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
  46 /** define the array of error lists needed by para_server */
  47 INIT_SERVER_ERRLISTS;
  48
  49 /** shut down non-authorized connections after that many seconds */
  50 #define ALARM_TIMEOUT 10
  51
  52 /* these are exported to afs.c. command.c and to all selectors */
  53 struct misc_meta_data *mmd;
  54 /** the configuration of para_server
  55  *
  56  * It also contains the options for all audio file selectors and all supported
  57  * senders.
  58 */
  59 struct server_args_info conf;
  60 char *user_list = NULL;
  61 extern void dccp_send_init(struct sender *);
  62 extern void http_send_init(struct sender *);
  63 extern void ortp_send_init(struct sender *);
  64
  65 /* TODO: This is better handled by autoconf */
  66 /** the list of supported audio file selectors */
  67 struct audio_file_selector selectors[] = {
  68         {
  69                 .name = "random",
  70                 .init = random_selector_init,
  71                 .update_audio_file = NULL,
  72         },
  73         {
  74                 .name = "playlist",
  75                 .init = playlist_selector_init,
  76                 .update_audio_file = NULL,
  77                 .pre_select = NULL,
  78                 .post_select = NULL,
  79         },
  80 #ifdef HAVE_MYSQL
  81         {
  82                 .name = "mysql",
  83                 .init = mysql_selector_init,
  84                 .update_audio_file = NULL,
  85                 .pre_select = NULL,
  86                 .post_select = NULL,
  87         },
  88 #endif
  89         {
  90                 .name = NULL,
  91         }
  92 };
  93
  94 /** the list of supported senders */
  95 struct sender senders[] = {
  96         {
  97                 .name = "http",
  98                 .init = http_send_init,
  99         },
 100         {
 101                 .name = "dccp",
 102                 .init = dccp_send_init,
 103         },
 104 #ifdef HAVE_ORTP
 105         {
 106                 .name = "ortp",
 107                 .init = ortp_send_init,
 108         },
 109 #endif
 110         {
 111                 .name = NULL,
 112         }
 113 };
 114
 115
 116 /* global variables for server-internal use */
 117 static FILE *logfile;
 118 static int mmd_mutex, mmd_shm_id;
 119 static int signal_pipe;
 120
 121 /**
 122  * para_server's log function
 123  *
 124  * \param ll the log level
 125  * \param fmt the format string describing the log message
 126  */
 127 void para_log(int ll, const char* fmt,...)
 128 {
 129         va_list argp;
 130         FILE *outfd;
 131         struct tm *tm;
 132         time_t t1;
 133         char str[MAXLINE] = "";
 134         pid_t mypid;
 135
 136         if (ll < conf.loglevel_arg)
 137                 return;
 138         outfd = logfile? logfile : stderr;
 139         time(&t1);
 140         tm = localtime(&t1);
 141         strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
 142         fprintf(outfd, "%s ", str);
 143         if (conf.loglevel_arg <= INFO)
 144                 fprintf(outfd, "%i: ", ll);
 145         mypid = getpid();
 146         if (conf.loglevel_arg <= INFO)
 147                 fprintf(outfd, "(%d) ", mypid);
 148         va_start(argp, fmt);
 149         vfprintf(outfd, fmt, argp);
 150         va_end(argp);
 151 }
 152
 153 /*
 154  * setup shared memory area and get mutex for locking
 155  */
 156 static void shm_init(void)
 157 {
 158         void *shm;
 159         int ret = shm_new(sizeof(struct misc_meta_data));
 160
 161         if (ret < 0)
 162                 goto err_out;
 163
 164         ret = shm_attach(ret, ATTACH_RW, &shm);
 165         if (ret < 0)
 166                 goto err_out;
 167         mmd = shm;
 168         mmd_shm_id = ret;
 169
 170         ret = mutex_new();
 171         if (ret < 0)
 172                 goto err_out;
 173         mmd_mutex = ret;
 174
 175         mmd->selector_num = 0;
 176         mmd->num_played = 0;
 177         mmd->num_commands = 0;
 178         mmd->events = 0;
 179         mmd->num_connects = 0;
 180         mmd->active_connections = 0;
 181         strcpy(mmd->filename, "(none)");
 182         mmd->audio_format = -1;
 183         mmd->afs_status_flags = AFS_NEXT;
 184         mmd->new_afs_status_flags = AFS_NEXT;
 185         mmd->sender_cmd_data.cmd_num = -1;
 186         return;
 187 err_out:
 188         PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
 189         exit(EXIT_FAILURE);
 190 }
 191
 192 /**
 193  * lock the shared memory area containing the mmd struct
 194  *
 195  * \sa semop(2), struct misc_meta_data
 196  */
 197 void mmd_lock(void)
 198 {
 199         mutex_lock(mmd_mutex);
 200 }
 201
 202 /**
 203  * unlock the shared memory area containing the mmd struct
 204  *
 205  * \sa semop(2), struct misc_meta_data
 206  */
 207
 208 void mmd_unlock(void)
 209 {
 210         mutex_unlock(mmd_mutex);
 211 }
 212
 213 static void parse_config(int override)
 214 {
 215         char *home = para_homedir();
 216         struct stat statbuf;
 217         int ret;
 218         char *cf;
 219
 220         if (conf.config_file_given)
 221                 cf = conf.config_file_arg;
 222         else
 223                 cf = make_message("%s/.paraslash/server.conf", home);
 224         free(user_list);
 225         if (!conf.user_list_given)
 226                 user_list = make_message("%s/.paraslash/server.users", home);
 227         else
 228                 user_list = para_strdup(conf.user_list_arg);
 229         ret = stat(cf, &statbuf);
 230         if (ret && conf.config_file_given) {
 231                 ret = -1;
 232                 PARA_EMERG_LOG("can not stat config file %s\n", cf);
 233                 goto out;
 234         }
 235         if (!ret) {
 236                 int tmp = conf.daemon_given;
 237                 server_cmdline_parser_configfile(cf, &conf, override, 0, 0);
 238                 conf.daemon_given = tmp;
 239         }
 240         /* logfile */
 241         if (!conf.logfile_given && conf.daemon_given) {
 242                 ret = -1;
 243                 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
 244                 goto out;
 245         }
 246         if (conf.logfile_given)
 247                 logfile = open_log(conf.logfile_arg);
 248         ret = 1;
 249 out:
 250         free(cf);
 251         free(home);
 252         if (ret > 0)
 253                 return;
 254         free(user_list);
 255         user_list = NULL;
 256         exit(EXIT_FAILURE);
 257 }
 258
 259 static void setup_signal_handling(void)
 260 {
 261         int ret = 0;
 262
 263         signal_pipe = para_signal_init();
 264         PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
 265         ret += para_install_sighandler(SIGINT);
 266         ret += para_install_sighandler(SIGTERM);
 267         ret += para_install_sighandler(SIGHUP);
 268         ret += para_install_sighandler(SIGCHLD);
 269         ret += para_install_sighandler(SIGUSR1);
 270         signal(SIGPIPE, SIG_IGN);
 271         if (ret != 5) {
 272                 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
 273                 exit(EXIT_FAILURE);
 274         }
 275 }
 276
 277 static void init_selector(void)
 278 {
 279         int i, ret;
 280
 281         mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
 282         if (!conf.selector_given)
 283                 goto random;
 284         for (i = 0; selectors[i].name; i++) {
 285                 if (strcmp(selectors[i].name, conf.selector_arg))
 286                         continue;
 287                 PARA_NOTICE_LOG("initializing %s audio file selector\n",
 288                         selectors[i].name);
 289                 ret = selectors[i].init(&selectors[i]);
 290                 if (ret < 0) {
 291                         PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
 292                         break;
 293                 }
 294                 mmd->selector_num = i;
 295                 return;
 296         }
 297         PARA_WARNING_LOG("%s", "falling back to the random selector\n");
 298 random:
 299         mmd->selector_num = 0;
 300         selectors[0].init(&selectors[0]); /* always successful */
 301 }
 302
 303 static unsigned init_network(void)
 304 {
 305         int sockfd = init_tcp_socket(conf.port_arg);
 306
 307         if (sockfd < 0)
 308                 exit(EXIT_FAILURE);
 309         return sockfd;
 310 }
 311
 312 static void init_random_seed(void)
 313 {
 314         int fd, ret = -1, len = sizeof(unsigned int);
 315         unsigned int seed;
 316
 317         fd = open("/dev/urandom", O_RDONLY);
 318         if (fd < 0)
 319                 goto out;
 320         ret = -2;
 321         if (read(fd, &seed, len) != len)
 322                 goto out;
 323         srandom(seed);
 324         ret = 1;
 325 out:
 326         if (fd >= 0)
 327                 close(fd);
 328         if (ret > 0)
 329                 return;
 330         PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
 331                 ret);
 332         exit(EXIT_FAILURE);
 333 }
 334
 335 static unsigned do_inits(int argc, char **argv)
 336 {
 337         /* connector's address information */
 338         int sockfd;
 339
 340         init_random_seed();
 341         /* parse command line options */
 342         server_cmdline_parser(argc, argv, &conf);
 343         para_drop_privileges(conf.user_arg, conf.group_arg);
 344         /* parse config file, open log and set defaults */
 345         parse_config(0);
 346         log_welcome("para_server", conf.loglevel_arg);
 347         shm_init(); /* init mmd struct */
 348         server_uptime(UPTIME_SET); /* reset server uptime */
 349         /* become daemon */
 350         if (conf.daemon_given)
 351                 daemon_init();
 352         init_selector();
 353         PARA_NOTICE_LOG("%s", "initializing audio file sender\n");
 354         /* audio file sender */
 355         afs_init();
 356         mmd->server_pid = getpid();
 357         setup_signal_handling();
 358         mmd_lock();
 359         /* init network socket */
 360         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 361         sockfd = init_network();
 362         if (conf.autoplay_given) {
 363                 mmd->afs_status_flags |= AFS_PLAYING;
 364                 mmd->new_afs_status_flags |= AFS_PLAYING;
 365         }
 366         PARA_NOTICE_LOG("%s", "init complete\n");
 367         return sockfd;
 368 }
 369
 370 static void change_selector(void)
 371 {
 372         int ret, old = mmd->selector_num, new = mmd->selector_change;
 373
 374         selectors[old].shutdown();
 375         ret = selectors[new].init(&selectors[new]);
 376         mmd->selector_change = -1; /* reset */
 377         if (ret >= 0) {
 378                 mmd->selector_num = new;
 379                 return;
 380         }
 381         /* init failed */
 382         PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
 383         selectors[0].init(&selectors[0]);
 384         mmd->selector_num = 0;
 385 }
 386
 387 /*
 388  * called when server gets SIGHUP or when client invokes hup command.
 389  */
 390 static void handle_sighup(void)
 391 {
 392         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 393         close_log(logfile); /* gets reopened if necessary by parse_config */
 394         logfile = NULL;
 395         parse_config(1); /* reopens log */
 396         mmd->selector_change = mmd->selector_num; /* do not change selector.. */
 397         change_selector(); /* .. just reload */
 398 }
 399
 400 static void status_refresh(void)
 401 {
 402         static int prev_uptime = -1, prev_events = -1;
 403         int uptime = server_uptime(UPTIME_GET), ret = 1;
 404
 405         if (prev_events != mmd->events)
 406                 goto out;
 407         if (mmd->new_afs_status_flags != mmd->afs_status_flags)
 408                 goto out;
 409         if (uptime / 60 != prev_uptime / 60)
 410                 goto out;
 411         ret = 0;
 412 out:
 413         prev_uptime = uptime;
 414         prev_events = mmd->events;
 415         mmd->afs_status_flags = mmd->new_afs_status_flags;
 416         if (ret) {
 417                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 418                         mmd->events, mmd->audio_format);
 419                 killpg(0, SIGUSR1);
 420         }
 421 }
 422
 423 /*
 424  * MAIN
 425  */
 426 int main(int argc, char *argv[])
 427 {
 428         /* listen on sock_fd, new connection on new_fd */
 429         int sockfd, new_fd;
 430         struct sockaddr_in their_addr;
 431         int i, max_fileno, ret;
 432         pid_t chld_pid;
 433         fd_set rfds, wfds;
 434         struct timeval *timeout;
 435
 436         valid_fd_012();
 437         sockfd = do_inits(argc, argv);
 438 repeat:
 439         FD_ZERO(&rfds);
 440         FD_ZERO(&wfds);
 441         max_fileno = -1;
 442         /* check socket and signal pipe in any case */
 443         para_fd_set(sockfd, &rfds, &max_fileno);
 444         para_fd_set(signal_pipe, &rfds, &max_fileno);
 445         timeout = afs_preselect();
 446         status_refresh();
 447         for (i = 0; senders[i].name; i++) {
 448                 if (senders[i].status != SENDER_ON)
 449                         continue;
 450                 if (!senders[i].pre_select)
 451                         continue;
 452                 senders[i].pre_select( &max_fileno, &rfds, &wfds);
 453         }
 454         if (selectors[mmd->selector_num].pre_select) {
 455                 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
 456                 max_fileno = PARA_MAX(max_fileno, ret);
 457         }
 458         mmd_unlock();
 459         ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
 460         mmd_lock();
 461         if (mmd->selector_change >= 0)
 462                 change_selector();
 463         if (selectors[mmd->selector_num].post_select)
 464                 selectors[mmd->selector_num].post_select(&rfds, &wfds);
 465         if (ret < 0)
 466                 goto repeat;
 467         for (i = 0; senders[i].name; i++) {
 468                 if (senders[i].status != SENDER_ON)
 469                         continue;
 470                 if (!senders[i].post_select)
 471                         continue;
 472                 senders[i].post_select(&rfds, &wfds);
 473         }
 474         afs_send_chunk();
 475         status_refresh();
 476         if (FD_ISSET(signal_pipe, &rfds)) {
 477                 int sig;
 478                 sig = para_next_signal();
 479                 switch (sig) {
 480                 case SIGHUP:
 481                         handle_sighup();
 482                         break;
 483                 case SIGCHLD:
 484                         para_reap_children();
 485                         break;
 486                 /* die on sigint/sigterm. Kill all children too. */
 487                 case SIGINT:
 488                 case SIGTERM:
 489                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 490                         kill(0, SIGTERM);
 491                         selectors[mmd->selector_num].shutdown();
 492                         mutex_destroy(mmd_mutex);
 493                         shm_detach(mmd);
 494                         shm_destroy(mmd_shm_id);
 495                         exit(EXIT_FAILURE);
 496                 }
 497         }
 498         if (mmd->sender_cmd_data.cmd_num >= 0) {
 499                 int num = mmd->sender_cmd_data.cmd_num,
 500                         s = mmd->sender_cmd_data.sender_num;
 501
 502                 if (senders[s].client_cmds[num])
 503                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 504                 mmd->sender_cmd_data.cmd_num = -1;
 505         }
 506         if (!FD_ISSET(sockfd, &rfds))
 507                 goto repeat;
 508
 509         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 510         if (new_fd < 0)
 511                 goto repeat;
 512         PARA_INFO_LOG("got connection from %s, forking\n",
 513                 inet_ntoa(their_addr.sin_addr));
 514         mmd->num_connects++;
 515         mmd->active_connections++;
 516         random();
 517         chld_pid = fork();
 518         if (chld_pid < 0) {
 519                 PARA_CRIT_LOG("%s", "fork failed\n");
 520                 goto repeat;
 521         }
 522         if (chld_pid) {
 523                 close(new_fd);
 524                 /* parent keeps accepting connections */
 525                 goto repeat;
 526         }
 527         alarm(ALARM_TIMEOUT);
 528         close_listed_fds();
 529         close(sockfd); /* child doesn't need the listener */
 530         /*
 531          * put info on who we are serving into argv[0] to make
 532          * client ip visible in top/ps
 533          */
 534         for (i = argc - 1; i >= 0; i--)
 535                 memset(argv[i], 0, strlen(argv[i]));
 536         sprintf(argv[0], "para_server (serving %s)",
 537                 inet_ntoa(their_addr.sin_addr));
 538         return handle_connect(new_fd, &their_addr);
 539 }