xref: /openbmc/qemu/block/curl.c (revision f363d039)
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_int.h"
31 #include "qapi/qmp/qdict.h"
32 #include "qapi/qmp/qstring.h"
33 #include "crypto/secret.h"
34 #include <curl/curl.h>
35 #include "qemu/cutils.h"
36 #include "trace.h"
37 
38 // #define DEBUG_VERBOSE
39 
40 #if LIBCURL_VERSION_NUM >= 0x071000
41 /* The multi interface timer callback was introduced in 7.16.0 */
42 #define NEED_CURL_TIMER_CALLBACK
43 #define HAVE_SOCKET_ACTION
44 #endif
45 
46 #ifndef HAVE_SOCKET_ACTION
47 /* If curl_multi_socket_action isn't available, define it statically here in
48  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
49  * less efficient but still safe. */
50 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
51                                             curl_socket_t sockfd,
52                                             int ev_bitmask,
53                                             int *running_handles)
54 {
55     return curl_multi_socket(multi_handle, sockfd, running_handles);
56 }
57 #define curl_multi_socket_action __curl_multi_socket_action
58 #endif
59 
60 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
61                    CURLPROTO_FTP | CURLPROTO_FTPS)
62 
63 #define CURL_NUM_STATES 8
64 #define CURL_NUM_ACB    8
65 #define CURL_TIMEOUT_MAX 10000
66 
67 #define CURL_BLOCK_OPT_URL       "url"
68 #define CURL_BLOCK_OPT_READAHEAD "readahead"
69 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
70 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
71 #define CURL_BLOCK_OPT_COOKIE    "cookie"
72 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
73 #define CURL_BLOCK_OPT_USERNAME "username"
74 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
75 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
76 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
77 
78 #define CURL_BLOCK_OPT_READAHEAD_DEFAULT (256 * 1024)
79 #define CURL_BLOCK_OPT_SSLVERIFY_DEFAULT true
80 #define CURL_BLOCK_OPT_TIMEOUT_DEFAULT 5
81 
82 struct BDRVCURLState;
83 struct CURLState;
84 
85 static bool libcurl_initialized;
86 
87 typedef struct CURLAIOCB {
88     Coroutine *co;
89     QEMUIOVector *qiov;
90 
91     uint64_t offset;
92     uint64_t bytes;
93     int ret;
94 
95     size_t start;
96     size_t end;
97 } CURLAIOCB;
98 
99 typedef struct CURLSocket {
100     int fd;
101     struct CURLState *state;
102     QLIST_ENTRY(CURLSocket) next;
103 } CURLSocket;
104 
105 typedef struct CURLState
106 {
107     struct BDRVCURLState *s;
108     CURLAIOCB *acb[CURL_NUM_ACB];
109     CURL *curl;
110     QLIST_HEAD(, CURLSocket) sockets;
111     char *orig_buf;
112     uint64_t buf_start;
113     size_t buf_off;
114     size_t buf_len;
115     char range[128];
116     char errmsg[CURL_ERROR_SIZE];
117     char in_use;
118 } CURLState;
119 
120 typedef struct BDRVCURLState {
121     CURLM *multi;
122     QEMUTimer timer;
123     uint64_t len;
124     CURLState states[CURL_NUM_STATES];
125     char *url;
126     size_t readahead_size;
127     bool sslverify;
128     uint64_t timeout;
129     char *cookie;
130     bool accept_range;
131     AioContext *aio_context;
132     QemuMutex mutex;
133     CoQueue free_state_waitq;
134     char *username;
135     char *password;
136     char *proxyusername;
137     char *proxypassword;
138 } BDRVCURLState;
139 
140 static void curl_clean_state(CURLState *s);
141 static void curl_multi_do(void *arg);
142 
143 #ifdef NEED_CURL_TIMER_CALLBACK
144 /* Called from curl_multi_do_locked, with s->mutex held.  */
145 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
146 {
147     BDRVCURLState *s = opaque;
148 
149     trace_curl_timer_cb(timeout_ms);
150     if (timeout_ms == -1) {
151         timer_del(&s->timer);
152     } else {
153         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
154         timer_mod(&s->timer,
155                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
156     }
157     return 0;
158 }
159 #endif
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     QLIST_FOREACH(socket, &state->sockets, next) {
173         if (socket->fd == fd) {
174             break;
175         }
176     }
177     if (!socket) {
178         socket = g_new0(CURLSocket, 1);
179         socket->fd = fd;
180         socket->state = state;
181         QLIST_INSERT_HEAD(&state->sockets, socket, next);
182     }
183 
184     trace_curl_sock_cb(action, (int)fd);
185     switch (action) {
186         case CURL_POLL_IN:
187             aio_set_fd_handler(s->aio_context, fd, false,
188                                curl_multi_do, NULL, NULL, socket);
189             break;
190         case CURL_POLL_OUT:
191             aio_set_fd_handler(s->aio_context, fd, false,
192                                NULL, curl_multi_do, NULL, socket);
193             break;
194         case CURL_POLL_INOUT:
195             aio_set_fd_handler(s->aio_context, fd, false,
196                                curl_multi_do, curl_multi_do, NULL, socket);
197             break;
198         case CURL_POLL_REMOVE:
199             aio_set_fd_handler(s->aio_context, fd, false,
200                                NULL, NULL, NULL, NULL);
201             break;
202     }
203 
204     if (action == CURL_POLL_REMOVE) {
205         QLIST_REMOVE(socket, next);
206         g_free(socket);
207     }
208 
209     return 0;
210 }
211 
212 /* Called from curl_multi_do_locked, with s->mutex held.  */
213 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
214 {
215     BDRVCURLState *s = opaque;
216     size_t realsize = size * nmemb;
217     const char *accept_line = "Accept-Ranges: bytes";
218 
219     if (realsize >= strlen(accept_line)
220         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
221         s->accept_range = true;
222     }
223 
224     return realsize;
225 }
226 
227 /* Called from curl_multi_do_locked, with s->mutex held.  */
228 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
229 {
230     CURLState *s = ((CURLState*)opaque);
231     size_t realsize = size * nmemb;
232 
233     trace_curl_read_cb(realsize);
234 
235     if (!s || !s->orig_buf) {
236         goto read_end;
237     }
238 
239     if (s->buf_off >= s->buf_len) {
240         /* buffer full, read nothing */
241         goto read_end;
242     }
243     realsize = MIN(realsize, s->buf_len - s->buf_off);
244     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
245     s->buf_off += realsize;
246 
247 read_end:
248     /* curl will error out if we do not return this value */
249     return size * nmemb;
250 }
251 
252 /* Called with s->mutex held.  */
253 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
254                           CURLAIOCB *acb)
255 {
256     int i;
257     uint64_t end = start + len;
258     uint64_t clamped_end = MIN(end, s->len);
259     uint64_t clamped_len = clamped_end - start;
260 
261     for (i=0; i<CURL_NUM_STATES; i++) {
262         CURLState *state = &s->states[i];
263         uint64_t buf_end = (state->buf_start + state->buf_off);
264         uint64_t buf_fend = (state->buf_start + state->buf_len);
265 
266         if (!state->orig_buf)
267             continue;
268         if (!state->buf_off)
269             continue;
270 
271         // Does the existing buffer cover our section?
272         if ((start >= state->buf_start) &&
273             (start <= buf_end) &&
274             (clamped_end >= state->buf_start) &&
275             (clamped_end <= buf_end))
276         {
277             char *buf = state->orig_buf + (start - state->buf_start);
278 
279             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
280             if (clamped_len < len) {
281                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
282             }
283             acb->ret = 0;
284             return true;
285         }
286 
287         // Wait for unfinished chunks
288         if (state->in_use &&
289             (start >= state->buf_start) &&
290             (start <= buf_fend) &&
291             (clamped_end >= state->buf_start) &&
292             (clamped_end <= buf_fend))
293         {
294             int j;
295 
296             acb->start = start - state->buf_start;
297             acb->end = acb->start + clamped_len;
298 
299             for (j=0; j<CURL_NUM_ACB; j++) {
300                 if (!state->acb[j]) {
301                     state->acb[j] = acb;
302                     return true;
303                 }
304             }
305         }
306     }
307 
308     return false;
309 }
310 
311 /* Called with s->mutex held.  */
312 static void curl_multi_check_completion(BDRVCURLState *s)
313 {
314     int msgs_in_queue;
315 
316     /* Try to find done transfers, so we can free the easy
317      * handle again. */
318     for (;;) {
319         CURLMsg *msg;
320         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
321 
322         /* Quit when there are no more completions */
323         if (!msg)
324             break;
325 
326         if (msg->msg == CURLMSG_DONE) {
327             int i;
328             CURLState *state = NULL;
329             bool error = msg->data.result != CURLE_OK;
330 
331             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
332                               (char **)&state);
333 
334             if (error) {
335                 static int errcount = 100;
336 
337                 /* Don't lose the original error message from curl, since
338                  * it contains extra data.
339                  */
340                 if (errcount > 0) {
341                     error_report("curl: %s", state->errmsg);
342                     if (--errcount == 0) {
343                         error_report("curl: further errors suppressed");
344                     }
345                 }
346             }
347 
348             for (i = 0; i < CURL_NUM_ACB; i++) {
349                 CURLAIOCB *acb = state->acb[i];
350 
351                 if (acb == NULL) {
352                     continue;
353                 }
354 
355                 if (!error) {
356                     /* Assert that we have read all data */
357                     assert(state->buf_off >= acb->end);
358 
359                     qemu_iovec_from_buf(acb->qiov, 0,
360                                         state->orig_buf + acb->start,
361                                         acb->end - acb->start);
362 
363                     if (acb->end - acb->start < acb->bytes) {
364                         size_t offset = acb->end - acb->start;
365                         qemu_iovec_memset(acb->qiov, offset, 0,
366                                           acb->bytes - offset);
367                     }
368                 }
369 
370                 acb->ret = error ? -EIO : 0;
371                 state->acb[i] = NULL;
372                 qemu_mutex_unlock(&s->mutex);
373                 aio_co_wake(acb->co);
374                 qemu_mutex_lock(&s->mutex);
375             }
376 
377             curl_clean_state(state);
378             break;
379         }
380     }
381 }
382 
383 /* Called with s->mutex held.  */
384 static void curl_multi_do_locked(CURLSocket *socket)
385 {
386     BDRVCURLState *s = socket->state->s;
387     int running;
388     int r;
389 
390     if (!s->multi) {
391         return;
392     }
393 
394     do {
395         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
396     } while (r == CURLM_CALL_MULTI_PERFORM);
397 }
398 
399 static void curl_multi_do(void *arg)
400 {
401     CURLSocket *socket = arg;
402     BDRVCURLState *s = socket->state->s;
403 
404     qemu_mutex_lock(&s->mutex);
405     curl_multi_do_locked(socket);
406     curl_multi_check_completion(s);
407     qemu_mutex_unlock(&s->mutex);
408 }
409 
410 static void curl_multi_timeout_do(void *arg)
411 {
412 #ifdef NEED_CURL_TIMER_CALLBACK
413     BDRVCURLState *s = (BDRVCURLState *)arg;
414     int running;
415 
416     if (!s->multi) {
417         return;
418     }
419 
420     qemu_mutex_lock(&s->mutex);
421     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
422 
423     curl_multi_check_completion(s);
424     qemu_mutex_unlock(&s->mutex);
425 #else
426     abort();
427 #endif
428 }
429 
430 /* Called with s->mutex held.  */
431 static CURLState *curl_find_state(BDRVCURLState *s)
432 {
433     CURLState *state = NULL;
434     int i;
435 
436     for (i = 0; i < CURL_NUM_STATES; i++) {
437         if (!s->states[i].in_use) {
438             state = &s->states[i];
439             state->in_use = 1;
440             break;
441         }
442     }
443     return state;
444 }
445 
446 static int curl_init_state(BDRVCURLState *s, CURLState *state)
447 {
448     if (!state->curl) {
449         state->curl = curl_easy_init();
450         if (!state->curl) {
451             return -EIO;
452         }
453         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
454         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
455                          (long) s->sslverify);
456         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
457                          s->sslverify ? 2L : 0L);
458         if (s->cookie) {
459             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
460         }
461         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
462         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
463                          (void *)curl_read_cb);
464         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
465         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
466         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
467         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
468         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
469         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
470         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
471 
472         if (s->username) {
473             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
474         }
475         if (s->password) {
476             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
477         }
478         if (s->proxyusername) {
479             curl_easy_setopt(state->curl,
480                              CURLOPT_PROXYUSERNAME, s->proxyusername);
481         }
482         if (s->proxypassword) {
483             curl_easy_setopt(state->curl,
484                              CURLOPT_PROXYPASSWORD, s->proxypassword);
485         }
486 
487         /* Restrict supported protocols to avoid security issues in the more
488          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
489          * CVE-2013-0249.
490          *
491          * Restricting protocols is only supported from 7.19.4 upwards.
492          */
493 #if LIBCURL_VERSION_NUM >= 0x071304
494         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
495         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
496 #endif
497 
498 #ifdef DEBUG_VERBOSE
499         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
500 #endif
501     }
502 
503     QLIST_INIT(&state->sockets);
504     state->s = s;
505 
506     return 0;
507 }
508 
509 /* Called with s->mutex held.  */
510 static void curl_clean_state(CURLState *s)
511 {
512     int j;
513     for (j = 0; j < CURL_NUM_ACB; j++) {
514         assert(!s->acb[j]);
515     }
516 
517     if (s->s->multi)
518         curl_multi_remove_handle(s->s->multi, s->curl);
519 
520     while (!QLIST_EMPTY(&s->sockets)) {
521         CURLSocket *socket = QLIST_FIRST(&s->sockets);
522 
523         QLIST_REMOVE(socket, next);
524         g_free(socket);
525     }
526 
527     s->in_use = 0;
528 
529     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
530 }
531 
532 static void curl_parse_filename(const char *filename, QDict *options,
533                                 Error **errp)
534 {
535     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
536 }
537 
538 static void curl_detach_aio_context(BlockDriverState *bs)
539 {
540     BDRVCURLState *s = bs->opaque;
541     int i;
542 
543     qemu_mutex_lock(&s->mutex);
544     for (i = 0; i < CURL_NUM_STATES; i++) {
545         if (s->states[i].in_use) {
546             curl_clean_state(&s->states[i]);
547         }
548         if (s->states[i].curl) {
549             curl_easy_cleanup(s->states[i].curl);
550             s->states[i].curl = NULL;
551         }
552         g_free(s->states[i].orig_buf);
553         s->states[i].orig_buf = NULL;
554     }
555     if (s->multi) {
556         curl_multi_cleanup(s->multi);
557         s->multi = NULL;
558     }
559     qemu_mutex_unlock(&s->mutex);
560 
561     timer_del(&s->timer);
562 }
563 
564 static void curl_attach_aio_context(BlockDriverState *bs,
565                                     AioContext *new_context)
566 {
567     BDRVCURLState *s = bs->opaque;
568 
569     aio_timer_init(new_context, &s->timer,
570                    QEMU_CLOCK_REALTIME, SCALE_NS,
571                    curl_multi_timeout_do, s);
572 
573     assert(!s->multi);
574     s->multi = curl_multi_init();
575     s->aio_context = new_context;
576     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
577 #ifdef NEED_CURL_TIMER_CALLBACK
578     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
579     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
580 #endif
581 }
582 
583 static QemuOptsList runtime_opts = {
584     .name = "curl",
585     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
586     .desc = {
587         {
588             .name = CURL_BLOCK_OPT_URL,
589             .type = QEMU_OPT_STRING,
590             .help = "URL to open",
591         },
592         {
593             .name = CURL_BLOCK_OPT_READAHEAD,
594             .type = QEMU_OPT_SIZE,
595             .help = "Readahead size",
596         },
597         {
598             .name = CURL_BLOCK_OPT_SSLVERIFY,
599             .type = QEMU_OPT_BOOL,
600             .help = "Verify SSL certificate"
601         },
602         {
603             .name = CURL_BLOCK_OPT_TIMEOUT,
604             .type = QEMU_OPT_NUMBER,
605             .help = "Curl timeout"
606         },
607         {
608             .name = CURL_BLOCK_OPT_COOKIE,
609             .type = QEMU_OPT_STRING,
610             .help = "Pass the cookie or list of cookies with each request"
611         },
612         {
613             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
614             .type = QEMU_OPT_STRING,
615             .help = "ID of secret used as cookie passed with each request"
616         },
617         {
618             .name = CURL_BLOCK_OPT_USERNAME,
619             .type = QEMU_OPT_STRING,
620             .help = "Username for HTTP auth"
621         },
622         {
623             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
624             .type = QEMU_OPT_STRING,
625             .help = "ID of secret used as password for HTTP auth",
626         },
627         {
628             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
629             .type = QEMU_OPT_STRING,
630             .help = "Username for HTTP proxy auth"
631         },
632         {
633             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
634             .type = QEMU_OPT_STRING,
635             .help = "ID of secret used as password for HTTP proxy auth",
636         },
637         { /* end of list */ }
638     },
639 };
640 
641 
642 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
643                      Error **errp)
644 {
645     BDRVCURLState *s = bs->opaque;
646     CURLState *state = NULL;
647     QemuOpts *opts;
648     Error *local_err = NULL;
649     const char *file;
650     const char *cookie;
651     const char *cookie_secret;
652     double d;
653     const char *secretid;
654     const char *protocol_delimiter;
655     int ret;
656 
657     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
658                                     errp);
659     if (ret < 0) {
660         return ret;
661     }
662 
663     if (!libcurl_initialized) {
664         ret = curl_global_init(CURL_GLOBAL_ALL);
665         if (ret) {
666             error_setg(errp, "libcurl initialization failed with %d", ret);
667             return -EIO;
668         }
669         libcurl_initialized = true;
670     }
671 
672     qemu_mutex_init(&s->mutex);
673     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
674     qemu_opts_absorb_qdict(opts, options, &local_err);
675     if (local_err) {
676         error_propagate(errp, local_err);
677         goto out_noclean;
678     }
679 
680     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
681                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
682     if ((s->readahead_size & 0x1ff) != 0) {
683         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
684                    s->readahead_size);
685         goto out_noclean;
686     }
687 
688     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
689                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
690     if (s->timeout > CURL_TIMEOUT_MAX) {
691         error_setg(errp, "timeout parameter is too large or negative");
692         goto out_noclean;
693     }
694 
695     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
696                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
697 
698     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
699     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
700 
701     if (cookie && cookie_secret) {
702         error_setg(errp,
703                    "curl driver cannot handle both cookie and cookie secret");
704         goto out_noclean;
705     }
706 
707     if (cookie_secret) {
708         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
709         if (!s->cookie) {
710             goto out_noclean;
711         }
712     } else {
713         s->cookie = g_strdup(cookie);
714     }
715 
716     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
717     if (file == NULL) {
718         error_setg(errp, "curl block driver requires an 'url' option");
719         goto out_noclean;
720     }
721 
722     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
723         !strstart(protocol_delimiter, "://", NULL))
724     {
725         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
726                    "start with '%s://')", bs->drv->protocol_name, file,
727                    bs->drv->protocol_name);
728         goto out_noclean;
729     }
730 
731     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
732     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
733 
734     if (secretid) {
735         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
736         if (!s->password) {
737             goto out_noclean;
738         }
739     }
740 
741     s->proxyusername = g_strdup(
742         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
743     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
744     if (secretid) {
745         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
746         if (!s->proxypassword) {
747             goto out_noclean;
748         }
749     }
750 
751     trace_curl_open(file);
752     qemu_co_queue_init(&s->free_state_waitq);
753     s->aio_context = bdrv_get_aio_context(bs);
754     s->url = g_strdup(file);
755     qemu_mutex_lock(&s->mutex);
756     state = curl_find_state(s);
757     qemu_mutex_unlock(&s->mutex);
758     if (!state) {
759         goto out_noclean;
760     }
761 
762     // Get file size
763 
764     if (curl_init_state(s, state) < 0) {
765         goto out;
766     }
767 
768     s->accept_range = false;
769     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
770     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
771                      curl_header_cb);
772     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
773     if (curl_easy_perform(state->curl))
774         goto out;
775     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
776         goto out;
777     }
778     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
779      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
780      * known and zero if it is really zero-length file. */
781 #if LIBCURL_VERSION_NUM >= 0x071304
782     if (d < 0) {
783         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
784                 "Server didn't report file size.");
785         goto out;
786     }
787 #else
788     if (d <= 0) {
789         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
790                 "Unknown file size or zero-length file.");
791         goto out;
792     }
793 #endif
794 
795     s->len = d;
796 
797     if ((!strncasecmp(s->url, "http://", strlen("http://"))
798         || !strncasecmp(s->url, "https://", strlen("https://")))
799         && !s->accept_range) {
800         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
801                 "Server does not support 'range' (byte ranges).");
802         goto out;
803     }
804     trace_curl_open_size(s->len);
805 
806     qemu_mutex_lock(&s->mutex);
807     curl_clean_state(state);
808     qemu_mutex_unlock(&s->mutex);
809     curl_easy_cleanup(state->curl);
810     state->curl = NULL;
811 
812     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
813 
814     qemu_opts_del(opts);
815     return 0;
816 
817 out:
818     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
819     curl_easy_cleanup(state->curl);
820     state->curl = NULL;
821 out_noclean:
822     qemu_mutex_destroy(&s->mutex);
823     g_free(s->cookie);
824     g_free(s->url);
825     g_free(s->username);
826     g_free(s->proxyusername);
827     g_free(s->proxypassword);
828     qemu_opts_del(opts);
829     return -EINVAL;
830 }
831 
832 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
833 {
834     CURLState *state;
835     int running;
836 
837     BDRVCURLState *s = bs->opaque;
838 
839     uint64_t start = acb->offset;
840     uint64_t end;
841 
842     qemu_mutex_lock(&s->mutex);
843 
844     // In case we have the requested data already (e.g. read-ahead),
845     // we can just call the callback and be done.
846     if (curl_find_buf(s, start, acb->bytes, acb)) {
847         goto out;
848     }
849 
850     // No cache found, so let's start a new request
851     for (;;) {
852         state = curl_find_state(s);
853         if (state) {
854             break;
855         }
856         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
857     }
858 
859     if (curl_init_state(s, state) < 0) {
860         curl_clean_state(state);
861         acb->ret = -EIO;
862         goto out;
863     }
864 
865     acb->start = 0;
866     acb->end = MIN(acb->bytes, s->len - start);
867 
868     state->buf_off = 0;
869     g_free(state->orig_buf);
870     state->buf_start = start;
871     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
872     end = start + state->buf_len - 1;
873     state->orig_buf = g_try_malloc(state->buf_len);
874     if (state->buf_len && state->orig_buf == NULL) {
875         curl_clean_state(state);
876         acb->ret = -ENOMEM;
877         goto out;
878     }
879     state->acb[0] = acb;
880 
881     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
882     trace_curl_setup_preadv(acb->bytes, start, state->range);
883     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
884 
885     if (curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
886         state->acb[0] = NULL;
887         acb->ret = -EIO;
888 
889         curl_clean_state(state);
890         goto out;
891     }
892 
893     /* Tell curl it needs to kick things off */
894     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
895 
896 out:
897     qemu_mutex_unlock(&s->mutex);
898 }
899 
900 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
901         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
902 {
903     CURLAIOCB acb = {
904         .co = qemu_coroutine_self(),
905         .ret = -EINPROGRESS,
906         .qiov = qiov,
907         .offset = offset,
908         .bytes = bytes
909     };
910 
911     curl_setup_preadv(bs, &acb);
912     while (acb.ret == -EINPROGRESS) {
913         qemu_coroutine_yield();
914     }
915     return acb.ret;
916 }
917 
918 static void curl_close(BlockDriverState *bs)
919 {
920     BDRVCURLState *s = bs->opaque;
921 
922     trace_curl_close();
923     curl_detach_aio_context(bs);
924     qemu_mutex_destroy(&s->mutex);
925 
926     g_free(s->cookie);
927     g_free(s->url);
928     g_free(s->username);
929     g_free(s->proxyusername);
930     g_free(s->proxypassword);
931 }
932 
933 static int64_t curl_getlength(BlockDriverState *bs)
934 {
935     BDRVCURLState *s = bs->opaque;
936     return s->len;
937 }
938 
939 static void curl_refresh_filename(BlockDriverState *bs)
940 {
941     BDRVCURLState *s = bs->opaque;
942 
943     /* "readahead" and "timeout" do not change the guest-visible data,
944      * so ignore them */
945     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
946         s->cookie || s->username || s->password || s->proxyusername ||
947         s->proxypassword)
948     {
949         return;
950     }
951 
952     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
953 }
954 
955 
956 static const char *const curl_strong_runtime_opts[] = {
957     CURL_BLOCK_OPT_URL,
958     CURL_BLOCK_OPT_SSLVERIFY,
959     CURL_BLOCK_OPT_COOKIE,
960     CURL_BLOCK_OPT_COOKIE_SECRET,
961     CURL_BLOCK_OPT_USERNAME,
962     CURL_BLOCK_OPT_PASSWORD_SECRET,
963     CURL_BLOCK_OPT_PROXY_USERNAME,
964     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
965 
966     NULL
967 };
968 
969 static BlockDriver bdrv_http = {
970     .format_name                = "http",
971     .protocol_name              = "http",
972 
973     .instance_size              = sizeof(BDRVCURLState),
974     .bdrv_parse_filename        = curl_parse_filename,
975     .bdrv_file_open             = curl_open,
976     .bdrv_close                 = curl_close,
977     .bdrv_getlength             = curl_getlength,
978 
979     .bdrv_co_preadv             = curl_co_preadv,
980 
981     .bdrv_detach_aio_context    = curl_detach_aio_context,
982     .bdrv_attach_aio_context    = curl_attach_aio_context,
983 
984     .bdrv_refresh_filename      = curl_refresh_filename,
985     .strong_runtime_opts        = curl_strong_runtime_opts,
986 };
987 
988 static BlockDriver bdrv_https = {
989     .format_name                = "https",
990     .protocol_name              = "https",
991 
992     .instance_size              = sizeof(BDRVCURLState),
993     .bdrv_parse_filename        = curl_parse_filename,
994     .bdrv_file_open             = curl_open,
995     .bdrv_close                 = curl_close,
996     .bdrv_getlength             = curl_getlength,
997 
998     .bdrv_co_preadv             = curl_co_preadv,
999 
1000     .bdrv_detach_aio_context    = curl_detach_aio_context,
1001     .bdrv_attach_aio_context    = curl_attach_aio_context,
1002 
1003     .bdrv_refresh_filename      = curl_refresh_filename,
1004     .strong_runtime_opts        = curl_strong_runtime_opts,
1005 };
1006 
1007 static BlockDriver bdrv_ftp = {
1008     .format_name                = "ftp",
1009     .protocol_name              = "ftp",
1010 
1011     .instance_size              = sizeof(BDRVCURLState),
1012     .bdrv_parse_filename        = curl_parse_filename,
1013     .bdrv_file_open             = curl_open,
1014     .bdrv_close                 = curl_close,
1015     .bdrv_getlength             = curl_getlength,
1016 
1017     .bdrv_co_preadv             = curl_co_preadv,
1018 
1019     .bdrv_detach_aio_context    = curl_detach_aio_context,
1020     .bdrv_attach_aio_context    = curl_attach_aio_context,
1021 
1022     .bdrv_refresh_filename      = curl_refresh_filename,
1023     .strong_runtime_opts        = curl_strong_runtime_opts,
1024 };
1025 
1026 static BlockDriver bdrv_ftps = {
1027     .format_name                = "ftps",
1028     .protocol_name              = "ftps",
1029 
1030     .instance_size              = sizeof(BDRVCURLState),
1031     .bdrv_parse_filename        = curl_parse_filename,
1032     .bdrv_file_open             = curl_open,
1033     .bdrv_close                 = curl_close,
1034     .bdrv_getlength             = curl_getlength,
1035 
1036     .bdrv_co_preadv             = curl_co_preadv,
1037 
1038     .bdrv_detach_aio_context    = curl_detach_aio_context,
1039     .bdrv_attach_aio_context    = curl_attach_aio_context,
1040 
1041     .bdrv_refresh_filename      = curl_refresh_filename,
1042     .strong_runtime_opts        = curl_strong_runtime_opts,
1043 };
1044 
1045 static void curl_block_init(void)
1046 {
1047     bdrv_register(&bdrv_http);
1048     bdrv_register(&bdrv_https);
1049     bdrv_register(&bdrv_ftp);
1050     bdrv_register(&bdrv_ftps);
1051 }
1052 
1053 block_init(curl_block_init);
1054