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 #include <stdlib.h>
  14 #include <stdio.h>
  15 #include <stdbool.h>
  16 #include <glib.h>
  17 #include <getopt.h>
  18 #include <glib/gstdio.h>
  19 #ifndef _WIN32
  20 #include <syslog.h>
  21 #include <sys/wait.h>
  22 #include <sys/stat.h>
  23 #endif
  24 #include "qapi/qmp/json-streamer.h"
  25 #include "qapi/qmp/json-parser.h"
  26 #include "qapi/qmp/qint.h"
  27 #include "qapi/qmp/qjson.h"
  28 #include "qga/guest-agent-core.h"
  29 #include "qemu/module.h"
  30 #include "signal.h"
  31 #include "qapi/qmp/qerror.h"
  32 #include "qapi/qmp/dispatch.h"
  33 #include "qga/channel.h"
  34 #include "qemu/bswap.h"
  35 #ifdef _WIN32
  36 #include "qga/service-win32.h"
  37 #include "qga/vss-win32.h"
  38 #include <windows.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 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
  49 #define QGA_STATE_RELATIVE_DIR  "run"
  50 #else
  51 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
  52 #define QGA_STATE_RELATIVE_DIR  "qemu-ga"
  53 #endif
  54 #ifdef CONFIG_FSFREEZE
  55 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
  56 #endif
  57 #define QGA_SENTINEL_BYTE 0xFF
  58
  59 static struct {
  60     const char *state_dir;
  61     const char *pidfile;
  62 } dfl_pathnames;
  63
  64 typedef struct GAPersistentState {
  65 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
  66     int64_t fd_counter;
  67 } GAPersistentState;
  68
  69 struct GAState {
  70     JSONMessageParser parser;
  71     GMainLoop *main_loop;
  72     GAChannel *channel;
  73     bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
  74     GACommandState *command_state;
  75     GLogLevelFlags log_level;
  76     FILE *log_file;
  77     bool logging_enabled;
  78 #ifdef _WIN32
  79     GAService service;
  80 #endif
  81     bool delimit_response;
  82     bool frozen;
  83     GList *blacklist;
  84     const char *state_filepath_isfrozen;
  85     struct {
  86         const char *log_filepath;
  87         const char *pid_filepath;
  88     } deferred_options;
  89 #ifdef CONFIG_FSFREEZE
  90     const char *fsfreeze_hook;
  91 #endif
  92     const gchar *pstate_filepath;
  93     GAPersistentState pstate;
  94 };
  95
  96 struct GAState *ga_state;
  97
  98 /* commands that are safe to issue while filesystems are frozen */
  99 static const char *ga_freeze_whitelist[] = {
 100     "guest-ping",
 101     "guest-info",
 102     "guest-sync",
 103     "guest-sync-delimited",
 104     "guest-fsfreeze-status",
 105     "guest-fsfreeze-thaw",
 106     NULL
 107 };
 108
 109 #ifdef _WIN32
 110 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 111                                   LPVOID ctx);
 112 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
 113 #endif
 114
 115 static void
 116 init_dfl_pathnames(void)
 117 {
 118     g_assert(dfl_pathnames.state_dir == NULL);
 119     g_assert(dfl_pathnames.pidfile == NULL);
 120     dfl_pathnames.state_dir = qemu_get_local_state_pathname(
 121       QGA_STATE_RELATIVE_DIR);
 122     dfl_pathnames.pidfile   = qemu_get_local_state_pathname(
 123       QGA_STATE_RELATIVE_DIR G_DIR_SEPARATOR_S "qemu-ga.pid");
 124 }
 125
 126 static void quit_handler(int sig)
 127 {
 128     /* if we're frozen, don't exit unless we're absolutely forced to,
 129      * because it's basically impossible for graceful exit to complete
 130      * unless all log/pid files are on unfreezable filesystems. there's
 131      * also a very likely chance killing the agent before unfreezing
 132      * the filesystems is a mistake (or will be viewed as one later).
 133      */
 134     if (ga_is_frozen(ga_state)) {
 135         return;
 136     }
 137     g_debug("received signal num %d, quitting", sig);
 138
 139     if (g_main_loop_is_running(ga_state->main_loop)) {
 140         g_main_loop_quit(ga_state->main_loop);
 141     }
 142 }
 143
 144 #ifndef _WIN32
 145 static gboolean register_signal_handlers(void)
 146 {
 147     struct sigaction sigact;
 148     int ret;
 149
 150     memset(&sigact, 0, sizeof(struct sigaction));
 151     sigact.sa_handler = quit_handler;
 152
 153     ret = sigaction(SIGINT, &sigact, NULL);
 154     if (ret == -1) {
 155         g_error("error configuring signal handler: %s", strerror(errno));
 156     }
 157     ret = sigaction(SIGTERM, &sigact, NULL);
 158     if (ret == -1) {
 159         g_error("error configuring signal handler: %s", strerror(errno));
 160     }
 161
 162     return true;
 163 }
 164
 165 /* TODO: use this in place of all post-fork() fclose(std*) callers */
 166 void reopen_fd_to_null(int fd)
 167 {
 168     int nullfd;
 169
 170     nullfd = open("/dev/null", O_RDWR);
 171     if (nullfd < 0) {
 172         return;
 173     }
 174
 175     dup2(nullfd, fd);
 176
 177     if (nullfd != fd) {
 178         close(nullfd);
 179     }
 180 }
 181 #endif
 182
 183 static void usage(const char *cmd)
 184 {
 185     printf(
 186 "Usage: %s [-m <method> -p <path>] [<options>]\n"
 187 "QEMU Guest Agent %s\n"
 188 "\n"
 189 "  -m, --method      transport method: one of unix-listen, virtio-serial, or\n"
 190 "                    isa-serial (virtio-serial is the default)\n"
 191 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
 192 "                    %s)\n"
 193 "  -l, --logfile     set logfile path, logs to stderr by default\n"
 194 "  -f, --pidfile     specify pidfile (default is %s)\n"
 195 #ifdef CONFIG_FSFREEZE
 196 "  -F, --fsfreeze-hook\n"
 197 "                    enable fsfreeze hook. Accepts an optional argument that\n"
 198 "                    specifies script to run on freeze/thaw. Script will be\n"
 199 "                    called with 'freeze'/'thaw' arguments accordingly.\n"
 200 "                    (default is %s)\n"
 201 "                    If using -F with an argument, do not follow -F with a\n"
 202 "                    space.\n"
 203 "                    (for example: -F/var/run/fsfreezehook.sh)\n"
 204 #endif
 205 "  -t, --statedir    specify dir to store state information (absolute paths\n"
 206 "                    only, default is %s)\n"
 207 "  -v, --verbose     log extra debugging information\n"
 208 "  -V, --version     print version information and exit\n"
 209 "  -d, --daemonize   become a daemon\n"
 210 #ifdef _WIN32
 211 "  -s, --service     service commands: install, uninstall\n"
 212 #endif
 213 "  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\"\n"
 214 "                    to list available RPCs)\n"
 215 "  -h, --help        display this help and exit\n"
 216 "\n"
 217 "Report bugs to <mdroth@linux.vnet.ibm.com>\n"
 218     , cmd, QEMU_VERSION, QGA_VIRTIO_PATH_DEFAULT, dfl_pathnames.pidfile,
 219 #ifdef CONFIG_FSFREEZE
 220     QGA_FSFREEZE_HOOK_DEFAULT,
 221 #endif
 222     dfl_pathnames.state_dir);
 223 }
 224
 225 static const char *ga_log_level_str(GLogLevelFlags level)
 226 {
 227     switch (level & G_LOG_LEVEL_MASK) {
 228         case G_LOG_LEVEL_ERROR:
 229             return "error";
 230         case G_LOG_LEVEL_CRITICAL:
 231             return "critical";
 232         case G_LOG_LEVEL_WARNING:
 233             return "warning";
 234         case G_LOG_LEVEL_MESSAGE:
 235             return "message";
 236         case G_LOG_LEVEL_INFO:
 237             return "info";
 238         case G_LOG_LEVEL_DEBUG:
 239             return "debug";
 240         default:
 241             return "user";
 242     }
 243 }
 244
 245 bool ga_logging_enabled(GAState *s)
 246 {
 247     return s->logging_enabled;
 248 }
 249
 250 void ga_disable_logging(GAState *s)
 251 {
 252     s->logging_enabled = false;
 253 }
 254
 255 void ga_enable_logging(GAState *s)
 256 {
 257     s->logging_enabled = true;
 258 }
 259
 260 static void ga_log(const gchar *domain, GLogLevelFlags level,
 261                    const gchar *msg, gpointer opaque)
 262 {
 263     GAState *s = opaque;
 264     GTimeVal time;
 265     const char *level_str = ga_log_level_str(level);
 266
 267     if (!ga_logging_enabled(s)) {
 268         return;
 269     }
 270
 271     level &= G_LOG_LEVEL_MASK;
 272 #ifndef _WIN32
 273     if (domain && strcmp(domain, "syslog") == 0) {
 274         syslog(LOG_INFO, "%s: %s", level_str, msg);
 275     } else if (level & s->log_level) {
 276 #else
 277     if (level & s->log_level) {
 278 #endif
 279         g_get_current_time(&time);
 280         fprintf(s->log_file,
 281                 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
 282         fflush(s->log_file);
 283     }
 284 }
 285
 286 void ga_set_response_delimited(GAState *s)
 287 {
 288     s->delimit_response = true;
 289 }
 290
 291 static FILE *ga_open_logfile(const char *logfile)
 292 {
 293     FILE *f;
 294
 295     f = fopen(logfile, "a");
 296     if (!f) {
 297         return NULL;
 298     }
 299
 300     qemu_set_cloexec(fileno(f));
 301     return f;
 302 }
 303
 304 #ifndef _WIN32
 305 static bool ga_open_pidfile(const char *pidfile)
 306 {
 307     int pidfd;
 308     char pidstr[32];
 309
 310     pidfd = qemu_open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
 311     if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) {
 312         g_critical("Cannot lock pid file, %s", strerror(errno));
 313         if (pidfd != -1) {
 314             close(pidfd);
 315         }
 316         return false;
 317     }
 318
 319     if (ftruncate(pidfd, 0)) {
 320         g_critical("Failed to truncate pid file");
 321         goto fail;
 322     }
 323     snprintf(pidstr, sizeof(pidstr), "%d\n", getpid());
 324     if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
 325         g_critical("Failed to write pid file");
 326         goto fail;
 327     }
 328
 329     /* keep pidfile open & locked forever */
 330     return true;
 331
 332 fail:
 333     unlink(pidfile);
 334     close(pidfd);
 335     return false;
 336 }
 337 #else /* _WIN32 */
 338 static bool ga_open_pidfile(const char *pidfile)
 339 {
 340     return true;
 341 }
 342 #endif
 343
 344 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
 345 {
 346     return strcmp(str1, str2);
 347 }
 348
 349 /* disable commands that aren't safe for fsfreeze */
 350 static void ga_disable_non_whitelisted(QmpCommand *cmd, void *opaque)
 351 {
 352     bool whitelisted = false;
 353     int i = 0;
 354     const char *name = qmp_command_name(cmd);
 355
 356     while (ga_freeze_whitelist[i] != NULL) {
 357         if (strcmp(name, ga_freeze_whitelist[i]) == 0) {
 358             whitelisted = true;
 359         }
 360         i++;
 361     }
 362     if (!whitelisted) {
 363         g_debug("disabling command: %s", name);
 364         qmp_disable_command(name);
 365     }
 366 }
 367
 368 /* [re-]enable all commands, except those explicitly blacklisted by user */
 369 static void ga_enable_non_blacklisted(QmpCommand *cmd, void *opaque)
 370 {
 371     GList *blacklist = opaque;
 372     const char *name = qmp_command_name(cmd);
 373
 374     if (g_list_find_custom(blacklist, name, ga_strcmp) == NULL &&
 375         !qmp_command_is_enabled(cmd)) {
 376         g_debug("enabling command: %s", name);
 377         qmp_enable_command(name);
 378     }
 379 }
 380
 381 static bool ga_create_file(const char *path)
 382 {
 383     int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
 384     if (fd == -1) {
 385         g_warning("unable to open/create file %s: %s", path, strerror(errno));
 386         return false;
 387     }
 388     close(fd);
 389     return true;
 390 }
 391
 392 static bool ga_delete_file(const char *path)
 393 {
 394     int ret = unlink(path);
 395     if (ret == -1) {
 396         g_warning("unable to delete file: %s: %s", path, strerror(errno));
 397         return false;
 398     }
 399
 400     return true;
 401 }
 402
 403 bool ga_is_frozen(GAState *s)
 404 {
 405     return s->frozen;
 406 }
 407
 408 void ga_set_frozen(GAState *s)
 409 {
 410     if (ga_is_frozen(s)) {
 411         return;
 412     }
 413     /* disable all non-whitelisted (for frozen state) commands */
 414     qmp_for_each_command(ga_disable_non_whitelisted, NULL);
 415     g_warning("disabling logging due to filesystem freeze");
 416     ga_disable_logging(s);
 417     s->frozen = true;
 418     if (!ga_create_file(s->state_filepath_isfrozen)) {
 419         g_warning("unable to create %s, fsfreeze may not function properly",
 420                   s->state_filepath_isfrozen);
 421     }
 422 }
 423
 424 void ga_unset_frozen(GAState *s)
 425 {
 426     if (!ga_is_frozen(s)) {
 427         return;
 428     }
 429
 430     /* if we delayed creation/opening of pid/log files due to being
 431      * in a frozen state at start up, do it now
 432      */
 433     if (s->deferred_options.log_filepath) {
 434         s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
 435         if (!s->log_file) {
 436             s->log_file = stderr;
 437         }
 438         s->deferred_options.log_filepath = NULL;
 439     }
 440     ga_enable_logging(s);
 441     g_warning("logging re-enabled due to filesystem unfreeze");
 442     if (s->deferred_options.pid_filepath) {
 443         if (!ga_open_pidfile(s->deferred_options.pid_filepath)) {
 444             g_warning("failed to create/open pid file");
 445         }
 446         s->deferred_options.pid_filepath = NULL;
 447     }
 448
 449     /* enable all disabled, non-blacklisted commands */
 450     qmp_for_each_command(ga_enable_non_blacklisted, s->blacklist);
 451     s->frozen = false;
 452     if (!ga_delete_file(s->state_filepath_isfrozen)) {
 453         g_warning("unable to delete %s, fsfreeze may not function properly",
 454                   s->state_filepath_isfrozen);
 455     }
 456 }
 457
 458 #ifdef CONFIG_FSFREEZE
 459 const char *ga_fsfreeze_hook(GAState *s)
 460 {
 461     return s->fsfreeze_hook;
 462 }
 463 #endif
 464
 465 static void become_daemon(const char *pidfile)
 466 {
 467 #ifndef _WIN32
 468     pid_t pid, sid;
 469
 470     pid = fork();
 471     if (pid < 0) {
 472         exit(EXIT_FAILURE);
 473     }
 474     if (pid > 0) {
 475         exit(EXIT_SUCCESS);
 476     }
 477
 478     if (pidfile) {
 479         if (!ga_open_pidfile(pidfile)) {
 480             g_critical("failed to create pidfile");
 481             exit(EXIT_FAILURE);
 482         }
 483     }
 484
 485     umask(S_IRWXG | S_IRWXO);
 486     sid = setsid();
 487     if (sid < 0) {
 488         goto fail;
 489     }
 490     if ((chdir("/")) < 0) {
 491         goto fail;
 492     }
 493
 494     reopen_fd_to_null(STDIN_FILENO);
 495     reopen_fd_to_null(STDOUT_FILENO);
 496     reopen_fd_to_null(STDERR_FILENO);
 497     return;
 498
 499 fail:
 500     if (pidfile) {
 501         unlink(pidfile);
 502     }
 503     g_critical("failed to daemonize");
 504     exit(EXIT_FAILURE);
 505 #endif
 506 }
 507
 508 static int send_response(GAState *s, QObject *payload)
 509 {
 510     const char *buf;
 511     QString *payload_qstr, *response_qstr;
 512     GIOStatus status;
 513
 514     g_assert(payload && s->channel);
 515
 516     payload_qstr = qobject_to_json(payload);
 517     if (!payload_qstr) {
 518         return -EINVAL;
 519     }
 520
 521     if (s->delimit_response) {
 522         s->delimit_response = false;
 523         response_qstr = qstring_new();
 524         qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
 525         qstring_append(response_qstr, qstring_get_str(payload_qstr));
 526         QDECREF(payload_qstr);
 527     } else {
 528         response_qstr = payload_qstr;
 529     }
 530
 531     qstring_append_chr(response_qstr, '\n');
 532     buf = qstring_get_str(response_qstr);
 533     status = ga_channel_write_all(s->channel, buf, strlen(buf));
 534     QDECREF(response_qstr);
 535     if (status != G_IO_STATUS_NORMAL) {
 536         return -EIO;
 537     }
 538
 539     return 0;
 540 }
 541
 542 static void process_command(GAState *s, QDict *req)
 543 {
 544     QObject *rsp = NULL;
 545     int ret;
 546
 547     g_assert(req);
 548     g_debug("processing command");
 549     rsp = qmp_dispatch(QOBJECT(req));
 550     if (rsp) {
 551         ret = send_response(s, rsp);
 552         if (ret) {
 553             g_warning("error sending response: %s", strerror(ret));
 554         }
 555         qobject_decref(rsp);
 556     }
 557 }
 558
 559 /* handle requests/control events coming in over the channel */
 560 static void process_event(JSONMessageParser *parser, QList *tokens)
 561 {
 562     GAState *s = container_of(parser, GAState, parser);
 563     QObject *obj;
 564     QDict *qdict;
 565     Error *err = NULL;
 566     int ret;
 567
 568     g_assert(s && parser);
 569
 570     g_debug("process_event: called");
 571     obj = json_parser_parse_err(tokens, NULL, &err);
 572     if (err || !obj || qobject_type(obj) != QTYPE_QDICT) {
 573         qobject_decref(obj);
 574         qdict = qdict_new();
 575         if (!err) {
 576             g_warning("failed to parse event: unknown error");
 577             error_set(&err, QERR_JSON_PARSING);
 578         } else {
 579             g_warning("failed to parse event: %s", error_get_pretty(err));
 580         }
 581         qdict_put_obj(qdict, "error", qmp_build_error_object(err));
 582         error_free(err);
 583     } else {
 584         qdict = qobject_to_qdict(obj);
 585     }
 586
 587     g_assert(qdict);
 588
 589     /* handle host->guest commands */
 590     if (qdict_haskey(qdict, "execute")) {
 591         process_command(s, qdict);
 592     } else {
 593         if (!qdict_haskey(qdict, "error")) {
 594             QDECREF(qdict);
 595             qdict = qdict_new();
 596             g_warning("unrecognized payload format");
 597             error_set(&err, QERR_UNSUPPORTED);
 598             qdict_put_obj(qdict, "error", qmp_build_error_object(err));
 599             error_free(err);
 600         }
 601         ret = send_response(s, QOBJECT(qdict));
 602         if (ret) {
 603             g_warning("error sending error response: %s", strerror(ret));
 604         }
 605     }
 606
 607     QDECREF(qdict);
 608 }
 609
 610 /* false return signals GAChannel to close the current client connection */
 611 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 612 {
 613     GAState *s = data;
 614     gchar buf[QGA_READ_COUNT_DEFAULT+1];
 615     gsize count;
 616     GError *err = NULL;
 617     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 618     if (err != NULL) {
 619         g_warning("error reading channel: %s", err->message);
 620         g_error_free(err);
 621         return false;
 622     }
 623     switch (status) {
 624     case G_IO_STATUS_ERROR:
 625         g_warning("error reading channel");
 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 {
 655     GAChannelMethod channel_method;
 656
 657     if (method == NULL) {
 658         method = "virtio-serial";
 659     }
 660
 661     if (path == NULL) {
 662         if (strcmp(method, "virtio-serial") != 0) {
 663             g_critical("must specify a path for this channel");
 664             return false;
 665         }
 666         /* try the default path for the virtio-serial port */
 667         path = QGA_VIRTIO_PATH_DEFAULT;
 668     }
 669
 670     if (strcmp(method, "virtio-serial") == 0) {
 671         s->virtio = true; /* virtio requires special handling in some cases */
 672         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 673     } else if (strcmp(method, "isa-serial") == 0) {
 674         channel_method = GA_CHANNEL_ISA_SERIAL;
 675     } else if (strcmp(method, "unix-listen") == 0) {
 676         channel_method = GA_CHANNEL_UNIX_LISTEN;
 677     } else {
 678         g_critical("unsupported channel method/type: %s", method);
 679         return false;
 680     }
 681
 682     s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
 683     if (!s->channel) {
 684         g_critical("failed to create guest agent channel");
 685         return false;
 686     }
 687
 688     return true;
 689 }
 690
 691 #ifdef _WIN32
 692 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 693                                   LPVOID ctx)
 694 {
 695     DWORD ret = NO_ERROR;
 696     GAService *service = &ga_state->service;
 697
 698     switch (ctrl)
 699     {
 700         case SERVICE_CONTROL_STOP:
 701         case SERVICE_CONTROL_SHUTDOWN:
 702             quit_handler(SIGTERM);
 703             service->status.dwCurrentState = SERVICE_STOP_PENDING;
 704             SetServiceStatus(service->status_handle, &service->status);
 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     SetServiceStatus(service->status_handle, &service->status);
 733
 734     g_main_loop_run(ga_state->main_loop);
 735
 736     service->status.dwCurrentState = SERVICE_STOPPED;
 737     SetServiceStatus(service->status_handle, &service->status);
 738 }
 739 #endif
 740
 741 static void set_persistent_state_defaults(GAPersistentState *pstate)
 742 {
 743     g_assert(pstate);
 744     pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
 745 }
 746
 747 static void persistent_state_from_keyfile(GAPersistentState *pstate,
 748                                           GKeyFile *keyfile)
 749 {
 750     g_assert(pstate);
 751     g_assert(keyfile);
 752     /* if any fields are missing, either because the file was tampered with
 753      * by agents of chaos, or because the field wasn't present at the time the
 754      * file was created, the best we can ever do is start over with the default
 755      * values. so load them now, and ignore any errors in accessing key-value
 756      * pairs
 757      */
 758     set_persistent_state_defaults(pstate);
 759
 760     if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
 761         pstate->fd_counter =
 762             g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
 763     }
 764 }
 765
 766 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
 767                                         GKeyFile *keyfile)
 768 {
 769     g_assert(pstate);
 770     g_assert(keyfile);
 771
 772     g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
 773 }
 774
 775 static gboolean write_persistent_state(const GAPersistentState *pstate,
 776                                        const gchar *path)
 777 {
 778     GKeyFile *keyfile = g_key_file_new();
 779     GError *gerr = NULL;
 780     gboolean ret = true;
 781     gchar *data = NULL;
 782     gsize data_len;
 783
 784     g_assert(pstate);
 785
 786     persistent_state_to_keyfile(pstate, keyfile);
 787     data = g_key_file_to_data(keyfile, &data_len, &gerr);
 788     if (gerr) {
 789         g_critical("failed to convert persistent state to string: %s",
 790                    gerr->message);
 791         ret = false;
 792         goto out;
 793     }
 794
 795     g_file_set_contents(path, data, data_len, &gerr);
 796     if (gerr) {
 797         g_critical("failed to write persistent state to %s: %s",
 798                     path, gerr->message);
 799         ret = false;
 800         goto out;
 801     }
 802
 803 out:
 804     if (gerr) {
 805         g_error_free(gerr);
 806     }
 807     if (keyfile) {
 808         g_key_file_free(keyfile);
 809     }
 810     g_free(data);
 811     return ret;
 812 }
 813
 814 static gboolean read_persistent_state(GAPersistentState *pstate,
 815                                       const gchar *path, gboolean frozen)
 816 {
 817     GKeyFile *keyfile = NULL;
 818     GError *gerr = NULL;
 819     struct stat st;
 820     gboolean ret = true;
 821
 822     g_assert(pstate);
 823
 824     if (stat(path, &st) == -1) {
 825         /* it's okay if state file doesn't exist, but any other error
 826          * indicates a permissions issue or some other misconfiguration
 827          * that we likely won't be able to recover from.
 828          */
 829         if (errno != ENOENT) {
 830             g_critical("unable to access state file at path %s: %s",
 831                        path, strerror(errno));
 832             ret = false;
 833             goto out;
 834         }
 835
 836         /* file doesn't exist. initialize state to default values and
 837          * attempt to save now. (we could wait till later when we have
 838          * modified state we need to commit, but if there's a problem,
 839          * such as a missing parent directory, we want to catch it now)
 840          *
 841          * there is a potential scenario where someone either managed to
 842          * update the agent from a version that didn't use a key store
 843          * while qemu-ga thought the filesystem was frozen, or
 844          * deleted the key store prior to issuing a fsfreeze, prior
 845          * to restarting the agent. in this case we go ahead and defer
 846          * initial creation till we actually have modified state to
 847          * write, otherwise fail to recover from freeze.
 848          */
 849         set_persistent_state_defaults(pstate);
 850         if (!frozen) {
 851             ret = write_persistent_state(pstate, path);
 852             if (!ret) {
 853                 g_critical("unable to create state file at path %s", path);
 854                 ret = false;
 855                 goto out;
 856             }
 857         }
 858         ret = true;
 859         goto out;
 860     }
 861
 862     keyfile = g_key_file_new();
 863     g_key_file_load_from_file(keyfile, path, 0, &gerr);
 864     if (gerr) {
 865         g_critical("error loading persistent state from path: %s, %s",
 866                    path, gerr->message);
 867         ret = false;
 868         goto out;
 869     }
 870
 871     persistent_state_from_keyfile(pstate, keyfile);
 872
 873 out:
 874     if (keyfile) {
 875         g_key_file_free(keyfile);
 876     }
 877     if (gerr) {
 878         g_error_free(gerr);
 879     }
 880
 881     return ret;
 882 }
 883
 884 int64_t ga_get_fd_handle(GAState *s, Error **errp)
 885 {
 886     int64_t handle;
 887
 888     g_assert(s->pstate_filepath);
 889     /* we blacklist commands and avoid operations that potentially require
 890      * writing to disk when we're in a frozen state. this includes opening
 891      * new files, so we should never get here in that situation
 892      */
 893     g_assert(!ga_is_frozen(s));
 894
 895     handle = s->pstate.fd_counter++;
 896
 897     /* This should never happen on a reasonable timeframe, as guest-file-open
 898      * would have to be issued 2^63 times */
 899     if (s->pstate.fd_counter == INT64_MAX) {
 900         abort();
 901     }
 902
 903     if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
 904         error_setg(errp, "failed to commit persistent state to disk");
 905     }
 906
 907     return handle;
 908 }
 909
 910 static void ga_print_cmd(QmpCommand *cmd, void *opaque)
 911 {
 912     printf("%s\n", qmp_command_name(cmd));
 913 }
 914
 915 int main(int argc, char **argv)
 916 {
 917     const char *sopt = "hVvdm:p:l:f:F::b:s:t:";
 918     const char *method = NULL, *path = NULL;
 919     const char *log_filepath = NULL;
 920     const char *pid_filepath;
 921 #ifdef CONFIG_FSFREEZE
 922     const char *fsfreeze_hook = NULL;
 923 #endif
 924     const char *state_dir;
 925 #ifdef _WIN32
 926     const char *service = NULL;
 927 #endif
 928     const struct option lopt[] = {
 929         { "help", 0, NULL, 'h' },
 930         { "version", 0, NULL, 'V' },
 931         { "logfile", 1, NULL, 'l' },
 932         { "pidfile", 1, NULL, 'f' },
 933 #ifdef CONFIG_FSFREEZE
 934         { "fsfreeze-hook", 2, NULL, 'F' },
 935 #endif
 936         { "verbose", 0, NULL, 'v' },
 937         { "method", 1, NULL, 'm' },
 938         { "path", 1, NULL, 'p' },
 939         { "daemonize", 0, NULL, 'd' },
 940         { "blacklist", 1, NULL, 'b' },
 941 #ifdef _WIN32
 942         { "service", 1, NULL, 's' },
 943 #endif
 944         { "statedir", 1, NULL, 't' },
 945         { NULL, 0, NULL, 0 }
 946     };
 947     int opt_ind = 0, ch, daemonize = 0, i, j, len;
 948     GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
 949     GList *blacklist = NULL;
 950     GAState *s;
 951
 952     module_call_init(MODULE_INIT_QAPI);
 953
 954     init_dfl_pathnames();
 955     pid_filepath = dfl_pathnames.pidfile;
 956     state_dir = dfl_pathnames.state_dir;
 957
 958     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 959         switch (ch) {
 960         case 'm':
 961             method = optarg;
 962             break;
 963         case 'p':
 964             path = optarg;
 965             break;
 966         case 'l':
 967             log_filepath = optarg;
 968             break;
 969         case 'f':
 970             pid_filepath = optarg;
 971             break;
 972 #ifdef CONFIG_FSFREEZE
 973         case 'F':
 974             fsfreeze_hook = optarg ? optarg : QGA_FSFREEZE_HOOK_DEFAULT;
 975             break;
 976 #endif
 977         case 't':
 978              state_dir = optarg;
 979              break;
 980         case 'v':
 981             /* enable all log levels */
 982             log_level = G_LOG_LEVEL_MASK;
 983             break;
 984         case 'V':
 985             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
 986             return 0;
 987         case 'd':
 988             daemonize = 1;
 989             break;
 990         case 'b': {
 991             if (is_help_option(optarg)) {
 992                 qmp_for_each_command(ga_print_cmd, NULL);
 993                 return 0;
 994             }
 995             for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
 996                 if (optarg[i] == ',') {
 997                     optarg[i] = 0;
 998                     blacklist = g_list_append(blacklist, &optarg[j]);
 999                     j = i + 1;
1000                 }
1001             }
1002             if (j < i) {
1003                 blacklist = g_list_append(blacklist, &optarg[j]);
1004             }
1005             break;
1006         }
1007 #ifdef _WIN32
1008         case 's':
1009             service = optarg;
1010             if (strcmp(service, "install") == 0) {
1011                 const char *fixed_state_dir;
1012
1013                 /* If the user passed the "-t" option, we save that state dir
1014                  * in the service. Otherwise we let the service fetch the state
1015                  * dir from the environment when it starts.
1016                  */
1017                 fixed_state_dir = (state_dir == dfl_pathnames.state_dir) ?
1018                                   NULL :
1019                                   state_dir;
1020                 if (ga_install_vss_provider()) {
1021                     return EXIT_FAILURE;
1022                 }
1023                 if (ga_install_service(path, log_filepath, fixed_state_dir)) {
1024                     return EXIT_FAILURE;
1025                 }
1026                 return 0;
1027             } else if (strcmp(service, "uninstall") == 0) {
1028                 ga_uninstall_vss_provider();
1029                 return ga_uninstall_service();
1030             } else {
1031                 printf("Unknown service command.\n");
1032                 return EXIT_FAILURE;
1033             }
1034             break;
1035 #endif
1036         case 'h':
1037             usage(argv[0]);
1038             return 0;
1039         case '?':
1040             g_print("Unknown option, try '%s --help' for more information.\n",
1041                     argv[0]);
1042             return EXIT_FAILURE;
1043         }
1044     }
1045
1046 #ifdef _WIN32
1047     /* On win32 the state directory is application specific (be it the default
1048      * or a user override). We got past the command line parsing; let's create
1049      * the directory (with any intermediate directories). If we run into an
1050      * error later on, we won't try to clean up the directory, it is considered
1051      * persistent.
1052      */
1053     if (g_mkdir_with_parents(state_dir, S_IRWXU) == -1) {
1054         g_critical("unable to create (an ancestor of) the state directory"
1055                    " '%s': %s", state_dir, strerror(errno));
1056         return EXIT_FAILURE;
1057     }
1058 #endif
1059
1060     s = g_malloc0(sizeof(GAState));
1061     s->log_level = log_level;
1062     s->log_file = stderr;
1063 #ifdef CONFIG_FSFREEZE
1064     s->fsfreeze_hook = fsfreeze_hook;
1065 #endif
1066     g_log_set_default_handler(ga_log, s);
1067     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1068     ga_enable_logging(s);
1069     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1070                                                  state_dir);
1071     s->pstate_filepath = g_strdup_printf("%s/qga.state", state_dir);
1072     s->frozen = false;
1073
1074 #ifndef _WIN32
1075     /* check if a previous instance of qemu-ga exited with filesystems' state
1076      * marked as frozen. this could be a stale value (a non-qemu-ga process
1077      * or reboot may have since unfrozen them), but better to require an
1078      * uneeded unfreeze than to risk hanging on start-up
1079      */
1080     struct stat st;
1081     if (stat(s->state_filepath_isfrozen, &st) == -1) {
1082         /* it's okay if the file doesn't exist, but if we can't access for
1083          * some other reason, such as permissions, there's a configuration
1084          * that needs to be addressed. so just bail now before we get into
1085          * more trouble later
1086          */
1087         if (errno != ENOENT) {
1088             g_critical("unable to access state file at path %s: %s",
1089                        s->state_filepath_isfrozen, strerror(errno));
1090             return EXIT_FAILURE;
1091         }
1092     } else {
1093         g_warning("previous instance appears to have exited with frozen"
1094                   " filesystems. deferring logging/pidfile creation and"
1095                   " disabling non-fsfreeze-safe commands until"
1096                   " guest-fsfreeze-thaw is issued, or filesystems are"
1097                   " manually unfrozen and the file %s is removed",
1098                   s->state_filepath_isfrozen);
1099         s->frozen = true;
1100     }
1101 #endif
1102
1103     if (ga_is_frozen(s)) {
1104         if (daemonize) {
1105             /* delay opening/locking of pidfile till filesystem are unfrozen */
1106             s->deferred_options.pid_filepath = pid_filepath;
1107             become_daemon(NULL);
1108         }
1109         if (log_filepath) {
1110             /* delay opening the log file till filesystems are unfrozen */
1111             s->deferred_options.log_filepath = log_filepath;
1112         }
1113         ga_disable_logging(s);
1114         qmp_for_each_command(ga_disable_non_whitelisted, NULL);
1115     } else {
1116         if (daemonize) {
1117             become_daemon(pid_filepath);
1118         }
1119         if (log_filepath) {
1120             FILE *log_file = ga_open_logfile(log_filepath);
1121             if (!log_file) {
1122                 g_critical("unable to open specified log file: %s",
1123                            strerror(errno));
1124                 goto out_bad;
1125             }
1126             s->log_file = log_file;
1127         }
1128     }
1129
1130     /* load persistent state from disk */
1131     if (!read_persistent_state(&s->pstate,
1132                                s->pstate_filepath,
1133                                ga_is_frozen(s))) {
1134         g_critical("failed to load persistent state");
1135         goto out_bad;
1136     }
1137
1138     if (blacklist) {
1139         s->blacklist = blacklist;
1140         do {
1141             g_debug("disabling command: %s", (char *)blacklist->data);
1142             qmp_disable_command(blacklist->data);
1143             blacklist = g_list_next(blacklist);
1144         } while (blacklist);
1145     }
1146     s->command_state = ga_command_state_new();
1147     ga_command_state_init(s, s->command_state);
1148     ga_command_state_init_all(s->command_state);
1149     json_message_parser_init(&s->parser, process_event);
1150     ga_state = s;
1151 #ifndef _WIN32
1152     if (!register_signal_handlers()) {
1153         g_critical("failed to register signal handlers");
1154         goto out_bad;
1155     }
1156 #endif
1157
1158     s->main_loop = g_main_loop_new(NULL, false);
1159     if (!channel_init(ga_state, method, path)) {
1160         g_critical("failed to initialize guest agent channel");
1161         goto out_bad;
1162     }
1163 #ifndef _WIN32
1164     g_main_loop_run(ga_state->main_loop);
1165 #else
1166     if (daemonize) {
1167         SERVICE_TABLE_ENTRY service_table[] = {
1168             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1169         StartServiceCtrlDispatcher(service_table);
1170     } else {
1171         g_main_loop_run(ga_state->main_loop);
1172     }
1173 #endif
1174
1175     ga_command_state_cleanup_all(ga_state->command_state);
1176     ga_channel_free(ga_state->channel);
1177
1178     if (daemonize) {
1179         unlink(pid_filepath);
1180     }
1181     return 0;
1182
1183 out_bad:
1184     if (daemonize) {
1185         unlink(pid_filepath);
1186     }
1187     return EXIT_FAILURE;
1188 }