Simplify SIGUR1 handling.
[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 /**
11 * \mainpage Paraslash API Reference
12 *
13 * Starting points for getting an overview are
14 *
15 * probably:
16 *
17 * - The main programs: \ref server.c, \ref audiod.c, \ref client.c,
18 * \ref audioc.c, \ref fsck.c,
19 * - Server: \ref server_command, \ref sender,
20 * - Audio file selector: \ref audio_format_handler, \ref mood, \ref afs_table,
21 * - Client: \ref receiver, \ref receiver_node, \ref filter, \ref filter_node.
22 *
23 *
24 * The gory details, listed by topic:
25 *
26 * - Audio format handlers: \ref mp3_afh.c, \ref ogg_afh.c, \ref aac_afh.c,
27 * - Decoders: \ref mp3dec.c, \ref oggdec.c, \ref aacdec.c,
28 * - Volume normalizer: \ref compress.c,
29 * - Output: \ref alsa_write.c, \ref osx_write.c,
30 * - http: \ref http_recv.c, \ref http_send.c,
31 * - ortp: \ref ortp_recv.c, \ref ortp_send.c,
32 * - dccp: \ref dccp_recv.c, \ref dccp_send.c,
33 * - Audio file selector: \ref afs.c, \ref aft.c, \ref mood.c,
34 * - Afs structures: \ref afs_table, \ref audio_file_data,
35 * \ref afs_info \ref afh_info,
36 * - Afs tables: \ref aft.c, \ref mood.c, \ref playlist.c,
37 * \ref attribute.c, \ref score.c,
38 * - The virtual streaming system: \ref vss.c, \ref chunk_queue.c.
39 *
40 * Lower levels:
41 *
42 * - Scheduling: \ref sched.c, \ref sched.h,
43 * - Networking: \ref net.c,
44 * - File descriptors: \ref fd.c,
45 * - Signals: \ref signal.c,
46 * - Daemons: \ref daemon.c,
47 * - Strings: \ref string.c, \ref string.h,
48 * - Time: \ref time.c,
49 * - Spawning processes: \ref exec.c,
50 * - Inter process communication: \ref ipc.c,
51 * - The object storage layer: \ref osl.c,
52 * - Blob tables: \ref blob.c,
53 * - The error subssystem: \ref error.h.
54 *
55 * Low-level data structures:
56 *
57 * - Doubly linked lists: \ref list.h,
58 * - Red-black trees: \ref rbtree.h, \ref rbtree.c,
59 * - Ring buffer: \ref ringbuffer.c, \ref ringbuffer.h,
60 * - Hashing: \ref hash.h, \ref sha1.h, \ref sha1.c,
61 * - Crypto: \ref crypt.c.
62 *
63 */
64
65 #include <signal.h>
66 #include <sys/types.h>
67 #include <dirent.h>
68
69 #include "para.h"
70 #include "error.h"
71 #include "server.cmdline.h"
72 #include "afh.h"
73 #include "string.h"
74 #include "afs.h"
75 #include "server.h"
76 #include "vss.h"
77 #include "config.h"
78 #include "close_on_fork.h"
79 #include "send.h"
80 #include "net.h"
81 #include "daemon.h"
82 #include "ipc.h"
83 #include "fd.h"
84 #include "list.h"
85 #include "sched.h"
86 #include "signal.h"
87 #include "user_list.h"
88
89 /** define the array of error lists needed by para_server */
90 INIT_SERVER_ERRLISTS;
91
92 /** shut down non-authorized connections after that many seconds */
93 #define ALARM_TIMEOUT 10
94
95 /**
96 * Pointer to shared memory area for communication between para_server
97 * and its children. Exported to vss.c. command.c and to afs.
98 */
99 struct misc_meta_data *mmd;
100
101 /**
102 * the configuration of para_server
103 *
104 * It also contains the options for the audio file selector, audio format
105 * handler and all supported senders.
106 */
107 struct server_args_info conf;
108
109 /** the file containing user information (public key, permissions) */
110 char *user_list_file = NULL;
111
112 extern void dccp_send_init(struct sender *);
113 extern void http_send_init(struct sender *);
114 extern void ortp_send_init(struct sender *);
115
116 /** the list of supported senders */
117 struct sender senders[] = {
118 {
119 .name = "http",
120 .init = http_send_init,
121 },
122 {
123 .name = "dccp",
124 .init = dccp_send_init,
125 },
126 #ifdef HAVE_ORTP
127 {
128 .name = "ortp",
129 .init = ortp_send_init,
130 },
131 #endif
132 {
133 .name = NULL,
134 }
135 };
136
137
138 /* global variables for server-internal use */
139 static FILE *logfile;
140 static int mmd_mutex, mmd_shm_id;
141 static int signal_pipe;
142
143 /**
144 * para_server's log function
145 *
146 * \param ll the log level
147 * \param fmt the format string describing the log message
148 */
149 void para_log(int ll, const char* fmt,...)
150 {
151 va_list argp;
152 FILE *outfd;
153 struct tm *tm;
154 time_t t1;
155 char str[MAXLINE] = "";
156 pid_t mypid;
157
158 if (ll < conf.loglevel_arg)
159 return;
160 outfd = logfile? logfile : stderr;
161 time(&t1);
162 tm = localtime(&t1);
163 strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
164 fprintf(outfd, "%s ", str);
165 if (conf.loglevel_arg <= INFO)
166 fprintf(outfd, "%i: ", ll);
167 mypid = getpid();
168 if (conf.loglevel_arg <= INFO)
169 fprintf(outfd, "(%d) ", (int)mypid);
170 va_start(argp, fmt);
171 vfprintf(outfd, fmt, argp);
172 va_end(argp);
173 }
174
175 /*
176 * setup shared memory area and get mutex for locking
177 */
178 static void shm_init(void)
179 {
180 void *shm;
181 int ret = shm_new(sizeof(struct misc_meta_data));
182
183 if (ret < 0)
184 goto err_out;
185
186 ret = shm_attach(ret, ATTACH_RW, &shm);
187 if (ret < 0)
188 goto err_out;
189 mmd = shm;
190 mmd_shm_id = ret;
191
192 ret = mutex_new();
193 if (ret < 0)
194 goto err_out;
195 mmd_mutex = ret;
196
197 mmd->num_played = 0;
198 mmd->num_commands = 0;
199 mmd->events = 0;
200 mmd->num_connects = 0;
201 mmd->active_connections = 0;
202 mmd->vss_status_flags = VSS_NEXT;
203 mmd->new_vss_status_flags = VSS_NEXT;
204 mmd->sender_cmd_data.cmd_num = -1;
205 return;
206 err_out:
207 PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
208 exit(EXIT_FAILURE);
209 }
210
211 /**
212 * lock the shared memory area containing the mmd struct
213 *
214 * \sa semop(2), struct misc_meta_data.
215 */
216 void mmd_lock(void)
217 {
218 mutex_lock(mmd_mutex);
219 }
220
221 /**
222 * unlock the shared memory area containing the mmd struct
223 *
224 * \sa semop(2), struct misc_meta_data
225 */
226
227 void mmd_unlock(void)
228 {
229 mutex_unlock(mmd_mutex);
230 }
231
232 static void parse_config(int override)
233 {
234 char *home = para_homedir();
235 struct stat statbuf;
236 int ret;
237 char *cf;
238
239 if (conf.config_file_given)
240 cf = para_strdup(conf.config_file_arg);
241 else
242 cf = make_message("%s/.paraslash/server.conf", home);
243 free(user_list_file);
244 if (!conf.user_list_given)
245 user_list_file = make_message("%s/.paraslash/server.users", home);
246 else
247 user_list_file = para_strdup(conf.user_list_arg);
248 ret = stat(cf, &statbuf);
249 if (ret && conf.config_file_given) {
250 ret = -1;
251 PARA_EMERG_LOG("can not stat config file %s\n", cf);
252 goto out;
253 }
254 if (!ret) {
255 int tmp = conf.daemon_given;
256 struct server_cmdline_parser_params params = {
257 .override = override,
258 .initialize = 0,
259 .check_required = 0,
260 .check_ambiguity = 0
261 };
262 server_cmdline_parser_config_file(cf, &conf, &params);
263 conf.daemon_given = tmp;
264 }
265 /* logfile */
266 if (!conf.logfile_given && conf.daemon_given) {
267 ret = -1;
268 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
269 goto out;
270 }
271 if (conf.logfile_given)
272 logfile = open_log(conf.logfile_arg);
273 ret = 1;
274 out:
275 free(cf);
276 free(home);
277 if (ret > 0)
278 return;
279 free(user_list_file);
280 user_list_file = NULL;
281 exit(EXIT_FAILURE);
282 }
283
284 static void setup_signal_handling(void)
285 {
286 int ret = 0;
287
288 signal_pipe = para_signal_init();
289
290 PARA_NOTICE_LOG("setting up signal handlers\n");
291 ret += para_install_sighandler(SIGINT);
292 ret += para_install_sighandler(SIGTERM);
293 ret += para_install_sighandler(SIGHUP);
294 ret += para_install_sighandler(SIGCHLD);
295 signal(SIGPIPE, SIG_IGN);
296 signal(SIGUSR1, SIG_IGN);
297 if (ret != 4) {
298 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
299 exit(EXIT_FAILURE);
300 }
301 add_close_on_fork_list(signal_pipe);
302 }
303
304 static unsigned init_network(void)
305 {
306 int fd, ret = para_listen(AF_UNSPEC, IPPROTO_TCP, conf.port_arg);
307
308 if (ret < 0)
309 goto err;
310 fd = ret;
311 ret = mark_fd_nonblocking(fd);
312 if (ret < 0)
313 goto err;
314 add_close_on_fork_list(fd); /* child doesn't need the listener */
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;
324 unsigned int seed;
325 size_t len = sizeof(unsigned int);
326
327 fd = open("/dev/urandom", O_RDONLY);
328 if (fd < 0)
329 goto out;
330 ret = -2;
331 if (read(fd, &seed, len) != len)
332 goto out;
333 srandom(seed);
334 ret = 1;
335 out:
336 if (fd >= 0)
337 close(fd);
338 if (ret > 0)
339 return;
340 PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
341 ret);
342 exit(EXIT_FAILURE);
343 }
344
345 uint32_t afs_socket_cookie;
346 int afs_socket;
347 static pid_t afs_pid;
348
349 static void init_afs(void)
350 {
351 int ret, afs_server_socket[2];
352
353 ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
354 if (ret < 0)
355 exit(EXIT_FAILURE);
356 afs_socket_cookie = para_random((uint32_t)-1);
357 afs_pid = fork();
358 if (afs_pid < 0)
359 exit(EXIT_FAILURE);
360 if (!afs_pid) { /* child (afs) */
361 close(afs_server_socket[0]);
362 afs_init(afs_socket_cookie, afs_server_socket[1]);
363 }
364 close(afs_server_socket[1]);
365 afs_socket = afs_server_socket[0];
366 ret = mark_fd_nonblocking(afs_socket);
367 if (ret < 0)
368 exit(EXIT_FAILURE);
369 add_close_on_fork_list(afs_socket);
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 server_init(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 PARA_NOTICE_LOG("initializing audio format handlers\n");
395 afh_init();
396 PARA_NOTICE_LOG("initializing virtual streaming system\n");
397 vss_init();
398 mmd->server_pid = getpid();
399 setup_signal_handling();
400 PARA_NOTICE_LOG("initializing the audio file selector\n");
401 init_afs();
402 mmd_lock();
403 /* init network socket */
404 PARA_NOTICE_LOG("initializing tcp command socket\n");
405 sockfd = init_network();
406 PARA_NOTICE_LOG("server init complete\n");
407 return sockfd;
408 }
409
410 /*
411 * called when server gets SIGHUP or when client invokes hup command.
412 */
413 static void handle_sighup(void)
414 {
415 PARA_NOTICE_LOG("%s", "SIGHUP\n");
416 close_log(logfile); /* gets reopened if necessary by parse_config */
417 logfile = NULL;
418 parse_config(1); /* reopens log */
419 init_user_list(user_list_file); /* reload user list */
420 if (afs_pid)
421 kill(afs_pid, SIGHUP);
422 }
423
424 static void status_refresh(void)
425 {
426 static int prev_uptime = -1, prev_events = -1;
427 int uptime = server_uptime(UPTIME_GET), ret = 1;
428
429 if (prev_events != mmd->events)
430 goto out;
431 if (mmd->new_vss_status_flags != mmd->vss_status_flags)
432 goto out;
433 if (uptime / 60 != prev_uptime / 60)
434 goto out;
435 ret = 0;
436 out:
437 prev_uptime = uptime;
438 prev_events = mmd->events;
439 mmd->vss_status_flags = mmd->new_vss_status_flags;
440 if (ret) {
441 PARA_DEBUG_LOG("%d events, forcing status update\n",
442 mmd->events);
443 killpg(0, SIGUSR1);
444 }
445 }
446
447 /**
448 * the main function of para_server
449 *
450 * \param argc usual argument count
451 * \param argv usual argument vector
452 *
453 * \return EXIT_SUCCESS or EXIT_FAILURE
454 *
455 */
456 int main(int argc, char *argv[])
457 {
458 /* listen on sock_fd, new connection on new_fd */
459 int sockfd, new_fd;
460 char *peer_name;
461 int i, max_fileno, ret;
462 pid_t chld_pid;
463 fd_set rfds, wfds;
464 struct timeval *timeout;
465
466 valid_fd_012();
467 sockfd = server_init(argc, argv);
468 repeat:
469 FD_ZERO(&rfds);
470 FD_ZERO(&wfds);
471 max_fileno = -1;
472 /* check socket and signal pipe in any case */
473 para_fd_set(sockfd, &rfds, &max_fileno);
474 para_fd_set(signal_pipe, &rfds, &max_fileno);
475 timeout = vss_preselect(&rfds, &wfds, &max_fileno);
476 status_refresh();
477 for (i = 0; senders[i].name; i++) {
478 if (senders[i].status != SENDER_ON)
479 continue;
480 if (!senders[i].pre_select)
481 continue;
482 senders[i].pre_select(&max_fileno, &rfds, &wfds);
483 }
484 mmd_unlock();
485 ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
486 mmd_lock();
487 vss_post_select(&rfds, &wfds);
488 if (ret < 0)
489 goto repeat;
490 for (i = 0; senders[i].name; i++) {
491 if (senders[i].status != SENDER_ON)
492 continue;
493 if (!senders[i].post_select)
494 continue;
495 senders[i].post_select(&rfds, &wfds);
496 }
497 vss_send_chunk();
498 status_refresh();
499 if (FD_ISSET(signal_pipe, &rfds)) {
500 int sig;
501 pid_t pid;
502 sig = para_next_signal();
503 switch (sig) {
504 case SIGHUP:
505 handle_sighup();
506 break;
507 case SIGCHLD:
508 for (;;) {
509 ret = para_reap_child(&pid);
510 if (ret <= 0)
511 break;
512 if (pid != afs_pid)
513 continue;
514 PARA_EMERG_LOG("fatal: afs died\n");
515 goto genocide;
516 }
517 break;
518 /* die on sigint/sigterm. Kill all children too. */
519 case SIGINT:
520 case SIGTERM:
521 PARA_EMERG_LOG("terminating on signal %d\n", sig);
522 genocide:
523 kill(0, SIGTERM);
524 mutex_destroy(mmd_mutex);
525 shm_detach(mmd);
526 shm_destroy(mmd_shm_id);
527
528 exit(EXIT_FAILURE);
529 }
530 }
531 if (mmd->sender_cmd_data.cmd_num >= 0) {
532 int num = mmd->sender_cmd_data.cmd_num,
533 s = mmd->sender_cmd_data.sender_num;
534
535 if (senders[s].client_cmds[num])
536 senders[s].client_cmds[num](&mmd->sender_cmd_data);
537 mmd->sender_cmd_data.cmd_num = -1;
538 }
539 if (!FD_ISSET(sockfd, &rfds))
540 goto repeat;
541
542 new_fd = para_accept(sockfd, NULL, 0);
543 if (new_fd < 0)
544 goto repeat;
545 peer_name = remote_name(new_fd);
546 PARA_INFO_LOG("got connection from %s, forking\n", peer_name);
547 mmd->num_connects++;
548 mmd->active_connections++;
549 random();
550 chld_pid = fork();
551 if (chld_pid < 0) {
552 PARA_CRIT_LOG("%s", "fork failed\n");
553 goto repeat;
554 }
555 if (chld_pid) {
556 close(new_fd);
557 /* parent keeps accepting connections */
558 goto repeat;
559 }
560 alarm(ALARM_TIMEOUT);
561 close_listed_fds();
562 para_signal_shutdown();
563 /*
564 * put info on who we are serving into argv[0] to make
565 * client ip visible in top/ps
566 */
567 for (i = argc - 1; i >= 0; i--)
568 memset(argv[i], 0, strlen(argv[i]));
569 sprintf(argv[0], "para_server (serving %s)", peer_name);
570 return handle_connect(new_fd, peer_name);
571 }