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     if (pidfile) {
 442         unlink(pidfile);
 443     }
 444     g_critical("failed to daemonize");
 445     exit(EXIT_FAILURE);
 446 #endif
 447 }
 448
 449 static int send_response(GAState *s, QObject *payload)
 450 {
 451     const char *buf;
 452     QString *payload_qstr, *response_qstr;
 453     GIOStatus status;
 454
 455     g_assert(payload && s->channel);
 456
 457     payload_qstr = qobject_to_json(payload);
 458     if (!payload_qstr) {
 459         return -EINVAL;
 460     }
 461
 462     if (s->delimit_response) {
 463         s->delimit_response = false;
 464         response_qstr = qstring_new();
 465         qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
 466         qstring_append(response_qstr, qstring_get_str(payload_qstr));
 467         QDECREF(payload_qstr);
 468     } else {
 469         response_qstr = payload_qstr;
 470     }
 471
 472     qstring_append_chr(response_qstr, '\n');
 473     buf = qstring_get_str(response_qstr);
 474     status = ga_channel_write_all(s->channel, buf, strlen(buf));
 475     QDECREF(response_qstr);
 476     if (status != G_IO_STATUS_NORMAL) {
 477         return -EIO;
 478     }
 479
 480     return 0;
 481 }
 482
 483 static void process_command(GAState *s, QDict *req)
 484 {
 485     QObject *rsp = NULL;
 486     int ret;
 487
 488     g_assert(req);
 489     g_debug("processing command");
 490     rsp = qmp_dispatch(QOBJECT(req));
 491     if (rsp) {
 492         ret = send_response(s, rsp);
 493         if (ret) {
 494             g_warning("error sending response: %s", strerror(ret));
 495         }
 496         qobject_decref(rsp);
 497     }
 498 }
 499
 500 /* handle requests/control events coming in over the channel */
 501 static void process_event(JSONMessageParser *parser, QList *tokens)
 502 {
 503     GAState *s = container_of(parser, GAState, parser);
 504     QObject *obj;
 505     QDict *qdict;
 506     Error *err = NULL;
 507     int ret;
 508
 509     g_assert(s && parser);
 510
 511     g_debug("process_event: called");
 512     obj = json_parser_parse_err(tokens, NULL, &err);
 513     if (err || !obj || qobject_type(obj) != QTYPE_QDICT) {
 514         qobject_decref(obj);
 515         qdict = qdict_new();
 516         if (!err) {
 517             g_warning("failed to parse event: unknown error");
 518             error_set(&err, QERR_JSON_PARSING);
 519         } else {
 520             g_warning("failed to parse event: %s", error_get_pretty(err));
 521         }
 522         qdict_put_obj(qdict, "error", qmp_build_error_object(err));
 523         error_free(err);
 524     } else {
 525         qdict = qobject_to_qdict(obj);
 526     }
 527
 528     g_assert(qdict);
 529
 530     /* handle host->guest commands */
 531     if (qdict_haskey(qdict, "execute")) {
 532         process_command(s, qdict);
 533     } else {
 534         if (!qdict_haskey(qdict, "error")) {
 535             QDECREF(qdict);
 536             qdict = qdict_new();
 537             g_warning("unrecognized payload format");
 538             error_set(&err, QERR_UNSUPPORTED);
 539             qdict_put_obj(qdict, "error", qmp_build_error_object(err));
 540             error_free(err);
 541         }
 542         ret = send_response(s, QOBJECT(qdict));
 543         if (ret) {
 544             g_warning("error sending error response: %s", strerror(ret));
 545         }
 546     }
 547
 548     QDECREF(qdict);
 549 }
 550
 551 /* false return signals GAChannel to close the current client connection */
 552 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 553 {
 554     GAState *s = data;
 555     gchar buf[QGA_READ_COUNT_DEFAULT+1];
 556     gsize count;
 557     GError *err = NULL;
 558     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 559     if (err != NULL) {
 560         g_warning("error reading channel: %s", err->message);
 561         g_error_free(err);
 562         return false;
 563     }
 564     switch (status) {
 565     case G_IO_STATUS_ERROR:
 566         g_warning("error reading channel");
 567         return false;
 568     case G_IO_STATUS_NORMAL:
 569         buf[count] = 0;
 570         g_debug("read data, count: %d, data: %s", (int)count, buf);
 571         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 572         break;
 573     case G_IO_STATUS_EOF:
 574         g_debug("received EOF");
 575         if (!s->virtio) {
 576             return false;
 577         }
 578     case G_IO_STATUS_AGAIN:
 579         /* virtio causes us to spin here when no process is attached to
 580          * host-side chardev. sleep a bit to mitigate this
 581          */
 582         if (s->virtio) {
 583             usleep(100*1000);
 584         }
 585         return true;
 586     default:
 587         g_warning("unknown channel read status, closing");
 588         return false;
 589     }
 590     return true;
 591 }
 592
 593 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
 594 {
 595     GAChannelMethod channel_method;
 596
 597     if (method == NULL) {
 598         method = "virtio-serial";
 599     }
 600
 601     if (path == NULL) {
 602         if (strcmp(method, "virtio-serial") != 0) {
 603             g_critical("must specify a path for this channel");
 604             return false;
 605         }
 606         /* try the default path for the virtio-serial port */
 607         path = QGA_VIRTIO_PATH_DEFAULT;
 608     }
 609
 610     if (strcmp(method, "virtio-serial") == 0) {
 611         s->virtio = true; /* virtio requires special handling in some cases */
 612         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 613     } else if (strcmp(method, "isa-serial") == 0) {
 614         channel_method = GA_CHANNEL_ISA_SERIAL;
 615     } else if (strcmp(method, "unix-listen") == 0) {
 616         channel_method = GA_CHANNEL_UNIX_LISTEN;
 617     } else {
 618         g_critical("unsupported channel method/type: %s", method);
 619         return false;
 620     }
 621
 622     s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
 623     if (!s->channel) {
 624         g_critical("failed to create guest agent channel");
 625         return false;
 626     }
 627
 628     return true;
 629 }
 630
 631 #ifdef _WIN32
 632 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 633                                   LPVOID ctx)
 634 {
 635     DWORD ret = NO_ERROR;
 636     GAService *service = &ga_state->service;
 637
 638     switch (ctrl)
 639     {
 640         case SERVICE_CONTROL_STOP:
 641         case SERVICE_CONTROL_SHUTDOWN:
 642             quit_handler(SIGTERM);
 643             service->status.dwCurrentState = SERVICE_STOP_PENDING;
 644             SetServiceStatus(service->status_handle, &service->status);
 645             break;
 646
 647         default:
 648             ret = ERROR_CALL_NOT_IMPLEMENTED;
 649     }
 650     return ret;
 651 }
 652
 653 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 654 {
 655     GAService *service = &ga_state->service;
 656
 657     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 658         service_ctrl_handler, NULL);
 659
 660     if (service->status_handle == 0) {
 661         g_critical("Failed to register extended requests function!\n");
 662         return;
 663     }
 664
 665     service->status.dwServiceType = SERVICE_WIN32;
 666     service->status.dwCurrentState = SERVICE_RUNNING;
 667     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 668     service->status.dwWin32ExitCode = NO_ERROR;
 669     service->status.dwServiceSpecificExitCode = NO_ERROR;
 670     service->status.dwCheckPoint = 0;
 671     service->status.dwWaitHint = 0;
 672     SetServiceStatus(service->status_handle, &service->status);
 673
 674     g_main_loop_run(ga_state->main_loop);
 675
 676     service->status.dwCurrentState = SERVICE_STOPPED;
 677     SetServiceStatus(service->status_handle, &service->status);
 678 }
 679 #endif
 680
 681 int main(int argc, char **argv)
 682 {
 683     const char *sopt = "hVvdm:p:l:f:b:s:t:";
 684     const char *method = NULL, *path = NULL;
 685     const char *log_filepath = NULL;
 686     const char *pid_filepath = QGA_PIDFILE_DEFAULT;
 687     const char *state_dir = QGA_STATEDIR_DEFAULT;
 688 #ifdef _WIN32
 689     const char *service = NULL;
 690 #endif
 691     const struct option lopt[] = {
 692         { "help", 0, NULL, 'h' },
 693         { "version", 0, NULL, 'V' },
 694         { "logfile", 1, NULL, 'l' },
 695         { "pidfile", 1, NULL, 'f' },
 696         { "verbose", 0, NULL, 'v' },
 697         { "method", 1, NULL, 'm' },
 698         { "path", 1, NULL, 'p' },
 699         { "daemonize", 0, NULL, 'd' },
 700         { "blacklist", 1, NULL, 'b' },
 701 #ifdef _WIN32
 702         { "service", 1, NULL, 's' },
 703 #endif
 704         { "statedir", 1, NULL, 't' },
 705         { NULL, 0, NULL, 0 }
 706     };
 707     int opt_ind = 0, ch, daemonize = 0, i, j, len;
 708     GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
 709     GList *blacklist = NULL;
 710     GAState *s;
 711
 712     module_call_init(MODULE_INIT_QAPI);
 713
 714     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 715         switch (ch) {
 716         case 'm':
 717             method = optarg;
 718             break;
 719         case 'p':
 720             path = optarg;
 721             break;
 722         case 'l':
 723             log_filepath = optarg;
 724             break;
 725         case 'f':
 726             pid_filepath = optarg;
 727             break;
 728         case 't':
 729              state_dir = optarg;
 730              break;
 731         case 'v':
 732             /* enable all log levels */
 733             log_level = G_LOG_LEVEL_MASK;
 734             break;
 735         case 'V':
 736             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
 737             return 0;
 738         case 'd':
 739             daemonize = 1;
 740             break;
 741         case 'b': {
 742             char **list_head, **list;
 743             if (is_help_option(optarg)) {
 744                 list_head = list = qmp_get_command_list();
 745                 while (*list != NULL) {
 746                     printf("%s\n", *list);
 747                     g_free(*list);
 748                     list++;
 749                 }
 750                 g_free(list_head);
 751                 return 0;
 752             }
 753             for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
 754                 if (optarg[i] == ',') {
 755                     optarg[i] = 0;
 756                     blacklist = g_list_append(blacklist, &optarg[j]);
 757                     j = i + 1;
 758                 }
 759             }
 760             if (j < i) {
 761                 blacklist = g_list_append(blacklist, &optarg[j]);
 762             }
 763             break;
 764         }
 765 #ifdef _WIN32
 766         case 's':
 767             service = optarg;
 768             if (strcmp(service, "install") == 0) {
 769                 return ga_install_service(path, log_filepath);
 770             } else if (strcmp(service, "uninstall") == 0) {
 771                 return ga_uninstall_service();
 772             } else {
 773                 printf("Unknown service command.\n");
 774                 return EXIT_FAILURE;
 775             }
 776             break;
 777 #endif
 778         case 'h':
 779             usage(argv[0]);
 780             return 0;
 781         case '?':
 782             g_print("Unknown option, try '%s --help' for more information.\n",
 783                     argv[0]);
 784             return EXIT_FAILURE;
 785         }
 786     }
 787
 788     s = g_malloc0(sizeof(GAState));
 789     s->log_level = log_level;
 790     s->log_file = stderr;
 791     g_log_set_default_handler(ga_log, s);
 792     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
 793     ga_enable_logging(s);
 794     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
 795                                                  state_dir);
 796     s->frozen = false;
 797 #ifndef _WIN32
 798     /* check if a previous instance of qemu-ga exited with filesystems' state
 799      * marked as frozen. this could be a stale value (a non-qemu-ga process
 800      * or reboot may have since unfrozen them), but better to require an
 801      * uneeded unfreeze than to risk hanging on start-up
 802      */
 803     struct stat st;
 804     if (stat(s->state_filepath_isfrozen, &st) == -1) {
 805         /* it's okay if the file doesn't exist, but if we can't access for
 806          * some other reason, such as permissions, there's a configuration
 807          * that needs to be addressed. so just bail now before we get into
 808          * more trouble later
 809          */
 810         if (errno != ENOENT) {
 811             g_critical("unable to access state file at path %s: %s",
 812                        s->state_filepath_isfrozen, strerror(errno));
 813             return EXIT_FAILURE;
 814         }
 815     } else {
 816         g_warning("previous instance appears to have exited with frozen"
 817                   " filesystems. deferring logging/pidfile creation and"
 818                   " disabling non-fsfreeze-safe commands until"
 819                   " guest-fsfreeze-thaw is issued, or filesystems are"
 820                   " manually unfrozen and the file %s is removed",
 821                   s->state_filepath_isfrozen);
 822         s->frozen = true;
 823     }
 824 #endif
 825
 826     if (ga_is_frozen(s)) {
 827         if (daemonize) {
 828             /* delay opening/locking of pidfile till filesystem are unfrozen */
 829             s->deferred_options.pid_filepath = pid_filepath;
 830             become_daemon(NULL);
 831         }
 832         if (log_filepath) {
 833             /* delay opening the log file till filesystems are unfrozen */
 834             s->deferred_options.log_filepath = log_filepath;
 835         }
 836         ga_disable_logging(s);
 837         ga_disable_non_whitelisted();
 838     } else {
 839         if (daemonize) {
 840             become_daemon(pid_filepath);
 841         }
 842         if (log_filepath) {
 843             FILE *log_file = fopen(log_filepath, "a");
 844             if (!log_file) {
 845                 g_critical("unable to open specified log file: %s",
 846                            strerror(errno));
 847                 goto out_bad;
 848             }
 849             s->log_file = log_file;
 850         }
 851     }
 852
 853     if (blacklist) {
 854         s->blacklist = blacklist;
 855         do {
 856             g_debug("disabling command: %s", (char *)blacklist->data);
 857             qmp_disable_command(blacklist->data);
 858             blacklist = g_list_next(blacklist);
 859         } while (blacklist);
 860     }
 861     s->command_state = ga_command_state_new();
 862     ga_command_state_init(s, s->command_state);
 863     ga_command_state_init_all(s->command_state);
 864     json_message_parser_init(&s->parser, process_event);
 865     ga_state = s;
 866 #ifndef _WIN32
 867     if (!register_signal_handlers()) {
 868         g_critical("failed to register signal handlers");
 869         goto out_bad;
 870     }
 871 #endif
 872
 873     s->main_loop = g_main_loop_new(NULL, false);
 874     if (!channel_init(ga_state, method, path)) {
 875         g_critical("failed to initialize guest agent channel");
 876         goto out_bad;
 877     }
 878 #ifndef _WIN32
 879     g_main_loop_run(ga_state->main_loop);
 880 #else
 881     if (daemonize) {
 882         SERVICE_TABLE_ENTRY service_table[] = {
 883             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
 884         StartServiceCtrlDispatcher(service_table);
 885     } else {
 886         g_main_loop_run(ga_state->main_loop);
 887     }
 888 #endif
 889
 890     ga_command_state_cleanup_all(ga_state->command_state);
 891     ga_channel_free(ga_state->channel);
 892
 893     if (daemonize) {
 894         unlink(pid_filepath);
 895     }
 896     return 0;
 897
 898 out_bad:
 899     if (daemonize) {
 900         unlink(pid_filepath);
 901     }
 902     return EXIT_FAILURE;
 903 }