Make struct signal_task generic and make afs use it.
[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 /** \mainpage Paraslash API Reference
11 *
12 * Good starting points for reading are probably \ref audio_file_selector,
13 * \ref sender, \ref receiver, \ref receiver_node, \ref filter, \ref
14 * filter_node.
15 *
16 */
17
18
19 #include "para.h"
20 #include "server.cmdline.h"
21 #include "afs_common.h"
22 #include "afh.h"
23 #include "server.h"
24 #include "vss.h"
25 #include "config.h"
26 #include "close_on_fork.h"
27 #include "send.h"
28 #include "error.h"
29 #include "net.h"
30 #include "daemon.h"
31 #include "string.h"
32 #include "ipc.h"
33 #include "fd.h"
34 #include "list.h"
35 #include "sched.h"
36 #include "signal.h"
37 #include "user_list.h"
38 #include "afs.h"
39
40 /** define the array of error lists needed by para_server */
41 INIT_SERVER_ERRLISTS;
42
43 /** shut down non-authorized connections after that many seconds */
44 #define ALARM_TIMEOUT 10
45
46 /**
47 * pointer to shared memory area for communication between para_server
48 * and its children. exported to vss.c. command.c and to all selectors.
49 */
50 struct misc_meta_data *mmd;
51
52 /**
53 * the configuration of para_server
54 *
55 * It also contains the options for all audio file selectors, audio format handler
56 * and all supported senders.
57 */
58 struct server_args_info conf;
59
60 /** the file containing user information (public key, permissions) */
61 char *user_list_file = NULL;
62
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->vss_status_flags = VSS_NEXT;
186 mmd->new_vss_status_flags = VSS_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 struct server_cmdline_parser_params params = {
240 .override = override,
241 .initialize = 0,
242 .check_required = 0,
243 .check_ambiguity = 0
244 };
245 server_cmdline_parser_config_file(cf, &conf, &params);
246 conf.daemon_given = tmp;
247 }
248 /* logfile */
249 if (!conf.logfile_given && conf.daemon_given) {
250 ret = -1;
251 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
252 goto out;
253 }
254 if (conf.logfile_given)
255 logfile = open_log(conf.logfile_arg);
256 ret = 1;
257 out:
258 free(cf);
259 free(home);
260 if (ret > 0)
261 return;
262 free(user_list_file);
263 user_list_file = NULL;
264 exit(EXIT_FAILURE);
265 }
266
267 static void setup_signal_handling(void)
268 {
269 int ret = 0;
270
271 signal_pipe = para_signal_init();
272 PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
273 ret += para_install_sighandler(SIGINT);
274 ret += para_install_sighandler(SIGTERM);
275 ret += para_install_sighandler(SIGHUP);
276 ret += para_install_sighandler(SIGCHLD);
277 ret += para_install_sighandler(SIGUSR1);
278 signal(SIGPIPE, SIG_IGN);
279 if (ret != 5) {
280 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
281 exit(EXIT_FAILURE);
282 }
283 }
284
285 static void init_selector(void)
286 {
287 int i, ret;
288
289 mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
290 if (!conf.selector_given)
291 goto random;
292 for (i = 0; selectors[i].name; i++) {
293 if (strcmp(selectors[i].name, conf.selector_arg))
294 continue;
295 PARA_NOTICE_LOG("initializing %s audio file selector\n",
296 selectors[i].name);
297 ret = selectors[i].init(&selectors[i]);
298 if (ret < 0) {
299 PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
300 break;
301 }
302 mmd->selector_num = i;
303 return;
304 }
305 PARA_WARNING_LOG("%s", "falling back to the random selector\n");
306 random:
307 mmd->selector_num = 0;
308 selectors[0].init(&selectors[0]); /* always successful */
309 }
310
311 static unsigned init_network(void)
312 {
313 int fd, ret = init_tcp_socket(conf.port_arg);
314
315 if (ret < 0)
316 goto err;
317 fd = ret;
318 ret = mark_fd_nonblock(fd);
319 if (ret < 0)
320 goto err;
321 return fd;
322 err:
323 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
324 exit(EXIT_FAILURE);
325 }
326
327 static void init_random_seed(void)
328 {
329 int fd, ret = -1;
330 unsigned int seed;
331 size_t len = sizeof(unsigned int);
332
333 fd = open("/dev/urandom", O_RDONLY);
334 if (fd < 0)
335 goto out;
336 ret = -2;
337 if (read(fd, &seed, len) != len)
338 goto out;
339 srandom(seed);
340 ret = 1;
341 out:
342 if (fd >= 0)
343 close(fd);
344 if (ret > 0)
345 return;
346 PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
347 ret);
348 exit(EXIT_FAILURE);
349 }
350
351 static uint32_t afs_socket_cookie;
352 static int afs_socket;
353 pid_t afs_pid;
354
355 static void init_afs(void)
356 {
357 int ret, afs_server_socket[2];
358
359 ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
360 if (ret < 0)
361 exit(EXIT_FAILURE);
362 afs_socket_cookie = para_random((uint32_t)-1);
363 afs_pid = fork();
364 if (afs_pid < 0)
365 exit(EXIT_FAILURE);
366 if (!afs_pid) /* child (afs) */
367 afs_init(afs_socket_cookie, afs_server_socket[1]);
368 close(afs_server_socket[1]);
369 afs_socket = afs_server_socket[0];
370 PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n", afs_socket,
371 (unsigned) afs_socket_cookie);
372 }
373
374
375 static unsigned do_inits(int argc, char **argv)
376 {
377 /* connector's address information */
378 int sockfd;
379
380 init_random_seed();
381 /* parse command line options */
382 server_cmdline_parser(argc, argv, &conf);
383 HANDLE_VERSION_FLAG("server", conf);
384 para_drop_privileges(conf.user_arg, conf.group_arg);
385 /* parse config file, open log and set defaults */
386 parse_config(0);
387 log_welcome("para_server", conf.loglevel_arg);
388 shm_init(); /* init mmd struct */
389 server_uptime(UPTIME_SET); /* reset server uptime */
390 init_user_list(user_list_file);
391 /* become daemon */
392 if (conf.daemon_given)
393 daemon_init();
394 init_selector();
395 // PARA_ERROR_LOG("num: %d\n", mmd->selector_num);
396 PARA_NOTICE_LOG("%s", "initializing virtual streaming system\n");
397 vss_init();
398 mmd->server_pid = getpid();
399 setup_signal_handling();
400 init_afs();
401 mmd_lock();
402 /* init network socket */
403 PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
404 sockfd = init_network();
405 PARA_NOTICE_LOG("%s", "init complete\n");
406 return sockfd;
407 }
408
409 static void change_selector(void)
410 {
411 int ret, old = mmd->selector_num, new = mmd->selector_change;
412
413 selectors[old].shutdown();
414 ret = selectors[new].init(&selectors[new]);
415 mmd->selector_change = -1; /* reset */
416 if (ret >= 0) {
417 mmd->selector_num = new;
418 return;
419 }
420 /* init failed */
421 PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
422 selectors[0].init(&selectors[0]);
423 mmd->selector_num = 0;
424 }
425
426 /*
427 * called when server gets SIGHUP or when client invokes hup command.
428 */
429 static void handle_sighup(void)
430 {
431 PARA_NOTICE_LOG("%s", "SIGHUP\n");
432 close_log(logfile); /* gets reopened if necessary by parse_config */
433 logfile = NULL;
434 parse_config(1); /* reopens log */
435 mmd->selector_change = mmd->selector_num; /* do not change selector.. */
436 change_selector(); /* .. just reload */
437 init_user_list(user_list_file); /* reload user list */
438 }
439
440 static void status_refresh(void)
441 {
442 static int prev_uptime = -1, prev_events = -1;
443 int uptime = server_uptime(UPTIME_GET), ret = 1;
444
445 if (prev_events != mmd->events)
446 goto out;
447 if (mmd->new_vss_status_flags != mmd->vss_status_flags)
448 goto out;
449 if (uptime / 60 != prev_uptime / 60)
450 goto out;
451 ret = 0;
452 out:
453 prev_uptime = uptime;
454 prev_events = mmd->events;
455 mmd->vss_status_flags = mmd->new_vss_status_flags;
456 if (ret) {
457 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
458 mmd->events, mmd->audio_format);
459 killpg(0, SIGUSR1);
460 }
461 }
462
463 /**
464 * the main function of para_server
465 *
466 * \param argc usual argument count
467 * \param argv usual argument vector
468 *
469 * \return EXIT_SUCCESS or EXIT_FAILURE
470 *
471 */
472 int main(int argc, char *argv[])
473 {
474 /* listen on sock_fd, new connection on new_fd */
475 int sockfd, new_fd;
476 struct sockaddr_in their_addr;
477 int i, max_fileno, ret;
478 pid_t chld_pid;
479 fd_set rfds, wfds;
480 struct timeval *timeout;
481
482 valid_fd_012();
483 sockfd = do_inits(argc, argv);
484 repeat:
485 FD_ZERO(&rfds);
486 FD_ZERO(&wfds);
487 max_fileno = -1;
488 /* check socket and signal pipe in any case */
489 para_fd_set(sockfd, &rfds, &max_fileno);
490 para_fd_set(signal_pipe, &rfds, &max_fileno);
491 timeout = vss_preselect();
492 status_refresh();
493 for (i = 0; senders[i].name; i++) {
494 if (senders[i].status != SENDER_ON)
495 continue;
496 if (!senders[i].pre_select)
497 continue;
498 senders[i].pre_select( &max_fileno, &rfds, &wfds);
499 }
500 if (selectors[mmd->selector_num].pre_select) {
501 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
502 max_fileno = PARA_MAX(max_fileno, ret);
503 }
504 mmd_unlock();
505 ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
506 mmd_lock();
507 if (mmd->selector_change >= 0)
508 change_selector();
509 if (selectors[mmd->selector_num].post_select)
510 selectors[mmd->selector_num].post_select(&rfds, &wfds);
511 if (ret < 0)
512 goto repeat;
513 for (i = 0; senders[i].name; i++) {
514 if (senders[i].status != SENDER_ON)
515 continue;
516 if (!senders[i].post_select)
517 continue;
518 senders[i].post_select(&rfds, &wfds);
519 }
520 vss_send_chunk();
521 status_refresh();
522 if (FD_ISSET(signal_pipe, &rfds)) {
523 int sig;
524 pid_t pid;
525 sig = para_next_signal();
526 switch (sig) {
527 case SIGHUP:
528 handle_sighup();
529 break;
530 case SIGCHLD:
531 for (;;) {
532 pid = para_reap_child();
533 if (pid <= 0)
534 break;
535 if (pid != afs_pid)
536 continue;
537 PARA_EMERG_LOG("fatal: afs died\n");
538 goto genocide;
539 }
540 break;
541 /* die on sigint/sigterm. Kill all children too. */
542 case SIGINT:
543 case SIGTERM:
544 PARA_EMERG_LOG("terminating on signal %d\n", sig);
545 genocide:
546 kill(0, SIGTERM);
547 selectors[mmd->selector_num].shutdown();
548 mutex_destroy(mmd_mutex);
549 shm_detach(mmd);
550 shm_destroy(mmd_shm_id);
551
552 exit(EXIT_FAILURE);
553 }
554 }
555 if (mmd->sender_cmd_data.cmd_num >= 0) {
556 int num = mmd->sender_cmd_data.cmd_num,
557 s = mmd->sender_cmd_data.sender_num;
558
559 if (senders[s].client_cmds[num])
560 senders[s].client_cmds[num](&mmd->sender_cmd_data);
561 mmd->sender_cmd_data.cmd_num = -1;
562 }
563 if (!FD_ISSET(sockfd, &rfds))
564 goto repeat;
565
566 new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
567 if (new_fd < 0)
568 goto repeat;
569 PARA_INFO_LOG("got connection from %s, forking\n",
570 inet_ntoa(their_addr.sin_addr));
571 mmd->num_connects++;
572 mmd->active_connections++;
573 random();
574 chld_pid = fork();
575 if (chld_pid < 0) {
576 PARA_CRIT_LOG("%s", "fork failed\n");
577 goto repeat;
578 }
579 if (chld_pid) {
580 close(new_fd);
581 /* parent keeps accepting connections */
582 goto repeat;
583 }
584 alarm(ALARM_TIMEOUT);
585 close_listed_fds();
586 close(sockfd); /* child doesn't need the listener */
587 /*
588 * put info on who we are serving into argv[0] to make
589 * client ip visible in top/ps
590 */
591 for (i = argc - 1; i >= 0; i--)
592 memset(argv[i], 0, strlen(argv[i]));
593 sprintf(argv[0], "para_server (serving %s)",
594 inet_ntoa(their_addr.sin_addr));
595 return handle_connect(new_fd, &their_addr);
596 }