xref: /qemu/block/curl.c (revision 9277d81f)
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/option.h"
29 #include "block/block_int.h"
30 #include "qapi/qmp/qdict.h"
31 #include "qapi/qmp/qstring.h"
32 #include "crypto/secret.h"
33 #include <curl/curl.h>
34 #include "qemu/cutils.h"
35 
36 // #define DEBUG_CURL
37 // #define DEBUG_VERBOSE
38 
39 #ifdef DEBUG_CURL
40 #define DEBUG_CURL_PRINT 1
41 #else
42 #define DEBUG_CURL_PRINT 0
43 #endif
44 #define DPRINTF(fmt, ...)                                            \
45     do {                                                             \
46         if (DEBUG_CURL_PRINT) {                                      \
47             fprintf(stderr, fmt, ## __VA_ARGS__);                    \
48         }                                                            \
49     } while (0)
50 
51 #if LIBCURL_VERSION_NUM >= 0x071000
52 /* The multi interface timer callback was introduced in 7.16.0 */
53 #define NEED_CURL_TIMER_CALLBACK
54 #define HAVE_SOCKET_ACTION
55 #endif
56 
57 #ifndef HAVE_SOCKET_ACTION
58 /* If curl_multi_socket_action isn't available, define it statically here in
59  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
60  * less efficient but still safe. */
61 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
62                                             curl_socket_t sockfd,
63                                             int ev_bitmask,
64                                             int *running_handles)
65 {
66     return curl_multi_socket(multi_handle, sockfd, running_handles);
67 }
68 #define curl_multi_socket_action __curl_multi_socket_action
69 #endif
70 
71 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
72                    CURLPROTO_FTP | CURLPROTO_FTPS)
73 
74 #define CURL_NUM_STATES 8
75 #define CURL_NUM_ACB    8
76 #define READ_AHEAD_DEFAULT (256 * 1024)
77 #define CURL_TIMEOUT_DEFAULT 5
78 #define CURL_TIMEOUT_MAX 10000
79 
80 #define CURL_BLOCK_OPT_URL       "url"
81 #define CURL_BLOCK_OPT_READAHEAD "readahead"
82 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
83 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
84 #define CURL_BLOCK_OPT_COOKIE    "cookie"
85 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
86 #define CURL_BLOCK_OPT_USERNAME "username"
87 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
88 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
89 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
90 
91 struct BDRVCURLState;
92 
93 static bool libcurl_initialized;
94 
95 typedef struct CURLAIOCB {
96     Coroutine *co;
97     QEMUIOVector *qiov;
98 
99     uint64_t offset;
100     uint64_t bytes;
101     int ret;
102 
103     size_t start;
104     size_t end;
105 } CURLAIOCB;
106 
107 typedef struct CURLSocket {
108     int fd;
109     QLIST_ENTRY(CURLSocket) next;
110 } CURLSocket;
111 
112 typedef struct CURLState
113 {
114     struct BDRVCURLState *s;
115     CURLAIOCB *acb[CURL_NUM_ACB];
116     CURL *curl;
117     QLIST_HEAD(, CURLSocket) sockets;
118     char *orig_buf;
119     uint64_t buf_start;
120     size_t buf_off;
121     size_t buf_len;
122     char range[128];
123     char errmsg[CURL_ERROR_SIZE];
124     char in_use;
125 } CURLState;
126 
127 typedef struct BDRVCURLState {
128     CURLM *multi;
129     QEMUTimer timer;
130     uint64_t len;
131     CURLState states[CURL_NUM_STATES];
132     char *url;
133     size_t readahead_size;
134     bool sslverify;
135     uint64_t timeout;
136     char *cookie;
137     bool accept_range;
138     AioContext *aio_context;
139     QemuMutex mutex;
140     CoQueue free_state_waitq;
141     char *username;
142     char *password;
143     char *proxyusername;
144     char *proxypassword;
145 } BDRVCURLState;
146 
147 static void curl_clean_state(CURLState *s);
148 static void curl_multi_do(void *arg);
149 static void curl_multi_read(void *arg);
150 
151 #ifdef NEED_CURL_TIMER_CALLBACK
152 /* Called from curl_multi_do_locked, with s->mutex held.  */
153 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
154 {
155     BDRVCURLState *s = opaque;
156 
157     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
158     if (timeout_ms == -1) {
159         timer_del(&s->timer);
160     } else {
161         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
162         timer_mod(&s->timer,
163                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
164     }
165     return 0;
166 }
167 #endif
168 
169 /* Called from curl_multi_do_locked, with s->mutex held.  */
170 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
171                         void *userp, void *sp)
172 {
173     BDRVCURLState *s;
174     CURLState *state = NULL;
175     CURLSocket *socket;
176 
177     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
178     s = state->s;
179 
180     QLIST_FOREACH(socket, &state->sockets, next) {
181         if (socket->fd == fd) {
182             if (action == CURL_POLL_REMOVE) {
183                 QLIST_REMOVE(socket, next);
184                 g_free(socket);
185             }
186             break;
187         }
188     }
189     if (!socket) {
190         socket = g_new0(CURLSocket, 1);
191         socket->fd = fd;
192         QLIST_INSERT_HEAD(&state->sockets, socket, next);
193     }
194     socket = NULL;
195 
196     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, (int)fd);
197     switch (action) {
198         case CURL_POLL_IN:
199             aio_set_fd_handler(s->aio_context, fd, false,
200                                curl_multi_read, NULL, NULL, state);
201             break;
202         case CURL_POLL_OUT:
203             aio_set_fd_handler(s->aio_context, fd, false,
204                                NULL, curl_multi_do, NULL, state);
205             break;
206         case CURL_POLL_INOUT:
207             aio_set_fd_handler(s->aio_context, fd, false,
208                                curl_multi_read, curl_multi_do, NULL, state);
209             break;
210         case CURL_POLL_REMOVE:
211             aio_set_fd_handler(s->aio_context, fd, false,
212                                NULL, NULL, NULL, NULL);
213             break;
214     }
215 
216     return 0;
217 }
218 
219 /* Called from curl_multi_do_locked, with s->mutex held.  */
220 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
221 {
222     BDRVCURLState *s = opaque;
223     size_t realsize = size * nmemb;
224     const char *accept_line = "Accept-Ranges: bytes";
225 
226     if (realsize >= strlen(accept_line)
227         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
228         s->accept_range = true;
229     }
230 
231     return realsize;
232 }
233 
234 /* Called from curl_multi_do_locked, with s->mutex held.  */
235 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
236 {
237     CURLState *s = ((CURLState*)opaque);
238     size_t realsize = size * nmemb;
239     int i;
240 
241     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
242 
243     if (!s || !s->orig_buf) {
244         goto read_end;
245     }
246 
247     if (s->buf_off >= s->buf_len) {
248         /* buffer full, read nothing */
249         goto read_end;
250     }
251     realsize = MIN(realsize, s->buf_len - s->buf_off);
252     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
253     s->buf_off += realsize;
254 
255     for(i=0; i<CURL_NUM_ACB; i++) {
256         CURLAIOCB *acb = s->acb[i];
257 
258         if (!acb)
259             continue;
260 
261         if ((s->buf_off >= acb->end)) {
262             size_t request_length = acb->bytes;
263 
264             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
265                                 acb->end - acb->start);
266 
267             if (acb->end - acb->start < request_length) {
268                 size_t offset = acb->end - acb->start;
269                 qemu_iovec_memset(acb->qiov, offset, 0,
270                                   request_length - offset);
271             }
272 
273             acb->ret = 0;
274             s->acb[i] = NULL;
275             qemu_mutex_unlock(&s->s->mutex);
276             aio_co_wake(acb->co);
277             qemu_mutex_lock(&s->s->mutex);
278         }
279     }
280 
281 read_end:
282     /* curl will error out if we do not return this value */
283     return size * nmemb;
284 }
285 
286 /* Called with s->mutex held.  */
287 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
288                           CURLAIOCB *acb)
289 {
290     int i;
291     uint64_t end = start + len;
292     uint64_t clamped_end = MIN(end, s->len);
293     uint64_t clamped_len = clamped_end - start;
294 
295     for (i=0; i<CURL_NUM_STATES; i++) {
296         CURLState *state = &s->states[i];
297         uint64_t buf_end = (state->buf_start + state->buf_off);
298         uint64_t buf_fend = (state->buf_start + state->buf_len);
299 
300         if (!state->orig_buf)
301             continue;
302         if (!state->buf_off)
303             continue;
304 
305         // Does the existing buffer cover our section?
306         if ((start >= state->buf_start) &&
307             (start <= buf_end) &&
308             (clamped_end >= state->buf_start) &&
309             (clamped_end <= buf_end))
310         {
311             char *buf = state->orig_buf + (start - state->buf_start);
312 
313             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
314             if (clamped_len < len) {
315                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
316             }
317             acb->ret = 0;
318             return true;
319         }
320 
321         // Wait for unfinished chunks
322         if (state->in_use &&
323             (start >= state->buf_start) &&
324             (start <= buf_fend) &&
325             (clamped_end >= state->buf_start) &&
326             (clamped_end <= buf_fend))
327         {
328             int j;
329 
330             acb->start = start - state->buf_start;
331             acb->end = acb->start + clamped_len;
332 
333             for (j=0; j<CURL_NUM_ACB; j++) {
334                 if (!state->acb[j]) {
335                     state->acb[j] = acb;
336                     return true;
337                 }
338             }
339         }
340     }
341 
342     return false;
343 }
344 
345 /* Called with s->mutex held.  */
346 static void curl_multi_check_completion(BDRVCURLState *s)
347 {
348     int msgs_in_queue;
349 
350     /* Try to find done transfers, so we can free the easy
351      * handle again. */
352     for (;;) {
353         CURLMsg *msg;
354         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
355 
356         /* Quit when there are no more completions */
357         if (!msg)
358             break;
359 
360         if (msg->msg == CURLMSG_DONE) {
361             CURLState *state = NULL;
362             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
363                               (char **)&state);
364 
365             /* ACBs for successful messages get completed in curl_read_cb */
366             if (msg->data.result != CURLE_OK) {
367                 int i;
368                 static int errcount = 100;
369 
370                 /* Don't lose the original error message from curl, since
371                  * it contains extra data.
372                  */
373                 if (errcount > 0) {
374                     error_report("curl: %s", state->errmsg);
375                     if (--errcount == 0) {
376                         error_report("curl: further errors suppressed");
377                     }
378                 }
379 
380                 for (i = 0; i < CURL_NUM_ACB; i++) {
381                     CURLAIOCB *acb = state->acb[i];
382 
383                     if (acb == NULL) {
384                         continue;
385                     }
386 
387                     acb->ret = -EIO;
388                     state->acb[i] = NULL;
389                     qemu_mutex_unlock(&s->mutex);
390                     aio_co_wake(acb->co);
391                     qemu_mutex_lock(&s->mutex);
392                 }
393             }
394 
395             curl_clean_state(state);
396             break;
397         }
398     }
399 }
400 
401 /* Called with s->mutex held.  */
402 static void curl_multi_do_locked(CURLState *s)
403 {
404     CURLSocket *socket, *next_socket;
405     int running;
406     int r;
407 
408     if (!s->s->multi) {
409         return;
410     }
411 
412     /* Need to use _SAFE because curl_multi_socket_action() may trigger
413      * curl_sock_cb() which might modify this list */
414     QLIST_FOREACH_SAFE(socket, &s->sockets, next, next_socket) {
415         do {
416             r = curl_multi_socket_action(s->s->multi, socket->fd, 0, &running);
417         } while (r == CURLM_CALL_MULTI_PERFORM);
418     }
419 }
420 
421 static void curl_multi_do(void *arg)
422 {
423     CURLState *s = (CURLState *)arg;
424 
425     qemu_mutex_lock(&s->s->mutex);
426     curl_multi_do_locked(s);
427     qemu_mutex_unlock(&s->s->mutex);
428 }
429 
430 static void curl_multi_read(void *arg)
431 {
432     CURLState *s = (CURLState *)arg;
433 
434     qemu_mutex_lock(&s->s->mutex);
435     curl_multi_do_locked(s);
436     curl_multi_check_completion(s->s);
437     qemu_mutex_unlock(&s->s->mutex);
438 }
439 
440 static void curl_multi_timeout_do(void *arg)
441 {
442 #ifdef NEED_CURL_TIMER_CALLBACK
443     BDRVCURLState *s = (BDRVCURLState *)arg;
444     int running;
445 
446     if (!s->multi) {
447         return;
448     }
449 
450     qemu_mutex_lock(&s->mutex);
451     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
452 
453     curl_multi_check_completion(s);
454     qemu_mutex_unlock(&s->mutex);
455 #else
456     abort();
457 #endif
458 }
459 
460 /* Called with s->mutex held.  */
461 static CURLState *curl_find_state(BDRVCURLState *s)
462 {
463     CURLState *state = NULL;
464     int i;
465 
466     for (i = 0; i < CURL_NUM_STATES; i++) {
467         if (!s->states[i].in_use) {
468             state = &s->states[i];
469             state->in_use = 1;
470             break;
471         }
472     }
473     return state;
474 }
475 
476 static int curl_init_state(BDRVCURLState *s, CURLState *state)
477 {
478     if (!state->curl) {
479         state->curl = curl_easy_init();
480         if (!state->curl) {
481             return -EIO;
482         }
483         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
484         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
485                          (long) s->sslverify);
486         if (s->cookie) {
487             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
488         }
489         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
490         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
491                          (void *)curl_read_cb);
492         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
493         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
494         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
495         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
496         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
497         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
498         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
499 
500         if (s->username) {
501             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
502         }
503         if (s->password) {
504             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
505         }
506         if (s->proxyusername) {
507             curl_easy_setopt(state->curl,
508                              CURLOPT_PROXYUSERNAME, s->proxyusername);
509         }
510         if (s->proxypassword) {
511             curl_easy_setopt(state->curl,
512                              CURLOPT_PROXYPASSWORD, s->proxypassword);
513         }
514 
515         /* Restrict supported protocols to avoid security issues in the more
516          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
517          * CVE-2013-0249.
518          *
519          * Restricting protocols is only supported from 7.19.4 upwards.
520          */
521 #if LIBCURL_VERSION_NUM >= 0x071304
522         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
523         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
524 #endif
525 
526 #ifdef DEBUG_VERBOSE
527         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
528 #endif
529     }
530 
531     QLIST_INIT(&state->sockets);
532     state->s = s;
533 
534     return 0;
535 }
536 
537 /* Called with s->mutex held.  */
538 static void curl_clean_state(CURLState *s)
539 {
540     int j;
541     for (j = 0; j < CURL_NUM_ACB; j++) {
542         assert(!s->acb[j]);
543     }
544 
545     if (s->s->multi)
546         curl_multi_remove_handle(s->s->multi, s->curl);
547 
548     while (!QLIST_EMPTY(&s->sockets)) {
549         CURLSocket *socket = QLIST_FIRST(&s->sockets);
550 
551         QLIST_REMOVE(socket, next);
552         g_free(socket);
553     }
554 
555     s->in_use = 0;
556 
557     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
558 }
559 
560 static void curl_parse_filename(const char *filename, QDict *options,
561                                 Error **errp)
562 {
563     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
564 }
565 
566 static void curl_detach_aio_context(BlockDriverState *bs)
567 {
568     BDRVCURLState *s = bs->opaque;
569     int i;
570 
571     qemu_mutex_lock(&s->mutex);
572     for (i = 0; i < CURL_NUM_STATES; i++) {
573         if (s->states[i].in_use) {
574             curl_clean_state(&s->states[i]);
575         }
576         if (s->states[i].curl) {
577             curl_easy_cleanup(s->states[i].curl);
578             s->states[i].curl = NULL;
579         }
580         g_free(s->states[i].orig_buf);
581         s->states[i].orig_buf = NULL;
582     }
583     if (s->multi) {
584         curl_multi_cleanup(s->multi);
585         s->multi = NULL;
586     }
587     qemu_mutex_unlock(&s->mutex);
588 
589     timer_del(&s->timer);
590 }
591 
592 static void curl_attach_aio_context(BlockDriverState *bs,
593                                     AioContext *new_context)
594 {
595     BDRVCURLState *s = bs->opaque;
596 
597     aio_timer_init(new_context, &s->timer,
598                    QEMU_CLOCK_REALTIME, SCALE_NS,
599                    curl_multi_timeout_do, s);
600 
601     assert(!s->multi);
602     s->multi = curl_multi_init();
603     s->aio_context = new_context;
604     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
605 #ifdef NEED_CURL_TIMER_CALLBACK
606     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
607     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
608 #endif
609 }
610 
611 static QemuOptsList runtime_opts = {
612     .name = "curl",
613     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
614     .desc = {
615         {
616             .name = CURL_BLOCK_OPT_URL,
617             .type = QEMU_OPT_STRING,
618             .help = "URL to open",
619         },
620         {
621             .name = CURL_BLOCK_OPT_READAHEAD,
622             .type = QEMU_OPT_SIZE,
623             .help = "Readahead size",
624         },
625         {
626             .name = CURL_BLOCK_OPT_SSLVERIFY,
627             .type = QEMU_OPT_BOOL,
628             .help = "Verify SSL certificate"
629         },
630         {
631             .name = CURL_BLOCK_OPT_TIMEOUT,
632             .type = QEMU_OPT_NUMBER,
633             .help = "Curl timeout"
634         },
635         {
636             .name = CURL_BLOCK_OPT_COOKIE,
637             .type = QEMU_OPT_STRING,
638             .help = "Pass the cookie or list of cookies with each request"
639         },
640         {
641             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
642             .type = QEMU_OPT_STRING,
643             .help = "ID of secret used as cookie passed with each request"
644         },
645         {
646             .name = CURL_BLOCK_OPT_USERNAME,
647             .type = QEMU_OPT_STRING,
648             .help = "Username for HTTP auth"
649         },
650         {
651             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
652             .type = QEMU_OPT_STRING,
653             .help = "ID of secret used as password for HTTP auth",
654         },
655         {
656             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
657             .type = QEMU_OPT_STRING,
658             .help = "Username for HTTP proxy auth"
659         },
660         {
661             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
662             .type = QEMU_OPT_STRING,
663             .help = "ID of secret used as password for HTTP proxy auth",
664         },
665         { /* end of list */ }
666     },
667 };
668 
669 
670 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
671                      Error **errp)
672 {
673     BDRVCURLState *s = bs->opaque;
674     CURLState *state = NULL;
675     QemuOpts *opts;
676     Error *local_err = NULL;
677     const char *file;
678     const char *cookie;
679     const char *cookie_secret;
680     double d;
681     const char *secretid;
682     const char *protocol_delimiter;
683     int ret;
684 
685 
686     if (flags & BDRV_O_RDWR) {
687         error_setg(errp, "curl block device does not support writes");
688         return -EROFS;
689     }
690 
691     if (!libcurl_initialized) {
692         ret = curl_global_init(CURL_GLOBAL_ALL);
693         if (ret) {
694             error_setg(errp, "libcurl initialization failed with %d", ret);
695             return -EIO;
696         }
697         libcurl_initialized = true;
698     }
699 
700     qemu_mutex_init(&s->mutex);
701     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
702     qemu_opts_absorb_qdict(opts, options, &local_err);
703     if (local_err) {
704         error_propagate(errp, local_err);
705         goto out_noclean;
706     }
707 
708     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
709                                           READ_AHEAD_DEFAULT);
710     if ((s->readahead_size & 0x1ff) != 0) {
711         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
712                    s->readahead_size);
713         goto out_noclean;
714     }
715 
716     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
717                                      CURL_TIMEOUT_DEFAULT);
718     if (s->timeout > CURL_TIMEOUT_MAX) {
719         error_setg(errp, "timeout parameter is too large or negative");
720         goto out_noclean;
721     }
722 
723     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
724 
725     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
726     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
727 
728     if (cookie && cookie_secret) {
729         error_setg(errp,
730                    "curl driver cannot handle both cookie and cookie secret");
731         goto out_noclean;
732     }
733 
734     if (cookie_secret) {
735         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
736         if (!s->cookie) {
737             goto out_noclean;
738         }
739     } else {
740         s->cookie = g_strdup(cookie);
741     }
742 
743     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
744     if (file == NULL) {
745         error_setg(errp, "curl block driver requires an 'url' option");
746         goto out_noclean;
747     }
748 
749     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
750         !strstart(protocol_delimiter, "://", NULL))
751     {
752         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
753                    "start with '%s://')", bs->drv->protocol_name, file,
754                    bs->drv->protocol_name);
755         goto out_noclean;
756     }
757 
758     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
759     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
760 
761     if (secretid) {
762         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
763         if (!s->password) {
764             goto out_noclean;
765         }
766     }
767 
768     s->proxyusername = g_strdup(
769         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
770     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
771     if (secretid) {
772         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
773         if (!s->proxypassword) {
774             goto out_noclean;
775         }
776     }
777 
778     DPRINTF("CURL: Opening %s\n", file);
779     qemu_co_queue_init(&s->free_state_waitq);
780     s->aio_context = bdrv_get_aio_context(bs);
781     s->url = g_strdup(file);
782     qemu_mutex_lock(&s->mutex);
783     state = curl_find_state(s);
784     qemu_mutex_unlock(&s->mutex);
785     if (!state) {
786         goto out_noclean;
787     }
788 
789     // Get file size
790 
791     if (curl_init_state(s, state) < 0) {
792         goto out;
793     }
794 
795     s->accept_range = false;
796     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
797     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
798                      curl_header_cb);
799     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
800     if (curl_easy_perform(state->curl))
801         goto out;
802     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
803         goto out;
804     }
805     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
806      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
807      * known and zero if it is realy zero-length file. */
808 #if LIBCURL_VERSION_NUM >= 0x071304
809     if (d < 0) {
810         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
811                 "Server didn't report file size.");
812         goto out;
813     }
814 #else
815     if (d <= 0) {
816         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
817                 "Unknown file size or zero-length file.");
818         goto out;
819     }
820 #endif
821 
822     s->len = d;
823 
824     if ((!strncasecmp(s->url, "http://", strlen("http://"))
825         || !strncasecmp(s->url, "https://", strlen("https://")))
826         && !s->accept_range) {
827         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
828                 "Server does not support 'range' (byte ranges).");
829         goto out;
830     }
831     DPRINTF("CURL: Size = %" PRIu64 "\n", s->len);
832 
833     qemu_mutex_lock(&s->mutex);
834     curl_clean_state(state);
835     qemu_mutex_unlock(&s->mutex);
836     curl_easy_cleanup(state->curl);
837     state->curl = NULL;
838 
839     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
840 
841     qemu_opts_del(opts);
842     return 0;
843 
844 out:
845     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
846     curl_easy_cleanup(state->curl);
847     state->curl = NULL;
848 out_noclean:
849     qemu_mutex_destroy(&s->mutex);
850     g_free(s->cookie);
851     g_free(s->url);
852     g_free(s->username);
853     g_free(s->proxyusername);
854     g_free(s->proxypassword);
855     qemu_opts_del(opts);
856     return -EINVAL;
857 }
858 
859 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
860 {
861     CURLState *state;
862     int running;
863 
864     BDRVCURLState *s = bs->opaque;
865 
866     uint64_t start = acb->offset;
867     uint64_t end;
868 
869     qemu_mutex_lock(&s->mutex);
870 
871     // In case we have the requested data already (e.g. read-ahead),
872     // we can just call the callback and be done.
873     if (curl_find_buf(s, start, acb->bytes, acb)) {
874         goto out;
875     }
876 
877     // No cache found, so let's start a new request
878     for (;;) {
879         state = curl_find_state(s);
880         if (state) {
881             break;
882         }
883         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
884     }
885 
886     if (curl_init_state(s, state) < 0) {
887         curl_clean_state(state);
888         acb->ret = -EIO;
889         goto out;
890     }
891 
892     acb->start = 0;
893     acb->end = MIN(acb->bytes, s->len - start);
894 
895     state->buf_off = 0;
896     g_free(state->orig_buf);
897     state->buf_start = start;
898     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
899     end = start + state->buf_len - 1;
900     state->orig_buf = g_try_malloc(state->buf_len);
901     if (state->buf_len && state->orig_buf == NULL) {
902         curl_clean_state(state);
903         acb->ret = -ENOMEM;
904         goto out;
905     }
906     state->acb[0] = acb;
907 
908     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
909     DPRINTF("CURL (AIO): Reading %" PRIu64 " at %" PRIu64 " (%s)\n",
910             acb->bytes, start, state->range);
911     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
912 
913     curl_multi_add_handle(s->multi, state->curl);
914 
915     /* Tell curl it needs to kick things off */
916     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
917 
918 out:
919     qemu_mutex_unlock(&s->mutex);
920 }
921 
922 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
923         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
924 {
925     CURLAIOCB acb = {
926         .co = qemu_coroutine_self(),
927         .ret = -EINPROGRESS,
928         .qiov = qiov,
929         .offset = offset,
930         .bytes = bytes
931     };
932 
933     curl_setup_preadv(bs, &acb);
934     while (acb.ret == -EINPROGRESS) {
935         qemu_coroutine_yield();
936     }
937     return acb.ret;
938 }
939 
940 static void curl_close(BlockDriverState *bs)
941 {
942     BDRVCURLState *s = bs->opaque;
943 
944     DPRINTF("CURL: Close\n");
945     curl_detach_aio_context(bs);
946     qemu_mutex_destroy(&s->mutex);
947 
948     g_free(s->cookie);
949     g_free(s->url);
950     g_free(s->username);
951     g_free(s->proxyusername);
952     g_free(s->proxypassword);
953 }
954 
955 static int64_t curl_getlength(BlockDriverState *bs)
956 {
957     BDRVCURLState *s = bs->opaque;
958     return s->len;
959 }
960 
961 static BlockDriver bdrv_http = {
962     .format_name                = "http",
963     .protocol_name              = "http",
964 
965     .instance_size              = sizeof(BDRVCURLState),
966     .bdrv_parse_filename        = curl_parse_filename,
967     .bdrv_file_open             = curl_open,
968     .bdrv_close                 = curl_close,
969     .bdrv_getlength             = curl_getlength,
970 
971     .bdrv_co_preadv             = curl_co_preadv,
972 
973     .bdrv_detach_aio_context    = curl_detach_aio_context,
974     .bdrv_attach_aio_context    = curl_attach_aio_context,
975 };
976 
977 static BlockDriver bdrv_https = {
978     .format_name                = "https",
979     .protocol_name              = "https",
980 
981     .instance_size              = sizeof(BDRVCURLState),
982     .bdrv_parse_filename        = curl_parse_filename,
983     .bdrv_file_open             = curl_open,
984     .bdrv_close                 = curl_close,
985     .bdrv_getlength             = curl_getlength,
986 
987     .bdrv_co_preadv             = curl_co_preadv,
988 
989     .bdrv_detach_aio_context    = curl_detach_aio_context,
990     .bdrv_attach_aio_context    = curl_attach_aio_context,
991 };
992 
993 static BlockDriver bdrv_ftp = {
994     .format_name                = "ftp",
995     .protocol_name              = "ftp",
996 
997     .instance_size              = sizeof(BDRVCURLState),
998     .bdrv_parse_filename        = curl_parse_filename,
999     .bdrv_file_open             = curl_open,
1000     .bdrv_close                 = curl_close,
1001     .bdrv_getlength             = curl_getlength,
1002 
1003     .bdrv_co_preadv             = curl_co_preadv,
1004 
1005     .bdrv_detach_aio_context    = curl_detach_aio_context,
1006     .bdrv_attach_aio_context    = curl_attach_aio_context,
1007 };
1008 
1009 static BlockDriver bdrv_ftps = {
1010     .format_name                = "ftps",
1011     .protocol_name              = "ftps",
1012 
1013     .instance_size              = sizeof(BDRVCURLState),
1014     .bdrv_parse_filename        = curl_parse_filename,
1015     .bdrv_file_open             = curl_open,
1016     .bdrv_close                 = curl_close,
1017     .bdrv_getlength             = curl_getlength,
1018 
1019     .bdrv_co_preadv             = curl_co_preadv,
1020 
1021     .bdrv_detach_aio_context    = curl_detach_aio_context,
1022     .bdrv_attach_aio_context    = curl_attach_aio_context,
1023 };
1024 
1025 static void curl_block_init(void)
1026 {
1027     bdrv_register(&bdrv_http);
1028     bdrv_register(&bdrv_https);
1029     bdrv_register(&bdrv_ftp);
1030     bdrv_register(&bdrv_ftps);
1031 }
1032 
1033 block_init(curl_block_init);
1034