archival/cpio.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini cpio implementation for busybox
   4  *
   5  * Copyright (C) 2001 by Glenn McGrath
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  *
  21  * Limitations:
  22  *              Doesn't check CRC's
  23  *              Only supports new ASCII and CRC formats
  24  *
  25  */
  26 #include <fcntl.h>
  27 #include <getopt.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <unistd.h>
  31 #include "unarchive.h"
  32 #include "busybox.h"
  33
  34 typedef struct hardlinks_s {
  35         file_header_t *entry;
  36         int inode;
  37         struct hardlinks_s *next;
  38 } hardlinks_t;
  39
  40 extern int cpio_main(int argc, char **argv)
  41 {
  42         archive_handle_t *archive_handle;
  43         int opt;
  44
  45         /* Initialise */
  46         archive_handle = init_handle();
  47         archive_handle->src_fd = fileno(stdin);
  48         archive_handle->action_header = header_list;
  49
  50         while ((opt = getopt(argc, argv, "idmuvtF:")) != -1) {
  51                 switch (opt) {
  52                 case 'i': /* extract */
  53                         archive_handle->action_data = data_extract_all;
  54                         break;
  55                 case 'd': /* create _leading_ directories */
  56                         archive_handle->flags |= ARCHIVE_CREATE_LEADING_DIRS;
  57                         break;
  58                 case 'm': /* preserve modification time */
  59                         archive_handle->flags |= ARCHIVE_PRESERVE_DATE;
  60                         break;
  61                 case 'v': /* verbosly list files */
  62                         archive_handle->action_header = header_verbose_list;
  63                         break;
  64                 case 'u': /* unconditional */
  65                         archive_handle->flags |= ARCHIVE_EXTRACT_UNCONDITIONAL;
  66                         break;
  67                 case 't': /* list files */
  68                         archive_handle->action_header = header_list;
  69                         break;
  70                 case 'F':
  71                         archive_handle->src_fd = xopen(optarg, O_RDONLY);
  72                         break;
  73                 default:
  74                         show_usage();
  75                 }
  76         }
  77
  78         while (optind < argc) {
  79                 archive_handle->filter = filter_accept_list;
  80                 archive_handle->accept = add_to_list(archive_handle->accept, argv[optind]);
  81                 optind++;
  82         }
  83
  84         while (1) {
  85                 static hardlinks_t *saved_hardlinks = NULL;
  86                 static unsigned short pending_hardlinks = 0;
  87                 file_header_t *file_header = archive_handle->file_header;
  88                 char cpio_header[110];
  89                 int namesize;
  90                 char dummy[16];
  91                 int major, minor, nlink, inode;
  92                 char extract_flag;
  93
  94                 if (pending_hardlinks) { /* Deal with any pending hardlinks */
  95                         hardlinks_t *tmp;
  96                         hardlinks_t *oldtmp;
  97
  98                         tmp = saved_hardlinks;
  99                         oldtmp = NULL;
 100
 101                         while (tmp) {
 102                                 error_msg_and_die("need to fix this\n");
 103                                 if (tmp->entry->link_name) { /* Found a hardlink ready to be extracted */
 104                                         file_header = tmp->entry;
 105                                         if (oldtmp) {
 106                                                 oldtmp->next = tmp->next; /* Remove item from linked list */
 107                                         } else {
 108                                                 saved_hardlinks = tmp->next;
 109                                         }
 110                                         free(tmp);
 111                                         continue;
 112                                 }
 113                                 oldtmp = tmp;
 114                                 tmp = tmp->next;
 115                         }
 116                         pending_hardlinks = 0; /* No more pending hardlinks, read next file entry */
 117         }
 118
 119                 /* There can be padding before archive header */
 120                 archive_handle->offset += data_align(archive_handle->src_fd, archive_handle->offset, 4);
 121
 122                 if (xread_all_eof(archive_handle->src_fd, cpio_header, 110) == 0) {
 123                         return(EXIT_FAILURE);
 124                 }
 125                 archive_handle->offset += 110;
 126
 127                 if (strncmp(&cpio_header[0], "07070", 5) != 0) {
 128                         printf("cpio header is %x-%x-%x-%x-%x\n",
 129                                 cpio_header[0],
 130                                 cpio_header[1],
 131                                 cpio_header[2],
 132                                 cpio_header[3],
 133                                 cpio_header[4]);
 134                         error_msg_and_die("Unsupported cpio format");
 135                 }
 136
 137                 if ((cpio_header[5] != '1') && (cpio_header[5] != '2')) {
 138                         error_msg_and_die("Unsupported cpio format, use newc or crc");
 139         }
 140
 141                 sscanf(cpio_header, "%6c%8x%8x%8x%8x%8x%8lx%8lx%16c%8x%8x%8x%8c",
 142                         dummy, &inode, (unsigned int*)&file_header->mode,
 143                         (unsigned int*)&file_header->uid, (unsigned int*)&file_header->gid,
 144                         &nlink, &file_header->mtime, &file_header->size,
 145                         dummy, &major, &minor, &namesize, dummy);
 146
 147                 file_header->name = (char *) xmalloc(namesize + 1);
 148                 xread(archive_handle->src_fd, file_header->name, namesize); /* Read in filename */
 149                 file_header->name[namesize] = '\0';
 150                 archive_handle->offset += namesize;
 151
 152                 /* Update offset amount and skip padding before file contents */
 153                 archive_handle->offset += data_align(archive_handle->src_fd, archive_handle->offset, 4);
 154
 155                 if (strcmp(file_header->name, "TRAILER!!!") == 0) {
 156                         printf("%d blocks\n", (int) (archive_handle->offset % 512 ? (archive_handle->offset / 512) + 1 : archive_handle->offset / 512)); /* Always round up */
 157                         if (saved_hardlinks) { /* Bummer - we still have unresolved hardlinks */
 158                                 hardlinks_t *tmp = saved_hardlinks;
 159                                 hardlinks_t *oldtmp = NULL;
 160                                 while (tmp) {
 161                                         error_msg("%s not created: cannot resolve hardlink", tmp->entry->name);
 162                                         oldtmp = tmp;
 163                                         tmp = tmp->next;
 164                                         free (oldtmp->entry->name);
 165                                         free (oldtmp->entry);
 166                                         free (oldtmp);
 167                                 }
 168                                 saved_hardlinks = NULL;
 169                                 pending_hardlinks = 0;
 170         }
 171                         return(EXIT_FAILURE);
 172                 }
 173
 174                 if (S_ISLNK(file_header->mode)) {
 175                         file_header->link_name = (char *) xmalloc(file_header->size + 1);
 176                         xread(archive_handle->src_fd, file_header->link_name, file_header->size);
 177                         file_header->link_name[file_header->size] = '\0';
 178                         archive_handle->offset += file_header->size;
 179                         file_header->size = 0; /* Stop possible seeks in future */
 180                 }
 181                 if (nlink > 1 && !S_ISDIR(file_header->mode)) {
 182                         if (file_header->size == 0) { /* Put file on a linked list for later */
 183                                 hardlinks_t *new = xmalloc(sizeof(hardlinks_t));
 184                                 new->next = saved_hardlinks;
 185                                 new->inode = inode;
 186                                 new->entry = file_header;
 187                                 saved_hardlinks = new;
 188                                 continue;
 189                         } else { /* Found the file with data in */
 190                                 hardlinks_t *tmp = saved_hardlinks;
 191                                 pending_hardlinks = 1;
 192                                 while (tmp) {
 193                                         if (tmp->inode == inode) {
 194                                                 tmp->entry->link_name = xstrdup(file_header->name);
 195                                                 nlink--;
 196                                         }
 197                                         tmp = tmp->next;
 198                                 }
 199                                 if (nlink > 1) {
 200                                         error_msg("error resolving hardlink: did you create the archive with GNU cpio 2.0-2.2?");
 201                                 }
 202                         }
 203                 }
 204                 file_header->device = (major << 8) | minor;
 205
 206                 extract_flag = FALSE;
 207                 if (archive_handle->filter(archive_handle->accept, archive_handle->reject, file_header->name) == EXIT_SUCCESS) {
 208                         struct stat statbuf;
 209
 210                         extract_flag = TRUE;
 211
 212                         /* Check if the file already exists */
 213                         if (lstat (file_header->name, &statbuf) == 0) {
 214                                 if ((archive_handle->flags & ARCHIVE_EXTRACT_UNCONDITIONAL) || (statbuf.st_mtime < file_header->mtime)) {
 215                                         /* Remove file if flag set or its older than the file to be extracted */
 216                                         if (unlink(file_header->name) == -1) {
 217                                                 perror_msg_and_die("Couldnt remove old file");
 218                                         }
 219                                 } else {
 220                                         if (! archive_handle->flags & ARCHIVE_EXTRACT_QUIET) {
 221                                                 error_msg("%s not created: newer or same age file exists", file_header->name);
 222                                         }
 223                                         extract_flag = FALSE;
 224                                 }
 225                         }
 226                         archive_handle->action_header(file_header);
 227                 }
 228
 229                 archive_handle->action_header(file_header);
 230                 if (extract_flag) {
 231                         archive_handle->action_data(archive_handle);
 232                 } else {
 233                         data_skip(archive_handle);
 234                 }
 235                 archive_handle->offset += file_header->size;
 236         }
 237
 238         return(EXIT_SUCCESS);
 239 }
 240