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