Merge remote-tracking branch 'remotes/elmarco/tags/libslirp-pull-request' into staging
[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 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 = qatomic_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 && qatomic_mb_read(&gei->out.closed);
175 finished = finished && qatomic_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 qatomic_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 qatomic_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 qatomic_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 }