Pass full argument list to mood parsers.
[paraslash.git] / server.c
1 /*
2 * Copyright (C) 1997-2009 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 mood, \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, \ref ogg_afh.c, \ref aac_afh.c,
26 * - Decoders: \ref mp3dec_filter.c, \ref oggdec_filter.c, \ref aacdec_filter.c,
27 * - Volume normalizer: \ref compress_filter.c,
28 * - Output: \ref alsa_write.c, \ref osx_write.c,
29 * - http: \ref http_recv.c, \ref http_send.c,
30 * - udp: \ref udp_recv.c, \ref udp_send.c,
31 * - dccp: \ref dccp_recv.c, \ref dccp_send.c,
32 * - Audio file selector: \ref afs.c, \ref aft.c, \ref mood.c,
33 * - Afs structures: \ref afs_table, \ref audio_file_data,
34 * \ref afs_info \ref afh_info,
35 * - Afs tables: \ref aft.c, \ref mood.c, \ref playlist.c,
36 * \ref attribute.c, \ref score.c,
37 * - The virtual streaming system: \ref vss.c, \ref chunk_queue.c.
38 *
39 * Lower levels:
40 *
41 * - Scheduling: \ref sched.c, \ref sched.h,
42 * - Networking: \ref net.c,
43 * - File descriptors: \ref fd.c,
44 * - Signals: \ref signal.c,
45 * - Daemons: \ref daemon.c,
46 * - Strings: \ref string.c, \ref string.h,
47 * - Time: \ref time.c,
48 * - Spawning processes: \ref exec.c,
49 * - Inter process communication: \ref ipc.c,
50 * - Blob tables: \ref blob.c,
51 * - The error subssystem: \ref error.h.
52 * - Access control for paraslash senders: \ref acl.c, \ref acl.h.
53 *
54 * Low-level data structures:
55 *
56 * - Doubly linked lists: \ref list.h,
57 * - Ring buffer: \ref ringbuffer.c, \ref ringbuffer.h,
58 * - Hashing: \ref hash.h, \ref sha1.h, \ref sha1.c,
59 * - Crypto: \ref crypt.c.
60 * - Forward error correction: \ref fec.c
61 */
62
63 #include <signal.h>
64 #include <dirent.h>
65 #include <sys/time.h>
66 #include <openssl/rc4.h>
67 #include <osl.h>
68
69 #include "para.h"
70 #include "error.h"
71 #include "crypt.h"
72 #include "server.cmdline.h"
73 #include "afh.h"
74 #include "string.h"
75 #include "afs.h"
76 #include "server.h"
77 #include "vss.h"
78 #include "config.h"
79 #include "close_on_fork.h"
80 #include "list.h"
81 #include "send.h"
82 #include "net.h"
83 #include "daemon.h"
84 #include "ipc.h"
85 #include "fd.h"
86 #include "sched.h"
87 #include "signal.h"
88 #include "user_list.h"
89 #include "color.h"
90
91 /** Define the array of error lists needed by para_server. */
92 INIT_SERVER_ERRLISTS;
93
94 /** Shut down non-authorized connections after that many seconds. */
95 #define ALARM_TIMEOUT 10
96
97 /**
98 * Pointer to shared memory area for communication between para_server
99 * and its children. Exported to vss.c. command.c and to afs.
100 */
101 struct misc_meta_data *mmd;
102
103 /**
104 * The configuration of para_server
105 *
106 * It also contains the options for the audio file selector, audio format
107 * handler and all supported senders.
108 */
109 struct server_args_info conf;
110
111 /** A random value used in child context for authentication. */
112 uint32_t afs_socket_cookie;
113
114 /** The mutex protecting the shared memory area containing the mmd struct. */
115 int mmd_mutex;
116
117 /** The file containing user information (public key, permissions). */
118 static char *user_list_file = NULL;
119
120
121 /** The task responsible for server command handling. */
122 struct server_command_task {
123 /** TCP port on which para_server listens for connections. */
124 int listen_fd;
125 /** Copied from para_server's main function. */
126 int argc;
127 /** Argument vector passed to para_server's main function. */
128 char **argv;
129 /** The command task structure for scheduling. */
130 struct task task;
131 };
132
133 static int want_colors(void)
134 {
135 if (conf.color_arg == color_arg_no)
136 return 0;
137 if (conf.color_arg == color_arg_yes)
138 return 1;
139 if (conf.logfile_given)
140 return 0;
141 return isatty(STDERR_FILENO);
142 }
143
144 static void init_colors_or_die(void)
145 {
146 int ret, i;
147
148 if (!want_colors())
149 return;
150 daemon_set_flag(DF_COLOR_LOG);
151 daemon_set_default_log_colors();
152 for (i = 0; i < conf.log_color_given; i++) {
153 ret = daemon_set_log_color(conf.log_color_arg[i]);
154 if (ret < 0)
155 exit(EXIT_FAILURE);
156 }
157 }
158
159 /*
160 * setup shared memory area and get mutex for locking
161 */
162 static void init_ipc_or_die(void)
163 {
164 void *shm;
165 int shmid, ret = shm_new(sizeof(struct misc_meta_data));
166
167 if (ret < 0)
168 goto err_out;
169 shmid = ret;
170 ret = shm_attach(shmid, ATTACH_RW, &shm);
171 shm_destroy(shmid);
172 if (ret < 0)
173 goto err_out;
174 mmd = shm;
175
176 ret = mutex_new();
177 if (ret < 0)
178 goto err_out;
179 mmd_mutex = ret;
180
181 mmd->num_played = 0;
182 mmd->num_commands = 0;
183 mmd->events = 0;
184 mmd->num_connects = 0;
185 mmd->active_connections = 0;
186 mmd->vss_status_flags = VSS_NEXT;
187 mmd->new_vss_status_flags = VSS_NEXT;
188 return;
189 err_out:
190 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
191 exit(EXIT_FAILURE);
192 }
193
194 /**
195 * (Re-)read the server configuration files.
196 *
197 * \param override Passed to gengetopt to activate the override feature.
198 *
199 * This function also re-opens the logfile and sets the global \a
200 * user_list_file variable.
201 */
202 void parse_config_or_die(int override)
203 {
204 char *home = para_homedir();
205 int ret;
206 char *cf;
207
208 daemon_close_log();
209 if (conf.config_file_given)
210 cf = para_strdup(conf.config_file_arg);
211 else
212 cf = make_message("%s/.paraslash/server.conf", home);
213 free(user_list_file);
214 if (!conf.user_list_given)
215 user_list_file = make_message("%s/.paraslash/server.users", home);
216 else
217 user_list_file = para_strdup(conf.user_list_arg);
218 ret = file_exists(cf);
219 if (conf.config_file_given && !ret) {
220 ret = -1;
221 PARA_EMERG_LOG("can not read config file %s\n", cf);
222 goto out;
223 }
224 if (ret) {
225 int tmp = conf.daemon_given;
226 struct server_cmdline_parser_params params = {
227 .override = override,
228 .initialize = 0,
229 .check_required = 1,
230 .check_ambiguity = 0,
231 .print_errors = !conf.daemon_given
232 };
233 server_cmdline_parser_config_file(cf, &conf, &params);
234 conf.daemon_given = tmp;
235 }
236 if (conf.logfile_given) {
237 daemon_set_logfile(conf.logfile_arg);
238 daemon_open_log_or_die();
239 }
240 daemon_set_loglevel(conf.loglevel_arg);
241 init_colors_or_die();
242 daemon_set_flag(DF_LOG_PID);
243 daemon_set_flag(DF_LOG_LL);
244 daemon_set_flag(DF_LOG_TIME);
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, struct task *t)
275 {
276 struct signal_task *st = container_of(t, struct signal_task, task);
277
278 if (!FD_ISSET(st->fd, &s->rfds))
279 return;
280
281 st->signum = para_next_signal();
282 switch (st->signum) {
283 case SIGHUP:
284 handle_sighup();
285 break;
286 case SIGCHLD:
287 for (;;) {
288 pid_t pid;
289 int ret = para_reap_child(&pid);
290 if (ret <= 0)
291 break;
292 if (pid != mmd->afs_pid)
293 continue;
294 PARA_EMERG_LOG("fatal: afs died\n");
295 kill(0, SIGTERM);
296 goto cleanup;
297 }
298 break;
299 /* die on sigint/sigterm. Kill all children too. */
300 case SIGINT:
301 case SIGTERM:
302 PARA_EMERG_LOG("terminating on signal %d\n", st->signum);
303 kill(0, SIGTERM);
304 /*
305 * We must wait for afs because afs catches SIGINT/SIGTERM.
306 * Before reacting to the signal, afs might want to use the
307 * shared memory area and the mmd mutex. If we destroy this
308 * mutex too early and afs tries to lock the shared memory
309 * area, the call to mutex_lock() will fail and terminate the
310 * afs process. This leads to dirty osl tables.
311 *
312 * There's no such problem with the other children of the
313 * server process (the command handlers) as these reset their
314 * SIGINT/SIGTERM handlers to the default action, i.e. these
315 * processes get killed immediately by the above kill().
316 */
317 PARA_INFO_LOG("waiting for afs (pid %d) to die\n",
318 (int)mmd->afs_pid);
319 waitpid(mmd->afs_pid, NULL, 0);
320 cleanup:
321 free(mmd->afd.afhi.chunk_table);
322 close_listed_fds();
323 mutex_destroy(mmd_mutex);
324 shm_detach(mmd);
325 exit(EXIT_FAILURE);
326 }
327 }
328
329 static void init_signal_task(void)
330 {
331 static struct signal_task signal_task_struct,
332 *st = &signal_task_struct;
333
334 st->task.pre_select = signal_pre_select;
335 st->task.post_select = signal_post_select;
336 sprintf(st->task.status, "signal task");
337
338 PARA_NOTICE_LOG("setting up signal handling\n");
339 st->fd = para_signal_init(); /* always successful */
340 para_install_sighandler(SIGINT);
341 para_install_sighandler(SIGTERM);
342 para_install_sighandler(SIGHUP);
343 para_install_sighandler(SIGCHLD);
344 para_sigaction(SIGPIPE, SIG_IGN);
345 add_close_on_fork_list(st->fd);
346 register_task(&st->task);
347 }
348
349 static void command_pre_select(struct sched *s, struct task *t)
350 {
351 struct server_command_task *sct = container_of(t, struct server_command_task, task);
352 para_fd_set(sct->listen_fd, &s->rfds, &s->max_fileno);
353 }
354
355 static void command_post_select(struct sched *s, struct task *t)
356 {
357 struct server_command_task *sct = container_of(t, struct server_command_task, task);
358
359 int new_fd, ret, i;
360 char *peer_name;
361 pid_t child_pid;
362 uint32_t *chunk_table;
363
364 if (!FD_ISSET(sct->listen_fd, &s->rfds))
365 return;
366 ret = para_accept(sct->listen_fd, NULL, 0);
367 if (ret < 0)
368 goto out;
369 new_fd = ret;
370 peer_name = remote_name(new_fd);
371 PARA_INFO_LOG("got connection from %s, forking\n", peer_name);
372 mmd->num_connects++;
373 mmd->active_connections++;
374 /*
375 * The chunk table is a pointer located in the mmd struct that points
376 * to dynamically allocated memory, i.e. it must be freed by the parent
377 * and the child. However, as the mmd struct is in a shared memory
378 * area, there's no guarantee that after the fork this pointer is still
379 * valid in child context. As it is not used in the child anyway, we
380 * save it to a local variable before the fork and free the memory via
381 * that copy in the child directly after the fork.
382 */
383 chunk_table = mmd->afd.afhi.chunk_table;
384 child_pid = fork();
385 if (child_pid < 0) {
386 ret = -ERRNO_TO_PARA_ERROR(errno);
387 goto out;
388 }
389 if (child_pid) {
390 close(new_fd);
391 /* parent keeps accepting connections */
392 return;
393 }
394 /* mmd might already have changed at this point */
395 free(chunk_table);
396 alarm(ALARM_TIMEOUT);
397 close_listed_fds();
398 para_signal_shutdown();
399 /*
400 * put info on who we are serving into argv[0] to make
401 * client ip visible in top/ps
402 */
403 for (i = sct->argc - 1; i >= 0; i--)
404 memset(sct->argv[i], 0, strlen(sct->argv[i]));
405 sprintf(sct->argv[0], "para_server (serving %s)", peer_name);
406 return handle_connect(new_fd, peer_name);
407 out:
408 if (ret < 0)
409 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
410 }
411
412 static void init_server_command_task(int argc, char **argv)
413 {
414 int ret;
415 static struct server_command_task server_command_task_struct,
416 *sct = &server_command_task_struct;
417
418 PARA_NOTICE_LOG("initializing tcp command socket\n");
419 sct->task.pre_select = command_pre_select;
420 sct->task.post_select = command_post_select;
421 sct->argc = argc;
422 sct->argv = argv;
423 ret = para_listen(AF_UNSPEC, IPPROTO_TCP, conf.port_arg);
424 if (ret < 0)
425 goto err;
426 sct->listen_fd = ret;
427 ret = mark_fd_nonblocking(sct->listen_fd);
428 if (ret < 0)
429 goto err;
430 add_close_on_fork_list(sct->listen_fd); /* child doesn't need the listener */
431 register_task(&sct->task);
432 return;
433 err:
434 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
435 exit(EXIT_FAILURE);
436 }
437
438 static int init_afs(void)
439 {
440 int ret, afs_server_socket[2];
441
442 ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
443 if (ret < 0)
444 exit(EXIT_FAILURE);
445 get_random_bytes_or_die((unsigned char *)&afs_socket_cookie,
446 sizeof(afs_socket_cookie));
447 mmd->afs_pid = fork();
448 if (mmd->afs_pid < 0)
449 exit(EXIT_FAILURE);
450 if (!mmd->afs_pid) { /* child (afs) */
451 close(afs_server_socket[0]);
452 afs_init(afs_socket_cookie, afs_server_socket[1]);
453 }
454 close(afs_server_socket[1]);
455 ret = mark_fd_nonblocking(afs_server_socket[0]);
456 if (ret < 0)
457 exit(EXIT_FAILURE);
458 add_close_on_fork_list(afs_server_socket[0]);
459 PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n",
460 afs_server_socket[0], (unsigned) afs_socket_cookie);
461 return afs_server_socket[0];
462 }
463
464 __noreturn static void tmp_sigchld_handler(__a_unused int s)
465 {
466 PARA_EMERG_LOG("caught early SIGCHLD\n");
467 exit(EXIT_FAILURE);
468 }
469
470 static void server_init(int argc, char **argv)
471 {
472 struct server_cmdline_parser_params params = {
473 .override = 0,
474 .initialize = 1,
475 .check_required = 0,
476 .check_ambiguity = 0,
477 .print_errors = 1
478 };
479 int afs_socket;
480
481 valid_fd_012();
482 init_random_seed_or_die();
483 /* parse command line options */
484 server_cmdline_parser_ext(argc, argv, &conf, &params);
485 HANDLE_VERSION_FLAG("server", conf);
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 gettimeofday(now, NULL);
493 server_uptime(UPTIME_SET); /* reset server uptime */
494 init_user_list(user_list_file);
495 /* become daemon */
496 if (conf.daemon_given)
497 daemonize();
498 PARA_NOTICE_LOG("initializing audio format handlers\n");
499 afh_init();
500
501 /*
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
506 * good die young.
507 */
508 para_sigaction(SIGUSR1, SIG_IGN);
509 /*
510 * We have to install a SIGCHLD handler before the afs process is being
511 * forked off. Otherwise, para_server does not notice if afs dies before
512 * the SIGCHLD handler has been installed by init_signal_task() below.
513 */
514 para_sigaction(SIGCHLD, tmp_sigchld_handler);
515 PARA_NOTICE_LOG("initializing the audio file selector\n");
516 afs_socket = init_afs();
517 init_signal_task();
518 PARA_NOTICE_LOG("initializing virtual streaming system\n");
519 init_vss_task(afs_socket);
520 init_server_command_task(argc, argv);
521 PARA_NOTICE_LOG("server init complete\n");
522 }
523
524 static void status_refresh(void)
525 {
526 static int prev_uptime = -1, prev_events = -1;
527 int uptime = server_uptime(UPTIME_GET), ret = 1;
528
529 if (prev_events != mmd->events)
530 goto out;
531 if (mmd->new_vss_status_flags != mmd->vss_status_flags)
532 goto out_inc_events;
533 if (uptime / 60 != prev_uptime / 60)
534 goto out_inc_events;
535 return;
536 out_inc_events:
537 mmd->events++;
538 out:
539 prev_uptime = uptime;
540 prev_events = mmd->events;
541 mmd->vss_status_flags = mmd->new_vss_status_flags;
542 if (ret) {
543 PARA_DEBUG_LOG("%d events, forcing status update\n",
544 mmd->events);
545 killpg(0, SIGUSR1);
546 }
547 }
548
549 static int server_select(int max_fileno, fd_set *readfds, fd_set *writefds,
550 struct timeval *timeout_tv)
551 {
552 int ret;
553
554 status_refresh();
555 mutex_unlock(mmd_mutex);
556 ret = para_select(max_fileno + 1, readfds, writefds, timeout_tv);
557 mutex_lock(mmd_mutex);
558 return ret;
559 }
560
561 /**
562 * The main function of para_server.
563 *
564 * \param argc Usual argument count.
565 * \param argv Usual argument vector.
566 *
567 * \return EXIT_SUCCESS or EXIT_FAILURE.
568 */
569 int main(int argc, char *argv[])
570 {
571 int ret;
572 static struct sched s = {
573 .default_timeout = {
574 .tv_sec = 1,
575 .tv_usec = 0
576 },
577 .select_function = server_select
578 };
579 server_init(argc, argv);
580 mutex_lock(mmd_mutex);
581 ret = schedule(&s);
582 if (ret < 0) {
583 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
584 exit(EXIT_FAILURE);
585 }
586 exit(EXIT_SUCCESS);
587 }