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
  14 #include "qemu/osdep.h"
  15 #include <getopt.h>
  16 #include <glib/gstdio.h>
  17 #ifndef _WIN32
  18 #include <syslog.h>
  19 #include <sys/wait.h>
  20 #endif
  21 #include "qemu/help-texts.h"
  22 #include "qapi/qmp/json-parser.h"
  23 #include "qapi/qmp/qdict.h"
  24 #include "qapi/qmp/qjson.h"
  25 #include "guest-agent-core.h"
  26 #include "qga-qapi-init-commands.h"
  27 #include "qapi/qmp/qerror.h"
  28 #include "qapi/error.h"
  29 #include "channel.h"
  30 #include "qemu/cutils.h"
  31 #include "qemu/help_option.h"
  32 #include "qemu/sockets.h"
  33 #include "qemu/systemd.h"
  34 #include "qemu-version.h"
  35 #ifdef _WIN32
  36 #include <dbt.h>
  37 #include "qga/service-win32.h"
  38 #include "qga/vss-win32.h"
  39 #endif
  40 #ifdef __linux__
  41 #include <linux/fs.h>
  42 #ifdef FIFREEZE
  43 #define CONFIG_FSFREEZE
  44 #endif
  45 #endif
  46
  47 #ifndef _WIN32
  48 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
  49 #define QGA_STATE_RELATIVE_DIR  "run"
  50 #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
  51 #else
  52 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
  53 #define QGA_STATE_RELATIVE_DIR  "qemu-ga"
  54 #define QGA_SERIAL_PATH_DEFAULT "COM1"
  55 #endif
  56 #ifdef CONFIG_FSFREEZE
  57 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
  58 #endif
  59 #define QGA_SENTINEL_BYTE 0xFF
  60 #define QGA_CONF_DEFAULT CONFIG_QEMU_CONFDIR G_DIR_SEPARATOR_S "qemu-ga.conf"
  61 #define QGA_RETRY_INTERVAL 5
  62
  63 static struct {
  64     const char *state_dir;
  65     const char *pidfile;
  66 } dfl_pathnames;
  67
  68 typedef struct GAPersistentState {
  69 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
  70     int64_t fd_counter;
  71 } GAPersistentState;
  72
  73 typedef struct GAConfig GAConfig;
  74
  75 struct GAState {
  76     JSONMessageParser parser;
  77     GMainLoop *main_loop;
  78     GAChannel *channel;
  79     bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
  80     GACommandState *command_state;
  81     GLogLevelFlags log_level;
  82     FILE *log_file;
  83     bool logging_enabled;
  84 #ifdef _WIN32
  85     GAService service;
  86     HANDLE wakeup_event;
  87 #endif
  88     bool delimit_response;
  89     bool frozen;
  90     GList *blockedrpcs;
  91     char *state_filepath_isfrozen;
  92     struct {
  93         const char *log_filepath;
  94         const char *pid_filepath;
  95     } deferred_options;
  96 #ifdef CONFIG_FSFREEZE
  97     const char *fsfreeze_hook;
  98 #endif
  99     gchar *pstate_filepath;
 100     GAPersistentState pstate;
 101     GAConfig *config;
 102     int socket_activation;
 103     bool force_exit;
 104 };
 105
 106 struct GAState *ga_state;
 107 QmpCommandList ga_commands;
 108
 109 /* commands that are safe to issue while filesystems are frozen */
 110 static const char *ga_freeze_allowlist[] = {
 111     "guest-ping",
 112     "guest-info",
 113     "guest-sync",
 114     "guest-sync-delimited",
 115     "guest-fsfreeze-status",
 116     "guest-fsfreeze-thaw",
 117     NULL
 118 };
 119
 120 #ifdef _WIN32
 121 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 122                                   LPVOID ctx);
 123 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data);
 124 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
 125 #endif
 126 static int run_agent(GAState *s);
 127 static void stop_agent(GAState *s, bool requested);
 128
 129 static void
 130 init_dfl_pathnames(void)
 131 {
 132     g_autofree char *state = qemu_get_local_state_dir();
 133
 134     g_assert(dfl_pathnames.state_dir == NULL);
 135     g_assert(dfl_pathnames.pidfile == NULL);
 136     dfl_pathnames.state_dir = g_build_filename(state, QGA_STATE_RELATIVE_DIR, NULL);
 137     dfl_pathnames.pidfile = g_build_filename(state, QGA_STATE_RELATIVE_DIR, "qemu-ga.pid", NULL);
 138 }
 139
 140 static void quit_handler(int sig)
 141 {
 142     /* if we're frozen, don't exit unless we're absolutely forced to,
 143      * because it's basically impossible for graceful exit to complete
 144      * unless all log/pid files are on unfreezable filesystems. there's
 145      * also a very likely chance killing the agent before unfreezing
 146      * the filesystems is a mistake (or will be viewed as one later).
 147      * On Windows the freeze interval is limited to 10 seconds, so
 148      * we should quit, but first we should wait for the timeout, thaw
 149      * the filesystem and quit.
 150      */
 151     if (ga_is_frozen(ga_state)) {
 152 #ifdef _WIN32
 153         int i = 0;
 154         Error *err = NULL;
 155         HANDLE hEventTimeout;
 156
 157         g_debug("Thawing filesystems before exiting");
 158
 159         hEventTimeout = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_TIMEOUT);
 160         if (hEventTimeout) {
 161             WaitForSingleObject(hEventTimeout, 0);
 162             CloseHandle(hEventTimeout);
 163         }
 164         qga_vss_fsfreeze(&i, false, NULL, &err);
 165         if (err) {
 166             g_debug("Error unfreezing filesystems prior to exiting: %s",
 167                 error_get_pretty(err));
 168             error_free(err);
 169         }
 170 #else
 171         return;
 172 #endif
 173     }
 174     g_debug("received signal num %d, quitting", sig);
 175
 176     stop_agent(ga_state, true);
 177 }
 178
 179 #ifndef _WIN32
 180 static gboolean register_signal_handlers(void)
 181 {
 182     struct sigaction sigact;
 183     int ret;
 184
 185     memset(&sigact, 0, sizeof(struct sigaction));
 186     sigact.sa_handler = quit_handler;
 187
 188     ret = sigaction(SIGINT, &sigact, NULL);
 189     if (ret == -1) {
 190         g_error("error configuring signal handler: %s", strerror(errno));
 191     }
 192     ret = sigaction(SIGTERM, &sigact, NULL);
 193     if (ret == -1) {
 194         g_error("error configuring signal handler: %s", strerror(errno));
 195     }
 196
 197     sigact.sa_handler = SIG_IGN;
 198     if (sigaction(SIGPIPE, &sigact, NULL) != 0) {
 199         g_error("error configuring SIGPIPE signal handler: %s",
 200                 strerror(errno));
 201     }
 202
 203     return true;
 204 }
 205
 206 /* TODO: use this in place of all post-fork() fclose(std*) callers */
 207 void reopen_fd_to_null(int fd)
 208 {
 209     int nullfd;
 210
 211     nullfd = open("/dev/null", O_RDWR);
 212     if (nullfd < 0) {
 213         return;
 214     }
 215
 216     dup2(nullfd, fd);
 217
 218     if (nullfd != fd) {
 219         close(nullfd);
 220     }
 221 }
 222 #endif
 223
 224 static void usage(const char *cmd)
 225 {
 226 #ifdef CONFIG_FSFREEZE
 227     g_autofree char *fsfreeze_hook = get_relocated_path(QGA_FSFREEZE_HOOK_DEFAULT);
 228 #endif
 229
 230     printf(
 231 "Usage: %s [-m <method> -p <path>] [<options>]\n"
 232 "QEMU Guest Agent " QEMU_FULL_VERSION "\n"
 233 QEMU_COPYRIGHT "\n"
 234 "\n"
 235 "  -m, --method      transport method: one of unix-listen, virtio-serial,\n"
 236 "                    isa-serial, or vsock-listen (virtio-serial is the default)\n"
 237 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
 238 "                    %s,\n"
 239 "                    the default for isa-serial is:\n"
 240 "                    %s).\n"
 241 "                    Socket addresses for vsock-listen are written as\n"
 242 "                    <cid>:<port>.\n"
 243 "  -l, --logfile     set logfile path, logs to stderr by default\n"
 244 "  -f, --pidfile     specify pidfile (default is %s)\n"
 245 #ifdef CONFIG_FSFREEZE
 246 "  -F, --fsfreeze-hook\n"
 247 "                    enable fsfreeze hook. Accepts an optional argument that\n"
 248 "                    specifies script to run on freeze/thaw. Script will be\n"
 249 "                    called with 'freeze'/'thaw' arguments accordingly.\n"
 250 "                    (default is %s)\n"
 251 "                    If using -F with an argument, do not follow -F with a\n"
 252 "                    space.\n"
 253 "                    (for example: -F/var/run/fsfreezehook.sh)\n"
 254 #endif
 255 "  -t, --statedir    specify dir to store state information (absolute paths\n"
 256 "                    only, default is %s)\n"
 257 "  -v, --verbose     log extra debugging information\n"
 258 "  -V, --version     print version information and exit\n"
 259 "  -d, --daemonize   become a daemon\n"
 260 #ifdef _WIN32
 261 "  -s, --service     service commands: install, uninstall, vss-install, vss-uninstall\n"
 262 #endif
 263 "  -b, --block-rpcs  comma-separated list of RPCs to disable (no spaces,\n"
 264 "                    use \"help\" to list available RPCs)\n"
 265 "  -D, --dump-conf   dump a qemu-ga config file based on current config\n"
 266 "                    options / command-line parameters to stdout\n"
 267 "  -r, --retry-path  attempt re-opening path if it's unavailable or closed\n"
 268 "                    due to an error which may be recoverable in the future\n"
 269 "                    (virtio-serial driver re-install, serial device hot\n"
 270 "                    plug/unplug, etc.)\n"
 271 "  -h, --help        display this help and exit\n"
 272 "\n"
 273 QEMU_HELP_BOTTOM "\n"
 274     , cmd, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT,
 275     dfl_pathnames.pidfile,
 276 #ifdef CONFIG_FSFREEZE
 277     fsfreeze_hook,
 278 #endif
 279     dfl_pathnames.state_dir);
 280 }
 281
 282 static const char *ga_log_level_str(GLogLevelFlags level)
 283 {
 284     switch (level & G_LOG_LEVEL_MASK) {
 285     case G_LOG_LEVEL_ERROR:
 286         return "error";
 287     case G_LOG_LEVEL_CRITICAL:
 288         return "critical";
 289     case G_LOG_LEVEL_WARNING:
 290         return "warning";
 291     case G_LOG_LEVEL_MESSAGE:
 292         return "message";
 293     case G_LOG_LEVEL_INFO:
 294         return "info";
 295     case G_LOG_LEVEL_DEBUG:
 296         return "debug";
 297     default:
 298         return "user";
 299     }
 300 }
 301
 302 bool ga_logging_enabled(GAState *s)
 303 {
 304     return s->logging_enabled;
 305 }
 306
 307 void ga_disable_logging(GAState *s)
 308 {
 309     s->logging_enabled = false;
 310 }
 311
 312 void ga_enable_logging(GAState *s)
 313 {
 314     s->logging_enabled = true;
 315 }
 316
 317 static void ga_log(const gchar *domain, GLogLevelFlags level,
 318                    const gchar *msg, gpointer opaque)
 319 {
 320     GAState *s = opaque;
 321     const char *level_str = ga_log_level_str(level);
 322
 323     if (!ga_logging_enabled(s)) {
 324         return;
 325     }
 326
 327     level &= G_LOG_LEVEL_MASK;
 328 #ifndef _WIN32
 329     if (g_strcmp0(domain, "syslog") == 0) {
 330         syslog(LOG_INFO, "%s: %s", level_str, msg);
 331     } else if (level & s->log_level) {
 332 #else
 333     if (level & s->log_level) {
 334 #endif
 335         g_autoptr(GDateTime) now = g_date_time_new_now_utc();
 336         g_autofree char *nowstr = g_date_time_format(now, "%s.%f");
 337         fprintf(s->log_file, "%s: %s: %s\n", nowstr, level_str, msg);
 338         fflush(s->log_file);
 339     }
 340 }
 341
 342 void ga_set_response_delimited(GAState *s)
 343 {
 344     s->delimit_response = true;
 345 }
 346
 347 static FILE *ga_open_logfile(const char *logfile)
 348 {
 349     FILE *f;
 350
 351     f = fopen(logfile, "a");
 352     if (!f) {
 353         return NULL;
 354     }
 355
 356     qemu_set_cloexec(fileno(f));
 357     return f;
 358 }
 359
 360 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
 361 {
 362     return strcmp(str1, str2);
 363 }
 364
 365 /* disable commands that aren't safe for fsfreeze */
 366 static void ga_disable_not_allowed(const QmpCommand *cmd, void *opaque)
 367 {
 368     bool allowed = false;
 369     int i = 0;
 370     const char *name = qmp_command_name(cmd);
 371
 372     while (ga_freeze_allowlist[i] != NULL) {
 373         if (strcmp(name, ga_freeze_allowlist[i]) == 0) {
 374             allowed = true;
 375         }
 376         i++;
 377     }
 378     if (!allowed) {
 379         g_debug("disabling command: %s", name);
 380         qmp_disable_command(&ga_commands, name, "the agent is in frozen state");
 381     }
 382 }
 383
 384 /* [re-]enable all commands, except those explicitly blocked by user */
 385 static void ga_enable_non_blocked(const QmpCommand *cmd, void *opaque)
 386 {
 387     GList *blockedrpcs = opaque;
 388     const char *name = qmp_command_name(cmd);
 389
 390     if (g_list_find_custom(blockedrpcs, name, ga_strcmp) == NULL &&
 391         !qmp_command_is_enabled(cmd)) {
 392         g_debug("enabling command: %s", name);
 393         qmp_enable_command(&ga_commands, name);
 394     }
 395 }
 396
 397 static bool ga_create_file(const char *path)
 398 {
 399     int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
 400     if (fd == -1) {
 401         g_warning("unable to open/create file %s: %s", path, strerror(errno));
 402         return false;
 403     }
 404     close(fd);
 405     return true;
 406 }
 407
 408 static bool ga_delete_file(const char *path)
 409 {
 410     int ret = unlink(path);
 411     if (ret == -1) {
 412         g_warning("unable to delete file: %s: %s", path, strerror(errno));
 413         return false;
 414     }
 415
 416     return true;
 417 }
 418
 419 bool ga_is_frozen(GAState *s)
 420 {
 421     return s->frozen;
 422 }
 423
 424 void ga_set_frozen(GAState *s)
 425 {
 426     if (ga_is_frozen(s)) {
 427         return;
 428     }
 429     /* disable all forbidden (for frozen state) commands */
 430     qmp_for_each_command(&ga_commands, ga_disable_not_allowed, NULL);
 431     g_warning("disabling logging due to filesystem freeze");
 432     ga_disable_logging(s);
 433     s->frozen = true;
 434     if (!ga_create_file(s->state_filepath_isfrozen)) {
 435         g_warning("unable to create %s, fsfreeze may not function properly",
 436                   s->state_filepath_isfrozen);
 437     }
 438 }
 439
 440 void ga_unset_frozen(GAState *s)
 441 {
 442     if (!ga_is_frozen(s)) {
 443         return;
 444     }
 445
 446     /* if we delayed creation/opening of pid/log files due to being
 447      * in a frozen state at start up, do it now
 448      */
 449     if (s->deferred_options.log_filepath) {
 450         s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
 451         if (!s->log_file) {
 452             s->log_file = stderr;
 453         }
 454         s->deferred_options.log_filepath = NULL;
 455     }
 456     ga_enable_logging(s);
 457     g_warning("logging re-enabled due to filesystem unfreeze");
 458     if (s->deferred_options.pid_filepath) {
 459         Error *err = NULL;
 460
 461         if (!qemu_write_pidfile(s->deferred_options.pid_filepath, &err)) {
 462             g_warning("%s", error_get_pretty(err));
 463             error_free(err);
 464         }
 465         s->deferred_options.pid_filepath = NULL;
 466     }
 467
 468     /* enable all disabled, non-blocked commands */
 469     qmp_for_each_command(&ga_commands, ga_enable_non_blocked, s->blockedrpcs);
 470     s->frozen = false;
 471     if (!ga_delete_file(s->state_filepath_isfrozen)) {
 472         g_warning("unable to delete %s, fsfreeze may not function properly",
 473                   s->state_filepath_isfrozen);
 474     }
 475 }
 476
 477 #ifdef CONFIG_FSFREEZE
 478 const char *ga_fsfreeze_hook(GAState *s)
 479 {
 480     return s->fsfreeze_hook;
 481 }
 482 #endif
 483
 484 static void become_daemon(const char *pidfile)
 485 {
 486 #ifndef _WIN32
 487     pid_t pid, sid;
 488
 489     pid = fork();
 490     if (pid < 0) {
 491         exit(EXIT_FAILURE);
 492     }
 493     if (pid > 0) {
 494         exit(EXIT_SUCCESS);
 495     }
 496
 497     if (pidfile) {
 498         Error *err = NULL;
 499
 500         if (!qemu_write_pidfile(pidfile, &err)) {
 501             g_critical("%s", error_get_pretty(err));
 502             error_free(err);
 503             exit(EXIT_FAILURE);
 504         }
 505     }
 506
 507     umask(S_IRWXG | S_IRWXO);
 508     sid = setsid();
 509     if (sid < 0) {
 510         goto fail;
 511     }
 512     if ((chdir("/")) < 0) {
 513         goto fail;
 514     }
 515
 516     reopen_fd_to_null(STDIN_FILENO);
 517     reopen_fd_to_null(STDOUT_FILENO);
 518     reopen_fd_to_null(STDERR_FILENO);
 519     return;
 520
 521 fail:
 522     if (pidfile) {
 523         unlink(pidfile);
 524     }
 525     g_critical("failed to daemonize");
 526     exit(EXIT_FAILURE);
 527 #endif
 528 }
 529
 530 static int send_response(GAState *s, const QDict *rsp)
 531 {
 532     GString *response;
 533     GIOStatus status;
 534
 535     g_assert(s->channel);
 536
 537     if (!rsp) {
 538         return 0;
 539     }
 540
 541     response = qobject_to_json(QOBJECT(rsp));
 542     if (!response) {
 543         return -EINVAL;
 544     }
 545
 546     if (s->delimit_response) {
 547         s->delimit_response = false;
 548         g_string_prepend_c(response, QGA_SENTINEL_BYTE);
 549     }
 550
 551     g_string_append_c(response, '\n');
 552     status = ga_channel_write_all(s->channel, response->str, response->len);
 553     g_string_free(response, true);
 554     if (status != G_IO_STATUS_NORMAL) {
 555         return -EIO;
 556     }
 557
 558     return 0;
 559 }
 560
 561 /* handle requests/control events coming in over the channel */
 562 static void process_event(void *opaque, QObject *obj, Error *err)
 563 {
 564     GAState *s = opaque;
 565     QDict *rsp;
 566     int ret;
 567
 568     g_debug("process_event: called");
 569     assert(!obj != !err);
 570     if (err) {
 571         rsp = qmp_error_response(err);
 572         goto end;
 573     }
 574
 575     g_debug("processing command");
 576     rsp = qmp_dispatch(&ga_commands, obj, false, NULL);
 577
 578 end:
 579     ret = send_response(s, rsp);
 580     if (ret < 0) {
 581         g_warning("error sending error response: %s", strerror(-ret));
 582     }
 583     qobject_unref(rsp);
 584     qobject_unref(obj);
 585 }
 586
 587 /* false return signals GAChannel to close the current client connection */
 588 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 589 {
 590     GAState *s = data;
 591     gchar buf[QGA_READ_COUNT_DEFAULT + 1];
 592     gsize count;
 593     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 594     switch (status) {
 595     case G_IO_STATUS_ERROR:
 596         g_warning("error reading channel");
 597         stop_agent(s, false);
 598         return false;
 599     case G_IO_STATUS_NORMAL:
 600         buf[count] = 0;
 601         g_debug("read data, count: %d, data: %s", (int)count, buf);
 602         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 603         break;
 604     case G_IO_STATUS_EOF:
 605         g_debug("received EOF");
 606         if (!s->virtio) {
 607             return false;
 608         }
 609         /* fall through */
 610     case G_IO_STATUS_AGAIN:
 611         /* virtio causes us to spin here when no process is attached to
 612          * host-side chardev. sleep a bit to mitigate this
 613          */
 614         if (s->virtio) {
 615             g_usleep(G_USEC_PER_SEC / 10);
 616         }
 617         return true;
 618     default:
 619         g_warning("unknown channel read status, closing");
 620         return false;
 621     }
 622     return true;
 623 }
 624
 625 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path,
 626                              int listen_fd)
 627 {
 628     GAChannelMethod channel_method;
 629
 630     if (strcmp(method, "virtio-serial") == 0) {
 631         s->virtio = true; /* virtio requires special handling in some cases */
 632         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 633     } else if (strcmp(method, "isa-serial") == 0) {
 634         channel_method = GA_CHANNEL_ISA_SERIAL;
 635     } else if (strcmp(method, "unix-listen") == 0) {
 636         channel_method = GA_CHANNEL_UNIX_LISTEN;
 637     } else if (strcmp(method, "vsock-listen") == 0) {
 638         channel_method = GA_CHANNEL_VSOCK_LISTEN;
 639     } else {
 640         g_critical("unsupported channel method/type: %s", method);
 641         return false;
 642     }
 643
 644     s->channel = ga_channel_new(channel_method, path, listen_fd,
 645                                 channel_event_cb, s);
 646     if (!s->channel) {
 647         g_critical("failed to create guest agent channel");
 648         return false;
 649     }
 650
 651     return true;
 652 }
 653
 654 #ifdef _WIN32
 655 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data)
 656 {
 657     DWORD ret = NO_ERROR;
 658     PDEV_BROADCAST_HDR broadcast_header = (PDEV_BROADCAST_HDR)data;
 659
 660     if (broadcast_header->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE) {
 661         switch (type) {
 662             /* Device inserted */
 663         case DBT_DEVICEARRIVAL:
 664             /* Start QEMU-ga's service */
 665             if (!SetEvent(ga_state->wakeup_event)) {
 666                 ret = GetLastError();
 667             }
 668             break;
 669             /* Device removed */
 670         case DBT_DEVICEQUERYREMOVE:
 671         case DBT_DEVICEREMOVEPENDING:
 672         case DBT_DEVICEREMOVECOMPLETE:
 673             /* Stop QEMU-ga's service */
 674             if (!ResetEvent(ga_state->wakeup_event)) {
 675                 ret = GetLastError();
 676             }
 677             break;
 678         default:
 679             ret = ERROR_CALL_NOT_IMPLEMENTED;
 680         }
 681     }
 682     return ret;
 683 }
 684
 685 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 686                                   LPVOID ctx)
 687 {
 688     DWORD ret = NO_ERROR;
 689     GAService *service = &ga_state->service;
 690
 691     switch (ctrl) {
 692     case SERVICE_CONTROL_STOP:
 693     case SERVICE_CONTROL_SHUTDOWN:
 694         quit_handler(SIGTERM);
 695         SetEvent(ga_state->wakeup_event);
 696         service->status.dwCurrentState = SERVICE_STOP_PENDING;
 697         SetServiceStatus(service->status_handle, &service->status);
 698         break;
 699     case SERVICE_CONTROL_DEVICEEVENT:
 700         handle_serial_device_events(type, data);
 701         break;
 702
 703     default:
 704         ret = ERROR_CALL_NOT_IMPLEMENTED;
 705     }
 706     return ret;
 707 }
 708
 709 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 710 {
 711     GAService *service = &ga_state->service;
 712
 713     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 714         service_ctrl_handler, NULL);
 715
 716     if (service->status_handle == 0) {
 717         g_critical("Failed to register extended requests function!\n");
 718         return;
 719     }
 720
 721     service->status.dwServiceType = SERVICE_WIN32;
 722     service->status.dwCurrentState = SERVICE_RUNNING;
 723     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 724     service->status.dwWin32ExitCode = NO_ERROR;
 725     service->status.dwServiceSpecificExitCode = NO_ERROR;
 726     service->status.dwCheckPoint = 0;
 727     service->status.dwWaitHint = 0;
 728     DEV_BROADCAST_DEVICEINTERFACE notification_filter;
 729     ZeroMemory(&notification_filter, sizeof(notification_filter));
 730     notification_filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
 731     notification_filter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
 732     notification_filter.dbcc_classguid = GUID_VIOSERIAL_PORT;
 733
 734     service->device_notification_handle =
 735         RegisterDeviceNotification(service->status_handle,
 736             &notification_filter, DEVICE_NOTIFY_SERVICE_HANDLE);
 737     if (!service->device_notification_handle) {
 738         g_critical("Failed to register device notification handle!\n");
 739         return;
 740     }
 741     SetServiceStatus(service->status_handle, &service->status);
 742
 743     run_agent(ga_state);
 744
 745     UnregisterDeviceNotification(service->device_notification_handle);
 746     service->status.dwCurrentState = SERVICE_STOPPED;
 747     SetServiceStatus(service->status_handle, &service->status);
 748 }
 749 #endif
 750
 751 static void set_persistent_state_defaults(GAPersistentState *pstate)
 752 {
 753     g_assert(pstate);
 754     pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
 755 }
 756
 757 static void persistent_state_from_keyfile(GAPersistentState *pstate,
 758                                           GKeyFile *keyfile)
 759 {
 760     g_assert(pstate);
 761     g_assert(keyfile);
 762     /* if any fields are missing, either because the file was tampered with
 763      * by agents of chaos, or because the field wasn't present at the time the
 764      * file was created, the best we can ever do is start over with the default
 765      * values. so load them now, and ignore any errors in accessing key-value
 766      * pairs
 767      */
 768     set_persistent_state_defaults(pstate);
 769
 770     if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
 771         pstate->fd_counter =
 772             g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
 773     }
 774 }
 775
 776 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
 777                                         GKeyFile *keyfile)
 778 {
 779     g_assert(pstate);
 780     g_assert(keyfile);
 781
 782     g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
 783 }
 784
 785 static gboolean write_persistent_state(const GAPersistentState *pstate,
 786                                        const gchar *path)
 787 {
 788     GKeyFile *keyfile = g_key_file_new();
 789     GError *gerr = NULL;
 790     gboolean ret = true;
 791     gchar *data = NULL;
 792     gsize data_len;
 793
 794     g_assert(pstate);
 795
 796     persistent_state_to_keyfile(pstate, keyfile);
 797     data = g_key_file_to_data(keyfile, &data_len, &gerr);
 798     if (gerr) {
 799         g_critical("failed to convert persistent state to string: %s",
 800                    gerr->message);
 801         ret = false;
 802         goto out;
 803     }
 804
 805     g_file_set_contents(path, data, data_len, &gerr);
 806     if (gerr) {
 807         g_critical("failed to write persistent state to %s: %s",
 808                     path, gerr->message);
 809         ret = false;
 810         goto out;
 811     }
 812
 813 out:
 814     if (gerr) {
 815         g_error_free(gerr);
 816     }
 817     if (keyfile) {
 818         g_key_file_free(keyfile);
 819     }
 820     g_free(data);
 821     return ret;
 822 }
 823
 824 static gboolean read_persistent_state(GAPersistentState *pstate,
 825                                       const gchar *path, gboolean frozen)
 826 {
 827     GKeyFile *keyfile = NULL;
 828     GError *gerr = NULL;
 829     struct stat st;
 830     gboolean ret = true;
 831
 832     g_assert(pstate);
 833
 834     if (stat(path, &st) == -1) {
 835         /* it's okay if state file doesn't exist, but any other error
 836          * indicates a permissions issue or some other misconfiguration
 837          * that we likely won't be able to recover from.
 838          */
 839         if (errno != ENOENT) {
 840             g_critical("unable to access state file at path %s: %s",
 841                        path, strerror(errno));
 842             ret = false;
 843             goto out;
 844         }
 845
 846         /* file doesn't exist. initialize state to default values and
 847          * attempt to save now. (we could wait till later when we have
 848          * modified state we need to commit, but if there's a problem,
 849          * such as a missing parent directory, we want to catch it now)
 850          *
 851          * there is a potential scenario where someone either managed to
 852          * update the agent from a version that didn't use a key store
 853          * while qemu-ga thought the filesystem was frozen, or
 854          * deleted the key store prior to issuing a fsfreeze, prior
 855          * to restarting the agent. in this case we go ahead and defer
 856          * initial creation till we actually have modified state to
 857          * write, otherwise fail to recover from freeze.
 858          */
 859         set_persistent_state_defaults(pstate);
 860         if (!frozen) {
 861             ret = write_persistent_state(pstate, path);
 862             if (!ret) {
 863                 g_critical("unable to create state file at path %s", path);
 864                 ret = false;
 865                 goto out;
 866             }
 867         }
 868         ret = true;
 869         goto out;
 870     }
 871
 872     keyfile = g_key_file_new();
 873     g_key_file_load_from_file(keyfile, path, 0, &gerr);
 874     if (gerr) {
 875         g_critical("error loading persistent state from path: %s, %s",
 876                    path, gerr->message);
 877         ret = false;
 878         goto out;
 879     }
 880
 881     persistent_state_from_keyfile(pstate, keyfile);
 882
 883 out:
 884     if (keyfile) {
 885         g_key_file_free(keyfile);
 886     }
 887     if (gerr) {
 888         g_error_free(gerr);
 889     }
 890
 891     return ret;
 892 }
 893
 894 int64_t ga_get_fd_handle(GAState *s, Error **errp)
 895 {
 896     int64_t handle;
 897
 898     g_assert(s->pstate_filepath);
 899     /*
 900      * We block commands and avoid operations that potentially require
 901      * writing to disk when we're in a frozen state. this includes opening
 902      * new files, so we should never get here in that situation
 903      */
 904     g_assert(!ga_is_frozen(s));
 905
 906     handle = s->pstate.fd_counter++;
 907
 908     /* This should never happen on a reasonable timeframe, as guest-file-open
 909      * would have to be issued 2^63 times */
 910     if (s->pstate.fd_counter == INT64_MAX) {
 911         abort();
 912     }
 913
 914     if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
 915         error_setg(errp, "failed to commit persistent state to disk");
 916         return -1;
 917     }
 918
 919     return handle;
 920 }
 921
 922 static void ga_print_cmd(const QmpCommand *cmd, void *opaque)
 923 {
 924     printf("%s\n", qmp_command_name(cmd));
 925 }
 926
 927 static GList *split_list(const gchar *str, const gchar *delim)
 928 {
 929     GList *list = NULL;
 930     int i;
 931     gchar **strv;
 932
 933     strv = g_strsplit(str, delim, -1);
 934     for (i = 0; strv[i]; i++) {
 935         list = g_list_prepend(list, strv[i]);
 936     }
 937     g_free(strv);
 938
 939     return list;
 940 }
 941
 942 struct GAConfig {
 943     char *channel_path;
 944     char *method;
 945     char *log_filepath;
 946     char *pid_filepath;
 947 #ifdef CONFIG_FSFREEZE
 948     char *fsfreeze_hook;
 949 #endif
 950     char *state_dir;
 951 #ifdef _WIN32
 952     const char *service;
 953 #endif
 954     gchar *bliststr; /* blockedrpcs may point to this string */
 955     GList *blockedrpcs;
 956     int daemonize;
 957     GLogLevelFlags log_level;
 958     int dumpconf;
 959     bool retry_path;
 960 };
 961
 962 static void config_load(GAConfig *config)
 963 {
 964     GError *gerr = NULL;
 965     GKeyFile *keyfile;
 966     g_autofree char *conf = g_strdup(g_getenv("QGA_CONF")) ?: get_relocated_path(QGA_CONF_DEFAULT);
 967     const gchar *blockrpcs_key = "block-rpcs";
 968
 969     /* read system config */
 970     keyfile = g_key_file_new();
 971     if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
 972         goto end;
 973     }
 974     if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
 975         config->daemonize =
 976             g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
 977     }
 978     if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
 979         config->method =
 980             g_key_file_get_string(keyfile, "general", "method", &gerr);
 981     }
 982     if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
 983         config->channel_path =
 984             g_key_file_get_string(keyfile, "general", "path", &gerr);
 985     }
 986     if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
 987         config->log_filepath =
 988             g_key_file_get_string(keyfile, "general", "logfile", &gerr);
 989     }
 990     if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
 991         config->pid_filepath =
 992             g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
 993     }
 994 #ifdef CONFIG_FSFREEZE
 995     if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
 996         config->fsfreeze_hook =
 997             g_key_file_get_string(keyfile,
 998                                   "general", "fsfreeze-hook", &gerr);
 999     }
1000 #endif
1001     if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
1002         config->state_dir =
1003             g_key_file_get_string(keyfile, "general", "statedir", &gerr);
1004     }
1005     if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
1006         g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
1007         /* enable all log levels */
1008         config->log_level = G_LOG_LEVEL_MASK;
1009     }
1010     if (g_key_file_has_key(keyfile, "general", "retry-path", NULL)) {
1011         config->retry_path =
1012             g_key_file_get_boolean(keyfile, "general", "retry-path", &gerr);
1013     }
1014
1015     if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
1016         g_warning("config using deprecated 'blacklist' key, should be replaced"
1017                   " with the 'block-rpcs' key.");
1018         blockrpcs_key = "blacklist";
1019     }
1020     if (g_key_file_has_key(keyfile, "general", blockrpcs_key, NULL)) {
1021         config->bliststr =
1022             g_key_file_get_string(keyfile, "general", blockrpcs_key, &gerr);
1023         config->blockedrpcs = g_list_concat(config->blockedrpcs,
1024                                           split_list(config->bliststr, ","));
1025     }
1026
1027 end:
1028     g_key_file_free(keyfile);
1029     if (gerr &&
1030         !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
1031         g_critical("error loading configuration from path: %s, %s",
1032                    conf, gerr->message);
1033         exit(EXIT_FAILURE);
1034     }
1035     g_clear_error(&gerr);
1036 }
1037
1038 static gchar *list_join(GList *list, const gchar separator)
1039 {
1040     GString *str = g_string_new("");
1041
1042     while (list) {
1043         str = g_string_append(str, (gchar *)list->data);
1044         list = g_list_next(list);
1045         if (list) {
1046             str = g_string_append_c(str, separator);
1047         }
1048     }
1049
1050     return g_string_free(str, FALSE);
1051 }
1052
1053 static void config_dump(GAConfig *config)
1054 {
1055     GError *error = NULL;
1056     GKeyFile *keyfile;
1057     gchar *tmp;
1058
1059     keyfile = g_key_file_new();
1060     g_assert(keyfile);
1061
1062     g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1063     g_key_file_set_string(keyfile, "general", "method", config->method);
1064     if (config->channel_path) {
1065         g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1066     }
1067     if (config->log_filepath) {
1068         g_key_file_set_string(keyfile, "general", "logfile",
1069                               config->log_filepath);
1070     }
1071     g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1072 #ifdef CONFIG_FSFREEZE
1073     if (config->fsfreeze_hook) {
1074         g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1075                               config->fsfreeze_hook);
1076     }
1077 #endif
1078     g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1079     g_key_file_set_boolean(keyfile, "general", "verbose",
1080                            config->log_level == G_LOG_LEVEL_MASK);
1081     g_key_file_set_boolean(keyfile, "general", "retry-path",
1082                            config->retry_path);
1083     tmp = list_join(config->blockedrpcs, ',');
1084     g_key_file_set_string(keyfile, "general", "block-rpcs", tmp);
1085     g_free(tmp);
1086
1087     tmp = g_key_file_to_data(keyfile, NULL, &error);
1088     if (error) {
1089         g_critical("Failed to dump keyfile: %s", error->message);
1090         g_clear_error(&error);
1091     } else {
1092         printf("%s", tmp);
1093     }
1094
1095     g_free(tmp);
1096     g_key_file_free(keyfile);
1097 }
1098
1099 static void config_parse(GAConfig *config, int argc, char **argv)
1100 {
1101     const char *sopt = "hVvdm:p:l:f:F::b:s:t:Dr";
1102     int opt_ind = 0, ch;
1103     const struct option lopt[] = {
1104         { "help", 0, NULL, 'h' },
1105         { "version", 0, NULL, 'V' },
1106         { "dump-conf", 0, NULL, 'D' },
1107         { "logfile", 1, NULL, 'l' },
1108         { "pidfile", 1, NULL, 'f' },
1109 #ifdef CONFIG_FSFREEZE
1110         { "fsfreeze-hook", 2, NULL, 'F' },
1111 #endif
1112         { "verbose", 0, NULL, 'v' },
1113         { "method", 1, NULL, 'm' },
1114         { "path", 1, NULL, 'p' },
1115         { "daemonize", 0, NULL, 'd' },
1116         { "block-rpcs", 1, NULL, 'b' },
1117         { "blacklist", 1, NULL, 'b' },  /* deprecated alias for 'block-rpcs' */
1118 #ifdef _WIN32
1119         { "service", 1, NULL, 's' },
1120 #endif
1121         { "statedir", 1, NULL, 't' },
1122         { "retry-path", 0, NULL, 'r' },
1123         { NULL, 0, NULL, 0 }
1124     };
1125
1126     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1127         switch (ch) {
1128         case 'm':
1129             g_free(config->method);
1130             config->method = g_strdup(optarg);
1131             break;
1132         case 'p':
1133             g_free(config->channel_path);
1134             config->channel_path = g_strdup(optarg);
1135             break;
1136         case 'l':
1137             g_free(config->log_filepath);
1138             config->log_filepath = g_strdup(optarg);
1139             break;
1140         case 'f':
1141             g_free(config->pid_filepath);
1142             config->pid_filepath = g_strdup(optarg);
1143             break;
1144 #ifdef CONFIG_FSFREEZE
1145         case 'F':
1146             g_free(config->fsfreeze_hook);
1147             config->fsfreeze_hook = optarg ? g_strdup(optarg) : get_relocated_path(QGA_FSFREEZE_HOOK_DEFAULT);
1148             break;
1149 #endif
1150         case 't':
1151             g_free(config->state_dir);
1152             config->state_dir = g_strdup(optarg);
1153             break;
1154         case 'v':
1155             /* enable all log levels */
1156             config->log_level = G_LOG_LEVEL_MASK;
1157             break;
1158         case 'V':
1159             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1160             exit(EXIT_SUCCESS);
1161         case 'd':
1162             config->daemonize = 1;
1163             break;
1164         case 'D':
1165             config->dumpconf = 1;
1166             break;
1167         case 'r':
1168             config->retry_path = true;
1169             break;
1170         case 'b': {
1171             if (is_help_option(optarg)) {
1172                 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1173                 exit(EXIT_SUCCESS);
1174             }
1175             config->blockedrpcs = g_list_concat(config->blockedrpcs,
1176                                                 split_list(optarg, ","));
1177             break;
1178         }
1179 #ifdef _WIN32
1180         case 's':
1181             config->service = optarg;
1182             if (strcmp(config->service, "install") == 0) {
1183                 if (ga_install_vss_provider()) {
1184                     exit(EXIT_FAILURE);
1185                 }
1186                 if (ga_install_service(config->channel_path,
1187                                        config->log_filepath, config->state_dir)) {
1188                     exit(EXIT_FAILURE);
1189                 }
1190                 exit(EXIT_SUCCESS);
1191             } else if (strcmp(config->service, "uninstall") == 0) {
1192                 ga_uninstall_vss_provider();
1193                 exit(ga_uninstall_service());
1194             } else if (strcmp(config->service, "vss-install") == 0) {
1195                 if (ga_install_vss_provider()) {
1196                     exit(EXIT_FAILURE);
1197                 }
1198                 exit(EXIT_SUCCESS);
1199             } else if (strcmp(config->service, "vss-uninstall") == 0) {
1200                 ga_uninstall_vss_provider();
1201                 exit(EXIT_SUCCESS);
1202             } else {
1203                 printf("Unknown service command.\n");
1204                 exit(EXIT_FAILURE);
1205             }
1206             break;
1207 #endif
1208         case 'h':
1209             usage(argv[0]);
1210             exit(EXIT_SUCCESS);
1211         case '?':
1212             g_print("Unknown option, try '%s --help' for more information.\n",
1213                     argv[0]);
1214             exit(EXIT_FAILURE);
1215         }
1216     }
1217 }
1218
1219 static void config_free(GAConfig *config)
1220 {
1221     g_free(config->method);
1222     g_free(config->log_filepath);
1223     g_free(config->pid_filepath);
1224     g_free(config->state_dir);
1225     g_free(config->channel_path);
1226     g_free(config->bliststr);
1227 #ifdef CONFIG_FSFREEZE
1228     g_free(config->fsfreeze_hook);
1229 #endif
1230     g_list_free_full(config->blockedrpcs, g_free);
1231     g_free(config);
1232 }
1233
1234 static bool check_is_frozen(GAState *s)
1235 {
1236 #ifndef _WIN32
1237     /* check if a previous instance of qemu-ga exited with filesystems' state
1238      * marked as frozen. this could be a stale value (a non-qemu-ga process
1239      * or reboot may have since unfrozen them), but better to require an
1240      * uneeded unfreeze than to risk hanging on start-up
1241      */
1242     struct stat st;
1243     if (stat(s->state_filepath_isfrozen, &st) == -1) {
1244         /* it's okay if the file doesn't exist, but if we can't access for
1245          * some other reason, such as permissions, there's a configuration
1246          * that needs to be addressed. so just bail now before we get into
1247          * more trouble later
1248          */
1249         if (errno != ENOENT) {
1250             g_critical("unable to access state file at path %s: %s",
1251                        s->state_filepath_isfrozen, strerror(errno));
1252             return EXIT_FAILURE;
1253         }
1254     } else {
1255         g_warning("previous instance appears to have exited with frozen"
1256                   " filesystems. deferring logging/pidfile creation and"
1257                   " disabling non-fsfreeze-safe commands until"
1258                   " guest-fsfreeze-thaw is issued, or filesystems are"
1259                   " manually unfrozen and the file %s is removed",
1260                   s->state_filepath_isfrozen);
1261         return true;
1262     }
1263 #endif
1264     return false;
1265 }
1266
1267 static GAState *initialize_agent(GAConfig *config, int socket_activation)
1268 {
1269     GAState *s = g_new0(GAState, 1);
1270
1271     g_assert(ga_state == NULL);
1272
1273     s->log_level = config->log_level;
1274     s->log_file = stderr;
1275 #ifdef CONFIG_FSFREEZE
1276     s->fsfreeze_hook = config->fsfreeze_hook;
1277 #endif
1278     s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1279     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1280                                                  config->state_dir);
1281     s->frozen = check_is_frozen(s);
1282
1283     g_log_set_default_handler(ga_log, s);
1284     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1285     ga_enable_logging(s);
1286
1287     g_debug("Guest agent version %s started", QEMU_FULL_VERSION);
1288
1289 #ifdef _WIN32
1290     /* On win32 the state directory is application specific (be it the default
1291      * or a user override). We got past the command line parsing; let's create
1292      * the directory (with any intermediate directories). If we run into an
1293      * error later on, we won't try to clean up the directory, it is considered
1294      * persistent.
1295      */
1296     if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1297         g_critical("unable to create (an ancestor of) the state directory"
1298                    " '%s': %s", config->state_dir, strerror(errno));
1299         return NULL;
1300     }
1301 #endif
1302
1303     if (ga_is_frozen(s)) {
1304         if (config->daemonize) {
1305             /* delay opening/locking of pidfile till filesystems are unfrozen */
1306             s->deferred_options.pid_filepath = config->pid_filepath;
1307             become_daemon(NULL);
1308         }
1309         if (config->log_filepath) {
1310             /* delay opening the log file till filesystems are unfrozen */
1311             s->deferred_options.log_filepath = config->log_filepath;
1312         }
1313         ga_disable_logging(s);
1314         qmp_for_each_command(&ga_commands, ga_disable_not_allowed, NULL);
1315     } else {
1316         if (config->daemonize) {
1317             become_daemon(config->pid_filepath);
1318         }
1319         if (config->log_filepath) {
1320             FILE *log_file = ga_open_logfile(config->log_filepath);
1321             if (!log_file) {
1322                 g_critical("unable to open specified log file: %s",
1323                            strerror(errno));
1324                 return NULL;
1325             }
1326             s->log_file = log_file;
1327         }
1328     }
1329
1330     /* load persistent state from disk */
1331     if (!read_persistent_state(&s->pstate,
1332                                s->pstate_filepath,
1333                                ga_is_frozen(s))) {
1334         g_critical("failed to load persistent state");
1335         return NULL;
1336     }
1337
1338     config->blockedrpcs = ga_command_init_blockedrpcs(config->blockedrpcs);
1339     if (config->blockedrpcs) {
1340         GList *l = config->blockedrpcs;
1341         s->blockedrpcs = config->blockedrpcs;
1342         do {
1343             g_debug("disabling command: %s", (char *)l->data);
1344             qmp_disable_command(&ga_commands, l->data, NULL);
1345             l = g_list_next(l);
1346         } while (l);
1347     }
1348     s->command_state = ga_command_state_new();
1349     ga_command_state_init(s, s->command_state);
1350     ga_command_state_init_all(s->command_state);
1351     json_message_parser_init(&s->parser, process_event, s, NULL);
1352
1353 #ifndef _WIN32
1354     if (!register_signal_handlers()) {
1355         g_critical("failed to register signal handlers");
1356         return NULL;
1357     }
1358 #endif
1359
1360     s->main_loop = g_main_loop_new(NULL, false);
1361
1362     s->config = config;
1363     s->socket_activation = socket_activation;
1364
1365 #ifdef _WIN32
1366     s->wakeup_event = CreateEvent(NULL, TRUE, FALSE, TEXT("WakeUp"));
1367     if (s->wakeup_event == NULL) {
1368         g_critical("CreateEvent failed");
1369         return NULL;
1370     }
1371 #endif
1372
1373     ga_state = s;
1374     return s;
1375 }
1376
1377 static void cleanup_agent(GAState *s)
1378 {
1379 #ifdef _WIN32
1380     CloseHandle(s->wakeup_event);
1381 #endif
1382     if (s->command_state) {
1383         ga_command_state_cleanup_all(s->command_state);
1384         ga_command_state_free(s->command_state);
1385         json_message_parser_destroy(&s->parser);
1386     }
1387     g_free(s->pstate_filepath);
1388     g_free(s->state_filepath_isfrozen);
1389     if (s->main_loop) {
1390         g_main_loop_unref(s->main_loop);
1391     }
1392     g_free(s);
1393     ga_state = NULL;
1394 }
1395
1396 static int run_agent_once(GAState *s)
1397 {
1398     if (!channel_init(s, s->config->method, s->config->channel_path,
1399                       s->socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
1400         g_critical("failed to initialize guest agent channel");
1401         return EXIT_FAILURE;
1402     }
1403
1404     g_main_loop_run(ga_state->main_loop);
1405
1406     if (s->channel) {
1407         ga_channel_free(s->channel);
1408     }
1409
1410     return EXIT_SUCCESS;
1411 }
1412
1413 static void wait_for_channel_availability(GAState *s)
1414 {
1415     g_warning("waiting for channel path...");
1416 #ifndef _WIN32
1417     sleep(QGA_RETRY_INTERVAL);
1418 #else
1419     DWORD dwWaitResult;
1420
1421     dwWaitResult = WaitForSingleObject(s->wakeup_event, INFINITE);
1422
1423     switch (dwWaitResult) {
1424     case WAIT_OBJECT_0:
1425         break;
1426     case WAIT_TIMEOUT:
1427         break;
1428     default:
1429         g_critical("WaitForSingleObject failed");
1430     }
1431 #endif
1432 }
1433
1434 static int run_agent(GAState *s)
1435 {
1436     int ret = EXIT_SUCCESS;
1437
1438     s->force_exit = false;
1439
1440     do {
1441         ret = run_agent_once(s);
1442         if (s->config->retry_path && !s->force_exit) {
1443             g_warning("agent stopped unexpectedly, restarting...");
1444             wait_for_channel_availability(s);
1445         }
1446     } while (s->config->retry_path && !s->force_exit);
1447
1448     return ret;
1449 }
1450
1451 static void stop_agent(GAState *s, bool requested)
1452 {
1453     if (!s->force_exit) {
1454         s->force_exit = requested;
1455     }
1456
1457     if (g_main_loop_is_running(s->main_loop)) {
1458         g_main_loop_quit(s->main_loop);
1459     }
1460 }
1461
1462 int main(int argc, char **argv)
1463 {
1464     int ret = EXIT_SUCCESS;
1465     GAState *s;
1466     GAConfig *config = g_new0(GAConfig, 1);
1467     int socket_activation;
1468
1469     config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1470
1471     qemu_init_exec_dir(argv[0]);
1472     qga_qmp_init_marshal(&ga_commands);
1473
1474     init_dfl_pathnames();
1475     config_load(config);
1476     config_parse(config, argc, argv);
1477
1478     if (config->pid_filepath == NULL) {
1479         config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1480     }
1481
1482     if (config->state_dir == NULL) {
1483         config->state_dir = g_strdup(dfl_pathnames.state_dir);
1484     }
1485
1486     if (config->method == NULL) {
1487         config->method = g_strdup("virtio-serial");
1488     }
1489
1490     socket_activation = check_socket_activation();
1491     if (socket_activation > 1) {
1492         g_critical("qemu-ga only supports listening on one socket");
1493         ret = EXIT_FAILURE;
1494         goto end;
1495     }
1496     if (socket_activation) {
1497         SocketAddress *addr;
1498
1499         g_free(config->method);
1500         g_free(config->channel_path);
1501         config->method = NULL;
1502         config->channel_path = NULL;
1503
1504         addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL);
1505         if (addr) {
1506             if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
1507                 config->method = g_strdup("unix-listen");
1508             } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
1509                 config->method = g_strdup("vsock-listen");
1510             }
1511
1512             qapi_free_SocketAddress(addr);
1513         }
1514
1515         if (!config->method) {
1516             g_critical("unsupported listen fd type");
1517             ret = EXIT_FAILURE;
1518             goto end;
1519         }
1520     } else if (config->channel_path == NULL) {
1521         if (strcmp(config->method, "virtio-serial") == 0) {
1522             /* try the default path for the virtio-serial port */
1523             config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1524         } else if (strcmp(config->method, "isa-serial") == 0) {
1525             /* try the default path for the serial port - COM1 */
1526             config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1527         } else {
1528             g_critical("must specify a path for this channel");
1529             ret = EXIT_FAILURE;
1530             goto end;
1531         }
1532     }
1533
1534     if (config->dumpconf) {
1535         config_dump(config);
1536         goto end;
1537     }
1538
1539     s = initialize_agent(config, socket_activation);
1540     if (!s) {
1541         g_critical("error initializing guest agent");
1542         goto end;
1543     }
1544
1545 #ifdef _WIN32
1546     if (config->daemonize) {
1547         SERVICE_TABLE_ENTRY service_table[] = {
1548             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1549         StartServiceCtrlDispatcher(service_table);
1550     } else {
1551         ret = run_agent(s);
1552     }
1553 #else
1554     ret = run_agent(s);
1555 #endif
1556
1557     cleanup_agent(s);
1558
1559 end:
1560     if (config->daemonize) {
1561         unlink(config->pid_filepath);
1562     }
1563
1564     config_free(config);
1565
1566     return ret;
1567 }