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    Contents of /trunk/mkinitrd-magellan/busybox/archival/libunarchive/get_header_ar.c

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    Revision 984 - (show annotations) (download)
    Sun May 30 11:32:42 2010 UTC (13 years, 11 months ago) by niro
    File MIME type: text/plain
    File size: 4213 byte(s) 
    -updated to busybox-1.16.1 and enabled blkid/uuid support in default config
    1 /* vi: set sw=4 ts=4: */
    2 /* Copyright 2001 Glenn McGrath.
    3 *
    4 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
    5 */
    6
    7 #include "libbb.h"
    8 #include "unarchive.h"
    9
    10 static unsigned read_num(const char *str, int base)
    11 {
    12 /* This code works because
    13 * on misformatted numbers bb_strtou returns all-ones */
    14 int err = bb_strtou(str, NULL, base);
    15 if (err == -1)
    16 bb_error_msg_and_die("invalid ar header");
    17 return err;
    18 }
    19
    20 char FAST_FUNC get_header_ar(archive_handle_t *archive_handle)
    21 {
    22 file_header_t *typed = archive_handle->file_header;
    23 unsigned size;
    24 union {
    25 char raw[60];
    26 struct {
    27 char name[16];
    28 char date[12];
    29 char uid[6];
    30 char gid[6];
    31 char mode[8];
    32 char size[10];
    33 char magic[2];
    34 } formatted;
    35 } ar;
    36 #if ENABLE_FEATURE_AR_LONG_FILENAMES
    37 static char *ar_long_names;
    38 static unsigned ar_long_name_size;
    39 #endif
    40
    41 /* dont use xread as we want to handle the error ourself */
    42 if (read(archive_handle->src_fd, ar.raw, 60) != 60) {
    43 /* End Of File */
    44 return EXIT_FAILURE;
    45 }
    46
    47 /* ar header starts on an even byte (2 byte aligned)
    48 * '\n' is used for padding
    49 */
    50 if (ar.raw[0] == '\n') {
    51 /* fix up the header, we started reading 1 byte too early */
    52 memmove(ar.raw, &ar.raw[1], 59);
    53 ar.raw[59] = xread_char(archive_handle->src_fd);
    54 archive_handle->offset++;
    55 }
    56 archive_handle->offset += 60;
    57
    58 /* align the headers based on the header magic */
    59 if (ar.formatted.magic[0] != '`' || ar.formatted.magic[1] != '\n')
    60 bb_error_msg_and_die("invalid ar header");
    61
    62 /* FIXME: more thorough routine would be in order here
    63 * (we have something like that in tar)
    64 * but for now we are lax. */
    65 typed->size = size = read_num(ar.formatted.size, 10);
    66
    67 /* special filenames have '/' as the first character */
    68 if (ar.formatted.name[0] == '/') {
    69 if (ar.formatted.name[1] == ' ') {
    70 /* This is the index of symbols in the file for compilers */
    71 data_skip(archive_handle);
    72 archive_handle->offset += size;
    73 return get_header_ar(archive_handle); /* Return next header */
    74 }
    75 #if ENABLE_FEATURE_AR_LONG_FILENAMES
    76 if (ar.formatted.name[1] == '/') {
    77 /* If the second char is a '/' then this entries data section
    78 * stores long filename for multiple entries, they are stored
    79 * in static variable long_names for use in future entries
    80 */
    81 ar_long_name_size = size;
    82 free(ar_long_names);
    83 ar_long_names = xmalloc(size);
    84 xread(archive_handle->src_fd, ar_long_names, size);
    85 archive_handle->offset += size;
    86 /* Return next header */
    87 return get_header_ar(archive_handle);
    88 }
    89 #else
    90 bb_error_msg_and_die("long filenames not supported");
    91 #endif
    92 }
    93 /* Only size is always present, the rest may be missing in
    94 * long filename pseudo file. Thus we decode the rest
    95 * after dealing with long filename pseudo file.
    96 */
    97 typed->mode = read_num(ar.formatted.mode, 8);
    98 typed->mtime = read_num(ar.formatted.date, 10);
    99 typed->uid = read_num(ar.formatted.uid, 10);
    100 typed->gid = read_num(ar.formatted.gid, 10);
    101
    102 #if ENABLE_FEATURE_AR_LONG_FILENAMES
    103 if (ar.formatted.name[0] == '/') {
    104 unsigned long_offset;
    105
    106 /* The number after the '/' indicates the offset in the ar data section
    107 * (saved in ar_long_names) that conatains the real filename */
    108 long_offset = read_num(&ar.formatted.name[1], 10);
    109 if (long_offset >= ar_long_name_size) {
    110 bb_error_msg_and_die("can't resolve long filename");
    111 }
    112 typed->name = xstrdup(ar_long_names + long_offset);
    113 } else
    114 #endif
    115 {
    116 /* short filenames */
    117 typed->name = xstrndup(ar.formatted.name, 16);
    118 }
    119
    120 typed->name[strcspn(typed->name, " /")] = '\0';
    121
    122 if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
    123 archive_handle->action_header(typed);
    124 #if ENABLE_DPKG || ENABLE_DPKG_DEB
    125 if (archive_handle->dpkg__sub_archive) {
    126 while (archive_handle->dpkg__action_data_subarchive(archive_handle->dpkg__sub_archive) == EXIT_SUCCESS)
    127 continue;
    128 } else
    129 #endif
    130 archive_handle->action_data(archive_handle);
    131 } else {
    132 data_skip(archive_handle);
    133 }
    134
    135 archive_handle->offset += typed->size;
    136 /* Set the file pointer to the correct spot, we may have been reading a compressed file */
    137 lseek(archive_handle->src_fd, archive_handle->offset, SEEK_SET);
    138
    139 return EXIT_SUCCESS;
    140 }