server.c

   1 /*
   2  * Copyright (C) 1997-2007 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file server.c Paraslash's main server */
   8
   9
  10 /** \mainpage Paraslash API Reference
  11  *
  12  *  Good starting points for reading are probably \ref audio_file_selector,
  13  *  \ref sender, \ref receiver, \ref receiver_node, \ref filter, \ref
  14  *  filter_node.
  15  *
  16  */
  17
  18
  19 #include "para.h"
  20 #include "server.cmdline.h"
  21 #include "afs_common.h"
  22 #include "afh.h"
  23 #include "server.h"
  24 #include "vss.h"
  25 #include "config.h"
  26 #include "close_on_fork.h"
  27 #include "send.h"
  28 #include "error.h"
  29 #include "net.h"
  30 #include "daemon.h"
  31 #include "string.h"
  32 #include "ipc.h"
  33 #include "fd.h"
  34 #include "signal.h"
  35 #include "user_list.h"
  36 #include "afs.h"
  37
  38 /** define the array of error lists needed by para_server */
  39 INIT_SERVER_ERRLISTS;
  40
  41 /** shut down non-authorized connections after that many seconds */
  42 #define ALARM_TIMEOUT 10
  43
  44 /**
  45  * pointer to shared memory area for communication between para_server
  46  * and its children. exported to vss.c. command.c and to all selectors.
  47  */
  48 struct misc_meta_data *mmd;
  49
  50 /**
  51  * the configuration of para_server
  52  *
  53  * It also contains the options for all audio file selectors, audio format handler
  54  * and all supported senders.
  55  */
  56 struct server_args_info conf;
  57
  58 /** the file containing user information (public key, permissions) */
  59 char *user_list_file = NULL;
  60
  61 extern void dccp_send_init(struct sender *);
  62 extern void http_send_init(struct sender *);
  63 extern void ortp_send_init(struct sender *);
  64
  65 /* TODO: This is better handled by autoconf */
  66 /** the list of supported audio file selectors */
  67 struct audio_file_selector selectors[] = {
  68         {
  69                 .name = "random",
  70                 .init = random_selector_init,
  71                 .update_audio_file = NULL,
  72         },
  73         {
  74                 .name = "playlist",
  75                 .init = playlist_selector_init,
  76                 .update_audio_file = NULL,
  77                 .pre_select = NULL,
  78                 .post_select = NULL,
  79         },
  80 #ifdef HAVE_MYSQL
  81         {
  82                 .name = "mysql",
  83                 .init = mysql_selector_init,
  84                 .update_audio_file = NULL,
  85                 .pre_select = NULL,
  86                 .post_select = NULL,
  87         },
  88 #endif
  89         {
  90                 .name = NULL,
  91         }
  92 };
  93
  94 /** the list of supported senders */
  95 struct sender senders[] = {
  96         {
  97                 .name = "http",
  98                 .init = http_send_init,
  99         },
 100         {
 101                 .name = "dccp",
 102                 .init = dccp_send_init,
 103         },
 104 #ifdef HAVE_ORTP
 105         {
 106                 .name = "ortp",
 107                 .init = ortp_send_init,
 108         },
 109 #endif
 110         {
 111                 .name = NULL,
 112         }
 113 };
 114
 115
 116 /* global variables for server-internal use */
 117 static FILE *logfile;
 118 static int mmd_mutex, mmd_shm_id;
 119 static int signal_pipe;
 120
 121 /**
 122  * para_server's log function
 123  *
 124  * \param ll the log level
 125  * \param fmt the format string describing the log message
 126  */
 127 void para_log(int ll, const char* fmt,...)
 128 {
 129         va_list argp;
 130         FILE *outfd;
 131         struct tm *tm;
 132         time_t t1;
 133         char str[MAXLINE] = "";
 134         pid_t mypid;
 135
 136         if (ll < conf.loglevel_arg)
 137                 return;
 138         outfd = logfile? logfile : stderr;
 139         time(&t1);
 140         tm = localtime(&t1);
 141         strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
 142         fprintf(outfd, "%s ", str);
 143         if (conf.loglevel_arg <= INFO)
 144                 fprintf(outfd, "%i: ", ll);
 145         mypid = getpid();
 146         if (conf.loglevel_arg <= INFO)
 147                 fprintf(outfd, "(%d) ", mypid);
 148         va_start(argp, fmt);
 149         vfprintf(outfd, fmt, argp);
 150         va_end(argp);
 151 }
 152
 153 /*
 154  * setup shared memory area and get mutex for locking
 155  */
 156 static void shm_init(void)
 157 {
 158         void *shm;
 159         int ret = shm_new(sizeof(struct misc_meta_data));
 160
 161         if (ret < 0)
 162                 goto err_out;
 163
 164         ret = shm_attach(ret, ATTACH_RW, &shm);
 165         if (ret < 0)
 166                 goto err_out;
 167         mmd = shm;
 168         mmd_shm_id = ret;
 169
 170         ret = mutex_new();
 171         if (ret < 0)
 172                 goto err_out;
 173         mmd_mutex = ret;
 174
 175         mmd->selector_num = 0;
 176         mmd->num_played = 0;
 177         mmd->num_commands = 0;
 178         mmd->events = 0;
 179         mmd->num_connects = 0;
 180         mmd->active_connections = 0;
 181         strcpy(mmd->filename, "(none)");
 182         mmd->audio_format = -1;
 183         mmd->vss_status_flags = VSS_NEXT;
 184         mmd->new_vss_status_flags = VSS_NEXT;
 185         mmd->sender_cmd_data.cmd_num = -1;
 186         return;
 187 err_out:
 188         PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
 189         exit(EXIT_FAILURE);
 190 }
 191
 192 /**
 193  * lock the shared memory area containing the mmd struct
 194  *
 195  * \sa semop(2), struct misc_meta_data
 196  */
 197 void mmd_lock(void)
 198 {
 199         mutex_lock(mmd_mutex);
 200 }
 201
 202 /**
 203  * unlock the shared memory area containing the mmd struct
 204  *
 205  * \sa semop(2), struct misc_meta_data
 206  */
 207
 208 void mmd_unlock(void)
 209 {
 210         mutex_unlock(mmd_mutex);
 211 }
 212
 213 static void parse_config(int override)
 214 {
 215         char *home = para_homedir();
 216         struct stat statbuf;
 217         int ret;
 218         char *cf;
 219
 220         if (conf.config_file_given)
 221                 cf = conf.config_file_arg;
 222         else
 223                 cf = make_message("%s/.paraslash/server.conf", home);
 224         free(user_list_file);
 225         if (!conf.user_list_given)
 226                 user_list_file = make_message("%s/.paraslash/server.users", home);
 227         else
 228                 user_list_file = para_strdup(conf.user_list_arg);
 229         ret = stat(cf, &statbuf);
 230         if (ret && conf.config_file_given) {
 231                 ret = -1;
 232                 PARA_EMERG_LOG("can not stat config file %s\n", cf);
 233                 goto out;
 234         }
 235         if (!ret) {
 236                 int tmp = conf.daemon_given;
 237                 struct server_cmdline_parser_params params = {
 238                         .override = override,
 239                         .initialize = 0,
 240                         .check_required = 0,
 241                         .check_ambiguity = 0
 242                 };
 243                 server_cmdline_parser_config_file(cf, &conf, &params);
 244                 conf.daemon_given = tmp;
 245         }
 246         /* logfile */
 247         if (!conf.logfile_given && conf.daemon_given) {
 248                 ret = -1;
 249                 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
 250                 goto out;
 251         }
 252         if (conf.logfile_given)
 253                 logfile = open_log(conf.logfile_arg);
 254         ret = 1;
 255 out:
 256         free(cf);
 257         free(home);
 258         if (ret > 0)
 259                 return;
 260         free(user_list_file);
 261         user_list_file = NULL;
 262         exit(EXIT_FAILURE);
 263 }
 264
 265 static void setup_signal_handling(void)
 266 {
 267         int ret = 0;
 268
 269         signal_pipe = para_signal_init();
 270         PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
 271         ret += para_install_sighandler(SIGINT);
 272         ret += para_install_sighandler(SIGTERM);
 273         ret += para_install_sighandler(SIGHUP);
 274         ret += para_install_sighandler(SIGCHLD);
 275         ret += para_install_sighandler(SIGUSR1);
 276         signal(SIGPIPE, SIG_IGN);
 277         if (ret != 5) {
 278                 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
 279                 exit(EXIT_FAILURE);
 280         }
 281 }
 282
 283 static void init_selector(void)
 284 {
 285         int i, ret;
 286
 287         mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
 288         if (!conf.selector_given)
 289                 goto random;
 290         for (i = 0; selectors[i].name; i++) {
 291                 if (strcmp(selectors[i].name, conf.selector_arg))
 292                         continue;
 293                 PARA_NOTICE_LOG("initializing %s audio file selector\n",
 294                         selectors[i].name);
 295                 ret = selectors[i].init(&selectors[i]);
 296                 if (ret < 0) {
 297                         PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
 298                         break;
 299                 }
 300                 mmd->selector_num = i;
 301                 return;
 302         }
 303         PARA_WARNING_LOG("%s", "falling back to the random selector\n");
 304 random:
 305         mmd->selector_num = 0;
 306         selectors[0].init(&selectors[0]); /* always successful */
 307 }
 308
 309 static unsigned init_network(void)
 310 {
 311         int fd, ret = init_tcp_socket(conf.port_arg);
 312
 313         if (ret < 0)
 314                 goto err;
 315         fd = ret;
 316         ret = mark_fd_nonblock(fd);
 317         if (ret < 0)
 318                 goto err;
 319         return fd;
 320 err:
 321         PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
 322         exit(EXIT_FAILURE);
 323 }
 324
 325 static void init_random_seed(void)
 326 {
 327         int fd, ret = -1;
 328         unsigned int seed;
 329         size_t len = sizeof(unsigned int);
 330
 331         fd = open("/dev/urandom", O_RDONLY);
 332         if (fd < 0)
 333                 goto out;
 334         ret = -2;
 335         if (read(fd, &seed, len) != len)
 336                 goto out;
 337         srandom(seed);
 338         ret = 1;
 339 out:
 340         if (fd >= 0)
 341                 close(fd);
 342         if (ret > 0)
 343                 return;
 344         PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
 345                 ret);
 346         exit(EXIT_FAILURE);
 347 }
 348
 349 static uint32_t afs_socket_cookie;
 350 static int afs_socket;
 351 pid_t afs_pid;
 352
 353 static void init_afs(void)
 354 {
 355         int ret, afs_server_socket[2];
 356
 357         ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
 358         if (ret < 0)
 359                 exit(EXIT_FAILURE);
 360         afs_socket_cookie = para_random((uint32_t)-1);
 361         afs_pid = fork();
 362         if (afs_pid < 0)
 363                 exit(EXIT_FAILURE);
 364         if (!afs_pid) /* child (afs) */
 365                 afs_init(afs_socket_cookie, afs_server_socket[1]);
 366         close(afs_server_socket[1]);
 367         afs_socket = afs_server_socket[0];
 368         PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n", afs_socket,
 369                 (unsigned) afs_socket_cookie);
 370 }
 371
 372
 373 static unsigned do_inits(int argc, char **argv)
 374 {
 375         /* connector's address information */
 376         int sockfd;
 377
 378         init_random_seed();
 379         /* parse command line options */
 380         server_cmdline_parser(argc, argv, &conf);
 381         HANDLE_VERSION_FLAG("server", conf);
 382         para_drop_privileges(conf.user_arg, conf.group_arg);
 383         /* parse config file, open log and set defaults */
 384         parse_config(0);
 385         log_welcome("para_server", conf.loglevel_arg);
 386         shm_init(); /* init mmd struct */
 387         server_uptime(UPTIME_SET); /* reset server uptime */
 388         init_user_list(user_list_file);
 389         /* become daemon */
 390         if (conf.daemon_given)
 391                 daemon_init();
 392         init_selector();
 393 //      PARA_ERROR_LOG("num: %d\n", mmd->selector_num);
 394         PARA_NOTICE_LOG("%s", "initializing virtual streaming system\n");
 395         vss_init();
 396         mmd->server_pid = getpid();
 397         setup_signal_handling();
 398         init_afs();
 399         mmd_lock();
 400         /* init network socket */
 401         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 402         sockfd = init_network();
 403         PARA_NOTICE_LOG("%s", "init complete\n");
 404         return sockfd;
 405 }
 406
 407 static void change_selector(void)
 408 {
 409         int ret, old = mmd->selector_num, new = mmd->selector_change;
 410
 411         selectors[old].shutdown();
 412         ret = selectors[new].init(&selectors[new]);
 413         mmd->selector_change = -1; /* reset */
 414         if (ret >= 0) {
 415                 mmd->selector_num = new;
 416                 return;
 417         }
 418         /* init failed */
 419         PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
 420         selectors[0].init(&selectors[0]);
 421         mmd->selector_num = 0;
 422 }
 423
 424 /*
 425  * called when server gets SIGHUP or when client invokes hup command.
 426  */
 427 static void handle_sighup(void)
 428 {
 429         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 430         close_log(logfile); /* gets reopened if necessary by parse_config */
 431         logfile = NULL;
 432         parse_config(1); /* reopens log */
 433         mmd->selector_change = mmd->selector_num; /* do not change selector.. */
 434         change_selector(); /* .. just reload */
 435         init_user_list(user_list_file); /* reload user list */
 436 }
 437
 438 static void status_refresh(void)
 439 {
 440         static int prev_uptime = -1, prev_events = -1;
 441         int uptime = server_uptime(UPTIME_GET), ret = 1;
 442
 443         if (prev_events != mmd->events)
 444                 goto out;
 445         if (mmd->new_vss_status_flags != mmd->vss_status_flags)
 446                 goto out;
 447         if (uptime / 60 != prev_uptime / 60)
 448                 goto out;
 449         ret = 0;
 450 out:
 451         prev_uptime = uptime;
 452         prev_events = mmd->events;
 453         mmd->vss_status_flags = mmd->new_vss_status_flags;
 454         if (ret) {
 455                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 456                         mmd->events, mmd->audio_format);
 457                 killpg(0, SIGUSR1);
 458         }
 459 }
 460
 461 /**
 462  * the main function of para_server
 463  *
 464  * \param argc usual argument count
 465  * \param argv usual argument vector
 466  *
 467  * \return EXIT_SUCCESS or EXIT_FAILURE
 468  *
 469  */
 470 int main(int argc, char *argv[])
 471 {
 472         /* listen on sock_fd, new connection on new_fd */
 473         int sockfd, new_fd;
 474         struct sockaddr_in their_addr;
 475         int i, max_fileno, ret;
 476         pid_t chld_pid;
 477         fd_set rfds, wfds;
 478         struct timeval *timeout;
 479
 480         valid_fd_012();
 481         sockfd = do_inits(argc, argv);
 482 repeat:
 483         FD_ZERO(&rfds);
 484         FD_ZERO(&wfds);
 485         max_fileno = -1;
 486         /* check socket and signal pipe in any case */
 487         para_fd_set(sockfd, &rfds, &max_fileno);
 488         para_fd_set(signal_pipe, &rfds, &max_fileno);
 489         timeout = vss_preselect();
 490         status_refresh();
 491         for (i = 0; senders[i].name; i++) {
 492                 if (senders[i].status != SENDER_ON)
 493                         continue;
 494                 if (!senders[i].pre_select)
 495                         continue;
 496                 senders[i].pre_select( &max_fileno, &rfds, &wfds);
 497         }
 498         if (selectors[mmd->selector_num].pre_select) {
 499                 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
 500                 max_fileno = PARA_MAX(max_fileno, ret);
 501         }
 502         mmd_unlock();
 503         ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
 504         mmd_lock();
 505         if (mmd->selector_change >= 0)
 506                 change_selector();
 507         if (selectors[mmd->selector_num].post_select)
 508                 selectors[mmd->selector_num].post_select(&rfds, &wfds);
 509         if (ret < 0)
 510                 goto repeat;
 511         for (i = 0; senders[i].name; i++) {
 512                 if (senders[i].status != SENDER_ON)
 513                         continue;
 514                 if (!senders[i].post_select)
 515                         continue;
 516                 senders[i].post_select(&rfds, &wfds);
 517         }
 518         vss_send_chunk();
 519         status_refresh();
 520         if (FD_ISSET(signal_pipe, &rfds)) {
 521                 int sig;
 522                 pid_t pid;
 523                 sig = para_next_signal();
 524                 switch (sig) {
 525                 case SIGHUP:
 526                         handle_sighup();
 527                         break;
 528                 case SIGCHLD:
 529                         for (;;) {
 530                                 pid = para_reap_child();
 531                                 if (pid <= 0)
 532                                         break;
 533                                 if (pid != afs_pid)
 534                                         continue;
 535                                 PARA_EMERG_LOG("fatal: afs died\n");
 536                                 goto genocide;
 537                         }
 538                         break;
 539                 /* die on sigint/sigterm. Kill all children too. */
 540                 case SIGINT:
 541                 case SIGTERM:
 542                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 543 genocide:
 544                         kill(0, SIGTERM);
 545                         selectors[mmd->selector_num].shutdown();
 546                         mutex_destroy(mmd_mutex);
 547                         shm_detach(mmd);
 548                         shm_destroy(mmd_shm_id);
 549
 550                         exit(EXIT_FAILURE);
 551                 }
 552         }
 553         if (mmd->sender_cmd_data.cmd_num >= 0) {
 554                 int num = mmd->sender_cmd_data.cmd_num,
 555                         s = mmd->sender_cmd_data.sender_num;
 556
 557                 if (senders[s].client_cmds[num])
 558                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 559                 mmd->sender_cmd_data.cmd_num = -1;
 560         }
 561         if (!FD_ISSET(sockfd, &rfds))
 562                 goto repeat;
 563
 564         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 565         if (new_fd < 0)
 566                 goto repeat;
 567         PARA_INFO_LOG("got connection from %s, forking\n",
 568                 inet_ntoa(their_addr.sin_addr));
 569         mmd->num_connects++;
 570         mmd->active_connections++;
 571         random();
 572         chld_pid = fork();
 573         if (chld_pid < 0) {
 574                 PARA_CRIT_LOG("%s", "fork failed\n");
 575                 goto repeat;
 576         }
 577         if (chld_pid) {
 578                 close(new_fd);
 579                 /* parent keeps accepting connections */
 580                 goto repeat;
 581         }
 582         alarm(ALARM_TIMEOUT);
 583         close_listed_fds();
 584         close(sockfd); /* child doesn't need the listener */
 585         /*
 586          * put info on who we are serving into argv[0] to make
 587          * client ip visible in top/ps
 588          */
 589         for (i = argc - 1; i >= 0; i--)
 590                 memset(argv[i], 0, strlen(argv[i]));
 591         sprintf(argv[0], "para_server (serving %s)",
 592                 inet_ntoa(their_addr.sin_addr));
 593         return handle_connect(new_fd, &their_addr);
 594 }