2 * Copyright (C) 1997-2011 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file server.c Paraslash's main server. */
11 * \mainpage Paraslash API Reference
13 * Starting points for getting an overview:
16 * - The main programs: \ref server.c, \ref audiod.c, \ref client.c,
17 * \ref audioc.c, \ref afh.c
18 * - Server: \ref server_command, \ref sender,
19 * - Audio file selector: \ref audio_format_handler, \ref afs_table,
20 * - Client: \ref receiver, \ref receiver_node, \ref filter, \ref filter_node.
23 * The gory details, listed by topic:
25 * - Audio format handlers: \ref send_common.c \ref mp3_afh.c,
26 * \ref ogg_afh.c, \ref aac_afh.c, \ref wma_afh.c, \ref spx_afh.c
27 * - Decoders: \ref mp3dec_filter.c, \ref oggdec_filter.c,
28 * \ref aacdec_filter.c, \ref wmadec_filter.c, spxdec_filter.c,
29 * - Volume normalizer: \ref compress_filter.c,
30 * - Output: \ref alsa_write.c, \ref osx_write.c, \ref oss_write.c,
31 * - http: \ref http_recv.c, \ref http_send.c,
32 * - udp: \ref udp_recv.c, \ref udp_send.c,
33 * - dccp: \ref dccp_recv.c, \ref dccp_send.c,
34 * - Audio file selector: \ref afs.c, \ref aft.c, \ref mood.c,
35 * - Afs structures: \ref afs_table, \ref audio_file_data,
36 * \ref afs_info \ref afh_info,
37 * - Afs tables: \ref aft.c, \ref mood.c, \ref playlist.c,
38 * \ref attribute.c, \ref score.c,
39 * - The virtual streaming system: \ref vss.c, \ref chunk_queue.c.
43 * - Scheduling: \ref sched.c, \ref sched.h,
44 * - Networking: \ref net.c,
45 * - File descriptors: \ref fd.c,
46 * - Signals: \ref signal.c,
47 * - Daemons: \ref daemon.c,
48 * - Strings: \ref string.c, \ref string.h,
49 * - Time: \ref time.c,
50 * - Spawning processes: \ref exec.c,
51 * - Inter process communication: \ref ipc.c,
52 * - Blob tables: \ref blob.c,
53 * - The error subssystem: \ref error.h.
54 * - Access control for paraslash senders: \ref acl.c, \ref acl.h.
56 * Low-level data structures:
58 * - Doubly linked lists: \ref list.h,
59 * - Ring buffer: \ref ringbuffer.c, \ref ringbuffer.h,
60 * - Hashing: \ref hash.h, \ref sha1.h, \ref sha1.c,
61 * - Crypto: \ref crypt.c.
62 * - Forward error correction: \ref fec.c.
68 #include <openssl/rc4.h>
76 #include "server.cmdline.h"
85 #include "close_on_fork.h"
92 #include "user_list.h"
96 /** Define the array of error lists needed by para_server. */
99 /** Shut down non-authorized connections after that many seconds. */
100 #define ALARM_TIMEOUT 10
103 * Pointer to shared memory area for communication between para_server
104 * and its children. Exported to vss.c. command.c and to afs.
106 struct misc_meta_data *mmd;
109 * The configuration of para_server
111 * It also contains the options for the audio file selector, audio format
112 * handler and all supported senders.
114 struct server_args_info conf;
116 /** A random value used in child context for authentication. */
117 uint32_t afs_socket_cookie;
119 /** The mutex protecting the shared memory area containing the mmd struct. */
122 /** The file containing user information (public key, permissions). */
123 static char *user_list_file = NULL;
126 /** The task responsible for server command handling. */
127 struct server_command_task {
128 /** TCP port on which para_server listens for connections. */
130 /** Copied from para_server's main function. */
132 /** Argument vector passed to para_server's main function. */
134 /** The command task structure for scheduling. */
138 static int want_colors(void)
140 if (conf.color_arg == color_arg_no)
142 if (conf.color_arg == color_arg_yes)
144 if (conf.logfile_given)
146 return isatty(STDERR_FILENO);
149 static void init_colors_or_die(void)
155 daemon_set_flag(DF_COLOR_LOG);
156 daemon_set_default_log_colors();
157 for (i = 0; i < conf.log_color_given; i++)
158 daemon_set_log_color_or_die(conf.log_color_arg[i]);
162 * setup shared memory area and get mutex for locking
164 static void init_ipc_or_die(void)
167 int shmid, ret = shm_new(sizeof(struct misc_meta_data));
172 ret = shm_attach(shmid, ATTACH_RW, &shm);
184 mmd->num_commands = 0;
186 mmd->num_connects = 0;
187 mmd->active_connections = 0;
188 mmd->vss_status_flags = VSS_NEXT;
189 mmd->new_vss_status_flags = VSS_NEXT;
192 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
197 * (Re-)read the server configuration files.
199 * \param override Passed to gengetopt to activate the override feature.
201 * This function also re-opens the logfile and sets the global \a
202 * user_list_file variable.
204 void parse_config_or_die(int override)
206 char *home = para_homedir();
211 if (conf.config_file_given)
212 cf = para_strdup(conf.config_file_arg);
214 cf = make_message("%s/.paraslash/server.conf", home);
215 free(user_list_file);
216 if (!conf.user_list_given)
217 user_list_file = make_message("%s/.paraslash/server.users", home);
219 user_list_file = para_strdup(conf.user_list_arg);
220 ret = file_exists(cf);
221 if (conf.config_file_given && !ret) {
223 PARA_EMERG_LOG("can not read config file %s\n", cf);
227 int tmp = conf.daemon_given;
228 struct server_cmdline_parser_params params = {
229 .override = override,
232 .check_ambiguity = 0,
233 .print_errors = !conf.daemon_given
235 server_cmdline_parser_config_file(cf, &conf, ¶ms);
236 conf.daemon_given = tmp;
238 if (conf.logfile_given) {
239 daemon_set_logfile(conf.logfile_arg);
240 daemon_open_log_or_die();
242 daemon_set_loglevel(conf.loglevel_arg);
243 init_colors_or_die();
244 daemon_set_flag(DF_LOG_PID);
245 daemon_set_flag(DF_LOG_LL);
246 daemon_set_flag(DF_LOG_TIME);
247 if (conf.log_timing_given)
248 daemon_set_flag(DF_LOG_TIMING);
255 free(user_list_file);
256 user_list_file = NULL;
260 static void signal_pre_select(struct sched *s, struct task *t)
262 struct signal_task *st = container_of(t, struct signal_task, task);
263 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
267 * called when server gets SIGHUP or when client invokes hup command.
269 static void handle_sighup(void)
271 PARA_NOTICE_LOG("SIGHUP\n");
272 parse_config_or_die(1); /* reopens log */
273 init_user_list(user_list_file); /* reload user list */
275 kill(mmd->afs_pid, SIGHUP);
278 static void signal_post_select(struct sched *s, __a_unused struct task *t)
280 int signum = para_next_signal(&s->rfds);
291 int ret = para_reap_child(&pid);
294 if (pid != mmd->afs_pid)
296 PARA_EMERG_LOG("fatal: afs died\n");
301 /* die on sigint/sigterm. Kill all children too. */
304 PARA_EMERG_LOG("terminating on signal %d\n", signum);
307 * We must wait for afs because afs catches SIGINT/SIGTERM.
308 * Before reacting to the signal, afs might want to use the
309 * shared memory area and the mmd mutex. If we destroy this
310 * mutex too early and afs tries to lock the shared memory
311 * area, the call to mutex_lock() will fail and terminate the
312 * afs process. This leads to dirty osl tables.
314 * There's no such problem with the other children of the
315 * server process (the command handlers) as these reset their
316 * SIGINT/SIGTERM handlers to the default action, i.e. these
317 * processes get killed immediately by the above kill().
319 PARA_INFO_LOG("waiting for afs (pid %d) to die\n",
321 waitpid(mmd->afs_pid, NULL, 0);
323 free(mmd->afd.afhi.chunk_table);
325 mutex_destroy(mmd_mutex);
331 static void init_signal_task(void)
333 static struct signal_task signal_task_struct,
334 *st = &signal_task_struct;
336 st->task.pre_select = signal_pre_select;
337 st->task.post_select = signal_post_select;
338 sprintf(st->task.status, "signal task");
340 PARA_NOTICE_LOG("setting up signal handling\n");
341 st->fd = para_signal_init(); /* always successful */
342 para_install_sighandler(SIGINT);
343 para_install_sighandler(SIGTERM);
344 para_install_sighandler(SIGHUP);
345 para_install_sighandler(SIGCHLD);
346 para_sigaction(SIGPIPE, SIG_IGN);
347 add_close_on_fork_list(st->fd);
348 register_task(&st->task);
351 static void command_pre_select(struct sched *s, struct task *t)
353 struct server_command_task *sct = container_of(t, struct server_command_task, task);
354 para_fd_set(sct->listen_fd, &s->rfds, &s->max_fileno);
357 static void command_post_select(struct sched *s, struct task *t)
359 struct server_command_task *sct = container_of(t, struct server_command_task, task);
364 uint32_t *chunk_table;
366 ret = para_accept(sct->listen_fd, &s->rfds, NULL, 0, &new_fd);
369 peer_name = remote_name(new_fd);
370 PARA_INFO_LOG("got connection from %s, forking\n", peer_name);
372 mmd->active_connections++;
374 * The chunk table is a pointer located in the mmd struct that points
375 * to dynamically allocated memory, i.e. it must be freed by the parent
376 * and the child. However, as the mmd struct is in a shared memory
377 * area, there's no guarantee that after the fork this pointer is still
378 * valid in child context. As it is not used in the child anyway, we
379 * save it to a local variable before the fork and free the memory via
380 * that copy in the child directly after the fork.
382 chunk_table = mmd->afd.afhi.chunk_table;
385 ret = -ERRNO_TO_PARA_ERROR(errno);
390 /* parent keeps accepting connections */
393 /* mmd might already have changed at this point */
395 alarm(ALARM_TIMEOUT);
397 para_signal_shutdown();
399 * put info on who we are serving into argv[0] to make
400 * client ip visible in top/ps
402 for (i = sct->argc - 1; i >= 0; i--)
403 memset(sct->argv[i], 0, strlen(sct->argv[i]));
404 sprintf(sct->argv[0], "para_server (serving %s)", peer_name);
405 return handle_connect(new_fd, peer_name);
408 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
411 static void init_server_command_task(int argc, char **argv)
414 static struct server_command_task server_command_task_struct,
415 *sct = &server_command_task_struct;
417 PARA_NOTICE_LOG("initializing tcp command socket\n");
418 sct->task.pre_select = command_pre_select;
419 sct->task.post_select = command_post_select;
422 ret = para_listen_simple(IPPROTO_TCP, conf.port_arg);
425 sct->listen_fd = ret;
426 ret = mark_fd_nonblocking(sct->listen_fd);
429 add_close_on_fork_list(sct->listen_fd); /* child doesn't need the listener */
430 sprintf(sct->task.status, "server command task");
431 register_task(&sct->task);
434 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
438 static int init_afs(void)
440 int ret, afs_server_socket[2];
443 ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
446 get_random_bytes_or_die((unsigned char *)&afs_socket_cookie,
447 sizeof(afs_socket_cookie));
451 if (afs_pid == 0) { /* child (afs) */
452 close(afs_server_socket[0]);
453 afs_init(afs_socket_cookie, afs_server_socket[1]);
455 mmd->afs_pid = afs_pid;
456 close(afs_server_socket[1]);
457 ret = mark_fd_nonblocking(afs_server_socket[0]);
460 add_close_on_fork_list(afs_server_socket[0]);
461 PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n",
462 afs_server_socket[0], (unsigned) afs_socket_cookie);
463 return afs_server_socket[0];
466 __noreturn static void tmp_sigchld_handler(__a_unused int s)
468 PARA_EMERG_LOG("caught early SIGCHLD\n");
472 static void server_init(int argc, char **argv)
474 struct server_cmdline_parser_params params = {
478 .check_ambiguity = 0,
484 init_random_seed_or_die();
485 /* parse command line options */
486 server_cmdline_parser_ext(argc, argv, &conf, ¶ms);
487 HANDLE_VERSION_FLAG("server", conf);
488 drop_privileges_or_die(conf.user_arg, conf.group_arg);
489 /* parse config file, open log and set defaults */
490 parse_config_or_die(0);
491 log_welcome("para_server");
492 init_ipc_or_die(); /* init mmd struct and mmd->lock */
493 /* make sure, the global now pointer is uptodate */
494 gettimeofday(now, NULL);
495 server_uptime(UPTIME_SET); /* reset server uptime */
496 init_user_list(user_list_file);
498 if (conf.daemon_given)
500 PARA_NOTICE_LOG("initializing audio format handlers\n");
504 * Although afs uses its own signal handling we must ignore SIGUSR1
505 * _before_ the afs child process gets born by init_afs() below. It's
506 * racy to do this in the child because the parent might send SIGUSR1
507 * before the child gets a chance to ignore this signal -- only the
510 para_sigaction(SIGUSR1, SIG_IGN);
512 * We have to install a SIGCHLD handler before the afs process is being
513 * forked off. Otherwise, para_server does not notice if afs dies before
514 * the SIGCHLD handler has been installed by init_signal_task() below.
516 para_sigaction(SIGCHLD, tmp_sigchld_handler);
517 PARA_NOTICE_LOG("initializing the audio file selector\n");
518 afs_socket = init_afs();
520 PARA_NOTICE_LOG("initializing virtual streaming system\n");
521 init_vss_task(afs_socket);
522 init_server_command_task(argc, argv);
523 PARA_NOTICE_LOG("server init complete\n");
526 static void status_refresh(void)
528 static int prev_uptime = -1, prev_events = -1;
529 int uptime = server_uptime(UPTIME_GET), ret = 1;
531 if (prev_events != mmd->events)
533 if (mmd->new_vss_status_flags != mmd->vss_status_flags)
535 if (uptime / 60 != prev_uptime / 60)
541 prev_uptime = uptime;
542 prev_events = mmd->events;
543 mmd->vss_status_flags = mmd->new_vss_status_flags;
545 PARA_DEBUG_LOG("%d events, forcing status update\n",
551 static int server_select(int max_fileno, fd_set *readfds, fd_set *writefds,
552 struct timeval *timeout_tv)
557 mutex_unlock(mmd_mutex);
558 ret = para_select(max_fileno + 1, readfds, writefds, timeout_tv);
559 mutex_lock(mmd_mutex);
564 * The main function of para_server.
566 * \param argc Usual argument count.
567 * \param argv Usual argument vector.
569 * \return EXIT_SUCCESS or EXIT_FAILURE.
571 int main(int argc, char *argv[])
574 static struct sched s = {
579 .select_function = server_select
581 server_init(argc, argv);
582 mutex_lock(mmd_mutex);
585 PARA_EMERG_LOG("%s\n", para_strerror(-ret));