rot13fs.c revision 1.11
1 /* $NetBSD: rot13fs.c,v 1.11 2007/06/24 18:59:27 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 /* 29 * rot13fs: puffs layering experiment 30 * (unfinished, as is probably fairly easy to tell) 31 * 32 * This also demonstrates how namemod can be easily set to any 33 * function which reverses itself (argument -f provides a case-flipping 34 * file system). 35 */ 36 37 #include <ctype.h> 38 #include <err.h> 39 #include <errno.h> 40 #include <puffs.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <unistd.h> 44 45 PUFFSOP_PROTOS(rot13) 46 47 static void usage(void); 48 49 static void 50 usage() 51 { 52 53 errx(1, "usage: %s [-s][-o mntopts]rot13path mountpath", 54 getprogname()); 55 } 56 57 static void (*flipflop)(void *, size_t); 58 59 static uint8_t tbl[256]; 60 61 static void 62 dorot13(void *buf, size_t buflen) 63 { 64 uint8_t *b = buf; 65 66 while (buflen--) { 67 *b = tbl[*b]; 68 b++; 69 } 70 } 71 72 static void 73 docase(void *buf, size_t buflen) 74 { 75 unsigned char *b = buf; 76 77 while (buflen--) { 78 if (isalpha(*b)) 79 *b ^= 0x20; 80 b++; 81 } 82 } 83 84 static int 85 rot13path(struct puffs_usermount *pu, struct puffs_pathobj *base, 86 struct puffs_cn *pcn) 87 { 88 89 flipflop(pcn->pcn_name, pcn->pcn_namelen); 90 91 return 0; 92 } 93 94 int 95 main(int argc, char *argv[]) 96 { 97 struct puffs_usermount *pu; 98 struct puffs_ops *pops; 99 struct puffs_pathobj *po_root; 100 struct puffs_node *pn_root; 101 struct stat sb; 102 mntoptparse_t mp; 103 int mntflags, pflags, lflags; 104 int ch; 105 int i; 106 107 setprogname(argv[0]); 108 109 if (argc < 3) 110 usage(); 111 112 flipflop = dorot13; 113 pflags = lflags = mntflags = 0; 114 while ((ch = getopt(argc, argv, "fo:s")) != -1) { 115 switch (ch) { 116 case 'f': 117 flipflop = docase; 118 break; 119 case 'o': 120 mp = getmntopts(optarg, puffsmopts, &mntflags, &pflags); 121 if (mp == NULL) 122 err(1, "getmntopts"); 123 freemntopts(mp); 124 break; 125 case 's': 126 lflags |= PUFFSLOOP_NODAEMON; 127 break; 128 } 129 } 130 pflags |= PUFFS_FLAG_BUILDPATH; 131 argv += optind; 132 argc -= optind; 133 134 if (pflags & PUFFS_FLAG_OPDUMP) 135 lflags = PUFFSLOOP_NODAEMON; 136 137 if (argc != 2) 138 usage(); 139 140 if (lstat(argv[0], &sb) == -1) 141 err(1, "stat %s", argv[0]); 142 if ((sb.st_mode & S_IFDIR) == 0) 143 errx(1, "%s is not a directory", argv[0]); 144 145 PUFFSOP_INIT(pops); 146 puffs_null_setops(pops); 147 148 PUFFSOP_SET(pops, rot13, node, readdir); 149 PUFFSOP_SET(pops, rot13, node, read); 150 PUFFSOP_SET(pops, rot13, node, write); 151 152 if ((pu = puffs_init(pops, "rot13", NULL, pflags)) == NULL) 153 err(1, "mount"); 154 155 pn_root = puffs_pn_new(pu, NULL); 156 if (pn_root == NULL) 157 err(1, "puffs_pn_new"); 158 puffs_setroot(pu, pn_root); 159 160 po_root = puffs_getrootpathobj(pu); 161 if (po_root == NULL) 162 err(1, "getrootpathobj"); 163 po_root->po_path = argv[0]; 164 po_root->po_len = strlen(argv[0]); 165 puffs_stat2vattr(&pn_root->pn_va, &sb); 166 167 puffs_set_namemod(pu, rot13path); 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_mount(pu, argv[1], mntflags, pn_root) == -1) 178 err(1, "puffs_mount"); 179 180 return puffs_mainloop(pu, lflags); 181 } 182 183 int 184 rot13_node_readdir(struct puffs_cc *pcc, void *opc, struct dirent *dent, 185 off_t *readoff, size_t *reslen, const struct puffs_cred *pcr, 186 int *eofflag, off_t *cookies, size_t *ncookies) 187 { 188 struct dirent *dp; 189 size_t rl; 190 int rv; 191 192 dp = dent; 193 rl = *reslen; 194 195 rv = puffs_null_node_readdir(pcc, opc, dent, readoff, reslen, pcr, 196 eofflag, cookies, ncookies); 197 if (rv) 198 return rv; 199 200 while (rl > *reslen) { 201 flipflop((uint8_t *)dp->d_name, dp->d_namlen); 202 rl -= _DIRENT_SIZE(dp); 203 dp = _DIRENT_NEXT(dp); 204 } 205 206 return 0; 207 } 208 209 int 210 rot13_node_read(struct puffs_cc *pcc, void *opc, uint8_t *buf, off_t offset, 211 size_t *resid, const struct puffs_cred *pcr, int ioflag) 212 { 213 uint8_t *prebuf = buf; 214 size_t preres = *resid; 215 int rv; 216 217 rv = puffs_null_node_read(pcc, opc, buf, offset, resid, pcr, ioflag); 218 if (rv) 219 return rv; 220 221 flipflop(prebuf, preres - *resid); 222 223 return rv; 224 } 225 226 int 227 rot13_node_write(struct puffs_cc *pcc, void *opc, uint8_t *buf, off_t offset, 228 size_t *resid, const struct puffs_cred *pcr, int ioflag) 229 { 230 231 flipflop(buf, *resid); 232 return puffs_null_node_write(pcc, opc, buf, offset, resid, pcr, ioflag); 233 } 234
Indexes created Tue Sep 30 20:09:53 GMT 2025