xref: /openbmc/qemu/block/curl.c (revision 745a4f5e)
1 /*
2  * QEMU Block driver for CURL images
3  *
4  * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "qapi/error.h"
27 #include "qemu/error-report.h"
28 #include "qemu/option.h"
29 #include "block/block_int.h"
30 #include "qapi/qmp/qdict.h"
31 #include "qapi/qmp/qstring.h"
32 #include "crypto/secret.h"
33 #include <curl/curl.h>
34 #include "qemu/cutils.h"
35 
36 // #define DEBUG_CURL
37 // #define DEBUG_VERBOSE
38 
39 #ifdef DEBUG_CURL
40 #define DEBUG_CURL_PRINT 1
41 #else
42 #define DEBUG_CURL_PRINT 0
43 #endif
44 #define DPRINTF(fmt, ...)                                            \
45     do {                                                             \
46         if (DEBUG_CURL_PRINT) {                                      \
47             fprintf(stderr, fmt, ## __VA_ARGS__);                    \
48         }                                                            \
49     } while (0)
50 
51 #if LIBCURL_VERSION_NUM >= 0x071000
52 /* The multi interface timer callback was introduced in 7.16.0 */
53 #define NEED_CURL_TIMER_CALLBACK
54 #define HAVE_SOCKET_ACTION
55 #endif
56 
57 #ifndef HAVE_SOCKET_ACTION
58 /* If curl_multi_socket_action isn't available, define it statically here in
59  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
60  * less efficient but still safe. */
61 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
62                                             curl_socket_t sockfd,
63                                             int ev_bitmask,
64                                             int *running_handles)
65 {
66     return curl_multi_socket(multi_handle, sockfd, running_handles);
67 }
68 #define curl_multi_socket_action __curl_multi_socket_action
69 #endif
70 
71 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
72                    CURLPROTO_FTP | CURLPROTO_FTPS)
73 
74 #define CURL_NUM_STATES 8
75 #define CURL_NUM_ACB    8
76 #define READ_AHEAD_DEFAULT (256 * 1024)
77 #define CURL_TIMEOUT_DEFAULT 5
78 #define CURL_TIMEOUT_MAX 10000
79 
80 #define CURL_BLOCK_OPT_URL       "url"
81 #define CURL_BLOCK_OPT_READAHEAD "readahead"
82 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
83 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
84 #define CURL_BLOCK_OPT_COOKIE    "cookie"
85 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
86 #define CURL_BLOCK_OPT_USERNAME "username"
87 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
88 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
89 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
90 
91 struct BDRVCURLState;
92 
93 static bool libcurl_initialized;
94 
95 typedef struct CURLAIOCB {
96     Coroutine *co;
97     QEMUIOVector *qiov;
98 
99     uint64_t offset;
100     uint64_t bytes;
101     int ret;
102 
103     size_t start;
104     size_t end;
105 } CURLAIOCB;
106 
107 typedef struct CURLSocket {
108     int fd;
109     QLIST_ENTRY(CURLSocket) next;
110 } CURLSocket;
111 
112 typedef struct CURLState
113 {
114     struct BDRVCURLState *s;
115     CURLAIOCB *acb[CURL_NUM_ACB];
116     CURL *curl;
117     QLIST_HEAD(, CURLSocket) sockets;
118     char *orig_buf;
119     uint64_t buf_start;
120     size_t buf_off;
121     size_t buf_len;
122     char range[128];
123     char errmsg[CURL_ERROR_SIZE];
124     char in_use;
125 } CURLState;
126 
127 typedef struct BDRVCURLState {
128     CURLM *multi;
129     QEMUTimer timer;
130     uint64_t len;
131     CURLState states[CURL_NUM_STATES];
132     char *url;
133     size_t readahead_size;
134     bool sslverify;
135     uint64_t timeout;
136     char *cookie;
137     bool accept_range;
138     AioContext *aio_context;
139     QemuMutex mutex;
140     CoQueue free_state_waitq;
141     char *username;
142     char *password;
143     char *proxyusername;
144     char *proxypassword;
145 } BDRVCURLState;
146 
147 static void curl_clean_state(CURLState *s);
148 static void curl_multi_do(void *arg);
149 static void curl_multi_read(void *arg);
150 
151 #ifdef NEED_CURL_TIMER_CALLBACK
152 /* Called from curl_multi_do_locked, with s->mutex held.  */
153 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
154 {
155     BDRVCURLState *s = opaque;
156 
157     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
158     if (timeout_ms == -1) {
159         timer_del(&s->timer);
160     } else {
161         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
162         timer_mod(&s->timer,
163                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
164     }
165     return 0;
166 }
167 #endif
168 
169 /* Called from curl_multi_do_locked, with s->mutex held.  */
170 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
171                         void *userp, void *sp)
172 {
173     BDRVCURLState *s;
174     CURLState *state = NULL;
175     CURLSocket *socket;
176 
177     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
178     s = state->s;
179 
180     QLIST_FOREACH(socket, &state->sockets, next) {
181         if (socket->fd == fd) {
182             if (action == CURL_POLL_REMOVE) {
183                 QLIST_REMOVE(socket, next);
184                 g_free(socket);
185             }
186             break;
187         }
188     }
189     if (!socket) {
190         socket = g_new0(CURLSocket, 1);
191         socket->fd = fd;
192         QLIST_INSERT_HEAD(&state->sockets, socket, next);
193     }
194     socket = NULL;
195 
196     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, (int)fd);
197     switch (action) {
198         case CURL_POLL_IN:
199             aio_set_fd_handler(s->aio_context, fd, false,
200                                curl_multi_read, NULL, NULL, state);
201             break;
202         case CURL_POLL_OUT:
203             aio_set_fd_handler(s->aio_context, fd, false,
204                                NULL, curl_multi_do, NULL, state);
205             break;
206         case CURL_POLL_INOUT:
207             aio_set_fd_handler(s->aio_context, fd, false,
208                                curl_multi_read, curl_multi_do, NULL, state);
209             break;
210         case CURL_POLL_REMOVE:
211             aio_set_fd_handler(s->aio_context, fd, false,
212                                NULL, NULL, NULL, NULL);
213             break;
214     }
215 
216     return 0;
217 }
218 
219 /* Called from curl_multi_do_locked, with s->mutex held.  */
220 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
221 {
222     BDRVCURLState *s = opaque;
223     size_t realsize = size * nmemb;
224     const char *accept_line = "Accept-Ranges: bytes";
225 
226     if (realsize >= strlen(accept_line)
227         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
228         s->accept_range = true;
229     }
230 
231     return realsize;
232 }
233 
234 /* Called from curl_multi_do_locked, with s->mutex held.  */
235 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
236 {
237     CURLState *s = ((CURLState*)opaque);
238     size_t realsize = size * nmemb;
239     int i;
240 
241     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
242 
243     if (!s || !s->orig_buf) {
244         goto read_end;
245     }
246 
247     if (s->buf_off >= s->buf_len) {
248         /* buffer full, read nothing */
249         goto read_end;
250     }
251     realsize = MIN(realsize, s->buf_len - s->buf_off);
252     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
253     s->buf_off += realsize;
254 
255     for(i=0; i<CURL_NUM_ACB; i++) {
256         CURLAIOCB *acb = s->acb[i];
257 
258         if (!acb)
259             continue;
260 
261         if ((s->buf_off >= acb->end)) {
262             size_t request_length = acb->bytes;
263 
264             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
265                                 acb->end - acb->start);
266 
267             if (acb->end - acb->start < request_length) {
268                 size_t offset = acb->end - acb->start;
269                 qemu_iovec_memset(acb->qiov, offset, 0,
270                                   request_length - offset);
271             }
272 
273             acb->ret = 0;
274             s->acb[i] = NULL;
275             qemu_mutex_unlock(&s->s->mutex);
276             aio_co_wake(acb->co);
277             qemu_mutex_lock(&s->s->mutex);
278         }
279     }
280 
281 read_end:
282     /* curl will error out if we do not return this value */
283     return size * nmemb;
284 }
285 
286 /* Called with s->mutex held.  */
287 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
288                           CURLAIOCB *acb)
289 {
290     int i;
291     uint64_t end = start + len;
292     uint64_t clamped_end = MIN(end, s->len);
293     uint64_t clamped_len = clamped_end - start;
294 
295     for (i=0; i<CURL_NUM_STATES; i++) {
296         CURLState *state = &s->states[i];
297         uint64_t buf_end = (state->buf_start + state->buf_off);
298         uint64_t buf_fend = (state->buf_start + state->buf_len);
299 
300         if (!state->orig_buf)
301             continue;
302         if (!state->buf_off)
303             continue;
304 
305         // Does the existing buffer cover our section?
306         if ((start >= state->buf_start) &&
307             (start <= buf_end) &&
308             (clamped_end >= state->buf_start) &&
309             (clamped_end <= buf_end))
310         {
311             char *buf = state->orig_buf + (start - state->buf_start);
312 
313             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
314             if (clamped_len < len) {
315                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
316             }
317             acb->ret = 0;
318             return true;
319         }
320 
321         // Wait for unfinished chunks
322         if (state->in_use &&
323             (start >= state->buf_start) &&
324             (start <= buf_fend) &&
325             (clamped_end >= state->buf_start) &&
326             (clamped_end <= buf_fend))
327         {
328             int j;
329 
330             acb->start = start - state->buf_start;
331             acb->end = acb->start + clamped_len;
332 
333             for (j=0; j<CURL_NUM_ACB; j++) {
334                 if (!state->acb[j]) {
335                     state->acb[j] = acb;
336                     return true;
337                 }
338             }
339         }
340     }
341 
342     return false;
343 }
344 
345 /* Called with s->mutex held.  */
346 static void curl_multi_check_completion(BDRVCURLState *s)
347 {
348     int msgs_in_queue;
349 
350     /* Try to find done transfers, so we can free the easy
351      * handle again. */
352     for (;;) {
353         CURLMsg *msg;
354         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
355 
356         /* Quit when there are no more completions */
357         if (!msg)
358             break;
359 
360         if (msg->msg == CURLMSG_DONE) {
361             CURLState *state = NULL;
362             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
363                               (char **)&state);
364 
365             /* ACBs for successful messages get completed in curl_read_cb */
366             if (msg->data.result != CURLE_OK) {
367                 int i;
368                 static int errcount = 100;
369 
370                 /* Don't lose the original error message from curl, since
371                  * it contains extra data.
372                  */
373                 if (errcount > 0) {
374                     error_report("curl: %s", state->errmsg);
375                     if (--errcount == 0) {
376                         error_report("curl: further errors suppressed");
377                     }
378                 }
379 
380                 for (i = 0; i < CURL_NUM_ACB; i++) {
381                     CURLAIOCB *acb = state->acb[i];
382 
383                     if (acb == NULL) {
384                         continue;
385                     }
386 
387                     acb->ret = -EIO;
388                     state->acb[i] = NULL;
389                     qemu_mutex_unlock(&s->mutex);
390                     aio_co_wake(acb->co);
391                     qemu_mutex_lock(&s->mutex);
392                 }
393             }
394 
395             curl_clean_state(state);
396             break;
397         }
398     }
399 }
400 
401 /* Called with s->mutex held.  */
402 static void curl_multi_do_locked(CURLState *s)
403 {
404     CURLSocket *socket, *next_socket;
405     int running;
406     int r;
407 
408     if (!s->s->multi) {
409         return;
410     }
411 
412     /* Need to use _SAFE because curl_multi_socket_action() may trigger
413      * curl_sock_cb() which might modify this list */
414     QLIST_FOREACH_SAFE(socket, &s->sockets, next, next_socket) {
415         do {
416             r = curl_multi_socket_action(s->s->multi, socket->fd, 0, &running);
417         } while (r == CURLM_CALL_MULTI_PERFORM);
418     }
419 }
420 
421 static void curl_multi_do(void *arg)
422 {
423     CURLState *s = (CURLState *)arg;
424 
425     qemu_mutex_lock(&s->s->mutex);
426     curl_multi_do_locked(s);
427     qemu_mutex_unlock(&s->s->mutex);
428 }
429 
430 static void curl_multi_read(void *arg)
431 {
432     CURLState *s = (CURLState *)arg;
433 
434     qemu_mutex_lock(&s->s->mutex);
435     curl_multi_do_locked(s);
436     curl_multi_check_completion(s->s);
437     qemu_mutex_unlock(&s->s->mutex);
438 }
439 
440 static void curl_multi_timeout_do(void *arg)
441 {
442 #ifdef NEED_CURL_TIMER_CALLBACK
443     BDRVCURLState *s = (BDRVCURLState *)arg;
444     int running;
445 
446     if (!s->multi) {
447         return;
448     }
449 
450     qemu_mutex_lock(&s->mutex);
451     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
452 
453     curl_multi_check_completion(s);
454     qemu_mutex_unlock(&s->mutex);
455 #else
456     abort();
457 #endif
458 }
459 
460 /* Called with s->mutex held.  */
461 static CURLState *curl_find_state(BDRVCURLState *s)
462 {
463     CURLState *state = NULL;
464     int i;
465 
466     for (i = 0; i < CURL_NUM_STATES; i++) {
467         if (!s->states[i].in_use) {
468             state = &s->states[i];
469             state->in_use = 1;
470             break;
471         }
472     }
473     return state;
474 }
475 
476 static int curl_init_state(BDRVCURLState *s, CURLState *state)
477 {
478     if (!state->curl) {
479         state->curl = curl_easy_init();
480         if (!state->curl) {
481             return -EIO;
482         }
483         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
484         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
485                          (long) s->sslverify);
486         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
487                          s->sslverify ? 2L : 0L);
488         if (s->cookie) {
489             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
490         }
491         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
492         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
493                          (void *)curl_read_cb);
494         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
495         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
496         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
497         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
498         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
499         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
500         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
501 
502         if (s->username) {
503             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
504         }
505         if (s->password) {
506             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
507         }
508         if (s->proxyusername) {
509             curl_easy_setopt(state->curl,
510                              CURLOPT_PROXYUSERNAME, s->proxyusername);
511         }
512         if (s->proxypassword) {
513             curl_easy_setopt(state->curl,
514                              CURLOPT_PROXYPASSWORD, s->proxypassword);
515         }
516 
517         /* Restrict supported protocols to avoid security issues in the more
518          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
519          * CVE-2013-0249.
520          *
521          * Restricting protocols is only supported from 7.19.4 upwards.
522          */
523 #if LIBCURL_VERSION_NUM >= 0x071304
524         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
525         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
526 #endif
527 
528 #ifdef DEBUG_VERBOSE
529         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
530 #endif
531     }
532 
533     QLIST_INIT(&state->sockets);
534     state->s = s;
535 
536     return 0;
537 }
538 
539 /* Called with s->mutex held.  */
540 static void curl_clean_state(CURLState *s)
541 {
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     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
560 }
561 
562 static void curl_parse_filename(const char *filename, QDict *options,
563                                 Error **errp)
564 {
565     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
566 }
567 
568 static void curl_detach_aio_context(BlockDriverState *bs)
569 {
570     BDRVCURLState *s = bs->opaque;
571     int i;
572 
573     qemu_mutex_lock(&s->mutex);
574     for (i = 0; i < CURL_NUM_STATES; i++) {
575         if (s->states[i].in_use) {
576             curl_clean_state(&s->states[i]);
577         }
578         if (s->states[i].curl) {
579             curl_easy_cleanup(s->states[i].curl);
580             s->states[i].curl = NULL;
581         }
582         g_free(s->states[i].orig_buf);
583         s->states[i].orig_buf = NULL;
584     }
585     if (s->multi) {
586         curl_multi_cleanup(s->multi);
587         s->multi = NULL;
588     }
589     qemu_mutex_unlock(&s->mutex);
590 
591     timer_del(&s->timer);
592 }
593 
594 static void curl_attach_aio_context(BlockDriverState *bs,
595                                     AioContext *new_context)
596 {
597     BDRVCURLState *s = bs->opaque;
598 
599     aio_timer_init(new_context, &s->timer,
600                    QEMU_CLOCK_REALTIME, SCALE_NS,
601                    curl_multi_timeout_do, s);
602 
603     assert(!s->multi);
604     s->multi = curl_multi_init();
605     s->aio_context = new_context;
606     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
607 #ifdef NEED_CURL_TIMER_CALLBACK
608     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
609     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
610 #endif
611 }
612 
613 static QemuOptsList runtime_opts = {
614     .name = "curl",
615     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
616     .desc = {
617         {
618             .name = CURL_BLOCK_OPT_URL,
619             .type = QEMU_OPT_STRING,
620             .help = "URL to open",
621         },
622         {
623             .name = CURL_BLOCK_OPT_READAHEAD,
624             .type = QEMU_OPT_SIZE,
625             .help = "Readahead size",
626         },
627         {
628             .name = CURL_BLOCK_OPT_SSLVERIFY,
629             .type = QEMU_OPT_BOOL,
630             .help = "Verify SSL certificate"
631         },
632         {
633             .name = CURL_BLOCK_OPT_TIMEOUT,
634             .type = QEMU_OPT_NUMBER,
635             .help = "Curl timeout"
636         },
637         {
638             .name = CURL_BLOCK_OPT_COOKIE,
639             .type = QEMU_OPT_STRING,
640             .help = "Pass the cookie or list of cookies with each request"
641         },
642         {
643             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
644             .type = QEMU_OPT_STRING,
645             .help = "ID of secret used as cookie passed with each request"
646         },
647         {
648             .name = CURL_BLOCK_OPT_USERNAME,
649             .type = QEMU_OPT_STRING,
650             .help = "Username for HTTP auth"
651         },
652         {
653             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
654             .type = QEMU_OPT_STRING,
655             .help = "ID of secret used as password for HTTP auth",
656         },
657         {
658             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
659             .type = QEMU_OPT_STRING,
660             .help = "Username for HTTP proxy auth"
661         },
662         {
663             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
664             .type = QEMU_OPT_STRING,
665             .help = "ID of secret used as password for HTTP proxy auth",
666         },
667         { /* end of list */ }
668     },
669 };
670 
671 
672 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
673                      Error **errp)
674 {
675     BDRVCURLState *s = bs->opaque;
676     CURLState *state = NULL;
677     QemuOpts *opts;
678     Error *local_err = NULL;
679     const char *file;
680     const char *cookie;
681     const char *cookie_secret;
682     double d;
683     const char *secretid;
684     const char *protocol_delimiter;
685     int ret;
686 
687     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
688                                     errp);
689     if (ret < 0) {
690         return ret;
691     }
692 
693     if (!libcurl_initialized) {
694         ret = curl_global_init(CURL_GLOBAL_ALL);
695         if (ret) {
696             error_setg(errp, "libcurl initialization failed with %d", ret);
697             return -EIO;
698         }
699         libcurl_initialized = true;
700     }
701 
702     qemu_mutex_init(&s->mutex);
703     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
704     qemu_opts_absorb_qdict(opts, options, &local_err);
705     if (local_err) {
706         error_propagate(errp, local_err);
707         goto out_noclean;
708     }
709 
710     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
711                                           READ_AHEAD_DEFAULT);
712     if ((s->readahead_size & 0x1ff) != 0) {
713         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
714                    s->readahead_size);
715         goto out_noclean;
716     }
717 
718     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
719                                      CURL_TIMEOUT_DEFAULT);
720     if (s->timeout > CURL_TIMEOUT_MAX) {
721         error_setg(errp, "timeout parameter is too large or negative");
722         goto out_noclean;
723     }
724 
725     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
726 
727     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
728     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
729 
730     if (cookie && cookie_secret) {
731         error_setg(errp,
732                    "curl driver cannot handle both cookie and cookie secret");
733         goto out_noclean;
734     }
735 
736     if (cookie_secret) {
737         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
738         if (!s->cookie) {
739             goto out_noclean;
740         }
741     } else {
742         s->cookie = g_strdup(cookie);
743     }
744 
745     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
746     if (file == NULL) {
747         error_setg(errp, "curl block driver requires an 'url' option");
748         goto out_noclean;
749     }
750 
751     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
752         !strstart(protocol_delimiter, "://", NULL))
753     {
754         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
755                    "start with '%s://')", bs->drv->protocol_name, file,
756                    bs->drv->protocol_name);
757         goto out_noclean;
758     }
759 
760     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
761     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
762 
763     if (secretid) {
764         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
765         if (!s->password) {
766             goto out_noclean;
767         }
768     }
769 
770     s->proxyusername = g_strdup(
771         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
772     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
773     if (secretid) {
774         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
775         if (!s->proxypassword) {
776             goto out_noclean;
777         }
778     }
779 
780     DPRINTF("CURL: Opening %s\n", file);
781     qemu_co_queue_init(&s->free_state_waitq);
782     s->aio_context = bdrv_get_aio_context(bs);
783     s->url = g_strdup(file);
784     qemu_mutex_lock(&s->mutex);
785     state = curl_find_state(s);
786     qemu_mutex_unlock(&s->mutex);
787     if (!state) {
788         goto out_noclean;
789     }
790 
791     // Get file size
792 
793     if (curl_init_state(s, state) < 0) {
794         goto out;
795     }
796 
797     s->accept_range = false;
798     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
799     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
800                      curl_header_cb);
801     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
802     if (curl_easy_perform(state->curl))
803         goto out;
804     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
805         goto out;
806     }
807     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
808      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
809      * known and zero if it is really zero-length file. */
810 #if LIBCURL_VERSION_NUM >= 0x071304
811     if (d < 0) {
812         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
813                 "Server didn't report file size.");
814         goto out;
815     }
816 #else
817     if (d <= 0) {
818         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
819                 "Unknown file size or zero-length file.");
820         goto out;
821     }
822 #endif
823 
824     s->len = d;
825 
826     if ((!strncasecmp(s->url, "http://", strlen("http://"))
827         || !strncasecmp(s->url, "https://", strlen("https://")))
828         && !s->accept_range) {
829         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
830                 "Server does not support 'range' (byte ranges).");
831         goto out;
832     }
833     DPRINTF("CURL: Size = %" PRIu64 "\n", s->len);
834 
835     qemu_mutex_lock(&s->mutex);
836     curl_clean_state(state);
837     qemu_mutex_unlock(&s->mutex);
838     curl_easy_cleanup(state->curl);
839     state->curl = NULL;
840 
841     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
842 
843     qemu_opts_del(opts);
844     return 0;
845 
846 out:
847     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
848     curl_easy_cleanup(state->curl);
849     state->curl = NULL;
850 out_noclean:
851     qemu_mutex_destroy(&s->mutex);
852     g_free(s->cookie);
853     g_free(s->url);
854     g_free(s->username);
855     g_free(s->proxyusername);
856     g_free(s->proxypassword);
857     qemu_opts_del(opts);
858     return -EINVAL;
859 }
860 
861 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
862 {
863     CURLState *state;
864     int running;
865 
866     BDRVCURLState *s = bs->opaque;
867 
868     uint64_t start = acb->offset;
869     uint64_t end;
870 
871     qemu_mutex_lock(&s->mutex);
872 
873     // In case we have the requested data already (e.g. read-ahead),
874     // we can just call the callback and be done.
875     if (curl_find_buf(s, start, acb->bytes, acb)) {
876         goto out;
877     }
878 
879     // No cache found, so let's start a new request
880     for (;;) {
881         state = curl_find_state(s);
882         if (state) {
883             break;
884         }
885         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
886     }
887 
888     if (curl_init_state(s, state) < 0) {
889         curl_clean_state(state);
890         acb->ret = -EIO;
891         goto out;
892     }
893 
894     acb->start = 0;
895     acb->end = MIN(acb->bytes, s->len - start);
896 
897     state->buf_off = 0;
898     g_free(state->orig_buf);
899     state->buf_start = start;
900     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
901     end = start + state->buf_len - 1;
902     state->orig_buf = g_try_malloc(state->buf_len);
903     if (state->buf_len && state->orig_buf == NULL) {
904         curl_clean_state(state);
905         acb->ret = -ENOMEM;
906         goto out;
907     }
908     state->acb[0] = acb;
909 
910     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
911     DPRINTF("CURL (AIO): Reading %" PRIu64 " at %" PRIu64 " (%s)\n",
912             acb->bytes, start, state->range);
913     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
914 
915     curl_multi_add_handle(s->multi, state->curl);
916 
917     /* Tell curl it needs to kick things off */
918     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
919 
920 out:
921     qemu_mutex_unlock(&s->mutex);
922 }
923 
924 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
925         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
926 {
927     CURLAIOCB acb = {
928         .co = qemu_coroutine_self(),
929         .ret = -EINPROGRESS,
930         .qiov = qiov,
931         .offset = offset,
932         .bytes = bytes
933     };
934 
935     curl_setup_preadv(bs, &acb);
936     while (acb.ret == -EINPROGRESS) {
937         qemu_coroutine_yield();
938     }
939     return acb.ret;
940 }
941 
942 static void curl_close(BlockDriverState *bs)
943 {
944     BDRVCURLState *s = bs->opaque;
945 
946     DPRINTF("CURL: Close\n");
947     curl_detach_aio_context(bs);
948     qemu_mutex_destroy(&s->mutex);
949 
950     g_free(s->cookie);
951     g_free(s->url);
952     g_free(s->username);
953     g_free(s->proxyusername);
954     g_free(s->proxypassword);
955 }
956 
957 static int64_t curl_getlength(BlockDriverState *bs)
958 {
959     BDRVCURLState *s = bs->opaque;
960     return s->len;
961 }
962 
963 static BlockDriver bdrv_http = {
964     .format_name                = "http",
965     .protocol_name              = "http",
966 
967     .instance_size              = sizeof(BDRVCURLState),
968     .bdrv_parse_filename        = curl_parse_filename,
969     .bdrv_file_open             = curl_open,
970     .bdrv_close                 = curl_close,
971     .bdrv_getlength             = curl_getlength,
972 
973     .bdrv_co_preadv             = curl_co_preadv,
974 
975     .bdrv_detach_aio_context    = curl_detach_aio_context,
976     .bdrv_attach_aio_context    = curl_attach_aio_context,
977 };
978 
979 static BlockDriver bdrv_https = {
980     .format_name                = "https",
981     .protocol_name              = "https",
982 
983     .instance_size              = sizeof(BDRVCURLState),
984     .bdrv_parse_filename        = curl_parse_filename,
985     .bdrv_file_open             = curl_open,
986     .bdrv_close                 = curl_close,
987     .bdrv_getlength             = curl_getlength,
988 
989     .bdrv_co_preadv             = curl_co_preadv,
990 
991     .bdrv_detach_aio_context    = curl_detach_aio_context,
992     .bdrv_attach_aio_context    = curl_attach_aio_context,
993 };
994 
995 static BlockDriver bdrv_ftp = {
996     .format_name                = "ftp",
997     .protocol_name              = "ftp",
998 
999     .instance_size              = sizeof(BDRVCURLState),
1000     .bdrv_parse_filename        = curl_parse_filename,
1001     .bdrv_file_open             = curl_open,
1002     .bdrv_close                 = curl_close,
1003     .bdrv_getlength             = curl_getlength,
1004 
1005     .bdrv_co_preadv             = curl_co_preadv,
1006 
1007     .bdrv_detach_aio_context    = curl_detach_aio_context,
1008     .bdrv_attach_aio_context    = curl_attach_aio_context,
1009 };
1010 
1011 static BlockDriver bdrv_ftps = {
1012     .format_name                = "ftps",
1013     .protocol_name              = "ftps",
1014 
1015     .instance_size              = sizeof(BDRVCURLState),
1016     .bdrv_parse_filename        = curl_parse_filename,
1017     .bdrv_file_open             = curl_open,
1018     .bdrv_close                 = curl_close,
1019     .bdrv_getlength             = curl_getlength,
1020 
1021     .bdrv_co_preadv             = curl_co_preadv,
1022 
1023     .bdrv_detach_aio_context    = curl_detach_aio_context,
1024     .bdrv_attach_aio_context    = curl_attach_aio_context,
1025 };
1026 
1027 static void curl_block_init(void)
1028 {
1029     bdrv_register(&bdrv_http);
1030     bdrv_register(&bdrv_https);
1031     bdrv_register(&bdrv_ftp);
1032     bdrv_register(&bdrv_ftps);
1033 }
1034 
1035 block_init(curl_block_init);
1036