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