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framebuf.c revision 1.28
      1 /*	$NetBSD: framebuf.c,v 1.28 2008/01/29 10:07:29 pooka 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 1.28 2008/01/29 10:07:29 pooka 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()
    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,
    562 			    0, 0, (uintptr_t)fio);
    563 
    564 	rv = kevent(pu->pu_kq, &kev, 1, NULL, 0, NULL);
    565 	if (rv != 0)
    566 		return errno;
    567 
    568 	if (*what & PUFFS_FBIO_READ)
    569 		fio->rwait++;
    570 	if (*what & PUFFS_FBIO_WRITE)
    571 		fio->wwait++;
    572 
    573 	LIST_INSERT_HEAD(&fio->ev_qing, &feb, pfe_entries);
    574 	puffs_cc_yield(pcc);
    575 
    576 	assert(svwhat == *what);
    577 
    578 	if (*what & PUFFS_FBIO_READ) {
    579 		fio->rwait--;
    580 		if (fio->rwait == 0 && (fio->stat & FIO_ENABLE_R) == 0) {
    581 			EV_SET(&kev, fd, EVFILT_READ, EV_DISABLE,
    582 			    0, 0, (uintptr_t)fio);
    583 			rv = kevent(pu->pu_kq, &kev, 1, NULL, 0, NULL);
    584 #if 0
    585 			if (rv != 0)
    586 				/* XXXXX oh dear */;
    587 #endif
    588 		}
    589 	}
    590 	if (*what & PUFFS_FBIO_WRITE)
    591 		fio->wwait--;
    592 
    593 	if (feb.rv == 0) {
    594 		*what = feb.what;
    595 		rv = 0;
    596 	} else {
    597 		*what = PUFFS_FBIO_ERROR;
    598 		errno = feb.rv;
    599 		rv = -1;
    600 	}
    601 
    602 	return rv;
    603 }
    604 
    605 void
    606 puffs__framev_notify(struct puffs_fctrl_io *fio, int what)
    607 {
    608 	struct puffs_fbevent *fbevp;
    609 
    610  restart:
    611 	LIST_FOREACH(fbevp, &fio->ev_qing, pfe_entries) {
    612 		if (fbevp->what & what) {
    613 			fbevp->what = what;
    614 			fbevp->rv = 0;
    615 			LIST_REMOVE(fbevp, pfe_entries);
    616 			puffs_cc_continue(fbevp->pcc);
    617 			goto restart;
    618 		}
    619 	}
    620 }
    621 
    622 static struct puffs_framebuf *
    623 findbuf(struct puffs_usermount *pu, struct puffs_framectrl *fctrl,
    624 	struct puffs_fctrl_io *fio, struct puffs_framebuf *findme)
    625 {
    626 	struct puffs_framebuf *cand;
    627 	int notresp = 0;
    628 
    629 	TAILQ_FOREACH(cand, &fio->res_qing, pfb_entries)
    630 		if (fctrl->cmpfb(pu, findme, cand, &notresp) == 0 || notresp)
    631 			break;
    632 
    633 	assert(!(notresp && cand == NULL));
    634 	if (notresp || cand == NULL)
    635 		return NULL;
    636 
    637 	TAILQ_REMOVE(&fio->res_qing, cand, pfb_entries);
    638 	return cand;
    639 }
    640 
    641 void
    642 puffs__framebuf_moveinfo(struct puffs_framebuf *from, struct puffs_framebuf *to)
    643 {
    644 
    645 	assert(from->istat & ISTAT_INTERNAL);
    646 
    647 	/* migrate buffer */
    648 	free(to->buf);
    649 	to->buf = from->buf;
    650 
    651 	/* migrate buffer info */
    652 	to->len = from->len;
    653 	to->offset = from->offset;
    654 	to->maxoff = from->maxoff;
    655 
    656 	from->buf = NULL;
    657 	from->len = 0;
    658 }
    659 
    660 void
    661 puffs__framev_input(struct puffs_usermount *pu, struct puffs_framectrl *fctrl,
    662 	struct puffs_fctrl_io *fio)
    663 {
    664 	struct puffs_framebuf *pufbuf, *appbuf;
    665 	int rv, complete;
    666 
    667 	while ((fio->stat & FIO_DEAD) == 0 && (fio->stat & FIO_ENABLE_R)) {
    668 		if ((pufbuf = fio->cur_in) == NULL) {
    669 			pufbuf = puffs_framebuf_make();
    670 			if (pufbuf == NULL)
    671 				return;
    672 			pufbuf->istat |= ISTAT_INTERNAL;
    673 			fio->cur_in = pufbuf;
    674 		}
    675 
    676 		complete = 0;
    677 		rv = fctrl->rfb(pu, pufbuf, fio->io_fd, &complete);
    678 
    679 		/* error */
    680 		if (rv) {
    681 			puffs__framev_readclose(pu, fio, rv);
    682 			fio->cur_in = NULL;
    683 			if ((pufbuf->istat & ISTAT_DIRECT) == 0) {
    684 				assert((pufbuf->istat & ISTAT_NODESTROY) == 0);
    685 				puffs_framebuf_destroy(pufbuf);
    686 			}
    687 			return;
    688 		}
    689 
    690 		/* partial read, come back to fight another day */
    691 		if (complete == 0)
    692 			break;
    693 
    694 		/* else: full read, process */
    695 		fio->cur_in = NULL;
    696 		if ((pufbuf->istat & ISTAT_DIRECT) == 0) {
    697 			appbuf = findbuf(pu, fctrl, fio, pufbuf);
    698 
    699 			/*
    700 			 * No request for this frame?  If fs implements
    701 			 * gotfb, give frame to that.  Otherwise drop it.
    702 			 */
    703 			if (appbuf == NULL) {
    704 				if (fctrl->gotfb) {
    705 					pufbuf->istat &= ~ISTAT_INTERNAL;
    706 					fctrl->gotfb(pu, pufbuf);
    707 				} else {
    708 					puffs_framebuf_destroy(pufbuf);
    709 				}
    710 				continue;
    711 			}
    712 
    713 			puffs__framebuf_moveinfo(pufbuf, appbuf);
    714 			puffs_framebuf_destroy(pufbuf);
    715 		} else {
    716 			appbuf = pufbuf;
    717 		}
    718 		appbuf->istat &= ~ISTAT_NODESTROY;
    719 
    720 		if (appbuf->pcc) {
    721 			puffs__cc_cont(appbuf->pcc);
    722 		} else if (appbuf->fcb) {
    723 			appbuf->fcb(pu, appbuf, appbuf->fcb_arg, 0);
    724 		} else {
    725 			puffs_framebuf_destroy(appbuf);
    726 		}
    727 
    728 		/* hopeless romantics, here we go again */
    729 	}
    730 }
    731 
    732 int
    733 puffs__framev_output(struct puffs_usermount *pu, struct puffs_framectrl *fctrl,
    734 	struct puffs_fctrl_io *fio)
    735 {
    736 	struct puffs_framebuf *pufbuf;
    737 	int rv, complete, done;
    738 
    739 	if (fio->stat & FIO_DEAD)
    740 		return 0;
    741 
    742 	for (pufbuf = TAILQ_FIRST(&fio->snd_qing), done = 0;
    743 	    pufbuf && (fio->stat & FIO_DEAD) == 0 && fio->stat & FIO_ENABLE_W;
    744 	    pufbuf = TAILQ_FIRST(&fio->snd_qing)) {
    745 		complete = 0;
    746 		rv = fctrl->wfb(pu, pufbuf, fio->io_fd, &complete);
    747 
    748 		if (rv) {
    749 			puffs__framev_writeclose(pu, fio, rv);
    750 			done = 1;
    751 			break;
    752 		}
    753 
    754 		/* partial write */
    755 		if (complete == 0)
    756 			return done;
    757 
    758 		/* else, complete write */
    759 		TAILQ_REMOVE(&fio->snd_qing, pufbuf, pfb_entries);
    760 
    761 		/* can't wait for result if we can't read */
    762 		if (fio->stat & FIO_RDGONE) {
    763 			errnotify(pu, pufbuf, ENXIO);
    764 			done = 1;
    765 		} else if ((pufbuf->istat & ISTAT_DIRECT)) {
    766 			pufbuf->istat &= ~ISTAT_NODESTROY;
    767 			done = 1;
    768 			puffs__cc_cont(pufbuf->pcc);
    769 		} else if ((pufbuf->istat & ISTAT_NOREPLY) == 0) {
    770 			TAILQ_INSERT_TAIL(&fio->res_qing, pufbuf,
    771 			    pfb_entries);
    772 		} else {
    773 			pufbuf->istat &= ~ISTAT_NODESTROY;
    774 			puffs_framebuf_destroy(pufbuf);
    775 		}
    776 
    777 		/* omstart! */
    778 	}
    779 
    780 	return done;
    781 }
    782 
    783 int
    784 puffs__framev_addfd_ctrl(struct puffs_usermount *pu, int fd, int what,
    785 	struct puffs_framectrl *pfctrl)
    786 {
    787 	struct puffs_fctrl_io *fio;
    788 	struct kevent *newevs;
    789 	struct kevent kev[2];
    790 	size_t nfds;
    791 	int rv, readenable;
    792 
    793 	nfds = pu->pu_nfds+1;
    794 	newevs = realloc(pu->pu_evs, (2*nfds) * sizeof(struct kevent));
    795 	if (newevs == NULL)
    796 		return -1;
    797 	pu->pu_evs = newevs;
    798 
    799 	fio = malloc(sizeof(struct puffs_fctrl_io));
    800 	if (fio == NULL)
    801 		return -1;
    802 	memset(fio, 0, sizeof(struct puffs_fctrl_io));
    803 	fio->io_fd = fd;
    804 	fio->cur_in = NULL;
    805 	fio->fctrl = pfctrl;
    806 	TAILQ_INIT(&fio->snd_qing);
    807 	TAILQ_INIT(&fio->res_qing);
    808 	LIST_INIT(&fio->ev_qing);
    809 
    810 	readenable = 0;
    811 	if ((what & PUFFS_FBIO_READ) == 0)
    812 		readenable = EV_DISABLE;
    813 
    814 	if (pu->pu_state & PU_INLOOP) {
    815 		EV_SET(&kev[0], fd, EVFILT_READ,
    816 		    EV_ADD|readenable, 0, 0, (intptr_t)fio);
    817 		EV_SET(&kev[1], fd, EVFILT_WRITE,
    818 		    EV_ADD|EV_DISABLE, 0, 0, (intptr_t)fio);
    819 		rv = kevent(pu->pu_kq, kev, 2, NULL, 0, NULL);
    820 		if (rv == -1) {
    821 			free(fio);
    822 			return -1;
    823 		}
    824 	}
    825 	if (what & PUFFS_FBIO_READ)
    826 		fio->stat |= FIO_ENABLE_R;
    827 	if (what & PUFFS_FBIO_WRITE)
    828 		fio->stat |= FIO_ENABLE_W;
    829 
    830 	LIST_INSERT_HEAD(&pu->pu_ios, fio, fio_entries);
    831 	pu->pu_nfds = nfds;
    832 
    833 	return 0;
    834 }
    835 
    836 int
    837 puffs_framev_addfd(struct puffs_usermount *pu, int fd, int what)
    838 {
    839 
    840 	return puffs__framev_addfd_ctrl(pu, fd, what,
    841 	    &pu->pu_framectrl[PU_FRAMECTRL_USER]);
    842 }
    843 
    844 /*
    845  * XXX: the following en/disable should be coalesced and executed
    846  * only during the actual kevent call.  So feel free to fix if
    847  * threatened by mindblowing boredom.
    848  */
    849 
    850 int
    851 puffs_framev_enablefd(struct puffs_usermount *pu, int fd, int what)
    852 {
    853 	struct kevent kev;
    854 	struct puffs_fctrl_io *fio;
    855 	int rv = 0;
    856 
    857 	assert((what & (PUFFS_FBIO_READ | PUFFS_FBIO_WRITE)) != 0);
    858 
    859 	fio = getfiobyfd(pu, fd);
    860 	if (fio == NULL) {
    861 		errno = ENXIO;
    862 		return -1;
    863 	}
    864 
    865 	/* write is enabled in the event loop if there is output */
    866 	if (what & PUFFS_FBIO_READ && fio->rwait == 0) {
    867 		EV_SET(&kev, fd, EVFILT_READ, EV_ENABLE, 0, 0, (uintptr_t)fio);
    868 		rv = kevent(pu->pu_kq, &kev, 1, NULL, 0, NULL);
    869 	}
    870 
    871 	if (rv == 0) {
    872 		if (what & PUFFS_FBIO_READ)
    873 			fio->stat |= FIO_ENABLE_R;
    874 		if (what & PUFFS_FBIO_WRITE)
    875 			fio->stat |= FIO_ENABLE_W;
    876 	}
    877 
    878 	return rv;
    879 }
    880 
    881 int
    882 puffs_framev_disablefd(struct puffs_usermount *pu, int fd, int what)
    883 {
    884 	struct kevent kev[2];
    885 	struct puffs_fctrl_io *fio;
    886 	size_t i;
    887 	int rv;
    888 
    889 	assert((what & (PUFFS_FBIO_READ | PUFFS_FBIO_WRITE)) != 0);
    890 
    891 	fio = getfiobyfd(pu, fd);
    892 	if (fio == NULL) {
    893 		errno = ENXIO;
    894 		return -1;
    895 	}
    896 
    897 	i = 0;
    898 	if (what & PUFFS_FBIO_READ && fio->rwait == 0) {
    899 		EV_SET(&kev[0], fd,
    900 		    EVFILT_READ, EV_DISABLE, 0, 0, (uintptr_t)fio);
    901 		i++;
    902 	}
    903 	if (what & PUFFS_FBIO_WRITE && fio->stat & FIO_WR && fio->wwait == 0) {
    904 		EV_SET(&kev[1], fd,
    905 		    EVFILT_WRITE, EV_DISABLE, 0, 0, (uintptr_t)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_nfds--;
   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