qemu-ga.c

   1 /*
   2  * QEMU Guest Agent
   3  *
   4  * Copyright IBM Corp. 2011
   5  *
   6  * Authors:
   7  *  Adam Litke        <aglitke@linux.vnet.ibm.com>
   8  *  Michael Roth      <mdroth@linux.vnet.ibm.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  11  * See the COPYING file in the top-level directory.
  12  */
  13 #include <stdlib.h>
  14 #include <stdio.h>
  15 #include <stdbool.h>
  16 #include <glib.h>
  17 #include <getopt.h>
  18 #ifndef _WIN32
  19 #include <syslog.h>
  20 #include <sys/wait.h>
  21 #include <sys/stat.h>
  22 #endif
  23 #include "json-streamer.h"
  24 #include "json-parser.h"
  25 #include "qint.h"
  26 #include "qjson.h"
  27 #include "qga/guest-agent-core.h"
  28 #include "module.h"
  29 #include "signal.h"
  30 #include "qerror.h"
  31 #include "qapi/qmp-core.h"
  32 #include "qga/channel.h"
  33 #ifdef _WIN32
  34 #include "qga/service-win32.h"
  35 #include <windows.h>
  36 #endif
  37
  38 #ifndef _WIN32
  39 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
  40 #else
  41 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
  42 #endif
  43 #define QGA_PIDFILE_DEFAULT "/var/run/qemu-ga.pid"
  44 #define QGA_STATEDIR_DEFAULT "/tmp"
  45 #define QGA_SENTINEL_BYTE 0xFF
  46
  47 struct GAState {
  48     JSONMessageParser parser;
  49     GMainLoop *main_loop;
  50     GAChannel *channel;
  51     bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
  52     GACommandState *command_state;
  53     GLogLevelFlags log_level;
  54     FILE *log_file;
  55     bool logging_enabled;
  56 #ifdef _WIN32
  57     GAService service;
  58 #endif
  59     bool delimit_response;
  60     bool frozen;
  61     GList *blacklist;
  62     const char *state_filepath_isfrozen;
  63     struct {
  64         const char *log_filepath;
  65         const char *pid_filepath;
  66     } deferred_options;
  67 };
  68
  69 struct GAState *ga_state;
  70
  71 /* commands that are safe to issue while filesystems are frozen */
  72 static const char *ga_freeze_whitelist[] = {
  73     "guest-ping",
  74     "guest-info",
  75     "guest-sync",
  76     "guest-fsfreeze-status",
  77     "guest-fsfreeze-thaw",
  78     NULL
  79 };
  80
  81 #ifdef _WIN32
  82 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
  83                                   LPVOID ctx);
  84 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
  85 #endif
  86
  87 static void quit_handler(int sig)
  88 {
  89     /* if we're frozen, don't exit unless we're absolutely forced to,
  90      * because it's basically impossible for graceful exit to complete
  91      * unless all log/pid files are on unfreezable filesystems. there's
  92      * also a very likely chance killing the agent before unfreezing
  93      * the filesystems is a mistake (or will be viewed as one later).
  94      */
  95     if (ga_is_frozen(ga_state)) {
  96         return;
  97     }
  98     g_debug("received signal num %d, quitting", sig);
  99
 100     if (g_main_loop_is_running(ga_state->main_loop)) {
 101         g_main_loop_quit(ga_state->main_loop);
 102     }
 103 }
 104
 105 #ifndef _WIN32
 106 static gboolean register_signal_handlers(void)
 107 {
 108     struct sigaction sigact;
 109     int ret;
 110
 111     memset(&sigact, 0, sizeof(struct sigaction));
 112     sigact.sa_handler = quit_handler;
 113
 114     ret = sigaction(SIGINT, &sigact, NULL);
 115     if (ret == -1) {
 116         g_error("error configuring signal handler: %s", strerror(errno));
 117         return false;
 118     }
 119     ret = sigaction(SIGTERM, &sigact, NULL);
 120     if (ret == -1) {
 121         g_error("error configuring signal handler: %s", strerror(errno));
 122         return false;
 123     }
 124
 125     return true;
 126 }
 127
 128 /* TODO: use this in place of all post-fork() fclose(std*) callers */
 129 void reopen_fd_to_null(int fd)
 130 {
 131     int nullfd;
 132
 133     nullfd = open("/dev/null", O_RDWR);
 134     if (nullfd < 0) {
 135         return;
 136     }
 137
 138     dup2(nullfd, fd);
 139
 140     if (nullfd != fd) {
 141         close(nullfd);
 142     }
 143 }
 144 #endif
 145
 146 static void usage(const char *cmd)
 147 {
 148     printf(
 149 "Usage: %s [-m <method> -p <path>] [<options>]\n"
 150 "QEMU Guest Agent %s\n"
 151 "\n"
 152 "  -m, --method      transport method: one of unix-listen, virtio-serial, or\n"
 153 "                    isa-serial (virtio-serial is the default)\n"
 154 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
 155 "                    %s)\n"
 156 "  -l, --logfile     set logfile path, logs to stderr by default\n"
 157 "  -f, --pidfile     specify pidfile (default is %s)\n"
 158 "  -t, --statedir    specify dir to store state information (absolute paths\n"
 159 "                    only, default is %s)\n"
 160 "  -v, --verbose     log extra debugging information\n"
 161 "  -V, --version     print version information and exit\n"
 162 "  -d, --daemonize   become a daemon\n"
 163 #ifdef _WIN32
 164 "  -s, --service     service commands: install, uninstall\n"
 165 #endif
 166 "  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\"\n"
 167 "                    to list available RPCs)\n"
 168 "  -h, --help        display this help and exit\n"
 169 "\n"
 170 "Report bugs to <mdroth@linux.vnet.ibm.com>\n"
 171     , cmd, QEMU_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT,
 172     QGA_STATEDIR_DEFAULT);
 173 }
 174
 175 static const char *ga_log_level_str(GLogLevelFlags level)
 176 {
 177     switch (level & G_LOG_LEVEL_MASK) {
 178         case G_LOG_LEVEL_ERROR:
 179             return "error";
 180         case G_LOG_LEVEL_CRITICAL:
 181             return "critical";
 182         case G_LOG_LEVEL_WARNING:
 183             return "warning";
 184         case G_LOG_LEVEL_MESSAGE:
 185             return "message";
 186         case G_LOG_LEVEL_INFO:
 187             return "info";
 188         case G_LOG_LEVEL_DEBUG:
 189             return "debug";
 190         default:
 191             return "user";
 192     }
 193 }
 194
 195 bool ga_logging_enabled(GAState *s)
 196 {
 197     return s->logging_enabled;
 198 }
 199
 200 void ga_disable_logging(GAState *s)
 201 {
 202     s->logging_enabled = false;
 203 }
 204
 205 void ga_enable_logging(GAState *s)
 206 {
 207     s->logging_enabled = true;
 208 }
 209
 210 static void ga_log(const gchar *domain, GLogLevelFlags level,
 211                    const gchar *msg, gpointer opaque)
 212 {
 213     GAState *s = opaque;
 214     GTimeVal time;
 215     const char *level_str = ga_log_level_str(level);
 216
 217     if (!ga_logging_enabled(s)) {
 218         return;
 219     }
 220
 221     level &= G_LOG_LEVEL_MASK;
 222 #ifndef _WIN32
 223     if (domain && strcmp(domain, "syslog") == 0) {
 224         syslog(LOG_INFO, "%s: %s", level_str, msg);
 225     } else if (level & s->log_level) {
 226 #else
 227     if (level & s->log_level) {
 228 #endif
 229         g_get_current_time(&time);
 230         fprintf(s->log_file,
 231                 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
 232         fflush(s->log_file);
 233     }
 234 }
 235
 236 void ga_set_response_delimited(GAState *s)
 237 {
 238     s->delimit_response = true;
 239 }
 240
 241 #ifndef _WIN32
 242 static bool ga_open_pidfile(const char *pidfile)
 243 {
 244     int pidfd;
 245     char pidstr[32];
 246
 247     pidfd = open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
 248     if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) {
 249         g_critical("Cannot lock pid file, %s", strerror(errno));
 250         if (pidfd != -1) {
 251             close(pidfd);
 252         }
 253         return false;
 254     }
 255
 256     if (ftruncate(pidfd, 0) || lseek(pidfd, 0, SEEK_SET)) {
 257         g_critical("Failed to truncate pid file");
 258         goto fail;
 259     }
 260     sprintf(pidstr, "%d", getpid());
 261     if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
 262         g_critical("Failed to write pid file");
 263         goto fail;
 264     }
 265
 266     return true;
 267
 268 fail:
 269     unlink(pidfile);
 270     return false;
 271 }
 272 #else /* _WIN32 */
 273 static bool ga_open_pidfile(const char *pidfile)
 274 {
 275     return true;
 276 }
 277 #endif
 278
 279 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
 280 {
 281     return strcmp(str1, str2);
 282 }
 283
 284 /* disable commands that aren't safe for fsfreeze */
 285 static void ga_disable_non_whitelisted(void)
 286 {
 287     char **list_head, **list;
 288     bool whitelisted;
 289     int i;
 290
 291     list_head = list = qmp_get_command_list();
 292     while (*list != NULL) {
 293         whitelisted = false;
 294         i = 0;
 295         while (ga_freeze_whitelist[i] != NULL) {
 296             if (strcmp(*list, ga_freeze_whitelist[i]) == 0) {
 297                 whitelisted = true;
 298             }
 299             i++;
 300         }
 301         if (!whitelisted) {
 302             g_debug("disabling command: %s", *list);
 303             qmp_disable_command(*list);
 304         }
 305         g_free(*list);
 306         list++;
 307     }
 308     g_free(list_head);
 309 }
 310
 311 /* [re-]enable all commands, except those explicitly blacklisted by user */
 312 static void ga_enable_non_blacklisted(GList *blacklist)
 313 {
 314     char **list_head, **list;
 315
 316     list_head = list = qmp_get_command_list();
 317     while (*list != NULL) {
 318         if (g_list_find_custom(blacklist, *list, ga_strcmp) == NULL &&
 319             !qmp_command_is_enabled(*list)) {
 320             g_debug("enabling command: %s", *list);
 321             qmp_enable_command(*list);
 322         }
 323         g_free(*list);
 324         list++;
 325     }
 326     g_free(list_head);
 327 }
 328
 329 static bool ga_create_file(const char *path)
 330 {
 331     int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
 332     if (fd == -1) {
 333         g_warning("unable to open/create file %s: %s", path, strerror(errno));
 334         return false;
 335     }
 336     close(fd);
 337     return true;
 338 }
 339
 340 static bool ga_delete_file(const char *path)
 341 {
 342     int ret = unlink(path);
 343     if (ret == -1) {
 344         g_warning("unable to delete file: %s: %s", path, strerror(errno));
 345         return false;
 346     }
 347
 348     return true;
 349 }
 350
 351 bool ga_is_frozen(GAState *s)
 352 {
 353     return s->frozen;
 354 }
 355
 356 void ga_set_frozen(GAState *s)
 357 {
 358     if (ga_is_frozen(s)) {
 359         return;
 360     }
 361     /* disable all non-whitelisted (for frozen state) commands */
 362     ga_disable_non_whitelisted();
 363     g_warning("disabling logging due to filesystem freeze");
 364     ga_disable_logging(s);
 365     s->frozen = true;
 366     if (!ga_create_file(s->state_filepath_isfrozen)) {
 367         g_warning("unable to create %s, fsfreeze may not function properly",
 368                   s->state_filepath_isfrozen);
 369     }
 370 }
 371
 372 void ga_unset_frozen(GAState *s)
 373 {
 374     if (!ga_is_frozen(s)) {
 375         return;
 376     }
 377
 378     /* if we delayed creation/opening of pid/log files due to being
 379      * in a frozen state at start up, do it now
 380      */
 381     if (s->deferred_options.log_filepath) {
 382         s->log_file = fopen(s->deferred_options.log_filepath, "a");
 383         if (!s->log_file) {
 384             s->log_file = stderr;
 385         }
 386         s->deferred_options.log_filepath = NULL;
 387     }
 388     ga_enable_logging(s);
 389     g_warning("logging re-enabled due to filesystem unfreeze");
 390     if (s->deferred_options.pid_filepath) {
 391         if (!ga_open_pidfile(s->deferred_options.pid_filepath)) {
 392             g_warning("failed to create/open pid file");
 393         }
 394         s->deferred_options.pid_filepath = NULL;
 395     }
 396
 397     /* enable all disabled, non-blacklisted commands */
 398     ga_enable_non_blacklisted(s->blacklist);
 399     s->frozen = false;
 400     if (!ga_delete_file(s->state_filepath_isfrozen)) {
 401         g_warning("unable to delete %s, fsfreeze may not function properly",
 402                   s->state_filepath_isfrozen);
 403     }
 404 }
 405
 406 static void become_daemon(const char *pidfile)
 407 {
 408 #ifndef _WIN32
 409     pid_t pid, sid;
 410
 411     pid = fork();
 412     if (pid < 0) {
 413         exit(EXIT_FAILURE);
 414     }
 415     if (pid > 0) {
 416         exit(EXIT_SUCCESS);
 417     }
 418
 419     if (pidfile) {
 420         if (!ga_open_pidfile(pidfile)) {
 421             g_critical("failed to create pidfile");
 422             exit(EXIT_FAILURE);
 423         }
 424     }
 425
 426     umask(0);
 427     sid = setsid();
 428     if (sid < 0) {
 429         goto fail;
 430     }
 431     if ((chdir("/")) < 0) {
 432         goto fail;
 433     }
 434
 435     reopen_fd_to_null(STDIN_FILENO);
 436     reopen_fd_to_null(STDOUT_FILENO);
 437     reopen_fd_to_null(STDERR_FILENO);
 438     return;
 439
 440 fail:
 441     unlink(pidfile);
 442     g_critical("failed to daemonize");
 443     exit(EXIT_FAILURE);
 444 #endif
 445 }
 446
 447 static int send_response(GAState *s, QObject *payload)
 448 {
 449     const char *buf;
 450     QString *payload_qstr, *response_qstr;
 451     GIOStatus status;
 452
 453     g_assert(payload && s->channel);
 454
 455     payload_qstr = qobject_to_json(payload);
 456     if (!payload_qstr) {
 457         return -EINVAL;
 458     }
 459
 460     if (s->delimit_response) {
 461         s->delimit_response = false;
 462         response_qstr = qstring_new();
 463         qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
 464         qstring_append(response_qstr, qstring_get_str(payload_qstr));
 465         QDECREF(payload_qstr);
 466     } else {
 467         response_qstr = payload_qstr;
 468     }
 469
 470     qstring_append_chr(response_qstr, '\n');
 471     buf = qstring_get_str(response_qstr);
 472     status = ga_channel_write_all(s->channel, buf, strlen(buf));
 473     QDECREF(response_qstr);
 474     if (status != G_IO_STATUS_NORMAL) {
 475         return -EIO;
 476     }
 477
 478     return 0;
 479 }
 480
 481 static void process_command(GAState *s, QDict *req)
 482 {
 483     QObject *rsp = NULL;
 484     int ret;
 485
 486     g_assert(req);
 487     g_debug("processing command");
 488     rsp = qmp_dispatch(QOBJECT(req));
 489     if (rsp) {
 490         ret = send_response(s, rsp);
 491         if (ret) {
 492             g_warning("error sending response: %s", strerror(ret));
 493         }
 494         qobject_decref(rsp);
 495     }
 496 }
 497
 498 /* handle requests/control events coming in over the channel */
 499 static void process_event(JSONMessageParser *parser, QList *tokens)
 500 {
 501     GAState *s = container_of(parser, GAState, parser);
 502     QObject *obj;
 503     QDict *qdict;
 504     Error *err = NULL;
 505     int ret;
 506
 507     g_assert(s && parser);
 508
 509     g_debug("process_event: called");
 510     obj = json_parser_parse_err(tokens, NULL, &err);
 511     if (err || !obj || qobject_type(obj) != QTYPE_QDICT) {
 512         qobject_decref(obj);
 513         qdict = qdict_new();
 514         if (!err) {
 515             g_warning("failed to parse event: unknown error");
 516             error_set(&err, QERR_JSON_PARSING);
 517         } else {
 518             g_warning("failed to parse event: %s", error_get_pretty(err));
 519         }
 520         qdict_put_obj(qdict, "error", qmp_build_error_object(err));
 521         error_free(err);
 522     } else {
 523         qdict = qobject_to_qdict(obj);
 524     }
 525
 526     g_assert(qdict);
 527
 528     /* handle host->guest commands */
 529     if (qdict_haskey(qdict, "execute")) {
 530         process_command(s, qdict);
 531     } else {
 532         if (!qdict_haskey(qdict, "error")) {
 533             QDECREF(qdict);
 534             qdict = qdict_new();
 535             g_warning("unrecognized payload format");
 536             error_set(&err, QERR_UNSUPPORTED);
 537             qdict_put_obj(qdict, "error", qmp_build_error_object(err));
 538             error_free(err);
 539         }
 540         ret = send_response(s, QOBJECT(qdict));
 541         if (ret) {
 542             g_warning("error sending error response: %s", strerror(ret));
 543         }
 544     }
 545
 546     QDECREF(qdict);
 547 }
 548
 549 /* false return signals GAChannel to close the current client connection */
 550 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 551 {
 552     GAState *s = data;
 553     gchar buf[QGA_READ_COUNT_DEFAULT+1];
 554     gsize count;
 555     GError *err = NULL;
 556     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 557     if (err != NULL) {
 558         g_warning("error reading channel: %s", err->message);
 559         g_error_free(err);
 560         return false;
 561     }
 562     switch (status) {
 563     case G_IO_STATUS_ERROR:
 564         g_warning("error reading channel");
 565         return false;
 566     case G_IO_STATUS_NORMAL:
 567         buf[count] = 0;
 568         g_debug("read data, count: %d, data: %s", (int)count, buf);
 569         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 570         break;
 571     case G_IO_STATUS_EOF:
 572         g_debug("received EOF");
 573         if (!s->virtio) {
 574             return false;
 575         }
 576     case G_IO_STATUS_AGAIN:
 577         /* virtio causes us to spin here when no process is attached to
 578          * host-side chardev. sleep a bit to mitigate this
 579          */
 580         if (s->virtio) {
 581             usleep(100*1000);
 582         }
 583         return true;
 584     default:
 585         g_warning("unknown channel read status, closing");
 586         return false;
 587     }
 588     return true;
 589 }
 590
 591 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
 592 {
 593     GAChannelMethod channel_method;
 594
 595     if (method == NULL) {
 596         method = "virtio-serial";
 597     }
 598
 599     if (path == NULL) {
 600         if (strcmp(method, "virtio-serial") != 0) {
 601             g_critical("must specify a path for this channel");
 602             return false;
 603         }
 604         /* try the default path for the virtio-serial port */
 605         path = QGA_VIRTIO_PATH_DEFAULT;
 606     }
 607
 608     if (strcmp(method, "virtio-serial") == 0) {
 609         s->virtio = true; /* virtio requires special handling in some cases */
 610         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 611     } else if (strcmp(method, "isa-serial") == 0) {
 612         channel_method = GA_CHANNEL_ISA_SERIAL;
 613     } else if (strcmp(method, "unix-listen") == 0) {
 614         channel_method = GA_CHANNEL_UNIX_LISTEN;
 615     } else {
 616         g_critical("unsupported channel method/type: %s", method);
 617         return false;
 618     }
 619
 620     s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
 621     if (!s->channel) {
 622         g_critical("failed to create guest agent channel");
 623         return false;
 624     }
 625
 626     return true;
 627 }
 628
 629 #ifdef _WIN32
 630 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 631                                   LPVOID ctx)
 632 {
 633     DWORD ret = NO_ERROR;
 634     GAService *service = &ga_state->service;
 635
 636     switch (ctrl)
 637     {
 638         case SERVICE_CONTROL_STOP:
 639         case SERVICE_CONTROL_SHUTDOWN:
 640             quit_handler(SIGTERM);
 641             service->status.dwCurrentState = SERVICE_STOP_PENDING;
 642             SetServiceStatus(service->status_handle, &service->status);
 643             break;
 644
 645         default:
 646             ret = ERROR_CALL_NOT_IMPLEMENTED;
 647     }
 648     return ret;
 649 }
 650
 651 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 652 {
 653     GAService *service = &ga_state->service;
 654
 655     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 656         service_ctrl_handler, NULL);
 657
 658     if (service->status_handle == 0) {
 659         g_critical("Failed to register extended requests function!\n");
 660         return;
 661     }
 662
 663     service->status.dwServiceType = SERVICE_WIN32;
 664     service->status.dwCurrentState = SERVICE_RUNNING;
 665     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 666     service->status.dwWin32ExitCode = NO_ERROR;
 667     service->status.dwServiceSpecificExitCode = NO_ERROR;
 668     service->status.dwCheckPoint = 0;
 669     service->status.dwWaitHint = 0;
 670     SetServiceStatus(service->status_handle, &service->status);
 671
 672     g_main_loop_run(ga_state->main_loop);
 673
 674     service->status.dwCurrentState = SERVICE_STOPPED;
 675     SetServiceStatus(service->status_handle, &service->status);
 676 }
 677 #endif
 678
 679 int main(int argc, char **argv)
 680 {
 681     const char *sopt = "hVvdm:p:l:f:b:s:t:";
 682     const char *method = NULL, *path = NULL;
 683     const char *log_filepath = NULL;
 684     const char *pid_filepath = QGA_PIDFILE_DEFAULT;
 685     const char *state_dir = QGA_STATEDIR_DEFAULT;
 686 #ifdef _WIN32
 687     const char *service = NULL;
 688 #endif
 689     const struct option lopt[] = {
 690         { "help", 0, NULL, 'h' },
 691         { "version", 0, NULL, 'V' },
 692         { "logfile", 1, NULL, 'l' },
 693         { "pidfile", 1, NULL, 'f' },
 694         { "verbose", 0, NULL, 'v' },
 695         { "method", 1, NULL, 'm' },
 696         { "path", 1, NULL, 'p' },
 697         { "daemonize", 0, NULL, 'd' },
 698         { "blacklist", 1, NULL, 'b' },
 699 #ifdef _WIN32
 700         { "service", 1, NULL, 's' },
 701 #endif
 702         { "statedir", 1, NULL, 't' },
 703         { NULL, 0, NULL, 0 }
 704     };
 705     int opt_ind = 0, ch, daemonize = 0, i, j, len;
 706     GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
 707     GList *blacklist = NULL;
 708     GAState *s;
 709
 710     module_call_init(MODULE_INIT_QAPI);
 711
 712     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 713         switch (ch) {
 714         case 'm':
 715             method = optarg;
 716             break;
 717         case 'p':
 718             path = optarg;
 719             break;
 720         case 'l':
 721             log_filepath = optarg;
 722             break;
 723         case 'f':
 724             pid_filepath = optarg;
 725             break;
 726         case 't':
 727              state_dir = optarg;
 728              break;
 729         case 'v':
 730             /* enable all log levels */
 731             log_level = G_LOG_LEVEL_MASK;
 732             break;
 733         case 'V':
 734             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
 735             return 0;
 736         case 'd':
 737             daemonize = 1;
 738             break;
 739         case 'b': {
 740             char **list_head, **list;
 741             if (is_help_option(optarg)) {
 742                 list_head = list = qmp_get_command_list();
 743                 while (*list != NULL) {
 744                     printf("%s\n", *list);
 745                     g_free(*list);
 746                     list++;
 747                 }
 748                 g_free(list_head);
 749                 return 0;
 750             }
 751             for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
 752                 if (optarg[i] == ',') {
 753                     optarg[i] = 0;
 754                     blacklist = g_list_append(blacklist, &optarg[j]);
 755                     j = i + 1;
 756                 }
 757             }
 758             if (j < i) {
 759                 blacklist = g_list_append(blacklist, &optarg[j]);
 760             }
 761             break;
 762         }
 763 #ifdef _WIN32
 764         case 's':
 765             service = optarg;
 766             if (strcmp(service, "install") == 0) {
 767                 return ga_install_service(path, log_filepath);
 768             } else if (strcmp(service, "uninstall") == 0) {
 769                 return ga_uninstall_service();
 770             } else {
 771                 printf("Unknown service command.\n");
 772                 return EXIT_FAILURE;
 773             }
 774             break;
 775 #endif
 776         case 'h':
 777             usage(argv[0]);
 778             return 0;
 779         case '?':
 780             g_print("Unknown option, try '%s --help' for more information.\n",
 781                     argv[0]);
 782             return EXIT_FAILURE;
 783         }
 784     }
 785
 786     s = g_malloc0(sizeof(GAState));
 787     s->log_level = log_level;
 788     s->log_file = stderr;
 789     g_log_set_default_handler(ga_log, s);
 790     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
 791     ga_enable_logging(s);
 792     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
 793                                                  state_dir);
 794     s->frozen = false;
 795 #ifndef _WIN32
 796     /* check if a previous instance of qemu-ga exited with filesystems' state
 797      * marked as frozen. this could be a stale value (a non-qemu-ga process
 798      * or reboot may have since unfrozen them), but better to require an
 799      * uneeded unfreeze than to risk hanging on start-up
 800      */
 801     struct stat st;
 802     if (stat(s->state_filepath_isfrozen, &st) == -1) {
 803         /* it's okay if the file doesn't exist, but if we can't access for
 804          * some other reason, such as permissions, there's a configuration
 805          * that needs to be addressed. so just bail now before we get into
 806          * more trouble later
 807          */
 808         if (errno != ENOENT) {
 809             g_critical("unable to access state file at path %s: %s",
 810                        s->state_filepath_isfrozen, strerror(errno));
 811             return EXIT_FAILURE;
 812         }
 813     } else {
 814         g_warning("previous instance appears to have exited with frozen"
 815                   " filesystems. deferring logging/pidfile creation and"
 816                   " disabling non-fsfreeze-safe commands until"
 817                   " guest-fsfreeze-thaw is issued, or filesystems are"
 818                   " manually unfrozen and the file %s is removed",
 819                   s->state_filepath_isfrozen);
 820         s->frozen = true;
 821     }
 822 #endif
 823
 824     if (ga_is_frozen(s)) {
 825         if (daemonize) {
 826             /* delay opening/locking of pidfile till filesystem are unfrozen */
 827             s->deferred_options.pid_filepath = pid_filepath;
 828             become_daemon(NULL);
 829         }
 830         if (log_filepath) {
 831             /* delay opening the log file till filesystems are unfrozen */
 832             s->deferred_options.log_filepath = log_filepath;
 833         }
 834         ga_disable_logging(s);
 835         ga_disable_non_whitelisted();
 836     } else {
 837         if (daemonize) {
 838             become_daemon(pid_filepath);
 839         }
 840         if (log_filepath) {
 841             FILE *log_file = fopen(log_filepath, "a");
 842             if (!log_file) {
 843                 g_critical("unable to open specified log file: %s",
 844                            strerror(errno));
 845                 goto out_bad;
 846             }
 847             s->log_file = log_file;
 848         }
 849     }
 850
 851     if (blacklist) {
 852         s->blacklist = blacklist;
 853         do {
 854             g_debug("disabling command: %s", (char *)blacklist->data);
 855             qmp_disable_command(blacklist->data);
 856             blacklist = g_list_next(blacklist);
 857         } while (blacklist);
 858     }
 859     s->command_state = ga_command_state_new();
 860     ga_command_state_init(s, s->command_state);
 861     ga_command_state_init_all(s->command_state);
 862     json_message_parser_init(&s->parser, process_event);
 863     ga_state = s;
 864 #ifndef _WIN32
 865     if (!register_signal_handlers()) {
 866         g_critical("failed to register signal handlers");
 867         goto out_bad;
 868     }
 869 #endif
 870
 871     s->main_loop = g_main_loop_new(NULL, false);
 872     if (!channel_init(ga_state, method, path)) {
 873         g_critical("failed to initialize guest agent channel");
 874         goto out_bad;
 875     }
 876 #ifndef _WIN32
 877     g_main_loop_run(ga_state->main_loop);
 878 #else
 879     if (daemonize) {
 880         SERVICE_TABLE_ENTRY service_table[] = {
 881             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
 882         StartServiceCtrlDispatcher(service_table);
 883     } else {
 884         g_main_loop_run(ga_state->main_loop);
 885     }
 886 #endif
 887
 888     ga_command_state_cleanup_all(ga_state->command_state);
 889     ga_channel_free(ga_state->channel);
 890
 891     if (daemonize) {
 892         unlink(pid_filepath);
 893     }
 894     return 0;
 895
 896 out_bad:
 897     if (daemonize) {
 898         unlink(pid_filepath);
 899     }
 900     return EXIT_FAILURE;
 901 }