server.c

   1 /*
   2  * Copyright (C) 1997-2007 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 "afs.h"
  34 #include "server.h"
  35 #include "vss.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 "signal.h"
  46 #include "user_list.h"
  47
  48 /** define the array of error lists needed by para_server */
  49 INIT_SERVER_ERRLISTS;
  50
  51 /** shut down non-authorized connections after that many seconds */
  52 #define ALARM_TIMEOUT 10
  53
  54 /**
  55  * pointer to shared memory area for communication between para_server
  56  * and its children. exported to vss.c. command.c and to all selectors.
  57  */
  58 struct misc_meta_data *mmd;
  59
  60 /**
  61  * the configuration of para_server
  62  *
  63  * It also contains the options for all audio file selectors, audio format handler
  64  * and all supported senders.
  65  */
  66 struct server_args_info conf;
  67
  68 /** the file containing user information (public key, permissions) */
  69 char *user_list_file = NULL;
  70
  71 extern void dccp_send_init(struct sender *);
  72 extern void http_send_init(struct sender *);
  73 extern void ortp_send_init(struct sender *);
  74
  75 /* TODO: This is better handled by autoconf */
  76 /** the list of supported audio file selectors */
  77 struct audio_file_selector selectors[] = {
  78         {
  79                 .name = "random",
  80                 .init = random_selector_init,
  81                 .update_audio_file = NULL,
  82         },
  83         {
  84                 .name = "playlist",
  85                 .init = playlist_selector_init,
  86                 .update_audio_file = NULL,
  87                 .pre_select = NULL,
  88                 .post_select = NULL,
  89         },
  90 #ifdef HAVE_MYSQL
  91         {
  92                 .name = "mysql",
  93                 .init = mysql_selector_init,
  94                 .update_audio_file = NULL,
  95                 .pre_select = NULL,
  96                 .post_select = NULL,
  97         },
  98 #endif
  99         {
 100                 .name = NULL,
 101         }
 102 };
 103
 104 /** the list of supported senders */
 105 struct sender senders[] = {
 106         {
 107                 .name = "http",
 108                 .init = http_send_init,
 109         },
 110         {
 111                 .name = "dccp",
 112                 .init = dccp_send_init,
 113         },
 114 #ifdef HAVE_ORTP
 115         {
 116                 .name = "ortp",
 117                 .init = ortp_send_init,
 118         },
 119 #endif
 120         {
 121                 .name = NULL,
 122         }
 123 };
 124
 125
 126 /* global variables for server-internal use */
 127 static FILE *logfile;
 128 static int mmd_mutex, mmd_shm_id;
 129 static int signal_pipe;
 130
 131 /**
 132  * para_server's log function
 133  *
 134  * \param ll the log level
 135  * \param fmt the format string describing the log message
 136  */
 137 void para_log(int ll, const char* fmt,...)
 138 {
 139         va_list argp;
 140         FILE *outfd;
 141         struct tm *tm;
 142         time_t t1;
 143         char str[MAXLINE] = "";
 144         pid_t mypid;
 145
 146         if (ll < conf.loglevel_arg)
 147                 return;
 148         outfd = logfile? logfile : stderr;
 149         time(&t1);
 150         tm = localtime(&t1);
 151         strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
 152         fprintf(outfd, "%s ", str);
 153         if (conf.loglevel_arg <= INFO)
 154                 fprintf(outfd, "%i: ", ll);
 155         mypid = getpid();
 156         if (conf.loglevel_arg <= INFO)
 157                 fprintf(outfd, "(%d) ", mypid);
 158         va_start(argp, fmt);
 159         vfprintf(outfd, fmt, argp);
 160         va_end(argp);
 161 }
 162
 163 /*
 164  * setup shared memory area and get mutex for locking
 165  */
 166 static void shm_init(void)
 167 {
 168         void *shm;
 169         int ret = shm_new(sizeof(struct misc_meta_data));
 170
 171         if (ret < 0)
 172                 goto err_out;
 173
 174         ret = shm_attach(ret, ATTACH_RW, &shm);
 175         if (ret < 0)
 176                 goto err_out;
 177         mmd = shm;
 178         mmd_shm_id = ret;
 179
 180         ret = mutex_new();
 181         if (ret < 0)
 182                 goto err_out;
 183         mmd_mutex = ret;
 184
 185         mmd->selector_num = 0;
 186         mmd->num_played = 0;
 187         mmd->num_commands = 0;
 188         mmd->events = 0;
 189         mmd->num_connects = 0;
 190         mmd->active_connections = 0;
 191         strcpy(mmd->filename, "(none)");
 192         mmd->audio_format = -1;
 193         mmd->vss_status_flags = VSS_NEXT;
 194         mmd->new_vss_status_flags = VSS_NEXT;
 195         mmd->sender_cmd_data.cmd_num = -1;
 196         return;
 197 err_out:
 198         PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
 199         exit(EXIT_FAILURE);
 200 }
 201
 202 /**
 203  * lock the shared memory area containing the mmd struct
 204  *
 205  * \sa semop(2), struct misc_meta_data
 206  */
 207 void mmd_lock(void)
 208 {
 209         mutex_lock(mmd_mutex);
 210 }
 211
 212 /**
 213  * unlock the shared memory area containing the mmd struct
 214  *
 215  * \sa semop(2), struct misc_meta_data
 216  */
 217
 218 void mmd_unlock(void)
 219 {
 220         mutex_unlock(mmd_mutex);
 221 }
 222
 223 static void parse_config(int override)
 224 {
 225         char *home = para_homedir();
 226         struct stat statbuf;
 227         int ret;
 228         char *cf;
 229
 230         if (conf.config_file_given)
 231                 cf = conf.config_file_arg;
 232         else
 233                 cf = make_message("%s/.paraslash/server.conf", home);
 234         free(user_list_file);
 235         if (!conf.user_list_given)
 236                 user_list_file = make_message("%s/.paraslash/server.users", home);
 237         else
 238                 user_list_file = para_strdup(conf.user_list_arg);
 239         ret = stat(cf, &statbuf);
 240         if (ret && conf.config_file_given) {
 241                 ret = -1;
 242                 PARA_EMERG_LOG("can not stat config file %s\n", cf);
 243                 goto out;
 244         }
 245         if (!ret) {
 246                 int tmp = conf.daemon_given;
 247                 server_cmdline_parser_configfile(cf, &conf, override, 0, 0);
 248                 conf.daemon_given = tmp;
 249         }
 250         /* logfile */
 251         if (!conf.logfile_given && conf.daemon_given) {
 252                 ret = -1;
 253                 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
 254                 goto out;
 255         }
 256         if (conf.logfile_given)
 257                 logfile = open_log(conf.logfile_arg);
 258         ret = 1;
 259 out:
 260         free(cf);
 261         free(home);
 262         if (ret > 0)
 263                 return;
 264         free(user_list_file);
 265         user_list_file = NULL;
 266         exit(EXIT_FAILURE);
 267 }
 268
 269 static void setup_signal_handling(void)
 270 {
 271         int ret = 0;
 272
 273         signal_pipe = para_signal_init();
 274         PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
 275         ret += para_install_sighandler(SIGINT);
 276         ret += para_install_sighandler(SIGTERM);
 277         ret += para_install_sighandler(SIGHUP);
 278         ret += para_install_sighandler(SIGCHLD);
 279         ret += para_install_sighandler(SIGUSR1);
 280         signal(SIGPIPE, SIG_IGN);
 281         if (ret != 5) {
 282                 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
 283                 exit(EXIT_FAILURE);
 284         }
 285 }
 286
 287 static void init_selector(void)
 288 {
 289         int i, ret;
 290
 291         mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
 292         if (!conf.selector_given)
 293                 goto random;
 294         for (i = 0; selectors[i].name; i++) {
 295                 if (strcmp(selectors[i].name, conf.selector_arg))
 296                         continue;
 297                 PARA_NOTICE_LOG("initializing %s audio file selector\n",
 298                         selectors[i].name);
 299                 ret = selectors[i].init(&selectors[i]);
 300                 if (ret < 0) {
 301                         PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
 302                         break;
 303                 }
 304                 mmd->selector_num = i;
 305                 return;
 306         }
 307         PARA_WARNING_LOG("%s", "falling back to the random selector\n");
 308 random:
 309         mmd->selector_num = 0;
 310         selectors[0].init(&selectors[0]); /* always successful */
 311 }
 312
 313 static unsigned init_network(void)
 314 {
 315         int fd, ret = init_tcp_socket(conf.port_arg);
 316
 317         if (ret < 0)
 318                 goto err;
 319         fd = ret;
 320         ret = mark_fd_nonblock(fd);
 321         if (ret < 0)
 322                 goto err;
 323         return fd;
 324 err:
 325         PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
 326         exit(EXIT_FAILURE);
 327 }
 328
 329 static void init_random_seed(void)
 330 {
 331         int fd, ret = -1;
 332         unsigned int seed;
 333         size_t len = sizeof(unsigned int);
 334
 335         fd = open("/dev/urandom", 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         server_cmdline_parser(argc, argv, &conf);
 361         HANDLE_VERSION_FLAG("server", conf);
 362         para_drop_privileges(conf.user_arg, conf.group_arg);
 363         /* parse config file, open log and set defaults */
 364         parse_config(0);
 365         log_welcome("para_server", conf.loglevel_arg);
 366         shm_init(); /* init mmd struct */
 367         server_uptime(UPTIME_SET); /* reset server uptime */
 368         init_user_list(user_list_file);
 369         /* become daemon */
 370         if (conf.daemon_given)
 371                 daemon_init();
 372         init_selector();
 373 //      PARA_ERROR_LOG("num: %d\n", mmd->selector_num);
 374         PARA_NOTICE_LOG("%s", "initializing virtual streaming system\n");
 375         vss_init();
 376         mmd->server_pid = getpid();
 377         setup_signal_handling();
 378         mmd_lock();
 379         /* init network socket */
 380         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 381         sockfd = init_network();
 382         PARA_NOTICE_LOG("%s", "init complete\n");
 383         return sockfd;
 384 }
 385
 386 static void change_selector(void)
 387 {
 388         int ret, old = mmd->selector_num, new = mmd->selector_change;
 389
 390         selectors[old].shutdown();
 391         ret = selectors[new].init(&selectors[new]);
 392         mmd->selector_change = -1; /* reset */
 393         if (ret >= 0) {
 394                 mmd->selector_num = new;
 395                 return;
 396         }
 397         /* init failed */
 398         PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
 399         selectors[0].init(&selectors[0]);
 400         mmd->selector_num = 0;
 401 }
 402
 403 /*
 404  * called when server gets SIGHUP or when client invokes hup command.
 405  */
 406 static void handle_sighup(void)
 407 {
 408         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 409         close_log(logfile); /* gets reopened if necessary by parse_config */
 410         logfile = NULL;
 411         parse_config(1); /* reopens log */
 412         mmd->selector_change = mmd->selector_num; /* do not change selector.. */
 413         change_selector(); /* .. just reload */
 414         init_user_list(user_list_file); /* reload user list */
 415 }
 416
 417 static void status_refresh(void)
 418 {
 419         static int prev_uptime = -1, prev_events = -1;
 420         int uptime = server_uptime(UPTIME_GET), ret = 1;
 421
 422         if (prev_events != mmd->events)
 423                 goto out;
 424         if (mmd->new_vss_status_flags != mmd->vss_status_flags)
 425                 goto out;
 426         if (uptime / 60 != prev_uptime / 60)
 427                 goto out;
 428         ret = 0;
 429 out:
 430         prev_uptime = uptime;
 431         prev_events = mmd->events;
 432         mmd->vss_status_flags = mmd->new_vss_status_flags;
 433         if (ret) {
 434                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 435                         mmd->events, mmd->audio_format);
 436                 killpg(0, SIGUSR1);
 437         }
 438 }
 439
 440 /**
 441  * the main function of para_server
 442  *
 443  * \param argc usual argument count
 444  * \param argv usual argument vector
 445  *
 446  * \return EXIT_SUCCESS or EXIT_FAILURE
 447  *
 448  */
 449 int main(int argc, char *argv[])
 450 {
 451         /* listen on sock_fd, new connection on new_fd */
 452         int sockfd, new_fd;
 453         struct sockaddr_in their_addr;
 454         int i, max_fileno, ret;
 455         pid_t chld_pid;
 456         fd_set rfds, wfds;
 457         struct timeval *timeout;
 458
 459         valid_fd_012();
 460         sockfd = do_inits(argc, argv);
 461 repeat:
 462         FD_ZERO(&rfds);
 463         FD_ZERO(&wfds);
 464         max_fileno = -1;
 465         /* check socket and signal pipe in any case */
 466         para_fd_set(sockfd, &rfds, &max_fileno);
 467         para_fd_set(signal_pipe, &rfds, &max_fileno);
 468         timeout = vss_preselect();
 469         status_refresh();
 470         for (i = 0; senders[i].name; i++) {
 471                 if (senders[i].status != SENDER_ON)
 472                         continue;
 473                 if (!senders[i].pre_select)
 474                         continue;
 475                 senders[i].pre_select( &max_fileno, &rfds, &wfds);
 476         }
 477         if (selectors[mmd->selector_num].pre_select) {
 478                 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
 479                 max_fileno = PARA_MAX(max_fileno, ret);
 480         }
 481         mmd_unlock();
 482         ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
 483         mmd_lock();
 484         if (mmd->selector_change >= 0)
 485                 change_selector();
 486         if (selectors[mmd->selector_num].post_select)
 487                 selectors[mmd->selector_num].post_select(&rfds, &wfds);
 488         if (ret < 0)
 489                 goto repeat;
 490         for (i = 0; senders[i].name; i++) {
 491                 if (senders[i].status != SENDER_ON)
 492                         continue;
 493                 if (!senders[i].post_select)
 494                         continue;
 495                 senders[i].post_select(&rfds, &wfds);
 496         }
 497         vss_send_chunk();
 498         status_refresh();
 499         if (FD_ISSET(signal_pipe, &rfds)) {
 500                 int sig;
 501                 sig = para_next_signal();
 502                 switch (sig) {
 503                 case SIGHUP:
 504                         handle_sighup();
 505                         break;
 506                 case SIGCHLD:
 507                         para_reap_children();
 508                         break;
 509                 /* die on sigint/sigterm. Kill all children too. */
 510                 case SIGINT:
 511                 case SIGTERM:
 512                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 513                         kill(0, SIGTERM);
 514                         selectors[mmd->selector_num].shutdown();
 515                         mutex_destroy(mmd_mutex);
 516                         shm_detach(mmd);
 517                         shm_destroy(mmd_shm_id);
 518                         exit(EXIT_FAILURE);
 519                 }
 520         }
 521         if (mmd->sender_cmd_data.cmd_num >= 0) {
 522                 int num = mmd->sender_cmd_data.cmd_num,
 523                         s = mmd->sender_cmd_data.sender_num;
 524
 525                 if (senders[s].client_cmds[num])
 526                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 527                 mmd->sender_cmd_data.cmd_num = -1;
 528         }
 529         if (!FD_ISSET(sockfd, &rfds))
 530                 goto repeat;
 531
 532         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 533         if (new_fd < 0)
 534                 goto repeat;
 535         PARA_INFO_LOG("got connection from %s, forking\n",
 536                 inet_ntoa(their_addr.sin_addr));
 537         mmd->num_connects++;
 538         mmd->active_connections++;
 539         random();
 540         chld_pid = fork();
 541         if (chld_pid < 0) {
 542                 PARA_CRIT_LOG("%s", "fork failed\n");
 543                 goto repeat;
 544         }
 545         if (chld_pid) {
 546                 close(new_fd);
 547                 /* parent keeps accepting connections */
 548                 goto repeat;
 549         }
 550         alarm(ALARM_TIMEOUT);
 551         close_listed_fds();
 552         close(sockfd); /* child doesn't need the listener */
 553         /*
 554          * put info on who we are serving into argv[0] to make
 555          * client ip visible in top/ps
 556          */
 557         for (i = argc - 1; i >= 0; i--)
 558                 memset(argv[i], 0, strlen(argv[i]));
 559         sprintf(argv[0], "para_server (serving %s)",
 560                 inet_ntoa(their_addr.sin_addr));
 561         return handle_connect(new_fd, &their_addr);
 562 }