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 "commands-common.h" 22 23 /* Maximum captured guest-exec out_data/err_data - 16MB */ 24 #define GUEST_EXEC_MAX_OUTPUT (16 * 1024 * 1024) 25 /* Allocation and I/O buffer for reading guest-exec out_data/err_data - 4KB */ 26 #define GUEST_EXEC_IO_SIZE (4 * 1024) 27 /* 28 * Maximum file size to read - 48MB 29 * 30 * (48MB + Base64 3:4 overhead = JSON parser 64 MB limit) 31 */ 32 #define GUEST_FILE_READ_COUNT_MAX (48 * MiB) 33 34 /* Note: in some situations, like with the fsfreeze, logging may be 35 * temporarily disabled. if it is necessary that a command be able 36 * to log for accounting purposes, check ga_logging_enabled() beforehand. 37 */ 38 void slog(const gchar *fmt, ...) 39 { 40 va_list ap; 41 42 va_start(ap, fmt); 43 g_logv("syslog", G_LOG_LEVEL_INFO, fmt, ap); 44 va_end(ap); 45 } 46 47 int64_t qmp_guest_sync_delimited(int64_t id, Error **errp) 48 { 49 ga_set_response_delimited(ga_state); 50 return id; 51 } 52 53 int64_t qmp_guest_sync(int64_t id, Error **errp) 54 { 55 return id; 56 } 57 58 void qmp_guest_ping(Error **errp) 59 { 60 slog("guest-ping called"); 61 } 62 63 static void qmp_command_info(const QmpCommand *cmd, void *opaque) 64 { 65 GuestAgentInfo *info = opaque; 66 GuestAgentCommandInfo *cmd_info; 67 68 cmd_info = g_new0(GuestAgentCommandInfo, 1); 69 cmd_info->name = g_strdup(qmp_command_name(cmd)); 70 cmd_info->enabled = qmp_command_is_enabled(cmd); 71 cmd_info->success_response = qmp_has_success_response(cmd); 72 73 QAPI_LIST_PREPEND(info->supported_commands, cmd_info); 74 } 75 76 struct GuestAgentInfo *qmp_guest_info(Error **errp) 77 { 78 GuestAgentInfo *info = g_new0(GuestAgentInfo, 1); 79 80 info->version = g_strdup(QEMU_VERSION); 81 qmp_for_each_command(&ga_commands, qmp_command_info, info); 82 return info; 83 } 84 85 struct GuestExecIOData { 86 guchar *data; 87 gsize size; 88 gsize length; 89 bool closed; 90 bool truncated; 91 const char *name; 92 }; 93 typedef struct GuestExecIOData GuestExecIOData; 94 95 struct GuestExecInfo { 96 GPid pid; 97 int64_t pid_numeric; 98 gint status; 99 bool has_output; 100 bool finished; 101 GuestExecIOData in; 102 GuestExecIOData out; 103 GuestExecIOData err; 104 QTAILQ_ENTRY(GuestExecInfo) next; 105 }; 106 typedef struct GuestExecInfo GuestExecInfo; 107 108 static struct { 109 QTAILQ_HEAD(, GuestExecInfo) processes; 110 } guest_exec_state = { 111 .processes = QTAILQ_HEAD_INITIALIZER(guest_exec_state.processes), 112 }; 113 114 static int64_t gpid_to_int64(GPid pid) 115 { 116 #ifdef G_OS_WIN32 117 return GetProcessId(pid); 118 #else 119 return (int64_t)pid; 120 #endif 121 } 122 123 static GuestExecInfo *guest_exec_info_add(GPid pid) 124 { 125 GuestExecInfo *gei; 126 127 gei = g_new0(GuestExecInfo, 1); 128 gei->pid = pid; 129 gei->pid_numeric = gpid_to_int64(pid); 130 QTAILQ_INSERT_TAIL(&guest_exec_state.processes, gei, next); 131 132 return gei; 133 } 134 135 static GuestExecInfo *guest_exec_info_find(int64_t pid_numeric) 136 { 137 GuestExecInfo *gei; 138 139 QTAILQ_FOREACH(gei, &guest_exec_state.processes, next) { 140 if (gei->pid_numeric == pid_numeric) { 141 return gei; 142 } 143 } 144 145 return NULL; 146 } 147 148 GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **errp) 149 { 150 GuestExecInfo *gei; 151 GuestExecStatus *ges; 152 153 slog("guest-exec-status called, pid: %u", (uint32_t)pid); 154 155 gei = guest_exec_info_find(pid); 156 if (gei == NULL) { 157 error_setg(errp, "PID " PRId64 " does not exist"); 158 return NULL; 159 } 160 161 ges = g_new0(GuestExecStatus, 1); 162 163 bool finished = gei->finished; 164 165 /* need to wait till output channels are closed 166 * to be sure we captured all output at this point */ 167 if (gei->has_output) { 168 finished &= gei->out.closed && gei->err.closed; 169 } 170 171 ges->exited = finished; 172 if (finished) { 173 /* Glib has no portable way to parse exit status. 174 * On UNIX, we can get either exit code from normal termination 175 * or signal number. 176 * On Windows, it is either the same exit code or the exception 177 * value for an unhandled exception that caused the process 178 * to terminate. 179 * See MSDN for GetExitCodeProcess() and ntstatus.h for possible 180 * well-known codes, e.g. C0000005 ACCESS_DENIED - analog of SIGSEGV 181 * References: 182 * https://msdn.microsoft.com/en-us/library/windows/desktop/ms683189(v=vs.85).aspx 183 * https://msdn.microsoft.com/en-us/library/aa260331(v=vs.60).aspx 184 */ 185 #ifdef G_OS_WIN32 186 /* Additionally WIN32 does not provide any additional information 187 * on whether the child exited or terminated via signal. 188 * We use this simple range check to distinguish application exit code 189 * (usually value less then 256) and unhandled exception code with 190 * ntstatus (always value greater then 0xC0000005). */ 191 if ((uint32_t)gei->status < 0xC0000000U) { 192 ges->has_exitcode = true; 193 ges->exitcode = gei->status; 194 } else { 195 ges->has_signal = true; 196 ges->signal = gei->status; 197 } 198 #else 199 if (WIFEXITED(gei->status)) { 200 ges->has_exitcode = true; 201 ges->exitcode = WEXITSTATUS(gei->status); 202 } else if (WIFSIGNALED(gei->status)) { 203 ges->has_signal = true; 204 ges->signal = WTERMSIG(gei->status); 205 } 206 #endif 207 if (gei->out.length > 0) { 208 ges->out_data = g_base64_encode(gei->out.data, gei->out.length); 209 ges->has_out_truncated = gei->out.truncated; 210 } 211 g_free(gei->out.data); 212 213 if (gei->err.length > 0) { 214 ges->err_data = g_base64_encode(gei->err.data, gei->err.length); 215 ges->has_err_truncated = gei->err.truncated; 216 } 217 g_free(gei->err.data); 218 219 QTAILQ_REMOVE(&guest_exec_state.processes, gei, next); 220 g_free(gei); 221 } 222 223 return ges; 224 } 225 226 /* Get environment variables or arguments array for execve(). */ 227 static char **guest_exec_get_args(const strList *entry, bool log) 228 { 229 const strList *it; 230 int count = 1, i = 0; /* reserve for NULL terminator */ 231 char **args; 232 char *str; /* for logging array of arguments */ 233 size_t str_size = 1; 234 235 for (it = entry; it != NULL; it = it->next) { 236 count++; 237 str_size += 1 + strlen(it->value); 238 } 239 240 str = g_malloc(str_size); 241 *str = 0; 242 args = g_new(char *, count); 243 for (it = entry; it != NULL; it = it->next) { 244 args[i++] = it->value; 245 pstrcat(str, str_size, it->value); 246 if (it->next) { 247 pstrcat(str, str_size, " "); 248 } 249 } 250 args[i] = NULL; 251 252 if (log) { 253 slog("guest-exec called: \"%s\"", str); 254 } 255 g_free(str); 256 257 return args; 258 } 259 260 static void guest_exec_child_watch(GPid pid, gint status, gpointer data) 261 { 262 GuestExecInfo *gei = (GuestExecInfo *)data; 263 264 g_debug("guest_exec_child_watch called, pid: %d, status: %u", 265 (int32_t)gpid_to_int64(pid), (uint32_t)status); 266 267 gei->status = status; 268 gei->finished = true; 269 270 g_spawn_close_pid(pid); 271 } 272 273 static void guest_exec_task_setup(gpointer data) 274 { 275 #if !defined(G_OS_WIN32) 276 bool has_merge = *(bool *)data; 277 struct sigaction sigact; 278 279 if (has_merge) { 280 /* 281 * FIXME: When `GLIB_VERSION_MIN_REQUIRED` is bumped to 2.58+, use 282 * g_spawn_async_with_fds() to be portable on windows. The current 283 * logic does not work on windows b/c `GSpawnChildSetupFunc` is run 284 * inside the parent, not the child. 285 */ 286 if (dup2(STDOUT_FILENO, STDERR_FILENO) != 0) { 287 slog("dup2() failed to merge stderr into stdout: %s", 288 strerror(errno)); 289 } 290 } 291 292 /* Reset ignored signals back to default. */ 293 memset(&sigact, 0, sizeof(struct sigaction)); 294 sigact.sa_handler = SIG_DFL; 295 296 if (sigaction(SIGPIPE, &sigact, NULL) != 0) { 297 slog("sigaction() failed to reset child process's SIGPIPE: %s", 298 strerror(errno)); 299 } 300 #endif 301 } 302 303 static gboolean guest_exec_input_watch(GIOChannel *ch, 304 GIOCondition cond, gpointer p_) 305 { 306 GuestExecIOData *p = (GuestExecIOData *)p_; 307 gsize bytes_written = 0; 308 GIOStatus status; 309 GError *gerr = NULL; 310 311 /* nothing left to write */ 312 if (p->size == p->length) { 313 goto done; 314 } 315 316 status = g_io_channel_write_chars(ch, (gchar *)p->data + p->length, 317 p->size - p->length, &bytes_written, &gerr); 318 319 /* can be not 0 even if not G_IO_STATUS_NORMAL */ 320 if (bytes_written != 0) { 321 p->length += bytes_written; 322 } 323 324 /* continue write, our callback will be called again */ 325 if (status == G_IO_STATUS_NORMAL || status == G_IO_STATUS_AGAIN) { 326 return true; 327 } 328 329 if (gerr) { 330 g_warning("qga: i/o error writing to input_data channel: %s", 331 gerr->message); 332 g_error_free(gerr); 333 } 334 335 done: 336 g_io_channel_shutdown(ch, true, NULL); 337 g_io_channel_unref(ch); 338 p->closed = true; 339 g_free(p->data); 340 341 return false; 342 } 343 344 static gboolean guest_exec_output_watch(GIOChannel *ch, 345 GIOCondition cond, gpointer p_) 346 { 347 GuestExecIOData *p = (GuestExecIOData *)p_; 348 gsize bytes_read; 349 GIOStatus gstatus; 350 351 if (cond == G_IO_HUP || cond == G_IO_ERR) { 352 goto close; 353 } 354 355 if (p->size == p->length) { 356 gpointer t = NULL; 357 if (!p->truncated && p->size < GUEST_EXEC_MAX_OUTPUT) { 358 t = g_try_realloc(p->data, p->size + GUEST_EXEC_IO_SIZE); 359 } 360 if (t == NULL) { 361 /* ignore truncated output */ 362 gchar buf[GUEST_EXEC_IO_SIZE]; 363 364 p->truncated = true; 365 gstatus = g_io_channel_read_chars(ch, buf, sizeof(buf), 366 &bytes_read, NULL); 367 if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) { 368 goto close; 369 } 370 371 return true; 372 } 373 p->size += GUEST_EXEC_IO_SIZE; 374 p->data = t; 375 } 376 377 /* Calling read API once. 378 * On next available data our callback will be called again */ 379 gstatus = g_io_channel_read_chars(ch, (gchar *)p->data + p->length, 380 p->size - p->length, &bytes_read, NULL); 381 if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) { 382 goto close; 383 } 384 385 p->length += bytes_read; 386 387 return true; 388 389 close: 390 g_io_channel_shutdown(ch, true, NULL); 391 g_io_channel_unref(ch); 392 p->closed = true; 393 return false; 394 } 395 396 static GuestExecCaptureOutputMode ga_parse_capture_output( 397 GuestExecCaptureOutput *capture_output) 398 { 399 if (!capture_output) 400 return GUEST_EXEC_CAPTURE_OUTPUT_MODE_NONE; 401 else if (capture_output->type == QTYPE_QBOOL) 402 return capture_output->u.flag ? GUEST_EXEC_CAPTURE_OUTPUT_MODE_SEPARATED 403 : GUEST_EXEC_CAPTURE_OUTPUT_MODE_NONE; 404 else 405 return capture_output->u.mode; 406 } 407 408 GuestExec *qmp_guest_exec(const char *path, 409 bool has_arg, strList *arg, 410 bool has_env, strList *env, 411 const char *input_data, 412 GuestExecCaptureOutput *capture_output, 413 Error **errp) 414 { 415 GPid pid; 416 GuestExec *ge = NULL; 417 GuestExecInfo *gei; 418 char **argv, **envp; 419 strList arglist; 420 gboolean ret; 421 GError *gerr = NULL; 422 gint in_fd, out_fd, err_fd; 423 GIOChannel *in_ch, *out_ch, *err_ch; 424 GSpawnFlags flags; 425 bool has_output = false; 426 bool has_merge = false; 427 GuestExecCaptureOutputMode output_mode; 428 g_autofree uint8_t *input = NULL; 429 size_t ninput = 0; 430 431 arglist.value = (char *)path; 432 arglist.next = has_arg ? arg : NULL; 433 434 if (input_data) { 435 input = qbase64_decode(input_data, -1, &ninput, errp); 436 if (!input) { 437 return NULL; 438 } 439 } 440 441 argv = guest_exec_get_args(&arglist, true); 442 envp = has_env ? guest_exec_get_args(env, false) : NULL; 443 444 flags = G_SPAWN_SEARCH_PATH | G_SPAWN_DO_NOT_REAP_CHILD | 445 G_SPAWN_SEARCH_PATH_FROM_ENVP; 446 447 output_mode = ga_parse_capture_output(capture_output); 448 switch (output_mode) { 449 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_NONE: 450 flags |= G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL; 451 break; 452 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_STDOUT: 453 has_output = true; 454 flags |= G_SPAWN_STDERR_TO_DEV_NULL; 455 break; 456 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_STDERR: 457 has_output = true; 458 flags |= G_SPAWN_STDOUT_TO_DEV_NULL; 459 break; 460 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_SEPARATED: 461 has_output = true; 462 break; 463 #if !defined(G_OS_WIN32) 464 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_MERGED: 465 has_output = true; 466 has_merge = true; 467 break; 468 #endif 469 case GUEST_EXEC_CAPTURE_OUTPUT_MODE__MAX: 470 /* Silence warning; impossible branch */ 471 break; 472 } 473 474 ret = g_spawn_async_with_pipes(NULL, argv, envp, flags, 475 guest_exec_task_setup, &has_merge, &pid, input_data ? &in_fd : NULL, 476 has_output ? &out_fd : NULL, has_output ? &err_fd : NULL, &gerr); 477 if (!ret) { 478 error_setg(errp, QERR_QGA_COMMAND_FAILED, gerr->message); 479 g_error_free(gerr); 480 goto done; 481 } 482 483 ge = g_new0(GuestExec, 1); 484 ge->pid = gpid_to_int64(pid); 485 486 gei = guest_exec_info_add(pid); 487 gei->has_output = has_output; 488 g_child_watch_add(pid, guest_exec_child_watch, gei); 489 490 if (input_data) { 491 gei->in.data = g_steal_pointer(&input); 492 gei->in.size = ninput; 493 #ifdef G_OS_WIN32 494 in_ch = g_io_channel_win32_new_fd(in_fd); 495 #else 496 in_ch = g_io_channel_unix_new(in_fd); 497 #endif 498 g_io_channel_set_encoding(in_ch, NULL, NULL); 499 g_io_channel_set_buffered(in_ch, false); 500 g_io_channel_set_flags(in_ch, G_IO_FLAG_NONBLOCK, NULL); 501 g_io_channel_set_close_on_unref(in_ch, true); 502 g_io_add_watch(in_ch, G_IO_OUT, guest_exec_input_watch, &gei->in); 503 } 504 505 if (has_output) { 506 #ifdef G_OS_WIN32 507 out_ch = g_io_channel_win32_new_fd(out_fd); 508 err_ch = g_io_channel_win32_new_fd(err_fd); 509 #else 510 out_ch = g_io_channel_unix_new(out_fd); 511 err_ch = g_io_channel_unix_new(err_fd); 512 #endif 513 g_io_channel_set_encoding(out_ch, NULL, NULL); 514 g_io_channel_set_encoding(err_ch, NULL, NULL); 515 g_io_channel_set_buffered(out_ch, false); 516 g_io_channel_set_buffered(err_ch, false); 517 g_io_channel_set_close_on_unref(out_ch, true); 518 g_io_channel_set_close_on_unref(err_ch, true); 519 g_io_add_watch(out_ch, G_IO_IN | G_IO_HUP, 520 guest_exec_output_watch, &gei->out); 521 g_io_add_watch(err_ch, G_IO_IN | G_IO_HUP, 522 guest_exec_output_watch, &gei->err); 523 } 524 525 done: 526 g_free(argv); 527 g_free(envp); 528 529 return ge; 530 } 531 532 /* Convert GuestFileWhence (either a raw integer or an enum value) into 533 * the guest's SEEK_ constants. */ 534 int ga_parse_whence(GuestFileWhence *whence, Error **errp) 535 { 536 /* 537 * Exploit the fact that we picked values to match QGA_SEEK_*; 538 * however, we have to use a temporary variable since the union 539 * members may have different size. 540 */ 541 if (whence->type == QTYPE_QSTRING) { 542 int value = whence->u.name; 543 whence->type = QTYPE_QNUM; 544 whence->u.value = value; 545 } 546 switch (whence->u.value) { 547 case QGA_SEEK_SET: 548 return SEEK_SET; 549 case QGA_SEEK_CUR: 550 return SEEK_CUR; 551 case QGA_SEEK_END: 552 return SEEK_END; 553 } 554 error_setg(errp, "invalid whence code %"PRId64, whence->u.value); 555 return -1; 556 } 557 558 GuestHostName *qmp_guest_get_host_name(Error **errp) 559 { 560 GuestHostName *result = NULL; 561 g_autofree char *hostname = qga_get_host_name(errp); 562 563 /* 564 * We want to avoid using g_get_host_name() because that 565 * caches the result and we wouldn't reflect changes in the 566 * host name. 567 */ 568 569 if (!hostname) { 570 hostname = g_strdup("localhost"); 571 } 572 573 result = g_new0(GuestHostName, 1); 574 result->host_name = g_steal_pointer(&hostname); 575 return result; 576 } 577 578 GuestTimezone *qmp_guest_get_timezone(Error **errp) 579 { 580 GuestTimezone *info = NULL; 581 GTimeZone *tz = NULL; 582 gint64 now = 0; 583 gint32 intv = 0; 584 gchar const *name = NULL; 585 586 info = g_new0(GuestTimezone, 1); 587 tz = g_time_zone_new_local(); 588 if (tz == NULL) { 589 error_setg(errp, QERR_QGA_COMMAND_FAILED, 590 "Couldn't retrieve local timezone"); 591 goto error; 592 } 593 594 now = g_get_real_time() / G_USEC_PER_SEC; 595 intv = g_time_zone_find_interval(tz, G_TIME_TYPE_UNIVERSAL, now); 596 info->offset = g_time_zone_get_offset(tz, intv); 597 name = g_time_zone_get_abbreviation(tz, intv); 598 if (name != NULL) { 599 info->zone = g_strdup(name); 600 } 601 g_time_zone_unref(tz); 602 603 return info; 604 605 error: 606 g_free(info); 607 return NULL; 608 } 609 610 GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count, 611 int64_t count, Error **errp) 612 { 613 GuestFileHandle *gfh = guest_file_handle_find(handle, errp); 614 GuestFileRead *read_data; 615 616 if (!gfh) { 617 return NULL; 618 } 619 if (!has_count) { 620 count = QGA_READ_COUNT_DEFAULT; 621 } else if (count < 0 || count > GUEST_FILE_READ_COUNT_MAX) { 622 error_setg(errp, "value '%" PRId64 "' is invalid for argument count", 623 count); 624 return NULL; 625 } 626 627 read_data = guest_file_read_unsafe(gfh, count, errp); 628 if (!read_data) { 629 slog("guest-file-write failed, handle: %" PRId64, handle); 630 } 631 632 return read_data; 633 } 634 635 int64_t qmp_guest_get_time(Error **errp) 636 { 637 return g_get_real_time() * 1000; 638 } 639