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 <glib.h> 15 #include "qga/guest-agent-core.h" 16 #include "qga-qmp-commands.h" 17 #include "qapi/qmp/qerror.h" 18 #include "qemu/base64.h" 19 20 /* Maximum captured guest-exec out_data/err_data - 16MB */ 21 #define GUEST_EXEC_MAX_OUTPUT (16*1024*1024) 22 /* Allocation and I/O buffer for reading guest-exec out_data/err_data - 4KB */ 23 #define GUEST_EXEC_IO_SIZE (4*1024) 24 25 /* Note: in some situations, like with the fsfreeze, logging may be 26 * temporarilly disabled. if it is necessary that a command be able 27 * to log for accounting purposes, check ga_logging_enabled() beforehand, 28 * and use the QERR_QGA_LOGGING_DISABLED to generate an error 29 */ 30 void slog(const gchar *fmt, ...) 31 { 32 va_list ap; 33 34 va_start(ap, fmt); 35 g_logv("syslog", G_LOG_LEVEL_INFO, fmt, ap); 36 va_end(ap); 37 } 38 39 int64_t qmp_guest_sync_delimited(int64_t id, Error **errp) 40 { 41 ga_set_response_delimited(ga_state); 42 return id; 43 } 44 45 int64_t qmp_guest_sync(int64_t id, Error **errp) 46 { 47 return id; 48 } 49 50 void qmp_guest_ping(Error **errp) 51 { 52 slog("guest-ping called"); 53 } 54 55 static void qmp_command_info(QmpCommand *cmd, void *opaque) 56 { 57 GuestAgentInfo *info = opaque; 58 GuestAgentCommandInfo *cmd_info; 59 GuestAgentCommandInfoList *cmd_info_list; 60 61 cmd_info = g_new0(GuestAgentCommandInfo, 1); 62 cmd_info->name = g_strdup(qmp_command_name(cmd)); 63 cmd_info->enabled = qmp_command_is_enabled(cmd); 64 cmd_info->success_response = qmp_has_success_response(cmd); 65 66 cmd_info_list = g_new0(GuestAgentCommandInfoList, 1); 67 cmd_info_list->value = cmd_info; 68 cmd_info_list->next = info->supported_commands; 69 info->supported_commands = cmd_info_list; 70 } 71 72 struct GuestAgentInfo *qmp_guest_info(Error **errp) 73 { 74 GuestAgentInfo *info = g_new0(GuestAgentInfo, 1); 75 76 info->version = g_strdup(QEMU_VERSION); 77 qmp_for_each_command(qmp_command_info, info); 78 return info; 79 } 80 81 struct GuestExecIOData { 82 guchar *data; 83 gsize size; 84 gsize length; 85 gint closed; 86 bool truncated; 87 const char *name; 88 }; 89 typedef struct GuestExecIOData GuestExecIOData; 90 91 struct GuestExecInfo { 92 GPid pid; 93 int64_t pid_numeric; 94 gint status; 95 bool has_output; 96 gint finished; 97 GuestExecIOData in; 98 GuestExecIOData out; 99 GuestExecIOData err; 100 QTAILQ_ENTRY(GuestExecInfo) next; 101 }; 102 typedef struct GuestExecInfo GuestExecInfo; 103 104 static struct { 105 QTAILQ_HEAD(, GuestExecInfo) processes; 106 } guest_exec_state = { 107 .processes = QTAILQ_HEAD_INITIALIZER(guest_exec_state.processes), 108 }; 109 110 static int64_t gpid_to_int64(GPid pid) 111 { 112 #ifdef G_OS_WIN32 113 return GetProcessId(pid); 114 #else 115 return (int64_t)pid; 116 #endif 117 } 118 119 static GuestExecInfo *guest_exec_info_add(GPid pid) 120 { 121 GuestExecInfo *gei; 122 123 gei = g_new0(GuestExecInfo, 1); 124 gei->pid = pid; 125 gei->pid_numeric = gpid_to_int64(pid); 126 QTAILQ_INSERT_TAIL(&guest_exec_state.processes, gei, next); 127 128 return gei; 129 } 130 131 static GuestExecInfo *guest_exec_info_find(int64_t pid_numeric) 132 { 133 GuestExecInfo *gei; 134 135 QTAILQ_FOREACH(gei, &guest_exec_state.processes, next) { 136 if (gei->pid_numeric == pid_numeric) { 137 return gei; 138 } 139 } 140 141 return NULL; 142 } 143 144 GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **err) 145 { 146 GuestExecInfo *gei; 147 GuestExecStatus *ges; 148 149 slog("guest-exec-status called, pid: %u", (uint32_t)pid); 150 151 gei = guest_exec_info_find(pid); 152 if (gei == NULL) { 153 error_setg(err, QERR_INVALID_PARAMETER, "pid"); 154 return NULL; 155 } 156 157 ges = g_new0(GuestExecStatus, 1); 158 159 bool finished = g_atomic_int_get(&gei->finished); 160 161 /* need to wait till output channels are closed 162 * to be sure we captured all output at this point */ 163 if (gei->has_output) { 164 finished = finished && g_atomic_int_get(&gei->out.closed); 165 finished = finished && g_atomic_int_get(&gei->err.closed); 166 } 167 168 ges->exited = finished; 169 if (finished) { 170 /* Glib has no portable way to parse exit status. 171 * On UNIX, we can get either exit code from normal termination 172 * or signal number. 173 * On Windows, it is either the same exit code or the exception 174 * value for an unhandled exception that caused the process 175 * to terminate. 176 * See MSDN for GetExitCodeProcess() and ntstatus.h for possible 177 * well-known codes, e.g. C0000005 ACCESS_DENIED - analog of SIGSEGV 178 * References: 179 * https://msdn.microsoft.com/en-us/library/windows/desktop/ms683189(v=vs.85).aspx 180 * https://msdn.microsoft.com/en-us/library/aa260331(v=vs.60).aspx 181 */ 182 #ifdef G_OS_WIN32 183 /* Additionally WIN32 does not provide any additional information 184 * on whetherthe child exited or terminated via signal. 185 * We use this simple range check to distingish application exit code 186 * (usually value less then 256) and unhandled exception code with 187 * ntstatus (always value greater then 0xC0000005). */ 188 if ((uint32_t)gei->status < 0xC0000000U) { 189 ges->has_exitcode = true; 190 ges->exitcode = gei->status; 191 } else { 192 ges->has_signal = true; 193 ges->signal = gei->status; 194 } 195 #else 196 if (WIFEXITED(gei->status)) { 197 ges->has_exitcode = true; 198 ges->exitcode = WEXITSTATUS(gei->status); 199 } else if (WIFSIGNALED(gei->status)) { 200 ges->has_signal = true; 201 ges->signal = WTERMSIG(gei->status); 202 } 203 #endif 204 if (gei->out.length > 0) { 205 ges->has_out_data = true; 206 ges->out_data = g_base64_encode(gei->out.data, gei->out.length); 207 g_free(gei->out.data); 208 ges->has_out_truncated = gei->out.truncated; 209 } 210 211 if (gei->err.length > 0) { 212 ges->has_err_data = true; 213 ges->err_data = g_base64_encode(gei->err.data, gei->err.length); 214 g_free(gei->err.data); 215 ges->has_err_truncated = gei->err.truncated; 216 } 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_malloc(count * sizeof(char *)); 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 /** Reset ignored signals back to default. */ 273 static void guest_exec_task_setup(gpointer data) 274 { 275 #if !defined(G_OS_WIN32) 276 struct sigaction sigact; 277 278 memset(&sigact, 0, sizeof(struct sigaction)); 279 sigact.sa_handler = SIG_DFL; 280 281 if (sigaction(SIGPIPE, &sigact, NULL) != 0) { 282 slog("sigaction() failed to reset child process's SIGPIPE: %s", 283 strerror(errno)); 284 } 285 #endif 286 } 287 288 static gboolean guest_exec_input_watch(GIOChannel *ch, 289 GIOCondition cond, gpointer p_) 290 { 291 GuestExecIOData *p = (GuestExecIOData *)p_; 292 gsize bytes_written = 0; 293 GIOStatus status; 294 GError *gerr = NULL; 295 296 /* nothing left to write */ 297 if (p->size == p->length) { 298 goto done; 299 } 300 301 status = g_io_channel_write_chars(ch, (gchar *)p->data + p->length, 302 p->size - p->length, &bytes_written, &gerr); 303 304 /* can be not 0 even if not G_IO_STATUS_NORMAL */ 305 if (bytes_written != 0) { 306 p->length += bytes_written; 307 } 308 309 /* continue write, our callback will be called again */ 310 if (status == G_IO_STATUS_NORMAL || status == G_IO_STATUS_AGAIN) { 311 return true; 312 } 313 314 if (gerr) { 315 g_warning("qga: i/o error writing to input_data channel: %s", 316 gerr->message); 317 g_error_free(gerr); 318 } 319 320 done: 321 g_io_channel_shutdown(ch, true, NULL); 322 g_io_channel_unref(ch); 323 g_atomic_int_set(&p->closed, 1); 324 g_free(p->data); 325 326 return false; 327 } 328 329 static gboolean guest_exec_output_watch(GIOChannel *ch, 330 GIOCondition cond, gpointer p_) 331 { 332 GuestExecIOData *p = (GuestExecIOData *)p_; 333 gsize bytes_read; 334 GIOStatus gstatus; 335 336 if (cond == G_IO_HUP || cond == G_IO_ERR) { 337 goto close; 338 } 339 340 if (p->size == p->length) { 341 gpointer t = NULL; 342 if (!p->truncated && p->size < GUEST_EXEC_MAX_OUTPUT) { 343 t = g_try_realloc(p->data, p->size + GUEST_EXEC_IO_SIZE); 344 } 345 if (t == NULL) { 346 /* ignore truncated output */ 347 gchar buf[GUEST_EXEC_IO_SIZE]; 348 349 p->truncated = true; 350 gstatus = g_io_channel_read_chars(ch, buf, sizeof(buf), 351 &bytes_read, NULL); 352 if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) { 353 goto close; 354 } 355 356 return true; 357 } 358 p->size += GUEST_EXEC_IO_SIZE; 359 p->data = t; 360 } 361 362 /* Calling read API once. 363 * On next available data our callback will be called again */ 364 gstatus = g_io_channel_read_chars(ch, (gchar *)p->data + p->length, 365 p->size - p->length, &bytes_read, NULL); 366 if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) { 367 goto close; 368 } 369 370 p->length += bytes_read; 371 372 return true; 373 374 close: 375 g_io_channel_unref(ch); 376 g_atomic_int_set(&p->closed, 1); 377 return false; 378 } 379 380 GuestExec *qmp_guest_exec(const char *path, 381 bool has_arg, strList *arg, 382 bool has_env, strList *env, 383 bool has_input_data, const char *input_data, 384 bool has_capture_output, bool capture_output, 385 Error **err) 386 { 387 GPid pid; 388 GuestExec *ge = NULL; 389 GuestExecInfo *gei; 390 char **argv, **envp; 391 strList arglist; 392 gboolean ret; 393 GError *gerr = NULL; 394 gint in_fd, out_fd, err_fd; 395 GIOChannel *in_ch, *out_ch, *err_ch; 396 GSpawnFlags flags; 397 bool has_output = (has_capture_output && capture_output); 398 uint8_t *input = NULL; 399 size_t ninput = 0; 400 401 arglist.value = (char *)path; 402 arglist.next = has_arg ? arg : NULL; 403 404 if (has_input_data) { 405 input = qbase64_decode(input_data, -1, &ninput, err); 406 if (!input) { 407 return NULL; 408 } 409 } 410 411 argv = guest_exec_get_args(&arglist, true); 412 envp = has_env ? guest_exec_get_args(env, false) : NULL; 413 414 flags = G_SPAWN_SEARCH_PATH | G_SPAWN_DO_NOT_REAP_CHILD; 415 #if GLIB_CHECK_VERSION(2, 33, 2) 416 flags |= G_SPAWN_SEARCH_PATH_FROM_ENVP; 417 #endif 418 if (!has_output) { 419 flags |= G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL; 420 } 421 422 ret = g_spawn_async_with_pipes(NULL, argv, envp, flags, 423 guest_exec_task_setup, NULL, &pid, has_input_data ? &in_fd : NULL, 424 has_output ? &out_fd : NULL, has_output ? &err_fd : NULL, &gerr); 425 if (!ret) { 426 error_setg(err, QERR_QGA_COMMAND_FAILED, gerr->message); 427 g_error_free(gerr); 428 goto done; 429 } 430 431 ge = g_new0(GuestExec, 1); 432 ge->pid = gpid_to_int64(pid); 433 434 gei = guest_exec_info_add(pid); 435 gei->has_output = has_output; 436 g_child_watch_add(pid, guest_exec_child_watch, gei); 437 438 if (has_input_data) { 439 gei->in.data = input; 440 gei->in.size = ninput; 441 #ifdef G_OS_WIN32 442 in_ch = g_io_channel_win32_new_fd(in_fd); 443 #else 444 in_ch = g_io_channel_unix_new(in_fd); 445 #endif 446 g_io_channel_set_encoding(in_ch, NULL, NULL); 447 g_io_channel_set_buffered(in_ch, false); 448 g_io_channel_set_flags(in_ch, G_IO_FLAG_NONBLOCK, NULL); 449 g_io_add_watch(in_ch, G_IO_OUT, guest_exec_input_watch, &gei->in); 450 } 451 452 if (has_output) { 453 #ifdef G_OS_WIN32 454 out_ch = g_io_channel_win32_new_fd(out_fd); 455 err_ch = g_io_channel_win32_new_fd(err_fd); 456 #else 457 out_ch = g_io_channel_unix_new(out_fd); 458 err_ch = g_io_channel_unix_new(err_fd); 459 #endif 460 g_io_channel_set_encoding(out_ch, NULL, NULL); 461 g_io_channel_set_encoding(err_ch, NULL, NULL); 462 g_io_channel_set_buffered(out_ch, false); 463 g_io_channel_set_buffered(err_ch, false); 464 g_io_add_watch(out_ch, G_IO_IN | G_IO_HUP, 465 guest_exec_output_watch, &gei->out); 466 g_io_add_watch(err_ch, G_IO_IN | G_IO_HUP, 467 guest_exec_output_watch, &gei->err); 468 } 469 470 done: 471 g_free(argv); 472 g_free(envp); 473 474 return ge; 475 } 476