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rot13fs.c revision 1.3
      1 /*	$NetBSD: rot13fs.c,v 1.3 2007/04/11 21:10:49 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  * 3. The name of the company nor the name of the author may be used to
     15  *    endorse or promote products derived from this software without specific
     16  *    prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
     19  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     21  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     28  * SUCH DAMAGE.
     29  */
     30 
     31 /*
     32  * rot13fs: puffs layering experiment
     33  * (unfinished, as is probably fairly easy to tell)
     34  */
     35 
     36 #include <err.h>
     37 #include <errno.h>
     38 #include <puffs.h>
     39 #include <stdio.h>
     40 #include <stdlib.h>
     41 #include <unistd.h>
     42 
     43 PUFFSOP_PROTOS(puffs_null) /* XXX */
     44 PUFFSOP_PROTOS(rot13)
     45 
     46 static void usage(void);
     47 
     48 static void
     49 usage()
     50 {
     51 
     52 	errx(1, "usage: %s [-s][-o mntopts]rot13path mountpath",
     53 	    getprogname());
     54 }
     55 
     56 static uint8_t tbl[256];
     57 
     58 static void
     59 dorot13(void *buf, size_t buflen)
     60 {
     61 	uint8_t *b = buf;
     62 
     63 	while (buflen--) {
     64 		*b = tbl[*b];
     65 		b++;
     66 	}
     67 }
     68 
     69 static int
     70 rot13path(struct puffs_usermount *pu, struct puffs_pathobj *base,
     71 	struct puffs_cn *pcn)
     72 {
     73 
     74 	dorot13(pcn->pcn_name, pcn->pcn_namelen);
     75 
     76 	return 0;
     77 }
     78 
     79 int
     80 main(int argc, char *argv[])
     81 {
     82 	struct puffs_usermount *pu;
     83 	struct puffs_ops *pops;
     84 	struct puffs_pathobj *po_root;
     85 	struct statvfs svfsb;
     86 	struct stat sb;
     87 	mntoptparse_t mp;
     88 	int mntflags, pflags, lflags;
     89 	int ch;
     90 	int i;
     91 
     92 	setprogname(argv[0]);
     93 
     94 	if (argc < 3)
     95 		usage();
     96 
     97 	pflags = lflags = mntflags = 0;
     98 	while ((ch = getopt(argc, argv, "o:s")) != -1) {
     99 		switch (ch) {
    100 		case 'o':
    101 			mp = getmntopts(optarg, puffsmopts, &mntflags, &pflags);
    102 			if (mp == NULL)
    103 				err(1, "getmntopts");
    104 			freemntopts(mp);
    105 			break;
    106 		case 's':
    107 			lflags |= PUFFSLOOP_NODAEMON;
    108 			break;
    109 		}
    110 	}
    111 	pflags |= PUFFS_FLAG_BUILDPATH;
    112 	argv += optind;
    113 	argc -= optind;
    114 
    115 	if (pflags & PUFFS_FLAG_OPDUMP)
    116 		lflags = PUFFSLOOP_NODAEMON;
    117 
    118 	if (argc != 2)
    119 		usage();
    120 
    121 	PUFFSOP_INIT(pops);
    122 
    123 	PUFFSOP_SET(pops, puffs_null, fs, statvfs);
    124 	PUFFSOP_SETFSNOP(pops, unmount);
    125 	PUFFSOP_SETFSNOP(pops, sync);
    126 
    127 	PUFFSOP_SET(pops, rot13, node, readdir);
    128 	PUFFSOP_SET(pops, rot13, node, read);
    129 	PUFFSOP_SET(pops, rot13, node, write);
    130 
    131 	PUFFSOP_SET(pops, puffs_null, node, lookup);
    132 	PUFFSOP_SET(pops, puffs_null, node, create);
    133 	PUFFSOP_SET(pops, puffs_null, node, mknod);
    134 	PUFFSOP_SET(pops, puffs_null, node, getattr);
    135 	PUFFSOP_SET(pops, puffs_null, node, setattr);
    136 	PUFFSOP_SET(pops, puffs_null, node, fsync);
    137 	PUFFSOP_SET(pops, puffs_null, node, remove);
    138 	PUFFSOP_SET(pops, puffs_null, node, link);
    139 	PUFFSOP_SET(pops, puffs_null, node, rename);
    140 	PUFFSOP_SET(pops, puffs_null, node, mkdir);
    141 	PUFFSOP_SET(pops, puffs_null, node, rmdir);
    142 	PUFFSOP_SET(pops, puffs_null, node, symlink);
    143 	PUFFSOP_SET(pops, puffs_null, node, readlink);
    144 	PUFFSOP_SET(pops, puffs_null, node, reclaim);
    145 
    146 	if ((pu = puffs_mount(pops, argv[1], mntflags, "rot13", NULL,
    147 	    pflags, 0)) == NULL)
    148 		err(1, "mount");
    149 
    150 	if (statvfs(argv[0], &svfsb) == -1)
    151 		err(1, "statvfs %s", argv[0]);
    152 
    153 	pu->pu_pn_root = puffs_pn_new(pu, NULL);
    154 	if (pu->pu_pn_root == NULL)
    155 		err(1, "puffs_pn_new");
    156 
    157 	po_root = puffs_getrootpathobj(pu);
    158 	if (po_root == NULL)
    159 		err(1, "getrootpathobj");
    160 	po_root->po_path = argv[0];
    161 	po_root->po_len = strlen(argv[0]);
    162 
    163 	puffs_set_namemod(pu, rot13path);
    164 
    165 	if (stat(argv[0], &sb) == -1)
    166 		err(1, "stat %s", argv[0]);
    167 	puffs_stat2vattr(&pu->pu_pn_root->pn_va, &sb);
    168 
    169 	/* initialize rot13 tables */
    170 	for (i = 0; i < 256; i++)
    171 		tbl[i] = (uint8_t)i;
    172 	for (i = 0; i <= 26; i++)
    173 		tbl[i + 'a'] = 'a' + ((i + 13) % 26);
    174 	for (i = 0; i < 26; i++)
    175 		tbl[i + 'A'] = 'A' + ((i + 13) % 26);
    176 
    177 	if (puffs_start(pu, pu->pu_pn_root, &svfsb) == -1)
    178 		err(1, "puffs_start");
    179 
    180 	if (puffs_mainloop(pu, lflags) == -1)
    181 		err(1, "mainloop");
    182 
    183 	return 0;
    184 }
    185 
    186 int
    187 rot13_node_readdir(struct puffs_cc *pcc, void *opc, struct dirent *dent,
    188 	off_t *readoff, size_t *reslen, const struct puffs_cred *pcr,
    189 	int *eofflag, off_t *cookies, size_t *ncookies)
    190 {
    191 	struct dirent *dp;
    192 	size_t rl;
    193 	int rv;
    194 
    195 	dp = dent;
    196 	rl = *reslen;
    197 
    198 	rv = puffs_null_node_readdir(pcc, opc, dent, readoff, reslen, pcr,
    199 	    eofflag, cookies, ncookies);
    200 	if (rv)
    201 		return rv;
    202 
    203 	while (rl > *reslen) {
    204 		dorot13((uint8_t *)dp->d_name, dp->d_namlen);
    205 		rl -= _DIRENT_SIZE(dp);
    206 		dp = _DIRENT_NEXT(dp);
    207 	}
    208 
    209 	return 0;
    210 }
    211 
    212 int
    213 rot13_node_read(struct puffs_cc *pcc, void *opc, uint8_t *buf, off_t offset,
    214 	size_t *resid, const struct puffs_cred *pcr, int ioflag)
    215 {
    216 	uint8_t *prebuf = buf;
    217 	size_t preres = *resid;
    218 	int rv;
    219 
    220 	rv = puffs_null_node_read(pcc, opc, buf, offset, resid, pcr, ioflag);
    221 	if (rv)
    222 		return rv;
    223 
    224 	dorot13(prebuf, preres - *resid);
    225 
    226 	return rv;
    227 }
    228 
    229 int
    230 rot13_node_write(struct puffs_cc *pcc, void *opc, uint8_t *buf, off_t offset,
    231 	size_t *resid, const struct puffs_cred *pcr, int ioflag)
    232 {
    233 
    234 	dorot13(buf, *resid);
    235 	return puffs_null_node_write(pcc, opc, buf, offset, resid, pcr, ioflag);
    236 }
    237