249.
 511          *
 512          * Restricting protocols is only supported from 7.19.4 upwards. Note:
 513          * version 7.85.0 deprecates CURLOPT_*PROTOCOLS in favour of a string
 514          * based CURLOPT_*PROTOCOLS_STR API.
 515          */
 516 #if LIBCURL_VERSION_NUM >= 0x075500
 517         if (curl_easy_setopt(state->curl,
 518                              CURLOPT_PROTOCOLS_STR, PROTOCOLS) ||
 519             curl_easy_setopt(state->curl,
 520                              CURLOPT_REDIR_PROTOCOLS_STR, PROTOCOLS)) {
 521             goto err;
 522         }
 523 #elif LIBCURL_VERSION_NUM >= 0x071304
 524         if (curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS) ||
 525             curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS)) {
 526             goto err;
 527         }
 528 #endif
 529
 530 #ifdef DEBUG_VERBOSE
 531         if (curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1)) {
 532             goto err;
 533         }
 534 #endif
 535     }
 536
 537     state->s = s;
 538
 539     return 0;
 540
 541 err:
 542     curl_easy_cleanup(state->curl);
 543     state->curl = NULL;
 544     return -EIO;
 545 }
 546
 547 /* Called with s->mutex held.  */
 548 static void curl_clean_state(CURLState *s)
 549 {
 550     int j;
 551     for (j = 0; j < CURL_NUM_ACB; j++) {
 552         assert(!s->acb[j]);
 553     }
 554
 555     if (s->s->multi)
 556         curl_multi_remove_handle(s->s->multi, s->curl);
 557
 558     s->in_use = 0;
 559
 560     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
 561 }
 562
 563 static void curl_parse_filename(const char *filename, QDict *options,
 564                                 Error **errp)
 565 {
 566     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
 567 }
 568
 569 static void curl_detach_aio_context(BlockDriverState *bs)
 570 {
 571     BDRVCURLState *s = bs->opaque;
 572     int i;
 573
 574     WITH_QEMU_LOCK_GUARD(&s->mutex) {
 575         curl_drop_all_sockets(s->sockets);
 576         for (i = 0; i < CURL_NUM_STATES; i++) {
 577             if (s->states[i].in_use) {
 578                 curl_clean_state(&s->states[i]);
 579             }
 580             if (s->states[i].curl) {
 581                 curl_easy_cleanup(s->states[i].curl);
 582                 s->states[i].curl = NULL;
 583             }
 584             g_free(s->states[i].orig_buf);
 585             s->states[i].orig_buf = NULL;
 586         }
 587         if (s->multi) {
 588             curl_multi_cleanup(s->multi);
 589             s->multi = NULL;
 590         }
 591     }
 592
 593     timer_del(&s->timer);
 594 }
 595
 596 static void curl_attach_aio_context(BlockDriverState *bs,
 597                                     AioContext *new_context)
 598 {
 599     BDRVCURLState *s = bs->opaque;
 600
 601     aio_timer_init(new_context, &s->timer,
 602                    QEMU_CLOCK_REALTIME, SCALE_NS,
 603                    curl_multi_timeout_do, s);
 604
 605     assert(!s->multi);
 606     s->multi = curl_multi_init();
 607     s->aio_context = new_context;
 608     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 609     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 610     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 611 }
 612
 613 static QemuOptsList runtime_opts = {
 614     .name = "curl",
 615     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 616     .desc = {
 617         {
 618             .name = CURL_BLOCK_OPT_URL,
 619             .type = QEMU_OPT_STRING,
 620             .help = "URL to open",
 621         },
 622         {
 623             .name = CURL_BLOCK_OPT_READAHEAD,
 624             .type = QEMU_OPT_SIZE,
 625             .help = "Readahead size",
 626         },
 627         {
 628             .name = CURL_BLOCK_OPT_SSLVERIFY,
 629             .type = QEMU_OPT_BOOL,
 630             .help = "Verify SSL certificate"
 631         },
 632         {
 633             .name = CURL_BLOCK_OPT_TIMEOUT,
 634             .type = QEMU_OPT_NUMBER,
 635             .help = "Curl timeout"
 636         },
 637         {
 638             .name = CURL_BLOCK_OPT_COOKIE,
 639             .type = QEMU_OPT_STRING,
 640             .help = "Pass the cookie or list of cookies with each request"
 641         },
 642         {
 643             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
 644             .type = QEMU_OPT_STRING,
 645             .help = "ID of secret used as cookie passed with each request"
 646         },
 647         {
 648             .name = CURL_BLOCK_OPT_USERNAME,
 649             .type = QEMU_OPT_STRING,
 650             .help = "Username for HTTP auth"
 651         },
 652         {
 653             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 654             .type = QEMU_OPT_STRING,
 655             .help = "ID of secret used as password for HTTP auth",
 656         },
 657         {
 658             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 659             .type = QEMU_OPT_STRING,
 660             .help = "Username for HTTP proxy auth"
 661         },
 662         {
 663             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 664             .type = QEMU_OPT_STRING,
 665             .help = "ID of secret used as password for HTTP proxy auth",
 666         },
 667         { /* end of list */ }
 668     },
 669 };
 670
 671
 672 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 673                      Error **errp)
 674 {
 675     BDRVCURLState *s = bs->opaque;
 676     CURLState *state = NULL;
 677     QemuOpts *opts;
 678     const char *file;
 679     const char *cookie;
 680     const char *cookie_secret;
 681     /* CURL >= 7.55.0 uses curl_off_t for content length instead of a double */
 682 #if LIBCURL_VERSION_NUM >= 0x073700
 683     curl_off_t cl;
 684 #else
 685     double cl;
 686 #endif
 687     const char *secretid;
 688     const char *protocol_delimiter;
 689     int ret;
 690
 691     bdrv_graph_rdlock_main_loop();
 692     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
 693                                     errp);
 694     bdrv_graph_rdunlock_main_loop();
 695     if (ret < 0) {
 696         return ret;
 697     }
 698
 699     if (!libcurl_initialized) {
 700         ret = curl_global_init(CURL_GLOBAL_ALL);
 701         if (ret) {
 702             error_setg(errp, "libcurl initialization failed with %d", ret);
 703             return -EIO;
 704         }
 705         libcurl_initialized = true;
 706     }
 707
 708     qemu_mutex_init(&s->mutex);
 709     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 710     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
 711         goto out_noclean;
 712     }
 713
 714     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 715                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
 716     if ((s->readahead_size & 0x1ff) != 0) {
 717         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 718                    s->readahead_size);
 719         goto out_noclean;
 720     }
 721
 722     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 723                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
 724     if (s->timeout > CURL_TIMEOUT_MAX) {
 725         error_setg(errp, "timeout parameter is too large or negative");
 726         goto out_noclean;
 727     }
 728
 729     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
 730                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
 731
 732     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 733     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
 734
 735     if (cookie && cookie_secret) {
 736         error_setg(errp,
 737                    "curl driver cannot handle both cookie and cookie secret");
 738         goto out_noclean;
 739     }
 740
 741     if (cookie_secret) {
 742         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
 743         if (!s->cookie) {
 744             goto out_noclean;
 745         }
 746     } else {
 747         s->cookie = g_strdup(cookie);
 748     }
 749
 750     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 751     if (file == NULL) {
 752         error_setg(errp, "curl block driver requires an 'url' option");
 753         goto out_noclean;
 754     }
 755
 756     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
 757         !strstart(protocol_delimiter, "://", NULL))
 758     {
 759         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
 760                    "start with '%s://')", bs->drv->protocol_name, file,
 761                    bs->drv->protocol_name);
 762         goto out_noclean;
 763     }
 764
 765     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 766     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 767
 768     if (secretid) {
 769         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 770         if (!s->password) {
 771             goto out_noclean;
 772         }
 773     }
 774
 775     s->proxyusername = g_strdup(
 776         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 777     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 778     if (secretid) {
 779         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 780         if (!s->proxypassword) {
 781             goto out_noclean;
 782         }
 783     }
 784
 785     trace_curl_open(file);
 786     qemu_co_queue_init(&s->free_state_waitq);
 787     s->aio_context = bdrv_get_aio_context(bs);
 788     s->url = g_strdup(file);
 789     s->sockets = g_hash_table_new_full(NULL, NULL, NULL, g_free);
 790     qemu_mutex_lock(&s->mutex);
 791     state = curl_find_state(s);
 792     qemu_mutex_unlock(&s->mutex);
 793     if (!state) {
 794         goto out_noclean;
 795     }
 796
 797     // Get file size
 798
 799     if (curl_init_state(s, state) < 0) {
 800         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 801                 "curl library initialization failed.");
 802         goto out;
 803     }
 804
 805     s->accept_range = false;
 806     if (curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1) ||
 807         curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION, curl_header_cb) ||
 808         curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s)) {
 809         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 810                 "curl library initialization failed.");
 811         goto out;
 812     }
 813     if (curl_easy_perform(state->curl))
 814         goto out;
 815     /* CURL 7.55.0 deprecates CURLINFO_CONTENT_LENGTH_DOWNLOAD in favour of
 816      * the *_T version which returns a more sensible type for content length.
 817      */
 818 #if LIBCURL_VERSION_NUM >= 0x073700
 819     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD_T, &cl)) {
 820         goto out;
 821     }
 822 #else
 823     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &cl)) {
 824         goto out;
 825     }
 826 #endif
 827     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
 828      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
 829      * known and zero if it is really zero-length file. */
 830 #if LIBCURL_VERSION_NUM >= 0x071304
 831     if (cl < 0) {
 832         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 833                 "Server didn't report file size.");
 834         goto out;
 835     }
 836 #else
 837     if (cl <= 0) {
 838         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 839                 "Unknown file size or zero-length file.");
 840         goto out;
 841     }
 842 #endif
 843
 844     s->len = cl;
 845
 846     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 847         || !strncasecmp(s->url, "https://", strlen("https://")))
 848         && !s->accept_range) {
 849         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 850                 "Server does not support 'range' (byte ranges).");
 851         goto out;
 852     }
 853     trace_curl_open_size(s->len);
 854
 855     qemu_mutex_lock(&s->mutex);
 856     curl_clean_state(state);
 857     qemu_mutex_unlock(&s->mutex);
 858     curl_easy_cleanup(state->curl);
 859     state->curl = NULL;
 860
 861     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 862
 863     qemu_opts_del(opts);
 864     return 0;
 865
 866 out:
 867     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 868     curl_easy_cleanup(state->curl);
 869     state->curl = NULL;
 870 out_noclean:
 871     qemu_mutex_destroy(&s->mutex);
 872     g_free(s->cookie);
 873     g_free(s->url);
 874     g_free(s->username);
 875     g_free(s->proxyusername);
 876     g_free(s->proxypassword);
 877     if (s->sockets) {
 878         curl_drop_all_sockets(s->sockets);
 879         g_hash_table_destroy(s->sockets);
 880     }
 881     qemu_opts_del(opts);
 882     return -EINVAL;
 883 }
 884
 885 static void coroutine_fn curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
 886 {
 887     CURLState *state;
 888     int running;
 889
 890     BDRVCURLState *s = bs->opaque;
 891
 892     uint64_t start = acb->offset;
 893     uint64_t end;
 894
 895     qemu_mutex_lock(&s->mutex);
 896
 897     // In case we have the requested data already (e.g. read-ahead),
 898     // we can just call the callback and be done.
 899     if (curl_find_buf(s, start, acb->bytes, acb)) {
 900         goto out;
 901     }
 902
 903     // No cache found, so let's start a new request
 904     for (;;) {
 905         state = curl_find_state(s);
 906         if (state) {
 907             break;
 908         }
 909         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
 910     }
 911
 912     if (curl_init_state(s, state) < 0) {
 913         curl_clean_state(state);
 914         acb->ret = -EIO;
 915         goto out;
 916     }
 917
 918     acb->start = 0;
 919     acb->end = MIN(acb->bytes, s->len - start);
 920
 921     state->buf_off = 0;
 922     g_free(state->orig_buf);
 923     state->buf_start = start;
 924     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
 925     end = start + state->buf_len - 1;
 926     state->orig_buf = g_try_malloc(state->buf_len);
 927     if (state->buf_len && state->orig_buf == NULL) {
 928         curl_clean_state(state);
 929         acb->ret = -ENOMEM;
 930         goto out;
 931     }
 932     state->acb[0] = acb;
 933
 934     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
 935     trace_curl_setup_preadv(acb->bytes, start, state->range);
 936     if (curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range) ||
 937         curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
 938         state->acb[0] = NULL;
 939         acb->ret = -EIO;
 940
 941         curl_clean_state(state);
 942         goto out;
 943     }
 944
 945     /* Tell curl it needs to kick things off */
 946     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 947
 948 out:
 949     qemu_mutex_unlock(&s->mutex);
 950 }
 951
 952 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
 953         int64_t offset, int64_t bytes, QEMUIOVector *qiov,
 954         BdrvRequestFlags flags)
 955 {
 956     CURLAIOCB acb = {
 957         .co = qemu_coroutine_self(),
 958         .ret = -EINPROGRESS,
 959         .qiov = qiov,
 960         .offset = offset,
 961         .bytes = bytes
 962     };
 963
 964     curl_setup_preadv(bs, &acb);
 965     while (acb.ret == -EINPROGRESS) {
 966         qemu_coroutine_yield();
 967     }
 968     return acb.ret;
 969 }
 970
 971 static void curl_close(BlockDriverState *bs)
 972 {
 973     BDRVCURLState *s = bs->opaque;
 974
 975     trace_curl_close();
 976     curl_detach_aio_context(bs);
 977     qemu_mutex_destroy(&s->mutex);
 978
 979     g_hash_table_destroy(s->sockets);
 980     g_free(s->cookie);
 981     g_free(s->url);
 982     g_free(s->username);
 983     g_free(s->proxyusername);
 984     g_free(s->proxypassword);
 985 }
 986
 987 static int64_t coroutine_fn curl_co_getlength(BlockDriverState *bs)
 988 {
 989     BDRVCURLState *s = bs->opaque;
 990     return s->len;
 991 }
 992
 993 static void curl_refresh_filename(BlockDriverState *bs)
 994 {
 995     BDRVCURLState *s = bs->opaque;
 996
 997     /* "readahead" and "timeout" do not change the guest-visible data,
 998      * so ignore them */
 999     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
1000         s->cookie || s->username || s->password || s->proxyusername ||
1001         s->proxypassword)
1002     {
1003         return;
1004     }
1005
1006     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
1007 }
1008
1009
1010 static const char *const curl_strong_runtime_opts[] = {
1011     CURL_BLOCK_OPT_URL,
1012     CURL_BLOCK_OPT_SSLVERIFY,
1013     CURL_BLOCK_OPT_COOKIE,
1014     CURL_BLOCK_OPT_COOKIE_SECRET,
1015     CURL_BLOCK_OPT_USERNAME,
1016     CURL_BLOCK_OPT_PASSWORD_SECRET,
1017     CURL_BLOCK_OPT_PROXY_USERNAME,
1018     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
1019
1020     NULL
1021 };
1022
1023 static BlockDriver bdrv_http = {
1024     .format_name                = "http",
1025     .protocol_name              = "http",
1026
1027     .instance_size              = sizeof(BDRVCURLState),
1028     .bdrv_parse_filename        = curl_parse_filename,
1029     .bdrv_open                  = curl_open,
1030     .bdrv_close                 = curl_close,
1031     .bdrv_co_getlength          = curl_co_getlength,
1032
1033     .bdrv_co_preadv             = curl_co_preadv,
1034
1035     .bdrv_detach_aio_context    = curl_detach_aio_context,
1036     .bdrv_attach_aio_context    = curl_attach_aio_context,
1037
1038     .bdrv_refresh_filename      = curl_refresh_filename,
1039     .strong_runtime_opts        = curl_strong_runtime_opts,
1040 };
1041
1042 static BlockDriver bdrv_https = {
1043     .format_name                = "https",
1044     .protocol_name              = "https",
1045
1046     .instance_size              = sizeof(BDRVCURLState),
1047     .bdrv_parse_filename        = curl_parse_filename,
1048     .bdrv_open                  = curl_open,
1049     .bdrv_close                 = curl_close,
1050     .bdrv_co_getlength          = curl_co_getlength,
1051
1052     .bdrv_co_preadv             = curl_co_preadv,
1053
1054     .bdrv_detach_aio_context    = curl_detach_aio_context,
1055     .bdrv_attach_aio_context    = curl_attach_aio_context,
1056
1057     .bdrv_refresh_filename      = curl_refresh_filename,
1058     .strong_runtime_opts        = curl_strong_runtime_opts,
1059 };
1060
1061 static BlockDriver bdrv_ftp = {
1062     .format_name                = "ftp",
1063     .protocol_name              = "ftp",
1064
1065     .instance_size              = sizeof(BDRVCURLState),
1066     .bdrv_parse_filename        = curl_parse_filename,
1067     .bdrv_open                  = curl_open,
1068     .bdrv_close                 = curl_close,
1069     .bdrv_co_getlength          = curl_co_getlength,
1070
1071     .bdrv_co_preadv             = curl_co_preadv,
1072
1073     .bdrv_detach_aio_context    = curl_detach_aio_context,
1074     .bdrv_attach_aio_context    = curl_attach_aio_context,
1075
1076     .bdrv_refresh_filename      = curl_refresh_filename,
1077     .strong_runtime_opts        = curl_strong_runtime_opts,
1078 };
1079
1080 static BlockDriver bdrv_ftps = {
1081     .format_name                = "ftps",
1082     .protocol_name              = "ftps",
1083
1084     .instance_size              = sizeof(BDRVCURLState),
1085     .bdrv_parse_filename        = curl_parse_filename,
1086     .bdrv_open                  = curl_open,
1087     .bdrv_close                 = curl_close,
1088     .bdrv_co_getlength          = curl_co_getlength,
1089
1090     .bdrv_co_preadv             = curl_co_preadv,
1091
1092     .bdrv_detach_aio_context    = curl_detach_aio_context,
1093     .bdrv_attach_aio_context    = curl_attach_aio_context,
1094
1095     .bdrv_refresh_filename      = curl_refresh_filename,
1096     .strong_runtime_opts        = curl_strong_runtime_opts,
1097 };
1098
1099 static void curl_block_init(void)
1100 {
1101     bdrv_register(&bdrv_http);
1102     bdrv_register(&bdrv_https);
1103     bdrv_register(&bdrv_ftp);
1104     bdrv_register(&bdrv_ftps);
1105 }
1106
1107 block_init(curl_block_init);