qga/main.c

   1 /*
   2  * QEMU Guest Agent
   3  *
   4  * Copyright IBM Corp. 2011
   5  *
   6  * Authors:
   7  *  Adam Litke        <aglitke@linux.vnet.ibm.com>
   8  *  Michael Roth      <mdroth@linux.vnet.ibm.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  11  * See the COPYING file in the top-level directory.
  12  */
  13
  14 #include "qemu/osdep.h"
  15 #include <getopt.h>
  16 #include <glib/gstdio.h>
  17 #ifndef _WIN32
  18 #include <syslog.h>
  19 #include <sys/wait.h>
  20 #endif
  21 #include "qemu/help-texts.h"
  22 #include "qapi/qmp/json-parser.h"
  23 #include "qapi/qmp/qdict.h"
  24 #include "qapi/qmp/qjson.h"
  25 #include "guest-agent-core.h"
  26 #include "qga-qapi-init-commands.h"
  27 #include "qapi/qmp/qerror.h"
  28 #include "qapi/error.h"
  29 #include "channel.h"
  30 #include "qemu/cutils.h"
  31 #include "qemu/help_option.h"
  32 #include "qemu/sockets.h"
  33 #include "qemu/systemd.h"
  34 #include "qemu-version.h"
  35 #ifdef _WIN32
  36 #include <dbt.h>
  37 #include "qga/service-win32.h"
  38 #include "qga/vss-win32.h"
  39 #endif
  40 #include "commands-common.h"
  41
  42 #ifndef _WIN32
  43 #ifdef __FreeBSD__
  44 #define QGA_VIRTIO_PATH_DEFAULT "/dev/vtcon/org.qemu.guest_agent.0"
  45 #else /* __FreeBSD__ */
  46 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
  47 #endif /* __FreeBSD__ */
  48 #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
  49 #define QGA_STATE_RELATIVE_DIR  "run"
  50 #else
  51 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
  52 #define QGA_STATE_RELATIVE_DIR  "qemu-ga"
  53 #define QGA_SERIAL_PATH_DEFAULT "COM1"
  54 #endif
  55 #ifdef CONFIG_FSFREEZE
  56 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
  57 #endif
  58 #define QGA_SENTINEL_BYTE 0xFF
  59 #define QGA_CONF_DEFAULT CONFIG_QEMU_CONFDIR G_DIR_SEPARATOR_S "qemu-ga.conf"
  60 #define QGA_RETRY_INTERVAL 5
  61
  62 static struct {
  63     const char *state_dir;
  64     const char *pidfile;
  65 } dfl_pathnames;
  66
  67 typedef struct GAPersistentState {
  68 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
  69     int64_t fd_counter;
  70 } GAPersistentState;
  71
  72 typedef struct GAConfig GAConfig;
  73
  74 struct GAState {
  75     JSONMessageParser parser;
  76     GMainLoop *main_loop;
  77     GAChannel *channel;
  78     bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
  79     GACommandState *command_state;
  80     GLogLevelFlags log_level;
  81     FILE *log_file;
  82     bool logging_enabled;
  83 #ifdef _WIN32
  84     GAService service;
  85     HANDLE wakeup_event;
  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 void ga_log(const gchar *domain, GLogLevelFlags level,
 317                    const gchar *msg, gpointer opaque)
 318 {
 319     GAState *s = opaque;
 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_autoptr(GDateTime) now = g_date_time_new_now_utc();
 335         g_autofree char *nowstr = g_date_time_format(now, "%s.%f");
 336         fprintf(s->log_file, "%s: %s: %s\n", nowstr, 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_not_allowed(const QmpCommand *cmd, void *opaque)
 366 {
 367     bool allowed = false;
 368     int i = 0;
 369     const char *name = qmp_command_name(cmd);
 370
 371     while (ga_freeze_allowlist[i] != NULL) {
 372         if (strcmp(name, ga_freeze_allowlist[i]) == 0) {
 373             allowed = true;
 374         }
 375         i++;
 376     }
 377     if (!allowed) {
 378         g_debug("disabling command: %s", name);
 379         qmp_disable_command(&ga_commands, name, "the agent is in frozen state");
 380     }
 381 }
 382
 383 /* [re-]enable all commands, except those explicitly blocked by user */
 384 static void ga_enable_non_blocked(const QmpCommand *cmd, void *opaque)
 385 {
 386     GList *blockedrpcs = opaque;
 387     const char *name = qmp_command_name(cmd);
 388
 389     if (g_list_find_custom(blockedrpcs, 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 forbidden (for frozen state) commands */
 429     qmp_for_each_command(&ga_commands, ga_disable_not_allowed, 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-blocked commands */
 468     qmp_for_each_command(&ga_commands, ga_enable_non_blocked, s->blockedrpcs);
 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     GString *response;
 532     GIOStatus status;
 533
 534     g_assert(s->channel);
 535
 536     if (!rsp) {
 537         return 0;
 538     }
 539
 540     response = qobject_to_json(QOBJECT(rsp));
 541     if (!response) {
 542         return -EINVAL;
 543     }
 544
 545     if (s->delimit_response) {
 546         s->delimit_response = false;
 547         g_string_prepend_c(response, QGA_SENTINEL_BYTE);
 548     }
 549
 550     g_string_append_c(response, '\n');
 551     status = ga_channel_write_all(s->channel, response->str, response->len);
 552     g_string_free(response, true);
 553     if (status != G_IO_STATUS_NORMAL) {
 554         return -EIO;
 555     }
 556
 557     return 0;
 558 }
 559
 560 /* handle requests/control events coming in over the channel */
 561 static void process_event(void *opaque, QObject *obj, Error *err)
 562 {
 563     GAState *s = opaque;
 564     QDict *rsp;
 565     int ret;
 566
 567     g_debug("process_event: called");
 568     assert(!obj != !err);
 569     if (err) {
 570         rsp = qmp_error_response(err);
 571         goto end;
 572     }
 573
 574     g_debug("processing command");
 575     rsp = qmp_dispatch(&ga_commands, obj, false, NULL);
 576
 577 end:
 578     ret = send_response(s, rsp);
 579     if (ret < 0) {
 580         g_warning("error sending error response: %s", strerror(-ret));
 581     }
 582     qobject_unref(rsp);
 583     qobject_unref(obj);
 584 }
 585
 586 /* false return signals GAChannel to close the current client connection */
 587 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 588 {
 589     GAState *s = data;
 590     gchar buf[QGA_READ_COUNT_DEFAULT + 1];
 591     gsize count;
 592     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 593     switch (status) {
 594     case G_IO_STATUS_ERROR:
 595         g_warning("error reading channel");
 596         stop_agent(s, false);
 597         return false;
 598     case G_IO_STATUS_NORMAL:
 599         buf[count] = 0;
 600         g_debug("read data, count: %d, data: %s", (int)count, buf);
 601         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 602         break;
 603     case G_IO_STATUS_EOF:
 604         g_debug("received EOF");
 605         if (!s->virtio) {
 606             return false;
 607         }
 608         /* fall through */
 609     case G_IO_STATUS_AGAIN:
 610         /* virtio causes us to spin here when no process is attached to
 611          * host-side chardev. sleep a bit to mitigate this
 612          */
 613         if (s->virtio) {
 614             g_usleep(G_USEC_PER_SEC / 10);
 615         }
 616         return true;
 617     default:
 618         g_warning("unknown channel read status, closing");
 619         return false;
 620     }
 621     return true;
 622 }
 623
 624 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path,
 625                              int listen_fd)
 626 {
 627     GAChannelMethod channel_method;
 628
 629     if (strcmp(method, "virtio-serial") == 0) {
 630         s->virtio = true; /* virtio requires special handling in some cases */
 631         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 632     } else if (strcmp(method, "isa-serial") == 0) {
 633         channel_method = GA_CHANNEL_ISA_SERIAL;
 634     } else if (strcmp(method, "unix-listen") == 0) {
 635         channel_method = GA_CHANNEL_UNIX_LISTEN;
 636     } else if (strcmp(method, "vsock-listen") == 0) {
 637         channel_method = GA_CHANNEL_VSOCK_LISTEN;
 638     } else {
 639         g_critical("unsupported channel method/type: %s", method);
 640         return false;
 641     }
 642
 643     s->channel = ga_channel_new(channel_method, path, listen_fd,
 644                                 channel_event_cb, s);
 645     if (!s->channel) {
 646         g_critical("failed to create guest agent channel");
 647         return false;
 648     }
 649
 650     return true;
 651 }
 652
 653 #ifdef _WIN32
 654 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data)
 655 {
 656     DWORD ret = NO_ERROR;
 657     PDEV_BROADCAST_HDR broadcast_header = (PDEV_BROADCAST_HDR)data;
 658
 659     if (broadcast_header->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE) {
 660         switch (type) {
 661             /* Device inserted */
 662         case DBT_DEVICEARRIVAL:
 663             /* Start QEMU-ga's service */
 664             if (!SetEvent(ga_state->wakeup_event)) {
 665                 ret = GetLastError();
 666             }
 667             break;
 668             /* Device removed */
 669         case DBT_DEVICEQUERYREMOVE:
 670         case DBT_DEVICEREMOVEPENDING:
 671         case DBT_DEVICEREMOVECOMPLETE:
 672             /* Stop QEMU-ga's service */
 673             if (!ResetEvent(ga_state->wakeup_event)) {
 674                 ret = GetLastError();
 675             }
 676             break;
 677         default:
 678             ret = ERROR_CALL_NOT_IMPLEMENTED;
 679         }
 680     }
 681     return ret;
 682 }
 683
 684 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 685                                   LPVOID ctx)
 686 {
 687     DWORD ret = NO_ERROR;
 688     GAService *service = &ga_state->service;
 689
 690     switch (ctrl) {
 691     case SERVICE_CONTROL_STOP:
 692     case SERVICE_CONTROL_SHUTDOWN:
 693         quit_handler(SIGTERM);
 694         SetEvent(ga_state->wakeup_event);
 695         service->status.dwCurrentState = SERVICE_STOP_PENDING;
 696         SetServiceStatus(service->status_handle, &service->status);
 697         break;
 698     case SERVICE_CONTROL_DEVICEEVENT:
 699         handle_serial_device_events(type, data);
 700         break;
 701
 702     default:
 703         ret = ERROR_CALL_NOT_IMPLEMENTED;
 704     }
 705     return ret;
 706 }
 707
 708 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 709 {
 710     GAService *service = &ga_state->service;
 711
 712     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 713         service_ctrl_handler, NULL);
 714
 715     if (service->status_handle == 0) {
 716         g_critical("Failed to register extended requests function!\n");
 717         return;
 718     }
 719
 720     service->status.dwServiceType = SERVICE_WIN32;
 721     service->status.dwCurrentState = SERVICE_RUNNING;
 722     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 723     service->status.dwWin32ExitCode = NO_ERROR;
 724     service->status.dwServiceSpecificExitCode = NO_ERROR;
 725     service->status.dwCheckPoint = 0;
 726     service->status.dwWaitHint = 0;
 727     DEV_BROADCAST_DEVICEINTERFACE notification_filter;
 728     ZeroMemory(&notification_filter, sizeof(notification_filter));
 729     notification_filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
 730     notification_filter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
 731     notification_filter.dbcc_classguid = GUID_VIOSERIAL_PORT;
 732
 733     service->device_notification_handle =
 734         RegisterDeviceNotification(service->status_handle,
 735             &notification_filter, DEVICE_NOTIFY_SERVICE_HANDLE);
 736     if (!service->device_notification_handle) {
 737         g_critical("Failed to register device notification handle!\n");
 738         return;
 739     }
 740     SetServiceStatus(service->status_handle, &service->status);
 741
 742     run_agent(ga_state);
 743
 744     UnregisterDeviceNotification(service->device_notification_handle);
 745     service->status.dwCurrentState = SERVICE_STOPPED;
 746     SetServiceStatus(service->status_handle, &service->status);
 747 }
 748 #endif
 749
 750 static void set_persistent_state_defaults(GAPersistentState *pstate)
 751 {
 752     g_assert(pstate);
 753     pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
 754 }
 755
 756 static void persistent_state_from_keyfile(GAPersistentState *pstate,
 757                                           GKeyFile *keyfile)
 758 {
 759     g_assert(pstate);
 760     g_assert(keyfile);
 761     /* if any fields are missing, either because the file was tampered with
 762      * by agents of chaos, or because the field wasn't present at the time the
 763      * file was created, the best we can ever do is start over with the default
 764      * values. so load them now, and ignore any errors in accessing key-value
 765      * pairs
 766      */
 767     set_persistent_state_defaults(pstate);
 768
 769     if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
 770         pstate->fd_counter =
 771             g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
 772     }
 773 }
 774
 775 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
 776                                         GKeyFile *keyfile)
 777 {
 778     g_assert(pstate);
 779     g_assert(keyfile);
 780
 781     g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
 782 }
 783
 784 static gboolean write_persistent_state(const GAPersistentState *pstate,
 785                                        const gchar *path)
 786 {
 787     GKeyFile *keyfile = g_key_file_new();
 788     GError *gerr = NULL;
 789     gboolean ret = true;
 790     gchar *data = NULL;
 791     gsize data_len;
 792
 793     g_assert(pstate);
 794
 795     persistent_state_to_keyfile(pstate, keyfile);
 796     data = g_key_file_to_data(keyfile, &data_len, &gerr);
 797     if (gerr) {
 798         g_critical("failed to convert persistent state to string: %s",
 799                    gerr->message);
 800         ret = false;
 801         goto out;
 802     }
 803
 804     g_file_set_contents(path, data, data_len, &gerr);
 805     if (gerr) {
 806         g_critical("failed to write persistent state to %s: %s",
 807                     path, gerr->message);
 808         ret = false;
 809         goto out;
 810     }
 811
 812 out:
 813     if (gerr) {
 814         g_error_free(gerr);
 815     }
 816     if (keyfile) {
 817         g_key_file_free(keyfile);
 818     }
 819     g_free(data);
 820     return ret;
 821 }
 822
 823 static gboolean read_persistent_state(GAPersistentState *pstate,
 824                                       const gchar *path, gboolean frozen)
 825 {
 826     GKeyFile *keyfile = NULL;
 827     GError *gerr = NULL;
 828     struct stat st;
 829     gboolean ret = true;
 830
 831     g_assert(pstate);
 832
 833     if (stat(path, &st) == -1) {
 834         /* it's okay if state file doesn't exist, but any other error
 835          * indicates a permissions issue or some other misconfiguration
 836          * that we likely won't be able to recover from.
 837          */
 838         if (errno != ENOENT) {
 839             g_critical("unable to access state file at path %s: %s",
 840                        path, strerror(errno));
 841             ret = false;
 842             goto out;
 843         }
 844
 845         /* file doesn't exist. initialize state to default values and
 846          * attempt to save now. (we could wait till later when we have
 847          * modified state we need to commit, but if there's a problem,
 848          * such as a missing parent directory, we want to catch it now)
 849          *
 850          * there is a potential scenario where someone either managed to
 851          * update the agent from a version that didn't use a key store
 852          * while qemu-ga thought the filesystem was frozen, or
 853          * deleted the key store prior to issuing a fsfreeze, prior
 854          * to restarting the agent. in this case we go ahead and defer
 855          * initial creation till we actually have modified state to
 856          * write, otherwise fail to recover from freeze.
 857          */
 858         set_persistent_state_defaults(pstate);
 859         if (!frozen) {
 860             ret = write_persistent_state(pstate, path);
 861             if (!ret) {
 862                 g_critical("unable to create state file at path %s", path);
 863                 ret = false;
 864                 goto out;
 865             }
 866         }
 867         ret = true;
 868         goto out;
 869     }
 870
 871     keyfile = g_key_file_new();
 872     g_key_file_load_from_file(keyfile, path, 0, &gerr);
 873     if (gerr) {
 874         g_critical("error loading persistent state from path: %s, %s",
 875                    path, gerr->message);
 876         ret = false;
 877         goto out;
 878     }
 879
 880     persistent_state_from_keyfile(pstate, keyfile);
 881
 882 out:
 883     if (keyfile) {
 884         g_key_file_free(keyfile);
 885     }
 886     if (gerr) {
 887         g_error_free(gerr);
 888     }
 889
 890     return ret;
 891 }
 892
 893 int64_t ga_get_fd_handle(GAState *s, Error **errp)
 894 {
 895     int64_t handle;
 896
 897     g_assert(s->pstate_filepath);
 898     /*
 899      * We block commands and avoid operations that potentially require
 900      * writing to disk when we're in a frozen state. this includes opening
 901      * new files, so we should never get here in that situation
 902      */
 903     g_assert(!ga_is_frozen(s));
 904
 905     handle = s->pstate.fd_counter++;
 906
 907     /* This should never happen on a reasonable timeframe, as guest-file-open
 908      * would have to be issued 2^63 times */
 909     if (s->pstate.fd_counter == INT64_MAX) {
 910         abort();
 911     }
 912
 913     if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
 914         error_setg(errp, "failed to commit persistent state to disk");
 915         return -1;
 916     }
 917
 918     return handle;
 919 }
 920
 921 static void ga_print_cmd(const QmpCommand *cmd, void *opaque)
 922 {
 923     printf("%s\n", qmp_command_name(cmd));
 924 }
 925
 926 static GList *split_list(const gchar *str, const gchar *delim)
 927 {
 928     GList *list = NULL;
 929     int i;
 930     gchar **strv;
 931
 932     strv = g_strsplit(str, delim, -1);
 933     for (i = 0; strv[i]; i++) {
 934         list = g_list_prepend(list, strv[i]);
 935     }
 936     g_free(strv);
 937
 938     return list;
 939 }
 940
 941 struct GAConfig {
 942     char *channel_path;
 943     char *method;
 944     char *log_filepath;
 945     char *pid_filepath;
 946 #ifdef CONFIG_FSFREEZE
 947     char *fsfreeze_hook;
 948 #endif
 949     char *state_dir;
 950 #ifdef _WIN32
 951     const char *service;
 952 #endif
 953     gchar *bliststr; /* blockedrpcs may point to this string */
 954     GList *blockedrpcs;
 955     int daemonize;
 956     GLogLevelFlags log_level;
 957     int dumpconf;
 958     bool retry_path;
 959 };
 960
 961 static void config_load(GAConfig *config)
 962 {
 963     GError *gerr = NULL;
 964     GKeyFile *keyfile;
 965     g_autofree char *conf = g_strdup(g_getenv("QGA_CONF")) ?: get_relocated_path(QGA_CONF_DEFAULT);
 966     const gchar *blockrpcs_key = "block-rpcs";
 967
 968     /* read system config */
 969     keyfile = g_key_file_new();
 970     if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
 971         goto end;
 972     }
 973     if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
 974         config->daemonize =
 975             g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
 976     }
 977     if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
 978         config->method =
 979             g_key_file_get_string(keyfile, "general", "method", &gerr);
 980     }
 981     if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
 982         config->channel_path =
 983             g_key_file_get_string(keyfile, "general", "path", &gerr);
 984     }
 985     if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
 986         config->log_filepath =
 987             g_key_file_get_string(keyfile, "general", "logfile", &gerr);
 988     }
 989     if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
 990         config->pid_filepath =
 991             g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
 992     }
 993 #ifdef CONFIG_FSFREEZE
 994     if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
 995         config->fsfreeze_hook =
 996             g_key_file_get_string(keyfile,
 997                                   "general", "fsfreeze-hook", &gerr);
 998     }
 999 #endif
1000     if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
1001         config->state_dir =
1002             g_key_file_get_string(keyfile, "general", "statedir", &gerr);
1003     }
1004     if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
1005         g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
1006         /* enable all log levels */
1007         config->log_level = G_LOG_LEVEL_MASK;
1008     }
1009     if (g_key_file_has_key(keyfile, "general", "retry-path", NULL)) {
1010         config->retry_path =
1011             g_key_file_get_boolean(keyfile, "general", "retry-path", &gerr);
1012     }
1013
1014     if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
1015         g_warning("config using deprecated 'blacklist' key, should be replaced"
1016                   " with the 'block-rpcs' key.");
1017         blockrpcs_key = "blacklist";
1018     }
1019     if (g_key_file_has_key(keyfile, "general", blockrpcs_key, NULL)) {
1020         config->bliststr =
1021             g_key_file_get_string(keyfile, "general", blockrpcs_key, &gerr);
1022         config->blockedrpcs = g_list_concat(config->blockedrpcs,
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->blockedrpcs, ',');
1083     g_key_file_set_string(keyfile, "general", "block-rpcs", 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         { "block-rpcs", 1, NULL, 'b' },
1116         { "blacklist", 1, NULL, 'b' },  /* deprecated alias for 'block-rpcs' */
1117 #ifdef _WIN32
1118         { "service", 1, NULL, 's' },
1119 #endif
1120         { "statedir", 1, NULL, 't' },
1121         { "retry-path", 0, NULL, 'r' },
1122         { NULL, 0, NULL, 0 }
1123     };
1124
1125     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1126         switch (ch) {
1127         case 'm':
1128             g_free(config->method);
1129             config->method = g_strdup(optarg);
1130             break;
1131         case 'p':
1132             g_free(config->channel_path);
1133             config->channel_path = g_strdup(optarg);
1134             break;
1135         case 'l':
1136             g_free(config->log_filepath);
1137             config->log_filepath = g_strdup(optarg);
1138             break;
1139         case 'f':
1140             g_free(config->pid_filepath);
1141             config->pid_filepath = g_strdup(optarg);
1142             break;
1143 #ifdef CONFIG_FSFREEZE
1144         case 'F':
1145             g_free(config->fsfreeze_hook);
1146             config->fsfreeze_hook = optarg ? g_strdup(optarg) : get_relocated_path(QGA_FSFREEZE_HOOK_DEFAULT);
1147             break;
1148 #endif
1149         case 't':
1150             g_free(config->state_dir);
1151             config->state_dir = g_strdup(optarg);
1152             break;
1153         case 'v':
1154             /* enable all log levels */
1155             config->log_level = G_LOG_LEVEL_MASK;
1156             break;
1157         case 'V':
1158             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1159             exit(EXIT_SUCCESS);
1160         case 'd':
1161             config->daemonize = 1;
1162             break;
1163         case 'D':
1164             config->dumpconf = 1;
1165             break;
1166         case 'r':
1167             config->retry_path = true;
1168             break;
1169         case 'b': {
1170             if (is_help_option(optarg)) {
1171                 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1172                 exit(EXIT_SUCCESS);
1173             }
1174             config->blockedrpcs = g_list_concat(config->blockedrpcs,
1175                                                 split_list(optarg, ","));
1176             break;
1177         }
1178 #ifdef _WIN32
1179         case 's':
1180             config->service = optarg;
1181             if (strcmp(config->service, "install") == 0) {
1182                 if (ga_install_vss_provider()) {
1183                     exit(EXIT_FAILURE);
1184                 }
1185                 if (ga_install_service(config->channel_path,
1186                                        config->log_filepath, config->state_dir)) {
1187                     exit(EXIT_FAILURE);
1188                 }
1189                 exit(EXIT_SUCCESS);
1190             } else if (strcmp(config->service, "uninstall") == 0) {
1191                 ga_uninstall_vss_provider();
1192                 exit(ga_uninstall_service());
1193             } else if (strcmp(config->service, "vss-install") == 0) {
1194                 if (ga_install_vss_provider()) {
1195                     exit(EXIT_FAILURE);
1196                 }
1197                 exit(EXIT_SUCCESS);
1198             } else if (strcmp(config->service, "vss-uninstall") == 0) {
1199                 ga_uninstall_vss_provider();
1200                 exit(EXIT_SUCCESS);
1201             } else {
1202                 printf("Unknown service command.\n");
1203                 exit(EXIT_FAILURE);
1204             }
1205             break;
1206 #endif
1207         case 'h':
1208             usage(argv[0]);
1209             exit(EXIT_SUCCESS);
1210         case '?':
1211             g_print("Unknown option, try '%s --help' for more information.\n",
1212                     argv[0]);
1213             exit(EXIT_FAILURE);
1214         }
1215     }
1216 }
1217
1218 static void config_free(GAConfig *config)
1219 {
1220     g_free(config->method);
1221     g_free(config->log_filepath);
1222     g_free(config->pid_filepath);
1223     g_free(config->state_dir);
1224     g_free(config->channel_path);
1225     g_free(config->bliststr);
1226 #ifdef CONFIG_FSFREEZE
1227     g_free(config->fsfreeze_hook);
1228 #endif
1229     g_list_free_full(config->blockedrpcs, g_free);
1230     g_free(config);
1231 }
1232
1233 static bool check_is_frozen(GAState *s)
1234 {
1235 #ifndef _WIN32
1236     /* check if a previous instance of qemu-ga exited with filesystems' state
1237      * marked as frozen. this could be a stale value (a non-qemu-ga process
1238      * or reboot may have since unfrozen them), but better to require an
1239      * uneeded unfreeze than to risk hanging on start-up
1240      */
1241     struct stat st;
1242     if (stat(s->state_filepath_isfrozen, &st) == -1) {
1243         /* it's okay if the file doesn't exist, but if we can't access for
1244          * some other reason, such as permissions, there's a configuration
1245          * that needs to be addressed. so just bail now before we get into
1246          * more trouble later
1247          */
1248         if (errno != ENOENT) {
1249             g_critical("unable to access state file at path %s: %s",
1250                        s->state_filepath_isfrozen, strerror(errno));
1251             return EXIT_FAILURE;
1252         }
1253     } else {
1254         g_warning("previous instance appears to have exited with frozen"
1255                   " filesystems. deferring logging/pidfile creation and"
1256                   " disabling non-fsfreeze-safe commands until"
1257                   " guest-fsfreeze-thaw is issued, or filesystems are"
1258                   " manually unfrozen and the file %s is removed",
1259                   s->state_filepath_isfrozen);
1260         return true;
1261     }
1262 #endif
1263     return false;
1264 }
1265
1266 static GAState *initialize_agent(GAConfig *config, int socket_activation)
1267 {
1268     GAState *s = g_new0(GAState, 1);
1269
1270     g_assert(ga_state == NULL);
1271
1272     s->log_level = config->log_level;
1273     s->log_file = stderr;
1274 #ifdef CONFIG_FSFREEZE
1275     s->fsfreeze_hook = config->fsfreeze_hook;
1276 #endif
1277     s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1278     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1279                                                  config->state_dir);
1280     s->frozen = check_is_frozen(s);
1281
1282     g_log_set_default_handler(ga_log, s);
1283     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1284     ga_enable_logging(s);
1285
1286     g_debug("Guest agent version %s started", QEMU_FULL_VERSION);
1287
1288 #ifdef _WIN32
1289     /* On win32 the state directory is application specific (be it the default
1290      * or a user override). We got past the command line parsing; let's create
1291      * the directory (with any intermediate directories). If we run into an
1292      * error later on, we won't try to clean up the directory, it is considered
1293      * persistent.
1294      */
1295     if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1296         g_critical("unable to create (an ancestor of) the state directory"
1297                    " '%s': %s", config->state_dir, strerror(errno));
1298         return NULL;
1299     }
1300 #endif
1301
1302     if (ga_is_frozen(s)) {
1303         if (config->daemonize) {
1304             /* delay opening/locking of pidfile till filesystems are unfrozen */
1305             s->deferred_options.pid_filepath = config->pid_filepath;
1306             become_daemon(NULL);
1307         }
1308         if (config->log_filepath) {
1309             /* delay opening the log file till filesystems are unfrozen */
1310             s->deferred_options.log_filepath = config->log_filepath;
1311         }
1312         ga_disable_logging(s);
1313         qmp_for_each_command(&ga_commands, ga_disable_not_allowed, NULL);
1314     } else {
1315         if (config->daemonize) {
1316             become_daemon(config->pid_filepath);
1317         }
1318         if (config->log_filepath) {
1319             FILE *log_file = ga_open_logfile(config->log_filepath);
1320             if (!log_file) {
1321                 g_critical("unable to open specified log file: %s",
1322                            strerror(errno));
1323                 return NULL;
1324             }
1325             s->log_file = log_file;
1326         }
1327     }
1328
1329     /* load persistent state from disk */
1330     if (!read_persistent_state(&s->pstate,
1331                                s->pstate_filepath,
1332                                ga_is_frozen(s))) {
1333         g_critical("failed to load persistent state");
1334         return NULL;
1335     }
1336
1337     config->blockedrpcs = ga_command_init_blockedrpcs(config->blockedrpcs);
1338     if (config->blockedrpcs) {
1339         GList *l = config->blockedrpcs;
1340         s->blockedrpcs = config->blockedrpcs;
1341         do {
1342             g_debug("disabling command: %s", (char *)l->data);
1343             qmp_disable_command(&ga_commands, l->data, NULL);
1344             l = g_list_next(l);
1345         } while (l);
1346     }
1347     s->command_state = ga_command_state_new();
1348     ga_command_state_init(s, s->command_state);
1349     ga_command_state_init_all(s->command_state);
1350     json_message_parser_init(&s->parser, process_event, s, NULL);
1351
1352 #ifndef _WIN32
1353     if (!register_signal_handlers()) {
1354         g_critical("failed to register signal handlers");
1355         return NULL;
1356     }
1357 #endif
1358
1359     s->main_loop = g_main_loop_new(NULL, false);
1360
1361     s->config = config;
1362     s->socket_activation = socket_activation;
1363
1364 #ifdef _WIN32
1365     s->wakeup_event = CreateEvent(NULL, TRUE, FALSE, TEXT("WakeUp"));
1366     if (s->wakeup_event == NULL) {
1367         g_critical("CreateEvent failed");
1368         return NULL;
1369     }
1370 #endif
1371
1372     ga_state = s;
1373     return s;
1374 }
1375
1376 static void cleanup_agent(GAState *s)
1377 {
1378 #ifdef _WIN32
1379     CloseHandle(s->wakeup_event);
1380 #endif
1381     if (s->command_state) {
1382         ga_command_state_cleanup_all(s->command_state);
1383         ga_command_state_free(s->command_state);
1384         json_message_parser_destroy(&s->parser);
1385     }
1386     g_free(s->pstate_filepath);
1387     g_free(s->state_filepath_isfrozen);
1388     if (s->main_loop) {
1389         g_main_loop_unref(s->main_loop);
1390     }
1391     g_free(s);
1392     ga_state = NULL;
1393 }
1394
1395 static int run_agent_once(GAState *s)
1396 {
1397     if (!channel_init(s, s->config->method, s->config->channel_path,
1398                       s->socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
1399         g_critical("failed to initialize guest agent channel");
1400         return EXIT_FAILURE;
1401     }
1402
1403     g_main_loop_run(ga_state->main_loop);
1404
1405     if (s->channel) {
1406         ga_channel_free(s->channel);
1407     }
1408
1409     return EXIT_SUCCESS;
1410 }
1411
1412 static void wait_for_channel_availability(GAState *s)
1413 {
1414     g_warning("waiting for channel path...");
1415 #ifndef _WIN32
1416     sleep(QGA_RETRY_INTERVAL);
1417 #else
1418     DWORD dwWaitResult;
1419
1420     dwWaitResult = WaitForSingleObject(s->wakeup_event, INFINITE);
1421
1422     switch (dwWaitResult) {
1423     case WAIT_OBJECT_0:
1424         break;
1425     case WAIT_TIMEOUT:
1426         break;
1427     default:
1428         g_critical("WaitForSingleObject failed");
1429     }
1430 #endif
1431 }
1432
1433 static int run_agent(GAState *s)
1434 {
1435     int ret = EXIT_SUCCESS;
1436
1437     s->force_exit = false;
1438
1439     do {
1440         ret = run_agent_once(s);
1441         if (s->config->retry_path && !s->force_exit) {
1442             g_warning("agent stopped unexpectedly, restarting...");
1443             wait_for_channel_availability(s);
1444         }
1445     } while (s->config->retry_path && !s->force_exit);
1446
1447     return ret;
1448 }
1449
1450 static void stop_agent(GAState *s, bool requested)
1451 {
1452     if (!s->force_exit) {
1453         s->force_exit = requested;
1454     }
1455
1456     if (g_main_loop_is_running(s->main_loop)) {
1457         g_main_loop_quit(s->main_loop);
1458     }
1459 }
1460
1461 int main(int argc, char **argv)
1462 {
1463     int ret = EXIT_SUCCESS;
1464     GAState *s;
1465     GAConfig *config = g_new0(GAConfig, 1);
1466     int socket_activation;
1467
1468     config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1469
1470     qemu_init_exec_dir(argv[0]);
1471     qga_qmp_init_marshal(&ga_commands);
1472
1473     init_dfl_pathnames();
1474     config_load(config);
1475     config_parse(config, argc, argv);
1476
1477     if (config->pid_filepath == NULL) {
1478         config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1479     }
1480
1481     if (config->state_dir == NULL) {
1482         config->state_dir = g_strdup(dfl_pathnames.state_dir);
1483     }
1484
1485     if (config->method == NULL) {
1486         config->method = g_strdup("virtio-serial");
1487     }
1488
1489     socket_activation = check_socket_activation();
1490     if (socket_activation > 1) {
1491         g_critical("qemu-ga only supports listening on one socket");
1492         ret = EXIT_FAILURE;
1493         goto end;
1494     }
1495     if (socket_activation) {
1496         SocketAddress *addr;
1497
1498         g_free(config->method);
1499         g_free(config->channel_path);
1500         config->method = NULL;
1501         config->channel_path = NULL;
1502
1503         addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL);
1504         if (addr) {
1505             if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
1506                 config->method = g_strdup("unix-listen");
1507             } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
1508                 config->method = g_strdup("vsock-listen");
1509             }
1510
1511             qapi_free_SocketAddress(addr);
1512         }
1513
1514         if (!config->method) {
1515             g_critical("unsupported listen fd type");
1516             ret = EXIT_FAILURE;
1517             goto end;
1518         }
1519     } else if (config->channel_path == NULL) {
1520         if (strcmp(config->method, "virtio-serial") == 0) {
1521             /* try the default path for the virtio-serial port */
1522             config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1523         } else if (strcmp(config->method, "isa-serial") == 0) {
1524             /* try the default path for the serial port - COM1 */
1525             config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1526         } else {
1527             g_critical("must specify a path for this channel");
1528             ret = EXIT_FAILURE;
1529             goto end;
1530         }
1531     }
1532
1533     if (config->dumpconf) {
1534         config_dump(config);
1535         goto end;
1536     }
1537
1538     s = initialize_agent(config, socket_activation);
1539     if (!s) {
1540         g_critical("error initializing guest agent");
1541         goto end;
1542     }
1543
1544 #ifdef _WIN32
1545     if (config->daemonize) {
1546         SERVICE_TABLE_ENTRY service_table[] = {
1547             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1548         StartServiceCtrlDispatcher(service_table);
1549     } else {
1550         ret = run_agent(s);
1551     }
1552 #else
1553     ret = run_agent(s);
1554 #endif
1555
1556     cleanup_agent(s);
1557
1558 end:
1559     if (config->daemonize) {
1560         unlink(config->pid_filepath);
1561     }
1562
1563     config_free(config);
1564
1565     return ret;
1566 }