xref: /openbmc/qemu/block/curl.c (revision 02f5360d80a7a45190e31b8255b60edaf101211c)
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);
1108