xref: /openbmc/qemu/block/curl.c (revision 10358b6a)
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-common.h"
25 #include "block/block_int.h"
26 #include "qapi/qmp/qbool.h"
27 #include <curl/curl.h>
28 
29 // #define DEBUG
30 // #define DEBUG_VERBOSE
31 
32 #ifdef DEBUG_CURL
33 #define DPRINTF(fmt, ...) do { printf(fmt, ## __VA_ARGS__); } while (0)
34 #else
35 #define DPRINTF(fmt, ...) do { } while (0)
36 #endif
37 
38 #if LIBCURL_VERSION_NUM >= 0x071000
39 /* The multi interface timer callback was introduced in 7.16.0 */
40 #define NEED_CURL_TIMER_CALLBACK
41 #define HAVE_SOCKET_ACTION
42 #endif
43 
44 #ifndef HAVE_SOCKET_ACTION
45 /* If curl_multi_socket_action isn't available, define it statically here in
46  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
47  * less efficient but still safe. */
48 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
49                                             curl_socket_t sockfd,
50                                             int ev_bitmask,
51                                             int *running_handles)
52 {
53     return curl_multi_socket(multi_handle, sockfd, running_handles);
54 }
55 #define curl_multi_socket_action __curl_multi_socket_action
56 #endif
57 
58 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
59                    CURLPROTO_FTP | CURLPROTO_FTPS | \
60                    CURLPROTO_TFTP)
61 
62 #define CURL_NUM_STATES 8
63 #define CURL_NUM_ACB    8
64 #define SECTOR_SIZE     512
65 #define READ_AHEAD_DEFAULT (256 * 1024)
66 
67 #define FIND_RET_NONE   0
68 #define FIND_RET_OK     1
69 #define FIND_RET_WAIT   2
70 
71 #define CURL_BLOCK_OPT_URL       "url"
72 #define CURL_BLOCK_OPT_READAHEAD "readahead"
73 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
74 
75 struct BDRVCURLState;
76 
77 typedef struct CURLAIOCB {
78     BlockDriverAIOCB common;
79     QEMUBH *bh;
80     QEMUIOVector *qiov;
81 
82     int64_t sector_num;
83     int nb_sectors;
84 
85     size_t start;
86     size_t end;
87 } CURLAIOCB;
88 
89 typedef struct CURLState
90 {
91     struct BDRVCURLState *s;
92     CURLAIOCB *acb[CURL_NUM_ACB];
93     CURL *curl;
94     curl_socket_t sock_fd;
95     char *orig_buf;
96     size_t buf_start;
97     size_t buf_off;
98     size_t buf_len;
99     char range[128];
100     char errmsg[CURL_ERROR_SIZE];
101     char in_use;
102 } CURLState;
103 
104 typedef struct BDRVCURLState {
105     CURLM *multi;
106     QEMUTimer timer;
107     size_t len;
108     CURLState states[CURL_NUM_STATES];
109     char *url;
110     size_t readahead_size;
111     bool sslverify;
112     bool accept_range;
113     AioContext *aio_context;
114 } BDRVCURLState;
115 
116 static void curl_clean_state(CURLState *s);
117 static void curl_multi_do(void *arg);
118 static void curl_multi_read(void *arg);
119 
120 #ifdef NEED_CURL_TIMER_CALLBACK
121 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
122 {
123     BDRVCURLState *s = opaque;
124 
125     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
126     if (timeout_ms == -1) {
127         timer_del(&s->timer);
128     } else {
129         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
130         timer_mod(&s->timer,
131                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
132     }
133     return 0;
134 }
135 #endif
136 
137 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
138                         void *userp, void *sp)
139 {
140     BDRVCURLState *s;
141     CURLState *state = NULL;
142     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
143     state->sock_fd = fd;
144     s = state->s;
145 
146     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, fd);
147     switch (action) {
148         case CURL_POLL_IN:
149             aio_set_fd_handler(s->aio_context, fd, curl_multi_read,
150                                NULL, state);
151             break;
152         case CURL_POLL_OUT:
153             aio_set_fd_handler(s->aio_context, fd, NULL, curl_multi_do, state);
154             break;
155         case CURL_POLL_INOUT:
156             aio_set_fd_handler(s->aio_context, fd, curl_multi_read,
157                                curl_multi_do, state);
158             break;
159         case CURL_POLL_REMOVE:
160             aio_set_fd_handler(s->aio_context, fd, NULL, NULL, NULL);
161             break;
162     }
163 
164     return 0;
165 }
166 
167 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
168 {
169     BDRVCURLState *s = opaque;
170     size_t realsize = size * nmemb;
171     const char *accept_line = "Accept-Ranges: bytes";
172 
173     if (realsize >= strlen(accept_line)
174         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
175         s->accept_range = true;
176     }
177 
178     return realsize;
179 }
180 
181 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
182 {
183     CURLState *s = ((CURLState*)opaque);
184     size_t realsize = size * nmemb;
185     int i;
186 
187     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
188 
189     if (!s || !s->orig_buf)
190         return 0;
191 
192     if (s->buf_off >= s->buf_len) {
193         /* buffer full, read nothing */
194         return 0;
195     }
196     realsize = MIN(realsize, s->buf_len - s->buf_off);
197     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
198     s->buf_off += realsize;
199 
200     for(i=0; i<CURL_NUM_ACB; i++) {
201         CURLAIOCB *acb = s->acb[i];
202 
203         if (!acb)
204             continue;
205 
206         if ((s->buf_off >= acb->end)) {
207             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
208                                 acb->end - acb->start);
209             acb->common.cb(acb->common.opaque, 0);
210             qemu_aio_release(acb);
211             s->acb[i] = NULL;
212         }
213     }
214 
215     return realsize;
216 }
217 
218 static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len,
219                          CURLAIOCB *acb)
220 {
221     int i;
222     size_t end = start + len;
223 
224     for (i=0; i<CURL_NUM_STATES; i++) {
225         CURLState *state = &s->states[i];
226         size_t buf_end = (state->buf_start + state->buf_off);
227         size_t buf_fend = (state->buf_start + state->buf_len);
228 
229         if (!state->orig_buf)
230             continue;
231         if (!state->buf_off)
232             continue;
233 
234         // Does the existing buffer cover our section?
235         if ((start >= state->buf_start) &&
236             (start <= buf_end) &&
237             (end >= state->buf_start) &&
238             (end <= buf_end))
239         {
240             char *buf = state->orig_buf + (start - state->buf_start);
241 
242             qemu_iovec_from_buf(acb->qiov, 0, buf, len);
243             acb->common.cb(acb->common.opaque, 0);
244 
245             return FIND_RET_OK;
246         }
247 
248         // Wait for unfinished chunks
249         if (state->in_use &&
250             (start >= state->buf_start) &&
251             (start <= buf_fend) &&
252             (end >= state->buf_start) &&
253             (end <= buf_fend))
254         {
255             int j;
256 
257             acb->start = start - state->buf_start;
258             acb->end = acb->start + len;
259 
260             for (j=0; j<CURL_NUM_ACB; j++) {
261                 if (!state->acb[j]) {
262                     state->acb[j] = acb;
263                     return FIND_RET_WAIT;
264                 }
265             }
266         }
267     }
268 
269     return FIND_RET_NONE;
270 }
271 
272 static void curl_multi_check_completion(BDRVCURLState *s)
273 {
274     int msgs_in_queue;
275 
276     /* Try to find done transfers, so we can free the easy
277      * handle again. */
278     for (;;) {
279         CURLMsg *msg;
280         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
281 
282         /* Quit when there are no more completions */
283         if (!msg)
284             break;
285 
286         if (msg->msg == CURLMSG_DONE) {
287             CURLState *state = NULL;
288             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
289                               (char **)&state);
290 
291             /* ACBs for successful messages get completed in curl_read_cb */
292             if (msg->data.result != CURLE_OK) {
293                 int i;
294                 for (i = 0; i < CURL_NUM_ACB; i++) {
295                     CURLAIOCB *acb = state->acb[i];
296 
297                     if (acb == NULL) {
298                         continue;
299                     }
300 
301                     acb->common.cb(acb->common.opaque, -EIO);
302                     qemu_aio_release(acb);
303                     state->acb[i] = NULL;
304                 }
305             }
306 
307             curl_clean_state(state);
308             break;
309         }
310     }
311 }
312 
313 static void curl_multi_do(void *arg)
314 {
315     CURLState *s = (CURLState *)arg;
316     int running;
317     int r;
318 
319     if (!s->s->multi) {
320         return;
321     }
322 
323     do {
324         r = curl_multi_socket_action(s->s->multi, s->sock_fd, 0, &running);
325     } while(r == CURLM_CALL_MULTI_PERFORM);
326 
327 }
328 
329 static void curl_multi_read(void *arg)
330 {
331     CURLState *s = (CURLState *)arg;
332 
333     curl_multi_do(arg);
334     curl_multi_check_completion(s->s);
335 }
336 
337 static void curl_multi_timeout_do(void *arg)
338 {
339 #ifdef NEED_CURL_TIMER_CALLBACK
340     BDRVCURLState *s = (BDRVCURLState *)arg;
341     int running;
342 
343     if (!s->multi) {
344         return;
345     }
346 
347     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
348 
349     curl_multi_check_completion(s);
350 #else
351     abort();
352 #endif
353 }
354 
355 static CURLState *curl_init_state(BDRVCURLState *s)
356 {
357     CURLState *state = NULL;
358     int i, j;
359 
360     do {
361         for (i=0; i<CURL_NUM_STATES; i++) {
362             for (j=0; j<CURL_NUM_ACB; j++)
363                 if (s->states[i].acb[j])
364                     continue;
365             if (s->states[i].in_use)
366                 continue;
367 
368             state = &s->states[i];
369             state->in_use = 1;
370             break;
371         }
372         if (!state) {
373             aio_poll(state->s->aio_context, true);
374         }
375     } while(!state);
376 
377     if (!state->curl) {
378         state->curl = curl_easy_init();
379         if (!state->curl) {
380             return NULL;
381         }
382         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
383         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
384                          (long) s->sslverify);
385         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, 5);
386         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
387                          (void *)curl_read_cb);
388         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
389         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
390         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
391         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
392         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
393         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
394         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
395 
396         /* Restrict supported protocols to avoid security issues in the more
397          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
398          * CVE-2013-0249.
399          *
400          * Restricting protocols is only supported from 7.19.4 upwards.
401          */
402 #if LIBCURL_VERSION_NUM >= 0x071304
403         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
404         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
405 #endif
406 
407 #ifdef DEBUG_VERBOSE
408         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
409 #endif
410     }
411 
412     state->s = s;
413 
414     return state;
415 }
416 
417 static void curl_clean_state(CURLState *s)
418 {
419     if (s->s->multi)
420         curl_multi_remove_handle(s->s->multi, s->curl);
421     s->in_use = 0;
422 }
423 
424 static void curl_parse_filename(const char *filename, QDict *options,
425                                 Error **errp)
426 {
427     qdict_put(options, CURL_BLOCK_OPT_URL, qstring_from_str(filename));
428 }
429 
430 static void curl_detach_aio_context(BlockDriverState *bs)
431 {
432     BDRVCURLState *s = bs->opaque;
433     int i;
434 
435     for (i = 0; i < CURL_NUM_STATES; i++) {
436         if (s->states[i].in_use) {
437             curl_clean_state(&s->states[i]);
438         }
439         if (s->states[i].curl) {
440             curl_easy_cleanup(s->states[i].curl);
441             s->states[i].curl = NULL;
442         }
443         g_free(s->states[i].orig_buf);
444         s->states[i].orig_buf = NULL;
445     }
446     if (s->multi) {
447         curl_multi_cleanup(s->multi);
448         s->multi = NULL;
449     }
450 
451     timer_del(&s->timer);
452 }
453 
454 static void curl_attach_aio_context(BlockDriverState *bs,
455                                     AioContext *new_context)
456 {
457     BDRVCURLState *s = bs->opaque;
458 
459     aio_timer_init(new_context, &s->timer,
460                    QEMU_CLOCK_REALTIME, SCALE_NS,
461                    curl_multi_timeout_do, s);
462 
463     assert(!s->multi);
464     s->multi = curl_multi_init();
465     s->aio_context = new_context;
466     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
467 #ifdef NEED_CURL_TIMER_CALLBACK
468     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
469     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
470 #endif
471 }
472 
473 static QemuOptsList runtime_opts = {
474     .name = "curl",
475     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
476     .desc = {
477         {
478             .name = CURL_BLOCK_OPT_URL,
479             .type = QEMU_OPT_STRING,
480             .help = "URL to open",
481         },
482         {
483             .name = CURL_BLOCK_OPT_READAHEAD,
484             .type = QEMU_OPT_SIZE,
485             .help = "Readahead size",
486         },
487         {
488             .name = CURL_BLOCK_OPT_SSLVERIFY,
489             .type = QEMU_OPT_BOOL,
490             .help = "Verify SSL certificate"
491         },
492         { /* end of list */ }
493     },
494 };
495 
496 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
497                      Error **errp)
498 {
499     BDRVCURLState *s = bs->opaque;
500     CURLState *state = NULL;
501     QemuOpts *opts;
502     Error *local_err = NULL;
503     const char *file;
504     double d;
505 
506     static int inited = 0;
507 
508     if (flags & BDRV_O_RDWR) {
509         error_setg(errp, "curl block device does not support writes");
510         return -EROFS;
511     }
512 
513     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
514     qemu_opts_absorb_qdict(opts, options, &local_err);
515     if (local_err) {
516         error_propagate(errp, local_err);
517         goto out_noclean;
518     }
519 
520     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
521                                           READ_AHEAD_DEFAULT);
522     if ((s->readahead_size & 0x1ff) != 0) {
523         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
524                    s->readahead_size);
525         goto out_noclean;
526     }
527 
528     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
529 
530     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
531     if (file == NULL) {
532         error_setg(errp, "curl block driver requires an 'url' option");
533         goto out_noclean;
534     }
535 
536     if (!inited) {
537         curl_global_init(CURL_GLOBAL_ALL);
538         inited = 1;
539     }
540 
541     DPRINTF("CURL: Opening %s\n", file);
542     s->aio_context = bdrv_get_aio_context(bs);
543     s->url = g_strdup(file);
544     state = curl_init_state(s);
545     if (!state)
546         goto out_noclean;
547 
548     // Get file size
549 
550     s->accept_range = false;
551     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
552     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
553                      curl_header_cb);
554     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
555     if (curl_easy_perform(state->curl))
556         goto out;
557     curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d);
558     if (d)
559         s->len = (size_t)d;
560     else if(!s->len)
561         goto out;
562     if ((!strncasecmp(s->url, "http://", strlen("http://"))
563         || !strncasecmp(s->url, "https://", strlen("https://")))
564         && !s->accept_range) {
565         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
566                 "Server does not support 'range' (byte ranges).");
567         goto out;
568     }
569     DPRINTF("CURL: Size = %zd\n", s->len);
570 
571     curl_clean_state(state);
572     curl_easy_cleanup(state->curl);
573     state->curl = NULL;
574 
575     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
576 
577     qemu_opts_del(opts);
578     return 0;
579 
580 out:
581     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
582     curl_easy_cleanup(state->curl);
583     state->curl = NULL;
584 out_noclean:
585     g_free(s->url);
586     qemu_opts_del(opts);
587     return -EINVAL;
588 }
589 
590 static void curl_aio_cancel(BlockDriverAIOCB *blockacb)
591 {
592     // Do we have to implement canceling? Seems to work without...
593 }
594 
595 static const AIOCBInfo curl_aiocb_info = {
596     .aiocb_size         = sizeof(CURLAIOCB),
597     .cancel             = curl_aio_cancel,
598 };
599 
600 
601 static void curl_readv_bh_cb(void *p)
602 {
603     CURLState *state;
604     int running;
605 
606     CURLAIOCB *acb = p;
607     BDRVCURLState *s = acb->common.bs->opaque;
608 
609     qemu_bh_delete(acb->bh);
610     acb->bh = NULL;
611 
612     size_t start = acb->sector_num * SECTOR_SIZE;
613     size_t end;
614 
615     // In case we have the requested data already (e.g. read-ahead),
616     // we can just call the callback and be done.
617     switch (curl_find_buf(s, start, acb->nb_sectors * SECTOR_SIZE, acb)) {
618         case FIND_RET_OK:
619             qemu_aio_release(acb);
620             // fall through
621         case FIND_RET_WAIT:
622             return;
623         default:
624             break;
625     }
626 
627     // No cache found, so let's start a new request
628     state = curl_init_state(s);
629     if (!state) {
630         acb->common.cb(acb->common.opaque, -EIO);
631         qemu_aio_release(acb);
632         return;
633     }
634 
635     acb->start = 0;
636     acb->end = (acb->nb_sectors * SECTOR_SIZE);
637 
638     state->buf_off = 0;
639     g_free(state->orig_buf);
640     state->buf_start = start;
641     state->buf_len = acb->end + s->readahead_size;
642     end = MIN(start + state->buf_len, s->len) - 1;
643     state->orig_buf = g_malloc(state->buf_len);
644     state->acb[0] = acb;
645 
646     snprintf(state->range, 127, "%zd-%zd", start, end);
647     DPRINTF("CURL (AIO): Reading %d at %zd (%s)\n",
648             (acb->nb_sectors * SECTOR_SIZE), start, state->range);
649     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
650 
651     curl_multi_add_handle(s->multi, state->curl);
652 
653     /* Tell curl it needs to kick things off */
654     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
655 }
656 
657 static BlockDriverAIOCB *curl_aio_readv(BlockDriverState *bs,
658         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
659         BlockDriverCompletionFunc *cb, void *opaque)
660 {
661     CURLAIOCB *acb;
662 
663     acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque);
664 
665     acb->qiov = qiov;
666     acb->sector_num = sector_num;
667     acb->nb_sectors = nb_sectors;
668 
669     acb->bh = aio_bh_new(bdrv_get_aio_context(bs), curl_readv_bh_cb, acb);
670     qemu_bh_schedule(acb->bh);
671     return &acb->common;
672 }
673 
674 static void curl_close(BlockDriverState *bs)
675 {
676     BDRVCURLState *s = bs->opaque;
677 
678     DPRINTF("CURL: Close\n");
679     curl_detach_aio_context(bs);
680 
681     g_free(s->url);
682 }
683 
684 static int64_t curl_getlength(BlockDriverState *bs)
685 {
686     BDRVCURLState *s = bs->opaque;
687     return s->len;
688 }
689 
690 static BlockDriver bdrv_http = {
691     .format_name                = "http",
692     .protocol_name              = "http",
693 
694     .instance_size              = sizeof(BDRVCURLState),
695     .bdrv_parse_filename        = curl_parse_filename,
696     .bdrv_file_open             = curl_open,
697     .bdrv_close                 = curl_close,
698     .bdrv_getlength             = curl_getlength,
699 
700     .bdrv_aio_readv             = curl_aio_readv,
701 
702     .bdrv_detach_aio_context    = curl_detach_aio_context,
703     .bdrv_attach_aio_context    = curl_attach_aio_context,
704 };
705 
706 static BlockDriver bdrv_https = {
707     .format_name                = "https",
708     .protocol_name              = "https",
709 
710     .instance_size              = sizeof(BDRVCURLState),
711     .bdrv_parse_filename        = curl_parse_filename,
712     .bdrv_file_open             = curl_open,
713     .bdrv_close                 = curl_close,
714     .bdrv_getlength             = curl_getlength,
715 
716     .bdrv_aio_readv             = curl_aio_readv,
717 
718     .bdrv_detach_aio_context    = curl_detach_aio_context,
719     .bdrv_attach_aio_context    = curl_attach_aio_context,
720 };
721 
722 static BlockDriver bdrv_ftp = {
723     .format_name                = "ftp",
724     .protocol_name              = "ftp",
725 
726     .instance_size              = sizeof(BDRVCURLState),
727     .bdrv_parse_filename        = curl_parse_filename,
728     .bdrv_file_open             = curl_open,
729     .bdrv_close                 = curl_close,
730     .bdrv_getlength             = curl_getlength,
731 
732     .bdrv_aio_readv             = curl_aio_readv,
733 
734     .bdrv_detach_aio_context    = curl_detach_aio_context,
735     .bdrv_attach_aio_context    = curl_attach_aio_context,
736 };
737 
738 static BlockDriver bdrv_ftps = {
739     .format_name                = "ftps",
740     .protocol_name              = "ftps",
741 
742     .instance_size              = sizeof(BDRVCURLState),
743     .bdrv_parse_filename        = curl_parse_filename,
744     .bdrv_file_open             = curl_open,
745     .bdrv_close                 = curl_close,
746     .bdrv_getlength             = curl_getlength,
747 
748     .bdrv_aio_readv             = curl_aio_readv,
749 
750     .bdrv_detach_aio_context    = curl_detach_aio_context,
751     .bdrv_attach_aio_context    = curl_attach_aio_context,
752 };
753 
754 static BlockDriver bdrv_tftp = {
755     .format_name                = "tftp",
756     .protocol_name              = "tftp",
757 
758     .instance_size              = sizeof(BDRVCURLState),
759     .bdrv_parse_filename        = curl_parse_filename,
760     .bdrv_file_open             = curl_open,
761     .bdrv_close                 = curl_close,
762     .bdrv_getlength             = curl_getlength,
763 
764     .bdrv_aio_readv             = curl_aio_readv,
765 
766     .bdrv_detach_aio_context    = curl_detach_aio_context,
767     .bdrv_attach_aio_context    = curl_attach_aio_context,
768 };
769 
770 static void curl_block_init(void)
771 {
772     bdrv_register(&bdrv_http);
773     bdrv_register(&bdrv_https);
774     bdrv_register(&bdrv_ftp);
775     bdrv_register(&bdrv_ftps);
776     bdrv_register(&bdrv_tftp);
777 }
778 
779 block_init(curl_block_init);
780