server.c

   1 /*
   2  * Copyright (C) 1997-2006 Andre Noll <maan@systemlinux.org>
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     This program is distributed in the hope that it will be useful,
  10  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *     GNU General Public License for more details.
  13  *
  14  *     You should have received a copy of the GNU General Public License
  15  *     along with this program; if not, write to the Free Software
  16  *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  17  */
  18
  19 /** \file server.c Paraslash's main server */
  20
  21
  22 /** \mainpage Paraslash API Reference
  23  *
  24  *  Good starting points for reading are probably \ref audio_file_selector,
  25  *  \ref sender, \ref receiver, \ref receiver_node, \ref filter, \ref
  26  *  filter_node.
  27  *
  28  */
  29
  30
  31
  32 #include "server.cmdline.h"
  33 #include "db.h"
  34 #include "server.h"
  35 #include "afs.h"
  36 #include "config.h"
  37 #include "close_on_fork.h"
  38 #include "send.h"
  39 #include "error.h"
  40 #include "net.h"
  41 #include "daemon.h"
  42 #include "string.h"
  43 #include "ipc.h"
  44 #include "fd.h"
  45 #include "crypt.h"
  46
  47 /** define the array of error lists needed by para_server */
  48 INIT_SERVER_ERRLISTS;
  49
  50 /** shut down non-authorized connections after that many seconds */
  51 #define ALARM_TIMEOUT 10
  52
  53 /* these are exported to afs.c. command.c and to all selectors */
  54 struct misc_meta_data *mmd;
  55 /** the configuration of para_server
  56  *
  57  * It also contains the options for all audio file selectors and all supported
  58  * senders.
  59 */
  60 struct server_args_info conf;
  61 char *user_list = NULL;
  62 struct list_head _user_list;
  63 extern void dccp_send_init(struct sender *);
  64 extern void http_send_init(struct sender *);
  65 extern void ortp_send_init(struct sender *);
  66
  67 /* TODO: This is better handled by autoconf */
  68 /** the list of supported audio file selectors */
  69 struct audio_file_selector selectors[] = {
  70         {
  71                 .name = "random",
  72                 .init = random_selector_init,
  73                 .update_audio_file = NULL,
  74         },
  75         {
  76                 .name = "playlist",
  77                 .init = playlist_selector_init,
  78                 .update_audio_file = NULL,
  79                 .pre_select = NULL,
  80                 .post_select = NULL,
  81         },
  82 #ifdef HAVE_MYSQL
  83         {
  84                 .name = "mysql",
  85                 .init = mysql_selector_init,
  86                 .update_audio_file = NULL,
  87                 .pre_select = NULL,
  88                 .post_select = NULL,
  89         },
  90 #endif
  91         {
  92                 .name = NULL,
  93         }
  94 };
  95
  96 /** the list of supported senders */
  97 struct sender senders[] = {
  98         {
  99                 .name = "http",
 100                 .init = http_send_init,
 101         },
 102         {
 103                 .name = "dccp",
 104                 .init = dccp_send_init,
 105         },
 106 #ifdef HAVE_ORTP
 107         {
 108                 .name = "ortp",
 109                 .init = ortp_send_init,
 110         },
 111 #endif
 112         {
 113                 .name = NULL,
 114         }
 115 };
 116
 117
 118 /* global variables for server-internal use */
 119 static FILE *logfile;
 120 static int mmd_mutex, mmd_shm_id;
 121 static int signal_pipe;
 122
 123 /**
 124  * para_server's log function
 125  *
 126  * \param ll the log level
 127  * \param fmt the format string describing the log message
 128  */
 129 void para_log(int ll, const char* fmt,...)
 130 {
 131         va_list argp;
 132         FILE *outfd;
 133         struct tm *tm;
 134         time_t t1;
 135         char str[MAXLINE] = "";
 136         pid_t mypid;
 137
 138         if (ll < conf.loglevel_arg)
 139                 return;
 140         outfd = logfile? logfile : stderr;
 141         time(&t1);
 142         tm = localtime(&t1);
 143         strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
 144         fprintf(outfd, "%s ", str);
 145         if (conf.loglevel_arg <= INFO)
 146                 fprintf(outfd, "%i: ", ll);
 147         mypid = getpid();
 148         if (conf.loglevel_arg <= INFO)
 149                 fprintf(outfd, "(%d) ", mypid);
 150         va_start(argp, fmt);
 151         vfprintf(outfd, fmt, argp);
 152         va_end(argp);
 153 }
 154
 155 /*
 156  * setup shared memory area and get mutex for locking
 157  */
 158 static void shm_init(void)
 159 {
 160         void *shm;
 161         int ret = shm_new(sizeof(struct misc_meta_data));
 162
 163         if (ret < 0)
 164                 goto err_out;
 165
 166         ret = shm_attach(ret, ATTACH_RW, &shm);
 167         if (ret < 0)
 168                 goto err_out;
 169         mmd = shm;
 170         mmd_shm_id = ret;
 171
 172         ret = mutex_new();
 173         if (ret < 0)
 174                 goto err_out;
 175         mmd_mutex = ret;
 176
 177         mmd->selector_num = 0;
 178         mmd->num_played = 0;
 179         mmd->num_commands = 0;
 180         mmd->events = 0;
 181         mmd->num_connects = 0;
 182         mmd->active_connections = 0;
 183         strcpy(mmd->filename, "(none)");
 184         mmd->audio_format = -1;
 185         mmd->afs_status_flags = AFS_NEXT;
 186         mmd->new_afs_status_flags = AFS_NEXT;
 187         mmd->sender_cmd_data.cmd_num = -1;
 188         return;
 189 err_out:
 190         PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
 191         exit(EXIT_FAILURE);
 192 }
 193
 194 /**
 195  * lock the shared memory area containing the mmd struct
 196  *
 197  * \sa semop(2), struct misc_meta_data
 198  */
 199 void mmd_lock(void)
 200 {
 201         mutex_lock(mmd_mutex);
 202 }
 203
 204 /**
 205  * unlock the shared memory area containing the mmd struct
 206  *
 207  * \sa semop(2), struct misc_meta_data
 208  */
 209
 210 void mmd_unlock(void)
 211 {
 212         mutex_unlock(mmd_mutex);
 213 }
 214
 215 static void parse_config(int override)
 216 {
 217         char *home = para_homedir();
 218         struct stat statbuf;
 219         int ret;
 220         char *cf;
 221
 222         if (conf.config_file_given)
 223                 cf = conf.config_file_arg;
 224         else
 225                 cf = make_message("%s/.paraslash/server.conf", home);
 226         free(user_list);
 227         if (!conf.user_list_given)
 228                 user_list = make_message("%s/.paraslash/server.users", home);
 229         else
 230                 user_list = para_strdup(conf.user_list_arg);
 231         ret = stat(cf, &statbuf);
 232         if (ret && conf.config_file_given) {
 233                 ret = -1;
 234                 PARA_EMERG_LOG("can not stat config file %s\n", cf);
 235                 goto out;
 236         }
 237         if (!ret) {
 238                 int tmp = conf.daemon_given;
 239                 server_cmdline_parser_configfile(cf, &conf, override, 0, 0);
 240                 conf.daemon_given = tmp;
 241         }
 242         /* logfile */
 243         if (!conf.logfile_given && conf.daemon_given) {
 244                 ret = -1;
 245                 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
 246                 goto out;
 247         }
 248         if (conf.logfile_given)
 249                 logfile = open_log(conf.logfile_arg);
 250         ret = 1;
 251 out:
 252         free(cf);
 253         free(home);
 254         if (ret > 0)
 255                 return;
 256         free(user_list);
 257         user_list = NULL;
 258         exit(EXIT_FAILURE);
 259 }
 260
 261 static void setup_signal_handling(void)
 262 {
 263         int ret = 0;
 264
 265         signal_pipe = para_signal_init();
 266         PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
 267         ret += para_install_sighandler(SIGINT);
 268         ret += para_install_sighandler(SIGTERM);
 269         ret += para_install_sighandler(SIGHUP);
 270         ret += para_install_sighandler(SIGCHLD);
 271         ret += para_install_sighandler(SIGUSR1);
 272         signal(SIGPIPE, SIG_IGN);
 273         if (ret != 5) {
 274                 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
 275                 exit(EXIT_FAILURE);
 276         }
 277 }
 278
 279 /*
 280  * lookup user in user_list file. Fills in a user struct containing
 281  * filename of the user's public key as well as the permissions of that user.
 282  * Returns 1 on success, 0 if user does not exist and < 0 on errors.
 283  */
 284 static void populate_user_list(void) {
 285         FILE *file_ptr = NULL;
 286         char *char_ptr;
 287         char line[MAXLINE];
 288         /* keyword, user, key, perms */
 289         char w[MAXLINE], n[MAXLINE], k[MAXLINE], p[MAXLINE], tmp[4][MAXLINE];
 290         int num, ret;
 291
 292         file_ptr = fopen(user_list, "r");
 293         ret = -E_USERLIST;
 294         if (!file_ptr)
 295                 goto out;
 296         for (;;) {
 297                 struct _user *u;
 298                 ret = para_fgets(line, MAXLINE, file_ptr);
 299                 if (ret < 0)
 300                         PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
 301                 if (ret <= 0)
 302                         break;
 303                 if (sscanf(line,"%200s %200s %200s %200s", w, n, k, p) < 3)
 304                         continue;
 305                 if (strcmp(w, "user"))
 306                         continue;
 307                 PARA_DEBUG_LOG("found entry for %s\n", n);
 308                 u = para_malloc(sizeof(struct _user));
 309                 u->name = para_strdup(n);
 310                 u->rsa = para_malloc(sizeof(RSA));
 311                 ret = get_rsa_key(k, &u->rsa, 0 /* public */);
 312                 if (ret < 0)
 313                         break;
 314                 u->perms = 0;
 315                 char_ptr = p;
 316                 num = sscanf(char_ptr, "%200[A-Z_],%200[A-Z_],%200[A-Z_],%200[A-Z_]",
 317                         tmp[0], tmp[1], tmp[2], tmp[3]);
 318                 PARA_DEBUG_LOG("found %i perm entries\n", num);
 319                 u->perms = 0;
 320                 while (num > 0) {
 321                         num--;
 322                         if (!strcmp(tmp[num], "AFS_READ"))
 323                                 u->perms |= AFS_READ;
 324                         else if (!strcmp(tmp[num], "AFS_WRITE"))
 325                                 u->perms |= AFS_WRITE;
 326                         else if (!strcmp(tmp[num], "DB_READ"))
 327                                 u->perms |= DB_READ;
 328                         else if (!strcmp(tmp[num], "DB_WRITE"))
 329                                 u->perms |= DB_WRITE;
 330                         else /* unknown permission */
 331                                 PARA_WARNING_LOG("unknown permission: %s\n",
 332                                         tmp[num]);
 333                 }
 334                 para_list_add(&u->node, &_user_list);
 335         }
 336 out:
 337         if (file_ptr)
 338                 fclose(file_ptr);
 339         if (ret >= 0)
 340                 return;
 341         PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
 342         exit(EXIT_FAILURE);
 343 }
 344
 345 static void init_user_list(void)
 346 {
 347         struct _user *u, *tmp;
 348         static int initialized;
 349
 350         if (initialized) {
 351                 list_for_each_entry_safe(u, tmp, &_user_list, node) {
 352                         list_del(&u->node);
 353                         free(u->name);
 354                         free(u->rsa);
 355                         free(u);
 356                 }
 357         } else
 358                 INIT_LIST_HEAD(&_user_list);
 359         initialized = 1;
 360         populate_user_list();
 361 }
 362
 363 int _get_user(struct _user *user)
 364 {
 365         struct _user *u;
 366         list_for_each_entry(u, &_user_list, node) {
 367                 if (strcmp(u->name, user->name))
 368                         continue;
 369                 *user = *u;
 370                 return 1;
 371         }
 372         return 0;
 373 }
 374
 375 static void init_selector(void)
 376 {
 377         int i, ret;
 378
 379         mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
 380         if (!conf.selector_given)
 381                 goto random;
 382         for (i = 0; selectors[i].name; i++) {
 383                 if (strcmp(selectors[i].name, conf.selector_arg))
 384                         continue;
 385                 PARA_NOTICE_LOG("initializing %s audio file selector\n",
 386                         selectors[i].name);
 387                 ret = selectors[i].init(&selectors[i]);
 388                 if (ret < 0) {
 389                         PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
 390                         break;
 391                 }
 392                 mmd->selector_num = i;
 393                 return;
 394         }
 395         PARA_WARNING_LOG("%s", "falling back to the random selector\n");
 396 random:
 397         mmd->selector_num = 0;
 398         selectors[0].init(&selectors[0]); /* always successful */
 399 }
 400
 401 static unsigned init_network(void)
 402 {
 403         int fd, ret = init_tcp_socket(conf.port_arg);
 404
 405         if (ret < 0)
 406                 goto err;
 407         fd = ret;
 408         ret = mark_fd_nonblock(fd);
 409         if (ret < 0)
 410                 goto err;
 411         return fd;
 412 err:
 413         PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
 414         exit(EXIT_FAILURE);
 415 }
 416
 417 static void init_random_seed(void)
 418 {
 419         int fd, ret = -1, len = sizeof(unsigned int);
 420         unsigned int seed;
 421
 422         fd = open("/dev/urandom", O_RDONLY);
 423         if (fd < 0)
 424                 goto out;
 425         ret = -2;
 426         if (read(fd, &seed, len) != len)
 427                 goto out;
 428         srandom(seed);
 429         ret = 1;
 430 out:
 431         if (fd >= 0)
 432                 close(fd);
 433         if (ret > 0)
 434                 return;
 435         PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
 436                 ret);
 437         exit(EXIT_FAILURE);
 438 }
 439
 440 static unsigned do_inits(int argc, char **argv)
 441 {
 442         /* connector's address information */
 443         int sockfd;
 444
 445         init_random_seed();
 446         /* parse command line options */
 447         server_cmdline_parser(argc, argv, &conf);
 448         para_drop_privileges(conf.user_arg, conf.group_arg);
 449         /* parse config file, open log and set defaults */
 450         parse_config(0);
 451         log_welcome("para_server", conf.loglevel_arg);
 452         shm_init(); /* init mmd struct */
 453         server_uptime(UPTIME_SET); /* reset server uptime */
 454         init_user_list();
 455         /* become daemon */
 456         if (conf.daemon_given)
 457                 daemon_init();
 458         init_selector();
 459         PARA_NOTICE_LOG("%s", "initializing audio file sender\n");
 460         /* audio file sender */
 461         afs_init();
 462         mmd->server_pid = getpid();
 463         setup_signal_handling();
 464         mmd_lock();
 465         /* init network socket */
 466         PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
 467         sockfd = init_network();
 468         PARA_NOTICE_LOG("%s", "init complete\n");
 469         return sockfd;
 470 }
 471
 472 static void change_selector(void)
 473 {
 474         int ret, old = mmd->selector_num, new = mmd->selector_change;
 475
 476         selectors[old].shutdown();
 477         ret = selectors[new].init(&selectors[new]);
 478         mmd->selector_change = -1; /* reset */
 479         if (ret >= 0) {
 480                 mmd->selector_num = new;
 481                 return;
 482         }
 483         /* init failed */
 484         PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
 485         selectors[0].init(&selectors[0]);
 486         mmd->selector_num = 0;
 487 }
 488
 489 /*
 490  * called when server gets SIGHUP or when client invokes hup command.
 491  */
 492 static void handle_sighup(void)
 493 {
 494         PARA_NOTICE_LOG("%s", "SIGHUP\n");
 495         close_log(logfile); /* gets reopened if necessary by parse_config */
 496         logfile = NULL;
 497         parse_config(1); /* reopens log */
 498         mmd->selector_change = mmd->selector_num; /* do not change selector.. */
 499         change_selector(); /* .. just reload */
 500 }
 501
 502 static void status_refresh(void)
 503 {
 504         static int prev_uptime = -1, prev_events = -1;
 505         int uptime = server_uptime(UPTIME_GET), ret = 1;
 506
 507         if (prev_events != mmd->events)
 508                 goto out;
 509         if (mmd->new_afs_status_flags != mmd->afs_status_flags)
 510                 goto out;
 511         if (uptime / 60 != prev_uptime / 60)
 512                 goto out;
 513         ret = 0;
 514 out:
 515         prev_uptime = uptime;
 516         prev_events = mmd->events;
 517         mmd->afs_status_flags = mmd->new_afs_status_flags;
 518         if (ret) {
 519                 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
 520                         mmd->events, mmd->audio_format);
 521                 killpg(0, SIGUSR1);
 522         }
 523 }
 524
 525 /*
 526  * MAIN
 527  */
 528 int main(int argc, char *argv[])
 529 {
 530         /* listen on sock_fd, new connection on new_fd */
 531         int sockfd, new_fd;
 532         struct sockaddr_in their_addr;
 533         int i, max_fileno, ret;
 534         pid_t chld_pid;
 535         fd_set rfds, wfds;
 536         struct timeval *timeout;
 537
 538         valid_fd_012();
 539         sockfd = do_inits(argc, argv);
 540 repeat:
 541         FD_ZERO(&rfds);
 542         FD_ZERO(&wfds);
 543         max_fileno = -1;
 544         /* check socket and signal pipe in any case */
 545         para_fd_set(sockfd, &rfds, &max_fileno);
 546         para_fd_set(signal_pipe, &rfds, &max_fileno);
 547         timeout = afs_preselect();
 548         status_refresh();
 549         for (i = 0; senders[i].name; i++) {
 550                 if (senders[i].status != SENDER_ON)
 551                         continue;
 552                 if (!senders[i].pre_select)
 553                         continue;
 554                 senders[i].pre_select( &max_fileno, &rfds, &wfds);
 555         }
 556         if (selectors[mmd->selector_num].pre_select) {
 557                 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
 558                 max_fileno = PARA_MAX(max_fileno, ret);
 559         }
 560         mmd_unlock();
 561         ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
 562         mmd_lock();
 563         if (mmd->selector_change >= 0)
 564                 change_selector();
 565         if (selectors[mmd->selector_num].post_select)
 566                 selectors[mmd->selector_num].post_select(&rfds, &wfds);
 567         if (ret < 0)
 568                 goto repeat;
 569         for (i = 0; senders[i].name; i++) {
 570                 if (senders[i].status != SENDER_ON)
 571                         continue;
 572                 if (!senders[i].post_select)
 573                         continue;
 574                 senders[i].post_select(&rfds, &wfds);
 575         }
 576         afs_send_chunk();
 577         status_refresh();
 578         if (FD_ISSET(signal_pipe, &rfds)) {
 579                 int sig;
 580                 sig = para_next_signal();
 581                 switch (sig) {
 582                 case SIGHUP:
 583                         handle_sighup();
 584                         break;
 585                 case SIGCHLD:
 586                         para_reap_children();
 587                         break;
 588                 /* die on sigint/sigterm. Kill all children too. */
 589                 case SIGINT:
 590                 case SIGTERM:
 591                         PARA_EMERG_LOG("terminating on signal %d\n", sig);
 592                         kill(0, SIGTERM);
 593                         selectors[mmd->selector_num].shutdown();
 594                         mutex_destroy(mmd_mutex);
 595                         shm_detach(mmd);
 596                         shm_destroy(mmd_shm_id);
 597                         exit(EXIT_FAILURE);
 598                 }
 599         }
 600         if (mmd->sender_cmd_data.cmd_num >= 0) {
 601                 int num = mmd->sender_cmd_data.cmd_num,
 602                         s = mmd->sender_cmd_data.sender_num;
 603
 604                 if (senders[s].client_cmds[num])
 605                         senders[s].client_cmds[num](&mmd->sender_cmd_data);
 606                 mmd->sender_cmd_data.cmd_num = -1;
 607         }
 608         if (!FD_ISSET(sockfd, &rfds))
 609                 goto repeat;
 610
 611         new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
 612         if (new_fd < 0)
 613                 goto repeat;
 614         PARA_INFO_LOG("got connection from %s, forking\n",
 615                 inet_ntoa(their_addr.sin_addr));
 616         mmd->num_connects++;
 617         mmd->active_connections++;
 618         random();
 619         chld_pid = fork();
 620         if (chld_pid < 0) {
 621                 PARA_CRIT_LOG("%s", "fork failed\n");
 622                 goto repeat;
 623         }
 624         if (chld_pid) {
 625                 close(new_fd);
 626                 /* parent keeps accepting connections */
 627                 goto repeat;
 628         }
 629         alarm(ALARM_TIMEOUT);
 630         close_listed_fds();
 631         close(sockfd); /* child doesn't need the listener */
 632         /*
 633          * put info on who we are serving into argv[0] to make
 634          * client ip visible in top/ps
 635          */
 636         for (i = argc - 1; i >= 0; i--)
 637                 memset(argv[i], 0, strlen(argv[i]));
 638         sprintf(argv[0], "para_server (serving %s)",
 639                 inet_ntoa(their_addr.sin_addr));
 640         return handle_connect(new_fd, &their_addr);
 641 }