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

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    Revision 984 - (hide annotations) (download)
    Sun May 30 11:32:42 2010 UTC (13 years, 11 months ago) by niro
    File MIME type: text/plain
    File size: 5915 byte(s) 
    -updated to busybox-1.16.1 and enabled blkid/uuid support in default config
    1 niro 532 /* 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 niro 816 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 niro 532 } hardlinks_t;
    19    
    20 niro 816 char FAST_FUNC get_header_cpio(archive_handle_t *archive_handle)
    21 niro 532 {
    22     file_header_t *file_header = archive_handle->file_header;
    23     char cpio_header[110];
    24     int namesize;
    25 niro 816 int major, minor, nlink, mode, inode;
    26     unsigned size, uid, gid, mtime;
    27 niro 532
    28     /* There can be padding before archive header */
    29     data_align(archive_handle, 4);
    30    
    31 niro 816 size = full_read(archive_handle->src_fd, cpio_header, 110);
    32     if (size == 0) {
    33     goto create_hardlinks;
    34 niro 532 }
    35 niro 816 if (size != 110) {
    36     bb_error_msg_and_die("short read");
    37     }
    38 niro 532 archive_handle->offset += 110;
    39    
    40     if (strncmp(&cpio_header[0], "07070", 5) != 0
    41     || (cpio_header[5] != '1' && cpio_header[5] != '2')
    42     ) {
    43     bb_error_msg_and_die("unsupported cpio format, use newc or crc");
    44     }
    45    
    46 niro 816 if (sscanf(cpio_header + 6,
    47     "%8x" "%8x" "%8x" "%8x"
    48     "%8x" "%8x" "%8x" /*maj,min:*/ "%*16c"
    49     /*rmaj,rmin:*/"%8x" "%8x" "%8x" /*chksum: "%*8c"*/,
    50     &inode, &mode, &uid, &gid,
    51     &nlink, &mtime, &size,
    52     &major, &minor, &namesize) != 10)
    53     bb_error_msg_and_die("damaged cpio file");
    54     file_header->mode = mode;
    55     file_header->uid = uid;
    56     file_header->gid = gid;
    57     file_header->mtime = mtime;
    58     file_header->size = size;
    59 niro 532
    60 niro 816 namesize &= 0x1fff; /* paranoia: limit names to 8k chars */
    61 niro 532 file_header->name = xzalloc(namesize + 1);
    62     /* Read in filename */
    63     xread(archive_handle->src_fd, file_header->name, namesize);
    64 niro 984 if (file_header->name[0] == '/') {
    65     /* Testcase: echo /etc/hosts | cpio -pvd /tmp
    66     * Without this code, it tries to unpack /etc/hosts
    67     * into "/etc/hosts", not "etc/hosts".
    68     */
    69     char *p = file_header->name;
    70     do p++; while (*p == '/');
    71     overlapping_strcpy(file_header->name, p);
    72     }
    73 niro 532 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 niro 816 /* Always round up. ">> 9" divides by 512 */
    80 niro 984 archive_handle->cpio__blocks = (uoff_t)(archive_handle->offset + 511) >> 9;
    81 niro 816 goto create_hardlinks;
    82 niro 532 }
    83    
    84 niro 816 file_header->link_target = NULL;
    85 niro 532 if (S_ISLNK(file_header->mode)) {
    86 niro 816 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 niro 532 archive_handle->offset += file_header->size;
    90     file_header->size = 0; /* Stop possible seeks in future */
    91     }
    92 niro 816
    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 niro 984 new->next = archive_handle->cpio__hardlinks_to_create;
    107     archive_handle->cpio__hardlinks_to_create = new;
    108 niro 532 return EXIT_SUCCESS; /* Skip this one */
    109 niro 816 /* TODO: this breaks cpio -t (it does not show hardlinks) */
    110 niro 532 }
    111 niro 984 new->next = archive_handle->cpio__created_hardlinks;
    112     archive_handle->cpio__created_hardlinks = new;
    113 niro 532 }
    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 niro 984 //TODO: run "echo /etc/hosts | cpio -pv /tmp" twice. On 2nd run:
    119     //cpio: etc/hosts not created: newer or same age file exists
    120     //etc/hosts <-- should NOT show it
    121     //2 blocks <-- should say "0 blocks"
    122 niro 816 archive_handle->action_header(file_header);
    123 niro 532 } else {
    124     data_skip(archive_handle);
    125     }
    126    
    127     archive_handle->offset += file_header->size;
    128    
    129 niro 816 free(file_header->link_target);
    130     free(file_header->name);
    131     file_header->link_target = NULL;
    132     file_header->name = NULL;
    133 niro 532
    134     return EXIT_SUCCESS;
    135 niro 816
    136     create_hardlinks:
    137     free(file_header->link_target);
    138     free(file_header->name);
    139    
    140 niro 984 while (archive_handle->cpio__hardlinks_to_create) {
    141 niro 816 hardlinks_t *cur;
    142 niro 984 hardlinks_t *make_me = archive_handle->cpio__hardlinks_to_create;
    143 niro 816
    144 niro 984 archive_handle->cpio__hardlinks_to_create = make_me->next;
    145 niro 816
    146     memset(file_header, 0, sizeof(*file_header));
    147     file_header->mtime = make_me->mtime;
    148     file_header->name = make_me->name;
    149     file_header->mode = make_me->mode;
    150     file_header->uid = make_me->uid;
    151     file_header->gid = make_me->gid;
    152     /*file_header->size = 0;*/
    153     /*file_header->link_target = NULL;*/
    154    
    155     /* Try to find a file we are hardlinked to */
    156 niro 984 cur = archive_handle->cpio__created_hardlinks;
    157 niro 816 while (cur) {
    158     /* TODO: must match maj/min too! */
    159     if (cur->inode == make_me->inode) {
    160     file_header->link_target = cur->name;
    161     /* link_target != NULL, size = 0: "I am a hardlink" */
    162     if (archive_handle->filter(archive_handle) == EXIT_SUCCESS)
    163     archive_handle->action_data(archive_handle);
    164     free(make_me);
    165     goto next_link;
    166     }
    167     cur = cur->next;
    168     }
    169     /* Oops... no file with such inode was created... do it now
    170     * (happens when hardlinked files are empty (zero length)) */
    171     if (archive_handle->filter(archive_handle) == EXIT_SUCCESS)
    172     archive_handle->action_data(archive_handle);
    173     /* Move to the list of created hardlinked files */
    174 niro 984 make_me->next = archive_handle->cpio__created_hardlinks;
    175     archive_handle->cpio__created_hardlinks = make_me;
    176 niro 816 next_link: ;
    177     }
    178    
    179 niro 984 while (archive_handle->cpio__created_hardlinks) {
    180     hardlinks_t *p = archive_handle->cpio__created_hardlinks;
    181     archive_handle->cpio__created_hardlinks = p->next;
    182 niro 816 free(p);
    183     }
    184    
    185     return EXIT_FAILURE; /* "No more files to process" */
    186 niro 532 }