xref: /openbmc/qemu/block/curl.c (revision 795c40b8)
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 FIND_RET_NONE   0
80 #define FIND_RET_OK     1
81 #define FIND_RET_WAIT   2
82 
83 #define CURL_BLOCK_OPT_URL       "url"
84 #define CURL_BLOCK_OPT_READAHEAD "readahead"
85 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
86 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
87 #define CURL_BLOCK_OPT_COOKIE    "cookie"
88 #define CURL_BLOCK_OPT_USERNAME "username"
89 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
90 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
91 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
92 
93 struct BDRVCURLState;
94 
95 typedef struct CURLAIOCB {
96     BlockAIOCB common;
97     QEMUIOVector *qiov;
98 
99     int64_t sector_num;
100     int nb_sectors;
101 
102     size_t start;
103     size_t end;
104 } CURLAIOCB;
105 
106 typedef struct CURLSocket {
107     int fd;
108     QLIST_ENTRY(CURLSocket) next;
109 } CURLSocket;
110 
111 typedef struct CURLState
112 {
113     struct BDRVCURLState *s;
114     CURLAIOCB *acb[CURL_NUM_ACB];
115     CURL *curl;
116     QLIST_HEAD(, CURLSocket) sockets;
117     char *orig_buf;
118     size_t buf_start;
119     size_t buf_off;
120     size_t buf_len;
121     char range[128];
122     char errmsg[CURL_ERROR_SIZE];
123     char in_use;
124 } CURLState;
125 
126 typedef struct BDRVCURLState {
127     CURLM *multi;
128     QEMUTimer timer;
129     size_t len;
130     CURLState states[CURL_NUM_STATES];
131     char *url;
132     size_t readahead_size;
133     bool sslverify;
134     uint64_t timeout;
135     char *cookie;
136     bool accept_range;
137     AioContext *aio_context;
138     QemuMutex mutex;
139     char *username;
140     char *password;
141     char *proxyusername;
142     char *proxypassword;
143 } BDRVCURLState;
144 
145 static void curl_clean_state(CURLState *s);
146 static void curl_multi_do(void *arg);
147 static void curl_multi_read(void *arg);
148 
149 #ifdef NEED_CURL_TIMER_CALLBACK
150 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
151 {
152     BDRVCURLState *s = opaque;
153 
154     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
155     if (timeout_ms == -1) {
156         timer_del(&s->timer);
157     } else {
158         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
159         timer_mod(&s->timer,
160                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
161     }
162     return 0;
163 }
164 #endif
165 
166 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
167                         void *userp, void *sp)
168 {
169     BDRVCURLState *s;
170     CURLState *state = NULL;
171     CURLSocket *socket;
172 
173     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
174     s = state->s;
175 
176     QLIST_FOREACH(socket, &state->sockets, next) {
177         if (socket->fd == fd) {
178             if (action == CURL_POLL_REMOVE) {
179                 QLIST_REMOVE(socket, next);
180                 g_free(socket);
181             }
182             break;
183         }
184     }
185     if (!socket) {
186         socket = g_new0(CURLSocket, 1);
187         socket->fd = fd;
188         QLIST_INSERT_HEAD(&state->sockets, socket, next);
189     }
190     socket = NULL;
191 
192     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, (int)fd);
193     switch (action) {
194         case CURL_POLL_IN:
195             aio_set_fd_handler(s->aio_context, fd, false,
196                                curl_multi_read, NULL, NULL, state);
197             break;
198         case CURL_POLL_OUT:
199             aio_set_fd_handler(s->aio_context, fd, false,
200                                NULL, curl_multi_do, NULL, state);
201             break;
202         case CURL_POLL_INOUT:
203             aio_set_fd_handler(s->aio_context, fd, false,
204                                curl_multi_read, curl_multi_do, NULL, state);
205             break;
206         case CURL_POLL_REMOVE:
207             aio_set_fd_handler(s->aio_context, fd, false,
208                                NULL, NULL, NULL, NULL);
209             break;
210     }
211 
212     return 0;
213 }
214 
215 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
216 {
217     BDRVCURLState *s = opaque;
218     size_t realsize = size * nmemb;
219     const char *accept_line = "Accept-Ranges: bytes";
220 
221     if (realsize >= strlen(accept_line)
222         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
223         s->accept_range = true;
224     }
225 
226     return realsize;
227 }
228 
229 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
230 {
231     CURLState *s = ((CURLState*)opaque);
232     size_t realsize = size * nmemb;
233     int i;
234 
235     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
236 
237     if (!s || !s->orig_buf) {
238         goto read_end;
239     }
240 
241     if (s->buf_off >= s->buf_len) {
242         /* buffer full, read nothing */
243         goto read_end;
244     }
245     realsize = MIN(realsize, s->buf_len - s->buf_off);
246     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
247     s->buf_off += realsize;
248 
249     for(i=0; i<CURL_NUM_ACB; i++) {
250         CURLAIOCB *acb = s->acb[i];
251 
252         if (!acb)
253             continue;
254 
255         if ((s->buf_off >= acb->end)) {
256             size_t request_length = acb->nb_sectors * BDRV_SECTOR_SIZE;
257 
258             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
259                                 acb->end - acb->start);
260 
261             if (acb->end - acb->start < request_length) {
262                 size_t offset = acb->end - acb->start;
263                 qemu_iovec_memset(acb->qiov, offset, 0,
264                                   request_length - offset);
265             }
266 
267             acb->common.cb(acb->common.opaque, 0);
268             qemu_aio_unref(acb);
269             s->acb[i] = NULL;
270         }
271     }
272 
273 read_end:
274     /* curl will error out if we do not return this value */
275     return size * nmemb;
276 }
277 
278 static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len,
279                          CURLAIOCB *acb)
280 {
281     int i;
282     size_t end = start + len;
283     size_t clamped_end = MIN(end, s->len);
284     size_t clamped_len = clamped_end - start;
285 
286     for (i=0; i<CURL_NUM_STATES; i++) {
287         CURLState *state = &s->states[i];
288         size_t buf_end = (state->buf_start + state->buf_off);
289         size_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->common.cb(acb->common.opaque, 0);
309 
310             return FIND_RET_OK;
311         }
312 
313         // Wait for unfinished chunks
314         if (state->in_use &&
315             (start >= state->buf_start) &&
316             (start <= buf_fend) &&
317             (clamped_end >= state->buf_start) &&
318             (clamped_end <= buf_fend))
319         {
320             int j;
321 
322             acb->start = start - state->buf_start;
323             acb->end = acb->start + clamped_len;
324 
325             for (j=0; j<CURL_NUM_ACB; j++) {
326                 if (!state->acb[j]) {
327                     state->acb[j] = acb;
328                     return FIND_RET_WAIT;
329                 }
330             }
331         }
332     }
333 
334     return FIND_RET_NONE;
335 }
336 
337 /* Called with s->mutex held.  */
338 static void curl_multi_check_completion(BDRVCURLState *s)
339 {
340     int msgs_in_queue;
341 
342     /* Try to find done transfers, so we can free the easy
343      * handle again. */
344     for (;;) {
345         CURLMsg *msg;
346         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
347 
348         /* Quit when there are no more completions */
349         if (!msg)
350             break;
351 
352         if (msg->msg == CURLMSG_DONE) {
353             CURLState *state = NULL;
354             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
355                               (char **)&state);
356 
357             /* ACBs for successful messages get completed in curl_read_cb */
358             if (msg->data.result != CURLE_OK) {
359                 int i;
360                 static int errcount = 100;
361 
362                 /* Don't lose the original error message from curl, since
363                  * it contains extra data.
364                  */
365                 if (errcount > 0) {
366                     error_report("curl: %s", state->errmsg);
367                     if (--errcount == 0) {
368                         error_report("curl: further errors suppressed");
369                     }
370                 }
371 
372                 for (i = 0; i < CURL_NUM_ACB; i++) {
373                     CURLAIOCB *acb = state->acb[i];
374 
375                     if (acb == NULL) {
376                         continue;
377                     }
378 
379                     qemu_mutex_unlock(&s->mutex);
380                     acb->common.cb(acb->common.opaque, -EIO);
381                     qemu_mutex_lock(&s->mutex);
382                     qemu_aio_unref(acb);
383                     state->acb[i] = NULL;
384                 }
385             }
386 
387             curl_clean_state(state);
388             break;
389         }
390     }
391 }
392 
393 /* Called with s->mutex held.  */
394 static void curl_multi_do_locked(CURLState *s)
395 {
396     CURLSocket *socket, *next_socket;
397     int running;
398     int r;
399 
400     if (!s->s->multi) {
401         return;
402     }
403 
404     /* Need to use _SAFE because curl_multi_socket_action() may trigger
405      * curl_sock_cb() which might modify this list */
406     QLIST_FOREACH_SAFE(socket, &s->sockets, next, next_socket) {
407         do {
408             r = curl_multi_socket_action(s->s->multi, socket->fd, 0, &running);
409         } while (r == CURLM_CALL_MULTI_PERFORM);
410     }
411 }
412 
413 static void curl_multi_do(void *arg)
414 {
415     CURLState *s = (CURLState *)arg;
416 
417     qemu_mutex_lock(&s->s->mutex);
418     curl_multi_do_locked(s);
419     qemu_mutex_unlock(&s->s->mutex);
420 }
421 
422 static void curl_multi_read(void *arg)
423 {
424     CURLState *s = (CURLState *)arg;
425 
426     qemu_mutex_lock(&s->s->mutex);
427     curl_multi_do_locked(s);
428     curl_multi_check_completion(s->s);
429     qemu_mutex_unlock(&s->s->mutex);
430 }
431 
432 static void curl_multi_timeout_do(void *arg)
433 {
434 #ifdef NEED_CURL_TIMER_CALLBACK
435     BDRVCURLState *s = (BDRVCURLState *)arg;
436     int running;
437 
438     if (!s->multi) {
439         return;
440     }
441 
442     qemu_mutex_lock(&s->mutex);
443     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
444 
445     curl_multi_check_completion(s);
446     qemu_mutex_unlock(&s->mutex);
447 #else
448     abort();
449 #endif
450 }
451 
452 static CURLState *curl_init_state(BlockDriverState *bs, BDRVCURLState *s)
453 {
454     CURLState *state = NULL;
455     int i, j;
456 
457     do {
458         for (i=0; i<CURL_NUM_STATES; i++) {
459             for (j=0; j<CURL_NUM_ACB; j++)
460                 if (s->states[i].acb[j])
461                     continue;
462             if (s->states[i].in_use)
463                 continue;
464 
465             state = &s->states[i];
466             state->in_use = 1;
467             break;
468         }
469         if (!state) {
470             aio_poll(bdrv_get_aio_context(bs), true);
471         }
472     } while(!state);
473 
474     if (!state->curl) {
475         state->curl = curl_easy_init();
476         if (!state->curl) {
477             return NULL;
478         }
479         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
480         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
481                          (long) s->sslverify);
482         if (s->cookie) {
483             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
484         }
485         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
486         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
487                          (void *)curl_read_cb);
488         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
489         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
490         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
491         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
492         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
493         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
494         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
495 
496         if (s->username) {
497             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
498         }
499         if (s->password) {
500             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
501         }
502         if (s->proxyusername) {
503             curl_easy_setopt(state->curl,
504                              CURLOPT_PROXYUSERNAME, s->proxyusername);
505         }
506         if (s->proxypassword) {
507             curl_easy_setopt(state->curl,
508                              CURLOPT_PROXYPASSWORD, s->proxypassword);
509         }
510 
511         /* Restrict supported protocols to avoid security issues in the more
512          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
513          * CVE-2013-0249.
514          *
515          * Restricting protocols is only supported from 7.19.4 upwards.
516          */
517 #if LIBCURL_VERSION_NUM >= 0x071304
518         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
519         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
520 #endif
521 
522 #ifdef DEBUG_VERBOSE
523         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
524 #endif
525     }
526 
527     QLIST_INIT(&state->sockets);
528     state->s = s;
529 
530     return state;
531 }
532 
533 static void curl_clean_state(CURLState *s)
534 {
535     if (s->s->multi)
536         curl_multi_remove_handle(s->s->multi, s->curl);
537 
538     while (!QLIST_EMPTY(&s->sockets)) {
539         CURLSocket *socket = QLIST_FIRST(&s->sockets);
540 
541         QLIST_REMOVE(socket, next);
542         g_free(socket);
543     }
544 
545     s->in_use = 0;
546 }
547 
548 static void curl_parse_filename(const char *filename, QDict *options,
549                                 Error **errp)
550 {
551     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
552 }
553 
554 static void curl_detach_aio_context(BlockDriverState *bs)
555 {
556     BDRVCURLState *s = bs->opaque;
557     int i;
558 
559     for (i = 0; i < CURL_NUM_STATES; i++) {
560         if (s->states[i].in_use) {
561             curl_clean_state(&s->states[i]);
562         }
563         if (s->states[i].curl) {
564             curl_easy_cleanup(s->states[i].curl);
565             s->states[i].curl = NULL;
566         }
567         g_free(s->states[i].orig_buf);
568         s->states[i].orig_buf = NULL;
569     }
570     if (s->multi) {
571         curl_multi_cleanup(s->multi);
572         s->multi = NULL;
573     }
574 
575     timer_del(&s->timer);
576 }
577 
578 static void curl_attach_aio_context(BlockDriverState *bs,
579                                     AioContext *new_context)
580 {
581     BDRVCURLState *s = bs->opaque;
582 
583     aio_timer_init(new_context, &s->timer,
584                    QEMU_CLOCK_REALTIME, SCALE_NS,
585                    curl_multi_timeout_do, s);
586 
587     assert(!s->multi);
588     s->multi = curl_multi_init();
589     s->aio_context = new_context;
590     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
591 #ifdef NEED_CURL_TIMER_CALLBACK
592     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
593     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
594 #endif
595 }
596 
597 static QemuOptsList runtime_opts = {
598     .name = "curl",
599     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
600     .desc = {
601         {
602             .name = CURL_BLOCK_OPT_URL,
603             .type = QEMU_OPT_STRING,
604             .help = "URL to open",
605         },
606         {
607             .name = CURL_BLOCK_OPT_READAHEAD,
608             .type = QEMU_OPT_SIZE,
609             .help = "Readahead size",
610         },
611         {
612             .name = CURL_BLOCK_OPT_SSLVERIFY,
613             .type = QEMU_OPT_BOOL,
614             .help = "Verify SSL certificate"
615         },
616         {
617             .name = CURL_BLOCK_OPT_TIMEOUT,
618             .type = QEMU_OPT_NUMBER,
619             .help = "Curl timeout"
620         },
621         {
622             .name = CURL_BLOCK_OPT_COOKIE,
623             .type = QEMU_OPT_STRING,
624             .help = "Pass the cookie or list of cookies with each request"
625         },
626         {
627             .name = CURL_BLOCK_OPT_USERNAME,
628             .type = QEMU_OPT_STRING,
629             .help = "Username for HTTP auth"
630         },
631         {
632             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
633             .type = QEMU_OPT_STRING,
634             .help = "ID of secret used as password for HTTP auth",
635         },
636         {
637             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
638             .type = QEMU_OPT_STRING,
639             .help = "Username for HTTP proxy auth"
640         },
641         {
642             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
643             .type = QEMU_OPT_STRING,
644             .help = "ID of secret used as password for HTTP proxy auth",
645         },
646         { /* end of list */ }
647     },
648 };
649 
650 
651 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
652                      Error **errp)
653 {
654     BDRVCURLState *s = bs->opaque;
655     CURLState *state = NULL;
656     QemuOpts *opts;
657     Error *local_err = NULL;
658     const char *file;
659     const char *cookie;
660     double d;
661     const char *secretid;
662     const char *protocol_delimiter;
663 
664     static int inited = 0;
665 
666     if (flags & BDRV_O_RDWR) {
667         error_setg(errp, "curl block device does not support writes");
668         return -EROFS;
669     }
670 
671     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
672     qemu_opts_absorb_qdict(opts, options, &local_err);
673     if (local_err) {
674         error_propagate(errp, local_err);
675         goto out_noclean;
676     }
677 
678     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
679                                           READ_AHEAD_DEFAULT);
680     if ((s->readahead_size & 0x1ff) != 0) {
681         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
682                    s->readahead_size);
683         goto out_noclean;
684     }
685 
686     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
687                                      CURL_TIMEOUT_DEFAULT);
688     if (s->timeout > CURL_TIMEOUT_MAX) {
689         error_setg(errp, "timeout parameter is too large or negative");
690         goto out_noclean;
691     }
692 
693     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
694 
695     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
696     s->cookie = g_strdup(cookie);
697 
698     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
699     if (file == NULL) {
700         error_setg(errp, "curl block driver requires an 'url' option");
701         goto out_noclean;
702     }
703 
704     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
705         !strstart(protocol_delimiter, "://", NULL))
706     {
707         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
708                    "start with '%s://')", bs->drv->protocol_name, file,
709                    bs->drv->protocol_name);
710         goto out_noclean;
711     }
712 
713     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
714     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
715 
716     if (secretid) {
717         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
718         if (!s->password) {
719             goto out_noclean;
720         }
721     }
722 
723     s->proxyusername = g_strdup(
724         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
725     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
726     if (secretid) {
727         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
728         if (!s->proxypassword) {
729             goto out_noclean;
730         }
731     }
732 
733     if (!inited) {
734         curl_global_init(CURL_GLOBAL_ALL);
735         inited = 1;
736     }
737 
738     DPRINTF("CURL: Opening %s\n", file);
739     s->aio_context = bdrv_get_aio_context(bs);
740     s->url = g_strdup(file);
741     state = curl_init_state(bs, s);
742     if (!state)
743         goto out_noclean;
744 
745     // Get file size
746 
747     s->accept_range = false;
748     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
749     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
750                      curl_header_cb);
751     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
752     if (curl_easy_perform(state->curl))
753         goto out;
754     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
755         goto out;
756     }
757     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
758      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
759      * known and zero if it is realy zero-length file. */
760 #if LIBCURL_VERSION_NUM >= 0x071304
761     if (d < 0) {
762         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
763                 "Server didn't report file size.");
764         goto out;
765     }
766 #else
767     if (d <= 0) {
768         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
769                 "Unknown file size or zero-length file.");
770         goto out;
771     }
772 #endif
773 
774     s->len = (size_t)d;
775 
776     if ((!strncasecmp(s->url, "http://", strlen("http://"))
777         || !strncasecmp(s->url, "https://", strlen("https://")))
778         && !s->accept_range) {
779         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
780                 "Server does not support 'range' (byte ranges).");
781         goto out;
782     }
783     DPRINTF("CURL: Size = %zd\n", s->len);
784 
785     curl_clean_state(state);
786     curl_easy_cleanup(state->curl);
787     state->curl = NULL;
788 
789     qemu_mutex_init(&s->mutex);
790     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
791 
792     qemu_opts_del(opts);
793     return 0;
794 
795 out:
796     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
797     curl_easy_cleanup(state->curl);
798     state->curl = NULL;
799 out_noclean:
800     g_free(s->cookie);
801     g_free(s->url);
802     qemu_opts_del(opts);
803     return -EINVAL;
804 }
805 
806 static const AIOCBInfo curl_aiocb_info = {
807     .aiocb_size         = sizeof(CURLAIOCB),
808 };
809 
810 
811 static void curl_readv_bh_cb(void *p)
812 {
813     CURLState *state;
814     int running;
815     int ret = -EINPROGRESS;
816 
817     CURLAIOCB *acb = p;
818     BlockDriverState *bs = acb->common.bs;
819     BDRVCURLState *s = bs->opaque;
820 
821     size_t start = acb->sector_num * BDRV_SECTOR_SIZE;
822     size_t end;
823 
824     qemu_mutex_lock(&s->mutex);
825 
826     // In case we have the requested data already (e.g. read-ahead),
827     // we can just call the callback and be done.
828     switch (curl_find_buf(s, start, acb->nb_sectors * BDRV_SECTOR_SIZE, acb)) {
829         case FIND_RET_OK:
830             qemu_aio_unref(acb);
831             // fall through
832         case FIND_RET_WAIT:
833             goto out;
834         default:
835             break;
836     }
837 
838     // No cache found, so let's start a new request
839     state = curl_init_state(acb->common.bs, s);
840     if (!state) {
841         ret = -EIO;
842         goto out;
843     }
844 
845     acb->start = 0;
846     acb->end = MIN(acb->nb_sectors * BDRV_SECTOR_SIZE, s->len - start);
847 
848     state->buf_off = 0;
849     g_free(state->orig_buf);
850     state->buf_start = start;
851     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
852     end = start + state->buf_len - 1;
853     state->orig_buf = g_try_malloc(state->buf_len);
854     if (state->buf_len && state->orig_buf == NULL) {
855         curl_clean_state(state);
856         ret = -ENOMEM;
857         goto out;
858     }
859     state->acb[0] = acb;
860 
861     snprintf(state->range, 127, "%zd-%zd", start, end);
862     DPRINTF("CURL (AIO): Reading %llu at %zd (%s)\n",
863             (acb->nb_sectors * BDRV_SECTOR_SIZE), start, state->range);
864     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
865 
866     curl_multi_add_handle(s->multi, state->curl);
867 
868     /* Tell curl it needs to kick things off */
869     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
870 
871 out:
872     qemu_mutex_unlock(&s->mutex);
873     if (ret != -EINPROGRESS) {
874         acb->common.cb(acb->common.opaque, ret);
875         qemu_aio_unref(acb);
876     }
877 }
878 
879 static BlockAIOCB *curl_aio_readv(BlockDriverState *bs,
880         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
881         BlockCompletionFunc *cb, void *opaque)
882 {
883     CURLAIOCB *acb;
884 
885     acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque);
886 
887     acb->qiov = qiov;
888     acb->sector_num = sector_num;
889     acb->nb_sectors = nb_sectors;
890 
891     aio_bh_schedule_oneshot(bdrv_get_aio_context(bs), curl_readv_bh_cb, acb);
892     return &acb->common;
893 }
894 
895 static void curl_close(BlockDriverState *bs)
896 {
897     BDRVCURLState *s = bs->opaque;
898 
899     DPRINTF("CURL: Close\n");
900     curl_detach_aio_context(bs);
901     qemu_mutex_destroy(&s->mutex);
902 
903     g_free(s->cookie);
904     g_free(s->url);
905 }
906 
907 static int64_t curl_getlength(BlockDriverState *bs)
908 {
909     BDRVCURLState *s = bs->opaque;
910     return s->len;
911 }
912 
913 static BlockDriver bdrv_http = {
914     .format_name                = "http",
915     .protocol_name              = "http",
916 
917     .instance_size              = sizeof(BDRVCURLState),
918     .bdrv_parse_filename        = curl_parse_filename,
919     .bdrv_file_open             = curl_open,
920     .bdrv_close                 = curl_close,
921     .bdrv_getlength             = curl_getlength,
922 
923     .bdrv_aio_readv             = curl_aio_readv,
924 
925     .bdrv_detach_aio_context    = curl_detach_aio_context,
926     .bdrv_attach_aio_context    = curl_attach_aio_context,
927 };
928 
929 static BlockDriver bdrv_https = {
930     .format_name                = "https",
931     .protocol_name              = "https",
932 
933     .instance_size              = sizeof(BDRVCURLState),
934     .bdrv_parse_filename        = curl_parse_filename,
935     .bdrv_file_open             = curl_open,
936     .bdrv_close                 = curl_close,
937     .bdrv_getlength             = curl_getlength,
938 
939     .bdrv_aio_readv             = curl_aio_readv,
940 
941     .bdrv_detach_aio_context    = curl_detach_aio_context,
942     .bdrv_attach_aio_context    = curl_attach_aio_context,
943 };
944 
945 static BlockDriver bdrv_ftp = {
946     .format_name                = "ftp",
947     .protocol_name              = "ftp",
948 
949     .instance_size              = sizeof(BDRVCURLState),
950     .bdrv_parse_filename        = curl_parse_filename,
951     .bdrv_file_open             = curl_open,
952     .bdrv_close                 = curl_close,
953     .bdrv_getlength             = curl_getlength,
954 
955     .bdrv_aio_readv             = curl_aio_readv,
956 
957     .bdrv_detach_aio_context    = curl_detach_aio_context,
958     .bdrv_attach_aio_context    = curl_attach_aio_context,
959 };
960 
961 static BlockDriver bdrv_ftps = {
962     .format_name                = "ftps",
963     .protocol_name              = "ftps",
964 
965     .instance_size              = sizeof(BDRVCURLState),
966     .bdrv_parse_filename        = curl_parse_filename,
967     .bdrv_file_open             = curl_open,
968     .bdrv_close                 = curl_close,
969     .bdrv_getlength             = curl_getlength,
970 
971     .bdrv_aio_readv             = curl_aio_readv,
972 
973     .bdrv_detach_aio_context    = curl_detach_aio_context,
974     .bdrv_attach_aio_context    = curl_attach_aio_context,
975 };
976 
977 static void curl_block_init(void)
978 {
979     bdrv_register(&bdrv_http);
980     bdrv_register(&bdrv_https);
981     bdrv_register(&bdrv_ftp);
982     bdrv_register(&bdrv_ftps);
983 }
984 
985 block_init(curl_block_init);
986