dada53e57746f6f77a13eebb9b14ec97f07f7d55
[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
20 #include "server.cmdline.h"
21 #include "afs.h"
22 #include "server.h"
23 #include "vss.h"
24 #include "config.h"
25 #include "close_on_fork.h"
26 #include "send.h"
27 #include "error.h"
28 #include "net.h"
29 #include "daemon.h"
30 #include "string.h"
31 #include "ipc.h"
32 #include "fd.h"
33 #include "signal.h"
34 #include "user_list.h"
35
36 /** define the array of error lists needed by para_server */
37 INIT_SERVER_ERRLISTS;
38
39 /** shut down non-authorized connections after that many seconds */
40 #define ALARM_TIMEOUT 10
41
42 /**
43 * pointer to shared memory area for communication between para_server
44 * and its children. exported to vss.c. command.c and to all selectors.
45 */
46 struct misc_meta_data *mmd;
47
48 /**
49 * the configuration of para_server
50 *
51 * It also contains the options for all audio file selectors, audio format handler
52 * and all supported senders.
53 */
54 struct server_args_info conf;
55
56 /** the file containing user information (public key, permissions) */
57 char *user_list_file = NULL;
58
59 extern void dccp_send_init(struct sender *);
60 extern void http_send_init(struct sender *);
61 extern void ortp_send_init(struct sender *);
62
63 /* TODO: This is better handled by autoconf */
64 /** the list of supported audio file selectors */
65 struct audio_file_selector selectors[] = {
66 {
67 .name = "random",
68 .init = random_selector_init,
69 .update_audio_file = NULL,
70 },
71 {
72 .name = "playlist",
73 .init = playlist_selector_init,
74 .update_audio_file = NULL,
75 .pre_select = NULL,
76 .post_select = NULL,
77 },
78 #ifdef HAVE_MYSQL
79 {
80 .name = "mysql",
81 .init = mysql_selector_init,
82 .update_audio_file = NULL,
83 .pre_select = NULL,
84 .post_select = NULL,
85 },
86 #endif
87 {
88 .name = NULL,
89 }
90 };
91
92 /** the list of supported senders */
93 struct sender senders[] = {
94 {
95 .name = "http",
96 .init = http_send_init,
97 },
98 {
99 .name = "dccp",
100 .init = dccp_send_init,
101 },
102 #ifdef HAVE_ORTP
103 {
104 .name = "ortp",
105 .init = ortp_send_init,
106 },
107 #endif
108 {
109 .name = NULL,
110 }
111 };
112
113
114 /* global variables for server-internal use */
115 static FILE *logfile;
116 static int mmd_mutex, mmd_shm_id;
117 static int signal_pipe;
118
119 /**
120 * para_server's log function
121 *
122 * \param ll the log level
123 * \param fmt the format string describing the log message
124 */
125 void para_log(int ll, const char* fmt,...)
126 {
127 va_list argp;
128 FILE *outfd;
129 struct tm *tm;
130 time_t t1;
131 char str[MAXLINE] = "";
132 pid_t mypid;
133
134 if (ll < conf.loglevel_arg)
135 return;
136 outfd = logfile? logfile : stderr;
137 time(&t1);
138 tm = localtime(&t1);
139 strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
140 fprintf(outfd, "%s ", str);
141 if (conf.loglevel_arg <= INFO)
142 fprintf(outfd, "%i: ", ll);
143 mypid = getpid();
144 if (conf.loglevel_arg <= INFO)
145 fprintf(outfd, "(%d) ", mypid);
146 va_start(argp, fmt);
147 vfprintf(outfd, fmt, argp);
148 va_end(argp);
149 }
150
151 /*
152 * setup shared memory area and get mutex for locking
153 */
154 static void shm_init(void)
155 {
156 void *shm;
157 int ret = shm_new(sizeof(struct misc_meta_data));
158
159 if (ret < 0)
160 goto err_out;
161
162 ret = shm_attach(ret, ATTACH_RW, &shm);
163 if (ret < 0)
164 goto err_out;
165 mmd = shm;
166 mmd_shm_id = ret;
167
168 ret = mutex_new();
169 if (ret < 0)
170 goto err_out;
171 mmd_mutex = ret;
172
173 mmd->selector_num = 0;
174 mmd->num_played = 0;
175 mmd->num_commands = 0;
176 mmd->events = 0;
177 mmd->num_connects = 0;
178 mmd->active_connections = 0;
179 strcpy(mmd->filename, "(none)");
180 mmd->audio_format = -1;
181 mmd->vss_status_flags = VSS_NEXT;
182 mmd->new_vss_status_flags = VSS_NEXT;
183 mmd->sender_cmd_data.cmd_num = -1;
184 return;
185 err_out:
186 PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
187 exit(EXIT_FAILURE);
188 }
189
190 /**
191 * lock the shared memory area containing the mmd struct
192 *
193 * \sa semop(2), struct misc_meta_data
194 */
195 void mmd_lock(void)
196 {
197 mutex_lock(mmd_mutex);
198 }
199
200 /**
201 * unlock the shared memory area containing the mmd struct
202 *
203 * \sa semop(2), struct misc_meta_data
204 */
205
206 void mmd_unlock(void)
207 {
208 mutex_unlock(mmd_mutex);
209 }
210
211 static void parse_config(int override)
212 {
213 char *home = para_homedir();
214 struct stat statbuf;
215 int ret;
216 char *cf;
217
218 if (conf.config_file_given)
219 cf = conf.config_file_arg;
220 else
221 cf = make_message("%s/.paraslash/server.conf", home);
222 free(user_list_file);
223 if (!conf.user_list_given)
224 user_list_file = make_message("%s/.paraslash/server.users", home);
225 else
226 user_list_file = para_strdup(conf.user_list_arg);
227 ret = stat(cf, &statbuf);
228 if (ret && conf.config_file_given) {
229 ret = -1;
230 PARA_EMERG_LOG("can not stat config file %s\n", cf);
231 goto out;
232 }
233 if (!ret) {
234 int tmp = conf.daemon_given;
235 server_cmdline_parser_configfile(cf, &conf, override, 0, 0);
236 conf.daemon_given = tmp;
237 }
238 /* logfile */
239 if (!conf.logfile_given && conf.daemon_given) {
240 ret = -1;
241 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
242 goto out;
243 }
244 if (conf.logfile_given)
245 logfile = open_log(conf.logfile_arg);
246 ret = 1;
247 out:
248 free(cf);
249 free(home);
250 if (ret > 0)
251 return;
252 free(user_list_file);
253 user_list_file = NULL;
254 exit(EXIT_FAILURE);
255 }
256
257 static void setup_signal_handling(void)
258 {
259 int ret = 0;
260
261 signal_pipe = para_signal_init();
262 PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
263 ret += para_install_sighandler(SIGINT);
264 ret += para_install_sighandler(SIGTERM);
265 ret += para_install_sighandler(SIGHUP);
266 ret += para_install_sighandler(SIGCHLD);
267 ret += para_install_sighandler(SIGUSR1);
268 signal(SIGPIPE, SIG_IGN);
269 if (ret != 5) {
270 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
271 exit(EXIT_FAILURE);
272 }
273 }
274
275 static void init_selector(void)
276 {
277 int i, ret;
278
279 mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
280 if (!conf.selector_given)
281 goto random;
282 for (i = 0; selectors[i].name; i++) {
283 if (strcmp(selectors[i].name, conf.selector_arg))
284 continue;
285 PARA_NOTICE_LOG("initializing %s audio file selector\n",
286 selectors[i].name);
287 ret = selectors[i].init(&selectors[i]);
288 if (ret < 0) {
289 PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
290 break;
291 }
292 mmd->selector_num = i;
293 return;
294 }
295 PARA_WARNING_LOG("%s", "falling back to the random selector\n");
296 random:
297 mmd->selector_num = 0;
298 selectors[0].init(&selectors[0]); /* always successful */
299 }
300
301 static unsigned init_network(void)
302 {
303 int fd, ret = init_tcp_socket(conf.port_arg);
304
305 if (ret < 0)
306 goto err;
307 fd = ret;
308 ret = mark_fd_nonblock(fd);
309 if (ret < 0)
310 goto err;
311 return fd;
312 err:
313 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
314 exit(EXIT_FAILURE);
315 }
316
317 static void init_random_seed(void)
318 {
319 int fd, ret = -1;
320 unsigned int seed;
321 size_t len = sizeof(unsigned int);
322
323 fd = open("/dev/urandom", O_RDONLY);
324 if (fd < 0)
325 goto out;
326 ret = -2;
327 if (read(fd, &seed, len) != len)
328 goto out;
329 srandom(seed);
330 ret = 1;
331 out:
332 if (fd >= 0)
333 close(fd);
334 if (ret > 0)
335 return;
336 PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
337 ret);
338 exit(EXIT_FAILURE);
339 }
340
341 static unsigned do_inits(int argc, char **argv)
342 {
343 /* connector's address information */
344 int sockfd;
345
346 init_random_seed();
347 /* parse command line options */
348 server_cmdline_parser(argc, argv, &conf);
349 HANDLE_VERSION_FLAG("server", conf);
350 para_drop_privileges(conf.user_arg, conf.group_arg);
351 /* parse config file, open log and set defaults */
352 parse_config(0);
353 log_welcome("para_server", conf.loglevel_arg);
354 shm_init(); /* init mmd struct */
355 server_uptime(UPTIME_SET); /* reset server uptime */
356 init_user_list(user_list_file);
357 /* become daemon */
358 if (conf.daemon_given)
359 daemon_init();
360 init_selector();
361 // PARA_ERROR_LOG("num: %d\n", mmd->selector_num);
362 PARA_NOTICE_LOG("%s", "initializing virtual streaming system\n");
363 vss_init();
364 mmd->server_pid = getpid();
365 setup_signal_handling();
366 mmd_lock();
367 /* init network socket */
368 PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
369 sockfd = init_network();
370 PARA_NOTICE_LOG("%s", "init complete\n");
371 return sockfd;
372 }
373
374 static void change_selector(void)
375 {
376 int ret, old = mmd->selector_num, new = mmd->selector_change;
377
378 selectors[old].shutdown();
379 ret = selectors[new].init(&selectors[new]);
380 mmd->selector_change = -1; /* reset */
381 if (ret >= 0) {
382 mmd->selector_num = new;
383 return;
384 }
385 /* init failed */
386 PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
387 selectors[0].init(&selectors[0]);
388 mmd->selector_num = 0;
389 }
390
391 /*
392 * called when server gets SIGHUP or when client invokes hup command.
393 */
394 static void handle_sighup(void)
395 {
396 PARA_NOTICE_LOG("%s", "SIGHUP\n");
397 close_log(logfile); /* gets reopened if necessary by parse_config */
398 logfile = NULL;
399 parse_config(1); /* reopens log */
400 mmd->selector_change = mmd->selector_num; /* do not change selector.. */
401 change_selector(); /* .. just reload */
402 init_user_list(user_list_file); /* reload user list */
403 }
404
405 static void status_refresh(void)
406 {
407 static int prev_uptime = -1, prev_events = -1;
408 int uptime = server_uptime(UPTIME_GET), ret = 1;
409
410 if (prev_events != mmd->events)
411 goto out;
412 if (mmd->new_vss_status_flags != mmd->vss_status_flags)
413 goto out;
414 if (uptime / 60 != prev_uptime / 60)
415 goto out;
416 ret = 0;
417 out:
418 prev_uptime = uptime;
419 prev_events = mmd->events;
420 mmd->vss_status_flags = mmd->new_vss_status_flags;
421 if (ret) {
422 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
423 mmd->events, mmd->audio_format);
424 killpg(0, SIGUSR1);
425 }
426 }
427
428 /**
429 * the main function of para_server
430 *
431 * \param argc usual argument count
432 * \param argv usual argument vector
433 *
434 * \return EXIT_SUCCESS or EXIT_FAILURE
435 *
436 */
437 int main(int argc, char *argv[])
438 {
439 /* listen on sock_fd, new connection on new_fd */
440 int sockfd, new_fd;
441 struct sockaddr_in their_addr;
442 int i, max_fileno, ret;
443 pid_t chld_pid;
444 fd_set rfds, wfds;
445 struct timeval *timeout;
446
447 valid_fd_012();
448 sockfd = do_inits(argc, argv);
449 repeat:
450 FD_ZERO(&rfds);
451 FD_ZERO(&wfds);
452 max_fileno = -1;
453 /* check socket and signal pipe in any case */
454 para_fd_set(sockfd, &rfds, &max_fileno);
455 para_fd_set(signal_pipe, &rfds, &max_fileno);
456 timeout = vss_preselect();
457 status_refresh();
458 for (i = 0; senders[i].name; i++) {
459 if (senders[i].status != SENDER_ON)
460 continue;
461 if (!senders[i].pre_select)
462 continue;
463 senders[i].pre_select( &max_fileno, &rfds, &wfds);
464 }
465 if (selectors[mmd->selector_num].pre_select) {
466 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
467 max_fileno = PARA_MAX(max_fileno, ret);
468 }
469 mmd_unlock();
470 ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
471 mmd_lock();
472 if (mmd->selector_change >= 0)
473 change_selector();
474 if (selectors[mmd->selector_num].post_select)
475 selectors[mmd->selector_num].post_select(&rfds, &wfds);
476 if (ret < 0)
477 goto repeat;
478 for (i = 0; senders[i].name; i++) {
479 if (senders[i].status != SENDER_ON)
480 continue;
481 if (!senders[i].post_select)
482 continue;
483 senders[i].post_select(&rfds, &wfds);
484 }
485 vss_send_chunk();
486 status_refresh();
487 if (FD_ISSET(signal_pipe, &rfds)) {
488 int sig;
489 sig = para_next_signal();
490 switch (sig) {
491 case SIGHUP:
492 handle_sighup();
493 break;
494 case SIGCHLD:
495 para_reap_children();
496 break;
497 /* die on sigint/sigterm. Kill all children too. */
498 case SIGINT:
499 case SIGTERM:
500 PARA_EMERG_LOG("terminating on signal %d\n", sig);
501 kill(0, SIGTERM);
502 selectors[mmd->selector_num].shutdown();
503 mutex_destroy(mmd_mutex);
504 shm_detach(mmd);
505 shm_destroy(mmd_shm_id);
506 exit(EXIT_FAILURE);
507 }
508 }
509 if (mmd->sender_cmd_data.cmd_num >= 0) {
510 int num = mmd->sender_cmd_data.cmd_num,
511 s = mmd->sender_cmd_data.sender_num;
512
513 if (senders[s].client_cmds[num])
514 senders[s].client_cmds[num](&mmd->sender_cmd_data);
515 mmd->sender_cmd_data.cmd_num = -1;
516 }
517 if (!FD_ISSET(sockfd, &rfds))
518 goto repeat;
519
520 new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
521 if (new_fd < 0)
522 goto repeat;
523 PARA_INFO_LOG("got connection from %s, forking\n",
524 inet_ntoa(their_addr.sin_addr));
525 mmd->num_connects++;
526 mmd->active_connections++;
527 random();
528 chld_pid = fork();
529 if (chld_pid < 0) {
530 PARA_CRIT_LOG("%s", "fork failed\n");
531 goto repeat;
532 }
533 if (chld_pid) {
534 close(new_fd);
535 /* parent keeps accepting connections */
536 goto repeat;
537 }
538 alarm(ALARM_TIMEOUT);
539 close_listed_fds();
540 close(sockfd); /* child doesn't need the listener */
541 /*
542 * put info on who we are serving into argv[0] to make
543 * client ip visible in top/ps
544 */
545 for (i = argc - 1; i >= 0; i--)
546 memset(argv[i], 0, strlen(argv[i]));
547 sprintf(argv[0], "para_server (serving %s)",
548 inet_ntoa(their_addr.sin_addr));
549 return handle_connect(new_fd, &their_addr);
550 }