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 #include "fd.h"
  45
  46 /** define the array of error lists needed by para_server */
  47 INIT_SERVER_ERRLISTS;
  48
  49 /** shut down non-authorized connections after that many seconds */
  50 #define ALARM_TIMEOUT 10
  51
  52 /* these are exported to afs.c. command.c and to all selectors */
  53 struct misc_meta_data *mmd;
  54 /** the configuration of para_server
  55  *
  56  * It also contains the options for all audio file selectors and all supported
  57  * senders.
  58 */
  59 struct gengetopt_args_info conf;
  60 char *user_list = NULL;
  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 extern struct audio_format afl[];
  65
  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         if (!logfile) {
 139                 if (ll < WARNING)
 140                         outfd = stdout;
 141                 else
 142                         outfd = stderr;
 143         } else
 144                 outfd = logfile;
 145         if (conf.daemon_given && !logfile)
 146                 return;
 147         time(&t1);
 148         tm = localtime(&t1);
 149         strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
 150         fprintf(outfd, "%s ", str);
 151         if (conf.loglevel_arg <= INFO)
 152                 fprintf(outfd, "%i: ", ll);
 153         mypid = getpid();
 154         if (conf.loglevel_arg <= INFO)
 155                 fprintf(outfd, "(%d) ", mypid);
 156         va_start(argp, fmt);
 157         vfprintf(outfd, fmt, argp);
 158         va_end(argp);
 159 }
 160
 161 /*
 162  * setup shared memory area and get mutex for locking
 163  */
 164 static void shm_init(void)
 165 {
 166         void *shm;
 167         int ret = shm_new(sizeof(struct misc_meta_data));
 168
 169         if (ret < 0)
 170                 goto err_out;
 171
 172         ret = shm_attach(ret, ATTACH_RW, &shm);
 173         if (ret < 0)
 174                 goto err_out;
 175         mmd = shm;
 176         mmd_shm_id = ret;
 177
 178         ret = mutex_new();
 179         if (ret < 0)
 180                 goto err_out;
 181         mmd_mutex = ret;
 182
 183         mmd->selector_num = 0;
 184         mmd->num_played = 0;
 185         mmd->num_commands = 0;
 186         mmd->events = 0;
 187         mmd->num_connects = 0;
 188         mmd->active_connections = 0;
 189         strcpy(mmd->filename, "(none)");
 190         mmd->audio_format = -1;
 191         mmd->afs_status_flags = AFS_NEXT;
 192         mmd->new_afs_status_flags = AFS_NEXT;
 193         mmd->sender_cmd_data.cmd_num = -1;
 194         return;
 195 err_out:
 196         PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
 197         exit(EXIT_FAILURE);
 198 }
 199
 200 /**
 201  * lock the shared memory area containing the mmd struct
 202  *
 203  * \sa semop(2), struct misc_meta_data
 204  */
 205 void mmd_lock(void)
 206 {
 207         mutex_lock(mmd_mutex);
 208 }
 209
 210 /**
 211  * unlock the shared memory area containing the mmd struct
 212  *
 213  * \sa semop(2), struct misc_meta_data
 214  */
 215
 216 void mmd_unlock(void)
 217 {
 218         mutex_unlock(mmd_mutex);
 219 }
 220
 221 static void parse_config(int override)
 222 {
 223         char *home = para_homedir();
 224         struct stat statbuf;
 225         int ret;
 226         char *cf;
 227
 228         if (conf.config_file_given)
 229                 cf = conf.config_file_arg;
 230         else
 231                 cf = make_message("%s/.paraslash/server.conf", home);
 232         free(user_list);
 233         if (!conf.user_list_given)
 234                 user_list = make_message("%s/.paraslash/server.users", home);
 235         else
 236                 user_list = para_strdup(conf.user_list_arg);
 237         ret = stat(cf, &statbuf);
 238         if (ret && conf.config_file_given) {
 239                 ret = -1;
 240                 PARA_EMERG_LOG("can not stat config file %s\n", cf);
 241                 goto out;
 242         }
 243         if (!ret) {
 244                 int tmp = conf.daemon_given;
 245                 cmdline_parser_configfile(cf, &conf, override, 0, 0);
 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);
 263         user_list = 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 //      fcntl(signal_pipe, F_SETFL, O_NONBLOCK);
 273         PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
 274         ret += para_install_sighandler(SIGINT);
 275         ret += para_install_sighandler(SIGTERM);
 276         ret += para_install_sighandler(SIGHUP);
 277         ret += para_install_sighandler(SIGCHLD);
 278         ret += para_install_sighandler(SIGUSR1);
 279         signal(SIGPIPE, SIG_IGN);
 280         if (ret != 5) {
 281                 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
 282                 exit(EXIT_FAILURE);
 283         }
 284 }
 285
 286 static void init_selector(void)
 287 {
 288         int i, ret;
 289
 290         mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
 291         if (!conf.selector_given)
 292                 goto random;
 293         for (i = 0; selectors[i].name; i++) {
 294                 if (strcmp(selectors[i].name, conf.selector_arg))
 295                         continue;
 296                 PARA_NOTICE_LOG("initializing %s audio file selector\n",
 297                         selectors[i].name);
 298                 ret = selectors[i].init(&selectors[i]);
 299                 if (ret < 0) {
 300                         PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
 301                         break;
 302                 }
 303                 mmd->selector_num = i;
 304                 return;
 305         }
 306         PARA_WARNING_LOG("%s", "falling back to the random selector\n");
 307 random:
 308         mmd->selector_num = 0;
 309         selectors[0].init(&selectors[0]); /* always successful */
 310 }
 311
 312 static unsigned init_network(void)
 313 {
 314         int sockfd = init_tcp_socket(conf.port_arg);
 315
 316         if (sockfd < 0)
 317                 exit(EXIT_FAILURE);
 318         return sockfd;
 319 }
 320
 321 static void init_random_seed(void)
 322 {
 323         int fd, ret = -1, len = sizeof(unsigned int);
 324         unsigned int seed;
 325
 326         fd = open("/dev/urandom", O_RDONLY);
 327         if (fd < 0)
 328                 goto out;
 329         ret = -2;
 330         if (read(fd, &seed, len) != len)
 331                 goto out;
 332         srandom(seed);
 333         ret = 1;
 334 out:
 335         if (fd >= 0)
 336                 close(fd);
 337         if (ret > 0)
 338                 return;
 339         PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
 340                 ret);
 341         exit(EXIT_FAILURE);
 342 }
 343
 344 static unsigned do_inits(int argc, char **argv)
 345 {
 346         /* connector's address information */
 347         int sockfd;
 348
 349         init_random_seed();
 350         /* parse command line options */
 351         cmdline_parser(argc, argv, &conf);
 352         para_drop_privileges(conf.user_arg);
 353         /* parse config file, open log and set defaults */
 354         parse_config(0);
 355         log_welcome("para_server", conf.loglevel_arg);
 356         shm_init(); /* init mmd struct */
 357         server_uptime(UPTIME_SET); /* reset server uptime */
 358         /* become daemon */
 359         if (conf.daemon_given)
 360                 daemon_init();
 361         init_selector();
 362         PARA_NOTICE_LOG("%s", "initializing audio file sender\n");
 363         /* audio file sender */
 364         afs_init();
 365         mmd->server_pid = getpid();
 366         setup_signal_handling();
 367         mmd_lock();
 368         /* init network socket */
 369         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 370         sockfd = init_network();
 371         if (conf.autoplay_given) {
 372                 mmd->afs_status_flags |= AFS_PLAYING;
 373                 mmd->new_afs_status_flags |= AFS_PLAYING;
 374         }
 375         PARA_NOTICE_LOG("%s", "init complete\n");
 376         return sockfd;
 377 }
 378
 379 static void change_selector(void)
 380 {
 381         int ret, old = mmd->selector_num, new = mmd->selector_change;
 382
 383         selectors[old].shutdown();
 384         ret = selectors[new].init(&selectors[new]);
 385         mmd->selector_change = -1; /* reset */
 386         if (ret >= 0) {
 387                 mmd->selector_num = new;
 388                 return;
 389         }
 390         /* init failed */
 391         PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
 392         selectors[0].init(&selectors[0]);
 393         mmd->selector_num = 0;
 394 }
 395
 396 /*
 397  * called when server gets SIGHUP or when client invokes hup command.
 398  */
 399 static void handle_sighup(void)
 400 {
 401         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 402         close_log(logfile); /* gets reopened if necessary by parse_config */
 403         logfile = NULL;
 404         parse_config(1); /* reopens log */
 405         mmd->selector_change = mmd->selector_num; /* do not change selector.. */
 406         change_selector(); /* .. just reload */
 407 }
 408
 409 static void status_refresh(void)
 410 {
 411         static int prev_uptime = -1, prev_events = -1;
 412         int uptime = server_uptime(UPTIME_GET), ret = 1;
 413
 414         if (prev_events != mmd->events)
 415                 goto out;
 416         if (mmd->new_afs_status_flags != mmd->afs_status_flags)
 417                 goto out;
 418         if (uptime / 60 != prev_uptime / 60)
 419                 goto out;
 420         ret = 0;
 421 out:
 422         prev_uptime = uptime;
 423         prev_events = mmd->events;
 424         mmd->afs_status_flags = mmd->new_afs_status_flags;
 425         if (ret) {
 426                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 427                         mmd->events, mmd->audio_format);
 428                 killpg(0, SIGUSR1);
 429         }
 430 }
 431
 432 /*
 433  * MAIN
 434  */
 435 int main(int argc, char *argv[])
 436 {
 437         /* listen on sock_fd, new connection on new_fd */
 438         int sockfd, new_fd;
 439         struct sockaddr_in their_addr;
 440         int i, max_fileno, ret;
 441         pid_t chld_pid;
 442         fd_set rfds, wfds;
 443         struct timeval *timeout;
 444
 445         valid_fd_012();
 446         sockfd = do_inits(argc, argv);
 447 repeat:
 448         /* check socket and signal pipe in any case */
 449         FD_ZERO(&rfds);
 450         FD_ZERO(&wfds);
 451         FD_SET(sockfd, &rfds);
 452         max_fileno = sockfd;
 453         FD_SET(signal_pipe, &rfds);
 454         max_fileno = MAX(max_fileno, signal_pipe);
 455
 456         timeout = afs_preselect();
 457         status_refresh();
 458         for (i = 0; senders[i].name; i++) {
 459                 if (senders[i].status != SENDER_ON)
 460                         continue;
 461                 if (!senders[i].pre_select)
 462                         continue;
 463                 senders[i].pre_select(mmd->audio_format >= 0?
 464                         &afl[mmd->audio_format] : NULL,
 465                         &max_fileno,
 466                         &rfds, &wfds);
 467         }
 468         if (selectors[mmd->selector_num].pre_select) {
 469                 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
 470                 max_fileno = MAX(max_fileno, ret);
 471         }
 472         mmd_unlock();
 473         ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
 474         mmd_lock();
 475         if (mmd->selector_change >= 0)
 476                 change_selector();
 477         if (selectors[mmd->selector_num].post_select)
 478                 selectors[mmd->selector_num].post_select(&rfds, &wfds);
 479         if (ret < 0)
 480                 goto repeat;
 481         for (i = 0; senders[i].name; i++) {
 482                 if (senders[i].status != SENDER_ON)
 483                         continue;
 484                 if (!senders[i].post_select)
 485                         continue;
 486                 senders[i].post_select(mmd->audio_format >= 0?
 487                         &afl[mmd->audio_format] : NULL,
 488                         &rfds, &wfds);
 489         }
 490         if (!ret) {
 491                 afs_send_chunk();
 492                 status_refresh();
 493         }
 494         if (FD_ISSET(signal_pipe, &rfds)) {
 495                 int sig;
 496                 sig = para_next_signal();
 497                 switch (sig) {
 498                 case SIGHUP:
 499                         handle_sighup();
 500                         break;
 501                 case SIGCHLD:
 502                         para_reap_children();
 503                         break;
 504                 /* die on sigint/sigterm. Kill all children too. */
 505                 case SIGINT:
 506                 case SIGTERM:
 507                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 508                         kill(0, SIGTERM);
 509                         selectors[mmd->selector_num].shutdown();
 510                         mutex_destroy(mmd_mutex);
 511                         shm_detach(mmd);
 512                         shm_destroy(mmd_shm_id);
 513                         exit(EXIT_FAILURE);
 514                 }
 515         }
 516         if (mmd->sender_cmd_data.cmd_num >= 0) {
 517                 int num = mmd->sender_cmd_data.cmd_num,
 518                         s = mmd->sender_cmd_data.sender_num;
 519
 520                 if (senders[s].client_cmds[num])
 521                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 522                 mmd->sender_cmd_data.cmd_num = -1;
 523         }
 524         if (!FD_ISSET(sockfd, &rfds))
 525                 goto repeat;
 526
 527         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 528         if (new_fd < 0)
 529                 goto repeat;
 530         PARA_INFO_LOG("got connection from %s, forking\n",
 531                 inet_ntoa(their_addr.sin_addr));
 532         mmd->num_connects++;
 533         mmd->active_connections++;
 534         random();
 535         chld_pid = fork();
 536         if (chld_pid < 0) {
 537                 PARA_CRIT_LOG("%s", "fork failed\n");
 538                 goto repeat;
 539         }
 540         if (chld_pid) {
 541                 close(new_fd);
 542                 /* parent keeps accepting connections */
 543                 goto repeat;
 544         }
 545         alarm(ALARM_TIMEOUT);
 546         close_listed_fds();
 547         close(sockfd); /* child doesn't need the listener */
 548         /*
 549          * put info on who we are serving into argv[0] to make
 550          * client ip visible in top/ps
 551          */
 552         for (i = argc - 1; i >= 0; i--)
 553                 memset(argv[i], 0, strlen(argv[i]));
 554         sprintf(argv[0], "para_server (serving %s)",
 555                 inet_ntoa(their_addr.sin_addr));
 556         return handle_connect(new_fd, &their_addr);
 557 }