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