qga/main.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 "qapi/qmp/json-streamer.h"
  24 #include "qapi/qmp/json-parser.h"
  25 #include "qapi/qmp/qint.h"
  26 #include "qapi/qmp/qjson.h"
  27 #include "qga/guest-agent-core.h"
  28 #include "qemu/module.h"
  29 #include "signal.h"
  30 #include "qapi/qmp/qerror.h"
  31 #include "qapi/qmp/dispatch.h"
  32 #include "qga/channel.h"
  33 #ifdef _WIN32
  34 #include "qga/service-win32.h"
  35 #include <windows.h>
  36 #endif
  37 #ifdef __linux__
  38 #include <linux/fs.h>
  39 #ifdef FIFREEZE
  40 #define CONFIG_FSFREEZE
  41 #endif
  42 #endif
  43
  44 #ifndef _WIN32
  45 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
  46 #else
  47 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
  48 #endif
  49 #define QGA_STATEDIR_DEFAULT CONFIG_QEMU_LOCALSTATEDIR "/run"
  50 #define QGA_PIDFILE_DEFAULT QGA_STATEDIR_DEFAULT "/qemu-ga.pid"
  51 #ifdef CONFIG_FSFREEZE
  52 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
  53 #endif
  54 #define QGA_SENTINEL_BYTE 0xFF
  55
  56 struct GAState {
  57     JSONMessageParser parser;
  58     GMainLoop *main_loop;
  59     GAChannel *channel;
  60     bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
  61     GACommandState *command_state;
  62     GLogLevelFlags log_level;
  63     FILE *log_file;
  64     bool logging_enabled;
  65 #ifdef _WIN32
  66     GAService service;
  67 #endif
  68     bool delimit_response;
  69     bool frozen;
  70     GList *blacklist;
  71     const char *state_filepath_isfrozen;
  72     struct {
  73         const char *log_filepath;
  74         const char *pid_filepath;
  75     } deferred_options;
  76 #ifdef CONFIG_FSFREEZE
  77     const char *fsfreeze_hook;
  78 #endif
  79 };
  80
  81 struct GAState *ga_state;
  82
  83 /* commands that are safe to issue while filesystems are frozen */
  84 static const char *ga_freeze_whitelist[] = {
  85     "guest-ping",
  86     "guest-info",
  87     "guest-sync",
  88     "guest-sync-delimited",
  89     "guest-fsfreeze-status",
  90     "guest-fsfreeze-thaw",
  91     NULL
  92 };
  93
  94 #ifdef _WIN32
  95 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
  96                                   LPVOID ctx);
  97 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
  98 #endif
  99
 100 static void quit_handler(int sig)
 101 {
 102     /* if we're frozen, don't exit unless we're absolutely forced to,
 103      * because it's basically impossible for graceful exit to complete
 104      * unless all log/pid files are on unfreezable filesystems. there's
 105      * also a very likely chance killing the agent before unfreezing
 106      * the filesystems is a mistake (or will be viewed as one later).
 107      */
 108     if (ga_is_frozen(ga_state)) {
 109         return;
 110     }
 111     g_debug("received signal num %d, quitting", sig);
 112
 113     if (g_main_loop_is_running(ga_state->main_loop)) {
 114         g_main_loop_quit(ga_state->main_loop);
 115     }
 116 }
 117
 118 #ifndef _WIN32
 119 static gboolean register_signal_handlers(void)
 120 {
 121     struct sigaction sigact;
 122     int ret;
 123
 124     memset(&sigact, 0, sizeof(struct sigaction));
 125     sigact.sa_handler = quit_handler;
 126
 127     ret = sigaction(SIGINT, &sigact, NULL);
 128     if (ret == -1) {
 129         g_error("error configuring signal handler: %s", strerror(errno));
 130     }
 131     ret = sigaction(SIGTERM, &sigact, NULL);
 132     if (ret == -1) {
 133         g_error("error configuring signal handler: %s", strerror(errno));
 134     }
 135
 136     return true;
 137 }
 138
 139 /* TODO: use this in place of all post-fork() fclose(std*) callers */
 140 void reopen_fd_to_null(int fd)
 141 {
 142     int nullfd;
 143
 144     nullfd = open("/dev/null", O_RDWR);
 145     if (nullfd < 0) {
 146         return;
 147     }
 148
 149     dup2(nullfd, fd);
 150
 151     if (nullfd != fd) {
 152         close(nullfd);
 153     }
 154 }
 155 #endif
 156
 157 static void usage(const char *cmd)
 158 {
 159     printf(
 160 "Usage: %s [-m <method> -p <path>] [<options>]\n"
 161 "QEMU Guest Agent %s\n"
 162 "\n"
 163 "  -m, --method      transport method: one of unix-listen, virtio-serial, or\n"
 164 "                    isa-serial (virtio-serial is the default)\n"
 165 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
 166 "                    %s)\n"
 167 "  -l, --logfile     set logfile path, logs to stderr by default\n"
 168 "  -f, --pidfile     specify pidfile (default is %s)\n"
 169 #ifdef CONFIG_FSFREEZE
 170 "  -F, --fsfreeze-hook\n"
 171 "                    enable fsfreeze hook. Accepts an optional argument that\n"
 172 "                    specifies script to run on freeze/thaw. Script will be\n"
 173 "                    called with 'freeze'/'thaw' arguments accordingly.\n"
 174 "                    (default is %s)\n"
 175 "                    If using -F with an argument, do not follow -F with a\n"
 176 "                    space.\n"
 177 "                    (for example: -F/var/run/fsfreezehook.sh)\n"
 178 #endif
 179 "  -t, --statedir    specify dir to store state information (absolute paths\n"
 180 "                    only, default is %s)\n"
 181 "  -v, --verbose     log extra debugging information\n"
 182 "  -V, --version     print version information and exit\n"
 183 "  -d, --daemonize   become a daemon\n"
 184 #ifdef _WIN32
 185 "  -s, --service     service commands: install, uninstall\n"
 186 #endif
 187 "  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\"\n"
 188 "                    to list available RPCs)\n"
 189 "  -h, --help        display this help and exit\n"
 190 "\n"
 191 "Report bugs to <mdroth@linux.vnet.ibm.com>\n"
 192     , cmd, QEMU_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT,
 193 #ifdef CONFIG_FSFREEZE
 194     QGA_FSFREEZE_HOOK_DEFAULT,
 195 #endif
 196     QGA_STATEDIR_DEFAULT);
 197 }
 198
 199 static const char *ga_log_level_str(GLogLevelFlags level)
 200 {
 201     switch (level & G_LOG_LEVEL_MASK) {
 202         case G_LOG_LEVEL_ERROR:
 203             return "error";
 204         case G_LOG_LEVEL_CRITICAL:
 205             return "critical";
 206         case G_LOG_LEVEL_WARNING:
 207             return "warning";
 208         case G_LOG_LEVEL_MESSAGE:
 209             return "message";
 210         case G_LOG_LEVEL_INFO:
 211             return "info";
 212         case G_LOG_LEVEL_DEBUG:
 213             return "debug";
 214         default:
 215             return "user";
 216     }
 217 }
 218
 219 bool ga_logging_enabled(GAState *s)
 220 {
 221     return s->logging_enabled;
 222 }
 223
 224 void ga_disable_logging(GAState *s)
 225 {
 226     s->logging_enabled = false;
 227 }
 228
 229 void ga_enable_logging(GAState *s)
 230 {
 231     s->logging_enabled = true;
 232 }
 233
 234 static void ga_log(const gchar *domain, GLogLevelFlags level,
 235                    const gchar *msg, gpointer opaque)
 236 {
 237     GAState *s = opaque;
 238     GTimeVal time;
 239     const char *level_str = ga_log_level_str(level);
 240
 241     if (!ga_logging_enabled(s)) {
 242         return;
 243     }
 244
 245     level &= G_LOG_LEVEL_MASK;
 246 #ifndef _WIN32
 247     if (domain && strcmp(domain, "syslog") == 0) {
 248         syslog(LOG_INFO, "%s: %s", level_str, msg);
 249     } else if (level & s->log_level) {
 250 #else
 251     if (level & s->log_level) {
 252 #endif
 253         g_get_current_time(&time);
 254         fprintf(s->log_file,
 255                 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
 256         fflush(s->log_file);
 257     }
 258 }
 259
 260 void ga_set_response_delimited(GAState *s)
 261 {
 262     s->delimit_response = true;
 263 }
 264
 265 static FILE *ga_open_logfile(const char *logfile)
 266 {
 267     FILE *f;
 268
 269     f = fopen(logfile, "a");
 270     if (!f) {
 271         return NULL;
 272     }
 273
 274     qemu_set_cloexec(fileno(f));
 275     return f;
 276 }
 277
 278 #ifndef _WIN32
 279 static bool ga_open_pidfile(const char *pidfile)
 280 {
 281     int pidfd;
 282     char pidstr[32];
 283
 284     pidfd = qemu_open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
 285     if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) {
 286         g_critical("Cannot lock pid file, %s", strerror(errno));
 287         if (pidfd != -1) {
 288             close(pidfd);
 289         }
 290         return false;
 291     }
 292
 293     if (ftruncate(pidfd, 0)) {
 294         g_critical("Failed to truncate pid file");
 295         goto fail;
 296     }
 297     snprintf(pidstr, sizeof(pidstr), "%d\n", getpid());
 298     if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
 299         g_critical("Failed to write pid file");
 300         goto fail;
 301     }
 302
 303     /* keep pidfile open & locked forever */
 304     return true;
 305
 306 fail:
 307     unlink(pidfile);
 308     close(pidfd);
 309     return false;
 310 }
 311 #else /* _WIN32 */
 312 static bool ga_open_pidfile(const char *pidfile)
 313 {
 314     return true;
 315 }
 316 #endif
 317
 318 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
 319 {
 320     return strcmp(str1, str2);
 321 }
 322
 323 /* disable commands that aren't safe for fsfreeze */
 324 static void ga_disable_non_whitelisted(void)
 325 {
 326     char **list_head, **list;
 327     bool whitelisted;
 328     int i;
 329
 330     list_head = list = qmp_get_command_list();
 331     while (*list != NULL) {
 332         whitelisted = false;
 333         i = 0;
 334         while (ga_freeze_whitelist[i] != NULL) {
 335             if (strcmp(*list, ga_freeze_whitelist[i]) == 0) {
 336                 whitelisted = true;
 337             }
 338             i++;
 339         }
 340         if (!whitelisted) {
 341             g_debug("disabling command: %s", *list);
 342             qmp_disable_command(*list);
 343         }
 344         g_free(*list);
 345         list++;
 346     }
 347     g_free(list_head);
 348 }
 349
 350 /* [re-]enable all commands, except those explicitly blacklisted by user */
 351 static void ga_enable_non_blacklisted(GList *blacklist)
 352 {
 353     char **list_head, **list;
 354
 355     list_head = list = qmp_get_command_list();
 356     while (*list != NULL) {
 357         if (g_list_find_custom(blacklist, *list, ga_strcmp) == NULL &&
 358             !qmp_command_is_enabled(*list)) {
 359             g_debug("enabling command: %s", *list);
 360             qmp_enable_command(*list);
 361         }
 362         g_free(*list);
 363         list++;
 364     }
 365     g_free(list_head);
 366 }
 367
 368 static bool ga_create_file(const char *path)
 369 {
 370     int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
 371     if (fd == -1) {
 372         g_warning("unable to open/create file %s: %s", path, strerror(errno));
 373         return false;
 374     }
 375     close(fd);
 376     return true;
 377 }
 378
 379 static bool ga_delete_file(const char *path)
 380 {
 381     int ret = unlink(path);
 382     if (ret == -1) {
 383         g_warning("unable to delete file: %s: %s", path, strerror(errno));
 384         return false;
 385     }
 386
 387     return true;
 388 }
 389
 390 bool ga_is_frozen(GAState *s)
 391 {
 392     return s->frozen;
 393 }
 394
 395 void ga_set_frozen(GAState *s)
 396 {
 397     if (ga_is_frozen(s)) {
 398         return;
 399     }
 400     /* disable all non-whitelisted (for frozen state) commands */
 401     ga_disable_non_whitelisted();
 402     g_warning("disabling logging due to filesystem freeze");
 403     ga_disable_logging(s);
 404     s->frozen = true;
 405     if (!ga_create_file(s->state_filepath_isfrozen)) {
 406         g_warning("unable to create %s, fsfreeze may not function properly",
 407                   s->state_filepath_isfrozen);
 408     }
 409 }
 410
 411 void ga_unset_frozen(GAState *s)
 412 {
 413     if (!ga_is_frozen(s)) {
 414         return;
 415     }
 416
 417     /* if we delayed creation/opening of pid/log files due to being
 418      * in a frozen state at start up, do it now
 419      */
 420     if (s->deferred_options.log_filepath) {
 421         s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
 422         if (!s->log_file) {
 423             s->log_file = stderr;
 424         }
 425         s->deferred_options.log_filepath = NULL;
 426     }
 427     ga_enable_logging(s);
 428     g_warning("logging re-enabled due to filesystem unfreeze");
 429     if (s->deferred_options.pid_filepath) {
 430         if (!ga_open_pidfile(s->deferred_options.pid_filepath)) {
 431             g_warning("failed to create/open pid file");
 432         }
 433         s->deferred_options.pid_filepath = NULL;
 434     }
 435
 436     /* enable all disabled, non-blacklisted commands */
 437     ga_enable_non_blacklisted(s->blacklist);
 438     s->frozen = false;
 439     if (!ga_delete_file(s->state_filepath_isfrozen)) {
 440         g_warning("unable to delete %s, fsfreeze may not function properly",
 441                   s->state_filepath_isfrozen);
 442     }
 443 }
 444
 445 #ifdef CONFIG_FSFREEZE
 446 const char *ga_fsfreeze_hook(GAState *s)
 447 {
 448     return s->fsfreeze_hook;
 449 }
 450 #endif
 451
 452 static void become_daemon(const char *pidfile)
 453 {
 454 #ifndef _WIN32
 455     pid_t pid, sid;
 456
 457     pid = fork();
 458     if (pid < 0) {
 459         exit(EXIT_FAILURE);
 460     }
 461     if (pid > 0) {
 462         exit(EXIT_SUCCESS);
 463     }
 464
 465     if (pidfile) {
 466         if (!ga_open_pidfile(pidfile)) {
 467             g_critical("failed to create pidfile");
 468             exit(EXIT_FAILURE);
 469         }
 470     }
 471
 472     umask(0);
 473     sid = setsid();
 474     if (sid < 0) {
 475         goto fail;
 476     }
 477     if ((chdir("/")) < 0) {
 478         goto fail;
 479     }
 480
 481     reopen_fd_to_null(STDIN_FILENO);
 482     reopen_fd_to_null(STDOUT_FILENO);
 483     reopen_fd_to_null(STDERR_FILENO);
 484     return;
 485
 486 fail:
 487     if (pidfile) {
 488         unlink(pidfile);
 489     }
 490     g_critical("failed to daemonize");
 491     exit(EXIT_FAILURE);
 492 #endif
 493 }
 494
 495 static int send_response(GAState *s, QObject *payload)
 496 {
 497     const char *buf;
 498     QString *payload_qstr, *response_qstr;
 499     GIOStatus status;
 500
 501     g_assert(payload && s->channel);
 502
 503     payload_qstr = qobject_to_json(payload);
 504     if (!payload_qstr) {
 505         return -EINVAL;
 506     }
 507
 508     if (s->delimit_response) {
 509         s->delimit_response = false;
 510         response_qstr = qstring_new();
 511         qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
 512         qstring_append(response_qstr, qstring_get_str(payload_qstr));
 513         QDECREF(payload_qstr);
 514     } else {
 515         response_qstr = payload_qstr;
 516     }
 517
 518     qstring_append_chr(response_qstr, '\n');
 519     buf = qstring_get_str(response_qstr);
 520     status = ga_channel_write_all(s->channel, buf, strlen(buf));
 521     QDECREF(response_qstr);
 522     if (status != G_IO_STATUS_NORMAL) {
 523         return -EIO;
 524     }
 525
 526     return 0;
 527 }
 528
 529 static void process_command(GAState *s, QDict *req)
 530 {
 531     QObject *rsp = NULL;
 532     int ret;
 533
 534     g_assert(req);
 535     g_debug("processing command");
 536     rsp = qmp_dispatch(QOBJECT(req));
 537     if (rsp) {
 538         ret = send_response(s, rsp);
 539         if (ret) {
 540             g_warning("error sending response: %s", strerror(ret));
 541         }
 542         qobject_decref(rsp);
 543     }
 544 }
 545
 546 /* handle requests/control events coming in over the channel */
 547 static void process_event(JSONMessageParser *parser, QList *tokens)
 548 {
 549     GAState *s = container_of(parser, GAState, parser);
 550     QObject *obj;
 551     QDict *qdict;
 552     Error *err = NULL;
 553     int ret;
 554
 555     g_assert(s && parser);
 556
 557     g_debug("process_event: called");
 558     obj = json_parser_parse_err(tokens, NULL, &err);
 559     if (err || !obj || qobject_type(obj) != QTYPE_QDICT) {
 560         qobject_decref(obj);
 561         qdict = qdict_new();
 562         if (!err) {
 563             g_warning("failed to parse event: unknown error");
 564             error_set(&err, QERR_JSON_PARSING);
 565         } else {
 566             g_warning("failed to parse event: %s", error_get_pretty(err));
 567         }
 568         qdict_put_obj(qdict, "error", qmp_build_error_object(err));
 569         error_free(err);
 570     } else {
 571         qdict = qobject_to_qdict(obj);
 572     }
 573
 574     g_assert(qdict);
 575
 576     /* handle host->guest commands */
 577     if (qdict_haskey(qdict, "execute")) {
 578         process_command(s, qdict);
 579     } else {
 580         if (!qdict_haskey(qdict, "error")) {
 581             QDECREF(qdict);
 582             qdict = qdict_new();
 583             g_warning("unrecognized payload format");
 584             error_set(&err, QERR_UNSUPPORTED);
 585             qdict_put_obj(qdict, "error", qmp_build_error_object(err));
 586             error_free(err);
 587         }
 588         ret = send_response(s, QOBJECT(qdict));
 589         if (ret) {
 590             g_warning("error sending error response: %s", strerror(ret));
 591         }
 592     }
 593
 594     QDECREF(qdict);
 595 }
 596
 597 /* false return signals GAChannel to close the current client connection */
 598 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 599 {
 600     GAState *s = data;
 601     gchar buf[QGA_READ_COUNT_DEFAULT+1];
 602     gsize count;
 603     GError *err = NULL;
 604     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 605     if (err != NULL) {
 606         g_warning("error reading channel: %s", err->message);
 607         g_error_free(err);
 608         return false;
 609     }
 610     switch (status) {
 611     case G_IO_STATUS_ERROR:
 612         g_warning("error reading channel");
 613         return false;
 614     case G_IO_STATUS_NORMAL:
 615         buf[count] = 0;
 616         g_debug("read data, count: %d, data: %s", (int)count, buf);
 617         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 618         break;
 619     case G_IO_STATUS_EOF:
 620         g_debug("received EOF");
 621         if (!s->virtio) {
 622             return false;
 623         }
 624         /* fall through */
 625     case G_IO_STATUS_AGAIN:
 626         /* virtio causes us to spin here when no process is attached to
 627          * host-side chardev. sleep a bit to mitigate this
 628          */
 629         if (s->virtio) {
 630             usleep(100*1000);
 631         }
 632         return true;
 633     default:
 634         g_warning("unknown channel read status, closing");
 635         return false;
 636     }
 637     return true;
 638 }
 639
 640 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
 641 {
 642     GAChannelMethod channel_method;
 643
 644     if (method == NULL) {
 645         method = "virtio-serial";
 646     }
 647
 648     if (path == NULL) {
 649         if (strcmp(method, "virtio-serial") != 0) {
 650             g_critical("must specify a path for this channel");
 651             return false;
 652         }
 653         /* try the default path for the virtio-serial port */
 654         path = QGA_VIRTIO_PATH_DEFAULT;
 655     }
 656
 657     if (strcmp(method, "virtio-serial") == 0) {
 658         s->virtio = true; /* virtio requires special handling in some cases */
 659         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 660     } else if (strcmp(method, "isa-serial") == 0) {
 661         channel_method = GA_CHANNEL_ISA_SERIAL;
 662     } else if (strcmp(method, "unix-listen") == 0) {
 663         channel_method = GA_CHANNEL_UNIX_LISTEN;
 664     } else {
 665         g_critical("unsupported channel method/type: %s", method);
 666         return false;
 667     }
 668
 669     s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
 670     if (!s->channel) {
 671         g_critical("failed to create guest agent channel");
 672         return false;
 673     }
 674
 675     return true;
 676 }
 677
 678 #ifdef _WIN32
 679 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 680                                   LPVOID ctx)
 681 {
 682     DWORD ret = NO_ERROR;
 683     GAService *service = &ga_state->service;
 684
 685     switch (ctrl)
 686     {
 687         case SERVICE_CONTROL_STOP:
 688         case SERVICE_CONTROL_SHUTDOWN:
 689             quit_handler(SIGTERM);
 690             service->status.dwCurrentState = SERVICE_STOP_PENDING;
 691             SetServiceStatus(service->status_handle, &service->status);
 692             break;
 693
 694         default:
 695             ret = ERROR_CALL_NOT_IMPLEMENTED;
 696     }
 697     return ret;
 698 }
 699
 700 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 701 {
 702     GAService *service = &ga_state->service;
 703
 704     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 705         service_ctrl_handler, NULL);
 706
 707     if (service->status_handle == 0) {
 708         g_critical("Failed to register extended requests function!\n");
 709         return;
 710     }
 711
 712     service->status.dwServiceType = SERVICE_WIN32;
 713     service->status.dwCurrentState = SERVICE_RUNNING;
 714     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 715     service->status.dwWin32ExitCode = NO_ERROR;
 716     service->status.dwServiceSpecificExitCode = NO_ERROR;
 717     service->status.dwCheckPoint = 0;
 718     service->status.dwWaitHint = 0;
 719     SetServiceStatus(service->status_handle, &service->status);
 720
 721     g_main_loop_run(ga_state->main_loop);
 722
 723     service->status.dwCurrentState = SERVICE_STOPPED;
 724     SetServiceStatus(service->status_handle, &service->status);
 725 }
 726 #endif
 727
 728 int main(int argc, char **argv)
 729 {
 730     const char *sopt = "hVvdm:p:l:f:F::b:s:t:";
 731     const char *method = NULL, *path = NULL;
 732     const char *log_filepath = NULL;
 733     const char *pid_filepath = QGA_PIDFILE_DEFAULT;
 734 #ifdef CONFIG_FSFREEZE
 735     const char *fsfreeze_hook = NULL;
 736 #endif
 737     const char *state_dir = QGA_STATEDIR_DEFAULT;
 738 #ifdef _WIN32
 739     const char *service = NULL;
 740 #endif
 741     const struct option lopt[] = {
 742         { "help", 0, NULL, 'h' },
 743         { "version", 0, NULL, 'V' },
 744         { "logfile", 1, NULL, 'l' },
 745         { "pidfile", 1, NULL, 'f' },
 746 #ifdef CONFIG_FSFREEZE
 747         { "fsfreeze-hook", 2, NULL, 'F' },
 748 #endif
 749         { "verbose", 0, NULL, 'v' },
 750         { "method", 1, NULL, 'm' },
 751         { "path", 1, NULL, 'p' },
 752         { "daemonize", 0, NULL, 'd' },
 753         { "blacklist", 1, NULL, 'b' },
 754 #ifdef _WIN32
 755         { "service", 1, NULL, 's' },
 756 #endif
 757         { "statedir", 1, NULL, 't' },
 758         { NULL, 0, NULL, 0 }
 759     };
 760     int opt_ind = 0, ch, daemonize = 0, i, j, len;
 761     GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
 762     GList *blacklist = NULL;
 763     GAState *s;
 764
 765     module_call_init(MODULE_INIT_QAPI);
 766
 767     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 768         switch (ch) {
 769         case 'm':
 770             method = optarg;
 771             break;
 772         case 'p':
 773             path = optarg;
 774             break;
 775         case 'l':
 776             log_filepath = optarg;
 777             break;
 778         case 'f':
 779             pid_filepath = optarg;
 780             break;
 781 #ifdef CONFIG_FSFREEZE
 782         case 'F':
 783             fsfreeze_hook = optarg ? optarg : QGA_FSFREEZE_HOOK_DEFAULT;
 784             break;
 785 #endif
 786         case 't':
 787              state_dir = optarg;
 788              break;
 789         case 'v':
 790             /* enable all log levels */
 791             log_level = G_LOG_LEVEL_MASK;
 792             break;
 793         case 'V':
 794             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
 795             return 0;
 796         case 'd':
 797             daemonize = 1;
 798             break;
 799         case 'b': {
 800             char **list_head, **list;
 801             if (is_help_option(optarg)) {
 802                 list_head = list = qmp_get_command_list();
 803                 while (*list != NULL) {
 804                     printf("%s\n", *list);
 805                     g_free(*list);
 806                     list++;
 807                 }
 808                 g_free(list_head);
 809                 return 0;
 810             }
 811             for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
 812                 if (optarg[i] == ',') {
 813                     optarg[i] = 0;
 814                     blacklist = g_list_append(blacklist, &optarg[j]);
 815                     j = i + 1;
 816                 }
 817             }
 818             if (j < i) {
 819                 blacklist = g_list_append(blacklist, &optarg[j]);
 820             }
 821             break;
 822         }
 823 #ifdef _WIN32
 824         case 's':
 825             service = optarg;
 826             if (strcmp(service, "install") == 0) {
 827                 return ga_install_service(path, log_filepath);
 828             } else if (strcmp(service, "uninstall") == 0) {
 829                 return ga_uninstall_service();
 830             } else {
 831                 printf("Unknown service command.\n");
 832                 return EXIT_FAILURE;
 833             }
 834             break;
 835 #endif
 836         case 'h':
 837             usage(argv[0]);
 838             return 0;
 839         case '?':
 840             g_print("Unknown option, try '%s --help' for more information.\n",
 841                     argv[0]);
 842             return EXIT_FAILURE;
 843         }
 844     }
 845
 846     s = g_malloc0(sizeof(GAState));
 847     s->log_level = log_level;
 848     s->log_file = stderr;
 849 #ifdef CONFIG_FSFREEZE
 850     s->fsfreeze_hook = fsfreeze_hook;
 851 #endif
 852     g_log_set_default_handler(ga_log, s);
 853     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
 854     ga_enable_logging(s);
 855     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
 856                                                  state_dir);
 857     s->frozen = false;
 858 #ifndef _WIN32
 859     /* check if a previous instance of qemu-ga exited with filesystems' state
 860      * marked as frozen. this could be a stale value (a non-qemu-ga process
 861      * or reboot may have since unfrozen them), but better to require an
 862      * uneeded unfreeze than to risk hanging on start-up
 863      */
 864     struct stat st;
 865     if (stat(s->state_filepath_isfrozen, &st) == -1) {
 866         /* it's okay if the file doesn't exist, but if we can't access for
 867          * some other reason, such as permissions, there's a configuration
 868          * that needs to be addressed. so just bail now before we get into
 869          * more trouble later
 870          */
 871         if (errno != ENOENT) {
 872             g_critical("unable to access state file at path %s: %s",
 873                        s->state_filepath_isfrozen, strerror(errno));
 874             return EXIT_FAILURE;
 875         }
 876     } else {
 877         g_warning("previous instance appears to have exited with frozen"
 878                   " filesystems. deferring logging/pidfile creation and"
 879                   " disabling non-fsfreeze-safe commands until"
 880                   " guest-fsfreeze-thaw is issued, or filesystems are"
 881                   " manually unfrozen and the file %s is removed",
 882                   s->state_filepath_isfrozen);
 883         s->frozen = true;
 884     }
 885 #endif
 886
 887     if (ga_is_frozen(s)) {
 888         if (daemonize) {
 889             /* delay opening/locking of pidfile till filesystem are unfrozen */
 890             s->deferred_options.pid_filepath = pid_filepath;
 891             become_daemon(NULL);
 892         }
 893         if (log_filepath) {
 894             /* delay opening the log file till filesystems are unfrozen */
 895             s->deferred_options.log_filepath = log_filepath;
 896         }
 897         ga_disable_logging(s);
 898         ga_disable_non_whitelisted();
 899     } else {
 900         if (daemonize) {
 901             become_daemon(pid_filepath);
 902         }
 903         if (log_filepath) {
 904             FILE *log_file = ga_open_logfile(log_filepath);
 905             if (!log_file) {
 906                 g_critical("unable to open specified log file: %s",
 907                            strerror(errno));
 908                 goto out_bad;
 909             }
 910             s->log_file = log_file;
 911         }
 912     }
 913
 914     if (blacklist) {
 915         s->blacklist = blacklist;
 916         do {
 917             g_debug("disabling command: %s", (char *)blacklist->data);
 918             qmp_disable_command(blacklist->data);
 919             blacklist = g_list_next(blacklist);
 920         } while (blacklist);
 921     }
 922     s->command_state = ga_command_state_new();
 923     ga_command_state_init(s, s->command_state);
 924     ga_command_state_init_all(s->command_state);
 925     json_message_parser_init(&s->parser, process_event);
 926     ga_state = s;
 927 #ifndef _WIN32
 928     if (!register_signal_handlers()) {
 929         g_critical("failed to register signal handlers");
 930         goto out_bad;
 931     }
 932 #endif
 933
 934     s->main_loop = g_main_loop_new(NULL, false);
 935     if (!channel_init(ga_state, method, path)) {
 936         g_critical("failed to initialize guest agent channel");
 937         goto out_bad;
 938     }
 939 #ifndef _WIN32
 940     g_main_loop_run(ga_state->main_loop);
 941 #else
 942     if (daemonize) {
 943         SERVICE_TABLE_ENTRY service_table[] = {
 944             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
 945         StartServiceCtrlDispatcher(service_table);
 946     } else {
 947         g_main_loop_run(ga_state->main_loop);
 948     }
 949 #endif
 950
 951     ga_command_state_cleanup_all(ga_state->command_state);
 952     ga_channel_free(ga_state->channel);
 953
 954     if (daemonize) {
 955         unlink(pid_filepath);
 956     }
 957     return 0;
 958
 959 out_bad:
 960     if (daemonize) {
 961         unlink(pid_filepath);
 962     }
 963     return EXIT_FAILURE;
 964 }