xref: /freebsd/contrib/unbound/util/tube.c (revision c07d6445eb89d9dd3950361b065b7bd110e3a043)
1 /*
2  * util/tube.c - pipe service
3  *
4  * Copyright (c) 2008, NLnet Labs. All rights reserved.
5  *
6  * This software is open source.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * Redistributions of source code must retain the above copyright notice,
13  * this list of conditions and the following disclaimer.
14  *
15  * Redistributions in binary form must reproduce the above copyright notice,
16  * this list of conditions and the following disclaimer in the documentation
17  * and/or other materials provided with the distribution.
18  *
19  * Neither the name of the NLNET LABS nor the names of its contributors may
20  * be used to endorse or promote products derived from this software without
21  * specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /**
37  * \file
38  *
39  * This file contains pipe service functions.
40  */
41 #include "config.h"
42 #include "util/tube.h"
43 #include "util/log.h"
44 #include "util/net_help.h"
45 #include "util/netevent.h"
46 #include "util/fptr_wlist.h"
47 #include "util/ub_event.h"
48 
49 #ifndef USE_WINSOCK
50 /* on unix */
51 
52 #ifndef HAVE_SOCKETPAIR
53 /** no socketpair() available, like on Minix 3.1.7, use pipe */
54 #define socketpair(f, t, p, sv) pipe(sv)
55 #endif /* HAVE_SOCKETPAIR */
56 
57 struct tube* tube_create(void)
58 {
59 	struct tube* tube = (struct tube*)calloc(1, sizeof(*tube));
60 	int sv[2];
61 	if(!tube) {
62 		int err = errno;
63 		log_err("tube_create: out of memory");
64 		errno = err;
65 		return NULL;
66 	}
67 	tube->sr = -1;
68 	tube->sw = -1;
69 	if(socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == -1) {
70 		int err = errno;
71 		log_err("socketpair: %s", strerror(errno));
72 		free(tube);
73 		errno = err;
74 		return NULL;
75 	}
76 	tube->sr = sv[0];
77 	tube->sw = sv[1];
78 	if(!fd_set_nonblock(tube->sr) || !fd_set_nonblock(tube->sw)) {
79 		int err = errno;
80 		log_err("tube: cannot set nonblocking");
81 		tube_delete(tube);
82 		errno = err;
83 		return NULL;
84 	}
85 	return tube;
86 }
87 
88 void tube_delete(struct tube* tube)
89 {
90 	if(!tube) return;
91 	tube_remove_bg_listen(tube);
92 	tube_remove_bg_write(tube);
93 	/* close fds after deleting commpoints, to be sure.
94 	 *            Also epoll does not like closing fd before event_del */
95 	tube_close_read(tube);
96 	tube_close_write(tube);
97 	free(tube);
98 }
99 
100 void tube_close_read(struct tube* tube)
101 {
102 	if(tube->sr != -1) {
103 		close(tube->sr);
104 		tube->sr = -1;
105 	}
106 }
107 
108 void tube_close_write(struct tube* tube)
109 {
110 	if(tube->sw != -1) {
111 		close(tube->sw);
112 		tube->sw = -1;
113 	}
114 }
115 
116 void tube_remove_bg_listen(struct tube* tube)
117 {
118 	if(tube->listen_com) {
119 		comm_point_delete(tube->listen_com);
120 		tube->listen_com = NULL;
121 	}
122 	free(tube->cmd_msg);
123 	tube->cmd_msg = NULL;
124 }
125 
126 void tube_remove_bg_write(struct tube* tube)
127 {
128 	if(tube->res_com) {
129 		comm_point_delete(tube->res_com);
130 		tube->res_com = NULL;
131 	}
132 	if(tube->res_list) {
133 		struct tube_res_list* np, *p = tube->res_list;
134 		tube->res_list = NULL;
135 		tube->res_last = NULL;
136 		while(p) {
137 			np = p->next;
138 			free(p->buf);
139 			free(p);
140 			p = np;
141 		}
142 	}
143 }
144 
145 int
146 tube_handle_listen(struct comm_point* c, void* arg, int error,
147         struct comm_reply* ATTR_UNUSED(reply_info))
148 {
149 	struct tube* tube = (struct tube*)arg;
150 	ssize_t r;
151 	if(error != NETEVENT_NOERROR) {
152 		fptr_ok(fptr_whitelist_tube_listen(tube->listen_cb));
153 		(*tube->listen_cb)(tube, NULL, 0, error, tube->listen_arg);
154 		return 0;
155 	}
156 
157 	if(tube->cmd_read < sizeof(tube->cmd_len)) {
158 		/* complete reading the length of control msg */
159 		r = read(c->fd, ((uint8_t*)&tube->cmd_len) + tube->cmd_read,
160 			sizeof(tube->cmd_len) - tube->cmd_read);
161 		if(r==0) {
162 			/* error has happened or */
163 			/* parent closed pipe, must have exited somehow */
164 			fptr_ok(fptr_whitelist_tube_listen(tube->listen_cb));
165 			(*tube->listen_cb)(tube, NULL, 0, NETEVENT_CLOSED,
166 				tube->listen_arg);
167 			return 0;
168 		}
169 		if(r==-1) {
170 			if(errno != EAGAIN && errno != EINTR) {
171 				log_err("rpipe error: %s", strerror(errno));
172 			}
173 			/* nothing to read now, try later */
174 			return 0;
175 		}
176 		tube->cmd_read += r;
177 		if(tube->cmd_read < sizeof(tube->cmd_len)) {
178 			/* not complete, try later */
179 			return 0;
180 		}
181 		tube->cmd_msg = (uint8_t*)calloc(1, tube->cmd_len);
182 		if(!tube->cmd_msg) {
183 			log_err("malloc failure");
184 			tube->cmd_read = 0;
185 			return 0;
186 		}
187 	}
188 	/* cmd_len has been read, read remainder */
189 	r = read(c->fd, tube->cmd_msg+tube->cmd_read-sizeof(tube->cmd_len),
190 		tube->cmd_len - (tube->cmd_read - sizeof(tube->cmd_len)));
191 	if(r==0) {
192 		/* error has happened or */
193 		/* parent closed pipe, must have exited somehow */
194 		fptr_ok(fptr_whitelist_tube_listen(tube->listen_cb));
195 		(*tube->listen_cb)(tube, NULL, 0, NETEVENT_CLOSED,
196 			tube->listen_arg);
197 		return 0;
198 	}
199 	if(r==-1) {
200 		/* nothing to read now, try later */
201 		if(errno != EAGAIN && errno != EINTR) {
202 			log_err("rpipe error: %s", strerror(errno));
203 		}
204 		return 0;
205 	}
206 	tube->cmd_read += r;
207 	if(tube->cmd_read < sizeof(tube->cmd_len) + tube->cmd_len) {
208 		/* not complete, try later */
209 		return 0;
210 	}
211 	tube->cmd_read = 0;
212 
213 	fptr_ok(fptr_whitelist_tube_listen(tube->listen_cb));
214 	(*tube->listen_cb)(tube, tube->cmd_msg, tube->cmd_len,
215 		NETEVENT_NOERROR, tube->listen_arg);
216 		/* also frees the buf */
217 	tube->cmd_msg = NULL;
218 	return 0;
219 }
220 
221 int
222 tube_handle_write(struct comm_point* c, void* arg, int error,
223         struct comm_reply* ATTR_UNUSED(reply_info))
224 {
225 	struct tube* tube = (struct tube*)arg;
226 	struct tube_res_list* item = tube->res_list;
227 	ssize_t r;
228 	if(error != NETEVENT_NOERROR) {
229 		log_err("tube_handle_write net error %d", error);
230 		return 0;
231 	}
232 
233 	if(!item) {
234 		comm_point_stop_listening(c);
235 		return 0;
236 	}
237 
238 	if(tube->res_write < sizeof(item->len)) {
239 		r = write(c->fd, ((uint8_t*)&item->len) + tube->res_write,
240 			sizeof(item->len) - tube->res_write);
241 		if(r == -1) {
242 			if(errno != EAGAIN && errno != EINTR) {
243 				log_err("wpipe error: %s", strerror(errno));
244 			}
245 			return 0; /* try again later */
246 		}
247 		if(r == 0) {
248 			/* error on pipe, must have exited somehow */
249 			/* cannot signal this to pipe user */
250 			return 0;
251 		}
252 		tube->res_write += r;
253 		if(tube->res_write < sizeof(item->len))
254 			return 0;
255 	}
256 	r = write(c->fd, item->buf + tube->res_write - sizeof(item->len),
257 		item->len - (tube->res_write - sizeof(item->len)));
258 	if(r == -1) {
259 		if(errno != EAGAIN && errno != EINTR) {
260 			log_err("wpipe error: %s", strerror(errno));
261 		}
262 		return 0; /* try again later */
263 	}
264 	if(r == 0) {
265 		/* error on pipe, must have exited somehow */
266 		/* cannot signal this to pipe user */
267 		return 0;
268 	}
269 	tube->res_write += r;
270 	if(tube->res_write < sizeof(item->len) + item->len)
271 		return 0;
272 	/* done this result, remove it */
273 	free(item->buf);
274 	item->buf = NULL;
275 	tube->res_list = tube->res_list->next;
276 	free(item);
277 	if(!tube->res_list) {
278 		tube->res_last = NULL;
279 		comm_point_stop_listening(c);
280 	}
281 	tube->res_write = 0;
282 	return 0;
283 }
284 
285 int tube_write_msg(struct tube* tube, uint8_t* buf, uint32_t len,
286         int nonblock)
287 {
288 	ssize_t r, d;
289 	int fd = tube->sw;
290 
291 	/* test */
292 	if(nonblock) {
293 		r = write(fd, &len, sizeof(len));
294 		if(r == -1) {
295 			if(errno==EINTR || errno==EAGAIN)
296 				return -1;
297 			log_err("tube msg write failed: %s", strerror(errno));
298 			return -1; /* can still continue, perhaps */
299 		}
300 	} else r = 0;
301 	if(!fd_set_block(fd))
302 		return 0;
303 	/* write remainder */
304 	d = r;
305 	while(d != (ssize_t)sizeof(len)) {
306 		if((r=write(fd, ((char*)&len)+d, sizeof(len)-d)) == -1) {
307 			if(errno == EAGAIN)
308 				continue; /* temporarily unavail: try again*/
309 			log_err("tube msg write failed: %s", strerror(errno));
310 			(void)fd_set_nonblock(fd);
311 			return 0;
312 		}
313 		d += r;
314 	}
315 	d = 0;
316 	while(d != (ssize_t)len) {
317 		if((r=write(fd, buf+d, len-d)) == -1) {
318 			if(errno == EAGAIN)
319 				continue; /* temporarily unavail: try again*/
320 			log_err("tube msg write failed: %s", strerror(errno));
321 			(void)fd_set_nonblock(fd);
322 			return 0;
323 		}
324 		d += r;
325 	}
326 	if(!fd_set_nonblock(fd))
327 		return 0;
328 	return 1;
329 }
330 
331 int tube_read_msg(struct tube* tube, uint8_t** buf, uint32_t* len,
332         int nonblock)
333 {
334 	ssize_t r, d;
335 	int fd = tube->sr;
336 
337 	/* test */
338 	*len = 0;
339 	if(nonblock) {
340 		r = read(fd, len, sizeof(*len));
341 		if(r == -1) {
342 			if(errno==EINTR || errno==EAGAIN)
343 				return -1;
344 			log_err("tube msg read failed: %s", strerror(errno));
345 			return -1; /* we can still continue, perhaps */
346 		}
347 		if(r == 0) /* EOF */
348 			return 0;
349 	} else r = 0;
350 	if(!fd_set_block(fd))
351 		return 0;
352 	/* read remainder */
353 	d = r;
354 	while(d != (ssize_t)sizeof(*len)) {
355 		if((r=read(fd, ((char*)len)+d, sizeof(*len)-d)) == -1) {
356 			log_err("tube msg read failed: %s", strerror(errno));
357 			(void)fd_set_nonblock(fd);
358 			return 0;
359 		}
360 		if(r == 0) /* EOF */ {
361 			(void)fd_set_nonblock(fd);
362 			return 0;
363 		}
364 		d += r;
365 	}
366 	if (*len >= 65536*2) {
367 		log_err("tube msg length %u is too big", (unsigned)*len);
368 		(void)fd_set_nonblock(fd);
369 		return 0;
370 	}
371 	*buf = (uint8_t*)malloc(*len);
372 	if(!*buf) {
373 		log_err("tube read out of memory");
374 		(void)fd_set_nonblock(fd);
375 		return 0;
376 	}
377 	d = 0;
378 	while(d < (ssize_t)*len) {
379 		if((r=read(fd, (*buf)+d, (size_t)((ssize_t)*len)-d)) == -1) {
380 			log_err("tube msg read failed: %s", strerror(errno));
381 			(void)fd_set_nonblock(fd);
382 			free(*buf);
383 			return 0;
384 		}
385 		if(r == 0) { /* EOF */
386 			(void)fd_set_nonblock(fd);
387 			free(*buf);
388 			return 0;
389 		}
390 		d += r;
391 	}
392 	if(!fd_set_nonblock(fd)) {
393 		free(*buf);
394 		return 0;
395 	}
396 	return 1;
397 }
398 
399 /** perform a select() on the fd */
400 static int
401 pollit(int fd, struct timeval* t)
402 {
403 	fd_set r;
404 #ifndef S_SPLINT_S
405 	FD_ZERO(&r);
406 	FD_SET(FD_SET_T fd, &r);
407 #endif
408 	if(select(fd+1, &r, NULL, NULL, t) == -1) {
409 		return 0;
410 	}
411 	errno = 0;
412 	return (int)(FD_ISSET(fd, &r));
413 }
414 
415 int tube_poll(struct tube* tube)
416 {
417 	struct timeval t;
418 	memset(&t, 0, sizeof(t));
419 	return pollit(tube->sr, &t);
420 }
421 
422 int tube_wait(struct tube* tube)
423 {
424 	return pollit(tube->sr, NULL);
425 }
426 
427 int tube_wait_timeout(struct tube* tube, int msec)
428 {
429 	struct timeval t;
430 	int fd = tube->sr;
431 	fd_set r;
432 	t.tv_sec = msec/1000;
433 	t.tv_usec = (msec%1000)*1000;
434 #ifndef S_SPLINT_S
435 	FD_ZERO(&r);
436 	FD_SET(FD_SET_T fd, &r);
437 #endif
438 	while(1) {
439 		if(select(fd+1, &r, NULL, NULL, &t) == -1) {
440 			if(errno == EAGAIN || errno == EINTR)
441 				continue;
442 			return -1;
443 		}
444 		break;
445 	}
446 	return (int)(FD_ISSET(fd, &r));
447 }
448 
449 int tube_read_fd(struct tube* tube)
450 {
451 	return tube->sr;
452 }
453 
454 int tube_setup_bg_listen(struct tube* tube, struct comm_base* base,
455         tube_callback_type* cb, void* arg)
456 {
457 	tube->listen_cb = cb;
458 	tube->listen_arg = arg;
459 	if(!(tube->listen_com = comm_point_create_raw(base, tube->sr,
460 		0, tube_handle_listen, tube))) {
461 		int err = errno;
462 		log_err("tube_setup_bg_l: commpoint creation failed");
463 		errno = err;
464 		return 0;
465 	}
466 	return 1;
467 }
468 
469 int tube_setup_bg_write(struct tube* tube, struct comm_base* base)
470 {
471 	if(!(tube->res_com = comm_point_create_raw(base, tube->sw,
472 		1, tube_handle_write, tube))) {
473 		int err = errno;
474 		log_err("tube_setup_bg_w: commpoint creation failed");
475 		errno = err;
476 		return 0;
477 	}
478 	return 1;
479 }
480 
481 int tube_queue_item(struct tube* tube, uint8_t* msg, size_t len)
482 {
483 	struct tube_res_list* item;
484 	if(!tube || !tube->res_com) return 0;
485 	item = (struct tube_res_list*)malloc(sizeof(*item));
486 	if(!item) {
487 		free(msg);
488 		log_err("out of memory for async answer");
489 		return 0;
490 	}
491 	item->buf = msg;
492 	item->len = len;
493 	item->next = NULL;
494 	/* add at back of list, since the first one may be partially written */
495 	if(tube->res_last)
496 		tube->res_last->next = item;
497 	else    tube->res_list = item;
498 	tube->res_last = item;
499 	if(tube->res_list == tube->res_last) {
500 		/* first added item, start the write process */
501 		comm_point_start_listening(tube->res_com, -1, -1);
502 	}
503 	return 1;
504 }
505 
506 void tube_handle_signal(int ATTR_UNUSED(fd), short ATTR_UNUSED(events),
507 	void* ATTR_UNUSED(arg))
508 {
509 	log_assert(0);
510 }
511 
512 #else /* USE_WINSOCK */
513 /* on windows */
514 
515 
516 struct tube* tube_create(void)
517 {
518 	/* windows does not have forks like unix, so we only support
519 	 * threads on windows. And thus the pipe need only connect
520 	 * threads. We use a mutex and a list of datagrams. */
521 	struct tube* tube = (struct tube*)calloc(1, sizeof(*tube));
522 	if(!tube) {
523 		int err = errno;
524 		log_err("tube_create: out of memory");
525 		errno = err;
526 		return NULL;
527 	}
528 	tube->event = WSACreateEvent();
529 	if(tube->event == WSA_INVALID_EVENT) {
530 		free(tube);
531 		log_err("WSACreateEvent: %s", wsa_strerror(WSAGetLastError()));
532 	}
533 	if(!WSAResetEvent(tube->event)) {
534 		log_err("WSAResetEvent: %s", wsa_strerror(WSAGetLastError()));
535 	}
536 	lock_basic_init(&tube->res_lock);
537 	verbose(VERB_ALGO, "tube created");
538 	return tube;
539 }
540 
541 void tube_delete(struct tube* tube)
542 {
543 	if(!tube) return;
544 	tube_remove_bg_listen(tube);
545 	tube_remove_bg_write(tube);
546 	tube_close_read(tube);
547 	tube_close_write(tube);
548 	if(!WSACloseEvent(tube->event))
549 		log_err("WSACloseEvent: %s", wsa_strerror(WSAGetLastError()));
550 	lock_basic_destroy(&tube->res_lock);
551 	verbose(VERB_ALGO, "tube deleted");
552 	free(tube);
553 }
554 
555 void tube_close_read(struct tube* ATTR_UNUSED(tube))
556 {
557 	verbose(VERB_ALGO, "tube close_read");
558 }
559 
560 void tube_close_write(struct tube* ATTR_UNUSED(tube))
561 {
562 	verbose(VERB_ALGO, "tube close_write");
563 	/* wake up waiting reader with an empty queue */
564 	if(!WSASetEvent(tube->event)) {
565 		log_err("WSASetEvent: %s", wsa_strerror(WSAGetLastError()));
566 	}
567 }
568 
569 void tube_remove_bg_listen(struct tube* tube)
570 {
571 	verbose(VERB_ALGO, "tube remove_bg_listen");
572 	ub_winsock_unregister_wsaevent(tube->ev_listen);
573 }
574 
575 void tube_remove_bg_write(struct tube* tube)
576 {
577 	verbose(VERB_ALGO, "tube remove_bg_write");
578 	if(tube->res_list) {
579 		struct tube_res_list* np, *p = tube->res_list;
580 		tube->res_list = NULL;
581 		tube->res_last = NULL;
582 		while(p) {
583 			np = p->next;
584 			free(p->buf);
585 			free(p);
586 			p = np;
587 		}
588 	}
589 }
590 
591 int tube_write_msg(struct tube* tube, uint8_t* buf, uint32_t len,
592         int ATTR_UNUSED(nonblock))
593 {
594 	uint8_t* a;
595 	verbose(VERB_ALGO, "tube write_msg len %d", (int)len);
596 	a = (uint8_t*)memdup(buf, len);
597 	if(!a) {
598 		log_err("out of memory in tube_write_msg");
599 		return 0;
600 	}
601 	/* always nonblocking, this pipe cannot get full */
602 	return tube_queue_item(tube, a, len);
603 }
604 
605 int tube_read_msg(struct tube* tube, uint8_t** buf, uint32_t* len,
606         int nonblock)
607 {
608 	struct tube_res_list* item = NULL;
609 	verbose(VERB_ALGO, "tube read_msg %s", nonblock?"nonblock":"blocking");
610 	*buf = NULL;
611 	if(!tube_poll(tube)) {
612 		verbose(VERB_ALGO, "tube read_msg nodata");
613 		/* nothing ready right now, wait if we want to */
614 		if(nonblock)
615 			return -1; /* would block waiting for items */
616 		if(!tube_wait(tube))
617 			return 0;
618 	}
619 	lock_basic_lock(&tube->res_lock);
620 	if(tube->res_list) {
621 		item = tube->res_list;
622 		tube->res_list = item->next;
623 		if(tube->res_last == item) {
624 			/* the list is now empty */
625 			tube->res_last = NULL;
626 			verbose(VERB_ALGO, "tube read_msg lastdata");
627 			if(!WSAResetEvent(tube->event)) {
628 				log_err("WSAResetEvent: %s",
629 					wsa_strerror(WSAGetLastError()));
630 			}
631 		}
632 	}
633 	lock_basic_unlock(&tube->res_lock);
634 	if(!item)
635 		return 0; /* would block waiting for items */
636 	*buf = item->buf;
637 	*len = item->len;
638 	free(item);
639 	verbose(VERB_ALGO, "tube read_msg len %d", (int)*len);
640 	return 1;
641 }
642 
643 int tube_poll(struct tube* tube)
644 {
645 	struct tube_res_list* item = NULL;
646 	lock_basic_lock(&tube->res_lock);
647 	item = tube->res_list;
648 	lock_basic_unlock(&tube->res_lock);
649 	if(item)
650 		return 1;
651 	return 0;
652 }
653 
654 int tube_wait(struct tube* tube)
655 {
656 	/* block on eventhandle */
657 	DWORD res = WSAWaitForMultipleEvents(
658 		1 /* one event in array */,
659 		&tube->event /* the event to wait for, our pipe signal */,
660 		0 /* wait for all events is false */,
661 		WSA_INFINITE /* wait, no timeout */,
662 		0 /* we are not alertable for IO completion routines */
663 		);
664 	if(res == WSA_WAIT_TIMEOUT) {
665 		return 0;
666 	}
667 	if(res == WSA_WAIT_IO_COMPLETION) {
668 		/* a bit unexpected, since we were not alertable */
669 		return 0;
670 	}
671 	return 1;
672 }
673 
674 int tube_wait_timeout(struct tube* tube, int msec)
675 {
676 	/* block on eventhandle */
677 	DWORD res = WSAWaitForMultipleEvents(
678 		1 /* one event in array */,
679 		&tube->event /* the event to wait for, our pipe signal */,
680 		0 /* wait for all events is false */,
681 		msec /* wait for timeout */,
682 		0 /* we are not alertable for IO completion routines */
683 		);
684 	if(res == WSA_WAIT_TIMEOUT) {
685 		return 0;
686 	}
687 	if(res == WSA_WAIT_IO_COMPLETION) {
688 		/* a bit unexpected, since we were not alertable */
689 		return -1;
690 	}
691 	return 1;
692 }
693 
694 int tube_read_fd(struct tube* ATTR_UNUSED(tube))
695 {
696 	/* nothing sensible on Windows */
697 	return -1;
698 }
699 
700 int
701 tube_handle_listen(struct comm_point* ATTR_UNUSED(c), void* ATTR_UNUSED(arg),
702 	int ATTR_UNUSED(error), struct comm_reply* ATTR_UNUSED(reply_info))
703 {
704 	log_assert(0);
705 	return 0;
706 }
707 
708 int
709 tube_handle_write(struct comm_point* ATTR_UNUSED(c), void* ATTR_UNUSED(arg),
710 	int ATTR_UNUSED(error), struct comm_reply* ATTR_UNUSED(reply_info))
711 {
712 	log_assert(0);
713 	return 0;
714 }
715 
716 int tube_setup_bg_listen(struct tube* tube, struct comm_base* base,
717         tube_callback_type* cb, void* arg)
718 {
719 	tube->listen_cb = cb;
720 	tube->listen_arg = arg;
721 	if(!comm_base_internal(base))
722 		return 1; /* ignore when no comm base - testing */
723 	tube->ev_listen = ub_winsock_register_wsaevent(
724 	    comm_base_internal(base), tube->event, &tube_handle_signal, tube);
725 	return tube->ev_listen ? 1 : 0;
726 }
727 
728 int tube_setup_bg_write(struct tube* ATTR_UNUSED(tube),
729 	struct comm_base* ATTR_UNUSED(base))
730 {
731 	/* the queue item routine performs the signaling */
732 	return 1;
733 }
734 
735 int tube_queue_item(struct tube* tube, uint8_t* msg, size_t len)
736 {
737 	struct tube_res_list* item;
738 	if(!tube) return 0;
739 	item = (struct tube_res_list*)malloc(sizeof(*item));
740 	verbose(VERB_ALGO, "tube queue_item len %d", (int)len);
741 	if(!item) {
742 		free(msg);
743 		log_err("out of memory for async answer");
744 		return 0;
745 	}
746 	item->buf = msg;
747 	item->len = len;
748 	item->next = NULL;
749 	lock_basic_lock(&tube->res_lock);
750 	/* add at back of list, since the first one may be partially written */
751 	if(tube->res_last)
752 		tube->res_last->next = item;
753 	else    tube->res_list = item;
754 	tube->res_last = item;
755 	/* signal the eventhandle */
756 	if(!WSASetEvent(tube->event)) {
757 		log_err("WSASetEvent: %s", wsa_strerror(WSAGetLastError()));
758 	}
759 	lock_basic_unlock(&tube->res_lock);
760 	return 1;
761 }
762 
763 void tube_handle_signal(int ATTR_UNUSED(fd), short ATTR_UNUSED(events),
764 	void* arg)
765 {
766 	struct tube* tube = (struct tube*)arg;
767 	uint8_t* buf;
768 	uint32_t len = 0;
769 	verbose(VERB_ALGO, "tube handle_signal");
770 	while(tube_poll(tube)) {
771 		if(tube_read_msg(tube, &buf, &len, 1)) {
772 			fptr_ok(fptr_whitelist_tube_listen(tube->listen_cb));
773 			(*tube->listen_cb)(tube, buf, len, NETEVENT_NOERROR,
774 				tube->listen_arg);
775 		}
776 	}
777 }
778 
779 #endif /* USE_WINSOCK */
780