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
203
204
205
206
207
208
209
210
211
212
213
214
215
|
/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
* write_header.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#include "config.h"
#include "internal.h"
static void write_binary(char *dst, sqfs_u64 value, int digits)
{
memset(dst, 0, digits);
while (digits > 0) {
((unsigned char *)dst)[digits - 1] = value & 0xFF;
--digits;
value >>= 8;
}
((unsigned char *)dst)[0] |= 0x80;
}
static void write_number(char *dst, sqfs_u64 value, int digits)
{
sqfs_u64 mask = 0;
char buffer[64];
int i;
for (i = 0; i < (digits - 1); ++i)
mask = (mask << 3) | 7;
if (value <= mask) {
sprintf(buffer, "%0*o ", digits - 1, (unsigned int)value);
memcpy(dst, buffer, digits);
} else if (value <= ((mask << 3) | 7)) {
sprintf(buffer, "%0*o", digits, (unsigned int)value);
memcpy(dst, buffer, digits);
} else {
write_binary(dst, value, digits);
}
}
static void write_number_signed(char *dst, sqfs_s64 value, int digits)
{
sqfs_u64 neg;
if (value < 0) {
neg = -value;
write_binary(dst, ~neg + 1, digits);
} else {
write_number(dst, value, digits);
}
}
static int write_header(FILE *fp, const struct stat *sb, const char *name,
const char *slink_target, int type)
{
int maj = 0, min = 0;
sqfs_u64 size = 0;
tar_header_t hdr;
if (S_ISCHR(sb->st_mode) || S_ISBLK(sb->st_mode)) {
maj = major(sb->st_rdev);
min = minor(sb->st_rdev);
}
if (S_ISREG(sb->st_mode))
size = sb->st_size;
memset(&hdr, 0, sizeof(hdr));
strncpy(hdr.name, name, sizeof(hdr.name) - 1);
write_number(hdr.mode, sb->st_mode & ~S_IFMT, sizeof(hdr.mode));
write_number(hdr.uid, sb->st_uid, sizeof(hdr.uid));
write_number(hdr.gid, sb->st_gid, sizeof(hdr.gid));
write_number(hdr.size, size, sizeof(hdr.size));
write_number_signed(hdr.mtime, sb->st_mtime, sizeof(hdr.mtime));
hdr.typeflag = type;
if (slink_target != NULL)
memcpy(hdr.linkname, slink_target, sb->st_size);
memcpy(hdr.magic, TAR_MAGIC_OLD, sizeof(hdr.magic));
memcpy(hdr.version, TAR_VERSION_OLD, sizeof(hdr.version));
sprintf(hdr.uname, "%u", sb->st_uid);
sprintf(hdr.gname, "%u", sb->st_gid);
write_number(hdr.devmajor, maj, sizeof(hdr.devmajor));
write_number(hdr.devminor, min, sizeof(hdr.devminor));
update_checksum(&hdr);
return write_retry("writing tar header record", fp, &hdr, sizeof(hdr));
}
static int write_gnu_header(FILE *fp, const struct stat *orig,
const char *payload, size_t payload_len,
int type, const char *name)
{
struct stat sb;
sb = *orig;
sb.st_mode = S_IFREG | 0644;
sb.st_size = payload_len;
if (write_header(fp, &sb, name, NULL, type))
return -1;
if (write_retry("writing GNU extension header",
fp, payload, payload_len)) {
return -1;
}
return padd_file(fp, payload_len);
}
static size_t num_digits(size_t num)
{
size_t i = 1;
while (num > 10) {
num /= 10;
++i;
}
return i;
}
static int write_schily_xattr(FILE *fp, const struct stat *orig,
const char *name, const tar_xattr_t *xattr)
{
static const char *prefix = "SCHILY.xattr.";
size_t len, total_size = 0;
const tar_xattr_t *it;
struct stat sb;
for (it = xattr; it != NULL; it = it->next) {
len = strlen(prefix) + strlen(it->key) + strlen(it->value) + 2;
total_size += num_digits(len) + 1 + len;
}
sb = *orig;
sb.st_mode = S_IFREG | 0644;
sb.st_size = total_size;
if (write_header(fp, &sb, name, NULL, TAR_TYPE_PAX))
return -1;
for (it = xattr; it != NULL; it = it->next) {
len = strlen(prefix) + strlen(it->key) + strlen(it->value) + 2;
len += num_digits(len) + 1;
fprintf(fp, "%zu %s%s=%s\n", len, prefix, it->key, it->value);
}
return padd_file(fp, total_size);
}
int write_tar_header(FILE *fp, const struct stat *sb, const char *name,
const char *slink_target, const tar_xattr_t *xattr,
unsigned int counter)
{
const char *reason;
char buffer[64];
int type;
if (xattr != NULL) {
sprintf(buffer, "pax/xattr%u", counter);
if (write_schily_xattr(fp, sb, buffer, xattr))
return -1;
}
if (!S_ISLNK(sb->st_mode))
slink_target = NULL;
if (S_ISLNK(sb->st_mode) && sb->st_size >= 100) {
sprintf(buffer, "gnu/target%u", counter);
if (write_gnu_header(fp, sb, slink_target, sb->st_size,
TAR_TYPE_GNU_SLINK, buffer))
return -1;
slink_target = NULL;
}
if (strlen(name) >= 100) {
sprintf(buffer, "gnu/name%u", counter);
if (write_gnu_header(fp, sb, name, strlen(name),
TAR_TYPE_GNU_PATH, buffer)) {
return -1;
}
sprintf(buffer, "gnu/data%u", counter);
name = buffer;
}
switch (sb->st_mode & S_IFMT) {
case S_IFCHR: type = TAR_TYPE_CHARDEV; break;
case S_IFBLK: type = TAR_TYPE_BLOCKDEV; break;
case S_IFLNK: type = TAR_TYPE_SLINK; break;
case S_IFREG: type = TAR_TYPE_FILE; break;
case S_IFDIR: type = TAR_TYPE_DIR; break;
case S_IFIFO: type = TAR_TYPE_FIFO; break;
case S_IFSOCK:
reason = "cannot pack socket";
goto out_skip;
default:
reason = "unknown type";
goto out_skip;
}
return write_header(fp, sb, name, slink_target, type);
out_skip:
fprintf(stderr, "WARNING: %s: %s\n", name, reason);
return 1;
}
|
