2 * Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file server.c Paraslash's main server. */
10 * \mainpage Main data structures and selected APIs:
12 * - Senders: \ref sender,
13 * - Audio file selector: \ref afs_info, \ref afs_table,
14 * - Audio format handler: \ref audio_format_handler, \ref afh_info
15 * - Receivers/filters/writers: \ref receiver, \ref receiver_node,
16 * \ref filter, \ref filter_node, \ref writer_node, \ref writer.
17 * - Scheduling: \ref sched.h,
18 * - Buffer trees: \ref buffer_tree.h,
19 * - Sideband API: \ref sideband.h,
20 * - Crypto: \ref crypt.h, \ref crypt_backend.h,
21 * - Error subsystem: \ref error.h,
22 * - Inter process communication: \ref ipc.h,
23 * - Forward error correction: \ref fec.h,
24 * - Daemons: \ref daemon.h,
25 * - Mixer API: \ref mix.h,
26 * - Interactive sessions: \ref interactive.h,
27 * - File descriptors: \ref fd.h,
28 * - Signals: \ref signal.h,
29 * - Networking: \ref net.h,
30 * - Time: \ref time.c,
31 * - Doubly linked lists: \ref list.h.
34 #include <netinet/in.h>
35 #include <sys/socket.h>
39 #include <sys/types.h>
40 #include <arpa/inet.h>
45 #include "server.lsg.h"
58 #include "close_on_fork.h"
64 #include "user_list.h"
68 /** Array of error strings. */
71 __printf_2_3
void (*para_log
)(int, const char*, ...) = daemon_log
;
73 /** Shut down non-authorized connections after that many seconds. */
74 #define ALARM_TIMEOUT 10
77 * Pointer to shared memory area for communication between para_server
78 * and its children. Exported to vss.c, command.c and to afs.
80 struct misc_meta_data
*mmd
;
83 * The active value for all config options of para_server.
85 * It is computed by merging the parse result of the command line options with
86 * the parse result of the config file.
88 struct lls_parse_result
*server_lpr
= NULL
;
90 /* Command line options (no config file options). Used in handle_sighup(). */
91 static struct lls_parse_result
*cmdline_lpr
;
93 /** A random value used in child context for authentication. */
94 uint32_t afs_socket_cookie
;
96 /** The mutex protecting the shared memory area containing the mmd struct. */
99 static struct sched sched
;
100 static struct signal_task
*signal_task
;
102 /** The task responsible for server command handling. */
103 struct server_command_task
{
104 /** TCP port on which para_server listens for connections. */
106 /** Copied from para_server's main function. */
108 /** Argument vector passed to para_server's main function. */
110 /** The command task structure for scheduling. */
115 * Return the list of tasks for the server process.
117 * This is called from \a com_tasks(). The helper is necessary since command
118 * handlers can not access the scheduler structure directly.
120 * \return A dynamically allocated string that must be freed by the caller.
122 char *server_get_tasks(void)
124 return get_task_list(&sched
);
128 * setup shared memory area and get mutex for locking
130 static void init_ipc_or_die(void)
133 int shmid
, ret
= shm_new(sizeof(struct misc_meta_data
));
138 ret
= shm_attach(shmid
, ATTACH_RW
, &shm
);
150 mmd
->num_commands
= 0;
152 mmd
->num_connects
= 0;
153 mmd
->active_connections
= 0;
154 mmd
->vss_status_flags
= VSS_NEXT
;
155 mmd
->new_vss_status_flags
= VSS_NEXT
;
158 PARA_EMERG_LOG("%s\n", para_strerror(-ret
));
163 * (Re-)read the server configuration files.
165 * \param reload Whether config file overrides command line.
167 * This function also re-opens the logfile and the user list. On SIGHUP it is
168 * called from both server and afs context.
170 void parse_config_or_die(bool reload
)
173 char *cf
= NULL
, *errctx
= NULL
, *user_list_file
= NULL
;
178 struct lls_parse_result
*cf_lpr
, *merged_lpr
;
179 char *home
= para_homedir();
182 if (OPT_GIVEN(CONFIG_FILE
))
183 cf
= para_strdup(OPT_STRING_VAL(CONFIG_FILE
));
185 cf
= make_message("%s/.paraslash/server.conf", home
);
186 if (!mmd
|| getpid() != mmd
->afs_pid
) {
187 if (OPT_GIVEN(USER_LIST
))
188 user_list_file
= para_strdup(OPT_STRING_VAL(USER_LIST
));
190 user_list_file
= make_message("%s/.paraslash/server.users", home
);
193 ret
= mmap_full_file(cf
, O_RDONLY
, &map
, &sz
, NULL
);
195 if (ret
!= -E_EMPTY
&& ret
!= -ERRNO_TO_PARA_ERROR(ENOENT
))
197 if (ret
== -ERRNO_TO_PARA_ERROR(ENOENT
) && OPT_GIVEN(CONFIG_FILE
))
200 server_lpr
= cmdline_lpr
;
203 ret
= lls(lls_convert_config(map
, sz
, NULL
, &cf_argv
, &errctx
));
204 para_munmap(map
, sz
);
208 ret
= lls(lls_parse(cf_argc
, cf_argv
, CMD_PTR
, &cf_lpr
, &errctx
));
209 lls_free_argv(cf_argv
);
212 if (reload
) /* config file overrides command line */
213 ret
= lls(lls_merge(cf_lpr
, cmdline_lpr
, CMD_PTR
, &merged_lpr
,
215 else /* command line options overrride config file options */
216 ret
= lls(lls_merge(cmdline_lpr
, cf_lpr
, CMD_PTR
, &merged_lpr
,
218 lls_free_parse_result(cf_lpr
, CMD_PTR
);
221 if (server_lpr
!= cmdline_lpr
)
222 lls_free_parse_result(server_lpr
, CMD_PTR
);
223 server_lpr
= merged_lpr
;
225 daemon_set_loglevel(ENUM_STRING_VAL(LOGLEVEL
));
226 if (OPT_GIVEN(LOGFILE
)) {
227 daemon_set_logfile(OPT_STRING_VAL(LOGFILE
));
228 daemon_open_log_or_die();
230 if (daemon_init_colors_or_die(OPT_UINT32_VAL(COLOR
), COLOR_AUTO
,
231 COLOR_NO
, OPT_GIVEN(LOGFILE
))) {
233 for (i
= 0; i
< OPT_GIVEN(LOG_COLOR
); i
++)
234 daemon_set_log_color_or_die(lls_string_val(i
,
235 OPT_RESULT(LOG_COLOR
)));
237 daemon_set_flag(DF_LOG_PID
);
238 daemon_set_flag(DF_LOG_LL
);
239 daemon_set_flag(DF_LOG_TIME
);
240 if (OPT_GIVEN(LOG_TIMING
))
241 daemon_set_flag(DF_LOG_TIMING
);
242 daemon_set_priority(OPT_UINT32_VAL(PRIORITY
));
244 init_user_list(user_list_file
);
248 free(user_list_file
);
251 PARA_ERROR_LOG("%s\n", errctx
);
253 PARA_EMERG_LOG("%s\n", para_strerror(-ret
));
259 * called when server gets SIGHUP or when client invokes hup command.
261 static void handle_sighup(void)
264 PARA_NOTICE_LOG("SIGHUP\n");
265 parse_config_or_die(true);
267 kill(mmd
->afs_pid
, SIGHUP
);
270 static int signal_post_select(struct sched
*s
, __a_unused
void *context
)
272 int signum
= para_next_signal(&s
->rfds
);
283 int ret
= para_reap_child(&pid
);
286 if (pid
!= mmd
->afs_pid
)
288 PARA_EMERG_LOG("fatal: afs died\n");
293 /* die on sigint/sigterm. Kill all children too. */
296 PARA_EMERG_LOG("terminating on signal %d\n", signum
);
299 * We must wait for afs because afs catches SIGINT/SIGTERM.
300 * Before reacting to the signal, afs might want to use the
301 * shared memory area and the mmd mutex. If we destroy this
302 * mutex too early and afs tries to lock the shared memory
303 * area, the call to mutex_lock() will fail and terminate the
304 * afs process. This leads to dirty osl tables.
306 * There's no such problem with the other children of the
307 * server process (the command handlers) as these reset their
308 * SIGINT/SIGTERM handlers to the default action, i.e. these
309 * processes get killed immediately by the above kill().
311 PARA_INFO_LOG("waiting for afs (pid %d) to die\n",
313 waitpid(mmd
->afs_pid
, NULL
, 0);
315 free(mmd
->afd
.afhi
.chunk_table
);
317 mutex_destroy(mmd_mutex
);
324 static void init_signal_task(void)
326 signal_task
= signal_init_or_die();
327 para_install_sighandler(SIGINT
);
328 para_install_sighandler(SIGTERM
);
329 para_install_sighandler(SIGHUP
);
330 para_install_sighandler(SIGCHLD
);
331 para_sigaction(SIGPIPE
, SIG_IGN
);
332 add_close_on_fork_list(signal_task
->fd
);
333 signal_task
->task
= task_register(&(struct task_info
) {
335 .pre_select
= signal_pre_select
,
336 .post_select
= signal_post_select
,
337 .context
= signal_task
,
342 static void command_pre_select(struct sched
*s
, void *context
)
344 struct server_command_task
*sct
= context
;
345 para_fd_set(sct
->listen_fd
, &s
->rfds
, &s
->max_fileno
);
348 static int command_post_select(struct sched
*s
, void *context
)
350 struct server_command_task
*sct
= context
;
355 uint32_t *chunk_table
;
357 ret
= para_accept(sct
->listen_fd
, &s
->rfds
, NULL
, 0, &new_fd
);
361 mmd
->active_connections
++;
363 * The chunk table is a pointer located in the mmd struct that points
364 * to dynamically allocated memory, i.e. it must be freed by the parent
365 * and the child. However, as the mmd struct is in a shared memory
366 * area, there's no guarantee that after the fork this pointer is still
367 * valid in child context. As it is not used in the child anyway, we
368 * save it to a local variable before the fork and free the memory via
369 * that copy in the child directly after the fork.
371 chunk_table
= mmd
->afd
.afhi
.chunk_table
;
374 ret
= -ERRNO_TO_PARA_ERROR(errno
);
378 /* avoid problems with non-fork-safe PRNGs */
379 unsigned char buf
[16];
380 get_random_bytes_or_die(buf
, sizeof(buf
));
382 /* parent keeps accepting connections */
385 peer_name
= remote_name(new_fd
);
386 PARA_INFO_LOG("accepted connection from %s\n", peer_name
);
387 /* mmd might already have changed at this point */
389 alarm(ALARM_TIMEOUT
);
391 signal_shutdown(signal_task
);
393 * put info on who we are serving into argv[0] to make
394 * client ip visible in top/ps
396 for (i
= sct
->argc
- 1; i
>= 0; i
--)
397 memset(sct
->argv
[i
], 0, strlen(sct
->argv
[i
]));
398 i
= sct
->argc
- 1 - lls_num_inputs(cmdline_lpr
);
399 sprintf(sct
->argv
[i
], "para_server (serving %s)", peer_name
);
400 handle_connect(new_fd
, peer_name
);
404 PARA_CRIT_LOG("%s\n", para_strerror(-ret
));
408 static void init_server_command_task(int argc
, char **argv
)
411 static struct server_command_task server_command_task_struct
,
412 *sct
= &server_command_task_struct
;
414 PARA_NOTICE_LOG("initializing tcp command socket\n");
417 ret
= para_listen_simple(IPPROTO_TCP
, OPT_UINT32_VAL(PORT
));
420 sct
->listen_fd
= ret
;
421 ret
= mark_fd_nonblocking(sct
->listen_fd
);
424 add_close_on_fork_list(sct
->listen_fd
); /* child doesn't need the listener */
425 sct
->task
= task_register(&(struct task_info
) {
426 .name
= "server command",
427 .pre_select
= command_pre_select
,
428 .post_select
= command_post_select
,
433 PARA_EMERG_LOG("%s\n", para_strerror(-ret
));
437 static int init_afs(int argc
, char **argv
)
439 int ret
, afs_server_socket
[2];
443 ret
= socketpair(PF_UNIX
, SOCK_STREAM
, 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) */
454 for (i
= argc
- 1; i
>= 0; i
--)
455 memset(argv
[i
], 0, strlen(argv
[i
]));
456 i
= argc
- lls_num_inputs(cmdline_lpr
) - 1;
457 sprintf(argv
[i
], "para_server (afs)");
458 close(afs_server_socket
[0]);
459 afs_init(afs_socket_cookie
, afs_server_socket
[1]);
461 mmd
->afs_pid
= afs_pid
;
462 close(afs_server_socket
[1]);
463 if (read(afs_server_socket
[0], &c
, 1) <= 0) {
464 PARA_EMERG_LOG("early afs exit\n");
467 ret
= mark_fd_nonblocking(afs_server_socket
[0]);
470 add_close_on_fork_list(afs_server_socket
[0]);
471 PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n",
472 afs_server_socket
[0], (unsigned) afs_socket_cookie
);
473 return afs_server_socket
[0];
476 static void handle_help_flags(void)
479 bool d
= OPT_GIVEN(DETAILED_HELP
);
482 help
= lls_long_help(CMD_PTR
);
483 else if (OPT_GIVEN(HELP
))
484 help
= lls_short_help(CMD_PTR
);
487 printf("%s\n", help
);
492 static void server_init(int argc
, char **argv
)
494 int ret
, afs_socket
, daemon_pipe
= -1;
498 /* parse command line options */
499 ret
= lls(lls_parse(argc
, argv
, CMD_PTR
, &cmdline_lpr
, &errctx
));
502 server_lpr
= cmdline_lpr
;
503 daemon_set_loglevel(ENUM_STRING_VAL(LOGLEVEL
));
504 daemon_drop_privileges_or_die(OPT_STRING_VAL(USER
),
505 OPT_STRING_VAL(GROUP
));
506 version_handle_flag("server", OPT_GIVEN(VERSION
));
508 parse_config_or_die(false);
510 if (OPT_GIVEN(DAEMON
))
511 daemon_pipe
= daemonize(true /* parent waits for SIGTERM */);
512 init_random_seed_or_die();
513 daemon_log_welcome("server");
514 init_ipc_or_die(); /* init mmd struct and mmd->lock */
515 daemon_set_start_time();
516 PARA_NOTICE_LOG("initializing audio format handlers\n");
520 * Although afs uses its own signal handling we must ignore SIGUSR1
521 * _before_ the afs child process gets born by init_afs() below. It's
522 * racy to do this in the child because the parent might send SIGUSR1
523 * before the child gets a chance to ignore this signal.
525 * We also have to block SIGCHLD before the afs process is created
526 * because otherwise para_server does not notice if afs dies before the
527 * SIGCHLD handler has been installed for the parent process by
528 * init_signal_task() below.
530 para_sigaction(SIGUSR1
, SIG_IGN
);
531 para_block_signal(SIGCHLD
);
532 PARA_NOTICE_LOG("initializing the audio file selector\n");
533 afs_socket
= init_afs(argc
, argv
);
535 para_unblock_signal(SIGCHLD
);
536 PARA_NOTICE_LOG("initializing virtual streaming system\n");
537 vss_init(afs_socket
, &sched
);
538 init_server_command_task(argc
, argv
);
539 if (daemon_pipe
>= 0) {
540 if (write(daemon_pipe
, "\0", 1) < 0) {
541 PARA_EMERG_LOG("daemon_pipe: %s", strerror(errno
));
546 PARA_NOTICE_LOG("server init complete\n");
551 PARA_ERROR_LOG("%s\n", errctx
);
552 PARA_EMERG_LOG("%s\n", para_strerror(-ret
));
556 static void status_refresh(void)
558 static int prev_uptime
= -1, prev_events
= -1;
559 int uptime
= daemon_get_uptime(now
);
561 if (prev_events
!= mmd
->events
)
563 if (mmd
->new_vss_status_flags
!= mmd
->vss_status_flags
)
565 if (uptime
/ 60 != prev_uptime
/ 60)
571 prev_uptime
= uptime
;
572 prev_events
= mmd
->events
;
573 mmd
->vss_status_flags
= mmd
->new_vss_status_flags
;
574 PARA_DEBUG_LOG("%u events, forcing status update\n", mmd
->events
);
578 static int server_select(int max_fileno
, fd_set
*readfds
, fd_set
*writefds
,
579 struct timeval
*timeout_tv
)
584 mutex_unlock(mmd_mutex
);
585 ret
= para_select(max_fileno
+ 1, readfds
, writefds
, timeout_tv
);
586 mutex_lock(mmd_mutex
);
591 * The main function of para_server.
593 * \param argc Usual argument count.
594 * \param argv Usual argument vector.
596 * \return EXIT_SUCCESS or EXIT_FAILURE.
598 int main(int argc
, char *argv
[])
602 sched
.default_timeout
.tv_sec
= 1;
603 sched
.select_function
= server_select
;
605 server_init(argc
, argv
);
606 mutex_lock(mmd_mutex
);
607 ret
= schedule(&sched
);
608 sched_shutdown(&sched
);
609 lls_free_parse_result(server_lpr
, CMD_PTR
);
610 if (server_lpr
!= cmdline_lpr
)
611 lls_free_parse_result(cmdline_lpr
, CMD_PTR
);
613 PARA_EMERG_LOG("%s\n", para_strerror(-ret
));
614 exit(ret
< 0? EXIT_FAILURE
: EXIT_SUCCESS
);