1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * misc.c |
4 | * |
5 | * PURPOSE |
6 | * Miscellaneous routines for the OSTA-UDF(tm) filesystem. |
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/writing specific EA's |
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(struct inode *inode, uint32_t size, |
28 | uint32_t type, uint8_t loc) |
29 | { |
30 | uint8_t *ea = NULL, *ad = NULL; |
31 | int offset; |
32 | uint16_t crclen; |
33 | struct udf_inode_info *iinfo = UDF_I(inode); |
34 | |
35 | ea = iinfo->i_data; |
36 | if (iinfo->i_lenEAttr) { |
37 | ad = iinfo->i_data + iinfo->i_lenEAttr; |
38 | } else { |
39 | ad = ea; |
40 | size += sizeof(struct extendedAttrHeaderDesc); |
41 | } |
42 | |
43 | offset = inode->i_sb->s_blocksize - udf_file_entry_alloc_offset(inode) - |
44 | iinfo->i_lenAlloc; |
45 | |
46 | /* TODO - Check for FreeEASpace */ |
47 | |
48 | if (loc & 0x01 && offset >= size) { |
49 | struct extendedAttrHeaderDesc *eahd; |
50 | eahd = (struct extendedAttrHeaderDesc *)ea; |
51 | |
52 | if (iinfo->i_lenAlloc) |
53 | memmove(&ad[size], ad, iinfo->i_lenAlloc); |
54 | |
55 | if (iinfo->i_lenEAttr) { |
56 | /* check checksum/crc */ |
57 | if (eahd->descTag.tagIdent != |
58 | cpu_to_le16(TAG_IDENT_EAHD) || |
59 | le32_to_cpu(eahd->descTag.tagLocation) != |
60 | iinfo->i_location.logicalBlockNum) |
61 | return NULL; |
62 | } else { |
63 | struct udf_sb_info *sbi = UDF_SB(sb: inode->i_sb); |
64 | |
65 | size -= sizeof(struct extendedAttrHeaderDesc); |
66 | iinfo->i_lenEAttr += |
67 | sizeof(struct extendedAttrHeaderDesc); |
68 | eahd->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EAHD); |
69 | if (sbi->s_udfrev >= 0x0200) |
70 | eahd->descTag.descVersion = cpu_to_le16(3); |
71 | else |
72 | eahd->descTag.descVersion = cpu_to_le16(2); |
73 | eahd->descTag.tagSerialNum = |
74 | cpu_to_le16(sbi->s_serial_number); |
75 | eahd->descTag.tagLocation = cpu_to_le32( |
76 | iinfo->i_location.logicalBlockNum); |
77 | eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF); |
78 | eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF); |
79 | } |
80 | |
81 | offset = iinfo->i_lenEAttr; |
82 | if (type < 2048) { |
83 | if (le32_to_cpu(eahd->appAttrLocation) < |
84 | iinfo->i_lenEAttr) { |
85 | uint32_t aal = |
86 | le32_to_cpu(eahd->appAttrLocation); |
87 | memmove(&ea[offset - aal + size], |
88 | &ea[aal], offset - aal); |
89 | offset -= aal; |
90 | eahd->appAttrLocation = |
91 | cpu_to_le32(aal + size); |
92 | } |
93 | if (le32_to_cpu(eahd->impAttrLocation) < |
94 | iinfo->i_lenEAttr) { |
95 | uint32_t ial = |
96 | le32_to_cpu(eahd->impAttrLocation); |
97 | memmove(&ea[offset - ial + size], |
98 | &ea[ial], offset - ial); |
99 | offset -= ial; |
100 | eahd->impAttrLocation = |
101 | cpu_to_le32(ial + size); |
102 | } |
103 | } else if (type < 65536) { |
104 | if (le32_to_cpu(eahd->appAttrLocation) < |
105 | iinfo->i_lenEAttr) { |
106 | uint32_t aal = |
107 | le32_to_cpu(eahd->appAttrLocation); |
108 | memmove(&ea[offset - aal + size], |
109 | &ea[aal], offset - aal); |
110 | offset -= aal; |
111 | eahd->appAttrLocation = |
112 | cpu_to_le32(aal + size); |
113 | } |
114 | } |
115 | /* rewrite CRC + checksum of eahd */ |
116 | crclen = sizeof(struct extendedAttrHeaderDesc) - sizeof(struct tag); |
117 | eahd->descTag.descCRCLength = cpu_to_le16(crclen); |
118 | eahd->descTag.descCRC = cpu_to_le16(crc_itu_t(0, (char *)eahd + |
119 | sizeof(struct tag), crclen)); |
120 | eahd->descTag.tagChecksum = udf_tag_checksum(t: &eahd->descTag); |
121 | iinfo->i_lenEAttr += size; |
122 | return (struct genericFormat *)&ea[offset]; |
123 | } |
124 | |
125 | return NULL; |
126 | } |
127 | |
128 | struct genericFormat *udf_get_extendedattr(struct inode *inode, uint32_t type, |
129 | uint8_t subtype) |
130 | { |
131 | struct genericFormat *gaf; |
132 | uint8_t *ea = NULL; |
133 | uint32_t offset; |
134 | struct udf_inode_info *iinfo = UDF_I(inode); |
135 | |
136 | ea = iinfo->i_data; |
137 | |
138 | if (iinfo->i_lenEAttr) { |
139 | struct extendedAttrHeaderDesc *eahd; |
140 | eahd = (struct extendedAttrHeaderDesc *)ea; |
141 | |
142 | /* check checksum/crc */ |
143 | if (eahd->descTag.tagIdent != |
144 | cpu_to_le16(TAG_IDENT_EAHD) || |
145 | le32_to_cpu(eahd->descTag.tagLocation) != |
146 | iinfo->i_location.logicalBlockNum) |
147 | return NULL; |
148 | |
149 | if (type < 2048) |
150 | offset = sizeof(struct extendedAttrHeaderDesc); |
151 | else if (type < 65536) |
152 | offset = le32_to_cpu(eahd->impAttrLocation); |
153 | else |
154 | offset = le32_to_cpu(eahd->appAttrLocation); |
155 | |
156 | while (offset + sizeof(*gaf) < iinfo->i_lenEAttr) { |
157 | uint32_t attrLength; |
158 | |
159 | gaf = (struct genericFormat *)&ea[offset]; |
160 | attrLength = le32_to_cpu(gaf->attrLength); |
161 | |
162 | /* Detect undersized elements and buffer overflows */ |
163 | if ((attrLength < sizeof(*gaf)) || |
164 | (attrLength > (iinfo->i_lenEAttr - offset))) |
165 | break; |
166 | |
167 | if (le32_to_cpu(gaf->attrType) == type && |
168 | gaf->attrSubtype == subtype) |
169 | return gaf; |
170 | else |
171 | offset += attrLength; |
172 | } |
173 | } |
174 | |
175 | return NULL; |
176 | } |
177 | |
178 | /* |
179 | * udf_read_tagged |
180 | * |
181 | * PURPOSE |
182 | * Read the first block of a tagged descriptor. |
183 | * |
184 | * HISTORY |
185 | * July 1, 1997 - Andrew E. Mileski |
186 | * Written, tested, and released. |
187 | */ |
188 | struct buffer_head *udf_read_tagged(struct super_block *sb, uint32_t block, |
189 | uint32_t location, uint16_t *ident) |
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, block=%u, location=%u\n" , |
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->tagLocation)) { |
211 | udf_debug("location mismatch block %u, tag %u != %u\n" , |
212 | block, le32_to_cpu(tag_p->tagLocation), location); |
213 | goto error_out; |
214 | } |
215 | |
216 | /* Verify the tag checksum */ |
217 | checksum = udf_tag_checksum(t: tag_p); |
218 | if (checksum != tag_p->tagChecksum) { |
219 | udf_err(sb, "tag checksum failed, block %u: 0x%02x != 0x%02x\n" , |
220 | block, checksum, tag_p->tagChecksum); |
221 | goto error_out; |
222 | } |
223 | |
224 | /* Verify the tag version */ |
225 | if (tag_p->descVersion != cpu_to_le16(0x0002U) && |
226 | tag_p->descVersion != cpu_to_le16(0x0003U)) { |
227 | udf_err(sb, "tag version 0x%04x != 0x0002 || 0x0003, block %u\n" , |
228 | le16_to_cpu(tag_p->descVersion), block); |
229 | goto error_out; |
230 | } |
231 | |
232 | /* Verify the descriptor CRC */ |
233 | if (le16_to_cpu(tag_p->descCRCLength) + sizeof(struct tag) > sb->s_blocksize || |
234 | le16_to_cpu(tag_p->descCRC) == crc_itu_t(crc: 0, |
235 | buffer: bh->b_data + sizeof(struct tag), |
236 | le16_to_cpu(tag_p->descCRCLength))) |
237 | return bh; |
238 | |
239 | udf_debug("Crc failure block %u: crc = %u, crclen = %u\n" , block, |
240 | le16_to_cpu(tag_p->descCRC), |
241 | le16_to_cpu(tag_p->descCRCLength)); |
242 | error_out: |
243 | brelse(bh); |
244 | return NULL; |
245 | } |
246 | |
247 | struct buffer_head *udf_read_ptagged(struct super_block *sb, |
248 | struct kernel_lb_addr *loc, |
249 | uint32_t offset, uint16_t *ident) |
250 | { |
251 | return udf_read_tagged(sb, block: udf_get_lb_pblock(sb, loc, offset), |
252 | location: loc->logicalBlockNum + offset, ident); |
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(length); |
261 | tptr->descCRC = cpu_to_le16(crc_itu_t(0, data + sizeof(struct tag), length)); |
262 | tptr->tagChecksum = udf_tag_checksum(t: tptr); |
263 | } |
264 | |
265 | void udf_new_tag(char *data, uint16_t ident, uint16_t version, uint16_t snum, |
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(version); |
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); ++i) |
282 | if (i != 4) /* position of checksum */ |
283 | checksum += data[i]; |
284 | return checksum; |
285 | } |
286 | |