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