Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2017-02-28' into staging
[qemu/ar7.git] / qga / main.c
blob9435bc74b84120881163c54b8bbd4fa87607f5e1
1 /*
2 * QEMU Guest Agent
4 * Copyright IBM Corp. 2011
6 * Authors:
7 * Adam Litke <aglitke@linux.vnet.ibm.com>
8 * Michael Roth <mdroth@linux.vnet.ibm.com>
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.
13 #include "qemu/osdep.h"
14 #include <getopt.h>
15 #include <glib/gstdio.h>
16 #ifndef _WIN32
17 #include <syslog.h>
18 #include <sys/wait.h>
19 #endif
20 #include "qapi/qmp/json-streamer.h"
21 #include "qapi/qmp/json-parser.h"
22 #include "qapi/qmp/qint.h"
23 #include "qapi/qmp/qjson.h"
24 #include "qga/guest-agent-core.h"
25 #include "qemu/module.h"
26 #include "qapi/qmp/qerror.h"
27 #include "qapi/qmp/dispatch.h"
28 #include "qga/channel.h"
29 #include "qemu/bswap.h"
30 #include "qemu/help_option.h"
31 #ifdef _WIN32
32 #include "qga/service-win32.h"
33 #include "qga/vss-win32.h"
34 #endif
35 #ifdef __linux__
36 #include <linux/fs.h>
37 #ifdef FIFREEZE
38 #define CONFIG_FSFREEZE
39 #endif
40 #endif
42 #ifndef _WIN32
43 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
44 #define QGA_STATE_RELATIVE_DIR "run"
45 #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
46 #else
47 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
48 #define QGA_STATE_RELATIVE_DIR "qemu-ga"
49 #define QGA_SERIAL_PATH_DEFAULT "COM1"
50 #endif
51 #ifdef CONFIG_FSFREEZE
52 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
53 #endif
54 #define QGA_SENTINEL_BYTE 0xFF
55 #define QGA_CONF_DEFAULT CONFIG_QEMU_CONFDIR G_DIR_SEPARATOR_S "qemu-ga.conf"
57 static struct {
58 const char *state_dir;
59 const char *pidfile;
60 } dfl_pathnames;
62 typedef struct GAPersistentState {
63 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
64 int64_t fd_counter;
65 } GAPersistentState;
67 struct GAState {
68 JSONMessageParser parser;
69 GMainLoop *main_loop;
70 GAChannel *channel;
71 bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
72 GACommandState *command_state;
73 GLogLevelFlags log_level;
74 FILE *log_file;
75 bool logging_enabled;
76 #ifdef _WIN32
77 GAService service;
78 #endif
79 bool delimit_response;
80 bool frozen;
81 GList *blacklist;
82 char *state_filepath_isfrozen;
83 struct {
84 const char *log_filepath;
85 const char *pid_filepath;
86 } deferred_options;
87 #ifdef CONFIG_FSFREEZE
88 const char *fsfreeze_hook;
89 #endif
90 gchar *pstate_filepath;
91 GAPersistentState pstate;
94 struct GAState *ga_state;
95 QmpCommandList ga_commands;
97 /* commands that are safe to issue while filesystems are frozen */
98 static const char *ga_freeze_whitelist[] = {
99 "guest-ping",
100 "guest-info",
101 "guest-sync",
102 "guest-sync-delimited",
103 "guest-fsfreeze-status",
104 "guest-fsfreeze-thaw",
105 NULL
108 #ifdef _WIN32
109 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
110 LPVOID ctx);
111 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
112 #endif
114 static void
115 init_dfl_pathnames(void)
117 g_assert(dfl_pathnames.state_dir == NULL);
118 g_assert(dfl_pathnames.pidfile == NULL);
119 dfl_pathnames.state_dir = qemu_get_local_state_pathname(
120 QGA_STATE_RELATIVE_DIR);
121 dfl_pathnames.pidfile = qemu_get_local_state_pathname(
122 QGA_STATE_RELATIVE_DIR G_DIR_SEPARATOR_S "qemu-ga.pid");
125 static void quit_handler(int sig)
127 /* if we're frozen, don't exit unless we're absolutely forced to,
128 * because it's basically impossible for graceful exit to complete
129 * unless all log/pid files are on unfreezable filesystems. there's
130 * also a very likely chance killing the agent before unfreezing
131 * the filesystems is a mistake (or will be viewed as one later).
133 if (ga_is_frozen(ga_state)) {
134 return;
136 g_debug("received signal num %d, quitting", sig);
138 if (g_main_loop_is_running(ga_state->main_loop)) {
139 g_main_loop_quit(ga_state->main_loop);
143 #ifndef _WIN32
144 static gboolean register_signal_handlers(void)
146 struct sigaction sigact;
147 int ret;
149 memset(&sigact, 0, sizeof(struct sigaction));
150 sigact.sa_handler = quit_handler;
152 ret = sigaction(SIGINT, &sigact, NULL);
153 if (ret == -1) {
154 g_error("error configuring signal handler: %s", strerror(errno));
156 ret = sigaction(SIGTERM, &sigact, NULL);
157 if (ret == -1) {
158 g_error("error configuring signal handler: %s", strerror(errno));
161 sigact.sa_handler = SIG_IGN;
162 if (sigaction(SIGPIPE, &sigact, NULL) != 0) {
163 g_error("error configuring SIGPIPE signal handler: %s",
164 strerror(errno));
167 return true;
170 /* TODO: use this in place of all post-fork() fclose(std*) callers */
171 void reopen_fd_to_null(int fd)
173 int nullfd;
175 nullfd = open("/dev/null", O_RDWR);
176 if (nullfd < 0) {
177 return;
180 dup2(nullfd, fd);
182 if (nullfd != fd) {
183 close(nullfd);
186 #endif
188 static void usage(const char *cmd)
190 printf(
191 "Usage: %s [-m <method> -p <path>] [<options>]\n"
192 "QEMU Guest Agent %s\n"
193 "\n"
194 " -m, --method transport method: one of unix-listen, virtio-serial,\n"
195 " isa-serial, or vsock-listen (virtio-serial is the default)\n"
196 " -p, --path device/socket path (the default for virtio-serial is:\n"
197 " %s,\n"
198 " the default for isa-serial is:\n"
199 " %s)\n"
200 " -l, --logfile set logfile path, logs to stderr by default\n"
201 " -f, --pidfile specify pidfile (default is %s)\n"
202 #ifdef CONFIG_FSFREEZE
203 " -F, --fsfreeze-hook\n"
204 " enable fsfreeze hook. Accepts an optional argument that\n"
205 " specifies script to run on freeze/thaw. Script will be\n"
206 " called with 'freeze'/'thaw' arguments accordingly.\n"
207 " (default is %s)\n"
208 " If using -F with an argument, do not follow -F with a\n"
209 " space.\n"
210 " (for example: -F/var/run/fsfreezehook.sh)\n"
211 #endif
212 " -t, --statedir specify dir to store state information (absolute paths\n"
213 " only, default is %s)\n"
214 " -v, --verbose log extra debugging information\n"
215 " -V, --version print version information and exit\n"
216 " -d, --daemonize become a daemon\n"
217 #ifdef _WIN32
218 " -s, --service service commands: install, uninstall, vss-install, vss-uninstall\n"
219 #endif
220 " -b, --blacklist comma-separated list of RPCs to disable (no spaces, \"?\"\n"
221 " to list available RPCs)\n"
222 " -D, --dump-conf dump a qemu-ga config file based on current config\n"
223 " options / command-line parameters to stdout\n"
224 " -h, --help display this help and exit\n"
225 "\n"
226 "Report bugs to <mdroth@linux.vnet.ibm.com>\n"
227 , cmd, QEMU_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT,
228 dfl_pathnames.pidfile,
229 #ifdef CONFIG_FSFREEZE
230 QGA_FSFREEZE_HOOK_DEFAULT,
231 #endif
232 dfl_pathnames.state_dir);
235 static const char *ga_log_level_str(GLogLevelFlags level)
237 switch (level & G_LOG_LEVEL_MASK) {
238 case G_LOG_LEVEL_ERROR:
239 return "error";
240 case G_LOG_LEVEL_CRITICAL:
241 return "critical";
242 case G_LOG_LEVEL_WARNING:
243 return "warning";
244 case G_LOG_LEVEL_MESSAGE:
245 return "message";
246 case G_LOG_LEVEL_INFO:
247 return "info";
248 case G_LOG_LEVEL_DEBUG:
249 return "debug";
250 default:
251 return "user";
255 bool ga_logging_enabled(GAState *s)
257 return s->logging_enabled;
260 void ga_disable_logging(GAState *s)
262 s->logging_enabled = false;
265 void ga_enable_logging(GAState *s)
267 s->logging_enabled = true;
270 static void ga_log(const gchar *domain, GLogLevelFlags level,
271 const gchar *msg, gpointer opaque)
273 GAState *s = opaque;
274 GTimeVal time;
275 const char *level_str = ga_log_level_str(level);
277 if (!ga_logging_enabled(s)) {
278 return;
281 level &= G_LOG_LEVEL_MASK;
282 #ifndef _WIN32
283 if (g_strcmp0(domain, "syslog") == 0) {
284 syslog(LOG_INFO, "%s: %s", level_str, msg);
285 } else if (level & s->log_level) {
286 #else
287 if (level & s->log_level) {
288 #endif
289 g_get_current_time(&time);
290 fprintf(s->log_file,
291 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
292 fflush(s->log_file);
296 void ga_set_response_delimited(GAState *s)
298 s->delimit_response = true;
301 static FILE *ga_open_logfile(const char *logfile)
303 FILE *f;
305 f = fopen(logfile, "a");
306 if (!f) {
307 return NULL;
310 qemu_set_cloexec(fileno(f));
311 return f;
314 #ifndef _WIN32
315 static bool ga_open_pidfile(const char *pidfile)
317 int pidfd;
318 char pidstr[32];
320 pidfd = qemu_open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
321 if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) {
322 g_critical("Cannot lock pid file, %s", strerror(errno));
323 if (pidfd != -1) {
324 close(pidfd);
326 return false;
329 if (ftruncate(pidfd, 0)) {
330 g_critical("Failed to truncate pid file");
331 goto fail;
333 snprintf(pidstr, sizeof(pidstr), "%d\n", getpid());
334 if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
335 g_critical("Failed to write pid file");
336 goto fail;
339 /* keep pidfile open & locked forever */
340 return true;
342 fail:
343 unlink(pidfile);
344 close(pidfd);
345 return false;
347 #else /* _WIN32 */
348 static bool ga_open_pidfile(const char *pidfile)
350 return true;
352 #endif
354 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
356 return strcmp(str1, str2);
359 /* disable commands that aren't safe for fsfreeze */
360 static void ga_disable_non_whitelisted(QmpCommand *cmd, void *opaque)
362 bool whitelisted = false;
363 int i = 0;
364 const char *name = qmp_command_name(cmd);
366 while (ga_freeze_whitelist[i] != NULL) {
367 if (strcmp(name, ga_freeze_whitelist[i]) == 0) {
368 whitelisted = true;
370 i++;
372 if (!whitelisted) {
373 g_debug("disabling command: %s", name);
374 qmp_disable_command(&ga_commands, name);
378 /* [re-]enable all commands, except those explicitly blacklisted by user */
379 static void ga_enable_non_blacklisted(QmpCommand *cmd, void *opaque)
381 GList *blacklist = opaque;
382 const char *name = qmp_command_name(cmd);
384 if (g_list_find_custom(blacklist, name, ga_strcmp) == NULL &&
385 !qmp_command_is_enabled(cmd)) {
386 g_debug("enabling command: %s", name);
387 qmp_enable_command(&ga_commands, name);
391 static bool ga_create_file(const char *path)
393 int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
394 if (fd == -1) {
395 g_warning("unable to open/create file %s: %s", path, strerror(errno));
396 return false;
398 close(fd);
399 return true;
402 static bool ga_delete_file(const char *path)
404 int ret = unlink(path);
405 if (ret == -1) {
406 g_warning("unable to delete file: %s: %s", path, strerror(errno));
407 return false;
410 return true;
413 bool ga_is_frozen(GAState *s)
415 return s->frozen;
418 void ga_set_frozen(GAState *s)
420 if (ga_is_frozen(s)) {
421 return;
423 /* disable all non-whitelisted (for frozen state) commands */
424 qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
425 g_warning("disabling logging due to filesystem freeze");
426 ga_disable_logging(s);
427 s->frozen = true;
428 if (!ga_create_file(s->state_filepath_isfrozen)) {
429 g_warning("unable to create %s, fsfreeze may not function properly",
430 s->state_filepath_isfrozen);
434 void ga_unset_frozen(GAState *s)
436 if (!ga_is_frozen(s)) {
437 return;
440 /* if we delayed creation/opening of pid/log files due to being
441 * in a frozen state at start up, do it now
443 if (s->deferred_options.log_filepath) {
444 s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
445 if (!s->log_file) {
446 s->log_file = stderr;
448 s->deferred_options.log_filepath = NULL;
450 ga_enable_logging(s);
451 g_warning("logging re-enabled due to filesystem unfreeze");
452 if (s->deferred_options.pid_filepath) {
453 if (!ga_open_pidfile(s->deferred_options.pid_filepath)) {
454 g_warning("failed to create/open pid file");
456 s->deferred_options.pid_filepath = NULL;
459 /* enable all disabled, non-blacklisted commands */
460 qmp_for_each_command(&ga_commands, ga_enable_non_blacklisted, s->blacklist);
461 s->frozen = false;
462 if (!ga_delete_file(s->state_filepath_isfrozen)) {
463 g_warning("unable to delete %s, fsfreeze may not function properly",
464 s->state_filepath_isfrozen);
468 #ifdef CONFIG_FSFREEZE
469 const char *ga_fsfreeze_hook(GAState *s)
471 return s->fsfreeze_hook;
473 #endif
475 static void become_daemon(const char *pidfile)
477 #ifndef _WIN32
478 pid_t pid, sid;
480 pid = fork();
481 if (pid < 0) {
482 exit(EXIT_FAILURE);
484 if (pid > 0) {
485 exit(EXIT_SUCCESS);
488 if (pidfile) {
489 if (!ga_open_pidfile(pidfile)) {
490 g_critical("failed to create pidfile");
491 exit(EXIT_FAILURE);
495 umask(S_IRWXG | S_IRWXO);
496 sid = setsid();
497 if (sid < 0) {
498 goto fail;
500 if ((chdir("/")) < 0) {
501 goto fail;
504 reopen_fd_to_null(STDIN_FILENO);
505 reopen_fd_to_null(STDOUT_FILENO);
506 reopen_fd_to_null(STDERR_FILENO);
507 return;
509 fail:
510 if (pidfile) {
511 unlink(pidfile);
513 g_critical("failed to daemonize");
514 exit(EXIT_FAILURE);
515 #endif
518 static int send_response(GAState *s, QObject *payload)
520 const char *buf;
521 QString *payload_qstr, *response_qstr;
522 GIOStatus status;
524 g_assert(payload && s->channel);
526 payload_qstr = qobject_to_json(payload);
527 if (!payload_qstr) {
528 return -EINVAL;
531 if (s->delimit_response) {
532 s->delimit_response = false;
533 response_qstr = qstring_new();
534 qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
535 qstring_append(response_qstr, qstring_get_str(payload_qstr));
536 QDECREF(payload_qstr);
537 } else {
538 response_qstr = payload_qstr;
541 qstring_append_chr(response_qstr, '\n');
542 buf = qstring_get_str(response_qstr);
543 status = ga_channel_write_all(s->channel, buf, strlen(buf));
544 QDECREF(response_qstr);
545 if (status != G_IO_STATUS_NORMAL) {
546 return -EIO;
549 return 0;
552 static void process_command(GAState *s, QDict *req)
554 QObject *rsp = NULL;
555 int ret;
557 g_assert(req);
558 g_debug("processing command");
559 rsp = qmp_dispatch(&ga_commands, QOBJECT(req));
560 if (rsp) {
561 ret = send_response(s, rsp);
562 if (ret < 0) {
563 g_warning("error sending response: %s", strerror(-ret));
565 qobject_decref(rsp);
569 /* handle requests/control events coming in over the channel */
570 static void process_event(JSONMessageParser *parser, GQueue *tokens)
572 GAState *s = container_of(parser, GAState, parser);
573 QDict *qdict;
574 Error *err = NULL;
575 int ret;
577 g_assert(s && parser);
579 g_debug("process_event: called");
580 qdict = qobject_to_qdict(json_parser_parse_err(tokens, NULL, &err));
581 if (err || !qdict) {
582 QDECREF(qdict);
583 qdict = qdict_new();
584 if (!err) {
585 g_warning("failed to parse event: unknown error");
586 error_setg(&err, QERR_JSON_PARSING);
587 } else {
588 g_warning("failed to parse event: %s", error_get_pretty(err));
590 qdict_put_obj(qdict, "error", qmp_build_error_object(err));
591 error_free(err);
594 /* handle host->guest commands */
595 if (qdict_haskey(qdict, "execute")) {
596 process_command(s, qdict);
597 } else {
598 if (!qdict_haskey(qdict, "error")) {
599 QDECREF(qdict);
600 qdict = qdict_new();
601 g_warning("unrecognized payload format");
602 error_setg(&err, QERR_UNSUPPORTED);
603 qdict_put_obj(qdict, "error", qmp_build_error_object(err));
604 error_free(err);
606 ret = send_response(s, QOBJECT(qdict));
607 if (ret < 0) {
608 g_warning("error sending error response: %s", strerror(-ret));
612 QDECREF(qdict);
615 /* false return signals GAChannel to close the current client connection */
616 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
618 GAState *s = data;
619 gchar buf[QGA_READ_COUNT_DEFAULT+1];
620 gsize count;
621 GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
622 switch (status) {
623 case G_IO_STATUS_ERROR:
624 g_warning("error reading channel");
625 return false;
626 case G_IO_STATUS_NORMAL:
627 buf[count] = 0;
628 g_debug("read data, count: %d, data: %s", (int)count, buf);
629 json_message_parser_feed(&s->parser, (char *)buf, (int)count);
630 break;
631 case G_IO_STATUS_EOF:
632 g_debug("received EOF");
633 if (!s->virtio) {
634 return false;
636 /* fall through */
637 case G_IO_STATUS_AGAIN:
638 /* virtio causes us to spin here when no process is attached to
639 * host-side chardev. sleep a bit to mitigate this
641 if (s->virtio) {
642 usleep(100*1000);
644 return true;
645 default:
646 g_warning("unknown channel read status, closing");
647 return false;
649 return true;
652 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
654 GAChannelMethod channel_method;
656 if (strcmp(method, "virtio-serial") == 0) {
657 s->virtio = true; /* virtio requires special handling in some cases */
658 channel_method = GA_CHANNEL_VIRTIO_SERIAL;
659 } else if (strcmp(method, "isa-serial") == 0) {
660 channel_method = GA_CHANNEL_ISA_SERIAL;
661 } else if (strcmp(method, "unix-listen") == 0) {
662 channel_method = GA_CHANNEL_UNIX_LISTEN;
663 } else if (strcmp(method, "vsock-listen") == 0) {
664 channel_method = GA_CHANNEL_VSOCK_LISTEN;
665 } else {
666 g_critical("unsupported channel method/type: %s", method);
667 return false;
670 s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
671 if (!s->channel) {
672 g_critical("failed to create guest agent channel");
673 return false;
676 return true;
679 #ifdef _WIN32
680 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
681 LPVOID ctx)
683 DWORD ret = NO_ERROR;
684 GAService *service = &ga_state->service;
686 switch (ctrl)
688 case SERVICE_CONTROL_STOP:
689 case SERVICE_CONTROL_SHUTDOWN:
690 quit_handler(SIGTERM);
691 service->status.dwCurrentState = SERVICE_STOP_PENDING;
692 SetServiceStatus(service->status_handle, &service->status);
693 break;
695 default:
696 ret = ERROR_CALL_NOT_IMPLEMENTED;
698 return ret;
701 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
703 GAService *service = &ga_state->service;
705 service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
706 service_ctrl_handler, NULL);
708 if (service->status_handle == 0) {
709 g_critical("Failed to register extended requests function!\n");
710 return;
713 service->status.dwServiceType = SERVICE_WIN32;
714 service->status.dwCurrentState = SERVICE_RUNNING;
715 service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
716 service->status.dwWin32ExitCode = NO_ERROR;
717 service->status.dwServiceSpecificExitCode = NO_ERROR;
718 service->status.dwCheckPoint = 0;
719 service->status.dwWaitHint = 0;
720 SetServiceStatus(service->status_handle, &service->status);
722 g_main_loop_run(ga_state->main_loop);
724 service->status.dwCurrentState = SERVICE_STOPPED;
725 SetServiceStatus(service->status_handle, &service->status);
727 #endif
729 static void set_persistent_state_defaults(GAPersistentState *pstate)
731 g_assert(pstate);
732 pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
735 static void persistent_state_from_keyfile(GAPersistentState *pstate,
736 GKeyFile *keyfile)
738 g_assert(pstate);
739 g_assert(keyfile);
740 /* if any fields are missing, either because the file was tampered with
741 * by agents of chaos, or because the field wasn't present at the time the
742 * file was created, the best we can ever do is start over with the default
743 * values. so load them now, and ignore any errors in accessing key-value
744 * pairs
746 set_persistent_state_defaults(pstate);
748 if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
749 pstate->fd_counter =
750 g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
754 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
755 GKeyFile *keyfile)
757 g_assert(pstate);
758 g_assert(keyfile);
760 g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
763 static gboolean write_persistent_state(const GAPersistentState *pstate,
764 const gchar *path)
766 GKeyFile *keyfile = g_key_file_new();
767 GError *gerr = NULL;
768 gboolean ret = true;
769 gchar *data = NULL;
770 gsize data_len;
772 g_assert(pstate);
774 persistent_state_to_keyfile(pstate, keyfile);
775 data = g_key_file_to_data(keyfile, &data_len, &gerr);
776 if (gerr) {
777 g_critical("failed to convert persistent state to string: %s",
778 gerr->message);
779 ret = false;
780 goto out;
783 g_file_set_contents(path, data, data_len, &gerr);
784 if (gerr) {
785 g_critical("failed to write persistent state to %s: %s",
786 path, gerr->message);
787 ret = false;
788 goto out;
791 out:
792 if (gerr) {
793 g_error_free(gerr);
795 if (keyfile) {
796 g_key_file_free(keyfile);
798 g_free(data);
799 return ret;
802 static gboolean read_persistent_state(GAPersistentState *pstate,
803 const gchar *path, gboolean frozen)
805 GKeyFile *keyfile = NULL;
806 GError *gerr = NULL;
807 struct stat st;
808 gboolean ret = true;
810 g_assert(pstate);
812 if (stat(path, &st) == -1) {
813 /* it's okay if state file doesn't exist, but any other error
814 * indicates a permissions issue or some other misconfiguration
815 * that we likely won't be able to recover from.
817 if (errno != ENOENT) {
818 g_critical("unable to access state file at path %s: %s",
819 path, strerror(errno));
820 ret = false;
821 goto out;
824 /* file doesn't exist. initialize state to default values and
825 * attempt to save now. (we could wait till later when we have
826 * modified state we need to commit, but if there's a problem,
827 * such as a missing parent directory, we want to catch it now)
829 * there is a potential scenario where someone either managed to
830 * update the agent from a version that didn't use a key store
831 * while qemu-ga thought the filesystem was frozen, or
832 * deleted the key store prior to issuing a fsfreeze, prior
833 * to restarting the agent. in this case we go ahead and defer
834 * initial creation till we actually have modified state to
835 * write, otherwise fail to recover from freeze.
837 set_persistent_state_defaults(pstate);
838 if (!frozen) {
839 ret = write_persistent_state(pstate, path);
840 if (!ret) {
841 g_critical("unable to create state file at path %s", path);
842 ret = false;
843 goto out;
846 ret = true;
847 goto out;
850 keyfile = g_key_file_new();
851 g_key_file_load_from_file(keyfile, path, 0, &gerr);
852 if (gerr) {
853 g_critical("error loading persistent state from path: %s, %s",
854 path, gerr->message);
855 ret = false;
856 goto out;
859 persistent_state_from_keyfile(pstate, keyfile);
861 out:
862 if (keyfile) {
863 g_key_file_free(keyfile);
865 if (gerr) {
866 g_error_free(gerr);
869 return ret;
872 int64_t ga_get_fd_handle(GAState *s, Error **errp)
874 int64_t handle;
876 g_assert(s->pstate_filepath);
877 /* we blacklist commands and avoid operations that potentially require
878 * writing to disk when we're in a frozen state. this includes opening
879 * new files, so we should never get here in that situation
881 g_assert(!ga_is_frozen(s));
883 handle = s->pstate.fd_counter++;
885 /* This should never happen on a reasonable timeframe, as guest-file-open
886 * would have to be issued 2^63 times */
887 if (s->pstate.fd_counter == INT64_MAX) {
888 abort();
891 if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
892 error_setg(errp, "failed to commit persistent state to disk");
893 return -1;
896 return handle;
899 static void ga_print_cmd(QmpCommand *cmd, void *opaque)
901 printf("%s\n", qmp_command_name(cmd));
904 static GList *split_list(const gchar *str, const gchar *delim)
906 GList *list = NULL;
907 int i;
908 gchar **strv;
910 strv = g_strsplit(str, delim, -1);
911 for (i = 0; strv[i]; i++) {
912 list = g_list_prepend(list, strv[i]);
914 g_free(strv);
916 return list;
919 typedef struct GAConfig {
920 char *channel_path;
921 char *method;
922 char *log_filepath;
923 char *pid_filepath;
924 #ifdef CONFIG_FSFREEZE
925 char *fsfreeze_hook;
926 #endif
927 char *state_dir;
928 #ifdef _WIN32
929 const char *service;
930 #endif
931 gchar *bliststr; /* blacklist may point to this string */
932 GList *blacklist;
933 int daemonize;
934 GLogLevelFlags log_level;
935 int dumpconf;
936 } GAConfig;
938 static void config_load(GAConfig *config)
940 GError *gerr = NULL;
941 GKeyFile *keyfile;
942 const char *conf = g_getenv("QGA_CONF") ?: QGA_CONF_DEFAULT;
944 /* read system config */
945 keyfile = g_key_file_new();
946 if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
947 goto end;
949 if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
950 config->daemonize =
951 g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
953 if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
954 config->method =
955 g_key_file_get_string(keyfile, "general", "method", &gerr);
957 if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
958 config->channel_path =
959 g_key_file_get_string(keyfile, "general", "path", &gerr);
961 if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
962 config->log_filepath =
963 g_key_file_get_string(keyfile, "general", "logfile", &gerr);
965 if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
966 config->pid_filepath =
967 g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
969 #ifdef CONFIG_FSFREEZE
970 if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
971 config->fsfreeze_hook =
972 g_key_file_get_string(keyfile,
973 "general", "fsfreeze-hook", &gerr);
975 #endif
976 if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
977 config->state_dir =
978 g_key_file_get_string(keyfile, "general", "statedir", &gerr);
980 if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
981 g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
982 /* enable all log levels */
983 config->log_level = G_LOG_LEVEL_MASK;
985 if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
986 config->bliststr =
987 g_key_file_get_string(keyfile, "general", "blacklist", &gerr);
988 config->blacklist = g_list_concat(config->blacklist,
989 split_list(config->bliststr, ","));
992 end:
993 g_key_file_free(keyfile);
994 if (gerr &&
995 !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
996 g_critical("error loading configuration from path: %s, %s",
997 QGA_CONF_DEFAULT, gerr->message);
998 exit(EXIT_FAILURE);
1000 g_clear_error(&gerr);
1003 static gchar *list_join(GList *list, const gchar separator)
1005 GString *str = g_string_new("");
1007 while (list) {
1008 str = g_string_append(str, (gchar *)list->data);
1009 list = g_list_next(list);
1010 if (list) {
1011 str = g_string_append_c(str, separator);
1015 return g_string_free(str, FALSE);
1018 static void config_dump(GAConfig *config)
1020 GError *error = NULL;
1021 GKeyFile *keyfile;
1022 gchar *tmp;
1024 keyfile = g_key_file_new();
1025 g_assert(keyfile);
1027 g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1028 g_key_file_set_string(keyfile, "general", "method", config->method);
1029 g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1030 if (config->log_filepath) {
1031 g_key_file_set_string(keyfile, "general", "logfile",
1032 config->log_filepath);
1034 g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1035 #ifdef CONFIG_FSFREEZE
1036 if (config->fsfreeze_hook) {
1037 g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1038 config->fsfreeze_hook);
1040 #endif
1041 g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1042 g_key_file_set_boolean(keyfile, "general", "verbose",
1043 config->log_level == G_LOG_LEVEL_MASK);
1044 tmp = list_join(config->blacklist, ',');
1045 g_key_file_set_string(keyfile, "general", "blacklist", tmp);
1046 g_free(tmp);
1048 tmp = g_key_file_to_data(keyfile, NULL, &error);
1049 printf("%s", tmp);
1051 g_free(tmp);
1052 g_key_file_free(keyfile);
1055 static void config_parse(GAConfig *config, int argc, char **argv)
1057 const char *sopt = "hVvdm:p:l:f:F::b:s:t:D";
1058 int opt_ind = 0, ch;
1059 const struct option lopt[] = {
1060 { "help", 0, NULL, 'h' },
1061 { "version", 0, NULL, 'V' },
1062 { "dump-conf", 0, NULL, 'D' },
1063 { "logfile", 1, NULL, 'l' },
1064 { "pidfile", 1, NULL, 'f' },
1065 #ifdef CONFIG_FSFREEZE
1066 { "fsfreeze-hook", 2, NULL, 'F' },
1067 #endif
1068 { "verbose", 0, NULL, 'v' },
1069 { "method", 1, NULL, 'm' },
1070 { "path", 1, NULL, 'p' },
1071 { "daemonize", 0, NULL, 'd' },
1072 { "blacklist", 1, NULL, 'b' },
1073 #ifdef _WIN32
1074 { "service", 1, NULL, 's' },
1075 #endif
1076 { "statedir", 1, NULL, 't' },
1077 { NULL, 0, NULL, 0 }
1080 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1081 switch (ch) {
1082 case 'm':
1083 g_free(config->method);
1084 config->method = g_strdup(optarg);
1085 break;
1086 case 'p':
1087 g_free(config->channel_path);
1088 config->channel_path = g_strdup(optarg);
1089 break;
1090 case 'l':
1091 g_free(config->log_filepath);
1092 config->log_filepath = g_strdup(optarg);
1093 break;
1094 case 'f':
1095 g_free(config->pid_filepath);
1096 config->pid_filepath = g_strdup(optarg);
1097 break;
1098 #ifdef CONFIG_FSFREEZE
1099 case 'F':
1100 g_free(config->fsfreeze_hook);
1101 config->fsfreeze_hook = g_strdup(optarg ?: QGA_FSFREEZE_HOOK_DEFAULT);
1102 break;
1103 #endif
1104 case 't':
1105 g_free(config->state_dir);
1106 config->state_dir = g_strdup(optarg);
1107 break;
1108 case 'v':
1109 /* enable all log levels */
1110 config->log_level = G_LOG_LEVEL_MASK;
1111 break;
1112 case 'V':
1113 printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1114 exit(EXIT_SUCCESS);
1115 case 'd':
1116 config->daemonize = 1;
1117 break;
1118 case 'D':
1119 config->dumpconf = 1;
1120 break;
1121 case 'b': {
1122 if (is_help_option(optarg)) {
1123 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1124 exit(EXIT_SUCCESS);
1126 config->blacklist = g_list_concat(config->blacklist,
1127 split_list(optarg, ","));
1128 break;
1130 #ifdef _WIN32
1131 case 's':
1132 config->service = optarg;
1133 if (strcmp(config->service, "install") == 0) {
1134 if (ga_install_vss_provider()) {
1135 exit(EXIT_FAILURE);
1137 if (ga_install_service(config->channel_path,
1138 config->log_filepath, config->state_dir)) {
1139 exit(EXIT_FAILURE);
1141 exit(EXIT_SUCCESS);
1142 } else if (strcmp(config->service, "uninstall") == 0) {
1143 ga_uninstall_vss_provider();
1144 exit(ga_uninstall_service());
1145 } else if (strcmp(config->service, "vss-install") == 0) {
1146 if (ga_install_vss_provider()) {
1147 exit(EXIT_FAILURE);
1149 exit(EXIT_SUCCESS);
1150 } else if (strcmp(config->service, "vss-uninstall") == 0) {
1151 ga_uninstall_vss_provider();
1152 exit(EXIT_SUCCESS);
1153 } else {
1154 printf("Unknown service command.\n");
1155 exit(EXIT_FAILURE);
1157 break;
1158 #endif
1159 case 'h':
1160 usage(argv[0]);
1161 exit(EXIT_SUCCESS);
1162 case '?':
1163 g_print("Unknown option, try '%s --help' for more information.\n",
1164 argv[0]);
1165 exit(EXIT_FAILURE);
1170 static void config_free(GAConfig *config)
1172 g_free(config->method);
1173 g_free(config->log_filepath);
1174 g_free(config->pid_filepath);
1175 g_free(config->state_dir);
1176 g_free(config->channel_path);
1177 g_free(config->bliststr);
1178 #ifdef CONFIG_FSFREEZE
1179 g_free(config->fsfreeze_hook);
1180 #endif
1181 g_list_free_full(config->blacklist, g_free);
1182 g_free(config);
1185 static bool check_is_frozen(GAState *s)
1187 #ifndef _WIN32
1188 /* check if a previous instance of qemu-ga exited with filesystems' state
1189 * marked as frozen. this could be a stale value (a non-qemu-ga process
1190 * or reboot may have since unfrozen them), but better to require an
1191 * uneeded unfreeze than to risk hanging on start-up
1193 struct stat st;
1194 if (stat(s->state_filepath_isfrozen, &st) == -1) {
1195 /* it's okay if the file doesn't exist, but if we can't access for
1196 * some other reason, such as permissions, there's a configuration
1197 * that needs to be addressed. so just bail now before we get into
1198 * more trouble later
1200 if (errno != ENOENT) {
1201 g_critical("unable to access state file at path %s: %s",
1202 s->state_filepath_isfrozen, strerror(errno));
1203 return EXIT_FAILURE;
1205 } else {
1206 g_warning("previous instance appears to have exited with frozen"
1207 " filesystems. deferring logging/pidfile creation and"
1208 " disabling non-fsfreeze-safe commands until"
1209 " guest-fsfreeze-thaw is issued, or filesystems are"
1210 " manually unfrozen and the file %s is removed",
1211 s->state_filepath_isfrozen);
1212 return true;
1214 #endif
1215 return false;
1218 static int run_agent(GAState *s, GAConfig *config)
1220 ga_state = s;
1222 g_log_set_default_handler(ga_log, s);
1223 g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1224 ga_enable_logging(s);
1226 #ifdef _WIN32
1227 /* On win32 the state directory is application specific (be it the default
1228 * or a user override). We got past the command line parsing; let's create
1229 * the directory (with any intermediate directories). If we run into an
1230 * error later on, we won't try to clean up the directory, it is considered
1231 * persistent.
1233 if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1234 g_critical("unable to create (an ancestor of) the state directory"
1235 " '%s': %s", config->state_dir, strerror(errno));
1236 return EXIT_FAILURE;
1238 #endif
1240 if (ga_is_frozen(s)) {
1241 if (config->daemonize) {
1242 /* delay opening/locking of pidfile till filesystems are unfrozen */
1243 s->deferred_options.pid_filepath = config->pid_filepath;
1244 become_daemon(NULL);
1246 if (config->log_filepath) {
1247 /* delay opening the log file till filesystems are unfrozen */
1248 s->deferred_options.log_filepath = config->log_filepath;
1250 ga_disable_logging(s);
1251 qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
1252 } else {
1253 if (config->daemonize) {
1254 become_daemon(config->pid_filepath);
1256 if (config->log_filepath) {
1257 FILE *log_file = ga_open_logfile(config->log_filepath);
1258 if (!log_file) {
1259 g_critical("unable to open specified log file: %s",
1260 strerror(errno));
1261 return EXIT_FAILURE;
1263 s->log_file = log_file;
1267 /* load persistent state from disk */
1268 if (!read_persistent_state(&s->pstate,
1269 s->pstate_filepath,
1270 ga_is_frozen(s))) {
1271 g_critical("failed to load persistent state");
1272 return EXIT_FAILURE;
1275 config->blacklist = ga_command_blacklist_init(config->blacklist);
1276 if (config->blacklist) {
1277 GList *l = config->blacklist;
1278 s->blacklist = config->blacklist;
1279 do {
1280 g_debug("disabling command: %s", (char *)l->data);
1281 qmp_disable_command(&ga_commands, l->data);
1282 l = g_list_next(l);
1283 } while (l);
1285 s->command_state = ga_command_state_new();
1286 ga_command_state_init(s, s->command_state);
1287 ga_command_state_init_all(s->command_state);
1288 json_message_parser_init(&s->parser, process_event);
1289 ga_state = s;
1290 #ifndef _WIN32
1291 if (!register_signal_handlers()) {
1292 g_critical("failed to register signal handlers");
1293 return EXIT_FAILURE;
1295 #endif
1297 s->main_loop = g_main_loop_new(NULL, false);
1298 if (!channel_init(ga_state, config->method, config->channel_path)) {
1299 g_critical("failed to initialize guest agent channel");
1300 return EXIT_FAILURE;
1302 #ifndef _WIN32
1303 g_main_loop_run(ga_state->main_loop);
1304 #else
1305 if (config->daemonize) {
1306 SERVICE_TABLE_ENTRY service_table[] = {
1307 { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1308 StartServiceCtrlDispatcher(service_table);
1309 } else {
1310 g_main_loop_run(ga_state->main_loop);
1312 #endif
1314 return EXIT_SUCCESS;
1317 int main(int argc, char **argv)
1319 int ret = EXIT_SUCCESS;
1320 GAState *s = g_new0(GAState, 1);
1321 GAConfig *config = g_new0(GAConfig, 1);
1323 config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1325 qga_qmp_init_marshal(&ga_commands);
1327 init_dfl_pathnames();
1328 config_load(config);
1329 config_parse(config, argc, argv);
1331 if (config->pid_filepath == NULL) {
1332 config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1335 if (config->state_dir == NULL) {
1336 config->state_dir = g_strdup(dfl_pathnames.state_dir);
1339 if (config->method == NULL) {
1340 config->method = g_strdup("virtio-serial");
1343 if (config->channel_path == NULL) {
1344 if (strcmp(config->method, "virtio-serial") == 0) {
1345 /* try the default path for the virtio-serial port */
1346 config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1347 } else if (strcmp(config->method, "isa-serial") == 0) {
1348 /* try the default path for the serial port - COM1 */
1349 config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1350 } else {
1351 g_critical("must specify a path for this channel");
1352 ret = EXIT_FAILURE;
1353 goto end;
1357 s->log_level = config->log_level;
1358 s->log_file = stderr;
1359 #ifdef CONFIG_FSFREEZE
1360 s->fsfreeze_hook = config->fsfreeze_hook;
1361 #endif
1362 s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1363 s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1364 config->state_dir);
1365 s->frozen = check_is_frozen(s);
1367 if (config->dumpconf) {
1368 config_dump(config);
1369 goto end;
1372 ret = run_agent(s, config);
1374 end:
1375 if (s->command_state) {
1376 ga_command_state_cleanup_all(s->command_state);
1377 ga_command_state_free(s->command_state);
1378 json_message_parser_destroy(&s->parser);
1380 if (s->channel) {
1381 ga_channel_free(s->channel);
1383 g_free(s->pstate_filepath);
1384 g_free(s->state_filepath_isfrozen);
1386 if (config->daemonize) {
1387 unlink(config->pid_filepath);
1390 config_free(config);
1391 if (s->main_loop) {
1392 g_main_loop_unref(s->main_loop);
1394 g_free(s);
1396 return ret;