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[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 "user_list.h"
46
47 /** define the array of error lists needed by para_server */
48 INIT_SERVER_ERRLISTS;
49
50 /** shut down non-authorized connections after that many seconds */
51 #define ALARM_TIMEOUT 10
52
53 /* these are exported to afs.c. command.c and to all selectors */
54 struct misc_meta_data *mmd;
55 /** the configuration of para_server
56 *
57 * It also contains the options for all audio file selectors and all supported
58 * senders.
59 */
60 struct server_args_info conf;
61 char *user_list_file = NULL;
62 extern void dccp_send_init(struct sender *);
63 extern void http_send_init(struct sender *);
64 extern void ortp_send_init(struct sender *);
65
66 /* TODO: This is better handled by autoconf */
67 /** the list of supported audio file selectors */
68 struct audio_file_selector selectors[] = {
69 {
70 .name = "random",
71 .init = random_selector_init,
72 .update_audio_file = NULL,
73 },
74 {
75 .name = "playlist",
76 .init = playlist_selector_init,
77 .update_audio_file = NULL,
78 .pre_select = NULL,
79 .post_select = NULL,
80 },
81 #ifdef HAVE_MYSQL
82 {
83 .name = "mysql",
84 .init = mysql_selector_init,
85 .update_audio_file = NULL,
86 .pre_select = NULL,
87 .post_select = NULL,
88 },
89 #endif
90 {
91 .name = NULL,
92 }
93 };
94
95 /** the list of supported senders */
96 struct sender senders[] = {
97 {
98 .name = "http",
99 .init = http_send_init,
100 },
101 {
102 .name = "dccp",
103 .init = dccp_send_init,
104 },
105 #ifdef HAVE_ORTP
106 {
107 .name = "ortp",
108 .init = ortp_send_init,
109 },
110 #endif
111 {
112 .name = NULL,
113 }
114 };
115
116
117 /* global variables for server-internal use */
118 static FILE *logfile;
119 static int mmd_mutex, mmd_shm_id;
120 static int signal_pipe;
121
122 /**
123 * para_server's log function
124 *
125 * \param ll the log level
126 * \param fmt the format string describing the log message
127 */
128 void para_log(int ll, const char* fmt,...)
129 {
130 va_list argp;
131 FILE *outfd;
132 struct tm *tm;
133 time_t t1;
134 char str[MAXLINE] = "";
135 pid_t mypid;
136
137 if (ll < conf.loglevel_arg)
138 return;
139 outfd = logfile? logfile : stderr;
140 time(&t1);
141 tm = localtime(&t1);
142 strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
143 fprintf(outfd, "%s ", str);
144 if (conf.loglevel_arg <= INFO)
145 fprintf(outfd, "%i: ", ll);
146 mypid = getpid();
147 if (conf.loglevel_arg <= INFO)
148 fprintf(outfd, "(%d) ", mypid);
149 va_start(argp, fmt);
150 vfprintf(outfd, fmt, argp);
151 va_end(argp);
152 }
153
154 /*
155 * setup shared memory area and get mutex for locking
156 */
157 static void shm_init(void)
158 {
159 void *shm;
160 int ret = shm_new(sizeof(struct misc_meta_data));
161
162 if (ret < 0)
163 goto err_out;
164
165 ret = shm_attach(ret, ATTACH_RW, &shm);
166 if (ret < 0)
167 goto err_out;
168 mmd = shm;
169 mmd_shm_id = ret;
170
171 ret = mutex_new();
172 if (ret < 0)
173 goto err_out;
174 mmd_mutex = ret;
175
176 mmd->selector_num = 0;
177 mmd->num_played = 0;
178 mmd->num_commands = 0;
179 mmd->events = 0;
180 mmd->num_connects = 0;
181 mmd->active_connections = 0;
182 strcpy(mmd->filename, "(none)");
183 mmd->audio_format = -1;
184 mmd->afs_status_flags = AFS_NEXT;
185 mmd->new_afs_status_flags = AFS_NEXT;
186 mmd->sender_cmd_data.cmd_num = -1;
187 return;
188 err_out:
189 PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
190 exit(EXIT_FAILURE);
191 }
192
193 /**
194 * lock the shared memory area containing the mmd struct
195 *
196 * \sa semop(2), struct misc_meta_data
197 */
198 void mmd_lock(void)
199 {
200 mutex_lock(mmd_mutex);
201 }
202
203 /**
204 * unlock the shared memory area containing the mmd struct
205 *
206 * \sa semop(2), struct misc_meta_data
207 */
208
209 void mmd_unlock(void)
210 {
211 mutex_unlock(mmd_mutex);
212 }
213
214 static void parse_config(int override)
215 {
216 char *home = para_homedir();
217 struct stat statbuf;
218 int ret;
219 char *cf;
220
221 if (conf.config_file_given)
222 cf = conf.config_file_arg;
223 else
224 cf = make_message("%s/.paraslash/server.conf", home);
225 free(user_list_file);
226 if (!conf.user_list_given)
227 user_list_file = make_message("%s/.paraslash/server.users", home);
228 else
229 user_list_file = para_strdup(conf.user_list_arg);
230 ret = stat(cf, &statbuf);
231 if (ret && conf.config_file_given) {
232 ret = -1;
233 PARA_EMERG_LOG("can not stat config file %s\n", cf);
234 goto out;
235 }
236 if (!ret) {
237 int tmp = conf.daemon_given;
238 server_cmdline_parser_configfile(cf, &conf, override, 0, 0);
239 conf.daemon_given = tmp;
240 }
241 /* logfile */
242 if (!conf.logfile_given && conf.daemon_given) {
243 ret = -1;
244 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
245 goto out;
246 }
247 if (conf.logfile_given)
248 logfile = open_log(conf.logfile_arg);
249 ret = 1;
250 out:
251 free(cf);
252 free(home);
253 if (ret > 0)
254 return;
255 free(user_list_file);
256 user_list_file = NULL;
257 exit(EXIT_FAILURE);
258 }
259
260 static void setup_signal_handling(void)
261 {
262 int ret = 0;
263
264 signal_pipe = para_signal_init();
265 PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
266 ret += para_install_sighandler(SIGINT);
267 ret += para_install_sighandler(SIGTERM);
268 ret += para_install_sighandler(SIGHUP);
269 ret += para_install_sighandler(SIGCHLD);
270 ret += para_install_sighandler(SIGUSR1);
271 signal(SIGPIPE, SIG_IGN);
272 if (ret != 5) {
273 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
274 exit(EXIT_FAILURE);
275 }
276 }
277
278 static void init_selector(void)
279 {
280 int i, ret;
281
282 mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
283 if (!conf.selector_given)
284 goto random;
285 for (i = 0; selectors[i].name; i++) {
286 if (strcmp(selectors[i].name, conf.selector_arg))
287 continue;
288 PARA_NOTICE_LOG("initializing %s audio file selector\n",
289 selectors[i].name);
290 ret = selectors[i].init(&selectors[i]);
291 if (ret < 0) {
292 PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
293 break;
294 }
295 mmd->selector_num = i;
296 return;
297 }
298 PARA_WARNING_LOG("%s", "falling back to the random selector\n");
299 random:
300 mmd->selector_num = 0;
301 selectors[0].init(&selectors[0]); /* always successful */
302 }
303
304 static unsigned init_network(void)
305 {
306 int fd, ret = init_tcp_socket(conf.port_arg);
307
308 if (ret < 0)
309 goto err;
310 fd = ret;
311 ret = mark_fd_nonblock(fd);
312 if (ret < 0)
313 goto err;
314 return fd;
315 err:
316 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
317 exit(EXIT_FAILURE);
318 }
319
320 static void init_random_seed(void)
321 {
322 int fd, ret = -1, len = sizeof(unsigned int);
323 unsigned int seed;
324
325 fd = open("/dev/urandom", O_RDONLY);
326 if (fd < 0)
327 goto out;
328 ret = -2;
329 if (read(fd, &seed, len) != len)
330 goto out;
331 srandom(seed);
332 ret = 1;
333 out:
334 if (fd >= 0)
335 close(fd);
336 if (ret > 0)
337 return;
338 PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
339 ret);
340 exit(EXIT_FAILURE);
341 }
342
343 static unsigned do_inits(int argc, char **argv)
344 {
345 /* connector's address information */
346 int sockfd;
347
348 init_random_seed();
349 /* parse command line options */
350 server_cmdline_parser(argc, argv, &conf);
351 para_drop_privileges(conf.user_arg, conf.group_arg);
352 /* parse config file, open log and set defaults */
353 parse_config(0);
354 log_welcome("para_server", conf.loglevel_arg);
355 shm_init(); /* init mmd struct */
356 server_uptime(UPTIME_SET); /* reset server uptime */
357 init_user_list(user_list_file);
358 /* become daemon */
359 if (conf.daemon_given)
360 daemon_init();
361 init_selector();
362 PARA_NOTICE_LOG("%s", "initializing audio file sender\n");
363 /* audio file sender */
364 afs_init();
365 mmd->server_pid = getpid();
366 setup_signal_handling();
367 mmd_lock();
368 /* init network socket */
369 PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
370 sockfd = init_network();
371 PARA_NOTICE_LOG("%s", "init complete\n");
372 return sockfd;
373 }
374
375 static void change_selector(void)
376 {
377 int ret, old = mmd->selector_num, new = mmd->selector_change;
378
379 selectors[old].shutdown();
380 ret = selectors[new].init(&selectors[new]);
381 mmd->selector_change = -1; /* reset */
382 if (ret >= 0) {
383 mmd->selector_num = new;
384 return;
385 }
386 /* init failed */
387 PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
388 selectors[0].init(&selectors[0]);
389 mmd->selector_num = 0;
390 }
391
392 /*
393 * called when server gets SIGHUP or when client invokes hup command.
394 */
395 static void handle_sighup(void)
396 {
397 PARA_NOTICE_LOG("%s", "SIGHUP\n");
398 close_log(logfile); /* gets reopened if necessary by parse_config */
399 logfile = NULL;
400 parse_config(1); /* reopens log */
401 mmd->selector_change = mmd->selector_num; /* do not change selector.. */
402 change_selector(); /* .. just reload */
403 init_user_list(user_list_file); /* reload user list */
404 }
405
406 static void status_refresh(void)
407 {
408 static int prev_uptime = -1, prev_events = -1;
409 int uptime = server_uptime(UPTIME_GET), ret = 1;
410
411 if (prev_events != mmd->events)
412 goto out;
413 if (mmd->new_afs_status_flags != mmd->afs_status_flags)
414 goto out;
415 if (uptime / 60 != prev_uptime / 60)
416 goto out;
417 ret = 0;
418 out:
419 prev_uptime = uptime;
420 prev_events = mmd->events;
421 mmd->afs_status_flags = mmd->new_afs_status_flags;
422 if (ret) {
423 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
424 mmd->events, mmd->audio_format);
425 killpg(0, SIGUSR1);
426 }
427 }
428
429 /*
430 * MAIN
431 */
432 int main(int argc, char *argv[])
433 {
434 /* listen on sock_fd, new connection on new_fd */
435 int sockfd, new_fd;
436 struct sockaddr_in their_addr;
437 int i, max_fileno, ret;
438 pid_t chld_pid;
439 fd_set rfds, wfds;
440 struct timeval *timeout;
441
442 valid_fd_012();
443 sockfd = do_inits(argc, argv);
444 repeat:
445 FD_ZERO(&rfds);
446 FD_ZERO(&wfds);
447 max_fileno = -1;
448 /* check socket and signal pipe in any case */
449 para_fd_set(sockfd, &rfds, &max_fileno);
450 para_fd_set(signal_pipe, &rfds, &max_fileno);
451 timeout = afs_preselect();
452 status_refresh();
453 for (i = 0; senders[i].name; i++) {
454 if (senders[i].status != SENDER_ON)
455 continue;
456 if (!senders[i].pre_select)
457 continue;
458 senders[i].pre_select( &max_fileno, &rfds, &wfds);
459 }
460 if (selectors[mmd->selector_num].pre_select) {
461 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
462 max_fileno = PARA_MAX(max_fileno, ret);
463 }
464 mmd_unlock();
465 ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
466 mmd_lock();
467 if (mmd->selector_change >= 0)
468 change_selector();
469 if (selectors[mmd->selector_num].post_select)
470 selectors[mmd->selector_num].post_select(&rfds, &wfds);
471 if (ret < 0)
472 goto repeat;
473 for (i = 0; senders[i].name; i++) {
474 if (senders[i].status != SENDER_ON)
475 continue;
476 if (!senders[i].post_select)
477 continue;
478 senders[i].post_select(&rfds, &wfds);
479 }
480 afs_send_chunk();
481 status_refresh();
482 if (FD_ISSET(signal_pipe, &rfds)) {
483 int sig;
484 sig = para_next_signal();
485 switch (sig) {
486 case SIGHUP:
487 handle_sighup();
488 break;
489 case SIGCHLD:
490 para_reap_children();
491 break;
492 /* die on sigint/sigterm. Kill all children too. */
493 case SIGINT:
494 case SIGTERM:
495 PARA_EMERG_LOG("terminating on signal %d\n", sig);
496 kill(0, SIGTERM);
497 selectors[mmd->selector_num].shutdown();
498 mutex_destroy(mmd_mutex);
499 shm_detach(mmd);
500 shm_destroy(mmd_shm_id);
501 exit(EXIT_FAILURE);
502 }
503 }
504 if (mmd->sender_cmd_data.cmd_num >= 0) {
505 int num = mmd->sender_cmd_data.cmd_num,
506 s = mmd->sender_cmd_data.sender_num;
507
508 if (senders[s].client_cmds[num])
509 senders[s].client_cmds[num](&mmd->sender_cmd_data);
510 mmd->sender_cmd_data.cmd_num = -1;
511 }
512 if (!FD_ISSET(sockfd, &rfds))
513 goto repeat;
514
515 new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
516 if (new_fd < 0)
517 goto repeat;
518 PARA_INFO_LOG("got connection from %s, forking\n",
519 inet_ntoa(their_addr.sin_addr));
520 mmd->num_connects++;
521 mmd->active_connections++;
522 random();
523 chld_pid = fork();
524 if (chld_pid < 0) {
525 PARA_CRIT_LOG("%s", "fork failed\n");
526 goto repeat;
527 }
528 if (chld_pid) {
529 close(new_fd);
530 /* parent keeps accepting connections */
531 goto repeat;
532 }
533 alarm(ALARM_TIMEOUT);
534 close_listed_fds();
535 close(sockfd); /* child doesn't need the listener */
536 /*
537 * put info on who we are serving into argv[0] to make
538 * client ip visible in top/ps
539 */
540 for (i = argc - 1; i >= 0; i--)
541 memset(argv[i], 0, strlen(argv[i]));
542 sprintf(argv[0], "para_server (serving %s)",
543 inet_ntoa(their_addr.sin_addr));
544 return handle_connect(new_fd, &their_addr);
545 }