d98e9603ced15a27ea1780ffb7ef850e5138c55e
[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 #include <sys/types.h>
19 #include <dirent.h>
20
21 #include "para.h"
22 #include "server.cmdline.h"
23 #include "afs_common.h"
24 #include "afh.h"
25 #include "server.h"
26 #include "vss.h"
27 #include "config.h"
28 #include "close_on_fork.h"
29 #include "send.h"
30 #include "error.h"
31 #include "net.h"
32 #include "daemon.h"
33 #include "string.h"
34 #include "ipc.h"
35 #include "fd.h"
36 #include "list.h"
37 #include "sched.h"
38 #include "signal.h"
39 #include "user_list.h"
40 #include "afs.h"
41
42 /** define the array of error lists needed by para_server */
43 INIT_SERVER_ERRLISTS;
44
45 /** shut down non-authorized connections after that many seconds */
46 #define ALARM_TIMEOUT 10
47
48 /**
49 * pointer to shared memory area for communication between para_server
50 * and its children. exported to vss.c. command.c and to all selectors.
51 */
52 struct misc_meta_data *mmd;
53
54 /**
55 * the configuration of para_server
56 *
57 * It also contains the options for all audio file selectors, audio format handler
58 * and all supported senders.
59 */
60 struct server_args_info conf;
61
62 /** the file containing user information (public key, permissions) */
63 char *user_list_file = NULL;
64
65 extern void dccp_send_init(struct sender *);
66 extern void http_send_init(struct sender *);
67 extern void ortp_send_init(struct sender *);
68
69 /* TODO: This is better handled by autoconf */
70 /** the list of supported audio file selectors */
71 struct audio_file_selector selectors[] = {
72 {
73 .name = "random",
74 .init = random_selector_init,
75 .update_audio_file = NULL,
76 },
77 {
78 .name = "playlist",
79 .init = playlist_selector_init,
80 .update_audio_file = NULL,
81 .pre_select = NULL,
82 .post_select = NULL,
83 },
84 #ifdef HAVE_MYSQL
85 {
86 .name = "mysql",
87 .init = mysql_selector_init,
88 .update_audio_file = NULL,
89 .pre_select = NULL,
90 .post_select = NULL,
91 },
92 #endif
93 {
94 .name = NULL,
95 }
96 };
97
98 /** the list of supported senders */
99 struct sender senders[] = {
100 {
101 .name = "http",
102 .init = http_send_init,
103 },
104 {
105 .name = "dccp",
106 .init = dccp_send_init,
107 },
108 #ifdef HAVE_ORTP
109 {
110 .name = "ortp",
111 .init = ortp_send_init,
112 },
113 #endif
114 {
115 .name = NULL,
116 }
117 };
118
119
120 /* global variables for server-internal use */
121 static FILE *logfile;
122 static int mmd_mutex, mmd_shm_id;
123 static int signal_pipe;
124
125 /**
126 * para_server's log function
127 *
128 * \param ll the log level
129 * \param fmt the format string describing the log message
130 */
131 void para_log(int ll, const char* fmt,...)
132 {
133 va_list argp;
134 FILE *outfd;
135 struct tm *tm;
136 time_t t1;
137 char str[MAXLINE] = "";
138 pid_t mypid;
139
140 if (ll < conf.loglevel_arg)
141 return;
142 outfd = logfile? logfile : stderr;
143 time(&t1);
144 tm = localtime(&t1);
145 strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
146 fprintf(outfd, "%s ", str);
147 if (conf.loglevel_arg <= INFO)
148 fprintf(outfd, "%i: ", ll);
149 mypid = getpid();
150 if (conf.loglevel_arg <= INFO)
151 fprintf(outfd, "(%d) ", mypid);
152 va_start(argp, fmt);
153 vfprintf(outfd, fmt, argp);
154 va_end(argp);
155 }
156
157 /*
158 * setup shared memory area and get mutex for locking
159 */
160 static void shm_init(void)
161 {
162 void *shm;
163 int ret = shm_new(sizeof(struct misc_meta_data));
164
165 if (ret < 0)
166 goto err_out;
167
168 ret = shm_attach(ret, ATTACH_RW, &shm);
169 if (ret < 0)
170 goto err_out;
171 mmd = shm;
172 mmd_shm_id = ret;
173
174 ret = mutex_new();
175 if (ret < 0)
176 goto err_out;
177 mmd_mutex = ret;
178
179 mmd->selector_num = 0;
180 mmd->num_played = 0;
181 mmd->num_commands = 0;
182 mmd->events = 0;
183 mmd->num_connects = 0;
184 mmd->active_connections = 0;
185 strcpy(mmd->filename, "(none)");
186 mmd->audio_format = -1;
187 mmd->vss_status_flags = VSS_NEXT;
188 mmd->new_vss_status_flags = VSS_NEXT;
189 mmd->sender_cmd_data.cmd_num = -1;
190 return;
191 err_out:
192 PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
193 exit(EXIT_FAILURE);
194 }
195
196 /**
197 * lock the shared memory area containing the mmd struct
198 *
199 * \sa semop(2), struct misc_meta_data
200 */
201 void mmd_lock(void)
202 {
203 mutex_lock(mmd_mutex);
204 }
205
206 /**
207 * unlock the shared memory area containing the mmd struct
208 *
209 * \sa semop(2), struct misc_meta_data
210 */
211
212 void mmd_unlock(void)
213 {
214 mutex_unlock(mmd_mutex);
215 }
216
217 static void parse_config(int override)
218 {
219 char *home = para_homedir();
220 struct stat statbuf;
221 int ret;
222 char *cf;
223
224 if (conf.config_file_given)
225 cf = conf.config_file_arg;
226 else
227 cf = make_message("%s/.paraslash/server.conf", home);
228 free(user_list_file);
229 if (!conf.user_list_given)
230 user_list_file = make_message("%s/.paraslash/server.users", home);
231 else
232 user_list_file = para_strdup(conf.user_list_arg);
233 ret = stat(cf, &statbuf);
234 if (ret && conf.config_file_given) {
235 ret = -1;
236 PARA_EMERG_LOG("can not stat config file %s\n", cf);
237 goto out;
238 }
239 if (!ret) {
240 int tmp = conf.daemon_given;
241 struct server_cmdline_parser_params params = {
242 .override = override,
243 .initialize = 0,
244 .check_required = 0,
245 .check_ambiguity = 0
246 };
247 server_cmdline_parser_config_file(cf, &conf, &params);
248 conf.daemon_given = tmp;
249 }
250 /* logfile */
251 if (!conf.logfile_given && conf.daemon_given) {
252 ret = -1;
253 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
254 goto out;
255 }
256 if (conf.logfile_given)
257 logfile = open_log(conf.logfile_arg);
258 ret = 1;
259 out:
260 free(cf);
261 free(home);
262 if (ret > 0)
263 return;
264 free(user_list_file);
265 user_list_file = NULL;
266 exit(EXIT_FAILURE);
267 }
268
269 static void setup_signal_handling(void)
270 {
271 int ret = 0;
272
273 signal_pipe = para_signal_init();
274 PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
275 ret += para_install_sighandler(SIGINT);
276 ret += para_install_sighandler(SIGTERM);
277 ret += para_install_sighandler(SIGHUP);
278 ret += para_install_sighandler(SIGCHLD);
279 ret += para_install_sighandler(SIGUSR1);
280 signal(SIGPIPE, SIG_IGN);
281 if (ret != 5) {
282 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
283 exit(EXIT_FAILURE);
284 }
285 }
286
287 static void init_selector(void)
288 {
289 int i, ret;
290
291 mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
292 if (!conf.selector_given)
293 goto random;
294 for (i = 0; selectors[i].name; i++) {
295 if (strcmp(selectors[i].name, conf.selector_arg))
296 continue;
297 PARA_NOTICE_LOG("initializing %s audio file selector\n",
298 selectors[i].name);
299 ret = selectors[i].init(&selectors[i]);
300 if (ret < 0) {
301 PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
302 break;
303 }
304 mmd->selector_num = i;
305 return;
306 }
307 PARA_WARNING_LOG("%s", "falling back to the random selector\n");
308 random:
309 mmd->selector_num = 0;
310 selectors[0].init(&selectors[0]); /* always successful */
311 }
312
313 static unsigned init_network(void)
314 {
315 int fd, ret = init_tcp_socket(conf.port_arg);
316
317 if (ret < 0)
318 goto err;
319 fd = ret;
320 ret = mark_fd_nonblock(fd);
321 if (ret < 0)
322 goto err;
323 return fd;
324 err:
325 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
326 exit(EXIT_FAILURE);
327 }
328
329 static void init_random_seed(void)
330 {
331 int fd, ret = -1;
332 unsigned int seed;
333 size_t len = sizeof(unsigned int);
334
335 fd = open("/dev/urandom", O_RDONLY);
336 if (fd < 0)
337 goto out;
338 ret = -2;
339 if (read(fd, &seed, len) != len)
340 goto out;
341 srandom(seed);
342 ret = 1;
343 out:
344 if (fd >= 0)
345 close(fd);
346 if (ret > 0)
347 return;
348 PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
349 ret);
350 exit(EXIT_FAILURE);
351 }
352
353 uint32_t afs_socket_cookie;
354 static int afs_socket;
355 pid_t afs_pid;
356
357 static void init_afs(void)
358 {
359 int ret, afs_server_socket[2];
360
361 ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
362 if (ret < 0)
363 exit(EXIT_FAILURE);
364 afs_socket_cookie = para_random((uint32_t)-1);
365 afs_pid = fork();
366 if (afs_pid < 0)
367 exit(EXIT_FAILURE);
368 if (!afs_pid) { /* child (afs) */
369 close(afs_server_socket[0]);
370 afs_init(afs_socket_cookie, afs_server_socket[1]);
371 }
372 close(afs_server_socket[1]);
373 afs_socket = afs_server_socket[0];
374 ret = mark_fd_nonblock(afs_socket);
375 if (ret < 0)
376 exit(EXIT_FAILURE);
377 add_close_on_fork_list(afs_socket);
378 PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n", afs_socket,
379 (unsigned) afs_socket_cookie);
380 }
381
382
383 static unsigned do_inits(int argc, char **argv)
384 {
385 /* connector's address information */
386 int sockfd;
387
388 init_random_seed();
389 /* parse command line options */
390 server_cmdline_parser(argc, argv, &conf);
391 HANDLE_VERSION_FLAG("server", conf);
392 para_drop_privileges(conf.user_arg, conf.group_arg);
393 /* parse config file, open log and set defaults */
394 parse_config(0);
395 log_welcome("para_server", conf.loglevel_arg);
396 shm_init(); /* init mmd struct */
397 server_uptime(UPTIME_SET); /* reset server uptime */
398 init_user_list(user_list_file);
399 /* become daemon */
400 if (conf.daemon_given)
401 daemon_init();
402 init_selector();
403 // PARA_ERROR_LOG("num: %d\n", mmd->selector_num);
404 PARA_NOTICE_LOG("%s", "initializing virtual streaming system\n");
405 vss_init();
406 mmd->server_pid = getpid();
407 setup_signal_handling();
408 init_afs();
409 mmd_lock();
410 /* init network socket */
411 PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
412 sockfd = init_network();
413 PARA_NOTICE_LOG("%s", "init complete\n");
414 return sockfd;
415 }
416
417 static void change_selector(void)
418 {
419 int ret, old = mmd->selector_num, new = mmd->selector_change;
420
421 selectors[old].shutdown();
422 ret = selectors[new].init(&selectors[new]);
423 mmd->selector_change = -1; /* reset */
424 if (ret >= 0) {
425 mmd->selector_num = new;
426 return;
427 }
428 /* init failed */
429 PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
430 selectors[0].init(&selectors[0]);
431 mmd->selector_num = 0;
432 }
433
434 /*
435 * called when server gets SIGHUP or when client invokes hup command.
436 */
437 static void handle_sighup(void)
438 {
439 PARA_NOTICE_LOG("%s", "SIGHUP\n");
440 close_log(logfile); /* gets reopened if necessary by parse_config */
441 logfile = NULL;
442 parse_config(1); /* reopens log */
443 mmd->selector_change = mmd->selector_num; /* do not change selector.. */
444 change_selector(); /* .. just reload */
445 init_user_list(user_list_file); /* reload user list */
446 }
447
448 static void status_refresh(void)
449 {
450 static int prev_uptime = -1, prev_events = -1;
451 int uptime = server_uptime(UPTIME_GET), ret = 1;
452
453 if (prev_events != mmd->events)
454 goto out;
455 if (mmd->new_vss_status_flags != mmd->vss_status_flags)
456 goto out;
457 if (uptime / 60 != prev_uptime / 60)
458 goto out;
459 ret = 0;
460 out:
461 prev_uptime = uptime;
462 prev_events = mmd->events;
463 mmd->vss_status_flags = mmd->new_vss_status_flags;
464 if (ret) {
465 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
466 mmd->events, mmd->audio_format);
467 killpg(0, SIGUSR1);
468 }
469 }
470
471 /**
472 * the main function of para_server
473 *
474 * \param argc usual argument count
475 * \param argv usual argument vector
476 *
477 * \return EXIT_SUCCESS or EXIT_FAILURE
478 *
479 */
480 int main(int argc, char *argv[])
481 {
482 /* listen on sock_fd, new connection on new_fd */
483 int sockfd, new_fd;
484 struct sockaddr_in their_addr;
485 int i, max_fileno, ret;
486 pid_t chld_pid;
487 fd_set rfds, wfds;
488 struct timeval *timeout;
489
490 valid_fd_012();
491 sockfd = do_inits(argc, argv);
492 repeat:
493 FD_ZERO(&rfds);
494 FD_ZERO(&wfds);
495 max_fileno = -1;
496 /* check socket and signal pipe in any case */
497 para_fd_set(sockfd, &rfds, &max_fileno);
498 para_fd_set(signal_pipe, &rfds, &max_fileno);
499 timeout = vss_preselect();
500 status_refresh();
501 for (i = 0; senders[i].name; i++) {
502 if (senders[i].status != SENDER_ON)
503 continue;
504 if (!senders[i].pre_select)
505 continue;
506 senders[i].pre_select( &max_fileno, &rfds, &wfds);
507 }
508 if (selectors[mmd->selector_num].pre_select) {
509 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
510 max_fileno = PARA_MAX(max_fileno, ret);
511 }
512 mmd_unlock();
513 ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
514 mmd_lock();
515 if (mmd->selector_change >= 0)
516 change_selector();
517 if (selectors[mmd->selector_num].post_select)
518 selectors[mmd->selector_num].post_select(&rfds, &wfds);
519 if (ret < 0)
520 goto repeat;
521 for (i = 0; senders[i].name; i++) {
522 if (senders[i].status != SENDER_ON)
523 continue;
524 if (!senders[i].post_select)
525 continue;
526 senders[i].post_select(&rfds, &wfds);
527 }
528 vss_send_chunk();
529 status_refresh();
530 if (FD_ISSET(signal_pipe, &rfds)) {
531 int sig;
532 pid_t pid;
533 sig = para_next_signal();
534 switch (sig) {
535 case SIGHUP:
536 handle_sighup();
537 break;
538 case SIGCHLD:
539 for (;;) {
540 pid = para_reap_child();
541 if (pid <= 0)
542 break;
543 if (pid != afs_pid)
544 continue;
545 PARA_EMERG_LOG("fatal: afs died\n");
546 goto genocide;
547 }
548 break;
549 /* die on sigint/sigterm. Kill all children too. */
550 case SIGINT:
551 case SIGTERM:
552 PARA_EMERG_LOG("terminating on signal %d\n", sig);
553 genocide:
554 kill(0, SIGTERM);
555 selectors[mmd->selector_num].shutdown();
556 mutex_destroy(mmd_mutex);
557 shm_detach(mmd);
558 shm_destroy(mmd_shm_id);
559
560 exit(EXIT_FAILURE);
561 }
562 }
563 if (mmd->sender_cmd_data.cmd_num >= 0) {
564 int num = mmd->sender_cmd_data.cmd_num,
565 s = mmd->sender_cmd_data.sender_num;
566
567 if (senders[s].client_cmds[num])
568 senders[s].client_cmds[num](&mmd->sender_cmd_data);
569 mmd->sender_cmd_data.cmd_num = -1;
570 }
571 if (!FD_ISSET(sockfd, &rfds))
572 goto repeat;
573
574 new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
575 if (new_fd < 0)
576 goto repeat;
577 PARA_INFO_LOG("got connection from %s, forking\n",
578 inet_ntoa(their_addr.sin_addr));
579 mmd->num_connects++;
580 mmd->active_connections++;
581 random();
582 chld_pid = fork();
583 if (chld_pid < 0) {
584 PARA_CRIT_LOG("%s", "fork failed\n");
585 goto repeat;
586 }
587 if (chld_pid) {
588 close(new_fd);
589 /* parent keeps accepting connections */
590 goto repeat;
591 }
592 alarm(ALARM_TIMEOUT);
593 close_listed_fds();
594 close(sockfd); /* child doesn't need the listener */
595 /*
596 * put info on who we are serving into argv[0] to make
597 * client ip visible in top/ps
598 */
599 for (i = argc - 1; i >= 0; i--)
600 memset(argv[i], 0, strlen(argv[i]));
601 sprintf(argv[0], "para_server (serving %s)",
602 inet_ntoa(their_addr.sin_addr));
603 return handle_connect(new_fd, &their_addr);
604 }