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1 /*
2 * QEMU Guest Agent
3 *
4 * Copyright IBM Corp. 2011
5 *
6 * Authors:
7 * Adam Litke <aglitke@linux.vnet.ibm.com>
8 * Michael Roth <mdroth@linux.vnet.ibm.com>
9 *
10 * This work is licensed under the terms of the GNU GPL, version 2 or later.
11 * See the COPYING file in the top-level directory.
12 */
13
14 #include "qemu/osdep.h"
15 #include <getopt.h>
16 #include <glib/gstdio.h>
17 #ifndef _WIN32
18 #include <syslog.h>
19 #include <sys/wait.h>
20 #endif
21 #include "qapi/qmp/json-parser.h"
22 #include "qapi/qmp/qdict.h"
23 #include "qapi/qmp/qjson.h"
24 #include "qapi/qmp/qstring.h"
25 #include "guest-agent-core.h"
26 #include "qemu/module.h"
27 #include "qga-qapi-commands.h"
28 #include "qapi/qmp/qerror.h"
29 #include "qapi/error.h"
30 #include "channel.h"
31 #include "qemu/bswap.h"
32 #include "qemu/help_option.h"
33 #include "qemu/sockets.h"
34 #include "qemu/systemd.h"
35 #include "qemu-version.h"
36 #ifdef _WIN32
37 #include "qga/service-win32.h"
38 #include "qga/vss-win32.h"
39 #endif
40 #ifdef __linux__
41 #include <linux/fs.h>
42 #ifdef FIFREEZE
43 #define CONFIG_FSFREEZE
44 #endif
45 #endif
46
47 #ifndef _WIN32
48 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
49 #define QGA_STATE_RELATIVE_DIR "run"
50 #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
51 #else
52 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
53 #define QGA_STATE_RELATIVE_DIR "qemu-ga"
54 #define QGA_SERIAL_PATH_DEFAULT "COM1"
55 #endif
56 #ifdef CONFIG_FSFREEZE
57 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
58 #endif
59 #define QGA_SENTINEL_BYTE 0xFF
60 #define QGA_CONF_DEFAULT CONFIG_QEMU_CONFDIR G_DIR_SEPARATOR_S "qemu-ga.conf"
61
62 static struct {
63 const char *state_dir;
64 const char *pidfile;
65 } dfl_pathnames;
66
67 typedef struct GAPersistentState {
68 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
69 int64_t fd_counter;
70 } GAPersistentState;
71
72 struct GAState {
73 JSONMessageParser parser;
74 GMainLoop *main_loop;
75 GAChannel *channel;
76 bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
77 GACommandState *command_state;
78 GLogLevelFlags log_level;
79 FILE *log_file;
80 bool logging_enabled;
81 #ifdef _WIN32
82 GAService service;
83 #endif
84 bool delimit_response;
85 bool frozen;
86 GList *blacklist;
87 char *state_filepath_isfrozen;
88 struct {
89 const char *log_filepath;
90 const char *pid_filepath;
91 } deferred_options;
92 #ifdef CONFIG_FSFREEZE
93 const char *fsfreeze_hook;
94 #endif
95 gchar *pstate_filepath;
96 GAPersistentState pstate;
97 };
98
99 struct GAState *ga_state;
100 QmpCommandList ga_commands;
101
102 /* commands that are safe to issue while filesystems are frozen */
103 static const char *ga_freeze_whitelist[] = {
104 "guest-ping",
105 "guest-info",
106 "guest-sync",
107 "guest-sync-delimited",
108 "guest-fsfreeze-status",
109 "guest-fsfreeze-thaw",
110 NULL
111 };
112
113 #ifdef _WIN32
114 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
115 LPVOID ctx);
116 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
117 #endif
118
119 static void
120 init_dfl_pathnames(void)
121 {
122 g_assert(dfl_pathnames.state_dir == NULL);
123 g_assert(dfl_pathnames.pidfile == NULL);
124 dfl_pathnames.state_dir = qemu_get_local_state_pathname(
125 QGA_STATE_RELATIVE_DIR);
126 dfl_pathnames.pidfile = qemu_get_local_state_pathname(
127 QGA_STATE_RELATIVE_DIR G_DIR_SEPARATOR_S "qemu-ga.pid");
128 }
129
130 static void quit_handler(int sig)
131 {
132 /* if we're frozen, don't exit unless we're absolutely forced to,
133 * because it's basically impossible for graceful exit to complete
134 * unless all log/pid files are on unfreezable filesystems. there's
135 * also a very likely chance killing the agent before unfreezing
136 * the filesystems is a mistake (or will be viewed as one later).
137 * On Windows the freeze interval is limited to 10 seconds, so
138 * we should quit, but first we should wait for the timeout, thaw
139 * the filesystem and quit.
140 */
141 if (ga_is_frozen(ga_state)) {
142 #ifdef _WIN32
143 int i = 0;
144 Error *err = NULL;
145 HANDLE hEventTimeout;
146
147 g_debug("Thawing filesystems before exiting");
148
149 hEventTimeout = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_TIMEOUT);
150 if (hEventTimeout) {
151 WaitForSingleObject(hEventTimeout, 0);
152 CloseHandle(hEventTimeout);
153 }
154 qga_vss_fsfreeze(&i, false, NULL, &err);
155 if (err) {
156 g_debug("Error unfreezing filesystems prior to exiting: %s",
157 error_get_pretty(err));
158 error_free(err);
159 }
160 #else
161 return;
162 #endif
163 }
164 g_debug("received signal num %d, quitting", sig);
165
166 if (g_main_loop_is_running(ga_state->main_loop)) {
167 g_main_loop_quit(ga_state->main_loop);
168 }
169 }
170
171 #ifndef _WIN32
172 static gboolean register_signal_handlers(void)
173 {
174 struct sigaction sigact;
175 int ret;
176
177 memset(&sigact, 0, sizeof(struct sigaction));
178 sigact.sa_handler = quit_handler;
179
180 ret = sigaction(SIGINT, &sigact, NULL);
181 if (ret == -1) {
182 g_error("error configuring signal handler: %s", strerror(errno));
183 }
184 ret = sigaction(SIGTERM, &sigact, NULL);
185 if (ret == -1) {
186 g_error("error configuring signal handler: %s", strerror(errno));
187 }
188
189 sigact.sa_handler = SIG_IGN;
190 if (sigaction(SIGPIPE, &sigact, NULL) != 0) {
191 g_error("error configuring SIGPIPE signal handler: %s",
192 strerror(errno));
193 }
194
195 return true;
196 }
197
198 /* TODO: use this in place of all post-fork() fclose(std*) callers */
199 void reopen_fd_to_null(int fd)
200 {
201 int nullfd;
202
203 nullfd = open("/dev/null", O_RDWR);
204 if (nullfd < 0) {
205 return;
206 }
207
208 dup2(nullfd, fd);
209
210 if (nullfd != fd) {
211 close(nullfd);
212 }
213 }
214 #endif
215
216 static void usage(const char *cmd)
217 {
218 printf(
219 "Usage: %s [-m <method> -p <path>] [<options>]\n"
220 "QEMU Guest Agent " QEMU_FULL_VERSION "\n"
221 QEMU_COPYRIGHT "\n"
222 "\n"
223 " -m, --method transport method: one of unix-listen, virtio-serial,\n"
224 " isa-serial, or vsock-listen (virtio-serial is the default)\n"
225 " -p, --path device/socket path (the default for virtio-serial is:\n"
226 " %s,\n"
227 " the default for isa-serial is:\n"
228 " %s)\n"
229 " -l, --logfile set logfile path, logs to stderr by default\n"
230 " -f, --pidfile specify pidfile (default is %s)\n"
231 #ifdef CONFIG_FSFREEZE
232 " -F, --fsfreeze-hook\n"
233 " enable fsfreeze hook. Accepts an optional argument that\n"
234 " specifies script to run on freeze/thaw. Script will be\n"
235 " called with 'freeze'/'thaw' arguments accordingly.\n"
236 " (default is %s)\n"
237 " If using -F with an argument, do not follow -F with a\n"
238 " space.\n"
239 " (for example: -F/var/run/fsfreezehook.sh)\n"
240 #endif
241 " -t, --statedir specify dir to store state information (absolute paths\n"
242 " only, default is %s)\n"
243 " -v, --verbose log extra debugging information\n"
244 " -V, --version print version information and exit\n"
245 " -d, --daemonize become a daemon\n"
246 #ifdef _WIN32
247 " -s, --service service commands: install, uninstall, vss-install, vss-uninstall\n"
248 #endif
249 " -b, --blacklist comma-separated list of RPCs to disable (no spaces, \"?\"\n"
250 " to list available RPCs)\n"
251 " -D, --dump-conf dump a qemu-ga config file based on current config\n"
252 " options / command-line parameters to stdout\n"
253 " -h, --help display this help and exit\n"
254 "\n"
255 QEMU_HELP_BOTTOM "\n"
256 , cmd, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT,
257 dfl_pathnames.pidfile,
258 #ifdef CONFIG_FSFREEZE
259 QGA_FSFREEZE_HOOK_DEFAULT,
260 #endif
261 dfl_pathnames.state_dir);
262 }
263
264 static const char *ga_log_level_str(GLogLevelFlags level)
265 {
266 switch (level & G_LOG_LEVEL_MASK) {
267 case G_LOG_LEVEL_ERROR:
268 return "error";
269 case G_LOG_LEVEL_CRITICAL:
270 return "critical";
271 case G_LOG_LEVEL_WARNING:
272 return "warning";
273 case G_LOG_LEVEL_MESSAGE:
274 return "message";
275 case G_LOG_LEVEL_INFO:
276 return "info";
277 case G_LOG_LEVEL_DEBUG:
278 return "debug";
279 default:
280 return "user";
281 }
282 }
283
284 bool ga_logging_enabled(GAState *s)
285 {
286 return s->logging_enabled;
287 }
288
289 void ga_disable_logging(GAState *s)
290 {
291 s->logging_enabled = false;
292 }
293
294 void ga_enable_logging(GAState *s)
295 {
296 s->logging_enabled = true;
297 }
298
299 static void ga_log(const gchar *domain, GLogLevelFlags level,
300 const gchar *msg, gpointer opaque)
301 {
302 GAState *s = opaque;
303 GTimeVal time;
304 const char *level_str = ga_log_level_str(level);
305
306 if (!ga_logging_enabled(s)) {
307 return;
308 }
309
310 level &= G_LOG_LEVEL_MASK;
311 #ifndef _WIN32
312 if (g_strcmp0(domain, "syslog") == 0) {
313 syslog(LOG_INFO, "%s: %s", level_str, msg);
314 } else if (level & s->log_level) {
315 #else
316 if (level & s->log_level) {
317 #endif
318 g_get_current_time(&time);
319 fprintf(s->log_file,
320 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
321 fflush(s->log_file);
322 }
323 }
324
325 void ga_set_response_delimited(GAState *s)
326 {
327 s->delimit_response = true;
328 }
329
330 static FILE *ga_open_logfile(const char *logfile)
331 {
332 FILE *f;
333
334 f = fopen(logfile, "a");
335 if (!f) {
336 return NULL;
337 }
338
339 qemu_set_cloexec(fileno(f));
340 return f;
341 }
342
343 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
344 {
345 return strcmp(str1, str2);
346 }
347
348 /* disable commands that aren't safe for fsfreeze */
349 static void ga_disable_non_whitelisted(QmpCommand *cmd, void *opaque)
350 {
351 bool whitelisted = false;
352 int i = 0;
353 const char *name = qmp_command_name(cmd);
354
355 while (ga_freeze_whitelist[i] != NULL) {
356 if (strcmp(name, ga_freeze_whitelist[i]) == 0) {
357 whitelisted = true;
358 }
359 i++;
360 }
361 if (!whitelisted) {
362 g_debug("disabling command: %s", name);
363 qmp_disable_command(&ga_commands, name);
364 }
365 }
366
367 /* [re-]enable all commands, except those explicitly blacklisted by user */
368 static void ga_enable_non_blacklisted(QmpCommand *cmd, void *opaque)
369 {
370 GList *blacklist = opaque;
371 const char *name = qmp_command_name(cmd);
372
373 if (g_list_find_custom(blacklist, name, ga_strcmp) == NULL &&
374 !qmp_command_is_enabled(cmd)) {
375 g_debug("enabling command: %s", name);
376 qmp_enable_command(&ga_commands, name);
377 }
378 }
379
380 static bool ga_create_file(const char *path)
381 {
382 int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
383 if (fd == -1) {
384 g_warning("unable to open/create file %s: %s", path, strerror(errno));
385 return false;
386 }
387 close(fd);
388 return true;
389 }
390
391 static bool ga_delete_file(const char *path)
392 {
393 int ret = unlink(path);
394 if (ret == -1) {
395 g_warning("unable to delete file: %s: %s", path, strerror(errno));
396 return false;
397 }
398
399 return true;
400 }
401
402 bool ga_is_frozen(GAState *s)
403 {
404 return s->frozen;
405 }
406
407 void ga_set_frozen(GAState *s)
408 {
409 if (ga_is_frozen(s)) {
410 return;
411 }
412 /* disable all non-whitelisted (for frozen state) commands */
413 qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
414 g_warning("disabling logging due to filesystem freeze");
415 ga_disable_logging(s);
416 s->frozen = true;
417 if (!ga_create_file(s->state_filepath_isfrozen)) {
418 g_warning("unable to create %s, fsfreeze may not function properly",
419 s->state_filepath_isfrozen);
420 }
421 }
422
423 void ga_unset_frozen(GAState *s)
424 {
425 if (!ga_is_frozen(s)) {
426 return;
427 }
428
429 /* if we delayed creation/opening of pid/log files due to being
430 * in a frozen state at start up, do it now
431 */
432 if (s->deferred_options.log_filepath) {
433 s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
434 if (!s->log_file) {
435 s->log_file = stderr;
436 }
437 s->deferred_options.log_filepath = NULL;
438 }
439 ga_enable_logging(s);
440 g_warning("logging re-enabled due to filesystem unfreeze");
441 if (s->deferred_options.pid_filepath) {
442 Error *err = NULL;
443
444 if (!qemu_write_pidfile(s->deferred_options.pid_filepath, &err)) {
445 g_warning("%s", error_get_pretty(err));
446 error_free(err);
447 }
448 s->deferred_options.pid_filepath = NULL;
449 }
450
451 /* enable all disabled, non-blacklisted commands */
452 qmp_for_each_command(&ga_commands, ga_enable_non_blacklisted, s->blacklist);
453 s->frozen = false;
454 if (!ga_delete_file(s->state_filepath_isfrozen)) {
455 g_warning("unable to delete %s, fsfreeze may not function properly",
456 s->state_filepath_isfrozen);
457 }
458 }
459
460 #ifdef CONFIG_FSFREEZE
461 const char *ga_fsfreeze_hook(GAState *s)
462 {
463 return s->fsfreeze_hook;
464 }
465 #endif
466
467 static void become_daemon(const char *pidfile)
468 {
469 #ifndef _WIN32
470 pid_t pid, sid;
471
472 pid = fork();
473 if (pid < 0) {
474 exit(EXIT_FAILURE);
475 }
476 if (pid > 0) {
477 exit(EXIT_SUCCESS);
478 }
479
480 if (pidfile) {
481 Error *err = NULL;
482
483 if (!qemu_write_pidfile(pidfile, &err)) {
484 g_critical("%s", error_get_pretty(err));
485 error_free(err);
486 exit(EXIT_FAILURE);
487 }
488 }
489
490 umask(S_IRWXG | S_IRWXO);
491 sid = setsid();
492 if (sid < 0) {
493 goto fail;
494 }
495 if ((chdir("/")) < 0) {
496 goto fail;
497 }
498
499 reopen_fd_to_null(STDIN_FILENO);
500 reopen_fd_to_null(STDOUT_FILENO);
501 reopen_fd_to_null(STDERR_FILENO);
502 return;
503
504 fail:
505 if (pidfile) {
506 unlink(pidfile);
507 }
508 g_critical("failed to daemonize");
509 exit(EXIT_FAILURE);
510 #endif
511 }
512
513 static int send_response(GAState *s, QDict *payload)
514 {
515 const char *buf;
516 QString *payload_qstr, *response_qstr;
517 GIOStatus status;
518
519 g_assert(payload && s->channel);
520
521 payload_qstr = qobject_to_json(QOBJECT(payload));
522 if (!payload_qstr) {
523 return -EINVAL;
524 }
525
526 if (s->delimit_response) {
527 s->delimit_response = false;
528 response_qstr = qstring_new();
529 qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
530 qstring_append(response_qstr, qstring_get_str(payload_qstr));
531 qobject_unref(payload_qstr);
532 } else {
533 response_qstr = payload_qstr;
534 }
535
536 qstring_append_chr(response_qstr, '\n');
537 buf = qstring_get_str(response_qstr);
538 status = ga_channel_write_all(s->channel, buf, strlen(buf));
539 qobject_unref(response_qstr);
540 if (status != G_IO_STATUS_NORMAL) {
541 return -EIO;
542 }
543
544 return 0;
545 }
546
547 static void process_command(GAState *s, QDict *req)
548 {
549 QDict *rsp;
550 int ret;
551
552 g_assert(req);
553 g_debug("processing command");
554 rsp = qmp_dispatch(&ga_commands, QOBJECT(req), false);
555 if (rsp) {
556 ret = send_response(s, rsp);
557 if (ret < 0) {
558 g_warning("error sending response: %s", strerror(-ret));
559 }
560 qobject_unref(rsp);
561 }
562 }
563
564 /* handle requests/control events coming in over the channel */
565 static void process_event(void *opaque, QObject *obj, Error *err)
566 {
567 GAState *s = opaque;
568 QDict *req, *rsp;
569 int ret;
570
571 g_debug("process_event: called");
572 assert(!obj != !err);
573 if (err) {
574 goto err;
575 }
576 req = qobject_to(QDict, obj);
577 if (!req) {
578 error_setg(&err, "Input must be a JSON object");
579 goto err;
580 }
581 if (!qdict_haskey(req, "execute")) {
582 g_warning("unrecognized payload format");
583 error_setg(&err, QERR_UNSUPPORTED);
584 goto err;
585 }
586
587 process_command(s, req);
588 qobject_unref(obj);
589 return;
590
591 err:
592 g_warning("failed to parse event: %s", error_get_pretty(err));
593 rsp = qmp_error_response(err);
594 ret = send_response(s, rsp);
595 if (ret < 0) {
596 g_warning("error sending error response: %s", strerror(-ret));
597 }
598 qobject_unref(rsp);
599 qobject_unref(obj);
600 }
601
602 /* false return signals GAChannel to close the current client connection */
603 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
604 {
605 GAState *s = data;
606 gchar buf[QGA_READ_COUNT_DEFAULT+1];
607 gsize count;
608 GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
609 switch (status) {
610 case G_IO_STATUS_ERROR:
611 g_warning("error reading channel");
612 return false;
613 case G_IO_STATUS_NORMAL:
614 buf[count] = 0;
615 g_debug("read data, count: %d, data: %s", (int)count, buf);
616 json_message_parser_feed(&s->parser, (char *)buf, (int)count);
617 break;
618 case G_IO_STATUS_EOF:
619 g_debug("received EOF");
620 if (!s->virtio) {
621 return false;
622 }
623 /* fall through */
624 case G_IO_STATUS_AGAIN:
625 /* virtio causes us to spin here when no process is attached to
626 * host-side chardev. sleep a bit to mitigate this
627 */
628 if (s->virtio) {
629 usleep(100*1000);
630 }
631 return true;
632 default:
633 g_warning("unknown channel read status, closing");
634 return false;
635 }
636 return true;
637 }
638
639 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path,
640 int listen_fd)
641 {
642 GAChannelMethod channel_method;
643
644 if (strcmp(method, "virtio-serial") == 0) {
645 s->virtio = true; /* virtio requires special handling in some cases */
646 channel_method = GA_CHANNEL_VIRTIO_SERIAL;
647 } else if (strcmp(method, "isa-serial") == 0) {
648 channel_method = GA_CHANNEL_ISA_SERIAL;
649 } else if (strcmp(method, "unix-listen") == 0) {
650 channel_method = GA_CHANNEL_UNIX_LISTEN;
651 } else if (strcmp(method, "vsock-listen") == 0) {
652 channel_method = GA_CHANNEL_VSOCK_LISTEN;
653 } else {
654 g_critical("unsupported channel method/type: %s", method);
655 return false;
656 }
657
658 s->channel = ga_channel_new(channel_method, path, listen_fd,
659 channel_event_cb, s);
660 if (!s->channel) {
661 g_critical("failed to create guest agent channel");
662 return false;
663 }
664
665 return true;
666 }
667
668 #ifdef _WIN32
669 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
670 LPVOID ctx)
671 {
672 DWORD ret = NO_ERROR;
673 GAService *service = &ga_state->service;
674
675 switch (ctrl)
676 {
677 case SERVICE_CONTROL_STOP:
678 case SERVICE_CONTROL_SHUTDOWN:
679 quit_handler(SIGTERM);
680 service->status.dwCurrentState = SERVICE_STOP_PENDING;
681 SetServiceStatus(service->status_handle, &service->status);
682 break;
683
684 default:
685 ret = ERROR_CALL_NOT_IMPLEMENTED;
686 }
687 return ret;
688 }
689
690 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
691 {
692 GAService *service = &ga_state->service;
693
694 service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
695 service_ctrl_handler, NULL);
696
697 if (service->status_handle == 0) {
698 g_critical("Failed to register extended requests function!\n");
699 return;
700 }
701
702 service->status.dwServiceType = SERVICE_WIN32;
703 service->status.dwCurrentState = SERVICE_RUNNING;
704 service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
705 service->status.dwWin32ExitCode = NO_ERROR;
706 service->status.dwServiceSpecificExitCode = NO_ERROR;
707 service->status.dwCheckPoint = 0;
708 service->status.dwWaitHint = 0;
709 SetServiceStatus(service->status_handle, &service->status);
710
711 g_main_loop_run(ga_state->main_loop);
712
713 service->status.dwCurrentState = SERVICE_STOPPED;
714 SetServiceStatus(service->status_handle, &service->status);
715 }
716 #endif
717
718 static void set_persistent_state_defaults(GAPersistentState *pstate)
719 {
720 g_assert(pstate);
721 pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
722 }
723
724 static void persistent_state_from_keyfile(GAPersistentState *pstate,
725 GKeyFile *keyfile)
726 {
727 g_assert(pstate);
728 g_assert(keyfile);
729 /* if any fields are missing, either because the file was tampered with
730 * by agents of chaos, or because the field wasn't present at the time the
731 * file was created, the best we can ever do is start over with the default
732 * values. so load them now, and ignore any errors in accessing key-value
733 * pairs
734 */
735 set_persistent_state_defaults(pstate);
736
737 if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
738 pstate->fd_counter =
739 g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
740 }
741 }
742
743 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
744 GKeyFile *keyfile)
745 {
746 g_assert(pstate);
747 g_assert(keyfile);
748
749 g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
750 }
751
752 static gboolean write_persistent_state(const GAPersistentState *pstate,
753 const gchar *path)
754 {
755 GKeyFile *keyfile = g_key_file_new();
756 GError *gerr = NULL;
757 gboolean ret = true;
758 gchar *data = NULL;
759 gsize data_len;
760
761 g_assert(pstate);
762
763 persistent_state_to_keyfile(pstate, keyfile);
764 data = g_key_file_to_data(keyfile, &data_len, &gerr);
765 if (gerr) {
766 g_critical("failed to convert persistent state to string: %s",
767 gerr->message);
768 ret = false;
769 goto out;
770 }
771
772 g_file_set_contents(path, data, data_len, &gerr);
773 if (gerr) {
774 g_critical("failed to write persistent state to %s: %s",
775 path, gerr->message);
776 ret = false;
777 goto out;
778 }
779
780 out:
781 if (gerr) {
782 g_error_free(gerr);
783 }
784 if (keyfile) {
785 g_key_file_free(keyfile);
786 }
787 g_free(data);
788 return ret;
789 }
790
791 static gboolean read_persistent_state(GAPersistentState *pstate,
792 const gchar *path, gboolean frozen)
793 {
794 GKeyFile *keyfile = NULL;
795 GError *gerr = NULL;
796 struct stat st;
797 gboolean ret = true;
798
799 g_assert(pstate);
800
801 if (stat(path, &st) == -1) {
802 /* it's okay if state file doesn't exist, but any other error
803 * indicates a permissions issue or some other misconfiguration
804 * that we likely won't be able to recover from.
805 */
806 if (errno != ENOENT) {
807 g_critical("unable to access state file at path %s: %s",
808 path, strerror(errno));
809 ret = false;
810 goto out;
811 }
812
813 /* file doesn't exist. initialize state to default values and
814 * attempt to save now. (we could wait till later when we have
815 * modified state we need to commit, but if there's a problem,
816 * such as a missing parent directory, we want to catch it now)
817 *
818 * there is a potential scenario where someone either managed to
819 * update the agent from a version that didn't use a key store
820 * while qemu-ga thought the filesystem was frozen, or
821 * deleted the key store prior to issuing a fsfreeze, prior
822 * to restarting the agent. in this case we go ahead and defer
823 * initial creation till we actually have modified state to
824 * write, otherwise fail to recover from freeze.
825 */
826 set_persistent_state_defaults(pstate);
827 if (!frozen) {
828 ret = write_persistent_state(pstate, path);
829 if (!ret) {
830 g_critical("unable to create state file at path %s", path);
831 ret = false;
832 goto out;
833 }
834 }
835 ret = true;
836 goto out;
837 }
838
839 keyfile = g_key_file_new();
840 g_key_file_load_from_file(keyfile, path, 0, &gerr);
841 if (gerr) {
842 g_critical("error loading persistent state from path: %s, %s",
843 path, gerr->message);
844 ret = false;
845 goto out;
846 }
847
848 persistent_state_from_keyfile(pstate, keyfile);
849
850 out:
851 if (keyfile) {
852 g_key_file_free(keyfile);
853 }
854 if (gerr) {
855 g_error_free(gerr);
856 }
857
858 return ret;
859 }
860
861 int64_t ga_get_fd_handle(GAState *s, Error **errp)
862 {
863 int64_t handle;
864
865 g_assert(s->pstate_filepath);
866 /* we blacklist commands and avoid operations that potentially require
867 * writing to disk when we're in a frozen state. this includes opening
868 * new files, so we should never get here in that situation
869 */
870 g_assert(!ga_is_frozen(s));
871
872 handle = s->pstate.fd_counter++;
873
874 /* This should never happen on a reasonable timeframe, as guest-file-open
875 * would have to be issued 2^63 times */
876 if (s->pstate.fd_counter == INT64_MAX) {
877 abort();
878 }
879
880 if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
881 error_setg(errp, "failed to commit persistent state to disk");
882 return -1;
883 }
884
885 return handle;
886 }
887
888 static void ga_print_cmd(QmpCommand *cmd, void *opaque)
889 {
890 printf("%s\n", qmp_command_name(cmd));
891 }
892
893 static GList *split_list(const gchar *str, const gchar *delim)
894 {
895 GList *list = NULL;
896 int i;
897 gchar **strv;
898
899 strv = g_strsplit(str, delim, -1);
900 for (i = 0; strv[i]; i++) {
901 list = g_list_prepend(list, strv[i]);
902 }
903 g_free(strv);
904
905 return list;
906 }
907
908 typedef struct GAConfig {
909 char *channel_path;
910 char *method;
911 char *log_filepath;
912 char *pid_filepath;
913 #ifdef CONFIG_FSFREEZE
914 char *fsfreeze_hook;
915 #endif
916 char *state_dir;
917 #ifdef _WIN32
918 const char *service;
919 #endif
920 gchar *bliststr; /* blacklist may point to this string */
921 GList *blacklist;
922 int daemonize;
923 GLogLevelFlags log_level;
924 int dumpconf;
925 } GAConfig;
926
927 static void config_load(GAConfig *config)
928 {
929 GError *gerr = NULL;
930 GKeyFile *keyfile;
931 const char *conf = g_getenv("QGA_CONF") ?: QGA_CONF_DEFAULT;
932
933 /* read system config */
934 keyfile = g_key_file_new();
935 if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
936 goto end;
937 }
938 if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
939 config->daemonize =
940 g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
941 }
942 if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
943 config->method =
944 g_key_file_get_string(keyfile, "general", "method", &gerr);
945 }
946 if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
947 config->channel_path =
948 g_key_file_get_string(keyfile, "general", "path", &gerr);
949 }
950 if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
951 config->log_filepath =
952 g_key_file_get_string(keyfile, "general", "logfile", &gerr);
953 }
954 if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
955 config->pid_filepath =
956 g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
957 }
958 #ifdef CONFIG_FSFREEZE
959 if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
960 config->fsfreeze_hook =
961 g_key_file_get_string(keyfile,
962 "general", "fsfreeze-hook", &gerr);
963 }
964 #endif
965 if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
966 config->state_dir =
967 g_key_file_get_string(keyfile, "general", "statedir", &gerr);
968 }
969 if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
970 g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
971 /* enable all log levels */
972 config->log_level = G_LOG_LEVEL_MASK;
973 }
974 if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
975 config->bliststr =
976 g_key_file_get_string(keyfile, "general", "blacklist", &gerr);
977 config->blacklist = g_list_concat(config->blacklist,
978 split_list(config->bliststr, ","));
979 }
980
981 end:
982 g_key_file_free(keyfile);
983 if (gerr &&
984 !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
985 g_critical("error loading configuration from path: %s, %s",
986 QGA_CONF_DEFAULT, gerr->message);
987 exit(EXIT_FAILURE);
988 }
989 g_clear_error(&gerr);
990 }
991
992 static gchar *list_join(GList *list, const gchar separator)
993 {
994 GString *str = g_string_new("");
995
996 while (list) {
997 str = g_string_append(str, (gchar *)list->data);
998 list = g_list_next(list);
999 if (list) {
1000 str = g_string_append_c(str, separator);
1001 }
1002 }
1003
1004 return g_string_free(str, FALSE);
1005 }
1006
1007 static void config_dump(GAConfig *config)
1008 {
1009 GError *error = NULL;
1010 GKeyFile *keyfile;
1011 gchar *tmp;
1012
1013 keyfile = g_key_file_new();
1014 g_assert(keyfile);
1015
1016 g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1017 g_key_file_set_string(keyfile, "general", "method", config->method);
1018 if (config->channel_path) {
1019 g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1020 }
1021 if (config->log_filepath) {
1022 g_key_file_set_string(keyfile, "general", "logfile",
1023 config->log_filepath);
1024 }
1025 g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1026 #ifdef CONFIG_FSFREEZE
1027 if (config->fsfreeze_hook) {
1028 g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1029 config->fsfreeze_hook);
1030 }
1031 #endif
1032 g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1033 g_key_file_set_boolean(keyfile, "general", "verbose",
1034 config->log_level == G_LOG_LEVEL_MASK);
1035 tmp = list_join(config->blacklist, ',');
1036 g_key_file_set_string(keyfile, "general", "blacklist", tmp);
1037 g_free(tmp);
1038
1039 tmp = g_key_file_to_data(keyfile, NULL, &error);
1040 if (error) {
1041 g_critical("Failed to dump keyfile: %s", error->message);
1042 g_clear_error(&error);
1043 } else {
1044 printf("%s", tmp);
1045 }
1046
1047 g_free(tmp);
1048 g_key_file_free(keyfile);
1049 }
1050
1051 static void config_parse(GAConfig *config, int argc, char **argv)
1052 {
1053 const char *sopt = "hVvdm:p:l:f:F::b:s:t:D";
1054 int opt_ind = 0, ch;
1055 const struct option lopt[] = {
1056 { "help", 0, NULL, 'h' },
1057 { "version", 0, NULL, 'V' },
1058 { "dump-conf", 0, NULL, 'D' },
1059 { "logfile", 1, NULL, 'l' },
1060 { "pidfile", 1, NULL, 'f' },
1061 #ifdef CONFIG_FSFREEZE
1062 { "fsfreeze-hook", 2, NULL, 'F' },
1063 #endif
1064 { "verbose", 0, NULL, 'v' },
1065 { "method", 1, NULL, 'm' },
1066 { "path", 1, NULL, 'p' },
1067 { "daemonize", 0, NULL, 'd' },
1068 { "blacklist", 1, NULL, 'b' },
1069 #ifdef _WIN32
1070 { "service", 1, NULL, 's' },
1071 #endif
1072 { "statedir", 1, NULL, 't' },
1073 { NULL, 0, NULL, 0 }
1074 };
1075
1076 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1077 switch (ch) {
1078 case 'm':
1079 g_free(config->method);
1080 config->method = g_strdup(optarg);
1081 break;
1082 case 'p':
1083 g_free(config->channel_path);
1084 config->channel_path = g_strdup(optarg);
1085 break;
1086 case 'l':
1087 g_free(config->log_filepath);
1088 config->log_filepath = g_strdup(optarg);
1089 break;
1090 case 'f':
1091 g_free(config->pid_filepath);
1092 config->pid_filepath = g_strdup(optarg);
1093 break;
1094 #ifdef CONFIG_FSFREEZE
1095 case 'F':
1096 g_free(config->fsfreeze_hook);
1097 config->fsfreeze_hook = g_strdup(optarg ?: QGA_FSFREEZE_HOOK_DEFAULT);
1098 break;
1099 #endif
1100 case 't':
1101 g_free(config->state_dir);
1102 config->state_dir = g_strdup(optarg);
1103 break;
1104 case 'v':
1105 /* enable all log levels */
1106 config->log_level = G_LOG_LEVEL_MASK;
1107 break;
1108 case 'V':
1109 printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1110 exit(EXIT_SUCCESS);
1111 case 'd':
1112 config->daemonize = 1;
1113 break;
1114 case 'D':
1115 config->dumpconf = 1;
1116 break;
1117 case 'b': {
1118 if (is_help_option(optarg)) {
1119 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1120 exit(EXIT_SUCCESS);
1121 }
1122 config->blacklist = g_list_concat(config->blacklist,
1123 split_list(optarg, ","));
1124 break;
1125 }
1126 #ifdef _WIN32
1127 case 's':
1128 config->service = optarg;
1129 if (strcmp(config->service, "install") == 0) {
1130 if (ga_install_vss_provider()) {
1131 exit(EXIT_FAILURE);
1132 }
1133 if (ga_install_service(config->channel_path,
1134 config->log_filepath, config->state_dir)) {
1135 exit(EXIT_FAILURE);
1136 }
1137 exit(EXIT_SUCCESS);
1138 } else if (strcmp(config->service, "uninstall") == 0) {
1139 ga_uninstall_vss_provider();
1140 exit(ga_uninstall_service());
1141 } else if (strcmp(config->service, "vss-install") == 0) {
1142 if (ga_install_vss_provider()) {
1143 exit(EXIT_FAILURE);
1144 }
1145 exit(EXIT_SUCCESS);
1146 } else if (strcmp(config->service, "vss-uninstall") == 0) {
1147 ga_uninstall_vss_provider();
1148 exit(EXIT_SUCCESS);
1149 } else {
1150 printf("Unknown service command.\n");
1151 exit(EXIT_FAILURE);
1152 }
1153 break;
1154 #endif
1155 case 'h':
1156 usage(argv[0]);
1157 exit(EXIT_SUCCESS);
1158 case '?':
1159 g_print("Unknown option, try '%s --help' for more information.\n",
1160 argv[0]);
1161 exit(EXIT_FAILURE);
1162 }
1163 }
1164 }
1165
1166 static void config_free(GAConfig *config)
1167 {
1168 g_free(config->method);
1169 g_free(config->log_filepath);
1170 g_free(config->pid_filepath);
1171 g_free(config->state_dir);
1172 g_free(config->channel_path);
1173 g_free(config->bliststr);
1174 #ifdef CONFIG_FSFREEZE
1175 g_free(config->fsfreeze_hook);
1176 #endif
1177 g_list_free_full(config->blacklist, g_free);
1178 g_free(config);
1179 }
1180
1181 static bool check_is_frozen(GAState *s)
1182 {
1183 #ifndef _WIN32
1184 /* check if a previous instance of qemu-ga exited with filesystems' state
1185 * marked as frozen. this could be a stale value (a non-qemu-ga process
1186 * or reboot may have since unfrozen them), but better to require an
1187 * uneeded unfreeze than to risk hanging on start-up
1188 */
1189 struct stat st;
1190 if (stat(s->state_filepath_isfrozen, &st) == -1) {
1191 /* it's okay if the file doesn't exist, but if we can't access for
1192 * some other reason, such as permissions, there's a configuration
1193 * that needs to be addressed. so just bail now before we get into
1194 * more trouble later
1195 */
1196 if (errno != ENOENT) {
1197 g_critical("unable to access state file at path %s: %s",
1198 s->state_filepath_isfrozen, strerror(errno));
1199 return EXIT_FAILURE;
1200 }
1201 } else {
1202 g_warning("previous instance appears to have exited with frozen"
1203 " filesystems. deferring logging/pidfile creation and"
1204 " disabling non-fsfreeze-safe commands until"
1205 " guest-fsfreeze-thaw is issued, or filesystems are"
1206 " manually unfrozen and the file %s is removed",
1207 s->state_filepath_isfrozen);
1208 return true;
1209 }
1210 #endif
1211 return false;
1212 }
1213
1214 static int run_agent(GAState *s, GAConfig *config, int socket_activation)
1215 {
1216 ga_state = s;
1217
1218 g_log_set_default_handler(ga_log, s);
1219 g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1220 ga_enable_logging(s);
1221
1222 #ifdef _WIN32
1223 /* On win32 the state directory is application specific (be it the default
1224 * or a user override). We got past the command line parsing; let's create
1225 * the directory (with any intermediate directories). If we run into an
1226 * error later on, we won't try to clean up the directory, it is considered
1227 * persistent.
1228 */
1229 if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1230 g_critical("unable to create (an ancestor of) the state directory"
1231 " '%s': %s", config->state_dir, strerror(errno));
1232 return EXIT_FAILURE;
1233 }
1234 #endif
1235
1236 if (ga_is_frozen(s)) {
1237 if (config->daemonize) {
1238 /* delay opening/locking of pidfile till filesystems are unfrozen */
1239 s->deferred_options.pid_filepath = config->pid_filepath;
1240 become_daemon(NULL);
1241 }
1242 if (config->log_filepath) {
1243 /* delay opening the log file till filesystems are unfrozen */
1244 s->deferred_options.log_filepath = config->log_filepath;
1245 }
1246 ga_disable_logging(s);
1247 qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
1248 } else {
1249 if (config->daemonize) {
1250 become_daemon(config->pid_filepath);
1251 }
1252 if (config->log_filepath) {
1253 FILE *log_file = ga_open_logfile(config->log_filepath);
1254 if (!log_file) {
1255 g_critical("unable to open specified log file: %s",
1256 strerror(errno));
1257 return EXIT_FAILURE;
1258 }
1259 s->log_file = log_file;
1260 }
1261 }
1262
1263 /* load persistent state from disk */
1264 if (!read_persistent_state(&s->pstate,
1265 s->pstate_filepath,
1266 ga_is_frozen(s))) {
1267 g_critical("failed to load persistent state");
1268 return EXIT_FAILURE;
1269 }
1270
1271 config->blacklist = ga_command_blacklist_init(config->blacklist);
1272 if (config->blacklist) {
1273 GList *l = config->blacklist;
1274 s->blacklist = config->blacklist;
1275 do {
1276 g_debug("disabling command: %s", (char *)l->data);
1277 qmp_disable_command(&ga_commands, l->data);
1278 l = g_list_next(l);
1279 } while (l);
1280 }
1281 s->command_state = ga_command_state_new();
1282 ga_command_state_init(s, s->command_state);
1283 ga_command_state_init_all(s->command_state);
1284 json_message_parser_init(&s->parser, process_event, s, NULL);
1285
1286 #ifndef _WIN32
1287 if (!register_signal_handlers()) {
1288 g_critical("failed to register signal handlers");
1289 return EXIT_FAILURE;
1290 }
1291 #endif
1292
1293 s->main_loop = g_main_loop_new(NULL, false);
1294
1295 if (!channel_init(ga_state, config->method, config->channel_path,
1296 socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
1297 g_critical("failed to initialize guest agent channel");
1298 return EXIT_FAILURE;
1299 }
1300 #ifndef _WIN32
1301 g_main_loop_run(ga_state->main_loop);
1302 #else
1303 if (config->daemonize) {
1304 SERVICE_TABLE_ENTRY service_table[] = {
1305 { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1306 StartServiceCtrlDispatcher(service_table);
1307 } else {
1308 g_main_loop_run(ga_state->main_loop);
1309 }
1310 #endif
1311
1312 return EXIT_SUCCESS;
1313 }
1314
1315 int main(int argc, char **argv)
1316 {
1317 int ret = EXIT_SUCCESS;
1318 GAState *s = g_new0(GAState, 1);
1319 GAConfig *config = g_new0(GAConfig, 1);
1320 int socket_activation;
1321
1322 config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1323
1324 qga_qmp_init_marshal(&ga_commands);
1325
1326 init_dfl_pathnames();
1327 config_load(config);
1328 config_parse(config, argc, argv);
1329
1330 if (config->pid_filepath == NULL) {
1331 config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1332 }
1333
1334 if (config->state_dir == NULL) {
1335 config->state_dir = g_strdup(dfl_pathnames.state_dir);
1336 }
1337
1338 if (config->method == NULL) {
1339 config->method = g_strdup("virtio-serial");
1340 }
1341
1342 socket_activation = check_socket_activation();
1343 if (socket_activation > 1) {
1344 g_critical("qemu-ga only supports listening on one socket");
1345 ret = EXIT_FAILURE;
1346 goto end;
1347 }
1348 if (socket_activation) {
1349 SocketAddress *addr;
1350
1351 g_free(config->method);
1352 g_free(config->channel_path);
1353 config->method = NULL;
1354 config->channel_path = NULL;
1355
1356 addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL);
1357 if (addr) {
1358 if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
1359 config->method = g_strdup("unix-listen");
1360 } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
1361 config->method = g_strdup("vsock-listen");
1362 }
1363
1364 qapi_free_SocketAddress(addr);
1365 }
1366
1367 if (!config->method) {
1368 g_critical("unsupported listen fd type");
1369 ret = EXIT_FAILURE;
1370 goto end;
1371 }
1372 } else if (config->channel_path == NULL) {
1373 if (strcmp(config->method, "virtio-serial") == 0) {
1374 /* try the default path for the virtio-serial port */
1375 config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1376 } else if (strcmp(config->method, "isa-serial") == 0) {
1377 /* try the default path for the serial port - COM1 */
1378 config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1379 } else {
1380 g_critical("must specify a path for this channel");
1381 ret = EXIT_FAILURE;
1382 goto end;
1383 }
1384 }
1385
1386 s->log_level = config->log_level;
1387 s->log_file = stderr;
1388 #ifdef CONFIG_FSFREEZE
1389 s->fsfreeze_hook = config->fsfreeze_hook;
1390 #endif
1391 s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1392 s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1393 config->state_dir);
1394 s->frozen = check_is_frozen(s);
1395
1396 if (config->dumpconf) {
1397 config_dump(config);
1398 goto end;
1399 }
1400
1401 ret = run_agent(s, config, socket_activation);
1402
1403 end:
1404 if (s->command_state) {
1405 ga_command_state_cleanup_all(s->command_state);
1406 ga_command_state_free(s->command_state);
1407 json_message_parser_destroy(&s->parser);
1408 }
1409 if (s->channel) {
1410 ga_channel_free(s->channel);
1411 }
1412 g_free(s->pstate_filepath);
1413 g_free(s->state_filepath_isfrozen);
1414
1415 if (config->daemonize) {
1416 unlink(config->pid_filepath);
1417 }
1418
1419 config_free(config);
1420 if (s->main_loop) {
1421 g_main_loop_unref(s->main_loop);
1422 }
1423 g_free(s);
1424
1425 return ret;
1426 }