qga/main.c

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