qemu-ga.c

   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 #include <stdlib.h>
  14 #include <stdio.h>
  15 #include <stdbool.h>
  16 #include <glib.h>
  17 #include <getopt.h>
  18 #ifndef _WIN32
  19 #include <syslog.h>
  20 #include <sys/wait.h>
  21 #include <sys/stat.h>
  22 #endif
  23 #include "json-streamer.h"
  24 #include "json-parser.h"
  25 #include "qint.h"
  26 #include "qjson.h"
  27 #include "qga/guest-agent-core.h"
  28 #include "module.h"
  29 #include "signal.h"
  30 #include "qerror.h"
  31 #include "error_int.h"
  32 #include "qapi/qmp-core.h"
  33 #include "qga/channel.h"
  34 #ifdef _WIN32
  35 #include "qga/service-win32.h"
  36 #include <windows.h>
  37 #endif
  38
  39 #ifndef _WIN32
  40 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
  41 #else
  42 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
  43 #endif
  44 #define QGA_PIDFILE_DEFAULT "/var/run/qemu-ga.pid"
  45 #define QGA_STATEDIR_DEFAULT "/tmp"
  46 #define QGA_SENTINEL_BYTE 0xFF
  47
  48 struct GAState {
  49     JSONMessageParser parser;
  50     GMainLoop *main_loop;
  51     GAChannel *channel;
  52     bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
  53     GACommandState *command_state;
  54     GLogLevelFlags log_level;
  55     FILE *log_file;
  56     bool logging_enabled;
  57 #ifdef _WIN32
  58     GAService service;
  59 #endif
  60     bool delimit_response;
  61     bool frozen;
  62     GList *blacklist;
  63     const char *state_filepath_isfrozen;
  64     struct {
  65         const char *log_filepath;
  66         const char *pid_filepath;
  67     } deferred_options;
  68 };
  69
  70 struct GAState *ga_state;
  71
  72 /* commands that are safe to issue while filesystems are frozen */
  73 static const char *ga_freeze_whitelist[] = {
  74     "guest-ping",
  75     "guest-info",
  76     "guest-sync",
  77     "guest-fsfreeze-status",
  78     "guest-fsfreeze-thaw",
  79     NULL
  80 };
  81
  82 #ifdef _WIN32
  83 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
  84                                   LPVOID ctx);
  85 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
  86 #endif
  87
  88 static void quit_handler(int sig)
  89 {
  90     /* if we're frozen, don't exit unless we're absolutely forced to,
  91      * because it's basically impossible for graceful exit to complete
  92      * unless all log/pid files are on unfreezable filesystems. there's
  93      * also a very likely chance killing the agent before unfreezing
  94      * the filesystems is a mistake (or will be viewed as one later).
  95      */
  96     if (ga_is_frozen(ga_state)) {
  97         return;
  98     }
  99     g_debug("received signal num %d, quitting", sig);
 100
 101     if (g_main_loop_is_running(ga_state->main_loop)) {
 102         g_main_loop_quit(ga_state->main_loop);
 103     }
 104 }
 105
 106 #ifndef _WIN32
 107 /* reap _all_ terminated children */
 108 static void child_handler(int sig)
 109 {
 110     int status;
 111     while (waitpid(-1, &status, WNOHANG) > 0) /* NOTHING */;
 112 }
 113
 114 static gboolean register_signal_handlers(void)
 115 {
 116     struct sigaction sigact, sigact_chld;
 117     int ret;
 118
 119     memset(&sigact, 0, sizeof(struct sigaction));
 120     sigact.sa_handler = quit_handler;
 121
 122     ret = sigaction(SIGINT, &sigact, NULL);
 123     if (ret == -1) {
 124         g_error("error configuring signal handler: %s", strerror(errno));
 125         return false;
 126     }
 127     ret = sigaction(SIGTERM, &sigact, NULL);
 128     if (ret == -1) {
 129         g_error("error configuring signal handler: %s", strerror(errno));
 130         return false;
 131     }
 132
 133     memset(&sigact_chld, 0, sizeof(struct sigaction));
 134     sigact_chld.sa_handler = child_handler;
 135     sigact_chld.sa_flags = SA_NOCLDSTOP;
 136     ret = sigaction(SIGCHLD, &sigact_chld, NULL);
 137     if (ret == -1) {
 138         g_error("error configuring signal handler: %s", strerror(errno));
 139     }
 140
 141     return true;
 142 }
 143 #endif
 144
 145 static void usage(const char *cmd)
 146 {
 147     printf(
 148 "Usage: %s [-m <method> -p <path>] [<options>]\n"
 149 "QEMU Guest Agent %s\n"
 150 "\n"
 151 "  -m, --method      transport method: one of unix-listen, virtio-serial, or\n"
 152 "                    isa-serial (virtio-serial is the default)\n"
 153 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
 154 "                    %s)\n"
 155 "  -l, --logfile     set logfile path, logs to stderr by default\n"
 156 "  -f, --pidfile     specify pidfile (default is %s)\n"
 157 "  -t, --statedir    specify dir to store state information (absolute paths\n"
 158 "                    only, default is %s)\n"
 159 "  -v, --verbose     log extra debugging information\n"
 160 "  -V, --version     print version information and exit\n"
 161 "  -d, --daemonize   become a daemon\n"
 162 #ifdef _WIN32
 163 "  -s, --service     service commands: install, uninstall\n"
 164 #endif
 165 "  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\"\n"
 166 "                    to list available RPCs)\n"
 167 "  -h, --help        display this help and exit\n"
 168 "\n"
 169 "Report bugs to <mdroth@linux.vnet.ibm.com>\n"
 170     , cmd, QGA_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT,
 171     QGA_STATEDIR_DEFAULT);
 172 }
 173
 174 static const char *ga_log_level_str(GLogLevelFlags level)
 175 {
 176     switch (level & G_LOG_LEVEL_MASK) {
 177         case G_LOG_LEVEL_ERROR:
 178             return "error";
 179         case G_LOG_LEVEL_CRITICAL:
 180             return "critical";
 181         case G_LOG_LEVEL_WARNING:
 182             return "warning";
 183         case G_LOG_LEVEL_MESSAGE:
 184             return "message";
 185         case G_LOG_LEVEL_INFO:
 186             return "info";
 187         case G_LOG_LEVEL_DEBUG:
 188             return "debug";
 189         default:
 190             return "user";
 191     }
 192 }
 193
 194 bool ga_logging_enabled(GAState *s)
 195 {
 196     return s->logging_enabled;
 197 }
 198
 199 void ga_disable_logging(GAState *s)
 200 {
 201     s->logging_enabled = false;
 202 }
 203
 204 void ga_enable_logging(GAState *s)
 205 {
 206     s->logging_enabled = true;
 207 }
 208
 209 static void ga_log(const gchar *domain, GLogLevelFlags level,
 210                    const gchar *msg, gpointer opaque)
 211 {
 212     GAState *s = opaque;
 213     GTimeVal time;
 214     const char *level_str = ga_log_level_str(level);
 215
 216     if (!ga_logging_enabled(s)) {
 217         return;
 218     }
 219
 220     level &= G_LOG_LEVEL_MASK;
 221 #ifndef _WIN32
 222     if (domain && strcmp(domain, "syslog") == 0) {
 223         syslog(LOG_INFO, "%s: %s", level_str, msg);
 224     } else if (level & s->log_level) {
 225 #else
 226     if (level & s->log_level) {
 227 #endif
 228         g_get_current_time(&time);
 229         fprintf(s->log_file,
 230                 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
 231         fflush(s->log_file);
 232     }
 233 }
 234
 235 void ga_set_response_delimited(GAState *s)
 236 {
 237     s->delimit_response = true;
 238 }
 239
 240 #ifndef _WIN32
 241 static bool ga_open_pidfile(const char *pidfile)
 242 {
 243     int pidfd;
 244     char pidstr[32];
 245
 246     pidfd = open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
 247     if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) {
 248         g_critical("Cannot lock pid file, %s", strerror(errno));
 249         return false;
 250     }
 251
 252     if (ftruncate(pidfd, 0) || lseek(pidfd, 0, SEEK_SET)) {
 253         g_critical("Failed to truncate pid file");
 254         goto fail;
 255     }
 256     sprintf(pidstr, "%d", getpid());
 257     if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
 258         g_critical("Failed to write pid file");
 259         goto fail;
 260     }
 261
 262     return true;
 263
 264 fail:
 265     unlink(pidfile);
 266     return false;
 267 }
 268 #else /* _WIN32 */
 269 static bool ga_open_pidfile(const char *pidfile)
 270 {
 271     return true;
 272 }
 273 #endif
 274
 275 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
 276 {
 277     return strcmp(str1, str2);
 278 }
 279
 280 /* disable commands that aren't safe for fsfreeze */
 281 static void ga_disable_non_whitelisted(void)
 282 {
 283     char **list_head, **list;
 284     bool whitelisted;
 285     int i;
 286
 287     list_head = list = qmp_get_command_list();
 288     while (*list != NULL) {
 289         whitelisted = false;
 290         i = 0;
 291         while (ga_freeze_whitelist[i] != NULL) {
 292             if (strcmp(*list, ga_freeze_whitelist[i]) == 0) {
 293                 whitelisted = true;
 294             }
 295             i++;
 296         }
 297         if (!whitelisted) {
 298             g_debug("disabling command: %s", *list);
 299             qmp_disable_command(*list);
 300         }
 301         g_free(*list);
 302         list++;
 303     }
 304     g_free(list_head);
 305 }
 306
 307 /* [re-]enable all commands, except those explicitly blacklisted by user */
 308 static void ga_enable_non_blacklisted(GList *blacklist)
 309 {
 310     char **list_head, **list;
 311
 312     list_head = list = qmp_get_command_list();
 313     while (*list != NULL) {
 314         if (g_list_find_custom(blacklist, *list, ga_strcmp) == NULL &&
 315             !qmp_command_is_enabled(*list)) {
 316             g_debug("enabling command: %s", *list);
 317             qmp_enable_command(*list);
 318         }
 319         g_free(*list);
 320         list++;
 321     }
 322     g_free(list_head);
 323 }
 324
 325 static bool ga_create_file(const char *path)
 326 {
 327     int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
 328     if (fd == -1) {
 329         g_warning("unable to open/create file %s: %s", path, strerror(errno));
 330         return false;
 331     }
 332     close(fd);
 333     return true;
 334 }
 335
 336 static bool ga_delete_file(const char *path)
 337 {
 338     int ret = unlink(path);
 339     if (ret == -1) {
 340         g_warning("unable to delete file: %s: %s", path, strerror(errno));
 341         return false;
 342     }
 343
 344     return true;
 345 }
 346
 347 bool ga_is_frozen(GAState *s)
 348 {
 349     return s->frozen;
 350 }
 351
 352 void ga_set_frozen(GAState *s)
 353 {
 354     if (ga_is_frozen(s)) {
 355         return;
 356     }
 357     /* disable all non-whitelisted (for frozen state) commands */
 358     ga_disable_non_whitelisted();
 359     g_warning("disabling logging due to filesystem freeze");
 360     ga_disable_logging(s);
 361     s->frozen = true;
 362     if (!ga_create_file(s->state_filepath_isfrozen)) {
 363         g_warning("unable to create %s, fsfreeze may not function properly",
 364                   s->state_filepath_isfrozen);
 365     }
 366 }
 367
 368 void ga_unset_frozen(GAState *s)
 369 {
 370     if (!ga_is_frozen(s)) {
 371         return;
 372     }
 373
 374     /* if we delayed creation/opening of pid/log files due to being
 375      * in a frozen state at start up, do it now
 376      */
 377     if (s->deferred_options.log_filepath) {
 378         s->log_file = fopen(s->deferred_options.log_filepath, "a");
 379         if (!s->log_file) {
 380             s->log_file = stderr;
 381         }
 382         s->deferred_options.log_filepath = NULL;
 383     }
 384     ga_enable_logging(s);
 385     g_warning("logging re-enabled due to filesystem unfreeze");
 386     if (s->deferred_options.pid_filepath) {
 387         if (!ga_open_pidfile(s->deferred_options.pid_filepath)) {
 388             g_warning("failed to create/open pid file");
 389         }
 390         s->deferred_options.pid_filepath = NULL;
 391     }
 392
 393     /* enable all disabled, non-blacklisted commands */
 394     ga_enable_non_blacklisted(s->blacklist);
 395     s->frozen = false;
 396     if (!ga_delete_file(s->state_filepath_isfrozen)) {
 397         g_warning("unable to delete %s, fsfreeze may not function properly",
 398                   s->state_filepath_isfrozen);
 399     }
 400 }
 401
 402 static void become_daemon(const char *pidfile)
 403 {
 404 #ifndef _WIN32
 405     pid_t pid, sid;
 406
 407     pid = fork();
 408     if (pid < 0) {
 409         exit(EXIT_FAILURE);
 410     }
 411     if (pid > 0) {
 412         exit(EXIT_SUCCESS);
 413     }
 414
 415     if (pidfile) {
 416         if (!ga_open_pidfile(pidfile)) {
 417             g_critical("failed to create pidfile");
 418             exit(EXIT_FAILURE);
 419         }
 420     }
 421
 422     umask(0);
 423     sid = setsid();
 424     if (sid < 0) {
 425         goto fail;
 426     }
 427     if ((chdir("/")) < 0) {
 428         goto fail;
 429     }
 430
 431     close(STDIN_FILENO);
 432     close(STDOUT_FILENO);
 433     close(STDERR_FILENO);
 434     return;
 435
 436 fail:
 437     unlink(pidfile);
 438     g_critical("failed to daemonize");
 439     exit(EXIT_FAILURE);
 440 #endif
 441 }
 442
 443 static int send_response(GAState *s, QObject *payload)
 444 {
 445     const char *buf;
 446     QString *payload_qstr, *response_qstr;
 447     GIOStatus status;
 448
 449     g_assert(payload && s->channel);
 450
 451     payload_qstr = qobject_to_json(payload);
 452     if (!payload_qstr) {
 453         return -EINVAL;
 454     }
 455
 456     if (s->delimit_response) {
 457         s->delimit_response = false;
 458         response_qstr = qstring_new();
 459         qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
 460         qstring_append(response_qstr, qstring_get_str(payload_qstr));
 461         QDECREF(payload_qstr);
 462     } else {
 463         response_qstr = payload_qstr;
 464     }
 465
 466     qstring_append_chr(response_qstr, '\n');
 467     buf = qstring_get_str(response_qstr);
 468     status = ga_channel_write_all(s->channel, buf, strlen(buf));
 469     QDECREF(response_qstr);
 470     if (status != G_IO_STATUS_NORMAL) {
 471         return -EIO;
 472     }
 473
 474     return 0;
 475 }
 476
 477 static void process_command(GAState *s, QDict *req)
 478 {
 479     QObject *rsp = NULL;
 480     int ret;
 481
 482     g_assert(req);
 483     g_debug("processing command");
 484     rsp = qmp_dispatch(QOBJECT(req));
 485     if (rsp) {
 486         ret = send_response(s, rsp);
 487         if (ret) {
 488             g_warning("error sending response: %s", strerror(ret));
 489         }
 490         qobject_decref(rsp);
 491     }
 492 }
 493
 494 /* handle requests/control events coming in over the channel */
 495 static void process_event(JSONMessageParser *parser, QList *tokens)
 496 {
 497     GAState *s = container_of(parser, GAState, parser);
 498     QObject *obj;
 499     QDict *qdict;
 500     Error *err = NULL;
 501     int ret;
 502
 503     g_assert(s && parser);
 504
 505     g_debug("process_event: called");
 506     obj = json_parser_parse_err(tokens, NULL, &err);
 507     if (err || !obj || qobject_type(obj) != QTYPE_QDICT) {
 508         qobject_decref(obj);
 509         qdict = qdict_new();
 510         if (!err) {
 511             g_warning("failed to parse event: unknown error");
 512             error_set(&err, QERR_JSON_PARSING);
 513         } else {
 514             g_warning("failed to parse event: %s", error_get_pretty(err));
 515         }
 516         qdict_put_obj(qdict, "error", error_get_qobject(err));
 517         error_free(err);
 518     } else {
 519         qdict = qobject_to_qdict(obj);
 520     }
 521
 522     g_assert(qdict);
 523
 524     /* handle host->guest commands */
 525     if (qdict_haskey(qdict, "execute")) {
 526         process_command(s, qdict);
 527     } else {
 528         if (!qdict_haskey(qdict, "error")) {
 529             QDECREF(qdict);
 530             qdict = qdict_new();
 531             g_warning("unrecognized payload format");
 532             error_set(&err, QERR_UNSUPPORTED);
 533             qdict_put_obj(qdict, "error", error_get_qobject(err));
 534             error_free(err);
 535         }
 536         ret = send_response(s, QOBJECT(qdict));
 537         if (ret) {
 538             g_warning("error sending error response: %s", strerror(ret));
 539         }
 540     }
 541
 542     QDECREF(qdict);
 543 }
 544
 545 /* false return signals GAChannel to close the current client connection */
 546 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 547 {
 548     GAState *s = data;
 549     gchar buf[QGA_READ_COUNT_DEFAULT+1];
 550     gsize count;
 551     GError *err = NULL;
 552     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 553     if (err != NULL) {
 554         g_warning("error reading channel: %s", err->message);
 555         g_error_free(err);
 556         return false;
 557     }
 558     switch (status) {
 559     case G_IO_STATUS_ERROR:
 560         g_warning("error reading channel");
 561         return false;
 562     case G_IO_STATUS_NORMAL:
 563         buf[count] = 0;
 564         g_debug("read data, count: %d, data: %s", (int)count, buf);
 565         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 566         break;
 567     case G_IO_STATUS_EOF:
 568         g_debug("received EOF");
 569         if (!s->virtio) {
 570             return false;
 571         }
 572     case G_IO_STATUS_AGAIN:
 573         /* virtio causes us to spin here when no process is attached to
 574          * host-side chardev. sleep a bit to mitigate this
 575          */
 576         if (s->virtio) {
 577             usleep(100*1000);
 578         }
 579         return true;
 580     default:
 581         g_warning("unknown channel read status, closing");
 582         return false;
 583     }
 584     return true;
 585 }
 586
 587 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
 588 {
 589     GAChannelMethod channel_method;
 590
 591     if (method == NULL) {
 592         method = "virtio-serial";
 593     }
 594
 595     if (path == NULL) {
 596         if (strcmp(method, "virtio-serial") != 0) {
 597             g_critical("must specify a path for this channel");
 598             return false;
 599         }
 600         /* try the default path for the virtio-serial port */
 601         path = QGA_VIRTIO_PATH_DEFAULT;
 602     }
 603
 604     if (strcmp(method, "virtio-serial") == 0) {
 605         s->virtio = true; /* virtio requires special handling in some cases */
 606         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 607     } else if (strcmp(method, "isa-serial") == 0) {
 608         channel_method = GA_CHANNEL_ISA_SERIAL;
 609     } else if (strcmp(method, "unix-listen") == 0) {
 610         channel_method = GA_CHANNEL_UNIX_LISTEN;
 611     } else {
 612         g_critical("unsupported channel method/type: %s", method);
 613         return false;
 614     }
 615
 616     s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
 617     if (!s->channel) {
 618         g_critical("failed to create guest agent channel");
 619         return false;
 620     }
 621
 622     return true;
 623 }
 624
 625 #ifdef _WIN32
 626 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 627                                   LPVOID ctx)
 628 {
 629     DWORD ret = NO_ERROR;
 630     GAService *service = &ga_state->service;
 631
 632     switch (ctrl)
 633     {
 634         case SERVICE_CONTROL_STOP:
 635         case SERVICE_CONTROL_SHUTDOWN:
 636             quit_handler(SIGTERM);
 637             service->status.dwCurrentState = SERVICE_STOP_PENDING;
 638             SetServiceStatus(service->status_handle, &service->status);
 639             break;
 640
 641         default:
 642             ret = ERROR_CALL_NOT_IMPLEMENTED;
 643     }
 644     return ret;
 645 }
 646
 647 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 648 {
 649     GAService *service = &ga_state->service;
 650
 651     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 652         service_ctrl_handler, NULL);
 653
 654     if (service->status_handle == 0) {
 655         g_critical("Failed to register extended requests function!\n");
 656         return;
 657     }
 658
 659     service->status.dwServiceType = SERVICE_WIN32;
 660     service->status.dwCurrentState = SERVICE_RUNNING;
 661     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 662     service->status.dwWin32ExitCode = NO_ERROR;
 663     service->status.dwServiceSpecificExitCode = NO_ERROR;
 664     service->status.dwCheckPoint = 0;
 665     service->status.dwWaitHint = 0;
 666     SetServiceStatus(service->status_handle, &service->status);
 667
 668     g_main_loop_run(ga_state->main_loop);
 669
 670     service->status.dwCurrentState = SERVICE_STOPPED;
 671     SetServiceStatus(service->status_handle, &service->status);
 672 }
 673 #endif
 674
 675 int main(int argc, char **argv)
 676 {
 677     const char *sopt = "hVvdm:p:l:f:b:s:t:";
 678     const char *method = NULL, *path = NULL;
 679     const char *log_filepath = NULL;
 680     const char *pid_filepath = QGA_PIDFILE_DEFAULT;
 681     const char *state_dir = QGA_STATEDIR_DEFAULT;
 682 #ifdef _WIN32
 683     const char *service = NULL;
 684 #endif
 685     const struct option lopt[] = {
 686         { "help", 0, NULL, 'h' },
 687         { "version", 0, NULL, 'V' },
 688         { "logfile", 1, NULL, 'l' },
 689         { "pidfile", 1, NULL, 'f' },
 690         { "verbose", 0, NULL, 'v' },
 691         { "method", 1, NULL, 'm' },
 692         { "path", 1, NULL, 'p' },
 693         { "daemonize", 0, NULL, 'd' },
 694         { "blacklist", 1, NULL, 'b' },
 695 #ifdef _WIN32
 696         { "service", 1, NULL, 's' },
 697 #endif
 698         { "statedir", 1, NULL, 't' },
 699         { NULL, 0, NULL, 0 }
 700     };
 701     int opt_ind = 0, ch, daemonize = 0, i, j, len;
 702     GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
 703     GList *blacklist = NULL;
 704     GAState *s;
 705
 706     module_call_init(MODULE_INIT_QAPI);
 707
 708     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 709         switch (ch) {
 710         case 'm':
 711             method = optarg;
 712             break;
 713         case 'p':
 714             path = optarg;
 715             break;
 716         case 'l':
 717             log_filepath = optarg;
 718             break;
 719         case 'f':
 720             pid_filepath = optarg;
 721             break;
 722         case 't':
 723              state_dir = optarg;
 724              break;
 725         case 'v':
 726             /* enable all log levels */
 727             log_level = G_LOG_LEVEL_MASK;
 728             break;
 729         case 'V':
 730             printf("QEMU Guest Agent %s\n", QGA_VERSION);
 731             return 0;
 732         case 'd':
 733             daemonize = 1;
 734             break;
 735         case 'b': {
 736             char **list_head, **list;
 737             if (*optarg == '?') {
 738                 list_head = list = qmp_get_command_list();
 739                 while (*list != NULL) {
 740                     printf("%s\n", *list);
 741                     g_free(*list);
 742                     list++;
 743                 }
 744                 g_free(list_head);
 745                 return 0;
 746             }
 747             for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
 748                 if (optarg[i] == ',') {
 749                     optarg[i] = 0;
 750                     blacklist = g_list_append(blacklist, &optarg[j]);
 751                     j = i + 1;
 752                 }
 753             }
 754             if (j < i) {
 755                 blacklist = g_list_append(blacklist, &optarg[j]);
 756             }
 757             break;
 758         }
 759 #ifdef _WIN32
 760         case 's':
 761             service = optarg;
 762             if (strcmp(service, "install") == 0) {
 763                 return ga_install_service(path, log_filepath);
 764             } else if (strcmp(service, "uninstall") == 0) {
 765                 return ga_uninstall_service();
 766             } else {
 767                 printf("Unknown service command.\n");
 768                 return EXIT_FAILURE;
 769             }
 770             break;
 771 #endif
 772         case 'h':
 773             usage(argv[0]);
 774             return 0;
 775         case '?':
 776             g_print("Unknown option, try '%s --help' for more information.\n",
 777                     argv[0]);
 778             return EXIT_FAILURE;
 779         }
 780     }
 781
 782     s = g_malloc0(sizeof(GAState));
 783     s->log_level = log_level;
 784     s->log_file = stderr;
 785     g_log_set_default_handler(ga_log, s);
 786     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
 787     ga_enable_logging(s);
 788     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
 789                                                  state_dir);
 790     s->frozen = false;
 791 #ifndef _WIN32
 792     /* check if a previous instance of qemu-ga exited with filesystems' state
 793      * marked as frozen. this could be a stale value (a non-qemu-ga process
 794      * or reboot may have since unfrozen them), but better to require an
 795      * uneeded unfreeze than to risk hanging on start-up
 796      */
 797     struct stat st;
 798     if (stat(s->state_filepath_isfrozen, &st) == -1) {
 799         /* it's okay if the file doesn't exist, but if we can't access for
 800          * some other reason, such as permissions, there's a configuration
 801          * that needs to be addressed. so just bail now before we get into
 802          * more trouble later
 803          */
 804         if (errno != ENOENT) {
 805             g_critical("unable to access state file at path %s: %s",
 806                        s->state_filepath_isfrozen, strerror(errno));
 807             return EXIT_FAILURE;
 808         }
 809     } else {
 810         g_warning("previous instance appears to have exited with frozen"
 811                   " filesystems. deferring logging/pidfile creation and"
 812                   " disabling non-fsfreeze-safe commands until"
 813                   " guest-fsfreeze-thaw is issued, or filesystems are"
 814                   " manually unfrozen and the file %s is removed",
 815                   s->state_filepath_isfrozen);
 816         s->frozen = true;
 817     }
 818 #endif
 819
 820     if (ga_is_frozen(s)) {
 821         if (daemonize) {
 822             /* delay opening/locking of pidfile till filesystem are unfrozen */
 823             s->deferred_options.pid_filepath = pid_filepath;
 824             become_daemon(NULL);
 825         }
 826         if (log_filepath) {
 827             /* delay opening the log file till filesystems are unfrozen */
 828             s->deferred_options.log_filepath = log_filepath;
 829         }
 830         ga_disable_logging(s);
 831         ga_disable_non_whitelisted();
 832     } else {
 833         if (daemonize) {
 834             become_daemon(pid_filepath);
 835         }
 836         if (log_filepath) {
 837             s->log_file = fopen(log_filepath, "a");
 838             if (!s->log_file) {
 839                 g_critical("unable to open specified log file: %s",
 840                            strerror(errno));
 841                 goto out_bad;
 842             }
 843         }
 844     }
 845
 846     if (blacklist) {
 847         s->blacklist = blacklist;
 848         do {
 849             g_debug("disabling command: %s", (char *)blacklist->data);
 850             qmp_disable_command(blacklist->data);
 851             blacklist = g_list_next(blacklist);
 852         } while (blacklist);
 853     }
 854     s->command_state = ga_command_state_new();
 855     ga_command_state_init(s, s->command_state);
 856     ga_command_state_init_all(s->command_state);
 857     json_message_parser_init(&s->parser, process_event);
 858     ga_state = s;
 859 #ifndef _WIN32
 860     if (!register_signal_handlers()) {
 861         g_critical("failed to register signal handlers");
 862         goto out_bad;
 863     }
 864 #endif
 865
 866     s->main_loop = g_main_loop_new(NULL, false);
 867     if (!channel_init(ga_state, method, path)) {
 868         g_critical("failed to initialize guest agent channel");
 869         goto out_bad;
 870     }
 871 #ifndef _WIN32
 872     g_main_loop_run(ga_state->main_loop);
 873 #else
 874     if (daemonize) {
 875         SERVICE_TABLE_ENTRY service_table[] = {
 876             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
 877         StartServiceCtrlDispatcher(service_table);
 878     } else {
 879         g_main_loop_run(ga_state->main_loop);
 880     }
 881 #endif
 882
 883     ga_command_state_cleanup_all(ga_state->command_state);
 884     ga_channel_free(ga_state->channel);
 885
 886     if (daemonize) {
 887         unlink(pid_filepath);
 888     }
 889     return 0;
 890
 891 out_bad:
 892     if (daemonize) {
 893         unlink(pid_filepath);
 894     }
 895     return EXIT_FAILURE;
 896 }