qga/main.c

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