u-tools/apps/busybox/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 #if ENABLE_FEATURE_CPIO_O
  18 static off_t cpio_pad4(off_t size)
  19 {
  20         int i;
  21
  22         i = (- size) & 3;
  23         size += i;
  24         while (--i >= 0)
  25                 bb_putchar('\0');
  26         return size;
  27 }
  28
  29 /* Return value will become exit code.
  30  * It's ok to exit instead of return. */
  31 static int cpio_o(void)
  32 {
  33         static const char trailer[] ALIGN1 = "TRAILER!!!";
  34         struct name_s {
  35                 struct name_s *next;
  36                 char name[1];
  37         };
  38         struct inodes_s {
  39                 struct inodes_s *next;
  40                 struct name_s *names;
  41                 struct stat st;
  42         };
  43
  44         struct inodes_s *links = NULL;
  45         off_t bytes = 0; /* output bytes count */
  46
  47         while (1) {
  48                 const char *name;
  49                 char *line;
  50                 struct stat st;
  51
  52                 line = xmalloc_fgetline(stdin);
  53
  54                 if (line) {
  55                         /* Strip leading "./[./]..." from the filename */
  56                         name = line;
  57                         while (name[0] == '.' && name[1] == '/') {
  58                                 while (*++name == '/')
  59                                         continue;
  60                         }
  61                         if (!*name) { /* line is empty */
  62                                 free(line);
  63                                 continue;
  64                         }
  65                         if (lstat(name, &st)) {
  66  abort_cpio_o:
  67                                 bb_simple_perror_msg_and_die(name);
  68                         }
  69
  70                         if (!(S_ISLNK(st.st_mode) || S_ISREG(st.st_mode)))
  71                                 st.st_size = 0; /* paranoia */
  72
  73                         /* Store hardlinks for later processing, dont output them */
  74                         if (!S_ISDIR(st.st_mode) && st.st_nlink > 1) {
  75                                 struct name_s *n;
  76                                 struct inodes_s *l;
  77
  78                                 /* Do we have this hardlink remembered? */
  79                                 l = links;
  80                                 while (1) {
  81                                         if (l == NULL) {
  82                                                 /* Not found: add new item to "links" list */
  83                                                 l = xzalloc(sizeof(*l));
  84                                                 l->st = st;
  85                                                 l->next = links;
  86                                                 links = l;
  87                                                 break;
  88                                         }
  89                                         if (l->st.st_ino == st.st_ino) {
  90                                                 /* found */
  91                                                 break;
  92                                         }
  93                                         l = l->next;
  94                                 }
  95                                 /* Add new name to "l->names" list */
  96                                 n = xmalloc(sizeof(*n) + strlen(name));
  97                                 strcpy(n->name, name);
  98                                 n->next = l->names;
  99                                 l->names = n;
 100
 101                                 free(line);
 102                                 continue;
 103                         }
 104
 105                 } else { /* line == NULL: EOF */
 106  next_link:
 107                         if (links) {
 108                                 /* Output hardlink's data */
 109                                 st = links->st;
 110                                 name = links->names->name;
 111                                 links->names = links->names->next;
 112                                 /* GNU cpio is reported to emit file data
 113                                  * only for the last instance. Mimic that. */
 114                                 if (links->names == NULL)
 115                                         links = links->next;
 116                                 else
 117                                         st.st_size = 0;
 118                                 /* NB: we leak links->names and/or links,
 119                                  * this is intended (we exit soon anyway) */
 120                         } else {
 121                                 /* If no (more) hardlinks to output,
 122                                  * output "trailer" entry */
 123                                 name = trailer;
 124                                 /* st.st_size == 0 is a must, but for uniformity
 125                                  * in the output, we zero out everything */
 126                                 memset(&st, 0, sizeof(st));
 127                                 /* st.st_nlink = 1; - GNU cpio does this */
 128                         }
 129                 }
 130
 131                 bytes += printf("070701"
 132                                 "%08X%08X%08X%08X%08X%08X%08X"
 133                                 "%08X%08X%08X%08X" /* GNU cpio uses uppercase hex */
 134                                 /* strlen+1: */ "%08X"
 135                                 /* chksum: */   "00000000" /* (only for "070702" files) */
 136                                 /* name,NUL: */ "%s%c",
 137                                 (unsigned)(uint32_t) st.st_ino,
 138                                 (unsigned)(uint32_t) st.st_mode,
 139                                 (unsigned)(uint32_t) st.st_uid,
 140                                 (unsigned)(uint32_t) st.st_gid,
 141                                 (unsigned)(uint32_t) st.st_nlink,
 142                                 (unsigned)(uint32_t) st.st_mtime,
 143                                 (unsigned)(uint32_t) st.st_size,
 144                                 (unsigned)(uint32_t) major(st.st_dev),
 145                                 (unsigned)(uint32_t) minor(st.st_dev),
 146                                 (unsigned)(uint32_t) major(st.st_rdev),
 147                                 (unsigned)(uint32_t) minor(st.st_rdev),
 148                                 (unsigned)(strlen(name) + 1),
 149                                 name, '\0');
 150                 bytes = cpio_pad4(bytes);
 151
 152                 if (st.st_size) {
 153                         if (S_ISLNK(st.st_mode)) {
 154                                 char *lpath = xmalloc_readlink_or_warn(name);
 155                                 if (!lpath)
 156                                         goto abort_cpio_o;
 157                                 bytes += printf("%s", lpath);
 158                                 free(lpath);
 159                         } else { /* S_ISREG */
 160                                 int fd = xopen(name, O_RDONLY);
 161                                 fflush(stdout);
 162                                 /* We must abort if file got shorter too! */
 163                                 bb_copyfd_exact_size(fd, STDOUT_FILENO, st.st_size);
 164                                 bytes += st.st_size;
 165                                 close(fd);
 166                         }
 167                         bytes = cpio_pad4(bytes);
 168                 }
 169
 170                 if (!line) {
 171                         if (name != trailer)
 172                                 goto next_link;
 173                         /* TODO: GNU cpio pads trailer to 512 bytes, do we want that? */
 174                         return EXIT_SUCCESS;
 175                 }
 176
 177                 free(line);
 178         } /* end of "while (1)" */
 179 }
 180 #endif
 181
 182 /* GNU cpio 2.9 --help (abridged):
 183
 184  Modes:
 185   -i, --extract              Extract files from an archive
 186   -o, --create               Create the archive
 187   -p, --pass-through         Copy-pass mode [was ist das?!]
 188   -t, --list                 List the archive
 189
 190  Options valid in any mode:
 191       --block-size=SIZE      I/O block size = SIZE * 512 bytes
 192   -B                         I/O block size = 5120 bytes
 193   -c                         Use the old portable (ASCII) archive format
 194   -C, --io-size=NUMBER       I/O block size in bytes
 195   -f, --nonmatching          Only copy files that do not match given pattern
 196   -F, --file=FILE            Use FILE instead of standard input or output
 197   -H, --format=FORMAT        Use given archive FORMAT
 198   -M, --message=STRING       Print STRING when the end of a volume of the
 199                              backup media is reached
 200   -n, --numeric-uid-gid      If -v, show numeric UID and GID
 201       --quiet                Do not print the number of blocks copied
 202       --rsh-command=COMMAND  Use remote COMMAND instead of rsh
 203   -v, --verbose              Verbosely list the files processed
 204   -V, --dot                  Print a "." for each file processed
 205   -W, --warning=FLAG         Control warning display: 'none','truncate','all';
 206                              multiple options accumulate
 207
 208  Options valid only in --extract mode:
 209   -b, --swap                 Swap both halfwords of words and bytes of
 210                              halfwords in the data (equivalent to -sS)
 211   -r, --rename               Interactively rename files
 212   -s, --swap-bytes           Swap the bytes of each halfword in the files
 213   -S, --swap-halfwords       Swap the halfwords of each word (4 bytes)
 214       --to-stdout            Extract files to standard output
 215   -E, --pattern-file=FILE    Read additional patterns specifying filenames to
 216                              extract or list from FILE
 217       --only-verify-crc      Verify CRC's, don't actually extract the files
 218
 219  Options valid only in --create mode:
 220   -A, --append               Append to an existing archive
 221   -O FILE                    File to use instead of standard output
 222
 223  Options valid only in --pass-through mode:
 224   -l, --link                 Link files instead of copying them, when possible
 225
 226  Options valid in --extract and --create modes:
 227       --absolute-filenames   Do not strip file system prefix components from
 228                              the file names
 229       --no-absolute-filenames Create all files relative to the current dir
 230
 231  Options valid in --create and --pass-through modes:
 232   -0, --null                 A list of filenames is terminated by a NUL
 233   -a, --reset-access-time    Reset the access times of files after reading them
 234   -I FILE                    File to use instead of standard input
 235   -L, --dereference          Dereference symbolic links (copy the files
 236                              that they point to instead of copying the links)
 237   -R, --owner=[USER][:.][GROUP] Set owner of created files
 238
 239  Options valid in --extract and --pass-through modes:
 240   -d, --make-directories     Create leading directories where needed
 241   -m, --preserve-modification-time  Retain mtime when creating files
 242       --no-preserve-owner    Do not change the ownership of the files
 243       --sparse               Write files with blocks of zeros as sparse files
 244   -u, --unconditional        Replace all files unconditionally
 245  */
 246
 247 int cpio_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 248 int cpio_main(int argc UNUSED_PARAM, char **argv)
 249 {
 250         archive_handle_t *archive_handle;
 251         char *cpio_filename;
 252         USE_FEATURE_CPIO_O(const char *cpio_fmt = "";)
 253         unsigned opt;
 254         enum {
 255                 CPIO_OPT_EXTRACT            = (1 << 0),
 256                 CPIO_OPT_TEST               = (1 << 1),
 257                 CPIO_OPT_UNCONDITIONAL      = (1 << 2),
 258                 CPIO_OPT_VERBOSE            = (1 << 3),
 259                 CPIO_OPT_FILE               = (1 << 4),
 260                 CPIO_OPT_CREATE_LEADING_DIR = (1 << 5),
 261                 CPIO_OPT_PRESERVE_MTIME     = (1 << 6),
 262                 CPIO_OPT_CREATE             = (1 << 7),
 263                 CPIO_OPT_FORMAT             = (1 << 8),
 264         };
 265
 266 #if ENABLE_GETOPT_LONG
 267         applet_long_options =
 268                 "extract\0"      No_argument       "i"
 269                 "list\0"         No_argument       "t"
 270 #if ENABLE_FEATURE_CPIO_O
 271                 "create\0"       No_argument       "o"
 272                 "format\0"       Required_argument "H"
 273 #endif
 274                 ;
 275 #endif
 276
 277         /* Initialize */
 278         archive_handle = init_handle();
 279         archive_handle->src_fd = STDIN_FILENO;
 280         archive_handle->seek = seek_by_read;
 281         archive_handle->ah_flags = ARCHIVE_EXTRACT_NEWER;
 282
 283 #if ENABLE_FEATURE_CPIO_O
 284         opt = getopt32(argv, "ituvF:dmoH:", &cpio_filename, &cpio_fmt);
 285
 286         if (opt & CPIO_OPT_CREATE) {
 287                 if (*cpio_fmt != 'n')
 288                         bb_show_usage();
 289                 if (opt & CPIO_OPT_FILE) {
 290                         fclose(stdout);
 291                         stdout = fopen_for_write(cpio_filename);
 292                         /* Paranoia: I don't trust libc that much */
 293                         xdup2(fileno(stdout), STDOUT_FILENO);
 294                 }
 295                 return cpio_o();
 296         }
 297 #else
 298         opt = getopt32(argv, "ituvF:dm", &cpio_filename);
 299 #endif
 300         argv += optind;
 301
 302         /* One of either extract or test options must be given */
 303         if ((opt & (CPIO_OPT_TEST | CPIO_OPT_EXTRACT)) == 0) {
 304                 bb_show_usage();
 305         }
 306
 307         if (opt & CPIO_OPT_TEST) {
 308                 /* if both extract and test options are given, ignore extract option */
 309                 if (opt & CPIO_OPT_EXTRACT) {
 310                         opt &= ~CPIO_OPT_EXTRACT;
 311                 }
 312                 archive_handle->action_header = header_list;
 313         }
 314         if (opt & CPIO_OPT_EXTRACT) {
 315                 archive_handle->action_data = data_extract_all;
 316         }
 317         if (opt & CPIO_OPT_UNCONDITIONAL) {
 318                 archive_handle->ah_flags |= ARCHIVE_EXTRACT_UNCONDITIONAL;
 319                 archive_handle->ah_flags &= ~ARCHIVE_EXTRACT_NEWER;
 320         }
 321         if (opt & CPIO_OPT_VERBOSE) {
 322                 if (archive_handle->action_header == header_list) {
 323                         archive_handle->action_header = header_verbose_list;
 324                 } else {
 325                         archive_handle->action_header = header_list;
 326                 }
 327         }
 328         if (opt & CPIO_OPT_FILE) { /* -F */
 329                 archive_handle->src_fd = xopen(cpio_filename, O_RDONLY);
 330                 archive_handle->seek = seek_by_jump;
 331         }
 332         if (opt & CPIO_OPT_CREATE_LEADING_DIR) {
 333                 archive_handle->ah_flags |= ARCHIVE_CREATE_LEADING_DIRS;
 334         }
 335         if (opt & CPIO_OPT_PRESERVE_MTIME) {
 336                 archive_handle->ah_flags |= ARCHIVE_PRESERVE_DATE;
 337         }
 338
 339         while (*argv) {
 340                 archive_handle->filter = filter_accept_list;
 341                 llist_add_to(&(archive_handle->accept), *argv);
 342                 argv++;
 343         }
 344
 345         /* see get_header_cpio */
 346         archive_handle->ah_priv[2] = (void*) ~(ptrdiff_t)0;
 347         while (get_header_cpio(archive_handle) == EXIT_SUCCESS)
 348                 continue;
 349
 350         if (archive_handle->ah_priv[2] != (void*) ~(ptrdiff_t)0)
 351                 printf("%lu blocks\n", (unsigned long)(ptrdiff_t)(archive_handle->ah_priv[2]));
 352
 353         return EXIT_SUCCESS;
 354 }