7da05898b69b528563fc0e902f0568c0728752a8
[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:
14 *
15 * - The main programs: \ref server.c, \ref audiod.c, \ref client.c,
16 * \ref audioc.c, \ref fsck.c,
17 * - Server: \ref server_command, \ref sender,
18 * - Audio file selector: \ref audio_format_handler, \ref mood, \ref afs_table,
19 * - Client: \ref receiver, \ref receiver_node, \ref filter, \ref filter_node.
20 *
21 *
22 * The gory details, listed by topic:
23 *
24 * - Audio format handlers: \ref mp3_afh.c, \ref ogg_afh.c, \ref aac_afh.c,
25 * - Decoders: \ref mp3dec.c, \ref oggdec.c, \ref aacdec.c,
26 * - Volume normalizer: \ref compress.c,
27 * - Output: \ref alsa_write.c, \ref osx_write.c,
28 * - http: \ref http_recv.c, \ref http_send.c,
29 * - ortp: \ref ortp_recv.c, \ref ortp_send.c,
30 * - dccp: \ref dccp_recv.c, \ref dccp_send.c,
31 * - Audio file selector: \ref afs.c, \ref aft.c, \ref mood.c,
32 * - Afs structures: \ref afs_table, \ref audio_file_data,
33 * \ref afs_info \ref afh_info,
34 * - Afs tables: \ref aft.c, \ref mood.c, \ref playlist.c,
35 * \ref attribute.c, \ref score.c,
36 * - The virtual streaming system: \ref vss.c, \ref chunk_queue.c.
37 *
38 * Lower levels:
39 *
40 * - Scheduling: \ref sched.c, \ref sched.h,
41 * - Networking: \ref net.c,
42 * - File descriptors: \ref fd.c,
43 * - Signals: \ref signal.c,
44 * - Daemons: \ref daemon.c,
45 * - Strings: \ref string.c, \ref string.h,
46 * - Time: \ref time.c,
47 * - Spawning processes: \ref exec.c,
48 * - Inter process communication: \ref ipc.c,
49 * - The object storage layer: \ref osl.c,
50 * - Blob tables: \ref blob.c,
51 * - The error subssystem: \ref error.h.
52 * - Access control for paraslash senders: \ref acl.c, \ref acl.h.
53 *
54 * Low-level data structures:
55 *
56 * - Doubly linked lists: \ref list.h,
57 * - Red-black trees: \ref rbtree.h, \ref rbtree.c,
58 * - Ring buffer: \ref ringbuffer.c, \ref ringbuffer.h,
59 * - Hashing: \ref hash.h, \ref sha1.h, \ref sha1.c,
60 * - Crypto: \ref crypt.c.
61 *
62 */
63
64 #include <signal.h>
65 #include <dirent.h>
66
67 #include "para.h"
68 #include "error.h"
69 #include "server.cmdline.h"
70 #include "afh.h"
71 #include "string.h"
72 #include "afs.h"
73 #include "server.h"
74 #include "vss.h"
75 #include "config.h"
76 #include "close_on_fork.h"
77 #include "list.h"
78 #include "send.h"
79 #include "net.h"
80 #include "daemon.h"
81 #include "ipc.h"
82 #include "fd.h"
83 #include "sched.h"
84 #include "signal.h"
85 #include "user_list.h"
86
87 /** Define the array of error lists needed by para_server. */
88 INIT_SERVER_ERRLISTS;
89
90 /** Shut down non-authorized connections after that many seconds. */
91 #define ALARM_TIMEOUT 10
92
93 /**
94 * Pointer to shared memory area for communication between para_server
95 * and its children. Exported to vss.c. command.c and to afs.
96 */
97 struct misc_meta_data *mmd;
98
99 /**
100 * The configuration of para_server
101 *
102 * It also contains the options for the audio file selector, audio format
103 * handler and all supported senders.
104 */
105 struct server_args_info conf;
106
107 /** A random value used in child context for authentication. */
108 uint32_t afs_socket_cookie;
109
110 /** The mutex protecting the shared memory area containing the mmd struct. */
111 int mmd_mutex;
112
113 /* global variables for server-internal use */
114 static FILE *logfile;
115 /** The file containing user information (public key, permissions). */
116 static char *user_list_file = NULL;
117 static int mmd_shm_id;
118
119
120 /** The task responsible for server command handling. */
121 struct server_command_task {
122 /** TCP port on which para_server listens for connections. */
123 int listen_fd;
124 /** Copied from para_server's main function. */
125 int argc;
126 /** Argument vector passed to para_server's main function. */
127 char **argv;
128 /** The command task structure for scheduling. */
129 struct task task;
130 };
131
132 /**
133 * Para_server's log function.
134 *
135 * \param ll The log level.
136 * \param fmt The format string describing the log message.
137 */
138 void para_log(int ll, const char* fmt,...)
139 {
140 va_list argp;
141 FILE *outfd;
142 struct tm *tm;
143 time_t t1;
144 char str[MAXLINE] = "";
145 pid_t mypid;
146
147 if (ll < conf.loglevel_arg)
148 return;
149 outfd = logfile? logfile : stderr;
150 time(&t1);
151 tm = localtime(&t1);
152 strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
153 fprintf(outfd, "%s ", str);
154 if (conf.loglevel_arg <= INFO)
155 fprintf(outfd, "%i: ", ll);
156 mypid = getpid();
157 if (conf.loglevel_arg <= INFO)
158 fprintf(outfd, "(%d) ", (int)mypid);
159 va_start(argp, fmt);
160 vfprintf(outfd, fmt, argp);
161 va_end(argp);
162 }
163
164 /*
165 * setup shared memory area and get mutex for locking
166 */
167 static void shm_init(void)
168 {
169 void *shm;
170 int ret = shm_new(sizeof(struct misc_meta_data));
171
172 if (ret < 0)
173 goto err_out;
174
175 ret = shm_attach(ret, ATTACH_RW, &shm);
176 if (ret < 0)
177 goto err_out;
178 mmd = shm;
179 mmd_shm_id = ret;
180
181 ret = mutex_new();
182 if (ret < 0)
183 goto err_out;
184 mmd_mutex = ret;
185
186 mmd->num_played = 0;
187 mmd->num_commands = 0;
188 mmd->events = 0;
189 mmd->num_connects = 0;
190 mmd->active_connections = 0;
191 mmd->vss_status_flags = VSS_NEXT;
192 mmd->new_vss_status_flags = VSS_NEXT;
193 return;
194 err_out:
195 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
196 exit(EXIT_FAILURE);
197 }
198
199 static void parse_config(int override)
200 {
201 char *home = para_homedir();
202 struct stat statbuf;
203 int ret;
204 char *cf;
205
206 if (conf.config_file_given)
207 cf = para_strdup(conf.config_file_arg);
208 else
209 cf = make_message("%s/.paraslash/server.conf", home);
210 free(user_list_file);
211 if (!conf.user_list_given)
212 user_list_file = make_message("%s/.paraslash/server.users", home);
213 else
214 user_list_file = para_strdup(conf.user_list_arg);
215 ret = stat(cf, &statbuf);
216 if (ret && conf.config_file_given) {
217 ret = -1;
218 PARA_EMERG_LOG("can not stat config file %s\n", cf);
219 goto out;
220 }
221 if (!ret) {
222 int tmp = conf.daemon_given;
223 struct server_cmdline_parser_params params = {
224 .override = override,
225 .initialize = 0,
226 .check_required = 1,
227 .check_ambiguity = 0,
228 .print_errors = 1
229 };
230 server_cmdline_parser_config_file(cf, &conf, &params);
231 conf.daemon_given = tmp;
232 }
233 if (conf.logfile_given)
234 logfile = open_log(conf.logfile_arg);
235 ret = 1;
236 out:
237 free(cf);
238 free(home);
239 if (ret > 0)
240 return;
241 free(user_list_file);
242 user_list_file = NULL;
243 exit(EXIT_FAILURE);
244 }
245
246 static void signal_pre_select(struct sched *s, struct task *t)
247 {
248 struct signal_task *st = container_of(t, struct signal_task, task);
249 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
250 }
251
252 /*
253 * called when server gets SIGHUP or when client invokes hup command.
254 */
255 static void handle_sighup(void)
256 {
257 PARA_NOTICE_LOG("SIGHUP\n");
258 close_log(logfile); /* gets reopened if necessary by parse_config */
259 logfile = NULL;
260 parse_config(1); /* reopens log */
261 init_user_list(user_list_file); /* reload user list */
262 if (mmd->afs_pid)
263 kill(mmd->afs_pid, SIGHUP);
264 }
265
266 static void signal_post_select(struct sched *s, struct task *t)
267 {
268 struct signal_task *st = container_of(t, struct signal_task, task);
269
270 if (!FD_ISSET(st->fd, &s->rfds))
271 return;
272
273 st->signum = para_next_signal();
274 switch (st->signum) {
275 case SIGHUP:
276 handle_sighup();
277 break;
278 case SIGCHLD:
279 for (;;) {
280 pid_t pid;
281 int ret = para_reap_child(&pid);
282 if (ret <= 0)
283 break;
284 if (pid != mmd->afs_pid)
285 continue;
286 PARA_EMERG_LOG("fatal: afs died\n");
287 goto genocide;
288 }
289 break;
290 /* die on sigint/sigterm. Kill all children too. */
291 case SIGINT:
292 case SIGTERM:
293 PARA_EMERG_LOG("terminating on signal %d\n", st->signum);
294 genocide:
295 kill(0, SIGTERM);
296 mutex_destroy(mmd_mutex);
297 shm_detach(mmd);
298 shm_destroy(mmd_shm_id);
299
300 exit(EXIT_FAILURE);
301 }
302 }
303
304 static void init_signal_task(void)
305 {
306 static struct signal_task signal_task_struct,
307 *st = &signal_task_struct;
308
309 st->task.pre_select = signal_pre_select;
310 st->task.post_select = signal_post_select;
311 sprintf(st->task.status, "signal task");
312
313 st->fd = para_signal_init(); /* always successful */
314
315 PARA_NOTICE_LOG("setting up signal handlers\n");
316 if (para_install_sighandler(SIGINT) < 0)
317 goto err;
318 if (para_install_sighandler(SIGTERM) < 0)
319 goto err;
320 if (para_install_sighandler(SIGHUP) < 0)
321 goto err;
322 if (para_install_sighandler(SIGCHLD) < 0)
323 goto err;
324 if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
325 goto err;
326 if (signal(SIGUSR1, SIG_IGN) == SIG_ERR)
327 goto err;
328 add_close_on_fork_list(st->fd);
329 register_task(&st->task);
330 return;
331 err:
332 PARA_EMERG_LOG("could not install signal handlers\n");
333 exit(EXIT_FAILURE);
334 }
335
336 static void command_pre_select(struct sched *s, struct task *t)
337 {
338 struct server_command_task *sct = container_of(t, struct server_command_task, task);
339 para_fd_set(sct->listen_fd, &s->rfds, &s->max_fileno);
340 }
341
342 static void command_post_select(struct sched *s, struct task *t)
343 {
344 struct server_command_task *sct = container_of(t, struct server_command_task, task);
345
346 int new_fd, ret, i;
347 char *peer_name;
348 pid_t child_pid;
349
350 if (!FD_ISSET(sct->listen_fd, &s->rfds))
351 return;
352 ret = para_accept(sct->listen_fd, NULL, 0);
353 if (ret < 0)
354 goto out;
355 new_fd = ret;
356 peer_name = remote_name(new_fd);
357 PARA_INFO_LOG("got connection from %s, forking\n", peer_name);
358 mmd->num_connects++;
359 mmd->active_connections++;
360 random();
361 child_pid = fork();
362 if (child_pid < 0) {
363 ret = -ERRNO_TO_PARA_ERROR(errno);
364 goto out;
365 }
366 if (child_pid) {
367 close(new_fd);
368 /* parent keeps accepting connections */
369 return;
370 }
371 alarm(ALARM_TIMEOUT);
372 close_listed_fds();
373 para_signal_shutdown();
374 /*
375 * put info on who we are serving into argv[0] to make
376 * client ip visible in top/ps
377 */
378 for (i = sct->argc - 1; i >= 0; i--)
379 memset(sct->argv[i], 0, strlen(sct->argv[i]));
380 sprintf(sct->argv[0], "para_server (serving %s)", peer_name);
381 return handle_connect(new_fd, peer_name);
382 out:
383 if (ret < 0)
384 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
385 }
386
387 static void init_server_command_task(int argc, char **argv)
388 {
389 int ret;
390 static struct server_command_task server_command_task_struct,
391 *sct = &server_command_task_struct;
392
393 PARA_NOTICE_LOG("initializing tcp command socket\n");
394 sct->task.pre_select = command_pre_select;
395 sct->task.post_select = command_post_select;
396 sct->argc = argc;
397 sct->argv = argv;
398 ret = para_listen(AF_UNSPEC, IPPROTO_TCP, conf.port_arg);
399 if (ret < 0)
400 goto err;
401 sct->listen_fd = ret;
402 ret = mark_fd_nonblocking(sct->listen_fd);
403 if (ret < 0)
404 goto err;
405 add_close_on_fork_list(sct->listen_fd); /* child doesn't need the listener */
406 register_task(&sct->task);
407 return;
408 err:
409 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
410 exit(EXIT_FAILURE);
411 }
412
413 static void init_random_seed(void)
414 {
415 unsigned int seed;
416 int fd, ret = para_open("/dev/urandom", O_RDONLY, 0);
417
418 if (ret < 0)
419 goto err;
420 fd = ret;
421 ret = read(fd, &seed, sizeof(seed));
422 if (ret < 0) {
423 ret = -ERRNO_TO_PARA_ERROR(errno);
424 goto out;
425 }
426 if (ret != sizeof(seed)) {
427 ret = -ERRNO_TO_PARA_ERROR(EIO);
428 goto out;
429 }
430 srandom(seed);
431 ret = 1;
432 out:
433 close(fd);
434 if (ret >= 0)
435 return;
436 err:
437 PARA_EMERG_LOG("can not seed pseudo random number generator: %s\n",
438 para_strerror(-ret));
439 exit(EXIT_FAILURE);
440 }
441
442 static int init_afs(void)
443 {
444 int ret, afs_server_socket[2];
445
446 ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
447 if (ret < 0)
448 exit(EXIT_FAILURE);
449 afs_socket_cookie = para_random((uint32_t)-1);
450 mmd->afs_pid = fork();
451 if (mmd->afs_pid < 0)
452 exit(EXIT_FAILURE);
453 if (!mmd->afs_pid) { /* child (afs) */
454 close(afs_server_socket[0]);
455 afs_init(afs_socket_cookie, afs_server_socket[1]);
456 }
457 close(afs_server_socket[1]);
458 ret = mark_fd_nonblocking(afs_server_socket[0]);
459 if (ret < 0)
460 exit(EXIT_FAILURE);
461 add_close_on_fork_list(afs_server_socket[0]);
462 PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n",
463 afs_server_socket[0], (unsigned) afs_socket_cookie);
464 return afs_server_socket[0];
465 }
466
467 static void server_init(int argc, char **argv)
468 {
469 struct server_cmdline_parser_params params = {
470 .override = 0,
471 .initialize = 1,
472 .check_required = 0,
473 .check_ambiguity = 0,
474 .print_errors = 1
475 };
476 int afs_socket;
477
478 valid_fd_012();
479 init_random_seed();
480 /* parse command line options */
481 server_cmdline_parser_ext(argc, argv, &conf, &params);
482 HANDLE_VERSION_FLAG("server", conf);
483 para_drop_privileges(conf.user_arg, conf.group_arg);
484 /* parse config file, open log and set defaults */
485 parse_config(0);
486 log_welcome("para_server", conf.loglevel_arg);
487 shm_init(); /* init mmd struct */
488 server_uptime(UPTIME_SET); /* reset server uptime */
489 init_user_list(user_list_file);
490 /* become daemon */
491 if (conf.daemon_given)
492 daemon_init();
493 PARA_NOTICE_LOG("initializing audio format handlers\n");
494 afh_init();
495 init_signal_task();
496 PARA_NOTICE_LOG("initializing the audio file selector\n");
497 afs_socket = init_afs();
498 PARA_NOTICE_LOG("initializing virtual streaming system\n");
499 init_vss_task(afs_socket);
500 init_server_command_task(argc, argv);
501 PARA_NOTICE_LOG("server init complete\n");
502 }
503
504 static void status_refresh(void)
505 {
506 static int prev_uptime = -1, prev_events = -1;
507 int uptime = server_uptime(UPTIME_GET), ret = 1;
508
509 if (prev_events != mmd->events)
510 goto out;
511 if (mmd->new_vss_status_flags != mmd->vss_status_flags)
512 goto out_inc_events;
513 if (uptime / 60 != prev_uptime / 60)
514 goto out_inc_events;
515 return;
516 out_inc_events:
517 mmd->events++;
518 out:
519 prev_uptime = uptime;
520 prev_events = mmd->events;
521 mmd->vss_status_flags = mmd->new_vss_status_flags;
522 if (ret) {
523 PARA_DEBUG_LOG("%d events, forcing status update\n",
524 mmd->events);
525 killpg(0, SIGUSR1);
526 }
527 }
528
529 static int server_select(int max_fileno, fd_set *readfds, fd_set *writefds,
530 struct timeval *timeout_tv)
531 {
532 int ret;
533
534 status_refresh();
535 mutex_unlock(mmd_mutex);
536 ret = para_select(max_fileno + 1, readfds, writefds, timeout_tv);
537 mutex_lock(mmd_mutex);
538 return ret;
539 }
540
541 /**
542 * The main function of para_server.
543 *
544 * \param argc Usual argument count.
545 * \param argv Usual argument vector.
546 *
547 * \return EXIT_SUCCESS or EXIT_FAILURE.
548 */
549 int main(int argc, char *argv[])
550 {
551 int ret;
552 static struct sched s = {
553 .default_timeout = {
554 .tv_sec = 1,
555 .tv_usec = 0
556 },
557 .select_function = server_select
558 };
559 server_init(argc, argv);
560 mutex_lock(mmd_mutex);
561 ret = schedule(&s);
562 if (ret < 0) {
563 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
564 exit(EXIT_FAILURE);
565 }
566 exit(EXIT_SUCCESS);
567 }