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

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    Revision 532 - (show annotations) (download)
    Sat Sep 1 22:45:15 2007 UTC (16 years, 8 months ago) by niro
    File MIME type: text/plain
    File size: 4267 byte(s) 
    -import if magellan mkinitrd; it is a fork of redhats mkinitrd-5.0.8 with all magellan patches and features; deprecates magellan-src/mkinitrd
    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 char get_header_ar(archive_handle_t *archive_handle)
    11 {
    12 int err;
    13 file_header_t *typed = archive_handle->file_header;
    14 union {
    15 char raw[60];
    16 struct {
    17 char name[16];
    18 char date[12];
    19 char uid[6];
    20 char gid[6];
    21 char mode[8];
    22 char size[10];
    23 char magic[2];
    24 } formatted;
    25 } ar;
    26 #ifdef CONFIG_FEATURE_AR_LONG_FILENAMES
    27 static char *ar_long_names;
    28 static unsigned int ar_long_name_size;
    29 #endif
    30
    31 /* dont use xread as we want to handle the error ourself */
    32 if (read(archive_handle->src_fd, ar.raw, 60) != 60) {
    33 /* End Of File */
    34 return EXIT_FAILURE;
    35 }
    36
    37 /* ar header starts on an even byte (2 byte aligned)
    38 * '\n' is used for padding
    39 */
    40 if (ar.raw[0] == '\n') {
    41 /* fix up the header, we started reading 1 byte too early */
    42 memmove(ar.raw, &ar.raw[1], 59);
    43 ar.raw[59] = xread_char(archive_handle->src_fd);
    44 archive_handle->offset++;
    45 }
    46 archive_handle->offset += 60;
    47
    48 /* align the headers based on the header magic */
    49 if (ar.formatted.magic[0] != '`' || ar.formatted.magic[1] != '\n')
    50 bb_error_msg_and_die("invalid ar header");
    51
    52 /* FIXME: more thorough routine would be in order here */
    53 /* (we have something like that in tar) */
    54 /* but for now we are lax. This code works because */
    55 /* on misformatted numbers bb_strtou returns all-ones */
    56 typed->mode = err = bb_strtou(ar.formatted.mode, NULL, 8);
    57 if (err == -1) bb_error_msg_and_die("invalid ar header");
    58 typed->mtime = err = bb_strtou(ar.formatted.date, NULL, 10);
    59 if (err == -1) bb_error_msg_and_die("invalid ar header");
    60 typed->uid = err = bb_strtou(ar.formatted.uid, NULL, 10);
    61 if (err == -1) bb_error_msg_and_die("invalid ar header");
    62 typed->gid = err = bb_strtou(ar.formatted.gid, NULL, 10);
    63 if (err == -1) bb_error_msg_and_die("invalid ar header");
    64 typed->size = err = bb_strtou(ar.formatted.size, NULL, 10);
    65 if (err == -1) bb_error_msg_and_die("invalid ar header");
    66
    67 /* long filenames have '/' as the first character */
    68 if (ar.formatted.name[0] == '/') {
    69 #ifdef CONFIG_FEATURE_AR_LONG_FILENAMES
    70 if (ar.formatted.name[1] == '/') {
    71 /* If the second char is a '/' then this entries data section
    72 * stores long filename for multiple entries, they are stored
    73 * in static variable long_names for use in future entries */
    74 ar_long_name_size = typed->size;
    75 ar_long_names = xmalloc(ar_long_name_size);
    76 xread(archive_handle->src_fd, ar_long_names, ar_long_name_size);
    77 archive_handle->offset += ar_long_name_size;
    78 /* This ar entries data section only contained filenames for other records
    79 * they are stored in the static ar_long_names for future reference */
    80 return get_header_ar(archive_handle); /* Return next header */
    81 } else if (ar.formatted.name[1] == ' ') {
    82 /* This is the index of symbols in the file for compilers */
    83 data_skip(archive_handle);
    84 archive_handle->offset += typed->size;
    85 return get_header_ar(archive_handle); /* Return next header */
    86 } else {
    87 /* The number after the '/' indicates the offset in the ar data section
    88 (saved in variable long_name) that conatains the real filename */
    89 const unsigned int long_offset = atoi(&ar.formatted.name[1]);
    90 if (long_offset >= ar_long_name_size) {
    91 bb_error_msg_and_die("can't resolve long filename");
    92 }
    93 typed->name = xstrdup(ar_long_names + long_offset);
    94 }
    95 #else
    96 bb_error_msg_and_die("long filenames not supported");
    97 #endif
    98 } else {
    99 /* short filenames */
    100 typed->name = xstrndup(ar.formatted.name, 16);
    101 }
    102
    103 typed->name[strcspn(typed->name, " /")] = '\0';
    104
    105 if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
    106 archive_handle->action_header(typed);
    107 if (archive_handle->sub_archive) {
    108 while (archive_handle->action_data_subarchive(archive_handle->sub_archive) == EXIT_SUCCESS)
    109 /* repeat */;
    110 } else {
    111 archive_handle->action_data(archive_handle);
    112 }
    113 } else {
    114 data_skip(archive_handle);
    115 }
    116
    117 archive_handle->offset += typed->size;
    118 /* Set the file pointer to the correct spot, we may have been reading a compressed file */
    119 lseek(archive_handle->src_fd, archive_handle->offset, SEEK_SET);
    120
    121 return EXIT_SUCCESS;
    122 }