xref: /openbmc/qemu/block/curl.c (revision 4b4629d9)
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                    CURLPROTO_TFTP)
73 
74 #define CURL_NUM_STATES 8
75 #define CURL_NUM_ACB    8
76 #define SECTOR_SIZE     512
77 #define READ_AHEAD_DEFAULT (256 * 1024)
78 #define CURL_TIMEOUT_DEFAULT 5
79 #define CURL_TIMEOUT_MAX 10000
80 
81 #define FIND_RET_NONE   0
82 #define FIND_RET_OK     1
83 #define FIND_RET_WAIT   2
84 
85 #define CURL_BLOCK_OPT_URL       "url"
86 #define CURL_BLOCK_OPT_READAHEAD "readahead"
87 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
88 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
89 #define CURL_BLOCK_OPT_COOKIE    "cookie"
90 #define CURL_BLOCK_OPT_USERNAME "username"
91 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
92 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
93 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
94 
95 struct BDRVCURLState;
96 
97 typedef struct CURLAIOCB {
98     BlockAIOCB common;
99     QEMUBH *bh;
100     QEMUIOVector *qiov;
101 
102     int64_t sector_num;
103     int nb_sectors;
104 
105     size_t start;
106     size_t end;
107 } CURLAIOCB;
108 
109 typedef struct CURLState
110 {
111     struct BDRVCURLState *s;
112     CURLAIOCB *acb[CURL_NUM_ACB];
113     CURL *curl;
114     curl_socket_t sock_fd;
115     char *orig_buf;
116     size_t buf_start;
117     size_t buf_off;
118     size_t buf_len;
119     char range[128];
120     char errmsg[CURL_ERROR_SIZE];
121     char in_use;
122 } CURLState;
123 
124 typedef struct BDRVCURLState {
125     CURLM *multi;
126     QEMUTimer timer;
127     size_t len;
128     CURLState states[CURL_NUM_STATES];
129     char *url;
130     size_t readahead_size;
131     bool sslverify;
132     uint64_t timeout;
133     char *cookie;
134     bool accept_range;
135     AioContext *aio_context;
136     char *username;
137     char *password;
138     char *proxyusername;
139     char *proxypassword;
140 } BDRVCURLState;
141 
142 static void curl_clean_state(CURLState *s);
143 static void curl_multi_do(void *arg);
144 static void curl_multi_read(void *arg);
145 
146 #ifdef NEED_CURL_TIMER_CALLBACK
147 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
148 {
149     BDRVCURLState *s = opaque;
150 
151     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
152     if (timeout_ms == -1) {
153         timer_del(&s->timer);
154     } else {
155         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
156         timer_mod(&s->timer,
157                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
158     }
159     return 0;
160 }
161 #endif
162 
163 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
164                         void *userp, void *sp)
165 {
166     BDRVCURLState *s;
167     CURLState *state = NULL;
168     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
169     state->sock_fd = fd;
170     s = state->s;
171 
172     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, fd);
173     switch (action) {
174         case CURL_POLL_IN:
175             aio_set_fd_handler(s->aio_context, fd, false,
176                                curl_multi_read, NULL, state);
177             break;
178         case CURL_POLL_OUT:
179             aio_set_fd_handler(s->aio_context, fd, false,
180                                NULL, curl_multi_do, state);
181             break;
182         case CURL_POLL_INOUT:
183             aio_set_fd_handler(s->aio_context, fd, false,
184                                curl_multi_read, curl_multi_do, state);
185             break;
186         case CURL_POLL_REMOVE:
187             aio_set_fd_handler(s->aio_context, fd, false,
188                                NULL, NULL, NULL);
189             break;
190     }
191 
192     return 0;
193 }
194 
195 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
196 {
197     BDRVCURLState *s = opaque;
198     size_t realsize = size * nmemb;
199     const char *accept_line = "Accept-Ranges: bytes";
200 
201     if (realsize >= strlen(accept_line)
202         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
203         s->accept_range = true;
204     }
205 
206     return realsize;
207 }
208 
209 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
210 {
211     CURLState *s = ((CURLState*)opaque);
212     size_t realsize = size * nmemb;
213     int i;
214 
215     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
216 
217     if (!s || !s->orig_buf)
218         return 0;
219 
220     if (s->buf_off >= s->buf_len) {
221         /* buffer full, read nothing */
222         return 0;
223     }
224     realsize = MIN(realsize, s->buf_len - s->buf_off);
225     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
226     s->buf_off += realsize;
227 
228     for(i=0; i<CURL_NUM_ACB; i++) {
229         CURLAIOCB *acb = s->acb[i];
230 
231         if (!acb)
232             continue;
233 
234         if ((s->buf_off >= acb->end)) {
235             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
236                                 acb->end - acb->start);
237             acb->common.cb(acb->common.opaque, 0);
238             qemu_aio_unref(acb);
239             s->acb[i] = NULL;
240         }
241     }
242 
243     return realsize;
244 }
245 
246 static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len,
247                          CURLAIOCB *acb)
248 {
249     int i;
250     size_t end = start + len;
251 
252     for (i=0; i<CURL_NUM_STATES; i++) {
253         CURLState *state = &s->states[i];
254         size_t buf_end = (state->buf_start + state->buf_off);
255         size_t buf_fend = (state->buf_start + state->buf_len);
256 
257         if (!state->orig_buf)
258             continue;
259         if (!state->buf_off)
260             continue;
261 
262         // Does the existing buffer cover our section?
263         if ((start >= state->buf_start) &&
264             (start <= buf_end) &&
265             (end >= state->buf_start) &&
266             (end <= buf_end))
267         {
268             char *buf = state->orig_buf + (start - state->buf_start);
269 
270             qemu_iovec_from_buf(acb->qiov, 0, buf, len);
271             acb->common.cb(acb->common.opaque, 0);
272 
273             return FIND_RET_OK;
274         }
275 
276         // Wait for unfinished chunks
277         if (state->in_use &&
278             (start >= state->buf_start) &&
279             (start <= buf_fend) &&
280             (end >= state->buf_start) &&
281             (end <= buf_fend))
282         {
283             int j;
284 
285             acb->start = start - state->buf_start;
286             acb->end = acb->start + len;
287 
288             for (j=0; j<CURL_NUM_ACB; j++) {
289                 if (!state->acb[j]) {
290                     state->acb[j] = acb;
291                     return FIND_RET_WAIT;
292                 }
293             }
294         }
295     }
296 
297     return FIND_RET_NONE;
298 }
299 
300 static void curl_multi_check_completion(BDRVCURLState *s)
301 {
302     int msgs_in_queue;
303 
304     /* Try to find done transfers, so we can free the easy
305      * handle again. */
306     for (;;) {
307         CURLMsg *msg;
308         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
309 
310         /* Quit when there are no more completions */
311         if (!msg)
312             break;
313 
314         if (msg->msg == CURLMSG_DONE) {
315             CURLState *state = NULL;
316             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
317                               (char **)&state);
318 
319             /* ACBs for successful messages get completed in curl_read_cb */
320             if (msg->data.result != CURLE_OK) {
321                 int i;
322                 static int errcount = 100;
323 
324                 /* Don't lose the original error message from curl, since
325                  * it contains extra data.
326                  */
327                 if (errcount > 0) {
328                     error_report("curl: %s", state->errmsg);
329                     if (--errcount == 0) {
330                         error_report("curl: further errors suppressed");
331                     }
332                 }
333 
334                 for (i = 0; i < CURL_NUM_ACB; i++) {
335                     CURLAIOCB *acb = state->acb[i];
336 
337                     if (acb == NULL) {
338                         continue;
339                     }
340 
341                     acb->common.cb(acb->common.opaque, -EPROTO);
342                     qemu_aio_unref(acb);
343                     state->acb[i] = NULL;
344                 }
345             }
346 
347             curl_clean_state(state);
348             break;
349         }
350     }
351 }
352 
353 static void curl_multi_do(void *arg)
354 {
355     CURLState *s = (CURLState *)arg;
356     int running;
357     int r;
358 
359     if (!s->s->multi) {
360         return;
361     }
362 
363     do {
364         r = curl_multi_socket_action(s->s->multi, s->sock_fd, 0, &running);
365     } while(r == CURLM_CALL_MULTI_PERFORM);
366 
367 }
368 
369 static void curl_multi_read(void *arg)
370 {
371     CURLState *s = (CURLState *)arg;
372 
373     curl_multi_do(arg);
374     curl_multi_check_completion(s->s);
375 }
376 
377 static void curl_multi_timeout_do(void *arg)
378 {
379 #ifdef NEED_CURL_TIMER_CALLBACK
380     BDRVCURLState *s = (BDRVCURLState *)arg;
381     int running;
382 
383     if (!s->multi) {
384         return;
385     }
386 
387     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
388 
389     curl_multi_check_completion(s);
390 #else
391     abort();
392 #endif
393 }
394 
395 static CURLState *curl_init_state(BlockDriverState *bs, BDRVCURLState *s)
396 {
397     CURLState *state = NULL;
398     int i, j;
399 
400     do {
401         for (i=0; i<CURL_NUM_STATES; i++) {
402             for (j=0; j<CURL_NUM_ACB; j++)
403                 if (s->states[i].acb[j])
404                     continue;
405             if (s->states[i].in_use)
406                 continue;
407 
408             state = &s->states[i];
409             state->in_use = 1;
410             break;
411         }
412         if (!state) {
413             aio_poll(bdrv_get_aio_context(bs), true);
414         }
415     } while(!state);
416 
417     if (!state->curl) {
418         state->curl = curl_easy_init();
419         if (!state->curl) {
420             return NULL;
421         }
422         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
423         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
424                          (long) s->sslverify);
425         if (s->cookie) {
426             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
427         }
428         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
429         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
430                          (void *)curl_read_cb);
431         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
432         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
433         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
434         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
435         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
436         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
437         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
438 
439         if (s->username) {
440             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
441         }
442         if (s->password) {
443             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
444         }
445         if (s->proxyusername) {
446             curl_easy_setopt(state->curl,
447                              CURLOPT_PROXYUSERNAME, s->proxyusername);
448         }
449         if (s->proxypassword) {
450             curl_easy_setopt(state->curl,
451                              CURLOPT_PROXYPASSWORD, s->proxypassword);
452         }
453 
454         /* Restrict supported protocols to avoid security issues in the more
455          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
456          * CVE-2013-0249.
457          *
458          * Restricting protocols is only supported from 7.19.4 upwards.
459          */
460 #if LIBCURL_VERSION_NUM >= 0x071304
461         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
462         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
463 #endif
464 
465 #ifdef DEBUG_VERBOSE
466         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
467 #endif
468     }
469 
470     state->s = s;
471 
472     return state;
473 }
474 
475 static void curl_clean_state(CURLState *s)
476 {
477     if (s->s->multi)
478         curl_multi_remove_handle(s->s->multi, s->curl);
479     s->in_use = 0;
480 }
481 
482 static void curl_parse_filename(const char *filename, QDict *options,
483                                 Error **errp)
484 {
485     qdict_put(options, CURL_BLOCK_OPT_URL, qstring_from_str(filename));
486 }
487 
488 static void curl_detach_aio_context(BlockDriverState *bs)
489 {
490     BDRVCURLState *s = bs->opaque;
491     int i;
492 
493     for (i = 0; i < CURL_NUM_STATES; i++) {
494         if (s->states[i].in_use) {
495             curl_clean_state(&s->states[i]);
496         }
497         if (s->states[i].curl) {
498             curl_easy_cleanup(s->states[i].curl);
499             s->states[i].curl = NULL;
500         }
501         g_free(s->states[i].orig_buf);
502         s->states[i].orig_buf = NULL;
503     }
504     if (s->multi) {
505         curl_multi_cleanup(s->multi);
506         s->multi = NULL;
507     }
508 
509     timer_del(&s->timer);
510 }
511 
512 static void curl_attach_aio_context(BlockDriverState *bs,
513                                     AioContext *new_context)
514 {
515     BDRVCURLState *s = bs->opaque;
516 
517     aio_timer_init(new_context, &s->timer,
518                    QEMU_CLOCK_REALTIME, SCALE_NS,
519                    curl_multi_timeout_do, s);
520 
521     assert(!s->multi);
522     s->multi = curl_multi_init();
523     s->aio_context = new_context;
524     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
525 #ifdef NEED_CURL_TIMER_CALLBACK
526     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
527     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
528 #endif
529 }
530 
531 static QemuOptsList runtime_opts = {
532     .name = "curl",
533     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
534     .desc = {
535         {
536             .name = CURL_BLOCK_OPT_URL,
537             .type = QEMU_OPT_STRING,
538             .help = "URL to open",
539         },
540         {
541             .name = CURL_BLOCK_OPT_READAHEAD,
542             .type = QEMU_OPT_SIZE,
543             .help = "Readahead size",
544         },
545         {
546             .name = CURL_BLOCK_OPT_SSLVERIFY,
547             .type = QEMU_OPT_BOOL,
548             .help = "Verify SSL certificate"
549         },
550         {
551             .name = CURL_BLOCK_OPT_TIMEOUT,
552             .type = QEMU_OPT_NUMBER,
553             .help = "Curl timeout"
554         },
555         {
556             .name = CURL_BLOCK_OPT_COOKIE,
557             .type = QEMU_OPT_STRING,
558             .help = "Pass the cookie or list of cookies with each request"
559         },
560         {
561             .name = CURL_BLOCK_OPT_USERNAME,
562             .type = QEMU_OPT_STRING,
563             .help = "Username for HTTP auth"
564         },
565         {
566             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
567             .type = QEMU_OPT_STRING,
568             .help = "ID of secret used as password for HTTP auth",
569         },
570         {
571             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
572             .type = QEMU_OPT_STRING,
573             .help = "Username for HTTP proxy auth"
574         },
575         {
576             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
577             .type = QEMU_OPT_STRING,
578             .help = "ID of secret used as password for HTTP proxy auth",
579         },
580         { /* end of list */ }
581     },
582 };
583 
584 
585 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
586                      Error **errp)
587 {
588     BDRVCURLState *s = bs->opaque;
589     CURLState *state = NULL;
590     QemuOpts *opts;
591     Error *local_err = NULL;
592     const char *file;
593     const char *cookie;
594     double d;
595     const char *secretid;
596 
597     static int inited = 0;
598 
599     if (flags & BDRV_O_RDWR) {
600         error_setg(errp, "curl block device does not support writes");
601         return -EROFS;
602     }
603 
604     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
605     qemu_opts_absorb_qdict(opts, options, &local_err);
606     if (local_err) {
607         error_propagate(errp, local_err);
608         goto out_noclean;
609     }
610 
611     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
612                                           READ_AHEAD_DEFAULT);
613     if ((s->readahead_size & 0x1ff) != 0) {
614         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
615                    s->readahead_size);
616         goto out_noclean;
617     }
618 
619     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
620                                      CURL_TIMEOUT_DEFAULT);
621     if (s->timeout > CURL_TIMEOUT_MAX) {
622         error_setg(errp, "timeout parameter is too large or negative");
623         goto out_noclean;
624     }
625 
626     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
627 
628     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
629     s->cookie = g_strdup(cookie);
630 
631     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
632     if (file == NULL) {
633         error_setg(errp, "curl block driver requires an 'url' option");
634         goto out_noclean;
635     }
636 
637     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
638     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
639 
640     if (secretid) {
641         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
642         if (!s->password) {
643             goto out_noclean;
644         }
645     }
646 
647     s->proxyusername = g_strdup(
648         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
649     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
650     if (secretid) {
651         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
652         if (!s->proxypassword) {
653             goto out_noclean;
654         }
655     }
656 
657     if (!inited) {
658         curl_global_init(CURL_GLOBAL_ALL);
659         inited = 1;
660     }
661 
662     DPRINTF("CURL: Opening %s\n", file);
663     s->aio_context = bdrv_get_aio_context(bs);
664     s->url = g_strdup(file);
665     state = curl_init_state(bs, s);
666     if (!state)
667         goto out_noclean;
668 
669     // Get file size
670 
671     s->accept_range = false;
672     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
673     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
674                      curl_header_cb);
675     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
676     if (curl_easy_perform(state->curl))
677         goto out;
678     curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d);
679     if (d)
680         s->len = (size_t)d;
681     else if(!s->len)
682         goto out;
683     if ((!strncasecmp(s->url, "http://", strlen("http://"))
684         || !strncasecmp(s->url, "https://", strlen("https://")))
685         && !s->accept_range) {
686         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
687                 "Server does not support 'range' (byte ranges).");
688         goto out;
689     }
690     DPRINTF("CURL: Size = %zd\n", s->len);
691 
692     curl_clean_state(state);
693     curl_easy_cleanup(state->curl);
694     state->curl = NULL;
695 
696     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
697 
698     qemu_opts_del(opts);
699     return 0;
700 
701 out:
702     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
703     curl_easy_cleanup(state->curl);
704     state->curl = NULL;
705 out_noclean:
706     g_free(s->cookie);
707     g_free(s->url);
708     qemu_opts_del(opts);
709     return -EINVAL;
710 }
711 
712 static const AIOCBInfo curl_aiocb_info = {
713     .aiocb_size         = sizeof(CURLAIOCB),
714 };
715 
716 
717 static void curl_readv_bh_cb(void *p)
718 {
719     CURLState *state;
720     int running;
721 
722     CURLAIOCB *acb = p;
723     BDRVCURLState *s = acb->common.bs->opaque;
724 
725     qemu_bh_delete(acb->bh);
726     acb->bh = NULL;
727 
728     size_t start = acb->sector_num * SECTOR_SIZE;
729     size_t end;
730 
731     // In case we have the requested data already (e.g. read-ahead),
732     // we can just call the callback and be done.
733     switch (curl_find_buf(s, start, acb->nb_sectors * SECTOR_SIZE, acb)) {
734         case FIND_RET_OK:
735             qemu_aio_unref(acb);
736             // fall through
737         case FIND_RET_WAIT:
738             return;
739         default:
740             break;
741     }
742 
743     // No cache found, so let's start a new request
744     state = curl_init_state(acb->common.bs, s);
745     if (!state) {
746         acb->common.cb(acb->common.opaque, -EIO);
747         qemu_aio_unref(acb);
748         return;
749     }
750 
751     acb->start = 0;
752     acb->end = (acb->nb_sectors * SECTOR_SIZE);
753 
754     state->buf_off = 0;
755     g_free(state->orig_buf);
756     state->buf_start = start;
757     state->buf_len = acb->end + s->readahead_size;
758     end = MIN(start + state->buf_len, s->len) - 1;
759     state->orig_buf = g_try_malloc(state->buf_len);
760     if (state->buf_len && state->orig_buf == NULL) {
761         curl_clean_state(state);
762         acb->common.cb(acb->common.opaque, -ENOMEM);
763         qemu_aio_unref(acb);
764         return;
765     }
766     state->acb[0] = acb;
767 
768     snprintf(state->range, 127, "%zd-%zd", start, end);
769     DPRINTF("CURL (AIO): Reading %d at %zd (%s)\n",
770             (acb->nb_sectors * SECTOR_SIZE), start, state->range);
771     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
772 
773     curl_multi_add_handle(s->multi, state->curl);
774 
775     /* Tell curl it needs to kick things off */
776     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
777 }
778 
779 static BlockAIOCB *curl_aio_readv(BlockDriverState *bs,
780         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
781         BlockCompletionFunc *cb, void *opaque)
782 {
783     CURLAIOCB *acb;
784 
785     acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque);
786 
787     acb->qiov = qiov;
788     acb->sector_num = sector_num;
789     acb->nb_sectors = nb_sectors;
790 
791     acb->bh = aio_bh_new(bdrv_get_aio_context(bs), curl_readv_bh_cb, acb);
792     qemu_bh_schedule(acb->bh);
793     return &acb->common;
794 }
795 
796 static void curl_close(BlockDriverState *bs)
797 {
798     BDRVCURLState *s = bs->opaque;
799 
800     DPRINTF("CURL: Close\n");
801     curl_detach_aio_context(bs);
802 
803     g_free(s->cookie);
804     g_free(s->url);
805 }
806 
807 static int64_t curl_getlength(BlockDriverState *bs)
808 {
809     BDRVCURLState *s = bs->opaque;
810     return s->len;
811 }
812 
813 static BlockDriver bdrv_http = {
814     .format_name                = "http",
815     .protocol_name              = "http",
816 
817     .instance_size              = sizeof(BDRVCURLState),
818     .bdrv_parse_filename        = curl_parse_filename,
819     .bdrv_file_open             = curl_open,
820     .bdrv_close                 = curl_close,
821     .bdrv_getlength             = curl_getlength,
822 
823     .bdrv_aio_readv             = curl_aio_readv,
824 
825     .bdrv_detach_aio_context    = curl_detach_aio_context,
826     .bdrv_attach_aio_context    = curl_attach_aio_context,
827 };
828 
829 static BlockDriver bdrv_https = {
830     .format_name                = "https",
831     .protocol_name              = "https",
832 
833     .instance_size              = sizeof(BDRVCURLState),
834     .bdrv_parse_filename        = curl_parse_filename,
835     .bdrv_file_open             = curl_open,
836     .bdrv_close                 = curl_close,
837     .bdrv_getlength             = curl_getlength,
838 
839     .bdrv_aio_readv             = curl_aio_readv,
840 
841     .bdrv_detach_aio_context    = curl_detach_aio_context,
842     .bdrv_attach_aio_context    = curl_attach_aio_context,
843 };
844 
845 static BlockDriver bdrv_ftp = {
846     .format_name                = "ftp",
847     .protocol_name              = "ftp",
848 
849     .instance_size              = sizeof(BDRVCURLState),
850     .bdrv_parse_filename        = curl_parse_filename,
851     .bdrv_file_open             = curl_open,
852     .bdrv_close                 = curl_close,
853     .bdrv_getlength             = curl_getlength,
854 
855     .bdrv_aio_readv             = curl_aio_readv,
856 
857     .bdrv_detach_aio_context    = curl_detach_aio_context,
858     .bdrv_attach_aio_context    = curl_attach_aio_context,
859 };
860 
861 static BlockDriver bdrv_ftps = {
862     .format_name                = "ftps",
863     .protocol_name              = "ftps",
864 
865     .instance_size              = sizeof(BDRVCURLState),
866     .bdrv_parse_filename        = curl_parse_filename,
867     .bdrv_file_open             = curl_open,
868     .bdrv_close                 = curl_close,
869     .bdrv_getlength             = curl_getlength,
870 
871     .bdrv_aio_readv             = curl_aio_readv,
872 
873     .bdrv_detach_aio_context    = curl_detach_aio_context,
874     .bdrv_attach_aio_context    = curl_attach_aio_context,
875 };
876 
877 static BlockDriver bdrv_tftp = {
878     .format_name                = "tftp",
879     .protocol_name              = "tftp",
880 
881     .instance_size              = sizeof(BDRVCURLState),
882     .bdrv_parse_filename        = curl_parse_filename,
883     .bdrv_file_open             = curl_open,
884     .bdrv_close                 = curl_close,
885     .bdrv_getlength             = curl_getlength,
886 
887     .bdrv_aio_readv             = curl_aio_readv,
888 
889     .bdrv_detach_aio_context    = curl_detach_aio_context,
890     .bdrv_attach_aio_context    = curl_attach_aio_context,
891 };
892 
893 static void curl_block_init(void)
894 {
895     bdrv_register(&bdrv_http);
896     bdrv_register(&bdrv_https);
897     bdrv_register(&bdrv_ftp);
898     bdrv_register(&bdrv_ftps);
899     bdrv_register(&bdrv_tftp);
900 }
901 
902 block_init(curl_block_init);
903