Home | History | Annotate | Line # | Download | only in libpuffs
null.c revision 1.20 
      1 /*	$NetBSD: null.c,v 1.20 2007/07/01 17:22:18 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 1.20 2007/07/01 17:22:18 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/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 != (unsigned)PUFFS_VNOVAL
     71 	    || va->va_mtime.tv_sec != (unsigned)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, void **newnode,
    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 	*newnode = 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 
    169 	PUFFSOP_SET(pops, puffs_null, node, lookup);
    170 	PUFFSOP_SET(pops, puffs_null, node, create);
    171 	PUFFSOP_SET(pops, puffs_null, node, mknod);
    172 	PUFFSOP_SET(pops, puffs_null, node, getattr);
    173 	PUFFSOP_SET(pops, puffs_null, node, setattr);
    174 	PUFFSOP_SET(pops, puffs_null, node, fsync);
    175 	PUFFSOP_SET(pops, puffs_null, node, remove);
    176 	PUFFSOP_SET(pops, puffs_null, node, link);
    177 	PUFFSOP_SET(pops, puffs_null, node, rename);
    178 	PUFFSOP_SET(pops, puffs_null, node, mkdir);
    179 	PUFFSOP_SET(pops, puffs_null, node, rmdir);
    180 	PUFFSOP_SET(pops, puffs_null, node, symlink);
    181 	PUFFSOP_SET(pops, puffs_null, node, readlink);
    182 	PUFFSOP_SET(pops, puffs_null, node, readdir);
    183 	PUFFSOP_SET(pops, puffs_null, node, read);
    184 	PUFFSOP_SET(pops, puffs_null, node, write);
    185 	PUFFSOP_SET(pops, puffs_null, node, reclaim);
    186 }
    187 
    188 /*ARGSUSED*/
    189 int
    190 puffs_null_fs_statvfs(struct puffs_cc *pcc, struct statvfs *svfsb,
    191 	const struct puffs_cid *pcid)
    192 {
    193 	struct puffs_usermount *pu = puffs_cc_getusermount(pcc);
    194 
    195 	if (statvfs(PNPATH(puffs_getroot(pu)), svfsb) == -1)
    196 		return errno;
    197 
    198 	return 0;
    199 }
    200 
    201 int
    202 puffs_null_node_lookup(struct puffs_cc *pcc, void *opc, void **newnode,
    203 	enum vtype *newtype, voff_t *newsize, dev_t *newrdev,
    204 	const struct puffs_cn *pcn)
    205 {
    206 	struct puffs_usermount *pu = puffs_cc_getusermount(pcc);
    207 	struct puffs_node *pn = opc, *pn_res;
    208 	struct stat sb;
    209 	int rv;
    210 
    211 	assert(pn->pn_va.va_type == VDIR);
    212 
    213 	/*
    214 	 * Note to whoever is copypasting this: you must first check
    215 	 * if the node is there and only then do nodewalk.  Alternatively
    216 	 * you could make sure that you don't return unlinked/rmdir'd
    217 	 * nodes in some other fashion
    218 	 */
    219 	rv = lstat(PCNPATH(pcn), &sb);
    220 	if (rv)
    221 		return errno;
    222 
    223 	/* XXX2: nodewalk is a bit too slow here */
    224 	pn_res = puffs_pn_nodewalk(pu, inodecmp, &sb.st_ino);
    225 
    226 	if (pn_res == NULL) {
    227 		pn_res = puffs_pn_new(pu, NULL);
    228 		if (pn_res == NULL)
    229 			return ENOMEM;
    230 		puffs_stat2vattr(&pn_res->pn_va, &sb);
    231 	}
    232 
    233 	*newnode = pn_res;
    234 	*newtype = pn_res->pn_va.va_type;
    235 	*newsize = pn_res->pn_va.va_size;
    236 	*newrdev = pn_res->pn_va.va_rdev;
    237 
    238 	return 0;
    239 }
    240 
    241 /*ARGSUSED*/
    242 int
    243 puffs_null_node_create(struct puffs_cc *pcc, void *opc, void **newnode,
    244 	const struct puffs_cn *pcn, const struct vattr *va)
    245 {
    246 	struct puffs_usermount *pu = puffs_cc_getusermount(pcc);
    247 	int fd, rv;
    248 
    249 	fd = open(PCNPATH(pcn), O_RDWR | O_CREAT | O_TRUNC);
    250 	if (fd == -1)
    251 		return errno;
    252 	close(fd);
    253 
    254 	rv = makenode(pu, newnode, pcn, va, 1);
    255 	if (rv)
    256 		unlink(PCNPATH(pcn));
    257 	return rv;
    258 }
    259 
    260 /*ARGSUSED*/
    261 int
    262 puffs_null_node_mknod(struct puffs_cc *pcc, void *opc, void **newnode,
    263 	const struct puffs_cn *pcn, const struct vattr *va)
    264 {
    265 	struct puffs_usermount *pu = puffs_cc_getusermount(pcc);
    266 	mode_t mode;
    267 	int rv;
    268 
    269 	mode = puffs_addvtype2mode(va->va_mode, va->va_type);
    270 	if (mknod(PCNPATH(pcn), mode, va->va_rdev) == -1)
    271 		return errno;
    272 
    273 	rv = makenode(pu, newnode, pcn, va, 0);
    274 	if (rv)
    275 		unlink(PCNPATH(pcn));
    276 	return rv;
    277 }
    278 
    279 /*ARGSUSED*/
    280 int
    281 puffs_null_node_getattr(struct puffs_cc *pcc, void *opc, struct vattr *va,
    282 	const struct puffs_cred *pcred, const struct puffs_cid *pcid)
    283 {
    284 	struct puffs_node *pn = opc;
    285 	struct stat sb;
    286 
    287 	if (lstat(PNPATH(pn), &sb) == -1)
    288 		return errno;
    289 	puffs_stat2vattr(va, &sb);
    290 
    291 	return 0;
    292 }
    293 
    294 /*ARGSUSED*/
    295 int
    296 puffs_null_node_setattr(struct puffs_cc *pcc, void *opc,
    297 	const struct vattr *va, const struct puffs_cred *pcred,
    298 	const struct puffs_cid *pcid)
    299 {
    300 	struct puffs_node *pn = opc;
    301 	int rv;
    302 
    303 	rv = processvattr(PNPATH(pn), va, pn->pn_va.va_type == VREG);
    304 	if (rv)
    305 		return rv;
    306 
    307 	puffs_setvattr(&pn->pn_va, va);
    308 
    309 	return 0;
    310 }
    311 
    312 /*ARGSUSED*/
    313 int
    314 puffs_null_node_fsync(struct puffs_cc *pcc, void *opc,
    315 	const struct puffs_cred *pcred, int how,
    316 	off_t offlo, off_t offhi, const struct puffs_cid *pcid)
    317 {
    318 	struct puffs_node *pn = opc;
    319 	int fd, rv;
    320 	int fflags;
    321 
    322 	rv = 0;
    323 	fd = writeableopen(PNPATH(pn));
    324 	if (fd == -1)
    325 		return errno;
    326 
    327 	if (how & PUFFS_FSYNC_DATAONLY)
    328 		fflags = FDATASYNC;
    329 	else
    330 		fflags = FFILESYNC;
    331 	if (how & PUFFS_FSYNC_CACHE)
    332 		fflags |= FDISKSYNC;
    333 
    334 	if (fsync_range(fd, fflags, offlo, offhi - offlo) == -1)
    335 		rv = errno;
    336 
    337 	close(fd);
    338 
    339 	return rv;
    340 }
    341 
    342 /*ARGSUSED*/
    343 int
    344 puffs_null_node_remove(struct puffs_cc *pcc, void *opc, void *targ,
    345 	const struct puffs_cn *pcn)
    346 {
    347 	struct puffs_node *pn_targ = targ;
    348 
    349 	if (unlink(PNPATH(pn_targ)) == -1)
    350 		return errno;
    351 	puffs_pn_remove(pn_targ);
    352 
    353 	return 0;
    354 }
    355 
    356 /*ARGSUSED*/
    357 int
    358 puffs_null_node_link(struct puffs_cc *pcc, void *opc, void *targ,
    359 	const struct puffs_cn *pcn)
    360 {
    361 	struct puffs_node *pn_targ = targ;
    362 
    363 	if (link(PNPATH(pn_targ), PCNPATH(pcn)) == -1)
    364 		return errno;
    365 
    366 	return 0;
    367 }
    368 
    369 /*ARGSUSED*/
    370 int
    371 puffs_null_node_rename(struct puffs_cc *pcc, void *opc, void *src,
    372 	const struct puffs_cn *pcn_src, void *targ_dir, void *targ,
    373 	const struct puffs_cn *pcn_targ)
    374 {
    375 
    376 	if (rename(PCNPATH(pcn_src), PCNPATH(pcn_targ)) == -1)
    377 		return errno;
    378 
    379 	return 0;
    380 }
    381 
    382 /*ARGSUSED*/
    383 int
    384 puffs_null_node_mkdir(struct puffs_cc *pcc, void *opc, void **newnode,
    385 	const struct puffs_cn *pcn, const struct vattr *va)
    386 {
    387 	struct puffs_usermount *pu = puffs_cc_getusermount(pcc);
    388 	int rv;
    389 
    390 	if (mkdir(PCNPATH(pcn), va->va_mode) == -1)
    391 		return errno;
    392 
    393 	rv = makenode(pu, newnode, pcn, va, 0);
    394 	if (rv)
    395 		rmdir(PCNPATH(pcn));
    396 	return rv;
    397 }
    398 
    399 /*ARGSUSED*/
    400 int
    401 puffs_null_node_rmdir(struct puffs_cc *pcc, void *opc, void *targ,
    402 	const struct puffs_cn *pcn)
    403 {
    404 	struct puffs_node *pn_targ = targ;
    405 
    406 	if (rmdir(PNPATH(pn_targ)) == -1)
    407 		return errno;
    408 	puffs_pn_remove(pn_targ);
    409 
    410 	return 0;
    411 }
    412 
    413 /*ARGSUSED*/
    414 int
    415 puffs_null_node_symlink(struct puffs_cc *pcc, void *opc, void **newnode,
    416 	const struct puffs_cn *pcn, const struct vattr *va,
    417 	const char *linkname)
    418 {
    419 	struct puffs_usermount *pu = puffs_cc_getusermount(pcc);
    420 	int rv;
    421 
    422 	if (symlink(linkname, PCNPATH(pcn)) == -1)
    423 		return errno;
    424 
    425 	rv = makenode(pu, newnode, pcn, va, 0);
    426 	if (rv)
    427 		unlink(PCNPATH(pcn));
    428 	return rv;
    429 }
    430 
    431 /*ARGSUSED*/
    432 int
    433 puffs_null_node_readlink(struct puffs_cc *pcc, void *opc,
    434 	const struct puffs_cred *pcred, char *linkname, size_t *linklen)
    435 {
    436 	struct puffs_node *pn = opc;
    437 	ssize_t rv;
    438 
    439 	rv = readlink(PNPATH(pn), linkname, *linklen);
    440 	if (rv == -1)
    441 		return errno;
    442 
    443 	*linklen = rv;
    444 	return 0;
    445 }
    446 
    447 /*ARGSUSED*/
    448 int
    449 puffs_null_node_readdir(struct puffs_cc *pcc, void *opc, struct dirent *de,
    450 	off_t *off, size_t *reslen, const struct puffs_cred *pcred,
    451 	int *eofflag, off_t *cookies, size_t *ncookies)
    452 {
    453 	struct puffs_node *pn = opc;
    454 	struct dirent entry, *result;
    455 	DIR *dp;
    456 	off_t i;
    457 	int rv;
    458 
    459 	dp = opendir(PNPATH(pn));
    460 	if (dp == NULL)
    461 		return errno;
    462 
    463 	rv = 0;
    464 	i = *off;
    465 
    466 	/*
    467 	 * XXX: need to do trickery here, telldir/seekdir would be nice, but
    468 	 * then we'd need to keep state, which I'm too lazy to keep
    469 	 */
    470 	while (i--) {
    471 		rv = readdir_r(dp, &entry, &result);
    472 		if (rv || !result)
    473 			goto out;
    474 	}
    475 
    476 	for (;;) {
    477 		rv = readdir_r(dp, &entry, &result);
    478 		if (rv != 0)
    479 			goto out;
    480 
    481 		if (!result)
    482 			goto out;
    483 
    484 		if (_DIRENT_SIZE(result) > *reslen)
    485 			goto out;
    486 
    487 		*de = *result;
    488 		*reslen -= _DIRENT_SIZE(result);
    489 		de = _DIRENT_NEXT(de);
    490 
    491 		(*off)++;
    492 	}
    493 
    494  out:
    495 	closedir(dp);
    496 	return 0;
    497 }
    498 
    499 /*ARGSUSED*/
    500 int
    501 puffs_null_node_read(struct puffs_cc *pcc, void *opc, uint8_t *buf,
    502 	off_t offset, size_t *buflen, const struct puffs_cred *pcred,
    503 	int ioflag)
    504 {
    505 	struct puffs_node *pn = opc;
    506 	ssize_t n;
    507 	off_t off;
    508 	int fd, rv;
    509 
    510 	rv = 0;
    511 	fd = open(PNPATH(pn), O_RDONLY);
    512 	if (fd == -1)
    513 		return errno;
    514 	off = lseek(fd, offset, SEEK_SET);
    515 	if (off == -1) {
    516 		rv = errno;
    517 		goto out;
    518 	}
    519 
    520 	n = read(fd, buf, *buflen);
    521 	if (n == -1)
    522 		rv = errno;
    523 	else
    524 		*buflen -= n;
    525 
    526  out:
    527 	close(fd);
    528 	return rv;
    529 }
    530 
    531 /*ARGSUSED*/
    532 int
    533 puffs_null_node_write(struct puffs_cc *pcc, void *opc, uint8_t *buf,
    534 	off_t offset, size_t *buflen, const struct puffs_cred *pcred,
    535 	int ioflag)
    536 {
    537 	struct puffs_node *pn = opc;
    538 	ssize_t n;
    539 	off_t off;
    540 	int fd, rv;
    541 
    542 	rv = 0;
    543 	fd = writeableopen(PNPATH(pn));
    544 	if (fd == -1)
    545 		return errno;
    546 
    547 	off = lseek(fd, offset, SEEK_SET);
    548 	if (off == -1) {
    549 		rv = errno;
    550 		goto out;
    551 	}
    552 
    553 	n = write(fd, buf, *buflen);
    554 	if (n == -1)
    555 		rv = errno;
    556 	else
    557 		*buflen -= n;
    558 
    559  out:
    560 	close(fd);
    561 	return rv;
    562 }
    563 
    564 /*ARGSUSED*/
    565 int
    566 puffs_null_node_reclaim(struct puffs_cc *pcc, void *opc,
    567 	const struct puffs_cid *pcid)
    568 {
    569 
    570 	return puffs_genfs_node_reclaim(pcc, opc, pcid);
    571 }
    572