1 /* $FreeBSD$ */ 2 /* $NetBSD: msdosfs_lookup.c,v 1.37 1997/11/17 15:36:54 ws Exp $ */ 3 4 /*- 5 * SPDX-License-Identifier: BSD-4-Clause 6 * 7 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank. 8 * Copyright (C) 1994, 1995, 1997 TooLs GmbH. 9 * All rights reserved. 10 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below). 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by TooLs GmbH. 23 * 4. The name of TooLs GmbH may not be used to endorse or promote products 24 * derived from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 29 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 31 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 32 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 33 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 34 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 35 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 */ 37 /*- 38 * Written by Paul Popelka (paulp@uts.amdahl.com) 39 * 40 * You can do anything you want with this software, just don't say you wrote 41 * it, and don't remove this notice. 42 * 43 * This software is provided "as is". 44 * 45 * The author supplies this software to be publicly redistributed on the 46 * understanding that the author is not responsible for the correct 47 * functioning of this software in any circumstances and is not liable for 48 * any damages caused by this software. 49 * 50 * October 1992 51 */ 52 53 #include <sys/param.h> 54 #include <sys/errno.h> 55 56 #include <stdbool.h> 57 #include <stdio.h> 58 #include <string.h> 59 60 #include "ffs/buf.h" 61 #include <fs/msdosfs/bpb.h> 62 #include "msdos/direntry.h" 63 #include <fs/msdosfs/denode.h> 64 #include <fs/msdosfs/fat.h> 65 #include <fs/msdosfs/msdosfsmount.h> 66 67 #include "makefs.h" 68 #include "msdos.h" 69 70 /* 71 * dep - directory entry to copy into the directory 72 * ddep - directory to add to 73 * depp - return the address of the denode for the created directory entry 74 * if depp != 0 75 * cnp - componentname needed for Win95 long filenames 76 */ 77 int 78 createde(struct denode *dep, struct denode *ddep, struct denode **depp, 79 struct componentname *cnp) 80 { 81 int error; 82 u_long dirclust, diroffset; 83 struct direntry *ndep; 84 struct msdosfsmount *pmp = ddep->de_pmp; 85 struct buf *bp; 86 daddr_t bn; 87 int blsize; 88 89 MSDOSFS_DPRINTF(("createde(dep %p, ddep %p, depp %p, cnp %p)\n", 90 dep, ddep, depp, cnp)); 91 92 /* 93 * If no space left in the directory then allocate another cluster 94 * and chain it onto the end of the file. There is one exception 95 * to this. That is, if the root directory has no more space it 96 * can NOT be expanded. extendfile() checks for and fails attempts 97 * to extend the root directory. We just return an error in that 98 * case. 99 */ 100 if (ddep->de_fndoffset >= ddep->de_FileSize) { 101 diroffset = ddep->de_fndoffset + sizeof(struct direntry) 102 - ddep->de_FileSize; 103 dirclust = de_clcount(pmp, diroffset); 104 error = extendfile(ddep, dirclust, 0, 0, DE_CLEAR); 105 if (error) { 106 (void)detrunc(ddep, ddep->de_FileSize, 0, NULL); 107 return error; 108 } 109 110 /* 111 * Update the size of the directory 112 */ 113 ddep->de_FileSize += de_cn2off(pmp, dirclust); 114 } 115 116 /* 117 * We just read in the cluster with space. Copy the new directory 118 * entry in. Then write it to disk. NOTE: DOS directories 119 * do not get smaller as clusters are emptied. 120 */ 121 error = pcbmap(ddep, de_cluster(pmp, ddep->de_fndoffset), 122 &bn, &dirclust, &blsize); 123 if (error) 124 return error; 125 diroffset = ddep->de_fndoffset; 126 if (dirclust != MSDOSFSROOT) 127 diroffset &= pmp->pm_crbomask; 128 if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp)) != 0) { 129 brelse(bp); 130 return error; 131 } 132 ndep = bptoep(pmp, bp, ddep->de_fndoffset); 133 134 DE_EXTERNALIZE(ndep, dep); 135 136 /* 137 * Now write the Win95 long name 138 */ 139 if (ddep->de_fndcnt > 0) { 140 uint8_t chksum = winChksum(ndep->deName); 141 const u_char *un = (const u_char *)cnp->cn_nameptr; 142 int unlen = cnp->cn_namelen; 143 int cnt = 1; 144 145 while (--ddep->de_fndcnt >= 0) { 146 if (!(ddep->de_fndoffset & pmp->pm_crbomask)) { 147 if ((error = bwrite(bp)) != 0) 148 return error; 149 150 ddep->de_fndoffset -= sizeof(struct direntry); 151 error = pcbmap(ddep, 152 de_cluster(pmp, 153 ddep->de_fndoffset), 154 &bn, 0, &blsize); 155 if (error) 156 return error; 157 158 error = bread(pmp->pm_devvp, bn, blsize, 159 NOCRED, &bp); 160 if (error) { 161 brelse(bp); 162 return error; 163 } 164 ndep = bptoep(pmp, bp, ddep->de_fndoffset); 165 } else { 166 ndep--; 167 ddep->de_fndoffset -= sizeof(struct direntry); 168 } 169 if (!unix2winfn(un, unlen, (struct winentry *)ndep, 170 cnt++, chksum)) 171 break; 172 } 173 } 174 175 if ((error = bwrite(bp)) != 0) 176 return error; 177 178 /* 179 * If they want us to return with the denode gotten. 180 */ 181 if (depp) { 182 if (dep->de_Attributes & ATTR_DIRECTORY) { 183 dirclust = dep->de_StartCluster; 184 if (FAT32(pmp) && dirclust == pmp->pm_rootdirblk) 185 dirclust = MSDOSFSROOT; 186 if (dirclust == MSDOSFSROOT) 187 diroffset = MSDOSFSROOT_OFS; 188 else 189 diroffset = 0; 190 } 191 return deget(pmp, dirclust, diroffset, depp); 192 } 193 194 return 0; 195 } 196 197 /* 198 * Read in the disk block containing the directory entry (dirclu, dirofs) 199 * and return the address of the buf header, and the address of the 200 * directory entry within the block. 201 */ 202 int 203 readep(struct msdosfsmount *pmp, u_long dirclust, u_long diroffset, 204 struct buf **bpp, struct direntry **epp) 205 { 206 int error; 207 daddr_t bn; 208 int blsize; 209 210 blsize = pmp->pm_bpcluster; 211 if (dirclust == MSDOSFSROOT 212 && de_blk(pmp, diroffset + blsize) > pmp->pm_rootdirsize) 213 blsize = de_bn2off(pmp, pmp->pm_rootdirsize) & pmp->pm_crbomask; 214 bn = detobn(pmp, dirclust, diroffset); 215 if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, bpp)) != 0) { 216 brelse(*bpp); 217 *bpp = NULL; 218 return (error); 219 } 220 if (epp) 221 *epp = bptoep(pmp, *bpp, diroffset); 222 return (0); 223 } 224 225 /* 226 * Read in the disk block containing the directory entry dep came from and 227 * return the address of the buf header, and the address of the directory 228 * entry within the block. 229 */ 230 int 231 readde(struct denode *dep, struct buf **bpp, struct direntry **epp) 232 { 233 234 return (readep(dep->de_pmp, dep->de_dirclust, dep->de_diroffset, 235 bpp, epp)); 236 } 237 238 /* 239 * Create a unique DOS name in dvp 240 */ 241 int 242 uniqdosname(struct denode *dep, struct componentname *cnp, u_char *cp) 243 { 244 struct msdosfsmount *pmp = dep->de_pmp; 245 struct direntry *dentp; 246 int gen; 247 int blsize; 248 u_long cn; 249 daddr_t bn; 250 struct buf *bp; 251 int error; 252 253 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) 254 return (unix2dosfn((const u_char *)cnp->cn_nameptr, cp, 255 cnp->cn_namelen, 0) ? 0 : EINVAL); 256 257 for (gen = 1;; gen++) { 258 /* 259 * Generate DOS name with generation number 260 */ 261 if (!unix2dosfn((const u_char *)cnp->cn_nameptr, cp, 262 cnp->cn_namelen, gen)) 263 return gen == 1 ? EINVAL : EEXIST; 264 265 /* 266 * Now look for a dir entry with this exact name 267 */ 268 for (cn = error = 0; !error; cn++) { 269 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) { 270 if (error == E2BIG) /* EOF reached and not found */ 271 return 0; 272 return error; 273 } 274 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp); 275 if (error) { 276 brelse(bp); 277 return error; 278 } 279 for (dentp = (struct direntry *)bp->b_data; 280 (char *)dentp < bp->b_data + blsize; 281 dentp++) { 282 if (dentp->deName[0] == SLOT_EMPTY) { 283 /* 284 * Last used entry and not found 285 */ 286 brelse(bp); 287 return 0; 288 } 289 /* 290 * Ignore volume labels and Win95 entries 291 */ 292 if (dentp->deAttributes & ATTR_VOLUME) 293 continue; 294 if (!bcmp(dentp->deName, cp, 11)) { 295 error = EEXIST; 296 break; 297 } 298 } 299 brelse(bp); 300 } 301 } 302 } 303