2 * Copyright (C) 1997-2014 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file server.c Paraslash's main server. */
10 * \mainpage Main data structures:
12 * - Server: \ref server_command, \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.
20 * - Scheduling: \ref sched.h,
21 * - Buffer trees: \ref buffer_tree.h,
22 * - Sideband API: \ref sideband.h,
23 * - Crypto: \ref crypt.h, \ref crypt_backend.h,
24 * - Error subsystem: \ref error.h, \ref error2.c,
25 * - Inter process communication: \ref ipc.h,
26 * - Forward error correction: \ref fec.h,
27 * - Daemons: \ref daemon.h,
28 * - Mixer API: \ref mix.h,
29 * - Interactive sessions: \ref interactive.h,
30 * - File descriptors: \ref fd.h,
31 * - Signals: \ref signal.h,
32 * - Networking: \ref net.h,
33 * - Time: \ref time.c,
34 * - Doubly linked lists: \ref list.h.
37 #include <netinet/in.h>
38 #include <sys/socket.h>
42 #include <sys/types.h>
43 #include <arpa/inet.h>
50 #include "server.cmdline.h"
60 #include "close_on_fork.h"
66 #include "user_list.h"
71 __printf_2_3
void (*para_log
)(int, const char*, ...) = daemon_log
;
73 /** Define the array of error lists needed by para_server. */
76 /** Shut down non-authorized connections after that many seconds. */
77 #define ALARM_TIMEOUT 10
80 * Pointer to shared memory area for communication between para_server
81 * and its children. Exported to vss.c. command.c and to afs.
83 struct misc_meta_data
*mmd
;
86 * The configuration of para_server
88 * It also contains the options for the audio file selector, audio format
89 * handler and all supported senders.
91 struct server_args_info conf
;
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 /** The file containing user information (public key, permissions). */
100 static char *user_list_file
= NULL
;
102 static struct sched sched
;
104 /** The task responsible for server command handling. */
105 struct server_command_task
{
106 /** TCP port on which para_server listens for connections. */
108 /** Copied from para_server's main function. */
110 /** Argument vector passed to para_server's main function. */
112 /** The command task structure for scheduling. */
116 static int want_colors(void)
118 if (conf
.color_arg
== color_arg_no
)
120 if (conf
.color_arg
== color_arg_yes
)
122 if (conf
.logfile_given
)
124 return isatty(STDERR_FILENO
);
127 static void init_colors_or_die(void)
133 daemon_set_flag(DF_COLOR_LOG
);
134 daemon_set_default_log_colors();
135 for (i
= 0; i
< conf
.log_color_given
; i
++)
136 daemon_set_log_color_or_die(conf
.log_color_arg
[i
]);
140 * setup shared memory area and get mutex for locking
142 static void init_ipc_or_die(void)
145 int shmid
, ret
= shm_new(sizeof(struct misc_meta_data
));
150 ret
= shm_attach(shmid
, ATTACH_RW
, &shm
);
162 mmd
->num_commands
= 0;
164 mmd
->num_connects
= 0;
165 mmd
->active_connections
= 0;
166 mmd
->vss_status_flags
= VSS_NEXT
;
167 mmd
->new_vss_status_flags
= VSS_NEXT
;
170 PARA_EMERG_LOG("%s\n", para_strerror(-ret
));
175 * (Re-)read the server configuration files.
177 * \param override Passed to gengetopt to activate the override feature.
179 * This function also re-opens the logfile and sets the global \a
180 * user_list_file variable.
182 void parse_config_or_die(int override
)
184 char *home
= para_homedir();
189 if (conf
.config_file_given
)
190 cf
= para_strdup(conf
.config_file_arg
);
192 cf
= make_message("%s/.paraslash/server.conf", home
);
193 free(user_list_file
);
194 if (!conf
.user_list_given
)
195 user_list_file
= make_message("%s/.paraslash/server.users", home
);
197 user_list_file
= para_strdup(conf
.user_list_arg
);
198 ret
= file_exists(cf
);
199 if (conf
.config_file_given
&& !ret
) {
201 PARA_EMERG_LOG("can not read config file %s\n", cf
);
205 int tmp
= conf
.daemon_given
;
206 struct server_cmdline_parser_params params
= {
207 .override
= override
,
210 .check_ambiguity
= 0,
211 .print_errors
= !conf
.daemon_given
213 server_cmdline_parser_config_file(cf
, &conf
, ¶ms
);
214 daemon_set_loglevel(conf
.loglevel_arg
);
215 conf
.daemon_given
= tmp
;
217 if (conf
.logfile_given
) {
218 daemon_set_logfile(conf
.logfile_arg
);
219 daemon_open_log_or_die();
221 init_colors_or_die();
222 daemon_set_flag(DF_LOG_PID
);
223 daemon_set_flag(DF_LOG_LL
);
224 daemon_set_flag(DF_LOG_TIME
);
225 if (conf
.log_timing_given
)
226 daemon_set_flag(DF_LOG_TIMING
);
233 free(user_list_file
);
234 user_list_file
= NULL
;
238 static void signal_pre_select(struct sched
*s
, void *context
)
240 struct signal_task
*st
= context
;
241 para_fd_set(st
->fd
, &s
->rfds
, &s
->max_fileno
);
245 * called when server gets SIGHUP or when client invokes hup command.
247 static void handle_sighup(void)
249 PARA_NOTICE_LOG("SIGHUP\n");
250 parse_config_or_die(1); /* reopens log */
251 init_user_list(user_list_file
); /* reload user list */
253 kill(mmd
->afs_pid
, SIGHUP
);
256 static int signal_post_select(struct sched
*s
, __a_unused
void *context
)
258 int signum
= para_next_signal(&s
->rfds
);
269 int ret
= para_reap_child(&pid
);
272 if (pid
!= mmd
->afs_pid
)
274 PARA_EMERG_LOG("fatal: afs died\n");
279 /* die on sigint/sigterm. Kill all children too. */
282 PARA_EMERG_LOG("terminating on signal %d\n", signum
);
285 * We must wait for afs because afs catches SIGINT/SIGTERM.
286 * Before reacting to the signal, afs might want to use the
287 * shared memory area and the mmd mutex. If we destroy this
288 * mutex too early and afs tries to lock the shared memory
289 * area, the call to mutex_lock() will fail and terminate the
290 * afs process. This leads to dirty osl tables.
292 * There's no such problem with the other children of the
293 * server process (the command handlers) as these reset their
294 * SIGINT/SIGTERM handlers to the default action, i.e. these
295 * processes get killed immediately by the above kill().
297 PARA_INFO_LOG("waiting for afs (pid %d) to die\n",
299 waitpid(mmd
->afs_pid
, NULL
, 0);
301 free(mmd
->afd
.afhi
.chunk_table
);
303 mutex_destroy(mmd_mutex
);
310 static void init_signal_task(void)
312 static struct signal_task signal_task_struct
,
313 *st
= &signal_task_struct
;
315 PARA_NOTICE_LOG("setting up signal handling\n");
316 st
->fd
= para_signal_init(); /* always successful */
317 para_install_sighandler(SIGINT
);
318 para_install_sighandler(SIGTERM
);
319 para_install_sighandler(SIGHUP
);
320 para_install_sighandler(SIGCHLD
);
321 para_sigaction(SIGPIPE
, SIG_IGN
);
322 add_close_on_fork_list(st
->fd
);
323 st
->task
= task_register(&(struct task_info
) {
325 .pre_select
= signal_pre_select
,
326 .post_select
= signal_post_select
,
332 static void command_pre_select(struct sched
*s
, void *context
)
334 struct server_command_task
*sct
= context
;
335 para_fd_set(sct
->listen_fd
, &s
->rfds
, &s
->max_fileno
);
338 static int command_post_select(struct sched
*s
, void *context
)
340 struct server_command_task
*sct
= context
;
345 uint32_t *chunk_table
;
347 ret
= para_accept(sct
->listen_fd
, &s
->rfds
, NULL
, 0, &new_fd
);
350 peer_name
= remote_name(new_fd
);
351 PARA_INFO_LOG("got connection from %s, forking\n", peer_name
);
353 mmd
->active_connections
++;
355 * The chunk table is a pointer located in the mmd struct that points
356 * to dynamically allocated memory, i.e. it must be freed by the parent
357 * and the child. However, as the mmd struct is in a shared memory
358 * area, there's no guarantee that after the fork this pointer is still
359 * valid in child context. As it is not used in the child anyway, we
360 * save it to a local variable before the fork and free the memory via
361 * that copy in the child directly after the fork.
363 chunk_table
= mmd
->afd
.afhi
.chunk_table
;
366 ret
= -ERRNO_TO_PARA_ERROR(errno
);
370 /* avoid problems with non-fork-safe PRNGs */
371 unsigned char buf
[16];
372 get_random_bytes_or_die(buf
, sizeof(buf
));
374 /* parent keeps accepting connections */
377 /* mmd might already have changed at this point */
379 alarm(ALARM_TIMEOUT
);
381 para_signal_shutdown();
383 * put info on who we are serving into argv[0] to make
384 * client ip visible in top/ps
386 for (i
= sct
->argc
- 1; i
>= 0; i
--)
387 memset(sct
->argv
[i
], 0, strlen(sct
->argv
[i
]));
388 sprintf(sct
->argv
[0], "para_server (serving %s)", peer_name
);
389 handle_connect(new_fd
, peer_name
);
393 PARA_CRIT_LOG("%s\n", para_strerror(-ret
));
397 static void init_server_command_task(int argc
, char **argv
)
400 static struct server_command_task server_command_task_struct
,
401 *sct
= &server_command_task_struct
;
403 PARA_NOTICE_LOG("initializing tcp command socket\n");
406 ret
= para_listen_simple(IPPROTO_TCP
, conf
.port_arg
);
409 sct
->listen_fd
= ret
;
410 ret
= mark_fd_nonblocking(sct
->listen_fd
);
413 add_close_on_fork_list(sct
->listen_fd
); /* child doesn't need the listener */
414 sct
->task
= task_register(&(struct task_info
) {
415 .name
= "server command",
416 .pre_select
= command_pre_select
,
417 .post_select
= command_post_select
,
422 PARA_EMERG_LOG("%s\n", para_strerror(-ret
));
426 static int init_afs(int argc
, char **argv
)
428 int ret
, afs_server_socket
[2];
431 ret
= socketpair(PF_UNIX
, SOCK_DGRAM
, 0, afs_server_socket
);
434 get_random_bytes_or_die((unsigned char *)&afs_socket_cookie
,
435 sizeof(afs_socket_cookie
));
439 if (afs_pid
== 0) { /* child (afs) */
441 for (i
= argc
- 1; i
>= 0; i
--)
442 memset(argv
[i
], 0, strlen(argv
[i
]));
443 sprintf(argv
[0], "para_server (afs)");
444 close(afs_server_socket
[0]);
445 afs_init(afs_socket_cookie
, afs_server_socket
[1]);
447 mmd
->afs_pid
= afs_pid
;
448 close(afs_server_socket
[1]);
449 ret
= mark_fd_nonblocking(afs_server_socket
[0]);
452 add_close_on_fork_list(afs_server_socket
[0]);
453 PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n",
454 afs_server_socket
[0], (unsigned) afs_socket_cookie
);
455 return afs_server_socket
[0];
458 __noreturn
static void print_help_and_die(void)
460 struct ggo_help h
= DEFINE_GGO_HELP(server
);
461 bool d
= conf
.detailed_help_given
;
463 ggo_print_help(&h
, d
? GPH_STANDARD_FLAGS_DETAILED
: GPH_STANDARD_FLAGS
);
467 static void server_init(int argc
, char **argv
)
469 struct server_cmdline_parser_params params
= {
473 .check_ambiguity
= 0,
479 init_random_seed_or_die();
480 /* parse command line options */
481 server_cmdline_parser_ext(argc
, argv
, &conf
, ¶ms
);
482 daemon_set_loglevel(conf
.loglevel_arg
);
483 version_handle_flag("server", conf
.version_given
);
484 if (conf
.help_given
|| conf
.detailed_help_given
)
485 print_help_and_die();
486 drop_privileges_or_die(conf
.user_arg
, conf
.group_arg
);
487 /* parse config file, open log and set defaults */
488 parse_config_or_die(0);
489 log_welcome("para_server");
490 init_ipc_or_die(); /* init mmd struct and mmd->lock */
491 /* make sure, the global now pointer is uptodate */
492 clock_get_realtime(now
);
493 set_server_start_time(now
);
494 init_user_list(user_list_file
);
496 if (conf
.daemon_given
)
497 daemonize(true /* parent waits for SIGTERM */);
498 PARA_NOTICE_LOG("initializing audio format handlers\n");
502 * Although afs uses its own signal handling we must ignore SIGUSR1
503 * _before_ the afs child process gets born by init_afs() below. It's
504 * racy to do this in the child because the parent might send SIGUSR1
505 * before the child gets a chance to ignore this signal -- only the
508 para_sigaction(SIGUSR1
, SIG_IGN
);
510 * We have to block SIGCHLD before the afs process is being forked off.
511 * Otherwise, para_server does not notice if afs dies before the
512 * SIGCHLD handler has been installed for the parent process by
513 * init_signal_task() below.
515 para_block_signal(SIGCHLD
);
516 PARA_NOTICE_LOG("initializing the audio file selector\n");
517 afs_socket
= init_afs(argc
, argv
);
519 para_unblock_signal(SIGCHLD
);
520 PARA_NOTICE_LOG("initializing virtual streaming system\n");
521 init_vss_task(afs_socket
, &sched
);
522 init_server_command_task(argc
, argv
);
523 if (conf
.daemon_given
)
524 kill(getppid(), SIGTERM
);
525 PARA_NOTICE_LOG("server init complete\n");
528 static void status_refresh(void)
530 static int prev_uptime
= -1, prev_events
= -1;
531 int uptime
= get_server_uptime(now
);
533 if (prev_events
!= mmd
->events
)
535 if (mmd
->new_vss_status_flags
!= mmd
->vss_status_flags
)
537 if (uptime
/ 60 != prev_uptime
/ 60)
543 prev_uptime
= uptime
;
544 prev_events
= mmd
->events
;
545 mmd
->vss_status_flags
= mmd
->new_vss_status_flags
;
546 PARA_DEBUG_LOG("%d events, forcing status update\n", mmd
->events
);
550 static int server_select(int max_fileno
, fd_set
*readfds
, fd_set
*writefds
,
551 struct timeval
*timeout_tv
)
556 mutex_unlock(mmd_mutex
);
557 ret
= para_select(max_fileno
+ 1, readfds
, writefds
, timeout_tv
);
558 mutex_lock(mmd_mutex
);
563 * The main function of para_server.
565 * \param argc Usual argument count.
566 * \param argv Usual argument vector.
568 * \return EXIT_SUCCESS or EXIT_FAILURE.
570 int main(int argc
, char *argv
[])
574 sched
.default_timeout
.tv_sec
= 1;
575 sched
.select_function
= server_select
;
577 server_init(argc
, argv
);
578 mutex_lock(mmd_mutex
);
579 ret
= schedule(&sched
);
580 sched_shutdown(&sched
);
582 PARA_EMERG_LOG("%s\n", para_strerror(-ret
));