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 #include "signal.h"
  46 #include "user_list.h"
  47
  48 /** define the array of error lists needed by para_server */
  49 INIT_SERVER_ERRLISTS;
  50
  51 /** shut down non-authorized connections after that many seconds */
  52 #define ALARM_TIMEOUT 10
  53
  54 /* these are exported to afs.c. command.c and to all selectors */
  55 struct misc_meta_data *mmd;
  56 /** the configuration of para_server
  57  *
  58  * It also contains the options for all audio file selectors and all supported
  59  * senders.
  60 */
  61 struct server_args_info conf;
  62 char *user_list_file = NULL;
  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->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_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                 server_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_file);
 257         user_list_file = 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         PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
 267         ret += para_install_sighandler(SIGINT);
 268         ret += para_install_sighandler(SIGTERM);
 269         ret += para_install_sighandler(SIGHUP);
 270         ret += para_install_sighandler(SIGCHLD);
 271         ret += para_install_sighandler(SIGUSR1);
 272         signal(SIGPIPE, SIG_IGN);
 273         if (ret != 5) {
 274                 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
 275                 exit(EXIT_FAILURE);
 276         }
 277 }
 278
 279 static void init_selector(void)
 280 {
 281         int i, ret;
 282
 283         mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
 284         if (!conf.selector_given)
 285                 goto random;
 286         for (i = 0; selectors[i].name; i++) {
 287                 if (strcmp(selectors[i].name, conf.selector_arg))
 288                         continue;
 289                 PARA_NOTICE_LOG("initializing %s audio file selector\n",
 290                         selectors[i].name);
 291                 ret = selectors[i].init(&selectors[i]);
 292                 if (ret < 0) {
 293                         PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
 294                         break;
 295                 }
 296                 mmd->selector_num = i;
 297                 return;
 298         }
 299         PARA_WARNING_LOG("%s", "falling back to the random selector\n");
 300 random:
 301         mmd->selector_num = 0;
 302         selectors[0].init(&selectors[0]); /* always successful */
 303 }
 304
 305 static unsigned init_network(void)
 306 {
 307         int fd, ret = init_tcp_socket(conf.port_arg);
 308
 309         if (ret < 0)
 310                 goto err;
 311         fd = ret;
 312         ret = mark_fd_nonblock(fd);
 313         if (ret < 0)
 314                 goto err;
 315         return fd;
 316 err:
 317         PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
 318         exit(EXIT_FAILURE);
 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         server_cmdline_parser(argc, argv, &conf);
 352         para_drop_privileges(conf.user_arg, conf.group_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         init_user_list(user_list_file);
 359         /* become daemon */
 360         if (conf.daemon_given)
 361                 daemon_init();
 362         init_selector();
 363         PARA_NOTICE_LOG("%s", "initializing audio file sender\n");
 364         /* audio file sender */
 365         afs_init();
 366         mmd->server_pid = getpid();
 367         setup_signal_handling();
 368         mmd_lock();
 369         /* init network socket */
 370         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 371         sockfd = init_network();
 372         PARA_NOTICE_LOG("%s", "init complete\n");
 373         return sockfd;
 374 }
 375
 376 static void change_selector(void)
 377 {
 378         int ret, old = mmd->selector_num, new = mmd->selector_change;
 379
 380         selectors[old].shutdown();
 381         ret = selectors[new].init(&selectors[new]);
 382         mmd->selector_change = -1; /* reset */
 383         if (ret >= 0) {
 384                 mmd->selector_num = new;
 385                 return;
 386         }
 387         /* init failed */
 388         PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
 389         selectors[0].init(&selectors[0]);
 390         mmd->selector_num = 0;
 391 }
 392
 393 /*
 394  * called when server gets SIGHUP or when client invokes hup command.
 395  */
 396 static void handle_sighup(void)
 397 {
 398         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 399         close_log(logfile); /* gets reopened if necessary by parse_config */
 400         logfile = NULL;
 401         parse_config(1); /* reopens log */
 402         mmd->selector_change = mmd->selector_num; /* do not change selector.. */
 403         change_selector(); /* .. just reload */
 404         init_user_list(user_list_file); /* reload user list */
 405 }
 406
 407 static void status_refresh(void)
 408 {
 409         static int prev_uptime = -1, prev_events = -1;
 410         int uptime = server_uptime(UPTIME_GET), ret = 1;
 411
 412         if (prev_events != mmd->events)
 413                 goto out;
 414         if (mmd->new_afs_status_flags != mmd->afs_status_flags)
 415                 goto out;
 416         if (uptime / 60 != prev_uptime / 60)
 417                 goto out;
 418         ret = 0;
 419 out:
 420         prev_uptime = uptime;
 421         prev_events = mmd->events;
 422         mmd->afs_status_flags = mmd->new_afs_status_flags;
 423         if (ret) {
 424                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 425                         mmd->events, mmd->audio_format);
 426                 killpg(0, SIGUSR1);
 427         }
 428 }
 429
 430 /*
 431  * MAIN
 432  */
 433 int main(int argc, char *argv[])
 434 {
 435         /* listen on sock_fd, new connection on new_fd */
 436         int sockfd, new_fd;
 437         struct sockaddr_in their_addr;
 438         int i, max_fileno, ret;
 439         pid_t chld_pid;
 440         fd_set rfds, wfds;
 441         struct timeval *timeout;
 442
 443         valid_fd_012();
 444         sockfd = do_inits(argc, argv);
 445 repeat:
 446         FD_ZERO(&rfds);
 447         FD_ZERO(&wfds);
 448         max_fileno = -1;
 449         /* check socket and signal pipe in any case */
 450         para_fd_set(sockfd, &rfds, &max_fileno);
 451         para_fd_set(signal_pipe, &rfds, &max_fileno);
 452         timeout = afs_preselect();
 453         status_refresh();
 454         for (i = 0; senders[i].name; i++) {
 455                 if (senders[i].status != SENDER_ON)
 456                         continue;
 457                 if (!senders[i].pre_select)
 458                         continue;
 459                 senders[i].pre_select( &max_fileno, &rfds, &wfds);
 460         }
 461         if (selectors[mmd->selector_num].pre_select) {
 462                 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
 463                 max_fileno = PARA_MAX(max_fileno, ret);
 464         }
 465         mmd_unlock();
 466         ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
 467         mmd_lock();
 468         if (mmd->selector_change >= 0)
 469                 change_selector();
 470         if (selectors[mmd->selector_num].post_select)
 471                 selectors[mmd->selector_num].post_select(&rfds, &wfds);
 472         if (ret < 0)
 473                 goto repeat;
 474         for (i = 0; senders[i].name; i++) {
 475                 if (senders[i].status != SENDER_ON)
 476                         continue;
 477                 if (!senders[i].post_select)
 478                         continue;
 479                 senders[i].post_select(&rfds, &wfds);
 480         }
 481         afs_send_chunk();
 482         status_refresh();
 483         if (FD_ISSET(signal_pipe, &rfds)) {
 484                 int sig;
 485                 sig = para_next_signal();
 486                 switch (sig) {
 487                 case SIGHUP:
 488                         handle_sighup();
 489                         break;
 490                 case SIGCHLD:
 491                         para_reap_children();
 492                         break;
 493                 /* die on sigint/sigterm. Kill all children too. */
 494                 case SIGINT:
 495                 case SIGTERM:
 496                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 497                         kill(0, SIGTERM);
 498                         selectors[mmd->selector_num].shutdown();
 499                         mutex_destroy(mmd_mutex);
 500                         shm_detach(mmd);
 501                         shm_destroy(mmd_shm_id);
 502                         exit(EXIT_FAILURE);
 503                 }
 504         }
 505         if (mmd->sender_cmd_data.cmd_num >= 0) {
 506                 int num = mmd->sender_cmd_data.cmd_num,
 507                         s = mmd->sender_cmd_data.sender_num;
 508
 509                 if (senders[s].client_cmds[num])
 510                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 511                 mmd->sender_cmd_data.cmd_num = -1;
 512         }
 513         if (!FD_ISSET(sockfd, &rfds))
 514                 goto repeat;
 515
 516         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 517         if (new_fd < 0)
 518                 goto repeat;
 519         PARA_INFO_LOG("got connection from %s, forking\n",
 520                 inet_ntoa(their_addr.sin_addr));
 521         mmd->num_connects++;
 522         mmd->active_connections++;
 523         random();
 524         chld_pid = fork();
 525         if (chld_pid < 0) {
 526                 PARA_CRIT_LOG("%s", "fork failed\n");
 527                 goto repeat;
 528         }
 529         if (chld_pid) {
 530                 close(new_fd);
 531                 /* parent keeps accepting connections */
 532                 goto repeat;
 533         }
 534         alarm(ALARM_TIMEOUT);
 535         close_listed_fds();
 536         close(sockfd); /* child doesn't need the listener */
 537         /*
 538          * put info on who we are serving into argv[0] to make
 539          * client ip visible in top/ps
 540          */
 541         for (i = argc - 1; i >= 0; i--)
 542                 memset(argv[i], 0, strlen(argv[i]));
 543         sprintf(argv[0], "para_server (serving %s)",
 544                 inet_ntoa(their_addr.sin_addr));
 545         return handle_connect(new_fd, &their_addr);
 546 }