git.maemo.org Git - busybox4maemo/blob - archival/libunarchive/get_header_cpio.c

   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_s {
  11         char *name;
  12         int inode;
  13         struct hardlinks_s *next;
  14 } hardlinks_t;
  15
  16 char get_header_cpio(archive_handle_t *archive_handle)
  17 {
  18         static hardlinks_t *saved_hardlinks = NULL;
  19         static unsigned pending_hardlinks = 0;
  20         static int inode;
  21
  22         file_header_t *file_header = archive_handle->file_header;
  23         char cpio_header[110];
  24         int namesize;
  25         char dummy[16];
  26         int major, minor, nlink;
  27
  28         if (pending_hardlinks) { /* Deal with any pending hardlinks */
  29                 hardlinks_t *tmp, *oldtmp;
  30
  31                 tmp = saved_hardlinks;
  32                 oldtmp = NULL;
  33
  34                 file_header->link_target = file_header->name;
  35                 file_header->size = 0;
  36
  37                 while (tmp) {
  38                         if (tmp->inode != inode) {
  39                                 tmp = tmp->next;
  40                                 continue;
  41                         }
  42
  43                         file_header->name = tmp->name;
  44
  45                         if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
  46                                 archive_handle->action_data(archive_handle);
  47                                 archive_handle->action_header(archive_handle->file_header);
  48                         }
  49
  50                         pending_hardlinks--;
  51
  52                         oldtmp = tmp;
  53                         tmp = tmp->next;
  54                         free(oldtmp->name);
  55                         free(oldtmp);
  56                         if (oldtmp == saved_hardlinks)
  57                                 saved_hardlinks = tmp;
  58                 }
  59
  60                 file_header->name = file_header->link_target;
  61
  62                 if (pending_hardlinks > 1) {
  63                         bb_error_msg("error resolving hardlink: archive made by GNU cpio 2.0-2.2?");
  64                 }
  65
  66                 /* No more pending hardlinks, read next file entry */
  67                 pending_hardlinks = 0;
  68         }
  69
  70         /* There can be padding before archive header */
  71         data_align(archive_handle, 4);
  72
  73         if (archive_xread_all_eof(archive_handle, (unsigned char*)cpio_header, 110) == 0) {
  74                 return EXIT_FAILURE;
  75         }
  76         archive_handle->offset += 110;
  77
  78         if (strncmp(&cpio_header[0], "07070", 5) != 0
  79          || (cpio_header[5] != '1' && cpio_header[5] != '2')
  80         ) {
  81                 bb_error_msg_and_die("unsupported cpio format, use newc or crc");
  82         }
  83
  84         {
  85                 unsigned long tmpsize;
  86                 sscanf(cpio_header, "%6c%8x%8x%8x%8x%8x%8lx%8lx%16c%8x%8x%8x%8c",
  87                     dummy, &inode, (unsigned int*)&file_header->mode,
  88                     (unsigned int*)&file_header->uid, (unsigned int*)&file_header->gid,
  89                     &nlink, &file_header->mtime, &tmpsize,
  90                     dummy, &major, &minor, &namesize, dummy);
  91                 file_header->size = tmpsize;
  92         }
  93
  94         free(file_header->name);
  95         file_header->name = xzalloc(namesize + 1);
  96         /* Read in filename */
  97         xread(archive_handle->src_fd, file_header->name, namesize);
  98         archive_handle->offset += namesize;
  99
 100         /* Update offset amount and skip padding before file contents */
 101         data_align(archive_handle, 4);
 102
 103         if (strcmp(file_header->name, "TRAILER!!!") == 0) {
 104                 /* Always round up */
 105                 printf("%d blocks\n", (int) (archive_handle->offset % 512 ?
 106                                              archive_handle->offset / 512 + 1 :
 107                                              archive_handle->offset / 512
 108                                             ));
 109                 if (saved_hardlinks) { /* Bummer - we still have unresolved hardlinks */
 110                         hardlinks_t *tmp = saved_hardlinks;
 111                         hardlinks_t *oldtmp = NULL;
 112                         while (tmp) {
 113                                 bb_error_msg("%s not created: cannot resolve hardlink", tmp->name);
 114                                 oldtmp = tmp;
 115                                 tmp = tmp->next;
 116                                 free(oldtmp->name);
 117                                 free(oldtmp);
 118                         }
 119                         saved_hardlinks = NULL;
 120                         pending_hardlinks = 0;
 121                 }
 122                 return EXIT_FAILURE;
 123         }
 124
 125         if (S_ISLNK(file_header->mode)) {
 126                 file_header->link_target = xzalloc(file_header->size + 1);
 127                 xread(archive_handle->src_fd, file_header->link_target, file_header->size);
 128                 archive_handle->offset += file_header->size;
 129                 file_header->size = 0; /* Stop possible seeks in future */
 130         } else {
 131                 file_header->link_target = NULL;
 132         }
 133         if (nlink > 1 && !S_ISDIR(file_header->mode)) {
 134                 if (file_header->size == 0) { /* Put file on a linked list for later */
 135                         hardlinks_t *new = xmalloc(sizeof(hardlinks_t));
 136                         new->next = saved_hardlinks;
 137                         new->inode = inode;
 138                         /* name current allocated, freed later */
 139                         new->name = file_header->name;
 140                         file_header->name = NULL;
 141                         saved_hardlinks = new;
 142                         return EXIT_SUCCESS; /* Skip this one */
 143                 }
 144                 /* Found the file with data in */
 145                 pending_hardlinks = nlink;
 146         }
 147         file_header->device = makedev(major, minor);
 148
 149         if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
 150                 archive_handle->action_data(archive_handle);
 151                 archive_handle->action_header(archive_handle->file_header);
 152         } else {
 153                 data_skip(archive_handle);
 154         }
 155
 156         archive_handle->offset += file_header->size;
 157
 158         free(file_header->link_target);
 159
 160         return EXIT_SUCCESS;
 161 }