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 "list.h"
  35 #include "sched.h"
  36 #include "signal.h"
  37 #include "user_list.h"
  38 #include "afs.h"
  39
  40 /** define the array of error lists needed by para_server */
  41 INIT_SERVER_ERRLISTS;
  42
  43 /** shut down non-authorized connections after that many seconds */
  44 #define ALARM_TIMEOUT 10
  45
  46 /**
  47  * pointer to shared memory area for communication between para_server
  48  * and its children. exported to vss.c. command.c and to all selectors.
  49  */
  50 struct misc_meta_data *mmd;
  51
  52 /**
  53  * the configuration of para_server
  54  *
  55  * It also contains the options for all audio file selectors, audio format handler
  56  * and all supported senders.
  57  */
  58 struct server_args_info conf;
  59
  60 /** the file containing user information (public key, permissions) */
  61 char *user_list_file = NULL;
  62
  63 extern void dccp_send_init(struct sender *);
  64 extern void http_send_init(struct sender *);
  65 extern void ortp_send_init(struct sender *);
  66
  67 /* TODO: This is better handled by autoconf */
  68 /** the list of supported audio file selectors */
  69 struct audio_file_selector selectors[] = {
  70         {
  71                 .name = "random",
  72                 .init = random_selector_init,
  73                 .update_audio_file = NULL,
  74         },
  75         {
  76                 .name = "playlist",
  77                 .init = playlist_selector_init,
  78                 .update_audio_file = NULL,
  79                 .pre_select = NULL,
  80                 .post_select = NULL,
  81         },
  82 #ifdef HAVE_MYSQL
  83         {
  84                 .name = "mysql",
  85                 .init = mysql_selector_init,
  86                 .update_audio_file = NULL,
  87                 .pre_select = NULL,
  88                 .post_select = NULL,
  89         },
  90 #endif
  91         {
  92                 .name = NULL,
  93         }
  94 };
  95
  96 /** the list of supported senders */
  97 struct sender senders[] = {
  98         {
  99                 .name = "http",
 100                 .init = http_send_init,
 101         },
 102         {
 103                 .name = "dccp",
 104                 .init = dccp_send_init,
 105         },
 106 #ifdef HAVE_ORTP
 107         {
 108                 .name = "ortp",
 109                 .init = ortp_send_init,
 110         },
 111 #endif
 112         {
 113                 .name = NULL,
 114         }
 115 };
 116
 117
 118 /* global variables for server-internal use */
 119 static FILE *logfile;
 120 static int mmd_mutex, mmd_shm_id;
 121 static int signal_pipe;
 122
 123 /**
 124  * para_server's log function
 125  *
 126  * \param ll the log level
 127  * \param fmt the format string describing the log message
 128  */
 129 void para_log(int ll, const char* fmt,...)
 130 {
 131         va_list argp;
 132         FILE *outfd;
 133         struct tm *tm;
 134         time_t t1;
 135         char str[MAXLINE] = "";
 136         pid_t mypid;
 137
 138         if (ll < conf.loglevel_arg)
 139                 return;
 140         outfd = logfile? logfile : stderr;
 141         time(&t1);
 142         tm = localtime(&t1);
 143         strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
 144         fprintf(outfd, "%s ", str);
 145         if (conf.loglevel_arg <= INFO)
 146                 fprintf(outfd, "%i: ", ll);
 147         mypid = getpid();
 148         if (conf.loglevel_arg <= INFO)
 149                 fprintf(outfd, "(%d) ", mypid);
 150         va_start(argp, fmt);
 151         vfprintf(outfd, fmt, argp);
 152         va_end(argp);
 153 }
 154
 155 /*
 156  * setup shared memory area and get mutex for locking
 157  */
 158 static void shm_init(void)
 159 {
 160         void *shm;
 161         int ret = shm_new(sizeof(struct misc_meta_data));
 162
 163         if (ret < 0)
 164                 goto err_out;
 165
 166         ret = shm_attach(ret, ATTACH_RW, &shm);
 167         if (ret < 0)
 168                 goto err_out;
 169         mmd = shm;
 170         mmd_shm_id = ret;
 171
 172         ret = mutex_new();
 173         if (ret < 0)
 174                 goto err_out;
 175         mmd_mutex = ret;
 176
 177         mmd->selector_num = 0;
 178         mmd->num_played = 0;
 179         mmd->num_commands = 0;
 180         mmd->events = 0;
 181         mmd->num_connects = 0;
 182         mmd->active_connections = 0;
 183         strcpy(mmd->filename, "(none)");
 184         mmd->audio_format = -1;
 185         mmd->vss_status_flags = VSS_NEXT;
 186         mmd->new_vss_status_flags = VSS_NEXT;
 187         mmd->sender_cmd_data.cmd_num = -1;
 188         return;
 189 err_out:
 190         PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
 191         exit(EXIT_FAILURE);
 192 }
 193
 194 /**
 195  * lock the shared memory area containing the mmd struct
 196  *
 197  * \sa semop(2), struct misc_meta_data
 198  */
 199 void mmd_lock(void)
 200 {
 201         mutex_lock(mmd_mutex);
 202 }
 203
 204 /**
 205  * unlock the shared memory area containing the mmd struct
 206  *
 207  * \sa semop(2), struct misc_meta_data
 208  */
 209
 210 void mmd_unlock(void)
 211 {
 212         mutex_unlock(mmd_mutex);
 213 }
 214
 215 static void parse_config(int override)
 216 {
 217         char *home = para_homedir();
 218         struct stat statbuf;
 219         int ret;
 220         char *cf;
 221
 222         if (conf.config_file_given)
 223                 cf = conf.config_file_arg;
 224         else
 225                 cf = make_message("%s/.paraslash/server.conf", home);
 226         free(user_list_file);
 227         if (!conf.user_list_given)
 228                 user_list_file = make_message("%s/.paraslash/server.users", home);
 229         else
 230                 user_list_file = para_strdup(conf.user_list_arg);
 231         ret = stat(cf, &statbuf);
 232         if (ret && conf.config_file_given) {
 233                 ret = -1;
 234                 PARA_EMERG_LOG("can not stat config file %s\n", cf);
 235                 goto out;
 236         }
 237         if (!ret) {
 238                 int tmp = conf.daemon_given;
 239                 struct server_cmdline_parser_params params = {
 240                         .override = override,
 241                         .initialize = 0,
 242                         .check_required = 0,
 243                         .check_ambiguity = 0
 244                 };
 245                 server_cmdline_parser_config_file(cf, &conf, &params);
 246                 conf.daemon_given = tmp;
 247         }
 248         /* logfile */
 249         if (!conf.logfile_given && conf.daemon_given) {
 250                 ret = -1;
 251                 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
 252                 goto out;
 253         }
 254         if (conf.logfile_given)
 255                 logfile = open_log(conf.logfile_arg);
 256         ret = 1;
 257 out:
 258         free(cf);
 259         free(home);
 260         if (ret > 0)
 261                 return;
 262         free(user_list_file);
 263         user_list_file = NULL;
 264         exit(EXIT_FAILURE);
 265 }
 266
 267 static void setup_signal_handling(void)
 268 {
 269         int ret = 0;
 270
 271         signal_pipe = para_signal_init();
 272         PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
 273         ret += para_install_sighandler(SIGINT);
 274         ret += para_install_sighandler(SIGTERM);
 275         ret += para_install_sighandler(SIGHUP);
 276         ret += para_install_sighandler(SIGCHLD);
 277         ret += para_install_sighandler(SIGUSR1);
 278         signal(SIGPIPE, SIG_IGN);
 279         if (ret != 5) {
 280                 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
 281                 exit(EXIT_FAILURE);
 282         }
 283 }
 284
 285 static void init_selector(void)
 286 {
 287         int i, ret;
 288
 289         mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
 290         if (!conf.selector_given)
 291                 goto random;
 292         for (i = 0; selectors[i].name; i++) {
 293                 if (strcmp(selectors[i].name, conf.selector_arg))
 294                         continue;
 295                 PARA_NOTICE_LOG("initializing %s audio file selector\n",
 296                         selectors[i].name);
 297                 ret = selectors[i].init(&selectors[i]);
 298                 if (ret < 0) {
 299                         PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
 300                         break;
 301                 }
 302                 mmd->selector_num = i;
 303                 return;
 304         }
 305         PARA_WARNING_LOG("%s", "falling back to the random selector\n");
 306 random:
 307         mmd->selector_num = 0;
 308         selectors[0].init(&selectors[0]); /* always successful */
 309 }
 310
 311 static unsigned init_network(void)
 312 {
 313         int fd, ret = init_tcp_socket(conf.port_arg);
 314
 315         if (ret < 0)
 316                 goto err;
 317         fd = ret;
 318         ret = mark_fd_nonblock(fd);
 319         if (ret < 0)
 320                 goto err;
 321         return fd;
 322 err:
 323         PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
 324         exit(EXIT_FAILURE);
 325 }
 326
 327 static void init_random_seed(void)
 328 {
 329         int fd, ret = -1;
 330         unsigned int seed;
 331         size_t len = sizeof(unsigned int);
 332
 333         fd = open("/dev/urandom", O_RDONLY);
 334         if (fd < 0)
 335                 goto out;
 336         ret = -2;
 337         if (read(fd, &seed, len) != len)
 338                 goto out;
 339         srandom(seed);
 340         ret = 1;
 341 out:
 342         if (fd >= 0)
 343                 close(fd);
 344         if (ret > 0)
 345                 return;
 346         PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
 347                 ret);
 348         exit(EXIT_FAILURE);
 349 }
 350
 351 uint32_t afs_socket_cookie;
 352 static int afs_socket;
 353 pid_t afs_pid;
 354
 355 static void init_afs(void)
 356 {
 357         int ret, afs_server_socket[2];
 358
 359         ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
 360         if (ret < 0)
 361                 exit(EXIT_FAILURE);
 362         afs_socket_cookie = para_random((uint32_t)-1);
 363         afs_pid = fork();
 364         if (afs_pid < 0)
 365                 exit(EXIT_FAILURE);
 366         if (!afs_pid) /* child (afs) */
 367                 afs_init(afs_socket_cookie, afs_server_socket[1]);
 368         close(afs_server_socket[1]);
 369         afs_socket = afs_server_socket[0];
 370         PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n", afs_socket,
 371                 (unsigned) afs_socket_cookie);
 372 }
 373
 374
 375 static unsigned do_inits(int argc, char **argv)
 376 {
 377         /* connector's address information */
 378         int sockfd;
 379
 380         init_random_seed();
 381         /* parse command line options */
 382         server_cmdline_parser(argc, argv, &conf);
 383         HANDLE_VERSION_FLAG("server", conf);
 384         para_drop_privileges(conf.user_arg, conf.group_arg);
 385         /* parse config file, open log and set defaults */
 386         parse_config(0);
 387         log_welcome("para_server", conf.loglevel_arg);
 388         shm_init(); /* init mmd struct */
 389         server_uptime(UPTIME_SET); /* reset server uptime */
 390         init_user_list(user_list_file);
 391         /* become daemon */
 392         if (conf.daemon_given)
 393                 daemon_init();
 394         init_selector();
 395 //      PARA_ERROR_LOG("num: %d\n", mmd->selector_num);
 396         PARA_NOTICE_LOG("%s", "initializing virtual streaming system\n");
 397         vss_init();
 398         mmd->server_pid = getpid();
 399         setup_signal_handling();
 400         init_afs();
 401         mmd_lock();
 402         /* init network socket */
 403         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 404         sockfd = init_network();
 405         PARA_NOTICE_LOG("%s", "init complete\n");
 406         return sockfd;
 407 }
 408
 409 static void change_selector(void)
 410 {
 411         int ret, old = mmd->selector_num, new = mmd->selector_change;
 412
 413         selectors[old].shutdown();
 414         ret = selectors[new].init(&selectors[new]);
 415         mmd->selector_change = -1; /* reset */
 416         if (ret >= 0) {
 417                 mmd->selector_num = new;
 418                 return;
 419         }
 420         /* init failed */
 421         PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
 422         selectors[0].init(&selectors[0]);
 423         mmd->selector_num = 0;
 424 }
 425
 426 /*
 427  * called when server gets SIGHUP or when client invokes hup command.
 428  */
 429 static void handle_sighup(void)
 430 {
 431         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 432         close_log(logfile); /* gets reopened if necessary by parse_config */
 433         logfile = NULL;
 434         parse_config(1); /* reopens log */
 435         mmd->selector_change = mmd->selector_num; /* do not change selector.. */
 436         change_selector(); /* .. just reload */
 437         init_user_list(user_list_file); /* reload user list */
 438 }
 439
 440 static void status_refresh(void)
 441 {
 442         static int prev_uptime = -1, prev_events = -1;
 443         int uptime = server_uptime(UPTIME_GET), ret = 1;
 444
 445         if (prev_events != mmd->events)
 446                 goto out;
 447         if (mmd->new_vss_status_flags != mmd->vss_status_flags)
 448                 goto out;
 449         if (uptime / 60 != prev_uptime / 60)
 450                 goto out;
 451         ret = 0;
 452 out:
 453         prev_uptime = uptime;
 454         prev_events = mmd->events;
 455         mmd->vss_status_flags = mmd->new_vss_status_flags;
 456         if (ret) {
 457                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 458                         mmd->events, mmd->audio_format);
 459                 killpg(0, SIGUSR1);
 460         }
 461 }
 462
 463 /**
 464  * the main function of para_server
 465  *
 466  * \param argc usual argument count
 467  * \param argv usual argument vector
 468  *
 469  * \return EXIT_SUCCESS or EXIT_FAILURE
 470  *
 471  */
 472 int main(int argc, char *argv[])
 473 {
 474         /* listen on sock_fd, new connection on new_fd */
 475         int sockfd, new_fd;
 476         struct sockaddr_in their_addr;
 477         int i, max_fileno, ret;
 478         pid_t chld_pid;
 479         fd_set rfds, wfds;
 480         struct timeval *timeout;
 481
 482         valid_fd_012();
 483         sockfd = do_inits(argc, argv);
 484 repeat:
 485         FD_ZERO(&rfds);
 486         FD_ZERO(&wfds);
 487         max_fileno = -1;
 488         /* check socket and signal pipe in any case */
 489         para_fd_set(sockfd, &rfds, &max_fileno);
 490         para_fd_set(signal_pipe, &rfds, &max_fileno);
 491         timeout = vss_preselect();
 492         status_refresh();
 493         for (i = 0; senders[i].name; i++) {
 494                 if (senders[i].status != SENDER_ON)
 495                         continue;
 496                 if (!senders[i].pre_select)
 497                         continue;
 498                 senders[i].pre_select( &max_fileno, &rfds, &wfds);
 499         }
 500         if (selectors[mmd->selector_num].pre_select) {
 501                 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
 502                 max_fileno = PARA_MAX(max_fileno, ret);
 503         }
 504         mmd_unlock();
 505         ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
 506         mmd_lock();
 507         if (mmd->selector_change >= 0)
 508                 change_selector();
 509         if (selectors[mmd->selector_num].post_select)
 510                 selectors[mmd->selector_num].post_select(&rfds, &wfds);
 511         if (ret < 0)
 512                 goto repeat;
 513         for (i = 0; senders[i].name; i++) {
 514                 if (senders[i].status != SENDER_ON)
 515                         continue;
 516                 if (!senders[i].post_select)
 517                         continue;
 518                 senders[i].post_select(&rfds, &wfds);
 519         }
 520         vss_send_chunk();
 521         status_refresh();
 522         if (FD_ISSET(signal_pipe, &rfds)) {
 523                 int sig;
 524                 pid_t pid;
 525                 sig = para_next_signal();
 526                 switch (sig) {
 527                 case SIGHUP:
 528                         handle_sighup();
 529                         break;
 530                 case SIGCHLD:
 531                         for (;;) {
 532                                 pid = para_reap_child();
 533                                 if (pid <= 0)
 534                                         break;
 535                                 if (pid != afs_pid)
 536                                         continue;
 537                                 PARA_EMERG_LOG("fatal: afs died\n");
 538                                 goto genocide;
 539                         }
 540                         break;
 541                 /* die on sigint/sigterm. Kill all children too. */
 542                 case SIGINT:
 543                 case SIGTERM:
 544                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 545 genocide:
 546                         kill(0, SIGTERM);
 547                         selectors[mmd->selector_num].shutdown();
 548                         mutex_destroy(mmd_mutex);
 549                         shm_detach(mmd);
 550                         shm_destroy(mmd_shm_id);
 551
 552                         exit(EXIT_FAILURE);
 553                 }
 554         }
 555         if (mmd->sender_cmd_data.cmd_num >= 0) {
 556                 int num = mmd->sender_cmd_data.cmd_num,
 557                         s = mmd->sender_cmd_data.sender_num;
 558
 559                 if (senders[s].client_cmds[num])
 560                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 561                 mmd->sender_cmd_data.cmd_num = -1;
 562         }
 563         if (!FD_ISSET(sockfd, &rfds))
 564                 goto repeat;
 565
 566         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 567         if (new_fd < 0)
 568                 goto repeat;
 569         PARA_INFO_LOG("got connection from %s, forking\n",
 570                 inet_ntoa(their_addr.sin_addr));
 571         mmd->num_connects++;
 572         mmd->active_connections++;
 573         random();
 574         chld_pid = fork();
 575         if (chld_pid < 0) {
 576                 PARA_CRIT_LOG("%s", "fork failed\n");
 577                 goto repeat;
 578         }
 579         if (chld_pid) {
 580                 close(new_fd);
 581                 /* parent keeps accepting connections */
 582                 goto repeat;
 583         }
 584         alarm(ALARM_TIMEOUT);
 585         close_listed_fds();
 586         close(sockfd); /* child doesn't need the listener */
 587         /*
 588          * put info on who we are serving into argv[0] to make
 589          * client ip visible in top/ps
 590          */
 591         for (i = argc - 1; i >= 0; i--)
 592                 memset(argv[i], 0, strlen(argv[i]));
 593         sprintf(argv[0], "para_server (serving %s)",
 594                 inet_ntoa(their_addr.sin_addr));
 595         return handle_connect(new_fd, &their_addr);
 596 }