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

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    Revision 532 - (hide 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 niro 532 /* 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     }