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 #include "libbb.h"
  14 #include "bb_archive.h"
  15
  16 //config:config CPIO
  17 //config:       bool "cpio"
  18 //config:       default y
  19 //config:       help
  20 //config:         cpio is an archival utility program used to create, modify, and
  21 //config:         extract contents from archives.
  22 //config:         cpio has 110 bytes of overheads for every stored file.
  23 //config:
  24 //config:         This implementation of cpio can extract cpio archives created in the
  25 //config:         "newc" or "crc" format, it cannot create or modify them.
  26 //config:
  27 //config:         Unless you have a specific application which requires cpio, you
  28 //config:         should probably say N here.
  29 //config:
  30 //config:config FEATURE_CPIO_O
  31 //config:       bool "Support for archive creation"
  32 //config:       default y
  33 //config:       depends on CPIO
  34 //config:       help
  35 //config:         This implementation of cpio can create cpio archives in the "newc"
  36 //config:         format only.
  37 //config:
  38 //config:config FEATURE_CPIO_P
  39 //config:       bool "Support for passthrough mode"
  40 //config:       default y
  41 //config:       depends on FEATURE_CPIO_O
  42 //config:       help
  43 //config:         Passthrough mode. Rarely used.
  44
  45 //applet:IF_CPIO(APPLET(cpio, BB_DIR_BIN, BB_SUID_DROP))
  46 //kbuild:lib-$(CONFIG_CPIO) += cpio.o
  47
  48 //usage:#define cpio_trivial_usage
  49 //usage:       "[-dmvu] [-F FILE]" IF_FEATURE_CPIO_O(" [-H newc]")
  50 //usage:       " [-ti"IF_FEATURE_CPIO_O("o")"]" IF_FEATURE_CPIO_P(" [-p DIR]")
  51 //usage:       " [EXTR_FILE]..."
  52 //usage:#define cpio_full_usage "\n\n"
  53 //usage:       "Extract or list files from a cpio archive"
  54 //usage:        IF_FEATURE_CPIO_O(", or"
  55 //usage:     "\ncreate an archive" IF_FEATURE_CPIO_P(" (-o) or copy files (-p)")
  56 //usage:                " using file list on stdin"
  57 //usage:        )
  58 //usage:     "\n"
  59 //usage:     "\nMain operation mode:"
  60 //usage:     "\n        -t      List"
  61 //usage:     "\n        -i      Extract EXTR_FILEs (or all)"
  62 //usage:        IF_FEATURE_CPIO_O(
  63 //usage:     "\n        -o      Create (requires -H newc)"
  64 //usage:        )
  65 //usage:        IF_FEATURE_CPIO_P(
  66 //usage:     "\n        -p DIR  Copy files to DIR"
  67 //usage:        )
  68 //usage:     "\n        -d      Make leading directories"
  69 //usage:     "\n        -m      Preserve mtime"
  70 //usage:     "\n        -v      Verbose"
  71 //usage:     "\n        -u      Overwrite"
  72 //usage:     "\n        -F FILE Input (-t,-i,-p) or output (-o) file"
  73 //usage:        IF_FEATURE_CPIO_O(
  74 //usage:     "\n        -H newc Archive format"
  75 //usage:        )
  76
  77 /* GNU cpio 2.9 --help (abridged):
  78
  79  Modes:
  80   -t, --list                 List the archive
  81   -i, --extract              Extract files from an archive
  82   -o, --create               Create the archive
  83   -p, --pass-through         Copy-pass mode
  84
  85  Options valid in any mode:
  86       --block-size=SIZE      I/O block size = SIZE * 512 bytes
  87   -B                         I/O block size = 5120 bytes
  88   -c                         Use the old portable (ASCII) archive format
  89   -C, --io-size=NUMBER       I/O block size in bytes
  90   -f, --nonmatching          Only copy files that do not match given pattern
  91   -F, --file=FILE            Use FILE instead of standard input or output
  92   -H, --format=FORMAT        Use given archive FORMAT
  93   -M, --message=STRING       Print STRING when the end of a volume of the
  94                              backup media is reached
  95   -n, --numeric-uid-gid      If -v, show numeric UID and GID
  96       --quiet                Do not print the number of blocks copied
  97       --rsh-command=COMMAND  Use remote COMMAND instead of rsh
  98   -v, --verbose              Verbosely list the files processed
  99   -V, --dot                  Print a "." for each file processed
 100   -W, --warning=FLAG         Control warning display: 'none','truncate','all';
 101                              multiple options accumulate
 102
 103  Options valid only in --extract mode:
 104   -b, --swap                 Swap both halfwords of words and bytes of
 105                              halfwords in the data (equivalent to -sS)
 106   -r, --rename               Interactively rename files
 107   -s, --swap-bytes           Swap the bytes of each halfword in the files
 108   -S, --swap-halfwords       Swap the halfwords of each word (4 bytes)
 109       --to-stdout            Extract files to standard output
 110   -E, --pattern-file=FILE    Read additional patterns specifying filenames to
 111                              extract or list from FILE
 112       --only-verify-crc      Verify CRC's, don't actually extract the files
 113
 114  Options valid only in --create mode:
 115   -A, --append               Append to an existing archive
 116   -O FILE                    File to use instead of standard output
 117
 118  Options valid only in --pass-through mode:
 119   -l, --link                 Link files instead of copying them, when possible
 120
 121  Options valid in --extract and --create modes:
 122       --absolute-filenames   Do not strip file system prefix components from
 123                              the file names
 124       --no-absolute-filenames Create all files relative to the current dir
 125
 126  Options valid in --create and --pass-through modes:
 127   -0, --null                 A list of filenames is terminated by a NUL
 128   -a, --reset-access-time    Reset the access times of files after reading them
 129   -I FILE                    File to use instead of standard input
 130   -L, --dereference          Dereference symbolic links (copy the files
 131                              that they point to instead of copying the links)
 132   -R, --owner=[USER][:.][GROUP] Set owner of created files
 133
 134  Options valid in --extract and --pass-through modes:
 135   -d, --make-directories     Create leading directories where needed
 136   -m, --preserve-modification-time  Retain mtime when creating files
 137       --no-preserve-owner    Do not change the ownership of the files
 138       --sparse               Write files with blocks of zeros as sparse files
 139   -u, --unconditional        Replace all files unconditionally
 140  */
 141
 142 enum {
 143         OPT_EXTRACT            = (1 << 0),
 144         OPT_TEST               = (1 << 1),
 145         OPT_NUL_TERMINATED     = (1 << 2),
 146         OPT_UNCONDITIONAL      = (1 << 3),
 147         OPT_VERBOSE            = (1 << 4),
 148         OPT_CREATE_LEADING_DIR = (1 << 5),
 149         OPT_PRESERVE_MTIME     = (1 << 6),
 150         OPT_DEREF              = (1 << 7),
 151         OPT_FILE               = (1 << 8),
 152         OPTBIT_FILE = 8,
 153         IF_FEATURE_CPIO_O(OPTBIT_CREATE     ,)
 154         IF_FEATURE_CPIO_O(OPTBIT_FORMAT     ,)
 155         IF_FEATURE_CPIO_P(OPTBIT_PASSTHROUGH,)
 156         IF_LONG_OPTS(     OPTBIT_QUIET      ,)
 157         IF_LONG_OPTS(     OPTBIT_2STDOUT    ,)
 158         OPT_CREATE             = IF_FEATURE_CPIO_O((1 << OPTBIT_CREATE     )) + 0,
 159         OPT_FORMAT             = IF_FEATURE_CPIO_O((1 << OPTBIT_FORMAT     )) + 0,
 160         OPT_PASSTHROUGH        = IF_FEATURE_CPIO_P((1 << OPTBIT_PASSTHROUGH)) + 0,
 161         OPT_QUIET              = IF_LONG_OPTS(     (1 << OPTBIT_QUIET      )) + 0,
 162         OPT_2STDOUT            = IF_LONG_OPTS(     (1 << OPTBIT_2STDOUT    )) + 0,
 163 };
 164
 165 #define OPTION_STR "it0uvdmLF:"
 166
 167 #if ENABLE_FEATURE_CPIO_O
 168 static off_t cpio_pad4(off_t size)
 169 {
 170         int i;
 171
 172         i = (- size) & 3;
 173         size += i;
 174         while (--i >= 0)
 175                 bb_putchar('\0');
 176         return size;
 177 }
 178
 179 /* Return value will become exit code.
 180  * It's ok to exit instead of return. */
 181 static NOINLINE int cpio_o(void)
 182 {
 183         static const char trailer[] ALIGN1 = "TRAILER!!!";
 184         struct name_s {
 185                 struct name_s *next;
 186                 char name[1];
 187         };
 188         struct inodes_s {
 189                 struct inodes_s *next;
 190                 struct name_s *names;
 191                 struct stat st;
 192         };
 193
 194         struct inodes_s *links = NULL;
 195         off_t bytes = 0; /* output bytes count */
 196
 197         while (1) {
 198                 const char *name;
 199                 char *line;
 200                 struct stat st;
 201
 202                 line = (option_mask32 & OPT_NUL_TERMINATED)
 203                                 ? bb_get_chunk_from_file(stdin, NULL)
 204                                 : xmalloc_fgetline(stdin);
 205
 206                 if (line) {
 207                         /* Strip leading "./[./]..." from the filename */
 208                         name = line;
 209                         while (name[0] == '.' && name[1] == '/') {
 210                                 while (*++name == '/')
 211                                         continue;
 212                         }
 213                         if (!*name) { /* line is empty */
 214                                 free(line);
 215                                 continue;
 216                         }
 217                         if ((option_mask32 & OPT_DEREF)
 218                                         ? stat(name, &st)
 219                                         : lstat(name, &st)
 220                         ) {
 221  abort_cpio_o:
 222                                 bb_simple_perror_msg_and_die(name);
 223                         }
 224
 225                         if (!(S_ISLNK(st.st_mode) || S_ISREG(st.st_mode)))
 226                                 st.st_size = 0; /* paranoia */
 227
 228                         /* Store hardlinks for later processing, dont output them */
 229                         if (!S_ISDIR(st.st_mode) && st.st_nlink > 1) {
 230                                 struct name_s *n;
 231                                 struct inodes_s *l;
 232
 233                                 /* Do we have this hardlink remembered? */
 234                                 l = links;
 235                                 while (1) {
 236                                         if (l == NULL) {
 237                                                 /* Not found: add new item to "links" list */
 238                                                 l = xzalloc(sizeof(*l));
 239                                                 l->st = st;
 240                                                 l->next = links;
 241                                                 links = l;
 242                                                 break;
 243                                         }
 244                                         if (l->st.st_ino == st.st_ino) {
 245                                                 /* found */
 246                                                 break;
 247                                         }
 248                                         l = l->next;
 249                                 }
 250                                 /* Add new name to "l->names" list */
 251                                 n = xmalloc(sizeof(*n) + strlen(name));
 252                                 strcpy(n->name, name);
 253                                 n->next = l->names;
 254                                 l->names = n;
 255
 256                                 free(line);
 257                                 continue;
 258                         }
 259
 260                 } else { /* line == NULL: EOF */
 261  next_link:
 262                         if (links) {
 263                                 /* Output hardlink's data */
 264                                 st = links->st;
 265                                 name = links->names->name;
 266                                 links->names = links->names->next;
 267                                 /* GNU cpio is reported to emit file data
 268                                  * only for the last instance. Mimic that. */
 269                                 if (links->names == NULL)
 270                                         links = links->next;
 271                                 else
 272                                         st.st_size = 0;
 273                                 /* NB: we leak links->names and/or links,
 274                                  * this is intended (we exit soon anyway) */
 275                         } else {
 276                                 /* If no (more) hardlinks to output,
 277                                  * output "trailer" entry */
 278                                 name = trailer;
 279                                 /* st.st_size == 0 is a must, but for uniformity
 280                                  * in the output, we zero out everything */
 281                                 memset(&st, 0, sizeof(st));
 282                                 /* st.st_nlink = 1; - GNU cpio does this */
 283                         }
 284                 }
 285
 286                 bytes += printf("070701"
 287                                 "%08X%08X%08X%08X%08X%08X%08X"
 288                                 "%08X%08X%08X%08X" /* GNU cpio uses uppercase hex */
 289                                 /* strlen+1: */ "%08X"
 290                                 /* chksum: */   "00000000" /* (only for "070702" files) */
 291                                 /* name,NUL: */ "%s%c",
 292                                 (unsigned)(uint32_t) st.st_ino,
 293                                 (unsigned)(uint32_t) st.st_mode,
 294                                 (unsigned)(uint32_t) st.st_uid,
 295                                 (unsigned)(uint32_t) st.st_gid,
 296                                 (unsigned)(uint32_t) st.st_nlink,
 297                                 (unsigned)(uint32_t) st.st_mtime,
 298                                 (unsigned)(uint32_t) st.st_size,
 299                                 (unsigned)(uint32_t) major(st.st_dev),
 300                                 (unsigned)(uint32_t) minor(st.st_dev),
 301                                 (unsigned)(uint32_t) major(st.st_rdev),
 302                                 (unsigned)(uint32_t) minor(st.st_rdev),
 303                                 (unsigned)(strlen(name) + 1),
 304                                 name, '\0');
 305                 bytes = cpio_pad4(bytes);
 306
 307                 if (st.st_size) {
 308                         if (S_ISLNK(st.st_mode)) {
 309                                 char *lpath = xmalloc_readlink_or_warn(name);
 310                                 if (!lpath)
 311                                         goto abort_cpio_o;
 312                                 bytes += printf("%s", lpath);
 313                                 free(lpath);
 314                         } else { /* S_ISREG */
 315                                 int fd = xopen(name, O_RDONLY);
 316                                 fflush_all();
 317                                 /* We must abort if file got shorter too! */
 318                                 bb_copyfd_exact_size(fd, STDOUT_FILENO, st.st_size);
 319                                 bytes += st.st_size;
 320                                 close(fd);
 321                         }
 322                         bytes = cpio_pad4(bytes);
 323                 }
 324
 325                 if (!line) {
 326                         if (name != trailer)
 327                                 goto next_link;
 328                         /* TODO: GNU cpio pads trailer to 512 bytes, do we want that? */
 329                         return EXIT_SUCCESS;
 330                 }
 331
 332                 free(line);
 333         } /* end of "while (1)" */
 334 }
 335 #endif
 336
 337 int cpio_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 338 int cpio_main(int argc UNUSED_PARAM, char **argv)
 339 {
 340         archive_handle_t *archive_handle;
 341         char *cpio_filename;
 342         IF_FEATURE_CPIO_O(const char *cpio_fmt = "";)
 343         unsigned opt;
 344
 345 #if ENABLE_LONG_OPTS
 346         applet_long_options =
 347                 "extract\0"      No_argument       "i"
 348                 "list\0"         No_argument       "t"
 349 #if ENABLE_FEATURE_CPIO_O
 350                 "create\0"       No_argument       "o"
 351                 "format\0"       Required_argument "H"
 352 #if ENABLE_FEATURE_CPIO_P
 353                 "pass-through\0" No_argument       "p"
 354 #endif
 355 #endif
 356                 "verbose\0"      No_argument       "v"
 357                 "quiet\0"        No_argument       "\xff"
 358                 "to-stdout\0"    No_argument       "\xfe"
 359                 ;
 360 #endif
 361
 362         archive_handle = init_handle();
 363         /* archive_handle->src_fd = STDIN_FILENO; - done by init_handle */
 364         archive_handle->ah_flags = ARCHIVE_EXTRACT_NEWER;
 365
 366         /* As of now we do not enforce this: */
 367         /* -i,-t,-o,-p are mutually exclusive */
 368         /* -u,-d,-m make sense only with -i or -p */
 369         /* -L makes sense only with -o or -p */
 370
 371 #if !ENABLE_FEATURE_CPIO_O
 372         opt = getopt32(argv, OPTION_STR, &cpio_filename);
 373         argv += optind;
 374         if (opt & OPT_FILE) { /* -F */
 375                 xmove_fd(xopen(cpio_filename, O_RDONLY), STDIN_FILENO);
 376         }
 377 #else
 378         opt = getopt32(argv, OPTION_STR "oH:" IF_FEATURE_CPIO_P("p"), &cpio_filename, &cpio_fmt);
 379         argv += optind;
 380         if ((opt & (OPT_FILE|OPT_CREATE)) == OPT_FILE) { /* -F without -o */
 381                 xmove_fd(xopen(cpio_filename, O_RDONLY), STDIN_FILENO);
 382         }
 383         if (opt & OPT_PASSTHROUGH) {
 384                 pid_t pid;
 385                 struct fd_pair pp;
 386
 387                 if (argv[0] == NULL)
 388                         bb_show_usage();
 389                 if (opt & OPT_CREATE_LEADING_DIR)
 390                         mkdir(argv[0], 0777);
 391                 /* Crude existence check:
 392                  * close(xopen(argv[0], O_RDONLY | O_DIRECTORY));
 393                  * We can also xopen, fstat, IS_DIR, later fchdir.
 394                  * This would check for existence earlier and cleaner.
 395                  * As it stands now, if we fail xchdir later,
 396                  * child dies on EPIPE, unless it caught
 397                  * a diffrerent problem earlier.
 398                  * This is good enough for now.
 399                  */
 400 #if !BB_MMU
 401                 pp.rd = 3;
 402                 pp.wr = 4;
 403                 if (!re_execed) {
 404                         close(3);
 405                         close(4);
 406                         xpiped_pair(pp);
 407                 }
 408 #else
 409                 xpiped_pair(pp);
 410 #endif
 411                 pid = fork_or_rexec(argv - optind);
 412                 if (pid == 0) { /* child */
 413                         close(pp.rd);
 414                         xmove_fd(pp.wr, STDOUT_FILENO);
 415                         goto dump;
 416                 }
 417                 /* parent */
 418                 USE_FOR_NOMMU(argv[-optind][0] &= 0x7f); /* undo fork_or_rexec() damage */
 419                 xchdir(*argv++);
 420                 close(pp.wr);
 421                 xmove_fd(pp.rd, STDIN_FILENO);
 422                 //opt &= ~OPT_PASSTHROUGH;
 423                 opt |= OPT_EXTRACT;
 424                 goto skip;
 425         }
 426         /* -o */
 427         if (opt & OPT_CREATE) {
 428                 if (cpio_fmt[0] != 'n') /* we _require_ "-H newc" */
 429                         bb_show_usage();
 430                 if (opt & OPT_FILE) {
 431                         xmove_fd(xopen(cpio_filename, O_WRONLY | O_CREAT | O_TRUNC), STDOUT_FILENO);
 432                 }
 433  dump:
 434                 return cpio_o();
 435         }
 436  skip:
 437 #endif
 438
 439         /* One of either extract or test options must be given */
 440         if ((opt & (OPT_TEST | OPT_EXTRACT)) == 0) {
 441                 bb_show_usage();
 442         }
 443
 444         if (opt & OPT_TEST) {
 445                 /* if both extract and test options are given, ignore extract option */
 446                 opt &= ~OPT_EXTRACT;
 447                 archive_handle->action_header = header_list;
 448         }
 449         if (opt & OPT_EXTRACT) {
 450                 archive_handle->action_data = data_extract_all;
 451                 if (opt & OPT_2STDOUT)
 452                         archive_handle->action_data = data_extract_to_stdout;
 453         }
 454         if (opt & OPT_UNCONDITIONAL) {
 455                 archive_handle->ah_flags |= ARCHIVE_UNLINK_OLD;
 456                 archive_handle->ah_flags &= ~ARCHIVE_EXTRACT_NEWER;
 457         }
 458         if (opt & OPT_VERBOSE) {
 459                 if (archive_handle->action_header == header_list) {
 460                         archive_handle->action_header = header_verbose_list;
 461                 } else {
 462                         archive_handle->action_header = header_list;
 463                 }
 464         }
 465         if (opt & OPT_CREATE_LEADING_DIR) {
 466                 archive_handle->ah_flags |= ARCHIVE_CREATE_LEADING_DIRS;
 467         }
 468         if (opt & OPT_PRESERVE_MTIME) {
 469                 archive_handle->ah_flags |= ARCHIVE_RESTORE_DATE;
 470         }
 471
 472         while (*argv) {
 473                 archive_handle->filter = filter_accept_list;
 474                 llist_add_to(&archive_handle->accept, *argv);
 475                 argv++;
 476         }
 477
 478         /* see get_header_cpio */
 479         archive_handle->cpio__blocks = (off_t)-1;
 480         while (get_header_cpio(archive_handle) == EXIT_SUCCESS)
 481                 continue;
 482
 483         if (archive_handle->cpio__blocks != (off_t)-1
 484          && !(opt & OPT_QUIET)
 485         ) {
 486                 fprintf(stderr, "%"OFF_FMT"u blocks\n", archive_handle->cpio__blocks);
 487         }
 488
 489         return EXIT_SUCCESS;
 490 }