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 source tree.
   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 "archive.h"
  16
  17 //usage:#define cpio_trivial_usage
  18 //usage:       "[-dmvu] [-F FILE]" IF_FEATURE_CPIO_O(" [-H newc]")
  19 //usage:       " [-ti"IF_FEATURE_CPIO_O("o")"]" IF_FEATURE_CPIO_P(" [-p DIR]")
  20 //usage:       " [EXTR_FILE]..."
  21 //usage:#define cpio_full_usage "\n\n"
  22 //usage:       "Extract or list files from a cpio archive"
  23 //usage:        IF_FEATURE_CPIO_O(", or"
  24 //usage:     "\ncreate an archive" IF_FEATURE_CPIO_P(" (-o) or copy files (-p)")
  25 //usage:                " using file list on stdin"
  26 //usage:        )
  27 //usage:     "\n"
  28 //usage:     "\nMain operation mode:"
  29 //usage:     "\n        -t      List"
  30 //usage:     "\n        -i      Extract EXTR_FILEs (or all)"
  31 //usage:        IF_FEATURE_CPIO_O(
  32 //usage:     "\n        -o      Create (requires -H newc)"
  33 //usage:        )
  34 //usage:        IF_FEATURE_CPIO_P(
  35 //usage:     "\n        -p DIR  Copy files to DIR"
  36 //usage:        )
  37 //usage:     "\n        -d      Make leading directories"
  38 //usage:     "\n        -m      Preserve mtime"
  39 //usage:     "\n        -v      Verbose"
  40 //usage:     "\n        -u      Overwrite"
  41 //usage:     "\n        -F FILE Input (-t,-i,-p) or output (-o) file"
  42 //usage:        IF_FEATURE_CPIO_O(
  43 //usage:     "\n        -H newc Archive format"
  44 //usage:        )
  45
  46 /* GNU cpio 2.9 --help (abridged):
  47
  48  Modes:
  49   -t, --list                 List the archive
  50   -i, --extract              Extract files from an archive
  51   -o, --create               Create the archive
  52   -p, --pass-through         Copy-pass mode
  53
  54  Options valid in any mode:
  55       --block-size=SIZE      I/O block size = SIZE * 512 bytes
  56   -B                         I/O block size = 5120 bytes
  57   -c                         Use the old portable (ASCII) archive format
  58   -C, --io-size=NUMBER       I/O block size in bytes
  59   -f, --nonmatching          Only copy files that do not match given pattern
  60   -F, --file=FILE            Use FILE instead of standard input or output
  61   -H, --format=FORMAT        Use given archive FORMAT
  62   -M, --message=STRING       Print STRING when the end of a volume of the
  63                              backup media is reached
  64   -n, --numeric-uid-gid      If -v, show numeric UID and GID
  65       --quiet                Do not print the number of blocks copied
  66       --rsh-command=COMMAND  Use remote COMMAND instead of rsh
  67   -v, --verbose              Verbosely list the files processed
  68   -V, --dot                  Print a "." for each file processed
  69   -W, --warning=FLAG         Control warning display: 'none','truncate','all';
  70                              multiple options accumulate
  71
  72  Options valid only in --extract mode:
  73   -b, --swap                 Swap both halfwords of words and bytes of
  74                              halfwords in the data (equivalent to -sS)
  75   -r, --rename               Interactively rename files
  76   -s, --swap-bytes           Swap the bytes of each halfword in the files
  77   -S, --swap-halfwords       Swap the halfwords of each word (4 bytes)
  78       --to-stdout            Extract files to standard output
  79   -E, --pattern-file=FILE    Read additional patterns specifying filenames to
  80                              extract or list from FILE
  81       --only-verify-crc      Verify CRC's, don't actually extract the files
  82
  83  Options valid only in --create mode:
  84   -A, --append               Append to an existing archive
  85   -O FILE                    File to use instead of standard output
  86
  87  Options valid only in --pass-through mode:
  88   -l, --link                 Link files instead of copying them, when possible
  89
  90  Options valid in --extract and --create modes:
  91       --absolute-filenames   Do not strip file system prefix components from
  92                              the file names
  93       --no-absolute-filenames Create all files relative to the current dir
  94
  95  Options valid in --create and --pass-through modes:
  96   -0, --null                 A list of filenames is terminated by a NUL
  97   -a, --reset-access-time    Reset the access times of files after reading them
  98   -I FILE                    File to use instead of standard input
  99   -L, --dereference          Dereference symbolic links (copy the files
 100                              that they point to instead of copying the links)
 101   -R, --owner=[USER][:.][GROUP] Set owner of created files
 102
 103  Options valid in --extract and --pass-through modes:
 104   -d, --make-directories     Create leading directories where needed
 105   -m, --preserve-modification-time  Retain mtime when creating files
 106       --no-preserve-owner    Do not change the ownership of the files
 107       --sparse               Write files with blocks of zeros as sparse files
 108   -u, --unconditional        Replace all files unconditionally
 109  */
 110
 111 enum {
 112         OPT_EXTRACT            = (1 << 0),
 113         OPT_TEST               = (1 << 1),
 114         OPT_NUL_TERMINATED     = (1 << 2),
 115         OPT_UNCONDITIONAL      = (1 << 3),
 116         OPT_VERBOSE            = (1 << 4),
 117         OPT_CREATE_LEADING_DIR = (1 << 5),
 118         OPT_PRESERVE_MTIME     = (1 << 6),
 119         OPT_DEREF              = (1 << 7),
 120         OPT_FILE               = (1 << 8),
 121         OPTBIT_FILE = 8,
 122         IF_FEATURE_CPIO_O(OPTBIT_CREATE     ,)
 123         IF_FEATURE_CPIO_O(OPTBIT_FORMAT     ,)
 124         IF_FEATURE_CPIO_P(OPTBIT_PASSTHROUGH,)
 125         IF_LONG_OPTS(     OPTBIT_QUIET      ,)
 126         IF_LONG_OPTS(     OPTBIT_2STDOUT    ,)
 127         OPT_CREATE             = IF_FEATURE_CPIO_O((1 << OPTBIT_CREATE     )) + 0,
 128         OPT_FORMAT             = IF_FEATURE_CPIO_O((1 << OPTBIT_FORMAT     )) + 0,
 129         OPT_PASSTHROUGH        = IF_FEATURE_CPIO_P((1 << OPTBIT_PASSTHROUGH)) + 0,
 130         OPT_QUIET              = IF_LONG_OPTS(     (1 << OPTBIT_QUIET      )) + 0,
 131         OPT_2STDOUT            = IF_LONG_OPTS(     (1 << OPTBIT_2STDOUT    )) + 0,
 132 };
 133
 134 #define OPTION_STR "it0uvdmLF:"
 135
 136 #if ENABLE_FEATURE_CPIO_O
 137 static off_t cpio_pad4(off_t size)
 138 {
 139         int i;
 140
 141         i = (- size) & 3;
 142         size += i;
 143         while (--i >= 0)
 144                 bb_putchar('\0');
 145         return size;
 146 }
 147
 148 /* Return value will become exit code.
 149  * It's ok to exit instead of return. */
 150 static NOINLINE int cpio_o(void)
 151 {
 152         static const char trailer[] ALIGN1 = "TRAILER!!!";
 153         struct name_s {
 154                 struct name_s *next;
 155                 char name[1];
 156         };
 157         struct inodes_s {
 158                 struct inodes_s *next;
 159                 struct name_s *names;
 160                 struct stat st;
 161         };
 162
 163         struct inodes_s *links = NULL;
 164         off_t bytes = 0; /* output bytes count */
 165
 166         while (1) {
 167                 const char *name;
 168                 char *line;
 169                 struct stat st;
 170
 171                 line = (option_mask32 & OPT_NUL_TERMINATED)
 172                                 ? bb_get_chunk_from_file(stdin, NULL)
 173                                 : xmalloc_fgetline(stdin);
 174
 175                 if (line) {
 176                         /* Strip leading "./[./]..." from the filename */
 177                         name = line;
 178                         while (name[0] == '.' && name[1] == '/') {
 179                                 while (*++name == '/')
 180                                         continue;
 181                         }
 182                         if (!*name) { /* line is empty */
 183                                 free(line);
 184                                 continue;
 185                         }
 186                         if ((option_mask32 & OPT_DEREF)
 187                                         ? stat(name, &st)
 188                                         : lstat(name, &st)
 189                         ) {
 190  abort_cpio_o:
 191                                 bb_simple_perror_msg_and_die(name);
 192                         }
 193
 194                         if (!(S_ISLNK(st.st_mode) || S_ISREG(st.st_mode)))
 195                                 st.st_size = 0; /* paranoia */
 196
 197                         /* Store hardlinks for later processing, dont output them */
 198                         if (!S_ISDIR(st.st_mode) && st.st_nlink > 1) {
 199                                 struct name_s *n;
 200                                 struct inodes_s *l;
 201
 202                                 /* Do we have this hardlink remembered? */
 203                                 l = links;
 204                                 while (1) {
 205                                         if (l == NULL) {
 206                                                 /* Not found: add new item to "links" list */
 207                                                 l = xzalloc(sizeof(*l));
 208                                                 l->st = st;
 209                                                 l->next = links;
 210                                                 links = l;
 211                                                 break;
 212                                         }
 213                                         if (l->st.st_ino == st.st_ino) {
 214                                                 /* found */
 215                                                 break;
 216                                         }
 217                                         l = l->next;
 218                                 }
 219                                 /* Add new name to "l->names" list */
 220                                 n = xmalloc(sizeof(*n) + strlen(name));
 221                                 strcpy(n->name, name);
 222                                 n->next = l->names;
 223                                 l->names = n;
 224
 225                                 free(line);
 226                                 continue;
 227                         }
 228
 229                 } else { /* line == NULL: EOF */
 230  next_link:
 231                         if (links) {
 232                                 /* Output hardlink's data */
 233                                 st = links->st;
 234                                 name = links->names->name;
 235                                 links->names = links->names->next;
 236                                 /* GNU cpio is reported to emit file data
 237                                  * only for the last instance. Mimic that. */
 238                                 if (links->names == NULL)
 239                                         links = links->next;
 240                                 else
 241                                         st.st_size = 0;
 242                                 /* NB: we leak links->names and/or links,
 243                                  * this is intended (we exit soon anyway) */
 244                         } else {
 245                                 /* If no (more) hardlinks to output,
 246                                  * output "trailer" entry */
 247                                 name = trailer;
 248                                 /* st.st_size == 0 is a must, but for uniformity
 249                                  * in the output, we zero out everything */
 250                                 memset(&st, 0, sizeof(st));
 251                                 /* st.st_nlink = 1; - GNU cpio does this */
 252                         }
 253                 }
 254
 255                 bytes += printf("070701"
 256                                 "%08X%08X%08X%08X%08X%08X%08X"
 257                                 "%08X%08X%08X%08X" /* GNU cpio uses uppercase hex */
 258                                 /* strlen+1: */ "%08X"
 259                                 /* chksum: */   "00000000" /* (only for "070702" files) */
 260                                 /* name,NUL: */ "%s%c",
 261                                 (unsigned)(uint32_t) st.st_ino,
 262                                 (unsigned)(uint32_t) st.st_mode,
 263                                 (unsigned)(uint32_t) st.st_uid,
 264                                 (unsigned)(uint32_t) st.st_gid,
 265                                 (unsigned)(uint32_t) st.st_nlink,
 266                                 (unsigned)(uint32_t) st.st_mtime,
 267                                 (unsigned)(uint32_t) st.st_size,
 268                                 (unsigned)(uint32_t) major(st.st_dev),
 269                                 (unsigned)(uint32_t) minor(st.st_dev),
 270                                 (unsigned)(uint32_t) major(st.st_rdev),
 271                                 (unsigned)(uint32_t) minor(st.st_rdev),
 272                                 (unsigned)(strlen(name) + 1),
 273                                 name, '\0');
 274                 bytes = cpio_pad4(bytes);
 275
 276                 if (st.st_size) {
 277                         if (S_ISLNK(st.st_mode)) {
 278                                 char *lpath = xmalloc_readlink_or_warn(name);
 279                                 if (!lpath)
 280                                         goto abort_cpio_o;
 281                                 bytes += printf("%s", lpath);
 282                                 free(lpath);
 283                         } else { /* S_ISREG */
 284                                 int fd = xopen(name, O_RDONLY);
 285                                 fflush_all();
 286                                 /* We must abort if file got shorter too! */
 287                                 bb_copyfd_exact_size(fd, STDOUT_FILENO, st.st_size);
 288                                 bytes += st.st_size;
 289                                 close(fd);
 290                         }
 291                         bytes = cpio_pad4(bytes);
 292                 }
 293
 294                 if (!line) {
 295                         if (name != trailer)
 296                                 goto next_link;
 297                         /* TODO: GNU cpio pads trailer to 512 bytes, do we want that? */
 298                         return EXIT_SUCCESS;
 299                 }
 300
 301                 free(line);
 302         } /* end of "while (1)" */
 303 }
 304 #endif
 305
 306 int cpio_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 307 int cpio_main(int argc UNUSED_PARAM, char **argv)
 308 {
 309         archive_handle_t *archive_handle;
 310         char *cpio_filename;
 311         IF_FEATURE_CPIO_O(const char *cpio_fmt = "";)
 312         unsigned opt;
 313
 314 #if ENABLE_LONG_OPTS
 315         applet_long_options =
 316                 "extract\0"      No_argument       "i"
 317                 "list\0"         No_argument       "t"
 318 #if ENABLE_FEATURE_CPIO_O
 319                 "create\0"       No_argument       "o"
 320                 "format\0"       Required_argument "H"
 321 #if ENABLE_FEATURE_CPIO_P
 322                 "pass-through\0" No_argument       "p"
 323 #endif
 324 #endif
 325                 "verbose\0"      No_argument       "v"
 326                 "quiet\0"        No_argument       "\xff"
 327                 "to-stdout\0"    No_argument       "\xfe"
 328                 ;
 329 #endif
 330
 331         archive_handle = init_handle();
 332         /* archive_handle->src_fd = STDIN_FILENO; - done by init_handle */
 333         archive_handle->ah_flags = ARCHIVE_EXTRACT_NEWER;
 334
 335         /* As of now we do not enforce this: */
 336         /* -i,-t,-o,-p are mutually exclusive */
 337         /* -u,-d,-m make sense only with -i or -p */
 338         /* -L makes sense only with -o or -p */
 339
 340 #if !ENABLE_FEATURE_CPIO_O
 341         opt = getopt32(argv, OPTION_STR, &cpio_filename);
 342         argv += optind;
 343         if (opt & OPT_FILE) { /* -F */
 344                 xmove_fd(xopen(cpio_filename, O_RDONLY), STDIN_FILENO);
 345         }
 346 #else
 347         opt = getopt32(argv, OPTION_STR "oH:" IF_FEATURE_CPIO_P("p"), &cpio_filename, &cpio_fmt);
 348         argv += optind;
 349         if ((opt & (OPT_FILE|OPT_CREATE)) == OPT_FILE) { /* -F without -o */
 350                 xmove_fd(xopen(cpio_filename, O_RDONLY), STDIN_FILENO);
 351         }
 352         if (opt & OPT_PASSTHROUGH) {
 353                 pid_t pid;
 354                 struct fd_pair pp;
 355
 356                 if (argv[0] == NULL)
 357                         bb_show_usage();
 358                 if (opt & OPT_CREATE_LEADING_DIR)
 359                         mkdir(argv[0], 0777);
 360                 /* Crude existence check:
 361                  * close(xopen(argv[0], O_RDONLY | O_DIRECTORY));
 362                  * We can also xopen, fstat, IS_DIR, later fchdir.
 363                  * This would check for existence earlier and cleaner.
 364                  * As it stands now, if we fail xchdir later,
 365                  * child dies on EPIPE, unless it caught
 366                  * a diffrerent problem earlier.
 367                  * This is good enough for now.
 368                  */
 369 #if !BB_MMU
 370                 pp.rd = 3;
 371                 pp.wr = 4;
 372                 if (!re_execed) {
 373                         close(3);
 374                         close(4);
 375                         xpiped_pair(pp);
 376                 }
 377 #else
 378                 xpiped_pair(pp);
 379 #endif
 380                 pid = fork_or_rexec(argv - optind);
 381                 if (pid == 0) { /* child */
 382                         close(pp.rd);
 383                         xmove_fd(pp.wr, STDOUT_FILENO);
 384                         goto dump;
 385                 }
 386                 /* parent */
 387                 xchdir(*argv++);
 388                 close(pp.wr);
 389                 xmove_fd(pp.rd, STDIN_FILENO);
 390                 //opt &= ~OPT_PASSTHROUGH;
 391                 opt |= OPT_EXTRACT;
 392                 goto skip;
 393         }
 394         /* -o */
 395         if (opt & OPT_CREATE) {
 396                 if (cpio_fmt[0] != 'n') /* we _require_ "-H newc" */
 397                         bb_show_usage();
 398                 if (opt & OPT_FILE) {
 399                         xmove_fd(xopen(cpio_filename, O_WRONLY | O_CREAT | O_TRUNC), STDOUT_FILENO);
 400                 }
 401  dump:
 402                 return cpio_o();
 403         }
 404  skip:
 405 #endif
 406
 407         /* One of either extract or test options must be given */
 408         if ((opt & (OPT_TEST | OPT_EXTRACT)) == 0) {
 409                 bb_show_usage();
 410         }
 411
 412         if (opt & OPT_TEST) {
 413                 /* if both extract and test options are given, ignore extract option */
 414                 opt &= ~OPT_EXTRACT;
 415                 archive_handle->action_header = header_list;
 416         }
 417         if (opt & OPT_EXTRACT) {
 418                 archive_handle->action_data = data_extract_all;
 419                 if (opt & OPT_2STDOUT)
 420                         archive_handle->action_data = data_extract_to_stdout;
 421         }
 422         if (opt & OPT_UNCONDITIONAL) {
 423                 archive_handle->ah_flags |= ARCHIVE_UNLINK_OLD;
 424                 archive_handle->ah_flags &= ~ARCHIVE_EXTRACT_NEWER;
 425         }
 426         if (opt & OPT_VERBOSE) {
 427                 if (archive_handle->action_header == header_list) {
 428                         archive_handle->action_header = header_verbose_list;
 429                 } else {
 430                         archive_handle->action_header = header_list;
 431                 }
 432         }
 433         if (opt & OPT_CREATE_LEADING_DIR) {
 434                 archive_handle->ah_flags |= ARCHIVE_CREATE_LEADING_DIRS;
 435         }
 436         if (opt & OPT_PRESERVE_MTIME) {
 437                 archive_handle->ah_flags |= ARCHIVE_RESTORE_DATE;
 438         }
 439
 440         while (*argv) {
 441                 archive_handle->filter = filter_accept_list;
 442                 llist_add_to(&archive_handle->accept, *argv);
 443                 argv++;
 444         }
 445
 446         /* see get_header_cpio */
 447         archive_handle->cpio__blocks = (off_t)-1;
 448         while (get_header_cpio(archive_handle) == EXIT_SUCCESS)
 449                 continue;
 450
 451         if (archive_handle->cpio__blocks != (off_t)-1
 452          && !(opt & OPT_QUIET)
 453         ) {
 454                 fprintf(stderr, "%"OFF_FMT"u blocks\n", archive_handle->cpio__blocks);
 455         }
 456
 457         return EXIT_SUCCESS;
 458 }