server.c

   1 /* Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2
   3 /** \file server.c Paraslash's main server. */
   4
   5 /**
   6  * \mainpage Main data structures and selected APIs:
   7  *
   8  *      - Senders: \ref sender,
   9  *      - Audio file selector: \ref afs_info, \ref afs_table,
  10  *      - Audio format handler: \ref audio_format_handler, \ref afh_info
  11  *      - Receivers/filters/writers: \ref receiver, \ref receiver_node,
  12  *        \ref filter, \ref filter_node, \ref writer_node, \ref writer.
  13  *      - Scheduling: \ref sched.h,
  14  *      - Buffer trees: \ref buffer_tree.h,
  15  *      - Sideband API: \ref sideband.h,
  16  *      - Crypto: \ref crypt.h, \ref crypt_backend.h,
  17  *      - Error subsystem: \ref error.h,
  18  *      - Inter process communication: \ref ipc.h,
  19  *      - Forward error correction: \ref fec.h,
  20  *      - Daemons: \ref daemon.h,
  21  *      - Mixer API: \ref mix.h,
  22  *      - Interactive sessions: \ref interactive.h,
  23  *      - File descriptors: \ref fd.h,
  24  *      - Signals: \ref signal.h,
  25  *      - Networking: \ref net.h,
  26  *      - Time: \ref time.c,
  27  *      - Doubly linked lists: \ref list.h.
  28  */
  29
  30 #include <netinet/in.h>
  31 #include <sys/socket.h>
  32 #include <signal.h>
  33 #include <regex.h>
  34 #include <osl.h>
  35 #include <sys/types.h>
  36 #include <arpa/inet.h>
  37 #include <sys/un.h>
  38 #include <netdb.h>
  39 #include <lopsub.h>
  40
  41 #include "server.lsg.h"
  42 #include "para.h"
  43 #include "error.h"
  44 #include "crypt.h"
  45 #include "afh.h"
  46 #include "string.h"
  47 #include "afs.h"
  48 #include "server.h"
  49 #include "list.h"
  50 #include "send.h"
  51 #include "sched.h"
  52 #include "vss.h"
  53 #include "config.h"
  54 #include "close_on_fork.h"
  55 #include "net.h"
  56 #include "daemon.h"
  57 #include "ipc.h"
  58 #include "fd.h"
  59 #include "signal.h"
  60 #include "user_list.h"
  61 #include "color.h"
  62 #include "version.h"
  63
  64 /** Array of error strings. */
  65 DEFINE_PARA_ERRLIST;
  66
  67 __printf_2_3 void (*para_log)(int, const char*, ...) = daemon_log;
  68
  69 /** Shut down non-authorized connections after that many seconds. */
  70 #define ALARM_TIMEOUT 10
  71
  72 /**
  73  * Pointer to shared memory area for communication between para_server
  74  * and its children. Exported to vss.c, command.c and to afs.
  75  */
  76 struct misc_meta_data *mmd;
  77
  78 /**
  79  * The active value for all config options of para_server.
  80  *
  81  * It is computed by merging the parse result of the command line options with
  82  * the parse result of the config file.
  83  */
  84 struct lls_parse_result *server_lpr = NULL;
  85
  86 /* Command line options (no config file options). Used in handle_sighup(). */
  87 static struct lls_parse_result *cmdline_lpr;
  88
  89 /**
  90  * A random number used to "authenticate" the afs connection.
  91  *
  92  * para_server picks this number by random before it forks the afs process. The
  93  * command handlers know this number as well and write it to the afs socket,
  94  * together with the id of the shared memory area which contains the payload of
  95  * the afs command. A local process has to know this number to abuse the afs
  96  * service provided by the local socket.
  97  */
  98 uint32_t afs_socket_cookie;
  99
 100 /** The mutex protecting the shared memory area containing the mmd struct. */
 101 int mmd_mutex;
 102
 103 /* Serializes log output. */
 104 static int log_mutex;
 105
 106 static struct sched sched;
 107 static struct signal_task *signal_task;
 108
 109 /** The process id of the audio file selector process. */
 110 pid_t afs_pid = 0;
 111
 112 /* The the main server process (parent of afs and the command handlers). */
 113 static pid_t server_pid;
 114
 115 /**
 116  * Tell whether the executing process is a command handler.
 117  *
 118  * Cleanup on exit must be performed differently for command handlers.
 119  *
 120  * \return True if the pid of the executing process is neither the server pid
 121  * nor the afs pid.
 122  */
 123 bool process_is_command_handler(void)
 124 {
 125         pid_t pid = getpid();
 126
 127         return pid != afs_pid && pid != server_pid;
 128 }
 129
 130 /** The task responsible for server command handling. */
 131 struct server_command_task {
 132         /** TCP port on which para_server listens for connections. */
 133         int listen_fd;
 134         /* File descriptor for the accepted socket. */
 135         int child_fd;
 136         /** Copied from para_server's main function. */
 137         int argc;
 138         /** Argument vector passed to para_server's main function. */
 139         char **argv;
 140         /** The command task structure for scheduling. */
 141         struct task *task;
 142 };
 143
 144 /**
 145  * Return the list of tasks for the server process.
 146  *
 147  * This is called from \a com_tasks(). The helper is necessary since command
 148  * handlers can not access the scheduler structure directly.
 149  *
 150  * \return A dynamically allocated string that must be freed by the caller.
 151  */
 152 char *server_get_tasks(void)
 153 {
 154         return get_task_list(&sched);
 155 }
 156
 157 static void pre_log_hook(void)
 158 {
 159         mutex_lock(log_mutex);
 160 }
 161
 162 static void post_log_hook(void)
 163 {
 164         mutex_unlock(log_mutex);
 165 }
 166
 167 /* Setup shared memory area and init mutexes */
 168 static void init_ipc_or_die(void)
 169 {
 170         void *shm;
 171         int shmid, ret = shm_new(sizeof(struct misc_meta_data));
 172
 173         if (ret < 0)
 174                 goto err_out;
 175         shmid = ret;
 176         ret = shm_attach(shmid, ATTACH_RW, &shm);
 177         shm_destroy(shmid);
 178         if (ret < 0)
 179                 goto err_out;
 180         mmd = shm;
 181
 182         ret = mutex_new();
 183         if (ret < 0)
 184                 goto err_out;
 185         mmd_mutex = ret;
 186         ret = mutex_new();
 187         if (ret < 0)
 188                 goto destroy_mmd_mutex;
 189         log_mutex = ret;
 190
 191         mmd->num_played = 0;
 192         mmd->num_commands = 0;
 193         mmd->events = 0;
 194         mmd->num_connects = 0;
 195         mmd->active_connections = 0;
 196         mmd->vss_status_flags = VSS_NEXT;
 197         mmd->new_vss_status_flags = VSS_NEXT;
 198         return;
 199 destroy_mmd_mutex:
 200         mutex_destroy(mmd_mutex);
 201 err_out:
 202         PARA_EMERG_LOG("%s\n", para_strerror(-ret));
 203         exit(EXIT_FAILURE);
 204 }
 205
 206 /**
 207  * (Re-)read the server configuration files.
 208  *
 209  * \param reload Whether config file overrides command line.
 210  *
 211  * This function also re-opens the logfile and the user list. On SIGHUP it is
 212  * called from both server and afs context.
 213  */
 214 void parse_config_or_die(bool reload)
 215 {
 216         int ret;
 217         char *cf = NULL, *errctx = NULL, *user_list_file = NULL;
 218         void *map;
 219         size_t sz;
 220         int cf_argc;
 221         char **cf_argv;
 222         struct lls_parse_result *cf_lpr, *merged_lpr;
 223         char *home = para_homedir();
 224
 225         if (OPT_GIVEN(CONFIG_FILE))
 226                 cf = para_strdup(OPT_STRING_VAL(CONFIG_FILE));
 227         else
 228                 cf = make_message("%s/.paraslash/server.conf", home);
 229         if (!mmd || getpid() != afs_pid) {
 230                 if (OPT_GIVEN(USER_LIST))
 231                         user_list_file = para_strdup(OPT_STRING_VAL(USER_LIST));
 232                 else
 233                         user_list_file = make_message("%s/.paraslash/server.users", home);
 234         }
 235         free(home);
 236         ret = mmap_full_file(cf, O_RDONLY, &map, &sz, NULL);
 237         if (ret < 0) {
 238                 if (ret != -E_EMPTY && ret != -ERRNO_TO_PARA_ERROR(ENOENT))
 239                         goto free_cf;
 240                 if (ret == -ERRNO_TO_PARA_ERROR(ENOENT) && OPT_GIVEN(CONFIG_FILE))
 241                         goto free_cf;
 242                 server_lpr = cmdline_lpr;
 243                 goto success;
 244         }
 245         ret = lls(lls_convert_config(map, sz, NULL, &cf_argv, &errctx));
 246         para_munmap(map, sz);
 247         if (ret < 0)
 248                 goto free_cf;
 249         cf_argc = ret;
 250         ret = lls(lls_parse(cf_argc, cf_argv, CMD_PTR, &cf_lpr, &errctx));
 251         lls_free_argv(cf_argv);
 252         if (ret < 0)
 253                 goto free_cf;
 254         if (reload) /* config file overrides command line */
 255                 ret = lls(lls_merge(cf_lpr, cmdline_lpr, CMD_PTR, &merged_lpr,
 256                         &errctx));
 257         else /* command line options override config file options */
 258                 ret = lls(lls_merge(cmdline_lpr, cf_lpr, CMD_PTR, &merged_lpr,
 259                         &errctx));
 260         lls_free_parse_result(cf_lpr, CMD_PTR);
 261         if (ret < 0)
 262                 goto free_cf;
 263         if (server_lpr != cmdline_lpr)
 264                 lls_free_parse_result(server_lpr, CMD_PTR);
 265         server_lpr = merged_lpr;
 266 success:
 267         daemon_set_loglevel(ENUM_STRING_VAL(LOGLEVEL));
 268         if (OPT_GIVEN(LOGFILE)) {
 269                 daemon_set_logfile(OPT_STRING_VAL(LOGFILE));
 270                 daemon_open_log_or_die();
 271         }
 272         if (daemon_init_colors_or_die(OPT_UINT32_VAL(COLOR), COLOR_AUTO,
 273                         COLOR_NO, OPT_GIVEN(LOGFILE))) {
 274                 int i;
 275                 for (i = 0; i < OPT_GIVEN(LOG_COLOR); i++)
 276                         daemon_set_log_color_or_die(lls_string_val(i,
 277                                 OPT_RESULT(LOG_COLOR)));
 278         }
 279         daemon_set_flag(DF_LOG_PID);
 280         daemon_set_flag(DF_LOG_LL);
 281         daemon_set_flag(DF_LOG_TIME);
 282         if (OPT_GIVEN(LOG_TIMING))
 283                 daemon_set_flag(DF_LOG_TIMING);
 284         daemon_set_priority(OPT_UINT32_VAL(PRIORITY));
 285         if (user_list_file)
 286                 init_user_list(user_list_file);
 287         ret = 1;
 288 free_cf:
 289         free(cf);
 290         free(user_list_file);
 291         if (ret < 0) {
 292                 if (errctx)
 293                         PARA_ERROR_LOG("%s\n", errctx);
 294                 free(errctx);
 295                 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
 296                 exit(EXIT_FAILURE);
 297         }
 298 }
 299
 300 /*
 301  * called when server gets SIGHUP or when client invokes hup command.
 302  */
 303 static void handle_sighup(void)
 304 {
 305
 306         PARA_NOTICE_LOG("SIGHUP\n");
 307         parse_config_or_die(true);
 308         if (afs_pid != 0)
 309                 kill(afs_pid, SIGHUP);
 310 }
 311
 312 static int signal_post_select(struct sched *s, __a_unused void *context)
 313 {
 314         int ret, signum;
 315
 316         ret = task_get_notification(signal_task->task);
 317         if (ret < 0)
 318                 return ret;
 319         signum = para_next_signal(&s->rfds);
 320         switch (signum) {
 321         case 0:
 322                 return 0;
 323         case SIGHUP:
 324                 handle_sighup();
 325                 break;
 326         case SIGCHLD:
 327                 for (;;) {
 328                         pid_t pid;
 329                         ret = para_reap_child(&pid);
 330                         if (ret <= 0)
 331                                 break;
 332                         if (pid != afs_pid)
 333                                 continue;
 334                         PARA_EMERG_LOG("fatal: afs died\n");
 335                         kill(0, SIGTERM);
 336                         goto cleanup;
 337                 }
 338                 break;
 339         /* die on sigint/sigterm. Kill all children too. */
 340         case SIGINT:
 341         case SIGTERM:
 342                 PARA_EMERG_LOG("terminating on signal %d\n", signum);
 343                 kill(0, SIGTERM);
 344                 /*
 345                  * We must wait for all of our children to die. For the afs
 346                  * process or a command handler might want to use the
 347                  * shared memory area and the mmd mutex.  If we destroy this
 348                  * mutex too early and afs tries to lock the shared memory
 349                  * area, the call to mutex_lock() will fail and terminate the
 350                  * afs process. This leads to dirty osl tables.
 351                  */
 352                 PARA_INFO_LOG("waiting for child processes to die\n");
 353                 mutex_unlock(mmd_mutex);
 354                 while (wait(NULL) != -1 || errno != ECHILD)
 355                         ; /* still at least one child alive */
 356                 mutex_lock(mmd_mutex);
 357 cleanup:
 358                 free(mmd->afd.afhi.chunk_table);
 359                 task_notify_all(s, E_DEADLY_SIGNAL);
 360                 return -E_DEADLY_SIGNAL;
 361         }
 362         return 0;
 363 }
 364
 365 static void init_signal_task(void)
 366 {
 367         signal_task = signal_init_or_die();
 368         para_install_sighandler(SIGINT);
 369         para_install_sighandler(SIGTERM);
 370         para_install_sighandler(SIGHUP);
 371         para_install_sighandler(SIGCHLD);
 372         para_sigaction(SIGPIPE, SIG_IGN);
 373         add_close_on_fork_list(signal_task->fd);
 374         signal_task->task = task_register(&(struct task_info) {
 375                 .name = "signal",
 376                 .pre_select = signal_pre_select,
 377                 .post_select = signal_post_select,
 378                 .context = signal_task,
 379
 380         }, &sched);
 381 }
 382
 383 static void command_pre_select(struct sched *s, void *context)
 384 {
 385         struct server_command_task *sct = context;
 386         para_fd_set(sct->listen_fd, &s->rfds, &s->max_fileno);
 387 }
 388
 389 static int command_post_select(struct sched *s, void *context)
 390 {
 391         struct server_command_task *sct = context;
 392         int new_fd, ret, i;
 393         char *peer_name;
 394         pid_t child_pid;
 395         uint32_t *chunk_table;
 396
 397         ret = task_get_notification(sct->task);
 398         if (ret < 0)
 399                 return ret;
 400         ret = para_accept(sct->listen_fd, &s->rfds, NULL, 0, &new_fd);
 401         if (ret <= 0)
 402                 goto out;
 403         mmd->num_connects++;
 404         mmd->active_connections++;
 405         /*
 406          * The chunk table is a pointer located in the mmd struct that points
 407          * to dynamically allocated memory, i.e. it must be freed by the parent
 408          * and the child. However, as the mmd struct is in a shared memory
 409          * area, there's no guarantee that after the fork this pointer is still
 410          * valid in child context. As it is not used in the child anyway, we
 411          * save it to a local variable before the fork and free the memory via
 412          * that copy in the child directly after the fork.
 413          */
 414         chunk_table = mmd->afd.afhi.chunk_table;
 415         child_pid = fork();
 416         if (child_pid < 0) {
 417                 ret = -ERRNO_TO_PARA_ERROR(errno);
 418                 goto out;
 419         }
 420         if (child_pid) {
 421                 /* avoid problems with non-fork-safe PRNGs */
 422                 unsigned char buf[16];
 423                 get_random_bytes_or_die(buf, sizeof(buf));
 424                 close(new_fd);
 425                 /* parent keeps accepting connections */
 426                 return 0;
 427         }
 428         peer_name = remote_name(new_fd);
 429         PARA_INFO_LOG("accepted connection from %s\n", peer_name);
 430         /* mmd might already have changed at this point */
 431         free(chunk_table);
 432         sct->child_fd = new_fd;
 433         /*
 434          * put info on who we are serving into argv[0] to make
 435          * client ip visible in top/ps
 436          */
 437         for (i = sct->argc - 1; i >= 0; i--)
 438                 memset(sct->argv[i], 0, strlen(sct->argv[i]));
 439         i = sct->argc - 1 - lls_num_inputs(cmdline_lpr);
 440         sprintf(sct->argv[i], "para_server (serving %s)", peer_name);
 441         /* ask other tasks to terminate */
 442         task_notify_all(s, E_CHILD_CONTEXT);
 443         /*
 444          * After we return, the scheduler calls server_select() with a minimal
 445          * timeout value, because the remaining tasks have a notification
 446          * pending. Next it calls the ->post_select method of these tasks,
 447          * which will return negative in view of the notification. This causes
 448          * schedule() to return as there are no more runnable tasks.
 449          *
 450          * Note that semaphores are not inherited across a fork(), so we don't
 451          * hold the lock at this point. Since server_select() drops the lock
 452          * prior to calling para_select(), we need to acquire it here.
 453          */
 454         mutex_lock(mmd_mutex);
 455         return -E_CHILD_CONTEXT;
 456 out:
 457         if (ret < 0)
 458                 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
 459         return 0;
 460 }
 461
 462 static void init_server_command_task(struct server_command_task *sct,
 463                 int argc, char **argv)
 464 {
 465         int ret;
 466
 467         PARA_NOTICE_LOG("initializing tcp command socket\n");
 468         sct->child_fd = -1;
 469         sct->argc = argc;
 470         sct->argv = argv;
 471         ret = para_listen_simple(IPPROTO_TCP, OPT_UINT32_VAL(PORT));
 472         if (ret < 0)
 473                 goto err;
 474         sct->listen_fd = ret;
 475         ret = mark_fd_nonblocking(sct->listen_fd);
 476         if (ret < 0)
 477                 goto err;
 478         add_close_on_fork_list(sct->listen_fd); /* child doesn't need the listener */
 479         sct->task = task_register(&(struct task_info) {
 480                 .name = "server command",
 481                 .pre_select = command_pre_select,
 482                 .post_select = command_post_select,
 483                 .context = sct,
 484         }, &sched);
 485         return;
 486 err:
 487         PARA_EMERG_LOG("%s\n", para_strerror(-ret));
 488         exit(EXIT_FAILURE);
 489 }
 490
 491 static int init_afs(int argc, char **argv)
 492 {
 493         int ret, afs_server_socket[2];
 494         char c;
 495
 496         ret = socketpair(PF_UNIX, SOCK_STREAM, 0, afs_server_socket);
 497         if (ret < 0)
 498                 exit(EXIT_FAILURE);
 499         get_random_bytes_or_die((unsigned char *)&afs_socket_cookie,
 500                 sizeof(afs_socket_cookie));
 501         afs_pid = fork();
 502         if (afs_pid < 0)
 503                 exit(EXIT_FAILURE);
 504         if (afs_pid == 0) { /* child (afs) */
 505                 int i;
 506
 507                 afs_pid = getpid();
 508                 for (i = argc - 1; i >= 0; i--)
 509                         memset(argv[i], 0, strlen(argv[i]));
 510                 i = argc - lls_num_inputs(cmdline_lpr) - 1;
 511                 sprintf(argv[i], "para_server (afs)");
 512                 close(afs_server_socket[0]);
 513                 afs_init(afs_server_socket[1]);
 514         }
 515         close(afs_server_socket[1]);
 516         if (read(afs_server_socket[0], &c, 1) <= 0) {
 517                 PARA_EMERG_LOG("early afs exit\n");
 518                 exit(EXIT_FAILURE);
 519         }
 520         ret = mark_fd_nonblocking(afs_server_socket[0]);
 521         if (ret < 0)
 522                 exit(EXIT_FAILURE);
 523         add_close_on_fork_list(afs_server_socket[0]);
 524         PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n",
 525                 afs_server_socket[0], (unsigned) afs_socket_cookie);
 526         return afs_server_socket[0];
 527 }
 528
 529 static void handle_help_flags(void)
 530 {
 531         char *help;
 532         bool d = OPT_GIVEN(DETAILED_HELP);
 533
 534         if (d)
 535                 help = lls_long_help(CMD_PTR);
 536         else if (OPT_GIVEN(HELP))
 537                 help = lls_short_help(CMD_PTR);
 538         else
 539                 return;
 540         printf("%s\n", help);
 541         free(help);
 542         exit(EXIT_SUCCESS);
 543 }
 544
 545 static void server_init(int argc, char **argv, struct server_command_task *sct)
 546 {
 547         int ret, afs_socket, daemon_pipe = -1;
 548         char *errctx;
 549
 550         valid_fd_012();
 551         /* parse command line options */
 552         ret = lls(lls_parse(argc, argv, CMD_PTR, &cmdline_lpr, &errctx));
 553         if (ret < 0)
 554                 goto fail;
 555         server_lpr = cmdline_lpr;
 556         daemon_set_loglevel(ENUM_STRING_VAL(LOGLEVEL));
 557         daemon_drop_privileges_or_die(OPT_STRING_VAL(USER),
 558                 OPT_STRING_VAL(GROUP));
 559         version_handle_flag("server", OPT_GIVEN(VERSION));
 560         handle_help_flags();
 561         parse_config_or_die(false);
 562         /* become daemon */
 563         if (OPT_GIVEN(DAEMON))
 564                 daemon_pipe = daemonize(true /* parent waits for SIGTERM */);
 565         server_pid = getpid();
 566         init_random_seed_or_die();
 567         daemon_log_welcome("server");
 568         init_ipc_or_die(); /* init mmd struct, mmd and log mutex */
 569         daemon_set_start_time();
 570         daemon_set_hooks(pre_log_hook, post_log_hook);
 571         PARA_NOTICE_LOG("initializing audio format handlers\n");
 572         afh_init();
 573
 574         /*
 575          * Although afs uses its own signal handling we must ignore SIGUSR1
 576          * _before_ the afs child process gets born by init_afs() below.  It's
 577          * racy to do this in the child because the parent might send SIGUSR1
 578          * before the child gets a chance to ignore this signal.
 579          *
 580          * We also have to block SIGCHLD before the afs process is created
 581          * because otherwise para_server does not notice if afs dies before the
 582          * SIGCHLD handler has been installed for the parent process by
 583          * init_signal_task() below.
 584          */
 585         para_sigaction(SIGUSR1, SIG_IGN);
 586         para_block_signal(SIGCHLD);
 587         PARA_NOTICE_LOG("initializing the audio file selector\n");
 588         afs_socket = init_afs(argc, argv);
 589         init_signal_task();
 590         para_unblock_signal(SIGCHLD);
 591         PARA_NOTICE_LOG("initializing virtual streaming system\n");
 592         vss_init(afs_socket, &sched);
 593         init_server_command_task(sct, argc, argv);
 594         if (daemon_pipe >= 0) {
 595                 if (write(daemon_pipe, "\0", 1) < 0) {
 596                         PARA_EMERG_LOG("daemon_pipe: %s", strerror(errno));
 597                         exit(EXIT_FAILURE);
 598                 }
 599                 close(daemon_pipe);
 600         }
 601         PARA_NOTICE_LOG("server init complete\n");
 602         return;
 603 fail:
 604         assert(ret < 0);
 605         if (errctx)
 606                 PARA_ERROR_LOG("%s\n", errctx);
 607         PARA_EMERG_LOG("%s\n", para_strerror(-ret));
 608         exit(EXIT_FAILURE);
 609 }
 610
 611 static void status_refresh(void)
 612 {
 613         static int prev_uptime = -1, prev_events = -1;
 614         int uptime = daemon_get_uptime(now);
 615
 616         if (prev_events != mmd->events)
 617                 goto out;
 618         if (mmd->new_vss_status_flags != mmd->vss_status_flags)
 619                 goto out_inc_events;
 620         if (uptime / 60 != prev_uptime / 60)
 621                 goto out_inc_events;
 622         return;
 623 out_inc_events:
 624         mmd->events++;
 625 out:
 626         prev_uptime = uptime;
 627         prev_events = mmd->events;
 628         mmd->vss_status_flags = mmd->new_vss_status_flags;
 629         PARA_DEBUG_LOG("%u events, forcing status update\n", mmd->events);
 630         killpg(0, SIGUSR1);
 631 }
 632
 633 static int server_select(int max_fileno, fd_set *readfds, fd_set *writefds,
 634                 struct timeval *timeout_tv)
 635 {
 636         int ret;
 637
 638         status_refresh();
 639         mutex_unlock(mmd_mutex);
 640         ret = para_select(max_fileno + 1, readfds, writefds, timeout_tv);
 641         mutex_lock(mmd_mutex);
 642         return ret;
 643 }
 644
 645 /**
 646  * The main function of para_server.
 647  *
 648  * \param argc Usual argument count.
 649  * \param argv Usual argument vector.
 650  *
 651  * \return EXIT_SUCCESS or EXIT_FAILURE.
 652  */
 653 int main(int argc, char *argv[])
 654 {
 655         int ret;
 656         struct server_command_task server_command_task_struct,
 657                 *sct = &server_command_task_struct;
 658
 659         sched.default_timeout.tv_sec = 1;
 660         sched.select_function = server_select;
 661
 662         server_init(argc, argv, sct);
 663         mutex_lock(mmd_mutex);
 664         ret = schedule(&sched);
 665         /*
 666          * We hold the mmd lock: it was re-acquired in server_select()
 667          * after the select call.
 668          */
 669         mutex_unlock(mmd_mutex);
 670         sched_shutdown(&sched);
 671         signal_shutdown(signal_task);
 672         if (!process_is_command_handler()) { /* parent (server) */
 673                 mutex_destroy(mmd_mutex);
 674                 daemon_set_hooks(NULL, NULL); /* only one process remaining */
 675                 mutex_destroy(log_mutex);
 676                 shm_detach(mmd);
 677                 if (ret < 0)
 678                         PARA_EMERG_LOG("%s\n", para_strerror(-ret));
 679         } else {
 680                 alarm(ALARM_TIMEOUT);
 681                 close_listed_fds();
 682                 ret = handle_connect(sct->child_fd);
 683         }
 684         vss_shutdown();
 685         shm_detach(mmd);
 686         lls_free_parse_result(server_lpr, CMD_PTR);
 687         if (server_lpr != cmdline_lpr)
 688                 lls_free_parse_result(cmdline_lpr, CMD_PTR);
 689         exit(ret < 0? EXIT_FAILURE : EXIT_SUCCESS);
 690 }