xref: /netbsd-src/lib/libpuffs/framebuf.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /*	$NetBSD: framebuf.c,v 1.35 2017/06/14 16:39:41 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 2007  Antti Kantee.  All Rights Reserved.
5  *
6  * Development of this software was supported by the
7  * Finnish Cultural Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
19  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 /*
32  * The event portion of this code is a twisty maze of pointers,
33  * flags, yields and continues.  Sincere aplogies.
34  */
35 
36 #include <sys/cdefs.h>
37 #if !defined(lint)
38 __RCSID("$NetBSD: framebuf.c,v 1.35 2017/06/14 16:39:41 christos Exp $");
39 #endif /* !lint */
40 
41 #include <sys/types.h>
42 #include <sys/queue.h>
43 
44 #include <assert.h>
45 #include <errno.h>
46 #include <poll.h>
47 #include <puffs.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <unistd.h>
51 
52 #include "puffs_priv.h"
53 
54 struct puffs_framebuf {
55 	struct puffs_cc *pcc;	/* pcc to continue with */
56 	/* OR */
57 	puffs_framev_cb fcb;	/* non-blocking callback */
58 	void *fcb_arg;		/* argument for previous */
59 
60 	uint8_t *buf;		/* buffer base */
61 	size_t len;		/* total length */
62 
63 	size_t offset;		/* cursor, telloff() */
64 	size_t maxoff;		/* maximum offset for data, tellsize() */
65 
66 	volatile int rv;	/* errno value */
67 
68 	int	istat;
69 
70 	TAILQ_ENTRY(puffs_framebuf) pfb_entries;
71 };
72 #define ISTAT_NODESTROY	0x01	/* indestructible by framebuf_destroy() */
73 #define ISTAT_INTERNAL	0x02	/* never leaves library			*/
74 #define ISTAT_NOREPLY	0x04	/* nuke after sending 			*/
75 #define ISTAT_DIRECT	0x08	/* receive directly, no moveinfo	*/
76 
77 #define ISTAT_ONQUEUE	ISTAT_NODESTROY	/* alias */
78 
79 #define PUFBUF_INCRALLOC 4096
80 #define PUFBUF_REMAIN(p) (p->len - p->offset)
81 
82 /* for poll/kqueue */
83 struct puffs_fbevent {
84 	struct puffs_cc	*pcc;
85 	int what;
86 	volatile int rv;
87 
88 	LIST_ENTRY(puffs_fbevent) pfe_entries;
89 };
90 
91 static struct puffs_fctrl_io *
92 getfiobyfd(struct puffs_usermount *pu, int fd)
93 {
94 	struct puffs_fctrl_io *fio;
95 
96 	LIST_FOREACH(fio, &pu->pu_ios, fio_entries)
97 		if (fio->io_fd == fd)
98 			return fio;
99 	return NULL;
100 }
101 
102 struct puffs_framebuf *
103 puffs_framebuf_make(void)
104 {
105 	struct puffs_framebuf *pufbuf;
106 
107 	pufbuf = malloc(sizeof(struct puffs_framebuf));
108 	if (pufbuf == NULL)
109 		return NULL;
110 	memset(pufbuf, 0, sizeof(struct puffs_framebuf));
111 
112 	pufbuf->buf = malloc(PUFBUF_INCRALLOC);
113 	if (pufbuf->buf == NULL) {
114 		free(pufbuf);
115 		return NULL;
116 	}
117 	pufbuf->len = PUFBUF_INCRALLOC;
118 
119 	puffs_framebuf_recycle(pufbuf);
120 	return pufbuf;
121 }
122 
123 void
124 puffs_framebuf_destroy(struct puffs_framebuf *pufbuf)
125 {
126 
127 	assert((pufbuf->istat & ISTAT_NODESTROY) == 0);
128 
129 	free(pufbuf->buf);
130 	free(pufbuf);
131 }
132 
133 void
134 puffs_framebuf_recycle(struct puffs_framebuf *pufbuf)
135 {
136 
137 	assert((pufbuf->istat & ISTAT_NODESTROY) == 0);
138 
139 	pufbuf->offset = 0;
140 	pufbuf->maxoff = 0;
141 	pufbuf->istat = 0;
142 }
143 
144 static int
145 reservespace(struct puffs_framebuf *pufbuf, size_t off, size_t wantsize)
146 {
147 	size_t incr;
148 	void *nd;
149 
150 	if (off <= pufbuf->len && pufbuf->len - off >= wantsize)
151 		return 0;
152 
153 	for (incr = PUFBUF_INCRALLOC;
154 	    pufbuf->len + incr < off + wantsize;
155 	    incr += PUFBUF_INCRALLOC)
156 		continue;
157 
158 	nd = realloc(pufbuf->buf, pufbuf->len + incr);
159 	if (nd == NULL)
160 		return -1;
161 
162 	pufbuf->buf = nd;
163 	pufbuf->len += incr;
164 
165 	return 0;
166 }
167 
168 int
169 puffs_framebuf_dup(struct puffs_framebuf *pb, struct puffs_framebuf **pbp)
170 {
171 	struct puffs_framebuf *newpb;
172 
173 	newpb = puffs_framebuf_make();
174 	if (newpb == NULL) {
175 		errno = ENOMEM;
176 		return -1;
177 	}
178 	memcpy(newpb, pb, sizeof(struct puffs_framebuf));
179 
180 	newpb->buf = NULL;
181 	newpb->len = 0;
182 	if (reservespace(newpb, 0, pb->maxoff) == -1) {
183 		puffs_framebuf_destroy(newpb);
184 		return -1;
185 	}
186 
187 	memcpy(newpb->buf, pb->buf, pb->maxoff);
188 	newpb->istat = 0;
189 	*pbp = newpb;
190 
191 	return 0;
192 }
193 
194 int
195 puffs_framebuf_reserve_space(struct puffs_framebuf *pufbuf, size_t wantsize)
196 {
197 
198 	return reservespace(pufbuf, pufbuf->offset, wantsize);
199 }
200 
201 int
202 puffs_framebuf_putdata(struct puffs_framebuf *pufbuf,
203 	const void *data, size_t dlen)
204 {
205 
206 	if (PUFBUF_REMAIN(pufbuf) < dlen)
207 		if (puffs_framebuf_reserve_space(pufbuf, dlen) == -1)
208 			return -1;
209 
210 	memcpy(pufbuf->buf + pufbuf->offset, data, dlen);
211 	pufbuf->offset += dlen;
212 
213 	if (pufbuf->offset > pufbuf->maxoff)
214 		pufbuf->maxoff = pufbuf->offset;
215 
216 	return 0;
217 }
218 
219 int
220 puffs_framebuf_putdata_atoff(struct puffs_framebuf *pufbuf, size_t offset,
221 	const void *data, size_t dlen)
222 {
223 
224 	if (reservespace(pufbuf, offset, dlen) == -1)
225 		return -1;
226 
227 	memcpy(pufbuf->buf + offset, data, dlen);
228 
229 	if (offset + dlen > pufbuf->maxoff)
230 		pufbuf->maxoff = offset + dlen;
231 
232 	return 0;
233 }
234 
235 int
236 puffs_framebuf_getdata(struct puffs_framebuf *pufbuf, void *data, size_t dlen)
237 {
238 
239 	if (pufbuf->maxoff < pufbuf->offset + dlen) {
240 		errno = ENOBUFS;
241 		return -1;
242 	}
243 
244 	memcpy(data, pufbuf->buf + pufbuf->offset, dlen);
245 	pufbuf->offset += dlen;
246 
247 	return 0;
248 }
249 
250 int
251 puffs_framebuf_getdata_atoff(struct puffs_framebuf *pufbuf, size_t offset,
252 	void *data, size_t dlen)
253 {
254 
255 	if (pufbuf->maxoff < offset + dlen) {
256 		errno = ENOBUFS;
257 		return -1;
258 	}
259 
260 	memcpy(data, pufbuf->buf + offset, dlen);
261 	return 0;
262 }
263 
264 size_t
265 puffs_framebuf_telloff(struct puffs_framebuf *pufbuf)
266 {
267 
268 	return pufbuf->offset;
269 }
270 
271 size_t
272 puffs_framebuf_tellsize(struct puffs_framebuf *pufbuf)
273 {
274 
275 	return pufbuf->maxoff;
276 }
277 
278 size_t
279 puffs_framebuf_remaining(struct puffs_framebuf *pufbuf)
280 {
281 
282 	return puffs_framebuf_tellsize(pufbuf) - puffs_framebuf_telloff(pufbuf);
283 }
284 
285 int
286 puffs_framebuf_seekset(struct puffs_framebuf *pufbuf, size_t newoff)
287 {
288 
289 	if (reservespace(pufbuf, newoff, 0) == -1)
290 		return -1;
291 
292 	pufbuf->offset = newoff;
293 	return 0;
294 }
295 
296 int
297 puffs_framebuf_getwindow(struct puffs_framebuf *pufbuf, size_t winoff,
298 	void **data, size_t *dlen)
299 {
300 	size_t winlen;
301 
302 #ifdef WINTESTING
303 	winlen = MIN(*dlen, 32);
304 #else
305 	winlen = *dlen;
306 #endif
307 
308 	if (reservespace(pufbuf, winoff, winlen) == -1)
309 		return -1;
310 
311 	*data = pufbuf->buf + winoff;
312 	if (pufbuf->maxoff < winoff + winlen)
313 		pufbuf->maxoff = winoff + winlen;
314 
315 	return 0;
316 }
317 
318 void *
319 puffs__framebuf_getdataptr(struct puffs_framebuf *pufbuf)
320 {
321 
322 	return pufbuf->buf;
323 }
324 
325 static void
326 errnotify(struct puffs_usermount *pu, struct puffs_framebuf *pufbuf, int error)
327 {
328 
329 	pufbuf->rv = error;
330 	if (pufbuf->pcc) {
331 		puffs__goto(pufbuf->pcc);
332 	} else if (pufbuf->fcb) {
333 		pufbuf->istat &= ~ISTAT_NODESTROY;
334 		pufbuf->fcb(pu, pufbuf, pufbuf->fcb_arg, error);
335 	} else {
336 		pufbuf->istat &= ~ISTAT_NODESTROY;
337 		puffs_framebuf_destroy(pufbuf);
338 	}
339 }
340 
341 #define GETFIO(fd)							\
342 do {									\
343 	fio = getfiobyfd(pu, fd);					\
344 	if (fio == NULL) {						\
345 		errno = EINVAL;						\
346 		return -1;						\
347 	}								\
348 	if (fio->stat & FIO_WRGONE) {					\
349 		errno = ESHUTDOWN;					\
350 		return -1;						\
351 	}								\
352 } while (/*CONSTCOND*/0)
353 
354 int
355 puffs_framev_enqueue_cc(struct puffs_cc *pcc, int fd,
356 	struct puffs_framebuf *pufbuf, int flags)
357 {
358 	struct puffs_usermount *pu = pcc->pcc_pu;
359 	struct puffs_fctrl_io *fio;
360 
361 	/*
362 	 * Technically we shouldn't allow this if RDGONE, but it's
363 	 * difficult to trap write close without allowing writes.
364 	 * And besides, there's probably a disconnect sequence in
365 	 * the protocol, so unexpectedly getting a closed fd is
366 	 * most likely an error condition.
367 	 */
368 	GETFIO(fd);
369 
370 	pufbuf->pcc = pcc;
371 	pufbuf->fcb = NULL;
372 	pufbuf->fcb_arg = NULL;
373 
374 	pufbuf->offset = 0;
375 	pufbuf->istat |= ISTAT_NODESTROY;
376 
377 	if (flags & PUFFS_FBQUEUE_URGENT)
378 		TAILQ_INSERT_HEAD(&fio->snd_qing, pufbuf, pfb_entries);
379 	else
380 		TAILQ_INSERT_TAIL(&fio->snd_qing, pufbuf, pfb_entries);
381 
382 	puffs_cc_yield(pcc);
383 	if (pufbuf->rv) {
384 		pufbuf->istat &= ~ISTAT_NODESTROY;
385 		errno = pufbuf->rv;
386 		return -1;
387 	}
388 
389 	return 0;
390 }
391 
392 int
393 puffs_framev_enqueue_cb(struct puffs_usermount *pu, int fd,
394 	struct puffs_framebuf *pufbuf, puffs_framev_cb fcb, void *arg,
395 	int flags)
396 {
397 	struct puffs_fctrl_io *fio;
398 
399 	/* see enqueue_cc */
400 	GETFIO(fd);
401 
402 	pufbuf->pcc = NULL;
403 	pufbuf->fcb = fcb;
404 	pufbuf->fcb_arg = arg;
405 
406 	pufbuf->offset = 0;
407 	pufbuf->istat |= ISTAT_NODESTROY;
408 
409 	if (flags & PUFFS_FBQUEUE_URGENT)
410 		TAILQ_INSERT_HEAD(&fio->snd_qing, pufbuf, pfb_entries);
411 	else
412 		TAILQ_INSERT_TAIL(&fio->snd_qing, pufbuf, pfb_entries);
413 
414 	return 0;
415 }
416 
417 int
418 puffs_framev_enqueue_justsend(struct puffs_usermount *pu, int fd,
419 	struct puffs_framebuf *pufbuf, int reply, int flags)
420 {
421 	struct puffs_fctrl_io *fio;
422 
423 	assert((pufbuf->istat & ISTAT_INTERNAL) == 0);
424 
425 	GETFIO(fd);
426 
427 	pufbuf->pcc = NULL;
428 	pufbuf->fcb = NULL;
429 	pufbuf->fcb_arg = NULL;
430 
431 	pufbuf->offset = 0;
432 	pufbuf->istat |= ISTAT_NODESTROY;
433 	if (!reply)
434 		pufbuf->istat |= ISTAT_NOREPLY;
435 
436 	if (flags & PUFFS_FBQUEUE_URGENT)
437 		TAILQ_INSERT_HEAD(&fio->snd_qing, pufbuf, pfb_entries);
438 	else
439 		TAILQ_INSERT_TAIL(&fio->snd_qing, pufbuf, pfb_entries);
440 
441 	return 0;
442 }
443 
444 /* ARGSUSED */
445 int
446 puffs_framev_enqueue_directreceive(struct puffs_cc *pcc, int fd,
447 	struct puffs_framebuf *pufbuf, int flags /* used in the future */)
448 {
449 	struct puffs_usermount *pu = pcc->pcc_pu;
450 	struct puffs_fctrl_io *fio;
451 
452 	assert((pufbuf->istat & ISTAT_INTERNAL) == 0);
453 
454 	fio = getfiobyfd(pu, fd);
455 	if (fio == NULL) {
456 		errno = EINVAL;
457 		return -1;
458 	}
459 
460 	/* XXX: should have cur_in queue */
461 	assert(fio->cur_in == NULL);
462 	fio->cur_in = pufbuf;
463 
464 	pufbuf->pcc = pcc;
465 	pufbuf->fcb = NULL;
466 	pufbuf->fcb_arg = NULL;
467 
468 	pufbuf->offset = 0;
469 	pufbuf->istat |= ISTAT_NODESTROY | ISTAT_DIRECT;
470 
471 	puffs_cc_yield(pcc);
472 	pufbuf->istat &= ~ISTAT_NODESTROY; /* XXX: not the right place */
473 	if (pufbuf->rv) {
474 		errno = pufbuf->rv;
475 		return -1;
476 	}
477 
478 	return 0;
479 }
480 
481 int
482 puffs_framev_enqueue_directsend(struct puffs_cc *pcc, int fd,
483 	struct puffs_framebuf *pufbuf, int flags)
484 {
485 	struct puffs_usermount *pu = pcc->pcc_pu;
486 	struct puffs_fctrl_io *fio;
487 
488 	assert((pufbuf->istat & ISTAT_INTERNAL) == 0);
489 
490 	if (flags & PUFFS_FBQUEUE_URGENT)
491 		abort(); /* EOPNOTSUPP for now */
492 
493 	GETFIO(fd);
494 
495 	pufbuf->pcc = pcc;
496 	pufbuf->fcb = NULL;
497 	pufbuf->fcb_arg = NULL;
498 
499 	pufbuf->offset = 0;
500 	pufbuf->istat |= ISTAT_NODESTROY | ISTAT_DIRECT;
501 
502 	TAILQ_INSERT_TAIL(&fio->snd_qing, pufbuf, pfb_entries);
503 
504 	puffs_cc_yield(pcc);
505 	if (pufbuf->rv) {
506 		pufbuf->istat &= ~ISTAT_NODESTROY;
507 		errno = pufbuf->rv;
508 		return -1;
509 	}
510 
511 	return 0;
512 }
513 
514 int
515 puffs_framev_framebuf_ccpromote(struct puffs_framebuf *pufbuf,
516 	struct puffs_cc *pcc)
517 {
518 
519 	if ((pufbuf->istat & ISTAT_ONQUEUE) == 0) {
520 		errno = EBUSY;
521 		return -1;
522 	}
523 
524 	pufbuf->pcc = pcc;
525 	pufbuf->fcb = NULL;
526 	pufbuf->fcb_arg = NULL;
527 	pufbuf->istat &= ~ISTAT_NOREPLY;
528 
529 	puffs_cc_yield(pcc);
530 
531 	return 0;
532 }
533 
534 int
535 puffs_framev_enqueue_waitevent(struct puffs_cc *pcc, int fd, int *what)
536 {
537 	struct puffs_usermount *pu = pcc->pcc_pu;
538 	struct puffs_fctrl_io *fio;
539 	struct puffs_fbevent feb;
540 	struct kevent kev;
541 	int rv, svwhat;
542 
543 	svwhat = *what;
544 
545 	if (*what == 0) {
546 		errno = EINVAL;
547 		return -1;
548 	}
549 
550 	fio = getfiobyfd(pu, fd);
551 	if (fio == NULL) {
552 		errno = EINVAL;
553 		return -1;
554 	}
555 
556 	feb.pcc = pcc;
557 	feb.what = *what & (PUFFS_FBIO_READ|PUFFS_FBIO_WRITE|PUFFS_FBIO_ERROR);
558 
559 	if (*what & PUFFS_FBIO_READ)
560 		if ((fio->stat & FIO_ENABLE_R) == 0)
561 			EV_SET(&kev, fd, EVFILT_READ, EV_ENABLE, 0, 0, fio);
562 
563 	if (kevent(pu->pu_kq, &kev, 1, NULL, 0, NULL) == -1)
564 		return -1;
565 
566 	if (*what & PUFFS_FBIO_READ)
567 		fio->rwait++;
568 	if (*what & PUFFS_FBIO_WRITE)
569 		fio->wwait++;
570 
571 	LIST_INSERT_HEAD(&fio->ev_qing, &feb, pfe_entries);
572 	puffs_cc_yield(pcc);
573 
574 	assert(svwhat == *what);
575 
576 	if (*what & PUFFS_FBIO_READ) {
577 		fio->rwait--;
578 		if (fio->rwait == 0 && (fio->stat & FIO_ENABLE_R) == 0) {
579 			EV_SET(&kev, fd, EVFILT_READ, EV_DISABLE, 0, 0, fio);
580 			rv = kevent(pu->pu_kq, &kev, 1, NULL, 0, NULL);
581 #if 0
582 			if (rv != 0)
583 				/* XXXXX oh dear */;
584 #endif
585 		}
586 	}
587 	if (*what & PUFFS_FBIO_WRITE)
588 		fio->wwait--;
589 
590 	if (feb.rv == 0) {
591 		*what = feb.what;
592 		rv = 0;
593 	} else {
594 		*what = PUFFS_FBIO_ERROR;
595 		errno = feb.rv;
596 		rv = -1;
597 	}
598 
599 	return rv;
600 }
601 
602 void
603 puffs__framev_notify(struct puffs_fctrl_io *fio, int what)
604 {
605 	struct puffs_fbevent *fbevp;
606 
607  restart:
608 	LIST_FOREACH(fbevp, &fio->ev_qing, pfe_entries) {
609 		if (fbevp->what & what) {
610 			fbevp->what = what;
611 			fbevp->rv = 0;
612 			LIST_REMOVE(fbevp, pfe_entries);
613 			puffs_cc_continue(fbevp->pcc);
614 			goto restart;
615 		}
616 	}
617 }
618 
619 static struct puffs_framebuf *
620 findbuf(struct puffs_usermount *pu, struct puffs_framectrl *fctrl,
621 	struct puffs_fctrl_io *fio, struct puffs_framebuf *findme)
622 {
623 	struct puffs_framebuf *cand;
624 	int notresp = 0;
625 
626 	TAILQ_FOREACH(cand, &fio->res_qing, pfb_entries)
627 		if (fctrl->cmpfb(pu, findme, cand, &notresp) == 0 || notresp)
628 			break;
629 
630 	assert(!(notresp && cand == NULL));
631 	if (notresp || cand == NULL)
632 		return NULL;
633 
634 	TAILQ_REMOVE(&fio->res_qing, cand, pfb_entries);
635 	return cand;
636 }
637 
638 void
639 puffs__framebuf_moveinfo(struct puffs_framebuf *from, struct puffs_framebuf *to)
640 {
641 
642 	assert(from->istat & ISTAT_INTERNAL);
643 
644 	/* migrate buffer */
645 	free(to->buf);
646 	to->buf = from->buf;
647 
648 	/* migrate buffer info */
649 	to->len = from->len;
650 	to->offset = from->offset;
651 	to->maxoff = from->maxoff;
652 
653 	from->buf = NULL;
654 	from->len = 0;
655 }
656 
657 void
658 puffs__framev_input(struct puffs_usermount *pu, struct puffs_framectrl *fctrl,
659 	struct puffs_fctrl_io *fio)
660 {
661 	struct puffs_framebuf *pufbuf, *appbuf;
662 	int rv, complete;
663 
664 	while ((fio->stat & FIO_DEAD) == 0 && (fio->stat & FIO_ENABLE_R)) {
665 		if ((pufbuf = fio->cur_in) == NULL) {
666 			pufbuf = puffs_framebuf_make();
667 			if (pufbuf == NULL)
668 				return;
669 			pufbuf->istat |= ISTAT_INTERNAL;
670 			fio->cur_in = pufbuf;
671 		}
672 
673 		complete = 0;
674 		rv = fctrl->rfb(pu, pufbuf, fio->io_fd, &complete);
675 
676 		/* error */
677 		if (rv) {
678 			puffs__framev_readclose(pu, fio, rv);
679 			fio->cur_in = NULL;
680 			return;
681 		}
682 
683 		/* partial read, come back to fight another day */
684 		if (complete == 0)
685 			break;
686 
687 		/* else: full read, process */
688 		fio->cur_in = NULL;
689 		if ((pufbuf->istat & ISTAT_DIRECT) == 0) {
690 			appbuf = findbuf(pu, fctrl, fio, pufbuf);
691 
692 			/*
693 			 * No request for this frame?  If fs implements
694 			 * gotfb, give frame to that.  Otherwise drop it.
695 			 */
696 			if (appbuf == NULL) {
697 				if (fctrl->gotfb) {
698 					pufbuf->istat &= ~ISTAT_INTERNAL;
699 					fctrl->gotfb(pu, pufbuf);
700 				} else {
701 					puffs_framebuf_destroy(pufbuf);
702 				}
703 				continue;
704 			}
705 
706 			puffs__framebuf_moveinfo(pufbuf, appbuf);
707 			puffs_framebuf_destroy(pufbuf);
708 		} else {
709 			appbuf = pufbuf;
710 		}
711 		appbuf->istat &= ~ISTAT_NODESTROY;
712 
713 		if (appbuf->pcc) {
714 			puffs__cc_cont(appbuf->pcc);
715 		} else if (appbuf->fcb) {
716 			appbuf->fcb(pu, appbuf, appbuf->fcb_arg, 0);
717 		} else {
718 			puffs_framebuf_destroy(appbuf);
719 		}
720 
721 		/* hopeless romantics, here we go again */
722 	}
723 }
724 
725 int
726 puffs__framev_output(struct puffs_usermount *pu, struct puffs_framectrl *fctrl,
727 	struct puffs_fctrl_io *fio)
728 {
729 	struct puffs_framebuf *pufbuf;
730 	int rv, complete, done;
731 
732 	if (fio->stat & FIO_DEAD)
733 		return 0;
734 
735 	for (pufbuf = TAILQ_FIRST(&fio->snd_qing), done = 0;
736 	    pufbuf && (fio->stat & FIO_DEAD) == 0 && fio->stat & FIO_ENABLE_W;
737 	    pufbuf = TAILQ_FIRST(&fio->snd_qing)) {
738 		complete = 0;
739 		rv = fctrl->wfb(pu, pufbuf, fio->io_fd, &complete);
740 
741 		if (rv) {
742 			puffs__framev_writeclose(pu, fio, rv);
743 			done = 1;
744 			break;
745 		}
746 
747 		/* partial write */
748 		if (complete == 0)
749 			return done;
750 
751 		/* else, complete write */
752 		TAILQ_REMOVE(&fio->snd_qing, pufbuf, pfb_entries);
753 
754 		/* can't wait for result if we can't read */
755 		if (fio->stat & FIO_RDGONE) {
756 			errnotify(pu, pufbuf, ENXIO);
757 			done = 1;
758 		} else if ((pufbuf->istat & ISTAT_DIRECT)) {
759 			pufbuf->istat &= ~ISTAT_NODESTROY;
760 			done = 1;
761 			puffs__cc_cont(pufbuf->pcc);
762 		} else if ((pufbuf->istat & ISTAT_NOREPLY) == 0) {
763 			TAILQ_INSERT_TAIL(&fio->res_qing, pufbuf,
764 			    pfb_entries);
765 		} else {
766 			pufbuf->istat &= ~ISTAT_NODESTROY;
767 			puffs_framebuf_destroy(pufbuf);
768 		}
769 
770 		/* omstart! */
771 	}
772 
773 	return done;
774 }
775 
776 int
777 puffs__framev_addfd_ctrl(struct puffs_usermount *pu, int fd, int what,
778 	struct puffs_framectrl *pfctrl)
779 {
780 	struct puffs_fctrl_io *fio;
781 	struct kevent *newevs;
782 	struct kevent kev[2];
783 	size_t nevs;
784 	int rv, readenable;
785 
786 	nevs = pu->pu_nevs+2;
787 	newevs = realloc(pu->pu_evs, nevs*sizeof(struct kevent));
788 	if (newevs == NULL)
789 		return -1;
790 	pu->pu_evs = newevs;
791 
792 	fio = malloc(sizeof(struct puffs_fctrl_io));
793 	if (fio == NULL)
794 		return -1;
795 	memset(fio, 0, sizeof(struct puffs_fctrl_io));
796 	fio->io_fd = fd;
797 	fio->cur_in = NULL;
798 	fio->fctrl = pfctrl;
799 	TAILQ_INIT(&fio->snd_qing);
800 	TAILQ_INIT(&fio->res_qing);
801 	LIST_INIT(&fio->ev_qing);
802 
803 	readenable = 0;
804 	if ((what & PUFFS_FBIO_READ) == 0)
805 		readenable = EV_DISABLE;
806 
807 	if (pu->pu_state & PU_INLOOP) {
808 		struct stat st;
809 		size_t nf = 0;
810 
811 		if (fstat(fd, &st) == -1)
812 			goto out;
813 		EV_SET(&kev[nf], fd, EVFILT_READ, EV_ADD|readenable, 0, 0, fio);
814 		nf++;
815 		if (S_ISSOCK(st.st_mode)) {
816 			EV_SET(&kev[nf], fd, EVFILT_WRITE,
817 			    EV_ADD|EV_DISABLE, 0, 0, fio);
818 			nf++;
819 		}
820 		rv = kevent(pu->pu_kq, kev, nf, NULL, 0, NULL);
821 		if (rv == -1)
822 			goto out;
823 	}
824 	if (what & PUFFS_FBIO_READ)
825 		fio->stat |= FIO_ENABLE_R;
826 	if (what & PUFFS_FBIO_WRITE)
827 		fio->stat |= FIO_ENABLE_W;
828 
829 	LIST_INSERT_HEAD(&pu->pu_ios, fio, fio_entries);
830 	pu->pu_nevs = nevs;
831 
832 	return 0;
833 out:
834 	free(fio);
835 	return -1;
836 }
837 
838 int
839 puffs_framev_addfd(struct puffs_usermount *pu, int fd, int what)
840 {
841 
842 	return puffs__framev_addfd_ctrl(pu, fd, what,
843 	    &pu->pu_framectrl[PU_FRAMECTRL_USER]);
844 }
845 
846 /*
847  * XXX: the following en/disable should be coalesced and executed
848  * only during the actual kevent call.  So feel free to fix if
849  * threatened by mindblowing boredom.
850  */
851 
852 int
853 puffs_framev_enablefd(struct puffs_usermount *pu, int fd, int what)
854 {
855 	struct kevent kev;
856 	struct puffs_fctrl_io *fio;
857 	int rv = 0;
858 
859 	assert((what & (PUFFS_FBIO_READ | PUFFS_FBIO_WRITE)) != 0);
860 
861 	fio = getfiobyfd(pu, fd);
862 	if (fio == NULL) {
863 		errno = ENXIO;
864 		return -1;
865 	}
866 
867 	/* write is enabled in the event loop if there is output */
868 	if (what & PUFFS_FBIO_READ && fio->rwait == 0) {
869 		EV_SET(&kev, fd, EVFILT_READ, EV_ENABLE, 0, 0, fio);
870 		rv = kevent(pu->pu_kq, &kev, 1, NULL, 0, NULL);
871 	}
872 
873 	if (rv == 0) {
874 		if (what & PUFFS_FBIO_READ)
875 			fio->stat |= FIO_ENABLE_R;
876 		if (what & PUFFS_FBIO_WRITE)
877 			fio->stat |= FIO_ENABLE_W;
878 	}
879 
880 	return rv;
881 }
882 
883 int
884 puffs_framev_disablefd(struct puffs_usermount *pu, int fd, int what)
885 {
886 	struct kevent kev[2];
887 	struct puffs_fctrl_io *fio;
888 	size_t i;
889 	int rv;
890 
891 	assert((what & (PUFFS_FBIO_READ | PUFFS_FBIO_WRITE)) != 0);
892 
893 	fio = getfiobyfd(pu, fd);
894 	if (fio == NULL) {
895 		errno = ENXIO;
896 		return -1;
897 	}
898 
899 	i = 0;
900 	if (what & PUFFS_FBIO_READ && fio->rwait == 0) {
901 		EV_SET(&kev[0], fd, EVFILT_READ, EV_DISABLE, 0, 0, fio);
902 		i++;
903 	}
904 	if (what & PUFFS_FBIO_WRITE && fio->stat & FIO_WR && fio->wwait == 0) {
905 		EV_SET(&kev[1], fd, EVFILT_WRITE, EV_DISABLE, 0, 0, fio);
906 		i++;
907 	}
908 	if (i)
909 		rv = kevent(pu->pu_kq, kev, i, NULL, 0, NULL);
910 	else
911 		rv = 0;
912 
913 	if (rv == 0) {
914 		if (what & PUFFS_FBIO_READ)
915 			fio->stat &= ~FIO_ENABLE_R;
916 		if (what & PUFFS_FBIO_WRITE)
917 			fio->stat &= ~FIO_ENABLE_W;
918 	}
919 
920 	return rv;
921 }
922 
923 void
924 puffs__framev_readclose(struct puffs_usermount *pu,
925 	struct puffs_fctrl_io *fio, int error)
926 {
927 	struct puffs_framebuf *pufbuf;
928 	struct kevent kev;
929 	int notflag;
930 
931 	if (fio->stat & FIO_RDGONE || fio->stat & FIO_DEAD)
932 		return;
933 	fio->stat |= FIO_RDGONE;
934 
935 	if (fio->cur_in) {
936 		if ((fio->cur_in->istat & ISTAT_DIRECT) == 0) {
937 			puffs_framebuf_destroy(fio->cur_in);
938 			fio->cur_in = NULL;
939 		} else {
940 			errnotify(pu, fio->cur_in, error);
941 		}
942 	}
943 
944 	while ((pufbuf = TAILQ_FIRST(&fio->res_qing)) != NULL) {
945 		TAILQ_REMOVE(&fio->res_qing, pufbuf, pfb_entries);
946 		errnotify(pu, pufbuf, error);
947 	}
948 
949 	EV_SET(&kev, fio->io_fd, EVFILT_READ, EV_DELETE, 0, 0, 0);
950 	(void) kevent(pu->pu_kq, &kev, 1, NULL, 0, NULL);
951 
952 	notflag = PUFFS_FBIO_READ;
953 	if (fio->stat & FIO_WRGONE)
954 		notflag |= PUFFS_FBIO_WRITE;
955 
956 	if (fio->fctrl->fdnotfn)
957 		fio->fctrl->fdnotfn(pu, fio->io_fd, notflag);
958 }
959 
960 void
961 puffs__framev_writeclose(struct puffs_usermount *pu,
962 	struct puffs_fctrl_io *fio, int error)
963 {
964 	struct puffs_framebuf *pufbuf;
965 	struct kevent kev;
966 	int notflag;
967 
968 	if (fio->stat & FIO_WRGONE || fio->stat & FIO_DEAD)
969 		return;
970 	fio->stat |= FIO_WRGONE;
971 
972 	while ((pufbuf = TAILQ_FIRST(&fio->snd_qing)) != NULL) {
973 		TAILQ_REMOVE(&fio->snd_qing, pufbuf, pfb_entries);
974 		errnotify(pu, pufbuf, error);
975 	}
976 
977 	EV_SET(&kev, fio->io_fd, EVFILT_WRITE, EV_DELETE, 0, 0, 0);
978 	(void) kevent(pu->pu_kq, &kev, 1, NULL, 0, NULL);
979 
980 	notflag = PUFFS_FBIO_WRITE;
981 	if (fio->stat & FIO_RDGONE)
982 		notflag |= PUFFS_FBIO_READ;
983 
984 	if (fio->fctrl->fdnotfn)
985 		fio->fctrl->fdnotfn(pu, fio->io_fd, notflag);
986 }
987 
988 static int
989 removefio(struct puffs_usermount *pu, struct puffs_fctrl_io *fio, int error)
990 {
991 	struct puffs_fbevent *fbevp;
992 
993 	LIST_REMOVE(fio, fio_entries);
994 	if (pu->pu_state & PU_INLOOP) {
995 		puffs__framev_readclose(pu, fio, error);
996 		puffs__framev_writeclose(pu, fio, error);
997 	}
998 
999 	while ((fbevp = LIST_FIRST(&fio->ev_qing)) != NULL) {
1000 		fbevp->rv = error;
1001 		LIST_REMOVE(fbevp, pfe_entries);
1002 		puffs__goto(fbevp->pcc);
1003 	}
1004 
1005 	/* don't bother with realloc */
1006 	pu->pu_nevs -= 2;
1007 
1008 	/* don't free us yet, might have some references in event arrays */
1009 	fio->stat |= FIO_DEAD;
1010 	LIST_INSERT_HEAD(&pu->pu_ios_rmlist, fio, fio_entries);
1011 
1012 	return 0;
1013 
1014 }
1015 
1016 int
1017 puffs_framev_removefd(struct puffs_usermount *pu, int fd, int error)
1018 {
1019 	struct puffs_fctrl_io *fio;
1020 
1021 	fio = getfiobyfd(pu, fd);
1022 	if (fio == NULL) {
1023 		errno = ENXIO;
1024 		return -1;
1025 	}
1026 
1027 	return removefio(pu, fio, error ? error : ECONNRESET);
1028 }
1029 
1030 void
1031 puffs_framev_removeonclose(struct puffs_usermount *pu, int fd, int what)
1032 {
1033 
1034 	if (what == (PUFFS_FBIO_READ | PUFFS_FBIO_WRITE))
1035 		(void) puffs_framev_removefd(pu, fd, ECONNRESET);
1036 }
1037 
1038 void
1039 puffs_framev_unmountonclose(struct puffs_usermount *pu, int fd, int what)
1040 {
1041 
1042 	/* XXX & X: unmount is non-sensible */
1043 	puffs_framev_removeonclose(pu, fd, what);
1044 	if (what == (PUFFS_FBIO_READ | PUFFS_FBIO_WRITE))
1045 		PU_SETSTATE(pu, PUFFS_STATE_UNMOUNTED);
1046 }
1047 
1048 void
1049 puffs_framev_init(struct puffs_usermount *pu,
1050 	puffs_framev_readframe_fn rfb, puffs_framev_writeframe_fn wfb,
1051 	puffs_framev_cmpframe_fn cmpfb, puffs_framev_gotframe_fn gotfb,
1052 	puffs_framev_fdnotify_fn fdnotfn)
1053 {
1054 	struct puffs_framectrl *pfctrl;
1055 
1056 	pfctrl = &pu->pu_framectrl[PU_FRAMECTRL_USER];
1057 	pfctrl->rfb = rfb;
1058 	pfctrl->wfb = wfb;
1059 	pfctrl->cmpfb = cmpfb;
1060 	pfctrl->gotfb = gotfb;
1061 	pfctrl->fdnotfn = fdnotfn;
1062 }
1063 
1064 void
1065 puffs__framev_exit(struct puffs_usermount *pu)
1066 {
1067 	struct puffs_fctrl_io *fio;
1068 
1069 	while ((fio = LIST_FIRST(&pu->pu_ios)) != NULL)
1070 		removefio(pu, fio, ENXIO);
1071 	free(pu->pu_evs);
1072 
1073 	/* closing pu->pu_kq takes care of puffsfd */
1074 }
1075