archival/libunarchive/get_header_cpio.c

   1 /* Copyright 2002 Laurence Anderson
   2  *
   3  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   4  */
   5
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <unistd.h>
  10 #include <sys/sysmacros.h>     /* major() and minor() */
  11 #include "unarchive.h"
  12 #include "libbb.h"
  13
  14 typedef struct hardlinks_s {
  15         file_header_t *entry;
  16         int inode;
  17         struct hardlinks_s *next;
  18 } hardlinks_t;
  19
  20 char get_header_cpio(archive_handle_t *archive_handle)
  21 {
  22         static hardlinks_t *saved_hardlinks = NULL;
  23         static unsigned short pending_hardlinks = 0;
  24         file_header_t *file_header = archive_handle->file_header;
  25         char cpio_header[110];
  26         int namesize;
  27         char dummy[16];
  28         int major, minor, nlink, inode;
  29
  30         if (pending_hardlinks) { /* Deal with any pending hardlinks */
  31                 hardlinks_t *tmp;
  32                 hardlinks_t *oldtmp;
  33
  34                 tmp = saved_hardlinks;
  35                 oldtmp = NULL;
  36
  37                 while (tmp) {
  38                         bb_error_msg_and_die("need to fix this\n");
  39                         if (tmp->entry->link_name) { /* Found a hardlink ready to be extracted */
  40                                 file_header = tmp->entry;
  41                                 if (oldtmp) {
  42                                         oldtmp->next = tmp->next; /* Remove item from linked list */
  43                                 } else {
  44                                         saved_hardlinks = tmp->next;
  45                                 }
  46                                 free(tmp);
  47                                 continue;
  48                         }
  49                         oldtmp = tmp;
  50                         tmp = tmp->next;
  51                 }
  52                 pending_hardlinks = 0; /* No more pending hardlinks, read next file entry */
  53         }
  54
  55         /* There can be padding before archive header */
  56         data_align(archive_handle, 4);
  57
  58         if (archive_xread_all_eof(archive_handle, (unsigned char*)cpio_header, 110) == 0) {
  59                 return(EXIT_FAILURE);
  60         }
  61         archive_handle->offset += 110;
  62
  63         if ((strncmp(&cpio_header[0], "07070", 5) != 0) || ((cpio_header[5] != '1') && (cpio_header[5] != '2'))) {
  64                 bb_error_msg_and_die("Unsupported cpio format, use newc or crc");
  65         }
  66
  67         {
  68             unsigned long tmpsize;
  69             sscanf(cpio_header, "%6c%8x%8x%8x%8x%8x%8lx%8lx%16c%8x%8x%8x%8c",
  70                     dummy, &inode, (unsigned int*)&file_header->mode,
  71                     (unsigned int*)&file_header->uid, (unsigned int*)&file_header->gid,
  72                     &nlink, &file_header->mtime, &tmpsize,
  73                     dummy, &major, &minor, &namesize, dummy);
  74             file_header->size = tmpsize;
  75         }
  76
  77         file_header->name = (char *) xzalloc(namesize + 1);
  78         archive_xread_all(archive_handle, file_header->name, namesize); /* Read in filename */
  79         archive_handle->offset += namesize;
  80
  81         /* Update offset amount and skip padding before file contents */
  82         data_align(archive_handle, 4);
  83
  84         if (strcmp(file_header->name, "TRAILER!!!") == 0) {
  85                 printf("%d blocks\n", (int) (archive_handle->offset % 512 ? (archive_handle->offset / 512) + 1 : archive_handle->offset / 512)); /* Always round up */
  86                 if (saved_hardlinks) { /* Bummer - we still have unresolved hardlinks */
  87                         hardlinks_t *tmp = saved_hardlinks;
  88                         hardlinks_t *oldtmp = NULL;
  89                         while (tmp) {
  90                                 bb_error_msg("%s not created: cannot resolve hardlink", tmp->entry->name);
  91                                 oldtmp = tmp;
  92                                 tmp = tmp->next;
  93                                 free (oldtmp->entry->name);
  94                                 free (oldtmp->entry);
  95                                 free (oldtmp);
  96                         }
  97                         saved_hardlinks = NULL;
  98                         pending_hardlinks = 0;
  99                 }
 100                 return(EXIT_FAILURE);
 101         }
 102
 103         if (S_ISLNK(file_header->mode)) {
 104                 file_header->link_name = (char *) xzalloc(file_header->size + 1);
 105                 archive_xread_all(archive_handle, file_header->link_name, file_header->size);
 106                 archive_handle->offset += file_header->size;
 107                 file_header->size = 0; /* Stop possible seeks in future */
 108         } else {
 109                 file_header->link_name = NULL;
 110         }
 111         if (nlink > 1 && !S_ISDIR(file_header->mode)) {
 112                 if (file_header->size == 0) { /* Put file on a linked list for later */
 113                         hardlinks_t *new = xmalloc(sizeof(hardlinks_t));
 114                         new->next = saved_hardlinks;
 115                         new->inode = inode;
 116                         new->entry = file_header;
 117                         saved_hardlinks = new;
 118                         return(EXIT_SUCCESS); // Skip this one
 119                 } else { /* Found the file with data in */
 120                         hardlinks_t *tmp = saved_hardlinks;
 121                         pending_hardlinks = 1;
 122                         while (tmp) {
 123                                 if (tmp->inode == inode) {
 124                                         tmp->entry->link_name = bb_xstrdup(file_header->name);
 125                                         nlink--;
 126                                 }
 127                                 tmp = tmp->next;
 128                         }
 129                         if (nlink > 1) {
 130                                 bb_error_msg("error resolving hardlink: did you create the archive with GNU cpio 2.0-2.2?");
 131                         }
 132                 }
 133         }
 134         file_header->device = makedev(major, minor);
 135
 136         if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
 137                 archive_handle->action_data(archive_handle);
 138                 archive_handle->action_header(archive_handle->file_header);
 139         } else {
 140                 data_skip(archive_handle);
 141         }
 142
 143         archive_handle->offset += file_header->size;
 144
 145         free(file_header->link_name);
 146
 147         return (EXIT_SUCCESS);
 148 }