archival/libunarchive/get_header_cpio.c

   1 /*
   2  *  This program is free software; you can redistribute it and/or modify
   3  *  it under the terms of the GNU General Public License as published by
   4  *  the Free Software Foundation; either version 2 of the License, or
   5  *  (at your option) any later version.
   6  *
   7  *  This program is distributed in the hope that it will be useful,
   8  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  *  GNU Library General Public License for more details.
  11  *
  12  *  You should have received a copy of the GNU General Public License
  13  *  along with this program; if not, write to the Free Software
  14  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  15  */
  16
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20 #include <unistd.h>
  21 #include "unarchive.h"
  22 #include "libbb.h"
  23
  24 typedef struct hardlinks_s {
  25         file_header_t *entry;
  26         int inode;
  27         struct hardlinks_s *next;
  28 } hardlinks_t;
  29
  30 extern char get_header_cpio(archive_handle_t *archive_handle)
  31 {
  32         static hardlinks_t *saved_hardlinks = NULL;
  33         static unsigned short pending_hardlinks = 0;
  34         file_header_t *file_header = archive_handle->file_header;
  35         char cpio_header[110];
  36         int namesize;
  37         char dummy[16];
  38         int major, minor, nlink, inode;
  39
  40         if (pending_hardlinks) { /* Deal with any pending hardlinks */
  41                 hardlinks_t *tmp;
  42                 hardlinks_t *oldtmp;
  43
  44                 tmp = saved_hardlinks;
  45                 oldtmp = NULL;
  46
  47                 while (tmp) {
  48                         bb_error_msg_and_die("need to fix this\n");
  49                         if (tmp->entry->link_name) { /* Found a hardlink ready to be extracted */
  50                                 file_header = tmp->entry;
  51                                 if (oldtmp) {
  52                                         oldtmp->next = tmp->next; /* Remove item from linked list */
  53                                 } else {
  54                                         saved_hardlinks = tmp->next;
  55                                 }
  56                                 free(tmp);
  57                                 continue;
  58                         }
  59                         oldtmp = tmp;
  60                         tmp = tmp->next;
  61                 }
  62                 pending_hardlinks = 0; /* No more pending hardlinks, read next file entry */
  63         }
  64
  65         /* There can be padding before archive header */
  66         data_align(archive_handle, 4);
  67
  68         if (archive_xread_all_eof(archive_handle, cpio_header, 110) == 0) {
  69                 return(EXIT_FAILURE);
  70         }
  71         archive_handle->offset += 110;
  72
  73         if ((strncmp(&cpio_header[0], "07070", 5) != 0) || ((cpio_header[5] != '1') && (cpio_header[5] != '2'))) {
  74                 bb_error_msg_and_die("Unsupported cpio format, use newc or crc");
  75         }
  76
  77         {
  78             unsigned long tmpsize;
  79             sscanf(cpio_header, "%6c%8x%8x%8x%8x%8x%8lx%8lx%16c%8x%8x%8x%8c",
  80                     dummy, &inode, (unsigned int*)&file_header->mode,
  81                     (unsigned int*)&file_header->uid, (unsigned int*)&file_header->gid,
  82                     &nlink, &file_header->mtime, &tmpsize,
  83                     dummy, &major, &minor, &namesize, dummy);
  84             file_header->size = tmpsize;
  85         }
  86
  87         file_header->name = (char *) xmalloc(namesize + 1);
  88         archive_xread_all(archive_handle, file_header->name, namesize); /* Read in filename */
  89         file_header->name[namesize] = '\0';
  90         archive_handle->offset += namesize;
  91
  92         /* Update offset amount and skip padding before file contents */
  93         data_align(archive_handle, 4);
  94
  95         if (strcmp(file_header->name, "TRAILER!!!") == 0) {
  96                 printf("%d blocks\n", (int) (archive_handle->offset % 512 ? (archive_handle->offset / 512) + 1 : archive_handle->offset / 512)); /* Always round up */
  97                 if (saved_hardlinks) { /* Bummer - we still have unresolved hardlinks */
  98                         hardlinks_t *tmp = saved_hardlinks;
  99                         hardlinks_t *oldtmp = NULL;
 100                         while (tmp) {
 101                                 bb_error_msg("%s not created: cannot resolve hardlink", tmp->entry->name);
 102                                 oldtmp = tmp;
 103                                 tmp = tmp->next;
 104                                 free (oldtmp->entry->name);
 105                                 free (oldtmp->entry);
 106                                 free (oldtmp);
 107                         }
 108                         saved_hardlinks = NULL;
 109                         pending_hardlinks = 0;
 110                 }
 111                 return(EXIT_FAILURE);
 112         }
 113
 114         if (S_ISLNK(file_header->mode)) {
 115                 file_header->link_name = (char *) xmalloc(file_header->size + 1);
 116                 archive_xread_all(archive_handle, file_header->link_name, file_header->size);
 117                 file_header->link_name[file_header->size] = '\0';
 118                 archive_handle->offset += file_header->size;
 119                 file_header->size = 0; /* Stop possible seeks in future */
 120         }
 121         if (nlink > 1 && !S_ISDIR(file_header->mode)) {
 122                 if (file_header->size == 0) { /* Put file on a linked list for later */
 123                         hardlinks_t *new = xmalloc(sizeof(hardlinks_t));
 124                         new->next = saved_hardlinks;
 125                         new->inode = inode;
 126                         new->entry = file_header;
 127                         saved_hardlinks = new;
 128                         return(EXIT_SUCCESS); // Skip this one
 129                 } else { /* Found the file with data in */
 130                         hardlinks_t *tmp = saved_hardlinks;
 131                         pending_hardlinks = 1;
 132                         while (tmp) {
 133                                 if (tmp->inode == inode) {
 134                                         tmp->entry->link_name = bb_xstrdup(file_header->name);
 135                                         nlink--;
 136                                 }
 137                                 tmp = tmp->next;
 138                         }
 139                         if (nlink > 1) {
 140                                 bb_error_msg("error resolving hardlink: did you create the archive with GNU cpio 2.0-2.2?");
 141                         }
 142                 }
 143         }
 144         file_header->device = (major << 8) | minor;
 145
 146         if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
 147                 archive_handle->action_data(archive_handle);
 148                 archive_handle->action_header(archive_handle->file_header);
 149         } else {
 150                 data_skip(archive_handle);
 151         }
 152
 153         archive_handle->offset += file_header->size;
 154         return (EXIT_SUCCESS);
 155 }