xref: /freebsd/contrib/wpa/src/utils/eloop.c (revision 5bb3134a8c21cb87b30e135ef168483f0333dabb)
1 /*
2  * Event loop based on select() loop
3  * Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8 
9 #include "includes.h"
10 #include <assert.h>
11 
12 #include "common.h"
13 #include "trace.h"
14 #include "list.h"
15 #include "eloop.h"
16 
17 #if defined(CONFIG_ELOOP_POLL) && defined(CONFIG_ELOOP_EPOLL)
18 #error Do not define both of poll and epoll
19 #endif
20 
21 #if defined(CONFIG_ELOOP_POLL) && defined(CONFIG_ELOOP_KQUEUE)
22 #error Do not define both of poll and kqueue
23 #endif
24 
25 #if !defined(CONFIG_ELOOP_POLL) && !defined(CONFIG_ELOOP_EPOLL) && \
26     !defined(CONFIG_ELOOP_KQUEUE)
27 #define CONFIG_ELOOP_SELECT
28 #endif
29 
30 #ifdef CONFIG_ELOOP_POLL
31 #include <poll.h>
32 #endif /* CONFIG_ELOOP_POLL */
33 
34 #ifdef CONFIG_ELOOP_EPOLL
35 #include <sys/epoll.h>
36 #endif /* CONFIG_ELOOP_EPOLL */
37 
38 #ifdef CONFIG_ELOOP_KQUEUE
39 #include <sys/event.h>
40 #endif /* CONFIG_ELOOP_KQUEUE */
41 
42 struct eloop_sock {
43 	int sock;
44 	void *eloop_data;
45 	void *user_data;
46 	eloop_sock_handler handler;
47 	WPA_TRACE_REF(eloop);
48 	WPA_TRACE_REF(user);
49 	WPA_TRACE_INFO
50 };
51 
52 struct eloop_timeout {
53 	struct dl_list list;
54 	struct os_reltime time;
55 	void *eloop_data;
56 	void *user_data;
57 	eloop_timeout_handler handler;
58 	WPA_TRACE_REF(eloop);
59 	WPA_TRACE_REF(user);
60 	WPA_TRACE_INFO
61 };
62 
63 struct eloop_signal {
64 	int sig;
65 	void *user_data;
66 	eloop_signal_handler handler;
67 	int signaled;
68 };
69 
70 struct eloop_sock_table {
71 	size_t count;
72 	struct eloop_sock *table;
73 	eloop_event_type type;
74 	int changed;
75 };
76 
77 struct eloop_data {
78 	int max_sock;
79 
80 	size_t count; /* sum of all table counts */
81 #ifdef CONFIG_ELOOP_POLL
82 	size_t max_pollfd_map; /* number of pollfds_map currently allocated */
83 	size_t max_poll_fds; /* number of pollfds currently allocated */
84 	struct pollfd *pollfds;
85 	struct pollfd **pollfds_map;
86 #endif /* CONFIG_ELOOP_POLL */
87 #if defined(CONFIG_ELOOP_EPOLL) || defined(CONFIG_ELOOP_KQUEUE)
88 	int max_fd;
89 	struct eloop_sock *fd_table;
90 #endif /* CONFIG_ELOOP_EPOLL || CONFIG_ELOOP_KQUEUE */
91 #ifdef CONFIG_ELOOP_EPOLL
92 	int epollfd;
93 	size_t epoll_max_event_num;
94 	struct epoll_event *epoll_events;
95 #endif /* CONFIG_ELOOP_EPOLL */
96 #ifdef CONFIG_ELOOP_KQUEUE
97 	int kqueuefd;
98 	size_t kqueue_nevents;
99 	struct kevent *kqueue_events;
100 #endif /* CONFIG_ELOOP_KQUEUE */
101 	struct eloop_sock_table readers;
102 	struct eloop_sock_table writers;
103 	struct eloop_sock_table exceptions;
104 
105 	struct dl_list timeout;
106 
107 	size_t signal_count;
108 	struct eloop_signal *signals;
109 	int signaled;
110 	int pending_terminate;
111 
112 	int terminate;
113 };
114 
115 static struct eloop_data eloop;
116 
117 
118 #ifdef WPA_TRACE
119 
120 static void eloop_sigsegv_handler(int sig)
121 {
122 	wpa_trace_show("eloop SIGSEGV");
123 	abort();
124 }
125 
126 static void eloop_trace_sock_add_ref(struct eloop_sock_table *table)
127 {
128 	size_t i;
129 
130 	if (table == NULL || table->table == NULL)
131 		return;
132 	for (i = 0; i < table->count; i++) {
133 		wpa_trace_add_ref(&table->table[i], eloop,
134 				  table->table[i].eloop_data);
135 		wpa_trace_add_ref(&table->table[i], user,
136 				  table->table[i].user_data);
137 	}
138 }
139 
140 
141 static void eloop_trace_sock_remove_ref(struct eloop_sock_table *table)
142 {
143 	size_t i;
144 
145 	if (table == NULL || table->table == NULL)
146 		return;
147 	for (i = 0; i < table->count; i++) {
148 		wpa_trace_remove_ref(&table->table[i], eloop,
149 				     table->table[i].eloop_data);
150 		wpa_trace_remove_ref(&table->table[i], user,
151 				     table->table[i].user_data);
152 	}
153 }
154 
155 #else /* WPA_TRACE */
156 
157 #define eloop_trace_sock_add_ref(table) do { } while (0)
158 #define eloop_trace_sock_remove_ref(table) do { } while (0)
159 
160 #endif /* WPA_TRACE */
161 
162 
163 int eloop_init(void)
164 {
165 	os_memset(&eloop, 0, sizeof(eloop));
166 	dl_list_init(&eloop.timeout);
167 #ifdef CONFIG_ELOOP_EPOLL
168 	eloop.epollfd = epoll_create1(0);
169 	if (eloop.epollfd < 0) {
170 		wpa_printf(MSG_ERROR, "%s: epoll_create1 failed. %s",
171 			   __func__, strerror(errno));
172 		return -1;
173 	}
174 #endif /* CONFIG_ELOOP_EPOLL */
175 #ifdef CONFIG_ELOOP_KQUEUE
176 	eloop.kqueuefd = kqueue();
177 	if (eloop.kqueuefd < 0) {
178 		wpa_printf(MSG_ERROR, "%s: kqueue failed: %s",
179 			   __func__, strerror(errno));
180 		return -1;
181 	}
182 #endif /* CONFIG_ELOOP_KQUEUE */
183 #if defined(CONFIG_ELOOP_EPOLL) || defined(CONFIG_ELOOP_KQUEUE)
184 	eloop.readers.type = EVENT_TYPE_READ;
185 	eloop.writers.type = EVENT_TYPE_WRITE;
186 	eloop.exceptions.type = EVENT_TYPE_EXCEPTION;
187 #endif /* CONFIG_ELOOP_EPOLL || CONFIG_ELOOP_KQUEUE */
188 #ifdef WPA_TRACE
189 	signal(SIGSEGV, eloop_sigsegv_handler);
190 #endif /* WPA_TRACE */
191 	return 0;
192 }
193 
194 
195 #ifdef CONFIG_ELOOP_EPOLL
196 static int eloop_sock_queue(int sock, eloop_event_type type)
197 {
198 	struct epoll_event ev;
199 
200 	os_memset(&ev, 0, sizeof(ev));
201 	switch (type) {
202 	case EVENT_TYPE_READ:
203 		ev.events = EPOLLIN;
204 		break;
205 	case EVENT_TYPE_WRITE:
206 		ev.events = EPOLLOUT;
207 		break;
208 	/*
209 	 * Exceptions are always checked when using epoll, but I suppose it's
210 	 * possible that someone registered a socket *only* for exception
211 	 * handling.
212 	 */
213 	case EVENT_TYPE_EXCEPTION:
214 		ev.events = EPOLLERR | EPOLLHUP;
215 		break;
216 	}
217 	ev.data.fd = sock;
218 	if (epoll_ctl(eloop.epollfd, EPOLL_CTL_ADD, sock, &ev) < 0) {
219 		wpa_printf(MSG_ERROR, "%s: epoll_ctl(ADD) for fd=%d failed: %s",
220 			   __func__, sock, strerror(errno));
221 		return -1;
222 	}
223 	return 0;
224 }
225 #endif /* CONFIG_ELOOP_EPOLL */
226 
227 
228 #ifdef CONFIG_ELOOP_KQUEUE
229 
230 static short event_type_kevent_filter(eloop_event_type type)
231 {
232 	switch (type) {
233 	case EVENT_TYPE_READ:
234 		return EVFILT_READ;
235 	case EVENT_TYPE_WRITE:
236 		return EVFILT_WRITE;
237 	default:
238 		return 0;
239 	}
240 }
241 
242 
243 static int eloop_sock_queue(int sock, eloop_event_type type)
244 {
245 	struct kevent ke;
246 
247 	EV_SET(&ke, sock, event_type_kevent_filter(type), EV_ADD, 0, 0, 0);
248 	if (kevent(eloop.kqueuefd, &ke, 1, NULL, 0, NULL) == -1) {
249 		wpa_printf(MSG_ERROR, "%s: kevent(ADD) for fd=%d failed: %s",
250 			   __func__, sock, strerror(errno));
251 		return -1;
252 	}
253 	return 0;
254 }
255 
256 #endif /* CONFIG_ELOOP_KQUEUE */
257 
258 
259 static int eloop_sock_table_add_sock(struct eloop_sock_table *table,
260                                      int sock, eloop_sock_handler handler,
261                                      void *eloop_data, void *user_data)
262 {
263 #ifdef CONFIG_ELOOP_EPOLL
264 	struct epoll_event *temp_events;
265 #endif /* CONFIG_ELOOP_EPOLL */
266 #ifdef CONFIG_ELOOP_KQUEUE
267 	struct kevent *temp_events;
268 #endif /* CONFIG_ELOOP_EPOLL */
269 #if defined(CONFIG_ELOOP_EPOLL) || defined(CONFIG_ELOOP_KQUEUE)
270 	struct eloop_sock *temp_table;
271 	size_t next;
272 #endif /* CONFIG_ELOOP_EPOLL || CONFIG_ELOOP_KQUEUE */
273 	struct eloop_sock *tmp;
274 	int new_max_sock;
275 
276 	if (sock > eloop.max_sock)
277 		new_max_sock = sock;
278 	else
279 		new_max_sock = eloop.max_sock;
280 
281 	if (table == NULL)
282 		return -1;
283 
284 #ifdef CONFIG_ELOOP_POLL
285 	if ((size_t) new_max_sock >= eloop.max_pollfd_map) {
286 		struct pollfd **nmap;
287 		nmap = os_realloc_array(eloop.pollfds_map, new_max_sock + 50,
288 					sizeof(struct pollfd *));
289 		if (nmap == NULL)
290 			return -1;
291 
292 		eloop.max_pollfd_map = new_max_sock + 50;
293 		eloop.pollfds_map = nmap;
294 	}
295 
296 	if (eloop.count + 1 > eloop.max_poll_fds) {
297 		struct pollfd *n;
298 		size_t nmax = eloop.count + 1 + 50;
299 
300 		n = os_realloc_array(eloop.pollfds, nmax,
301 				     sizeof(struct pollfd));
302 		if (n == NULL)
303 			return -1;
304 
305 		eloop.max_poll_fds = nmax;
306 		eloop.pollfds = n;
307 	}
308 #endif /* CONFIG_ELOOP_POLL */
309 #if defined(CONFIG_ELOOP_EPOLL) || defined(CONFIG_ELOOP_KQUEUE)
310 	if (new_max_sock >= eloop.max_fd) {
311 		next = new_max_sock + 16;
312 		temp_table = os_realloc_array(eloop.fd_table, next,
313 					      sizeof(struct eloop_sock));
314 		if (temp_table == NULL)
315 			return -1;
316 
317 		eloop.max_fd = next;
318 		eloop.fd_table = temp_table;
319 	}
320 #endif /* CONFIG_ELOOP_EPOLL || CONFIG_ELOOP_KQUEUE */
321 
322 #ifdef CONFIG_ELOOP_EPOLL
323 	if (eloop.count + 1 > eloop.epoll_max_event_num) {
324 		next = eloop.epoll_max_event_num == 0 ? 8 :
325 			eloop.epoll_max_event_num * 2;
326 		temp_events = os_realloc_array(eloop.epoll_events, next,
327 					       sizeof(struct epoll_event));
328 		if (temp_events == NULL) {
329 			wpa_printf(MSG_ERROR, "%s: malloc for epoll failed: %s",
330 				   __func__, strerror(errno));
331 			return -1;
332 		}
333 
334 		eloop.epoll_max_event_num = next;
335 		eloop.epoll_events = temp_events;
336 	}
337 #endif /* CONFIG_ELOOP_EPOLL */
338 #ifdef CONFIG_ELOOP_KQUEUE
339 	if (eloop.count + 1 > eloop.kqueue_nevents) {
340 		next = eloop.kqueue_nevents == 0 ? 8 : eloop.kqueue_nevents * 2;
341 		temp_events = os_malloc(next * sizeof(*temp_events));
342 		if (!temp_events) {
343 			wpa_printf(MSG_ERROR,
344 				   "%s: malloc for kqueue failed: %s",
345 				   __func__, strerror(errno));
346 			return -1;
347 		}
348 
349 		os_free(eloop.kqueue_events);
350 		eloop.kqueue_events = temp_events;
351 		eloop.kqueue_nevents = next;
352 	}
353 #endif /* CONFIG_ELOOP_KQUEUE */
354 
355 	eloop_trace_sock_remove_ref(table);
356 	tmp = os_realloc_array(table->table, table->count + 1,
357 			       sizeof(struct eloop_sock));
358 	if (tmp == NULL) {
359 		eloop_trace_sock_add_ref(table);
360 		return -1;
361 	}
362 
363 	tmp[table->count].sock = sock;
364 	tmp[table->count].eloop_data = eloop_data;
365 	tmp[table->count].user_data = user_data;
366 	tmp[table->count].handler = handler;
367 	wpa_trace_record(&tmp[table->count]);
368 	table->count++;
369 	table->table = tmp;
370 	eloop.max_sock = new_max_sock;
371 	eloop.count++;
372 	table->changed = 1;
373 	eloop_trace_sock_add_ref(table);
374 
375 #if defined(CONFIG_ELOOP_EPOLL) || defined(CONFIG_ELOOP_KQUEUE)
376 	if (eloop_sock_queue(sock, table->type) < 0)
377 		return -1;
378 	os_memcpy(&eloop.fd_table[sock], &table->table[table->count - 1],
379 		  sizeof(struct eloop_sock));
380 #endif /* CONFIG_ELOOP_EPOLL || CONFIG_ELOOP_KQUEUE */
381 	return 0;
382 }
383 
384 
385 static void eloop_sock_table_remove_sock(struct eloop_sock_table *table,
386                                          int sock)
387 {
388 #ifdef CONFIG_ELOOP_KQUEUE
389 	struct kevent ke;
390 #endif /* CONFIG_ELOOP_KQUEUE */
391 	size_t i;
392 
393 	if (table == NULL || table->table == NULL || table->count == 0)
394 		return;
395 
396 	for (i = 0; i < table->count; i++) {
397 		if (table->table[i].sock == sock)
398 			break;
399 	}
400 	if (i == table->count)
401 		return;
402 	eloop_trace_sock_remove_ref(table);
403 	if (i != table->count - 1) {
404 		os_memmove(&table->table[i], &table->table[i + 1],
405 			   (table->count - i - 1) *
406 			   sizeof(struct eloop_sock));
407 	}
408 	table->count--;
409 	eloop.count--;
410 	table->changed = 1;
411 	eloop_trace_sock_add_ref(table);
412 #ifdef CONFIG_ELOOP_EPOLL
413 	if (epoll_ctl(eloop.epollfd, EPOLL_CTL_DEL, sock, NULL) < 0) {
414 		wpa_printf(MSG_ERROR, "%s: epoll_ctl(DEL) for fd=%d failed: %s",
415 			   __func__, sock, strerror(errno));
416 		return;
417 	}
418 	os_memset(&eloop.fd_table[sock], 0, sizeof(struct eloop_sock));
419 #endif /* CONFIG_ELOOP_EPOLL */
420 #ifdef CONFIG_ELOOP_KQUEUE
421 	EV_SET(&ke, sock, event_type_kevent_filter(table->type), EV_DELETE, 0,
422 	       0, 0);
423 	if (kevent(eloop.kqueuefd, &ke, 1, NULL, 0, NULL) < 0) {
424 		wpa_printf(MSG_ERROR, "%s: kevent(DEL) for fd=%d failed: %s",
425 			   __func__, sock, strerror(errno));
426 		return;
427 	}
428 	os_memset(&eloop.fd_table[sock], 0, sizeof(struct eloop_sock));
429 #endif /* CONFIG_ELOOP_KQUEUE */
430 }
431 
432 
433 #ifdef CONFIG_ELOOP_POLL
434 
435 static struct pollfd * find_pollfd(struct pollfd **pollfds_map, int fd, int mx)
436 {
437 	if (fd < mx && fd >= 0)
438 		return pollfds_map[fd];
439 	return NULL;
440 }
441 
442 
443 static int eloop_sock_table_set_fds(struct eloop_sock_table *readers,
444 				    struct eloop_sock_table *writers,
445 				    struct eloop_sock_table *exceptions,
446 				    struct pollfd *pollfds,
447 				    struct pollfd **pollfds_map,
448 				    int max_pollfd_map)
449 {
450 	size_t i;
451 	int nxt = 0;
452 	int fd;
453 	struct pollfd *pfd;
454 
455 	/* Clear pollfd lookup map. It will be re-populated below. */
456 	os_memset(pollfds_map, 0, sizeof(struct pollfd *) * max_pollfd_map);
457 
458 	if (readers && readers->table) {
459 		for (i = 0; i < readers->count; i++) {
460 			fd = readers->table[i].sock;
461 			assert(fd >= 0 && fd < max_pollfd_map);
462 			pollfds[nxt].fd = fd;
463 			pollfds[nxt].events = POLLIN;
464 			pollfds[nxt].revents = 0;
465 			pollfds_map[fd] = &(pollfds[nxt]);
466 			nxt++;
467 		}
468 	}
469 
470 	if (writers && writers->table) {
471 		for (i = 0; i < writers->count; i++) {
472 			/*
473 			 * See if we already added this descriptor, update it
474 			 * if so.
475 			 */
476 			fd = writers->table[i].sock;
477 			assert(fd >= 0 && fd < max_pollfd_map);
478 			pfd = pollfds_map[fd];
479 			if (!pfd) {
480 				pfd = &(pollfds[nxt]);
481 				pfd->events = 0;
482 				pfd->fd = fd;
483 				pollfds[i].revents = 0;
484 				pollfds_map[fd] = pfd;
485 				nxt++;
486 			}
487 			pfd->events |= POLLOUT;
488 		}
489 	}
490 
491 	/*
492 	 * Exceptions are always checked when using poll, but I suppose it's
493 	 * possible that someone registered a socket *only* for exception
494 	 * handling. Set the POLLIN bit in this case.
495 	 */
496 	if (exceptions && exceptions->table) {
497 		for (i = 0; i < exceptions->count; i++) {
498 			/*
499 			 * See if we already added this descriptor, just use it
500 			 * if so.
501 			 */
502 			fd = exceptions->table[i].sock;
503 			assert(fd >= 0 && fd < max_pollfd_map);
504 			pfd = pollfds_map[fd];
505 			if (!pfd) {
506 				pfd = &(pollfds[nxt]);
507 				pfd->events = POLLIN;
508 				pfd->fd = fd;
509 				pollfds[i].revents = 0;
510 				pollfds_map[fd] = pfd;
511 				nxt++;
512 			}
513 		}
514 	}
515 
516 	return nxt;
517 }
518 
519 
520 static int eloop_sock_table_dispatch_table(struct eloop_sock_table *table,
521 					   struct pollfd **pollfds_map,
522 					   int max_pollfd_map,
523 					   short int revents)
524 {
525 	size_t i;
526 	struct pollfd *pfd;
527 
528 	if (!table || !table->table)
529 		return 0;
530 
531 	table->changed = 0;
532 	for (i = 0; i < table->count; i++) {
533 		pfd = find_pollfd(pollfds_map, table->table[i].sock,
534 				  max_pollfd_map);
535 		if (!pfd)
536 			continue;
537 
538 		if (!(pfd->revents & revents))
539 			continue;
540 
541 		table->table[i].handler(table->table[i].sock,
542 					table->table[i].eloop_data,
543 					table->table[i].user_data);
544 		if (table->changed)
545 			return 1;
546 	}
547 
548 	return 0;
549 }
550 
551 
552 static void eloop_sock_table_dispatch(struct eloop_sock_table *readers,
553 				      struct eloop_sock_table *writers,
554 				      struct eloop_sock_table *exceptions,
555 				      struct pollfd **pollfds_map,
556 				      int max_pollfd_map)
557 {
558 	if (eloop_sock_table_dispatch_table(readers, pollfds_map,
559 					    max_pollfd_map, POLLIN | POLLERR |
560 					    POLLHUP))
561 		return; /* pollfds may be invalid at this point */
562 
563 	if (eloop_sock_table_dispatch_table(writers, pollfds_map,
564 					    max_pollfd_map, POLLOUT))
565 		return; /* pollfds may be invalid at this point */
566 
567 	eloop_sock_table_dispatch_table(exceptions, pollfds_map,
568 					max_pollfd_map, POLLERR | POLLHUP);
569 }
570 
571 #endif /* CONFIG_ELOOP_POLL */
572 
573 #ifdef CONFIG_ELOOP_SELECT
574 
575 static void eloop_sock_table_set_fds(struct eloop_sock_table *table,
576 				     fd_set *fds)
577 {
578 	size_t i;
579 
580 	FD_ZERO(fds);
581 
582 	if (table->table == NULL)
583 		return;
584 
585 	for (i = 0; i < table->count; i++) {
586 		assert(table->table[i].sock >= 0);
587 		FD_SET(table->table[i].sock, fds);
588 	}
589 }
590 
591 
592 static void eloop_sock_table_dispatch(struct eloop_sock_table *table,
593 				      fd_set *fds)
594 {
595 	size_t i;
596 
597 	if (table == NULL || table->table == NULL)
598 		return;
599 
600 	table->changed = 0;
601 	for (i = 0; i < table->count; i++) {
602 		if (FD_ISSET(table->table[i].sock, fds)) {
603 			table->table[i].handler(table->table[i].sock,
604 						table->table[i].eloop_data,
605 						table->table[i].user_data);
606 			if (table->changed)
607 				break;
608 		}
609 	}
610 }
611 
612 #endif /* CONFIG_ELOOP_SELECT */
613 
614 
615 #ifdef CONFIG_ELOOP_EPOLL
616 static void eloop_sock_table_dispatch(struct epoll_event *events, int nfds)
617 {
618 	struct eloop_sock *table;
619 	int i;
620 
621 	for (i = 0; i < nfds; i++) {
622 		table = &eloop.fd_table[events[i].data.fd];
623 		if (table->handler == NULL)
624 			continue;
625 		table->handler(table->sock, table->eloop_data,
626 			       table->user_data);
627 		if (eloop.readers.changed ||
628 		    eloop.writers.changed ||
629 		    eloop.exceptions.changed)
630 			break;
631 	}
632 }
633 #endif /* CONFIG_ELOOP_EPOLL */
634 
635 
636 #ifdef CONFIG_ELOOP_KQUEUE
637 
638 static void eloop_sock_table_dispatch(struct kevent *events, int nfds)
639 {
640 	struct eloop_sock *table;
641 	int i;
642 
643 	for (i = 0; i < nfds; i++) {
644 		table = &eloop.fd_table[events[i].ident];
645 		if (table->handler == NULL)
646 			continue;
647 		table->handler(table->sock, table->eloop_data,
648 			       table->user_data);
649 		if (eloop.readers.changed ||
650 		    eloop.writers.changed ||
651 		    eloop.exceptions.changed)
652 			break;
653 	}
654 }
655 
656 
657 static int eloop_sock_table_requeue(struct eloop_sock_table *table)
658 {
659 	size_t i;
660 	int r;
661 
662 	r = 0;
663 	for (i = 0; i < table->count && table->table; i++) {
664 		if (eloop_sock_queue(table->table[i].sock, table->type) == -1)
665 			r = -1;
666 	}
667 	return r;
668 }
669 
670 #endif /* CONFIG_ELOOP_KQUEUE */
671 
672 
673 int eloop_sock_requeue(void)
674 {
675 	int r = 0;
676 
677 #ifdef CONFIG_ELOOP_KQUEUE
678 	close(eloop.kqueuefd);
679 	eloop.kqueuefd = kqueue();
680 	if (eloop.kqueuefd < 0) {
681 		wpa_printf(MSG_ERROR, "%s: kqueue failed: %s",
682 			   __func__, strerror(errno));
683 		return -1;
684 	}
685 
686 	if (eloop_sock_table_requeue(&eloop.readers) < 0)
687 		r = -1;
688 	if (eloop_sock_table_requeue(&eloop.writers) < 0)
689 		r = -1;
690 	if (eloop_sock_table_requeue(&eloop.exceptions) < 0)
691 		r = -1;
692 #endif /* CONFIG_ELOOP_KQUEUE */
693 
694 	return r;
695 }
696 
697 
698 static void eloop_sock_table_destroy(struct eloop_sock_table *table)
699 {
700 	if (table) {
701 		size_t i;
702 
703 		for (i = 0; i < table->count && table->table; i++) {
704 			wpa_printf(MSG_INFO, "ELOOP: remaining socket: "
705 				   "sock=%d eloop_data=%p user_data=%p "
706 				   "handler=%p",
707 				   table->table[i].sock,
708 				   table->table[i].eloop_data,
709 				   table->table[i].user_data,
710 				   table->table[i].handler);
711 			wpa_trace_dump_funcname("eloop unregistered socket "
712 						"handler",
713 						table->table[i].handler);
714 			wpa_trace_dump("eloop sock", &table->table[i]);
715 		}
716 		os_free(table->table);
717 	}
718 }
719 
720 
721 int eloop_register_read_sock(int sock, eloop_sock_handler handler,
722 			     void *eloop_data, void *user_data)
723 {
724 	return eloop_register_sock(sock, EVENT_TYPE_READ, handler,
725 				   eloop_data, user_data);
726 }
727 
728 
729 void eloop_unregister_read_sock(int sock)
730 {
731 	eloop_unregister_sock(sock, EVENT_TYPE_READ);
732 }
733 
734 
735 static struct eloop_sock_table *eloop_get_sock_table(eloop_event_type type)
736 {
737 	switch (type) {
738 	case EVENT_TYPE_READ:
739 		return &eloop.readers;
740 	case EVENT_TYPE_WRITE:
741 		return &eloop.writers;
742 	case EVENT_TYPE_EXCEPTION:
743 		return &eloop.exceptions;
744 	}
745 
746 	return NULL;
747 }
748 
749 
750 int eloop_register_sock(int sock, eloop_event_type type,
751 			eloop_sock_handler handler,
752 			void *eloop_data, void *user_data)
753 {
754 	struct eloop_sock_table *table;
755 
756 	assert(sock >= 0);
757 	table = eloop_get_sock_table(type);
758 	return eloop_sock_table_add_sock(table, sock, handler,
759 					 eloop_data, user_data);
760 }
761 
762 
763 void eloop_unregister_sock(int sock, eloop_event_type type)
764 {
765 	struct eloop_sock_table *table;
766 
767 	table = eloop_get_sock_table(type);
768 	eloop_sock_table_remove_sock(table, sock);
769 }
770 
771 
772 int eloop_register_timeout(unsigned int secs, unsigned int usecs,
773 			   eloop_timeout_handler handler,
774 			   void *eloop_data, void *user_data)
775 {
776 	struct eloop_timeout *timeout, *tmp;
777 	os_time_t now_sec;
778 
779 	timeout = os_zalloc(sizeof(*timeout));
780 	if (timeout == NULL)
781 		return -1;
782 	if (os_get_reltime(&timeout->time) < 0) {
783 		os_free(timeout);
784 		return -1;
785 	}
786 	now_sec = timeout->time.sec;
787 	timeout->time.sec += secs;
788 	if (timeout->time.sec < now_sec) {
789 		/*
790 		 * Integer overflow - assume long enough timeout to be assumed
791 		 * to be infinite, i.e., the timeout would never happen.
792 		 */
793 		wpa_printf(MSG_DEBUG, "ELOOP: Too long timeout (secs=%u) to "
794 			   "ever happen - ignore it", secs);
795 		os_free(timeout);
796 		return 0;
797 	}
798 	timeout->time.usec += usecs;
799 	while (timeout->time.usec >= 1000000) {
800 		timeout->time.sec++;
801 		timeout->time.usec -= 1000000;
802 	}
803 	timeout->eloop_data = eloop_data;
804 	timeout->user_data = user_data;
805 	timeout->handler = handler;
806 	wpa_trace_add_ref(timeout, eloop, eloop_data);
807 	wpa_trace_add_ref(timeout, user, user_data);
808 	wpa_trace_record(timeout);
809 
810 	/* Maintain timeouts in order of increasing time */
811 	dl_list_for_each(tmp, &eloop.timeout, struct eloop_timeout, list) {
812 		if (os_reltime_before(&timeout->time, &tmp->time)) {
813 			dl_list_add(tmp->list.prev, &timeout->list);
814 			return 0;
815 		}
816 	}
817 	dl_list_add_tail(&eloop.timeout, &timeout->list);
818 
819 	return 0;
820 }
821 
822 
823 static void eloop_remove_timeout(struct eloop_timeout *timeout)
824 {
825 	dl_list_del(&timeout->list);
826 	wpa_trace_remove_ref(timeout, eloop, timeout->eloop_data);
827 	wpa_trace_remove_ref(timeout, user, timeout->user_data);
828 	os_free(timeout);
829 }
830 
831 
832 int eloop_cancel_timeout(eloop_timeout_handler handler,
833 			 void *eloop_data, void *user_data)
834 {
835 	struct eloop_timeout *timeout, *prev;
836 	int removed = 0;
837 
838 	dl_list_for_each_safe(timeout, prev, &eloop.timeout,
839 			      struct eloop_timeout, list) {
840 		if (timeout->handler == handler &&
841 		    (timeout->eloop_data == eloop_data ||
842 		     eloop_data == ELOOP_ALL_CTX) &&
843 		    (timeout->user_data == user_data ||
844 		     user_data == ELOOP_ALL_CTX)) {
845 			eloop_remove_timeout(timeout);
846 			removed++;
847 		}
848 	}
849 
850 	return removed;
851 }
852 
853 
854 int eloop_cancel_timeout_one(eloop_timeout_handler handler,
855 			     void *eloop_data, void *user_data,
856 			     struct os_reltime *remaining)
857 {
858 	struct eloop_timeout *timeout, *prev;
859 	int removed = 0;
860 	struct os_reltime now;
861 
862 	os_get_reltime(&now);
863 	remaining->sec = remaining->usec = 0;
864 
865 	dl_list_for_each_safe(timeout, prev, &eloop.timeout,
866 			      struct eloop_timeout, list) {
867 		if (timeout->handler == handler &&
868 		    (timeout->eloop_data == eloop_data) &&
869 		    (timeout->user_data == user_data)) {
870 			removed = 1;
871 			if (os_reltime_before(&now, &timeout->time))
872 				os_reltime_sub(&timeout->time, &now, remaining);
873 			eloop_remove_timeout(timeout);
874 			break;
875 		}
876 	}
877 	return removed;
878 }
879 
880 
881 int eloop_is_timeout_registered(eloop_timeout_handler handler,
882 				void *eloop_data, void *user_data)
883 {
884 	struct eloop_timeout *tmp;
885 
886 	dl_list_for_each(tmp, &eloop.timeout, struct eloop_timeout, list) {
887 		if (tmp->handler == handler &&
888 		    tmp->eloop_data == eloop_data &&
889 		    tmp->user_data == user_data)
890 			return 1;
891 	}
892 
893 	return 0;
894 }
895 
896 
897 int eloop_deplete_timeout(unsigned int req_secs, unsigned int req_usecs,
898 			  eloop_timeout_handler handler, void *eloop_data,
899 			  void *user_data)
900 {
901 	struct os_reltime now, requested, remaining;
902 	struct eloop_timeout *tmp;
903 
904 	dl_list_for_each(tmp, &eloop.timeout, struct eloop_timeout, list) {
905 		if (tmp->handler == handler &&
906 		    tmp->eloop_data == eloop_data &&
907 		    tmp->user_data == user_data) {
908 			requested.sec = req_secs;
909 			requested.usec = req_usecs;
910 			os_get_reltime(&now);
911 			os_reltime_sub(&tmp->time, &now, &remaining);
912 			if (os_reltime_before(&requested, &remaining)) {
913 				eloop_cancel_timeout(handler, eloop_data,
914 						     user_data);
915 				eloop_register_timeout(requested.sec,
916 						       requested.usec,
917 						       handler, eloop_data,
918 						       user_data);
919 				return 1;
920 			}
921 			return 0;
922 		}
923 	}
924 
925 	return -1;
926 }
927 
928 
929 int eloop_replenish_timeout(unsigned int req_secs, unsigned int req_usecs,
930 			    eloop_timeout_handler handler, void *eloop_data,
931 			    void *user_data)
932 {
933 	struct os_reltime now, requested, remaining;
934 	struct eloop_timeout *tmp;
935 
936 	dl_list_for_each(tmp, &eloop.timeout, struct eloop_timeout, list) {
937 		if (tmp->handler == handler &&
938 		    tmp->eloop_data == eloop_data &&
939 		    tmp->user_data == user_data) {
940 			requested.sec = req_secs;
941 			requested.usec = req_usecs;
942 			os_get_reltime(&now);
943 			os_reltime_sub(&tmp->time, &now, &remaining);
944 			if (os_reltime_before(&remaining, &requested)) {
945 				eloop_cancel_timeout(handler, eloop_data,
946 						     user_data);
947 				eloop_register_timeout(requested.sec,
948 						       requested.usec,
949 						       handler, eloop_data,
950 						       user_data);
951 				return 1;
952 			}
953 			return 0;
954 		}
955 	}
956 
957 	return -1;
958 }
959 
960 
961 #ifndef CONFIG_NATIVE_WINDOWS
962 static void eloop_handle_alarm(int sig)
963 {
964 	wpa_printf(MSG_ERROR, "eloop: could not process SIGINT or SIGTERM in "
965 		   "two seconds. Looks like there\n"
966 		   "is a bug that ends up in a busy loop that "
967 		   "prevents clean shutdown.\n"
968 		   "Killing program forcefully.\n");
969 	exit(1);
970 }
971 #endif /* CONFIG_NATIVE_WINDOWS */
972 
973 
974 static void eloop_handle_signal(int sig)
975 {
976 	size_t i;
977 
978 #ifndef CONFIG_NATIVE_WINDOWS
979 	if ((sig == SIGINT || sig == SIGTERM) && !eloop.pending_terminate) {
980 		/* Use SIGALRM to break out from potential busy loops that
981 		 * would not allow the program to be killed. */
982 		eloop.pending_terminate = 1;
983 		signal(SIGALRM, eloop_handle_alarm);
984 		alarm(2);
985 	}
986 #endif /* CONFIG_NATIVE_WINDOWS */
987 
988 	eloop.signaled++;
989 	for (i = 0; i < eloop.signal_count; i++) {
990 		if (eloop.signals[i].sig == sig) {
991 			eloop.signals[i].signaled++;
992 			break;
993 		}
994 	}
995 }
996 
997 
998 static void eloop_process_pending_signals(void)
999 {
1000 	size_t i;
1001 
1002 	if (eloop.signaled == 0)
1003 		return;
1004 	eloop.signaled = 0;
1005 
1006 	if (eloop.pending_terminate) {
1007 #ifndef CONFIG_NATIVE_WINDOWS
1008 		alarm(0);
1009 #endif /* CONFIG_NATIVE_WINDOWS */
1010 		eloop.pending_terminate = 0;
1011 	}
1012 
1013 	for (i = 0; i < eloop.signal_count; i++) {
1014 		if (eloop.signals[i].signaled) {
1015 			eloop.signals[i].signaled = 0;
1016 			eloop.signals[i].handler(eloop.signals[i].sig,
1017 						 eloop.signals[i].user_data);
1018 		}
1019 	}
1020 }
1021 
1022 
1023 int eloop_register_signal(int sig, eloop_signal_handler handler,
1024 			  void *user_data)
1025 {
1026 	struct eloop_signal *tmp;
1027 
1028 	tmp = os_realloc_array(eloop.signals, eloop.signal_count + 1,
1029 			       sizeof(struct eloop_signal));
1030 	if (tmp == NULL)
1031 		return -1;
1032 
1033 	tmp[eloop.signal_count].sig = sig;
1034 	tmp[eloop.signal_count].user_data = user_data;
1035 	tmp[eloop.signal_count].handler = handler;
1036 	tmp[eloop.signal_count].signaled = 0;
1037 	eloop.signal_count++;
1038 	eloop.signals = tmp;
1039 	signal(sig, eloop_handle_signal);
1040 
1041 	return 0;
1042 }
1043 
1044 
1045 int eloop_register_signal_terminate(eloop_signal_handler handler,
1046 				    void *user_data)
1047 {
1048 	int ret = eloop_register_signal(SIGINT, handler, user_data);
1049 	if (ret == 0)
1050 		ret = eloop_register_signal(SIGTERM, handler, user_data);
1051 	return ret;
1052 }
1053 
1054 
1055 int eloop_register_signal_reconfig(eloop_signal_handler handler,
1056 				   void *user_data)
1057 {
1058 #ifdef CONFIG_NATIVE_WINDOWS
1059 	return 0;
1060 #else /* CONFIG_NATIVE_WINDOWS */
1061 	return eloop_register_signal(SIGHUP, handler, user_data);
1062 #endif /* CONFIG_NATIVE_WINDOWS */
1063 }
1064 
1065 
1066 void eloop_run(void)
1067 {
1068 #ifdef CONFIG_ELOOP_POLL
1069 	int num_poll_fds;
1070 	int timeout_ms = 0;
1071 #endif /* CONFIG_ELOOP_POLL */
1072 #ifdef CONFIG_ELOOP_SELECT
1073 	fd_set *rfds, *wfds, *efds;
1074 	struct timeval _tv;
1075 #endif /* CONFIG_ELOOP_SELECT */
1076 #ifdef CONFIG_ELOOP_EPOLL
1077 	int timeout_ms = -1;
1078 #endif /* CONFIG_ELOOP_EPOLL */
1079 #ifdef CONFIG_ELOOP_KQUEUE
1080 	struct timespec ts;
1081 #endif /* CONFIG_ELOOP_KQUEUE */
1082 	int res;
1083 	struct os_reltime tv, now;
1084 
1085 #ifdef CONFIG_ELOOP_SELECT
1086 	rfds = os_malloc(sizeof(*rfds));
1087 	wfds = os_malloc(sizeof(*wfds));
1088 	efds = os_malloc(sizeof(*efds));
1089 	if (rfds == NULL || wfds == NULL || efds == NULL)
1090 		goto out;
1091 #endif /* CONFIG_ELOOP_SELECT */
1092 
1093 	while (!eloop.terminate &&
1094 	       (!dl_list_empty(&eloop.timeout) || eloop.readers.count > 0 ||
1095 		eloop.writers.count > 0 || eloop.exceptions.count > 0)) {
1096 		struct eloop_timeout *timeout;
1097 
1098 		if (eloop.pending_terminate) {
1099 			/*
1100 			 * This may happen in some corner cases where a signal
1101 			 * is received during a blocking operation. We need to
1102 			 * process the pending signals and exit if requested to
1103 			 * avoid hitting the SIGALRM limit if the blocking
1104 			 * operation took more than two seconds.
1105 			 */
1106 			eloop_process_pending_signals();
1107 			if (eloop.terminate)
1108 				break;
1109 		}
1110 
1111 		timeout = dl_list_first(&eloop.timeout, struct eloop_timeout,
1112 					list);
1113 		if (timeout) {
1114 			os_get_reltime(&now);
1115 			if (os_reltime_before(&now, &timeout->time))
1116 				os_reltime_sub(&timeout->time, &now, &tv);
1117 			else
1118 				tv.sec = tv.usec = 0;
1119 #if defined(CONFIG_ELOOP_POLL) || defined(CONFIG_ELOOP_EPOLL)
1120 			timeout_ms = tv.sec * 1000 + tv.usec / 1000;
1121 #endif /* defined(CONFIG_ELOOP_POLL) || defined(CONFIG_ELOOP_EPOLL) */
1122 #ifdef CONFIG_ELOOP_SELECT
1123 			_tv.tv_sec = tv.sec;
1124 			_tv.tv_usec = tv.usec;
1125 #endif /* CONFIG_ELOOP_SELECT */
1126 #ifdef CONFIG_ELOOP_KQUEUE
1127 			ts.tv_sec = tv.sec;
1128 			ts.tv_nsec = tv.usec * 1000L;
1129 #endif /* CONFIG_ELOOP_KQUEUE */
1130 		}
1131 
1132 #ifdef CONFIG_ELOOP_POLL
1133 		num_poll_fds = eloop_sock_table_set_fds(
1134 			&eloop.readers, &eloop.writers, &eloop.exceptions,
1135 			eloop.pollfds, eloop.pollfds_map,
1136 			eloop.max_pollfd_map);
1137 		res = poll(eloop.pollfds, num_poll_fds,
1138 			   timeout ? timeout_ms : -1);
1139 #endif /* CONFIG_ELOOP_POLL */
1140 #ifdef CONFIG_ELOOP_SELECT
1141 		eloop_sock_table_set_fds(&eloop.readers, rfds);
1142 		eloop_sock_table_set_fds(&eloop.writers, wfds);
1143 		eloop_sock_table_set_fds(&eloop.exceptions, efds);
1144 		res = select(eloop.max_sock + 1, rfds, wfds, efds,
1145 			     timeout ? &_tv : NULL);
1146 #endif /* CONFIG_ELOOP_SELECT */
1147 #ifdef CONFIG_ELOOP_EPOLL
1148 		if (eloop.count == 0) {
1149 			res = 0;
1150 		} else {
1151 			res = epoll_wait(eloop.epollfd, eloop.epoll_events,
1152 					 eloop.count, timeout_ms);
1153 		}
1154 #endif /* CONFIG_ELOOP_EPOLL */
1155 #ifdef CONFIG_ELOOP_KQUEUE
1156 		if (eloop.count == 0) {
1157 			res = 0;
1158 		} else {
1159 			res = kevent(eloop.kqueuefd, NULL, 0,
1160 				     eloop.kqueue_events, eloop.kqueue_nevents,
1161 				     timeout ? &ts : NULL);
1162 		}
1163 #endif /* CONFIG_ELOOP_KQUEUE */
1164 		if (res < 0 && errno != EINTR && errno != 0) {
1165 			wpa_printf(MSG_ERROR, "eloop: %s: %s",
1166 #ifdef CONFIG_ELOOP_POLL
1167 				   "poll"
1168 #endif /* CONFIG_ELOOP_POLL */
1169 #ifdef CONFIG_ELOOP_SELECT
1170 				   "select"
1171 #endif /* CONFIG_ELOOP_SELECT */
1172 #ifdef CONFIG_ELOOP_EPOLL
1173 				   "epoll"
1174 #endif /* CONFIG_ELOOP_EPOLL */
1175 #ifdef CONFIG_ELOOP_KQUEUE
1176 				   "kqueue"
1177 #endif /* CONFIG_ELOOP_EKQUEUE */
1178 
1179 				   , strerror(errno));
1180 			goto out;
1181 		}
1182 
1183 		eloop.readers.changed = 0;
1184 		eloop.writers.changed = 0;
1185 		eloop.exceptions.changed = 0;
1186 
1187 		eloop_process_pending_signals();
1188 
1189 
1190 		/* check if some registered timeouts have occurred */
1191 		timeout = dl_list_first(&eloop.timeout, struct eloop_timeout,
1192 					list);
1193 		if (timeout) {
1194 			os_get_reltime(&now);
1195 			if (!os_reltime_before(&now, &timeout->time)) {
1196 				void *eloop_data = timeout->eloop_data;
1197 				void *user_data = timeout->user_data;
1198 				eloop_timeout_handler handler =
1199 					timeout->handler;
1200 				eloop_remove_timeout(timeout);
1201 				handler(eloop_data, user_data);
1202 			}
1203 
1204 		}
1205 
1206 		if (res <= 0)
1207 			continue;
1208 
1209 		if (eloop.readers.changed ||
1210 		    eloop.writers.changed ||
1211 		    eloop.exceptions.changed) {
1212 			 /*
1213 			  * Sockets may have been closed and reopened with the
1214 			  * same FD in the signal or timeout handlers, so we
1215 			  * must skip the previous results and check again
1216 			  * whether any of the currently registered sockets have
1217 			  * events.
1218 			  */
1219 			continue;
1220 		}
1221 
1222 #ifdef CONFIG_ELOOP_POLL
1223 		eloop_sock_table_dispatch(&eloop.readers, &eloop.writers,
1224 					  &eloop.exceptions, eloop.pollfds_map,
1225 					  eloop.max_pollfd_map);
1226 #endif /* CONFIG_ELOOP_POLL */
1227 #ifdef CONFIG_ELOOP_SELECT
1228 		eloop_sock_table_dispatch(&eloop.readers, rfds);
1229 		eloop_sock_table_dispatch(&eloop.writers, wfds);
1230 		eloop_sock_table_dispatch(&eloop.exceptions, efds);
1231 #endif /* CONFIG_ELOOP_SELECT */
1232 #ifdef CONFIG_ELOOP_EPOLL
1233 		eloop_sock_table_dispatch(eloop.epoll_events, res);
1234 #endif /* CONFIG_ELOOP_EPOLL */
1235 #ifdef CONFIG_ELOOP_KQUEUE
1236 		eloop_sock_table_dispatch(eloop.kqueue_events, res);
1237 #endif /* CONFIG_ELOOP_KQUEUE */
1238 	}
1239 
1240 	eloop.terminate = 0;
1241 out:
1242 #ifdef CONFIG_ELOOP_SELECT
1243 	os_free(rfds);
1244 	os_free(wfds);
1245 	os_free(efds);
1246 #endif /* CONFIG_ELOOP_SELECT */
1247 	return;
1248 }
1249 
1250 
1251 void eloop_terminate(void)
1252 {
1253 	eloop.terminate = 1;
1254 }
1255 
1256 
1257 void eloop_destroy(void)
1258 {
1259 	struct eloop_timeout *timeout, *prev;
1260 	struct os_reltime now;
1261 
1262 	os_get_reltime(&now);
1263 	dl_list_for_each_safe(timeout, prev, &eloop.timeout,
1264 			      struct eloop_timeout, list) {
1265 		int sec, usec;
1266 		sec = timeout->time.sec - now.sec;
1267 		usec = timeout->time.usec - now.usec;
1268 		if (timeout->time.usec < now.usec) {
1269 			sec--;
1270 			usec += 1000000;
1271 		}
1272 		wpa_printf(MSG_INFO, "ELOOP: remaining timeout: %d.%06d "
1273 			   "eloop_data=%p user_data=%p handler=%p",
1274 			   sec, usec, timeout->eloop_data, timeout->user_data,
1275 			   timeout->handler);
1276 		wpa_trace_dump_funcname("eloop unregistered timeout handler",
1277 					timeout->handler);
1278 		wpa_trace_dump("eloop timeout", timeout);
1279 		eloop_remove_timeout(timeout);
1280 	}
1281 	eloop_sock_table_destroy(&eloop.readers);
1282 	eloop_sock_table_destroy(&eloop.writers);
1283 	eloop_sock_table_destroy(&eloop.exceptions);
1284 	os_free(eloop.signals);
1285 
1286 #ifdef CONFIG_ELOOP_POLL
1287 	os_free(eloop.pollfds);
1288 	os_free(eloop.pollfds_map);
1289 #endif /* CONFIG_ELOOP_POLL */
1290 #if defined(CONFIG_ELOOP_EPOLL) || defined(CONFIG_ELOOP_KQUEUE)
1291 	os_free(eloop.fd_table);
1292 #endif /* CONFIG_ELOOP_EPOLL || CONFIG_ELOOP_KQUEUE */
1293 #ifdef CONFIG_ELOOP_EPOLL
1294 	os_free(eloop.epoll_events);
1295 	close(eloop.epollfd);
1296 #endif /* CONFIG_ELOOP_EPOLL */
1297 #ifdef CONFIG_ELOOP_KQUEUE
1298 	os_free(eloop.kqueue_events);
1299 	close(eloop.kqueuefd);
1300 #endif /* CONFIG_ELOOP_KQUEUE */
1301 }
1302 
1303 
1304 int eloop_terminated(void)
1305 {
1306 	return eloop.terminate || eloop.pending_terminate;
1307 }
1308 
1309 
1310 void eloop_wait_for_read_sock(int sock)
1311 {
1312 #ifdef CONFIG_ELOOP_POLL
1313 	struct pollfd pfd;
1314 
1315 	if (sock < 0)
1316 		return;
1317 
1318 	os_memset(&pfd, 0, sizeof(pfd));
1319 	pfd.fd = sock;
1320 	pfd.events = POLLIN;
1321 
1322 	poll(&pfd, 1, -1);
1323 #endif /* CONFIG_ELOOP_POLL */
1324 #if defined(CONFIG_ELOOP_SELECT) || defined(CONFIG_ELOOP_EPOLL)
1325 	/*
1326 	 * We can use epoll() here. But epoll() requres 4 system calls.
1327 	 * epoll_create1(), epoll_ctl() for ADD, epoll_wait, and close() for
1328 	 * epoll fd. So select() is better for performance here.
1329 	 */
1330 	fd_set rfds;
1331 
1332 	if (sock < 0)
1333 		return;
1334 
1335 	FD_ZERO(&rfds);
1336 	FD_SET(sock, &rfds);
1337 	select(sock + 1, &rfds, NULL, NULL, NULL);
1338 #endif /* defined(CONFIG_ELOOP_SELECT) || defined(CONFIG_ELOOP_EPOLL) */
1339 #ifdef CONFIG_ELOOP_KQUEUE
1340 	int kfd;
1341 	struct kevent ke1, ke2;
1342 
1343 	kfd = kqueue();
1344 	if (kfd == -1)
1345 		return;
1346 	EV_SET(&ke1, sock, EVFILT_READ, EV_ADD | EV_ONESHOT, 0, 0, 0);
1347 	kevent(kfd, &ke1, 1, &ke2, 1, NULL);
1348 	close(kfd);
1349 #endif /* CONFIG_ELOOP_KQUEUE */
1350 }
1351 
1352 #ifdef CONFIG_ELOOP_SELECT
1353 #undef CONFIG_ELOOP_SELECT
1354 #endif /* CONFIG_ELOOP_SELECT */
1355