qga/main.c

   1 /*
   2  * QEMU Guest Agent
   3  *
   4  * Copyright IBM Corp. 2011
   5  *
   6  * Authors:
   7  *  Adam Litke        <aglitke@linux.vnet.ibm.com>
   8  *  Michael Roth      <mdroth@linux.vnet.ibm.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  11  * See the COPYING file in the top-level directory.
  12  */
  13
  14 #include "qemu/osdep.h"
  15 #include <getopt.h>
  16 #include <glib/gstdio.h>
  17 #ifndef _WIN32
  18 #include <syslog.h>
  19 #include <sys/wait.h>
  20 #endif
  21 #include "qemu/help-texts.h"
  22 #include "qapi/qmp/json-parser.h"
  23 #include "qapi/qmp/qdict.h"
  24 #include "qapi/qmp/qjson.h"
  25 #include "guest-agent-core.h"
  26 #include "qga-qapi-init-commands.h"
  27 #include "qapi/qmp/qerror.h"
  28 #include "qapi/error.h"
  29 #include "channel.h"
  30 #include "qemu/cutils.h"
  31 #include "qemu/help_option.h"
  32 #include "qemu/sockets.h"
  33 #include "qemu/systemd.h"
  34 #include "qemu-version.h"
  35 #ifdef _WIN32
  36 #include <dbt.h>
  37 #include "qga/service-win32.h"
  38 #include "qga/vss-win32.h"
  39 #endif
  40 #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_autofree char *state = qemu_get_local_state_dir();
 133
 134     g_assert(dfl_pathnames.state_dir == NULL);
 135     g_assert(dfl_pathnames.pidfile == NULL);
 136     dfl_pathnames.state_dir = g_build_filename(state, QGA_STATE_RELATIVE_DIR, NULL);
 137     dfl_pathnames.pidfile = g_build_filename(state, QGA_STATE_RELATIVE_DIR, "qemu-ga.pid", NULL);
 138 }
 139
 140 static void quit_handler(int sig)
 141 {
 142     /* if we're frozen, don't exit unless we're absolutely forced to,
 143      * because it's basically impossible for graceful exit to complete
 144      * unless all log/pid files are on unfreezable filesystems. there's
 145      * also a very likely chance killing the agent before unfreezing
 146      * the filesystems is a mistake (or will be viewed as one later).
 147      * On Windows the freeze interval is limited to 10 seconds, so
 148      * we should quit, but first we should wait for the timeout, thaw
 149      * the filesystem and quit.
 150      */
 151     if (ga_is_frozen(ga_state)) {
 152 #ifdef _WIN32
 153         int i = 0;
 154         Error *err = NULL;
 155         HANDLE hEventTimeout;
 156
 157         g_debug("Thawing filesystems before exiting");
 158
 159         hEventTimeout = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_TIMEOUT);
 160         if (hEventTimeout) {
 161             WaitForSingleObject(hEventTimeout, 0);
 162             CloseHandle(hEventTimeout);
 163         }
 164         qga_vss_fsfreeze(&i, false, NULL, &err);
 165         if (err) {
 166             g_debug("Error unfreezing filesystems prior to exiting: %s",
 167                 error_get_pretty(err));
 168             error_free(err);
 169         }
 170 #else
 171         return;
 172 #endif
 173     }
 174     g_debug("received signal num %d, quitting", sig);
 175
 176     stop_agent(ga_state, true);
 177 }
 178
 179 #ifndef _WIN32
 180 static gboolean register_signal_handlers(void)
 181 {
 182     struct sigaction sigact;
 183     int ret;
 184
 185     memset(&sigact, 0, sizeof(struct sigaction));
 186     sigact.sa_handler = quit_handler;
 187
 188     ret = sigaction(SIGINT, &sigact, NULL);
 189     if (ret == -1) {
 190         g_error("error configuring signal handler: %s", strerror(errno));
 191     }
 192     ret = sigaction(SIGTERM, &sigact, NULL);
 193     if (ret == -1) {
 194         g_error("error configuring signal handler: %s", strerror(errno));
 195     }
 196
 197     sigact.sa_handler = SIG_IGN;
 198     if (sigaction(SIGPIPE, &sigact, NULL) != 0) {
 199         g_error("error configuring SIGPIPE signal handler: %s",
 200                 strerror(errno));
 201     }
 202
 203     return true;
 204 }
 205
 206 /* TODO: use this in place of all post-fork() fclose(std*) callers */
 207 void reopen_fd_to_null(int fd)
 208 {
 209     int nullfd;
 210
 211     nullfd = open("/dev/null", O_RDWR);
 212     if (nullfd < 0) {
 213         return;
 214     }
 215
 216     dup2(nullfd, fd);
 217
 218     if (nullfd != fd) {
 219         close(nullfd);
 220     }
 221 }
 222 #endif
 223
 224 static void usage(const char *cmd)
 225 {
 226     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     const char *level_str = ga_log_level_str(level);
 318
 319     if (!ga_logging_enabled(s)) {
 320         return;
 321     }
 322
 323     level &= G_LOG_LEVEL_MASK;
 324 #ifndef _WIN32
 325     if (g_strcmp0(domain, "syslog") == 0) {
 326         syslog(LOG_INFO, "%s: %s", level_str, msg);
 327     } else if (level & s->log_level) {
 328 #else
 329     if (level & s->log_level) {
 330 #endif
 331         g_autoptr(GDateTime) now = g_date_time_new_now_utc();
 332         g_autofree char *nowstr = g_date_time_format(now, "%s.%f");
 333         fprintf(s->log_file, "%s: %s: %s\n", nowstr, level_str, msg);
 334         fflush(s->log_file);
 335     }
 336 }
 337
 338 void ga_set_response_delimited(GAState *s)
 339 {
 340     s->delimit_response = true;
 341 }
 342
 343 static FILE *ga_open_logfile(const char *logfile)
 344 {
 345     FILE *f;
 346
 347     f = fopen(logfile, "a");
 348     if (!f) {
 349         return NULL;
 350     }
 351
 352     qemu_set_cloexec(fileno(f));
 353     return f;
 354 }
 355
 356 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
 357 {
 358     return strcmp(str1, str2);
 359 }
 360
 361 /* disable commands that aren't safe for fsfreeze */
 362 static void ga_disable_non_whitelisted(const QmpCommand *cmd, void *opaque)
 363 {
 364     bool whitelisted = false;
 365     int i = 0;
 366     const char *name = qmp_command_name(cmd);
 367
 368     while (ga_freeze_whitelist[i] != NULL) {
 369         if (strcmp(name, ga_freeze_whitelist[i]) == 0) {
 370             whitelisted = true;
 371         }
 372         i++;
 373     }
 374     if (!whitelisted) {
 375         g_debug("disabling command: %s", name);
 376         qmp_disable_command(&ga_commands, name, "the agent is in frozen state");
 377     }
 378 }
 379
 380 /* [re-]enable all commands, except those explicitly blacklisted by user */
 381 static void ga_enable_non_blacklisted(const QmpCommand *cmd, void *opaque)
 382 {
 383     GList *blacklist = opaque;
 384     const char *name = qmp_command_name(cmd);
 385
 386     if (g_list_find_custom(blacklist, name, ga_strcmp) == NULL &&
 387         !qmp_command_is_enabled(cmd)) {
 388         g_debug("enabling command: %s", name);
 389         qmp_enable_command(&ga_commands, name);
 390     }
 391 }
 392
 393 static bool ga_create_file(const char *path)
 394 {
 395     int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
 396     if (fd == -1) {
 397         g_warning("unable to open/create file %s: %s", path, strerror(errno));
 398         return false;
 399     }
 400     close(fd);
 401     return true;
 402 }
 403
 404 static bool ga_delete_file(const char *path)
 405 {
 406     int ret = unlink(path);
 407     if (ret == -1) {
 408         g_warning("unable to delete file: %s: %s", path, strerror(errno));
 409         return false;
 410     }
 411
 412     return true;
 413 }
 414
 415 bool ga_is_frozen(GAState *s)
 416 {
 417     return s->frozen;
 418 }
 419
 420 void ga_set_frozen(GAState *s)
 421 {
 422     if (ga_is_frozen(s)) {
 423         return;
 424     }
 425     /* disable all non-whitelisted (for frozen state) commands */
 426     qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
 427     g_warning("disabling logging due to filesystem freeze");
 428     ga_disable_logging(s);
 429     s->frozen = true;
 430     if (!ga_create_file(s->state_filepath_isfrozen)) {
 431         g_warning("unable to create %s, fsfreeze may not function properly",
 432                   s->state_filepath_isfrozen);
 433     }
 434 }
 435
 436 void ga_unset_frozen(GAState *s)
 437 {
 438     if (!ga_is_frozen(s)) {
 439         return;
 440     }
 441
 442     /* if we delayed creation/opening of pid/log files due to being
 443      * in a frozen state at start up, do it now
 444      */
 445     if (s->deferred_options.log_filepath) {
 446         s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
 447         if (!s->log_file) {
 448             s->log_file = stderr;
 449         }
 450         s->deferred_options.log_filepath = NULL;
 451     }
 452     ga_enable_logging(s);
 453     g_warning("logging re-enabled due to filesystem unfreeze");
 454     if (s->deferred_options.pid_filepath) {
 455         Error *err = NULL;
 456
 457         if (!qemu_write_pidfile(s->deferred_options.pid_filepath, &err)) {
 458             g_warning("%s", error_get_pretty(err));
 459             error_free(err);
 460         }
 461         s->deferred_options.pid_filepath = NULL;
 462     }
 463
 464     /* enable all disabled, non-blacklisted commands */
 465     qmp_for_each_command(&ga_commands, ga_enable_non_blacklisted, s->blacklist);
 466     s->frozen = false;
 467     if (!ga_delete_file(s->state_filepath_isfrozen)) {
 468         g_warning("unable to delete %s, fsfreeze may not function properly",
 469                   s->state_filepath_isfrozen);
 470     }
 471 }
 472
 473 #ifdef CONFIG_FSFREEZE
 474 const char *ga_fsfreeze_hook(GAState *s)
 475 {
 476     return s->fsfreeze_hook;
 477 }
 478 #endif
 479
 480 static void become_daemon(const char *pidfile)
 481 {
 482 #ifndef _WIN32
 483     pid_t pid, sid;
 484
 485     pid = fork();
 486     if (pid < 0) {
 487         exit(EXIT_FAILURE);
 488     }
 489     if (pid > 0) {
 490         exit(EXIT_SUCCESS);
 491     }
 492
 493     if (pidfile) {
 494         Error *err = NULL;
 495
 496         if (!qemu_write_pidfile(pidfile, &err)) {
 497             g_critical("%s", error_get_pretty(err));
 498             error_free(err);
 499             exit(EXIT_FAILURE);
 500         }
 501     }
 502
 503     umask(S_IRWXG | S_IRWXO);
 504     sid = setsid();
 505     if (sid < 0) {
 506         goto fail;
 507     }
 508     if ((chdir("/")) < 0) {
 509         goto fail;
 510     }
 511
 512     reopen_fd_to_null(STDIN_FILENO);
 513     reopen_fd_to_null(STDOUT_FILENO);
 514     reopen_fd_to_null(STDERR_FILENO);
 515     return;
 516
 517 fail:
 518     if (pidfile) {
 519         unlink(pidfile);
 520     }
 521     g_critical("failed to daemonize");
 522     exit(EXIT_FAILURE);
 523 #endif
 524 }
 525
 526 static int send_response(GAState *s, const QDict *rsp)
 527 {
 528     GString *response;
 529     GIOStatus status;
 530
 531     g_assert(s->channel);
 532
 533     if (!rsp) {
 534         return 0;
 535     }
 536
 537     response = qobject_to_json(QOBJECT(rsp));
 538     if (!response) {
 539         return -EINVAL;
 540     }
 541
 542     if (s->delimit_response) {
 543         s->delimit_response = false;
 544         g_string_prepend_c(response, QGA_SENTINEL_BYTE);
 545     }
 546
 547     g_string_append_c(response, '\n');
 548     status = ga_channel_write_all(s->channel, response->str, response->len);
 549     g_string_free(response, true);
 550     if (status != G_IO_STATUS_NORMAL) {
 551         return -EIO;
 552     }
 553
 554     return 0;
 555 }
 556
 557 /* handle requests/control events coming in over the channel */
 558 static void process_event(void *opaque, QObject *obj, Error *err)
 559 {
 560     GAState *s = opaque;
 561     QDict *rsp;
 562     int ret;
 563
 564     g_debug("process_event: called");
 565     assert(!obj != !err);
 566     if (err) {
 567         rsp = qmp_error_response(err);
 568         goto end;
 569     }
 570
 571     g_debug("processing command");
 572     rsp = qmp_dispatch(&ga_commands, obj, false, NULL);
 573
 574 end:
 575     ret = send_response(s, rsp);
 576     if (ret < 0) {
 577         g_warning("error sending error response: %s", strerror(-ret));
 578     }
 579     qobject_unref(rsp);
 580     qobject_unref(obj);
 581 }
 582
 583 /* false return signals GAChannel to close the current client connection */
 584 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 585 {
 586     GAState *s = data;
 587     gchar buf[QGA_READ_COUNT_DEFAULT + 1];
 588     gsize count;
 589     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 590     switch (status) {
 591     case G_IO_STATUS_ERROR:
 592         g_warning("error reading channel");
 593         stop_agent(s, false);
 594         return false;
 595     case G_IO_STATUS_NORMAL:
 596         buf[count] = 0;
 597         g_debug("read data, count: %d, data: %s", (int)count, buf);
 598         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 599         break;
 600     case G_IO_STATUS_EOF:
 601         g_debug("received EOF");
 602         if (!s->virtio) {
 603             return false;
 604         }
 605         /* fall through */
 606     case G_IO_STATUS_AGAIN:
 607         /* virtio causes us to spin here when no process is attached to
 608          * host-side chardev. sleep a bit to mitigate this
 609          */
 610         if (s->virtio) {
 611             g_usleep(G_USEC_PER_SEC / 10);
 612         }
 613         return true;
 614     default:
 615         g_warning("unknown channel read status, closing");
 616         return false;
 617     }
 618     return true;
 619 }
 620
 621 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path,
 622                              int listen_fd)
 623 {
 624     GAChannelMethod channel_method;
 625
 626     if (strcmp(method, "virtio-serial") == 0) {
 627         s->virtio = true; /* virtio requires special handling in some cases */
 628         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 629     } else if (strcmp(method, "isa-serial") == 0) {
 630         channel_method = GA_CHANNEL_ISA_SERIAL;
 631     } else if (strcmp(method, "unix-listen") == 0) {
 632         channel_method = GA_CHANNEL_UNIX_LISTEN;
 633     } else if (strcmp(method, "vsock-listen") == 0) {
 634         channel_method = GA_CHANNEL_VSOCK_LISTEN;
 635     } else {
 636         g_critical("unsupported channel method/type: %s", method);
 637         return false;
 638     }
 639
 640     s->channel = ga_channel_new(channel_method, path, listen_fd,
 641                                 channel_event_cb, s);
 642     if (!s->channel) {
 643         g_critical("failed to create guest agent channel");
 644         return false;
 645     }
 646
 647     return true;
 648 }
 649
 650 #ifdef _WIN32
 651 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data)
 652 {
 653     DWORD ret = NO_ERROR;
 654     PDEV_BROADCAST_HDR broadcast_header = (PDEV_BROADCAST_HDR)data;
 655
 656     if (broadcast_header->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE) {
 657         switch (type) {
 658             /* Device inserted */
 659         case DBT_DEVICEARRIVAL:
 660             /* Start QEMU-ga's service */
 661             if (!SetEvent(ga_state->wakeup_event)) {
 662                 ret = GetLastError();
 663             }
 664             break;
 665             /* Device removed */
 666         case DBT_DEVICEQUERYREMOVE:
 667         case DBT_DEVICEREMOVEPENDING:
 668         case DBT_DEVICEREMOVECOMPLETE:
 669             /* Stop QEMU-ga's service */
 670             if (!ResetEvent(ga_state->wakeup_event)) {
 671                 ret = GetLastError();
 672             }
 673             break;
 674         default:
 675             ret = ERROR_CALL_NOT_IMPLEMENTED;
 676         }
 677     }
 678     return ret;
 679 }
 680
 681 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 682                                   LPVOID ctx)
 683 {
 684     DWORD ret = NO_ERROR;
 685     GAService *service = &ga_state->service;
 686
 687     switch (ctrl) {
 688     case SERVICE_CONTROL_STOP:
 689     case SERVICE_CONTROL_SHUTDOWN:
 690         quit_handler(SIGTERM);
 691         SetEvent(ga_state->wakeup_event);
 692         service->status.dwCurrentState = SERVICE_STOP_PENDING;
 693         SetServiceStatus(service->status_handle, &service->status);
 694         break;
 695     case SERVICE_CONTROL_DEVICEEVENT:
 696         handle_serial_device_events(type, data);
 697         break;
 698
 699     default:
 700         ret = ERROR_CALL_NOT_IMPLEMENTED;
 701     }
 702     return ret;
 703 }
 704
 705 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 706 {
 707     GAService *service = &ga_state->service;
 708
 709     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 710         service_ctrl_handler, NULL);
 711
 712     if (service->status_handle == 0) {
 713         g_critical("Failed to register extended requests function!\n");
 714         return;
 715     }
 716
 717     service->status.dwServiceType = SERVICE_WIN32;
 718     service->status.dwCurrentState = SERVICE_RUNNING;
 719     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 720     service->status.dwWin32ExitCode = NO_ERROR;
 721     service->status.dwServiceSpecificExitCode = NO_ERROR;
 722     service->status.dwCheckPoint = 0;
 723     service->status.dwWaitHint = 0;
 724     DEV_BROADCAST_DEVICEINTERFACE notification_filter;
 725     ZeroMemory(&notification_filter, sizeof(notification_filter));
 726     notification_filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
 727     notification_filter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
 728     notification_filter.dbcc_classguid = GUID_VIOSERIAL_PORT;
 729
 730     service->device_notification_handle =
 731         RegisterDeviceNotification(service->status_handle,
 732             &notification_filter, DEVICE_NOTIFY_SERVICE_HANDLE);
 733     if (!service->device_notification_handle) {
 734         g_critical("Failed to register device notification handle!\n");
 735         return;
 736     }
 737     SetServiceStatus(service->status_handle, &service->status);
 738
 739     run_agent(ga_state);
 740
 741     UnregisterDeviceNotification(service->device_notification_handle);
 742     service->status.dwCurrentState = SERVICE_STOPPED;
 743     SetServiceStatus(service->status_handle, &service->status);
 744 }
 745 #endif
 746
 747 static void set_persistent_state_defaults(GAPersistentState *pstate)
 748 {
 749     g_assert(pstate);
 750     pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
 751 }
 752
 753 static void persistent_state_from_keyfile(GAPersistentState *pstate,
 754                                           GKeyFile *keyfile)
 755 {
 756     g_assert(pstate);
 757     g_assert(keyfile);
 758     /* if any fields are missing, either because the file was tampered with
 759      * by agents of chaos, or because the field wasn't present at the time the
 760      * file was created, the best we can ever do is start over with the default
 761      * values. so load them now, and ignore any errors in accessing key-value
 762      * pairs
 763      */
 764     set_persistent_state_defaults(pstate);
 765
 766     if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
 767         pstate->fd_counter =
 768             g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
 769     }
 770 }
 771
 772 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
 773                                         GKeyFile *keyfile)
 774 {
 775     g_assert(pstate);
 776     g_assert(keyfile);
 777
 778     g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
 779 }
 780
 781 static gboolean write_persistent_state(const GAPersistentState *pstate,
 782                                        const gchar *path)
 783 {
 784     GKeyFile *keyfile = g_key_file_new();
 785     GError *gerr = NULL;
 786     gboolean ret = true;
 787     gchar *data = NULL;
 788     gsize data_len;
 789
 790     g_assert(pstate);
 791
 792     persistent_state_to_keyfile(pstate, keyfile);
 793     data = g_key_file_to_data(keyfile, &data_len, &gerr);
 794     if (gerr) {
 795         g_critical("failed to convert persistent state to string: %s",
 796                    gerr->message);
 797         ret = false;
 798         goto out;
 799     }
 800
 801     g_file_set_contents(path, data, data_len, &gerr);
 802     if (gerr) {
 803         g_critical("failed to write persistent state to %s: %s",
 804                     path, gerr->message);
 805         ret = false;
 806         goto out;
 807     }
 808
 809 out:
 810     if (gerr) {
 811         g_error_free(gerr);
 812     }
 813     if (keyfile) {
 814         g_key_file_free(keyfile);
 815     }
 816     g_free(data);
 817     return ret;
 818 }
 819
 820 static gboolean read_persistent_state(GAPersistentState *pstate,
 821                                       const gchar *path, gboolean frozen)
 822 {
 823     GKeyFile *keyfile = NULL;
 824     GError *gerr = NULL;
 825     struct stat st;
 826     gboolean ret = true;
 827
 828     g_assert(pstate);
 829
 830     if (stat(path, &st) == -1) {
 831         /* it's okay if state file doesn't exist, but any other error
 832          * indicates a permissions issue or some other misconfiguration
 833          * that we likely won't be able to recover from.
 834          */
 835         if (errno != ENOENT) {
 836             g_critical("unable to access state file at path %s: %s",
 837                        path, strerror(errno));
 838             ret = false;
 839             goto out;
 840         }
 841
 842         /* file doesn't exist. initialize state to default values and
 843          * attempt to save now. (we could wait till later when we have
 844          * modified state we need to commit, but if there's a problem,
 845          * such as a missing parent directory, we want to catch it now)
 846          *
 847          * there is a potential scenario where someone either managed to
 848          * update the agent from a version that didn't use a key store
 849          * while qemu-ga thought the filesystem was frozen, or
 850          * deleted the key store prior to issuing a fsfreeze, prior
 851          * to restarting the agent. in this case we go ahead and defer
 852          * initial creation till we actually have modified state to
 853          * write, otherwise fail to recover from freeze.
 854          */
 855         set_persistent_state_defaults(pstate);
 856         if (!frozen) {
 857             ret = write_persistent_state(pstate, path);
 858             if (!ret) {
 859                 g_critical("unable to create state file at path %s", path);
 860                 ret = false;
 861                 goto out;
 862             }
 863         }
 864         ret = true;
 865         goto out;
 866     }
 867
 868     keyfile = g_key_file_new();
 869     g_key_file_load_from_file(keyfile, path, 0, &gerr);
 870     if (gerr) {
 871         g_critical("error loading persistent state from path: %s, %s",
 872                    path, gerr->message);
 873         ret = false;
 874         goto out;
 875     }
 876
 877     persistent_state_from_keyfile(pstate, keyfile);
 878
 879 out:
 880     if (keyfile) {
 881         g_key_file_free(keyfile);
 882     }
 883     if (gerr) {
 884         g_error_free(gerr);
 885     }
 886
 887     return ret;
 888 }
 889
 890 int64_t ga_get_fd_handle(GAState *s, Error **errp)
 891 {
 892     int64_t handle;
 893
 894     g_assert(s->pstate_filepath);
 895     /* we blacklist commands and avoid operations that potentially require
 896      * writing to disk when we're in a frozen state. this includes opening
 897      * new files, so we should never get here in that situation
 898      */
 899     g_assert(!ga_is_frozen(s));
 900
 901     handle = s->pstate.fd_counter++;
 902
 903     /* This should never happen on a reasonable timeframe, as guest-file-open
 904      * would have to be issued 2^63 times */
 905     if (s->pstate.fd_counter == INT64_MAX) {
 906         abort();
 907     }
 908
 909     if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
 910         error_setg(errp, "failed to commit persistent state to disk");
 911         return -1;
 912     }
 913
 914     return handle;
 915 }
 916
 917 static void ga_print_cmd(const QmpCommand *cmd, void *opaque)
 918 {
 919     printf("%s\n", qmp_command_name(cmd));
 920 }
 921
 922 static GList *split_list(const gchar *str, const gchar *delim)
 923 {
 924     GList *list = NULL;
 925     int i;
 926     gchar **strv;
 927
 928     strv = g_strsplit(str, delim, -1);
 929     for (i = 0; strv[i]; i++) {
 930         list = g_list_prepend(list, strv[i]);
 931     }
 932     g_free(strv);
 933
 934     return list;
 935 }
 936
 937 struct GAConfig {
 938     char *channel_path;
 939     char *method;
 940     char *log_filepath;
 941     char *pid_filepath;
 942 #ifdef CONFIG_FSFREEZE
 943     char *fsfreeze_hook;
 944 #endif
 945     char *state_dir;
 946 #ifdef _WIN32
 947     const char *service;
 948 #endif
 949     gchar *bliststr; /* blacklist may point to this string */
 950     GList *blacklist;
 951     int daemonize;
 952     GLogLevelFlags log_level;
 953     int dumpconf;
 954     bool retry_path;
 955 };
 956
 957 static void config_load(GAConfig *config)
 958 {
 959     GError *gerr = NULL;
 960     GKeyFile *keyfile;
 961     g_autofree char *conf = g_strdup(g_getenv("QGA_CONF")) ?: get_relocated_path(QGA_CONF_DEFAULT);
 962
 963     /* read system config */
 964     keyfile = g_key_file_new();
 965     if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
 966         goto end;
 967     }
 968     if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
 969         config->daemonize =
 970             g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
 971     }
 972     if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
 973         config->method =
 974             g_key_file_get_string(keyfile, "general", "method", &gerr);
 975     }
 976     if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
 977         config->channel_path =
 978             g_key_file_get_string(keyfile, "general", "path", &gerr);
 979     }
 980     if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
 981         config->log_filepath =
 982             g_key_file_get_string(keyfile, "general", "logfile", &gerr);
 983     }
 984     if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
 985         config->pid_filepath =
 986             g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
 987     }
 988 #ifdef CONFIG_FSFREEZE
 989     if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
 990         config->fsfreeze_hook =
 991             g_key_file_get_string(keyfile,
 992                                   "general", "fsfreeze-hook", &gerr);
 993     }
 994 #endif
 995     if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
 996         config->state_dir =
 997             g_key_file_get_string(keyfile, "general", "statedir", &gerr);
 998     }
 999     if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
1000         g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
1001         /* enable all log levels */
1002         config->log_level = G_LOG_LEVEL_MASK;
1003     }
1004     if (g_key_file_has_key(keyfile, "general", "retry-path", NULL)) {
1005         config->retry_path =
1006             g_key_file_get_boolean(keyfile, "general", "retry-path", &gerr);
1007     }
1008     if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
1009         config->bliststr =
1010             g_key_file_get_string(keyfile, "general", "blacklist", &gerr);
1011         config->blacklist = g_list_concat(config->blacklist,
1012                                           split_list(config->bliststr, ","));
1013     }
1014
1015 end:
1016     g_key_file_free(keyfile);
1017     if (gerr &&
1018         !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
1019         g_critical("error loading configuration from path: %s, %s",
1020                    conf, gerr->message);
1021         exit(EXIT_FAILURE);
1022     }
1023     g_clear_error(&gerr);
1024 }
1025
1026 static gchar *list_join(GList *list, const gchar separator)
1027 {
1028     GString *str = g_string_new("");
1029
1030     while (list) {
1031         str = g_string_append(str, (gchar *)list->data);
1032         list = g_list_next(list);
1033         if (list) {
1034             str = g_string_append_c(str, separator);
1035         }
1036     }
1037
1038     return g_string_free(str, FALSE);
1039 }
1040
1041 static void config_dump(GAConfig *config)
1042 {
1043     GError *error = NULL;
1044     GKeyFile *keyfile;
1045     gchar *tmp;
1046
1047     keyfile = g_key_file_new();
1048     g_assert(keyfile);
1049
1050     g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1051     g_key_file_set_string(keyfile, "general", "method", config->method);
1052     if (config->channel_path) {
1053         g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1054     }
1055     if (config->log_filepath) {
1056         g_key_file_set_string(keyfile, "general", "logfile",
1057                               config->log_filepath);
1058     }
1059     g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1060 #ifdef CONFIG_FSFREEZE
1061     if (config->fsfreeze_hook) {
1062         g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1063                               config->fsfreeze_hook);
1064     }
1065 #endif
1066     g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1067     g_key_file_set_boolean(keyfile, "general", "verbose",
1068                            config->log_level == G_LOG_LEVEL_MASK);
1069     g_key_file_set_boolean(keyfile, "general", "retry-path",
1070                            config->retry_path);
1071     tmp = list_join(config->blacklist, ',');
1072     g_key_file_set_string(keyfile, "general", "blacklist", tmp);
1073     g_free(tmp);
1074
1075     tmp = g_key_file_to_data(keyfile, NULL, &error);
1076     if (error) {
1077         g_critical("Failed to dump keyfile: %s", error->message);
1078         g_clear_error(&error);
1079     } else {
1080         printf("%s", tmp);
1081     }
1082
1083     g_free(tmp);
1084     g_key_file_free(keyfile);
1085 }
1086
1087 static void config_parse(GAConfig *config, int argc, char **argv)
1088 {
1089     const char *sopt = "hVvdm:p:l:f:F::b:s:t:Dr";
1090     int opt_ind = 0, ch;
1091     const struct option lopt[] = {
1092         { "help", 0, NULL, 'h' },
1093         { "version", 0, NULL, 'V' },
1094         { "dump-conf", 0, NULL, 'D' },
1095         { "logfile", 1, NULL, 'l' },
1096         { "pidfile", 1, NULL, 'f' },
1097 #ifdef CONFIG_FSFREEZE
1098         { "fsfreeze-hook", 2, NULL, 'F' },
1099 #endif
1100         { "verbose", 0, NULL, 'v' },
1101         { "method", 1, NULL, 'm' },
1102         { "path", 1, NULL, 'p' },
1103         { "daemonize", 0, NULL, 'd' },
1104         { "blacklist", 1, NULL, 'b' },
1105 #ifdef _WIN32
1106         { "service", 1, NULL, 's' },
1107 #endif
1108         { "statedir", 1, NULL, 't' },
1109         { "retry-path", 0, NULL, 'r' },
1110         { NULL, 0, NULL, 0 }
1111     };
1112
1113     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1114         switch (ch) {
1115         case 'm':
1116             g_free(config->method);
1117             config->method = g_strdup(optarg);
1118             break;
1119         case 'p':
1120             g_free(config->channel_path);
1121             config->channel_path = g_strdup(optarg);
1122             break;
1123         case 'l':
1124             g_free(config->log_filepath);
1125             config->log_filepath = g_strdup(optarg);
1126             break;
1127         case 'f':
1128             g_free(config->pid_filepath);
1129             config->pid_filepath = g_strdup(optarg);
1130             break;
1131 #ifdef CONFIG_FSFREEZE
1132         case 'F':
1133             g_free(config->fsfreeze_hook);
1134             config->fsfreeze_hook = optarg ? g_strdup(optarg) : get_relocated_path(QGA_FSFREEZE_HOOK_DEFAULT);
1135             break;
1136 #endif
1137         case 't':
1138             g_free(config->state_dir);
1139             config->state_dir = g_strdup(optarg);
1140             break;
1141         case 'v':
1142             /* enable all log levels */
1143             config->log_level = G_LOG_LEVEL_MASK;
1144             break;
1145         case 'V':
1146             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1147             exit(EXIT_SUCCESS);
1148         case 'd':
1149             config->daemonize = 1;
1150             break;
1151         case 'D':
1152             config->dumpconf = 1;
1153             break;
1154         case 'r':
1155             config->retry_path = true;
1156             break;
1157         case 'b': {
1158             if (is_help_option(optarg)) {
1159                 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1160                 exit(EXIT_SUCCESS);
1161             }
1162             config->blacklist = g_list_concat(config->blacklist,
1163                                              split_list(optarg, ","));
1164             break;
1165         }
1166 #ifdef _WIN32
1167         case 's':
1168             config->service = optarg;
1169             if (strcmp(config->service, "install") == 0) {
1170                 if (ga_install_vss_provider()) {
1171                     exit(EXIT_FAILURE);
1172                 }
1173                 if (ga_install_service(config->channel_path,
1174                                        config->log_filepath, config->state_dir)) {
1175                     exit(EXIT_FAILURE);
1176                 }
1177                 exit(EXIT_SUCCESS);
1178             } else if (strcmp(config->service, "uninstall") == 0) {
1179                 ga_uninstall_vss_provider();
1180                 exit(ga_uninstall_service());
1181             } else if (strcmp(config->service, "vss-install") == 0) {
1182                 if (ga_install_vss_provider()) {
1183                     exit(EXIT_FAILURE);
1184                 }
1185                 exit(EXIT_SUCCESS);
1186             } else if (strcmp(config->service, "vss-uninstall") == 0) {
1187                 ga_uninstall_vss_provider();
1188                 exit(EXIT_SUCCESS);
1189             } else {
1190                 printf("Unknown service command.\n");
1191                 exit(EXIT_FAILURE);
1192             }
1193             break;
1194 #endif
1195         case 'h':
1196             usage(argv[0]);
1197             exit(EXIT_SUCCESS);
1198         case '?':
1199             g_print("Unknown option, try '%s --help' for more information.\n",
1200                     argv[0]);
1201             exit(EXIT_FAILURE);
1202         }
1203     }
1204 }
1205
1206 static void config_free(GAConfig *config)
1207 {
1208     g_free(config->method);
1209     g_free(config->log_filepath);
1210     g_free(config->pid_filepath);
1211     g_free(config->state_dir);
1212     g_free(config->channel_path);
1213     g_free(config->bliststr);
1214 #ifdef CONFIG_FSFREEZE
1215     g_free(config->fsfreeze_hook);
1216 #endif
1217     g_list_free_full(config->blacklist, g_free);
1218     g_free(config);
1219 }
1220
1221 static bool check_is_frozen(GAState *s)
1222 {
1223 #ifndef _WIN32
1224     /* check if a previous instance of qemu-ga exited with filesystems' state
1225      * marked as frozen. this could be a stale value (a non-qemu-ga process
1226      * or reboot may have since unfrozen them), but better to require an
1227      * uneeded unfreeze than to risk hanging on start-up
1228      */
1229     struct stat st;
1230     if (stat(s->state_filepath_isfrozen, &st) == -1) {
1231         /* it's okay if the file doesn't exist, but if we can't access for
1232          * some other reason, such as permissions, there's a configuration
1233          * that needs to be addressed. so just bail now before we get into
1234          * more trouble later
1235          */
1236         if (errno != ENOENT) {
1237             g_critical("unable to access state file at path %s: %s",
1238                        s->state_filepath_isfrozen, strerror(errno));
1239             return EXIT_FAILURE;
1240         }
1241     } else {
1242         g_warning("previous instance appears to have exited with frozen"
1243                   " filesystems. deferring logging/pidfile creation and"
1244                   " disabling non-fsfreeze-safe commands until"
1245                   " guest-fsfreeze-thaw is issued, or filesystems are"
1246                   " manually unfrozen and the file %s is removed",
1247                   s->state_filepath_isfrozen);
1248         return true;
1249     }
1250 #endif
1251     return false;
1252 }
1253
1254 static GAState *initialize_agent(GAConfig *config, int socket_activation)
1255 {
1256     GAState *s = g_new0(GAState, 1);
1257
1258     g_assert(ga_state == NULL);
1259
1260     s->log_level = config->log_level;
1261     s->log_file = stderr;
1262 #ifdef CONFIG_FSFREEZE
1263     s->fsfreeze_hook = config->fsfreeze_hook;
1264 #endif
1265     s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1266     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1267                                                  config->state_dir);
1268     s->frozen = check_is_frozen(s);
1269
1270     g_log_set_default_handler(ga_log, s);
1271     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1272     ga_enable_logging(s);
1273
1274 #ifdef _WIN32
1275     /* On win32 the state directory is application specific (be it the default
1276      * or a user override). We got past the command line parsing; let's create
1277      * the directory (with any intermediate directories). If we run into an
1278      * error later on, we won't try to clean up the directory, it is considered
1279      * persistent.
1280      */
1281     if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1282         g_critical("unable to create (an ancestor of) the state directory"
1283                    " '%s': %s", config->state_dir, strerror(errno));
1284         return NULL;
1285     }
1286 #endif
1287
1288     if (ga_is_frozen(s)) {
1289         if (config->daemonize) {
1290             /* delay opening/locking of pidfile till filesystems are unfrozen */
1291             s->deferred_options.pid_filepath = config->pid_filepath;
1292             become_daemon(NULL);
1293         }
1294         if (config->log_filepath) {
1295             /* delay opening the log file till filesystems are unfrozen */
1296             s->deferred_options.log_filepath = config->log_filepath;
1297         }
1298         ga_disable_logging(s);
1299         qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
1300     } else {
1301         if (config->daemonize) {
1302             become_daemon(config->pid_filepath);
1303         }
1304         if (config->log_filepath) {
1305             FILE *log_file = ga_open_logfile(config->log_filepath);
1306             if (!log_file) {
1307                 g_critical("unable to open specified log file: %s",
1308                            strerror(errno));
1309                 return NULL;
1310             }
1311             s->log_file = log_file;
1312         }
1313     }
1314
1315     /* load persistent state from disk */
1316     if (!read_persistent_state(&s->pstate,
1317                                s->pstate_filepath,
1318                                ga_is_frozen(s))) {
1319         g_critical("failed to load persistent state");
1320         return NULL;
1321     }
1322
1323     config->blacklist = ga_command_blacklist_init(config->blacklist);
1324     if (config->blacklist) {
1325         GList *l = config->blacklist;
1326         s->blacklist = config->blacklist;
1327         do {
1328             g_debug("disabling command: %s", (char *)l->data);
1329             qmp_disable_command(&ga_commands, l->data, NULL);
1330             l = g_list_next(l);
1331         } while (l);
1332     }
1333     s->command_state = ga_command_state_new();
1334     ga_command_state_init(s, s->command_state);
1335     ga_command_state_init_all(s->command_state);
1336     json_message_parser_init(&s->parser, process_event, s, NULL);
1337
1338 #ifndef _WIN32
1339     if (!register_signal_handlers()) {
1340         g_critical("failed to register signal handlers");
1341         return NULL;
1342     }
1343 #endif
1344
1345     s->main_loop = g_main_loop_new(NULL, false);
1346
1347     s->config = config;
1348     s->socket_activation = socket_activation;
1349
1350 #ifdef _WIN32
1351     s->wakeup_event = CreateEvent(NULL, TRUE, FALSE, TEXT("WakeUp"));
1352     if (s->wakeup_event == NULL) {
1353         g_critical("CreateEvent failed");
1354         return NULL;
1355     }
1356 #endif
1357
1358     ga_state = s;
1359     return s;
1360 }
1361
1362 static void cleanup_agent(GAState *s)
1363 {
1364 #ifdef _WIN32
1365     CloseHandle(s->wakeup_event);
1366 #endif
1367     if (s->command_state) {
1368         ga_command_state_cleanup_all(s->command_state);
1369         ga_command_state_free(s->command_state);
1370         json_message_parser_destroy(&s->parser);
1371     }
1372     g_free(s->pstate_filepath);
1373     g_free(s->state_filepath_isfrozen);
1374     if (s->main_loop) {
1375         g_main_loop_unref(s->main_loop);
1376     }
1377     g_free(s);
1378     ga_state = NULL;
1379 }
1380
1381 static int run_agent_once(GAState *s)
1382 {
1383     if (!channel_init(s, s->config->method, s->config->channel_path,
1384                       s->socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
1385         g_critical("failed to initialize guest agent channel");
1386         return EXIT_FAILURE;
1387     }
1388
1389     g_main_loop_run(ga_state->main_loop);
1390
1391     if (s->channel) {
1392         ga_channel_free(s->channel);
1393     }
1394
1395     return EXIT_SUCCESS;
1396 }
1397
1398 static void wait_for_channel_availability(GAState *s)
1399 {
1400     g_warning("waiting for channel path...");
1401 #ifndef _WIN32
1402     sleep(QGA_RETRY_INTERVAL);
1403 #else
1404     DWORD dwWaitResult;
1405
1406     dwWaitResult = WaitForSingleObject(s->wakeup_event, INFINITE);
1407
1408     switch (dwWaitResult) {
1409     case WAIT_OBJECT_0:
1410         break;
1411     case WAIT_TIMEOUT:
1412         break;
1413     default:
1414         g_critical("WaitForSingleObject failed");
1415     }
1416 #endif
1417 }
1418
1419 static int run_agent(GAState *s)
1420 {
1421     int ret = EXIT_SUCCESS;
1422
1423     s->force_exit = false;
1424
1425     do {
1426         ret = run_agent_once(s);
1427         if (s->config->retry_path && !s->force_exit) {
1428             g_warning("agent stopped unexpectedly, restarting...");
1429             wait_for_channel_availability(s);
1430         }
1431     } while (s->config->retry_path && !s->force_exit);
1432
1433     return ret;
1434 }
1435
1436 static void stop_agent(GAState *s, bool requested)
1437 {
1438     if (!s->force_exit) {
1439         s->force_exit = requested;
1440     }
1441
1442     if (g_main_loop_is_running(s->main_loop)) {
1443         g_main_loop_quit(s->main_loop);
1444     }
1445 }
1446
1447 int main(int argc, char **argv)
1448 {
1449     int ret = EXIT_SUCCESS;
1450     GAState *s;
1451     GAConfig *config = g_new0(GAConfig, 1);
1452     int socket_activation;
1453
1454     config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1455
1456     qemu_init_exec_dir(argv[0]);
1457     qga_qmp_init_marshal(&ga_commands);
1458
1459     init_dfl_pathnames();
1460     config_load(config);
1461     config_parse(config, argc, argv);
1462
1463     if (config->pid_filepath == NULL) {
1464         config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1465     }
1466
1467     if (config->state_dir == NULL) {
1468         config->state_dir = g_strdup(dfl_pathnames.state_dir);
1469     }
1470
1471     if (config->method == NULL) {
1472         config->method = g_strdup("virtio-serial");
1473     }
1474
1475     socket_activation = check_socket_activation();
1476     if (socket_activation > 1) {
1477         g_critical("qemu-ga only supports listening on one socket");
1478         ret = EXIT_FAILURE;
1479         goto end;
1480     }
1481     if (socket_activation) {
1482         SocketAddress *addr;
1483
1484         g_free(config->method);
1485         g_free(config->channel_path);
1486         config->method = NULL;
1487         config->channel_path = NULL;
1488
1489         addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL);
1490         if (addr) {
1491             if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
1492                 config->method = g_strdup("unix-listen");
1493             } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
1494                 config->method = g_strdup("vsock-listen");
1495             }
1496
1497             qapi_free_SocketAddress(addr);
1498         }
1499
1500         if (!config->method) {
1501             g_critical("unsupported listen fd type");
1502             ret = EXIT_FAILURE;
1503             goto end;
1504         }
1505     } else if (config->channel_path == NULL) {
1506         if (strcmp(config->method, "virtio-serial") == 0) {
1507             /* try the default path for the virtio-serial port */
1508             config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1509         } else if (strcmp(config->method, "isa-serial") == 0) {
1510             /* try the default path for the serial port - COM1 */
1511             config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1512         } else {
1513             g_critical("must specify a path for this channel");
1514             ret = EXIT_FAILURE;
1515             goto end;
1516         }
1517     }
1518
1519     if (config->dumpconf) {
1520         config_dump(config);
1521         goto end;
1522     }
1523
1524     s = initialize_agent(config, socket_activation);
1525     if (!s) {
1526         g_critical("error initializing guest agent");
1527         goto end;
1528     }
1529
1530 #ifdef _WIN32
1531     if (config->daemonize) {
1532         SERVICE_TABLE_ENTRY service_table[] = {
1533             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1534         StartServiceCtrlDispatcher(service_table);
1535     } else {
1536         ret = run_agent(s);
1537     }
1538 #else
1539     ret = run_agent(s);
1540 #endif
1541
1542     cleanup_agent(s);
1543
1544 end:
1545     if (config->daemonize) {
1546         unlink(config->pid_filepath);
1547     }
1548
1549     config_free(config);
1550
1551     return ret;
1552 }