qga/main.c

   1 /*
   2  * QEMU Guest Agent
   3  *
   4  * Copyright IBM Corp. 2011
   5  *
   6  * Authors:
   7  *  Adam Litke        <aglitke@linux.vnet.ibm.com>
   8  *  Michael Roth      <mdroth@linux.vnet.ibm.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  11  * See the COPYING file in the top-level directory.
  12  */
  13
  14 #include "qemu/osdep.h"
  15 #include <getopt.h>
  16 #include <glib/gstdio.h>
  17 #ifndef _WIN32
  18 #include <syslog.h>
  19 #include <sys/wait.h>
  20 #endif
  21 #include "qemu/help-texts.h"
  22 #include "qapi/qmp/json-parser.h"
  23 #include "qapi/qmp/qdict.h"
  24 #include "qapi/qmp/qjson.h"
  25 #include "guest-agent-core.h"
  26 #include "qga-qapi-init-commands.h"
  27 #include "qapi/error.h"
  28 #include "channel.h"
  29 #include "qemu/cutils.h"
  30 #include "qemu/help_option.h"
  31 #include "qemu/sockets.h"
  32 #include "qemu/systemd.h"
  33 #include "qemu-version.h"
  34 #ifdef _WIN32
  35 #include <dbt.h>
  36 #include "qga/service-win32.h"
  37 #include "qga/vss-win32.h"
  38 #endif
  39 #include "commands-common.h"
  40
  41 #ifndef _WIN32
  42 #ifdef CONFIG_BSD
  43 #define QGA_VIRTIO_PATH_DEFAULT "/dev/vtcon/org.qemu.guest_agent.0"
  44 #else /* CONFIG_BSD */
  45 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
  46 #endif /* CONFIG_BSD */
  47 #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
  48 #define QGA_STATE_RELATIVE_DIR  "run"
  49 #else
  50 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
  51 #define QGA_STATE_RELATIVE_DIR  "qemu-ga"
  52 #define QGA_SERIAL_PATH_DEFAULT "COM1"
  53 #endif
  54 #ifdef CONFIG_FSFREEZE
  55 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
  56 #endif
  57 #define QGA_SENTINEL_BYTE 0xFF
  58 #define QGA_CONF_DEFAULT CONFIG_QEMU_CONFDIR G_DIR_SEPARATOR_S "qemu-ga.conf"
  59 #define QGA_RETRY_INTERVAL 5
  60
  61 static struct {
  62     const char *state_dir;
  63     const char *pidfile;
  64 } dfl_pathnames;
  65
  66 typedef struct GAPersistentState {
  67 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
  68     int64_t fd_counter;
  69 } GAPersistentState;
  70
  71 typedef struct GAConfig GAConfig;
  72
  73 struct GAState {
  74     JSONMessageParser parser;
  75     GMainLoop *main_loop;
  76     GAChannel *channel;
  77     bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
  78     GACommandState *command_state;
  79     GLogLevelFlags log_level;
  80     FILE *log_file;
  81     bool logging_enabled;
  82 #ifdef _WIN32
  83     GAService service;
  84     HANDLE wakeup_event;
  85     HANDLE event_log;
  86 #endif
  87     bool delimit_response;
  88     bool frozen;
  89     GList *blockedrpcs;
  90     char *state_filepath_isfrozen;
  91     struct {
  92         const char *log_filepath;
  93         const char *pid_filepath;
  94     } deferred_options;
  95 #ifdef CONFIG_FSFREEZE
  96     const char *fsfreeze_hook;
  97 #endif
  98     gchar *pstate_filepath;
  99     GAPersistentState pstate;
 100     GAConfig *config;
 101     int socket_activation;
 102     bool force_exit;
 103 };
 104
 105 struct GAState *ga_state;
 106 QmpCommandList ga_commands;
 107
 108 /* commands that are safe to issue while filesystems are frozen */
 109 static const char *ga_freeze_allowlist[] = {
 110     "guest-ping",
 111     "guest-info",
 112     "guest-sync",
 113     "guest-sync-delimited",
 114     "guest-fsfreeze-status",
 115     "guest-fsfreeze-thaw",
 116     NULL
 117 };
 118
 119 #ifdef _WIN32
 120 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 121                                   LPVOID ctx);
 122 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data);
 123 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
 124 #endif
 125 static int run_agent(GAState *s);
 126 static void stop_agent(GAState *s, bool requested);
 127
 128 static void
 129 init_dfl_pathnames(void)
 130 {
 131     g_autofree char *state = qemu_get_local_state_dir();
 132
 133     g_assert(dfl_pathnames.state_dir == NULL);
 134     g_assert(dfl_pathnames.pidfile == NULL);
 135     dfl_pathnames.state_dir = g_build_filename(state, QGA_STATE_RELATIVE_DIR, NULL);
 136     dfl_pathnames.pidfile = g_build_filename(state, QGA_STATE_RELATIVE_DIR, "qemu-ga.pid", NULL);
 137 }
 138
 139 static void quit_handler(int sig)
 140 {
 141     /* if we're frozen, don't exit unless we're absolutely forced to,
 142      * because it's basically impossible for graceful exit to complete
 143      * unless all log/pid files are on unfreezable filesystems. there's
 144      * also a very likely chance killing the agent before unfreezing
 145      * the filesystems is a mistake (or will be viewed as one later).
 146      * On Windows the freeze interval is limited to 10 seconds, so
 147      * we should quit, but first we should wait for the timeout, thaw
 148      * the filesystem and quit.
 149      */
 150     if (ga_is_frozen(ga_state)) {
 151 #ifdef _WIN32
 152         int i = 0;
 153         Error *err = NULL;
 154         HANDLE hEventTimeout;
 155
 156         g_debug("Thawing filesystems before exiting");
 157
 158         hEventTimeout = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_TIMEOUT);
 159         if (hEventTimeout) {
 160             WaitForSingleObject(hEventTimeout, 0);
 161             CloseHandle(hEventTimeout);
 162         }
 163         qga_vss_fsfreeze(&i, false, NULL, &err);
 164         if (err) {
 165             g_debug("Error unfreezing filesystems prior to exiting: %s",
 166                 error_get_pretty(err));
 167             error_free(err);
 168         }
 169 #else
 170         return;
 171 #endif
 172     }
 173     g_debug("received signal num %d, quitting", sig);
 174
 175     stop_agent(ga_state, true);
 176 }
 177
 178 #ifndef _WIN32
 179 static gboolean register_signal_handlers(void)
 180 {
 181     struct sigaction sigact;
 182     int ret;
 183
 184     memset(&sigact, 0, sizeof(struct sigaction));
 185     sigact.sa_handler = quit_handler;
 186
 187     ret = sigaction(SIGINT, &sigact, NULL);
 188     if (ret == -1) {
 189         g_error("error configuring signal handler: %s", strerror(errno));
 190     }
 191     ret = sigaction(SIGTERM, &sigact, NULL);
 192     if (ret == -1) {
 193         g_error("error configuring signal handler: %s", strerror(errno));
 194     }
 195
 196     sigact.sa_handler = SIG_IGN;
 197     if (sigaction(SIGPIPE, &sigact, NULL) != 0) {
 198         g_error("error configuring SIGPIPE signal handler: %s",
 199                 strerror(errno));
 200     }
 201
 202     return true;
 203 }
 204
 205 /* TODO: use this in place of all post-fork() fclose(std*) callers */
 206 void reopen_fd_to_null(int fd)
 207 {
 208     int nullfd;
 209
 210     nullfd = open("/dev/null", O_RDWR);
 211     if (nullfd < 0) {
 212         return;
 213     }
 214
 215     dup2(nullfd, fd);
 216
 217     if (nullfd != fd) {
 218         close(nullfd);
 219     }
 220 }
 221 #endif
 222
 223 static void usage(const char *cmd)
 224 {
 225 #ifdef CONFIG_FSFREEZE
 226     g_autofree char *fsfreeze_hook = get_relocated_path(QGA_FSFREEZE_HOOK_DEFAULT);
 227 #endif
 228
 229     printf(
 230 "Usage: %s [-m <method> -p <path>] [<options>]\n"
 231 "QEMU Guest Agent " QEMU_FULL_VERSION "\n"
 232 QEMU_COPYRIGHT "\n"
 233 "\n"
 234 "  -m, --method      transport method: one of unix-listen, virtio-serial,\n"
 235 "                    isa-serial, or vsock-listen (virtio-serial is the default)\n"
 236 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
 237 "                    %s,\n"
 238 "                    the default for isa-serial is:\n"
 239 "                    %s).\n"
 240 "                    Socket addresses for vsock-listen are written as\n"
 241 "                    <cid>:<port>.\n"
 242 "  -l, --logfile     set logfile path, logs to stderr by default\n"
 243 "  -f, --pidfile     specify pidfile (default is %s)\n"
 244 #ifdef CONFIG_FSFREEZE
 245 "  -F, --fsfreeze-hook\n"
 246 "                    enable fsfreeze hook. Accepts an optional argument that\n"
 247 "                    specifies script to run on freeze/thaw. Script will be\n"
 248 "                    called with 'freeze'/'thaw' arguments accordingly.\n"
 249 "                    (default is %s)\n"
 250 "                    If using -F with an argument, do not follow -F with a\n"
 251 "                    space.\n"
 252 "                    (for example: -F/var/run/fsfreezehook.sh)\n"
 253 #endif
 254 "  -t, --statedir    specify dir to store state information (absolute paths\n"
 255 "                    only, default is %s)\n"
 256 "  -v, --verbose     log extra debugging information\n"
 257 "  -V, --version     print version information and exit\n"
 258 "  -d, --daemonize   become a daemon\n"
 259 #ifdef _WIN32
 260 "  -s, --service     service commands: install, uninstall, vss-install, vss-uninstall\n"
 261 #endif
 262 "  -b, --block-rpcs  comma-separated list of RPCs to disable (no spaces,\n"
 263 "                    use \"help\" to list available RPCs)\n"
 264 "  -D, --dump-conf   dump a qemu-ga config file based on current config\n"
 265 "                    options / command-line parameters to stdout\n"
 266 "  -r, --retry-path  attempt re-opening path if it's unavailable or closed\n"
 267 "                    due to an error which may be recoverable in the future\n"
 268 "                    (virtio-serial driver re-install, serial device hot\n"
 269 "                    plug/unplug, etc.)\n"
 270 "  -h, --help        display this help and exit\n"
 271 "\n"
 272 QEMU_HELP_BOTTOM "\n"
 273     , cmd, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT,
 274     dfl_pathnames.pidfile,
 275 #ifdef CONFIG_FSFREEZE
 276     fsfreeze_hook,
 277 #endif
 278     dfl_pathnames.state_dir);
 279 }
 280
 281 static const char *ga_log_level_str(GLogLevelFlags level)
 282 {
 283     switch (level & G_LOG_LEVEL_MASK) {
 284     case G_LOG_LEVEL_ERROR:
 285         return "error";
 286     case G_LOG_LEVEL_CRITICAL:
 287         return "critical";
 288     case G_LOG_LEVEL_WARNING:
 289         return "warning";
 290     case G_LOG_LEVEL_MESSAGE:
 291         return "message";
 292     case G_LOG_LEVEL_INFO:
 293         return "info";
 294     case G_LOG_LEVEL_DEBUG:
 295         return "debug";
 296     default:
 297         return "user";
 298     }
 299 }
 300
 301 bool ga_logging_enabled(GAState *s)
 302 {
 303     return s->logging_enabled;
 304 }
 305
 306 void ga_disable_logging(GAState *s)
 307 {
 308     s->logging_enabled = false;
 309 }
 310
 311 void ga_enable_logging(GAState *s)
 312 {
 313     s->logging_enabled = true;
 314 }
 315
 316 static int glib_log_level_to_system(int level)
 317 {
 318     switch (level) {
 319 #ifndef _WIN32
 320     case G_LOG_LEVEL_ERROR:
 321         return LOG_ERR;
 322     case G_LOG_LEVEL_CRITICAL:
 323         return LOG_CRIT;
 324     case G_LOG_LEVEL_WARNING:
 325         return LOG_WARNING;
 326     case G_LOG_LEVEL_MESSAGE:
 327         return LOG_NOTICE;
 328     case G_LOG_LEVEL_DEBUG:
 329         return LOG_DEBUG;
 330     case G_LOG_LEVEL_INFO:
 331     default:
 332         return LOG_INFO;
 333 #else
 334     case G_LOG_LEVEL_ERROR:
 335     case G_LOG_LEVEL_CRITICAL:
 336         return EVENTLOG_ERROR_TYPE;
 337     case G_LOG_LEVEL_WARNING:
 338         return EVENTLOG_WARNING_TYPE;
 339     case G_LOG_LEVEL_MESSAGE:
 340     case G_LOG_LEVEL_INFO:
 341     case G_LOG_LEVEL_DEBUG:
 342     default:
 343         return EVENTLOG_INFORMATION_TYPE;
 344 #endif
 345     }
 346 }
 347
 348 static void ga_log(const gchar *domain, GLogLevelFlags level,
 349                    const gchar *msg, gpointer opaque)
 350 {
 351     GAState *s = opaque;
 352     const char *level_str = ga_log_level_str(level);
 353
 354     if (!ga_logging_enabled(s)) {
 355         return;
 356     }
 357
 358     level &= G_LOG_LEVEL_MASK;
 359     if (g_strcmp0(domain, "syslog") == 0) {
 360 #ifndef _WIN32
 361         syslog(glib_log_level_to_system(level), "%s: %s", level_str, msg);
 362 #else
 363         ReportEvent(s->event_log, glib_log_level_to_system(level),
 364                     0, 1, NULL, 1, 0, &msg, NULL);
 365 #endif
 366     } else if (level & s->log_level) {
 367         g_autoptr(GDateTime) now = g_date_time_new_now_utc();
 368         g_autofree char *nowstr = g_date_time_format(now, "%s.%f");
 369         fprintf(s->log_file, "%s: %s: %s\n", nowstr, level_str, msg);
 370         fflush(s->log_file);
 371     }
 372 }
 373
 374 void ga_set_response_delimited(GAState *s)
 375 {
 376     s->delimit_response = true;
 377 }
 378
 379 static FILE *ga_open_logfile(const char *logfile)
 380 {
 381     FILE *f;
 382
 383     f = fopen(logfile, "a");
 384     if (!f) {
 385         return NULL;
 386     }
 387
 388     qemu_set_cloexec(fileno(f));
 389     return f;
 390 }
 391
 392 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
 393 {
 394     return strcmp(str1, str2);
 395 }
 396
 397 /* disable commands that aren't safe for fsfreeze */
 398 static void ga_disable_not_allowed(const QmpCommand *cmd, void *opaque)
 399 {
 400     bool allowed = false;
 401     int i = 0;
 402     const char *name = qmp_command_name(cmd);
 403
 404     while (ga_freeze_allowlist[i] != NULL) {
 405         if (strcmp(name, ga_freeze_allowlist[i]) == 0) {
 406             allowed = true;
 407         }
 408         i++;
 409     }
 410     if (!allowed) {
 411         g_debug("disabling command: %s", name);
 412         qmp_disable_command(&ga_commands, name, "the agent is in frozen state");
 413     }
 414 }
 415
 416 /* [re-]enable all commands, except those explicitly blocked by user */
 417 static void ga_enable_non_blocked(const QmpCommand *cmd, void *opaque)
 418 {
 419     GList *blockedrpcs = opaque;
 420     const char *name = qmp_command_name(cmd);
 421
 422     if (g_list_find_custom(blockedrpcs, name, ga_strcmp) == NULL &&
 423         !qmp_command_is_enabled(cmd)) {
 424         g_debug("enabling command: %s", name);
 425         qmp_enable_command(&ga_commands, name);
 426     }
 427 }
 428
 429 static bool ga_create_file(const char *path)
 430 {
 431     int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
 432     if (fd == -1) {
 433         g_warning("unable to open/create file %s: %s", path, strerror(errno));
 434         return false;
 435     }
 436     close(fd);
 437     return true;
 438 }
 439
 440 static bool ga_delete_file(const char *path)
 441 {
 442     int ret = unlink(path);
 443     if (ret == -1) {
 444         g_warning("unable to delete file: %s: %s", path, strerror(errno));
 445         return false;
 446     }
 447
 448     return true;
 449 }
 450
 451 bool ga_is_frozen(GAState *s)
 452 {
 453     return s->frozen;
 454 }
 455
 456 void ga_set_frozen(GAState *s)
 457 {
 458     if (ga_is_frozen(s)) {
 459         return;
 460     }
 461     /* disable all forbidden (for frozen state) commands */
 462     qmp_for_each_command(&ga_commands, ga_disable_not_allowed, NULL);
 463     g_warning("disabling logging due to filesystem freeze");
 464     ga_disable_logging(s);
 465     s->frozen = true;
 466     if (!ga_create_file(s->state_filepath_isfrozen)) {
 467         g_warning("unable to create %s, fsfreeze may not function properly",
 468                   s->state_filepath_isfrozen);
 469     }
 470 }
 471
 472 void ga_unset_frozen(GAState *s)
 473 {
 474     if (!ga_is_frozen(s)) {
 475         return;
 476     }
 477
 478     /* if we delayed creation/opening of pid/log files due to being
 479      * in a frozen state at start up, do it now
 480      */
 481     if (s->deferred_options.log_filepath) {
 482         s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
 483         if (!s->log_file) {
 484             s->log_file = stderr;
 485         }
 486         s->deferred_options.log_filepath = NULL;
 487     }
 488     ga_enable_logging(s);
 489     g_warning("logging re-enabled due to filesystem unfreeze");
 490     if (s->deferred_options.pid_filepath) {
 491         Error *err = NULL;
 492
 493         if (!qemu_write_pidfile(s->deferred_options.pid_filepath, &err)) {
 494             g_warning("%s", error_get_pretty(err));
 495             error_free(err);
 496         }
 497         s->deferred_options.pid_filepath = NULL;
 498     }
 499
 500     /* enable all disabled, non-blocked commands */
 501     qmp_for_each_command(&ga_commands, ga_enable_non_blocked, s->blockedrpcs);
 502     s->frozen = false;
 503     if (!ga_delete_file(s->state_filepath_isfrozen)) {
 504         g_warning("unable to delete %s, fsfreeze may not function properly",
 505                   s->state_filepath_isfrozen);
 506     }
 507 }
 508
 509 #ifdef CONFIG_FSFREEZE
 510 const char *ga_fsfreeze_hook(GAState *s)
 511 {
 512     return s->fsfreeze_hook;
 513 }
 514 #endif
 515
 516 static void become_daemon(const char *pidfile)
 517 {
 518 #ifndef _WIN32
 519     pid_t pid, sid;
 520
 521     pid = fork();
 522     if (pid < 0) {
 523         exit(EXIT_FAILURE);
 524     }
 525     if (pid > 0) {
 526         exit(EXIT_SUCCESS);
 527     }
 528
 529     if (pidfile) {
 530         Error *err = NULL;
 531
 532         if (!qemu_write_pidfile(pidfile, &err)) {
 533             g_critical("%s", error_get_pretty(err));
 534             error_free(err);
 535             exit(EXIT_FAILURE);
 536         }
 537     }
 538
 539     umask(S_IRWXG | S_IRWXO);
 540     sid = setsid();
 541     if (sid < 0) {
 542         goto fail;
 543     }
 544     if ((chdir("/")) < 0) {
 545         goto fail;
 546     }
 547
 548     reopen_fd_to_null(STDIN_FILENO);
 549     reopen_fd_to_null(STDOUT_FILENO);
 550     reopen_fd_to_null(STDERR_FILENO);
 551     return;
 552
 553 fail:
 554     if (pidfile) {
 555         unlink(pidfile);
 556     }
 557     g_critical("failed to daemonize");
 558     exit(EXIT_FAILURE);
 559 #endif
 560 }
 561
 562 static int send_response(GAState *s, const QDict *rsp)
 563 {
 564     GString *response;
 565     GIOStatus status;
 566
 567     g_assert(s->channel);
 568
 569     if (!rsp) {
 570         return 0;
 571     }
 572
 573     response = qobject_to_json(QOBJECT(rsp));
 574     if (!response) {
 575         return -EINVAL;
 576     }
 577
 578     if (s->delimit_response) {
 579         s->delimit_response = false;
 580         g_string_prepend_c(response, QGA_SENTINEL_BYTE);
 581     }
 582
 583     g_string_append_c(response, '\n');
 584     status = ga_channel_write_all(s->channel, response->str, response->len);
 585     g_string_free(response, true);
 586     if (status != G_IO_STATUS_NORMAL) {
 587         return -EIO;
 588     }
 589
 590     return 0;
 591 }
 592
 593 /* handle requests/control events coming in over the channel */
 594 static void process_event(void *opaque, QObject *obj, Error *err)
 595 {
 596     GAState *s = opaque;
 597     QDict *rsp;
 598     int ret;
 599
 600     g_debug("process_event: called");
 601     assert(!obj != !err);
 602     if (err) {
 603         rsp = qmp_error_response(err);
 604         goto end;
 605     }
 606
 607     g_debug("processing command");
 608     rsp = qmp_dispatch(&ga_commands, obj, false, NULL);
 609
 610 end:
 611     ret = send_response(s, rsp);
 612     if (ret < 0) {
 613         g_warning("error sending error response: %s", strerror(-ret));
 614     }
 615     qobject_unref(rsp);
 616     qobject_unref(obj);
 617 }
 618
 619 /* false return signals GAChannel to close the current client connection */
 620 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 621 {
 622     GAState *s = data;
 623     gchar buf[QGA_READ_COUNT_DEFAULT + 1];
 624     gsize count;
 625     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 626     switch (status) {
 627     case G_IO_STATUS_ERROR:
 628         g_warning("error reading channel");
 629         stop_agent(s, false);
 630         return false;
 631     case G_IO_STATUS_NORMAL:
 632         buf[count] = 0;
 633         g_debug("read data, count: %d, data: %s", (int)count, buf);
 634         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 635         break;
 636     case G_IO_STATUS_EOF:
 637         g_debug("received EOF");
 638         if (!s->virtio) {
 639             return false;
 640         }
 641         /* fall through */
 642     case G_IO_STATUS_AGAIN:
 643         /* virtio causes us to spin here when no process is attached to
 644          * host-side chardev. sleep a bit to mitigate this
 645          */
 646         if (s->virtio) {
 647             g_usleep(G_USEC_PER_SEC / 10);
 648         }
 649         return true;
 650     default:
 651         g_warning("unknown channel read status, closing");
 652         return false;
 653     }
 654     return true;
 655 }
 656
 657 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path,
 658                              int listen_fd)
 659 {
 660     GAChannelMethod channel_method;
 661
 662     if (strcmp(method, "virtio-serial") == 0) {
 663         s->virtio = true; /* virtio requires special handling in some cases */
 664         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 665     } else if (strcmp(method, "isa-serial") == 0) {
 666         channel_method = GA_CHANNEL_ISA_SERIAL;
 667     } else if (strcmp(method, "unix-listen") == 0) {
 668         channel_method = GA_CHANNEL_UNIX_LISTEN;
 669     } else if (strcmp(method, "vsock-listen") == 0) {
 670         channel_method = GA_CHANNEL_VSOCK_LISTEN;
 671     } else {
 672         g_critical("unsupported channel method/type: %s", method);
 673         return false;
 674     }
 675
 676     s->channel = ga_channel_new(channel_method, path, listen_fd,
 677                                 channel_event_cb, s);
 678     if (!s->channel) {
 679         g_critical("failed to create guest agent channel");
 680         return false;
 681     }
 682
 683     return true;
 684 }
 685
 686 #ifdef _WIN32
 687 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data)
 688 {
 689     DWORD ret = NO_ERROR;
 690     PDEV_BROADCAST_HDR broadcast_header = (PDEV_BROADCAST_HDR)data;
 691
 692     if (broadcast_header->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE) {
 693         switch (type) {
 694             /* Device inserted */
 695         case DBT_DEVICEARRIVAL:
 696             /* Start QEMU-ga's service */
 697             if (!SetEvent(ga_state->wakeup_event)) {
 698                 ret = GetLastError();
 699             }
 700             break;
 701             /* Device removed */
 702         case DBT_DEVICEQUERYREMOVE:
 703         case DBT_DEVICEREMOVEPENDING:
 704         case DBT_DEVICEREMOVECOMPLETE:
 705             /* Stop QEMU-ga's service */
 706             if (!ResetEvent(ga_state->wakeup_event)) {
 707                 ret = GetLastError();
 708             }
 709             break;
 710         default:
 711             ret = ERROR_CALL_NOT_IMPLEMENTED;
 712         }
 713     }
 714     return ret;
 715 }
 716
 717 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 718                                   LPVOID ctx)
 719 {
 720     DWORD ret = NO_ERROR;
 721     GAService *service = &ga_state->service;
 722
 723     switch (ctrl) {
 724     case SERVICE_CONTROL_STOP:
 725     case SERVICE_CONTROL_SHUTDOWN:
 726         quit_handler(SIGTERM);
 727         SetEvent(ga_state->wakeup_event);
 728         service->status.dwCurrentState = SERVICE_STOP_PENDING;
 729         SetServiceStatus(service->status_handle, &service->status);
 730         break;
 731     case SERVICE_CONTROL_DEVICEEVENT:
 732         handle_serial_device_events(type, data);
 733         break;
 734
 735     default:
 736         ret = ERROR_CALL_NOT_IMPLEMENTED;
 737     }
 738     return ret;
 739 }
 740
 741 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 742 {
 743     GAService *service = &ga_state->service;
 744
 745     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 746         service_ctrl_handler, NULL);
 747
 748     if (service->status_handle == 0) {
 749         g_critical("Failed to register extended requests function!\n");
 750         return;
 751     }
 752
 753     service->status.dwServiceType = SERVICE_WIN32;
 754     service->status.dwCurrentState = SERVICE_RUNNING;
 755     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 756     service->status.dwWin32ExitCode = NO_ERROR;
 757     service->status.dwServiceSpecificExitCode = NO_ERROR;
 758     service->status.dwCheckPoint = 0;
 759     service->status.dwWaitHint = 0;
 760     DEV_BROADCAST_DEVICEINTERFACE notification_filter;
 761     ZeroMemory(&notification_filter, sizeof(notification_filter));
 762     notification_filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
 763     notification_filter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
 764     notification_filter.dbcc_classguid = GUID_VIOSERIAL_PORT;
 765
 766     service->device_notification_handle =
 767         RegisterDeviceNotification(service->status_handle,
 768             &notification_filter, DEVICE_NOTIFY_SERVICE_HANDLE);
 769     if (!service->device_notification_handle) {
 770         g_critical("Failed to register device notification handle!\n");
 771         return;
 772     }
 773     SetServiceStatus(service->status_handle, &service->status);
 774
 775     run_agent(ga_state);
 776
 777     UnregisterDeviceNotification(service->device_notification_handle);
 778     service->status.dwCurrentState = SERVICE_STOPPED;
 779     SetServiceStatus(service->status_handle, &service->status);
 780 }
 781 #endif
 782
 783 static void set_persistent_state_defaults(GAPersistentState *pstate)
 784 {
 785     g_assert(pstate);
 786     pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
 787 }
 788
 789 static void persistent_state_from_keyfile(GAPersistentState *pstate,
 790                                           GKeyFile *keyfile)
 791 {
 792     g_assert(pstate);
 793     g_assert(keyfile);
 794     /* if any fields are missing, either because the file was tampered with
 795      * by agents of chaos, or because the field wasn't present at the time the
 796      * file was created, the best we can ever do is start over with the default
 797      * values. so load them now, and ignore any errors in accessing key-value
 798      * pairs
 799      */
 800     set_persistent_state_defaults(pstate);
 801
 802     if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
 803         pstate->fd_counter =
 804             g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
 805     }
 806 }
 807
 808 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
 809                                         GKeyFile *keyfile)
 810 {
 811     g_assert(pstate);
 812     g_assert(keyfile);
 813
 814     g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
 815 }
 816
 817 static gboolean write_persistent_state(const GAPersistentState *pstate,
 818                                        const gchar *path)
 819 {
 820     GKeyFile *keyfile = g_key_file_new();
 821     GError *gerr = NULL;
 822     gboolean ret = true;
 823     gchar *data = NULL;
 824     gsize data_len;
 825
 826     g_assert(pstate);
 827
 828     persistent_state_to_keyfile(pstate, keyfile);
 829     data = g_key_file_to_data(keyfile, &data_len, &gerr);
 830     if (gerr) {
 831         g_critical("failed to convert persistent state to string: %s",
 832                    gerr->message);
 833         ret = false;
 834         goto out;
 835     }
 836
 837     g_file_set_contents(path, data, data_len, &gerr);
 838     if (gerr) {
 839         g_critical("failed to write persistent state to %s: %s",
 840                     path, gerr->message);
 841         ret = false;
 842         goto out;
 843     }
 844
 845 out:
 846     if (gerr) {
 847         g_error_free(gerr);
 848     }
 849     if (keyfile) {
 850         g_key_file_free(keyfile);
 851     }
 852     g_free(data);
 853     return ret;
 854 }
 855
 856 static gboolean read_persistent_state(GAPersistentState *pstate,
 857                                       const gchar *path, gboolean frozen)
 858 {
 859     GKeyFile *keyfile = NULL;
 860     GError *gerr = NULL;
 861     struct stat st;
 862     gboolean ret = true;
 863
 864     g_assert(pstate);
 865
 866     if (stat(path, &st) == -1) {
 867         /* it's okay if state file doesn't exist, but any other error
 868          * indicates a permissions issue or some other misconfiguration
 869          * that we likely won't be able to recover from.
 870          */
 871         if (errno != ENOENT) {
 872             g_critical("unable to access state file at path %s: %s",
 873                        path, strerror(errno));
 874             ret = false;
 875             goto out;
 876         }
 877
 878         /* file doesn't exist. initialize state to default values and
 879          * attempt to save now. (we could wait till later when we have
 880          * modified state we need to commit, but if there's a problem,
 881          * such as a missing parent directory, we want to catch it now)
 882          *
 883          * there is a potential scenario where someone either managed to
 884          * update the agent from a version that didn't use a key store
 885          * while qemu-ga thought the filesystem was frozen, or
 886          * deleted the key store prior to issuing a fsfreeze, prior
 887          * to restarting the agent. in this case we go ahead and defer
 888          * initial creation till we actually have modified state to
 889          * write, otherwise fail to recover from freeze.
 890          */
 891         set_persistent_state_defaults(pstate);
 892         if (!frozen) {
 893             ret = write_persistent_state(pstate, path);
 894             if (!ret) {
 895                 g_critical("unable to create state file at path %s", path);
 896                 ret = false;
 897                 goto out;
 898             }
 899         }
 900         ret = true;
 901         goto out;
 902     }
 903
 904     keyfile = g_key_file_new();
 905     g_key_file_load_from_file(keyfile, path, 0, &gerr);
 906     if (gerr) {
 907         g_critical("error loading persistent state from path: %s, %s",
 908                    path, gerr->message);
 909         ret = false;
 910         goto out;
 911     }
 912
 913     persistent_state_from_keyfile(pstate, keyfile);
 914
 915 out:
 916     if (keyfile) {
 917         g_key_file_free(keyfile);
 918     }
 919     if (gerr) {
 920         g_error_free(gerr);
 921     }
 922
 923     return ret;
 924 }
 925
 926 int64_t ga_get_fd_handle(GAState *s, Error **errp)
 927 {
 928     int64_t handle;
 929
 930     g_assert(s->pstate_filepath);
 931     /*
 932      * We block commands and avoid operations that potentially require
 933      * writing to disk when we're in a frozen state. this includes opening
 934      * new files, so we should never get here in that situation
 935      */
 936     g_assert(!ga_is_frozen(s));
 937
 938     handle = s->pstate.fd_counter++;
 939
 940     /* This should never happen on a reasonable timeframe, as guest-file-open
 941      * would have to be issued 2^63 times */
 942     if (s->pstate.fd_counter == INT64_MAX) {
 943         abort();
 944     }
 945
 946     if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
 947         error_setg(errp, "failed to commit persistent state to disk");
 948         return -1;
 949     }
 950
 951     return handle;
 952 }
 953
 954 static void ga_print_cmd(const QmpCommand *cmd, void *opaque)
 955 {
 956     printf("%s\n", qmp_command_name(cmd));
 957 }
 958
 959 static GList *split_list(const gchar *str, const gchar *delim)
 960 {
 961     GList *list = NULL;
 962     int i;
 963     gchar **strv;
 964
 965     strv = g_strsplit(str, delim, -1);
 966     for (i = 0; strv[i]; i++) {
 967         list = g_list_prepend(list, strv[i]);
 968     }
 969     g_free(strv);
 970
 971     return list;
 972 }
 973
 974 struct GAConfig {
 975     char *channel_path;
 976     char *method;
 977     char *log_filepath;
 978     char *pid_filepath;
 979 #ifdef CONFIG_FSFREEZE
 980     char *fsfreeze_hook;
 981 #endif
 982     char *state_dir;
 983 #ifdef _WIN32
 984     const char *service;
 985 #endif
 986     gchar *bliststr; /* blockedrpcs may point to this string */
 987     GList *blockedrpcs;
 988     int daemonize;
 989     GLogLevelFlags log_level;
 990     int dumpconf;
 991     bool retry_path;
 992 };
 993
 994 static void config_load(GAConfig *config)
 995 {
 996     GError *gerr = NULL;
 997     GKeyFile *keyfile;
 998     g_autofree char *conf = g_strdup(g_getenv("QGA_CONF")) ?: get_relocated_path(QGA_CONF_DEFAULT);
 999     const gchar *blockrpcs_key = "block-rpcs";
1000
1001     /* read system config */
1002     keyfile = g_key_file_new();
1003     if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
1004         goto end;
1005     }
1006     if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
1007         config->daemonize =
1008             g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
1009     }
1010     if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
1011         config->method =
1012             g_key_file_get_string(keyfile, "general", "method", &gerr);
1013     }
1014     if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
1015         config->channel_path =
1016             g_key_file_get_string(keyfile, "general", "path", &gerr);
1017     }
1018     if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
1019         config->log_filepath =
1020             g_key_file_get_string(keyfile, "general", "logfile", &gerr);
1021     }
1022     if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
1023         config->pid_filepath =
1024             g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
1025     }
1026 #ifdef CONFIG_FSFREEZE
1027     if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
1028         config->fsfreeze_hook =
1029             g_key_file_get_string(keyfile,
1030                                   "general", "fsfreeze-hook", &gerr);
1031     }
1032 #endif
1033     if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
1034         config->state_dir =
1035             g_key_file_get_string(keyfile, "general", "statedir", &gerr);
1036     }
1037     if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
1038         g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
1039         /* enable all log levels */
1040         config->log_level = G_LOG_LEVEL_MASK;
1041     }
1042     if (g_key_file_has_key(keyfile, "general", "retry-path", NULL)) {
1043         config->retry_path =
1044             g_key_file_get_boolean(keyfile, "general", "retry-path", &gerr);
1045     }
1046
1047     if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
1048         g_warning("config using deprecated 'blacklist' key, should be replaced"
1049                   " with the 'block-rpcs' key.");
1050         blockrpcs_key = "blacklist";
1051     }
1052     if (g_key_file_has_key(keyfile, "general", blockrpcs_key, NULL)) {
1053         config->bliststr =
1054             g_key_file_get_string(keyfile, "general", blockrpcs_key, &gerr);
1055         config->blockedrpcs = g_list_concat(config->blockedrpcs,
1056                                           split_list(config->bliststr, ","));
1057     }
1058
1059 end:
1060     g_key_file_free(keyfile);
1061     if (gerr &&
1062         !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
1063         g_critical("error loading configuration from path: %s, %s",
1064                    conf, gerr->message);
1065         exit(EXIT_FAILURE);
1066     }
1067     g_clear_error(&gerr);
1068 }
1069
1070 static gchar *list_join(GList *list, const gchar separator)
1071 {
1072     GString *str = g_string_new("");
1073
1074     while (list) {
1075         str = g_string_append(str, (gchar *)list->data);
1076         list = g_list_next(list);
1077         if (list) {
1078             str = g_string_append_c(str, separator);
1079         }
1080     }
1081
1082     return g_string_free(str, FALSE);
1083 }
1084
1085 static void config_dump(GAConfig *config)
1086 {
1087     GError *error = NULL;
1088     GKeyFile *keyfile;
1089     gchar *tmp;
1090
1091     keyfile = g_key_file_new();
1092     g_assert(keyfile);
1093
1094     g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1095     g_key_file_set_string(keyfile, "general", "method", config->method);
1096     if (config->channel_path) {
1097         g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1098     }
1099     if (config->log_filepath) {
1100         g_key_file_set_string(keyfile, "general", "logfile",
1101                               config->log_filepath);
1102     }
1103     g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1104 #ifdef CONFIG_FSFREEZE
1105     if (config->fsfreeze_hook) {
1106         g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1107                               config->fsfreeze_hook);
1108     }
1109 #endif
1110     g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1111     g_key_file_set_boolean(keyfile, "general", "verbose",
1112                            config->log_level == G_LOG_LEVEL_MASK);
1113     g_key_file_set_boolean(keyfile, "general", "retry-path",
1114                            config->retry_path);
1115     tmp = list_join(config->blockedrpcs, ',');
1116     g_key_file_set_string(keyfile, "general", "block-rpcs", tmp);
1117     g_free(tmp);
1118
1119     tmp = g_key_file_to_data(keyfile, NULL, &error);
1120     if (error) {
1121         g_critical("Failed to dump keyfile: %s", error->message);
1122         g_clear_error(&error);
1123     } else {
1124         printf("%s", tmp);
1125     }
1126
1127     g_free(tmp);
1128     g_key_file_free(keyfile);
1129 }
1130
1131 static void config_parse(GAConfig *config, int argc, char **argv)
1132 {
1133     const char *sopt = "hVvdm:p:l:f:F::b:s:t:Dr";
1134     int opt_ind = 0, ch;
1135     const struct option lopt[] = {
1136         { "help", 0, NULL, 'h' },
1137         { "version", 0, NULL, 'V' },
1138         { "dump-conf", 0, NULL, 'D' },
1139         { "logfile", 1, NULL, 'l' },
1140         { "pidfile", 1, NULL, 'f' },
1141 #ifdef CONFIG_FSFREEZE
1142         { "fsfreeze-hook", 2, NULL, 'F' },
1143 #endif
1144         { "verbose", 0, NULL, 'v' },
1145         { "method", 1, NULL, 'm' },
1146         { "path", 1, NULL, 'p' },
1147         { "daemonize", 0, NULL, 'd' },
1148         { "block-rpcs", 1, NULL, 'b' },
1149         { "blacklist", 1, NULL, 'b' },  /* deprecated alias for 'block-rpcs' */
1150 #ifdef _WIN32
1151         { "service", 1, NULL, 's' },
1152 #endif
1153         { "statedir", 1, NULL, 't' },
1154         { "retry-path", 0, NULL, 'r' },
1155         { NULL, 0, NULL, 0 }
1156     };
1157
1158     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1159         switch (ch) {
1160         case 'm':
1161             g_free(config->method);
1162             config->method = g_strdup(optarg);
1163             break;
1164         case 'p':
1165             g_free(config->channel_path);
1166             config->channel_path = g_strdup(optarg);
1167             break;
1168         case 'l':
1169             g_free(config->log_filepath);
1170             config->log_filepath = g_strdup(optarg);
1171             break;
1172         case 'f':
1173             g_free(config->pid_filepath);
1174             config->pid_filepath = g_strdup(optarg);
1175             break;
1176 #ifdef CONFIG_FSFREEZE
1177         case 'F':
1178             g_free(config->fsfreeze_hook);
1179             config->fsfreeze_hook = optarg ? g_strdup(optarg) : get_relocated_path(QGA_FSFREEZE_HOOK_DEFAULT);
1180             break;
1181 #endif
1182         case 't':
1183             g_free(config->state_dir);
1184             config->state_dir = g_strdup(optarg);
1185             break;
1186         case 'v':
1187             /* enable all log levels */
1188             config->log_level = G_LOG_LEVEL_MASK;
1189             break;
1190         case 'V':
1191             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1192             exit(EXIT_SUCCESS);
1193         case 'd':
1194             config->daemonize = 1;
1195             break;
1196         case 'D':
1197             config->dumpconf = 1;
1198             break;
1199         case 'r':
1200             config->retry_path = true;
1201             break;
1202         case 'b': {
1203             if (is_help_option(optarg)) {
1204                 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1205                 exit(EXIT_SUCCESS);
1206             }
1207             config->blockedrpcs = g_list_concat(config->blockedrpcs,
1208                                                 split_list(optarg, ","));
1209             break;
1210         }
1211 #ifdef _WIN32
1212         case 's':
1213             config->service = optarg;
1214             if (strcmp(config->service, "install") == 0) {
1215                 if (ga_install_vss_provider()) {
1216                     exit(EXIT_FAILURE);
1217                 }
1218                 if (ga_install_service(config->channel_path,
1219                                        config->log_filepath, config->state_dir)) {
1220                     exit(EXIT_FAILURE);
1221                 }
1222                 exit(EXIT_SUCCESS);
1223             } else if (strcmp(config->service, "uninstall") == 0) {
1224                 ga_uninstall_vss_provider();
1225                 exit(ga_uninstall_service());
1226             } else if (strcmp(config->service, "vss-install") == 0) {
1227                 if (ga_install_vss_provider()) {
1228                     exit(EXIT_FAILURE);
1229                 }
1230                 exit(EXIT_SUCCESS);
1231             } else if (strcmp(config->service, "vss-uninstall") == 0) {
1232                 ga_uninstall_vss_provider();
1233                 exit(EXIT_SUCCESS);
1234             } else {
1235                 printf("Unknown service command.\n");
1236                 exit(EXIT_FAILURE);
1237             }
1238             break;
1239 #endif
1240         case 'h':
1241             usage(argv[0]);
1242             exit(EXIT_SUCCESS);
1243         case '?':
1244             g_print("Unknown option, try '%s --help' for more information.\n",
1245                     argv[0]);
1246             exit(EXIT_FAILURE);
1247         }
1248     }
1249 }
1250
1251 static void config_free(GAConfig *config)
1252 {
1253     g_free(config->method);
1254     g_free(config->log_filepath);
1255     g_free(config->pid_filepath);
1256     g_free(config->state_dir);
1257     g_free(config->channel_path);
1258     g_free(config->bliststr);
1259 #ifdef CONFIG_FSFREEZE
1260     g_free(config->fsfreeze_hook);
1261 #endif
1262     g_list_free_full(config->blockedrpcs, g_free);
1263     g_free(config);
1264 }
1265
1266 static bool check_is_frozen(GAState *s)
1267 {
1268 #ifndef _WIN32
1269     /* check if a previous instance of qemu-ga exited with filesystems' state
1270      * marked as frozen. this could be a stale value (a non-qemu-ga process
1271      * or reboot may have since unfrozen them), but better to require an
1272      * uneeded unfreeze than to risk hanging on start-up
1273      */
1274     struct stat st;
1275     if (stat(s->state_filepath_isfrozen, &st) == -1) {
1276         /* it's okay if the file doesn't exist, but if we can't access for
1277          * some other reason, such as permissions, there's a configuration
1278          * that needs to be addressed. so just bail now before we get into
1279          * more trouble later
1280          */
1281         if (errno != ENOENT) {
1282             g_critical("unable to access state file at path %s: %s",
1283                        s->state_filepath_isfrozen, strerror(errno));
1284             return EXIT_FAILURE;
1285         }
1286     } else {
1287         g_warning("previous instance appears to have exited with frozen"
1288                   " filesystems. deferring logging/pidfile creation and"
1289                   " disabling non-fsfreeze-safe commands until"
1290                   " guest-fsfreeze-thaw is issued, or filesystems are"
1291                   " manually unfrozen and the file %s is removed",
1292                   s->state_filepath_isfrozen);
1293         return true;
1294     }
1295 #endif
1296     return false;
1297 }
1298
1299 static GAState *initialize_agent(GAConfig *config, int socket_activation)
1300 {
1301     GAState *s = g_new0(GAState, 1);
1302
1303     g_assert(ga_state == NULL);
1304
1305     s->log_level = config->log_level;
1306     s->log_file = stderr;
1307 #ifdef CONFIG_FSFREEZE
1308     s->fsfreeze_hook = config->fsfreeze_hook;
1309 #endif
1310     s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1311     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1312                                                  config->state_dir);
1313     s->frozen = check_is_frozen(s);
1314
1315     g_log_set_default_handler(ga_log, s);
1316     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1317     ga_enable_logging(s);
1318
1319     g_debug("Guest agent version %s started", QEMU_FULL_VERSION);
1320
1321 #ifdef _WIN32
1322     s->event_log = RegisterEventSource(NULL, "qemu-ga");
1323     if (!s->event_log) {
1324         g_autofree gchar *errmsg = g_win32_error_message(GetLastError());
1325         g_critical("unable to register event source: %s", errmsg);
1326         return NULL;
1327     }
1328
1329     /* On win32 the state directory is application specific (be it the default
1330      * or a user override). We got past the command line parsing; let's create
1331      * the directory (with any intermediate directories). If we run into an
1332      * error later on, we won't try to clean up the directory, it is considered
1333      * persistent.
1334      */
1335     if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1336         g_critical("unable to create (an ancestor of) the state directory"
1337                    " '%s': %s", config->state_dir, strerror(errno));
1338         return NULL;
1339     }
1340 #endif
1341
1342     if (ga_is_frozen(s)) {
1343         if (config->daemonize) {
1344             /* delay opening/locking of pidfile till filesystems are unfrozen */
1345             s->deferred_options.pid_filepath = config->pid_filepath;
1346             become_daemon(NULL);
1347         }
1348         if (config->log_filepath) {
1349             /* delay opening the log file till filesystems are unfrozen */
1350             s->deferred_options.log_filepath = config->log_filepath;
1351         }
1352         ga_disable_logging(s);
1353         qmp_for_each_command(&ga_commands, ga_disable_not_allowed, NULL);
1354     } else {
1355         if (config->daemonize) {
1356             become_daemon(config->pid_filepath);
1357         }
1358         if (config->log_filepath) {
1359             FILE *log_file = ga_open_logfile(config->log_filepath);
1360             if (!log_file) {
1361                 g_critical("unable to open specified log file: %s",
1362                            strerror(errno));
1363                 return NULL;
1364             }
1365             s->log_file = log_file;
1366         }
1367     }
1368
1369     /* load persistent state from disk */
1370     if (!read_persistent_state(&s->pstate,
1371                                s->pstate_filepath,
1372                                ga_is_frozen(s))) {
1373         g_critical("failed to load persistent state");
1374         return NULL;
1375     }
1376
1377     config->blockedrpcs = ga_command_init_blockedrpcs(config->blockedrpcs);
1378     if (config->blockedrpcs) {
1379         GList *l = config->blockedrpcs;
1380         s->blockedrpcs = config->blockedrpcs;
1381         do {
1382             g_debug("disabling command: %s", (char *)l->data);
1383             qmp_disable_command(&ga_commands, l->data, NULL);
1384             l = g_list_next(l);
1385         } while (l);
1386     }
1387     s->command_state = ga_command_state_new();
1388     ga_command_state_init(s, s->command_state);
1389     ga_command_state_init_all(s->command_state);
1390     json_message_parser_init(&s->parser, process_event, s, NULL);
1391
1392 #ifndef _WIN32
1393     if (!register_signal_handlers()) {
1394         g_critical("failed to register signal handlers");
1395         return NULL;
1396     }
1397 #endif
1398
1399     s->main_loop = g_main_loop_new(NULL, false);
1400
1401     s->config = config;
1402     s->socket_activation = socket_activation;
1403
1404 #ifdef _WIN32
1405     s->wakeup_event = CreateEvent(NULL, TRUE, FALSE, TEXT("WakeUp"));
1406     if (s->wakeup_event == NULL) {
1407         g_critical("CreateEvent failed");
1408         return NULL;
1409     }
1410 #endif
1411
1412     ga_state = s;
1413     return s;
1414 }
1415
1416 static void cleanup_agent(GAState *s)
1417 {
1418 #ifdef _WIN32
1419     CloseHandle(s->wakeup_event);
1420     CloseHandle(s->event_log);
1421 #endif
1422     if (s->command_state) {
1423         ga_command_state_cleanup_all(s->command_state);
1424         ga_command_state_free(s->command_state);
1425         json_message_parser_destroy(&s->parser);
1426     }
1427     g_free(s->pstate_filepath);
1428     g_free(s->state_filepath_isfrozen);
1429     if (s->main_loop) {
1430         g_main_loop_unref(s->main_loop);
1431     }
1432     g_free(s);
1433     ga_state = NULL;
1434 }
1435
1436 static int run_agent_once(GAState *s)
1437 {
1438     if (!channel_init(s, s->config->method, s->config->channel_path,
1439                       s->socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
1440         g_critical("failed to initialize guest agent channel");
1441         return EXIT_FAILURE;
1442     }
1443
1444     g_main_loop_run(ga_state->main_loop);
1445
1446     if (s->channel) {
1447         ga_channel_free(s->channel);
1448     }
1449
1450     return EXIT_SUCCESS;
1451 }
1452
1453 static void wait_for_channel_availability(GAState *s)
1454 {
1455     g_warning("waiting for channel path...");
1456 #ifndef _WIN32
1457     sleep(QGA_RETRY_INTERVAL);
1458 #else
1459     DWORD dwWaitResult;
1460
1461     dwWaitResult = WaitForSingleObject(s->wakeup_event, INFINITE);
1462
1463     switch (dwWaitResult) {
1464     case WAIT_OBJECT_0:
1465         break;
1466     case WAIT_TIMEOUT:
1467         break;
1468     default:
1469         g_critical("WaitForSingleObject failed");
1470     }
1471 #endif
1472 }
1473
1474 static int run_agent(GAState *s)
1475 {
1476     int ret = EXIT_SUCCESS;
1477
1478     s->force_exit = false;
1479
1480     do {
1481         ret = run_agent_once(s);
1482         if (s->config->retry_path && !s->force_exit) {
1483             g_warning("agent stopped unexpectedly, restarting...");
1484             wait_for_channel_availability(s);
1485         }
1486     } while (s->config->retry_path && !s->force_exit);
1487
1488     return ret;
1489 }
1490
1491 static void stop_agent(GAState *s, bool requested)
1492 {
1493     if (!s->force_exit) {
1494         s->force_exit = requested;
1495     }
1496
1497     if (g_main_loop_is_running(s->main_loop)) {
1498         g_main_loop_quit(s->main_loop);
1499     }
1500 }
1501
1502 int main(int argc, char **argv)
1503 {
1504     int ret = EXIT_SUCCESS;
1505     GAState *s;
1506     GAConfig *config = g_new0(GAConfig, 1);
1507     int socket_activation;
1508
1509     config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1510
1511     qemu_init_exec_dir(argv[0]);
1512     qga_qmp_init_marshal(&ga_commands);
1513
1514     init_dfl_pathnames();
1515     config_load(config);
1516     config_parse(config, argc, argv);
1517
1518     if (config->pid_filepath == NULL) {
1519         config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1520     }
1521
1522     if (config->state_dir == NULL) {
1523         config->state_dir = g_strdup(dfl_pathnames.state_dir);
1524     }
1525
1526     if (config->method == NULL) {
1527         config->method = g_strdup("virtio-serial");
1528     }
1529
1530     socket_activation = check_socket_activation();
1531     if (socket_activation > 1) {
1532         g_critical("qemu-ga only supports listening on one socket");
1533         ret = EXIT_FAILURE;
1534         goto end;
1535     }
1536     if (socket_activation) {
1537         SocketAddress *addr;
1538
1539         g_free(config->method);
1540         g_free(config->channel_path);
1541         config->method = NULL;
1542         config->channel_path = NULL;
1543
1544         addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL);
1545         if (addr) {
1546             if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
1547                 config->method = g_strdup("unix-listen");
1548             } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
1549                 config->method = g_strdup("vsock-listen");
1550             }
1551
1552             qapi_free_SocketAddress(addr);
1553         }
1554
1555         if (!config->method) {
1556             g_critical("unsupported listen fd type");
1557             ret = EXIT_FAILURE;
1558             goto end;
1559         }
1560     } else if (config->channel_path == NULL) {
1561         if (strcmp(config->method, "virtio-serial") == 0) {
1562             /* try the default path for the virtio-serial port */
1563             config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1564         } else if (strcmp(config->method, "isa-serial") == 0) {
1565             /* try the default path for the serial port - COM1 */
1566             config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1567         } else {
1568             g_critical("must specify a path for this channel");
1569             ret = EXIT_FAILURE;
1570             goto end;
1571         }
1572     }
1573
1574     if (config->dumpconf) {
1575         config_dump(config);
1576         goto end;
1577     }
1578
1579     s = initialize_agent(config, socket_activation);
1580     if (!s) {
1581         g_critical("error initializing guest agent");
1582         goto end;
1583     }
1584
1585 #ifdef _WIN32
1586     if (config->daemonize) {
1587         SERVICE_TABLE_ENTRY service_table[] = {
1588             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1589         StartServiceCtrlDispatcher(service_table);
1590     } else {
1591         ret = run_agent(s);
1592     }
1593 #else
1594     ret = run_agent(s);
1595 #endif
1596
1597     cleanup_agent(s);
1598
1599 end:
1600     if (config->daemonize) {
1601         unlink(config->pid_filepath);
1602     }
1603
1604     config_free(config);
1605
1606     return ret;
1607 }