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 dccp_send_init(struct sender *);
  61 extern void http_send_init(struct sender *);
  62 extern void ortp_send_init(struct sender *);
  63 extern struct audio_format afl[];
  64
  65 /** the list of supported audio file selectors */
  66 struct audio_file_selector dblist[] = {
  67         {
  68                 .name = "random",
  69                 .init = random_selector_init,
  70                 .update_audio_file = NULL,
  71         },
  72         {
  73                 .name = "playlist",
  74                 .init = playlist_selector_init,
  75                 .update_audio_file = NULL,
  76                 .pre_select = NULL,
  77                 .post_select = NULL,
  78         },
  79 #ifdef HAVE_MYSQL
  80         {
  81                 .name = "mysql",
  82                 .init = mysql_selector_init,
  83                 .update_audio_file = NULL,
  84                 .pre_select = NULL,
  85                 .post_select = NULL,
  86         },
  87 #endif
  88         {
  89                 .name = NULL,
  90         }
  91 };
  92
  93 /** the list of supported senders */
  94 struct sender senders[] = {
  95         {
  96                 .name = "http",
  97                 .init = http_send_init,
  98         },
  99         {
 100                 .name = "dccp",
 101                 .init = dccp_send_init,
 102         },
 103 #ifdef HAVE_ORTP
 104         {
 105                 .name = "ortp",
 106                 .init = ortp_send_init,
 107         },
 108 #endif
 109         {
 110                 .name = NULL,
 111         }
 112 };
 113
 114
 115 /* global variables for server-internal use */
 116 static FILE *logfile;
 117 static int mmd_mutex, mmd_shm_id;
 118 static int signal_pipe;
 119
 120 /**
 121  * para_server's log function
 122  *
 123  * \param ll the log level
 124  * \param fmt the format string describing the log message
 125  */
 126 void para_log(int ll, char* fmt,...)
 127 {
 128         va_list argp;
 129         FILE *outfd;
 130         struct tm *tm;
 131         time_t t1;
 132         char str[MAXLINE] = "";
 133         pid_t mypid;
 134
 135         if (ll < conf.loglevel_arg)
 136                 return;
 137         if (!logfile) {
 138                 if (ll < WARNING)
 139                         outfd = stdout;
 140                 else
 141                         outfd = stderr;
 142         } else
 143                 outfd = logfile;
 144         if (conf.daemon_given && !logfile)
 145                 return;
 146         time(&t1);
 147         tm = localtime(&t1);
 148         strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
 149         fprintf(outfd, "%s ", str);
 150         if (conf.loglevel_arg <= INFO)
 151                 fprintf(outfd, "%i: ", ll);
 152         mypid = getpid();
 153         if (conf.loglevel_arg <= INFO)
 154                 fprintf(outfd, "(%d) ", mypid);
 155         va_start(argp, fmt);
 156         vfprintf(outfd, fmt, argp);
 157         va_end(argp);
 158 }
 159
 160 /*
 161  * setup shared memory area and get mutex for locking
 162  */
 163 static void shm_init(void)
 164 {
 165         void *shm;
 166         int ret = shm_new(sizeof(struct misc_meta_data));
 167
 168         if (ret < 0)
 169                 goto err_out;
 170
 171         ret = shm_attach(ret, ATTACH_RW, &shm);
 172         if (ret < 0)
 173                 goto err_out;
 174         mmd = shm;
 175         mmd_shm_id = ret;
 176
 177         ret = mutex_new();
 178         if (ret < 0)
 179                 goto err_out;
 180         mmd_mutex = ret;
 181
 182         mmd->selector_num = 0;
 183         mmd->num_played = 0;
 184         mmd->num_commands = 0;
 185         mmd->events = 0;
 186         mmd->num_connects = 0;
 187         mmd->active_connections = 0;
 188         strcpy(mmd->filename, "(none)");
 189         mmd->audio_format = -1;
 190         mmd->afs_status_flags = AFS_NEXT;
 191         mmd->new_afs_status_flags = AFS_NEXT;
 192         mmd->sender_cmd_data.cmd_num = -1;
 193         return;
 194 err_out:
 195         PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
 196         exit(EXIT_FAILURE);
 197 }
 198
 199 /**
 200  * lock the shared memory area containing the mmd struct
 201  *
 202  * \sa semop(2), struct misc_meta_data
 203  */
 204 void mmd_lock(void)
 205 {
 206         mutex_lock(mmd_mutex);
 207 }
 208
 209 /**
 210  * unlock the shared memory area containing the mmd struct
 211  *
 212  * \sa semop(2), struct misc_meta_data
 213  */
 214
 215 void mmd_unlock(void)
 216 {
 217         mutex_unlock(mmd_mutex);
 218 }
 219
 220 static void parse_config(int override)
 221 {
 222         char *home = para_homedir();
 223         struct stat statbuf;
 224         int ret;
 225         char *cf;
 226
 227         if (conf.config_file_given)
 228                 cf = conf.config_file_arg;
 229         else
 230                 cf = make_message("%s/.paraslash/server.conf", home);
 231         free(user_list);
 232         if (!conf.user_list_given)
 233                 user_list = make_message("%s/.paraslash/server.users", home);
 234         else
 235                 user_list = para_strdup(conf.user_list_arg);
 236         ret = stat(cf, &statbuf);
 237         if (ret && conf.config_file_given) {
 238                 ret = -1;
 239                 PARA_EMERG_LOG("can not stat config file %s\n", cf);
 240                 goto out;
 241         }
 242         if (!ret) {
 243                 int tmp = conf.daemon_given;
 244                 cmdline_parser_configfile(cf, &conf, override, 0, 0);
 245                 conf.daemon_given = tmp;
 246         }
 247         /* logfile */
 248         if (!conf.logfile_given && conf.daemon_given) {
 249                 ret = -1;
 250                 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
 251                 goto out;
 252         }
 253         if (conf.logfile_given)
 254                 logfile = open_log(conf.logfile_arg);
 255         ret = 1;
 256 out:
 257         free(cf);
 258         free(home);
 259         if (ret > 0)
 260                 return;
 261         free(user_list);
 262         user_list = NULL;
 263         exit(EXIT_FAILURE);
 264 }
 265
 266 static void setup_signal_handling(void)
 267 {
 268         int ret = 0;
 269
 270         signal_pipe = para_signal_init();
 271 //      fcntl(signal_pipe, F_SETFL, O_NONBLOCK);
 272         PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
 273         ret += para_install_sighandler(SIGINT);
 274         ret += para_install_sighandler(SIGTERM);
 275         ret += para_install_sighandler(SIGHUP);
 276         ret += para_install_sighandler(SIGCHLD);
 277         ret += para_install_sighandler(SIGUSR1);
 278         signal(SIGPIPE, SIG_IGN);
 279         if (ret != 5) {
 280                 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
 281                 exit(EXIT_FAILURE);
 282         }
 283 }
 284
 285 static void init_selector(void)
 286 {
 287         int i, ret;
 288
 289         mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
 290         if (!conf.selector_given)
 291                 goto random;
 292         for (i = 0; dblist[i].name; i++) {
 293                 if (strcmp(dblist[i].name, conf.selector_arg))
 294                         continue;
 295                 PARA_NOTICE_LOG("initializing %s audio file selector\n",
 296                         dblist[i].name);
 297                 ret = dblist[i].init(&dblist[i]);
 298                 if (ret < 0) {
 299                         PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
 300                         break;
 301                 }
 302                 mmd->selector_num = i;
 303                 return;
 304         }
 305         PARA_WARNING_LOG("%s", "falling back to the random selector\n");
 306 random:
 307         mmd->selector_num = 0;
 308         dblist[0].init(&dblist[0]); /* always successful */
 309 }
 310
 311 static unsigned init_network(void)
 312 {
 313         int sockfd = init_tcp_socket(conf.port_arg);
 314
 315         if (sockfd < 0)
 316                 exit(EXIT_FAILURE);
 317         return sockfd;
 318 }
 319
 320 static void init_random_seed(void)
 321 {
 322         int fd, ret = -1, len = sizeof(unsigned int);
 323         unsigned int seed;
 324
 325         fd = open("/dev/urandom", O_RDONLY);
 326         if (fd < 0)
 327                 goto out;
 328         ret = -2;
 329         if (read(fd, &seed, len) != len)
 330                 goto out;
 331         srandom(seed);
 332         ret = 1;
 333 out:
 334         if (fd >= 0)
 335                 close(fd);
 336         if (ret > 0)
 337                 return;
 338         PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
 339                 ret);
 340         exit(EXIT_FAILURE);
 341 }
 342
 343 static unsigned do_inits(int argc, char **argv)
 344 {
 345         /* connector's address information */
 346         int sockfd;
 347
 348         init_random_seed();
 349         /* parse command line options */
 350         cmdline_parser(argc, argv, &conf);
 351         para_drop_privileges(conf.user_arg);
 352         /* parse config file, open log and set defaults */
 353         parse_config(0);
 354         log_welcome("para_server", conf.loglevel_arg);
 355         shm_init(); /* init mmd struct */
 356         server_uptime(UPTIME_SET); /* reset server uptime */
 357         /* become daemon */
 358         if (conf.daemon_given)
 359                 daemon_init();
 360         init_selector();
 361         PARA_NOTICE_LOG("%s", "initializing audio file sender\n");
 362         /* audio file sender */
 363         afs_init();
 364         mmd->server_pid = getpid();
 365         setup_signal_handling();
 366         mmd_lock();
 367         /* init network socket */
 368         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 369         sockfd = init_network();
 370         if (conf.autoplay_given) {
 371                 mmd->afs_status_flags |= AFS_PLAYING;
 372                 mmd->new_afs_status_flags |= AFS_PLAYING;
 373         }
 374         PARA_NOTICE_LOG("%s", "init complete\n");
 375         return sockfd;
 376 }
 377
 378 static void change_selector(void)
 379 {
 380         int ret, old = mmd->selector_num, new = mmd->selector_change;
 381
 382         dblist[old].shutdown();
 383         ret = dblist[new].init(&dblist[new]);
 384         mmd->selector_change = -1; /* reset */
 385         if (ret >= 0) {
 386                 mmd->selector_num = new;
 387                 return;
 388         }
 389         /* init failed */
 390         PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
 391         dblist[0].init(&dblist[0]);
 392         mmd->selector_num = 0;
 393 }
 394
 395 /*
 396  * called when server gets SIGHUP or when client invokes hup command.
 397  */
 398 static void handle_sighup(void)
 399 {
 400         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 401         close_log(logfile); /* gets reopened if necessary by parse_config */
 402         logfile = NULL;
 403         parse_config(1); /* reopens log */
 404         mmd->selector_change = mmd->selector_num; /* do not change selector.. */
 405         change_selector(); /* .. just reload */
 406 }
 407
 408 static void status_refresh(void)
 409 {
 410         static int prev_uptime = -1, prev_events = -1;
 411         int uptime = server_uptime(UPTIME_GET), ret = 1;
 412
 413         if (prev_events != mmd->events)
 414                 goto out;
 415         if (mmd->new_afs_status_flags != mmd->afs_status_flags)
 416                 goto out;
 417         if (uptime / 60 != prev_uptime / 60)
 418                 goto out;
 419         ret = 0;
 420 out:
 421         prev_uptime = uptime;
 422         prev_events = mmd->events;
 423         mmd->afs_status_flags = mmd->new_afs_status_flags;
 424         if (ret) {
 425                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 426                         mmd->events, mmd->audio_format);
 427                 killpg(0, SIGUSR1);
 428         }
 429 }
 430
 431 /*
 432  * MAIN
 433  */
 434 int main(int argc, char *argv[])
 435 {
 436         /* listen on sock_fd, new connection on new_fd */
 437         int sockfd, new_fd;
 438         struct sockaddr_in their_addr;
 439         int err, i, max_fileno, ret;
 440         pid_t chld_pid;
 441         fd_set rfds, wfds;
 442         struct timeval *timeout;
 443
 444         valid_fd_012();
 445         sockfd = do_inits(argc, argv);
 446 repeat:
 447         /* check socket and signal pipe in any case */
 448         FD_ZERO(&rfds);
 449         FD_ZERO(&wfds);
 450         FD_SET(sockfd, &rfds);
 451         max_fileno = sockfd;
 452         FD_SET(signal_pipe, &rfds);
 453         max_fileno = MAX(max_fileno, signal_pipe);
 454
 455         timeout = afs_preselect();
 456         status_refresh();
 457         for (i = 0; senders[i].name; i++) {
 458                 if (senders[i].status != SENDER_ON)
 459                         continue;
 460                 if (!senders[i].pre_select)
 461                         continue;
 462                 senders[i].pre_select(mmd->audio_format >= 0?
 463                         &afl[mmd->audio_format] : NULL,
 464                         &max_fileno,
 465                         &rfds, &wfds);
 466         }
 467         if (dblist[mmd->selector_num].pre_select) {
 468                 ret = dblist[mmd->selector_num].pre_select(&rfds, &wfds);
 469                 max_fileno = MAX(max_fileno, ret);
 470         }
 471         mmd_unlock();
 472 //      PARA_DEBUG_LOG("%s: select (max = %i)\n", __func__, max_fileno);
 473         ret = select(max_fileno + 1, &rfds, &wfds, NULL, timeout);
 474         err = errno;
 475         //PARA_DEBUG_LOG("%s: select returned  %i\n", __func__, ret);
 476         mmd_lock();
 477         if (mmd->selector_change >= 0)
 478                 change_selector();
 479         if (dblist[mmd->selector_num].post_select)
 480                 dblist[mmd->selector_num].post_select(&rfds, &wfds);
 481         if (ret < 0 && err == EINTR)
 482                 goto repeat;
 483         if (ret < 0) {
 484                 PARA_CRIT_LOG("select error (%s)\n", strerror(err));
 485                 goto repeat;
 486         }
 487         for (i = 0; senders[i].name; i++) {
 488                 if (senders[i].status != SENDER_ON)
 489                         continue;
 490                 if (!senders[i].post_select)
 491                         continue;
 492                 senders[i].post_select(mmd->audio_format >= 0?
 493                         &afl[mmd->audio_format] : NULL,
 494                         &rfds, &wfds);
 495         }
 496         if (!ret) {
 497                 afs_send_chunk();
 498                 status_refresh();
 499         }
 500         if (FD_ISSET(signal_pipe, &rfds)) {
 501                 int sig;
 502                 sig = para_next_signal();
 503                 switch (sig) {
 504                 case SIGHUP:
 505                         handle_sighup();
 506                         break;
 507                 case SIGCHLD:
 508                         para_reap_children();
 509                         break;
 510                 /* die on sigint/sigterm. Kill all children too. */
 511                 case SIGINT:
 512                 case SIGTERM:
 513                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 514                         kill(0, SIGTERM);
 515                         dblist[mmd->selector_num].shutdown();
 516                         mutex_destroy(mmd_mutex);
 517                         shm_detach(mmd);
 518                         shm_destroy(mmd_shm_id);
 519                         exit(EXIT_FAILURE);
 520                 }
 521         }
 522         if (mmd->sender_cmd_data.cmd_num >= 0) {
 523                 int num = mmd->sender_cmd_data.cmd_num,
 524                         s = mmd->sender_cmd_data.sender_num;
 525
 526                 if (senders[s].client_cmds[num])
 527                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 528                 mmd->sender_cmd_data.cmd_num = -1;
 529         }
 530         if (!FD_ISSET(sockfd, &rfds))
 531                 goto repeat;
 532
 533         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 534         if (new_fd < 0)
 535                 goto repeat;
 536         PARA_INFO_LOG("got connection from %s, forking\n",
 537                 inet_ntoa(their_addr.sin_addr));
 538         mmd->num_connects++;
 539         mmd->active_connections++;
 540         random();
 541         chld_pid = fork();
 542         if (chld_pid < 0) {
 543                 PARA_CRIT_LOG("%s", "fork failed\n");
 544                 goto repeat;
 545         }
 546         if (chld_pid) {
 547                 close(new_fd);
 548                 /* parent keeps accepting connections */
 549                 goto repeat;
 550         }
 551         alarm(ALARM_TIMEOUT);
 552         close_listed_fds();
 553         close(sockfd); /* child doesn't need the listener */
 554         /*
 555          * put info on who we are serving into argv[0] to make
 556          * client ip visible in top/ps
 557          */
 558         for (i = argc - 1; i >= 0; i--)
 559                 memset(argv[i], 0, strlen(argv[i]));
 560         sprintf(argv[0], "para_server (serving %s)",
 561                 inet_ntoa(their_addr.sin_addr));
 562         return handle_connect(new_fd, &their_addr);
 563 }