1 // SPDX-License-Identifier: GPL-2.0-only 1
2 /*
3 * misc.c
4 *
5 * PURPOSE
6 * Miscellaneous routines for the OSTA-UD
7 *
8 * COPYRIGHT
9 * (C) 1998 Dave Boynton
10 * (C) 1998-2004 Ben Fennema
11 * (C) 1999-2000 Stelias Computing Inc
12 *
13 * HISTORY
14 *
15 * 04/19/99 blf partial support for reading/
16 */
17
18 #include "udfdecl.h"
19
20 #include <linux/fs.h>
21 #include <linux/string.h>
22 #include <linux/crc-itu-t.h>
23
24 #include "udf_i.h"
25 #include "udf_sb.h"
26
27 struct genericFormat *udf_add_extendedattr(str
28 uin
29 {
30 uint8_t *ea = NULL, *ad = NULL;
31 int offset;
32 uint16_t crclen;
33 struct udf_inode_info *iinfo = UDF_I(i
34
35 ea = iinfo->i_data;
36 if (iinfo->i_lenEAttr) {
37 ad = iinfo->i_data + iinfo->i_
38 } else {
39 ad = ea;
40 size += sizeof(struct extended
41 }
42
43 offset = inode->i_sb->s_blocksize - ud
44 iinfo->i_lenAlloc;
45
46 /* TODO - Check for FreeEASpace */
47
48 if (loc & 0x01 && offset >= size) {
49 struct extendedAttrHeaderDesc
50 eahd = (struct extendedAttrHea
51
52 if (iinfo->i_lenAlloc)
53 memmove(&ad[size], ad,
54
55 if (iinfo->i_lenEAttr) {
56 /* check checksum/crc
57 if (eahd->descTag.tagI
58 cpu_to
59 le32_to_cpu(eahd->
60 iinfo-
61 return NULL;
62 } else {
63 struct udf_sb_info *sb
64
65 size -= sizeof(struct
66 iinfo->i_lenEAttr +=
67 sizeof(struct
68 eahd->descTag.tagIdent
69 if (sbi->s_udfrev >= 0
70 eahd->descTag.
71 else
72 eahd->descTag.
73 eahd->descTag.tagSeria
74 cpu_to
75 eahd->descTag.tagLocat
76 iinfo-
77 eahd->impAttrLocation
78 eahd->appAttrLocation
79 }
80
81 offset = iinfo->i_lenEAttr;
82 if (type < 2048) {
83 if (le32_to_cpu(eahd->
84 iinfo-
85 uint32_t aal =
86 le32_t
87 memmove(&ea[of
88 &ea[aa
89 offset -= aal;
90 eahd->appAttrL
91
92 }
93 if (le32_to_cpu(eahd->
94 iinfo-
95 uint32_t ial =
96 le32_t
97 memmove(&ea[of
98 &ea[ia
99 offset -= ial;
100 eahd->impAttrL
101
102 }
103 } else if (type < 65536) {
104 if (le32_to_cpu(eahd->
105 iinfo-
106 uint32_t aal =
107 le32_t
108 memmove(&ea[of
109 &ea[aa
110 offset -= aal;
111 eahd->appAttrL
112
113 }
114 }
115 /* rewrite CRC + checksum of e
116 crclen = sizeof(struct extende
117 eahd->descTag.descCRCLength =
118 eahd->descTag.descCRC = cpu_to
119
120 eahd->descTag.tagChecksum = ud
121 iinfo->i_lenEAttr += size;
122 return (struct genericFormat *
123 }
124
125 return NULL;
126 }
127
128 struct genericFormat *udf_get_extendedattr(str
129 uin
130 {
131 struct genericFormat *gaf;
132 uint8_t *ea = NULL;
133 uint32_t offset;
134 struct udf_inode_info *iinfo = UDF_I(i
135
136 ea = iinfo->i_data;
137
138 if (iinfo->i_lenEAttr) {
139 struct extendedAttrHeaderDesc
140 eahd = (struct extendedAttrHea
141
142 /* check checksum/crc */
143 if (eahd->descTag.tagIdent !=
144 cpu_to_le16(TA
145 le32_to_cpu(eahd->descTag.
146 iinfo->i_locat
147 return NULL;
148
149 if (type < 2048)
150 offset = sizeof(struct
151 else if (type < 65536)
152 offset = le32_to_cpu(e
153 else
154 offset = le32_to_cpu(e
155
156 while (offset + sizeof(*gaf) <
157 uint32_t attrLength;
158
159 gaf = (struct genericF
160 attrLength = le32_to_c
161
162 /* Detect undersized e
163 if ((attrLength < size
164 (attrLength > (iin
165 break;
166
167 if (le32_to_cpu(gaf->a
168 gaf->a
169 return gaf;
170 else
171 offset += attr
172 }
173 }
174
175 return NULL;
176 }
177
178 /*
179 * udf_read_tagged
180 *
181 * PURPOSE
182 * Read the first block of a tagged descr
183 *
184 * HISTORY
185 * July 1, 1997 - Andrew E. Mileski
186 * Written, tested, and released.
187 */
188 struct buffer_head *udf_read_tagged(struct sup
189 uint32_t l
190 {
191 struct tag *tag_p;
192 struct buffer_head *bh = NULL;
193 u8 checksum;
194
195 /* Read the block */
196 if (block == 0xFFFFFFFF)
197 return NULL;
198
199 bh = sb_bread(sb, block);
200 if (!bh) {
201 udf_err(sb, "read failed, bloc
202 block, location);
203 return NULL;
204 }
205
206 tag_p = (struct tag *)(bh->b_data);
207
208 *ident = le16_to_cpu(tag_p->tagIdent);
209
210 if (location != le32_to_cpu(tag_p->tag
211 udf_debug("location mismatch b
212 block, le32_to_cpu(t
213 goto error_out;
214 }
215
216 /* Verify the tag checksum */
217 checksum = udf_tag_checksum(tag_p);
218 if (checksum != tag_p->tagChecksum) {
219 udf_err(sb, "tag checksum fail
220 block, checksum, tag_p
221 goto error_out;
222 }
223
224 /* Verify the tag version */
225 if (tag_p->descVersion != cpu_to_le16(
226 tag_p->descVersion != cpu_to_le16(
227 udf_err(sb, "tag version 0x%04
228 le16_to_cpu(tag_p->des
229 goto error_out;
230 }
231
232 /* Verify the descriptor CRC */
233 if (le16_to_cpu(tag_p->descCRCLength)
234 le16_to_cpu(tag_p->descCRC) == crc
235 bh->b_
236 le16_t
237 return bh;
238
239 udf_debug("Crc failure block %u: crc =
240 le16_to_cpu(tag_p->descCRC),
241 le16_to_cpu(tag_p->descCRCLe
242 error_out:
243 brelse(bh);
244 return NULL;
245 }
246
247 struct buffer_head *udf_read_ptagged(struct su
248 struct ke
249 uint32_t
250 {
251 return udf_read_tagged(sb, udf_get_lb_
252 loc->logicalBlo
253 }
254
255 void udf_update_tag(char *data, int length)
256 {
257 struct tag *tptr = (struct tag *)data;
258 length -= sizeof(struct tag);
259
260 tptr->descCRCLength = cpu_to_le16(leng
261 tptr->descCRC = cpu_to_le16(crc_itu_t(
262 tptr->tagChecksum = udf_tag_checksum(t
263 }
264
265 void udf_new_tag(char *data, uint16_t ident, u
266 uint32_t loc, int length)
267 {
268 struct tag *tptr = (struct tag *)data;
269 tptr->tagIdent = cpu_to_le16(ident);
270 tptr->descVersion = cpu_to_le16(versio
271 tptr->tagSerialNum = cpu_to_le16(snum)
272 tptr->tagLocation = cpu_to_le32(loc);
273 udf_update_tag(data, length);
274 }
275
276 u8 udf_tag_checksum(const struct tag *t)
277 {
278 u8 *data = (u8 *)t;
279 u8 checksum = 0;
280 int i;
281 for (i = 0; i < sizeof(struct tag); ++
282 if (i != 4) /* position of che
283 checksum += data[i];
284 return checksum;
285 }
286
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