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

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    Revision 816 - (show annotations) (download)
    Fri Apr 24 18:33:46 2009 UTC (15 years ago) by niro
    File MIME type: text/plain
    File size: 5495 byte(s) 
    -updated to busybox-1.13.4
    1 /* vi: set sw=4 ts=4: */
    2 /* Copyright 2002 Laurence Anderson
    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 typedef struct hardlinks_t {
    11 struct hardlinks_t *next;
    12 int inode; /* TODO: must match maj/min too! */
    13 int mode ;
    14 int mtime; /* These three are useful only in corner case */
    15 int uid ; /* of hardlinks with zero size body */
    16 int gid ;
    17 char name[1];
    18 } hardlinks_t;
    19
    20 char FAST_FUNC get_header_cpio(archive_handle_t *archive_handle)
    21 {
    22 file_header_t *file_header = archive_handle->file_header;
    23 char cpio_header[110];
    24 int namesize;
    25 int major, minor, nlink, mode, inode;
    26 unsigned size, uid, gid, mtime;
    27
    28 #define hardlinks_to_create (*(hardlinks_t **)(&archive_handle->ah_priv[0]))
    29 #define created_hardlinks (*(hardlinks_t **)(&archive_handle->ah_priv[1]))
    30 #define block_count (archive_handle->ah_priv[2])
    31 // if (!archive_handle->ah_priv_inited) {
    32 // archive_handle->ah_priv_inited = 1;
    33 // hardlinks_to_create = NULL;
    34 // created_hardlinks = NULL;
    35 // }
    36
    37 /* There can be padding before archive header */
    38 data_align(archive_handle, 4);
    39
    40 size = full_read(archive_handle->src_fd, cpio_header, 110);
    41 if (size == 0) {
    42 goto create_hardlinks;
    43 }
    44 if (size != 110) {
    45 bb_error_msg_and_die("short read");
    46 }
    47 archive_handle->offset += 110;
    48
    49 if (strncmp(&cpio_header[0], "07070", 5) != 0
    50 || (cpio_header[5] != '1' && cpio_header[5] != '2')
    51 ) {
    52 bb_error_msg_and_die("unsupported cpio format, use newc or crc");
    53 }
    54
    55 if (sscanf(cpio_header + 6,
    56 "%8x" "%8x" "%8x" "%8x"
    57 "%8x" "%8x" "%8x" /*maj,min:*/ "%*16c"
    58 /*rmaj,rmin:*/"%8x" "%8x" "%8x" /*chksum: "%*8c"*/,
    59 &inode, &mode, &uid, &gid,
    60 &nlink, &mtime, &size,
    61 &major, &minor, &namesize) != 10)
    62 bb_error_msg_and_die("damaged cpio file");
    63 file_header->mode = mode;
    64 file_header->uid = uid;
    65 file_header->gid = gid;
    66 file_header->mtime = mtime;
    67 file_header->size = size;
    68
    69 namesize &= 0x1fff; /* paranoia: limit names to 8k chars */
    70 file_header->name = xzalloc(namesize + 1);
    71 /* Read in filename */
    72 xread(archive_handle->src_fd, file_header->name, namesize);
    73 archive_handle->offset += namesize;
    74
    75 /* Update offset amount and skip padding before file contents */
    76 data_align(archive_handle, 4);
    77
    78 if (strcmp(file_header->name, "TRAILER!!!") == 0) {
    79 /* Always round up. ">> 9" divides by 512 */
    80 block_count = (void*)(ptrdiff_t) ((archive_handle->offset + 511) >> 9);
    81 goto create_hardlinks;
    82 }
    83
    84 file_header->link_target = NULL;
    85 if (S_ISLNK(file_header->mode)) {
    86 file_header->size &= 0x1fff; /* paranoia: limit names to 8k chars */
    87 file_header->link_target = xzalloc(file_header->size + 1);
    88 xread(archive_handle->src_fd, file_header->link_target, file_header->size);
    89 archive_handle->offset += file_header->size;
    90 file_header->size = 0; /* Stop possible seeks in future */
    91 }
    92
    93 // TODO: data_extract_all can't deal with hardlinks to non-files...
    94 // when fixed, change S_ISREG to !S_ISDIR here
    95
    96 if (nlink > 1 && S_ISREG(file_header->mode)) {
    97 hardlinks_t *new = xmalloc(sizeof(*new) + namesize);
    98 new->inode = inode;
    99 new->mode = mode ;
    100 new->mtime = mtime;
    101 new->uid = uid ;
    102 new->gid = gid ;
    103 strcpy(new->name, file_header->name);
    104 /* Put file on a linked list for later */
    105 if (size == 0) {
    106 new->next = hardlinks_to_create;
    107 hardlinks_to_create = new;
    108 return EXIT_SUCCESS; /* Skip this one */
    109 /* TODO: this breaks cpio -t (it does not show hardlinks) */
    110 }
    111 new->next = created_hardlinks;
    112 created_hardlinks = new;
    113 }
    114 file_header->device = makedev(major, minor);
    115
    116 if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
    117 archive_handle->action_data(archive_handle);
    118 archive_handle->action_header(file_header);
    119 } else {
    120 data_skip(archive_handle);
    121 }
    122
    123 archive_handle->offset += file_header->size;
    124
    125 free(file_header->link_target);
    126 free(file_header->name);
    127 file_header->link_target = NULL;
    128 file_header->name = NULL;
    129
    130 return EXIT_SUCCESS;
    131
    132 create_hardlinks:
    133 free(file_header->link_target);
    134 free(file_header->name);
    135
    136 while (hardlinks_to_create) {
    137 hardlinks_t *cur;
    138 hardlinks_t *make_me = hardlinks_to_create;
    139
    140 hardlinks_to_create = make_me->next;
    141
    142 memset(file_header, 0, sizeof(*file_header));
    143 file_header->mtime = make_me->mtime;
    144 file_header->name = make_me->name;
    145 file_header->mode = make_me->mode;
    146 file_header->uid = make_me->uid;
    147 file_header->gid = make_me->gid;
    148 /*file_header->size = 0;*/
    149 /*file_header->link_target = NULL;*/
    150
    151 /* Try to find a file we are hardlinked to */
    152 cur = created_hardlinks;
    153 while (cur) {
    154 /* TODO: must match maj/min too! */
    155 if (cur->inode == make_me->inode) {
    156 file_header->link_target = cur->name;
    157 /* link_target != NULL, size = 0: "I am a hardlink" */
    158 if (archive_handle->filter(archive_handle) == EXIT_SUCCESS)
    159 archive_handle->action_data(archive_handle);
    160 free(make_me);
    161 goto next_link;
    162 }
    163 cur = cur->next;
    164 }
    165 /* Oops... no file with such inode was created... do it now
    166 * (happens when hardlinked files are empty (zero length)) */
    167 if (archive_handle->filter(archive_handle) == EXIT_SUCCESS)
    168 archive_handle->action_data(archive_handle);
    169 /* Move to the list of created hardlinked files */
    170 make_me->next = created_hardlinks;
    171 created_hardlinks = make_me;
    172 next_link: ;
    173 }
    174
    175 while (created_hardlinks) {
    176 hardlinks_t *p = created_hardlinks;
    177 created_hardlinks = p->next;
    178 free(p);
    179 }
    180
    181 return EXIT_FAILURE; /* "No more files to process" */
    182 }