server.c

   1 /*
   2  * Copyright (C) 1997-2006 Andre Noll <maan@systemlinux.org>
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     This program is distributed in the hope that it will be useful,
  10  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *     GNU General Public License for more details.
  13  *
  14  *     You should have received a copy of the GNU General Public License
  15  *     along with this program; if not, write to the Free Software
  16  *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  17  */
  18
  19 /** \file server.c Paraslash's main server */
  20
  21
  22 /** \mainpage Paraslash API Reference
  23  *
  24  *  Good starting points for reading are probably \ref audio_file_selector,
  25  *  \ref sender, \ref receiver, \ref receiver_node, \ref filter, \ref
  26  *  filter_node.
  27  *
  28  */
  29
  30
  31
  32 #include "server.cmdline.h"
  33 #include "db.h"
  34 #include "server.h"
  35 #include "afs.h"
  36 #include "config.h"
  37 #include "close_on_fork.h"
  38 #include "send.h"
  39 #include "error.h"
  40 #include "net.h"
  41 #include "daemon.h"
  42 #include "string.h"
  43 #include "ipc.h"
  44
  45 /** define the array of error lists needed by para_server */
  46 INIT_SERVER_ERRLISTS;
  47
  48 /** shut down non-authorized connections after that many seconds */
  49 #define ALARM_TIMEOUT 10
  50
  51 /* these are exported to afs.c. command.c and to all selectors */
  52 struct misc_meta_data *mmd;
  53 /** the configuration of para_server
  54  *
  55  * It also contains the options for all audio file selectors and all supported
  56  * senders.
  57 */
  58 struct gengetopt_args_info conf;
  59 char *user_list = NULL;
  60 extern void http_send_init(struct sender *);
  61 extern void ortp_send_init(struct sender *);
  62 extern struct audio_format afl[];
  63
  64 /** the list of supported audio file selectors */
  65 struct audio_file_selector dblist[] = {
  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 #ifdef HAVE_ORTP
  99         {
 100                 .name = "ortp",
 101                 .init = ortp_send_init,
 102         },
 103 #endif
 104         {
 105                 .name = NULL,
 106         }
 107 };
 108
 109
 110 /* global variables for server-internal use */
 111 static FILE *logfile;
 112 static int mmd_mutex, mmd_shm_id;
 113 static int signal_pipe;
 114
 115 /**
 116  * para_server's log function
 117  *
 118  * \param ll the log level
 119  * \param fmt the format string describing the log message
 120  */
 121 void para_log(int ll, char* fmt,...)
 122 {
 123         va_list argp;
 124         FILE *outfd;
 125         struct tm *tm;
 126         time_t t1;
 127         char str[MAXLINE] = "";
 128         pid_t mypid;
 129
 130         if (ll < conf.loglevel_arg)
 131                 return;
 132         if (!logfile) {
 133                 if (ll < WARNING)
 134                         outfd = stdout;
 135                 else
 136                         outfd = stderr;
 137         } else
 138                 outfd = logfile;
 139         if (conf.daemon_given && !logfile)
 140                 return;
 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->afs_status_flags = AFS_NEXT;
 186         mmd->new_afs_status_flags = AFS_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);
 227         if (!conf.user_list_given)
 228                 user_list = make_message("%s/.paraslash/server.users", home);
 229         else
 230                 user_list = 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                 cmdline_parser_configfile(cf, &conf, override, 0, 0);
 240                 conf.daemon_given = tmp;
 241         }
 242         /* logfile */
 243         if (!conf.logfile_given && conf.daemon_given) {
 244                 ret = -1;
 245                 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
 246                 goto out;
 247         }
 248         if (conf.logfile_given)
 249                 logfile = open_log(conf.logfile_arg);
 250         ret = 1;
 251 out:
 252         free(cf);
 253         free(home);
 254         if (ret > 0)
 255                 return;
 256         free(user_list);
 257         user_list = NULL;
 258         exit(EXIT_FAILURE);
 259 }
 260
 261 static void setup_signal_handling(void)
 262 {
 263         int ret = 0;
 264
 265         signal_pipe = para_signal_init();
 266 //      fcntl(signal_pipe, F_SETFL, O_NONBLOCK);
 267         PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
 268         ret += para_install_sighandler(SIGINT);
 269         ret += para_install_sighandler(SIGTERM);
 270         ret += para_install_sighandler(SIGHUP);
 271         ret += para_install_sighandler(SIGCHLD);
 272         ret += para_install_sighandler(SIGUSR1);
 273         signal(SIGPIPE, SIG_IGN);
 274         if (ret != 5) {
 275                 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
 276                 exit(EXIT_FAILURE);
 277         }
 278 }
 279
 280 static void init_selector(void)
 281 {
 282         int i, ret;
 283
 284         mmd->dbt_change = -1; /* no change nec., set to new dbt num by com_cdt */
 285         if (!conf.selector_given)
 286                 goto random;
 287         for (i = 0; dblist[i].name; i++) {
 288                 if (strcmp(dblist[i].name, conf.selector_arg))
 289                         continue;
 290                 PARA_NOTICE_LOG("initializing %s audio file selector\n",
 291                         dblist[i].name);
 292                 ret = dblist[i].init(&dblist[i]);
 293                 if (ret < 0) {
 294                         PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
 295                         break;
 296                 }
 297                 mmd->selector_num = i;
 298                 return;
 299         }
 300         PARA_WARNING_LOG("%s", "falling back to the random selector\n");
 301 random:
 302         mmd->selector_num = 0;
 303         dblist[0].init(&dblist[0]); /* always successful */
 304 }
 305
 306 static unsigned init_network(void)
 307 {
 308         int sockfd = init_tcp_socket(conf.port_arg);
 309
 310         if (sockfd < 0)
 311                 exit(EXIT_FAILURE);
 312         return sockfd;
 313 }
 314
 315 static void init_random_seed(void)
 316 {
 317         int fd, ret = -1, len = sizeof(unsigned int);
 318         unsigned int seed;
 319
 320         fd = open("/dev/random", O_RDONLY);
 321         if (fd < 0)
 322                 goto out;
 323         ret = -2;
 324         if (read(fd, &seed, len) != len)
 325                 goto out;
 326         srandom(seed);
 327         ret = 1;
 328 out:
 329         if (fd >= 0)
 330                 close(fd);
 331         if (ret > 0)
 332                 return;
 333         PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
 334                 ret);
 335         exit(EXIT_FAILURE);
 336 }
 337
 338 static unsigned do_inits(int argc, char **argv)
 339 {
 340         /* connector's address information */
 341         int sockfd;
 342
 343         init_random_seed();
 344         /* parse command line options */
 345         cmdline_parser(argc, argv, &conf);
 346         para_drop_privileges(conf.user_arg);
 347         /* parse config file, open log and set defaults */
 348         parse_config(0);
 349         log_welcome("para_server", conf.loglevel_arg);
 350         shm_init(); /* init mmd struct */
 351         server_uptime(UPTIME_SET); /* reset server uptime */
 352         /* become daemon */
 353         if (conf.daemon_given)
 354                 daemon_init();
 355         init_selector();
 356         PARA_NOTICE_LOG("%s", "initializing audio file sender\n");
 357         /* audio file sender */
 358         afs_init();
 359         mmd->server_pid = getpid();
 360         setup_signal_handling();
 361         mmd_lock();
 362         /* init network socket */
 363         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 364         sockfd = init_network();
 365         if (conf.autoplay_given) {
 366                 mmd->afs_status_flags |= AFS_PLAYING;
 367                 mmd->new_afs_status_flags |= AFS_PLAYING;
 368         }
 369         PARA_NOTICE_LOG("%s", "init complete\n");
 370         return sockfd;
 371 }
 372
 373 static void handle_dbt_change(void)
 374 {
 375         int ret, old = mmd->selector_num, new = mmd->dbt_change;
 376
 377         dblist[old].shutdown();
 378         ret = dblist[new].init(&dblist[new]);
 379         mmd->dbt_change = -1; /* reset */
 380         if (ret >= 0) {
 381                 mmd->selector_num = new;
 382                 return;
 383         }
 384         /* init failed */
 385         PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
 386         dblist[0].init(&dblist[0]);
 387         mmd->selector_num = 0;
 388 }
 389
 390 /*
 391  * called when server gets SIGHUP or when client invokes hup command.
 392  */
 393 static void handle_sighup(void)
 394 {
 395         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 396         close_log(logfile); /* gets reopened if necessary by parse_config */
 397         logfile = NULL;
 398         parse_config(1); /* reopens log */
 399         mmd->dbt_change = mmd->selector_num; /* do not change selector */
 400         handle_dbt_change(); /* reload selector */
 401 }
 402
 403 static void status_refresh(void)
 404 {
 405         static int prev_uptime = -1, prev_events = -1;
 406         int uptime = server_uptime(UPTIME_GET), ret = 1;
 407
 408         if (prev_events != mmd->events)
 409                 goto out;
 410         if (mmd->new_afs_status_flags != mmd->afs_status_flags)
 411                 goto out;
 412         if (uptime / 60 != prev_uptime / 60)
 413                 goto out;
 414         ret = 0;
 415 out:
 416         prev_uptime = uptime;
 417         prev_events = mmd->events;
 418         mmd->afs_status_flags = mmd->new_afs_status_flags;
 419         if (ret) {
 420                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 421                         mmd->events, mmd->audio_format);
 422                 killpg(0, SIGUSR1);
 423         }
 424 }
 425
 426 /*
 427  * MAIN
 428  */
 429 int main(int argc, char *argv[])
 430 {
 431         /* listen on sock_fd, new connection on new_fd */
 432         int sockfd, new_fd;
 433         struct sockaddr_in their_addr;
 434         int err, i, max_fileno, ret;
 435         pid_t chld_pid;
 436         fd_set rfds, wfds;
 437         struct timeval *timeout;
 438
 439         valid_fd_012();
 440         sockfd = do_inits(argc, argv);
 441 repeat:
 442         /* check socket and signal pipe in any case */
 443         FD_ZERO(&rfds);
 444         FD_ZERO(&wfds);
 445         FD_SET(sockfd, &rfds);
 446         max_fileno = sockfd;
 447         FD_SET(signal_pipe, &rfds);
 448         max_fileno = MAX(max_fileno, signal_pipe);
 449
 450         timeout = afs_preselect();
 451         status_refresh();
 452         for (i = 0; senders[i].name; i++) {
 453                 if (senders[i].status != SENDER_ON)
 454                         continue;
 455                 if (!senders[i].pre_select)
 456                         continue;
 457                 senders[i].pre_select(mmd->audio_format >= 0?
 458                         &afl[mmd->audio_format] : NULL,
 459                         &max_fileno,
 460                         &rfds, &wfds);
 461         }
 462         if (dblist[mmd->selector_num].pre_select) {
 463                 ret = dblist[mmd->selector_num].pre_select(&rfds, &wfds);
 464                 max_fileno = MAX(max_fileno, ret);
 465         }
 466         mmd_unlock();
 467 //      PARA_DEBUG_LOG("%s: select (max = %i)\n", __func__, max_fileno);
 468         ret = select(max_fileno + 1, &rfds, &wfds, NULL, timeout);
 469         err = errno;
 470         //PARA_DEBUG_LOG("%s: select returned  %i\n", __func__, ret);
 471         mmd_lock();
 472         if (mmd->dbt_change >= 0)
 473                 handle_dbt_change();
 474         if (dblist[mmd->selector_num].post_select)
 475                 dblist[mmd->selector_num].post_select(&rfds, &wfds);
 476         if (ret < 0 && err == EINTR)
 477                 goto repeat;
 478         if (ret < 0) {
 479                 PARA_CRIT_LOG("select error (%s)\n", strerror(err));
 480                 goto repeat;
 481         }
 482         for (i = 0; senders[i].name; i++) {
 483                 if (senders[i].status != SENDER_ON)
 484                         continue;
 485                 if (!senders[i].post_select)
 486                         continue;
 487                 senders[i].post_select(mmd->audio_format >= 0?
 488                         &afl[mmd->audio_format] : NULL,
 489                         &rfds, &wfds);
 490         }
 491         if (!ret) {
 492                 afs_send_chunk();
 493                 status_refresh();
 494         }
 495         if (FD_ISSET(signal_pipe, &rfds)) {
 496                 int sig;
 497                 sig = para_next_signal();
 498                 switch (sig) {
 499                 case SIGHUP:
 500                         handle_sighup();
 501                         break;
 502                 case SIGCHLD:
 503                         para_reap_children();
 504                         break;
 505                 /* die on sigint/sigterm. Kill all children too. */
 506                 case SIGINT:
 507                 case SIGTERM:
 508                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 509                         kill(0, SIGTERM);
 510                         dblist[mmd->selector_num].shutdown();
 511                         mutex_destroy(mmd_mutex);
 512                         shm_detach(mmd);
 513                         shm_destroy(mmd_shm_id);
 514                         exit(EXIT_FAILURE);
 515                 }
 516         }
 517         if (mmd->sender_cmd_data.cmd_num >= 0) {
 518                 int num = mmd->sender_cmd_data.cmd_num,
 519                         s = mmd->sender_cmd_data.sender_num;
 520
 521                 if (senders[s].client_cmds[num])
 522                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 523                 mmd->sender_cmd_data.cmd_num = -1;
 524         }
 525         if (!FD_ISSET(sockfd, &rfds))
 526                 goto repeat;
 527
 528         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 529         if (new_fd < 0)
 530                 goto repeat;
 531         PARA_INFO_LOG("got connection from %s, forking\n",
 532                 inet_ntoa(their_addr.sin_addr));
 533         mmd->num_connects++;
 534         mmd->active_connections++;
 535         random();
 536         chld_pid = fork();
 537         if (chld_pid < 0) {
 538                 PARA_CRIT_LOG("%s", "fork failed\n");
 539                 goto repeat;
 540         }
 541         if (chld_pid) {
 542                 close(new_fd);
 543                 /* parent keeps accepting connections */
 544                 goto repeat;
 545         }
 546         alarm(ALARM_TIMEOUT);
 547         close_listed_fds();
 548         close(sockfd); /* child doesn't need the listener */
 549         /*
 550          * put info on who we are serving into argv[0] to make
 551          * client ip visible in top/ps
 552          */
 553         for (i = argc - 1; i >= 0; i--)
 554                 memset(argv[i], 0, strlen(argv[i]));
 555         sprintf(argv[0], "para_server (serving %s)",
 556                 inet_ntoa(their_addr.sin_addr));
 557         return handle_connect(new_fd, &their_addr);
 558 }