xref: /freebsd/usr.sbin/nscd/nscd.c (revision 7cc42f6d25ef2e19059d088fa7d4853fe9afefb5)
1 /*-
2  * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in thereg
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/event.h>
33 #include <sys/socket.h>
34 #include <sys/stat.h>
35 #include <sys/time.h>
36 #include <sys/un.h>
37 
38 #include <assert.h>
39 #include <err.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <libutil.h>
43 #include <pthread.h>
44 #include <signal.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 
50 #include "agents/passwd.h"
51 #include "agents/group.h"
52 #include "agents/services.h"
53 #include "cachelib.h"
54 #include "config.h"
55 #include "debug.h"
56 #include "log.h"
57 #include "nscdcli.h"
58 #include "parser.h"
59 #include "query.h"
60 #include "singletons.h"
61 
62 #ifndef CONFIG_PATH
63 #define CONFIG_PATH "/etc/nscd.conf"
64 #endif
65 #define DEFAULT_CONFIG_PATH	"nscd.conf"
66 
67 #define MAX_SOCKET_IO_SIZE	4096
68 
69 struct processing_thread_args {
70 	cache	the_cache;
71 	struct configuration	*the_configuration;
72 	struct runtime_env		*the_runtime_env;
73 };
74 
75 static void accept_connection(struct kevent *, struct runtime_env *,
76 	struct configuration *);
77 static void destroy_cache_(cache);
78 static void destroy_runtime_env(struct runtime_env *);
79 static cache init_cache_(struct configuration *);
80 static struct runtime_env *init_runtime_env(struct configuration *);
81 static void processing_loop(cache, struct runtime_env *,
82 	struct configuration *);
83 static void process_socket_event(struct kevent *, struct runtime_env *,
84 	struct configuration *);
85 static void process_timer_event(struct kevent *, struct runtime_env *,
86 	struct configuration *);
87 static void *processing_thread(void *);
88 static void usage(void);
89 
90 void get_time_func(struct timeval *);
91 
92 static void
93 usage(void)
94 {
95 	fprintf(stderr,
96 	    "usage: nscd [-dnst] [-i cachename] [-I cachename]\n");
97 	exit(1);
98 }
99 
100 static cache
101 init_cache_(struct configuration *config)
102 {
103 	struct cache_params params;
104 	cache retval;
105 
106 	struct configuration_entry *config_entry;
107 	size_t	size, i;
108 	int res;
109 
110 	TRACE_IN(init_cache_);
111 
112 	memset(&params, 0, sizeof(struct cache_params));
113 	params.get_time_func = get_time_func;
114 	retval = init_cache(&params);
115 
116 	size = configuration_get_entries_size(config);
117 	for (i = 0; i < size; ++i) {
118 		config_entry = configuration_get_entry(config, i);
119 	    	/*
120 	    	 * We should register common entries now - multipart entries
121 	    	 * would be registered automatically during the queries.
122 	    	 */
123 		res = register_cache_entry(retval, (struct cache_entry_params *)
124 			&config_entry->positive_cache_params);
125 		config_entry->positive_cache_entry = find_cache_entry(retval,
126 			config_entry->positive_cache_params.cep.entry_name);
127 		assert(config_entry->positive_cache_entry !=
128 			INVALID_CACHE_ENTRY);
129 
130 		res = register_cache_entry(retval, (struct cache_entry_params *)
131 			&config_entry->negative_cache_params);
132 		config_entry->negative_cache_entry = find_cache_entry(retval,
133 			config_entry->negative_cache_params.cep.entry_name);
134 		assert(config_entry->negative_cache_entry !=
135 			INVALID_CACHE_ENTRY);
136 	}
137 
138 	LOG_MSG_2("cache", "cache was successfully initialized");
139 	TRACE_OUT(init_cache_);
140 	return (retval);
141 }
142 
143 static void
144 destroy_cache_(cache the_cache)
145 {
146 	TRACE_IN(destroy_cache_);
147 	destroy_cache(the_cache);
148 	TRACE_OUT(destroy_cache_);
149 }
150 
151 /*
152  * Socket and kqueues are prepared here. We have one global queue for both
153  * socket and timers events.
154  */
155 static struct runtime_env *
156 init_runtime_env(struct configuration *config)
157 {
158 	int serv_addr_len;
159 	struct sockaddr_un serv_addr;
160 
161 	struct kevent eventlist;
162 	struct timespec timeout;
163 
164 	struct runtime_env *retval;
165 
166 	TRACE_IN(init_runtime_env);
167 	retval = calloc(1, sizeof(*retval));
168 	assert(retval != NULL);
169 
170 	retval->sockfd = socket(PF_LOCAL, SOCK_STREAM, 0);
171 
172 	if (config->force_unlink == 1)
173 		unlink(config->socket_path);
174 
175 	memset(&serv_addr, 0, sizeof(struct sockaddr_un));
176 	serv_addr.sun_family = PF_LOCAL;
177 	strlcpy(serv_addr.sun_path, config->socket_path,
178 		sizeof(serv_addr.sun_path));
179 	serv_addr_len = sizeof(serv_addr.sun_family) +
180 		strlen(serv_addr.sun_path) + 1;
181 
182 	if (bind(retval->sockfd, (struct sockaddr *)&serv_addr,
183 		serv_addr_len) == -1) {
184 		close(retval->sockfd);
185 		free(retval);
186 
187 		LOG_ERR_2("runtime environment", "can't bind socket to path: "
188 			"%s", config->socket_path);
189 		TRACE_OUT(init_runtime_env);
190 		return (NULL);
191 	}
192 	LOG_MSG_2("runtime environment", "using socket %s",
193 		config->socket_path);
194 
195 	/*
196 	 * Here we're marking socket as non-blocking and setting its backlog
197 	 * to the maximum value
198 	 */
199 	chmod(config->socket_path, config->socket_mode);
200 	listen(retval->sockfd, -1);
201 	fcntl(retval->sockfd, F_SETFL, O_NONBLOCK);
202 
203 	retval->queue = kqueue();
204 	assert(retval->queue != -1);
205 
206 	EV_SET(&eventlist, retval->sockfd, EVFILT_READ, EV_ADD | EV_ONESHOT,
207 		0, 0, 0);
208 	memset(&timeout, 0, sizeof(struct timespec));
209 	kevent(retval->queue, &eventlist, 1, NULL, 0, &timeout);
210 
211 	LOG_MSG_2("runtime environment", "successfully initialized");
212 	TRACE_OUT(init_runtime_env);
213 	return (retval);
214 }
215 
216 static void
217 destroy_runtime_env(struct runtime_env *env)
218 {
219 	TRACE_IN(destroy_runtime_env);
220 	close(env->queue);
221 	close(env->sockfd);
222 	free(env);
223 	TRACE_OUT(destroy_runtime_env);
224 }
225 
226 static void
227 accept_connection(struct kevent *event_data, struct runtime_env *env,
228 	struct configuration *config)
229 {
230 	struct kevent	eventlist[2];
231 	struct timespec	timeout;
232 	struct query_state	*qstate;
233 
234 	int	fd;
235 	int	res;
236 
237 	uid_t	euid;
238 	gid_t	egid;
239 
240 	TRACE_IN(accept_connection);
241 	fd = accept(event_data->ident, NULL, NULL);
242 	if (fd == -1) {
243 		LOG_ERR_2("accept_connection", "error %d during accept()",
244 		    errno);
245 		TRACE_OUT(accept_connection);
246 		return;
247 	}
248 
249 	if (getpeereid(fd, &euid, &egid) != 0) {
250 		LOG_ERR_2("accept_connection", "error %d during getpeereid()",
251 			errno);
252 		TRACE_OUT(accept_connection);
253 		return;
254 	}
255 
256 	qstate = init_query_state(fd, sizeof(int), euid, egid);
257 	if (qstate == NULL) {
258 		LOG_ERR_2("accept_connection", "can't init query_state");
259 		TRACE_OUT(accept_connection);
260 		return;
261 	}
262 
263 	memset(&timeout, 0, sizeof(struct timespec));
264 	EV_SET(&eventlist[0], fd, EVFILT_TIMER, EV_ADD | EV_ONESHOT,
265 		0, qstate->timeout.tv_sec * 1000, qstate);
266 	EV_SET(&eventlist[1], fd, EVFILT_READ, EV_ADD | EV_ONESHOT,
267 		NOTE_LOWAT, qstate->kevent_watermark, qstate);
268 	res = kevent(env->queue, eventlist, 2, NULL, 0, &timeout);
269 	if (res < 0)
270 		LOG_ERR_2("accept_connection", "kevent error");
271 
272 	TRACE_OUT(accept_connection);
273 }
274 
275 static void
276 process_socket_event(struct kevent *event_data, struct runtime_env *env,
277 	struct configuration *config)
278 {
279 	struct kevent	eventlist[2];
280 	struct timeval	query_timeout;
281 	struct timespec	kevent_timeout;
282 	int	nevents;
283 	int	eof_res, res;
284 	ssize_t	io_res;
285 	struct query_state *qstate;
286 
287 	TRACE_IN(process_socket_event);
288 	eof_res = event_data->flags & EV_EOF ? 1 : 0;
289 	res = 0;
290 
291 	memset(&kevent_timeout, 0, sizeof(struct timespec));
292 	EV_SET(&eventlist[0], event_data->ident, EVFILT_TIMER, EV_DELETE,
293 		0, 0, NULL);
294 	nevents = kevent(env->queue, eventlist, 1, NULL, 0, &kevent_timeout);
295 	if (nevents == -1) {
296 		if (errno == ENOENT) {
297 			/* the timer is already handling this event */
298 			TRACE_OUT(process_socket_event);
299 			return;
300 		} else {
301 			/* some other error happened */
302 			LOG_ERR_2("process_socket_event", "kevent error, errno"
303 				" is %d", errno);
304 			TRACE_OUT(process_socket_event);
305 			return;
306 		}
307 	}
308 	qstate = (struct query_state *)event_data->udata;
309 
310 	/*
311 	 * If the buffer that is to be send/received is too large,
312 	 * we send it implicitly, by using query_io_buffer_read and
313 	 * query_io_buffer_write functions in the query_state. These functions
314 	 * use the temporary buffer, which is later send/received in parts.
315 	 * The code below implements buffer splitting/mergind for send/receive
316 	 * operations. It also does the actual socket IO operations.
317 	 */
318 	if (((qstate->use_alternate_io == 0) &&
319 		(qstate->kevent_watermark <= (size_t)event_data->data)) ||
320 		((qstate->use_alternate_io != 0) &&
321 		(qstate->io_buffer_watermark <= (size_t)event_data->data))) {
322 		if (qstate->use_alternate_io != 0) {
323 			switch (qstate->io_buffer_filter) {
324 			case EVFILT_READ:
325 				io_res = query_socket_read(qstate,
326 					qstate->io_buffer_p,
327 					qstate->io_buffer_watermark);
328 				if (io_res < 0) {
329 					qstate->use_alternate_io = 0;
330 					qstate->process_func = NULL;
331 				} else {
332 					qstate->io_buffer_p += io_res;
333 					if (qstate->io_buffer_p ==
334 					    	qstate->io_buffer +
335 						qstate->io_buffer_size) {
336 						qstate->io_buffer_p =
337 						    qstate->io_buffer;
338 						qstate->use_alternate_io = 0;
339 					}
340 				}
341 			break;
342 			default:
343 			break;
344 			}
345 		}
346 
347 		if (qstate->use_alternate_io == 0) {
348 			do {
349 				res = qstate->process_func(qstate);
350 			} while ((qstate->kevent_watermark == 0) &&
351 					(qstate->process_func != NULL) &&
352 					(res == 0));
353 
354 			if (res != 0)
355 				qstate->process_func = NULL;
356 		}
357 
358 		if ((qstate->use_alternate_io != 0) &&
359 			(qstate->io_buffer_filter == EVFILT_WRITE)) {
360 			io_res = query_socket_write(qstate, qstate->io_buffer_p,
361 				qstate->io_buffer_watermark);
362 			if (io_res < 0) {
363 				qstate->use_alternate_io = 0;
364 				qstate->process_func = NULL;
365 			} else
366 				qstate->io_buffer_p += io_res;
367 		}
368 	} else {
369 		/* assuming that socket was closed */
370 		qstate->process_func = NULL;
371 		qstate->use_alternate_io = 0;
372 	}
373 
374 	if (((qstate->process_func == NULL) &&
375 	    	(qstate->use_alternate_io == 0)) ||
376 		(eof_res != 0) || (res != 0)) {
377 		destroy_query_state(qstate);
378 		close(event_data->ident);
379 		TRACE_OUT(process_socket_event);
380 		return;
381 	}
382 
383 	/* updating the query_state lifetime variable */
384 	get_time_func(&query_timeout);
385 	query_timeout.tv_usec = 0;
386 	query_timeout.tv_sec -= qstate->creation_time.tv_sec;
387 	if (query_timeout.tv_sec > qstate->timeout.tv_sec)
388 		query_timeout.tv_sec = 0;
389 	else
390 		query_timeout.tv_sec = qstate->timeout.tv_sec -
391 			query_timeout.tv_sec;
392 
393 	if ((qstate->use_alternate_io != 0) && (qstate->io_buffer_p ==
394 		qstate->io_buffer + qstate->io_buffer_size))
395 		qstate->use_alternate_io = 0;
396 
397 	if (qstate->use_alternate_io == 0) {
398 		/*
399 		 * If we must send/receive the large block of data,
400 		 * we should prepare the query_state's io_XXX fields.
401 		 * We should also substitute its write_func and read_func
402 		 * with the query_io_buffer_write and query_io_buffer_read,
403 		 * which will allow us to implicitly send/receive this large
404 		 * buffer later (in the subsequent calls to the
405 		 * process_socket_event).
406 		 */
407 		if (qstate->kevent_watermark > MAX_SOCKET_IO_SIZE) {
408 #if 0
409 			/*
410 			 * XXX: Uncommenting this code makes nscd(8) fail for
411 			 *      entries larger than a few kB, causing few second
412 			 *      worth of delay for each call to retrieve them.
413 			 */
414 			if (qstate->io_buffer != NULL)
415 				free(qstate->io_buffer);
416 
417 			qstate->io_buffer = calloc(1,
418 				qstate->kevent_watermark);
419 			assert(qstate->io_buffer != NULL);
420 
421 			qstate->io_buffer_p = qstate->io_buffer;
422 			qstate->io_buffer_size = qstate->kevent_watermark;
423 			qstate->io_buffer_filter = qstate->kevent_filter;
424 
425 			qstate->write_func = query_io_buffer_write;
426 			qstate->read_func = query_io_buffer_read;
427 
428 			if (qstate->kevent_filter == EVFILT_READ)
429 				qstate->use_alternate_io = 1;
430 #endif
431 
432 			qstate->io_buffer_watermark = MAX_SOCKET_IO_SIZE;
433 			EV_SET(&eventlist[1], event_data->ident,
434 				qstate->kevent_filter, EV_ADD | EV_ONESHOT,
435 				NOTE_LOWAT, MAX_SOCKET_IO_SIZE, qstate);
436 		} else {
437 			EV_SET(&eventlist[1], event_data->ident,
438 		    		qstate->kevent_filter, EV_ADD | EV_ONESHOT,
439 		    		NOTE_LOWAT, qstate->kevent_watermark, qstate);
440 		}
441 	} else {
442 		if (qstate->io_buffer + qstate->io_buffer_size -
443 		    	qstate->io_buffer_p <
444 			MAX_SOCKET_IO_SIZE) {
445 			qstate->io_buffer_watermark = qstate->io_buffer +
446 				qstate->io_buffer_size - qstate->io_buffer_p;
447 			EV_SET(&eventlist[1], event_data->ident,
448 			    	qstate->io_buffer_filter,
449 				EV_ADD | EV_ONESHOT, NOTE_LOWAT,
450 				qstate->io_buffer_watermark,
451 				qstate);
452 		} else {
453 			qstate->io_buffer_watermark = MAX_SOCKET_IO_SIZE;
454 			EV_SET(&eventlist[1], event_data->ident,
455 		    		qstate->io_buffer_filter, EV_ADD | EV_ONESHOT,
456 		    		NOTE_LOWAT, MAX_SOCKET_IO_SIZE, qstate);
457 		}
458 	}
459 	EV_SET(&eventlist[0], event_data->ident, EVFILT_TIMER,
460 		EV_ADD | EV_ONESHOT, 0, query_timeout.tv_sec * 1000, qstate);
461 	kevent(env->queue, eventlist, 2, NULL, 0, &kevent_timeout);
462 
463 	TRACE_OUT(process_socket_event);
464 }
465 
466 /*
467  * This routine is called if timer event has been signaled in the kqueue. It
468  * just closes the socket and destroys the query_state.
469  */
470 static void
471 process_timer_event(struct kevent *event_data, struct runtime_env *env,
472 	struct configuration *config)
473 {
474 	struct query_state	*qstate;
475 
476 	TRACE_IN(process_timer_event);
477 	qstate = (struct query_state *)event_data->udata;
478 	destroy_query_state(qstate);
479 	close(event_data->ident);
480 	TRACE_OUT(process_timer_event);
481 }
482 
483 /*
484  * Processing loop is the basic processing routine, that forms a body of each
485  * procssing thread
486  */
487 static void
488 processing_loop(cache the_cache, struct runtime_env *env,
489 	struct configuration *config)
490 {
491 	struct timespec timeout;
492 	const int eventlist_size = 1;
493 	struct kevent eventlist[eventlist_size];
494 	int nevents, i;
495 
496 	TRACE_MSG("=> processing_loop");
497 	memset(&timeout, 0, sizeof(struct timespec));
498 	memset(&eventlist, 0, sizeof(struct kevent) * eventlist_size);
499 
500 	for (;;) {
501 		nevents = kevent(env->queue, NULL, 0, eventlist,
502 	    		eventlist_size, NULL);
503 		/*
504 		 * we can only receive 1 event on success
505 		 */
506 		if (nevents == 1) {
507 			struct kevent *event_data;
508 			event_data = &eventlist[0];
509 
510 			if ((int)event_data->ident == env->sockfd) {
511 				for (i = 0; i < event_data->data; ++i)
512 				    accept_connection(event_data, env, config);
513 
514 				EV_SET(eventlist, s_runtime_env->sockfd,
515 				    EVFILT_READ, EV_ADD | EV_ONESHOT,
516 				    0, 0, 0);
517 				memset(&timeout, 0,
518 				    sizeof(struct timespec));
519 				kevent(s_runtime_env->queue, eventlist,
520 				    1, NULL, 0, &timeout);
521 
522 			} else {
523 				switch (event_data->filter) {
524 				case EVFILT_READ:
525 				case EVFILT_WRITE:
526 					process_socket_event(event_data,
527 						env, config);
528 					break;
529 				case EVFILT_TIMER:
530 					process_timer_event(event_data,
531 						env, config);
532 					break;
533 				default:
534 					break;
535 				}
536 			}
537 		} else {
538 			/* this branch shouldn't be currently executed */
539 		}
540 	}
541 
542 	TRACE_MSG("<= processing_loop");
543 }
544 
545 /*
546  * Wrapper above the processing loop function. It sets the thread signal mask
547  * to avoid SIGPIPE signals (which can happen if the client works incorrectly).
548  */
549 static void *
550 processing_thread(void *data)
551 {
552 	struct processing_thread_args	*args;
553 	sigset_t new;
554 
555 	TRACE_MSG("=> processing_thread");
556 	args = (struct processing_thread_args *)data;
557 
558 	sigemptyset(&new);
559 	sigaddset(&new, SIGPIPE);
560 	if (pthread_sigmask(SIG_BLOCK, &new, NULL) != 0)
561 		LOG_ERR_1("processing thread",
562 			"thread can't block the SIGPIPE signal");
563 
564 	processing_loop(args->the_cache, args->the_runtime_env,
565 		args->the_configuration);
566 	free(args);
567 	TRACE_MSG("<= processing_thread");
568 
569 	return (NULL);
570 }
571 
572 void
573 get_time_func(struct timeval *time)
574 {
575 	struct timespec res;
576 	memset(&res, 0, sizeof(struct timespec));
577 	clock_gettime(CLOCK_MONOTONIC, &res);
578 
579 	time->tv_sec = res.tv_sec;
580 	time->tv_usec = 0;
581 }
582 
583 /*
584  * The idea of _nss_cache_cycle_prevention_function is that nsdispatch
585  * will search for this symbol in the executable. This symbol is the
586  * attribute of the caching daemon. So, if it exists, nsdispatch won't try
587  * to connect to the caching daemon and will just ignore the 'cache'
588  * source in the nsswitch.conf. This method helps to avoid cycles and
589  * organize self-performing requests.
590  *
591  * (not actually a function; it used to be, but it doesn't make any
592  * difference, as long as it has external linkage)
593  */
594 void *_nss_cache_cycle_prevention_function;
595 
596 int
597 main(int argc, char *argv[])
598 {
599 	struct processing_thread_args *thread_args;
600 	pthread_t *threads;
601 
602 	struct pidfh *pidfile;
603 	pid_t pid;
604 
605 	char const *config_file;
606 	char const *error_str;
607 	int error_line;
608 	int i, res;
609 
610 	int trace_mode_enabled;
611 	int force_single_threaded;
612 	int do_not_daemonize;
613 	int clear_user_cache_entries, clear_all_cache_entries;
614 	char *user_config_entry_name, *global_config_entry_name;
615 	int show_statistics;
616 	int daemon_mode, interactive_mode;
617 
618 
619 	/* by default all debug messages are omitted */
620 	TRACE_OFF();
621 
622 	/* parsing command line arguments */
623 	trace_mode_enabled = 0;
624 	force_single_threaded = 0;
625 	do_not_daemonize = 0;
626 	clear_user_cache_entries = 0;
627 	clear_all_cache_entries = 0;
628 	show_statistics = 0;
629 	user_config_entry_name = NULL;
630 	global_config_entry_name = NULL;
631 	while ((res = getopt(argc, argv, "nstdi:I:")) != -1) {
632 		switch (res) {
633 		case 'n':
634 			do_not_daemonize = 1;
635 			break;
636 		case 's':
637 			force_single_threaded = 1;
638 			break;
639 		case 't':
640 			trace_mode_enabled = 1;
641 			break;
642 		case 'i':
643 			clear_user_cache_entries = 1;
644 			if (optarg != NULL)
645 				if (strcmp(optarg, "all") != 0)
646 					user_config_entry_name = strdup(optarg);
647 			break;
648 		case 'I':
649 			clear_all_cache_entries = 1;
650 			if (optarg != NULL)
651 				if (strcmp(optarg, "all") != 0)
652 					global_config_entry_name =
653 						strdup(optarg);
654 			break;
655 		case 'd':
656 			show_statistics = 1;
657 			break;
658 		case '?':
659 		default:
660 			usage();
661 			/* NOT REACHED */
662 		}
663 	}
664 
665 	daemon_mode = do_not_daemonize | force_single_threaded |
666 		trace_mode_enabled;
667 	interactive_mode = clear_user_cache_entries | clear_all_cache_entries |
668 		show_statistics;
669 
670 	if ((daemon_mode != 0) && (interactive_mode != 0)) {
671 		LOG_ERR_1("main", "daemon mode and interactive_mode arguments "
672 			"can't be used together");
673 		usage();
674 	}
675 
676 	if (interactive_mode != 0) {
677 		FILE *pidfin = fopen(DEFAULT_PIDFILE_PATH, "r");
678 		char pidbuf[256];
679 
680 		struct nscd_connection_params connection_params;
681 		nscd_connection connection;
682 
683 		int result;
684 
685 		if (pidfin == NULL)
686 			errx(EXIT_FAILURE, "There is no daemon running.");
687 
688 		memset(pidbuf, 0, sizeof(pidbuf));
689 		fread(pidbuf, sizeof(pidbuf) - 1, 1, pidfin);
690 		fclose(pidfin);
691 
692 		if (ferror(pidfin) != 0)
693 			errx(EXIT_FAILURE, "Can't read from pidfile.");
694 
695 		if (sscanf(pidbuf, "%d", &pid) != 1)
696 			errx(EXIT_FAILURE, "Invalid pidfile.");
697 		LOG_MSG_1("main", "daemon PID is %d", pid);
698 
699 
700 		memset(&connection_params, 0,
701 			sizeof(struct nscd_connection_params));
702 		connection_params.socket_path = DEFAULT_SOCKET_PATH;
703 		connection = open_nscd_connection__(&connection_params);
704 		if (connection == INVALID_NSCD_CONNECTION)
705 			errx(EXIT_FAILURE, "Can't connect to the daemon.");
706 
707 		if (clear_user_cache_entries != 0) {
708 			result = nscd_transform__(connection,
709 				user_config_entry_name, TT_USER);
710 			if (result != 0)
711 				LOG_MSG_1("main",
712 					"user cache transformation failed");
713 			else
714 				LOG_MSG_1("main",
715 					"user cache_transformation "
716 					"succeeded");
717 		}
718 
719 		if (clear_all_cache_entries != 0) {
720 			if (geteuid() != 0)
721 				errx(EXIT_FAILURE, "Only root can initiate "
722 					"global cache transformation.");
723 
724 			result = nscd_transform__(connection,
725 				global_config_entry_name, TT_ALL);
726 			if (result != 0)
727 				LOG_MSG_1("main",
728 					"global cache transformation "
729 					"failed");
730 			else
731 				LOG_MSG_1("main",
732 					"global cache transformation "
733 					"succeeded");
734 		}
735 
736 		close_nscd_connection__(connection);
737 
738 		free(user_config_entry_name);
739 		free(global_config_entry_name);
740 		return (EXIT_SUCCESS);
741 	}
742 
743 	pidfile = pidfile_open(DEFAULT_PIDFILE_PATH, 0644, &pid);
744 	if (pidfile == NULL) {
745 		if (errno == EEXIST)
746 			errx(EXIT_FAILURE, "Daemon already running, pid: %d.",
747 				pid);
748 		warn("Cannot open or create pidfile");
749 	}
750 
751 	if (trace_mode_enabled == 1)
752 		TRACE_ON();
753 
754 	/* blocking the main thread from receiving SIGPIPE signal */
755 	sigblock(sigmask(SIGPIPE));
756 
757 	/* daemonization */
758 	if (do_not_daemonize == 0) {
759 		res = daemon(0, trace_mode_enabled == 0 ? 0 : 1);
760 		if (res != 0) {
761 			LOG_ERR_1("main", "can't daemonize myself: %s",
762 		    		strerror(errno));
763 			pidfile_remove(pidfile);
764 			goto fin;
765 		} else
766 			LOG_MSG_1("main", "successfully daemonized");
767 	}
768 
769 	pidfile_write(pidfile);
770 
771 	s_agent_table = init_agent_table();
772 	register_agent(s_agent_table, init_passwd_agent());
773 	register_agent(s_agent_table, init_passwd_mp_agent());
774 	register_agent(s_agent_table, init_group_agent());
775 	register_agent(s_agent_table, init_group_mp_agent());
776 	register_agent(s_agent_table, init_services_agent());
777 	register_agent(s_agent_table, init_services_mp_agent());
778 	LOG_MSG_1("main", "request agents registered successfully");
779 
780 	/*
781  	 * Hosts agent can't work properly until we have access to the
782 	 * appropriate dtab structures, which are used in nsdispatch
783 	 * calls
784 	 *
785 	 register_agent(s_agent_table, init_hosts_agent());
786 	*/
787 
788 	/* configuration initialization */
789 	s_configuration = init_configuration();
790 	fill_configuration_defaults(s_configuration);
791 
792 	error_str = NULL;
793 	error_line = 0;
794 	config_file = CONFIG_PATH;
795 
796 	res = parse_config_file(s_configuration, config_file, &error_str,
797 		&error_line);
798 	if ((res != 0) && (error_str == NULL)) {
799 		config_file = DEFAULT_CONFIG_PATH;
800 		res = parse_config_file(s_configuration, config_file,
801 			&error_str, &error_line);
802 	}
803 
804 	if (res != 0) {
805 		if (error_str != NULL) {
806 		LOG_ERR_1("main", "error in configuration file(%s, %d): %s\n",
807 			config_file, error_line, error_str);
808 		} else {
809 		LOG_ERR_1("main", "no configuration file found "
810 		    	"- was looking for %s and %s",
811 			CONFIG_PATH, DEFAULT_CONFIG_PATH);
812 		}
813 		destroy_configuration(s_configuration);
814 		return (-1);
815 	}
816 
817 	if (force_single_threaded == 1)
818 		s_configuration->threads_num = 1;
819 
820 	/* cache initialization */
821 	s_cache = init_cache_(s_configuration);
822 	if (s_cache == NULL) {
823 		LOG_ERR_1("main", "can't initialize the cache");
824 		destroy_configuration(s_configuration);
825 		return (-1);
826 	}
827 
828 	/* runtime environment initialization */
829 	s_runtime_env = init_runtime_env(s_configuration);
830 	if (s_runtime_env == NULL) {
831 		LOG_ERR_1("main", "can't initialize the runtime environment");
832 		destroy_configuration(s_configuration);
833 		destroy_cache_(s_cache);
834 		return (-1);
835 	}
836 
837 	if (s_configuration->threads_num > 1) {
838 		threads = calloc(s_configuration->threads_num,
839 			sizeof(*threads));
840 		for (i = 0; i < s_configuration->threads_num; ++i) {
841 			thread_args = malloc(
842 				sizeof(*thread_args));
843 			thread_args->the_cache = s_cache;
844 			thread_args->the_runtime_env = s_runtime_env;
845 			thread_args->the_configuration = s_configuration;
846 
847 			LOG_MSG_1("main", "thread #%d was successfully created",
848 				i);
849 			pthread_create(&threads[i], NULL, processing_thread,
850 				thread_args);
851 
852 			thread_args = NULL;
853 		}
854 
855 		for (i = 0; i < s_configuration->threads_num; ++i)
856 			pthread_join(threads[i], NULL);
857 	} else {
858 		LOG_MSG_1("main", "working in single-threaded mode");
859 		processing_loop(s_cache, s_runtime_env, s_configuration);
860 	}
861 
862 fin:
863 	/* runtime environment destruction */
864 	destroy_runtime_env(s_runtime_env);
865 
866 	/* cache destruction */
867 	destroy_cache_(s_cache);
868 
869 	/* configuration destruction */
870 	destroy_configuration(s_configuration);
871 
872 	/* agents table destruction */
873 	destroy_agent_table(s_agent_table);
874 
875 	pidfile_remove(pidfile);
876 	return (EXIT_SUCCESS);
877 }
878