1 /* $NetBSD: rot13fs.c,v 1.17 2008/09/12 14:40:47 christos 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; 104 int detach; 105 int ch; 106 int i; 107 108 setprogname(argv[0]); 109 110 if (argc < 3) 111 usage(); 112 113 flipflop = dorot13; 114 pflags = mntflags = 0; 115 detach = 1; 116 while ((ch = getopt(argc, argv, "fo:s")) != -1) { 117 switch (ch) { 118 case 'f': 119 flipflop = docase; 120 break; 121 case 'o': 122 mp = getmntopts(optarg, puffsmopts, &mntflags, &pflags); 123 if (mp == NULL) 124 err(1, "getmntopts"); 125 freemntopts(mp); 126 break; 127 case 's': 128 detach = 0; 129 break; 130 } 131 } 132 pflags |= PUFFS_FLAG_BUILDPATH; 133 argv += optind; 134 argc -= optind; 135 136 if (pflags & PUFFS_FLAG_OPDUMP) 137 detach = 0; 138 139 if (argc != 2) 140 usage(); 141 142 if (lstat(argv[0], &sb) == -1) 143 err(1, "stat %s", argv[0]); 144 if ((sb.st_mode & S_IFDIR) == 0) 145 errx(1, "%s is not a directory", argv[0]); 146 147 PUFFSOP_INIT(pops); 148 puffs_null_setops(pops); 149 150 PUFFSOP_SET(pops, rot13, node, readdir); 151 PUFFSOP_SET(pops, rot13, node, read); 152 PUFFSOP_SET(pops, rot13, node, write); 153 154 if ((pu = puffs_init(pops, argv[0], "rot13", NULL, pflags)) == NULL) 155 err(1, "mount"); 156 157 pn_root = puffs_pn_new(pu, NULL); 158 if (pn_root == NULL) 159 err(1, "puffs_pn_new"); 160 puffs_setroot(pu, pn_root); 161 162 po_root = puffs_getrootpathobj(pu); 163 if (po_root == NULL) 164 err(1, "getrootpathobj"); 165 po_root->po_path = argv[0]; 166 po_root->po_len = strlen(argv[0]); 167 puffs_stat2vattr(&pn_root->pn_va, &sb); 168 169 puffs_set_namemod(pu, rot13path); 170 171 /* initialize rot13 tables */ 172 for (i = 0; i < 256; i++) 173 tbl[i] = (uint8_t)i; 174 for (i = 0; i <= 26; i++) 175 tbl[i + 'a'] = 'a' + ((i + 13) % 26); 176 for (i = 0; i < 26; i++) 177 tbl[i + 'A'] = 'A' + ((i + 13) % 26); 178 179 if (detach) 180 if (puffs_daemon(pu, 1, 1) == -1) 181 err(1, "puffs_daemon"); 182 183 if (puffs_mount(pu, argv[1], mntflags, pn_root) == -1) 184 err(1, "puffs_mount"); 185 if (puffs_mainloop(pu) == -1) 186 err(1, "mainloop"); 187 188 return 0; 189 } 190 191 int 192 rot13_node_readdir(struct puffs_usermount *pu, void *opc, struct dirent *dent, 193 off_t *readoff, size_t *reslen, const struct puffs_cred *pcr, 194 int *eofflag, off_t *cookies, size_t *ncookies) 195 { 196 struct dirent *dp; 197 size_t rl; 198 int rv; 199 200 dp = dent; 201 rl = *reslen; 202 203 rv = puffs_null_node_readdir(pu, opc, dent, readoff, reslen, pcr, 204 eofflag, cookies, ncookies); 205 if (rv) 206 return rv; 207 208 while (rl > *reslen) { 209 flipflop((uint8_t *)dp->d_name, dp->d_namlen); 210 rl -= _DIRENT_SIZE(dp); 211 dp = _DIRENT_NEXT(dp); 212 } 213 214 return 0; 215 } 216 217 int 218 rot13_node_read(struct puffs_usermount *pu, void *opc, 219 uint8_t *buf, off_t offset, size_t *resid, 220 const struct puffs_cred *pcr, int ioflag) 221 { 222 uint8_t *prebuf = buf; 223 size_t preres = *resid; 224 int rv; 225 226 rv = puffs_null_node_read(pu, opc, buf, offset, resid, pcr, ioflag); 227 if (rv) 228 return rv; 229 230 flipflop(prebuf, preres - *resid); 231 232 return rv; 233 } 234 235 int 236 rot13_node_write(struct puffs_usermount *pu, void *opc, 237 uint8_t *buf, off_t offset, size_t *resid, 238 const struct puffs_cred *pcr, int ioflag) 239 { 240 241 flipflop(buf, *resid); 242 return puffs_null_node_write(pu, opc, buf, offset, resid, pcr, ioflag); 243 } 244
Indexes created Tue Sep 30 20:09:53 GMT 2025