doxgen: Kill double /ref.
[paraslash.git] / server.c
1 /*
2 * Copyright (C) 1997-2007 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 are
14 *
15 * probably:
16 *
17 * - The main programs: \ref server.c, \ref audiod.c, \ref client.c,
18 * \ref audioc.c, \ref fsck.c,
19 * - Server: \ref server_command, \ref sender,
20 * - Audio file selector: \ref audio_format_handler, \ref mood, \ref afs_table,
21 * - Client: \ref receiver, \ref receiver_node, \ref filter, \ref filter_node.
22 *
23 *
24 * The gory details, listed by topic:
25 *
26 * - Audio format handlers: \ref mp3_afh.c, \ref ogg_afh.c, \ref aac_afh.c,
27 * - Decoders: \ref mp3dec.c, \ref oggdec.c, \ref aacdec.c,
28 * - Volume normalizer: \ref compress.c,
29 * - Output: \ref alsa_write.c, \ref osx_write.c,
30 * - http: \ref http_recv.c, \ref http_send.c,
31 * - ortp: \ref ortp_recv.c, \ref ortp_send.c,
32 * - dccp: \ref dccp_recv.c, \ref dccp_send.c,
33 * - Audio file selector: \ref afs.c, \ref aft.c, \ref mood.c,
34 * - Afs structures: \ref afs_table, \ref audio_file_data,
35 * \ref afs_info \ref afh_info,
36 * - Afs tables: \ref aft.c, \ref mood.c, \ref playlist.c,
37 * \ref attribute.c, \ref score.c,
38 * - The virtual streaming system: \ref vss.c, \ref chunk_queue.c.
39 *
40 * Lower levels:
41 *
42 * - Scheduling: \ref sched.c, \ref sched.h,
43 * - Networking: \ref net.c,
44 * - File descriptors: \ref fd.c,
45 * - Signals: \ref signal.c,
46 * - Daemons: \ref daemon.c,
47 * - Strings: \ref string.c, \ref string.h,
48 * - Time: \ref time.c,
49 * - Spawning processes: \ref exec.c,
50 * - Inter process communication: \ref ipc.c,
51 * - The object storage layer: \ref osl.c,
52 * - Blob tables: \ref blob.c,
53 * - The error subssystem: \ref error.h.
54 *
55 * Low-level data structures:
56 *
57 * - Doubly linked lists: \ref list.h,
58 * - Red-black trees: \ref rbtree.h, \ref rbtree.c,
59 * - Ring buffer: \ref ringbuffer.c, \ref ringbuffer.h,
60 * - Hashing: \ref hash.h, \ref sha1.h, \ref sha1.c,
61 * - Crypto: \ref crypt.c.
62 *
63 */
64
65 #include <signal.h>
66 #include <sys/types.h>
67 #include <dirent.h>
68
69 #include "para.h"
70 #include "error.h"
71 #include "server.cmdline.h"
72 #include "afh.h"
73 #include "string.h"
74 #include "afs.h"
75 #include "server.h"
76 #include "vss.h"
77 #include "config.h"
78 #include "close_on_fork.h"
79 #include "send.h"
80 #include "net.h"
81 #include "daemon.h"
82 #include "ipc.h"
83 #include "fd.h"
84 #include "list.h"
85 #include "sched.h"
86 #include "signal.h"
87 #include "user_list.h"
88
89 /** define the array of error lists needed by para_server */
90 INIT_SERVER_ERRLISTS;
91
92 /** shut down non-authorized connections after that many seconds */
93 #define ALARM_TIMEOUT 10
94
95 /**
96 * Pointer to shared memory area for communication between para_server
97 * and its children. Exported to vss.c. command.c and to afs.
98 */
99 struct misc_meta_data *mmd;
100
101 /**
102 * the configuration of para_server
103 *
104 * It also contains the options for the audio file selector, audio format
105 * handler and all supported senders.
106 */
107 struct server_args_info conf;
108
109 /** the file containing user information (public key, permissions) */
110 char *user_list_file = NULL;
111
112 extern void dccp_send_init(struct sender *);
113 extern void http_send_init(struct sender *);
114 extern void ortp_send_init(struct sender *);
115
116 /** the list of supported senders */
117 struct sender senders[] = {
118 {
119 .name = "http",
120 .init = http_send_init,
121 },
122 {
123 .name = "dccp",
124 .init = dccp_send_init,
125 },
126 #ifdef HAVE_ORTP
127 {
128 .name = "ortp",
129 .init = ortp_send_init,
130 },
131 #endif
132 {
133 .name = NULL,
134 }
135 };
136
137
138 /* global variables for server-internal use */
139 static FILE *logfile;
140 static int mmd_mutex, mmd_shm_id;
141 static int signal_pipe;
142
143 /**
144 * para_server's log function
145 *
146 * \param ll the log level
147 * \param fmt the format string describing the log message
148 */
149 void para_log(int ll, const char* fmt,...)
150 {
151 va_list argp;
152 FILE *outfd;
153 struct tm *tm;
154 time_t t1;
155 char str[MAXLINE] = "";
156 pid_t mypid;
157
158 if (ll < conf.loglevel_arg)
159 return;
160 outfd = logfile? logfile : stderr;
161 time(&t1);
162 tm = localtime(&t1);
163 strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
164 fprintf(outfd, "%s ", str);
165 if (conf.loglevel_arg <= INFO)
166 fprintf(outfd, "%i: ", ll);
167 mypid = getpid();
168 if (conf.loglevel_arg <= INFO)
169 fprintf(outfd, "(%d) ", mypid);
170 va_start(argp, fmt);
171 vfprintf(outfd, fmt, argp);
172 va_end(argp);
173 }
174
175 /*
176 * setup shared memory area and get mutex for locking
177 */
178 static void shm_init(void)
179 {
180 void *shm;
181 int ret = shm_new(sizeof(struct misc_meta_data));
182
183 if (ret < 0)
184 goto err_out;
185
186 ret = shm_attach(ret, ATTACH_RW, &shm);
187 if (ret < 0)
188 goto err_out;
189 mmd = shm;
190 mmd_shm_id = ret;
191
192 ret = mutex_new();
193 if (ret < 0)
194 goto err_out;
195 mmd_mutex = ret;
196
197 mmd->num_played = 0;
198 mmd->num_commands = 0;
199 mmd->events = 0;
200 mmd->num_connects = 0;
201 mmd->active_connections = 0;
202 strcpy(mmd->afd.path, "(none)");
203 mmd->vss_status_flags = VSS_NEXT;
204 mmd->new_vss_status_flags = VSS_NEXT;
205 mmd->sender_cmd_data.cmd_num = -1;
206 return;
207 err_out:
208 PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
209 exit(EXIT_FAILURE);
210 }
211
212 /**
213 * lock the shared memory area containing the mmd struct
214 *
215 * \sa semop(2), struct misc_meta_data.
216 */
217 void mmd_lock(void)
218 {
219 mutex_lock(mmd_mutex);
220 }
221
222 /**
223 * unlock the shared memory area containing the mmd struct
224 *
225 * \sa semop(2), struct misc_meta_data
226 */
227
228 void mmd_unlock(void)
229 {
230 mutex_unlock(mmd_mutex);
231 }
232
233 static void parse_config(int override)
234 {
235 char *home = para_homedir();
236 struct stat statbuf;
237 int ret;
238 char *cf;
239
240 if (conf.config_file_given)
241 cf = para_strdup(conf.config_file_arg);
242 else
243 cf = make_message("%s/.paraslash/server.conf", home);
244 free(user_list_file);
245 if (!conf.user_list_given)
246 user_list_file = make_message("%s/.paraslash/server.users", home);
247 else
248 user_list_file = para_strdup(conf.user_list_arg);
249 ret = stat(cf, &statbuf);
250 if (ret && conf.config_file_given) {
251 ret = -1;
252 PARA_EMERG_LOG("can not stat config file %s\n", cf);
253 goto out;
254 }
255 if (!ret) {
256 int tmp = conf.daemon_given;
257 struct server_cmdline_parser_params params = {
258 .override = override,
259 .initialize = 0,
260 .check_required = 0,
261 .check_ambiguity = 0
262 };
263 server_cmdline_parser_config_file(cf, &conf, &params);
264 conf.daemon_given = tmp;
265 }
266 /* logfile */
267 if (!conf.logfile_given && conf.daemon_given) {
268 ret = -1;
269 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
270 goto out;
271 }
272 if (conf.logfile_given)
273 logfile = open_log(conf.logfile_arg);
274 ret = 1;
275 out:
276 free(cf);
277 free(home);
278 if (ret > 0)
279 return;
280 free(user_list_file);
281 user_list_file = NULL;
282 exit(EXIT_FAILURE);
283 }
284
285 static void setup_signal_handling(void)
286 {
287 int ret = 0;
288
289 signal_pipe = para_signal_init();
290
291 PARA_NOTICE_LOG("setting up signal handlers\n");
292 ret += para_install_sighandler(SIGINT);
293 ret += para_install_sighandler(SIGTERM);
294 ret += para_install_sighandler(SIGHUP);
295 ret += para_install_sighandler(SIGCHLD);
296 ret += para_install_sighandler(SIGUSR1);
297 signal(SIGPIPE, SIG_IGN);
298 if (ret != 5) {
299 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
300 exit(EXIT_FAILURE);
301 }
302 add_close_on_fork_list(signal_pipe);
303 }
304
305 static unsigned init_network(void)
306 {
307 int fd, ret = init_tcp_socket(conf.port_arg);
308
309 if (ret < 0)
310 goto err;
311 fd = ret;
312 ret = mark_fd_nonblock(fd);
313 if (ret < 0)
314 goto err;
315 add_close_on_fork_list(fd); /* child doesn't need the listener */
316 return fd;
317 err:
318 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
319 exit(EXIT_FAILURE);
320 }
321
322 static void init_random_seed(void)
323 {
324 int fd, ret = -1;
325 unsigned int seed;
326 size_t len = sizeof(unsigned int);
327
328 fd = open("/dev/urandom", O_RDONLY);
329 if (fd < 0)
330 goto out;
331 ret = -2;
332 if (read(fd, &seed, len) != len)
333 goto out;
334 srandom(seed);
335 ret = 1;
336 out:
337 if (fd >= 0)
338 close(fd);
339 if (ret > 0)
340 return;
341 PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
342 ret);
343 exit(EXIT_FAILURE);
344 }
345
346 uint32_t afs_socket_cookie;
347 int afs_socket;
348 static pid_t afs_pid;
349
350 static void init_afs(void)
351 {
352 int ret, afs_server_socket[2];
353
354 ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
355 if (ret < 0)
356 exit(EXIT_FAILURE);
357 afs_socket_cookie = para_random((uint32_t)-1);
358 afs_pid = fork();
359 if (afs_pid < 0)
360 exit(EXIT_FAILURE);
361 if (!afs_pid) { /* child (afs) */
362 close(afs_server_socket[0]);
363 afs_init(afs_socket_cookie, afs_server_socket[1]);
364 }
365 close(afs_server_socket[1]);
366 afs_socket = afs_server_socket[0];
367 ret = mark_fd_nonblock(afs_socket);
368 if (ret < 0)
369 exit(EXIT_FAILURE);
370 add_close_on_fork_list(afs_socket);
371 PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n", afs_socket,
372 (unsigned) afs_socket_cookie);
373 }
374
375
376 static unsigned server_init(int argc, char **argv)
377 {
378 /* connector's address information */
379 int sockfd;
380
381 init_random_seed();
382 /* parse command line options */
383 server_cmdline_parser(argc, argv, &conf);
384 HANDLE_VERSION_FLAG("server", conf);
385 para_drop_privileges(conf.user_arg, conf.group_arg);
386 /* parse config file, open log and set defaults */
387 parse_config(0);
388 log_welcome("para_server", conf.loglevel_arg);
389 shm_init(); /* init mmd struct */
390 server_uptime(UPTIME_SET); /* reset server uptime */
391 init_user_list(user_list_file);
392 /* become daemon */
393 if (conf.daemon_given)
394 daemon_init();
395 PARA_NOTICE_LOG("initializing audio format handlers\n");
396 afh_init();
397 PARA_NOTICE_LOG("initializing virtual streaming system\n");
398 vss_init();
399 mmd->server_pid = getpid();
400 setup_signal_handling();
401 PARA_NOTICE_LOG("initializing the audio file selector\n");
402 init_afs();
403 mmd_lock();
404 /* init network socket */
405 PARA_NOTICE_LOG("initializing tcp command socket\n");
406 sockfd = init_network();
407 PARA_NOTICE_LOG("server init complete\n");
408 return sockfd;
409 }
410
411 /*
412 * called when server gets SIGHUP or when client invokes hup command.
413 */
414 static void handle_sighup(void)
415 {
416 PARA_NOTICE_LOG("%s", "SIGHUP\n");
417 close_log(logfile); /* gets reopened if necessary by parse_config */
418 logfile = NULL;
419 parse_config(1); /* reopens log */
420 init_user_list(user_list_file); /* reload user list */
421 if (afs_pid)
422 kill(afs_pid, SIGHUP);
423 }
424
425 static void status_refresh(void)
426 {
427 static int prev_uptime = -1, prev_events = -1;
428 int uptime = server_uptime(UPTIME_GET), ret = 1;
429
430 if (prev_events != mmd->events)
431 goto out;
432 if (mmd->new_vss_status_flags != mmd->vss_status_flags)
433 goto out;
434 if (uptime / 60 != prev_uptime / 60)
435 goto out;
436 ret = 0;
437 out:
438 prev_uptime = uptime;
439 prev_events = mmd->events;
440 mmd->vss_status_flags = mmd->new_vss_status_flags;
441 if (ret) {
442 PARA_DEBUG_LOG("%d events, forcing status update\n",
443 mmd->events);
444 killpg(0, SIGUSR1);
445 }
446 }
447
448 /**
449 * the main function of para_server
450 *
451 * \param argc usual argument count
452 * \param argv usual argument vector
453 *
454 * \return EXIT_SUCCESS or EXIT_FAILURE
455 *
456 */
457 int main(int argc, char *argv[])
458 {
459 /* listen on sock_fd, new connection on new_fd */
460 int sockfd, new_fd;
461 struct sockaddr_in their_addr;
462 int i, max_fileno, ret;
463 pid_t chld_pid;
464 fd_set rfds, wfds;
465 struct timeval *timeout;
466
467 valid_fd_012();
468 sockfd = server_init(argc, argv);
469 repeat:
470 FD_ZERO(&rfds);
471 FD_ZERO(&wfds);
472 max_fileno = -1;
473 /* check socket and signal pipe in any case */
474 para_fd_set(sockfd, &rfds, &max_fileno);
475 para_fd_set(signal_pipe, &rfds, &max_fileno);
476 timeout = vss_preselect(&rfds, &wfds, &max_fileno);
477 status_refresh();
478 for (i = 0; senders[i].name; i++) {
479 if (senders[i].status != SENDER_ON)
480 continue;
481 if (!senders[i].pre_select)
482 continue;
483 senders[i].pre_select(&max_fileno, &rfds, &wfds);
484 }
485 mmd_unlock();
486 ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
487 mmd_lock();
488 vss_post_select(&rfds, &wfds);
489 if (ret < 0)
490 goto repeat;
491 for (i = 0; senders[i].name; i++) {
492 if (senders[i].status != SENDER_ON)
493 continue;
494 if (!senders[i].post_select)
495 continue;
496 senders[i].post_select(&rfds, &wfds);
497 }
498 vss_send_chunk();
499 status_refresh();
500 if (FD_ISSET(signal_pipe, &rfds)) {
501 int sig;
502 pid_t pid;
503 sig = para_next_signal();
504 switch (sig) {
505 case SIGHUP:
506 handle_sighup();
507 break;
508 case SIGCHLD:
509 for (;;) {
510 ret = para_reap_child(&pid);
511 if (ret <= 0)
512 break;
513 if (pid != afs_pid)
514 continue;
515 PARA_EMERG_LOG("fatal: afs died\n");
516 goto genocide;
517 }
518 break;
519 /* die on sigint/sigterm. Kill all children too. */
520 case SIGINT:
521 case SIGTERM:
522 PARA_EMERG_LOG("terminating on signal %d\n", sig);
523 genocide:
524 kill(0, SIGTERM);
525 mutex_destroy(mmd_mutex);
526 shm_detach(mmd);
527 shm_destroy(mmd_shm_id);
528
529 exit(EXIT_FAILURE);
530 }
531 }
532 if (mmd->sender_cmd_data.cmd_num >= 0) {
533 int num = mmd->sender_cmd_data.cmd_num,
534 s = mmd->sender_cmd_data.sender_num;
535
536 if (senders[s].client_cmds[num])
537 senders[s].client_cmds[num](&mmd->sender_cmd_data);
538 mmd->sender_cmd_data.cmd_num = -1;
539 }
540 if (!FD_ISSET(sockfd, &rfds))
541 goto repeat;
542
543 new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
544 if (new_fd < 0)
545 goto repeat;
546 PARA_INFO_LOG("got connection from %s, forking\n",
547 inet_ntoa(their_addr.sin_addr));
548 mmd->num_connects++;
549 mmd->active_connections++;
550 random();
551 chld_pid = fork();
552 if (chld_pid < 0) {
553 PARA_CRIT_LOG("%s", "fork failed\n");
554 goto repeat;
555 }
556 if (chld_pid) {
557 close(new_fd);
558 /* parent keeps accepting connections */
559 goto repeat;
560 }
561 alarm(ALARM_TIMEOUT);
562 close_listed_fds();
563 para_signal_shutdown();
564 /*
565 * put info on who we are serving into argv[0] to make
566 * client ip visible in top/ps
567 */
568 for (i = argc - 1; i >= 0; i--)
569 memset(argv[i], 0, strlen(argv[i]));
570 sprintf(argv[0], "para_server (serving %s)",
571 inet_ntoa(their_addr.sin_addr));
572 return handle_connect(new_fd, &their_addr);
573 }