qga/main.c

   1 /*
   2  * QEMU Guest Agent
   3  *
   4  * Copyright IBM Corp. 2011
   5  *
   6  * Authors:
   7  *  Adam Litke        <aglitke@linux.vnet.ibm.com>
   8  *  Michael Roth      <mdroth@linux.vnet.ibm.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  11  * See the COPYING file in the top-level directory.
  12  */
  13
  14 #include "qemu/osdep.h"
  15 #include <getopt.h>
  16 #include <glib/gstdio.h>
  17 #ifndef _WIN32
  18 #include <syslog.h>
  19 #include <sys/wait.h>
  20 #endif
  21 #include "qemu-common.h"
  22 #include "qapi/qmp/json-parser.h"
  23 #include "qapi/qmp/qdict.h"
  24 #include "qapi/qmp/qjson.h"
  25 #include "guest-agent-core.h"
  26 #include "qga-qapi-init-commands.h"
  27 #include "qapi/qmp/qerror.h"
  28 #include "qapi/error.h"
  29 #include "channel.h"
  30 #include "qemu/cutils.h"
  31 #include "qemu/help_option.h"
  32 #include "qemu/sockets.h"
  33 #include "qemu/systemd.h"
  34 #include "qemu-version.h"
  35 #ifdef _WIN32
  36 #include <dbt.h>
  37 #include "qga/service-win32.h"
  38 #include "qga/vss-win32.h"
  39 #endif
  40 #ifdef __linux__
  41 #include <linux/fs.h>
  42 #ifdef FIFREEZE
  43 #define CONFIG_FSFREEZE
  44 #endif
  45 #endif
  46
  47 #ifndef _WIN32
  48 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
  49 #define QGA_STATE_RELATIVE_DIR  "run"
  50 #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
  51 #else
  52 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
  53 #define QGA_STATE_RELATIVE_DIR  "qemu-ga"
  54 #define QGA_SERIAL_PATH_DEFAULT "COM1"
  55 #endif
  56 #ifdef CONFIG_FSFREEZE
  57 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
  58 #endif
  59 #define QGA_SENTINEL_BYTE 0xFF
  60 #define QGA_CONF_DEFAULT CONFIG_QEMU_CONFDIR G_DIR_SEPARATOR_S "qemu-ga.conf"
  61 #define QGA_RETRY_INTERVAL 5
  62
  63 static struct {
  64     const char *state_dir;
  65     const char *pidfile;
  66 } dfl_pathnames;
  67
  68 typedef struct GAPersistentState {
  69 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
  70     int64_t fd_counter;
  71 } GAPersistentState;
  72
  73 typedef struct GAConfig GAConfig;
  74
  75 struct GAState {
  76     JSONMessageParser parser;
  77     GMainLoop *main_loop;
  78     GAChannel *channel;
  79     bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
  80     GACommandState *command_state;
  81     GLogLevelFlags log_level;
  82     FILE *log_file;
  83     bool logging_enabled;
  84 #ifdef _WIN32
  85     GAService service;
  86     HANDLE wakeup_event;
  87 #endif
  88     bool delimit_response;
  89     bool frozen;
  90     GList *blacklist;
  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_whitelist[] = {
 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_assert(dfl_pathnames.state_dir == NULL);
 133     g_assert(dfl_pathnames.pidfile == NULL);
 134     dfl_pathnames.state_dir = qemu_get_local_state_pathname(
 135       QGA_STATE_RELATIVE_DIR);
 136     dfl_pathnames.pidfile   = qemu_get_local_state_pathname(
 137       QGA_STATE_RELATIVE_DIR G_DIR_SEPARATOR_S "qemu-ga.pid");
 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     printf(
 227 "Usage: %s [-m <method> -p <path>] [<options>]\n"
 228 "QEMU Guest Agent " QEMU_FULL_VERSION "\n"
 229 QEMU_COPYRIGHT "\n"
 230 "\n"
 231 "  -m, --method      transport method: one of unix-listen, virtio-serial,\n"
 232 "                    isa-serial, or vsock-listen (virtio-serial is the default)\n"
 233 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
 234 "                    %s,\n"
 235 "                    the default for isa-serial is:\n"
 236 "                    %s).\n"
 237 "                    Socket addresses for vsock-listen are written as\n"
 238 "                    <cid>:<port>.\n"
 239 "  -l, --logfile     set logfile path, logs to stderr by default\n"
 240 "  -f, --pidfile     specify pidfile (default is %s)\n"
 241 #ifdef CONFIG_FSFREEZE
 242 "  -F, --fsfreeze-hook\n"
 243 "                    enable fsfreeze hook. Accepts an optional argument that\n"
 244 "                    specifies script to run on freeze/thaw. Script will be\n"
 245 "                    called with 'freeze'/'thaw' arguments accordingly.\n"
 246 "                    (default is %s)\n"
 247 "                    If using -F with an argument, do not follow -F with a\n"
 248 "                    space.\n"
 249 "                    (for example: -F/var/run/fsfreezehook.sh)\n"
 250 #endif
 251 "  -t, --statedir    specify dir to store state information (absolute paths\n"
 252 "                    only, default is %s)\n"
 253 "  -v, --verbose     log extra debugging information\n"
 254 "  -V, --version     print version information and exit\n"
 255 "  -d, --daemonize   become a daemon\n"
 256 #ifdef _WIN32
 257 "  -s, --service     service commands: install, uninstall, vss-install, vss-uninstall\n"
 258 #endif
 259 "  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\"\n"
 260 "                    to list available RPCs)\n"
 261 "  -D, --dump-conf   dump a qemu-ga config file based on current config\n"
 262 "                    options / command-line parameters to stdout\n"
 263 "  -r, --retry-path  attempt re-opening path if it's unavailable or closed\n"
 264 "                    due to an error which may be recoverable in the future\n"
 265 "                    (virtio-serial driver re-install, serial device hot\n"
 266 "                    plug/unplug, etc.)\n"
 267 "  -h, --help        display this help and exit\n"
 268 "\n"
 269 QEMU_HELP_BOTTOM "\n"
 270     , cmd, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT,
 271     dfl_pathnames.pidfile,
 272 #ifdef CONFIG_FSFREEZE
 273     QGA_FSFREEZE_HOOK_DEFAULT,
 274 #endif
 275     dfl_pathnames.state_dir);
 276 }
 277
 278 static const char *ga_log_level_str(GLogLevelFlags level)
 279 {
 280     switch (level & G_LOG_LEVEL_MASK) {
 281     case G_LOG_LEVEL_ERROR:
 282         return "error";
 283     case G_LOG_LEVEL_CRITICAL:
 284         return "critical";
 285     case G_LOG_LEVEL_WARNING:
 286         return "warning";
 287     case G_LOG_LEVEL_MESSAGE:
 288         return "message";
 289     case G_LOG_LEVEL_INFO:
 290         return "info";
 291     case G_LOG_LEVEL_DEBUG:
 292         return "debug";
 293     default:
 294         return "user";
 295     }
 296 }
 297
 298 bool ga_logging_enabled(GAState *s)
 299 {
 300     return s->logging_enabled;
 301 }
 302
 303 void ga_disable_logging(GAState *s)
 304 {
 305     s->logging_enabled = false;
 306 }
 307
 308 void ga_enable_logging(GAState *s)
 309 {
 310     s->logging_enabled = true;
 311 }
 312
 313 static void ga_log(const gchar *domain, GLogLevelFlags level,
 314                    const gchar *msg, gpointer opaque)
 315 {
 316     GAState *s = opaque;
 317     GTimeVal time;
 318     const char *level_str = ga_log_level_str(level);
 319
 320     if (!ga_logging_enabled(s)) {
 321         return;
 322     }
 323
 324     level &= G_LOG_LEVEL_MASK;
 325 #ifndef _WIN32
 326     if (g_strcmp0(domain, "syslog") == 0) {
 327         syslog(LOG_INFO, "%s: %s", level_str, msg);
 328     } else if (level & s->log_level) {
 329 #else
 330     if (level & s->log_level) {
 331 #endif
 332         g_get_current_time(&time);
 333         fprintf(s->log_file,
 334                 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
 335         fflush(s->log_file);
 336     }
 337 }
 338
 339 void ga_set_response_delimited(GAState *s)
 340 {
 341     s->delimit_response = true;
 342 }
 343
 344 static FILE *ga_open_logfile(const char *logfile)
 345 {
 346     FILE *f;
 347
 348     f = fopen(logfile, "a");
 349     if (!f) {
 350         return NULL;
 351     }
 352
 353     qemu_set_cloexec(fileno(f));
 354     return f;
 355 }
 356
 357 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
 358 {
 359     return strcmp(str1, str2);
 360 }
 361
 362 /* disable commands that aren't safe for fsfreeze */
 363 static void ga_disable_non_whitelisted(const QmpCommand *cmd, void *opaque)
 364 {
 365     bool whitelisted = false;
 366     int i = 0;
 367     const char *name = qmp_command_name(cmd);
 368
 369     while (ga_freeze_whitelist[i] != NULL) {
 370         if (strcmp(name, ga_freeze_whitelist[i]) == 0) {
 371             whitelisted = true;
 372         }
 373         i++;
 374     }
 375     if (!whitelisted) {
 376         g_debug("disabling command: %s", name);
 377         qmp_disable_command(&ga_commands, name, "the agent is in frozen state");
 378     }
 379 }
 380
 381 /* [re-]enable all commands, except those explicitly blacklisted by user */
 382 static void ga_enable_non_blacklisted(const QmpCommand *cmd, void *opaque)
 383 {
 384     GList *blacklist = opaque;
 385     const char *name = qmp_command_name(cmd);
 386
 387     if (g_list_find_custom(blacklist, name, ga_strcmp) == NULL &&
 388         !qmp_command_is_enabled(cmd)) {
 389         g_debug("enabling command: %s", name);
 390         qmp_enable_command(&ga_commands, name);
 391     }
 392 }
 393
 394 static bool ga_create_file(const char *path)
 395 {
 396     int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
 397     if (fd == -1) {
 398         g_warning("unable to open/create file %s: %s", path, strerror(errno));
 399         return false;
 400     }
 401     close(fd);
 402     return true;
 403 }
 404
 405 static bool ga_delete_file(const char *path)
 406 {
 407     int ret = unlink(path);
 408     if (ret == -1) {
 409         g_warning("unable to delete file: %s: %s", path, strerror(errno));
 410         return false;
 411     }
 412
 413     return true;
 414 }
 415
 416 bool ga_is_frozen(GAState *s)
 417 {
 418     return s->frozen;
 419 }
 420
 421 void ga_set_frozen(GAState *s)
 422 {
 423     if (ga_is_frozen(s)) {
 424         return;
 425     }
 426     /* disable all non-whitelisted (for frozen state) commands */
 427     qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
 428     g_warning("disabling logging due to filesystem freeze");
 429     ga_disable_logging(s);
 430     s->frozen = true;
 431     if (!ga_create_file(s->state_filepath_isfrozen)) {
 432         g_warning("unable to create %s, fsfreeze may not function properly",
 433                   s->state_filepath_isfrozen);
 434     }
 435 }
 436
 437 void ga_unset_frozen(GAState *s)
 438 {
 439     if (!ga_is_frozen(s)) {
 440         return;
 441     }
 442
 443     /* if we delayed creation/opening of pid/log files due to being
 444      * in a frozen state at start up, do it now
 445      */
 446     if (s->deferred_options.log_filepath) {
 447         s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
 448         if (!s->log_file) {
 449             s->log_file = stderr;
 450         }
 451         s->deferred_options.log_filepath = NULL;
 452     }
 453     ga_enable_logging(s);
 454     g_warning("logging re-enabled due to filesystem unfreeze");
 455     if (s->deferred_options.pid_filepath) {
 456         Error *err = NULL;
 457
 458         if (!qemu_write_pidfile(s->deferred_options.pid_filepath, &err)) {
 459             g_warning("%s", error_get_pretty(err));
 460             error_free(err);
 461         }
 462         s->deferred_options.pid_filepath = NULL;
 463     }
 464
 465     /* enable all disabled, non-blacklisted commands */
 466     qmp_for_each_command(&ga_commands, ga_enable_non_blacklisted, s->blacklist);
 467     s->frozen = false;
 468     if (!ga_delete_file(s->state_filepath_isfrozen)) {
 469         g_warning("unable to delete %s, fsfreeze may not function properly",
 470                   s->state_filepath_isfrozen);
 471     }
 472 }
 473
 474 #ifdef CONFIG_FSFREEZE
 475 const char *ga_fsfreeze_hook(GAState *s)
 476 {
 477     return s->fsfreeze_hook;
 478 }
 479 #endif
 480
 481 static void become_daemon(const char *pidfile)
 482 {
 483 #ifndef _WIN32
 484     pid_t pid, sid;
 485
 486     pid = fork();
 487     if (pid < 0) {
 488         exit(EXIT_FAILURE);
 489     }
 490     if (pid > 0) {
 491         exit(EXIT_SUCCESS);
 492     }
 493
 494     if (pidfile) {
 495         Error *err = NULL;
 496
 497         if (!qemu_write_pidfile(pidfile, &err)) {
 498             g_critical("%s", error_get_pretty(err));
 499             error_free(err);
 500             exit(EXIT_FAILURE);
 501         }
 502     }
 503
 504     umask(S_IRWXG | S_IRWXO);
 505     sid = setsid();
 506     if (sid < 0) {
 507         goto fail;
 508     }
 509     if ((chdir("/")) < 0) {
 510         goto fail;
 511     }
 512
 513     reopen_fd_to_null(STDIN_FILENO);
 514     reopen_fd_to_null(STDOUT_FILENO);
 515     reopen_fd_to_null(STDERR_FILENO);
 516     return;
 517
 518 fail:
 519     if (pidfile) {
 520         unlink(pidfile);
 521     }
 522     g_critical("failed to daemonize");
 523     exit(EXIT_FAILURE);
 524 #endif
 525 }
 526
 527 static int send_response(GAState *s, const QDict *rsp)
 528 {
 529     GString *response;
 530     GIOStatus status;
 531
 532     g_assert(s->channel);
 533
 534     if (!rsp) {
 535         return 0;
 536     }
 537
 538     response = qobject_to_json(QOBJECT(rsp));
 539     if (!response) {
 540         return -EINVAL;
 541     }
 542
 543     if (s->delimit_response) {
 544         s->delimit_response = false;
 545         g_string_prepend_c(response, QGA_SENTINEL_BYTE);
 546     }
 547
 548     g_string_append_c(response, '\n');
 549     status = ga_channel_write_all(s->channel, response->str, response->len);
 550     g_string_free(response, true);
 551     if (status != G_IO_STATUS_NORMAL) {
 552         return -EIO;
 553     }
 554
 555     return 0;
 556 }
 557
 558 /* handle requests/control events coming in over the channel */
 559 static void process_event(void *opaque, QObject *obj, Error *err)
 560 {
 561     GAState *s = opaque;
 562     QDict *rsp;
 563     int ret;
 564
 565     g_debug("process_event: called");
 566     assert(!obj != !err);
 567     if (err) {
 568         rsp = qmp_error_response(err);
 569         goto end;
 570     }
 571
 572     g_debug("processing command");
 573     rsp = qmp_dispatch(&ga_commands, obj, false, NULL);
 574
 575 end:
 576     ret = send_response(s, rsp);
 577     if (ret < 0) {
 578         g_warning("error sending error response: %s", strerror(-ret));
 579     }
 580     qobject_unref(rsp);
 581     qobject_unref(obj);
 582 }
 583
 584 /* false return signals GAChannel to close the current client connection */
 585 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 586 {
 587     GAState *s = data;
 588     gchar buf[QGA_READ_COUNT_DEFAULT + 1];
 589     gsize count;
 590     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 591     switch (status) {
 592     case G_IO_STATUS_ERROR:
 593         g_warning("error reading channel");
 594         stop_agent(s, false);
 595         return false;
 596     case G_IO_STATUS_NORMAL:
 597         buf[count] = 0;
 598         g_debug("read data, count: %d, data: %s", (int)count, buf);
 599         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 600         break;
 601     case G_IO_STATUS_EOF:
 602         g_debug("received EOF");
 603         if (!s->virtio) {
 604             return false;
 605         }
 606         /* fall through */
 607     case G_IO_STATUS_AGAIN:
 608         /* virtio causes us to spin here when no process is attached to
 609          * host-side chardev. sleep a bit to mitigate this
 610          */
 611         if (s->virtio) {
 612             usleep(100 * 1000);
 613         }
 614         return true;
 615     default:
 616         g_warning("unknown channel read status, closing");
 617         return false;
 618     }
 619     return true;
 620 }
 621
 622 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path,
 623                              int listen_fd)
 624 {
 625     GAChannelMethod channel_method;
 626
 627     if (strcmp(method, "virtio-serial") == 0) {
 628         s->virtio = true; /* virtio requires special handling in some cases */
 629         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 630     } else if (strcmp(method, "isa-serial") == 0) {
 631         channel_method = GA_CHANNEL_ISA_SERIAL;
 632     } else if (strcmp(method, "unix-listen") == 0) {
 633         channel_method = GA_CHANNEL_UNIX_LISTEN;
 634     } else if (strcmp(method, "vsock-listen") == 0) {
 635         channel_method = GA_CHANNEL_VSOCK_LISTEN;
 636     } else {
 637         g_critical("unsupported channel method/type: %s", method);
 638         return false;
 639     }
 640
 641     s->channel = ga_channel_new(channel_method, path, listen_fd,
 642                                 channel_event_cb, s);
 643     if (!s->channel) {
 644         g_critical("failed to create guest agent channel");
 645         return false;
 646     }
 647
 648     return true;
 649 }
 650
 651 #ifdef _WIN32
 652 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data)
 653 {
 654     DWORD ret = NO_ERROR;
 655     PDEV_BROADCAST_HDR broadcast_header = (PDEV_BROADCAST_HDR)data;
 656
 657     if (broadcast_header->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE) {
 658         switch (type) {
 659             /* Device inserted */
 660         case DBT_DEVICEARRIVAL:
 661             /* Start QEMU-ga's service */
 662             if (!SetEvent(ga_state->wakeup_event)) {
 663                 ret = GetLastError();
 664             }
 665             break;
 666             /* Device removed */
 667         case DBT_DEVICEQUERYREMOVE:
 668         case DBT_DEVICEREMOVEPENDING:
 669         case DBT_DEVICEREMOVECOMPLETE:
 670             /* Stop QEMU-ga's service */
 671             if (!ResetEvent(ga_state->wakeup_event)) {
 672                 ret = GetLastError();
 673             }
 674             break;
 675         default:
 676             ret = ERROR_CALL_NOT_IMPLEMENTED;
 677         }
 678     }
 679     return ret;
 680 }
 681
 682 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 683                                   LPVOID ctx)
 684 {
 685     DWORD ret = NO_ERROR;
 686     GAService *service = &ga_state->service;
 687
 688     switch (ctrl) {
 689     case SERVICE_CONTROL_STOP:
 690     case SERVICE_CONTROL_SHUTDOWN:
 691         quit_handler(SIGTERM);
 692         SetEvent(ga_state->wakeup_event);
 693         service->status.dwCurrentState = SERVICE_STOP_PENDING;
 694         SetServiceStatus(service->status_handle, &service->status);
 695         break;
 696     case SERVICE_CONTROL_DEVICEEVENT:
 697         handle_serial_device_events(type, data);
 698         break;
 699
 700     default:
 701         ret = ERROR_CALL_NOT_IMPLEMENTED;
 702     }
 703     return ret;
 704 }
 705
 706 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 707 {
 708     GAService *service = &ga_state->service;
 709
 710     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 711         service_ctrl_handler, NULL);
 712
 713     if (service->status_handle == 0) {
 714         g_critical("Failed to register extended requests function!\n");
 715         return;
 716     }
 717
 718     service->status.dwServiceType = SERVICE_WIN32;
 719     service->status.dwCurrentState = SERVICE_RUNNING;
 720     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 721     service->status.dwWin32ExitCode = NO_ERROR;
 722     service->status.dwServiceSpecificExitCode = NO_ERROR;
 723     service->status.dwCheckPoint = 0;
 724     service->status.dwWaitHint = 0;
 725     DEV_BROADCAST_DEVICEINTERFACE notification_filter;
 726     ZeroMemory(&notification_filter, sizeof(notification_filter));
 727     notification_filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
 728     notification_filter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
 729     notification_filter.dbcc_classguid = GUID_VIOSERIAL_PORT;
 730
 731     service->device_notification_handle =
 732         RegisterDeviceNotification(service->status_handle,
 733             &notification_filter, DEVICE_NOTIFY_SERVICE_HANDLE);
 734     if (!service->device_notification_handle) {
 735         g_critical("Failed to register device notification handle!\n");
 736         return;
 737     }
 738     SetServiceStatus(service->status_handle, &service->status);
 739
 740     run_agent(ga_state);
 741
 742     UnregisterDeviceNotification(service->device_notification_handle);
 743     service->status.dwCurrentState = SERVICE_STOPPED;
 744     SetServiceStatus(service->status_handle, &service->status);
 745 }
 746 #endif
 747
 748 static void set_persistent_state_defaults(GAPersistentState *pstate)
 749 {
 750     g_assert(pstate);
 751     pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
 752 }
 753
 754 static void persistent_state_from_keyfile(GAPersistentState *pstate,
 755                                           GKeyFile *keyfile)
 756 {
 757     g_assert(pstate);
 758     g_assert(keyfile);
 759     /* if any fields are missing, either because the file was tampered with
 760      * by agents of chaos, or because the field wasn't present at the time the
 761      * file was created, the best we can ever do is start over with the default
 762      * values. so load them now, and ignore any errors in accessing key-value
 763      * pairs
 764      */
 765     set_persistent_state_defaults(pstate);
 766
 767     if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
 768         pstate->fd_counter =
 769             g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
 770     }
 771 }
 772
 773 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
 774                                         GKeyFile *keyfile)
 775 {
 776     g_assert(pstate);
 777     g_assert(keyfile);
 778
 779     g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
 780 }
 781
 782 static gboolean write_persistent_state(const GAPersistentState *pstate,
 783                                        const gchar *path)
 784 {
 785     GKeyFile *keyfile = g_key_file_new();
 786     GError *gerr = NULL;
 787     gboolean ret = true;
 788     gchar *data = NULL;
 789     gsize data_len;
 790
 791     g_assert(pstate);
 792
 793     persistent_state_to_keyfile(pstate, keyfile);
 794     data = g_key_file_to_data(keyfile, &data_len, &gerr);
 795     if (gerr) {
 796         g_critical("failed to convert persistent state to string: %s",
 797                    gerr->message);
 798         ret = false;
 799         goto out;
 800     }
 801
 802     g_file_set_contents(path, data, data_len, &gerr);
 803     if (gerr) {
 804         g_critical("failed to write persistent state to %s: %s",
 805                     path, gerr->message);
 806         ret = false;
 807         goto out;
 808     }
 809
 810 out:
 811     if (gerr) {
 812         g_error_free(gerr);
 813     }
 814     if (keyfile) {
 815         g_key_file_free(keyfile);
 816     }
 817     g_free(data);
 818     return ret;
 819 }
 820
 821 static gboolean read_persistent_state(GAPersistentState *pstate,
 822                                       const gchar *path, gboolean frozen)
 823 {
 824     GKeyFile *keyfile = NULL;
 825     GError *gerr = NULL;
 826     struct stat st;
 827     gboolean ret = true;
 828
 829     g_assert(pstate);
 830
 831     if (stat(path, &st) == -1) {
 832         /* it's okay if state file doesn't exist, but any other error
 833          * indicates a permissions issue or some other misconfiguration
 834          * that we likely won't be able to recover from.
 835          */
 836         if (errno != ENOENT) {
 837             g_critical("unable to access state file at path %s: %s",
 838                        path, strerror(errno));
 839             ret = false;
 840             goto out;
 841         }
 842
 843         /* file doesn't exist. initialize state to default values and
 844          * attempt to save now. (we could wait till later when we have
 845          * modified state we need to commit, but if there's a problem,
 846          * such as a missing parent directory, we want to catch it now)
 847          *
 848          * there is a potential scenario where someone either managed to
 849          * update the agent from a version that didn't use a key store
 850          * while qemu-ga thought the filesystem was frozen, or
 851          * deleted the key store prior to issuing a fsfreeze, prior
 852          * to restarting the agent. in this case we go ahead and defer
 853          * initial creation till we actually have modified state to
 854          * write, otherwise fail to recover from freeze.
 855          */
 856         set_persistent_state_defaults(pstate);
 857         if (!frozen) {
 858             ret = write_persistent_state(pstate, path);
 859             if (!ret) {
 860                 g_critical("unable to create state file at path %s", path);
 861                 ret = false;
 862                 goto out;
 863             }
 864         }
 865         ret = true;
 866         goto out;
 867     }
 868
 869     keyfile = g_key_file_new();
 870     g_key_file_load_from_file(keyfile, path, 0, &gerr);
 871     if (gerr) {
 872         g_critical("error loading persistent state from path: %s, %s",
 873                    path, gerr->message);
 874         ret = false;
 875         goto out;
 876     }
 877
 878     persistent_state_from_keyfile(pstate, keyfile);
 879
 880 out:
 881     if (keyfile) {
 882         g_key_file_free(keyfile);
 883     }
 884     if (gerr) {
 885         g_error_free(gerr);
 886     }
 887
 888     return ret;
 889 }
 890
 891 int64_t ga_get_fd_handle(GAState *s, Error **errp)
 892 {
 893     int64_t handle;
 894
 895     g_assert(s->pstate_filepath);
 896     /* we blacklist commands and avoid operations that potentially require
 897      * writing to disk when we're in a frozen state. this includes opening
 898      * new files, so we should never get here in that situation
 899      */
 900     g_assert(!ga_is_frozen(s));
 901
 902     handle = s->pstate.fd_counter++;
 903
 904     /* This should never happen on a reasonable timeframe, as guest-file-open
 905      * would have to be issued 2^63 times */
 906     if (s->pstate.fd_counter == INT64_MAX) {
 907         abort();
 908     }
 909
 910     if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
 911         error_setg(errp, "failed to commit persistent state to disk");
 912         return -1;
 913     }
 914
 915     return handle;
 916 }
 917
 918 static void ga_print_cmd(const QmpCommand *cmd, void *opaque)
 919 {
 920     printf("%s\n", qmp_command_name(cmd));
 921 }
 922
 923 static GList *split_list(const gchar *str, const gchar *delim)
 924 {
 925     GList *list = NULL;
 926     int i;
 927     gchar **strv;
 928
 929     strv = g_strsplit(str, delim, -1);
 930     for (i = 0; strv[i]; i++) {
 931         list = g_list_prepend(list, strv[i]);
 932     }
 933     g_free(strv);
 934
 935     return list;
 936 }
 937
 938 struct GAConfig {
 939     char *channel_path;
 940     char *method;
 941     char *log_filepath;
 942     char *pid_filepath;
 943 #ifdef CONFIG_FSFREEZE
 944     char *fsfreeze_hook;
 945 #endif
 946     char *state_dir;
 947 #ifdef _WIN32
 948     const char *service;
 949 #endif
 950     gchar *bliststr; /* blacklist may point to this string */
 951     GList *blacklist;
 952     int daemonize;
 953     GLogLevelFlags log_level;
 954     int dumpconf;
 955     bool retry_path;
 956 };
 957
 958 static void config_load(GAConfig *config)
 959 {
 960     GError *gerr = NULL;
 961     GKeyFile *keyfile;
 962     g_autofree char *conf = g_strdup(g_getenv("QGA_CONF")) ?: get_relocated_path(QGA_CONF_DEFAULT);
 963
 964     /* read system config */
 965     keyfile = g_key_file_new();
 966     if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
 967         goto end;
 968     }
 969     if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
 970         config->daemonize =
 971             g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
 972     }
 973     if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
 974         config->method =
 975             g_key_file_get_string(keyfile, "general", "method", &gerr);
 976     }
 977     if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
 978         config->channel_path =
 979             g_key_file_get_string(keyfile, "general", "path", &gerr);
 980     }
 981     if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
 982         config->log_filepath =
 983             g_key_file_get_string(keyfile, "general", "logfile", &gerr);
 984     }
 985     if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
 986         config->pid_filepath =
 987             g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
 988     }
 989 #ifdef CONFIG_FSFREEZE
 990     if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
 991         config->fsfreeze_hook =
 992             g_key_file_get_string(keyfile,
 993                                   "general", "fsfreeze-hook", &gerr);
 994     }
 995 #endif
 996     if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
 997         config->state_dir =
 998             g_key_file_get_string(keyfile, "general", "statedir", &gerr);
 999     }
1000     if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
1001         g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
1002         /* enable all log levels */
1003         config->log_level = G_LOG_LEVEL_MASK;
1004     }
1005     if (g_key_file_has_key(keyfile, "general", "retry-path", NULL)) {
1006         config->retry_path =
1007             g_key_file_get_boolean(keyfile, "general", "retry-path", &gerr);
1008     }
1009     if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
1010         config->bliststr =
1011             g_key_file_get_string(keyfile, "general", "blacklist", &gerr);
1012         config->blacklist = g_list_concat(config->blacklist,
1013                                           split_list(config->bliststr, ","));
1014     }
1015
1016 end:
1017     g_key_file_free(keyfile);
1018     if (gerr &&
1019         !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
1020         g_critical("error loading configuration from path: %s, %s",
1021                    conf, gerr->message);
1022         exit(EXIT_FAILURE);
1023     }
1024     g_clear_error(&gerr);
1025 }
1026
1027 static gchar *list_join(GList *list, const gchar separator)
1028 {
1029     GString *str = g_string_new("");
1030
1031     while (list) {
1032         str = g_string_append(str, (gchar *)list->data);
1033         list = g_list_next(list);
1034         if (list) {
1035             str = g_string_append_c(str, separator);
1036         }
1037     }
1038
1039     return g_string_free(str, FALSE);
1040 }
1041
1042 static void config_dump(GAConfig *config)
1043 {
1044     GError *error = NULL;
1045     GKeyFile *keyfile;
1046     gchar *tmp;
1047
1048     keyfile = g_key_file_new();
1049     g_assert(keyfile);
1050
1051     g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1052     g_key_file_set_string(keyfile, "general", "method", config->method);
1053     if (config->channel_path) {
1054         g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1055     }
1056     if (config->log_filepath) {
1057         g_key_file_set_string(keyfile, "general", "logfile",
1058                               config->log_filepath);
1059     }
1060     g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1061 #ifdef CONFIG_FSFREEZE
1062     if (config->fsfreeze_hook) {
1063         g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1064                               config->fsfreeze_hook);
1065     }
1066 #endif
1067     g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1068     g_key_file_set_boolean(keyfile, "general", "verbose",
1069                            config->log_level == G_LOG_LEVEL_MASK);
1070     g_key_file_set_boolean(keyfile, "general", "retry-path",
1071                            config->retry_path);
1072     tmp = list_join(config->blacklist, ',');
1073     g_key_file_set_string(keyfile, "general", "blacklist", tmp);
1074     g_free(tmp);
1075
1076     tmp = g_key_file_to_data(keyfile, NULL, &error);
1077     if (error) {
1078         g_critical("Failed to dump keyfile: %s", error->message);
1079         g_clear_error(&error);
1080     } else {
1081         printf("%s", tmp);
1082     }
1083
1084     g_free(tmp);
1085     g_key_file_free(keyfile);
1086 }
1087
1088 static void config_parse(GAConfig *config, int argc, char **argv)
1089 {
1090     const char *sopt = "hVvdm:p:l:f:F::b:s:t:Dr";
1091     int opt_ind = 0, ch;
1092     const struct option lopt[] = {
1093         { "help", 0, NULL, 'h' },
1094         { "version", 0, NULL, 'V' },
1095         { "dump-conf", 0, NULL, 'D' },
1096         { "logfile", 1, NULL, 'l' },
1097         { "pidfile", 1, NULL, 'f' },
1098 #ifdef CONFIG_FSFREEZE
1099         { "fsfreeze-hook", 2, NULL, 'F' },
1100 #endif
1101         { "verbose", 0, NULL, 'v' },
1102         { "method", 1, NULL, 'm' },
1103         { "path", 1, NULL, 'p' },
1104         { "daemonize", 0, NULL, 'd' },
1105         { "blacklist", 1, NULL, 'b' },
1106 #ifdef _WIN32
1107         { "service", 1, NULL, 's' },
1108 #endif
1109         { "statedir", 1, NULL, 't' },
1110         { "retry-path", 0, NULL, 'r' },
1111         { NULL, 0, NULL, 0 }
1112     };
1113
1114     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1115         switch (ch) {
1116         case 'm':
1117             g_free(config->method);
1118             config->method = g_strdup(optarg);
1119             break;
1120         case 'p':
1121             g_free(config->channel_path);
1122             config->channel_path = g_strdup(optarg);
1123             break;
1124         case 'l':
1125             g_free(config->log_filepath);
1126             config->log_filepath = g_strdup(optarg);
1127             break;
1128         case 'f':
1129             g_free(config->pid_filepath);
1130             config->pid_filepath = g_strdup(optarg);
1131             break;
1132 #ifdef CONFIG_FSFREEZE
1133         case 'F':
1134             g_free(config->fsfreeze_hook);
1135             config->fsfreeze_hook = optarg ? g_strdup(optarg) : get_relocated_path(QGA_FSFREEZE_HOOK_DEFAULT);
1136             break;
1137 #endif
1138         case 't':
1139             g_free(config->state_dir);
1140             config->state_dir = g_strdup(optarg);
1141             break;
1142         case 'v':
1143             /* enable all log levels */
1144             config->log_level = G_LOG_LEVEL_MASK;
1145             break;
1146         case 'V':
1147             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1148             exit(EXIT_SUCCESS);
1149         case 'd':
1150             config->daemonize = 1;
1151             break;
1152         case 'D':
1153             config->dumpconf = 1;
1154             break;
1155         case 'r':
1156             config->retry_path = true;
1157             break;
1158         case 'b': {
1159             if (is_help_option(optarg)) {
1160                 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1161                 exit(EXIT_SUCCESS);
1162             }
1163             config->blacklist = g_list_concat(config->blacklist,
1164                                              split_list(optarg, ","));
1165             break;
1166         }
1167 #ifdef _WIN32
1168         case 's':
1169             config->service = optarg;
1170             if (strcmp(config->service, "install") == 0) {
1171                 if (ga_install_vss_provider()) {
1172                     exit(EXIT_FAILURE);
1173                 }
1174                 if (ga_install_service(config->channel_path,
1175                                        config->log_filepath, config->state_dir)) {
1176                     exit(EXIT_FAILURE);
1177                 }
1178                 exit(EXIT_SUCCESS);
1179             } else if (strcmp(config->service, "uninstall") == 0) {
1180                 ga_uninstall_vss_provider();
1181                 exit(ga_uninstall_service());
1182             } else if (strcmp(config->service, "vss-install") == 0) {
1183                 if (ga_install_vss_provider()) {
1184                     exit(EXIT_FAILURE);
1185                 }
1186                 exit(EXIT_SUCCESS);
1187             } else if (strcmp(config->service, "vss-uninstall") == 0) {
1188                 ga_uninstall_vss_provider();
1189                 exit(EXIT_SUCCESS);
1190             } else {
1191                 printf("Unknown service command.\n");
1192                 exit(EXIT_FAILURE);
1193             }
1194             break;
1195 #endif
1196         case 'h':
1197             usage(argv[0]);
1198             exit(EXIT_SUCCESS);
1199         case '?':
1200             g_print("Unknown option, try '%s --help' for more information.\n",
1201                     argv[0]);
1202             exit(EXIT_FAILURE);
1203         }
1204     }
1205 }
1206
1207 static void config_free(GAConfig *config)
1208 {
1209     g_free(config->method);
1210     g_free(config->log_filepath);
1211     g_free(config->pid_filepath);
1212     g_free(config->state_dir);
1213     g_free(config->channel_path);
1214     g_free(config->bliststr);
1215 #ifdef CONFIG_FSFREEZE
1216     g_free(config->fsfreeze_hook);
1217 #endif
1218     g_list_free_full(config->blacklist, g_free);
1219     g_free(config);
1220 }
1221
1222 static bool check_is_frozen(GAState *s)
1223 {
1224 #ifndef _WIN32
1225     /* check if a previous instance of qemu-ga exited with filesystems' state
1226      * marked as frozen. this could be a stale value (a non-qemu-ga process
1227      * or reboot may have since unfrozen them), but better to require an
1228      * uneeded unfreeze than to risk hanging on start-up
1229      */
1230     struct stat st;
1231     if (stat(s->state_filepath_isfrozen, &st) == -1) {
1232         /* it's okay if the file doesn't exist, but if we can't access for
1233          * some other reason, such as permissions, there's a configuration
1234          * that needs to be addressed. so just bail now before we get into
1235          * more trouble later
1236          */
1237         if (errno != ENOENT) {
1238             g_critical("unable to access state file at path %s: %s",
1239                        s->state_filepath_isfrozen, strerror(errno));
1240             return EXIT_FAILURE;
1241         }
1242     } else {
1243         g_warning("previous instance appears to have exited with frozen"
1244                   " filesystems. deferring logging/pidfile creation and"
1245                   " disabling non-fsfreeze-safe commands until"
1246                   " guest-fsfreeze-thaw is issued, or filesystems are"
1247                   " manually unfrozen and the file %s is removed",
1248                   s->state_filepath_isfrozen);
1249         return true;
1250     }
1251 #endif
1252     return false;
1253 }
1254
1255 static GAState *initialize_agent(GAConfig *config, int socket_activation)
1256 {
1257     GAState *s = g_new0(GAState, 1);
1258
1259     g_assert(ga_state == NULL);
1260
1261     s->log_level = config->log_level;
1262     s->log_file = stderr;
1263 #ifdef CONFIG_FSFREEZE
1264     s->fsfreeze_hook = config->fsfreeze_hook;
1265 #endif
1266     s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1267     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1268                                                  config->state_dir);
1269     s->frozen = check_is_frozen(s);
1270
1271     g_log_set_default_handler(ga_log, s);
1272     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1273     ga_enable_logging(s);
1274
1275 #ifdef _WIN32
1276     /* On win32 the state directory is application specific (be it the default
1277      * or a user override). We got past the command line parsing; let's create
1278      * the directory (with any intermediate directories). If we run into an
1279      * error later on, we won't try to clean up the directory, it is considered
1280      * persistent.
1281      */
1282     if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1283         g_critical("unable to create (an ancestor of) the state directory"
1284                    " '%s': %s", config->state_dir, strerror(errno));
1285         return NULL;
1286     }
1287 #endif
1288
1289     if (ga_is_frozen(s)) {
1290         if (config->daemonize) {
1291             /* delay opening/locking of pidfile till filesystems are unfrozen */
1292             s->deferred_options.pid_filepath = config->pid_filepath;
1293             become_daemon(NULL);
1294         }
1295         if (config->log_filepath) {
1296             /* delay opening the log file till filesystems are unfrozen */
1297             s->deferred_options.log_filepath = config->log_filepath;
1298         }
1299         ga_disable_logging(s);
1300         qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
1301     } else {
1302         if (config->daemonize) {
1303             become_daemon(config->pid_filepath);
1304         }
1305         if (config->log_filepath) {
1306             FILE *log_file = ga_open_logfile(config->log_filepath);
1307             if (!log_file) {
1308                 g_critical("unable to open specified log file: %s",
1309                            strerror(errno));
1310                 return NULL;
1311             }
1312             s->log_file = log_file;
1313         }
1314     }
1315
1316     /* load persistent state from disk */
1317     if (!read_persistent_state(&s->pstate,
1318                                s->pstate_filepath,
1319                                ga_is_frozen(s))) {
1320         g_critical("failed to load persistent state");
1321         return NULL;
1322     }
1323
1324     config->blacklist = ga_command_blacklist_init(config->blacklist);
1325     if (config->blacklist) {
1326         GList *l = config->blacklist;
1327         s->blacklist = config->blacklist;
1328         do {
1329             g_debug("disabling command: %s", (char *)l->data);
1330             qmp_disable_command(&ga_commands, l->data, NULL);
1331             l = g_list_next(l);
1332         } while (l);
1333     }
1334     s->command_state = ga_command_state_new();
1335     ga_command_state_init(s, s->command_state);
1336     ga_command_state_init_all(s->command_state);
1337     json_message_parser_init(&s->parser, process_event, s, NULL);
1338
1339 #ifndef _WIN32
1340     if (!register_signal_handlers()) {
1341         g_critical("failed to register signal handlers");
1342         return NULL;
1343     }
1344 #endif
1345
1346     s->main_loop = g_main_loop_new(NULL, false);
1347
1348     s->config = config;
1349     s->socket_activation = socket_activation;
1350
1351 #ifdef _WIN32
1352     s->wakeup_event = CreateEvent(NULL, TRUE, FALSE, TEXT("WakeUp"));
1353     if (s->wakeup_event == NULL) {
1354         g_critical("CreateEvent failed");
1355         return NULL;
1356     }
1357 #endif
1358
1359     ga_state = s;
1360     return s;
1361 }
1362
1363 static void cleanup_agent(GAState *s)
1364 {
1365 #ifdef _WIN32
1366     CloseHandle(s->wakeup_event);
1367 #endif
1368     if (s->command_state) {
1369         ga_command_state_cleanup_all(s->command_state);
1370         ga_command_state_free(s->command_state);
1371         json_message_parser_destroy(&s->parser);
1372     }
1373     g_free(s->pstate_filepath);
1374     g_free(s->state_filepath_isfrozen);
1375     if (s->main_loop) {
1376         g_main_loop_unref(s->main_loop);
1377     }
1378     g_free(s);
1379     ga_state = NULL;
1380 }
1381
1382 static int run_agent_once(GAState *s)
1383 {
1384     if (!channel_init(s, s->config->method, s->config->channel_path,
1385                       s->socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
1386         g_critical("failed to initialize guest agent channel");
1387         return EXIT_FAILURE;
1388     }
1389
1390     g_main_loop_run(ga_state->main_loop);
1391
1392     if (s->channel) {
1393         ga_channel_free(s->channel);
1394     }
1395
1396     return EXIT_SUCCESS;
1397 }
1398
1399 static void wait_for_channel_availability(GAState *s)
1400 {
1401     g_warning("waiting for channel path...");
1402 #ifndef _WIN32
1403     sleep(QGA_RETRY_INTERVAL);
1404 #else
1405     DWORD dwWaitResult;
1406
1407     dwWaitResult = WaitForSingleObject(s->wakeup_event, INFINITE);
1408
1409     switch (dwWaitResult) {
1410     case WAIT_OBJECT_0:
1411         break;
1412     case WAIT_TIMEOUT:
1413         break;
1414     default:
1415         g_critical("WaitForSingleObject failed");
1416     }
1417 #endif
1418 }
1419
1420 static int run_agent(GAState *s)
1421 {
1422     int ret = EXIT_SUCCESS;
1423
1424     s->force_exit = false;
1425
1426     do {
1427         ret = run_agent_once(s);
1428         if (s->config->retry_path && !s->force_exit) {
1429             g_warning("agent stopped unexpectedly, restarting...");
1430             wait_for_channel_availability(s);
1431         }
1432     } while (s->config->retry_path && !s->force_exit);
1433
1434     return ret;
1435 }
1436
1437 static void stop_agent(GAState *s, bool requested)
1438 {
1439     if (!s->force_exit) {
1440         s->force_exit = requested;
1441     }
1442
1443     if (g_main_loop_is_running(s->main_loop)) {
1444         g_main_loop_quit(s->main_loop);
1445     }
1446 }
1447
1448 int main(int argc, char **argv)
1449 {
1450     int ret = EXIT_SUCCESS;
1451     GAState *s;
1452     GAConfig *config = g_new0(GAConfig, 1);
1453     int socket_activation;
1454
1455     config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1456
1457     qemu_init_exec_dir(argv[0]);
1458     qga_qmp_init_marshal(&ga_commands);
1459
1460     init_dfl_pathnames();
1461     config_load(config);
1462     config_parse(config, argc, argv);
1463
1464     if (config->pid_filepath == NULL) {
1465         config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1466     }
1467
1468     if (config->state_dir == NULL) {
1469         config->state_dir = g_strdup(dfl_pathnames.state_dir);
1470     }
1471
1472     if (config->method == NULL) {
1473         config->method = g_strdup("virtio-serial");
1474     }
1475
1476     socket_activation = check_socket_activation();
1477     if (socket_activation > 1) {
1478         g_critical("qemu-ga only supports listening on one socket");
1479         ret = EXIT_FAILURE;
1480         goto end;
1481     }
1482     if (socket_activation) {
1483         SocketAddress *addr;
1484
1485         g_free(config->method);
1486         g_free(config->channel_path);
1487         config->method = NULL;
1488         config->channel_path = NULL;
1489
1490         addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL);
1491         if (addr) {
1492             if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
1493                 config->method = g_strdup("unix-listen");
1494             } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
1495                 config->method = g_strdup("vsock-listen");
1496             }
1497
1498             qapi_free_SocketAddress(addr);
1499         }
1500
1501         if (!config->method) {
1502             g_critical("unsupported listen fd type");
1503             ret = EXIT_FAILURE;
1504             goto end;
1505         }
1506     } else if (config->channel_path == NULL) {
1507         if (strcmp(config->method, "virtio-serial") == 0) {
1508             /* try the default path for the virtio-serial port */
1509             config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1510         } else if (strcmp(config->method, "isa-serial") == 0) {
1511             /* try the default path for the serial port - COM1 */
1512             config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1513         } else {
1514             g_critical("must specify a path for this channel");
1515             ret = EXIT_FAILURE;
1516             goto end;
1517         }
1518     }
1519
1520     if (config->dumpconf) {
1521         config_dump(config);
1522         goto end;
1523     }
1524
1525     s = initialize_agent(config, socket_activation);
1526     if (!s) {
1527         g_critical("error initializing guest agent");
1528         goto end;
1529     }
1530
1531 #ifdef _WIN32
1532     if (config->daemonize) {
1533         SERVICE_TABLE_ENTRY service_table[] = {
1534             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1535         StartServiceCtrlDispatcher(service_table);
1536     } else {
1537         ret = run_agent(s);
1538     }
1539 #else
1540     ret = run_agent(s);
1541 #endif
1542
1543     cleanup_agent(s);
1544
1545 end:
1546     if (config->daemonize) {
1547         unlink(config->pid_filepath);
1548     }
1549
1550     config_free(config);
1551
1552     return ret;
1553 }