xref: /openbmc/qemu/block/curl.c (revision 6016b7b4)
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 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
41                    CURLPROTO_FTP | CURLPROTO_FTPS)
42 
43 #define CURL_NUM_STATES 8
44 #define CURL_NUM_ACB    8
45 #define CURL_TIMEOUT_MAX 10000
46 
47 #define CURL_BLOCK_OPT_URL       "url"
48 #define CURL_BLOCK_OPT_READAHEAD "readahead"
49 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
50 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
51 #define CURL_BLOCK_OPT_COOKIE    "cookie"
52 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
53 #define CURL_BLOCK_OPT_USERNAME "username"
54 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
55 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
56 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
57 
58 #define CURL_BLOCK_OPT_READAHEAD_DEFAULT (256 * 1024)
59 #define CURL_BLOCK_OPT_SSLVERIFY_DEFAULT true
60 #define CURL_BLOCK_OPT_TIMEOUT_DEFAULT 5
61 
62 struct BDRVCURLState;
63 struct CURLState;
64 
65 static bool libcurl_initialized;
66 
67 typedef struct CURLAIOCB {
68     Coroutine *co;
69     QEMUIOVector *qiov;
70 
71     uint64_t offset;
72     uint64_t bytes;
73     int ret;
74 
75     size_t start;
76     size_t end;
77 } CURLAIOCB;
78 
79 typedef struct CURLSocket {
80     int fd;
81     struct BDRVCURLState *s;
82 } CURLSocket;
83 
84 typedef struct CURLState
85 {
86     struct BDRVCURLState *s;
87     CURLAIOCB *acb[CURL_NUM_ACB];
88     CURL *curl;
89     char *orig_buf;
90     uint64_t buf_start;
91     size_t buf_off;
92     size_t buf_len;
93     char range[128];
94     char errmsg[CURL_ERROR_SIZE];
95     char in_use;
96 } CURLState;
97 
98 typedef struct BDRVCURLState {
99     CURLM *multi;
100     QEMUTimer timer;
101     uint64_t len;
102     CURLState states[CURL_NUM_STATES];
103     GHashTable *sockets; /* GINT_TO_POINTER(fd) -> socket */
104     char *url;
105     size_t readahead_size;
106     bool sslverify;
107     uint64_t timeout;
108     char *cookie;
109     bool accept_range;
110     AioContext *aio_context;
111     QemuMutex mutex;
112     CoQueue free_state_waitq;
113     char *username;
114     char *password;
115     char *proxyusername;
116     char *proxypassword;
117 } BDRVCURLState;
118 
119 static void curl_clean_state(CURLState *s);
120 static void curl_multi_do(void *arg);
121 
122 static gboolean curl_drop_socket(void *key, void *value, void *opaque)
123 {
124     CURLSocket *socket = value;
125     BDRVCURLState *s = socket->s;
126 
127     aio_set_fd_handler(s->aio_context, socket->fd, false,
128                        NULL, NULL, NULL, NULL);
129     return true;
130 }
131 
132 static void curl_drop_all_sockets(GHashTable *sockets)
133 {
134     g_hash_table_foreach_remove(sockets, curl_drop_socket, NULL);
135 }
136 
137 /* Called from curl_multi_do_locked, with s->mutex held.  */
138 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
139 {
140     BDRVCURLState *s = opaque;
141 
142     trace_curl_timer_cb(timeout_ms);
143     if (timeout_ms == -1) {
144         timer_del(&s->timer);
145     } else {
146         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
147         timer_mod(&s->timer,
148                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
149     }
150     return 0;
151 }
152 
153 /* Called from curl_multi_do_locked, with s->mutex held.  */
154 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
155                         void *userp, void *sp)
156 {
157     BDRVCURLState *s;
158     CURLState *state = NULL;
159     CURLSocket *socket;
160 
161     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
162     s = state->s;
163 
164     socket = g_hash_table_lookup(s->sockets, GINT_TO_POINTER(fd));
165     if (!socket) {
166         socket = g_new0(CURLSocket, 1);
167         socket->fd = fd;
168         socket->s = s;
169         g_hash_table_insert(s->sockets, GINT_TO_POINTER(fd), socket);
170     }
171 
172     trace_curl_sock_cb(action, (int)fd);
173     switch (action) {
174         case CURL_POLL_IN:
175             aio_set_fd_handler(s->aio_context, fd, false,
176                                curl_multi_do, NULL, NULL, socket);
177             break;
178         case CURL_POLL_OUT:
179             aio_set_fd_handler(s->aio_context, fd, false,
180                                NULL, curl_multi_do, NULL, socket);
181             break;
182         case CURL_POLL_INOUT:
183             aio_set_fd_handler(s->aio_context, fd, false,
184                                curl_multi_do, curl_multi_do, NULL, socket);
185             break;
186         case CURL_POLL_REMOVE:
187             aio_set_fd_handler(s->aio_context, fd, false,
188                                NULL, NULL, NULL, NULL);
189             break;
190     }
191 
192     if (action == CURL_POLL_REMOVE) {
193         g_hash_table_remove(s->sockets, GINT_TO_POINTER(fd));
194     }
195 
196     return 0;
197 }
198 
199 /* Called from curl_multi_do_locked, with s->mutex held.  */
200 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
201 {
202     BDRVCURLState *s = opaque;
203     size_t realsize = size * nmemb;
204     const char *header = (char *)ptr;
205     const char *end = header + realsize;
206     const char *accept_ranges = "accept-ranges:";
207     const char *bytes = "bytes";
208 
209     if (realsize >= strlen(accept_ranges)
210         && g_ascii_strncasecmp(header, accept_ranges,
211                                strlen(accept_ranges)) == 0) {
212 
213         char *p = strchr(header, ':') + 1;
214 
215         /* Skip whitespace between the header name and value. */
216         while (p < end && *p && g_ascii_isspace(*p)) {
217             p++;
218         }
219 
220         if (end - p >= strlen(bytes)
221             && strncmp(p, bytes, strlen(bytes)) == 0) {
222 
223             /* Check that there is nothing but whitespace after the value. */
224             p += strlen(bytes);
225             while (p < end && *p && g_ascii_isspace(*p)) {
226                 p++;
227             }
228 
229             if (p == end || !*p) {
230                 s->accept_range = true;
231             }
232         }
233     }
234 
235     return realsize;
236 }
237 
238 /* Called from curl_multi_do_locked, with s->mutex held.  */
239 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
240 {
241     CURLState *s = ((CURLState*)opaque);
242     size_t realsize = size * nmemb;
243 
244     trace_curl_read_cb(realsize);
245 
246     if (!s || !s->orig_buf) {
247         goto read_end;
248     }
249 
250     if (s->buf_off >= s->buf_len) {
251         /* buffer full, read nothing */
252         goto read_end;
253     }
254     realsize = MIN(realsize, s->buf_len - s->buf_off);
255     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
256     s->buf_off += realsize;
257 
258 read_end:
259     /* curl will error out if we do not return this value */
260     return size * nmemb;
261 }
262 
263 /* Called with s->mutex held.  */
264 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
265                           CURLAIOCB *acb)
266 {
267     int i;
268     uint64_t end = start + len;
269     uint64_t clamped_end = MIN(end, s->len);
270     uint64_t clamped_len = clamped_end - start;
271 
272     for (i=0; i<CURL_NUM_STATES; i++) {
273         CURLState *state = &s->states[i];
274         uint64_t buf_end = (state->buf_start + state->buf_off);
275         uint64_t buf_fend = (state->buf_start + state->buf_len);
276 
277         if (!state->orig_buf)
278             continue;
279         if (!state->buf_off)
280             continue;
281 
282         // Does the existing buffer cover our section?
283         if ((start >= state->buf_start) &&
284             (start <= buf_end) &&
285             (clamped_end >= state->buf_start) &&
286             (clamped_end <= buf_end))
287         {
288             char *buf = state->orig_buf + (start - state->buf_start);
289 
290             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
291             if (clamped_len < len) {
292                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
293             }
294             acb->ret = 0;
295             return true;
296         }
297 
298         // Wait for unfinished chunks
299         if (state->in_use &&
300             (start >= state->buf_start) &&
301             (start <= buf_fend) &&
302             (clamped_end >= state->buf_start) &&
303             (clamped_end <= buf_fend))
304         {
305             int j;
306 
307             acb->start = start - state->buf_start;
308             acb->end = acb->start + clamped_len;
309 
310             for (j=0; j<CURL_NUM_ACB; j++) {
311                 if (!state->acb[j]) {
312                     state->acb[j] = acb;
313                     return true;
314                 }
315             }
316         }
317     }
318 
319     return false;
320 }
321 
322 /* Called with s->mutex held.  */
323 static void curl_multi_check_completion(BDRVCURLState *s)
324 {
325     int msgs_in_queue;
326 
327     /* Try to find done transfers, so we can free the easy
328      * handle again. */
329     for (;;) {
330         CURLMsg *msg;
331         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
332 
333         /* Quit when there are no more completions */
334         if (!msg)
335             break;
336 
337         if (msg->msg == CURLMSG_DONE) {
338             int i;
339             CURLState *state = NULL;
340             bool error = msg->data.result != CURLE_OK;
341 
342             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
343                               (char **)&state);
344 
345             if (error) {
346                 static int errcount = 100;
347 
348                 /* Don't lose the original error message from curl, since
349                  * it contains extra data.
350                  */
351                 if (errcount > 0) {
352                     error_report("curl: %s", state->errmsg);
353                     if (--errcount == 0) {
354                         error_report("curl: further errors suppressed");
355                     }
356                 }
357             }
358 
359             for (i = 0; i < CURL_NUM_ACB; i++) {
360                 CURLAIOCB *acb = state->acb[i];
361 
362                 if (acb == NULL) {
363                     continue;
364                 }
365 
366                 if (!error) {
367                     /* Assert that we have read all data */
368                     assert(state->buf_off >= acb->end);
369 
370                     qemu_iovec_from_buf(acb->qiov, 0,
371                                         state->orig_buf + acb->start,
372                                         acb->end - acb->start);
373 
374                     if (acb->end - acb->start < acb->bytes) {
375                         size_t offset = acb->end - acb->start;
376                         qemu_iovec_memset(acb->qiov, offset, 0,
377                                           acb->bytes - offset);
378                     }
379                 }
380 
381                 acb->ret = error ? -EIO : 0;
382                 state->acb[i] = NULL;
383                 qemu_mutex_unlock(&s->mutex);
384                 aio_co_wake(acb->co);
385                 qemu_mutex_lock(&s->mutex);
386             }
387 
388             curl_clean_state(state);
389             break;
390         }
391     }
392 }
393 
394 /* Called with s->mutex held.  */
395 static void curl_multi_do_locked(CURLSocket *socket)
396 {
397     BDRVCURLState *s = socket->s;
398     int running;
399     int r;
400 
401     if (!s->multi) {
402         return;
403     }
404 
405     do {
406         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
407     } while (r == CURLM_CALL_MULTI_PERFORM);
408 }
409 
410 static void curl_multi_do(void *arg)
411 {
412     CURLSocket *socket = arg;
413     BDRVCURLState *s = socket->s;
414 
415     qemu_mutex_lock(&s->mutex);
416     curl_multi_do_locked(socket);
417     curl_multi_check_completion(s);
418     qemu_mutex_unlock(&s->mutex);
419 }
420 
421 static void curl_multi_timeout_do(void *arg)
422 {
423     BDRVCURLState *s = (BDRVCURLState *)arg;
424     int running;
425 
426     if (!s->multi) {
427         return;
428     }
429 
430     qemu_mutex_lock(&s->mutex);
431     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
432 
433     curl_multi_check_completion(s);
434     qemu_mutex_unlock(&s->mutex);
435 }
436 
437 /* Called with s->mutex held.  */
438 static CURLState *curl_find_state(BDRVCURLState *s)
439 {
440     CURLState *state = NULL;
441     int i;
442 
443     for (i = 0; i < CURL_NUM_STATES; i++) {
444         if (!s->states[i].in_use) {
445             state = &s->states[i];
446             state->in_use = 1;
447             break;
448         }
449     }
450     return state;
451 }
452 
453 static int curl_init_state(BDRVCURLState *s, CURLState *state)
454 {
455     if (!state->curl) {
456         state->curl = curl_easy_init();
457         if (!state->curl) {
458             return -EIO;
459         }
460         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
461         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
462                          (long) s->sslverify);
463         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
464                          s->sslverify ? 2L : 0L);
465         if (s->cookie) {
466             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
467         }
468         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
469         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
470                          (void *)curl_read_cb);
471         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
472         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
473         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
474         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
475         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
476         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
477         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
478 
479         if (s->username) {
480             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
481         }
482         if (s->password) {
483             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
484         }
485         if (s->proxyusername) {
486             curl_easy_setopt(state->curl,
487                              CURLOPT_PROXYUSERNAME, s->proxyusername);
488         }
489         if (s->proxypassword) {
490             curl_easy_setopt(state->curl,
491                              CURLOPT_PROXYPASSWORD, s->proxypassword);
492         }
493 
494         /* Restrict supported protocols to avoid security issues in the more
495          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
496          * CVE-2013-0249.
497          *
498          * Restricting protocols is only supported from 7.19.4 upwards.
499          */
500 #if LIBCURL_VERSION_NUM >= 0x071304
501         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
502         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
503 #endif
504 
505 #ifdef DEBUG_VERBOSE
506         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
507 #endif
508     }
509 
510     state->s = s;
511 
512     return 0;
513 }
514 
515 /* Called with s->mutex held.  */
516 static void curl_clean_state(CURLState *s)
517 {
518     int j;
519     for (j = 0; j < CURL_NUM_ACB; j++) {
520         assert(!s->acb[j]);
521     }
522 
523     if (s->s->multi)
524         curl_multi_remove_handle(s->s->multi, s->curl);
525 
526     s->in_use = 0;
527 
528     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
529 }
530 
531 static void curl_parse_filename(const char *filename, QDict *options,
532                                 Error **errp)
533 {
534     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
535 }
536 
537 static void curl_detach_aio_context(BlockDriverState *bs)
538 {
539     BDRVCURLState *s = bs->opaque;
540     int i;
541 
542     WITH_QEMU_LOCK_GUARD(&s->mutex) {
543         curl_drop_all_sockets(s->sockets);
544         for (i = 0; i < CURL_NUM_STATES; i++) {
545             if (s->states[i].in_use) {
546                 curl_clean_state(&s->states[i]);
547             }
548             if (s->states[i].curl) {
549                 curl_easy_cleanup(s->states[i].curl);
550                 s->states[i].curl = NULL;
551             }
552             g_free(s->states[i].orig_buf);
553             s->states[i].orig_buf = NULL;
554         }
555         if (s->multi) {
556             curl_multi_cleanup(s->multi);
557             s->multi = NULL;
558         }
559     }
560 
561     timer_del(&s->timer);
562 }
563 
564 static void curl_attach_aio_context(BlockDriverState *bs,
565                                     AioContext *new_context)
566 {
567     BDRVCURLState *s = bs->opaque;
568 
569     aio_timer_init(new_context, &s->timer,
570                    QEMU_CLOCK_REALTIME, SCALE_NS,
571                    curl_multi_timeout_do, s);
572 
573     assert(!s->multi);
574     s->multi = curl_multi_init();
575     s->aio_context = new_context;
576     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
577     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
578     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
579 }
580 
581 static QemuOptsList runtime_opts = {
582     .name = "curl",
583     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
584     .desc = {
585         {
586             .name = CURL_BLOCK_OPT_URL,
587             .type = QEMU_OPT_STRING,
588             .help = "URL to open",
589         },
590         {
591             .name = CURL_BLOCK_OPT_READAHEAD,
592             .type = QEMU_OPT_SIZE,
593             .help = "Readahead size",
594         },
595         {
596             .name = CURL_BLOCK_OPT_SSLVERIFY,
597             .type = QEMU_OPT_BOOL,
598             .help = "Verify SSL certificate"
599         },
600         {
601             .name = CURL_BLOCK_OPT_TIMEOUT,
602             .type = QEMU_OPT_NUMBER,
603             .help = "Curl timeout"
604         },
605         {
606             .name = CURL_BLOCK_OPT_COOKIE,
607             .type = QEMU_OPT_STRING,
608             .help = "Pass the cookie or list of cookies with each request"
609         },
610         {
611             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
612             .type = QEMU_OPT_STRING,
613             .help = "ID of secret used as cookie passed with each request"
614         },
615         {
616             .name = CURL_BLOCK_OPT_USERNAME,
617             .type = QEMU_OPT_STRING,
618             .help = "Username for HTTP auth"
619         },
620         {
621             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
622             .type = QEMU_OPT_STRING,
623             .help = "ID of secret used as password for HTTP auth",
624         },
625         {
626             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
627             .type = QEMU_OPT_STRING,
628             .help = "Username for HTTP proxy auth"
629         },
630         {
631             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
632             .type = QEMU_OPT_STRING,
633             .help = "ID of secret used as password for HTTP proxy auth",
634         },
635         { /* end of list */ }
636     },
637 };
638 
639 
640 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
641                      Error **errp)
642 {
643     BDRVCURLState *s = bs->opaque;
644     CURLState *state = NULL;
645     QemuOpts *opts;
646     const char *file;
647     const char *cookie;
648     const char *cookie_secret;
649     double d;
650     const char *secretid;
651     const char *protocol_delimiter;
652     int ret;
653 
654     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
655                                     errp);
656     if (ret < 0) {
657         return ret;
658     }
659 
660     if (!libcurl_initialized) {
661         ret = curl_global_init(CURL_GLOBAL_ALL);
662         if (ret) {
663             error_setg(errp, "libcurl initialization failed with %d", ret);
664             return -EIO;
665         }
666         libcurl_initialized = true;
667     }
668 
669     qemu_mutex_init(&s->mutex);
670     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
671     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
672         goto out_noclean;
673     }
674 
675     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
676                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
677     if ((s->readahead_size & 0x1ff) != 0) {
678         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
679                    s->readahead_size);
680         goto out_noclean;
681     }
682 
683     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
684                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
685     if (s->timeout > CURL_TIMEOUT_MAX) {
686         error_setg(errp, "timeout parameter is too large or negative");
687         goto out_noclean;
688     }
689 
690     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
691                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
692 
693     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
694     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
695 
696     if (cookie && cookie_secret) {
697         error_setg(errp,
698                    "curl driver cannot handle both cookie and cookie secret");
699         goto out_noclean;
700     }
701 
702     if (cookie_secret) {
703         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
704         if (!s->cookie) {
705             goto out_noclean;
706         }
707     } else {
708         s->cookie = g_strdup(cookie);
709     }
710 
711     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
712     if (file == NULL) {
713         error_setg(errp, "curl block driver requires an 'url' option");
714         goto out_noclean;
715     }
716 
717     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
718         !strstart(protocol_delimiter, "://", NULL))
719     {
720         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
721                    "start with '%s://')", bs->drv->protocol_name, file,
722                    bs->drv->protocol_name);
723         goto out_noclean;
724     }
725 
726     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
727     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
728 
729     if (secretid) {
730         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
731         if (!s->password) {
732             goto out_noclean;
733         }
734     }
735 
736     s->proxyusername = g_strdup(
737         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
738     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
739     if (secretid) {
740         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
741         if (!s->proxypassword) {
742             goto out_noclean;
743         }
744     }
745 
746     trace_curl_open(file);
747     qemu_co_queue_init(&s->free_state_waitq);
748     s->aio_context = bdrv_get_aio_context(bs);
749     s->url = g_strdup(file);
750     s->sockets = g_hash_table_new_full(NULL, NULL, NULL, g_free);
751     qemu_mutex_lock(&s->mutex);
752     state = curl_find_state(s);
753     qemu_mutex_unlock(&s->mutex);
754     if (!state) {
755         goto out_noclean;
756     }
757 
758     // Get file size
759 
760     if (curl_init_state(s, state) < 0) {
761         goto out;
762     }
763 
764     s->accept_range = false;
765     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
766     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
767                      curl_header_cb);
768     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
769     if (curl_easy_perform(state->curl))
770         goto out;
771     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
772         goto out;
773     }
774     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
775      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
776      * known and zero if it is really zero-length file. */
777 #if LIBCURL_VERSION_NUM >= 0x071304
778     if (d < 0) {
779         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
780                 "Server didn't report file size.");
781         goto out;
782     }
783 #else
784     if (d <= 0) {
785         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
786                 "Unknown file size or zero-length file.");
787         goto out;
788     }
789 #endif
790 
791     s->len = d;
792 
793     if ((!strncasecmp(s->url, "http://", strlen("http://"))
794         || !strncasecmp(s->url, "https://", strlen("https://")))
795         && !s->accept_range) {
796         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
797                 "Server does not support 'range' (byte ranges).");
798         goto out;
799     }
800     trace_curl_open_size(s->len);
801 
802     qemu_mutex_lock(&s->mutex);
803     curl_clean_state(state);
804     qemu_mutex_unlock(&s->mutex);
805     curl_easy_cleanup(state->curl);
806     state->curl = NULL;
807 
808     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
809 
810     qemu_opts_del(opts);
811     return 0;
812 
813 out:
814     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
815     curl_easy_cleanup(state->curl);
816     state->curl = NULL;
817 out_noclean:
818     qemu_mutex_destroy(&s->mutex);
819     g_free(s->cookie);
820     g_free(s->url);
821     g_free(s->username);
822     g_free(s->proxyusername);
823     g_free(s->proxypassword);
824     curl_drop_all_sockets(s->sockets);
825     g_hash_table_destroy(s->sockets);
826     qemu_opts_del(opts);
827     return -EINVAL;
828 }
829 
830 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
831 {
832     CURLState *state;
833     int running;
834 
835     BDRVCURLState *s = bs->opaque;
836 
837     uint64_t start = acb->offset;
838     uint64_t end;
839 
840     qemu_mutex_lock(&s->mutex);
841 
842     // In case we have the requested data already (e.g. read-ahead),
843     // we can just call the callback and be done.
844     if (curl_find_buf(s, start, acb->bytes, acb)) {
845         goto out;
846     }
847 
848     // No cache found, so let's start a new request
849     for (;;) {
850         state = curl_find_state(s);
851         if (state) {
852             break;
853         }
854         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
855     }
856 
857     if (curl_init_state(s, state) < 0) {
858         curl_clean_state(state);
859         acb->ret = -EIO;
860         goto out;
861     }
862 
863     acb->start = 0;
864     acb->end = MIN(acb->bytes, s->len - start);
865 
866     state->buf_off = 0;
867     g_free(state->orig_buf);
868     state->buf_start = start;
869     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
870     end = start + state->buf_len - 1;
871     state->orig_buf = g_try_malloc(state->buf_len);
872     if (state->buf_len && state->orig_buf == NULL) {
873         curl_clean_state(state);
874         acb->ret = -ENOMEM;
875         goto out;
876     }
877     state->acb[0] = acb;
878 
879     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
880     trace_curl_setup_preadv(acb->bytes, start, state->range);
881     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
882 
883     if (curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
884         state->acb[0] = NULL;
885         acb->ret = -EIO;
886 
887         curl_clean_state(state);
888         goto out;
889     }
890 
891     /* Tell curl it needs to kick things off */
892     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
893 
894 out:
895     qemu_mutex_unlock(&s->mutex);
896 }
897 
898 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
899         int64_t offset, int64_t bytes, QEMUIOVector *qiov,
900         BdrvRequestFlags flags)
901 {
902     CURLAIOCB acb = {
903         .co = qemu_coroutine_self(),
904         .ret = -EINPROGRESS,
905         .qiov = qiov,
906         .offset = offset,
907         .bytes = bytes
908     };
909 
910     curl_setup_preadv(bs, &acb);
911     while (acb.ret == -EINPROGRESS) {
912         qemu_coroutine_yield();
913     }
914     return acb.ret;
915 }
916 
917 static void curl_close(BlockDriverState *bs)
918 {
919     BDRVCURLState *s = bs->opaque;
920 
921     trace_curl_close();
922     curl_detach_aio_context(bs);
923     qemu_mutex_destroy(&s->mutex);
924 
925     g_hash_table_destroy(s->sockets);
926     g_free(s->cookie);
927     g_free(s->url);
928     g_free(s->username);
929     g_free(s->proxyusername);
930     g_free(s->proxypassword);
931 }
932 
933 static int64_t curl_getlength(BlockDriverState *bs)
934 {
935     BDRVCURLState *s = bs->opaque;
936     return s->len;
937 }
938 
939 static void curl_refresh_filename(BlockDriverState *bs)
940 {
941     BDRVCURLState *s = bs->opaque;
942 
943     /* "readahead" and "timeout" do not change the guest-visible data,
944      * so ignore them */
945     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
946         s->cookie || s->username || s->password || s->proxyusername ||
947         s->proxypassword)
948     {
949         return;
950     }
951 
952     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
953 }
954 
955 
956 static const char *const curl_strong_runtime_opts[] = {
957     CURL_BLOCK_OPT_URL,
958     CURL_BLOCK_OPT_SSLVERIFY,
959     CURL_BLOCK_OPT_COOKIE,
960     CURL_BLOCK_OPT_COOKIE_SECRET,
961     CURL_BLOCK_OPT_USERNAME,
962     CURL_BLOCK_OPT_PASSWORD_SECRET,
963     CURL_BLOCK_OPT_PROXY_USERNAME,
964     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
965 
966     NULL
967 };
968 
969 static BlockDriver bdrv_http = {
970     .format_name                = "http",
971     .protocol_name              = "http",
972 
973     .instance_size              = sizeof(BDRVCURLState),
974     .bdrv_parse_filename        = curl_parse_filename,
975     .bdrv_file_open             = curl_open,
976     .bdrv_close                 = curl_close,
977     .bdrv_getlength             = curl_getlength,
978 
979     .bdrv_co_preadv             = curl_co_preadv,
980 
981     .bdrv_detach_aio_context    = curl_detach_aio_context,
982     .bdrv_attach_aio_context    = curl_attach_aio_context,
983 
984     .bdrv_refresh_filename      = curl_refresh_filename,
985     .strong_runtime_opts        = curl_strong_runtime_opts,
986 };
987 
988 static BlockDriver bdrv_https = {
989     .format_name                = "https",
990     .protocol_name              = "https",
991 
992     .instance_size              = sizeof(BDRVCURLState),
993     .bdrv_parse_filename        = curl_parse_filename,
994     .bdrv_file_open             = curl_open,
995     .bdrv_close                 = curl_close,
996     .bdrv_getlength             = curl_getlength,
997 
998     .bdrv_co_preadv             = curl_co_preadv,
999 
1000     .bdrv_detach_aio_context    = curl_detach_aio_context,
1001     .bdrv_attach_aio_context    = curl_attach_aio_context,
1002 
1003     .bdrv_refresh_filename      = curl_refresh_filename,
1004     .strong_runtime_opts        = curl_strong_runtime_opts,
1005 };
1006 
1007 static BlockDriver bdrv_ftp = {
1008     .format_name                = "ftp",
1009     .protocol_name              = "ftp",
1010 
1011     .instance_size              = sizeof(BDRVCURLState),
1012     .bdrv_parse_filename        = curl_parse_filename,
1013     .bdrv_file_open             = curl_open,
1014     .bdrv_close                 = curl_close,
1015     .bdrv_getlength             = curl_getlength,
1016 
1017     .bdrv_co_preadv             = curl_co_preadv,
1018 
1019     .bdrv_detach_aio_context    = curl_detach_aio_context,
1020     .bdrv_attach_aio_context    = curl_attach_aio_context,
1021 
1022     .bdrv_refresh_filename      = curl_refresh_filename,
1023     .strong_runtime_opts        = curl_strong_runtime_opts,
1024 };
1025 
1026 static BlockDriver bdrv_ftps = {
1027     .format_name                = "ftps",
1028     .protocol_name              = "ftps",
1029 
1030     .instance_size              = sizeof(BDRVCURLState),
1031     .bdrv_parse_filename        = curl_parse_filename,
1032     .bdrv_file_open             = curl_open,
1033     .bdrv_close                 = curl_close,
1034     .bdrv_getlength             = curl_getlength,
1035 
1036     .bdrv_co_preadv             = curl_co_preadv,
1037 
1038     .bdrv_detach_aio_context    = curl_detach_aio_context,
1039     .bdrv_attach_aio_context    = curl_attach_aio_context,
1040 
1041     .bdrv_refresh_filename      = curl_refresh_filename,
1042     .strong_runtime_opts        = curl_strong_runtime_opts,
1043 };
1044 
1045 static void curl_block_init(void)
1046 {
1047     bdrv_register(&bdrv_http);
1048     bdrv_register(&bdrv_https);
1049     bdrv_register(&bdrv_ftp);
1050     bdrv_register(&bdrv_ftps);
1051 }
1052 
1053 block_init(curl_block_init);
1054