6195266bb8f87ca168c410c44aef5dfac18586b4
[paraslash.git] / server.c
1 /*
2 * Copyright (C) 1997-2006 Andre Noll <maan@systemlinux.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
17 */
18
19 /** \file server.c Paraslash's main server */
20
21
22 /** \mainpage Paraslash API Reference
23 *
24 * Good starting points for reading are probably \ref audio_file_selector,
25 * \ref sender, \ref receiver, \ref receiver_node, \ref filter, \ref
26 * filter_node.
27 *
28 */
29
30
31
32 #include "server.cmdline.h"
33 #include "db.h"
34 #include "server.h"
35 #include "afs.h"
36 #include "config.h"
37 #include "close_on_fork.h"
38 #include "send.h"
39 #include "error.h"
40 #include "net.h"
41 #include "daemon.h"
42 #include "string.h"
43 #include "ipc.h"
44 #include "fd.h"
45 #include "signal.h"
46 #include "user_list.h"
47
48 /** define the array of error lists needed by para_server */
49 INIT_SERVER_ERRLISTS;
50
51 /** shut down non-authorized connections after that many seconds */
52 #define ALARM_TIMEOUT 10
53
54 /* these are exported to afs.c. command.c and to all selectors */
55 struct misc_meta_data *mmd;
56 /** the configuration of para_server
57 *
58 * It also contains the options for all audio file selectors and all supported
59 * senders.
60 */
61 struct server_args_info conf;
62 char *user_list_file = NULL;
63 extern void dccp_send_init(struct sender *);
64 extern void http_send_init(struct sender *);
65 extern void ortp_send_init(struct sender *);
66
67 /* TODO: This is better handled by autoconf */
68 /** the list of supported audio file selectors */
69 struct audio_file_selector selectors[] = {
70 {
71 .name = "random",
72 .init = random_selector_init,
73 .update_audio_file = NULL,
74 },
75 {
76 .name = "playlist",
77 .init = playlist_selector_init,
78 .update_audio_file = NULL,
79 .pre_select = NULL,
80 .post_select = NULL,
81 },
82 #ifdef HAVE_MYSQL
83 {
84 .name = "mysql",
85 .init = mysql_selector_init,
86 .update_audio_file = NULL,
87 .pre_select = NULL,
88 .post_select = NULL,
89 },
90 #endif
91 {
92 .name = NULL,
93 }
94 };
95
96 /** the list of supported senders */
97 struct sender senders[] = {
98 {
99 .name = "http",
100 .init = http_send_init,
101 },
102 {
103 .name = "dccp",
104 .init = dccp_send_init,
105 },
106 #ifdef HAVE_ORTP
107 {
108 .name = "ortp",
109 .init = ortp_send_init,
110 },
111 #endif
112 {
113 .name = NULL,
114 }
115 };
116
117
118 /* global variables for server-internal use */
119 static FILE *logfile;
120 static int mmd_mutex, mmd_shm_id;
121 static int signal_pipe;
122
123 /**
124 * para_server's log function
125 *
126 * \param ll the log level
127 * \param fmt the format string describing the log message
128 */
129 void para_log(int ll, const char* fmt,...)
130 {
131 va_list argp;
132 FILE *outfd;
133 struct tm *tm;
134 time_t t1;
135 char str[MAXLINE] = "";
136 pid_t mypid;
137
138 if (ll < conf.loglevel_arg)
139 return;
140 outfd = logfile? logfile : stderr;
141 time(&t1);
142 tm = localtime(&t1);
143 strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
144 fprintf(outfd, "%s ", str);
145 if (conf.loglevel_arg <= INFO)
146 fprintf(outfd, "%i: ", ll);
147 mypid = getpid();
148 if (conf.loglevel_arg <= INFO)
149 fprintf(outfd, "(%d) ", mypid);
150 va_start(argp, fmt);
151 vfprintf(outfd, fmt, argp);
152 va_end(argp);
153 }
154
155 /*
156 * setup shared memory area and get mutex for locking
157 */
158 static void shm_init(void)
159 {
160 void *shm;
161 int ret = shm_new(sizeof(struct misc_meta_data));
162
163 if (ret < 0)
164 goto err_out;
165
166 ret = shm_attach(ret, ATTACH_RW, &shm);
167 if (ret < 0)
168 goto err_out;
169 mmd = shm;
170 mmd_shm_id = ret;
171
172 ret = mutex_new();
173 if (ret < 0)
174 goto err_out;
175 mmd_mutex = ret;
176
177 mmd->selector_num = 0;
178 mmd->num_played = 0;
179 mmd->num_commands = 0;
180 mmd->events = 0;
181 mmd->num_connects = 0;
182 mmd->active_connections = 0;
183 strcpy(mmd->filename, "(none)");
184 mmd->audio_format = -1;
185 mmd->afs_status_flags = AFS_NEXT;
186 mmd->new_afs_status_flags = AFS_NEXT;
187 mmd->sender_cmd_data.cmd_num = -1;
188 return;
189 err_out:
190 PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
191 exit(EXIT_FAILURE);
192 }
193
194 /**
195 * lock the shared memory area containing the mmd struct
196 *
197 * \sa semop(2), struct misc_meta_data
198 */
199 void mmd_lock(void)
200 {
201 mutex_lock(mmd_mutex);
202 }
203
204 /**
205 * unlock the shared memory area containing the mmd struct
206 *
207 * \sa semop(2), struct misc_meta_data
208 */
209
210 void mmd_unlock(void)
211 {
212 mutex_unlock(mmd_mutex);
213 }
214
215 static void parse_config(int override)
216 {
217 char *home = para_homedir();
218 struct stat statbuf;
219 int ret;
220 char *cf;
221
222 if (conf.config_file_given)
223 cf = conf.config_file_arg;
224 else
225 cf = make_message("%s/.paraslash/server.conf", home);
226 free(user_list_file);
227 if (!conf.user_list_given)
228 user_list_file = make_message("%s/.paraslash/server.users", home);
229 else
230 user_list_file = para_strdup(conf.user_list_arg);
231 ret = stat(cf, &statbuf);
232 if (ret && conf.config_file_given) {
233 ret = -1;
234 PARA_EMERG_LOG("can not stat config file %s\n", cf);
235 goto out;
236 }
237 if (!ret) {
238 int tmp = conf.daemon_given;
239 server_cmdline_parser_configfile(cf, &conf, override, 0, 0);
240 conf.daemon_given = tmp;
241 }
242 /* logfile */
243 if (!conf.logfile_given && conf.daemon_given) {
244 ret = -1;
245 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
246 goto out;
247 }
248 if (conf.logfile_given)
249 logfile = open_log(conf.logfile_arg);
250 ret = 1;
251 out:
252 free(cf);
253 free(home);
254 if (ret > 0)
255 return;
256 free(user_list_file);
257 user_list_file = NULL;
258 exit(EXIT_FAILURE);
259 }
260
261 static void setup_signal_handling(void)
262 {
263 int ret = 0;
264
265 signal_pipe = para_signal_init();
266 PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
267 ret += para_install_sighandler(SIGINT);
268 ret += para_install_sighandler(SIGTERM);
269 ret += para_install_sighandler(SIGHUP);
270 ret += para_install_sighandler(SIGCHLD);
271 ret += para_install_sighandler(SIGUSR1);
272 signal(SIGPIPE, SIG_IGN);
273 if (ret != 5) {
274 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
275 exit(EXIT_FAILURE);
276 }
277 }
278
279 static void init_selector(void)
280 {
281 int i, ret;
282
283 mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
284 if (!conf.selector_given)
285 goto random;
286 for (i = 0; selectors[i].name; i++) {
287 if (strcmp(selectors[i].name, conf.selector_arg))
288 continue;
289 PARA_NOTICE_LOG("initializing %s audio file selector\n",
290 selectors[i].name);
291 ret = selectors[i].init(&selectors[i]);
292 if (ret < 0) {
293 PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
294 break;
295 }
296 mmd->selector_num = i;
297 return;
298 }
299 PARA_WARNING_LOG("%s", "falling back to the random selector\n");
300 random:
301 mmd->selector_num = 0;
302 selectors[0].init(&selectors[0]); /* always successful */
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 return fd;
316 err:
317 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
318 exit(EXIT_FAILURE);
319 }
320
321 static void init_random_seed(void)
322 {
323 int fd, ret = -1, len = sizeof(unsigned int);
324 unsigned int seed;
325
326 fd = open("/dev/urandom", O_RDONLY);
327 if (fd < 0)
328 goto out;
329 ret = -2;
330 if (read(fd, &seed, len) != len)
331 goto out;
332 srandom(seed);
333 ret = 1;
334 out:
335 if (fd >= 0)
336 close(fd);
337 if (ret > 0)
338 return;
339 PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
340 ret);
341 exit(EXIT_FAILURE);
342 }
343
344 static unsigned do_inits(int argc, char **argv)
345 {
346 /* connector's address information */
347 int sockfd;
348
349 init_random_seed();
350 /* parse command line options */
351 server_cmdline_parser(argc, argv, &conf);
352 para_drop_privileges(conf.user_arg, conf.group_arg);
353 /* parse config file, open log and set defaults */
354 parse_config(0);
355 log_welcome("para_server", conf.loglevel_arg);
356 shm_init(); /* init mmd struct */
357 server_uptime(UPTIME_SET); /* reset server uptime */
358 init_user_list(user_list_file);
359 /* become daemon */
360 if (conf.daemon_given)
361 daemon_init();
362 init_selector();
363 PARA_NOTICE_LOG("%s", "initializing audio file sender\n");
364 /* audio file sender */
365 afs_init();
366 mmd->server_pid = getpid();
367 setup_signal_handling();
368 mmd_lock();
369 /* init network socket */
370 PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
371 sockfd = init_network();
372 PARA_NOTICE_LOG("%s", "init complete\n");
373 return sockfd;
374 }
375
376 static void change_selector(void)
377 {
378 int ret, old = mmd->selector_num, new = mmd->selector_change;
379
380 selectors[old].shutdown();
381 ret = selectors[new].init(&selectors[new]);
382 mmd->selector_change = -1; /* reset */
383 if (ret >= 0) {
384 mmd->selector_num = new;
385 return;
386 }
387 /* init failed */
388 PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
389 selectors[0].init(&selectors[0]);
390 mmd->selector_num = 0;
391 }
392
393 /*
394 * called when server gets SIGHUP or when client invokes hup command.
395 */
396 static void handle_sighup(void)
397 {
398 PARA_NOTICE_LOG("%s", "SIGHUP\n");
399 close_log(logfile); /* gets reopened if necessary by parse_config */
400 logfile = NULL;
401 parse_config(1); /* reopens log */
402 mmd->selector_change = mmd->selector_num; /* do not change selector.. */
403 change_selector(); /* .. just reload */
404 init_user_list(user_list_file); /* reload user list */
405 }
406
407 static void status_refresh(void)
408 {
409 static int prev_uptime = -1, prev_events = -1;
410 int uptime = server_uptime(UPTIME_GET), ret = 1;
411
412 if (prev_events != mmd->events)
413 goto out;
414 if (mmd->new_afs_status_flags != mmd->afs_status_flags)
415 goto out;
416 if (uptime / 60 != prev_uptime / 60)
417 goto out;
418 ret = 0;
419 out:
420 prev_uptime = uptime;
421 prev_events = mmd->events;
422 mmd->afs_status_flags = mmd->new_afs_status_flags;
423 if (ret) {
424 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
425 mmd->events, mmd->audio_format);
426 killpg(0, SIGUSR1);
427 }
428 }
429
430 /*
431 * MAIN
432 */
433 int main(int argc, char *argv[])
434 {
435 /* listen on sock_fd, new connection on new_fd */
436 int sockfd, new_fd;
437 struct sockaddr_in their_addr;
438 int i, max_fileno, ret;
439 pid_t chld_pid;
440 fd_set rfds, wfds;
441 struct timeval *timeout;
442
443 valid_fd_012();
444 sockfd = do_inits(argc, argv);
445 repeat:
446 FD_ZERO(&rfds);
447 FD_ZERO(&wfds);
448 max_fileno = -1;
449 /* check socket and signal pipe in any case */
450 para_fd_set(sockfd, &rfds, &max_fileno);
451 para_fd_set(signal_pipe, &rfds, &max_fileno);
452 timeout = afs_preselect();
453 status_refresh();
454 for (i = 0; senders[i].name; i++) {
455 if (senders[i].status != SENDER_ON)
456 continue;
457 if (!senders[i].pre_select)
458 continue;
459 senders[i].pre_select( &max_fileno, &rfds, &wfds);
460 }
461 if (selectors[mmd->selector_num].pre_select) {
462 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
463 max_fileno = PARA_MAX(max_fileno, ret);
464 }
465 mmd_unlock();
466 ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
467 mmd_lock();
468 if (mmd->selector_change >= 0)
469 change_selector();
470 if (selectors[mmd->selector_num].post_select)
471 selectors[mmd->selector_num].post_select(&rfds, &wfds);
472 if (ret < 0)
473 goto repeat;
474 for (i = 0; senders[i].name; i++) {
475 if (senders[i].status != SENDER_ON)
476 continue;
477 if (!senders[i].post_select)
478 continue;
479 senders[i].post_select(&rfds, &wfds);
480 }
481 afs_send_chunk();
482 status_refresh();
483 if (FD_ISSET(signal_pipe, &rfds)) {
484 int sig;
485 sig = para_next_signal();
486 switch (sig) {
487 case SIGHUP:
488 handle_sighup();
489 break;
490 case SIGCHLD:
491 para_reap_children();
492 break;
493 /* die on sigint/sigterm. Kill all children too. */
494 case SIGINT:
495 case SIGTERM:
496 PARA_EMERG_LOG("terminating on signal %d\n", sig);
497 kill(0, SIGTERM);
498 selectors[mmd->selector_num].shutdown();
499 mutex_destroy(mmd_mutex);
500 shm_detach(mmd);
501 shm_destroy(mmd_shm_id);
502 exit(EXIT_FAILURE);
503 }
504 }
505 if (mmd->sender_cmd_data.cmd_num >= 0) {
506 int num = mmd->sender_cmd_data.cmd_num,
507 s = mmd->sender_cmd_data.sender_num;
508
509 if (senders[s].client_cmds[num])
510 senders[s].client_cmds[num](&mmd->sender_cmd_data);
511 mmd->sender_cmd_data.cmd_num = -1;
512 }
513 if (!FD_ISSET(sockfd, &rfds))
514 goto repeat;
515
516 new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
517 if (new_fd < 0)
518 goto repeat;
519 PARA_INFO_LOG("got connection from %s, forking\n",
520 inet_ntoa(their_addr.sin_addr));
521 mmd->num_connects++;
522 mmd->active_connections++;
523 random();
524 chld_pid = fork();
525 if (chld_pid < 0) {
526 PARA_CRIT_LOG("%s", "fork failed\n");
527 goto repeat;
528 }
529 if (chld_pid) {
530 close(new_fd);
531 /* parent keeps accepting connections */
532 goto repeat;
533 }
534 alarm(ALARM_TIMEOUT);
535 close_listed_fds();
536 close(sockfd); /* child doesn't need the listener */
537 /*
538 * put info on who we are serving into argv[0] to make
539 * client ip visible in top/ps
540 */
541 for (i = argc - 1; i >= 0; i--)
542 memset(argv[i], 0, strlen(argv[i]));
543 sprintf(argv[0], "para_server (serving %s)",
544 inet_ntoa(their_addr.sin_addr));
545 return handle_connect(new_fd, &their_addr);
546 }