Merge remote-tracking branch 'remotes/kraxel/tags/vga-20210723-pull-request' into...
[qemu.git] / qga / commands.c
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
70 cmd_info = g_new0(GuestAgentCommandInfo, 1);
71 cmd_info->name = g_strdup(qmp_command_name(cmd));
72 cmd_info->enabled = qmp_command_is_enabled(cmd);
73 cmd_info->success_response = qmp_has_success_response(cmd);
74
75 QAPI_LIST_PREPEND(info->supported_commands, cmd_info);
76 }
77
78 struct GuestAgentInfo *qmp_guest_info(Error **errp)
79 {
80 GuestAgentInfo *info = g_new0(GuestAgentInfo, 1);
81
82 info->version = g_strdup(QEMU_VERSION);
83 qmp_for_each_command(&ga_commands, qmp_command_info, info);
84 return info;
85 }
86
87 struct GuestExecIOData {
88 guchar *data;
89 gsize size;
90 gsize length;
91 bool closed;
92 bool truncated;
93 const char *name;
94 };
95 typedef struct GuestExecIOData GuestExecIOData;
96
97 struct GuestExecInfo {
98 GPid pid;
99 int64_t pid_numeric;
100 gint status;
101 bool has_output;
102 bool finished;
103 GuestExecIOData in;
104 GuestExecIOData out;
105 GuestExecIOData err;
106 QTAILQ_ENTRY(GuestExecInfo) next;
107 };
108 typedef struct GuestExecInfo GuestExecInfo;
109
110 static struct {
111 QTAILQ_HEAD(, GuestExecInfo) processes;
112 } guest_exec_state = {
113 .processes = QTAILQ_HEAD_INITIALIZER(guest_exec_state.processes),
114 };
115
116 static int64_t gpid_to_int64(GPid pid)
117 {
118 #ifdef G_OS_WIN32
119 return GetProcessId(pid);
120 #else
121 return (int64_t)pid;
122 #endif
123 }
124
125 static GuestExecInfo *guest_exec_info_add(GPid pid)
126 {
127 GuestExecInfo *gei;
128
129 gei = g_new0(GuestExecInfo, 1);
130 gei->pid = pid;
131 gei->pid_numeric = gpid_to_int64(pid);
132 QTAILQ_INSERT_TAIL(&guest_exec_state.processes, gei, next);
133
134 return gei;
135 }
136
137 static GuestExecInfo *guest_exec_info_find(int64_t pid_numeric)
138 {
139 GuestExecInfo *gei;
140
141 QTAILQ_FOREACH(gei, &guest_exec_state.processes, next) {
142 if (gei->pid_numeric == pid_numeric) {
143 return gei;
144 }
145 }
146
147 return NULL;
148 }
149
150 GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **errp)
151 {
152 GuestExecInfo *gei;
153 GuestExecStatus *ges;
154
155 slog("guest-exec-status called, pid: %u", (uint32_t)pid);
156
157 gei = guest_exec_info_find(pid);
158 if (gei == NULL) {
159 error_setg(errp, QERR_INVALID_PARAMETER, "pid");
160 return NULL;
161 }
162
163 ges = g_new0(GuestExecStatus, 1);
164
165 bool finished = qatomic_mb_read(&gei->finished);
166
167 /* need to wait till output channels are closed
168 * to be sure we captured all output at this point */
169 if (gei->has_output) {
170 finished = finished && qatomic_mb_read(&gei->out.closed);
171 finished = finished && qatomic_mb_read(&gei->err.closed);
172 }
173
174 ges->exited = finished;
175 if (finished) {
176 /* Glib has no portable way to parse exit status.
177 * On UNIX, we can get either exit code from normal termination
178 * or signal number.
179 * On Windows, it is either the same exit code or the exception
180 * value for an unhandled exception that caused the process
181 * to terminate.
182 * See MSDN for GetExitCodeProcess() and ntstatus.h for possible
183 * well-known codes, e.g. C0000005 ACCESS_DENIED - analog of SIGSEGV
184 * References:
185 * https://msdn.microsoft.com/en-us/library/windows/desktop/ms683189(v=vs.85).aspx
186 * https://msdn.microsoft.com/en-us/library/aa260331(v=vs.60).aspx
187 */
188 #ifdef G_OS_WIN32
189 /* Additionally WIN32 does not provide any additional information
190 * on whether the child exited or terminated via signal.
191 * We use this simple range check to distinguish application exit code
192 * (usually value less then 256) and unhandled exception code with
193 * ntstatus (always value greater then 0xC0000005). */
194 if ((uint32_t)gei->status < 0xC0000000U) {
195 ges->has_exitcode = true;
196 ges->exitcode = gei->status;
197 } else {
198 ges->has_signal = true;
199 ges->signal = gei->status;
200 }
201 #else
202 if (WIFEXITED(gei->status)) {
203 ges->has_exitcode = true;
204 ges->exitcode = WEXITSTATUS(gei->status);
205 } else if (WIFSIGNALED(gei->status)) {
206 ges->has_signal = true;
207 ges->signal = WTERMSIG(gei->status);
208 }
209 #endif
210 if (gei->out.length > 0) {
211 ges->has_out_data = true;
212 ges->out_data = g_base64_encode(gei->out.data, gei->out.length);
213 g_free(gei->out.data);
214 ges->has_out_truncated = gei->out.truncated;
215 }
216
217 if (gei->err.length > 0) {
218 ges->has_err_data = true;
219 ges->err_data = g_base64_encode(gei->err.data, gei->err.length);
220 g_free(gei->err.data);
221 ges->has_err_truncated = gei->err.truncated;
222 }
223
224 QTAILQ_REMOVE(&guest_exec_state.processes, gei, next);
225 g_free(gei);
226 }
227
228 return ges;
229 }
230
231 /* Get environment variables or arguments array for execve(). */
232 static char **guest_exec_get_args(const strList *entry, bool log)
233 {
234 const strList *it;
235 int count = 1, i = 0; /* reserve for NULL terminator */
236 char **args;
237 char *str; /* for logging array of arguments */
238 size_t str_size = 1;
239
240 for (it = entry; it != NULL; it = it->next) {
241 count++;
242 str_size += 1 + strlen(it->value);
243 }
244
245 str = g_malloc(str_size);
246 *str = 0;
247 args = g_malloc(count * sizeof(char *));
248 for (it = entry; it != NULL; it = it->next) {
249 args[i++] = it->value;
250 pstrcat(str, str_size, it->value);
251 if (it->next) {
252 pstrcat(str, str_size, " ");
253 }
254 }
255 args[i] = NULL;
256
257 if (log) {
258 slog("guest-exec called: \"%s\"", str);
259 }
260 g_free(str);
261
262 return args;
263 }
264
265 static void guest_exec_child_watch(GPid pid, gint status, gpointer data)
266 {
267 GuestExecInfo *gei = (GuestExecInfo *)data;
268
269 g_debug("guest_exec_child_watch called, pid: %d, status: %u",
270 (int32_t)gpid_to_int64(pid), (uint32_t)status);
271
272 gei->status = status;
273 qatomic_mb_set(&gei->finished, true);
274
275 g_spawn_close_pid(pid);
276 }
277
278 /** Reset ignored signals back to default. */
279 static void guest_exec_task_setup(gpointer data)
280 {
281 #if !defined(G_OS_WIN32)
282 struct sigaction sigact;
283
284 memset(&sigact, 0, sizeof(struct sigaction));
285 sigact.sa_handler = SIG_DFL;
286
287 if (sigaction(SIGPIPE, &sigact, NULL) != 0) {
288 slog("sigaction() failed to reset child process's SIGPIPE: %s",
289 strerror(errno));
290 }
291 #endif
292 }
293
294 static gboolean guest_exec_input_watch(GIOChannel *ch,
295 GIOCondition cond, gpointer p_)
296 {
297 GuestExecIOData *p = (GuestExecIOData *)p_;
298 gsize bytes_written = 0;
299 GIOStatus status;
300 GError *gerr = NULL;
301
302 /* nothing left to write */
303 if (p->size == p->length) {
304 goto done;
305 }
306
307 status = g_io_channel_write_chars(ch, (gchar *)p->data + p->length,
308 p->size - p->length, &bytes_written, &gerr);
309
310 /* can be not 0 even if not G_IO_STATUS_NORMAL */
311 if (bytes_written != 0) {
312 p->length += bytes_written;
313 }
314
315 /* continue write, our callback will be called again */
316 if (status == G_IO_STATUS_NORMAL || status == G_IO_STATUS_AGAIN) {
317 return true;
318 }
319
320 if (gerr) {
321 g_warning("qga: i/o error writing to input_data channel: %s",
322 gerr->message);
323 g_error_free(gerr);
324 }
325
326 done:
327 g_io_channel_shutdown(ch, true, NULL);
328 g_io_channel_unref(ch);
329 qatomic_mb_set(&p->closed, true);
330 g_free(p->data);
331
332 return false;
333 }
334
335 static gboolean guest_exec_output_watch(GIOChannel *ch,
336 GIOCondition cond, gpointer p_)
337 {
338 GuestExecIOData *p = (GuestExecIOData *)p_;
339 gsize bytes_read;
340 GIOStatus gstatus;
341
342 if (cond == G_IO_HUP || cond == G_IO_ERR) {
343 goto close;
344 }
345
346 if (p->size == p->length) {
347 gpointer t = NULL;
348 if (!p->truncated && p->size < GUEST_EXEC_MAX_OUTPUT) {
349 t = g_try_realloc(p->data, p->size + GUEST_EXEC_IO_SIZE);
350 }
351 if (t == NULL) {
352 /* ignore truncated output */
353 gchar buf[GUEST_EXEC_IO_SIZE];
354
355 p->truncated = true;
356 gstatus = g_io_channel_read_chars(ch, buf, sizeof(buf),
357 &bytes_read, NULL);
358 if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) {
359 goto close;
360 }
361
362 return true;
363 }
364 p->size += GUEST_EXEC_IO_SIZE;
365 p->data = t;
366 }
367
368 /* Calling read API once.
369 * On next available data our callback will be called again */
370 gstatus = g_io_channel_read_chars(ch, (gchar *)p->data + p->length,
371 p->size - p->length, &bytes_read, NULL);
372 if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) {
373 goto close;
374 }
375
376 p->length += bytes_read;
377
378 return true;
379
380 close:
381 g_io_channel_shutdown(ch, true, NULL);
382 g_io_channel_unref(ch);
383 qatomic_mb_set(&p->closed, true);
384 return false;
385 }
386
387 GuestExec *qmp_guest_exec(const char *path,
388 bool has_arg, strList *arg,
389 bool has_env, strList *env,
390 bool has_input_data, const char *input_data,
391 bool has_capture_output, bool capture_output,
392 Error **errp)
393 {
394 GPid pid;
395 GuestExec *ge = NULL;
396 GuestExecInfo *gei;
397 char **argv, **envp;
398 strList arglist;
399 gboolean ret;
400 GError *gerr = NULL;
401 gint in_fd, out_fd, err_fd;
402 GIOChannel *in_ch, *out_ch, *err_ch;
403 GSpawnFlags flags;
404 bool has_output = (has_capture_output && capture_output);
405 uint8_t *input = NULL;
406 size_t ninput = 0;
407
408 arglist.value = (char *)path;
409 arglist.next = has_arg ? arg : NULL;
410
411 if (has_input_data) {
412 input = qbase64_decode(input_data, -1, &ninput, errp);
413 if (!input) {
414 return NULL;
415 }
416 }
417
418 argv = guest_exec_get_args(&arglist, true);
419 envp = has_env ? guest_exec_get_args(env, false) : NULL;
420
421 flags = G_SPAWN_SEARCH_PATH | G_SPAWN_DO_NOT_REAP_CHILD |
422 G_SPAWN_SEARCH_PATH_FROM_ENVP;
423 if (!has_output) {
424 flags |= G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL;
425 }
426
427 ret = g_spawn_async_with_pipes(NULL, argv, envp, flags,
428 guest_exec_task_setup, NULL, &pid, has_input_data ? &in_fd : NULL,
429 has_output ? &out_fd : NULL, has_output ? &err_fd : NULL, &gerr);
430 if (!ret) {
431 error_setg(errp, QERR_QGA_COMMAND_FAILED, gerr->message);
432 g_error_free(gerr);
433 goto done;
434 }
435
436 ge = g_new0(GuestExec, 1);
437 ge->pid = gpid_to_int64(pid);
438
439 gei = guest_exec_info_add(pid);
440 gei->has_output = has_output;
441 g_child_watch_add(pid, guest_exec_child_watch, gei);
442
443 if (has_input_data) {
444 gei->in.data = input;
445 gei->in.size = ninput;
446 #ifdef G_OS_WIN32
447 in_ch = g_io_channel_win32_new_fd(in_fd);
448 #else
449 in_ch = g_io_channel_unix_new(in_fd);
450 #endif
451 g_io_channel_set_encoding(in_ch, NULL, NULL);
452 g_io_channel_set_buffered(in_ch, false);
453 g_io_channel_set_flags(in_ch, G_IO_FLAG_NONBLOCK, NULL);
454 g_io_channel_set_close_on_unref(in_ch, true);
455 g_io_add_watch(in_ch, G_IO_OUT, guest_exec_input_watch, &gei->in);
456 }
457
458 if (has_output) {
459 #ifdef G_OS_WIN32
460 out_ch = g_io_channel_win32_new_fd(out_fd);
461 err_ch = g_io_channel_win32_new_fd(err_fd);
462 #else
463 out_ch = g_io_channel_unix_new(out_fd);
464 err_ch = g_io_channel_unix_new(err_fd);
465 #endif
466 g_io_channel_set_encoding(out_ch, NULL, NULL);
467 g_io_channel_set_encoding(err_ch, NULL, NULL);
468 g_io_channel_set_buffered(out_ch, false);
469 g_io_channel_set_buffered(err_ch, false);
470 g_io_channel_set_close_on_unref(out_ch, true);
471 g_io_channel_set_close_on_unref(err_ch, true);
472 g_io_add_watch(out_ch, G_IO_IN | G_IO_HUP,
473 guest_exec_output_watch, &gei->out);
474 g_io_add_watch(err_ch, G_IO_IN | G_IO_HUP,
475 guest_exec_output_watch, &gei->err);
476 }
477
478 done:
479 g_free(argv);
480 g_free(envp);
481
482 return ge;
483 }
484
485 /* Convert GuestFileWhence (either a raw integer or an enum value) into
486 * the guest's SEEK_ constants. */
487 int ga_parse_whence(GuestFileWhence *whence, Error **errp)
488 {
489 /*
490 * Exploit the fact that we picked values to match QGA_SEEK_*;
491 * however, we have to use a temporary variable since the union
492 * members may have different size.
493 */
494 if (whence->type == QTYPE_QSTRING) {
495 int value = whence->u.name;
496 whence->type = QTYPE_QNUM;
497 whence->u.value = value;
498 }
499 switch (whence->u.value) {
500 case QGA_SEEK_SET:
501 return SEEK_SET;
502 case QGA_SEEK_CUR:
503 return SEEK_CUR;
504 case QGA_SEEK_END:
505 return SEEK_END;
506 }
507 error_setg(errp, "invalid whence code %"PRId64, whence->u.value);
508 return -1;
509 }
510
511 GuestHostName *qmp_guest_get_host_name(Error **errp)
512 {
513 GuestHostName *result = NULL;
514 g_autofree char *hostname = qemu_get_host_name(errp);
515
516 /*
517 * We want to avoid using g_get_host_name() because that
518 * caches the result and we wouldn't reflect changes in the
519 * host name.
520 */
521
522 if (!hostname) {
523 hostname = g_strdup("localhost");
524 }
525
526 result = g_new0(GuestHostName, 1);
527 result->host_name = g_steal_pointer(&hostname);
528 return result;
529 }
530
531 GuestTimezone *qmp_guest_get_timezone(Error **errp)
532 {
533 GuestTimezone *info = NULL;
534 GTimeZone *tz = NULL;
535 gint64 now = 0;
536 gint32 intv = 0;
537 gchar const *name = NULL;
538
539 info = g_new0(GuestTimezone, 1);
540 tz = g_time_zone_new_local();
541 if (tz == NULL) {
542 error_setg(errp, QERR_QGA_COMMAND_FAILED,
543 "Couldn't retrieve local timezone");
544 goto error;
545 }
546
547 now = g_get_real_time() / G_USEC_PER_SEC;
548 intv = g_time_zone_find_interval(tz, G_TIME_TYPE_UNIVERSAL, now);
549 info->offset = g_time_zone_get_offset(tz, intv);
550 name = g_time_zone_get_abbreviation(tz, intv);
551 if (name != NULL) {
552 info->has_zone = true;
553 info->zone = g_strdup(name);
554 }
555 g_time_zone_unref(tz);
556
557 return info;
558
559 error:
560 g_free(info);
561 return NULL;
562 }
563
564 GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,
565 int64_t count, Error **errp)
566 {
567 GuestFileHandle *gfh = guest_file_handle_find(handle, errp);
568 GuestFileRead *read_data;
569
570 if (!gfh) {
571 return NULL;
572 }
573 if (!has_count) {
574 count = QGA_READ_COUNT_DEFAULT;
575 } else if (count < 0 || count > GUEST_FILE_READ_COUNT_MAX) {
576 error_setg(errp, "value '%" PRId64 "' is invalid for argument count",
577 count);
578 return NULL;
579 }
580
581 read_data = guest_file_read_unsafe(gfh, count, errp);
582 if (!read_data) {
583 slog("guest-file-write failed, handle: %" PRId64, handle);
584 }
585
586 return read_data;
587 }