2 * QEMU Block driver for CURL images
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
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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
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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 memcpy(s->orig_buf + s->buf_off, ptr, realsize);
161 s->buf_off += realsize;
163 for(i=0; i<CURL_NUM_ACB; i++) {
164 CURLAIOCB *acb = s->acb[i];
169 if ((s->buf_off >= acb->end)) {
170 qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
171 acb->end - acb->start);
172 acb->common.cb(acb->common.opaque, 0);
173 qemu_aio_release(acb);
182 static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len,
186 size_t end = start + len;
188 for (i=0; i<CURL_NUM_STATES; i++) {
189 CURLState *state = &s->states[i];
190 size_t buf_end = (state->buf_start + state->buf_off);
191 size_t buf_fend = (state->buf_start + state->buf_len);
193 if (!state->orig_buf)
198 // Does the existing buffer cover our section?
199 if ((start >= state->buf_start) &&
200 (start <= buf_end) &&
201 (end >= state->buf_start) &&
204 char *buf = state->orig_buf + (start - state->buf_start);
206 qemu_iovec_from_buf(acb->qiov, 0, buf, len);
207 acb->common.cb(acb->common.opaque, 0);
212 // Wait for unfinished chunks
213 if ((start >= state->buf_start) &&
214 (start <= buf_fend) &&
215 (end >= state->buf_start) &&
220 acb->start = start - state->buf_start;
221 acb->end = acb->start + len;
223 for (j=0; j<CURL_NUM_ACB; j++) {
224 if (!state->acb[j]) {
226 return FIND_RET_WAIT;
232 return FIND_RET_NONE;
235 static void curl_multi_read(BDRVCURLState *s)
239 /* Try to find done transfers, so we can free the easy
243 msg = curl_multi_info_read(s->multi, &msgs_in_queue);
247 if (msg->msg == CURLMSG_NONE)
253 CURLState *state = NULL;
254 curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE, (char**)&state);
256 /* ACBs for successful messages get completed in curl_read_cb */
257 if (msg->data.result != CURLE_OK) {
259 for (i = 0; i < CURL_NUM_ACB; i++) {
260 CURLAIOCB *acb = state->acb[i];
266 acb->common.cb(acb->common.opaque, -EIO);
267 qemu_aio_release(acb);
268 state->acb[i] = NULL;
272 curl_clean_state(state);
279 } while(msgs_in_queue);
282 static void curl_multi_do(void *arg)
284 BDRVCURLState *s = (BDRVCURLState *)arg;
293 r = curl_multi_socket_all(s->multi, &running);
294 } while(r == CURLM_CALL_MULTI_PERFORM);
299 static void curl_multi_timeout_do(void *arg)
301 #ifdef NEED_CURL_TIMER_CALLBACK
302 BDRVCURLState *s = (BDRVCURLState *)arg;
309 curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
317 static CURLState *curl_init_state(BDRVCURLState *s)
319 CURLState *state = NULL;
323 for (i=0; i<CURL_NUM_STATES; i++) {
324 for (j=0; j<CURL_NUM_ACB; j++)
325 if (s->states[i].acb[j])
327 if (s->states[i].in_use)
330 state = &s->states[i];
343 state->curl = curl_easy_init();
346 curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
347 curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, 5);
348 curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, (void *)curl_read_cb);
349 curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
350 curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
351 curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
352 curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
353 curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
354 curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
355 curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
357 /* Restrict supported protocols to avoid security issues in the more
358 * obscure protocols. For example, do not allow POP3/SMTP/IMAP see
361 * Restricting protocols is only supported from 7.19.4 upwards.
363 #if LIBCURL_VERSION_NUM >= 0x071304
364 curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
365 curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
369 curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
379 static void curl_clean_state(CURLState *s)
382 curl_multi_remove_handle(s->s->multi, s->curl);
386 static void curl_parse_filename(const char *filename, QDict *options,
390 #define RA_OPTSTR ":readahead="
396 file = g_strdup(filename);
398 /* Parse a trailing ":readahead=#:" param, if present. */
399 ra = file + strlen(file) - 1;
401 if (parse_state == 0) {
407 } else if (parse_state == 1) {
408 if (*ra > '9' || *ra < '0') {
409 char *opt_start = ra - strlen(RA_OPTSTR) + 1;
410 if (opt_start > file &&
411 strncmp(opt_start, RA_OPTSTR, strlen(RA_OPTSTR)) == 0) {
413 ra -= strlen(RA_OPTSTR) - 1;
415 qdict_put(options, "readahead", qstring_from_str(ra_val));
423 qdict_put(options, "url", qstring_from_str(file));
428 static QemuOptsList runtime_opts = {
430 .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
434 .type = QEMU_OPT_STRING,
435 .help = "URL to open",
439 .type = QEMU_OPT_SIZE,
440 .help = "Readahead size",
442 { /* end of list */ }
446 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
449 BDRVCURLState *s = bs->opaque;
450 CURLState *state = NULL;
452 Error *local_err = NULL;
456 static int inited = 0;
458 if (flags & BDRV_O_RDWR) {
459 error_setg(errp, "curl block device does not support writes");
463 opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
464 qemu_opts_absorb_qdict(opts, options, &local_err);
466 error_propagate(errp, local_err);
470 s->readahead_size = qemu_opt_get_size(opts, "readahead", READ_AHEAD_SIZE);
471 if ((s->readahead_size & 0x1ff) != 0) {
472 error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
477 file = qemu_opt_get(opts, "url");
479 error_setg(errp, "curl block driver requires an 'url' option");
484 curl_global_init(CURL_GLOBAL_ALL);
488 DPRINTF("CURL: Opening %s\n", file);
489 s->url = g_strdup(file);
490 state = curl_init_state(s);
496 s->accept_range = false;
497 curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
498 curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
500 curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
501 if (curl_easy_perform(state->curl))
503 curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d);
508 if ((!strncasecmp(s->url, "http://", strlen("http://"))
509 || !strncasecmp(s->url, "https://", strlen("https://")))
510 && !s->accept_range) {
511 pstrcpy(state->errmsg, CURL_ERROR_SIZE,
512 "Server does not support 'range' (byte ranges).");
515 DPRINTF("CURL: Size = %zd\n", s->len);
517 curl_clean_state(state);
518 curl_easy_cleanup(state->curl);
521 aio_timer_init(bdrv_get_aio_context(bs), &s->timer,
522 QEMU_CLOCK_REALTIME, SCALE_NS,
523 curl_multi_timeout_do, s);
525 // Now we know the file exists and its size, so let's
526 // initialize the multi interface!
528 s->multi = curl_multi_init();
529 curl_multi_setopt(s->multi, CURLMOPT_SOCKETDATA, s);
530 curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
531 #ifdef NEED_CURL_TIMER_CALLBACK
532 curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
533 curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
541 fprintf(stderr, "CURL: Error opening file: %s\n", state->errmsg);
542 curl_easy_cleanup(state->curl);
550 static void curl_aio_cancel(BlockDriverAIOCB *blockacb)
552 // Do we have to implement canceling? Seems to work without...
555 static const AIOCBInfo curl_aiocb_info = {
556 .aiocb_size = sizeof(CURLAIOCB),
557 .cancel = curl_aio_cancel,
561 static void curl_readv_bh_cb(void *p)
566 BDRVCURLState *s = acb->common.bs->opaque;
568 qemu_bh_delete(acb->bh);
571 size_t start = acb->sector_num * SECTOR_SIZE;
574 // In case we have the requested data already (e.g. read-ahead),
575 // we can just call the callback and be done.
576 switch (curl_find_buf(s, start, acb->nb_sectors * SECTOR_SIZE, acb)) {
578 qemu_aio_release(acb);
586 // No cache found, so let's start a new request
587 state = curl_init_state(s);
589 acb->common.cb(acb->common.opaque, -EIO);
590 qemu_aio_release(acb);
595 acb->end = (acb->nb_sectors * SECTOR_SIZE);
599 g_free(state->orig_buf);
600 state->buf_start = start;
601 state->buf_len = acb->end + s->readahead_size;
602 end = MIN(start + state->buf_len, s->len) - 1;
603 state->orig_buf = g_malloc(state->buf_len);
606 snprintf(state->range, 127, "%zd-%zd", start, end);
607 DPRINTF("CURL (AIO): Reading %d at %zd (%s)\n",
608 (acb->nb_sectors * SECTOR_SIZE), start, state->range);
609 curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
611 curl_multi_add_handle(s->multi, state->curl);
616 static BlockDriverAIOCB *curl_aio_readv(BlockDriverState *bs,
617 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
618 BlockDriverCompletionFunc *cb, void *opaque)
622 acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque);
625 acb->sector_num = sector_num;
626 acb->nb_sectors = nb_sectors;
628 acb->bh = qemu_bh_new(curl_readv_bh_cb, acb);
629 qemu_bh_schedule(acb->bh);
633 static void curl_close(BlockDriverState *bs)
635 BDRVCURLState *s = bs->opaque;
638 DPRINTF("CURL: Close\n");
639 for (i=0; i<CURL_NUM_STATES; i++) {
640 if (s->states[i].in_use)
641 curl_clean_state(&s->states[i]);
642 if (s->states[i].curl) {
643 curl_easy_cleanup(s->states[i].curl);
644 s->states[i].curl = NULL;
646 if (s->states[i].orig_buf) {
647 g_free(s->states[i].orig_buf);
648 s->states[i].orig_buf = NULL;
652 curl_multi_cleanup(s->multi);
654 timer_del(&s->timer);
659 static int64_t curl_getlength(BlockDriverState *bs)
661 BDRVCURLState *s = bs->opaque;
665 static BlockDriver bdrv_http = {
666 .format_name = "http",
667 .protocol_name = "http",
669 .instance_size = sizeof(BDRVCURLState),
670 .bdrv_parse_filename = curl_parse_filename,
671 .bdrv_file_open = curl_open,
672 .bdrv_close = curl_close,
673 .bdrv_getlength = curl_getlength,
675 .bdrv_aio_readv = curl_aio_readv,
678 static BlockDriver bdrv_https = {
679 .format_name = "https",
680 .protocol_name = "https",
682 .instance_size = sizeof(BDRVCURLState),
683 .bdrv_parse_filename = curl_parse_filename,
684 .bdrv_file_open = curl_open,
685 .bdrv_close = curl_close,
686 .bdrv_getlength = curl_getlength,
688 .bdrv_aio_readv = curl_aio_readv,
691 static BlockDriver bdrv_ftp = {
692 .format_name = "ftp",
693 .protocol_name = "ftp",
695 .instance_size = sizeof(BDRVCURLState),
696 .bdrv_parse_filename = curl_parse_filename,
697 .bdrv_file_open = curl_open,
698 .bdrv_close = curl_close,
699 .bdrv_getlength = curl_getlength,
701 .bdrv_aio_readv = curl_aio_readv,
704 static BlockDriver bdrv_ftps = {
705 .format_name = "ftps",
706 .protocol_name = "ftps",
708 .instance_size = sizeof(BDRVCURLState),
709 .bdrv_parse_filename = curl_parse_filename,
710 .bdrv_file_open = curl_open,
711 .bdrv_close = curl_close,
712 .bdrv_getlength = curl_getlength,
714 .bdrv_aio_readv = curl_aio_readv,
717 static BlockDriver bdrv_tftp = {
718 .format_name = "tftp",
719 .protocol_name = "tftp",
721 .instance_size = sizeof(BDRVCURLState),
722 .bdrv_parse_filename = curl_parse_filename,
723 .bdrv_file_open = curl_open,
724 .bdrv_close = curl_close,
725 .bdrv_getlength = curl_getlength,
727 .bdrv_aio_readv = curl_aio_readv,
730 static void curl_block_init(void)
732 bdrv_register(&bdrv_http);
733 bdrv_register(&bdrv_https);
734 bdrv_register(&bdrv_ftp);
735 bdrv_register(&bdrv_ftps);
736 bdrv_register(&bdrv_tftp);
739 block_init(curl_block_init);