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