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         char extract_flag;
  40
  41         if (pending_hardlinks) { /* Deal with any pending hardlinks */
  42                 hardlinks_t *tmp;
  43                 hardlinks_t *oldtmp;
  44
  45                 tmp = saved_hardlinks;
  46                 oldtmp = NULL;
  47
  48                 while (tmp) {
  49                         error_msg_and_die("need to fix this\n");
  50                         if (tmp->entry->link_name) { /* Found a hardlink ready to be extracted */
  51                                 file_header = tmp->entry;
  52                                 if (oldtmp) {
  53                                         oldtmp->next = tmp->next; /* Remove item from linked list */
  54                                 } else {
  55                                         saved_hardlinks = tmp->next;
  56                                 }
  57                                 free(tmp);
  58                                 continue;
  59                         }
  60                         oldtmp = tmp;
  61                         tmp = tmp->next;
  62                 }
  63                 pending_hardlinks = 0; /* No more pending hardlinks, read next file entry */
  64         }
  65
  66         /* There can be padding before archive header */
  67         data_align(archive_handle, 4);
  68
  69         if (archive_xread_all_eof(archive_handle, cpio_header, 110) == 0) {
  70                 return(EXIT_FAILURE);
  71         }
  72         archive_handle->offset += 110;
  73
  74         if (strncmp(&cpio_header[0], "07070", 5) != 0) {
  75                 printf("cpio header is %x-%x-%x-%x-%x\n",
  76                         cpio_header[0],
  77                         cpio_header[1],
  78                         cpio_header[2],
  79                         cpio_header[3],
  80                         cpio_header[4]);
  81                 error_msg_and_die("Unsupported cpio format");
  82         }
  83
  84         if ((cpio_header[5] != '1') && (cpio_header[5] != '2')) {
  85                 error_msg_and_die("Unsupported cpio format, use newc or crc");
  86         }
  87
  88         sscanf(cpio_header, "%6c%8x%8x%8x%8x%8x%8lx%8lx%16c%8x%8x%8x%8c",
  89                 dummy, &inode, (unsigned int*)&file_header->mode,
  90                 (unsigned int*)&file_header->uid, (unsigned int*)&file_header->gid,
  91                 &nlink, &file_header->mtime, (unsigned long*)&file_header->size,
  92                 dummy, &major, &minor, &namesize, dummy);
  93
  94         file_header->name = (char *) xmalloc(namesize + 1);
  95         archive_xread_all(archive_handle, file_header->name, namesize); /* Read in filename */
  96         file_header->name[namesize] = '\0';
  97         archive_handle->offset += namesize;
  98
  99         /* Update offset amount and skip padding before file contents */
 100         data_align(archive_handle, 4);
 101
 102         if (strcmp(file_header->name, "TRAILER!!!") == 0) {
 103                 printf("%d blocks\n", (int) (archive_handle->offset % 512 ? (archive_handle->offset / 512) + 1 : archive_handle->offset / 512)); /* Always round up */
 104                 if (saved_hardlinks) { /* Bummer - we still have unresolved hardlinks */
 105                         hardlinks_t *tmp = saved_hardlinks;
 106                         hardlinks_t *oldtmp = NULL;
 107                         while (tmp) {
 108                                 error_msg("%s not created: cannot resolve hardlink", tmp->entry->name);
 109                                 oldtmp = tmp;
 110                                 tmp = tmp->next;
 111                                 free (oldtmp->entry->name);
 112                                 free (oldtmp->entry);
 113                                 free (oldtmp);
 114                         }
 115                         saved_hardlinks = NULL;
 116                         pending_hardlinks = 0;
 117                 }
 118                 return(EXIT_FAILURE);
 119         }
 120
 121         if (S_ISLNK(file_header->mode)) {
 122                 file_header->link_name = (char *) xmalloc(file_header->size + 1);
 123                 archive_xread_all(archive_handle, file_header->link_name, file_header->size);
 124                 file_header->link_name[file_header->size] = '\0';
 125                 archive_handle->offset += file_header->size;
 126                 file_header->size = 0; /* Stop possible seeks in future */
 127         }
 128         if (nlink > 1 && !S_ISDIR(file_header->mode)) {
 129                 if (file_header->size == 0) { /* Put file on a linked list for later */
 130                         hardlinks_t *new = xmalloc(sizeof(hardlinks_t));
 131                         new->next = saved_hardlinks;
 132                         new->inode = inode;
 133                         new->entry = file_header;
 134                         saved_hardlinks = new;
 135                         return(EXIT_SUCCESS); // Skip this one
 136                 } else { /* Found the file with data in */
 137                         hardlinks_t *tmp = saved_hardlinks;
 138                         pending_hardlinks = 1;
 139                         while (tmp) {
 140                                 if (tmp->inode == inode) {
 141                                         tmp->entry->link_name = xstrdup(file_header->name);
 142                                         nlink--;
 143                                 }
 144                                 tmp = tmp->next;
 145                         }
 146                         if (nlink > 1) {
 147                                 error_msg("error resolving hardlink: did you create the archive with GNU cpio 2.0-2.2?");
 148                         }
 149                 }
 150         }
 151         file_header->device = (major << 8) | minor;
 152
 153         extract_flag = FALSE;
 154         if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
 155                 struct stat statbuf;
 156
 157                 extract_flag = TRUE;
 158
 159                 /* Check if the file already exists */
 160                 if (lstat (file_header->name, &statbuf) == 0) {
 161                         if ((archive_handle->flags & ARCHIVE_EXTRACT_UNCONDITIONAL) || (statbuf.st_mtime < file_header->mtime)) {
 162                                 /* Remove file if flag set or its older than the file to be extracted */
 163                                 if (unlink(file_header->name) == -1) {
 164                                         perror_msg_and_die("Couldnt remove old file");
 165                                 }
 166                         } else {
 167                                 if (! archive_handle->flags & ARCHIVE_EXTRACT_QUIET) {
 168                                         error_msg("%s not created: newer or same age file exists", file_header->name);
 169                                 }
 170                                 extract_flag = FALSE;
 171                         }
 172                 }
 173                 archive_handle->action_header(file_header);
 174         }
 175
 176         archive_handle->action_header(file_header);
 177         if (extract_flag) {
 178                 archive_handle->action_data(archive_handle);
 179         } else {
 180                 data_skip(archive_handle);
 181         }
 182         archive_handle->offset += file_header->size;
 183         return (EXIT_SUCCESS);
 184 }
 185