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         return false;
 251     }
 252
 253     if (ftruncate(pidfd, 0) || lseek(pidfd, 0, SEEK_SET)) {
 254         g_critical("Failed to truncate pid file");
 255         goto fail;
 256     }
 257     sprintf(pidstr, "%d", getpid());
 258     if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
 259         g_critical("Failed to write pid file");
 260         goto fail;
 261     }
 262
 263     return true;
 264
 265 fail:
 266     unlink(pidfile);
 267     return false;
 268 }
 269 #else /* _WIN32 */
 270 static bool ga_open_pidfile(const char *pidfile)
 271 {
 272     return true;
 273 }
 274 #endif
 275
 276 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
 277 {
 278     return strcmp(str1, str2);
 279 }
 280
 281 /* disable commands that aren't safe for fsfreeze */
 282 static void ga_disable_non_whitelisted(void)
 283 {
 284     char **list_head, **list;
 285     bool whitelisted;
 286     int i;
 287
 288     list_head = list = qmp_get_command_list();
 289     while (*list != NULL) {
 290         whitelisted = false;
 291         i = 0;
 292         while (ga_freeze_whitelist[i] != NULL) {
 293             if (strcmp(*list, ga_freeze_whitelist[i]) == 0) {
 294                 whitelisted = true;
 295             }
 296             i++;
 297         }
 298         if (!whitelisted) {
 299             g_debug("disabling command: %s", *list);
 300             qmp_disable_command(*list);
 301         }
 302         g_free(*list);
 303         list++;
 304     }
 305     g_free(list_head);
 306 }
 307
 308 /* [re-]enable all commands, except those explicitly blacklisted by user */
 309 static void ga_enable_non_blacklisted(GList *blacklist)
 310 {
 311     char **list_head, **list;
 312
 313     list_head = list = qmp_get_command_list();
 314     while (*list != NULL) {
 315         if (g_list_find_custom(blacklist, *list, ga_strcmp) == NULL &&
 316             !qmp_command_is_enabled(*list)) {
 317             g_debug("enabling command: %s", *list);
 318             qmp_enable_command(*list);
 319         }
 320         g_free(*list);
 321         list++;
 322     }
 323     g_free(list_head);
 324 }
 325
 326 static bool ga_create_file(const char *path)
 327 {
 328     int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
 329     if (fd == -1) {
 330         g_warning("unable to open/create file %s: %s", path, strerror(errno));
 331         return false;
 332     }
 333     close(fd);
 334     return true;
 335 }
 336
 337 static bool ga_delete_file(const char *path)
 338 {
 339     int ret = unlink(path);
 340     if (ret == -1) {
 341         g_warning("unable to delete file: %s: %s", path, strerror(errno));
 342         return false;
 343     }
 344
 345     return true;
 346 }
 347
 348 bool ga_is_frozen(GAState *s)
 349 {
 350     return s->frozen;
 351 }
 352
 353 void ga_set_frozen(GAState *s)
 354 {
 355     if (ga_is_frozen(s)) {
 356         return;
 357     }
 358     /* disable all non-whitelisted (for frozen state) commands */
 359     ga_disable_non_whitelisted();
 360     g_warning("disabling logging due to filesystem freeze");
 361     ga_disable_logging(s);
 362     s->frozen = true;
 363     if (!ga_create_file(s->state_filepath_isfrozen)) {
 364         g_warning("unable to create %s, fsfreeze may not function properly",
 365                   s->state_filepath_isfrozen);
 366     }
 367 }
 368
 369 void ga_unset_frozen(GAState *s)
 370 {
 371     if (!ga_is_frozen(s)) {
 372         return;
 373     }
 374
 375     /* if we delayed creation/opening of pid/log files due to being
 376      * in a frozen state at start up, do it now
 377      */
 378     if (s->deferred_options.log_filepath) {
 379         s->log_file = fopen(s->deferred_options.log_filepath, "a");
 380         if (!s->log_file) {
 381             s->log_file = stderr;
 382         }
 383         s->deferred_options.log_filepath = NULL;
 384     }
 385     ga_enable_logging(s);
 386     g_warning("logging re-enabled due to filesystem unfreeze");
 387     if (s->deferred_options.pid_filepath) {
 388         if (!ga_open_pidfile(s->deferred_options.pid_filepath)) {
 389             g_warning("failed to create/open pid file");
 390         }
 391         s->deferred_options.pid_filepath = NULL;
 392     }
 393
 394     /* enable all disabled, non-blacklisted commands */
 395     ga_enable_non_blacklisted(s->blacklist);
 396     s->frozen = false;
 397     if (!ga_delete_file(s->state_filepath_isfrozen)) {
 398         g_warning("unable to delete %s, fsfreeze may not function properly",
 399                   s->state_filepath_isfrozen);
 400     }
 401 }
 402
 403 static void become_daemon(const char *pidfile)
 404 {
 405 #ifndef _WIN32
 406     pid_t pid, sid;
 407
 408     pid = fork();
 409     if (pid < 0) {
 410         exit(EXIT_FAILURE);
 411     }
 412     if (pid > 0) {
 413         exit(EXIT_SUCCESS);
 414     }
 415
 416     if (pidfile) {
 417         if (!ga_open_pidfile(pidfile)) {
 418             g_critical("failed to create pidfile");
 419             exit(EXIT_FAILURE);
 420         }
 421     }
 422
 423     umask(0);
 424     sid = setsid();
 425     if (sid < 0) {
 426         goto fail;
 427     }
 428     if ((chdir("/")) < 0) {
 429         goto fail;
 430     }
 431
 432     reopen_fd_to_null(STDIN_FILENO);
 433     reopen_fd_to_null(STDOUT_FILENO);
 434     reopen_fd_to_null(STDERR_FILENO);
 435     return;
 436
 437 fail:
 438     unlink(pidfile);
 439     g_critical("failed to daemonize");
 440     exit(EXIT_FAILURE);
 441 #endif
 442 }
 443
 444 static int send_response(GAState *s, QObject *payload)
 445 {
 446     const char *buf;
 447     QString *payload_qstr, *response_qstr;
 448     GIOStatus status;
 449
 450     g_assert(payload && s->channel);
 451
 452     payload_qstr = qobject_to_json(payload);
 453     if (!payload_qstr) {
 454         return -EINVAL;
 455     }
 456
 457     if (s->delimit_response) {
 458         s->delimit_response = false;
 459         response_qstr = qstring_new();
 460         qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
 461         qstring_append(response_qstr, qstring_get_str(payload_qstr));
 462         QDECREF(payload_qstr);
 463     } else {
 464         response_qstr = payload_qstr;
 465     }
 466
 467     qstring_append_chr(response_qstr, '\n');
 468     buf = qstring_get_str(response_qstr);
 469     status = ga_channel_write_all(s->channel, buf, strlen(buf));
 470     QDECREF(response_qstr);
 471     if (status != G_IO_STATUS_NORMAL) {
 472         return -EIO;
 473     }
 474
 475     return 0;
 476 }
 477
 478 static void process_command(GAState *s, QDict *req)
 479 {
 480     QObject *rsp = NULL;
 481     int ret;
 482
 483     g_assert(req);
 484     g_debug("processing command");
 485     rsp = qmp_dispatch(QOBJECT(req));
 486     if (rsp) {
 487         ret = send_response(s, rsp);
 488         if (ret) {
 489             g_warning("error sending response: %s", strerror(ret));
 490         }
 491         qobject_decref(rsp);
 492     }
 493 }
 494
 495 /* handle requests/control events coming in over the channel */
 496 static void process_event(JSONMessageParser *parser, QList *tokens)
 497 {
 498     GAState *s = container_of(parser, GAState, parser);
 499     QObject *obj;
 500     QDict *qdict;
 501     Error *err = NULL;
 502     int ret;
 503
 504     g_assert(s && parser);
 505
 506     g_debug("process_event: called");
 507     obj = json_parser_parse_err(tokens, NULL, &err);
 508     if (err || !obj || qobject_type(obj) != QTYPE_QDICT) {
 509         qobject_decref(obj);
 510         qdict = qdict_new();
 511         if (!err) {
 512             g_warning("failed to parse event: unknown error");
 513             error_set(&err, QERR_JSON_PARSING);
 514         } else {
 515             g_warning("failed to parse event: %s", error_get_pretty(err));
 516         }
 517         qdict_put_obj(qdict, "error", qmp_build_error_object(err));
 518         error_free(err);
 519     } else {
 520         qdict = qobject_to_qdict(obj);
 521     }
 522
 523     g_assert(qdict);
 524
 525     /* handle host->guest commands */
 526     if (qdict_haskey(qdict, "execute")) {
 527         process_command(s, qdict);
 528     } else {
 529         if (!qdict_haskey(qdict, "error")) {
 530             QDECREF(qdict);
 531             qdict = qdict_new();
 532             g_warning("unrecognized payload format");
 533             error_set(&err, QERR_UNSUPPORTED);
 534             qdict_put_obj(qdict, "error", qmp_build_error_object(err));
 535             error_free(err);
 536         }
 537         ret = send_response(s, QOBJECT(qdict));
 538         if (ret) {
 539             g_warning("error sending error response: %s", strerror(ret));
 540         }
 541     }
 542
 543     QDECREF(qdict);
 544 }
 545
 546 /* false return signals GAChannel to close the current client connection */
 547 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 548 {
 549     GAState *s = data;
 550     gchar buf[QGA_READ_COUNT_DEFAULT+1];
 551     gsize count;
 552     GError *err = NULL;
 553     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 554     if (err != NULL) {
 555         g_warning("error reading channel: %s", err->message);
 556         g_error_free(err);
 557         return false;
 558     }
 559     switch (status) {
 560     case G_IO_STATUS_ERROR:
 561         g_warning("error reading channel");
 562         return false;
 563     case G_IO_STATUS_NORMAL:
 564         buf[count] = 0;
 565         g_debug("read data, count: %d, data: %s", (int)count, buf);
 566         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 567         break;
 568     case G_IO_STATUS_EOF:
 569         g_debug("received EOF");
 570         if (!s->virtio) {
 571             return false;
 572         }
 573     case G_IO_STATUS_AGAIN:
 574         /* virtio causes us to spin here when no process is attached to
 575          * host-side chardev. sleep a bit to mitigate this
 576          */
 577         if (s->virtio) {
 578             usleep(100*1000);
 579         }
 580         return true;
 581     default:
 582         g_warning("unknown channel read status, closing");
 583         return false;
 584     }
 585     return true;
 586 }
 587
 588 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
 589 {
 590     GAChannelMethod channel_method;
 591
 592     if (method == NULL) {
 593         method = "virtio-serial";
 594     }
 595
 596     if (path == NULL) {
 597         if (strcmp(method, "virtio-serial") != 0) {
 598             g_critical("must specify a path for this channel");
 599             return false;
 600         }
 601         /* try the default path for the virtio-serial port */
 602         path = QGA_VIRTIO_PATH_DEFAULT;
 603     }
 604
 605     if (strcmp(method, "virtio-serial") == 0) {
 606         s->virtio = true; /* virtio requires special handling in some cases */
 607         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 608     } else if (strcmp(method, "isa-serial") == 0) {
 609         channel_method = GA_CHANNEL_ISA_SERIAL;
 610     } else if (strcmp(method, "unix-listen") == 0) {
 611         channel_method = GA_CHANNEL_UNIX_LISTEN;
 612     } else {
 613         g_critical("unsupported channel method/type: %s", method);
 614         return false;
 615     }
 616
 617     s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
 618     if (!s->channel) {
 619         g_critical("failed to create guest agent channel");
 620         return false;
 621     }
 622
 623     return true;
 624 }
 625
 626 #ifdef _WIN32
 627 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 628                                   LPVOID ctx)
 629 {
 630     DWORD ret = NO_ERROR;
 631     GAService *service = &ga_state->service;
 632
 633     switch (ctrl)
 634     {
 635         case SERVICE_CONTROL_STOP:
 636         case SERVICE_CONTROL_SHUTDOWN:
 637             quit_handler(SIGTERM);
 638             service->status.dwCurrentState = SERVICE_STOP_PENDING;
 639             SetServiceStatus(service->status_handle, &service->status);
 640             break;
 641
 642         default:
 643             ret = ERROR_CALL_NOT_IMPLEMENTED;
 644     }
 645     return ret;
 646 }
 647
 648 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 649 {
 650     GAService *service = &ga_state->service;
 651
 652     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 653         service_ctrl_handler, NULL);
 654
 655     if (service->status_handle == 0) {
 656         g_critical("Failed to register extended requests function!\n");
 657         return;
 658     }
 659
 660     service->status.dwServiceType = SERVICE_WIN32;
 661     service->status.dwCurrentState = SERVICE_RUNNING;
 662     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 663     service->status.dwWin32ExitCode = NO_ERROR;
 664     service->status.dwServiceSpecificExitCode = NO_ERROR;
 665     service->status.dwCheckPoint = 0;
 666     service->status.dwWaitHint = 0;
 667     SetServiceStatus(service->status_handle, &service->status);
 668
 669     g_main_loop_run(ga_state->main_loop);
 670
 671     service->status.dwCurrentState = SERVICE_STOPPED;
 672     SetServiceStatus(service->status_handle, &service->status);
 673 }
 674 #endif
 675
 676 int main(int argc, char **argv)
 677 {
 678     const char *sopt = "hVvdm:p:l:f:b:s:t:";
 679     const char *method = NULL, *path = NULL;
 680     const char *log_filepath = NULL;
 681     const char *pid_filepath = QGA_PIDFILE_DEFAULT;
 682     const char *state_dir = QGA_STATEDIR_DEFAULT;
 683 #ifdef _WIN32
 684     const char *service = NULL;
 685 #endif
 686     const struct option lopt[] = {
 687         { "help", 0, NULL, 'h' },
 688         { "version", 0, NULL, 'V' },
 689         { "logfile", 1, NULL, 'l' },
 690         { "pidfile", 1, NULL, 'f' },
 691         { "verbose", 0, NULL, 'v' },
 692         { "method", 1, NULL, 'm' },
 693         { "path", 1, NULL, 'p' },
 694         { "daemonize", 0, NULL, 'd' },
 695         { "blacklist", 1, NULL, 'b' },
 696 #ifdef _WIN32
 697         { "service", 1, NULL, 's' },
 698 #endif
 699         { "statedir", 1, NULL, 't' },
 700         { NULL, 0, NULL, 0 }
 701     };
 702     int opt_ind = 0, ch, daemonize = 0, i, j, len;
 703     GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
 704     GList *blacklist = NULL;
 705     GAState *s;
 706
 707     module_call_init(MODULE_INIT_QAPI);
 708
 709     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 710         switch (ch) {
 711         case 'm':
 712             method = optarg;
 713             break;
 714         case 'p':
 715             path = optarg;
 716             break;
 717         case 'l':
 718             log_filepath = optarg;
 719             break;
 720         case 'f':
 721             pid_filepath = optarg;
 722             break;
 723         case 't':
 724              state_dir = optarg;
 725              break;
 726         case 'v':
 727             /* enable all log levels */
 728             log_level = G_LOG_LEVEL_MASK;
 729             break;
 730         case 'V':
 731             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
 732             return 0;
 733         case 'd':
 734             daemonize = 1;
 735             break;
 736         case 'b': {
 737             char **list_head, **list;
 738             if (is_help_option(optarg)) {
 739                 list_head = list = qmp_get_command_list();
 740                 while (*list != NULL) {
 741                     printf("%s\n", *list);
 742                     g_free(*list);
 743                     list++;
 744                 }
 745                 g_free(list_head);
 746                 return 0;
 747             }
 748             for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
 749                 if (optarg[i] == ',') {
 750                     optarg[i] = 0;
 751                     blacklist = g_list_append(blacklist, &optarg[j]);
 752                     j = i + 1;
 753                 }
 754             }
 755             if (j < i) {
 756                 blacklist = g_list_append(blacklist, &optarg[j]);
 757             }
 758             break;
 759         }
 760 #ifdef _WIN32
 761         case 's':
 762             service = optarg;
 763             if (strcmp(service, "install") == 0) {
 764                 return ga_install_service(path, log_filepath);
 765             } else if (strcmp(service, "uninstall") == 0) {
 766                 return ga_uninstall_service();
 767             } else {
 768                 printf("Unknown service command.\n");
 769                 return EXIT_FAILURE;
 770             }
 771             break;
 772 #endif
 773         case 'h':
 774             usage(argv[0]);
 775             return 0;
 776         case '?':
 777             g_print("Unknown option, try '%s --help' for more information.\n",
 778                     argv[0]);
 779             return EXIT_FAILURE;
 780         }
 781     }
 782
 783     s = g_malloc0(sizeof(GAState));
 784     s->log_level = log_level;
 785     s->log_file = stderr;
 786     g_log_set_default_handler(ga_log, s);
 787     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
 788     ga_enable_logging(s);
 789     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
 790                                                  state_dir);
 791     s->frozen = false;
 792 #ifndef _WIN32
 793     /* check if a previous instance of qemu-ga exited with filesystems' state
 794      * marked as frozen. this could be a stale value (a non-qemu-ga process
 795      * or reboot may have since unfrozen them), but better to require an
 796      * uneeded unfreeze than to risk hanging on start-up
 797      */
 798     struct stat st;
 799     if (stat(s->state_filepath_isfrozen, &st) == -1) {
 800         /* it's okay if the file doesn't exist, but if we can't access for
 801          * some other reason, such as permissions, there's a configuration
 802          * that needs to be addressed. so just bail now before we get into
 803          * more trouble later
 804          */
 805         if (errno != ENOENT) {
 806             g_critical("unable to access state file at path %s: %s",
 807                        s->state_filepath_isfrozen, strerror(errno));
 808             return EXIT_FAILURE;
 809         }
 810     } else {
 811         g_warning("previous instance appears to have exited with frozen"
 812                   " filesystems. deferring logging/pidfile creation and"
 813                   " disabling non-fsfreeze-safe commands until"
 814                   " guest-fsfreeze-thaw is issued, or filesystems are"
 815                   " manually unfrozen and the file %s is removed",
 816                   s->state_filepath_isfrozen);
 817         s->frozen = true;
 818     }
 819 #endif
 820
 821     if (ga_is_frozen(s)) {
 822         if (daemonize) {
 823             /* delay opening/locking of pidfile till filesystem are unfrozen */
 824             s->deferred_options.pid_filepath = pid_filepath;
 825             become_daemon(NULL);
 826         }
 827         if (log_filepath) {
 828             /* delay opening the log file till filesystems are unfrozen */
 829             s->deferred_options.log_filepath = log_filepath;
 830         }
 831         ga_disable_logging(s);
 832         ga_disable_non_whitelisted();
 833     } else {
 834         if (daemonize) {
 835             become_daemon(pid_filepath);
 836         }
 837         if (log_filepath) {
 838             FILE *log_file = fopen(log_filepath, "a");
 839             if (!log_file) {
 840                 g_critical("unable to open specified log file: %s",
 841                            strerror(errno));
 842                 goto out_bad;
 843             }
 844             s->log_file = log_file;
 845         }
 846     }
 847
 848     if (blacklist) {
 849         s->blacklist = blacklist;
 850         do {
 851             g_debug("disabling command: %s", (char *)blacklist->data);
 852             qmp_disable_command(blacklist->data);
 853             blacklist = g_list_next(blacklist);
 854         } while (blacklist);
 855     }
 856     s->command_state = ga_command_state_new();
 857     ga_command_state_init(s, s->command_state);
 858     ga_command_state_init_all(s->command_state);
 859     json_message_parser_init(&s->parser, process_event);
 860     ga_state = s;
 861 #ifndef _WIN32
 862     if (!register_signal_handlers()) {
 863         g_critical("failed to register signal handlers");
 864         goto out_bad;
 865     }
 866 #endif
 867
 868     s->main_loop = g_main_loop_new(NULL, false);
 869     if (!channel_init(ga_state, method, path)) {
 870         g_critical("failed to initialize guest agent channel");
 871         goto out_bad;
 872     }
 873 #ifndef _WIN32
 874     g_main_loop_run(ga_state->main_loop);
 875 #else
 876     if (daemonize) {
 877         SERVICE_TABLE_ENTRY service_table[] = {
 878             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
 879         StartServiceCtrlDispatcher(service_table);
 880     } else {
 881         g_main_loop_run(ga_state->main_loop);
 882     }
 883 #endif
 884
 885     ga_command_state_cleanup_all(ga_state->command_state);
 886     ga_channel_free(ga_state->channel);
 887
 888     if (daemonize) {
 889         unlink(pid_filepath);
 890     }
 891     return 0;
 892
 893 out_bad:
 894     if (daemonize) {
 895         unlink(pid_filepath);
 896     }
 897     return EXIT_FAILURE;
 898 }