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 "user_list.h"
  46
  47 /** define the array of error lists needed by para_server */
  48 INIT_SERVER_ERRLISTS;
  49
  50 /** shut down non-authorized connections after that many seconds */
  51 #define ALARM_TIMEOUT 10
  52
  53 /* these are exported to afs.c. command.c and to all selectors */
  54 struct misc_meta_data *mmd;
  55 /** the configuration of para_server
  56  *
  57  * It also contains the options for all audio file selectors and all supported
  58  * senders.
  59 */
  60 struct server_args_info conf;
  61 char *user_list_file = NULL;
  62 extern void dccp_send_init(struct sender *);
  63 extern void http_send_init(struct sender *);
  64 extern void ortp_send_init(struct sender *);
  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_file);
 226         if (!conf.user_list_given)
 227                 user_list_file = make_message("%s/.paraslash/server.users", home);
 228         else
 229                 user_list_file = 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                 server_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_file);
 256         user_list_file = 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 fd, ret = init_tcp_socket(conf.port_arg);
 307
 308         if (ret < 0)
 309                 goto err;
 310         fd = ret;
 311         ret = mark_fd_nonblock(fd);
 312         if (ret < 0)
 313                 goto err;
 314         return fd;
 315 err:
 316         PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
 317         exit(EXIT_FAILURE);
 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         server_cmdline_parser(argc, argv, &conf);
 351         para_drop_privileges(conf.user_arg, conf.group_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         init_user_list(user_list_file);
 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         PARA_NOTICE_LOG("%s", "init complete\n");
 372         return sockfd;
 373 }
 374
 375 static void change_selector(void)
 376 {
 377         int ret, old = mmd->selector_num, new = mmd->selector_change;
 378
 379         selectors[old].shutdown();
 380         ret = selectors[new].init(&selectors[new]);
 381         mmd->selector_change = -1; /* reset */
 382         if (ret >= 0) {
 383                 mmd->selector_num = new;
 384                 return;
 385         }
 386         /* init failed */
 387         PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
 388         selectors[0].init(&selectors[0]);
 389         mmd->selector_num = 0;
 390 }
 391
 392 /*
 393  * called when server gets SIGHUP or when client invokes hup command.
 394  */
 395 static void handle_sighup(void)
 396 {
 397         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 398         close_log(logfile); /* gets reopened if necessary by parse_config */
 399         logfile = NULL;
 400         parse_config(1); /* reopens log */
 401         mmd->selector_change = mmd->selector_num; /* do not change selector.. */
 402         change_selector(); /* .. just reload */
 403 }
 404
 405 static void status_refresh(void)
 406 {
 407         static int prev_uptime = -1, prev_events = -1;
 408         int uptime = server_uptime(UPTIME_GET), ret = 1;
 409
 410         if (prev_events != mmd->events)
 411                 goto out;
 412         if (mmd->new_afs_status_flags != mmd->afs_status_flags)
 413                 goto out;
 414         if (uptime / 60 != prev_uptime / 60)
 415                 goto out;
 416         ret = 0;
 417 out:
 418         prev_uptime = uptime;
 419         prev_events = mmd->events;
 420         mmd->afs_status_flags = mmd->new_afs_status_flags;
 421         if (ret) {
 422                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 423                         mmd->events, mmd->audio_format);
 424                 killpg(0, SIGUSR1);
 425         }
 426 }
 427
 428 /*
 429  * MAIN
 430  */
 431 int main(int argc, char *argv[])
 432 {
 433         /* listen on sock_fd, new connection on new_fd */
 434         int sockfd, new_fd;
 435         struct sockaddr_in their_addr;
 436         int i, max_fileno, ret;
 437         pid_t chld_pid;
 438         fd_set rfds, wfds;
 439         struct timeval *timeout;
 440
 441         valid_fd_012();
 442         sockfd = do_inits(argc, argv);
 443 repeat:
 444         FD_ZERO(&rfds);
 445         FD_ZERO(&wfds);
 446         max_fileno = -1;
 447         /* check socket and signal pipe in any case */
 448         para_fd_set(sockfd, &rfds, &max_fileno);
 449         para_fd_set(signal_pipe, &rfds, &max_fileno);
 450         timeout = afs_preselect();
 451         status_refresh();
 452         for (i = 0; senders[i].name; i++) {
 453                 if (senders[i].status != SENDER_ON)
 454                         continue;
 455                 if (!senders[i].pre_select)
 456                         continue;
 457                 senders[i].pre_select( &max_fileno, &rfds, &wfds);
 458         }
 459         if (selectors[mmd->selector_num].pre_select) {
 460                 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
 461                 max_fileno = PARA_MAX(max_fileno, ret);
 462         }
 463         mmd_unlock();
 464         ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
 465         mmd_lock();
 466         if (mmd->selector_change >= 0)
 467                 change_selector();
 468         if (selectors[mmd->selector_num].post_select)
 469                 selectors[mmd->selector_num].post_select(&rfds, &wfds);
 470         if (ret < 0)
 471                 goto repeat;
 472         for (i = 0; senders[i].name; i++) {
 473                 if (senders[i].status != SENDER_ON)
 474                         continue;
 475                 if (!senders[i].post_select)
 476                         continue;
 477                 senders[i].post_select(&rfds, &wfds);
 478         }
 479         afs_send_chunk();
 480         status_refresh();
 481         if (FD_ISSET(signal_pipe, &rfds)) {
 482                 int sig;
 483                 sig = para_next_signal();
 484                 switch (sig) {
 485                 case SIGHUP:
 486                         handle_sighup();
 487                         break;
 488                 case SIGCHLD:
 489                         para_reap_children();
 490                         break;
 491                 /* die on sigint/sigterm. Kill all children too. */
 492                 case SIGINT:
 493                 case SIGTERM:
 494                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 495                         kill(0, SIGTERM);
 496                         selectors[mmd->selector_num].shutdown();
 497                         mutex_destroy(mmd_mutex);
 498                         shm_detach(mmd);
 499                         shm_destroy(mmd_shm_id);
 500                         exit(EXIT_FAILURE);
 501                 }
 502         }
 503         if (mmd->sender_cmd_data.cmd_num >= 0) {
 504                 int num = mmd->sender_cmd_data.cmd_num,
 505                         s = mmd->sender_cmd_data.sender_num;
 506
 507                 if (senders[s].client_cmds[num])
 508                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 509                 mmd->sender_cmd_data.cmd_num = -1;
 510         }
 511         if (!FD_ISSET(sockfd, &rfds))
 512                 goto repeat;
 513
 514         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 515         if (new_fd < 0)
 516                 goto repeat;
 517         PARA_INFO_LOG("got connection from %s, forking\n",
 518                 inet_ntoa(their_addr.sin_addr));
 519         mmd->num_connects++;
 520         mmd->active_connections++;
 521         random();
 522         chld_pid = fork();
 523         if (chld_pid < 0) {
 524                 PARA_CRIT_LOG("%s", "fork failed\n");
 525                 goto repeat;
 526         }
 527         if (chld_pid) {
 528                 close(new_fd);
 529                 /* parent keeps accepting connections */
 530                 goto repeat;
 531         }
 532         alarm(ALARM_TIMEOUT);
 533         close_listed_fds();
 534         close(sockfd); /* child doesn't need the listener */
 535         /*
 536          * put info on who we are serving into argv[0] to make
 537          * client ip visible in top/ps
 538          */
 539         for (i = argc - 1; i >= 0; i--)
 540                 memset(argv[i], 0, strlen(argv[i]));
 541         sprintf(argv[0], "para_server (serving %s)",
 542                 inet_ntoa(their_addr.sin_addr));
 543         return handle_connect(new_fd, &their_addr);
 544 }