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      1 /*  $NetBSD: msg.c,v 1.27 2025/01/07 17:39:45 andvar Exp $ */
      2 
      3 /*-
      4  *  Copyright (c) 2010 Emmanuel Dreyfus. All rights reserved.
      5  *
      6  *  Redistribution and use in source and binary forms, with or without
      7  *  modification, are permitted provided that the following conditions
      8  *  are met:
      9  *  1. Redistributions of source code must retain the above copyright
     10  *     notice, this list of conditions and the following disclaimer.
     11  *  2. Redistributions in binary form must reproduce the above copyright
     12  *     notice, this list of conditions and the following disclaimer in the
     13  *     documentation and/or other materials provided with the distribution.
     14  *
     15  *  THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     16  *  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     17  *  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     18  *  PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     19  *  BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     20  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     21  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     22  *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     23  *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     24  *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     25  *  POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include <stdio.h>
     29 #include <stdlib.h>
     30 #include <unistd.h>
     31 #include <err.h>
     32 #include <errno.h>
     33 #include <string.h>
     34 #include <sysexits.h>
     35 #include <syslog.h>
     36 #include <paths.h>
     37 #include <puffs.h>
     38 #include <limits.h>
     39 #include <sys/types.h>
     40 #include <sys/socket.h>
     41 #include <sys/un.h>
     42 #include <machine/vmparam.h>
     43 
     44 #include "perfused.h"
     45 
     46 static int xchg_pb_inloop(struct puffs_usermount *a, struct puffs_framebuf *,
     47 	int, enum perfuse_xchg_pb_reply);
     48 static int xchg_pb_early(struct puffs_usermount *a, struct puffs_framebuf *,
     49 	int, enum perfuse_xchg_pb_reply);
     50 
     51 int
     52 perfused_open_sock(void)
     53 {
     54 	int s;
     55 	struct sockaddr_un sun;
     56 	const struct sockaddr *sa;
     57 	uint32_t opt;
     58 	int sock_type = SOCK_SEQPACKET;
     59 
     60 	(void)unlink(_PATH_FUSE);
     61 
     62 	/*
     63 	 * Try SOCK_SEQPACKET and fallback to SOCK_DGRAM
     64 	 * if unavaible
     65 	 */
     66 	if ((s = socket(PF_LOCAL, SOCK_SEQPACKET, 0)) == -1) {
     67 		warnx("SEQPACKET local sockets unavailable, using less "
     68 		      "reliable DGRAM sockets. Expect file operation hangs.");
     69 
     70 		sock_type = SOCK_DGRAM;
     71 		if ((s = socket(PF_LOCAL, SOCK_DGRAM, 0)) == -1)
     72 			err(EX_OSERR, "socket failed");
     73 	}
     74 
     75 	sa = (const struct sockaddr *)(void *)&sun;
     76 	sun.sun_len = sizeof(sun);
     77 	sun.sun_family = AF_LOCAL;
     78 	(void)strcpy(sun.sun_path, _PATH_FUSE);
     79 
     80 	/*
     81 	 * Set a buffer length large enough so that a few FUSE packets
     82 	 * will fit.
     83 	 */
     84 	opt = perfuse_bufvar_from_env("PERFUSE_BUFSIZE", 16 * FUSE_BUFSIZE);
     85 	if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, &opt, sizeof(opt)) != 0)
     86 		DWARN("%s: setsockopt SO_SNDBUF = %d failed", __func__, opt);
     87 
     88 	if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)) != 0)
     89 		DWARN("%s: setsockopt SO_RCVBUF = %d failed", __func__, opt);
     90 
     91 	/*
     92 	 * Request peer credentials
     93 	 */
     94 	opt = 1;
     95 	if (setsockopt(s, SOL_LOCAL, LOCAL_CREDS, &opt, sizeof(opt)) != 0)
     96 		DWARN("%s: setsockopt LOCAL_CREDS failed", __func__);
     97 
     98 	if (bind(s, sa, (socklen_t )sun.sun_len) == -1)
     99 		err(EX_OSERR, "cannot open \"%s\" socket", _PATH_FUSE);
    100 
    101 	if (sock_type == SOCK_DGRAM) {
    102 		if (connect(s, sa, (socklen_t )sun.sun_len) == -1)
    103 			err(EX_OSERR, "cannot open \"%s\" socket", _PATH_FUSE);
    104 	}
    105 
    106 	return s;
    107 }
    108 
    109 
    110 void *
    111 perfused_recv_early(int fd, struct sockcred *sockcred, size_t sockcred_len)
    112 {
    113 	struct fuse_out_header foh;
    114 	size_t len;
    115 	char *buf;
    116 	struct msghdr msg;
    117 	char cmsg_buf[sizeof(struct cmsghdr) + SOCKCREDSIZE(NGROUPS_MAX)];
    118 	struct cmsghdr *cmsg = (struct cmsghdr *)(void *)&cmsg_buf;
    119 	struct sockcred *sc = (struct sockcred *)(void *)(cmsg + 1);
    120 	struct iovec iov;
    121 
    122 	len = sizeof(foh);
    123 
    124 	/*
    125 	 * We use the complicated recvmsg because we want peer creds.
    126 	 */
    127 	iov.iov_base = &foh;
    128 	iov.iov_len = len;
    129 	msg.msg_name = NULL;
    130 	msg.msg_namelen = 0;
    131 	msg.msg_iov = &iov;
    132 	msg.msg_iovlen = 1;
    133 	msg.msg_control = cmsg;
    134 	msg.msg_controllen = sizeof(cmsg_buf);
    135 	msg.msg_flags = 0;
    136 
    137 	if (recvmsg(fd, &msg, MSG_NOSIGNAL|MSG_PEEK) != (ssize_t)len) {
    138 		DWARN("short recv (header)");
    139 		return NULL;
    140 	}
    141 
    142 	if (cmsg->cmsg_type != SCM_CREDS) {
    143 		DWARNX("No SCM_CREDS");
    144 		return NULL;
    145 	}
    146 
    147 	if (sockcred != NULL)
    148 		(void)memcpy(sockcred, sc,
    149 			     MIN(cmsg->cmsg_len - sizeof(*cmsg), sockcred_len));
    150 
    151 
    152 	len = foh.len;
    153 	if ((buf = malloc(len)) == NULL)
    154 		err(EX_OSERR, "malloc(%zd) failed", len);
    155 
    156 	if (recv(fd, buf, len, MSG_NOSIGNAL) != (ssize_t)len) {
    157 		DWARN("short recv (frame)");
    158 		return NULL;
    159 	}
    160 
    161 	return buf;
    162 }
    163 
    164 
    165 perfuse_msg_t *
    166 perfused_new_pb (struct puffs_usermount *pu, puffs_cookie_t opc, int opcode,
    167     size_t payload_len, const struct puffs_cred *cred)
    168 {
    169 	struct puffs_framebuf *pb;
    170 	struct fuse_in_header *fih;
    171 	struct puffs_cc *pcc;
    172 	uint64_t nodeid;
    173 	void *data;
    174 	size_t len;
    175 
    176 	if ((pb = puffs_framebuf_make()) == NULL)
    177 		DERR(EX_OSERR, "puffs_framebuf_make failed");
    178 
    179 	len = payload_len + sizeof(*fih);
    180 	if (opc != 0)
    181 		nodeid = perfuse_get_nodeid(pu, opc);
    182 	else
    183 		nodeid = PERFUSE_UNKNOWN_NODEID;
    184 
    185 	if (puffs_framebuf_reserve_space(pb, len) != 0)
    186 		DERR(EX_OSERR, "puffs_framebuf_reserve_space failed");
    187 
    188 	if (puffs_framebuf_getwindow(pb, 0, &data, &len) != 0)
    189 		DERR(EX_SOFTWARE, "puffs_framebuf_getwindow failed");
    190 	if (len != payload_len + sizeof(*fih))
    191 		DERR(EX_SOFTWARE, "puffs_framebuf_getwindow short len");
    192 
    193 	(void)memset(data, 0, len);
    194 	fih = (struct fuse_in_header *)data;
    195 	fih->len = (uint32_t)len;
    196 	fih->opcode = opcode;
    197 	fih->unique = perfuse_next_unique(pu);
    198 	fih->nodeid = nodeid;
    199 	fih->pid = 0;
    200 
    201 	/*
    202 	 * NULL creds is taken as FUSE root. This currently happens for:
    203 	 * - mount	root cred assumed
    204 	 * - umount	root cred assumed
    205 	 * - inactive	kernel cred used
    206 	 * - statvfs	root cred assumed
    207 	 * - poll	checks have been done at open() time
    208 	 * - addvlock	checks have been done at open() time
    209 	 */
    210 	if ((cred != NULL) && !puffs_cred_isjuggernaut(cred)) {
    211 		if (puffs_cred_getuid(cred, &fih->uid) != 0)
    212 			DERRX(EX_SOFTWARE, "puffs_cred_getuid failed");
    213 		if (puffs_cred_getgid(cred, &fih->gid) != 0)
    214 			DERRX(EX_SOFTWARE, "puffs_cred_getgid failed");
    215 	} else {
    216 		fih->uid = (uid_t)0;
    217 		fih->gid = (gid_t)0;
    218 	}
    219 
    220 	if ((pcc = puffs_cc_getcc(pu)) != NULL)
    221 		(void)puffs_cc_getcaller(pcc, (pid_t *)&fih->pid, NULL);
    222 
    223 	return (perfuse_msg_t *)(void *)pb;
    224 }
    225 
    226 /*
    227  * framebuf send/receive primitives based on pcc are
    228  * not available until puffs mainloop is entered.
    229  * This xchg_pb_inloop() variant allow early communication.
    230  */
    231 static int
    232 xchg_pb_early(struct puffs_usermount *pu, struct puffs_framebuf *pb, int fd,
    233     enum perfuse_xchg_pb_reply reply)
    234 {
    235 	int done;
    236 	int error;
    237 
    238 	done = 0;
    239 	while (done == 0) {
    240 		if ((error = perfused_writeframe(pu, pb, fd, &done)) != 0)
    241 			return error;
    242 	}
    243 
    244 	if (reply == no_reply) {
    245 		puffs_framebuf_destroy(pb);
    246 		return 0;
    247 	} else {
    248 		puffs_framebuf_recycle(pb);
    249 	}
    250 
    251 	done = 0;
    252 	while (done == 0) {
    253 		if ((error = perfused_readframe(pu, pb, fd, &done)) != 0)
    254 			return error;
    255 	}
    256 
    257 	return 0;
    258 }
    259 
    260 static int
    261 xchg_pb_inloop(struct puffs_usermount *pu, struct puffs_framebuf *pb, int fd,
    262     enum perfuse_xchg_pb_reply reply)
    263 {
    264 	struct puffs_cc *pcc;
    265 	int error;
    266 
    267 	if (reply == no_reply) {
    268 		error = puffs_framev_enqueue_justsend(pu, fd, pb, 0, 0);
    269 	} else {
    270 		pcc = puffs_cc_getcc(pu);
    271 		error = puffs_framev_enqueue_cc(pcc, fd, pb, 0);
    272 	}
    273 
    274 	return error;
    275 }
    276 
    277 int
    278 perfused_xchg_pb(struct puffs_usermount *pu, perfuse_msg_t *pm,
    279     size_t expected_len, enum perfuse_xchg_pb_reply reply)
    280 {
    281 	struct puffs_framebuf *pb = (struct puffs_framebuf *)(void *)pm;
    282 	int fd;
    283 	int error;
    284 	struct fuse_out_header *foh;
    285 #ifdef PERFUSE_DEBUG
    286 	struct fuse_in_header *fih;
    287 	uint64_t nodeid;
    288 	int opcode;
    289 	uint64_t unique_in;
    290 	uint64_t unique_out;
    291 
    292 	fih = perfused_get_inhdr(pm);
    293 	unique_in = fih->unique;
    294 	nodeid = fih->nodeid;
    295 	opcode = fih->opcode;
    296 
    297 	if (perfuse_diagflags & PDF_FUSE)
    298 		DPRINTF("> unique = %"PRId64", nodeid = %"PRId64", "
    299 			"opcode = %s (%d)\n",
    300 			unique_in, nodeid, perfuse_opname(opcode), opcode);
    301 
    302 	if (perfuse_diagflags & PDF_DUMP)
    303 		perfused_hexdump((char *)fih, fih->len);
    304 
    305 #endif /* PERFUSE_DEBUG */
    306 
    307 	fd = (int)(intptr_t)perfuse_getspecific(pu);
    308 
    309 	if (perfuse_inloop(pu))
    310 		error = xchg_pb_inloop(pu, pb, fd, reply);
    311 	else
    312 		error = xchg_pb_early(pu, pb, fd, reply);
    313 
    314 	if (error)
    315 		DERR(EX_SOFTWARE, "xchg_pb failed");
    316 
    317 	if (reply == no_reply)
    318 		return 0;
    319 
    320 	foh = perfused_get_outhdr((perfuse_msg_t *)(void *)pb);
    321 #ifdef PERFUSE_DEBUG
    322 	unique_out = foh->unique;
    323 
    324 	if (perfuse_diagflags & PDF_FUSE)
    325 		DPRINTF("< unique = %"PRId64", nodeid = %"PRId64", "
    326 			"opcode = %s (%d), "
    327 			"error = %d\n", unique_out, nodeid,
    328 			perfuse_opname(opcode), opcode, foh->error);
    329 
    330 	if (perfuse_diagflags & PDF_DUMP)
    331 		perfused_hexdump((char *)foh, foh->len);
    332 
    333 	if (unique_in != unique_out) {
    334 		printf("%s: packet mismatch unique %"PRId64" vs %"PRId64"\n",
    335 		     __func__, unique_in, unique_out);
    336 		abort();
    337 		errx(EX_SOFTWARE, "%s: packet mismatch unique "
    338 		     "%"PRId64" vs %"PRId64"\n",
    339 		     __func__, unique_in, unique_out);
    340 	}
    341 #endif /* PERFUSE_DEBUG */
    342 
    343 	if ((expected_len != PERFUSE_UNSPEC_REPLY_LEN) &&
    344 	    (foh->len - sizeof(*foh) < expected_len) &&
    345 	    (foh->error == 0)) {
    346 		DERRX(EX_PROTOCOL,
    347 		     "Unexpected short reply: received %zd bytes, expected %zd",
    348 		     foh->len - sizeof(*foh), expected_len);
    349 	}
    350 
    351 	if ((expected_len != 0) &&
    352 	    (foh->len - sizeof(*foh) > expected_len))
    353 		DWARNX("Unexpected long reply");
    354 
    355 	/*
    356 	 * Negative Linux errno...
    357 	 */
    358 	if (foh->error <= 0) {
    359 		foh->error = -foh->error;
    360 	} else {
    361 		DWARNX("FUSE resturns positive errno %d", foh->error);
    362 		foh->error = 0;
    363 	}
    364 
    365 	return foh->error;
    366 }
    367 
    368 
    369 struct fuse_in_header *
    370 perfused_get_inhdr(perfuse_msg_t *pm)
    371 {
    372 	struct puffs_framebuf *pb;
    373 	struct fuse_in_header *fih;
    374 	void *hdr;
    375 	size_t len;
    376 
    377 	pb = (struct puffs_framebuf *)(void *)pm;
    378 	len = sizeof(*fih);
    379 	if (puffs_framebuf_getwindow(pb, 0, &hdr, &len) != 0)
    380 		DERR(EX_SOFTWARE, "puffs_framebuf_getwindow failed");
    381 	if (len != sizeof(*fih))
    382 		DERR(EX_SOFTWARE, "puffs_framebuf_getwindow short header");
    383 
    384 	fih = (struct fuse_in_header *)hdr;
    385 
    386 	return fih;
    387 }
    388 
    389 struct fuse_out_header *
    390 perfused_get_outhdr(perfuse_msg_t *pm)
    391 {
    392 	struct puffs_framebuf *pb;
    393 	struct fuse_out_header *foh;
    394 	void *hdr;
    395 	size_t len;
    396 
    397 	pb = (struct puffs_framebuf *)(void *)pm;
    398 	len = sizeof(*foh);
    399 	if (puffs_framebuf_getwindow(pb, 0, &hdr, &len) != 0)
    400 		DERR(EX_SOFTWARE, "puffs_framebuf_getwindow failed");
    401 	if (len != sizeof(*foh))
    402 		DERR(EX_SOFTWARE, "puffs_framebuf_getwindow short header");
    403 
    404 	foh = (struct fuse_out_header *)hdr;
    405 
    406 	return foh;
    407 }
    408 
    409 char *
    410 perfused_get_inpayload(perfuse_msg_t *pm)
    411 {
    412 	struct puffs_framebuf *pb;
    413 	struct fuse_in_header *fih;
    414 	void *hdr;
    415 	void *payload;
    416 	size_t len;
    417 
    418 	pb = (struct puffs_framebuf *)(void *)pm;
    419 	len = sizeof(*fih);
    420 	if (puffs_framebuf_getwindow(pb, 0, &hdr, &len) != 0)
    421 		DERR(EX_SOFTWARE, "puffs_framebuf_getwindow failed");
    422 	if (len != sizeof(*fih))
    423 		DERR(EX_SOFTWARE, "puffs_framebuf_getwindow short header");
    424 
    425 	fih = (struct fuse_in_header *)hdr;
    426 
    427 	len = fih->len - sizeof(*fih);
    428 	if (puffs_framebuf_getwindow(pb, sizeof(*fih), &payload, &len) != 0)
    429 		DERR(EX_SOFTWARE, "puffs_framebuf_getwindow failed");
    430 	if (len != fih->len - sizeof(*fih))
    431 		DERR(EX_SOFTWARE, "puffs_framebuf_getwindow short header");
    432 
    433 	return (char *)payload;
    434 }
    435 
    436 char *
    437 perfused_get_outpayload(perfuse_msg_t *pm)
    438 {
    439 	struct puffs_framebuf *pb;
    440 	struct fuse_out_header *foh;
    441 	void *hdr;
    442 	void *payload;
    443 	size_t len;
    444 
    445 	pb = (struct puffs_framebuf *)(void *)pm;
    446 	len = sizeof(*foh);
    447 	if (puffs_framebuf_getwindow(pb, 0, &hdr, &len) != 0)
    448 		DERR(EX_SOFTWARE, "puffs_framebuf_getwindow failed");
    449 	if (len != sizeof(*foh))
    450 		DERR(EX_SOFTWARE, "puffs_framebuf_getwindow short header");
    451 
    452 	foh = (struct fuse_out_header *)hdr;
    453 
    454 	len = foh->len - sizeof(*foh);
    455 	if (puffs_framebuf_getwindow(pb, sizeof(*foh), &payload, &len) != 0)
    456 		DERR(EX_SOFTWARE, "puffs_framebuf_getwindow failed");
    457 	if (len != foh->len - sizeof(*foh))
    458 		DERR(EX_SOFTWARE, "puffs_framebuf_getwindow short header");
    459 
    460 	return (char *)payload;
    461 }
    462 
    463 #define PUFFS_FRAMEBUF_GETWINDOW(pb, offset, data, len) 		     \
    464 	do {								     \
    465 		int pfg_error;						     \
    466 		size_t pfg_len = *(len);				     \
    467 									     \
    468 		pfg_error = puffs_framebuf_getwindow(pb, offset, data, len); \
    469 		if (pfg_error != 0)					     \
    470 			DERR(EX_SOFTWARE, "puffs_framebuf_getwindow failed");\
    471 									     \
    472 		if (*(len) != pfg_len)					     \
    473 			DERRX(EX_SOFTWARE, "puffs_framebuf_getwindow size"); \
    474 	} while (0 /* CONSTCOND */);
    475 
    476 /* ARGSUSED0 */
    477 int
    478 perfused_readframe(struct puffs_usermount *pu, struct puffs_framebuf *pufbuf,
    479     int fd, int *done)
    480 {
    481 	struct fuse_out_header foh;
    482 	size_t len;
    483 	ssize_t readen;
    484 	void *data;
    485 
    486 	/*
    487 	 * Read the header
    488 	 */
    489 	len = sizeof(foh);
    490 	PUFFS_FRAMEBUF_GETWINDOW(pufbuf, 0, &data, &len);
    491 
    492 	switch (readen = recv(fd, data, len, MSG_NOSIGNAL|MSG_PEEK)) {
    493 	case 0:
    494 		DPRINTF("Filesystem exit\n");
    495 		/* NOTREACHED */
    496 		exit(0);
    497 		break;
    498 	case -1:
    499 		if (errno == EAGAIN)
    500 			return 0;
    501 		DWARN("%s: recv returned -1", __func__);
    502 		return errno;
    503 		/* NOTREACHED */
    504 		break;
    505 	default:
    506 		break;
    507 	}
    508 
    509 #ifdef PERFUSE_DEBUG
    510 	if (readen != (ssize_t)len)
    511 		DERRX(EX_SOFTWARE, "%s: short recv %zd/%zd",
    512 		      __func__, readen, len);
    513 #endif
    514 
    515 	/*
    516 	 * We have a header, get remaining length to read
    517 	 */
    518 	if (puffs_framebuf_getdata_atoff(pufbuf, 0, &foh, sizeof(foh)) != 0)
    519 		DERR(EX_SOFTWARE, "puffs_framebuf_getdata_atoff failed");
    520 
    521 	len = foh.len;
    522 
    523 #ifdef PERFUSE_DEBUG
    524 	if (len > (size_t)FUSE_BUFSIZE)
    525 		DERRX(EX_SOFTWARE, "%s: foh.len = %zu", __func__, len);
    526 #endif
    527 
    528 	/*
    529 	 * This is time to reserve space.
    530 	 */
    531 	if (puffs_framebuf_reserve_space(pufbuf, len) == -1)
    532 		DERR(EX_OSERR, "puffs_framebuf_reserve_space failed");
    533 
    534 	/*
    535 	 * And read the remaining data
    536 	 */
    537 	PUFFS_FRAMEBUF_GETWINDOW(pufbuf, 0, &data, &len);
    538 
    539 	switch (readen = recv(fd, data, len, MSG_NOSIGNAL)) {
    540 	case 0:
    541 		DWARNX("%s: recv returned 0", __func__);
    542 		perfused_panic();
    543 	case -1:
    544 		if (errno == EAGAIN)
    545 			return 0;
    546 		DWARN("%s: recv returned -1", __func__);
    547 		return errno;
    548 	default:
    549 		break;
    550 	}
    551 
    552 #ifdef PERFUSE_DEBUG
    553 	if (readen != (ssize_t)len)
    554 		DERRX(EX_SOFTWARE, "%s: short recv %zd/%zd",
    555 		      __func__, readen, len);
    556 #endif
    557 
    558 	*done = 1;
    559 	return 0;
    560 }
    561 
    562 /* ARGSUSED0 */
    563 int
    564 perfused_writeframe(struct puffs_usermount *pu, struct puffs_framebuf *pufbuf,
    565     int fd, int *done)
    566 {
    567 	size_t len;
    568 	ssize_t written;
    569 	void *data;
    570 
    571 	len = puffs_framebuf_tellsize(pufbuf);
    572 	PUFFS_FRAMEBUF_GETWINDOW(pufbuf, 0, &data, &len);
    573 
    574 	switch (written = send(fd, data, len, MSG_NOSIGNAL)) {
    575 	case 0:
    576 #ifdef PERFUSE_DEBUG
    577 		DERRX(EX_SOFTWARE, "%s: send returned 0", __func__);
    578 #else
    579 		return ECONNRESET;
    580 #endif
    581 		/* NOTREACHED */
    582 		break;
    583 	case -1:
    584 		DWARN("%s: send returned -1, errno = %d", __func__, errno);
    585 		switch(errno) {
    586 		case EAGAIN:
    587 		case ENOBUFS:
    588 		case EMSGSIZE:
    589 			return 0;
    590 			break;
    591 		case EPIPE:
    592 			perfused_panic();
    593 			/* NOTREACHED */
    594 			break;
    595 		default:
    596 			return errno;
    597 			break;
    598 		}
    599 		/* NOTREACHED */
    600 		break;
    601 	default:
    602 		break;
    603 	}
    604 
    605 #ifdef PERFUSE_DEBUG
    606 	if (written != (ssize_t)len)
    607 		DERRX(EX_SOFTWARE, "%s: short send %zd/%zd",
    608 		      __func__, written, len);
    609 #endif
    610 
    611 	*done = 1;
    612 	return 0;
    613 }
    614 
    615 /* ARGSUSED0 */
    616 int
    617 perfused_cmpframe(struct puffs_usermount *pu, struct puffs_framebuf *pb1,
    618     struct puffs_framebuf *pb2, int *match)
    619 {
    620 	struct fuse_in_header *fih;
    621 	struct fuse_out_header *foh;
    622 	uint64_t unique_in;
    623 	uint64_t unique_out;
    624 	size_t len;
    625 
    626 	len = sizeof(*fih);
    627 	PUFFS_FRAMEBUF_GETWINDOW(pb1, 0, (void **)(void *)&fih, &len);
    628 	unique_in = fih->unique;
    629 
    630 	len = sizeof(*foh);
    631 	PUFFS_FRAMEBUF_GETWINDOW(pb2, 0, (void **)(void *)&foh, &len);
    632 	unique_out = foh->unique;
    633 
    634 	return unique_in != unique_out;
    635 }
    636 
    637 /* ARGSUSED0 */
    638 void
    639 perfused_gotframe(struct puffs_usermount *pu, struct puffs_framebuf *pb)
    640 {
    641 	struct fuse_out_header *foh;
    642 	size_t len;
    643 
    644 	len = sizeof(*foh);
    645 	PUFFS_FRAMEBUF_GETWINDOW(pb, 0, (void **)(void *)&foh, &len);
    646 
    647 	DWARNX("Unexpected frame: unique = %"PRId64", error = %d",
    648 	       foh->unique, foh->error);
    649 #ifdef PERFUSE_DEBUG
    650 	perfused_hexdump((char *)(void *)foh, foh->len);
    651 #endif
    652 
    653 	return;
    654 }
    655 
    656 void
    657 perfused_fdnotify(struct puffs_usermount *pu, int fd, int what)
    658 {
    659 	if (fd != (int)(intptr_t)perfuse_getspecific(pu))
    660 		DERRX(EX_SOFTWARE, "%s: unexpected notification for fd = %d",
    661 		      __func__, fd);
    662 
    663 	if ((what != PUFFS_FBIO_READ) && (what != PUFFS_FBIO_WRITE))
    664 		DERRX(EX_SOFTWARE, "%s: unexpected notification what = 0x%x",
    665 		      __func__, what);
    666 
    667 	if (perfuse_unmount(pu) != 0)
    668 		DWARN("unmount() failed");
    669 
    670 	if (shutdown(fd, SHUT_RDWR) != 0)
    671 		DWARN("shutdown() failed");
    672 
    673 	if (perfuse_diagflags & PDF_MISC)
    674 		DPRINTF("Exit");
    675 
    676 	exit(0);
    677 }
    678 
    679 void
    680 perfused_umount(struct puffs_usermount *pu)
    681 {
    682 	int fd;
    683 
    684 	fd = (int)(intptr_t)perfuse_getspecific(pu);
    685 
    686 	if (shutdown(fd, SHUT_RDWR) != 0)
    687 		DWARN("shutdown() failed");
    688 
    689 	if (perfuse_diagflags & PDF_MISC)
    690 		DPRINTF("unmount");
    691 
    692 	return;
    693 }
    694