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 #ifndef _WIN32
 265 static bool ga_open_pidfile(const char *pidfile)
 266 {
 267     int pidfd;
 268     char pidstr[32];
 269
 270     pidfd = qemu_open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
 271     if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) {
 272         g_critical("Cannot lock pid file, %s", strerror(errno));
 273         if (pidfd != -1) {
 274             close(pidfd);
 275         }
 276         return false;
 277     }
 278
 279     if (ftruncate(pidfd, 0) || lseek(pidfd, 0, SEEK_SET)) {
 280         g_critical("Failed to truncate pid file");
 281         goto fail;
 282     }
 283     snprintf(pidstr, sizeof(pidstr), "%d\n", getpid());
 284     if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
 285         g_critical("Failed to write pid file");
 286         goto fail;
 287     }
 288
 289     return true;
 290
 291 fail:
 292     unlink(pidfile);
 293     return false;
 294 }
 295 #else /* _WIN32 */
 296 static bool ga_open_pidfile(const char *pidfile)
 297 {
 298     return true;
 299 }
 300 #endif
 301
 302 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
 303 {
 304     return strcmp(str1, str2);
 305 }
 306
 307 /* disable commands that aren't safe for fsfreeze */
 308 static void ga_disable_non_whitelisted(void)
 309 {
 310     char **list_head, **list;
 311     bool whitelisted;
 312     int i;
 313
 314     list_head = list = qmp_get_command_list();
 315     while (*list != NULL) {
 316         whitelisted = false;
 317         i = 0;
 318         while (ga_freeze_whitelist[i] != NULL) {
 319             if (strcmp(*list, ga_freeze_whitelist[i]) == 0) {
 320                 whitelisted = true;
 321             }
 322             i++;
 323         }
 324         if (!whitelisted) {
 325             g_debug("disabling command: %s", *list);
 326             qmp_disable_command(*list);
 327         }
 328         g_free(*list);
 329         list++;
 330     }
 331     g_free(list_head);
 332 }
 333
 334 /* [re-]enable all commands, except those explicitly blacklisted by user */
 335 static void ga_enable_non_blacklisted(GList *blacklist)
 336 {
 337     char **list_head, **list;
 338
 339     list_head = list = qmp_get_command_list();
 340     while (*list != NULL) {
 341         if (g_list_find_custom(blacklist, *list, ga_strcmp) == NULL &&
 342             !qmp_command_is_enabled(*list)) {
 343             g_debug("enabling command: %s", *list);
 344             qmp_enable_command(*list);
 345         }
 346         g_free(*list);
 347         list++;
 348     }
 349     g_free(list_head);
 350 }
 351
 352 static bool ga_create_file(const char *path)
 353 {
 354     int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
 355     if (fd == -1) {
 356         g_warning("unable to open/create file %s: %s", path, strerror(errno));
 357         return false;
 358     }
 359     close(fd);
 360     return true;
 361 }
 362
 363 static bool ga_delete_file(const char *path)
 364 {
 365     int ret = unlink(path);
 366     if (ret == -1) {
 367         g_warning("unable to delete file: %s: %s", path, strerror(errno));
 368         return false;
 369     }
 370
 371     return true;
 372 }
 373
 374 bool ga_is_frozen(GAState *s)
 375 {
 376     return s->frozen;
 377 }
 378
 379 void ga_set_frozen(GAState *s)
 380 {
 381     if (ga_is_frozen(s)) {
 382         return;
 383     }
 384     /* disable all non-whitelisted (for frozen state) commands */
 385     ga_disable_non_whitelisted();
 386     g_warning("disabling logging due to filesystem freeze");
 387     ga_disable_logging(s);
 388     s->frozen = true;
 389     if (!ga_create_file(s->state_filepath_isfrozen)) {
 390         g_warning("unable to create %s, fsfreeze may not function properly",
 391                   s->state_filepath_isfrozen);
 392     }
 393 }
 394
 395 void ga_unset_frozen(GAState *s)
 396 {
 397     if (!ga_is_frozen(s)) {
 398         return;
 399     }
 400
 401     /* if we delayed creation/opening of pid/log files due to being
 402      * in a frozen state at start up, do it now
 403      */
 404     if (s->deferred_options.log_filepath) {
 405         s->log_file = fopen(s->deferred_options.log_filepath, "a");
 406         if (!s->log_file) {
 407             s->log_file = stderr;
 408         }
 409         s->deferred_options.log_filepath = NULL;
 410     }
 411     ga_enable_logging(s);
 412     g_warning("logging re-enabled due to filesystem unfreeze");
 413     if (s->deferred_options.pid_filepath) {
 414         if (!ga_open_pidfile(s->deferred_options.pid_filepath)) {
 415             g_warning("failed to create/open pid file");
 416         }
 417         s->deferred_options.pid_filepath = NULL;
 418     }
 419
 420     /* enable all disabled, non-blacklisted commands */
 421     ga_enable_non_blacklisted(s->blacklist);
 422     s->frozen = false;
 423     if (!ga_delete_file(s->state_filepath_isfrozen)) {
 424         g_warning("unable to delete %s, fsfreeze may not function properly",
 425                   s->state_filepath_isfrozen);
 426     }
 427 }
 428
 429 #ifdef CONFIG_FSFREEZE
 430 const char *ga_fsfreeze_hook(GAState *s)
 431 {
 432     return s->fsfreeze_hook;
 433 }
 434 #endif
 435
 436 static void become_daemon(const char *pidfile)
 437 {
 438 #ifndef _WIN32
 439     pid_t pid, sid;
 440
 441     pid = fork();
 442     if (pid < 0) {
 443         exit(EXIT_FAILURE);
 444     }
 445     if (pid > 0) {
 446         exit(EXIT_SUCCESS);
 447     }
 448
 449     if (pidfile) {
 450         if (!ga_open_pidfile(pidfile)) {
 451             g_critical("failed to create pidfile");
 452             exit(EXIT_FAILURE);
 453         }
 454     }
 455
 456     umask(0);
 457     sid = setsid();
 458     if (sid < 0) {
 459         goto fail;
 460     }
 461     if ((chdir("/")) < 0) {
 462         goto fail;
 463     }
 464
 465     reopen_fd_to_null(STDIN_FILENO);
 466     reopen_fd_to_null(STDOUT_FILENO);
 467     reopen_fd_to_null(STDERR_FILENO);
 468     return;
 469
 470 fail:
 471     if (pidfile) {
 472         unlink(pidfile);
 473     }
 474     g_critical("failed to daemonize");
 475     exit(EXIT_FAILURE);
 476 #endif
 477 }
 478
 479 static int send_response(GAState *s, QObject *payload)
 480 {
 481     const char *buf;
 482     QString *payload_qstr, *response_qstr;
 483     GIOStatus status;
 484
 485     g_assert(payload && s->channel);
 486
 487     payload_qstr = qobject_to_json(payload);
 488     if (!payload_qstr) {
 489         return -EINVAL;
 490     }
 491
 492     if (s->delimit_response) {
 493         s->delimit_response = false;
 494         response_qstr = qstring_new();
 495         qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
 496         qstring_append(response_qstr, qstring_get_str(payload_qstr));
 497         QDECREF(payload_qstr);
 498     } else {
 499         response_qstr = payload_qstr;
 500     }
 501
 502     qstring_append_chr(response_qstr, '\n');
 503     buf = qstring_get_str(response_qstr);
 504     status = ga_channel_write_all(s->channel, buf, strlen(buf));
 505     QDECREF(response_qstr);
 506     if (status != G_IO_STATUS_NORMAL) {
 507         return -EIO;
 508     }
 509
 510     return 0;
 511 }
 512
 513 static void process_command(GAState *s, QDict *req)
 514 {
 515     QObject *rsp = NULL;
 516     int ret;
 517
 518     g_assert(req);
 519     g_debug("processing command");
 520     rsp = qmp_dispatch(QOBJECT(req));
 521     if (rsp) {
 522         ret = send_response(s, rsp);
 523         if (ret) {
 524             g_warning("error sending response: %s", strerror(ret));
 525         }
 526         qobject_decref(rsp);
 527     }
 528 }
 529
 530 /* handle requests/control events coming in over the channel */
 531 static void process_event(JSONMessageParser *parser, QList *tokens)
 532 {
 533     GAState *s = container_of(parser, GAState, parser);
 534     QObject *obj;
 535     QDict *qdict;
 536     Error *err = NULL;
 537     int ret;
 538
 539     g_assert(s && parser);
 540
 541     g_debug("process_event: called");
 542     obj = json_parser_parse_err(tokens, NULL, &err);
 543     if (err || !obj || qobject_type(obj) != QTYPE_QDICT) {
 544         qobject_decref(obj);
 545         qdict = qdict_new();
 546         if (!err) {
 547             g_warning("failed to parse event: unknown error");
 548             error_set(&err, QERR_JSON_PARSING);
 549         } else {
 550             g_warning("failed to parse event: %s", error_get_pretty(err));
 551         }
 552         qdict_put_obj(qdict, "error", qmp_build_error_object(err));
 553         error_free(err);
 554     } else {
 555         qdict = qobject_to_qdict(obj);
 556     }
 557
 558     g_assert(qdict);
 559
 560     /* handle host->guest commands */
 561     if (qdict_haskey(qdict, "execute")) {
 562         process_command(s, qdict);
 563     } else {
 564         if (!qdict_haskey(qdict, "error")) {
 565             QDECREF(qdict);
 566             qdict = qdict_new();
 567             g_warning("unrecognized payload format");
 568             error_set(&err, QERR_UNSUPPORTED);
 569             qdict_put_obj(qdict, "error", qmp_build_error_object(err));
 570             error_free(err);
 571         }
 572         ret = send_response(s, QOBJECT(qdict));
 573         if (ret) {
 574             g_warning("error sending error response: %s", strerror(ret));
 575         }
 576     }
 577
 578     QDECREF(qdict);
 579 }
 580
 581 /* false return signals GAChannel to close the current client connection */
 582 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 583 {
 584     GAState *s = data;
 585     gchar buf[QGA_READ_COUNT_DEFAULT+1];
 586     gsize count;
 587     GError *err = NULL;
 588     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 589     if (err != NULL) {
 590         g_warning("error reading channel: %s", err->message);
 591         g_error_free(err);
 592         return false;
 593     }
 594     switch (status) {
 595     case G_IO_STATUS_ERROR:
 596         g_warning("error reading channel");
 597         return false;
 598     case G_IO_STATUS_NORMAL:
 599         buf[count] = 0;
 600         g_debug("read data, count: %d, data: %s", (int)count, buf);
 601         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 602         break;
 603     case G_IO_STATUS_EOF:
 604         g_debug("received EOF");
 605         if (!s->virtio) {
 606             return false;
 607         }
 608     case G_IO_STATUS_AGAIN:
 609         /* virtio causes us to spin here when no process is attached to
 610          * host-side chardev. sleep a bit to mitigate this
 611          */
 612         if (s->virtio) {
 613             usleep(100*1000);
 614         }
 615         return true;
 616     default:
 617         g_warning("unknown channel read status, closing");
 618         return false;
 619     }
 620     return true;
 621 }
 622
 623 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
 624 {
 625     GAChannelMethod channel_method;
 626
 627     if (method == NULL) {
 628         method = "virtio-serial";
 629     }
 630
 631     if (path == NULL) {
 632         if (strcmp(method, "virtio-serial") != 0) {
 633             g_critical("must specify a path for this channel");
 634             return false;
 635         }
 636         /* try the default path for the virtio-serial port */
 637         path = QGA_VIRTIO_PATH_DEFAULT;
 638     }
 639
 640     if (strcmp(method, "virtio-serial") == 0) {
 641         s->virtio = true; /* virtio requires special handling in some cases */
 642         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 643     } else if (strcmp(method, "isa-serial") == 0) {
 644         channel_method = GA_CHANNEL_ISA_SERIAL;
 645     } else if (strcmp(method, "unix-listen") == 0) {
 646         channel_method = GA_CHANNEL_UNIX_LISTEN;
 647     } else {
 648         g_critical("unsupported channel method/type: %s", method);
 649         return false;
 650     }
 651
 652     s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
 653     if (!s->channel) {
 654         g_critical("failed to create guest agent channel");
 655         return false;
 656     }
 657
 658     return true;
 659 }
 660
 661 #ifdef _WIN32
 662 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 663                                   LPVOID ctx)
 664 {
 665     DWORD ret = NO_ERROR;
 666     GAService *service = &ga_state->service;
 667
 668     switch (ctrl)
 669     {
 670         case SERVICE_CONTROL_STOP:
 671         case SERVICE_CONTROL_SHUTDOWN:
 672             quit_handler(SIGTERM);
 673             service->status.dwCurrentState = SERVICE_STOP_PENDING;
 674             SetServiceStatus(service->status_handle, &service->status);
 675             break;
 676
 677         default:
 678             ret = ERROR_CALL_NOT_IMPLEMENTED;
 679     }
 680     return ret;
 681 }
 682
 683 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 684 {
 685     GAService *service = &ga_state->service;
 686
 687     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 688         service_ctrl_handler, NULL);
 689
 690     if (service->status_handle == 0) {
 691         g_critical("Failed to register extended requests function!\n");
 692         return;
 693     }
 694
 695     service->status.dwServiceType = SERVICE_WIN32;
 696     service->status.dwCurrentState = SERVICE_RUNNING;
 697     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 698     service->status.dwWin32ExitCode = NO_ERROR;
 699     service->status.dwServiceSpecificExitCode = NO_ERROR;
 700     service->status.dwCheckPoint = 0;
 701     service->status.dwWaitHint = 0;
 702     SetServiceStatus(service->status_handle, &service->status);
 703
 704     g_main_loop_run(ga_state->main_loop);
 705
 706     service->status.dwCurrentState = SERVICE_STOPPED;
 707     SetServiceStatus(service->status_handle, &service->status);
 708 }
 709 #endif
 710
 711 int main(int argc, char **argv)
 712 {
 713     const char *sopt = "hVvdm:p:l:f:F::b:s:t:";
 714     const char *method = NULL, *path = NULL;
 715     const char *log_filepath = NULL;
 716     const char *pid_filepath = QGA_PIDFILE_DEFAULT;
 717 #ifdef CONFIG_FSFREEZE
 718     const char *fsfreeze_hook = NULL;
 719 #endif
 720     const char *state_dir = QGA_STATEDIR_DEFAULT;
 721 #ifdef _WIN32
 722     const char *service = NULL;
 723 #endif
 724     const struct option lopt[] = {
 725         { "help", 0, NULL, 'h' },
 726         { "version", 0, NULL, 'V' },
 727         { "logfile", 1, NULL, 'l' },
 728         { "pidfile", 1, NULL, 'f' },
 729 #ifdef CONFIG_FSFREEZE
 730         { "fsfreeze-hook", 2, NULL, 'F' },
 731 #endif
 732         { "verbose", 0, NULL, 'v' },
 733         { "method", 1, NULL, 'm' },
 734         { "path", 1, NULL, 'p' },
 735         { "daemonize", 0, NULL, 'd' },
 736         { "blacklist", 1, NULL, 'b' },
 737 #ifdef _WIN32
 738         { "service", 1, NULL, 's' },
 739 #endif
 740         { "statedir", 1, NULL, 't' },
 741         { NULL, 0, NULL, 0 }
 742     };
 743     int opt_ind = 0, ch, daemonize = 0, i, j, len;
 744     GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
 745     GList *blacklist = NULL;
 746     GAState *s;
 747
 748     module_call_init(MODULE_INIT_QAPI);
 749
 750     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 751         switch (ch) {
 752         case 'm':
 753             method = optarg;
 754             break;
 755         case 'p':
 756             path = optarg;
 757             break;
 758         case 'l':
 759             log_filepath = optarg;
 760             break;
 761         case 'f':
 762             pid_filepath = optarg;
 763             break;
 764 #ifdef CONFIG_FSFREEZE
 765         case 'F':
 766             fsfreeze_hook = optarg ? optarg : QGA_FSFREEZE_HOOK_DEFAULT;
 767             break;
 768 #endif
 769         case 't':
 770              state_dir = optarg;
 771              break;
 772         case 'v':
 773             /* enable all log levels */
 774             log_level = G_LOG_LEVEL_MASK;
 775             break;
 776         case 'V':
 777             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
 778             return 0;
 779         case 'd':
 780             daemonize = 1;
 781             break;
 782         case 'b': {
 783             char **list_head, **list;
 784             if (is_help_option(optarg)) {
 785                 list_head = list = qmp_get_command_list();
 786                 while (*list != NULL) {
 787                     printf("%s\n", *list);
 788                     g_free(*list);
 789                     list++;
 790                 }
 791                 g_free(list_head);
 792                 return 0;
 793             }
 794             for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
 795                 if (optarg[i] == ',') {
 796                     optarg[i] = 0;
 797                     blacklist = g_list_append(blacklist, &optarg[j]);
 798                     j = i + 1;
 799                 }
 800             }
 801             if (j < i) {
 802                 blacklist = g_list_append(blacklist, &optarg[j]);
 803             }
 804             break;
 805         }
 806 #ifdef _WIN32
 807         case 's':
 808             service = optarg;
 809             if (strcmp(service, "install") == 0) {
 810                 return ga_install_service(path, log_filepath);
 811             } else if (strcmp(service, "uninstall") == 0) {
 812                 return ga_uninstall_service();
 813             } else {
 814                 printf("Unknown service command.\n");
 815                 return EXIT_FAILURE;
 816             }
 817             break;
 818 #endif
 819         case 'h':
 820             usage(argv[0]);
 821             return 0;
 822         case '?':
 823             g_print("Unknown option, try '%s --help' for more information.\n",
 824                     argv[0]);
 825             return EXIT_FAILURE;
 826         }
 827     }
 828
 829     s = g_malloc0(sizeof(GAState));
 830     s->log_level = log_level;
 831     s->log_file = stderr;
 832 #ifdef CONFIG_FSFREEZE
 833     s->fsfreeze_hook = fsfreeze_hook;
 834 #endif
 835     g_log_set_default_handler(ga_log, s);
 836     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
 837     ga_enable_logging(s);
 838     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
 839                                                  state_dir);
 840     s->frozen = false;
 841 #ifndef _WIN32
 842     /* check if a previous instance of qemu-ga exited with filesystems' state
 843      * marked as frozen. this could be a stale value (a non-qemu-ga process
 844      * or reboot may have since unfrozen them), but better to require an
 845      * uneeded unfreeze than to risk hanging on start-up
 846      */
 847     struct stat st;
 848     if (stat(s->state_filepath_isfrozen, &st) == -1) {
 849         /* it's okay if the file doesn't exist, but if we can't access for
 850          * some other reason, such as permissions, there's a configuration
 851          * that needs to be addressed. so just bail now before we get into
 852          * more trouble later
 853          */
 854         if (errno != ENOENT) {
 855             g_critical("unable to access state file at path %s: %s",
 856                        s->state_filepath_isfrozen, strerror(errno));
 857             return EXIT_FAILURE;
 858         }
 859     } else {
 860         g_warning("previous instance appears to have exited with frozen"
 861                   " filesystems. deferring logging/pidfile creation and"
 862                   " disabling non-fsfreeze-safe commands until"
 863                   " guest-fsfreeze-thaw is issued, or filesystems are"
 864                   " manually unfrozen and the file %s is removed",
 865                   s->state_filepath_isfrozen);
 866         s->frozen = true;
 867     }
 868 #endif
 869
 870     if (ga_is_frozen(s)) {
 871         if (daemonize) {
 872             /* delay opening/locking of pidfile till filesystem are unfrozen */
 873             s->deferred_options.pid_filepath = pid_filepath;
 874             become_daemon(NULL);
 875         }
 876         if (log_filepath) {
 877             /* delay opening the log file till filesystems are unfrozen */
 878             s->deferred_options.log_filepath = log_filepath;
 879         }
 880         ga_disable_logging(s);
 881         ga_disable_non_whitelisted();
 882     } else {
 883         if (daemonize) {
 884             become_daemon(pid_filepath);
 885         }
 886         if (log_filepath) {
 887             FILE *log_file = fopen(log_filepath, "a");
 888             if (!log_file) {
 889                 g_critical("unable to open specified log file: %s",
 890                            strerror(errno));
 891                 goto out_bad;
 892             }
 893             s->log_file = log_file;
 894         }
 895     }
 896
 897     if (blacklist) {
 898         s->blacklist = blacklist;
 899         do {
 900             g_debug("disabling command: %s", (char *)blacklist->data);
 901             qmp_disable_command(blacklist->data);
 902             blacklist = g_list_next(blacklist);
 903         } while (blacklist);
 904     }
 905     s->command_state = ga_command_state_new();
 906     ga_command_state_init(s, s->command_state);
 907     ga_command_state_init_all(s->command_state);
 908     json_message_parser_init(&s->parser, process_event);
 909     ga_state = s;
 910 #ifndef _WIN32
 911     if (!register_signal_handlers()) {
 912         g_critical("failed to register signal handlers");
 913         goto out_bad;
 914     }
 915 #endif
 916
 917     s->main_loop = g_main_loop_new(NULL, false);
 918     if (!channel_init(ga_state, method, path)) {
 919         g_critical("failed to initialize guest agent channel");
 920         goto out_bad;
 921     }
 922 #ifndef _WIN32
 923     g_main_loop_run(ga_state->main_loop);
 924 #else
 925     if (daemonize) {
 926         SERVICE_TABLE_ENTRY service_table[] = {
 927             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
 928         StartServiceCtrlDispatcher(service_table);
 929     } else {
 930         g_main_loop_run(ga_state->main_loop);
 931     }
 932 #endif
 933
 934     ga_command_state_cleanup_all(ga_state->command_state);
 935     ga_channel_free(ga_state->channel);
 936
 937     if (daemonize) {
 938         unlink(pid_filepath);
 939     }
 940     return 0;
 941
 942 out_bad:
 943     if (daemonize) {
 944         unlink(pid_filepath);
 945     }
 946     return EXIT_FAILURE;
 947 }