xref: /openbmc/qemu/qga/main.c (revision 756a98dd)
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 "qemu/help-texts.h"
22 #include "qapi/qmp/json-parser.h"
23 #include "qapi/qmp/qdict.h"
24 #include "qapi/qmp/qjson.h"
25 #include "guest-agent-core.h"
26 #include "qga-qapi-init-commands.h"
27 #include "qapi/qmp/qerror.h"
28 #include "qapi/error.h"
29 #include "channel.h"
30 #include "qemu/cutils.h"
31 #include "qemu/help_option.h"
32 #include "qemu/sockets.h"
33 #include "qemu/systemd.h"
34 #include "qemu-version.h"
35 #ifdef _WIN32
36 #include <dbt.h>
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 #define QGA_RETRY_INTERVAL 5
62 
63 static struct {
64     const char *state_dir;
65     const char *pidfile;
66 } dfl_pathnames;
67 
68 typedef struct GAPersistentState {
69 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
70     int64_t fd_counter;
71 } GAPersistentState;
72 
73 typedef struct GAConfig GAConfig;
74 
75 struct GAState {
76     JSONMessageParser parser;
77     GMainLoop *main_loop;
78     GAChannel *channel;
79     bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
80     GACommandState *command_state;
81     GLogLevelFlags log_level;
82     FILE *log_file;
83     bool logging_enabled;
84 #ifdef _WIN32
85     GAService service;
86     HANDLE wakeup_event;
87 #endif
88     bool delimit_response;
89     bool frozen;
90     GList *blacklist;
91     char *state_filepath_isfrozen;
92     struct {
93         const char *log_filepath;
94         const char *pid_filepath;
95     } deferred_options;
96 #ifdef CONFIG_FSFREEZE
97     const char *fsfreeze_hook;
98 #endif
99     gchar *pstate_filepath;
100     GAPersistentState pstate;
101     GAConfig *config;
102     int socket_activation;
103     bool force_exit;
104 };
105 
106 struct GAState *ga_state;
107 QmpCommandList ga_commands;
108 
109 /* commands that are safe to issue while filesystems are frozen */
110 static const char *ga_freeze_whitelist[] = {
111     "guest-ping",
112     "guest-info",
113     "guest-sync",
114     "guest-sync-delimited",
115     "guest-fsfreeze-status",
116     "guest-fsfreeze-thaw",
117     NULL
118 };
119 
120 #ifdef _WIN32
121 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
122                                   LPVOID ctx);
123 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data);
124 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
125 #endif
126 static int run_agent(GAState *s);
127 static void stop_agent(GAState *s, bool requested);
128 
129 static void
130 init_dfl_pathnames(void)
131 {
132     g_assert(dfl_pathnames.state_dir == NULL);
133     g_assert(dfl_pathnames.pidfile == NULL);
134     dfl_pathnames.state_dir = qemu_get_local_state_pathname(
135       QGA_STATE_RELATIVE_DIR);
136     dfl_pathnames.pidfile   = qemu_get_local_state_pathname(
137       QGA_STATE_RELATIVE_DIR G_DIR_SEPARATOR_S "qemu-ga.pid");
138 }
139 
140 static void quit_handler(int sig)
141 {
142     /* if we're frozen, don't exit unless we're absolutely forced to,
143      * because it's basically impossible for graceful exit to complete
144      * unless all log/pid files are on unfreezable filesystems. there's
145      * also a very likely chance killing the agent before unfreezing
146      * the filesystems is a mistake (or will be viewed as one later).
147      * On Windows the freeze interval is limited to 10 seconds, so
148      * we should quit, but first we should wait for the timeout, thaw
149      * the filesystem and quit.
150      */
151     if (ga_is_frozen(ga_state)) {
152 #ifdef _WIN32
153         int i = 0;
154         Error *err = NULL;
155         HANDLE hEventTimeout;
156 
157         g_debug("Thawing filesystems before exiting");
158 
159         hEventTimeout = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_TIMEOUT);
160         if (hEventTimeout) {
161             WaitForSingleObject(hEventTimeout, 0);
162             CloseHandle(hEventTimeout);
163         }
164         qga_vss_fsfreeze(&i, false, NULL, &err);
165         if (err) {
166             g_debug("Error unfreezing filesystems prior to exiting: %s",
167                 error_get_pretty(err));
168             error_free(err);
169         }
170 #else
171         return;
172 #endif
173     }
174     g_debug("received signal num %d, quitting", sig);
175 
176     stop_agent(ga_state, true);
177 }
178 
179 #ifndef _WIN32
180 static gboolean register_signal_handlers(void)
181 {
182     struct sigaction sigact;
183     int ret;
184 
185     memset(&sigact, 0, sizeof(struct sigaction));
186     sigact.sa_handler = quit_handler;
187 
188     ret = sigaction(SIGINT, &sigact, NULL);
189     if (ret == -1) {
190         g_error("error configuring signal handler: %s", strerror(errno));
191     }
192     ret = sigaction(SIGTERM, &sigact, NULL);
193     if (ret == -1) {
194         g_error("error configuring signal handler: %s", strerror(errno));
195     }
196 
197     sigact.sa_handler = SIG_IGN;
198     if (sigaction(SIGPIPE, &sigact, NULL) != 0) {
199         g_error("error configuring SIGPIPE signal handler: %s",
200                 strerror(errno));
201     }
202 
203     return true;
204 }
205 
206 /* TODO: use this in place of all post-fork() fclose(std*) callers */
207 void reopen_fd_to_null(int fd)
208 {
209     int nullfd;
210 
211     nullfd = open("/dev/null", O_RDWR);
212     if (nullfd < 0) {
213         return;
214     }
215 
216     dup2(nullfd, fd);
217 
218     if (nullfd != fd) {
219         close(nullfd);
220     }
221 }
222 #endif
223 
224 static void usage(const char *cmd)
225 {
226     printf(
227 "Usage: %s [-m <method> -p <path>] [<options>]\n"
228 "QEMU Guest Agent " QEMU_FULL_VERSION "\n"
229 QEMU_COPYRIGHT "\n"
230 "\n"
231 "  -m, --method      transport method: one of unix-listen, virtio-serial,\n"
232 "                    isa-serial, or vsock-listen (virtio-serial is the default)\n"
233 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
234 "                    %s,\n"
235 "                    the default for isa-serial is:\n"
236 "                    %s).\n"
237 "                    Socket addresses for vsock-listen are written as\n"
238 "                    <cid>:<port>.\n"
239 "  -l, --logfile     set logfile path, logs to stderr by default\n"
240 "  -f, --pidfile     specify pidfile (default is %s)\n"
241 #ifdef CONFIG_FSFREEZE
242 "  -F, --fsfreeze-hook\n"
243 "                    enable fsfreeze hook. Accepts an optional argument that\n"
244 "                    specifies script to run on freeze/thaw. Script will be\n"
245 "                    called with 'freeze'/'thaw' arguments accordingly.\n"
246 "                    (default is %s)\n"
247 "                    If using -F with an argument, do not follow -F with a\n"
248 "                    space.\n"
249 "                    (for example: -F/var/run/fsfreezehook.sh)\n"
250 #endif
251 "  -t, --statedir    specify dir to store state information (absolute paths\n"
252 "                    only, default is %s)\n"
253 "  -v, --verbose     log extra debugging information\n"
254 "  -V, --version     print version information and exit\n"
255 "  -d, --daemonize   become a daemon\n"
256 #ifdef _WIN32
257 "  -s, --service     service commands: install, uninstall, vss-install, vss-uninstall\n"
258 #endif
259 "  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\"\n"
260 "                    to list available RPCs)\n"
261 "  -D, --dump-conf   dump a qemu-ga config file based on current config\n"
262 "                    options / command-line parameters to stdout\n"
263 "  -r, --retry-path  attempt re-opening path if it's unavailable or closed\n"
264 "                    due to an error which may be recoverable in the future\n"
265 "                    (virtio-serial driver re-install, serial device hot\n"
266 "                    plug/unplug, etc.)\n"
267 "  -h, --help        display this help and exit\n"
268 "\n"
269 QEMU_HELP_BOTTOM "\n"
270     , cmd, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT,
271     dfl_pathnames.pidfile,
272 #ifdef CONFIG_FSFREEZE
273     QGA_FSFREEZE_HOOK_DEFAULT,
274 #endif
275     dfl_pathnames.state_dir);
276 }
277 
278 static const char *ga_log_level_str(GLogLevelFlags level)
279 {
280     switch (level & G_LOG_LEVEL_MASK) {
281     case G_LOG_LEVEL_ERROR:
282         return "error";
283     case G_LOG_LEVEL_CRITICAL:
284         return "critical";
285     case G_LOG_LEVEL_WARNING:
286         return "warning";
287     case G_LOG_LEVEL_MESSAGE:
288         return "message";
289     case G_LOG_LEVEL_INFO:
290         return "info";
291     case G_LOG_LEVEL_DEBUG:
292         return "debug";
293     default:
294         return "user";
295     }
296 }
297 
298 bool ga_logging_enabled(GAState *s)
299 {
300     return s->logging_enabled;
301 }
302 
303 void ga_disable_logging(GAState *s)
304 {
305     s->logging_enabled = false;
306 }
307 
308 void ga_enable_logging(GAState *s)
309 {
310     s->logging_enabled = true;
311 }
312 
313 static void ga_log(const gchar *domain, GLogLevelFlags level,
314                    const gchar *msg, gpointer opaque)
315 {
316     GAState *s = opaque;
317     const char *level_str = ga_log_level_str(level);
318 
319     if (!ga_logging_enabled(s)) {
320         return;
321     }
322 
323     level &= G_LOG_LEVEL_MASK;
324 #ifndef _WIN32
325     if (g_strcmp0(domain, "syslog") == 0) {
326         syslog(LOG_INFO, "%s: %s", level_str, msg);
327     } else if (level & s->log_level) {
328 #else
329     if (level & s->log_level) {
330 #endif
331         gint64 t = g_get_real_time();
332         fprintf(s->log_file,
333                 "%" G_GINT64_FORMAT ".%" G_GINT64_FORMAT
334                 ": %s: %s\n", t / G_USEC_PER_SEC, t % G_USEC_PER_SEC,
335                 level_str, msg);
336         fflush(s->log_file);
337     }
338 }
339 
340 void ga_set_response_delimited(GAState *s)
341 {
342     s->delimit_response = true;
343 }
344 
345 static FILE *ga_open_logfile(const char *logfile)
346 {
347     FILE *f;
348 
349     f = fopen(logfile, "a");
350     if (!f) {
351         return NULL;
352     }
353 
354     qemu_set_cloexec(fileno(f));
355     return f;
356 }
357 
358 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
359 {
360     return strcmp(str1, str2);
361 }
362 
363 /* disable commands that aren't safe for fsfreeze */
364 static void ga_disable_non_whitelisted(const QmpCommand *cmd, void *opaque)
365 {
366     bool whitelisted = false;
367     int i = 0;
368     const char *name = qmp_command_name(cmd);
369 
370     while (ga_freeze_whitelist[i] != NULL) {
371         if (strcmp(name, ga_freeze_whitelist[i]) == 0) {
372             whitelisted = true;
373         }
374         i++;
375     }
376     if (!whitelisted) {
377         g_debug("disabling command: %s", name);
378         qmp_disable_command(&ga_commands, name, "the agent is in frozen state");
379     }
380 }
381 
382 /* [re-]enable all commands, except those explicitly blacklisted by user */
383 static void ga_enable_non_blacklisted(const QmpCommand *cmd, void *opaque)
384 {
385     GList *blacklist = opaque;
386     const char *name = qmp_command_name(cmd);
387 
388     if (g_list_find_custom(blacklist, name, ga_strcmp) == NULL &&
389         !qmp_command_is_enabled(cmd)) {
390         g_debug("enabling command: %s", name);
391         qmp_enable_command(&ga_commands, name);
392     }
393 }
394 
395 static bool ga_create_file(const char *path)
396 {
397     int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
398     if (fd == -1) {
399         g_warning("unable to open/create file %s: %s", path, strerror(errno));
400         return false;
401     }
402     close(fd);
403     return true;
404 }
405 
406 static bool ga_delete_file(const char *path)
407 {
408     int ret = unlink(path);
409     if (ret == -1) {
410         g_warning("unable to delete file: %s: %s", path, strerror(errno));
411         return false;
412     }
413 
414     return true;
415 }
416 
417 bool ga_is_frozen(GAState *s)
418 {
419     return s->frozen;
420 }
421 
422 void ga_set_frozen(GAState *s)
423 {
424     if (ga_is_frozen(s)) {
425         return;
426     }
427     /* disable all non-whitelisted (for frozen state) commands */
428     qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
429     g_warning("disabling logging due to filesystem freeze");
430     ga_disable_logging(s);
431     s->frozen = true;
432     if (!ga_create_file(s->state_filepath_isfrozen)) {
433         g_warning("unable to create %s, fsfreeze may not function properly",
434                   s->state_filepath_isfrozen);
435     }
436 }
437 
438 void ga_unset_frozen(GAState *s)
439 {
440     if (!ga_is_frozen(s)) {
441         return;
442     }
443 
444     /* if we delayed creation/opening of pid/log files due to being
445      * in a frozen state at start up, do it now
446      */
447     if (s->deferred_options.log_filepath) {
448         s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
449         if (!s->log_file) {
450             s->log_file = stderr;
451         }
452         s->deferred_options.log_filepath = NULL;
453     }
454     ga_enable_logging(s);
455     g_warning("logging re-enabled due to filesystem unfreeze");
456     if (s->deferred_options.pid_filepath) {
457         Error *err = NULL;
458 
459         if (!qemu_write_pidfile(s->deferred_options.pid_filepath, &err)) {
460             g_warning("%s", error_get_pretty(err));
461             error_free(err);
462         }
463         s->deferred_options.pid_filepath = NULL;
464     }
465 
466     /* enable all disabled, non-blacklisted commands */
467     qmp_for_each_command(&ga_commands, ga_enable_non_blacklisted, s->blacklist);
468     s->frozen = false;
469     if (!ga_delete_file(s->state_filepath_isfrozen)) {
470         g_warning("unable to delete %s, fsfreeze may not function properly",
471                   s->state_filepath_isfrozen);
472     }
473 }
474 
475 #ifdef CONFIG_FSFREEZE
476 const char *ga_fsfreeze_hook(GAState *s)
477 {
478     return s->fsfreeze_hook;
479 }
480 #endif
481 
482 static void become_daemon(const char *pidfile)
483 {
484 #ifndef _WIN32
485     pid_t pid, sid;
486 
487     pid = fork();
488     if (pid < 0) {
489         exit(EXIT_FAILURE);
490     }
491     if (pid > 0) {
492         exit(EXIT_SUCCESS);
493     }
494 
495     if (pidfile) {
496         Error *err = NULL;
497 
498         if (!qemu_write_pidfile(pidfile, &err)) {
499             g_critical("%s", error_get_pretty(err));
500             error_free(err);
501             exit(EXIT_FAILURE);
502         }
503     }
504 
505     umask(S_IRWXG | S_IRWXO);
506     sid = setsid();
507     if (sid < 0) {
508         goto fail;
509     }
510     if ((chdir("/")) < 0) {
511         goto fail;
512     }
513 
514     reopen_fd_to_null(STDIN_FILENO);
515     reopen_fd_to_null(STDOUT_FILENO);
516     reopen_fd_to_null(STDERR_FILENO);
517     return;
518 
519 fail:
520     if (pidfile) {
521         unlink(pidfile);
522     }
523     g_critical("failed to daemonize");
524     exit(EXIT_FAILURE);
525 #endif
526 }
527 
528 static int send_response(GAState *s, const QDict *rsp)
529 {
530     GString *response;
531     GIOStatus status;
532 
533     g_assert(s->channel);
534 
535     if (!rsp) {
536         return 0;
537     }
538 
539     response = qobject_to_json(QOBJECT(rsp));
540     if (!response) {
541         return -EINVAL;
542     }
543 
544     if (s->delimit_response) {
545         s->delimit_response = false;
546         g_string_prepend_c(response, QGA_SENTINEL_BYTE);
547     }
548 
549     g_string_append_c(response, '\n');
550     status = ga_channel_write_all(s->channel, response->str, response->len);
551     g_string_free(response, true);
552     if (status != G_IO_STATUS_NORMAL) {
553         return -EIO;
554     }
555 
556     return 0;
557 }
558 
559 /* handle requests/control events coming in over the channel */
560 static void process_event(void *opaque, QObject *obj, Error *err)
561 {
562     GAState *s = opaque;
563     QDict *rsp;
564     int ret;
565 
566     g_debug("process_event: called");
567     assert(!obj != !err);
568     if (err) {
569         rsp = qmp_error_response(err);
570         goto end;
571     }
572 
573     g_debug("processing command");
574     rsp = qmp_dispatch(&ga_commands, obj, false, NULL);
575 
576 end:
577     ret = send_response(s, rsp);
578     if (ret < 0) {
579         g_warning("error sending error response: %s", strerror(-ret));
580     }
581     qobject_unref(rsp);
582     qobject_unref(obj);
583 }
584 
585 /* false return signals GAChannel to close the current client connection */
586 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
587 {
588     GAState *s = data;
589     gchar buf[QGA_READ_COUNT_DEFAULT + 1];
590     gsize count;
591     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
592     switch (status) {
593     case G_IO_STATUS_ERROR:
594         g_warning("error reading channel");
595         stop_agent(s, false);
596         return false;
597     case G_IO_STATUS_NORMAL:
598         buf[count] = 0;
599         g_debug("read data, count: %d, data: %s", (int)count, buf);
600         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
601         break;
602     case G_IO_STATUS_EOF:
603         g_debug("received EOF");
604         if (!s->virtio) {
605             return false;
606         }
607         /* fall through */
608     case G_IO_STATUS_AGAIN:
609         /* virtio causes us to spin here when no process is attached to
610          * host-side chardev. sleep a bit to mitigate this
611          */
612         if (s->virtio) {
613             g_usleep(G_USEC_PER_SEC / 10);
614         }
615         return true;
616     default:
617         g_warning("unknown channel read status, closing");
618         return false;
619     }
620     return true;
621 }
622 
623 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path,
624                              int listen_fd)
625 {
626     GAChannelMethod channel_method;
627 
628     if (strcmp(method, "virtio-serial") == 0) {
629         s->virtio = true; /* virtio requires special handling in some cases */
630         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
631     } else if (strcmp(method, "isa-serial") == 0) {
632         channel_method = GA_CHANNEL_ISA_SERIAL;
633     } else if (strcmp(method, "unix-listen") == 0) {
634         channel_method = GA_CHANNEL_UNIX_LISTEN;
635     } else if (strcmp(method, "vsock-listen") == 0) {
636         channel_method = GA_CHANNEL_VSOCK_LISTEN;
637     } else {
638         g_critical("unsupported channel method/type: %s", method);
639         return false;
640     }
641 
642     s->channel = ga_channel_new(channel_method, path, listen_fd,
643                                 channel_event_cb, s);
644     if (!s->channel) {
645         g_critical("failed to create guest agent channel");
646         return false;
647     }
648 
649     return true;
650 }
651 
652 #ifdef _WIN32
653 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data)
654 {
655     DWORD ret = NO_ERROR;
656     PDEV_BROADCAST_HDR broadcast_header = (PDEV_BROADCAST_HDR)data;
657 
658     if (broadcast_header->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE) {
659         switch (type) {
660             /* Device inserted */
661         case DBT_DEVICEARRIVAL:
662             /* Start QEMU-ga's service */
663             if (!SetEvent(ga_state->wakeup_event)) {
664                 ret = GetLastError();
665             }
666             break;
667             /* Device removed */
668         case DBT_DEVICEQUERYREMOVE:
669         case DBT_DEVICEREMOVEPENDING:
670         case DBT_DEVICEREMOVECOMPLETE:
671             /* Stop QEMU-ga's service */
672             if (!ResetEvent(ga_state->wakeup_event)) {
673                 ret = GetLastError();
674             }
675             break;
676         default:
677             ret = ERROR_CALL_NOT_IMPLEMENTED;
678         }
679     }
680     return ret;
681 }
682 
683 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
684                                   LPVOID ctx)
685 {
686     DWORD ret = NO_ERROR;
687     GAService *service = &ga_state->service;
688 
689     switch (ctrl) {
690     case SERVICE_CONTROL_STOP:
691     case SERVICE_CONTROL_SHUTDOWN:
692         quit_handler(SIGTERM);
693         SetEvent(ga_state->wakeup_event);
694         service->status.dwCurrentState = SERVICE_STOP_PENDING;
695         SetServiceStatus(service->status_handle, &service->status);
696         break;
697     case SERVICE_CONTROL_DEVICEEVENT:
698         handle_serial_device_events(type, data);
699         break;
700 
701     default:
702         ret = ERROR_CALL_NOT_IMPLEMENTED;
703     }
704     return ret;
705 }
706 
707 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
708 {
709     GAService *service = &ga_state->service;
710 
711     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
712         service_ctrl_handler, NULL);
713 
714     if (service->status_handle == 0) {
715         g_critical("Failed to register extended requests function!\n");
716         return;
717     }
718 
719     service->status.dwServiceType = SERVICE_WIN32;
720     service->status.dwCurrentState = SERVICE_RUNNING;
721     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
722     service->status.dwWin32ExitCode = NO_ERROR;
723     service->status.dwServiceSpecificExitCode = NO_ERROR;
724     service->status.dwCheckPoint = 0;
725     service->status.dwWaitHint = 0;
726     DEV_BROADCAST_DEVICEINTERFACE notification_filter;
727     ZeroMemory(&notification_filter, sizeof(notification_filter));
728     notification_filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
729     notification_filter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
730     notification_filter.dbcc_classguid = GUID_VIOSERIAL_PORT;
731 
732     service->device_notification_handle =
733         RegisterDeviceNotification(service->status_handle,
734             &notification_filter, DEVICE_NOTIFY_SERVICE_HANDLE);
735     if (!service->device_notification_handle) {
736         g_critical("Failed to register device notification handle!\n");
737         return;
738     }
739     SetServiceStatus(service->status_handle, &service->status);
740 
741     run_agent(ga_state);
742 
743     UnregisterDeviceNotification(service->device_notification_handle);
744     service->status.dwCurrentState = SERVICE_STOPPED;
745     SetServiceStatus(service->status_handle, &service->status);
746 }
747 #endif
748 
749 static void set_persistent_state_defaults(GAPersistentState *pstate)
750 {
751     g_assert(pstate);
752     pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
753 }
754 
755 static void persistent_state_from_keyfile(GAPersistentState *pstate,
756                                           GKeyFile *keyfile)
757 {
758     g_assert(pstate);
759     g_assert(keyfile);
760     /* if any fields are missing, either because the file was tampered with
761      * by agents of chaos, or because the field wasn't present at the time the
762      * file was created, the best we can ever do is start over with the default
763      * values. so load them now, and ignore any errors in accessing key-value
764      * pairs
765      */
766     set_persistent_state_defaults(pstate);
767 
768     if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
769         pstate->fd_counter =
770             g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
771     }
772 }
773 
774 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
775                                         GKeyFile *keyfile)
776 {
777     g_assert(pstate);
778     g_assert(keyfile);
779 
780     g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
781 }
782 
783 static gboolean write_persistent_state(const GAPersistentState *pstate,
784                                        const gchar *path)
785 {
786     GKeyFile *keyfile = g_key_file_new();
787     GError *gerr = NULL;
788     gboolean ret = true;
789     gchar *data = NULL;
790     gsize data_len;
791 
792     g_assert(pstate);
793 
794     persistent_state_to_keyfile(pstate, keyfile);
795     data = g_key_file_to_data(keyfile, &data_len, &gerr);
796     if (gerr) {
797         g_critical("failed to convert persistent state to string: %s",
798                    gerr->message);
799         ret = false;
800         goto out;
801     }
802 
803     g_file_set_contents(path, data, data_len, &gerr);
804     if (gerr) {
805         g_critical("failed to write persistent state to %s: %s",
806                     path, gerr->message);
807         ret = false;
808         goto out;
809     }
810 
811 out:
812     if (gerr) {
813         g_error_free(gerr);
814     }
815     if (keyfile) {
816         g_key_file_free(keyfile);
817     }
818     g_free(data);
819     return ret;
820 }
821 
822 static gboolean read_persistent_state(GAPersistentState *pstate,
823                                       const gchar *path, gboolean frozen)
824 {
825     GKeyFile *keyfile = NULL;
826     GError *gerr = NULL;
827     struct stat st;
828     gboolean ret = true;
829 
830     g_assert(pstate);
831 
832     if (stat(path, &st) == -1) {
833         /* it's okay if state file doesn't exist, but any other error
834          * indicates a permissions issue or some other misconfiguration
835          * that we likely won't be able to recover from.
836          */
837         if (errno != ENOENT) {
838             g_critical("unable to access state file at path %s: %s",
839                        path, strerror(errno));
840             ret = false;
841             goto out;
842         }
843 
844         /* file doesn't exist. initialize state to default values and
845          * attempt to save now. (we could wait till later when we have
846          * modified state we need to commit, but if there's a problem,
847          * such as a missing parent directory, we want to catch it now)
848          *
849          * there is a potential scenario where someone either managed to
850          * update the agent from a version that didn't use a key store
851          * while qemu-ga thought the filesystem was frozen, or
852          * deleted the key store prior to issuing a fsfreeze, prior
853          * to restarting the agent. in this case we go ahead and defer
854          * initial creation till we actually have modified state to
855          * write, otherwise fail to recover from freeze.
856          */
857         set_persistent_state_defaults(pstate);
858         if (!frozen) {
859             ret = write_persistent_state(pstate, path);
860             if (!ret) {
861                 g_critical("unable to create state file at path %s", path);
862                 ret = false;
863                 goto out;
864             }
865         }
866         ret = true;
867         goto out;
868     }
869 
870     keyfile = g_key_file_new();
871     g_key_file_load_from_file(keyfile, path, 0, &gerr);
872     if (gerr) {
873         g_critical("error loading persistent state from path: %s, %s",
874                    path, gerr->message);
875         ret = false;
876         goto out;
877     }
878 
879     persistent_state_from_keyfile(pstate, keyfile);
880 
881 out:
882     if (keyfile) {
883         g_key_file_free(keyfile);
884     }
885     if (gerr) {
886         g_error_free(gerr);
887     }
888 
889     return ret;
890 }
891 
892 int64_t ga_get_fd_handle(GAState *s, Error **errp)
893 {
894     int64_t handle;
895 
896     g_assert(s->pstate_filepath);
897     /* we blacklist commands and avoid operations that potentially require
898      * writing to disk when we're in a frozen state. this includes opening
899      * new files, so we should never get here in that situation
900      */
901     g_assert(!ga_is_frozen(s));
902 
903     handle = s->pstate.fd_counter++;
904 
905     /* This should never happen on a reasonable timeframe, as guest-file-open
906      * would have to be issued 2^63 times */
907     if (s->pstate.fd_counter == INT64_MAX) {
908         abort();
909     }
910 
911     if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
912         error_setg(errp, "failed to commit persistent state to disk");
913         return -1;
914     }
915 
916     return handle;
917 }
918 
919 static void ga_print_cmd(const QmpCommand *cmd, void *opaque)
920 {
921     printf("%s\n", qmp_command_name(cmd));
922 }
923 
924 static GList *split_list(const gchar *str, const gchar *delim)
925 {
926     GList *list = NULL;
927     int i;
928     gchar **strv;
929 
930     strv = g_strsplit(str, delim, -1);
931     for (i = 0; strv[i]; i++) {
932         list = g_list_prepend(list, strv[i]);
933     }
934     g_free(strv);
935 
936     return list;
937 }
938 
939 struct GAConfig {
940     char *channel_path;
941     char *method;
942     char *log_filepath;
943     char *pid_filepath;
944 #ifdef CONFIG_FSFREEZE
945     char *fsfreeze_hook;
946 #endif
947     char *state_dir;
948 #ifdef _WIN32
949     const char *service;
950 #endif
951     gchar *bliststr; /* blacklist may point to this string */
952     GList *blacklist;
953     int daemonize;
954     GLogLevelFlags log_level;
955     int dumpconf;
956     bool retry_path;
957 };
958 
959 static void config_load(GAConfig *config)
960 {
961     GError *gerr = NULL;
962     GKeyFile *keyfile;
963     g_autofree char *conf = g_strdup(g_getenv("QGA_CONF")) ?: get_relocated_path(QGA_CONF_DEFAULT);
964 
965     /* read system config */
966     keyfile = g_key_file_new();
967     if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
968         goto end;
969     }
970     if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
971         config->daemonize =
972             g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
973     }
974     if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
975         config->method =
976             g_key_file_get_string(keyfile, "general", "method", &gerr);
977     }
978     if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
979         config->channel_path =
980             g_key_file_get_string(keyfile, "general", "path", &gerr);
981     }
982     if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
983         config->log_filepath =
984             g_key_file_get_string(keyfile, "general", "logfile", &gerr);
985     }
986     if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
987         config->pid_filepath =
988             g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
989     }
990 #ifdef CONFIG_FSFREEZE
991     if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
992         config->fsfreeze_hook =
993             g_key_file_get_string(keyfile,
994                                   "general", "fsfreeze-hook", &gerr);
995     }
996 #endif
997     if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
998         config->state_dir =
999             g_key_file_get_string(keyfile, "general", "statedir", &gerr);
1000     }
1001     if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
1002         g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
1003         /* enable all log levels */
1004         config->log_level = G_LOG_LEVEL_MASK;
1005     }
1006     if (g_key_file_has_key(keyfile, "general", "retry-path", NULL)) {
1007         config->retry_path =
1008             g_key_file_get_boolean(keyfile, "general", "retry-path", &gerr);
1009     }
1010     if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
1011         config->bliststr =
1012             g_key_file_get_string(keyfile, "general", "blacklist", &gerr);
1013         config->blacklist = g_list_concat(config->blacklist,
1014                                           split_list(config->bliststr, ","));
1015     }
1016 
1017 end:
1018     g_key_file_free(keyfile);
1019     if (gerr &&
1020         !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
1021         g_critical("error loading configuration from path: %s, %s",
1022                    conf, gerr->message);
1023         exit(EXIT_FAILURE);
1024     }
1025     g_clear_error(&gerr);
1026 }
1027 
1028 static gchar *list_join(GList *list, const gchar separator)
1029 {
1030     GString *str = g_string_new("");
1031 
1032     while (list) {
1033         str = g_string_append(str, (gchar *)list->data);
1034         list = g_list_next(list);
1035         if (list) {
1036             str = g_string_append_c(str, separator);
1037         }
1038     }
1039 
1040     return g_string_free(str, FALSE);
1041 }
1042 
1043 static void config_dump(GAConfig *config)
1044 {
1045     GError *error = NULL;
1046     GKeyFile *keyfile;
1047     gchar *tmp;
1048 
1049     keyfile = g_key_file_new();
1050     g_assert(keyfile);
1051 
1052     g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1053     g_key_file_set_string(keyfile, "general", "method", config->method);
1054     if (config->channel_path) {
1055         g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1056     }
1057     if (config->log_filepath) {
1058         g_key_file_set_string(keyfile, "general", "logfile",
1059                               config->log_filepath);
1060     }
1061     g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1062 #ifdef CONFIG_FSFREEZE
1063     if (config->fsfreeze_hook) {
1064         g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1065                               config->fsfreeze_hook);
1066     }
1067 #endif
1068     g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1069     g_key_file_set_boolean(keyfile, "general", "verbose",
1070                            config->log_level == G_LOG_LEVEL_MASK);
1071     g_key_file_set_boolean(keyfile, "general", "retry-path",
1072                            config->retry_path);
1073     tmp = list_join(config->blacklist, ',');
1074     g_key_file_set_string(keyfile, "general", "blacklist", tmp);
1075     g_free(tmp);
1076 
1077     tmp = g_key_file_to_data(keyfile, NULL, &error);
1078     if (error) {
1079         g_critical("Failed to dump keyfile: %s", error->message);
1080         g_clear_error(&error);
1081     } else {
1082         printf("%s", tmp);
1083     }
1084 
1085     g_free(tmp);
1086     g_key_file_free(keyfile);
1087 }
1088 
1089 static void config_parse(GAConfig *config, int argc, char **argv)
1090 {
1091     const char *sopt = "hVvdm:p:l:f:F::b:s:t:Dr";
1092     int opt_ind = 0, ch;
1093     const struct option lopt[] = {
1094         { "help", 0, NULL, 'h' },
1095         { "version", 0, NULL, 'V' },
1096         { "dump-conf", 0, NULL, 'D' },
1097         { "logfile", 1, NULL, 'l' },
1098         { "pidfile", 1, NULL, 'f' },
1099 #ifdef CONFIG_FSFREEZE
1100         { "fsfreeze-hook", 2, NULL, 'F' },
1101 #endif
1102         { "verbose", 0, NULL, 'v' },
1103         { "method", 1, NULL, 'm' },
1104         { "path", 1, NULL, 'p' },
1105         { "daemonize", 0, NULL, 'd' },
1106         { "blacklist", 1, NULL, 'b' },
1107 #ifdef _WIN32
1108         { "service", 1, NULL, 's' },
1109 #endif
1110         { "statedir", 1, NULL, 't' },
1111         { "retry-path", 0, NULL, 'r' },
1112         { NULL, 0, NULL, 0 }
1113     };
1114 
1115     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1116         switch (ch) {
1117         case 'm':
1118             g_free(config->method);
1119             config->method = g_strdup(optarg);
1120             break;
1121         case 'p':
1122             g_free(config->channel_path);
1123             config->channel_path = g_strdup(optarg);
1124             break;
1125         case 'l':
1126             g_free(config->log_filepath);
1127             config->log_filepath = g_strdup(optarg);
1128             break;
1129         case 'f':
1130             g_free(config->pid_filepath);
1131             config->pid_filepath = g_strdup(optarg);
1132             break;
1133 #ifdef CONFIG_FSFREEZE
1134         case 'F':
1135             g_free(config->fsfreeze_hook);
1136             config->fsfreeze_hook = optarg ? g_strdup(optarg) : get_relocated_path(QGA_FSFREEZE_HOOK_DEFAULT);
1137             break;
1138 #endif
1139         case 't':
1140             g_free(config->state_dir);
1141             config->state_dir = g_strdup(optarg);
1142             break;
1143         case 'v':
1144             /* enable all log levels */
1145             config->log_level = G_LOG_LEVEL_MASK;
1146             break;
1147         case 'V':
1148             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1149             exit(EXIT_SUCCESS);
1150         case 'd':
1151             config->daemonize = 1;
1152             break;
1153         case 'D':
1154             config->dumpconf = 1;
1155             break;
1156         case 'r':
1157             config->retry_path = true;
1158             break;
1159         case 'b': {
1160             if (is_help_option(optarg)) {
1161                 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1162                 exit(EXIT_SUCCESS);
1163             }
1164             config->blacklist = g_list_concat(config->blacklist,
1165                                              split_list(optarg, ","));
1166             break;
1167         }
1168 #ifdef _WIN32
1169         case 's':
1170             config->service = optarg;
1171             if (strcmp(config->service, "install") == 0) {
1172                 if (ga_install_vss_provider()) {
1173                     exit(EXIT_FAILURE);
1174                 }
1175                 if (ga_install_service(config->channel_path,
1176                                        config->log_filepath, config->state_dir)) {
1177                     exit(EXIT_FAILURE);
1178                 }
1179                 exit(EXIT_SUCCESS);
1180             } else if (strcmp(config->service, "uninstall") == 0) {
1181                 ga_uninstall_vss_provider();
1182                 exit(ga_uninstall_service());
1183             } else if (strcmp(config->service, "vss-install") == 0) {
1184                 if (ga_install_vss_provider()) {
1185                     exit(EXIT_FAILURE);
1186                 }
1187                 exit(EXIT_SUCCESS);
1188             } else if (strcmp(config->service, "vss-uninstall") == 0) {
1189                 ga_uninstall_vss_provider();
1190                 exit(EXIT_SUCCESS);
1191             } else {
1192                 printf("Unknown service command.\n");
1193                 exit(EXIT_FAILURE);
1194             }
1195             break;
1196 #endif
1197         case 'h':
1198             usage(argv[0]);
1199             exit(EXIT_SUCCESS);
1200         case '?':
1201             g_print("Unknown option, try '%s --help' for more information.\n",
1202                     argv[0]);
1203             exit(EXIT_FAILURE);
1204         }
1205     }
1206 }
1207 
1208 static void config_free(GAConfig *config)
1209 {
1210     g_free(config->method);
1211     g_free(config->log_filepath);
1212     g_free(config->pid_filepath);
1213     g_free(config->state_dir);
1214     g_free(config->channel_path);
1215     g_free(config->bliststr);
1216 #ifdef CONFIG_FSFREEZE
1217     g_free(config->fsfreeze_hook);
1218 #endif
1219     g_list_free_full(config->blacklist, g_free);
1220     g_free(config);
1221 }
1222 
1223 static bool check_is_frozen(GAState *s)
1224 {
1225 #ifndef _WIN32
1226     /* check if a previous instance of qemu-ga exited with filesystems' state
1227      * marked as frozen. this could be a stale value (a non-qemu-ga process
1228      * or reboot may have since unfrozen them), but better to require an
1229      * uneeded unfreeze than to risk hanging on start-up
1230      */
1231     struct stat st;
1232     if (stat(s->state_filepath_isfrozen, &st) == -1) {
1233         /* it's okay if the file doesn't exist, but if we can't access for
1234          * some other reason, such as permissions, there's a configuration
1235          * that needs to be addressed. so just bail now before we get into
1236          * more trouble later
1237          */
1238         if (errno != ENOENT) {
1239             g_critical("unable to access state file at path %s: %s",
1240                        s->state_filepath_isfrozen, strerror(errno));
1241             return EXIT_FAILURE;
1242         }
1243     } else {
1244         g_warning("previous instance appears to have exited with frozen"
1245                   " filesystems. deferring logging/pidfile creation and"
1246                   " disabling non-fsfreeze-safe commands until"
1247                   " guest-fsfreeze-thaw is issued, or filesystems are"
1248                   " manually unfrozen and the file %s is removed",
1249                   s->state_filepath_isfrozen);
1250         return true;
1251     }
1252 #endif
1253     return false;
1254 }
1255 
1256 static GAState *initialize_agent(GAConfig *config, int socket_activation)
1257 {
1258     GAState *s = g_new0(GAState, 1);
1259 
1260     g_assert(ga_state == NULL);
1261 
1262     s->log_level = config->log_level;
1263     s->log_file = stderr;
1264 #ifdef CONFIG_FSFREEZE
1265     s->fsfreeze_hook = config->fsfreeze_hook;
1266 #endif
1267     s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1268     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1269                                                  config->state_dir);
1270     s->frozen = check_is_frozen(s);
1271 
1272     g_log_set_default_handler(ga_log, s);
1273     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1274     ga_enable_logging(s);
1275 
1276 #ifdef _WIN32
1277     /* On win32 the state directory is application specific (be it the default
1278      * or a user override). We got past the command line parsing; let's create
1279      * the directory (with any intermediate directories). If we run into an
1280      * error later on, we won't try to clean up the directory, it is considered
1281      * persistent.
1282      */
1283     if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1284         g_critical("unable to create (an ancestor of) the state directory"
1285                    " '%s': %s", config->state_dir, strerror(errno));
1286         return NULL;
1287     }
1288 #endif
1289 
1290     if (ga_is_frozen(s)) {
1291         if (config->daemonize) {
1292             /* delay opening/locking of pidfile till filesystems are unfrozen */
1293             s->deferred_options.pid_filepath = config->pid_filepath;
1294             become_daemon(NULL);
1295         }
1296         if (config->log_filepath) {
1297             /* delay opening the log file till filesystems are unfrozen */
1298             s->deferred_options.log_filepath = config->log_filepath;
1299         }
1300         ga_disable_logging(s);
1301         qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
1302     } else {
1303         if (config->daemonize) {
1304             become_daemon(config->pid_filepath);
1305         }
1306         if (config->log_filepath) {
1307             FILE *log_file = ga_open_logfile(config->log_filepath);
1308             if (!log_file) {
1309                 g_critical("unable to open specified log file: %s",
1310                            strerror(errno));
1311                 return NULL;
1312             }
1313             s->log_file = log_file;
1314         }
1315     }
1316 
1317     /* load persistent state from disk */
1318     if (!read_persistent_state(&s->pstate,
1319                                s->pstate_filepath,
1320                                ga_is_frozen(s))) {
1321         g_critical("failed to load persistent state");
1322         return NULL;
1323     }
1324 
1325     config->blacklist = ga_command_blacklist_init(config->blacklist);
1326     if (config->blacklist) {
1327         GList *l = config->blacklist;
1328         s->blacklist = config->blacklist;
1329         do {
1330             g_debug("disabling command: %s", (char *)l->data);
1331             qmp_disable_command(&ga_commands, l->data, NULL);
1332             l = g_list_next(l);
1333         } while (l);
1334     }
1335     s->command_state = ga_command_state_new();
1336     ga_command_state_init(s, s->command_state);
1337     ga_command_state_init_all(s->command_state);
1338     json_message_parser_init(&s->parser, process_event, s, NULL);
1339 
1340 #ifndef _WIN32
1341     if (!register_signal_handlers()) {
1342         g_critical("failed to register signal handlers");
1343         return NULL;
1344     }
1345 #endif
1346 
1347     s->main_loop = g_main_loop_new(NULL, false);
1348 
1349     s->config = config;
1350     s->socket_activation = socket_activation;
1351 
1352 #ifdef _WIN32
1353     s->wakeup_event = CreateEvent(NULL, TRUE, FALSE, TEXT("WakeUp"));
1354     if (s->wakeup_event == NULL) {
1355         g_critical("CreateEvent failed");
1356         return NULL;
1357     }
1358 #endif
1359 
1360     ga_state = s;
1361     return s;
1362 }
1363 
1364 static void cleanup_agent(GAState *s)
1365 {
1366 #ifdef _WIN32
1367     CloseHandle(s->wakeup_event);
1368 #endif
1369     if (s->command_state) {
1370         ga_command_state_cleanup_all(s->command_state);
1371         ga_command_state_free(s->command_state);
1372         json_message_parser_destroy(&s->parser);
1373     }
1374     g_free(s->pstate_filepath);
1375     g_free(s->state_filepath_isfrozen);
1376     if (s->main_loop) {
1377         g_main_loop_unref(s->main_loop);
1378     }
1379     g_free(s);
1380     ga_state = NULL;
1381 }
1382 
1383 static int run_agent_once(GAState *s)
1384 {
1385     if (!channel_init(s, s->config->method, s->config->channel_path,
1386                       s->socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
1387         g_critical("failed to initialize guest agent channel");
1388         return EXIT_FAILURE;
1389     }
1390 
1391     g_main_loop_run(ga_state->main_loop);
1392 
1393     if (s->channel) {
1394         ga_channel_free(s->channel);
1395     }
1396 
1397     return EXIT_SUCCESS;
1398 }
1399 
1400 static void wait_for_channel_availability(GAState *s)
1401 {
1402     g_warning("waiting for channel path...");
1403 #ifndef _WIN32
1404     sleep(QGA_RETRY_INTERVAL);
1405 #else
1406     DWORD dwWaitResult;
1407 
1408     dwWaitResult = WaitForSingleObject(s->wakeup_event, INFINITE);
1409 
1410     switch (dwWaitResult) {
1411     case WAIT_OBJECT_0:
1412         break;
1413     case WAIT_TIMEOUT:
1414         break;
1415     default:
1416         g_critical("WaitForSingleObject failed");
1417     }
1418 #endif
1419 }
1420 
1421 static int run_agent(GAState *s)
1422 {
1423     int ret = EXIT_SUCCESS;
1424 
1425     s->force_exit = false;
1426 
1427     do {
1428         ret = run_agent_once(s);
1429         if (s->config->retry_path && !s->force_exit) {
1430             g_warning("agent stopped unexpectedly, restarting...");
1431             wait_for_channel_availability(s);
1432         }
1433     } while (s->config->retry_path && !s->force_exit);
1434 
1435     return ret;
1436 }
1437 
1438 static void stop_agent(GAState *s, bool requested)
1439 {
1440     if (!s->force_exit) {
1441         s->force_exit = requested;
1442     }
1443 
1444     if (g_main_loop_is_running(s->main_loop)) {
1445         g_main_loop_quit(s->main_loop);
1446     }
1447 }
1448 
1449 int main(int argc, char **argv)
1450 {
1451     int ret = EXIT_SUCCESS;
1452     GAState *s;
1453     GAConfig *config = g_new0(GAConfig, 1);
1454     int socket_activation;
1455 
1456     config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1457 
1458     qemu_init_exec_dir(argv[0]);
1459     qga_qmp_init_marshal(&ga_commands);
1460 
1461     init_dfl_pathnames();
1462     config_load(config);
1463     config_parse(config, argc, argv);
1464 
1465     if (config->pid_filepath == NULL) {
1466         config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1467     }
1468 
1469     if (config->state_dir == NULL) {
1470         config->state_dir = g_strdup(dfl_pathnames.state_dir);
1471     }
1472 
1473     if (config->method == NULL) {
1474         config->method = g_strdup("virtio-serial");
1475     }
1476 
1477     socket_activation = check_socket_activation();
1478     if (socket_activation > 1) {
1479         g_critical("qemu-ga only supports listening on one socket");
1480         ret = EXIT_FAILURE;
1481         goto end;
1482     }
1483     if (socket_activation) {
1484         SocketAddress *addr;
1485 
1486         g_free(config->method);
1487         g_free(config->channel_path);
1488         config->method = NULL;
1489         config->channel_path = NULL;
1490 
1491         addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL);
1492         if (addr) {
1493             if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
1494                 config->method = g_strdup("unix-listen");
1495             } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
1496                 config->method = g_strdup("vsock-listen");
1497             }
1498 
1499             qapi_free_SocketAddress(addr);
1500         }
1501 
1502         if (!config->method) {
1503             g_critical("unsupported listen fd type");
1504             ret = EXIT_FAILURE;
1505             goto end;
1506         }
1507     } else if (config->channel_path == NULL) {
1508         if (strcmp(config->method, "virtio-serial") == 0) {
1509             /* try the default path for the virtio-serial port */
1510             config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1511         } else if (strcmp(config->method, "isa-serial") == 0) {
1512             /* try the default path for the serial port - COM1 */
1513             config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1514         } else {
1515             g_critical("must specify a path for this channel");
1516             ret = EXIT_FAILURE;
1517             goto end;
1518         }
1519     }
1520 
1521     if (config->dumpconf) {
1522         config_dump(config);
1523         goto end;
1524     }
1525 
1526     s = initialize_agent(config, socket_activation);
1527     if (!s) {
1528         g_critical("error initializing guest agent");
1529         goto end;
1530     }
1531 
1532 #ifdef _WIN32
1533     if (config->daemonize) {
1534         SERVICE_TABLE_ENTRY service_table[] = {
1535             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1536         StartServiceCtrlDispatcher(service_table);
1537     } else {
1538         ret = run_agent(s);
1539     }
1540 #else
1541     ret = run_agent(s);
1542 #endif
1543 
1544     cleanup_agent(s);
1545 
1546 end:
1547     if (config->daemonize) {
1548         unlink(config->pid_filepath);
1549     }
1550 
1551     config_free(config);
1552 
1553     return ret;
1554 }
1555