xref: /openbmc/qemu/block/curl.c (revision f764718d)
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 #include "qemu/osdep.h"
25 #include "qapi/error.h"
26 #include "qemu-common.h"
27 #include "qemu/error-report.h"
28 #include "block/block_int.h"
29 #include "qapi/qmp/qbool.h"
30 #include "qapi/qmp/qstring.h"
31 #include "crypto/secret.h"
32 #include <curl/curl.h>
33 #include "qemu/cutils.h"
34 
35 // #define DEBUG_CURL
36 // #define DEBUG_VERBOSE
37 
38 #ifdef DEBUG_CURL
39 #define DEBUG_CURL_PRINT 1
40 #else
41 #define DEBUG_CURL_PRINT 0
42 #endif
43 #define DPRINTF(fmt, ...)                                            \
44     do {                                                             \
45         if (DEBUG_CURL_PRINT) {                                      \
46             fprintf(stderr, fmt, ## __VA_ARGS__);                    \
47         }                                                            \
48     } while (0)
49 
50 #if LIBCURL_VERSION_NUM >= 0x071000
51 /* The multi interface timer callback was introduced in 7.16.0 */
52 #define NEED_CURL_TIMER_CALLBACK
53 #define HAVE_SOCKET_ACTION
54 #endif
55 
56 #ifndef HAVE_SOCKET_ACTION
57 /* If curl_multi_socket_action isn't available, define it statically here in
58  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
59  * less efficient but still safe. */
60 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
61                                             curl_socket_t sockfd,
62                                             int ev_bitmask,
63                                             int *running_handles)
64 {
65     return curl_multi_socket(multi_handle, sockfd, running_handles);
66 }
67 #define curl_multi_socket_action __curl_multi_socket_action
68 #endif
69 
70 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
71                    CURLPROTO_FTP | CURLPROTO_FTPS)
72 
73 #define CURL_NUM_STATES 8
74 #define CURL_NUM_ACB    8
75 #define READ_AHEAD_DEFAULT (256 * 1024)
76 #define CURL_TIMEOUT_DEFAULT 5
77 #define CURL_TIMEOUT_MAX 10000
78 
79 #define CURL_BLOCK_OPT_URL       "url"
80 #define CURL_BLOCK_OPT_READAHEAD "readahead"
81 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
82 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
83 #define CURL_BLOCK_OPT_COOKIE    "cookie"
84 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
85 #define CURL_BLOCK_OPT_USERNAME "username"
86 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
87 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
88 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
89 
90 struct BDRVCURLState;
91 
92 static bool libcurl_initialized;
93 
94 typedef struct CURLAIOCB {
95     Coroutine *co;
96     QEMUIOVector *qiov;
97 
98     uint64_t offset;
99     uint64_t bytes;
100     int ret;
101 
102     size_t start;
103     size_t end;
104 
105     QSIMPLEQ_ENTRY(CURLAIOCB) next;
106 } CURLAIOCB;
107 
108 typedef struct CURLSocket {
109     int fd;
110     QLIST_ENTRY(CURLSocket) next;
111 } CURLSocket;
112 
113 typedef struct CURLState
114 {
115     struct BDRVCURLState *s;
116     CURLAIOCB *acb[CURL_NUM_ACB];
117     CURL *curl;
118     QLIST_HEAD(, CURLSocket) sockets;
119     char *orig_buf;
120     uint64_t buf_start;
121     size_t buf_off;
122     size_t buf_len;
123     char range[128];
124     char errmsg[CURL_ERROR_SIZE];
125     char in_use;
126 } CURLState;
127 
128 typedef struct BDRVCURLState {
129     CURLM *multi;
130     QEMUTimer timer;
131     uint64_t len;
132     CURLState states[CURL_NUM_STATES];
133     char *url;
134     size_t readahead_size;
135     bool sslverify;
136     uint64_t timeout;
137     char *cookie;
138     bool accept_range;
139     AioContext *aio_context;
140     QemuMutex mutex;
141     QSIMPLEQ_HEAD(, CURLAIOCB) free_state_waitq;
142     char *username;
143     char *password;
144     char *proxyusername;
145     char *proxypassword;
146 } BDRVCURLState;
147 
148 static void curl_clean_state(CURLState *s);
149 static void curl_multi_do(void *arg);
150 static void curl_multi_read(void *arg);
151 
152 #ifdef NEED_CURL_TIMER_CALLBACK
153 /* Called from curl_multi_do_locked, with s->mutex held.  */
154 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
155 {
156     BDRVCURLState *s = opaque;
157 
158     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
159     if (timeout_ms == -1) {
160         timer_del(&s->timer);
161     } else {
162         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
163         timer_mod(&s->timer,
164                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
165     }
166     return 0;
167 }
168 #endif
169 
170 /* Called from curl_multi_do_locked, with s->mutex held.  */
171 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
172                         void *userp, void *sp)
173 {
174     BDRVCURLState *s;
175     CURLState *state = NULL;
176     CURLSocket *socket;
177 
178     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
179     s = state->s;
180 
181     QLIST_FOREACH(socket, &state->sockets, next) {
182         if (socket->fd == fd) {
183             if (action == CURL_POLL_REMOVE) {
184                 QLIST_REMOVE(socket, next);
185                 g_free(socket);
186             }
187             break;
188         }
189     }
190     if (!socket) {
191         socket = g_new0(CURLSocket, 1);
192         socket->fd = fd;
193         QLIST_INSERT_HEAD(&state->sockets, socket, next);
194     }
195     socket = NULL;
196 
197     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, (int)fd);
198     switch (action) {
199         case CURL_POLL_IN:
200             aio_set_fd_handler(s->aio_context, fd, false,
201                                curl_multi_read, NULL, NULL, state);
202             break;
203         case CURL_POLL_OUT:
204             aio_set_fd_handler(s->aio_context, fd, false,
205                                NULL, curl_multi_do, NULL, state);
206             break;
207         case CURL_POLL_INOUT:
208             aio_set_fd_handler(s->aio_context, fd, false,
209                                curl_multi_read, curl_multi_do, NULL, state);
210             break;
211         case CURL_POLL_REMOVE:
212             aio_set_fd_handler(s->aio_context, fd, false,
213                                NULL, NULL, NULL, NULL);
214             break;
215     }
216 
217     return 0;
218 }
219 
220 /* Called from curl_multi_do_locked, with s->mutex held.  */
221 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
222 {
223     BDRVCURLState *s = opaque;
224     size_t realsize = size * nmemb;
225     const char *accept_line = "Accept-Ranges: bytes";
226 
227     if (realsize >= strlen(accept_line)
228         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
229         s->accept_range = true;
230     }
231 
232     return realsize;
233 }
234 
235 /* Called from curl_multi_do_locked, with s->mutex held.  */
236 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
237 {
238     CURLState *s = ((CURLState*)opaque);
239     size_t realsize = size * nmemb;
240     int i;
241 
242     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
243 
244     if (!s || !s->orig_buf) {
245         goto read_end;
246     }
247 
248     if (s->buf_off >= s->buf_len) {
249         /* buffer full, read nothing */
250         goto read_end;
251     }
252     realsize = MIN(realsize, s->buf_len - s->buf_off);
253     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
254     s->buf_off += realsize;
255 
256     for(i=0; i<CURL_NUM_ACB; i++) {
257         CURLAIOCB *acb = s->acb[i];
258 
259         if (!acb)
260             continue;
261 
262         if ((s->buf_off >= acb->end)) {
263             size_t request_length = acb->bytes;
264 
265             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
266                                 acb->end - acb->start);
267 
268             if (acb->end - acb->start < request_length) {
269                 size_t offset = acb->end - acb->start;
270                 qemu_iovec_memset(acb->qiov, offset, 0,
271                                   request_length - offset);
272             }
273 
274             acb->ret = 0;
275             s->acb[i] = NULL;
276             qemu_mutex_unlock(&s->s->mutex);
277             aio_co_wake(acb->co);
278             qemu_mutex_lock(&s->s->mutex);
279         }
280     }
281 
282 read_end:
283     /* curl will error out if we do not return this value */
284     return size * nmemb;
285 }
286 
287 /* Called with s->mutex held.  */
288 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
289                           CURLAIOCB *acb)
290 {
291     int i;
292     uint64_t end = start + len;
293     uint64_t clamped_end = MIN(end, s->len);
294     uint64_t clamped_len = clamped_end - start;
295 
296     for (i=0; i<CURL_NUM_STATES; i++) {
297         CURLState *state = &s->states[i];
298         uint64_t buf_end = (state->buf_start + state->buf_off);
299         uint64_t buf_fend = (state->buf_start + state->buf_len);
300 
301         if (!state->orig_buf)
302             continue;
303         if (!state->buf_off)
304             continue;
305 
306         // Does the existing buffer cover our section?
307         if ((start >= state->buf_start) &&
308             (start <= buf_end) &&
309             (clamped_end >= state->buf_start) &&
310             (clamped_end <= buf_end))
311         {
312             char *buf = state->orig_buf + (start - state->buf_start);
313 
314             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
315             if (clamped_len < len) {
316                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
317             }
318             acb->ret = 0;
319             return true;
320         }
321 
322         // Wait for unfinished chunks
323         if (state->in_use &&
324             (start >= state->buf_start) &&
325             (start <= buf_fend) &&
326             (clamped_end >= state->buf_start) &&
327             (clamped_end <= buf_fend))
328         {
329             int j;
330 
331             acb->start = start - state->buf_start;
332             acb->end = acb->start + clamped_len;
333 
334             for (j=0; j<CURL_NUM_ACB; j++) {
335                 if (!state->acb[j]) {
336                     state->acb[j] = acb;
337                     return true;
338                 }
339             }
340         }
341     }
342 
343     return false;
344 }
345 
346 /* Called with s->mutex held.  */
347 static void curl_multi_check_completion(BDRVCURLState *s)
348 {
349     int msgs_in_queue;
350 
351     /* Try to find done transfers, so we can free the easy
352      * handle again. */
353     for (;;) {
354         CURLMsg *msg;
355         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
356 
357         /* Quit when there are no more completions */
358         if (!msg)
359             break;
360 
361         if (msg->msg == CURLMSG_DONE) {
362             CURLState *state = NULL;
363             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
364                               (char **)&state);
365 
366             /* ACBs for successful messages get completed in curl_read_cb */
367             if (msg->data.result != CURLE_OK) {
368                 int i;
369                 static int errcount = 100;
370 
371                 /* Don't lose the original error message from curl, since
372                  * it contains extra data.
373                  */
374                 if (errcount > 0) {
375                     error_report("curl: %s", state->errmsg);
376                     if (--errcount == 0) {
377                         error_report("curl: further errors suppressed");
378                     }
379                 }
380 
381                 for (i = 0; i < CURL_NUM_ACB; i++) {
382                     CURLAIOCB *acb = state->acb[i];
383 
384                     if (acb == NULL) {
385                         continue;
386                     }
387 
388                     acb->ret = -EIO;
389                     state->acb[i] = NULL;
390                     qemu_mutex_unlock(&s->mutex);
391                     aio_co_wake(acb->co);
392                     qemu_mutex_lock(&s->mutex);
393                 }
394             }
395 
396             curl_clean_state(state);
397             break;
398         }
399     }
400 }
401 
402 /* Called with s->mutex held.  */
403 static void curl_multi_do_locked(CURLState *s)
404 {
405     CURLSocket *socket, *next_socket;
406     int running;
407     int r;
408 
409     if (!s->s->multi) {
410         return;
411     }
412 
413     /* Need to use _SAFE because curl_multi_socket_action() may trigger
414      * curl_sock_cb() which might modify this list */
415     QLIST_FOREACH_SAFE(socket, &s->sockets, next, next_socket) {
416         do {
417             r = curl_multi_socket_action(s->s->multi, socket->fd, 0, &running);
418         } while (r == CURLM_CALL_MULTI_PERFORM);
419     }
420 }
421 
422 static void curl_multi_do(void *arg)
423 {
424     CURLState *s = (CURLState *)arg;
425 
426     qemu_mutex_lock(&s->s->mutex);
427     curl_multi_do_locked(s);
428     qemu_mutex_unlock(&s->s->mutex);
429 }
430 
431 static void curl_multi_read(void *arg)
432 {
433     CURLState *s = (CURLState *)arg;
434 
435     qemu_mutex_lock(&s->s->mutex);
436     curl_multi_do_locked(s);
437     curl_multi_check_completion(s->s);
438     qemu_mutex_unlock(&s->s->mutex);
439 }
440 
441 static void curl_multi_timeout_do(void *arg)
442 {
443 #ifdef NEED_CURL_TIMER_CALLBACK
444     BDRVCURLState *s = (BDRVCURLState *)arg;
445     int running;
446 
447     if (!s->multi) {
448         return;
449     }
450 
451     qemu_mutex_lock(&s->mutex);
452     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
453 
454     curl_multi_check_completion(s);
455     qemu_mutex_unlock(&s->mutex);
456 #else
457     abort();
458 #endif
459 }
460 
461 /* Called with s->mutex held.  */
462 static CURLState *curl_find_state(BDRVCURLState *s)
463 {
464     CURLState *state = NULL;
465     int i;
466 
467     for (i = 0; i < CURL_NUM_STATES; i++) {
468         if (!s->states[i].in_use) {
469             state = &s->states[i];
470             state->in_use = 1;
471             break;
472         }
473     }
474     return state;
475 }
476 
477 static int curl_init_state(BDRVCURLState *s, CURLState *state)
478 {
479     if (!state->curl) {
480         state->curl = curl_easy_init();
481         if (!state->curl) {
482             return -EIO;
483         }
484         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
485         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
486                          (long) s->sslverify);
487         if (s->cookie) {
488             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
489         }
490         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
491         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
492                          (void *)curl_read_cb);
493         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
494         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
495         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
496         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
497         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
498         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
499         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
500 
501         if (s->username) {
502             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
503         }
504         if (s->password) {
505             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
506         }
507         if (s->proxyusername) {
508             curl_easy_setopt(state->curl,
509                              CURLOPT_PROXYUSERNAME, s->proxyusername);
510         }
511         if (s->proxypassword) {
512             curl_easy_setopt(state->curl,
513                              CURLOPT_PROXYPASSWORD, s->proxypassword);
514         }
515 
516         /* Restrict supported protocols to avoid security issues in the more
517          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
518          * CVE-2013-0249.
519          *
520          * Restricting protocols is only supported from 7.19.4 upwards.
521          */
522 #if LIBCURL_VERSION_NUM >= 0x071304
523         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
524         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
525 #endif
526 
527 #ifdef DEBUG_VERBOSE
528         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
529 #endif
530     }
531 
532     QLIST_INIT(&state->sockets);
533     state->s = s;
534 
535     return 0;
536 }
537 
538 /* Called with s->mutex held.  */
539 static void curl_clean_state(CURLState *s)
540 {
541     CURLAIOCB *next;
542     int j;
543     for (j = 0; j < CURL_NUM_ACB; j++) {
544         assert(!s->acb[j]);
545     }
546 
547     if (s->s->multi)
548         curl_multi_remove_handle(s->s->multi, s->curl);
549 
550     while (!QLIST_EMPTY(&s->sockets)) {
551         CURLSocket *socket = QLIST_FIRST(&s->sockets);
552 
553         QLIST_REMOVE(socket, next);
554         g_free(socket);
555     }
556 
557     s->in_use = 0;
558 
559     next = QSIMPLEQ_FIRST(&s->s->free_state_waitq);
560     if (next) {
561         QSIMPLEQ_REMOVE_HEAD(&s->s->free_state_waitq, next);
562         qemu_mutex_unlock(&s->s->mutex);
563         aio_co_wake(next->co);
564         qemu_mutex_lock(&s->s->mutex);
565     }
566 }
567 
568 static void curl_parse_filename(const char *filename, QDict *options,
569                                 Error **errp)
570 {
571     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
572 }
573 
574 static void curl_detach_aio_context(BlockDriverState *bs)
575 {
576     BDRVCURLState *s = bs->opaque;
577     int i;
578 
579     qemu_mutex_lock(&s->mutex);
580     for (i = 0; i < CURL_NUM_STATES; i++) {
581         if (s->states[i].in_use) {
582             curl_clean_state(&s->states[i]);
583         }
584         if (s->states[i].curl) {
585             curl_easy_cleanup(s->states[i].curl);
586             s->states[i].curl = NULL;
587         }
588         g_free(s->states[i].orig_buf);
589         s->states[i].orig_buf = NULL;
590     }
591     if (s->multi) {
592         curl_multi_cleanup(s->multi);
593         s->multi = NULL;
594     }
595     qemu_mutex_unlock(&s->mutex);
596 
597     timer_del(&s->timer);
598 }
599 
600 static void curl_attach_aio_context(BlockDriverState *bs,
601                                     AioContext *new_context)
602 {
603     BDRVCURLState *s = bs->opaque;
604 
605     aio_timer_init(new_context, &s->timer,
606                    QEMU_CLOCK_REALTIME, SCALE_NS,
607                    curl_multi_timeout_do, s);
608 
609     assert(!s->multi);
610     s->multi = curl_multi_init();
611     s->aio_context = new_context;
612     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
613 #ifdef NEED_CURL_TIMER_CALLBACK
614     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
615     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
616 #endif
617 }
618 
619 static QemuOptsList runtime_opts = {
620     .name = "curl",
621     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
622     .desc = {
623         {
624             .name = CURL_BLOCK_OPT_URL,
625             .type = QEMU_OPT_STRING,
626             .help = "URL to open",
627         },
628         {
629             .name = CURL_BLOCK_OPT_READAHEAD,
630             .type = QEMU_OPT_SIZE,
631             .help = "Readahead size",
632         },
633         {
634             .name = CURL_BLOCK_OPT_SSLVERIFY,
635             .type = QEMU_OPT_BOOL,
636             .help = "Verify SSL certificate"
637         },
638         {
639             .name = CURL_BLOCK_OPT_TIMEOUT,
640             .type = QEMU_OPT_NUMBER,
641             .help = "Curl timeout"
642         },
643         {
644             .name = CURL_BLOCK_OPT_COOKIE,
645             .type = QEMU_OPT_STRING,
646             .help = "Pass the cookie or list of cookies with each request"
647         },
648         {
649             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
650             .type = QEMU_OPT_STRING,
651             .help = "ID of secret used as cookie passed with each request"
652         },
653         {
654             .name = CURL_BLOCK_OPT_USERNAME,
655             .type = QEMU_OPT_STRING,
656             .help = "Username for HTTP auth"
657         },
658         {
659             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
660             .type = QEMU_OPT_STRING,
661             .help = "ID of secret used as password for HTTP auth",
662         },
663         {
664             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
665             .type = QEMU_OPT_STRING,
666             .help = "Username for HTTP proxy auth"
667         },
668         {
669             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
670             .type = QEMU_OPT_STRING,
671             .help = "ID of secret used as password for HTTP proxy auth",
672         },
673         { /* end of list */ }
674     },
675 };
676 
677 
678 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
679                      Error **errp)
680 {
681     BDRVCURLState *s = bs->opaque;
682     CURLState *state = NULL;
683     QemuOpts *opts;
684     Error *local_err = NULL;
685     const char *file;
686     const char *cookie;
687     const char *cookie_secret;
688     double d;
689     const char *secretid;
690     const char *protocol_delimiter;
691     int ret;
692 
693 
694     if (flags & BDRV_O_RDWR) {
695         error_setg(errp, "curl block device does not support writes");
696         return -EROFS;
697     }
698 
699     if (!libcurl_initialized) {
700         ret = curl_global_init(CURL_GLOBAL_ALL);
701         if (ret) {
702             error_setg(errp, "libcurl initialization failed with %d", ret);
703             return -EIO;
704         }
705         libcurl_initialized = true;
706     }
707 
708     qemu_mutex_init(&s->mutex);
709     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
710     qemu_opts_absorb_qdict(opts, options, &local_err);
711     if (local_err) {
712         error_propagate(errp, local_err);
713         goto out_noclean;
714     }
715 
716     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
717                                           READ_AHEAD_DEFAULT);
718     if ((s->readahead_size & 0x1ff) != 0) {
719         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
720                    s->readahead_size);
721         goto out_noclean;
722     }
723 
724     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
725                                      CURL_TIMEOUT_DEFAULT);
726     if (s->timeout > CURL_TIMEOUT_MAX) {
727         error_setg(errp, "timeout parameter is too large or negative");
728         goto out_noclean;
729     }
730 
731     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
732 
733     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
734     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
735 
736     if (cookie && cookie_secret) {
737         error_setg(errp,
738                    "curl driver cannot handle both cookie and cookie secret");
739         goto out_noclean;
740     }
741 
742     if (cookie_secret) {
743         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
744         if (!s->cookie) {
745             goto out_noclean;
746         }
747     } else {
748         s->cookie = g_strdup(cookie);
749     }
750 
751     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
752     if (file == NULL) {
753         error_setg(errp, "curl block driver requires an 'url' option");
754         goto out_noclean;
755     }
756 
757     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
758         !strstart(protocol_delimiter, "://", NULL))
759     {
760         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
761                    "start with '%s://')", bs->drv->protocol_name, file,
762                    bs->drv->protocol_name);
763         goto out_noclean;
764     }
765 
766     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
767     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
768 
769     if (secretid) {
770         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
771         if (!s->password) {
772             goto out_noclean;
773         }
774     }
775 
776     s->proxyusername = g_strdup(
777         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
778     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
779     if (secretid) {
780         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
781         if (!s->proxypassword) {
782             goto out_noclean;
783         }
784     }
785 
786     DPRINTF("CURL: Opening %s\n", file);
787     QSIMPLEQ_INIT(&s->free_state_waitq);
788     s->aio_context = bdrv_get_aio_context(bs);
789     s->url = g_strdup(file);
790     qemu_mutex_lock(&s->mutex);
791     state = curl_find_state(s);
792     qemu_mutex_unlock(&s->mutex);
793     if (!state) {
794         goto out_noclean;
795     }
796 
797     // Get file size
798 
799     if (curl_init_state(s, state) < 0) {
800         goto out;
801     }
802 
803     s->accept_range = false;
804     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
805     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
806                      curl_header_cb);
807     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
808     if (curl_easy_perform(state->curl))
809         goto out;
810     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
811         goto out;
812     }
813     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
814      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
815      * known and zero if it is realy zero-length file. */
816 #if LIBCURL_VERSION_NUM >= 0x071304
817     if (d < 0) {
818         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
819                 "Server didn't report file size.");
820         goto out;
821     }
822 #else
823     if (d <= 0) {
824         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
825                 "Unknown file size or zero-length file.");
826         goto out;
827     }
828 #endif
829 
830     s->len = d;
831 
832     if ((!strncasecmp(s->url, "http://", strlen("http://"))
833         || !strncasecmp(s->url, "https://", strlen("https://")))
834         && !s->accept_range) {
835         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
836                 "Server does not support 'range' (byte ranges).");
837         goto out;
838     }
839     DPRINTF("CURL: Size = %" PRIu64 "\n", s->len);
840 
841     qemu_mutex_lock(&s->mutex);
842     curl_clean_state(state);
843     qemu_mutex_unlock(&s->mutex);
844     curl_easy_cleanup(state->curl);
845     state->curl = NULL;
846 
847     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
848 
849     qemu_opts_del(opts);
850     return 0;
851 
852 out:
853     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
854     curl_easy_cleanup(state->curl);
855     state->curl = NULL;
856 out_noclean:
857     qemu_mutex_destroy(&s->mutex);
858     g_free(s->cookie);
859     g_free(s->url);
860     g_free(s->username);
861     g_free(s->proxyusername);
862     g_free(s->proxypassword);
863     qemu_opts_del(opts);
864     return -EINVAL;
865 }
866 
867 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
868 {
869     CURLState *state;
870     int running;
871 
872     BDRVCURLState *s = bs->opaque;
873 
874     uint64_t start = acb->offset;
875     uint64_t end;
876 
877     qemu_mutex_lock(&s->mutex);
878 
879     // In case we have the requested data already (e.g. read-ahead),
880     // we can just call the callback and be done.
881     if (curl_find_buf(s, start, acb->bytes, acb)) {
882         goto out;
883     }
884 
885     // No cache found, so let's start a new request
886     for (;;) {
887         state = curl_find_state(s);
888         if (state) {
889             break;
890         }
891         QSIMPLEQ_INSERT_TAIL(&s->free_state_waitq, acb, next);
892         qemu_mutex_unlock(&s->mutex);
893         qemu_coroutine_yield();
894         qemu_mutex_lock(&s->mutex);
895     }
896 
897     if (curl_init_state(s, state) < 0) {
898         curl_clean_state(state);
899         acb->ret = -EIO;
900         goto out;
901     }
902 
903     acb->start = 0;
904     acb->end = MIN(acb->bytes, s->len - start);
905 
906     state->buf_off = 0;
907     g_free(state->orig_buf);
908     state->buf_start = start;
909     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
910     end = start + state->buf_len - 1;
911     state->orig_buf = g_try_malloc(state->buf_len);
912     if (state->buf_len && state->orig_buf == NULL) {
913         curl_clean_state(state);
914         acb->ret = -ENOMEM;
915         goto out;
916     }
917     state->acb[0] = acb;
918 
919     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
920     DPRINTF("CURL (AIO): Reading %" PRIu64 " at %" PRIu64 " (%s)\n",
921             acb->bytes, start, state->range);
922     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
923 
924     curl_multi_add_handle(s->multi, state->curl);
925 
926     /* Tell curl it needs to kick things off */
927     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
928 
929 out:
930     qemu_mutex_unlock(&s->mutex);
931 }
932 
933 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
934         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
935 {
936     CURLAIOCB acb = {
937         .co = qemu_coroutine_self(),
938         .ret = -EINPROGRESS,
939         .qiov = qiov,
940         .offset = offset,
941         .bytes = bytes
942     };
943 
944     curl_setup_preadv(bs, &acb);
945     while (acb.ret == -EINPROGRESS) {
946         qemu_coroutine_yield();
947     }
948     return acb.ret;
949 }
950 
951 static void curl_close(BlockDriverState *bs)
952 {
953     BDRVCURLState *s = bs->opaque;
954 
955     DPRINTF("CURL: Close\n");
956     curl_detach_aio_context(bs);
957     qemu_mutex_destroy(&s->mutex);
958 
959     g_free(s->cookie);
960     g_free(s->url);
961     g_free(s->username);
962     g_free(s->proxyusername);
963     g_free(s->proxypassword);
964 }
965 
966 static int64_t curl_getlength(BlockDriverState *bs)
967 {
968     BDRVCURLState *s = bs->opaque;
969     return s->len;
970 }
971 
972 static BlockDriver bdrv_http = {
973     .format_name                = "http",
974     .protocol_name              = "http",
975 
976     .instance_size              = sizeof(BDRVCURLState),
977     .bdrv_parse_filename        = curl_parse_filename,
978     .bdrv_file_open             = curl_open,
979     .bdrv_close                 = curl_close,
980     .bdrv_getlength             = curl_getlength,
981 
982     .bdrv_co_preadv             = curl_co_preadv,
983 
984     .bdrv_detach_aio_context    = curl_detach_aio_context,
985     .bdrv_attach_aio_context    = curl_attach_aio_context,
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 
1004 static BlockDriver bdrv_ftp = {
1005     .format_name                = "ftp",
1006     .protocol_name              = "ftp",
1007 
1008     .instance_size              = sizeof(BDRVCURLState),
1009     .bdrv_parse_filename        = curl_parse_filename,
1010     .bdrv_file_open             = curl_open,
1011     .bdrv_close                 = curl_close,
1012     .bdrv_getlength             = curl_getlength,
1013 
1014     .bdrv_co_preadv             = curl_co_preadv,
1015 
1016     .bdrv_detach_aio_context    = curl_detach_aio_context,
1017     .bdrv_attach_aio_context    = curl_attach_aio_context,
1018 };
1019 
1020 static BlockDriver bdrv_ftps = {
1021     .format_name                = "ftps",
1022     .protocol_name              = "ftps",
1023 
1024     .instance_size              = sizeof(BDRVCURLState),
1025     .bdrv_parse_filename        = curl_parse_filename,
1026     .bdrv_file_open             = curl_open,
1027     .bdrv_close                 = curl_close,
1028     .bdrv_getlength             = curl_getlength,
1029 
1030     .bdrv_co_preadv             = curl_co_preadv,
1031 
1032     .bdrv_detach_aio_context    = curl_detach_aio_context,
1033     .bdrv_attach_aio_context    = curl_attach_aio_context,
1034 };
1035 
1036 static void curl_block_init(void)
1037 {
1038     bdrv_register(&bdrv_http);
1039     bdrv_register(&bdrv_https);
1040     bdrv_register(&bdrv_ftp);
1041     bdrv_register(&bdrv_ftps);
1042 }
1043 
1044 block_init(curl_block_init);
1045