2 * QEMU Block driver for CURL images
4 * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
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:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
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
24 #include "qemu-common.h"
25 #include "block/block_int.h"
26 #include <curl/curl.h>
29 // #define DEBUG_VERBOSE
32 #define DPRINTF(fmt, ...) do { printf(fmt, ## __VA_ARGS__); } while (0)
34 #define DPRINTF(fmt, ...) do { } while (0)
37 #if LIBCURL_VERSION_NUM >= 0x071000
38 /* The multi interface timer callback was introduced in 7.16.0 */
39 #define NEED_CURL_TIMER_CALLBACK
42 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
43 CURLPROTO_FTP | CURLPROTO_FTPS | \
46 #define CURL_NUM_STATES 8
47 #define CURL_NUM_ACB 8
48 #define SECTOR_SIZE 512
49 #define READ_AHEAD_SIZE (256 * 1024)
51 #define FIND_RET_NONE 0
53 #define FIND_RET_WAIT 2
57 typedef struct CURLAIOCB
{
58 BlockDriverAIOCB common
;
69 typedef struct CURLState
71 struct BDRVCURLState
*s
;
72 CURLAIOCB
*acb
[CURL_NUM_ACB
];
79 char errmsg
[CURL_ERROR_SIZE
];
83 typedef struct BDRVCURLState
{
87 CURLState states
[CURL_NUM_STATES
];
89 size_t readahead_size
;
93 static void curl_clean_state(CURLState
*s
);
94 static void curl_multi_do(void *arg
);
96 #ifdef NEED_CURL_TIMER_CALLBACK
97 static int curl_timer_cb(CURLM
*multi
, long timeout_ms
, void *opaque
)
99 BDRVCURLState
*s
= opaque
;
101 DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms
);
102 if (timeout_ms
== -1) {
103 timer_del(&s
->timer
);
105 int64_t timeout_ns
= (int64_t)timeout_ms
* 1000 * 1000;
107 qemu_clock_get_ns(QEMU_CLOCK_REALTIME
) + timeout_ns
);
113 static int curl_sock_cb(CURL
*curl
, curl_socket_t fd
, int action
,
116 DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action
, fd
);
119 qemu_aio_set_fd_handler(fd
, curl_multi_do
, NULL
, s
);
122 qemu_aio_set_fd_handler(fd
, NULL
, curl_multi_do
, s
);
124 case CURL_POLL_INOUT
:
125 qemu_aio_set_fd_handler(fd
, curl_multi_do
, curl_multi_do
, s
);
127 case CURL_POLL_REMOVE
:
128 qemu_aio_set_fd_handler(fd
, NULL
, NULL
, NULL
);
135 static size_t curl_header_cb(void *ptr
, size_t size
, size_t nmemb
, void *opaque
)
137 BDRVCURLState
*s
= opaque
;
138 size_t realsize
= size
* nmemb
;
139 const char *accept_line
= "Accept-Ranges: bytes";
141 if (realsize
>= strlen(accept_line
)
142 && strncmp((char *)ptr
, accept_line
, strlen(accept_line
)) == 0) {
143 s
->accept_range
= true;
149 static size_t curl_read_cb(void *ptr
, size_t size
, size_t nmemb
, void *opaque
)
151 CURLState
*s
= ((CURLState
*)opaque
);
152 size_t realsize
= size
* nmemb
;
155 DPRINTF("CURL: Just reading %zd bytes\n", realsize
);
157 if (!s
|| !s
->orig_buf
)
160 if (s
->buf_off
>= s
->buf_len
) {
161 /* buffer full, read nothing */
164 realsize
= MIN(realsize
, s
->buf_len
- s
->buf_off
);
165 memcpy(s
->orig_buf
+ s
->buf_off
, ptr
, realsize
);
166 s
->buf_off
+= realsize
;
168 for(i
=0; i
<CURL_NUM_ACB
; i
++) {
169 CURLAIOCB
*acb
= s
->acb
[i
];
174 if ((s
->buf_off
>= acb
->end
)) {
175 qemu_iovec_from_buf(acb
->qiov
, 0, s
->orig_buf
+ acb
->start
,
176 acb
->end
- acb
->start
);
177 acb
->common
.cb(acb
->common
.opaque
, 0);
178 qemu_aio_release(acb
);
186 static int curl_find_buf(BDRVCURLState
*s
, size_t start
, size_t len
,
190 size_t end
= start
+ len
;
192 for (i
=0; i
<CURL_NUM_STATES
; i
++) {
193 CURLState
*state
= &s
->states
[i
];
194 size_t buf_end
= (state
->buf_start
+ state
->buf_off
);
195 size_t buf_fend
= (state
->buf_start
+ state
->buf_len
);
197 if (!state
->orig_buf
)
202 // Does the existing buffer cover our section?
203 if ((start
>= state
->buf_start
) &&
204 (start
<= buf_end
) &&
205 (end
>= state
->buf_start
) &&
208 char *buf
= state
->orig_buf
+ (start
- state
->buf_start
);
210 qemu_iovec_from_buf(acb
->qiov
, 0, buf
, len
);
211 acb
->common
.cb(acb
->common
.opaque
, 0);
216 // Wait for unfinished chunks
217 if ((start
>= state
->buf_start
) &&
218 (start
<= buf_fend
) &&
219 (end
>= state
->buf_start
) &&
224 acb
->start
= start
- state
->buf_start
;
225 acb
->end
= acb
->start
+ len
;
227 for (j
=0; j
<CURL_NUM_ACB
; j
++) {
228 if (!state
->acb
[j
]) {
230 return FIND_RET_WAIT
;
236 return FIND_RET_NONE
;
239 static void curl_multi_read(BDRVCURLState
*s
)
243 /* Try to find done transfers, so we can free the easy
247 msg
= curl_multi_info_read(s
->multi
, &msgs_in_queue
);
251 if (msg
->msg
== CURLMSG_NONE
)
257 CURLState
*state
= NULL
;
258 curl_easy_getinfo(msg
->easy_handle
, CURLINFO_PRIVATE
,
261 /* ACBs for successful messages get completed in curl_read_cb */
262 if (msg
->data
.result
!= CURLE_OK
) {
264 for (i
= 0; i
< CURL_NUM_ACB
; i
++) {
265 CURLAIOCB
*acb
= state
->acb
[i
];
271 acb
->common
.cb(acb
->common
.opaque
, -EIO
);
272 qemu_aio_release(acb
);
273 state
->acb
[i
] = NULL
;
277 curl_clean_state(state
);
284 } while(msgs_in_queue
);
287 static void curl_multi_do(void *arg
)
289 BDRVCURLState
*s
= (BDRVCURLState
*)arg
;
298 r
= curl_multi_socket_all(s
->multi
, &running
);
299 } while(r
== CURLM_CALL_MULTI_PERFORM
);
304 static void curl_multi_timeout_do(void *arg
)
306 #ifdef NEED_CURL_TIMER_CALLBACK
307 BDRVCURLState
*s
= (BDRVCURLState
*)arg
;
314 curl_multi_socket_action(s
->multi
, CURL_SOCKET_TIMEOUT
, 0, &running
);
322 static CURLState
*curl_init_state(BDRVCURLState
*s
)
324 CURLState
*state
= NULL
;
328 for (i
=0; i
<CURL_NUM_STATES
; i
++) {
329 for (j
=0; j
<CURL_NUM_ACB
; j
++)
330 if (s
->states
[i
].acb
[j
])
332 if (s
->states
[i
].in_use
)
335 state
= &s
->states
[i
];
345 state
->curl
= curl_easy_init();
349 curl_easy_setopt(state
->curl
, CURLOPT_URL
, s
->url
);
350 curl_easy_setopt(state
->curl
, CURLOPT_TIMEOUT
, 5);
351 curl_easy_setopt(state
->curl
, CURLOPT_WRITEFUNCTION
,
352 (void *)curl_read_cb
);
353 curl_easy_setopt(state
->curl
, CURLOPT_WRITEDATA
, (void *)state
);
354 curl_easy_setopt(state
->curl
, CURLOPT_PRIVATE
, (void *)state
);
355 curl_easy_setopt(state
->curl
, CURLOPT_AUTOREFERER
, 1);
356 curl_easy_setopt(state
->curl
, CURLOPT_FOLLOWLOCATION
, 1);
357 curl_easy_setopt(state
->curl
, CURLOPT_NOSIGNAL
, 1);
358 curl_easy_setopt(state
->curl
, CURLOPT_ERRORBUFFER
, state
->errmsg
);
359 curl_easy_setopt(state
->curl
, CURLOPT_FAILONERROR
, 1);
361 /* Restrict supported protocols to avoid security issues in the more
362 * obscure protocols. For example, do not allow POP3/SMTP/IMAP see
365 * Restricting protocols is only supported from 7.19.4 upwards.
367 #if LIBCURL_VERSION_NUM >= 0x071304
368 curl_easy_setopt(state
->curl
, CURLOPT_PROTOCOLS
, PROTOCOLS
);
369 curl_easy_setopt(state
->curl
, CURLOPT_REDIR_PROTOCOLS
, PROTOCOLS
);
373 curl_easy_setopt(state
->curl
, CURLOPT_VERBOSE
, 1);
382 static void curl_clean_state(CURLState
*s
)
385 curl_multi_remove_handle(s
->s
->multi
, s
->curl
);
389 static void curl_parse_filename(const char *filename
, QDict
*options
,
393 #define RA_OPTSTR ":readahead="
399 file
= g_strdup(filename
);
401 /* Parse a trailing ":readahead=#:" param, if present. */
402 ra
= file
+ strlen(file
) - 1;
404 if (parse_state
== 0) {
410 } else if (parse_state
== 1) {
411 if (*ra
> '9' || *ra
< '0') {
412 char *opt_start
= ra
- strlen(RA_OPTSTR
) + 1;
413 if (opt_start
> file
&&
414 strncmp(opt_start
, RA_OPTSTR
, strlen(RA_OPTSTR
)) == 0) {
416 ra
-= strlen(RA_OPTSTR
) - 1;
418 qdict_put(options
, "readahead", qstring_from_str(ra_val
));
426 qdict_put(options
, "url", qstring_from_str(file
));
431 static QemuOptsList runtime_opts
= {
433 .head
= QTAILQ_HEAD_INITIALIZER(runtime_opts
.head
),
437 .type
= QEMU_OPT_STRING
,
438 .help
= "URL to open",
442 .type
= QEMU_OPT_SIZE
,
443 .help
= "Readahead size",
445 { /* end of list */ }
449 static int curl_open(BlockDriverState
*bs
, QDict
*options
, int flags
,
452 BDRVCURLState
*s
= bs
->opaque
;
453 CURLState
*state
= NULL
;
455 Error
*local_err
= NULL
;
459 static int inited
= 0;
461 if (flags
& BDRV_O_RDWR
) {
462 error_setg(errp
, "curl block device does not support writes");
466 opts
= qemu_opts_create(&runtime_opts
, NULL
, 0, &error_abort
);
467 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
469 error_propagate(errp
, local_err
);
473 s
->readahead_size
= qemu_opt_get_size(opts
, "readahead", READ_AHEAD_SIZE
);
474 if ((s
->readahead_size
& 0x1ff) != 0) {
475 error_setg(errp
, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
480 file
= qemu_opt_get(opts
, "url");
482 error_setg(errp
, "curl block driver requires an 'url' option");
487 curl_global_init(CURL_GLOBAL_ALL
);
491 DPRINTF("CURL: Opening %s\n", file
);
492 s
->url
= g_strdup(file
);
493 state
= curl_init_state(s
);
499 s
->accept_range
= false;
500 curl_easy_setopt(state
->curl
, CURLOPT_NOBODY
, 1);
501 curl_easy_setopt(state
->curl
, CURLOPT_HEADERFUNCTION
,
503 curl_easy_setopt(state
->curl
, CURLOPT_HEADERDATA
, s
);
504 if (curl_easy_perform(state
->curl
))
506 curl_easy_getinfo(state
->curl
, CURLINFO_CONTENT_LENGTH_DOWNLOAD
, &d
);
511 if ((!strncasecmp(s
->url
, "http://", strlen("http://"))
512 || !strncasecmp(s
->url
, "https://", strlen("https://")))
513 && !s
->accept_range
) {
514 pstrcpy(state
->errmsg
, CURL_ERROR_SIZE
,
515 "Server does not support 'range' (byte ranges).");
518 DPRINTF("CURL: Size = %zd\n", s
->len
);
520 curl_clean_state(state
);
521 curl_easy_cleanup(state
->curl
);
524 aio_timer_init(bdrv_get_aio_context(bs
), &s
->timer
,
525 QEMU_CLOCK_REALTIME
, SCALE_NS
,
526 curl_multi_timeout_do
, s
);
528 // Now we know the file exists and its size, so let's
529 // initialize the multi interface!
531 s
->multi
= curl_multi_init();
532 curl_multi_setopt(s
->multi
, CURLMOPT_SOCKETDATA
, s
);
533 curl_multi_setopt(s
->multi
, CURLMOPT_SOCKETFUNCTION
, curl_sock_cb
);
534 #ifdef NEED_CURL_TIMER_CALLBACK
535 curl_multi_setopt(s
->multi
, CURLMOPT_TIMERDATA
, s
);
536 curl_multi_setopt(s
->multi
, CURLMOPT_TIMERFUNCTION
, curl_timer_cb
);
543 error_setg(errp
, "CURL: Error opening file: %s", state
->errmsg
);
544 curl_easy_cleanup(state
->curl
);
552 static void curl_aio_cancel(BlockDriverAIOCB
*blockacb
)
554 // Do we have to implement canceling? Seems to work without...
557 static const AIOCBInfo curl_aiocb_info
= {
558 .aiocb_size
= sizeof(CURLAIOCB
),
559 .cancel
= curl_aio_cancel
,
563 static void curl_readv_bh_cb(void *p
)
569 BDRVCURLState
*s
= acb
->common
.bs
->opaque
;
571 qemu_bh_delete(acb
->bh
);
574 size_t start
= acb
->sector_num
* SECTOR_SIZE
;
577 // In case we have the requested data already (e.g. read-ahead),
578 // we can just call the callback and be done.
579 switch (curl_find_buf(s
, start
, acb
->nb_sectors
* SECTOR_SIZE
, acb
)) {
581 qemu_aio_release(acb
);
589 // No cache found, so let's start a new request
590 state
= curl_init_state(s
);
592 acb
->common
.cb(acb
->common
.opaque
, -EIO
);
593 qemu_aio_release(acb
);
598 acb
->end
= (acb
->nb_sectors
* SECTOR_SIZE
);
602 g_free(state
->orig_buf
);
603 state
->buf_start
= start
;
604 state
->buf_len
= acb
->end
+ s
->readahead_size
;
605 end
= MIN(start
+ state
->buf_len
, s
->len
) - 1;
606 state
->orig_buf
= g_malloc(state
->buf_len
);
609 snprintf(state
->range
, 127, "%zd-%zd", start
, end
);
610 DPRINTF("CURL (AIO): Reading %d at %zd (%s)\n",
611 (acb
->nb_sectors
* SECTOR_SIZE
), start
, state
->range
);
612 curl_easy_setopt(state
->curl
, CURLOPT_RANGE
, state
->range
);
614 curl_multi_add_handle(s
->multi
, state
->curl
);
616 /* Tell curl it needs to kick things off */
617 curl_multi_socket_action(s
->multi
, CURL_SOCKET_TIMEOUT
, 0, &running
);
620 static BlockDriverAIOCB
*curl_aio_readv(BlockDriverState
*bs
,
621 int64_t sector_num
, QEMUIOVector
*qiov
, int nb_sectors
,
622 BlockDriverCompletionFunc
*cb
, void *opaque
)
626 acb
= qemu_aio_get(&curl_aiocb_info
, bs
, cb
, opaque
);
629 acb
->sector_num
= sector_num
;
630 acb
->nb_sectors
= nb_sectors
;
632 acb
->bh
= qemu_bh_new(curl_readv_bh_cb
, acb
);
633 qemu_bh_schedule(acb
->bh
);
637 static void curl_close(BlockDriverState
*bs
)
639 BDRVCURLState
*s
= bs
->opaque
;
642 DPRINTF("CURL: Close\n");
643 for (i
=0; i
<CURL_NUM_STATES
; i
++) {
644 if (s
->states
[i
].in_use
)
645 curl_clean_state(&s
->states
[i
]);
646 if (s
->states
[i
].curl
) {
647 curl_easy_cleanup(s
->states
[i
].curl
);
648 s
->states
[i
].curl
= NULL
;
650 if (s
->states
[i
].orig_buf
) {
651 g_free(s
->states
[i
].orig_buf
);
652 s
->states
[i
].orig_buf
= NULL
;
656 curl_multi_cleanup(s
->multi
);
658 timer_del(&s
->timer
);
663 static int64_t curl_getlength(BlockDriverState
*bs
)
665 BDRVCURLState
*s
= bs
->opaque
;
669 static BlockDriver bdrv_http
= {
670 .format_name
= "http",
671 .protocol_name
= "http",
673 .instance_size
= sizeof(BDRVCURLState
),
674 .bdrv_parse_filename
= curl_parse_filename
,
675 .bdrv_file_open
= curl_open
,
676 .bdrv_close
= curl_close
,
677 .bdrv_getlength
= curl_getlength
,
679 .bdrv_aio_readv
= curl_aio_readv
,
682 static BlockDriver bdrv_https
= {
683 .format_name
= "https",
684 .protocol_name
= "https",
686 .instance_size
= sizeof(BDRVCURLState
),
687 .bdrv_parse_filename
= curl_parse_filename
,
688 .bdrv_file_open
= curl_open
,
689 .bdrv_close
= curl_close
,
690 .bdrv_getlength
= curl_getlength
,
692 .bdrv_aio_readv
= curl_aio_readv
,
695 static BlockDriver bdrv_ftp
= {
696 .format_name
= "ftp",
697 .protocol_name
= "ftp",
699 .instance_size
= sizeof(BDRVCURLState
),
700 .bdrv_parse_filename
= curl_parse_filename
,
701 .bdrv_file_open
= curl_open
,
702 .bdrv_close
= curl_close
,
703 .bdrv_getlength
= curl_getlength
,
705 .bdrv_aio_readv
= curl_aio_readv
,
708 static BlockDriver bdrv_ftps
= {
709 .format_name
= "ftps",
710 .protocol_name
= "ftps",
712 .instance_size
= sizeof(BDRVCURLState
),
713 .bdrv_parse_filename
= curl_parse_filename
,
714 .bdrv_file_open
= curl_open
,
715 .bdrv_close
= curl_close
,
716 .bdrv_getlength
= curl_getlength
,
718 .bdrv_aio_readv
= curl_aio_readv
,
721 static BlockDriver bdrv_tftp
= {
722 .format_name
= "tftp",
723 .protocol_name
= "tftp",
725 .instance_size
= sizeof(BDRVCURLState
),
726 .bdrv_parse_filename
= curl_parse_filename
,
727 .bdrv_file_open
= curl_open
,
728 .bdrv_close
= curl_close
,
729 .bdrv_getlength
= curl_getlength
,
731 .bdrv_aio_readv
= curl_aio_readv
,
734 static void curl_block_init(void)
736 bdrv_register(&bdrv_http
);
737 bdrv_register(&bdrv_https
);
738 bdrv_register(&bdrv_ftp
);
739 bdrv_register(&bdrv_ftps
);
740 bdrv_register(&bdrv_tftp
);
743 block_init(curl_block_init
);