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                 .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_semid;
 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 /*
 156  * setup shared memory area and get semaphore for locking
 157  */
 158 static void shm_init(void)
 159 {
 160         int fd;
 161         caddr_t area;
 162
 163         if ((fd = open("/dev/zero", O_RDWR)) < 0) {
 164                 PARA_EMERG_LOG("%s", "failed to open /dev/zero\n");
 165                 exit(EXIT_FAILURE);
 166         }
 167         if ((area = mmap(0, sizeof(struct misc_meta_data),
 168                         PROT_READ | PROT_WRITE,
 169                         MAP_SHARED, fd, 0)) == (caddr_t) - 1) {
 170                 PARA_EMERG_LOG("%s", "mmap error\n");
 171                 exit(EXIT_FAILURE);
 172         }
 173         close(fd); /* we dont need /dev/zero anymore */
 174         mmd = (struct misc_meta_data *)area;
 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
 188         mmd_semid = semget(42, 1, IPC_CREAT | 0666);
 189         if (mmd_semid == -1) {
 190                 PARA_EMERG_LOG("%s", "semget failed\n");
 191                 exit(EXIT_FAILURE);
 192         }
 193 }
 194
 195 static void do_semop(struct sembuf *sops, int num)
 196 {
 197         if (semop(mmd_semid, sops, num) >= 0)
 198                 return;
 199         PARA_WARNING_LOG("semop failed (%s), retrying\n", strerror(errno));
 200         while (semop(mmd_semid, sops, num) < 0)
 201                 ; /* nothing */
 202 }
 203
 204 /**
 205  * lock the shared memory area containing the mmd struct
 206  *
 207  * \sa semop(2), struct misc_meta_data
 208  */
 209 void mmd_lock(void)
 210 {
 211         struct sembuf sops[2] = {
 212                 {
 213                         .sem_num = 0,
 214                         .sem_op = 0,
 215                         .sem_flg = SEM_UNDO
 216                 },
 217                 {
 218                         .sem_num = 0,
 219                         .sem_op = 1,
 220                         .sem_flg = SEM_UNDO
 221                 }
 222         };
 223         do_semop(sops, 2);
 224 }
 225
 226 /**
 227  * unlock the shared memory area containing the mmd struct
 228  *
 229  * \sa semop(2), struct misc_meta_data
 230  */
 231 void mmd_unlock(void)
 232 {
 233         struct sembuf sops[1] = {
 234                 {
 235                         .sem_num = 0,
 236                         .sem_op = -1,
 237                         .sem_flg = SEM_UNDO
 238                 },
 239         };
 240         do_semop(sops, 1);
 241 }
 242
 243 static void parse_config(int override)
 244 {
 245         char *home = para_homedir();
 246         struct stat statbuf;
 247         int ret;
 248         char *cf;
 249
 250         if (conf.config_file_given)
 251                 cf = conf.config_file_arg;
 252         else
 253                 cf = make_message("%s/.paraslash/server.conf", home);
 254         free(user_list);
 255         if (!conf.user_list_given)
 256                 user_list = make_message("%s/.paraslash/server.users", home);
 257         else
 258                 user_list = para_strdup(conf.user_list_arg);
 259         ret = stat(cf, &statbuf);
 260         if (ret && conf.config_file_given) {
 261                 ret = -1;
 262                 PARA_EMERG_LOG("can not stat config file %s\n", cf);
 263                 goto out;
 264         }
 265         if (!ret) {
 266                 int tmp = conf.daemon_given;
 267                 cmdline_parser_configfile(cf, &conf, override, 0, 0);
 268                 conf.daemon_given = tmp;
 269         }
 270         /* logfile */
 271         if (!conf.logfile_given && conf.daemon_given) {
 272                 ret = -1;
 273                 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
 274                 goto out;
 275         }
 276         if (conf.logfile_given)
 277                 logfile = open_log(conf.logfile_arg);
 278         ret = 1;
 279 out:
 280         free(cf);
 281         free(home);
 282         if (ret > 0)
 283                 return;
 284         free(user_list);
 285         user_list = NULL;
 286         exit(EXIT_FAILURE);
 287 }
 288
 289 static void setup_signal_handling(void)
 290 {
 291         int ret = 0;
 292
 293         signal_pipe = para_signal_init();
 294 //      fcntl(signal_pipe, F_SETFL, O_NONBLOCK);
 295         PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
 296         ret += para_install_sighandler(SIGINT);
 297         ret += para_install_sighandler(SIGTERM);
 298         ret += para_install_sighandler(SIGHUP);
 299         ret += para_install_sighandler(SIGCHLD);
 300         signal(SIGPIPE, SIG_IGN);
 301         signal(SIGUSR1, SIG_IGN);
 302         if (ret != 4) {
 303                 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
 304                 exit(EXIT_FAILURE);
 305         }
 306 }
 307
 308 static void init_dbtool(void)
 309 {
 310         int i;
 311
 312         mmd->dbt_change = -1; /* no change nec., set to new dbt num by com_cdt */
 313         if (!dblist[1].name)
 314                 goto random;
 315         if (conf.dbtool_given) {
 316                 for (i = 0; dblist[i].name; i++) {
 317                         if (strcmp(dblist[i].name, conf.dbtool_arg))
 318                                 continue;
 319                         PARA_NOTICE_LOG("initializing %s database tool\n",
 320                                 dblist[i].name);
 321                         if (dblist[i].init(&dblist[i]) < 0) {
 322                                 PARA_WARNING_LOG("init %s failed",
 323                                         dblist[i].name);
 324                                 goto random;
 325                         }
 326                         mmd->dbt_num = i;
 327                         return;
 328                 }
 329                 PARA_WARNING_LOG("%s", "no such dbtool, switching to random\n");
 330                 goto random;
 331         }
 332         /* use the first dbtool that works
 333          * (assuming that random always works)
 334          */
 335         for (i = 1; dblist[i].name; i++) {
 336                 int ret = dblist[i].init(&dblist[i]);
 337                 if (ret >= 0) {
 338                         PARA_INFO_LOG("initialized %s\n", dblist[i].name);
 339                         mmd->dbt_num = i;
 340                         return;
 341                 }
 342                 PARA_CRIT_LOG("%s init failed: %s\n", dblist[i].name,
 343                         PARA_STRERROR(-ret));
 344         }
 345 random:
 346         mmd->dbt_num = 0;
 347         dblist[0].init(&dblist[0]); /* always successful */
 348 }
 349
 350 static unsigned init_network(void)
 351 {
 352         int sockfd = init_tcp_socket(conf.port_arg);
 353
 354         if (sockfd < 0)
 355                 exit(EXIT_FAILURE);
 356         return sockfd;
 357 }
 358
 359 static void init_random_seed(void)
 360 {
 361         int fd, ret = -1, len = sizeof(unsigned int);
 362         unsigned int seed;
 363
 364         fd = open("/dev/random", O_RDONLY);
 365         if (fd < 0)
 366                 goto out;
 367         ret = -2;
 368         if (read(fd, &seed, len) != len)
 369                 goto out;
 370         srandom(seed);
 371         ret = 1;
 372 out:
 373         if (fd >= 0)
 374                 close(fd);
 375         if (ret > 0)
 376                 return;
 377         PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
 378                 ret);
 379         exit(EXIT_FAILURE);
 380 }
 381
 382 static unsigned do_inits(int argc, char **argv)
 383 {
 384         /* connector's address information */
 385         int sockfd;
 386
 387         init_random_seed();
 388         /* parse command line options */
 389         cmdline_parser(argc, argv, &conf);
 390         para_drop_privileges(conf.user_arg);
 391         /* parse config file, open log and set defaults */
 392         parse_config(0);
 393         log_welcome("para_server", conf.loglevel_arg);
 394         shm_init(); /* init mmd struct */
 395         server_uptime(UPTIME_SET); /* reset server uptime */
 396         /* become daemon */
 397         if (conf.daemon_given)
 398                 daemon_init();
 399         init_dbtool();
 400         PARA_NOTICE_LOG("%s", "initializing audio file sender\n");
 401         /* audio file sender */
 402         afs_init();
 403         mmd->server_pid = getpid();
 404         setup_signal_handling();
 405         mmd_lock();
 406         /* init network socket */
 407         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 408         sockfd = init_network();
 409         if (conf.autoplay_given) {
 410                 mmd->afs_status_flags |= AFS_PLAYING;
 411                 mmd->new_afs_status_flags |= AFS_PLAYING;
 412         }
 413         PARA_NOTICE_LOG("%s", "init complete\n");
 414         return sockfd;
 415 }
 416
 417 static void handle_dbt_change(void)
 418 {
 419         int ret, old = mmd->dbt_num, new = mmd->dbt_change;
 420
 421         dblist[old].shutdown();
 422         ret = dblist[new].init(&dblist[new]);
 423         mmd->dbt_change = -1; /* reset */
 424         if (ret >= 0) {
 425                 mmd->dbt_num = new;
 426                 return;
 427         }
 428         /* init failed */
 429         PARA_ERROR_LOG("%s -- switching to the random dbtool\n", PARA_STRERROR(-ret));
 430         dblist[0].init(&dblist[0]);
 431         mmd->dbt_num = 0;
 432 }
 433
 434 /*
 435  * called when server gets SIGHUP or when client invokes hup command.
 436  */
 437 static void handle_sighup(void)
 438 {
 439         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 440         close_log(logfile); /* gets reopened if necessary by parse_config */
 441         logfile = NULL;
 442         parse_config(1); /* reopens log */
 443         mmd->dbt_change = mmd->dbt_num; /* do not change dbtool */
 444         handle_dbt_change(); /* force reloading dbtool */
 445 }
 446
 447 static void status_refresh(void)
 448 {
 449         static int prev_uptime = -1, prev_events = -1;
 450         int uptime = server_uptime(UPTIME_GET), ret = 1;
 451
 452         if (prev_events != mmd->events)
 453                 goto out;
 454         if (mmd->new_afs_status_flags != mmd->afs_status_flags)
 455                 goto out;
 456         if (uptime / 60 != prev_uptime / 60)
 457                 goto out;
 458         ret = 0;
 459 out:
 460         prev_uptime = uptime;
 461         prev_events = mmd->events;
 462         mmd->afs_status_flags = mmd->new_afs_status_flags;
 463         if (ret) {
 464                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 465                         mmd->events, mmd->audio_format);
 466                 killpg(0, SIGUSR1);
 467         }
 468 }
 469
 470 /*
 471  * MAIN
 472  */
 473 int main(int argc, char *argv[])
 474 {
 475         /* listen on sock_fd, new connection on new_fd */
 476         int sockfd, new_fd;
 477         struct sockaddr_in their_addr;
 478         int err, i, max_fileno, ret;
 479         pid_t chld_pid;
 480         fd_set rfds, wfds;
 481         struct timeval *timeout;
 482
 483         valid_fd_012();
 484         sockfd = do_inits(argc, argv);
 485 repeat:
 486         /* check socket and signal pipe in any case */
 487         FD_ZERO(&rfds);
 488         FD_ZERO(&wfds);
 489         FD_SET(sockfd, &rfds);
 490         max_fileno = sockfd;
 491         FD_SET(signal_pipe, &rfds);
 492         max_fileno = MAX(max_fileno, signal_pipe);
 493
 494         timeout = afs_preselect();
 495         status_refresh();
 496         for (i = 0; senders[i].name; i++) {
 497                 if (senders[i].status != SENDER_ON)
 498                         continue;
 499                 if (!senders[i].pre_select)
 500                         continue;
 501                 senders[i].pre_select(mmd->audio_format >= 0?
 502                         &afl[mmd->audio_format] : NULL,
 503                         &max_fileno,
 504                         &rfds, &wfds);
 505         }
 506         mmd_unlock();
 507 //      PARA_DEBUG_LOG("%s: select (max = %i)\n", __func__, max_fileno);
 508         ret = select(max_fileno + 1, &rfds, &wfds, NULL, timeout);
 509         err = errno;
 510         //PARA_DEBUG_LOG("%s: select returned  %i\n", __func__, ret);
 511         mmd_lock();
 512         if (mmd->dbt_change >= 0)
 513                 handle_dbt_change();
 514         if (ret < 0 && err == EINTR)
 515                 goto repeat;
 516         if (ret < 0) {
 517                 PARA_CRIT_LOG("select error (%s)\n", strerror(err));
 518                 goto repeat;
 519         }
 520         for (i = 0; senders[i].name; i++) {
 521                 if (senders[i].status != SENDER_ON)
 522                         continue;
 523                 if (!senders[i].post_select)
 524                         continue;
 525                 senders[i].post_select(mmd->audio_format >= 0?
 526                         &afl[mmd->audio_format] : NULL,
 527                         &rfds, &wfds);
 528         }
 529         if (!ret) {
 530                 afs_send_chunk();
 531                 status_refresh();
 532         }
 533         if (FD_ISSET(signal_pipe, &rfds)) {
 534                 int sig;
 535                 sig = para_next_signal();
 536                 switch (sig) {
 537                 case SIGHUP:
 538                         handle_sighup();
 539                         break;
 540                 case SIGCHLD:
 541                         para_reap_children();
 542                         break;
 543                 /* die on sigint/sigterm. Kill all children too. */
 544                 case SIGINT:
 545                 case SIGTERM:
 546                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 547                         kill(0, SIGTERM);
 548                         exit(EXIT_FAILURE);
 549                 }
 550         }
 551         if (mmd->sender_cmd_data.cmd_num >= 0) {
 552                 int num = mmd->sender_cmd_data.cmd_num,
 553                         s = mmd->sender_cmd_data.sender_num;
 554
 555                 if (senders[s].client_cmds[num])
 556                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 557                 mmd->sender_cmd_data.cmd_num = -1;
 558         }
 559         if (!FD_ISSET(sockfd, &rfds))
 560                 goto repeat;
 561
 562         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 563         if (new_fd < 0)
 564                 goto repeat;
 565         PARA_INFO_LOG("got connection from %s, forking\n",
 566                 inet_ntoa(their_addr.sin_addr));
 567         mmd->num_connects++;
 568         mmd->active_connections++;
 569         random();
 570         chld_pid = fork();
 571         if (chld_pid < 0) {
 572                 PARA_CRIT_LOG("%s", "fork failed\n");
 573                 goto repeat;
 574         }
 575         if (chld_pid) {
 576                 close(new_fd);
 577                 /* parent keeps accepting connections */
 578                 goto repeat;
 579         }
 580         alarm(ALARM_TIMEOUT);
 581         close_listed_fds();
 582         close(sockfd); /* child doesn't need the listener */
 583         /*
 584          * put info on who we are serving into argv[0] to make
 585          * client ip visible in top/ps
 586          */
 587         for (i = argc - 1; i >= 0; i--)
 588                 memset(argv[i], 0, strlen(argv[i]));
 589         sprintf(argv[0], "para_server (serving %s)",
 590                 inet_ntoa(their_addr.sin_addr));
 591         return handle_connect(new_fd, &their_addr);
 592 }