xref: /openbmc/qemu/block/curl.c (revision e84328fa)
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 
84 static bool libcurl_initialized;
85 
86 typedef struct CURLAIOCB {
87     Coroutine *co;
88     QEMUIOVector *qiov;
89 
90     uint64_t offset;
91     uint64_t bytes;
92     int ret;
93 
94     size_t start;
95     size_t end;
96 } CURLAIOCB;
97 
98 typedef struct CURLSocket {
99     int fd;
100     QLIST_ENTRY(CURLSocket) next;
101 } CURLSocket;
102 
103 typedef struct CURLState
104 {
105     struct BDRVCURLState *s;
106     CURLAIOCB *acb[CURL_NUM_ACB];
107     CURL *curl;
108     QLIST_HEAD(, CURLSocket) sockets;
109     char *orig_buf;
110     uint64_t buf_start;
111     size_t buf_off;
112     size_t buf_len;
113     char range[128];
114     char errmsg[CURL_ERROR_SIZE];
115     char in_use;
116 } CURLState;
117 
118 typedef struct BDRVCURLState {
119     CURLM *multi;
120     QEMUTimer timer;
121     uint64_t len;
122     CURLState states[CURL_NUM_STATES];
123     char *url;
124     size_t readahead_size;
125     bool sslverify;
126     uint64_t timeout;
127     char *cookie;
128     bool accept_range;
129     AioContext *aio_context;
130     QemuMutex mutex;
131     CoQueue free_state_waitq;
132     char *username;
133     char *password;
134     char *proxyusername;
135     char *proxypassword;
136 } BDRVCURLState;
137 
138 static void curl_clean_state(CURLState *s);
139 static void curl_multi_do(void *arg);
140 static void curl_multi_read(void *arg);
141 
142 #ifdef NEED_CURL_TIMER_CALLBACK
143 /* Called from curl_multi_do_locked, with s->mutex held.  */
144 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
145 {
146     BDRVCURLState *s = opaque;
147 
148     trace_curl_timer_cb(timeout_ms);
149     if (timeout_ms == -1) {
150         timer_del(&s->timer);
151     } else {
152         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
153         timer_mod(&s->timer,
154                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
155     }
156     return 0;
157 }
158 #endif
159 
160 /* Called from curl_multi_do_locked, with s->mutex held.  */
161 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
162                         void *userp, void *sp)
163 {
164     BDRVCURLState *s;
165     CURLState *state = NULL;
166     CURLSocket *socket;
167 
168     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
169     s = state->s;
170 
171     QLIST_FOREACH(socket, &state->sockets, next) {
172         if (socket->fd == fd) {
173             if (action == CURL_POLL_REMOVE) {
174                 QLIST_REMOVE(socket, next);
175                 g_free(socket);
176             }
177             break;
178         }
179     }
180     if (!socket) {
181         socket = g_new0(CURLSocket, 1);
182         socket->fd = fd;
183         QLIST_INSERT_HEAD(&state->sockets, socket, next);
184     }
185     socket = NULL;
186 
187     trace_curl_sock_cb(action, (int)fd);
188     switch (action) {
189         case CURL_POLL_IN:
190             aio_set_fd_handler(s->aio_context, fd, false,
191                                curl_multi_read, NULL, NULL, state);
192             break;
193         case CURL_POLL_OUT:
194             aio_set_fd_handler(s->aio_context, fd, false,
195                                NULL, curl_multi_do, NULL, state);
196             break;
197         case CURL_POLL_INOUT:
198             aio_set_fd_handler(s->aio_context, fd, false,
199                                curl_multi_read, curl_multi_do, NULL, state);
200             break;
201         case CURL_POLL_REMOVE:
202             aio_set_fd_handler(s->aio_context, fd, false,
203                                NULL, NULL, NULL, NULL);
204             break;
205     }
206 
207     return 0;
208 }
209 
210 /* Called from curl_multi_do_locked, with s->mutex held.  */
211 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
212 {
213     BDRVCURLState *s = opaque;
214     size_t realsize = size * nmemb;
215     const char *accept_line = "Accept-Ranges: bytes";
216 
217     if (realsize >= strlen(accept_line)
218         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
219         s->accept_range = true;
220     }
221 
222     return realsize;
223 }
224 
225 /* Called from curl_multi_do_locked, with s->mutex held.  */
226 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
227 {
228     CURLState *s = ((CURLState*)opaque);
229     size_t realsize = size * nmemb;
230     int i;
231 
232     trace_curl_read_cb(realsize);
233 
234     if (!s || !s->orig_buf) {
235         goto read_end;
236     }
237 
238     if (s->buf_off >= s->buf_len) {
239         /* buffer full, read nothing */
240         goto read_end;
241     }
242     realsize = MIN(realsize, s->buf_len - s->buf_off);
243     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
244     s->buf_off += realsize;
245 
246     for(i=0; i<CURL_NUM_ACB; i++) {
247         CURLAIOCB *acb = s->acb[i];
248 
249         if (!acb)
250             continue;
251 
252         if ((s->buf_off >= acb->end)) {
253             size_t request_length = acb->bytes;
254 
255             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
256                                 acb->end - acb->start);
257 
258             if (acb->end - acb->start < request_length) {
259                 size_t offset = acb->end - acb->start;
260                 qemu_iovec_memset(acb->qiov, offset, 0,
261                                   request_length - offset);
262             }
263 
264             acb->ret = 0;
265             s->acb[i] = NULL;
266             qemu_mutex_unlock(&s->s->mutex);
267             aio_co_wake(acb->co);
268             qemu_mutex_lock(&s->s->mutex);
269         }
270     }
271 
272 read_end:
273     /* curl will error out if we do not return this value */
274     return size * nmemb;
275 }
276 
277 /* Called with s->mutex held.  */
278 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
279                           CURLAIOCB *acb)
280 {
281     int i;
282     uint64_t end = start + len;
283     uint64_t clamped_end = MIN(end, s->len);
284     uint64_t clamped_len = clamped_end - start;
285 
286     for (i=0; i<CURL_NUM_STATES; i++) {
287         CURLState *state = &s->states[i];
288         uint64_t buf_end = (state->buf_start + state->buf_off);
289         uint64_t buf_fend = (state->buf_start + state->buf_len);
290 
291         if (!state->orig_buf)
292             continue;
293         if (!state->buf_off)
294             continue;
295 
296         // Does the existing buffer cover our section?
297         if ((start >= state->buf_start) &&
298             (start <= buf_end) &&
299             (clamped_end >= state->buf_start) &&
300             (clamped_end <= buf_end))
301         {
302             char *buf = state->orig_buf + (start - state->buf_start);
303 
304             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
305             if (clamped_len < len) {
306                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
307             }
308             acb->ret = 0;
309             return true;
310         }
311 
312         // Wait for unfinished chunks
313         if (state->in_use &&
314             (start >= state->buf_start) &&
315             (start <= buf_fend) &&
316             (clamped_end >= state->buf_start) &&
317             (clamped_end <= buf_fend))
318         {
319             int j;
320 
321             acb->start = start - state->buf_start;
322             acb->end = acb->start + clamped_len;
323 
324             for (j=0; j<CURL_NUM_ACB; j++) {
325                 if (!state->acb[j]) {
326                     state->acb[j] = acb;
327                     return true;
328                 }
329             }
330         }
331     }
332 
333     return false;
334 }
335 
336 /* Called with s->mutex held.  */
337 static void curl_multi_check_completion(BDRVCURLState *s)
338 {
339     int msgs_in_queue;
340 
341     /* Try to find done transfers, so we can free the easy
342      * handle again. */
343     for (;;) {
344         CURLMsg *msg;
345         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
346 
347         /* Quit when there are no more completions */
348         if (!msg)
349             break;
350 
351         if (msg->msg == CURLMSG_DONE) {
352             CURLState *state = NULL;
353             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
354                               (char **)&state);
355 
356             /* ACBs for successful messages get completed in curl_read_cb */
357             if (msg->data.result != CURLE_OK) {
358                 int i;
359                 static int errcount = 100;
360 
361                 /* Don't lose the original error message from curl, since
362                  * it contains extra data.
363                  */
364                 if (errcount > 0) {
365                     error_report("curl: %s", state->errmsg);
366                     if (--errcount == 0) {
367                         error_report("curl: further errors suppressed");
368                     }
369                 }
370 
371                 for (i = 0; i < CURL_NUM_ACB; i++) {
372                     CURLAIOCB *acb = state->acb[i];
373 
374                     if (acb == NULL) {
375                         continue;
376                     }
377 
378                     acb->ret = -EIO;
379                     state->acb[i] = NULL;
380                     qemu_mutex_unlock(&s->mutex);
381                     aio_co_wake(acb->co);
382                     qemu_mutex_lock(&s->mutex);
383                 }
384             }
385 
386             curl_clean_state(state);
387             break;
388         }
389     }
390 }
391 
392 /* Called with s->mutex held.  */
393 static void curl_multi_do_locked(CURLState *s)
394 {
395     CURLSocket *socket, *next_socket;
396     int running;
397     int r;
398 
399     if (!s->s->multi) {
400         return;
401     }
402 
403     /* Need to use _SAFE because curl_multi_socket_action() may trigger
404      * curl_sock_cb() which might modify this list */
405     QLIST_FOREACH_SAFE(socket, &s->sockets, next, next_socket) {
406         do {
407             r = curl_multi_socket_action(s->s->multi, socket->fd, 0, &running);
408         } while (r == CURLM_CALL_MULTI_PERFORM);
409     }
410 }
411 
412 static void curl_multi_do(void *arg)
413 {
414     CURLState *s = (CURLState *)arg;
415 
416     qemu_mutex_lock(&s->s->mutex);
417     curl_multi_do_locked(s);
418     qemu_mutex_unlock(&s->s->mutex);
419 }
420 
421 static void curl_multi_read(void *arg)
422 {
423     CURLState *s = (CURLState *)arg;
424 
425     qemu_mutex_lock(&s->s->mutex);
426     curl_multi_do_locked(s);
427     curl_multi_check_completion(s->s);
428     qemu_mutex_unlock(&s->s->mutex);
429 }
430 
431 static void curl_multi_timeout_do(void *arg)
432 {
433 #ifdef NEED_CURL_TIMER_CALLBACK
434     BDRVCURLState *s = (BDRVCURLState *)arg;
435     int running;
436 
437     if (!s->multi) {
438         return;
439     }
440 
441     qemu_mutex_lock(&s->mutex);
442     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
443 
444     curl_multi_check_completion(s);
445     qemu_mutex_unlock(&s->mutex);
446 #else
447     abort();
448 #endif
449 }
450 
451 /* Called with s->mutex held.  */
452 static CURLState *curl_find_state(BDRVCURLState *s)
453 {
454     CURLState *state = NULL;
455     int i;
456 
457     for (i = 0; i < CURL_NUM_STATES; i++) {
458         if (!s->states[i].in_use) {
459             state = &s->states[i];
460             state->in_use = 1;
461             break;
462         }
463     }
464     return state;
465 }
466 
467 static int curl_init_state(BDRVCURLState *s, CURLState *state)
468 {
469     if (!state->curl) {
470         state->curl = curl_easy_init();
471         if (!state->curl) {
472             return -EIO;
473         }
474         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
475         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
476                          (long) s->sslverify);
477         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
478                          s->sslverify ? 2L : 0L);
479         if (s->cookie) {
480             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
481         }
482         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
483         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
484                          (void *)curl_read_cb);
485         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
486         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
487         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
488         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
489         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
490         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
491         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
492 
493         if (s->username) {
494             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
495         }
496         if (s->password) {
497             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
498         }
499         if (s->proxyusername) {
500             curl_easy_setopt(state->curl,
501                              CURLOPT_PROXYUSERNAME, s->proxyusername);
502         }
503         if (s->proxypassword) {
504             curl_easy_setopt(state->curl,
505                              CURLOPT_PROXYPASSWORD, s->proxypassword);
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.
513          */
514 #if LIBCURL_VERSION_NUM >= 0x071304
515         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
516         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
517 #endif
518 
519 #ifdef DEBUG_VERBOSE
520         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
521 #endif
522     }
523 
524     QLIST_INIT(&state->sockets);
525     state->s = s;
526 
527     return 0;
528 }
529 
530 /* Called with s->mutex held.  */
531 static void curl_clean_state(CURLState *s)
532 {
533     int j;
534     for (j = 0; j < CURL_NUM_ACB; j++) {
535         assert(!s->acb[j]);
536     }
537 
538     if (s->s->multi)
539         curl_multi_remove_handle(s->s->multi, s->curl);
540 
541     while (!QLIST_EMPTY(&s->sockets)) {
542         CURLSocket *socket = QLIST_FIRST(&s->sockets);
543 
544         QLIST_REMOVE(socket, next);
545         g_free(socket);
546     }
547 
548     s->in_use = 0;
549 
550     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
551 }
552 
553 static void curl_parse_filename(const char *filename, QDict *options,
554                                 Error **errp)
555 {
556     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
557 }
558 
559 static void curl_detach_aio_context(BlockDriverState *bs)
560 {
561     BDRVCURLState *s = bs->opaque;
562     int i;
563 
564     qemu_mutex_lock(&s->mutex);
565     for (i = 0; i < CURL_NUM_STATES; i++) {
566         if (s->states[i].in_use) {
567             curl_clean_state(&s->states[i]);
568         }
569         if (s->states[i].curl) {
570             curl_easy_cleanup(s->states[i].curl);
571             s->states[i].curl = NULL;
572         }
573         g_free(s->states[i].orig_buf);
574         s->states[i].orig_buf = NULL;
575     }
576     if (s->multi) {
577         curl_multi_cleanup(s->multi);
578         s->multi = NULL;
579     }
580     qemu_mutex_unlock(&s->mutex);
581 
582     timer_del(&s->timer);
583 }
584 
585 static void curl_attach_aio_context(BlockDriverState *bs,
586                                     AioContext *new_context)
587 {
588     BDRVCURLState *s = bs->opaque;
589 
590     aio_timer_init(new_context, &s->timer,
591                    QEMU_CLOCK_REALTIME, SCALE_NS,
592                    curl_multi_timeout_do, s);
593 
594     assert(!s->multi);
595     s->multi = curl_multi_init();
596     s->aio_context = new_context;
597     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
598 #ifdef NEED_CURL_TIMER_CALLBACK
599     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
600     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
601 #endif
602 }
603 
604 static QemuOptsList runtime_opts = {
605     .name = "curl",
606     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
607     .desc = {
608         {
609             .name = CURL_BLOCK_OPT_URL,
610             .type = QEMU_OPT_STRING,
611             .help = "URL to open",
612         },
613         {
614             .name = CURL_BLOCK_OPT_READAHEAD,
615             .type = QEMU_OPT_SIZE,
616             .help = "Readahead size",
617         },
618         {
619             .name = CURL_BLOCK_OPT_SSLVERIFY,
620             .type = QEMU_OPT_BOOL,
621             .help = "Verify SSL certificate"
622         },
623         {
624             .name = CURL_BLOCK_OPT_TIMEOUT,
625             .type = QEMU_OPT_NUMBER,
626             .help = "Curl timeout"
627         },
628         {
629             .name = CURL_BLOCK_OPT_COOKIE,
630             .type = QEMU_OPT_STRING,
631             .help = "Pass the cookie or list of cookies with each request"
632         },
633         {
634             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
635             .type = QEMU_OPT_STRING,
636             .help = "ID of secret used as cookie passed with each request"
637         },
638         {
639             .name = CURL_BLOCK_OPT_USERNAME,
640             .type = QEMU_OPT_STRING,
641             .help = "Username for HTTP auth"
642         },
643         {
644             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
645             .type = QEMU_OPT_STRING,
646             .help = "ID of secret used as password for HTTP auth",
647         },
648         {
649             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
650             .type = QEMU_OPT_STRING,
651             .help = "Username for HTTP proxy auth"
652         },
653         {
654             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
655             .type = QEMU_OPT_STRING,
656             .help = "ID of secret used as password for HTTP proxy auth",
657         },
658         { /* end of list */ }
659     },
660 };
661 
662 
663 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
664                      Error **errp)
665 {
666     BDRVCURLState *s = bs->opaque;
667     CURLState *state = NULL;
668     QemuOpts *opts;
669     Error *local_err = NULL;
670     const char *file;
671     const char *cookie;
672     const char *cookie_secret;
673     double d;
674     const char *secretid;
675     const char *protocol_delimiter;
676     int ret;
677 
678     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
679                                     errp);
680     if (ret < 0) {
681         return ret;
682     }
683 
684     if (!libcurl_initialized) {
685         ret = curl_global_init(CURL_GLOBAL_ALL);
686         if (ret) {
687             error_setg(errp, "libcurl initialization failed with %d", ret);
688             return -EIO;
689         }
690         libcurl_initialized = true;
691     }
692 
693     qemu_mutex_init(&s->mutex);
694     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
695     qemu_opts_absorb_qdict(opts, options, &local_err);
696     if (local_err) {
697         error_propagate(errp, local_err);
698         goto out_noclean;
699     }
700 
701     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
702                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
703     if ((s->readahead_size & 0x1ff) != 0) {
704         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
705                    s->readahead_size);
706         goto out_noclean;
707     }
708 
709     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
710                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
711     if (s->timeout > CURL_TIMEOUT_MAX) {
712         error_setg(errp, "timeout parameter is too large or negative");
713         goto out_noclean;
714     }
715 
716     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
717                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
718 
719     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
720     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
721 
722     if (cookie && cookie_secret) {
723         error_setg(errp,
724                    "curl driver cannot handle both cookie and cookie secret");
725         goto out_noclean;
726     }
727 
728     if (cookie_secret) {
729         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
730         if (!s->cookie) {
731             goto out_noclean;
732         }
733     } else {
734         s->cookie = g_strdup(cookie);
735     }
736 
737     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
738     if (file == NULL) {
739         error_setg(errp, "curl block driver requires an 'url' option");
740         goto out_noclean;
741     }
742 
743     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
744         !strstart(protocol_delimiter, "://", NULL))
745     {
746         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
747                    "start with '%s://')", bs->drv->protocol_name, file,
748                    bs->drv->protocol_name);
749         goto out_noclean;
750     }
751 
752     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
753     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
754 
755     if (secretid) {
756         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
757         if (!s->password) {
758             goto out_noclean;
759         }
760     }
761 
762     s->proxyusername = g_strdup(
763         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
764     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
765     if (secretid) {
766         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
767         if (!s->proxypassword) {
768             goto out_noclean;
769         }
770     }
771 
772     trace_curl_open(file);
773     qemu_co_queue_init(&s->free_state_waitq);
774     s->aio_context = bdrv_get_aio_context(bs);
775     s->url = g_strdup(file);
776     qemu_mutex_lock(&s->mutex);
777     state = curl_find_state(s);
778     qemu_mutex_unlock(&s->mutex);
779     if (!state) {
780         goto out_noclean;
781     }
782 
783     // Get file size
784 
785     if (curl_init_state(s, state) < 0) {
786         goto out;
787     }
788 
789     s->accept_range = false;
790     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
791     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
792                      curl_header_cb);
793     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
794     if (curl_easy_perform(state->curl))
795         goto out;
796     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
797         goto out;
798     }
799     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
800      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
801      * known and zero if it is really zero-length file. */
802 #if LIBCURL_VERSION_NUM >= 0x071304
803     if (d < 0) {
804         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
805                 "Server didn't report file size.");
806         goto out;
807     }
808 #else
809     if (d <= 0) {
810         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
811                 "Unknown file size or zero-length file.");
812         goto out;
813     }
814 #endif
815 
816     s->len = d;
817 
818     if ((!strncasecmp(s->url, "http://", strlen("http://"))
819         || !strncasecmp(s->url, "https://", strlen("https://")))
820         && !s->accept_range) {
821         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
822                 "Server does not support 'range' (byte ranges).");
823         goto out;
824     }
825     trace_curl_open_size(s->len);
826 
827     qemu_mutex_lock(&s->mutex);
828     curl_clean_state(state);
829     qemu_mutex_unlock(&s->mutex);
830     curl_easy_cleanup(state->curl);
831     state->curl = NULL;
832 
833     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
834 
835     qemu_opts_del(opts);
836     return 0;
837 
838 out:
839     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
840     curl_easy_cleanup(state->curl);
841     state->curl = NULL;
842 out_noclean:
843     qemu_mutex_destroy(&s->mutex);
844     g_free(s->cookie);
845     g_free(s->url);
846     g_free(s->username);
847     g_free(s->proxyusername);
848     g_free(s->proxypassword);
849     qemu_opts_del(opts);
850     return -EINVAL;
851 }
852 
853 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
854 {
855     CURLState *state;
856     int running;
857 
858     BDRVCURLState *s = bs->opaque;
859 
860     uint64_t start = acb->offset;
861     uint64_t end;
862 
863     qemu_mutex_lock(&s->mutex);
864 
865     // In case we have the requested data already (e.g. read-ahead),
866     // we can just call the callback and be done.
867     if (curl_find_buf(s, start, acb->bytes, acb)) {
868         goto out;
869     }
870 
871     // No cache found, so let's start a new request
872     for (;;) {
873         state = curl_find_state(s);
874         if (state) {
875             break;
876         }
877         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
878     }
879 
880     if (curl_init_state(s, state) < 0) {
881         curl_clean_state(state);
882         acb->ret = -EIO;
883         goto out;
884     }
885 
886     acb->start = 0;
887     acb->end = MIN(acb->bytes, s->len - start);
888 
889     state->buf_off = 0;
890     g_free(state->orig_buf);
891     state->buf_start = start;
892     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
893     end = start + state->buf_len - 1;
894     state->orig_buf = g_try_malloc(state->buf_len);
895     if (state->buf_len && state->orig_buf == NULL) {
896         curl_clean_state(state);
897         acb->ret = -ENOMEM;
898         goto out;
899     }
900     state->acb[0] = acb;
901 
902     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
903     trace_curl_setup_preadv(acb->bytes, start, state->range);
904     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
905 
906     curl_multi_add_handle(s->multi, state->curl);
907 
908     /* Tell curl it needs to kick things off */
909     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
910 
911 out:
912     qemu_mutex_unlock(&s->mutex);
913 }
914 
915 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
916         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
917 {
918     CURLAIOCB acb = {
919         .co = qemu_coroutine_self(),
920         .ret = -EINPROGRESS,
921         .qiov = qiov,
922         .offset = offset,
923         .bytes = bytes
924     };
925 
926     curl_setup_preadv(bs, &acb);
927     while (acb.ret == -EINPROGRESS) {
928         qemu_coroutine_yield();
929     }
930     return acb.ret;
931 }
932 
933 static void curl_close(BlockDriverState *bs)
934 {
935     BDRVCURLState *s = bs->opaque;
936 
937     trace_curl_close();
938     curl_detach_aio_context(bs);
939     qemu_mutex_destroy(&s->mutex);
940 
941     g_free(s->cookie);
942     g_free(s->url);
943     g_free(s->username);
944     g_free(s->proxyusername);
945     g_free(s->proxypassword);
946 }
947 
948 static int64_t curl_getlength(BlockDriverState *bs)
949 {
950     BDRVCURLState *s = bs->opaque;
951     return s->len;
952 }
953 
954 static void curl_refresh_filename(BlockDriverState *bs)
955 {
956     BDRVCURLState *s = bs->opaque;
957 
958     /* "readahead" and "timeout" do not change the guest-visible data,
959      * so ignore them */
960     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
961         s->cookie || s->username || s->password || s->proxyusername ||
962         s->proxypassword)
963     {
964         return;
965     }
966 
967     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
968 }
969 
970 
971 static const char *const curl_strong_runtime_opts[] = {
972     CURL_BLOCK_OPT_URL,
973     CURL_BLOCK_OPT_SSLVERIFY,
974     CURL_BLOCK_OPT_COOKIE,
975     CURL_BLOCK_OPT_COOKIE_SECRET,
976     CURL_BLOCK_OPT_USERNAME,
977     CURL_BLOCK_OPT_PASSWORD_SECRET,
978     CURL_BLOCK_OPT_PROXY_USERNAME,
979     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
980 
981     NULL
982 };
983 
984 static BlockDriver bdrv_http = {
985     .format_name                = "http",
986     .protocol_name              = "http",
987 
988     .instance_size              = sizeof(BDRVCURLState),
989     .bdrv_parse_filename        = curl_parse_filename,
990     .bdrv_file_open             = curl_open,
991     .bdrv_close                 = curl_close,
992     .bdrv_getlength             = curl_getlength,
993 
994     .bdrv_co_preadv             = curl_co_preadv,
995 
996     .bdrv_detach_aio_context    = curl_detach_aio_context,
997     .bdrv_attach_aio_context    = curl_attach_aio_context,
998 
999     .bdrv_refresh_filename      = curl_refresh_filename,
1000     .strong_runtime_opts        = curl_strong_runtime_opts,
1001 };
1002 
1003 static BlockDriver bdrv_https = {
1004     .format_name                = "https",
1005     .protocol_name              = "https",
1006 
1007     .instance_size              = sizeof(BDRVCURLState),
1008     .bdrv_parse_filename        = curl_parse_filename,
1009     .bdrv_file_open             = curl_open,
1010     .bdrv_close                 = curl_close,
1011     .bdrv_getlength             = curl_getlength,
1012 
1013     .bdrv_co_preadv             = curl_co_preadv,
1014 
1015     .bdrv_detach_aio_context    = curl_detach_aio_context,
1016     .bdrv_attach_aio_context    = curl_attach_aio_context,
1017 
1018     .bdrv_refresh_filename      = curl_refresh_filename,
1019     .strong_runtime_opts        = curl_strong_runtime_opts,
1020 };
1021 
1022 static BlockDriver bdrv_ftp = {
1023     .format_name                = "ftp",
1024     .protocol_name              = "ftp",
1025 
1026     .instance_size              = sizeof(BDRVCURLState),
1027     .bdrv_parse_filename        = curl_parse_filename,
1028     .bdrv_file_open             = curl_open,
1029     .bdrv_close                 = curl_close,
1030     .bdrv_getlength             = curl_getlength,
1031 
1032     .bdrv_co_preadv             = curl_co_preadv,
1033 
1034     .bdrv_detach_aio_context    = curl_detach_aio_context,
1035     .bdrv_attach_aio_context    = curl_attach_aio_context,
1036 
1037     .bdrv_refresh_filename      = curl_refresh_filename,
1038     .strong_runtime_opts        = curl_strong_runtime_opts,
1039 };
1040 
1041 static BlockDriver bdrv_ftps = {
1042     .format_name                = "ftps",
1043     .protocol_name              = "ftps",
1044 
1045     .instance_size              = sizeof(BDRVCURLState),
1046     .bdrv_parse_filename        = curl_parse_filename,
1047     .bdrv_file_open             = curl_open,
1048     .bdrv_close                 = curl_close,
1049     .bdrv_getlength             = curl_getlength,
1050 
1051     .bdrv_co_preadv             = curl_co_preadv,
1052 
1053     .bdrv_detach_aio_context    = curl_detach_aio_context,
1054     .bdrv_attach_aio_context    = curl_attach_aio_context,
1055 
1056     .bdrv_refresh_filename      = curl_refresh_filename,
1057     .strong_runtime_opts        = curl_strong_runtime_opts,
1058 };
1059 
1060 static void curl_block_init(void)
1061 {
1062     bdrv_register(&bdrv_http);
1063     bdrv_register(&bdrv_https);
1064     bdrv_register(&bdrv_ftp);
1065     bdrv_register(&bdrv_ftps);
1066 }
1067 
1068 block_init(curl_block_init);
1069