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  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   8  *
   9  * Limitations:
  10  * Doesn't check CRC's
  11  * Only supports new ASCII and CRC formats
  12  *
  13  */
  14 #include "libbb.h"
  15 #include "unarchive.h"
  16
  17 enum {
  18         CPIO_OPT_EXTRACT            = (1 << 0),
  19         CPIO_OPT_TEST               = (1 << 1),
  20         CPIO_OPT_UNCONDITIONAL      = (1 << 2),
  21         CPIO_OPT_VERBOSE            = (1 << 3),
  22         CPIO_OPT_FILE               = (1 << 4),
  23         CPIO_OPT_CREATE_LEADING_DIR = (1 << 5),
  24         CPIO_OPT_PRESERVE_MTIME     = (1 << 6),
  25         CPIO_OPT_CREATE             = (1 << 7),
  26         CPIO_OPT_FORMAT             = (1 << 8),
  27 };
  28
  29 #if ENABLE_FEATURE_CPIO_O
  30 static off_t cpio_pad4(off_t size)
  31 {
  32         int i;
  33
  34         i = (- size) & 3;
  35         size += i;
  36         while (--i >= 0)
  37                 bb_putchar('\0');
  38         return size;
  39 }
  40
  41 /* Return value will become exit code.
  42  * It's ok to exit instead of return. */
  43 static int cpio_o(void)
  44 {
  45         struct name_s {
  46                 struct name_s *next;
  47                 char name[1];
  48         };
  49         struct inodes_s {
  50                 struct inodes_s *next;
  51                 struct name_s *names;
  52                 struct stat st;
  53         };
  54
  55         struct inodes_s *links = NULL;
  56         off_t bytes = 0; /* output bytes count */
  57
  58         while (1) {
  59                 const char *name;
  60                 char *line;
  61                 struct stat st;
  62
  63                 line = xmalloc_fgetline(stdin);
  64
  65                 if (line) {
  66                         /* Strip leading "./[./]..." from the filename */
  67                         name = line;
  68                         while (name[0] == '.' && name[1] == '/') {
  69                                 while (*++name == '/')
  70                                         continue;
  71                         }
  72                         if (!*name) { /* line is empty */
  73                                 free(line);
  74                                 continue;
  75                         }
  76                         if (lstat(name, &st)) {
  77  abort_cpio_o:
  78                                 bb_simple_perror_msg_and_die(name);
  79                         }
  80
  81                         if (!(S_ISLNK(st.st_mode) || S_ISREG(st.st_mode)))
  82                                 st.st_size = 0; /* paranoia */
  83
  84                         /* Store hardlinks for later processing, dont output them */
  85                         if (!S_ISDIR(st.st_mode) && st.st_nlink > 1) {
  86                                 struct name_s *n;
  87                                 struct inodes_s *l;
  88
  89                                 /* Do we have this hardlink remembered? */
  90                                 l = links;
  91                                 while (1) {
  92                                         if (l == NULL) {
  93                                                 /* Not found: add new item to "links" list */
  94                                                 l = xzalloc(sizeof(*l));
  95                                                 l->st = st;
  96                                                 l->next = links;
  97                                                 links = l;
  98                                                 break;
  99                                         }
 100                                         if (l->st.st_ino == st.st_ino) {
 101                                                 /* found */
 102                                                 break;
 103                                         }
 104                                         l = l->next;
 105                                 }
 106                                 /* Add new name to "l->names" list */
 107                                 n = xmalloc(sizeof(*n) + strlen(name));
 108                                 strcpy(n->name, name);
 109                                 n->next = l->names;
 110                                 l->names = n;
 111
 112                                 free(line);
 113                                 continue;
 114                         }
 115
 116                 } else { /* line == NULL: EOF */
 117  next_link:
 118                         if (links) {
 119                                 /* Output hardlink's data */
 120                                 st = links->st;
 121                                 name = links->names->name;
 122                                 links->names = links->names->next;
 123                                 /* GNU cpio is reported to emit file data
 124                                  * only for the last instance. Mimic that. */
 125                                 if (links->names == NULL)
 126                                         links = links->next;
 127                                 else
 128                                         st.st_size = 0;
 129                                 /* NB: we leak links->names and/or links,
 130                                  * this is intended (we exit soon anyway) */
 131                         } else {
 132                                 /* If no (more) hardlinks to output,
 133                                  * output "trailer" entry */
 134                                 name = "TRAILER!!!";
 135                                 /* st.st_size == 0 is a must, but for uniformity
 136                                  * in the output, we zero out everything */
 137                                 memset(&st, 0, sizeof(st));
 138                                 /* st.st_nlink = 1; - GNU cpio does this */
 139                         }
 140                 }
 141
 142                 bytes += printf("070701"
 143                                 "%08X%08X%08X%08X%08X%08X%08X"
 144                                 "%08X%08X%08X%08X" /* GNU cpio uses uppercase hex */
 145                                 /* strlen+1: */ "%08X"
 146                                 /* chksum: */   "00000000" /* (only for "070702" files) */
 147                                 /* name,NUL: */ "%s%c",
 148                                 (unsigned)(uint32_t) st.st_ino,
 149                                 (unsigned)(uint32_t) st.st_mode,
 150                                 (unsigned)(uint32_t) st.st_uid,
 151                                 (unsigned)(uint32_t) st.st_gid,
 152                                 (unsigned)(uint32_t) st.st_nlink,
 153                                 (unsigned)(uint32_t) st.st_mtime,
 154                                 (unsigned)(uint32_t) st.st_size,
 155                                 (unsigned)(uint32_t) major(st.st_dev),
 156                                 (unsigned)(uint32_t) minor(st.st_dev),
 157                                 (unsigned)(uint32_t) major(st.st_rdev),
 158                                 (unsigned)(uint32_t) minor(st.st_rdev),
 159                                 (unsigned)(strlen(name) + 1),
 160                                 name, '\0');
 161                 bytes = cpio_pad4(bytes);
 162
 163                 if (st.st_size) {
 164                         if (S_ISLNK(st.st_mode)) {
 165                                 char *lpath = xmalloc_readlink_or_warn(name);
 166                                 if (!lpath)
 167                                         goto abort_cpio_o;
 168                                 bytes += printf("%s", lpath);
 169                                 free(lpath);
 170                         } else { /* S_ISREG */
 171                                 int fd = xopen(name, O_RDONLY);
 172                                 fflush(stdout);
 173                                 /* We must abort if file got shorter too! */
 174                                 bb_copyfd_exact_size(fd, STDOUT_FILENO, st.st_size);
 175                                 bytes += st.st_size;
 176                                 close(fd);
 177                         }
 178                         bytes = cpio_pad4(bytes);
 179                 }
 180
 181                 if (!line) {
 182                         if (links)
 183                                 goto next_link;
 184                         /* TODO: GNU cpio pads trailer to 512 bytes, do we want that? */
 185                         return EXIT_SUCCESS;
 186                 }
 187
 188                 free(line);
 189         } /* end of "while (1)" */
 190 }
 191 #endif
 192
 193 int cpio_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 194 int cpio_main(int argc UNUSED_PARAM, char **argv)
 195 {
 196         archive_handle_t *archive_handle;
 197         char *cpio_filename;
 198 #if ENABLE_FEATURE_CPIO_O
 199         const char *cpio_fmt = "";
 200 #endif
 201         unsigned opt;
 202
 203         /* Initialize */
 204         archive_handle = init_handle();
 205         archive_handle->src_fd = STDIN_FILENO;
 206         archive_handle->seek = seek_by_read;
 207         archive_handle->ah_flags = ARCHIVE_EXTRACT_NEWER;
 208
 209 #if ENABLE_FEATURE_CPIO_O
 210         opt = getopt32(argv, "ituvF:dmoH:", &cpio_filename, &cpio_fmt);
 211
 212         if (opt & CPIO_OPT_CREATE) {
 213                 if (*cpio_fmt != 'n')
 214                         bb_show_usage();
 215                 if (opt & CPIO_OPT_FILE) {
 216                         fclose(stdout);
 217                         stdout = fopen(cpio_filename, "w");
 218                         /* Paranoia: I don't trust libc that much */
 219                         xdup2(fileno(stdout), STDOUT_FILENO);
 220                 }
 221                 return cpio_o();
 222         }
 223 #else
 224         opt = getopt32(argv, "ituvF:dm", &cpio_filename);
 225 #endif
 226         argv += optind;
 227
 228         /* One of either extract or test options must be given */
 229         if ((opt & (CPIO_OPT_TEST | CPIO_OPT_EXTRACT)) == 0) {
 230                 bb_show_usage();
 231         }
 232
 233         if (opt & CPIO_OPT_TEST) {
 234                 /* if both extract and test options are given, ignore extract option */
 235                 if (opt & CPIO_OPT_EXTRACT) {
 236                         opt &= ~CPIO_OPT_EXTRACT;
 237                 }
 238                 archive_handle->action_header = header_list;
 239         }
 240         if (opt & CPIO_OPT_EXTRACT) {
 241                 archive_handle->action_data = data_extract_all;
 242         }
 243         if (opt & CPIO_OPT_UNCONDITIONAL) {
 244                 archive_handle->ah_flags |= ARCHIVE_EXTRACT_UNCONDITIONAL;
 245                 archive_handle->ah_flags &= ~ARCHIVE_EXTRACT_NEWER;
 246         }
 247         if (opt & CPIO_OPT_VERBOSE) {
 248                 if (archive_handle->action_header == header_list) {
 249                         archive_handle->action_header = header_verbose_list;
 250                 } else {
 251                         archive_handle->action_header = header_list;
 252                 }
 253         }
 254         if (opt & CPIO_OPT_FILE) { /* -F */
 255                 archive_handle->src_fd = xopen(cpio_filename, O_RDONLY);
 256                 archive_handle->seek = seek_by_jump;
 257         }
 258         if (opt & CPIO_OPT_CREATE_LEADING_DIR) {
 259                 archive_handle->ah_flags |= ARCHIVE_CREATE_LEADING_DIRS;
 260         }
 261         if (opt & CPIO_OPT_PRESERVE_MTIME) {
 262                 archive_handle->ah_flags |= ARCHIVE_PRESERVE_DATE;
 263         }
 264
 265         while (*argv) {
 266                 archive_handle->filter = filter_accept_list;
 267                 llist_add_to(&(archive_handle->accept), *argv);
 268                 argv++;
 269         }
 270
 271         while (get_header_cpio(archive_handle) == EXIT_SUCCESS)
 272                 continue;
 273
 274         return EXIT_SUCCESS;
 275 }