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 "qga/guest-agent-core.h" 15 #include "qga-qapi-commands.h" 16 #include "qapi/error.h" 17 #include "qapi/qmp/qerror.h" 18 #include "qemu/base64.h" 19 #include "qemu/cutils.h" 20 #include "qemu/atomic.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 /* Note: in some situations, like with the fsfreeze, logging may be 28 * temporarilly disabled. if it is necessary that a command be able 29 * to log for accounting purposes, check ga_logging_enabled() beforehand, 30 * and use the QERR_QGA_LOGGING_DISABLED to generate an error 31 */ 32 void slog(const gchar *fmt, ...) 33 { 34 va_list ap; 35 36 va_start(ap, fmt); 37 g_logv("syslog", G_LOG_LEVEL_INFO, fmt, ap); 38 va_end(ap); 39 } 40 41 int64_t qmp_guest_sync_delimited(int64_t id, Error **errp) 42 { 43 ga_set_response_delimited(ga_state); 44 return id; 45 } 46 47 int64_t qmp_guest_sync(int64_t id, Error **errp) 48 { 49 return id; 50 } 51 52 void qmp_guest_ping(Error **errp) 53 { 54 slog("guest-ping called"); 55 } 56 57 static void qmp_command_info(QmpCommand *cmd, void *opaque) 58 { 59 GuestAgentInfo *info = opaque; 60 GuestAgentCommandInfo *cmd_info; 61 GuestAgentCommandInfoList *cmd_info_list; 62 63 cmd_info = g_new0(GuestAgentCommandInfo, 1); 64 cmd_info->name = g_strdup(qmp_command_name(cmd)); 65 cmd_info->enabled = qmp_command_is_enabled(cmd); 66 cmd_info->success_response = qmp_has_success_response(cmd); 67 68 cmd_info_list = g_new0(GuestAgentCommandInfoList, 1); 69 cmd_info_list->value = cmd_info; 70 cmd_info_list->next = info->supported_commands; 71 info->supported_commands = cmd_info_list; 72 } 73 74 struct GuestAgentInfo *qmp_guest_info(Error **errp) 75 { 76 GuestAgentInfo *info = g_new0(GuestAgentInfo, 1); 77 78 info->version = g_strdup(QEMU_VERSION); 79 qmp_for_each_command(&ga_commands, qmp_command_info, info); 80 return info; 81 } 82 83 struct GuestExecIOData { 84 guchar *data; 85 gsize size; 86 gsize length; 87 bool closed; 88 bool truncated; 89 const char *name; 90 }; 91 typedef struct GuestExecIOData GuestExecIOData; 92 93 struct GuestExecInfo { 94 GPid pid; 95 int64_t pid_numeric; 96 gint status; 97 bool has_output; 98 bool finished; 99 GuestExecIOData in; 100 GuestExecIOData out; 101 GuestExecIOData err; 102 QTAILQ_ENTRY(GuestExecInfo) next; 103 }; 104 typedef struct GuestExecInfo GuestExecInfo; 105 106 static struct { 107 QTAILQ_HEAD(, GuestExecInfo) processes; 108 } guest_exec_state = { 109 .processes = QTAILQ_HEAD_INITIALIZER(guest_exec_state.processes), 110 }; 111 112 static int64_t gpid_to_int64(GPid pid) 113 { 114 #ifdef G_OS_WIN32 115 return GetProcessId(pid); 116 #else 117 return (int64_t)pid; 118 #endif 119 } 120 121 static GuestExecInfo *guest_exec_info_add(GPid pid) 122 { 123 GuestExecInfo *gei; 124 125 gei = g_new0(GuestExecInfo, 1); 126 gei->pid = pid; 127 gei->pid_numeric = gpid_to_int64(pid); 128 QTAILQ_INSERT_TAIL(&guest_exec_state.processes, gei, next); 129 130 return gei; 131 } 132 133 static GuestExecInfo *guest_exec_info_find(int64_t pid_numeric) 134 { 135 GuestExecInfo *gei; 136 137 QTAILQ_FOREACH(gei, &guest_exec_state.processes, next) { 138 if (gei->pid_numeric == pid_numeric) { 139 return gei; 140 } 141 } 142 143 return NULL; 144 } 145 146 GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **err) 147 { 148 GuestExecInfo *gei; 149 GuestExecStatus *ges; 150 151 slog("guest-exec-status called, pid: %u", (uint32_t)pid); 152 153 gei = guest_exec_info_find(pid); 154 if (gei == NULL) { 155 error_setg(err, QERR_INVALID_PARAMETER, "pid"); 156 return NULL; 157 } 158 159 ges = g_new0(GuestExecStatus, 1); 160 161 bool finished = atomic_mb_read(&gei->finished); 162 163 /* need to wait till output channels are closed 164 * to be sure we captured all output at this point */ 165 if (gei->has_output) { 166 finished = finished && atomic_mb_read(&gei->out.closed); 167 finished = finished && atomic_mb_read(&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->has_out_data = true; 208 ges->out_data = g_base64_encode(gei->out.data, gei->out.length); 209 g_free(gei->out.data); 210 ges->has_out_truncated = gei->out.truncated; 211 } 212 213 if (gei->err.length > 0) { 214 ges->has_err_data = true; 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_malloc(count * sizeof(char *)); 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 atomic_mb_set(&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 atomic_mb_set(&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 atomic_mb_set(&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 bool has_input_data, const char *input_data, 387 bool has_capture_output, bool capture_output, 388 Error **err) 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 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 (has_input_data) { 408 input = qbase64_decode(input_data, -1, &ninput, err); 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 #if GLIB_CHECK_VERSION(2, 33, 2) 419 flags |= G_SPAWN_SEARCH_PATH_FROM_ENVP; 420 #endif 421 if (!has_output) { 422 flags |= G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL; 423 } 424 425 ret = g_spawn_async_with_pipes(NULL, argv, envp, flags, 426 guest_exec_task_setup, NULL, &pid, has_input_data ? &in_fd : NULL, 427 has_output ? &out_fd : NULL, has_output ? &err_fd : NULL, &gerr); 428 if (!ret) { 429 error_setg(err, QERR_QGA_COMMAND_FAILED, gerr->message); 430 g_error_free(gerr); 431 goto done; 432 } 433 434 ge = g_new0(GuestExec, 1); 435 ge->pid = gpid_to_int64(pid); 436 437 gei = guest_exec_info_add(pid); 438 gei->has_output = has_output; 439 g_child_watch_add(pid, guest_exec_child_watch, gei); 440 441 if (has_input_data) { 442 gei->in.data = input; 443 gei->in.size = ninput; 444 #ifdef G_OS_WIN32 445 in_ch = g_io_channel_win32_new_fd(in_fd); 446 #else 447 in_ch = g_io_channel_unix_new(in_fd); 448 #endif 449 g_io_channel_set_encoding(in_ch, NULL, NULL); 450 g_io_channel_set_buffered(in_ch, false); 451 g_io_channel_set_flags(in_ch, G_IO_FLAG_NONBLOCK, NULL); 452 g_io_channel_set_close_on_unref(in_ch, true); 453 g_io_add_watch(in_ch, G_IO_OUT, guest_exec_input_watch, &gei->in); 454 } 455 456 if (has_output) { 457 #ifdef G_OS_WIN32 458 out_ch = g_io_channel_win32_new_fd(out_fd); 459 err_ch = g_io_channel_win32_new_fd(err_fd); 460 #else 461 out_ch = g_io_channel_unix_new(out_fd); 462 err_ch = g_io_channel_unix_new(err_fd); 463 #endif 464 g_io_channel_set_encoding(out_ch, NULL, NULL); 465 g_io_channel_set_encoding(err_ch, NULL, NULL); 466 g_io_channel_set_buffered(out_ch, false); 467 g_io_channel_set_buffered(err_ch, false); 468 g_io_channel_set_close_on_unref(out_ch, true); 469 g_io_channel_set_close_on_unref(err_ch, true); 470 g_io_add_watch(out_ch, G_IO_IN | G_IO_HUP, 471 guest_exec_output_watch, &gei->out); 472 g_io_add_watch(err_ch, G_IO_IN | G_IO_HUP, 473 guest_exec_output_watch, &gei->err); 474 } 475 476 done: 477 g_free(argv); 478 g_free(envp); 479 480 return ge; 481 } 482 483 /* Convert GuestFileWhence (either a raw integer or an enum value) into 484 * the guest's SEEK_ constants. */ 485 int ga_parse_whence(GuestFileWhence *whence, Error **errp) 486 { 487 /* Exploit the fact that we picked values to match QGA_SEEK_*. */ 488 if (whence->type == QTYPE_QSTRING) { 489 whence->type = QTYPE_QNUM; 490 whence->u.value = whence->u.name; 491 } 492 switch (whence->u.value) { 493 case QGA_SEEK_SET: 494 return SEEK_SET; 495 case QGA_SEEK_CUR: 496 return SEEK_CUR; 497 case QGA_SEEK_END: 498 return SEEK_END; 499 } 500 error_setg(errp, "invalid whence code %"PRId64, whence->u.value); 501 return -1; 502 } 503 504 GuestHostName *qmp_guest_get_host_name(Error **err) 505 { 506 GuestHostName *result = NULL; 507 gchar const *hostname = g_get_host_name(); 508 if (hostname != NULL) { 509 result = g_new0(GuestHostName, 1); 510 result->host_name = g_strdup(hostname); 511 } 512 return result; 513 } 514 515 GuestTimezone *qmp_guest_get_timezone(Error **errp) 516 { 517 #if GLIB_CHECK_VERSION(2, 28, 0) 518 GuestTimezone *info = NULL; 519 GTimeZone *tz = NULL; 520 gint64 now = 0; 521 gint32 intv = 0; 522 gchar const *name = NULL; 523 524 info = g_new0(GuestTimezone, 1); 525 tz = g_time_zone_new_local(); 526 if (tz == NULL) { 527 error_setg(errp, QERR_QGA_COMMAND_FAILED, 528 "Couldn't retrieve local timezone"); 529 goto error; 530 } 531 532 now = g_get_real_time() / G_USEC_PER_SEC; 533 intv = g_time_zone_find_interval(tz, G_TIME_TYPE_UNIVERSAL, now); 534 info->offset = g_time_zone_get_offset(tz, intv); 535 name = g_time_zone_get_abbreviation(tz, intv); 536 if (name != NULL) { 537 info->has_zone = true; 538 info->zone = g_strdup(name); 539 } 540 g_time_zone_unref(tz); 541 542 return info; 543 544 error: 545 g_free(info); 546 return NULL; 547 #else 548 error_setg(errp, QERR_UNSUPPORTED); 549 return NULL; 550 #endif 551 } 552