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 "qemu/base64.h"
19 #include "qemu/cutils.h"
20 #include "commands-common.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 * Maximum file size to read - 48MB
28 *
29 * (48MB + Base64 3:4 overhead = JSON parser 64 MB limit)
30 */
31 #define GUEST_FILE_READ_COUNT_MAX (48 * MiB)
32
33 /* Note: in some situations, like with the fsfreeze, logging may be
34 * temporarily disabled. if it is necessary that a command be able
35 * to log for accounting purposes, check ga_logging_enabled() beforehand.
36 */
slog(const gchar * fmt,...)37 void slog(const gchar *fmt, ...)
38 {
39 va_list ap;
40
41 va_start(ap, fmt);
42 g_logv("syslog", G_LOG_LEVEL_INFO, fmt, ap);
43 va_end(ap);
44 }
45
qmp_guest_sync_delimited(int64_t id,Error ** errp)46 int64_t qmp_guest_sync_delimited(int64_t id, Error **errp)
47 {
48 ga_set_response_delimited(ga_state);
49 return id;
50 }
51
qmp_guest_sync(int64_t id,Error ** errp)52 int64_t qmp_guest_sync(int64_t id, Error **errp)
53 {
54 return id;
55 }
56
qmp_guest_ping(Error ** errp)57 void qmp_guest_ping(Error **errp)
58 {
59 slog("guest-ping called");
60 }
61
qmp_command_info(const QmpCommand * cmd,void * opaque)62 static void qmp_command_info(const QmpCommand *cmd, void *opaque)
63 {
64 GuestAgentInfo *info = opaque;
65 GuestAgentCommandInfo *cmd_info;
66
67 cmd_info = g_new0(GuestAgentCommandInfo, 1);
68 cmd_info->name = g_strdup(qmp_command_name(cmd));
69 cmd_info->enabled = qmp_command_is_enabled(cmd);
70 cmd_info->success_response = qmp_has_success_response(cmd);
71
72 QAPI_LIST_PREPEND(info->supported_commands, cmd_info);
73 }
74
qmp_guest_info(Error ** errp)75 struct GuestAgentInfo *qmp_guest_info(Error **errp)
76 {
77 GuestAgentInfo *info = g_new0(GuestAgentInfo, 1);
78
79 info->version = g_strdup(QEMU_VERSION);
80 qmp_for_each_command(&ga_commands, qmp_command_info, info);
81 return info;
82 }
83
84 struct GuestExecIOData {
85 guchar *data;
86 gsize size;
87 gsize length;
88 bool closed;
89 bool truncated;
90 const char *name;
91 };
92 typedef struct GuestExecIOData GuestExecIOData;
93
94 struct GuestExecInfo {
95 GPid pid;
96 int64_t pid_numeric;
97 gint status;
98 bool has_output;
99 bool finished;
100 GuestExecIOData in;
101 GuestExecIOData out;
102 GuestExecIOData err;
103 QTAILQ_ENTRY(GuestExecInfo) next;
104 };
105 typedef struct GuestExecInfo GuestExecInfo;
106
107 static struct {
108 QTAILQ_HEAD(, GuestExecInfo) processes;
109 } guest_exec_state = {
110 .processes = QTAILQ_HEAD_INITIALIZER(guest_exec_state.processes),
111 };
112
gpid_to_int64(GPid pid)113 static int64_t gpid_to_int64(GPid pid)
114 {
115 #ifdef G_OS_WIN32
116 return GetProcessId(pid);
117 #else
118 return (int64_t)pid;
119 #endif
120 }
121
guest_exec_info_add(GPid pid)122 static GuestExecInfo *guest_exec_info_add(GPid pid)
123 {
124 GuestExecInfo *gei;
125
126 gei = g_new0(GuestExecInfo, 1);
127 gei->pid = pid;
128 gei->pid_numeric = gpid_to_int64(pid);
129 QTAILQ_INSERT_TAIL(&guest_exec_state.processes, gei, next);
130
131 return gei;
132 }
133
guest_exec_info_find(int64_t pid_numeric)134 static GuestExecInfo *guest_exec_info_find(int64_t pid_numeric)
135 {
136 GuestExecInfo *gei;
137
138 QTAILQ_FOREACH(gei, &guest_exec_state.processes, next) {
139 if (gei->pid_numeric == pid_numeric) {
140 return gei;
141 }
142 }
143
144 return NULL;
145 }
146
qmp_guest_exec_status(int64_t pid,Error ** errp)147 GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **errp)
148 {
149 GuestExecInfo *gei;
150 GuestExecStatus *ges;
151
152 slog("guest-exec-status called, pid: %u", (uint32_t)pid);
153
154 gei = guest_exec_info_find(pid);
155 if (gei == NULL) {
156 error_setg(errp, "PID " PRId64 " does not exist");
157 return NULL;
158 }
159
160 ges = g_new0(GuestExecStatus, 1);
161
162 bool finished = gei->finished;
163
164 /* need to wait till output channels are closed
165 * to be sure we captured all output at this point */
166 if (gei->has_output) {
167 finished &= gei->out.closed && 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->out_data = g_base64_encode(gei->out.data, gei->out.length);
208 ges->has_out_truncated = true;
209 ges->out_truncated = gei->out.truncated;
210 }
211 g_free(gei->out.data);
212
213 if (gei->err.length > 0) {
214 ges->err_data = g_base64_encode(gei->err.data, gei->err.length);
215 ges->has_err_truncated = true;
216 ges->err_truncated = gei->err.truncated;
217 }
218 g_free(gei->err.data);
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(). */
guest_exec_get_args(const strList * entry,bool log)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
guest_exec_child_watch(GPid pid,gint status,gpointer data)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
guest_exec_task_setup(gpointer data)274 static void guest_exec_task_setup(gpointer data)
275 {
276 #if !defined(G_OS_WIN32)
277 bool has_merge = *(bool *)data;
278 struct sigaction sigact;
279
280 if (has_merge) {
281 /*
282 * FIXME: When `GLIB_VERSION_MIN_REQUIRED` is bumped to 2.58+, use
283 * g_spawn_async_with_fds() to be portable on windows. The current
284 * logic does not work on windows b/c `GSpawnChildSetupFunc` is run
285 * inside the parent, not the child.
286 */
287 if (dup2(STDOUT_FILENO, STDERR_FILENO) != 0) {
288 slog("dup2() failed to merge stderr into stdout: %s",
289 strerror(errno));
290 }
291 }
292
293 /* Reset ignored signals back to default. */
294 memset(&sigact, 0, sizeof(struct sigaction));
295 sigact.sa_handler = SIG_DFL;
296
297 if (sigaction(SIGPIPE, &sigact, NULL) != 0) {
298 slog("sigaction() failed to reset child process's SIGPIPE: %s",
299 strerror(errno));
300 }
301 #endif
302 }
303
guest_exec_input_watch(GIOChannel * ch,GIOCondition cond,gpointer p_)304 static gboolean guest_exec_input_watch(GIOChannel *ch,
305 GIOCondition cond, gpointer p_)
306 {
307 GuestExecIOData *p = (GuestExecIOData *)p_;
308 gsize bytes_written = 0;
309 GIOStatus status;
310 GError *gerr = NULL;
311
312 /* nothing left to write */
313 if (p->size == p->length) {
314 goto done;
315 }
316
317 status = g_io_channel_write_chars(ch, (gchar *)p->data + p->length,
318 p->size - p->length, &bytes_written, &gerr);
319
320 /* can be not 0 even if not G_IO_STATUS_NORMAL */
321 if (bytes_written != 0) {
322 p->length += bytes_written;
323 }
324
325 /* continue write, our callback will be called again */
326 if (status == G_IO_STATUS_NORMAL || status == G_IO_STATUS_AGAIN) {
327 return true;
328 }
329
330 if (gerr) {
331 g_warning("qga: i/o error writing to input_data channel: %s",
332 gerr->message);
333 g_error_free(gerr);
334 }
335
336 done:
337 g_io_channel_shutdown(ch, true, NULL);
338 g_io_channel_unref(ch);
339 p->closed = true;
340 g_free(p->data);
341
342 return false;
343 }
344
guest_exec_output_watch(GIOChannel * ch,GIOCondition cond,gpointer p_)345 static gboolean guest_exec_output_watch(GIOChannel *ch,
346 GIOCondition cond, gpointer p_)
347 {
348 GuestExecIOData *p = (GuestExecIOData *)p_;
349 gsize bytes_read;
350 GIOStatus gstatus;
351
352 if (cond == G_IO_HUP || cond == G_IO_ERR) {
353 goto close;
354 }
355
356 if (p->size == p->length) {
357 gpointer t = NULL;
358 if (!p->truncated && p->size < GUEST_EXEC_MAX_OUTPUT) {
359 t = g_try_realloc(p->data, p->size + GUEST_EXEC_IO_SIZE);
360 }
361 if (t == NULL) {
362 /* ignore truncated output */
363 gchar buf[GUEST_EXEC_IO_SIZE];
364
365 p->truncated = true;
366 gstatus = g_io_channel_read_chars(ch, buf, sizeof(buf),
367 &bytes_read, NULL);
368 if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) {
369 goto close;
370 }
371
372 return true;
373 }
374 p->size += GUEST_EXEC_IO_SIZE;
375 p->data = t;
376 }
377
378 /* Calling read API once.
379 * On next available data our callback will be called again */
380 gstatus = g_io_channel_read_chars(ch, (gchar *)p->data + p->length,
381 p->size - p->length, &bytes_read, NULL);
382 if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) {
383 goto close;
384 }
385
386 p->length += bytes_read;
387
388 return true;
389
390 close:
391 g_io_channel_shutdown(ch, true, NULL);
392 g_io_channel_unref(ch);
393 p->closed = true;
394 return false;
395 }
396
ga_parse_capture_output(GuestExecCaptureOutput * capture_output)397 static GuestExecCaptureOutputMode ga_parse_capture_output(
398 GuestExecCaptureOutput *capture_output)
399 {
400 if (!capture_output)
401 return GUEST_EXEC_CAPTURE_OUTPUT_MODE_NONE;
402 else if (capture_output->type == QTYPE_QBOOL)
403 return capture_output->u.flag ? GUEST_EXEC_CAPTURE_OUTPUT_MODE_SEPARATED
404 : GUEST_EXEC_CAPTURE_OUTPUT_MODE_NONE;
405 else
406 return capture_output->u.mode;
407 }
408
qmp_guest_exec(const char * path,bool has_arg,strList * arg,bool has_env,strList * env,const char * input_data,GuestExecCaptureOutput * capture_output,Error ** errp)409 GuestExec *qmp_guest_exec(const char *path,
410 bool has_arg, strList *arg,
411 bool has_env, strList *env,
412 const char *input_data,
413 GuestExecCaptureOutput *capture_output,
414 Error **errp)
415 {
416 GPid pid;
417 GuestExec *ge = NULL;
418 GuestExecInfo *gei;
419 char **argv, **envp;
420 strList arglist;
421 gboolean ret;
422 GError *gerr = NULL;
423 gint in_fd, out_fd, err_fd;
424 GIOChannel *in_ch, *out_ch, *err_ch;
425 GSpawnFlags flags;
426 bool has_output = false;
427 bool has_merge = false;
428 GuestExecCaptureOutputMode output_mode;
429 g_autofree uint8_t *input = NULL;
430 size_t ninput = 0;
431
432 arglist.value = (char *)path;
433 arglist.next = has_arg ? arg : NULL;
434
435 if (input_data) {
436 input = qbase64_decode(input_data, -1, &ninput, errp);
437 if (!input) {
438 return NULL;
439 }
440 }
441
442 argv = guest_exec_get_args(&arglist, true);
443 envp = has_env ? guest_exec_get_args(env, false) : NULL;
444
445 flags = G_SPAWN_SEARCH_PATH | G_SPAWN_DO_NOT_REAP_CHILD |
446 G_SPAWN_SEARCH_PATH_FROM_ENVP;
447
448 output_mode = ga_parse_capture_output(capture_output);
449 switch (output_mode) {
450 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_NONE:
451 flags |= G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL;
452 break;
453 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_STDOUT:
454 has_output = true;
455 flags |= G_SPAWN_STDERR_TO_DEV_NULL;
456 break;
457 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_STDERR:
458 has_output = true;
459 flags |= G_SPAWN_STDOUT_TO_DEV_NULL;
460 break;
461 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_SEPARATED:
462 has_output = true;
463 break;
464 #if !defined(G_OS_WIN32)
465 case GUEST_EXEC_CAPTURE_OUTPUT_MODE_MERGED:
466 has_output = true;
467 has_merge = true;
468 break;
469 #endif
470 case GUEST_EXEC_CAPTURE_OUTPUT_MODE__MAX:
471 /* Silence warning; impossible branch */
472 break;
473 }
474
475 ret = g_spawn_async_with_pipes(NULL, argv, envp, flags,
476 guest_exec_task_setup, &has_merge, &pid, input_data ? &in_fd : NULL,
477 has_output ? &out_fd : NULL, has_output ? &err_fd : NULL, &gerr);
478 if (!ret) {
479 error_setg(errp, "%s", gerr->message);
480 g_error_free(gerr);
481 goto done;
482 }
483
484 ge = g_new0(GuestExec, 1);
485 ge->pid = gpid_to_int64(pid);
486
487 gei = guest_exec_info_add(pid);
488 gei->has_output = has_output;
489 g_child_watch_add(pid, guest_exec_child_watch, gei);
490
491 if (input_data) {
492 gei->in.data = g_steal_pointer(&input);
493 gei->in.size = ninput;
494 #ifdef G_OS_WIN32
495 in_ch = g_io_channel_win32_new_fd(in_fd);
496 #else
497 in_ch = g_io_channel_unix_new(in_fd);
498 #endif
499 g_io_channel_set_encoding(in_ch, NULL, NULL);
500 g_io_channel_set_buffered(in_ch, false);
501 g_io_channel_set_flags(in_ch, G_IO_FLAG_NONBLOCK, NULL);
502 g_io_channel_set_close_on_unref(in_ch, true);
503 g_io_add_watch(in_ch, G_IO_OUT, guest_exec_input_watch, &gei->in);
504 }
505
506 if (has_output) {
507 #ifdef G_OS_WIN32
508 out_ch = g_io_channel_win32_new_fd(out_fd);
509 err_ch = g_io_channel_win32_new_fd(err_fd);
510 #else
511 out_ch = g_io_channel_unix_new(out_fd);
512 err_ch = g_io_channel_unix_new(err_fd);
513 #endif
514 g_io_channel_set_encoding(out_ch, NULL, NULL);
515 g_io_channel_set_encoding(err_ch, NULL, NULL);
516 g_io_channel_set_buffered(out_ch, false);
517 g_io_channel_set_buffered(err_ch, false);
518 g_io_channel_set_close_on_unref(out_ch, true);
519 g_io_channel_set_close_on_unref(err_ch, true);
520 g_io_add_watch(out_ch, G_IO_IN | G_IO_HUP,
521 guest_exec_output_watch, &gei->out);
522 g_io_add_watch(err_ch, G_IO_IN | G_IO_HUP,
523 guest_exec_output_watch, &gei->err);
524 }
525
526 done:
527 g_free(argv);
528 g_free(envp);
529
530 return ge;
531 }
532
533 /* Convert GuestFileWhence (either a raw integer or an enum value) into
534 * the guest's SEEK_ constants. */
ga_parse_whence(GuestFileWhence * whence,Error ** errp)535 int ga_parse_whence(GuestFileWhence *whence, Error **errp)
536 {
537 /*
538 * Exploit the fact that we picked values to match QGA_SEEK_*;
539 * however, we have to use a temporary variable since the union
540 * members may have different size.
541 */
542 if (whence->type == QTYPE_QSTRING) {
543 int value = whence->u.name;
544 whence->type = QTYPE_QNUM;
545 whence->u.value = value;
546 }
547 switch (whence->u.value) {
548 case QGA_SEEK_SET:
549 return SEEK_SET;
550 case QGA_SEEK_CUR:
551 return SEEK_CUR;
552 case QGA_SEEK_END:
553 return SEEK_END;
554 }
555 error_setg(errp, "invalid whence code %"PRId64, whence->u.value);
556 return -1;
557 }
558
qmp_guest_get_host_name(Error ** errp)559 GuestHostName *qmp_guest_get_host_name(Error **errp)
560 {
561 GuestHostName *result = NULL;
562 g_autofree char *hostname = qga_get_host_name(errp);
563
564 /*
565 * We want to avoid using g_get_host_name() because that
566 * caches the result and we wouldn't reflect changes in the
567 * host name.
568 */
569
570 if (!hostname) {
571 hostname = g_strdup("localhost");
572 }
573
574 result = g_new0(GuestHostName, 1);
575 result->host_name = g_steal_pointer(&hostname);
576 return result;
577 }
578
qmp_guest_get_timezone(Error ** errp)579 GuestTimezone *qmp_guest_get_timezone(Error **errp)
580 {
581 GuestTimezone *info = NULL;
582 GTimeZone *tz = NULL;
583 gint64 now = 0;
584 gint32 intv = 0;
585 gchar const *name = NULL;
586
587 info = g_new0(GuestTimezone, 1);
588 tz = g_time_zone_new_local();
589 if (tz == NULL) {
590 error_setg(errp, "Couldn't retrieve local timezone");
591 goto error;
592 }
593
594 now = g_get_real_time() / G_USEC_PER_SEC;
595 intv = g_time_zone_find_interval(tz, G_TIME_TYPE_UNIVERSAL, now);
596 info->offset = g_time_zone_get_offset(tz, intv);
597 name = g_time_zone_get_abbreviation(tz, intv);
598 if (name != NULL) {
599 info->zone = g_strdup(name);
600 }
601 g_time_zone_unref(tz);
602
603 return info;
604
605 error:
606 g_free(info);
607 return NULL;
608 }
609
qmp_guest_file_read(int64_t handle,bool has_count,int64_t count,Error ** errp)610 GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,
611 int64_t count, Error **errp)
612 {
613 GuestFileHandle *gfh = guest_file_handle_find(handle, errp);
614 GuestFileRead *read_data;
615
616 if (!gfh) {
617 return NULL;
618 }
619 if (!has_count) {
620 count = QGA_READ_COUNT_DEFAULT;
621 } else if (count < 0 || count > GUEST_FILE_READ_COUNT_MAX) {
622 error_setg(errp, "value '%" PRId64 "' is invalid for argument count",
623 count);
624 return NULL;
625 }
626
627 read_data = guest_file_read_unsafe(gfh, count, errp);
628 if (!read_data) {
629 slog("guest-file-write failed, handle: %" PRId64, handle);
630 }
631
632 return read_data;
633 }
634
qmp_guest_get_time(Error ** errp)635 int64_t qmp_guest_get_time(Error **errp)
636 {
637 return g_get_real_time() * 1000;
638 }
639