server.c

   1 /*
   2  * Copyright (C) 1997-2007 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file server.c Paraslash's main server */
   8
   9
  10 /** \mainpage Paraslash API Reference
  11  *
  12  *  Good starting points for reading are probably \ref audio_file_selector,
  13  *  \ref sender, \ref receiver, \ref receiver_node, \ref filter, \ref
  14  *  filter_node.
  15  *
  16  */
  17
  18 #include <sys/types.h>
  19 #include <dirent.h>
  20
  21 #include "para.h"
  22 #include "server.cmdline.h"
  23 #include "afs_common.h"
  24 #include "afh.h"
  25 #include "server.h"
  26 #include "vss.h"
  27 #include "config.h"
  28 #include "close_on_fork.h"
  29 #include "send.h"
  30 #include "error.h"
  31 #include "net.h"
  32 #include "daemon.h"
  33 #include "string.h"
  34 #include "ipc.h"
  35 #include "fd.h"
  36 #include "list.h"
  37 #include "sched.h"
  38 #include "signal.h"
  39 #include "user_list.h"
  40 #include "afs.h"
  41
  42 /** define the array of error lists needed by para_server */
  43 INIT_SERVER_ERRLISTS;
  44
  45 /** shut down non-authorized connections after that many seconds */
  46 #define ALARM_TIMEOUT 10
  47
  48 /**
  49  * pointer to shared memory area for communication between para_server
  50  * and its children. exported to vss.c. command.c and to all selectors.
  51  */
  52 struct misc_meta_data *mmd;
  53
  54 /**
  55  * the configuration of para_server
  56  *
  57  * It also contains the options for all audio file selectors, audio format handler
  58  * and all supported senders.
  59  */
  60 struct server_args_info conf;
  61
  62 /** the file containing user information (public key, permissions) */
  63 char *user_list_file = NULL;
  64
  65 extern void dccp_send_init(struct sender *);
  66 extern void http_send_init(struct sender *);
  67 extern void ortp_send_init(struct sender *);
  68
  69 /* TODO: This is better handled by autoconf */
  70 /** the list of supported audio file selectors */
  71 struct audio_file_selector selectors[] = {
  72         {
  73                 .name = "random",
  74                 .init = random_selector_init,
  75                 .update_audio_file = NULL,
  76         },
  77         {
  78                 .name = "playlist",
  79                 .init = playlist_selector_init,
  80                 .update_audio_file = NULL,
  81                 .pre_select = NULL,
  82                 .post_select = NULL,
  83         },
  84 #ifdef HAVE_MYSQL
  85         {
  86                 .name = "mysql",
  87                 .init = mysql_selector_init,
  88                 .update_audio_file = NULL,
  89                 .pre_select = NULL,
  90                 .post_select = NULL,
  91         },
  92 #endif
  93         {
  94                 .name = NULL,
  95         }
  96 };
  97
  98 /** the list of supported senders */
  99 struct sender senders[] = {
 100         {
 101                 .name = "http",
 102                 .init = http_send_init,
 103         },
 104         {
 105                 .name = "dccp",
 106                 .init = dccp_send_init,
 107         },
 108 #ifdef HAVE_ORTP
 109         {
 110                 .name = "ortp",
 111                 .init = ortp_send_init,
 112         },
 113 #endif
 114         {
 115                 .name = NULL,
 116         }
 117 };
 118
 119
 120 /* global variables for server-internal use */
 121 static FILE *logfile;
 122 static int mmd_mutex, mmd_shm_id;
 123 static int signal_pipe;
 124
 125 /**
 126  * para_server's log function
 127  *
 128  * \param ll the log level
 129  * \param fmt the format string describing the log message
 130  */
 131 void para_log(int ll, const char* fmt,...)
 132 {
 133         va_list argp;
 134         FILE *outfd;
 135         struct tm *tm;
 136         time_t t1;
 137         char str[MAXLINE] = "";
 138         pid_t mypid;
 139
 140         if (ll < conf.loglevel_arg)
 141                 return;
 142         outfd = logfile? logfile : stderr;
 143         time(&t1);
 144         tm = localtime(&t1);
 145         strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
 146         fprintf(outfd, "%s ", str);
 147         if (conf.loglevel_arg <= INFO)
 148                 fprintf(outfd, "%i: ", ll);
 149         mypid = getpid();
 150         if (conf.loglevel_arg <= INFO)
 151                 fprintf(outfd, "(%d) ", mypid);
 152         va_start(argp, fmt);
 153         vfprintf(outfd, fmt, argp);
 154         va_end(argp);
 155 }
 156
 157 /*
 158  * setup shared memory area and get mutex for locking
 159  */
 160 static void shm_init(void)
 161 {
 162         void *shm;
 163         int ret = shm_new(sizeof(struct misc_meta_data));
 164
 165         if (ret < 0)
 166                 goto err_out;
 167
 168         ret = shm_attach(ret, ATTACH_RW, &shm);
 169         if (ret < 0)
 170                 goto err_out;
 171         mmd = shm;
 172         mmd_shm_id = ret;
 173
 174         ret = mutex_new();
 175         if (ret < 0)
 176                 goto err_out;
 177         mmd_mutex = ret;
 178
 179         mmd->selector_num = 0;
 180         mmd->num_played = 0;
 181         mmd->num_commands = 0;
 182         mmd->events = 0;
 183         mmd->num_connects = 0;
 184         mmd->active_connections = 0;
 185         strcpy(mmd->filename, "(none)");
 186         mmd->audio_format = -1;
 187         mmd->vss_status_flags = VSS_NEXT;
 188         mmd->new_vss_status_flags = VSS_NEXT;
 189         mmd->sender_cmd_data.cmd_num = -1;
 190         return;
 191 err_out:
 192         PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
 193         exit(EXIT_FAILURE);
 194 }
 195
 196 /**
 197  * lock the shared memory area containing the mmd struct
 198  *
 199  * \sa semop(2), struct misc_meta_data
 200  */
 201 void mmd_lock(void)
 202 {
 203         mutex_lock(mmd_mutex);
 204 }
 205
 206 /**
 207  * unlock the shared memory area containing the mmd struct
 208  *
 209  * \sa semop(2), struct misc_meta_data
 210  */
 211
 212 void mmd_unlock(void)
 213 {
 214         mutex_unlock(mmd_mutex);
 215 }
 216
 217 static void parse_config(int override)
 218 {
 219         char *home = para_homedir();
 220         struct stat statbuf;
 221         int ret;
 222         char *cf;
 223
 224         if (conf.config_file_given)
 225                 cf = conf.config_file_arg;
 226         else
 227                 cf = make_message("%s/.paraslash/server.conf", home);
 228         free(user_list_file);
 229         if (!conf.user_list_given)
 230                 user_list_file = make_message("%s/.paraslash/server.users", home);
 231         else
 232                 user_list_file = para_strdup(conf.user_list_arg);
 233         ret = stat(cf, &statbuf);
 234         if (ret && conf.config_file_given) {
 235                 ret = -1;
 236                 PARA_EMERG_LOG("can not stat config file %s\n", cf);
 237                 goto out;
 238         }
 239         if (!ret) {
 240                 int tmp = conf.daemon_given;
 241                 struct server_cmdline_parser_params params = {
 242                         .override = override,
 243                         .initialize = 0,
 244                         .check_required = 0,
 245                         .check_ambiguity = 0
 246                 };
 247                 server_cmdline_parser_config_file(cf, &conf, &params);
 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 uint32_t afs_socket_cookie;
 354 static int afs_socket;
 355 pid_t afs_pid;
 356
 357 static void init_afs(void)
 358 {
 359         int ret, afs_server_socket[2];
 360
 361         ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
 362         if (ret < 0)
 363                 exit(EXIT_FAILURE);
 364         afs_socket_cookie = para_random((uint32_t)-1);
 365         afs_pid = fork();
 366         if (afs_pid < 0)
 367                 exit(EXIT_FAILURE);
 368         if (!afs_pid) { /* child (afs) */
 369                 close(afs_server_socket[0]);
 370                 afs_init(afs_socket_cookie, afs_server_socket[1]);
 371         }
 372         close(afs_server_socket[1]);
 373         afs_socket = afs_server_socket[0];
 374         ret = mark_fd_nonblock(afs_socket);
 375         if (ret < 0)
 376                 exit(EXIT_FAILURE);
 377         add_close_on_fork_list(afs_socket);
 378         PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n", afs_socket,
 379                 (unsigned) afs_socket_cookie);
 380 }
 381
 382
 383 static unsigned do_inits(int argc, char **argv)
 384 {
 385         /* connector's address information */
 386         int sockfd;
 387
 388         init_random_seed();
 389         /* parse command line options */
 390         server_cmdline_parser(argc, argv, &conf);
 391         HANDLE_VERSION_FLAG("server", conf);
 392         para_drop_privileges(conf.user_arg, conf.group_arg);
 393         /* parse config file, open log and set defaults */
 394         parse_config(0);
 395         log_welcome("para_server", conf.loglevel_arg);
 396         shm_init(); /* init mmd struct */
 397         server_uptime(UPTIME_SET); /* reset server uptime */
 398         init_user_list(user_list_file);
 399         /* become daemon */
 400         if (conf.daemon_given)
 401                 daemon_init();
 402         init_selector();
 403 //      PARA_ERROR_LOG("num: %d\n", mmd->selector_num);
 404         PARA_NOTICE_LOG("%s", "initializing virtual streaming system\n");
 405         vss_init();
 406         mmd->server_pid = getpid();
 407         setup_signal_handling();
 408         init_afs();
 409         mmd_lock();
 410         /* init network socket */
 411         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 412         sockfd = init_network();
 413         PARA_NOTICE_LOG("%s", "init complete\n");
 414         return sockfd;
 415 }
 416
 417 static void change_selector(void)
 418 {
 419         int ret, old = mmd->selector_num, new = mmd->selector_change;
 420
 421         selectors[old].shutdown();
 422         ret = selectors[new].init(&selectors[new]);
 423         mmd->selector_change = -1; /* reset */
 424         if (ret >= 0) {
 425                 mmd->selector_num = new;
 426                 return;
 427         }
 428         /* init failed */
 429         PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
 430         selectors[0].init(&selectors[0]);
 431         mmd->selector_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->selector_change = mmd->selector_num; /* do not change selector.. */
 444         change_selector(); /* .. just reload */
 445         init_user_list(user_list_file); /* reload user list */
 446 }
 447
 448 static void status_refresh(void)
 449 {
 450         static int prev_uptime = -1, prev_events = -1;
 451         int uptime = server_uptime(UPTIME_GET), ret = 1;
 452
 453         if (prev_events != mmd->events)
 454                 goto out;
 455         if (mmd->new_vss_status_flags != mmd->vss_status_flags)
 456                 goto out;
 457         if (uptime / 60 != prev_uptime / 60)
 458                 goto out;
 459         ret = 0;
 460 out:
 461         prev_uptime = uptime;
 462         prev_events = mmd->events;
 463         mmd->vss_status_flags = mmd->new_vss_status_flags;
 464         if (ret) {
 465                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 466                         mmd->events, mmd->audio_format);
 467                 killpg(0, SIGUSR1);
 468         }
 469 }
 470
 471 /**
 472  * the main function of para_server
 473  *
 474  * \param argc usual argument count
 475  * \param argv usual argument vector
 476  *
 477  * \return EXIT_SUCCESS or EXIT_FAILURE
 478  *
 479  */
 480 int main(int argc, char *argv[])
 481 {
 482         /* listen on sock_fd, new connection on new_fd */
 483         int sockfd, new_fd;
 484         struct sockaddr_in their_addr;
 485         int i, max_fileno, ret;
 486         pid_t chld_pid;
 487         fd_set rfds, wfds;
 488         struct timeval *timeout;
 489
 490         valid_fd_012();
 491         sockfd = do_inits(argc, argv);
 492 repeat:
 493         FD_ZERO(&rfds);
 494         FD_ZERO(&wfds);
 495         max_fileno = -1;
 496         /* check socket and signal pipe in any case */
 497         para_fd_set(sockfd, &rfds, &max_fileno);
 498         para_fd_set(signal_pipe, &rfds, &max_fileno);
 499         timeout = vss_preselect();
 500         status_refresh();
 501         for (i = 0; senders[i].name; i++) {
 502                 if (senders[i].status != SENDER_ON)
 503                         continue;
 504                 if (!senders[i].pre_select)
 505                         continue;
 506                 senders[i].pre_select( &max_fileno, &rfds, &wfds);
 507         }
 508         if (selectors[mmd->selector_num].pre_select) {
 509                 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
 510                 max_fileno = PARA_MAX(max_fileno, ret);
 511         }
 512         mmd_unlock();
 513         ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
 514         mmd_lock();
 515         if (mmd->selector_change >= 0)
 516                 change_selector();
 517         if (selectors[mmd->selector_num].post_select)
 518                 selectors[mmd->selector_num].post_select(&rfds, &wfds);
 519         if (ret < 0)
 520                 goto repeat;
 521         for (i = 0; senders[i].name; i++) {
 522                 if (senders[i].status != SENDER_ON)
 523                         continue;
 524                 if (!senders[i].post_select)
 525                         continue;
 526                 senders[i].post_select(&rfds, &wfds);
 527         }
 528         vss_send_chunk();
 529         status_refresh();
 530         if (FD_ISSET(signal_pipe, &rfds)) {
 531                 int sig;
 532                 pid_t pid;
 533                 sig = para_next_signal();
 534                 switch (sig) {
 535                 case SIGHUP:
 536                         handle_sighup();
 537                         break;
 538                 case SIGCHLD:
 539                         for (;;) {
 540                                 pid = para_reap_child();
 541                                 if (pid <= 0)
 542                                         break;
 543                                 if (pid != afs_pid)
 544                                         continue;
 545                                 PARA_EMERG_LOG("fatal: afs died\n");
 546                                 goto genocide;
 547                         }
 548                         break;
 549                 /* die on sigint/sigterm. Kill all children too. */
 550                 case SIGINT:
 551                 case SIGTERM:
 552                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 553 genocide:
 554                         kill(0, SIGTERM);
 555                         selectors[mmd->selector_num].shutdown();
 556                         mutex_destroy(mmd_mutex);
 557                         shm_detach(mmd);
 558                         shm_destroy(mmd_shm_id);
 559
 560                         exit(EXIT_FAILURE);
 561                 }
 562         }
 563         if (mmd->sender_cmd_data.cmd_num >= 0) {
 564                 int num = mmd->sender_cmd_data.cmd_num,
 565                         s = mmd->sender_cmd_data.sender_num;
 566
 567                 if (senders[s].client_cmds[num])
 568                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 569                 mmd->sender_cmd_data.cmd_num = -1;
 570         }
 571         if (!FD_ISSET(sockfd, &rfds))
 572                 goto repeat;
 573
 574         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 575         if (new_fd < 0)
 576                 goto repeat;
 577         PARA_INFO_LOG("got connection from %s, forking\n",
 578                 inet_ntoa(their_addr.sin_addr));
 579         mmd->num_connects++;
 580         mmd->active_connections++;
 581         random();
 582         chld_pid = fork();
 583         if (chld_pid < 0) {
 584                 PARA_CRIT_LOG("%s", "fork failed\n");
 585                 goto repeat;
 586         }
 587         if (chld_pid) {
 588                 close(new_fd);
 589                 /* parent keeps accepting connections */
 590                 goto repeat;
 591         }
 592         alarm(ALARM_TIMEOUT);
 593         close_listed_fds();
 594         close(sockfd); /* child doesn't need the listener */
 595         /*
 596          * put info on who we are serving into argv[0] to make
 597          * client ip visible in top/ps
 598          */
 599         for (i = argc - 1; i >= 0; i--)
 600                 memset(argv[i], 0, strlen(argv[i]));
 601         sprintf(argv[0], "para_server (serving %s)",
 602                 inet_ntoa(their_addr.sin_addr));
 603         return handle_connect(new_fd, &their_addr);
 604 }