| 1 | /* |
| 2 | * Secure Shell (ssh) backend for QEMU. |
| 3 | * |
| 4 | * Copyright (C) 2013 Red Hat Inc., Richard W.M. Jones <rjones@redhat.com> |
| 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 | |
| 27 | #include <libssh/libssh.h> |
| 28 | #include <libssh/sftp.h> |
| 29 | |
| 30 | #include "block/block-io.h" |
| 31 | #include "block/block_int.h" |
| 32 | #include "block/qdict.h" |
| 33 | #include "qapi/error.h" |
| 34 | #include "qemu/error-report.h" |
| 35 | #include "qemu/module.h" |
| 36 | #include "qemu/option.h" |
| 37 | #include "qemu/ctype.h" |
| 38 | #include "qemu/cutils.h" |
| 39 | #include "qemu/sockets.h" |
| 40 | #include "qapi/qapi-visit-sockets.h" |
| 41 | #include "qapi/qapi-visit-block-core.h" |
| 42 | #include "qobject/qdict.h" |
| 43 | #include "qobject/qstring.h" |
| 44 | #include "qapi/qobject-input-visitor.h" |
| 45 | #include "qapi/qobject-output-visitor.h" |
| 46 | #include "trace.h" |
| 47 | |
| 48 | /* |
| 49 | * TRACE_LIBSSH=<level> enables tracing in libssh itself. |
| 50 | * The meaning of <level> is described here: |
| 51 | * http://api.libssh.org/master/group__libssh__log.html |
| 52 | */ |
| 53 | #define TRACE_LIBSSH 0 /* see: SSH_LOG_* */ |
| 54 | |
| 55 | typedef struct BDRVSSHState { |
| 56 | /* Coroutine. */ |
| 57 | CoMutex lock; |
| 58 | |
| 59 | /* SSH connection. */ |
| 60 | int sock; /* socket */ |
| 61 | ssh_session session; /* ssh session */ |
| 62 | sftp_session sftp; /* sftp session */ |
| 63 | sftp_file sftp_handle; /* sftp remote file handle */ |
| 64 | |
| 65 | /* |
| 66 | * File attributes at open. We try to keep the .size field |
| 67 | * updated if it changes (eg by writing at the end of the file). |
| 68 | */ |
| 69 | sftp_attributes attrs; |
| 70 | |
| 71 | InetSocketAddress *inet; |
| 72 | |
| 73 | /* Used to warn if 'flush' is not supported. */ |
| 74 | bool unsafe_flush_warning; |
| 75 | |
| 76 | /* |
| 77 | * Store the user name for ssh_refresh_filename() because the |
| 78 | * default depends on the system you are on -- therefore, when we |
| 79 | * generate a filename, it should always contain the user name we |
| 80 | * are actually using. |
| 81 | */ |
| 82 | char *user; |
| 83 | } BDRVSSHState; |
| 84 | |
| 85 | static 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 | |
| 92 | static 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); /* This frees s->sock */ |
| 108 | } |
| 109 | } |
| 110 | |
| 111 | static void G_GNUC_PRINTF(3, 4) |
| 112 | session_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 | /* This is not an errno. See <libssh/libssh.h>. */ |
| 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 | |
| 136 | static void G_GNUC_PRINTF(3, 4) |
| 137 | sftp_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 | /* This is not an errno. See <libssh/libssh.h>. */ |
| 152 | ssh_err = ssh_get_error(s->session); |
| 153 | ssh_err_code = ssh_get_error_code(s->session); |
| 154 | /* See <libssh/sftp.h>. */ |
| 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 | |
| 166 | static 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 | /* This is not an errno. See <libssh/libssh.h>. */ |
| 173 | ssh_err = ssh_get_error(s->session); |
| 174 | ssh_err_code = ssh_get_error_code(s->session); |
| 175 | /* See <libssh/sftp.h>. */ |
| 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 | |
| 181 | static int parse_uri(const char *filename, QDict *options, Error **errp) |
| 182 | { |
| 183 | g_autoptr(GUri) uri = g_uri_parse(filename, G_URI_FLAGS_NONE, NULL); |
| 184 | const char *uri_host, *uri_path, *uri_user, *uri_query; |
| 185 | char *port_str; |
| 186 | int port; |
| 187 | g_autoptr(GError) gerror = NULL; |
| 188 | char *qp_name, *qp_value; |
| 189 | GUriParamsIter qp; |
| 190 | |
| 191 | if (!uri) { |
| 192 | return -EINVAL; |
| 193 | } |
| 194 | |
| 195 | if (g_strcmp0(g_uri_get_scheme(uri), "ssh") != 0) { |
| 196 | error_setg(errp, "URI scheme must be 'ssh'"); |
| 197 | return -EINVAL; |
| 198 | } |
| 199 | |
| 200 | uri_host = g_uri_get_host(uri); |
| 201 | if (!uri_host || g_str_equal(uri_host, "")) { |
| 202 | error_setg(errp, "missing hostname in URI"); |
| 203 | return -EINVAL; |
| 204 | } |
| 205 | |
| 206 | uri_path = g_uri_get_path(uri); |
| 207 | if (!uri_path || g_str_equal(uri_path, "")) { |
| 208 | error_setg(errp, "missing remote path in URI"); |
| 209 | return -EINVAL; |
| 210 | } |
| 211 | |
| 212 | uri_user = g_uri_get_user(uri); |
| 213 | if (uri_user && !g_str_equal(uri_user, "")) { |
| 214 | qdict_put_str(options, "user", uri_user); |
| 215 | } |
| 216 | |
| 217 | qdict_put_str(options, "server.host", uri_host); |
| 218 | |
| 219 | port = g_uri_get_port(uri); |
| 220 | port_str = g_strdup_printf("%d", port > 0 ? 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 | uri_query = g_uri_get_query(uri); |
| 227 | if (uri_query) { |
| 228 | g_uri_params_iter_init(&qp, uri_query, -1, "&", G_URI_PARAMS_NONE); |
| 229 | while (g_uri_params_iter_next(&qp, &qp_name, &qp_value, &gerror)) { |
| 230 | if (!qp_name || !qp_value || gerror) { |
| 231 | warn_report("Failed to parse SSH URI parameters '%s'", |
| 232 | uri_query); |
| 233 | break; |
| 234 | } |
| 235 | /* |
| 236 | * Pick out the query parameters that we understand, and ignore |
| 237 | * (or rather warn about) the rest. |
| 238 | */ |
| 239 | if (g_str_equal(qp_name, "host_key_check")) { |
| 240 | qdict_put_str(options, "host_key_check", qp_value); |
| 241 | } else { |
| 242 | warn_report("Unsupported parameter '%s' in URI", qp_name); |
| 243 | } |
| 244 | } |
| 245 | } |
| 246 | |
| 247 | return 0; |
| 248 | } |
| 249 | |
| 250 | static bool ssh_has_filename_options_conflict(QDict *options, Error **errp) |
| 251 | { |
| 252 | const QDictEntry *qe; |
| 253 | |
| 254 | for (qe = qdict_first(options); qe; qe = qdict_next(options, qe)) { |
| 255 | if (!strcmp(qe->key, "host") || |
| 256 | !strcmp(qe->key, "port") || |
| 257 | !strcmp(qe->key, "path") || |
| 258 | !strcmp(qe->key, "user") || |
| 259 | !strcmp(qe->key, "host_key_check") || |
| 260 | strstart(qe->key, "server.", NULL)) |
| 261 | { |
| 262 | error_setg(errp, "Option '%s' cannot be used with a file name", |
| 263 | qe->key); |
| 264 | return true; |
| 265 | } |
| 266 | } |
| 267 | |
| 268 | return false; |
| 269 | } |
| 270 | |
| 271 | static void ssh_parse_filename(const char *filename, QDict *options, |
| 272 | Error **errp) |
| 273 | { |
| 274 | if (ssh_has_filename_options_conflict(options, errp)) { |
| 275 | return; |
| 276 | } |
| 277 | |
| 278 | parse_uri(filename, options, errp); |
| 279 | } |
| 280 | |
| 281 | static int check_host_key_knownhosts(BDRVSSHState *s, Error **errp) |
| 282 | { |
| 283 | int ret; |
| 284 | enum ssh_known_hosts_e state; |
| 285 | int r; |
| 286 | ssh_key pubkey; |
| 287 | enum ssh_keytypes_e pubkey_type; |
| 288 | unsigned char *server_hash = NULL; |
| 289 | size_t server_hash_len; |
| 290 | char *fingerprint = NULL; |
| 291 | |
| 292 | state = ssh_session_is_known_server(s->session); |
| 293 | trace_ssh_server_status(state); |
| 294 | |
| 295 | switch (state) { |
| 296 | case SSH_KNOWN_HOSTS_OK: |
| 297 | /* OK */ |
| 298 | trace_ssh_check_host_key_knownhosts(); |
| 299 | break; |
| 300 | case SSH_KNOWN_HOSTS_CHANGED: |
| 301 | ret = -EINVAL; |
| 302 | r = ssh_get_server_publickey(s->session, &pubkey); |
| 303 | if (r == 0) { |
| 304 | r = ssh_get_publickey_hash(pubkey, SSH_PUBLICKEY_HASH_SHA256, |
| 305 | &server_hash, &server_hash_len); |
| 306 | pubkey_type = ssh_key_type(pubkey); |
| 307 | ssh_key_free(pubkey); |
| 308 | } |
| 309 | if (r == 0) { |
| 310 | fingerprint = ssh_get_fingerprint_hash(SSH_PUBLICKEY_HASH_SHA256, |
| 311 | server_hash, |
| 312 | server_hash_len); |
| 313 | ssh_clean_pubkey_hash(&server_hash); |
| 314 | } |
| 315 | if (fingerprint) { |
| 316 | error_setg(errp, |
| 317 | "host key (%s key with fingerprint %s) does not match " |
| 318 | "the one in known_hosts; this may be a possible attack", |
| 319 | ssh_key_type_to_char(pubkey_type), fingerprint); |
| 320 | ssh_string_free_char(fingerprint); |
| 321 | } else { |
| 322 | error_setg(errp, |
| 323 | "host key does not match the one in known_hosts; this " |
| 324 | "may be a possible attack"); |
| 325 | } |
| 326 | goto out; |
| 327 | case SSH_KNOWN_HOSTS_OTHER: |
| 328 | ret = -EINVAL; |
| 329 | error_setg(errp, |
| 330 | "host key for this server not found, another type exists"); |
| 331 | goto out; |
| 332 | case SSH_KNOWN_HOSTS_UNKNOWN: |
| 333 | ret = -EINVAL; |
| 334 | error_setg(errp, "no host key was found in known_hosts"); |
| 335 | goto out; |
| 336 | case SSH_KNOWN_HOSTS_NOT_FOUND: |
| 337 | ret = -ENOENT; |
| 338 | error_setg(errp, "known_hosts file not found"); |
| 339 | goto out; |
| 340 | case SSH_KNOWN_HOSTS_ERROR: |
| 341 | ret = -EINVAL; |
| 342 | error_setg(errp, "error while checking the host"); |
| 343 | goto out; |
| 344 | default: |
| 345 | ret = -EINVAL; |
| 346 | error_setg(errp, "error while checking for known server (%d)", state); |
| 347 | goto out; |
| 348 | } |
| 349 | |
| 350 | /* known_hosts checking successful. */ |
| 351 | ret = 0; |
| 352 | |
| 353 | out: |
| 354 | return ret; |
| 355 | } |
| 356 | |
| 357 | static unsigned hex2decimal(char ch) |
| 358 | { |
| 359 | if (ch >= '0' && ch <= '9') { |
| 360 | return (ch - '0'); |
| 361 | } else if (ch >= 'a' && ch <= 'f') { |
| 362 | return 10 + (ch - 'a'); |
| 363 | } else if (ch >= 'A' && ch <= 'F') { |
| 364 | return 10 + (ch - 'A'); |
| 365 | } |
| 366 | |
| 367 | return UINT_MAX; |
| 368 | } |
| 369 | |
| 370 | /* Compare the binary fingerprint (hash of host key) with the |
| 371 | * host_key_check parameter. |
| 372 | */ |
| 373 | static int compare_fingerprint(const unsigned char *fingerprint, size_t len, |
| 374 | const char *host_key_check) |
| 375 | { |
| 376 | unsigned c; |
| 377 | |
| 378 | while (len > 0) { |
| 379 | unsigned c0, c1; |
| 380 | while (*host_key_check == ':') |
| 381 | host_key_check++; |
| 382 | c0 = hex2decimal(host_key_check[0]); |
| 383 | c1 = hex2decimal(host_key_check[1]); |
| 384 | if (c0 > 0xf || c1 > 0xf) { |
| 385 | return 1; |
| 386 | } |
| 387 | c = c0 * 16 + c1; |
| 388 | if (c - *fingerprint != 0) |
| 389 | return c - *fingerprint; |
| 390 | fingerprint++; |
| 391 | len--; |
| 392 | host_key_check += 2; |
| 393 | } |
| 394 | return *host_key_check - '\0'; |
| 395 | } |
| 396 | |
| 397 | static char *format_fingerprint(const unsigned char *fingerprint, size_t len) |
| 398 | { |
| 399 | static const char *hex = "0123456789abcdef"; |
| 400 | char *ret = g_new0(char, (len * 2) + 1); |
| 401 | for (size_t i = 0; i < len; i++) { |
| 402 | ret[i * 2] = hex[((fingerprint[i] >> 4) & 0xf)]; |
| 403 | ret[(i * 2) + 1] = hex[(fingerprint[i] & 0xf)]; |
| 404 | } |
| 405 | ret[len * 2] = '\0'; |
| 406 | return ret; |
| 407 | } |
| 408 | |
| 409 | static int |
| 410 | check_host_key_hash(BDRVSSHState *s, const char *hash, |
| 411 | enum ssh_publickey_hash_type type, const char *typestr, |
| 412 | Error **errp) |
| 413 | { |
| 414 | int r; |
| 415 | ssh_key pubkey; |
| 416 | unsigned char *server_hash; |
| 417 | size_t server_hash_len; |
| 418 | const char *keytype; |
| 419 | |
| 420 | r = ssh_get_server_publickey(s->session, &pubkey); |
| 421 | if (r != SSH_OK) { |
| 422 | session_error_setg(errp, s, "failed to read remote host key"); |
| 423 | return -EINVAL; |
| 424 | } |
| 425 | |
| 426 | keytype = ssh_key_type_to_char(ssh_key_type(pubkey)); |
| 427 | |
| 428 | r = ssh_get_publickey_hash(pubkey, type, &server_hash, &server_hash_len); |
| 429 | ssh_key_free(pubkey); |
| 430 | if (r != 0) { |
| 431 | session_error_setg(errp, s, |
| 432 | "failed reading the hash of the server SSH key"); |
| 433 | return -EINVAL; |
| 434 | } |
| 435 | |
| 436 | r = compare_fingerprint(server_hash, server_hash_len, hash); |
| 437 | if (r != 0) { |
| 438 | g_autofree char *server_fp = format_fingerprint(server_hash, |
| 439 | server_hash_len); |
| 440 | error_setg(errp, "remote host %s key fingerprint '%s:%s' " |
| 441 | "does not match host_key_check '%s:%s'", |
| 442 | keytype, typestr, server_fp, typestr, hash); |
| 443 | ssh_clean_pubkey_hash(&server_hash); |
| 444 | return -EPERM; |
| 445 | } |
| 446 | ssh_clean_pubkey_hash(&server_hash); |
| 447 | |
| 448 | return 0; |
| 449 | } |
| 450 | |
| 451 | static int check_host_key(BDRVSSHState *s, SshHostKeyCheck *hkc, Error **errp) |
| 452 | { |
| 453 | SshHostKeyCheckMode mode; |
| 454 | |
| 455 | if (hkc) { |
| 456 | mode = hkc->mode; |
| 457 | } else { |
| 458 | mode = SSH_HOST_KEY_CHECK_MODE_KNOWN_HOSTS; |
| 459 | } |
| 460 | |
| 461 | switch (mode) { |
| 462 | case SSH_HOST_KEY_CHECK_MODE_NONE: |
| 463 | return 0; |
| 464 | case SSH_HOST_KEY_CHECK_MODE_HASH: |
| 465 | if (hkc->u.hash.type == SSH_HOST_KEY_CHECK_HASH_TYPE_MD5) { |
| 466 | return check_host_key_hash(s, hkc->u.hash.hash, |
| 467 | SSH_PUBLICKEY_HASH_MD5, "md5", |
| 468 | errp); |
| 469 | } else if (hkc->u.hash.type == SSH_HOST_KEY_CHECK_HASH_TYPE_SHA1) { |
| 470 | return check_host_key_hash(s, hkc->u.hash.hash, |
| 471 | SSH_PUBLICKEY_HASH_SHA1, "sha1", |
| 472 | errp); |
| 473 | } else if (hkc->u.hash.type == SSH_HOST_KEY_CHECK_HASH_TYPE_SHA256) { |
| 474 | return check_host_key_hash(s, hkc->u.hash.hash, |
| 475 | SSH_PUBLICKEY_HASH_SHA256, "sha256", |
| 476 | errp); |
| 477 | } |
| 478 | g_assert_not_reached(); |
| 479 | case SSH_HOST_KEY_CHECK_MODE_KNOWN_HOSTS: |
| 480 | return check_host_key_knownhosts(s, errp); |
| 481 | default: |
| 482 | g_assert_not_reached(); |
| 483 | } |
| 484 | |
| 485 | return -EINVAL; |
| 486 | } |
| 487 | |
| 488 | static int authenticate(BDRVSSHState *s, Error **errp) |
| 489 | { |
| 490 | int r, ret; |
| 491 | int method; |
| 492 | |
| 493 | /* Try to authenticate with the "none" method. */ |
| 494 | r = ssh_userauth_none(s->session, NULL); |
| 495 | if (r == SSH_AUTH_ERROR) { |
| 496 | ret = -EPERM; |
| 497 | session_error_setg(errp, s, "failed to authenticate using none " |
| 498 | "authentication"); |
| 499 | goto out; |
| 500 | } else if (r == SSH_AUTH_SUCCESS) { |
| 501 | /* Authenticated! */ |
| 502 | ret = 0; |
| 503 | goto out; |
| 504 | } |
| 505 | |
| 506 | method = ssh_userauth_list(s->session, NULL); |
| 507 | trace_ssh_auth_methods(method); |
| 508 | |
| 509 | /* |
| 510 | * Try to authenticate with publickey, using the ssh-agent |
| 511 | * if available. |
| 512 | */ |
| 513 | if (method & SSH_AUTH_METHOD_PUBLICKEY) { |
| 514 | r = ssh_userauth_publickey_auto(s->session, NULL, NULL); |
| 515 | if (r == SSH_AUTH_ERROR) { |
| 516 | ret = -EINVAL; |
| 517 | session_error_setg(errp, s, "failed to authenticate using " |
| 518 | "publickey authentication"); |
| 519 | goto out; |
| 520 | } else if (r == SSH_AUTH_SUCCESS) { |
| 521 | /* Authenticated! */ |
| 522 | ret = 0; |
| 523 | goto out; |
| 524 | } |
| 525 | } |
| 526 | |
| 527 | ret = -EPERM; |
| 528 | error_setg(errp, "failed to authenticate using publickey authentication " |
| 529 | "and the identities held by your ssh-agent"); |
| 530 | |
| 531 | out: |
| 532 | return ret; |
| 533 | } |
| 534 | |
| 535 | static QemuOptsList ssh_runtime_opts = { |
| 536 | .name = "ssh", |
| 537 | .head = QTAILQ_HEAD_INITIALIZER(ssh_runtime_opts.head), |
| 538 | .desc = { |
| 539 | { |
| 540 | .name = "host", |
| 541 | .type = QEMU_OPT_STRING, |
| 542 | .help = "Host to connect to", |
| 543 | }, |
| 544 | { |
| 545 | .name = "port", |
| 546 | .type = QEMU_OPT_NUMBER, |
| 547 | .help = "Port to connect to", |
| 548 | }, |
| 549 | { |
| 550 | .name = "host_key_check", |
| 551 | .type = QEMU_OPT_STRING, |
| 552 | .help = "Defines how and what to check the host key against", |
| 553 | }, |
| 554 | { /* end of list */ } |
| 555 | }, |
| 556 | }; |
| 557 | |
| 558 | static bool ssh_process_legacy_options(QDict *output_opts, |
| 559 | QemuOpts *legacy_opts, |
| 560 | Error **errp) |
| 561 | { |
| 562 | const char *host = qemu_opt_get(legacy_opts, "host"); |
| 563 | const char *port = qemu_opt_get(legacy_opts, "port"); |
| 564 | const char *host_key_check = qemu_opt_get(legacy_opts, "host_key_check"); |
| 565 | |
| 566 | if (!host && port) { |
| 567 | error_setg(errp, "port may not be used without host"); |
| 568 | return false; |
| 569 | } |
| 570 | |
| 571 | if (host) { |
| 572 | qdict_put_str(output_opts, "server.host", host); |
| 573 | qdict_put_str(output_opts, "server.port", port ?: stringify(22)); |
| 574 | } |
| 575 | |
| 576 | if (host_key_check) { |
| 577 | if (strcmp(host_key_check, "no") == 0) { |
| 578 | qdict_put_str(output_opts, "host-key-check.mode", "none"); |
| 579 | } else if (strncmp(host_key_check, "md5:", 4) == 0) { |
| 580 | qdict_put_str(output_opts, "host-key-check.mode", "hash"); |
| 581 | qdict_put_str(output_opts, "host-key-check.type", "md5"); |
| 582 | qdict_put_str(output_opts, "host-key-check.hash", |
| 583 | &host_key_check[4]); |
| 584 | } else if (strncmp(host_key_check, "sha1:", 5) == 0) { |
| 585 | qdict_put_str(output_opts, "host-key-check.mode", "hash"); |
| 586 | qdict_put_str(output_opts, "host-key-check.type", "sha1"); |
| 587 | qdict_put_str(output_opts, "host-key-check.hash", |
| 588 | &host_key_check[5]); |
| 589 | } else if (strncmp(host_key_check, "sha256:", 7) == 0) { |
| 590 | qdict_put_str(output_opts, "host-key-check.mode", "hash"); |
| 591 | qdict_put_str(output_opts, "host-key-check.type", "sha256"); |
| 592 | qdict_put_str(output_opts, "host-key-check.hash", |
| 593 | &host_key_check[7]); |
| 594 | } else if (strcmp(host_key_check, "yes") == 0) { |
| 595 | qdict_put_str(output_opts, "host-key-check.mode", "known_hosts"); |
| 596 | } else { |
| 597 | error_setg(errp, "unknown host_key_check setting (%s)", |
| 598 | host_key_check); |
| 599 | return false; |
| 600 | } |
| 601 | } |
| 602 | |
| 603 | return true; |
| 604 | } |
| 605 | |
| 606 | static BlockdevOptionsSsh *ssh_parse_options(QDict *options, Error **errp) |
| 607 | { |
| 608 | BlockdevOptionsSsh *result = NULL; |
| 609 | QemuOpts *opts = NULL; |
| 610 | const QDictEntry *e; |
| 611 | Visitor *v; |
| 612 | |
| 613 | /* Translate legacy options */ |
| 614 | opts = qemu_opts_create(&ssh_runtime_opts, NULL, 0, &error_abort); |
| 615 | if (!qemu_opts_absorb_qdict(opts, options, errp)) { |
| 616 | goto fail; |
| 617 | } |
| 618 | |
| 619 | if (!ssh_process_legacy_options(options, opts, errp)) { |
| 620 | goto fail; |
| 621 | } |
| 622 | |
| 623 | /* Create the QAPI object */ |
| 624 | v = qobject_input_visitor_new_flat_confused(options, errp); |
| 625 | if (!v) { |
| 626 | goto fail; |
| 627 | } |
| 628 | |
| 629 | visit_type_BlockdevOptionsSsh(v, NULL, &result, errp); |
| 630 | visit_free(v); |
| 631 | if (!result) { |
| 632 | goto fail; |
| 633 | } |
| 634 | |
| 635 | /* Remove the processed options from the QDict (the visitor processes |
| 636 | * _all_ options in the QDict) */ |
| 637 | while ((e = qdict_first(options))) { |
| 638 | qdict_del(options, e->key); |
| 639 | } |
| 640 | |
| 641 | fail: |
| 642 | qemu_opts_del(opts); |
| 643 | return result; |
| 644 | } |
| 645 | |
| 646 | static int connect_to_ssh(BDRVSSHState *s, BlockdevOptionsSsh *opts, |
| 647 | int ssh_flags, int creat_mode, Error **errp) |
| 648 | { |
| 649 | int r, ret; |
| 650 | unsigned int port = 0; |
| 651 | int new_sock = -1; |
| 652 | |
| 653 | if (opts->user) { |
| 654 | s->user = g_strdup(opts->user); |
| 655 | } else { |
| 656 | s->user = g_strdup(g_get_user_name()); |
| 657 | if (!s->user) { |
| 658 | error_setg_errno(errp, errno, "Can't get user name"); |
| 659 | ret = -errno; |
| 660 | goto err; |
| 661 | } |
| 662 | } |
| 663 | |
| 664 | /* Pop the config into our state object, Exit if invalid */ |
| 665 | s->inet = opts->server; |
| 666 | opts->server = NULL; |
| 667 | |
| 668 | if (qemu_strtoui(s->inet->port, NULL, 10, &port) < 0) { |
| 669 | error_setg(errp, "Use only numeric port value"); |
| 670 | ret = -EINVAL; |
| 671 | goto err; |
| 672 | } |
| 673 | |
| 674 | /* Open the socket and connect. */ |
| 675 | new_sock = inet_connect_saddr(s->inet, errp); |
| 676 | if (new_sock < 0) { |
| 677 | ret = -EIO; |
| 678 | goto err; |
| 679 | } |
| 680 | |
| 681 | /* |
| 682 | * Try to disable the Nagle algorithm on TCP sockets to reduce latency, |
| 683 | * but do not fail if it cannot be disabled. |
| 684 | */ |
| 685 | r = socket_set_nodelay(new_sock); |
| 686 | if (r < 0) { |
| 687 | warn_report("can't set TCP_NODELAY for the ssh server %s: %s", |
| 688 | s->inet->host, strerror(errno)); |
| 689 | } |
| 690 | |
| 691 | /* Create SSH session. */ |
| 692 | s->session = ssh_new(); |
| 693 | if (!s->session) { |
| 694 | ret = -EINVAL; |
| 695 | session_error_setg(errp, s, "failed to initialize libssh session"); |
| 696 | goto err; |
| 697 | } |
| 698 | |
| 699 | /* |
| 700 | * Make sure we are in blocking mode during the connection and |
| 701 | * authentication phases. |
| 702 | */ |
| 703 | ssh_set_blocking(s->session, 1); |
| 704 | |
| 705 | r = ssh_options_set(s->session, SSH_OPTIONS_USER, s->user); |
| 706 | if (r < 0) { |
| 707 | ret = -EINVAL; |
| 708 | session_error_setg(errp, s, |
| 709 | "failed to set the user in the libssh session"); |
| 710 | goto err; |
| 711 | } |
| 712 | |
| 713 | r = ssh_options_set(s->session, SSH_OPTIONS_HOST, s->inet->host); |
| 714 | if (r < 0) { |
| 715 | ret = -EINVAL; |
| 716 | session_error_setg(errp, s, |
| 717 | "failed to set the host in the libssh session"); |
| 718 | goto err; |
| 719 | } |
| 720 | |
| 721 | if (port > 0) { |
| 722 | r = ssh_options_set(s->session, SSH_OPTIONS_PORT, &port); |
| 723 | if (r < 0) { |
| 724 | ret = -EINVAL; |
| 725 | session_error_setg(errp, s, |
| 726 | "failed to set the port in the libssh session"); |
| 727 | goto err; |
| 728 | } |
| 729 | } |
| 730 | |
| 731 | r = ssh_options_set(s->session, SSH_OPTIONS_COMPRESSION, "none"); |
| 732 | if (r < 0) { |
| 733 | ret = -EINVAL; |
| 734 | session_error_setg(errp, s, |
| 735 | "failed to disable the compression in the libssh " |
| 736 | "session"); |
| 737 | goto err; |
| 738 | } |
| 739 | |
| 740 | /* Read ~/.ssh/config. */ |
| 741 | r = ssh_options_parse_config(s->session, NULL); |
| 742 | if (r < 0) { |
| 743 | ret = -EINVAL; |
| 744 | session_error_setg(errp, s, "failed to parse ~/.ssh/config"); |
| 745 | goto err; |
| 746 | } |
| 747 | |
| 748 | r = ssh_options_set(s->session, SSH_OPTIONS_FD, &new_sock); |
| 749 | if (r < 0) { |
| 750 | ret = -EINVAL; |
| 751 | session_error_setg(errp, s, |
| 752 | "failed to set the socket in the libssh session"); |
| 753 | goto err; |
| 754 | } |
| 755 | /* libssh took ownership of the socket. */ |
| 756 | s->sock = new_sock; |
| 757 | new_sock = -1; |
| 758 | |
| 759 | /* Connect. */ |
| 760 | r = ssh_connect(s->session); |
| 761 | if (r != SSH_OK) { |
| 762 | ret = -EINVAL; |
| 763 | session_error_setg(errp, s, "failed to establish SSH session"); |
| 764 | goto err; |
| 765 | } |
| 766 | |
| 767 | /* Check the remote host's key against known_hosts. */ |
| 768 | ret = check_host_key(s, opts->host_key_check, errp); |
| 769 | if (ret < 0) { |
| 770 | goto err; |
| 771 | } |
| 772 | |
| 773 | /* Authenticate. */ |
| 774 | ret = authenticate(s, errp); |
| 775 | if (ret < 0) { |
| 776 | goto err; |
| 777 | } |
| 778 | |
| 779 | /* Start SFTP. */ |
| 780 | s->sftp = sftp_new(s->session); |
| 781 | if (!s->sftp) { |
| 782 | session_error_setg(errp, s, "failed to create sftp handle"); |
| 783 | ret = -EINVAL; |
| 784 | goto err; |
| 785 | } |
| 786 | |
| 787 | r = sftp_init(s->sftp); |
| 788 | if (r < 0) { |
| 789 | sftp_error_setg(errp, s, "failed to initialize sftp handle"); |
| 790 | ret = -EINVAL; |
| 791 | goto err; |
| 792 | } |
| 793 | |
| 794 | /* Open the remote file. */ |
| 795 | trace_ssh_connect_to_ssh(opts->path, ssh_flags, creat_mode); |
| 796 | s->sftp_handle = sftp_open(s->sftp, opts->path, ssh_flags, creat_mode); |
| 797 | if (!s->sftp_handle) { |
| 798 | sftp_error_setg(errp, s, "failed to open remote file '%s'", |
| 799 | opts->path); |
| 800 | ret = -EINVAL; |
| 801 | goto err; |
| 802 | } |
| 803 | |
| 804 | /* Make sure the SFTP file is handled in blocking mode. */ |
| 805 | sftp_file_set_blocking(s->sftp_handle); |
| 806 | |
| 807 | s->attrs = sftp_fstat(s->sftp_handle); |
| 808 | if (!s->attrs) { |
| 809 | sftp_error_setg(errp, s, "failed to read file attributes"); |
| 810 | return -EINVAL; |
| 811 | } |
| 812 | |
| 813 | return 0; |
| 814 | |
| 815 | err: |
| 816 | if (s->attrs) { |
| 817 | sftp_attributes_free(s->attrs); |
| 818 | } |
| 819 | s->attrs = NULL; |
| 820 | if (s->sftp_handle) { |
| 821 | sftp_close(s->sftp_handle); |
| 822 | } |
| 823 | s->sftp_handle = NULL; |
| 824 | if (s->sftp) { |
| 825 | sftp_free(s->sftp); |
| 826 | } |
| 827 | s->sftp = NULL; |
| 828 | if (s->session) { |
| 829 | ssh_disconnect(s->session); |
| 830 | ssh_free(s->session); |
| 831 | } |
| 832 | s->session = NULL; |
| 833 | s->sock = -1; |
| 834 | if (new_sock >= 0) { |
| 835 | close(new_sock); |
| 836 | } |
| 837 | |
| 838 | return ret; |
| 839 | } |
| 840 | |
| 841 | static int ssh_open(BlockDriverState *bs, QDict *options, int bdrv_flags, |
| 842 | Error **errp) |
| 843 | { |
| 844 | BDRVSSHState *s = bs->opaque; |
| 845 | BlockdevOptionsSsh *opts; |
| 846 | int ret; |
| 847 | int ssh_flags; |
| 848 | |
| 849 | ssh_state_init(s); |
| 850 | |
| 851 | ssh_flags = 0; |
| 852 | if (bdrv_flags & BDRV_O_RDWR) { |
| 853 | ssh_flags |= O_RDWR; |
| 854 | } else { |
| 855 | ssh_flags |= O_RDONLY; |
| 856 | } |
| 857 | |
| 858 | opts = ssh_parse_options(options, errp); |
| 859 | if (opts == NULL) { |
| 860 | return -EINVAL; |
| 861 | } |
| 862 | |
| 863 | /* Start up SSH. */ |
| 864 | ret = connect_to_ssh(s, opts, ssh_flags, 0, errp); |
| 865 | if (ret < 0) { |
| 866 | goto err; |
| 867 | } |
| 868 | |
| 869 | if (s->attrs->type == SSH_FILEXFER_TYPE_REGULAR) { |
| 870 | bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE; |
| 871 | } |
| 872 | |
| 873 | qapi_free_BlockdevOptionsSsh(opts); |
| 874 | |
| 875 | return 0; |
| 876 | |
| 877 | err: |
| 878 | qapi_free_BlockdevOptionsSsh(opts); |
| 879 | |
| 880 | return ret; |
| 881 | } |
| 882 | |
| 883 | /* Note: This is a blocking operation */ |
| 884 | static int ssh_grow_file(BDRVSSHState *s, int64_t offset, Error **errp) |
| 885 | { |
| 886 | ssize_t ret; |
| 887 | char c[1] = { '\0' }; |
| 888 | int was_blocking = ssh_is_blocking(s->session); |
| 889 | |
| 890 | /* offset must be strictly greater than the current size so we do |
| 891 | * not overwrite anything */ |
| 892 | assert(offset > 0 && offset > s->attrs->size); |
| 893 | |
| 894 | ssh_set_blocking(s->session, 1); |
| 895 | |
| 896 | sftp_seek64(s->sftp_handle, offset - 1); |
| 897 | ret = sftp_write(s->sftp_handle, c, 1); |
| 898 | |
| 899 | ssh_set_blocking(s->session, was_blocking); |
| 900 | |
| 901 | if (ret < 0) { |
| 902 | sftp_error_setg(errp, s, "Failed to grow file"); |
| 903 | return -EIO; |
| 904 | } |
| 905 | |
| 906 | s->attrs->size = offset; |
| 907 | return 0; |
| 908 | } |
| 909 | |
| 910 | static QemuOptsList ssh_create_opts = { |
| 911 | .name = "ssh-create-opts", |
| 912 | .head = QTAILQ_HEAD_INITIALIZER(ssh_create_opts.head), |
| 913 | .desc = { |
| 914 | { |
| 915 | .name = BLOCK_OPT_SIZE, |
| 916 | .type = QEMU_OPT_SIZE, |
| 917 | .help = "Virtual disk size" |
| 918 | }, |
| 919 | { /* end of list */ } |
| 920 | } |
| 921 | }; |
| 922 | |
| 923 | static int ssh_co_create(BlockdevCreateOptions *options, Error **errp) |
| 924 | { |
| 925 | BlockdevCreateOptionsSsh *opts = &options->u.ssh; |
| 926 | BDRVSSHState s; |
| 927 | int ret; |
| 928 | |
| 929 | assert(options->driver == BLOCKDEV_DRIVER_SSH); |
| 930 | |
| 931 | ssh_state_init(&s); |
| 932 | |
| 933 | ret = connect_to_ssh(&s, opts->location, |
| 934 | O_RDWR | O_CREAT | O_TRUNC, |
| 935 | 0644, errp); |
| 936 | if (ret < 0) { |
| 937 | goto fail; |
| 938 | } |
| 939 | |
| 940 | if (opts->size > 0) { |
| 941 | ret = ssh_grow_file(&s, opts->size, errp); |
| 942 | if (ret < 0) { |
| 943 | goto fail; |
| 944 | } |
| 945 | } |
| 946 | |
| 947 | ret = 0; |
| 948 | fail: |
| 949 | ssh_state_free(&s); |
| 950 | return ret; |
| 951 | } |
| 952 | |
| 953 | static int coroutine_fn ssh_co_create_opts(BlockDriver *drv, |
| 954 | const char *filename, |
| 955 | QemuOpts *opts, |
| 956 | Error **errp) |
| 957 | { |
| 958 | BlockdevCreateOptions *create_options; |
| 959 | BlockdevCreateOptionsSsh *ssh_opts; |
| 960 | int ret; |
| 961 | QDict *uri_options = NULL; |
| 962 | |
| 963 | create_options = g_new0(BlockdevCreateOptions, 1); |
| 964 | create_options->driver = BLOCKDEV_DRIVER_SSH; |
| 965 | ssh_opts = &create_options->u.ssh; |
| 966 | |
| 967 | /* Get desired file size. */ |
| 968 | ssh_opts->size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), |
| 969 | BDRV_SECTOR_SIZE); |
| 970 | trace_ssh_co_create_opts(ssh_opts->size); |
| 971 | |
| 972 | uri_options = qdict_new(); |
| 973 | ret = parse_uri(filename, uri_options, errp); |
| 974 | if (ret < 0) { |
| 975 | goto out; |
| 976 | } |
| 977 | |
| 978 | ssh_opts->location = ssh_parse_options(uri_options, errp); |
| 979 | if (ssh_opts->location == NULL) { |
| 980 | ret = -EINVAL; |
| 981 | goto out; |
| 982 | } |
| 983 | |
| 984 | ret = ssh_co_create(create_options, errp); |
| 985 | |
| 986 | out: |
| 987 | qobject_unref(uri_options); |
| 988 | qapi_free_BlockdevCreateOptions(create_options); |
| 989 | return ret; |
| 990 | } |
| 991 | |
| 992 | static void ssh_close(BlockDriverState *bs) |
| 993 | { |
| 994 | BDRVSSHState *s = bs->opaque; |
| 995 | |
| 996 | ssh_state_free(s); |
| 997 | } |
| 998 | |
| 999 | static int ssh_has_zero_init(BlockDriverState *bs) |
| 1000 | { |
| 1001 | BDRVSSHState *s = bs->opaque; |
| 1002 | /* Assume false, unless we can positively prove it's true. */ |
| 1003 | int has_zero_init = 0; |
| 1004 | |
| 1005 | if (s->attrs->type == SSH_FILEXFER_TYPE_REGULAR) { |
| 1006 | has_zero_init = 1; |
| 1007 | } |
| 1008 | |
| 1009 | return has_zero_init; |
| 1010 | } |
| 1011 | |
| 1012 | typedef struct BDRVSSHRestart { |
| 1013 | BDRVSSHState *s; |
| 1014 | Coroutine *co; |
| 1015 | } BDRVSSHRestart; |
| 1016 | |
| 1017 | static void restart_coroutine(void *opaque) |
| 1018 | { |
| 1019 | BDRVSSHRestart *restart = opaque; |
| 1020 | BDRVSSHState *s = restart->s; |
| 1021 | |
| 1022 | trace_ssh_restart_coroutine(restart->co); |
| 1023 | aio_set_fd_handler(qemu_get_current_aio_context(), s->sock, |
| 1024 | NULL, NULL, NULL, NULL, NULL); |
| 1025 | |
| 1026 | aio_co_wake(restart->co); |
| 1027 | } |
| 1028 | |
| 1029 | /* A non-blocking call returned EAGAIN, so yield, ensuring the |
| 1030 | * handlers are set up so that we'll be rescheduled when there is an |
| 1031 | * interesting event on the socket. |
| 1032 | */ |
| 1033 | static coroutine_fn void co_yield(BDRVSSHState *s) |
| 1034 | { |
| 1035 | int r; |
| 1036 | IOHandler *rd_handler = NULL, *wr_handler = NULL; |
| 1037 | AioContext *ctx = qemu_get_current_aio_context(); |
| 1038 | BDRVSSHRestart restart = { |
| 1039 | .s = s, |
| 1040 | .co = qemu_coroutine_self() |
| 1041 | }; |
| 1042 | |
| 1043 | r = ssh_get_poll_flags(s->session); |
| 1044 | |
| 1045 | if (r & SSH_READ_PENDING) { |
| 1046 | rd_handler = restart_coroutine; |
| 1047 | } |
| 1048 | if (r & SSH_WRITE_PENDING) { |
| 1049 | wr_handler = restart_coroutine; |
| 1050 | } |
| 1051 | |
| 1052 | trace_ssh_co_yield(s->sock, rd_handler, wr_handler); |
| 1053 | |
| 1054 | aio_set_fd_handler(ctx, s->sock, |
| 1055 | rd_handler, wr_handler, NULL, NULL, &restart); |
| 1056 | qemu_coroutine_yield(); |
| 1057 | trace_ssh_co_yield_back(s->sock); |
| 1058 | } |
| 1059 | |
| 1060 | static coroutine_fn int ssh_read(BDRVSSHState *s, BlockDriverState *bs, |
| 1061 | int64_t offset, size_t size, |
| 1062 | QEMUIOVector *qiov) |
| 1063 | { |
| 1064 | ssize_t r; |
| 1065 | size_t got; |
| 1066 | char *buf, *end_of_vec; |
| 1067 | struct iovec *i; |
| 1068 | |
| 1069 | trace_ssh_read(offset, size); |
| 1070 | |
| 1071 | trace_ssh_seek(offset); |
| 1072 | sftp_seek64(s->sftp_handle, offset); |
| 1073 | |
| 1074 | /* This keeps track of the current iovec element ('i'), where we |
| 1075 | * will write to next ('buf'), and the end of the current iovec |
| 1076 | * ('end_of_vec'). |
| 1077 | */ |
| 1078 | i = &qiov->iov[0]; |
| 1079 | buf = i->iov_base; |
| 1080 | end_of_vec = i->iov_base + i->iov_len; |
| 1081 | |
| 1082 | for (got = 0; got < size; ) { |
| 1083 | size_t request_read_size; |
| 1084 | again: |
| 1085 | /* |
| 1086 | * The size of SFTP packets is limited to 32K bytes, so limit |
| 1087 | * the amount of data requested to 16K, as libssh currently |
| 1088 | * does not handle multiple requests on its own. |
| 1089 | */ |
| 1090 | request_read_size = MIN(end_of_vec - buf, 16384); |
| 1091 | trace_ssh_read_buf(buf, end_of_vec - buf, request_read_size); |
| 1092 | r = sftp_read(s->sftp_handle, buf, request_read_size); |
| 1093 | trace_ssh_read_return(r, sftp_get_error(s->sftp)); |
| 1094 | |
| 1095 | if (r == SSH_AGAIN) { |
| 1096 | co_yield(s); |
| 1097 | goto again; |
| 1098 | } |
| 1099 | if (r == SSH_EOF || (r == 0 && sftp_get_error(s->sftp) == SSH_FX_EOF)) { |
| 1100 | /* EOF: Short read so pad the buffer with zeroes and return it. */ |
| 1101 | qemu_iovec_memset(qiov, got, 0, size - got); |
| 1102 | return 0; |
| 1103 | } |
| 1104 | if (r <= 0) { |
| 1105 | sftp_error_trace(s, "read"); |
| 1106 | return -EIO; |
| 1107 | } |
| 1108 | |
| 1109 | got += r; |
| 1110 | buf += r; |
| 1111 | if (buf >= end_of_vec && got < size) { |
| 1112 | i++; |
| 1113 | buf = i->iov_base; |
| 1114 | end_of_vec = i->iov_base + i->iov_len; |
| 1115 | } |
| 1116 | } |
| 1117 | |
| 1118 | return 0; |
| 1119 | } |
| 1120 | |
| 1121 | static coroutine_fn int ssh_co_readv(BlockDriverState *bs, |
| 1122 | int64_t sector_num, |
| 1123 | int nb_sectors, QEMUIOVector *qiov) |
| 1124 | { |
| 1125 | BDRVSSHState *s = bs->opaque; |
| 1126 | int ret; |
| 1127 | |
| 1128 | qemu_co_mutex_lock(&s->lock); |
| 1129 | ret = ssh_read(s, bs, sector_num * BDRV_SECTOR_SIZE, |
| 1130 | nb_sectors * BDRV_SECTOR_SIZE, qiov); |
| 1131 | qemu_co_mutex_unlock(&s->lock); |
| 1132 | |
| 1133 | return ret; |
| 1134 | } |
| 1135 | |
| 1136 | static coroutine_fn int ssh_write(BDRVSSHState *s, BlockDriverState *bs, |
| 1137 | int64_t offset, size_t size, |
| 1138 | QEMUIOVector *qiov) |
| 1139 | { |
| 1140 | ssize_t r; |
| 1141 | size_t written; |
| 1142 | char *buf, *end_of_vec; |
| 1143 | struct iovec *i; |
| 1144 | |
| 1145 | trace_ssh_write(offset, size); |
| 1146 | |
| 1147 | trace_ssh_seek(offset); |
| 1148 | sftp_seek64(s->sftp_handle, offset); |
| 1149 | |
| 1150 | /* This keeps track of the current iovec element ('i'), where we |
| 1151 | * will read from next ('buf'), and the end of the current iovec |
| 1152 | * ('end_of_vec'). |
| 1153 | */ |
| 1154 | i = &qiov->iov[0]; |
| 1155 | buf = i->iov_base; |
| 1156 | end_of_vec = i->iov_base + i->iov_len; |
| 1157 | |
| 1158 | for (written = 0; written < size; ) { |
| 1159 | size_t request_write_size; |
| 1160 | again: |
| 1161 | /* |
| 1162 | * Avoid too large data packets, as libssh currently does not |
| 1163 | * handle multiple requests on its own. |
| 1164 | */ |
| 1165 | request_write_size = MIN(end_of_vec - buf, 131072); |
| 1166 | trace_ssh_write_buf(buf, end_of_vec - buf, request_write_size); |
| 1167 | r = sftp_write(s->sftp_handle, buf, request_write_size); |
| 1168 | trace_ssh_write_return(r, sftp_get_error(s->sftp)); |
| 1169 | |
| 1170 | if (r == SSH_AGAIN) { |
| 1171 | co_yield(s); |
| 1172 | goto again; |
| 1173 | } |
| 1174 | if (r < 0) { |
| 1175 | sftp_error_trace(s, "write"); |
| 1176 | return -EIO; |
| 1177 | } |
| 1178 | |
| 1179 | written += r; |
| 1180 | buf += r; |
| 1181 | if (buf >= end_of_vec && written < size) { |
| 1182 | i++; |
| 1183 | buf = i->iov_base; |
| 1184 | end_of_vec = i->iov_base + i->iov_len; |
| 1185 | } |
| 1186 | |
| 1187 | if (offset + written > s->attrs->size) { |
| 1188 | s->attrs->size = offset + written; |
| 1189 | } |
| 1190 | } |
| 1191 | |
| 1192 | return 0; |
| 1193 | } |
| 1194 | |
| 1195 | static coroutine_fn int ssh_co_writev(BlockDriverState *bs, |
| 1196 | int64_t sector_num, |
| 1197 | int nb_sectors, QEMUIOVector *qiov, |
| 1198 | int flags) |
| 1199 | { |
| 1200 | BDRVSSHState *s = bs->opaque; |
| 1201 | int ret; |
| 1202 | |
| 1203 | qemu_co_mutex_lock(&s->lock); |
| 1204 | ret = ssh_write(s, bs, sector_num * BDRV_SECTOR_SIZE, |
| 1205 | nb_sectors * BDRV_SECTOR_SIZE, qiov); |
| 1206 | qemu_co_mutex_unlock(&s->lock); |
| 1207 | |
| 1208 | return ret; |
| 1209 | } |
| 1210 | |
| 1211 | static void unsafe_flush_warning(BDRVSSHState *s, const char *what) |
| 1212 | { |
| 1213 | if (!s->unsafe_flush_warning) { |
| 1214 | warn_report("ssh server %s does not support fsync", |
| 1215 | s->inet->host); |
| 1216 | if (what) { |
| 1217 | error_report("to support fsync, you need %s", what); |
| 1218 | } |
| 1219 | s->unsafe_flush_warning = true; |
| 1220 | } |
| 1221 | } |
| 1222 | |
| 1223 | static coroutine_fn int ssh_flush(BDRVSSHState *s, BlockDriverState *bs) |
| 1224 | { |
| 1225 | int r; |
| 1226 | |
| 1227 | trace_ssh_flush(); |
| 1228 | |
| 1229 | if (!sftp_extension_supported(s->sftp, "fsync@openssh.com", "1")) { |
| 1230 | unsafe_flush_warning(s, "OpenSSH >= 6.3"); |
| 1231 | return 0; |
| 1232 | } |
| 1233 | again: |
| 1234 | r = sftp_fsync(s->sftp_handle); |
| 1235 | if (r == SSH_AGAIN) { |
| 1236 | co_yield(s); |
| 1237 | goto again; |
| 1238 | } |
| 1239 | if (r < 0) { |
| 1240 | sftp_error_trace(s, "fsync"); |
| 1241 | return -EIO; |
| 1242 | } |
| 1243 | |
| 1244 | return 0; |
| 1245 | } |
| 1246 | |
| 1247 | static coroutine_fn int ssh_co_flush(BlockDriverState *bs) |
| 1248 | { |
| 1249 | BDRVSSHState *s = bs->opaque; |
| 1250 | int ret; |
| 1251 | |
| 1252 | qemu_co_mutex_lock(&s->lock); |
| 1253 | ret = ssh_flush(s, bs); |
| 1254 | qemu_co_mutex_unlock(&s->lock); |
| 1255 | |
| 1256 | return ret; |
| 1257 | } |
| 1258 | |
| 1259 | static int64_t coroutine_fn ssh_co_getlength(BlockDriverState *bs) |
| 1260 | { |
| 1261 | BDRVSSHState *s = bs->opaque; |
| 1262 | int64_t length; |
| 1263 | |
| 1264 | /* Note we cannot make a libssh call here. */ |
| 1265 | length = (int64_t) s->attrs->size; |
| 1266 | trace_ssh_getlength(length); |
| 1267 | |
| 1268 | return length; |
| 1269 | } |
| 1270 | |
| 1271 | static int coroutine_fn ssh_co_truncate(BlockDriverState *bs, int64_t offset, |
| 1272 | bool exact, PreallocMode prealloc, |
| 1273 | BdrvRequestFlags flags, Error **errp) |
| 1274 | { |
| 1275 | BDRVSSHState *s = bs->opaque; |
| 1276 | |
| 1277 | if (prealloc != PREALLOC_MODE_OFF) { |
| 1278 | error_setg(errp, "Unsupported preallocation mode '%s'", |
| 1279 | PreallocMode_str(prealloc)); |
| 1280 | return -ENOTSUP; |
| 1281 | } |
| 1282 | |
| 1283 | if (offset < s->attrs->size) { |
| 1284 | error_setg(errp, "ssh driver does not support shrinking files"); |
| 1285 | return -ENOTSUP; |
| 1286 | } |
| 1287 | |
| 1288 | if (offset == s->attrs->size) { |
| 1289 | return 0; |
| 1290 | } |
| 1291 | |
| 1292 | return ssh_grow_file(s, offset, errp); |
| 1293 | } |
| 1294 | |
| 1295 | static void ssh_refresh_filename(BlockDriverState *bs) |
| 1296 | { |
| 1297 | BDRVSSHState *s = bs->opaque; |
| 1298 | const char *path, *host_key_check; |
| 1299 | int ret; |
| 1300 | |
| 1301 | /* |
| 1302 | * None of these options can be represented in a plain "host:port" |
| 1303 | * format, so if any was given, we have to abort. |
| 1304 | */ |
| 1305 | if (s->inet->has_ipv4 || s->inet->has_ipv6 || s->inet->has_to || |
| 1306 | s->inet->has_numeric) |
| 1307 | { |
| 1308 | return; |
| 1309 | } |
| 1310 | |
| 1311 | path = qdict_get_try_str(bs->full_open_options, "path"); |
| 1312 | assert(path); /* mandatory option */ |
| 1313 | |
| 1314 | host_key_check = qdict_get_try_str(bs->full_open_options, "host_key_check"); |
| 1315 | |
| 1316 | ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename), |
| 1317 | "ssh://%s@%s:%s%s%s%s", |
| 1318 | s->user, s->inet->host, s->inet->port, path, |
| 1319 | host_key_check ? "?host_key_check=" : "", |
| 1320 | host_key_check ?: ""); |
| 1321 | if (ret >= sizeof(bs->exact_filename)) { |
| 1322 | /* An overflow makes the filename unusable, so do not report any */ |
| 1323 | bs->exact_filename[0] = '\0'; |
| 1324 | } |
| 1325 | } |
| 1326 | |
| 1327 | static char *ssh_bdrv_dirname(BlockDriverState *bs, Error **errp) |
| 1328 | { |
| 1329 | if (qdict_haskey(bs->full_open_options, "host_key_check")) { |
| 1330 | /* |
| 1331 | * We cannot generate a simple prefix if we would have to |
| 1332 | * append a query string. |
| 1333 | */ |
| 1334 | error_setg(errp, |
| 1335 | "Cannot generate a base directory with host_key_check set"); |
| 1336 | return NULL; |
| 1337 | } |
| 1338 | |
| 1339 | if (bs->exact_filename[0] == '\0') { |
| 1340 | error_setg(errp, "Cannot generate a base directory for this ssh node"); |
| 1341 | return NULL; |
| 1342 | } |
| 1343 | |
| 1344 | return path_combine(bs->exact_filename, ""); |
| 1345 | } |
| 1346 | |
| 1347 | static const char *const ssh_strong_runtime_opts[] = { |
| 1348 | "host", |
| 1349 | "port", |
| 1350 | "path", |
| 1351 | "user", |
| 1352 | "host_key_check", |
| 1353 | "server.", |
| 1354 | |
| 1355 | NULL |
| 1356 | }; |
| 1357 | |
| 1358 | static BlockDriver bdrv_ssh = { |
| 1359 | .format_name = "ssh", |
| 1360 | .protocol_name = "ssh", |
| 1361 | .instance_size = sizeof(BDRVSSHState), |
| 1362 | .bdrv_parse_filename = ssh_parse_filename, |
| 1363 | .bdrv_open = ssh_open, |
| 1364 | .bdrv_co_create = ssh_co_create, |
| 1365 | .bdrv_co_create_opts = ssh_co_create_opts, |
| 1366 | .bdrv_close = ssh_close, |
| 1367 | .bdrv_has_zero_init = ssh_has_zero_init, |
| 1368 | .bdrv_co_readv = ssh_co_readv, |
| 1369 | .bdrv_co_writev = ssh_co_writev, |
| 1370 | .bdrv_co_getlength = ssh_co_getlength, |
| 1371 | .bdrv_co_truncate = ssh_co_truncate, |
| 1372 | .bdrv_co_flush_to_disk = ssh_co_flush, |
| 1373 | .bdrv_refresh_filename = ssh_refresh_filename, |
| 1374 | .bdrv_dirname = ssh_bdrv_dirname, |
| 1375 | .create_opts = &ssh_create_opts, |
| 1376 | .strong_runtime_opts = ssh_strong_runtime_opts, |
| 1377 | }; |
| 1378 | |
| 1379 | static void bdrv_ssh_init(void) |
| 1380 | { |
| 1381 | int r; |
| 1382 | |
| 1383 | r = ssh_init(); |
| 1384 | if (r != 0) { |
| 1385 | fprintf(stderr, "libssh initialization failed, %d\n", r); |
| 1386 | exit(EXIT_FAILURE); |
| 1387 | } |
| 1388 | |
| 1389 | #if TRACE_LIBSSH != 0 |
| 1390 | ssh_set_log_level(TRACE_LIBSSH); |
| 1391 | #endif |
| 1392 | |
| 1393 | bdrv_register(&bdrv_ssh); |
| 1394 | } |
| 1395 | |
| 1396 | block_init(bdrv_ssh_init); |