Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/fs/adfs/dir_fplus.c | |
4 | * | |
5 | * Copyright (C) 1997-1999 Russell King | |
1da177e4 | 6 | */ |
1da177e4 LT |
7 | #include "adfs.h" |
8 | #include "dir_fplus.h" | |
9 | ||
0db35a02 RK |
10 | /* Return the byte offset to directory entry pos */ |
11 | static unsigned int adfs_fplus_offset(const struct adfs_bigdirheader *h, | |
12 | unsigned int pos) | |
13 | { | |
14 | return offsetof(struct adfs_bigdirheader, bigdirname) + | |
15 | ALIGN(le32_to_cpu(h->bigdirnamelen), 4) + | |
16 | pos * sizeof(struct adfs_bigdirentry); | |
17 | } | |
18 | ||
6674ecab RK |
19 | static int adfs_fplus_validate_header(const struct adfs_bigdirheader *h) |
20 | { | |
21 | unsigned int size = le32_to_cpu(h->bigdirsize); | |
aa3d4e01 | 22 | unsigned int len; |
6674ecab RK |
23 | |
24 | if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 || | |
25 | h->bigdirversion[2] != 0 || | |
26 | h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME) || | |
aa3d4e01 RK |
27 | !size || size & 2047 || size > SZ_4M) |
28 | return -EIO; | |
29 | ||
30 | size -= sizeof(struct adfs_bigdirtail) + | |
31 | offsetof(struct adfs_bigdirheader, bigdirname); | |
32 | ||
33 | /* Check that bigdirnamelen fits within the directory */ | |
34 | len = ALIGN(le32_to_cpu(h->bigdirnamelen), 4); | |
35 | if (len > size) | |
36 | return -EIO; | |
37 | ||
38 | size -= len; | |
39 | ||
40 | /* Check that bigdirnamesize fits within the directory */ | |
41 | len = le32_to_cpu(h->bigdirnamesize); | |
42 | if (len > size) | |
43 | return -EIO; | |
44 | ||
45 | size -= len; | |
46 | ||
47 | /* | |
48 | * Avoid division, we know that absolute maximum number of entries | |
49 | * can not be so large to cause overflow of the multiplication below. | |
50 | */ | |
51 | len = le32_to_cpu(h->bigdirentries); | |
52 | if (len > SZ_4M / sizeof(struct adfs_bigdirentry) || | |
53 | len * sizeof(struct adfs_bigdirentry) > size) | |
6674ecab RK |
54 | return -EIO; |
55 | ||
56 | return 0; | |
57 | } | |
58 | ||
59 | static int adfs_fplus_validate_tail(const struct adfs_bigdirheader *h, | |
60 | const struct adfs_bigdirtail *t) | |
61 | { | |
62 | if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) || | |
63 | t->bigdirendmasseq != h->startmasseq || | |
64 | t->reserved[0] != 0 || t->reserved[1] != 0) | |
65 | return -EIO; | |
66 | ||
67 | return 0; | |
68 | } | |
69 | ||
d79288b4 RK |
70 | static u8 adfs_fplus_checkbyte(struct adfs_dir *dir) |
71 | { | |
72 | struct adfs_bigdirheader *h = dir->bighead; | |
73 | struct adfs_bigdirtail *t = dir->bigtail; | |
74 | unsigned int end, bs, bi, i; | |
75 | __le32 *bp; | |
76 | u32 dircheck; | |
77 | ||
78 | end = adfs_fplus_offset(h, le32_to_cpu(h->bigdirentries)) + | |
79 | le32_to_cpu(h->bigdirnamesize); | |
80 | ||
81 | /* Accumulate the contents of the header, entries and names */ | |
82 | for (dircheck = 0, bi = 0; end; bi++) { | |
83 | bp = (void *)dir->bhs[bi]->b_data; | |
84 | bs = dir->bhs[bi]->b_size; | |
85 | if (bs > end) | |
86 | bs = end; | |
87 | ||
88 | for (i = 0; i < bs; i += sizeof(u32)) | |
89 | dircheck = ror32(dircheck, 13) ^ le32_to_cpup(bp++); | |
90 | ||
91 | end -= bs; | |
92 | } | |
93 | ||
94 | /* Accumulate the contents of the tail except for the check byte */ | |
95 | dircheck = ror32(dircheck, 13) ^ le32_to_cpu(t->bigdirendname); | |
96 | dircheck = ror32(dircheck, 13) ^ t->bigdirendmasseq; | |
97 | dircheck = ror32(dircheck, 13) ^ t->reserved[0]; | |
98 | dircheck = ror32(dircheck, 13) ^ t->reserved[1]; | |
99 | ||
100 | return dircheck ^ dircheck >> 8 ^ dircheck >> 16 ^ dircheck >> 24; | |
101 | } | |
102 | ||
419a6e5e RK |
103 | static int adfs_fplus_read(struct super_block *sb, u32 indaddr, |
104 | unsigned int size, struct adfs_dir *dir) | |
1da177e4 LT |
105 | { |
106 | struct adfs_bigdirheader *h; | |
107 | struct adfs_bigdirtail *t; | |
419a6e5e RK |
108 | unsigned int dirsize; |
109 | int ret; | |
1da177e4 | 110 | |
419a6e5e RK |
111 | /* Read first buffer */ |
112 | ret = adfs_dir_read_buffers(sb, indaddr, sb->s_blocksize, dir); | |
113 | if (ret) | |
114 | return ret; | |
1da177e4 | 115 | |
016936b3 | 116 | dir->bighead = h = (void *)dir->bhs[0]->b_data; |
587065dc DC |
117 | ret = adfs_fplus_validate_header(h); |
118 | if (ret) { | |
6674ecab RK |
119 | adfs_error(sb, "dir %06x has malformed header", indaddr); |
120 | goto out; | |
121 | } | |
122 | ||
419a6e5e | 123 | dirsize = le32_to_cpu(h->bigdirsize); |
a464152f | 124 | if (size && dirsize != size) { |
ceb3b106 | 125 | adfs_msg(sb, KERN_WARNING, |
419a6e5e RK |
126 | "dir %06x header size %X does not match directory size %X", |
127 | indaddr, dirsize, size); | |
1da177e4 LT |
128 | } |
129 | ||
419a6e5e RK |
130 | /* Read remaining buffers */ |
131 | ret = adfs_dir_read_buffers(sb, indaddr, dirsize, dir); | |
132 | if (ret) | |
133 | return ret; | |
1da177e4 | 134 | |
016936b3 | 135 | dir->bigtail = t = (struct adfs_bigdirtail *) |
419a6e5e | 136 | (dir->bhs[dir->nr_buffers - 1]->b_data + (sb->s_blocksize - 8)); |
1da177e4 | 137 | |
6674ecab RK |
138 | ret = adfs_fplus_validate_tail(h, t); |
139 | if (ret) { | |
419a6e5e | 140 | adfs_error(sb, "dir %06x has malformed tail", indaddr); |
1da177e4 | 141 | goto out; |
2f09719a | 142 | } |
1da177e4 | 143 | |
d79288b4 RK |
144 | if (adfs_fplus_checkbyte(dir) != t->bigdircheckbyte) { |
145 | adfs_error(sb, "dir %06x checkbyte mismatch\n", indaddr); | |
146 | goto out; | |
147 | } | |
148 | ||
1da177e4 | 149 | dir->parent_id = le32_to_cpu(h->bigdirparent); |
1da177e4 | 150 | return 0; |
2f09719a | 151 | |
1da177e4 | 152 | out: |
1dd9f5ba | 153 | adfs_dir_relse(dir); |
2f09719a | 154 | |
1da177e4 LT |
155 | return ret; |
156 | } | |
157 | ||
158 | static int | |
159 | adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos) | |
160 | { | |
1da177e4 LT |
161 | int ret = -ENOENT; |
162 | ||
016936b3 | 163 | if (fpos <= le32_to_cpu(dir->bighead->bigdirentries)) { |
1da177e4 LT |
164 | dir->pos = fpos; |
165 | ret = 0; | |
166 | } | |
167 | ||
168 | return ret; | |
169 | } | |
170 | ||
1da177e4 LT |
171 | static int |
172 | adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj) | |
173 | { | |
016936b3 | 174 | struct adfs_bigdirheader *h = dir->bighead; |
1da177e4 LT |
175 | struct adfs_bigdirentry bde; |
176 | unsigned int offset; | |
a317120b | 177 | int ret; |
1da177e4 LT |
178 | |
179 | if (dir->pos >= le32_to_cpu(h->bigdirentries)) | |
a317120b | 180 | return -ENOENT; |
1da177e4 | 181 | |
0db35a02 | 182 | offset = adfs_fplus_offset(h, dir->pos); |
1da177e4 | 183 | |
a317120b RK |
184 | ret = adfs_dir_copyfrom(&bde, dir, offset, |
185 | sizeof(struct adfs_bigdirentry)); | |
186 | if (ret) | |
187 | return ret; | |
1da177e4 LT |
188 | |
189 | obj->loadaddr = le32_to_cpu(bde.bigdirload); | |
190 | obj->execaddr = le32_to_cpu(bde.bigdirexec); | |
191 | obj->size = le32_to_cpu(bde.bigdirlen); | |
5ed70bb4 | 192 | obj->indaddr = le32_to_cpu(bde.bigdirindaddr); |
1da177e4 LT |
193 | obj->attr = le32_to_cpu(bde.bigdirattr); |
194 | obj->name_len = le32_to_cpu(bde.bigdirobnamelen); | |
195 | ||
0db35a02 | 196 | offset = adfs_fplus_offset(h, le32_to_cpu(h->bigdirentries)); |
1da177e4 LT |
197 | offset += le32_to_cpu(bde.bigdirobnameptr); |
198 | ||
a317120b RK |
199 | ret = adfs_dir_copyfrom(obj->name, dir, offset, obj->name_len); |
200 | if (ret) | |
201 | return ret; | |
202 | ||
411c49bc | 203 | adfs_object_fixup(dir, obj); |
da23ef05 | 204 | |
1da177e4 | 205 | dir->pos += 1; |
a317120b RK |
206 | |
207 | return 0; | |
1da177e4 LT |
208 | } |
209 | ||
4287e4de RK |
210 | static int adfs_fplus_iterate(struct adfs_dir *dir, struct dir_context *ctx) |
211 | { | |
212 | struct object_info obj; | |
213 | ||
214 | if ((ctx->pos - 2) >> 32) | |
215 | return 0; | |
216 | ||
217 | if (adfs_fplus_setpos(dir, ctx->pos - 2)) | |
218 | return 0; | |
219 | ||
220 | while (!adfs_fplus_getnext(dir, &obj)) { | |
221 | if (!dir_emit(ctx, obj.name, obj.name_len, | |
222 | obj.indaddr, DT_UNKNOWN)) | |
223 | break; | |
224 | ctx->pos++; | |
225 | } | |
226 | ||
227 | return 0; | |
228 | } | |
229 | ||
a464152f RK |
230 | static int adfs_fplus_update(struct adfs_dir *dir, struct object_info *obj) |
231 | { | |
232 | struct adfs_bigdirheader *h = dir->bighead; | |
233 | struct adfs_bigdirentry bde; | |
234 | int offset, end, ret; | |
235 | ||
236 | offset = adfs_fplus_offset(h, 0) - sizeof(bde); | |
237 | end = adfs_fplus_offset(h, le32_to_cpu(h->bigdirentries)); | |
238 | ||
239 | do { | |
240 | offset += sizeof(bde); | |
241 | if (offset >= end) { | |
242 | adfs_error(dir->sb, "unable to locate entry to update"); | |
243 | return -ENOENT; | |
244 | } | |
245 | ret = adfs_dir_copyfrom(&bde, dir, offset, sizeof(bde)); | |
246 | if (ret) { | |
247 | adfs_error(dir->sb, "error reading directory entry"); | |
248 | return -ENOENT; | |
249 | } | |
250 | } while (le32_to_cpu(bde.bigdirindaddr) != obj->indaddr); | |
251 | ||
252 | bde.bigdirload = cpu_to_le32(obj->loadaddr); | |
253 | bde.bigdirexec = cpu_to_le32(obj->execaddr); | |
254 | bde.bigdirlen = cpu_to_le32(obj->size); | |
255 | bde.bigdirindaddr = cpu_to_le32(obj->indaddr); | |
256 | bde.bigdirattr = cpu_to_le32(obj->attr); | |
257 | ||
258 | return adfs_dir_copyto(dir, offset, &bde, sizeof(bde)); | |
259 | } | |
260 | ||
261 | static int adfs_fplus_commit(struct adfs_dir *dir) | |
262 | { | |
263 | int ret; | |
264 | ||
265 | /* Increment directory sequence number */ | |
266 | dir->bighead->startmasseq += 1; | |
267 | dir->bigtail->bigdirendmasseq += 1; | |
268 | ||
269 | /* Update directory check byte */ | |
270 | dir->bigtail->bigdircheckbyte = adfs_fplus_checkbyte(dir); | |
271 | ||
272 | /* Make sure the directory still validates correctly */ | |
273 | ret = adfs_fplus_validate_header(dir->bighead); | |
274 | if (ret == 0) | |
275 | ret = adfs_fplus_validate_tail(dir->bighead, dir->bigtail); | |
276 | ||
277 | return ret; | |
278 | } | |
279 | ||
0125f504 | 280 | const struct adfs_dir_ops adfs_fplus_dir_ops = { |
1da177e4 | 281 | .read = adfs_fplus_read, |
4287e4de | 282 | .iterate = adfs_fplus_iterate, |
1da177e4 LT |
283 | .setpos = adfs_fplus_setpos, |
284 | .getnext = adfs_fplus_getnext, | |
a464152f RK |
285 | .update = adfs_fplus_update, |
286 | .commit = adfs_fplus_commit, | |
1da177e4 | 287 | }; |