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 "  -l, --logfile     set logfile path, logs to stderr by default\n"
 239 "  -f, --pidfile     specify pidfile (default is %s)\n"
 240 #ifdef CONFIG_FSFREEZE
 241 "  -F, --fsfreeze-hook\n"
 242 "                    enable fsfreeze hook. Accepts an optional argument that\n"
 243 "                    specifies script to run on freeze/thaw. Script will be\n"
 244 "                    called with 'freeze'/'thaw' arguments accordingly.\n"
 245 "                    (default is %s)\n"
 246 "                    If using -F with an argument, do not follow -F with a\n"
 247 "                    space.\n"
 248 "                    (for example: -F/var/run/fsfreezehook.sh)\n"
 249 #endif
 250 "  -t, --statedir    specify dir to store state information (absolute paths\n"
 251 "                    only, default is %s)\n"
 252 "  -v, --verbose     log extra debugging information\n"
 253 "  -V, --version     print version information and exit\n"
 254 "  -d, --daemonize   become a daemon\n"
 255 #ifdef _WIN32
 256 "  -s, --service     service commands: install, uninstall, vss-install, vss-uninstall\n"
 257 #endif
 258 "  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\"\n"
 259 "                    to list available RPCs)\n"
 260 "  -D, --dump-conf   dump a qemu-ga config file based on current config\n"
 261 "                    options / command-line parameters to stdout\n"
 262 "  -r, --retry-path  attempt re-opening path if it's unavailable or closed\n"
 263 "                    due to an error which may be recoverable in the future\n"
 264 "                    (virtio-serial driver re-install, serial device hot\n"
 265 "                    plug/unplug, etc.)\n"
 266 "  -h, --help        display this help and exit\n"
 267 "\n"
 268 QEMU_HELP_BOTTOM "\n"
 269     , cmd, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT,
 270     dfl_pathnames.pidfile,
 271 #ifdef CONFIG_FSFREEZE
 272     QGA_FSFREEZE_HOOK_DEFAULT,
 273 #endif
 274     dfl_pathnames.state_dir);
 275 }
 276
 277 static const char *ga_log_level_str(GLogLevelFlags level)
 278 {
 279     switch (level & G_LOG_LEVEL_MASK) {
 280         case G_LOG_LEVEL_ERROR:
 281             return "error";
 282         case G_LOG_LEVEL_CRITICAL:
 283             return "critical";
 284         case G_LOG_LEVEL_WARNING:
 285             return "warning";
 286         case G_LOG_LEVEL_MESSAGE:
 287             return "message";
 288         case G_LOG_LEVEL_INFO:
 289             return "info";
 290         case G_LOG_LEVEL_DEBUG:
 291             return "debug";
 292         default:
 293             return "user";
 294     }
 295 }
 296
 297 bool ga_logging_enabled(GAState *s)
 298 {
 299     return s->logging_enabled;
 300 }
 301
 302 void ga_disable_logging(GAState *s)
 303 {
 304     s->logging_enabled = false;
 305 }
 306
 307 void ga_enable_logging(GAState *s)
 308 {
 309     s->logging_enabled = true;
 310 }
 311
 312 static void ga_log(const gchar *domain, GLogLevelFlags level,
 313                    const gchar *msg, gpointer opaque)
 314 {
 315     GAState *s = opaque;
 316     GTimeVal time;
 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_get_current_time(&time);
 332         fprintf(s->log_file,
 333                 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, 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);
 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     const char *buf;
 529     QString *payload_qstr, *response_qstr;
 530     GIOStatus status;
 531
 532     g_assert(rsp && s->channel);
 533
 534     payload_qstr = qobject_to_json(QOBJECT(rsp));
 535     if (!payload_qstr) {
 536         return -EINVAL;
 537     }
 538
 539     if (s->delimit_response) {
 540         s->delimit_response = false;
 541         response_qstr = qstring_new();
 542         qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
 543         qstring_append(response_qstr, qstring_get_str(payload_qstr));
 544         qobject_unref(payload_qstr);
 545     } else {
 546         response_qstr = payload_qstr;
 547     }
 548
 549     qstring_append_chr(response_qstr, '\n');
 550     buf = qstring_get_str(response_qstr);
 551     status = ga_channel_write_all(s->channel, buf, strlen(buf));
 552     qobject_unref(response_qstr);
 553     if (status != G_IO_STATUS_NORMAL) {
 554         return -EIO;
 555     }
 556
 557     return 0;
 558 }
 559
 560 /* handle requests/control events coming in over the channel */
 561 static void process_event(void *opaque, QObject *obj, Error *err)
 562 {
 563     GAState *s = opaque;
 564     QDict *rsp;
 565     int ret;
 566
 567     g_debug("process_event: called");
 568     assert(!obj != !err);
 569     if (err) {
 570         rsp = qmp_error_response(err);
 571         goto end;
 572     }
 573
 574     g_debug("processing command");
 575     rsp = qmp_dispatch(&ga_commands, obj, false);
 576
 577 end:
 578     ret = send_response(s, rsp);
 579     if (ret < 0) {
 580         g_warning("error sending error response: %s", strerror(-ret));
 581     }
 582     qobject_unref(rsp);
 583     qobject_unref(obj);
 584 }
 585
 586 /* false return signals GAChannel to close the current client connection */
 587 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 588 {
 589     GAState *s = data;
 590     gchar buf[QGA_READ_COUNT_DEFAULT+1];
 591     gsize count;
 592     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 593     switch (status) {
 594     case G_IO_STATUS_ERROR:
 595         g_warning("error reading channel");
 596         stop_agent(s, false);
 597         return false;
 598     case G_IO_STATUS_NORMAL:
 599         buf[count] = 0;
 600         g_debug("read data, count: %d, data: %s", (int)count, buf);
 601         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 602         break;
 603     case G_IO_STATUS_EOF:
 604         g_debug("received EOF");
 605         if (!s->virtio) {
 606             return false;
 607         }
 608         /* fall through */
 609     case G_IO_STATUS_AGAIN:
 610         /* virtio causes us to spin here when no process is attached to
 611          * host-side chardev. sleep a bit to mitigate this
 612          */
 613         if (s->virtio) {
 614             usleep(100*1000);
 615         }
 616         return true;
 617     default:
 618         g_warning("unknown channel read status, closing");
 619         return false;
 620     }
 621     return true;
 622 }
 623
 624 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path,
 625                              int listen_fd)
 626 {
 627     GAChannelMethod channel_method;
 628
 629     if (strcmp(method, "virtio-serial") == 0) {
 630         s->virtio = true; /* virtio requires special handling in some cases */
 631         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 632     } else if (strcmp(method, "isa-serial") == 0) {
 633         channel_method = GA_CHANNEL_ISA_SERIAL;
 634     } else if (strcmp(method, "unix-listen") == 0) {
 635         channel_method = GA_CHANNEL_UNIX_LISTEN;
 636     } else if (strcmp(method, "vsock-listen") == 0) {
 637         channel_method = GA_CHANNEL_VSOCK_LISTEN;
 638     } else {
 639         g_critical("unsupported channel method/type: %s", method);
 640         return false;
 641     }
 642
 643     s->channel = ga_channel_new(channel_method, path, listen_fd,
 644                                 channel_event_cb, s);
 645     if (!s->channel) {
 646         g_critical("failed to create guest agent channel");
 647         return false;
 648     }
 649
 650     return true;
 651 }
 652
 653 #ifdef _WIN32
 654 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data)
 655 {
 656     DWORD ret = NO_ERROR;
 657     PDEV_BROADCAST_HDR broadcast_header = (PDEV_BROADCAST_HDR)data;
 658
 659     if (broadcast_header->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE) {
 660         switch (type) {
 661             /* Device inserted */
 662         case DBT_DEVICEARRIVAL:
 663             /* Start QEMU-ga's service */
 664             if (!SetEvent(ga_state->wakeup_event)) {
 665                 ret = GetLastError();
 666             }
 667             break;
 668             /* Device removed */
 669         case DBT_DEVICEQUERYREMOVE:
 670         case DBT_DEVICEREMOVEPENDING:
 671         case DBT_DEVICEREMOVECOMPLETE:
 672             /* Stop QEMU-ga's service */
 673             if (!ResetEvent(ga_state->wakeup_event)) {
 674                 ret = GetLastError();
 675             }
 676             break;
 677         default:
 678             ret = ERROR_CALL_NOT_IMPLEMENTED;
 679         }
 680     }
 681     return ret;
 682 }
 683
 684 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 685                                   LPVOID ctx)
 686 {
 687     DWORD ret = NO_ERROR;
 688     GAService *service = &ga_state->service;
 689
 690     switch (ctrl)
 691     {
 692         case SERVICE_CONTROL_STOP:
 693         case SERVICE_CONTROL_SHUTDOWN:
 694             quit_handler(SIGTERM);
 695             SetEvent(ga_state->wakeup_event);
 696             service->status.dwCurrentState = SERVICE_STOP_PENDING;
 697             SetServiceStatus(service->status_handle, &service->status);
 698             break;
 699         case SERVICE_CONTROL_DEVICEEVENT:
 700             handle_serial_device_events(type, data);
 701             break;
 702
 703         default:
 704             ret = ERROR_CALL_NOT_IMPLEMENTED;
 705     }
 706     return ret;
 707 }
 708
 709 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 710 {
 711     GAService *service = &ga_state->service;
 712
 713     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 714         service_ctrl_handler, NULL);
 715
 716     if (service->status_handle == 0) {
 717         g_critical("Failed to register extended requests function!\n");
 718         return;
 719     }
 720
 721     service->status.dwServiceType = SERVICE_WIN32;
 722     service->status.dwCurrentState = SERVICE_RUNNING;
 723     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 724     service->status.dwWin32ExitCode = NO_ERROR;
 725     service->status.dwServiceSpecificExitCode = NO_ERROR;
 726     service->status.dwCheckPoint = 0;
 727     service->status.dwWaitHint = 0;
 728     DEV_BROADCAST_DEVICEINTERFACE notification_filter;
 729     ZeroMemory(&notification_filter, sizeof(notification_filter));
 730     notification_filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
 731     notification_filter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
 732     notification_filter.dbcc_classguid = GUID_VIOSERIAL_PORT;
 733
 734     service->device_notification_handle =
 735         RegisterDeviceNotification(service->status_handle,
 736             &notification_filter, DEVICE_NOTIFY_SERVICE_HANDLE);
 737     if (!service->device_notification_handle) {
 738         g_critical("Failed to register device notification handle!\n");
 739         return;
 740     }
 741     SetServiceStatus(service->status_handle, &service->status);
 742
 743     run_agent(ga_state);
 744
 745     UnregisterDeviceNotification(service->device_notification_handle);
 746     service->status.dwCurrentState = SERVICE_STOPPED;
 747     SetServiceStatus(service->status_handle, &service->status);
 748 }
 749 #endif
 750
 751 static void set_persistent_state_defaults(GAPersistentState *pstate)
 752 {
 753     g_assert(pstate);
 754     pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
 755 }
 756
 757 static void persistent_state_from_keyfile(GAPersistentState *pstate,
 758                                           GKeyFile *keyfile)
 759 {
 760     g_assert(pstate);
 761     g_assert(keyfile);
 762     /* if any fields are missing, either because the file was tampered with
 763      * by agents of chaos, or because the field wasn't present at the time the
 764      * file was created, the best we can ever do is start over with the default
 765      * values. so load them now, and ignore any errors in accessing key-value
 766      * pairs
 767      */
 768     set_persistent_state_defaults(pstate);
 769
 770     if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
 771         pstate->fd_counter =
 772             g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
 773     }
 774 }
 775
 776 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
 777                                         GKeyFile *keyfile)
 778 {
 779     g_assert(pstate);
 780     g_assert(keyfile);
 781
 782     g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
 783 }
 784
 785 static gboolean write_persistent_state(const GAPersistentState *pstate,
 786                                        const gchar *path)
 787 {
 788     GKeyFile *keyfile = g_key_file_new();
 789     GError *gerr = NULL;
 790     gboolean ret = true;
 791     gchar *data = NULL;
 792     gsize data_len;
 793
 794     g_assert(pstate);
 795
 796     persistent_state_to_keyfile(pstate, keyfile);
 797     data = g_key_file_to_data(keyfile, &data_len, &gerr);
 798     if (gerr) {
 799         g_critical("failed to convert persistent state to string: %s",
 800                    gerr->message);
 801         ret = false;
 802         goto out;
 803     }
 804
 805     g_file_set_contents(path, data, data_len, &gerr);
 806     if (gerr) {
 807         g_critical("failed to write persistent state to %s: %s",
 808                     path, gerr->message);
 809         ret = false;
 810         goto out;
 811     }
 812
 813 out:
 814     if (gerr) {
 815         g_error_free(gerr);
 816     }
 817     if (keyfile) {
 818         g_key_file_free(keyfile);
 819     }
 820     g_free(data);
 821     return ret;
 822 }
 823
 824 static gboolean read_persistent_state(GAPersistentState *pstate,
 825                                       const gchar *path, gboolean frozen)
 826 {
 827     GKeyFile *keyfile = NULL;
 828     GError *gerr = NULL;
 829     struct stat st;
 830     gboolean ret = true;
 831
 832     g_assert(pstate);
 833
 834     if (stat(path, &st) == -1) {
 835         /* it's okay if state file doesn't exist, but any other error
 836          * indicates a permissions issue or some other misconfiguration
 837          * that we likely won't be able to recover from.
 838          */
 839         if (errno != ENOENT) {
 840             g_critical("unable to access state file at path %s: %s",
 841                        path, strerror(errno));
 842             ret = false;
 843             goto out;
 844         }
 845
 846         /* file doesn't exist. initialize state to default values and
 847          * attempt to save now. (we could wait till later when we have
 848          * modified state we need to commit, but if there's a problem,
 849          * such as a missing parent directory, we want to catch it now)
 850          *
 851          * there is a potential scenario where someone either managed to
 852          * update the agent from a version that didn't use a key store
 853          * while qemu-ga thought the filesystem was frozen, or
 854          * deleted the key store prior to issuing a fsfreeze, prior
 855          * to restarting the agent. in this case we go ahead and defer
 856          * initial creation till we actually have modified state to
 857          * write, otherwise fail to recover from freeze.
 858          */
 859         set_persistent_state_defaults(pstate);
 860         if (!frozen) {
 861             ret = write_persistent_state(pstate, path);
 862             if (!ret) {
 863                 g_critical("unable to create state file at path %s", path);
 864                 ret = false;
 865                 goto out;
 866             }
 867         }
 868         ret = true;
 869         goto out;
 870     }
 871
 872     keyfile = g_key_file_new();
 873     g_key_file_load_from_file(keyfile, path, 0, &gerr);
 874     if (gerr) {
 875         g_critical("error loading persistent state from path: %s, %s",
 876                    path, gerr->message);
 877         ret = false;
 878         goto out;
 879     }
 880
 881     persistent_state_from_keyfile(pstate, keyfile);
 882
 883 out:
 884     if (keyfile) {
 885         g_key_file_free(keyfile);
 886     }
 887     if (gerr) {
 888         g_error_free(gerr);
 889     }
 890
 891     return ret;
 892 }
 893
 894 int64_t ga_get_fd_handle(GAState *s, Error **errp)
 895 {
 896     int64_t handle;
 897
 898     g_assert(s->pstate_filepath);
 899     /* we blacklist commands and avoid operations that potentially require
 900      * writing to disk when we're in a frozen state. this includes opening
 901      * new files, so we should never get here in that situation
 902      */
 903     g_assert(!ga_is_frozen(s));
 904
 905     handle = s->pstate.fd_counter++;
 906
 907     /* This should never happen on a reasonable timeframe, as guest-file-open
 908      * would have to be issued 2^63 times */
 909     if (s->pstate.fd_counter == INT64_MAX) {
 910         abort();
 911     }
 912
 913     if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
 914         error_setg(errp, "failed to commit persistent state to disk");
 915         return -1;
 916     }
 917
 918     return handle;
 919 }
 920
 921 static void ga_print_cmd(const QmpCommand *cmd, void *opaque)
 922 {
 923     printf("%s\n", qmp_command_name(cmd));
 924 }
 925
 926 static GList *split_list(const gchar *str, const gchar *delim)
 927 {
 928     GList *list = NULL;
 929     int i;
 930     gchar **strv;
 931
 932     strv = g_strsplit(str, delim, -1);
 933     for (i = 0; strv[i]; i++) {
 934         list = g_list_prepend(list, strv[i]);
 935     }
 936     g_free(strv);
 937
 938     return list;
 939 }
 940
 941 struct GAConfig {
 942     char *channel_path;
 943     char *method;
 944     char *log_filepath;
 945     char *pid_filepath;
 946 #ifdef CONFIG_FSFREEZE
 947     char *fsfreeze_hook;
 948 #endif
 949     char *state_dir;
 950 #ifdef _WIN32
 951     const char *service;
 952 #endif
 953     gchar *bliststr; /* blacklist may point to this string */
 954     GList *blacklist;
 955     int daemonize;
 956     GLogLevelFlags log_level;
 957     int dumpconf;
 958     bool retry_path;
 959 };
 960
 961 static void config_load(GAConfig *config)
 962 {
 963     GError *gerr = NULL;
 964     GKeyFile *keyfile;
 965     const char *conf = g_getenv("QGA_CONF") ?: QGA_CONF_DEFAULT;
 966
 967     /* read system config */
 968     keyfile = g_key_file_new();
 969     if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
 970         goto end;
 971     }
 972     if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
 973         config->daemonize =
 974             g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
 975     }
 976     if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
 977         config->method =
 978             g_key_file_get_string(keyfile, "general", "method", &gerr);
 979     }
 980     if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
 981         config->channel_path =
 982             g_key_file_get_string(keyfile, "general", "path", &gerr);
 983     }
 984     if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
 985         config->log_filepath =
 986             g_key_file_get_string(keyfile, "general", "logfile", &gerr);
 987     }
 988     if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
 989         config->pid_filepath =
 990             g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
 991     }
 992 #ifdef CONFIG_FSFREEZE
 993     if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
 994         config->fsfreeze_hook =
 995             g_key_file_get_string(keyfile,
 996                                   "general", "fsfreeze-hook", &gerr);
 997     }
 998 #endif
 999     if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
1000         config->state_dir =
1001             g_key_file_get_string(keyfile, "general", "statedir", &gerr);
1002     }
1003     if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
1004         g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
1005         /* enable all log levels */
1006         config->log_level = G_LOG_LEVEL_MASK;
1007     }
1008     if (g_key_file_has_key(keyfile, "general", "retry-path", NULL)) {
1009         config->retry_path =
1010             g_key_file_get_boolean(keyfile, "general", "retry-path", &gerr);
1011     }
1012     if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
1013         config->bliststr =
1014             g_key_file_get_string(keyfile, "general", "blacklist", &gerr);
1015         config->blacklist = g_list_concat(config->blacklist,
1016                                           split_list(config->bliststr, ","));
1017     }
1018
1019 end:
1020     g_key_file_free(keyfile);
1021     if (gerr &&
1022         !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
1023         g_critical("error loading configuration from path: %s, %s",
1024                    QGA_CONF_DEFAULT, gerr->message);
1025         exit(EXIT_FAILURE);
1026     }
1027     g_clear_error(&gerr);
1028 }
1029
1030 static gchar *list_join(GList *list, const gchar separator)
1031 {
1032     GString *str = g_string_new("");
1033
1034     while (list) {
1035         str = g_string_append(str, (gchar *)list->data);
1036         list = g_list_next(list);
1037         if (list) {
1038             str = g_string_append_c(str, separator);
1039         }
1040     }
1041
1042     return g_string_free(str, FALSE);
1043 }
1044
1045 static void config_dump(GAConfig *config)
1046 {
1047     GError *error = NULL;
1048     GKeyFile *keyfile;
1049     gchar *tmp;
1050
1051     keyfile = g_key_file_new();
1052     g_assert(keyfile);
1053
1054     g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1055     g_key_file_set_string(keyfile, "general", "method", config->method);
1056     if (config->channel_path) {
1057         g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1058     }
1059     if (config->log_filepath) {
1060         g_key_file_set_string(keyfile, "general", "logfile",
1061                               config->log_filepath);
1062     }
1063     g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1064 #ifdef CONFIG_FSFREEZE
1065     if (config->fsfreeze_hook) {
1066         g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1067                               config->fsfreeze_hook);
1068     }
1069 #endif
1070     g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1071     g_key_file_set_boolean(keyfile, "general", "verbose",
1072                            config->log_level == G_LOG_LEVEL_MASK);
1073     g_key_file_set_boolean(keyfile, "general", "retry-path",
1074                            config->retry_path);
1075     tmp = list_join(config->blacklist, ',');
1076     g_key_file_set_string(keyfile, "general", "blacklist", tmp);
1077     g_free(tmp);
1078
1079     tmp = g_key_file_to_data(keyfile, NULL, &error);
1080     if (error) {
1081         g_critical("Failed to dump keyfile: %s", error->message);
1082         g_clear_error(&error);
1083     } else {
1084         printf("%s", tmp);
1085     }
1086
1087     g_free(tmp);
1088     g_key_file_free(keyfile);
1089 }
1090
1091 static void config_parse(GAConfig *config, int argc, char **argv)
1092 {
1093     const char *sopt = "hVvdm:p:l:f:F::b:s:t:Dr";
1094     int opt_ind = 0, ch;
1095     const struct option lopt[] = {
1096         { "help", 0, NULL, 'h' },
1097         { "version", 0, NULL, 'V' },
1098         { "dump-conf", 0, NULL, 'D' },
1099         { "logfile", 1, NULL, 'l' },
1100         { "pidfile", 1, NULL, 'f' },
1101 #ifdef CONFIG_FSFREEZE
1102         { "fsfreeze-hook", 2, NULL, 'F' },
1103 #endif
1104         { "verbose", 0, NULL, 'v' },
1105         { "method", 1, NULL, 'm' },
1106         { "path", 1, NULL, 'p' },
1107         { "daemonize", 0, NULL, 'd' },
1108         { "blacklist", 1, NULL, 'b' },
1109 #ifdef _WIN32
1110         { "service", 1, NULL, 's' },
1111 #endif
1112         { "statedir", 1, NULL, 't' },
1113         { "retry-path", 0, NULL, 'r' },
1114         { NULL, 0, NULL, 0 }
1115     };
1116
1117     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1118         switch (ch) {
1119         case 'm':
1120             g_free(config->method);
1121             config->method = g_strdup(optarg);
1122             break;
1123         case 'p':
1124             g_free(config->channel_path);
1125             config->channel_path = g_strdup(optarg);
1126             break;
1127         case 'l':
1128             g_free(config->log_filepath);
1129             config->log_filepath = g_strdup(optarg);
1130             break;
1131         case 'f':
1132             g_free(config->pid_filepath);
1133             config->pid_filepath = g_strdup(optarg);
1134             break;
1135 #ifdef CONFIG_FSFREEZE
1136         case 'F':
1137             g_free(config->fsfreeze_hook);
1138             config->fsfreeze_hook = g_strdup(optarg ?: QGA_FSFREEZE_HOOK_DEFAULT);
1139             break;
1140 #endif
1141         case 't':
1142             g_free(config->state_dir);
1143             config->state_dir = g_strdup(optarg);
1144             break;
1145         case 'v':
1146             /* enable all log levels */
1147             config->log_level = G_LOG_LEVEL_MASK;
1148             break;
1149         case 'V':
1150             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1151             exit(EXIT_SUCCESS);
1152         case 'd':
1153             config->daemonize = 1;
1154             break;
1155         case 'D':
1156             config->dumpconf = 1;
1157             break;
1158         case 'r':
1159             config->retry_path = true;
1160             break;
1161         case 'b': {
1162             if (is_help_option(optarg)) {
1163                 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1164                 exit(EXIT_SUCCESS);
1165             }
1166             config->blacklist = g_list_concat(config->blacklist,
1167                                              split_list(optarg, ","));
1168             break;
1169         }
1170 #ifdef _WIN32
1171         case 's':
1172             config->service = optarg;
1173             if (strcmp(config->service, "install") == 0) {
1174                 if (ga_install_vss_provider()) {
1175                     exit(EXIT_FAILURE);
1176                 }
1177                 if (ga_install_service(config->channel_path,
1178                                        config->log_filepath, config->state_dir)) {
1179                     exit(EXIT_FAILURE);
1180                 }
1181                 exit(EXIT_SUCCESS);
1182             } else if (strcmp(config->service, "uninstall") == 0) {
1183                 ga_uninstall_vss_provider();
1184                 exit(ga_uninstall_service());
1185             } else if (strcmp(config->service, "vss-install") == 0) {
1186                 if (ga_install_vss_provider()) {
1187                     exit(EXIT_FAILURE);
1188                 }
1189                 exit(EXIT_SUCCESS);
1190             } else if (strcmp(config->service, "vss-uninstall") == 0) {
1191                 ga_uninstall_vss_provider();
1192                 exit(EXIT_SUCCESS);
1193             } else {
1194                 printf("Unknown service command.\n");
1195                 exit(EXIT_FAILURE);
1196             }
1197             break;
1198 #endif
1199         case 'h':
1200             usage(argv[0]);
1201             exit(EXIT_SUCCESS);
1202         case '?':
1203             g_print("Unknown option, try '%s --help' for more information.\n",
1204                     argv[0]);
1205             exit(EXIT_FAILURE);
1206         }
1207     }
1208 }
1209
1210 static void config_free(GAConfig *config)
1211 {
1212     g_free(config->method);
1213     g_free(config->log_filepath);
1214     g_free(config->pid_filepath);
1215     g_free(config->state_dir);
1216     g_free(config->channel_path);
1217     g_free(config->bliststr);
1218 #ifdef CONFIG_FSFREEZE
1219     g_free(config->fsfreeze_hook);
1220 #endif
1221     g_list_free_full(config->blacklist, g_free);
1222     g_free(config);
1223 }
1224
1225 static bool check_is_frozen(GAState *s)
1226 {
1227 #ifndef _WIN32
1228     /* check if a previous instance of qemu-ga exited with filesystems' state
1229      * marked as frozen. this could be a stale value (a non-qemu-ga process
1230      * or reboot may have since unfrozen them), but better to require an
1231      * uneeded unfreeze than to risk hanging on start-up
1232      */
1233     struct stat st;
1234     if (stat(s->state_filepath_isfrozen, &st) == -1) {
1235         /* it's okay if the file doesn't exist, but if we can't access for
1236          * some other reason, such as permissions, there's a configuration
1237          * that needs to be addressed. so just bail now before we get into
1238          * more trouble later
1239          */
1240         if (errno != ENOENT) {
1241             g_critical("unable to access state file at path %s: %s",
1242                        s->state_filepath_isfrozen, strerror(errno));
1243             return EXIT_FAILURE;
1244         }
1245     } else {
1246         g_warning("previous instance appears to have exited with frozen"
1247                   " filesystems. deferring logging/pidfile creation and"
1248                   " disabling non-fsfreeze-safe commands until"
1249                   " guest-fsfreeze-thaw is issued, or filesystems are"
1250                   " manually unfrozen and the file %s is removed",
1251                   s->state_filepath_isfrozen);
1252         return true;
1253     }
1254 #endif
1255     return false;
1256 }
1257
1258 static GAState *initialize_agent(GAConfig *config, int socket_activation)
1259 {
1260     GAState *s = g_new0(GAState, 1);
1261
1262     g_assert(ga_state == NULL);
1263
1264     s->log_level = config->log_level;
1265     s->log_file = stderr;
1266 #ifdef CONFIG_FSFREEZE
1267     s->fsfreeze_hook = config->fsfreeze_hook;
1268 #endif
1269     s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1270     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1271                                                  config->state_dir);
1272     s->frozen = check_is_frozen(s);
1273
1274     g_log_set_default_handler(ga_log, s);
1275     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1276     ga_enable_logging(s);
1277
1278 #ifdef _WIN32
1279     /* On win32 the state directory is application specific (be it the default
1280      * or a user override). We got past the command line parsing; let's create
1281      * the directory (with any intermediate directories). If we run into an
1282      * error later on, we won't try to clean up the directory, it is considered
1283      * persistent.
1284      */
1285     if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1286         g_critical("unable to create (an ancestor of) the state directory"
1287                    " '%s': %s", config->state_dir, strerror(errno));
1288         return NULL;
1289     }
1290 #endif
1291
1292     if (ga_is_frozen(s)) {
1293         if (config->daemonize) {
1294             /* delay opening/locking of pidfile till filesystems are unfrozen */
1295             s->deferred_options.pid_filepath = config->pid_filepath;
1296             become_daemon(NULL);
1297         }
1298         if (config->log_filepath) {
1299             /* delay opening the log file till filesystems are unfrozen */
1300             s->deferred_options.log_filepath = config->log_filepath;
1301         }
1302         ga_disable_logging(s);
1303         qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
1304     } else {
1305         if (config->daemonize) {
1306             become_daemon(config->pid_filepath);
1307         }
1308         if (config->log_filepath) {
1309             FILE *log_file = ga_open_logfile(config->log_filepath);
1310             if (!log_file) {
1311                 g_critical("unable to open specified log file: %s",
1312                            strerror(errno));
1313                 return NULL;
1314             }
1315             s->log_file = log_file;
1316         }
1317     }
1318
1319     /* load persistent state from disk */
1320     if (!read_persistent_state(&s->pstate,
1321                                s->pstate_filepath,
1322                                ga_is_frozen(s))) {
1323         g_critical("failed to load persistent state");
1324         return NULL;
1325     }
1326
1327     config->blacklist = ga_command_blacklist_init(config->blacklist);
1328     if (config->blacklist) {
1329         GList *l = config->blacklist;
1330         s->blacklist = config->blacklist;
1331         do {
1332             g_debug("disabling command: %s", (char *)l->data);
1333             qmp_disable_command(&ga_commands, l->data);
1334             l = g_list_next(l);
1335         } while (l);
1336     }
1337     s->command_state = ga_command_state_new();
1338     ga_command_state_init(s, s->command_state);
1339     ga_command_state_init_all(s->command_state);
1340     json_message_parser_init(&s->parser, process_event, s, NULL);
1341
1342 #ifndef _WIN32
1343     if (!register_signal_handlers()) {
1344         g_critical("failed to register signal handlers");
1345         return NULL;
1346     }
1347 #endif
1348
1349     s->main_loop = g_main_loop_new(NULL, false);
1350
1351     s->config = config;
1352     s->socket_activation = socket_activation;
1353
1354 #ifdef _WIN32
1355     s->wakeup_event = CreateEvent(NULL, TRUE, FALSE, TEXT("WakeUp"));
1356     if (s->wakeup_event == NULL) {
1357         g_critical("CreateEvent failed");
1358         return NULL;
1359     }
1360 #endif
1361
1362     ga_state = s;
1363     return s;
1364 }
1365
1366 static void cleanup_agent(GAState *s)
1367 {
1368 #ifdef _WIN32
1369     CloseHandle(s->wakeup_event);
1370 #endif
1371     if (s->command_state) {
1372         ga_command_state_cleanup_all(s->command_state);
1373         ga_command_state_free(s->command_state);
1374         json_message_parser_destroy(&s->parser);
1375     }
1376     g_free(s->pstate_filepath);
1377     g_free(s->state_filepath_isfrozen);
1378     if (s->main_loop) {
1379         g_main_loop_unref(s->main_loop);
1380     }
1381     g_free(s);
1382     ga_state = NULL;
1383 }
1384
1385 static int run_agent_once(GAState *s)
1386 {
1387     if (!channel_init(s, s->config->method, s->config->channel_path,
1388                       s->socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
1389         g_critical("failed to initialize guest agent channel");
1390         return EXIT_FAILURE;
1391     }
1392
1393     g_main_loop_run(ga_state->main_loop);
1394
1395     if (s->channel) {
1396         ga_channel_free(s->channel);
1397     }
1398
1399     return EXIT_SUCCESS;
1400 }
1401
1402 static void wait_for_channel_availability(GAState *s)
1403 {
1404     g_warning("waiting for channel path...");
1405 #ifndef _WIN32
1406     sleep(QGA_RETRY_INTERVAL);
1407 #else
1408     DWORD dwWaitResult;
1409
1410     dwWaitResult = WaitForSingleObject(s->wakeup_event, INFINITE);
1411
1412     switch (dwWaitResult) {
1413     case WAIT_OBJECT_0:
1414         break;
1415     case WAIT_TIMEOUT:
1416         break;
1417     default:
1418         g_critical("WaitForSingleObject failed");
1419     }
1420 #endif
1421 }
1422
1423 static int run_agent(GAState *s)
1424 {
1425     int ret = EXIT_SUCCESS;
1426
1427     s->force_exit = false;
1428
1429     do {
1430         ret = run_agent_once(s);
1431         if (s->config->retry_path && !s->force_exit) {
1432             g_warning("agent stopped unexpectedly, restarting...");
1433             wait_for_channel_availability(s);
1434         }
1435     } while (s->config->retry_path && !s->force_exit);
1436
1437     return ret;
1438 }
1439
1440 static void stop_agent(GAState *s, bool requested)
1441 {
1442     if (!s->force_exit) {
1443         s->force_exit = requested;
1444     }
1445
1446     if (g_main_loop_is_running(s->main_loop)) {
1447         g_main_loop_quit(s->main_loop);
1448     }
1449 }
1450
1451 int main(int argc, char **argv)
1452 {
1453     int ret = EXIT_SUCCESS;
1454     GAState *s;
1455     GAConfig *config = g_new0(GAConfig, 1);
1456     int socket_activation;
1457
1458     config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1459
1460     qga_qmp_init_marshal(&ga_commands);
1461
1462     init_dfl_pathnames();
1463     config_load(config);
1464     config_parse(config, argc, argv);
1465
1466     if (config->pid_filepath == NULL) {
1467         config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1468     }
1469
1470     if (config->state_dir == NULL) {
1471         config->state_dir = g_strdup(dfl_pathnames.state_dir);
1472     }
1473
1474     if (config->method == NULL) {
1475         config->method = g_strdup("virtio-serial");
1476     }
1477
1478     socket_activation = check_socket_activation();
1479     if (socket_activation > 1) {
1480         g_critical("qemu-ga only supports listening on one socket");
1481         ret = EXIT_FAILURE;
1482         goto end;
1483     }
1484     if (socket_activation) {
1485         SocketAddress *addr;
1486
1487         g_free(config->method);
1488         g_free(config->channel_path);
1489         config->method = NULL;
1490         config->channel_path = NULL;
1491
1492         addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL);
1493         if (addr) {
1494             if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
1495                 config->method = g_strdup("unix-listen");
1496             } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
1497                 config->method = g_strdup("vsock-listen");
1498             }
1499
1500             qapi_free_SocketAddress(addr);
1501         }
1502
1503         if (!config->method) {
1504             g_critical("unsupported listen fd type");
1505             ret = EXIT_FAILURE;
1506             goto end;
1507         }
1508     } else if (config->channel_path == NULL) {
1509         if (strcmp(config->method, "virtio-serial") == 0) {
1510             /* try the default path for the virtio-serial port */
1511             config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1512         } else if (strcmp(config->method, "isa-serial") == 0) {
1513             /* try the default path for the serial port - COM1 */
1514             config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1515         } else {
1516             g_critical("must specify a path for this channel");
1517             ret = EXIT_FAILURE;
1518             goto end;
1519         }
1520     }
1521
1522     if (config->dumpconf) {
1523         config_dump(config);
1524         goto end;
1525     }
1526
1527     s = initialize_agent(config, socket_activation);
1528     if (!s) {
1529         g_critical("error initializing guest agent");
1530         goto end;
1531     }
1532
1533 #ifdef _WIN32
1534     if (config->daemonize) {
1535         SERVICE_TABLE_ENTRY service_table[] = {
1536             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1537         StartServiceCtrlDispatcher(service_table);
1538     } else {
1539         ret = run_agent(s);
1540     }
1541 #else
1542     ret = run_agent(s);
1543 #endif
1544
1545     cleanup_agent(s);
1546
1547 end:
1548     if (config->daemonize) {
1549         unlink(config->pid_filepath);
1550     }
1551
1552     config_free(config);
1553
1554     return ret;
1555 }