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 #include "commands-common.h"
  41
  42 #ifndef _WIN32
  43 #ifdef CONFIG_BSD
  44 #define QGA_VIRTIO_PATH_DEFAULT "/dev/vtcon/org.qemu.guest_agent.0"
  45 #else /* CONFIG_BSD */
  46 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
  47 #endif /* CONFIG_BSD */
  48 #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
  49 #define QGA_STATE_RELATIVE_DIR  "run"
  50 #else
  51 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
  52 #define QGA_STATE_RELATIVE_DIR  "qemu-ga"
  53 #define QGA_SERIAL_PATH_DEFAULT "COM1"
  54 #endif
  55 #ifdef CONFIG_FSFREEZE
  56 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
  57 #endif
  58 #define QGA_SENTINEL_BYTE 0xFF
  59 #define QGA_CONF_DEFAULT CONFIG_QEMU_CONFDIR G_DIR_SEPARATOR_S "qemu-ga.conf"
  60 #define QGA_RETRY_INTERVAL 5
  61
  62 static struct {
  63     const char *state_dir;
  64     const char *pidfile;
  65 } dfl_pathnames;
  66
  67 typedef struct GAPersistentState {
  68 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
  69     int64_t fd_counter;
  70 } GAPersistentState;
  71
  72 typedef struct GAConfig GAConfig;
  73
  74 struct GAState {
  75     JSONMessageParser parser;
  76     GMainLoop *main_loop;
  77     GAChannel *channel;
  78     bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
  79     GACommandState *command_state;
  80     GLogLevelFlags log_level;
  81     FILE *log_file;
  82     bool logging_enabled;
  83 #ifdef _WIN32
  84     GAService service;
  85     HANDLE wakeup_event;
  86     HANDLE event_log;
  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 int glib_log_level_to_system(int level)
 318 {
 319     switch (level) {
 320 #ifndef _WIN32
 321     case G_LOG_LEVEL_ERROR:
 322         return LOG_ERR;
 323     case G_LOG_LEVEL_CRITICAL:
 324         return LOG_CRIT;
 325     case G_LOG_LEVEL_WARNING:
 326         return LOG_WARNING;
 327     case G_LOG_LEVEL_MESSAGE:
 328         return LOG_NOTICE;
 329     case G_LOG_LEVEL_DEBUG:
 330         return LOG_DEBUG;
 331     case G_LOG_LEVEL_INFO:
 332     default:
 333         return LOG_INFO;
 334 #else
 335     case G_LOG_LEVEL_ERROR:
 336     case G_LOG_LEVEL_CRITICAL:
 337         return EVENTLOG_ERROR_TYPE;
 338     case G_LOG_LEVEL_WARNING:
 339         return EVENTLOG_WARNING_TYPE;
 340     case G_LOG_LEVEL_MESSAGE:
 341     case G_LOG_LEVEL_INFO:
 342     case G_LOG_LEVEL_DEBUG:
 343     default:
 344         return EVENTLOG_INFORMATION_TYPE;
 345 #endif
 346     }
 347 }
 348
 349 static void ga_log(const gchar *domain, GLogLevelFlags level,
 350                    const gchar *msg, gpointer opaque)
 351 {
 352     GAState *s = opaque;
 353     const char *level_str = ga_log_level_str(level);
 354
 355     if (!ga_logging_enabled(s)) {
 356         return;
 357     }
 358
 359     level &= G_LOG_LEVEL_MASK;
 360     if (g_strcmp0(domain, "syslog") == 0) {
 361 #ifndef _WIN32
 362         syslog(glib_log_level_to_system(level), "%s: %s", level_str, msg);
 363 #else
 364         ReportEvent(s->event_log, glib_log_level_to_system(level),
 365                     0, 1, NULL, 1, 0, &msg, NULL);
 366 #endif
 367     } else if (level & s->log_level) {
 368         g_autoptr(GDateTime) now = g_date_time_new_now_utc();
 369         g_autofree char *nowstr = g_date_time_format(now, "%s.%f");
 370         fprintf(s->log_file, "%s: %s: %s\n", nowstr, level_str, msg);
 371         fflush(s->log_file);
 372     }
 373 }
 374
 375 void ga_set_response_delimited(GAState *s)
 376 {
 377     s->delimit_response = true;
 378 }
 379
 380 static FILE *ga_open_logfile(const char *logfile)
 381 {
 382     FILE *f;
 383
 384     f = fopen(logfile, "a");
 385     if (!f) {
 386         return NULL;
 387     }
 388
 389     qemu_set_cloexec(fileno(f));
 390     return f;
 391 }
 392
 393 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
 394 {
 395     return strcmp(str1, str2);
 396 }
 397
 398 /* disable commands that aren't safe for fsfreeze */
 399 static void ga_disable_not_allowed(const QmpCommand *cmd, void *opaque)
 400 {
 401     bool allowed = false;
 402     int i = 0;
 403     const char *name = qmp_command_name(cmd);
 404
 405     while (ga_freeze_allowlist[i] != NULL) {
 406         if (strcmp(name, ga_freeze_allowlist[i]) == 0) {
 407             allowed = true;
 408         }
 409         i++;
 410     }
 411     if (!allowed) {
 412         g_debug("disabling command: %s", name);
 413         qmp_disable_command(&ga_commands, name, "the agent is in frozen state");
 414     }
 415 }
 416
 417 /* [re-]enable all commands, except those explicitly blocked by user */
 418 static void ga_enable_non_blocked(const QmpCommand *cmd, void *opaque)
 419 {
 420     GList *blockedrpcs = opaque;
 421     const char *name = qmp_command_name(cmd);
 422
 423     if (g_list_find_custom(blockedrpcs, name, ga_strcmp) == NULL &&
 424         !qmp_command_is_enabled(cmd)) {
 425         g_debug("enabling command: %s", name);
 426         qmp_enable_command(&ga_commands, name);
 427     }
 428 }
 429
 430 static bool ga_create_file(const char *path)
 431 {
 432     int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
 433     if (fd == -1) {
 434         g_warning("unable to open/create file %s: %s", path, strerror(errno));
 435         return false;
 436     }
 437     close(fd);
 438     return true;
 439 }
 440
 441 static bool ga_delete_file(const char *path)
 442 {
 443     int ret = unlink(path);
 444     if (ret == -1) {
 445         g_warning("unable to delete file: %s: %s", path, strerror(errno));
 446         return false;
 447     }
 448
 449     return true;
 450 }
 451
 452 bool ga_is_frozen(GAState *s)
 453 {
 454     return s->frozen;
 455 }
 456
 457 void ga_set_frozen(GAState *s)
 458 {
 459     if (ga_is_frozen(s)) {
 460         return;
 461     }
 462     /* disable all forbidden (for frozen state) commands */
 463     qmp_for_each_command(&ga_commands, ga_disable_not_allowed, NULL);
 464     g_warning("disabling logging due to filesystem freeze");
 465     ga_disable_logging(s);
 466     s->frozen = true;
 467     if (!ga_create_file(s->state_filepath_isfrozen)) {
 468         g_warning("unable to create %s, fsfreeze may not function properly",
 469                   s->state_filepath_isfrozen);
 470     }
 471 }
 472
 473 void ga_unset_frozen(GAState *s)
 474 {
 475     if (!ga_is_frozen(s)) {
 476         return;
 477     }
 478
 479     /* if we delayed creation/opening of pid/log files due to being
 480      * in a frozen state at start up, do it now
 481      */
 482     if (s->deferred_options.log_filepath) {
 483         s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
 484         if (!s->log_file) {
 485             s->log_file = stderr;
 486         }
 487         s->deferred_options.log_filepath = NULL;
 488     }
 489     ga_enable_logging(s);
 490     g_warning("logging re-enabled due to filesystem unfreeze");
 491     if (s->deferred_options.pid_filepath) {
 492         Error *err = NULL;
 493
 494         if (!qemu_write_pidfile(s->deferred_options.pid_filepath, &err)) {
 495             g_warning("%s", error_get_pretty(err));
 496             error_free(err);
 497         }
 498         s->deferred_options.pid_filepath = NULL;
 499     }
 500
 501     /* enable all disabled, non-blocked commands */
 502     qmp_for_each_command(&ga_commands, ga_enable_non_blocked, s->blockedrpcs);
 503     s->frozen = false;
 504     if (!ga_delete_file(s->state_filepath_isfrozen)) {
 505         g_warning("unable to delete %s, fsfreeze may not function properly",
 506                   s->state_filepath_isfrozen);
 507     }
 508 }
 509
 510 #ifdef CONFIG_FSFREEZE
 511 const char *ga_fsfreeze_hook(GAState *s)
 512 {
 513     return s->fsfreeze_hook;
 514 }
 515 #endif
 516
 517 static void become_daemon(const char *pidfile)
 518 {
 519 #ifndef _WIN32
 520     pid_t pid, sid;
 521
 522     pid = fork();
 523     if (pid < 0) {
 524         exit(EXIT_FAILURE);
 525     }
 526     if (pid > 0) {
 527         exit(EXIT_SUCCESS);
 528     }
 529
 530     if (pidfile) {
 531         Error *err = NULL;
 532
 533         if (!qemu_write_pidfile(pidfile, &err)) {
 534             g_critical("%s", error_get_pretty(err));
 535             error_free(err);
 536             exit(EXIT_FAILURE);
 537         }
 538     }
 539
 540     umask(S_IRWXG | S_IRWXO);
 541     sid = setsid();
 542     if (sid < 0) {
 543         goto fail;
 544     }
 545     if ((chdir("/")) < 0) {
 546         goto fail;
 547     }
 548
 549     reopen_fd_to_null(STDIN_FILENO);
 550     reopen_fd_to_null(STDOUT_FILENO);
 551     reopen_fd_to_null(STDERR_FILENO);
 552     return;
 553
 554 fail:
 555     if (pidfile) {
 556         unlink(pidfile);
 557     }
 558     g_critical("failed to daemonize");
 559     exit(EXIT_FAILURE);
 560 #endif
 561 }
 562
 563 static int send_response(GAState *s, const QDict *rsp)
 564 {
 565     GString *response;
 566     GIOStatus status;
 567
 568     g_assert(s->channel);
 569
 570     if (!rsp) {
 571         return 0;
 572     }
 573
 574     response = qobject_to_json(QOBJECT(rsp));
 575     if (!response) {
 576         return -EINVAL;
 577     }
 578
 579     if (s->delimit_response) {
 580         s->delimit_response = false;
 581         g_string_prepend_c(response, QGA_SENTINEL_BYTE);
 582     }
 583
 584     g_string_append_c(response, '\n');
 585     status = ga_channel_write_all(s->channel, response->str, response->len);
 586     g_string_free(response, true);
 587     if (status != G_IO_STATUS_NORMAL) {
 588         return -EIO;
 589     }
 590
 591     return 0;
 592 }
 593
 594 /* handle requests/control events coming in over the channel */
 595 static void process_event(void *opaque, QObject *obj, Error *err)
 596 {
 597     GAState *s = opaque;
 598     QDict *rsp;
 599     int ret;
 600
 601     g_debug("process_event: called");
 602     assert(!obj != !err);
 603     if (err) {
 604         rsp = qmp_error_response(err);
 605         goto end;
 606     }
 607
 608     g_debug("processing command");
 609     rsp = qmp_dispatch(&ga_commands, obj, false, NULL);
 610
 611 end:
 612     ret = send_response(s, rsp);
 613     if (ret < 0) {
 614         g_warning("error sending error response: %s", strerror(-ret));
 615     }
 616     qobject_unref(rsp);
 617     qobject_unref(obj);
 618 }
 619
 620 /* false return signals GAChannel to close the current client connection */
 621 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 622 {
 623     GAState *s = data;
 624     gchar buf[QGA_READ_COUNT_DEFAULT + 1];
 625     gsize count;
 626     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 627     switch (status) {
 628     case G_IO_STATUS_ERROR:
 629         g_warning("error reading channel");
 630         stop_agent(s, false);
 631         return false;
 632     case G_IO_STATUS_NORMAL:
 633         buf[count] = 0;
 634         g_debug("read data, count: %d, data: %s", (int)count, buf);
 635         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 636         break;
 637     case G_IO_STATUS_EOF:
 638         g_debug("received EOF");
 639         if (!s->virtio) {
 640             return false;
 641         }
 642         /* fall through */
 643     case G_IO_STATUS_AGAIN:
 644         /* virtio causes us to spin here when no process is attached to
 645          * host-side chardev. sleep a bit to mitigate this
 646          */
 647         if (s->virtio) {
 648             g_usleep(G_USEC_PER_SEC / 10);
 649         }
 650         return true;
 651     default:
 652         g_warning("unknown channel read status, closing");
 653         return false;
 654     }
 655     return true;
 656 }
 657
 658 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path,
 659                              int listen_fd)
 660 {
 661     GAChannelMethod channel_method;
 662
 663     if (strcmp(method, "virtio-serial") == 0) {
 664         s->virtio = true; /* virtio requires special handling in some cases */
 665         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 666     } else if (strcmp(method, "isa-serial") == 0) {
 667         channel_method = GA_CHANNEL_ISA_SERIAL;
 668     } else if (strcmp(method, "unix-listen") == 0) {
 669         channel_method = GA_CHANNEL_UNIX_LISTEN;
 670     } else if (strcmp(method, "vsock-listen") == 0) {
 671         channel_method = GA_CHANNEL_VSOCK_LISTEN;
 672     } else {
 673         g_critical("unsupported channel method/type: %s", method);
 674         return false;
 675     }
 676
 677     s->channel = ga_channel_new(channel_method, path, listen_fd,
 678                                 channel_event_cb, s);
 679     if (!s->channel) {
 680         g_critical("failed to create guest agent channel");
 681         return false;
 682     }
 683
 684     return true;
 685 }
 686
 687 #ifdef _WIN32
 688 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data)
 689 {
 690     DWORD ret = NO_ERROR;
 691     PDEV_BROADCAST_HDR broadcast_header = (PDEV_BROADCAST_HDR)data;
 692
 693     if (broadcast_header->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE) {
 694         switch (type) {
 695             /* Device inserted */
 696         case DBT_DEVICEARRIVAL:
 697             /* Start QEMU-ga's service */
 698             if (!SetEvent(ga_state->wakeup_event)) {
 699                 ret = GetLastError();
 700             }
 701             break;
 702             /* Device removed */
 703         case DBT_DEVICEQUERYREMOVE:
 704         case DBT_DEVICEREMOVEPENDING:
 705         case DBT_DEVICEREMOVECOMPLETE:
 706             /* Stop QEMU-ga's service */
 707             if (!ResetEvent(ga_state->wakeup_event)) {
 708                 ret = GetLastError();
 709             }
 710             break;
 711         default:
 712             ret = ERROR_CALL_NOT_IMPLEMENTED;
 713         }
 714     }
 715     return ret;
 716 }
 717
 718 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 719                                   LPVOID ctx)
 720 {
 721     DWORD ret = NO_ERROR;
 722     GAService *service = &ga_state->service;
 723
 724     switch (ctrl) {
 725     case SERVICE_CONTROL_STOP:
 726     case SERVICE_CONTROL_SHUTDOWN:
 727         quit_handler(SIGTERM);
 728         SetEvent(ga_state->wakeup_event);
 729         service->status.dwCurrentState = SERVICE_STOP_PENDING;
 730         SetServiceStatus(service->status_handle, &service->status);
 731         break;
 732     case SERVICE_CONTROL_DEVICEEVENT:
 733         handle_serial_device_events(type, data);
 734         break;
 735
 736     default:
 737         ret = ERROR_CALL_NOT_IMPLEMENTED;
 738     }
 739     return ret;
 740 }
 741
 742 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 743 {
 744     GAService *service = &ga_state->service;
 745
 746     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 747         service_ctrl_handler, NULL);
 748
 749     if (service->status_handle == 0) {
 750         g_critical("Failed to register extended requests function!\n");
 751         return;
 752     }
 753
 754     service->status.dwServiceType = SERVICE_WIN32;
 755     service->status.dwCurrentState = SERVICE_RUNNING;
 756     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 757     service->status.dwWin32ExitCode = NO_ERROR;
 758     service->status.dwServiceSpecificExitCode = NO_ERROR;
 759     service->status.dwCheckPoint = 0;
 760     service->status.dwWaitHint = 0;
 761     DEV_BROADCAST_DEVICEINTERFACE notification_filter;
 762     ZeroMemory(&notification_filter, sizeof(notification_filter));
 763     notification_filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
 764     notification_filter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
 765     notification_filter.dbcc_classguid = GUID_VIOSERIAL_PORT;
 766
 767     service->device_notification_handle =
 768         RegisterDeviceNotification(service->status_handle,
 769             &notification_filter, DEVICE_NOTIFY_SERVICE_HANDLE);
 770     if (!service->device_notification_handle) {
 771         g_critical("Failed to register device notification handle!\n");
 772         return;
 773     }
 774     SetServiceStatus(service->status_handle, &service->status);
 775
 776     run_agent(ga_state);
 777
 778     UnregisterDeviceNotification(service->device_notification_handle);
 779     service->status.dwCurrentState = SERVICE_STOPPED;
 780     SetServiceStatus(service->status_handle, &service->status);
 781 }
 782 #endif
 783
 784 static void set_persistent_state_defaults(GAPersistentState *pstate)
 785 {
 786     g_assert(pstate);
 787     pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
 788 }
 789
 790 static void persistent_state_from_keyfile(GAPersistentState *pstate,
 791                                           GKeyFile *keyfile)
 792 {
 793     g_assert(pstate);
 794     g_assert(keyfile);
 795     /* if any fields are missing, either because the file was tampered with
 796      * by agents of chaos, or because the field wasn't present at the time the
 797      * file was created, the best we can ever do is start over with the default
 798      * values. so load them now, and ignore any errors in accessing key-value
 799      * pairs
 800      */
 801     set_persistent_state_defaults(pstate);
 802
 803     if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
 804         pstate->fd_counter =
 805             g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
 806     }
 807 }
 808
 809 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
 810                                         GKeyFile *keyfile)
 811 {
 812     g_assert(pstate);
 813     g_assert(keyfile);
 814
 815     g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
 816 }
 817
 818 static gboolean write_persistent_state(const GAPersistentState *pstate,
 819                                        const gchar *path)
 820 {
 821     GKeyFile *keyfile = g_key_file_new();
 822     GError *gerr = NULL;
 823     gboolean ret = true;
 824     gchar *data = NULL;
 825     gsize data_len;
 826
 827     g_assert(pstate);
 828
 829     persistent_state_to_keyfile(pstate, keyfile);
 830     data = g_key_file_to_data(keyfile, &data_len, &gerr);
 831     if (gerr) {
 832         g_critical("failed to convert persistent state to string: %s",
 833                    gerr->message);
 834         ret = false;
 835         goto out;
 836     }
 837
 838     g_file_set_contents(path, data, data_len, &gerr);
 839     if (gerr) {
 840         g_critical("failed to write persistent state to %s: %s",
 841                     path, gerr->message);
 842         ret = false;
 843         goto out;
 844     }
 845
 846 out:
 847     if (gerr) {
 848         g_error_free(gerr);
 849     }
 850     if (keyfile) {
 851         g_key_file_free(keyfile);
 852     }
 853     g_free(data);
 854     return ret;
 855 }
 856
 857 static gboolean read_persistent_state(GAPersistentState *pstate,
 858                                       const gchar *path, gboolean frozen)
 859 {
 860     GKeyFile *keyfile = NULL;
 861     GError *gerr = NULL;
 862     struct stat st;
 863     gboolean ret = true;
 864
 865     g_assert(pstate);
 866
 867     if (stat(path, &st) == -1) {
 868         /* it's okay if state file doesn't exist, but any other error
 869          * indicates a permissions issue or some other misconfiguration
 870          * that we likely won't be able to recover from.
 871          */
 872         if (errno != ENOENT) {
 873             g_critical("unable to access state file at path %s: %s",
 874                        path, strerror(errno));
 875             ret = false;
 876             goto out;
 877         }
 878
 879         /* file doesn't exist. initialize state to default values and
 880          * attempt to save now. (we could wait till later when we have
 881          * modified state we need to commit, but if there's a problem,
 882          * such as a missing parent directory, we want to catch it now)
 883          *
 884          * there is a potential scenario where someone either managed to
 885          * update the agent from a version that didn't use a key store
 886          * while qemu-ga thought the filesystem was frozen, or
 887          * deleted the key store prior to issuing a fsfreeze, prior
 888          * to restarting the agent. in this case we go ahead and defer
 889          * initial creation till we actually have modified state to
 890          * write, otherwise fail to recover from freeze.
 891          */
 892         set_persistent_state_defaults(pstate);
 893         if (!frozen) {
 894             ret = write_persistent_state(pstate, path);
 895             if (!ret) {
 896                 g_critical("unable to create state file at path %s", path);
 897                 ret = false;
 898                 goto out;
 899             }
 900         }
 901         ret = true;
 902         goto out;
 903     }
 904
 905     keyfile = g_key_file_new();
 906     g_key_file_load_from_file(keyfile, path, 0, &gerr);
 907     if (gerr) {
 908         g_critical("error loading persistent state from path: %s, %s",
 909                    path, gerr->message);
 910         ret = false;
 911         goto out;
 912     }
 913
 914     persistent_state_from_keyfile(pstate, keyfile);
 915
 916 out:
 917     if (keyfile) {
 918         g_key_file_free(keyfile);
 919     }
 920     if (gerr) {
 921         g_error_free(gerr);
 922     }
 923
 924     return ret;
 925 }
 926
 927 int64_t ga_get_fd_handle(GAState *s, Error **errp)
 928 {
 929     int64_t handle;
 930
 931     g_assert(s->pstate_filepath);
 932     /*
 933      * We block commands and avoid operations that potentially require
 934      * writing to disk when we're in a frozen state. this includes opening
 935      * new files, so we should never get here in that situation
 936      */
 937     g_assert(!ga_is_frozen(s));
 938
 939     handle = s->pstate.fd_counter++;
 940
 941     /* This should never happen on a reasonable timeframe, as guest-file-open
 942      * would have to be issued 2^63 times */
 943     if (s->pstate.fd_counter == INT64_MAX) {
 944         abort();
 945     }
 946
 947     if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
 948         error_setg(errp, "failed to commit persistent state to disk");
 949         return -1;
 950     }
 951
 952     return handle;
 953 }
 954
 955 static void ga_print_cmd(const QmpCommand *cmd, void *opaque)
 956 {
 957     printf("%s\n", qmp_command_name(cmd));
 958 }
 959
 960 static GList *split_list(const gchar *str, const gchar *delim)
 961 {
 962     GList *list = NULL;
 963     int i;
 964     gchar **strv;
 965
 966     strv = g_strsplit(str, delim, -1);
 967     for (i = 0; strv[i]; i++) {
 968         list = g_list_prepend(list, strv[i]);
 969     }
 970     g_free(strv);
 971
 972     return list;
 973 }
 974
 975 struct GAConfig {
 976     char *channel_path;
 977     char *method;
 978     char *log_filepath;
 979     char *pid_filepath;
 980 #ifdef CONFIG_FSFREEZE
 981     char *fsfreeze_hook;
 982 #endif
 983     char *state_dir;
 984 #ifdef _WIN32
 985     const char *service;
 986 #endif
 987     gchar *bliststr; /* blockedrpcs may point to this string */
 988     GList *blockedrpcs;
 989     int daemonize;
 990     GLogLevelFlags log_level;
 991     int dumpconf;
 992     bool retry_path;
 993 };
 994
 995 static void config_load(GAConfig *config)
 996 {
 997     GError *gerr = NULL;
 998     GKeyFile *keyfile;
 999     g_autofree char *conf = g_strdup(g_getenv("QGA_CONF")) ?: get_relocated_path(QGA_CONF_DEFAULT);
1000     const gchar *blockrpcs_key = "block-rpcs";
1001
1002     /* read system config */
1003     keyfile = g_key_file_new();
1004     if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
1005         goto end;
1006     }
1007     if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
1008         config->daemonize =
1009             g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
1010     }
1011     if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
1012         config->method =
1013             g_key_file_get_string(keyfile, "general", "method", &gerr);
1014     }
1015     if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
1016         config->channel_path =
1017             g_key_file_get_string(keyfile, "general", "path", &gerr);
1018     }
1019     if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
1020         config->log_filepath =
1021             g_key_file_get_string(keyfile, "general", "logfile", &gerr);
1022     }
1023     if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
1024         config->pid_filepath =
1025             g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
1026     }
1027 #ifdef CONFIG_FSFREEZE
1028     if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
1029         config->fsfreeze_hook =
1030             g_key_file_get_string(keyfile,
1031                                   "general", "fsfreeze-hook", &gerr);
1032     }
1033 #endif
1034     if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
1035         config->state_dir =
1036             g_key_file_get_string(keyfile, "general", "statedir", &gerr);
1037     }
1038     if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
1039         g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
1040         /* enable all log levels */
1041         config->log_level = G_LOG_LEVEL_MASK;
1042     }
1043     if (g_key_file_has_key(keyfile, "general", "retry-path", NULL)) {
1044         config->retry_path =
1045             g_key_file_get_boolean(keyfile, "general", "retry-path", &gerr);
1046     }
1047
1048     if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
1049         g_warning("config using deprecated 'blacklist' key, should be replaced"
1050                   " with the 'block-rpcs' key.");
1051         blockrpcs_key = "blacklist";
1052     }
1053     if (g_key_file_has_key(keyfile, "general", blockrpcs_key, NULL)) {
1054         config->bliststr =
1055             g_key_file_get_string(keyfile, "general", blockrpcs_key, &gerr);
1056         config->blockedrpcs = g_list_concat(config->blockedrpcs,
1057                                           split_list(config->bliststr, ","));
1058     }
1059
1060 end:
1061     g_key_file_free(keyfile);
1062     if (gerr &&
1063         !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
1064         g_critical("error loading configuration from path: %s, %s",
1065                    conf, gerr->message);
1066         exit(EXIT_FAILURE);
1067     }
1068     g_clear_error(&gerr);
1069 }
1070
1071 static gchar *list_join(GList *list, const gchar separator)
1072 {
1073     GString *str = g_string_new("");
1074
1075     while (list) {
1076         str = g_string_append(str, (gchar *)list->data);
1077         list = g_list_next(list);
1078         if (list) {
1079             str = g_string_append_c(str, separator);
1080         }
1081     }
1082
1083     return g_string_free(str, FALSE);
1084 }
1085
1086 static void config_dump(GAConfig *config)
1087 {
1088     GError *error = NULL;
1089     GKeyFile *keyfile;
1090     gchar *tmp;
1091
1092     keyfile = g_key_file_new();
1093     g_assert(keyfile);
1094
1095     g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1096     g_key_file_set_string(keyfile, "general", "method", config->method);
1097     if (config->channel_path) {
1098         g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1099     }
1100     if (config->log_filepath) {
1101         g_key_file_set_string(keyfile, "general", "logfile",
1102                               config->log_filepath);
1103     }
1104     g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1105 #ifdef CONFIG_FSFREEZE
1106     if (config->fsfreeze_hook) {
1107         g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1108                               config->fsfreeze_hook);
1109     }
1110 #endif
1111     g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1112     g_key_file_set_boolean(keyfile, "general", "verbose",
1113                            config->log_level == G_LOG_LEVEL_MASK);
1114     g_key_file_set_boolean(keyfile, "general", "retry-path",
1115                            config->retry_path);
1116     tmp = list_join(config->blockedrpcs, ',');
1117     g_key_file_set_string(keyfile, "general", "block-rpcs", tmp);
1118     g_free(tmp);
1119
1120     tmp = g_key_file_to_data(keyfile, NULL, &error);
1121     if (error) {
1122         g_critical("Failed to dump keyfile: %s", error->message);
1123         g_clear_error(&error);
1124     } else {
1125         printf("%s", tmp);
1126     }
1127
1128     g_free(tmp);
1129     g_key_file_free(keyfile);
1130 }
1131
1132 static void config_parse(GAConfig *config, int argc, char **argv)
1133 {
1134     const char *sopt = "hVvdm:p:l:f:F::b:s:t:Dr";
1135     int opt_ind = 0, ch;
1136     const struct option lopt[] = {
1137         { "help", 0, NULL, 'h' },
1138         { "version", 0, NULL, 'V' },
1139         { "dump-conf", 0, NULL, 'D' },
1140         { "logfile", 1, NULL, 'l' },
1141         { "pidfile", 1, NULL, 'f' },
1142 #ifdef CONFIG_FSFREEZE
1143         { "fsfreeze-hook", 2, NULL, 'F' },
1144 #endif
1145         { "verbose", 0, NULL, 'v' },
1146         { "method", 1, NULL, 'm' },
1147         { "path", 1, NULL, 'p' },
1148         { "daemonize", 0, NULL, 'd' },
1149         { "block-rpcs", 1, NULL, 'b' },
1150         { "blacklist", 1, NULL, 'b' },  /* deprecated alias for 'block-rpcs' */
1151 #ifdef _WIN32
1152         { "service", 1, NULL, 's' },
1153 #endif
1154         { "statedir", 1, NULL, 't' },
1155         { "retry-path", 0, NULL, 'r' },
1156         { NULL, 0, NULL, 0 }
1157     };
1158
1159     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1160         switch (ch) {
1161         case 'm':
1162             g_free(config->method);
1163             config->method = g_strdup(optarg);
1164             break;
1165         case 'p':
1166             g_free(config->channel_path);
1167             config->channel_path = g_strdup(optarg);
1168             break;
1169         case 'l':
1170             g_free(config->log_filepath);
1171             config->log_filepath = g_strdup(optarg);
1172             break;
1173         case 'f':
1174             g_free(config->pid_filepath);
1175             config->pid_filepath = g_strdup(optarg);
1176             break;
1177 #ifdef CONFIG_FSFREEZE
1178         case 'F':
1179             g_free(config->fsfreeze_hook);
1180             config->fsfreeze_hook = optarg ? g_strdup(optarg) : get_relocated_path(QGA_FSFREEZE_HOOK_DEFAULT);
1181             break;
1182 #endif
1183         case 't':
1184             g_free(config->state_dir);
1185             config->state_dir = g_strdup(optarg);
1186             break;
1187         case 'v':
1188             /* enable all log levels */
1189             config->log_level = G_LOG_LEVEL_MASK;
1190             break;
1191         case 'V':
1192             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1193             exit(EXIT_SUCCESS);
1194         case 'd':
1195             config->daemonize = 1;
1196             break;
1197         case 'D':
1198             config->dumpconf = 1;
1199             break;
1200         case 'r':
1201             config->retry_path = true;
1202             break;
1203         case 'b': {
1204             if (is_help_option(optarg)) {
1205                 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1206                 exit(EXIT_SUCCESS);
1207             }
1208             config->blockedrpcs = g_list_concat(config->blockedrpcs,
1209                                                 split_list(optarg, ","));
1210             break;
1211         }
1212 #ifdef _WIN32
1213         case 's':
1214             config->service = optarg;
1215             if (strcmp(config->service, "install") == 0) {
1216                 if (ga_install_vss_provider()) {
1217                     exit(EXIT_FAILURE);
1218                 }
1219                 if (ga_install_service(config->channel_path,
1220                                        config->log_filepath, config->state_dir)) {
1221                     exit(EXIT_FAILURE);
1222                 }
1223                 exit(EXIT_SUCCESS);
1224             } else if (strcmp(config->service, "uninstall") == 0) {
1225                 ga_uninstall_vss_provider();
1226                 exit(ga_uninstall_service());
1227             } else if (strcmp(config->service, "vss-install") == 0) {
1228                 if (ga_install_vss_provider()) {
1229                     exit(EXIT_FAILURE);
1230                 }
1231                 exit(EXIT_SUCCESS);
1232             } else if (strcmp(config->service, "vss-uninstall") == 0) {
1233                 ga_uninstall_vss_provider();
1234                 exit(EXIT_SUCCESS);
1235             } else {
1236                 printf("Unknown service command.\n");
1237                 exit(EXIT_FAILURE);
1238             }
1239             break;
1240 #endif
1241         case 'h':
1242             usage(argv[0]);
1243             exit(EXIT_SUCCESS);
1244         case '?':
1245             g_print("Unknown option, try '%s --help' for more information.\n",
1246                     argv[0]);
1247             exit(EXIT_FAILURE);
1248         }
1249     }
1250 }
1251
1252 static void config_free(GAConfig *config)
1253 {
1254     g_free(config->method);
1255     g_free(config->log_filepath);
1256     g_free(config->pid_filepath);
1257     g_free(config->state_dir);
1258     g_free(config->channel_path);
1259     g_free(config->bliststr);
1260 #ifdef CONFIG_FSFREEZE
1261     g_free(config->fsfreeze_hook);
1262 #endif
1263     g_list_free_full(config->blockedrpcs, g_free);
1264     g_free(config);
1265 }
1266
1267 static bool check_is_frozen(GAState *s)
1268 {
1269 #ifndef _WIN32
1270     /* check if a previous instance of qemu-ga exited with filesystems' state
1271      * marked as frozen. this could be a stale value (a non-qemu-ga process
1272      * or reboot may have since unfrozen them), but better to require an
1273      * uneeded unfreeze than to risk hanging on start-up
1274      */
1275     struct stat st;
1276     if (stat(s->state_filepath_isfrozen, &st) == -1) {
1277         /* it's okay if the file doesn't exist, but if we can't access for
1278          * some other reason, such as permissions, there's a configuration
1279          * that needs to be addressed. so just bail now before we get into
1280          * more trouble later
1281          */
1282         if (errno != ENOENT) {
1283             g_critical("unable to access state file at path %s: %s",
1284                        s->state_filepath_isfrozen, strerror(errno));
1285             return EXIT_FAILURE;
1286         }
1287     } else {
1288         g_warning("previous instance appears to have exited with frozen"
1289                   " filesystems. deferring logging/pidfile creation and"
1290                   " disabling non-fsfreeze-safe commands until"
1291                   " guest-fsfreeze-thaw is issued, or filesystems are"
1292                   " manually unfrozen and the file %s is removed",
1293                   s->state_filepath_isfrozen);
1294         return true;
1295     }
1296 #endif
1297     return false;
1298 }
1299
1300 static GAState *initialize_agent(GAConfig *config, int socket_activation)
1301 {
1302     GAState *s = g_new0(GAState, 1);
1303
1304     g_assert(ga_state == NULL);
1305
1306     s->log_level = config->log_level;
1307     s->log_file = stderr;
1308 #ifdef CONFIG_FSFREEZE
1309     s->fsfreeze_hook = config->fsfreeze_hook;
1310 #endif
1311     s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1312     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1313                                                  config->state_dir);
1314     s->frozen = check_is_frozen(s);
1315
1316     g_log_set_default_handler(ga_log, s);
1317     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1318     ga_enable_logging(s);
1319
1320     g_debug("Guest agent version %s started", QEMU_FULL_VERSION);
1321
1322 #ifdef _WIN32
1323     s->event_log = RegisterEventSource(NULL, "qemu-ga");
1324     if (!s->event_log) {
1325         g_autofree gchar *errmsg = g_win32_error_message(GetLastError());
1326         g_critical("unable to register event source: %s", errmsg);
1327         return NULL;
1328     }
1329
1330     /* On win32 the state directory is application specific (be it the default
1331      * or a user override). We got past the command line parsing; let's create
1332      * the directory (with any intermediate directories). If we run into an
1333      * error later on, we won't try to clean up the directory, it is considered
1334      * persistent.
1335      */
1336     if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1337         g_critical("unable to create (an ancestor of) the state directory"
1338                    " '%s': %s", config->state_dir, strerror(errno));
1339         return NULL;
1340     }
1341 #endif
1342
1343     if (ga_is_frozen(s)) {
1344         if (config->daemonize) {
1345             /* delay opening/locking of pidfile till filesystems are unfrozen */
1346             s->deferred_options.pid_filepath = config->pid_filepath;
1347             become_daemon(NULL);
1348         }
1349         if (config->log_filepath) {
1350             /* delay opening the log file till filesystems are unfrozen */
1351             s->deferred_options.log_filepath = config->log_filepath;
1352         }
1353         ga_disable_logging(s);
1354         qmp_for_each_command(&ga_commands, ga_disable_not_allowed, NULL);
1355     } else {
1356         if (config->daemonize) {
1357             become_daemon(config->pid_filepath);
1358         }
1359         if (config->log_filepath) {
1360             FILE *log_file = ga_open_logfile(config->log_filepath);
1361             if (!log_file) {
1362                 g_critical("unable to open specified log file: %s",
1363                            strerror(errno));
1364                 return NULL;
1365             }
1366             s->log_file = log_file;
1367         }
1368     }
1369
1370     /* load persistent state from disk */
1371     if (!read_persistent_state(&s->pstate,
1372                                s->pstate_filepath,
1373                                ga_is_frozen(s))) {
1374         g_critical("failed to load persistent state");
1375         return NULL;
1376     }
1377
1378     config->blockedrpcs = ga_command_init_blockedrpcs(config->blockedrpcs);
1379     if (config->blockedrpcs) {
1380         GList *l = config->blockedrpcs;
1381         s->blockedrpcs = config->blockedrpcs;
1382         do {
1383             g_debug("disabling command: %s", (char *)l->data);
1384             qmp_disable_command(&ga_commands, l->data, NULL);
1385             l = g_list_next(l);
1386         } while (l);
1387     }
1388     s->command_state = ga_command_state_new();
1389     ga_command_state_init(s, s->command_state);
1390     ga_command_state_init_all(s->command_state);
1391     json_message_parser_init(&s->parser, process_event, s, NULL);
1392
1393 #ifndef _WIN32
1394     if (!register_signal_handlers()) {
1395         g_critical("failed to register signal handlers");
1396         return NULL;
1397     }
1398 #endif
1399
1400     s->main_loop = g_main_loop_new(NULL, false);
1401
1402     s->config = config;
1403     s->socket_activation = socket_activation;
1404
1405 #ifdef _WIN32
1406     s->wakeup_event = CreateEvent(NULL, TRUE, FALSE, TEXT("WakeUp"));
1407     if (s->wakeup_event == NULL) {
1408         g_critical("CreateEvent failed");
1409         return NULL;
1410     }
1411 #endif
1412
1413     ga_state = s;
1414     return s;
1415 }
1416
1417 static void cleanup_agent(GAState *s)
1418 {
1419 #ifdef _WIN32
1420     CloseHandle(s->wakeup_event);
1421     CloseHandle(s->event_log);
1422 #endif
1423     if (s->command_state) {
1424         ga_command_state_cleanup_all(s->command_state);
1425         ga_command_state_free(s->command_state);
1426         json_message_parser_destroy(&s->parser);
1427     }
1428     g_free(s->pstate_filepath);
1429     g_free(s->state_filepath_isfrozen);
1430     if (s->main_loop) {
1431         g_main_loop_unref(s->main_loop);
1432     }
1433     g_free(s);
1434     ga_state = NULL;
1435 }
1436
1437 static int run_agent_once(GAState *s)
1438 {
1439     if (!channel_init(s, s->config->method, s->config->channel_path,
1440                       s->socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
1441         g_critical("failed to initialize guest agent channel");
1442         return EXIT_FAILURE;
1443     }
1444
1445     g_main_loop_run(ga_state->main_loop);
1446
1447     if (s->channel) {
1448         ga_channel_free(s->channel);
1449     }
1450
1451     return EXIT_SUCCESS;
1452 }
1453
1454 static void wait_for_channel_availability(GAState *s)
1455 {
1456     g_warning("waiting for channel path...");
1457 #ifndef _WIN32
1458     sleep(QGA_RETRY_INTERVAL);
1459 #else
1460     DWORD dwWaitResult;
1461
1462     dwWaitResult = WaitForSingleObject(s->wakeup_event, INFINITE);
1463
1464     switch (dwWaitResult) {
1465     case WAIT_OBJECT_0:
1466         break;
1467     case WAIT_TIMEOUT:
1468         break;
1469     default:
1470         g_critical("WaitForSingleObject failed");
1471     }
1472 #endif
1473 }
1474
1475 static int run_agent(GAState *s)
1476 {
1477     int ret = EXIT_SUCCESS;
1478
1479     s->force_exit = false;
1480
1481     do {
1482         ret = run_agent_once(s);
1483         if (s->config->retry_path && !s->force_exit) {
1484             g_warning("agent stopped unexpectedly, restarting...");
1485             wait_for_channel_availability(s);
1486         }
1487     } while (s->config->retry_path && !s->force_exit);
1488
1489     return ret;
1490 }
1491
1492 static void stop_agent(GAState *s, bool requested)
1493 {
1494     if (!s->force_exit) {
1495         s->force_exit = requested;
1496     }
1497
1498     if (g_main_loop_is_running(s->main_loop)) {
1499         g_main_loop_quit(s->main_loop);
1500     }
1501 }
1502
1503 int main(int argc, char **argv)
1504 {
1505     int ret = EXIT_SUCCESS;
1506     GAState *s;
1507     GAConfig *config = g_new0(GAConfig, 1);
1508     int socket_activation;
1509
1510     config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1511
1512     qemu_init_exec_dir(argv[0]);
1513     qga_qmp_init_marshal(&ga_commands);
1514
1515     init_dfl_pathnames();
1516     config_load(config);
1517     config_parse(config, argc, argv);
1518
1519     if (config->pid_filepath == NULL) {
1520         config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1521     }
1522
1523     if (config->state_dir == NULL) {
1524         config->state_dir = g_strdup(dfl_pathnames.state_dir);
1525     }
1526
1527     if (config->method == NULL) {
1528         config->method = g_strdup("virtio-serial");
1529     }
1530
1531     socket_activation = check_socket_activation();
1532     if (socket_activation > 1) {
1533         g_critical("qemu-ga only supports listening on one socket");
1534         ret = EXIT_FAILURE;
1535         goto end;
1536     }
1537     if (socket_activation) {
1538         SocketAddress *addr;
1539
1540         g_free(config->method);
1541         g_free(config->channel_path);
1542         config->method = NULL;
1543         config->channel_path = NULL;
1544
1545         addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL);
1546         if (addr) {
1547             if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
1548                 config->method = g_strdup("unix-listen");
1549             } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
1550                 config->method = g_strdup("vsock-listen");
1551             }
1552
1553             qapi_free_SocketAddress(addr);
1554         }
1555
1556         if (!config->method) {
1557             g_critical("unsupported listen fd type");
1558             ret = EXIT_FAILURE;
1559             goto end;
1560         }
1561     } else if (config->channel_path == NULL) {
1562         if (strcmp(config->method, "virtio-serial") == 0) {
1563             /* try the default path for the virtio-serial port */
1564             config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1565         } else if (strcmp(config->method, "isa-serial") == 0) {
1566             /* try the default path for the serial port - COM1 */
1567             config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1568         } else {
1569             g_critical("must specify a path for this channel");
1570             ret = EXIT_FAILURE;
1571             goto end;
1572         }
1573     }
1574
1575     if (config->dumpconf) {
1576         config_dump(config);
1577         goto end;
1578     }
1579
1580     s = initialize_agent(config, socket_activation);
1581     if (!s) {
1582         g_critical("error initializing guest agent");
1583         goto end;
1584     }
1585
1586 #ifdef _WIN32
1587     if (config->daemonize) {
1588         SERVICE_TABLE_ENTRY service_table[] = {
1589             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1590         StartServiceCtrlDispatcher(service_table);
1591     } else {
1592         ret = run_agent(s);
1593     }
1594 #else
1595     ret = run_agent(s);
1596 #endif
1597
1598     cleanup_agent(s);
1599
1600 end:
1601     if (config->daemonize) {
1602         unlink(config->pid_filepath);
1603     }
1604
1605     config_free(config);
1606
1607     return ret;
1608 }