2 * Copyright (C) 1997-2013 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, \ref play.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,
21 * \ref filter_node, \ref writer_node.
24 * The gory details, listed by topic:
26 * - Audio format handlers: \ref send_common.c \ref mp3_afh.c,
27 * \ref ogg_afh.c, \ref aac_afh.c, \ref wma_afh.c, \ref spx_afh.c
28 * - Decoders: \ref mp3dec_filter.c, \ref oggdec_filter.c,
29 * \ref aacdec_filter.c, \ref wmadec_filter.c, spxdec_filter.c,
30 * \ref flacdec_filter.c,
31 * - Volume normalizer: \ref compress_filter.c,
32 * - Output: \ref alsa_write.c, \ref osx_write.c, \ref oss_write.c,
33 * - http: \ref http_recv.c, \ref http_send.c,
34 * - udp: \ref udp_recv.c, \ref udp_send.c,
35 * - dccp: \ref dccp_recv.c, \ref dccp_send.c,
36 * - Audio file selector: \ref afs.c, \ref aft.c, \ref mood.c,
37 * - Afs structures: \ref afs_table, \ref audio_file_data,
38 * \ref afs_info \ref afh_info,
39 * - Afs tables: \ref aft.c, \ref mood.c, \ref playlist.c,
40 * \ref attribute.c, \ref score.c,
41 * - The virtual streaming system: \ref vss.c, \ref chunk_queue.c.
45 * - Scheduling: \ref sched.c, \ref sched.h,
46 * - Networking: \ref net.c,
47 * - File descriptors: \ref fd.c,
48 * - Signals: \ref signal.c,
49 * - Daemons: \ref daemon.c,
50 * - Strings: \ref string.c, \ref string.h,
51 * - Time: \ref time.c,
52 * - Spawning processes: \ref exec.c,
53 * - Inter process communication: \ref ipc.c,
54 * - Blob tables: \ref blob.c,
55 * - The error subsystem: \ref error.h.
56 * - Access control for paraslash senders: \ref acl.c, \ref acl.h.
57 * - Internal crypto API: \ref crypt.h.
58 * - interactive sessions (libreadline): \ref interactive.c.
60 * Low-level data structures:
62 * - Doubly linked lists: \ref list.h,
63 * - Ring buffer: \ref ringbuffer.c, \ref ringbuffer.h,
64 * - openssl: \ref crypt.c
65 * - libgcrypt: \ref gcrypt.c
66 * - Forward error correction: \ref fec.c.
76 #include "server.cmdline.h"
86 #include "close_on_fork.h"
92 #include "user_list.h"
96 __printf_2_3
void (*para_log
)(int, const char*, ...) = daemon_log
;
98 /** Define the array of error lists needed by para_server. */
101 /** Shut down non-authorized connections after that many seconds. */
102 #define ALARM_TIMEOUT 10
105 * Pointer to shared memory area for communication between para_server
106 * and its children. Exported to vss.c. command.c and to afs.
108 struct misc_meta_data
*mmd
;
111 * The configuration of para_server
113 * It also contains the options for the audio file selector, audio format
114 * handler and all supported senders.
116 struct server_args_info conf
;
118 /** A random value used in child context for authentication. */
119 uint32_t afs_socket_cookie
;
121 /** The mutex protecting the shared memory area containing the mmd struct. */
124 /** The file containing user information (public key, permissions). */
125 static char *user_list_file
= NULL
;
127 static struct sched sched
;
129 /** The task responsible for server command handling. */
130 struct server_command_task
{
131 /** TCP port on which para_server listens for connections. */
133 /** Copied from para_server's main function. */
135 /** Argument vector passed to para_server's main function. */
137 /** The command task structure for scheduling. */
141 static int want_colors(void)
143 if (conf
.color_arg
== color_arg_no
)
145 if (conf
.color_arg
== color_arg_yes
)
147 if (conf
.logfile_given
)
149 return isatty(STDERR_FILENO
);
152 static void init_colors_or_die(void)
158 daemon_set_flag(DF_COLOR_LOG
);
159 daemon_set_default_log_colors();
160 for (i
= 0; i
< conf
.log_color_given
; i
++)
161 daemon_set_log_color_or_die(conf
.log_color_arg
[i
]);
165 * setup shared memory area and get mutex for locking
167 static void init_ipc_or_die(void)
170 int shmid
, ret
= shm_new(sizeof(struct misc_meta_data
));
175 ret
= shm_attach(shmid
, ATTACH_RW
, &shm
);
187 mmd
->num_commands
= 0;
189 mmd
->num_connects
= 0;
190 mmd
->active_connections
= 0;
191 mmd
->vss_status_flags
= VSS_NEXT
;
192 mmd
->new_vss_status_flags
= VSS_NEXT
;
195 PARA_EMERG_LOG("%s\n", para_strerror(-ret
));
200 * (Re-)read the server configuration files.
202 * \param override Passed to gengetopt to activate the override feature.
204 * This function also re-opens the logfile and sets the global \a
205 * user_list_file variable.
207 void parse_config_or_die(int override
)
209 char *home
= para_homedir();
214 if (conf
.config_file_given
)
215 cf
= para_strdup(conf
.config_file_arg
);
217 cf
= make_message("%s/.paraslash/server.conf", home
);
218 free(user_list_file
);
219 if (!conf
.user_list_given
)
220 user_list_file
= make_message("%s/.paraslash/server.users", home
);
222 user_list_file
= para_strdup(conf
.user_list_arg
);
223 ret
= file_exists(cf
);
224 if (conf
.config_file_given
&& !ret
) {
226 PARA_EMERG_LOG("can not read config file %s\n", cf
);
230 int tmp
= conf
.daemon_given
;
231 struct server_cmdline_parser_params params
= {
232 .override
= override
,
235 .check_ambiguity
= 0,
236 .print_errors
= !conf
.daemon_given
238 server_cmdline_parser_config_file(cf
, &conf
, ¶ms
);
239 conf
.daemon_given
= tmp
;
241 if (conf
.logfile_given
) {
242 daemon_set_logfile(conf
.logfile_arg
);
243 daemon_open_log_or_die();
245 daemon_set_loglevel(conf
.loglevel_arg
);
246 init_colors_or_die();
247 daemon_set_flag(DF_LOG_PID
);
248 daemon_set_flag(DF_LOG_LL
);
249 daemon_set_flag(DF_LOG_TIME
);
250 if (conf
.log_timing_given
)
251 daemon_set_flag(DF_LOG_TIMING
);
258 free(user_list_file
);
259 user_list_file
= NULL
;
263 static void signal_pre_select(struct sched
*s
, struct task
*t
)
265 struct signal_task
*st
= container_of(t
, struct signal_task
, task
);
266 para_fd_set(st
->fd
, &s
->rfds
, &s
->max_fileno
);
270 * called when server gets SIGHUP or when client invokes hup command.
272 static void handle_sighup(void)
274 PARA_NOTICE_LOG("SIGHUP\n");
275 parse_config_or_die(1); /* reopens log */
276 init_user_list(user_list_file
); /* reload user list */
278 kill(mmd
->afs_pid
, SIGHUP
);
281 static void signal_post_select(struct sched
*s
, __a_unused
struct task
*t
)
283 int signum
= para_next_signal(&s
->rfds
);
294 int ret
= para_reap_child(&pid
);
297 if (pid
!= mmd
->afs_pid
)
299 PARA_EMERG_LOG("fatal: afs died\n");
304 /* die on sigint/sigterm. Kill all children too. */
307 PARA_EMERG_LOG("terminating on signal %d\n", signum
);
310 * We must wait for afs because afs catches SIGINT/SIGTERM.
311 * Before reacting to the signal, afs might want to use the
312 * shared memory area and the mmd mutex. If we destroy this
313 * mutex too early and afs tries to lock the shared memory
314 * area, the call to mutex_lock() will fail and terminate the
315 * afs process. This leads to dirty osl tables.
317 * There's no such problem with the other children of the
318 * server process (the command handlers) as these reset their
319 * SIGINT/SIGTERM handlers to the default action, i.e. these
320 * processes get killed immediately by the above kill().
322 PARA_INFO_LOG("waiting for afs (pid %d) to die\n",
324 waitpid(mmd
->afs_pid
, NULL
, 0);
326 free(mmd
->afd
.afhi
.chunk_table
);
328 mutex_destroy(mmd_mutex
);
334 static void init_signal_task(void)
336 static struct signal_task signal_task_struct
,
337 *st
= &signal_task_struct
;
339 st
->task
.pre_select
= signal_pre_select
;
340 st
->task
.post_select
= signal_post_select
;
341 sprintf(st
->task
.status
, "signal task");
343 PARA_NOTICE_LOG("setting up signal handling\n");
344 st
->fd
= para_signal_init(); /* always successful */
345 para_install_sighandler(SIGINT
);
346 para_install_sighandler(SIGTERM
);
347 para_install_sighandler(SIGHUP
);
348 para_install_sighandler(SIGCHLD
);
349 para_sigaction(SIGPIPE
, SIG_IGN
);
350 add_close_on_fork_list(st
->fd
);
351 register_task(&sched
, &st
->task
);
354 static void command_pre_select(struct sched
*s
, struct task
*t
)
356 struct server_command_task
*sct
= container_of(t
, struct server_command_task
, task
);
357 para_fd_set(sct
->listen_fd
, &s
->rfds
, &s
->max_fileno
);
360 static void command_post_select(struct sched
*s
, struct task
*t
)
362 struct server_command_task
*sct
= container_of(t
, struct server_command_task
, task
);
367 uint32_t *chunk_table
;
369 ret
= para_accept(sct
->listen_fd
, &s
->rfds
, NULL
, 0, &new_fd
);
372 peer_name
= remote_name(new_fd
);
373 PARA_INFO_LOG("got connection from %s, forking\n", peer_name
);
375 mmd
->active_connections
++;
377 * The chunk table is a pointer located in the mmd struct that points
378 * to dynamically allocated memory, i.e. it must be freed by the parent
379 * and the child. However, as the mmd struct is in a shared memory
380 * area, there's no guarantee that after the fork this pointer is still
381 * valid in child context. As it is not used in the child anyway, we
382 * save it to a local variable before the fork and free the memory via
383 * that copy in the child directly after the fork.
385 chunk_table
= mmd
->afd
.afhi
.chunk_table
;
388 ret
= -ERRNO_TO_PARA_ERROR(errno
);
393 /* parent keeps accepting connections */
396 /* mmd might already have changed at this point */
398 alarm(ALARM_TIMEOUT
);
400 para_signal_shutdown();
402 * put info on who we are serving into argv[0] to make
403 * client ip visible in top/ps
405 for (i
= sct
->argc
- 1; i
>= 0; i
--)
406 memset(sct
->argv
[i
], 0, strlen(sct
->argv
[i
]));
407 sprintf(sct
->argv
[0], "para_server (serving %s)", peer_name
);
408 return handle_connect(new_fd
, peer_name
);
411 PARA_CRIT_LOG("%s\n", para_strerror(-ret
));
414 static void init_server_command_task(int argc
, char **argv
)
417 static struct server_command_task server_command_task_struct
,
418 *sct
= &server_command_task_struct
;
420 PARA_NOTICE_LOG("initializing tcp command socket\n");
421 sct
->task
.pre_select
= command_pre_select
;
422 sct
->task
.post_select
= command_post_select
;
425 ret
= para_listen_simple(IPPROTO_TCP
, conf
.port_arg
);
428 sct
->listen_fd
= ret
;
429 ret
= mark_fd_nonblocking(sct
->listen_fd
);
432 add_close_on_fork_list(sct
->listen_fd
); /* child doesn't need the listener */
433 sprintf(sct
->task
.status
, "server command task");
434 register_task(&sched
, &sct
->task
);
437 PARA_EMERG_LOG("%s\n", para_strerror(-ret
));
441 static int init_afs(int argc
, char **argv
)
443 int ret
, afs_server_socket
[2];
446 ret
= socketpair(PF_UNIX
, SOCK_DGRAM
, 0, afs_server_socket
);
449 get_random_bytes_or_die((unsigned char *)&afs_socket_cookie
,
450 sizeof(afs_socket_cookie
));
454 if (afs_pid
== 0) { /* child (afs) */
456 for (i
= argc
- 1; i
>= 0; i
--)
457 memset(argv
[i
], 0, strlen(argv
[i
]));
458 sprintf(argv
[0], "para_server (afs)");
459 close(afs_server_socket
[0]);
460 afs_init(afs_socket_cookie
, afs_server_socket
[1]);
462 mmd
->afs_pid
= afs_pid
;
463 close(afs_server_socket
[1]);
464 ret
= mark_fd_nonblocking(afs_server_socket
[0]);
467 add_close_on_fork_list(afs_server_socket
[0]);
468 PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n",
469 afs_server_socket
[0], (unsigned) afs_socket_cookie
);
470 return afs_server_socket
[0];
473 static void server_init(int argc
, char **argv
)
475 struct server_cmdline_parser_params params
= {
479 .check_ambiguity
= 0,
485 init_random_seed_or_die();
486 /* parse command line options */
487 server_cmdline_parser_ext(argc
, argv
, &conf
, ¶ms
);
488 HANDLE_VERSION_FLAG("server", conf
);
489 drop_privileges_or_die(conf
.user_arg
, conf
.group_arg
);
490 /* parse config file, open log and set defaults */
491 parse_config_or_die(0);
492 log_welcome("para_server");
493 init_ipc_or_die(); /* init mmd struct and mmd->lock */
494 /* make sure, the global now pointer is uptodate */
495 clock_get_realtime(now
);
496 set_server_start_time(now
);
497 init_user_list(user_list_file
);
499 if (conf
.daemon_given
)
500 daemonize(true /* parent waits for SIGTERM */);
501 PARA_NOTICE_LOG("initializing audio format handlers\n");
505 * Although afs uses its own signal handling we must ignore SIGUSR1
506 * _before_ the afs child process gets born by init_afs() below. It's
507 * racy to do this in the child because the parent might send SIGUSR1
508 * before the child gets a chance to ignore this signal -- only the
511 para_sigaction(SIGUSR1
, SIG_IGN
);
513 * We have to block SIGCHLD before the afs process is being forked off.
514 * Otherwise, para_server does not notice if afs dies before the
515 * SIGCHLD handler has been installed for the parent process by
516 * init_signal_task() below.
518 para_block_signal(SIGCHLD
);
519 PARA_NOTICE_LOG("initializing the audio file selector\n");
520 afs_socket
= init_afs(argc
, argv
);
522 para_unblock_signal(SIGCHLD
);
523 PARA_NOTICE_LOG("initializing virtual streaming system\n");
524 init_vss_task(afs_socket
, &sched
);
525 init_server_command_task(argc
, argv
);
526 if (conf
.daemon_given
)
527 kill(getppid(), SIGTERM
);
528 PARA_NOTICE_LOG("server init complete\n");
531 static void status_refresh(void)
533 static int prev_uptime
= -1, prev_events
= -1;
534 int uptime
= get_server_uptime(now
);
536 if (prev_events
!= mmd
->events
)
538 if (mmd
->new_vss_status_flags
!= mmd
->vss_status_flags
)
540 if (uptime
/ 60 != prev_uptime
/ 60)
546 prev_uptime
= uptime
;
547 prev_events
= mmd
->events
;
548 mmd
->vss_status_flags
= mmd
->new_vss_status_flags
;
549 PARA_DEBUG_LOG("%d events, forcing status update\n", mmd
->events
);
553 static int server_select(int max_fileno
, fd_set
*readfds
, fd_set
*writefds
,
554 struct timeval
*timeout_tv
)
559 mutex_unlock(mmd_mutex
);
560 ret
= para_select(max_fileno
+ 1, readfds
, writefds
, timeout_tv
);
561 mutex_lock(mmd_mutex
);
566 * The main function of para_server.
568 * \param argc Usual argument count.
569 * \param argv Usual argument vector.
571 * \return EXIT_SUCCESS or EXIT_FAILURE.
573 int main(int argc
, char *argv
[])
577 sched
.default_timeout
.tv_sec
= 1;
578 sched
.select_function
= server_select
;
580 server_init(argc
, argv
);
581 mutex_lock(mmd_mutex
);
582 ret
= schedule(&sched
);
584 PARA_EMERG_LOG("%s\n", para_strerror(-ret
));