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 <sys/mman.h> /* MAP_SHARED, PROT_READ, PROT_WRITE */
  38 #include "send.h"
  39 #include "error.h"
  40 #include "net.h"
  41 #include "daemon.h"
  42 #include "string.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         },
  75 #ifdef HAVE_MYSQL
  76         {
  77                 .name = "mysql",
  78                 .init = mysql_dbtool_init,
  79                 .update_audio_file = NULL,
  80         },
  81 #endif
  82         {
  83                 .name = NULL,
  84         }
  85 };
  86
  87 /** the list of supported senders */
  88 struct sender senders[] = {
  89         {
  90                 .name = "http",
  91                 .init = http_send_init,
  92         },
  93 #ifdef HAVE_ORTP
  94         {
  95                 .name = "ortp",
  96                 .init = ortp_send_init,
  97         },
  98 #endif
  99         {
 100                 .name = NULL,
 101         }
 102 };
 103
 104
 105 /* global variables for server-internal use */
 106 static FILE *logfile;
 107 static int mmd_semid;
 108 static int signal_pipe;
 109
 110 /**
 111  * para_server's log function
 112  *
 113  * \param ll the log level
 114  * \param fmt the format string describing the log message
 115  */
 116 void para_log(int ll, char* fmt,...)
 117 {
 118         va_list argp;
 119         FILE *outfd;
 120         struct tm *tm;
 121         time_t t1;
 122         char str[MAXLINE] = "";
 123         pid_t mypid;
 124
 125         if (ll < conf.loglevel_arg)
 126                 return;
 127         if (!logfile) {
 128                 if (ll < WARNING)
 129                         outfd = stdout;
 130                 else
 131                         outfd = stderr;
 132         } else
 133                 outfd = logfile;
 134         if (conf.daemon_given && !logfile)
 135                 return;
 136         time(&t1);
 137         tm = localtime(&t1);
 138         strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
 139         fprintf(outfd, "%s ", str);
 140         if (conf.loglevel_arg <= INFO)
 141                 fprintf(outfd, "%i: ", ll);
 142         mypid = getpid();
 143         if (conf.loglevel_arg <= INFO)
 144                 fprintf(outfd, "(%d) ", mypid);
 145         va_start(argp, fmt);
 146         vfprintf(outfd, fmt, argp);
 147         va_end(argp);
 148 }
 149
 150
 151 /*
 152  * setup shared memory area and get semaphore for locking
 153  */
 154 static void shm_init(void)
 155 {
 156         int fd;
 157         caddr_t area;
 158
 159         if ((fd = open("/dev/zero", O_RDWR)) < 0) {
 160                 PARA_EMERG_LOG("%s", "failed to open /dev/zero\n");
 161                 exit(EXIT_FAILURE);
 162         }
 163         if ((area = mmap(0, sizeof(struct misc_meta_data),
 164                         PROT_READ | PROT_WRITE,
 165                         MAP_SHARED, fd, 0)) == (caddr_t) - 1) {
 166                 PARA_EMERG_LOG("%s", "mmap error\n");
 167                 exit(EXIT_FAILURE);
 168         }
 169         close(fd); /* we dont need /dev/zero anymore */
 170         mmd = (struct misc_meta_data *)area;
 171
 172         mmd->dbt_num = 0;
 173         mmd->num_played = 0;
 174         mmd->num_commands = 0;
 175         mmd->events = 0;
 176         mmd->num_connects = 0;
 177         mmd->active_connections = 0;
 178         strcpy(mmd->filename, "(none)");
 179         mmd->audio_format = -1;
 180         mmd->afs_status_flags = AFS_NEXT;
 181         mmd->new_afs_status_flags = AFS_NEXT;
 182         mmd->sender_cmd_data.cmd_num = -1;
 183
 184         mmd_semid = semget(42, 1, IPC_CREAT | 0666);
 185         if (mmd_semid == -1) {
 186                 PARA_EMERG_LOG("%s", "semget failed\n");
 187                 exit(EXIT_FAILURE);
 188         }
 189 }
 190
 191 static void do_semop(struct sembuf *sops, int num)
 192 {
 193         if (semop(mmd_semid, sops, num) >= 0)
 194                 return;
 195         PARA_WARNING_LOG("semop failed (%s), retrying\n", strerror(errno));
 196         while (semop(mmd_semid, sops, num) < 0)
 197                 ; /* nothing */
 198 }
 199
 200 /**
 201  * lock the shared memory area containing the mmd struct
 202  *
 203  * \sa semop(2), struct misc_meta_data
 204  */
 205 void mmd_lock(void)
 206 {
 207         struct sembuf sops[2] = {
 208                 {
 209                         .sem_num = 0,
 210                         .sem_op = 0,
 211                         .sem_flg = SEM_UNDO
 212                 },
 213                 {
 214                         .sem_num = 0,
 215                         .sem_op = 1,
 216                         .sem_flg = SEM_UNDO
 217                 }
 218         };
 219         do_semop(sops, 2);
 220 }
 221
 222 /**
 223  * unlock the shared memory area containing the mmd struct
 224  *
 225  * \sa semop(2), struct misc_meta_data
 226  */
 227 void mmd_unlock(void)
 228 {
 229         struct sembuf sops[1] = {
 230                 {
 231                         .sem_num = 0,
 232                         .sem_op = -1,
 233                         .sem_flg = SEM_UNDO
 234                 },
 235         };
 236         do_semop(sops, 1);
 237 }
 238
 239 static void parse_config(int override)
 240 {
 241         char *home = para_homedir();
 242         struct stat statbuf;
 243         int ret;
 244         char *cf;
 245
 246         if (conf.config_file_given)
 247                 cf = conf.config_file_arg;
 248         else
 249                 cf = make_message("%s/.paraslash/server.conf", home);
 250         free(user_list);
 251         if (!conf.user_list_given)
 252                 user_list = make_message("%s/.paraslash/server.users", home);
 253         else
 254                 user_list = para_strdup(conf.user_list_arg);
 255         ret = stat(cf, &statbuf);
 256         if (ret && conf.config_file_given) {
 257                 ret = -1;
 258                 PARA_EMERG_LOG("can not stat config file %s\n", cf);
 259                 goto out;
 260         }
 261         if (!ret) {
 262                 int tmp = conf.daemon_given;
 263                 cmdline_parser_configfile(cf, &conf, override, 0, 0);
 264                 conf.daemon_given = tmp;
 265         }
 266         /* logfile */
 267         if (!conf.logfile_given && conf.daemon_given) {
 268                 ret = -1;
 269                 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
 270                 goto out;
 271         }
 272         if (conf.logfile_given)
 273                 logfile = open_log(conf.logfile_arg);
 274         ret = 1;
 275 out:
 276         free(cf);
 277         free(home);
 278         if (ret > 0)
 279                 return;
 280         free(user_list);
 281         user_list = NULL;
 282         exit(EXIT_FAILURE);
 283 }
 284
 285 static void setup_signal_handling(void)
 286 {
 287         int ret = 0;
 288
 289         signal_pipe = para_signal_init();
 290 //      fcntl(signal_pipe, F_SETFL, O_NONBLOCK);
 291         PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
 292         ret += para_install_sighandler(SIGINT);
 293         ret += para_install_sighandler(SIGTERM);
 294         ret += para_install_sighandler(SIGHUP);
 295         ret += para_install_sighandler(SIGCHLD);
 296         signal(SIGPIPE, SIG_IGN);
 297         signal(SIGUSR1, SIG_IGN);
 298         if (ret != 4) {
 299                 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
 300                 exit(EXIT_FAILURE);
 301         }
 302 }
 303
 304 static void init_dbtool(void)
 305 {
 306         int i;
 307
 308         mmd->dbt_change = -1; /* no change nec., set to new dbt num by com_cdt */
 309         if (!dblist[1].name)
 310                 goto random;
 311         if (conf.dbtool_given) {
 312                 for (i = 0; dblist[i].name; i++) {
 313                         if (strcmp(dblist[i].name, conf.dbtool_arg))
 314                                 continue;
 315                         PARA_NOTICE_LOG("initializing %s database tool\n",
 316                                 dblist[i].name);
 317                         if (dblist[i].init(&dblist[i]) < 0) {
 318                                 PARA_WARNING_LOG("init %s failed",
 319                                         dblist[i].name);
 320                                 goto random;
 321                         }
 322                         mmd->dbt_num = i;
 323                         return;
 324                 }
 325                 PARA_WARNING_LOG("%s", "no such dbtool, switching to random\n");
 326                 goto random;
 327         }
 328         /* use the first dbtool that works
 329          * (assuming that random always works)
 330          */
 331         for (i = 1; dblist[i].name; i++) {
 332                 int ret = dblist[i].init(&dblist[i]);
 333                 if (ret >= 0) {
 334                         PARA_INFO_LOG("initialized %s\n", dblist[i].name);
 335                         mmd->dbt_num = i;
 336                         return;
 337                 }
 338                 PARA_CRIT_LOG("%s init failed: %s\n", dblist[i].name,
 339                         PARA_STRERROR(-ret));
 340         }
 341 random:
 342         mmd->dbt_num = 0;
 343         dblist[0].init(&dblist[0]); /* always successful */
 344 }
 345
 346 static unsigned init_network(void)
 347 {
 348         int sockfd = init_tcp_socket(conf.port_arg);
 349
 350         if (sockfd < 0)
 351                 exit(EXIT_FAILURE);
 352         return sockfd;
 353 }
 354
 355 static void init_random_seed(void)
 356 {
 357         int fd, ret = -1, len = sizeof(unsigned int);
 358         unsigned int seed;
 359
 360         fd = open("/dev/random", O_RDONLY);
 361         if (fd < 0)
 362                 goto out;
 363         ret = -2;
 364         if (read(fd, &seed, len) != len)
 365                 goto out;
 366         srandom(seed);
 367         ret = 1;
 368 out:
 369         if (fd >= 0)
 370                 close(fd);
 371         if (ret > 0)
 372                 return;
 373         PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
 374                 ret);
 375         exit(EXIT_FAILURE);
 376 }
 377
 378 static unsigned do_inits(int argc, char **argv)
 379 {
 380         /* connector's address information */
 381         int sockfd;
 382
 383         init_random_seed();
 384         /* parse command line options */
 385         cmdline_parser(argc, argv, &conf);
 386         para_drop_privileges(conf.user_arg);
 387         /* parse config file, open log and set defaults */
 388         parse_config(0);
 389         log_welcome("para_server", conf.loglevel_arg);
 390         shm_init(); /* init mmd struct */
 391         server_uptime(UPTIME_SET); /* reset server uptime */
 392         /* become daemon */
 393         if (conf.daemon_given)
 394                 daemon_init();
 395         init_dbtool();
 396         PARA_NOTICE_LOG("%s", "initializing audio file sender\n");
 397         /* audio file sender */
 398         afs_init();
 399         mmd->server_pid = getpid();
 400         setup_signal_handling();
 401         mmd_lock();
 402         /* init network socket */
 403         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 404         sockfd = init_network();
 405         if (conf.autoplay_given) {
 406                 mmd->afs_status_flags |= AFS_PLAYING;
 407                 mmd->new_afs_status_flags |= AFS_PLAYING;
 408         }
 409         PARA_NOTICE_LOG("%s", "init complete\n");
 410         return sockfd;
 411 }
 412
 413 static void handle_dbt_change(void)
 414 {
 415         int ret, old = mmd->dbt_num, new = mmd->dbt_change;
 416
 417         dblist[old].shutdown();
 418         ret = dblist[new].init(&dblist[new]);
 419         mmd->dbt_change = -1; /* reset */
 420         if (ret >= 0) {
 421                 mmd->dbt_num = new;
 422                 return;
 423         }
 424         /* init failed */
 425         PARA_ERROR_LOG("%s -- switching to the random dbtool\n", PARA_STRERROR(-ret));
 426         dblist[0].init(&dblist[0]);
 427         mmd->dbt_num = 0;
 428 }
 429
 430 /*
 431  * called when server gets SIGHUP or when client invokes hup command.
 432  */
 433 static void handle_sighup(void)
 434 {
 435         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 436         close_log(logfile); /* gets reopened if necessary by parse_config */
 437         logfile = NULL;
 438         parse_config(1); /* reopens log */
 439         mmd->dbt_change = mmd->dbt_num; /* do not change dbtool */
 440         handle_dbt_change(); /* force reloading dbtool */
 441 }
 442
 443 static void status_refresh(void)
 444 {
 445         static int prev_uptime = -1, prev_events = -1;
 446         int uptime = server_uptime(UPTIME_GET), ret = 1;
 447
 448         if (prev_events != mmd->events)
 449                 goto out;
 450         if (mmd->new_afs_status_flags != mmd->afs_status_flags)
 451                 goto out;
 452         if (uptime / 60 != prev_uptime / 60)
 453                 goto out;
 454         ret = 0;
 455 out:
 456         prev_uptime = uptime;
 457         prev_events = mmd->events;
 458         mmd->afs_status_flags = mmd->new_afs_status_flags;
 459         if (ret) {
 460                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 461                         mmd->events, mmd->audio_format);
 462                 killpg(0, SIGUSR1);
 463         }
 464 }
 465
 466 /*
 467  * MAIN
 468  */
 469 int main(int argc, char *argv[])
 470 {
 471         /* listen on sock_fd, new connection on new_fd */
 472         int sockfd, new_fd;
 473         struct sockaddr_in their_addr;
 474         int err, i, max_fileno, ret;
 475         pid_t chld_pid;
 476         fd_set rfds, wfds;
 477         struct timeval *timeout;
 478
 479         valid_fd_012();
 480         sockfd = do_inits(argc, argv);
 481 repeat:
 482         /* check socket and signal pipe in any case */
 483         FD_ZERO(&rfds);
 484         FD_ZERO(&wfds);
 485         FD_SET(sockfd, &rfds);
 486         max_fileno = sockfd;
 487         FD_SET(signal_pipe, &rfds);
 488         max_fileno = MAX(max_fileno, signal_pipe);
 489
 490         timeout = afs_preselect();
 491         status_refresh();
 492         for (i = 0; senders[i].name; i++) {
 493                 if (senders[i].status != SENDER_ON)
 494                         continue;
 495                 if (!senders[i].pre_select)
 496                         continue;
 497                 senders[i].pre_select(mmd->audio_format >= 0?
 498                         &afl[mmd->audio_format] : NULL,
 499                         &max_fileno,
 500                         &rfds, &wfds);
 501         }
 502         mmd_unlock();
 503 //      PARA_DEBUG_LOG("%s: select (max = %i)\n", __func__, max_fileno);
 504         ret = select(max_fileno + 1, &rfds, &wfds, NULL, timeout);
 505         err = errno;
 506         //PARA_DEBUG_LOG("%s: select returned  %i\n", __func__, ret);
 507         mmd_lock();
 508         if (mmd->dbt_change >= 0)
 509                 handle_dbt_change();
 510         if (ret < 0 && err == EINTR)
 511                 goto repeat;
 512         if (ret < 0) {
 513                 PARA_CRIT_LOG("select error (%s)\n", strerror(err));
 514                 goto repeat;
 515         }
 516         for (i = 0; senders[i].name; i++) {
 517                 if (senders[i].status != SENDER_ON)
 518                         continue;
 519                 if (!senders[i].post_select)
 520                         continue;
 521                 senders[i].post_select(mmd->audio_format >= 0?
 522                         &afl[mmd->audio_format] : NULL,
 523                         &rfds, &wfds);
 524         }
 525         if (!ret) {
 526                 afs_send_chunk();
 527                 status_refresh();
 528         }
 529         if (FD_ISSET(signal_pipe, &rfds)) {
 530                 int sig;
 531                 sig = para_next_signal();
 532                 switch (sig) {
 533                 case SIGHUP:
 534                         handle_sighup();
 535                         break;
 536                 case SIGCHLD:
 537                         para_reap_children();
 538                         break;
 539                 /* die on sigint/sigterm. Kill all children too. */
 540                 case SIGINT:
 541                 case SIGTERM:
 542                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 543                         kill(0, SIGTERM);
 544                         exit(EXIT_FAILURE);
 545                 }
 546         }
 547         if (mmd->sender_cmd_data.cmd_num >= 0) {
 548                 int num = mmd->sender_cmd_data.cmd_num,
 549                         s = mmd->sender_cmd_data.sender_num;
 550
 551                 if (senders[s].client_cmds[num])
 552                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 553                 mmd->sender_cmd_data.cmd_num = -1;
 554         }
 555         if (!FD_ISSET(sockfd, &rfds))
 556                 goto repeat;
 557
 558         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 559         if (new_fd < 0)
 560                 goto repeat;
 561         PARA_INFO_LOG("got connection from %s, forking\n",
 562                 inet_ntoa(their_addr.sin_addr));
 563         mmd->num_connects++;
 564         mmd->active_connections++;
 565         random();
 566         chld_pid = fork();
 567         if (chld_pid < 0) {
 568                 PARA_CRIT_LOG("%s", "fork failed\n");
 569                 goto repeat;
 570         }
 571         if (chld_pid) {
 572                 close(new_fd);
 573                 /* parent keeps accepting connections */
 574                 goto repeat;
 575         }
 576         alarm(ALARM_TIMEOUT);
 577         close_listed_fds();
 578         close(sockfd); /* child doesn't need the listener */
 579         /*
 580          * put info on who we are serving into argv[0] to make
 581          * client ip visible in top/ps
 582          */
 583         for (i = argc - 1; i >= 0; i--)
 584                 memset(argv[i], 0, strlen(argv[i]));
 585         sprintf(argv[0], "para_server (serving %s)",
 586                 inet_ntoa(their_addr.sin_addr));
 587         return handle_connect(new_fd, &their_addr);
 588 }