xref: /netbsd-src/lib/libpuffs/null.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0) 
1 /*	$NetBSD: null.c,v 1.28 2009/10/18 20:14:06 pooka 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 1.28 2009/10/18 20:14:06 pooka 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/stat.h>
40 #include <sys/time.h>
41 
42 #include <assert.h>
43 #include <dirent.h>
44 #include <errno.h>
45 #include <fcntl.h>
46 #include <puffs.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <time.h>
50 #include <unistd.h>
51 
52 PUFFSOP_PROTOS(puffs_null)
53 
54 /*
55  * set attributes to what is specified.  XXX: no rollback in case of failure
56  */
57 static int
58 processvattr(const char *path, const struct vattr *va, int regular)
59 {
60 	struct timeval tv[2];
61 
62 	/* XXX: -1 == PUFFS_VNOVAL, but shouldn't trust that */
63 	if (va->va_uid != (unsigned)-1 || va->va_gid != (unsigned)-1)
64 		if (lchown(path, va->va_uid, va->va_gid) == -1)
65 			return errno;
66 
67 	if (va->va_mode != (unsigned)PUFFS_VNOVAL)
68 		if (lchmod(path, va->va_mode) == -1)
69 			return errno;
70 
71 	/* sloppy */
72 	if (va->va_atime.tv_sec != (time_t)PUFFS_VNOVAL
73 	    || va->va_mtime.tv_sec != (time_t)PUFFS_VNOVAL) {
74 		TIMESPEC_TO_TIMEVAL(&tv[0], &va->va_atime);
75 		TIMESPEC_TO_TIMEVAL(&tv[1], &va->va_mtime);
76 
77 		if (lutimes(path, tv) == -1)
78 			return errno;
79 	}
80 
81 	if (regular && va->va_size != (u_quad_t)PUFFS_VNOVAL)
82 		if (truncate(path, (off_t)va->va_size) == -1)
83 			return errno;
84 
85 	return 0;
86 }
87 
88 /*
89  * Kludge to open files which aren't writable *any longer*.  This kinda
90  * works because the vfs layer does validation checks based on the file's
91  * permissions to allow writable opening before opening them.  However,
92  * the problem arises if we want to create a file, write to it (cache),
93  * adjust permissions and then flush the file.
94  */
95 static int
96 writeableopen(const char *path)
97 {
98 	struct stat sb;
99 	mode_t origmode;
100 	int sverr = 0;
101 	int fd;
102 
103 	fd = open(path, O_WRONLY);
104 	if (fd == -1) {
105 		if (errno == EACCES) {
106 			if (stat(path, &sb) == -1)
107 				return -1;
108 			origmode = sb.st_mode & ALLPERMS;
109 
110 			if (chmod(path, 0200) == -1)
111 				return -1;
112 
113 			fd = open(path, O_WRONLY);
114 			if (fd == -1)
115 				sverr = errno;
116 
117 			chmod(path, origmode);
118 			if (sverr)
119 				errno = sverr;
120 		} else
121 			return -1;
122 	}
123 
124 	return fd;
125 }
126 
127 /*ARGSUSED*/
128 static void *
129 inodecmp(struct puffs_usermount *pu, struct puffs_node *pn, void *arg)
130 {
131 	ino_t *cmpino = arg;
132 
133 	if (pn->pn_va.va_fileid == *cmpino)
134 		return pn;
135 	return NULL;
136 }
137 
138 static int
139 makenode(struct puffs_usermount *pu, struct puffs_newinfo *pni,
140 	const struct puffs_cn *pcn, const struct vattr *va, int regular)
141 {
142 	struct puffs_node *pn;
143 	struct stat sb;
144 	int rv;
145 
146 	if ((rv = processvattr(PCNPATH(pcn), va, regular)) != 0)
147 		return rv;
148 
149 	pn = puffs_pn_new(pu, NULL);
150 	if (!pn)
151 		return ENOMEM;
152 	puffs_setvattr(&pn->pn_va, va);
153 
154 	if (lstat(PCNPATH(pcn), &sb) == -1)
155 		return errno;
156 	puffs_stat2vattr(&pn->pn_va, &sb);
157 
158 	puffs_newinfo_setcookie(pni, pn);
159 	return 0;
160 }
161 
162 /* This should be called first and overriden from the file system */
163 void
164 puffs_null_setops(struct puffs_ops *pops)
165 {
166 
167 	PUFFSOP_SET(pops, puffs_null, fs, statvfs);
168 	PUFFSOP_SETFSNOP(pops, unmount);
169 	PUFFSOP_SETFSNOP(pops, sync);
170 	PUFFSOP_SET(pops, puffs_null, fs, fhtonode);
171 	PUFFSOP_SET(pops, puffs_null, fs, nodetofh);
172 
173 	PUFFSOP_SET(pops, puffs_null, node, lookup);
174 	PUFFSOP_SET(pops, puffs_null, node, create);
175 	PUFFSOP_SET(pops, puffs_null, node, mknod);
176 	PUFFSOP_SET(pops, puffs_null, node, getattr);
177 	PUFFSOP_SET(pops, puffs_null, node, setattr);
178 	PUFFSOP_SET(pops, puffs_null, node, fsync);
179 	PUFFSOP_SET(pops, puffs_null, node, remove);
180 	PUFFSOP_SET(pops, puffs_null, node, link);
181 	PUFFSOP_SET(pops, puffs_null, node, rename);
182 	PUFFSOP_SET(pops, puffs_null, node, mkdir);
183 	PUFFSOP_SET(pops, puffs_null, node, rmdir);
184 	PUFFSOP_SET(pops, puffs_null, node, symlink);
185 	PUFFSOP_SET(pops, puffs_null, node, readlink);
186 	PUFFSOP_SET(pops, puffs_null, node, readdir);
187 	PUFFSOP_SET(pops, puffs_null, node, read);
188 	PUFFSOP_SET(pops, puffs_null, node, write);
189 	PUFFSOP_SET(pops, puffs_genfs, node, reclaim);
190 }
191 
192 /*ARGSUSED*/
193 int
194 puffs_null_fs_statvfs(struct puffs_usermount *pu, struct statvfs *svfsb)
195 {
196 
197 	if (statvfs(PNPATH(puffs_getroot(pu)), svfsb) == -1)
198 		return errno;
199 
200 	return 0;
201 }
202 
203 /*
204  * XXX: this is the stupidest crap ever, but:
205  * getfh() returns the fhandle type, when we are expected to deliver
206  * the fid type.  Just adjust it a bit and stop whining.
207  *
208  * Yes, this really really needs fixing.  Yes, *REALLY*.
209  */
210 #define FHANDLE_HEADERLEN 8
211 struct kernfid {
212 	unsigned short	fid_len;		/* length of data in bytes */
213 	unsigned short	fid_reserved;		/* compat: historic align */
214 	char		fid_data[0];		/* data (variable length) */
215 };
216 
217 /*ARGSUSED*/
218 static void *
219 fhcmp(struct puffs_usermount *pu, struct puffs_node *pn, void *arg)
220 {
221 	struct kernfid *kf1, *kf2;
222 
223 	if ((kf1 = pn->pn_data) == NULL)
224 		return NULL;
225 	kf2 = arg;
226 
227 	if (kf1->fid_len != kf2->fid_len)
228 		return NULL;
229 
230 	/*LINTED*/
231 	if (memcmp(kf1, kf2, kf1->fid_len) == 0)
232 		return pn;
233 	return NULL;
234 }
235 
236 /*
237  * This routine only supports file handles which have been issued while
238  * the server was alive.  Not really stable ones, that is.
239  */
240 /*ARGSUSED*/
241 int
242 puffs_null_fs_fhtonode(struct puffs_usermount *pu, void *fid, size_t fidsize,
243 	struct puffs_newinfo *pni)
244 {
245 	struct puffs_node *pn_res;
246 
247 	pn_res = puffs_pn_nodewalk(pu, fhcmp, fid);
248 	if (pn_res == NULL)
249 		return ENOENT;
250 
251 	puffs_newinfo_setcookie(pni, pn_res);
252 	puffs_newinfo_setvtype(pni, pn_res->pn_va.va_type);
253 	puffs_newinfo_setsize(pni, (voff_t)pn_res->pn_va.va_size);
254 	puffs_newinfo_setrdev(pni, pn_res->pn_va.va_rdev);
255 	return 0;
256 }
257 
258 /*ARGSUSED*/
259 int
260 puffs_null_fs_nodetofh(struct puffs_usermount *pu, puffs_cookie_t opc,
261 	void *fid, size_t *fidsize)
262 {
263 	struct puffs_node *pn = opc;
264 	struct kernfid *kfid;
265 	void *bounce;
266 	int rv;
267 
268 	rv = 0;
269 	bounce = NULL;
270 	if (*fidsize) {
271 		bounce = malloc(*fidsize + FHANDLE_HEADERLEN);
272 		if (!bounce)
273 			return ENOMEM;
274 		*fidsize += FHANDLE_HEADERLEN;
275 	}
276 	if (getfh(PNPATH(pn), bounce, fidsize) == -1)
277 		rv = errno;
278 	else
279 		memcpy(fid, (uint8_t *)bounce + FHANDLE_HEADERLEN,
280 		    *fidsize - FHANDLE_HEADERLEN);
281 	kfid = fid;
282 	if (rv == 0) {
283 		*fidsize = kfid->fid_len;
284 		pn->pn_data = malloc(*fidsize);
285 		if (pn->pn_data == NULL)
286 			abort(); /* lazy */
287 		memcpy(pn->pn_data, fid, *fidsize);
288 	} else {
289 		*fidsize -= FHANDLE_HEADERLEN;
290 	}
291 	free(bounce);
292 
293 	return rv;
294 }
295 
296 int
297 puffs_null_node_lookup(struct puffs_usermount *pu, puffs_cookie_t opc,
298 	struct puffs_newinfo *pni, const struct puffs_cn *pcn)
299 {
300 	struct puffs_node *pn = opc, *pn_res;
301 	struct stat sb;
302 	int rv;
303 
304 	assert(pn->pn_va.va_type == VDIR);
305 
306 	/*
307 	 * Note to whoever is copypasting this: you must first check
308 	 * if the node is there and only then do nodewalk.  Alternatively
309 	 * you could make sure that you don't return unlinked/rmdir'd
310 	 * nodes in some other fashion
311 	 */
312 	rv = lstat(PCNPATH(pcn), &sb);
313 	if (rv)
314 		return errno;
315 
316 	/* XXX2: nodewalk is a bit too slow here */
317 	pn_res = puffs_pn_nodewalk(pu, inodecmp, &sb.st_ino);
318 
319 	if (pn_res == NULL) {
320 		pn_res = puffs_pn_new(pu, NULL);
321 		if (pn_res == NULL)
322 			return ENOMEM;
323 		puffs_stat2vattr(&pn_res->pn_va, &sb);
324 	}
325 
326 	puffs_newinfo_setcookie(pni, pn_res);
327 	puffs_newinfo_setvtype(pni, pn_res->pn_va.va_type);
328 	puffs_newinfo_setsize(pni, (voff_t)pn_res->pn_va.va_size);
329 	puffs_newinfo_setrdev(pni, pn_res->pn_va.va_rdev);
330 
331 	return 0;
332 }
333 
334 /*ARGSUSED*/
335 int
336 puffs_null_node_create(struct puffs_usermount *pu, puffs_cookie_t opc,
337 	struct puffs_newinfo *pni, const struct puffs_cn *pcn,
338 	const struct vattr *va)
339 {
340 	int fd, rv;
341 
342 	fd = open(PCNPATH(pcn), O_RDWR | O_CREAT | O_TRUNC);
343 	if (fd == -1)
344 		return errno;
345 	close(fd);
346 
347 	rv = makenode(pu, pni, pcn, va, 1);
348 	if (rv)
349 		unlink(PCNPATH(pcn));
350 	return rv;
351 }
352 
353 /*ARGSUSED*/
354 int
355 puffs_null_node_mknod(struct puffs_usermount *pu, puffs_cookie_t opc,
356 	struct puffs_newinfo *pni, const struct puffs_cn *pcn,
357 	const struct vattr *va)
358 {
359 	mode_t mode;
360 	int rv;
361 
362 	mode = puffs_addvtype2mode(va->va_mode, va->va_type);
363 	if (mknod(PCNPATH(pcn), mode, va->va_rdev) == -1)
364 		return errno;
365 
366 	rv = makenode(pu, pni, pcn, va, 0);
367 	if (rv)
368 		unlink(PCNPATH(pcn));
369 	return rv;
370 }
371 
372 /*ARGSUSED*/
373 int
374 puffs_null_node_getattr(struct puffs_usermount *pu, puffs_cookie_t opc,
375 	struct vattr *va, const struct puffs_cred *pcred)
376 {
377 	struct puffs_node *pn = opc;
378 	struct stat sb;
379 
380 	if (lstat(PNPATH(pn), &sb) == -1)
381 		return errno;
382 	puffs_stat2vattr(va, &sb);
383 
384 	return 0;
385 }
386 
387 /*ARGSUSED*/
388 int
389 puffs_null_node_setattr(struct puffs_usermount *pu, puffs_cookie_t opc,
390 	const struct vattr *va, const struct puffs_cred *pcred)
391 {
392 	struct puffs_node *pn = opc;
393 	int rv;
394 
395 	rv = processvattr(PNPATH(pn), va, pn->pn_va.va_type == VREG);
396 	if (rv)
397 		return rv;
398 
399 	puffs_setvattr(&pn->pn_va, va);
400 
401 	return 0;
402 }
403 
404 /*ARGSUSED*/
405 int
406 puffs_null_node_fsync(struct puffs_usermount *pu, puffs_cookie_t opc,
407 	const struct puffs_cred *pcred, int how,
408 	off_t offlo, off_t offhi)
409 {
410 	struct puffs_node *pn = opc;
411 	int fd, rv;
412 	int fflags;
413 
414 	rv = 0;
415 	fd = writeableopen(PNPATH(pn));
416 	if (fd == -1)
417 		return errno;
418 
419 	if (how & PUFFS_FSYNC_DATAONLY)
420 		fflags = FDATASYNC;
421 	else
422 		fflags = FFILESYNC;
423 	if (how & PUFFS_FSYNC_CACHE)
424 		fflags |= FDISKSYNC;
425 
426 	if (fsync_range(fd, fflags, offlo, offhi - offlo) == -1)
427 		rv = errno;
428 
429 	close(fd);
430 
431 	return rv;
432 }
433 
434 /*ARGSUSED*/
435 int
436 puffs_null_node_remove(struct puffs_usermount *pu, puffs_cookie_t opc,
437 	puffs_cookie_t targ, const struct puffs_cn *pcn)
438 {
439 	struct puffs_node *pn_targ = targ;
440 
441 	if (unlink(PNPATH(pn_targ)) == -1)
442 		return errno;
443 	puffs_pn_remove(pn_targ);
444 
445 	return 0;
446 }
447 
448 /*ARGSUSED*/
449 int
450 puffs_null_node_link(struct puffs_usermount *pu, puffs_cookie_t opc,
451 	puffs_cookie_t targ, const struct puffs_cn *pcn)
452 {
453 	struct puffs_node *pn_targ = targ;
454 
455 	if (link(PNPATH(pn_targ), PCNPATH(pcn)) == -1)
456 		return errno;
457 
458 	return 0;
459 }
460 
461 /*ARGSUSED*/
462 int
463 puffs_null_node_rename(struct puffs_usermount *pu, puffs_cookie_t opc,
464 	puffs_cookie_t src, const struct puffs_cn *pcn_src,
465 	puffs_cookie_t targ_dir, puffs_cookie_t targ,
466 	const struct puffs_cn *pcn_targ)
467 {
468 
469 	if (rename(PCNPATH(pcn_src), PCNPATH(pcn_targ)) == -1)
470 		return errno;
471 
472 	return 0;
473 }
474 
475 /*ARGSUSED*/
476 int
477 puffs_null_node_mkdir(struct puffs_usermount *pu, puffs_cookie_t opc,
478 	struct puffs_newinfo *pni, const struct puffs_cn *pcn,
479 	const struct vattr *va)
480 {
481 	int rv;
482 
483 	if (mkdir(PCNPATH(pcn), va->va_mode) == -1)
484 		return errno;
485 
486 	rv = makenode(pu, pni, pcn, va, 0);
487 	if (rv)
488 		rmdir(PCNPATH(pcn));
489 	return rv;
490 }
491 
492 /*ARGSUSED*/
493 int
494 puffs_null_node_rmdir(struct puffs_usermount *pu, puffs_cookie_t opc,
495 	puffs_cookie_t targ, const struct puffs_cn *pcn)
496 {
497 	struct puffs_node *pn_targ = targ;
498 
499 	if (rmdir(PNPATH(pn_targ)) == -1)
500 		return errno;
501 	puffs_pn_remove(pn_targ);
502 
503 	return 0;
504 }
505 
506 /*ARGSUSED*/
507 int
508 puffs_null_node_symlink(struct puffs_usermount *pu, puffs_cookie_t opc,
509 	struct puffs_newinfo *pni, const struct puffs_cn *pcn,
510 	const struct vattr *va, const char *linkname)
511 {
512 	int rv;
513 
514 	if (symlink(linkname, PCNPATH(pcn)) == -1)
515 		return errno;
516 
517 	rv = makenode(pu, pni, pcn, va, 0);
518 	if (rv)
519 		unlink(PCNPATH(pcn));
520 	return rv;
521 }
522 
523 /*ARGSUSED*/
524 int
525 puffs_null_node_readlink(struct puffs_usermount *pu, puffs_cookie_t opc,
526 	const struct puffs_cred *pcred, char *linkname, size_t *linklen)
527 {
528 	struct puffs_node *pn = opc;
529 	ssize_t rv;
530 
531 	rv = readlink(PNPATH(pn), linkname, *linklen);
532 	if (rv == -1)
533 		return errno;
534 
535 	*linklen = rv;
536 	return 0;
537 }
538 
539 /*ARGSUSED*/
540 int
541 puffs_null_node_readdir(struct puffs_usermount *pu, puffs_cookie_t opc,
542 	struct dirent *de, off_t *off, size_t *reslen,
543 	const struct puffs_cred *pcred, int *eofflag, off_t *cookies,
544 	size_t *ncookies)
545 {
546 	struct puffs_node *pn = opc;
547 	struct dirent entry, *result;
548 	DIR *dp;
549 	off_t i;
550 	int rv;
551 
552 	*ncookies = 0;
553 	dp = opendir(PNPATH(pn));
554 	if (dp == NULL)
555 		return errno;
556 
557 	rv = 0;
558 	i = *off;
559 
560 	/*
561 	 * XXX: need to do trickery here, telldir/seekdir would be nice, but
562 	 * then we'd need to keep state, which I'm too lazy to keep
563 	 */
564 	while (i--) {
565 		rv = readdir_r(dp, &entry, &result);
566 		if (rv || !result)
567 			goto out;
568 	}
569 
570 	for (;;) {
571 		rv = readdir_r(dp, &entry, &result);
572 		if (rv != 0)
573 			goto out;
574 
575 		if (!result) {
576 			*eofflag = 1;
577 			goto out;
578 		}
579 
580 		if (_DIRENT_SIZE(result) > *reslen)
581 			goto out;
582 
583 		*de = *result;
584 		*reslen -= _DIRENT_SIZE(result);
585 		de = _DIRENT_NEXT(de);
586 
587 		(*off)++;
588 		PUFFS_STORE_DCOOKIE(cookies, ncookies, *off);
589 	}
590 
591  out:
592 	closedir(dp);
593 	return 0;
594 }
595 
596 /*ARGSUSED*/
597 int
598 puffs_null_node_read(struct puffs_usermount *pu, puffs_cookie_t opc,
599 	uint8_t *buf, off_t offset, size_t *buflen,
600 	const struct puffs_cred *pcred, int ioflag)
601 {
602 	struct puffs_node *pn = opc;
603 	ssize_t n;
604 	off_t off;
605 	int fd, rv;
606 
607 	rv = 0;
608 	fd = open(PNPATH(pn), O_RDONLY);
609 	if (fd == -1)
610 		return errno;
611 	off = lseek(fd, offset, SEEK_SET);
612 	if (off == -1) {
613 		rv = errno;
614 		goto out;
615 	}
616 
617 	n = read(fd, buf, *buflen);
618 	if (n == -1)
619 		rv = errno;
620 	else
621 		*buflen -= n;
622 
623  out:
624 	close(fd);
625 	return rv;
626 }
627 
628 /*ARGSUSED*/
629 int
630 puffs_null_node_write(struct puffs_usermount *pu, puffs_cookie_t opc,
631 	uint8_t *buf, off_t offset, size_t *buflen,
632 	const struct puffs_cred *pcred, int ioflag)
633 {
634 	struct puffs_node *pn = opc;
635 	ssize_t n;
636 	off_t off;
637 	int fd, rv;
638 
639 	rv = 0;
640 	fd = writeableopen(PNPATH(pn));
641 	if (fd == -1)
642 		return errno;
643 
644 	off = lseek(fd, offset, SEEK_SET);
645 	if (off == -1) {
646 		rv = errno;
647 		goto out;
648 	}
649 
650 	n = write(fd, buf, *buflen);
651 	if (n == -1)
652 		rv = errno;
653 	else
654 		*buflen -= n;
655 
656  out:
657 	close(fd);
658 	return rv;
659 }
660