source: branches/3.2/mindi-busybox/archival/libarchive/get_header_ar.c @ 3232

Last change on this file since 3232 was 3232, checked in by Bruno Cornec, 6 years ago
  • Update mindi-busybox to 1.21.1
  • Property svn:eol-style set to native
File size: 4.0 KB
Line 
1/* vi: set sw=4 ts=4: */
2/* Copyright 2001 Glenn McGrath.
3 *
4 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
5 */
6
7#include "libbb.h"
8#include "bb_archive.h"
9#include "ar.h"
10
11static unsigned read_num(const char *str, int base)
12{
13    /* This code works because
14     * on misformatted numbers bb_strtou returns all-ones */
15    int err = bb_strtou(str, NULL, base);
16    if (err == -1)
17        bb_error_msg_and_die("invalid ar header");
18    return err;
19}
20
21char FAST_FUNC get_header_ar(archive_handle_t *archive_handle)
22{
23    file_header_t *typed = archive_handle->file_header;
24    unsigned size;
25    union {
26        char raw[60];
27        struct ar_header formatted;
28    } ar;
29#if ENABLE_FEATURE_AR_LONG_FILENAMES
30    static char *ar_long_names;
31    static unsigned ar_long_name_size;
32#endif
33
34    /* dont use xread as we want to handle the error ourself */
35    if (read(archive_handle->src_fd, ar.raw, 60) != 60) {
36        /* End Of File */
37        return EXIT_FAILURE;
38    }
39
40    /* ar header starts on an even byte (2 byte aligned)
41     * '\n' is used for padding
42     */
43    if (ar.raw[0] == '\n') {
44        /* fix up the header, we started reading 1 byte too early */
45        memmove(ar.raw, &ar.raw[1], 59);
46        ar.raw[59] = xread_char(archive_handle->src_fd);
47        archive_handle->offset++;
48    }
49    archive_handle->offset += 60;
50
51    if (ar.formatted.magic[0] != '`' || ar.formatted.magic[1] != '\n')
52        bb_error_msg_and_die("invalid ar header");
53
54    /* FIXME: more thorough routine would be in order here
55     * (we have something like that in tar)
56     * but for now we are lax. */
57    ar.formatted.magic[0] = '\0'; /* else 4G-2 file will have size="4294967294`\n..." */
58    typed->size = size = read_num(ar.formatted.size, 10);
59
60    /* special filenames have '/' as the first character */
61    if (ar.formatted.name[0] == '/') {
62        if (ar.formatted.name[1] == ' ') {
63            /* This is the index of symbols in the file for compilers */
64            data_skip(archive_handle);
65            archive_handle->offset += size;
66            return get_header_ar(archive_handle); /* Return next header */
67        }
68#if ENABLE_FEATURE_AR_LONG_FILENAMES
69        if (ar.formatted.name[1] == '/') {
70            /* If the second char is a '/' then this entries data section
71             * stores long filename for multiple entries, they are stored
72             * in static variable long_names for use in future entries
73             */
74            ar_long_name_size = size;
75            free(ar_long_names);
76            ar_long_names = xmalloc(size);
77            xread(archive_handle->src_fd, ar_long_names, size);
78            archive_handle->offset += size;
79            /* Return next header */
80            return get_header_ar(archive_handle);
81        }
82#else
83        bb_error_msg_and_die("long filenames not supported");
84#endif
85    }
86    /* Only size is always present, the rest may be missing in
87     * long filename pseudo file. Thus we decode the rest
88     * after dealing with long filename pseudo file.
89     */
90    typed->mode = read_num(ar.formatted.mode, 8);
91    typed->mtime = read_num(ar.formatted.date, 10);
92    typed->uid = read_num(ar.formatted.uid, 10);
93    typed->gid = read_num(ar.formatted.gid, 10);
94
95#if ENABLE_FEATURE_AR_LONG_FILENAMES
96    if (ar.formatted.name[0] == '/') {
97        unsigned long_offset;
98
99        /* The number after the '/' indicates the offset in the ar data section
100         * (saved in ar_long_names) that conatains the real filename */
101        long_offset = read_num(&ar.formatted.name[1], 10);
102        if (long_offset >= ar_long_name_size) {
103            bb_error_msg_and_die("can't resolve long filename");
104        }
105        typed->name = xstrdup(ar_long_names + long_offset);
106    } else
107#endif
108    {
109        /* short filenames */
110        typed->name = xstrndup(ar.formatted.name, 16);
111    }
112
113    typed->name[strcspn(typed->name, " /")] = '\0';
114
115    if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
116        archive_handle->action_header(typed);
117#if ENABLE_DPKG || ENABLE_DPKG_DEB
118        if (archive_handle->dpkg__sub_archive) {
119            while (archive_handle->dpkg__action_data_subarchive(archive_handle->dpkg__sub_archive) == EXIT_SUCCESS)
120                continue;
121        } else
122#endif
123            archive_handle->action_data(archive_handle);
124    } else {
125        data_skip(archive_handle);
126    }
127
128    archive_handle->offset += typed->size;
129    /* Set the file pointer to the correct spot, we may have been reading a compressed file */
130    lseek(archive_handle->src_fd, archive_handle->offset, SEEK_SET);
131
132    return EXIT_SUCCESS;
133}
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