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25#include "qemu/osdep.h"
26
27#include <libssh/libssh.h>
28#include <libssh/sftp.h>
29
30#include "block/block_int.h"
31#include "block/qdict.h"
32#include "qapi/error.h"
33#include "qemu/error-report.h"
34#include "qemu/module.h"
35#include "qemu/option.h"
36#include "qemu/ctype.h"
37#include "qemu/cutils.h"
38#include "qemu/sockets.h"
39#include "qemu/uri.h"
40#include "qapi/qapi-visit-sockets.h"
41#include "qapi/qapi-visit-block-core.h"
42#include "qapi/qmp/qdict.h"
43#include "qapi/qmp/qstring.h"
44#include "qapi/qobject-input-visitor.h"
45#include "qapi/qobject-output-visitor.h"
46#include "trace.h"
47
48
49
50
51
52
53#define TRACE_LIBSSH 0
54
55typedef struct BDRVSSHState {
56
57 CoMutex lock;
58
59
60 int sock;
61 ssh_session session;
62 sftp_session sftp;
63 sftp_file sftp_handle;
64
65
66
67
68
69 sftp_attributes attrs;
70
71 InetSocketAddress *inet;
72
73
74 bool unsafe_flush_warning;
75
76
77
78
79
80
81
82 char *user;
83} BDRVSSHState;
84
85static void ssh_state_init(BDRVSSHState *s)
86{
87 memset(s, 0, sizeof *s);
88 s->sock = -1;
89 qemu_co_mutex_init(&s->lock);
90}
91
92static void ssh_state_free(BDRVSSHState *s)
93{
94 g_free(s->user);
95
96 if (s->attrs) {
97 sftp_attributes_free(s->attrs);
98 }
99 if (s->sftp_handle) {
100 sftp_close(s->sftp_handle);
101 }
102 if (s->sftp) {
103 sftp_free(s->sftp);
104 }
105 if (s->session) {
106 ssh_disconnect(s->session);
107 ssh_free(s->session);
108 }
109}
110
111static void GCC_FMT_ATTR(3, 4)
112session_error_setg(Error **errp, BDRVSSHState *s, const char *fs, ...)
113{
114 va_list args;
115 char *msg;
116
117 va_start(args, fs);
118 msg = g_strdup_vprintf(fs, args);
119 va_end(args);
120
121 if (s->session) {
122 const char *ssh_err;
123 int ssh_err_code;
124
125
126 ssh_err = ssh_get_error(s->session);
127 ssh_err_code = ssh_get_error_code(s->session);
128 error_setg(errp, "%s: %s (libssh error code: %d)",
129 msg, ssh_err, ssh_err_code);
130 } else {
131 error_setg(errp, "%s", msg);
132 }
133 g_free(msg);
134}
135
136static void GCC_FMT_ATTR(3, 4)
137sftp_error_setg(Error **errp, BDRVSSHState *s, const char *fs, ...)
138{
139 va_list args;
140 char *msg;
141
142 va_start(args, fs);
143 msg = g_strdup_vprintf(fs, args);
144 va_end(args);
145
146 if (s->sftp) {
147 const char *ssh_err;
148 int ssh_err_code;
149 int sftp_err_code;
150
151
152 ssh_err = ssh_get_error(s->session);
153 ssh_err_code = ssh_get_error_code(s->session);
154
155 sftp_err_code = sftp_get_error(s->sftp);
156
157 error_setg(errp,
158 "%s: %s (libssh error code: %d, sftp error code: %d)",
159 msg, ssh_err, ssh_err_code, sftp_err_code);
160 } else {
161 error_setg(errp, "%s", msg);
162 }
163 g_free(msg);
164}
165
166static void sftp_error_trace(BDRVSSHState *s, const char *op)
167{
168 const char *ssh_err;
169 int ssh_err_code;
170 int sftp_err_code;
171
172
173 ssh_err = ssh_get_error(s->session);
174 ssh_err_code = ssh_get_error_code(s->session);
175
176 sftp_err_code = sftp_get_error(s->sftp);
177
178 trace_sftp_error(op, ssh_err, ssh_err_code, sftp_err_code);
179}
180
181static int parse_uri(const char *filename, QDict *options, Error **errp)
182{
183 URI *uri = NULL;
184 QueryParams *qp;
185 char *port_str;
186 int i;
187
188 uri = uri_parse(filename);
189 if (!uri) {
190 return -EINVAL;
191 }
192
193 if (g_strcmp0(uri->scheme, "ssh") != 0) {
194 error_setg(errp, "URI scheme must be 'ssh'");
195 goto err;
196 }
197
198 if (!uri->server || strcmp(uri->server, "") == 0) {
199 error_setg(errp, "missing hostname in URI");
200 goto err;
201 }
202
203 if (!uri->path || strcmp(uri->path, "") == 0) {
204 error_setg(errp, "missing remote path in URI");
205 goto err;
206 }
207
208 qp = query_params_parse(uri->query);
209 if (!qp) {
210 error_setg(errp, "could not parse query parameters");
211 goto err;
212 }
213
214 if(uri->user && strcmp(uri->user, "") != 0) {
215 qdict_put_str(options, "user", uri->user);
216 }
217
218 qdict_put_str(options, "server.host", uri->server);
219
220 port_str = g_strdup_printf("%d", uri->port ?: 22);
221 qdict_put_str(options, "server.port", port_str);
222 g_free(port_str);
223
224 qdict_put_str(options, "path", uri->path);
225
226
227
228
229 for (i = 0; i < qp->n; ++i) {
230 if (strcmp(qp->p[i].name, "host_key_check") == 0) {
231 qdict_put_str(options, "host_key_check", qp->p[i].value);
232 }
233 }
234
235 query_params_free(qp);
236 uri_free(uri);
237 return 0;
238
239 err:
240 if (uri) {
241 uri_free(uri);
242 }
243 return -EINVAL;
244}
245
246static bool ssh_has_filename_options_conflict(QDict *options, Error **errp)
247{
248 const QDictEntry *qe;
249
250 for (qe = qdict_first(options); qe; qe = qdict_next(options, qe)) {
251 if (!strcmp(qe->key, "host") ||
252 !strcmp(qe->key, "port") ||
253 !strcmp(qe->key, "path") ||
254 !strcmp(qe->key, "user") ||
255 !strcmp(qe->key, "host_key_check") ||
256 strstart(qe->key, "server.", NULL))
257 {
258 error_setg(errp, "Option '%s' cannot be used with a file name",
259 qe->key);
260 return true;
261 }
262 }
263
264 return false;
265}
266
267static void ssh_parse_filename(const char *filename, QDict *options,
268 Error **errp)
269{
270 if (ssh_has_filename_options_conflict(options, errp)) {
271 return;
272 }
273
274 parse_uri(filename, options, errp);
275}
276
277static int check_host_key_knownhosts(BDRVSSHState *s, Error **errp)
278{
279 int ret;
280#ifdef HAVE_LIBSSH_0_8
281 enum ssh_known_hosts_e state;
282 int r;
283 ssh_key pubkey;
284 enum ssh_keytypes_e pubkey_type;
285 unsigned char *server_hash = NULL;
286 size_t server_hash_len;
287 char *fingerprint = NULL;
288
289 state = ssh_session_is_known_server(s->session);
290 trace_ssh_server_status(state);
291
292 switch (state) {
293 case SSH_KNOWN_HOSTS_OK:
294
295 trace_ssh_check_host_key_knownhosts();
296 break;
297 case SSH_KNOWN_HOSTS_CHANGED:
298 ret = -EINVAL;
299 r = ssh_get_server_publickey(s->session, &pubkey);
300 if (r == 0) {
301 r = ssh_get_publickey_hash(pubkey, SSH_PUBLICKEY_HASH_SHA256,
302 &server_hash, &server_hash_len);
303 pubkey_type = ssh_key_type(pubkey);
304 ssh_key_free(pubkey);
305 }
306 if (r == 0) {
307 fingerprint = ssh_get_fingerprint_hash(SSH_PUBLICKEY_HASH_SHA256,
308 server_hash,
309 server_hash_len);
310 ssh_clean_pubkey_hash(&server_hash);
311 }
312 if (fingerprint) {
313 error_setg(errp,
314 "host key (%s key with fingerprint %s) does not match "
315 "the one in known_hosts; this may be a possible attack",
316 ssh_key_type_to_char(pubkey_type), fingerprint);
317 ssh_string_free_char(fingerprint);
318 } else {
319 error_setg(errp,
320 "host key does not match the one in known_hosts; this "
321 "may be a possible attack");
322 }
323 goto out;
324 case SSH_KNOWN_HOSTS_OTHER:
325 ret = -EINVAL;
326 error_setg(errp,
327 "host key for this server not found, another type exists");
328 goto out;
329 case SSH_KNOWN_HOSTS_UNKNOWN:
330 ret = -EINVAL;
331 error_setg(errp, "no host key was found in known_hosts");
332 goto out;
333 case SSH_KNOWN_HOSTS_NOT_FOUND:
334 ret = -ENOENT;
335 error_setg(errp, "known_hosts file not found");
336 goto out;
337 case SSH_KNOWN_HOSTS_ERROR:
338 ret = -EINVAL;
339 error_setg(errp, "error while checking the host");
340 goto out;
341 default:
342 ret = -EINVAL;
343 error_setg(errp, "error while checking for known server (%d)", state);
344 goto out;
345 }
346#else
347 int state;
348
349 state = ssh_is_server_known(s->session);
350 trace_ssh_server_status(state);
351
352 switch (state) {
353 case SSH_SERVER_KNOWN_OK:
354
355 trace_ssh_check_host_key_knownhosts();
356 break;
357 case SSH_SERVER_KNOWN_CHANGED:
358 ret = -EINVAL;
359 error_setg(errp,
360 "host key does not match the one in known_hosts; this "
361 "may be a possible attack");
362 goto out;
363 case SSH_SERVER_FOUND_OTHER:
364 ret = -EINVAL;
365 error_setg(errp,
366 "host key for this server not found, another type exists");
367 goto out;
368 case SSH_SERVER_FILE_NOT_FOUND:
369 ret = -ENOENT;
370 error_setg(errp, "known_hosts file not found");
371 goto out;
372 case SSH_SERVER_NOT_KNOWN:
373 ret = -EINVAL;
374 error_setg(errp, "no host key was found in known_hosts");
375 goto out;
376 case SSH_SERVER_ERROR:
377 ret = -EINVAL;
378 error_setg(errp, "server error");
379 goto out;
380 default:
381 ret = -EINVAL;
382 error_setg(errp, "error while checking for known server (%d)", state);
383 goto out;
384 }
385#endif
386
387
388 ret = 0;
389
390 out:
391 return ret;
392}
393
394static unsigned hex2decimal(char ch)
395{
396 if (ch >= '0' && ch <= '9') {
397 return (ch - '0');
398 } else if (ch >= 'a' && ch <= 'f') {
399 return 10 + (ch - 'a');
400 } else if (ch >= 'A' && ch <= 'F') {
401 return 10 + (ch - 'A');
402 }
403
404 return -1;
405}
406
407
408
409
410static int compare_fingerprint(const unsigned char *fingerprint, size_t len,
411 const char *host_key_check)
412{
413 unsigned c;
414
415 while (len > 0) {
416 while (*host_key_check == ':')
417 host_key_check++;
418 if (!qemu_isxdigit(host_key_check[0]) ||
419 !qemu_isxdigit(host_key_check[1]))
420 return 1;
421 c = hex2decimal(host_key_check[0]) * 16 +
422 hex2decimal(host_key_check[1]);
423 if (c - *fingerprint != 0)
424 return c - *fingerprint;
425 fingerprint++;
426 len--;
427 host_key_check += 2;
428 }
429 return *host_key_check - '\0';
430}
431
432static int
433check_host_key_hash(BDRVSSHState *s, const char *hash,
434 enum ssh_publickey_hash_type type, Error **errp)
435{
436 int r;
437 ssh_key pubkey;
438 unsigned char *server_hash;
439 size_t server_hash_len;
440
441#ifdef HAVE_LIBSSH_0_8
442 r = ssh_get_server_publickey(s->session, &pubkey);
443#else
444 r = ssh_get_publickey(s->session, &pubkey);
445#endif
446 if (r != SSH_OK) {
447 session_error_setg(errp, s, "failed to read remote host key");
448 return -EINVAL;
449 }
450
451 r = ssh_get_publickey_hash(pubkey, type, &server_hash, &server_hash_len);
452 ssh_key_free(pubkey);
453 if (r != 0) {
454 session_error_setg(errp, s,
455 "failed reading the hash of the server SSH key");
456 return -EINVAL;
457 }
458
459 r = compare_fingerprint(server_hash, server_hash_len, hash);
460 ssh_clean_pubkey_hash(&server_hash);
461 if (r != 0) {
462 error_setg(errp, "remote host key does not match host_key_check '%s'",
463 hash);
464 return -EPERM;
465 }
466
467 return 0;
468}
469
470static int check_host_key(BDRVSSHState *s, SshHostKeyCheck *hkc, Error **errp)
471{
472 SshHostKeyCheckMode mode;
473
474 if (hkc) {
475 mode = hkc->mode;
476 } else {
477 mode = SSH_HOST_KEY_CHECK_MODE_KNOWN_HOSTS;
478 }
479
480 switch (mode) {
481 case SSH_HOST_KEY_CHECK_MODE_NONE:
482 return 0;
483 case SSH_HOST_KEY_CHECK_MODE_HASH:
484 if (hkc->u.hash.type == SSH_HOST_KEY_CHECK_HASH_TYPE_MD5) {
485 return check_host_key_hash(s, hkc->u.hash.hash,
486 SSH_PUBLICKEY_HASH_MD5, errp);
487 } else if (hkc->u.hash.type == SSH_HOST_KEY_CHECK_HASH_TYPE_SHA1) {
488 return check_host_key_hash(s, hkc->u.hash.hash,
489 SSH_PUBLICKEY_HASH_SHA1, errp);
490 }
491 g_assert_not_reached();
492 break;
493 case SSH_HOST_KEY_CHECK_MODE_KNOWN_HOSTS:
494 return check_host_key_knownhosts(s, errp);
495 default:
496 g_assert_not_reached();
497 }
498
499 return -EINVAL;
500}
501
502static int authenticate(BDRVSSHState *s, Error **errp)
503{
504 int r, ret;
505 int method;
506
507
508 r = ssh_userauth_none(s->session, NULL);
509 if (r == SSH_AUTH_ERROR) {
510 ret = -EPERM;
511 session_error_setg(errp, s, "failed to authenticate using none "
512 "authentication");
513 goto out;
514 } else if (r == SSH_AUTH_SUCCESS) {
515
516 ret = 0;
517 goto out;
518 }
519
520 method = ssh_userauth_list(s->session, NULL);
521 trace_ssh_auth_methods(method);
522
523
524
525
526
527 if (method & SSH_AUTH_METHOD_PUBLICKEY) {
528 r = ssh_userauth_publickey_auto(s->session, NULL, NULL);
529 if (r == SSH_AUTH_ERROR) {
530 ret = -EINVAL;
531 session_error_setg(errp, s, "failed to authenticate using "
532 "publickey authentication");
533 goto out;
534 } else if (r == SSH_AUTH_SUCCESS) {
535
536 ret = 0;
537 goto out;
538 }
539 }
540
541 ret = -EPERM;
542 error_setg(errp, "failed to authenticate using publickey authentication "
543 "and the identities held by your ssh-agent");
544
545 out:
546 return ret;
547}
548
549static QemuOptsList ssh_runtime_opts = {
550 .name = "ssh",
551 .head = QTAILQ_HEAD_INITIALIZER(ssh_runtime_opts.head),
552 .desc = {
553 {
554 .name = "host",
555 .type = QEMU_OPT_STRING,
556 .help = "Host to connect to",
557 },
558 {
559 .name = "port",
560 .type = QEMU_OPT_NUMBER,
561 .help = "Port to connect to",
562 },
563 {
564 .name = "host_key_check",
565 .type = QEMU_OPT_STRING,
566 .help = "Defines how and what to check the host key against",
567 },
568 { }
569 },
570};
571
572static bool ssh_process_legacy_options(QDict *output_opts,
573 QemuOpts *legacy_opts,
574 Error **errp)
575{
576 const char *host = qemu_opt_get(legacy_opts, "host");
577 const char *port = qemu_opt_get(legacy_opts, "port");
578 const char *host_key_check = qemu_opt_get(legacy_opts, "host_key_check");
579
580 if (!host && port) {
581 error_setg(errp, "port may not be used without host");
582 return false;
583 }
584
585 if (host) {
586 qdict_put_str(output_opts, "server.host", host);
587 qdict_put_str(output_opts, "server.port", port ?: stringify(22));
588 }
589
590 if (host_key_check) {
591 if (strcmp(host_key_check, "no") == 0) {
592 qdict_put_str(output_opts, "host-key-check.mode", "none");
593 } else if (strncmp(host_key_check, "md5:", 4) == 0) {
594 qdict_put_str(output_opts, "host-key-check.mode", "hash");
595 qdict_put_str(output_opts, "host-key-check.type", "md5");
596 qdict_put_str(output_opts, "host-key-check.hash",
597 &host_key_check[4]);
598 } else if (strncmp(host_key_check, "sha1:", 5) == 0) {
599 qdict_put_str(output_opts, "host-key-check.mode", "hash");
600 qdict_put_str(output_opts, "host-key-check.type", "sha1");
601 qdict_put_str(output_opts, "host-key-check.hash",
602 &host_key_check[5]);
603 } else if (strcmp(host_key_check, "yes") == 0) {
604 qdict_put_str(output_opts, "host-key-check.mode", "known_hosts");
605 } else {
606 error_setg(errp, "unknown host_key_check setting (%s)",
607 host_key_check);
608 return false;
609 }
610 }
611
612 return true;
613}
614
615static BlockdevOptionsSsh *ssh_parse_options(QDict *options, Error **errp)
616{
617 BlockdevOptionsSsh *result = NULL;
618 QemuOpts *opts = NULL;
619 Error *local_err = NULL;
620 const QDictEntry *e;
621 Visitor *v;
622
623
624 opts = qemu_opts_create(&ssh_runtime_opts, NULL, 0, &error_abort);
625 qemu_opts_absorb_qdict(opts, options, &local_err);
626 if (local_err) {
627 error_propagate(errp, local_err);
628 goto fail;
629 }
630
631 if (!ssh_process_legacy_options(options, opts, errp)) {
632 goto fail;
633 }
634
635
636 v = qobject_input_visitor_new_flat_confused(options, errp);
637 if (!v) {
638 goto fail;
639 }
640
641 visit_type_BlockdevOptionsSsh(v, NULL, &result, &local_err);
642 visit_free(v);
643
644 if (local_err) {
645 error_propagate(errp, local_err);
646 goto fail;
647 }
648
649
650
651 while ((e = qdict_first(options))) {
652 qdict_del(options, e->key);
653 }
654
655fail:
656 qemu_opts_del(opts);
657 return result;
658}
659
660static int connect_to_ssh(BDRVSSHState *s, BlockdevOptionsSsh *opts,
661 int ssh_flags, int creat_mode, Error **errp)
662{
663 int r, ret;
664 unsigned int port = 0;
665 int new_sock = -1;
666
667 if (opts->has_user) {
668 s->user = g_strdup(opts->user);
669 } else {
670 s->user = g_strdup(g_get_user_name());
671 if (!s->user) {
672 error_setg_errno(errp, errno, "Can't get user name");
673 ret = -errno;
674 goto err;
675 }
676 }
677
678
679 s->inet = opts->server;
680 opts->server = NULL;
681
682 if (qemu_strtoui(s->inet->port, NULL, 10, &port) < 0) {
683 error_setg(errp, "Use only numeric port value");
684 ret = -EINVAL;
685 goto err;
686 }
687
688
689 new_sock = inet_connect_saddr(s->inet, errp);
690 if (new_sock < 0) {
691 ret = -EIO;
692 goto err;
693 }
694
695
696
697
698
699 r = socket_set_nodelay(new_sock);
700 if (r < 0) {
701 warn_report("can't set TCP_NODELAY for the ssh server %s: %s",
702 s->inet->host, strerror(errno));
703 }
704
705
706 s->session = ssh_new();
707 if (!s->session) {
708 ret = -EINVAL;
709 session_error_setg(errp, s, "failed to initialize libssh session");
710 goto err;
711 }
712
713
714
715
716
717 ssh_set_blocking(s->session, 1);
718
719 r = ssh_options_set(s->session, SSH_OPTIONS_USER, s->user);
720 if (r < 0) {
721 ret = -EINVAL;
722 session_error_setg(errp, s,
723 "failed to set the user in the libssh session");
724 goto err;
725 }
726
727 r = ssh_options_set(s->session, SSH_OPTIONS_HOST, s->inet->host);
728 if (r < 0) {
729 ret = -EINVAL;
730 session_error_setg(errp, s,
731 "failed to set the host in the libssh session");
732 goto err;
733 }
734
735 if (port > 0) {
736 r = ssh_options_set(s->session, SSH_OPTIONS_PORT, &port);
737 if (r < 0) {
738 ret = -EINVAL;
739 session_error_setg(errp, s,
740 "failed to set the port in the libssh session");
741 goto err;
742 }
743 }
744
745 r = ssh_options_set(s->session, SSH_OPTIONS_COMPRESSION, "none");
746 if (r < 0) {
747 ret = -EINVAL;
748 session_error_setg(errp, s,
749 "failed to disable the compression in the libssh "
750 "session");
751 goto err;
752 }
753
754
755 r = ssh_options_parse_config(s->session, NULL);
756 if (r < 0) {
757 ret = -EINVAL;
758 session_error_setg(errp, s, "failed to parse ~/.ssh/config");
759 goto err;
760 }
761
762 r = ssh_options_set(s->session, SSH_OPTIONS_FD, &new_sock);
763 if (r < 0) {
764 ret = -EINVAL;
765 session_error_setg(errp, s,
766 "failed to set the socket in the libssh session");
767 goto err;
768 }
769
770 s->sock = new_sock;
771 new_sock = -1;
772
773
774 r = ssh_connect(s->session);
775 if (r != SSH_OK) {
776 ret = -EINVAL;
777 session_error_setg(errp, s, "failed to establish SSH session");
778 goto err;
779 }
780
781
782 ret = check_host_key(s, opts->host_key_check, errp);
783 if (ret < 0) {
784 goto err;
785 }
786
787
788 ret = authenticate(s, errp);
789 if (ret < 0) {
790 goto err;
791 }
792
793
794 s->sftp = sftp_new(s->session);
795 if (!s->sftp) {
796 session_error_setg(errp, s, "failed to create sftp handle");
797 ret = -EINVAL;
798 goto err;
799 }
800
801 r = sftp_init(s->sftp);
802 if (r < 0) {
803 sftp_error_setg(errp, s, "failed to initialize sftp handle");
804 ret = -EINVAL;
805 goto err;
806 }
807
808
809 trace_ssh_connect_to_ssh(opts->path, ssh_flags, creat_mode);
810 s->sftp_handle = sftp_open(s->sftp, opts->path, ssh_flags, creat_mode);
811 if (!s->sftp_handle) {
812 sftp_error_setg(errp, s, "failed to open remote file '%s'",
813 opts->path);
814 ret = -EINVAL;
815 goto err;
816 }
817
818
819 sftp_file_set_blocking(s->sftp_handle);
820
821 s->attrs = sftp_fstat(s->sftp_handle);
822 if (!s->attrs) {
823 sftp_error_setg(errp, s, "failed to read file attributes");
824 return -EINVAL;
825 }
826
827 return 0;
828
829 err:
830 if (s->attrs) {
831 sftp_attributes_free(s->attrs);
832 }
833 s->attrs = NULL;
834 if (s->sftp_handle) {
835 sftp_close(s->sftp_handle);
836 }
837 s->sftp_handle = NULL;
838 if (s->sftp) {
839 sftp_free(s->sftp);
840 }
841 s->sftp = NULL;
842 if (s->session) {
843 ssh_disconnect(s->session);
844 ssh_free(s->session);
845 }
846 s->session = NULL;
847 s->sock = -1;
848 if (new_sock >= 0) {
849 close(new_sock);
850 }
851
852 return ret;
853}
854
855static int ssh_file_open(BlockDriverState *bs, QDict *options, int bdrv_flags,
856 Error **errp)
857{
858 BDRVSSHState *s = bs->opaque;
859 BlockdevOptionsSsh *opts;
860 int ret;
861 int ssh_flags;
862
863 ssh_state_init(s);
864
865 ssh_flags = 0;
866 if (bdrv_flags & BDRV_O_RDWR) {
867 ssh_flags |= O_RDWR;
868 } else {
869 ssh_flags |= O_RDONLY;
870 }
871
872 opts = ssh_parse_options(options, errp);
873 if (opts == NULL) {
874 return -EINVAL;
875 }
876
877
878 ret = connect_to_ssh(s, opts, ssh_flags, 0, errp);
879 if (ret < 0) {
880 goto err;
881 }
882
883
884 ssh_set_blocking(s->session, 0);
885
886 qapi_free_BlockdevOptionsSsh(opts);
887
888 return 0;
889
890 err:
891 qapi_free_BlockdevOptionsSsh(opts);
892
893 return ret;
894}
895
896
897static int ssh_grow_file(BDRVSSHState *s, int64_t offset, Error **errp)
898{
899 ssize_t ret;
900 char c[1] = { '\0' };
901 int was_blocking = ssh_is_blocking(s->session);
902
903
904
905 assert(offset > 0 && offset > s->attrs->size);
906
907 ssh_set_blocking(s->session, 1);
908
909 sftp_seek64(s->sftp_handle, offset - 1);
910 ret = sftp_write(s->sftp_handle, c, 1);
911
912 ssh_set_blocking(s->session, was_blocking);
913
914 if (ret < 0) {
915 sftp_error_setg(errp, s, "Failed to grow file");
916 return -EIO;
917 }
918
919 s->attrs->size = offset;
920 return 0;
921}
922
923static QemuOptsList ssh_create_opts = {
924 .name = "ssh-create-opts",
925 .head = QTAILQ_HEAD_INITIALIZER(ssh_create_opts.head),
926 .desc = {
927 {
928 .name = BLOCK_OPT_SIZE,
929 .type = QEMU_OPT_SIZE,
930 .help = "Virtual disk size"
931 },
932 { }
933 }
934};
935
936static int ssh_co_create(BlockdevCreateOptions *options, Error **errp)
937{
938 BlockdevCreateOptionsSsh *opts = &options->u.ssh;
939 BDRVSSHState s;
940 int ret;
941
942 assert(options->driver == BLOCKDEV_DRIVER_SSH);
943
944 ssh_state_init(&s);
945
946 ret = connect_to_ssh(&s, opts->location,
947 O_RDWR | O_CREAT | O_TRUNC,
948 0644, errp);
949 if (ret < 0) {
950 goto fail;
951 }
952
953 if (opts->size > 0) {
954 ret = ssh_grow_file(&s, opts->size, errp);
955 if (ret < 0) {
956 goto fail;
957 }
958 }
959
960 ret = 0;
961fail:
962 ssh_state_free(&s);
963 return ret;
964}
965
966static int coroutine_fn ssh_co_create_opts(BlockDriver *drv,
967 const char *filename,
968 QemuOpts *opts,
969 Error **errp)
970{
971 BlockdevCreateOptions *create_options;
972 BlockdevCreateOptionsSsh *ssh_opts;
973 int ret;
974 QDict *uri_options = NULL;
975
976 create_options = g_new0(BlockdevCreateOptions, 1);
977 create_options->driver = BLOCKDEV_DRIVER_SSH;
978 ssh_opts = &create_options->u.ssh;
979
980
981 ssh_opts->size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
982 BDRV_SECTOR_SIZE);
983 trace_ssh_co_create_opts(ssh_opts->size);
984
985 uri_options = qdict_new();
986 ret = parse_uri(filename, uri_options, errp);
987 if (ret < 0) {
988 goto out;
989 }
990
991 ssh_opts->location = ssh_parse_options(uri_options, errp);
992 if (ssh_opts->location == NULL) {
993 ret = -EINVAL;
994 goto out;
995 }
996
997 ret = ssh_co_create(create_options, errp);
998
999 out:
1000 qobject_unref(uri_options);
1001 qapi_free_BlockdevCreateOptions(create_options);
1002 return ret;
1003}
1004
1005static void ssh_close(BlockDriverState *bs)
1006{
1007 BDRVSSHState *s = bs->opaque;
1008
1009 ssh_state_free(s);
1010}
1011
1012static int ssh_has_zero_init(BlockDriverState *bs)
1013{
1014 BDRVSSHState *s = bs->opaque;
1015
1016 int has_zero_init = 0;
1017
1018 if (s->attrs->type == SSH_FILEXFER_TYPE_REGULAR) {
1019 has_zero_init = 1;
1020 }
1021
1022 return has_zero_init;
1023}
1024
1025typedef struct BDRVSSHRestart {
1026 BlockDriverState *bs;
1027 Coroutine *co;
1028} BDRVSSHRestart;
1029
1030static void restart_coroutine(void *opaque)
1031{
1032 BDRVSSHRestart *restart = opaque;
1033 BlockDriverState *bs = restart->bs;
1034 BDRVSSHState *s = bs->opaque;
1035 AioContext *ctx = bdrv_get_aio_context(bs);
1036
1037 trace_ssh_restart_coroutine(restart->co);
1038 aio_set_fd_handler(ctx, s->sock, false, NULL, NULL, NULL, NULL);
1039
1040 aio_co_wake(restart->co);
1041}
1042
1043
1044
1045
1046
1047static coroutine_fn void co_yield(BDRVSSHState *s, BlockDriverState *bs)
1048{
1049 int r;
1050 IOHandler *rd_handler = NULL, *wr_handler = NULL;
1051 BDRVSSHRestart restart = {
1052 .bs = bs,
1053 .co = qemu_coroutine_self()
1054 };
1055
1056 r = ssh_get_poll_flags(s->session);
1057
1058 if (r & SSH_READ_PENDING) {
1059 rd_handler = restart_coroutine;
1060 }
1061 if (r & SSH_WRITE_PENDING) {
1062 wr_handler = restart_coroutine;
1063 }
1064
1065 trace_ssh_co_yield(s->sock, rd_handler, wr_handler);
1066
1067 aio_set_fd_handler(bdrv_get_aio_context(bs), s->sock,
1068 false, rd_handler, wr_handler, NULL, &restart);
1069 qemu_coroutine_yield();
1070 trace_ssh_co_yield_back(s->sock);
1071}
1072
1073static coroutine_fn int ssh_read(BDRVSSHState *s, BlockDriverState *bs,
1074 int64_t offset, size_t size,
1075 QEMUIOVector *qiov)
1076{
1077 ssize_t r;
1078 size_t got;
1079 char *buf, *end_of_vec;
1080 struct iovec *i;
1081
1082 trace_ssh_read(offset, size);
1083
1084 trace_ssh_seek(offset);
1085 sftp_seek64(s->sftp_handle, offset);
1086
1087
1088
1089
1090
1091 i = &qiov->iov[0];
1092 buf = i->iov_base;
1093 end_of_vec = i->iov_base + i->iov_len;
1094
1095 for (got = 0; got < size; ) {
1096 size_t request_read_size;
1097 again:
1098
1099
1100
1101
1102
1103 request_read_size = MIN(end_of_vec - buf, 16384);
1104 trace_ssh_read_buf(buf, end_of_vec - buf, request_read_size);
1105 r = sftp_read(s->sftp_handle, buf, request_read_size);
1106 trace_ssh_read_return(r, sftp_get_error(s->sftp));
1107
1108 if (r == SSH_AGAIN) {
1109 co_yield(s, bs);
1110 goto again;
1111 }
1112 if (r == SSH_EOF || (r == 0 && sftp_get_error(s->sftp) == SSH_FX_EOF)) {
1113
1114 qemu_iovec_memset(qiov, got, 0, size - got);
1115 return 0;
1116 }
1117 if (r <= 0) {
1118 sftp_error_trace(s, "read");
1119 return -EIO;
1120 }
1121
1122 got += r;
1123 buf += r;
1124 if (buf >= end_of_vec && got < size) {
1125 i++;
1126 buf = i->iov_base;
1127 end_of_vec = i->iov_base + i->iov_len;
1128 }
1129 }
1130
1131 return 0;
1132}
1133
1134static coroutine_fn int ssh_co_readv(BlockDriverState *bs,
1135 int64_t sector_num,
1136 int nb_sectors, QEMUIOVector *qiov)
1137{
1138 BDRVSSHState *s = bs->opaque;
1139 int ret;
1140
1141 qemu_co_mutex_lock(&s->lock);
1142 ret = ssh_read(s, bs, sector_num * BDRV_SECTOR_SIZE,
1143 nb_sectors * BDRV_SECTOR_SIZE, qiov);
1144 qemu_co_mutex_unlock(&s->lock);
1145
1146 return ret;
1147}
1148
1149static int ssh_write(BDRVSSHState *s, BlockDriverState *bs,
1150 int64_t offset, size_t size,
1151 QEMUIOVector *qiov)
1152{
1153 ssize_t r;
1154 size_t written;
1155 char *buf, *end_of_vec;
1156 struct iovec *i;
1157
1158 trace_ssh_write(offset, size);
1159
1160 trace_ssh_seek(offset);
1161 sftp_seek64(s->sftp_handle, offset);
1162
1163
1164
1165
1166
1167 i = &qiov->iov[0];
1168 buf = i->iov_base;
1169 end_of_vec = i->iov_base + i->iov_len;
1170
1171 for (written = 0; written < size; ) {
1172 size_t request_write_size;
1173 again:
1174
1175
1176
1177
1178 request_write_size = MIN(end_of_vec - buf, 131072);
1179 trace_ssh_write_buf(buf, end_of_vec - buf, request_write_size);
1180 r = sftp_write(s->sftp_handle, buf, request_write_size);
1181 trace_ssh_write_return(r, sftp_get_error(s->sftp));
1182
1183 if (r == SSH_AGAIN) {
1184 co_yield(s, bs);
1185 goto again;
1186 }
1187 if (r < 0) {
1188 sftp_error_trace(s, "write");
1189 return -EIO;
1190 }
1191
1192 written += r;
1193 buf += r;
1194 if (buf >= end_of_vec && written < size) {
1195 i++;
1196 buf = i->iov_base;
1197 end_of_vec = i->iov_base + i->iov_len;
1198 }
1199
1200 if (offset + written > s->attrs->size) {
1201 s->attrs->size = offset + written;
1202 }
1203 }
1204
1205 return 0;
1206}
1207
1208static coroutine_fn int ssh_co_writev(BlockDriverState *bs,
1209 int64_t sector_num,
1210 int nb_sectors, QEMUIOVector *qiov,
1211 int flags)
1212{
1213 BDRVSSHState *s = bs->opaque;
1214 int ret;
1215
1216 assert(!flags);
1217 qemu_co_mutex_lock(&s->lock);
1218 ret = ssh_write(s, bs, sector_num * BDRV_SECTOR_SIZE,
1219 nb_sectors * BDRV_SECTOR_SIZE, qiov);
1220 qemu_co_mutex_unlock(&s->lock);
1221
1222 return ret;
1223}
1224
1225static void unsafe_flush_warning(BDRVSSHState *s, const char *what)
1226{
1227 if (!s->unsafe_flush_warning) {
1228 warn_report("ssh server %s does not support fsync",
1229 s->inet->host);
1230 if (what) {
1231 error_report("to support fsync, you need %s", what);
1232 }
1233 s->unsafe_flush_warning = true;
1234 }
1235}
1236
1237#ifdef HAVE_LIBSSH_0_8
1238
1239static coroutine_fn int ssh_flush(BDRVSSHState *s, BlockDriverState *bs)
1240{
1241 int r;
1242
1243 trace_ssh_flush();
1244
1245 if (!sftp_extension_supported(s->sftp, "fsync@openssh.com", "1")) {
1246 unsafe_flush_warning(s, "OpenSSH >= 6.3");
1247 return 0;
1248 }
1249 again:
1250 r = sftp_fsync(s->sftp_handle);
1251 if (r == SSH_AGAIN) {
1252 co_yield(s, bs);
1253 goto again;
1254 }
1255 if (r < 0) {
1256 sftp_error_trace(s, "fsync");
1257 return -EIO;
1258 }
1259
1260 return 0;
1261}
1262
1263static coroutine_fn int ssh_co_flush(BlockDriverState *bs)
1264{
1265 BDRVSSHState *s = bs->opaque;
1266 int ret;
1267
1268 qemu_co_mutex_lock(&s->lock);
1269 ret = ssh_flush(s, bs);
1270 qemu_co_mutex_unlock(&s->lock);
1271
1272 return ret;
1273}
1274
1275#else
1276
1277static coroutine_fn int ssh_co_flush(BlockDriverState *bs)
1278{
1279 BDRVSSHState *s = bs->opaque;
1280
1281 unsafe_flush_warning(s, "libssh >= 0.8.0");
1282 return 0;
1283}
1284
1285#endif
1286
1287static int64_t ssh_getlength(BlockDriverState *bs)
1288{
1289 BDRVSSHState *s = bs->opaque;
1290 int64_t length;
1291
1292
1293 length = (int64_t) s->attrs->size;
1294 trace_ssh_getlength(length);
1295
1296 return length;
1297}
1298
1299static int coroutine_fn ssh_co_truncate(BlockDriverState *bs, int64_t offset,
1300 bool exact, PreallocMode prealloc,
1301 Error **errp)
1302{
1303 BDRVSSHState *s = bs->opaque;
1304
1305 if (prealloc != PREALLOC_MODE_OFF) {
1306 error_setg(errp, "Unsupported preallocation mode '%s'",
1307 PreallocMode_str(prealloc));
1308 return -ENOTSUP;
1309 }
1310
1311 if (offset < s->attrs->size) {
1312 error_setg(errp, "ssh driver does not support shrinking files");
1313 return -ENOTSUP;
1314 }
1315
1316 if (offset == s->attrs->size) {
1317 return 0;
1318 }
1319
1320 return ssh_grow_file(s, offset, errp);
1321}
1322
1323static void ssh_refresh_filename(BlockDriverState *bs)
1324{
1325 BDRVSSHState *s = bs->opaque;
1326 const char *path, *host_key_check;
1327 int ret;
1328
1329
1330
1331
1332
1333 if (s->inet->has_ipv4 || s->inet->has_ipv6 || s->inet->has_to ||
1334 s->inet->has_numeric)
1335 {
1336 return;
1337 }
1338
1339 path = qdict_get_try_str(bs->full_open_options, "path");
1340 assert(path);
1341
1342 host_key_check = qdict_get_try_str(bs->full_open_options, "host_key_check");
1343
1344 ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
1345 "ssh://%s@%s:%s%s%s%s",
1346 s->user, s->inet->host, s->inet->port, path,
1347 host_key_check ? "?host_key_check=" : "",
1348 host_key_check ?: "");
1349 if (ret >= sizeof(bs->exact_filename)) {
1350
1351 bs->exact_filename[0] = '\0';
1352 }
1353}
1354
1355static char *ssh_bdrv_dirname(BlockDriverState *bs, Error **errp)
1356{
1357 if (qdict_haskey(bs->full_open_options, "host_key_check")) {
1358
1359
1360
1361
1362 error_setg(errp,
1363 "Cannot generate a base directory with host_key_check set");
1364 return NULL;
1365 }
1366
1367 if (bs->exact_filename[0] == '\0') {
1368 error_setg(errp, "Cannot generate a base directory for this ssh node");
1369 return NULL;
1370 }
1371
1372 return path_combine(bs->exact_filename, "");
1373}
1374
1375static const char *const ssh_strong_runtime_opts[] = {
1376 "host",
1377 "port",
1378 "path",
1379 "user",
1380 "host_key_check",
1381 "server.",
1382
1383 NULL
1384};
1385
1386static BlockDriver bdrv_ssh = {
1387 .format_name = "ssh",
1388 .protocol_name = "ssh",
1389 .instance_size = sizeof(BDRVSSHState),
1390 .bdrv_parse_filename = ssh_parse_filename,
1391 .bdrv_file_open = ssh_file_open,
1392 .bdrv_co_create = ssh_co_create,
1393 .bdrv_co_create_opts = ssh_co_create_opts,
1394 .bdrv_close = ssh_close,
1395 .bdrv_has_zero_init = ssh_has_zero_init,
1396 .bdrv_has_zero_init_truncate = ssh_has_zero_init,
1397 .bdrv_co_readv = ssh_co_readv,
1398 .bdrv_co_writev = ssh_co_writev,
1399 .bdrv_getlength = ssh_getlength,
1400 .bdrv_co_truncate = ssh_co_truncate,
1401 .bdrv_co_flush_to_disk = ssh_co_flush,
1402 .bdrv_refresh_filename = ssh_refresh_filename,
1403 .bdrv_dirname = ssh_bdrv_dirname,
1404 .create_opts = &ssh_create_opts,
1405 .strong_runtime_opts = ssh_strong_runtime_opts,
1406};
1407
1408static void bdrv_ssh_init(void)
1409{
1410 int r;
1411
1412 r = ssh_init();
1413 if (r != 0) {
1414 fprintf(stderr, "libssh initialization failed, %d\n", r);
1415 exit(EXIT_FAILURE);
1416 }
1417
1418#if TRACE_LIBSSH != 0
1419 ssh_set_log_level(TRACE_LIBSSH);
1420#endif
1421
1422 bdrv_register(&bdrv_ssh);
1423}
1424
1425block_init(bdrv_ssh_init);
1426