1 /* vi: set sw=4 ts=4: */
2 /* Copyright 2001 Glenn McGrath.
4 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
8 #include "bb_archive.h"
11 /* WARNING: Clobbers str[len], so fields must be read in reverse order! */
12 static unsigned read_num(char *str
, int base
, int len
)
16 /* ar fields are fixed length text strings (padded with spaces).
17 * Ensure bb_strtou doesn't read past the field in case the full
21 /* This code works because
22 * on misformatted numbers bb_strtou returns all-ones */
23 err
= bb_strtou(str
, NULL
, base
);
25 bb_error_msg_and_die("invalid ar header");
29 char FAST_FUNC
get_header_ar(archive_handle_t
*archive_handle
)
31 file_header_t
*typed
= archive_handle
->file_header
;
35 struct ar_header formatted
;
37 #if ENABLE_FEATURE_AR_LONG_FILENAMES
38 static char *ar_long_names
;
39 static unsigned ar_long_name_size
;
42 /* dont use xread as we want to handle the error ourself */
43 if (read(archive_handle
->src_fd
, ar
.raw
, 60) != 60) {
48 /* ar header starts on an even byte (2 byte aligned)
49 * '\n' is used for padding
51 if (ar
.raw
[0] == '\n') {
52 /* fix up the header, we started reading 1 byte too early */
53 memmove(ar
.raw
, &ar
.raw
[1], 59);
54 ar
.raw
[59] = xread_char(archive_handle
->src_fd
);
55 archive_handle
->offset
++;
57 archive_handle
->offset
+= 60;
59 if (ar
.formatted
.magic
[0] != '`' || ar
.formatted
.magic
[1] != '\n')
60 bb_error_msg_and_die("invalid ar header");
63 * Note that the fields MUST be read in reverse order as
64 * read_num() clobbers the next byte after the field!
65 * Order is: name, date, uid, gid, mode, size, magic.
67 typed
->size
= size
= read_num(ar
.formatted
.size
, 10,
68 sizeof(ar
.formatted
.size
));
70 /* special filenames have '/' as the first character */
71 if (ar
.formatted
.name
[0] == '/') {
72 if (ar
.formatted
.name
[1] == ' ') {
73 /* This is the index of symbols in the file for compilers */
74 data_skip(archive_handle
);
75 archive_handle
->offset
+= size
;
76 return get_header_ar(archive_handle
); /* Return next header */
78 #if ENABLE_FEATURE_AR_LONG_FILENAMES
79 if (ar
.formatted
.name
[1] == '/') {
80 /* If the second char is a '/' then this entries data section
81 * stores long filename for multiple entries, they are stored
82 * in static variable long_names for use in future entries
84 ar_long_name_size
= size
;
86 ar_long_names
= xmalloc(size
);
87 xread(archive_handle
->src_fd
, ar_long_names
, size
);
88 archive_handle
->offset
+= size
;
89 /* Return next header */
90 return get_header_ar(archive_handle
);
93 bb_error_msg_and_die("long filenames not supported");
96 /* Only size is always present, the rest may be missing in
97 * long filename pseudo file. Thus we decode the rest
98 * after dealing with long filename pseudo file.
100 typed
->mode
= read_num(ar
.formatted
.mode
, 8, sizeof(ar
.formatted
.mode
));
101 typed
->gid
= read_num(ar
.formatted
.gid
, 10, sizeof(ar
.formatted
.gid
));
102 typed
->uid
= read_num(ar
.formatted
.uid
, 10, sizeof(ar
.formatted
.uid
));
103 typed
->mtime
= read_num(ar
.formatted
.date
, 10, sizeof(ar
.formatted
.date
));
105 #if ENABLE_FEATURE_AR_LONG_FILENAMES
106 if (ar
.formatted
.name
[0] == '/') {
107 unsigned long_offset
;
109 /* The number after the '/' indicates the offset in the ar data section
110 * (saved in ar_long_names) that conatains the real filename */
111 long_offset
= read_num(&ar
.formatted
.name
[1], 10,
112 sizeof(ar
.formatted
.name
) - 1);
113 if (long_offset
>= ar_long_name_size
) {
114 bb_error_msg_and_die("can't resolve long filename");
116 typed
->name
= xstrdup(ar_long_names
+ long_offset
);
120 /* short filenames */
121 typed
->name
= xstrndup(ar
.formatted
.name
, 16);
124 typed
->name
[strcspn(typed
->name
, " /")] = '\0';
126 if (archive_handle
->filter(archive_handle
) == EXIT_SUCCESS
) {
127 archive_handle
->action_header(typed
);
128 #if ENABLE_DPKG || ENABLE_DPKG_DEB
129 if (archive_handle
->dpkg__sub_archive
) {
130 while (archive_handle
->dpkg__action_data_subarchive(archive_handle
->dpkg__sub_archive
) == EXIT_SUCCESS
)
134 archive_handle
->action_data(archive_handle
);
136 data_skip(archive_handle
);
139 archive_handle
->offset
+= typed
->size
;
140 /* Set the file pointer to the correct spot, we may have been reading a compressed file */
141 lseek(archive_handle
->src_fd
, archive_handle
->offset
, SEEK_SET
);