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25#include "qemu/osdep.h"
26
27#include <libssh2.h>
28#include <libssh2_sftp.h>
29
30#include "block/block_int.h"
31#include "qapi/error.h"
32#include "qemu/error-report.h"
33#include "qemu/sockets.h"
34#include "qemu/uri.h"
35#include "qapi/qmp/qint.h"
36#include "qapi/qmp/qstring.h"
37
38
39
40
41
42
43
44
45
46
47#define DEBUG_SSH 0
48#define TRACE_LIBSSH2 0
49
50#define DPRINTF(fmt, ...) \
51 do { \
52 if (DEBUG_SSH) { \
53 fprintf(stderr, "ssh: %-15s " fmt "\n", \
54 __func__, ##__VA_ARGS__); \
55 } \
56 } while (0)
57
58typedef struct BDRVSSHState {
59
60 CoMutex lock;
61
62
63 int sock;
64 LIBSSH2_SESSION *session;
65 LIBSSH2_SFTP *sftp;
66 LIBSSH2_SFTP_HANDLE *sftp_handle;
67
68
69 int64_t offset;
70 bool offset_op_read;
71
72
73
74
75 LIBSSH2_SFTP_ATTRIBUTES attrs;
76
77
78 char *hostport;
79 bool unsafe_flush_warning;
80} BDRVSSHState;
81
82static void ssh_state_init(BDRVSSHState *s)
83{
84 memset(s, 0, sizeof *s);
85 s->sock = -1;
86 s->offset = -1;
87 qemu_co_mutex_init(&s->lock);
88}
89
90static void ssh_state_free(BDRVSSHState *s)
91{
92 g_free(s->hostport);
93 if (s->sftp_handle) {
94 libssh2_sftp_close(s->sftp_handle);
95 }
96 if (s->sftp) {
97 libssh2_sftp_shutdown(s->sftp);
98 }
99 if (s->session) {
100 libssh2_session_disconnect(s->session,
101 "from qemu ssh client: "
102 "user closed the connection");
103 libssh2_session_free(s->session);
104 }
105 if (s->sock >= 0) {
106 close(s->sock);
107 }
108}
109
110static void GCC_FMT_ATTR(3, 4)
111session_error_setg(Error **errp, BDRVSSHState *s, const char *fs, ...)
112{
113 va_list args;
114 char *msg;
115
116 va_start(args, fs);
117 msg = g_strdup_vprintf(fs, args);
118 va_end(args);
119
120 if (s->session) {
121 char *ssh_err;
122 int ssh_err_code;
123
124
125 ssh_err_code = libssh2_session_last_error(s->session,
126 &ssh_err, NULL, 0);
127 error_setg(errp, "%s: %s (libssh2 error code: %d)",
128 msg, ssh_err, ssh_err_code);
129 } else {
130 error_setg(errp, "%s", msg);
131 }
132 g_free(msg);
133}
134
135static void GCC_FMT_ATTR(3, 4)
136sftp_error_setg(Error **errp, BDRVSSHState *s, const char *fs, ...)
137{
138 va_list args;
139 char *msg;
140
141 va_start(args, fs);
142 msg = g_strdup_vprintf(fs, args);
143 va_end(args);
144
145 if (s->sftp) {
146 char *ssh_err;
147 int ssh_err_code;
148 unsigned long sftp_err_code;
149
150
151 ssh_err_code = libssh2_session_last_error(s->session,
152 &ssh_err, NULL, 0);
153
154 sftp_err_code = libssh2_sftp_last_error((s)->sftp);
155
156 error_setg(errp,
157 "%s: %s (libssh2 error code: %d, sftp error code: %lu)",
158 msg, ssh_err, ssh_err_code, sftp_err_code);
159 } else {
160 error_setg(errp, "%s", msg);
161 }
162 g_free(msg);
163}
164
165static void GCC_FMT_ATTR(2, 3)
166sftp_error_report(BDRVSSHState *s, const char *fs, ...)
167{
168 va_list args;
169
170 va_start(args, fs);
171 error_vprintf(fs, args);
172
173 if ((s)->sftp) {
174 char *ssh_err;
175 int ssh_err_code;
176 unsigned long sftp_err_code;
177
178
179 ssh_err_code = libssh2_session_last_error(s->session,
180 &ssh_err, NULL, 0);
181
182 sftp_err_code = libssh2_sftp_last_error((s)->sftp);
183
184 error_printf(": %s (libssh2 error code: %d, sftp error code: %lu)",
185 ssh_err, ssh_err_code, sftp_err_code);
186 }
187
188 va_end(args);
189 error_printf("\n");
190}
191
192static int parse_uri(const char *filename, QDict *options, Error **errp)
193{
194 URI *uri = NULL;
195 QueryParams *qp;
196 int i;
197
198 uri = uri_parse(filename);
199 if (!uri) {
200 return -EINVAL;
201 }
202
203 if (strcmp(uri->scheme, "ssh") != 0) {
204 error_setg(errp, "URI scheme must be 'ssh'");
205 goto err;
206 }
207
208 if (!uri->server || strcmp(uri->server, "") == 0) {
209 error_setg(errp, "missing hostname in URI");
210 goto err;
211 }
212
213 if (!uri->path || strcmp(uri->path, "") == 0) {
214 error_setg(errp, "missing remote path in URI");
215 goto err;
216 }
217
218 qp = query_params_parse(uri->query);
219 if (!qp) {
220 error_setg(errp, "could not parse query parameters");
221 goto err;
222 }
223
224 if(uri->user && strcmp(uri->user, "") != 0) {
225 qdict_put(options, "user", qstring_from_str(uri->user));
226 }
227
228 qdict_put(options, "host", qstring_from_str(uri->server));
229
230 if (uri->port) {
231 qdict_put(options, "port", qint_from_int(uri->port));
232 }
233
234 qdict_put(options, "path", qstring_from_str(uri->path));
235
236
237
238
239 for (i = 0; i < qp->n; ++i) {
240 if (strcmp(qp->p[i].name, "host_key_check") == 0) {
241 qdict_put(options, "host_key_check",
242 qstring_from_str(qp->p[i].value));
243 }
244 }
245
246 query_params_free(qp);
247 uri_free(uri);
248 return 0;
249
250 err:
251 if (uri) {
252 uri_free(uri);
253 }
254 return -EINVAL;
255}
256
257static void ssh_parse_filename(const char *filename, QDict *options,
258 Error **errp)
259{
260 if (qdict_haskey(options, "user") ||
261 qdict_haskey(options, "host") ||
262 qdict_haskey(options, "port") ||
263 qdict_haskey(options, "path") ||
264 qdict_haskey(options, "host_key_check")) {
265 error_setg(errp, "user, host, port, path, host_key_check cannot be used at the same time as a file option");
266 return;
267 }
268
269 parse_uri(filename, options, errp);
270}
271
272static int check_host_key_knownhosts(BDRVSSHState *s,
273 const char *host, int port, Error **errp)
274{
275 const char *home;
276 char *knh_file = NULL;
277 LIBSSH2_KNOWNHOSTS *knh = NULL;
278 struct libssh2_knownhost *found;
279 int ret, r;
280 const char *hostkey;
281 size_t len;
282 int type;
283
284 hostkey = libssh2_session_hostkey(s->session, &len, &type);
285 if (!hostkey) {
286 ret = -EINVAL;
287 session_error_setg(errp, s, "failed to read remote host key");
288 goto out;
289 }
290
291 knh = libssh2_knownhost_init(s->session);
292 if (!knh) {
293 ret = -EINVAL;
294 session_error_setg(errp, s,
295 "failed to initialize known hosts support");
296 goto out;
297 }
298
299 home = getenv("HOME");
300 if (home) {
301 knh_file = g_strdup_printf("%s/.ssh/known_hosts", home);
302 } else {
303 knh_file = g_strdup_printf("/root/.ssh/known_hosts");
304 }
305
306
307 libssh2_knownhost_readfile(knh, knh_file, LIBSSH2_KNOWNHOST_FILE_OPENSSH);
308
309 r = libssh2_knownhost_checkp(knh, host, port, hostkey, len,
310 LIBSSH2_KNOWNHOST_TYPE_PLAIN|
311 LIBSSH2_KNOWNHOST_KEYENC_RAW,
312 &found);
313 switch (r) {
314 case LIBSSH2_KNOWNHOST_CHECK_MATCH:
315
316 DPRINTF("host key OK: %s", found->key);
317 break;
318 case LIBSSH2_KNOWNHOST_CHECK_MISMATCH:
319 ret = -EINVAL;
320 session_error_setg(errp, s,
321 "host key does not match the one in known_hosts"
322 " (found key %s)", found->key);
323 goto out;
324 case LIBSSH2_KNOWNHOST_CHECK_NOTFOUND:
325 ret = -EINVAL;
326 session_error_setg(errp, s, "no host key was found in known_hosts");
327 goto out;
328 case LIBSSH2_KNOWNHOST_CHECK_FAILURE:
329 ret = -EINVAL;
330 session_error_setg(errp, s,
331 "failure matching the host key with known_hosts");
332 goto out;
333 default:
334 ret = -EINVAL;
335 session_error_setg(errp, s, "unknown error matching the host key"
336 " with known_hosts (%d)", r);
337 goto out;
338 }
339
340
341 ret = 0;
342
343 out:
344 if (knh != NULL) {
345 libssh2_knownhost_free(knh);
346 }
347 g_free(knh_file);
348 return ret;
349}
350
351static unsigned hex2decimal(char ch)
352{
353 if (ch >= '0' && ch <= '9') {
354 return (ch - '0');
355 } else if (ch >= 'a' && ch <= 'f') {
356 return 10 + (ch - 'a');
357 } else if (ch >= 'A' && ch <= 'F') {
358 return 10 + (ch - 'A');
359 }
360
361 return -1;
362}
363
364
365
366
367static int compare_fingerprint(const unsigned char *fingerprint, size_t len,
368 const char *host_key_check)
369{
370 unsigned c;
371
372 while (len > 0) {
373 while (*host_key_check == ':')
374 host_key_check++;
375 if (!qemu_isxdigit(host_key_check[0]) ||
376 !qemu_isxdigit(host_key_check[1]))
377 return 1;
378 c = hex2decimal(host_key_check[0]) * 16 +
379 hex2decimal(host_key_check[1]);
380 if (c - *fingerprint != 0)
381 return c - *fingerprint;
382 fingerprint++;
383 len--;
384 host_key_check += 2;
385 }
386 return *host_key_check - '\0';
387}
388
389static int
390check_host_key_hash(BDRVSSHState *s, const char *hash,
391 int hash_type, size_t fingerprint_len, Error **errp)
392{
393 const char *fingerprint;
394
395 fingerprint = libssh2_hostkey_hash(s->session, hash_type);
396 if (!fingerprint) {
397 session_error_setg(errp, s, "failed to read remote host key");
398 return -EINVAL;
399 }
400
401 if(compare_fingerprint((unsigned char *) fingerprint, fingerprint_len,
402 hash) != 0) {
403 error_setg(errp, "remote host key does not match host_key_check '%s'",
404 hash);
405 return -EPERM;
406 }
407
408 return 0;
409}
410
411static int check_host_key(BDRVSSHState *s, const char *host, int port,
412 const char *host_key_check, Error **errp)
413{
414
415 if (strcmp(host_key_check, "no") == 0) {
416 return 0;
417 }
418
419
420 if (strncmp(host_key_check, "md5:", 4) == 0) {
421 return check_host_key_hash(s, &host_key_check[4],
422 LIBSSH2_HOSTKEY_HASH_MD5, 16, errp);
423 }
424
425
426 if (strncmp(host_key_check, "sha1:", 5) == 0) {
427 return check_host_key_hash(s, &host_key_check[5],
428 LIBSSH2_HOSTKEY_HASH_SHA1, 20, errp);
429 }
430
431
432 if (strcmp(host_key_check, "yes") == 0) {
433 return check_host_key_knownhosts(s, host, port, errp);
434 }
435
436 error_setg(errp, "unknown host_key_check setting (%s)", host_key_check);
437 return -EINVAL;
438}
439
440static int authenticate(BDRVSSHState *s, const char *user, Error **errp)
441{
442 int r, ret;
443 const char *userauthlist;
444 LIBSSH2_AGENT *agent = NULL;
445 struct libssh2_agent_publickey *identity;
446 struct libssh2_agent_publickey *prev_identity = NULL;
447
448 userauthlist = libssh2_userauth_list(s->session, user, strlen(user));
449 if (strstr(userauthlist, "publickey") == NULL) {
450 ret = -EPERM;
451 error_setg(errp,
452 "remote server does not support \"publickey\" authentication");
453 goto out;
454 }
455
456
457 agent = libssh2_agent_init(s->session);
458 if (!agent) {
459 ret = -EINVAL;
460 session_error_setg(errp, s, "failed to initialize ssh-agent support");
461 goto out;
462 }
463 if (libssh2_agent_connect(agent)) {
464 ret = -ECONNREFUSED;
465 session_error_setg(errp, s, "failed to connect to ssh-agent");
466 goto out;
467 }
468 if (libssh2_agent_list_identities(agent)) {
469 ret = -EINVAL;
470 session_error_setg(errp, s,
471 "failed requesting identities from ssh-agent");
472 goto out;
473 }
474
475 for(;;) {
476 r = libssh2_agent_get_identity(agent, &identity, prev_identity);
477 if (r == 1) {
478 break;
479 }
480 if (r < 0) {
481 ret = -EINVAL;
482 session_error_setg(errp, s,
483 "failed to obtain identity from ssh-agent");
484 goto out;
485 }
486 r = libssh2_agent_userauth(agent, user, identity);
487 if (r == 0) {
488
489 ret = 0;
490 goto out;
491 }
492
493 prev_identity = identity;
494 }
495
496 ret = -EPERM;
497 error_setg(errp, "failed to authenticate using publickey authentication "
498 "and the identities held by your ssh-agent");
499
500 out:
501 if (agent != NULL) {
502
503
504
505 libssh2_agent_free(agent);
506 }
507
508 return ret;
509}
510
511static int connect_to_ssh(BDRVSSHState *s, QDict *options,
512 int ssh_flags, int creat_mode, Error **errp)
513{
514 int r, ret;
515 const char *host, *user, *path, *host_key_check;
516 int port;
517
518 if (!qdict_haskey(options, "host")) {
519 ret = -EINVAL;
520 error_setg(errp, "No hostname was specified");
521 goto err;
522 }
523 host = qdict_get_str(options, "host");
524
525 if (qdict_haskey(options, "port")) {
526 port = qdict_get_int(options, "port");
527 } else {
528 port = 22;
529 }
530
531 if (!qdict_haskey(options, "path")) {
532 ret = -EINVAL;
533 error_setg(errp, "No path was specified");
534 goto err;
535 }
536 path = qdict_get_str(options, "path");
537
538 if (qdict_haskey(options, "user")) {
539 user = qdict_get_str(options, "user");
540 } else {
541 user = g_get_user_name();
542 if (!user) {
543 error_setg_errno(errp, errno, "Can't get user name");
544 ret = -errno;
545 goto err;
546 }
547 }
548
549 if (qdict_haskey(options, "host_key_check")) {
550 host_key_check = qdict_get_str(options, "host_key_check");
551 } else {
552 host_key_check = "yes";
553 }
554
555
556 g_free(s->hostport);
557 s->hostport = g_strdup_printf("%s:%d", host, port);
558
559
560 s->sock = inet_connect(s->hostport, errp);
561 if (s->sock < 0) {
562 ret = -EIO;
563 goto err;
564 }
565
566
567 s->session = libssh2_session_init();
568 if (!s->session) {
569 ret = -EINVAL;
570 session_error_setg(errp, s, "failed to initialize libssh2 session");
571 goto err;
572 }
573
574#if TRACE_LIBSSH2 != 0
575 libssh2_trace(s->session, TRACE_LIBSSH2);
576#endif
577
578 r = libssh2_session_handshake(s->session, s->sock);
579 if (r != 0) {
580 ret = -EINVAL;
581 session_error_setg(errp, s, "failed to establish SSH session");
582 goto err;
583 }
584
585
586 ret = check_host_key(s, host, port, host_key_check, errp);
587 if (ret < 0) {
588 goto err;
589 }
590
591
592 ret = authenticate(s, user, errp);
593 if (ret < 0) {
594 goto err;
595 }
596
597
598 s->sftp = libssh2_sftp_init(s->session);
599 if (!s->sftp) {
600 session_error_setg(errp, s, "failed to initialize sftp handle");
601 ret = -EINVAL;
602 goto err;
603 }
604
605
606 DPRINTF("opening file %s flags=0x%x creat_mode=0%o",
607 path, ssh_flags, creat_mode);
608 s->sftp_handle = libssh2_sftp_open(s->sftp, path, ssh_flags, creat_mode);
609 if (!s->sftp_handle) {
610 session_error_setg(errp, s, "failed to open remote file '%s'", path);
611 ret = -EINVAL;
612 goto err;
613 }
614
615 r = libssh2_sftp_fstat(s->sftp_handle, &s->attrs);
616 if (r < 0) {
617 sftp_error_setg(errp, s, "failed to read file attributes");
618 return -EINVAL;
619 }
620
621
622
623
624 qdict_del(options, "host");
625 qdict_del(options, "port");
626 qdict_del(options, "user");
627 qdict_del(options, "path");
628 qdict_del(options, "host_key_check");
629
630 return 0;
631
632 err:
633 if (s->sftp_handle) {
634 libssh2_sftp_close(s->sftp_handle);
635 }
636 s->sftp_handle = NULL;
637 if (s->sftp) {
638 libssh2_sftp_shutdown(s->sftp);
639 }
640 s->sftp = NULL;
641 if (s->session) {
642 libssh2_session_disconnect(s->session,
643 "from qemu ssh client: "
644 "error opening connection");
645 libssh2_session_free(s->session);
646 }
647 s->session = NULL;
648
649 return ret;
650}
651
652static int ssh_file_open(BlockDriverState *bs, QDict *options, int bdrv_flags,
653 Error **errp)
654{
655 BDRVSSHState *s = bs->opaque;
656 int ret;
657 int ssh_flags;
658
659 ssh_state_init(s);
660
661 ssh_flags = LIBSSH2_FXF_READ;
662 if (bdrv_flags & BDRV_O_RDWR) {
663 ssh_flags |= LIBSSH2_FXF_WRITE;
664 }
665
666
667 ret = connect_to_ssh(s, options, ssh_flags, 0, errp);
668 if (ret < 0) {
669 goto err;
670 }
671
672
673 libssh2_session_set_blocking(s->session, 0);
674
675 return 0;
676
677 err:
678 if (s->sock >= 0) {
679 close(s->sock);
680 }
681 s->sock = -1;
682
683 return ret;
684}
685
686static QemuOptsList ssh_create_opts = {
687 .name = "ssh-create-opts",
688 .head = QTAILQ_HEAD_INITIALIZER(ssh_create_opts.head),
689 .desc = {
690 {
691 .name = BLOCK_OPT_SIZE,
692 .type = QEMU_OPT_SIZE,
693 .help = "Virtual disk size"
694 },
695 { }
696 }
697};
698
699static int ssh_create(const char *filename, QemuOpts *opts, Error **errp)
700{
701 int r, ret;
702 int64_t total_size = 0;
703 QDict *uri_options = NULL;
704 BDRVSSHState s;
705 ssize_t r2;
706 char c[1] = { '\0' };
707
708 ssh_state_init(&s);
709
710
711 total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
712 BDRV_SECTOR_SIZE);
713 DPRINTF("total_size=%" PRIi64, total_size);
714
715 uri_options = qdict_new();
716 r = parse_uri(filename, uri_options, errp);
717 if (r < 0) {
718 ret = r;
719 goto out;
720 }
721
722 r = connect_to_ssh(&s, uri_options,
723 LIBSSH2_FXF_READ|LIBSSH2_FXF_WRITE|
724 LIBSSH2_FXF_CREAT|LIBSSH2_FXF_TRUNC,
725 0644, errp);
726 if (r < 0) {
727 ret = r;
728 goto out;
729 }
730
731 if (total_size > 0) {
732 libssh2_sftp_seek64(s.sftp_handle, total_size-1);
733 r2 = libssh2_sftp_write(s.sftp_handle, c, 1);
734 if (r2 < 0) {
735 sftp_error_setg(errp, &s, "truncate failed");
736 ret = -EINVAL;
737 goto out;
738 }
739 s.attrs.filesize = total_size;
740 }
741
742 ret = 0;
743
744 out:
745 ssh_state_free(&s);
746 if (uri_options != NULL) {
747 QDECREF(uri_options);
748 }
749 return ret;
750}
751
752static void ssh_close(BlockDriverState *bs)
753{
754 BDRVSSHState *s = bs->opaque;
755
756 ssh_state_free(s);
757}
758
759static int ssh_has_zero_init(BlockDriverState *bs)
760{
761 BDRVSSHState *s = bs->opaque;
762
763 int has_zero_init = 0;
764
765 if (s->attrs.flags & LIBSSH2_SFTP_ATTR_PERMISSIONS) {
766 if (s->attrs.permissions & LIBSSH2_SFTP_S_IFREG) {
767 has_zero_init = 1;
768 }
769 }
770
771 return has_zero_init;
772}
773
774static void restart_coroutine(void *opaque)
775{
776 Coroutine *co = opaque;
777
778 DPRINTF("co=%p", co);
779
780 qemu_coroutine_enter(co, NULL);
781}
782
783static coroutine_fn void set_fd_handler(BDRVSSHState *s, BlockDriverState *bs)
784{
785 int r;
786 IOHandler *rd_handler = NULL, *wr_handler = NULL;
787 Coroutine *co = qemu_coroutine_self();
788
789 r = libssh2_session_block_directions(s->session);
790
791 if (r & LIBSSH2_SESSION_BLOCK_INBOUND) {
792 rd_handler = restart_coroutine;
793 }
794 if (r & LIBSSH2_SESSION_BLOCK_OUTBOUND) {
795 wr_handler = restart_coroutine;
796 }
797
798 DPRINTF("s->sock=%d rd_handler=%p wr_handler=%p", s->sock,
799 rd_handler, wr_handler);
800
801 aio_set_fd_handler(bdrv_get_aio_context(bs), s->sock,
802 false, rd_handler, wr_handler, co);
803}
804
805static coroutine_fn void clear_fd_handler(BDRVSSHState *s,
806 BlockDriverState *bs)
807{
808 DPRINTF("s->sock=%d", s->sock);
809 aio_set_fd_handler(bdrv_get_aio_context(bs), s->sock,
810 false, NULL, NULL, NULL);
811}
812
813
814
815
816
817static coroutine_fn void co_yield(BDRVSSHState *s, BlockDriverState *bs)
818{
819 set_fd_handler(s, bs);
820 qemu_coroutine_yield();
821 clear_fd_handler(s, bs);
822}
823
824
825
826
827
828
829
830
831
832
833
834#define SSH_SEEK_WRITE 0
835#define SSH_SEEK_READ 1
836#define SSH_SEEK_FORCE 2
837
838static void ssh_seek(BDRVSSHState *s, int64_t offset, int flags)
839{
840 bool op_read = (flags & SSH_SEEK_READ) != 0;
841 bool force = (flags & SSH_SEEK_FORCE) != 0;
842
843 if (force || op_read != s->offset_op_read || offset != s->offset) {
844 DPRINTF("seeking to offset=%" PRIi64, offset);
845 libssh2_sftp_seek64(s->sftp_handle, offset);
846 s->offset = offset;
847 s->offset_op_read = op_read;
848 }
849}
850
851static coroutine_fn int ssh_read(BDRVSSHState *s, BlockDriverState *bs,
852 int64_t offset, size_t size,
853 QEMUIOVector *qiov)
854{
855 ssize_t r;
856 size_t got;
857 char *buf, *end_of_vec;
858 struct iovec *i;
859
860 DPRINTF("offset=%" PRIi64 " size=%zu", offset, size);
861
862 ssh_seek(s, offset, SSH_SEEK_READ);
863
864
865
866
867
868 i = &qiov->iov[0];
869 buf = i->iov_base;
870 end_of_vec = i->iov_base + i->iov_len;
871
872
873
874
875
876
877 for (got = 0; got < size; ) {
878 again:
879 DPRINTF("sftp_read buf=%p size=%zu", buf, end_of_vec - buf);
880 r = libssh2_sftp_read(s->sftp_handle, buf, end_of_vec - buf);
881 DPRINTF("sftp_read returned %zd", r);
882
883 if (r == LIBSSH2_ERROR_EAGAIN || r == LIBSSH2_ERROR_TIMEOUT) {
884 co_yield(s, bs);
885 goto again;
886 }
887 if (r < 0) {
888 sftp_error_report(s, "read failed");
889 s->offset = -1;
890 return -EIO;
891 }
892 if (r == 0) {
893
894 qemu_iovec_memset(qiov, got, 0, size - got);
895 return 0;
896 }
897
898 got += r;
899 buf += r;
900 s->offset += r;
901 if (buf >= end_of_vec && got < size) {
902 i++;
903 buf = i->iov_base;
904 end_of_vec = i->iov_base + i->iov_len;
905 }
906 }
907
908 return 0;
909}
910
911static coroutine_fn int ssh_co_readv(BlockDriverState *bs,
912 int64_t sector_num,
913 int nb_sectors, QEMUIOVector *qiov)
914{
915 BDRVSSHState *s = bs->opaque;
916 int ret;
917
918 qemu_co_mutex_lock(&s->lock);
919 ret = ssh_read(s, bs, sector_num * BDRV_SECTOR_SIZE,
920 nb_sectors * BDRV_SECTOR_SIZE, qiov);
921 qemu_co_mutex_unlock(&s->lock);
922
923 return ret;
924}
925
926static int ssh_write(BDRVSSHState *s, BlockDriverState *bs,
927 int64_t offset, size_t size,
928 QEMUIOVector *qiov)
929{
930 ssize_t r;
931 size_t written;
932 char *buf, *end_of_vec;
933 struct iovec *i;
934
935 DPRINTF("offset=%" PRIi64 " size=%zu", offset, size);
936
937 ssh_seek(s, offset, SSH_SEEK_WRITE);
938
939
940
941
942
943 i = &qiov->iov[0];
944 buf = i->iov_base;
945 end_of_vec = i->iov_base + i->iov_len;
946
947 for (written = 0; written < size; ) {
948 again:
949 DPRINTF("sftp_write buf=%p size=%zu", buf, end_of_vec - buf);
950 r = libssh2_sftp_write(s->sftp_handle, buf, end_of_vec - buf);
951 DPRINTF("sftp_write returned %zd", r);
952
953 if (r == LIBSSH2_ERROR_EAGAIN || r == LIBSSH2_ERROR_TIMEOUT) {
954 co_yield(s, bs);
955 goto again;
956 }
957 if (r < 0) {
958 sftp_error_report(s, "write failed");
959 s->offset = -1;
960 return -EIO;
961 }
962
963
964
965
966
967
968
969
970
971 if (r == 0) {
972 ssh_seek(s, offset + written, SSH_SEEK_WRITE|SSH_SEEK_FORCE);
973 co_yield(s, bs);
974 goto again;
975 }
976
977 written += r;
978 buf += r;
979 s->offset += r;
980 if (buf >= end_of_vec && written < size) {
981 i++;
982 buf = i->iov_base;
983 end_of_vec = i->iov_base + i->iov_len;
984 }
985
986 if (offset + written > s->attrs.filesize)
987 s->attrs.filesize = offset + written;
988 }
989
990 return 0;
991}
992
993static coroutine_fn int ssh_co_writev(BlockDriverState *bs,
994 int64_t sector_num,
995 int nb_sectors, QEMUIOVector *qiov)
996{
997 BDRVSSHState *s = bs->opaque;
998 int ret;
999
1000 qemu_co_mutex_lock(&s->lock);
1001 ret = ssh_write(s, bs, sector_num * BDRV_SECTOR_SIZE,
1002 nb_sectors * BDRV_SECTOR_SIZE, qiov);
1003 qemu_co_mutex_unlock(&s->lock);
1004
1005 return ret;
1006}
1007
1008static void unsafe_flush_warning(BDRVSSHState *s, const char *what)
1009{
1010 if (!s->unsafe_flush_warning) {
1011 error_report("warning: ssh server %s does not support fsync",
1012 s->hostport);
1013 if (what) {
1014 error_report("to support fsync, you need %s", what);
1015 }
1016 s->unsafe_flush_warning = true;
1017 }
1018}
1019
1020#ifdef HAS_LIBSSH2_SFTP_FSYNC
1021
1022static coroutine_fn int ssh_flush(BDRVSSHState *s, BlockDriverState *bs)
1023{
1024 int r;
1025
1026 DPRINTF("fsync");
1027 again:
1028 r = libssh2_sftp_fsync(s->sftp_handle);
1029 if (r == LIBSSH2_ERROR_EAGAIN || r == LIBSSH2_ERROR_TIMEOUT) {
1030 co_yield(s, bs);
1031 goto again;
1032 }
1033 if (r == LIBSSH2_ERROR_SFTP_PROTOCOL &&
1034 libssh2_sftp_last_error(s->sftp) == LIBSSH2_FX_OP_UNSUPPORTED) {
1035 unsafe_flush_warning(s, "OpenSSH >= 6.3");
1036 return 0;
1037 }
1038 if (r < 0) {
1039 sftp_error_report(s, "fsync failed");
1040 return -EIO;
1041 }
1042
1043 return 0;
1044}
1045
1046static coroutine_fn int ssh_co_flush(BlockDriverState *bs)
1047{
1048 BDRVSSHState *s = bs->opaque;
1049 int ret;
1050
1051 qemu_co_mutex_lock(&s->lock);
1052 ret = ssh_flush(s, bs);
1053 qemu_co_mutex_unlock(&s->lock);
1054
1055 return ret;
1056}
1057
1058#else
1059
1060static coroutine_fn int ssh_co_flush(BlockDriverState *bs)
1061{
1062 BDRVSSHState *s = bs->opaque;
1063
1064 unsafe_flush_warning(s, "libssh2 >= 1.4.4");
1065 return 0;
1066}
1067
1068#endif
1069
1070static int64_t ssh_getlength(BlockDriverState *bs)
1071{
1072 BDRVSSHState *s = bs->opaque;
1073 int64_t length;
1074
1075
1076 length = (int64_t) s->attrs.filesize;
1077 DPRINTF("length=%" PRIi64, length);
1078
1079 return length;
1080}
1081
1082static BlockDriver bdrv_ssh = {
1083 .format_name = "ssh",
1084 .protocol_name = "ssh",
1085 .instance_size = sizeof(BDRVSSHState),
1086 .bdrv_parse_filename = ssh_parse_filename,
1087 .bdrv_file_open = ssh_file_open,
1088 .bdrv_create = ssh_create,
1089 .bdrv_close = ssh_close,
1090 .bdrv_has_zero_init = ssh_has_zero_init,
1091 .bdrv_co_readv = ssh_co_readv,
1092 .bdrv_co_writev = ssh_co_writev,
1093 .bdrv_getlength = ssh_getlength,
1094 .bdrv_co_flush_to_disk = ssh_co_flush,
1095 .create_opts = &ssh_create_opts,
1096};
1097
1098static void bdrv_ssh_init(void)
1099{
1100 int r;
1101
1102 r = libssh2_init(0);
1103 if (r != 0) {
1104 fprintf(stderr, "libssh2 initialization failed, %d\n", r);
1105 exit(EXIT_FAILURE);
1106 }
1107
1108 bdrv_register(&bdrv_ssh);
1109}
1110
1111block_init(bdrv_ssh_init);
1112