xref: /freebsd/usr.sbin/nscd/nscd.c (revision d056fa046c6a91b90cd98165face0e42a33a5173)
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 "cachedcli.h"
53 #include "cachelib.h"
54 #include "config.h"
55 #include "debug.h"
56 #include "log.h"
57 #include "parser.h"
58 #include "query.h"
59 #include "singletons.h"
60 
61 #ifndef CONFIG_PATH
62 #define CONFIG_PATH "/etc/cached.conf"
63 #endif
64 #define DEFAULT_CONFIG_PATH	"cached.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("cached 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,"usage: cached [-nstiId]\n");
104 	exit(1);
105 }
106 
107 static cache
108 init_cache_(struct configuration *config)
109 {
110 	struct cache_params params;
111 	cache retval;
112 
113 	struct configuration_entry *config_entry;
114 	size_t	size, i;
115 	int res;
116 
117 	TRACE_IN(init_cache_);
118 
119 	memset(&params, 0, sizeof(struct cache_params));
120 	params.get_time_func = get_time_func;
121 	retval = init_cache(&params);
122 
123 	size = configuration_get_entries_size(config);
124 	for (i = 0; i < size; ++i) {
125 		config_entry = configuration_get_entry(config, i);
126 	    	/*
127 	    	 * We should register common entries now - multipart entries
128 	    	 * would be registered automatically during the queries.
129 	    	 */
130 		res = register_cache_entry(retval, (struct cache_entry_params *)
131 			&config_entry->positive_cache_params);
132 		config_entry->positive_cache_entry = find_cache_entry(retval,
133 			config_entry->positive_cache_params.entry_name);
134 		assert(config_entry->positive_cache_entry !=
135 			INVALID_CACHE_ENTRY);
136 
137 		res = register_cache_entry(retval, (struct cache_entry_params *)
138 			&config_entry->negative_cache_params);
139 		config_entry->negative_cache_entry = find_cache_entry(retval,
140 			config_entry->negative_cache_params.entry_name);
141 		assert(config_entry->negative_cache_entry !=
142 			INVALID_CACHE_ENTRY);
143 	}
144 
145 	LOG_MSG_2("cache", "cache was successfully initialized");
146 	TRACE_OUT(init_cache_);
147 	return (retval);
148 }
149 
150 static void
151 destroy_cache_(cache the_cache)
152 {
153 	TRACE_IN(destroy_cache_);
154 	destroy_cache(the_cache);
155 	TRACE_OUT(destroy_cache_);
156 }
157 
158 /*
159  * Socket and kqueues are prepared here. We have one global queue for both
160  * socket and timers events.
161  */
162 static struct runtime_env *
163 init_runtime_env(struct configuration *config)
164 {
165 	int serv_addr_len;
166 	struct sockaddr_un serv_addr;
167 
168 	struct kevent eventlist;
169 	struct timespec timeout;
170 
171 	struct runtime_env *retval;
172 
173 	TRACE_IN(init_runtime_env);
174 	retval = (struct runtime_env *)malloc(sizeof(struct runtime_env));
175 	assert(retval != NULL);
176 	memset(retval, 0, sizeof(struct runtime_env));
177 
178 	retval->sockfd = socket(PF_LOCAL, SOCK_STREAM, 0);
179 
180 	if (config->force_unlink == 1)
181 		unlink(config->socket_path);
182 
183 	memset(&serv_addr, 0, sizeof(struct sockaddr_un));
184 	serv_addr.sun_family = PF_LOCAL;
185 	strncpy(serv_addr.sun_path, config->socket_path,
186 		sizeof(serv_addr.sun_path));
187 	serv_addr_len = sizeof(serv_addr.sun_family) +
188 		strlen(serv_addr.sun_path) + 1;
189 
190 	if (bind(retval->sockfd, (struct sockaddr *)&serv_addr,
191 		serv_addr_len) == -1) {
192 		close(retval->sockfd);
193 		free(retval);
194 
195 		LOG_ERR_2("runtime environment", "can't bind socket to path: "
196 			"%s", config->socket_path);
197 		TRACE_OUT(init_runtime_env);
198 		return (NULL);
199 	}
200 	LOG_MSG_2("runtime environment", "using socket %s",
201 		config->socket_path);
202 
203 	/*
204 	 * Here we're marking socket as non-blocking and setting its backlog
205 	 * to the maximum value
206 	 */
207 	chmod(config->socket_path, config->socket_mode);
208 	listen(retval->sockfd, -1);
209 	fcntl(retval->sockfd, F_SETFL, O_NONBLOCK);
210 
211 	retval->queue = kqueue();
212 	assert(retval->queue != -1);
213 
214 	EV_SET(&eventlist, retval->sockfd, EVFILT_READ, EV_ADD | EV_ONESHOT,
215 		0, 0, 0);
216 	memset(&timeout, 0, sizeof(struct timespec));
217 	kevent(retval->queue, &eventlist, 1, NULL, 0, &timeout);
218 
219 	LOG_MSG_2("runtime environment", "successfully initialized");
220 	TRACE_OUT(init_runtime_env);
221 	return (retval);
222 }
223 
224 static void
225 destroy_runtime_env(struct runtime_env *env)
226 {
227 	TRACE_IN(destroy_runtime_env);
228 	close(env->queue);
229 	close(env->sockfd);
230 	free(env);
231 	TRACE_OUT(destroy_runtime_env);
232 }
233 
234 static void
235 accept_connection(struct kevent *event_data, struct runtime_env *env,
236 	struct configuration *config)
237 {
238 	struct kevent	eventlist[2];
239 	struct timespec	timeout;
240 	struct query_state	*qstate;
241 
242 	int	fd;
243 	int	res;
244 
245 	uid_t	euid;
246 	gid_t	egid;
247 
248 	TRACE_IN(accept_connection);
249 	fd = accept(event_data->ident, NULL, NULL);
250 	if (fd == -1) {
251 		LOG_ERR_2("accept_connection", "error %d during accept()",
252 		    errno);
253 		TRACE_OUT(accept_connection);
254 		return;
255 	}
256 
257 	if (getpeereid(fd, &euid, &egid) != 0) {
258 		LOG_ERR_2("accept_connection", "error %d during getpeereid()",
259 			errno);
260 		TRACE_OUT(accept_connection);
261 		return;
262 	}
263 
264 	qstate = init_query_state(fd, sizeof(int), euid, egid);
265 	if (qstate == NULL) {
266 		LOG_ERR_2("accept_connection", "can't init query_state");
267 		TRACE_OUT(accept_connection);
268 		return;
269 	}
270 
271 	memset(&timeout, 0, sizeof(struct timespec));
272 	EV_SET(&eventlist[0], fd, EVFILT_TIMER, EV_ADD | EV_ONESHOT,
273 		0, qstate->timeout.tv_sec * 1000, qstate);
274 	EV_SET(&eventlist[1], fd, EVFILT_READ, EV_ADD | EV_ONESHOT,
275 		NOTE_LOWAT, qstate->kevent_watermark, qstate);
276 	res = kevent(env->queue, eventlist, 2, NULL, 0, &timeout);
277 	if (res < 0)
278 		LOG_ERR_2("accept_connection", "kevent error");
279 
280 	TRACE_OUT(accept_connection);
281 }
282 
283 static void
284 process_socket_event(struct kevent *event_data, struct runtime_env *env,
285 	struct configuration *config)
286 {
287 	struct kevent	eventlist[2];
288 	struct timeval	query_timeout;
289 	struct timespec	kevent_timeout;
290 	int	nevents;
291 	int	eof_res, res;
292 	ssize_t	io_res;
293 	struct query_state *qstate;
294 
295 	TRACE_IN(process_socket_event);
296 	eof_res = event_data->flags & EV_EOF ? 1 : 0;
297 	res = 0;
298 
299 	memset(&kevent_timeout, 0, sizeof(struct timespec));
300 	EV_SET(&eventlist[0], event_data->ident, EVFILT_TIMER, EV_DELETE,
301 		0, 0, NULL);
302 	nevents = kevent(env->queue, eventlist, 1, NULL, 0, &kevent_timeout);
303 	if (nevents == -1) {
304 		if (errno == ENOENT) {
305 			/* the timer is already handling this event */
306 			TRACE_OUT(process_socket_event);
307 			return;
308 		} else {
309 			/* some other error happened */
310 			LOG_ERR_2("process_socket_event", "kevent error, errno"
311 				" is %d", errno);
312 			TRACE_OUT(process_socket_event);
313 			return;
314 		}
315 	}
316 	qstate = (struct query_state *)event_data->udata;
317 
318 	/*
319 	 * If the buffer that is to be send/received is too large,
320 	 * we send it implicitly, by using query_io_buffer_read and
321 	 * query_io_buffer_write functions in the query_state. These functions
322 	 * use the temporary buffer, which is later send/received in parts.
323 	 * The code below implements buffer splitting/mergind for send/receive
324 	 * operations. It also does the actual socket IO operations.
325 	 */
326 	if (((qstate->use_alternate_io == 0) &&
327 		(qstate->kevent_watermark <= event_data->data)) ||
328 		((qstate->use_alternate_io != 0) &&
329 		(qstate->io_buffer_watermark <= event_data->data))) {
330 		if (qstate->use_alternate_io != 0) {
331 			switch (qstate->io_buffer_filter) {
332 			case EVFILT_READ:
333 				io_res = query_socket_read(qstate,
334 					qstate->io_buffer_p,
335 					qstate->io_buffer_watermark);
336 				if (io_res < 0) {
337 					qstate->use_alternate_io = 0;
338 					qstate->process_func = NULL;
339 				} else {
340 					qstate->io_buffer_p += io_res;
341 					if (qstate->io_buffer_p ==
342 					    	qstate->io_buffer +
343 						qstate->io_buffer_size) {
344 						qstate->io_buffer_p =
345 						    qstate->io_buffer;
346 						qstate->use_alternate_io = 0;
347 					}
348 				}
349 			break;
350 			default:
351 			break;
352 			}
353 		}
354 
355 		if (qstate->use_alternate_io == 0) {
356 			do {
357 				res = qstate->process_func(qstate);
358 			} while ((qstate->kevent_watermark == 0) &&
359 					(qstate->process_func != NULL) &&
360 					(res == 0));
361 
362 			if (res != 0)
363 				qstate->process_func = NULL;
364 		}
365 
366 		if ((qstate->use_alternate_io != 0) &&
367 			(qstate->io_buffer_filter == EVFILT_WRITE)) {
368 			io_res = query_socket_write(qstate, qstate->io_buffer_p,
369 				qstate->io_buffer_watermark);
370 			if (io_res < 0) {
371 				qstate->use_alternate_io = 0;
372 				qstate->process_func = NULL;
373 			} else
374 				qstate->io_buffer_p += io_res;
375 		}
376 	} else {
377 		/* assuming that socket was closed */
378 		qstate->process_func = NULL;
379 		qstate->use_alternate_io = 0;
380 	}
381 
382 	if (((qstate->process_func == NULL) &&
383 	    	(qstate->use_alternate_io == 0)) ||
384 		(eof_res != 0) || (res != 0)) {
385 		destroy_query_state(qstate);
386 		close(event_data->ident);
387 		TRACE_OUT(process_socket_event);
388 		return;
389 	}
390 
391 	/* updating the query_state lifetime variable */
392 	get_time_func(&query_timeout);
393 	query_timeout.tv_usec = 0;
394 	query_timeout.tv_sec -= qstate->creation_time.tv_sec;
395 	if (query_timeout.tv_sec > qstate->timeout.tv_sec)
396 		query_timeout.tv_sec = 0;
397 	else
398 		query_timeout.tv_sec = qstate->timeout.tv_sec -
399 			query_timeout.tv_sec;
400 
401 	if ((qstate->use_alternate_io != 0) && (qstate->io_buffer_p ==
402 		qstate->io_buffer + qstate->io_buffer_size))
403 		qstate->use_alternate_io = 0;
404 
405 	if (qstate->use_alternate_io == 0) {
406 		/*
407 		 * If we must send/receive the large block of data,
408 		 * we should prepare the query_state's io_XXX fields.
409 		 * We should also substitute its write_func and read_func
410 		 * with the query_io_buffer_write and query_io_buffer_read,
411 		 * which will allow us to implicitly send/receive this large
412 		 * buffer later (in the subsequent calls to the
413 		 * process_socket_event).
414 		 */
415 		if (qstate->kevent_watermark > MAX_SOCKET_IO_SIZE) {
416 			if (qstate->io_buffer != NULL)
417 				free(qstate->io_buffer);
418 
419 			qstate->io_buffer = (char *)malloc(
420 				qstate->kevent_watermark);
421 			assert(qstate->io_buffer != NULL);
422 			memset(qstate->io_buffer, 0, qstate->kevent_watermark);
423 
424 			qstate->io_buffer_p = qstate->io_buffer;
425 			qstate->io_buffer_size = qstate->kevent_watermark;
426 			qstate->io_buffer_filter = qstate->kevent_filter;
427 
428 			qstate->write_func = query_io_buffer_write;
429 			qstate->read_func = query_io_buffer_read;
430 
431 			if (qstate->kevent_filter == EVFILT_READ)
432 				qstate->use_alternate_io = 1;
433 
434 			qstate->io_buffer_watermark = MAX_SOCKET_IO_SIZE;
435 			EV_SET(&eventlist[1], event_data->ident,
436 				qstate->kevent_filter, EV_ADD | EV_ONESHOT,
437 				NOTE_LOWAT, MAX_SOCKET_IO_SIZE, qstate);
438 		} else {
439 			EV_SET(&eventlist[1], event_data->ident,
440 		    		qstate->kevent_filter, EV_ADD | EV_ONESHOT,
441 		    		NOTE_LOWAT, qstate->kevent_watermark, qstate);
442 		}
443 	} else {
444 		if (qstate->io_buffer + qstate->io_buffer_size -
445 		    	qstate->io_buffer_p <
446 			MAX_SOCKET_IO_SIZE) {
447 			qstate->io_buffer_watermark = qstate->io_buffer +
448 				qstate->io_buffer_size - qstate->io_buffer_p;
449 			EV_SET(&eventlist[1], event_data->ident,
450 			    	qstate->io_buffer_filter,
451 				EV_ADD | EV_ONESHOT, NOTE_LOWAT,
452 				qstate->io_buffer_watermark,
453 				qstate);
454 		} else {
455 			qstate->io_buffer_watermark = MAX_SOCKET_IO_SIZE;
456 			EV_SET(&eventlist[1], event_data->ident,
457 		    		qstate->io_buffer_filter, EV_ADD | EV_ONESHOT,
458 		    		NOTE_LOWAT, MAX_SOCKET_IO_SIZE, qstate);
459 		}
460 	}
461 	EV_SET(&eventlist[0], event_data->ident, EVFILT_TIMER,
462 		EV_ADD | EV_ONESHOT, 0, query_timeout.tv_sec * 1000, qstate);
463 	kevent(env->queue, eventlist, 2, NULL, 0, &kevent_timeout);
464 
465 	TRACE_OUT(process_socket_event);
466 }
467 
468 /*
469  * This routine is called if timer event has been signaled in the kqueue. It
470  * just closes the socket and destroys the query_state.
471  */
472 static void
473 process_timer_event(struct kevent *event_data, struct runtime_env *env,
474 	struct configuration *config)
475 {
476 	struct query_state	*qstate;
477 
478 	TRACE_IN(process_timer_event);
479 	qstate = (struct query_state *)event_data->udata;
480 	destroy_query_state(qstate);
481 	close(event_data->ident);
482 	TRACE_OUT(process_timer_event);
483 }
484 
485 /*
486  * Processing loop is the basic processing routine, that forms a body of each
487  * procssing thread
488  */
489 static void
490 processing_loop(cache the_cache, struct runtime_env *env,
491 	struct configuration *config)
492 {
493 	struct timespec timeout;
494 	const int eventlist_size = 1;
495 	struct kevent eventlist[eventlist_size];
496 	int nevents, i;
497 
498 	TRACE_MSG("=> processing_loop");
499 	memset(&timeout, 0, sizeof(struct timespec));
500 	memset(&eventlist, 0, sizeof(struct kevent) * eventlist_size);
501 
502 	for (;;) {
503 		nevents = kevent(env->queue, NULL, 0, eventlist,
504 	    		eventlist_size, NULL);
505 		/*
506 		 * we can only receive 1 event on success
507 		 */
508 		if (nevents == 1) {
509 			struct kevent *event_data;
510 			event_data = &eventlist[0];
511 
512 			if (event_data->ident == env->sockfd) {
513 				for (i = 0; i < event_data->data; ++i)
514 				    accept_connection(event_data, env, config);
515 
516 				EV_SET(eventlist, s_runtime_env->sockfd,
517 				    EVFILT_READ, EV_ADD | EV_ONESHOT,
518 				    0, 0, 0);
519 				memset(&timeout, 0,
520 				    sizeof(struct timespec));
521 				kevent(s_runtime_env->queue, eventlist,
522 				    1, NULL, 0, &timeout);
523 
524 			} else {
525 				switch (event_data->filter) {
526 				case EVFILT_READ:
527 				case EVFILT_WRITE:
528 					process_socket_event(event_data,
529 						env, config);
530 					break;
531 				case EVFILT_TIMER:
532 					process_timer_event(event_data,
533 						env, config);
534 					break;
535 				default:
536 					break;
537 				}
538 			}
539 		} else {
540 			/* this branch shouldn't be currently executed */
541 		}
542 	}
543 
544 	TRACE_MSG("<= processing_loop");
545 }
546 
547 /*
548  * Wrapper above the processing loop function. It sets the thread signal mask
549  * to avoid SIGPIPE signals (which can happen if the client works incorrectly).
550  */
551 static void *
552 processing_thread(void *data)
553 {
554 	struct processing_thread_args	*args;
555 	sigset_t new;
556 
557 	TRACE_MSG("=> processing_thread");
558 	args = (struct processing_thread_args *)data;
559 
560 	sigemptyset(&new);
561 	sigaddset(&new, SIGPIPE);
562 	if (pthread_sigmask(SIG_BLOCK, &new, NULL) != 0)
563 		LOG_ERR_1("processing thread",
564 			"thread can't block the SIGPIPE signal");
565 
566 	processing_loop(args->the_cache, args->the_runtime_env,
567 		args->the_configuration);
568 	free(args);
569 	TRACE_MSG("<= processing_thread");
570 
571 	return (NULL);
572 }
573 
574 void
575 get_time_func(struct timeval *time)
576 {
577 	struct timespec res;
578 	memset(&res, 0, sizeof(struct timespec));
579 	clock_gettime(CLOCK_MONOTONIC, &res);
580 
581 	time->tv_sec = res.tv_sec;
582 	time->tv_usec = 0;
583 }
584 
585 /*
586  * The idea of _nss_cache_cycle_prevention_function is that nsdispatch will
587  * search for this symbol in the executable. This symbol is the attribute of
588  * the caching daemon. So, if it exists, nsdispatch won't try to connect to
589  * the caching daemon and will just ignore the 'cache' source in the
590  * nsswitch.conf. This method helps to avoid cycles and organize
591  * self-performing requests.
592  */
593 void
594 _nss_cache_cycle_prevention_function(void)
595 {
596 }
597 
598 int
599 main(int argc, char *argv[])
600 {
601 	struct processing_thread_args *thread_args;
602 	pthread_t *threads;
603 
604 	struct pidfh *pidfile;
605 	pid_t pid;
606 
607 	char const *config_file;
608 	char const *error_str;
609 	int error_line;
610 	int i, res;
611 
612 	int trace_mode_enabled;
613 	int force_single_threaded;
614 	int do_not_daemonize;
615 	int clear_user_cache_entries, clear_all_cache_entries;
616 	char *user_config_entry_name, *global_config_entry_name;
617 	int show_statistics;
618 	int daemon_mode, interactive_mode;
619 
620 
621 	/* by default all debug messages are omitted */
622 	TRACE_OFF();
623 
624 	/* startup output */
625 	print_version_info();
626 
627 	/* parsing command line arguments */
628 	trace_mode_enabled = 0;
629 	force_single_threaded = 0;
630 	do_not_daemonize = 0;
631 	clear_user_cache_entries = 0;
632 	clear_all_cache_entries = 0;
633 	show_statistics = 0;
634 	user_config_entry_name = NULL;
635 	global_config_entry_name = NULL;
636 	while ((res = getopt(argc, argv, "nstdi:I:")) != -1) {
637 		switch (res) {
638 		case 'n':
639 			do_not_daemonize = 1;
640 			break;
641 		case 's':
642 			force_single_threaded = 1;
643 			break;
644 		case 't':
645 			trace_mode_enabled = 1;
646 			break;
647 		case 'i':
648 			clear_user_cache_entries = 1;
649 			if (optarg != NULL)
650 				if (strcmp(optarg, "all") != 0)
651 					user_config_entry_name = strdup(optarg);
652 			break;
653 		case 'I':
654 			clear_all_cache_entries = 1;
655 			if (optarg != NULL)
656 				if (strcmp(optarg, "all") != 0)
657 					global_config_entry_name =
658 						strdup(optarg);
659 			break;
660 		case 'd':
661 			show_statistics = 1;
662 			break;
663 		case '?':
664 		default:
665 			usage();
666 			/* NOT REACHED */
667 		}
668 	}
669 
670 	daemon_mode = do_not_daemonize | force_single_threaded |
671 		trace_mode_enabled;
672 	interactive_mode = clear_user_cache_entries | clear_all_cache_entries |
673 		show_statistics;
674 
675 	if ((daemon_mode != 0) && (interactive_mode != 0)) {
676 		LOG_ERR_1("main", "daemon mode and interactive_mode arguments "
677 			"can't be used together");
678 		usage();
679 	}
680 
681 	if (interactive_mode != 0) {
682 		FILE *pidfin = fopen(DEFAULT_PIDFILE_PATH, "r");
683 		char pidbuf[256];
684 
685 		struct cached_connection_params connection_params;
686 		cached_connection connection;
687 
688 		int result;
689 
690 		if (pidfin == NULL)
691 			errx(EXIT_FAILURE, "There is no daemon running.");
692 
693 		memset(pidbuf, 0, sizeof(pidbuf));
694 		fread(pidbuf, sizeof(pidbuf) - 1, 1, pidfin);
695 		fclose(pidfin);
696 
697 		if (ferror(pidfin) != 0)
698 			errx(EXIT_FAILURE, "Can't read from pidfile.");
699 
700 		if (sscanf(pidbuf, "%d", &pid) != 1)
701 			errx(EXIT_FAILURE, "Invalid pidfile.");
702 		LOG_MSG_1("main", "daemon PID is %d", pid);
703 
704 
705 		memset(&connection_params, 0,
706 			sizeof(struct cached_connection_params));
707 		connection_params.socket_path = DEFAULT_SOCKET_PATH;
708 		connection = open_cached_connection__(&connection_params);
709 		if (connection == INVALID_CACHED_CONNECTION)
710 			errx(EXIT_FAILURE, "Can't connect to the daemon.");
711 
712 		if (clear_user_cache_entries != 0) {
713 			result = cached_transform__(connection,
714 				user_config_entry_name, TT_USER);
715 			if (result != 0)
716 				LOG_MSG_1("main",
717 					"user cache transformation failed");
718 			else
719 				LOG_MSG_1("main",
720 					"user cache_transformation "
721 					"succeeded");
722 		}
723 
724 		if (clear_all_cache_entries != 0) {
725 			if (geteuid() != 0)
726 				errx(EXIT_FAILURE, "Only root can initiate "
727 					"global cache transformation.");
728 
729 			result = cached_transform__(connection,
730 				global_config_entry_name, TT_ALL);
731 			if (result != 0)
732 				LOG_MSG_1("main",
733 					"global cache transformation "
734 					"failed");
735 			else
736 				LOG_MSG_1("main",
737 					"global cache transformation "
738 					"succeeded");
739 		}
740 
741 		close_cached_connection__(connection);
742 
743 		free(user_config_entry_name);
744 		free(global_config_entry_name);
745 		return (EXIT_SUCCESS);
746 	}
747 
748 	pidfile = pidfile_open(DEFAULT_PIDFILE_PATH, 0644, &pid);
749 	if (pidfile == NULL) {
750 		if (errno == EEXIST)
751 			errx(EXIT_FAILURE, "Daemon already running, pid: %d.",
752 				pid);
753 		warn("Cannot open or create pidfile");
754 	}
755 
756 	if (trace_mode_enabled == 1)
757 		TRACE_ON();
758 
759 	/* blocking the main thread from receiving SIGPIPE signal */
760 	sigblock(sigmask(SIGPIPE));
761 
762 	/* daemonization */
763 	if (do_not_daemonize == 0) {
764 		res = daemon(0, trace_mode_enabled == 0 ? 0 : 1);
765 		if (res != 0) {
766 			LOG_ERR_1("main", "can't daemonize myself: %s",
767 		    		strerror(errno));
768 			pidfile_remove(pidfile);
769 			goto fin;
770 		} else
771 			LOG_MSG_1("main", "successfully daemonized");
772 	}
773 
774 	pidfile_write(pidfile);
775 
776 	s_agent_table = init_agent_table();
777 	register_agent(s_agent_table, init_passwd_agent());
778 	register_agent(s_agent_table, init_passwd_mp_agent());
779 	register_agent(s_agent_table, init_group_agent());
780 	register_agent(s_agent_table, init_group_mp_agent());
781 	register_agent(s_agent_table, init_services_agent());
782 	register_agent(s_agent_table, init_services_mp_agent());
783 	LOG_MSG_1("main", "request agents registered successfully");
784 
785 	/*
786  	 * Hosts agent can't work properly until we have access to the
787 	 * appropriate dtab structures, which are used in nsdispatch
788 	 * calls
789 	 *
790 	 register_agent(s_agent_table, init_hosts_agent());
791 	*/
792 
793 	/* configuration initialization */
794 	s_configuration = init_configuration();
795 	fill_configuration_defaults(s_configuration);
796 
797 	error_str = NULL;
798 	error_line = 0;
799 	config_file = CONFIG_PATH;
800 
801 	res = parse_config_file(s_configuration, config_file, &error_str,
802 		&error_line);
803 	if ((res != 0) && (error_str == NULL)) {
804 		config_file = DEFAULT_CONFIG_PATH;
805 		res = parse_config_file(s_configuration, config_file,
806 			&error_str, &error_line);
807 	}
808 
809 	if (res != 0) {
810 		if (error_str != NULL) {
811 		LOG_ERR_1("main", "error in configuration file(%s, %d): %s\n",
812 			config_file, error_line, error_str);
813 		} else {
814 		LOG_ERR_1("main", "no configuration file found "
815 		    	"- was looking for %s and %s",
816 			CONFIG_PATH, DEFAULT_CONFIG_PATH);
817 		}
818 		destroy_configuration(s_configuration);
819 		return (-1);
820 	}
821 
822 	if (force_single_threaded == 1)
823 		s_configuration->threads_num = 1;
824 
825 	/* cache initialization */
826 	s_cache = init_cache_(s_configuration);
827 	if (s_cache == NULL) {
828 		LOG_ERR_1("main", "can't initialize the cache");
829 		destroy_configuration(s_configuration);
830 		return (-1);
831 	}
832 
833 	/* runtime environment initialization */
834 	s_runtime_env = init_runtime_env(s_configuration);
835 	if (s_runtime_env == NULL) {
836 		LOG_ERR_1("main", "can't initialize the runtime environment");
837 		destroy_configuration(s_configuration);
838 		destroy_cache_(s_cache);
839 		return (-1);
840 	}
841 
842 	if (s_configuration->threads_num > 1) {
843 		threads = (pthread_t *)malloc(sizeof(pthread_t) *
844 			s_configuration->threads_num);
845 		memset(threads, 0, sizeof(pthread_t) *
846 	    		s_configuration->threads_num);
847 		for (i = 0; i < s_configuration->threads_num; ++i) {
848 			thread_args = (struct processing_thread_args *)malloc(
849 				sizeof(struct processing_thread_args));
850 			thread_args->the_cache = s_cache;
851 			thread_args->the_runtime_env = s_runtime_env;
852 			thread_args->the_configuration = s_configuration;
853 
854 			LOG_MSG_1("main", "thread #%d was successfully created",
855 				i);
856 			pthread_create(&threads[i], NULL, processing_thread,
857 				thread_args);
858 
859 			thread_args = NULL;
860 		}
861 
862 		for (i = 0; i < s_configuration->threads_num; ++i)
863 			pthread_join(threads[i], NULL);
864 	} else {
865 		LOG_MSG_1("main", "working in single-threaded mode");
866 		processing_loop(s_cache, s_runtime_env, s_configuration);
867 	}
868 
869 fin:
870 	/* runtime environment destruction */
871 	destroy_runtime_env(s_runtime_env);
872 
873 	/* cache destruction */
874 	destroy_cache_(s_cache);
875 
876 	/* configuration destruction */
877 	destroy_configuration(s_configuration);
878 
879 	/* agents table destruction */
880 	destroy_agent_table(s_agent_table);
881 
882 	pidfile_remove(pidfile);
883 	return (EXIT_SUCCESS);
884 }
885