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 <signal.h>
  19 #include <sys/types.h>
  20 #include <dirent.h>
  21
  22 #include "para.h"
  23 #include "server.cmdline.h"
  24 #include "afs_common.h"
  25 #include "afh.h"
  26 #include "server.h"
  27 #include "vss.h"
  28 #include "config.h"
  29 #include "close_on_fork.h"
  30 #include "send.h"
  31 #include "error.h"
  32 #include "net.h"
  33 #include "daemon.h"
  34 #include "string.h"
  35 #include "ipc.h"
  36 #include "fd.h"
  37 #include "list.h"
  38 #include "sched.h"
  39 #include "signal.h"
  40 #include "user_list.h"
  41 #include "afs.h"
  42
  43 /** define the array of error lists needed by para_server */
  44 INIT_SERVER_ERRLISTS;
  45
  46 /** shut down non-authorized connections after that many seconds */
  47 #define ALARM_TIMEOUT 10
  48
  49 /**
  50  * pointer to shared memory area for communication between para_server
  51  * and its children. exported to vss.c. command.c and to all selectors.
  52  */
  53 struct misc_meta_data *mmd;
  54
  55 /**
  56  * the configuration of para_server
  57  *
  58  * It also contains the options for all audio file selectors, audio format handler
  59  * and all supported senders.
  60  */
  61 struct server_args_info conf;
  62
  63 /** the file containing user information (public key, permissions) */
  64 char *user_list_file = NULL;
  65
  66 extern void dccp_send_init(struct sender *);
  67 extern void http_send_init(struct sender *);
  68 extern void ortp_send_init(struct sender *);
  69
  70 /* TODO: This is better handled by autoconf */
  71 /** the list of supported audio file selectors */
  72 struct audio_file_selector selectors[] = {
  73         {
  74                 .name = "random",
  75                 .init = random_selector_init,
  76                 .update_audio_file = NULL,
  77         },
  78         {
  79                 .name = "playlist",
  80                 .init = playlist_selector_init,
  81                 .update_audio_file = NULL,
  82                 .pre_select = NULL,
  83                 .post_select = NULL,
  84         },
  85 #ifdef HAVE_MYSQL
  86         {
  87                 .name = "mysql",
  88                 .init = mysql_selector_init,
  89                 .update_audio_file = NULL,
  90                 .pre_select = NULL,
  91                 .post_select = NULL,
  92         },
  93 #endif
  94         {
  95                 .name = NULL,
  96         }
  97 };
  98
  99 /** the list of supported senders */
 100 struct sender senders[] = {
 101         {
 102                 .name = "http",
 103                 .init = http_send_init,
 104         },
 105         {
 106                 .name = "dccp",
 107                 .init = dccp_send_init,
 108         },
 109 #ifdef HAVE_ORTP
 110         {
 111                 .name = "ortp",
 112                 .init = ortp_send_init,
 113         },
 114 #endif
 115         {
 116                 .name = NULL,
 117         }
 118 };
 119
 120
 121 /* global variables for server-internal use */
 122 static FILE *logfile;
 123 static int mmd_mutex, mmd_shm_id;
 124 static int signal_pipe;
 125
 126 /**
 127  * para_server's log function
 128  *
 129  * \param ll the log level
 130  * \param fmt the format string describing the log message
 131  */
 132 void para_log(int ll, const char* fmt,...)
 133 {
 134         va_list argp;
 135         FILE *outfd;
 136         struct tm *tm;
 137         time_t t1;
 138         char str[MAXLINE] = "";
 139         pid_t mypid;
 140
 141         if (ll < conf.loglevel_arg)
 142                 return;
 143         outfd = logfile? logfile : stderr;
 144         time(&t1);
 145         tm = localtime(&t1);
 146         strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
 147         fprintf(outfd, "%s ", str);
 148         if (conf.loglevel_arg <= INFO)
 149                 fprintf(outfd, "%i: ", ll);
 150         mypid = getpid();
 151         if (conf.loglevel_arg <= INFO)
 152                 fprintf(outfd, "(%d) ", mypid);
 153         va_start(argp, fmt);
 154         vfprintf(outfd, fmt, argp);
 155         va_end(argp);
 156 }
 157
 158 /*
 159  * setup shared memory area and get mutex for locking
 160  */
 161 static void shm_init(void)
 162 {
 163         void *shm;
 164         int ret = shm_new(sizeof(struct misc_meta_data));
 165
 166         if (ret < 0)
 167                 goto err_out;
 168
 169         ret = shm_attach(ret, ATTACH_RW, &shm);
 170         if (ret < 0)
 171                 goto err_out;
 172         mmd = shm;
 173         mmd_shm_id = ret;
 174
 175         ret = mutex_new();
 176         if (ret < 0)
 177                 goto err_out;
 178         mmd_mutex = ret;
 179
 180         mmd->selector_num = 0;
 181         mmd->num_played = 0;
 182         mmd->num_commands = 0;
 183         mmd->events = 0;
 184         mmd->num_connects = 0;
 185         mmd->active_connections = 0;
 186         strcpy(mmd->filename, "(none)");
 187         mmd->audio_format = -1;
 188         mmd->vss_status_flags = VSS_NEXT;
 189         mmd->new_vss_status_flags = VSS_NEXT;
 190         mmd->sender_cmd_data.cmd_num = -1;
 191         return;
 192 err_out:
 193         PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
 194         exit(EXIT_FAILURE);
 195 }
 196
 197 /**
 198  * lock the shared memory area containing the mmd struct
 199  *
 200  * \sa semop(2), struct misc_meta_data
 201  */
 202 void mmd_lock(void)
 203 {
 204         mutex_lock(mmd_mutex);
 205 }
 206
 207 /**
 208  * unlock the shared memory area containing the mmd struct
 209  *
 210  * \sa semop(2), struct misc_meta_data
 211  */
 212
 213 void mmd_unlock(void)
 214 {
 215         mutex_unlock(mmd_mutex);
 216 }
 217
 218 static void parse_config(int override)
 219 {
 220         char *home = para_homedir();
 221         struct stat statbuf;
 222         int ret;
 223         char *cf;
 224
 225         if (conf.config_file_given)
 226                 cf = conf.config_file_arg;
 227         else
 228                 cf = make_message("%s/.paraslash/server.conf", home);
 229         free(user_list_file);
 230         if (!conf.user_list_given)
 231                 user_list_file = make_message("%s/.paraslash/server.users", home);
 232         else
 233                 user_list_file = para_strdup(conf.user_list_arg);
 234         ret = stat(cf, &statbuf);
 235         if (ret && conf.config_file_given) {
 236                 ret = -1;
 237                 PARA_EMERG_LOG("can not stat config file %s\n", cf);
 238                 goto out;
 239         }
 240         if (!ret) {
 241                 int tmp = conf.daemon_given;
 242                 struct server_cmdline_parser_params params = {
 243                         .override = override,
 244                         .initialize = 0,
 245                         .check_required = 0,
 246                         .check_ambiguity = 0
 247                 };
 248                 server_cmdline_parser_config_file(cf, &conf, &params);
 249                 conf.daemon_given = tmp;
 250         }
 251         /* logfile */
 252         if (!conf.logfile_given && conf.daemon_given) {
 253                 ret = -1;
 254                 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
 255                 goto out;
 256         }
 257         if (conf.logfile_given)
 258                 logfile = open_log(conf.logfile_arg);
 259         ret = 1;
 260 out:
 261         free(cf);
 262         free(home);
 263         if (ret > 0)
 264                 return;
 265         free(user_list_file);
 266         user_list_file = NULL;
 267         exit(EXIT_FAILURE);
 268 }
 269
 270 static void setup_signal_handling(void)
 271 {
 272         int ret = 0;
 273
 274         signal_pipe = para_signal_init();
 275         PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
 276         ret += para_install_sighandler(SIGINT);
 277         ret += para_install_sighandler(SIGTERM);
 278         ret += para_install_sighandler(SIGHUP);
 279         ret += para_install_sighandler(SIGCHLD);
 280         ret += para_install_sighandler(SIGUSR1);
 281         signal(SIGPIPE, SIG_IGN);
 282         if (ret != 5) {
 283                 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
 284                 exit(EXIT_FAILURE);
 285         }
 286 }
 287
 288 static void init_selector(void)
 289 {
 290         int i, ret;
 291
 292         mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
 293         if (!conf.selector_given)
 294                 goto random;
 295         for (i = 0; selectors[i].name; i++) {
 296                 if (strcmp(selectors[i].name, conf.selector_arg))
 297                         continue;
 298                 PARA_NOTICE_LOG("initializing %s audio file selector\n",
 299                         selectors[i].name);
 300                 ret = selectors[i].init(&selectors[i]);
 301                 if (ret < 0) {
 302                         PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
 303                         break;
 304                 }
 305                 mmd->selector_num = i;
 306                 return;
 307         }
 308         PARA_WARNING_LOG("%s", "falling back to the random selector\n");
 309 random:
 310         mmd->selector_num = 0;
 311         selectors[0].init(&selectors[0]); /* always successful */
 312 }
 313
 314 static unsigned init_network(void)
 315 {
 316         int fd, ret = init_tcp_socket(conf.port_arg);
 317
 318         if (ret < 0)
 319                 goto err;
 320         fd = ret;
 321         ret = mark_fd_nonblock(fd);
 322         if (ret < 0)
 323                 goto err;
 324         return fd;
 325 err:
 326         PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
 327         exit(EXIT_FAILURE);
 328 }
 329
 330 static void init_random_seed(void)
 331 {
 332         int fd, ret = -1;
 333         unsigned int seed;
 334         size_t len = sizeof(unsigned int);
 335
 336         fd = open("/dev/urandom", O_RDONLY);
 337         if (fd < 0)
 338                 goto out;
 339         ret = -2;
 340         if (read(fd, &seed, len) != len)
 341                 goto out;
 342         srandom(seed);
 343         ret = 1;
 344 out:
 345         if (fd >= 0)
 346                 close(fd);
 347         if (ret > 0)
 348                 return;
 349         PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
 350                 ret);
 351         exit(EXIT_FAILURE);
 352 }
 353
 354 uint32_t afs_socket_cookie;
 355 static int afs_socket;
 356 static pid_t afs_pid;
 357
 358 static void init_afs(void)
 359 {
 360         int ret, afs_server_socket[2];
 361
 362         ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
 363         if (ret < 0)
 364                 exit(EXIT_FAILURE);
 365         afs_socket_cookie = para_random((uint32_t)-1);
 366         afs_pid = fork();
 367         if (afs_pid < 0)
 368                 exit(EXIT_FAILURE);
 369         if (!afs_pid) { /* child (afs) */
 370                 close(afs_server_socket[0]);
 371                 afs_init(afs_socket_cookie, afs_server_socket[1]);
 372         }
 373         close(afs_server_socket[1]);
 374         afs_socket = afs_server_socket[0];
 375         ret = mark_fd_nonblock(afs_socket);
 376         if (ret < 0)
 377                 exit(EXIT_FAILURE);
 378         add_close_on_fork_list(afs_socket);
 379         PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n", afs_socket,
 380                 (unsigned) afs_socket_cookie);
 381 }
 382
 383
 384 static unsigned do_inits(int argc, char **argv)
 385 {
 386         /* connector's address information */
 387         int sockfd;
 388
 389         init_random_seed();
 390         /* parse command line options */
 391         server_cmdline_parser(argc, argv, &conf);
 392         HANDLE_VERSION_FLAG("server", conf);
 393         para_drop_privileges(conf.user_arg, conf.group_arg);
 394         /* parse config file, open log and set defaults */
 395         parse_config(0);
 396         log_welcome("para_server", conf.loglevel_arg);
 397         shm_init(); /* init mmd struct */
 398         server_uptime(UPTIME_SET); /* reset server uptime */
 399         init_user_list(user_list_file);
 400         /* become daemon */
 401         if (conf.daemon_given)
 402                 daemon_init();
 403         init_selector();
 404 //      PARA_ERROR_LOG("num: %d\n", mmd->selector_num);
 405         PARA_NOTICE_LOG("%s", "initializing virtual streaming system\n");
 406         vss_init();
 407         mmd->server_pid = getpid();
 408         setup_signal_handling();
 409         init_afs();
 410         mmd_lock();
 411         /* init network socket */
 412         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 413         sockfd = init_network();
 414         PARA_NOTICE_LOG("%s", "init complete\n");
 415         return sockfd;
 416 }
 417
 418 static void change_selector(void)
 419 {
 420         int ret, old = mmd->selector_num, new = mmd->selector_change;
 421
 422         selectors[old].shutdown();
 423         ret = selectors[new].init(&selectors[new]);
 424         mmd->selector_change = -1; /* reset */
 425         if (ret >= 0) {
 426                 mmd->selector_num = new;
 427                 return;
 428         }
 429         /* init failed */
 430         PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
 431         selectors[0].init(&selectors[0]);
 432         mmd->selector_num = 0;
 433 }
 434
 435 /*
 436  * called when server gets SIGHUP or when client invokes hup command.
 437  */
 438 static void handle_sighup(void)
 439 {
 440         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 441         close_log(logfile); /* gets reopened if necessary by parse_config */
 442         logfile = NULL;
 443         parse_config(1); /* reopens log */
 444         mmd->selector_change = mmd->selector_num; /* do not change selector.. */
 445         change_selector(); /* .. just reload */
 446         init_user_list(user_list_file); /* reload user list */
 447         if (afs_pid)
 448                 kill(afs_pid, SIGHUP);
 449 }
 450
 451 static void status_refresh(void)
 452 {
 453         static int prev_uptime = -1, prev_events = -1;
 454         int uptime = server_uptime(UPTIME_GET), ret = 1;
 455
 456         if (prev_events != mmd->events)
 457                 goto out;
 458         if (mmd->new_vss_status_flags != mmd->vss_status_flags)
 459                 goto out;
 460         if (uptime / 60 != prev_uptime / 60)
 461                 goto out;
 462         ret = 0;
 463 out:
 464         prev_uptime = uptime;
 465         prev_events = mmd->events;
 466         mmd->vss_status_flags = mmd->new_vss_status_flags;
 467         if (ret) {
 468                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 469                         mmd->events, mmd->audio_format);
 470                 killpg(0, SIGUSR1);
 471         }
 472 }
 473
 474 /**
 475  * the main function of para_server
 476  *
 477  * \param argc usual argument count
 478  * \param argv usual argument vector
 479  *
 480  * \return EXIT_SUCCESS or EXIT_FAILURE
 481  *
 482  */
 483 int main(int argc, char *argv[])
 484 {
 485         /* listen on sock_fd, new connection on new_fd */
 486         int sockfd, new_fd;
 487         struct sockaddr_in their_addr;
 488         int i, max_fileno, ret;
 489         pid_t chld_pid;
 490         fd_set rfds, wfds;
 491         struct timeval *timeout;
 492
 493         valid_fd_012();
 494         sockfd = do_inits(argc, argv);
 495 repeat:
 496         FD_ZERO(&rfds);
 497         FD_ZERO(&wfds);
 498         max_fileno = -1;
 499         /* check socket and signal pipe in any case */
 500         para_fd_set(sockfd, &rfds, &max_fileno);
 501         para_fd_set(signal_pipe, &rfds, &max_fileno);
 502         timeout = vss_preselect();
 503         status_refresh();
 504         for (i = 0; senders[i].name; i++) {
 505                 if (senders[i].status != SENDER_ON)
 506                         continue;
 507                 if (!senders[i].pre_select)
 508                         continue;
 509                 senders[i].pre_select( &max_fileno, &rfds, &wfds);
 510         }
 511         if (selectors[mmd->selector_num].pre_select) {
 512                 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
 513                 max_fileno = PARA_MAX(max_fileno, ret);
 514         }
 515         mmd_unlock();
 516         ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
 517         mmd_lock();
 518         if (mmd->selector_change >= 0)
 519                 change_selector();
 520         if (selectors[mmd->selector_num].post_select)
 521                 selectors[mmd->selector_num].post_select(&rfds, &wfds);
 522         if (ret < 0)
 523                 goto repeat;
 524         for (i = 0; senders[i].name; i++) {
 525                 if (senders[i].status != SENDER_ON)
 526                         continue;
 527                 if (!senders[i].post_select)
 528                         continue;
 529                 senders[i].post_select(&rfds, &wfds);
 530         }
 531         vss_send_chunk();
 532         status_refresh();
 533         if (FD_ISSET(signal_pipe, &rfds)) {
 534                 int sig;
 535                 pid_t pid;
 536                 sig = para_next_signal();
 537                 switch (sig) {
 538                 case SIGHUP:
 539                         handle_sighup();
 540                         break;
 541                 case SIGCHLD:
 542                         for (;;) {
 543                                 ret = para_reap_child(&pid);
 544                                 if (ret <= 0)
 545                                         break;
 546                                 if (pid != afs_pid)
 547                                         continue;
 548                                 PARA_EMERG_LOG("fatal: afs died\n");
 549                                 goto genocide;
 550                         }
 551                         break;
 552                 /* die on sigint/sigterm. Kill all children too. */
 553                 case SIGINT:
 554                 case SIGTERM:
 555                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 556 genocide:
 557                         kill(0, SIGTERM);
 558                         selectors[mmd->selector_num].shutdown();
 559                         mutex_destroy(mmd_mutex);
 560                         shm_detach(mmd);
 561                         shm_destroy(mmd_shm_id);
 562
 563                         exit(EXIT_FAILURE);
 564                 }
 565         }
 566         if (mmd->sender_cmd_data.cmd_num >= 0) {
 567                 int num = mmd->sender_cmd_data.cmd_num,
 568                         s = mmd->sender_cmd_data.sender_num;
 569
 570                 if (senders[s].client_cmds[num])
 571                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 572                 mmd->sender_cmd_data.cmd_num = -1;
 573         }
 574         if (!FD_ISSET(sockfd, &rfds))
 575                 goto repeat;
 576
 577         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 578         if (new_fd < 0)
 579                 goto repeat;
 580         PARA_INFO_LOG("got connection from %s, forking\n",
 581                 inet_ntoa(their_addr.sin_addr));
 582         mmd->num_connects++;
 583         mmd->active_connections++;
 584         random();
 585         chld_pid = fork();
 586         if (chld_pid < 0) {
 587                 PARA_CRIT_LOG("%s", "fork failed\n");
 588                 goto repeat;
 589         }
 590         if (chld_pid) {
 591                 close(new_fd);
 592                 /* parent keeps accepting connections */
 593                 goto repeat;
 594         }
 595         alarm(ALARM_TIMEOUT);
 596         close_listed_fds();
 597         close(sockfd); /* child doesn't need the listener */
 598         /*
 599          * put info on who we are serving into argv[0] to make
 600          * client ip visible in top/ps
 601          */
 602         for (i = argc - 1; i >= 0; i--)
 603                 memset(argv[i], 0, strlen(argv[i]));
 604         sprintf(argv[0], "para_server (serving %s)",
 605                 inet_ntoa(their_addr.sin_addr));
 606         return handle_connect(new_fd, &their_addr);
 607 }