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