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