xref: /netbsd-src/lib/libpuffs/null.c (revision c8a35b6227034951e874c2def577388e79ede4a5) 
1 /*	$NetBSD: null.c,v 1.27 2009/01/08 02:19:48 lukem Exp $	*/
2 
3 /*
4  * Copyright (c) 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 #include <sys/cdefs.h>
29 #if !defined(lint)
30 __RCSID("$NetBSD: null.c,v 1.27 2009/01/08 02:19:48 lukem Exp $");
31 #endif /* !lint */
32 
33 /*
34  * A "nullfs" using puffs, i.e. maps one location in the hierarchy
35  * to another using standard system calls.
36  */
37 
38 #include <sys/types.h>
39 #include <sys/time.h>
40 
41 #include <assert.h>
42 #include <dirent.h>
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <puffs.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <unistd.h>
49 
50 PUFFSOP_PROTOS(puffs_null)
51 
52 /*
53  * set attributes to what is specified.  XXX: no rollback in case of failure
54  */
55 static int
56 processvattr(const char *path, const struct vattr *va, int regular)
57 {
58 	struct timeval tv[2];
59 
60 	/* XXX: -1 == PUFFS_VNOVAL, but shouldn't trust that */
61 	if (va->va_uid != (unsigned)-1 || va->va_gid != (unsigned)-1)
62 		if (lchown(path, va->va_uid, va->va_gid) == -1)
63 			return errno;
64 
65 	if (va->va_mode != (unsigned)PUFFS_VNOVAL)
66 		if (lchmod(path, va->va_mode) == -1)
67 			return errno;
68 
69 	/* sloppy */
70 	if (va->va_atime.tv_sec != (time_t)PUFFS_VNOVAL
71 	    || va->va_mtime.tv_sec != (time_t)PUFFS_VNOVAL) {
72 		TIMESPEC_TO_TIMEVAL(&tv[0], &va->va_atime);
73 		TIMESPEC_TO_TIMEVAL(&tv[1], &va->va_mtime);
74 
75 		if (lutimes(path, tv) == -1)
76 			return errno;
77 	}
78 
79 	if (regular && va->va_size != (u_quad_t)PUFFS_VNOVAL)
80 		if (truncate(path, (off_t)va->va_size) == -1)
81 			return errno;
82 
83 	return 0;
84 }
85 
86 /*
87  * Kludge to open files which aren't writable *any longer*.  This kinda
88  * works because the vfs layer does validation checks based on the file's
89  * permissions to allow writable opening before opening them.  However,
90  * the problem arises if we want to create a file, write to it (cache),
91  * adjust permissions and then flush the file.
92  */
93 static int
94 writeableopen(const char *path)
95 {
96 	struct stat sb;
97 	mode_t origmode;
98 	int sverr = 0;
99 	int fd;
100 
101 	fd = open(path, O_WRONLY);
102 	if (fd == -1) {
103 		if (errno == EACCES) {
104 			if (stat(path, &sb) == -1)
105 				return -1;
106 			origmode = sb.st_mode & ALLPERMS;
107 
108 			if (chmod(path, 0200) == -1)
109 				return -1;
110 
111 			fd = open(path, O_WRONLY);
112 			if (fd == -1)
113 				sverr = errno;
114 
115 			chmod(path, origmode);
116 			if (sverr)
117 				errno = sverr;
118 		} else
119 			return -1;
120 	}
121 
122 	return fd;
123 }
124 
125 /*ARGSUSED*/
126 static void *
127 inodecmp(struct puffs_usermount *pu, struct puffs_node *pn, void *arg)
128 {
129 	ino_t *cmpino = arg;
130 
131 	if (pn->pn_va.va_fileid == *cmpino)
132 		return pn;
133 	return NULL;
134 }
135 
136 static int
137 makenode(struct puffs_usermount *pu, struct puffs_newinfo *pni,
138 	const struct puffs_cn *pcn, const struct vattr *va, int regular)
139 {
140 	struct puffs_node *pn;
141 	struct stat sb;
142 	int rv;
143 
144 	if ((rv = processvattr(PCNPATH(pcn), va, regular)) != 0)
145 		return rv;
146 
147 	pn = puffs_pn_new(pu, NULL);
148 	if (!pn)
149 		return ENOMEM;
150 	puffs_setvattr(&pn->pn_va, va);
151 
152 	if (lstat(PCNPATH(pcn), &sb) == -1)
153 		return errno;
154 	puffs_stat2vattr(&pn->pn_va, &sb);
155 
156 	puffs_newinfo_setcookie(pni, pn);
157 	return 0;
158 }
159 
160 /* This should be called first and overriden from the file system */
161 void
162 puffs_null_setops(struct puffs_ops *pops)
163 {
164 
165 	PUFFSOP_SET(pops, puffs_null, fs, statvfs);
166 	PUFFSOP_SETFSNOP(pops, unmount);
167 	PUFFSOP_SETFSNOP(pops, sync);
168 	PUFFSOP_SET(pops, puffs_null, fs, fhtonode);
169 	PUFFSOP_SET(pops, puffs_null, fs, nodetofh);
170 
171 	PUFFSOP_SET(pops, puffs_null, node, lookup);
172 	PUFFSOP_SET(pops, puffs_null, node, create);
173 	PUFFSOP_SET(pops, puffs_null, node, mknod);
174 	PUFFSOP_SET(pops, puffs_null, node, getattr);
175 	PUFFSOP_SET(pops, puffs_null, node, setattr);
176 	PUFFSOP_SET(pops, puffs_null, node, fsync);
177 	PUFFSOP_SET(pops, puffs_null, node, remove);
178 	PUFFSOP_SET(pops, puffs_null, node, link);
179 	PUFFSOP_SET(pops, puffs_null, node, rename);
180 	PUFFSOP_SET(pops, puffs_null, node, mkdir);
181 	PUFFSOP_SET(pops, puffs_null, node, rmdir);
182 	PUFFSOP_SET(pops, puffs_null, node, symlink);
183 	PUFFSOP_SET(pops, puffs_null, node, readlink);
184 	PUFFSOP_SET(pops, puffs_null, node, readdir);
185 	PUFFSOP_SET(pops, puffs_null, node, read);
186 	PUFFSOP_SET(pops, puffs_null, node, write);
187 	PUFFSOP_SET(pops, puffs_genfs, node, reclaim);
188 }
189 
190 /*ARGSUSED*/
191 int
192 puffs_null_fs_statvfs(struct puffs_usermount *pu, struct statvfs *svfsb)
193 {
194 
195 	if (statvfs(PNPATH(puffs_getroot(pu)), svfsb) == -1)
196 		return errno;
197 
198 	return 0;
199 }
200 
201 /*
202  * XXX: this is the stupidest crap ever, but:
203  * getfh() returns the fhandle type, when we are expected to deliver
204  * the fid type.  Just adjust it a bit and stop whining.
205  *
206  * Yes, this really really needs fixing.  Yes, *REALLY*.
207  */
208 #define FHANDLE_HEADERLEN 8
209 struct kernfid {
210 	unsigned short	fid_len;		/* length of data in bytes */
211 	unsigned short	fid_reserved;		/* compat: historic align */
212 	char		fid_data[0];		/* data (variable length) */
213 };
214 
215 /*ARGSUSED*/
216 static void *
217 fhcmp(struct puffs_usermount *pu, struct puffs_node *pn, void *arg)
218 {
219 	struct kernfid *kf1, *kf2;
220 
221 	if ((kf1 = pn->pn_data) == NULL)
222 		return NULL;
223 	kf2 = arg;
224 
225 	if (kf1->fid_len != kf2->fid_len)
226 		return NULL;
227 
228 	/*LINTED*/
229 	if (memcmp(kf1, kf2, kf1->fid_len) == 0)
230 		return pn;
231 	return NULL;
232 }
233 
234 /*
235  * This routine only supports file handles which have been issued while
236  * the server was alive.  Not really stable ones, that is.
237  */
238 /*ARGSUSED*/
239 int
240 puffs_null_fs_fhtonode(struct puffs_usermount *pu, void *fid, size_t fidsize,
241 	struct puffs_newinfo *pni)
242 {
243 	struct puffs_node *pn_res;
244 
245 	pn_res = puffs_pn_nodewalk(pu, fhcmp, fid);
246 	if (pn_res == NULL)
247 		return ENOENT;
248 
249 	puffs_newinfo_setcookie(pni, pn_res);
250 	puffs_newinfo_setvtype(pni, pn_res->pn_va.va_type);
251 	puffs_newinfo_setsize(pni, (voff_t)pn_res->pn_va.va_size);
252 	puffs_newinfo_setrdev(pni, pn_res->pn_va.va_rdev);
253 	return 0;
254 }
255 
256 /*ARGSUSED*/
257 int
258 puffs_null_fs_nodetofh(struct puffs_usermount *pu, puffs_cookie_t opc,
259 	void *fid, size_t *fidsize)
260 {
261 	struct puffs_node *pn = opc;
262 	struct kernfid *kfid;
263 	void *bounce;
264 	int rv;
265 
266 	rv = 0;
267 	bounce = NULL;
268 	if (*fidsize) {
269 		bounce = malloc(*fidsize + FHANDLE_HEADERLEN);
270 		if (!bounce)
271 			return ENOMEM;
272 		*fidsize += FHANDLE_HEADERLEN;
273 	}
274 	if (getfh(PNPATH(pn), bounce, fidsize) == -1)
275 		rv = errno;
276 	else
277 		memcpy(fid, (uint8_t *)bounce + FHANDLE_HEADERLEN,
278 		    *fidsize - FHANDLE_HEADERLEN);
279 	kfid = fid;
280 	if (rv == 0) {
281 		*fidsize = kfid->fid_len;
282 		pn->pn_data = malloc(*fidsize);
283 		if (pn->pn_data == NULL)
284 			abort(); /* lazy */
285 		memcpy(pn->pn_data, fid, *fidsize);
286 	} else {
287 		*fidsize -= FHANDLE_HEADERLEN;
288 	}
289 	free(bounce);
290 
291 	return rv;
292 }
293 
294 int
295 puffs_null_node_lookup(struct puffs_usermount *pu, puffs_cookie_t opc,
296 	struct puffs_newinfo *pni, const struct puffs_cn *pcn)
297 {
298 	struct puffs_node *pn = opc, *pn_res;
299 	struct stat sb;
300 	int rv;
301 
302 	assert(pn->pn_va.va_type == VDIR);
303 
304 	/*
305 	 * Note to whoever is copypasting this: you must first check
306 	 * if the node is there and only then do nodewalk.  Alternatively
307 	 * you could make sure that you don't return unlinked/rmdir'd
308 	 * nodes in some other fashion
309 	 */
310 	rv = lstat(PCNPATH(pcn), &sb);
311 	if (rv)
312 		return errno;
313 
314 	/* XXX2: nodewalk is a bit too slow here */
315 	pn_res = puffs_pn_nodewalk(pu, inodecmp, &sb.st_ino);
316 
317 	if (pn_res == NULL) {
318 		pn_res = puffs_pn_new(pu, NULL);
319 		if (pn_res == NULL)
320 			return ENOMEM;
321 		puffs_stat2vattr(&pn_res->pn_va, &sb);
322 	}
323 
324 	puffs_newinfo_setcookie(pni, pn_res);
325 	puffs_newinfo_setvtype(pni, pn_res->pn_va.va_type);
326 	puffs_newinfo_setsize(pni, (voff_t)pn_res->pn_va.va_size);
327 	puffs_newinfo_setrdev(pni, pn_res->pn_va.va_rdev);
328 
329 	return 0;
330 }
331 
332 /*ARGSUSED*/
333 int
334 puffs_null_node_create(struct puffs_usermount *pu, puffs_cookie_t opc,
335 	struct puffs_newinfo *pni, const struct puffs_cn *pcn,
336 	const struct vattr *va)
337 {
338 	int fd, rv;
339 
340 	fd = open(PCNPATH(pcn), O_RDWR | O_CREAT | O_TRUNC);
341 	if (fd == -1)
342 		return errno;
343 	close(fd);
344 
345 	rv = makenode(pu, pni, pcn, va, 1);
346 	if (rv)
347 		unlink(PCNPATH(pcn));
348 	return rv;
349 }
350 
351 /*ARGSUSED*/
352 int
353 puffs_null_node_mknod(struct puffs_usermount *pu, puffs_cookie_t opc,
354 	struct puffs_newinfo *pni, const struct puffs_cn *pcn,
355 	const struct vattr *va)
356 {
357 	mode_t mode;
358 	int rv;
359 
360 	mode = puffs_addvtype2mode(va->va_mode, va->va_type);
361 	if (mknod(PCNPATH(pcn), mode, va->va_rdev) == -1)
362 		return errno;
363 
364 	rv = makenode(pu, pni, pcn, va, 0);
365 	if (rv)
366 		unlink(PCNPATH(pcn));
367 	return rv;
368 }
369 
370 /*ARGSUSED*/
371 int
372 puffs_null_node_getattr(struct puffs_usermount *pu, puffs_cookie_t opc,
373 	struct vattr *va, const struct puffs_cred *pcred)
374 {
375 	struct puffs_node *pn = opc;
376 	struct stat sb;
377 
378 	if (lstat(PNPATH(pn), &sb) == -1)
379 		return errno;
380 	puffs_stat2vattr(va, &sb);
381 
382 	return 0;
383 }
384 
385 /*ARGSUSED*/
386 int
387 puffs_null_node_setattr(struct puffs_usermount *pu, puffs_cookie_t opc,
388 	const struct vattr *va, const struct puffs_cred *pcred)
389 {
390 	struct puffs_node *pn = opc;
391 	int rv;
392 
393 	rv = processvattr(PNPATH(pn), va, pn->pn_va.va_type == VREG);
394 	if (rv)
395 		return rv;
396 
397 	puffs_setvattr(&pn->pn_va, va);
398 
399 	return 0;
400 }
401 
402 /*ARGSUSED*/
403 int
404 puffs_null_node_fsync(struct puffs_usermount *pu, puffs_cookie_t opc,
405 	const struct puffs_cred *pcred, int how,
406 	off_t offlo, off_t offhi)
407 {
408 	struct puffs_node *pn = opc;
409 	int fd, rv;
410 	int fflags;
411 
412 	rv = 0;
413 	fd = writeableopen(PNPATH(pn));
414 	if (fd == -1)
415 		return errno;
416 
417 	if (how & PUFFS_FSYNC_DATAONLY)
418 		fflags = FDATASYNC;
419 	else
420 		fflags = FFILESYNC;
421 	if (how & PUFFS_FSYNC_CACHE)
422 		fflags |= FDISKSYNC;
423 
424 	if (fsync_range(fd, fflags, offlo, offhi - offlo) == -1)
425 		rv = errno;
426 
427 	close(fd);
428 
429 	return rv;
430 }
431 
432 /*ARGSUSED*/
433 int
434 puffs_null_node_remove(struct puffs_usermount *pu, puffs_cookie_t opc,
435 	puffs_cookie_t targ, const struct puffs_cn *pcn)
436 {
437 	struct puffs_node *pn_targ = targ;
438 
439 	if (unlink(PNPATH(pn_targ)) == -1)
440 		return errno;
441 	puffs_pn_remove(pn_targ);
442 
443 	return 0;
444 }
445 
446 /*ARGSUSED*/
447 int
448 puffs_null_node_link(struct puffs_usermount *pu, puffs_cookie_t opc,
449 	puffs_cookie_t targ, const struct puffs_cn *pcn)
450 {
451 	struct puffs_node *pn_targ = targ;
452 
453 	if (link(PNPATH(pn_targ), PCNPATH(pcn)) == -1)
454 		return errno;
455 
456 	return 0;
457 }
458 
459 /*ARGSUSED*/
460 int
461 puffs_null_node_rename(struct puffs_usermount *pu, puffs_cookie_t opc,
462 	puffs_cookie_t src, const struct puffs_cn *pcn_src,
463 	puffs_cookie_t targ_dir, puffs_cookie_t targ,
464 	const struct puffs_cn *pcn_targ)
465 {
466 
467 	if (rename(PCNPATH(pcn_src), PCNPATH(pcn_targ)) == -1)
468 		return errno;
469 
470 	return 0;
471 }
472 
473 /*ARGSUSED*/
474 int
475 puffs_null_node_mkdir(struct puffs_usermount *pu, puffs_cookie_t opc,
476 	struct puffs_newinfo *pni, const struct puffs_cn *pcn,
477 	const struct vattr *va)
478 {
479 	int rv;
480 
481 	if (mkdir(PCNPATH(pcn), va->va_mode) == -1)
482 		return errno;
483 
484 	rv = makenode(pu, pni, pcn, va, 0);
485 	if (rv)
486 		rmdir(PCNPATH(pcn));
487 	return rv;
488 }
489 
490 /*ARGSUSED*/
491 int
492 puffs_null_node_rmdir(struct puffs_usermount *pu, puffs_cookie_t opc,
493 	puffs_cookie_t targ, const struct puffs_cn *pcn)
494 {
495 	struct puffs_node *pn_targ = targ;
496 
497 	if (rmdir(PNPATH(pn_targ)) == -1)
498 		return errno;
499 	puffs_pn_remove(pn_targ);
500 
501 	return 0;
502 }
503 
504 /*ARGSUSED*/
505 int
506 puffs_null_node_symlink(struct puffs_usermount *pu, puffs_cookie_t opc,
507 	struct puffs_newinfo *pni, const struct puffs_cn *pcn,
508 	const struct vattr *va, const char *linkname)
509 {
510 	int rv;
511 
512 	if (symlink(linkname, PCNPATH(pcn)) == -1)
513 		return errno;
514 
515 	rv = makenode(pu, pni, pcn, va, 0);
516 	if (rv)
517 		unlink(PCNPATH(pcn));
518 	return rv;
519 }
520 
521 /*ARGSUSED*/
522 int
523 puffs_null_node_readlink(struct puffs_usermount *pu, puffs_cookie_t opc,
524 	const struct puffs_cred *pcred, char *linkname, size_t *linklen)
525 {
526 	struct puffs_node *pn = opc;
527 	ssize_t rv;
528 
529 	rv = readlink(PNPATH(pn), linkname, *linklen);
530 	if (rv == -1)
531 		return errno;
532 
533 	*linklen = rv;
534 	return 0;
535 }
536 
537 /*ARGSUSED*/
538 int
539 puffs_null_node_readdir(struct puffs_usermount *pu, puffs_cookie_t opc,
540 	struct dirent *de, off_t *off, size_t *reslen,
541 	const struct puffs_cred *pcred, int *eofflag, off_t *cookies,
542 	size_t *ncookies)
543 {
544 	struct puffs_node *pn = opc;
545 	struct dirent entry, *result;
546 	DIR *dp;
547 	off_t i;
548 	int rv;
549 
550 	*ncookies = 0;
551 	dp = opendir(PNPATH(pn));
552 	if (dp == NULL)
553 		return errno;
554 
555 	rv = 0;
556 	i = *off;
557 
558 	/*
559 	 * XXX: need to do trickery here, telldir/seekdir would be nice, but
560 	 * then we'd need to keep state, which I'm too lazy to keep
561 	 */
562 	while (i--) {
563 		rv = readdir_r(dp, &entry, &result);
564 		if (rv || !result)
565 			goto out;
566 	}
567 
568 	for (;;) {
569 		rv = readdir_r(dp, &entry, &result);
570 		if (rv != 0)
571 			goto out;
572 
573 		if (!result) {
574 			*eofflag = 1;
575 			goto out;
576 		}
577 
578 		if (_DIRENT_SIZE(result) > *reslen)
579 			goto out;
580 
581 		*de = *result;
582 		*reslen -= _DIRENT_SIZE(result);
583 		de = _DIRENT_NEXT(de);
584 
585 		(*off)++;
586 		PUFFS_STORE_DCOOKIE(cookies, ncookies, *off);
587 	}
588 
589  out:
590 	closedir(dp);
591 	return 0;
592 }
593 
594 /*ARGSUSED*/
595 int
596 puffs_null_node_read(struct puffs_usermount *pu, puffs_cookie_t opc,
597 	uint8_t *buf, off_t offset, size_t *buflen,
598 	const struct puffs_cred *pcred, int ioflag)
599 {
600 	struct puffs_node *pn = opc;
601 	ssize_t n;
602 	off_t off;
603 	int fd, rv;
604 
605 	rv = 0;
606 	fd = open(PNPATH(pn), O_RDONLY);
607 	if (fd == -1)
608 		return errno;
609 	off = lseek(fd, offset, SEEK_SET);
610 	if (off == -1) {
611 		rv = errno;
612 		goto out;
613 	}
614 
615 	n = read(fd, buf, *buflen);
616 	if (n == -1)
617 		rv = errno;
618 	else
619 		*buflen -= n;
620 
621  out:
622 	close(fd);
623 	return rv;
624 }
625 
626 /*ARGSUSED*/
627 int
628 puffs_null_node_write(struct puffs_usermount *pu, puffs_cookie_t opc,
629 	uint8_t *buf, off_t offset, size_t *buflen,
630 	const struct puffs_cred *pcred, int ioflag)
631 {
632 	struct puffs_node *pn = opc;
633 	ssize_t n;
634 	off_t off;
635 	int fd, rv;
636 
637 	rv = 0;
638 	fd = writeableopen(PNPATH(pn));
639 	if (fd == -1)
640 		return errno;
641 
642 	off = lseek(fd, offset, SEEK_SET);
643 	if (off == -1) {
644 		rv = errno;
645 		goto out;
646 	}
647 
648 	n = write(fd, buf, *buflen);
649 	if (n == -1)
650 		rv = errno;
651 	else
652 		*buflen -= n;
653 
654  out:
655 	close(fd);
656 	return rv;
657 }
658