xref: /openbmc/qemu/block/curl.c (revision 2df1eb27)
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 *header = (char *)ptr;
214     const char *end = header + realsize;
215     const char *accept_ranges = "accept-ranges:";
216     const char *bytes = "bytes";
217 
218     if (realsize >= strlen(accept_ranges)
219         && g_ascii_strncasecmp(header, accept_ranges,
220                                strlen(accept_ranges)) == 0) {
221 
222         char *p = strchr(header, ':') + 1;
223 
224         /* Skip whitespace between the header name and value. */
225         while (p < end && *p && g_ascii_isspace(*p)) {
226             p++;
227         }
228 
229         if (end - p >= strlen(bytes)
230             && strncmp(p, bytes, strlen(bytes)) == 0) {
231 
232             /* Check that there is nothing but whitespace after the value. */
233             p += strlen(bytes);
234             while (p < end && *p && g_ascii_isspace(*p)) {
235                 p++;
236             }
237 
238             if (p == end || !*p) {
239                 s->accept_range = true;
240             }
241         }
242     }
243 
244     return realsize;
245 }
246 
247 /* Called from curl_multi_do_locked, with s->mutex held.  */
248 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
249 {
250     CURLState *s = ((CURLState*)opaque);
251     size_t realsize = size * nmemb;
252 
253     trace_curl_read_cb(realsize);
254 
255     if (!s || !s->orig_buf) {
256         goto read_end;
257     }
258 
259     if (s->buf_off >= s->buf_len) {
260         /* buffer full, read nothing */
261         goto read_end;
262     }
263     realsize = MIN(realsize, s->buf_len - s->buf_off);
264     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
265     s->buf_off += realsize;
266 
267 read_end:
268     /* curl will error out if we do not return this value */
269     return size * nmemb;
270 }
271 
272 /* Called with s->mutex held.  */
273 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
274                           CURLAIOCB *acb)
275 {
276     int i;
277     uint64_t end = start + len;
278     uint64_t clamped_end = MIN(end, s->len);
279     uint64_t clamped_len = clamped_end - start;
280 
281     for (i=0; i<CURL_NUM_STATES; i++) {
282         CURLState *state = &s->states[i];
283         uint64_t buf_end = (state->buf_start + state->buf_off);
284         uint64_t buf_fend = (state->buf_start + state->buf_len);
285 
286         if (!state->orig_buf)
287             continue;
288         if (!state->buf_off)
289             continue;
290 
291         // Does the existing buffer cover our section?
292         if ((start >= state->buf_start) &&
293             (start <= buf_end) &&
294             (clamped_end >= state->buf_start) &&
295             (clamped_end <= buf_end))
296         {
297             char *buf = state->orig_buf + (start - state->buf_start);
298 
299             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
300             if (clamped_len < len) {
301                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
302             }
303             acb->ret = 0;
304             return true;
305         }
306 
307         // Wait for unfinished chunks
308         if (state->in_use &&
309             (start >= state->buf_start) &&
310             (start <= buf_fend) &&
311             (clamped_end >= state->buf_start) &&
312             (clamped_end <= buf_fend))
313         {
314             int j;
315 
316             acb->start = start - state->buf_start;
317             acb->end = acb->start + clamped_len;
318 
319             for (j=0; j<CURL_NUM_ACB; j++) {
320                 if (!state->acb[j]) {
321                     state->acb[j] = acb;
322                     return true;
323                 }
324             }
325         }
326     }
327 
328     return false;
329 }
330 
331 /* Called with s->mutex held.  */
332 static void curl_multi_check_completion(BDRVCURLState *s)
333 {
334     int msgs_in_queue;
335 
336     /* Try to find done transfers, so we can free the easy
337      * handle again. */
338     for (;;) {
339         CURLMsg *msg;
340         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
341 
342         /* Quit when there are no more completions */
343         if (!msg)
344             break;
345 
346         if (msg->msg == CURLMSG_DONE) {
347             int i;
348             CURLState *state = NULL;
349             bool error = msg->data.result != CURLE_OK;
350 
351             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
352                               (char **)&state);
353 
354             if (error) {
355                 static int errcount = 100;
356 
357                 /* Don't lose the original error message from curl, since
358                  * it contains extra data.
359                  */
360                 if (errcount > 0) {
361                     error_report("curl: %s", state->errmsg);
362                     if (--errcount == 0) {
363                         error_report("curl: further errors suppressed");
364                     }
365                 }
366             }
367 
368             for (i = 0; i < CURL_NUM_ACB; i++) {
369                 CURLAIOCB *acb = state->acb[i];
370 
371                 if (acb == NULL) {
372                     continue;
373                 }
374 
375                 if (!error) {
376                     /* Assert that we have read all data */
377                     assert(state->buf_off >= acb->end);
378 
379                     qemu_iovec_from_buf(acb->qiov, 0,
380                                         state->orig_buf + acb->start,
381                                         acb->end - acb->start);
382 
383                     if (acb->end - acb->start < acb->bytes) {
384                         size_t offset = acb->end - acb->start;
385                         qemu_iovec_memset(acb->qiov, offset, 0,
386                                           acb->bytes - offset);
387                     }
388                 }
389 
390                 acb->ret = error ? -EIO : 0;
391                 state->acb[i] = NULL;
392                 qemu_mutex_unlock(&s->mutex);
393                 aio_co_wake(acb->co);
394                 qemu_mutex_lock(&s->mutex);
395             }
396 
397             curl_clean_state(state);
398             break;
399         }
400     }
401 }
402 
403 /* Called with s->mutex held.  */
404 static void curl_multi_do_locked(CURLSocket *socket)
405 {
406     BDRVCURLState *s = socket->s;
407     int running;
408     int r;
409 
410     if (!s->multi) {
411         return;
412     }
413 
414     do {
415         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
416     } while (r == CURLM_CALL_MULTI_PERFORM);
417 }
418 
419 static void curl_multi_do(void *arg)
420 {
421     CURLSocket *socket = arg;
422     BDRVCURLState *s = socket->s;
423 
424     qemu_mutex_lock(&s->mutex);
425     curl_multi_do_locked(socket);
426     curl_multi_check_completion(s);
427     qemu_mutex_unlock(&s->mutex);
428 }
429 
430 static void curl_multi_timeout_do(void *arg)
431 {
432     BDRVCURLState *s = (BDRVCURLState *)arg;
433     int running;
434 
435     if (!s->multi) {
436         return;
437     }
438 
439     qemu_mutex_lock(&s->mutex);
440     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
441 
442     curl_multi_check_completion(s);
443     qemu_mutex_unlock(&s->mutex);
444 }
445 
446 /* Called with s->mutex held.  */
447 static CURLState *curl_find_state(BDRVCURLState *s)
448 {
449     CURLState *state = NULL;
450     int i;
451 
452     for (i = 0; i < CURL_NUM_STATES; i++) {
453         if (!s->states[i].in_use) {
454             state = &s->states[i];
455             state->in_use = 1;
456             break;
457         }
458     }
459     return state;
460 }
461 
462 static int curl_init_state(BDRVCURLState *s, CURLState *state)
463 {
464     if (!state->curl) {
465         state->curl = curl_easy_init();
466         if (!state->curl) {
467             return -EIO;
468         }
469         if (curl_easy_setopt(state->curl, CURLOPT_URL, s->url) ||
470             curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
471                              (long) s->sslverify) ||
472             curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
473                              s->sslverify ? 2L : 0L)) {
474             goto err;
475         }
476         if (s->cookie) {
477             if (curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie)) {
478                 goto err;
479             }
480         }
481         if (curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout) ||
482             curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
483                              (void *)curl_read_cb) ||
484             curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state) ||
485             curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state) ||
486             curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1) ||
487             curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1) ||
488             curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1) ||
489             curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg) ||
490             curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1)) {
491             goto err;
492         }
493         if (s->username) {
494             if (curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username)) {
495                 goto err;
496             }
497         }
498         if (s->password) {
499             if (curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password)) {
500                 goto err;
501             }
502         }
503         if (s->proxyusername) {
504             if (curl_easy_setopt(state->curl,
505                                  CURLOPT_PROXYUSERNAME, s->proxyusername)) {
506                 goto err;
507             }
508         }
509         if (s->proxypassword) {
510             if (curl_easy_setopt(state->curl,
511                                  CURLOPT_PROXYPASSWORD, s->proxypassword)) {
512                 goto err;
513             }
514         }
515 
516         /* Restrict supported protocols to avoid security issues in the more
517          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
518          * CVE-2013-0249.
519          *
520          * Restricting protocols is only supported from 7.19.4 upwards. Note:
521          * version 7.85.0 deprecates CURLOPT_*PROTOCOLS in favour of a string
522          * based CURLOPT_*PROTOCOLS_STR API.
523          */
524 #if LIBCURL_VERSION_NUM >= 0x075500
525         if (curl_easy_setopt(state->curl,
526                              CURLOPT_PROTOCOLS_STR, PROTOCOLS) ||
527             curl_easy_setopt(state->curl,
528                              CURLOPT_REDIR_PROTOCOLS_STR, PROTOCOLS)) {
529             goto err;
530         }
531 #elif LIBCURL_VERSION_NUM >= 0x071304
532         if (curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS) ||
533             curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS)) {
534             goto err;
535         }
536 #endif
537 
538 #ifdef DEBUG_VERBOSE
539         if (curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1)) {
540             goto err;
541         }
542 #endif
543     }
544 
545     state->s = s;
546 
547     return 0;
548 
549 err:
550     curl_easy_cleanup(state->curl);
551     state->curl = NULL;
552     return -EIO;
553 }
554 
555 /* Called with s->mutex held.  */
556 static void curl_clean_state(CURLState *s)
557 {
558     int j;
559     for (j = 0; j < CURL_NUM_ACB; j++) {
560         assert(!s->acb[j]);
561     }
562 
563     if (s->s->multi)
564         curl_multi_remove_handle(s->s->multi, s->curl);
565 
566     s->in_use = 0;
567 
568     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
569 }
570 
571 static void curl_parse_filename(const char *filename, QDict *options,
572                                 Error **errp)
573 {
574     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
575 }
576 
577 static void curl_detach_aio_context(BlockDriverState *bs)
578 {
579     BDRVCURLState *s = bs->opaque;
580     int i;
581 
582     WITH_QEMU_LOCK_GUARD(&s->mutex) {
583         curl_drop_all_sockets(s->sockets);
584         for (i = 0; i < CURL_NUM_STATES; i++) {
585             if (s->states[i].in_use) {
586                 curl_clean_state(&s->states[i]);
587             }
588             if (s->states[i].curl) {
589                 curl_easy_cleanup(s->states[i].curl);
590                 s->states[i].curl = NULL;
591             }
592             g_free(s->states[i].orig_buf);
593             s->states[i].orig_buf = NULL;
594         }
595         if (s->multi) {
596             curl_multi_cleanup(s->multi);
597             s->multi = NULL;
598         }
599     }
600 
601     timer_del(&s->timer);
602 }
603 
604 static void curl_attach_aio_context(BlockDriverState *bs,
605                                     AioContext *new_context)
606 {
607     BDRVCURLState *s = bs->opaque;
608 
609     aio_timer_init(new_context, &s->timer,
610                    QEMU_CLOCK_REALTIME, SCALE_NS,
611                    curl_multi_timeout_do, s);
612 
613     assert(!s->multi);
614     s->multi = curl_multi_init();
615     s->aio_context = new_context;
616     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
617     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
618     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
619 }
620 
621 static QemuOptsList runtime_opts = {
622     .name = "curl",
623     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
624     .desc = {
625         {
626             .name = CURL_BLOCK_OPT_URL,
627             .type = QEMU_OPT_STRING,
628             .help = "URL to open",
629         },
630         {
631             .name = CURL_BLOCK_OPT_READAHEAD,
632             .type = QEMU_OPT_SIZE,
633             .help = "Readahead size",
634         },
635         {
636             .name = CURL_BLOCK_OPT_SSLVERIFY,
637             .type = QEMU_OPT_BOOL,
638             .help = "Verify SSL certificate"
639         },
640         {
641             .name = CURL_BLOCK_OPT_TIMEOUT,
642             .type = QEMU_OPT_NUMBER,
643             .help = "Curl timeout"
644         },
645         {
646             .name = CURL_BLOCK_OPT_COOKIE,
647             .type = QEMU_OPT_STRING,
648             .help = "Pass the cookie or list of cookies with each request"
649         },
650         {
651             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
652             .type = QEMU_OPT_STRING,
653             .help = "ID of secret used as cookie passed with each request"
654         },
655         {
656             .name = CURL_BLOCK_OPT_USERNAME,
657             .type = QEMU_OPT_STRING,
658             .help = "Username for HTTP auth"
659         },
660         {
661             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
662             .type = QEMU_OPT_STRING,
663             .help = "ID of secret used as password for HTTP auth",
664         },
665         {
666             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
667             .type = QEMU_OPT_STRING,
668             .help = "Username for HTTP proxy auth"
669         },
670         {
671             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
672             .type = QEMU_OPT_STRING,
673             .help = "ID of secret used as password for HTTP proxy auth",
674         },
675         { /* end of list */ }
676     },
677 };
678 
679 
680 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
681                      Error **errp)
682 {
683     BDRVCURLState *s = bs->opaque;
684     CURLState *state = NULL;
685     QemuOpts *opts;
686     const char *file;
687     const char *cookie;
688     const char *cookie_secret;
689     /* CURL >= 7.55.0 uses curl_off_t for content length instead of a double */
690 #if LIBCURL_VERSION_NUM >= 0x073700
691     curl_off_t cl;
692 #else
693     double cl;
694 #endif
695     const char *secretid;
696     const char *protocol_delimiter;
697     int ret;
698 
699     bdrv_graph_rdlock_main_loop();
700     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
701                                     errp);
702     bdrv_graph_rdunlock_main_loop();
703     if (ret < 0) {
704         return ret;
705     }
706 
707     if (!libcurl_initialized) {
708         ret = curl_global_init(CURL_GLOBAL_ALL);
709         if (ret) {
710             error_setg(errp, "libcurl initialization failed with %d", ret);
711             return -EIO;
712         }
713         libcurl_initialized = true;
714     }
715 
716     qemu_mutex_init(&s->mutex);
717     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
718     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
719         goto out_noclean;
720     }
721 
722     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
723                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
724     if ((s->readahead_size & 0x1ff) != 0) {
725         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
726                    s->readahead_size);
727         goto out_noclean;
728     }
729 
730     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
731                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
732     if (s->timeout > CURL_TIMEOUT_MAX) {
733         error_setg(errp, "timeout parameter is too large or negative");
734         goto out_noclean;
735     }
736 
737     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
738                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
739 
740     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
741     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
742 
743     if (cookie && cookie_secret) {
744         error_setg(errp,
745                    "curl driver cannot handle both cookie and cookie secret");
746         goto out_noclean;
747     }
748 
749     if (cookie_secret) {
750         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
751         if (!s->cookie) {
752             goto out_noclean;
753         }
754     } else {
755         s->cookie = g_strdup(cookie);
756     }
757 
758     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
759     if (file == NULL) {
760         error_setg(errp, "curl block driver requires an 'url' option");
761         goto out_noclean;
762     }
763 
764     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
765         !strstart(protocol_delimiter, "://", NULL))
766     {
767         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
768                    "start with '%s://')", bs->drv->protocol_name, file,
769                    bs->drv->protocol_name);
770         goto out_noclean;
771     }
772 
773     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
774     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
775 
776     if (secretid) {
777         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
778         if (!s->password) {
779             goto out_noclean;
780         }
781     }
782 
783     s->proxyusername = g_strdup(
784         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
785     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
786     if (secretid) {
787         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
788         if (!s->proxypassword) {
789             goto out_noclean;
790         }
791     }
792 
793     trace_curl_open(file);
794     qemu_co_queue_init(&s->free_state_waitq);
795     s->aio_context = bdrv_get_aio_context(bs);
796     s->url = g_strdup(file);
797     s->sockets = g_hash_table_new_full(NULL, NULL, NULL, g_free);
798     qemu_mutex_lock(&s->mutex);
799     state = curl_find_state(s);
800     qemu_mutex_unlock(&s->mutex);
801     if (!state) {
802         goto out_noclean;
803     }
804 
805     // Get file size
806 
807     if (curl_init_state(s, state) < 0) {
808         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
809                 "curl library initialization failed.");
810         goto out;
811     }
812 
813     s->accept_range = false;
814     if (curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1) ||
815         curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION, curl_header_cb) ||
816         curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s)) {
817         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
818                 "curl library initialization failed.");
819         goto out;
820     }
821     if (curl_easy_perform(state->curl))
822         goto out;
823     /* CURL 7.55.0 deprecates CURLINFO_CONTENT_LENGTH_DOWNLOAD in favour of
824      * the *_T version which returns a more sensible type for content length.
825      */
826 #if LIBCURL_VERSION_NUM >= 0x073700
827     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD_T, &cl)) {
828         goto out;
829     }
830 #else
831     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &cl)) {
832         goto out;
833     }
834 #endif
835     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
836      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
837      * known and zero if it is really zero-length file. */
838 #if LIBCURL_VERSION_NUM >= 0x071304
839     if (cl < 0) {
840         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
841                 "Server didn't report file size.");
842         goto out;
843     }
844 #else
845     if (cl <= 0) {
846         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
847                 "Unknown file size or zero-length file.");
848         goto out;
849     }
850 #endif
851 
852     s->len = cl;
853 
854     if ((!strncasecmp(s->url, "http://", strlen("http://"))
855         || !strncasecmp(s->url, "https://", strlen("https://")))
856         && !s->accept_range) {
857         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
858                 "Server does not support 'range' (byte ranges).");
859         goto out;
860     }
861     trace_curl_open_size(s->len);
862 
863     qemu_mutex_lock(&s->mutex);
864     curl_clean_state(state);
865     qemu_mutex_unlock(&s->mutex);
866     curl_easy_cleanup(state->curl);
867     state->curl = NULL;
868 
869     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
870 
871     qemu_opts_del(opts);
872     return 0;
873 
874 out:
875     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
876     curl_easy_cleanup(state->curl);
877     state->curl = NULL;
878 out_noclean:
879     qemu_mutex_destroy(&s->mutex);
880     g_free(s->cookie);
881     g_free(s->url);
882     g_free(s->username);
883     g_free(s->proxyusername);
884     g_free(s->proxypassword);
885     if (s->sockets) {
886         curl_drop_all_sockets(s->sockets);
887         g_hash_table_destroy(s->sockets);
888     }
889     qemu_opts_del(opts);
890     return -EINVAL;
891 }
892 
893 static void coroutine_fn curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
894 {
895     CURLState *state;
896     int running;
897 
898     BDRVCURLState *s = bs->opaque;
899 
900     uint64_t start = acb->offset;
901     uint64_t end;
902 
903     qemu_mutex_lock(&s->mutex);
904 
905     // In case we have the requested data already (e.g. read-ahead),
906     // we can just call the callback and be done.
907     if (curl_find_buf(s, start, acb->bytes, acb)) {
908         goto out;
909     }
910 
911     // No cache found, so let's start a new request
912     for (;;) {
913         state = curl_find_state(s);
914         if (state) {
915             break;
916         }
917         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
918     }
919 
920     if (curl_init_state(s, state) < 0) {
921         curl_clean_state(state);
922         acb->ret = -EIO;
923         goto out;
924     }
925 
926     acb->start = 0;
927     acb->end = MIN(acb->bytes, s->len - start);
928 
929     state->buf_off = 0;
930     g_free(state->orig_buf);
931     state->buf_start = start;
932     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
933     end = start + state->buf_len - 1;
934     state->orig_buf = g_try_malloc(state->buf_len);
935     if (state->buf_len && state->orig_buf == NULL) {
936         curl_clean_state(state);
937         acb->ret = -ENOMEM;
938         goto out;
939     }
940     state->acb[0] = acb;
941 
942     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
943     trace_curl_setup_preadv(acb->bytes, start, state->range);
944     if (curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range) ||
945         curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
946         state->acb[0] = NULL;
947         acb->ret = -EIO;
948 
949         curl_clean_state(state);
950         goto out;
951     }
952 
953     /* Tell curl it needs to kick things off */
954     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
955 
956 out:
957     qemu_mutex_unlock(&s->mutex);
958 }
959 
960 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
961         int64_t offset, int64_t bytes, QEMUIOVector *qiov,
962         BdrvRequestFlags flags)
963 {
964     CURLAIOCB acb = {
965         .co = qemu_coroutine_self(),
966         .ret = -EINPROGRESS,
967         .qiov = qiov,
968         .offset = offset,
969         .bytes = bytes
970     };
971 
972     curl_setup_preadv(bs, &acb);
973     while (acb.ret == -EINPROGRESS) {
974         qemu_coroutine_yield();
975     }
976     return acb.ret;
977 }
978 
979 static void curl_close(BlockDriverState *bs)
980 {
981     BDRVCURLState *s = bs->opaque;
982 
983     trace_curl_close();
984     curl_detach_aio_context(bs);
985     qemu_mutex_destroy(&s->mutex);
986 
987     g_hash_table_destroy(s->sockets);
988     g_free(s->cookie);
989     g_free(s->url);
990     g_free(s->username);
991     g_free(s->proxyusername);
992     g_free(s->proxypassword);
993 }
994 
995 static int64_t coroutine_fn curl_co_getlength(BlockDriverState *bs)
996 {
997     BDRVCURLState *s = bs->opaque;
998     return s->len;
999 }
1000 
1001 static void curl_refresh_filename(BlockDriverState *bs)
1002 {
1003     BDRVCURLState *s = bs->opaque;
1004 
1005     /* "readahead" and "timeout" do not change the guest-visible data,
1006      * so ignore them */
1007     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
1008         s->cookie || s->username || s->password || s->proxyusername ||
1009         s->proxypassword)
1010     {
1011         return;
1012     }
1013 
1014     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
1015 }
1016 
1017 
1018 static const char *const curl_strong_runtime_opts[] = {
1019     CURL_BLOCK_OPT_URL,
1020     CURL_BLOCK_OPT_SSLVERIFY,
1021     CURL_BLOCK_OPT_COOKIE,
1022     CURL_BLOCK_OPT_COOKIE_SECRET,
1023     CURL_BLOCK_OPT_USERNAME,
1024     CURL_BLOCK_OPT_PASSWORD_SECRET,
1025     CURL_BLOCK_OPT_PROXY_USERNAME,
1026     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
1027 
1028     NULL
1029 };
1030 
1031 static BlockDriver bdrv_http = {
1032     .format_name                = "http",
1033     .protocol_name              = "http",
1034 
1035     .instance_size              = sizeof(BDRVCURLState),
1036     .bdrv_parse_filename        = curl_parse_filename,
1037     .bdrv_file_open             = curl_open,
1038     .bdrv_close                 = curl_close,
1039     .bdrv_co_getlength          = curl_co_getlength,
1040 
1041     .bdrv_co_preadv             = curl_co_preadv,
1042 
1043     .bdrv_detach_aio_context    = curl_detach_aio_context,
1044     .bdrv_attach_aio_context    = curl_attach_aio_context,
1045 
1046     .bdrv_refresh_filename      = curl_refresh_filename,
1047     .strong_runtime_opts        = curl_strong_runtime_opts,
1048 };
1049 
1050 static BlockDriver bdrv_https = {
1051     .format_name                = "https",
1052     .protocol_name              = "https",
1053 
1054     .instance_size              = sizeof(BDRVCURLState),
1055     .bdrv_parse_filename        = curl_parse_filename,
1056     .bdrv_file_open             = curl_open,
1057     .bdrv_close                 = curl_close,
1058     .bdrv_co_getlength          = curl_co_getlength,
1059 
1060     .bdrv_co_preadv             = curl_co_preadv,
1061 
1062     .bdrv_detach_aio_context    = curl_detach_aio_context,
1063     .bdrv_attach_aio_context    = curl_attach_aio_context,
1064 
1065     .bdrv_refresh_filename      = curl_refresh_filename,
1066     .strong_runtime_opts        = curl_strong_runtime_opts,
1067 };
1068 
1069 static BlockDriver bdrv_ftp = {
1070     .format_name                = "ftp",
1071     .protocol_name              = "ftp",
1072 
1073     .instance_size              = sizeof(BDRVCURLState),
1074     .bdrv_parse_filename        = curl_parse_filename,
1075     .bdrv_file_open             = curl_open,
1076     .bdrv_close                 = curl_close,
1077     .bdrv_co_getlength          = curl_co_getlength,
1078 
1079     .bdrv_co_preadv             = curl_co_preadv,
1080 
1081     .bdrv_detach_aio_context    = curl_detach_aio_context,
1082     .bdrv_attach_aio_context    = curl_attach_aio_context,
1083 
1084     .bdrv_refresh_filename      = curl_refresh_filename,
1085     .strong_runtime_opts        = curl_strong_runtime_opts,
1086 };
1087 
1088 static BlockDriver bdrv_ftps = {
1089     .format_name                = "ftps",
1090     .protocol_name              = "ftps",
1091 
1092     .instance_size              = sizeof(BDRVCURLState),
1093     .bdrv_parse_filename        = curl_parse_filename,
1094     .bdrv_file_open             = curl_open,
1095     .bdrv_close                 = curl_close,
1096     .bdrv_co_getlength          = curl_co_getlength,
1097 
1098     .bdrv_co_preadv             = curl_co_preadv,
1099 
1100     .bdrv_detach_aio_context    = curl_detach_aio_context,
1101     .bdrv_attach_aio_context    = curl_attach_aio_context,
1102 
1103     .bdrv_refresh_filename      = curl_refresh_filename,
1104     .strong_runtime_opts        = curl_strong_runtime_opts,
1105 };
1106 
1107 static void curl_block_init(void)
1108 {
1109     bdrv_register(&bdrv_http);
1110     bdrv_register(&bdrv_https);
1111     bdrv_register(&bdrv_ftp);
1112     bdrv_register(&bdrv_ftps);
1113 }
1114 
1115 block_init(curl_block_init);
1116