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/cutils.h"
  33 #include "qemu/help_option.h"
  34 #include "qemu/sockets.h"
  35 #include "qemu/systemd.h"
  36 #include "qemu-version.h"
  37 #ifdef _WIN32
  38 #include <dbt.h>
  39 #include "qga/service-win32.h"
  40 #include "qga/vss-win32.h"
  41 #endif
  42 #ifdef __linux__
  43 #include <linux/fs.h>
  44 #ifdef FIFREEZE
  45 #define CONFIG_FSFREEZE
  46 #endif
  47 #endif
  48
  49 #ifndef _WIN32
  50 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
  51 #define QGA_STATE_RELATIVE_DIR  "run"
  52 #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
  53 #else
  54 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
  55 #define QGA_STATE_RELATIVE_DIR  "qemu-ga"
  56 #define QGA_SERIAL_PATH_DEFAULT "COM1"
  57 #endif
  58 #ifdef CONFIG_FSFREEZE
  59 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
  60 #endif
  61 #define QGA_SENTINEL_BYTE 0xFF
  62 #define QGA_CONF_DEFAULT CONFIG_QEMU_CONFDIR G_DIR_SEPARATOR_S "qemu-ga.conf"
  63 #define QGA_RETRY_INTERVAL 5
  64
  65 static struct {
  66     const char *state_dir;
  67     const char *pidfile;
  68 } dfl_pathnames;
  69
  70 typedef struct GAPersistentState {
  71 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
  72     int64_t fd_counter;
  73 } GAPersistentState;
  74
  75 typedef struct GAConfig GAConfig;
  76
  77 struct GAState {
  78     JSONMessageParser parser;
  79     GMainLoop *main_loop;
  80     GAChannel *channel;
  81     bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
  82     GACommandState *command_state;
  83     GLogLevelFlags log_level;
  84     FILE *log_file;
  85     bool logging_enabled;
  86 #ifdef _WIN32
  87     GAService service;
  88     HANDLE wakeup_event;
  89 #endif
  90     bool delimit_response;
  91     bool frozen;
  92     GList *blacklist;
  93     char *state_filepath_isfrozen;
  94     struct {
  95         const char *log_filepath;
  96         const char *pid_filepath;
  97     } deferred_options;
  98 #ifdef CONFIG_FSFREEZE
  99     const char *fsfreeze_hook;
 100 #endif
 101     gchar *pstate_filepath;
 102     GAPersistentState pstate;
 103     GAConfig *config;
 104     int socket_activation;
 105     bool force_exit;
 106 };
 107
 108 struct GAState *ga_state;
 109 QmpCommandList ga_commands;
 110
 111 /* commands that are safe to issue while filesystems are frozen */
 112 static const char *ga_freeze_whitelist[] = {
 113     "guest-ping",
 114     "guest-info",
 115     "guest-sync",
 116     "guest-sync-delimited",
 117     "guest-fsfreeze-status",
 118     "guest-fsfreeze-thaw",
 119     NULL
 120 };
 121
 122 #ifdef _WIN32
 123 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 124                                   LPVOID ctx);
 125 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data);
 126 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
 127 #endif
 128 static int run_agent(GAState *s);
 129 static void stop_agent(GAState *s, bool requested);
 130
 131 static void
 132 init_dfl_pathnames(void)
 133 {
 134     g_assert(dfl_pathnames.state_dir == NULL);
 135     g_assert(dfl_pathnames.pidfile == NULL);
 136     dfl_pathnames.state_dir = qemu_get_local_state_pathname(
 137       QGA_STATE_RELATIVE_DIR);
 138     dfl_pathnames.pidfile   = qemu_get_local_state_pathname(
 139       QGA_STATE_RELATIVE_DIR G_DIR_SEPARATOR_S "qemu-ga.pid");
 140 }
 141
 142 static void quit_handler(int sig)
 143 {
 144     /* if we're frozen, don't exit unless we're absolutely forced to,
 145      * because it's basically impossible for graceful exit to complete
 146      * unless all log/pid files are on unfreezable filesystems. there's
 147      * also a very likely chance killing the agent before unfreezing
 148      * the filesystems is a mistake (or will be viewed as one later).
 149      * On Windows the freeze interval is limited to 10 seconds, so
 150      * we should quit, but first we should wait for the timeout, thaw
 151      * the filesystem and quit.
 152      */
 153     if (ga_is_frozen(ga_state)) {
 154 #ifdef _WIN32
 155         int i = 0;
 156         Error *err = NULL;
 157         HANDLE hEventTimeout;
 158
 159         g_debug("Thawing filesystems before exiting");
 160
 161         hEventTimeout = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_TIMEOUT);
 162         if (hEventTimeout) {
 163             WaitForSingleObject(hEventTimeout, 0);
 164             CloseHandle(hEventTimeout);
 165         }
 166         qga_vss_fsfreeze(&i, false, NULL, &err);
 167         if (err) {
 168             g_debug("Error unfreezing filesystems prior to exiting: %s",
 169                 error_get_pretty(err));
 170             error_free(err);
 171         }
 172 #else
 173         return;
 174 #endif
 175     }
 176     g_debug("received signal num %d, quitting", sig);
 177
 178     stop_agent(ga_state, true);
 179 }
 180
 181 #ifndef _WIN32
 182 static gboolean register_signal_handlers(void)
 183 {
 184     struct sigaction sigact;
 185     int ret;
 186
 187     memset(&sigact, 0, sizeof(struct sigaction));
 188     sigact.sa_handler = quit_handler;
 189
 190     ret = sigaction(SIGINT, &sigact, NULL);
 191     if (ret == -1) {
 192         g_error("error configuring signal handler: %s", strerror(errno));
 193     }
 194     ret = sigaction(SIGTERM, &sigact, NULL);
 195     if (ret == -1) {
 196         g_error("error configuring signal handler: %s", strerror(errno));
 197     }
 198
 199     sigact.sa_handler = SIG_IGN;
 200     if (sigaction(SIGPIPE, &sigact, NULL) != 0) {
 201         g_error("error configuring SIGPIPE signal handler: %s",
 202                 strerror(errno));
 203     }
 204
 205     return true;
 206 }
 207
 208 /* TODO: use this in place of all post-fork() fclose(std*) callers */
 209 void reopen_fd_to_null(int fd)
 210 {
 211     int nullfd;
 212
 213     nullfd = open("/dev/null", O_RDWR);
 214     if (nullfd < 0) {
 215         return;
 216     }
 217
 218     dup2(nullfd, fd);
 219
 220     if (nullfd != fd) {
 221         close(nullfd);
 222     }
 223 }
 224 #endif
 225
 226 static void usage(const char *cmd)
 227 {
 228     printf(
 229 "Usage: %s [-m <method> -p <path>] [<options>]\n"
 230 "QEMU Guest Agent " QEMU_FULL_VERSION "\n"
 231 QEMU_COPYRIGHT "\n"
 232 "\n"
 233 "  -m, --method      transport method: one of unix-listen, virtio-serial,\n"
 234 "                    isa-serial, or vsock-listen (virtio-serial is the default)\n"
 235 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
 236 "                    %s,\n"
 237 "                    the default for isa-serial is:\n"
 238 "                    %s).\n"
 239 "                    Socket addresses for vsock-listen are written as\n"
 240 "                    <cid>:<port>.\n"
 241 "  -l, --logfile     set logfile path, logs to stderr by default\n"
 242 "  -f, --pidfile     specify pidfile (default is %s)\n"
 243 #ifdef CONFIG_FSFREEZE
 244 "  -F, --fsfreeze-hook\n"
 245 "                    enable fsfreeze hook. Accepts an optional argument that\n"
 246 "                    specifies script to run on freeze/thaw. Script will be\n"
 247 "                    called with 'freeze'/'thaw' arguments accordingly.\n"
 248 "                    (default is %s)\n"
 249 "                    If using -F with an argument, do not follow -F with a\n"
 250 "                    space.\n"
 251 "                    (for example: -F/var/run/fsfreezehook.sh)\n"
 252 #endif
 253 "  -t, --statedir    specify dir to store state information (absolute paths\n"
 254 "                    only, default is %s)\n"
 255 "  -v, --verbose     log extra debugging information\n"
 256 "  -V, --version     print version information and exit\n"
 257 "  -d, --daemonize   become a daemon\n"
 258 #ifdef _WIN32
 259 "  -s, --service     service commands: install, uninstall, vss-install, vss-uninstall\n"
 260 #endif
 261 "  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\"\n"
 262 "                    to list available RPCs)\n"
 263 "  -D, --dump-conf   dump a qemu-ga config file based on current config\n"
 264 "                    options / command-line parameters to stdout\n"
 265 "  -r, --retry-path  attempt re-opening path if it's unavailable or closed\n"
 266 "                    due to an error which may be recoverable in the future\n"
 267 "                    (virtio-serial driver re-install, serial device hot\n"
 268 "                    plug/unplug, etc.)\n"
 269 "  -h, --help        display this help and exit\n"
 270 "\n"
 271 QEMU_HELP_BOTTOM "\n"
 272     , cmd, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT,
 273     dfl_pathnames.pidfile,
 274 #ifdef CONFIG_FSFREEZE
 275     QGA_FSFREEZE_HOOK_DEFAULT,
 276 #endif
 277     dfl_pathnames.state_dir);
 278 }
 279
 280 static const char *ga_log_level_str(GLogLevelFlags level)
 281 {
 282     switch (level & G_LOG_LEVEL_MASK) {
 283         case G_LOG_LEVEL_ERROR:
 284             return "error";
 285         case G_LOG_LEVEL_CRITICAL:
 286             return "critical";
 287         case G_LOG_LEVEL_WARNING:
 288             return "warning";
 289         case G_LOG_LEVEL_MESSAGE:
 290             return "message";
 291         case G_LOG_LEVEL_INFO:
 292             return "info";
 293         case G_LOG_LEVEL_DEBUG:
 294             return "debug";
 295         default:
 296             return "user";
 297     }
 298 }
 299
 300 bool ga_logging_enabled(GAState *s)
 301 {
 302     return s->logging_enabled;
 303 }
 304
 305 void ga_disable_logging(GAState *s)
 306 {
 307     s->logging_enabled = false;
 308 }
 309
 310 void ga_enable_logging(GAState *s)
 311 {
 312     s->logging_enabled = true;
 313 }
 314
 315 static void ga_log(const gchar *domain, GLogLevelFlags level,
 316                    const gchar *msg, gpointer opaque)
 317 {
 318     GAState *s = opaque;
 319     GTimeVal time;
 320     const char *level_str = ga_log_level_str(level);
 321
 322     if (!ga_logging_enabled(s)) {
 323         return;
 324     }
 325
 326     level &= G_LOG_LEVEL_MASK;
 327 #ifndef _WIN32
 328     if (g_strcmp0(domain, "syslog") == 0) {
 329         syslog(LOG_INFO, "%s: %s", level_str, msg);
 330     } else if (level & s->log_level) {
 331 #else
 332     if (level & s->log_level) {
 333 #endif
 334         g_get_current_time(&time);
 335         fprintf(s->log_file,
 336                 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
 337         fflush(s->log_file);
 338     }
 339 }
 340
 341 void ga_set_response_delimited(GAState *s)
 342 {
 343     s->delimit_response = true;
 344 }
 345
 346 static FILE *ga_open_logfile(const char *logfile)
 347 {
 348     FILE *f;
 349
 350     f = fopen(logfile, "a");
 351     if (!f) {
 352         return NULL;
 353     }
 354
 355     qemu_set_cloexec(fileno(f));
 356     return f;
 357 }
 358
 359 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
 360 {
 361     return strcmp(str1, str2);
 362 }
 363
 364 /* disable commands that aren't safe for fsfreeze */
 365 static void ga_disable_non_whitelisted(const QmpCommand *cmd, void *opaque)
 366 {
 367     bool whitelisted = false;
 368     int i = 0;
 369     const char *name = qmp_command_name(cmd);
 370
 371     while (ga_freeze_whitelist[i] != NULL) {
 372         if (strcmp(name, ga_freeze_whitelist[i]) == 0) {
 373             whitelisted = true;
 374         }
 375         i++;
 376     }
 377     if (!whitelisted) {
 378         g_debug("disabling command: %s", name);
 379         qmp_disable_command(&ga_commands, name);
 380     }
 381 }
 382
 383 /* [re-]enable all commands, except those explicitly blacklisted by user */
 384 static void ga_enable_non_blacklisted(const QmpCommand *cmd, void *opaque)
 385 {
 386     GList *blacklist = opaque;
 387     const char *name = qmp_command_name(cmd);
 388
 389     if (g_list_find_custom(blacklist, name, ga_strcmp) == NULL &&
 390         !qmp_command_is_enabled(cmd)) {
 391         g_debug("enabling command: %s", name);
 392         qmp_enable_command(&ga_commands, name);
 393     }
 394 }
 395
 396 static bool ga_create_file(const char *path)
 397 {
 398     int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
 399     if (fd == -1) {
 400         g_warning("unable to open/create file %s: %s", path, strerror(errno));
 401         return false;
 402     }
 403     close(fd);
 404     return true;
 405 }
 406
 407 static bool ga_delete_file(const char *path)
 408 {
 409     int ret = unlink(path);
 410     if (ret == -1) {
 411         g_warning("unable to delete file: %s: %s", path, strerror(errno));
 412         return false;
 413     }
 414
 415     return true;
 416 }
 417
 418 bool ga_is_frozen(GAState *s)
 419 {
 420     return s->frozen;
 421 }
 422
 423 void ga_set_frozen(GAState *s)
 424 {
 425     if (ga_is_frozen(s)) {
 426         return;
 427     }
 428     /* disable all non-whitelisted (for frozen state) commands */
 429     qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
 430     g_warning("disabling logging due to filesystem freeze");
 431     ga_disable_logging(s);
 432     s->frozen = true;
 433     if (!ga_create_file(s->state_filepath_isfrozen)) {
 434         g_warning("unable to create %s, fsfreeze may not function properly",
 435                   s->state_filepath_isfrozen);
 436     }
 437 }
 438
 439 void ga_unset_frozen(GAState *s)
 440 {
 441     if (!ga_is_frozen(s)) {
 442         return;
 443     }
 444
 445     /* if we delayed creation/opening of pid/log files due to being
 446      * in a frozen state at start up, do it now
 447      */
 448     if (s->deferred_options.log_filepath) {
 449         s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
 450         if (!s->log_file) {
 451             s->log_file = stderr;
 452         }
 453         s->deferred_options.log_filepath = NULL;
 454     }
 455     ga_enable_logging(s);
 456     g_warning("logging re-enabled due to filesystem unfreeze");
 457     if (s->deferred_options.pid_filepath) {
 458         Error *err = NULL;
 459
 460         if (!qemu_write_pidfile(s->deferred_options.pid_filepath, &err)) {
 461             g_warning("%s", error_get_pretty(err));
 462             error_free(err);
 463         }
 464         s->deferred_options.pid_filepath = NULL;
 465     }
 466
 467     /* enable all disabled, non-blacklisted commands */
 468     qmp_for_each_command(&ga_commands, ga_enable_non_blacklisted, s->blacklist);
 469     s->frozen = false;
 470     if (!ga_delete_file(s->state_filepath_isfrozen)) {
 471         g_warning("unable to delete %s, fsfreeze may not function properly",
 472                   s->state_filepath_isfrozen);
 473     }
 474 }
 475
 476 #ifdef CONFIG_FSFREEZE
 477 const char *ga_fsfreeze_hook(GAState *s)
 478 {
 479     return s->fsfreeze_hook;
 480 }
 481 #endif
 482
 483 static void become_daemon(const char *pidfile)
 484 {
 485 #ifndef _WIN32
 486     pid_t pid, sid;
 487
 488     pid = fork();
 489     if (pid < 0) {
 490         exit(EXIT_FAILURE);
 491     }
 492     if (pid > 0) {
 493         exit(EXIT_SUCCESS);
 494     }
 495
 496     if (pidfile) {
 497         Error *err = NULL;
 498
 499         if (!qemu_write_pidfile(pidfile, &err)) {
 500             g_critical("%s", error_get_pretty(err));
 501             error_free(err);
 502             exit(EXIT_FAILURE);
 503         }
 504     }
 505
 506     umask(S_IRWXG | S_IRWXO);
 507     sid = setsid();
 508     if (sid < 0) {
 509         goto fail;
 510     }
 511     if ((chdir("/")) < 0) {
 512         goto fail;
 513     }
 514
 515     reopen_fd_to_null(STDIN_FILENO);
 516     reopen_fd_to_null(STDOUT_FILENO);
 517     reopen_fd_to_null(STDERR_FILENO);
 518     return;
 519
 520 fail:
 521     if (pidfile) {
 522         unlink(pidfile);
 523     }
 524     g_critical("failed to daemonize");
 525     exit(EXIT_FAILURE);
 526 #endif
 527 }
 528
 529 static int send_response(GAState *s, const QDict *rsp)
 530 {
 531     const char *buf;
 532     QString *payload_qstr, *response_qstr;
 533     GIOStatus status;
 534
 535     g_assert(s->channel);
 536
 537     if (!rsp) {
 538         return 0;
 539     }
 540
 541     payload_qstr = qobject_to_json(QOBJECT(rsp));
 542     if (!payload_qstr) {
 543         return -EINVAL;
 544     }
 545
 546     if (s->delimit_response) {
 547         s->delimit_response = false;
 548         response_qstr = qstring_new();
 549         qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
 550         qstring_append(response_qstr, qstring_get_str(payload_qstr));
 551         qobject_unref(payload_qstr);
 552     } else {
 553         response_qstr = payload_qstr;
 554     }
 555
 556     qstring_append_chr(response_qstr, '\n');
 557     buf = qstring_get_str(response_qstr);
 558     status = ga_channel_write_all(s->channel, buf, strlen(buf));
 559     qobject_unref(response_qstr);
 560     if (status != G_IO_STATUS_NORMAL) {
 561         return -EIO;
 562     }
 563
 564     return 0;
 565 }
 566
 567 /* handle requests/control events coming in over the channel */
 568 static void process_event(void *opaque, QObject *obj, Error *err)
 569 {
 570     GAState *s = opaque;
 571     QDict *rsp;
 572     int ret;
 573
 574     g_debug("process_event: called");
 575     assert(!obj != !err);
 576     if (err) {
 577         rsp = qmp_error_response(err);
 578         goto end;
 579     }
 580
 581     g_debug("processing command");
 582     rsp = qmp_dispatch(&ga_commands, obj, false, NULL);
 583
 584 end:
 585     ret = send_response(s, rsp);
 586     if (ret < 0) {
 587         g_warning("error sending error response: %s", strerror(-ret));
 588     }
 589     qobject_unref(rsp);
 590     qobject_unref(obj);
 591 }
 592
 593 /* false return signals GAChannel to close the current client connection */
 594 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 595 {
 596     GAState *s = data;
 597     gchar buf[QGA_READ_COUNT_DEFAULT+1];
 598     gsize count;
 599     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 600     switch (status) {
 601     case G_IO_STATUS_ERROR:
 602         g_warning("error reading channel");
 603         stop_agent(s, false);
 604         return false;
 605     case G_IO_STATUS_NORMAL:
 606         buf[count] = 0;
 607         g_debug("read data, count: %d, data: %s", (int)count, buf);
 608         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 609         break;
 610     case G_IO_STATUS_EOF:
 611         g_debug("received EOF");
 612         if (!s->virtio) {
 613             return false;
 614         }
 615         /* fall through */
 616     case G_IO_STATUS_AGAIN:
 617         /* virtio causes us to spin here when no process is attached to
 618          * host-side chardev. sleep a bit to mitigate this
 619          */
 620         if (s->virtio) {
 621             usleep(100*1000);
 622         }
 623         return true;
 624     default:
 625         g_warning("unknown channel read status, closing");
 626         return false;
 627     }
 628     return true;
 629 }
 630
 631 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path,
 632                              int listen_fd)
 633 {
 634     GAChannelMethod channel_method;
 635
 636     if (strcmp(method, "virtio-serial") == 0) {
 637         s->virtio = true; /* virtio requires special handling in some cases */
 638         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 639     } else if (strcmp(method, "isa-serial") == 0) {
 640         channel_method = GA_CHANNEL_ISA_SERIAL;
 641     } else if (strcmp(method, "unix-listen") == 0) {
 642         channel_method = GA_CHANNEL_UNIX_LISTEN;
 643     } else if (strcmp(method, "vsock-listen") == 0) {
 644         channel_method = GA_CHANNEL_VSOCK_LISTEN;
 645     } else {
 646         g_critical("unsupported channel method/type: %s", method);
 647         return false;
 648     }
 649
 650     s->channel = ga_channel_new(channel_method, path, listen_fd,
 651                                 channel_event_cb, s);
 652     if (!s->channel) {
 653         g_critical("failed to create guest agent channel");
 654         return false;
 655     }
 656
 657     return true;
 658 }
 659
 660 #ifdef _WIN32
 661 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data)
 662 {
 663     DWORD ret = NO_ERROR;
 664     PDEV_BROADCAST_HDR broadcast_header = (PDEV_BROADCAST_HDR)data;
 665
 666     if (broadcast_header->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE) {
 667         switch (type) {
 668             /* Device inserted */
 669         case DBT_DEVICEARRIVAL:
 670             /* Start QEMU-ga's service */
 671             if (!SetEvent(ga_state->wakeup_event)) {
 672                 ret = GetLastError();
 673             }
 674             break;
 675             /* Device removed */
 676         case DBT_DEVICEQUERYREMOVE:
 677         case DBT_DEVICEREMOVEPENDING:
 678         case DBT_DEVICEREMOVECOMPLETE:
 679             /* Stop QEMU-ga's service */
 680             if (!ResetEvent(ga_state->wakeup_event)) {
 681                 ret = GetLastError();
 682             }
 683             break;
 684         default:
 685             ret = ERROR_CALL_NOT_IMPLEMENTED;
 686         }
 687     }
 688     return ret;
 689 }
 690
 691 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 692                                   LPVOID ctx)
 693 {
 694     DWORD ret = NO_ERROR;
 695     GAService *service = &ga_state->service;
 696
 697     switch (ctrl)
 698     {
 699         case SERVICE_CONTROL_STOP:
 700         case SERVICE_CONTROL_SHUTDOWN:
 701             quit_handler(SIGTERM);
 702             SetEvent(ga_state->wakeup_event);
 703             service->status.dwCurrentState = SERVICE_STOP_PENDING;
 704             SetServiceStatus(service->status_handle, &service->status);
 705             break;
 706         case SERVICE_CONTROL_DEVICEEVENT:
 707             handle_serial_device_events(type, data);
 708             break;
 709
 710         default:
 711             ret = ERROR_CALL_NOT_IMPLEMENTED;
 712     }
 713     return ret;
 714 }
 715
 716 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 717 {
 718     GAService *service = &ga_state->service;
 719
 720     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 721         service_ctrl_handler, NULL);
 722
 723     if (service->status_handle == 0) {
 724         g_critical("Failed to register extended requests function!\n");
 725         return;
 726     }
 727
 728     service->status.dwServiceType = SERVICE_WIN32;
 729     service->status.dwCurrentState = SERVICE_RUNNING;
 730     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 731     service->status.dwWin32ExitCode = NO_ERROR;
 732     service->status.dwServiceSpecificExitCode = NO_ERROR;
 733     service->status.dwCheckPoint = 0;
 734     service->status.dwWaitHint = 0;
 735     DEV_BROADCAST_DEVICEINTERFACE notification_filter;
 736     ZeroMemory(&notification_filter, sizeof(notification_filter));
 737     notification_filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
 738     notification_filter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
 739     notification_filter.dbcc_classguid = GUID_VIOSERIAL_PORT;
 740
 741     service->device_notification_handle =
 742         RegisterDeviceNotification(service->status_handle,
 743             &notification_filter, DEVICE_NOTIFY_SERVICE_HANDLE);
 744     if (!service->device_notification_handle) {
 745         g_critical("Failed to register device notification handle!\n");
 746         return;
 747     }
 748     SetServiceStatus(service->status_handle, &service->status);
 749
 750     run_agent(ga_state);
 751
 752     UnregisterDeviceNotification(service->device_notification_handle);
 753     service->status.dwCurrentState = SERVICE_STOPPED;
 754     SetServiceStatus(service->status_handle, &service->status);
 755 }
 756 #endif
 757
 758 static void set_persistent_state_defaults(GAPersistentState *pstate)
 759 {
 760     g_assert(pstate);
 761     pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
 762 }
 763
 764 static void persistent_state_from_keyfile(GAPersistentState *pstate,
 765                                           GKeyFile *keyfile)
 766 {
 767     g_assert(pstate);
 768     g_assert(keyfile);
 769     /* if any fields are missing, either because the file was tampered with
 770      * by agents of chaos, or because the field wasn't present at the time the
 771      * file was created, the best we can ever do is start over with the default
 772      * values. so load them now, and ignore any errors in accessing key-value
 773      * pairs
 774      */
 775     set_persistent_state_defaults(pstate);
 776
 777     if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
 778         pstate->fd_counter =
 779             g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
 780     }
 781 }
 782
 783 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
 784                                         GKeyFile *keyfile)
 785 {
 786     g_assert(pstate);
 787     g_assert(keyfile);
 788
 789     g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
 790 }
 791
 792 static gboolean write_persistent_state(const GAPersistentState *pstate,
 793                                        const gchar *path)
 794 {
 795     GKeyFile *keyfile = g_key_file_new();
 796     GError *gerr = NULL;
 797     gboolean ret = true;
 798     gchar *data = NULL;
 799     gsize data_len;
 800
 801     g_assert(pstate);
 802
 803     persistent_state_to_keyfile(pstate, keyfile);
 804     data = g_key_file_to_data(keyfile, &data_len, &gerr);
 805     if (gerr) {
 806         g_critical("failed to convert persistent state to string: %s",
 807                    gerr->message);
 808         ret = false;
 809         goto out;
 810     }
 811
 812     g_file_set_contents(path, data, data_len, &gerr);
 813     if (gerr) {
 814         g_critical("failed to write persistent state to %s: %s",
 815                     path, gerr->message);
 816         ret = false;
 817         goto out;
 818     }
 819
 820 out:
 821     if (gerr) {
 822         g_error_free(gerr);
 823     }
 824     if (keyfile) {
 825         g_key_file_free(keyfile);
 826     }
 827     g_free(data);
 828     return ret;
 829 }
 830
 831 static gboolean read_persistent_state(GAPersistentState *pstate,
 832                                       const gchar *path, gboolean frozen)
 833 {
 834     GKeyFile *keyfile = NULL;
 835     GError *gerr = NULL;
 836     struct stat st;
 837     gboolean ret = true;
 838
 839     g_assert(pstate);
 840
 841     if (stat(path, &st) == -1) {
 842         /* it's okay if state file doesn't exist, but any other error
 843          * indicates a permissions issue or some other misconfiguration
 844          * that we likely won't be able to recover from.
 845          */
 846         if (errno != ENOENT) {
 847             g_critical("unable to access state file at path %s: %s",
 848                        path, strerror(errno));
 849             ret = false;
 850             goto out;
 851         }
 852
 853         /* file doesn't exist. initialize state to default values and
 854          * attempt to save now. (we could wait till later when we have
 855          * modified state we need to commit, but if there's a problem,
 856          * such as a missing parent directory, we want to catch it now)
 857          *
 858          * there is a potential scenario where someone either managed to
 859          * update the agent from a version that didn't use a key store
 860          * while qemu-ga thought the filesystem was frozen, or
 861          * deleted the key store prior to issuing a fsfreeze, prior
 862          * to restarting the agent. in this case we go ahead and defer
 863          * initial creation till we actually have modified state to
 864          * write, otherwise fail to recover from freeze.
 865          */
 866         set_persistent_state_defaults(pstate);
 867         if (!frozen) {
 868             ret = write_persistent_state(pstate, path);
 869             if (!ret) {
 870                 g_critical("unable to create state file at path %s", path);
 871                 ret = false;
 872                 goto out;
 873             }
 874         }
 875         ret = true;
 876         goto out;
 877     }
 878
 879     keyfile = g_key_file_new();
 880     g_key_file_load_from_file(keyfile, path, 0, &gerr);
 881     if (gerr) {
 882         g_critical("error loading persistent state from path: %s, %s",
 883                    path, gerr->message);
 884         ret = false;
 885         goto out;
 886     }
 887
 888     persistent_state_from_keyfile(pstate, keyfile);
 889
 890 out:
 891     if (keyfile) {
 892         g_key_file_free(keyfile);
 893     }
 894     if (gerr) {
 895         g_error_free(gerr);
 896     }
 897
 898     return ret;
 899 }
 900
 901 int64_t ga_get_fd_handle(GAState *s, Error **errp)
 902 {
 903     int64_t handle;
 904
 905     g_assert(s->pstate_filepath);
 906     /* we blacklist commands and avoid operations that potentially require
 907      * writing to disk when we're in a frozen state. this includes opening
 908      * new files, so we should never get here in that situation
 909      */
 910     g_assert(!ga_is_frozen(s));
 911
 912     handle = s->pstate.fd_counter++;
 913
 914     /* This should never happen on a reasonable timeframe, as guest-file-open
 915      * would have to be issued 2^63 times */
 916     if (s->pstate.fd_counter == INT64_MAX) {
 917         abort();
 918     }
 919
 920     if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
 921         error_setg(errp, "failed to commit persistent state to disk");
 922         return -1;
 923     }
 924
 925     return handle;
 926 }
 927
 928 static void ga_print_cmd(const QmpCommand *cmd, void *opaque)
 929 {
 930     printf("%s\n", qmp_command_name(cmd));
 931 }
 932
 933 static GList *split_list(const gchar *str, const gchar *delim)
 934 {
 935     GList *list = NULL;
 936     int i;
 937     gchar **strv;
 938
 939     strv = g_strsplit(str, delim, -1);
 940     for (i = 0; strv[i]; i++) {
 941         list = g_list_prepend(list, strv[i]);
 942     }
 943     g_free(strv);
 944
 945     return list;
 946 }
 947
 948 struct GAConfig {
 949     char *channel_path;
 950     char *method;
 951     char *log_filepath;
 952     char *pid_filepath;
 953 #ifdef CONFIG_FSFREEZE
 954     char *fsfreeze_hook;
 955 #endif
 956     char *state_dir;
 957 #ifdef _WIN32
 958     const char *service;
 959 #endif
 960     gchar *bliststr; /* blacklist may point to this string */
 961     GList *blacklist;
 962     int daemonize;
 963     GLogLevelFlags log_level;
 964     int dumpconf;
 965     bool retry_path;
 966 };
 967
 968 static void config_load(GAConfig *config)
 969 {
 970     GError *gerr = NULL;
 971     GKeyFile *keyfile;
 972     g_autofree char *conf = g_strdup(g_getenv("QGA_CONF")) ?: get_relocated_path(QGA_CONF_DEFAULT);
 973
 974     /* read system config */
 975     keyfile = g_key_file_new();
 976     if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
 977         goto end;
 978     }
 979     if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
 980         config->daemonize =
 981             g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
 982     }
 983     if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
 984         config->method =
 985             g_key_file_get_string(keyfile, "general", "method", &gerr);
 986     }
 987     if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
 988         config->channel_path =
 989             g_key_file_get_string(keyfile, "general", "path", &gerr);
 990     }
 991     if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
 992         config->log_filepath =
 993             g_key_file_get_string(keyfile, "general", "logfile", &gerr);
 994     }
 995     if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
 996         config->pid_filepath =
 997             g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
 998     }
 999 #ifdef CONFIG_FSFREEZE
1000     if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
1001         config->fsfreeze_hook =
1002             g_key_file_get_string(keyfile,
1003                                   "general", "fsfreeze-hook", &gerr);
1004     }
1005 #endif
1006     if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
1007         config->state_dir =
1008             g_key_file_get_string(keyfile, "general", "statedir", &gerr);
1009     }
1010     if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
1011         g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
1012         /* enable all log levels */
1013         config->log_level = G_LOG_LEVEL_MASK;
1014     }
1015     if (g_key_file_has_key(keyfile, "general", "retry-path", NULL)) {
1016         config->retry_path =
1017             g_key_file_get_boolean(keyfile, "general", "retry-path", &gerr);
1018     }
1019     if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
1020         config->bliststr =
1021             g_key_file_get_string(keyfile, "general", "blacklist", &gerr);
1022         config->blacklist = g_list_concat(config->blacklist,
1023                                           split_list(config->bliststr, ","));
1024     }
1025
1026 end:
1027     g_key_file_free(keyfile);
1028     if (gerr &&
1029         !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
1030         g_critical("error loading configuration from path: %s, %s",
1031                    conf, gerr->message);
1032         exit(EXIT_FAILURE);
1033     }
1034     g_clear_error(&gerr);
1035 }
1036
1037 static gchar *list_join(GList *list, const gchar separator)
1038 {
1039     GString *str = g_string_new("");
1040
1041     while (list) {
1042         str = g_string_append(str, (gchar *)list->data);
1043         list = g_list_next(list);
1044         if (list) {
1045             str = g_string_append_c(str, separator);
1046         }
1047     }
1048
1049     return g_string_free(str, FALSE);
1050 }
1051
1052 static void config_dump(GAConfig *config)
1053 {
1054     GError *error = NULL;
1055     GKeyFile *keyfile;
1056     gchar *tmp;
1057
1058     keyfile = g_key_file_new();
1059     g_assert(keyfile);
1060
1061     g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1062     g_key_file_set_string(keyfile, "general", "method", config->method);
1063     if (config->channel_path) {
1064         g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1065     }
1066     if (config->log_filepath) {
1067         g_key_file_set_string(keyfile, "general", "logfile",
1068                               config->log_filepath);
1069     }
1070     g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1071 #ifdef CONFIG_FSFREEZE
1072     if (config->fsfreeze_hook) {
1073         g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1074                               config->fsfreeze_hook);
1075     }
1076 #endif
1077     g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1078     g_key_file_set_boolean(keyfile, "general", "verbose",
1079                            config->log_level == G_LOG_LEVEL_MASK);
1080     g_key_file_set_boolean(keyfile, "general", "retry-path",
1081                            config->retry_path);
1082     tmp = list_join(config->blacklist, ',');
1083     g_key_file_set_string(keyfile, "general", "blacklist", tmp);
1084     g_free(tmp);
1085
1086     tmp = g_key_file_to_data(keyfile, NULL, &error);
1087     if (error) {
1088         g_critical("Failed to dump keyfile: %s", error->message);
1089         g_clear_error(&error);
1090     } else {
1091         printf("%s", tmp);
1092     }
1093
1094     g_free(tmp);
1095     g_key_file_free(keyfile);
1096 }
1097
1098 static void config_parse(GAConfig *config, int argc, char **argv)
1099 {
1100     const char *sopt = "hVvdm:p:l:f:F::b:s:t:Dr";
1101     int opt_ind = 0, ch;
1102     const struct option lopt[] = {
1103         { "help", 0, NULL, 'h' },
1104         { "version", 0, NULL, 'V' },
1105         { "dump-conf", 0, NULL, 'D' },
1106         { "logfile", 1, NULL, 'l' },
1107         { "pidfile", 1, NULL, 'f' },
1108 #ifdef CONFIG_FSFREEZE
1109         { "fsfreeze-hook", 2, NULL, 'F' },
1110 #endif
1111         { "verbose", 0, NULL, 'v' },
1112         { "method", 1, NULL, 'm' },
1113         { "path", 1, NULL, 'p' },
1114         { "daemonize", 0, NULL, 'd' },
1115         { "blacklist", 1, NULL, 'b' },
1116 #ifdef _WIN32
1117         { "service", 1, NULL, 's' },
1118 #endif
1119         { "statedir", 1, NULL, 't' },
1120         { "retry-path", 0, NULL, 'r' },
1121         { NULL, 0, NULL, 0 }
1122     };
1123
1124     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1125         switch (ch) {
1126         case 'm':
1127             g_free(config->method);
1128             config->method = g_strdup(optarg);
1129             break;
1130         case 'p':
1131             g_free(config->channel_path);
1132             config->channel_path = g_strdup(optarg);
1133             break;
1134         case 'l':
1135             g_free(config->log_filepath);
1136             config->log_filepath = g_strdup(optarg);
1137             break;
1138         case 'f':
1139             g_free(config->pid_filepath);
1140             config->pid_filepath = g_strdup(optarg);
1141             break;
1142 #ifdef CONFIG_FSFREEZE
1143         case 'F':
1144             g_free(config->fsfreeze_hook);
1145             config->fsfreeze_hook = optarg ? g_strdup(optarg) : get_relocated_path(QGA_FSFREEZE_HOOK_DEFAULT);
1146             break;
1147 #endif
1148         case 't':
1149             g_free(config->state_dir);
1150             config->state_dir = g_strdup(optarg);
1151             break;
1152         case 'v':
1153             /* enable all log levels */
1154             config->log_level = G_LOG_LEVEL_MASK;
1155             break;
1156         case 'V':
1157             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1158             exit(EXIT_SUCCESS);
1159         case 'd':
1160             config->daemonize = 1;
1161             break;
1162         case 'D':
1163             config->dumpconf = 1;
1164             break;
1165         case 'r':
1166             config->retry_path = true;
1167             break;
1168         case 'b': {
1169             if (is_help_option(optarg)) {
1170                 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1171                 exit(EXIT_SUCCESS);
1172             }
1173             config->blacklist = g_list_concat(config->blacklist,
1174                                              split_list(optarg, ","));
1175             break;
1176         }
1177 #ifdef _WIN32
1178         case 's':
1179             config->service = optarg;
1180             if (strcmp(config->service, "install") == 0) {
1181                 if (ga_install_vss_provider()) {
1182                     exit(EXIT_FAILURE);
1183                 }
1184                 if (ga_install_service(config->channel_path,
1185                                        config->log_filepath, config->state_dir)) {
1186                     exit(EXIT_FAILURE);
1187                 }
1188                 exit(EXIT_SUCCESS);
1189             } else if (strcmp(config->service, "uninstall") == 0) {
1190                 ga_uninstall_vss_provider();
1191                 exit(ga_uninstall_service());
1192             } else if (strcmp(config->service, "vss-install") == 0) {
1193                 if (ga_install_vss_provider()) {
1194                     exit(EXIT_FAILURE);
1195                 }
1196                 exit(EXIT_SUCCESS);
1197             } else if (strcmp(config->service, "vss-uninstall") == 0) {
1198                 ga_uninstall_vss_provider();
1199                 exit(EXIT_SUCCESS);
1200             } else {
1201                 printf("Unknown service command.\n");
1202                 exit(EXIT_FAILURE);
1203             }
1204             break;
1205 #endif
1206         case 'h':
1207             usage(argv[0]);
1208             exit(EXIT_SUCCESS);
1209         case '?':
1210             g_print("Unknown option, try '%s --help' for more information.\n",
1211                     argv[0]);
1212             exit(EXIT_FAILURE);
1213         }
1214     }
1215 }
1216
1217 static void config_free(GAConfig *config)
1218 {
1219     g_free(config->method);
1220     g_free(config->log_filepath);
1221     g_free(config->pid_filepath);
1222     g_free(config->state_dir);
1223     g_free(config->channel_path);
1224     g_free(config->bliststr);
1225 #ifdef CONFIG_FSFREEZE
1226     g_free(config->fsfreeze_hook);
1227 #endif
1228     g_list_free_full(config->blacklist, g_free);
1229     g_free(config);
1230 }
1231
1232 static bool check_is_frozen(GAState *s)
1233 {
1234 #ifndef _WIN32
1235     /* check if a previous instance of qemu-ga exited with filesystems' state
1236      * marked as frozen. this could be a stale value (a non-qemu-ga process
1237      * or reboot may have since unfrozen them), but better to require an
1238      * uneeded unfreeze than to risk hanging on start-up
1239      */
1240     struct stat st;
1241     if (stat(s->state_filepath_isfrozen, &st) == -1) {
1242         /* it's okay if the file doesn't exist, but if we can't access for
1243          * some other reason, such as permissions, there's a configuration
1244          * that needs to be addressed. so just bail now before we get into
1245          * more trouble later
1246          */
1247         if (errno != ENOENT) {
1248             g_critical("unable to access state file at path %s: %s",
1249                        s->state_filepath_isfrozen, strerror(errno));
1250             return EXIT_FAILURE;
1251         }
1252     } else {
1253         g_warning("previous instance appears to have exited with frozen"
1254                   " filesystems. deferring logging/pidfile creation and"
1255                   " disabling non-fsfreeze-safe commands until"
1256                   " guest-fsfreeze-thaw is issued, or filesystems are"
1257                   " manually unfrozen and the file %s is removed",
1258                   s->state_filepath_isfrozen);
1259         return true;
1260     }
1261 #endif
1262     return false;
1263 }
1264
1265 static GAState *initialize_agent(GAConfig *config, int socket_activation)
1266 {
1267     GAState *s = g_new0(GAState, 1);
1268
1269     g_assert(ga_state == NULL);
1270
1271     s->log_level = config->log_level;
1272     s->log_file = stderr;
1273 #ifdef CONFIG_FSFREEZE
1274     s->fsfreeze_hook = config->fsfreeze_hook;
1275 #endif
1276     s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1277     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1278                                                  config->state_dir);
1279     s->frozen = check_is_frozen(s);
1280
1281     g_log_set_default_handler(ga_log, s);
1282     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1283     ga_enable_logging(s);
1284
1285 #ifdef _WIN32
1286     /* On win32 the state directory is application specific (be it the default
1287      * or a user override). We got past the command line parsing; let's create
1288      * the directory (with any intermediate directories). If we run into an
1289      * error later on, we won't try to clean up the directory, it is considered
1290      * persistent.
1291      */
1292     if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1293         g_critical("unable to create (an ancestor of) the state directory"
1294                    " '%s': %s", config->state_dir, strerror(errno));
1295         return NULL;
1296     }
1297 #endif
1298
1299     if (ga_is_frozen(s)) {
1300         if (config->daemonize) {
1301             /* delay opening/locking of pidfile till filesystems are unfrozen */
1302             s->deferred_options.pid_filepath = config->pid_filepath;
1303             become_daemon(NULL);
1304         }
1305         if (config->log_filepath) {
1306             /* delay opening the log file till filesystems are unfrozen */
1307             s->deferred_options.log_filepath = config->log_filepath;
1308         }
1309         ga_disable_logging(s);
1310         qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
1311     } else {
1312         if (config->daemonize) {
1313             become_daemon(config->pid_filepath);
1314         }
1315         if (config->log_filepath) {
1316             FILE *log_file = ga_open_logfile(config->log_filepath);
1317             if (!log_file) {
1318                 g_critical("unable to open specified log file: %s",
1319                            strerror(errno));
1320                 return NULL;
1321             }
1322             s->log_file = log_file;
1323         }
1324     }
1325
1326     /* load persistent state from disk */
1327     if (!read_persistent_state(&s->pstate,
1328                                s->pstate_filepath,
1329                                ga_is_frozen(s))) {
1330         g_critical("failed to load persistent state");
1331         return NULL;
1332     }
1333
1334     config->blacklist = ga_command_blacklist_init(config->blacklist);
1335     if (config->blacklist) {
1336         GList *l = config->blacklist;
1337         s->blacklist = config->blacklist;
1338         do {
1339             g_debug("disabling command: %s", (char *)l->data);
1340             qmp_disable_command(&ga_commands, l->data);
1341             l = g_list_next(l);
1342         } while (l);
1343     }
1344     s->command_state = ga_command_state_new();
1345     ga_command_state_init(s, s->command_state);
1346     ga_command_state_init_all(s->command_state);
1347     json_message_parser_init(&s->parser, process_event, s, NULL);
1348
1349 #ifndef _WIN32
1350     if (!register_signal_handlers()) {
1351         g_critical("failed to register signal handlers");
1352         return NULL;
1353     }
1354 #endif
1355
1356     s->main_loop = g_main_loop_new(NULL, false);
1357
1358     s->config = config;
1359     s->socket_activation = socket_activation;
1360
1361 #ifdef _WIN32
1362     s->wakeup_event = CreateEvent(NULL, TRUE, FALSE, TEXT("WakeUp"));
1363     if (s->wakeup_event == NULL) {
1364         g_critical("CreateEvent failed");
1365         return NULL;
1366     }
1367 #endif
1368
1369     ga_state = s;
1370     return s;
1371 }
1372
1373 static void cleanup_agent(GAState *s)
1374 {
1375 #ifdef _WIN32
1376     CloseHandle(s->wakeup_event);
1377 #endif
1378     if (s->command_state) {
1379         ga_command_state_cleanup_all(s->command_state);
1380         ga_command_state_free(s->command_state);
1381         json_message_parser_destroy(&s->parser);
1382     }
1383     g_free(s->pstate_filepath);
1384     g_free(s->state_filepath_isfrozen);
1385     if (s->main_loop) {
1386         g_main_loop_unref(s->main_loop);
1387     }
1388     g_free(s);
1389     ga_state = NULL;
1390 }
1391
1392 static int run_agent_once(GAState *s)
1393 {
1394     if (!channel_init(s, s->config->method, s->config->channel_path,
1395                       s->socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
1396         g_critical("failed to initialize guest agent channel");
1397         return EXIT_FAILURE;
1398     }
1399
1400     g_main_loop_run(ga_state->main_loop);
1401
1402     if (s->channel) {
1403         ga_channel_free(s->channel);
1404     }
1405
1406     return EXIT_SUCCESS;
1407 }
1408
1409 static void wait_for_channel_availability(GAState *s)
1410 {
1411     g_warning("waiting for channel path...");
1412 #ifndef _WIN32
1413     sleep(QGA_RETRY_INTERVAL);
1414 #else
1415     DWORD dwWaitResult;
1416
1417     dwWaitResult = WaitForSingleObject(s->wakeup_event, INFINITE);
1418
1419     switch (dwWaitResult) {
1420     case WAIT_OBJECT_0:
1421         break;
1422     case WAIT_TIMEOUT:
1423         break;
1424     default:
1425         g_critical("WaitForSingleObject failed");
1426     }
1427 #endif
1428 }
1429
1430 static int run_agent(GAState *s)
1431 {
1432     int ret = EXIT_SUCCESS;
1433
1434     s->force_exit = false;
1435
1436     do {
1437         ret = run_agent_once(s);
1438         if (s->config->retry_path && !s->force_exit) {
1439             g_warning("agent stopped unexpectedly, restarting...");
1440             wait_for_channel_availability(s);
1441         }
1442     } while (s->config->retry_path && !s->force_exit);
1443
1444     return ret;
1445 }
1446
1447 static void stop_agent(GAState *s, bool requested)
1448 {
1449     if (!s->force_exit) {
1450         s->force_exit = requested;
1451     }
1452
1453     if (g_main_loop_is_running(s->main_loop)) {
1454         g_main_loop_quit(s->main_loop);
1455     }
1456 }
1457
1458 int main(int argc, char **argv)
1459 {
1460     int ret = EXIT_SUCCESS;
1461     GAState *s;
1462     GAConfig *config = g_new0(GAConfig, 1);
1463     int socket_activation;
1464
1465     config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1466
1467     qemu_init_exec_dir(argv[0]);
1468     qga_qmp_init_marshal(&ga_commands);
1469
1470     init_dfl_pathnames();
1471     config_load(config);
1472     config_parse(config, argc, argv);
1473
1474     if (config->pid_filepath == NULL) {
1475         config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1476     }
1477
1478     if (config->state_dir == NULL) {
1479         config->state_dir = g_strdup(dfl_pathnames.state_dir);
1480     }
1481
1482     if (config->method == NULL) {
1483         config->method = g_strdup("virtio-serial");
1484     }
1485
1486     socket_activation = check_socket_activation();
1487     if (socket_activation > 1) {
1488         g_critical("qemu-ga only supports listening on one socket");
1489         ret = EXIT_FAILURE;
1490         goto end;
1491     }
1492     if (socket_activation) {
1493         SocketAddress *addr;
1494
1495         g_free(config->method);
1496         g_free(config->channel_path);
1497         config->method = NULL;
1498         config->channel_path = NULL;
1499
1500         addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL);
1501         if (addr) {
1502             if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
1503                 config->method = g_strdup("unix-listen");
1504             } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
1505                 config->method = g_strdup("vsock-listen");
1506             }
1507
1508             qapi_free_SocketAddress(addr);
1509         }
1510
1511         if (!config->method) {
1512             g_critical("unsupported listen fd type");
1513             ret = EXIT_FAILURE;
1514             goto end;
1515         }
1516     } else if (config->channel_path == NULL) {
1517         if (strcmp(config->method, "virtio-serial") == 0) {
1518             /* try the default path for the virtio-serial port */
1519             config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1520         } else if (strcmp(config->method, "isa-serial") == 0) {
1521             /* try the default path for the serial port - COM1 */
1522             config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1523         } else {
1524             g_critical("must specify a path for this channel");
1525             ret = EXIT_FAILURE;
1526             goto end;
1527         }
1528     }
1529
1530     if (config->dumpconf) {
1531         config_dump(config);
1532         goto end;
1533     }
1534
1535     s = initialize_agent(config, socket_activation);
1536     if (!s) {
1537         g_critical("error initializing guest agent");
1538         goto end;
1539     }
1540
1541 #ifdef _WIN32
1542     if (config->daemonize) {
1543         SERVICE_TABLE_ENTRY service_table[] = {
1544             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1545         StartServiceCtrlDispatcher(service_table);
1546     } else {
1547         ret = run_agent(s);
1548     }
1549 #else
1550     ret = run_agent(s);
1551 #endif
1552
1553     cleanup_agent(s);
1554
1555 end:
1556     if (config->daemonize) {
1557         unlink(config->pid_filepath);
1558     }
1559
1560     config_free(config);
1561
1562     return ret;
1563 }