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