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