summaryrefslogtreecommitdiff
blob: 1b00c2f44a575e5fd1e5d87a39b458e4603fccfb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
/*
 * QEMU Guest Agent
 *
 * Copyright IBM Corp. 2011
 *
 * Authors:
 *  Adam Litke        <aglitke@linux.vnet.ibm.com>
 *  Michael Roth      <mdroth@linux.vnet.ibm.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */
#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <glib.h>
#include <getopt.h>
#ifndef _WIN32
#include <syslog.h>
#include <sys/wait.h>
#include <sys/stat.h>
#endif
#include "json-streamer.h"
#include "json-parser.h"
#include "qint.h"
#include "qjson.h"
#include "qga/guest-agent-core.h"
#include "module.h"
#include "signal.h"
#include "qerror.h"
#include "error_int.h"
#include "qapi/qmp-core.h"
#include "qga/channel.h"
#ifdef _WIN32
#include "qga/service-win32.h"
#include <windows.h>
#endif

#ifndef _WIN32
#define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
#else
#define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
#endif
#define QGA_PIDFILE_DEFAULT "/var/run/qemu-ga.pid"
#define QGA_STATEDIR_DEFAULT "/tmp"
#define QGA_SENTINEL_BYTE 0xFF

struct GAState {
    JSONMessageParser parser;
    GMainLoop *main_loop;
    GAChannel *channel;
    bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
    GACommandState *command_state;
    GLogLevelFlags log_level;
    FILE *log_file;
    bool logging_enabled;
#ifdef _WIN32
    GAService service;
#endif
    bool delimit_response;
    bool frozen;
    GList *blacklist;
    const char *state_filepath_isfrozen;
    struct {
        const char *log_filepath;
        const char *pid_filepath;
    } deferred_options;
};

struct GAState *ga_state;

/* commands that are safe to issue while filesystems are frozen */
static const char *ga_freeze_whitelist[] = {
    "guest-ping",
    "guest-info",
    "guest-sync",
    "guest-fsfreeze-status",
    "guest-fsfreeze-thaw",
    NULL
};

#ifdef _WIN32
DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
                                  LPVOID ctx);
VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
#endif

static void quit_handler(int sig)
{
    /* if we're frozen, don't exit unless we're absolutely forced to,
     * because it's basically impossible for graceful exit to complete
     * unless all log/pid files are on unfreezable filesystems. there's
     * also a very likely chance killing the agent before unfreezing
     * the filesystems is a mistake (or will be viewed as one later).
     */
    if (ga_is_frozen(ga_state)) {
        return;
    }
    g_debug("received signal num %d, quitting", sig);

    if (g_main_loop_is_running(ga_state->main_loop)) {
        g_main_loop_quit(ga_state->main_loop);
    }
}

#ifndef _WIN32
static gboolean register_signal_handlers(void)
{
    struct sigaction sigact;
    int ret;

    memset(&sigact, 0, sizeof(struct sigaction));
    sigact.sa_handler = quit_handler;

    ret = sigaction(SIGINT, &sigact, NULL);
    if (ret == -1) {
        g_error("error configuring signal handler: %s", strerror(errno));
        return false;
    }
    ret = sigaction(SIGTERM, &sigact, NULL);
    if (ret == -1) {
        g_error("error configuring signal handler: %s", strerror(errno));
        return false;
    }

    return true;
}

/* TODO: use this in place of all post-fork() fclose(std*) callers */
void reopen_fd_to_null(int fd)
{
    int nullfd;

    nullfd = open("/dev/null", O_RDWR);
    if (nullfd < 0) {
        return;
    }

    dup2(nullfd, fd);

    if (nullfd != fd) {
        close(nullfd);
    }
}
#endif

static void usage(const char *cmd)
{
    printf(
"Usage: %s [-m <method> -p <path>] [<options>]\n"
"QEMU Guest Agent %s\n"
"\n"
"  -m, --method      transport method: one of unix-listen, virtio-serial, or\n"
"                    isa-serial (virtio-serial is the default)\n"
"  -p, --path        device/socket path (the default for virtio-serial is:\n"
"                    %s)\n"
"  -l, --logfile     set logfile path, logs to stderr by default\n"
"  -f, --pidfile     specify pidfile (default is %s)\n"
"  -t, --statedir    specify dir to store state information (absolute paths\n"
"                    only, default is %s)\n"
"  -v, --verbose     log extra debugging information\n"
"  -V, --version     print version information and exit\n"
"  -d, --daemonize   become a daemon\n"
#ifdef _WIN32
"  -s, --service     service commands: install, uninstall\n"
#endif
"  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\"\n"
"                    to list available RPCs)\n"
"  -h, --help        display this help and exit\n"
"\n"
"Report bugs to <mdroth@linux.vnet.ibm.com>\n"
    , cmd, QEMU_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT,
    QGA_STATEDIR_DEFAULT);
}

static const char *ga_log_level_str(GLogLevelFlags level)
{
    switch (level & G_LOG_LEVEL_MASK) {
        case G_LOG_LEVEL_ERROR:
            return "error";
        case G_LOG_LEVEL_CRITICAL:
            return "critical";
        case G_LOG_LEVEL_WARNING:
            return "warning";
        case G_LOG_LEVEL_MESSAGE:
            return "message";
        case G_LOG_LEVEL_INFO:
            return "info";
        case G_LOG_LEVEL_DEBUG:
            return "debug";
        default:
            return "user";
    }
}

bool ga_logging_enabled(GAState *s)
{
    return s->logging_enabled;
}

void ga_disable_logging(GAState *s)
{
    s->logging_enabled = false;
}

void ga_enable_logging(GAState *s)
{
    s->logging_enabled = true;
}

static void ga_log(const gchar *domain, GLogLevelFlags level,
                   const gchar *msg, gpointer opaque)
{
    GAState *s = opaque;
    GTimeVal time;
    const char *level_str = ga_log_level_str(level);

    if (!ga_logging_enabled(s)) {
        return;
    }

    level &= G_LOG_LEVEL_MASK;
#ifndef _WIN32
    if (domain && strcmp(domain, "syslog") == 0) {
        syslog(LOG_INFO, "%s: %s", level_str, msg);
    } else if (level & s->log_level) {
#else
    if (level & s->log_level) {
#endif
        g_get_current_time(&time);
        fprintf(s->log_file,
                "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
        fflush(s->log_file);
    }
}

void ga_set_response_delimited(GAState *s)
{
    s->delimit_response = true;
}

#ifndef _WIN32
static bool ga_open_pidfile(const char *pidfile)
{
    int pidfd;
    char pidstr[32];

    pidfd = open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
    if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) {
        g_critical("Cannot lock pid file, %s", strerror(errno));
        if (pidfd != -1) {
            close(pidfd);
        }
        return false;
    }

    if (ftruncate(pidfd, 0) || lseek(pidfd, 0, SEEK_SET)) {
        g_critical("Failed to truncate pid file");
        goto fail;
    }
    sprintf(pidstr, "%d", getpid());
    if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
        g_critical("Failed to write pid file");
        goto fail;
    }

    return true;

fail:
    unlink(pidfile);
    return false;
}
#else /* _WIN32 */
static bool ga_open_pidfile(const char *pidfile)
{
    return true;
}
#endif

static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
{
    return strcmp(str1, str2);
}

/* disable commands that aren't safe for fsfreeze */
static void ga_disable_non_whitelisted(void)
{
    char **list_head, **list;
    bool whitelisted;
    int i;

    list_head = list = qmp_get_command_list();
    while (*list != NULL) {
        whitelisted = false;
        i = 0;
        while (ga_freeze_whitelist[i] != NULL) {
            if (strcmp(*list, ga_freeze_whitelist[i]) == 0) {
                whitelisted = true;
            }
            i++;
        }
        if (!whitelisted) {
            g_debug("disabling command: %s", *list);
            qmp_disable_command(*list);
        }
        g_free(*list);
        list++;
    }
    g_free(list_head);
}

/* [re-]enable all commands, except those explicitly blacklisted by user */
static void ga_enable_non_blacklisted(GList *blacklist)
{
    char **list_head, **list;

    list_head = list = qmp_get_command_list();
    while (*list != NULL) {
        if (g_list_find_custom(blacklist, *list, ga_strcmp) == NULL &&
            !qmp_command_is_enabled(*list)) {
            g_debug("enabling command: %s", *list);
            qmp_enable_command(*list);
        }
        g_free(*list);
        list++;
    }
    g_free(list_head);
}

static bool ga_create_file(const char *path)
{
    int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
    if (fd == -1) {
        g_warning("unable to open/create file %s: %s", path, strerror(errno));
        return false;
    }
    close(fd);
    return true;
}

static bool ga_delete_file(const char *path)
{
    int ret = unlink(path);
    if (ret == -1) {
        g_warning("unable to delete file: %s: %s", path, strerror(errno));
        return false;
    }

    return true;
}

bool ga_is_frozen(GAState *s)
{
    return s->frozen;
}

void ga_set_frozen(GAState *s)
{
    if (ga_is_frozen(s)) {
        return;
    }
    /* disable all non-whitelisted (for frozen state) commands */
    ga_disable_non_whitelisted();
    g_warning("disabling logging due to filesystem freeze");
    ga_disable_logging(s);
    s->frozen = true;
    if (!ga_create_file(s->state_filepath_isfrozen)) {
        g_warning("unable to create %s, fsfreeze may not function properly",
                  s->state_filepath_isfrozen);
    }
}

void ga_unset_frozen(GAState *s)
{
    if (!ga_is_frozen(s)) {
        return;
    }

    /* if we delayed creation/opening of pid/log files due to being
     * in a frozen state at start up, do it now
     */
    if (s->deferred_options.log_filepath) {
        s->log_file = fopen(s->deferred_options.log_filepath, "a");
        if (!s->log_file) {
            s->log_file = stderr;
        }
        s->deferred_options.log_filepath = NULL;
    }
    ga_enable_logging(s);
    g_warning("logging re-enabled due to filesystem unfreeze");
    if (s->deferred_options.pid_filepath) {
        if (!ga_open_pidfile(s->deferred_options.pid_filepath)) {
            g_warning("failed to create/open pid file");
        }
        s->deferred_options.pid_filepath = NULL;
    }

    /* enable all disabled, non-blacklisted commands */
    ga_enable_non_blacklisted(s->blacklist);
    s->frozen = false;
    if (!ga_delete_file(s->state_filepath_isfrozen)) {
        g_warning("unable to delete %s, fsfreeze may not function properly",
                  s->state_filepath_isfrozen);
    }
}

static void become_daemon(const char *pidfile)
{
#ifndef _WIN32
    pid_t pid, sid;

    pid = fork();
    if (pid < 0) {
        exit(EXIT_FAILURE);
    }
    if (pid > 0) {
        exit(EXIT_SUCCESS);
    }

    if (pidfile) {
        if (!ga_open_pidfile(pidfile)) {
            g_critical("failed to create pidfile");
            exit(EXIT_FAILURE);
        }
    }

    umask(0);
    sid = setsid();
    if (sid < 0) {
        goto fail;
    }
    if ((chdir("/")) < 0) {
        goto fail;
    }

    reopen_fd_to_null(STDIN_FILENO);
    reopen_fd_to_null(STDOUT_FILENO);
    reopen_fd_to_null(STDERR_FILENO);
    return;

fail:
    if (pidfile) {
        unlink(pidfile);
    }
    g_critical("failed to daemonize");
    exit(EXIT_FAILURE);
#endif
}

static int send_response(GAState *s, QObject *payload)
{
    const char *buf;
    QString *payload_qstr, *response_qstr;
    GIOStatus status;

    g_assert(payload && s->channel);

    payload_qstr = qobject_to_json(payload);
    if (!payload_qstr) {
        return -EINVAL;
    }

    if (s->delimit_response) {
        s->delimit_response = false;
        response_qstr = qstring_new();
        qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
        qstring_append(response_qstr, qstring_get_str(payload_qstr));
        QDECREF(payload_qstr);
    } else {
        response_qstr = payload_qstr;
    }

    qstring_append_chr(response_qstr, '\n');
    buf = qstring_get_str(response_qstr);
    status = ga_channel_write_all(s->channel, buf, strlen(buf));
    QDECREF(response_qstr);
    if (status != G_IO_STATUS_NORMAL) {
        return -EIO;
    }

    return 0;
}

static void process_command(GAState *s, QDict *req)
{
    QObject *rsp = NULL;
    int ret;

    g_assert(req);
    g_debug("processing command");
    rsp = qmp_dispatch(QOBJECT(req));
    if (rsp) {
        ret = send_response(s, rsp);
        if (ret) {
            g_warning("error sending response: %s", strerror(ret));
        }
        qobject_decref(rsp);
    }
}

/* handle requests/control events coming in over the channel */
static void process_event(JSONMessageParser *parser, QList *tokens)
{
    GAState *s = container_of(parser, GAState, parser);
    QObject *obj;
    QDict *qdict;
    Error *err = NULL;
    int ret;

    g_assert(s && parser);

    g_debug("process_event: called");
    obj = json_parser_parse_err(tokens, NULL, &err);
    if (err || !obj || qobject_type(obj) != QTYPE_QDICT) {
        qobject_decref(obj);
        qdict = qdict_new();
        if (!err) {
            g_warning("failed to parse event: unknown error");
            error_set(&err, QERR_JSON_PARSING);
        } else {
            g_warning("failed to parse event: %s", error_get_pretty(err));
        }
        qdict_put_obj(qdict, "error", error_get_qobject(err));
        error_free(err);
    } else {
        qdict = qobject_to_qdict(obj);
    }

    g_assert(qdict);

    /* handle host->guest commands */
    if (qdict_haskey(qdict, "execute")) {
        process_command(s, qdict);
    } else {
        if (!qdict_haskey(qdict, "error")) {
            QDECREF(qdict);
            qdict = qdict_new();
            g_warning("unrecognized payload format");
            error_set(&err, QERR_UNSUPPORTED);
            qdict_put_obj(qdict, "error", error_get_qobject(err));
            error_free(err);
        }
        ret = send_response(s, QOBJECT(qdict));
        if (ret) {
            g_warning("error sending error response: %s", strerror(ret));
        }
    }

    QDECREF(qdict);
}

/* false return signals GAChannel to close the current client connection */
static gboolean channel_event_cb(GIOCondition condition, gpointer data)
{
    GAState *s = data;
    gchar buf[QGA_READ_COUNT_DEFAULT+1];
    gsize count;
    GError *err = NULL;
    GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
    if (err != NULL) {
        g_warning("error reading channel: %s", err->message);
        g_error_free(err);
        return false;
    }
    switch (status) {
    case G_IO_STATUS_ERROR:
        g_warning("error reading channel");
        return false;
    case G_IO_STATUS_NORMAL:
        buf[count] = 0;
        g_debug("read data, count: %d, data: %s", (int)count, buf);
        json_message_parser_feed(&s->parser, (char *)buf, (int)count);
        break;
    case G_IO_STATUS_EOF:
        g_debug("received EOF");
        if (!s->virtio) {
            return false;
        }
    case G_IO_STATUS_AGAIN:
        /* virtio causes us to spin here when no process is attached to
         * host-side chardev. sleep a bit to mitigate this
         */
        if (s->virtio) {
            usleep(100*1000);
        }
        return true;
    default:
        g_warning("unknown channel read status, closing");
        return false;
    }
    return true;
}

static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
{
    GAChannelMethod channel_method;

    if (method == NULL) {
        method = "virtio-serial";
    }

    if (path == NULL) {
        if (strcmp(method, "virtio-serial") != 0) {
            g_critical("must specify a path for this channel");
            return false;
        }
        /* try the default path for the virtio-serial port */
        path = QGA_VIRTIO_PATH_DEFAULT;
    }

    if (strcmp(method, "virtio-serial") == 0) {
        s->virtio = true; /* virtio requires special handling in some cases */
        channel_method = GA_CHANNEL_VIRTIO_SERIAL;
    } else if (strcmp(method, "isa-serial") == 0) {
        channel_method = GA_CHANNEL_ISA_SERIAL;
    } else if (strcmp(method, "unix-listen") == 0) {
        channel_method = GA_CHANNEL_UNIX_LISTEN;
    } else {
        g_critical("unsupported channel method/type: %s", method);
        return false;
    }

    s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
    if (!s->channel) {
        g_critical("failed to create guest agent channel");
        return false;
    }

    return true;
}

#ifdef _WIN32
DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
                                  LPVOID ctx)
{
    DWORD ret = NO_ERROR;
    GAService *service = &ga_state->service;

    switch (ctrl)
    {
        case SERVICE_CONTROL_STOP:
        case SERVICE_CONTROL_SHUTDOWN:
            quit_handler(SIGTERM);
            service->status.dwCurrentState = SERVICE_STOP_PENDING;
            SetServiceStatus(service->status_handle, &service->status);
            break;

        default:
            ret = ERROR_CALL_NOT_IMPLEMENTED;
    }
    return ret;
}

VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
{
    GAService *service = &ga_state->service;

    service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
        service_ctrl_handler, NULL);

    if (service->status_handle == 0) {
        g_critical("Failed to register extended requests function!\n");
        return;
    }

    service->status.dwServiceType = SERVICE_WIN32;
    service->status.dwCurrentState = SERVICE_RUNNING;
    service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
    service->status.dwWin32ExitCode = NO_ERROR;
    service->status.dwServiceSpecificExitCode = NO_ERROR;
    service->status.dwCheckPoint = 0;
    service->status.dwWaitHint = 0;
    SetServiceStatus(service->status_handle, &service->status);

    g_main_loop_run(ga_state->main_loop);

    service->status.dwCurrentState = SERVICE_STOPPED;
    SetServiceStatus(service->status_handle, &service->status);
}
#endif

int main(int argc, char **argv)
{
    const char *sopt = "hVvdm:p:l:f:b:s:t:";
    const char *method = NULL, *path = NULL;
    const char *log_filepath = NULL;
    const char *pid_filepath = QGA_PIDFILE_DEFAULT;
    const char *state_dir = QGA_STATEDIR_DEFAULT;
#ifdef _WIN32
    const char *service = NULL;
#endif
    const struct option lopt[] = {
        { "help", 0, NULL, 'h' },
        { "version", 0, NULL, 'V' },
        { "logfile", 1, NULL, 'l' },
        { "pidfile", 1, NULL, 'f' },
        { "verbose", 0, NULL, 'v' },
        { "method", 1, NULL, 'm' },
        { "path", 1, NULL, 'p' },
        { "daemonize", 0, NULL, 'd' },
        { "blacklist", 1, NULL, 'b' },
#ifdef _WIN32
        { "service", 1, NULL, 's' },
#endif
        { "statedir", 1, NULL, 't' },
        { NULL, 0, NULL, 0 }
    };
    int opt_ind = 0, ch, daemonize = 0, i, j, len;
    GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
    GList *blacklist = NULL;
    GAState *s;

    module_call_init(MODULE_INIT_QAPI);

    while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
        switch (ch) {
        case 'm':
            method = optarg;
            break;
        case 'p':
            path = optarg;
            break;
        case 'l':
            log_filepath = optarg;
            break;
        case 'f':
            pid_filepath = optarg;
            break;
        case 't':
             state_dir = optarg;
             break;
        case 'v':
            /* enable all log levels */
            log_level = G_LOG_LEVEL_MASK;
            break;
        case 'V':
            printf("QEMU Guest Agent %s\n", QEMU_VERSION);
            return 0;
        case 'd':
            daemonize = 1;
            break;
        case 'b': {
            char **list_head, **list;
            if (*optarg == '?') {
                list_head = list = qmp_get_command_list();
                while (*list != NULL) {
                    printf("%s\n", *list);
                    g_free(*list);
                    list++;
                }
                g_free(list_head);
                return 0;
            }
            for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
                if (optarg[i] == ',') {
                    optarg[i] = 0;
                    blacklist = g_list_append(blacklist, &optarg[j]);
                    j = i + 1;
                }
            }
            if (j < i) {
                blacklist = g_list_append(blacklist, &optarg[j]);
            }
            break;
        }
#ifdef _WIN32
        case 's':
            service = optarg;
            if (strcmp(service, "install") == 0) {
                return ga_install_service(path, log_filepath);
            } else if (strcmp(service, "uninstall") == 0) {
                return ga_uninstall_service();
            } else {
                printf("Unknown service command.\n");
                return EXIT_FAILURE;
            }
            break;
#endif
        case 'h':
            usage(argv[0]);
            return 0;
        case '?':
            g_print("Unknown option, try '%s --help' for more information.\n",
                    argv[0]);
            return EXIT_FAILURE;
        }
    }

    s = g_malloc0(sizeof(GAState));
    s->log_level = log_level;
    s->log_file = stderr;
    g_log_set_default_handler(ga_log, s);
    g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
    ga_enable_logging(s);
    s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
                                                 state_dir);
    s->frozen = false;
#ifndef _WIN32
    /* check if a previous instance of qemu-ga exited with filesystems' state
     * marked as frozen. this could be a stale value (a non-qemu-ga process
     * or reboot may have since unfrozen them), but better to require an
     * uneeded unfreeze than to risk hanging on start-up
     */
    struct stat st;
    if (stat(s->state_filepath_isfrozen, &st) == -1) {
        /* it's okay if the file doesn't exist, but if we can't access for
         * some other reason, such as permissions, there's a configuration
         * that needs to be addressed. so just bail now before we get into
         * more trouble later
         */
        if (errno != ENOENT) {
            g_critical("unable to access state file at path %s: %s",
                       s->state_filepath_isfrozen, strerror(errno));
            return EXIT_FAILURE;
        }
    } else {
        g_warning("previous instance appears to have exited with frozen"
                  " filesystems. deferring logging/pidfile creation and"
                  " disabling non-fsfreeze-safe commands until"
                  " guest-fsfreeze-thaw is issued, or filesystems are"
                  " manually unfrozen and the file %s is removed",
                  s->state_filepath_isfrozen);
        s->frozen = true;
    }
#endif

    if (ga_is_frozen(s)) {
        if (daemonize) {
            /* delay opening/locking of pidfile till filesystem are unfrozen */
            s->deferred_options.pid_filepath = pid_filepath;
            become_daemon(NULL);
        }
        if (log_filepath) {
            /* delay opening the log file till filesystems are unfrozen */
            s->deferred_options.log_filepath = log_filepath;
        }
        ga_disable_logging(s);
        ga_disable_non_whitelisted();
    } else {
        if (daemonize) {
            become_daemon(pid_filepath);
        }
        if (log_filepath) {
            FILE *log_file = fopen(log_filepath, "a");
            if (!log_file) {
                g_critical("unable to open specified log file: %s",
                           strerror(errno));
                goto out_bad;
            }
            s->log_file = log_file;
        }
    }

    if (blacklist) {
        s->blacklist = blacklist;
        do {
            g_debug("disabling command: %s", (char *)blacklist->data);
            qmp_disable_command(blacklist->data);
            blacklist = g_list_next(blacklist);
        } while (blacklist);
    }
    s->command_state = ga_command_state_new();
    ga_command_state_init(s, s->command_state);
    ga_command_state_init_all(s->command_state);
    json_message_parser_init(&s->parser, process_event);
    ga_state = s;
#ifndef _WIN32
    if (!register_signal_handlers()) {
        g_critical("failed to register signal handlers");
        goto out_bad;
    }
#endif

    s->main_loop = g_main_loop_new(NULL, false);
    if (!channel_init(ga_state, method, path)) {
        g_critical("failed to initialize guest agent channel");
        goto out_bad;
    }
#ifndef _WIN32
    g_main_loop_run(ga_state->main_loop);
#else
    if (daemonize) {
        SERVICE_TABLE_ENTRY service_table[] = {
            { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
        StartServiceCtrlDispatcher(service_table);
    } else {
        g_main_loop_run(ga_state->main_loop);
    }
#endif

    ga_command_state_cleanup_all(ga_state->command_state);
    ga_channel_free(ga_state->channel);

    if (daemonize) {
        unlink(pid_filepath);
    }
    return 0;

out_bad:
    if (daemonize) {
        unlink(pid_filepath);
    }
    return EXIT_FAILURE;
}