qemu-ga.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 #ifndef _WIN32
  19 #include <syslog.h>
  20 #include <sys/wait.h>
  21 #endif
  22 #include "json-streamer.h"
  23 #include "json-parser.h"
  24 #include "qint.h"
  25 #include "qjson.h"
  26 #include "qga/guest-agent-core.h"
  27 #include "module.h"
  28 #include "signal.h"
  29 #include "qerror.h"
  30 #include "error_int.h"
  31 #include "qapi/qmp-core.h"
  32 #include "qga/channel.h"
  33 #ifdef _WIN32
  34 #include "qga/service-win32.h"
  35 #include <windows.h>
  36 #endif
  37
  38 #ifndef _WIN32
  39 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
  40 #else
  41 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
  42 #endif
  43 #define QGA_PIDFILE_DEFAULT "/var/run/qemu-ga.pid"
  44 #define QGA_SENTINEL_BYTE 0xFF
  45
  46 struct GAState {
  47     JSONMessageParser parser;
  48     GMainLoop *main_loop;
  49     GAChannel *channel;
  50     bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
  51     GACommandState *command_state;
  52     GLogLevelFlags log_level;
  53     FILE *log_file;
  54     bool logging_enabled;
  55 #ifdef _WIN32
  56     GAService service;
  57 #endif
  58     bool delimit_response;
  59 };
  60
  61 struct GAState *ga_state;
  62
  63 #ifdef _WIN32
  64 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
  65                                   LPVOID ctx);
  66 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
  67 #endif
  68
  69 static void quit_handler(int sig)
  70 {
  71     g_debug("received signal num %d, quitting", sig);
  72
  73     if (g_main_loop_is_running(ga_state->main_loop)) {
  74         g_main_loop_quit(ga_state->main_loop);
  75     }
  76 }
  77
  78 #ifndef _WIN32
  79 /* reap _all_ terminated children */
  80 static void child_handler(int sig)
  81 {
  82     int status;
  83     while (waitpid(-1, &status, WNOHANG) > 0) /* NOTHING */;
  84 }
  85
  86 static gboolean register_signal_handlers(void)
  87 {
  88     struct sigaction sigact, sigact_chld;
  89     int ret;
  90
  91     memset(&sigact, 0, sizeof(struct sigaction));
  92     sigact.sa_handler = quit_handler;
  93
  94     ret = sigaction(SIGINT, &sigact, NULL);
  95     if (ret == -1) {
  96         g_error("error configuring signal handler: %s", strerror(errno));
  97         return false;
  98     }
  99     ret = sigaction(SIGTERM, &sigact, NULL);
 100     if (ret == -1) {
 101         g_error("error configuring signal handler: %s", strerror(errno));
 102         return false;
 103     }
 104
 105     memset(&sigact_chld, 0, sizeof(struct sigaction));
 106     sigact_chld.sa_handler = child_handler;
 107     sigact_chld.sa_flags = SA_NOCLDSTOP;
 108     ret = sigaction(SIGCHLD, &sigact_chld, NULL);
 109     if (ret == -1) {
 110         g_error("error configuring signal handler: %s", strerror(errno));
 111     }
 112
 113     return true;
 114 }
 115 #endif
 116
 117 static void usage(const char *cmd)
 118 {
 119     printf(
 120 "Usage: %s [-m <method> -p <path>] [<options>]\n"
 121 "QEMU Guest Agent %s\n"
 122 "\n"
 123 "  -m, --method      transport method: one of unix-listen, virtio-serial, or\n"
 124 "                    isa-serial (virtio-serial is the default)\n"
 125 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
 126 "                    %s)\n"
 127 "  -l, --logfile     set logfile path, logs to stderr by default\n"
 128 "  -f, --pidfile     specify pidfile (default is %s)\n"
 129 "  -v, --verbose     log extra debugging information\n"
 130 "  -V, --version     print version information and exit\n"
 131 "  -d, --daemonize   become a daemon\n"
 132 #ifdef _WIN32
 133 "  -s, --service     service commands: install, uninstall\n"
 134 #endif
 135 "  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\"\n"
 136 "                    to list available RPCs)\n"
 137 "  -h, --help        display this help and exit\n"
 138 "\n"
 139 "Report bugs to <mdroth@linux.vnet.ibm.com>\n"
 140     , cmd, QGA_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT);
 141 }
 142
 143 static const char *ga_log_level_str(GLogLevelFlags level)
 144 {
 145     switch (level & G_LOG_LEVEL_MASK) {
 146         case G_LOG_LEVEL_ERROR:
 147             return "error";
 148         case G_LOG_LEVEL_CRITICAL:
 149             return "critical";
 150         case G_LOG_LEVEL_WARNING:
 151             return "warning";
 152         case G_LOG_LEVEL_MESSAGE:
 153             return "message";
 154         case G_LOG_LEVEL_INFO:
 155             return "info";
 156         case G_LOG_LEVEL_DEBUG:
 157             return "debug";
 158         default:
 159             return "user";
 160     }
 161 }
 162
 163 bool ga_logging_enabled(GAState *s)
 164 {
 165     return s->logging_enabled;
 166 }
 167
 168 void ga_disable_logging(GAState *s)
 169 {
 170     s->logging_enabled = false;
 171 }
 172
 173 void ga_enable_logging(GAState *s)
 174 {
 175     s->logging_enabled = true;
 176 }
 177
 178 static void ga_log(const gchar *domain, GLogLevelFlags level,
 179                    const gchar *msg, gpointer opaque)
 180 {
 181     GAState *s = opaque;
 182     GTimeVal time;
 183     const char *level_str = ga_log_level_str(level);
 184
 185     if (!ga_logging_enabled(s)) {
 186         return;
 187     }
 188
 189     level &= G_LOG_LEVEL_MASK;
 190 #ifndef _WIN32
 191     if (domain && strcmp(domain, "syslog") == 0) {
 192         syslog(LOG_INFO, "%s: %s", level_str, msg);
 193     } else if (level & s->log_level) {
 194 #else
 195     if (level & s->log_level) {
 196 #endif
 197         g_get_current_time(&time);
 198         fprintf(s->log_file,
 199                 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
 200         fflush(s->log_file);
 201     }
 202 }
 203
 204 void ga_set_response_delimited(GAState *s)
 205 {
 206     s->delimit_response = true;
 207 }
 208
 209 #ifndef _WIN32
 210 static void become_daemon(const char *pidfile)
 211 {
 212     pid_t pid, sid;
 213     int pidfd;
 214     char *pidstr = NULL;
 215
 216     pid = fork();
 217     if (pid < 0) {
 218         exit(EXIT_FAILURE);
 219     }
 220     if (pid > 0) {
 221         exit(EXIT_SUCCESS);
 222     }
 223
 224     pidfd = open(pidfile, O_CREAT|O_WRONLY|O_EXCL, S_IRUSR|S_IWUSR);
 225     if (pidfd == -1) {
 226         g_critical("Cannot create pid file, %s", strerror(errno));
 227         exit(EXIT_FAILURE);
 228     }
 229
 230     if (asprintf(&pidstr, "%d", getpid()) == -1) {
 231         g_critical("Cannot allocate memory");
 232         goto fail;
 233     }
 234     if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
 235         free(pidstr);
 236         g_critical("Failed to write pid file");
 237         goto fail;
 238     }
 239
 240     umask(0);
 241     sid = setsid();
 242     if (sid < 0) {
 243         goto fail;
 244     }
 245     if ((chdir("/")) < 0) {
 246         goto fail;
 247     }
 248
 249     close(STDIN_FILENO);
 250     close(STDOUT_FILENO);
 251     close(STDERR_FILENO);
 252     free(pidstr);
 253     return;
 254
 255 fail:
 256     unlink(pidfile);
 257     g_critical("failed to daemonize");
 258     exit(EXIT_FAILURE);
 259 }
 260 #endif
 261
 262 static int send_response(GAState *s, QObject *payload)
 263 {
 264     const char *buf;
 265     QString *payload_qstr, *response_qstr;
 266     GIOStatus status;
 267
 268     g_assert(payload && s->channel);
 269
 270     payload_qstr = qobject_to_json(payload);
 271     if (!payload_qstr) {
 272         return -EINVAL;
 273     }
 274
 275     if (s->delimit_response) {
 276         s->delimit_response = false;
 277         response_qstr = qstring_new();
 278         qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
 279         qstring_append(response_qstr, qstring_get_str(payload_qstr));
 280         QDECREF(payload_qstr);
 281     } else {
 282         response_qstr = payload_qstr;
 283     }
 284
 285     qstring_append_chr(response_qstr, '\n');
 286     buf = qstring_get_str(response_qstr);
 287     status = ga_channel_write_all(s->channel, buf, strlen(buf));
 288     QDECREF(response_qstr);
 289     if (status != G_IO_STATUS_NORMAL) {
 290         return -EIO;
 291     }
 292
 293     return 0;
 294 }
 295
 296 static void process_command(GAState *s, QDict *req)
 297 {
 298     QObject *rsp = NULL;
 299     int ret;
 300
 301     g_assert(req);
 302     g_debug("processing command");
 303     rsp = qmp_dispatch(QOBJECT(req));
 304     if (rsp) {
 305         ret = send_response(s, rsp);
 306         if (ret) {
 307             g_warning("error sending response: %s", strerror(ret));
 308         }
 309         qobject_decref(rsp);
 310     } else {
 311         g_warning("error getting response");
 312     }
 313 }
 314
 315 /* handle requests/control events coming in over the channel */
 316 static void process_event(JSONMessageParser *parser, QList *tokens)
 317 {
 318     GAState *s = container_of(parser, GAState, parser);
 319     QObject *obj;
 320     QDict *qdict;
 321     Error *err = NULL;
 322     int ret;
 323
 324     g_assert(s && parser);
 325
 326     g_debug("process_event: called");
 327     obj = json_parser_parse_err(tokens, NULL, &err);
 328     if (err || !obj || qobject_type(obj) != QTYPE_QDICT) {
 329         qobject_decref(obj);
 330         qdict = qdict_new();
 331         if (!err) {
 332             g_warning("failed to parse event: unknown error");
 333             error_set(&err, QERR_JSON_PARSING);
 334         } else {
 335             g_warning("failed to parse event: %s", error_get_pretty(err));
 336         }
 337         qdict_put_obj(qdict, "error", error_get_qobject(err));
 338         error_free(err);
 339     } else {
 340         qdict = qobject_to_qdict(obj);
 341     }
 342
 343     g_assert(qdict);
 344
 345     /* handle host->guest commands */
 346     if (qdict_haskey(qdict, "execute")) {
 347         process_command(s, qdict);
 348     } else {
 349         if (!qdict_haskey(qdict, "error")) {
 350             QDECREF(qdict);
 351             qdict = qdict_new();
 352             g_warning("unrecognized payload format");
 353             error_set(&err, QERR_UNSUPPORTED);
 354             qdict_put_obj(qdict, "error", error_get_qobject(err));
 355             error_free(err);
 356         }
 357         ret = send_response(s, QOBJECT(qdict));
 358         if (ret) {
 359             g_warning("error sending error response: %s", strerror(ret));
 360         }
 361     }
 362
 363     QDECREF(qdict);
 364 }
 365
 366 /* false return signals GAChannel to close the current client connection */
 367 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
 368 {
 369     GAState *s = data;
 370     gchar buf[QGA_READ_COUNT_DEFAULT+1];
 371     gsize count;
 372     GError *err = NULL;
 373     GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
 374     if (err != NULL) {
 375         g_warning("error reading channel: %s", err->message);
 376         g_error_free(err);
 377         return false;
 378     }
 379     switch (status) {
 380     case G_IO_STATUS_ERROR:
 381         g_warning("error reading channel");
 382         return false;
 383     case G_IO_STATUS_NORMAL:
 384         buf[count] = 0;
 385         g_debug("read data, count: %d, data: %s", (int)count, buf);
 386         json_message_parser_feed(&s->parser, (char *)buf, (int)count);
 387         break;
 388     case G_IO_STATUS_EOF:
 389         g_debug("received EOF");
 390         if (!s->virtio) {
 391             return false;
 392         }
 393     case G_IO_STATUS_AGAIN:
 394         /* virtio causes us to spin here when no process is attached to
 395          * host-side chardev. sleep a bit to mitigate this
 396          */
 397         if (s->virtio) {
 398             usleep(100*1000);
 399         }
 400         return true;
 401     default:
 402         g_warning("unknown channel read status, closing");
 403         return false;
 404     }
 405     return true;
 406 }
 407
 408 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
 409 {
 410     GAChannelMethod channel_method;
 411
 412     if (method == NULL) {
 413         method = "virtio-serial";
 414     }
 415
 416     if (path == NULL) {
 417         if (strcmp(method, "virtio-serial") != 0) {
 418             g_critical("must specify a path for this channel");
 419             return false;
 420         }
 421         /* try the default path for the virtio-serial port */
 422         path = QGA_VIRTIO_PATH_DEFAULT;
 423     }
 424
 425     if (strcmp(method, "virtio-serial") == 0) {
 426         s->virtio = true; /* virtio requires special handling in some cases */
 427         channel_method = GA_CHANNEL_VIRTIO_SERIAL;
 428     } else if (strcmp(method, "isa-serial") == 0) {
 429         channel_method = GA_CHANNEL_ISA_SERIAL;
 430     } else if (strcmp(method, "unix-listen") == 0) {
 431         channel_method = GA_CHANNEL_UNIX_LISTEN;
 432     } else {
 433         g_critical("unsupported channel method/type: %s", method);
 434         return false;
 435     }
 436
 437     s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
 438     if (!s->channel) {
 439         g_critical("failed to create guest agent channel");
 440         return false;
 441     }
 442
 443     return true;
 444 }
 445
 446 #ifdef _WIN32
 447 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
 448                                   LPVOID ctx)
 449 {
 450     DWORD ret = NO_ERROR;
 451     GAService *service = &ga_state->service;
 452
 453     switch (ctrl)
 454     {
 455         case SERVICE_CONTROL_STOP:
 456         case SERVICE_CONTROL_SHUTDOWN:
 457             quit_handler(SIGTERM);
 458             service->status.dwCurrentState = SERVICE_STOP_PENDING;
 459             SetServiceStatus(service->status_handle, &service->status);
 460             break;
 461
 462         default:
 463             ret = ERROR_CALL_NOT_IMPLEMENTED;
 464     }
 465     return ret;
 466 }
 467
 468 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
 469 {
 470     GAService *service = &ga_state->service;
 471
 472     service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
 473         service_ctrl_handler, NULL);
 474
 475     if (service->status_handle == 0) {
 476         g_critical("Failed to register extended requests function!\n");
 477         return;
 478     }
 479
 480     service->status.dwServiceType = SERVICE_WIN32;
 481     service->status.dwCurrentState = SERVICE_RUNNING;
 482     service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
 483     service->status.dwWin32ExitCode = NO_ERROR;
 484     service->status.dwServiceSpecificExitCode = NO_ERROR;
 485     service->status.dwCheckPoint = 0;
 486     service->status.dwWaitHint = 0;
 487     SetServiceStatus(service->status_handle, &service->status);
 488
 489     g_main_loop_run(ga_state->main_loop);
 490
 491     service->status.dwCurrentState = SERVICE_STOPPED;
 492     SetServiceStatus(service->status_handle, &service->status);
 493 }
 494 #endif
 495
 496 int main(int argc, char **argv)
 497 {
 498     const char *sopt = "hVvdm:p:l:f:b:s:";
 499     const char *method = NULL, *path = NULL, *pidfile = QGA_PIDFILE_DEFAULT;
 500     const char *log_file_name = NULL;
 501 #ifdef _WIN32
 502     const char *service = NULL;
 503 #endif
 504     const struct option lopt[] = {
 505         { "help", 0, NULL, 'h' },
 506         { "version", 0, NULL, 'V' },
 507         { "logfile", 1, NULL, 'l' },
 508         { "pidfile", 1, NULL, 'f' },
 509         { "verbose", 0, NULL, 'v' },
 510         { "method", 1, NULL, 'm' },
 511         { "path", 1, NULL, 'p' },
 512         { "daemonize", 0, NULL, 'd' },
 513         { "blacklist", 1, NULL, 'b' },
 514 #ifdef _WIN32
 515         { "service", 1, NULL, 's' },
 516 #endif
 517         { NULL, 0, NULL, 0 }
 518     };
 519     int opt_ind = 0, ch, daemonize = 0, i, j, len;
 520     GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
 521     FILE *log_file = stderr;
 522     GAState *s;
 523
 524     module_call_init(MODULE_INIT_QAPI);
 525
 526     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 527         switch (ch) {
 528         case 'm':
 529             method = optarg;
 530             break;
 531         case 'p':
 532             path = optarg;
 533             break;
 534         case 'l':
 535             log_file_name = optarg;
 536             log_file = fopen(log_file_name, "a");
 537             if (!log_file) {
 538                 g_critical("unable to open specified log file: %s",
 539                            strerror(errno));
 540                 return EXIT_FAILURE;
 541             }
 542             break;
 543         case 'f':
 544             pidfile = optarg;
 545             break;
 546         case 'v':
 547             /* enable all log levels */
 548             log_level = G_LOG_LEVEL_MASK;
 549             break;
 550         case 'V':
 551             printf("QEMU Guest Agent %s\n", QGA_VERSION);
 552             return 0;
 553         case 'd':
 554             daemonize = 1;
 555             break;
 556         case 'b': {
 557             char **list_head, **list;
 558             if (*optarg == '?') {
 559                 list_head = list = qmp_get_command_list();
 560                 while (*list != NULL) {
 561                     printf("%s\n", *list);
 562                     g_free(*list);
 563                     list++;
 564                 }
 565                 g_free(list_head);
 566                 return 0;
 567             }
 568             for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
 569                 if (optarg[i] == ',') {
 570                     optarg[i] = 0;
 571                     qmp_disable_command(&optarg[j]);
 572                     g_debug("disabling command: %s", &optarg[j]);
 573                     j = i + 1;
 574                 }
 575             }
 576             if (j < i) {
 577                 qmp_disable_command(&optarg[j]);
 578                 g_debug("disabling command: %s", &optarg[j]);
 579             }
 580             break;
 581         }
 582 #ifdef _WIN32
 583         case 's':
 584             service = optarg;
 585             if (strcmp(service, "install") == 0) {
 586                 return ga_install_service(path, log_file_name);
 587             } else if (strcmp(service, "uninstall") == 0) {
 588                 return ga_uninstall_service();
 589             } else {
 590                 printf("Unknown service command.\n");
 591                 return EXIT_FAILURE;
 592             }
 593             break;
 594 #endif
 595         case 'h':
 596             usage(argv[0]);
 597             return 0;
 598         case '?':
 599             g_print("Unknown option, try '%s --help' for more information.\n",
 600                     argv[0]);
 601             return EXIT_FAILURE;
 602         }
 603     }
 604
 605 #ifndef _WIN32
 606     if (daemonize) {
 607         g_debug("starting daemon");
 608         become_daemon(pidfile);
 609     }
 610 #endif
 611
 612     s = g_malloc0(sizeof(GAState));
 613     s->log_file = log_file;
 614     s->log_level = log_level;
 615     g_log_set_default_handler(ga_log, s);
 616     g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
 617     s->logging_enabled = true;
 618     s->command_state = ga_command_state_new();
 619     ga_command_state_init(s, s->command_state);
 620     ga_command_state_init_all(s->command_state);
 621     json_message_parser_init(&s->parser, process_event);
 622     ga_state = s;
 623 #ifndef _WIN32
 624     if (!register_signal_handlers()) {
 625         g_critical("failed to register signal handlers");
 626         goto out_bad;
 627     }
 628 #endif
 629
 630     s->main_loop = g_main_loop_new(NULL, false);
 631     if (!channel_init(ga_state, method, path)) {
 632         g_critical("failed to initialize guest agent channel");
 633         goto out_bad;
 634     }
 635 #ifndef _WIN32
 636     g_main_loop_run(ga_state->main_loop);
 637 #else
 638     if (daemonize) {
 639         SERVICE_TABLE_ENTRY service_table[] = {
 640             { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
 641         StartServiceCtrlDispatcher(service_table);
 642     } else {
 643         g_main_loop_run(ga_state->main_loop);
 644     }
 645 #endif
 646
 647     ga_command_state_cleanup_all(ga_state->command_state);
 648     ga_channel_free(ga_state->channel);
 649
 650     if (daemonize) {
 651         unlink(pidfile);
 652     }
 653     return 0;
 654
 655 out_bad:
 656     if (daemonize) {
 657         unlink(pidfile);
 658     }
 659     return EXIT_FAILURE;
 660 }