xref: /openbmc/qemu/block/curl.c (revision ed5abf46)
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_int.h"
31 #include "qapi/qmp/qdict.h"
32 #include "qapi/qmp/qstring.h"
33 #include "crypto/secret.h"
34 #include <curl/curl.h>
35 #include "qemu/cutils.h"
36 #include "trace.h"
37 
38 // #define DEBUG_VERBOSE
39 
40 #if LIBCURL_VERSION_NUM >= 0x071000
41 /* The multi interface timer callback was introduced in 7.16.0 */
42 #define NEED_CURL_TIMER_CALLBACK
43 #define HAVE_SOCKET_ACTION
44 #endif
45 
46 #ifndef HAVE_SOCKET_ACTION
47 /* If curl_multi_socket_action isn't available, define it statically here in
48  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
49  * less efficient but still safe. */
50 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
51                                             curl_socket_t sockfd,
52                                             int ev_bitmask,
53                                             int *running_handles)
54 {
55     return curl_multi_socket(multi_handle, sockfd, running_handles);
56 }
57 #define curl_multi_socket_action __curl_multi_socket_action
58 #endif
59 
60 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
61                    CURLPROTO_FTP | CURLPROTO_FTPS)
62 
63 #define CURL_NUM_STATES 8
64 #define CURL_NUM_ACB    8
65 #define CURL_TIMEOUT_MAX 10000
66 
67 #define CURL_BLOCK_OPT_URL       "url"
68 #define CURL_BLOCK_OPT_READAHEAD "readahead"
69 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
70 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
71 #define CURL_BLOCK_OPT_COOKIE    "cookie"
72 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
73 #define CURL_BLOCK_OPT_USERNAME "username"
74 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
75 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
76 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
77 
78 #define CURL_BLOCK_OPT_READAHEAD_DEFAULT (256 * 1024)
79 #define CURL_BLOCK_OPT_SSLVERIFY_DEFAULT true
80 #define CURL_BLOCK_OPT_TIMEOUT_DEFAULT 5
81 
82 struct BDRVCURLState;
83 struct CURLState;
84 
85 static bool libcurl_initialized;
86 
87 typedef struct CURLAIOCB {
88     Coroutine *co;
89     QEMUIOVector *qiov;
90 
91     uint64_t offset;
92     uint64_t bytes;
93     int ret;
94 
95     size_t start;
96     size_t end;
97 } CURLAIOCB;
98 
99 typedef struct CURLSocket {
100     int fd;
101     struct CURLState *state;
102     QLIST_ENTRY(CURLSocket) next;
103 } CURLSocket;
104 
105 typedef struct CURLState
106 {
107     struct BDRVCURLState *s;
108     CURLAIOCB *acb[CURL_NUM_ACB];
109     CURL *curl;
110     QLIST_HEAD(, CURLSocket) sockets;
111     char *orig_buf;
112     uint64_t buf_start;
113     size_t buf_off;
114     size_t buf_len;
115     char range[128];
116     char errmsg[CURL_ERROR_SIZE];
117     char in_use;
118 } CURLState;
119 
120 typedef struct BDRVCURLState {
121     CURLM *multi;
122     QEMUTimer timer;
123     uint64_t len;
124     CURLState states[CURL_NUM_STATES];
125     char *url;
126     size_t readahead_size;
127     bool sslverify;
128     uint64_t timeout;
129     char *cookie;
130     bool accept_range;
131     AioContext *aio_context;
132     QemuMutex mutex;
133     CoQueue free_state_waitq;
134     char *username;
135     char *password;
136     char *proxyusername;
137     char *proxypassword;
138 } BDRVCURLState;
139 
140 static void curl_clean_state(CURLState *s);
141 static void curl_multi_do(void *arg);
142 
143 #ifdef NEED_CURL_TIMER_CALLBACK
144 /* Called from curl_multi_do_locked, with s->mutex held.  */
145 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
146 {
147     BDRVCURLState *s = opaque;
148 
149     trace_curl_timer_cb(timeout_ms);
150     if (timeout_ms == -1) {
151         timer_del(&s->timer);
152     } else {
153         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
154         timer_mod(&s->timer,
155                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
156     }
157     return 0;
158 }
159 #endif
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     QLIST_FOREACH(socket, &state->sockets, next) {
173         if (socket->fd == fd) {
174             break;
175         }
176     }
177     if (!socket) {
178         socket = g_new0(CURLSocket, 1);
179         socket->fd = fd;
180         socket->state = state;
181         QLIST_INSERT_HEAD(&state->sockets, socket, next);
182     }
183 
184     trace_curl_sock_cb(action, (int)fd);
185     switch (action) {
186         case CURL_POLL_IN:
187             aio_set_fd_handler(s->aio_context, fd, false,
188                                curl_multi_do, NULL, NULL, socket);
189             break;
190         case CURL_POLL_OUT:
191             aio_set_fd_handler(s->aio_context, fd, false,
192                                NULL, curl_multi_do, NULL, socket);
193             break;
194         case CURL_POLL_INOUT:
195             aio_set_fd_handler(s->aio_context, fd, false,
196                                curl_multi_do, curl_multi_do, NULL, socket);
197             break;
198         case CURL_POLL_REMOVE:
199             aio_set_fd_handler(s->aio_context, fd, false,
200                                NULL, NULL, NULL, NULL);
201             break;
202     }
203 
204     if (action == CURL_POLL_REMOVE) {
205         QLIST_REMOVE(socket, next);
206         g_free(socket);
207     }
208 
209     return 0;
210 }
211 
212 /* Called from curl_multi_do_locked, with s->mutex held.  */
213 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
214 {
215     BDRVCURLState *s = opaque;
216     size_t realsize = size * nmemb;
217     const char *header = (char *)ptr;
218     const char *end = header + realsize;
219     const char *accept_ranges = "accept-ranges:";
220     const char *bytes = "bytes";
221 
222     if (realsize >= strlen(accept_ranges)
223         && g_ascii_strncasecmp(header, accept_ranges,
224                                strlen(accept_ranges)) == 0) {
225 
226         char *p = strchr(header, ':') + 1;
227 
228         /* Skip whitespace between the header name and value. */
229         while (p < end && *p && g_ascii_isspace(*p)) {
230             p++;
231         }
232 
233         if (end - p >= strlen(bytes)
234             && strncmp(p, bytes, strlen(bytes)) == 0) {
235 
236             /* Check that there is nothing but whitespace after the value. */
237             p += strlen(bytes);
238             while (p < end && *p && g_ascii_isspace(*p)) {
239                 p++;
240             }
241 
242             if (p == end || !*p) {
243                 s->accept_range = true;
244             }
245         }
246     }
247 
248     return realsize;
249 }
250 
251 /* Called from curl_multi_do_locked, with s->mutex held.  */
252 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
253 {
254     CURLState *s = ((CURLState*)opaque);
255     size_t realsize = size * nmemb;
256 
257     trace_curl_read_cb(realsize);
258 
259     if (!s || !s->orig_buf) {
260         goto read_end;
261     }
262 
263     if (s->buf_off >= s->buf_len) {
264         /* buffer full, read nothing */
265         goto read_end;
266     }
267     realsize = MIN(realsize, s->buf_len - s->buf_off);
268     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
269     s->buf_off += realsize;
270 
271 read_end:
272     /* curl will error out if we do not return this value */
273     return size * nmemb;
274 }
275 
276 /* Called with s->mutex held.  */
277 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
278                           CURLAIOCB *acb)
279 {
280     int i;
281     uint64_t end = start + len;
282     uint64_t clamped_end = MIN(end, s->len);
283     uint64_t clamped_len = clamped_end - start;
284 
285     for (i=0; i<CURL_NUM_STATES; i++) {
286         CURLState *state = &s->states[i];
287         uint64_t buf_end = (state->buf_start + state->buf_off);
288         uint64_t buf_fend = (state->buf_start + state->buf_len);
289 
290         if (!state->orig_buf)
291             continue;
292         if (!state->buf_off)
293             continue;
294 
295         // Does the existing buffer cover our section?
296         if ((start >= state->buf_start) &&
297             (start <= buf_end) &&
298             (clamped_end >= state->buf_start) &&
299             (clamped_end <= buf_end))
300         {
301             char *buf = state->orig_buf + (start - state->buf_start);
302 
303             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
304             if (clamped_len < len) {
305                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
306             }
307             acb->ret = 0;
308             return true;
309         }
310 
311         // Wait for unfinished chunks
312         if (state->in_use &&
313             (start >= state->buf_start) &&
314             (start <= buf_fend) &&
315             (clamped_end >= state->buf_start) &&
316             (clamped_end <= buf_fend))
317         {
318             int j;
319 
320             acb->start = start - state->buf_start;
321             acb->end = acb->start + clamped_len;
322 
323             for (j=0; j<CURL_NUM_ACB; j++) {
324                 if (!state->acb[j]) {
325                     state->acb[j] = acb;
326                     return true;
327                 }
328             }
329         }
330     }
331 
332     return false;
333 }
334 
335 /* Called with s->mutex held.  */
336 static void curl_multi_check_completion(BDRVCURLState *s)
337 {
338     int msgs_in_queue;
339 
340     /* Try to find done transfers, so we can free the easy
341      * handle again. */
342     for (;;) {
343         CURLMsg *msg;
344         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
345 
346         /* Quit when there are no more completions */
347         if (!msg)
348             break;
349 
350         if (msg->msg == CURLMSG_DONE) {
351             int i;
352             CURLState *state = NULL;
353             bool error = msg->data.result != CURLE_OK;
354 
355             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
356                               (char **)&state);
357 
358             if (error) {
359                 static int errcount = 100;
360 
361                 /* Don't lose the original error message from curl, since
362                  * it contains extra data.
363                  */
364                 if (errcount > 0) {
365                     error_report("curl: %s", state->errmsg);
366                     if (--errcount == 0) {
367                         error_report("curl: further errors suppressed");
368                     }
369                 }
370             }
371 
372             for (i = 0; i < CURL_NUM_ACB; i++) {
373                 CURLAIOCB *acb = state->acb[i];
374 
375                 if (acb == NULL) {
376                     continue;
377                 }
378 
379                 if (!error) {
380                     /* Assert that we have read all data */
381                     assert(state->buf_off >= acb->end);
382 
383                     qemu_iovec_from_buf(acb->qiov, 0,
384                                         state->orig_buf + acb->start,
385                                         acb->end - acb->start);
386 
387                     if (acb->end - acb->start < acb->bytes) {
388                         size_t offset = acb->end - acb->start;
389                         qemu_iovec_memset(acb->qiov, offset, 0,
390                                           acb->bytes - offset);
391                     }
392                 }
393 
394                 acb->ret = error ? -EIO : 0;
395                 state->acb[i] = NULL;
396                 qemu_mutex_unlock(&s->mutex);
397                 aio_co_wake(acb->co);
398                 qemu_mutex_lock(&s->mutex);
399             }
400 
401             curl_clean_state(state);
402             break;
403         }
404     }
405 }
406 
407 /* Called with s->mutex held.  */
408 static void curl_multi_do_locked(CURLSocket *socket)
409 {
410     BDRVCURLState *s = socket->state->s;
411     int running;
412     int r;
413 
414     if (!s->multi) {
415         return;
416     }
417 
418     do {
419         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
420     } while (r == CURLM_CALL_MULTI_PERFORM);
421 }
422 
423 static void curl_multi_do(void *arg)
424 {
425     CURLSocket *socket = arg;
426     BDRVCURLState *s = socket->state->s;
427 
428     qemu_mutex_lock(&s->mutex);
429     curl_multi_do_locked(socket);
430     curl_multi_check_completion(s);
431     qemu_mutex_unlock(&s->mutex);
432 }
433 
434 static void curl_multi_timeout_do(void *arg)
435 {
436 #ifdef NEED_CURL_TIMER_CALLBACK
437     BDRVCURLState *s = (BDRVCURLState *)arg;
438     int running;
439 
440     if (!s->multi) {
441         return;
442     }
443 
444     qemu_mutex_lock(&s->mutex);
445     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
446 
447     curl_multi_check_completion(s);
448     qemu_mutex_unlock(&s->mutex);
449 #else
450     abort();
451 #endif
452 }
453 
454 /* Called with s->mutex held.  */
455 static CURLState *curl_find_state(BDRVCURLState *s)
456 {
457     CURLState *state = NULL;
458     int i;
459 
460     for (i = 0; i < CURL_NUM_STATES; i++) {
461         if (!s->states[i].in_use) {
462             state = &s->states[i];
463             state->in_use = 1;
464             break;
465         }
466     }
467     return state;
468 }
469 
470 static int curl_init_state(BDRVCURLState *s, CURLState *state)
471 {
472     if (!state->curl) {
473         state->curl = curl_easy_init();
474         if (!state->curl) {
475             return -EIO;
476         }
477         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
478         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
479                          (long) s->sslverify);
480         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
481                          s->sslverify ? 2L : 0L);
482         if (s->cookie) {
483             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
484         }
485         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
486         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
487                          (void *)curl_read_cb);
488         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
489         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
490         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
491         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
492         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
493         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
494         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
495 
496         if (s->username) {
497             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
498         }
499         if (s->password) {
500             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
501         }
502         if (s->proxyusername) {
503             curl_easy_setopt(state->curl,
504                              CURLOPT_PROXYUSERNAME, s->proxyusername);
505         }
506         if (s->proxypassword) {
507             curl_easy_setopt(state->curl,
508                              CURLOPT_PROXYPASSWORD, s->proxypassword);
509         }
510 
511         /* Restrict supported protocols to avoid security issues in the more
512          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
513          * CVE-2013-0249.
514          *
515          * Restricting protocols is only supported from 7.19.4 upwards.
516          */
517 #if LIBCURL_VERSION_NUM >= 0x071304
518         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
519         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
520 #endif
521 
522 #ifdef DEBUG_VERBOSE
523         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
524 #endif
525     }
526 
527     QLIST_INIT(&state->sockets);
528     state->s = s;
529 
530     return 0;
531 }
532 
533 /* Called with s->mutex held.  */
534 static void curl_clean_state(CURLState *s)
535 {
536     int j;
537     for (j = 0; j < CURL_NUM_ACB; j++) {
538         assert(!s->acb[j]);
539     }
540 
541     if (s->s->multi)
542         curl_multi_remove_handle(s->s->multi, s->curl);
543 
544     while (!QLIST_EMPTY(&s->sockets)) {
545         CURLSocket *socket = QLIST_FIRST(&s->sockets);
546 
547         QLIST_REMOVE(socket, next);
548         g_free(socket);
549     }
550 
551     s->in_use = 0;
552 
553     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
554 }
555 
556 static void curl_parse_filename(const char *filename, QDict *options,
557                                 Error **errp)
558 {
559     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
560 }
561 
562 static void curl_detach_aio_context(BlockDriverState *bs)
563 {
564     BDRVCURLState *s = bs->opaque;
565     int i;
566 
567     qemu_mutex_lock(&s->mutex);
568     for (i = 0; i < CURL_NUM_STATES; i++) {
569         if (s->states[i].in_use) {
570             curl_clean_state(&s->states[i]);
571         }
572         if (s->states[i].curl) {
573             curl_easy_cleanup(s->states[i].curl);
574             s->states[i].curl = NULL;
575         }
576         g_free(s->states[i].orig_buf);
577         s->states[i].orig_buf = NULL;
578     }
579     if (s->multi) {
580         curl_multi_cleanup(s->multi);
581         s->multi = NULL;
582     }
583     qemu_mutex_unlock(&s->mutex);
584 
585     timer_del(&s->timer);
586 }
587 
588 static void curl_attach_aio_context(BlockDriverState *bs,
589                                     AioContext *new_context)
590 {
591     BDRVCURLState *s = bs->opaque;
592 
593     aio_timer_init(new_context, &s->timer,
594                    QEMU_CLOCK_REALTIME, SCALE_NS,
595                    curl_multi_timeout_do, s);
596 
597     assert(!s->multi);
598     s->multi = curl_multi_init();
599     s->aio_context = new_context;
600     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
601 #ifdef NEED_CURL_TIMER_CALLBACK
602     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
603     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
604 #endif
605 }
606 
607 static QemuOptsList runtime_opts = {
608     .name = "curl",
609     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
610     .desc = {
611         {
612             .name = CURL_BLOCK_OPT_URL,
613             .type = QEMU_OPT_STRING,
614             .help = "URL to open",
615         },
616         {
617             .name = CURL_BLOCK_OPT_READAHEAD,
618             .type = QEMU_OPT_SIZE,
619             .help = "Readahead size",
620         },
621         {
622             .name = CURL_BLOCK_OPT_SSLVERIFY,
623             .type = QEMU_OPT_BOOL,
624             .help = "Verify SSL certificate"
625         },
626         {
627             .name = CURL_BLOCK_OPT_TIMEOUT,
628             .type = QEMU_OPT_NUMBER,
629             .help = "Curl timeout"
630         },
631         {
632             .name = CURL_BLOCK_OPT_COOKIE,
633             .type = QEMU_OPT_STRING,
634             .help = "Pass the cookie or list of cookies with each request"
635         },
636         {
637             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
638             .type = QEMU_OPT_STRING,
639             .help = "ID of secret used as cookie passed with each request"
640         },
641         {
642             .name = CURL_BLOCK_OPT_USERNAME,
643             .type = QEMU_OPT_STRING,
644             .help = "Username for HTTP auth"
645         },
646         {
647             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
648             .type = QEMU_OPT_STRING,
649             .help = "ID of secret used as password for HTTP auth",
650         },
651         {
652             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
653             .type = QEMU_OPT_STRING,
654             .help = "Username for HTTP proxy auth"
655         },
656         {
657             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
658             .type = QEMU_OPT_STRING,
659             .help = "ID of secret used as password for HTTP proxy auth",
660         },
661         { /* end of list */ }
662     },
663 };
664 
665 
666 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
667                      Error **errp)
668 {
669     BDRVCURLState *s = bs->opaque;
670     CURLState *state = NULL;
671     QemuOpts *opts;
672     Error *local_err = NULL;
673     const char *file;
674     const char *cookie;
675     const char *cookie_secret;
676     double d;
677     const char *secretid;
678     const char *protocol_delimiter;
679     int ret;
680 
681     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
682                                     errp);
683     if (ret < 0) {
684         return ret;
685     }
686 
687     if (!libcurl_initialized) {
688         ret = curl_global_init(CURL_GLOBAL_ALL);
689         if (ret) {
690             error_setg(errp, "libcurl initialization failed with %d", ret);
691             return -EIO;
692         }
693         libcurl_initialized = true;
694     }
695 
696     qemu_mutex_init(&s->mutex);
697     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
698     qemu_opts_absorb_qdict(opts, options, &local_err);
699     if (local_err) {
700         error_propagate(errp, local_err);
701         goto out_noclean;
702     }
703 
704     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
705                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
706     if ((s->readahead_size & 0x1ff) != 0) {
707         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
708                    s->readahead_size);
709         goto out_noclean;
710     }
711 
712     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
713                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
714     if (s->timeout > CURL_TIMEOUT_MAX) {
715         error_setg(errp, "timeout parameter is too large or negative");
716         goto out_noclean;
717     }
718 
719     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
720                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
721 
722     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
723     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
724 
725     if (cookie && cookie_secret) {
726         error_setg(errp,
727                    "curl driver cannot handle both cookie and cookie secret");
728         goto out_noclean;
729     }
730 
731     if (cookie_secret) {
732         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
733         if (!s->cookie) {
734             goto out_noclean;
735         }
736     } else {
737         s->cookie = g_strdup(cookie);
738     }
739 
740     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
741     if (file == NULL) {
742         error_setg(errp, "curl block driver requires an 'url' option");
743         goto out_noclean;
744     }
745 
746     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
747         !strstart(protocol_delimiter, "://", NULL))
748     {
749         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
750                    "start with '%s://')", bs->drv->protocol_name, file,
751                    bs->drv->protocol_name);
752         goto out_noclean;
753     }
754 
755     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
756     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
757 
758     if (secretid) {
759         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
760         if (!s->password) {
761             goto out_noclean;
762         }
763     }
764 
765     s->proxyusername = g_strdup(
766         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
767     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
768     if (secretid) {
769         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
770         if (!s->proxypassword) {
771             goto out_noclean;
772         }
773     }
774 
775     trace_curl_open(file);
776     qemu_co_queue_init(&s->free_state_waitq);
777     s->aio_context = bdrv_get_aio_context(bs);
778     s->url = g_strdup(file);
779     qemu_mutex_lock(&s->mutex);
780     state = curl_find_state(s);
781     qemu_mutex_unlock(&s->mutex);
782     if (!state) {
783         goto out_noclean;
784     }
785 
786     // Get file size
787 
788     if (curl_init_state(s, state) < 0) {
789         goto out;
790     }
791 
792     s->accept_range = false;
793     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
794     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
795                      curl_header_cb);
796     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
797     if (curl_easy_perform(state->curl))
798         goto out;
799     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
800         goto out;
801     }
802     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
803      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
804      * known and zero if it is really zero-length file. */
805 #if LIBCURL_VERSION_NUM >= 0x071304
806     if (d < 0) {
807         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
808                 "Server didn't report file size.");
809         goto out;
810     }
811 #else
812     if (d <= 0) {
813         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
814                 "Unknown file size or zero-length file.");
815         goto out;
816     }
817 #endif
818 
819     s->len = d;
820 
821     if ((!strncasecmp(s->url, "http://", strlen("http://"))
822         || !strncasecmp(s->url, "https://", strlen("https://")))
823         && !s->accept_range) {
824         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
825                 "Server does not support 'range' (byte ranges).");
826         goto out;
827     }
828     trace_curl_open_size(s->len);
829 
830     qemu_mutex_lock(&s->mutex);
831     curl_clean_state(state);
832     qemu_mutex_unlock(&s->mutex);
833     curl_easy_cleanup(state->curl);
834     state->curl = NULL;
835 
836     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
837 
838     qemu_opts_del(opts);
839     return 0;
840 
841 out:
842     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
843     curl_easy_cleanup(state->curl);
844     state->curl = NULL;
845 out_noclean:
846     qemu_mutex_destroy(&s->mutex);
847     g_free(s->cookie);
848     g_free(s->url);
849     g_free(s->username);
850     g_free(s->proxyusername);
851     g_free(s->proxypassword);
852     qemu_opts_del(opts);
853     return -EINVAL;
854 }
855 
856 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
857 {
858     CURLState *state;
859     int running;
860 
861     BDRVCURLState *s = bs->opaque;
862 
863     uint64_t start = acb->offset;
864     uint64_t end;
865 
866     qemu_mutex_lock(&s->mutex);
867 
868     // In case we have the requested data already (e.g. read-ahead),
869     // we can just call the callback and be done.
870     if (curl_find_buf(s, start, acb->bytes, acb)) {
871         goto out;
872     }
873 
874     // No cache found, so let's start a new request
875     for (;;) {
876         state = curl_find_state(s);
877         if (state) {
878             break;
879         }
880         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
881     }
882 
883     if (curl_init_state(s, state) < 0) {
884         curl_clean_state(state);
885         acb->ret = -EIO;
886         goto out;
887     }
888 
889     acb->start = 0;
890     acb->end = MIN(acb->bytes, s->len - start);
891 
892     state->buf_off = 0;
893     g_free(state->orig_buf);
894     state->buf_start = start;
895     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
896     end = start + state->buf_len - 1;
897     state->orig_buf = g_try_malloc(state->buf_len);
898     if (state->buf_len && state->orig_buf == NULL) {
899         curl_clean_state(state);
900         acb->ret = -ENOMEM;
901         goto out;
902     }
903     state->acb[0] = acb;
904 
905     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
906     trace_curl_setup_preadv(acb->bytes, start, state->range);
907     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
908 
909     if (curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
910         state->acb[0] = NULL;
911         acb->ret = -EIO;
912 
913         curl_clean_state(state);
914         goto out;
915     }
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     trace_curl_close();
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 void curl_refresh_filename(BlockDriverState *bs)
964 {
965     BDRVCURLState *s = bs->opaque;
966 
967     /* "readahead" and "timeout" do not change the guest-visible data,
968      * so ignore them */
969     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
970         s->cookie || s->username || s->password || s->proxyusername ||
971         s->proxypassword)
972     {
973         return;
974     }
975 
976     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
977 }
978 
979 
980 static const char *const curl_strong_runtime_opts[] = {
981     CURL_BLOCK_OPT_URL,
982     CURL_BLOCK_OPT_SSLVERIFY,
983     CURL_BLOCK_OPT_COOKIE,
984     CURL_BLOCK_OPT_COOKIE_SECRET,
985     CURL_BLOCK_OPT_USERNAME,
986     CURL_BLOCK_OPT_PASSWORD_SECRET,
987     CURL_BLOCK_OPT_PROXY_USERNAME,
988     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
989 
990     NULL
991 };
992 
993 static BlockDriver bdrv_http = {
994     .format_name                = "http",
995     .protocol_name              = "http",
996 
997     .instance_size              = sizeof(BDRVCURLState),
998     .bdrv_parse_filename        = curl_parse_filename,
999     .bdrv_file_open             = curl_open,
1000     .bdrv_close                 = curl_close,
1001     .bdrv_getlength             = curl_getlength,
1002 
1003     .bdrv_co_preadv             = curl_co_preadv,
1004 
1005     .bdrv_detach_aio_context    = curl_detach_aio_context,
1006     .bdrv_attach_aio_context    = curl_attach_aio_context,
1007 
1008     .bdrv_refresh_filename      = curl_refresh_filename,
1009     .strong_runtime_opts        = curl_strong_runtime_opts,
1010 };
1011 
1012 static BlockDriver bdrv_https = {
1013     .format_name                = "https",
1014     .protocol_name              = "https",
1015 
1016     .instance_size              = sizeof(BDRVCURLState),
1017     .bdrv_parse_filename        = curl_parse_filename,
1018     .bdrv_file_open             = curl_open,
1019     .bdrv_close                 = curl_close,
1020     .bdrv_getlength             = curl_getlength,
1021 
1022     .bdrv_co_preadv             = curl_co_preadv,
1023 
1024     .bdrv_detach_aio_context    = curl_detach_aio_context,
1025     .bdrv_attach_aio_context    = curl_attach_aio_context,
1026 
1027     .bdrv_refresh_filename      = curl_refresh_filename,
1028     .strong_runtime_opts        = curl_strong_runtime_opts,
1029 };
1030 
1031 static BlockDriver bdrv_ftp = {
1032     .format_name                = "ftp",
1033     .protocol_name              = "ftp",
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_getlength             = curl_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_ftps = {
1051     .format_name                = "ftps",
1052     .protocol_name              = "ftps",
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_getlength             = curl_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 void curl_block_init(void)
1070 {
1071     bdrv_register(&bdrv_http);
1072     bdrv_register(&bdrv_https);
1073     bdrv_register(&bdrv_ftp);
1074     bdrv_register(&bdrv_ftps);
1075 }
1076 
1077 block_init(curl_block_init);
1078