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
|
/* vi: set sw=4 ts=4: */
/* Copyright 2001 Glenn McGrath.
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
#include "bb_archive.h"
#include "ar.h"
/* WARNING: Clobbers str[len], so fields must be read in reverse order! */
static unsigned read_num(char *str, int base, int len)
{
int err;
/* ar fields are fixed length text strings (padded with spaces).
* Ensure bb_strtou doesn't read past the field in case the full
* width is used. */
str[len] = 0;
/* This code works because
* on misformatted numbers bb_strtou returns all-ones */
err = bb_strtou(str, NULL, base);
if (err == -1)
bb_error_msg_and_die("invalid ar header");
return err;
}
char FAST_FUNC get_header_ar(archive_handle_t *archive_handle)
{
file_header_t *typed = archive_handle->file_header;
unsigned size;
union {
char raw[60];
struct ar_header formatted;
} ar;
#if ENABLE_FEATURE_AR_LONG_FILENAMES
static char *ar_long_names;
static unsigned ar_long_name_size;
#endif
/* dont use xread as we want to handle the error ourself */
if (read(archive_handle->src_fd, ar.raw, 60) != 60) {
/* End Of File */
return EXIT_FAILURE;
}
/* ar header starts on an even byte (2 byte aligned)
* '\n' is used for padding
*/
if (ar.raw[0] == '\n') {
/* fix up the header, we started reading 1 byte too early */
memmove(ar.raw, &ar.raw[1], 59);
ar.raw[59] = xread_char(archive_handle->src_fd);
archive_handle->offset++;
}
archive_handle->offset += 60;
if (ar.formatted.magic[0] != '`' || ar.formatted.magic[1] != '\n')
bb_error_msg_and_die("invalid ar header");
typed->size = size = read_num(ar.formatted.size, 10,
sizeof(ar.formatted.size));
/* special filenames have '/' as the first character */
if (ar.formatted.name[0] == '/') {
if (ar.formatted.name[1] == ' ') {
/* This is the index of symbols in the file for compilers */
data_skip(archive_handle);
archive_handle->offset += size;
return get_header_ar(archive_handle); /* Return next header */
}
#if ENABLE_FEATURE_AR_LONG_FILENAMES
if (ar.formatted.name[1] == '/') {
/* If the second char is a '/' then this entries data section
* stores long filename for multiple entries, they are stored
* in static variable long_names for use in future entries
*/
ar_long_name_size = size;
free(ar_long_names);
ar_long_names = xmalloc(size);
xread(archive_handle->src_fd, ar_long_names, size);
archive_handle->offset += size;
/* Return next header */
return get_header_ar(archive_handle);
}
#else
bb_error_msg_and_die("long filenames not supported");
#endif
}
/* Only size is always present, the rest may be missing in
* long filename pseudo file. Thus we decode the rest
* after dealing with long filename pseudo file.
* Note that the fields MUST be read in reverse order as
* read_num() clobbers the next byte after the field!
*/
typed->mode = read_num(ar.formatted.mode, 8, sizeof(ar.formatted.mode));
typed->gid = read_num(ar.formatted.gid, 10, sizeof(ar.formatted.gid));
typed->uid = read_num(ar.formatted.uid, 10, sizeof(ar.formatted.uid));
typed->mtime = read_num(ar.formatted.date, 10, sizeof(ar.formatted.date));
#if ENABLE_FEATURE_AR_LONG_FILENAMES
if (ar.formatted.name[0] == '/') {
unsigned long_offset;
/* The number after the '/' indicates the offset in the ar data section
* (saved in ar_long_names) that conatains the real filename */
long_offset = read_num(&ar.formatted.name[1], 10,
sizeof(ar.formatted.name) - 1);
if (long_offset >= ar_long_name_size) {
bb_error_msg_and_die("can't resolve long filename");
}
typed->name = xstrdup(ar_long_names + long_offset);
} else
#endif
{
/* short filenames */
typed->name = xstrndup(ar.formatted.name, 16);
}
typed->name[strcspn(typed->name, " /")] = '\0';
if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
archive_handle->action_header(typed);
#if ENABLE_DPKG || ENABLE_DPKG_DEB
if (archive_handle->dpkg__sub_archive) {
while (archive_handle->dpkg__action_data_subarchive(archive_handle->dpkg__sub_archive) == EXIT_SUCCESS)
continue;
} else
#endif
archive_handle->action_data(archive_handle);
} else {
data_skip(archive_handle);
}
archive_handle->offset += typed->size;
/* Set the file pointer to the correct spot, we may have been reading a compressed file */
lseek(archive_handle->src_fd, archive_handle->offset, SEEK_SET);
return EXIT_SUCCESS;
}
|
