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