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