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 dbtool, \ref sender,
  25  *  \ref receiver, \ref receiver_node, \ref filter, \ref filter_node.
  26  *
  27  */
  28
  29
  30
  31 #include "server.cmdline.h"
  32 #include "db.h"
  33 #include "server.h"
  34 #include "afs.h"
  35 #include "config.h"
  36 #include "close_on_fork.h"
  37 #include "send.h"
  38 #include "error.h"
  39 #include "net.h"
  40 #include "daemon.h"
  41 #include "string.h"
  42 #include "ipc.h"
  43
  44 /** define the array of error lists needed by para_server */
  45 INIT_SERVER_ERRLISTS;
  46
  47 /** shut down non-authorized connections after that many seconds */
  48 #define ALARM_TIMEOUT 10
  49
  50 /* these are exported to afs/command/dbtool */
  51 struct misc_meta_data *mmd;
  52 /** the configuration of para_server
  53  *
  54  * It also contains the options for all database tools and all supported
  55  * senders.
  56 */
  57 struct gengetopt_args_info conf;
  58 char *user_list = NULL;
  59 extern void http_send_init(struct sender *);
  60 extern void ortp_send_init(struct sender *);
  61 extern struct audio_format afl[];
  62
  63 /** the list of supported database tools */
  64 struct dbtool dblist[] = {
  65         {
  66                 .name = "random",
  67                 .init = random_dbtool_init,
  68                 .update_audio_file = NULL,
  69         },
  70         {
  71                 .name = "plm",
  72                 .init = plm_dbtool_init,
  73                 .update_audio_file = NULL,
  74                 .pre_select = NULL,
  75                 .post_select = NULL,
  76         },
  77 #ifdef HAVE_MYSQL
  78         {
  79                 .name = "mysql",
  80                 .init = mysql_dbtool_init,
  81                 .update_audio_file = NULL,
  82                 .pre_select = NULL,
  83                 .post_select = NULL,
  84         },
  85 #endif
  86         {
  87                 .name = NULL,
  88         }
  89 };
  90
  91 /** the list of supported senders */
  92 struct sender senders[] = {
  93         {
  94                 .name = "http",
  95                 .init = http_send_init,
  96         },
  97 #ifdef HAVE_ORTP
  98         {
  99                 .name = "ortp",
 100                 .init = ortp_send_init,
 101         },
 102 #endif
 103         {
 104                 .name = NULL,
 105         }
 106 };
 107
 108
 109 /* global variables for server-internal use */
 110 static FILE *logfile;
 111 static int mmd_mutex, mmd_shm_id;
 112 static int signal_pipe;
 113
 114 /**
 115  * para_server's log function
 116  *
 117  * \param ll the log level
 118  * \param fmt the format string describing the log message
 119  */
 120 void para_log(int ll, char* fmt,...)
 121 {
 122         va_list argp;
 123         FILE *outfd;
 124         struct tm *tm;
 125         time_t t1;
 126         char str[MAXLINE] = "";
 127         pid_t mypid;
 128
 129         if (ll < conf.loglevel_arg)
 130                 return;
 131         if (!logfile) {
 132                 if (ll < WARNING)
 133                         outfd = stdout;
 134                 else
 135                         outfd = stderr;
 136         } else
 137                 outfd = logfile;
 138         if (conf.daemon_given && !logfile)
 139                 return;
 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->dbt_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 //      fcntl(signal_pipe, F_SETFL, O_NONBLOCK);
 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_dbtool(void)
 280 {
 281         int i;
 282
 283         mmd->dbt_change = -1; /* no change nec., set to new dbt num by com_cdt */
 284         if (!dblist[1].name)
 285                 goto random;
 286         if (conf.dbtool_given) {
 287                 for (i = 0; dblist[i].name; i++) {
 288                         if (strcmp(dblist[i].name, conf.dbtool_arg))
 289                                 continue;
 290                         PARA_NOTICE_LOG("initializing %s database tool\n",
 291                                 dblist[i].name);
 292                         if (dblist[i].init(&dblist[i]) < 0) {
 293                                 PARA_WARNING_LOG("init %s failed",
 294                                         dblist[i].name);
 295                                 goto random;
 296                         }
 297                         mmd->dbt_num = i;
 298                         return;
 299                 }
 300                 PARA_WARNING_LOG("%s", "no such dbtool, switching to random\n");
 301                 goto random;
 302         }
 303         /* use the first dbtool that works
 304          * (assuming that random always works)
 305          */
 306         for (i = 1; dblist[i].name; i++) {
 307                 int ret = dblist[i].init(&dblist[i]);
 308                 if (ret >= 0) {
 309                         PARA_INFO_LOG("initialized %s\n", dblist[i].name);
 310                         mmd->dbt_num = i;
 311                         return;
 312                 }
 313                 PARA_CRIT_LOG("%s init failed: %s\n", dblist[i].name,
 314                         PARA_STRERROR(-ret));
 315         }
 316 random:
 317         mmd->dbt_num = 0;
 318         dblist[0].init(&dblist[0]); /* always successful */
 319 }
 320
 321 static unsigned init_network(void)
 322 {
 323         int sockfd = init_tcp_socket(conf.port_arg);
 324
 325         if (sockfd < 0)
 326                 exit(EXIT_FAILURE);
 327         return sockfd;
 328 }
 329
 330 static void init_random_seed(void)
 331 {
 332         int fd, ret = -1, len = sizeof(unsigned int);
 333         unsigned int seed;
 334
 335         fd = open("/dev/random", O_RDONLY);
 336         if (fd < 0)
 337                 goto out;
 338         ret = -2;
 339         if (read(fd, &seed, len) != len)
 340                 goto out;
 341         srandom(seed);
 342         ret = 1;
 343 out:
 344         if (fd >= 0)
 345                 close(fd);
 346         if (ret > 0)
 347                 return;
 348         PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
 349                 ret);
 350         exit(EXIT_FAILURE);
 351 }
 352
 353 static unsigned do_inits(int argc, char **argv)
 354 {
 355         /* connector's address information */
 356         int sockfd;
 357
 358         init_random_seed();
 359         /* parse command line options */
 360         cmdline_parser(argc, argv, &conf);
 361         para_drop_privileges(conf.user_arg);
 362         /* parse config file, open log and set defaults */
 363         parse_config(0);
 364         log_welcome("para_server", conf.loglevel_arg);
 365         shm_init(); /* init mmd struct */
 366         server_uptime(UPTIME_SET); /* reset server uptime */
 367         /* become daemon */
 368         if (conf.daemon_given)
 369                 daemon_init();
 370         init_dbtool();
 371         PARA_NOTICE_LOG("%s", "initializing audio file sender\n");
 372         /* audio file sender */
 373         afs_init();
 374         mmd->server_pid = getpid();
 375         setup_signal_handling();
 376         mmd_lock();
 377         /* init network socket */
 378         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 379         sockfd = init_network();
 380         if (conf.autoplay_given) {
 381                 mmd->afs_status_flags |= AFS_PLAYING;
 382                 mmd->new_afs_status_flags |= AFS_PLAYING;
 383         }
 384         PARA_NOTICE_LOG("%s", "init complete\n");
 385         return sockfd;
 386 }
 387
 388 static void handle_dbt_change(void)
 389 {
 390         int ret, old = mmd->dbt_num, new = mmd->dbt_change;
 391
 392         dblist[old].shutdown();
 393         ret = dblist[new].init(&dblist[new]);
 394         mmd->dbt_change = -1; /* reset */
 395         if (ret >= 0) {
 396                 mmd->dbt_num = new;
 397                 return;
 398         }
 399         /* init failed */
 400         PARA_ERROR_LOG("%s -- switching to the random dbtool\n", PARA_STRERROR(-ret));
 401         dblist[0].init(&dblist[0]);
 402         mmd->dbt_num = 0;
 403 }
 404
 405 /*
 406  * called when server gets SIGHUP or when client invokes hup command.
 407  */
 408 static void handle_sighup(void)
 409 {
 410         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 411         close_log(logfile); /* gets reopened if necessary by parse_config */
 412         logfile = NULL;
 413         parse_config(1); /* reopens log */
 414         mmd->dbt_change = mmd->dbt_num; /* do not change dbtool */
 415         handle_dbt_change(); /* force reloading dbtool */
 416 }
 417
 418 static void status_refresh(void)
 419 {
 420         static int prev_uptime = -1, prev_events = -1;
 421         int uptime = server_uptime(UPTIME_GET), ret = 1;
 422
 423         if (prev_events != mmd->events)
 424                 goto out;
 425         if (mmd->new_afs_status_flags != mmd->afs_status_flags)
 426                 goto out;
 427         if (uptime / 60 != prev_uptime / 60)
 428                 goto out;
 429         ret = 0;
 430 out:
 431         prev_uptime = uptime;
 432         prev_events = mmd->events;
 433         mmd->afs_status_flags = mmd->new_afs_status_flags;
 434         if (ret) {
 435                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 436                         mmd->events, mmd->audio_format);
 437                 killpg(0, SIGUSR1);
 438         }
 439 }
 440
 441 /*
 442  * MAIN
 443  */
 444 int main(int argc, char *argv[])
 445 {
 446         /* listen on sock_fd, new connection on new_fd */
 447         int sockfd, new_fd;
 448         struct sockaddr_in their_addr;
 449         int err, i, max_fileno, ret;
 450         pid_t chld_pid;
 451         fd_set rfds, wfds;
 452         struct timeval *timeout;
 453
 454         valid_fd_012();
 455         sockfd = do_inits(argc, argv);
 456 repeat:
 457         /* check socket and signal pipe in any case */
 458         FD_ZERO(&rfds);
 459         FD_ZERO(&wfds);
 460         FD_SET(sockfd, &rfds);
 461         max_fileno = sockfd;
 462         FD_SET(signal_pipe, &rfds);
 463         max_fileno = MAX(max_fileno, signal_pipe);
 464
 465         timeout = afs_preselect();
 466         status_refresh();
 467         for (i = 0; senders[i].name; i++) {
 468                 if (senders[i].status != SENDER_ON)
 469                         continue;
 470                 if (!senders[i].pre_select)
 471                         continue;
 472                 senders[i].pre_select(mmd->audio_format >= 0?
 473                         &afl[mmd->audio_format] : NULL,
 474                         &max_fileno,
 475                         &rfds, &wfds);
 476         }
 477         if (dblist[mmd->dbt_num].pre_select) {
 478                 ret = dblist[mmd->dbt_num].pre_select(&rfds, &wfds);
 479                 max_fileno = MAX(max_fileno, ret);
 480         }
 481         mmd_unlock();
 482 //      PARA_DEBUG_LOG("%s: select (max = %i)\n", __func__, max_fileno);
 483         ret = select(max_fileno + 1, &rfds, &wfds, NULL, timeout);
 484         err = errno;
 485         //PARA_DEBUG_LOG("%s: select returned  %i\n", __func__, ret);
 486         mmd_lock();
 487         if (mmd->dbt_change >= 0)
 488                 handle_dbt_change();
 489         if (dblist[mmd->dbt_num].post_select)
 490                 dblist[mmd->dbt_num].post_select(&rfds, &wfds);
 491         if (ret < 0 && err == EINTR)
 492                 goto repeat;
 493         if (ret < 0) {
 494                 PARA_CRIT_LOG("select error (%s)\n", strerror(err));
 495                 goto repeat;
 496         }
 497         for (i = 0; senders[i].name; i++) {
 498                 if (senders[i].status != SENDER_ON)
 499                         continue;
 500                 if (!senders[i].post_select)
 501                         continue;
 502                 senders[i].post_select(mmd->audio_format >= 0?
 503                         &afl[mmd->audio_format] : NULL,
 504                         &rfds, &wfds);
 505         }
 506         if (!ret) {
 507                 afs_send_chunk();
 508                 status_refresh();
 509         }
 510         if (FD_ISSET(signal_pipe, &rfds)) {
 511                 int sig;
 512                 sig = para_next_signal();
 513                 switch (sig) {
 514                 case SIGHUP:
 515                         handle_sighup();
 516                         break;
 517                 case SIGCHLD:
 518                         para_reap_children();
 519                         break;
 520                 /* die on sigint/sigterm. Kill all children too. */
 521                 case SIGINT:
 522                 case SIGTERM:
 523                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 524                         kill(0, SIGTERM);
 525                         dblist[mmd->dbt_num].shutdown();
 526                         mutex_destroy(mmd_mutex);
 527                         shm_detach(mmd);
 528                         shm_destroy(mmd_shm_id);
 529                         exit(EXIT_FAILURE);
 530                 }
 531         }
 532         if (mmd->sender_cmd_data.cmd_num >= 0) {
 533                 int num = mmd->sender_cmd_data.cmd_num,
 534                         s = mmd->sender_cmd_data.sender_num;
 535
 536                 if (senders[s].client_cmds[num])
 537                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 538                 mmd->sender_cmd_data.cmd_num = -1;
 539         }
 540         if (!FD_ISSET(sockfd, &rfds))
 541                 goto repeat;
 542
 543         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 544         if (new_fd < 0)
 545                 goto repeat;
 546         PARA_INFO_LOG("got connection from %s, forking\n",
 547                 inet_ntoa(their_addr.sin_addr));
 548         mmd->num_connects++;
 549         mmd->active_connections++;
 550         random();
 551         chld_pid = fork();
 552         if (chld_pid < 0) {
 553                 PARA_CRIT_LOG("%s", "fork failed\n");
 554                 goto repeat;
 555         }
 556         if (chld_pid) {
 557                 close(new_fd);
 558                 /* parent keeps accepting connections */
 559                 goto repeat;
 560         }
 561         alarm(ALARM_TIMEOUT);
 562         close_listed_fds();
 563         close(sockfd); /* child doesn't need the listener */
 564         /*
 565          * put info on who we are serving into argv[0] to make
 566          * client ip visible in top/ps
 567          */
 568         for (i = argc - 1; i >= 0; i--)
 569                 memset(argv[i], 0, strlen(argv[i]));
 570         sprintf(argv[0], "para_server (serving %s)",
 571                 inet_ntoa(their_addr.sin_addr));
 572         return handle_connect(new_fd, &their_addr);
 573 }