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 #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
  51 #else
  52 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
  53 #define QGA_STATE_RELATIVE_DIR  "qemu-ga"
  54 #define QGA_SERIAL_PATH_DEFAULT "COM1"
  55 #endif
  56 #ifdef CONFIG_FSFREEZE
  57 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
  58 #endif
  59 #define QGA_SENTINEL_BYTE 0xFF
  60
  61 static struct {
  62     const char *state_dir;
  63     const char *pidfile;
  64 } dfl_pathnames;
  65
  66 typedef struct GAPersistentState {
  67 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
  68     int64_t fd_counter;
  69 } GAPersistentState;
  70
  71 struct GAState {
  72     JSONMessageParser parser;
  73     GMainLoop *main_loop;
  74     GAChannel *channel;
  75     bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
  76     GACommandState *command_state;
  77     GLogLevelFlags log_level;
  78     FILE *log_file;
  79     bool logging_enabled;
  80 #ifdef _WIN32
  81     GAService service;
  82 #endif
  83     bool delimit_response;
  84     bool frozen;
  85     GList *blacklist;
  86     const char *state_filepath_isfrozen;
  87     struct {
  88         const char *log_filepath;
  89         const char *pid_filepath;
  90     } deferred_options;
  91 #ifdef CONFIG_FSFREEZE
  92     const char *fsfreeze_hook;
  93 #endif
  94     const gchar *pstate_filepath;
  95     GAPersistentState pstate;
  96 };
  97
  98 struct GAState *ga_state;
  99
 100 /* commands that are safe to issue while filesystems are frozen */
 101 static const char *ga_freeze_whitelist[] = {
 102     "guest-ping",
 103     "guest-info",
 104     "guest-sync",
 105     "guest-sync-delimited",
 106     "guest-fsfreeze-status",
 107     "guest-fsfreeze-thaw",
 108     NULL
 109 };
 110
 111 #ifdef _WIN32
 112 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 113                                   LPVOID ctx);
 114 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
 115 #endif
 116
 117 static void
 118 init_dfl_pathnames(void)
 119 {
 120     g_assert(dfl_pathnames.state_dir == NULL);
 121     g_assert(dfl_pathnames.pidfile == NULL);
 122     dfl_pathnames.state_dir = qemu_get_local_state_pathname(
 123       QGA_STATE_RELATIVE_DIR);
 124     dfl_pathnames.pidfile   = qemu_get_local_state_pathname(
 125       QGA_STATE_RELATIVE_DIR G_DIR_SEPARATOR_S "qemu-ga.pid");
 126 }
 127
 128 static void quit_handler(int sig)
 129 {
 130     /* if we're frozen, don't exit unless we're absolutely forced to,
 131      * because it's basically impossible for graceful exit to complete
 132      * unless all log/pid files are on unfreezable filesystems. there's
 133      * also a very likely chance killing the agent before unfreezing
 134      * the filesystems is a mistake (or will be viewed as one later).
 135      */
 136     if (ga_is_frozen(ga_state)) {
 137         return;
 138     }
 139     g_debug("received signal num %d, quitting", sig);
 140
 141     if (g_main_loop_is_running(ga_state->main_loop)) {
 142         g_main_loop_quit(ga_state->main_loop);
 143     }
 144 }
 145
 146 #ifndef _WIN32
 147 static gboolean register_signal_handlers(void)
 148 {
 149     struct sigaction sigact;
 150     int ret;
 151
 152     memset(&sigact, 0, sizeof(struct sigaction));
 153     sigact.sa_handler = quit_handler;
 154
 155     ret = sigaction(SIGINT, &sigact, NULL);
 156     if (ret == -1) {
 157         g_error("error configuring signal handler: %s", strerror(errno));
 158     }
 159     ret = sigaction(SIGTERM, &sigact, NULL);
 160     if (ret == -1) {
 161         g_error("error configuring signal handler: %s", strerror(errno));
 162     }
 163
 164     return true;
 165 }
 166
 167 /* TODO: use this in place of all post-fork() fclose(std*) callers */
 168 void reopen_fd_to_null(int fd)
 169 {
 170     int nullfd;
 171
 172     nullfd = open("/dev/null", O_RDWR);
 173     if (nullfd < 0) {
 174         return;
 175     }
 176
 177     dup2(nullfd, fd);
 178
 179     if (nullfd != fd) {
 180         close(nullfd);
 181     }
 182 }
 183 #endif
 184
 185 static void usage(const char *cmd)
 186 {
 187     printf(
 188 "Usage: %s [-m <method> -p <path>] [<options>]\n"
 189 "QEMU Guest Agent %s\n"
 190 "\n"
 191 "  -m, --method      transport method: one of unix-listen, virtio-serial, or\n"
 192 "                    isa-serial (virtio-serial is the default)\n"
 193 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
 194 "                    %s,\n"
 195 "                    the default for isa-serial is:\n"
 196 "                    %s)\n"
 197 "  -l, --logfile     set logfile path, logs to stderr by default\n"
 198 "  -f, --pidfile     specify pidfile (default is %s)\n"
 199 #ifdef CONFIG_FSFREEZE
 200 "  -F, --fsfreeze-hook\n"
 201 "                    enable fsfreeze hook. Accepts an optional argument that\n"
 202 "                    specifies script to run on freeze/thaw. Script will be\n"
 203 "                    called with 'freeze'/'thaw' arguments accordingly.\n"
 204 "                    (default is %s)\n"
 205 "                    If using -F with an argument, do not follow -F with a\n"
 206 "                    space.\n"
 207 "                    (for example: -F/var/run/fsfreezehook.sh)\n"
 208 #endif
 209 "  -t, --statedir    specify dir to store state information (absolute paths\n"
 210 "                    only, default is %s)\n"
 211 "  -v, --verbose     log extra debugging information\n"
 212 "  -V, --version     print version information and exit\n"
 213 "  -d, --daemonize   become a daemon\n"
 214 #ifdef _WIN32
 215 "  -s, --service     service commands: install, uninstall\n"
 216 #endif
 217 "  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\"\n"
 218 "                    to list available RPCs)\n"
 219 "  -h, --help        display this help and exit\n"
 220 "\n"
 221 "Report bugs to <mdroth@linux.vnet.ibm.com>\n"
 222     , cmd, QEMU_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT,
 223     dfl_pathnames.pidfile,
 224 #ifdef CONFIG_FSFREEZE
 225     QGA_FSFREEZE_HOOK_DEFAULT,
 226 #endif
 227     dfl_pathnames.state_dir);
 228 }
 229
 230 static const char *ga_log_level_str(GLogLevelFlags level)
 231 {
 232     switch (level & G_LOG_LEVEL_MASK) {
 233         case G_LOG_LEVEL_ERROR:
 234             return "error";
 235         case G_LOG_LEVEL_CRITICAL:
 236             return "critical";
 237         case G_LOG_LEVEL_WARNING:
 238             return "warning";
 239         case G_LOG_LEVEL_MESSAGE:
 240             return "message";
 241         case G_LOG_LEVEL_INFO:
 242             return "info";
 243         case G_LOG_LEVEL_DEBUG:
 244             return "debug";
 245         default:
 246             return "user";
 247     }
 248 }
 249
 250 bool ga_logging_enabled(GAState *s)
 251 {
 252     return s->logging_enabled;
 253 }
 254
 255 void ga_disable_logging(GAState *s)
 256 {
 257     s->logging_enabled = false;
 258 }
 259
 260 void ga_enable_logging(GAState *s)
 261 {
 262     s->logging_enabled = true;
 263 }
 264
 265 static void ga_log(const gchar *domain, GLogLevelFlags level,
 266                    const gchar *msg, gpointer opaque)
 267 {
 268     GAState *s = opaque;
 269     GTimeVal time;
 270     const char *level_str = ga_log_level_str(level);
 271
 272     if (!ga_logging_enabled(s)) {
 273         return;
 274     }
 275
 276     level &= G_LOG_LEVEL_MASK;
 277 #ifndef _WIN32
 278     if (domain && strcmp(domain, "syslog") == 0) {
 279         syslog(LOG_INFO, "%s: %s", level_str, msg);
 280     } else if (level & s->log_level) {
 281 #else
 282     if (level & s->log_level) {
 283 #endif
 284         g_get_current_time(&time);
 285         fprintf(s->log_file,
 286                 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
 287         fflush(s->log_file);
 288     }
 289 }
 290
 291 void ga_set_response_delimited(GAState *s)
 292 {
 293     s->delimit_response = true;
 294 }
 295
 296 static FILE *ga_open_logfile(const char *logfile)
 297 {
 298     FILE *f;
 299
 300     f = fopen(logfile, "a");
 301     if (!f) {
 302         return NULL;
 303     }
 304
 305     qemu_set_cloexec(fileno(f));
 306     return f;
 307 }
 308
 309 #ifndef _WIN32
 310 static bool ga_open_pidfile(const char *pidfile)
 311 {
 312     int pidfd;
 313     char pidstr[32];
 314
 315     pidfd = qemu_open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
 316     if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) {
 317         g_critical("Cannot lock pid file, %s", strerror(errno));
 318         if (pidfd != -1) {
 319             close(pidfd);
 320         }
 321         return false;
 322     }
 323
 324     if (ftruncate(pidfd, 0)) {
 325         g_critical("Failed to truncate pid file");
 326         goto fail;
 327     }
 328     snprintf(pidstr, sizeof(pidstr), "%d\n", getpid());
 329     if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
 330         g_critical("Failed to write pid file");
 331         goto fail;
 332     }
 333
 334     /* keep pidfile open & locked forever */
 335     return true;
 336
 337 fail:
 338     unlink(pidfile);
 339     close(pidfd);
 340     return false;
 341 }
 342 #else /* _WIN32 */
 343 static bool ga_open_pidfile(const char *pidfile)
 344 {
 345     return true;
 346 }
 347 #endif
 348
 349 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
 350 {
 351     return strcmp(str1, str2);
 352 }
 353
 354 /* disable commands that aren't safe for fsfreeze */
 355 static void ga_disable_non_whitelisted(QmpCommand *cmd, void *opaque)
 356 {
 357     bool whitelisted = false;
 358     int i = 0;
 359     const char *name = qmp_command_name(cmd);
 360
 361     while (ga_freeze_whitelist[i] != NULL) {
 362         if (strcmp(name, ga_freeze_whitelist[i]) == 0) {
 363             whitelisted = true;
 364         }
 365         i++;
 366     }
 367     if (!whitelisted) {
 368         g_debug("disabling command: %s", name);
 369         qmp_disable_command(name);
 370     }
 371 }
 372
 373 /* [re-]enable all commands, except those explicitly blacklisted by user */
 374 static void ga_enable_non_blacklisted(QmpCommand *cmd, void *opaque)
 375 {
 376     GList *blacklist = opaque;
 377     const char *name = qmp_command_name(cmd);
 378
 379     if (g_list_find_custom(blacklist, name, ga_strcmp) == NULL &&
 380         !qmp_command_is_enabled(cmd)) {
 381         g_debug("enabling command: %s", name);
 382         qmp_enable_command(name);
 383     }
 384 }
 385
 386 static bool ga_create_file(const char *path)
 387 {
 388     int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
 389     if (fd == -1) {
 390         g_warning("unable to open/create file %s: %s", path, strerror(errno));
 391         return false;
 392     }
 393     close(fd);
 394     return true;
 395 }
 396
 397 static bool ga_delete_file(const char *path)
 398 {
 399     int ret = unlink(path);
 400     if (ret == -1) {
 401         g_warning("unable to delete file: %s: %s", path, strerror(errno));
 402         return false;
 403     }
 404
 405     return true;
 406 }
 407
 408 bool ga_is_frozen(GAState *s)
 409 {
 410     return s->frozen;
 411 }
 412
 413 void ga_set_frozen(GAState *s)
 414 {
 415     if (ga_is_frozen(s)) {
 416         return;
 417     }
 418     /* disable all non-whitelisted (for frozen state) commands */
 419     qmp_for_each_command(ga_disable_non_whitelisted, NULL);
 420     g_warning("disabling logging due to filesystem freeze");
 421     ga_disable_logging(s);
 422     s->frozen = true;
 423     if (!ga_create_file(s->state_filepath_isfrozen)) {
 424         g_warning("unable to create %s, fsfreeze may not function properly",
 425                   s->state_filepath_isfrozen);
 426     }
 427 }
 428
 429 void ga_unset_frozen(GAState *s)
 430 {
 431     if (!ga_is_frozen(s)) {
 432         return;
 433     }
 434
 435     /* if we delayed creation/opening of pid/log files due to being
 436      * in a frozen state at start up, do it now
 437      */
 438     if (s->deferred_options.log_filepath) {
 439         s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
 440         if (!s->log_file) {
 441             s->log_file = stderr;
 442         }
 443         s->deferred_options.log_filepath = NULL;
 444     }
 445     ga_enable_logging(s);
 446     g_warning("logging re-enabled due to filesystem unfreeze");
 447     if (s->deferred_options.pid_filepath) {
 448         if (!ga_open_pidfile(s->deferred_options.pid_filepath)) {
 449             g_warning("failed to create/open pid file");
 450         }
 451         s->deferred_options.pid_filepath = NULL;
 452     }
 453
 454     /* enable all disabled, non-blacklisted commands */
 455     qmp_for_each_command(ga_enable_non_blacklisted, s->blacklist);
 456     s->frozen = false;
 457     if (!ga_delete_file(s->state_filepath_isfrozen)) {
 458         g_warning("unable to delete %s, fsfreeze may not function properly",
 459                   s->state_filepath_isfrozen);
 460     }
 461 }
 462
 463 #ifdef CONFIG_FSFREEZE
 464 const char *ga_fsfreeze_hook(GAState *s)
 465 {
 466     return s->fsfreeze_hook;
 467 }
 468 #endif
 469
 470 static void become_daemon(const char *pidfile)
 471 {
 472 #ifndef _WIN32
 473     pid_t pid, sid;
 474
 475     pid = fork();
 476     if (pid < 0) {
 477         exit(EXIT_FAILURE);
 478     }
 479     if (pid > 0) {
 480         exit(EXIT_SUCCESS);
 481     }
 482
 483     if (pidfile) {
 484         if (!ga_open_pidfile(pidfile)) {
 485             g_critical("failed to create pidfile");
 486             exit(EXIT_FAILURE);
 487         }
 488     }
 489
 490     umask(S_IRWXG | S_IRWXO);
 491     sid = setsid();
 492     if (sid < 0) {
 493         goto fail;
 494     }
 495     if ((chdir("/")) < 0) {
 496         goto fail;
 497     }
 498
 499     reopen_fd_to_null(STDIN_FILENO);
 500     reopen_fd_to_null(STDOUT_FILENO);
 501     reopen_fd_to_null(STDERR_FILENO);
 502     return;
 503
 504 fail:
 505     if (pidfile) {
 506         unlink(pidfile);
 507     }
 508     g_critical("failed to daemonize");
 509     exit(EXIT_FAILURE);
 510 #endif
 511 }
 512
 513 static int send_response(GAState *s, QObject *payload)
 514 {
 515     const char *buf;
 516     QString *payload_qstr, *response_qstr;
 517     GIOStatus status;
 518
 519     g_assert(payload && s->channel);
 520
 521     payload_qstr = qobject_to_json(payload);
 522     if (!payload_qstr) {
 523         return -EINVAL;
 524     }
 525
 526     if (s->delimit_response) {
 527         s->delimit_response = false;
 528         response_qstr = qstring_new();
 529         qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
 530         qstring_append(response_qstr, qstring_get_str(payload_qstr));
 531         QDECREF(payload_qstr);
 532     } else {
 533         response_qstr = payload_qstr;
 534     }
 535
 536     qstring_append_chr(response_qstr, '\n');
 537     buf = qstring_get_str(response_qstr);
 538     status = ga_channel_write_all(s->channel, buf, strlen(buf));
 539     QDECREF(response_qstr);
 540     if (status != G_IO_STATUS_NORMAL) {
 541         return -EIO;
 542     }
 543
 544     return 0;
 545 }
 546
 547 static void process_command(GAState *s, QDict *req)
 548 {
 549     QObject *rsp = NULL;
 550     int ret;
 551
 552     g_assert(req);
 553     g_debug("processing command");
 554     rsp = qmp_dispatch(QOBJECT(req));
 555     if (rsp) {
 556         ret = send_response(s, rsp);
 557         if (ret) {
 558             g_warning("error sending response: %s", strerror(ret));
 559         }
 560         qobject_decref(rsp);
 561     }
 562 }
 563
 564 /* handle requests/control events coming in over the channel */
 565 static void process_event(JSONMessageParser *parser, QList *tokens)
 566 {
 567     GAState *s = container_of(parser, GAState, parser);
 568     QObject *obj;
 569     QDict *qdict;
 570     Error *err = NULL;
 571     int ret;
 572
 573     g_assert(s && parser);
 574
 575     g_debug("process_event: called");
 576     obj = json_parser_parse_err(tokens, NULL, &err);
 577     if (err || !obj || qobject_type(obj) != QTYPE_QDICT) {
 578         qobject_decref(obj);
 579         qdict = qdict_new();
 580         if (!err) {
 581             g_warning("failed to parse event: unknown error");
 582             error_set(&err, QERR_JSON_PARSING);
 583         } else {
 584             g_warning("failed to parse event: %s", error_get_pretty(err));
 585         }
 586         qdict_put_obj(qdict, "error", qmp_build_error_object(err));
 587         error_free(err);
 588     } else {
 589         qdict = qobject_to_qdict(obj);
 590     }
 591
 592     g_assert(qdict);
 593
 594     /* handle host->guest commands */
 595     if (qdict_haskey(qdict, "execute")) {
 596         process_command(s, qdict);
 597     } else {
 598         if (!qdict_haskey(qdict, "error")) {
 599             QDECREF(qdict);
 600             qdict = qdict_new();
 601             g_warning("unrecognized payload format");
 602             error_set(&err, QERR_UNSUPPORTED);
 603             qdict_put_obj(qdict, "error", qmp_build_error_object(err));
 604             error_free(err);
 605         }
 606         ret = send_response(s, QOBJECT(qdict));
 607         if (ret) {
 608             g_warning("error sending error response: %s", strerror(ret));
 609         }
 610     }
 611
 612     QDECREF(qdict);
 613 }
 614
 615 /* false return signals GAChannel to close the current client connection */
 616 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 617 {
 618     GAState *s = data;
 619     gchar buf[QGA_READ_COUNT_DEFAULT+1];
 620     gsize count;
 621     GError *err = NULL;
 622     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 623     if (err != NULL) {
 624         g_warning("error reading channel: %s", err->message);
 625         g_error_free(err);
 626         return false;
 627     }
 628     switch (status) {
 629     case G_IO_STATUS_ERROR:
 630         g_warning("error reading channel");
 631         return false;
 632     case G_IO_STATUS_NORMAL:
 633         buf[count] = 0;
 634         g_debug("read data, count: %d, data: %s", (int)count, buf);
 635         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 636         break;
 637     case G_IO_STATUS_EOF:
 638         g_debug("received EOF");
 639         if (!s->virtio) {
 640             return false;
 641         }
 642         /* fall through */
 643     case G_IO_STATUS_AGAIN:
 644         /* virtio causes us to spin here when no process is attached to
 645          * host-side chardev. sleep a bit to mitigate this
 646          */
 647         if (s->virtio) {
 648             usleep(100*1000);
 649         }
 650         return true;
 651     default:
 652         g_warning("unknown channel read status, closing");
 653         return false;
 654     }
 655     return true;
 656 }
 657
 658 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
 659 {
 660     GAChannelMethod channel_method;
 661
 662     if (method == NULL) {
 663         method = "virtio-serial";
 664     }
 665
 666     if (path == NULL) {
 667         if (strcmp(method, "virtio-serial") == 0 ) {
 668             /* try the default path for the virtio-serial port */
 669             path = QGA_VIRTIO_PATH_DEFAULT;
 670         } else if (strcmp(method, "isa-serial") == 0){
 671             /* try the default path for the serial port - COM1 */
 672             path = QGA_SERIAL_PATH_DEFAULT;
 673         } else {
 674             g_critical("must specify a path for this channel");
 675             return false;
 676         }
 677     }
 678
 679     if (strcmp(method, "virtio-serial") == 0) {
 680         s->virtio = true; /* virtio requires special handling in some cases */
 681         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 682     } else if (strcmp(method, "isa-serial") == 0) {
 683         channel_method = GA_CHANNEL_ISA_SERIAL;
 684     } else if (strcmp(method, "unix-listen") == 0) {
 685         channel_method = GA_CHANNEL_UNIX_LISTEN;
 686     } else {
 687         g_critical("unsupported channel method/type: %s", method);
 688         return false;
 689     }
 690
 691     s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
 692     if (!s->channel) {
 693         g_critical("failed to create guest agent channel");
 694         return false;
 695     }
 696
 697     return true;
 698 }
 699
 700 #ifdef _WIN32
 701 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 702                                   LPVOID ctx)
 703 {
 704     DWORD ret = NO_ERROR;
 705     GAService *service = &ga_state->service;
 706
 707     switch (ctrl)
 708     {
 709         case SERVICE_CONTROL_STOP:
 710         case SERVICE_CONTROL_SHUTDOWN:
 711             quit_handler(SIGTERM);
 712             service->status.dwCurrentState = SERVICE_STOP_PENDING;
 713             SetServiceStatus(service->status_handle, &service->status);
 714             break;
 715
 716         default:
 717             ret = ERROR_CALL_NOT_IMPLEMENTED;
 718     }
 719     return ret;
 720 }
 721
 722 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 723 {
 724     GAService *service = &ga_state->service;
 725
 726     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 727         service_ctrl_handler, NULL);
 728
 729     if (service->status_handle == 0) {
 730         g_critical("Failed to register extended requests function!\n");
 731         return;
 732     }
 733
 734     service->status.dwServiceType = SERVICE_WIN32;
 735     service->status.dwCurrentState = SERVICE_RUNNING;
 736     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 737     service->status.dwWin32ExitCode = NO_ERROR;
 738     service->status.dwServiceSpecificExitCode = NO_ERROR;
 739     service->status.dwCheckPoint = 0;
 740     service->status.dwWaitHint = 0;
 741     SetServiceStatus(service->status_handle, &service->status);
 742
 743     g_main_loop_run(ga_state->main_loop);
 744
 745     service->status.dwCurrentState = SERVICE_STOPPED;
 746     SetServiceStatus(service->status_handle, &service->status);
 747 }
 748 #endif
 749
 750 static void set_persistent_state_defaults(GAPersistentState *pstate)
 751 {
 752     g_assert(pstate);
 753     pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
 754 }
 755
 756 static void persistent_state_from_keyfile(GAPersistentState *pstate,
 757                                           GKeyFile *keyfile)
 758 {
 759     g_assert(pstate);
 760     g_assert(keyfile);
 761     /* if any fields are missing, either because the file was tampered with
 762      * by agents of chaos, or because the field wasn't present at the time the
 763      * file was created, the best we can ever do is start over with the default
 764      * values. so load them now, and ignore any errors in accessing key-value
 765      * pairs
 766      */
 767     set_persistent_state_defaults(pstate);
 768
 769     if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
 770         pstate->fd_counter =
 771             g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
 772     }
 773 }
 774
 775 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
 776                                         GKeyFile *keyfile)
 777 {
 778     g_assert(pstate);
 779     g_assert(keyfile);
 780
 781     g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
 782 }
 783
 784 static gboolean write_persistent_state(const GAPersistentState *pstate,
 785                                        const gchar *path)
 786 {
 787     GKeyFile *keyfile = g_key_file_new();
 788     GError *gerr = NULL;
 789     gboolean ret = true;
 790     gchar *data = NULL;
 791     gsize data_len;
 792
 793     g_assert(pstate);
 794
 795     persistent_state_to_keyfile(pstate, keyfile);
 796     data = g_key_file_to_data(keyfile, &data_len, &gerr);
 797     if (gerr) {
 798         g_critical("failed to convert persistent state to string: %s",
 799                    gerr->message);
 800         ret = false;
 801         goto out;
 802     }
 803
 804     g_file_set_contents(path, data, data_len, &gerr);
 805     if (gerr) {
 806         g_critical("failed to write persistent state to %s: %s",
 807                     path, gerr->message);
 808         ret = false;
 809         goto out;
 810     }
 811
 812 out:
 813     if (gerr) {
 814         g_error_free(gerr);
 815     }
 816     if (keyfile) {
 817         g_key_file_free(keyfile);
 818     }
 819     g_free(data);
 820     return ret;
 821 }
 822
 823 static gboolean read_persistent_state(GAPersistentState *pstate,
 824                                       const gchar *path, gboolean frozen)
 825 {
 826     GKeyFile *keyfile = NULL;
 827     GError *gerr = NULL;
 828     struct stat st;
 829     gboolean ret = true;
 830
 831     g_assert(pstate);
 832
 833     if (stat(path, &st) == -1) {
 834         /* it's okay if state file doesn't exist, but any other error
 835          * indicates a permissions issue or some other misconfiguration
 836          * that we likely won't be able to recover from.
 837          */
 838         if (errno != ENOENT) {
 839             g_critical("unable to access state file at path %s: %s",
 840                        path, strerror(errno));
 841             ret = false;
 842             goto out;
 843         }
 844
 845         /* file doesn't exist. initialize state to default values and
 846          * attempt to save now. (we could wait till later when we have
 847          * modified state we need to commit, but if there's a problem,
 848          * such as a missing parent directory, we want to catch it now)
 849          *
 850          * there is a potential scenario where someone either managed to
 851          * update the agent from a version that didn't use a key store
 852          * while qemu-ga thought the filesystem was frozen, or
 853          * deleted the key store prior to issuing a fsfreeze, prior
 854          * to restarting the agent. in this case we go ahead and defer
 855          * initial creation till we actually have modified state to
 856          * write, otherwise fail to recover from freeze.
 857          */
 858         set_persistent_state_defaults(pstate);
 859         if (!frozen) {
 860             ret = write_persistent_state(pstate, path);
 861             if (!ret) {
 862                 g_critical("unable to create state file at path %s", path);
 863                 ret = false;
 864                 goto out;
 865             }
 866         }
 867         ret = true;
 868         goto out;
 869     }
 870
 871     keyfile = g_key_file_new();
 872     g_key_file_load_from_file(keyfile, path, 0, &gerr);
 873     if (gerr) {
 874         g_critical("error loading persistent state from path: %s, %s",
 875                    path, gerr->message);
 876         ret = false;
 877         goto out;
 878     }
 879
 880     persistent_state_from_keyfile(pstate, keyfile);
 881
 882 out:
 883     if (keyfile) {
 884         g_key_file_free(keyfile);
 885     }
 886     if (gerr) {
 887         g_error_free(gerr);
 888     }
 889
 890     return ret;
 891 }
 892
 893 int64_t ga_get_fd_handle(GAState *s, Error **errp)
 894 {
 895     int64_t handle;
 896
 897     g_assert(s->pstate_filepath);
 898     /* we blacklist commands and avoid operations that potentially require
 899      * writing to disk when we're in a frozen state. this includes opening
 900      * new files, so we should never get here in that situation
 901      */
 902     g_assert(!ga_is_frozen(s));
 903
 904     handle = s->pstate.fd_counter++;
 905
 906     /* This should never happen on a reasonable timeframe, as guest-file-open
 907      * would have to be issued 2^63 times */
 908     if (s->pstate.fd_counter == INT64_MAX) {
 909         abort();
 910     }
 911
 912     if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
 913         error_setg(errp, "failed to commit persistent state to disk");
 914     }
 915
 916     return handle;
 917 }
 918
 919 static void ga_print_cmd(QmpCommand *cmd, void *opaque)
 920 {
 921     printf("%s\n", qmp_command_name(cmd));
 922 }
 923
 924 int main(int argc, char **argv)
 925 {
 926     const char *sopt = "hVvdm:p:l:f:F::b:s:t:";
 927     const char *method = NULL, *path = NULL;
 928     const char *log_filepath = NULL;
 929     const char *pid_filepath;
 930 #ifdef CONFIG_FSFREEZE
 931     const char *fsfreeze_hook = NULL;
 932 #endif
 933     const char *state_dir;
 934 #ifdef _WIN32
 935     const char *service = NULL;
 936 #endif
 937     const struct option lopt[] = {
 938         { "help", 0, NULL, 'h' },
 939         { "version", 0, NULL, 'V' },
 940         { "logfile", 1, NULL, 'l' },
 941         { "pidfile", 1, NULL, 'f' },
 942 #ifdef CONFIG_FSFREEZE
 943         { "fsfreeze-hook", 2, NULL, 'F' },
 944 #endif
 945         { "verbose", 0, NULL, 'v' },
 946         { "method", 1, NULL, 'm' },
 947         { "path", 1, NULL, 'p' },
 948         { "daemonize", 0, NULL, 'd' },
 949         { "blacklist", 1, NULL, 'b' },
 950 #ifdef _WIN32
 951         { "service", 1, NULL, 's' },
 952 #endif
 953         { "statedir", 1, NULL, 't' },
 954         { NULL, 0, NULL, 0 }
 955     };
 956     int opt_ind = 0, ch, daemonize = 0, i, j, len;
 957     GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
 958     GList *blacklist = NULL;
 959     GAState *s;
 960
 961     module_call_init(MODULE_INIT_QAPI);
 962
 963     init_dfl_pathnames();
 964     pid_filepath = dfl_pathnames.pidfile;
 965     state_dir = dfl_pathnames.state_dir;
 966
 967     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 968         switch (ch) {
 969         case 'm':
 970             method = optarg;
 971             break;
 972         case 'p':
 973             path = optarg;
 974             break;
 975         case 'l':
 976             log_filepath = optarg;
 977             break;
 978         case 'f':
 979             pid_filepath = optarg;
 980             break;
 981 #ifdef CONFIG_FSFREEZE
 982         case 'F':
 983             fsfreeze_hook = optarg ? optarg : QGA_FSFREEZE_HOOK_DEFAULT;
 984             break;
 985 #endif
 986         case 't':
 987              state_dir = optarg;
 988              break;
 989         case 'v':
 990             /* enable all log levels */
 991             log_level = G_LOG_LEVEL_MASK;
 992             break;
 993         case 'V':
 994             printf("QEMU Guest Agent %s\n", QEMU_VERSION);
 995             return 0;
 996         case 'd':
 997             daemonize = 1;
 998             break;
 999         case 'b': {
1000             if (is_help_option(optarg)) {
1001                 qmp_for_each_command(ga_print_cmd, NULL);
1002                 return 0;
1003             }
1004             for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
1005                 if (optarg[i] == ',') {
1006                     optarg[i] = 0;
1007                     blacklist = g_list_append(blacklist, &optarg[j]);
1008                     j = i + 1;
1009                 }
1010             }
1011             if (j < i) {
1012                 blacklist = g_list_append(blacklist, &optarg[j]);
1013             }
1014             break;
1015         }
1016 #ifdef _WIN32
1017         case 's':
1018             service = optarg;
1019             if (strcmp(service, "install") == 0) {
1020                 const char *fixed_state_dir;
1021
1022                 /* If the user passed the "-t" option, we save that state dir
1023                  * in the service. Otherwise we let the service fetch the state
1024                  * dir from the environment when it starts.
1025                  */
1026                 fixed_state_dir = (state_dir == dfl_pathnames.state_dir) ?
1027                                   NULL :
1028                                   state_dir;
1029                 if (ga_install_vss_provider()) {
1030                     return EXIT_FAILURE;
1031                 }
1032                 if (ga_install_service(path, log_filepath, fixed_state_dir)) {
1033                     return EXIT_FAILURE;
1034                 }
1035                 return 0;
1036             } else if (strcmp(service, "uninstall") == 0) {
1037                 ga_uninstall_vss_provider();
1038                 return ga_uninstall_service();
1039             } else {
1040                 printf("Unknown service command.\n");
1041                 return EXIT_FAILURE;
1042             }
1043             break;
1044 #endif
1045         case 'h':
1046             usage(argv[0]);
1047             return 0;
1048         case '?':
1049             g_print("Unknown option, try '%s --help' for more information.\n",
1050                     argv[0]);
1051             return EXIT_FAILURE;
1052         }
1053     }
1054
1055 #ifdef _WIN32
1056     /* On win32 the state directory is application specific (be it the default
1057      * or a user override). We got past the command line parsing; let's create
1058      * the directory (with any intermediate directories). If we run into an
1059      * error later on, we won't try to clean up the directory, it is considered
1060      * persistent.
1061      */
1062     if (g_mkdir_with_parents(state_dir, S_IRWXU) == -1) {
1063         g_critical("unable to create (an ancestor of) the state directory"
1064                    " '%s': %s", state_dir, strerror(errno));
1065         return EXIT_FAILURE;
1066     }
1067 #endif
1068
1069     s = g_malloc0(sizeof(GAState));
1070     s->log_level = log_level;
1071     s->log_file = stderr;
1072 #ifdef CONFIG_FSFREEZE
1073     s->fsfreeze_hook = fsfreeze_hook;
1074 #endif
1075     g_log_set_default_handler(ga_log, s);
1076     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1077     ga_enable_logging(s);
1078     s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1079                                                  state_dir);
1080     s->pstate_filepath = g_strdup_printf("%s/qga.state", state_dir);
1081     s->frozen = false;
1082
1083 #ifndef _WIN32
1084     /* check if a previous instance of qemu-ga exited with filesystems' state
1085      * marked as frozen. this could be a stale value (a non-qemu-ga process
1086      * or reboot may have since unfrozen them), but better to require an
1087      * uneeded unfreeze than to risk hanging on start-up
1088      */
1089     struct stat st;
1090     if (stat(s->state_filepath_isfrozen, &st) == -1) {
1091         /* it's okay if the file doesn't exist, but if we can't access for
1092          * some other reason, such as permissions, there's a configuration
1093          * that needs to be addressed. so just bail now before we get into
1094          * more trouble later
1095          */
1096         if (errno != ENOENT) {
1097             g_critical("unable to access state file at path %s: %s",
1098                        s->state_filepath_isfrozen, strerror(errno));
1099             return EXIT_FAILURE;
1100         }
1101     } else {
1102         g_warning("previous instance appears to have exited with frozen"
1103                   " filesystems. deferring logging/pidfile creation and"
1104                   " disabling non-fsfreeze-safe commands until"
1105                   " guest-fsfreeze-thaw is issued, or filesystems are"
1106                   " manually unfrozen and the file %s is removed",
1107                   s->state_filepath_isfrozen);
1108         s->frozen = true;
1109     }
1110 #endif
1111
1112     if (ga_is_frozen(s)) {
1113         if (daemonize) {
1114             /* delay opening/locking of pidfile till filesystem are unfrozen */
1115             s->deferred_options.pid_filepath = pid_filepath;
1116             become_daemon(NULL);
1117         }
1118         if (log_filepath) {
1119             /* delay opening the log file till filesystems are unfrozen */
1120             s->deferred_options.log_filepath = log_filepath;
1121         }
1122         ga_disable_logging(s);
1123         qmp_for_each_command(ga_disable_non_whitelisted, NULL);
1124     } else {
1125         if (daemonize) {
1126             become_daemon(pid_filepath);
1127         }
1128         if (log_filepath) {
1129             FILE *log_file = ga_open_logfile(log_filepath);
1130             if (!log_file) {
1131                 g_critical("unable to open specified log file: %s",
1132                            strerror(errno));
1133                 goto out_bad;
1134             }
1135             s->log_file = log_file;
1136         }
1137     }
1138
1139     /* load persistent state from disk */
1140     if (!read_persistent_state(&s->pstate,
1141                                s->pstate_filepath,
1142                                ga_is_frozen(s))) {
1143         g_critical("failed to load persistent state");
1144         goto out_bad;
1145     }
1146
1147     if (blacklist) {
1148         s->blacklist = blacklist;
1149         do {
1150             g_debug("disabling command: %s", (char *)blacklist->data);
1151             qmp_disable_command(blacklist->data);
1152             blacklist = g_list_next(blacklist);
1153         } while (blacklist);
1154     }
1155     s->command_state = ga_command_state_new();
1156     ga_command_state_init(s, s->command_state);
1157     ga_command_state_init_all(s->command_state);
1158     json_message_parser_init(&s->parser, process_event);
1159     ga_state = s;
1160 #ifndef _WIN32
1161     if (!register_signal_handlers()) {
1162         g_critical("failed to register signal handlers");
1163         goto out_bad;
1164     }
1165 #endif
1166
1167     s->main_loop = g_main_loop_new(NULL, false);
1168     if (!channel_init(ga_state, method, path)) {
1169         g_critical("failed to initialize guest agent channel");
1170         goto out_bad;
1171     }
1172 #ifndef _WIN32
1173     g_main_loop_run(ga_state->main_loop);
1174 #else
1175     if (daemonize) {
1176         SERVICE_TABLE_ENTRY service_table[] = {
1177             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1178         StartServiceCtrlDispatcher(service_table);
1179     } else {
1180         g_main_loop_run(ga_state->main_loop);
1181     }
1182 #endif
1183
1184     ga_command_state_cleanup_all(ga_state->command_state);
1185     ga_channel_free(ga_state->channel);
1186
1187     if (daemonize) {
1188         unlink(pid_filepath);
1189     }
1190     return 0;
1191
1192 out_bad:
1193     if (daemonize) {
1194         unlink(pid_filepath);
1195     }
1196     return EXIT_FAILURE;
1197 }