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