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);