xref: /openbmc/qemu/block/curl.c (revision d84ed5d2)
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/module.h"
29 #include "qemu/option.h"
30 #include "block/block-io.h"
31 #include "block/block_int.h"
32 #include "qapi/qmp/qdict.h"
33 #include "qapi/qmp/qstring.h"
34 #include "crypto/secret.h"
35 #include <curl/curl.h>
36 #include "qemu/cutils.h"
37 #include "trace.h"
38 
39 // #define DEBUG_VERBOSE
40 
41 /* CURL 7.85.0 switches to a string based API for specifying
42  * the desired protocols.
43  */
44 #if LIBCURL_VERSION_NUM >= 0x075500
45 #define PROTOCOLS "HTTP,HTTPS,FTP,FTPS"
46 #else
47 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
48                    CURLPROTO_FTP | CURLPROTO_FTPS)
49 #endif
50 
51 #define CURL_NUM_STATES 8
52 #define CURL_NUM_ACB    8
53 #define CURL_TIMEOUT_MAX 10000
54 
55 #define CURL_BLOCK_OPT_URL       "url"
56 #define CURL_BLOCK_OPT_READAHEAD "readahead"
57 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
58 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
59 #define CURL_BLOCK_OPT_COOKIE    "cookie"
60 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
61 #define CURL_BLOCK_OPT_USERNAME "username"
62 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
63 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
64 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
65 
66 #define CURL_BLOCK_OPT_READAHEAD_DEFAULT (256 * 1024)
67 #define CURL_BLOCK_OPT_SSLVERIFY_DEFAULT true
68 #define CURL_BLOCK_OPT_TIMEOUT_DEFAULT 5
69 
70 struct BDRVCURLState;
71 struct CURLState;
72 
73 static bool libcurl_initialized;
74 
75 typedef struct CURLAIOCB {
76     Coroutine *co;
77     QEMUIOVector *qiov;
78 
79     uint64_t offset;
80     uint64_t bytes;
81     int ret;
82 
83     size_t start;
84     size_t end;
85 } CURLAIOCB;
86 
87 typedef struct CURLSocket {
88     int fd;
89     struct BDRVCURLState *s;
90 } CURLSocket;
91 
92 typedef struct CURLState
93 {
94     struct BDRVCURLState *s;
95     CURLAIOCB *acb[CURL_NUM_ACB];
96     CURL *curl;
97     char *orig_buf;
98     uint64_t buf_start;
99     size_t buf_off;
100     size_t buf_len;
101     char range[128];
102     char errmsg[CURL_ERROR_SIZE];
103     char in_use;
104 } CURLState;
105 
106 typedef struct BDRVCURLState {
107     CURLM *multi;
108     QEMUTimer timer;
109     uint64_t len;
110     CURLState states[CURL_NUM_STATES];
111     GHashTable *sockets; /* GINT_TO_POINTER(fd) -> socket */
112     char *url;
113     size_t readahead_size;
114     bool sslverify;
115     uint64_t timeout;
116     char *cookie;
117     bool accept_range;
118     AioContext *aio_context;
119     QemuMutex mutex;
120     CoQueue free_state_waitq;
121     char *username;
122     char *password;
123     char *proxyusername;
124     char *proxypassword;
125 } BDRVCURLState;
126 
127 static void curl_clean_state(CURLState *s);
128 static void curl_multi_do(void *arg);
129 
130 static gboolean curl_drop_socket(void *key, void *value, void *opaque)
131 {
132     CURLSocket *socket = value;
133     BDRVCURLState *s = socket->s;
134 
135     aio_set_fd_handler(s->aio_context, socket->fd,
136                        NULL, NULL, NULL, NULL, NULL);
137     return true;
138 }
139 
140 static void curl_drop_all_sockets(GHashTable *sockets)
141 {
142     g_hash_table_foreach_remove(sockets, curl_drop_socket, NULL);
143 }
144 
145 /* Called from curl_multi_do_locked, with s->mutex held.  */
146 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
147 {
148     BDRVCURLState *s = opaque;
149 
150     trace_curl_timer_cb(timeout_ms);
151     if (timeout_ms == -1) {
152         timer_del(&s->timer);
153     } else {
154         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
155         timer_mod(&s->timer,
156                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
157     }
158     return 0;
159 }
160 
161 /* Called from curl_multi_do_locked, with s->mutex held.  */
162 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
163                         void *userp, void *sp)
164 {
165     BDRVCURLState *s;
166     CURLState *state = NULL;
167     CURLSocket *socket;
168 
169     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
170     s = state->s;
171 
172     socket = g_hash_table_lookup(s->sockets, GINT_TO_POINTER(fd));
173     if (!socket) {
174         socket = g_new0(CURLSocket, 1);
175         socket->fd = fd;
176         socket->s = s;
177         g_hash_table_insert(s->sockets, GINT_TO_POINTER(fd), socket);
178     }
179 
180     trace_curl_sock_cb(action, (int)fd);
181     switch (action) {
182         case CURL_POLL_IN:
183             aio_set_fd_handler(s->aio_context, fd,
184                                curl_multi_do, NULL, NULL, NULL, socket);
185             break;
186         case CURL_POLL_OUT:
187             aio_set_fd_handler(s->aio_context, fd,
188                                NULL, curl_multi_do, NULL, NULL, socket);
189             break;
190         case CURL_POLL_INOUT:
191             aio_set_fd_handler(s->aio_context, fd,
192                                curl_multi_do, curl_multi_do,
193                                NULL, NULL, socket);
194             break;
195         case CURL_POLL_REMOVE:
196             aio_set_fd_handler(s->aio_context, fd,
197                                NULL, NULL, NULL, NULL, NULL);
198             break;
199     }
200 
201     if (action == CURL_POLL_REMOVE) {
202         g_hash_table_remove(s->sockets, GINT_TO_POINTER(fd));
203     }
204 
205     return 0;
206 }
207 
208 /* Called from curl_multi_do_locked, with s->mutex held.  */
209 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
210 {
211     BDRVCURLState *s = opaque;
212     size_t realsize = size * nmemb;
213     const char *p = ptr;
214     const char *end = p + realsize;
215     const char *t = "accept-ranges : bytes "; /* A lowercase template */
216 
217     /* check if header matches the "t" template */
218     for (;;) {
219         if (*t == ' ') { /* space in t matches any amount of isspace in p */
220             if (p < end && g_ascii_isspace(*p)) {
221                 ++p;
222             } else {
223                 ++t;
224             }
225         } else if (*t && p < end && *t == g_ascii_tolower(*p)) {
226             ++p, ++t;
227         } else {
228             break;
229         }
230     }
231 
232     if (!*t && p == end) { /* if we managed to reach ends of both strings */
233         s->accept_range = true;
234     }
235 
236     return realsize;
237 }
238 
239 /* Called from curl_multi_do_locked, with s->mutex held.  */
240 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
241 {
242     CURLState *s = ((CURLState*)opaque);
243     size_t realsize = size * nmemb;
244 
245     trace_curl_read_cb(realsize);
246 
247     if (!s || !s->orig_buf) {
248         goto read_end;
249     }
250 
251     if (s->buf_off >= s->buf_len) {
252         /* buffer full, read nothing */
253         goto read_end;
254     }
255     realsize = MIN(realsize, s->buf_len - s->buf_off);
256     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
257     s->buf_off += realsize;
258 
259 read_end:
260     /* curl will error out if we do not return this value */
261     return size * nmemb;
262 }
263 
264 /* Called with s->mutex held.  */
265 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
266                           CURLAIOCB *acb)
267 {
268     int i;
269     uint64_t end = start + len;
270     uint64_t clamped_end = MIN(end, s->len);
271     uint64_t clamped_len = clamped_end - start;
272 
273     for (i=0; i<CURL_NUM_STATES; i++) {
274         CURLState *state = &s->states[i];
275         uint64_t buf_end = (state->buf_start + state->buf_off);
276         uint64_t buf_fend = (state->buf_start + state->buf_len);
277 
278         if (!state->orig_buf)
279             continue;
280         if (!state->buf_off)
281             continue;
282 
283         // Does the existing buffer cover our section?
284         if ((start >= state->buf_start) &&
285             (start <= buf_end) &&
286             (clamped_end >= state->buf_start) &&
287             (clamped_end <= buf_end))
288         {
289             char *buf = state->orig_buf + (start - state->buf_start);
290 
291             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
292             if (clamped_len < len) {
293                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
294             }
295             acb->ret = 0;
296             return true;
297         }
298 
299         // Wait for unfinished chunks
300         if (state->in_use &&
301             (start >= state->buf_start) &&
302             (start <= buf_fend) &&
303             (clamped_end >= state->buf_start) &&
304             (clamped_end <= buf_fend))
305         {
306             int j;
307 
308             acb->start = start - state->buf_start;
309             acb->end = acb->start + clamped_len;
310 
311             for (j=0; j<CURL_NUM_ACB; j++) {
312                 if (!state->acb[j]) {
313                     state->acb[j] = acb;
314                     return true;
315                 }
316             }
317         }
318     }
319 
320     return false;
321 }
322 
323 /* Called with s->mutex held.  */
324 static void curl_multi_check_completion(BDRVCURLState *s)
325 {
326     int msgs_in_queue;
327 
328     /* Try to find done transfers, so we can free the easy
329      * handle again. */
330     for (;;) {
331         CURLMsg *msg;
332         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
333 
334         /* Quit when there are no more completions */
335         if (!msg)
336             break;
337 
338         if (msg->msg == CURLMSG_DONE) {
339             int i;
340             CURLState *state = NULL;
341             bool error = msg->data.result != CURLE_OK;
342 
343             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
344                               (char **)&state);
345 
346             if (error) {
347                 static int errcount = 100;
348 
349                 /* Don't lose the original error message from curl, since
350                  * it contains extra data.
351                  */
352                 if (errcount > 0) {
353                     error_report("curl: %s", state->errmsg);
354                     if (--errcount == 0) {
355                         error_report("curl: further errors suppressed");
356                     }
357                 }
358             }
359 
360             for (i = 0; i < CURL_NUM_ACB; i++) {
361                 CURLAIOCB *acb = state->acb[i];
362 
363                 if (acb == NULL) {
364                     continue;
365                 }
366 
367                 if (!error) {
368                     /* Assert that we have read all data */
369                     assert(state->buf_off >= acb->end);
370 
371                     qemu_iovec_from_buf(acb->qiov, 0,
372                                         state->orig_buf + acb->start,
373                                         acb->end - acb->start);
374 
375                     if (acb->end - acb->start < acb->bytes) {
376                         size_t offset = acb->end - acb->start;
377                         qemu_iovec_memset(acb->qiov, offset, 0,
378                                           acb->bytes - offset);
379                     }
380                 }
381 
382                 acb->ret = error ? -EIO : 0;
383                 state->acb[i] = NULL;
384                 qemu_mutex_unlock(&s->mutex);
385                 aio_co_wake(acb->co);
386                 qemu_mutex_lock(&s->mutex);
387             }
388 
389             curl_clean_state(state);
390             break;
391         }
392     }
393 }
394 
395 /* Called with s->mutex held.  */
396 static void curl_multi_do_locked(CURLSocket *socket)
397 {
398     BDRVCURLState *s = socket->s;
399     int running;
400     int r;
401 
402     if (!s->multi) {
403         return;
404     }
405 
406     do {
407         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
408     } while (r == CURLM_CALL_MULTI_PERFORM);
409 }
410 
411 static void curl_multi_do(void *arg)
412 {
413     CURLSocket *socket = arg;
414     BDRVCURLState *s = socket->s;
415 
416     qemu_mutex_lock(&s->mutex);
417     curl_multi_do_locked(socket);
418     curl_multi_check_completion(s);
419     qemu_mutex_unlock(&s->mutex);
420 }
421 
422 static void curl_multi_timeout_do(void *arg)
423 {
424     BDRVCURLState *s = (BDRVCURLState *)arg;
425     int running;
426 
427     if (!s->multi) {
428         return;
429     }
430 
431     qemu_mutex_lock(&s->mutex);
432     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
433 
434     curl_multi_check_completion(s);
435     qemu_mutex_unlock(&s->mutex);
436 }
437 
438 /* Called with s->mutex held.  */
439 static CURLState *curl_find_state(BDRVCURLState *s)
440 {
441     CURLState *state = NULL;
442     int i;
443 
444     for (i = 0; i < CURL_NUM_STATES; i++) {
445         if (!s->states[i].in_use) {
446             state = &s->states[i];
447             state->in_use = 1;
448             break;
449         }
450     }
451     return state;
452 }
453 
454 static int curl_init_state(BDRVCURLState *s, CURLState *state)
455 {
456     if (!state->curl) {
457         state->curl = curl_easy_init();
458         if (!state->curl) {
459             return -EIO;
460         }
461         if (curl_easy_setopt(state->curl, CURLOPT_URL, s->url) ||
462             curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
463                              (long) s->sslverify) ||
464             curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
465                              s->sslverify ? 2L : 0L)) {
466             goto err;
467         }
468         if (s->cookie) {
469             if (curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie)) {
470                 goto err;
471             }
472         }
473         if (curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout) ||
474             curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
475                              (void *)curl_read_cb) ||
476             curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state) ||
477             curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state) ||
478             curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1) ||
479             curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1) ||
480             curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1) ||
481             curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg) ||
482             curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1)) {
483             goto err;
484         }
485         if (s->username) {
486             if (curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username)) {
487                 goto err;
488             }
489         }
490         if (s->password) {
491             if (curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password)) {
492                 goto err;
493             }
494         }
495         if (s->proxyusername) {
496             if (curl_easy_setopt(state->curl,
497                                  CURLOPT_PROXYUSERNAME, s->proxyusername)) {
498                 goto err;
499             }
500         }
501         if (s->proxypassword) {
502             if (curl_easy_setopt(state->curl,
503                                  CURLOPT_PROXYPASSWORD, s->proxypassword)) {
504                 goto err;
505             }
506         }
507 
508         /* Restrict supported protocols to avoid security issues in the more
509          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
510          * CVE-2013-0249.
511          *
512          * Restricting protocols is only supported from 7.19.4 upwards. Note:
513          * version 7.85.0 deprecates CURLOPT_*PROTOCOLS in favour of a string
514          * based CURLOPT_*PROTOCOLS_STR API.
515          */
516 #if LIBCURL_VERSION_NUM >= 0x075500
517         if (curl_easy_setopt(state->curl,
518                              CURLOPT_PROTOCOLS_STR, PROTOCOLS) ||
519             curl_easy_setopt(state->curl,
520                              CURLOPT_REDIR_PROTOCOLS_STR, PROTOCOLS)) {
521             goto err;
522         }
523 #elif LIBCURL_VERSION_NUM >= 0x071304
524         if (curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS) ||
525             curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS)) {
526             goto err;
527         }
528 #endif
529 
530 #ifdef DEBUG_VERBOSE
531         if (curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1)) {
532             goto err;
533         }
534 #endif
535     }
536 
537     state->s = s;
538 
539     return 0;
540 
541 err:
542     curl_easy_cleanup(state->curl);
543     state->curl = NULL;
544     return -EIO;
545 }
546 
547 /* Called with s->mutex held.  */
548 static void curl_clean_state(CURLState *s)
549 {
550     int j;
551     for (j = 0; j < CURL_NUM_ACB; j++) {
552         assert(!s->acb[j]);
553     }
554 
555     if (s->s->multi)
556         curl_multi_remove_handle(s->s->multi, s->curl);
557 
558     s->in_use = 0;
559 
560     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
561 }
562 
563 static void curl_parse_filename(const char *filename, QDict *options,
564                                 Error **errp)
565 {
566     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
567 }
568 
569 static void curl_detach_aio_context(BlockDriverState *bs)
570 {
571     BDRVCURLState *s = bs->opaque;
572     int i;
573 
574     WITH_QEMU_LOCK_GUARD(&s->mutex) {
575         curl_drop_all_sockets(s->sockets);
576         for (i = 0; i < CURL_NUM_STATES; i++) {
577             if (s->states[i].in_use) {
578                 curl_clean_state(&s->states[i]);
579             }
580             if (s->states[i].curl) {
581                 curl_easy_cleanup(s->states[i].curl);
582                 s->states[i].curl = NULL;
583             }
584             g_free(s->states[i].orig_buf);
585             s->states[i].orig_buf = NULL;
586         }
587         if (s->multi) {
588             curl_multi_cleanup(s->multi);
589             s->multi = NULL;
590         }
591     }
592 
593     timer_del(&s->timer);
594 }
595 
596 static void curl_attach_aio_context(BlockDriverState *bs,
597                                     AioContext *new_context)
598 {
599     BDRVCURLState *s = bs->opaque;
600 
601     aio_timer_init(new_context, &s->timer,
602                    QEMU_CLOCK_REALTIME, SCALE_NS,
603                    curl_multi_timeout_do, s);
604 
605     assert(!s->multi);
606     s->multi = curl_multi_init();
607     s->aio_context = new_context;
608     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
609     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
610     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
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     const char *file;
679     const char *cookie;
680     const char *cookie_secret;
681     /* CURL >= 7.55.0 uses curl_off_t for content length instead of a double */
682 #if LIBCURL_VERSION_NUM >= 0x073700
683     curl_off_t cl;
684 #else
685     double cl;
686 #endif
687     const char *secretid;
688     const char *protocol_delimiter;
689     int ret;
690 
691     bdrv_graph_rdlock_main_loop();
692     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
693                                     errp);
694     bdrv_graph_rdunlock_main_loop();
695     if (ret < 0) {
696         return ret;
697     }
698 
699     if (!libcurl_initialized) {
700         ret = curl_global_init(CURL_GLOBAL_ALL);
701         if (ret) {
702             error_setg(errp, "libcurl initialization failed with %d", ret);
703             return -EIO;
704         }
705         libcurl_initialized = true;
706     }
707 
708     qemu_mutex_init(&s->mutex);
709     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
710     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
711         goto out_noclean;
712     }
713 
714     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
715                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
716     if ((s->readahead_size & 0x1ff) != 0) {
717         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
718                    s->readahead_size);
719         goto out_noclean;
720     }
721 
722     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
723                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
724     if (s->timeout > CURL_TIMEOUT_MAX) {
725         error_setg(errp, "timeout parameter is too large or negative");
726         goto out_noclean;
727     }
728 
729     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
730                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
731 
732     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
733     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
734 
735     if (cookie && cookie_secret) {
736         error_setg(errp,
737                    "curl driver cannot handle both cookie and cookie secret");
738         goto out_noclean;
739     }
740 
741     if (cookie_secret) {
742         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
743         if (!s->cookie) {
744             goto out_noclean;
745         }
746     } else {
747         s->cookie = g_strdup(cookie);
748     }
749 
750     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
751     if (file == NULL) {
752         error_setg(errp, "curl block driver requires an 'url' option");
753         goto out_noclean;
754     }
755 
756     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
757         !strstart(protocol_delimiter, "://", NULL))
758     {
759         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
760                    "start with '%s://')", bs->drv->protocol_name, file,
761                    bs->drv->protocol_name);
762         goto out_noclean;
763     }
764 
765     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
766     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
767 
768     if (secretid) {
769         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
770         if (!s->password) {
771             goto out_noclean;
772         }
773     }
774 
775     s->proxyusername = g_strdup(
776         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
777     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
778     if (secretid) {
779         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
780         if (!s->proxypassword) {
781             goto out_noclean;
782         }
783     }
784 
785     trace_curl_open(file);
786     qemu_co_queue_init(&s->free_state_waitq);
787     s->aio_context = bdrv_get_aio_context(bs);
788     s->url = g_strdup(file);
789     s->sockets = g_hash_table_new_full(NULL, NULL, NULL, g_free);
790     qemu_mutex_lock(&s->mutex);
791     state = curl_find_state(s);
792     qemu_mutex_unlock(&s->mutex);
793     if (!state) {
794         goto out_noclean;
795     }
796 
797     // Get file size
798 
799     if (curl_init_state(s, state) < 0) {
800         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
801                 "curl library initialization failed.");
802         goto out;
803     }
804 
805     s->accept_range = false;
806     if (curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1) ||
807         curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION, curl_header_cb) ||
808         curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s)) {
809         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
810                 "curl library initialization failed.");
811         goto out;
812     }
813     if (curl_easy_perform(state->curl))
814         goto out;
815     /* CURL 7.55.0 deprecates CURLINFO_CONTENT_LENGTH_DOWNLOAD in favour of
816      * the *_T version which returns a more sensible type for content length.
817      */
818 #if LIBCURL_VERSION_NUM >= 0x073700
819     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD_T, &cl)) {
820         goto out;
821     }
822 #else
823     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &cl)) {
824         goto out;
825     }
826 #endif
827     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
828      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
829      * known and zero if it is really zero-length file. */
830 #if LIBCURL_VERSION_NUM >= 0x071304
831     if (cl < 0) {
832         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
833                 "Server didn't report file size.");
834         goto out;
835     }
836 #else
837     if (cl <= 0) {
838         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
839                 "Unknown file size or zero-length file.");
840         goto out;
841     }
842 #endif
843 
844     s->len = cl;
845 
846     if ((!strncasecmp(s->url, "http://", strlen("http://"))
847         || !strncasecmp(s->url, "https://", strlen("https://")))
848         && !s->accept_range) {
849         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
850                 "Server does not support 'range' (byte ranges).");
851         goto out;
852     }
853     trace_curl_open_size(s->len);
854 
855     qemu_mutex_lock(&s->mutex);
856     curl_clean_state(state);
857     qemu_mutex_unlock(&s->mutex);
858     curl_easy_cleanup(state->curl);
859     state->curl = NULL;
860 
861     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
862 
863     qemu_opts_del(opts);
864     return 0;
865 
866 out:
867     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
868     curl_easy_cleanup(state->curl);
869     state->curl = NULL;
870 out_noclean:
871     qemu_mutex_destroy(&s->mutex);
872     g_free(s->cookie);
873     g_free(s->url);
874     g_free(s->username);
875     g_free(s->proxyusername);
876     g_free(s->proxypassword);
877     if (s->sockets) {
878         curl_drop_all_sockets(s->sockets);
879         g_hash_table_destroy(s->sockets);
880     }
881     qemu_opts_del(opts);
882     return -EINVAL;
883 }
884 
885 static void coroutine_fn curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
886 {
887     CURLState *state;
888     int running;
889 
890     BDRVCURLState *s = bs->opaque;
891 
892     uint64_t start = acb->offset;
893     uint64_t end;
894 
895     qemu_mutex_lock(&s->mutex);
896 
897     // In case we have the requested data already (e.g. read-ahead),
898     // we can just call the callback and be done.
899     if (curl_find_buf(s, start, acb->bytes, acb)) {
900         goto out;
901     }
902 
903     // No cache found, so let's start a new request
904     for (;;) {
905         state = curl_find_state(s);
906         if (state) {
907             break;
908         }
909         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
910     }
911 
912     if (curl_init_state(s, state) < 0) {
913         curl_clean_state(state);
914         acb->ret = -EIO;
915         goto out;
916     }
917 
918     acb->start = 0;
919     acb->end = MIN(acb->bytes, s->len - start);
920 
921     state->buf_off = 0;
922     g_free(state->orig_buf);
923     state->buf_start = start;
924     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
925     end = start + state->buf_len - 1;
926     state->orig_buf = g_try_malloc(state->buf_len);
927     if (state->buf_len && state->orig_buf == NULL) {
928         curl_clean_state(state);
929         acb->ret = -ENOMEM;
930         goto out;
931     }
932     state->acb[0] = acb;
933 
934     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
935     trace_curl_setup_preadv(acb->bytes, start, state->range);
936     if (curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range) ||
937         curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
938         state->acb[0] = NULL;
939         acb->ret = -EIO;
940 
941         curl_clean_state(state);
942         goto out;
943     }
944 
945     /* Tell curl it needs to kick things off */
946     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
947 
948 out:
949     qemu_mutex_unlock(&s->mutex);
950 }
951 
952 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
953         int64_t offset, int64_t bytes, QEMUIOVector *qiov,
954         BdrvRequestFlags flags)
955 {
956     CURLAIOCB acb = {
957         .co = qemu_coroutine_self(),
958         .ret = -EINPROGRESS,
959         .qiov = qiov,
960         .offset = offset,
961         .bytes = bytes
962     };
963 
964     curl_setup_preadv(bs, &acb);
965     while (acb.ret == -EINPROGRESS) {
966         qemu_coroutine_yield();
967     }
968     return acb.ret;
969 }
970 
971 static void curl_close(BlockDriverState *bs)
972 {
973     BDRVCURLState *s = bs->opaque;
974 
975     trace_curl_close();
976     curl_detach_aio_context(bs);
977     qemu_mutex_destroy(&s->mutex);
978 
979     g_hash_table_destroy(s->sockets);
980     g_free(s->cookie);
981     g_free(s->url);
982     g_free(s->username);
983     g_free(s->proxyusername);
984     g_free(s->proxypassword);
985 }
986 
987 static int64_t coroutine_fn curl_co_getlength(BlockDriverState *bs)
988 {
989     BDRVCURLState *s = bs->opaque;
990     return s->len;
991 }
992 
993 static void curl_refresh_filename(BlockDriverState *bs)
994 {
995     BDRVCURLState *s = bs->opaque;
996 
997     /* "readahead" and "timeout" do not change the guest-visible data,
998      * so ignore them */
999     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
1000         s->cookie || s->username || s->password || s->proxyusername ||
1001         s->proxypassword)
1002     {
1003         return;
1004     }
1005 
1006     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
1007 }
1008 
1009 
1010 static const char *const curl_strong_runtime_opts[] = {
1011     CURL_BLOCK_OPT_URL,
1012     CURL_BLOCK_OPT_SSLVERIFY,
1013     CURL_BLOCK_OPT_COOKIE,
1014     CURL_BLOCK_OPT_COOKIE_SECRET,
1015     CURL_BLOCK_OPT_USERNAME,
1016     CURL_BLOCK_OPT_PASSWORD_SECRET,
1017     CURL_BLOCK_OPT_PROXY_USERNAME,
1018     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
1019 
1020     NULL
1021 };
1022 
1023 static BlockDriver bdrv_http = {
1024     .format_name                = "http",
1025     .protocol_name              = "http",
1026 
1027     .instance_size              = sizeof(BDRVCURLState),
1028     .bdrv_parse_filename        = curl_parse_filename,
1029     .bdrv_open                  = curl_open,
1030     .bdrv_close                 = curl_close,
1031     .bdrv_co_getlength          = curl_co_getlength,
1032 
1033     .bdrv_co_preadv             = curl_co_preadv,
1034 
1035     .bdrv_detach_aio_context    = curl_detach_aio_context,
1036     .bdrv_attach_aio_context    = curl_attach_aio_context,
1037 
1038     .bdrv_refresh_filename      = curl_refresh_filename,
1039     .strong_runtime_opts        = curl_strong_runtime_opts,
1040 };
1041 
1042 static BlockDriver bdrv_https = {
1043     .format_name                = "https",
1044     .protocol_name              = "https",
1045 
1046     .instance_size              = sizeof(BDRVCURLState),
1047     .bdrv_parse_filename        = curl_parse_filename,
1048     .bdrv_open                  = curl_open,
1049     .bdrv_close                 = curl_close,
1050     .bdrv_co_getlength          = curl_co_getlength,
1051 
1052     .bdrv_co_preadv             = curl_co_preadv,
1053 
1054     .bdrv_detach_aio_context    = curl_detach_aio_context,
1055     .bdrv_attach_aio_context    = curl_attach_aio_context,
1056 
1057     .bdrv_refresh_filename      = curl_refresh_filename,
1058     .strong_runtime_opts        = curl_strong_runtime_opts,
1059 };
1060 
1061 static BlockDriver bdrv_ftp = {
1062     .format_name                = "ftp",
1063     .protocol_name              = "ftp",
1064 
1065     .instance_size              = sizeof(BDRVCURLState),
1066     .bdrv_parse_filename        = curl_parse_filename,
1067     .bdrv_open                  = curl_open,
1068     .bdrv_close                 = curl_close,
1069     .bdrv_co_getlength          = curl_co_getlength,
1070 
1071     .bdrv_co_preadv             = curl_co_preadv,
1072 
1073     .bdrv_detach_aio_context    = curl_detach_aio_context,
1074     .bdrv_attach_aio_context    = curl_attach_aio_context,
1075 
1076     .bdrv_refresh_filename      = curl_refresh_filename,
1077     .strong_runtime_opts        = curl_strong_runtime_opts,
1078 };
1079 
1080 static BlockDriver bdrv_ftps = {
1081     .format_name                = "ftps",
1082     .protocol_name              = "ftps",
1083 
1084     .instance_size              = sizeof(BDRVCURLState),
1085     .bdrv_parse_filename        = curl_parse_filename,
1086     .bdrv_open                  = curl_open,
1087     .bdrv_close                 = curl_close,
1088     .bdrv_co_getlength          = curl_co_getlength,
1089 
1090     .bdrv_co_preadv             = curl_co_preadv,
1091 
1092     .bdrv_detach_aio_context    = curl_detach_aio_context,
1093     .bdrv_attach_aio_context    = curl_attach_aio_context,
1094 
1095     .bdrv_refresh_filename      = curl_refresh_filename,
1096     .strong_runtime_opts        = curl_strong_runtime_opts,
1097 };
1098 
1099 static void curl_block_init(void)
1100 {
1101     bdrv_register(&bdrv_http);
1102     bdrv_register(&bdrv_https);
1103     bdrv_register(&bdrv_ftp);
1104     bdrv_register(&bdrv_ftps);
1105 }
1106 
1107 block_init(curl_block_init);
1108