xref: /openbmc/qemu/block/curl.c (revision 1da79ecc)
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 CURLState *state;
82     QLIST_ENTRY(CURLSocket) next;
83 } CURLSocket;
84 
85 typedef struct CURLState
86 {
87     struct BDRVCURLState *s;
88     CURLAIOCB *acb[CURL_NUM_ACB];
89     CURL *curl;
90     QLIST_HEAD(, CURLSocket) sockets;
91     char *orig_buf;
92     uint64_t buf_start;
93     size_t buf_off;
94     size_t buf_len;
95     char range[128];
96     char errmsg[CURL_ERROR_SIZE];
97     char in_use;
98 } CURLState;
99 
100 typedef struct BDRVCURLState {
101     CURLM *multi;
102     QEMUTimer timer;
103     uint64_t len;
104     CURLState states[CURL_NUM_STATES];
105     char *url;
106     size_t readahead_size;
107     bool sslverify;
108     uint64_t timeout;
109     char *cookie;
110     bool accept_range;
111     AioContext *aio_context;
112     QemuMutex mutex;
113     CoQueue free_state_waitq;
114     char *username;
115     char *password;
116     char *proxyusername;
117     char *proxypassword;
118 } BDRVCURLState;
119 
120 static void curl_clean_state(CURLState *s);
121 static void curl_multi_do(void *arg);
122 
123 /* Called from curl_multi_do_locked, with s->mutex held.  */
124 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
125 {
126     BDRVCURLState *s = opaque;
127 
128     trace_curl_timer_cb(timeout_ms);
129     if (timeout_ms == -1) {
130         timer_del(&s->timer);
131     } else {
132         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
133         timer_mod(&s->timer,
134                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
135     }
136     return 0;
137 }
138 
139 /* Called from curl_multi_do_locked, with s->mutex held.  */
140 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
141                         void *userp, void *sp)
142 {
143     BDRVCURLState *s;
144     CURLState *state = NULL;
145     CURLSocket *socket;
146 
147     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
148     s = state->s;
149 
150     QLIST_FOREACH(socket, &state->sockets, next) {
151         if (socket->fd == fd) {
152             break;
153         }
154     }
155     if (!socket) {
156         socket = g_new0(CURLSocket, 1);
157         socket->fd = fd;
158         socket->state = state;
159         QLIST_INSERT_HEAD(&state->sockets, socket, next);
160     }
161 
162     trace_curl_sock_cb(action, (int)fd);
163     switch (action) {
164         case CURL_POLL_IN:
165             aio_set_fd_handler(s->aio_context, fd, false,
166                                curl_multi_do, NULL, NULL, socket);
167             break;
168         case CURL_POLL_OUT:
169             aio_set_fd_handler(s->aio_context, fd, false,
170                                NULL, curl_multi_do, NULL, socket);
171             break;
172         case CURL_POLL_INOUT:
173             aio_set_fd_handler(s->aio_context, fd, false,
174                                curl_multi_do, curl_multi_do, NULL, socket);
175             break;
176         case CURL_POLL_REMOVE:
177             aio_set_fd_handler(s->aio_context, fd, false,
178                                NULL, NULL, NULL, NULL);
179             break;
180     }
181 
182     if (action == CURL_POLL_REMOVE) {
183         QLIST_REMOVE(socket, next);
184         g_free(socket);
185     }
186 
187     return 0;
188 }
189 
190 /* Called from curl_multi_do_locked, with s->mutex held.  */
191 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
192 {
193     BDRVCURLState *s = opaque;
194     size_t realsize = size * nmemb;
195     const char *header = (char *)ptr;
196     const char *end = header + realsize;
197     const char *accept_ranges = "accept-ranges:";
198     const char *bytes = "bytes";
199 
200     if (realsize >= strlen(accept_ranges)
201         && g_ascii_strncasecmp(header, accept_ranges,
202                                strlen(accept_ranges)) == 0) {
203 
204         char *p = strchr(header, ':') + 1;
205 
206         /* Skip whitespace between the header name and value. */
207         while (p < end && *p && g_ascii_isspace(*p)) {
208             p++;
209         }
210 
211         if (end - p >= strlen(bytes)
212             && strncmp(p, bytes, strlen(bytes)) == 0) {
213 
214             /* Check that there is nothing but whitespace after the value. */
215             p += strlen(bytes);
216             while (p < end && *p && g_ascii_isspace(*p)) {
217                 p++;
218             }
219 
220             if (p == end || !*p) {
221                 s->accept_range = true;
222             }
223         }
224     }
225 
226     return realsize;
227 }
228 
229 /* Called from curl_multi_do_locked, with s->mutex held.  */
230 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
231 {
232     CURLState *s = ((CURLState*)opaque);
233     size_t realsize = size * nmemb;
234 
235     trace_curl_read_cb(realsize);
236 
237     if (!s || !s->orig_buf) {
238         goto read_end;
239     }
240 
241     if (s->buf_off >= s->buf_len) {
242         /* buffer full, read nothing */
243         goto read_end;
244     }
245     realsize = MIN(realsize, s->buf_len - s->buf_off);
246     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
247     s->buf_off += realsize;
248 
249 read_end:
250     /* curl will error out if we do not return this value */
251     return size * nmemb;
252 }
253 
254 /* Called with s->mutex held.  */
255 static bool curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len,
256                           CURLAIOCB *acb)
257 {
258     int i;
259     uint64_t end = start + len;
260     uint64_t clamped_end = MIN(end, s->len);
261     uint64_t clamped_len = clamped_end - start;
262 
263     for (i=0; i<CURL_NUM_STATES; i++) {
264         CURLState *state = &s->states[i];
265         uint64_t buf_end = (state->buf_start + state->buf_off);
266         uint64_t buf_fend = (state->buf_start + state->buf_len);
267 
268         if (!state->orig_buf)
269             continue;
270         if (!state->buf_off)
271             continue;
272 
273         // Does the existing buffer cover our section?
274         if ((start >= state->buf_start) &&
275             (start <= buf_end) &&
276             (clamped_end >= state->buf_start) &&
277             (clamped_end <= buf_end))
278         {
279             char *buf = state->orig_buf + (start - state->buf_start);
280 
281             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
282             if (clamped_len < len) {
283                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
284             }
285             acb->ret = 0;
286             return true;
287         }
288 
289         // Wait for unfinished chunks
290         if (state->in_use &&
291             (start >= state->buf_start) &&
292             (start <= buf_fend) &&
293             (clamped_end >= state->buf_start) &&
294             (clamped_end <= buf_fend))
295         {
296             int j;
297 
298             acb->start = start - state->buf_start;
299             acb->end = acb->start + clamped_len;
300 
301             for (j=0; j<CURL_NUM_ACB; j++) {
302                 if (!state->acb[j]) {
303                     state->acb[j] = acb;
304                     return true;
305                 }
306             }
307         }
308     }
309 
310     return false;
311 }
312 
313 /* Called with s->mutex held.  */
314 static void curl_multi_check_completion(BDRVCURLState *s)
315 {
316     int msgs_in_queue;
317 
318     /* Try to find done transfers, so we can free the easy
319      * handle again. */
320     for (;;) {
321         CURLMsg *msg;
322         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
323 
324         /* Quit when there are no more completions */
325         if (!msg)
326             break;
327 
328         if (msg->msg == CURLMSG_DONE) {
329             int i;
330             CURLState *state = NULL;
331             bool error = msg->data.result != CURLE_OK;
332 
333             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
334                               (char **)&state);
335 
336             if (error) {
337                 static int errcount = 100;
338 
339                 /* Don't lose the original error message from curl, since
340                  * it contains extra data.
341                  */
342                 if (errcount > 0) {
343                     error_report("curl: %s", state->errmsg);
344                     if (--errcount == 0) {
345                         error_report("curl: further errors suppressed");
346                     }
347                 }
348             }
349 
350             for (i = 0; i < CURL_NUM_ACB; i++) {
351                 CURLAIOCB *acb = state->acb[i];
352 
353                 if (acb == NULL) {
354                     continue;
355                 }
356 
357                 if (!error) {
358                     /* Assert that we have read all data */
359                     assert(state->buf_off >= acb->end);
360 
361                     qemu_iovec_from_buf(acb->qiov, 0,
362                                         state->orig_buf + acb->start,
363                                         acb->end - acb->start);
364 
365                     if (acb->end - acb->start < acb->bytes) {
366                         size_t offset = acb->end - acb->start;
367                         qemu_iovec_memset(acb->qiov, offset, 0,
368                                           acb->bytes - offset);
369                     }
370                 }
371 
372                 acb->ret = error ? -EIO : 0;
373                 state->acb[i] = NULL;
374                 qemu_mutex_unlock(&s->mutex);
375                 aio_co_wake(acb->co);
376                 qemu_mutex_lock(&s->mutex);
377             }
378 
379             curl_clean_state(state);
380             break;
381         }
382     }
383 }
384 
385 /* Called with s->mutex held.  */
386 static void curl_multi_do_locked(CURLSocket *socket)
387 {
388     BDRVCURLState *s = socket->state->s;
389     int running;
390     int r;
391 
392     if (!s->multi) {
393         return;
394     }
395 
396     do {
397         r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
398     } while (r == CURLM_CALL_MULTI_PERFORM);
399 }
400 
401 static void curl_multi_do(void *arg)
402 {
403     CURLSocket *socket = arg;
404     BDRVCURLState *s = socket->state->s;
405 
406     qemu_mutex_lock(&s->mutex);
407     curl_multi_do_locked(socket);
408     curl_multi_check_completion(s);
409     qemu_mutex_unlock(&s->mutex);
410 }
411 
412 static void curl_multi_timeout_do(void *arg)
413 {
414     BDRVCURLState *s = (BDRVCURLState *)arg;
415     int running;
416 
417     if (!s->multi) {
418         return;
419     }
420 
421     qemu_mutex_lock(&s->mutex);
422     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
423 
424     curl_multi_check_completion(s);
425     qemu_mutex_unlock(&s->mutex);
426 }
427 
428 /* Called with s->mutex held.  */
429 static CURLState *curl_find_state(BDRVCURLState *s)
430 {
431     CURLState *state = NULL;
432     int i;
433 
434     for (i = 0; i < CURL_NUM_STATES; i++) {
435         if (!s->states[i].in_use) {
436             state = &s->states[i];
437             state->in_use = 1;
438             break;
439         }
440     }
441     return state;
442 }
443 
444 static int curl_init_state(BDRVCURLState *s, CURLState *state)
445 {
446     if (!state->curl) {
447         state->curl = curl_easy_init();
448         if (!state->curl) {
449             return -EIO;
450         }
451         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
452         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
453                          (long) s->sslverify);
454         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
455                          s->sslverify ? 2L : 0L);
456         if (s->cookie) {
457             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
458         }
459         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
460         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
461                          (void *)curl_read_cb);
462         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
463         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
464         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
465         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
466         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
467         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
468         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
469 
470         if (s->username) {
471             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
472         }
473         if (s->password) {
474             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
475         }
476         if (s->proxyusername) {
477             curl_easy_setopt(state->curl,
478                              CURLOPT_PROXYUSERNAME, s->proxyusername);
479         }
480         if (s->proxypassword) {
481             curl_easy_setopt(state->curl,
482                              CURLOPT_PROXYPASSWORD, s->proxypassword);
483         }
484 
485         /* Restrict supported protocols to avoid security issues in the more
486          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
487          * CVE-2013-0249.
488          *
489          * Restricting protocols is only supported from 7.19.4 upwards.
490          */
491 #if LIBCURL_VERSION_NUM >= 0x071304
492         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
493         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
494 #endif
495 
496 #ifdef DEBUG_VERBOSE
497         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
498 #endif
499     }
500 
501     QLIST_INIT(&state->sockets);
502     state->s = s;
503 
504     return 0;
505 }
506 
507 /* Called with s->mutex held.  */
508 static void curl_clean_state(CURLState *s)
509 {
510     int j;
511     for (j = 0; j < CURL_NUM_ACB; j++) {
512         assert(!s->acb[j]);
513     }
514 
515     if (s->s->multi)
516         curl_multi_remove_handle(s->s->multi, s->curl);
517 
518     while (!QLIST_EMPTY(&s->sockets)) {
519         CURLSocket *socket = QLIST_FIRST(&s->sockets);
520 
521         QLIST_REMOVE(socket, next);
522         g_free(socket);
523     }
524 
525     s->in_use = 0;
526 
527     qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
528 }
529 
530 static void curl_parse_filename(const char *filename, QDict *options,
531                                 Error **errp)
532 {
533     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
534 }
535 
536 static void curl_detach_aio_context(BlockDriverState *bs)
537 {
538     BDRVCURLState *s = bs->opaque;
539     int i;
540 
541     WITH_QEMU_LOCK_GUARD(&s->mutex) {
542         for (i = 0; i < CURL_NUM_STATES; i++) {
543             if (s->states[i].in_use) {
544                 curl_clean_state(&s->states[i]);
545             }
546             if (s->states[i].curl) {
547                 curl_easy_cleanup(s->states[i].curl);
548                 s->states[i].curl = NULL;
549             }
550             g_free(s->states[i].orig_buf);
551             s->states[i].orig_buf = NULL;
552         }
553         if (s->multi) {
554             curl_multi_cleanup(s->multi);
555             s->multi = NULL;
556         }
557     }
558 
559     timer_del(&s->timer);
560 }
561 
562 static void curl_attach_aio_context(BlockDriverState *bs,
563                                     AioContext *new_context)
564 {
565     BDRVCURLState *s = bs->opaque;
566 
567     aio_timer_init(new_context, &s->timer,
568                    QEMU_CLOCK_REALTIME, SCALE_NS,
569                    curl_multi_timeout_do, s);
570 
571     assert(!s->multi);
572     s->multi = curl_multi_init();
573     s->aio_context = new_context;
574     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
575     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
576     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
577 }
578 
579 static QemuOptsList runtime_opts = {
580     .name = "curl",
581     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
582     .desc = {
583         {
584             .name = CURL_BLOCK_OPT_URL,
585             .type = QEMU_OPT_STRING,
586             .help = "URL to open",
587         },
588         {
589             .name = CURL_BLOCK_OPT_READAHEAD,
590             .type = QEMU_OPT_SIZE,
591             .help = "Readahead size",
592         },
593         {
594             .name = CURL_BLOCK_OPT_SSLVERIFY,
595             .type = QEMU_OPT_BOOL,
596             .help = "Verify SSL certificate"
597         },
598         {
599             .name = CURL_BLOCK_OPT_TIMEOUT,
600             .type = QEMU_OPT_NUMBER,
601             .help = "Curl timeout"
602         },
603         {
604             .name = CURL_BLOCK_OPT_COOKIE,
605             .type = QEMU_OPT_STRING,
606             .help = "Pass the cookie or list of cookies with each request"
607         },
608         {
609             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
610             .type = QEMU_OPT_STRING,
611             .help = "ID of secret used as cookie passed with each request"
612         },
613         {
614             .name = CURL_BLOCK_OPT_USERNAME,
615             .type = QEMU_OPT_STRING,
616             .help = "Username for HTTP auth"
617         },
618         {
619             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
620             .type = QEMU_OPT_STRING,
621             .help = "ID of secret used as password for HTTP auth",
622         },
623         {
624             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
625             .type = QEMU_OPT_STRING,
626             .help = "Username for HTTP proxy auth"
627         },
628         {
629             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
630             .type = QEMU_OPT_STRING,
631             .help = "ID of secret used as password for HTTP proxy auth",
632         },
633         { /* end of list */ }
634     },
635 };
636 
637 
638 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
639                      Error **errp)
640 {
641     BDRVCURLState *s = bs->opaque;
642     CURLState *state = NULL;
643     QemuOpts *opts;
644     const char *file;
645     const char *cookie;
646     const char *cookie_secret;
647     double d;
648     const char *secretid;
649     const char *protocol_delimiter;
650     int ret;
651 
652     ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
653                                     errp);
654     if (ret < 0) {
655         return ret;
656     }
657 
658     if (!libcurl_initialized) {
659         ret = curl_global_init(CURL_GLOBAL_ALL);
660         if (ret) {
661             error_setg(errp, "libcurl initialization failed with %d", ret);
662             return -EIO;
663         }
664         libcurl_initialized = true;
665     }
666 
667     qemu_mutex_init(&s->mutex);
668     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
669     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
670         goto out_noclean;
671     }
672 
673     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
674                                           CURL_BLOCK_OPT_READAHEAD_DEFAULT);
675     if ((s->readahead_size & 0x1ff) != 0) {
676         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
677                    s->readahead_size);
678         goto out_noclean;
679     }
680 
681     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
682                                      CURL_BLOCK_OPT_TIMEOUT_DEFAULT);
683     if (s->timeout > CURL_TIMEOUT_MAX) {
684         error_setg(errp, "timeout parameter is too large or negative");
685         goto out_noclean;
686     }
687 
688     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY,
689                                      CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
690 
691     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
692     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
693 
694     if (cookie && cookie_secret) {
695         error_setg(errp,
696                    "curl driver cannot handle both cookie and cookie secret");
697         goto out_noclean;
698     }
699 
700     if (cookie_secret) {
701         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
702         if (!s->cookie) {
703             goto out_noclean;
704         }
705     } else {
706         s->cookie = g_strdup(cookie);
707     }
708 
709     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
710     if (file == NULL) {
711         error_setg(errp, "curl block driver requires an 'url' option");
712         goto out_noclean;
713     }
714 
715     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
716         !strstart(protocol_delimiter, "://", NULL))
717     {
718         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
719                    "start with '%s://')", bs->drv->protocol_name, file,
720                    bs->drv->protocol_name);
721         goto out_noclean;
722     }
723 
724     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
725     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
726 
727     if (secretid) {
728         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
729         if (!s->password) {
730             goto out_noclean;
731         }
732     }
733 
734     s->proxyusername = g_strdup(
735         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
736     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
737     if (secretid) {
738         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
739         if (!s->proxypassword) {
740             goto out_noclean;
741         }
742     }
743 
744     trace_curl_open(file);
745     qemu_co_queue_init(&s->free_state_waitq);
746     s->aio_context = bdrv_get_aio_context(bs);
747     s->url = g_strdup(file);
748     qemu_mutex_lock(&s->mutex);
749     state = curl_find_state(s);
750     qemu_mutex_unlock(&s->mutex);
751     if (!state) {
752         goto out_noclean;
753     }
754 
755     // Get file size
756 
757     if (curl_init_state(s, state) < 0) {
758         goto out;
759     }
760 
761     s->accept_range = false;
762     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
763     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
764                      curl_header_cb);
765     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
766     if (curl_easy_perform(state->curl))
767         goto out;
768     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
769         goto out;
770     }
771     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
772      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
773      * known and zero if it is really zero-length file. */
774 #if LIBCURL_VERSION_NUM >= 0x071304
775     if (d < 0) {
776         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
777                 "Server didn't report file size.");
778         goto out;
779     }
780 #else
781     if (d <= 0) {
782         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
783                 "Unknown file size or zero-length file.");
784         goto out;
785     }
786 #endif
787 
788     s->len = d;
789 
790     if ((!strncasecmp(s->url, "http://", strlen("http://"))
791         || !strncasecmp(s->url, "https://", strlen("https://")))
792         && !s->accept_range) {
793         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
794                 "Server does not support 'range' (byte ranges).");
795         goto out;
796     }
797     trace_curl_open_size(s->len);
798 
799     qemu_mutex_lock(&s->mutex);
800     curl_clean_state(state);
801     qemu_mutex_unlock(&s->mutex);
802     curl_easy_cleanup(state->curl);
803     state->curl = NULL;
804 
805     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
806 
807     qemu_opts_del(opts);
808     return 0;
809 
810 out:
811     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
812     curl_easy_cleanup(state->curl);
813     state->curl = NULL;
814 out_noclean:
815     qemu_mutex_destroy(&s->mutex);
816     g_free(s->cookie);
817     g_free(s->url);
818     g_free(s->username);
819     g_free(s->proxyusername);
820     g_free(s->proxypassword);
821     qemu_opts_del(opts);
822     return -EINVAL;
823 }
824 
825 static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb)
826 {
827     CURLState *state;
828     int running;
829 
830     BDRVCURLState *s = bs->opaque;
831 
832     uint64_t start = acb->offset;
833     uint64_t end;
834 
835     qemu_mutex_lock(&s->mutex);
836 
837     // In case we have the requested data already (e.g. read-ahead),
838     // we can just call the callback and be done.
839     if (curl_find_buf(s, start, acb->bytes, acb)) {
840         goto out;
841     }
842 
843     // No cache found, so let's start a new request
844     for (;;) {
845         state = curl_find_state(s);
846         if (state) {
847             break;
848         }
849         qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
850     }
851 
852     if (curl_init_state(s, state) < 0) {
853         curl_clean_state(state);
854         acb->ret = -EIO;
855         goto out;
856     }
857 
858     acb->start = 0;
859     acb->end = MIN(acb->bytes, s->len - start);
860 
861     state->buf_off = 0;
862     g_free(state->orig_buf);
863     state->buf_start = start;
864     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
865     end = start + state->buf_len - 1;
866     state->orig_buf = g_try_malloc(state->buf_len);
867     if (state->buf_len && state->orig_buf == NULL) {
868         curl_clean_state(state);
869         acb->ret = -ENOMEM;
870         goto out;
871     }
872     state->acb[0] = acb;
873 
874     snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
875     trace_curl_setup_preadv(acb->bytes, start, state->range);
876     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
877 
878     if (curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
879         state->acb[0] = NULL;
880         acb->ret = -EIO;
881 
882         curl_clean_state(state);
883         goto out;
884     }
885 
886     /* Tell curl it needs to kick things off */
887     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
888 
889 out:
890     qemu_mutex_unlock(&s->mutex);
891 }
892 
893 static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
894         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
895 {
896     CURLAIOCB acb = {
897         .co = qemu_coroutine_self(),
898         .ret = -EINPROGRESS,
899         .qiov = qiov,
900         .offset = offset,
901         .bytes = bytes
902     };
903 
904     curl_setup_preadv(bs, &acb);
905     while (acb.ret == -EINPROGRESS) {
906         qemu_coroutine_yield();
907     }
908     return acb.ret;
909 }
910 
911 static void curl_close(BlockDriverState *bs)
912 {
913     BDRVCURLState *s = bs->opaque;
914 
915     trace_curl_close();
916     curl_detach_aio_context(bs);
917     qemu_mutex_destroy(&s->mutex);
918 
919     g_free(s->cookie);
920     g_free(s->url);
921     g_free(s->username);
922     g_free(s->proxyusername);
923     g_free(s->proxypassword);
924 }
925 
926 static int64_t curl_getlength(BlockDriverState *bs)
927 {
928     BDRVCURLState *s = bs->opaque;
929     return s->len;
930 }
931 
932 static void curl_refresh_filename(BlockDriverState *bs)
933 {
934     BDRVCURLState *s = bs->opaque;
935 
936     /* "readahead" and "timeout" do not change the guest-visible data,
937      * so ignore them */
938     if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
939         s->cookie || s->username || s->password || s->proxyusername ||
940         s->proxypassword)
941     {
942         return;
943     }
944 
945     pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
946 }
947 
948 
949 static const char *const curl_strong_runtime_opts[] = {
950     CURL_BLOCK_OPT_URL,
951     CURL_BLOCK_OPT_SSLVERIFY,
952     CURL_BLOCK_OPT_COOKIE,
953     CURL_BLOCK_OPT_COOKIE_SECRET,
954     CURL_BLOCK_OPT_USERNAME,
955     CURL_BLOCK_OPT_PASSWORD_SECRET,
956     CURL_BLOCK_OPT_PROXY_USERNAME,
957     CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
958 
959     NULL
960 };
961 
962 static BlockDriver bdrv_http = {
963     .format_name                = "http",
964     .protocol_name              = "http",
965 
966     .instance_size              = sizeof(BDRVCURLState),
967     .bdrv_parse_filename        = curl_parse_filename,
968     .bdrv_file_open             = curl_open,
969     .bdrv_close                 = curl_close,
970     .bdrv_getlength             = curl_getlength,
971 
972     .bdrv_co_preadv             = curl_co_preadv,
973 
974     .bdrv_detach_aio_context    = curl_detach_aio_context,
975     .bdrv_attach_aio_context    = curl_attach_aio_context,
976 
977     .bdrv_refresh_filename      = curl_refresh_filename,
978     .strong_runtime_opts        = curl_strong_runtime_opts,
979 };
980 
981 static BlockDriver bdrv_https = {
982     .format_name                = "https",
983     .protocol_name              = "https",
984 
985     .instance_size              = sizeof(BDRVCURLState),
986     .bdrv_parse_filename        = curl_parse_filename,
987     .bdrv_file_open             = curl_open,
988     .bdrv_close                 = curl_close,
989     .bdrv_getlength             = curl_getlength,
990 
991     .bdrv_co_preadv             = curl_co_preadv,
992 
993     .bdrv_detach_aio_context    = curl_detach_aio_context,
994     .bdrv_attach_aio_context    = curl_attach_aio_context,
995 
996     .bdrv_refresh_filename      = curl_refresh_filename,
997     .strong_runtime_opts        = curl_strong_runtime_opts,
998 };
999 
1000 static BlockDriver bdrv_ftp = {
1001     .format_name                = "ftp",
1002     .protocol_name              = "ftp",
1003 
1004     .instance_size              = sizeof(BDRVCURLState),
1005     .bdrv_parse_filename        = curl_parse_filename,
1006     .bdrv_file_open             = curl_open,
1007     .bdrv_close                 = curl_close,
1008     .bdrv_getlength             = curl_getlength,
1009 
1010     .bdrv_co_preadv             = curl_co_preadv,
1011 
1012     .bdrv_detach_aio_context    = curl_detach_aio_context,
1013     .bdrv_attach_aio_context    = curl_attach_aio_context,
1014 
1015     .bdrv_refresh_filename      = curl_refresh_filename,
1016     .strong_runtime_opts        = curl_strong_runtime_opts,
1017 };
1018 
1019 static BlockDriver bdrv_ftps = {
1020     .format_name                = "ftps",
1021     .protocol_name              = "ftps",
1022 
1023     .instance_size              = sizeof(BDRVCURLState),
1024     .bdrv_parse_filename        = curl_parse_filename,
1025     .bdrv_file_open             = curl_open,
1026     .bdrv_close                 = curl_close,
1027     .bdrv_getlength             = curl_getlength,
1028 
1029     .bdrv_co_preadv             = curl_co_preadv,
1030 
1031     .bdrv_detach_aio_context    = curl_detach_aio_context,
1032     .bdrv_attach_aio_context    = curl_attach_aio_context,
1033 
1034     .bdrv_refresh_filename      = curl_refresh_filename,
1035     .strong_runtime_opts        = curl_strong_runtime_opts,
1036 };
1037 
1038 static void curl_block_init(void)
1039 {
1040     bdrv_register(&bdrv_http);
1041     bdrv_register(&bdrv_https);
1042     bdrv_register(&bdrv_ftp);
1043     bdrv_register(&bdrv_ftps);
1044 }
1045 
1046 block_init(curl_block_init);
1047