xref: /netbsd-src/usr.sbin/puffs/mount_sysctlfs/sysctlfs.c (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /*	$NetBSD: sysctlfs.c,v 1.17 2012/11/04 22:47:21 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2006, 2007  Antti Kantee.  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 AUTHOR ``AS IS'' AND ANY EXPRESS
16  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 /*
29  * sysctlfs: mount sysctls as a file system tree.  Supports query and
30  * modify of nodes in the sysctl namespace in addition to namespace
31  * traversal.
32  */
33 
34 #include <sys/cdefs.h>
35 #ifndef lint
36 __RCSID("$NetBSD: sysctlfs.c,v 1.17 2012/11/04 22:47:21 christos Exp $");
37 #endif /* !lint */
38 
39 #include <sys/types.h>
40 #include <sys/sysctl.h>
41 
42 #include <stdio.h>
43 #include <assert.h>
44 #include <err.h>
45 #include <errno.h>
46 #include <mntopts.h>
47 #include <paths.h>
48 #include <puffs.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <util.h>
53 
54 #ifdef RUMP_ACTION
55 #include <rump/rump.h>
56 #include <rump/rump_syscalls.h>
57 
58 #define sysctl(a,b,c,d,e,f) rump_sys___sysctl(a,b,c,d,e,f)
59 #endif
60 
61 PUFFSOP_PROTOS(sysctlfs)
62 
63 struct sfsnode {
64 	int sysctl_flags;
65 	ino_t myid;
66 };
67 
68 #define SFSPATH_DOTDOT 0
69 #define SFSPATH_NORMAL 1
70 
71 #define N_HIERARCHY 10
72 typedef int SfsName[N_HIERARCHY];
73 
74 struct sfsfid {
75 	int len;
76 	SfsName path;
77 };
78 
79 static struct sfsnode rn;
80 static SfsName sname_root;
81 static struct timespec fstime;
82 
83 static ino_t nextid = 3;
84 static mode_t fileperms;
85 static uid_t fileuid;
86 static gid_t filegid;
87 
88 static int rflag;
89 
90 #define ISADIR(a) ((SYSCTL_TYPE(a->sysctl_flags) == CTLTYPE_NODE))
91 #define SFS_MAXFILE 32768
92 #define SFS_NODEPERDIR 128
93 
94 static int sysctlfs_domount(struct puffs_usermount *);
95 
96 /*
97  * build paths.  doesn't support rename (but neither does the fs)
98  */
99 static int
100 sysctlfs_pathbuild(struct puffs_usermount *pu,
101 	const struct puffs_pathobj *parent, const struct puffs_pathobj *comp,
102 	size_t offset, struct puffs_pathobj *res)
103 {
104 	SfsName *sname;
105 	size_t clen;
106 
107 	assert(parent->po_len < N_HIERARCHY); /* code uses +1 */
108 
109 	sname = malloc(sizeof(SfsName));
110 	assert(sname != NULL);
111 
112 	clen = parent->po_len;
113 	if (comp->po_len == SFSPATH_DOTDOT) {
114 		assert(clen != 0);
115 		clen--;
116 	}
117 
118 	memcpy(sname, parent->po_path, clen * sizeof(int));
119 
120 	res->po_path = sname;
121 	res->po_len = clen;
122 
123 	return 0;
124 }
125 
126 static int
127 sysctlfs_pathtransform(struct puffs_usermount *pu,
128 	const struct puffs_pathobj *p, const struct puffs_cn *pcn,
129 	struct puffs_pathobj *res)
130 {
131 
132 	res->po_path = NULL;
133 	/*
134 	 * XXX: overload.  prevents us from doing rename, but the fs
135 	 * (and sysctl(3)) doesn't support it, so no biggie
136 	 */
137 	if (PCNISDOTDOT(pcn)) {
138 		res->po_len = SFSPATH_DOTDOT;
139 	}else {
140 		res->po_len = SFSPATH_NORMAL;
141 	}
142 
143 	return 0;
144 }
145 
146 static int
147 sysctlfs_pathcmp(struct puffs_usermount *pu, struct puffs_pathobj *po1,
148 	struct puffs_pathobj *po2, size_t clen, int checkprefix)
149 {
150 
151 	if (memcmp(po1->po_path, po2->po_path, clen * sizeof(int)) == 0)
152 		return 0;
153 	return 1;
154 }
155 
156 static void
157 sysctlfs_pathfree(struct puffs_usermount *pu, struct puffs_pathobj *po)
158 {
159 
160 	free(po->po_path);
161 }
162 
163 static struct puffs_node *
164 getnode(struct puffs_usermount *pu, struct puffs_pathobj *po, int nodetype)
165 {
166 	struct sysctlnode sn[SFS_NODEPERDIR];
167 	struct sysctlnode qnode;
168 	struct puffs_node *pn;
169 	struct sfsnode *sfs;
170 	SfsName myname, *sname;
171 	size_t sl, i;
172 
173 	/*
174 	 * Check if we need to create a new in-memory node or if we
175 	 * already have one for this path.  Shortcut for the rootnode.
176 	 * Also, memcmp against zero-length would be quite true always.
177 	 */
178 	if (po->po_len == 0)
179 		pn = puffs_getroot(pu);
180 	else
181 		pn = puffs_pn_nodewalk(pu, puffs_path_walkcmp, po);
182 
183 	if (pn == NULL) {
184 		/*
185 		 * don't know nodetype?  query...
186 		 *
187 		 * XXX1: nothing really guarantees 0 is an invalid nodetype
188 		 * XXX2: is there really no easier way of doing this?  we
189 		 *       know the whole mib path
190 		 */
191 		if (!nodetype) {
192 			sname = po->po_path;
193 			memcpy(myname, po->po_path, po->po_len * sizeof(int));
194 
195 			memset(&qnode, 0, sizeof(qnode));
196 			qnode.sysctl_flags = SYSCTL_VERSION;
197 			myname[po->po_len-1] = CTL_QUERY;
198 
199 			sl = sizeof(sn);
200 			if (sysctl(myname, po->po_len, sn, &sl,
201 			    &qnode, sizeof(qnode)) == -1)
202 				abort();
203 
204 			for (i = 0; i < sl / sizeof(struct sysctlnode); i++) {
205 				 if (sn[i].sysctl_num==(*sname)[po->po_len-1]) {
206 					nodetype = sn[i].sysctl_flags;
207 					break;
208 				}
209 			}
210 			if (!nodetype)
211 				return NULL;
212 		}
213 
214 		sfs = emalloc(sizeof(struct sfsnode));
215 		sfs->sysctl_flags = nodetype;
216 		sfs->myid = nextid++;
217 
218 		pn = puffs_pn_new(pu, sfs);
219 		assert(pn);
220 	}
221 
222 	return pn;
223 }
224 
225 int
226 main(int argc, char *argv[])
227 {
228 	struct puffs_usermount *pu;
229 	struct puffs_ops *pops;
230 	mntoptparse_t mp;
231 	int mntflags, pflags;
232 	int detach;
233 	int ch;
234 
235 	setprogname(argv[0]);
236 
237 	if (argc < 2)
238 		errx(1, "usage: %s sysctlfs [-o mntopts] mountpath",
239 		    getprogname());
240 
241 	mntflags = pflags = 0;
242 	detach = 1;
243 	while ((ch = getopt(argc, argv, "o:rs")) != -1) {
244 		switch (ch) {
245 		case 'o':
246 			mp = getmntopts(optarg, puffsmopts, &mntflags, &pflags);
247 			if (mp == NULL)
248 				err(1, "getmntopts");
249 			freemntopts(mp);
250 			break;
251 		case 'r':
252 			rflag = 1;
253 			break;
254 		case 's':
255 			detach = 0;
256 			break;
257 		}
258 	}
259 	argv += optind;
260 	argc -= optind;
261 	pflags |= PUFFS_FLAG_BUILDPATH | PUFFS_KFLAG_NOCACHE;
262 
263 	if (pflags & PUFFS_FLAG_OPDUMP)
264 		detach = 0;
265 
266 	if (argc != 2)
267 		errx(1, "usage: %s [-o mntopts] mountpath", getprogname());
268 
269 	PUFFSOP_INIT(pops);
270 
271 	PUFFSOP_SETFSNOP(pops, unmount);
272 	PUFFSOP_SETFSNOP(pops, sync);
273 	PUFFSOP_SETFSNOP(pops, statvfs);
274 	PUFFSOP_SET(pops, sysctlfs, fs, nodetofh);
275 	PUFFSOP_SET(pops, sysctlfs, fs, fhtonode);
276 
277 	PUFFSOP_SET(pops, sysctlfs, node, lookup);
278 	PUFFSOP_SET(pops, sysctlfs, node, getattr);
279 	PUFFSOP_SET(pops, sysctlfs, node, setattr);
280 	PUFFSOP_SET(pops, sysctlfs, node, readdir);
281 	PUFFSOP_SET(pops, sysctlfs, node, read);
282 	PUFFSOP_SET(pops, sysctlfs, node, write);
283 	PUFFSOP_SET(pops, puffs_genfs, node, reclaim);
284 
285 	pu = puffs_init(pops, _PATH_PUFFS, "sysctlfs", NULL, pflags);
286 	if (pu == NULL)
287 		err(1, "puffs_init");
288 
289 	puffs_set_pathbuild(pu, sysctlfs_pathbuild);
290 	puffs_set_pathtransform(pu, sysctlfs_pathtransform);
291 	puffs_set_pathcmp(pu, sysctlfs_pathcmp);
292 	puffs_set_pathfree(pu, sysctlfs_pathfree);
293 
294 	puffs_setfhsize(pu, sizeof(struct sfsfid), PUFFS_FHFLAG_NFSV3);
295 
296 	if (sysctlfs_domount(pu) != 0)
297 		errx(1, "domount");
298 
299 	if (detach)
300 		if (puffs_daemon(pu, 1, 1) == -1)
301 			err(1, "puffs_daemon");
302 
303 #ifdef RUMP_ACTION
304 	{
305 	extern int puffs_fakecc;
306 	puffs_fakecc = 1;
307 	rump_init();
308 	}
309 #endif
310 
311 	if (puffs_mount(pu, argv[1], mntflags, puffs_getroot(pu)) == -1)
312 		err(1, "puffs_mount");
313 	if (puffs_mainloop(pu) == -1)
314 		err(1, "mainloop");
315 
316 	return 0;
317 }
318 
319 static int
320 sysctlfs_domount(struct puffs_usermount *pu)
321 {
322 	struct puffs_pathobj *po_root;
323 	struct puffs_node *pn_root;
324 	struct timeval tv_now;
325 
326 	rn.myid = 2;
327 	rn.sysctl_flags = CTLTYPE_NODE;
328 
329 	gettimeofday(&tv_now, NULL);
330 	TIMEVAL_TO_TIMESPEC(&tv_now, &fstime);
331 
332 	pn_root = puffs_pn_new(pu, &rn);
333 	assert(pn_root != NULL);
334 	puffs_setroot(pu, pn_root);
335 
336 	po_root = puffs_getrootpathobj(pu);
337 	po_root->po_path = &sname_root;
338 	po_root->po_len = 0;
339 
340 	fileuid = geteuid();
341 	filegid = getegid();
342 
343 	if (fileuid == 0)
344 		fileperms = 0755;
345 	else
346 		fileperms = 0555;
347 
348 	return 0;
349 }
350 
351 int
352 sysctlfs_fs_fhtonode(struct puffs_usermount *pu, void *fid, size_t fidsize,
353 	struct puffs_newinfo *pni)
354 {
355 	struct puffs_pathobj po;
356 	struct puffs_node *pn;
357 	struct sfsnode *sfs;
358 	struct sfsfid *sfid;
359 
360 	sfid = fid;
361 
362 	po.po_len = sfid->len;
363 	po.po_path = &sfid->path;
364 
365 	pn = getnode(pu, &po, 0);
366 	if (pn == NULL)
367 		return EINVAL;
368 	sfs = pn->pn_data;
369 
370 	puffs_newinfo_setcookie(pni, pn);
371 	if (ISADIR(sfs))
372 		puffs_newinfo_setvtype(pni, VDIR);
373 	else
374 		puffs_newinfo_setvtype(pni, VREG);
375 
376 	return 0;
377 }
378 
379 int
380 sysctlfs_fs_nodetofh(struct puffs_usermount *pu, void *cookie,
381 	void *fid, size_t *fidsize)
382 {
383 	struct puffs_node *pn = cookie;
384 	struct sfsfid *sfid;
385 
386 	sfid = fid;
387 	sfid->len = PNPLEN(pn);
388 	memcpy(&sfid->path, PNPATH(pn), sfid->len * sizeof(int));
389 
390 	return 0;
391 }
392 
393 static void
394 getnodedata(struct sfsnode *sfs, struct puffs_pathobj *po,
395 	char *buf, size_t *bufsize)
396 {
397 	size_t sz;
398 	int error = 0;
399 
400 	assert(!ISADIR(sfs));
401 
402 	memset(buf, 0, *bufsize);
403 	switch (SYSCTL_TYPE(sfs->sysctl_flags)) {
404 	case CTLTYPE_BOOL: {
405 		bool b;
406 		sz = sizeof(bool);
407 		assert(sz <= *bufsize);
408 		if (sysctl(po->po_path, po->po_len, &b, &sz, NULL, 0) == -1) {
409 			error = errno;
410 			break;
411 		}
412 		if (rflag)
413 			memcpy(buf, &b, sz);
414 		else
415 			snprintf(buf, *bufsize, "%s", b ? "true" : "false");
416 		break;
417 	}
418 	case CTLTYPE_INT: {
419 		int i;
420 		sz = sizeof(int);
421 		assert(sz <= *bufsize);
422 		if (sysctl(po->po_path, po->po_len, &i, &sz, NULL, 0) == -1) {
423 			error = errno;
424 			break;
425 		}
426 		if (rflag)
427 			memcpy(buf, &i, sz);
428 		else
429 			snprintf(buf, *bufsize, "%d", i);
430 		break;
431 	}
432 	case CTLTYPE_QUAD: {
433 		quad_t q;
434 		sz = sizeof(q);
435 		assert(sz <= *bufsize);
436 		if (sysctl(po->po_path, po->po_len, &q, &sz, NULL, 0) == -1) {
437 			error = errno;
438 			break;
439 		}
440 		if (rflag)
441 			memcpy(buf, &q, sz);
442 		else
443 			snprintf(buf, *bufsize, "%" PRId64, q);
444 		break;
445 	}
446 	case CTLTYPE_STRUCT: {
447 		uint8_t snode[SFS_MAXFILE/2-1];
448 		unsigned i;
449 
450 		sz = sizeof(snode);
451 		assert(sz <= *bufsize);
452 		if (sysctl(po->po_path, po->po_len, snode, &sz, NULL, 0) == -1){
453 			error = errno;
454 			break;
455 		}
456 		if (rflag) {
457 			memcpy(buf, &snode, sz);
458 		} else {
459 			for (i = 0; i < sz && 2*i < *bufsize; i++) {
460 				sprintf(&buf[2*i], "%02x", snode[i]);
461 			}
462 			buf[2*i] = '\0';
463 		}
464 		break;
465 	}
466 	case CTLTYPE_STRING: {
467 		sz = *bufsize;
468 		assert(sz <= *bufsize);
469 		if (sysctl(po->po_path, po->po_len, buf, &sz, NULL, 0) == -1) {
470 			error = errno;
471 			break;
472 		}
473 		break;
474 	}
475 	default:
476 		snprintf(buf, *bufsize, "invalid sysctl CTLTYPE %d",
477 		    SYSCTL_TYPE(sfs->sysctl_flags));
478 		break;
479 	}
480 
481 	if (error) {
482 		*bufsize = 0;
483 		return;
484 	}
485 
486 	if (rflag)
487 		*bufsize = sz;
488 	else
489 		*bufsize = strlen(buf);
490 }
491 
492 static int
493 getlinks(struct sfsnode *sfs, struct puffs_pathobj *po)
494 {
495 	struct sysctlnode sn[SFS_NODEPERDIR];
496 	struct sysctlnode qnode;
497 	SfsName *sname;
498 	size_t sl;
499 
500 	if (!ISADIR(sfs))
501 		return 1;
502 
503 	memset(&qnode, 0, sizeof(qnode));
504 	sl = sizeof(sn);
505 	qnode.sysctl_flags = SYSCTL_VERSION;
506 	sname = po->po_path;
507 	(*sname)[po->po_len] = CTL_QUERY;
508 
509 	if (sysctl(*sname, po->po_len + 1, sn, &sl,
510 	    &qnode, sizeof(qnode)) == -1)
511 		return 0;
512 
513 	return (sl / sizeof(sn[0])) + 2;
514 }
515 
516 static int
517 getsize(struct sfsnode *sfs, struct puffs_pathobj *po)
518 {
519 	char buf[SFS_MAXFILE];
520 	size_t sz = sizeof(buf);
521 
522 	if (ISADIR(sfs))
523 		return getlinks(sfs, po) * 16; /* totally arbitrary */
524 
525 	getnodedata(sfs, po, buf, &sz);
526 	if (rflag)
527 		return sz;
528 	else
529 		return sz + 1; /* for \n, not \0 */
530 }
531 
532 int
533 sysctlfs_node_lookup(struct puffs_usermount *pu, void *opc,
534 	struct puffs_newinfo *pni, const struct puffs_cn *pcn)
535 {
536 	struct puffs_cn *p2cn = __UNCONST(pcn); /* XXX: fix the interface */
537 	struct sysctlnode sn[SFS_NODEPERDIR];
538 	struct sysctlnode qnode;
539 	struct puffs_node *pn_dir = opc;
540 	struct puffs_node *pn_new;
541 	struct sfsnode *sfs_dir = pn_dir->pn_data, *sfs_new;
542 	SfsName *sname = PCNPATH(pcn);
543 	size_t sl, i;
544 	int nodetype;
545 
546 	assert(ISADIR(sfs_dir));
547 
548 	/*
549 	 * If we're looking for dotdot, we already have the entire pathname
550 	 * in sname, courtesy of pathbuild, so we can skip this step.
551 	 */
552 	if (!PCNISDOTDOT(pcn)) {
553 		memset(&qnode, 0, sizeof(qnode));
554 		sl = SFS_NODEPERDIR * sizeof(struct sysctlnode);
555 		qnode.sysctl_flags = SYSCTL_VERSION;
556 		(*sname)[PCNPLEN(pcn)] = CTL_QUERY;
557 
558 		if (sysctl(*sname, PCNPLEN(pcn) + 1, sn, &sl,
559 		    &qnode, sizeof(qnode)) == -1)
560 			return ENOENT;
561 
562 		for (i = 0; i < sl / sizeof(struct sysctlnode); i++)
563 			if (strcmp(sn[i].sysctl_name, pcn->pcn_name) == 0)
564 				break;
565 		if (i == sl / sizeof(struct sysctlnode))
566 			return ENOENT;
567 
568 		(*sname)[PCNPLEN(pcn)] = sn[i].sysctl_num;
569 		p2cn->pcn_po_full.po_len++;
570 		nodetype = sn[i].sysctl_flags;
571 	} else
572 		nodetype = CTLTYPE_NODE;
573 
574 	pn_new = getnode(pu, &p2cn->pcn_po_full, nodetype);
575 	sfs_new = pn_new->pn_data;
576 
577 	puffs_newinfo_setcookie(pni, pn_new);
578 	if (ISADIR(sfs_new))
579 		puffs_newinfo_setvtype(pni, VDIR);
580 	else
581 		puffs_newinfo_setvtype(pni, VREG);
582 
583 	return 0;
584 }
585 
586 int
587 sysctlfs_node_getattr(struct puffs_usermount *pu, void *opc, struct vattr *va,
588 	const struct puffs_cred *pcr)
589 {
590 	struct puffs_node *pn = opc;
591 	struct sfsnode *sfs = pn->pn_data;
592 
593 	memset(va, 0, sizeof(struct vattr));
594 
595 	if (ISADIR(sfs)) {
596 		va->va_type = VDIR;
597 		va->va_mode = 0555;
598 	} else {
599 		va->va_type = VREG;
600 		va->va_mode = fileperms;
601 	}
602 	va->va_uid = fileuid;
603 	va->va_gid = filegid;
604 	va->va_nlink = getlinks(sfs, &pn->pn_po);
605 	va->va_fileid = sfs->myid;
606 	va->va_size = getsize(sfs, &pn->pn_po);
607 	va->va_gen = 1;
608 	va->va_rdev = PUFFS_VNOVAL;
609 	va->va_blocksize = 512;
610 	va->va_filerev = 1;
611 
612 	va->va_atime = va->va_mtime = va->va_ctime = va->va_birthtime = fstime;
613 
614 	return 0;
615 }
616 
617 int
618 sysctlfs_node_setattr(struct puffs_usermount *pu, void *opc,
619 	const struct vattr *va, const struct puffs_cred *pcr)
620 {
621 
622 	/* dummy, but required for write */
623 	/* XXX: we could return EOPNOTSUPP or something */
624 	return 0;
625 }
626 
627 int
628 sysctlfs_node_readdir(struct puffs_usermount *pu, void *opc,
629 	struct dirent *dent, off_t *readoff, size_t *reslen,
630 	const struct puffs_cred *pcr, int *eofflag,
631 	off_t *cookies, size_t *ncookies)
632 {
633 	struct sysctlnode sn[SFS_NODEPERDIR];
634 	struct sysctlnode qnode;
635 	struct puffs_node *pn_dir = opc;
636 	struct puffs_node *pn_res;
637 	struct puffs_pathobj po;
638 	struct sfsnode *sfs_dir = pn_dir->pn_data, *sfs_ent;
639 	SfsName *sname;
640 	size_t sl, i;
641 	enum vtype vt;
642 	ino_t id;
643 
644 	*ncookies = 0;
645 
646  again:
647 	if (*readoff == DENT_DOT || *readoff == DENT_DOTDOT) {
648 		puffs_gendotdent(&dent, sfs_dir->myid, *readoff, reslen);
649 		(*readoff)++;
650 		PUFFS_STORE_DCOOKIE(cookies, ncookies, *readoff);
651 		goto again;
652 	}
653 
654 	memset(&qnode, 0, sizeof(qnode));
655 	sl = SFS_NODEPERDIR * sizeof(struct sysctlnode);
656 	qnode.sysctl_flags = SYSCTL_VERSION;
657 	sname = PNPATH(pn_dir);
658 	(*sname)[PNPLEN(pn_dir)] = CTL_QUERY;
659 
660 	if (sysctl(*sname, PNPLEN(pn_dir) + 1, sn, &sl,
661 	    &qnode, sizeof(qnode)) == -1)
662 		return ENOENT;
663 
664 	po.po_path = sname;
665 	po.po_len = PNPLEN(pn_dir)+1;
666 
667 	for (i = DENT_ADJ(*readoff); i < sl / sizeof(struct sysctlnode); i++) {
668 		if (SYSCTL_TYPE(sn[i].sysctl_flags) == CTLTYPE_NODE)
669 			vt = VDIR;
670 		else
671 			vt = VREG;
672 
673 		/*
674 		 * check if the node exists.  if so, give it the real
675 		 * inode number.  otherwise just fake it.
676 		 */
677 		(*sname)[PNPLEN(pn_dir)] = sn[i].sysctl_num;
678 		pn_res = puffs_pn_nodewalk(pu, puffs_path_walkcmp, &po);
679 		if (pn_res) {
680 			sfs_ent = pn_res->pn_data;
681 			id = sfs_ent->myid;
682 		} else {
683 			id = nextid++;
684 		}
685 
686 		if (!puffs_nextdent(&dent, sn[i].sysctl_name, id,
687 		    puffs_vtype2dt(vt), reslen))
688 			return 0;
689 
690 		(*readoff)++;
691 		PUFFS_STORE_DCOOKIE(cookies, ncookies, *readoff);
692 	}
693 
694 	*eofflag = 1;
695 	return 0;
696 }
697 
698 int
699 sysctlfs_node_read(struct puffs_usermount *pu, void *opc, uint8_t *buf,
700 	off_t offset, size_t *resid, const struct puffs_cred *pcr,
701 	int ioflag)
702 {
703 	char localbuf[SFS_MAXFILE];
704 	struct puffs_node *pn = opc;
705 	struct sfsnode *sfs = pn->pn_data;
706 	size_t sz = sizeof(localbuf);
707 	int xfer;
708 
709 	if (ISADIR(sfs))
710 		return EISDIR;
711 
712 	getnodedata(sfs, &pn->pn_po, localbuf, &sz);
713 	if ((ssize_t)sz < offset)
714 		xfer = 0;
715 	else
716 		xfer = MIN(*resid, sz - offset);
717 
718 	if (xfer <= 0)
719 		return 0;
720 
721 	memcpy(buf, localbuf + offset, xfer);
722 	*resid -= xfer;
723 
724 	if (*resid && !rflag) {
725 		buf[xfer] = '\n';
726 		(*resid)--;
727 	}
728 
729 	return 0;
730 }
731 
732 int
733 sysctlfs_node_write(struct puffs_usermount *pu, void *opc, uint8_t *buf,
734 	off_t offset, size_t *resid, const struct puffs_cred *cred,
735 	int ioflag)
736 {
737 	struct puffs_node *pn = opc;
738 	struct sfsnode *sfs = pn->pn_data;
739 	long long ll;
740 	int i, rv;
741 	bool b;
742 
743 	/*
744 	 * I picked the wrong day to ... um, the wrong place to return errors
745 	 */
746 
747 	/* easy to support, but just unavailable now */
748 	if (rflag)
749 		return EOPNOTSUPP;
750 
751 	if (puffs_cred_isjuggernaut(cred) == 0)
752 		return EACCES;
753 
754 	if (ISADIR(sfs))
755 		return EISDIR;
756 
757 	if (offset != 0)
758 		return EINVAL;
759 
760 	if (ioflag & PUFFS_IO_APPEND)
761 		return EINVAL;
762 
763 	switch (SYSCTL_TYPE(sfs->sysctl_flags)) {
764 	case CTLTYPE_BOOL:
765 		if (strcasestr((const char *)buf, "true"))
766 			b = true;
767 		else if (strcasestr((const char *)buf, "false"))
768 			b = false;
769 		else
770 			return EINVAL;
771 		rv = sysctl(PNPATH(pn), PNPLEN(pn), NULL, NULL,
772 		    &b, sizeof(b));
773 		break;
774 	case CTLTYPE_INT:
775 		if (sscanf((const char *)buf, "%d", &i) != 1)
776 			return EINVAL;
777 		rv = sysctl(PNPATH(pn), PNPLEN(pn), NULL, NULL,
778 		    &i, sizeof(int));
779 		break;
780 	case CTLTYPE_QUAD:
781 		if (sscanf((const char *)buf, "%lld", &ll) != 1)
782 			return EINVAL;
783 		rv =  sysctl(PNPATH(pn), PNPLEN(pn), NULL, NULL,
784 		    &ll, sizeof(long long));
785 		break;
786 	case CTLTYPE_STRING:
787 		rv = sysctl(PNPATH(pn), PNPLEN(pn), NULL, NULL, buf, *resid);
788 		break;
789 	default:
790 		rv = EINVAL;
791 		break;
792 	}
793 
794 	if (rv)
795 		return rv;
796 
797 	*resid = 0;
798 	return 0;
799 }
800