server.c: Add missing newline in log message.
[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 /* logfile */
267 if (!conf.logfile_given && conf.daemon_given) {
268 ret = -1;
269 PARA_EMERG_LOG("fatal: daemon option, but no log file given\n");
270 goto out;
271 }
272 if (conf.logfile_given)
273 logfile = open_log(conf.logfile_arg);
274 ret = 1;
275 out:
276 free(cf);
277 free(home);
278 if (ret > 0)
279 return;
280 free(user_list_file);
281 user_list_file = NULL;
282 exit(EXIT_FAILURE);
283 }
284
285 static void setup_signal_handling(void)
286 {
287 signal_pipe = para_signal_init(); /* always successful */
288
289 PARA_NOTICE_LOG("setting up signal handlers\n");
290 if (para_install_sighandler(SIGINT) < 0)
291 goto err;
292 if (para_install_sighandler(SIGTERM) < 0)
293 goto err;
294 if (para_install_sighandler(SIGHUP) < 0)
295 goto err;
296 if (para_install_sighandler(SIGCHLD) < 0)
297 goto err;
298 if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
299 goto err;
300 if (signal(SIGUSR1, SIG_IGN) == SIG_ERR)
301 goto err;
302 add_close_on_fork_list(signal_pipe);
303 return;
304 err:
305 PARA_EMERG_LOG("could not install signal handlers\n");
306 exit(EXIT_FAILURE);
307 }
308
309 static unsigned init_network(void)
310 {
311 int fd, ret = para_listen(AF_UNSPEC, IPPROTO_TCP, conf.port_arg);
312
313 if (ret < 0)
314 goto err;
315 fd = ret;
316 ret = mark_fd_nonblocking(fd);
317 if (ret < 0)
318 goto err;
319 add_close_on_fork_list(fd); /* child doesn't need the listener */
320 return fd;
321 err:
322 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
323 exit(EXIT_FAILURE);
324 }
325
326 static void init_random_seed(void)
327 {
328 unsigned int seed;
329 int fd, ret = para_open("/dev/urandom", O_RDONLY, 0);
330
331 if (ret < 0)
332 goto err;
333 fd = ret;
334 ret = read(fd, &seed, sizeof(seed));
335 if (ret < 0) {
336 ret = -ERRNO_TO_PARA_ERROR(errno);
337 goto out;
338 }
339 if (ret != sizeof(seed)) {
340 ret = -ERRNO_TO_PARA_ERROR(EIO);
341 goto out;
342 }
343 srandom(seed);
344 ret = 1;
345 out:
346 close(fd);
347 if (ret >= 0)
348 return;
349 err:
350 PARA_EMERG_LOG("can not seed pseudo random number generator: %s\n",
351 para_strerror(-ret));
352 exit(EXIT_FAILURE);
353 }
354
355 uint32_t afs_socket_cookie;
356 int afs_socket;
357 static pid_t afs_pid;
358
359 static void init_afs(void)
360 {
361 int ret, afs_server_socket[2];
362
363 ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
364 if (ret < 0)
365 exit(EXIT_FAILURE);
366 afs_socket_cookie = para_random((uint32_t)-1);
367 afs_pid = fork();
368 if (afs_pid < 0)
369 exit(EXIT_FAILURE);
370 if (!afs_pid) { /* child (afs) */
371 close(afs_server_socket[0]);
372 afs_init(afs_socket_cookie, afs_server_socket[1]);
373 }
374 close(afs_server_socket[1]);
375 afs_socket = afs_server_socket[0];
376 ret = mark_fd_nonblocking(afs_socket);
377 if (ret < 0)
378 exit(EXIT_FAILURE);
379 add_close_on_fork_list(afs_socket);
380 PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n", afs_socket,
381 (unsigned) afs_socket_cookie);
382 }
383
384 static unsigned server_init(int argc, char **argv)
385 {
386 /* connector's address information */
387 int sockfd;
388
389 init_random_seed();
390 /* parse command line options */
391 server_cmdline_parser(argc, argv, &conf);
392 HANDLE_VERSION_FLAG("server", conf);
393 para_drop_privileges(conf.user_arg, conf.group_arg);
394 /* parse config file, open log and set defaults */
395 parse_config(0);
396 log_welcome("para_server", conf.loglevel_arg);
397 shm_init(); /* init mmd struct */
398 server_uptime(UPTIME_SET); /* reset server uptime */
399 init_user_list(user_list_file);
400 /* become daemon */
401 if (conf.daemon_given)
402 daemon_init();
403 PARA_NOTICE_LOG("initializing audio format handlers\n");
404 afh_init();
405 PARA_NOTICE_LOG("initializing virtual streaming system\n");
406 mmd->server_pid = getpid();
407 setup_signal_handling();
408 PARA_NOTICE_LOG("initializing the audio file selector\n");
409 init_afs();
410 vss_init();
411 mmd_lock();
412 /* init network socket */
413 PARA_NOTICE_LOG("initializing tcp command socket\n");
414 sockfd = init_network();
415 PARA_NOTICE_LOG("server init complete\n");
416 return sockfd;
417 }
418
419 /*
420 * called when server gets SIGHUP or when client invokes hup command.
421 */
422 static void handle_sighup(void)
423 {
424 PARA_NOTICE_LOG("SIGHUP\n");
425 close_log(logfile); /* gets reopened if necessary by parse_config */
426 logfile = NULL;
427 parse_config(1); /* reopens log */
428 init_user_list(user_list_file); /* reload user list */
429 if (afs_pid)
430 kill(afs_pid, SIGHUP);
431 }
432
433 static void status_refresh(void)
434 {
435 static int prev_uptime = -1, prev_events = -1;
436 int uptime = server_uptime(UPTIME_GET), ret = 1;
437
438 if (prev_events != mmd->events)
439 goto out;
440 if (mmd->new_vss_status_flags != mmd->vss_status_flags)
441 goto out;
442 if (uptime / 60 != prev_uptime / 60)
443 goto out;
444 ret = 0;
445 out:
446 prev_uptime = uptime;
447 prev_events = mmd->events;
448 mmd->vss_status_flags = mmd->new_vss_status_flags;
449 if (ret) {
450 PARA_DEBUG_LOG("%d events, forcing status update\n",
451 mmd->events);
452 killpg(0, SIGUSR1);
453 }
454 }
455
456 /**
457 * the main function of para_server
458 *
459 * \param argc usual argument count
460 * \param argv usual argument vector
461 *
462 * \return EXIT_SUCCESS or EXIT_FAILURE
463 *
464 */
465 int main(int argc, char *argv[])
466 {
467 /* listen on sock_fd, new connection on new_fd */
468 int sockfd, new_fd;
469 char *peer_name;
470 int i, max_fileno, ret;
471 pid_t chld_pid;
472 fd_set rfds, wfds;
473 struct timeval *timeout;
474
475 valid_fd_012();
476 sockfd = server_init(argc, argv);
477 repeat:
478 FD_ZERO(&rfds);
479 FD_ZERO(&wfds);
480 max_fileno = -1;
481 /* check socket and signal pipe in any case */
482 para_fd_set(sockfd, &rfds, &max_fileno);
483 para_fd_set(signal_pipe, &rfds, &max_fileno);
484 timeout = vss_preselect(&rfds, &wfds, &max_fileno);
485 status_refresh();
486 for (i = 0; senders[i].name; i++) {
487 if (!senders[i].pre_select)
488 continue;
489 senders[i].pre_select(&max_fileno, &rfds, &wfds);
490 }
491 mmd_unlock();
492 ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
493 mmd_lock();
494 vss_post_select(&rfds, &wfds);
495 if (ret < 0)
496 goto repeat;
497 for (i = 0; senders[i].name; i++) {
498 if (!senders[i].post_select)
499 continue;
500 senders[i].post_select(&rfds, &wfds);
501 }
502 vss_send_chunk();
503 status_refresh();
504 if (FD_ISSET(signal_pipe, &rfds)) {
505 int sig;
506 pid_t pid;
507 sig = para_next_signal();
508 switch (sig) {
509 case SIGHUP:
510 handle_sighup();
511 break;
512 case SIGCHLD:
513 for (;;) {
514 ret = para_reap_child(&pid);
515 if (ret <= 0)
516 break;
517 if (pid != afs_pid)
518 continue;
519 PARA_EMERG_LOG("fatal: afs died\n");
520 goto genocide;
521 }
522 break;
523 /* die on sigint/sigterm. Kill all children too. */
524 case SIGINT:
525 case SIGTERM:
526 PARA_EMERG_LOG("terminating on signal %d\n", sig);
527 genocide:
528 kill(0, SIGTERM);
529 mutex_destroy(mmd_mutex);
530 shm_detach(mmd);
531 shm_destroy(mmd_shm_id);
532
533 exit(EXIT_FAILURE);
534 }
535 }
536 if (mmd->sender_cmd_data.cmd_num >= 0) {
537 int num = mmd->sender_cmd_data.cmd_num,
538 s = mmd->sender_cmd_data.sender_num;
539
540 if (senders[s].client_cmds[num])
541 senders[s].client_cmds[num](&mmd->sender_cmd_data);
542 mmd->sender_cmd_data.cmd_num = -1;
543 }
544 if (!FD_ISSET(sockfd, &rfds))
545 goto repeat;
546
547 new_fd = para_accept(sockfd, NULL, 0);
548 if (new_fd < 0)
549 goto repeat;
550 peer_name = remote_name(new_fd);
551 PARA_INFO_LOG("got connection from %s, forking\n", peer_name);
552 mmd->num_connects++;
553 mmd->active_connections++;
554 random();
555 chld_pid = fork();
556 if (chld_pid < 0) {
557 PARA_CRIT_LOG("fork failed\n");
558 goto repeat;
559 }
560 if (chld_pid) {
561 close(new_fd);
562 /* parent keeps accepting connections */
563 goto repeat;
564 }
565 alarm(ALARM_TIMEOUT);
566 close_listed_fds();
567 para_signal_shutdown();
568 /*
569 * put info on who we are serving into argv[0] to make
570 * client ip visible in top/ps
571 */
572 for (i = argc - 1; i >= 0; i--)
573 memset(argv[i], 0, strlen(argv[i]));
574 sprintf(argv[0], "para_server (serving %s)", peer_name);
575 return handle_connect(new_fd, peer_name);
576 }