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