xref: /freebsd/usr.sbin/nscd/nscd.c (revision 4d65a7c6951cea0333f1a0c1b32c38489cdfa6c5)
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/param.h>
29 #include <sys/event.h>
30 #include <sys/socket.h>
31 #include <sys/stat.h>
32 #include <sys/time.h>
33 #include <sys/un.h>
34 
35 #include <assert.h>
36 #include <err.h>
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <libutil.h>
40 #include <pthread.h>
41 #include <signal.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 
47 #include "agents/passwd.h"
48 #include "agents/group.h"
49 #include "agents/services.h"
50 #include "cachelib.h"
51 #include "config.h"
52 #include "debug.h"
53 #include "log.h"
54 #include "nscdcli.h"
55 #include "parser.h"
56 #include "query.h"
57 #include "singletons.h"
58 
59 #ifndef CONFIG_PATH
60 #define CONFIG_PATH "/etc/nscd.conf"
61 #endif
62 #define DEFAULT_CONFIG_PATH	"nscd.conf"
63 
64 #define MAX_SOCKET_IO_SIZE	4096
65 
66 struct processing_thread_args {
67 	cache	the_cache;
68 	struct configuration	*the_configuration;
69 	struct runtime_env		*the_runtime_env;
70 };
71 
72 static void accept_connection(struct kevent *, struct runtime_env *,
73 	struct configuration *);
74 static void destroy_cache_(cache);
75 static void destroy_runtime_env(struct runtime_env *);
76 static cache init_cache_(struct configuration *);
77 static struct runtime_env *init_runtime_env(struct configuration *);
78 static void processing_loop(cache, struct runtime_env *,
79 	struct configuration *);
80 static void process_socket_event(struct kevent *, struct runtime_env *,
81 	struct configuration *);
82 static void process_timer_event(struct kevent *, struct runtime_env *,
83 	struct configuration *);
84 static void *processing_thread(void *);
85 static void usage(void) __dead2;
86 
87 void get_time_func(struct timeval *);
88 
89 static void
usage(void)90 usage(void)
91 {
92 	fprintf(stderr,
93 	    "usage: nscd [-dnst] [-i cachename] [-I cachename]\n");
94 	exit(1);
95 }
96 
97 static cache
init_cache_(struct configuration * config)98 init_cache_(struct configuration *config)
99 {
100 	struct cache_params params;
101 	cache retval;
102 
103 	struct configuration_entry *config_entry;
104 	size_t	size, i;
105 
106 	TRACE_IN(init_cache_);
107 
108 	memset(&params, 0, sizeof(struct cache_params));
109 	params.get_time_func = get_time_func;
110 	retval = init_cache(&params);
111 
112 	size = configuration_get_entries_size(config);
113 	for (i = 0; i < size; ++i) {
114 		config_entry = configuration_get_entry(config, i);
115 	    	/*
116 	    	 * We should register common entries now - multipart entries
117 	    	 * would be registered automatically during the queries.
118 	    	 */
119 		register_cache_entry(retval, (struct cache_entry_params *)
120 			&config_entry->positive_cache_params);
121 		config_entry->positive_cache_entry = find_cache_entry(retval,
122 			config_entry->positive_cache_params.cep.entry_name);
123 		assert(config_entry->positive_cache_entry !=
124 			INVALID_CACHE_ENTRY);
125 
126 		register_cache_entry(retval, (struct cache_entry_params *)
127 			&config_entry->negative_cache_params);
128 		config_entry->negative_cache_entry = find_cache_entry(retval,
129 			config_entry->negative_cache_params.cep.entry_name);
130 		assert(config_entry->negative_cache_entry !=
131 			INVALID_CACHE_ENTRY);
132 	}
133 
134 	LOG_MSG_2("cache", "cache was successfully initialized");
135 	TRACE_OUT(init_cache_);
136 	return (retval);
137 }
138 
139 static void
destroy_cache_(cache the_cache)140 destroy_cache_(cache the_cache)
141 {
142 	TRACE_IN(destroy_cache_);
143 	destroy_cache(the_cache);
144 	TRACE_OUT(destroy_cache_);
145 }
146 
147 /*
148  * Socket and kqueues are prepared here. We have one global queue for both
149  * socket and timers events.
150  */
151 static struct runtime_env *
init_runtime_env(struct configuration * config)152 init_runtime_env(struct configuration *config)
153 {
154 	int serv_addr_len;
155 	struct sockaddr_un serv_addr;
156 
157 	struct kevent eventlist;
158 	struct timespec timeout;
159 
160 	struct runtime_env *retval;
161 
162 	TRACE_IN(init_runtime_env);
163 	retval = calloc(1, sizeof(*retval));
164 	assert(retval != NULL);
165 
166 	retval->sockfd = socket(PF_LOCAL, SOCK_STREAM, 0);
167 
168 	if (config->force_unlink == 1)
169 		unlink(config->socket_path);
170 
171 	memset(&serv_addr, 0, sizeof(struct sockaddr_un));
172 	serv_addr.sun_family = PF_LOCAL;
173 	strlcpy(serv_addr.sun_path, config->socket_path,
174 		sizeof(serv_addr.sun_path));
175 	serv_addr_len = sizeof(serv_addr.sun_family) +
176 		strlen(serv_addr.sun_path) + 1;
177 
178 	if (bind(retval->sockfd, (struct sockaddr *)&serv_addr,
179 		serv_addr_len) == -1) {
180 		close(retval->sockfd);
181 		free(retval);
182 
183 		LOG_ERR_2("runtime environment", "can't bind socket to path: "
184 			"%s", config->socket_path);
185 		TRACE_OUT(init_runtime_env);
186 		return (NULL);
187 	}
188 	LOG_MSG_2("runtime environment", "using socket %s",
189 		config->socket_path);
190 
191 	/*
192 	 * Here we're marking socket as non-blocking and setting its backlog
193 	 * to the maximum value
194 	 */
195 	chmod(config->socket_path, config->socket_mode);
196 	listen(retval->sockfd, -1);
197 	fcntl(retval->sockfd, F_SETFL, O_NONBLOCK);
198 
199 	retval->queue = kqueue();
200 	assert(retval->queue != -1);
201 
202 	EV_SET(&eventlist, retval->sockfd, EVFILT_READ, EV_ADD | EV_ONESHOT,
203 		0, 0, 0);
204 	memset(&timeout, 0, sizeof(struct timespec));
205 	kevent(retval->queue, &eventlist, 1, NULL, 0, &timeout);
206 
207 	LOG_MSG_2("runtime environment", "successfully initialized");
208 	TRACE_OUT(init_runtime_env);
209 	return (retval);
210 }
211 
212 static void
destroy_runtime_env(struct runtime_env * env)213 destroy_runtime_env(struct runtime_env *env)
214 {
215 	TRACE_IN(destroy_runtime_env);
216 	close(env->queue);
217 	close(env->sockfd);
218 	free(env);
219 	TRACE_OUT(destroy_runtime_env);
220 }
221 
222 static void
accept_connection(struct kevent * event_data,struct runtime_env * env,struct configuration * config)223 accept_connection(struct kevent *event_data, struct runtime_env *env,
224 	struct configuration *config)
225 {
226 	struct kevent	eventlist[2];
227 	struct timespec	timeout;
228 	struct query_state	*qstate;
229 
230 	int	fd;
231 	int	res;
232 
233 	uid_t	euid;
234 	gid_t	egid;
235 
236 	TRACE_IN(accept_connection);
237 	fd = accept(event_data->ident, NULL, NULL);
238 	if (fd == -1) {
239 		LOG_ERR_2("accept_connection", "error %d during accept()",
240 		    errno);
241 		TRACE_OUT(accept_connection);
242 		return;
243 	}
244 
245 	if (getpeereid(fd, &euid, &egid) != 0) {
246 		LOG_ERR_2("accept_connection", "error %d during getpeereid()",
247 			errno);
248 		TRACE_OUT(accept_connection);
249 		return;
250 	}
251 
252 	qstate = init_query_state(fd, sizeof(int), euid, egid);
253 	if (qstate == NULL) {
254 		LOG_ERR_2("accept_connection", "can't init query_state");
255 		TRACE_OUT(accept_connection);
256 		return;
257 	}
258 
259 	memset(&timeout, 0, sizeof(struct timespec));
260 	EV_SET(&eventlist[0], fd, EVFILT_TIMER, EV_ADD | EV_ONESHOT,
261 		0, qstate->timeout.tv_sec * 1000, qstate);
262 	EV_SET(&eventlist[1], fd, EVFILT_READ, EV_ADD | EV_ONESHOT,
263 		NOTE_LOWAT, qstate->kevent_watermark, qstate);
264 	res = kevent(env->queue, eventlist, 2, NULL, 0, &timeout);
265 	if (res < 0)
266 		LOG_ERR_2("accept_connection", "kevent error");
267 
268 	TRACE_OUT(accept_connection);
269 }
270 
271 static void
process_socket_event(struct kevent * event_data,struct runtime_env * env,struct configuration * config)272 process_socket_event(struct kevent *event_data, struct runtime_env *env,
273 	struct configuration *config)
274 {
275 	struct kevent	eventlist[2];
276 	struct timeval	query_timeout;
277 	struct timespec	kevent_timeout;
278 	int	nevents;
279 	int	eof_res, res;
280 	ssize_t	io_res;
281 	struct query_state *qstate;
282 
283 	TRACE_IN(process_socket_event);
284 	eof_res = event_data->flags & EV_EOF ? 1 : 0;
285 	res = 0;
286 
287 	memset(&kevent_timeout, 0, sizeof(struct timespec));
288 	EV_SET(&eventlist[0], event_data->ident, EVFILT_TIMER, EV_DELETE,
289 		0, 0, NULL);
290 	nevents = kevent(env->queue, eventlist, 1, NULL, 0, &kevent_timeout);
291 	if (nevents == -1) {
292 		if (errno == ENOENT) {
293 			/* the timer is already handling this event */
294 			TRACE_OUT(process_socket_event);
295 			return;
296 		} else {
297 			/* some other error happened */
298 			LOG_ERR_2("process_socket_event", "kevent error, errno"
299 				" is %d", errno);
300 			TRACE_OUT(process_socket_event);
301 			return;
302 		}
303 	}
304 	qstate = (struct query_state *)event_data->udata;
305 
306 	/*
307 	 * If the buffer that is to be send/received is too large,
308 	 * we send it implicitly, by using query_io_buffer_read and
309 	 * query_io_buffer_write functions in the query_state. These functions
310 	 * use the temporary buffer, which is later send/received in parts.
311 	 * The code below implements buffer splitting/mergind for send/receive
312 	 * operations. It also does the actual socket IO operations.
313 	 */
314 	if (((qstate->use_alternate_io == 0) &&
315 		(qstate->kevent_watermark <= (size_t)event_data->data)) ||
316 		((qstate->use_alternate_io != 0) &&
317 		(qstate->io_buffer_watermark <= (size_t)event_data->data))) {
318 		if (qstate->use_alternate_io != 0) {
319 			switch (qstate->io_buffer_filter) {
320 			case EVFILT_READ:
321 				io_res = query_socket_read(qstate,
322 					qstate->io_buffer_p,
323 					qstate->io_buffer_watermark);
324 				if (io_res < 0) {
325 					qstate->use_alternate_io = 0;
326 					qstate->process_func = NULL;
327 				} else {
328 					qstate->io_buffer_p += io_res;
329 					if (qstate->io_buffer_p ==
330 					    	qstate->io_buffer +
331 						qstate->io_buffer_size) {
332 						qstate->io_buffer_p =
333 						    qstate->io_buffer;
334 						qstate->use_alternate_io = 0;
335 					}
336 				}
337 			break;
338 			default:
339 			break;
340 			}
341 		}
342 
343 		if (qstate->use_alternate_io == 0) {
344 			do {
345 				res = qstate->process_func(qstate);
346 			} while ((qstate->kevent_watermark == 0) &&
347 					(qstate->process_func != NULL) &&
348 					(res == 0));
349 
350 			if (res != 0)
351 				qstate->process_func = NULL;
352 		}
353 
354 		if ((qstate->use_alternate_io != 0) &&
355 			(qstate->io_buffer_filter == EVFILT_WRITE)) {
356 			io_res = query_socket_write(qstate, qstate->io_buffer_p,
357 				qstate->io_buffer_watermark);
358 			if (io_res < 0) {
359 				qstate->use_alternate_io = 0;
360 				qstate->process_func = NULL;
361 			} else
362 				qstate->io_buffer_p += io_res;
363 		}
364 	} else {
365 		/* assuming that socket was closed */
366 		qstate->process_func = NULL;
367 		qstate->use_alternate_io = 0;
368 	}
369 
370 	if (((qstate->process_func == NULL) &&
371 	    	(qstate->use_alternate_io == 0)) ||
372 		(eof_res != 0) || (res != 0)) {
373 		destroy_query_state(qstate);
374 		close(event_data->ident);
375 		TRACE_OUT(process_socket_event);
376 		return;
377 	}
378 
379 	/* updating the query_state lifetime variable */
380 	get_time_func(&query_timeout);
381 	query_timeout.tv_usec = 0;
382 	query_timeout.tv_sec -= qstate->creation_time.tv_sec;
383 	if (query_timeout.tv_sec > qstate->timeout.tv_sec)
384 		query_timeout.tv_sec = 0;
385 	else
386 		query_timeout.tv_sec = qstate->timeout.tv_sec -
387 			query_timeout.tv_sec;
388 
389 	if ((qstate->use_alternate_io != 0) && (qstate->io_buffer_p ==
390 		qstate->io_buffer + qstate->io_buffer_size))
391 		qstate->use_alternate_io = 0;
392 
393 	if (qstate->use_alternate_io == 0) {
394 		/*
395 		 * If we must send/receive the large block of data,
396 		 * we should prepare the query_state's io_XXX fields.
397 		 * We should also substitute its write_func and read_func
398 		 * with the query_io_buffer_write and query_io_buffer_read,
399 		 * which will allow us to implicitly send/receive this large
400 		 * buffer later (in the subsequent calls to the
401 		 * process_socket_event).
402 		 */
403 		if (qstate->kevent_watermark > MAX_SOCKET_IO_SIZE) {
404 #if 0
405 			/*
406 			 * XXX: Uncommenting this code makes nscd(8) fail for
407 			 *      entries larger than a few kB, causing few second
408 			 *      worth of delay for each call to retrieve them.
409 			 */
410 			if (qstate->io_buffer != NULL)
411 				free(qstate->io_buffer);
412 
413 			qstate->io_buffer = calloc(1,
414 				qstate->kevent_watermark);
415 			assert(qstate->io_buffer != NULL);
416 
417 			qstate->io_buffer_p = qstate->io_buffer;
418 			qstate->io_buffer_size = qstate->kevent_watermark;
419 			qstate->io_buffer_filter = qstate->kevent_filter;
420 
421 			qstate->write_func = query_io_buffer_write;
422 			qstate->read_func = query_io_buffer_read;
423 
424 			if (qstate->kevent_filter == EVFILT_READ)
425 				qstate->use_alternate_io = 1;
426 #endif
427 
428 			qstate->io_buffer_watermark = MAX_SOCKET_IO_SIZE;
429 			EV_SET(&eventlist[1], event_data->ident,
430 				qstate->kevent_filter, EV_ADD | EV_ONESHOT,
431 				NOTE_LOWAT, MAX_SOCKET_IO_SIZE, qstate);
432 		} else {
433 			EV_SET(&eventlist[1], event_data->ident,
434 		    		qstate->kevent_filter, EV_ADD | EV_ONESHOT,
435 		    		NOTE_LOWAT, qstate->kevent_watermark, qstate);
436 		}
437 	} else {
438 		if (qstate->io_buffer + qstate->io_buffer_size -
439 		    	qstate->io_buffer_p <
440 			MAX_SOCKET_IO_SIZE) {
441 			qstate->io_buffer_watermark = qstate->io_buffer +
442 				qstate->io_buffer_size - qstate->io_buffer_p;
443 			EV_SET(&eventlist[1], event_data->ident,
444 			    	qstate->io_buffer_filter,
445 				EV_ADD | EV_ONESHOT, NOTE_LOWAT,
446 				qstate->io_buffer_watermark,
447 				qstate);
448 		} else {
449 			qstate->io_buffer_watermark = MAX_SOCKET_IO_SIZE;
450 			EV_SET(&eventlist[1], event_data->ident,
451 		    		qstate->io_buffer_filter, EV_ADD | EV_ONESHOT,
452 		    		NOTE_LOWAT, MAX_SOCKET_IO_SIZE, qstate);
453 		}
454 	}
455 	EV_SET(&eventlist[0], event_data->ident, EVFILT_TIMER,
456 		EV_ADD | EV_ONESHOT, 0, query_timeout.tv_sec * 1000, qstate);
457 	kevent(env->queue, eventlist, 2, NULL, 0, &kevent_timeout);
458 
459 	TRACE_OUT(process_socket_event);
460 }
461 
462 /*
463  * This routine is called if timer event has been signaled in the kqueue. It
464  * just closes the socket and destroys the query_state.
465  */
466 static void
process_timer_event(struct kevent * event_data,struct runtime_env * env,struct configuration * config)467 process_timer_event(struct kevent *event_data, struct runtime_env *env,
468 	struct configuration *config)
469 {
470 	struct query_state	*qstate;
471 
472 	TRACE_IN(process_timer_event);
473 	qstate = (struct query_state *)event_data->udata;
474 	destroy_query_state(qstate);
475 	close(event_data->ident);
476 	TRACE_OUT(process_timer_event);
477 }
478 
479 /*
480  * Processing loop is the basic processing routine, that forms a body of each
481  * procssing thread
482  */
483 static void
processing_loop(cache the_cache,struct runtime_env * env,struct configuration * config)484 processing_loop(cache the_cache, struct runtime_env *env,
485 	struct configuration *config)
486 {
487 	struct timespec timeout;
488 	const int eventlist_size = 1;
489 	struct kevent eventlist[eventlist_size];
490 	int nevents, i;
491 
492 	TRACE_MSG("=> processing_loop");
493 	memset(&timeout, 0, sizeof(struct timespec));
494 	memset(&eventlist, 0, sizeof(struct kevent) * eventlist_size);
495 
496 	for (;;) {
497 		nevents = kevent(env->queue, NULL, 0, eventlist,
498 	    		eventlist_size, NULL);
499 		/*
500 		 * we can only receive 1 event on success
501 		 */
502 		if (nevents == 1) {
503 			struct kevent *event_data;
504 			event_data = &eventlist[0];
505 
506 			if ((int)event_data->ident == env->sockfd) {
507 				for (i = 0; i < event_data->data; ++i)
508 				    accept_connection(event_data, env, config);
509 
510 				EV_SET(eventlist, s_runtime_env->sockfd,
511 				    EVFILT_READ, EV_ADD | EV_ONESHOT,
512 				    0, 0, 0);
513 				memset(&timeout, 0,
514 				    sizeof(struct timespec));
515 				kevent(s_runtime_env->queue, eventlist,
516 				    1, NULL, 0, &timeout);
517 
518 			} else {
519 				switch (event_data->filter) {
520 				case EVFILT_READ:
521 				case EVFILT_WRITE:
522 					process_socket_event(event_data,
523 						env, config);
524 					break;
525 				case EVFILT_TIMER:
526 					process_timer_event(event_data,
527 						env, config);
528 					break;
529 				default:
530 					break;
531 				}
532 			}
533 		} else {
534 			/* this branch shouldn't be currently executed */
535 		}
536 	}
537 
538 	TRACE_MSG("<= processing_loop");
539 }
540 
541 /*
542  * Wrapper above the processing loop function. It sets the thread signal mask
543  * to avoid SIGPIPE signals (which can happen if the client works incorrectly).
544  */
545 static void *
processing_thread(void * data)546 processing_thread(void *data)
547 {
548 	struct processing_thread_args	*args;
549 	sigset_t new;
550 
551 	TRACE_MSG("=> processing_thread");
552 	args = (struct processing_thread_args *)data;
553 
554 	sigemptyset(&new);
555 	sigaddset(&new, SIGPIPE);
556 	if (pthread_sigmask(SIG_BLOCK, &new, NULL) != 0)
557 		LOG_ERR_1("processing thread",
558 			"thread can't block the SIGPIPE signal");
559 
560 	processing_loop(args->the_cache, args->the_runtime_env,
561 		args->the_configuration);
562 	free(args);
563 	TRACE_MSG("<= processing_thread");
564 
565 	return (NULL);
566 }
567 
568 void
get_time_func(struct timeval * time)569 get_time_func(struct timeval *time)
570 {
571 	struct timespec res;
572 	memset(&res, 0, sizeof(struct timespec));
573 	clock_gettime(CLOCK_MONOTONIC, &res);
574 
575 	time->tv_sec = res.tv_sec;
576 	time->tv_usec = 0;
577 }
578 
579 /*
580  * The idea of _nss_cache_cycle_prevention_function is that nsdispatch
581  * will search for this symbol in the executable. This symbol is the
582  * attribute of the caching daemon. So, if it exists, nsdispatch won't try
583  * to connect to the caching daemon and will just ignore the 'cache'
584  * source in the nsswitch.conf. This method helps to avoid cycles and
585  * organize self-performing requests.
586  *
587  * (not actually a function; it used to be, but it doesn't make any
588  * difference, as long as it has external linkage)
589  */
590 void *_nss_cache_cycle_prevention_function;
591 
592 int
main(int argc,char * argv[])593 main(int argc, char *argv[])
594 {
595 	struct processing_thread_args *thread_args;
596 	pthread_t *threads;
597 
598 	struct pidfh *pidfile;
599 	pid_t pid;
600 
601 	char const *config_file;
602 	char const *error_str;
603 	int error_line;
604 	int i, res;
605 
606 	int trace_mode_enabled;
607 	int force_single_threaded;
608 	int do_not_daemonize;
609 	int clear_user_cache_entries, clear_all_cache_entries;
610 	char *user_config_entry_name, *global_config_entry_name;
611 	int show_statistics;
612 	int daemon_mode, interactive_mode;
613 
614 
615 	/* by default all debug messages are omitted */
616 	TRACE_OFF();
617 
618 	/* parsing command line arguments */
619 	trace_mode_enabled = 0;
620 	force_single_threaded = 0;
621 	do_not_daemonize = 0;
622 	clear_user_cache_entries = 0;
623 	clear_all_cache_entries = 0;
624 	show_statistics = 0;
625 	user_config_entry_name = NULL;
626 	global_config_entry_name = NULL;
627 	while ((res = getopt(argc, argv, "nstdi:I:")) != -1) {
628 		switch (res) {
629 		case 'n':
630 			do_not_daemonize = 1;
631 			break;
632 		case 's':
633 			force_single_threaded = 1;
634 			break;
635 		case 't':
636 			trace_mode_enabled = 1;
637 			break;
638 		case 'i':
639 			clear_user_cache_entries = 1;
640 			if (optarg != NULL)
641 				if (strcmp(optarg, "all") != 0)
642 					user_config_entry_name = strdup(optarg);
643 			break;
644 		case 'I':
645 			clear_all_cache_entries = 1;
646 			if (optarg != NULL)
647 				if (strcmp(optarg, "all") != 0)
648 					global_config_entry_name =
649 						strdup(optarg);
650 			break;
651 		case 'd':
652 			show_statistics = 1;
653 			break;
654 		case '?':
655 		default:
656 			usage();
657 			/* NOT REACHED */
658 		}
659 	}
660 
661 	daemon_mode = do_not_daemonize | force_single_threaded |
662 		trace_mode_enabled;
663 	interactive_mode = clear_user_cache_entries | clear_all_cache_entries |
664 		show_statistics;
665 
666 	if ((daemon_mode != 0) && (interactive_mode != 0)) {
667 		LOG_ERR_1("main", "daemon mode and interactive_mode arguments "
668 			"can't be used together");
669 		usage();
670 	}
671 
672 	if (interactive_mode != 0) {
673 		FILE *pidfin = fopen(DEFAULT_PIDFILE_PATH, "r");
674 		char pidbuf[256];
675 
676 		struct nscd_connection_params connection_params;
677 		nscd_connection connection;
678 
679 		int result;
680 
681 		if (pidfin == NULL)
682 			errx(EXIT_FAILURE, "There is no daemon running.");
683 
684 		memset(pidbuf, 0, sizeof(pidbuf));
685 		fread(pidbuf, sizeof(pidbuf) - 1, 1, pidfin);
686 		fclose(pidfin);
687 
688 		if (ferror(pidfin) != 0)
689 			errx(EXIT_FAILURE, "Can't read from pidfile.");
690 
691 		if (sscanf(pidbuf, "%d", &pid) != 1)
692 			errx(EXIT_FAILURE, "Invalid pidfile.");
693 		LOG_MSG_1("main", "daemon PID is %d", pid);
694 
695 
696 		memset(&connection_params, 0,
697 			sizeof(struct nscd_connection_params));
698 		connection_params.socket_path = DEFAULT_SOCKET_PATH;
699 		connection = open_nscd_connection__(&connection_params);
700 		if (connection == INVALID_NSCD_CONNECTION)
701 			errx(EXIT_FAILURE, "Can't connect to the daemon.");
702 
703 		if (clear_user_cache_entries != 0) {
704 			result = nscd_transform__(connection,
705 				user_config_entry_name, TT_USER);
706 			if (result != 0)
707 				LOG_MSG_1("main",
708 					"user cache transformation failed");
709 			else
710 				LOG_MSG_1("main",
711 					"user cache_transformation "
712 					"succeeded");
713 		}
714 
715 		if (clear_all_cache_entries != 0) {
716 			if (geteuid() != 0)
717 				errx(EXIT_FAILURE, "Only root can initiate "
718 					"global cache transformation.");
719 
720 			result = nscd_transform__(connection,
721 				global_config_entry_name, TT_ALL);
722 			if (result != 0)
723 				LOG_MSG_1("main",
724 					"global cache transformation "
725 					"failed");
726 			else
727 				LOG_MSG_1("main",
728 					"global cache transformation "
729 					"succeeded");
730 		}
731 
732 		close_nscd_connection__(connection);
733 
734 		free(user_config_entry_name);
735 		free(global_config_entry_name);
736 		return (EXIT_SUCCESS);
737 	}
738 
739 	pidfile = pidfile_open(DEFAULT_PIDFILE_PATH, 0644, &pid);
740 	if (pidfile == NULL) {
741 		if (errno == EEXIST)
742 			errx(EXIT_FAILURE, "Daemon already running, pid: %d.",
743 				pid);
744 		warn("Cannot open or create pidfile");
745 	}
746 
747 	if (trace_mode_enabled == 1)
748 		TRACE_ON();
749 
750 	/* blocking the main thread from receiving SIGPIPE signal */
751 	sigblock(sigmask(SIGPIPE));
752 
753 	/* daemonization */
754 	if (do_not_daemonize == 0) {
755 		res = daemon(0, trace_mode_enabled == 0 ? 0 : 1);
756 		if (res != 0) {
757 			LOG_ERR_1("main", "can't daemonize myself: %s",
758 		    		strerror(errno));
759 			pidfile_remove(pidfile);
760 			goto fin;
761 		} else
762 			LOG_MSG_1("main", "successfully daemonized");
763 	}
764 
765 	pidfile_write(pidfile);
766 
767 	s_agent_table = init_agent_table();
768 	register_agent(s_agent_table, init_passwd_agent());
769 	register_agent(s_agent_table, init_passwd_mp_agent());
770 	register_agent(s_agent_table, init_group_agent());
771 	register_agent(s_agent_table, init_group_mp_agent());
772 	register_agent(s_agent_table, init_services_agent());
773 	register_agent(s_agent_table, init_services_mp_agent());
774 	LOG_MSG_1("main", "request agents registered successfully");
775 
776 	/*
777  	 * Hosts agent can't work properly until we have access to the
778 	 * appropriate dtab structures, which are used in nsdispatch
779 	 * calls
780 	 *
781 	 register_agent(s_agent_table, init_hosts_agent());
782 	*/
783 
784 	/* configuration initialization */
785 	s_configuration = init_configuration();
786 	fill_configuration_defaults(s_configuration);
787 
788 	error_str = NULL;
789 	error_line = 0;
790 	config_file = CONFIG_PATH;
791 
792 	res = parse_config_file(s_configuration, config_file, &error_str,
793 		&error_line);
794 	if ((res != 0) && (error_str == NULL)) {
795 		config_file = DEFAULT_CONFIG_PATH;
796 		res = parse_config_file(s_configuration, config_file,
797 			&error_str, &error_line);
798 	}
799 
800 	if (res != 0) {
801 		if (error_str != NULL) {
802 		LOG_ERR_1("main", "error in configuration file(%s, %d): %s\n",
803 			config_file, error_line, error_str);
804 		} else {
805 		LOG_ERR_1("main", "no configuration file found "
806 		    	"- was looking for %s and %s",
807 			CONFIG_PATH, DEFAULT_CONFIG_PATH);
808 		}
809 		destroy_configuration(s_configuration);
810 		return (-1);
811 	}
812 
813 	if (force_single_threaded == 1)
814 		s_configuration->threads_num = 1;
815 
816 	/* cache initialization */
817 	s_cache = init_cache_(s_configuration);
818 	if (s_cache == NULL) {
819 		LOG_ERR_1("main", "can't initialize the cache");
820 		destroy_configuration(s_configuration);
821 		return (-1);
822 	}
823 
824 	/* runtime environment initialization */
825 	s_runtime_env = init_runtime_env(s_configuration);
826 	if (s_runtime_env == NULL) {
827 		LOG_ERR_1("main", "can't initialize the runtime environment");
828 		destroy_configuration(s_configuration);
829 		destroy_cache_(s_cache);
830 		return (-1);
831 	}
832 
833 	if (s_configuration->threads_num > 1) {
834 		threads = calloc(s_configuration->threads_num,
835 			sizeof(*threads));
836 		for (i = 0; i < s_configuration->threads_num; ++i) {
837 			thread_args = malloc(
838 				sizeof(*thread_args));
839 			thread_args->the_cache = s_cache;
840 			thread_args->the_runtime_env = s_runtime_env;
841 			thread_args->the_configuration = s_configuration;
842 
843 			LOG_MSG_1("main", "thread #%d was successfully created",
844 				i);
845 			pthread_create(&threads[i], NULL, processing_thread,
846 				thread_args);
847 
848 			thread_args = NULL;
849 		}
850 
851 		for (i = 0; i < s_configuration->threads_num; ++i)
852 			pthread_join(threads[i], NULL);
853 	} else {
854 		LOG_MSG_1("main", "working in single-threaded mode");
855 		processing_loop(s_cache, s_runtime_env, s_configuration);
856 	}
857 
858 fin:
859 	/* runtime environment destruction */
860 	destroy_runtime_env(s_runtime_env);
861 
862 	/* cache destruction */
863 	destroy_cache_(s_cache);
864 
865 	/* configuration destruction */
866 	destroy_configuration(s_configuration);
867 
868 	/* agents table destruction */
869 	destroy_agent_table(s_agent_table);
870 
871 	pidfile_remove(pidfile);
872 	return (EXIT_SUCCESS);
873 }
874