Merge commit 'remotes/meins/master'
[paraslash.git] / server.c
1 /*
2 * Copyright (C) 1997-2008 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 * - Access control for paraslash senders: \ref acl.c, \ref acl.h.
55 *
56 * Low-level data structures:
57 *
58 * - Doubly linked lists: \ref list.h,
59 * - Red-black trees: \ref rbtree.h, \ref rbtree.c,
60 * - Ring buffer: \ref ringbuffer.c, \ref ringbuffer.h,
61 * - Hashing: \ref hash.h, \ref sha1.h, \ref sha1.c,
62 * - Crypto: \ref crypt.c.
63 *
64 */
65
66 #include <signal.h>
67 #include <sys/types.h>
68 #include <dirent.h>
69
70 #include "para.h"
71 #include "error.h"
72 #include "server.cmdline.h"
73 #include "afh.h"
74 #include "string.h"
75 #include "afs.h"
76 #include "server.h"
77 #include "vss.h"
78 #include "config.h"
79 #include "close_on_fork.h"
80 #include "list.h"
81 #include "send.h"
82 #include "net.h"
83 #include "daemon.h"
84 #include "ipc.h"
85 #include "fd.h"
86 #include "sched.h"
87 #include "signal.h"
88 #include "user_list.h"
89
90 /** define the array of error lists needed by para_server */
91 INIT_SERVER_ERRLISTS;
92
93 /** shut down non-authorized connections after that many seconds */
94 #define ALARM_TIMEOUT 10
95
96 /**
97 * Pointer to shared memory area for communication between para_server
98 * and its children. Exported to vss.c. command.c and to afs.
99 */
100 struct misc_meta_data *mmd;
101
102 /**
103 * the configuration of para_server
104 *
105 * It also contains the options for the audio file selector, audio format
106 * handler and all supported senders.
107 */
108 struct server_args_info conf;
109
110 /** the file containing user information (public key, permissions) */
111 char *user_list_file = NULL;
112
113 extern void dccp_send_init(struct sender *);
114 extern void http_send_init(struct sender *);
115 extern void ortp_send_init(struct sender *);
116
117 /** the list of supported senders */
118 struct sender senders[] = {
119 {
120 .name = "http",
121 .init = http_send_init,
122 },
123 {
124 .name = "dccp",
125 .init = dccp_send_init,
126 },
127 #ifdef HAVE_ORTP
128 {
129 .name = "ortp",
130 .init = ortp_send_init,
131 },
132 #endif
133 {
134 .name = NULL,
135 }
136 };
137
138
139 /* global variables for server-internal use */
140 static FILE *logfile;
141 static int mmd_mutex, mmd_shm_id;
142 static int signal_pipe;
143
144 /**
145 * para_server's log function
146 *
147 * \param ll the log level
148 * \param fmt the format string describing the log message
149 */
150 void para_log(int ll, const char* fmt,...)
151 {
152 va_list argp;
153 FILE *outfd;
154 struct tm *tm;
155 time_t t1;
156 char str[MAXLINE] = "";
157 pid_t mypid;
158
159 if (ll < conf.loglevel_arg)
160 return;
161 outfd = logfile? logfile : stderr;
162 time(&t1);
163 tm = localtime(&t1);
164 strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
165 fprintf(outfd, "%s ", str);
166 if (conf.loglevel_arg <= INFO)
167 fprintf(outfd, "%i: ", ll);
168 mypid = getpid();
169 if (conf.loglevel_arg <= INFO)
170 fprintf(outfd, "(%d) ", (int)mypid);
171 va_start(argp, fmt);
172 vfprintf(outfd, fmt, argp);
173 va_end(argp);
174 }
175
176 /*
177 * setup shared memory area and get mutex for locking
178 */
179 static void shm_init(void)
180 {
181 void *shm;
182 int ret = shm_new(sizeof(struct misc_meta_data));
183
184 if (ret < 0)
185 goto err_out;
186
187 ret = shm_attach(ret, ATTACH_RW, &shm);
188 if (ret < 0)
189 goto err_out;
190 mmd = shm;
191 mmd_shm_id = ret;
192
193 ret = mutex_new();
194 if (ret < 0)
195 goto err_out;
196 mmd_mutex = ret;
197
198 mmd->num_played = 0;
199 mmd->num_commands = 0;
200 mmd->events = 0;
201 mmd->num_connects = 0;
202 mmd->active_connections = 0;
203 mmd->vss_status_flags = VSS_NEXT;
204 mmd->new_vss_status_flags = VSS_NEXT;
205 mmd->sender_cmd_data.cmd_num = -1;
206 return;
207 err_out:
208 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
209 exit(EXIT_FAILURE);
210 }
211
212 /**
213 * lock the shared memory area containing the mmd struct
214 *
215 * \sa semop(2), struct misc_meta_data.
216 */
217 void mmd_lock(void)
218 {
219 mutex_lock(mmd_mutex);
220 }
221
222 /**
223 * unlock the shared memory area containing the mmd struct
224 *
225 * \sa semop(2), struct misc_meta_data
226 */
227
228 void mmd_unlock(void)
229 {
230 mutex_unlock(mmd_mutex);
231 }
232
233 static void parse_config(int override)
234 {
235 char *home = para_homedir();
236 struct stat statbuf;
237 int ret;
238 char *cf;
239
240 if (conf.config_file_given)
241 cf = para_strdup(conf.config_file_arg);
242 else
243 cf = make_message("%s/.paraslash/server.conf", home);
244 free(user_list_file);
245 if (!conf.user_list_given)
246 user_list_file = make_message("%s/.paraslash/server.users", home);
247 else
248 user_list_file = para_strdup(conf.user_list_arg);
249 ret = stat(cf, &statbuf);
250 if (ret && conf.config_file_given) {
251 ret = -1;
252 PARA_EMERG_LOG("can not stat config file %s\n", cf);
253 goto out;
254 }
255 if (!ret) {
256 int tmp = conf.daemon_given;
257 struct server_cmdline_parser_params params = {
258 .override = override,
259 .initialize = 0,
260 .check_required = 0,
261 .check_ambiguity = 0
262 };
263 server_cmdline_parser_config_file(cf, &conf, &params);
264 conf.daemon_given = tmp;
265 }
266 if (conf.logfile_given)
267 logfile = open_log(conf.logfile_arg);
268 ret = 1;
269 out:
270 free(cf);
271 free(home);
272 if (ret > 0)
273 return;
274 free(user_list_file);
275 user_list_file = NULL;
276 exit(EXIT_FAILURE);
277 }
278
279 static void setup_signal_handling(void)
280 {
281 signal_pipe = para_signal_init(); /* always successful */
282
283 PARA_NOTICE_LOG("setting up signal handlers\n");
284 if (para_install_sighandler(SIGINT) < 0)
285 goto err;
286 if (para_install_sighandler(SIGTERM) < 0)
287 goto err;
288 if (para_install_sighandler(SIGHUP) < 0)
289 goto err;
290 if (para_install_sighandler(SIGCHLD) < 0)
291 goto err;
292 if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
293 goto err;
294 if (signal(SIGUSR1, SIG_IGN) == SIG_ERR)
295 goto err;
296 add_close_on_fork_list(signal_pipe);
297 return;
298 err:
299 PARA_EMERG_LOG("could not install signal handlers\n");
300 exit(EXIT_FAILURE);
301 }
302
303 static unsigned init_network(void)
304 {
305 int fd, ret = para_listen(AF_UNSPEC, IPPROTO_TCP, conf.port_arg);
306
307 if (ret < 0)
308 goto err;
309 fd = ret;
310 ret = mark_fd_nonblocking(fd);
311 if (ret < 0)
312 goto err;
313 add_close_on_fork_list(fd); /* child doesn't need the listener */
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 unsigned int seed;
323 int fd, ret = para_open("/dev/urandom", O_RDONLY, 0);
324
325 if (ret < 0)
326 goto err;
327 fd = ret;
328 ret = read(fd, &seed, sizeof(seed));
329 if (ret < 0) {
330 ret = -ERRNO_TO_PARA_ERROR(errno);
331 goto out;
332 }
333 if (ret != sizeof(seed)) {
334 ret = -ERRNO_TO_PARA_ERROR(EIO);
335 goto out;
336 }
337 srandom(seed);
338 ret = 1;
339 out:
340 close(fd);
341 if (ret >= 0)
342 return;
343 err:
344 PARA_EMERG_LOG("can not seed pseudo random number generator: %s\n",
345 para_strerror(-ret));
346 exit(EXIT_FAILURE);
347 }
348
349 uint32_t afs_socket_cookie;
350 int afs_socket;
351 static pid_t afs_pid;
352
353 static void init_afs(void)
354 {
355 int ret, afs_server_socket[2];
356
357 ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
358 if (ret < 0)
359 exit(EXIT_FAILURE);
360 afs_socket_cookie = para_random((uint32_t)-1);
361 afs_pid = fork();
362 if (afs_pid < 0)
363 exit(EXIT_FAILURE);
364 if (!afs_pid) { /* child (afs) */
365 close(afs_server_socket[0]);
366 afs_init(afs_socket_cookie, afs_server_socket[1]);
367 }
368 close(afs_server_socket[1]);
369 afs_socket = afs_server_socket[0];
370 ret = mark_fd_nonblocking(afs_socket);
371 if (ret < 0)
372 exit(EXIT_FAILURE);
373 add_close_on_fork_list(afs_socket);
374 PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n", afs_socket,
375 (unsigned) afs_socket_cookie);
376 }
377
378 static unsigned server_init(int argc, char **argv)
379 {
380 /* connector's address information */
381 int sockfd;
382
383 init_random_seed();
384 /* parse command line options */
385 server_cmdline_parser(argc, argv, &conf);
386 HANDLE_VERSION_FLAG("server", conf);
387 para_drop_privileges(conf.user_arg, conf.group_arg);
388 /* parse config file, open log and set defaults */
389 parse_config(0);
390 log_welcome("para_server", conf.loglevel_arg);
391 shm_init(); /* init mmd struct */
392 server_uptime(UPTIME_SET); /* reset server uptime */
393 init_user_list(user_list_file);
394 /* become daemon */
395 if (conf.daemon_given)
396 daemon_init();
397 PARA_NOTICE_LOG("initializing audio format handlers\n");
398 afh_init();
399 PARA_NOTICE_LOG("initializing virtual streaming system\n");
400 mmd->server_pid = getpid();
401 setup_signal_handling();
402 PARA_NOTICE_LOG("initializing the audio file selector\n");
403 init_afs();
404 vss_init();
405 mmd_lock();
406 /* init network socket */
407 PARA_NOTICE_LOG("initializing tcp command socket\n");
408 sockfd = init_network();
409 PARA_NOTICE_LOG("server init complete\n");
410 return sockfd;
411 }
412
413 /*
414 * called when server gets SIGHUP or when client invokes hup command.
415 */
416 static void handle_sighup(void)
417 {
418 PARA_NOTICE_LOG("SIGHUP\n");
419 close_log(logfile); /* gets reopened if necessary by parse_config */
420 logfile = NULL;
421 parse_config(1); /* reopens log */
422 init_user_list(user_list_file); /* reload user list */
423 if (afs_pid)
424 kill(afs_pid, SIGHUP);
425 }
426
427 static void status_refresh(void)
428 {
429 static int prev_uptime = -1, prev_events = -1;
430 int uptime = server_uptime(UPTIME_GET), ret = 1;
431
432 if (prev_events != mmd->events)
433 goto out;
434 if (mmd->new_vss_status_flags != mmd->vss_status_flags)
435 goto out;
436 if (uptime / 60 != prev_uptime / 60)
437 goto out;
438 ret = 0;
439 out:
440 prev_uptime = uptime;
441 prev_events = mmd->events;
442 mmd->vss_status_flags = mmd->new_vss_status_flags;
443 if (ret) {
444 PARA_DEBUG_LOG("%d events, forcing status update\n",
445 mmd->events);
446 killpg(0, SIGUSR1);
447 }
448 }
449
450 /**
451 * the main function of para_server
452 *
453 * \param argc usual argument count
454 * \param argv usual argument vector
455 *
456 * \return EXIT_SUCCESS or EXIT_FAILURE
457 *
458 */
459 int main(int argc, char *argv[])
460 {
461 /* listen on sock_fd, new connection on new_fd */
462 int sockfd, new_fd;
463 char *peer_name;
464 int i, max_fileno, ret;
465 pid_t chld_pid;
466 fd_set rfds, wfds;
467 struct timeval *timeout;
468
469 valid_fd_012();
470 sockfd = server_init(argc, argv);
471 repeat:
472 FD_ZERO(&rfds);
473 FD_ZERO(&wfds);
474 max_fileno = -1;
475 /* check socket and signal pipe in any case */
476 para_fd_set(sockfd, &rfds, &max_fileno);
477 para_fd_set(signal_pipe, &rfds, &max_fileno);
478 timeout = vss_preselect(&rfds, &wfds, &max_fileno);
479 status_refresh();
480 for (i = 0; senders[i].name; i++) {
481 if (!senders[i].pre_select)
482 continue;
483 senders[i].pre_select(&max_fileno, &rfds, &wfds);
484 }
485 mmd_unlock();
486 ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
487 mmd_lock();
488 vss_post_select(&rfds, &wfds);
489 if (ret < 0)
490 goto repeat;
491 for (i = 0; senders[i].name; i++) {
492 if (!senders[i].post_select)
493 continue;
494 senders[i].post_select(&rfds, &wfds);
495 }
496 vss_send_chunk();
497 status_refresh();
498 if (FD_ISSET(signal_pipe, &rfds)) {
499 int sig;
500 pid_t pid;
501 sig = para_next_signal();
502 switch (sig) {
503 case SIGHUP:
504 handle_sighup();
505 break;
506 case SIGCHLD:
507 for (;;) {
508 ret = para_reap_child(&pid);
509 if (ret <= 0)
510 break;
511 if (pid != afs_pid)
512 continue;
513 PARA_EMERG_LOG("fatal: afs died\n");
514 goto genocide;
515 }
516 break;
517 /* die on sigint/sigterm. Kill all children too. */
518 case SIGINT:
519 case SIGTERM:
520 PARA_EMERG_LOG("terminating on signal %d\n", sig);
521 genocide:
522 kill(0, SIGTERM);
523 mutex_destroy(mmd_mutex);
524 shm_detach(mmd);
525 shm_destroy(mmd_shm_id);
526
527 exit(EXIT_FAILURE);
528 }
529 }
530 if (mmd->sender_cmd_data.cmd_num >= 0) {
531 int num = mmd->sender_cmd_data.cmd_num,
532 s = mmd->sender_cmd_data.sender_num;
533
534 if (senders[s].client_cmds[num])
535 senders[s].client_cmds[num](&mmd->sender_cmd_data);
536 mmd->sender_cmd_data.cmd_num = -1;
537 }
538 if (!FD_ISSET(sockfd, &rfds))
539 goto repeat;
540
541 new_fd = para_accept(sockfd, NULL, 0);
542 if (new_fd < 0)
543 goto repeat;
544 peer_name = remote_name(new_fd);
545 PARA_INFO_LOG("got connection from %s, forking\n", peer_name);
546 mmd->num_connects++;
547 mmd->active_connections++;
548 random();
549 chld_pid = fork();
550 if (chld_pid < 0) {
551 PARA_CRIT_LOG("fork failed\n");
552 goto repeat;
553 }
554 if (chld_pid) {
555 close(new_fd);
556 /* parent keeps accepting connections */
557 goto repeat;
558 }
559 alarm(ALARM_TIMEOUT);
560 close_listed_fds();
561 para_signal_shutdown();
562 /*
563 * put info on who we are serving into argv[0] to make
564 * client ip visible in top/ps
565 */
566 for (i = argc - 1; i >= 0; i--)
567 memset(argv[i], 0, strlen(argv[i]));
568 sprintf(argv[0], "para_server (serving %s)", peer_name);
569 return handle_connect(new_fd, peer_name);
570 }