Remove some unnecessary includes.
[paraslash.git] / server.c
1 /*
2 * Copyright (C) 1997-2011 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file server.c Paraslash's main server. */
8
9
10 /**
11 * \mainpage Paraslash API Reference
12 *
13 * Starting points for getting an overview:
14 *
15 *
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.
21 *
22 *
23 * The gory details, listed by topic:
24 *
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.
40 *
41 * Lower levels:
42 *
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.
55 *
56 * Low-level data structures:
57 *
58 * - Doubly linked lists: \ref list.h,
59 * - Ring buffer: \ref ringbuffer.c, \ref ringbuffer.h,
60 * - Crypto: \ref crypt.c, \ref crypt.h.
61 * - Forward error correction: \ref fec.c.
62 */
63
64 #include <signal.h>
65 #include <sys/time.h>
66 #include <regex.h>
67 #include <osl.h>
68 #include <stdbool.h>
69
70 #include "para.h"
71 #include "error.h"
72 #include "crypt.h"
73 #include "server.cmdline.h"
74 #include "afh.h"
75 #include "string.h"
76 #include "afs.h"
77 #include "server.h"
78 #include "list.h"
79 #include "send.h"
80 #include "vss.h"
81 #include "config.h"
82 #include "close_on_fork.h"
83 #include "net.h"
84 #include "daemon.h"
85 #include "ipc.h"
86 #include "fd.h"
87 #include "sched.h"
88 #include "signal.h"
89 #include "user_list.h"
90 #include "color.h"
91
92 /** Define the array of error lists needed by para_server. */
93 INIT_SERVER_ERRLISTS;
94
95 /** Shut down non-authorized connections after that many seconds. */
96 #define ALARM_TIMEOUT 10
97
98 /**
99 * Pointer to shared memory area for communication between para_server
100 * and its children. Exported to vss.c. command.c and to afs.
101 */
102 struct misc_meta_data *mmd;
103
104 /**
105 * The configuration of para_server
106 *
107 * It also contains the options for the audio file selector, audio format
108 * handler and all supported senders.
109 */
110 struct server_args_info conf;
111
112 /** A random value used in child context for authentication. */
113 uint32_t afs_socket_cookie;
114
115 /** The mutex protecting the shared memory area containing the mmd struct. */
116 int mmd_mutex;
117
118 /** The file containing user information (public key, permissions). */
119 static char *user_list_file = NULL;
120
121
122 /** The task responsible for server command handling. */
123 struct server_command_task {
124 /** TCP port on which para_server listens for connections. */
125 int listen_fd;
126 /** Copied from para_server's main function. */
127 int argc;
128 /** Argument vector passed to para_server's main function. */
129 char **argv;
130 /** The command task structure for scheduling. */
131 struct task task;
132 };
133
134 static int want_colors(void)
135 {
136 if (conf.color_arg == color_arg_no)
137 return 0;
138 if (conf.color_arg == color_arg_yes)
139 return 1;
140 if (conf.logfile_given)
141 return 0;
142 return isatty(STDERR_FILENO);
143 }
144
145 static void init_colors_or_die(void)
146 {
147 int i;
148
149 if (!want_colors())
150 return;
151 daemon_set_flag(DF_COLOR_LOG);
152 daemon_set_default_log_colors();
153 for (i = 0; i < conf.log_color_given; i++)
154 daemon_set_log_color_or_die(conf.log_color_arg[i]);
155 }
156
157 /*
158 * setup shared memory area and get mutex for locking
159 */
160 static void init_ipc_or_die(void)
161 {
162 void *shm;
163 int shmid, ret = shm_new(sizeof(struct misc_meta_data));
164
165 if (ret < 0)
166 goto err_out;
167 shmid = ret;
168 ret = shm_attach(shmid, ATTACH_RW, &shm);
169 shm_destroy(shmid);
170 if (ret < 0)
171 goto err_out;
172 mmd = shm;
173
174 ret = mutex_new();
175 if (ret < 0)
176 goto err_out;
177 mmd_mutex = ret;
178
179 mmd->num_played = 0;
180 mmd->num_commands = 0;
181 mmd->events = 0;
182 mmd->num_connects = 0;
183 mmd->active_connections = 0;
184 mmd->vss_status_flags = VSS_NEXT;
185 mmd->new_vss_status_flags = VSS_NEXT;
186 return;
187 err_out:
188 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
189 exit(EXIT_FAILURE);
190 }
191
192 /**
193 * (Re-)read the server configuration files.
194 *
195 * \param override Passed to gengetopt to activate the override feature.
196 *
197 * This function also re-opens the logfile and sets the global \a
198 * user_list_file variable.
199 */
200 void parse_config_or_die(int override)
201 {
202 char *home = para_homedir();
203 int ret;
204 char *cf;
205
206 daemon_close_log();
207 if (conf.config_file_given)
208 cf = para_strdup(conf.config_file_arg);
209 else
210 cf = make_message("%s/.paraslash/server.conf", home);
211 free(user_list_file);
212 if (!conf.user_list_given)
213 user_list_file = make_message("%s/.paraslash/server.users", home);
214 else
215 user_list_file = para_strdup(conf.user_list_arg);
216 ret = file_exists(cf);
217 if (conf.config_file_given && !ret) {
218 ret = -1;
219 PARA_EMERG_LOG("can not read config file %s\n", cf);
220 goto out;
221 }
222 if (ret) {
223 int tmp = conf.daemon_given;
224 struct server_cmdline_parser_params params = {
225 .override = override,
226 .initialize = 0,
227 .check_required = 1,
228 .check_ambiguity = 0,
229 .print_errors = !conf.daemon_given
230 };
231 server_cmdline_parser_config_file(cf, &conf, &params);
232 conf.daemon_given = tmp;
233 }
234 if (conf.logfile_given) {
235 daemon_set_logfile(conf.logfile_arg);
236 daemon_open_log_or_die();
237 }
238 daemon_set_loglevel(conf.loglevel_arg);
239 init_colors_or_die();
240 daemon_set_flag(DF_LOG_PID);
241 daemon_set_flag(DF_LOG_LL);
242 daemon_set_flag(DF_LOG_TIME);
243 if (conf.log_timing_given)
244 daemon_set_flag(DF_LOG_TIMING);
245 ret = 1;
246 out:
247 free(cf);
248 free(home);
249 if (ret > 0)
250 return;
251 free(user_list_file);
252 user_list_file = NULL;
253 exit(EXIT_FAILURE);
254 }
255
256 static void signal_pre_select(struct sched *s, struct task *t)
257 {
258 struct signal_task *st = container_of(t, struct signal_task, task);
259 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
260 }
261
262 /*
263 * called when server gets SIGHUP or when client invokes hup command.
264 */
265 static void handle_sighup(void)
266 {
267 PARA_NOTICE_LOG("SIGHUP\n");
268 parse_config_or_die(1); /* reopens log */
269 init_user_list(user_list_file); /* reload user list */
270 if (mmd->afs_pid)
271 kill(mmd->afs_pid, SIGHUP);
272 }
273
274 static void signal_post_select(struct sched *s, __a_unused struct task *t)
275 {
276 int signum = para_next_signal(&s->rfds);
277
278 switch (signum) {
279 case 0:
280 return;
281 case SIGHUP:
282 handle_sighup();
283 break;
284 case SIGCHLD:
285 for (;;) {
286 pid_t pid;
287 int ret = para_reap_child(&pid);
288 if (ret <= 0)
289 break;
290 if (pid != mmd->afs_pid)
291 continue;
292 PARA_EMERG_LOG("fatal: afs died\n");
293 kill(0, SIGTERM);
294 goto cleanup;
295 }
296 break;
297 /* die on sigint/sigterm. Kill all children too. */
298 case SIGINT:
299 case SIGTERM:
300 PARA_EMERG_LOG("terminating on signal %d\n", signum);
301 kill(0, SIGTERM);
302 /*
303 * We must wait for afs because afs catches SIGINT/SIGTERM.
304 * Before reacting to the signal, afs might want to use the
305 * shared memory area and the mmd mutex. If we destroy this
306 * mutex too early and afs tries to lock the shared memory
307 * area, the call to mutex_lock() will fail and terminate the
308 * afs process. This leads to dirty osl tables.
309 *
310 * There's no such problem with the other children of the
311 * server process (the command handlers) as these reset their
312 * SIGINT/SIGTERM handlers to the default action, i.e. these
313 * processes get killed immediately by the above kill().
314 */
315 PARA_INFO_LOG("waiting for afs (pid %d) to die\n",
316 (int)mmd->afs_pid);
317 waitpid(mmd->afs_pid, NULL, 0);
318 cleanup:
319 free(mmd->afd.afhi.chunk_table);
320 close_listed_fds();
321 mutex_destroy(mmd_mutex);
322 shm_detach(mmd);
323 exit(EXIT_FAILURE);
324 }
325 }
326
327 static void init_signal_task(void)
328 {
329 static struct signal_task signal_task_struct,
330 *st = &signal_task_struct;
331
332 st->task.pre_select = signal_pre_select;
333 st->task.post_select = signal_post_select;
334 sprintf(st->task.status, "signal task");
335
336 PARA_NOTICE_LOG("setting up signal handling\n");
337 st->fd = para_signal_init(); /* always successful */
338 para_install_sighandler(SIGINT);
339 para_install_sighandler(SIGTERM);
340 para_install_sighandler(SIGHUP);
341 para_install_sighandler(SIGCHLD);
342 para_sigaction(SIGPIPE, SIG_IGN);
343 add_close_on_fork_list(st->fd);
344 register_task(&st->task);
345 }
346
347 static void command_pre_select(struct sched *s, struct task *t)
348 {
349 struct server_command_task *sct = container_of(t, struct server_command_task, task);
350 para_fd_set(sct->listen_fd, &s->rfds, &s->max_fileno);
351 }
352
353 static void command_post_select(struct sched *s, struct task *t)
354 {
355 struct server_command_task *sct = container_of(t, struct server_command_task, task);
356
357 int new_fd, ret, i;
358 char *peer_name;
359 pid_t child_pid;
360 uint32_t *chunk_table;
361
362 ret = para_accept(sct->listen_fd, &s->rfds, NULL, 0, &new_fd);
363 if (ret <= 0)
364 goto out;
365 peer_name = remote_name(new_fd);
366 PARA_INFO_LOG("got connection from %s, forking\n", peer_name);
367 mmd->num_connects++;
368 mmd->active_connections++;
369 /*
370 * The chunk table is a pointer located in the mmd struct that points
371 * to dynamically allocated memory, i.e. it must be freed by the parent
372 * and the child. However, as the mmd struct is in a shared memory
373 * area, there's no guarantee that after the fork this pointer is still
374 * valid in child context. As it is not used in the child anyway, we
375 * save it to a local variable before the fork and free the memory via
376 * that copy in the child directly after the fork.
377 */
378 chunk_table = mmd->afd.afhi.chunk_table;
379 child_pid = fork();
380 if (child_pid < 0) {
381 ret = -ERRNO_TO_PARA_ERROR(errno);
382 goto out;
383 }
384 if (child_pid) {
385 close(new_fd);
386 /* parent keeps accepting connections */
387 return;
388 }
389 /* mmd might already have changed at this point */
390 free(chunk_table);
391 alarm(ALARM_TIMEOUT);
392 close_listed_fds();
393 para_signal_shutdown();
394 /*
395 * put info on who we are serving into argv[0] to make
396 * client ip visible in top/ps
397 */
398 for (i = sct->argc - 1; i >= 0; i--)
399 memset(sct->argv[i], 0, strlen(sct->argv[i]));
400 sprintf(sct->argv[0], "para_server (serving %s)", peer_name);
401 return handle_connect(new_fd, peer_name);
402 out:
403 if (ret < 0)
404 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
405 }
406
407 static void init_server_command_task(int argc, char **argv)
408 {
409 int ret;
410 static struct server_command_task server_command_task_struct,
411 *sct = &server_command_task_struct;
412
413 PARA_NOTICE_LOG("initializing tcp command socket\n");
414 sct->task.pre_select = command_pre_select;
415 sct->task.post_select = command_post_select;
416 sct->argc = argc;
417 sct->argv = argv;
418 ret = para_listen_simple(IPPROTO_TCP, conf.port_arg);
419 if (ret < 0)
420 goto err;
421 sct->listen_fd = ret;
422 ret = mark_fd_nonblocking(sct->listen_fd);
423 if (ret < 0)
424 goto err;
425 add_close_on_fork_list(sct->listen_fd); /* child doesn't need the listener */
426 sprintf(sct->task.status, "server command task");
427 register_task(&sct->task);
428 return;
429 err:
430 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
431 exit(EXIT_FAILURE);
432 }
433
434 static int init_afs(void)
435 {
436 int ret, afs_server_socket[2];
437 pid_t afs_pid;
438
439 ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
440 if (ret < 0)
441 exit(EXIT_FAILURE);
442 get_random_bytes_or_die((unsigned char *)&afs_socket_cookie,
443 sizeof(afs_socket_cookie));
444 afs_pid = fork();
445 if (afs_pid < 0)
446 exit(EXIT_FAILURE);
447 if (afs_pid == 0) { /* child (afs) */
448 close(afs_server_socket[0]);
449 afs_init(afs_socket_cookie, afs_server_socket[1]);
450 }
451 mmd->afs_pid = afs_pid;
452 close(afs_server_socket[1]);
453 ret = mark_fd_nonblocking(afs_server_socket[0]);
454 if (ret < 0)
455 exit(EXIT_FAILURE);
456 add_close_on_fork_list(afs_server_socket[0]);
457 PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n",
458 afs_server_socket[0], (unsigned) afs_socket_cookie);
459 return afs_server_socket[0];
460 }
461
462 __noreturn static void tmp_sigchld_handler(__a_unused int s)
463 {
464 PARA_EMERG_LOG("caught early SIGCHLD\n");
465 exit(EXIT_FAILURE);
466 }
467
468 static void server_init(int argc, char **argv)
469 {
470 struct server_cmdline_parser_params params = {
471 .override = 0,
472 .initialize = 1,
473 .check_required = 0,
474 .check_ambiguity = 0,
475 .print_errors = 1
476 };
477 int afs_socket;
478
479 valid_fd_012();
480 init_random_seed_or_die();
481 /* parse command line options */
482 server_cmdline_parser_ext(argc, argv, &conf, &params);
483 HANDLE_VERSION_FLAG("server", conf);
484 drop_privileges_or_die(conf.user_arg, conf.group_arg);
485 /* parse config file, open log and set defaults */
486 parse_config_or_die(0);
487 log_welcome("para_server");
488 init_ipc_or_die(); /* init mmd struct and mmd->lock */
489 /* make sure, the global now pointer is uptodate */
490 gettimeofday(now, NULL);
491 server_uptime(UPTIME_SET); /* reset server uptime */
492 init_user_list(user_list_file);
493 /* become daemon */
494 if (conf.daemon_given)
495 daemonize();
496 PARA_NOTICE_LOG("initializing audio format handlers\n");
497 afh_init();
498
499 /*
500 * Although afs uses its own signal handling we must ignore SIGUSR1
501 * _before_ the afs child process gets born by init_afs() below. It's
502 * racy to do this in the child because the parent might send SIGUSR1
503 * before the child gets a chance to ignore this signal -- only the
504 * good die young.
505 */
506 para_sigaction(SIGUSR1, SIG_IGN);
507 /*
508 * We have to install a SIGCHLD handler before the afs process is being
509 * forked off. Otherwise, para_server does not notice if afs dies before
510 * the SIGCHLD handler has been installed by init_signal_task() below.
511 */
512 para_sigaction(SIGCHLD, tmp_sigchld_handler);
513 PARA_NOTICE_LOG("initializing the audio file selector\n");
514 afs_socket = init_afs();
515 init_signal_task();
516 PARA_NOTICE_LOG("initializing virtual streaming system\n");
517 init_vss_task(afs_socket);
518 init_server_command_task(argc, argv);
519 PARA_NOTICE_LOG("server init complete\n");
520 }
521
522 static void status_refresh(void)
523 {
524 static int prev_uptime = -1, prev_events = -1;
525 int uptime = server_uptime(UPTIME_GET), ret = 1;
526
527 if (prev_events != mmd->events)
528 goto out;
529 if (mmd->new_vss_status_flags != mmd->vss_status_flags)
530 goto out_inc_events;
531 if (uptime / 60 != prev_uptime / 60)
532 goto out_inc_events;
533 return;
534 out_inc_events:
535 mmd->events++;
536 out:
537 prev_uptime = uptime;
538 prev_events = mmd->events;
539 mmd->vss_status_flags = mmd->new_vss_status_flags;
540 if (ret) {
541 PARA_DEBUG_LOG("%d events, forcing status update\n",
542 mmd->events);
543 killpg(0, SIGUSR1);
544 }
545 }
546
547 static int server_select(int max_fileno, fd_set *readfds, fd_set *writefds,
548 struct timeval *timeout_tv)
549 {
550 int ret;
551
552 status_refresh();
553 mutex_unlock(mmd_mutex);
554 ret = para_select(max_fileno + 1, readfds, writefds, timeout_tv);
555 mutex_lock(mmd_mutex);
556 return ret;
557 }
558
559 /**
560 * The main function of para_server.
561 *
562 * \param argc Usual argument count.
563 * \param argv Usual argument vector.
564 *
565 * \return EXIT_SUCCESS or EXIT_FAILURE.
566 */
567 int main(int argc, char *argv[])
568 {
569 int ret;
570 static struct sched s = {
571 .default_timeout = {
572 .tv_sec = 1,
573 .tv_usec = 0
574 },
575 .select_function = server_select
576 };
577 server_init(argc, argv);
578 mutex_lock(mmd_mutex);
579 ret = schedule(&s);
580 if (ret < 0) {
581 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
582 exit(EXIT_FAILURE);
583 }
584 exit(EXIT_SUCCESS);
585 }