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