20efdce4e233c4a1f67a50c83a12b5b02cd9a94c
[paraslash.git] / server.c
1 /*
2 * Copyright (C) 1997-2006 Andre Noll <maan@systemlinux.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
17 */
18
19 /** \file server.c Paraslash's main server */
20
21
22 /** \mainpage Paraslash API Reference
23 *
24 * Good starting points for reading are probably \ref audio_file_selector,
25 * \ref sender, \ref receiver, \ref receiver_node, \ref filter, \ref
26 * filter_node.
27 *
28 */
29
30
31
32 #include "server.cmdline.h"
33 #include "db.h"
34 #include "server.h"
35 #include "afs.h"
36 #include "config.h"
37 #include "close_on_fork.h"
38 #include "send.h"
39 #include "error.h"
40 #include "net.h"
41 #include "daemon.h"
42 #include "string.h"
43 #include "ipc.h"
44 #include "fd.h"
45 #include "crypt.h"
46
47 /** define the array of error lists needed by para_server */
48 INIT_SERVER_ERRLISTS;
49
50 /** shut down non-authorized connections after that many seconds */
51 #define ALARM_TIMEOUT 10
52
53 /* these are exported to afs.c. command.c and to all selectors */
54 struct misc_meta_data *mmd;
55 /** the configuration of para_server
56 *
57 * It also contains the options for all audio file selectors and all supported
58 * senders.
59 */
60 struct server_args_info conf;
61 char *user_list_file = NULL;
62 struct list_head user_list;
63 extern void dccp_send_init(struct sender *);
64 extern void http_send_init(struct sender *);
65 extern void ortp_send_init(struct sender *);
66
67 /* TODO: This is better handled by autoconf */
68 /** the list of supported audio file selectors */
69 struct audio_file_selector selectors[] = {
70 {
71 .name = "random",
72 .init = random_selector_init,
73 .update_audio_file = NULL,
74 },
75 {
76 .name = "playlist",
77 .init = playlist_selector_init,
78 .update_audio_file = NULL,
79 .pre_select = NULL,
80 .post_select = NULL,
81 },
82 #ifdef HAVE_MYSQL
83 {
84 .name = "mysql",
85 .init = mysql_selector_init,
86 .update_audio_file = NULL,
87 .pre_select = NULL,
88 .post_select = NULL,
89 },
90 #endif
91 {
92 .name = NULL,
93 }
94 };
95
96 /** the list of supported senders */
97 struct sender senders[] = {
98 {
99 .name = "http",
100 .init = http_send_init,
101 },
102 {
103 .name = "dccp",
104 .init = dccp_send_init,
105 },
106 #ifdef HAVE_ORTP
107 {
108 .name = "ortp",
109 .init = ortp_send_init,
110 },
111 #endif
112 {
113 .name = NULL,
114 }
115 };
116
117
118 /* global variables for server-internal use */
119 static FILE *logfile;
120 static int mmd_mutex, mmd_shm_id;
121 static int signal_pipe;
122
123 /**
124 * para_server's log function
125 *
126 * \param ll the log level
127 * \param fmt the format string describing the log message
128 */
129 void para_log(int ll, const char* fmt,...)
130 {
131 va_list argp;
132 FILE *outfd;
133 struct tm *tm;
134 time_t t1;
135 char str[MAXLINE] = "";
136 pid_t mypid;
137
138 if (ll < conf.loglevel_arg)
139 return;
140 outfd = logfile? logfile : stderr;
141 time(&t1);
142 tm = localtime(&t1);
143 strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
144 fprintf(outfd, "%s ", str);
145 if (conf.loglevel_arg <= INFO)
146 fprintf(outfd, "%i: ", ll);
147 mypid = getpid();
148 if (conf.loglevel_arg <= INFO)
149 fprintf(outfd, "(%d) ", mypid);
150 va_start(argp, fmt);
151 vfprintf(outfd, fmt, argp);
152 va_end(argp);
153 }
154
155 /*
156 * setup shared memory area and get mutex for locking
157 */
158 static void shm_init(void)
159 {
160 void *shm;
161 int ret = shm_new(sizeof(struct misc_meta_data));
162
163 if (ret < 0)
164 goto err_out;
165
166 ret = shm_attach(ret, ATTACH_RW, &shm);
167 if (ret < 0)
168 goto err_out;
169 mmd = shm;
170 mmd_shm_id = ret;
171
172 ret = mutex_new();
173 if (ret < 0)
174 goto err_out;
175 mmd_mutex = ret;
176
177 mmd->selector_num = 0;
178 mmd->num_played = 0;
179 mmd->num_commands = 0;
180 mmd->events = 0;
181 mmd->num_connects = 0;
182 mmd->active_connections = 0;
183 strcpy(mmd->filename, "(none)");
184 mmd->audio_format = -1;
185 mmd->afs_status_flags = AFS_NEXT;
186 mmd->new_afs_status_flags = AFS_NEXT;
187 mmd->sender_cmd_data.cmd_num = -1;
188 return;
189 err_out:
190 PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
191 exit(EXIT_FAILURE);
192 }
193
194 /**
195 * lock the shared memory area containing the mmd struct
196 *
197 * \sa semop(2), struct misc_meta_data
198 */
199 void mmd_lock(void)
200 {
201 mutex_lock(mmd_mutex);
202 }
203
204 /**
205 * unlock the shared memory area containing the mmd struct
206 *
207 * \sa semop(2), struct misc_meta_data
208 */
209
210 void mmd_unlock(void)
211 {
212 mutex_unlock(mmd_mutex);
213 }
214
215 static void parse_config(int override)
216 {
217 char *home = para_homedir();
218 struct stat statbuf;
219 int ret;
220 char *cf;
221
222 if (conf.config_file_given)
223 cf = conf.config_file_arg;
224 else
225 cf = make_message("%s/.paraslash/server.conf", home);
226 free(user_list_file);
227 if (!conf.user_list_given)
228 user_list_file = make_message("%s/.paraslash/server.users", home);
229 else
230 user_list_file = para_strdup(conf.user_list_arg);
231 ret = stat(cf, &statbuf);
232 if (ret && conf.config_file_given) {
233 ret = -1;
234 PARA_EMERG_LOG("can not stat config file %s\n", cf);
235 goto out;
236 }
237 if (!ret) {
238 int tmp = conf.daemon_given;
239 server_cmdline_parser_configfile(cf, &conf, override, 0, 0);
240 conf.daemon_given = tmp;
241 }
242 /* logfile */
243 if (!conf.logfile_given && conf.daemon_given) {
244 ret = -1;
245 PARA_EMERG_LOG("%s", "daemon, but no log file\n");
246 goto out;
247 }
248 if (conf.logfile_given)
249 logfile = open_log(conf.logfile_arg);
250 ret = 1;
251 out:
252 free(cf);
253 free(home);
254 if (ret > 0)
255 return;
256 free(user_list_file);
257 user_list_file = NULL;
258 exit(EXIT_FAILURE);
259 }
260
261 static void setup_signal_handling(void)
262 {
263 int ret = 0;
264
265 signal_pipe = para_signal_init();
266 PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
267 ret += para_install_sighandler(SIGINT);
268 ret += para_install_sighandler(SIGTERM);
269 ret += para_install_sighandler(SIGHUP);
270 ret += para_install_sighandler(SIGCHLD);
271 ret += para_install_sighandler(SIGUSR1);
272 signal(SIGPIPE, SIG_IGN);
273 if (ret != 5) {
274 PARA_EMERG_LOG("%s", "could not install signal handlers\n");
275 exit(EXIT_FAILURE);
276 }
277 }
278
279 /*
280 * lookup user in user list file. Fills in a user struct containing
281 * filename of the user's public key as well as the permissions of that user.
282 * Returns 1 on success, 0 if user does not exist and < 0 on errors.
283 */
284 static void populate_user_list(void) {
285 FILE *file_ptr = NULL;
286 char *char_ptr;
287 char line[MAXLINE];
288 /* keyword, user, key, perms */
289 char w[MAXLINE], n[MAXLINE], k[MAXLINE], p[MAXLINE], tmp[4][MAXLINE];
290 int num, ret;
291
292 file_ptr = fopen(user_list_file, "r");
293 ret = -E_USERLIST;
294 if (!file_ptr)
295 goto out;
296 for (;;) {
297 struct user *u;
298 ret = para_fgets(line, MAXLINE, file_ptr);
299 if (ret < 0)
300 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
301 if (ret <= 0)
302 break;
303 if (sscanf(line,"%200s %200s %200s %200s", w, n, k, p) < 3)
304 continue;
305 if (strcmp(w, "user"))
306 continue;
307 PARA_DEBUG_LOG("found entry for %s\n", n);
308 u = para_malloc(sizeof(struct user));
309 u->name = para_strdup(n);
310 u->rsa = para_malloc(sizeof(RSA));
311 ret = get_rsa_key(k, &u->rsa, 0 /* public */);
312 if (ret < 0)
313 break;
314 u->perms = 0;
315 char_ptr = p;
316 num = sscanf(char_ptr, "%200[A-Z_],%200[A-Z_],%200[A-Z_],%200[A-Z_]",
317 tmp[0], tmp[1], tmp[2], tmp[3]);
318 PARA_DEBUG_LOG("found %i perm entries\n", num);
319 u->perms = 0;
320 while (num > 0) {
321 num--;
322 if (!strcmp(tmp[num], "AFS_READ"))
323 u->perms |= AFS_READ;
324 else if (!strcmp(tmp[num], "AFS_WRITE"))
325 u->perms |= AFS_WRITE;
326 else if (!strcmp(tmp[num], "DB_READ"))
327 u->perms |= DB_READ;
328 else if (!strcmp(tmp[num], "DB_WRITE"))
329 u->perms |= DB_WRITE;
330 else /* unknown permission */
331 PARA_WARNING_LOG("unknown permission: %s\n",
332 tmp[num]);
333 }
334 para_list_add(&u->node, &user_list);
335 }
336 out:
337 if (file_ptr)
338 fclose(file_ptr);
339 if (ret >= 0)
340 return;
341 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
342 exit(EXIT_FAILURE);
343 }
344
345 static void init_user_list(void)
346 {
347 struct user *u, *tmp;
348 static int initialized;
349
350 if (initialized) {
351 list_for_each_entry_safe(u, tmp, &user_list, node) {
352 list_del(&u->node);
353 free(u->name);
354 free(u->rsa);
355 free(u);
356 }
357 } else
358 INIT_LIST_HEAD(&user_list);
359 initialized = 1;
360 populate_user_list();
361 }
362
363 /**
364 * lookup user in user_list.
365 *
366 * \param user: must initially contain the name of the user and is filled
367 * in by this function on success.
368 *
369 * \return 1 on success and < 0 on errors.
370 */
371 int get_user(struct user *user)
372 {
373 struct user *u;
374 list_for_each_entry(u, &user_list, node) {
375 if (strcmp(u->name, user->name))
376 continue;
377 *user = *u;
378 return 1;
379 }
380 return -E_BAD_USER;
381 }
382
383 static void init_selector(void)
384 {
385 int i, ret;
386
387 mmd->selector_change = -1; /* no change nec., set to new num by com_chs */
388 if (!conf.selector_given)
389 goto random;
390 for (i = 0; selectors[i].name; i++) {
391 if (strcmp(selectors[i].name, conf.selector_arg))
392 continue;
393 PARA_NOTICE_LOG("initializing %s audio file selector\n",
394 selectors[i].name);
395 ret = selectors[i].init(&selectors[i]);
396 if (ret < 0) {
397 PARA_WARNING_LOG("%s", PARA_STRERROR(-ret));
398 break;
399 }
400 mmd->selector_num = i;
401 return;
402 }
403 PARA_WARNING_LOG("%s", "falling back to the random selector\n");
404 random:
405 mmd->selector_num = 0;
406 selectors[0].init(&selectors[0]); /* always successful */
407 }
408
409 static unsigned init_network(void)
410 {
411 int fd, ret = init_tcp_socket(conf.port_arg);
412
413 if (ret < 0)
414 goto err;
415 fd = ret;
416 ret = mark_fd_nonblock(fd);
417 if (ret < 0)
418 goto err;
419 return fd;
420 err:
421 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
422 exit(EXIT_FAILURE);
423 }
424
425 static void init_random_seed(void)
426 {
427 int fd, ret = -1, len = sizeof(unsigned int);
428 unsigned int seed;
429
430 fd = open("/dev/urandom", O_RDONLY);
431 if (fd < 0)
432 goto out;
433 ret = -2;
434 if (read(fd, &seed, len) != len)
435 goto out;
436 srandom(seed);
437 ret = 1;
438 out:
439 if (fd >= 0)
440 close(fd);
441 if (ret > 0)
442 return;
443 PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
444 ret);
445 exit(EXIT_FAILURE);
446 }
447
448 static unsigned do_inits(int argc, char **argv)
449 {
450 /* connector's address information */
451 int sockfd;
452
453 init_random_seed();
454 /* parse command line options */
455 server_cmdline_parser(argc, argv, &conf);
456 para_drop_privileges(conf.user_arg, conf.group_arg);
457 /* parse config file, open log and set defaults */
458 parse_config(0);
459 log_welcome("para_server", conf.loglevel_arg);
460 shm_init(); /* init mmd struct */
461 server_uptime(UPTIME_SET); /* reset server uptime */
462 init_user_list();
463 /* become daemon */
464 if (conf.daemon_given)
465 daemon_init();
466 init_selector();
467 PARA_NOTICE_LOG("%s", "initializing audio file sender\n");
468 /* audio file sender */
469 afs_init();
470 mmd->server_pid = getpid();
471 setup_signal_handling();
472 mmd_lock();
473 /* init network socket */
474 PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
475 sockfd = init_network();
476 PARA_NOTICE_LOG("%s", "init complete\n");
477 return sockfd;
478 }
479
480 static void change_selector(void)
481 {
482 int ret, old = mmd->selector_num, new = mmd->selector_change;
483
484 selectors[old].shutdown();
485 ret = selectors[new].init(&selectors[new]);
486 mmd->selector_change = -1; /* reset */
487 if (ret >= 0) {
488 mmd->selector_num = new;
489 return;
490 }
491 /* init failed */
492 PARA_ERROR_LOG("%s -- switching to the random selector\n", PARA_STRERROR(-ret));
493 selectors[0].init(&selectors[0]);
494 mmd->selector_num = 0;
495 }
496
497 /*
498 * called when server gets SIGHUP or when client invokes hup command.
499 */
500 static void handle_sighup(void)
501 {
502 PARA_NOTICE_LOG("%s", "SIGHUP\n");
503 close_log(logfile); /* gets reopened if necessary by parse_config */
504 logfile = NULL;
505 parse_config(1); /* reopens log */
506 mmd->selector_change = mmd->selector_num; /* do not change selector.. */
507 change_selector(); /* .. just reload */
508 }
509
510 static void status_refresh(void)
511 {
512 static int prev_uptime = -1, prev_events = -1;
513 int uptime = server_uptime(UPTIME_GET), ret = 1;
514
515 if (prev_events != mmd->events)
516 goto out;
517 if (mmd->new_afs_status_flags != mmd->afs_status_flags)
518 goto out;
519 if (uptime / 60 != prev_uptime / 60)
520 goto out;
521 ret = 0;
522 out:
523 prev_uptime = uptime;
524 prev_events = mmd->events;
525 mmd->afs_status_flags = mmd->new_afs_status_flags;
526 if (ret) {
527 PARA_DEBUG_LOG("%d events, forcing status update, af = %d\n",
528 mmd->events, mmd->audio_format);
529 killpg(0, SIGUSR1);
530 }
531 }
532
533 /*
534 * MAIN
535 */
536 int main(int argc, char *argv[])
537 {
538 /* listen on sock_fd, new connection on new_fd */
539 int sockfd, new_fd;
540 struct sockaddr_in their_addr;
541 int i, max_fileno, ret;
542 pid_t chld_pid;
543 fd_set rfds, wfds;
544 struct timeval *timeout;
545
546 valid_fd_012();
547 sockfd = do_inits(argc, argv);
548 repeat:
549 FD_ZERO(&rfds);
550 FD_ZERO(&wfds);
551 max_fileno = -1;
552 /* check socket and signal pipe in any case */
553 para_fd_set(sockfd, &rfds, &max_fileno);
554 para_fd_set(signal_pipe, &rfds, &max_fileno);
555 timeout = afs_preselect();
556 status_refresh();
557 for (i = 0; senders[i].name; i++) {
558 if (senders[i].status != SENDER_ON)
559 continue;
560 if (!senders[i].pre_select)
561 continue;
562 senders[i].pre_select( &max_fileno, &rfds, &wfds);
563 }
564 if (selectors[mmd->selector_num].pre_select) {
565 ret = selectors[mmd->selector_num].pre_select(&rfds, &wfds);
566 max_fileno = PARA_MAX(max_fileno, ret);
567 }
568 mmd_unlock();
569 ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
570 mmd_lock();
571 if (mmd->selector_change >= 0)
572 change_selector();
573 if (selectors[mmd->selector_num].post_select)
574 selectors[mmd->selector_num].post_select(&rfds, &wfds);
575 if (ret < 0)
576 goto repeat;
577 for (i = 0; senders[i].name; i++) {
578 if (senders[i].status != SENDER_ON)
579 continue;
580 if (!senders[i].post_select)
581 continue;
582 senders[i].post_select(&rfds, &wfds);
583 }
584 afs_send_chunk();
585 status_refresh();
586 if (FD_ISSET(signal_pipe, &rfds)) {
587 int sig;
588 sig = para_next_signal();
589 switch (sig) {
590 case SIGHUP:
591 handle_sighup();
592 break;
593 case SIGCHLD:
594 para_reap_children();
595 break;
596 /* die on sigint/sigterm. Kill all children too. */
597 case SIGINT:
598 case SIGTERM:
599 PARA_EMERG_LOG("terminating on signal %d\n", sig);
600 kill(0, SIGTERM);
601 selectors[mmd->selector_num].shutdown();
602 mutex_destroy(mmd_mutex);
603 shm_detach(mmd);
604 shm_destroy(mmd_shm_id);
605 exit(EXIT_FAILURE);
606 }
607 }
608 if (mmd->sender_cmd_data.cmd_num >= 0) {
609 int num = mmd->sender_cmd_data.cmd_num,
610 s = mmd->sender_cmd_data.sender_num;
611
612 if (senders[s].client_cmds[num])
613 senders[s].client_cmds[num](&mmd->sender_cmd_data);
614 mmd->sender_cmd_data.cmd_num = -1;
615 }
616 if (!FD_ISSET(sockfd, &rfds))
617 goto repeat;
618
619 new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
620 if (new_fd < 0)
621 goto repeat;
622 PARA_INFO_LOG("got connection from %s, forking\n",
623 inet_ntoa(their_addr.sin_addr));
624 mmd->num_connects++;
625 mmd->active_connections++;
626 random();
627 chld_pid = fork();
628 if (chld_pid < 0) {
629 PARA_CRIT_LOG("%s", "fork failed\n");
630 goto repeat;
631 }
632 if (chld_pid) {
633 close(new_fd);
634 /* parent keeps accepting connections */
635 goto repeat;
636 }
637 alarm(ALARM_TIMEOUT);
638 close_listed_fds();
639 close(sockfd); /* child doesn't need the listener */
640 /*
641 * put info on who we are serving into argv[0] to make
642 * client ip visible in top/ps
643 */
644 for (i = argc - 1; i >= 0; i--)
645 memset(argv[i], 0, strlen(argv[i]));
646 sprintf(argv[0], "para_server (serving %s)",
647 inet_ntoa(their_addr.sin_addr));
648 return handle_connect(new_fd, &their_addr);
649 }