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  * Starting points for getting an overview are
  13  *
  14  * probably:
  15  *
  16  *      - The main programs: \ref server.c, \ref audiod.c, \ref client.c,
  17  *        \ref audioc.c, \ref fsck.c
  18  *      - Server: \ref server_command, \ref sender,
  19  *      - Audio file selector: \ref audio_format_handler, \ref mood, \ref afs_table,
  20  *      - Client: \ref receiver, \ref receiver_node, \ref filter, \ref filter_node
  21  *
  22  *
  23  * The gory details, listed by topic:
  24  *
  25  *      - Audio format handlers: \ref mp3_afh.c, \ref ogg_afh.c \ref aac_afh.c
  26  *      - Decoders: \ref mp3dec.c, \ref \ref oggdec.c, \ref aacdec.c
  27  *      - Volume normalizer: \ref compress.c
  28  *      - Output: \ref alsa_write.c, \ref osx_write.c
  29  *      - http: \ref http_recv.c, \ref http_send.c
  30  *      - ortp: \ref ortp_recv.c, \ref ortp_send.c
  31  *      - dccp: \ref dccp_recv.c, \ref dccp_send.c
  32  *      - Audio file selector: \ref afs.c, \ref aft.c, \ref mood.c
  33  *      - Afs structures: \ref afs_table, \ref audio_file_data,
  34  *        \ref afs_info \ref audio_format_info,
  35  *      - Afs tables: \ref aft.c, \ref mood.c, \ref playlist.c,
  36  *        \ref attribute.c, \ref score.c.
  37  *
  38  * Lower levels:
  39  *
  40  *      - Scheduling: \ref sched.c, \ref sched.h
  41  *      - Networking: \ref net.c,
  42  *      - File descriptors: \ref fd.c,
  43  *      - Signals: \ref signal.c,
  44  *      - Daemons: \ref daemon.c,
  45  *      - Strings: \ref string.c, string.h
  46  *      - Time: \ref time.c, time.h
  47  *      - Spawning processes: \ref exec.c
  48  *      - Inter process communication: ipc.c,
  49  *      - The object storage layer: \ref osl.c,
  50  *      - Blob tables: blob.c,
  51  *      - Queueing chunks of audio data: \ref chunk_queue.c
  52  *      - The error subssystem: \ref error.h
  53  *
  54  * Lov-level data structures:
  55  *
  56  *      - Doubly linked lists: \ref list.h,
  57  *      - Red-black trees: \ref rbtree.h, \ref rbtree.c
  58  *      - Ring buffer: \ref ringbuffer.c, \ref ringbuffer.h
  59  *      - Hashing: \ref hash.h, \ref sha1.h, \ref sha1.c
  60  *      - Crypto: \ref crypt.c
  61  *
  62  */
  63
  64 #include <signal.h>
  65 #include <sys/types.h>
  66 #include <dirent.h>
  67
  68 #include "para.h"
  69 #include "error.h"
  70 #include "server.cmdline.h"
  71 #include "afh.h"
  72 #include "string.h"
  73 #include "afs.h"
  74 #include "server.h"
  75 #include "vss.h"
  76 #include "config.h"
  77 #include "close_on_fork.h"
  78 #include "send.h"
  79 #include "net.h"
  80 #include "daemon.h"
  81 #include "ipc.h"
  82 #include "fd.h"
  83 #include "list.h"
  84 #include "sched.h"
  85 #include "signal.h"
  86 #include "user_list.h"
  87
  88 /** define the array of error lists needed by para_server */
  89 INIT_SERVER_ERRLISTS;
  90
  91 /** shut down non-authorized connections after that many seconds */
  92 #define ALARM_TIMEOUT 10
  93
  94 /**
  95  * Pointer to shared memory area for communication between para_server
  96  * and its children. Exported to vss.c. command.c and to afs.
  97  */
  98 struct misc_meta_data *mmd;
  99
 100 /**
 101  * the configuration of para_server
 102  *
 103  * It also contains the options for the audio file selector, audio format
 104  * handler and all supported senders.
 105  */
 106 struct server_args_info conf;
 107
 108 /** the file containing user information (public key, permissions) */
 109 char *user_list_file = NULL;
 110
 111 extern void dccp_send_init(struct sender *);
 112 extern void http_send_init(struct sender *);
 113 extern void ortp_send_init(struct sender *);
 114
 115 /** the list of supported senders */
 116 struct sender senders[] = {
 117         {
 118                 .name = "http",
 119                 .init = http_send_init,
 120         },
 121         {
 122                 .name = "dccp",
 123                 .init = dccp_send_init,
 124         },
 125 #ifdef HAVE_ORTP
 126         {
 127                 .name = "ortp",
 128                 .init = ortp_send_init,
 129         },
 130 #endif
 131         {
 132                 .name = NULL,
 133         }
 134 };
 135
 136
 137 /* global variables for server-internal use */
 138 static FILE *logfile;
 139 static int mmd_mutex, mmd_shm_id;
 140 static int signal_pipe;
 141
 142 /**
 143  * para_server's log function
 144  *
 145  * \param ll the log level
 146  * \param fmt the format string describing the log message
 147  */
 148 void para_log(int ll, const char* fmt,...)
 149 {
 150         va_list argp;
 151         FILE *outfd;
 152         struct tm *tm;
 153         time_t t1;
 154         char str[MAXLINE] = "";
 155         pid_t mypid;
 156
 157         if (ll < conf.loglevel_arg)
 158                 return;
 159         outfd = logfile? logfile : stderr;
 160         time(&t1);
 161         tm = localtime(&t1);
 162         strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
 163         fprintf(outfd, "%s ", str);
 164         if (conf.loglevel_arg <= INFO)
 165                 fprintf(outfd, "%i: ", ll);
 166         mypid = getpid();
 167         if (conf.loglevel_arg <= INFO)
 168                 fprintf(outfd, "(%d) ", mypid);
 169         va_start(argp, fmt);
 170         vfprintf(outfd, fmt, argp);
 171         va_end(argp);
 172 }
 173
 174 /*
 175  * setup shared memory area and get mutex for locking
 176  */
 177 static void shm_init(void)
 178 {
 179         void *shm;
 180         int ret = shm_new(sizeof(struct misc_meta_data));
 181
 182         if (ret < 0)
 183                 goto err_out;
 184
 185         ret = shm_attach(ret, ATTACH_RW, &shm);
 186         if (ret < 0)
 187                 goto err_out;
 188         mmd = shm;
 189         mmd_shm_id = ret;
 190
 191         ret = mutex_new();
 192         if (ret < 0)
 193                 goto err_out;
 194         mmd_mutex = ret;
 195
 196         mmd->num_played = 0;
 197         mmd->num_commands = 0;
 198         mmd->events = 0;
 199         mmd->num_connects = 0;
 200         mmd->active_connections = 0;
 201         strcpy(mmd->afd.path, "(none)");
 202         mmd->vss_status_flags = VSS_NEXT;
 203         mmd->new_vss_status_flags = VSS_NEXT;
 204         mmd->sender_cmd_data.cmd_num = -1;
 205         return;
 206 err_out:
 207         PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
 208         exit(EXIT_FAILURE);
 209 }
 210
 211 /**
 212  * lock the shared memory area containing the mmd struct
 213  *
 214  * \sa semop(2), struct misc_meta_data.
 215  */
 216 void mmd_lock(void)
 217 {
 218         mutex_lock(mmd_mutex);
 219 }
 220
 221 /**
 222  * unlock the shared memory area containing the mmd struct
 223  *
 224  * \sa semop(2), struct misc_meta_data
 225  */
 226
 227 void mmd_unlock(void)
 228 {
 229         mutex_unlock(mmd_mutex);
 230 }
 231
 232 static void parse_config(int override)
 233 {
 234         char *home = para_homedir();
 235         struct stat statbuf;
 236         int ret;
 237         char *cf;
 238
 239         if (conf.config_file_given)
 240                 cf = para_strdup(conf.config_file_arg);
 241         else
 242                 cf = make_message("%s/.paraslash/server.conf", home);
 243         free(user_list_file);
 244         if (!conf.user_list_given)
 245                 user_list_file = make_message("%s/.paraslash/server.users", home);
 246         else
 247                 user_list_file = para_strdup(conf.user_list_arg);
 248         ret = stat(cf, &statbuf);
 249         if (ret && conf.config_file_given) {
 250                 ret = -1;
 251                 PARA_EMERG_LOG("can not stat config file %s\n", cf);
 252                 goto out;
 253         }
 254         if (!ret) {
 255                 int tmp = conf.daemon_given;
 256                 struct server_cmdline_parser_params params = {
 257                         .override = override,
 258                         .initialize = 0,
 259                         .check_required = 0,
 260                         .check_ambiguity = 0
 261                 };
 262                 server_cmdline_parser_config_file(cf, &conf, &params);
 263                 conf.daemon_given = tmp;
 264         }
 265         /* logfile */
 266         if (!conf.logfile_given && conf.daemon_given) {
 267                 ret = -1;
 268                 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
 269                 goto out;
 270         }
 271         if (conf.logfile_given)
 272                 logfile = open_log(conf.logfile_arg);
 273         ret = 1;
 274 out:
 275         free(cf);
 276         free(home);
 277         if (ret > 0)
 278                 return;
 279         free(user_list_file);
 280         user_list_file = NULL;
 281         exit(EXIT_FAILURE);
 282 }
 283
 284 static void setup_signal_handling(void)
 285 {
 286         int ret = 0;
 287
 288         signal_pipe = para_signal_init();
 289         PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
 290         ret += para_install_sighandler(SIGINT);
 291         ret += para_install_sighandler(SIGTERM);
 292         ret += para_install_sighandler(SIGHUP);
 293         ret += para_install_sighandler(SIGCHLD);
 294         ret += para_install_sighandler(SIGUSR1);
 295         signal(SIGPIPE, SIG_IGN);
 296         if (ret != 5) {
 297                 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
 298                 exit(EXIT_FAILURE);
 299         }
 300 }
 301
 302 static unsigned init_network(void)
 303 {
 304         int fd, ret = init_tcp_socket(conf.port_arg);
 305
 306         if (ret < 0)
 307                 goto err;
 308         fd = ret;
 309         ret = mark_fd_nonblock(fd);
 310         if (ret < 0)
 311                 goto err;
 312         return fd;
 313 err:
 314         PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
 315         exit(EXIT_FAILURE);
 316 }
 317
 318 static void init_random_seed(void)
 319 {
 320         int fd, ret = -1;
 321         unsigned int seed;
 322         size_t len = sizeof(unsigned int);
 323
 324         fd = open("/dev/urandom", O_RDONLY);
 325         if (fd < 0)
 326                 goto out;
 327         ret = -2;
 328         if (read(fd, &seed, len) != len)
 329                 goto out;
 330         srandom(seed);
 331         ret = 1;
 332 out:
 333         if (fd >= 0)
 334                 close(fd);
 335         if (ret > 0)
 336                 return;
 337         PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
 338                 ret);
 339         exit(EXIT_FAILURE);
 340 }
 341
 342 uint32_t afs_socket_cookie;
 343 int afs_socket;
 344 static pid_t afs_pid;
 345
 346 static void init_afs(void)
 347 {
 348         int ret, afs_server_socket[2];
 349
 350         ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
 351         if (ret < 0)
 352                 exit(EXIT_FAILURE);
 353         afs_socket_cookie = para_random((uint32_t)-1);
 354         afs_pid = fork();
 355         if (afs_pid < 0)
 356                 exit(EXIT_FAILURE);
 357         if (!afs_pid) { /* child (afs) */
 358                 close(afs_server_socket[0]);
 359                 afs_init(afs_socket_cookie, afs_server_socket[1]);
 360         }
 361         close(afs_server_socket[1]);
 362         afs_socket = afs_server_socket[0];
 363         ret = mark_fd_nonblock(afs_socket);
 364         if (ret < 0)
 365                 exit(EXIT_FAILURE);
 366         add_close_on_fork_list(afs_socket);
 367         PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n", afs_socket,
 368                 (unsigned) afs_socket_cookie);
 369 }
 370
 371
 372 static unsigned do_inits(int argc, char **argv)
 373 {
 374         /* connector's address information */
 375         int sockfd;
 376
 377         init_random_seed();
 378         /* parse command line options */
 379         server_cmdline_parser(argc, argv, &conf);
 380         HANDLE_VERSION_FLAG("server", conf);
 381         para_drop_privileges(conf.user_arg, conf.group_arg);
 382         /* parse config file, open log and set defaults */
 383         parse_config(0);
 384         log_welcome("para_server", conf.loglevel_arg);
 385         shm_init(); /* init mmd struct */
 386         server_uptime(UPTIME_SET); /* reset server uptime */
 387         init_user_list(user_list_file);
 388         /* become daemon */
 389         if (conf.daemon_given)
 390                 daemon_init();
 391         PARA_NOTICE_LOG("%s", "initializing virtual streaming system\n");
 392         afh_init();
 393         vss_init();
 394         mmd->server_pid = getpid();
 395         setup_signal_handling();
 396         init_afs();
 397         mmd_lock();
 398         /* init network socket */
 399         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 400         sockfd = init_network();
 401         PARA_NOTICE_LOG("%s", "init complete\n");
 402         return sockfd;
 403 }
 404
 405 /*
 406  * called when server gets SIGHUP or when client invokes hup command.
 407  */
 408 static void handle_sighup(void)
 409 {
 410         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 411         close_log(logfile); /* gets reopened if necessary by parse_config */
 412         logfile = NULL;
 413         parse_config(1); /* reopens log */
 414         init_user_list(user_list_file); /* reload user list */
 415         if (afs_pid)
 416                 kill(afs_pid, SIGHUP);
 417 }
 418
 419 static void status_refresh(void)
 420 {
 421         static int prev_uptime = -1, prev_events = -1;
 422         int uptime = server_uptime(UPTIME_GET), ret = 1;
 423
 424         if (prev_events != mmd->events)
 425                 goto out;
 426         if (mmd->new_vss_status_flags != mmd->vss_status_flags)
 427                 goto out;
 428         if (uptime / 60 != prev_uptime / 60)
 429                 goto out;
 430         ret = 0;
 431 out:
 432         prev_uptime = uptime;
 433         prev_events = mmd->events;
 434         mmd->vss_status_flags = mmd->new_vss_status_flags;
 435         if (ret) {
 436                 PARA_DEBUG_LOG("%d events, forcing status update\n",
 437                         mmd->events);
 438                 killpg(0, SIGUSR1);
 439         }
 440 }
 441
 442 /**
 443  * the main function of para_server
 444  *
 445  * \param argc usual argument count
 446  * \param argv usual argument vector
 447  *
 448  * \return EXIT_SUCCESS or EXIT_FAILURE
 449  *
 450  */
 451 int main(int argc, char *argv[])
 452 {
 453         /* listen on sock_fd, new connection on new_fd */
 454         int sockfd, new_fd;
 455         struct sockaddr_in their_addr;
 456         int i, max_fileno, ret;
 457         pid_t chld_pid;
 458         fd_set rfds, wfds;
 459         struct timeval *timeout;
 460
 461         valid_fd_012();
 462         sockfd = do_inits(argc, argv);
 463 repeat:
 464         FD_ZERO(&rfds);
 465         FD_ZERO(&wfds);
 466         max_fileno = -1;
 467         /* check socket and signal pipe in any case */
 468         para_fd_set(sockfd, &rfds, &max_fileno);
 469         para_fd_set(signal_pipe, &rfds, &max_fileno);
 470         timeout = vss_preselect(&rfds, &wfds, &max_fileno);
 471         status_refresh();
 472         for (i = 0; senders[i].name; i++) {
 473                 if (senders[i].status != SENDER_ON)
 474                         continue;
 475                 if (!senders[i].pre_select)
 476                         continue;
 477                 senders[i].pre_select(&max_fileno, &rfds, &wfds);
 478         }
 479         mmd_unlock();
 480         ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
 481         mmd_lock();
 482         vss_post_select(&rfds, &wfds);
 483         if (ret < 0)
 484                 goto repeat;
 485         for (i = 0; senders[i].name; i++) {
 486                 if (senders[i].status != SENDER_ON)
 487                         continue;
 488                 if (!senders[i].post_select)
 489                         continue;
 490                 senders[i].post_select(&rfds, &wfds);
 491         }
 492         vss_send_chunk();
 493         status_refresh();
 494         if (FD_ISSET(signal_pipe, &rfds)) {
 495                 int sig;
 496                 pid_t pid;
 497                 sig = para_next_signal();
 498                 switch (sig) {
 499                 case SIGHUP:
 500                         handle_sighup();
 501                         break;
 502                 case SIGCHLD:
 503                         for (;;) {
 504                                 ret = para_reap_child(&pid);
 505                                 if (ret <= 0)
 506                                         break;
 507                                 if (pid != afs_pid)
 508                                         continue;
 509                                 PARA_EMERG_LOG("fatal: afs died\n");
 510                                 goto genocide;
 511                         }
 512                         break;
 513                 /* die on sigint/sigterm. Kill all children too. */
 514                 case SIGINT:
 515                 case SIGTERM:
 516                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 517 genocide:
 518                         kill(0, SIGTERM);
 519                         mutex_destroy(mmd_mutex);
 520                         shm_detach(mmd);
 521                         shm_destroy(mmd_shm_id);
 522
 523                         exit(EXIT_FAILURE);
 524                 }
 525         }
 526         if (mmd->sender_cmd_data.cmd_num >= 0) {
 527                 int num = mmd->sender_cmd_data.cmd_num,
 528                         s = mmd->sender_cmd_data.sender_num;
 529
 530                 if (senders[s].client_cmds[num])
 531                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 532                 mmd->sender_cmd_data.cmd_num = -1;
 533         }
 534         if (!FD_ISSET(sockfd, &rfds))
 535                 goto repeat;
 536
 537         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 538         if (new_fd < 0)
 539                 goto repeat;
 540         PARA_INFO_LOG("got connection from %s, forking\n",
 541                 inet_ntoa(their_addr.sin_addr));
 542         mmd->num_connects++;
 543         mmd->active_connections++;
 544         random();
 545         chld_pid = fork();
 546         if (chld_pid < 0) {
 547                 PARA_CRIT_LOG("%s", "fork failed\n");
 548                 goto repeat;
 549         }
 550         if (chld_pid) {
 551                 close(new_fd);
 552                 /* parent keeps accepting connections */
 553                 goto repeat;
 554         }
 555         alarm(ALARM_TIMEOUT);
 556         close_listed_fds();
 557         close(sockfd); /* child doesn't need the listener */
 558         /*
 559          * put info on who we are serving into argv[0] to make
 560          * client ip visible in top/ps
 561          */
 562         for (i = argc - 1; i >= 0; i--)
 563                 memset(argv[i], 0, strlen(argv[i]));
 564         sprintf(argv[0], "para_server (serving %s)",
 565                 inet_ntoa(their_addr.sin_addr));
 566         return handle_connect(new_fd, &their_addr);
 567 }