xref: /freebsd/usr.sbin/nscd/nscd.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
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/types.h>
32 #include <sys/event.h>
33 #include <sys/socket.h>
34 #include <sys/time.h>
35 #include <sys/param.h>
36 #include <sys/un.h>
37 #include <assert.h>
38 #include <err.h>
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <libutil.h>
42 #include <pthread.h>
43 #include <signal.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 
49 #include "agents/passwd.h"
50 #include "agents/group.h"
51 #include "agents/services.h"
52 #include "cachelib.h"
53 #include "config.h"
54 #include "debug.h"
55 #include "log.h"
56 #include "nscdcli.h"
57 #include "parser.h"
58 #include "query.h"
59 #include "singletons.h"
60 
61 #ifndef CONFIG_PATH
62 #define CONFIG_PATH "/etc/nscd.conf"
63 #endif
64 #define DEFAULT_CONFIG_PATH	"nscd.conf"
65 
66 #define MAX_SOCKET_IO_SIZE	4096
67 
68 struct processing_thread_args {
69 	cache	the_cache;
70 	struct configuration	*the_configuration;
71 	struct runtime_env		*the_runtime_env;
72 };
73 
74 static void accept_connection(struct kevent *, struct runtime_env *,
75 	struct configuration *);
76 static void destroy_cache_(cache);
77 static void destroy_runtime_env(struct runtime_env *);
78 static cache init_cache_(struct configuration *);
79 static struct runtime_env *init_runtime_env(struct configuration *);
80 static void print_version_info(void);
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 print_version_info(void)
94 {
95 	TRACE_IN(print_version_info);
96 	printf("nscd v0.2 (20 Oct 2005)\nwas developed during SoC 2005\n");
97 	TRACE_OUT(print_version_info);
98 }
99 
100 static void
101 usage(void)
102 {
103 	fprintf(stderr,
104 	    "usage: nscd [-dnst] [-i cachename] [-I cachename]\n");
105 	exit(1);
106 }
107 
108 static cache
109 init_cache_(struct configuration *config)
110 {
111 	struct cache_params params;
112 	cache retval;
113 
114 	struct configuration_entry *config_entry;
115 	size_t	size, i;
116 	int res;
117 
118 	TRACE_IN(init_cache_);
119 
120 	memset(&params, 0, sizeof(struct cache_params));
121 	params.get_time_func = get_time_func;
122 	retval = init_cache(&params);
123 
124 	size = configuration_get_entries_size(config);
125 	for (i = 0; i < size; ++i) {
126 		config_entry = configuration_get_entry(config, i);
127 	    	/*
128 	    	 * We should register common entries now - multipart entries
129 	    	 * would be registered automatically during the queries.
130 	    	 */
131 		res = register_cache_entry(retval, (struct cache_entry_params *)
132 			&config_entry->positive_cache_params);
133 		config_entry->positive_cache_entry = find_cache_entry(retval,
134 			config_entry->positive_cache_params.entry_name);
135 		assert(config_entry->positive_cache_entry !=
136 			INVALID_CACHE_ENTRY);
137 
138 		res = register_cache_entry(retval, (struct cache_entry_params *)
139 			&config_entry->negative_cache_params);
140 		config_entry->negative_cache_entry = find_cache_entry(retval,
141 			config_entry->negative_cache_params.entry_name);
142 		assert(config_entry->negative_cache_entry !=
143 			INVALID_CACHE_ENTRY);
144 	}
145 
146 	LOG_MSG_2("cache", "cache was successfully initialized");
147 	TRACE_OUT(init_cache_);
148 	return (retval);
149 }
150 
151 static void
152 destroy_cache_(cache the_cache)
153 {
154 	TRACE_IN(destroy_cache_);
155 	destroy_cache(the_cache);
156 	TRACE_OUT(destroy_cache_);
157 }
158 
159 /*
160  * Socket and kqueues are prepared here. We have one global queue for both
161  * socket and timers events.
162  */
163 static struct runtime_env *
164 init_runtime_env(struct configuration *config)
165 {
166 	int serv_addr_len;
167 	struct sockaddr_un serv_addr;
168 
169 	struct kevent eventlist;
170 	struct timespec timeout;
171 
172 	struct runtime_env *retval;
173 
174 	TRACE_IN(init_runtime_env);
175 	retval = (struct runtime_env *)malloc(sizeof(struct runtime_env));
176 	assert(retval != NULL);
177 	memset(retval, 0, sizeof(struct runtime_env));
178 
179 	retval->sockfd = socket(PF_LOCAL, SOCK_STREAM, 0);
180 
181 	if (config->force_unlink == 1)
182 		unlink(config->socket_path);
183 
184 	memset(&serv_addr, 0, sizeof(struct sockaddr_un));
185 	serv_addr.sun_family = PF_LOCAL;
186 	strncpy(serv_addr.sun_path, config->socket_path,
187 		sizeof(serv_addr.sun_path));
188 	serv_addr_len = sizeof(serv_addr.sun_family) +
189 		strlen(serv_addr.sun_path) + 1;
190 
191 	if (bind(retval->sockfd, (struct sockaddr *)&serv_addr,
192 		serv_addr_len) == -1) {
193 		close(retval->sockfd);
194 		free(retval);
195 
196 		LOG_ERR_2("runtime environment", "can't bind socket to path: "
197 			"%s", config->socket_path);
198 		TRACE_OUT(init_runtime_env);
199 		return (NULL);
200 	}
201 	LOG_MSG_2("runtime environment", "using socket %s",
202 		config->socket_path);
203 
204 	/*
205 	 * Here we're marking socket as non-blocking and setting its backlog
206 	 * to the maximum value
207 	 */
208 	chmod(config->socket_path, config->socket_mode);
209 	listen(retval->sockfd, -1);
210 	fcntl(retval->sockfd, F_SETFL, O_NONBLOCK);
211 
212 	retval->queue = kqueue();
213 	assert(retval->queue != -1);
214 
215 	EV_SET(&eventlist, retval->sockfd, EVFILT_READ, EV_ADD | EV_ONESHOT,
216 		0, 0, 0);
217 	memset(&timeout, 0, sizeof(struct timespec));
218 	kevent(retval->queue, &eventlist, 1, NULL, 0, &timeout);
219 
220 	LOG_MSG_2("runtime environment", "successfully initialized");
221 	TRACE_OUT(init_runtime_env);
222 	return (retval);
223 }
224 
225 static void
226 destroy_runtime_env(struct runtime_env *env)
227 {
228 	TRACE_IN(destroy_runtime_env);
229 	close(env->queue);
230 	close(env->sockfd);
231 	free(env);
232 	TRACE_OUT(destroy_runtime_env);
233 }
234 
235 static void
236 accept_connection(struct kevent *event_data, struct runtime_env *env,
237 	struct configuration *config)
238 {
239 	struct kevent	eventlist[2];
240 	struct timespec	timeout;
241 	struct query_state	*qstate;
242 
243 	int	fd;
244 	int	res;
245 
246 	uid_t	euid;
247 	gid_t	egid;
248 
249 	TRACE_IN(accept_connection);
250 	fd = accept(event_data->ident, NULL, NULL);
251 	if (fd == -1) {
252 		LOG_ERR_2("accept_connection", "error %d during accept()",
253 		    errno);
254 		TRACE_OUT(accept_connection);
255 		return;
256 	}
257 
258 	if (getpeereid(fd, &euid, &egid) != 0) {
259 		LOG_ERR_2("accept_connection", "error %d during getpeereid()",
260 			errno);
261 		TRACE_OUT(accept_connection);
262 		return;
263 	}
264 
265 	qstate = init_query_state(fd, sizeof(int), euid, egid);
266 	if (qstate == NULL) {
267 		LOG_ERR_2("accept_connection", "can't init query_state");
268 		TRACE_OUT(accept_connection);
269 		return;
270 	}
271 
272 	memset(&timeout, 0, sizeof(struct timespec));
273 	EV_SET(&eventlist[0], fd, EVFILT_TIMER, EV_ADD | EV_ONESHOT,
274 		0, qstate->timeout.tv_sec * 1000, qstate);
275 	EV_SET(&eventlist[1], fd, EVFILT_READ, EV_ADD | EV_ONESHOT,
276 		NOTE_LOWAT, qstate->kevent_watermark, qstate);
277 	res = kevent(env->queue, eventlist, 2, NULL, 0, &timeout);
278 	if (res < 0)
279 		LOG_ERR_2("accept_connection", "kevent error");
280 
281 	TRACE_OUT(accept_connection);
282 }
283 
284 static void
285 process_socket_event(struct kevent *event_data, struct runtime_env *env,
286 	struct configuration *config)
287 {
288 	struct kevent	eventlist[2];
289 	struct timeval	query_timeout;
290 	struct timespec	kevent_timeout;
291 	int	nevents;
292 	int	eof_res, res;
293 	ssize_t	io_res;
294 	struct query_state *qstate;
295 
296 	TRACE_IN(process_socket_event);
297 	eof_res = event_data->flags & EV_EOF ? 1 : 0;
298 	res = 0;
299 
300 	memset(&kevent_timeout, 0, sizeof(struct timespec));
301 	EV_SET(&eventlist[0], event_data->ident, EVFILT_TIMER, EV_DELETE,
302 		0, 0, NULL);
303 	nevents = kevent(env->queue, eventlist, 1, NULL, 0, &kevent_timeout);
304 	if (nevents == -1) {
305 		if (errno == ENOENT) {
306 			/* the timer is already handling this event */
307 			TRACE_OUT(process_socket_event);
308 			return;
309 		} else {
310 			/* some other error happened */
311 			LOG_ERR_2("process_socket_event", "kevent error, errno"
312 				" is %d", errno);
313 			TRACE_OUT(process_socket_event);
314 			return;
315 		}
316 	}
317 	qstate = (struct query_state *)event_data->udata;
318 
319 	/*
320 	 * If the buffer that is to be send/received is too large,
321 	 * we send it implicitly, by using query_io_buffer_read and
322 	 * query_io_buffer_write functions in the query_state. These functions
323 	 * use the temporary buffer, which is later send/received in parts.
324 	 * The code below implements buffer splitting/mergind for send/receive
325 	 * operations. It also does the actual socket IO operations.
326 	 */
327 	if (((qstate->use_alternate_io == 0) &&
328 		(qstate->kevent_watermark <= event_data->data)) ||
329 		((qstate->use_alternate_io != 0) &&
330 		(qstate->io_buffer_watermark <= event_data->data))) {
331 		if (qstate->use_alternate_io != 0) {
332 			switch (qstate->io_buffer_filter) {
333 			case EVFILT_READ:
334 				io_res = query_socket_read(qstate,
335 					qstate->io_buffer_p,
336 					qstate->io_buffer_watermark);
337 				if (io_res < 0) {
338 					qstate->use_alternate_io = 0;
339 					qstate->process_func = NULL;
340 				} else {
341 					qstate->io_buffer_p += io_res;
342 					if (qstate->io_buffer_p ==
343 					    	qstate->io_buffer +
344 						qstate->io_buffer_size) {
345 						qstate->io_buffer_p =
346 						    qstate->io_buffer;
347 						qstate->use_alternate_io = 0;
348 					}
349 				}
350 			break;
351 			default:
352 			break;
353 			}
354 		}
355 
356 		if (qstate->use_alternate_io == 0) {
357 			do {
358 				res = qstate->process_func(qstate);
359 			} while ((qstate->kevent_watermark == 0) &&
360 					(qstate->process_func != NULL) &&
361 					(res == 0));
362 
363 			if (res != 0)
364 				qstate->process_func = NULL;
365 		}
366 
367 		if ((qstate->use_alternate_io != 0) &&
368 			(qstate->io_buffer_filter == EVFILT_WRITE)) {
369 			io_res = query_socket_write(qstate, qstate->io_buffer_p,
370 				qstate->io_buffer_watermark);
371 			if (io_res < 0) {
372 				qstate->use_alternate_io = 0;
373 				qstate->process_func = NULL;
374 			} else
375 				qstate->io_buffer_p += io_res;
376 		}
377 	} else {
378 		/* assuming that socket was closed */
379 		qstate->process_func = NULL;
380 		qstate->use_alternate_io = 0;
381 	}
382 
383 	if (((qstate->process_func == NULL) &&
384 	    	(qstate->use_alternate_io == 0)) ||
385 		(eof_res != 0) || (res != 0)) {
386 		destroy_query_state(qstate);
387 		close(event_data->ident);
388 		TRACE_OUT(process_socket_event);
389 		return;
390 	}
391 
392 	/* updating the query_state lifetime variable */
393 	get_time_func(&query_timeout);
394 	query_timeout.tv_usec = 0;
395 	query_timeout.tv_sec -= qstate->creation_time.tv_sec;
396 	if (query_timeout.tv_sec > qstate->timeout.tv_sec)
397 		query_timeout.tv_sec = 0;
398 	else
399 		query_timeout.tv_sec = qstate->timeout.tv_sec -
400 			query_timeout.tv_sec;
401 
402 	if ((qstate->use_alternate_io != 0) && (qstate->io_buffer_p ==
403 		qstate->io_buffer + qstate->io_buffer_size))
404 		qstate->use_alternate_io = 0;
405 
406 	if (qstate->use_alternate_io == 0) {
407 		/*
408 		 * If we must send/receive the large block of data,
409 		 * we should prepare the query_state's io_XXX fields.
410 		 * We should also substitute its write_func and read_func
411 		 * with the query_io_buffer_write and query_io_buffer_read,
412 		 * which will allow us to implicitly send/receive this large
413 		 * buffer later (in the subsequent calls to the
414 		 * process_socket_event).
415 		 */
416 		if (qstate->kevent_watermark > MAX_SOCKET_IO_SIZE) {
417 			if (qstate->io_buffer != NULL)
418 				free(qstate->io_buffer);
419 
420 			qstate->io_buffer = (char *)malloc(
421 				qstate->kevent_watermark);
422 			assert(qstate->io_buffer != NULL);
423 			memset(qstate->io_buffer, 0, qstate->kevent_watermark);
424 
425 			qstate->io_buffer_p = qstate->io_buffer;
426 			qstate->io_buffer_size = qstate->kevent_watermark;
427 			qstate->io_buffer_filter = qstate->kevent_filter;
428 
429 			qstate->write_func = query_io_buffer_write;
430 			qstate->read_func = query_io_buffer_read;
431 
432 			if (qstate->kevent_filter == EVFILT_READ)
433 				qstate->use_alternate_io = 1;
434 
435 			qstate->io_buffer_watermark = MAX_SOCKET_IO_SIZE;
436 			EV_SET(&eventlist[1], event_data->ident,
437 				qstate->kevent_filter, EV_ADD | EV_ONESHOT,
438 				NOTE_LOWAT, MAX_SOCKET_IO_SIZE, qstate);
439 		} else {
440 			EV_SET(&eventlist[1], event_data->ident,
441 		    		qstate->kevent_filter, EV_ADD | EV_ONESHOT,
442 		    		NOTE_LOWAT, qstate->kevent_watermark, qstate);
443 		}
444 	} else {
445 		if (qstate->io_buffer + qstate->io_buffer_size -
446 		    	qstate->io_buffer_p <
447 			MAX_SOCKET_IO_SIZE) {
448 			qstate->io_buffer_watermark = qstate->io_buffer +
449 				qstate->io_buffer_size - qstate->io_buffer_p;
450 			EV_SET(&eventlist[1], event_data->ident,
451 			    	qstate->io_buffer_filter,
452 				EV_ADD | EV_ONESHOT, NOTE_LOWAT,
453 				qstate->io_buffer_watermark,
454 				qstate);
455 		} else {
456 			qstate->io_buffer_watermark = MAX_SOCKET_IO_SIZE;
457 			EV_SET(&eventlist[1], event_data->ident,
458 		    		qstate->io_buffer_filter, EV_ADD | EV_ONESHOT,
459 		    		NOTE_LOWAT, MAX_SOCKET_IO_SIZE, qstate);
460 		}
461 	}
462 	EV_SET(&eventlist[0], event_data->ident, EVFILT_TIMER,
463 		EV_ADD | EV_ONESHOT, 0, query_timeout.tv_sec * 1000, qstate);
464 	kevent(env->queue, eventlist, 2, NULL, 0, &kevent_timeout);
465 
466 	TRACE_OUT(process_socket_event);
467 }
468 
469 /*
470  * This routine is called if timer event has been signaled in the kqueue. It
471  * just closes the socket and destroys the query_state.
472  */
473 static void
474 process_timer_event(struct kevent *event_data, struct runtime_env *env,
475 	struct configuration *config)
476 {
477 	struct query_state	*qstate;
478 
479 	TRACE_IN(process_timer_event);
480 	qstate = (struct query_state *)event_data->udata;
481 	destroy_query_state(qstate);
482 	close(event_data->ident);
483 	TRACE_OUT(process_timer_event);
484 }
485 
486 /*
487  * Processing loop is the basic processing routine, that forms a body of each
488  * procssing thread
489  */
490 static void
491 processing_loop(cache the_cache, struct runtime_env *env,
492 	struct configuration *config)
493 {
494 	struct timespec timeout;
495 	const int eventlist_size = 1;
496 	struct kevent eventlist[eventlist_size];
497 	int nevents, i;
498 
499 	TRACE_MSG("=> processing_loop");
500 	memset(&timeout, 0, sizeof(struct timespec));
501 	memset(&eventlist, 0, sizeof(struct kevent) * eventlist_size);
502 
503 	for (;;) {
504 		nevents = kevent(env->queue, NULL, 0, eventlist,
505 	    		eventlist_size, NULL);
506 		/*
507 		 * we can only receive 1 event on success
508 		 */
509 		if (nevents == 1) {
510 			struct kevent *event_data;
511 			event_data = &eventlist[0];
512 
513 			if (event_data->ident == env->sockfd) {
514 				for (i = 0; i < event_data->data; ++i)
515 				    accept_connection(event_data, env, config);
516 
517 				EV_SET(eventlist, s_runtime_env->sockfd,
518 				    EVFILT_READ, EV_ADD | EV_ONESHOT,
519 				    0, 0, 0);
520 				memset(&timeout, 0,
521 				    sizeof(struct timespec));
522 				kevent(s_runtime_env->queue, eventlist,
523 				    1, NULL, 0, &timeout);
524 
525 			} else {
526 				switch (event_data->filter) {
527 				case EVFILT_READ:
528 				case EVFILT_WRITE:
529 					process_socket_event(event_data,
530 						env, config);
531 					break;
532 				case EVFILT_TIMER:
533 					process_timer_event(event_data,
534 						env, config);
535 					break;
536 				default:
537 					break;
538 				}
539 			}
540 		} else {
541 			/* this branch shouldn't be currently executed */
542 		}
543 	}
544 
545 	TRACE_MSG("<= processing_loop");
546 }
547 
548 /*
549  * Wrapper above the processing loop function. It sets the thread signal mask
550  * to avoid SIGPIPE signals (which can happen if the client works incorrectly).
551  */
552 static void *
553 processing_thread(void *data)
554 {
555 	struct processing_thread_args	*args;
556 	sigset_t new;
557 
558 	TRACE_MSG("=> processing_thread");
559 	args = (struct processing_thread_args *)data;
560 
561 	sigemptyset(&new);
562 	sigaddset(&new, SIGPIPE);
563 	if (pthread_sigmask(SIG_BLOCK, &new, NULL) != 0)
564 		LOG_ERR_1("processing thread",
565 			"thread can't block the SIGPIPE signal");
566 
567 	processing_loop(args->the_cache, args->the_runtime_env,
568 		args->the_configuration);
569 	free(args);
570 	TRACE_MSG("<= processing_thread");
571 
572 	return (NULL);
573 }
574 
575 void
576 get_time_func(struct timeval *time)
577 {
578 	struct timespec res;
579 	memset(&res, 0, sizeof(struct timespec));
580 	clock_gettime(CLOCK_MONOTONIC, &res);
581 
582 	time->tv_sec = res.tv_sec;
583 	time->tv_usec = 0;
584 }
585 
586 /*
587  * The idea of _nss_cache_cycle_prevention_function is that nsdispatch will
588  * search for this symbol in the executable. This symbol is the attribute of
589  * the caching daemon. So, if it exists, nsdispatch won't try to connect to
590  * the caching daemon and will just ignore the 'cache' source in the
591  * nsswitch.conf. This method helps to avoid cycles and organize
592  * self-performing requests.
593  */
594 void
595 _nss_cache_cycle_prevention_function(void)
596 {
597 }
598 
599 int
600 main(int argc, char *argv[])
601 {
602 	struct processing_thread_args *thread_args;
603 	pthread_t *threads;
604 
605 	struct pidfh *pidfile;
606 	pid_t pid;
607 
608 	char const *config_file;
609 	char const *error_str;
610 	int error_line;
611 	int i, res;
612 
613 	int trace_mode_enabled;
614 	int force_single_threaded;
615 	int do_not_daemonize;
616 	int clear_user_cache_entries, clear_all_cache_entries;
617 	char *user_config_entry_name, *global_config_entry_name;
618 	int show_statistics;
619 	int daemon_mode, interactive_mode;
620 
621 
622 	/* by default all debug messages are omitted */
623 	TRACE_OFF();
624 
625 	/* startup output */
626 	print_version_info();
627 
628 	/* parsing command line arguments */
629 	trace_mode_enabled = 0;
630 	force_single_threaded = 0;
631 	do_not_daemonize = 0;
632 	clear_user_cache_entries = 0;
633 	clear_all_cache_entries = 0;
634 	show_statistics = 0;
635 	user_config_entry_name = NULL;
636 	global_config_entry_name = NULL;
637 	while ((res = getopt(argc, argv, "nstdi:I:")) != -1) {
638 		switch (res) {
639 		case 'n':
640 			do_not_daemonize = 1;
641 			break;
642 		case 's':
643 			force_single_threaded = 1;
644 			break;
645 		case 't':
646 			trace_mode_enabled = 1;
647 			break;
648 		case 'i':
649 			clear_user_cache_entries = 1;
650 			if (optarg != NULL)
651 				if (strcmp(optarg, "all") != 0)
652 					user_config_entry_name = strdup(optarg);
653 			break;
654 		case 'I':
655 			clear_all_cache_entries = 1;
656 			if (optarg != NULL)
657 				if (strcmp(optarg, "all") != 0)
658 					global_config_entry_name =
659 						strdup(optarg);
660 			break;
661 		case 'd':
662 			show_statistics = 1;
663 			break;
664 		case '?':
665 		default:
666 			usage();
667 			/* NOT REACHED */
668 		}
669 	}
670 
671 	daemon_mode = do_not_daemonize | force_single_threaded |
672 		trace_mode_enabled;
673 	interactive_mode = clear_user_cache_entries | clear_all_cache_entries |
674 		show_statistics;
675 
676 	if ((daemon_mode != 0) && (interactive_mode != 0)) {
677 		LOG_ERR_1("main", "daemon mode and interactive_mode arguments "
678 			"can't be used together");
679 		usage();
680 	}
681 
682 	if (interactive_mode != 0) {
683 		FILE *pidfin = fopen(DEFAULT_PIDFILE_PATH, "r");
684 		char pidbuf[256];
685 
686 		struct nscd_connection_params connection_params;
687 		nscd_connection connection;
688 
689 		int result;
690 
691 		if (pidfin == NULL)
692 			errx(EXIT_FAILURE, "There is no daemon running.");
693 
694 		memset(pidbuf, 0, sizeof(pidbuf));
695 		fread(pidbuf, sizeof(pidbuf) - 1, 1, pidfin);
696 		fclose(pidfin);
697 
698 		if (ferror(pidfin) != 0)
699 			errx(EXIT_FAILURE, "Can't read from pidfile.");
700 
701 		if (sscanf(pidbuf, "%d", &pid) != 1)
702 			errx(EXIT_FAILURE, "Invalid pidfile.");
703 		LOG_MSG_1("main", "daemon PID is %d", pid);
704 
705 
706 		memset(&connection_params, 0,
707 			sizeof(struct nscd_connection_params));
708 		connection_params.socket_path = DEFAULT_SOCKET_PATH;
709 		connection = open_nscd_connection__(&connection_params);
710 		if (connection == INVALID_NSCD_CONNECTION)
711 			errx(EXIT_FAILURE, "Can't connect to the daemon.");
712 
713 		if (clear_user_cache_entries != 0) {
714 			result = nscd_transform__(connection,
715 				user_config_entry_name, TT_USER);
716 			if (result != 0)
717 				LOG_MSG_1("main",
718 					"user cache transformation failed");
719 			else
720 				LOG_MSG_1("main",
721 					"user cache_transformation "
722 					"succeeded");
723 		}
724 
725 		if (clear_all_cache_entries != 0) {
726 			if (geteuid() != 0)
727 				errx(EXIT_FAILURE, "Only root can initiate "
728 					"global cache transformation.");
729 
730 			result = nscd_transform__(connection,
731 				global_config_entry_name, TT_ALL);
732 			if (result != 0)
733 				LOG_MSG_1("main",
734 					"global cache transformation "
735 					"failed");
736 			else
737 				LOG_MSG_1("main",
738 					"global cache transformation "
739 					"succeeded");
740 		}
741 
742 		close_nscd_connection__(connection);
743 
744 		free(user_config_entry_name);
745 		free(global_config_entry_name);
746 		return (EXIT_SUCCESS);
747 	}
748 
749 	pidfile = pidfile_open(DEFAULT_PIDFILE_PATH, 0644, &pid);
750 	if (pidfile == NULL) {
751 		if (errno == EEXIST)
752 			errx(EXIT_FAILURE, "Daemon already running, pid: %d.",
753 				pid);
754 		warn("Cannot open or create pidfile");
755 	}
756 
757 	if (trace_mode_enabled == 1)
758 		TRACE_ON();
759 
760 	/* blocking the main thread from receiving SIGPIPE signal */
761 	sigblock(sigmask(SIGPIPE));
762 
763 	/* daemonization */
764 	if (do_not_daemonize == 0) {
765 		res = daemon(0, trace_mode_enabled == 0 ? 0 : 1);
766 		if (res != 0) {
767 			LOG_ERR_1("main", "can't daemonize myself: %s",
768 		    		strerror(errno));
769 			pidfile_remove(pidfile);
770 			goto fin;
771 		} else
772 			LOG_MSG_1("main", "successfully daemonized");
773 	}
774 
775 	pidfile_write(pidfile);
776 
777 	s_agent_table = init_agent_table();
778 	register_agent(s_agent_table, init_passwd_agent());
779 	register_agent(s_agent_table, init_passwd_mp_agent());
780 	register_agent(s_agent_table, init_group_agent());
781 	register_agent(s_agent_table, init_group_mp_agent());
782 	register_agent(s_agent_table, init_services_agent());
783 	register_agent(s_agent_table, init_services_mp_agent());
784 	LOG_MSG_1("main", "request agents registered successfully");
785 
786 	/*
787  	 * Hosts agent can't work properly until we have access to the
788 	 * appropriate dtab structures, which are used in nsdispatch
789 	 * calls
790 	 *
791 	 register_agent(s_agent_table, init_hosts_agent());
792 	*/
793 
794 	/* configuration initialization */
795 	s_configuration = init_configuration();
796 	fill_configuration_defaults(s_configuration);
797 
798 	error_str = NULL;
799 	error_line = 0;
800 	config_file = CONFIG_PATH;
801 
802 	res = parse_config_file(s_configuration, config_file, &error_str,
803 		&error_line);
804 	if ((res != 0) && (error_str == NULL)) {
805 		config_file = DEFAULT_CONFIG_PATH;
806 		res = parse_config_file(s_configuration, config_file,
807 			&error_str, &error_line);
808 	}
809 
810 	if (res != 0) {
811 		if (error_str != NULL) {
812 		LOG_ERR_1("main", "error in configuration file(%s, %d): %s\n",
813 			config_file, error_line, error_str);
814 		} else {
815 		LOG_ERR_1("main", "no configuration file found "
816 		    	"- was looking for %s and %s",
817 			CONFIG_PATH, DEFAULT_CONFIG_PATH);
818 		}
819 		destroy_configuration(s_configuration);
820 		return (-1);
821 	}
822 
823 	if (force_single_threaded == 1)
824 		s_configuration->threads_num = 1;
825 
826 	/* cache initialization */
827 	s_cache = init_cache_(s_configuration);
828 	if (s_cache == NULL) {
829 		LOG_ERR_1("main", "can't initialize the cache");
830 		destroy_configuration(s_configuration);
831 		return (-1);
832 	}
833 
834 	/* runtime environment initialization */
835 	s_runtime_env = init_runtime_env(s_configuration);
836 	if (s_runtime_env == NULL) {
837 		LOG_ERR_1("main", "can't initialize the runtime environment");
838 		destroy_configuration(s_configuration);
839 		destroy_cache_(s_cache);
840 		return (-1);
841 	}
842 
843 	if (s_configuration->threads_num > 1) {
844 		threads = (pthread_t *)malloc(sizeof(pthread_t) *
845 			s_configuration->threads_num);
846 		memset(threads, 0, sizeof(pthread_t) *
847 	    		s_configuration->threads_num);
848 		for (i = 0; i < s_configuration->threads_num; ++i) {
849 			thread_args = (struct processing_thread_args *)malloc(
850 				sizeof(struct processing_thread_args));
851 			thread_args->the_cache = s_cache;
852 			thread_args->the_runtime_env = s_runtime_env;
853 			thread_args->the_configuration = s_configuration;
854 
855 			LOG_MSG_1("main", "thread #%d was successfully created",
856 				i);
857 			pthread_create(&threads[i], NULL, processing_thread,
858 				thread_args);
859 
860 			thread_args = NULL;
861 		}
862 
863 		for (i = 0; i < s_configuration->threads_num; ++i)
864 			pthread_join(threads[i], NULL);
865 	} else {
866 		LOG_MSG_1("main", "working in single-threaded mode");
867 		processing_loop(s_cache, s_runtime_env, s_configuration);
868 	}
869 
870 fin:
871 	/* runtime environment destruction */
872 	destroy_runtime_env(s_runtime_env);
873 
874 	/* cache destruction */
875 	destroy_cache_(s_cache);
876 
877 	/* configuration destruction */
878 	destroy_configuration(s_configuration);
879 
880 	/* agents table destruction */
881 	destroy_agent_table(s_agent_table);
882 
883 	pidfile_remove(pidfile);
884 	return (EXIT_SUCCESS);
885 }
886