Bug Summary

File:src/usr.sbin/makefs/msdos/msdosfs_lookup.c
Warning:line 213, column 7
Although the value stored to 'rberror' is used in the enclosing expression, the value is never actually read from 'rberror'

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name msdosfs_lookup.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/usr.sbin/makefs/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/usr.sbin/makefs -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/usr.sbin/makefs/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c /usr/src/usr.sbin/makefs/msdos/msdosfs_lookup.c
1/* $OpenBSD: msdosfs_lookup.c,v 1.4 2021/10/06 00:40:41 deraadt Exp $ */
2/* $NetBSD: msdosfs_lookup.c,v 1.35 2016/01/30 09:59:27 mlelstv Exp $ */
3
4/*-
5 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
6 * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
7 * All rights reserved.
8 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by TooLs GmbH.
21 * 4. The name of TooLs GmbH may not be used to endorse or promote products
22 * derived from this software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
29 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
30 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
32 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
33 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35/*
36 * Written by Paul Popelka (paulp@uts.amdahl.com)
37 *
38 * You can do anything you want with this software, just don't say you wrote
39 * it, and don't remove this notice.
40 *
41 * This software is provided "as is".
42 *
43 * The author supplies this software to be publicly redistributed on the
44 * understanding that the author is not responsible for the correct
45 * functioning of this software in any circumstances and is not liable for
46 * any damages caused by this software.
47 *
48 * October 1992
49 */
50
51
52#include "ffs/buf.h"
53
54#include <msdosfs/bpb.h>
55#include "msdos/direntry.h"
56#include "msdos/denode.h"
57#include "msdos/msdosfsmount.h"
58#include "msdos/fat.h"
59
60
61
62/*
63 * dep - directory entry to copy into the directory
64 * ddep - directory to add to
65 * depp - return the address of the denode for the created directory entry
66 * if depp != 0
67 * cnp - componentname needed for Win95 long filenames
68 */
69int
70createde(struct denode *dep, struct denode *ddep, struct denode **depp, struct componentname *cnp)
71{
72 int error, rberror;
73 u_long dirclust, clusoffset;
74 u_long fndoffset, havecnt = 0, wcnt = 1, i;
75 struct direntry *ndep;
76 struct msdosfsmount *pmp = ddep->de_pmp;
77 struct mkfsbuf *bp;
78 daddr_t bn;
79 int blsize;
80#define async0 0
81
82#ifdef MSDOSFS_DEBUG
83 printf("createde(dep %p, ddep %p, depp %p, cnp %p)\n",
84 dep, ddep, depp, cnp);
85#endif
86
87 /*
88 * If no space left in the directory then allocate another cluster
89 * and chain it onto the end of the file. There is one exception
90 * to this. That is, if the root directory has no more space it
91 * can NOT be expanded. extendfile() checks for and fails attempts
92 * to extend the root directory. We just return an error in that
93 * case.
94 */
95 if (ddep->de_fndoffset >= ddep->de_FileSize) {
96 u_long needlen = ddep->de_fndoffset + sizeof(struct direntry)
97 - ddep->de_FileSize;
98 dirclust = de_clcount(pmp, needlen)(((needlen) + (pmp)->pm_bpcluster - 1) >> (pmp)->
pm_cnshift)
;
99 if ((error = extendfile(ddep, dirclust, 0, 0, DE_CLEAR1)) != 0) {
100 (void)detrunc(ddep, ddep->de_FileSize, 0);
101 goto err_norollback;
102 }
103
104 /*
105 * Update the size of the directory
106 */
107 ddep->de_FileSize += de_cn2off(pmp, dirclust)((dirclust) << (pmp)->pm_cnshift);
108 }
109
110 /*
111 * We just read in the cluster with space. Copy the new directory
112 * entry in. Then write it to disk. NOTE: DOS directories
113 * do not get smaller as clusters are emptied.
114 */
115 error = pcbmap(ddep, de_cluster(pmp, ddep->de_fndoffset)((ddep->de_fndoffset) >> (pmp)->pm_cnshift),
116 &bn, &dirclust, &blsize);
117 if (error)
118 goto err_norollback;
119 clusoffset = ddep->de_fndoffset;
120 if (dirclust != MSDOSFSROOT0)
121 clusoffset &= pmp->pm_crbomask;
122 if ((error = bread(pmp->pm_devvp, de_bn2kb(pmp, bn)((bn) << ((pmp)->pm_bnshift - 9)), blsize,
123 B_MODIFY0, &bp)) != 0) {
124 goto err_norollback;
125 }
126 ndep = bptoep(pmp, bp, clusoffset)((struct direntry *)(((char *)(bp)->b_data) + ((clusoffset
) & (pmp)->pm_crbomask)))
;
127
128 DE_EXTERNALIZE(ndep, dep)(memcpy((ndep)->deName, (dep)->de_Name, 11), (ndep)->
deAttributes = (dep)->de_Attributes, (ndep)->deCTimeHundredth
= (dep)->de_CHun, (*((u_int16_t *)((ndep)->deCTime)) =
((dep)->de_CTime)), (*((u_int16_t *)((ndep)->deCDate))
= ((dep)->de_CDate)), (*((u_int16_t *)((ndep)->deADate
)) = ((dep)->de_ADate)), (*((u_int16_t *)((ndep)->deMTime
)) = ((dep)->de_MTime)), (*((u_int16_t *)((ndep)->deMDate
)) = ((dep)->de_MDate)), (*((u_int16_t *)((ndep)->deStartCluster
)) = ((dep)->de_StartCluster)), (*((u_int32_t *)((ndep)->
deFileSize)) = (((dep)->de_Attributes & 0x10) ? 0 : (dep
)->de_FileSize)), (((dep)->de_pmp->pm_fatmask == 0x0fffffff
) ? (*((u_int16_t *)(((ndep))->deHighClust)) = (((dep))->
de_StartCluster >> 16)) : (*((u_int16_t *)(((ndep))->
deHighClust)) = (0))))
;
129
130 /*
131 * Now write the Win95 long name
132 */
133 if (ddep->de_fndcnt > 0) {
134 u_int8_t chksum = winChksum(ndep->deName);
135 u_char *un = cnp->cn_nameptr;
136 int unlen = cnp->cn_namelen;
137 u_long xhavecnt;
138
139 fndoffset = ddep->de_fndoffset;
140 xhavecnt = ddep->de_fndcnt + 1;
141
142 for(; wcnt < xhavecnt; wcnt++) {
143 if ((fndoffset & pmp->pm_crbomask) == 0) {
144 /* we should never get here if ddep is root
145 * directory */
146
147 if (async0)
148 (void) bdwrite(bp)bwrite(bp);
149 else if ((error = bwrite(bp)) != 0)
150 goto rollback;
151
152 fndoffset -= sizeof(struct direntry);
153 error = pcbmap(ddep,
154 de_cluster(pmp, fndoffset)((fndoffset) >> (pmp)->pm_cnshift),
155 &bn, 0, &blsize);
156 if (error)
157 goto rollback;
158
159 error = bread(pmp->pm_devvp, de_bn2kb(pmp, bn)((bn) << ((pmp)->pm_bnshift - 9)),
160 blsize, B_MODIFY0, &bp);
161 if (error) {
162 goto rollback;
163 }
164 ndep = bptoep(pmp, bp,((struct direntry *)(((char *)(bp)->b_data) + ((fndoffset &
pmp->pm_crbomask) & (pmp)->pm_crbomask)))
165 fndoffset & pmp->pm_crbomask)((struct direntry *)(((char *)(bp)->b_data) + ((fndoffset &
pmp->pm_crbomask) & (pmp)->pm_crbomask)))
;
166 } else {
167 ndep--;
168 fndoffset -= sizeof(struct direntry);
169 }
170 if (!unix2winfn(un, unlen, (struct winentry *)ndep,
171 wcnt, chksum))
172 break;
173 }
174 }
175
176 if (async0)
177 bdwrite(bp)bwrite(bp);
178 else if ((error = bwrite(bp)) != 0)
179 goto rollback;
180
181 /*
182 * If they want us to return with the denode gotten.
183 */
184 if (depp) {
185 u_long diroffset = clusoffset;
186
187 if (dep->de_Attributes & ATTR_DIRECTORY0x10) {
188 dirclust = dep->de_StartCluster;
189 if (FAT32(pmp)(pmp->pm_fatmask == 0x0fffffff) && dirclust == pmp->pm_rootdirblk)
190 dirclust = MSDOSFSROOT0;
191 if (dirclust == MSDOSFSROOT0)
192 diroffset = MSDOSFSROOT_OFS0x1fffffff;
193 else
194 diroffset = 0;
195 }
196 error = deget(pmp, dirclust, diroffset, depp);
197 return error;
198 }
199
200 return 0;
201
202 rollback:
203 /*
204 * Mark all slots modified so far as deleted. Note that we
205 * can't just call removede(), since directory is not in
206 * consistent state.
207 */
208 fndoffset = ddep->de_fndoffset;
209 rberror = pcbmap(ddep, de_cluster(pmp, fndoffset)((fndoffset) >> (pmp)->pm_cnshift),
210 &bn, NULL((void*)0), &blsize);
211 if (rberror)
212 goto err_norollback;
213 if ((rberror = bread(pmp->pm_devvp, de_bn2kb(pmp, bn)((bn) << ((pmp)->pm_bnshift - 9)), blsize,
Although the value stored to 'rberror' is used in the enclosing expression, the value is never actually read from 'rberror'
214 B_MODIFY0, &bp)) != 0) {
215 goto err_norollback;
216 }
217 ndep = bptoep(pmp, bp, clusoffset)((struct direntry *)(((char *)(bp)->b_data) + ((clusoffset
) & (pmp)->pm_crbomask)))
;
218
219 havecnt = ddep->de_fndcnt + 1;
220 for(i = wcnt; i <= havecnt; i++) {
221 /* mark entry as deleted */
222 ndep->deName[0] = SLOT_DELETED0xe5;
223
224 if ((fndoffset & pmp->pm_crbomask) == 0) {
225 /* we should never get here if ddep is root
226 * directory */
227
228 if (async0)
229 bdwrite(bp)bwrite(bp);
230 else if ((rberror = bwrite(bp)) != 0)
231 goto err_norollback;
232
233 fndoffset -= sizeof(struct direntry);
234 rberror = pcbmap(ddep,
235 de_cluster(pmp, fndoffset)((fndoffset) >> (pmp)->pm_cnshift),
236 &bn, 0, &blsize);
237 if (rberror)
238 goto err_norollback;
239
240 rberror = bread(pmp->pm_devvp, de_bn2kb(pmp, bn)((bn) << ((pmp)->pm_bnshift - 9)),
241 blsize, B_MODIFY0, &bp);
242 if (rberror) {
243 goto err_norollback;
244 }
245 ndep = bptoep(pmp, bp, fndoffset)((struct direntry *)(((char *)(bp)->b_data) + ((fndoffset)
& (pmp)->pm_crbomask)))
;
246 } else {
247 ndep--;
248 fndoffset -= sizeof(struct direntry);
249 }
250 }
251
252 /* ignore any further error */
253 if (async0)
254 (void) bdwrite(bp)bwrite(bp);
255 else
256 (void) bwrite(bp);
257
258 err_norollback:
259 return error;
260}
261
262/*
263 * Read in the disk block containing the directory entry (dirclu, dirofs)
264 * and return the address of the buf header, and the address of the
265 * directory entry within the block.
266 */
267int
268readep(struct msdosfsmount *pmp, u_long dirclust, u_long diroffset, struct mkfsbuf **bpp, struct direntry **epp)
269{
270 int error;
271 daddr_t bn;
272 int blsize;
273
274 blsize = pmp->pm_bpcluster;
275 if (dirclust == MSDOSFSROOT0
276 && de_blk(pmp, diroffset + blsize)((((((diroffset + blsize)) >> ((pmp))->pm_cnshift)) <<
((pmp)->pm_cnshift - (pmp)->pm_bnshift)))
> pmp->pm_rootdirsize)
277 blsize = de_bn2off(pmp, pmp->pm_rootdirsize)((pmp->pm_rootdirsize) << (pmp)->pm_bnshift) & pmp->pm_crbomask;
278 bn = detobn(pmp, dirclust, diroffset)((dirclust) == 0 ? (((((((((diroffset)))) >> ((((pmp)))
)->pm_cnshift)) << ((((pmp)))->pm_cnshift - (((pmp
)))->pm_bnshift))) + ((pmp))->pm_rootdirblk) : (((((dirclust
))-2) << ((((pmp)))->pm_cnshift - (((pmp)))->pm_bnshift
)) + ((pmp))->pm_firstcluster))
;
279 if ((error = bread(pmp->pm_devvp, de_bn2kb(pmp, bn)((bn) << ((pmp)->pm_bnshift - 9)), blsize,
280 0, bpp)) != 0) {
281 *bpp = NULL((void*)0);
282 return (error);
283 }
284 if (epp)
285 *epp = bptoep(pmp, *bpp, diroffset)((struct direntry *)(((char *)(*bpp)->b_data) + ((diroffset
) & (pmp)->pm_crbomask)))
;
286 return (0);
287}
288
289/*
290 * Read in the disk block containing the directory entry dep came from and
291 * return the address of the buf header, and the address of the directory
292 * entry within the block.
293 */
294int
295readde(struct denode *dep, struct mkfsbuf **bpp, struct direntry **epp)
296{
297 return (readep(dep->de_pmp, dep->de_dirclustde_key.dk_dirclust, dep->de_diroffsetde_key.dk_diroffset,
298 bpp, epp));
299}
300
301/*
302 * Create a unique DOS name in dvp
303 */
304int
305uniqdosname(struct denode *dep, struct componentname *cnp, u_char *cp)
306{
307 struct msdosfsmount *pmp = dep->de_pmp;
308 struct direntry *dentp;
309 int gen;
310 int blsize;
311 u_long cn;
312 daddr_t bn;
313 struct mkfsbuf *bp;
314 int error;
315
316 for (gen = 1;; gen++) {
317 /*
318 * Generate DOS name with generation number
319 */
320 if (!unix2dosfn(cnp->cn_nameptr, cp, cnp->cn_namelen, gen))
321 return gen == 1 ? EINVAL22 : EEXIST17;
322
323 /*
324 * Now look for a dir entry with this exact name
325 */
326 for (cn = error = 0; !error; cn++) {
327 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) {
328 if (error == E2BIG7) /* EOF reached and not found */
329 return 0;
330 return error;
331 }
332 error = bread(pmp->pm_devvp, de_bn2kb(pmp, bn)((bn) << ((pmp)->pm_bnshift - 9)), blsize,
333 0, &bp);
334 if (error) {
335 return error;
336 }
337 for (dentp = (struct direntry *)bp->b_data;
338 (char *)dentp < (char *)bp->b_data + blsize;
339 dentp++) {
340 if (dentp->deName[0] == SLOT_EMPTY0x00) {
341 /*
342 * Last used entry and not found
343 */
344 brelse(bp, 0);
345 return 0;
346 }
347 /*
348 * Ignore volume labels and Win95 entries
349 */
350 if (dentp->deAttributes & ATTR_VOLUME0x08)
351 continue;
352 if (!memcmp(dentp->deName, cp, 11)) {
353 error = EEXIST17;
354 break;
355 }
356 }
357 brelse(bp, 0);
358 }
359 }
360}