1 /* 2 * QEMU Guest Agent common/cross-platform command implementations 3 * 4 * Copyright IBM Corp. 2012 5 * 6 * Authors: 7 * Michael Roth <mdroth@linux.vnet.ibm.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or later. 10 * See the COPYING file in the top-level directory. 11 */ 12 13 #include "qemu/osdep.h" 14 #include "qemu/units.h" 15 #include "guest-agent-core.h" 16 #include "qga-qapi-commands.h" 17 #include "qapi/error.h" 18 #include "qapi/qmp/qerror.h" 19 #include "qemu/base64.h" 20 #include "qemu/cutils.h" 21 #include "qemu/atomic.h" 22 #include "commands-common.h" 23 24 /* Maximum captured guest-exec out_data/err_data - 16MB */ 25 #define GUEST_EXEC_MAX_OUTPUT (16*1024*1024) 26 /* Allocation and I/O buffer for reading guest-exec out_data/err_data - 4KB */ 27 #define GUEST_EXEC_IO_SIZE (4*1024) 28 /* 29 * Maximum file size to read - 48MB 30 * 31 * (48MB + Base64 3:4 overhead = JSON parser 64 MB limit) 32 */ 33 #define GUEST_FILE_READ_COUNT_MAX (48 * MiB) 34 35 /* Note: in some situations, like with the fsfreeze, logging may be 36 * temporarilly disabled. if it is necessary that a command be able 37 * to log for accounting purposes, check ga_logging_enabled() beforehand, 38 * and use the QERR_QGA_LOGGING_DISABLED to generate an error 39 */ 40 void slog(const gchar *fmt, ...) 41 { 42 va_list ap; 43 44 va_start(ap, fmt); 45 g_logv("syslog", G_LOG_LEVEL_INFO, fmt, ap); 46 va_end(ap); 47 } 48 49 int64_t qmp_guest_sync_delimited(int64_t id, Error **errp) 50 { 51 ga_set_response_delimited(ga_state); 52 return id; 53 } 54 55 int64_t qmp_guest_sync(int64_t id, Error **errp) 56 { 57 return id; 58 } 59 60 void qmp_guest_ping(Error **errp) 61 { 62 slog("guest-ping called"); 63 } 64 65 static void qmp_command_info(const QmpCommand *cmd, void *opaque) 66 { 67 GuestAgentInfo *info = opaque; 68 GuestAgentCommandInfo *cmd_info; 69 70 cmd_info = g_new0(GuestAgentCommandInfo, 1); 71 cmd_info->name = g_strdup(qmp_command_name(cmd)); 72 cmd_info->enabled = qmp_command_is_enabled(cmd); 73 cmd_info->success_response = qmp_has_success_response(cmd); 74 75 QAPI_LIST_PREPEND(info->supported_commands, cmd_info); 76 } 77 78 struct GuestAgentInfo *qmp_guest_info(Error **errp) 79 { 80 GuestAgentInfo *info = g_new0(GuestAgentInfo, 1); 81 82 info->version = g_strdup(QEMU_VERSION); 83 qmp_for_each_command(&ga_commands, qmp_command_info, info); 84 return info; 85 } 86 87 struct GuestExecIOData { 88 guchar *data; 89 gsize size; 90 gsize length; 91 bool closed; 92 bool truncated; 93 const char *name; 94 }; 95 typedef struct GuestExecIOData GuestExecIOData; 96 97 struct GuestExecInfo { 98 GPid pid; 99 int64_t pid_numeric; 100 gint status; 101 bool has_output; 102 bool finished; 103 GuestExecIOData in; 104 GuestExecIOData out; 105 GuestExecIOData err; 106 QTAILQ_ENTRY(GuestExecInfo) next; 107 }; 108 typedef struct GuestExecInfo GuestExecInfo; 109 110 static struct { 111 QTAILQ_HEAD(, GuestExecInfo) processes; 112 } guest_exec_state = { 113 .processes = QTAILQ_HEAD_INITIALIZER(guest_exec_state.processes), 114 }; 115 116 static int64_t gpid_to_int64(GPid pid) 117 { 118 #ifdef G_OS_WIN32 119 return GetProcessId(pid); 120 #else 121 return (int64_t)pid; 122 #endif 123 } 124 125 static GuestExecInfo *guest_exec_info_add(GPid pid) 126 { 127 GuestExecInfo *gei; 128 129 gei = g_new0(GuestExecInfo, 1); 130 gei->pid = pid; 131 gei->pid_numeric = gpid_to_int64(pid); 132 QTAILQ_INSERT_TAIL(&guest_exec_state.processes, gei, next); 133 134 return gei; 135 } 136 137 static GuestExecInfo *guest_exec_info_find(int64_t pid_numeric) 138 { 139 GuestExecInfo *gei; 140 141 QTAILQ_FOREACH(gei, &guest_exec_state.processes, next) { 142 if (gei->pid_numeric == pid_numeric) { 143 return gei; 144 } 145 } 146 147 return NULL; 148 } 149 150 GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **errp) 151 { 152 GuestExecInfo *gei; 153 GuestExecStatus *ges; 154 155 slog("guest-exec-status called, pid: %u", (uint32_t)pid); 156 157 gei = guest_exec_info_find(pid); 158 if (gei == NULL) { 159 error_setg(errp, QERR_INVALID_PARAMETER, "pid"); 160 return NULL; 161 } 162 163 ges = g_new0(GuestExecStatus, 1); 164 165 bool finished = qatomic_mb_read(&gei->finished); 166 167 /* need to wait till output channels are closed 168 * to be sure we captured all output at this point */ 169 if (gei->has_output) { 170 finished = finished && qatomic_mb_read(&gei->out.closed); 171 finished = finished && qatomic_mb_read(&gei->err.closed); 172 } 173 174 ges->exited = finished; 175 if (finished) { 176 /* Glib has no portable way to parse exit status. 177 * On UNIX, we can get either exit code from normal termination 178 * or signal number. 179 * On Windows, it is either the same exit code or the exception 180 * value for an unhandled exception that caused the process 181 * to terminate. 182 * See MSDN for GetExitCodeProcess() and ntstatus.h for possible 183 * well-known codes, e.g. C0000005 ACCESS_DENIED - analog of SIGSEGV 184 * References: 185 * https://msdn.microsoft.com/en-us/library/windows/desktop/ms683189(v=vs.85).aspx 186 * https://msdn.microsoft.com/en-us/library/aa260331(v=vs.60).aspx 187 */ 188 #ifdef G_OS_WIN32 189 /* Additionally WIN32 does not provide any additional information 190 * on whether the child exited or terminated via signal. 191 * We use this simple range check to distinguish application exit code 192 * (usually value less then 256) and unhandled exception code with 193 * ntstatus (always value greater then 0xC0000005). */ 194 if ((uint32_t)gei->status < 0xC0000000U) { 195 ges->has_exitcode = true; 196 ges->exitcode = gei->status; 197 } else { 198 ges->has_signal = true; 199 ges->signal = gei->status; 200 } 201 #else 202 if (WIFEXITED(gei->status)) { 203 ges->has_exitcode = true; 204 ges->exitcode = WEXITSTATUS(gei->status); 205 } else if (WIFSIGNALED(gei->status)) { 206 ges->has_signal = true; 207 ges->signal = WTERMSIG(gei->status); 208 } 209 #endif 210 if (gei->out.length > 0) { 211 ges->has_out_data = true; 212 ges->out_data = g_base64_encode(gei->out.data, gei->out.length); 213 g_free(gei->out.data); 214 ges->has_out_truncated = gei->out.truncated; 215 } 216 217 if (gei->err.length > 0) { 218 ges->has_err_data = true; 219 ges->err_data = g_base64_encode(gei->err.data, gei->err.length); 220 g_free(gei->err.data); 221 ges->has_err_truncated = gei->err.truncated; 222 } 223 224 QTAILQ_REMOVE(&guest_exec_state.processes, gei, next); 225 g_free(gei); 226 } 227 228 return ges; 229 } 230 231 /* Get environment variables or arguments array for execve(). */ 232 static char **guest_exec_get_args(const strList *entry, bool log) 233 { 234 const strList *it; 235 int count = 1, i = 0; /* reserve for NULL terminator */ 236 char **args; 237 char *str; /* for logging array of arguments */ 238 size_t str_size = 1; 239 240 for (it = entry; it != NULL; it = it->next) { 241 count++; 242 str_size += 1 + strlen(it->value); 243 } 244 245 str = g_malloc(str_size); 246 *str = 0; 247 args = g_malloc(count * sizeof(char *)); 248 for (it = entry; it != NULL; it = it->next) { 249 args[i++] = it->value; 250 pstrcat(str, str_size, it->value); 251 if (it->next) { 252 pstrcat(str, str_size, " "); 253 } 254 } 255 args[i] = NULL; 256 257 if (log) { 258 slog("guest-exec called: \"%s\"", str); 259 } 260 g_free(str); 261 262 return args; 263 } 264 265 static void guest_exec_child_watch(GPid pid, gint status, gpointer data) 266 { 267 GuestExecInfo *gei = (GuestExecInfo *)data; 268 269 g_debug("guest_exec_child_watch called, pid: %d, status: %u", 270 (int32_t)gpid_to_int64(pid), (uint32_t)status); 271 272 gei->status = status; 273 qatomic_mb_set(&gei->finished, true); 274 275 g_spawn_close_pid(pid); 276 } 277 278 /** Reset ignored signals back to default. */ 279 static void guest_exec_task_setup(gpointer data) 280 { 281 #if !defined(G_OS_WIN32) 282 struct sigaction sigact; 283 284 memset(&sigact, 0, sizeof(struct sigaction)); 285 sigact.sa_handler = SIG_DFL; 286 287 if (sigaction(SIGPIPE, &sigact, NULL) != 0) { 288 slog("sigaction() failed to reset child process's SIGPIPE: %s", 289 strerror(errno)); 290 } 291 #endif 292 } 293 294 static gboolean guest_exec_input_watch(GIOChannel *ch, 295 GIOCondition cond, gpointer p_) 296 { 297 GuestExecIOData *p = (GuestExecIOData *)p_; 298 gsize bytes_written = 0; 299 GIOStatus status; 300 GError *gerr = NULL; 301 302 /* nothing left to write */ 303 if (p->size == p->length) { 304 goto done; 305 } 306 307 status = g_io_channel_write_chars(ch, (gchar *)p->data + p->length, 308 p->size - p->length, &bytes_written, &gerr); 309 310 /* can be not 0 even if not G_IO_STATUS_NORMAL */ 311 if (bytes_written != 0) { 312 p->length += bytes_written; 313 } 314 315 /* continue write, our callback will be called again */ 316 if (status == G_IO_STATUS_NORMAL || status == G_IO_STATUS_AGAIN) { 317 return true; 318 } 319 320 if (gerr) { 321 g_warning("qga: i/o error writing to input_data channel: %s", 322 gerr->message); 323 g_error_free(gerr); 324 } 325 326 done: 327 g_io_channel_shutdown(ch, true, NULL); 328 g_io_channel_unref(ch); 329 qatomic_mb_set(&p->closed, true); 330 g_free(p->data); 331 332 return false; 333 } 334 335 static gboolean guest_exec_output_watch(GIOChannel *ch, 336 GIOCondition cond, gpointer p_) 337 { 338 GuestExecIOData *p = (GuestExecIOData *)p_; 339 gsize bytes_read; 340 GIOStatus gstatus; 341 342 if (cond == G_IO_HUP || cond == G_IO_ERR) { 343 goto close; 344 } 345 346 if (p->size == p->length) { 347 gpointer t = NULL; 348 if (!p->truncated && p->size < GUEST_EXEC_MAX_OUTPUT) { 349 t = g_try_realloc(p->data, p->size + GUEST_EXEC_IO_SIZE); 350 } 351 if (t == NULL) { 352 /* ignore truncated output */ 353 gchar buf[GUEST_EXEC_IO_SIZE]; 354 355 p->truncated = true; 356 gstatus = g_io_channel_read_chars(ch, buf, sizeof(buf), 357 &bytes_read, NULL); 358 if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) { 359 goto close; 360 } 361 362 return true; 363 } 364 p->size += GUEST_EXEC_IO_SIZE; 365 p->data = t; 366 } 367 368 /* Calling read API once. 369 * On next available data our callback will be called again */ 370 gstatus = g_io_channel_read_chars(ch, (gchar *)p->data + p->length, 371 p->size - p->length, &bytes_read, NULL); 372 if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) { 373 goto close; 374 } 375 376 p->length += bytes_read; 377 378 return true; 379 380 close: 381 g_io_channel_shutdown(ch, true, NULL); 382 g_io_channel_unref(ch); 383 qatomic_mb_set(&p->closed, true); 384 return false; 385 } 386 387 GuestExec *qmp_guest_exec(const char *path, 388 bool has_arg, strList *arg, 389 bool has_env, strList *env, 390 bool has_input_data, const char *input_data, 391 bool has_capture_output, bool capture_output, 392 Error **errp) 393 { 394 GPid pid; 395 GuestExec *ge = NULL; 396 GuestExecInfo *gei; 397 char **argv, **envp; 398 strList arglist; 399 gboolean ret; 400 GError *gerr = NULL; 401 gint in_fd, out_fd, err_fd; 402 GIOChannel *in_ch, *out_ch, *err_ch; 403 GSpawnFlags flags; 404 bool has_output = (has_capture_output && capture_output); 405 uint8_t *input = NULL; 406 size_t ninput = 0; 407 408 arglist.value = (char *)path; 409 arglist.next = has_arg ? arg : NULL; 410 411 if (has_input_data) { 412 input = qbase64_decode(input_data, -1, &ninput, errp); 413 if (!input) { 414 return NULL; 415 } 416 } 417 418 argv = guest_exec_get_args(&arglist, true); 419 envp = has_env ? guest_exec_get_args(env, false) : NULL; 420 421 flags = G_SPAWN_SEARCH_PATH | G_SPAWN_DO_NOT_REAP_CHILD | 422 G_SPAWN_SEARCH_PATH_FROM_ENVP; 423 if (!has_output) { 424 flags |= G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL; 425 } 426 427 ret = g_spawn_async_with_pipes(NULL, argv, envp, flags, 428 guest_exec_task_setup, NULL, &pid, has_input_data ? &in_fd : NULL, 429 has_output ? &out_fd : NULL, has_output ? &err_fd : NULL, &gerr); 430 if (!ret) { 431 error_setg(errp, QERR_QGA_COMMAND_FAILED, gerr->message); 432 g_error_free(gerr); 433 goto done; 434 } 435 436 ge = g_new0(GuestExec, 1); 437 ge->pid = gpid_to_int64(pid); 438 439 gei = guest_exec_info_add(pid); 440 gei->has_output = has_output; 441 g_child_watch_add(pid, guest_exec_child_watch, gei); 442 443 if (has_input_data) { 444 gei->in.data = input; 445 gei->in.size = ninput; 446 #ifdef G_OS_WIN32 447 in_ch = g_io_channel_win32_new_fd(in_fd); 448 #else 449 in_ch = g_io_channel_unix_new(in_fd); 450 #endif 451 g_io_channel_set_encoding(in_ch, NULL, NULL); 452 g_io_channel_set_buffered(in_ch, false); 453 g_io_channel_set_flags(in_ch, G_IO_FLAG_NONBLOCK, NULL); 454 g_io_channel_set_close_on_unref(in_ch, true); 455 g_io_add_watch(in_ch, G_IO_OUT, guest_exec_input_watch, &gei->in); 456 } 457 458 if (has_output) { 459 #ifdef G_OS_WIN32 460 out_ch = g_io_channel_win32_new_fd(out_fd); 461 err_ch = g_io_channel_win32_new_fd(err_fd); 462 #else 463 out_ch = g_io_channel_unix_new(out_fd); 464 err_ch = g_io_channel_unix_new(err_fd); 465 #endif 466 g_io_channel_set_encoding(out_ch, NULL, NULL); 467 g_io_channel_set_encoding(err_ch, NULL, NULL); 468 g_io_channel_set_buffered(out_ch, false); 469 g_io_channel_set_buffered(err_ch, false); 470 g_io_channel_set_close_on_unref(out_ch, true); 471 g_io_channel_set_close_on_unref(err_ch, true); 472 g_io_add_watch(out_ch, G_IO_IN | G_IO_HUP, 473 guest_exec_output_watch, &gei->out); 474 g_io_add_watch(err_ch, G_IO_IN | G_IO_HUP, 475 guest_exec_output_watch, &gei->err); 476 } 477 478 done: 479 g_free(argv); 480 g_free(envp); 481 482 return ge; 483 } 484 485 /* Convert GuestFileWhence (either a raw integer or an enum value) into 486 * the guest's SEEK_ constants. */ 487 int ga_parse_whence(GuestFileWhence *whence, Error **errp) 488 { 489 /* 490 * Exploit the fact that we picked values to match QGA_SEEK_*; 491 * however, we have to use a temporary variable since the union 492 * members may have different size. 493 */ 494 if (whence->type == QTYPE_QSTRING) { 495 int value = whence->u.name; 496 whence->type = QTYPE_QNUM; 497 whence->u.value = value; 498 } 499 switch (whence->u.value) { 500 case QGA_SEEK_SET: 501 return SEEK_SET; 502 case QGA_SEEK_CUR: 503 return SEEK_CUR; 504 case QGA_SEEK_END: 505 return SEEK_END; 506 } 507 error_setg(errp, "invalid whence code %"PRId64, whence->u.value); 508 return -1; 509 } 510 511 GuestHostName *qmp_guest_get_host_name(Error **errp) 512 { 513 GuestHostName *result = NULL; 514 g_autofree char *hostname = qemu_get_host_name(errp); 515 516 /* 517 * We want to avoid using g_get_host_name() because that 518 * caches the result and we wouldn't reflect changes in the 519 * host name. 520 */ 521 522 if (!hostname) { 523 hostname = g_strdup("localhost"); 524 } 525 526 result = g_new0(GuestHostName, 1); 527 result->host_name = g_steal_pointer(&hostname); 528 return result; 529 } 530 531 GuestTimezone *qmp_guest_get_timezone(Error **errp) 532 { 533 GuestTimezone *info = NULL; 534 GTimeZone *tz = NULL; 535 gint64 now = 0; 536 gint32 intv = 0; 537 gchar const *name = NULL; 538 539 info = g_new0(GuestTimezone, 1); 540 tz = g_time_zone_new_local(); 541 if (tz == NULL) { 542 error_setg(errp, QERR_QGA_COMMAND_FAILED, 543 "Couldn't retrieve local timezone"); 544 goto error; 545 } 546 547 now = g_get_real_time() / G_USEC_PER_SEC; 548 intv = g_time_zone_find_interval(tz, G_TIME_TYPE_UNIVERSAL, now); 549 info->offset = g_time_zone_get_offset(tz, intv); 550 name = g_time_zone_get_abbreviation(tz, intv); 551 if (name != NULL) { 552 info->has_zone = true; 553 info->zone = g_strdup(name); 554 } 555 g_time_zone_unref(tz); 556 557 return info; 558 559 error: 560 g_free(info); 561 return NULL; 562 } 563 564 GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count, 565 int64_t count, Error **errp) 566 { 567 GuestFileHandle *gfh = guest_file_handle_find(handle, errp); 568 GuestFileRead *read_data; 569 570 if (!gfh) { 571 return NULL; 572 } 573 if (!has_count) { 574 count = QGA_READ_COUNT_DEFAULT; 575 } else if (count < 0 || count > GUEST_FILE_READ_COUNT_MAX) { 576 error_setg(errp, "value '%" PRId64 "' is invalid for argument count", 577 count); 578 return NULL; 579 } 580 581 read_data = guest_file_read_unsafe(gfh, count, errp); 582 if (!read_data) { 583 slog("guest-file-write failed, handle: %" PRId64, handle); 584 } 585 586 return read_data; 587 } 588