xref: /openbmc/qemu/qga/main.c (revision e3a99063)
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-common.h"
22 #include "qapi/qmp/json-parser.h"
23 #include "qapi/qmp/qdict.h"
24 #include "qapi/qmp/qjson.h"
25 #include "qapi/qmp/qstring.h"
26 #include "guest-agent-core.h"
27 #include "qga-qapi-init-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 <dbt.h>
38 #include "qga/service-win32.h"
39 #include "qga/vss-win32.h"
40 #endif
41 #ifdef __linux__
42 #include <linux/fs.h>
43 #ifdef FIFREEZE
44 #define CONFIG_FSFREEZE
45 #endif
46 #endif
47 
48 #ifndef _WIN32
49 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
50 #define QGA_STATE_RELATIVE_DIR  "run"
51 #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
52 #else
53 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
54 #define QGA_STATE_RELATIVE_DIR  "qemu-ga"
55 #define QGA_SERIAL_PATH_DEFAULT "COM1"
56 #endif
57 #ifdef CONFIG_FSFREEZE
58 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
59 #endif
60 #define QGA_SENTINEL_BYTE 0xFF
61 #define QGA_CONF_DEFAULT CONFIG_QEMU_CONFDIR G_DIR_SEPARATOR_S "qemu-ga.conf"
62 #define QGA_RETRY_INTERVAL 5
63 
64 static struct {
65     const char *state_dir;
66     const char *pidfile;
67 } dfl_pathnames;
68 
69 typedef struct GAPersistentState {
70 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
71     int64_t fd_counter;
72 } GAPersistentState;
73 
74 typedef struct GAConfig GAConfig;
75 
76 struct GAState {
77     JSONMessageParser parser;
78     GMainLoop *main_loop;
79     GAChannel *channel;
80     bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
81     GACommandState *command_state;
82     GLogLevelFlags log_level;
83     FILE *log_file;
84     bool logging_enabled;
85 #ifdef _WIN32
86     GAService service;
87     HANDLE wakeup_event;
88 #endif
89     bool delimit_response;
90     bool frozen;
91     GList *blacklist;
92     char *state_filepath_isfrozen;
93     struct {
94         const char *log_filepath;
95         const char *pid_filepath;
96     } deferred_options;
97 #ifdef CONFIG_FSFREEZE
98     const char *fsfreeze_hook;
99 #endif
100     gchar *pstate_filepath;
101     GAPersistentState pstate;
102     GAConfig *config;
103     int socket_activation;
104     bool force_exit;
105 };
106 
107 struct GAState *ga_state;
108 QmpCommandList ga_commands;
109 
110 /* commands that are safe to issue while filesystems are frozen */
111 static const char *ga_freeze_whitelist[] = {
112     "guest-ping",
113     "guest-info",
114     "guest-sync",
115     "guest-sync-delimited",
116     "guest-fsfreeze-status",
117     "guest-fsfreeze-thaw",
118     NULL
119 };
120 
121 #ifdef _WIN32
122 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
123                                   LPVOID ctx);
124 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data);
125 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
126 #endif
127 static int run_agent(GAState *s);
128 static void stop_agent(GAState *s, bool requested);
129 
130 static void
131 init_dfl_pathnames(void)
132 {
133     g_assert(dfl_pathnames.state_dir == NULL);
134     g_assert(dfl_pathnames.pidfile == NULL);
135     dfl_pathnames.state_dir = qemu_get_local_state_pathname(
136       QGA_STATE_RELATIVE_DIR);
137     dfl_pathnames.pidfile   = qemu_get_local_state_pathname(
138       QGA_STATE_RELATIVE_DIR G_DIR_SEPARATOR_S "qemu-ga.pid");
139 }
140 
141 static void quit_handler(int sig)
142 {
143     /* if we're frozen, don't exit unless we're absolutely forced to,
144      * because it's basically impossible for graceful exit to complete
145      * unless all log/pid files are on unfreezable filesystems. there's
146      * also a very likely chance killing the agent before unfreezing
147      * the filesystems is a mistake (or will be viewed as one later).
148      * On Windows the freeze interval is limited to 10 seconds, so
149      * we should quit, but first we should wait for the timeout, thaw
150      * the filesystem and quit.
151      */
152     if (ga_is_frozen(ga_state)) {
153 #ifdef _WIN32
154         int i = 0;
155         Error *err = NULL;
156         HANDLE hEventTimeout;
157 
158         g_debug("Thawing filesystems before exiting");
159 
160         hEventTimeout = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_TIMEOUT);
161         if (hEventTimeout) {
162             WaitForSingleObject(hEventTimeout, 0);
163             CloseHandle(hEventTimeout);
164         }
165         qga_vss_fsfreeze(&i, false, NULL, &err);
166         if (err) {
167             g_debug("Error unfreezing filesystems prior to exiting: %s",
168                 error_get_pretty(err));
169             error_free(err);
170         }
171 #else
172         return;
173 #endif
174     }
175     g_debug("received signal num %d, quitting", sig);
176 
177     stop_agent(ga_state, true);
178 }
179 
180 #ifndef _WIN32
181 static gboolean register_signal_handlers(void)
182 {
183     struct sigaction sigact;
184     int ret;
185 
186     memset(&sigact, 0, sizeof(struct sigaction));
187     sigact.sa_handler = quit_handler;
188 
189     ret = sigaction(SIGINT, &sigact, NULL);
190     if (ret == -1) {
191         g_error("error configuring signal handler: %s", strerror(errno));
192     }
193     ret = sigaction(SIGTERM, &sigact, NULL);
194     if (ret == -1) {
195         g_error("error configuring signal handler: %s", strerror(errno));
196     }
197 
198     sigact.sa_handler = SIG_IGN;
199     if (sigaction(SIGPIPE, &sigact, NULL) != 0) {
200         g_error("error configuring SIGPIPE signal handler: %s",
201                 strerror(errno));
202     }
203 
204     return true;
205 }
206 
207 /* TODO: use this in place of all post-fork() fclose(std*) callers */
208 void reopen_fd_to_null(int fd)
209 {
210     int nullfd;
211 
212     nullfd = open("/dev/null", O_RDWR);
213     if (nullfd < 0) {
214         return;
215     }
216 
217     dup2(nullfd, fd);
218 
219     if (nullfd != fd) {
220         close(nullfd);
221     }
222 }
223 #endif
224 
225 static void usage(const char *cmd)
226 {
227     printf(
228 "Usage: %s [-m <method> -p <path>] [<options>]\n"
229 "QEMU Guest Agent " QEMU_FULL_VERSION "\n"
230 QEMU_COPYRIGHT "\n"
231 "\n"
232 "  -m, --method      transport method: one of unix-listen, virtio-serial,\n"
233 "                    isa-serial, or vsock-listen (virtio-serial is the default)\n"
234 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
235 "                    %s,\n"
236 "                    the default for isa-serial is:\n"
237 "                    %s).\n"
238 "                    Socket addresses for vsock-listen are written as\n"
239 "                    <cid>:<port>.\n"
240 "  -l, --logfile     set logfile path, logs to stderr by default\n"
241 "  -f, --pidfile     specify pidfile (default is %s)\n"
242 #ifdef CONFIG_FSFREEZE
243 "  -F, --fsfreeze-hook\n"
244 "                    enable fsfreeze hook. Accepts an optional argument that\n"
245 "                    specifies script to run on freeze/thaw. Script will be\n"
246 "                    called with 'freeze'/'thaw' arguments accordingly.\n"
247 "                    (default is %s)\n"
248 "                    If using -F with an argument, do not follow -F with a\n"
249 "                    space.\n"
250 "                    (for example: -F/var/run/fsfreezehook.sh)\n"
251 #endif
252 "  -t, --statedir    specify dir to store state information (absolute paths\n"
253 "                    only, default is %s)\n"
254 "  -v, --verbose     log extra debugging information\n"
255 "  -V, --version     print version information and exit\n"
256 "  -d, --daemonize   become a daemon\n"
257 #ifdef _WIN32
258 "  -s, --service     service commands: install, uninstall, vss-install, vss-uninstall\n"
259 #endif
260 "  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\"\n"
261 "                    to list available RPCs)\n"
262 "  -D, --dump-conf   dump a qemu-ga config file based on current config\n"
263 "                    options / command-line parameters to stdout\n"
264 "  -r, --retry-path  attempt re-opening path if it's unavailable or closed\n"
265 "                    due to an error which may be recoverable in the future\n"
266 "                    (virtio-serial driver re-install, serial device hot\n"
267 "                    plug/unplug, etc.)\n"
268 "  -h, --help        display this help and exit\n"
269 "\n"
270 QEMU_HELP_BOTTOM "\n"
271     , cmd, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT,
272     dfl_pathnames.pidfile,
273 #ifdef CONFIG_FSFREEZE
274     QGA_FSFREEZE_HOOK_DEFAULT,
275 #endif
276     dfl_pathnames.state_dir);
277 }
278 
279 static const char *ga_log_level_str(GLogLevelFlags level)
280 {
281     switch (level & G_LOG_LEVEL_MASK) {
282         case G_LOG_LEVEL_ERROR:
283             return "error";
284         case G_LOG_LEVEL_CRITICAL:
285             return "critical";
286         case G_LOG_LEVEL_WARNING:
287             return "warning";
288         case G_LOG_LEVEL_MESSAGE:
289             return "message";
290         case G_LOG_LEVEL_INFO:
291             return "info";
292         case G_LOG_LEVEL_DEBUG:
293             return "debug";
294         default:
295             return "user";
296     }
297 }
298 
299 bool ga_logging_enabled(GAState *s)
300 {
301     return s->logging_enabled;
302 }
303 
304 void ga_disable_logging(GAState *s)
305 {
306     s->logging_enabled = false;
307 }
308 
309 void ga_enable_logging(GAState *s)
310 {
311     s->logging_enabled = true;
312 }
313 
314 static void ga_log(const gchar *domain, GLogLevelFlags level,
315                    const gchar *msg, gpointer opaque)
316 {
317     GAState *s = opaque;
318     GTimeVal time;
319     const char *level_str = ga_log_level_str(level);
320 
321     if (!ga_logging_enabled(s)) {
322         return;
323     }
324 
325     level &= G_LOG_LEVEL_MASK;
326 #ifndef _WIN32
327     if (g_strcmp0(domain, "syslog") == 0) {
328         syslog(LOG_INFO, "%s: %s", level_str, msg);
329     } else if (level & s->log_level) {
330 #else
331     if (level & s->log_level) {
332 #endif
333         g_get_current_time(&time);
334         fprintf(s->log_file,
335                 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, 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);
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     const char *buf;
531     QString *payload_qstr, *response_qstr;
532     GIOStatus status;
533 
534     g_assert(rsp && s->channel);
535 
536     payload_qstr = qobject_to_json(QOBJECT(rsp));
537     if (!payload_qstr) {
538         return -EINVAL;
539     }
540 
541     if (s->delimit_response) {
542         s->delimit_response = false;
543         response_qstr = qstring_new();
544         qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
545         qstring_append(response_qstr, qstring_get_str(payload_qstr));
546         qobject_unref(payload_qstr);
547     } else {
548         response_qstr = payload_qstr;
549     }
550 
551     qstring_append_chr(response_qstr, '\n');
552     buf = qstring_get_str(response_qstr);
553     status = ga_channel_write_all(s->channel, buf, strlen(buf));
554     qobject_unref(response_qstr);
555     if (status != G_IO_STATUS_NORMAL) {
556         return -EIO;
557     }
558 
559     return 0;
560 }
561 
562 /* handle requests/control events coming in over the channel */
563 static void process_event(void *opaque, QObject *obj, Error *err)
564 {
565     GAState *s = opaque;
566     QDict *rsp;
567     int ret;
568 
569     g_debug("process_event: called");
570     assert(!obj != !err);
571     if (err) {
572         rsp = qmp_error_response(err);
573         goto end;
574     }
575 
576     g_debug("processing command");
577     rsp = qmp_dispatch(&ga_commands, obj, false);
578 
579 end:
580     ret = send_response(s, rsp);
581     if (ret < 0) {
582         g_warning("error sending error response: %s", strerror(-ret));
583     }
584     qobject_unref(rsp);
585     qobject_unref(obj);
586 }
587 
588 /* false return signals GAChannel to close the current client connection */
589 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
590 {
591     GAState *s = data;
592     gchar buf[QGA_READ_COUNT_DEFAULT+1];
593     gsize count;
594     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
595     switch (status) {
596     case G_IO_STATUS_ERROR:
597         g_warning("error reading channel");
598         stop_agent(s, false);
599         return false;
600     case G_IO_STATUS_NORMAL:
601         buf[count] = 0;
602         g_debug("read data, count: %d, data: %s", (int)count, buf);
603         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
604         break;
605     case G_IO_STATUS_EOF:
606         g_debug("received EOF");
607         if (!s->virtio) {
608             return false;
609         }
610         /* fall through */
611     case G_IO_STATUS_AGAIN:
612         /* virtio causes us to spin here when no process is attached to
613          * host-side chardev. sleep a bit to mitigate this
614          */
615         if (s->virtio) {
616             usleep(100*1000);
617         }
618         return true;
619     default:
620         g_warning("unknown channel read status, closing");
621         return false;
622     }
623     return true;
624 }
625 
626 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path,
627                              int listen_fd)
628 {
629     GAChannelMethod channel_method;
630 
631     if (strcmp(method, "virtio-serial") == 0) {
632         s->virtio = true; /* virtio requires special handling in some cases */
633         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
634     } else if (strcmp(method, "isa-serial") == 0) {
635         channel_method = GA_CHANNEL_ISA_SERIAL;
636     } else if (strcmp(method, "unix-listen") == 0) {
637         channel_method = GA_CHANNEL_UNIX_LISTEN;
638     } else if (strcmp(method, "vsock-listen") == 0) {
639         channel_method = GA_CHANNEL_VSOCK_LISTEN;
640     } else {
641         g_critical("unsupported channel method/type: %s", method);
642         return false;
643     }
644 
645     s->channel = ga_channel_new(channel_method, path, listen_fd,
646                                 channel_event_cb, s);
647     if (!s->channel) {
648         g_critical("failed to create guest agent channel");
649         return false;
650     }
651 
652     return true;
653 }
654 
655 #ifdef _WIN32
656 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data)
657 {
658     DWORD ret = NO_ERROR;
659     PDEV_BROADCAST_HDR broadcast_header = (PDEV_BROADCAST_HDR)data;
660 
661     if (broadcast_header->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE) {
662         switch (type) {
663             /* Device inserted */
664         case DBT_DEVICEARRIVAL:
665             /* Start QEMU-ga's service */
666             if (!SetEvent(ga_state->wakeup_event)) {
667                 ret = GetLastError();
668             }
669             break;
670             /* Device removed */
671         case DBT_DEVICEQUERYREMOVE:
672         case DBT_DEVICEREMOVEPENDING:
673         case DBT_DEVICEREMOVECOMPLETE:
674             /* Stop QEMU-ga's service */
675             if (!ResetEvent(ga_state->wakeup_event)) {
676                 ret = GetLastError();
677             }
678             break;
679         default:
680             ret = ERROR_CALL_NOT_IMPLEMENTED;
681         }
682     }
683     return ret;
684 }
685 
686 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
687                                   LPVOID ctx)
688 {
689     DWORD ret = NO_ERROR;
690     GAService *service = &ga_state->service;
691 
692     switch (ctrl)
693     {
694         case SERVICE_CONTROL_STOP:
695         case SERVICE_CONTROL_SHUTDOWN:
696             quit_handler(SIGTERM);
697             SetEvent(ga_state->wakeup_event);
698             service->status.dwCurrentState = SERVICE_STOP_PENDING;
699             SetServiceStatus(service->status_handle, &service->status);
700             break;
701         case SERVICE_CONTROL_DEVICEEVENT:
702             handle_serial_device_events(type, data);
703             break;
704 
705         default:
706             ret = ERROR_CALL_NOT_IMPLEMENTED;
707     }
708     return ret;
709 }
710 
711 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
712 {
713     GAService *service = &ga_state->service;
714 
715     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
716         service_ctrl_handler, NULL);
717 
718     if (service->status_handle == 0) {
719         g_critical("Failed to register extended requests function!\n");
720         return;
721     }
722 
723     service->status.dwServiceType = SERVICE_WIN32;
724     service->status.dwCurrentState = SERVICE_RUNNING;
725     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
726     service->status.dwWin32ExitCode = NO_ERROR;
727     service->status.dwServiceSpecificExitCode = NO_ERROR;
728     service->status.dwCheckPoint = 0;
729     service->status.dwWaitHint = 0;
730     DEV_BROADCAST_DEVICEINTERFACE notification_filter;
731     ZeroMemory(&notification_filter, sizeof(notification_filter));
732     notification_filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
733     notification_filter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
734     notification_filter.dbcc_classguid = GUID_VIOSERIAL_PORT;
735 
736     service->device_notification_handle =
737         RegisterDeviceNotification(service->status_handle,
738             &notification_filter, DEVICE_NOTIFY_SERVICE_HANDLE);
739     if (!service->device_notification_handle) {
740         g_critical("Failed to register device notification handle!\n");
741         return;
742     }
743     SetServiceStatus(service->status_handle, &service->status);
744 
745     run_agent(ga_state);
746 
747     UnregisterDeviceNotification(service->device_notification_handle);
748     service->status.dwCurrentState = SERVICE_STOPPED;
749     SetServiceStatus(service->status_handle, &service->status);
750 }
751 #endif
752 
753 static void set_persistent_state_defaults(GAPersistentState *pstate)
754 {
755     g_assert(pstate);
756     pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
757 }
758 
759 static void persistent_state_from_keyfile(GAPersistentState *pstate,
760                                           GKeyFile *keyfile)
761 {
762     g_assert(pstate);
763     g_assert(keyfile);
764     /* if any fields are missing, either because the file was tampered with
765      * by agents of chaos, or because the field wasn't present at the time the
766      * file was created, the best we can ever do is start over with the default
767      * values. so load them now, and ignore any errors in accessing key-value
768      * pairs
769      */
770     set_persistent_state_defaults(pstate);
771 
772     if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
773         pstate->fd_counter =
774             g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
775     }
776 }
777 
778 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
779                                         GKeyFile *keyfile)
780 {
781     g_assert(pstate);
782     g_assert(keyfile);
783 
784     g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
785 }
786 
787 static gboolean write_persistent_state(const GAPersistentState *pstate,
788                                        const gchar *path)
789 {
790     GKeyFile *keyfile = g_key_file_new();
791     GError *gerr = NULL;
792     gboolean ret = true;
793     gchar *data = NULL;
794     gsize data_len;
795 
796     g_assert(pstate);
797 
798     persistent_state_to_keyfile(pstate, keyfile);
799     data = g_key_file_to_data(keyfile, &data_len, &gerr);
800     if (gerr) {
801         g_critical("failed to convert persistent state to string: %s",
802                    gerr->message);
803         ret = false;
804         goto out;
805     }
806 
807     g_file_set_contents(path, data, data_len, &gerr);
808     if (gerr) {
809         g_critical("failed to write persistent state to %s: %s",
810                     path, gerr->message);
811         ret = false;
812         goto out;
813     }
814 
815 out:
816     if (gerr) {
817         g_error_free(gerr);
818     }
819     if (keyfile) {
820         g_key_file_free(keyfile);
821     }
822     g_free(data);
823     return ret;
824 }
825 
826 static gboolean read_persistent_state(GAPersistentState *pstate,
827                                       const gchar *path, gboolean frozen)
828 {
829     GKeyFile *keyfile = NULL;
830     GError *gerr = NULL;
831     struct stat st;
832     gboolean ret = true;
833 
834     g_assert(pstate);
835 
836     if (stat(path, &st) == -1) {
837         /* it's okay if state file doesn't exist, but any other error
838          * indicates a permissions issue or some other misconfiguration
839          * that we likely won't be able to recover from.
840          */
841         if (errno != ENOENT) {
842             g_critical("unable to access state file at path %s: %s",
843                        path, strerror(errno));
844             ret = false;
845             goto out;
846         }
847 
848         /* file doesn't exist. initialize state to default values and
849          * attempt to save now. (we could wait till later when we have
850          * modified state we need to commit, but if there's a problem,
851          * such as a missing parent directory, we want to catch it now)
852          *
853          * there is a potential scenario where someone either managed to
854          * update the agent from a version that didn't use a key store
855          * while qemu-ga thought the filesystem was frozen, or
856          * deleted the key store prior to issuing a fsfreeze, prior
857          * to restarting the agent. in this case we go ahead and defer
858          * initial creation till we actually have modified state to
859          * write, otherwise fail to recover from freeze.
860          */
861         set_persistent_state_defaults(pstate);
862         if (!frozen) {
863             ret = write_persistent_state(pstate, path);
864             if (!ret) {
865                 g_critical("unable to create state file at path %s", path);
866                 ret = false;
867                 goto out;
868             }
869         }
870         ret = true;
871         goto out;
872     }
873 
874     keyfile = g_key_file_new();
875     g_key_file_load_from_file(keyfile, path, 0, &gerr);
876     if (gerr) {
877         g_critical("error loading persistent state from path: %s, %s",
878                    path, gerr->message);
879         ret = false;
880         goto out;
881     }
882 
883     persistent_state_from_keyfile(pstate, keyfile);
884 
885 out:
886     if (keyfile) {
887         g_key_file_free(keyfile);
888     }
889     if (gerr) {
890         g_error_free(gerr);
891     }
892 
893     return ret;
894 }
895 
896 int64_t ga_get_fd_handle(GAState *s, Error **errp)
897 {
898     int64_t handle;
899 
900     g_assert(s->pstate_filepath);
901     /* we blacklist commands and avoid operations that potentially require
902      * writing to disk when we're in a frozen state. this includes opening
903      * new files, so we should never get here in that situation
904      */
905     g_assert(!ga_is_frozen(s));
906 
907     handle = s->pstate.fd_counter++;
908 
909     /* This should never happen on a reasonable timeframe, as guest-file-open
910      * would have to be issued 2^63 times */
911     if (s->pstate.fd_counter == INT64_MAX) {
912         abort();
913     }
914 
915     if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
916         error_setg(errp, "failed to commit persistent state to disk");
917         return -1;
918     }
919 
920     return handle;
921 }
922 
923 static void ga_print_cmd(const QmpCommand *cmd, void *opaque)
924 {
925     printf("%s\n", qmp_command_name(cmd));
926 }
927 
928 static GList *split_list(const gchar *str, const gchar *delim)
929 {
930     GList *list = NULL;
931     int i;
932     gchar **strv;
933 
934     strv = g_strsplit(str, delim, -1);
935     for (i = 0; strv[i]; i++) {
936         list = g_list_prepend(list, strv[i]);
937     }
938     g_free(strv);
939 
940     return list;
941 }
942 
943 struct GAConfig {
944     char *channel_path;
945     char *method;
946     char *log_filepath;
947     char *pid_filepath;
948 #ifdef CONFIG_FSFREEZE
949     char *fsfreeze_hook;
950 #endif
951     char *state_dir;
952 #ifdef _WIN32
953     const char *service;
954 #endif
955     gchar *bliststr; /* blacklist may point to this string */
956     GList *blacklist;
957     int daemonize;
958     GLogLevelFlags log_level;
959     int dumpconf;
960     bool retry_path;
961 };
962 
963 static void config_load(GAConfig *config)
964 {
965     GError *gerr = NULL;
966     GKeyFile *keyfile;
967     const char *conf = g_getenv("QGA_CONF") ?: QGA_CONF_DEFAULT;
968 
969     /* read system config */
970     keyfile = g_key_file_new();
971     if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
972         goto end;
973     }
974     if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
975         config->daemonize =
976             g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
977     }
978     if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
979         config->method =
980             g_key_file_get_string(keyfile, "general", "method", &gerr);
981     }
982     if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
983         config->channel_path =
984             g_key_file_get_string(keyfile, "general", "path", &gerr);
985     }
986     if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
987         config->log_filepath =
988             g_key_file_get_string(keyfile, "general", "logfile", &gerr);
989     }
990     if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
991         config->pid_filepath =
992             g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
993     }
994 #ifdef CONFIG_FSFREEZE
995     if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
996         config->fsfreeze_hook =
997             g_key_file_get_string(keyfile,
998                                   "general", "fsfreeze-hook", &gerr);
999     }
1000 #endif
1001     if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
1002         config->state_dir =
1003             g_key_file_get_string(keyfile, "general", "statedir", &gerr);
1004     }
1005     if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
1006         g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
1007         /* enable all log levels */
1008         config->log_level = G_LOG_LEVEL_MASK;
1009     }
1010     if (g_key_file_has_key(keyfile, "general", "retry-path", NULL)) {
1011         config->retry_path =
1012             g_key_file_get_boolean(keyfile, "general", "retry-path", &gerr);
1013     }
1014     if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
1015         config->bliststr =
1016             g_key_file_get_string(keyfile, "general", "blacklist", &gerr);
1017         config->blacklist = g_list_concat(config->blacklist,
1018                                           split_list(config->bliststr, ","));
1019     }
1020 
1021 end:
1022     g_key_file_free(keyfile);
1023     if (gerr &&
1024         !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
1025         g_critical("error loading configuration from path: %s, %s",
1026                    QGA_CONF_DEFAULT, gerr->message);
1027         exit(EXIT_FAILURE);
1028     }
1029     g_clear_error(&gerr);
1030 }
1031 
1032 static gchar *list_join(GList *list, const gchar separator)
1033 {
1034     GString *str = g_string_new("");
1035 
1036     while (list) {
1037         str = g_string_append(str, (gchar *)list->data);
1038         list = g_list_next(list);
1039         if (list) {
1040             str = g_string_append_c(str, separator);
1041         }
1042     }
1043 
1044     return g_string_free(str, FALSE);
1045 }
1046 
1047 static void config_dump(GAConfig *config)
1048 {
1049     GError *error = NULL;
1050     GKeyFile *keyfile;
1051     gchar *tmp;
1052 
1053     keyfile = g_key_file_new();
1054     g_assert(keyfile);
1055 
1056     g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1057     g_key_file_set_string(keyfile, "general", "method", config->method);
1058     if (config->channel_path) {
1059         g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1060     }
1061     if (config->log_filepath) {
1062         g_key_file_set_string(keyfile, "general", "logfile",
1063                               config->log_filepath);
1064     }
1065     g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1066 #ifdef CONFIG_FSFREEZE
1067     if (config->fsfreeze_hook) {
1068         g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1069                               config->fsfreeze_hook);
1070     }
1071 #endif
1072     g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1073     g_key_file_set_boolean(keyfile, "general", "verbose",
1074                            config->log_level == G_LOG_LEVEL_MASK);
1075     g_key_file_set_boolean(keyfile, "general", "retry-path",
1076                            config->retry_path);
1077     tmp = list_join(config->blacklist, ',');
1078     g_key_file_set_string(keyfile, "general", "blacklist", tmp);
1079     g_free(tmp);
1080 
1081     tmp = g_key_file_to_data(keyfile, NULL, &error);
1082     if (error) {
1083         g_critical("Failed to dump keyfile: %s", error->message);
1084         g_clear_error(&error);
1085     } else {
1086         printf("%s", tmp);
1087     }
1088 
1089     g_free(tmp);
1090     g_key_file_free(keyfile);
1091 }
1092 
1093 static void config_parse(GAConfig *config, int argc, char **argv)
1094 {
1095     const char *sopt = "hVvdm:p:l:f:F::b:s:t:Dr";
1096     int opt_ind = 0, ch;
1097     const struct option lopt[] = {
1098         { "help", 0, NULL, 'h' },
1099         { "version", 0, NULL, 'V' },
1100         { "dump-conf", 0, NULL, 'D' },
1101         { "logfile", 1, NULL, 'l' },
1102         { "pidfile", 1, NULL, 'f' },
1103 #ifdef CONFIG_FSFREEZE
1104         { "fsfreeze-hook", 2, NULL, 'F' },
1105 #endif
1106         { "verbose", 0, NULL, 'v' },
1107         { "method", 1, NULL, 'm' },
1108         { "path", 1, NULL, 'p' },
1109         { "daemonize", 0, NULL, 'd' },
1110         { "blacklist", 1, NULL, 'b' },
1111 #ifdef _WIN32
1112         { "service", 1, NULL, 's' },
1113 #endif
1114         { "statedir", 1, NULL, 't' },
1115         { "retry-path", 0, NULL, 'r' },
1116         { NULL, 0, NULL, 0 }
1117     };
1118 
1119     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1120         switch (ch) {
1121         case 'm':
1122             g_free(config->method);
1123             config->method = g_strdup(optarg);
1124             break;
1125         case 'p':
1126             g_free(config->channel_path);
1127             config->channel_path = g_strdup(optarg);
1128             break;
1129         case 'l':
1130             g_free(config->log_filepath);
1131             config->log_filepath = g_strdup(optarg);
1132             break;
1133         case 'f':
1134             g_free(config->pid_filepath);
1135             config->pid_filepath = g_strdup(optarg);
1136             break;
1137 #ifdef CONFIG_FSFREEZE
1138         case 'F':
1139             g_free(config->fsfreeze_hook);
1140             config->fsfreeze_hook = g_strdup(optarg ?: QGA_FSFREEZE_HOOK_DEFAULT);
1141             break;
1142 #endif
1143         case 't':
1144             g_free(config->state_dir);
1145             config->state_dir = g_strdup(optarg);
1146             break;
1147         case 'v':
1148             /* enable all log levels */
1149             config->log_level = G_LOG_LEVEL_MASK;
1150             break;
1151         case 'V':
1152             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1153             exit(EXIT_SUCCESS);
1154         case 'd':
1155             config->daemonize = 1;
1156             break;
1157         case 'D':
1158             config->dumpconf = 1;
1159             break;
1160         case 'r':
1161             config->retry_path = true;
1162             break;
1163         case 'b': {
1164             if (is_help_option(optarg)) {
1165                 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1166                 exit(EXIT_SUCCESS);
1167             }
1168             config->blacklist = g_list_concat(config->blacklist,
1169                                              split_list(optarg, ","));
1170             break;
1171         }
1172 #ifdef _WIN32
1173         case 's':
1174             config->service = optarg;
1175             if (strcmp(config->service, "install") == 0) {
1176                 if (ga_install_vss_provider()) {
1177                     exit(EXIT_FAILURE);
1178                 }
1179                 if (ga_install_service(config->channel_path,
1180                                        config->log_filepath, config->state_dir)) {
1181                     exit(EXIT_FAILURE);
1182                 }
1183                 exit(EXIT_SUCCESS);
1184             } else if (strcmp(config->service, "uninstall") == 0) {
1185                 ga_uninstall_vss_provider();
1186                 exit(ga_uninstall_service());
1187             } else if (strcmp(config->service, "vss-install") == 0) {
1188                 if (ga_install_vss_provider()) {
1189                     exit(EXIT_FAILURE);
1190                 }
1191                 exit(EXIT_SUCCESS);
1192             } else if (strcmp(config->service, "vss-uninstall") == 0) {
1193                 ga_uninstall_vss_provider();
1194                 exit(EXIT_SUCCESS);
1195             } else {
1196                 printf("Unknown service command.\n");
1197                 exit(EXIT_FAILURE);
1198             }
1199             break;
1200 #endif
1201         case 'h':
1202             usage(argv[0]);
1203             exit(EXIT_SUCCESS);
1204         case '?':
1205             g_print("Unknown option, try '%s --help' for more information.\n",
1206                     argv[0]);
1207             exit(EXIT_FAILURE);
1208         }
1209     }
1210 }
1211 
1212 static void config_free(GAConfig *config)
1213 {
1214     g_free(config->method);
1215     g_free(config->log_filepath);
1216     g_free(config->pid_filepath);
1217     g_free(config->state_dir);
1218     g_free(config->channel_path);
1219     g_free(config->bliststr);
1220 #ifdef CONFIG_FSFREEZE
1221     g_free(config->fsfreeze_hook);
1222 #endif
1223     g_list_free_full(config->blacklist, g_free);
1224     g_free(config);
1225 }
1226 
1227 static bool check_is_frozen(GAState *s)
1228 {
1229 #ifndef _WIN32
1230     /* check if a previous instance of qemu-ga exited with filesystems' state
1231      * marked as frozen. this could be a stale value (a non-qemu-ga process
1232      * or reboot may have since unfrozen them), but better to require an
1233      * uneeded unfreeze than to risk hanging on start-up
1234      */
1235     struct stat st;
1236     if (stat(s->state_filepath_isfrozen, &st) == -1) {
1237         /* it's okay if the file doesn't exist, but if we can't access for
1238          * some other reason, such as permissions, there's a configuration
1239          * that needs to be addressed. so just bail now before we get into
1240          * more trouble later
1241          */
1242         if (errno != ENOENT) {
1243             g_critical("unable to access state file at path %s: %s",
1244                        s->state_filepath_isfrozen, strerror(errno));
1245             return EXIT_FAILURE;
1246         }
1247     } else {
1248         g_warning("previous instance appears to have exited with frozen"
1249                   " filesystems. deferring logging/pidfile creation and"
1250                   " disabling non-fsfreeze-safe commands until"
1251                   " guest-fsfreeze-thaw is issued, or filesystems are"
1252                   " manually unfrozen and the file %s is removed",
1253                   s->state_filepath_isfrozen);
1254         return true;
1255     }
1256 #endif
1257     return false;
1258 }
1259 
1260 static GAState *initialize_agent(GAConfig *config, int socket_activation)
1261 {
1262     GAState *s = g_new0(GAState, 1);
1263 
1264     g_assert(ga_state == NULL);
1265 
1266     s->log_level = config->log_level;
1267     s->log_file = stderr;
1268 #ifdef CONFIG_FSFREEZE
1269     s->fsfreeze_hook = config->fsfreeze_hook;
1270 #endif
1271     s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1272     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1273                                                  config->state_dir);
1274     s->frozen = check_is_frozen(s);
1275 
1276     g_log_set_default_handler(ga_log, s);
1277     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1278     ga_enable_logging(s);
1279 
1280 #ifdef _WIN32
1281     /* On win32 the state directory is application specific (be it the default
1282      * or a user override). We got past the command line parsing; let's create
1283      * the directory (with any intermediate directories). If we run into an
1284      * error later on, we won't try to clean up the directory, it is considered
1285      * persistent.
1286      */
1287     if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1288         g_critical("unable to create (an ancestor of) the state directory"
1289                    " '%s': %s", config->state_dir, strerror(errno));
1290         return NULL;
1291     }
1292 #endif
1293 
1294     if (ga_is_frozen(s)) {
1295         if (config->daemonize) {
1296             /* delay opening/locking of pidfile till filesystems are unfrozen */
1297             s->deferred_options.pid_filepath = config->pid_filepath;
1298             become_daemon(NULL);
1299         }
1300         if (config->log_filepath) {
1301             /* delay opening the log file till filesystems are unfrozen */
1302             s->deferred_options.log_filepath = config->log_filepath;
1303         }
1304         ga_disable_logging(s);
1305         qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
1306     } else {
1307         if (config->daemonize) {
1308             become_daemon(config->pid_filepath);
1309         }
1310         if (config->log_filepath) {
1311             FILE *log_file = ga_open_logfile(config->log_filepath);
1312             if (!log_file) {
1313                 g_critical("unable to open specified log file: %s",
1314                            strerror(errno));
1315                 return NULL;
1316             }
1317             s->log_file = log_file;
1318         }
1319     }
1320 
1321     /* load persistent state from disk */
1322     if (!read_persistent_state(&s->pstate,
1323                                s->pstate_filepath,
1324                                ga_is_frozen(s))) {
1325         g_critical("failed to load persistent state");
1326         return NULL;
1327     }
1328 
1329     config->blacklist = ga_command_blacklist_init(config->blacklist);
1330     if (config->blacklist) {
1331         GList *l = config->blacklist;
1332         s->blacklist = config->blacklist;
1333         do {
1334             g_debug("disabling command: %s", (char *)l->data);
1335             qmp_disable_command(&ga_commands, l->data);
1336             l = g_list_next(l);
1337         } while (l);
1338     }
1339     s->command_state = ga_command_state_new();
1340     ga_command_state_init(s, s->command_state);
1341     ga_command_state_init_all(s->command_state);
1342     json_message_parser_init(&s->parser, process_event, s, NULL);
1343 
1344 #ifndef _WIN32
1345     if (!register_signal_handlers()) {
1346         g_critical("failed to register signal handlers");
1347         return NULL;
1348     }
1349 #endif
1350 
1351     s->main_loop = g_main_loop_new(NULL, false);
1352 
1353     s->config = config;
1354     s->socket_activation = socket_activation;
1355 
1356 #ifdef _WIN32
1357     s->wakeup_event = CreateEvent(NULL, TRUE, FALSE, TEXT("WakeUp"));
1358     if (s->wakeup_event == NULL) {
1359         g_critical("CreateEvent failed");
1360         return NULL;
1361     }
1362 #endif
1363 
1364     ga_state = s;
1365     return s;
1366 }
1367 
1368 static void cleanup_agent(GAState *s)
1369 {
1370 #ifdef _WIN32
1371     CloseHandle(s->wakeup_event);
1372 #endif
1373     if (s->command_state) {
1374         ga_command_state_cleanup_all(s->command_state);
1375         ga_command_state_free(s->command_state);
1376         json_message_parser_destroy(&s->parser);
1377     }
1378     g_free(s->pstate_filepath);
1379     g_free(s->state_filepath_isfrozen);
1380     if (s->main_loop) {
1381         g_main_loop_unref(s->main_loop);
1382     }
1383     g_free(s);
1384     ga_state = NULL;
1385 }
1386 
1387 static int run_agent_once(GAState *s)
1388 {
1389     if (!channel_init(s, s->config->method, s->config->channel_path,
1390                       s->socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
1391         g_critical("failed to initialize guest agent channel");
1392         return EXIT_FAILURE;
1393     }
1394 
1395     g_main_loop_run(ga_state->main_loop);
1396 
1397     if (s->channel) {
1398         ga_channel_free(s->channel);
1399     }
1400 
1401     return EXIT_SUCCESS;
1402 }
1403 
1404 static void wait_for_channel_availability(GAState *s)
1405 {
1406     g_warning("waiting for channel path...");
1407 #ifndef _WIN32
1408     sleep(QGA_RETRY_INTERVAL);
1409 #else
1410     DWORD dwWaitResult;
1411 
1412     dwWaitResult = WaitForSingleObject(s->wakeup_event, INFINITE);
1413 
1414     switch (dwWaitResult) {
1415     case WAIT_OBJECT_0:
1416         break;
1417     case WAIT_TIMEOUT:
1418         break;
1419     default:
1420         g_critical("WaitForSingleObject failed");
1421     }
1422 #endif
1423 }
1424 
1425 static int run_agent(GAState *s)
1426 {
1427     int ret = EXIT_SUCCESS;
1428 
1429     s->force_exit = false;
1430 
1431     do {
1432         ret = run_agent_once(s);
1433         if (s->config->retry_path && !s->force_exit) {
1434             g_warning("agent stopped unexpectedly, restarting...");
1435             wait_for_channel_availability(s);
1436         }
1437     } while (s->config->retry_path && !s->force_exit);
1438 
1439     return ret;
1440 }
1441 
1442 static void stop_agent(GAState *s, bool requested)
1443 {
1444     if (!s->force_exit) {
1445         s->force_exit = requested;
1446     }
1447 
1448     if (g_main_loop_is_running(s->main_loop)) {
1449         g_main_loop_quit(s->main_loop);
1450     }
1451 }
1452 
1453 int main(int argc, char **argv)
1454 {
1455     int ret = EXIT_SUCCESS;
1456     GAState *s;
1457     GAConfig *config = g_new0(GAConfig, 1);
1458     int socket_activation;
1459 
1460     config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1461 
1462     qga_qmp_init_marshal(&ga_commands);
1463 
1464     init_dfl_pathnames();
1465     config_load(config);
1466     config_parse(config, argc, argv);
1467 
1468     if (config->pid_filepath == NULL) {
1469         config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1470     }
1471 
1472     if (config->state_dir == NULL) {
1473         config->state_dir = g_strdup(dfl_pathnames.state_dir);
1474     }
1475 
1476     if (config->method == NULL) {
1477         config->method = g_strdup("virtio-serial");
1478     }
1479 
1480     socket_activation = check_socket_activation();
1481     if (socket_activation > 1) {
1482         g_critical("qemu-ga only supports listening on one socket");
1483         ret = EXIT_FAILURE;
1484         goto end;
1485     }
1486     if (socket_activation) {
1487         SocketAddress *addr;
1488 
1489         g_free(config->method);
1490         g_free(config->channel_path);
1491         config->method = NULL;
1492         config->channel_path = NULL;
1493 
1494         addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL);
1495         if (addr) {
1496             if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
1497                 config->method = g_strdup("unix-listen");
1498             } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
1499                 config->method = g_strdup("vsock-listen");
1500             }
1501 
1502             qapi_free_SocketAddress(addr);
1503         }
1504 
1505         if (!config->method) {
1506             g_critical("unsupported listen fd type");
1507             ret = EXIT_FAILURE;
1508             goto end;
1509         }
1510     } else if (config->channel_path == NULL) {
1511         if (strcmp(config->method, "virtio-serial") == 0) {
1512             /* try the default path for the virtio-serial port */
1513             config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1514         } else if (strcmp(config->method, "isa-serial") == 0) {
1515             /* try the default path for the serial port - COM1 */
1516             config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1517         } else {
1518             g_critical("must specify a path for this channel");
1519             ret = EXIT_FAILURE;
1520             goto end;
1521         }
1522     }
1523 
1524     if (config->dumpconf) {
1525         config_dump(config);
1526         goto end;
1527     }
1528 
1529     s = initialize_agent(config, socket_activation);
1530     if (!s) {
1531         g_critical("error initializing guest agent");
1532         goto end;
1533     }
1534 
1535 #ifdef _WIN32
1536     if (config->daemonize) {
1537         SERVICE_TABLE_ENTRY service_table[] = {
1538             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1539         StartServiceCtrlDispatcher(service_table);
1540     } else {
1541         ret = run_agent(s);
1542     }
1543 #else
1544     ret = run_agent(s);
1545 #endif
1546 
1547     cleanup_agent(s);
1548 
1549 end:
1550     if (config->daemonize) {
1551         unlink(config->pid_filepath);
1552     }
1553 
1554     config_free(config);
1555 
1556     return ret;
1557 }
1558