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