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 "qemu/base64.h" 19 #include "qemu/cutils.h" 20 #include "commands-common.h" 21 22 /* Maximum captured guest-exec out_data/err_data - 16MB */ 23 #define GUEST_EXEC_MAX_OUTPUT (16 * 1024 * 1024) 24 /* Allocation and I/O buffer for reading guest-exec out_data/err_data - 4KB */ 25 #define GUEST_EXEC_IO_SIZE (4 * 1024) 26 /* 27 * Maximum file size to read - 48MB 28 * 29 * (48MB + Base64 3:4 overhead = JSON parser 64 MB limit) 30 */ 31 #define GUEST_FILE_READ_COUNT_MAX (48 * MiB) 32 33 /* Note: in some situations, like with the fsfreeze, logging may be 34 * temporarily disabled. if it is necessary that a command be able 35 * to log for accounting purposes, check ga_logging_enabled() beforehand. 36 */ 37 void slog(const gchar *fmt, ...) 38 { 39 va_list ap; 40 41 va_start(ap, fmt); 42 g_logv("syslog", G_LOG_LEVEL_INFO, fmt, ap); 43 va_end(ap); 44 } 45 46 int64_t qmp_guest_sync_delimited(int64_t id, Error **errp) 47 { 48 ga_set_response_delimited(ga_state); 49 return id; 50 } 51 52 int64_t qmp_guest_sync(int64_t id, Error **errp) 53 { 54 return id; 55 } 56 57 void qmp_guest_ping(Error **errp) 58 { 59 slog("guest-ping called"); 60 } 61 62 static void qmp_command_info(const QmpCommand *cmd, void *opaque) 63 { 64 GuestAgentInfo *info = opaque; 65 GuestAgentCommandInfo *cmd_info; 66 67 cmd_info = g_new0(GuestAgentCommandInfo, 1); 68 cmd_info->name = g_strdup(qmp_command_name(cmd)); 69 cmd_info->enabled = qmp_command_is_enabled(cmd); 70 cmd_info->success_response = qmp_has_success_response(cmd); 71 72 QAPI_LIST_PREPEND(info->supported_commands, cmd_info); 73 } 74 75 struct GuestAgentInfo *qmp_guest_info(Error **errp) 76 { 77 GuestAgentInfo *info = g_new0(GuestAgentInfo, 1); 78 79 info->version = g_strdup(QEMU_VERSION); 80 qmp_for_each_command(&ga_commands, qmp_command_info, info); 81 return info; 82 } 83 84 struct GuestExecIOData { 85 guchar *data; 86 gsize size; 87 gsize length; 88 bool closed; 89 bool truncated; 90 const char *name; 91 }; 92 typedef struct GuestExecIOData GuestExecIOData; 93 94 struct GuestExecInfo { 95 GPid pid; 96 int64_t pid_numeric; 97 gint status; 98 bool has_output; 99 bool finished; 100 GuestExecIOData in; 101 GuestExecIOData out; 102 GuestExecIOData err; 103 QTAILQ_ENTRY(GuestExecInfo) next; 104 }; 105 typedef struct GuestExecInfo GuestExecInfo; 106 107 static struct { 108 QTAILQ_HEAD(, GuestExecInfo) processes; 109 } guest_exec_state = { 110 .processes = QTAILQ_HEAD_INITIALIZER(guest_exec_state.processes), 111 }; 112 113 static int64_t gpid_to_int64(GPid pid) 114 { 115 #ifdef G_OS_WIN32 116 return GetProcessId(pid); 117 #else 118 return (int64_t)pid; 119 #endif 120 } 121 122 static GuestExecInfo *guest_exec_info_add(GPid pid) 123 { 124 GuestExecInfo *gei; 125 126 gei = g_new0(GuestExecInfo, 1); 127 gei->pid = pid; 128 gei->pid_numeric = gpid_to_int64(pid); 129 QTAILQ_INSERT_TAIL(&guest_exec_state.processes, gei, next); 130 131 return gei; 132 } 133 134 static GuestExecInfo *guest_exec_info_find(int64_t pid_numeric) 135 { 136 GuestExecInfo *gei; 137 138 QTAILQ_FOREACH(gei, &guest_exec_state.processes, next) { 139 if (gei->pid_numeric == pid_numeric) { 140 return gei; 141 } 142 } 143 144 return NULL; 145 } 146 147 GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **errp) 148 { 149 GuestExecInfo *gei; 150 GuestExecStatus *ges; 151 152 slog("guest-exec-status called, pid: %u", (uint32_t)pid); 153 154 gei = guest_exec_info_find(pid); 155 if (gei == NULL) { 156 error_setg(errp, "PID " PRId64 " does not exist"); 157 return NULL; 158 } 159 160 ges = g_new0(GuestExecStatus, 1); 161 162 bool finished = gei->finished; 163 164 /* need to wait till output channels are closed 165 * to be sure we captured all output at this point */ 166 if (gei->has_output) { 167 finished &= gei->out.closed && gei->err.closed; 168 } 169 170 ges->exited = finished; 171 if (finished) { 172 /* Glib has no portable way to parse exit status. 173 * On UNIX, we can get either exit code from normal termination 174 * or signal number. 175 * On Windows, it is either the same exit code or the exception 176 * value for an unhandled exception that caused the process 177 * to terminate. 178 * See MSDN for GetExitCodeProcess() and ntstatus.h for possible 179 * well-known codes, e.g. C0000005 ACCESS_DENIED - analog of SIGSEGV 180 * References: 181 * https://msdn.microsoft.com/en-us/library/windows/desktop/ms683189(v=vs.85).aspx 182 * https://msdn.microsoft.com/en-us/library/aa260331(v=vs.60).aspx 183 */ 184 #ifdef G_OS_WIN32 185 /* Additionally WIN32 does not provide any additional information 186 * on whether the child exited or terminated via signal. 187 * We use this simple range check to distinguish application exit code 188 * (usually value less then 256) and unhandled exception code with 189 * ntstatus (always value greater then 0xC0000005). */ 190 if ((uint32_t)gei->status < 0xC0000000U) { 191 ges->has_exitcode = true; 192 ges->exitcode = gei->status; 193 } else { 194 ges->has_signal = true; 195 ges->signal = gei->status; 196 } 197 #else 198 if (WIFEXITED(gei->status)) { 199 ges->has_exitcode = true; 200 ges->exitcode = WEXITSTATUS(gei->status); 201 } else if (WIFSIGNALED(gei->status)) { 202 ges->has_signal = true; 203 ges->signal = WTERMSIG(gei->status); 204 } 205 #endif 206 if (gei->out.length > 0) { 207 ges->out_data = g_base64_encode(gei->out.data, gei->out.length); 208 ges->has_out_truncated = gei->out.truncated; 209 } 210 g_free(gei->out.data); 211 212 if (gei->err.length > 0) { 213 ges->err_data = g_base64_encode(gei->err.data, gei->err.length); 214 ges->has_err_truncated = gei->err.truncated; 215 } 216 g_free(gei->err.data); 217 218 QTAILQ_REMOVE(&guest_exec_state.processes, gei, next); 219 g_free(gei); 220 } 221 222 return ges; 223 } 224 225 /* Get environment variables or arguments array for execve(). */ 226 static char **guest_exec_get_args(const strList *entry, bool log) 227 { 228 const strList *it; 229 int count = 1, i = 0; /* reserve for NULL terminator */ 230 char **args; 231 char *str; /* for logging array of arguments */ 232 size_t str_size = 1; 233 234 for (it = entry; it != NULL; it = it->next) { 235 count++; 236 str_size += 1 + strlen(it->value); 237 } 238 239 str = g_malloc(str_size); 240 *str = 0; 241 args = g_new(char *, count); 242 for (it = entry; it != NULL; it = it->next) { 243 args[i++] = it->value; 244 pstrcat(str, str_size, it->value); 245 if (it->next) { 246 pstrcat(str, str_size, " "); 247 } 248 } 249 args[i] = NULL; 250 251 if (log) { 252 slog("guest-exec called: \"%s\"", str); 253 } 254 g_free(str); 255 256 return args; 257 } 258 259 static void guest_exec_child_watch(GPid pid, gint status, gpointer data) 260 { 261 GuestExecInfo *gei = (GuestExecInfo *)data; 262 263 g_debug("guest_exec_child_watch called, pid: %d, status: %u", 264 (int32_t)gpid_to_int64(pid), (uint32_t)status); 265 266 gei->status = status; 267 gei->finished = true; 268 269 g_spawn_close_pid(pid); 270 } 271 272 static void guest_exec_task_setup(gpointer data) 273 { 274 #if !defined(G_OS_WIN32) 275 bool has_merge = *(bool *)data; 276 struct sigaction sigact; 277 278 if (has_merge) { 279 /* 280 * FIXME: When `GLIB_VERSION_MIN_REQUIRED` is bumped to 2.58+, use 281 * g_spawn_async_with_fds() to be portable on windows. The current 282 * logic does not work on windows b/c `GSpawnChildSetupFunc` is run 283 * inside the parent, not the child. 284 */ 285 if (dup2(STDOUT_FILENO, STDERR_FILENO) != 0) { 286 slog("dup2() failed to merge stderr into stdout: %s", 287 strerror(errno)); 288 } 289 } 290 291 /* Reset ignored signals back to default. */ 292 memset(&sigact, 0, sizeof(struct sigaction)); 293 sigact.sa_handler = SIG_DFL; 294 295 if (sigaction(SIGPIPE, &sigact, NULL) != 0) { 296 slog("sigaction() failed to reset child process's SIGPIPE: %s", 297 strerror(errno)); 298 } 299 #endif 300 } 301 302 static gboolean guest_exec_input_watch(GIOChannel *ch, 303 GIOCondition cond, gpointer p_) 304 { 305 GuestExecIOData *p = (GuestExecIOData *)p_; 306 gsize bytes_written = 0; 307 GIOStatus status; 308 GError *gerr = NULL; 309 310 /* nothing left to write */ 311 if (p->size == p->length) { 312 goto done; 313 } 314 315 status = g_io_channel_write_chars(ch, (gchar *)p->data + p->length, 316 p->size - p->length, &bytes_written, &gerr); 317 318 /* can be not 0 even if not G_IO_STATUS_NORMAL */ 319 if (bytes_written != 0) { 320 p->length += bytes_written; 321 } 322 323 /* continue write, our callback will be called again */ 324 if (status == G_IO_STATUS_NORMAL || status == G_IO_STATUS_AGAIN) { 325 return true; 326 } 327 328 if (gerr) { 329 g_warning("qga: i/o error writing to input_data channel: %s", 330 gerr->message); 331 g_error_free(gerr); 332 } 333 334 done: 335 g_io_channel_shutdown(ch, true, NULL); 336 g_io_channel_unref(ch); 337 p->closed = true; 338 g_free(p->data); 339 340 return false; 341 } 342 343 static gboolean guest_exec_output_watch(GIOChannel *ch, 344 GIOCondition cond, gpointer p_) 345 { 346 GuestExecIOData *p = (GuestExecIOData *)p_; 347 gsize bytes_read; 348 GIOStatus gstatus; 349 350 if (cond == G_IO_HUP || cond == G_IO_ERR) { 351 goto close; 352 } 353 354 if (p->size == p->length) { 355 gpointer t = NULL; 356 if (!p->truncated && p->size < GUEST_EXEC_MAX_OUTPUT) { 357 t = g_try_realloc(p->data, p->size + GUEST_EXEC_IO_SIZE); 358 } 359 if (t == NULL) { 360 /* ignore truncated output */ 361 gchar buf[GUEST_EXEC_IO_SIZE]; 362 363 p->truncated = true; 364 gstatus = g_io_channel_read_chars(ch, buf, sizeof(buf), 365 &bytes_read, NULL); 366 if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) { 367 goto close; 368 } 369 370 return true; 371 } 372 p->size += GUEST_EXEC_IO_SIZE; 373 p->data = t; 374 } 375 376 /* Calling read API once. 377 * On next available data our callback will be called again */ 378 gstatus = g_io_channel_read_chars(ch, (gchar *)p->data + p->length, 379 p->size - p->length, &bytes_read, NULL); 380 if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) { 381 goto close; 382 } 383 384 p->length += bytes_read; 385 386 return true; 387 388 close: 389 g_io_channel_shutdown(ch, true, NULL); 390 g_io_channel_unref(ch); 391 p->closed = true; 392 return false; 393 } 394 395 static GuestExecCaptureOutputMode ga_parse_capture_output( 396 GuestExecCaptureOutput *capture_output) 397 { 398 if (!capture_output) 399 return GUEST_EXEC_CAPTURE_OUTPUT_MODE_NONE; 400 else if (capture_output->type == QTYPE_QBOOL) 401 return capture_output->u.flag ? GUEST_EXEC_CAPTURE_OUTPUT_MODE_SEPARATED 402 : GUEST_EXEC_CAPTURE_OUTPUT_MODE_NONE; 403 else 404 return capture_output->u.mode; 405 } 406 407 GuestExec *qmp_guest_exec(const char *path, 408 bool has_arg, strList *arg, 409 bool has_env, strList *env, 410 const char *input_data, 411 GuestExecCaptureOutput *capture_output, 412 Error **errp) 413 { 414 GPid pid; 415 GuestExec *ge = NULL; 416 GuestExecInfo *gei; 417 char **argv, **envp; 418 strList arglist; 419 gboolean ret; 420 GError *gerr = NULL; 421 gint in_fd, out_fd, err_fd; 422 GIOChannel *in_ch, *out_ch, *err_ch; 423 GSpawnFlags flags; 424 bool has_output = false; 425 bool has_merge = false; 426 GuestExecCaptureOutputMode output_mode; 427 g_autofree uint8_t *input = NULL; 428 size_t ninput = 0; 429 430 arglist.value = (char *)path; 431 arglist.next = has_arg ? arg : NULL; 432 433 if (input_data) { 434 input = qbase64_decode(input_data, -1, &ninput, errp); 435 if (!input) { 436 return NULL; 437 } 438 } 439 440 argv = guest_exec_get_args(&arglist, true); 441 envp = has_env ? guest_exec_get_args(env, false) : NULL; 442 443 flags = G_SPAWN_SEARCH_PATH | G_SPAWN_DO_NOT_REAP_CHILD | 444 G_SPAWN_SEARCH_PATH_FROM_ENVP; 445 446 output_mode = ga_parse_capture_output(capture_output); 447 switch (output_mode) { 448 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_NONE: 449 flags |= G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL; 450 break; 451 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_STDOUT: 452 has_output = true; 453 flags |= G_SPAWN_STDERR_TO_DEV_NULL; 454 break; 455 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_STDERR: 456 has_output = true; 457 flags |= G_SPAWN_STDOUT_TO_DEV_NULL; 458 break; 459 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_SEPARATED: 460 has_output = true; 461 break; 462 #if !defined(G_OS_WIN32) 463 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_MERGED: 464 has_output = true; 465 has_merge = true; 466 break; 467 #endif 468 case GUEST_EXEC_CAPTURE_OUTPUT_MODE__MAX: 469 /* Silence warning; impossible branch */ 470 break; 471 } 472 473 ret = g_spawn_async_with_pipes(NULL, argv, envp, flags, 474 guest_exec_task_setup, &has_merge, &pid, input_data ? &in_fd : NULL, 475 has_output ? &out_fd : NULL, has_output ? &err_fd : NULL, &gerr); 476 if (!ret) { 477 error_setg(errp, "%s", gerr->message); 478 g_error_free(gerr); 479 goto done; 480 } 481 482 ge = g_new0(GuestExec, 1); 483 ge->pid = gpid_to_int64(pid); 484 485 gei = guest_exec_info_add(pid); 486 gei->has_output = has_output; 487 g_child_watch_add(pid, guest_exec_child_watch, gei); 488 489 if (input_data) { 490 gei->in.data = g_steal_pointer(&input); 491 gei->in.size = ninput; 492 #ifdef G_OS_WIN32 493 in_ch = g_io_channel_win32_new_fd(in_fd); 494 #else 495 in_ch = g_io_channel_unix_new(in_fd); 496 #endif 497 g_io_channel_set_encoding(in_ch, NULL, NULL); 498 g_io_channel_set_buffered(in_ch, false); 499 g_io_channel_set_flags(in_ch, G_IO_FLAG_NONBLOCK, NULL); 500 g_io_channel_set_close_on_unref(in_ch, true); 501 g_io_add_watch(in_ch, G_IO_OUT, guest_exec_input_watch, &gei->in); 502 } 503 504 if (has_output) { 505 #ifdef G_OS_WIN32 506 out_ch = g_io_channel_win32_new_fd(out_fd); 507 err_ch = g_io_channel_win32_new_fd(err_fd); 508 #else 509 out_ch = g_io_channel_unix_new(out_fd); 510 err_ch = g_io_channel_unix_new(err_fd); 511 #endif 512 g_io_channel_set_encoding(out_ch, NULL, NULL); 513 g_io_channel_set_encoding(err_ch, NULL, NULL); 514 g_io_channel_set_buffered(out_ch, false); 515 g_io_channel_set_buffered(err_ch, false); 516 g_io_channel_set_close_on_unref(out_ch, true); 517 g_io_channel_set_close_on_unref(err_ch, true); 518 g_io_add_watch(out_ch, G_IO_IN | G_IO_HUP, 519 guest_exec_output_watch, &gei->out); 520 g_io_add_watch(err_ch, G_IO_IN | G_IO_HUP, 521 guest_exec_output_watch, &gei->err); 522 } 523 524 done: 525 g_free(argv); 526 g_free(envp); 527 528 return ge; 529 } 530 531 /* Convert GuestFileWhence (either a raw integer or an enum value) into 532 * the guest's SEEK_ constants. */ 533 int ga_parse_whence(GuestFileWhence *whence, Error **errp) 534 { 535 /* 536 * Exploit the fact that we picked values to match QGA_SEEK_*; 537 * however, we have to use a temporary variable since the union 538 * members may have different size. 539 */ 540 if (whence->type == QTYPE_QSTRING) { 541 int value = whence->u.name; 542 whence->type = QTYPE_QNUM; 543 whence->u.value = value; 544 } 545 switch (whence->u.value) { 546 case QGA_SEEK_SET: 547 return SEEK_SET; 548 case QGA_SEEK_CUR: 549 return SEEK_CUR; 550 case QGA_SEEK_END: 551 return SEEK_END; 552 } 553 error_setg(errp, "invalid whence code %"PRId64, whence->u.value); 554 return -1; 555 } 556 557 GuestHostName *qmp_guest_get_host_name(Error **errp) 558 { 559 GuestHostName *result = NULL; 560 g_autofree char *hostname = qga_get_host_name(errp); 561 562 /* 563 * We want to avoid using g_get_host_name() because that 564 * caches the result and we wouldn't reflect changes in the 565 * host name. 566 */ 567 568 if (!hostname) { 569 hostname = g_strdup("localhost"); 570 } 571 572 result = g_new0(GuestHostName, 1); 573 result->host_name = g_steal_pointer(&hostname); 574 return result; 575 } 576 577 GuestTimezone *qmp_guest_get_timezone(Error **errp) 578 { 579 GuestTimezone *info = NULL; 580 GTimeZone *tz = NULL; 581 gint64 now = 0; 582 gint32 intv = 0; 583 gchar const *name = NULL; 584 585 info = g_new0(GuestTimezone, 1); 586 tz = g_time_zone_new_local(); 587 if (tz == NULL) { 588 error_setg(errp, "Couldn't retrieve local timezone"); 589 goto error; 590 } 591 592 now = g_get_real_time() / G_USEC_PER_SEC; 593 intv = g_time_zone_find_interval(tz, G_TIME_TYPE_UNIVERSAL, now); 594 info->offset = g_time_zone_get_offset(tz, intv); 595 name = g_time_zone_get_abbreviation(tz, intv); 596 if (name != NULL) { 597 info->zone = g_strdup(name); 598 } 599 g_time_zone_unref(tz); 600 601 return info; 602 603 error: 604 g_free(info); 605 return NULL; 606 } 607 608 GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count, 609 int64_t count, Error **errp) 610 { 611 GuestFileHandle *gfh = guest_file_handle_find(handle, errp); 612 GuestFileRead *read_data; 613 614 if (!gfh) { 615 return NULL; 616 } 617 if (!has_count) { 618 count = QGA_READ_COUNT_DEFAULT; 619 } else if (count < 0 || count > GUEST_FILE_READ_COUNT_MAX) { 620 error_setg(errp, "value '%" PRId64 "' is invalid for argument count", 621 count); 622 return NULL; 623 } 624 625 read_data = guest_file_read_unsafe(gfh, count, errp); 626 if (!read_data) { 627 slog("guest-file-write failed, handle: %" PRId64, handle); 628 } 629 630 return read_data; 631 } 632 633 int64_t qmp_guest_get_time(Error **errp) 634 { 635 return g_get_real_time() * 1000; 636 } 637