1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
|
/* SPDX-License-Identifier: GPL-3.0-or-later */
#include "meta_writer.h"
#include "mkfs.h"
#include "util.h"
#include <assert.h>
static const struct {
const char *prefix;
E_SQFS_XATTR_TYPE type;
} xattr_types[] = {
{ "user.", SQUASHFS_XATTR_USER },
{ "trusted.", SQUASHFS_XATTR_TRUSTED },
{ "security.", SQUASHFS_XATTR_SECURITY },
};
static int get_prefix(const char *key)
{
size_t i, len;
for (i = 0; i < sizeof(xattr_types) / sizeof(xattr_types[0]); ++i) {
len = strlen(xattr_types[i].prefix);
if (strncmp(key, xattr_types[i].prefix, len) == 0 &&
strlen(key) > len) {
return xattr_types[i].type;
}
}
fprintf(stderr, "unknown xattr key '%s'\n", key);
return -1;
}
static int write_pair(meta_writer_t *mw, const char *key, const char *value)
{
sqfs_xattr_entry_t kent;
sqfs_xattr_value_t vent;
int type;
type = get_prefix(key);
if (type < 0)
return -1;
key = strchr(key, '.');
assert(key != NULL);
++key;
kent.type = htole16(type);
kent.size = htole16(strlen(key));
if (meta_writer_append(mw, &kent, sizeof(kent)))
return -1;
if (meta_writer_append(mw, key, strlen(key)))
return -1;
vent.size = htole32(strlen(value));
if (meta_writer_append(mw, &vent, sizeof(vent)))
return -1;
if (meta_writer_append(mw, value, strlen(value)))
return -1;
return 0;
}
static int write_kv_pairs(fstree_t *fs, meta_writer_t *mw, tree_xattr_t *xattr)
{
uint32_t key_idx, val_idx;
const char *key, *value;
size_t i;
for (i = 0; i < xattr->num_attr; ++i) {
key_idx = (xattr->ref[i] >> 32) & 0xFFFFFFFF;
val_idx = xattr->ref[i] & 0xFFFFFFFF;
key = str_table_get_string(&fs->xattr_keys, key_idx);
value = str_table_get_string(&fs->xattr_values, val_idx);
if (write_pair(mw, key, value))
return -1;
xattr->size += sizeof(sqfs_xattr_entry_t) + strlen(key);
xattr->size += sizeof(sqfs_xattr_value_t) + strlen(value);
}
return 0;
}
int write_xattr(int outfd, fstree_t *fs, sqfs_super_t *super,
compressor_t *cmp)
{
uint64_t kv_start, id_start, block, *tbl;
size_t i = 0, count = 0, blocks;
sqfs_xattr_id_table_t idtbl;
sqfs_xattr_id_t id_ent;
meta_writer_t *mw;
tree_xattr_t *it;
uint32_t offset;
ssize_t ret;
if (fs->xattr == NULL)
return 0;
mw = meta_writer_create(outfd, cmp);
if (mw == NULL)
return -1;
/* write xattr key-value pairs */
kv_start = super->bytes_used;
for (it = fs->xattr; it != NULL; it = it->next) {
meta_writer_get_position(mw, &it->block, &it->offset);
it->size = 0;
if (write_kv_pairs(fs, mw, it))
goto fail_mw;
++count;
}
if (meta_writer_flush(mw))
goto fail_mw;
meta_writer_get_position(mw, &block, &offset);
meta_writer_reset(mw);
super->bytes_used += block;
/* allocate location table */
blocks = (count * sizeof(id_ent)) / SQFS_META_BLOCK_SIZE;
if ((count * sizeof(id_ent)) % SQFS_META_BLOCK_SIZE)
++blocks;
tbl = calloc(sizeof(uint64_t), blocks);
if (tbl == NULL) {
perror("generating xattr ID table");
goto fail_mw;
}
/* write ID table referring to key value pairs, record offsets */
id_start = 0;
tbl[i++] = htole64(super->bytes_used);
for (it = fs->xattr; it != NULL; it = it->next) {
id_ent.xattr = htole64((it->block << 16) | it->offset);
id_ent.count = htole32(it->num_attr);
id_ent.size = htole32(it->size);
if (meta_writer_append(mw, &id_ent, sizeof(id_ent)))
goto fail_tbl;
meta_writer_get_position(mw, &block, &offset);
if (block != id_start) {
id_start = block;
tbl[i++] = htole64(super->bytes_used + id_start);
}
}
if (meta_writer_flush(mw))
goto fail_tbl;
meta_writer_get_position(mw, &block, &offset);
super->bytes_used += block;
/* write offset table */
idtbl.xattr_table_start = htole64(kv_start);
idtbl.xattr_ids = htole32(count);
idtbl.unused = 0;
ret = write_retry(outfd, &idtbl, sizeof(idtbl));
if (ret < 0)
goto fail_wr;
if ((size_t)ret < sizeof(idtbl))
goto fail_trunc;
write_retry(outfd, tbl, sizeof(tbl[0]) * blocks);
if (ret < 0)
goto fail_wr;
if ((size_t)ret < sizeof(tbl[0]) * blocks)
goto fail_trunc;
super->xattr_id_table_start = super->bytes_used;
super->bytes_used += sizeof(idtbl) + sizeof(tbl[0]) * blocks;
free(tbl);
meta_writer_destroy(mw);
return 0;
fail_wr:
perror("writing xattr ID table");
goto fail_tbl;
fail_trunc:
fputs("writing xattr ID table: truncated write\n", stderr);
goto fail_tbl;
fail_tbl:
free(tbl);
fail_mw:
meta_writer_destroy(mw);
return -1;
}
|
