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 <vfs/msdosfs/bpb.h>
61 #include "msdos/denode.h"
62 #include <vfs/msdosfs/fat.h>
63 #include <vfs/msdosfs/msdosfsmount.h>
64
65 #include "makefs.h"
66 #include "msdos.h"
67
68 /*
69 * dep - directory entry to copy into the directory
70 * ddep - directory to add to
71 * depp - return the address of the denode for the created directory entry
72 * if depp != 0
73 * cnp - componentname needed for Win95 long filenames
74 */
75 int
createde(struct denode * dep,struct denode * ddep,struct denode ** depp,struct componentname * cnp)76 createde(struct denode *dep, struct denode *ddep, struct denode **depp,
77 struct componentname *cnp)
78 {
79 int error;
80 u_long dirclust, diroffset;
81 struct direntry *ndep;
82 struct msdosfsmount *pmp = ddep->de_pmp;
83 struct m_buf *bp;
84 daddr_t bn;
85 int blsize;
86
87 MSDOSFS_DPRINTF(("createde(dep %p, ddep %p, depp %p, cnp %p)\n",
88 dep, ddep, depp, cnp));
89
90 /*
91 * If no space left in the directory then allocate another cluster
92 * and chain it onto the end of the file. There is one exception
93 * to this. That is, if the root directory has no more space it
94 * can NOT be expanded. extendfile() checks for and fails attempts
95 * to extend the root directory. We just return an error in that
96 * case.
97 */
98 if (ddep->de_fndoffset >= ddep->de_FileSize) {
99 diroffset = ddep->de_fndoffset + sizeof(struct direntry)
100 - ddep->de_FileSize;
101 dirclust = de_clcount(pmp, diroffset);
102 error = m_extendfile(ddep, dirclust, 0, 0, DE_CLEAR);
103 if (error) {
104 (void)detrunc(ddep, ddep->de_FileSize, 0);
105 return error;
106 }
107
108 /*
109 * Update the size of the directory
110 */
111 ddep->de_FileSize += de_cn2off(pmp, dirclust);
112 }
113
114 /*
115 * We just read in the cluster with space. Copy the new directory
116 * entry in. Then write it to disk. NOTE: DOS directories
117 * do not get smaller as clusters are emptied.
118 */
119 error = pcbmap(ddep, de_cluster(pmp, ddep->de_fndoffset),
120 &bn, &dirclust, &blsize);
121 if (error)
122 return error;
123 diroffset = ddep->de_fndoffset;
124 if (dirclust != MSDOSFSROOT)
125 diroffset &= pmp->pm_crbomask;
126 if ((error = bread((void *)pmp->pm_devvp, bn, blsize, NOCRED,
127 &bp)) != 0) {
128 brelse(bp);
129 return error;
130 }
131 ndep = bptoep(pmp, bp, ddep->de_fndoffset);
132
133 DE_EXTERNALIZE(ndep, dep);
134
135 /*
136 * Now write the Win95 long name
137 */
138 if (ddep->de_fndcnt > 0) {
139 uint8_t chksum = winChksum(ndep->deName);
140 const u_char *un = (const u_char *)cnp->cn_nameptr;
141 int unlen = cnp->cn_namelen;
142 int cnt = 1;
143
144 while (--ddep->de_fndcnt >= 0) {
145 if (!(ddep->de_fndoffset & pmp->pm_crbomask)) {
146 if ((error = bwrite(bp)) != 0)
147 return error;
148
149 ddep->de_fndoffset -= sizeof(struct direntry);
150 error = pcbmap(ddep,
151 de_cluster(pmp,
152 ddep->de_fndoffset),
153 &bn, 0, &blsize);
154 if (error)
155 return error;
156
157 error = bread((void *)pmp->pm_devvp, bn, blsize,
158 NOCRED, &bp);
159 if (error) {
160 brelse(bp);
161 return error;
162 }
163 ndep = bptoep(pmp, bp, ddep->de_fndoffset);
164 } else {
165 ndep--;
166 ddep->de_fndoffset -= sizeof(struct direntry);
167 }
168 if (!unix2winfn(un, unlen, (struct winentry *)ndep,
169 cnt++, chksum))
170 break;
171 }
172 }
173
174 if ((error = bwrite(bp)) != 0)
175 return error;
176
177 /*
178 * If they want us to return with the denode gotten.
179 */
180 if (depp) {
181 if (dep->de_Attributes & ATTR_DIRECTORY) {
182 dirclust = dep->de_StartCluster;
183 if (FAT32(pmp) && dirclust == pmp->pm_rootdirblk)
184 dirclust = MSDOSFSROOT;
185 if (dirclust == MSDOSFSROOT)
186 diroffset = MSDOSFSROOT_OFS;
187 else
188 diroffset = 0;
189 }
190 return deget(pmp, dirclust, diroffset, depp);
191 }
192
193 return 0;
194 }
195
196 /*
197 * Read in the disk block containing the directory entry (dirclu, dirofs)
198 * and return the address of the buf header, and the address of the
199 * directory entry within the block.
200 */
201 int
m_readep(struct msdosfsmount * pmp,u_long dirclust,u_long diroffset,struct m_buf ** bpp,struct direntry ** epp)202 m_readep(struct msdosfsmount *pmp, u_long dirclust, u_long diroffset,
203 struct m_buf **bpp, struct direntry **epp)
204 {
205 int error;
206 daddr_t bn;
207 int blsize;
208
209 blsize = pmp->pm_bpcluster;
210 if (dirclust == MSDOSFSROOT
211 && de_blk(pmp, diroffset + blsize) > pmp->pm_rootdirsize)
212 blsize = de_bn2off(pmp, pmp->pm_rootdirsize) & pmp->pm_crbomask;
213 bn = detobn(pmp, dirclust, diroffset);
214 if ((error = bread((void *)pmp->pm_devvp, bn, blsize, NOCRED,
215 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
m_readde(struct denode * dep,struct m_buf ** bpp,struct direntry ** epp)231 m_readde(struct denode *dep, struct m_buf **bpp, struct direntry **epp)
232 {
233
234 return (m_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
uniqdosname(struct denode * dep,struct componentname * cnp,u_char * cp)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 m_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((void *)pmp->pm_devvp, bn, blsize,
275 NOCRED, &bp);
276 if (error) {
277 brelse(bp);
278 return error;
279 }
280 for (dentp = (struct direntry *)bp->b_data;
281 (char *)dentp < (char *)bp->b_data + blsize;
282 dentp++) {
283 if (dentp->deName[0] == SLOT_EMPTY) {
284 /*
285 * Last used entry and not found
286 */
287 brelse(bp);
288 return 0;
289 }
290 /*
291 * Ignore volume labels and Win95 entries
292 */
293 if (dentp->deAttributes & ATTR_VOLUME)
294 continue;
295 if (!bcmp(dentp->deName, cp, 11)) {
296 error = EEXIST;
297 break;
298 }
299 }
300 brelse(bp);
301 }
302 }
303 }
304