xref: /freebsd/usr.sbin/nscd/nscd.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
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 (qstate->io_buffer != NULL)
409 				free(qstate->io_buffer);
410 
411 			qstate->io_buffer = calloc(1,
412 				qstate->kevent_watermark);
413 			assert(qstate->io_buffer != NULL);
414 
415 			qstate->io_buffer_p = qstate->io_buffer;
416 			qstate->io_buffer_size = qstate->kevent_watermark;
417 			qstate->io_buffer_filter = qstate->kevent_filter;
418 
419 			qstate->write_func = query_io_buffer_write;
420 			qstate->read_func = query_io_buffer_read;
421 
422 			if (qstate->kevent_filter == EVFILT_READ)
423 				qstate->use_alternate_io = 1;
424 
425 			qstate->io_buffer_watermark = MAX_SOCKET_IO_SIZE;
426 			EV_SET(&eventlist[1], event_data->ident,
427 				qstate->kevent_filter, EV_ADD | EV_ONESHOT,
428 				NOTE_LOWAT, MAX_SOCKET_IO_SIZE, qstate);
429 		} else {
430 			EV_SET(&eventlist[1], event_data->ident,
431 		    		qstate->kevent_filter, EV_ADD | EV_ONESHOT,
432 		    		NOTE_LOWAT, qstate->kevent_watermark, qstate);
433 		}
434 	} else {
435 		if (qstate->io_buffer + qstate->io_buffer_size -
436 		    	qstate->io_buffer_p <
437 			MAX_SOCKET_IO_SIZE) {
438 			qstate->io_buffer_watermark = qstate->io_buffer +
439 				qstate->io_buffer_size - qstate->io_buffer_p;
440 			EV_SET(&eventlist[1], event_data->ident,
441 			    	qstate->io_buffer_filter,
442 				EV_ADD | EV_ONESHOT, NOTE_LOWAT,
443 				qstate->io_buffer_watermark,
444 				qstate);
445 		} else {
446 			qstate->io_buffer_watermark = MAX_SOCKET_IO_SIZE;
447 			EV_SET(&eventlist[1], event_data->ident,
448 		    		qstate->io_buffer_filter, EV_ADD | EV_ONESHOT,
449 		    		NOTE_LOWAT, MAX_SOCKET_IO_SIZE, qstate);
450 		}
451 	}
452 	EV_SET(&eventlist[0], event_data->ident, EVFILT_TIMER,
453 		EV_ADD | EV_ONESHOT, 0, query_timeout.tv_sec * 1000, qstate);
454 	kevent(env->queue, eventlist, 2, NULL, 0, &kevent_timeout);
455 
456 	TRACE_OUT(process_socket_event);
457 }
458 
459 /*
460  * This routine is called if timer event has been signaled in the kqueue. It
461  * just closes the socket and destroys the query_state.
462  */
463 static void
464 process_timer_event(struct kevent *event_data, struct runtime_env *env,
465 	struct configuration *config)
466 {
467 	struct query_state	*qstate;
468 
469 	TRACE_IN(process_timer_event);
470 	qstate = (struct query_state *)event_data->udata;
471 	destroy_query_state(qstate);
472 	close(event_data->ident);
473 	TRACE_OUT(process_timer_event);
474 }
475 
476 /*
477  * Processing loop is the basic processing routine, that forms a body of each
478  * procssing thread
479  */
480 static void
481 processing_loop(cache the_cache, struct runtime_env *env,
482 	struct configuration *config)
483 {
484 	struct timespec timeout;
485 	const int eventlist_size = 1;
486 	struct kevent eventlist[eventlist_size];
487 	int nevents, i;
488 
489 	TRACE_MSG("=> processing_loop");
490 	memset(&timeout, 0, sizeof(struct timespec));
491 	memset(&eventlist, 0, sizeof(struct kevent) * eventlist_size);
492 
493 	for (;;) {
494 		nevents = kevent(env->queue, NULL, 0, eventlist,
495 	    		eventlist_size, NULL);
496 		/*
497 		 * we can only receive 1 event on success
498 		 */
499 		if (nevents == 1) {
500 			struct kevent *event_data;
501 			event_data = &eventlist[0];
502 
503 			if ((int)event_data->ident == env->sockfd) {
504 				for (i = 0; i < event_data->data; ++i)
505 				    accept_connection(event_data, env, config);
506 
507 				EV_SET(eventlist, s_runtime_env->sockfd,
508 				    EVFILT_READ, EV_ADD | EV_ONESHOT,
509 				    0, 0, 0);
510 				memset(&timeout, 0,
511 				    sizeof(struct timespec));
512 				kevent(s_runtime_env->queue, eventlist,
513 				    1, NULL, 0, &timeout);
514 
515 			} else {
516 				switch (event_data->filter) {
517 				case EVFILT_READ:
518 				case EVFILT_WRITE:
519 					process_socket_event(event_data,
520 						env, config);
521 					break;
522 				case EVFILT_TIMER:
523 					process_timer_event(event_data,
524 						env, config);
525 					break;
526 				default:
527 					break;
528 				}
529 			}
530 		} else {
531 			/* this branch shouldn't be currently executed */
532 		}
533 	}
534 
535 	TRACE_MSG("<= processing_loop");
536 }
537 
538 /*
539  * Wrapper above the processing loop function. It sets the thread signal mask
540  * to avoid SIGPIPE signals (which can happen if the client works incorrectly).
541  */
542 static void *
543 processing_thread(void *data)
544 {
545 	struct processing_thread_args	*args;
546 	sigset_t new;
547 
548 	TRACE_MSG("=> processing_thread");
549 	args = (struct processing_thread_args *)data;
550 
551 	sigemptyset(&new);
552 	sigaddset(&new, SIGPIPE);
553 	if (pthread_sigmask(SIG_BLOCK, &new, NULL) != 0)
554 		LOG_ERR_1("processing thread",
555 			"thread can't block the SIGPIPE signal");
556 
557 	processing_loop(args->the_cache, args->the_runtime_env,
558 		args->the_configuration);
559 	free(args);
560 	TRACE_MSG("<= processing_thread");
561 
562 	return (NULL);
563 }
564 
565 void
566 get_time_func(struct timeval *time)
567 {
568 	struct timespec res;
569 	memset(&res, 0, sizeof(struct timespec));
570 	clock_gettime(CLOCK_MONOTONIC, &res);
571 
572 	time->tv_sec = res.tv_sec;
573 	time->tv_usec = 0;
574 }
575 
576 /*
577  * The idea of _nss_cache_cycle_prevention_function is that nsdispatch
578  * will search for this symbol in the executable. This symbol is the
579  * attribute of the caching daemon. So, if it exists, nsdispatch won't try
580  * to connect to the caching daemon and will just ignore the 'cache'
581  * source in the nsswitch.conf. This method helps to avoid cycles and
582  * organize self-performing requests.
583  *
584  * (not actually a function; it used to be, but it doesn't make any
585  * difference, as long as it has external linkage)
586  */
587 void *_nss_cache_cycle_prevention_function;
588 
589 int
590 main(int argc, char *argv[])
591 {
592 	struct processing_thread_args *thread_args;
593 	pthread_t *threads;
594 
595 	struct pidfh *pidfile;
596 	pid_t pid;
597 
598 	char const *config_file;
599 	char const *error_str;
600 	int error_line;
601 	int i, res;
602 
603 	int trace_mode_enabled;
604 	int force_single_threaded;
605 	int do_not_daemonize;
606 	int clear_user_cache_entries, clear_all_cache_entries;
607 	char *user_config_entry_name, *global_config_entry_name;
608 	int show_statistics;
609 	int daemon_mode, interactive_mode;
610 
611 
612 	/* by default all debug messages are omitted */
613 	TRACE_OFF();
614 
615 	/* parsing command line arguments */
616 	trace_mode_enabled = 0;
617 	force_single_threaded = 0;
618 	do_not_daemonize = 0;
619 	clear_user_cache_entries = 0;
620 	clear_all_cache_entries = 0;
621 	show_statistics = 0;
622 	user_config_entry_name = NULL;
623 	global_config_entry_name = NULL;
624 	while ((res = getopt(argc, argv, "nstdi:I:")) != -1) {
625 		switch (res) {
626 		case 'n':
627 			do_not_daemonize = 1;
628 			break;
629 		case 's':
630 			force_single_threaded = 1;
631 			break;
632 		case 't':
633 			trace_mode_enabled = 1;
634 			break;
635 		case 'i':
636 			clear_user_cache_entries = 1;
637 			if (optarg != NULL)
638 				if (strcmp(optarg, "all") != 0)
639 					user_config_entry_name = strdup(optarg);
640 			break;
641 		case 'I':
642 			clear_all_cache_entries = 1;
643 			if (optarg != NULL)
644 				if (strcmp(optarg, "all") != 0)
645 					global_config_entry_name =
646 						strdup(optarg);
647 			break;
648 		case 'd':
649 			show_statistics = 1;
650 			break;
651 		case '?':
652 		default:
653 			usage();
654 			/* NOT REACHED */
655 		}
656 	}
657 
658 	daemon_mode = do_not_daemonize | force_single_threaded |
659 		trace_mode_enabled;
660 	interactive_mode = clear_user_cache_entries | clear_all_cache_entries |
661 		show_statistics;
662 
663 	if ((daemon_mode != 0) && (interactive_mode != 0)) {
664 		LOG_ERR_1("main", "daemon mode and interactive_mode arguments "
665 			"can't be used together");
666 		usage();
667 	}
668 
669 	if (interactive_mode != 0) {
670 		FILE *pidfin = fopen(DEFAULT_PIDFILE_PATH, "r");
671 		char pidbuf[256];
672 
673 		struct nscd_connection_params connection_params;
674 		nscd_connection connection;
675 
676 		int result;
677 
678 		if (pidfin == NULL)
679 			errx(EXIT_FAILURE, "There is no daemon running.");
680 
681 		memset(pidbuf, 0, sizeof(pidbuf));
682 		fread(pidbuf, sizeof(pidbuf) - 1, 1, pidfin);
683 		fclose(pidfin);
684 
685 		if (ferror(pidfin) != 0)
686 			errx(EXIT_FAILURE, "Can't read from pidfile.");
687 
688 		if (sscanf(pidbuf, "%d", &pid) != 1)
689 			errx(EXIT_FAILURE, "Invalid pidfile.");
690 		LOG_MSG_1("main", "daemon PID is %d", pid);
691 
692 
693 		memset(&connection_params, 0,
694 			sizeof(struct nscd_connection_params));
695 		connection_params.socket_path = DEFAULT_SOCKET_PATH;
696 		connection = open_nscd_connection__(&connection_params);
697 		if (connection == INVALID_NSCD_CONNECTION)
698 			errx(EXIT_FAILURE, "Can't connect to the daemon.");
699 
700 		if (clear_user_cache_entries != 0) {
701 			result = nscd_transform__(connection,
702 				user_config_entry_name, TT_USER);
703 			if (result != 0)
704 				LOG_MSG_1("main",
705 					"user cache transformation failed");
706 			else
707 				LOG_MSG_1("main",
708 					"user cache_transformation "
709 					"succeeded");
710 		}
711 
712 		if (clear_all_cache_entries != 0) {
713 			if (geteuid() != 0)
714 				errx(EXIT_FAILURE, "Only root can initiate "
715 					"global cache transformation.");
716 
717 			result = nscd_transform__(connection,
718 				global_config_entry_name, TT_ALL);
719 			if (result != 0)
720 				LOG_MSG_1("main",
721 					"global cache transformation "
722 					"failed");
723 			else
724 				LOG_MSG_1("main",
725 					"global cache transformation "
726 					"succeeded");
727 		}
728 
729 		close_nscd_connection__(connection);
730 
731 		free(user_config_entry_name);
732 		free(global_config_entry_name);
733 		return (EXIT_SUCCESS);
734 	}
735 
736 	pidfile = pidfile_open(DEFAULT_PIDFILE_PATH, 0644, &pid);
737 	if (pidfile == NULL) {
738 		if (errno == EEXIST)
739 			errx(EXIT_FAILURE, "Daemon already running, pid: %d.",
740 				pid);
741 		warn("Cannot open or create pidfile");
742 	}
743 
744 	if (trace_mode_enabled == 1)
745 		TRACE_ON();
746 
747 	/* blocking the main thread from receiving SIGPIPE signal */
748 	sigblock(sigmask(SIGPIPE));
749 
750 	/* daemonization */
751 	if (do_not_daemonize == 0) {
752 		res = daemon(0, trace_mode_enabled == 0 ? 0 : 1);
753 		if (res != 0) {
754 			LOG_ERR_1("main", "can't daemonize myself: %s",
755 		    		strerror(errno));
756 			pidfile_remove(pidfile);
757 			goto fin;
758 		} else
759 			LOG_MSG_1("main", "successfully daemonized");
760 	}
761 
762 	pidfile_write(pidfile);
763 
764 	s_agent_table = init_agent_table();
765 	register_agent(s_agent_table, init_passwd_agent());
766 	register_agent(s_agent_table, init_passwd_mp_agent());
767 	register_agent(s_agent_table, init_group_agent());
768 	register_agent(s_agent_table, init_group_mp_agent());
769 	register_agent(s_agent_table, init_services_agent());
770 	register_agent(s_agent_table, init_services_mp_agent());
771 	LOG_MSG_1("main", "request agents registered successfully");
772 
773 	/*
774  	 * Hosts agent can't work properly until we have access to the
775 	 * appropriate dtab structures, which are used in nsdispatch
776 	 * calls
777 	 *
778 	 register_agent(s_agent_table, init_hosts_agent());
779 	*/
780 
781 	/* configuration initialization */
782 	s_configuration = init_configuration();
783 	fill_configuration_defaults(s_configuration);
784 
785 	error_str = NULL;
786 	error_line = 0;
787 	config_file = CONFIG_PATH;
788 
789 	res = parse_config_file(s_configuration, config_file, &error_str,
790 		&error_line);
791 	if ((res != 0) && (error_str == NULL)) {
792 		config_file = DEFAULT_CONFIG_PATH;
793 		res = parse_config_file(s_configuration, config_file,
794 			&error_str, &error_line);
795 	}
796 
797 	if (res != 0) {
798 		if (error_str != NULL) {
799 		LOG_ERR_1("main", "error in configuration file(%s, %d): %s\n",
800 			config_file, error_line, error_str);
801 		} else {
802 		LOG_ERR_1("main", "no configuration file found "
803 		    	"- was looking for %s and %s",
804 			CONFIG_PATH, DEFAULT_CONFIG_PATH);
805 		}
806 		destroy_configuration(s_configuration);
807 		return (-1);
808 	}
809 
810 	if (force_single_threaded == 1)
811 		s_configuration->threads_num = 1;
812 
813 	/* cache initialization */
814 	s_cache = init_cache_(s_configuration);
815 	if (s_cache == NULL) {
816 		LOG_ERR_1("main", "can't initialize the cache");
817 		destroy_configuration(s_configuration);
818 		return (-1);
819 	}
820 
821 	/* runtime environment initialization */
822 	s_runtime_env = init_runtime_env(s_configuration);
823 	if (s_runtime_env == NULL) {
824 		LOG_ERR_1("main", "can't initialize the runtime environment");
825 		destroy_configuration(s_configuration);
826 		destroy_cache_(s_cache);
827 		return (-1);
828 	}
829 
830 	if (s_configuration->threads_num > 1) {
831 		threads = calloc(s_configuration->threads_num,
832 			sizeof(*threads));
833 		for (i = 0; i < s_configuration->threads_num; ++i) {
834 			thread_args = malloc(
835 				sizeof(*thread_args));
836 			thread_args->the_cache = s_cache;
837 			thread_args->the_runtime_env = s_runtime_env;
838 			thread_args->the_configuration = s_configuration;
839 
840 			LOG_MSG_1("main", "thread #%d was successfully created",
841 				i);
842 			pthread_create(&threads[i], NULL, processing_thread,
843 				thread_args);
844 
845 			thread_args = NULL;
846 		}
847 
848 		for (i = 0; i < s_configuration->threads_num; ++i)
849 			pthread_join(threads[i], NULL);
850 	} else {
851 		LOG_MSG_1("main", "working in single-threaded mode");
852 		processing_loop(s_cache, s_runtime_env, s_configuration);
853 	}
854 
855 fin:
856 	/* runtime environment destruction */
857 	destroy_runtime_env(s_runtime_env);
858 
859 	/* cache destruction */
860 	destroy_cache_(s_cache);
861 
862 	/* configuration destruction */
863 	destroy_configuration(s_configuration);
864 
865 	/* agents table destruction */
866 	destroy_agent_table(s_agent_table);
867 
868 	pidfile_remove(pidfile);
869 	return (EXIT_SUCCESS);
870 }
871